| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.7 112/184] dm log writes: move IO accounting earlier to fix error path | Date | Thu, 22 Sep 2016 19:40:46 +0200 |
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4.7-stable review patch. If anyone has any objections, please let me know.
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From: Mikulas Patocka <mpatocka@redhat.com>
commit a5d60783df61fbb67b7596b8a0f6b4b2e05251d5 upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/md/dm-log-writes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/md/dm-log-writes.c +++ b/drivers/md/dm-log-writes.c @@ -258,12 +258,12 @@ static int log_one_block(struct log_writ 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;
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