X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Fzfs_znode.c;h=f9ea2a0eb7b55a0aede88071498ee7535188e398;hb=0d3ac5e7356d29fbb7d2880c0a0c457656355ca0;hp=1017414f7b1cc72a7584c639192605683bb0d986;hpb=691f6ac4c2858d64afc2a0dc1bd2b8c041d68502;p=zfs.git

diff --git a/module/zfs/zfs_znode.c b/module/zfs/zfs_znode.c
index 1017414..f9ea2a0 100644
--- a/module/zfs/zfs_znode.c
+++ b/module/zfs/zfs_znode.c
@@ -322,7 +322,8 @@ zfs_inode_set_ops(zfs_sb_t *zsb, struct inode *ip)
  */
 static znode_t *
 zfs_znode_alloc(zfs_sb_t *zsb, dmu_buf_t *db, int blksz,
-    dmu_object_type_t obj_type, uint64_t obj, sa_handle_t *hdl)
+    dmu_object_type_t obj_type, uint64_t obj, sa_handle_t *hdl,
+    struct dentry *dentry)
 {
 	znode_t	*zp;
 	struct inode *ip;
@@ -379,6 +380,9 @@ zfs_znode_alloc(zfs_sb_t *zsb, dmu_buf_t *db, int blksz,
 	if (insert_inode_locked(ip))
 		goto error;
 
+	if (dentry)
+		d_instantiate(dentry, ip);
+
 	mutex_enter(&zsb->z_znodes_lock);
 	list_insert_tail(&zsb->z_all_znodes, zp);
 	membar_producer();
@@ -675,7 +679,8 @@ zfs_mknode(znode_t *dzp, vattr_t *vap, dmu_tx_t *tx, cred_t *cr,
 	VERIFY(sa_replace_all_by_template(sa_hdl, sa_attrs, cnt, tx) == 0);
 
 	if (!(flag & IS_ROOT_NODE)) {
-		*zpp = zfs_znode_alloc(zsb, db, 0, obj_type, obj, sa_hdl);
+		*zpp = zfs_znode_alloc(zsb, db, 0, obj_type, obj, sa_hdl,
+		    vap->va_dentry);
 		ASSERT(*zpp != NULL);
 		ASSERT(dzp != NULL);
 		err = zpl_xattr_security_init(ZTOI(*zpp), ZTOI(dzp));
@@ -866,7 +871,7 @@ zfs_zget(zfs_sb_t *zsb, uint64_t obj_num, znode_t **zpp)
 	 * bonus buffer.
 	 */
 	zp = zfs_znode_alloc(zsb, db, doi.doi_data_block_size,
-	    doi.doi_bonus_type, obj_num, NULL);
+	    doi.doi_bonus_type, obj_num, NULL, NULL);
 	if (zp == NULL) {
 		err = ENOENT;
 	} else {
@@ -980,13 +985,24 @@ zfs_zinactive(znode_t *zp)
 {
 	zfs_sb_t *zsb = ZTOZSB(zp);
 	uint64_t z_id = zp->z_id;
+	boolean_t drop_mutex = 0;
 
 	ASSERT(zp->z_sa_hdl);
 
 	/*
-	 * Don't allow a zfs_zget() while were trying to release this znode
+	 * Don't allow a zfs_zget() while were trying to release this znode.
+	 *
+	 * Linux allows direct memory reclaim which means that any KM_SLEEP
+	 * allocation may trigger inode eviction.  This can lead to a deadlock
+	 * through the ->shrink_icache_memory()->evict()->zfs_inactive()->
+	 * zfs_zinactive() call path.  To avoid this deadlock the process
+	 * must not reacquire the mutex when it is already holding it.
 	 */
-	ZFS_OBJ_HOLD_ENTER(zsb, z_id);
+	if (!ZFS_OBJ_HOLD_OWNED(zsb, z_id)) {
+		ZFS_OBJ_HOLD_ENTER(zsb, z_id);
+		drop_mutex = 1;
+	}
+
 	mutex_enter(&zp->z_lock);
 
 	/*
@@ -995,14 +1011,19 @@ zfs_zinactive(znode_t *zp)
 	 */
 	if (zp->z_unlinked) {
 		mutex_exit(&zp->z_lock);
-		ZFS_OBJ_HOLD_EXIT(zsb, z_id);
+
+		if (drop_mutex)
+			ZFS_OBJ_HOLD_EXIT(zsb, z_id);
+
 		zfs_rmnode(zp);
 		return;
 	}
 
 	mutex_exit(&zp->z_lock);
 	zfs_znode_dmu_fini(zp);
-	ZFS_OBJ_HOLD_EXIT(zsb, z_id);
+
+	if (drop_mutex)
+		ZFS_OBJ_HOLD_EXIT(zsb, z_id);
 }
 
 void