Re: [PATCH] btrfs: reject encoded write if inode has nodatasum flag set

[David Sterba <dsterba@suse.cz>]

On Fri, Feb 02, 2024 at 12:22:53PM +0000, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> 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.
> 
> Signed-off-by: Filipe Manana <fdmanana@suse.com>

Reviewed-by: David Sterba <dsterba@suse.com>