Commit 67b9d76f authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'dm-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm 

Pull device mapper fixes from Mike Snitzer:

 - Fix DM multipath IO hang regression from 3.15 due to logic bug in
   multipath_busy.  This impacted cable-pull testing and also the
   ability to boot with IPR SCSI on a POWER8 box.

 - Fix possible deadlock with deferred device removal by using a new
   dedicated workqueue rather than using the system workqueue.

 - Fix NULL pointer crash due to race condition in dm-io's wake up code
   for sync_io by using a completion.

 - Update dm-crypt and dm-zero author name following legal name change;
   this is important to Jana so I didn't see any reason to hold it back.

* tag 'dm-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm mpath: fix IO hang due to logic bug in multipath_busy
  dm io: fix a race condition in the wake up code for sync_io
  dm crypt, dm zero: update author name following legal name change
  dm: allocate a special workqueue for deferred device removal
parents c7c3ae25 7a7a3b45

drivers/md/dm-crypt.c

+2 −2
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2003 Christophe Saout <christophe@saout.de>

 * Copyright (C) 2003 Jana Saout <jana@saout.de>

 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>

 * Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved.

 * Copyright (C) 2013 Milan Broz <gmazyland@gmail.com>
@@ -1996,6 +1996,6 @@ static void __exit dm_crypt_exit(void) 
module_init(dm_crypt_init);

module_exit(dm_crypt_exit);



MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");

MODULE_AUTHOR("Jana Saout <jana@saout.de>");

MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");

MODULE_LICENSE("GPL");

drivers/md/dm-io.c

+8 −14
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <linux/device-mapper.h>



#include <linux/bio.h>

#include <linux/completion.h>

#include <linux/mempool.h>

#include <linux/module.h>

#include <linux/sched.h>
@@ -32,7 +33,7 @@ struct dm_io_client { 
struct io {

	unsigned long error_bits;

	atomic_t count;

	struct task_struct *sleeper;

	struct completion *wait;

	struct dm_io_client *client;

	io_notify_fn callback;

	void *context;
@@ -121,8 +122,8 @@ static void dec_count(struct io *io, unsigned int region, int error) 
			invalidate_kernel_vmap_range(io->vma_invalidate_address,

						     io->vma_invalidate_size);



		if (io->sleeper)

			wake_up_process(io->sleeper);

		if (io->wait)

			complete(io->wait);



		else {

			unsigned long r = io->error_bits;
@@ -387,6 +388,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, 
	 */

	volatile char io_[sizeof(struct io) + __alignof__(struct io) - 1];

	struct io *io = (struct io *)PTR_ALIGN(&io_, __alignof__(struct io));

	DECLARE_COMPLETION_ONSTACK(wait);



	if (num_regions > 1 && (rw & RW_MASK) != WRITE) {

		WARN_ON(1);
@@ -395,7 +397,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, 


	io->error_bits = 0;

	atomic_set(&io->count, 1); /* see dispatch_io() */

	io->sleeper = current;

	io->wait = &wait;

	io->client = client;



	io->vma_invalidate_address = dp->vma_invalidate_address;
@@ -403,15 +405,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, 


	dispatch_io(rw, num_regions, where, dp, io, 1);



	while (1) {

		set_current_state(TASK_UNINTERRUPTIBLE);



		if (!atomic_read(&io->count))

			break;



		io_schedule();

	}

	set_current_state(TASK_RUNNING);

	wait_for_completion_io(&wait);



	if (error_bits)

		*error_bits = io->error_bits;
@@ -434,7 +428,7 @@ static int async_io(struct dm_io_client *client, unsigned int num_regions, 
	io = mempool_alloc(client->pool, GFP_NOIO);

	io->error_bits = 0;

	atomic_set(&io->count, 1); /* see dispatch_io() */

	io->sleeper = NULL;

	io->wait = NULL;

	io->client = client;

	io->callback = fn;

	io->context = context;

drivers/md/dm-mpath.c

+3 −2
Original line number Diff line number Diff line
@@ -1611,8 +1611,9 @@ static int multipath_busy(struct dm_target *ti) 


	spin_lock_irqsave(&m->lock, flags);



	/* pg_init in progress, requeue until done */

	if (!pg_ready(m)) {

	/* pg_init in progress or no paths available */

	if (m->pg_init_in_progress ||

	    (!m->nr_valid_paths && m->queue_if_no_path)) {

		busy = 1;

		goto out;

	}

drivers/md/dm-zero.c

+2 −2
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2003 Christophe Saout <christophe@saout.de>

 * Copyright (C) 2003 Jana Saout <jana@saout.de>

 *

 * This file is released under the GPL.

 */
@@ -79,6 +79,6 @@ static void __exit dm_zero_exit(void) 
module_init(dm_zero_init)

module_exit(dm_zero_exit)



MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");

MODULE_AUTHOR("Jana Saout <jana@saout.de>");

MODULE_DESCRIPTION(DM_NAME " dummy target returning zeros");

MODULE_LICENSE("GPL");

drivers/md/dm.c

+13 −2
Original line number Diff line number Diff line
@@ -54,6 +54,8 @@ static void do_deferred_remove(struct work_struct *w); 


static DECLARE_WORK(deferred_remove_work, do_deferred_remove);



static struct workqueue_struct *deferred_remove_workqueue;



/*

 * For bio-based dm.

 * One of these is allocated per bio.
@@ -276,16 +278,24 @@ static int __init local_init(void) 
	if (r)

		goto out_free_rq_tio_cache;



	deferred_remove_workqueue = alloc_workqueue("kdmremove", WQ_UNBOUND, 1);

	if (!deferred_remove_workqueue) {

		r = -ENOMEM;

		goto out_uevent_exit;

	}



	_major = major;

	r = register_blkdev(_major, _name);

	if (r < 0)

		goto out_uevent_exit;

		goto out_free_workqueue;



	if (!_major)

		_major = r;



	return 0;



out_free_workqueue:

	destroy_workqueue(deferred_remove_workqueue);

out_uevent_exit:

	dm_uevent_exit();

out_free_rq_tio_cache:
@@ -299,6 +309,7 @@ out_free_io_cache: 
static void local_exit(void)

{

	flush_scheduled_work();

	destroy_workqueue(deferred_remove_workqueue);



	kmem_cache_destroy(_rq_tio_cache);

	kmem_cache_destroy(_io_cache);
@@ -407,7 +418,7 @@ static void dm_blk_close(struct gendisk *disk, fmode_t mode) 


	if (atomic_dec_and_test(&md->open_count) &&

	    (test_bit(DMF_DEFERRED_REMOVE, &md->flags)))

		schedule_work(&deferred_remove_work);

		queue_work(deferred_remove_workqueue, &deferred_remove_work);



	dm_put(md);

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