btrfs: reject encoded write if inode has nodatasum flag set

commit 1bd96c92c6a0a4d43815eb685c15aa4b78879dc9 upstream.

Currently we allow an encoded write against inodes that have the NODATASUM
flag set, either because they are NOCOW files or they were created while
the filesystem was mounted with "-o nodatasum". This results in having
compressed extents without corresponding checksums, which is a filesystem
inconsistency reported by 'btrfs check'.

For example, running btrfs/281 with MOUNT_OPTIONS="-o nodatacow" triggers
this and 'btrfs check' errors out with:

   [1/7] checking root items
   [2/7] checking extents
   [3/7] checking free space tree
   [4/7] checking fs roots
   root 256 inode 257 errors 1040, bad file extent, some csum missing
   root 256 inode 258 errors 1040, bad file extent, some csum missing
   ERROR: errors found in fs roots
   (...)

So reject encoded writes if the target inode has NODATASUM set.

CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f250e2083c7eb885f32cf7206be09688d3a2ce1b..b5c058b304ebb7af67fb81e5ae95a4963fca1d8d 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10223,6 +10223,13 @@ ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
        if (encoded->encryption != BTRFS_ENCODED_IO_ENCRYPTION_NONE)
                return -EINVAL;
 
+       /*
+        * Compressed extents should always have checksums, so error out if we
+        * have a NOCOW file or inode was created while mounted with NODATASUM.
+        */
+       if (inode->flags & BTRFS_INODE_NODATASUM)
+               return -EINVAL;
+
        orig_count = iov_iter_count(from);
 
        /* The extent size must be sane. */