dm log writes: move IO accounting earlier to fix error path

Move log_one_block()'s atomic_inc(&lc->io_blocks) before bio_alloc() to
fix a bug that the target hangs if bio_alloc() fails.  The error path
does put_io_block(lc), so atomic_inc(&lc->io_blocks) must occur before
invoking the error path to avoid underflow of lc->io_blocks.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Josef Bacik <jbacik@fb,com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
This commit is contained in:
Mikulas Patocka 2016-08-30 16:11:53 -04:00 committed by Mike Snitzer
parent 3eab887a55
commit a5d60783df

View File

@ -259,12 +259,12 @@ static int log_one_block(struct log_writes_c *lc,
goto out;
sector++;
atomic_inc(&lc->io_blocks);
bio = bio_alloc(GFP_KERNEL, block->vec_cnt);
if (!bio) {
DMERR("Couldn't alloc log bio");
goto error;
}
atomic_inc(&lc->io_blocks);
bio->bi_iter.bi_size = 0;
bio->bi_iter.bi_sector = sector;
bio->bi_bdev = lc->logdev->bdev;