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5056 ZFS deadlock on db_mtx and dn_holds
Reviewed by: Will Andrews <willa@spectralogic.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
    
      
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          --- old/usr/src/uts/common/fs/zfs/sys/dsl_dataset.h
          +++ new/usr/src/uts/common/fs/zfs/sys/dsl_dataset.h
   1    1  /*
   2    2   * CDDL HEADER START
   3    3   *
   4    4   * The contents of this file are subject to the terms of the
   5    5   * Common Development and Distribution License (the "License").
   6    6   * You may not use this file except in compliance with the License.
   7    7   *
   8    8   * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9    9   * or http://www.opensolaris.org/os/licensing.
  10   10   * See the License for the specific language governing permissions
  11   11   * and limitations under the License.
  12   12   *
  13   13   * When distributing Covered Code, include this CDDL HEADER in each
  14   14   * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15   15   * If applicable, add the following below this CDDL HEADER, with the
  
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  16   16   * fields enclosed by brackets "[]" replaced with your own identifying
  17   17   * information: Portions Copyright [yyyy] [name of copyright owner]
  18   18   *
  19   19   * CDDL HEADER END
  20   20   */
  21   21  /*
  22   22   * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23   23   * Copyright (c) 2013 by Delphix. All rights reserved.
  24   24   * Copyright (c) 2013, Joyent, Inc. All rights reserved.
  25   25   * Copyright (c) 2013 Steven Hartland. All rights reserved.
       26 + * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  26   27   */
  27   28  
  28   29  #ifndef _SYS_DSL_DATASET_H
  29   30  #define _SYS_DSL_DATASET_H
  30   31  
  31   32  #include <sys/dmu.h>
  32   33  #include <sys/spa.h>
  33   34  #include <sys/txg.h>
  34   35  #include <sys/zio.h>
  35   36  #include <sys/bplist.h>
  36   37  #include <sys/dsl_synctask.h>
  37   38  #include <sys/zfs_context.h>
  38   39  #include <sys/dsl_deadlist.h>
  39   40  #include <sys/refcount.h>
  40   41  
  41   42  #ifdef  __cplusplus
  42   43  extern "C" {
  43   44  #endif
  44   45  
  45   46  struct dsl_dataset;
  46   47  struct dsl_dir;
  47   48  struct dsl_pool;
  48   49  
  49   50  #define DS_FLAG_INCONSISTENT    (1ULL<<0)
  50   51  #define DS_IS_INCONSISTENT(ds)  \
  51   52          (dsl_dataset_phys(ds)->ds_flags & DS_FLAG_INCONSISTENT)
  52   53  
  53   54  /*
  54   55   * Do not allow this dataset to be promoted.
  55   56   */
  56   57  #define DS_FLAG_NOPROMOTE       (1ULL<<1)
  57   58  
  58   59  /*
  59   60   * DS_FLAG_UNIQUE_ACCURATE is set if ds_unique_bytes has been correctly
  60   61   * calculated for head datasets (starting with SPA_VERSION_UNIQUE_ACCURATE,
  61   62   * refquota/refreservations).
  62   63   */
  63   64  #define DS_FLAG_UNIQUE_ACCURATE (1ULL<<2)
  64   65  
  65   66  /*
  66   67   * DS_FLAG_DEFER_DESTROY is set after 'zfs destroy -d' has been called
  67   68   * on a dataset. This allows the dataset to be destroyed using 'zfs release'.
  68   69   */
  69   70  #define DS_FLAG_DEFER_DESTROY   (1ULL<<3)
  70   71  #define DS_IS_DEFER_DESTROY(ds) \
  71   72          (dsl_dataset_phys(ds)->ds_flags & DS_FLAG_DEFER_DESTROY)
  72   73  
  73   74  /*
  74   75   * DS_FIELD_* are strings that are used in the "extensified" dataset zap object.
  75   76   * They should be of the format <reverse-dns>:<field>.
  76   77   */
  77   78  
  78   79  /*
  79   80   * This field's value is the object ID of a zap object which contains the
  80   81   * bookmarks of this dataset.  If it is present, then this dataset is counted
  81   82   * in the refcount of the SPA_FEATURES_BOOKMARKS feature.
  82   83   */
  83   84  #define DS_FIELD_BOOKMARK_NAMES "com.delphix:bookmarks"
  84   85  
  85   86  /*
  86   87   * This field is present (with value=0) if this dataset may contain large
  87   88   * blocks (>128KB).  If it is present, then this dataset
  88   89   * is counted in the refcount of the SPA_FEATURE_LARGE_BLOCKS feature.
  89   90   */
  90   91  #define DS_FIELD_LARGE_BLOCKS "org.open-zfs:large_blocks"
  91   92  
  92   93  /*
  93   94   * DS_FLAG_CI_DATASET is set if the dataset contains a file system whose
  94   95   * name lookups should be performed case-insensitively.
  95   96   */
  96   97  #define DS_FLAG_CI_DATASET      (1ULL<<16)
  97   98  
  98   99  #define DS_CREATE_FLAG_NODIRTY  (1ULL<<24)
  99  100  
 100  101  typedef struct dsl_dataset_phys {
 101  102          uint64_t ds_dir_obj;            /* DMU_OT_DSL_DIR */
 102  103          uint64_t ds_prev_snap_obj;      /* DMU_OT_DSL_DATASET */
 103  104          uint64_t ds_prev_snap_txg;
 104  105          uint64_t ds_next_snap_obj;      /* DMU_OT_DSL_DATASET */
 105  106          uint64_t ds_snapnames_zapobj;   /* DMU_OT_DSL_DS_SNAP_MAP 0 for snaps */
 106  107          uint64_t ds_num_children;       /* clone/snap children; ==0 for head */
 107  108          uint64_t ds_creation_time;      /* seconds since 1970 */
 108  109          uint64_t ds_creation_txg;
 109  110          uint64_t ds_deadlist_obj;       /* DMU_OT_DEADLIST */
 110  111          /*
 111  112           * ds_referenced_bytes, ds_compressed_bytes, and ds_uncompressed_bytes
 112  113           * include all blocks referenced by this dataset, including those
 113  114           * shared with any other datasets.
 114  115           */
 115  116          uint64_t ds_referenced_bytes;
 116  117          uint64_t ds_compressed_bytes;
 117  118          uint64_t ds_uncompressed_bytes;
 118  119          uint64_t ds_unique_bytes;       /* only relevant to snapshots */
 119  120          /*
 120  121           * The ds_fsid_guid is a 56-bit ID that can change to avoid
 121  122           * collisions.  The ds_guid is a 64-bit ID that will never
 122  123           * change, so there is a small probability that it will collide.
 123  124           */
 124  125          uint64_t ds_fsid_guid;
  
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 125  126          uint64_t ds_guid;
 126  127          uint64_t ds_flags;              /* DS_FLAG_* */
 127  128          blkptr_t ds_bp;
 128  129          uint64_t ds_next_clones_obj;    /* DMU_OT_DSL_CLONES */
 129  130          uint64_t ds_props_obj;          /* DMU_OT_DSL_PROPS for snaps */
 130  131          uint64_t ds_userrefs_obj;       /* DMU_OT_USERREFS */
 131  132          uint64_t ds_pad[5]; /* pad out to 320 bytes for good measure */
 132  133  } dsl_dataset_phys_t;
 133  134  
 134  135  typedef struct dsl_dataset {
      136 +        dmu_buf_user_t ds_dbu;
      137 +
 135  138          /* Immutable: */
 136  139          struct dsl_dir *ds_dir;
 137  140          dmu_buf_t *ds_dbuf;
 138  141          uint64_t ds_object;
 139  142          uint64_t ds_fsid_guid;
      143 +        boolean_t ds_is_snapshot;
 140  144  
 141  145          /* only used in syncing context, only valid for non-snapshots: */
 142  146          struct dsl_dataset *ds_prev;
 143  147          uint64_t ds_bookmarks;  /* DMU_OTN_ZAP_METADATA */
 144  148          boolean_t ds_large_blocks;
 145  149          boolean_t ds_need_large_blocks;
 146  150  
 147  151          /* has internal locking: */
 148  152          dsl_deadlist_t ds_deadlist;
 149  153          bplist_t ds_pending_deadlist;
 150  154  
 151  155          /* protected by lock on pool's dp_dirty_datasets list */
 152  156          txg_node_t ds_dirty_link;
 153  157          list_node_t ds_synced_link;
 154  158  
 155  159          /*
 156  160           * ds_phys->ds_<accounting> is also protected by ds_lock.
 157  161           * Protected by ds_lock:
 158  162           */
 159  163          kmutex_t ds_lock;
 160  164          objset_t *ds_objset;
 161  165          uint64_t ds_userrefs;
 162  166          void *ds_owner;
 163  167  
 164  168          /*
 165  169           * Long holds prevent the ds from being destroyed; they allow the
 166  170           * ds to remain held even after dropping the dp_config_rwlock.
 167  171           * Owning counts as a long hold.  See the comments above
 168  172           * dsl_pool_hold() for details.
 169  173           */
 170  174          refcount_t ds_longholds;
 171  175  
 172  176          /* no locking; only for making guesses */
 173  177          uint64_t ds_trysnap_txg;
 174  178  
 175  179          /* for objset_open() */
 176  180          kmutex_t ds_opening_lock;
 177  181  
 178  182          uint64_t ds_reserved;   /* cached refreservation */
 179  183          uint64_t ds_quota;      /* cached refquota */
 180  184  
 181  185          kmutex_t ds_sendstream_lock;
 182  186          list_t ds_sendstreams;
 183  187  
 184  188          /* Protected by ds_lock; keep at end of struct for better locality */
 185  189          char ds_snapname[MAXNAMELEN];
 186  190  } dsl_dataset_t;
 187  191  
 188  192  inline dsl_dataset_phys_t *
 189  193  dsl_dataset_phys(dsl_dataset_t *ds)
  
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 190  194  {
 191  195          return (ds->ds_dbuf->db_data);
 192  196  }
 193  197  
 194  198  /*
 195  199   * The max length of a temporary tag prefix is the number of hex digits
 196  200   * required to express UINT64_MAX plus one for the hyphen.
 197  201   */
 198  202  #define MAX_TAG_PREFIX_LEN      17
 199  203  
 200      -inline boolean_t
 201      -dsl_dataset_is_snapshot(dsl_dataset_t *ds)
 202      -{
 203      -        return (dsl_dataset_phys(ds)->ds_num_children != 0);
 204      -}
 205      -
 206  204  #define DS_UNIQUE_IS_ACCURATE(ds)       \
 207  205          ((dsl_dataset_phys(ds)->ds_flags & DS_FLAG_UNIQUE_ACCURATE) != 0)
 208  206  
 209  207  int dsl_dataset_hold(struct dsl_pool *dp, const char *name, void *tag,
 210  208      dsl_dataset_t **dsp);
 211  209  int dsl_dataset_hold_obj(struct dsl_pool *dp, uint64_t dsobj, void *tag,
 212  210      dsl_dataset_t **);
 213  211  void dsl_dataset_rele(dsl_dataset_t *ds, void *tag);
 214  212  int dsl_dataset_own(struct dsl_pool *dp, const char *name,
 215  213      void *tag, dsl_dataset_t **dsp);
 216  214  int dsl_dataset_own_obj(struct dsl_pool *dp, uint64_t dsobj,
 217  215      void *tag, dsl_dataset_t **dsp);
 218  216  void dsl_dataset_disown(dsl_dataset_t *ds, void *tag);
 219  217  void dsl_dataset_name(dsl_dataset_t *ds, char *name);
 220  218  boolean_t dsl_dataset_tryown(dsl_dataset_t *ds, void *tag);
 221  219  uint64_t dsl_dataset_create_sync(dsl_dir_t *pds, const char *lastname,
 222  220      dsl_dataset_t *origin, uint64_t flags, cred_t *, dmu_tx_t *);
 223  221  uint64_t dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
 224  222      uint64_t flags, dmu_tx_t *tx);
 225  223  int dsl_dataset_snapshot(nvlist_t *snaps, nvlist_t *props, nvlist_t *errors);
 226  224  int dsl_dataset_promote(const char *name, char *conflsnap);
 227  225  int dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
 228  226      boolean_t force);
 229  227  int dsl_dataset_rename_snapshot(const char *fsname,
 230  228      const char *oldsnapname, const char *newsnapname, boolean_t recursive);
 231  229  int dsl_dataset_snapshot_tmp(const char *fsname, const char *snapname,
 232  230      minor_t cleanup_minor, const char *htag);
 233  231  
 234  232  blkptr_t *dsl_dataset_get_blkptr(dsl_dataset_t *ds);
 235  233  void dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx);
 236  234  
 237  235  spa_t *dsl_dataset_get_spa(dsl_dataset_t *ds);
 238  236  
 239  237  boolean_t dsl_dataset_modified_since_snap(dsl_dataset_t *ds,
 240  238      dsl_dataset_t *snap);
 241  239  
 242  240  void dsl_dataset_sync(dsl_dataset_t *os, zio_t *zio, dmu_tx_t *tx);
 243  241  
 244  242  void dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp,
 245  243      dmu_tx_t *tx);
 246  244  int dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp,
 247  245      dmu_tx_t *tx, boolean_t async);
 248  246  boolean_t dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp,
 249  247      uint64_t blk_birth);
 250  248  uint64_t dsl_dataset_prev_snap_txg(dsl_dataset_t *ds);
 251  249  
 252  250  void dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx);
 253  251  void dsl_dataset_stats(dsl_dataset_t *os, nvlist_t *nv);
 254  252  void dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat);
 255  253  void dsl_dataset_space(dsl_dataset_t *ds,
 256  254      uint64_t *refdbytesp, uint64_t *availbytesp,
 257  255      uint64_t *usedobjsp, uint64_t *availobjsp);
 258  256  uint64_t dsl_dataset_fsid_guid(dsl_dataset_t *ds);
 259  257  int dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new,
 260  258      uint64_t *usedp, uint64_t *compp, uint64_t *uncompp);
 261  259  int dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap, dsl_dataset_t *last,
 262  260      uint64_t *usedp, uint64_t *compp, uint64_t *uncompp);
 263  261  boolean_t dsl_dataset_is_dirty(dsl_dataset_t *ds);
 264  262  int dsl_dataset_activate_large_blocks(const char *dsname);
 265  263  void dsl_dataset_activate_large_blocks_sync_impl(uint64_t dsobj, dmu_tx_t *tx);
 266  264  
 267  265  int dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf);
 268  266  
 269  267  int dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
 270  268      uint64_t asize, uint64_t inflight, uint64_t *used,
 271  269      uint64_t *ref_rsrv);
 272  270  int dsl_dataset_set_refquota(const char *dsname, zprop_source_t source,
 273  271      uint64_t quota);
 274  272  int dsl_dataset_set_refreservation(const char *dsname, zprop_source_t source,
 275  273      uint64_t reservation);
 276  274  
 277  275  boolean_t dsl_dataset_is_before(dsl_dataset_t *later, dsl_dataset_t *earlier,
 278  276      uint64_t earlier_txg);
 279  277  void dsl_dataset_long_hold(dsl_dataset_t *ds, void *tag);
 280  278  void dsl_dataset_long_rele(dsl_dataset_t *ds, void *tag);
 281  279  boolean_t dsl_dataset_long_held(dsl_dataset_t *ds);
 282  280  
 283  281  int dsl_dataset_clone_swap_check_impl(dsl_dataset_t *clone,
 284  282      dsl_dataset_t *origin_head, boolean_t force, void *owner, dmu_tx_t *tx);
 285  283  void dsl_dataset_clone_swap_sync_impl(dsl_dataset_t *clone,
 286  284      dsl_dataset_t *origin_head, dmu_tx_t *tx);
 287  285  int dsl_dataset_snapshot_check_impl(dsl_dataset_t *ds, const char *snapname,
 288  286      dmu_tx_t *tx, boolean_t recv, uint64_t cnt, cred_t *cr);
 289  287  void dsl_dataset_snapshot_sync_impl(dsl_dataset_t *ds, const char *snapname,
 290  288      dmu_tx_t *tx);
 291  289  
 292  290  void dsl_dataset_remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj,
 293  291      dmu_tx_t *tx);
 294  292  void dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds);
 295  293  int dsl_dataset_get_snapname(dsl_dataset_t *ds);
 296  294  int dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name,
 297  295      uint64_t *value);
 298  296  int dsl_dataset_snap_remove(dsl_dataset_t *ds, const char *name, dmu_tx_t *tx,
 299  297      boolean_t adj_cnt);
 300  298  void dsl_dataset_set_refreservation_sync_impl(dsl_dataset_t *ds,
 301  299      zprop_source_t source, uint64_t value, dmu_tx_t *tx);
 302  300  void dsl_dataset_zapify(dsl_dataset_t *ds, dmu_tx_t *tx);
 303  301  int dsl_dataset_rollback(const char *fsname, void *owner, nvlist_t *result);
 304  302  
 305  303  #ifdef ZFS_DEBUG
 306  304  #define dprintf_ds(ds, fmt, ...) do { \
 307  305          if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
 308  306          char *__ds_name = kmem_alloc(MAXNAMELEN, KM_SLEEP); \
 309  307          dsl_dataset_name(ds, __ds_name); \
 310  308          dprintf("ds=%s " fmt, __ds_name, __VA_ARGS__); \
 311  309          kmem_free(__ds_name, MAXNAMELEN); \
 312  310          } \
 313  311  _NOTE(CONSTCOND) } while (0)
 314  312  #else
 315  313  #define dprintf_ds(dd, fmt, ...)
 316  314  #endif
 317  315  
 318  316  #ifdef  __cplusplus
 319  317  }
 320  318  #endif
 321  319  
 322  320  #endif /* _SYS_DSL_DATASET_H */
  
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