Merge branch 'for-chris-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.10

Patches queued up by Filipe:

The most important change is still the fix for the extent tree
corruption that happens due to balance when qgroups are enabled (a
regression introduced in 4.7 by a fix for a regression from the last
qgroups rework). This has been hitting SLE and openSUSE users and QA
very badly, where transactions keep getting aborted when running
delayed references leaving the root filesystem in RO mode and nearly
unusable.  There are fixes here that allow us to run xfstests again
with the integrity checker enabled, which has been impossible since 4.8
(apparently I'm the only one running xfstests with the integrity
checker enabled, which is useful to validate dirtied leafs, like
checking if there are keys out of order, etc).  The rest are just some
trivial fixes, most of them tagged for stable, and two cleanups.

Signed-off-by: Chris Mason <clm@fb.com>

1 files changed, 19 insertions, 4 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 848d5e1c0585..066d9b929a0c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -560,7 +560,15 @@ static noinline int check_leaf(struct btrfs_root *root,
 	u32 nritems = btrfs_header_nritems(leaf);
 	int slot;
 
-	if (nritems == 0) {
+	/*
+	 * Extent buffers from a relocation tree have a owner field that
+	 * corresponds to the subvolume tree they are based on. So just from an
+	 * extent buffer alone we can not find out what is the id of the
+	 * corresponding subvolume tree, so we can not figure out if the extent
+	 * buffer corresponds to the root of the relocation tree or not. So skip
+	 * this check for relocation trees.
+	 */
+	if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) {
 		struct btrfs_root *check_root;
 
 		key.objectid = btrfs_header_owner(leaf);
@@ -573,17 +581,24 @@ static noinline int check_leaf(struct btrfs_root *root,
 		 * open_ctree() some roots has not yet been set up.
 		 */
 		if (!IS_ERR_OR_NULL(check_root)) {
+			struct extent_buffer *eb;
+
+			eb = btrfs_root_node(check_root);
 			/* if leaf is the root, then it's fine */
-			if (leaf->start !=
-			    btrfs_root_bytenr(&check_root->root_item)) {
+			if (leaf != eb) {
 				CORRUPT("non-root leaf's nritems is 0",
-					leaf, root, 0);
+					leaf, check_root, 0);
+				free_extent_buffer(eb);
 				return -EIO;
 			}
+			free_extent_buffer(eb);
 		}
 		return 0;
 	}
 
+	if (nritems == 0)
+		return 0;
+
 	/* Check the 0 item */
 	if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
 	    BTRFS_LEAF_DATA_SIZE(fs_info)) {