3.19.8-ckt12 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Junichi Nomura <[email protected]> commit 5bbbfdf685657771fda05b926b28ca0f79163a28 upstream. 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 <[email protected]> Cc: Hannes Reinecke <[email protected]> Cc: Mikulas Patocka <[email protected]> Signed-off-by: Mike Snitzer <[email protected]> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <[email protected]> Signed-off-by: Kamal Mostafa <[email protected]> --- drivers/md/dm-mpath.c | 2 +- drivers/md/dm.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 7ed0e7b..35cbc2a 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -1548,7 +1548,7 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd, if (!r && ti->len != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT) r = scsi_verify_blk_ioctl(NULL, cmd); - if (r == -ENOTCONN && !fatal_signal_pending(current)) { + if (r == -ENOTCONN) { spin_lock_irqsave(&m->lock, flags); if (!m->current_pg) { /* Path status changed, redo selection */ diff --git a/drivers/md/dm.c b/drivers/md/dm.c index df81bbd..b93f32d 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -543,7 +543,7 @@ retry: out: dm_put_live_table(md, srcu_idx); - if (r == -ENOTCONN) { + if (r == -ENOTCONN && !fatal_signal_pending(current)) { msleep(10); goto retry; } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
