From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mikulas Patocka , Josef Bacik , Mike Snitzer 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 Message-Id: <20160922174053.540276193@linuxfoundation.org> In-Reply-To: <20160922174048.653794923@linuxfoundation.org> References: <20160922174048.653794923@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mikulas Patocka 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 Reviewed-by: Josef Bacik Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- 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;