@@ -684,21 +684,10 @@
                 return (0);
 
         if (limit == RLIM64_INFINITY || limit > MAXOFFSET_T)
                 limit = MAXOFFSET_T;
 
-        /*
-         * Pre-fault the pages to ensure slow (eg NFS) pages
-         * don't hold up txg.
-         * Skip this if uio contains loaned arc_buf.
-         */
-        if ((uio->uio_extflg == UIO_XUIO) &&
-            (((xuio_t *)uio)->xu_type == UIOTYPE_ZEROCOPY))
-                xuio = (xuio_t *)uio;
-        else
-                uio_prefaultpages(n, uio);
-
         ZFS_ENTER(zfsvfs);
         ZFS_VERIFY_ZP(zp);
 
         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL, &mtime, 16);
         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, &ctime, 16);

@@ -747,10 +736,21 @@
                 ZFS_EXIT(zfsvfs);
                 return (error);
         }
 
         /*
+         * Pre-fault the pages to ensure slow (eg NFS) pages
+         * don't hold up txg.
+         * Skip this if uio contains loaned arc_buf.
+         */
+        if ((uio->uio_extflg == UIO_XUIO) &&
+            (((xuio_t *)uio)->xu_type == UIOTYPE_ZEROCOPY))
+                xuio = (xuio_t *)uio;
+        else
+                uio_prefaultpages(MIN(n, max_blksz), uio);
+
+        /*
          * If in append mode, set the io offset pointer to eof.
          */
         if (ioflag & FAPPEND) {
                 /*
                  * Obtain an appending range lock to guarantee file append

@@ -990,10 +990,13 @@
 
                 if (prev_error != 0 || error != 0)
                         break;
                 ASSERT(tx_bytes == nbytes);
                 n -= nbytes;
+
+                if (!xuio && n > 0)
+                        uio_prefaultpages(MIN(n, max_blksz), uio);
         }
 
         zfs_range_unlock(rl);
 
         /*

@@ -4256,12 +4259,10 @@
                     &ctime, 16);
                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
                     &zp->z_pflags, 8);
                 zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime,
                     B_TRUE);
-                err = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
-
                 zfs_log_write(zfsvfs->z_log, tx, TX_WRITE, zp, off, len, 0);
         }
         dmu_tx_commit(tx);
 
 out:

@@ -4793,10 +4794,14 @@
         uint64_t pages = btopr(len);
 
         ASSERT3U(VTOZ(vp)->z_mapcnt, >=, pages);
         atomic_add_64(&VTOZ(vp)->z_mapcnt, -pages);
 
+        if ((flags & MAP_SHARED) && (prot & PROT_WRITE) &&
+            vn_has_cached_data(vp))
+                (void) VOP_PUTPAGE(vp, off, len, B_ASYNC, cr, ct);
+
         return (0);
 }
 
 /*
  * Free or allocate space in a file.  Currently, this function only