Merge branch 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs updates from Chris Mason:
 "Outside of our usual batch of fixes, this integrates the subvolume
  quota updates that Qu Wenruo from Fujitsu has been working on for a
  few releases now.  He gets an extra gold star for making btrfs smaller
  this time, and fixing a number of quota corners in the process.

  Dave Sterba tested and integrated Anand Jain's sysfs improvements.
  Outside of exporting a symbol (ack'd by Greg) these are all internal
  to btrfs and it's mostly cleanups and fixes.  Anand also attached some
  of our sysfs objects to our internal device management structs instead
  of an object off the super block.  It will make device management
  easier overall and it's a better fit for how the sysfs files are used.
  None of the existing sysfs files are moved around.

  Thanks for all the fixes everyone"

* 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (87 commits)
  btrfs: delayed-ref: double free in btrfs_add_delayed_tree_ref()
  Btrfs: Check if kobject is initialized before put
  lib: export symbol kobject_move()
  Btrfs: sysfs: add support to show replacing target in the sysfs
  Btrfs: free the stale device
  Btrfs: use received_uuid of parent during send
  Btrfs: fix use-after-free in btrfs_replay_log
  btrfs: wait for delayed iputs on no space
  btrfs: qgroup: Make snapshot accounting work with new extent-oriented qgroup.
  btrfs: qgroup: Add the ability to skip given qgroup for old/new_roots.
  btrfs: ulist: Add ulist_del() function.
  btrfs: qgroup: Cleanup the old ref_node-oriented mechanism.
  btrfs: qgroup: Switch self test to extent-oriented qgroup mechanism.
  btrfs: qgroup: Switch to new extent-oriented qgroup mechanism.
  btrfs: qgroup: Switch rescan to new mechanism.
  btrfs: qgroup: Add new qgroup calculation function btrfs_qgroup_account_extents().
  btrfs: backref: Add special time_seq == (u64)-1 case for btrfs_find_all_roots().
  btrfs: qgroup: Add new function to record old_roots.
  btrfs: qgroup: Record possible quota-related extent for qgroup.
  btrfs: qgroup: Add function qgroup_update_counters().
  ...

1 files changed, 10 insertions, 6 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 0f11ebc92f02..54114b4887dd 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1439,8 +1439,9 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
 		btrfs_tree_read_unlock(eb_root);
 		free_extent_buffer(eb_root);
 		old = read_tree_block(root, logical, 0);
-		if (WARN_ON(!old || !extent_buffer_uptodate(old))) {
-			free_extent_buffer(old);
+		if (WARN_ON(IS_ERR(old) || !extent_buffer_uptodate(old))) {
+			if (!IS_ERR(old))
+				free_extent_buffer(old);
 			btrfs_warn(root->fs_info,
 				"failed to read tree block %llu from get_old_root", logical);
 		} else {
@@ -1685,7 +1686,9 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
 		if (!cur || !uptodate) {
 			if (!cur) {
 				cur = read_tree_block(root, blocknr, gen);
-				if (!cur || !extent_buffer_uptodate(cur)) {
+				if (IS_ERR(cur)) {
+					return PTR_ERR(cur);
+				} else if (!extent_buffer_uptodate(cur)) {
 					free_extent_buffer(cur);
 					return -EIO;
 				}
@@ -1864,8 +1867,9 @@ static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root,
 
 	eb = read_tree_block(root, btrfs_node_blockptr(parent, slot),
 			     btrfs_node_ptr_generation(parent, slot));
-	if (eb && !extent_buffer_uptodate(eb)) {
-		free_extent_buffer(eb);
+	if (IS_ERR(eb) || !extent_buffer_uptodate(eb)) {
+		if (!IS_ERR(eb))
+			free_extent_buffer(eb);
 		eb = NULL;
 	}
 
@@ -2494,7 +2498,7 @@ read_block_for_search(struct btrfs_trans_handle *trans,
 
 	ret = -EAGAIN;
 	tmp = read_tree_block(root, blocknr, 0);
-	if (tmp) {
+	if (!IS_ERR(tmp)) {
 		/*
 		 * If the read above didn't mark this buffer up to date,
 		 * it will never end up being up to date.  Set ret to EIO now