Patch "btrfs: make search_csum_tree return 0 if we get -EFBIG" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    btrfs: make search_csum_tree return 0 if we get -EFBIG

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     btrfs-make-search_csum_tree-return-0-if-we-get-efbig.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 57a9aa844e01d9e5ff247d92e2d96c0e81824dfd
Author: Josef Bacik <josef@xxxxxxxxxxxxxx>
Date:   Fri Feb 18 10:03:22 2022 -0500

    btrfs: make search_csum_tree return 0 if we get -EFBIG
    
    [ Upstream commit 03ddb19d2ea745228879b9334f3b550c88acb10a ]
    
    We can either fail to find a csum entry at all and return -ENOENT, or we
    can find a range that is close, but return -EFBIG.  In essence these
    both mean the same thing when we are doing a lookup for a csum in an
    existing range, we didn't find a csum.  We want to treat both of these
    errors the same way, complain loudly that there wasn't a csum.  This
    currently happens anyway because we do
    
            count = search_csum_tree();
            if (count <= 0) {
                    // reloc and error handling
            }
    
    However it forces us to incorrectly treat EIO or ENOMEM errors as on
    disk corruption.  Fix this by returning 0 if we get either -ENOENT or
    -EFBIG from btrfs_lookup_csum() so we can do proper error handling.
    
    Reviewed-by: Boris Burkov <boris@xxxxxx>
    Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
    Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
    Reviewed-by: David Sterba <dsterba@xxxxxxxx>
    Signed-off-by: David Sterba <dsterba@xxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 0b9401a5afd3..161a69d7e117 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -303,7 +303,7 @@ static int search_csum_tree(struct btrfs_fs_info *fs_info,
 	read_extent_buffer(path->nodes[0], dst, (unsigned long)item,
 			ret * csum_size);
 out:
-	if (ret == -ENOENT)
+	if (ret == -ENOENT || ret == -EFBIG)
 		ret = 0;
 	return ret;
 }