diff options
| author | Ming Lei <ming.lei@canonical.com> | 2016-04-15 18:51:28 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2016-04-15 08:25:56 -0600 |
| commit | a7297a6a3a3322b054592e8e988981d2f5f29cc4 (patch) | |
| tree | 04064ecd0b492d492617443ebf7c73baa66ec951 | |
| parent | a5229050b69cfffb690b546c357ca5a60434c0c8 (diff) | |
| download | linux-a7297a6a3a3322b054592e8e988981d2f5f29cc4.tar.bz2 | |
block: loop: fix filesystem corruption in case of aio/dio
Starting from commit e36f620428(block: split bios to max possible length),
block core starts to split bio in the middle of bvec.
Unfortunately loop dio/aio doesn't consider this situation, and
always treat 'iter.iov_offset' as zero. Then filesystem corruption
is observed.
This patch figures out the offset of the base bvevc via
'bio->bi_iter.bi_bvec_done' and fixes the issue by passing the offset
to iov iterator.
Fixes: e36f6204288088f (block: split bios to max possible length)
Cc: Keith Busch <keith.busch@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org (4.5)
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
| -rw-r--r-- | drivers/block/loop.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 423f4ca7d712..80cf8add46ff 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -488,6 +488,12 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter); iov_iter_bvec(&iter, ITER_BVEC | rw, bvec, bio_segments(bio), blk_rq_bytes(cmd->rq)); + /* + * This bio may be started from the middle of the 'bvec' + * because of bio splitting, so offset from the bvec must + * be passed to iov iterator + */ + iter.iov_offset = bio->bi_iter.bi_bvec_done; cmd->iocb.ki_pos = pos; cmd->iocb.ki_filp = file; |