Btrfs: fix up read_tree_block to return proper error
The return value of read_tree_block() can confuse callers as it always
returns NULL for either -ENOMEM or -EIO, so it's likely that callers
parse it to a wrong error, for instance, in btrfs_read_tree_root().
This fixes the above issue.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 076fd74..f1d1216 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -7979,9 +7979,12 @@
child_gen = btrfs_node_ptr_generation(eb, parent_slot);
eb = read_tree_block(root, child_bytenr, child_gen);
- if (!eb || !extent_buffer_uptodate(eb)) {
- ret = -EIO;
+ if (IS_ERR(eb)) {
+ ret = PTR_ERR(eb);
+ goto out;
+ } else if (!extent_buffer_uptodate(eb)) {
free_extent_buffer(eb);
+ ret = -EIO;
goto out;
}
@@ -8211,7 +8214,9 @@
if (reada && level == 1)
reada_walk_down(trans, root, wc, path);
next = read_tree_block(root, bytenr, generation);
- if (!next || !extent_buffer_uptodate(next)) {
+ if (IS_ERR(next)) {
+ return PTR_ERR(next);
+ } else if (!extent_buffer_uptodate(next)) {
free_extent_buffer(next);
return -EIO;
}