Commit a5d60783 authored Aug 30, 2016 by Mikulas Patocka Committed by Mike Snitzer Aug 30, 2016

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

parent 3eab887a

drivers/md/dm-log-writes.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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;