From: Jaegeuk Kim jaegeuk@google.com
commit 8ca7cab82bda4eb0b8064befeeeaa38106cac637 upstream.
commit df7b59ba9245 ("dm verity: fix FEC for RS roots unaligned to block size") introduced the possibility for misaligned roots IO relative to the underlying device's logical block size. E.g. Android's default RS roots=2 results in dm_bufio->block_size=1024, which causes the following EIO if the logical block size of the device is 4096, given v->data_dev_block_bits=12:
E sd 0 : 0:0:0: [sda] tag#30 request not aligned to the logical block size E blk_update_request: I/O error, dev sda, sector 10368424 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 E device-mapper: verity-fec: 254:8: FEC 9244672: parity read failed (block 18056): -5
Fix this by onlu using f->roots for dm_bufio blocksize IFF it is aligned to v->data_dev_block_bits.
Fixes: df7b59ba9245 ("dm verity: fix FEC for RS roots unaligned to block size") Cc: stable@vger.kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@google.com Signed-off-by: Mike Snitzer snitzer@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/dm-verity-fec.c | 11 ++++++++--- drivers/md/dm-verity-fec.h | 1 + 2 files changed, 9 insertions(+), 3 deletions(-)
--- a/drivers/md/dm-verity-fec.c +++ b/drivers/md/dm-verity-fec.c @@ -65,7 +65,7 @@ static u8 *fec_read_parity(struct dm_ver u8 *res;
position = (index + rsb) * v->fec->roots; - block = div64_u64_rem(position, v->fec->roots << SECTOR_SHIFT, &rem); + block = div64_u64_rem(position, v->fec->io_size, &rem); *offset = (unsigned)rem;
res = dm_bufio_read(v->fec->bufio, block, buf); @@ -154,7 +154,7 @@ static int fec_decode_bufs(struct dm_ver
/* read the next block when we run out of parity bytes */ offset += v->fec->roots; - if (offset >= v->fec->roots << SECTOR_SHIFT) { + if (offset >= v->fec->io_size) { dm_bufio_release(buf);
par = fec_read_parity(v, rsb, block_offset, &offset, &buf); @@ -742,8 +742,13 @@ int verity_fec_ctr(struct dm_verity *v) return -E2BIG; }
+ if ((f->roots << SECTOR_SHIFT) & ((1 << v->data_dev_block_bits) - 1)) + f->io_size = 1 << v->data_dev_block_bits; + else + f->io_size = v->fec->roots << SECTOR_SHIFT; + f->bufio = dm_bufio_client_create(f->dev->bdev, - f->roots << SECTOR_SHIFT, + f->io_size, 1, 0, NULL, NULL); if (IS_ERR(f->bufio)) { ti->error = "Cannot initialize FEC bufio client"; --- a/drivers/md/dm-verity-fec.h +++ b/drivers/md/dm-verity-fec.h @@ -36,6 +36,7 @@ struct dm_verity_fec { struct dm_dev *dev; /* parity data device */ struct dm_bufio_client *data_bufio; /* for data dev access */ struct dm_bufio_client *bufio; /* for parity data access */ + size_t io_size; /* IO size for roots */ sector_t start; /* parity data start in blocks */ sector_t blocks; /* number of blocks covered */ sector_t rounds; /* number of interleaving rounds */