Merge tag 'for-6.5/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

- Update DM crypt to allocate compound pages if possible

- Fix DM crypt target's crypt_ctr_cipher_new return value on invalid
AEAD cipher

- Fix DM flakey testing target's write bio corruption feature to
corrupt the data of a cloned bio instead of the original

- Add random_read_corrupt and random_write_corrupt features to DM
flakey target

- Fix ABBA deadlock in DM thin metadata by resetting associated bufio
client rather than destroying and recreating it

- A couple other small DM thinp cleanups

- Update DM core to support disabling block core IO stats accounting
and optimize away code that isn't needed if stats are disabled

- Other small DM core cleanups

- Improve DM integrity target to not require so much memory on 32 bit
systems. Also only allocate the recalculate buffer as needed (and
increasingly reduce its size on allocation failure)

- Update DM integrity to use %*ph for printing hexdump of a small
buffer. Also update DM integrity documentation

- Various DM core ioctl interface hardening. Now more careful about
alignment of structures and processing of input passed to the kernel
from userspace.

Also disallow the creation of DM devices named "control", "." or ".."

- Eliminate GFP_NOIO workarounds for __vmalloc and kvmalloc in DM
core's ioctl and bufio code

* tag 'for-6.5/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (28 commits)
dm: get rid of GFP_NOIO workarounds for __vmalloc and kvmalloc
dm integrity: scale down the recalculate buffer if memory allocation fails
dm integrity: only allocate recalculate buffer when needed
dm integrity: reduce vmalloc space footprint on 32-bit architectures
dm ioctl: Refuse to create device named "." or ".."
dm ioctl: Refuse to create device named "control"
dm ioctl: Avoid double-fetch of version
dm ioctl: structs and parameter strings must not overlap
dm ioctl: Avoid pointer arithmetic overflow
dm ioctl: Check dm_target_spec is sufficiently aligned
Documentation: dm-integrity: Document an example of how the tunables relate.
Documentation: dm-integrity: Document default values.
Documentation: dm-integrity: Document the meaning of "buffer".
Documentation: dm-integrity: Fix minor grammatical error.
dm integrity: Use %*ph for printing hexdump of a small buffer
dm thin: disable discards for thin-pool if no_discard_passdown
dm: remove stale/redundant dm_internal_{suspend,resume} prototypes in dm.h
dm: skip dm-stats work in alloc_io() unless needed
dm: avoid needless dm_io access if all IO accounting is disabled
dm: support turning off block-core's io stats accounting
...

Documentation/admin-guide/device-mapper/dm-flakey.rst

···
 	Perform the replacement only if bio->bi_opf has all the
 	selected flags set.
 
+  random_read_corrupt <probability>
+	During <down interval>, replace random byte in a read bio
+	with a random value. probability is an integer between
+	0 and 1000000000 meaning 0% to 100% probability of corruption.
+
+  random_write_corrupt <probability>
+	During <down interval>, replace random byte in a write bio
+	with a random value. probability is an integer between
+	0 and 1000000000 meaning 0% to 100% probability of corruption.
+
 Examples:
 
 Replaces the 32nd byte of READ bios with the value 1::

Documentation/admin-guide/device-mapper/dm-integrity.rst

···
 mode, the dm-integrity target can be used to detect silent data
 corruption on the disk or in the I/O path.
 
-There's an alternate mode of operation where dm-integrity uses bitmap
+There's an alternate mode of operation where dm-integrity uses a bitmap
 instead of a journal. If a bit in the bitmap is 1, the corresponding
 region's data and integrity tags are not synchronized - if the machine
 crashes, the unsynchronized regions will be recalculated. The bitmap mode
···
 the device. But it will only format the device if the superblock contains
 zeroes. If the superblock is neither valid nor zeroed, the dm-integrity
 target can't be loaded.
+
+Accesses to the on-disk metadata area containing checksums (aka tags) are
+buffered using dm-bufio. When an access to any given metadata area
+occurs, each unique metadata area gets its own buffer(s). The buffer size
+is capped at the size of the metadata area, but may be smaller, thereby
+requiring multiple buffers to represent the full metadata area. A smaller
+buffer size will produce a smaller resulting read/write operation to the
+metadata area for small reads/writes. The metadata is still read even in
+a full write to the data covered by a single buffer.
 
 To use the target for the first time:
 
···
 	device. If the device is already formatted, the value from the
 	superblock is used.
 
-interleave_sectors:number
+interleave_sectors:number (default 32768)
 	The number of interleaved sectors. This values is rounded down to
 	a power of two. If the device is already formatted, the value from
 	the superblock is used.
···
 	Don't interleave the data and metadata on the device. Use a
 	separate device for metadata.
 
-buffer_sectors:number
-	The number of sectors in one buffer. The value is rounded down to
-	a power of two.
+buffer_sectors:number (default 128)
+	The number of sectors in one metadata buffer. The value is rounded
+	down to a power of two.
 
-	The tag area is accessed using buffers, the buffer size is
-	configurable. The large buffer size means that the I/O size will
-	be larger, but there could be less I/Os issued.
-
-journal_watermark:number
+journal_watermark:number (default 50)
 	The journal watermark in percents. When the size of the journal
 	exceeds this watermark, the thread that flushes the journal will
 	be started.
 
-commit_time:number
+commit_time:number (default 10000)
 	Commit time in milliseconds. When this time passes, the journal is
 	written. The journal is also written immediately if the FLUSH
 	request is received.
···
 	the journal. Thus, modified sector number would be detected at
 	this stage.
 
-block_size:number
-	The size of a data block in bytes.  The larger the block size the
+block_size:number (default 512)
+	The size of a data block in bytes. The larger the block size the
 	less overhead there is for per-block integrity metadata.
-	Supported values are 512, 1024, 2048 and 4096 bytes.  If not
-	specified the default block size is 512 bytes.
+	Supported values are 512, 1024, 2048 and 4096 bytes.
 
 sectors_per_bit:number
 	In the bitmap mode, this parameter specifies the number of
···
 should not be changed when reloading the target because the layout of disk
 data depend on them and the reloaded target would be non-functional.
 
+For example, on a device using the default interleave_sectors of 32768, a
+block_size of 512, and an internal_hash of crc32c with a tag size of 4
+bytes, it will take 128 KiB of tags to track a full data area, requiring
+256 sectors of metadata per data area. With the default buffer_sectors of
+128, that means there will be 2 buffers per metadata area, or 2 buffers
+per 16 MiB of data.
 
 Status line:
 
···
     Each run contains:
 
 	* tag area - it contains integrity tags. There is one tag for each
-	  sector in the data area
+	  sector in the data area. The size of this area is always 4KiB or
+	  greater.
 	* data area - it contains data sectors. The number of data sectors
 	  in one run must be a power of two. log2 of this value is stored
 	  in the superblock.

drivers/md/dm-bufio.c

···
 
 	*data_mode = DATA_MODE_VMALLOC;
 
-	/*
-	 * __vmalloc allocates the data pages and auxiliary structures with
-	 * gfp_flags that were specified, but pagetables are always allocated
-	 * with GFP_KERNEL, no matter what was specified as gfp_mask.
-	 *
-	 * Consequently, we must set per-process flag PF_MEMALLOC_NOIO so that
-	 * all allocations done by this process (including pagetables) are done
-	 * as if GFP_NOIO was specified.
-	 */
-	if (gfp_mask & __GFP_NORETRY) {
-		unsigned int noio_flag = memalloc_noio_save();
-		void *ptr = __vmalloc(c->block_size, gfp_mask);
-
-		memalloc_noio_restore(noio_flag);
-		return ptr;
-	}
-
 	return __vmalloc(c->block_size, gfp_mask);
 }
 
···
 	kfree(c);
 }
 EXPORT_SYMBOL_GPL(dm_bufio_client_destroy);
+
+void dm_bufio_client_reset(struct dm_bufio_client *c)
+{
+	drop_buffers(c);
+	flush_work(&c->shrink_work);
+}
+EXPORT_SYMBOL_GPL(dm_bufio_client_reset);
 
 void dm_bufio_set_sector_offset(struct dm_bufio_client *c, sector_t start)
 {

drivers/md/dm-core.h

···
  */
 enum {
 	DM_IO_ACCOUNTED,
-	DM_IO_WAS_SPLIT
+	DM_IO_WAS_SPLIT,
+	DM_IO_BLK_STAT
 };
 
 static inline bool dm_io_flagged(struct dm_io *io, unsigned int bit)

drivers/md/dm-crypt.c

···
  * In order to not degrade performance with excessive locking, we try
  * non-blocking allocations without a mutex first but on failure we fallback
  * to blocking allocations with a mutex.
+ *
+ * In order to reduce allocation overhead, we try to allocate compound pages in
+ * the first pass. If they are not available, we fall back to the mempool.
  */
 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned int size)
 {
···
 	struct bio *clone;
 	unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
-	unsigned int i, len, remaining_size;
-	struct page *page;
+	unsigned int remaining_size;
+	unsigned int order = MAX_ORDER - 1;
 
 retry:
 	if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
···
 
 	remaining_size = size;
 
-	for (i = 0; i < nr_iovecs; i++) {
-		page = mempool_alloc(&cc->page_pool, gfp_mask);
-		if (!page) {
+	while (remaining_size) {
+		struct page *pages;
+		unsigned size_to_add;
+		unsigned remaining_order = __fls((remaining_size + PAGE_SIZE - 1) >> PAGE_SHIFT);
+		order = min(order, remaining_order);
+
+		while (order > 0) {
+			pages = alloc_pages(gfp_mask
+				| __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN | __GFP_COMP,
+				order);
+			if (likely(pages != NULL))
+				goto have_pages;
+			order--;
+		}
+
+		pages = mempool_alloc(&cc->page_pool, gfp_mask);
+		if (!pages) {
 			crypt_free_buffer_pages(cc, clone);
 			bio_put(clone);
 			gfp_mask |= __GFP_DIRECT_RECLAIM;
+			order = 0;
 			goto retry;
 		}
 
-		len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
-
-		__bio_add_page(clone, page, len, 0);
-		remaining_size -= len;
+have_pages:
+		size_to_add = min((unsigned)PAGE_SIZE << order, remaining_size);
+		__bio_add_page(clone, pages, size_to_add, 0);
+		remaining_size -= size_to_add;
 	}
 
 	/* Allocate space for integrity tags */
···
 
 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
 {
-	struct bio_vec *bv;
-	struct bvec_iter_all iter_all;
+	struct folio_iter fi;
 
-	bio_for_each_segment_all(bv, clone, iter_all) {
-		BUG_ON(!bv->bv_page);
-		mempool_free(bv->bv_page, &cc->page_pool);
+	if (clone->bi_vcnt > 0) { /* bio_for_each_folio_all crashes with an empty bio */
+		bio_for_each_folio_all(fi, clone) {
+			if (folio_test_large(fi.folio))
+				folio_put(fi.folio);
+			else
+				mempool_free(&fi.folio->page, &cc->page_pool);
+		}
 	}
 }
 
···
 		ret = crypt_ctr_auth_cipher(cc, cipher_api);
 		if (ret < 0) {
 			ti->error = "Invalid AEAD cipher spec";
-			return -ENOMEM;
+			return ret;
 		}
 	}
 

drivers/md/dm-flakey.c

···
 
 #define DM_MSG_PREFIX "flakey"
 
+#define PROBABILITY_BASE	1000000000
+
 #define all_corrupt_bio_flags_match(bio, fc)	\
 	(((bio)->bi_opf & (fc)->corrupt_bio_flags) == (fc)->corrupt_bio_flags)
 
···
 	unsigned int corrupt_bio_rw;
 	unsigned int corrupt_bio_value;
 	blk_opf_t corrupt_bio_flags;
+	unsigned int random_read_corrupt;
+	unsigned int random_write_corrupt;
 };
 
 enum feature_flag_bits {
···
 	const char *arg_name;
 
 	static const struct dm_arg _args[] = {
-		{0, 7, "Invalid number of feature args"},
+		{0, 11, "Invalid number of feature args"},
 		{1, UINT_MAX, "Invalid corrupt bio byte"},
 		{0, 255, "Invalid corrupt value to write into bio byte (0-255)"},
 		{0, UINT_MAX, "Invalid corrupt bio flags mask"},
+		{0, PROBABILITY_BASE, "Invalid random corrupt argument"},
 	};
 
 	/* No feature arguments supplied. */
···
 			continue;
 		}
 
+		if (!strcasecmp(arg_name, "random_read_corrupt")) {
+			if (!argc) {
+				ti->error = "Feature random_read_corrupt requires a parameter";
+				return -EINVAL;
+			}
+			r = dm_read_arg(_args + 4, as, &fc->random_read_corrupt, &ti->error);
+			if (r)
+				return r;
+			argc--;
+
+			continue;
+		}
+
+		if (!strcasecmp(arg_name, "random_write_corrupt")) {
+			if (!argc) {
+				ti->error = "Feature random_write_corrupt requires a parameter";
+				return -EINVAL;
+			}
+			r = dm_read_arg(_args + 4, as, &fc->random_write_corrupt, &ti->error);
+			if (r)
+				return r;
+			argc--;
+
+			continue;
+		}
+
 		ti->error = "Unrecognised flakey feature requested";
 		return -EINVAL;
 	}
···
 	}
 
 	if (!fc->corrupt_bio_byte && !test_bit(ERROR_READS, &fc->flags) &&
-	    !test_bit(DROP_WRITES, &fc->flags) && !test_bit(ERROR_WRITES, &fc->flags)) {
+	    !test_bit(DROP_WRITES, &fc->flags) && !test_bit(ERROR_WRITES, &fc->flags) &&
+	    !fc->random_read_corrupt && !fc->random_write_corrupt) {
 		set_bit(ERROR_WRITES, &fc->flags);
 		set_bit(ERROR_READS, &fc->flags);
 	}
···
 	bio->bi_iter.bi_sector = flakey_map_sector(ti, bio->bi_iter.bi_sector);
 }
 
-static void corrupt_bio_data(struct bio *bio, struct flakey_c *fc)
+static void corrupt_bio_common(struct bio *bio, unsigned int corrupt_bio_byte,
+			       unsigned char corrupt_bio_value)
 {
-	unsigned int corrupt_bio_byte = fc->corrupt_bio_byte - 1;
-
 	struct bvec_iter iter;
 	struct bio_vec bvec;
-
-	if (!bio_has_data(bio))
-		return;
 
 	/*
 	 * Overwrite the Nth byte of the bio's data, on whichever page
···
 	 */
 	bio_for_each_segment(bvec, bio, iter) {
 		if (bio_iter_len(bio, iter) > corrupt_bio_byte) {
-			char *segment;
-			struct page *page = bio_iter_page(bio, iter);
-			if (unlikely(page == ZERO_PAGE(0)))
-				break;
-			segment = bvec_kmap_local(&bvec);
-			segment[corrupt_bio_byte] = fc->corrupt_bio_value;
+			unsigned char *segment = bvec_kmap_local(&bvec);
+			segment[corrupt_bio_byte] = corrupt_bio_value;
 			kunmap_local(segment);
 			DMDEBUG("Corrupting data bio=%p by writing %u to byte %u "
 				"(rw=%c bi_opf=%u bi_sector=%llu size=%u)\n",
-				bio, fc->corrupt_bio_value, fc->corrupt_bio_byte,
+				bio, corrupt_bio_value, corrupt_bio_byte,
 				(bio_data_dir(bio) == WRITE) ? 'w' : 'r', bio->bi_opf,
-				(unsigned long long)bio->bi_iter.bi_sector, bio->bi_iter.bi_size);
+				(unsigned long long)bio->bi_iter.bi_sector,
+				bio->bi_iter.bi_size);
 			break;
 		}
 		corrupt_bio_byte -= bio_iter_len(bio, iter);
 	}
+}
+
+static void corrupt_bio_data(struct bio *bio, struct flakey_c *fc)
+{
+	unsigned int corrupt_bio_byte = fc->corrupt_bio_byte - 1;
+
+	if (!bio_has_data(bio))
+		return;
+
+	corrupt_bio_common(bio, corrupt_bio_byte, fc->corrupt_bio_value);
+}
+
+static void corrupt_bio_random(struct bio *bio)
+{
+	unsigned int corrupt_byte;
+	unsigned char corrupt_value;
+
+	if (!bio_has_data(bio))
+		return;
+
+	corrupt_byte = get_random_u32() % bio->bi_iter.bi_size;
+	corrupt_value = get_random_u8();
+
+	corrupt_bio_common(bio, corrupt_byte, corrupt_value);
+}
+
+static void clone_free(struct bio *clone)
+{
+	struct folio_iter fi;
+
+	if (clone->bi_vcnt > 0) { /* bio_for_each_folio_all crashes with an empty bio */
+		bio_for_each_folio_all(fi, clone)
+			folio_put(fi.folio);
+	}
+
+	bio_uninit(clone);
+	kfree(clone);
+}
+
+static void clone_endio(struct bio *clone)
+{
+	struct bio *bio = clone->bi_private;
+	bio->bi_status = clone->bi_status;
+	clone_free(clone);
+	bio_endio(bio);
+}
+
+static struct bio *clone_bio(struct dm_target *ti, struct flakey_c *fc, struct bio *bio)
+{
+	struct bio *clone;
+	unsigned size, remaining_size, nr_iovecs, order;
+	struct bvec_iter iter = bio->bi_iter;
+
+	if (unlikely(bio->bi_iter.bi_size > UIO_MAXIOV << PAGE_SHIFT))
+		dm_accept_partial_bio(bio, UIO_MAXIOV << PAGE_SHIFT >> SECTOR_SHIFT);
+
+	size = bio->bi_iter.bi_size;
+	nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+	clone = bio_kmalloc(nr_iovecs, GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN);
+	if (!clone)
+		return NULL;
+
+	bio_init(clone, fc->dev->bdev, bio->bi_inline_vecs, nr_iovecs, bio->bi_opf);
+
+	clone->bi_iter.bi_sector = flakey_map_sector(ti, bio->bi_iter.bi_sector);
+	clone->bi_private = bio;
+	clone->bi_end_io = clone_endio;
+
+	remaining_size = size;
+
+	order = MAX_ORDER - 1;
+	while (remaining_size) {
+		struct page *pages;
+		unsigned size_to_add, to_copy;
+		unsigned char *virt;
+		unsigned remaining_order = __fls((remaining_size + PAGE_SIZE - 1) >> PAGE_SHIFT);
+		order = min(order, remaining_order);
+
+retry_alloc_pages:
+		pages = alloc_pages(GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN | __GFP_COMP, order);
+		if (unlikely(!pages)) {
+			if (order) {
+				order--;
+				goto retry_alloc_pages;
+			}
+			clone_free(clone);
+			return NULL;
+		}
+		size_to_add = min((unsigned)PAGE_SIZE << order, remaining_size);
+
+		virt = page_to_virt(pages);
+		to_copy = size_to_add;
+		do {
+			struct bio_vec bvec = bvec_iter_bvec(bio->bi_io_vec, iter);
+			unsigned this_step = min(bvec.bv_len, to_copy);
+			void *map = bvec_kmap_local(&bvec);
+			memcpy(virt, map, this_step);
+			kunmap_local(map);
+
+			bvec_iter_advance(bio->bi_io_vec, &iter, this_step);
+			to_copy -= this_step;
+			virt += this_step;
+		} while (to_copy);
+
+		__bio_add_page(clone, pages, size_to_add, 0);
+		remaining_size -= size_to_add;
+	}
+
+	return clone;
 }
 
 static int flakey_map(struct dm_target *ti, struct bio *bio)
···
 	/* Are we alive ? */
 	elapsed = (jiffies - fc->start_time) / HZ;
 	if (elapsed % (fc->up_interval + fc->down_interval) >= fc->up_interval) {
+		bool corrupt_fixed, corrupt_random;
 		/*
 		 * Flag this bio as submitted while down.
 		 */
···
 		/*
 		 * Corrupt matching writes.
 		 */
-		if (fc->corrupt_bio_byte) {
-			if (fc->corrupt_bio_rw == WRITE) {
-				if (all_corrupt_bio_flags_match(bio, fc))
-					corrupt_bio_data(bio, fc);
+		corrupt_fixed = false;
+		corrupt_random = false;
+		if (fc->corrupt_bio_byte && fc->corrupt_bio_rw == WRITE) {
+			if (all_corrupt_bio_flags_match(bio, fc))
+				corrupt_fixed = true;
+		}
+		if (fc->random_write_corrupt) {
+			u64 rnd = get_random_u64();
+			u32 rem = do_div(rnd, PROBABILITY_BASE);
+			if (rem < fc->random_write_corrupt)
+				corrupt_random = true;
+		}
+		if (corrupt_fixed || corrupt_random) {
+			struct bio *clone = clone_bio(ti, fc, bio);
+			if (clone) {
+				if (corrupt_fixed)
+					corrupt_bio_data(clone, fc);
+				if (corrupt_random)
+					corrupt_bio_random(clone);
+				submit_bio(clone);
+				return DM_MAPIO_SUBMITTED;
 			}
-			goto map_bio;
 		}
 	}
 
···
 				 */
 				corrupt_bio_data(bio, fc);
 			}
+		}
+		if (fc->random_read_corrupt) {
+			u64 rnd = get_random_u64();
+			u32 rem = do_div(rnd, PROBABILITY_BASE);
+			if (rem < fc->random_read_corrupt)
+				corrupt_bio_random(bio);
 		}
 		if (test_bit(ERROR_READS, &fc->flags)) {
 			/*
···
 		error_reads = test_bit(ERROR_READS, &fc->flags);
 		drop_writes = test_bit(DROP_WRITES, &fc->flags);
 		error_writes = test_bit(ERROR_WRITES, &fc->flags);
-		DMEMIT(" %u", error_reads + drop_writes + error_writes + (fc->corrupt_bio_byte > 0) * 5);
+		DMEMIT(" %u", error_reads + drop_writes + error_writes +
+			(fc->corrupt_bio_byte > 0) * 5 +
+			(fc->random_read_corrupt > 0) * 2 +
+			(fc->random_write_corrupt > 0) * 2);
 
 		if (error_reads)
 			DMEMIT(" error_reads");
···
 			       fc->corrupt_bio_byte,
 			       (fc->corrupt_bio_rw == WRITE) ? 'w' : 'r',
 			       fc->corrupt_bio_value, fc->corrupt_bio_flags);
+
+		if (fc->random_read_corrupt > 0)
+			DMEMIT(" random_read_corrupt %u", fc->random_read_corrupt);
+		if (fc->random_write_corrupt > 0)
+			DMEMIT(" random_write_corrupt %u", fc->random_write_corrupt);
 
 		break;
 

drivers/md/dm-integrity.c

···
 #define DEFAULT_BUFFER_SECTORS		128
 #define DEFAULT_JOURNAL_WATERMARK	50
 #define DEFAULT_SYNC_MSEC		10000
-#define DEFAULT_MAX_JOURNAL_SECTORS	131072
+#define DEFAULT_MAX_JOURNAL_SECTORS	(IS_ENABLED(CONFIG_64BIT) ? 131072 : 8192)
 #define MIN_LOG2_INTERLEAVE_SECTORS	3
 #define MAX_LOG2_INTERLEAVE_SECTORS	31
 #define METADATA_WORKQUEUE_MAX_ACTIVE	16
-#define RECALC_SECTORS			32768
+#define RECALC_SECTORS			(IS_ENABLED(CONFIG_64BIT) ? 32768 : 2048)
 #define RECALC_WRITE_SUPER		16
 #define BITMAP_BLOCK_SIZE		4096	/* don't change it */
 #define BITMAP_FLUSH_INTERVAL		(10 * HZ)
···
 
 	struct workqueue_struct *recalc_wq;
 	struct work_struct recalc_work;
-	u8 *recalc_buffer;
-	u8 *recalc_tags;
 
 	struct bio_list flush_bio_list;
 
···
 #define JOURNAL_IO_MEMPOOL	32
 
 #ifdef DEBUG_PRINT
-#define DEBUG_print(x, ...)	printk(KERN_DEBUG x, ##__VA_ARGS__)
-static void __DEBUG_bytes(__u8 *bytes, size_t len, const char *msg, ...)
-{
-	va_list args;
-
-	va_start(args, msg);
-	vprintk(msg, args);
-	va_end(args);
-	if (len)
-		pr_cont(":");
-	while (len) {
-		pr_cont(" %02x", *bytes);
-		bytes++;
-		len--;
-	}
-	pr_cont("\n");
-}
-#define DEBUG_bytes(bytes, len, msg, ...)	__DEBUG_bytes(bytes, len, KERN_DEBUG msg, ##__VA_ARGS__)
+#define DEBUG_print(x, ...)			printk(KERN_DEBUG x, ##__VA_ARGS__)
+#define DEBUG_bytes(bytes, len, msg, ...)	printk(KERN_DEBUG msg "%s%*ph\n", ##__VA_ARGS__, \
+						       len ? ": " : "", len, bytes)
 #else
 #define DEBUG_print(x, ...)			do { } while (0)
 #define DEBUG_bytes(bytes, len, msg, ...)	do { } while (0)
···
 static void integrity_recalc(struct work_struct *w)
 {
 	struct dm_integrity_c *ic = container_of(w, struct dm_integrity_c, recalc_work);
+	size_t recalc_tags_size;
+	u8 *recalc_buffer = NULL;
+	u8 *recalc_tags = NULL;
 	struct dm_integrity_range range;
 	struct dm_io_request io_req;
 	struct dm_io_region io_loc;
···
 	unsigned int i;
 	int r;
 	unsigned int super_counter = 0;
+	unsigned recalc_sectors = RECALC_SECTORS;
+
+retry:
+	recalc_buffer = __vmalloc(recalc_sectors << SECTOR_SHIFT, GFP_NOIO);
+	if (!recalc_buffer) {
+oom:
+		recalc_sectors >>= 1;
+		if (recalc_sectors >= 1U << ic->sb->log2_sectors_per_block)
+			goto retry;
+		DMCRIT("out of memory for recalculate buffer - recalculation disabled");
+		goto free_ret;
+	}
+	recalc_tags_size = (recalc_sectors >> ic->sb->log2_sectors_per_block) * ic->tag_size;
+	if (crypto_shash_digestsize(ic->internal_hash) > ic->tag_size)
+		recalc_tags_size += crypto_shash_digestsize(ic->internal_hash) - ic->tag_size;
+	recalc_tags = kvmalloc(recalc_tags_size, GFP_NOIO);
+	if (!recalc_tags) {
+		vfree(recalc_buffer);
+		goto oom;
+	}
 
 	DEBUG_print("start recalculation... (position %llx)\n", le64_to_cpu(ic->sb->recalc_sector));
 
···
 	}
 
 	get_area_and_offset(ic, range.logical_sector, &area, &offset);
-	range.n_sectors = min((sector_t)RECALC_SECTORS, ic->provided_data_sectors - range.logical_sector);
+	range.n_sectors = min((sector_t)recalc_sectors, ic->provided_data_sectors - range.logical_sector);
 	if (!ic->meta_dev)
 		range.n_sectors = min(range.n_sectors, ((sector_t)1U << ic->sb->log2_interleave_sectors) - (unsigned int)offset);
 
···
 
 	io_req.bi_opf = REQ_OP_READ;
 	io_req.mem.type = DM_IO_VMA;
-	io_req.mem.ptr.addr = ic->recalc_buffer;
+	io_req.mem.ptr.addr = recalc_buffer;
 	io_req.notify.fn = NULL;
 	io_req.client = ic->io;
 	io_loc.bdev = ic->dev->bdev;
···
 		goto err;
 	}
 
-	t = ic->recalc_tags;
+	t = recalc_tags;
 	for (i = 0; i < n_sectors; i += ic->sectors_per_block) {
-		integrity_sector_checksum(ic, logical_sector + i, ic->recalc_buffer + (i << SECTOR_SHIFT), t);
+		integrity_sector_checksum(ic, logical_sector + i, recalc_buffer + (i << SECTOR_SHIFT), t);
 		t += ic->tag_size;
 	}
 
 	metadata_block = get_metadata_sector_and_offset(ic, area, offset, &metadata_offset);
 
-	r = dm_integrity_rw_tag(ic, ic->recalc_tags, &metadata_block, &metadata_offset, t - ic->recalc_tags, TAG_WRITE);
+	r = dm_integrity_rw_tag(ic, recalc_tags, &metadata_block, &metadata_offset, t - recalc_tags, TAG_WRITE);
 	if (unlikely(r)) {
 		dm_integrity_io_error(ic, "writing tags", r);
 		goto err;
···
 
 err:
 	remove_range(ic, &range);
-	return;
+	goto free_ret;
 
 unlock_ret:
 	spin_unlock_irq(&ic->endio_wait.lock);
 
 	recalc_write_super(ic);
+
+free_ret:
+	vfree(recalc_buffer);
+	kvfree(recalc_tags);
 }
 
 static void bitmap_block_work(struct work_struct *w)
···
 	}
 
 	if (ic->internal_hash) {
-		size_t recalc_tags_size;
-
 		ic->recalc_wq = alloc_workqueue("dm-integrity-recalc", WQ_MEM_RECLAIM, 1);
 		if (!ic->recalc_wq) {
 			ti->error = "Cannot allocate workqueue";
···
 			goto bad;
 		}
 		INIT_WORK(&ic->recalc_work, integrity_recalc);
-		ic->recalc_buffer = vmalloc(RECALC_SECTORS << SECTOR_SHIFT);
-		if (!ic->recalc_buffer) {
-			ti->error = "Cannot allocate buffer for recalculating";
-			r = -ENOMEM;
-			goto bad;
-		}
-		recalc_tags_size = (RECALC_SECTORS >> ic->sb->log2_sectors_per_block) * ic->tag_size;
-		if (crypto_shash_digestsize(ic->internal_hash) > ic->tag_size)
-			recalc_tags_size += crypto_shash_digestsize(ic->internal_hash) - ic->tag_size;
-		ic->recalc_tags = kvmalloc(recalc_tags_size, GFP_KERNEL);
-		if (!ic->recalc_tags) {
-			ti->error = "Cannot allocate tags for recalculating";
-			r = -ENOMEM;
-			goto bad;
-		}
 	} else {
 		if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING)) {
 			ti->error = "Recalculate can only be specified with internal_hash";
···
 		destroy_workqueue(ic->writer_wq);
 	if (ic->recalc_wq)
 		destroy_workqueue(ic->recalc_wq);
-	vfree(ic->recalc_buffer);
-	kvfree(ic->recalc_tags);
 	kvfree(ic->bbs);
 	if (ic->bufio)
 		dm_bufio_client_destroy(ic->bufio);

drivers/md/dm-ioctl.c

···
 static int check_name(const char *name)
 {
 	if (strchr(name, '/')) {
-		DMERR("invalid device name");
+		DMERR("device name cannot contain '/'");
+		return -EINVAL;
+	}
+
+	if (strcmp(name, DM_CONTROL_NODE) == 0 ||
+	    strcmp(name, ".") == 0 ||
+	    strcmp(name, "..") == 0) {
+		DMERR("device name cannot be \"%s\", \".\", or \"..\"", DM_CONTROL_NODE);
 		return -EINVAL;
 	}
 
···
 	return mode;
 }
 
-static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
+static int next_target(struct dm_target_spec *last, uint32_t next, const char *end,
 		       struct dm_target_spec **spec, char **target_params)
 {
+	static_assert(__alignof__(struct dm_target_spec) <= 8,
+		"struct dm_target_spec must not require more than 8-byte alignment");
+
+	/*
+	 * Number of bytes remaining, starting with last. This is always
+	 * sizeof(struct dm_target_spec) or more, as otherwise *last was
+	 * out of bounds already.
+	 */
+	size_t remaining = end - (char *)last;
+
+	/*
+	 * There must be room for both the next target spec and the
+	 * NUL-terminator of the target itself.
+	 */
+	if (remaining - sizeof(struct dm_target_spec) <= next) {
+		DMERR("Target spec extends beyond end of parameters");
+		return -EINVAL;
+	}
+
+	if (next % __alignof__(struct dm_target_spec)) {
+		DMERR("Next dm_target_spec (offset %u) is not %zu-byte aligned",
+		      next, __alignof__(struct dm_target_spec));
+		return -EINVAL;
+	}
+
 	*spec = (struct dm_target_spec *) ((unsigned char *) last + next);
 	*target_params = (char *) (*spec + 1);
 
-	if (*spec < (last + 1))
-		return -EINVAL;
-
-	return invalid_str(*target_params, end);
+	return 0;
 }
 
 static int populate_table(struct dm_table *table,
···
 	unsigned int i = 0;
 	struct dm_target_spec *spec = (struct dm_target_spec *) param;
 	uint32_t next = param->data_start;
-	void *end = (void *) param + param_size;
+	const char *const end = (const char *) param + param_size;
 	char *target_params;
+	size_t min_size = sizeof(struct dm_ioctl);
 
 	if (!param->target_count) {
 		DMERR("%s: no targets specified", __func__);
···
 	}
 
 	for (i = 0; i < param->target_count; i++) {
+		const char *nul_terminator;
+
+		if (next < min_size) {
+			DMERR("%s: next target spec (offset %u) overlaps %s",
+			      __func__, next, i ? "previous target" : "'struct dm_ioctl'");
+			return -EINVAL;
+		}
 
 		r = next_target(spec, next, end, &spec, &target_params);
 		if (r) {
 			DMERR("unable to find target");
 			return r;
 		}
+
+		nul_terminator = memchr(target_params, 0, (size_t)(end - target_params));
+		if (nul_terminator == NULL) {
+			DMERR("%s: target parameters not NUL-terminated", __func__);
+			return -EINVAL;
+		}
+
+		/* Add 1 for NUL terminator */
+		min_size = (size_t)(nul_terminator - (const char *)spec) + 1;
 
 		r = dm_table_add_target(table, spec->target_type,
 					(sector_t) spec->sector_start,
···
  * As well as checking the version compatibility this always
  * copies the kernel interface version out.
  */
-static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
+static int check_version(unsigned int cmd, struct dm_ioctl __user *user,
+			 struct dm_ioctl *kernel_params)
 {
-	uint32_t version[3];
 	int r = 0;
 
-	if (copy_from_user(version, user->version, sizeof(version)))
+	/* Make certain version is first member of dm_ioctl struct */
+	BUILD_BUG_ON(offsetof(struct dm_ioctl, version) != 0);
+
+	if (copy_from_user(kernel_params->version, user->version, sizeof(kernel_params->version)))
 		return -EFAULT;
 
-	if ((version[0] != DM_VERSION_MAJOR) ||
-	    (version[1] > DM_VERSION_MINOR)) {
+	if ((kernel_params->version[0] != DM_VERSION_MAJOR) ||
+	    (kernel_params->version[1] > DM_VERSION_MINOR)) {
 		DMERR("ioctl interface mismatch: kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
 		      DM_VERSION_MAJOR, DM_VERSION_MINOR,
 		      DM_VERSION_PATCHLEVEL,
-		      version[0], version[1], version[2], cmd);
+		      kernel_params->version[0],
+		      kernel_params->version[1],
+		      kernel_params->version[2],
+		      cmd);
 		r = -EINVAL;
 	}
 
 	/*
 	 * Fill in the kernel version.
 	 */
-	version[0] = DM_VERSION_MAJOR;
-	version[1] = DM_VERSION_MINOR;
-	version[2] = DM_VERSION_PATCHLEVEL;
-	if (copy_to_user(user->version, version, sizeof(version)))
+	kernel_params->version[0] = DM_VERSION_MAJOR;
+	kernel_params->version[1] = DM_VERSION_MINOR;
+	kernel_params->version[2] = DM_VERSION_PATCHLEVEL;
+	if (copy_to_user(user->version, kernel_params->version, sizeof(kernel_params->version)))
 		return -EFAULT;
 
 	return r;
···
 	struct dm_ioctl *dmi;
 	int secure_data;
 	const size_t minimum_data_size = offsetof(struct dm_ioctl, data);
-	unsigned int noio_flag;
 
-	if (copy_from_user(param_kernel, user, minimum_data_size))
+	/* check_version() already copied version from userspace, avoid TOCTOU */
+	if (copy_from_user((char *)param_kernel + sizeof(param_kernel->version),
+			   (char __user *)user + sizeof(param_kernel->version),
+			   minimum_data_size - sizeof(param_kernel->version)))
 		return -EFAULT;
 
 	if (param_kernel->data_size < minimum_data_size) {
···
 	 * Use kmalloc() rather than vmalloc() when we can.
 	 */
 	dmi = NULL;
-	noio_flag = memalloc_noio_save();
-	dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL | __GFP_HIGH);
-	memalloc_noio_restore(noio_flag);
+	dmi = kvmalloc(param_kernel->data_size, GFP_NOIO | __GFP_HIGH);
 
 	if (!dmi) {
 		if (secure_data && clear_user(user, param_kernel->data_size))
···
 	 * Check the interface version passed in.  This also
 	 * writes out the kernel's interface version.
 	 */
-	r = check_version(cmd, user);
+	r = check_version(cmd, user, &param_kernel);
 	if (r)
 		return r;
 

drivers/md/dm-thin-metadata.c

···
 	r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
 				 &pmd->tm, &pmd->metadata_sm);
 	if (r < 0) {
+		pmd->tm = NULL;
+		pmd->metadata_sm = NULL;
 		DMERR("tm_create_with_sm failed");
 		return r;
 	}
···
 	if (IS_ERR(pmd->data_sm)) {
 		DMERR("sm_disk_create failed");
 		r = PTR_ERR(pmd->data_sm);
+		pmd->data_sm = NULL;
 		goto bad_cleanup_tm;
 	}
 
···
 
 bad_cleanup_nb_tm:
 	dm_tm_destroy(pmd->nb_tm);
+	pmd->nb_tm = NULL;
 bad_cleanup_data_sm:
 	dm_sm_destroy(pmd->data_sm);
+	pmd->data_sm = NULL;
 bad_cleanup_tm:
 	dm_tm_destroy(pmd->tm);
+	pmd->tm = NULL;
 	dm_sm_destroy(pmd->metadata_sm);
+	pmd->metadata_sm = NULL;
 
 	return r;
 }
···
 			       sizeof(disk_super->metadata_space_map_root),
 			       &pmd->tm, &pmd->metadata_sm);
 	if (r < 0) {
+		pmd->tm = NULL;
+		pmd->metadata_sm = NULL;
 		DMERR("tm_open_with_sm failed");
 		goto bad_unlock_sblock;
 	}
···
 	if (IS_ERR(pmd->data_sm)) {
 		DMERR("sm_disk_open failed");
 		r = PTR_ERR(pmd->data_sm);
+		pmd->data_sm = NULL;
 		goto bad_cleanup_tm;
 	}
 
···
 
 bad_cleanup_data_sm:
 	dm_sm_destroy(pmd->data_sm);
+	pmd->data_sm = NULL;
 bad_cleanup_tm:
 	dm_tm_destroy(pmd->tm);
+	pmd->tm = NULL;
 	dm_sm_destroy(pmd->metadata_sm);
+	pmd->metadata_sm = NULL;
 bad_unlock_sblock:
 	dm_bm_unlock(sblock);
 
···
 					      bool destroy_bm)
 {
 	dm_sm_destroy(pmd->data_sm);
+	pmd->data_sm = NULL;
 	dm_sm_destroy(pmd->metadata_sm);
+	pmd->metadata_sm = NULL;
 	dm_tm_destroy(pmd->nb_tm);
+	pmd->nb_tm = NULL;
 	dm_tm_destroy(pmd->tm);
+	pmd->tm = NULL;
 	if (destroy_bm)
 		dm_block_manager_destroy(pmd->bm);
 }
···
 			       __func__, r);
 	}
 	pmd_write_unlock(pmd);
-	if (!pmd->fail_io)
-		__destroy_persistent_data_objects(pmd, true);
+	__destroy_persistent_data_objects(pmd, true);
 
 	kfree(pmd);
 	return 0;
···
 int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
 {
 	int r = -EINVAL;
-	struct dm_block_manager *old_bm = NULL, *new_bm = NULL;
 
 	/* fail_io is double-checked with pmd->root_lock held below */
 	if (unlikely(pmd->fail_io))
 		return r;
 
-	/*
-	 * Replacement block manager (new_bm) is created and old_bm destroyed outside of
-	 * pmd root_lock to avoid ABBA deadlock that would result (due to life-cycle of
-	 * shrinker associated with the block manager's bufio client vs pmd root_lock).
-	 * - must take shrinker_rwsem without holding pmd->root_lock
-	 */
-	new_bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
-					 THIN_MAX_CONCURRENT_LOCKS);
-
 	pmd_write_lock(pmd);
 	if (pmd->fail_io) {
 		pmd_write_unlock(pmd);
-		goto out;
+		return r;
 	}
-
 	__set_abort_with_changes_flags(pmd);
-	__destroy_persistent_data_objects(pmd, false);
-	old_bm = pmd->bm;
-	if (IS_ERR(new_bm)) {
-		DMERR("could not create block manager during abort");
-		pmd->bm = NULL;
-		r = PTR_ERR(new_bm);
-		goto out_unlock;
-	}
 
-	pmd->bm = new_bm;
+	/* destroy data_sm/metadata_sm/nb_tm/tm */
+	__destroy_persistent_data_objects(pmd, false);
+
+	/* reset bm */
+	dm_block_manager_reset(pmd->bm);
+
+	/* rebuild data_sm/metadata_sm/nb_tm/tm */
 	r = __open_or_format_metadata(pmd, false);
-	if (r) {
-		pmd->bm = NULL;
-		goto out_unlock;
-	}
-	new_bm = NULL;
-out_unlock:
 	if (r)
 		pmd->fail_io = true;
 	pmd_write_unlock(pmd);
-	dm_block_manager_destroy(old_bm);
-out:
-	if (new_bm && !IS_ERR(new_bm))
-		dm_block_manager_destroy(new_bm);
-
 	return r;
 }
 

drivers/md/dm-thin.c

···
 
 /*----------------------------------------------------------------*/
 
-static bool passdown_enabled(struct pool_c *pt)
-{
-	return pt->adjusted_pf.discard_passdown;
-}
-
 static void set_discard_callbacks(struct pool *pool)
 {
 	struct pool_c *pt = pool->ti->private;
 
-	if (passdown_enabled(pt)) {
+	if (pt->adjusted_pf.discard_passdown) {
 		pool->process_discard_cell = process_discard_cell_passdown;
 		pool->process_prepared_discard = process_prepared_discard_passdown_pt1;
 		pool->process_prepared_discard_pt2 = process_prepared_discard_passdown_pt2;
···
  * If discard_passdown was enabled verify that the data device
  * supports discards.  Disable discard_passdown if not.
  */
-static void disable_passdown_if_not_supported(struct pool_c *pt)
+static void disable_discard_passdown_if_not_supported(struct pool_c *pt)
 {
 	struct pool *pool = pt->pool;
 	struct block_device *data_bdev = pt->data_dev->bdev;
···
 
 static int pool_map(struct dm_target *ti, struct bio *bio)
 {
-	int r;
 	struct pool_c *pt = ti->private;
 	struct pool *pool = pt->pool;
 
···
 	 */
 	spin_lock_irq(&pool->lock);
 	bio_set_dev(bio, pt->data_dev->bdev);
-	r = DM_MAPIO_REMAPPED;
 	spin_unlock_irq(&pool->lock);
 
-	return r;
+	return DM_MAPIO_REMAPPED;
 }
 
 static int maybe_resize_data_dev(struct dm_target *ti, bool *need_commit)
···
 	 * They get transferred to the live pool in bind_control_target()
 	 * called from pool_preresume().
 	 */
-	if (!pt->adjusted_pf.discard_enabled) {
+
+	if (pt->adjusted_pf.discard_enabled) {
+		disable_discard_passdown_if_not_supported(pt);
+		if (!pt->adjusted_pf.discard_passdown)
+			limits->max_discard_sectors = 0;
+		/*
+		 * The pool uses the same discard limits as the underlying data
+		 * device.  DM core has already set this up.
+		 */
+	} else {
 		/*
 		 * Must explicitly disallow stacking discard limits otherwise the
 		 * block layer will stack them if pool's data device has support.
 		 */
 		limits->discard_granularity = 0;
-		return;
 	}
-
-	disable_passdown_if_not_supported(pt);
-
-	/*
-	 * The pool uses the same discard limits as the underlying data
-	 * device.  DM core has already set this up.
-	 */
 }
 
 static struct target_type pool_target = {
···
 	struct thin_c *tc = ti->private;
 	struct pool *pool = tc->pool;
 
-	if (!pool->pf.discard_enabled)
-		return;
-
-	limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
-	limits->max_discard_sectors = pool->sectors_per_block * BIO_PRISON_MAX_RANGE;
+	if (pool->pf.discard_enabled) {
+		limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
+		limits->max_discard_sectors = pool->sectors_per_block * BIO_PRISON_MAX_RANGE;
+	}
 }
 
 static struct target_type thin_target = {

drivers/md/dm-zone.c

···
 #include <linux/mm.h>
 #include <linux/sched/mm.h>
 #include <linux/slab.h>
+#include <linux/bitmap.h>
 
 #include "dm-core.h"
 
···
 void dm_cleanup_zoned_dev(struct mapped_device *md)
 {
 	if (md->disk) {
-		kfree(md->disk->conv_zones_bitmap);
+		bitmap_free(md->disk->conv_zones_bitmap);
 		md->disk->conv_zones_bitmap = NULL;
-		kfree(md->disk->seq_zones_wlock);
+		bitmap_free(md->disk->seq_zones_wlock);
 		md->disk->seq_zones_wlock = NULL;
 	}
 
···
 	switch (zone->type) {
 	case BLK_ZONE_TYPE_CONVENTIONAL:
 		if (!disk->conv_zones_bitmap) {
-			disk->conv_zones_bitmap =
-				kcalloc(BITS_TO_LONGS(disk->nr_zones),
-					sizeof(unsigned long), GFP_NOIO);
+			disk->conv_zones_bitmap = bitmap_zalloc(disk->nr_zones,
+								GFP_NOIO);
 			if (!disk->conv_zones_bitmap)
 				return -ENOMEM;
 		}
···
 	case BLK_ZONE_TYPE_SEQWRITE_REQ:
 	case BLK_ZONE_TYPE_SEQWRITE_PREF:
 		if (!disk->seq_zones_wlock) {
-			disk->seq_zones_wlock =
-				kcalloc(BITS_TO_LONGS(disk->nr_zones),
-					sizeof(unsigned long), GFP_NOIO);
+			disk->seq_zones_wlock = bitmap_zalloc(disk->nr_zones,
+							      GFP_NOIO);
 			if (!disk->seq_zones_wlock)
 				return -ENOMEM;
 		}

drivers/md/dm.c

···
 }
 EXPORT_SYMBOL_GPL(dm_start_time_ns_from_clone);
 
-static bool bio_is_flush_with_data(struct bio *bio)
+static inline bool bio_is_flush_with_data(struct bio *bio)
 {
 	return ((bio->bi_opf & REQ_PREFLUSH) && bio->bi_iter.bi_size);
 }
 
-static void dm_io_acct(struct dm_io *io, bool end)
+static inline unsigned int dm_io_sectors(struct dm_io *io, struct bio *bio)
 {
-	struct dm_stats_aux *stats_aux = &io->stats_aux;
-	unsigned long start_time = io->start_time;
-	struct mapped_device *md = io->md;
-	struct bio *bio = io->orig_bio;
-	unsigned int sectors;
-
 	/*
 	 * If REQ_PREFLUSH set, don't account payload, it will be
 	 * submitted (and accounted) after this flush completes.
 	 */
 	if (bio_is_flush_with_data(bio))
-		sectors = 0;
-	else if (likely(!(dm_io_flagged(io, DM_IO_WAS_SPLIT))))
-		sectors = bio_sectors(bio);
-	else
-		sectors = io->sectors;
+		return 0;
+	if (unlikely(dm_io_flagged(io, DM_IO_WAS_SPLIT)))
+		return io->sectors;
+	return bio_sectors(bio);
+}
 
-	if (!end)
-		bdev_start_io_acct(bio->bi_bdev, bio_op(bio), start_time);
-	else
-		bdev_end_io_acct(bio->bi_bdev, bio_op(bio), sectors,
-				 start_time);
+static void dm_io_acct(struct dm_io *io, bool end)
+{
+	struct bio *bio = io->orig_bio;
+
+	if (dm_io_flagged(io, DM_IO_BLK_STAT)) {
+		if (!end)
+			bdev_start_io_acct(bio->bi_bdev, bio_op(bio),
+					   io->start_time);
+		else
+			bdev_end_io_acct(bio->bi_bdev, bio_op(bio),
+					 dm_io_sectors(io, bio),
+					 io->start_time);
+	}
 
 	if (static_branch_unlikely(&stats_enabled) &&
-	    unlikely(dm_stats_used(&md->stats))) {
+	    unlikely(dm_stats_used(&io->md->stats))) {
 		sector_t sector;
 
-		if (likely(!dm_io_flagged(io, DM_IO_WAS_SPLIT)))
-			sector = bio->bi_iter.bi_sector;
-		else
+		if (unlikely(dm_io_flagged(io, DM_IO_WAS_SPLIT)))
 			sector = bio_end_sector(bio) - io->sector_offset;
+		else
+			sector = bio->bi_iter.bi_sector;
 
-		dm_stats_account_io(&md->stats, bio_data_dir(bio),
-				    sector, sectors,
-				    end, start_time, stats_aux);
+		dm_stats_account_io(&io->md->stats, bio_data_dir(bio),
+				    sector, dm_io_sectors(io, bio),
+				    end, io->start_time, &io->stats_aux);
 	}
 }
 
···
 	spin_lock_init(&io->lock);
 	io->start_time = jiffies;
 	io->flags = 0;
+	if (blk_queue_io_stat(md->queue))
+		dm_io_set_flag(io, DM_IO_BLK_STAT);
 
-	if (static_branch_unlikely(&stats_enabled))
+	if (static_branch_unlikely(&stats_enabled) &&
+	    unlikely(dm_stats_used(&md->stats)))
 		dm_stats_record_start(&md->stats, &io->stats_aux);
 
 	return io;
···
 		break;
 	case DM_TYPE_BIO_BASED:
 	case DM_TYPE_DAX_BIO_BASED:
+		blk_queue_flag_set(QUEUE_FLAG_IO_STAT, md->queue);
 		break;
 	case DM_TYPE_NONE:
 		WARN_ON_ONCE(true);

drivers/md/dm.h

···
 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
 		      unsigned int cookie, bool need_resize_uevent);
 
-void dm_internal_suspend(struct mapped_device *md);
-void dm_internal_resume(struct mapped_device *md);
-
 int dm_io_init(void);
 void dm_io_exit(void);
 

drivers/md/persistent-data/dm-block-manager.c

···
 }
 EXPORT_SYMBOL_GPL(dm_block_manager_destroy);
 
+void dm_block_manager_reset(struct dm_block_manager *bm)
+{
+	dm_bufio_client_reset(bm->bufio);
+}
+EXPORT_SYMBOL_GPL(dm_block_manager_reset);
+
 unsigned int dm_bm_block_size(struct dm_block_manager *bm)
 {
 	return dm_bufio_get_block_size(bm->bufio);

drivers/md/persistent-data/dm-block-manager.h

···
 	struct block_device *bdev, unsigned int block_size,
 	unsigned int max_held_per_thread);
 void dm_block_manager_destroy(struct dm_block_manager *bm);
+void dm_block_manager_reset(struct dm_block_manager *bm);
 
 unsigned int dm_bm_block_size(struct dm_block_manager *bm);
 dm_block_t dm_bm_nr_blocks(struct dm_block_manager *bm);

drivers/md/persistent-data/dm-space-map.h

···
 
 static inline void dm_sm_destroy(struct dm_space_map *sm)
 {
-	sm->destroy(sm);
+	if (sm)
+		sm->destroy(sm);
 }
 
 static inline int dm_sm_extend(struct dm_space_map *sm, dm_block_t extra_blocks)

drivers/md/persistent-data/dm-transaction-manager.c

···
 
 void dm_tm_destroy(struct dm_transaction_manager *tm)
 {
+	if (!tm)
+		return;
+
 	if (!tm->is_clone)
 		wipe_shadow_table(tm);
 

include/linux/dm-bufio.h

···
  */
 void dm_bufio_client_destroy(struct dm_bufio_client *c);
 
+void dm_bufio_client_reset(struct dm_bufio_client *c);
+
 /*
  * Set the sector range.
  * When this function is called, there must be no I/O in progress on the bufio