Fix a race condition in zfs_getattr_fast()

zfs_getattr_fast() was missing a lock on the ZFS superblock which could result in zfs_znode_dmu_fini() clearing the zp->z_sa_hdl member while zfs_getattr_fast() was accessing the znode. The result of this would usually be a panic. Signed-off-by: Brian Behlendorf <[email protected]> Fixes openzfs#431
openstorage · Nov 3, 2011 · a7b125e · a7b125e
1 parent c475167
commit a7b125e
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c
@@ -2301,6 +2301,9 @@ zfs_getattr_fast(struct inode *ip, struct kstat *sp)
 	znode_t *zp = ITOZ(ip);
 	zfs_sb_t *zsb = ITOZSB(ip);
 
+	ZFS_ENTER(zsb);
+	ZFS_VERIFY_ZP(zp);
+
 	mutex_enter(&zp->z_lock);
 
 	generic_fillattr(ip, sp);
@@ -2316,6 +2319,8 @@ zfs_getattr_fast(struct inode *ip, struct kstat *sp)
 
 	mutex_exit(&zp->z_lock);
 
+	ZFS_EXIT(zsb);
+
 	return (0);
 }
 EXPORT_SYMBOL(zfs_getattr_fast);