4.9-stable review patch. If anyone has any objections, please let me know.
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From: Filipe Manana fdmanana@suse.com
[ Upstream commit 8434ec46c6e3232cebc25a910363b29f5c617820 ]
When logging an inode, at tree-log.c:copy_items(), if we call btrfs_next_leaf() at the loop which checks for the need to log holes, we need to make sure copy_items() returns the value 1 to its caller and not 0 (on success). This is because the path the caller passed was released and is now different from what is was before, and the caller expects a return value of 0 to mean both success and that the path has not changed, while a return value of 1 means both success and signals the caller that it can not reuse the path, it has to perform another tree search.
Even though this is a case that should not be triggered on normal circumstances or very rare at least, its consequences can be very unpredictable (especially when replaying a log tree).
Fixes: 16e7549f045d ("Btrfs: incompatible format change to remove hole extents") Signed-off-by: Filipe Manana fdmanana@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/tree-log.c | 1 + 1 file changed, 1 insertion(+)
--- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -3854,6 +3854,7 @@ fill_holes: ASSERT(ret == 0); src = src_path->nodes[0]; i = 0; + need_find_last_extent = true; }
btrfs_item_key_to_cpu(src, &key, i);