1 files changed, 133 insertions, 75 deletions

diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 8d292fbae659..451b00c86f6c 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -55,8 +55,7 @@ static inline void btrfs_init_delayed_node(
         delayed_node->inode_id = inode_id;
         atomic_set(&delayed_node->refs, 0);
         delayed_node->count = 0;
-        delayed_node->in_list = 0;
-        delayed_node->inode_dirty = 0;
+        delayed_node->flags = 0;
         delayed_node->ins_root = RB_ROOT;
         delayed_node->del_root = RB_ROOT;
         mutex_init(&delayed_node->mutex);
@@ -172,7 +171,7 @@ static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
                                      int mod)
 {
         spin_lock(&root->lock);
-        if (node->in_list) {
+        if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
                 if (!list_empty(&node->p_list))
                         list_move_tail(&node->p_list, &root->prepare_list);
                 else if (mod)
@@ -182,7 +181,7 @@ static void btrfs_queue_delayed_node(struct btrfs_delayed_root *root,
                 list_add_tail(&node->p_list, &root->prepare_list);
                 atomic_inc(&node->refs);        /* inserted into list */
                 root->nodes++;
-                node->in_list = 1;
+                set_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
         }
         spin_unlock(&root->lock);
 }
@@ -192,13 +191,13 @@ static void btrfs_dequeue_delayed_node(struct btrfs_delayed_root *root,
                                        struct btrfs_delayed_node *node)
 {
         spin_lock(&root->lock);
-        if (node->in_list) {
+        if (test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
                 root->nodes--;
                 atomic_dec(&node->refs);        /* not in the list */
                 list_del_init(&node->n_list);
                 if (!list_empty(&node->p_list))
                         list_del_init(&node->p_list);
-                node->in_list = 0;
+                clear_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags);
         }
         spin_unlock(&root->lock);
 }
@@ -231,7 +230,8 @@ static struct btrfs_delayed_node *btrfs_next_delayed_node(
 
         delayed_root = node->root->fs_info->delayed_root;
         spin_lock(&delayed_root->lock);
-        if (!node->in_list) {   /* not in the list */
+        if (!test_bit(BTRFS_DELAYED_NODE_IN_LIST, &node->flags)) {
+                /* not in the list */
                 if (list_empty(&delayed_root->node_list))
                         goto out;
                 p = delayed_root->node_list.next;
@@ -1004,9 +1004,10 @@ static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
 {
         struct btrfs_delayed_root *delayed_root;
 
-        if (delayed_node && delayed_node->inode_dirty) {
+        if (delayed_node &&
+            test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
                 BUG_ON(!delayed_node->root);
-                delayed_node->inode_dirty = 0;
+                clear_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
                 delayed_node->count--;
 
                 delayed_root = delayed_node->root->fs_info->delayed_root;
@@ -1014,6 +1015,18 @@ static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
         }
 }
 
+static void btrfs_release_delayed_iref(struct btrfs_delayed_node *delayed_node)
+{
+        struct btrfs_delayed_root *delayed_root;
+
+        ASSERT(delayed_node->root);
+        clear_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
+        delayed_node->count--;
+
+        delayed_root = delayed_node->root->fs_info->delayed_root;
+        finish_one_item(delayed_root);
+}
+
 static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
                                         struct btrfs_root *root,
                                         struct btrfs_path *path,
@@ -1022,13 +1035,19 @@ static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
         struct btrfs_key key;
         struct btrfs_inode_item *inode_item;
         struct extent_buffer *leaf;
+        int mod;
         int ret;
 
         key.objectid = node->inode_id;
         btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
         key.offset = 0;
 
-        ret = btrfs_lookup_inode(trans, root, path, &key, 1);
+        if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
+                mod = -1;
+        else
+                mod = 1;
+
+        ret = btrfs_lookup_inode(trans, root, path, &key, mod);
         if (ret > 0) {
                 btrfs_release_path(path);
                 return -ENOENT;
@@ -1036,19 +1055,58 @@ static int __btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
                 return ret;
         }
 
-        btrfs_unlock_up_safe(path, 1);
         leaf = path->nodes[0];
         inode_item = btrfs_item_ptr(leaf, path->slots[0],
                                     struct btrfs_inode_item);
         write_extent_buffer(leaf, &node->inode_item, (unsigned long)inode_item,
                             sizeof(struct btrfs_inode_item));
         btrfs_mark_buffer_dirty(leaf);
-        btrfs_release_path(path);
 
+        if (!test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &node->flags))
+                goto no_iref;
+
+        path->slots[0]++;
+        if (path->slots[0] >= btrfs_header_nritems(leaf))
+                goto search;
+again:
+        btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+        if (key.objectid != node->inode_id)
+                goto out;
+
+        if (key.type != BTRFS_INODE_REF_KEY &&
+            key.type != BTRFS_INODE_EXTREF_KEY)
+                goto out;
+
+        /*
+         * Delayed iref deletion is for the inode who has only one link,
+         * so there is only one iref. The case that several irefs are
+         * in the same item doesn't exist.
+         */
+        btrfs_del_item(trans, root, path);
+out:
+        btrfs_release_delayed_iref(node);
+no_iref:
+        btrfs_release_path(path);
+err_out:
         btrfs_delayed_inode_release_metadata(root, node);
         btrfs_release_delayed_inode(node);
 
-        return 0;
+        return ret;
+
+search:
+        btrfs_release_path(path);
+
+        btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY);
+        key.offset = -1;
+        ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+        if (ret < 0)
+                goto err_out;
+        ASSERT(ret);
+
+        ret = 0;
+        leaf = path->nodes[0];
+        path->slots[0]--;
+        goto again;
 }
 
 static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
@@ -1059,7 +1117,7 @@ static inline int btrfs_update_delayed_inode(struct btrfs_trans_handle *trans,
         int ret;
 
         mutex_lock(&node->mutex);
-        if (!node->inode_dirty) {
+        if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &node->flags)) {
                 mutex_unlock(&node->mutex);
                 return 0;
         }
@@ -1203,7 +1261,7 @@ int btrfs_commit_inode_delayed_inode(struct inode *inode)
                 return 0;
 
         mutex_lock(&delayed_node->mutex);
-        if (!delayed_node->inode_dirty) {
+        if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
                 mutex_unlock(&delayed_node->mutex);
                 btrfs_release_delayed_node(delayed_node);
                 return 0;
@@ -1227,7 +1285,7 @@ int btrfs_commit_inode_delayed_inode(struct inode *inode)
         trans->block_rsv = &delayed_node->root->fs_info->delayed_block_rsv;
 
         mutex_lock(&delayed_node->mutex);
-        if (delayed_node->inode_dirty)
+        if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags))
                 ret = __btrfs_update_delayed_inode(trans, delayed_node->root,
                                                    path, delayed_node);
         else
@@ -1300,36 +1358,9 @@ again:
         trans->block_rsv = &root->fs_info->delayed_block_rsv;
 
         __btrfs_commit_inode_delayed_items(trans, path, delayed_node);
-        /*
-         * Maybe new delayed items have been inserted, so we need requeue
-         * the work. Besides that, we must dequeue the empty delayed nodes
-         * to avoid the race between delayed items balance and the worker.
-         * The race like this:
-         *      Task1                           Worker thread
-         *                                      count == 0, needn't requeue
-         *                                        also needn't insert the
-         *                                        delayed node into prepare
-         *                                        list again.
-         *      add lots of delayed items
-         *      queue the delayed node
-         *        already in the list,
-         *        and not in the prepare
-         *        list, it means the delayed
-         *        node is being dealt with
-         *        by the worker.
-         *      do delayed items balance
-         *        the delayed node is being
-         *        dealt with by the worker
-         *        now, just wait.
-         *                                      the worker goto idle.
-         * Task1 will sleep until the transaction is commited.
-         */
-        mutex_lock(&delayed_node->mutex);
-        btrfs_dequeue_delayed_node(root->fs_info->delayed_root, delayed_node);
-        mutex_unlock(&delayed_node->mutex);
 
         trans->block_rsv = block_rsv;
-        btrfs_end_transaction_dmeta(trans, root);
+        btrfs_end_transaction(trans, root);
         btrfs_btree_balance_dirty_nodelay(root);
 
 release_path:
@@ -1376,52 +1407,41 @@ void btrfs_assert_delayed_root_empty(struct btrfs_root *root)
         WARN_ON(btrfs_first_delayed_node(delayed_root));
 }
 
-static int refs_newer(struct btrfs_delayed_root *delayed_root,
-                      int seq, int count)
+static int could_end_wait(struct btrfs_delayed_root *delayed_root, int seq)
 {
         int val = atomic_read(&delayed_root->items_seq);
 
-        if (val < seq || val >= seq + count)
+        if (val < seq || val >= seq + BTRFS_DELAYED_BATCH)
+                return 1;
+
+        if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
                 return 1;
+
         return 0;
 }
 
 void btrfs_balance_delayed_items(struct btrfs_root *root)
 {
         struct btrfs_delayed_root *delayed_root;
-        int seq;
 
         delayed_root = btrfs_get_delayed_root(root);
 
         if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND)
                 return;
 
-        seq = atomic_read(&delayed_root->items_seq);
-
         if (atomic_read(&delayed_root->items) >= BTRFS_DELAYED_WRITEBACK) {
+                int seq;
                 int ret;
-                DEFINE_WAIT(__wait);
+
+                seq = atomic_read(&delayed_root->items_seq);
 
                 ret = btrfs_wq_run_delayed_node(delayed_root, root, 0);
                 if (ret)
                         return;
 
-                while (1) {
-                        prepare_to_wait(&delayed_root->wait, &__wait,
-                                        TASK_INTERRUPTIBLE);
-
-                        if (refs_newer(delayed_root, seq,
-                                       BTRFS_DELAYED_BATCH) ||
-                            atomic_read(&delayed_root->items) <
-                            BTRFS_DELAYED_BACKGROUND) {
-                                break;
-                        }
-                        if (!signal_pending(current))
-                                schedule();
-                        else
-                                break;
-                }
-                finish_wait(&delayed_root->wait, &__wait);
+                wait_event_interruptible(delayed_root->wait,
+                                         could_end_wait(delayed_root, seq));
+                return;
         }
 
         btrfs_wq_run_delayed_node(delayed_root, root, BTRFS_DELAYED_BATCH);
@@ -1472,9 +1492,9 @@ int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
         mutex_lock(&delayed_node->mutex);
         ret = __btrfs_add_delayed_insertion_item(delayed_node, delayed_item);
         if (unlikely(ret)) {
-                printk(KERN_ERR "err add delayed dir index item(name: %.*s) "
+                btrfs_err(root->fs_info, "err add delayed dir index item(name: %.*s) "
                                 "into the insertion tree of the delayed node"
-                                "(root id: %llu, inode id: %llu, errno: %d)\n",
+                                "(root id: %llu, inode id: %llu, errno: %d)",
                                 name_len, name, delayed_node->root->objectid,
                                 delayed_node->inode_id, ret);
                 BUG();
@@ -1544,9 +1564,9 @@ int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
         mutex_lock(&node->mutex);
         ret = __btrfs_add_delayed_deletion_item(node, item);
         if (unlikely(ret)) {
-                printk(KERN_ERR "err add delayed dir index item(index: %llu) "
+                btrfs_err(root->fs_info, "err add delayed dir index item(index: %llu) "
                                 "into the deletion tree of the delayed node"
-                                "(root id: %llu, inode id: %llu, errno: %d)\n",
+                                "(root id: %llu, inode id: %llu, errno: %d)",
                                 index, node->root->objectid, node->inode_id,
                                 ret);
                 BUG();
@@ -1759,7 +1779,7 @@ int btrfs_fill_inode(struct inode *inode, u32 *rdev)
                 return -ENOENT;
 
         mutex_lock(&delayed_node->mutex);
-        if (!delayed_node->inode_dirty) {
+        if (!test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
                 mutex_unlock(&delayed_node->mutex);
                 btrfs_release_delayed_node(delayed_node);
                 return -ENOENT;
@@ -1810,7 +1830,7 @@ int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
                 return PTR_ERR(delayed_node);
 
         mutex_lock(&delayed_node->mutex);
-        if (delayed_node->inode_dirty) {
+        if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
                 fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
                 goto release_node;
         }
@@ -1821,7 +1841,7 @@ int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
                 goto release_node;
 
         fill_stack_inode_item(trans, &delayed_node->inode_item, inode);
-        delayed_node->inode_dirty = 1;
+        set_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags);
         delayed_node->count++;
         atomic_inc(&root->fs_info->delayed_root->items);
 release_node:
@@ -1830,6 +1850,41 @@ release_node:
         return ret;
 }
 
+int btrfs_delayed_delete_inode_ref(struct inode *inode)
+{
+        struct btrfs_delayed_node *delayed_node;
+
+        delayed_node = btrfs_get_or_create_delayed_node(inode);
+        if (IS_ERR(delayed_node))
+                return PTR_ERR(delayed_node);
+
+        /*
+         * We don't reserve space for inode ref deletion is because:
+         * - We ONLY do async inode ref deletion for the inode who has only
+         *   one link(i_nlink == 1), it means there is only one inode ref.
+         *   And in most case, the inode ref and the inode item are in the
+         *   same leaf, and we will deal with them at the same time.
+         *   Since we are sure we will reserve the space for the inode item,
+         *   it is unnecessary to reserve space for inode ref deletion.
+         * - If the inode ref and the inode item are not in the same leaf,
+         *   We also needn't worry about enospc problem, because we reserve
+         *   much more space for the inode update than it needs.
+         * - At the worst, we can steal some space from the global reservation.
+         *   It is very rare.
+         */
+        mutex_lock(&delayed_node->mutex);
+        if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
+                goto release_node;
+
+        set_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags);
+        delayed_node->count++;
+        atomic_inc(&BTRFS_I(inode)->root->fs_info->delayed_root->items);
+release_node:
+        mutex_unlock(&delayed_node->mutex);
+        btrfs_release_delayed_node(delayed_node);
+        return 0;
+}
+
 static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
 {
         struct btrfs_root *root = delayed_node->root;
@@ -1852,7 +1907,10 @@ static void __btrfs_kill_delayed_node(struct btrfs_delayed_node *delayed_node)
                 btrfs_release_delayed_item(prev_item);
         }
 
-        if (delayed_node->inode_dirty) {
+        if (test_bit(BTRFS_DELAYED_NODE_DEL_IREF, &delayed_node->flags))
+                btrfs_release_delayed_iref(delayed_node);
+
+        if (test_bit(BTRFS_DELAYED_NODE_INODE_DIRTY, &delayed_node->flags)) {
                 btrfs_delayed_inode_release_metadata(root, delayed_node);
                 btrfs_release_delayed_inode(delayed_node);
         }