Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs fixes from Chris Mason:
 "I've split out the big send/receive update from my last pull request
  and now have just the fixes in my for-linus branch.  The send/recv
  branch will wander over to linux-next shortly though.

  The largest patches in this pull are Josef's patches to fix DIO
  locking problems and his patch to fix a crash during balance.  They
  are both well tested.

  The rest are smaller fixes that we've had queued.  The last rc came
  out while I was hacking new and exciting ways to recover from a
  misplaced rm -rf on my dev box, so these missed rc3."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (25 commits)
  Btrfs: fix that repair code is spuriously executed for transid failures
  Btrfs: fix ordered extent leak when failing to start a transaction
  Btrfs: fix a dio write regression
  Btrfs: fix deadlock with freeze and sync V2
  Btrfs: revert checksum error statistic which can cause a BUG()
  Btrfs: remove superblock writing after fatal error
  Btrfs: allow delayed refs to be merged
  Btrfs: fix enospc problems when deleting a subvol
  Btrfs: fix wrong mtime and ctime when creating snapshots
  Btrfs: fix race in run_clustered_refs
  Btrfs: don't run __tree_mod_log_free_eb on leaves
  Btrfs: increase the size of the free space cache
  Btrfs: barrier before waitqueue_active
  Btrfs: fix deadlock in wait_for_more_refs
  btrfs: fix second lock in btrfs_delete_delayed_items()
  Btrfs: don't allocate a seperate csums array for direct reads
  Btrfs: do not strdup non existent strings
  Btrfs: do not use missing devices when showing devname
  Btrfs: fix that error value is changed by mistake
  Btrfs: lock extents as we map them in DIO
  ...

21 files changed, 418 insertions, 376 deletions

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index a256f3b2a845..ff6475f409d6 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1438,10 +1438,10 @@ int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info,
         ret = extent_from_logical(fs_info, logical, path,
                                         &found_key);
         btrfs_release_path(path);
-        if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
-                ret = -EINVAL;
         if (ret < 0)
                 return ret;
+        if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
+                return -EINVAL;
 
         extent_item_pos = logical - found_key.objectid;
         ret = iterate_extent_inodes(fs_info, found_key.objectid,
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 86eff48dab78..43d1c5a3a030 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -818,6 +818,7 @@ static void free_workspace(int type, struct list_head *workspace)
         btrfs_compress_op[idx]->free_workspace(workspace);
         atomic_dec(alloc_workspace);
 wake:
+        smp_mb();
         if (waitqueue_active(workspace_wait))
                 wake_up(workspace_wait);
 }
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 9d7621f271ff..6d183f60d63a 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -421,12 +421,6 @@ void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info,
         spin_unlock(&fs_info->tree_mod_seq_lock);
 
         /*
-         * we removed the lowest blocker from the blocker list, so there may be
-         * more processible delayed refs.
-         */
-        wake_up(&fs_info->tree_mod_seq_wait);
-
-        /*
          * anything that's lower than the lowest existing (read: blocked)
          * sequence number can be removed from the tree.
          */
@@ -631,6 +625,9 @@ __tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, struct extent_buffer *eb)
         u32 nritems;
         int ret;
 
+        if (btrfs_header_level(eb) == 0)
+                return;
+
         nritems = btrfs_header_nritems(eb);
         for (i = nritems - 1; i >= 0; i--) {
                 ret = tree_mod_log_insert_key_locked(fs_info, eb, i,
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 4bab807227ad..0d195b507660 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1252,7 +1252,6 @@ struct btrfs_fs_info {
         atomic_t tree_mod_seq;
         struct list_head tree_mod_seq_list;
         struct seq_list tree_mod_seq_elem;
-        wait_queue_head_t tree_mod_seq_wait;
 
         /* this protects tree_mod_log */
         rwlock_t tree_mod_log_lock;
@@ -3192,7 +3191,7 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
 int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
                           struct bio *bio, u32 *dst);
 int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
-                              struct bio *bio, u64 logical_offset, u32 *dst);
+                              struct bio *bio, u64 logical_offset);
 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root,
                              u64 objectid, u64 pos,
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 335605c8ceab..07d5eeb1e6f1 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -512,8 +512,8 @@ static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
 
         rb_erase(&delayed_item->rb_node, root);
         delayed_item->delayed_node->count--;
-        atomic_dec(&delayed_root->items);
-        if (atomic_read(&delayed_root->items) < BTRFS_DELAYED_BACKGROUND &&
+        if (atomic_dec_return(&delayed_root->items) <
+            BTRFS_DELAYED_BACKGROUND &&
             waitqueue_active(&delayed_root->wait))
                 wake_up(&delayed_root->wait);
 }
@@ -1028,9 +1028,10 @@ do_again:
                 btrfs_release_delayed_item(prev);
                 ret = 0;
                 btrfs_release_path(path);
-                if (curr)
+                if (curr) {
+                        mutex_unlock(&node->mutex);
                         goto do_again;
-                else
+                } else
                         goto delete_fail;
         }
 
@@ -1055,8 +1056,7 @@ static void btrfs_release_delayed_inode(struct btrfs_delayed_node *delayed_node)
                 delayed_node->count--;
 
                 delayed_root = delayed_node->root->fs_info->delayed_root;
-                atomic_dec(&delayed_root->items);
-                if (atomic_read(&delayed_root->items) <
+                if (atomic_dec_return(&delayed_root->items) <
                     BTRFS_DELAYED_BACKGROUND &&
                     waitqueue_active(&delayed_root->wait))
                         wake_up(&delayed_root->wait);
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index da7419ed01bb..ae9411773397 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -38,17 +38,14 @@
 static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref2,
                           struct btrfs_delayed_tree_ref *ref1)
 {
-        if (ref1->node.type == BTRFS_TREE_BLOCK_REF_KEY) {
-                if (ref1->root < ref2->root)
-                        return -1;
-                if (ref1->root > ref2->root)
-                        return 1;
-        } else {
-                if (ref1->parent < ref2->parent)
-                        return -1;
-                if (ref1->parent > ref2->parent)
-                        return 1;
-        }
+        if (ref1->root < ref2->root)
+                return -1;
+        if (ref1->root > ref2->root)
+                return 1;
+        if (ref1->parent < ref2->parent)
+                return -1;
+        if (ref1->parent > ref2->parent)
+                return 1;
         return 0;
 }
 
@@ -85,7 +82,8 @@ static int comp_data_refs(struct btrfs_delayed_data_ref *ref2,
  * type of the delayed backrefs and content of delayed backrefs.
  */
 static int comp_entry(struct btrfs_delayed_ref_node *ref2,
-                      struct btrfs_delayed_ref_node *ref1)
+                      struct btrfs_delayed_ref_node *ref1,
+                      bool compare_seq)
 {
         if (ref1->bytenr < ref2->bytenr)
                 return -1;
@@ -102,10 +100,12 @@ static int comp_entry(struct btrfs_delayed_ref_node *ref2,
         if (ref1->type > ref2->type)
                 return 1;
         /* merging of sequenced refs is not allowed */
-        if (ref1->seq < ref2->seq)
-                return -1;
-        if (ref1->seq > ref2->seq)
-                return 1;
+        if (compare_seq) {
+                if (ref1->seq < ref2->seq)
+                        return -1;
+                if (ref1->seq > ref2->seq)
+                        return 1;
+        }
         if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
             ref1->type == BTRFS_SHARED_BLOCK_REF_KEY) {
                 return comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref2),
@@ -139,7 +139,7 @@ static struct btrfs_delayed_ref_node *tree_insert(struct rb_root *root,
                 entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
                                  rb_node);
 
-                cmp = comp_entry(entry, ins);
+                cmp = comp_entry(entry, ins, 1);
                 if (cmp < 0)
                         p = &(*p)->rb_left;
                 else if (cmp > 0)
@@ -233,6 +233,114 @@ int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
         return 0;
 }
 
+static void inline drop_delayed_ref(struct btrfs_trans_handle *trans,
+                                    struct btrfs_delayed_ref_root *delayed_refs,
+                                    struct btrfs_delayed_ref_node *ref)
+{
+        rb_erase(&ref->rb_node, &delayed_refs->root);
+        ref->in_tree = 0;
+        btrfs_put_delayed_ref(ref);
+        delayed_refs->num_entries--;
+        if (trans->delayed_ref_updates)
+                trans->delayed_ref_updates--;
+}
+
+static int merge_ref(struct btrfs_trans_handle *trans,
+                     struct btrfs_delayed_ref_root *delayed_refs,
+                     struct btrfs_delayed_ref_node *ref, u64 seq)
+{
+        struct rb_node *node;
+        int merged = 0;
+        int mod = 0;
+        int done = 0;
+
+        node = rb_prev(&ref->rb_node);
+        while (node) {
+                struct btrfs_delayed_ref_node *next;
+
+                next = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
+                node = rb_prev(node);
+                if (next->bytenr != ref->bytenr)
+                        break;
+                if (seq && next->seq >= seq)
+                        break;
+                if (comp_entry(ref, next, 0))
+                        continue;
+
+                if (ref->action == next->action) {
+                        mod = next->ref_mod;
+                } else {
+                        if (ref->ref_mod < next->ref_mod) {
+                                struct btrfs_delayed_ref_node *tmp;
+
+                                tmp = ref;
+                                ref = next;
+                                next = tmp;
+                                done = 1;
+                        }
+                        mod = -next->ref_mod;
+                }
+
+                merged++;
+                drop_delayed_ref(trans, delayed_refs, next);
+                ref->ref_mod += mod;
+                if (ref->ref_mod == 0) {
+                        drop_delayed_ref(trans, delayed_refs, ref);
+                        break;
+                } else {
+                        /*
+                         * You can't have multiples of the same ref on a tree
+                         * block.
+                         */
+                        WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
+                                ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
+                }
+
+                if (done)
+                        break;
+                node = rb_prev(&ref->rb_node);
+        }
+
+        return merged;
+}
+
+void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
+                              struct btrfs_fs_info *fs_info,
+                              struct btrfs_delayed_ref_root *delayed_refs,
+                              struct btrfs_delayed_ref_head *head)
+{
+        struct rb_node *node;
+        u64 seq = 0;
+
+        spin_lock(&fs_info->tree_mod_seq_lock);
+        if (!list_empty(&fs_info->tree_mod_seq_list)) {
+                struct seq_list *elem;
+
+                elem = list_first_entry(&fs_info->tree_mod_seq_list,
+                                        struct seq_list, list);
+                seq = elem->seq;
+        }
+        spin_unlock(&fs_info->tree_mod_seq_lock);
+
+        node = rb_prev(&head->node.rb_node);
+        while (node) {
+                struct btrfs_delayed_ref_node *ref;
+
+                ref = rb_entry(node, struct btrfs_delayed_ref_node,
+                               rb_node);
+                if (ref->bytenr != head->node.bytenr)
+                        break;
+
+                /* We can't merge refs that are outside of our seq count */
+                if (seq && ref->seq >= seq)
+                        break;
+                if (merge_ref(trans, delayed_refs, ref, seq))
+                        node = rb_prev(&head->node.rb_node);
+                else
+                        node = rb_prev(node);
+        }
+}
+
 int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
                             struct btrfs_delayed_ref_root *delayed_refs,
                             u64 seq)
@@ -336,18 +444,11 @@ update_existing_ref(struct btrfs_trans_handle *trans,
                  * every changing the extent allocation tree.
                  */
                 existing->ref_mod--;
-                if (existing->ref_mod == 0) {
-                        rb_erase(&existing->rb_node,
-                                 &delayed_refs->root);
-                        existing->in_tree = 0;
-                        btrfs_put_delayed_ref(existing);
-                        delayed_refs->num_entries--;
-                        if (trans->delayed_ref_updates)
-                                trans->delayed_ref_updates--;
-                } else {
+                if (existing->ref_mod == 0)
+                        drop_delayed_ref(trans, delayed_refs, existing);
+                else
                         WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
                                 existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
-                }
         } else {
                 WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
                         existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
@@ -662,9 +763,6 @@ int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
         add_delayed_tree_ref(fs_info, trans, &ref->node, bytenr,
                                    num_bytes, parent, ref_root, level, action,
                                    for_cow);
-        if (!need_ref_seq(for_cow, ref_root) &&
-            waitqueue_active(&fs_info->tree_mod_seq_wait))
-                wake_up(&fs_info->tree_mod_seq_wait);
         spin_unlock(&delayed_refs->lock);
         if (need_ref_seq(for_cow, ref_root))
                 btrfs_qgroup_record_ref(trans, &ref->node, extent_op);
@@ -713,9 +811,6 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
         add_delayed_data_ref(fs_info, trans, &ref->node, bytenr,
                                    num_bytes, parent, ref_root, owner, offset,
                                    action, for_cow);
-        if (!need_ref_seq(for_cow, ref_root) &&
-            waitqueue_active(&fs_info->tree_mod_seq_wait))
-                wake_up(&fs_info->tree_mod_seq_wait);
         spin_unlock(&delayed_refs->lock);
         if (need_ref_seq(for_cow, ref_root))
                 btrfs_qgroup_record_ref(trans, &ref->node, extent_op);
@@ -744,8 +839,6 @@ int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
                                    num_bytes, BTRFS_UPDATE_DELAYED_HEAD,
                                    extent_op->is_data);
 
-        if (waitqueue_active(&fs_info->tree_mod_seq_wait))
-                wake_up(&fs_info->tree_mod_seq_wait);
         spin_unlock(&delayed_refs->lock);
         return 0;
 }
diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index 0d7c90c366b6..ab5300595847 100644
--- a/fs/btrfs/delayed-ref.h
+++ b/fs/btrfs/delayed-ref.h
@@ -167,6 +167,10 @@ int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
                                 struct btrfs_trans_handle *trans,
                                 u64 bytenr, u64 num_bytes,
                                 struct btrfs_delayed_extent_op *extent_op);
+void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
+                              struct btrfs_fs_info *fs_info,
+                              struct btrfs_delayed_ref_root *delayed_refs,
+                              struct btrfs_delayed_ref_head *head);
 
 struct btrfs_delayed_ref_head *
 btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 62e0cafd6e25..22e98e04c2ea 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -377,9 +377,13 @@ static int btree_read_extent_buffer_pages(struct btrfs_root *root,
                 ret = read_extent_buffer_pages(io_tree, eb, start,
                                                WAIT_COMPLETE,
                                                btree_get_extent, mirror_num);
-                if (!ret && !verify_parent_transid(io_tree, eb,
+                if (!ret) {
+                        if (!verify_parent_transid(io_tree, eb,
                                                    parent_transid, 0))
-                        break;
+                                break;
+                        else
+                                ret = -EIO;
+                }
 
                 /*
                  * This buffer's crc is fine, but its contents are corrupted, so
@@ -754,9 +758,7 @@ static void run_one_async_done(struct btrfs_work *work)
         limit = btrfs_async_submit_limit(fs_info);
         limit = limit * 2 / 3;
 
-        atomic_dec(&fs_info->nr_async_submits);
-
-        if (atomic_read(&fs_info->nr_async_submits) < limit &&
+        if (atomic_dec_return(&fs_info->nr_async_submits) < limit &&
             waitqueue_active(&fs_info->async_submit_wait))
                 wake_up(&fs_info->async_submit_wait);
 
@@ -2032,8 +2034,6 @@ int open_ctree(struct super_block *sb,
         fs_info->free_chunk_space = 0;
         fs_info->tree_mod_log = RB_ROOT;
 
-        init_waitqueue_head(&fs_info->tree_mod_seq_wait);
-
         /* readahead state */
         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);
         spin_lock_init(&fs_info->reada_lock);
@@ -2528,8 +2528,7 @@ retry_root_backup:
                 goto fail_trans_kthread;
 
         /* do not make disk changes in broken FS */
-        if (btrfs_super_log_root(disk_super) != 0 &&
-            !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) {
+        if (btrfs_super_log_root(disk_super) != 0) {
                 u64 bytenr = btrfs_super_log_root(disk_super);
 
                 if (fs_devices->rw_devices == 0) {
@@ -3189,30 +3188,14 @@ int close_ctree(struct btrfs_root *root)
         /* clear out the rbtree of defraggable inodes */
         btrfs_run_defrag_inodes(fs_info);
 
-        /*
-         * Here come 2 situations when btrfs is broken to flip readonly:
-         *
-         * 1. when btrfs flips readonly somewhere else before
-         * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
-         * and btrfs will skip to write sb directly to keep
-         * ERROR state on disk.
-         *
-         * 2. when btrfs flips readonly just in btrfs_commit_super,
-         * and in such case, btrfs cannot write sb via btrfs_commit_super,
-         * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
-         * btrfs will cleanup all FS resources first and write sb then.
-         */
         if (!(fs_info->sb->s_flags & MS_RDONLY)) {
                 ret = btrfs_commit_super(root);
                 if (ret)
                         printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
         }
 
-        if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
-                ret = btrfs_error_commit_super(root);
-                if (ret)
-                        printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
-        }
+        if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
+                btrfs_error_commit_super(root);
 
         btrfs_put_block_group_cache(fs_info);
 
@@ -3434,18 +3417,11 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
         if (read_only)
                 return 0;
 
-        if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
-                printk(KERN_WARNING "warning: mount fs with errors, "
-                       "running btrfsck is recommended\n");
-        }
-
         return 0;
 }
 
-int btrfs_error_commit_super(struct btrfs_root *root)
+void btrfs_error_commit_super(struct btrfs_root *root)
 {
-        int ret;
-
         mutex_lock(&root->fs_info->cleaner_mutex);
         btrfs_run_delayed_iputs(root);
         mutex_unlock(&root->fs_info->cleaner_mutex);
@@ -3455,10 +3431,6 @@ int btrfs_error_commit_super(struct btrfs_root *root)
 
         /* cleanup FS via transaction */
         btrfs_cleanup_transaction(root);
-
-        ret = write_ctree_super(NULL, root, 0);
-
-        return ret;
 }
 
 static void btrfs_destroy_ordered_operations(struct btrfs_root *root)
@@ -3782,14 +3754,17 @@ int btrfs_cleanup_transaction(struct btrfs_root *root)
                 /* FIXME: cleanup wait for commit */
                 t->in_commit = 1;
                 t->blocked = 1;
+                smp_mb();
                 if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
                         wake_up(&root->fs_info->transaction_blocked_wait);
 
                 t->blocked = 0;
+                smp_mb();
                 if (waitqueue_active(&root->fs_info->transaction_wait))
                         wake_up(&root->fs_info->transaction_wait);
 
                 t->commit_done = 1;
+                smp_mb();
                 if (waitqueue_active(&t->commit_wait))
                         wake_up(&t->commit_wait);
 
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 95e147eea239..c5b00a735fef 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -54,7 +54,7 @@ int write_ctree_super(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root, int max_mirrors);
 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
 int btrfs_commit_super(struct btrfs_root *root);
-int btrfs_error_commit_super(struct btrfs_root *root);
+void btrfs_error_commit_super(struct btrfs_root *root);
 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
                                             u64 bytenr, u32 blocksize);
 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 4e1b153b7c47..ba58024d40d3 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2252,6 +2252,16 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
                 }
 
                 /*
+                 * We need to try and merge add/drops of the same ref since we
+                 * can run into issues with relocate dropping the implicit ref
+                 * and then it being added back again before the drop can
+                 * finish.  If we merged anything we need to re-loop so we can
+                 * get a good ref.
+                 */
+                btrfs_merge_delayed_refs(trans, fs_info, delayed_refs,
+                                         locked_ref);
+
+                /*
                  * locked_ref is the head node, so we have to go one
                  * node back for any delayed ref updates
                  */
@@ -2318,12 +2328,23 @@ static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
                 ref->in_tree = 0;
                 rb_erase(&ref->rb_node, &delayed_refs->root);
                 delayed_refs->num_entries--;
-                /*
-                 * we modified num_entries, but as we're currently running
-                 * delayed refs, skip
-                 *     wake_up(&delayed_refs->seq_wait);
-                 * here.
-                 */
+                if (locked_ref) {
+                        /*
+                         * when we play the delayed ref, also correct the
+                         * ref_mod on head
+                         */
+                        switch (ref->action) {
+                        case BTRFS_ADD_DELAYED_REF:
+                        case BTRFS_ADD_DELAYED_EXTENT:
+                                locked_ref->node.ref_mod -= ref->ref_mod;
+                                break;
+                        case BTRFS_DROP_DELAYED_REF:
+                                locked_ref->node.ref_mod += ref->ref_mod;
+                                break;
+                        default:
+                                WARN_ON(1);
+                        }
+                }
                 spin_unlock(&delayed_refs->lock);
 
                 ret = run_one_delayed_ref(trans, root, ref, extent_op,
@@ -2350,22 +2371,6 @@ next:
         return count;
 }
 
-static void wait_for_more_refs(struct btrfs_fs_info *fs_info,
-                               struct btrfs_delayed_ref_root *delayed_refs,
-                               unsigned long num_refs,
-                               struct list_head *first_seq)
-{
-        spin_unlock(&delayed_refs->lock);
-        pr_debug("waiting for more refs (num %ld, first %p)\n",
-                 num_refs, first_seq);
-        wait_event(fs_info->tree_mod_seq_wait,
-                   num_refs != delayed_refs->num_entries ||
-                   fs_info->tree_mod_seq_list.next != first_seq);
-        pr_debug("done waiting for more refs (num %ld, first %p)\n",
-                 delayed_refs->num_entries, fs_info->tree_mod_seq_list.next);
-        spin_lock(&delayed_refs->lock);
-}
-
 #ifdef SCRAMBLE_DELAYED_REFS
 /*
  * Normally delayed refs get processed in ascending bytenr order. This
@@ -2460,13 +2465,11 @@ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
         struct btrfs_delayed_ref_root *delayed_refs;
         struct btrfs_delayed_ref_node *ref;
         struct list_head cluster;
-        struct list_head *first_seq = NULL;
         int ret;
         u64 delayed_start;
         int run_all = count == (unsigned long)-1;
         int run_most = 0;
-        unsigned long num_refs = 0;
-        int consider_waiting;
+        int loops;
 
         /* We'll clean this up in btrfs_cleanup_transaction */
         if (trans->aborted)
@@ -2484,7 +2487,7 @@ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
         delayed_refs = &trans->transaction->delayed_refs;
         INIT_LIST_HEAD(&cluster);
 again:
-        consider_waiting = 0;
+        loops = 0;
         spin_lock(&delayed_refs->lock);
 
 #ifdef SCRAMBLE_DELAYED_REFS
@@ -2512,31 +2515,6 @@ again:
                 if (ret)
                         break;
 
-                if (delayed_start >= delayed_refs->run_delayed_start) {
-                        if (consider_waiting == 0) {
-                                /*
-                                 * btrfs_find_ref_cluster looped. let's do one
-                                 * more cycle. if we don't run any delayed ref
-                                 * during that cycle (because we can't because
-                                 * all of them are blocked) and if the number of
-                                 * refs doesn't change, we avoid busy waiting.
-                                 */
-                                consider_waiting = 1;
-                                num_refs = delayed_refs->num_entries;
-                                first_seq = root->fs_info->tree_mod_seq_list.next;
-                        } else {
-                                wait_for_more_refs(root->fs_info, delayed_refs,
-                                                   num_refs, first_seq);
-                                /*
-                                 * after waiting, things have changed. we
-                                 * dropped the lock and someone else might have
-                                 * run some refs, built new clusters and so on.
-                                 * therefore, we restart staleness detection.
-                                 */
-                                consider_waiting = 0;
-                        }
-                }
-
                 ret = run_clustered_refs(trans, root, &cluster);
                 if (ret < 0) {
                         spin_unlock(&delayed_refs->lock);
@@ -2549,9 +2527,26 @@ again:
                 if (count == 0)
                         break;
 
-                if (ret || delayed_refs->run_delayed_start == 0) {
+                if (delayed_start >= delayed_refs->run_delayed_start) {
+                        if (loops == 0) {
+                                /*
+                                 * btrfs_find_ref_cluster looped. let's do one
+                                 * more cycle. if we don't run any delayed ref
+                                 * during that cycle (because we can't because
+                                 * all of them are blocked), bail out.
+                                 */
+                                loops = 1;
+                        } else {
+                                /*
+                                 * no runnable refs left, stop trying
+                                 */
+                                BUG_ON(run_all);
+                                break;
+                        }
+                }
+                if (ret) {
                         /* refs were run, let's reset staleness detection */
-                        consider_waiting = 0;
+                        loops = 0;
                 }
         }
 
@@ -3007,17 +3002,16 @@ again:
         }
         spin_unlock(&block_group->lock);
 
-        num_pages = (int)div64_u64(block_group->key.offset, 1024 * 1024 * 1024);
+        /*
+         * Try to preallocate enough space based on how big the block group is.
+         * Keep in mind this has to include any pinned space which could end up
+         * taking up quite a bit since it's not folded into the other space
+         * cache.
+         */
+        num_pages = (int)div64_u64(block_group->key.offset, 256 * 1024 * 1024);
         if (!num_pages)
                 num_pages = 1;
 
-        /*
-         * Just to make absolutely sure we have enough space, we're going to
-         * preallocate 12 pages worth of space for each block group.  In
-         * practice we ought to use at most 8, but we need extra space so we can
-         * add our header and have a terminator between the extents and the
-         * bitmaps.
-         */
         num_pages *= 16;
         num_pages *= PAGE_CACHE_SIZE;
 
@@ -4571,8 +4565,10 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
         if (root->fs_info->quota_enabled) {
                 ret = btrfs_qgroup_reserve(root, num_bytes +
                                            nr_extents * root->leafsize);
-                if (ret)
+                if (ret) {
+                        mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
                         return ret;
+                }
         }
 
         ret = reserve_metadata_bytes(root, block_rsv, to_reserve, flush);
@@ -5294,9 +5290,6 @@ static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
         rb_erase(&head->node.rb_node, &delayed_refs->root);
 
         delayed_refs->num_entries--;
-        smp_mb();
-        if (waitqueue_active(&root->fs_info->tree_mod_seq_wait))
-                wake_up(&root->fs_info->tree_mod_seq_wait);
 
         /*
          * we don't take a ref on the node because we're removing it from the
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 45c81bb4ac82..4c878476bb91 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2330,23 +2330,10 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
                 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
                         ret = tree->ops->readpage_end_io_hook(page, start, end,
                                                               state, mirror);
-                        if (ret) {
-                                /* no IO indicated but software detected errors
-                                 * in the block, either checksum errors or
-                                 * issues with the contents */
-                                struct btrfs_root *root =
-                                        BTRFS_I(page->mapping->host)->root;
-                                struct btrfs_device *device;
-
+                        if (ret)
                                 uptodate = 0;
-                                device = btrfs_find_device_for_logical(
-                                                root, start, mirror);
-                                if (device)
-                                        btrfs_dev_stat_inc_and_print(device,
-                                                BTRFS_DEV_STAT_CORRUPTION_ERRS);
-                        } else {
+                        else
                                 clean_io_failure(start, page);
-                        }
                 }
 
                 if (!uptodate && tree->ops && tree->ops->readpage_io_failed_hook) {
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index b45b9de0c21d..857d93cd01dc 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -272,9 +272,9 @@ int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
 }
 
 int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
-                              struct bio *bio, u64 offset, u32 *dst)
+                              struct bio *bio, u64 offset)
 {
-        return __btrfs_lookup_bio_sums(root, inode, bio, offset, dst, 1);
+        return __btrfs_lookup_bio_sums(root, inode, bio, offset, NULL, 1);
 }
 
 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6e8f416773d4..ec154f954646 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1008,9 +1008,7 @@ static noinline void async_cow_submit(struct btrfs_work *work)
         nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
                 PAGE_CACHE_SHIFT;
 
-        atomic_sub(nr_pages, &root->fs_info->async_delalloc_pages);
-
-        if (atomic_read(&root->fs_info->async_delalloc_pages) <
+        if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
             5 * 1024 * 1024 &&
             waitqueue_active(&root->fs_info->async_submit_wait))
                 wake_up(&root->fs_info->async_submit_wait);
@@ -1885,8 +1883,11 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
                                 trans = btrfs_join_transaction_nolock(root);
                         else
                                 trans = btrfs_join_transaction(root);
-                        if (IS_ERR(trans))
-                                return PTR_ERR(trans);
+                        if (IS_ERR(trans)) {
+                                ret = PTR_ERR(trans);
+                                trans = NULL;
+                                goto out;
+                        }
                         trans->block_rsv = &root->fs_info->delalloc_block_rsv;
                         ret = btrfs_update_inode_fallback(trans, root, inode);
                         if (ret) /* -ENOMEM or corruption */
@@ -3174,7 +3175,7 @@ int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
         btrfs_i_size_write(dir, dir->i_size - name_len * 2);
         inode_inc_iversion(dir);
         dir->i_mtime = dir->i_ctime = CURRENT_TIME;
-        ret = btrfs_update_inode(trans, root, dir);
+        ret = btrfs_update_inode_fallback(trans, root, dir);
         if (ret)
                 btrfs_abort_transaction(trans, root, ret);
 out:
@@ -5774,18 +5775,112 @@ out:
         return ret;
 }
 
+static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
+                              struct extent_state **cached_state, int writing)
+{
+        struct btrfs_ordered_extent *ordered;
+        int ret = 0;
+
+        while (1) {
+                lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+                                 0, cached_state);
+                /*
+                 * We're concerned with the entire range that we're going to be
+                 * doing DIO to, so we need to make sure theres no ordered
+                 * extents in this range.
+                 */
+                ordered = btrfs_lookup_ordered_range(inode, lockstart,
+                                                     lockend - lockstart + 1);
+
+                /*
+                 * We need to make sure there are no buffered pages in this
+                 * range either, we could have raced between the invalidate in
+                 * generic_file_direct_write and locking the extent.  The
+                 * invalidate needs to happen so that reads after a write do not
+                 * get stale data.
+                 */
+                if (!ordered && (!writing ||
+                    !test_range_bit(&BTRFS_I(inode)->io_tree,
+                                    lockstart, lockend, EXTENT_UPTODATE, 0,
+                                    *cached_state)))
+                        break;
+
+                unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+                                     cached_state, GFP_NOFS);
+
+                if (ordered) {
+                        btrfs_start_ordered_extent(inode, ordered, 1);
+                        btrfs_put_ordered_extent(ordered);
+                } else {
+                        /* Screw you mmap */
+                        ret = filemap_write_and_wait_range(inode->i_mapping,
+                                                           lockstart,
+                                                           lockend);
+                        if (ret)
+                                break;
+
+                        /*
+                         * If we found a page that couldn't be invalidated just
+                         * fall back to buffered.
+                         */
+                        ret = invalidate_inode_pages2_range(inode->i_mapping,
+                                        lockstart >> PAGE_CACHE_SHIFT,
+                                        lockend >> PAGE_CACHE_SHIFT);
+                        if (ret)
+                                break;
+                }
+
+                cond_resched();
+        }
+
+        return ret;
+}
+
 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
                                    struct buffer_head *bh_result, int create)
 {
         struct extent_map *em;
         struct btrfs_root *root = BTRFS_I(inode)->root;
+        struct extent_state *cached_state = NULL;
         u64 start = iblock << inode->i_blkbits;
+        u64 lockstart, lockend;
         u64 len = bh_result->b_size;
         struct btrfs_trans_handle *trans;
+        int unlock_bits = EXTENT_LOCKED;
+        int ret;
+
+        if (create) {
+                ret = btrfs_delalloc_reserve_space(inode, len);
+                if (ret)
+                        return ret;
+                unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
+        } else {
+                len = min_t(u64, len, root->sectorsize);
+        }
+
+        lockstart = start;
+        lockend = start + len - 1;
+
+        /*
+         * If this errors out it's because we couldn't invalidate pagecache for
+         * this range and we need to fallback to buffered.
+         */
+        if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
+                return -ENOTBLK;
+
+        if (create) {
+                ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
+                                     lockend, EXTENT_DELALLOC, NULL,
+                                     &cached_state, GFP_NOFS);
+                if (ret)
+                        goto unlock_err;
+        }
 
         em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
-        if (IS_ERR(em))
-                return PTR_ERR(em);
+        if (IS_ERR(em)) {
+                ret = PTR_ERR(em);
+                goto unlock_err;
+        }
 
         /*
          * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
@@ -5804,17 +5899,16 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
         if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
             em->block_start == EXTENT_MAP_INLINE) {
                 free_extent_map(em);
-                return -ENOTBLK;
+                ret = -ENOTBLK;
+                goto unlock_err;
         }
 
         /* Just a good old fashioned hole, return */
         if (!create && (em->block_start == EXTENT_MAP_HOLE ||
                         test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
                 free_extent_map(em);
-                /* DIO will do one hole at a time, so just unlock a sector */
-                unlock_extent(&BTRFS_I(inode)->io_tree, start,
-                              start + root->sectorsize - 1);
-                return 0;
+                ret = 0;
+                goto unlock_err;
         }
 
         /*
@@ -5827,8 +5921,9 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
          *
          */
         if (!create) {
-                len = em->len - (start - em->start);
-                goto map;
+                len = min(len, em->len - (start - em->start));
+                lockstart = start + len;
+                goto unlock;
         }
 
         if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
@@ -5860,7 +5955,7 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
                         btrfs_end_transaction(trans, root);
                         if (ret) {
                                 free_extent_map(em);
-                                return ret;
+                                goto unlock_err;
                         }
                         goto unlock;
                 }
@@ -5873,14 +5968,12 @@ must_cow:
          */
         len = bh_result->b_size;
         em = btrfs_new_extent_direct(inode, em, start, len);
-        if (IS_ERR(em))
-                return PTR_ERR(em);
+        if (IS_ERR(em)) {
+                ret = PTR_ERR(em);
+                goto unlock_err;
+        }
         len = min(len, em->len - (start - em->start));
 unlock:
-        clear_extent_bit(&BTRFS_I(inode)->io_tree, start, start + len - 1,
-                          EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DIRTY, 1,
-                          0, NULL, GFP_NOFS);
-map:
         bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
                 inode->i_blkbits;
         bh_result->b_size = len;
@@ -5898,9 +5991,44 @@ map:
                         i_size_write(inode, start + len);
         }
 
+        /*
+         * In the case of write we need to clear and unlock the entire range,
+         * in the case of read we need to unlock only the end area that we
+         * aren't using if there is any left over space.
+         */
+        if (lockstart < lockend) {
+                if (create && len < lockend - lockstart) {
+                        clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
+                                         lockstart + len - 1, unlock_bits, 1, 0,
+                                         &cached_state, GFP_NOFS);
+                        /*
+                         * Beside unlock, we also need to cleanup reserved space
+                         * for the left range by attaching EXTENT_DO_ACCOUNTING.
+                         */
+                        clear_extent_bit(&BTRFS_I(inode)->io_tree,
+                                         lockstart + len, lockend,
+                                         unlock_bits | EXTENT_DO_ACCOUNTING,
+                                         1, 0, NULL, GFP_NOFS);
+                } else {
+                        clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
+                                         lockend, unlock_bits, 1, 0,
+                                         &cached_state, GFP_NOFS);
+                }
+        } else {
+                free_extent_state(cached_state);
+        }
+
         free_extent_map(em);
 
         return 0;
+
+unlock_err:
+        if (create)
+                unlock_bits |= EXTENT_DO_ACCOUNTING;
+
+        clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+                         unlock_bits, 1, 0, &cached_state, GFP_NOFS);
+        return ret;
 }
 
 struct btrfs_dio_private {
@@ -5908,7 +6036,6 @@ struct btrfs_dio_private {
         u64 logical_offset;
         u64 disk_bytenr;
         u64 bytes;
-        u32 *csums;
         void *private;
 
         /* number of bios pending for this dio */
@@ -5928,7 +6055,6 @@ static void btrfs_endio_direct_read(struct bio *bio, int err)
         struct inode *inode = dip->inode;
         struct btrfs_root *root = BTRFS_I(inode)->root;
         u64 start;
-        u32 *private = dip->csums;
 
         start = dip->logical_offset;
         do {
@@ -5936,8 +6062,12 @@ static void btrfs_endio_direct_read(struct bio *bio, int err)
                         struct page *page = bvec->bv_page;
                         char *kaddr;
                         u32 csum = ~(u32)0;
+                        u64 private = ~(u32)0;
                         unsigned long flags;
 
+                        if (get_state_private(&BTRFS_I(inode)->io_tree,
+                                              start, &private))
+                                goto failed;
                         local_irq_save(flags);
                         kaddr = kmap_atomic(page);
                         csum = btrfs_csum_data(root, kaddr + bvec->bv_offset,
@@ -5947,18 +6077,18 @@ static void btrfs_endio_direct_read(struct bio *bio, int err)
                         local_irq_restore(flags);
 
                         flush_dcache_page(bvec->bv_page);
-                        if (csum != *private) {
+                        if (csum != private) {
+failed:
                                 printk(KERN_ERR "btrfs csum failed ino %llu off"
                                       " %llu csum %u private %u\n",
                                       (unsigned long long)btrfs_ino(inode),
                                       (unsigned long long)start,
-                                      csum, *private);
+                                      csum, (unsigned)private);
                                 err = -EIO;
                         }
                 }
 
                 start += bvec->bv_len;
-                private++;
                 bvec++;
         } while (bvec <= bvec_end);
 
@@ -5966,7 +6096,6 @@ static void btrfs_endio_direct_read(struct bio *bio, int err)
                       dip->logical_offset + dip->bytes - 1);
         bio->bi_private = dip->private;
 
-        kfree(dip->csums);
         kfree(dip);
 
         /* If we had a csum failure make sure to clear the uptodate flag */
@@ -6072,7 +6201,7 @@ static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
 
 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
                                          int rw, u64 file_offset, int skip_sum,
-                                         u32 *csums, int async_submit)
+                                         int async_submit)
 {
         int write = rw & REQ_WRITE;
         struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -6105,8 +6234,7 @@ static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
                 if (ret)
                         goto err;
         } else if (!skip_sum) {
-                ret = btrfs_lookup_bio_sums_dio(root, inode, bio,
-                                          file_offset, csums);
+                ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset);
                 if (ret)
                         goto err;
         }
@@ -6132,10 +6260,8 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
         u64 submit_len = 0;
         u64 map_length;
         int nr_pages = 0;
-        u32 *csums = dip->csums;
         int ret = 0;
         int async_submit = 0;
-        int write = rw & REQ_WRITE;
 
         map_length = orig_bio->bi_size;
         ret = btrfs_map_block(map_tree, READ, start_sector << 9,
@@ -6171,16 +6297,13 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
                         atomic_inc(&dip->pending_bios);
                         ret = __btrfs_submit_dio_bio(bio, inode, rw,
                                                      file_offset, skip_sum,
-                                                     csums, async_submit);
+                                                     async_submit);
                         if (ret) {
                                 bio_put(bio);
                                 atomic_dec(&dip->pending_bios);
                                 goto out_err;
                         }
 
-                        /* Write's use the ordered csums */
-                        if (!write && !skip_sum)
-                                csums = csums + nr_pages;
                         start_sector += submit_len >> 9;
                         file_offset += submit_len;
 
@@ -6210,7 +6333,7 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
 
 submit:
         ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
-                                     csums, async_submit);
+                                     async_submit);
         if (!ret)
                 return 0;
 
@@ -6246,17 +6369,6 @@ static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
                 ret = -ENOMEM;
                 goto free_ordered;
         }
-        dip->csums = NULL;
-
-        /* Write's use the ordered csum stuff, so we don't need dip->csums */
-        if (!write && !skip_sum) {
-                dip->csums = kmalloc(sizeof(u32) * bio->bi_vcnt, GFP_NOFS);
-                if (!dip->csums) {
-                        kfree(dip);
-                        ret = -ENOMEM;
-                        goto free_ordered;
-                }
-        }
 
         dip->private = bio->bi_private;
         dip->inode = inode;
@@ -6341,132 +6453,22 @@ static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *io
 out:
         return retval;
 }
+
 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
                         const struct iovec *iov, loff_t offset,
                         unsigned long nr_segs)
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file->f_mapping->host;
-        struct btrfs_ordered_extent *ordered;
-        struct extent_state *cached_state = NULL;
-        u64 lockstart, lockend;
-        ssize_t ret;
-        int writing = rw & WRITE;
-        int write_bits = 0;
-        size_t count = iov_length(iov, nr_segs);
 
         if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
-                            offset, nr_segs)) {
+                            offset, nr_segs))
                 return 0;
-        }
-
-        lockstart = offset;
-        lockend = offset + count - 1;
-
-        if (writing) {
-                ret = btrfs_delalloc_reserve_space(inode, count);
-                if (ret)
-                        goto out;
-        }
-
-        while (1) {
-                lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
-                                 0, &cached_state);
-                /*
-                 * We're concerned with the entire range that we're going to be
-                 * doing DIO to, so we need to make sure theres no ordered
-                 * extents in this range.
-                 */
-                ordered = btrfs_lookup_ordered_range(inode, lockstart,
-                                                     lockend - lockstart + 1);
-
-                /*
-                 * We need to make sure there are no buffered pages in this
-                 * range either, we could have raced between the invalidate in
-                 * generic_file_direct_write and locking the extent.  The
-                 * invalidate needs to happen so that reads after a write do not
-                 * get stale data.
-                 */
-                if (!ordered && (!writing ||
-                    !test_range_bit(&BTRFS_I(inode)->io_tree,
-                                    lockstart, lockend, EXTENT_UPTODATE, 0,
-                                    cached_state)))
-                        break;
-
-                unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
-                                     &cached_state, GFP_NOFS);
-
-                if (ordered) {
-                        btrfs_start_ordered_extent(inode, ordered, 1);
-                        btrfs_put_ordered_extent(ordered);
-                } else {
-                        /* Screw you mmap */
-                        ret = filemap_write_and_wait_range(file->f_mapping,
-                                                           lockstart,
-                                                           lockend);
-                        if (ret)
-                                goto out;
-
-                        /*
-                         * If we found a page that couldn't be invalidated just
-                         * fall back to buffered.
-                         */
-                        ret = invalidate_inode_pages2_range(file->f_mapping,
-                                        lockstart >> PAGE_CACHE_SHIFT,
-                                        lockend >> PAGE_CACHE_SHIFT);
-                        if (ret) {
-                                if (ret == -EBUSY)
-                                        ret = 0;
-                                goto out;
-                        }
-                }
-
-                cond_resched();
-        }
 
-        /*
-         * we don't use btrfs_set_extent_delalloc because we don't want
-         * the dirty or uptodate bits
-         */
-        if (writing) {
-                write_bits = EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING;
-                ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
-                                     EXTENT_DELALLOC, NULL, &cached_state,
-                                     GFP_NOFS);
-                if (ret) {
-                        clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
-                                         lockend, EXTENT_LOCKED | write_bits,
-                                         1, 0, &cached_state, GFP_NOFS);
-                        goto out;
-                }
-        }
-
-        free_extent_state(cached_state);
-        cached_state = NULL;
-
-        ret = __blockdev_direct_IO(rw, iocb, inode,
+        return __blockdev_direct_IO(rw, iocb, inode,
                    BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
                    iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
                    btrfs_submit_direct, 0);
-
-        if (ret < 0 && ret != -EIOCBQUEUED) {
-                clear_extent_bit(&BTRFS_I(inode)->io_tree, offset,
-                              offset + iov_length(iov, nr_segs) - 1,
-                              EXTENT_LOCKED | write_bits, 1, 0,
-                              &cached_state, GFP_NOFS);
-        } else if (ret >= 0 && ret < iov_length(iov, nr_segs)) {
-                /*
-                 * We're falling back to buffered, unlock the section we didn't
-                 * do IO on.
-                 */
-                clear_extent_bit(&BTRFS_I(inode)->io_tree, offset + ret,
-                              offset + iov_length(iov, nr_segs) - 1,
-                              EXTENT_LOCKED | write_bits, 1, 0,
-                              &cached_state, GFP_NOFS);
-        }
-out:
-        free_extent_state(cached_state);
-        return ret;
 }
 
 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 7bb755677a22..9df50fa8a078 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -424,7 +424,7 @@ static noinline int create_subvol(struct btrfs_root *root,
         uuid_le_gen(&new_uuid);
         memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
         root_item.otime.sec = cpu_to_le64(cur_time.tv_sec);
-        root_item.otime.nsec = cpu_to_le64(cur_time.tv_nsec);
+        root_item.otime.nsec = cpu_to_le32(cur_time.tv_nsec);
         root_item.ctime = root_item.otime;
         btrfs_set_root_ctransid(&root_item, trans->transid);
         btrfs_set_root_otransid(&root_item, trans->transid);
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index a44eff074805..2a1762c66041 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -67,7 +67,7 @@ void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw)
 {
         if (eb->lock_nested) {
                 read_lock(&eb->lock);
-                if (&eb->lock_nested && current->pid == eb->lock_owner) {
+                if (eb->lock_nested && current->pid == eb->lock_owner) {
                         read_unlock(&eb->lock);
                         return;
                 }
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index bc424ae5a81a..38b42e7bc91d 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1364,13 +1364,17 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
         spin_lock(&fs_info->qgroup_lock);
 
         dstgroup = add_qgroup_rb(fs_info, objectid);
-        if (!dstgroup)
+        if (IS_ERR(dstgroup)) {
+                ret = PTR_ERR(dstgroup);
                 goto unlock;
+        }
 
         if (srcid) {
                 srcgroup = find_qgroup_rb(fs_info, srcid);
-                if (!srcgroup)
+                if (!srcgroup) {
+                        ret = -EINVAL;
                         goto unlock;
+                }
                 dstgroup->rfer = srcgroup->rfer - level_size;
                 dstgroup->rfer_cmpr = srcgroup->rfer_cmpr - level_size;
                 srcgroup->excl = level_size;
@@ -1379,8 +1383,10 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
                 qgroup_dirty(fs_info, srcgroup);
         }
 
-        if (!inherit)
+        if (!inherit) {
+                ret = -EINVAL;
                 goto unlock;
+        }
 
         i_qgroups = (u64 *)(inherit + 1);
         for (i = 0; i < inherit->num_qgroups; ++i) {
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 6bb465cca20f..10d8e4d88071 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -544,8 +544,8 @@ void btrfs_update_root_times(struct btrfs_trans_handle *trans,
         struct timespec ct = CURRENT_TIME;
 
         spin_lock(&root->root_times_lock);
-        item->ctransid = trans->transid;
+        item->ctransid = cpu_to_le64(trans->transid);
         item->ctime.sec = cpu_to_le64(ct.tv_sec);
-        item->ctime.nsec = cpu_to_le64(ct.tv_nsec);
+        item->ctime.nsec = cpu_to_le32(ct.tv_nsec);
         spin_unlock(&root->root_times_lock);
 }
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index f2eb24c477a3..83d6f9f9c220 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -838,7 +838,6 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
         struct btrfs_trans_handle *trans;
         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
         struct btrfs_root *root = fs_info->tree_root;
-        int ret;
 
         trace_btrfs_sync_fs(wait);
 
@@ -849,11 +848,17 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
 
         btrfs_wait_ordered_extents(root, 0, 0);
 
-        trans = btrfs_start_transaction(root, 0);
+        spin_lock(&fs_info->trans_lock);
+        if (!fs_info->running_transaction) {
+                spin_unlock(&fs_info->trans_lock);
+                return 0;
+        }
+        spin_unlock(&fs_info->trans_lock);
+
+        trans = btrfs_join_transaction(root);
         if (IS_ERR(trans))
                 return PTR_ERR(trans);
-        ret = btrfs_commit_transaction(trans, root);
-        return ret;
+        return btrfs_commit_transaction(trans, root);
 }
 
 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
@@ -1530,6 +1535,8 @@ static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
         while (cur_devices) {
                 head = &cur_devices->devices;
                 list_for_each_entry(dev, head, dev_list) {
+                        if (dev->missing)
+                                continue;
                         if (!first_dev || dev->devid < first_dev->devid)
                                 first_dev = dev;
                 }
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 17be3dedacba..27c26004e050 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1031,6 +1031,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 
         btrfs_i_size_write(parent_inode, parent_inode->i_size +
                                          dentry->d_name.len * 2);
+        parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
         ret = btrfs_update_inode(trans, parent_root, parent_inode);
         if (ret)
                 goto abort_trans_dput;
@@ -1066,7 +1067,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
         memcpy(new_root_item->parent_uuid, root->root_item.uuid,
                         BTRFS_UUID_SIZE);
         new_root_item->otime.sec = cpu_to_le64(cur_time.tv_sec);
-        new_root_item->otime.nsec = cpu_to_le64(cur_time.tv_nsec);
+        new_root_item->otime.nsec = cpu_to_le32(cur_time.tv_nsec);
         btrfs_set_root_otransid(new_root_item, trans->transid);
         memset(&new_root_item->stime, 0, sizeof(new_root_item->stime));
         memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime));
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e86ae04abe6a..88b969aeeb71 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -227,9 +227,8 @@ loop_lock:
                 cur = pending;
                 pending = pending->bi_next;
                 cur->bi_next = NULL;
-                atomic_dec(&fs_info->nr_async_bios);
 
-                if (atomic_read(&fs_info->nr_async_bios) < limit &&
+                if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
                     waitqueue_active(&fs_info->async_submit_wait))
                         wake_up(&fs_info->async_submit_wait);
 
@@ -569,9 +568,11 @@ static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
                 memcpy(new_device, device, sizeof(*new_device));
 
                 /* Safe because we are under uuid_mutex */
-                name = rcu_string_strdup(device->name->str, GFP_NOFS);
-                BUG_ON(device->name && !name); /* -ENOMEM */
-                rcu_assign_pointer(new_device->name, name);
+                if (device->name) {
+                        name = rcu_string_strdup(device->name->str, GFP_NOFS);
+                        BUG_ON(device->name && !name); /* -ENOMEM */
+                        rcu_assign_pointer(new_device->name, name);
+                }
                 new_device->bdev = NULL;
                 new_device->writeable = 0;
                 new_device->in_fs_metadata = 0;
@@ -4605,28 +4606,6 @@ int btrfs_read_sys_array(struct btrfs_root *root)
         return ret;
 }
 
-struct btrfs_device *btrfs_find_device_for_logical(struct btrfs_root *root,
-                                                   u64 logical, int mirror_num)
-{
-        struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
-        int ret;
-        u64 map_length = 0;
-        struct btrfs_bio *bbio = NULL;
-        struct btrfs_device *device;
-
-        BUG_ON(mirror_num == 0);
-        ret = btrfs_map_block(map_tree, WRITE, logical, &map_length, &bbio,
-                              mirror_num);
-        if (ret) {
-                BUG_ON(bbio != NULL);
-                return NULL;
-        }
-        BUG_ON(mirror_num != bbio->mirror_num);
-        device = bbio->stripes[mirror_num - 1].dev;
-        kfree(bbio);
-        return device;
-}
-
 int btrfs_read_chunk_tree(struct btrfs_root *root)
 {
         struct btrfs_path *path;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 5479325987b3..53c06af92e8d 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -289,8 +289,6 @@ int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
                          u64 *start, u64 *max_avail);
-struct btrfs_device *btrfs_find_device_for_logical(struct btrfs_root *root,
-                                                   u64 logical, int mirror_num);
 void btrfs_dev_stat_print_on_error(struct btrfs_device *device);
 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
 int btrfs_get_dev_stats(struct btrfs_root *root,