Commit 04445556 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'dm-4.3-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm 

Pull dm fixes from Mike Snitzer:
 "Three stable fixes:

   - DM core AB-BA deadlock fix in the device destruction path (vs
     device creation's DM table swap).

   - DM raid fix to properly round up the region_size to the next
     power-of-2.

   - DM cache fix for a NULL pointer seen while switching from the
     "cleaner" cache policy.

  Two fixes for regressions introduced during the 4.3 merge:

   - request-based DM error propagation regressed due to incorrect
     changes introduced when adding the bi_error field to bio.

   - DM snapshot fix to only support snapshots that overflow if the
     client (e.g. lvm2) is prepared to deal with the associated
     snapshot status interface change"

* tag 'dm-4.3-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm snapshot: add new persistent store option to support overflow
  dm cache: fix NULL pointer when switching from cleaner policy
  dm: fix request-based dm error reporting
  dm raid: fix round up of default region size
  dm: fix AB-BA deadlock in __dm_destroy()
parents 175d58cf b0d3cc01

Documentation/device-mapper/snapshot.txt

+7 −3
Original line number Diff line number Diff line
@@ -41,9 +41,13 @@ useless and be disabled, returning errors. So it is important to monitor 
the amount of free space and expand the <COW device> before it fills up.



<persistent?> is P (Persistent) or N (Not persistent - will not survive

after reboot).

The difference is that for transient snapshots less metadata must be

saved on disk - they can be kept in memory by the kernel.

after reboot).  O (Overflow) can be added as a persistent store option

to allow userspace to advertise its support for seeing "Overflow" in the

snapshot status.  So supported store types are "P", "PO" and "N".



The difference between persistent and transient is with transient

snapshots less metadata must be saved on disk - they can be kept in

memory by the kernel.





* snapshot-merge <origin> <COW device> <persistent> <chunksize>

drivers/md/dm-cache-policy-cleaner.c

+1 −1
Original line number Diff line number Diff line
@@ -436,7 +436,7 @@ static struct dm_cache_policy *wb_create(dm_cblock_t cache_size, 
static struct dm_cache_policy_type wb_policy_type = {

	.name = "cleaner",

	.version = {1, 0, 0},

	.hint_size = 0,

	.hint_size = 4,

	.owner = THIS_MODULE,

	.create = wb_create

};

drivers/md/dm-exception-store.c

+3 −3
Original line number Diff line number Diff line
@@ -203,7 +203,7 @@ int dm_exception_store_create(struct dm_target *ti, int argc, char **argv, 
		return -EINVAL;

	}



	tmp_store = kmalloc(sizeof(*tmp_store), GFP_KERNEL);

	tmp_store = kzalloc(sizeof(*tmp_store), GFP_KERNEL);

	if (!tmp_store) {

		ti->error = "Exception store allocation failed";

		return -ENOMEM;
@@ -215,7 +215,7 @@ int dm_exception_store_create(struct dm_target *ti, int argc, char **argv, 
	else if (persistent == 'N')

		type = get_type("N");

	else {

		ti->error = "Persistent flag is not P or N";

		ti->error = "Exception store type is not P or N";

		r = -EINVAL;

		goto bad_type;

	}
@@ -233,7 +233,7 @@ int dm_exception_store_create(struct dm_target *ti, int argc, char **argv, 
	if (r)

		goto bad;



	r = type->ctr(tmp_store, 0, NULL);

	r = type->ctr(tmp_store, (strlen(argv[0]) > 1 ? &argv[0][1] : NULL));

	if (r) {

		ti->error = "Exception store type constructor failed";

		goto bad;

drivers/md/dm-exception-store.h

+3 −2
Original line number Diff line number Diff line
@@ -42,8 +42,7 @@ struct dm_exception_store_type { 
	const char *name;

	struct module *module;



	int (*ctr) (struct dm_exception_store *store,

		    unsigned argc, char **argv);

	int (*ctr) (struct dm_exception_store *store, char *options);



	/*

	 * Destroys this object when you've finished with it.
@@ -123,6 +122,8 @@ struct dm_exception_store { 
	unsigned chunk_shift;



	void *context;



	bool userspace_supports_overflow;

};



/*

drivers/md/dm-raid.c

+1 −2
Original line number Diff line number Diff line
@@ -329,8 +329,7 @@ static int validate_region_size(struct raid_set *rs, unsigned long region_size) 
		 */

		if (min_region_size > (1 << 13)) {

			/* If not a power of 2, make it the next power of 2 */

			if (min_region_size & (min_region_size - 1))

				region_size = 1 << fls(region_size);

			region_size = roundup_pow_of_two(min_region_size);

			DMINFO("Choosing default region size of %lu sectors",

			       region_size);

		} else {

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