[PATCH v2 1/2] Btrfs: add missing error handling after doing leaf/node binary search

[fdmanana@kernel.org]

From: Filipe Manana <fdmanana@suse.com>

The function map_private_extent_buffer() can return an -EINVAL error, and
it is called by generic_bin_search() which will return back the error. The
btrfs_bin_search() function in turn calls generic_bin_search() and the
key_search() function calls btrfs_bin_search(), so both can return the
-EINVAL error coming from the map_private_extent_buffer() function. Some
callers of these functions were ignoring that these functions can return
an error, so fix them to deal with error return values.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---

V2: Fixed error handling in relocation, missed assignment of ret to err.

 fs/btrfs/ctree.c      |  6 ++++++
 fs/btrfs/relocation.c | 10 ++++++++++
 fs/btrfs/tree-log.c   |  2 ++
 3 files changed, 18 insertions(+)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 5a6c39b44c84..5b9f602fb9e2 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -3005,6 +3005,8 @@ int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
 		 */
 		prev_cmp = -1;
 		ret = key_search(b, key, level, &prev_cmp, &slot);
+		if (ret < 0)
+			goto done;
 
 		if (level != 0) {
 			int dec = 0;
@@ -5156,6 +5158,10 @@ int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
 		nritems = btrfs_header_nritems(cur);
 		level = btrfs_header_level(cur);
 		sret = btrfs_bin_search(cur, min_key, level, &slot);
+		if (sret < 0) {
+			ret = sret;
+			goto out;
+		}
 
 		/* at the lowest level, we're done, setup the path and exit */
 		if (level == path->lowest_level) {
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 272b287f8cf0..628ba528516d 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -1802,6 +1802,8 @@ int replace_path(struct btrfs_trans_handle *trans, struct reloc_control *rc,
 		BUG_ON(level < lowest_level);
 
 		ret = btrfs_bin_search(parent, &key, level, &slot);
+		if (ret < 0)
+			break;
 		if (ret && slot > 0)
 			slot--;
 
@@ -2685,6 +2687,10 @@ static int do_relocation(struct btrfs_trans_handle *trans,
 			if (!lowest) {
 				ret = btrfs_bin_search(upper->eb, key,
 						       upper->level, &slot);
+				if (ret < 0) {
+					err = ret;
+					goto next;
+				}
 				BUG_ON(ret);
 				bytenr = btrfs_node_blockptr(upper->eb, slot);
 				if (node->eb->start == bytenr)
@@ -2720,6 +2726,10 @@ static int do_relocation(struct btrfs_trans_handle *trans,
 		} else {
 			ret = btrfs_bin_search(upper->eb, key, upper->level,
 					       &slot);
+			if (ret < 0) {
+				err = ret;
+				goto next;
+			}
 			BUG_ON(ret);
 		}
 
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 8c9e87f5ec58..81a357a32837 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3772,6 +3772,8 @@ static int drop_objectid_items(struct btrfs_trans_handle *trans,
 		found_key.type = 0;
 		ret = btrfs_bin_search(path->nodes[0], &found_key, 0,
 				       &start_slot);
+		if (ret < 0)
+			break;
 
 		ret = btrfs_del_items(trans, log, path, start_slot,
 				      path->slots[0] - start_slot + 1);
-- 
2.11.0