From: Christoph Hellwig hch@lst.de
commit 68d99ab0e9221ef54506f827576c5a914680eeaf upstream.
The BTRFS_FS_CSUM_IMPL_FAST flag is currently set whenever a non-generic crc32c is detected, which is the incorrect check if the file system uses a different checksumming algorithm. Refactor the code to only check this if crc32c is actually used. Note that in an ideal world the information if an algorithm is hardware accelerated or not should be provided by the crypto API instead, but that's left for another day.
CC: stable@vger.kernel.org # 5.4.x: c8a5f8ca9a9c: btrfs: print checksum type and implementation at mount time CC: stable@vger.kernel.org # 5.4.x Signed-off-by: Christoph Hellwig hch@lst.de Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/disk-io.c | 14 ++++++++++++++ fs/btrfs/super.c | 2 -- 2 files changed, 14 insertions(+), 2 deletions(-)
--- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2318,6 +2318,20 @@ static int btrfs_init_csum_hash(struct b
fs_info->csum_shash = csum_shash;
+ /* + * Check if the checksum implementation is a fast accelerated one. + * As-is this is a bit of a hack and should be replaced once the csum + * implementations provide that information themselves. + */ + switch (csum_type) { + case BTRFS_CSUM_TYPE_CRC32: + if (!strstr(crypto_shash_driver_name(csum_shash), "generic")) + set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags); + break; + default: + break; + } + btrfs_info(fs_info, "using %s (%s) checksum algorithm", btrfs_super_csum_name(csum_type), crypto_shash_driver_name(csum_shash)); --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1749,8 +1749,6 @@ static struct dentry *btrfs_mount_root(s } else { snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev); btrfs_sb(s)->bdev_holder = fs_type; - if (!strstr(crc32c_impl(), "generic")) - set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags); error = btrfs_fill_super(s, fs_devices, data); } if (!error)