btrfs: fix unexpected error path when reflinking an inline extent

When reflinking an inline extent, we assert that its file offset is 0 and
that its uncompressed length is not greater than the sector size. We then
return an error if one of those conditions is not satisfied. However we
use a return statement, which results in returning from btrfs_clone()
without freeing the path and buffer that were allocated before, as well as
not clearing the flag BTRFS_INODE_NO_DELALLOC_FLUSH for the destination
inode.

Fix that by jumping to the 'out' label instead, and also add a WARN_ON()
for each condition so that in case assertions are disabled, we get to
known which of the unexpected conditions triggered the error.

Fixes: 983301cb8a6b2e ("Btrfs: simplify inline extent handling when doing reflinks")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c
index cdcfeab82e123f7e051a7c753e16215df378c22c..07e19e069c84c8914d07bb82489960a99dde2665 100644 (file)
--- a/fs/btrfs/reflink.c
+++ b/fs/btrfs/reflink.c
@@ -505,8 +505,11 @@ process_slot:
                         */
                        ASSERT(key.offset == 0);
                        ASSERT(datal <= fs_info->sectorsize);
-                       if (key.offset != 0 || datal > fs_info->sectorsize)
-                               return -EUCLEAN;
+                       if (WARN_ON(key.offset != 0) ||
+                           WARN_ON(datal > fs_info->sectorsize)) {
+                               ret = -EUCLEAN;
+                               goto out;
+                       }
 
                        ret = clone_copy_inline_extent(inode, path, &new_key,
                                                       drop_start, datal, size,