From 5bbbfdf685657771fda05b926b28ca0f79163a28 Mon Sep 17 00:00:00 2001 From: Junichi Nomura Date: Tue, 17 Nov 2015 09:39:26 +0000 Subject: dm: fix ioctl retry termination with signal dm-mpath retries ioctl, when no path is readily available and the device is configured to queue I/O in such a case. If you want to stop the retry before multipathd decides to turn off queueing mode, you could send signal for the process to exit from the loop. However the check of fatal signal has not carried along when commit 6c182cd88d17 ("dm mpath: fix ioctl deadlock when no paths") moved the loop from dm-mpath to dm core. As a result, we can't terminate such a process in the retry loop. Easy reproducer of the situation is: # dmsetup create mp --table '0 1024 multipath 0 0 0 0' # dmsetup message mp 0 'queue_if_no_path' # sg_inq /dev/mapper/mp then you should be able to terminate sg_inq by pressing Ctrl+C. Fixes: 6c182cd88d17 ("dm mpath: fix ioctl deadlock when no paths") Signed-off-by: Jun'ichi Nomura Cc: Hannes Reinecke Cc: Mikulas Patocka Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org --- drivers/md/dm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/md/dm.c') diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 6e15f3565892..fabd5d8fd559 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -591,7 +591,7 @@ retry: out: dm_put_live_table(md, *srcu_idx); - if (r == -ENOTCONN) { + if (r == -ENOTCONN && !fatal_signal_pending(current)) { msleep(10); goto retry; } -- cgit v1.2.3 From 647a20d5cad7477033bc021ec9dd75edf4bbf9a0 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Tue, 17 Nov 2015 14:11:34 -0500 Subject: dm: do not reuse dm_blk_ioctl block_device input as local variable (Ab)using the @bdev passed to dm_blk_ioctl() opens the potential for targets' .prepare_ioctl to fail if they go on to check the bdev for !NULL. Fixes: e56f81e0b01e ("dm: refactor ioctl handling") Reported-by: Junichi Nomura Signed-off-by: Mike Snitzer --- drivers/md/dm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/md/dm.c') diff --git a/drivers/md/dm.c b/drivers/md/dm.c index fabd5d8fd559..5df40480228b 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -603,9 +603,10 @@ static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode, { struct mapped_device *md = bdev->bd_disk->private_data; struct dm_target *tgt; + struct block_device *tgt_bdev = NULL; int srcu_idx, r; - r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx); + r = dm_get_live_table_for_ioctl(md, &tgt, &tgt_bdev, &mode, &srcu_idx); if (r < 0) return r; @@ -620,7 +621,7 @@ static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode, goto out; } - r = __blkdev_driver_ioctl(bdev, mode, cmd, arg); + r = __blkdev_driver_ioctl(tgt_bdev, mode, cmd, arg); out: dm_put_live_table(md, srcu_idx); return r; -- cgit v1.2.3