Illumos #3875

[mirror_zfs.git] / module / zfs / zfs_vfsops.c

diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c
index 06a5affa4f8f14b07d4a66c69bbe58d73dceb0e5..9fc6c6fe13033dddd439687f5765865540da4e84 100644 (file)
--- a/module/zfs/zfs_vfsops.c
+++ b/module/zfs/zfs_vfsops.c
@@ -1453,7 +1453,9 @@ EXPORT_SYMBOL(zfs_vget);
  * Block out VFS ops and close zfs_sb_t
  *
  * Note, if successful, then we return with the 'z_teardown_lock' and
- * 'z_teardown_inactive_lock' write held.
+ * 'z_teardown_inactive_lock' write held.  We leave ownership of the underlying
+ * dataset and objset intact so that they can be atomically handed off during
+ * a subsequent rollback or recv operation and the resume thereafter.
  */
 int
 zfs_suspend_fs(zfs_sb_t *zsb)
@@ -1463,8 +1465,6 @@ zfs_suspend_fs(zfs_sb_t *zsb)
        if ((error = zfs_sb_teardown(zsb, B_FALSE)) != 0)
                return (error);
 
-       dmu_objset_disown(zsb->z_os, zsb);
-
        return (0);
 }
 EXPORT_SYMBOL(zfs_suspend_fs);
@@ -1476,66 +1476,69 @@ int
 zfs_resume_fs(zfs_sb_t *zsb, const char *osname)
 {
        int err;
+       znode_t *zp;
+       uint64_t sa_obj = 0;
 
        ASSERT(RRW_WRITE_HELD(&zsb->z_teardown_lock));
        ASSERT(RW_WRITE_HELD(&zsb->z_teardown_inactive_lock));
 
-       err = dmu_objset_own(osname, DMU_OST_ZFS, B_FALSE, zsb, &zsb->z_os);
-       if (err) {
-               zsb->z_os = NULL;
-       } else {
-               znode_t *zp;
-               uint64_t sa_obj = 0;
+       /*
+        * We already own this, so just hold and rele it to update the
+        * objset_t, as the one we had before may have been evicted.
+        */
+       VERIFY0(dmu_objset_hold(osname, zsb, &zsb->z_os));
+       VERIFY3P(zsb->z_os->os_dsl_dataset->ds_owner, ==, zsb);
+       VERIFY(dsl_dataset_long_held(zsb->z_os->os_dsl_dataset));
+       dmu_objset_rele(zsb->z_os, zsb);
 
-               /*
-                * Make sure version hasn't changed
-                */
+       /*
+        * Make sure version hasn't changed
+        */
 
-               err = zfs_get_zplprop(zsb->z_os, ZFS_PROP_VERSION,
-                   &zsb->z_version);
+       err = zfs_get_zplprop(zsb->z_os, ZFS_PROP_VERSION,
+           &zsb->z_version);
 
-               if (err)
-                       goto bail;
+       if (err)
+               goto bail;
 
-               err = zap_lookup(zsb->z_os, MASTER_NODE_OBJ,
-                   ZFS_SA_ATTRS, 8, 1, &sa_obj);
+       err = zap_lookup(zsb->z_os, MASTER_NODE_OBJ,
+           ZFS_SA_ATTRS, 8, 1, &sa_obj);
 
-               if (err && zsb->z_version >= ZPL_VERSION_SA)
-                       goto bail;
+       if (err && zsb->z_version >= ZPL_VERSION_SA)
+               goto bail;
 
-               if ((err = sa_setup(zsb->z_os, sa_obj,
-                   zfs_attr_table,  ZPL_END, &zsb->z_attr_table)) != 0)
-                       goto bail;
+       if ((err = sa_setup(zsb->z_os, sa_obj,
+           zfs_attr_table,  ZPL_END, &zsb->z_attr_table)) != 0)
+               goto bail;
 
-               if (zsb->z_version >= ZPL_VERSION_SA)
-                       sa_register_update_callback(zsb->z_os,
-                           zfs_sa_upgrade);
+       if (zsb->z_version >= ZPL_VERSION_SA)
+               sa_register_update_callback(zsb->z_os,
+                   zfs_sa_upgrade);
 
-               VERIFY(zfs_sb_setup(zsb, B_FALSE) == 0);
+       VERIFY(zfs_sb_setup(zsb, B_FALSE) == 0);
 
-               zfs_set_fuid_feature(zsb);
-               zsb->z_rollback_time = jiffies;
+       zfs_set_fuid_feature(zsb);
+       zsb->z_rollback_time = jiffies;
 
-               /*
-                * Attempt to re-establish all the active inodes with their
-                * dbufs.  If a zfs_rezget() fails, then we unhash the inode
-                * and mark it stale.  This prevents a collision if a new
-                * inode/object is created which must use the same inode
-                * number.  The stale inode will be be released when the
-                * VFS prunes the dentry holding the remaining references
-                * on the stale inode.
-                */
-               mutex_enter(&zsb->z_znodes_lock);
-               for (zp = list_head(&zsb->z_all_znodes); zp;
-                   zp = list_next(&zsb->z_all_znodes, zp)) {
-                       err2 = zfs_rezget(zp);
-                       if (err2) {
-                               remove_inode_hash(ZTOI(zp));
-                               zp->z_is_stale = B_TRUE;
-                       }
+       /*
+        * Attempt to re-establish all the active inodes with their
+        * dbufs.  If a zfs_rezget() fails, then we unhash the inode
+        * and mark it stale.  This prevents a collision if a new
+        * inode/object is created which must use the same inode
+        * number.  The stale inode will be be released when the
+        * VFS prunes the dentry holding the remaining references
+        * on the stale inode.
+        */
+       mutex_enter(&zsb->z_znodes_lock);
+       for (zp = list_head(&zsb->z_all_znodes); zp;
+           zp = list_next(&zsb->z_all_znodes, zp)) {
+               err = zfs_rezget(zp);
+               if (err) {
+                       remove_inode_hash(ZTOI(zp));
+                       zp->z_is_stale = B_TRUE;
                }
-               mutex_exit(&zsb->z_znodes_lock);
        }
+       mutex_exit(&zsb->z_znodes_lock);
 
 bail:
        /* release the VFS ops */
@@ -1544,8 +1547,8 @@ bail:
 
        if (err) {
                /*
-                * Since we couldn't reopen zfs_sb_t or, or
-                * setup the sa framework force unmount this file system.
+                * Since we couldn't setup the sa framework, try to force
+                * unmount this file system.
                 */
                if (zsb->z_os)
                        (void) zfs_umount(zsb->z_sb);