1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
  24  * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
  25  */
  26 
  27 /* Portions Copyright 2007 Jeremy Teo */
  28 /* Portions Copyright 2010 Robert Milkowski */
  29 
  30 #include <sys/types.h>
  31 #include <sys/param.h>
  32 #include <sys/time.h>
  33 #include <sys/systm.h>
  34 #include <sys/sysmacros.h>
  35 #include <sys/resource.h>
  36 #include <sys/vfs.h>
  37 #include <sys/vfs_opreg.h>
  38 #include <sys/vnode.h>
  39 #include <sys/file.h>
  40 #include <sys/stat.h>
  41 #include <sys/kmem.h>
  42 #include <sys/taskq.h>
  43 #include <sys/uio.h>
  44 #include <sys/vmsystm.h>
  45 #include <sys/atomic.h>
  46 #include <sys/vm.h>
  47 #include <vm/seg_vn.h>
  48 #include <vm/pvn.h>
  49 #include <vm/as.h>
  50 #include <vm/kpm.h>
  51 #include <vm/seg_kpm.h>
  52 #include <sys/mman.h>
  53 #include <sys/pathname.h>
  54 #include <sys/cmn_err.h>
  55 #include <sys/errno.h>
  56 #include <sys/unistd.h>
  57 #include <sys/zfs_dir.h>
  58 #include <sys/zfs_acl.h>
  59 #include <sys/zfs_ioctl.h>
  60 #include <sys/fs/zfs.h>
  61 #include <sys/dmu.h>
  62 #include <sys/dmu_objset.h>
  63 #include <sys/spa.h>
  64 #include <sys/txg.h>
  65 #include <sys/dbuf.h>
  66 #include <sys/zap.h>
  67 #include <sys/sa.h>
  68 #include <sys/dirent.h>
  69 #include <sys/policy.h>
  70 #include <sys/sunddi.h>
  71 #include <sys/filio.h>
  72 #include <sys/sid.h>
  73 #include "fs/fs_subr.h"
  74 #include <sys/zfs_ctldir.h>
  75 #include <sys/zfs_fuid.h>
  76 #include <sys/zfs_sa.h>
  77 #include <sys/dnlc.h>
  78 #include <sys/zfs_rlock.h>
  79 #include <sys/extdirent.h>
  80 #include <sys/kidmap.h>
  81 #include <sys/cred.h>
  82 #include <sys/attr.h>
  83 
  84 /*
  85  * Programming rules.
  86  *
  87  * Each vnode op performs some logical unit of work.  To do this, the ZPL must
  88  * properly lock its in-core state, create a DMU transaction, do the work,
  89  * record this work in the intent log (ZIL), commit the DMU transaction,
  90  * and wait for the intent log to commit if it is a synchronous operation.
  91  * Moreover, the vnode ops must work in both normal and log replay context.
  92  * The ordering of events is important to avoid deadlocks and references
  93  * to freed memory.  The example below illustrates the following Big Rules:
  94  *
  95  *  (1) A check must be made in each zfs thread for a mounted file system.
  96  *      This is done avoiding races using ZFS_ENTER(zfsvfs).
  97  *      A ZFS_EXIT(zfsvfs) is needed before all returns.  Any znodes
  98  *      must be checked with ZFS_VERIFY_ZP(zp).  Both of these macros
  99  *      can return EIO from the calling function.
 100  *
 101  *  (2) VN_RELE() should always be the last thing except for zil_commit()
 102  *      (if necessary) and ZFS_EXIT(). This is for 3 reasons:
 103  *      First, if it's the last reference, the vnode/znode
 104  *      can be freed, so the zp may point to freed memory.  Second, the last
 105  *      reference will call zfs_zinactive(), which may induce a lot of work --
 106  *      pushing cached pages (which acquires range locks) and syncing out
 107  *      cached atime changes.  Third, zfs_zinactive() may require a new tx,
 108  *      which could deadlock the system if you were already holding one.
 109  *      If you must call VN_RELE() within a tx then use VN_RELE_ASYNC().
 110  *
 111  *  (3) All range locks must be grabbed before calling dmu_tx_assign(),
 112  *      as they can span dmu_tx_assign() calls.
 113  *
 114  *  (4) If ZPL locks are held, pass TXG_NOWAIT as the second argument to
 115  *      dmu_tx_assign().  This is critical because we don't want to block
 116  *      while holding locks.
 117  *
 118  *      If no ZPL locks are held (aside from ZFS_ENTER()), use TXG_WAIT.  This
 119  *      reduces lock contention and CPU usage when we must wait (note that if
 120  *      throughput is constrained by the storage, nearly every transaction
 121  *      must wait).
 122  *
 123  *      Note, in particular, that if a lock is sometimes acquired before
 124  *      the tx assigns, and sometimes after (e.g. z_lock), then failing
 125  *      to use a non-blocking assign can deadlock the system.  The scenario:
 126  *
 127  *      Thread A has grabbed a lock before calling dmu_tx_assign().
 128  *      Thread B is in an already-assigned tx, and blocks for this lock.
 129  *      Thread A calls dmu_tx_assign(TXG_WAIT) and blocks in txg_wait_open()
 130  *      forever, because the previous txg can't quiesce until B's tx commits.
 131  *
 132  *      If dmu_tx_assign() returns ERESTART and zfsvfs->z_assign is TXG_NOWAIT,
 133  *      then drop all locks, call dmu_tx_wait(), and try again.  On subsequent
 134  *      calls to dmu_tx_assign(), pass TXG_WAITED rather than TXG_NOWAIT,
 135  *      to indicate that this operation has already called dmu_tx_wait().
 136  *      This will ensure that we don't retry forever, waiting a short bit
 137  *      each time.
 138  *
 139  *  (5) If the operation succeeded, generate the intent log entry for it
 140  *      before dropping locks.  This ensures that the ordering of events
 141  *      in the intent log matches the order in which they actually occurred.
 142  *      During ZIL replay the zfs_log_* functions will update the sequence
 143  *      number to indicate the zil transaction has replayed.
 144  *
 145  *  (6) At the end of each vnode op, the DMU tx must always commit,
 146  *      regardless of whether there were any errors.
 147  *
 148  *  (7) After dropping all locks, invoke zil_commit(zilog, foid)
 149  *      to ensure that synchronous semantics are provided when necessary.
 150  *
 151  * In general, this is how things should be ordered in each vnode op:
 152  *
 153  *      ZFS_ENTER(zfsvfs);              // exit if unmounted
 154  * top:
 155  *      zfs_dirent_lock(&dl, ...)   // lock directory entry (may VN_HOLD())
 156  *      rw_enter(...);                  // grab any other locks you need
 157  *      tx = dmu_tx_create(...);        // get DMU tx
 158  *      dmu_tx_hold_*();                // hold each object you might modify
 159  *      error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
 160  *      if (error) {
 161  *              rw_exit(...);           // drop locks
 162  *              zfs_dirent_unlock(dl);  // unlock directory entry
 163  *              VN_RELE(...);           // release held vnodes
 164  *              if (error == ERESTART) {
 165  *                      waited = B_TRUE;
 166  *                      dmu_tx_wait(tx);
 167  *                      dmu_tx_abort(tx);
 168  *                      goto top;
 169  *              }
 170  *              dmu_tx_abort(tx);       // abort DMU tx
 171  *              ZFS_EXIT(zfsvfs);       // finished in zfs
 172  *              return (error);         // really out of space
 173  *      }
 174  *      error = do_real_work();         // do whatever this VOP does
 175  *      if (error == 0)
 176  *              zfs_log_*(...);         // on success, make ZIL entry
 177  *      dmu_tx_commit(tx);              // commit DMU tx -- error or not
 178  *      rw_exit(...);                   // drop locks
 179  *      zfs_dirent_unlock(dl);          // unlock directory entry
 180  *      VN_RELE(...);                   // release held vnodes
 181  *      zil_commit(zilog, foid);        // synchronous when necessary
 182  *      ZFS_EXIT(zfsvfs);               // finished in zfs
 183  *      return (error);                 // done, report error
 184  */
 185 
 186 /* ARGSUSED */
 187 static int
 188 zfs_open(vnode_t **vpp, int flag, cred_t *cr, caller_context_t *ct)
 189 {
 190         znode_t *zp = VTOZ(*vpp);
 191         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
 192 
 193         ZFS_ENTER(zfsvfs);
 194         ZFS_VERIFY_ZP(zp);
 195 
 196         if ((flag & FWRITE) && (zp->z_pflags & ZFS_APPENDONLY) &&
 197             ((flag & FAPPEND) == 0)) {
 198                 ZFS_EXIT(zfsvfs);
 199                 return (SET_ERROR(EPERM));
 200         }
 201 
 202         if (!zfs_has_ctldir(zp) && zp->z_zfsvfs->z_vscan &&
 203             ZTOV(zp)->v_type == VREG &&
 204             !(zp->z_pflags & ZFS_AV_QUARANTINED) && zp->z_size > 0) {
 205                 if (fs_vscan(*vpp, cr, 0) != 0) {
 206                         ZFS_EXIT(zfsvfs);
 207                         return (SET_ERROR(EACCES));
 208                 }
 209         }
 210 
 211         /* Keep a count of the synchronous opens in the znode */
 212         if (flag & (FSYNC | FDSYNC))
 213                 atomic_inc_32(&zp->z_sync_cnt);
 214 
 215         ZFS_EXIT(zfsvfs);
 216         return (0);
 217 }
 218 
 219 /* ARGSUSED */
 220 static int
 221 zfs_close(vnode_t *vp, int flag, int count, offset_t offset, cred_t *cr,
 222     caller_context_t *ct)
 223 {
 224         znode_t *zp = VTOZ(vp);
 225         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
 226 
 227         /*
 228          * Clean up any locks held by this process on the vp.
 229          */
 230         cleanlocks(vp, ddi_get_pid(), 0);
 231         cleanshares(vp, ddi_get_pid());
 232 
 233         ZFS_ENTER(zfsvfs);
 234         ZFS_VERIFY_ZP(zp);
 235 
 236         /* Decrement the synchronous opens in the znode */
 237         if ((flag & (FSYNC | FDSYNC)) && (count == 1))
 238                 atomic_dec_32(&zp->z_sync_cnt);
 239 
 240         if (!zfs_has_ctldir(zp) && zp->z_zfsvfs->z_vscan &&
 241             ZTOV(zp)->v_type == VREG &&
 242             !(zp->z_pflags & ZFS_AV_QUARANTINED) && zp->z_size > 0)
 243                 VERIFY(fs_vscan(vp, cr, 1) == 0);
 244 
 245         ZFS_EXIT(zfsvfs);
 246         return (0);
 247 }
 248 
 249 /*
 250  * Lseek support for finding holes (cmd == _FIO_SEEK_HOLE) and
 251  * data (cmd == _FIO_SEEK_DATA). "off" is an in/out parameter.
 252  */
 253 static int
 254 zfs_holey(vnode_t *vp, int cmd, offset_t *off)
 255 {
 256         znode_t *zp = VTOZ(vp);
 257         uint64_t noff = (uint64_t)*off; /* new offset */
 258         uint64_t file_sz;
 259         int error;
 260         boolean_t hole;
 261 
 262         file_sz = zp->z_size;
 263         if (noff >= file_sz)  {
 264                 return (SET_ERROR(ENXIO));
 265         }
 266 
 267         if (cmd == _FIO_SEEK_HOLE)
 268                 hole = B_TRUE;
 269         else
 270                 hole = B_FALSE;
 271 
 272         error = dmu_offset_next(zp->z_zfsvfs->z_os, zp->z_id, hole, &noff);
 273 
 274         if (error == ESRCH)
 275                 return (SET_ERROR(ENXIO));
 276 
 277         /*
 278          * We could find a hole that begins after the logical end-of-file,
 279          * because dmu_offset_next() only works on whole blocks.  If the
 280          * EOF falls mid-block, then indicate that the "virtual hole"
 281          * at the end of the file begins at the logical EOF, rather than
 282          * at the end of the last block.
 283          */
 284         if (noff > file_sz) {
 285                 ASSERT(hole);
 286                 noff = file_sz;
 287         }
 288 
 289         if (noff < *off)
 290                 return (error);
 291         *off = noff;
 292         return (error);
 293 }
 294 
 295 /* ARGSUSED */
 296 static int
 297 zfs_ioctl(vnode_t *vp, int com, intptr_t data, int flag, cred_t *cred,
 298     int *rvalp, caller_context_t *ct)
 299 {
 300         offset_t off;
 301         offset_t ndata;
 302         dmu_object_info_t doi;
 303         int error;
 304         zfsvfs_t *zfsvfs;
 305         znode_t *zp;
 306 
 307         switch (com) {
 308         case _FIOFFS:
 309         {
 310                 return (zfs_sync(vp->v_vfsp, 0, cred));
 311 
 312                 /*
 313                  * The following two ioctls are used by bfu.  Faking out,
 314                  * necessary to avoid bfu errors.
 315                  */
 316         }
 317         case _FIOGDIO:
 318         case _FIOSDIO:
 319         {
 320                 return (0);
 321         }
 322 
 323         case _FIO_SEEK_DATA:
 324         case _FIO_SEEK_HOLE:
 325         {
 326                 if (ddi_copyin((void *)data, &off, sizeof (off), flag))
 327                         return (SET_ERROR(EFAULT));
 328 
 329                 zp = VTOZ(vp);
 330                 zfsvfs = zp->z_zfsvfs;
 331                 ZFS_ENTER(zfsvfs);
 332                 ZFS_VERIFY_ZP(zp);
 333 
 334                 /* offset parameter is in/out */
 335                 error = zfs_holey(vp, com, &off);
 336                 ZFS_EXIT(zfsvfs);
 337                 if (error)
 338                         return (error);
 339                 if (ddi_copyout(&off, (void *)data, sizeof (off), flag))
 340                         return (SET_ERROR(EFAULT));
 341                 return (0);
 342         }
 343         case _FIO_COUNT_FILLED:
 344         {
 345                 /*
 346                  * _FIO_COUNT_FILLED adds a new ioctl command which
 347                  * exposes the number of filled blocks in a
 348                  * ZFS object.
 349                  */
 350                 zp = VTOZ(vp);
 351                 zfsvfs = zp->z_zfsvfs;
 352                 ZFS_ENTER(zfsvfs);
 353                 ZFS_VERIFY_ZP(zp);
 354 
 355                 /*
 356                  * Wait for all dirty blocks for this object
 357                  * to get synced out to disk, and the DMU info
 358                  * updated.
 359                  */
 360                 error = dmu_object_wait_synced(zfsvfs->z_os, zp->z_id);
 361                 if (error) {
 362                         ZFS_EXIT(zfsvfs);
 363                         return (error);
 364                 }
 365 
 366                 /*
 367                  * Retrieve fill count from DMU object.
 368                  */
 369                 error = dmu_object_info(zfsvfs->z_os, zp->z_id, &doi);
 370                 if (error) {
 371                         ZFS_EXIT(zfsvfs);
 372                         return (error);
 373                 }
 374 
 375                 ndata = doi.doi_fill_count;
 376 
 377                 ZFS_EXIT(zfsvfs);
 378                 if (ddi_copyout(&ndata, (void *)data, sizeof (ndata), flag))
 379                         return (SET_ERROR(EFAULT));
 380                 return (0);
 381         }
 382         }
 383         return (SET_ERROR(ENOTTY));
 384 }
 385 
 386 /*
 387  * Utility functions to map and unmap a single physical page.  These
 388  * are used to manage the mappable copies of ZFS file data, and therefore
 389  * do not update ref/mod bits.
 390  */
 391 caddr_t
 392 zfs_map_page(page_t *pp, enum seg_rw rw)
 393 {
 394         if (kpm_enable)
 395                 return (hat_kpm_mapin(pp, 0));
 396         ASSERT(rw == S_READ || rw == S_WRITE);
 397         return (ppmapin(pp, PROT_READ | ((rw == S_WRITE) ? PROT_WRITE : 0),
 398             (caddr_t)-1));
 399 }
 400 
 401 void
 402 zfs_unmap_page(page_t *pp, caddr_t addr)
 403 {
 404         if (kpm_enable) {
 405                 hat_kpm_mapout(pp, 0, addr);
 406         } else {
 407                 ppmapout(addr);
 408         }
 409 }
 410 
 411 /*
 412  * When a file is memory mapped, we must keep the IO data synchronized
 413  * between the DMU cache and the memory mapped pages.  What this means:
 414  *
 415  * On Write:    If we find a memory mapped page, we write to *both*
 416  *              the page and the dmu buffer.
 417  */
 418 static void
 419 update_pages(vnode_t *vp, int64_t start, int len, objset_t *os, uint64_t oid)
 420 {
 421         int64_t off;
 422 
 423         off = start & PAGEOFFSET;
 424         for (start &= PAGEMASK; len > 0; start += PAGESIZE) {
 425                 page_t *pp;
 426                 uint64_t nbytes = MIN(PAGESIZE - off, len);
 427 
 428                 if (pp = page_lookup(vp, start, SE_SHARED)) {
 429                         caddr_t va;
 430 
 431                         va = zfs_map_page(pp, S_WRITE);
 432                         (void) dmu_read(os, oid, start+off, nbytes, va+off,
 433                             DMU_READ_PREFETCH);
 434                         zfs_unmap_page(pp, va);
 435                         page_unlock(pp);
 436                 }
 437                 len -= nbytes;
 438                 off = 0;
 439         }
 440 }
 441 
 442 /*
 443  * When a file is memory mapped, we must keep the IO data synchronized
 444  * between the DMU cache and the memory mapped pages.  What this means:
 445  *
 446  * On Read:     We "read" preferentially from memory mapped pages,
 447  *              else we default from the dmu buffer.
 448  *
 449  * NOTE: We will always "break up" the IO into PAGESIZE uiomoves when
 450  *       the file is memory mapped.
 451  */
 452 static int
 453 mappedread(vnode_t *vp, int nbytes, uio_t *uio)
 454 {
 455         znode_t *zp = VTOZ(vp);
 456         int64_t start, off;
 457         int len = nbytes;
 458         int error = 0;
 459 
 460         start = uio->uio_loffset;
 461         off = start & PAGEOFFSET;
 462         for (start &= PAGEMASK; len > 0; start += PAGESIZE) {
 463                 page_t *pp;
 464                 uint64_t bytes = MIN(PAGESIZE - off, len);
 465 
 466                 if (pp = page_lookup(vp, start, SE_SHARED)) {
 467                         caddr_t va;
 468 
 469                         va = zfs_map_page(pp, S_READ);
 470                         error = uiomove(va + off, bytes, UIO_READ, uio);
 471                         zfs_unmap_page(pp, va);
 472                         page_unlock(pp);
 473                 } else {
 474                         error = dmu_read_uio_dbuf(sa_get_db(zp->z_sa_hdl),
 475                             uio, bytes);
 476                 }
 477                 len -= bytes;
 478                 off = 0;
 479                 if (error)
 480                         break;
 481         }
 482         return (error);
 483 }
 484 
 485 offset_t zfs_read_chunk_size = 1024 * 1024; /* Tunable */
 486 
 487 /*
 488  * Read bytes from specified file into supplied buffer.
 489  *
 490  *      IN:     vp      - vnode of file to be read from.
 491  *              uio     - structure supplying read location, range info,
 492  *                        and return buffer.
 493  *              ioflag  - SYNC flags; used to provide FRSYNC semantics.
 494  *              cr      - credentials of caller.
 495  *              ct      - caller context
 496  *
 497  *      OUT:    uio     - updated offset and range, buffer filled.
 498  *
 499  *      RETURN: 0 on success, error code on failure.
 500  *
 501  * Side Effects:
 502  *      vp - atime updated if byte count > 0
 503  */
 504 /* ARGSUSED */
 505 static int
 506 zfs_read(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cr, caller_context_t *ct)
 507 {
 508         znode_t         *zp = VTOZ(vp);
 509         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
 510         ssize_t         n, nbytes;
 511         int             error = 0;
 512         rl_t            *rl;
 513         xuio_t          *xuio = NULL;
 514 
 515         ZFS_ENTER(zfsvfs);
 516         ZFS_VERIFY_ZP(zp);
 517 
 518         if (zp->z_pflags & ZFS_AV_QUARANTINED) {
 519                 ZFS_EXIT(zfsvfs);
 520                 return (SET_ERROR(EACCES));
 521         }
 522 
 523         /*
 524          * Validate file offset
 525          */
 526         if (uio->uio_loffset < (offset_t)0) {
 527                 ZFS_EXIT(zfsvfs);
 528                 return (SET_ERROR(EINVAL));
 529         }
 530 
 531         /*
 532          * Fasttrack empty reads
 533          */
 534         if (uio->uio_resid == 0) {
 535                 ZFS_EXIT(zfsvfs);
 536                 return (0);
 537         }
 538 
 539         /*
 540          * Check for mandatory locks
 541          */
 542         if (MANDMODE(zp->z_mode)) {
 543                 if (error = chklock(vp, FREAD,
 544                     uio->uio_loffset, uio->uio_resid, uio->uio_fmode, ct)) {
 545                         ZFS_EXIT(zfsvfs);
 546                         return (error);
 547                 }
 548         }
 549 
 550         /*
 551          * If we're in FRSYNC mode, sync out this znode before reading it.
 552          */
 553         if (ioflag & FRSYNC || zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
 554                 zil_commit(zfsvfs->z_log, zp->z_id);
 555 
 556         /*
 557          * Lock the range against changes.
 558          */
 559         rl = zfs_range_lock(zp, uio->uio_loffset, uio->uio_resid, RL_READER);
 560 
 561         /*
 562          * If we are reading past end-of-file we can skip
 563          * to the end; but we might still need to set atime.
 564          */
 565         if (uio->uio_loffset >= zp->z_size) {
 566                 error = 0;
 567                 goto out;
 568         }
 569 
 570         ASSERT(uio->uio_loffset < zp->z_size);
 571         n = MIN(uio->uio_resid, zp->z_size - uio->uio_loffset);
 572 
 573         if ((uio->uio_extflg == UIO_XUIO) &&
 574             (((xuio_t *)uio)->xu_type == UIOTYPE_ZEROCOPY)) {
 575                 int nblk;
 576                 int blksz = zp->z_blksz;
 577                 uint64_t offset = uio->uio_loffset;
 578 
 579                 xuio = (xuio_t *)uio;
 580                 if ((ISP2(blksz))) {
 581                         nblk = (P2ROUNDUP(offset + n, blksz) - P2ALIGN(offset,
 582                             blksz)) / blksz;
 583                 } else {
 584                         ASSERT(offset + n <= blksz);
 585                         nblk = 1;
 586                 }
 587                 (void) dmu_xuio_init(xuio, nblk);
 588 
 589                 if (vn_has_cached_data(vp)) {
 590                         /*
 591                          * For simplicity, we always allocate a full buffer
 592                          * even if we only expect to read a portion of a block.
 593                          */
 594                         while (--nblk >= 0) {
 595                                 (void) dmu_xuio_add(xuio,
 596                                     dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
 597                                     blksz), 0, blksz);
 598                         }
 599                 }
 600         }
 601 
 602         while (n > 0) {
 603                 nbytes = MIN(n, zfs_read_chunk_size -
 604                     P2PHASE(uio->uio_loffset, zfs_read_chunk_size));
 605 
 606                 if (vn_has_cached_data(vp)) {
 607                         error = mappedread(vp, nbytes, uio);
 608                 } else {
 609                         error = dmu_read_uio_dbuf(sa_get_db(zp->z_sa_hdl),
 610                             uio, nbytes);
 611                 }
 612                 if (error) {
 613                         /* convert checksum errors into IO errors */
 614                         if (error == ECKSUM)
 615                                 error = SET_ERROR(EIO);
 616                         break;
 617                 }
 618 
 619                 n -= nbytes;
 620         }
 621 out:
 622         zfs_range_unlock(rl);
 623 
 624         ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
 625         ZFS_EXIT(zfsvfs);
 626         return (error);
 627 }
 628 
 629 /*
 630  * Write the bytes to a file.
 631  *
 632  *      IN:     vp      - vnode of file to be written to.
 633  *              uio     - structure supplying write location, range info,
 634  *                        and data buffer.
 635  *              ioflag  - FAPPEND, FSYNC, and/or FDSYNC.  FAPPEND is
 636  *                        set if in append mode.
 637  *              cr      - credentials of caller.
 638  *              ct      - caller context (NFS/CIFS fem monitor only)
 639  *
 640  *      OUT:    uio     - updated offset and range.
 641  *
 642  *      RETURN: 0 on success, error code on failure.
 643  *
 644  * Timestamps:
 645  *      vp - ctime|mtime updated if byte count > 0
 646  */
 647 
 648 /* ARGSUSED */
 649 static int
 650 zfs_write(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cr, caller_context_t *ct)
 651 {
 652         znode_t         *zp = VTOZ(vp);
 653         rlim64_t        limit = uio->uio_llimit;
 654         ssize_t         start_resid = uio->uio_resid;
 655         ssize_t         tx_bytes;
 656         uint64_t        end_size;
 657         dmu_tx_t        *tx;
 658         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
 659         zilog_t         *zilog;
 660         offset_t        woff;
 661         ssize_t         n, nbytes;
 662         rl_t            *rl;
 663         int             max_blksz = zfsvfs->z_max_blksz;
 664         int             error = 0;
 665         arc_buf_t       *abuf;
 666         iovec_t         *aiov = NULL;
 667         xuio_t          *xuio = NULL;
 668         int             i_iov = 0;
 669         int             iovcnt = uio->uio_iovcnt;
 670         iovec_t         *iovp = uio->uio_iov;
 671         int             write_eof;
 672         int             count = 0;
 673         sa_bulk_attr_t  bulk[4];
 674         uint64_t        mtime[2], ctime[2];
 675 
 676         /*
 677          * Fasttrack empty write
 678          */
 679         n = start_resid;
 680         if (n == 0)
 681                 return (0);
 682 
 683         if (limit == RLIM64_INFINITY || limit > MAXOFFSET_T)
 684                 limit = MAXOFFSET_T;
 685 
 686         ZFS_ENTER(zfsvfs);
 687         ZFS_VERIFY_ZP(zp);
 688 
 689         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL, &mtime, 16);
 690         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, &ctime, 16);
 691         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL,
 692             &zp->z_size, 8);
 693         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
 694             &zp->z_pflags, 8);
 695 
 696         /*
 697          * In a case vp->v_vfsp != zp->z_zfsvfs->z_vfs (e.g. snapshots) our
 698          * callers might not be able to detect properly that we are read-only,
 699          * so check it explicitly here.
 700          */
 701         if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
 702                 ZFS_EXIT(zfsvfs);
 703                 return (SET_ERROR(EROFS));
 704         }
 705 
 706         /*
 707          * If immutable or not appending then return EPERM
 708          */
 709         if ((zp->z_pflags & (ZFS_IMMUTABLE | ZFS_READONLY)) ||
 710             ((zp->z_pflags & ZFS_APPENDONLY) && !(ioflag & FAPPEND) &&
 711             (uio->uio_loffset < zp->z_size))) {
 712                 ZFS_EXIT(zfsvfs);
 713                 return (SET_ERROR(EPERM));
 714         }
 715 
 716         zilog = zfsvfs->z_log;
 717 
 718         /*
 719          * Validate file offset
 720          */
 721         woff = ioflag & FAPPEND ? zp->z_size : uio->uio_loffset;
 722         if (woff < 0) {
 723                 ZFS_EXIT(zfsvfs);
 724                 return (SET_ERROR(EINVAL));
 725         }
 726 
 727         /*
 728          * Check for mandatory locks before calling zfs_range_lock()
 729          * in order to prevent a deadlock with locks set via fcntl().
 730          */
 731         if (MANDMODE((mode_t)zp->z_mode) &&
 732             (error = chklock(vp, FWRITE, woff, n, uio->uio_fmode, ct)) != 0) {
 733                 ZFS_EXIT(zfsvfs);
 734                 return (error);
 735         }
 736 
 737         /*
 738          * Pre-fault the pages to ensure slow (eg NFS) pages
 739          * don't hold up txg.
 740          * Skip this if uio contains loaned arc_buf.
 741          */
 742         if ((uio->uio_extflg == UIO_XUIO) &&
 743             (((xuio_t *)uio)->xu_type == UIOTYPE_ZEROCOPY))
 744                 xuio = (xuio_t *)uio;
 745         else
 746                 uio_prefaultpages(MIN(n, max_blksz), uio);
 747 
 748         /*
 749          * If in append mode, set the io offset pointer to eof.
 750          */
 751         if (ioflag & FAPPEND) {
 752                 /*
 753                  * Obtain an appending range lock to guarantee file append
 754                  * semantics.  We reset the write offset once we have the lock.
 755                  */
 756                 rl = zfs_range_lock(zp, 0, n, RL_APPEND);
 757                 woff = rl->r_off;
 758                 if (rl->r_len == UINT64_MAX) {
 759                         /*
 760                          * We overlocked the file because this write will cause
 761                          * the file block size to increase.
 762                          * Note that zp_size cannot change with this lock held.
 763                          */
 764                         woff = zp->z_size;
 765                 }
 766                 uio->uio_loffset = woff;
 767         } else {
 768                 /*
 769                  * Note that if the file block size will change as a result of
 770                  * this write, then this range lock will lock the entire file
 771                  * so that we can re-write the block safely.
 772                  */
 773                 rl = zfs_range_lock(zp, woff, n, RL_WRITER);
 774         }
 775 
 776         if (woff >= limit) {
 777                 zfs_range_unlock(rl);
 778                 ZFS_EXIT(zfsvfs);
 779                 return (SET_ERROR(EFBIG));
 780         }
 781 
 782         if ((woff + n) > limit || woff > (limit - n))
 783                 n = limit - woff;
 784 
 785         /* Will this write extend the file length? */
 786         write_eof = (woff + n > zp->z_size);
 787 
 788         end_size = MAX(zp->z_size, woff + n);
 789 
 790         /*
 791          * Write the file in reasonable size chunks.  Each chunk is written
 792          * in a separate transaction; this keeps the intent log records small
 793          * and allows us to do more fine-grained space accounting.
 794          */
 795         while (n > 0) {
 796                 abuf = NULL;
 797                 woff = uio->uio_loffset;
 798                 if (zfs_owner_overquota(zfsvfs, zp, B_FALSE) ||
 799                     zfs_owner_overquota(zfsvfs, zp, B_TRUE)) {
 800                         if (abuf != NULL)
 801                                 dmu_return_arcbuf(abuf);
 802                         error = SET_ERROR(EDQUOT);
 803                         break;
 804                 }
 805 
 806                 if (xuio && abuf == NULL) {
 807                         ASSERT(i_iov < iovcnt);
 808                         aiov = &iovp[i_iov];
 809                         abuf = dmu_xuio_arcbuf(xuio, i_iov);
 810                         dmu_xuio_clear(xuio, i_iov);
 811                         DTRACE_PROBE3(zfs_cp_write, int, i_iov,
 812                             iovec_t *, aiov, arc_buf_t *, abuf);
 813                         ASSERT((aiov->iov_base == abuf->b_data) ||
 814                             ((char *)aiov->iov_base - (char *)abuf->b_data +
 815                             aiov->iov_len == arc_buf_size(abuf)));
 816                         i_iov++;
 817                 } else if (abuf == NULL && n >= max_blksz &&
 818                     woff >= zp->z_size &&
 819                     P2PHASE(woff, max_blksz) == 0 &&
 820                     zp->z_blksz == max_blksz) {
 821                         /*
 822                          * This write covers a full block.  "Borrow" a buffer
 823                          * from the dmu so that we can fill it before we enter
 824                          * a transaction.  This avoids the possibility of
 825                          * holding up the transaction if the data copy hangs
 826                          * up on a pagefault (e.g., from an NFS server mapping).
 827                          */
 828                         size_t cbytes;
 829 
 830                         abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
 831                             max_blksz);
 832                         ASSERT(abuf != NULL);
 833                         ASSERT(arc_buf_size(abuf) == max_blksz);
 834                         if (error = uiocopy(abuf->b_data, max_blksz,
 835                             UIO_WRITE, uio, &cbytes)) {
 836                                 dmu_return_arcbuf(abuf);
 837                                 break;
 838                         }
 839                         ASSERT(cbytes == max_blksz);
 840                 }
 841 
 842                 /*
 843                  * Start a transaction.
 844                  */
 845                 tx = dmu_tx_create(zfsvfs->z_os);
 846                 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
 847                 dmu_tx_hold_write(tx, zp->z_id, woff, MIN(n, max_blksz));
 848                 zfs_sa_upgrade_txholds(tx, zp);
 849                 error = dmu_tx_assign(tx, TXG_WAIT);
 850                 if (error) {
 851                         dmu_tx_abort(tx);
 852                         if (abuf != NULL)
 853                                 dmu_return_arcbuf(abuf);
 854                         break;
 855                 }
 856 
 857                 /*
 858                  * If zfs_range_lock() over-locked we grow the blocksize
 859                  * and then reduce the lock range.  This will only happen
 860                  * on the first iteration since zfs_range_reduce() will
 861                  * shrink down r_len to the appropriate size.
 862                  */
 863                 if (rl->r_len == UINT64_MAX) {
 864                         uint64_t new_blksz;
 865 
 866                         if (zp->z_blksz > max_blksz) {
 867                                 /*
 868                                  * File's blocksize is already larger than the
 869                                  * "recordsize" property.  Only let it grow to
 870                                  * the next power of 2.
 871                                  */
 872                                 ASSERT(!ISP2(zp->z_blksz));
 873                                 new_blksz = MIN(end_size,
 874                                     1 << highbit64(zp->z_blksz));
 875                         } else {
 876                                 new_blksz = MIN(end_size, max_blksz);
 877                         }
 878                         zfs_grow_blocksize(zp, new_blksz, tx);
 879                         zfs_range_reduce(rl, woff, n);
 880                 }
 881 
 882                 /*
 883                  * XXX - should we really limit each write to z_max_blksz?
 884                  * Perhaps we should use SPA_MAXBLOCKSIZE chunks?
 885                  */
 886                 nbytes = MIN(n, max_blksz - P2PHASE(woff, max_blksz));
 887 
 888                 if (abuf == NULL) {
 889                         tx_bytes = uio->uio_resid;
 890                         error = dmu_write_uio_dbuf(sa_get_db(zp->z_sa_hdl),
 891                             uio, nbytes, tx);
 892                         tx_bytes -= uio->uio_resid;
 893                 } else {
 894                         tx_bytes = nbytes;
 895                         ASSERT(xuio == NULL || tx_bytes == aiov->iov_len);
 896                         /*
 897                          * If this is not a full block write, but we are
 898                          * extending the file past EOF and this data starts
 899                          * block-aligned, use assign_arcbuf().  Otherwise,
 900                          * write via dmu_write().
 901                          */
 902                         if (tx_bytes < max_blksz && (!write_eof ||
 903                             aiov->iov_base != abuf->b_data)) {
 904                                 ASSERT(xuio);
 905                                 dmu_write(zfsvfs->z_os, zp->z_id, woff,
 906                                     aiov->iov_len, aiov->iov_base, tx);
 907                                 dmu_return_arcbuf(abuf);
 908                                 xuio_stat_wbuf_copied();
 909                         } else {
 910                                 ASSERT(xuio || tx_bytes == max_blksz);
 911                                 dmu_assign_arcbuf(sa_get_db(zp->z_sa_hdl),
 912                                     woff, abuf, tx);
 913                         }
 914                         ASSERT(tx_bytes <= uio->uio_resid);
 915                         uioskip(uio, tx_bytes);
 916                 }
 917                 if (tx_bytes && vn_has_cached_data(vp)) {
 918                         update_pages(vp, woff,
 919                             tx_bytes, zfsvfs->z_os, zp->z_id);
 920                 }
 921 
 922                 /*
 923                  * If we made no progress, we're done.  If we made even
 924                  * partial progress, update the znode and ZIL accordingly.
 925                  */
 926                 if (tx_bytes == 0) {
 927                         (void) sa_update(zp->z_sa_hdl, SA_ZPL_SIZE(zfsvfs),
 928                             (void *)&zp->z_size, sizeof (uint64_t), tx);
 929                         dmu_tx_commit(tx);
 930                         ASSERT(error != 0);
 931                         break;
 932                 }
 933 
 934                 /*
 935                  * Clear Set-UID/Set-GID bits on successful write if not
 936                  * privileged and at least one of the excute bits is set.
 937                  *
 938                  * It would be nice to to this after all writes have
 939                  * been done, but that would still expose the ISUID/ISGID
 940                  * to another app after the partial write is committed.
 941                  *
 942                  * Note: we don't call zfs_fuid_map_id() here because
 943                  * user 0 is not an ephemeral uid.
 944                  */
 945                 mutex_enter(&zp->z_acl_lock);
 946                 if ((zp->z_mode & (S_IXUSR | (S_IXUSR >> 3) |
 947                     (S_IXUSR >> 6))) != 0 &&
 948                     (zp->z_mode & (S_ISUID | S_ISGID)) != 0 &&
 949                     secpolicy_vnode_setid_retain(cr,
 950                     (zp->z_mode & S_ISUID) != 0 && zp->z_uid == 0) != 0) {
 951                         uint64_t newmode;
 952                         zp->z_mode &= ~(S_ISUID | S_ISGID);
 953                         newmode = zp->z_mode;
 954                         (void) sa_update(zp->z_sa_hdl, SA_ZPL_MODE(zfsvfs),
 955                             (void *)&newmode, sizeof (uint64_t), tx);
 956                 }
 957                 mutex_exit(&zp->z_acl_lock);
 958 
 959                 zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime,
 960                     B_TRUE);
 961 
 962                 /*
 963                  * Update the file size (zp_size) if it has changed;
 964                  * account for possible concurrent updates.
 965                  */
 966                 while ((end_size = zp->z_size) < uio->uio_loffset) {
 967                         (void) atomic_cas_64(&zp->z_size, end_size,
 968                             uio->uio_loffset);
 969                         ASSERT(error == 0);
 970                 }
 971                 /*
 972                  * If we are replaying and eof is non zero then force
 973                  * the file size to the specified eof. Note, there's no
 974                  * concurrency during replay.
 975                  */
 976                 if (zfsvfs->z_replay && zfsvfs->z_replay_eof != 0)
 977                         zp->z_size = zfsvfs->z_replay_eof;
 978 
 979                 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
 980 
 981                 zfs_log_write(zilog, tx, TX_WRITE, zp, woff, tx_bytes, ioflag);
 982                 dmu_tx_commit(tx);
 983 
 984                 if (error != 0)
 985                         break;
 986                 ASSERT(tx_bytes == nbytes);
 987                 n -= nbytes;
 988 
 989                 if (!xuio && n > 0)
 990                         uio_prefaultpages(MIN(n, max_blksz), uio);
 991         }
 992 
 993         zfs_range_unlock(rl);
 994 
 995         /*
 996          * If we're in replay mode, or we made no progress, return error.
 997          * Otherwise, it's at least a partial write, so it's successful.
 998          */
 999         if (zfsvfs->z_replay || uio->uio_resid == start_resid) {
1000                 ZFS_EXIT(zfsvfs);
1001                 return (error);
1002         }
1003 
1004         if (ioflag & (FSYNC | FDSYNC) ||
1005             zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
1006                 zil_commit(zilog, zp->z_id);
1007 
1008         ZFS_EXIT(zfsvfs);
1009         return (0);
1010 }
1011 
1012 void
1013 zfs_get_done(zgd_t *zgd, int error)
1014 {
1015         znode_t *zp = zgd->zgd_private;
1016         objset_t *os = zp->z_zfsvfs->z_os;
1017 
1018         if (zgd->zgd_db)
1019                 dmu_buf_rele(zgd->zgd_db, zgd);
1020 
1021         zfs_range_unlock(zgd->zgd_rl);
1022 
1023         /*
1024          * Release the vnode asynchronously as we currently have the
1025          * txg stopped from syncing.
1026          */
1027         VN_RELE_ASYNC(ZTOV(zp), dsl_pool_vnrele_taskq(dmu_objset_pool(os)));
1028 
1029         if (error == 0 && zgd->zgd_bp)
1030                 zil_add_block(zgd->zgd_zilog, zgd->zgd_bp);
1031 
1032         kmem_free(zgd, sizeof (zgd_t));
1033 }
1034 
1035 #ifdef DEBUG
1036 static int zil_fault_io = 0;
1037 #endif
1038 
1039 /*
1040  * Get data to generate a TX_WRITE intent log record.
1041  */
1042 int
1043 zfs_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
1044 {
1045         zfsvfs_t *zfsvfs = arg;
1046         objset_t *os = zfsvfs->z_os;
1047         znode_t *zp;
1048         uint64_t object = lr->lr_foid;
1049         uint64_t offset = lr->lr_offset;
1050         uint64_t size = lr->lr_length;
1051         blkptr_t *bp = &lr->lr_blkptr;
1052         dmu_buf_t *db;
1053         zgd_t *zgd;
1054         int error = 0;
1055 
1056         ASSERT(zio != NULL);
1057         ASSERT(size != 0);
1058 
1059         /*
1060          * Nothing to do if the file has been removed
1061          */
1062         if (zfs_zget(zfsvfs, object, &zp) != 0)
1063                 return (SET_ERROR(ENOENT));
1064         if (zp->z_unlinked) {
1065                 /*
1066                  * Release the vnode asynchronously as we currently have the
1067                  * txg stopped from syncing.
1068                  */
1069                 VN_RELE_ASYNC(ZTOV(zp),
1070                     dsl_pool_vnrele_taskq(dmu_objset_pool(os)));
1071                 return (SET_ERROR(ENOENT));
1072         }
1073 
1074         zgd = (zgd_t *)kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
1075         zgd->zgd_zilog = zfsvfs->z_log;
1076         zgd->zgd_private = zp;
1077 
1078         /*
1079          * Write records come in two flavors: immediate and indirect.
1080          * For small writes it's cheaper to store the data with the
1081          * log record (immediate); for large writes it's cheaper to
1082          * sync the data and get a pointer to it (indirect) so that
1083          * we don't have to write the data twice.
1084          */
1085         if (buf != NULL) { /* immediate write */
1086                 zgd->zgd_rl = zfs_range_lock(zp, offset, size, RL_READER);
1087                 /* test for truncation needs to be done while range locked */
1088                 if (offset >= zp->z_size) {
1089                         error = SET_ERROR(ENOENT);
1090                 } else {
1091                         error = dmu_read(os, object, offset, size, buf,
1092                             DMU_READ_NO_PREFETCH);
1093                 }
1094                 ASSERT(error == 0 || error == ENOENT);
1095         } else { /* indirect write */
1096                 /*
1097                  * Have to lock the whole block to ensure when it's
1098                  * written out and it's checksum is being calculated
1099                  * that no one can change the data. We need to re-check
1100                  * blocksize after we get the lock in case it's changed!
1101                  */
1102                 for (;;) {
1103                         uint64_t blkoff;
1104                         size = zp->z_blksz;
1105                         blkoff = ISP2(size) ? P2PHASE(offset, size) : offset;
1106                         offset -= blkoff;
1107                         zgd->zgd_rl = zfs_range_lock(zp, offset, size,
1108                             RL_READER);
1109                         if (zp->z_blksz == size)
1110                                 break;
1111                         offset += blkoff;
1112                         zfs_range_unlock(zgd->zgd_rl);
1113                 }
1114                 /* test for truncation needs to be done while range locked */
1115                 if (lr->lr_offset >= zp->z_size)
1116                         error = SET_ERROR(ENOENT);
1117 #ifdef DEBUG
1118                 if (zil_fault_io) {
1119                         error = SET_ERROR(EIO);
1120                         zil_fault_io = 0;
1121                 }
1122 #endif
1123                 if (error == 0)
1124                         error = dmu_buf_hold(os, object, offset, zgd, &db,
1125                             DMU_READ_NO_PREFETCH);
1126 
1127                 if (error == 0) {
1128                         blkptr_t *obp = dmu_buf_get_blkptr(db);
1129                         if (obp) {
1130                                 ASSERT(BP_IS_HOLE(bp));
1131                                 *bp = *obp;
1132                         }
1133 
1134                         zgd->zgd_db = db;
1135                         zgd->zgd_bp = bp;
1136 
1137                         ASSERT(db->db_offset == offset);
1138                         ASSERT(db->db_size == size);
1139 
1140                         error = dmu_sync(zio, lr->lr_common.lrc_txg,
1141                             zfs_get_done, zgd);
1142                         ASSERT(error || lr->lr_length <= zp->z_blksz);
1143 
1144                         /*
1145                          * On success, we need to wait for the write I/O
1146                          * initiated by dmu_sync() to complete before we can
1147                          * release this dbuf.  We will finish everything up
1148                          * in the zfs_get_done() callback.
1149                          */
1150                         if (error == 0)
1151                                 return (0);
1152 
1153                         if (error == EALREADY) {
1154                                 lr->lr_common.lrc_txtype = TX_WRITE2;
1155                                 error = 0;
1156                         }
1157                 }
1158         }
1159 
1160         zfs_get_done(zgd, error);
1161 
1162         return (error);
1163 }
1164 
1165 /*ARGSUSED*/
1166 static int
1167 zfs_access(vnode_t *vp, int mode, int flag, cred_t *cr,
1168     caller_context_t *ct)
1169 {
1170         znode_t *zp = VTOZ(vp);
1171         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
1172         int error;
1173 
1174         ZFS_ENTER(zfsvfs);
1175         ZFS_VERIFY_ZP(zp);
1176 
1177         if (flag & V_ACE_MASK)
1178                 error = zfs_zaccess(zp, mode, flag, B_FALSE, cr);
1179         else
1180                 error = zfs_zaccess_rwx(zp, mode, flag, cr);
1181 
1182         ZFS_EXIT(zfsvfs);
1183         return (error);
1184 }
1185 
1186 /*
1187  * If vnode is for a device return a specfs vnode instead.
1188  */
1189 static int
1190 specvp_check(vnode_t **vpp, cred_t *cr)
1191 {
1192         int error = 0;
1193 
1194         if (IS_DEVVP(*vpp)) {
1195                 struct vnode *svp;
1196 
1197                 svp = specvp(*vpp, (*vpp)->v_rdev, (*vpp)->v_type, cr);
1198                 VN_RELE(*vpp);
1199                 if (svp == NULL)
1200                         error = SET_ERROR(ENOSYS);
1201                 *vpp = svp;
1202         }
1203         return (error);
1204 }
1205 
1206 
1207 /*
1208  * Lookup an entry in a directory, or an extended attribute directory.
1209  * If it exists, return a held vnode reference for it.
1210  *
1211  *      IN:     dvp     - vnode of directory to search.
1212  *              nm      - name of entry to lookup.
1213  *              pnp     - full pathname to lookup [UNUSED].
1214  *              flags   - LOOKUP_XATTR set if looking for an attribute.
1215  *              rdir    - root directory vnode [UNUSED].
1216  *              cr      - credentials of caller.
1217  *              ct      - caller context
1218  *              direntflags - directory lookup flags
1219  *              realpnp - returned pathname.
1220  *
1221  *      OUT:    vpp     - vnode of located entry, NULL if not found.
1222  *
1223  *      RETURN: 0 on success, error code on failure.
1224  *
1225  * Timestamps:
1226  *      NA
1227  */
1228 /* ARGSUSED */
1229 static int
1230 zfs_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, struct pathname *pnp,
1231     int flags, vnode_t *rdir, cred_t *cr,  caller_context_t *ct,
1232     int *direntflags, pathname_t *realpnp)
1233 {
1234         znode_t *zdp = VTOZ(dvp);
1235         zfsvfs_t *zfsvfs = zdp->z_zfsvfs;
1236         int     error = 0;
1237 
1238         /* fast path */
1239         if (!(flags & (LOOKUP_XATTR | FIGNORECASE))) {
1240 
1241                 if (dvp->v_type != VDIR) {
1242                         return (SET_ERROR(ENOTDIR));
1243                 } else if (zdp->z_sa_hdl == NULL) {
1244                         return (SET_ERROR(EIO));
1245                 }
1246 
1247                 if (nm[0] == 0 || (nm[0] == '.' && nm[1] == '\0')) {
1248                         error = zfs_fastaccesschk_execute(zdp, cr);
1249                         if (!error) {
1250                                 *vpp = dvp;
1251                                 VN_HOLD(*vpp);
1252                                 return (0);
1253                         }
1254                         return (error);
1255                 } else {
1256                         vnode_t *tvp = dnlc_lookup(dvp, nm);
1257 
1258                         if (tvp) {
1259                                 error = zfs_fastaccesschk_execute(zdp, cr);
1260                                 if (error) {
1261                                         VN_RELE(tvp);
1262                                         return (error);
1263                                 }
1264                                 if (tvp == DNLC_NO_VNODE) {
1265                                         VN_RELE(tvp);
1266                                         return (SET_ERROR(ENOENT));
1267                                 } else {
1268                                         *vpp = tvp;
1269                                         return (specvp_check(vpp, cr));
1270                                 }
1271                         }
1272                 }
1273         }
1274 
1275         DTRACE_PROBE2(zfs__fastpath__lookup__miss, vnode_t *, dvp, char *, nm);
1276 
1277         ZFS_ENTER(zfsvfs);
1278         ZFS_VERIFY_ZP(zdp);
1279 
1280         *vpp = NULL;
1281 
1282         if (flags & LOOKUP_XATTR) {
1283                 /*
1284                  * If the xattr property is off, refuse the lookup request.
1285                  */
1286                 if (!(zfsvfs->z_vfs->vfs_flag & VFS_XATTR)) {
1287                         ZFS_EXIT(zfsvfs);
1288                         return (SET_ERROR(EINVAL));
1289                 }
1290 
1291                 /*
1292                  * We don't allow recursive attributes..
1293                  * Maybe someday we will.
1294                  */
1295                 if (zdp->z_pflags & ZFS_XATTR) {
1296                         ZFS_EXIT(zfsvfs);
1297                         return (SET_ERROR(EINVAL));
1298                 }
1299 
1300                 if (error = zfs_get_xattrdir(VTOZ(dvp), vpp, cr, flags)) {
1301                         ZFS_EXIT(zfsvfs);
1302                         return (error);
1303                 }
1304 
1305                 /*
1306                  * Do we have permission to get into attribute directory?
1307                  */
1308 
1309                 if (error = zfs_zaccess(VTOZ(*vpp), ACE_EXECUTE, 0,
1310                     B_FALSE, cr)) {
1311                         VN_RELE(*vpp);
1312                         *vpp = NULL;
1313                 }
1314 
1315                 ZFS_EXIT(zfsvfs);
1316                 return (error);
1317         }
1318 
1319         if (dvp->v_type != VDIR) {
1320                 ZFS_EXIT(zfsvfs);
1321                 return (SET_ERROR(ENOTDIR));
1322         }
1323 
1324         /*
1325          * Check accessibility of directory.
1326          */
1327 
1328         if (error = zfs_zaccess(zdp, ACE_EXECUTE, 0, B_FALSE, cr)) {
1329                 ZFS_EXIT(zfsvfs);
1330                 return (error);
1331         }
1332 
1333         if (zfsvfs->z_utf8 && u8_validate(nm, strlen(nm),
1334             NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
1335                 ZFS_EXIT(zfsvfs);
1336                 return (SET_ERROR(EILSEQ));
1337         }
1338 
1339         error = zfs_dirlook(zdp, nm, vpp, flags, direntflags, realpnp);
1340         if (error == 0)
1341                 error = specvp_check(vpp, cr);
1342 
1343         ZFS_EXIT(zfsvfs);
1344         return (error);
1345 }
1346 
1347 /*
1348  * Attempt to create a new entry in a directory.  If the entry
1349  * already exists, truncate the file if permissible, else return
1350  * an error.  Return the vp of the created or trunc'd file.
1351  *
1352  *      IN:     dvp     - vnode of directory to put new file entry in.
1353  *              name    - name of new file entry.
1354  *              vap     - attributes of new file.
1355  *              excl    - flag indicating exclusive or non-exclusive mode.
1356  *              mode    - mode to open file with.
1357  *              cr      - credentials of caller.
1358  *              flag    - large file flag [UNUSED].
1359  *              ct      - caller context
1360  *              vsecp   - ACL to be set
1361  *
1362  *      OUT:    vpp     - vnode of created or trunc'd entry.
1363  *
1364  *      RETURN: 0 on success, error code on failure.
1365  *
1366  * Timestamps:
1367  *      dvp - ctime|mtime updated if new entry created
1368  *       vp - ctime|mtime always, atime if new
1369  */
1370 
1371 /* ARGSUSED */
1372 static int
1373 zfs_create(vnode_t *dvp, char *name, vattr_t *vap, vcexcl_t excl,
1374     int mode, vnode_t **vpp, cred_t *cr, int flag, caller_context_t *ct,
1375     vsecattr_t *vsecp)
1376 {
1377         znode_t         *zp, *dzp = VTOZ(dvp);
1378         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
1379         zilog_t         *zilog;
1380         objset_t        *os;
1381         zfs_dirlock_t   *dl;
1382         dmu_tx_t        *tx;
1383         int             error;
1384         ksid_t          *ksid;
1385         uid_t           uid;
1386         gid_t           gid = crgetgid(cr);
1387         zfs_acl_ids_t   acl_ids;
1388         boolean_t       fuid_dirtied;
1389         boolean_t       have_acl = B_FALSE;
1390         boolean_t       waited = B_FALSE;
1391 
1392         /*
1393          * If we have an ephemeral id, ACL, or XVATTR then
1394          * make sure file system is at proper version
1395          */
1396 
1397         ksid = crgetsid(cr, KSID_OWNER);
1398         if (ksid)
1399                 uid = ksid_getid(ksid);
1400         else
1401                 uid = crgetuid(cr);
1402 
1403         if (zfsvfs->z_use_fuids == B_FALSE &&
1404             (vsecp || (vap->va_mask & AT_XVATTR) ||
1405             IS_EPHEMERAL(uid) || IS_EPHEMERAL(gid)))
1406                 return (SET_ERROR(EINVAL));
1407 
1408         ZFS_ENTER(zfsvfs);
1409         ZFS_VERIFY_ZP(dzp);
1410         os = zfsvfs->z_os;
1411         zilog = zfsvfs->z_log;
1412 
1413         if (zfsvfs->z_utf8 && u8_validate(name, strlen(name),
1414             NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
1415                 ZFS_EXIT(zfsvfs);
1416                 return (SET_ERROR(EILSEQ));
1417         }
1418 
1419         if (vap->va_mask & AT_XVATTR) {
1420                 if ((error = secpolicy_xvattr((xvattr_t *)vap,
1421                     crgetuid(cr), cr, vap->va_type)) != 0) {
1422                         ZFS_EXIT(zfsvfs);
1423                         return (error);
1424                 }
1425         }
1426 top:
1427         *vpp = NULL;
1428 
1429         if ((vap->va_mode & VSVTX) && secpolicy_vnode_stky_modify(cr))
1430                 vap->va_mode &= ~VSVTX;
1431 
1432         if (*name == '\0') {
1433                 /*
1434                  * Null component name refers to the directory itself.
1435                  */
1436                 VN_HOLD(dvp);
1437                 zp = dzp;
1438                 dl = NULL;
1439                 error = 0;
1440         } else {
1441                 /* possible VN_HOLD(zp) */
1442                 int zflg = 0;
1443 
1444                 if (flag & FIGNORECASE)
1445                         zflg |= ZCILOOK;
1446 
1447                 error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
1448                     NULL, NULL);
1449                 if (error) {
1450                         if (have_acl)
1451                                 zfs_acl_ids_free(&acl_ids);
1452                         if (strcmp(name, "..") == 0)
1453                                 error = SET_ERROR(EISDIR);
1454                         ZFS_EXIT(zfsvfs);
1455                         return (error);
1456                 }
1457         }
1458 
1459         if (zp == NULL) {
1460                 uint64_t txtype;
1461 
1462                 /*
1463                  * Create a new file object and update the directory
1464                  * to reference it.
1465                  */
1466                 if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
1467                         if (have_acl)
1468                                 zfs_acl_ids_free(&acl_ids);
1469                         goto out;
1470                 }
1471 
1472                 /*
1473                  * We only support the creation of regular files in
1474                  * extended attribute directories.
1475                  */
1476 
1477                 if ((dzp->z_pflags & ZFS_XATTR) &&
1478                     (vap->va_type != VREG)) {
1479                         if (have_acl)
1480                                 zfs_acl_ids_free(&acl_ids);
1481                         error = SET_ERROR(EINVAL);
1482                         goto out;
1483                 }
1484 
1485                 if (!have_acl && (error = zfs_acl_ids_create(dzp, 0, vap,
1486                     cr, vsecp, &acl_ids)) != 0)
1487                         goto out;
1488                 have_acl = B_TRUE;
1489 
1490                 if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
1491                         zfs_acl_ids_free(&acl_ids);
1492                         error = SET_ERROR(EDQUOT);
1493                         goto out;
1494                 }
1495 
1496                 tx = dmu_tx_create(os);
1497 
1498                 dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
1499                     ZFS_SA_BASE_ATTR_SIZE);
1500 
1501                 fuid_dirtied = zfsvfs->z_fuid_dirty;
1502                 if (fuid_dirtied)
1503                         zfs_fuid_txhold(zfsvfs, tx);
1504                 dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
1505                 dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
1506                 if (!zfsvfs->z_use_sa &&
1507                     acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
1508                         dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
1509                             0, acl_ids.z_aclp->z_acl_bytes);
1510                 }
1511                 error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
1512                 if (error) {
1513                         zfs_dirent_unlock(dl);
1514                         if (error == ERESTART) {
1515                                 waited = B_TRUE;
1516                                 dmu_tx_wait(tx);
1517                                 dmu_tx_abort(tx);
1518                                 goto top;
1519                         }
1520                         zfs_acl_ids_free(&acl_ids);
1521                         dmu_tx_abort(tx);
1522                         ZFS_EXIT(zfsvfs);
1523                         return (error);
1524                 }
1525                 zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
1526 
1527                 if (fuid_dirtied)
1528                         zfs_fuid_sync(zfsvfs, tx);
1529 
1530                 (void) zfs_link_create(dl, zp, tx, ZNEW);
1531                 txtype = zfs_log_create_txtype(Z_FILE, vsecp, vap);
1532                 if (flag & FIGNORECASE)
1533                         txtype |= TX_CI;
1534                 zfs_log_create(zilog, tx, txtype, dzp, zp, name,
1535                     vsecp, acl_ids.z_fuidp, vap);
1536                 zfs_acl_ids_free(&acl_ids);
1537                 dmu_tx_commit(tx);
1538         } else {
1539                 int aflags = (flag & FAPPEND) ? V_APPEND : 0;
1540 
1541                 if (have_acl)
1542                         zfs_acl_ids_free(&acl_ids);
1543                 have_acl = B_FALSE;
1544 
1545                 /*
1546                  * A directory entry already exists for this name.
1547                  */
1548                 /*
1549                  * Can't truncate an existing file if in exclusive mode.
1550                  */
1551                 if (excl == EXCL) {
1552                         error = SET_ERROR(EEXIST);
1553                         goto out;
1554                 }
1555                 /*
1556                  * Can't open a directory for writing.
1557                  */
1558                 if ((ZTOV(zp)->v_type == VDIR) && (mode & S_IWRITE)) {
1559                         error = SET_ERROR(EISDIR);
1560                         goto out;
1561                 }
1562                 /*
1563                  * Verify requested access to file.
1564                  */
1565                 if (mode && (error = zfs_zaccess_rwx(zp, mode, aflags, cr))) {
1566                         goto out;
1567                 }
1568 
1569                 mutex_enter(&dzp->z_lock);
1570                 dzp->z_seq++;
1571                 mutex_exit(&dzp->z_lock);
1572 
1573                 /*
1574                  * Truncate regular files if requested.
1575                  */
1576                 if ((ZTOV(zp)->v_type == VREG) &&
1577                     (vap->va_mask & AT_SIZE) && (vap->va_size == 0)) {
1578                         /* we can't hold any locks when calling zfs_freesp() */
1579                         zfs_dirent_unlock(dl);
1580                         dl = NULL;
1581                         error = zfs_freesp(zp, 0, 0, mode, TRUE);
1582                         if (error == 0) {
1583                                 vnevent_create(ZTOV(zp), ct);
1584                         }
1585                 }
1586         }
1587 out:
1588 
1589         if (dl)
1590                 zfs_dirent_unlock(dl);
1591 
1592         if (error) {
1593                 if (zp)
1594                         VN_RELE(ZTOV(zp));
1595         } else {
1596                 *vpp = ZTOV(zp);
1597                 error = specvp_check(vpp, cr);
1598         }
1599 
1600         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
1601                 zil_commit(zilog, 0);
1602 
1603         ZFS_EXIT(zfsvfs);
1604         return (error);
1605 }
1606 
1607 /*
1608  * Remove an entry from a directory.
1609  *
1610  *      IN:     dvp     - vnode of directory to remove entry from.
1611  *              name    - name of entry to remove.
1612  *              cr      - credentials of caller.
1613  *              ct      - caller context
1614  *              flags   - case flags
1615  *
1616  *      RETURN: 0 on success, error code on failure.
1617  *
1618  * Timestamps:
1619  *      dvp - ctime|mtime
1620  *       vp - ctime (if nlink > 0)
1621  */
1622 
1623 uint64_t null_xattr = 0;
1624 
1625 /*ARGSUSED*/
1626 static int
1627 zfs_remove(vnode_t *dvp, char *name, cred_t *cr, caller_context_t *ct,
1628     int flags)
1629 {
1630         znode_t         *zp, *dzp = VTOZ(dvp);
1631         znode_t         *xzp;
1632         vnode_t         *vp;
1633         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
1634         zilog_t         *zilog;
1635         uint64_t        acl_obj, xattr_obj;
1636         uint64_t        xattr_obj_unlinked = 0;
1637         uint64_t        obj = 0;
1638         zfs_dirlock_t   *dl;
1639         dmu_tx_t        *tx;
1640         boolean_t       may_delete_now, delete_now = FALSE;
1641         boolean_t       unlinked, toobig = FALSE;
1642         uint64_t        txtype;
1643         pathname_t      *realnmp = NULL;
1644         pathname_t      realnm;
1645         int             error;
1646         int             zflg = ZEXISTS;
1647         boolean_t       waited = B_FALSE;
1648 
1649         ZFS_ENTER(zfsvfs);
1650         ZFS_VERIFY_ZP(dzp);
1651         zilog = zfsvfs->z_log;
1652 
1653         if (flags & FIGNORECASE) {
1654                 zflg |= ZCILOOK;
1655                 pn_alloc(&realnm);
1656                 realnmp = &realnm;
1657         }
1658 
1659 top:
1660         xattr_obj = 0;
1661         xzp = NULL;
1662         /*
1663          * Attempt to lock directory; fail if entry doesn't exist.
1664          */
1665         if (error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
1666             NULL, realnmp)) {
1667                 if (realnmp)
1668                         pn_free(realnmp);
1669                 ZFS_EXIT(zfsvfs);
1670                 return (error);
1671         }
1672 
1673         vp = ZTOV(zp);
1674 
1675         if (error = zfs_zaccess_delete(dzp, zp, cr)) {
1676                 goto out;
1677         }
1678 
1679         /*
1680          * Need to use rmdir for removing directories.
1681          */
1682         if (vp->v_type == VDIR) {
1683                 error = SET_ERROR(EPERM);
1684                 goto out;
1685         }
1686 
1687         vnevent_remove(vp, dvp, name, ct);
1688 
1689         if (realnmp)
1690                 dnlc_remove(dvp, realnmp->pn_buf);
1691         else
1692                 dnlc_remove(dvp, name);
1693 
1694         mutex_enter(&vp->v_lock);
1695         may_delete_now = vp->v_count == 1 && !vn_has_cached_data(vp);
1696         mutex_exit(&vp->v_lock);
1697 
1698         /*
1699          * We may delete the znode now, or we may put it in the unlinked set;
1700          * it depends on whether we're the last link, and on whether there are
1701          * other holds on the vnode.  So we dmu_tx_hold() the right things to
1702          * allow for either case.
1703          */
1704         obj = zp->z_id;
1705         tx = dmu_tx_create(zfsvfs->z_os);
1706         dmu_tx_hold_zap(tx, dzp->z_id, FALSE, name);
1707         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
1708         zfs_sa_upgrade_txholds(tx, zp);
1709         zfs_sa_upgrade_txholds(tx, dzp);
1710         if (may_delete_now) {
1711                 toobig =
1712                     zp->z_size > zp->z_blksz * DMU_MAX_DELETEBLKCNT;
1713                 /* if the file is too big, only hold_free a token amount */
1714                 dmu_tx_hold_free(tx, zp->z_id, 0,
1715                     (toobig ? DMU_MAX_ACCESS : DMU_OBJECT_END));
1716         }
1717 
1718         /* are there any extended attributes? */
1719         error = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
1720             &xattr_obj, sizeof (xattr_obj));
1721         if (error == 0 && xattr_obj) {
1722                 error = zfs_zget(zfsvfs, xattr_obj, &xzp);
1723                 ASSERT0(error);
1724                 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
1725                 dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
1726         }
1727 
1728         mutex_enter(&zp->z_lock);
1729         if ((acl_obj = zfs_external_acl(zp)) != 0 && may_delete_now)
1730                 dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END);
1731         mutex_exit(&zp->z_lock);
1732 
1733         /* charge as an update -- would be nice not to charge at all */
1734         dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
1735 
1736         /*
1737          * Mark this transaction as typically resulting in a net free of
1738          * space, unless object removal will be delayed indefinitely
1739          * (due to active holds on the vnode due to the file being open).
1740          */
1741         if (may_delete_now)
1742                 dmu_tx_mark_netfree(tx);
1743 
1744         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
1745         if (error) {
1746                 zfs_dirent_unlock(dl);
1747                 VN_RELE(vp);
1748                 if (xzp)
1749                         VN_RELE(ZTOV(xzp));
1750                 if (error == ERESTART) {
1751                         waited = B_TRUE;
1752                         dmu_tx_wait(tx);
1753                         dmu_tx_abort(tx);
1754                         goto top;
1755                 }
1756                 if (realnmp)
1757                         pn_free(realnmp);
1758                 dmu_tx_abort(tx);
1759                 ZFS_EXIT(zfsvfs);
1760                 return (error);
1761         }
1762 
1763         /*
1764          * Remove the directory entry.
1765          */
1766         error = zfs_link_destroy(dl, zp, tx, zflg, &unlinked);
1767 
1768         if (error) {
1769                 dmu_tx_commit(tx);
1770                 goto out;
1771         }
1772 
1773         if (unlinked) {
1774                 /*
1775                  * Hold z_lock so that we can make sure that the ACL obj
1776                  * hasn't changed.  Could have been deleted due to
1777                  * zfs_sa_upgrade().
1778                  */
1779                 mutex_enter(&zp->z_lock);
1780                 mutex_enter(&vp->v_lock);
1781                 (void) sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
1782                     &xattr_obj_unlinked, sizeof (xattr_obj_unlinked));
1783                 delete_now = may_delete_now && !toobig &&
1784                     vp->v_count == 1 && !vn_has_cached_data(vp) &&
1785                     xattr_obj == xattr_obj_unlinked && zfs_external_acl(zp) ==
1786                     acl_obj;
1787                 mutex_exit(&vp->v_lock);
1788         }
1789 
1790         if (delete_now) {
1791                 if (xattr_obj_unlinked) {
1792                         ASSERT3U(xzp->z_links, ==, 2);
1793                         mutex_enter(&xzp->z_lock);
1794                         xzp->z_unlinked = 1;
1795                         xzp->z_links = 0;
1796                         error = sa_update(xzp->z_sa_hdl, SA_ZPL_LINKS(zfsvfs),
1797                             &xzp->z_links, sizeof (xzp->z_links), tx);
1798                         ASSERT3U(error,  ==,  0);
1799                         mutex_exit(&xzp->z_lock);
1800                         zfs_unlinked_add(xzp, tx);
1801 
1802                         if (zp->z_is_sa)
1803                                 error = sa_remove(zp->z_sa_hdl,
1804                                     SA_ZPL_XATTR(zfsvfs), tx);
1805                         else
1806                                 error = sa_update(zp->z_sa_hdl,
1807                                     SA_ZPL_XATTR(zfsvfs), &null_xattr,
1808                                     sizeof (uint64_t), tx);
1809                         ASSERT0(error);
1810                 }
1811                 mutex_enter(&vp->v_lock);
1812                 vp->v_count--;
1813                 ASSERT0(vp->v_count);
1814                 mutex_exit(&vp->v_lock);
1815                 mutex_exit(&zp->z_lock);
1816                 zfs_znode_delete(zp, tx);
1817         } else if (unlinked) {
1818                 mutex_exit(&zp->z_lock);
1819                 zfs_unlinked_add(zp, tx);
1820         }
1821 
1822         txtype = TX_REMOVE;
1823         if (flags & FIGNORECASE)
1824                 txtype |= TX_CI;
1825         zfs_log_remove(zilog, tx, txtype, dzp, name, obj);
1826 
1827         dmu_tx_commit(tx);
1828 out:
1829         if (realnmp)
1830                 pn_free(realnmp);
1831 
1832         zfs_dirent_unlock(dl);
1833 
1834         if (!delete_now)
1835                 VN_RELE(vp);
1836         if (xzp)
1837                 VN_RELE(ZTOV(xzp));
1838 
1839         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
1840                 zil_commit(zilog, 0);
1841 
1842         ZFS_EXIT(zfsvfs);
1843         return (error);
1844 }
1845 
1846 /*
1847  * Create a new directory and insert it into dvp using the name
1848  * provided.  Return a pointer to the inserted directory.
1849  *
1850  *      IN:     dvp     - vnode of directory to add subdir to.
1851  *              dirname - name of new directory.
1852  *              vap     - attributes of new directory.
1853  *              cr      - credentials of caller.
1854  *              ct      - caller context
1855  *              flags   - case flags
1856  *              vsecp   - ACL to be set
1857  *
1858  *      OUT:    vpp     - vnode of created directory.
1859  *
1860  *      RETURN: 0 on success, error code on failure.
1861  *
1862  * Timestamps:
1863  *      dvp - ctime|mtime updated
1864  *       vp - ctime|mtime|atime updated
1865  */
1866 /*ARGSUSED*/
1867 static int
1868 zfs_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp, cred_t *cr,
1869     caller_context_t *ct, int flags, vsecattr_t *vsecp)
1870 {
1871         znode_t         *zp, *dzp = VTOZ(dvp);
1872         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
1873         zilog_t         *zilog;
1874         zfs_dirlock_t   *dl;
1875         uint64_t        txtype;
1876         dmu_tx_t        *tx;
1877         int             error;
1878         int             zf = ZNEW;
1879         ksid_t          *ksid;
1880         uid_t           uid;
1881         gid_t           gid = crgetgid(cr);
1882         zfs_acl_ids_t   acl_ids;
1883         boolean_t       fuid_dirtied;
1884         boolean_t       waited = B_FALSE;
1885 
1886         ASSERT(vap->va_type == VDIR);
1887 
1888         /*
1889          * If we have an ephemeral id, ACL, or XVATTR then
1890          * make sure file system is at proper version
1891          */
1892 
1893         ksid = crgetsid(cr, KSID_OWNER);
1894         if (ksid)
1895                 uid = ksid_getid(ksid);
1896         else
1897                 uid = crgetuid(cr);
1898         if (zfsvfs->z_use_fuids == B_FALSE &&
1899             (vsecp || (vap->va_mask & AT_XVATTR) ||
1900             IS_EPHEMERAL(uid) || IS_EPHEMERAL(gid)))
1901                 return (SET_ERROR(EINVAL));
1902 
1903         ZFS_ENTER(zfsvfs);
1904         ZFS_VERIFY_ZP(dzp);
1905         zilog = zfsvfs->z_log;
1906 
1907         if (dzp->z_pflags & ZFS_XATTR) {
1908                 ZFS_EXIT(zfsvfs);
1909                 return (SET_ERROR(EINVAL));
1910         }
1911 
1912         if (zfsvfs->z_utf8 && u8_validate(dirname,
1913             strlen(dirname), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
1914                 ZFS_EXIT(zfsvfs);
1915                 return (SET_ERROR(EILSEQ));
1916         }
1917         if (flags & FIGNORECASE)
1918                 zf |= ZCILOOK;
1919 
1920         if (vap->va_mask & AT_XVATTR) {
1921                 if ((error = secpolicy_xvattr((xvattr_t *)vap,
1922                     crgetuid(cr), cr, vap->va_type)) != 0) {
1923                         ZFS_EXIT(zfsvfs);
1924                         return (error);
1925                 }
1926         }
1927 
1928         if ((error = zfs_acl_ids_create(dzp, 0, vap, cr,
1929             vsecp, &acl_ids)) != 0) {
1930                 ZFS_EXIT(zfsvfs);
1931                 return (error);
1932         }
1933         /*
1934          * First make sure the new directory doesn't exist.
1935          *
1936          * Existence is checked first to make sure we don't return
1937          * EACCES instead of EEXIST which can cause some applications
1938          * to fail.
1939          */
1940 top:
1941         *vpp = NULL;
1942 
1943         if (error = zfs_dirent_lock(&dl, dzp, dirname, &zp, zf,
1944             NULL, NULL)) {
1945                 zfs_acl_ids_free(&acl_ids);
1946                 ZFS_EXIT(zfsvfs);
1947                 return (error);
1948         }
1949 
1950         if (error = zfs_zaccess(dzp, ACE_ADD_SUBDIRECTORY, 0, B_FALSE, cr)) {
1951                 zfs_acl_ids_free(&acl_ids);
1952                 zfs_dirent_unlock(dl);
1953                 ZFS_EXIT(zfsvfs);
1954                 return (error);
1955         }
1956 
1957         if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
1958                 zfs_acl_ids_free(&acl_ids);
1959                 zfs_dirent_unlock(dl);
1960                 ZFS_EXIT(zfsvfs);
1961                 return (SET_ERROR(EDQUOT));
1962         }
1963 
1964         /*
1965          * Add a new entry to the directory.
1966          */
1967         tx = dmu_tx_create(zfsvfs->z_os);
1968         dmu_tx_hold_zap(tx, dzp->z_id, TRUE, dirname);
1969         dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
1970         fuid_dirtied = zfsvfs->z_fuid_dirty;
1971         if (fuid_dirtied)
1972                 zfs_fuid_txhold(zfsvfs, tx);
1973         if (!zfsvfs->z_use_sa && acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
1974                 dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
1975                     acl_ids.z_aclp->z_acl_bytes);
1976         }
1977 
1978         dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
1979             ZFS_SA_BASE_ATTR_SIZE);
1980 
1981         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
1982         if (error) {
1983                 zfs_dirent_unlock(dl);
1984                 if (error == ERESTART) {
1985                         waited = B_TRUE;
1986                         dmu_tx_wait(tx);
1987                         dmu_tx_abort(tx);
1988                         goto top;
1989                 }
1990                 zfs_acl_ids_free(&acl_ids);
1991                 dmu_tx_abort(tx);
1992                 ZFS_EXIT(zfsvfs);
1993                 return (error);
1994         }
1995 
1996         /*
1997          * Create new node.
1998          */
1999         zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
2000 
2001         if (fuid_dirtied)
2002                 zfs_fuid_sync(zfsvfs, tx);
2003 
2004         /*
2005          * Now put new name in parent dir.
2006          */
2007         (void) zfs_link_create(dl, zp, tx, ZNEW);
2008 
2009         *vpp = ZTOV(zp);
2010 
2011         txtype = zfs_log_create_txtype(Z_DIR, vsecp, vap);
2012         if (flags & FIGNORECASE)
2013                 txtype |= TX_CI;
2014         zfs_log_create(zilog, tx, txtype, dzp, zp, dirname, vsecp,
2015             acl_ids.z_fuidp, vap);
2016 
2017         zfs_acl_ids_free(&acl_ids);
2018 
2019         dmu_tx_commit(tx);
2020 
2021         zfs_dirent_unlock(dl);
2022 
2023         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
2024                 zil_commit(zilog, 0);
2025 
2026         ZFS_EXIT(zfsvfs);
2027         return (0);
2028 }
2029 
2030 /*
2031  * Remove a directory subdir entry.  If the current working
2032  * directory is the same as the subdir to be removed, the
2033  * remove will fail.
2034  *
2035  *      IN:     dvp     - vnode of directory to remove from.
2036  *              name    - name of directory to be removed.
2037  *              cwd     - vnode of current working directory.
2038  *              cr      - credentials of caller.
2039  *              ct      - caller context
2040  *              flags   - case flags
2041  *
2042  *      RETURN: 0 on success, error code on failure.
2043  *
2044  * Timestamps:
2045  *      dvp - ctime|mtime updated
2046  */
2047 /*ARGSUSED*/
2048 static int
2049 zfs_rmdir(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr,
2050     caller_context_t *ct, int flags)
2051 {
2052         znode_t         *dzp = VTOZ(dvp);
2053         znode_t         *zp;
2054         vnode_t         *vp;
2055         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
2056         zilog_t         *zilog;
2057         zfs_dirlock_t   *dl;
2058         dmu_tx_t        *tx;
2059         int             error;
2060         int             zflg = ZEXISTS;
2061         boolean_t       waited = B_FALSE;
2062 
2063         ZFS_ENTER(zfsvfs);
2064         ZFS_VERIFY_ZP(dzp);
2065         zilog = zfsvfs->z_log;
2066 
2067         if (flags & FIGNORECASE)
2068                 zflg |= ZCILOOK;
2069 top:
2070         zp = NULL;
2071 
2072         /*
2073          * Attempt to lock directory; fail if entry doesn't exist.
2074          */
2075         if (error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
2076             NULL, NULL)) {
2077                 ZFS_EXIT(zfsvfs);
2078                 return (error);
2079         }
2080 
2081         vp = ZTOV(zp);
2082 
2083         if (error = zfs_zaccess_delete(dzp, zp, cr)) {
2084                 goto out;
2085         }
2086 
2087         if (vp->v_type != VDIR) {
2088                 error = SET_ERROR(ENOTDIR);
2089                 goto out;
2090         }
2091 
2092         if (vp == cwd) {
2093                 error = SET_ERROR(EINVAL);
2094                 goto out;
2095         }
2096 
2097         vnevent_rmdir(vp, dvp, name, ct);
2098 
2099         /*
2100          * Grab a lock on the directory to make sure that noone is
2101          * trying to add (or lookup) entries while we are removing it.
2102          */
2103         rw_enter(&zp->z_name_lock, RW_WRITER);
2104 
2105         /*
2106          * Grab a lock on the parent pointer to make sure we play well
2107          * with the treewalk and directory rename code.
2108          */
2109         rw_enter(&zp->z_parent_lock, RW_WRITER);
2110 
2111         tx = dmu_tx_create(zfsvfs->z_os);
2112         dmu_tx_hold_zap(tx, dzp->z_id, FALSE, name);
2113         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
2114         dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
2115         zfs_sa_upgrade_txholds(tx, zp);
2116         zfs_sa_upgrade_txholds(tx, dzp);
2117         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
2118         if (error) {
2119                 rw_exit(&zp->z_parent_lock);
2120                 rw_exit(&zp->z_name_lock);
2121                 zfs_dirent_unlock(dl);
2122                 VN_RELE(vp);
2123                 if (error == ERESTART) {
2124                         waited = B_TRUE;
2125                         dmu_tx_wait(tx);
2126                         dmu_tx_abort(tx);
2127                         goto top;
2128                 }
2129                 dmu_tx_abort(tx);
2130                 ZFS_EXIT(zfsvfs);
2131                 return (error);
2132         }
2133 
2134         error = zfs_link_destroy(dl, zp, tx, zflg, NULL);
2135 
2136         if (error == 0) {
2137                 uint64_t txtype = TX_RMDIR;
2138                 if (flags & FIGNORECASE)
2139                         txtype |= TX_CI;
2140                 zfs_log_remove(zilog, tx, txtype, dzp, name, ZFS_NO_OBJECT);
2141         }
2142 
2143         dmu_tx_commit(tx);
2144 
2145         rw_exit(&zp->z_parent_lock);
2146         rw_exit(&zp->z_name_lock);
2147 out:
2148         zfs_dirent_unlock(dl);
2149 
2150         VN_RELE(vp);
2151 
2152         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
2153                 zil_commit(zilog, 0);
2154 
2155         ZFS_EXIT(zfsvfs);
2156         return (error);
2157 }
2158 
2159 /*
2160  * Read as many directory entries as will fit into the provided
2161  * buffer from the given directory cursor position (specified in
2162  * the uio structure).
2163  *
2164  *      IN:     vp      - vnode of directory to read.
2165  *              uio     - structure supplying read location, range info,
2166  *                        and return buffer.
2167  *              cr      - credentials of caller.
2168  *              ct      - caller context
2169  *              flags   - case flags
2170  *
2171  *      OUT:    uio     - updated offset and range, buffer filled.
2172  *              eofp    - set to true if end-of-file detected.
2173  *
2174  *      RETURN: 0 on success, error code on failure.
2175  *
2176  * Timestamps:
2177  *      vp - atime updated
2178  *
2179  * Note that the low 4 bits of the cookie returned by zap is always zero.
2180  * This allows us to use the low range for "special" directory entries:
2181  * We use 0 for '.', and 1 for '..'.  If this is the root of the filesystem,
2182  * we use the offset 2 for the '.zfs' directory.
2183  */
2184 /* ARGSUSED */
2185 static int
2186 zfs_readdir(vnode_t *vp, uio_t *uio, cred_t *cr, int *eofp,
2187     caller_context_t *ct, int flags)
2188 {
2189         znode_t         *zp = VTOZ(vp);
2190         iovec_t         *iovp;
2191         edirent_t       *eodp;
2192         dirent64_t      *odp;
2193         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
2194         objset_t        *os;
2195         caddr_t         outbuf;
2196         size_t          bufsize;
2197         zap_cursor_t    zc;
2198         zap_attribute_t zap;
2199         uint_t          bytes_wanted;
2200         uint64_t        offset; /* must be unsigned; checks for < 1 */
2201         uint64_t        parent;
2202         int             local_eof;
2203         int             outcount;
2204         int             error;
2205         uint8_t         prefetch;
2206         boolean_t       check_sysattrs;
2207 
2208         ZFS_ENTER(zfsvfs);
2209         ZFS_VERIFY_ZP(zp);
2210 
2211         if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
2212             &parent, sizeof (parent))) != 0) {
2213                 ZFS_EXIT(zfsvfs);
2214                 return (error);
2215         }
2216 
2217         /*
2218          * If we are not given an eof variable,
2219          * use a local one.
2220          */
2221         if (eofp == NULL)
2222                 eofp = &local_eof;
2223 
2224         /*
2225          * Check for valid iov_len.
2226          */
2227         if (uio->uio_iov->iov_len <= 0) {
2228                 ZFS_EXIT(zfsvfs);
2229                 return (SET_ERROR(EINVAL));
2230         }
2231 
2232         /*
2233          * Quit if directory has been removed (posix)
2234          */
2235         if ((*eofp = zp->z_unlinked) != 0) {
2236                 ZFS_EXIT(zfsvfs);
2237                 return (0);
2238         }
2239 
2240         error = 0;
2241         os = zfsvfs->z_os;
2242         offset = uio->uio_loffset;
2243         prefetch = zp->z_zn_prefetch;
2244 
2245         /*
2246          * Initialize the iterator cursor.
2247          */
2248         if (offset <= 3) {
2249                 /*
2250                  * Start iteration from the beginning of the directory.
2251                  */
2252                 zap_cursor_init(&zc, os, zp->z_id);
2253         } else {
2254                 /*
2255                  * The offset is a serialized cursor.
2256                  */
2257                 zap_cursor_init_serialized(&zc, os, zp->z_id, offset);
2258         }
2259 
2260         /*
2261          * Get space to change directory entries into fs independent format.
2262          */
2263         iovp = uio->uio_iov;
2264         bytes_wanted = iovp->iov_len;
2265         if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1) {
2266                 bufsize = bytes_wanted;
2267                 outbuf = kmem_alloc(bufsize, KM_SLEEP);
2268                 odp = (struct dirent64 *)outbuf;
2269         } else {
2270                 bufsize = bytes_wanted;
2271                 outbuf = NULL;
2272                 odp = (struct dirent64 *)iovp->iov_base;
2273         }
2274         eodp = (struct edirent *)odp;
2275 
2276         /*
2277          * If this VFS supports the system attribute view interface; and
2278          * we're looking at an extended attribute directory; and we care
2279          * about normalization conflicts on this vfs; then we must check
2280          * for normalization conflicts with the sysattr name space.
2281          */
2282         check_sysattrs = vfs_has_feature(vp->v_vfsp, VFSFT_SYSATTR_VIEWS) &&
2283             (vp->v_flag & V_XATTRDIR) && zfsvfs->z_norm &&
2284             (flags & V_RDDIR_ENTFLAGS);
2285 
2286         /*
2287          * Transform to file-system independent format
2288          */
2289         outcount = 0;
2290         while (outcount < bytes_wanted) {
2291                 ino64_t objnum;
2292                 ushort_t reclen;
2293                 off64_t *next = NULL;
2294 
2295                 /*
2296                  * Special case `.', `..', and `.zfs'.
2297                  */
2298                 if (offset == 0) {
2299                         (void) strcpy(zap.za_name, ".");
2300                         zap.za_normalization_conflict = 0;
2301                         objnum = zp->z_id;
2302                 } else if (offset == 1) {
2303                         (void) strcpy(zap.za_name, "..");
2304                         zap.za_normalization_conflict = 0;
2305                         objnum = parent;
2306                 } else if (offset == 2 && zfs_show_ctldir(zp)) {
2307                         (void) strcpy(zap.za_name, ZFS_CTLDIR_NAME);
2308                         zap.za_normalization_conflict = 0;
2309                         objnum = ZFSCTL_INO_ROOT;
2310                 } else {
2311                         /*
2312                          * Grab next entry.
2313                          */
2314                         if (error = zap_cursor_retrieve(&zc, &zap)) {
2315                                 if ((*eofp = (error == ENOENT)) != 0)
2316                                         break;
2317                                 else
2318                                         goto update;
2319                         }
2320 
2321                         if (zap.za_integer_length != 8 ||
2322                             zap.za_num_integers != 1) {
2323                                 cmn_err(CE_WARN, "zap_readdir: bad directory "
2324                                     "entry, obj = %lld, offset = %lld\n",
2325                                     (u_longlong_t)zp->z_id,
2326                                     (u_longlong_t)offset);
2327                                 error = SET_ERROR(ENXIO);
2328                                 goto update;
2329                         }
2330 
2331                         objnum = ZFS_DIRENT_OBJ(zap.za_first_integer);
2332                         /*
2333                          * MacOS X can extract the object type here such as:
2334                          * uint8_t type = ZFS_DIRENT_TYPE(zap.za_first_integer);
2335                          */
2336 
2337                         if (check_sysattrs && !zap.za_normalization_conflict) {
2338                                 zap.za_normalization_conflict =
2339                                     xattr_sysattr_casechk(zap.za_name);
2340                         }
2341                 }
2342 
2343                 if (flags & V_RDDIR_ACCFILTER) {
2344                         /*
2345                          * If we have no access at all, don't include
2346                          * this entry in the returned information
2347                          */
2348                         znode_t *ezp;
2349                         if (zfs_zget(zp->z_zfsvfs, objnum, &ezp) != 0)
2350                                 goto skip_entry;
2351                         if (!zfs_has_access(ezp, cr)) {
2352                                 VN_RELE(ZTOV(ezp));
2353                                 goto skip_entry;
2354                         }
2355                         VN_RELE(ZTOV(ezp));
2356                 }
2357 
2358                 if (flags & V_RDDIR_ENTFLAGS)
2359                         reclen = EDIRENT_RECLEN(strlen(zap.za_name));
2360                 else
2361                         reclen = DIRENT64_RECLEN(strlen(zap.za_name));
2362 
2363                 /*
2364                  * Will this entry fit in the buffer?
2365                  */
2366                 if (outcount + reclen > bufsize) {
2367                         /*
2368                          * Did we manage to fit anything in the buffer?
2369                          */
2370                         if (!outcount) {
2371                                 error = SET_ERROR(EINVAL);
2372                                 goto update;
2373                         }
2374                         break;
2375                 }
2376                 if (flags & V_RDDIR_ENTFLAGS) {
2377                         /*
2378                          * Add extended flag entry:
2379                          */
2380                         eodp->ed_ino = objnum;
2381                         eodp->ed_reclen = reclen;
2382                         /* NOTE: ed_off is the offset for the *next* entry */
2383                         next = &(eodp->ed_off);
2384                         eodp->ed_eflags = zap.za_normalization_conflict ?
2385                             ED_CASE_CONFLICT : 0;
2386                         (void) strncpy(eodp->ed_name, zap.za_name,
2387                             EDIRENT_NAMELEN(reclen));
2388                         eodp = (edirent_t *)((intptr_t)eodp + reclen);
2389                 } else {
2390                         /*
2391                          * Add normal entry:
2392                          */
2393                         odp->d_ino = objnum;
2394                         odp->d_reclen = reclen;
2395                         /* NOTE: d_off is the offset for the *next* entry */
2396                         next = &(odp->d_off);
2397                         (void) strncpy(odp->d_name, zap.za_name,
2398                             DIRENT64_NAMELEN(reclen));
2399                         odp = (dirent64_t *)((intptr_t)odp + reclen);
2400                 }
2401                 outcount += reclen;
2402 
2403                 ASSERT(outcount <= bufsize);
2404 
2405                 /* Prefetch znode */
2406                 if (prefetch)
2407                         dmu_prefetch(os, objnum, 0, 0);
2408 
2409         skip_entry:
2410                 /*
2411                  * Move to the next entry, fill in the previous offset.
2412                  */
2413                 if (offset > 2 || (offset == 2 && !zfs_show_ctldir(zp))) {
2414                         zap_cursor_advance(&zc);
2415                         offset = zap_cursor_serialize(&zc);
2416                 } else {
2417                         offset += 1;
2418                 }
2419                 if (next)
2420                         *next = offset;
2421         }
2422         zp->z_zn_prefetch = B_FALSE; /* a lookup will re-enable pre-fetching */
2423 
2424         if (uio->uio_segflg == UIO_SYSSPACE && uio->uio_iovcnt == 1) {
2425                 iovp->iov_base += outcount;
2426                 iovp->iov_len -= outcount;
2427                 uio->uio_resid -= outcount;
2428         } else if (error = uiomove(outbuf, (long)outcount, UIO_READ, uio)) {
2429                 /*
2430                  * Reset the pointer.
2431                  */
2432                 offset = uio->uio_loffset;
2433         }
2434 
2435 update:
2436         zap_cursor_fini(&zc);
2437         if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1)
2438                 kmem_free(outbuf, bufsize);
2439 
2440         if (error == ENOENT)
2441                 error = 0;
2442 
2443         ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
2444 
2445         uio->uio_loffset = offset;
2446         ZFS_EXIT(zfsvfs);
2447         return (error);
2448 }
2449 
2450 ulong_t zfs_fsync_sync_cnt = 4;
2451 
2452 static int
2453 zfs_fsync(vnode_t *vp, int syncflag, cred_t *cr, caller_context_t *ct)
2454 {
2455         znode_t *zp = VTOZ(vp);
2456         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
2457 
2458         /*
2459          * Regardless of whether this is required for standards conformance,
2460          * this is the logical behavior when fsync() is called on a file with
2461          * dirty pages.  We use B_ASYNC since the ZIL transactions are already
2462          * going to be pushed out as part of the zil_commit().
2463          */
2464         if (vn_has_cached_data(vp) && !(syncflag & FNODSYNC) &&
2465             (vp->v_type == VREG) && !(IS_SWAPVP(vp)))
2466                 (void) VOP_PUTPAGE(vp, (offset_t)0, (size_t)0, B_ASYNC, cr, ct);
2467 
2468         (void) tsd_set(zfs_fsyncer_key, (void *)zfs_fsync_sync_cnt);
2469 
2470         if (zfsvfs->z_os->os_sync != ZFS_SYNC_DISABLED) {
2471                 ZFS_ENTER(zfsvfs);
2472                 ZFS_VERIFY_ZP(zp);
2473                 zil_commit(zfsvfs->z_log, zp->z_id);
2474                 ZFS_EXIT(zfsvfs);
2475         }
2476         return (0);
2477 }
2478 
2479 
2480 /*
2481  * Get the requested file attributes and place them in the provided
2482  * vattr structure.
2483  *
2484  *      IN:     vp      - vnode of file.
2485  *              vap     - va_mask identifies requested attributes.
2486  *                        If AT_XVATTR set, then optional attrs are requested
2487  *              flags   - ATTR_NOACLCHECK (CIFS server context)
2488  *              cr      - credentials of caller.
2489  *              ct      - caller context
2490  *
2491  *      OUT:    vap     - attribute values.
2492  *
2493  *      RETURN: 0 (always succeeds).
2494  */
2495 /* ARGSUSED */
2496 static int
2497 zfs_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
2498     caller_context_t *ct)
2499 {
2500         znode_t *zp = VTOZ(vp);
2501         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
2502         int     error = 0;
2503         uint64_t links;
2504         uint64_t mtime[2], ctime[2];
2505         xvattr_t *xvap = (xvattr_t *)vap;       /* vap may be an xvattr_t * */
2506         xoptattr_t *xoap = NULL;
2507         boolean_t skipaclchk = (flags & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
2508         sa_bulk_attr_t bulk[2];
2509         int count = 0;
2510 
2511         ZFS_ENTER(zfsvfs);
2512         ZFS_VERIFY_ZP(zp);
2513 
2514         zfs_fuid_map_ids(zp, cr, &vap->va_uid, &vap->va_gid);
2515 
2516         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL, &mtime, 16);
2517         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, &ctime, 16);
2518 
2519         if ((error = sa_bulk_lookup(zp->z_sa_hdl, bulk, count)) != 0) {
2520                 ZFS_EXIT(zfsvfs);
2521                 return (error);
2522         }
2523 
2524         /*
2525          * If ACL is trivial don't bother looking for ACE_READ_ATTRIBUTES.
2526          * Also, if we are the owner don't bother, since owner should
2527          * always be allowed to read basic attributes of file.
2528          */
2529         if (!(zp->z_pflags & ZFS_ACL_TRIVIAL) &&
2530             (vap->va_uid != crgetuid(cr))) {
2531                 if (error = zfs_zaccess(zp, ACE_READ_ATTRIBUTES, 0,
2532                     skipaclchk, cr)) {
2533                         ZFS_EXIT(zfsvfs);
2534                         return (error);
2535                 }
2536         }
2537 
2538         /*
2539          * Return all attributes.  It's cheaper to provide the answer
2540          * than to determine whether we were asked the question.
2541          */
2542 
2543         mutex_enter(&zp->z_lock);
2544         vap->va_type = vp->v_type;
2545         vap->va_mode = zp->z_mode & MODEMASK;
2546         vap->va_fsid = zp->z_zfsvfs->z_vfs->vfs_dev;
2547         vap->va_nodeid = zp->z_id;
2548         if ((vp->v_flag & VROOT) && zfs_show_ctldir(zp))
2549                 links = zp->z_links + 1;
2550         else
2551                 links = zp->z_links;
2552         vap->va_nlink = MIN(links, UINT32_MAX);      /* nlink_t limit! */
2553         vap->va_size = zp->z_size;
2554         vap->va_rdev = vp->v_rdev;
2555         vap->va_seq = zp->z_seq;
2556 
2557         /*
2558          * Add in any requested optional attributes and the create time.
2559          * Also set the corresponding bits in the returned attribute bitmap.
2560          */
2561         if ((xoap = xva_getxoptattr(xvap)) != NULL && zfsvfs->z_use_fuids) {
2562                 if (XVA_ISSET_REQ(xvap, XAT_ARCHIVE)) {
2563                         xoap->xoa_archive =
2564                             ((zp->z_pflags & ZFS_ARCHIVE) != 0);
2565                         XVA_SET_RTN(xvap, XAT_ARCHIVE);
2566                 }
2567 
2568                 if (XVA_ISSET_REQ(xvap, XAT_READONLY)) {
2569                         xoap->xoa_readonly =
2570                             ((zp->z_pflags & ZFS_READONLY) != 0);
2571                         XVA_SET_RTN(xvap, XAT_READONLY);
2572                 }
2573 
2574                 if (XVA_ISSET_REQ(xvap, XAT_SYSTEM)) {
2575                         xoap->xoa_system =
2576                             ((zp->z_pflags & ZFS_SYSTEM) != 0);
2577                         XVA_SET_RTN(xvap, XAT_SYSTEM);
2578                 }
2579 
2580                 if (XVA_ISSET_REQ(xvap, XAT_HIDDEN)) {
2581                         xoap->xoa_hidden =
2582                             ((zp->z_pflags & ZFS_HIDDEN) != 0);
2583                         XVA_SET_RTN(xvap, XAT_HIDDEN);
2584                 }
2585 
2586                 if (XVA_ISSET_REQ(xvap, XAT_NOUNLINK)) {
2587                         xoap->xoa_nounlink =
2588                             ((zp->z_pflags & ZFS_NOUNLINK) != 0);
2589                         XVA_SET_RTN(xvap, XAT_NOUNLINK);
2590                 }
2591 
2592                 if (XVA_ISSET_REQ(xvap, XAT_IMMUTABLE)) {
2593                         xoap->xoa_immutable =
2594                             ((zp->z_pflags & ZFS_IMMUTABLE) != 0);
2595                         XVA_SET_RTN(xvap, XAT_IMMUTABLE);
2596                 }
2597 
2598                 if (XVA_ISSET_REQ(xvap, XAT_APPENDONLY)) {
2599                         xoap->xoa_appendonly =
2600                             ((zp->z_pflags & ZFS_APPENDONLY) != 0);
2601                         XVA_SET_RTN(xvap, XAT_APPENDONLY);
2602                 }
2603 
2604                 if (XVA_ISSET_REQ(xvap, XAT_NODUMP)) {
2605                         xoap->xoa_nodump =
2606                             ((zp->z_pflags & ZFS_NODUMP) != 0);
2607                         XVA_SET_RTN(xvap, XAT_NODUMP);
2608                 }
2609 
2610                 if (XVA_ISSET_REQ(xvap, XAT_OPAQUE)) {
2611                         xoap->xoa_opaque =
2612                             ((zp->z_pflags & ZFS_OPAQUE) != 0);
2613                         XVA_SET_RTN(xvap, XAT_OPAQUE);
2614                 }
2615 
2616                 if (XVA_ISSET_REQ(xvap, XAT_AV_QUARANTINED)) {
2617                         xoap->xoa_av_quarantined =
2618                             ((zp->z_pflags & ZFS_AV_QUARANTINED) != 0);
2619                         XVA_SET_RTN(xvap, XAT_AV_QUARANTINED);
2620                 }
2621 
2622                 if (XVA_ISSET_REQ(xvap, XAT_AV_MODIFIED)) {
2623                         xoap->xoa_av_modified =
2624                             ((zp->z_pflags & ZFS_AV_MODIFIED) != 0);
2625                         XVA_SET_RTN(xvap, XAT_AV_MODIFIED);
2626                 }
2627 
2628                 if (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP) &&
2629                     vp->v_type == VREG) {
2630                         zfs_sa_get_scanstamp(zp, xvap);
2631                 }
2632 
2633                 if (XVA_ISSET_REQ(xvap, XAT_CREATETIME)) {
2634                         uint64_t times[2];
2635 
2636                         (void) sa_lookup(zp->z_sa_hdl, SA_ZPL_CRTIME(zfsvfs),
2637                             times, sizeof (times));
2638                         ZFS_TIME_DECODE(&xoap->xoa_createtime, times);
2639                         XVA_SET_RTN(xvap, XAT_CREATETIME);
2640                 }
2641 
2642                 if (XVA_ISSET_REQ(xvap, XAT_REPARSE)) {
2643                         xoap->xoa_reparse = ((zp->z_pflags & ZFS_REPARSE) != 0);
2644                         XVA_SET_RTN(xvap, XAT_REPARSE);
2645                 }
2646                 if (XVA_ISSET_REQ(xvap, XAT_GEN)) {
2647                         xoap->xoa_generation = zp->z_gen;
2648                         XVA_SET_RTN(xvap, XAT_GEN);
2649                 }
2650 
2651                 if (XVA_ISSET_REQ(xvap, XAT_OFFLINE)) {
2652                         xoap->xoa_offline =
2653                             ((zp->z_pflags & ZFS_OFFLINE) != 0);
2654                         XVA_SET_RTN(xvap, XAT_OFFLINE);
2655                 }
2656 
2657                 if (XVA_ISSET_REQ(xvap, XAT_SPARSE)) {
2658                         xoap->xoa_sparse =
2659                             ((zp->z_pflags & ZFS_SPARSE) != 0);
2660                         XVA_SET_RTN(xvap, XAT_SPARSE);
2661                 }
2662         }
2663 
2664         ZFS_TIME_DECODE(&vap->va_atime, zp->z_atime);
2665         ZFS_TIME_DECODE(&vap->va_mtime, mtime);
2666         ZFS_TIME_DECODE(&vap->va_ctime, ctime);
2667 
2668         mutex_exit(&zp->z_lock);
2669 
2670         sa_object_size(zp->z_sa_hdl, &vap->va_blksize, &vap->va_nblocks);
2671 
2672         if (zp->z_blksz == 0) {
2673                 /*
2674                  * Block size hasn't been set; suggest maximal I/O transfers.
2675                  */
2676                 vap->va_blksize = zfsvfs->z_max_blksz;
2677         }
2678 
2679         ZFS_EXIT(zfsvfs);
2680         return (0);
2681 }
2682 
2683 /*
2684  * Set the file attributes to the values contained in the
2685  * vattr structure.
2686  *
2687  *      IN:     vp      - vnode of file to be modified.
2688  *              vap     - new attribute values.
2689  *                        If AT_XVATTR set, then optional attrs are being set
2690  *              flags   - ATTR_UTIME set if non-default time values provided.
2691  *                      - ATTR_NOACLCHECK (CIFS context only).
2692  *              cr      - credentials of caller.
2693  *              ct      - caller context
2694  *
2695  *      RETURN: 0 on success, error code on failure.
2696  *
2697  * Timestamps:
2698  *      vp - ctime updated, mtime updated if size changed.
2699  */
2700 /* ARGSUSED */
2701 static int
2702 zfs_setattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
2703     caller_context_t *ct)
2704 {
2705         znode_t         *zp = VTOZ(vp);
2706         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
2707         zilog_t         *zilog;
2708         dmu_tx_t        *tx;
2709         vattr_t         oldva;
2710         xvattr_t        tmpxvattr;
2711         uint_t          mask = vap->va_mask;
2712         uint_t          saved_mask = 0;
2713         int             trim_mask = 0;
2714         uint64_t        new_mode;
2715         uint64_t        new_uid, new_gid;
2716         uint64_t        xattr_obj;
2717         uint64_t        mtime[2], ctime[2];
2718         znode_t         *attrzp;
2719         int             need_policy = FALSE;
2720         int             err, err2;
2721         zfs_fuid_info_t *fuidp = NULL;
2722         xvattr_t *xvap = (xvattr_t *)vap;       /* vap may be an xvattr_t * */
2723         xoptattr_t      *xoap;
2724         zfs_acl_t       *aclp;
2725         boolean_t skipaclchk = (flags & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
2726         boolean_t       fuid_dirtied = B_FALSE;
2727         sa_bulk_attr_t  bulk[7], xattr_bulk[7];
2728         int             count = 0, xattr_count = 0;
2729 
2730         if (mask == 0)
2731                 return (0);
2732 
2733         if (mask & AT_NOSET)
2734                 return (SET_ERROR(EINVAL));
2735 
2736         ZFS_ENTER(zfsvfs);
2737         ZFS_VERIFY_ZP(zp);
2738 
2739         zilog = zfsvfs->z_log;
2740 
2741         /*
2742          * Make sure that if we have ephemeral uid/gid or xvattr specified
2743          * that file system is at proper version level
2744          */
2745 
2746         if (zfsvfs->z_use_fuids == B_FALSE &&
2747             (((mask & AT_UID) && IS_EPHEMERAL(vap->va_uid)) ||
2748             ((mask & AT_GID) && IS_EPHEMERAL(vap->va_gid)) ||
2749             (mask & AT_XVATTR))) {
2750                 ZFS_EXIT(zfsvfs);
2751                 return (SET_ERROR(EINVAL));
2752         }
2753 
2754         if (mask & AT_SIZE && vp->v_type == VDIR) {
2755                 ZFS_EXIT(zfsvfs);
2756                 return (SET_ERROR(EISDIR));
2757         }
2758 
2759         if (mask & AT_SIZE && vp->v_type != VREG && vp->v_type != VFIFO) {
2760                 ZFS_EXIT(zfsvfs);
2761                 return (SET_ERROR(EINVAL));
2762         }
2763 
2764         /*
2765          * If this is an xvattr_t, then get a pointer to the structure of
2766          * optional attributes.  If this is NULL, then we have a vattr_t.
2767          */
2768         xoap = xva_getxoptattr(xvap);
2769 
2770         xva_init(&tmpxvattr);
2771 
2772         /*
2773          * Immutable files can only alter immutable bit and atime
2774          */
2775         if ((zp->z_pflags & ZFS_IMMUTABLE) &&
2776             ((mask & (AT_SIZE|AT_UID|AT_GID|AT_MTIME|AT_MODE)) ||
2777             ((mask & AT_XVATTR) && XVA_ISSET_REQ(xvap, XAT_CREATETIME)))) {
2778                 ZFS_EXIT(zfsvfs);
2779                 return (SET_ERROR(EPERM));
2780         }
2781 
2782         if ((mask & AT_SIZE) && (zp->z_pflags & ZFS_READONLY)) {
2783                 ZFS_EXIT(zfsvfs);
2784                 return (SET_ERROR(EPERM));
2785         }
2786 
2787         /*
2788          * Verify timestamps doesn't overflow 32 bits.
2789          * ZFS can handle large timestamps, but 32bit syscalls can't
2790          * handle times greater than 2039.  This check should be removed
2791          * once large timestamps are fully supported.
2792          */
2793         if (mask & (AT_ATIME | AT_MTIME)) {
2794                 if (((mask & AT_ATIME) && TIMESPEC_OVERFLOW(&vap->va_atime)) ||
2795                     ((mask & AT_MTIME) && TIMESPEC_OVERFLOW(&vap->va_mtime))) {
2796                         ZFS_EXIT(zfsvfs);
2797                         return (SET_ERROR(EOVERFLOW));
2798                 }
2799         }
2800 
2801 top:
2802         attrzp = NULL;
2803         aclp = NULL;
2804 
2805         /* Can this be moved to before the top label? */
2806         if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
2807                 ZFS_EXIT(zfsvfs);
2808                 return (SET_ERROR(EROFS));
2809         }
2810 
2811         /*
2812          * First validate permissions
2813          */
2814 
2815         if (mask & AT_SIZE) {
2816                 err = zfs_zaccess(zp, ACE_WRITE_DATA, 0, skipaclchk, cr);
2817                 if (err) {
2818                         ZFS_EXIT(zfsvfs);
2819                         return (err);
2820                 }
2821                 /*
2822                  * XXX - Note, we are not providing any open
2823                  * mode flags here (like FNDELAY), so we may
2824                  * block if there are locks present... this
2825                  * should be addressed in openat().
2826                  */
2827                 /* XXX - would it be OK to generate a log record here? */
2828                 err = zfs_freesp(zp, vap->va_size, 0, 0, FALSE);
2829                 if (err) {
2830                         ZFS_EXIT(zfsvfs);
2831                         return (err);
2832                 }
2833 
2834                 if (vap->va_size == 0)
2835                         vnevent_truncate(ZTOV(zp), ct);
2836         }
2837 
2838         if (mask & (AT_ATIME|AT_MTIME) ||
2839             ((mask & AT_XVATTR) && (XVA_ISSET_REQ(xvap, XAT_HIDDEN) ||
2840             XVA_ISSET_REQ(xvap, XAT_READONLY) ||
2841             XVA_ISSET_REQ(xvap, XAT_ARCHIVE) ||
2842             XVA_ISSET_REQ(xvap, XAT_OFFLINE) ||
2843             XVA_ISSET_REQ(xvap, XAT_SPARSE) ||
2844             XVA_ISSET_REQ(xvap, XAT_CREATETIME) ||
2845             XVA_ISSET_REQ(xvap, XAT_SYSTEM)))) {
2846                 need_policy = zfs_zaccess(zp, ACE_WRITE_ATTRIBUTES, 0,
2847                     skipaclchk, cr);
2848         }
2849 
2850         if (mask & (AT_UID|AT_GID)) {
2851                 int     idmask = (mask & (AT_UID|AT_GID));
2852                 int     take_owner;
2853                 int     take_group;
2854 
2855                 /*
2856                  * NOTE: even if a new mode is being set,
2857                  * we may clear S_ISUID/S_ISGID bits.
2858                  */
2859 
2860                 if (!(mask & AT_MODE))
2861                         vap->va_mode = zp->z_mode;
2862 
2863                 /*
2864                  * Take ownership or chgrp to group we are a member of
2865                  */
2866 
2867                 take_owner = (mask & AT_UID) && (vap->va_uid == crgetuid(cr));
2868                 take_group = (mask & AT_GID) &&
2869                     zfs_groupmember(zfsvfs, vap->va_gid, cr);
2870 
2871                 /*
2872                  * If both AT_UID and AT_GID are set then take_owner and
2873                  * take_group must both be set in order to allow taking
2874                  * ownership.
2875                  *
2876                  * Otherwise, send the check through secpolicy_vnode_setattr()
2877                  *
2878                  */
2879 
2880                 if (((idmask == (AT_UID|AT_GID)) && take_owner && take_group) ||
2881                     ((idmask == AT_UID) && take_owner) ||
2882                     ((idmask == AT_GID) && take_group)) {
2883                         if (zfs_zaccess(zp, ACE_WRITE_OWNER, 0,
2884                             skipaclchk, cr) == 0) {
2885                                 /*
2886                                  * Remove setuid/setgid for non-privileged users
2887                                  */
2888                                 secpolicy_setid_clear(vap, cr);
2889                                 trim_mask = (mask & (AT_UID|AT_GID));
2890                         } else {
2891                                 need_policy =  TRUE;
2892                         }
2893                 } else {
2894                         need_policy =  TRUE;
2895                 }
2896         }
2897 
2898         mutex_enter(&zp->z_lock);
2899         oldva.va_mode = zp->z_mode;
2900         zfs_fuid_map_ids(zp, cr, &oldva.va_uid, &oldva.va_gid);
2901         if (mask & AT_XVATTR) {
2902                 /*
2903                  * Update xvattr mask to include only those attributes
2904                  * that are actually changing.
2905                  *
2906                  * the bits will be restored prior to actually setting
2907                  * the attributes so the caller thinks they were set.
2908                  */
2909                 if (XVA_ISSET_REQ(xvap, XAT_APPENDONLY)) {
2910                         if (xoap->xoa_appendonly !=
2911                             ((zp->z_pflags & ZFS_APPENDONLY) != 0)) {
2912                                 need_policy = TRUE;
2913                         } else {
2914                                 XVA_CLR_REQ(xvap, XAT_APPENDONLY);
2915                                 XVA_SET_REQ(&tmpxvattr, XAT_APPENDONLY);
2916                         }
2917                 }
2918 
2919                 if (XVA_ISSET_REQ(xvap, XAT_NOUNLINK)) {
2920                         if (xoap->xoa_nounlink !=
2921                             ((zp->z_pflags & ZFS_NOUNLINK) != 0)) {
2922                                 need_policy = TRUE;
2923                         } else {
2924                                 XVA_CLR_REQ(xvap, XAT_NOUNLINK);
2925                                 XVA_SET_REQ(&tmpxvattr, XAT_NOUNLINK);
2926                         }
2927                 }
2928 
2929                 if (XVA_ISSET_REQ(xvap, XAT_IMMUTABLE)) {
2930                         if (xoap->xoa_immutable !=
2931                             ((zp->z_pflags & ZFS_IMMUTABLE) != 0)) {
2932                                 need_policy = TRUE;
2933                         } else {
2934                                 XVA_CLR_REQ(xvap, XAT_IMMUTABLE);
2935                                 XVA_SET_REQ(&tmpxvattr, XAT_IMMUTABLE);
2936                         }
2937                 }
2938 
2939                 if (XVA_ISSET_REQ(xvap, XAT_NODUMP)) {
2940                         if (xoap->xoa_nodump !=
2941                             ((zp->z_pflags & ZFS_NODUMP) != 0)) {
2942                                 need_policy = TRUE;
2943                         } else {
2944                                 XVA_CLR_REQ(xvap, XAT_NODUMP);
2945                                 XVA_SET_REQ(&tmpxvattr, XAT_NODUMP);
2946                         }
2947                 }
2948 
2949                 if (XVA_ISSET_REQ(xvap, XAT_AV_MODIFIED)) {
2950                         if (xoap->xoa_av_modified !=
2951                             ((zp->z_pflags & ZFS_AV_MODIFIED) != 0)) {
2952                                 need_policy = TRUE;
2953                         } else {
2954                                 XVA_CLR_REQ(xvap, XAT_AV_MODIFIED);
2955                                 XVA_SET_REQ(&tmpxvattr, XAT_AV_MODIFIED);
2956                         }
2957                 }
2958 
2959                 if (XVA_ISSET_REQ(xvap, XAT_AV_QUARANTINED)) {
2960                         if ((vp->v_type != VREG &&
2961                             xoap->xoa_av_quarantined) ||
2962                             xoap->xoa_av_quarantined !=
2963                             ((zp->z_pflags & ZFS_AV_QUARANTINED) != 0)) {
2964                                 need_policy = TRUE;
2965                         } else {
2966                                 XVA_CLR_REQ(xvap, XAT_AV_QUARANTINED);
2967                                 XVA_SET_REQ(&tmpxvattr, XAT_AV_QUARANTINED);
2968                         }
2969                 }
2970 
2971                 if (XVA_ISSET_REQ(xvap, XAT_REPARSE)) {
2972                         mutex_exit(&zp->z_lock);
2973                         ZFS_EXIT(zfsvfs);
2974                         return (SET_ERROR(EPERM));
2975                 }
2976 
2977                 if (need_policy == FALSE &&
2978                     (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP) ||
2979                     XVA_ISSET_REQ(xvap, XAT_OPAQUE))) {
2980                         need_policy = TRUE;
2981                 }
2982         }
2983 
2984         mutex_exit(&zp->z_lock);
2985 
2986         if (mask & AT_MODE) {
2987                 if (zfs_zaccess(zp, ACE_WRITE_ACL, 0, skipaclchk, cr) == 0) {
2988                         err = secpolicy_setid_setsticky_clear(vp, vap,
2989                             &oldva, cr);
2990                         if (err) {
2991                                 ZFS_EXIT(zfsvfs);
2992                                 return (err);
2993                         }
2994                         trim_mask |= AT_MODE;
2995                 } else {
2996                         need_policy = TRUE;
2997                 }
2998         }
2999 
3000         if (need_policy) {
3001                 /*
3002                  * If trim_mask is set then take ownership
3003                  * has been granted or write_acl is present and user
3004                  * has the ability to modify mode.  In that case remove
3005                  * UID|GID and or MODE from mask so that
3006                  * secpolicy_vnode_setattr() doesn't revoke it.
3007                  */
3008 
3009                 if (trim_mask) {
3010                         saved_mask = vap->va_mask;
3011                         vap->va_mask &= ~trim_mask;
3012                 }
3013                 err = secpolicy_vnode_setattr(cr, vp, vap, &oldva, flags,
3014                     (int (*)(void *, int, cred_t *))zfs_zaccess_unix, zp);
3015                 if (err) {
3016                         ZFS_EXIT(zfsvfs);
3017                         return (err);
3018                 }
3019 
3020                 if (trim_mask)
3021                         vap->va_mask |= saved_mask;
3022         }
3023 
3024         /*
3025          * secpolicy_vnode_setattr, or take ownership may have
3026          * changed va_mask
3027          */
3028         mask = vap->va_mask;
3029 
3030         if ((mask & (AT_UID | AT_GID))) {
3031                 err = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
3032                     &xattr_obj, sizeof (xattr_obj));
3033 
3034                 if (err == 0 && xattr_obj) {
3035                         err = zfs_zget(zp->z_zfsvfs, xattr_obj, &attrzp);
3036                         if (err)
3037                                 goto out2;
3038                 }
3039                 if (mask & AT_UID) {
3040                         new_uid = zfs_fuid_create(zfsvfs,
3041                             (uint64_t)vap->va_uid, cr, ZFS_OWNER, &fuidp);
3042                         if (new_uid != zp->z_uid &&
3043                             zfs_fuid_overquota(zfsvfs, B_FALSE, new_uid)) {
3044                                 if (attrzp)
3045                                         VN_RELE(ZTOV(attrzp));
3046                                 err = SET_ERROR(EDQUOT);
3047                                 goto out2;
3048                         }
3049                 }
3050 
3051                 if (mask & AT_GID) {
3052                         new_gid = zfs_fuid_create(zfsvfs, (uint64_t)vap->va_gid,
3053                             cr, ZFS_GROUP, &fuidp);
3054                         if (new_gid != zp->z_gid &&
3055                             zfs_fuid_overquota(zfsvfs, B_TRUE, new_gid)) {
3056                                 if (attrzp)
3057                                         VN_RELE(ZTOV(attrzp));
3058                                 err = SET_ERROR(EDQUOT);
3059                                 goto out2;
3060                         }
3061                 }
3062         }
3063         tx = dmu_tx_create(zfsvfs->z_os);
3064 
3065         if (mask & AT_MODE) {
3066                 uint64_t pmode = zp->z_mode;
3067                 uint64_t acl_obj;
3068                 new_mode = (pmode & S_IFMT) | (vap->va_mode & ~S_IFMT);
3069 
3070                 if (zp->z_zfsvfs->z_acl_mode == ZFS_ACL_RESTRICTED &&
3071                     !(zp->z_pflags & ZFS_ACL_TRIVIAL)) {
3072                         err = SET_ERROR(EPERM);
3073                         goto out;
3074                 }
3075 
3076                 if (err = zfs_acl_chmod_setattr(zp, &aclp, new_mode))
3077                         goto out;
3078 
3079                 mutex_enter(&zp->z_lock);
3080                 if (!zp->z_is_sa && ((acl_obj = zfs_external_acl(zp)) != 0)) {
3081                         /*
3082                          * Are we upgrading ACL from old V0 format
3083                          * to V1 format?
3084                          */
3085                         if (zfsvfs->z_version >= ZPL_VERSION_FUID &&
3086                             zfs_znode_acl_version(zp) ==
3087                             ZFS_ACL_VERSION_INITIAL) {
3088                                 dmu_tx_hold_free(tx, acl_obj, 0,
3089                                     DMU_OBJECT_END);
3090                                 dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
3091                                     0, aclp->z_acl_bytes);
3092                         } else {
3093                                 dmu_tx_hold_write(tx, acl_obj, 0,
3094                                     aclp->z_acl_bytes);
3095                         }
3096                 } else if (!zp->z_is_sa && aclp->z_acl_bytes > ZFS_ACE_SPACE) {
3097                         dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
3098                             0, aclp->z_acl_bytes);
3099                 }
3100                 mutex_exit(&zp->z_lock);
3101                 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
3102         } else {
3103                 if ((mask & AT_XVATTR) &&
3104                     XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP))
3105                         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
3106                 else
3107                         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
3108         }
3109 
3110         if (attrzp) {
3111                 dmu_tx_hold_sa(tx, attrzp->z_sa_hdl, B_FALSE);
3112         }
3113 
3114         fuid_dirtied = zfsvfs->z_fuid_dirty;
3115         if (fuid_dirtied)
3116                 zfs_fuid_txhold(zfsvfs, tx);
3117 
3118         zfs_sa_upgrade_txholds(tx, zp);
3119 
3120         err = dmu_tx_assign(tx, TXG_WAIT);
3121         if (err)
3122                 goto out;
3123 
3124         count = 0;
3125         /*
3126          * Set each attribute requested.
3127          * We group settings according to the locks they need to acquire.
3128          *
3129          * Note: you cannot set ctime directly, although it will be
3130          * updated as a side-effect of calling this function.
3131          */
3132 
3133 
3134         if (mask & (AT_UID|AT_GID|AT_MODE))
3135                 mutex_enter(&zp->z_acl_lock);
3136         mutex_enter(&zp->z_lock);
3137 
3138         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
3139             &zp->z_pflags, sizeof (zp->z_pflags));
3140 
3141         if (attrzp) {
3142                 if (mask & (AT_UID|AT_GID|AT_MODE))
3143                         mutex_enter(&attrzp->z_acl_lock);
3144                 mutex_enter(&attrzp->z_lock);
3145                 SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
3146                     SA_ZPL_FLAGS(zfsvfs), NULL, &attrzp->z_pflags,
3147                     sizeof (attrzp->z_pflags));
3148         }
3149 
3150         if (mask & (AT_UID|AT_GID)) {
3151 
3152                 if (mask & AT_UID) {
3153                         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_UID(zfsvfs), NULL,
3154                             &new_uid, sizeof (new_uid));
3155                         zp->z_uid = new_uid;
3156                         if (attrzp) {
3157                                 SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
3158                                     SA_ZPL_UID(zfsvfs), NULL, &new_uid,
3159                                     sizeof (new_uid));
3160                                 attrzp->z_uid = new_uid;
3161                         }
3162                 }
3163 
3164                 if (mask & AT_GID) {
3165                         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_GID(zfsvfs),
3166                             NULL, &new_gid, sizeof (new_gid));
3167                         zp->z_gid = new_gid;
3168                         if (attrzp) {
3169                                 SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
3170                                     SA_ZPL_GID(zfsvfs), NULL, &new_gid,
3171                                     sizeof (new_gid));
3172                                 attrzp->z_gid = new_gid;
3173                         }
3174                 }
3175                 if (!(mask & AT_MODE)) {
3176                         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MODE(zfsvfs),
3177                             NULL, &new_mode, sizeof (new_mode));
3178                         new_mode = zp->z_mode;
3179                 }
3180                 err = zfs_acl_chown_setattr(zp);
3181                 ASSERT(err == 0);
3182                 if (attrzp) {
3183                         err = zfs_acl_chown_setattr(attrzp);
3184                         ASSERT(err == 0);
3185                 }
3186         }
3187 
3188         if (mask & AT_MODE) {
3189                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MODE(zfsvfs), NULL,
3190                     &new_mode, sizeof (new_mode));
3191                 zp->z_mode = new_mode;
3192                 ASSERT3U((uintptr_t)aclp, !=, NULL);
3193                 err = zfs_aclset_common(zp, aclp, cr, tx);
3194                 ASSERT0(err);
3195                 if (zp->z_acl_cached)
3196                         zfs_acl_free(zp->z_acl_cached);
3197                 zp->z_acl_cached = aclp;
3198                 aclp = NULL;
3199         }
3200 
3201 
3202         if (mask & AT_ATIME) {
3203                 ZFS_TIME_ENCODE(&vap->va_atime, zp->z_atime);
3204                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_ATIME(zfsvfs), NULL,
3205                     &zp->z_atime, sizeof (zp->z_atime));
3206         }
3207 
3208         if (mask & AT_MTIME) {
3209                 ZFS_TIME_ENCODE(&vap->va_mtime, mtime);
3210                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
3211                     mtime, sizeof (mtime));
3212         }
3213 
3214         /* XXX - shouldn't this be done *before* the ATIME/MTIME checks? */
3215         if (mask & AT_SIZE && !(mask & AT_MTIME)) {
3216                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs),
3217                     NULL, mtime, sizeof (mtime));
3218                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
3219                     &ctime, sizeof (ctime));
3220                 zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime,
3221                     B_TRUE);
3222         } else if (mask != 0) {
3223                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
3224                     &ctime, sizeof (ctime));
3225                 zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime, ctime,
3226                     B_TRUE);
3227                 if (attrzp) {
3228                         SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
3229                             SA_ZPL_CTIME(zfsvfs), NULL,
3230                             &ctime, sizeof (ctime));
3231                         zfs_tstamp_update_setup(attrzp, STATE_CHANGED,
3232                             mtime, ctime, B_TRUE);
3233                 }
3234         }
3235         /*
3236          * Do this after setting timestamps to prevent timestamp
3237          * update from toggling bit
3238          */
3239 
3240         if (xoap && (mask & AT_XVATTR)) {
3241 
3242                 /*
3243                  * restore trimmed off masks
3244                  * so that return masks can be set for caller.
3245                  */
3246 
3247                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_APPENDONLY)) {
3248                         XVA_SET_REQ(xvap, XAT_APPENDONLY);
3249                 }
3250                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_NOUNLINK)) {
3251                         XVA_SET_REQ(xvap, XAT_NOUNLINK);
3252                 }
3253                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_IMMUTABLE)) {
3254                         XVA_SET_REQ(xvap, XAT_IMMUTABLE);
3255                 }
3256                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_NODUMP)) {
3257                         XVA_SET_REQ(xvap, XAT_NODUMP);
3258                 }
3259                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_AV_MODIFIED)) {
3260                         XVA_SET_REQ(xvap, XAT_AV_MODIFIED);
3261                 }
3262                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_AV_QUARANTINED)) {
3263                         XVA_SET_REQ(xvap, XAT_AV_QUARANTINED);
3264                 }
3265 
3266                 if (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP))
3267                         ASSERT(vp->v_type == VREG);
3268 
3269                 zfs_xvattr_set(zp, xvap, tx);
3270         }
3271 
3272         if (fuid_dirtied)
3273                 zfs_fuid_sync(zfsvfs, tx);
3274 
3275         if (mask != 0)
3276                 zfs_log_setattr(zilog, tx, TX_SETATTR, zp, vap, mask, fuidp);
3277 
3278         mutex_exit(&zp->z_lock);
3279         if (mask & (AT_UID|AT_GID|AT_MODE))
3280                 mutex_exit(&zp->z_acl_lock);
3281 
3282         if (attrzp) {
3283                 if (mask & (AT_UID|AT_GID|AT_MODE))
3284                         mutex_exit(&attrzp->z_acl_lock);
3285                 mutex_exit(&attrzp->z_lock);
3286         }
3287 out:
3288         if (err == 0 && attrzp) {
3289                 err2 = sa_bulk_update(attrzp->z_sa_hdl, xattr_bulk,
3290                     xattr_count, tx);
3291                 ASSERT(err2 == 0);
3292         }
3293 
3294         if (attrzp)
3295                 VN_RELE(ZTOV(attrzp));
3296 
3297         if (aclp)
3298                 zfs_acl_free(aclp);
3299 
3300         if (fuidp) {
3301                 zfs_fuid_info_free(fuidp);
3302                 fuidp = NULL;
3303         }
3304 
3305         if (err) {
3306                 dmu_tx_abort(tx);
3307                 if (err == ERESTART)
3308                         goto top;
3309         } else {
3310                 err2 = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
3311                 dmu_tx_commit(tx);
3312         }
3313 
3314 out2:
3315         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
3316                 zil_commit(zilog, 0);
3317 
3318         ZFS_EXIT(zfsvfs);
3319         return (err);
3320 }
3321 
3322 typedef struct zfs_zlock {
3323         krwlock_t       *zl_rwlock;     /* lock we acquired */
3324         znode_t         *zl_znode;      /* znode we held */
3325         struct zfs_zlock *zl_next;      /* next in list */
3326 } zfs_zlock_t;
3327 
3328 /*
3329  * Drop locks and release vnodes that were held by zfs_rename_lock().
3330  */
3331 static void
3332 zfs_rename_unlock(zfs_zlock_t **zlpp)
3333 {
3334         zfs_zlock_t *zl;
3335 
3336         while ((zl = *zlpp) != NULL) {
3337                 if (zl->zl_znode != NULL)
3338                         VN_RELE(ZTOV(zl->zl_znode));
3339                 rw_exit(zl->zl_rwlock);
3340                 *zlpp = zl->zl_next;
3341                 kmem_free(zl, sizeof (*zl));
3342         }
3343 }
3344 
3345 /*
3346  * Search back through the directory tree, using the ".." entries.
3347  * Lock each directory in the chain to prevent concurrent renames.
3348  * Fail any attempt to move a directory into one of its own descendants.
3349  * XXX - z_parent_lock can overlap with map or grow locks
3350  */
3351 static int
3352 zfs_rename_lock(znode_t *szp, znode_t *tdzp, znode_t *sdzp, zfs_zlock_t **zlpp)
3353 {
3354         zfs_zlock_t     *zl;
3355         znode_t         *zp = tdzp;
3356         uint64_t        rootid = zp->z_zfsvfs->z_root;
3357         uint64_t        oidp = zp->z_id;
3358         krwlock_t       *rwlp = &szp->z_parent_lock;
3359         krw_t           rw = RW_WRITER;
3360 
3361         /*
3362          * First pass write-locks szp and compares to zp->z_id.
3363          * Later passes read-lock zp and compare to zp->z_parent.
3364          */
3365         do {
3366                 if (!rw_tryenter(rwlp, rw)) {
3367                         /*
3368                          * Another thread is renaming in this path.
3369                          * Note that if we are a WRITER, we don't have any
3370                          * parent_locks held yet.
3371                          */
3372                         if (rw == RW_READER && zp->z_id > szp->z_id) {
3373                                 /*
3374                                  * Drop our locks and restart
3375                                  */
3376                                 zfs_rename_unlock(&zl);
3377                                 *zlpp = NULL;
3378                                 zp = tdzp;
3379                                 oidp = zp->z_id;
3380                                 rwlp = &szp->z_parent_lock;
3381                                 rw = RW_WRITER;
3382                                 continue;
3383                         } else {
3384                                 /*
3385                                  * Wait for other thread to drop its locks
3386                                  */
3387                                 rw_enter(rwlp, rw);
3388                         }
3389                 }
3390 
3391                 zl = kmem_alloc(sizeof (*zl), KM_SLEEP);
3392                 zl->zl_rwlock = rwlp;
3393                 zl->zl_znode = NULL;
3394                 zl->zl_next = *zlpp;
3395                 *zlpp = zl;
3396 
3397                 if (oidp == szp->z_id)               /* We're a descendant of szp */
3398                         return (SET_ERROR(EINVAL));
3399 
3400                 if (oidp == rootid)             /* We've hit the top */
3401                         return (0);
3402 
3403                 if (rw == RW_READER) {          /* i.e. not the first pass */
3404                         int error = zfs_zget(zp->z_zfsvfs, oidp, &zp);
3405                         if (error)
3406                                 return (error);
3407                         zl->zl_znode = zp;
3408                 }
3409                 (void) sa_lookup(zp->z_sa_hdl, SA_ZPL_PARENT(zp->z_zfsvfs),
3410                     &oidp, sizeof (oidp));
3411                 rwlp = &zp->z_parent_lock;
3412                 rw = RW_READER;
3413 
3414         } while (zp->z_id != sdzp->z_id);
3415 
3416         return (0);
3417 }
3418 
3419 /*
3420  * Move an entry from the provided source directory to the target
3421  * directory.  Change the entry name as indicated.
3422  *
3423  *      IN:     sdvp    - Source directory containing the "old entry".
3424  *              snm     - Old entry name.
3425  *              tdvp    - Target directory to contain the "new entry".
3426  *              tnm     - New entry name.
3427  *              cr      - credentials of caller.
3428  *              ct      - caller context
3429  *              flags   - case flags
3430  *
3431  *      RETURN: 0 on success, error code on failure.
3432  *
3433  * Timestamps:
3434  *      sdvp,tdvp - ctime|mtime updated
3435  */
3436 /*ARGSUSED*/
3437 static int
3438 zfs_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm, cred_t *cr,
3439     caller_context_t *ct, int flags)
3440 {
3441         znode_t         *tdzp, *szp, *tzp;
3442         znode_t         *sdzp = VTOZ(sdvp);
3443         zfsvfs_t        *zfsvfs = sdzp->z_zfsvfs;
3444         zilog_t         *zilog;
3445         vnode_t         *realvp;
3446         zfs_dirlock_t   *sdl, *tdl;
3447         dmu_tx_t        *tx;
3448         zfs_zlock_t     *zl;
3449         int             cmp, serr, terr;
3450         int             error = 0;
3451         int             zflg = 0;
3452         boolean_t       waited = B_FALSE;
3453 
3454         ZFS_ENTER(zfsvfs);
3455         ZFS_VERIFY_ZP(sdzp);
3456         zilog = zfsvfs->z_log;
3457 
3458         /*
3459          * Make sure we have the real vp for the target directory.
3460          */
3461         if (VOP_REALVP(tdvp, &realvp, ct) == 0)
3462                 tdvp = realvp;
3463 
3464         tdzp = VTOZ(tdvp);
3465         ZFS_VERIFY_ZP(tdzp);
3466 
3467         /*
3468          * We check z_zfsvfs rather than v_vfsp here, because snapshots and the
3469          * ctldir appear to have the same v_vfsp.
3470          */
3471         if (tdzp->z_zfsvfs != zfsvfs || zfsctl_is_node(tdvp)) {
3472                 ZFS_EXIT(zfsvfs);
3473                 return (SET_ERROR(EXDEV));
3474         }
3475 
3476         if (zfsvfs->z_utf8 && u8_validate(tnm,
3477             strlen(tnm), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
3478                 ZFS_EXIT(zfsvfs);
3479                 return (SET_ERROR(EILSEQ));
3480         }
3481 
3482         if (flags & FIGNORECASE)
3483                 zflg |= ZCILOOK;
3484 
3485 top:
3486         szp = NULL;
3487         tzp = NULL;
3488         zl = NULL;
3489 
3490         /*
3491          * This is to prevent the creation of links into attribute space
3492          * by renaming a linked file into/outof an attribute directory.
3493          * See the comment in zfs_link() for why this is considered bad.
3494          */
3495         if ((tdzp->z_pflags & ZFS_XATTR) != (sdzp->z_pflags & ZFS_XATTR)) {
3496                 ZFS_EXIT(zfsvfs);
3497                 return (SET_ERROR(EINVAL));
3498         }
3499 
3500         /*
3501          * Lock source and target directory entries.  To prevent deadlock,
3502          * a lock ordering must be defined.  We lock the directory with
3503          * the smallest object id first, or if it's a tie, the one with
3504          * the lexically first name.
3505          */
3506         if (sdzp->z_id < tdzp->z_id) {
3507                 cmp = -1;
3508         } else if (sdzp->z_id > tdzp->z_id) {
3509                 cmp = 1;
3510         } else {
3511                 /*
3512                  * First compare the two name arguments without
3513                  * considering any case folding.
3514                  */
3515                 int nofold = (zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER);
3516 
3517                 cmp = u8_strcmp(snm, tnm, 0, nofold, U8_UNICODE_LATEST, &error);
3518                 ASSERT(error == 0 || !zfsvfs->z_utf8);
3519                 if (cmp == 0) {
3520                         /*
3521                          * POSIX: "If the old argument and the new argument
3522                          * both refer to links to the same existing file,
3523                          * the rename() function shall return successfully
3524                          * and perform no other action."
3525                          */
3526                         ZFS_EXIT(zfsvfs);
3527                         return (0);
3528                 }
3529                 /*
3530                  * If the file system is case-folding, then we may
3531                  * have some more checking to do.  A case-folding file
3532                  * system is either supporting mixed case sensitivity
3533                  * access or is completely case-insensitive.  Note
3534                  * that the file system is always case preserving.
3535                  *
3536                  * In mixed sensitivity mode case sensitive behavior
3537                  * is the default.  FIGNORECASE must be used to
3538                  * explicitly request case insensitive behavior.
3539                  *
3540                  * If the source and target names provided differ only
3541                  * by case (e.g., a request to rename 'tim' to 'Tim'),
3542                  * we will treat this as a special case in the
3543                  * case-insensitive mode: as long as the source name
3544                  * is an exact match, we will allow this to proceed as
3545                  * a name-change request.
3546                  */
3547                 if ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE ||
3548                     (zfsvfs->z_case == ZFS_CASE_MIXED &&
3549                     flags & FIGNORECASE)) &&
3550                     u8_strcmp(snm, tnm, 0, zfsvfs->z_norm, U8_UNICODE_LATEST,
3551                     &error) == 0) {
3552                         /*
3553                          * case preserving rename request, require exact
3554                          * name matches
3555                          */
3556                         zflg |= ZCIEXACT;
3557                         zflg &= ~ZCILOOK;
3558                 }
3559         }
3560 
3561         /*
3562          * If the source and destination directories are the same, we should
3563          * grab the z_name_lock of that directory only once.
3564          */
3565         if (sdzp == tdzp) {
3566                 zflg |= ZHAVELOCK;
3567                 rw_enter(&sdzp->z_name_lock, RW_READER);
3568         }
3569 
3570         if (cmp < 0) {
3571                 serr = zfs_dirent_lock(&sdl, sdzp, snm, &szp,
3572                     ZEXISTS | zflg, NULL, NULL);
3573                 terr = zfs_dirent_lock(&tdl,
3574                     tdzp, tnm, &tzp, ZRENAMING | zflg, NULL, NULL);
3575         } else {
3576                 terr = zfs_dirent_lock(&tdl,
3577                     tdzp, tnm, &tzp, zflg, NULL, NULL);
3578                 serr = zfs_dirent_lock(&sdl,
3579                     sdzp, snm, &szp, ZEXISTS | ZRENAMING | zflg,
3580                     NULL, NULL);
3581         }
3582 
3583         if (serr) {
3584                 /*
3585                  * Source entry invalid or not there.
3586                  */
3587                 if (!terr) {
3588                         zfs_dirent_unlock(tdl);
3589                         if (tzp)
3590                                 VN_RELE(ZTOV(tzp));
3591                 }
3592 
3593                 if (sdzp == tdzp)
3594                         rw_exit(&sdzp->z_name_lock);
3595 
3596                 if (strcmp(snm, "..") == 0)
3597                         serr = SET_ERROR(EINVAL);
3598                 ZFS_EXIT(zfsvfs);
3599                 return (serr);
3600         }
3601         if (terr) {
3602                 zfs_dirent_unlock(sdl);
3603                 VN_RELE(ZTOV(szp));
3604 
3605                 if (sdzp == tdzp)
3606                         rw_exit(&sdzp->z_name_lock);
3607 
3608                 if (strcmp(tnm, "..") == 0)
3609                         terr = SET_ERROR(EINVAL);
3610                 ZFS_EXIT(zfsvfs);
3611                 return (terr);
3612         }
3613 
3614         /*
3615          * Must have write access at the source to remove the old entry
3616          * and write access at the target to create the new entry.
3617          * Note that if target and source are the same, this can be
3618          * done in a single check.
3619          */
3620 
3621         if (error = zfs_zaccess_rename(sdzp, szp, tdzp, tzp, cr))
3622                 goto out;
3623 
3624         if (ZTOV(szp)->v_type == VDIR) {
3625                 /*
3626                  * Check to make sure rename is valid.
3627                  * Can't do a move like this: /usr/a/b to /usr/a/b/c/d
3628                  */
3629                 if (error = zfs_rename_lock(szp, tdzp, sdzp, &zl))
3630                         goto out;
3631         }
3632 
3633         /*
3634          * Does target exist?
3635          */
3636         if (tzp) {
3637                 /*
3638                  * Source and target must be the same type.
3639                  */
3640                 if (ZTOV(szp)->v_type == VDIR) {
3641                         if (ZTOV(tzp)->v_type != VDIR) {
3642                                 error = SET_ERROR(ENOTDIR);
3643                                 goto out;
3644                         }
3645                 } else {
3646                         if (ZTOV(tzp)->v_type == VDIR) {
3647                                 error = SET_ERROR(EISDIR);
3648                                 goto out;
3649                         }
3650                 }
3651                 /*
3652                  * POSIX dictates that when the source and target
3653                  * entries refer to the same file object, rename
3654                  * must do nothing and exit without error.
3655                  */
3656                 if (szp->z_id == tzp->z_id) {
3657                         error = 0;
3658                         goto out;
3659                 }
3660         }
3661 
3662         vnevent_rename_src(ZTOV(szp), sdvp, snm, ct);
3663         if (tzp)
3664                 vnevent_rename_dest(ZTOV(tzp), tdvp, tnm, ct);
3665 
3666         /*
3667          * notify the target directory if it is not the same
3668          * as source directory.
3669          */
3670         if (tdvp != sdvp) {
3671                 vnevent_rename_dest_dir(tdvp, ct);
3672         }
3673 
3674         tx = dmu_tx_create(zfsvfs->z_os);
3675         dmu_tx_hold_sa(tx, szp->z_sa_hdl, B_FALSE);
3676         dmu_tx_hold_sa(tx, sdzp->z_sa_hdl, B_FALSE);
3677         dmu_tx_hold_zap(tx, sdzp->z_id, FALSE, snm);
3678         dmu_tx_hold_zap(tx, tdzp->z_id, TRUE, tnm);
3679         if (sdzp != tdzp) {
3680                 dmu_tx_hold_sa(tx, tdzp->z_sa_hdl, B_FALSE);
3681                 zfs_sa_upgrade_txholds(tx, tdzp);
3682         }
3683         if (tzp) {
3684                 dmu_tx_hold_sa(tx, tzp->z_sa_hdl, B_FALSE);
3685                 zfs_sa_upgrade_txholds(tx, tzp);
3686         }
3687 
3688         zfs_sa_upgrade_txholds(tx, szp);
3689         dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
3690         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
3691         if (error) {
3692                 if (zl != NULL)
3693                         zfs_rename_unlock(&zl);
3694                 zfs_dirent_unlock(sdl);
3695                 zfs_dirent_unlock(tdl);
3696 
3697                 if (sdzp == tdzp)
3698                         rw_exit(&sdzp->z_name_lock);
3699 
3700                 VN_RELE(ZTOV(szp));
3701                 if (tzp)
3702                         VN_RELE(ZTOV(tzp));
3703                 if (error == ERESTART) {
3704                         waited = B_TRUE;
3705                         dmu_tx_wait(tx);
3706                         dmu_tx_abort(tx);
3707                         goto top;
3708                 }
3709                 dmu_tx_abort(tx);
3710                 ZFS_EXIT(zfsvfs);
3711                 return (error);
3712         }
3713 
3714         if (tzp)        /* Attempt to remove the existing target */
3715                 error = zfs_link_destroy(tdl, tzp, tx, zflg, NULL);
3716 
3717         if (error == 0) {
3718                 error = zfs_link_create(tdl, szp, tx, ZRENAMING);
3719                 if (error == 0) {
3720                         szp->z_pflags |= ZFS_AV_MODIFIED;
3721 
3722                         error = sa_update(szp->z_sa_hdl, SA_ZPL_FLAGS(zfsvfs),
3723                             (void *)&szp->z_pflags, sizeof (uint64_t), tx);
3724                         ASSERT0(error);
3725 
3726                         error = zfs_link_destroy(sdl, szp, tx, ZRENAMING, NULL);
3727                         if (error == 0) {
3728                                 zfs_log_rename(zilog, tx, TX_RENAME |
3729                                     (flags & FIGNORECASE ? TX_CI : 0), sdzp,
3730                                     sdl->dl_name, tdzp, tdl->dl_name, szp);
3731 
3732                                 /*
3733                                  * Update path information for the target vnode
3734                                  */
3735                                 vn_renamepath(tdvp, ZTOV(szp), tnm,
3736                                     strlen(tnm));
3737                         } else {
3738                                 /*
3739                                  * At this point, we have successfully created
3740                                  * the target name, but have failed to remove
3741                                  * the source name.  Since the create was done
3742                                  * with the ZRENAMING flag, there are
3743                                  * complications; for one, the link count is
3744                                  * wrong.  The easiest way to deal with this
3745                                  * is to remove the newly created target, and
3746                                  * return the original error.  This must
3747                                  * succeed; fortunately, it is very unlikely to
3748                                  * fail, since we just created it.
3749                                  */
3750                                 VERIFY3U(zfs_link_destroy(tdl, szp, tx,
3751                                     ZRENAMING, NULL), ==, 0);
3752                         }
3753                 }
3754         }
3755 
3756         dmu_tx_commit(tx);
3757 out:
3758         if (zl != NULL)
3759                 zfs_rename_unlock(&zl);
3760 
3761         zfs_dirent_unlock(sdl);
3762         zfs_dirent_unlock(tdl);
3763 
3764         if (sdzp == tdzp)
3765                 rw_exit(&sdzp->z_name_lock);
3766 
3767 
3768         VN_RELE(ZTOV(szp));
3769         if (tzp)
3770                 VN_RELE(ZTOV(tzp));
3771 
3772         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
3773                 zil_commit(zilog, 0);
3774 
3775         ZFS_EXIT(zfsvfs);
3776         return (error);
3777 }
3778 
3779 /*
3780  * Insert the indicated symbolic reference entry into the directory.
3781  *
3782  *      IN:     dvp     - Directory to contain new symbolic link.
3783  *              link    - Name for new symlink entry.
3784  *              vap     - Attributes of new entry.
3785  *              cr      - credentials of caller.
3786  *              ct      - caller context
3787  *              flags   - case flags
3788  *
3789  *      RETURN: 0 on success, error code on failure.
3790  *
3791  * Timestamps:
3792  *      dvp - ctime|mtime updated
3793  */
3794 /*ARGSUSED*/
3795 static int
3796 zfs_symlink(vnode_t *dvp, char *name, vattr_t *vap, char *link, cred_t *cr,
3797     caller_context_t *ct, int flags)
3798 {
3799         znode_t         *zp, *dzp = VTOZ(dvp);
3800         zfs_dirlock_t   *dl;
3801         dmu_tx_t        *tx;
3802         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
3803         zilog_t         *zilog;
3804         uint64_t        len = strlen(link);
3805         int             error;
3806         int             zflg = ZNEW;
3807         zfs_acl_ids_t   acl_ids;
3808         boolean_t       fuid_dirtied;
3809         uint64_t        txtype = TX_SYMLINK;
3810         boolean_t       waited = B_FALSE;
3811 
3812         ASSERT(vap->va_type == VLNK);
3813 
3814         ZFS_ENTER(zfsvfs);
3815         ZFS_VERIFY_ZP(dzp);
3816         zilog = zfsvfs->z_log;
3817 
3818         if (zfsvfs->z_utf8 && u8_validate(name, strlen(name),
3819             NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
3820                 ZFS_EXIT(zfsvfs);
3821                 return (SET_ERROR(EILSEQ));
3822         }
3823         if (flags & FIGNORECASE)
3824                 zflg |= ZCILOOK;
3825 
3826         if (len > MAXPATHLEN) {
3827                 ZFS_EXIT(zfsvfs);
3828                 return (SET_ERROR(ENAMETOOLONG));
3829         }
3830 
3831         if ((error = zfs_acl_ids_create(dzp, 0,
3832             vap, cr, NULL, &acl_ids)) != 0) {
3833                 ZFS_EXIT(zfsvfs);
3834                 return (error);
3835         }
3836 top:
3837         /*
3838          * Attempt to lock directory; fail if entry already exists.
3839          */
3840         error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg, NULL, NULL);
3841         if (error) {
3842                 zfs_acl_ids_free(&acl_ids);
3843                 ZFS_EXIT(zfsvfs);
3844                 return (error);
3845         }
3846 
3847         if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
3848                 zfs_acl_ids_free(&acl_ids);
3849                 zfs_dirent_unlock(dl);
3850                 ZFS_EXIT(zfsvfs);
3851                 return (error);
3852         }
3853 
3854         if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
3855                 zfs_acl_ids_free(&acl_ids);
3856                 zfs_dirent_unlock(dl);
3857                 ZFS_EXIT(zfsvfs);
3858                 return (SET_ERROR(EDQUOT));
3859         }
3860         tx = dmu_tx_create(zfsvfs->z_os);
3861         fuid_dirtied = zfsvfs->z_fuid_dirty;
3862         dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, MAX(1, len));
3863         dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
3864         dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
3865             ZFS_SA_BASE_ATTR_SIZE + len);
3866         dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
3867         if (!zfsvfs->z_use_sa && acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
3868                 dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
3869                     acl_ids.z_aclp->z_acl_bytes);
3870         }
3871         if (fuid_dirtied)
3872                 zfs_fuid_txhold(zfsvfs, tx);
3873         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
3874         if (error) {
3875                 zfs_dirent_unlock(dl);
3876                 if (error == ERESTART) {
3877                         waited = B_TRUE;
3878                         dmu_tx_wait(tx);
3879                         dmu_tx_abort(tx);
3880                         goto top;
3881                 }
3882                 zfs_acl_ids_free(&acl_ids);
3883                 dmu_tx_abort(tx);
3884                 ZFS_EXIT(zfsvfs);
3885                 return (error);
3886         }
3887 
3888         /*
3889          * Create a new object for the symlink.
3890          * for version 4 ZPL datsets the symlink will be an SA attribute
3891          */
3892         zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
3893 
3894         if (fuid_dirtied)
3895                 zfs_fuid_sync(zfsvfs, tx);
3896 
3897         mutex_enter(&zp->z_lock);
3898         if (zp->z_is_sa)
3899                 error = sa_update(zp->z_sa_hdl, SA_ZPL_SYMLINK(zfsvfs),
3900                     link, len, tx);
3901         else
3902                 zfs_sa_symlink(zp, link, len, tx);
3903         mutex_exit(&zp->z_lock);
3904 
3905         zp->z_size = len;
3906         (void) sa_update(zp->z_sa_hdl, SA_ZPL_SIZE(zfsvfs),
3907             &zp->z_size, sizeof (zp->z_size), tx);
3908         /*
3909          * Insert the new object into the directory.
3910          */
3911         (void) zfs_link_create(dl, zp, tx, ZNEW);
3912 
3913         if (flags & FIGNORECASE)
3914                 txtype |= TX_CI;
3915         zfs_log_symlink(zilog, tx, txtype, dzp, zp, name, link);
3916 
3917         zfs_acl_ids_free(&acl_ids);
3918 
3919         dmu_tx_commit(tx);
3920 
3921         zfs_dirent_unlock(dl);
3922 
3923         VN_RELE(ZTOV(zp));
3924 
3925         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
3926                 zil_commit(zilog, 0);
3927 
3928         ZFS_EXIT(zfsvfs);
3929         return (error);
3930 }
3931 
3932 /*
3933  * Return, in the buffer contained in the provided uio structure,
3934  * the symbolic path referred to by vp.
3935  *
3936  *      IN:     vp      - vnode of symbolic link.
3937  *              uio     - structure to contain the link path.
3938  *              cr      - credentials of caller.
3939  *              ct      - caller context
3940  *
3941  *      OUT:    uio     - structure containing the link path.
3942  *
3943  *      RETURN: 0 on success, error code on failure.
3944  *
3945  * Timestamps:
3946  *      vp - atime updated
3947  */
3948 /* ARGSUSED */
3949 static int
3950 zfs_readlink(vnode_t *vp, uio_t *uio, cred_t *cr, caller_context_t *ct)
3951 {
3952         znode_t         *zp = VTOZ(vp);
3953         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
3954         int             error;
3955 
3956         ZFS_ENTER(zfsvfs);
3957         ZFS_VERIFY_ZP(zp);
3958 
3959         mutex_enter(&zp->z_lock);
3960         if (zp->z_is_sa)
3961                 error = sa_lookup_uio(zp->z_sa_hdl,
3962                     SA_ZPL_SYMLINK(zfsvfs), uio);
3963         else
3964                 error = zfs_sa_readlink(zp, uio);
3965         mutex_exit(&zp->z_lock);
3966 
3967         ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
3968 
3969         ZFS_EXIT(zfsvfs);
3970         return (error);
3971 }
3972 
3973 /*
3974  * Insert a new entry into directory tdvp referencing svp.
3975  *
3976  *      IN:     tdvp    - Directory to contain new entry.
3977  *              svp     - vnode of new entry.
3978  *              name    - name of new entry.
3979  *              cr      - credentials of caller.
3980  *              ct      - caller context
3981  *
3982  *      RETURN: 0 on success, error code on failure.
3983  *
3984  * Timestamps:
3985  *      tdvp - ctime|mtime updated
3986  *       svp - ctime updated
3987  */
3988 /* ARGSUSED */
3989 static int
3990 zfs_link(vnode_t *tdvp, vnode_t *svp, char *name, cred_t *cr,
3991     caller_context_t *ct, int flags)
3992 {
3993         znode_t         *dzp = VTOZ(tdvp);
3994         znode_t         *tzp, *szp;
3995         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
3996         zilog_t         *zilog;
3997         zfs_dirlock_t   *dl;
3998         dmu_tx_t        *tx;
3999         vnode_t         *realvp;
4000         int             error;
4001         int             zf = ZNEW;
4002         uint64_t        parent;
4003         uid_t           owner;
4004         boolean_t       waited = B_FALSE;
4005 
4006         ASSERT(tdvp->v_type == VDIR);
4007 
4008         ZFS_ENTER(zfsvfs);
4009         ZFS_VERIFY_ZP(dzp);
4010         zilog = zfsvfs->z_log;
4011 
4012         if (VOP_REALVP(svp, &realvp, ct) == 0)
4013                 svp = realvp;
4014 
4015         /*
4016          * POSIX dictates that we return EPERM here.
4017          * Better choices include ENOTSUP or EISDIR.
4018          */
4019         if (svp->v_type == VDIR) {
4020                 ZFS_EXIT(zfsvfs);
4021                 return (SET_ERROR(EPERM));
4022         }
4023 
4024         szp = VTOZ(svp);
4025         ZFS_VERIFY_ZP(szp);
4026 
4027         /*
4028          * We check z_zfsvfs rather than v_vfsp here, because snapshots and the
4029          * ctldir appear to have the same v_vfsp.
4030          */
4031         if (szp->z_zfsvfs != zfsvfs || zfsctl_is_node(svp)) {
4032                 ZFS_EXIT(zfsvfs);
4033                 return (SET_ERROR(EXDEV));
4034         }
4035 
4036         /* Prevent links to .zfs/shares files */
4037 
4038         if ((error = sa_lookup(szp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
4039             &parent, sizeof (uint64_t))) != 0) {
4040                 ZFS_EXIT(zfsvfs);
4041                 return (error);
4042         }
4043         if (parent == zfsvfs->z_shares_dir) {
4044                 ZFS_EXIT(zfsvfs);
4045                 return (SET_ERROR(EPERM));
4046         }
4047 
4048         if (zfsvfs->z_utf8 && u8_validate(name,
4049             strlen(name), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
4050                 ZFS_EXIT(zfsvfs);
4051                 return (SET_ERROR(EILSEQ));
4052         }
4053         if (flags & FIGNORECASE)
4054                 zf |= ZCILOOK;
4055 
4056         /*
4057          * We do not support links between attributes and non-attributes
4058          * because of the potential security risk of creating links
4059          * into "normal" file space in order to circumvent restrictions
4060          * imposed in attribute space.
4061          */
4062         if ((szp->z_pflags & ZFS_XATTR) != (dzp->z_pflags & ZFS_XATTR)) {
4063                 ZFS_EXIT(zfsvfs);
4064                 return (SET_ERROR(EINVAL));
4065         }
4066 
4067 
4068         owner = zfs_fuid_map_id(zfsvfs, szp->z_uid, cr, ZFS_OWNER);
4069         if (owner != crgetuid(cr) && secpolicy_basic_link(cr) != 0) {
4070                 ZFS_EXIT(zfsvfs);
4071                 return (SET_ERROR(EPERM));
4072         }
4073 
4074         if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
4075                 ZFS_EXIT(zfsvfs);
4076                 return (error);
4077         }
4078 
4079 top:
4080         /*
4081          * Attempt to lock directory; fail if entry already exists.
4082          */
4083         error = zfs_dirent_lock(&dl, dzp, name, &tzp, zf, NULL, NULL);
4084         if (error) {
4085                 ZFS_EXIT(zfsvfs);
4086                 return (error);
4087         }
4088 
4089         tx = dmu_tx_create(zfsvfs->z_os);
4090         dmu_tx_hold_sa(tx, szp->z_sa_hdl, B_FALSE);
4091         dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
4092         zfs_sa_upgrade_txholds(tx, szp);
4093         zfs_sa_upgrade_txholds(tx, dzp);
4094         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
4095         if (error) {
4096                 zfs_dirent_unlock(dl);
4097                 if (error == ERESTART) {
4098                         waited = B_TRUE;
4099                         dmu_tx_wait(tx);
4100                         dmu_tx_abort(tx);
4101                         goto top;
4102                 }
4103                 dmu_tx_abort(tx);
4104                 ZFS_EXIT(zfsvfs);
4105                 return (error);
4106         }
4107 
4108         error = zfs_link_create(dl, szp, tx, 0);
4109 
4110         if (error == 0) {
4111                 uint64_t txtype = TX_LINK;
4112                 if (flags & FIGNORECASE)
4113                         txtype |= TX_CI;
4114                 zfs_log_link(zilog, tx, txtype, dzp, szp, name);
4115         }
4116 
4117         dmu_tx_commit(tx);
4118 
4119         zfs_dirent_unlock(dl);
4120 
4121         if (error == 0) {
4122                 vnevent_link(svp, ct);
4123         }
4124 
4125         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
4126                 zil_commit(zilog, 0);
4127 
4128         ZFS_EXIT(zfsvfs);
4129         return (error);
4130 }
4131 
4132 /*
4133  * zfs_null_putapage() is used when the file system has been force
4134  * unmounted. It just drops the pages.
4135  */
4136 /* ARGSUSED */
4137 static int
4138 zfs_null_putapage(vnode_t *vp, page_t *pp, u_offset_t *offp,
4139                 size_t *lenp, int flags, cred_t *cr)
4140 {
4141         pvn_write_done(pp, B_INVAL|B_FORCE|B_ERROR);
4142         return (0);
4143 }
4144 
4145 /*
4146  * Push a page out to disk, klustering if possible.
4147  *
4148  *      IN:     vp      - file to push page to.
4149  *              pp      - page to push.
4150  *              flags   - additional flags.
4151  *              cr      - credentials of caller.
4152  *
4153  *      OUT:    offp    - start of range pushed.
4154  *              lenp    - len of range pushed.
4155  *
4156  *      RETURN: 0 on success, error code on failure.
4157  *
4158  * NOTE: callers must have locked the page to be pushed.  On
4159  * exit, the page (and all other pages in the kluster) must be
4160  * unlocked.
4161  */
4162 /* ARGSUSED */
4163 static int
4164 zfs_putapage(vnode_t *vp, page_t *pp, u_offset_t *offp,
4165                 size_t *lenp, int flags, cred_t *cr)
4166 {
4167         znode_t         *zp = VTOZ(vp);
4168         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4169         dmu_tx_t        *tx;
4170         u_offset_t      off, koff;
4171         size_t          len, klen;
4172         int             err;
4173 
4174         off = pp->p_offset;
4175         len = PAGESIZE;
4176         /*
4177          * If our blocksize is bigger than the page size, try to kluster
4178          * multiple pages so that we write a full block (thus avoiding
4179          * a read-modify-write).
4180          */
4181         if (off < zp->z_size && zp->z_blksz > PAGESIZE) {
4182                 klen = P2ROUNDUP((ulong_t)zp->z_blksz, PAGESIZE);
4183                 koff = ISP2(klen) ? P2ALIGN(off, (u_offset_t)klen) : 0;
4184                 ASSERT(koff <= zp->z_size);
4185                 if (koff + klen > zp->z_size)
4186                         klen = P2ROUNDUP(zp->z_size - koff, (uint64_t)PAGESIZE);
4187                 pp = pvn_write_kluster(vp, pp, &off, &len, koff, klen, flags);
4188         }
4189         ASSERT3U(btop(len), ==, btopr(len));
4190 
4191         /*
4192          * Can't push pages past end-of-file.
4193          */
4194         if (off >= zp->z_size) {
4195                 /* ignore all pages */
4196                 err = 0;
4197                 goto out;
4198         } else if (off + len > zp->z_size) {
4199                 int npages = btopr(zp->z_size - off);
4200                 page_t *trunc;
4201 
4202                 page_list_break(&pp, &trunc, npages);
4203                 /* ignore pages past end of file */
4204                 if (trunc)
4205                         pvn_write_done(trunc, flags);
4206                 len = zp->z_size - off;
4207         }
4208 
4209         if (zfs_owner_overquota(zfsvfs, zp, B_FALSE) ||
4210             zfs_owner_overquota(zfsvfs, zp, B_TRUE)) {
4211                 err = SET_ERROR(EDQUOT);
4212                 goto out;
4213         }
4214         tx = dmu_tx_create(zfsvfs->z_os);
4215         dmu_tx_hold_write(tx, zp->z_id, off, len);
4216 
4217         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
4218         zfs_sa_upgrade_txholds(tx, zp);
4219         err = dmu_tx_assign(tx, TXG_WAIT);
4220         if (err != 0) {
4221                 dmu_tx_abort(tx);
4222                 goto out;
4223         }
4224 
4225         if (zp->z_blksz <= PAGESIZE) {
4226                 caddr_t va = zfs_map_page(pp, S_READ);
4227                 ASSERT3U(len, <=, PAGESIZE);
4228                 dmu_write(zfsvfs->z_os, zp->z_id, off, len, va, tx);
4229                 zfs_unmap_page(pp, va);
4230         } else {
4231                 err = dmu_write_pages(zfsvfs->z_os, zp->z_id, off, len, pp, tx);
4232         }
4233 
4234         if (err == 0) {
4235                 uint64_t mtime[2], ctime[2];
4236                 sa_bulk_attr_t bulk[3];
4237                 int count = 0;
4238 
4239                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
4240                     &mtime, 16);
4241                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
4242                     &ctime, 16);
4243                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
4244                     &zp->z_pflags, 8);
4245                 zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime,
4246                     B_TRUE);
4247                 zfs_log_write(zfsvfs->z_log, tx, TX_WRITE, zp, off, len, 0);
4248         }
4249         dmu_tx_commit(tx);
4250 
4251 out:
4252         pvn_write_done(pp, (err ? B_ERROR : 0) | flags);
4253         if (offp)
4254                 *offp = off;
4255         if (lenp)
4256                 *lenp = len;
4257 
4258         return (err);
4259 }
4260 
4261 /*
4262  * Copy the portion of the file indicated from pages into the file.
4263  * The pages are stored in a page list attached to the files vnode.
4264  *
4265  *      IN:     vp      - vnode of file to push page data to.
4266  *              off     - position in file to put data.
4267  *              len     - amount of data to write.
4268  *              flags   - flags to control the operation.
4269  *              cr      - credentials of caller.
4270  *              ct      - caller context.
4271  *
4272  *      RETURN: 0 on success, error code on failure.
4273  *
4274  * Timestamps:
4275  *      vp - ctime|mtime updated
4276  */
4277 /*ARGSUSED*/
4278 static int
4279 zfs_putpage(vnode_t *vp, offset_t off, size_t len, int flags, cred_t *cr,
4280     caller_context_t *ct)
4281 {
4282         znode_t         *zp = VTOZ(vp);
4283         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4284         page_t          *pp;
4285         size_t          io_len;
4286         u_offset_t      io_off;
4287         uint_t          blksz;
4288         rl_t            *rl;
4289         int             error = 0;
4290 
4291         ZFS_ENTER(zfsvfs);
4292         ZFS_VERIFY_ZP(zp);
4293 
4294         /*
4295          * There's nothing to do if no data is cached.
4296          */
4297         if (!vn_has_cached_data(vp)) {
4298                 ZFS_EXIT(zfsvfs);
4299                 return (0);
4300         }
4301 
4302         /*
4303          * Align this request to the file block size in case we kluster.
4304          * XXX - this can result in pretty aggresive locking, which can
4305          * impact simultanious read/write access.  One option might be
4306          * to break up long requests (len == 0) into block-by-block
4307          * operations to get narrower locking.
4308          */
4309         blksz = zp->z_blksz;
4310         if (ISP2(blksz))
4311                 io_off = P2ALIGN_TYPED(off, blksz, u_offset_t);
4312         else
4313                 io_off = 0;
4314         if (len > 0 && ISP2(blksz))
4315                 io_len = P2ROUNDUP_TYPED(len + (off - io_off), blksz, size_t);
4316         else
4317                 io_len = 0;
4318 
4319         if (io_len == 0) {
4320                 /*
4321                  * Search the entire vp list for pages >= io_off.
4322                  */
4323                 rl = zfs_range_lock(zp, io_off, UINT64_MAX, RL_WRITER);
4324                 error = pvn_vplist_dirty(vp, io_off, zfs_putapage, flags, cr);
4325                 goto out;
4326         }
4327         rl = zfs_range_lock(zp, io_off, io_len, RL_WRITER);
4328 
4329         if (off > zp->z_size) {
4330                 /* past end of file */
4331                 zfs_range_unlock(rl);
4332                 ZFS_EXIT(zfsvfs);
4333                 return (0);
4334         }
4335 
4336         len = MIN(io_len, P2ROUNDUP(zp->z_size, PAGESIZE) - io_off);
4337 
4338         for (off = io_off; io_off < off + len; io_off += io_len) {
4339                 if ((flags & B_INVAL) || ((flags & B_ASYNC) == 0)) {
4340                         pp = page_lookup(vp, io_off,
4341                             (flags & (B_INVAL | B_FREE)) ? SE_EXCL : SE_SHARED);
4342                 } else {
4343                         pp = page_lookup_nowait(vp, io_off,
4344                             (flags & B_FREE) ? SE_EXCL : SE_SHARED);
4345                 }
4346 
4347                 if (pp != NULL && pvn_getdirty(pp, flags)) {
4348                         int err;
4349 
4350                         /*
4351                          * Found a dirty page to push
4352                          */
4353                         err = zfs_putapage(vp, pp, &io_off, &io_len, flags, cr);
4354                         if (err)
4355                                 error = err;
4356                 } else {
4357                         io_len = PAGESIZE;
4358                 }
4359         }
4360 out:
4361         zfs_range_unlock(rl);
4362         if ((flags & B_ASYNC) == 0 || zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
4363                 zil_commit(zfsvfs->z_log, zp->z_id);
4364         ZFS_EXIT(zfsvfs);
4365         return (error);
4366 }
4367 
4368 /*ARGSUSED*/
4369 void
4370 zfs_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
4371 {
4372         znode_t *zp = VTOZ(vp);
4373         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4374         int error;
4375 
4376         rw_enter(&zfsvfs->z_teardown_inactive_lock, RW_READER);
4377         if (zp->z_sa_hdl == NULL) {
4378                 /*
4379                  * The fs has been unmounted, or we did a
4380                  * suspend/resume and this file no longer exists.
4381                  */
4382                 if (vn_has_cached_data(vp)) {
4383                         (void) pvn_vplist_dirty(vp, 0, zfs_null_putapage,
4384                             B_INVAL, cr);
4385                 }
4386 
4387                 mutex_enter(&zp->z_lock);
4388                 mutex_enter(&vp->v_lock);
4389                 ASSERT(vp->v_count == 1);
4390                 vp->v_count = 0;
4391                 mutex_exit(&vp->v_lock);
4392                 mutex_exit(&zp->z_lock);
4393                 rw_exit(&zfsvfs->z_teardown_inactive_lock);
4394                 zfs_znode_free(zp);
4395                 return;
4396         }
4397 
4398         /*
4399          * Attempt to push any data in the page cache.  If this fails
4400          * we will get kicked out later in zfs_zinactive().
4401          */
4402         if (vn_has_cached_data(vp)) {
4403                 (void) pvn_vplist_dirty(vp, 0, zfs_putapage, B_INVAL|B_ASYNC,
4404                     cr);
4405         }
4406 
4407         if (zp->z_atime_dirty && zp->z_unlinked == 0) {
4408                 dmu_tx_t *tx = dmu_tx_create(zfsvfs->z_os);
4409 
4410                 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
4411                 zfs_sa_upgrade_txholds(tx, zp);
4412                 error = dmu_tx_assign(tx, TXG_WAIT);
4413                 if (error) {
4414                         dmu_tx_abort(tx);
4415                 } else {
4416                         mutex_enter(&zp->z_lock);
4417                         (void) sa_update(zp->z_sa_hdl, SA_ZPL_ATIME(zfsvfs),
4418                             (void *)&zp->z_atime, sizeof (zp->z_atime), tx);
4419                         zp->z_atime_dirty = 0;
4420                         mutex_exit(&zp->z_lock);
4421                         dmu_tx_commit(tx);
4422                 }
4423         }
4424 
4425         zfs_zinactive(zp);
4426         rw_exit(&zfsvfs->z_teardown_inactive_lock);
4427 }
4428 
4429 /*
4430  * Bounds-check the seek operation.
4431  *
4432  *      IN:     vp      - vnode seeking within
4433  *              ooff    - old file offset
4434  *              noffp   - pointer to new file offset
4435  *              ct      - caller context
4436  *
4437  *      RETURN: 0 on success, EINVAL if new offset invalid.
4438  */
4439 /* ARGSUSED */
4440 static int
4441 zfs_seek(vnode_t *vp, offset_t ooff, offset_t *noffp,
4442     caller_context_t *ct)
4443 {
4444         if (vp->v_type == VDIR)
4445                 return (0);
4446         return ((*noffp < 0 || *noffp > MAXOFFSET_T) ? EINVAL : 0);
4447 }
4448 
4449 /*
4450  * Pre-filter the generic locking function to trap attempts to place
4451  * a mandatory lock on a memory mapped file.
4452  */
4453 static int
4454 zfs_frlock(vnode_t *vp, int cmd, flock64_t *bfp, int flag, offset_t offset,
4455     flk_callback_t *flk_cbp, cred_t *cr, caller_context_t *ct)
4456 {
4457         znode_t *zp = VTOZ(vp);
4458         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4459 
4460         ZFS_ENTER(zfsvfs);
4461         ZFS_VERIFY_ZP(zp);
4462 
4463         /*
4464          * We are following the UFS semantics with respect to mapcnt
4465          * here: If we see that the file is mapped already, then we will
4466          * return an error, but we don't worry about races between this
4467          * function and zfs_map().
4468          */
4469         if (zp->z_mapcnt > 0 && MANDMODE(zp->z_mode)) {
4470                 ZFS_EXIT(zfsvfs);
4471                 return (SET_ERROR(EAGAIN));
4472         }
4473         ZFS_EXIT(zfsvfs);
4474         return (fs_frlock(vp, cmd, bfp, flag, offset, flk_cbp, cr, ct));
4475 }
4476 
4477 /*
4478  * If we can't find a page in the cache, we will create a new page
4479  * and fill it with file data.  For efficiency, we may try to fill
4480  * multiple pages at once (klustering) to fill up the supplied page
4481  * list.  Note that the pages to be filled are held with an exclusive
4482  * lock to prevent access by other threads while they are being filled.
4483  */
4484 static int
4485 zfs_fillpage(vnode_t *vp, u_offset_t off, struct seg *seg,
4486     caddr_t addr, page_t *pl[], size_t plsz, enum seg_rw rw)
4487 {
4488         znode_t *zp = VTOZ(vp);
4489         page_t *pp, *cur_pp;
4490         objset_t *os = zp->z_zfsvfs->z_os;
4491         u_offset_t io_off, total;
4492         size_t io_len;
4493         int err;
4494 
4495         if (plsz == PAGESIZE || zp->z_blksz <= PAGESIZE) {
4496                 /*
4497                  * We only have a single page, don't bother klustering
4498                  */
4499                 io_off = off;
4500                 io_len = PAGESIZE;
4501                 pp = page_create_va(vp, io_off, io_len,
4502                     PG_EXCL | PG_WAIT, seg, addr);
4503         } else {
4504                 /*
4505                  * Try to find enough pages to fill the page list
4506                  */
4507                 pp = pvn_read_kluster(vp, off, seg, addr, &io_off,
4508                     &io_len, off, plsz, 0);
4509         }
4510         if (pp == NULL) {
4511                 /*
4512                  * The page already exists, nothing to do here.
4513                  */
4514                 *pl = NULL;
4515                 return (0);
4516         }
4517 
4518         /*
4519          * Fill the pages in the kluster.
4520          */
4521         cur_pp = pp;
4522         for (total = io_off + io_len; io_off < total; io_off += PAGESIZE) {
4523                 caddr_t va;
4524 
4525                 ASSERT3U(io_off, ==, cur_pp->p_offset);
4526                 va = zfs_map_page(cur_pp, S_WRITE);
4527                 err = dmu_read(os, zp->z_id, io_off, PAGESIZE, va,
4528                     DMU_READ_PREFETCH);
4529                 zfs_unmap_page(cur_pp, va);
4530                 if (err) {
4531                         /* On error, toss the entire kluster */
4532                         pvn_read_done(pp, B_ERROR);
4533                         /* convert checksum errors into IO errors */
4534                         if (err == ECKSUM)
4535                                 err = SET_ERROR(EIO);
4536                         return (err);
4537                 }
4538                 cur_pp = cur_pp->p_next;
4539         }
4540 
4541         /*
4542          * Fill in the page list array from the kluster starting
4543          * from the desired offset `off'.
4544          * NOTE: the page list will always be null terminated.
4545          */
4546         pvn_plist_init(pp, pl, plsz, off, io_len, rw);
4547         ASSERT(pl == NULL || (*pl)->p_offset == off);
4548 
4549         return (0);
4550 }
4551 
4552 /*
4553  * Return pointers to the pages for the file region [off, off + len]
4554  * in the pl array.  If plsz is greater than len, this function may
4555  * also return page pointers from after the specified region
4556  * (i.e. the region [off, off + plsz]).  These additional pages are
4557  * only returned if they are already in the cache, or were created as
4558  * part of a klustered read.
4559  *
4560  *      IN:     vp      - vnode of file to get data from.
4561  *              off     - position in file to get data from.
4562  *              len     - amount of data to retrieve.
4563  *              plsz    - length of provided page list.
4564  *              seg     - segment to obtain pages for.
4565  *              addr    - virtual address of fault.
4566  *              rw      - mode of created pages.
4567  *              cr      - credentials of caller.
4568  *              ct      - caller context.
4569  *
4570  *      OUT:    protp   - protection mode of created pages.
4571  *              pl      - list of pages created.
4572  *
4573  *      RETURN: 0 on success, error code on failure.
4574  *
4575  * Timestamps:
4576  *      vp - atime updated
4577  */
4578 /* ARGSUSED */
4579 static int
4580 zfs_getpage(vnode_t *vp, offset_t off, size_t len, uint_t *protp,
4581     page_t *pl[], size_t plsz, struct seg *seg, caddr_t addr,
4582     enum seg_rw rw, cred_t *cr, caller_context_t *ct)
4583 {
4584         znode_t         *zp = VTOZ(vp);
4585         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4586         page_t          **pl0 = pl;
4587         int             err = 0;
4588 
4589         /* we do our own caching, faultahead is unnecessary */
4590         if (pl == NULL)
4591                 return (0);
4592         else if (len > plsz)
4593                 len = plsz;
4594         else
4595                 len = P2ROUNDUP(len, PAGESIZE);
4596         ASSERT(plsz >= len);
4597 
4598         ZFS_ENTER(zfsvfs);
4599         ZFS_VERIFY_ZP(zp);
4600 
4601         if (protp)
4602                 *protp = PROT_ALL;
4603 
4604         /*
4605          * Loop through the requested range [off, off + len) looking
4606          * for pages.  If we don't find a page, we will need to create
4607          * a new page and fill it with data from the file.
4608          */
4609         while (len > 0) {
4610                 if (*pl = page_lookup(vp, off, SE_SHARED))
4611                         *(pl+1) = NULL;
4612                 else if (err = zfs_fillpage(vp, off, seg, addr, pl, plsz, rw))
4613                         goto out;
4614                 while (*pl) {
4615                         ASSERT3U((*pl)->p_offset, ==, off);
4616                         off += PAGESIZE;
4617                         addr += PAGESIZE;
4618                         if (len > 0) {
4619                                 ASSERT3U(len, >=, PAGESIZE);
4620                                 len -= PAGESIZE;
4621                         }
4622                         ASSERT3U(plsz, >=, PAGESIZE);
4623                         plsz -= PAGESIZE;
4624                         pl++;
4625                 }
4626         }
4627 
4628         /*
4629          * Fill out the page array with any pages already in the cache.
4630          */
4631         while (plsz > 0 &&
4632             (*pl++ = page_lookup_nowait(vp, off, SE_SHARED))) {
4633                         off += PAGESIZE;
4634                         plsz -= PAGESIZE;
4635         }
4636 out:
4637         if (err) {
4638                 /*
4639                  * Release any pages we have previously locked.
4640                  */
4641                 while (pl > pl0)
4642                         page_unlock(*--pl);
4643         } else {
4644                 ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
4645         }
4646 
4647         *pl = NULL;
4648 
4649         ZFS_EXIT(zfsvfs);
4650         return (err);
4651 }
4652 
4653 /*
4654  * Request a memory map for a section of a file.  This code interacts
4655  * with common code and the VM system as follows:
4656  *
4657  * - common code calls mmap(), which ends up in smmap_common()
4658  * - this calls VOP_MAP(), which takes you into (say) zfs
4659  * - zfs_map() calls as_map(), passing segvn_create() as the callback
4660  * - segvn_create() creates the new segment and calls VOP_ADDMAP()
4661  * - zfs_addmap() updates z_mapcnt
4662  */
4663 /*ARGSUSED*/
4664 static int
4665 zfs_map(vnode_t *vp, offset_t off, struct as *as, caddr_t *addrp,
4666     size_t len, uchar_t prot, uchar_t maxprot, uint_t flags, cred_t *cr,
4667     caller_context_t *ct)
4668 {
4669         znode_t *zp = VTOZ(vp);
4670         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4671         segvn_crargs_t  vn_a;
4672         int             error;
4673 
4674         ZFS_ENTER(zfsvfs);
4675         ZFS_VERIFY_ZP(zp);
4676 
4677         if ((prot & PROT_WRITE) && (zp->z_pflags &
4678             (ZFS_IMMUTABLE | ZFS_READONLY | ZFS_APPENDONLY))) {
4679                 ZFS_EXIT(zfsvfs);
4680                 return (SET_ERROR(EPERM));
4681         }
4682 
4683         if ((prot & (PROT_READ | PROT_EXEC)) &&
4684             (zp->z_pflags & ZFS_AV_QUARANTINED)) {
4685                 ZFS_EXIT(zfsvfs);
4686                 return (SET_ERROR(EACCES));
4687         }
4688 
4689         if (vp->v_flag & VNOMAP) {
4690                 ZFS_EXIT(zfsvfs);
4691                 return (SET_ERROR(ENOSYS));
4692         }
4693 
4694         if (off < 0 || len > MAXOFFSET_T - off) {
4695                 ZFS_EXIT(zfsvfs);
4696                 return (SET_ERROR(ENXIO));
4697         }
4698 
4699         if (vp->v_type != VREG) {
4700                 ZFS_EXIT(zfsvfs);
4701                 return (SET_ERROR(ENODEV));
4702         }
4703 
4704         /*
4705          * If file is locked, disallow mapping.
4706          */
4707         if (MANDMODE(zp->z_mode) && vn_has_flocks(vp)) {
4708                 ZFS_EXIT(zfsvfs);
4709                 return (SET_ERROR(EAGAIN));
4710         }
4711 
4712         as_rangelock(as);
4713         error = choose_addr(as, addrp, len, off, ADDR_VACALIGN, flags);
4714         if (error != 0) {
4715                 as_rangeunlock(as);
4716                 ZFS_EXIT(zfsvfs);
4717                 return (error);
4718         }
4719 
4720         vn_a.vp = vp;
4721         vn_a.offset = (u_offset_t)off;
4722         vn_a.type = flags & MAP_TYPE;
4723         vn_a.prot = prot;
4724         vn_a.maxprot = maxprot;
4725         vn_a.cred = cr;
4726         vn_a.amp = NULL;
4727         vn_a.flags = flags & ~MAP_TYPE;
4728         vn_a.szc = 0;
4729         vn_a.lgrp_mem_policy_flags = 0;
4730 
4731         error = as_map(as, *addrp, len, segvn_create, &vn_a);
4732 
4733         as_rangeunlock(as);
4734         ZFS_EXIT(zfsvfs);
4735         return (error);
4736 }
4737 
4738 /* ARGSUSED */
4739 static int
4740 zfs_addmap(vnode_t *vp, offset_t off, struct as *as, caddr_t addr,
4741     size_t len, uchar_t prot, uchar_t maxprot, uint_t flags, cred_t *cr,
4742     caller_context_t *ct)
4743 {
4744         uint64_t pages = btopr(len);
4745 
4746         atomic_add_64(&VTOZ(vp)->z_mapcnt, pages);
4747         return (0);
4748 }
4749 
4750 /*
4751  * The reason we push dirty pages as part of zfs_delmap() is so that we get a
4752  * more accurate mtime for the associated file.  Since we don't have a way of
4753  * detecting when the data was actually modified, we have to resort to
4754  * heuristics.  If an explicit msync() is done, then we mark the mtime when the
4755  * last page is pushed.  The problem occurs when the msync() call is omitted,
4756  * which by far the most common case:
4757  *
4758  *      open()
4759  *      mmap()
4760  *      <modify memory>
4761  *      munmap()
4762  *      close()
4763  *      <time lapse>
4764  *      putpage() via fsflush
4765  *
4766  * If we wait until fsflush to come along, we can have a modification time that
4767  * is some arbitrary point in the future.  In order to prevent this in the
4768  * common case, we flush pages whenever a (MAP_SHARED, PROT_WRITE) mapping is
4769  * torn down.
4770  */
4771 /* ARGSUSED */
4772 static int
4773 zfs_delmap(vnode_t *vp, offset_t off, struct as *as, caddr_t addr,
4774     size_t len, uint_t prot, uint_t maxprot, uint_t flags, cred_t *cr,
4775     caller_context_t *ct)
4776 {
4777         uint64_t pages = btopr(len);
4778 
4779         ASSERT3U(VTOZ(vp)->z_mapcnt, >=, pages);
4780         atomic_add_64(&VTOZ(vp)->z_mapcnt, -pages);
4781 
4782         if ((flags & MAP_SHARED) && (prot & PROT_WRITE) &&
4783             vn_has_cached_data(vp))
4784                 (void) VOP_PUTPAGE(vp, off, len, B_ASYNC, cr, ct);
4785 
4786         return (0);
4787 }
4788 
4789 /*
4790  * Free or allocate space in a file.  Currently, this function only
4791  * supports the `F_FREESP' command.  However, this command is somewhat
4792  * misnamed, as its functionality includes the ability to allocate as
4793  * well as free space.
4794  *
4795  *      IN:     vp      - vnode of file to free data in.
4796  *              cmd     - action to take (only F_FREESP supported).
4797  *              bfp     - section of file to free/alloc.
4798  *              flag    - current file open mode flags.
4799  *              offset  - current file offset.
4800  *              cr      - credentials of caller [UNUSED].
4801  *              ct      - caller context.
4802  *
4803  *      RETURN: 0 on success, error code on failure.
4804  *
4805  * Timestamps:
4806  *      vp - ctime|mtime updated
4807  */
4808 /* ARGSUSED */
4809 static int
4810 zfs_space(vnode_t *vp, int cmd, flock64_t *bfp, int flag,
4811     offset_t offset, cred_t *cr, caller_context_t *ct)
4812 {
4813         znode_t         *zp = VTOZ(vp);
4814         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4815         uint64_t        off, len;
4816         int             error;
4817 
4818         ZFS_ENTER(zfsvfs);
4819         ZFS_VERIFY_ZP(zp);
4820 
4821         if (cmd != F_FREESP) {
4822                 ZFS_EXIT(zfsvfs);
4823                 return (SET_ERROR(EINVAL));
4824         }
4825 
4826         /*
4827          * In a case vp->v_vfsp != zp->z_zfsvfs->z_vfs (e.g. snapshots) our
4828          * callers might not be able to detect properly that we are read-only,
4829          * so check it explicitly here.
4830          */
4831         if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
4832                 ZFS_EXIT(zfsvfs);
4833                 return (SET_ERROR(EROFS));
4834         }
4835 
4836         if (error = convoff(vp, bfp, 0, offset)) {
4837                 ZFS_EXIT(zfsvfs);
4838                 return (error);
4839         }
4840 
4841         if (bfp->l_len < 0) {
4842                 ZFS_EXIT(zfsvfs);
4843                 return (SET_ERROR(EINVAL));
4844         }
4845 
4846         off = bfp->l_start;
4847         len = bfp->l_len; /* 0 means from off to end of file */
4848 
4849         error = zfs_freesp(zp, off, len, flag, TRUE);
4850 
4851         if (error == 0 && off == 0 && len == 0)
4852                 vnevent_truncate(ZTOV(zp), ct);
4853 
4854         ZFS_EXIT(zfsvfs);
4855         return (error);
4856 }
4857 
4858 /*ARGSUSED*/
4859 static int
4860 zfs_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct)
4861 {
4862         znode_t         *zp = VTOZ(vp);
4863         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4864         uint32_t        gen;
4865         uint64_t        gen64;
4866         uint64_t        object = zp->z_id;
4867         zfid_short_t    *zfid;
4868         int             size, i, error;
4869 
4870         ZFS_ENTER(zfsvfs);
4871         ZFS_VERIFY_ZP(zp);
4872 
4873         if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_GEN(zfsvfs),
4874             &gen64, sizeof (uint64_t))) != 0) {
4875                 ZFS_EXIT(zfsvfs);
4876                 return (error);
4877         }
4878 
4879         gen = (uint32_t)gen64;
4880 
4881         size = (zfsvfs->z_parent != zfsvfs) ? LONG_FID_LEN : SHORT_FID_LEN;
4882         if (fidp->fid_len < size) {
4883                 fidp->fid_len = size;
4884                 ZFS_EXIT(zfsvfs);
4885                 return (SET_ERROR(ENOSPC));
4886         }
4887 
4888         zfid = (zfid_short_t *)fidp;
4889 
4890         zfid->zf_len = size;
4891 
4892         for (i = 0; i < sizeof (zfid->zf_object); i++)
4893                 zfid->zf_object[i] = (uint8_t)(object >> (8 * i));
4894 
4895         /* Must have a non-zero generation number to distinguish from .zfs */
4896         if (gen == 0)
4897                 gen = 1;
4898         for (i = 0; i < sizeof (zfid->zf_gen); i++)
4899                 zfid->zf_gen[i] = (uint8_t)(gen >> (8 * i));
4900 
4901         if (size == LONG_FID_LEN) {
4902                 uint64_t        objsetid = dmu_objset_id(zfsvfs->z_os);
4903                 zfid_long_t     *zlfid;
4904 
4905                 zlfid = (zfid_long_t *)fidp;
4906 
4907                 for (i = 0; i < sizeof (zlfid->zf_setid); i++)
4908                         zlfid->zf_setid[i] = (uint8_t)(objsetid >> (8 * i));
4909 
4910                 /* XXX - this should be the generation number for the objset */
4911                 for (i = 0; i < sizeof (zlfid->zf_setgen); i++)
4912                         zlfid->zf_setgen[i] = 0;
4913         }
4914 
4915         ZFS_EXIT(zfsvfs);
4916         return (0);
4917 }
4918 
4919 static int
4920 zfs_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr,
4921     caller_context_t *ct)
4922 {
4923         znode_t         *zp, *xzp;
4924         zfsvfs_t        *zfsvfs;
4925         zfs_dirlock_t   *dl;
4926         int             error;
4927 
4928         switch (cmd) {
4929         case _PC_LINK_MAX:
4930                 *valp = ULONG_MAX;
4931                 return (0);
4932 
4933         case _PC_FILESIZEBITS:
4934                 *valp = 64;
4935                 return (0);
4936 
4937         case _PC_XATTR_EXISTS:
4938                 zp = VTOZ(vp);
4939                 zfsvfs = zp->z_zfsvfs;
4940                 ZFS_ENTER(zfsvfs);
4941                 ZFS_VERIFY_ZP(zp);
4942                 *valp = 0;
4943                 error = zfs_dirent_lock(&dl, zp, "", &xzp,
4944                     ZXATTR | ZEXISTS | ZSHARED, NULL, NULL);
4945                 if (error == 0) {
4946                         zfs_dirent_unlock(dl);
4947                         if (!zfs_dirempty(xzp))
4948                                 *valp = 1;
4949                         VN_RELE(ZTOV(xzp));
4950                 } else if (error == ENOENT) {
4951                         /*
4952                          * If there aren't extended attributes, it's the
4953                          * same as having zero of them.
4954                          */
4955                         error = 0;
4956                 }
4957                 ZFS_EXIT(zfsvfs);
4958                 return (error);
4959 
4960         case _PC_SATTR_ENABLED:
4961         case _PC_SATTR_EXISTS:
4962                 *valp = vfs_has_feature(vp->v_vfsp, VFSFT_SYSATTR_VIEWS) &&
4963                     (vp->v_type == VREG || vp->v_type == VDIR);
4964                 return (0);
4965 
4966         case _PC_ACCESS_FILTERING:
4967                 *valp = vfs_has_feature(vp->v_vfsp, VFSFT_ACCESS_FILTER) &&
4968                     vp->v_type == VDIR;
4969                 return (0);
4970 
4971         case _PC_ACL_ENABLED:
4972                 *valp = _ACL_ACE_ENABLED;
4973                 return (0);
4974 
4975         case _PC_MIN_HOLE_SIZE:
4976                 *valp = (ulong_t)SPA_MINBLOCKSIZE;
4977                 return (0);
4978 
4979         case _PC_TIMESTAMP_RESOLUTION:
4980                 /* nanosecond timestamp resolution */
4981                 *valp = 1L;
4982                 return (0);
4983 
4984         default:
4985                 return (fs_pathconf(vp, cmd, valp, cr, ct));
4986         }
4987 }
4988 
4989 /*ARGSUSED*/
4990 static int
4991 zfs_getsecattr(vnode_t *vp, vsecattr_t *vsecp, int flag, cred_t *cr,
4992     caller_context_t *ct)
4993 {
4994         znode_t *zp = VTOZ(vp);
4995         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4996         int error;
4997         boolean_t skipaclchk = (flag & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
4998 
4999         ZFS_ENTER(zfsvfs);
5000         ZFS_VERIFY_ZP(zp);
5001         error = zfs_getacl(zp, vsecp, skipaclchk, cr);
5002         ZFS_EXIT(zfsvfs);
5003 
5004         return (error);
5005 }
5006 
5007 /*ARGSUSED*/
5008 static int
5009 zfs_setsecattr(vnode_t *vp, vsecattr_t *vsecp, int flag, cred_t *cr,
5010     caller_context_t *ct)
5011 {
5012         znode_t *zp = VTOZ(vp);
5013         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
5014         int error;
5015         boolean_t skipaclchk = (flag & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
5016         zilog_t *zilog = zfsvfs->z_log;
5017 
5018         ZFS_ENTER(zfsvfs);
5019         ZFS_VERIFY_ZP(zp);
5020 
5021         error = zfs_setacl(zp, vsecp, skipaclchk, cr);
5022 
5023         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
5024                 zil_commit(zilog, 0);
5025 
5026         ZFS_EXIT(zfsvfs);
5027         return (error);
5028 }
5029 
5030 /*
5031  * The smallest read we may consider to loan out an arcbuf.
5032  * This must be a power of 2.
5033  */
5034 int zcr_blksz_min = (1 << 10);    /* 1K */
5035 /*
5036  * If set to less than the file block size, allow loaning out of an
5037  * arcbuf for a partial block read.  This must be a power of 2.
5038  */
5039 int zcr_blksz_max = (1 << 17);    /* 128K */
5040 
5041 /*ARGSUSED*/
5042 static int
5043 zfs_reqzcbuf(vnode_t *vp, enum uio_rw ioflag, xuio_t *xuio, cred_t *cr,
5044     caller_context_t *ct)
5045 {
5046         znode_t *zp = VTOZ(vp);
5047         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
5048         int max_blksz = zfsvfs->z_max_blksz;
5049         uio_t *uio = &xuio->xu_uio;
5050         ssize_t size = uio->uio_resid;
5051         offset_t offset = uio->uio_loffset;
5052         int blksz;
5053         int fullblk, i;
5054         arc_buf_t *abuf;
5055         ssize_t maxsize;
5056         int preamble, postamble;
5057 
5058         if (xuio->xu_type != UIOTYPE_ZEROCOPY)
5059                 return (SET_ERROR(EINVAL));
5060 
5061         ZFS_ENTER(zfsvfs);
5062         ZFS_VERIFY_ZP(zp);
5063         switch (ioflag) {
5064         case UIO_WRITE:
5065                 /*
5066                  * Loan out an arc_buf for write if write size is bigger than
5067                  * max_blksz, and the file's block size is also max_blksz.
5068                  */
5069                 blksz = max_blksz;
5070                 if (size < blksz || zp->z_blksz != blksz) {
5071                         ZFS_EXIT(zfsvfs);
5072                         return (SET_ERROR(EINVAL));
5073                 }
5074                 /*
5075                  * Caller requests buffers for write before knowing where the
5076                  * write offset might be (e.g. NFS TCP write).
5077                  */
5078                 if (offset == -1) {
5079                         preamble = 0;
5080                 } else {
5081                         preamble = P2PHASE(offset, blksz);
5082                         if (preamble) {
5083                                 preamble = blksz - preamble;
5084                                 size -= preamble;
5085                         }
5086                 }
5087 
5088                 postamble = P2PHASE(size, blksz);
5089                 size -= postamble;
5090 
5091                 fullblk = size / blksz;
5092                 (void) dmu_xuio_init(xuio,
5093                     (preamble != 0) + fullblk + (postamble != 0));
5094                 DTRACE_PROBE3(zfs_reqzcbuf_align, int, preamble,
5095                     int, postamble, int,
5096                     (preamble != 0) + fullblk + (postamble != 0));
5097 
5098                 /*
5099                  * Have to fix iov base/len for partial buffers.  They
5100                  * currently represent full arc_buf's.
5101                  */
5102                 if (preamble) {
5103                         /* data begins in the middle of the arc_buf */
5104                         abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
5105                             blksz);
5106                         ASSERT(abuf);
5107                         (void) dmu_xuio_add(xuio, abuf,
5108                             blksz - preamble, preamble);
5109                 }
5110 
5111                 for (i = 0; i < fullblk; i++) {
5112                         abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
5113                             blksz);
5114                         ASSERT(abuf);
5115                         (void) dmu_xuio_add(xuio, abuf, 0, blksz);
5116                 }
5117 
5118                 if (postamble) {
5119                         /* data ends in the middle of the arc_buf */
5120                         abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
5121                             blksz);
5122                         ASSERT(abuf);
5123                         (void) dmu_xuio_add(xuio, abuf, 0, postamble);
5124                 }
5125                 break;
5126         case UIO_READ:
5127                 /*
5128                  * Loan out an arc_buf for read if the read size is larger than
5129                  * the current file block size.  Block alignment is not
5130                  * considered.  Partial arc_buf will be loaned out for read.
5131                  */
5132                 blksz = zp->z_blksz;
5133                 if (blksz < zcr_blksz_min)
5134                         blksz = zcr_blksz_min;
5135                 if (blksz > zcr_blksz_max)
5136                         blksz = zcr_blksz_max;
5137                 /* avoid potential complexity of dealing with it */
5138                 if (blksz > max_blksz) {
5139                         ZFS_EXIT(zfsvfs);
5140                         return (SET_ERROR(EINVAL));
5141                 }
5142 
5143                 maxsize = zp->z_size - uio->uio_loffset;
5144                 if (size > maxsize)
5145                         size = maxsize;
5146 
5147                 if (size < blksz || vn_has_cached_data(vp)) {
5148                         ZFS_EXIT(zfsvfs);
5149                         return (SET_ERROR(EINVAL));
5150                 }
5151                 break;
5152         default:
5153                 ZFS_EXIT(zfsvfs);
5154                 return (SET_ERROR(EINVAL));
5155         }
5156 
5157         uio->uio_extflg = UIO_XUIO;
5158         XUIO_XUZC_RW(xuio) = ioflag;
5159         ZFS_EXIT(zfsvfs);
5160         return (0);
5161 }
5162 
5163 /*ARGSUSED*/
5164 static int
5165 zfs_retzcbuf(vnode_t *vp, xuio_t *xuio, cred_t *cr, caller_context_t *ct)
5166 {
5167         int i;
5168         arc_buf_t *abuf;
5169         int ioflag = XUIO_XUZC_RW(xuio);
5170 
5171         ASSERT(xuio->xu_type == UIOTYPE_ZEROCOPY);
5172 
5173         i = dmu_xuio_cnt(xuio);
5174         while (i-- > 0) {
5175                 abuf = dmu_xuio_arcbuf(xuio, i);
5176                 /*
5177                  * if abuf == NULL, it must be a write buffer
5178                  * that has been returned in zfs_write().
5179                  */
5180                 if (abuf)
5181                         dmu_return_arcbuf(abuf);
5182                 ASSERT(abuf || ioflag == UIO_WRITE);
5183         }
5184 
5185         dmu_xuio_fini(xuio);
5186         return (0);
5187 }
5188 
5189 /*
5190  * Predeclare these here so that the compiler assumes that
5191  * this is an "old style" function declaration that does
5192  * not include arguments => we won't get type mismatch errors
5193  * in the initializations that follow.
5194  */
5195 static int zfs_inval();
5196 static int zfs_isdir();
5197 
5198 static int
5199 zfs_inval()
5200 {
5201         return (SET_ERROR(EINVAL));
5202 }
5203 
5204 static int
5205 zfs_isdir()
5206 {
5207         return (SET_ERROR(EISDIR));
5208 }
5209 /*
5210  * Directory vnode operations template
5211  */
5212 vnodeops_t *zfs_dvnodeops;
5213 const fs_operation_def_t zfs_dvnodeops_template[] = {
5214         VOPNAME_OPEN,           { .vop_open = zfs_open },
5215         VOPNAME_CLOSE,          { .vop_close = zfs_close },
5216         VOPNAME_READ,           { .error = zfs_isdir },
5217         VOPNAME_WRITE,          { .error = zfs_isdir },
5218         VOPNAME_IOCTL,          { .vop_ioctl = zfs_ioctl },
5219         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5220         VOPNAME_SETATTR,        { .vop_setattr = zfs_setattr },
5221         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5222         VOPNAME_LOOKUP,         { .vop_lookup = zfs_lookup },
5223         VOPNAME_CREATE,         { .vop_create = zfs_create },
5224         VOPNAME_REMOVE,         { .vop_remove = zfs_remove },
5225         VOPNAME_LINK,           { .vop_link = zfs_link },
5226         VOPNAME_RENAME,         { .vop_rename = zfs_rename },
5227         VOPNAME_MKDIR,          { .vop_mkdir = zfs_mkdir },
5228         VOPNAME_RMDIR,          { .vop_rmdir = zfs_rmdir },
5229         VOPNAME_READDIR,        { .vop_readdir = zfs_readdir },
5230         VOPNAME_SYMLINK,        { .vop_symlink = zfs_symlink },
5231         VOPNAME_FSYNC,          { .vop_fsync = zfs_fsync },
5232         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5233         VOPNAME_FID,            { .vop_fid = zfs_fid },
5234         VOPNAME_SEEK,           { .vop_seek = zfs_seek },
5235         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5236         VOPNAME_GETSECATTR,     { .vop_getsecattr = zfs_getsecattr },
5237         VOPNAME_SETSECATTR,     { .vop_setsecattr = zfs_setsecattr },
5238         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5239         NULL,                   NULL
5240 };
5241 
5242 /*
5243  * Regular file vnode operations template
5244  */
5245 vnodeops_t *zfs_fvnodeops;
5246 const fs_operation_def_t zfs_fvnodeops_template[] = {
5247         VOPNAME_OPEN,           { .vop_open = zfs_open },
5248         VOPNAME_CLOSE,          { .vop_close = zfs_close },
5249         VOPNAME_READ,           { .vop_read = zfs_read },
5250         VOPNAME_WRITE,          { .vop_write = zfs_write },
5251         VOPNAME_IOCTL,          { .vop_ioctl = zfs_ioctl },
5252         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5253         VOPNAME_SETATTR,        { .vop_setattr = zfs_setattr },
5254         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5255         VOPNAME_LOOKUP,         { .vop_lookup = zfs_lookup },
5256         VOPNAME_RENAME,         { .vop_rename = zfs_rename },
5257         VOPNAME_FSYNC,          { .vop_fsync = zfs_fsync },
5258         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5259         VOPNAME_FID,            { .vop_fid = zfs_fid },
5260         VOPNAME_SEEK,           { .vop_seek = zfs_seek },
5261         VOPNAME_FRLOCK,         { .vop_frlock = zfs_frlock },
5262         VOPNAME_SPACE,          { .vop_space = zfs_space },
5263         VOPNAME_GETPAGE,        { .vop_getpage = zfs_getpage },
5264         VOPNAME_PUTPAGE,        { .vop_putpage = zfs_putpage },
5265         VOPNAME_MAP,            { .vop_map = zfs_map },
5266         VOPNAME_ADDMAP,         { .vop_addmap = zfs_addmap },
5267         VOPNAME_DELMAP,         { .vop_delmap = zfs_delmap },
5268         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5269         VOPNAME_GETSECATTR,     { .vop_getsecattr = zfs_getsecattr },
5270         VOPNAME_SETSECATTR,     { .vop_setsecattr = zfs_setsecattr },
5271         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5272         VOPNAME_REQZCBUF,       { .vop_reqzcbuf = zfs_reqzcbuf },
5273         VOPNAME_RETZCBUF,       { .vop_retzcbuf = zfs_retzcbuf },
5274         NULL,                   NULL
5275 };
5276 
5277 /*
5278  * Symbolic link vnode operations template
5279  */
5280 vnodeops_t *zfs_symvnodeops;
5281 const fs_operation_def_t zfs_symvnodeops_template[] = {
5282         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5283         VOPNAME_SETATTR,        { .vop_setattr = zfs_setattr },
5284         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5285         VOPNAME_RENAME,         { .vop_rename = zfs_rename },
5286         VOPNAME_READLINK,       { .vop_readlink = zfs_readlink },
5287         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5288         VOPNAME_FID,            { .vop_fid = zfs_fid },
5289         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5290         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5291         NULL,                   NULL
5292 };
5293 
5294 /*
5295  * special share hidden files vnode operations template
5296  */
5297 vnodeops_t *zfs_sharevnodeops;
5298 const fs_operation_def_t zfs_sharevnodeops_template[] = {
5299         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5300         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5301         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5302         VOPNAME_FID,            { .vop_fid = zfs_fid },
5303         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5304         VOPNAME_GETSECATTR,     { .vop_getsecattr = zfs_getsecattr },
5305         VOPNAME_SETSECATTR,     { .vop_setsecattr = zfs_setsecattr },
5306         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5307         NULL,                   NULL
5308 };
5309 
5310 /*
5311  * Extended attribute directory vnode operations template
5312  *
5313  * This template is identical to the directory vnodes
5314  * operation template except for restricted operations:
5315  *      VOP_MKDIR()
5316  *      VOP_SYMLINK()
5317  *
5318  * Note that there are other restrictions embedded in:
5319  *      zfs_create()    - restrict type to VREG
5320  *      zfs_link()      - no links into/out of attribute space
5321  *      zfs_rename()    - no moves into/out of attribute space
5322  */
5323 vnodeops_t *zfs_xdvnodeops;
5324 const fs_operation_def_t zfs_xdvnodeops_template[] = {
5325         VOPNAME_OPEN,           { .vop_open = zfs_open },
5326         VOPNAME_CLOSE,          { .vop_close = zfs_close },
5327         VOPNAME_IOCTL,          { .vop_ioctl = zfs_ioctl },
5328         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5329         VOPNAME_SETATTR,        { .vop_setattr = zfs_setattr },
5330         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5331         VOPNAME_LOOKUP,         { .vop_lookup = zfs_lookup },
5332         VOPNAME_CREATE,         { .vop_create = zfs_create },
5333         VOPNAME_REMOVE,         { .vop_remove = zfs_remove },
5334         VOPNAME_LINK,           { .vop_link = zfs_link },
5335         VOPNAME_RENAME,         { .vop_rename = zfs_rename },
5336         VOPNAME_MKDIR,          { .error = zfs_inval },
5337         VOPNAME_RMDIR,          { .vop_rmdir = zfs_rmdir },
5338         VOPNAME_READDIR,        { .vop_readdir = zfs_readdir },
5339         VOPNAME_SYMLINK,        { .error = zfs_inval },
5340         VOPNAME_FSYNC,          { .vop_fsync = zfs_fsync },
5341         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5342         VOPNAME_FID,            { .vop_fid = zfs_fid },
5343         VOPNAME_SEEK,           { .vop_seek = zfs_seek },
5344         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5345         VOPNAME_GETSECATTR,     { .vop_getsecattr = zfs_getsecattr },
5346         VOPNAME_SETSECATTR,     { .vop_setsecattr = zfs_setsecattr },
5347         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5348         NULL,                   NULL
5349 };
5350 
5351 /*
5352  * Error vnode operations template
5353  */
5354 vnodeops_t *zfs_evnodeops;
5355 const fs_operation_def_t zfs_evnodeops_template[] = {
5356         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5357         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5358         NULL,                   NULL
5359 };