Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-block

Pull core block layer changes from Jens Axboe: "This is the core block IO pull request for 3.18. Apart from the new and improved flush machinery for blk-mq, this is all mostly bug fixes and cleanups. - blk-mq timeout updates and fixes from Christoph. - Removal of REQ_END, also from Christoph. We pass it through the ->queue_rq() hook for blk-mq instead, freeing up one of the request bits. The space was overly tight on 32-bit, so Martin also killed REQ_KERNEL since it's no longer used. - blk integrity updates and fixes from Martin and Gu Zheng. - Update to the flush machinery for blk-mq from Ming Lei. Now we have a per hardware context flush request, which both cleans up the code should scale better for flush intensive workloads on blk-mq. - Improve the error printing, from Rob Elliott. - Backing device improvements and cleanups from Tejun. - Fixup of a misplaced rq_complete() tracepoint from Hannes. - Make blk_get_request() return error pointers, fixing up issues where we NULL deref when a device goes bad or missing. From Joe Lawrence. - Prep work for drastically reducing the memory consumption of dm devices from Junichi Nomura. This allows creating clone bio sets without preallocating a lot of memory. - Fix a blk-mq hang on certain combinations of queue depths and hardware queues from me. - Limit memory consumption for blk-mq devices for crash dump scenarios and drivers that use crazy high depths (certain SCSI shared tag setups). We now just use a single queue and limited depth for that" * 'for-3.18/core' of git://git.kernel.dk/linux-block: (58 commits) block: Remove REQ_KERNEL blk-mq: allocate cpumask on the home node bio-integrity: remove the needless fail handle of bip_slab creating block: include func name in __get_request prints block: make blk_update_request print prefix match ratelimited prefix blk-merge: don't compute bi_phys_segments from bi_vcnt for cloned bio block: fix alignment_offset math that assumes io_min is a power-of-2 blk-mq: Make bt_clear_tag() easier to read blk-mq: fix potential hang if rolling wakeup depth is too high block: add bioset_create_nobvec() block: use bio_clone_fast() in blk_rq_prep_clone() block: misplaced rq_complete tracepoint sd: Honor block layer integrity handling flags block: Replace strnicmp with strncasecmp block: Add T10 Protection Information functions block: Don't merge requests if integrity flags differ block: Integrity checksum flag block: Relocate bio integrity flags block: Add a disk flag to block integrity profile block: Add prefix to block integrity profile flags ...
author: Linus Torvalds <torvalds@linux-foundation.org> 2014-10-18 11:53:51 -0700
committer: Linus Torvalds <torvalds@linux-foundation.org> 2014-10-18 11:53:51 -0700
commit: d3dc366bbaf07c125561e90d6da4bb147741101a (patch)
tree: 6eb7e79a8ec9df1fa705393c6d15ccea3d104661 /block
parent: 511c41d9e6665a07aca94eb00983cf6d77dd87ff (diff)
parent: e19a8a0ad2d255316830ead05b59c5a704434cbb (diff)
24 files changed, 791 insertions, 607 deletions
diff --git a/block/Kconfig b/block/Kconfig
index 2429515c05c2..161491d0a879 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -77,6 +77,7 @@ config BLK_DEV_BSGLIB
 
 config BLK_DEV_INTEGRITY
 	bool "Block layer data integrity support"
+	select CRC_T10DIF if BLK_DEV_INTEGRITY
 	---help---
 	Some storage devices allow extra information to be
 	stored/retrieved to help protect the data.  The block layer
diff --git a/block/Makefile b/block/Makefile
index a2ce6ac935ec..00ecc97629db 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -20,6 +20,6 @@ obj-$(CONFIG_IOSCHED_DEADLINE)	+= deadline-iosched.o
 obj-$(CONFIG_IOSCHED_CFQ)	+= cfq-iosched.o
 
 obj-$(CONFIG_BLOCK_COMPAT)	+= compat_ioctl.o
-obj-$(CONFIG_BLK_DEV_INTEGRITY)	+= blk-integrity.o
 obj-$(CONFIG_BLK_CMDLINE_PARSER)	+= cmdline-parser.o
-obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o
+obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o
+
diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index f14b4abbebd8..0984232e429f 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -79,6 +79,7 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
 	bip->bip_slab = idx;
 	bip->bip_bio = bio;
 	bio->bi_integrity = bip;
+	bio->bi_rw |= REQ_INTEGRITY;
 
 	return bip;
 err:
@@ -96,11 +97,12 @@ EXPORT_SYMBOL(bio_integrity_alloc);
  */
 void bio_integrity_free(struct bio *bio)
 {
-	struct bio_integrity_payload *bip = bio->bi_integrity;
+	struct bio_integrity_payload *bip = bio_integrity(bio);
 	struct bio_set *bs = bio->bi_pool;
 
-	if (bip->bip_owns_buf)
-		kfree(bip->bip_buf);
+	if (bip->bip_flags & BIP_BLOCK_INTEGRITY)
+		kfree(page_address(bip->bip_vec->bv_page) +
+		      bip->bip_vec->bv_offset);
 
 	if (bs) {
 		if (bip->bip_slab != BIO_POOL_NONE)
@@ -128,7 +130,7 @@ EXPORT_SYMBOL(bio_integrity_free);
 int bio_integrity_add_page(struct bio *bio, struct page *page,
 			   unsigned int len, unsigned int offset)
 {
-	struct bio_integrity_payload *bip = bio->bi_integrity;
+	struct bio_integrity_payload *bip = bio_integrity(bio);
 	struct bio_vec *iv;
 
 	if (bip->bip_vcnt >= bip->bip_max_vcnt) {
@@ -147,24 +149,6 @@ int bio_integrity_add_page(struct bio *bio, struct page *page,
 }
 EXPORT_SYMBOL(bio_integrity_add_page);
 
-static int bdev_integrity_enabled(struct block_device *bdev, int rw)
-{
-	struct blk_integrity *bi = bdev_get_integrity(bdev);
-
-	if (bi == NULL)
-		return 0;
-
-	if (rw == READ && bi->verify_fn != NULL &&
-	    (bi->flags & INTEGRITY_FLAG_READ))
-		return 1;
-
-	if (rw == WRITE && bi->generate_fn != NULL &&
-	    (bi->flags & INTEGRITY_FLAG_WRITE))
-		return 1;
-
-	return 0;
-}
-
 /**
  * bio_integrity_enabled - Check whether integrity can be passed
  * @bio:	bio to check
@@ -174,171 +158,86 @@ static int bdev_integrity_enabled(struct block_device *bdev, int rw)
  * set prior to calling.  The functions honors the write_generate and
  * read_verify flags in sysfs.
  */
-int bio_integrity_enabled(struct bio *bio)
+bool bio_integrity_enabled(struct bio *bio)
 {
+	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
+
 	if (!bio_is_rw(bio))
-		return 0;
+		return false;
 
 	/* Already protected? */
 	if (bio_integrity(bio))
-		return 0;
+		return false;
+
+	if (bi == NULL)
+		return false;
+
+	if (bio_data_dir(bio) == READ && bi->verify_fn != NULL &&
+	    (bi->flags & BLK_INTEGRITY_VERIFY))
+		return true;
+
+	if (bio_data_dir(bio) == WRITE && bi->generate_fn != NULL &&
+	    (bi->flags & BLK_INTEGRITY_GENERATE))
+		return true;
 
-	return bdev_integrity_enabled(bio->bi_bdev, bio_data_dir(bio));
+	return false;
 }
 EXPORT_SYMBOL(bio_integrity_enabled);
 
 /**
- * bio_integrity_hw_sectors - Convert 512b sectors to hardware ditto
+ * bio_integrity_intervals - Return number of integrity intervals for a bio
  * @bi:		blk_integrity profile for device
- * @sectors:	Number of 512 sectors to convert
+ * @sectors:	Size of the bio in 512-byte sectors
  *
  * Description: The block layer calculates everything in 512 byte
- * sectors but integrity metadata is done in terms of the hardware
- * sector size of the storage device.  Convert the block layer sectors
- * to physical sectors.
+ * sectors but integrity metadata is done in terms of the data integrity
+ * interval size of the storage device.  Convert the block layer sectors
+ * to the appropriate number of integrity intervals.
  */
-static inline unsigned int bio_integrity_hw_sectors(struct blk_integrity *bi,
-						    unsigned int sectors)
+static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
+						   unsigned int sectors)
 {
-	/* At this point there are only 512b or 4096b DIF/EPP devices */
-	if (bi->sector_size == 4096)
-		return sectors >>= 3;
-
-	return sectors;
+	return sectors >> (ilog2(bi->interval) - 9);
 }
 
 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
 					       unsigned int sectors)
 {
-	return bio_integrity_hw_sectors(bi, sectors) * bi->tuple_size;
+	return bio_integrity_intervals(bi, sectors) * bi->tuple_size;
 }
 
 /**
- * bio_integrity_tag_size - Retrieve integrity tag space
- * @bio:	bio to inspect
- *
- * Description: Returns the maximum number of tag bytes that can be
- * attached to this bio. Filesystems can use this to determine how
- * much metadata to attach to an I/O.
- */
-unsigned int bio_integrity_tag_size(struct bio *bio)
-{
-	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
-
-	BUG_ON(bio->bi_iter.bi_size == 0);
-
-	return bi->tag_size * (bio->bi_iter.bi_size / bi->sector_size);
-}
-EXPORT_SYMBOL(bio_integrity_tag_size);
-
-static int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len,
-			     int set)
-{
-	struct bio_integrity_payload *bip = bio->bi_integrity;
-	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
-	unsigned int nr_sectors;
-
-	BUG_ON(bip->bip_buf == NULL);
-
-	if (bi->tag_size == 0)
-		return -1;
-
-	nr_sectors = bio_integrity_hw_sectors(bi,
-					DIV_ROUND_UP(len, bi->tag_size));
-
-	if (nr_sectors * bi->tuple_size > bip->bip_iter.bi_size) {
-		printk(KERN_ERR "%s: tag too big for bio: %u > %u\n", __func__,
-		       nr_sectors * bi->tuple_size, bip->bip_iter.bi_size);
-		return -1;
-	}
-
-	if (set)
-		bi->set_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
-	else
-		bi->get_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
-
-	return 0;
-}
-
-/**
- * bio_integrity_set_tag - Attach a tag buffer to a bio
- * @bio:	bio to attach buffer to
- * @tag_buf:	Pointer to a buffer containing tag data
- * @len:	Length of the included buffer
- *
- * Description: Use this function to tag a bio by leveraging the extra
- * space provided by devices formatted with integrity protection.  The
- * size of the integrity buffer must be <= to the size reported by
- * bio_integrity_tag_size().
- */
-int bio_integrity_set_tag(struct bio *bio, void *tag_buf, unsigned int len)
-{
-	BUG_ON(bio_data_dir(bio) != WRITE);
-
-	return bio_integrity_tag(bio, tag_buf, len, 1);
-}
-EXPORT_SYMBOL(bio_integrity_set_tag);
-
-/**
- * bio_integrity_get_tag - Retrieve a tag buffer from a bio
- * @bio:	bio to retrieve buffer from
- * @tag_buf:	Pointer to a buffer for the tag data
- * @len:	Length of the target buffer
- *
- * Description: Use this function to retrieve the tag buffer from a
- * completed I/O. The size of the integrity buffer must be <= to the
- * size reported by bio_integrity_tag_size().
- */
-int bio_integrity_get_tag(struct bio *bio, void *tag_buf, unsigned int len)
-{
-	BUG_ON(bio_data_dir(bio) != READ);
-
-	return bio_integrity_tag(bio, tag_buf, len, 0);
-}
-EXPORT_SYMBOL(bio_integrity_get_tag);
-
-/**
- * bio_integrity_generate_verify - Generate/verify integrity metadata for a bio
+ * bio_integrity_process - Process integrity metadata for a bio
  * @bio:	bio to generate/verify integrity metadata for
- * @operate:	operate number, 1 for generate, 0 for verify
+ * @proc_fn:	Pointer to the relevant processing function
  */
-static int bio_integrity_generate_verify(struct bio *bio, int operate)
+static int bio_integrity_process(struct bio *bio,
+				 integrity_processing_fn *proc_fn)
 {
 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
-	struct blk_integrity_exchg bix;
+	struct blk_integrity_iter iter;
 	struct bio_vec *bv;
-	sector_t sector;
-	unsigned int sectors, ret = 0, i;
-	void *prot_buf = bio->bi_integrity->bip_buf;
-
-	if (operate)
-		sector = bio->bi_iter.bi_sector;
-	else
-		sector = bio->bi_integrity->bip_iter.bi_sector;
+	struct bio_integrity_payload *bip = bio_integrity(bio);
+	unsigned int i, ret = 0;
+	void *prot_buf = page_address(bip->bip_vec->bv_page) +
+		bip->bip_vec->bv_offset;
 
-	bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
-	bix.sector_size = bi->sector_size;
+	iter.disk_name = bio->bi_bdev->bd_disk->disk_name;
+	iter.interval = bi->interval;
+	iter.seed = bip_get_seed(bip);
+	iter.prot_buf = prot_buf;
 
 	bio_for_each_segment_all(bv, bio, i) {
 		void *kaddr = kmap_atomic(bv->bv_page);
-		bix.data_buf = kaddr + bv->bv_offset;
-		bix.data_size = bv->bv_len;
-		bix.prot_buf = prot_buf;
-		bix.sector = sector;
-
-		if (operate)
-			bi->generate_fn(&bix);
-		else {
-			ret = bi->verify_fn(&bix);
-			if (ret) {
-				kunmap_atomic(kaddr);
-				return ret;
-			}
-		}
 
-		sectors = bv->bv_len / bi->sector_size;
-		sector += sectors;
-		prot_buf += sectors * bi->tuple_size;
+		iter.data_buf = kaddr + bv->bv_offset;
+		iter.data_size = bv->bv_len;
+
+		ret = proc_fn(&iter);
+		if (ret) {
+			kunmap_atomic(kaddr);
+			return ret;
+		}
 
 		kunmap_atomic(kaddr);
 	}
@@ -346,28 +245,6 @@ static int bio_integrity_generate_verify(struct bio *bio, int operate)
 }
 
 /**
- * bio_integrity_generate - Generate integrity metadata for a bio
- * @bio:	bio to generate integrity metadata for
- *
- * Description: Generates integrity metadata for a bio by calling the
- * block device's generation callback function.  The bio must have a
- * bip attached with enough room to accommodate the generated
- * integrity metadata.
- */
-static void bio_integrity_generate(struct bio *bio)
-{
-	bio_integrity_generate_verify(bio, 1);
-}
-
-static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
-{
-	if (bi)
-		return bi->tuple_size;
-
-	return 0;
-}
-
-/**
  * bio_integrity_prep - Prepare bio for integrity I/O
  * @bio:	bio to prepare
  *
@@ -387,17 +264,17 @@ int bio_integrity_prep(struct bio *bio)
 	unsigned long start, end;
 	unsigned int len, nr_pages;
 	unsigned int bytes, offset, i;
-	unsigned int sectors;
+	unsigned int intervals;
 
 	bi = bdev_get_integrity(bio->bi_bdev);
 	q = bdev_get_queue(bio->bi_bdev);
 	BUG_ON(bi == NULL);
 	BUG_ON(bio_integrity(bio));
 
-	sectors = bio_integrity_hw_sectors(bi, bio_sectors(bio));
+	intervals = bio_integrity_intervals(bi, bio_sectors(bio));
 
 	/* Allocate kernel buffer for protection data */
-	len = sectors * blk_integrity_tuple_size(bi);
+	len = intervals * bi->tuple_size;
 	buf = kmalloc(len, GFP_NOIO | q->bounce_gfp);
 	if (unlikely(buf == NULL)) {
 		printk(KERN_ERR "could not allocate integrity buffer\n");
@@ -416,10 +293,12 @@ int bio_integrity_prep(struct bio *bio)
 		return -EIO;
 	}
 
-	bip->bip_owns_buf = 1;
-	bip->bip_buf = buf;
+	bip->bip_flags |= BIP_BLOCK_INTEGRITY;
 	bip->bip_iter.bi_size = len;
-	bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
+	bip_set_seed(bip, bio->bi_iter.bi_sector);
+
+	if (bi->flags & BLK_INTEGRITY_IP_CHECKSUM)
+		bip->bip_flags |= BIP_IP_CHECKSUM;
 
 	/* Map it */
 	offset = offset_in_page(buf);
@@ -455,26 +334,13 @@ int bio_integrity_prep(struct bio *bio)
 
 	/* Auto-generate integrity metadata if this is a write */
 	if (bio_data_dir(bio) == WRITE)
-		bio_integrity_generate(bio);
+		bio_integrity_process(bio, bi->generate_fn);
 
 	return 0;
 }
 EXPORT_SYMBOL(bio_integrity_prep);
 
 /**
- * bio_integrity_verify - Verify integrity metadata for a bio
- * @bio:	bio to verify
- *
- * Description: This function is called to verify the integrity of a
- * bio.	 The data in the bio io_vec is compared to the integrity
- * metadata returned by the HBA.
- */
-static int bio_integrity_verify(struct bio *bio)
-{
-	return bio_integrity_generate_verify(bio, 0);
-}
-
-/**
  * bio_integrity_verify_fn - Integrity I/O completion worker
  * @work:	Work struct stored in bio to be verified
  *
@@ -487,9 +353,10 @@ static void bio_integrity_verify_fn(struct work_struct *work)
 	struct bio_integrity_payload *bip =
 		container_of(work, struct bio_integrity_payload, bip_work);
 	struct bio *bio = bip->bip_bio;
+	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 	int error;
 
-	error = bio_integrity_verify(bio);
+	error = bio_integrity_process(bio, bi->verify_fn);
 
 	/* Restore original bio completion handler */
 	bio->bi_end_io = bip->bip_end_io;
@@ -510,7 +377,7 @@ static void bio_integrity_verify_fn(struct work_struct *work)
  */
 void bio_integrity_endio(struct bio *bio, int error)
 {
-	struct bio_integrity_payload *bip = bio->bi_integrity;
+	struct bio_integrity_payload *bip = bio_integrity(bio);
 
 	BUG_ON(bip->bip_bio != bio);
 
@@ -541,7 +408,7 @@ EXPORT_SYMBOL(bio_integrity_endio);
  */
 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
 {
-	struct bio_integrity_payload *bip = bio->bi_integrity;
+	struct bio_integrity_payload *bip = bio_integrity(bio);
 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 	unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);
 
@@ -563,7 +430,7 @@ EXPORT_SYMBOL(bio_integrity_advance);
 void bio_integrity_trim(struct bio *bio, unsigned int offset,
 			unsigned int sectors)
 {
-	struct bio_integrity_payload *bip = bio->bi_integrity;
+	struct bio_integrity_payload *bip = bio_integrity(bio);
 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 
 	bio_integrity_advance(bio, offset << 9);
@@ -582,7 +449,7 @@ EXPORT_SYMBOL(bio_integrity_trim);
 int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
 			gfp_t gfp_mask)
 {
-	struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
+	struct bio_integrity_payload *bip_src = bio_integrity(bio_src);
 	struct bio_integrity_payload *bip;
 
 	BUG_ON(bip_src == NULL);
@@ -646,6 +513,4 @@ void __init bio_integrity_init(void)
 				     sizeof(struct bio_integrity_payload) +
 				     sizeof(struct bio_vec) * BIP_INLINE_VECS,
 				     0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
-	if (!bip_slab)
-		panic("Failed to create slab\n");
 }
diff --git a/block/bio.c b/block/bio.c
index 3e6331d25d90..3e6e1986a5b2 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -428,6 +428,9 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
 		front_pad = 0;
 		inline_vecs = nr_iovecs;
 	} else {
+		/* should not use nobvec bioset for nr_iovecs > 0 */
+		if (WARN_ON_ONCE(!bs->bvec_pool && nr_iovecs > 0))
+			return NULL;
 		/*
 		 * generic_make_request() converts recursion to iteration; this
 		 * means if we're running beneath it, any bios we allocate and
@@ -1900,20 +1903,9 @@ void bioset_free(struct bio_set *bs)
 }
 EXPORT_SYMBOL(bioset_free);
 
-/**
- * bioset_create  - Create a bio_set
- * @pool_size:	Number of bio and bio_vecs to cache in the mempool
- * @front_pad:	Number of bytes to allocate in front of the returned bio
- *
- * Description:
- *    Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller
- *    to ask for a number of bytes to be allocated in front of the bio.
- *    Front pad allocation is useful for embedding the bio inside
- *    another structure, to avoid allocating extra data to go with the bio.
- *    Note that the bio must be embedded at the END of that structure always,
- *    or things will break badly.
- */
-struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad)
+static struct bio_set *__bioset_create(unsigned int pool_size,
+				       unsigned int front_pad,
+				       bool create_bvec_pool)
 {
 	unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec);
 	struct bio_set *bs;
@@ -1938,9 +1930,11 @@ struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad)
 	if (!bs->bio_pool)
 		goto bad;
 
-	bs->bvec_pool = biovec_create_pool(pool_size);
-	if (!bs->bvec_pool)
-		goto bad;
+	if (create_bvec_pool) {
+		bs->bvec_pool = biovec_create_pool(pool_size);
+		if (!bs->bvec_pool)
+			goto bad;
+	}
 
 	bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0);
 	if (!bs->rescue_workqueue)
@@ -1951,8 +1945,41 @@ bad:
 	bioset_free(bs);
 	return NULL;
 }
+
+/**
+ * bioset_create  - Create a bio_set
+ * @pool_size:	Number of bio and bio_vecs to cache in the mempool
+ * @front_pad:	Number of bytes to allocate in front of the returned bio
+ *
+ * Description:
+ *    Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller
+ *    to ask for a number of bytes to be allocated in front of the bio.
+ *    Front pad allocation is useful for embedding the bio inside
+ *    another structure, to avoid allocating extra data to go with the bio.
+ *    Note that the bio must be embedded at the END of that structure always,
+ *    or things will break badly.
+ */
+struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad)
+{
+	return __bioset_create(pool_size, front_pad, true);
+}
 EXPORT_SYMBOL(bioset_create);
 
+/**
+ * bioset_create_nobvec  - Create a bio_set without bio_vec mempool
+ * @pool_size:	Number of bio to cache in the mempool
+ * @front_pad:	Number of bytes to allocate in front of the returned bio
+ *
+ * Description:
+ *    Same functionality as bioset_create() except that mempool is not
+ *    created for bio_vecs. Saving some memory for bio_clone_fast() users.
+ */
+struct bio_set *bioset_create_nobvec(unsigned int pool_size, unsigned int front_pad)
+{
+	return __bioset_create(pool_size, front_pad, false);
+}
+EXPORT_SYMBOL(bioset_create_nobvec);
+
 #ifdef CONFIG_BLK_CGROUP
 /**
  * bio_associate_current - associate a bio with %current
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index e17da947f6bd..0ac817b750db 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -822,7 +822,6 @@ static void blkcg_css_free(struct cgroup_subsys_state *css)
 static struct cgroup_subsys_state *
 blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
 {
-	static atomic64_t id_seq = ATOMIC64_INIT(0);
 	struct blkcg *blkcg;
 
 	if (!parent_css) {
@@ -836,7 +835,6 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
 
 	blkcg->cfq_weight = CFQ_WEIGHT_DEFAULT;
 	blkcg->cfq_leaf_weight = CFQ_WEIGHT_DEFAULT;
-	blkcg->id = atomic64_inc_return(&id_seq); /* root is 0, start from 1 */
 done:
 	spin_lock_init(&blkcg->lock);
 	INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_ATOMIC);
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index d3fd7aa3d2a3..c567865b5f1d 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -50,9 +50,6 @@ struct blkcg {
 	struct blkcg_gq			*blkg_hint;
 	struct hlist_head		blkg_list;
 
-	/* for policies to test whether associated blkcg has changed */
-	uint64_t			id;
-
 	/* TODO: per-policy storage in blkcg */
 	unsigned int			cfq_weight;	/* belongs to cfq */
 	unsigned int			cfq_leaf_weight;
diff --git a/block/blk-core.c b/block/blk-core.c
index 9c888bd22b00..0421b53e6431 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -83,18 +83,14 @@ void blk_queue_congestion_threshold(struct request_queue *q)
  * @bdev:	device
  *
  * Locates the passed device's request queue and returns the address of its
- * backing_dev_info
- *
- * Will return NULL if the request queue cannot be located.
+ * backing_dev_info.  This function can only be called if @bdev is opened
+ * and the return value is never NULL.
  */
 struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev)
 {
-	struct backing_dev_info *ret = NULL;
 	struct request_queue *q = bdev_get_queue(bdev);
 
-	if (q)
-		ret = &q->backing_dev_info;
-	return ret;
+	return &q->backing_dev_info;
 }
 EXPORT_SYMBOL(blk_get_backing_dev_info);
 
@@ -394,11 +390,13 @@ static void __blk_drain_queue(struct request_queue *q, bool drain_all)
 		 * be drained.  Check all the queues and counters.
 		 */
 		if (drain_all) {
+			struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
 			drain |= !list_empty(&q->queue_head);
 			for (i = 0; i < 2; i++) {
 				drain |= q->nr_rqs[i];
 				drain |= q->in_flight[i];
-				drain |= !list_empty(&q->flush_queue[i]);
+				if (fq)
+				    drain |= !list_empty(&fq->flush_queue[i]);
 			}
 		}
 
@@ -604,9 +602,6 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
 #ifdef CONFIG_BLK_CGROUP
 	INIT_LIST_HEAD(&q->blkg_list);
 #endif
-	INIT_LIST_HEAD(&q->flush_queue[0]);
-	INIT_LIST_HEAD(&q->flush_queue[1]);
-	INIT_LIST_HEAD(&q->flush_data_in_flight);
 	INIT_DELAYED_WORK(&q->delay_work, blk_delay_work);
 
 	kobject_init(&q->kobj, &blk_queue_ktype);
@@ -709,8 +704,8 @@ blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn,
 	if (!q)
 		return NULL;
 
-	q->flush_rq = kzalloc(sizeof(struct request), GFP_KERNEL);
-	if (!q->flush_rq)
+	q->fq = blk_alloc_flush_queue(q, NUMA_NO_NODE, 0);
+	if (!q->fq)
 		return NULL;
 
 	if (blk_init_rl(&q->root_rl, q, GFP_KERNEL))
@@ -746,7 +741,7 @@ blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn,
 	return q;
 
 fail:
-	kfree(q->flush_rq);
+	blk_free_flush_queue(q->fq);
 	return NULL;
 }
 EXPORT_SYMBOL(blk_init_allocated_queue);
@@ -934,8 +929,8 @@ static struct io_context *rq_ioc(struct bio *bio)
  * pressure or if @q is dead.
  *
  * Must be called with @q->queue_lock held and,
- * Returns %NULL on failure, with @q->queue_lock held.
- * Returns !%NULL on success, with @q->queue_lock *not held*.
+ * Returns ERR_PTR on failure, with @q->queue_lock held.
+ * Returns request pointer on success, with @q->queue_lock *not held*.
  */
 static struct request *__get_request(struct request_list *rl, int rw_flags,
 				     struct bio *bio, gfp_t gfp_mask)
@@ -949,7 +944,7 @@ static struct request *__get_request(struct request_list *rl, int rw_flags,
 	int may_queue;
 
 	if (unlikely(blk_queue_dying(q)))
-		return NULL;
+		return ERR_PTR(-ENODEV);
 
 	may_queue = elv_may_queue(q, rw_flags);
 	if (may_queue == ELV_MQUEUE_NO)
@@ -974,7 +969,7 @@ static struct request *__get_request(struct request_list *rl, int rw_flags,
 					 * process is not a "batcher", and not
 					 * exempted by the IO scheduler
 					 */
-					return NULL;
+					return ERR_PTR(-ENOMEM);
 				}
 			}
 		}
@@ -992,7 +987,7 @@ static struct request *__get_request(struct request_list *rl, int rw_flags,
 	 * allocated with any setting of ->nr_requests
 	 */
 	if (rl->count[is_sync] >= (3 * q->nr_requests / 2))
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	q->nr_rqs[is_sync]++;
 	rl->count[is_sync]++;
@@ -1065,8 +1060,8 @@ fail_elvpriv:
 	 * shouldn't stall IO.  Treat this request as !elvpriv.  This will
 	 * disturb iosched and blkcg but weird is bettern than dead.
 	 */
-	printk_ratelimited(KERN_WARNING "%s: request aux data allocation failed, iosched may be disturbed\n",
-			   dev_name(q->backing_dev_info.dev));
+	printk_ratelimited(KERN_WARNING "%s: dev %s: request aux data allocation failed, iosched may be disturbed\n",
+			   __func__, dev_name(q->backing_dev_info.dev));
 
 	rq->cmd_flags &= ~REQ_ELVPRIV;
 	rq->elv.icq = NULL;
@@ -1097,7 +1092,7 @@ fail_alloc:
 rq_starved:
 	if (unlikely(rl->count[is_sync] == 0))
 		rl->starved[is_sync] = 1;
-	return NULL;
+	return ERR_PTR(-ENOMEM);
 }
 
 /**
@@ -1111,8 +1106,8 @@ rq_starved:
  * function keeps retrying under memory pressure and fails iff @q is dead.
  *
  * Must be called with @q->queue_lock held and,
- * Returns %NULL on failure, with @q->queue_lock held.
- * Returns !%NULL on success, with @q->queue_lock *not held*.
+ * Returns ERR_PTR on failure, with @q->queue_lock held.
+ * Returns request pointer on success, with @q->queue_lock *not held*.
  */
 static struct request *get_request(struct request_queue *q, int rw_flags,
 				   struct bio *bio, gfp_t gfp_mask)
@@ -1125,12 +1120,12 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
 	rl = blk_get_rl(q, bio);	/* transferred to @rq on success */
 retry:
 	rq = __get_request(rl, rw_flags, bio, gfp_mask);
-	if (rq)
+	if (!IS_ERR(rq))
 		return rq;
 
 	if (!(gfp_mask & __GFP_WAIT) || unlikely(blk_queue_dying(q))) {
 		blk_put_rl(rl);
-		return NULL;
+		return rq;
 	}
 
 	/* wait on @rl and retry */
@@ -1167,7 +1162,7 @@ static struct request *blk_old_get_request(struct request_queue *q, int rw,
 
 	spin_lock_irq(q->queue_lock);
 	rq = get_request(q, rw, NULL, gfp_mask);
-	if (!rq)
+	if (IS_ERR(rq))
 		spin_unlock_irq(q->queue_lock);
 	/* q->queue_lock is unlocked at this point */
 
@@ -1219,8 +1214,8 @@ struct request *blk_make_request(struct request_queue *q, struct bio *bio,
 {
 	struct request *rq = blk_get_request(q, bio_data_dir(bio), gfp_mask);
 
-	if (unlikely(!rq))
-		return ERR_PTR(-ENOMEM);
+	if (IS_ERR(rq))
+		return rq;
 
 	blk_rq_set_block_pc(rq);
 
@@ -1614,8 +1609,8 @@ get_rq:
 	 * Returns with the queue unlocked.
 	 */
 	req = get_request(q, rw_flags, bio, GFP_NOIO);
-	if (unlikely(!req)) {
-		bio_endio(bio, -ENODEV);	/* @q is dead */
+	if (IS_ERR(req)) {
+		bio_endio(bio, PTR_ERR(req));	/* @q is dead */
 		goto out_unlock;
 	}
 
@@ -2405,11 +2400,11 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
 {
 	int total_bytes;
 
+	trace_block_rq_complete(req->q, req, nr_bytes);
+
 	if (!req->bio)
 		return false;
 
-	trace_block_rq_complete(req->q, req, nr_bytes);
-
 	/*
 	 * For fs requests, rq is just carrier of independent bio's
 	 * and each partial completion should be handled separately.
@@ -2449,8 +2444,8 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
 			error_type = "I/O";
 			break;
 		}
-		printk_ratelimited(KERN_ERR "end_request: %s error, dev %s, sector %llu\n",
-				   error_type, req->rq_disk ?
+		printk_ratelimited(KERN_ERR "%s: %s error, dev %s, sector %llu\n",
+				   __func__, error_type, req->rq_disk ?
 				   req->rq_disk->disk_name : "?",
 				   (unsigned long long)blk_rq_pos(req));
 
@@ -2931,7 +2926,7 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 	blk_rq_init(NULL, rq);
 
 	__rq_for_each_bio(bio_src, rq_src) {
-		bio = bio_clone_bioset(bio_src, gfp_mask, bs);
+		bio = bio_clone_fast(bio_src, gfp_mask, bs);
 		if (!bio)
 			goto free_and_out;
 
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 3cb5e9e7108a..20badd7b9d1b 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -28,7 +28,7 @@
  *
  * The actual execution of flush is double buffered.  Whenever a request
  * needs to execute PRE or POSTFLUSH, it queues at
- * q->flush_queue[q->flush_pending_idx].  Once certain criteria are met, a
+ * fq->flush_queue[fq->flush_pending_idx].  Once certain criteria are met, a
  * flush is issued and the pending_idx is toggled.  When the flush
  * completes, all the requests which were pending are proceeded to the next
  * step.  This allows arbitrary merging of different types of FLUSH/FUA
@@ -91,7 +91,8 @@ enum {
 	FLUSH_PENDING_TIMEOUT	= 5 * HZ,
 };
 
-static bool blk_kick_flush(struct request_queue *q);
+static bool blk_kick_flush(struct request_queue *q,
+			   struct blk_flush_queue *fq);
 
 static unsigned int blk_flush_policy(unsigned int fflags, struct request *rq)
 {
@@ -126,8 +127,6 @@ static void blk_flush_restore_request(struct request *rq)
 	/* make @rq a normal request */
 	rq->cmd_flags &= ~REQ_FLUSH_SEQ;
 	rq->end_io = rq->flush.saved_end_io;
-
-	blk_clear_rq_complete(rq);
 }
 
 static bool blk_flush_queue_rq(struct request *rq, bool add_front)
@@ -150,6 +149,7 @@ static bool blk_flush_queue_rq(struct request *rq, bool add_front)
 /**
  * blk_flush_complete_seq - complete flush sequence
  * @rq: FLUSH/FUA request being sequenced
+ * @fq: flush queue
  * @seq: sequences to complete (mask of %REQ_FSEQ_*, can be zero)
  * @error: whether an error occurred
  *
@@ -157,16 +157,17 @@ static bool blk_flush_queue_rq(struct request *rq, bool add_front)
  * completion and trigger the next step.
  *
  * CONTEXT:
- * spin_lock_irq(q->queue_lock or q->mq_flush_lock)
+ * spin_lock_irq(q->queue_lock or fq->mq_flush_lock)
  *
  * RETURNS:
  * %true if requests were added to the dispatch queue, %false otherwise.
  */
-static bool blk_flush_complete_seq(struct request *rq, unsigned int seq,
-				   int error)
+static bool blk_flush_complete_seq(struct request *rq,
+				   struct blk_flush_queue *fq,
+				   unsigned int seq, int error)
 {
 	struct request_queue *q = rq->q;
-	struct list_head *pending = &q->flush_queue[q->flush_pending_idx];
+	struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx];
 	bool queued = false, kicked;
 
 	BUG_ON(rq->flush.seq & seq);
@@ -182,12 +183,12 @@ static bool blk_flush_complete_seq(struct request *rq, unsigned int seq,
 	case REQ_FSEQ_POSTFLUSH:
 		/* queue for flush */
 		if (list_empty(pending))
-			q->flush_pending_since = jiffies;
+			fq->flush_pending_since = jiffies;
 		list_move_tail(&rq->flush.list, pending);
 		break;
 
 	case REQ_FSEQ_DATA:
-		list_move_tail(&rq->flush.list, &q->flush_data_in_flight);
+		list_move_tail(&rq->flush.list, &fq->flush_data_in_flight);
 		queued = blk_flush_queue_rq(rq, true);
 		break;
 
@@ -202,7 +203,7 @@ static bool blk_flush_complete_seq(struct request *rq, unsigned int seq,
 		list_del_init(&rq->flush.list);
 		blk_flush_restore_request(rq);
 		if (q->mq_ops)
-			blk_mq_end_io(rq, error);
+			blk_mq_end_request(rq, error);
 		else
 			__blk_end_request_all(rq, error);
 		break;
@@ -211,7 +212,7 @@ static bool blk_flush_complete_seq(struct request *rq, unsigned int seq,
 		BUG();
 	}
 
-	kicked = blk_kick_flush(q);
+	kicked = blk_kick_flush(q, fq);
 	return kicked | queued;
 }
 
@@ -222,17 +223,18 @@ static void flush_end_io(struct request *flush_rq, int error)
 	bool queued = false;
 	struct request *rq, *n;
 	unsigned long flags = 0;
+	struct blk_flush_queue *fq = blk_get_flush_queue(q, flush_rq->mq_ctx);
 
 	if (q->mq_ops) {
-		spin_lock_irqsave(&q->mq_flush_lock, flags);
-		q->flush_rq->tag = -1;
+		spin_lock_irqsave(&fq->mq_flush_lock, flags);
+		flush_rq->tag = -1;
 	}
 
-	running = &q->flush_queue[q->flush_running_idx];
-	BUG_ON(q->flush_pending_idx == q->flush_running_idx);
+	running = &fq->flush_queue[fq->flush_running_idx];
+	BUG_ON(fq->flush_pending_idx == fq->flush_running_idx);
 
 	/* account completion of the flush request */
-	q->flush_running_idx ^= 1;
+	fq->flush_running_idx ^= 1;
 
 	if (!q->mq_ops)
 		elv_completed_request(q, flush_rq);
@@ -242,7 +244,7 @@ static void flush_end_io(struct request *flush_rq, int error)
 		unsigned int seq = blk_flush_cur_seq(rq);
 
 		BUG_ON(seq != REQ_FSEQ_PREFLUSH && seq != REQ_FSEQ_POSTFLUSH);
-		queued |= blk_flush_complete_seq(rq, seq, error);
+		queued |= blk_flush_complete_seq(rq, fq, seq, error);
 	}
 
 	/*
@@ -256,71 +258,81 @@ static void flush_end_io(struct request *flush_rq, int error)
 	 * directly into request_fn may confuse the driver.  Always use
 	 * kblockd.
 	 */
-	if (queued || q->flush_queue_delayed) {
+	if (queued || fq->flush_queue_delayed) {
 		WARN_ON(q->mq_ops);
 		blk_run_queue_async(q);
 	}
-	q->flush_queue_delayed = 0;
+	fq->flush_queue_delayed = 0;
 	if (q->mq_ops)
-		spin_unlock_irqrestore(&q->mq_flush_lock, flags);
+		spin_unlock_irqrestore(&fq->mq_flush_lock, flags);
 }
 
 /**
  * blk_kick_flush - consider issuing flush request
  * @q: request_queue being kicked
+ * @fq: flush queue
  *
  * Flush related states of @q have changed, consider issuing flush request.
  * Please read the comment at the top of this file for more info.
  *
  * CONTEXT:
- * spin_lock_irq(q->queue_lock or q->mq_flush_lock)
+ * spin_lock_irq(q->queue_lock or fq->mq_flush_lock)
  *
  * RETURNS:
  * %true if flush was issued, %false otherwise.
  */
-static bool blk_kick_flush(struct request_queue *q)
+static bool blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq)
 {
-	struct list_head *pending = &q->flush_queue[q->flush_pending_idx];
+	struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx];
 	struct request *first_rq =
 		list_first_entry(pending, struct request, flush.list);
+	struct request *flush_rq = fq->flush_rq;
 
 	/* C1 described at the top of this file */
-	if (q->flush_pending_idx != q->flush_running_idx || list_empty(pending))
+	if (fq->flush_pending_idx != fq->flush_running_idx || list_empty(pending))
 		return false;
 
 	/* C2 and C3 */
-	if (!list_empty(&q->flush_data_in_flight) &&
+	if (!list_empty(&fq->flush_data_in_flight) &&
 	    time_before(jiffies,
-			q->flush_pending_since + FLUSH_PENDING_TIMEOUT))
+			fq->flush_pending_since + FLUSH_PENDING_TIMEOUT))
 		return false;
 
 	/*
 	 * Issue flush and toggle pending_idx.  This makes pending_idx
 	 * different from running_idx, which means flush is in flight.
 	 */
-	q->flush_pending_idx ^= 1;
+	fq->flush_pending_idx ^= 1;
 
-	blk_rq_init(q, q->flush_rq);
-	if (q->mq_ops)
-		blk_mq_clone_flush_request(q->flush_rq, first_rq);
+	blk_rq_init(q, flush_rq);
+
+	/*
+	 * Borrow tag from the first request since they can't
+	 * be in flight at the same time.
+	 */
+	if (q->mq_ops) {
+		flush_rq->mq_ctx = first_rq->mq_ctx;
+		flush_rq->tag = first_rq->tag;
+	}
 
-	q->flush_rq->cmd_type = REQ_TYPE_FS;
-	q->flush_rq->cmd_flags = WRITE_FLUSH | REQ_FLUSH_SEQ;
-	q->flush_rq->rq_disk = first_rq->rq_disk;
-	q->flush_rq->end_io = flush_end_io;
+	flush_rq->cmd_type = REQ_TYPE_FS;
+	flush_rq->cmd_flags = WRITE_FLUSH | REQ_FLUSH_SEQ;
+	flush_rq->rq_disk = first_rq->rq_disk;
+	flush_rq->end_io = flush_end_io;
 
-	return blk_flush_queue_rq(q->flush_rq, false);
+	return blk_flush_queue_rq(flush_rq, false);
 }
 
 static void flush_data_end_io(struct request *rq, int error)
 {
 	struct request_queue *q = rq->q;
+	struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
 
 	/*
 	 * After populating an empty queue, kick it to avoid stall.  Read
 	 * the comment in flush_end_io().
 	 */
-	if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error))
+	if (blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error))
 		blk_run_queue_async(q);
 }
 
@@ -328,20 +340,20 @@ static void mq_flush_data_end_io(struct request *rq, int error)
 {
 	struct request_queue *q = rq->q;
 	struct blk_mq_hw_ctx *hctx;
-	struct blk_mq_ctx *ctx;
+	struct blk_mq_ctx *ctx = rq->mq_ctx;
 	unsigned long flags;
+	struct blk_flush_queue *fq = blk_get_flush_queue(q, ctx);
 
-	ctx = rq->mq_ctx;
 	hctx = q->mq_ops->map_queue(q, ctx->cpu);
 
 	/*
 	 * After populating an empty queue, kick it to avoid stall.  Read
 	 * the comment in flush_end_io().
 	 */
-	spin_lock_irqsave(&q->mq_flush_lock, flags);
-	if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error))
+	spin_lock_irqsave(&fq->mq_flush_lock, flags);
+	if (blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error))
 		blk_mq_run_hw_queue(hctx, true);
-	spin_unlock_irqrestore(&q->mq_flush_lock, flags);
+	spin_unlock_irqrestore(&fq->mq_flush_lock, flags);
 }
 
 /**
@@ -361,6 +373,7 @@ void blk_insert_flush(struct request *rq)
 	struct request_queue *q = rq->q;
 	unsigned int fflags = q->flush_flags;	/* may change, cache */
 	unsigned int policy = blk_flush_policy(fflags, rq);
+	struct blk_flush_queue *fq = blk_get_flush_queue(q, rq->mq_ctx);
 
 	/*
 	 * @policy now records what operations need to be done.  Adjust
@@ -378,7 +391,7 @@ void blk_insert_flush(struct request *rq)
 	 */
 	if (!policy) {
 		if (q->mq_ops)
-			blk_mq_end_io(rq, 0);
+			blk_mq_end_request(rq, 0);
 		else
 			__blk_end_bidi_request(rq, 0, 0, 0);
 		return;
@@ -411,14 +424,14 @@ void blk_insert_flush(struct request *rq)
 	if (q->mq_ops) {
 		rq->end_io = mq_flush_data_end_io;
 
-		spin_lock_irq(&q->mq_flush_lock);
-		blk_flush_complete_seq(rq, REQ_FSEQ_ACTIONS & ~policy, 0);
-		spin_unlock_irq(&q->mq_flush_lock);
+		spin_lock_irq(&fq->mq_flush_lock);
+		blk_flush_complete_seq(rq, fq, REQ_FSEQ_ACTIONS & ~policy, 0);
+		spin_unlock_irq(&fq->mq_flush_lock);
 		return;
 	}
 	rq->end_io = flush_data_end_io;
 
-	blk_flush_complete_seq(rq, REQ_FSEQ_ACTIONS & ~policy, 0);
+	blk_flush_complete_seq(rq, fq, REQ_FSEQ_ACTIONS & ~policy, 0);
 }
 
 /**
@@ -474,7 +487,43 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
 }
 EXPORT_SYMBOL(blkdev_issue_flush);
 
-void blk_mq_init_flush(struct request_queue *q)
+struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
+		int node, int cmd_size)
+{
+	struct blk_flush_queue *fq;
+	int rq_sz = sizeof(struct request);
+
+	fq = kzalloc_node(sizeof(*fq), GFP_KERNEL, node);
+	if (!fq)
+		goto fail;
+
+	if (q->mq_ops) {
+		spin_lock_init(&fq->mq_flush_lock);
+		rq_sz = round_up(rq_sz + cmd_size, cache_line_size());
+	}
+
+	fq->flush_rq = kzalloc_node(rq_sz, GFP_KERNEL, node);
+	if (!fq->flush_rq)
+		goto fail_rq;
+
+	INIT_LIST_HEAD(&fq->flush_queue[0]);
+	INIT_LIST_HEAD(&fq->flush_queue[1]);
+	INIT_LIST_HEAD(&fq->flush_data_in_flight);
+
+	return fq;
+
+ fail_rq:
+	kfree(fq);
+ fail:
+	return NULL;
+}
+
+void blk_free_flush_queue(struct blk_flush_queue *fq)
 {
-	spin_lock_init(&q->mq_flush_lock);
+	/* bio based request queue hasn't flush queue */
+	if (!fq)
+		return;
+
+	kfree(fq->flush_rq);
+	kfree(fq);
 }
diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index 7fbab84399e6..79ffb4855af0 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -154,10 +154,10 @@ int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
 	if (!b1 || !b2)
 		return -1;
 
-	if (b1->sector_size != b2->sector_size) {
-		printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__,
-		       gd1->disk_name, gd2->disk_name,
-		       b1->sector_size, b2->sector_size);
+	if (b1->interval != b2->interval) {
+		pr_err("%s: %s/%s protection interval %u != %u\n",
+		       __func__, gd1->disk_name, gd2->disk_name,
+		       b1->interval, b2->interval);
 		return -1;
 	}
 
@@ -186,37 +186,53 @@ int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
 }
 EXPORT_SYMBOL(blk_integrity_compare);
 
-int blk_integrity_merge_rq(struct request_queue *q, struct request *req,
-			   struct request *next)
+bool blk_integrity_merge_rq(struct request_queue *q, struct request *req,
+			    struct request *next)
 {
-	if (blk_integrity_rq(req) != blk_integrity_rq(next))
-		return -1;
+	if (blk_integrity_rq(req) == 0 && blk_integrity_rq(next) == 0)
+		return true;
+
+	if (blk_integrity_rq(req) == 0 || blk_integrity_rq(next) == 0)
+		return false;
+
+	if (bio_integrity(req->bio)->bip_flags !=
+	    bio_integrity(next->bio)->bip_flags)
+		return false;
 
 	if (req->nr_integrity_segments + next->nr_integrity_segments >
 	    q->limits.max_integrity_segments)
-		return -1;
+		return false;
 
-	return 0;
+	return true;
 }
 EXPORT_SYMBOL(blk_integrity_merge_rq);
 
-int blk_integrity_merge_bio(struct request_queue *q, struct request *req,
-			    struct bio *bio)
+bool blk_integrity_merge_bio(struct request_queue *q, struct request *req,
+			     struct bio *bio)
 {
 	int nr_integrity_segs;
 	struct bio *next = bio->bi_next;
 
+	if (blk_integrity_rq(req) == 0 && bio_integrity(bio) == NULL)
+		return true;
+
+	if (blk_integrity_rq(req) == 0 || bio_integrity(bio) == NULL)
+		return false;
+
+	if (bio_integrity(req->bio)->bip_flags != bio_integrity(bio)->bip_flags)
+		return false;
+
 	bio->bi_next = NULL;
 	nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
 	bio->bi_next = next;
 
 	if (req->nr_integrity_segments + nr_integrity_segs >
 	    q->limits.max_integrity_segments)
-		return -1;
+		return false;
 
 	req->nr_integrity_segments += nr_integrity_segs;
 
-	return 0;
+	return true;
 }
 EXPORT_SYMBOL(blk_integrity_merge_bio);
 
@@ -269,42 +285,48 @@ static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page)
 		return sprintf(page, "0\n");
 }
 
-static ssize_t integrity_read_store(struct blk_integrity *bi,
-				    const char *page, size_t count)
+static ssize_t integrity_verify_store(struct blk_integrity *bi,
+				      const char *page, size_t count)
 {
 	char *p = (char *) page;
 	unsigned long val = simple_strtoul(p, &p, 10);
 
 	if (val)
-		bi->flags |= INTEGRITY_FLAG_READ;
+		bi->flags |= BLK_INTEGRITY_VERIFY;
 	else
-		bi->flags &= ~INTEGRITY_FLAG_READ;
+		bi->flags &= ~BLK_INTEGRITY_VERIFY;
 
 	return count;
 }
 
-static ssize_t integrity_read_show(struct blk_integrity *bi, char *page)
+static ssize_t integrity_verify_show(struct blk_integrity *bi, char *page)
 {
-	return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_READ) != 0);
+	return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_VERIFY) != 0);
 }
 
-static ssize_t integrity_write_store(struct blk_integrity *bi,
-				     const char *page, size_t count)
+static ssize_t integrity_generate_store(struct blk_integrity *bi,
+					const char *page, size_t count)
 {
 	char *p = (char *) page;
 	unsigned long val = simple_strtoul(p, &p, 10);
 
 	if (val)
-		bi->flags |= INTEGRITY_FLAG_WRITE;
+		bi->flags |= BLK_INTEGRITY_GENERATE;
 	else
-		bi->flags &= ~INTEGRITY_FLAG_WRITE;
+		bi->flags &= ~BLK_INTEGRITY_GENERATE;
 
 	return count;
 }
 
-static ssize_t integrity_write_show(struct blk_integrity *bi, char *page)
+static ssize_t integrity_generate_show(struct blk_integrity *bi, char *page)
+{
+	return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_GENERATE) != 0);
+}
+
+static ssize_t integrity_device_show(struct blk_integrity *bi, char *page)
 {
-	return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_WRITE) != 0);
+	return sprintf(page, "%u\n",
+		       (bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE) != 0);
 }
 
 static struct integrity_sysfs_entry integrity_format_entry = {
@@ -317,23 +339,29 @@ static struct integrity_sysfs_entry integrity_tag_size_entry = {
 	.show = integrity_tag_size_show,
 };
 
-static struct integrity_sysfs_entry integrity_read_entry = {
+static struct integrity_sysfs_entry integrity_verify_entry = {
 	.attr = { .name = "read_verify", .mode = S_IRUGO | S_IWUSR },
-	.show = integrity_read_show,
-	.store = integrity_read_store,
+	.show = integrity_verify_show,
+	.store = integrity_verify_store,
 };
 
-static struct integrity_sysfs_entry integrity_write_entry = {
+static struct integrity_sysfs_entry integrity_generate_entry = {
 	.attr = { .name = "write_generate", .mode = S_IRUGO | S_IWUSR },
-	.show = integrity_write_show,
-	.store = integrity_write_store,
+	.show = integrity_generate_show,
+	.store = integrity_generate_store,
+};
+
+static struct integrity_sysfs_entry integrity_device_entry = {
+	.attr = { .name = "device_is_integrity_capable", .mode = S_IRUGO },
+	.show = integrity_device_show,
 };
 
 static struct attribute *integrity_attrs[] = {
 	&integrity_format_entry.attr,
 	&integrity_tag_size_entry.attr,
-	&integrity_read_entry.attr,
-	&integrity_write_entry.attr,
+	&integrity_verify_entry.attr,
+	&integrity_generate_entry.attr,
+	&integrity_device_entry.attr,
 	NULL,
 };
 
@@ -406,8 +434,8 @@ int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
 
 		kobject_uevent(&bi->kobj, KOBJ_ADD);
 
-		bi->flags |= INTEGRITY_FLAG_READ | INTEGRITY_FLAG_WRITE;
-		bi->sector_size = queue_logical_block_size(disk->queue);
+		bi->flags |= BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE;
+		bi->interval = queue_logical_block_size(disk->queue);
 		disk->integrity = bi;
 	} else
 		bi = disk->integrity;
@@ -418,9 +446,8 @@ int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
 		bi->generate_fn = template->generate_fn;
 		bi->verify_fn = template->verify_fn;
 		bi->tuple_size = template->tuple_size;
-		bi->set_tag_fn = template->set_tag_fn;
-		bi->get_tag_fn = template->get_tag_fn;
 		bi->tag_size = template->tag_size;
+		bi->flags |= template->flags;
 	} else
 		bi->name = bi_unsupported_name;
 
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 77881798f793..ba99351c0f58 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -97,14 +97,18 @@ void blk_recalc_rq_segments(struct request *rq)
 
 void blk_recount_segments(struct request_queue *q, struct bio *bio)
 {
-	if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags) &&
+	bool no_sg_merge = !!test_bit(QUEUE_FLAG_NO_SG_MERGE,
+			&q->queue_flags);
+
+	if (no_sg_merge && !bio_flagged(bio, BIO_CLONED) &&
 			bio->bi_vcnt < queue_max_segments(q))
 		bio->bi_phys_segments = bio->bi_vcnt;
 	else {
 		struct bio *nxt = bio->bi_next;
 
 		bio->bi_next = NULL;
-		bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio, false);
+		bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio,
+				no_sg_merge);
 		bio->bi_next = nxt;
 	}
 
@@ -313,7 +317,7 @@ static inline int ll_new_hw_segment(struct request_queue *q,
 	if (req->nr_phys_segments + nr_phys_segs > queue_max_segments(q))
 		goto no_merge;
 
-	if (bio_integrity(bio) && blk_integrity_merge_bio(q, req, bio))
+	if (blk_integrity_merge_bio(q, req, bio) == false)
 		goto no_merge;
 
 	/*
@@ -410,7 +414,7 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
 	if (total_phys_segments > queue_max_segments(q))
 		return 0;
 
-	if (blk_integrity_rq(req) && blk_integrity_merge_rq(q, req, next))
+	if (blk_integrity_merge_rq(q, req, next) == false)
 		return 0;
 
 	/* Merge is OK... */
@@ -590,7 +594,7 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
 		return false;
 
 	/* only merge integrity protected bio into ditto rq */
-	if (bio_integrity(bio) != blk_integrity_rq(rq))
+	if (blk_integrity_merge_bio(rq->q, rq, bio) == false)
 		return false;
 
 	/* must be using the same buffer */
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index c1b92426c95e..8317175a3009 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -351,15 +351,12 @@ static void bt_clear_tag(struct blk_mq_bitmap_tags *bt, unsigned int tag)
 		return;
 
 	wait_cnt = atomic_dec_return(&bs->wait_cnt);
+	if (unlikely(wait_cnt < 0))
+		wait_cnt = atomic_inc_return(&bs->wait_cnt);
 	if (wait_cnt == 0) {
-wake:
 		atomic_add(bt->wake_cnt, &bs->wait_cnt);
 		bt_index_atomic_inc(&bt->wake_index);
 		wake_up(&bs->wait);
-	} else if (wait_cnt < 0) {
-		wait_cnt = atomic_inc_return(&bs->wait_cnt);
-		if (!wait_cnt)
-			goto wake;
 	}
 }
 
@@ -392,45 +389,37 @@ void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag,
 		__blk_mq_put_reserved_tag(tags, tag);
 }
 
-static void bt_for_each_free(struct blk_mq_bitmap_tags *bt,
-			     unsigned long *free_map, unsigned int off)
+static void bt_for_each(struct blk_mq_hw_ctx *hctx,
+		struct blk_mq_bitmap_tags *bt, unsigned int off,
+		busy_iter_fn *fn, void *data, bool reserved)
 {
-	int i;
+	struct request *rq;
+	int bit, i;
 
 	for (i = 0; i < bt->map_nr; i++) {
 		struct blk_align_bitmap *bm = &bt->map[i];
-		int bit = 0;
 
-		do {
-			bit = find_next_zero_bit(&bm->word, bm->depth, bit);
-			if (bit >= bm->depth)
-				break;
-
-			__set_bit(bit + off, free_map);
-			bit++;
-		} while (1);
+		for (bit = find_first_bit(&bm->word, bm->depth);
+		     bit < bm->depth;
+		     bit = find_next_bit(&bm->word, bm->depth, bit + 1)) {
+		     	rq = blk_mq_tag_to_rq(hctx->tags, off + bit);
+			if (rq->q == hctx->queue)
+				fn(hctx, rq, data, reserved);
+		}
 
 		off += (1 << bt->bits_per_word);
 	}
 }
 
-void blk_mq_tag_busy_iter(struct blk_mq_tags *tags,
-			  void (*fn)(void *, unsigned long *), void *data)
+void blk_mq_tag_busy_iter(struct blk_mq_hw_ctx *hctx, busy_iter_fn *fn,
+		void *priv)
 {
-	unsigned long *tag_map;
-	size_t map_size;
-
-	map_size = ALIGN(tags->nr_tags, BITS_PER_LONG) / BITS_PER_LONG;
-	tag_map = kzalloc(map_size * sizeof(unsigned long), GFP_ATOMIC);
-	if (!tag_map)
-		return;
+	struct blk_mq_tags *tags = hctx->tags;
 
-	bt_for_each_free(&tags->bitmap_tags, tag_map, tags->nr_reserved_tags);
 	if (tags->nr_reserved_tags)
-		bt_for_each_free(&tags->breserved_tags, tag_map, 0);
-
-	fn(data, tag_map);
-	kfree(tag_map);
+		bt_for_each(hctx, &tags->breserved_tags, 0, fn, priv, true);
+	bt_for_each(hctx, &tags->bitmap_tags, tags->nr_reserved_tags, fn, priv,
+			false);
 }
 EXPORT_SYMBOL(blk_mq_tag_busy_iter);
 
@@ -463,8 +452,8 @@ static void bt_update_count(struct blk_mq_bitmap_tags *bt,
 	}
 
 	bt->wake_cnt = BT_WAIT_BATCH;
-	if (bt->wake_cnt > depth / 4)
-		bt->wake_cnt = max(1U, depth / 4);
+	if (bt->wake_cnt > depth / BT_WAIT_QUEUES)
+		bt->wake_cnt = max(1U, depth / BT_WAIT_QUEUES);
 
 	bt->depth = depth;
 }
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 38f4a165640d..68929bad9a6a 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -20,6 +20,7 @@
 #include <linux/cache.h>
 #include <linux/sched/sysctl.h>
 #include <linux/delay.h>
+#include <linux/crash_dump.h>
 
 #include <trace/events/block.h>
 
@@ -223,9 +224,11 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp,
 	struct blk_mq_hw_ctx *hctx;
 	struct request *rq;
 	struct blk_mq_alloc_data alloc_data;
+	int ret;
 
-	if (blk_mq_queue_enter(q))
-		return NULL;
+	ret = blk_mq_queue_enter(q);
+	if (ret)
+		return ERR_PTR(ret);
 
 	ctx = blk_mq_get_ctx(q);
 	hctx = q->mq_ops->map_queue(q, ctx->cpu);
@@ -245,6 +248,8 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp,
 		ctx = alloc_data.ctx;
 	}
 	blk_mq_put_ctx(ctx);
+	if (!rq)
+		return ERR_PTR(-EWOULDBLOCK);
 	return rq;
 }
 EXPORT_SYMBOL(blk_mq_alloc_request);
@@ -276,27 +281,7 @@ void blk_mq_free_request(struct request *rq)
 	__blk_mq_free_request(hctx, ctx, rq);
 }
 
-/*
- * Clone all relevant state from a request that has been put on hold in
- * the flush state machine into the preallocated flush request that hangs
- * off the request queue.
- *
- * For a driver the flush request should be invisible, that's why we are
- * impersonating the original request here.
- */
-void blk_mq_clone_flush_request(struct request *flush_rq,
-		struct request *orig_rq)
-{
-	struct blk_mq_hw_ctx *hctx =
-		orig_rq->q->mq_ops->map_queue(orig_rq->q, orig_rq->mq_ctx->cpu);
-
-	flush_rq->mq_ctx = orig_rq->mq_ctx;
-	flush_rq->tag = orig_rq->tag;
-	memcpy(blk_mq_rq_to_pdu(flush_rq), blk_mq_rq_to_pdu(orig_rq),
-		hctx->cmd_size);
-}
-
-inline void __blk_mq_end_io(struct request *rq, int error)
+inline void __blk_mq_end_request(struct request *rq, int error)
 {
 	blk_account_io_done(rq);
 
@@ -308,15 +293,15 @@ inline void __blk_mq_end_io(struct request *rq, int error)
 		blk_mq_free_request(rq);
 	}
 }
-EXPORT_SYMBOL(__blk_mq_end_io);
+EXPORT_SYMBOL(__blk_mq_end_request);
 
-void blk_mq_end_io(struct request *rq, int error)
+void blk_mq_end_request(struct request *rq, int error)
 {
 	if (blk_update_request(rq, error, blk_rq_bytes(rq)))
 		BUG();
-	__blk_mq_end_io(rq, error);
+	__blk_mq_end_request(rq, error);
 }
-EXPORT_SYMBOL(blk_mq_end_io);
+EXPORT_SYMBOL(blk_mq_end_request);
 
 static void __blk_mq_complete_request_remote(void *data)
 {
@@ -356,7 +341,7 @@ void __blk_mq_complete_request(struct request *rq)
 	struct request_queue *q = rq->q;
 
 	if (!q->softirq_done_fn)
-		blk_mq_end_io(rq, rq->errors);
+		blk_mq_end_request(rq, rq->errors);
 	else
 		blk_mq_ipi_complete_request(rq);
 }
@@ -380,7 +365,7 @@ void blk_mq_complete_request(struct request *rq)
 }
 EXPORT_SYMBOL(blk_mq_complete_request);
 
-static void blk_mq_start_request(struct request *rq, bool last)
+void blk_mq_start_request(struct request *rq)
 {
 	struct request_queue *q = rq->q;
 
@@ -417,35 +402,24 @@ static void blk_mq_start_request(struct request *rq, bool last)
 		 */
 		rq->nr_phys_segments++;
 	}
-
-	/*
-	 * Flag the last request in the series so that drivers know when IO
-	 * should be kicked off, if they don't do it on a per-request basis.
-	 *
-	 * Note: the flag isn't the only condition drivers should do kick off.
-	 * If drive is busy, the last request might not have the bit set.
-	 */
-	if (last)
-		rq->cmd_flags |= REQ_END;
 }
+EXPORT_SYMBOL(blk_mq_start_request);
 
 static void __blk_mq_requeue_request(struct request *rq)
 {
 	struct request_queue *q = rq->q;
 
 	trace_block_rq_requeue(q, rq);
-	clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
-
-	rq->cmd_flags &= ~REQ_END;
 
-	if (q->dma_drain_size && blk_rq_bytes(rq))
-		rq->nr_phys_segments--;
+	if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
+		if (q->dma_drain_size && blk_rq_bytes(rq))
+			rq->nr_phys_segments--;
+	}
 }
 
 void blk_mq_requeue_request(struct request *rq)
 {
 	__blk_mq_requeue_request(rq);
-	blk_clear_rq_complete(rq);
 
 	BUG_ON(blk_queued_rq(rq));
 	blk_mq_add_to_requeue_list(rq, true);
@@ -514,78 +488,35 @@ void blk_mq_kick_requeue_list(struct request_queue *q)
 }
 EXPORT_SYMBOL(blk_mq_kick_requeue_list);
 
-static inline bool is_flush_request(struct request *rq, unsigned int tag)
+static inline bool is_flush_request(struct request *rq,
+		struct blk_flush_queue *fq, unsigned int tag)
 {
 	return ((rq->cmd_flags & REQ_FLUSH_SEQ) &&
-			rq->q->flush_rq->tag == tag);
+			fq->flush_rq->tag == tag);
 }
 
 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
 {
 	struct request *rq = tags->rqs[tag];
+	/* mq_ctx of flush rq is always cloned from the corresponding req */
+	struct blk_flush_queue *fq = blk_get_flush_queue(rq->q, rq->mq_ctx);
 
-	if (!is_flush_request(rq, tag))
+	if (!is_flush_request(rq, fq, tag))
 		return rq;
 
-	return rq->q->flush_rq;
+	return fq->flush_rq;
 }
 EXPORT_SYMBOL(blk_mq_tag_to_rq);
 
 struct blk_mq_timeout_data {
-	struct blk_mq_hw_ctx *hctx;
-	unsigned long *next;
-	unsigned int *next_set;
+	unsigned long next;
+	unsigned int next_set;
 };
 
-static void blk_mq_timeout_check(void *__data, unsigned long *free_tags)
+void blk_mq_rq_timed_out(struct request *req, bool reserved)
 {
-	struct blk_mq_timeout_data *data = __data;
-	struct blk_mq_hw_ctx *hctx = data->hctx;
-	unsigned int tag;
-
-	 /* It may not be in flight yet (this is where
-	 * the REQ_ATOMIC_STARTED flag comes in). The requests are
-	 * statically allocated, so we know it's always safe to access the
-	 * memory associated with a bit offset into ->rqs[].
-	 */
-	tag = 0;
-	do {
-		struct request *rq;
-
-		tag = find_next_zero_bit(free_tags, hctx->tags->nr_tags, tag);
-		if (tag >= hctx->tags->nr_tags)
-			break;
-
-		rq = blk_mq_tag_to_rq(hctx->tags, tag++);
-		if (rq->q != hctx->queue)
-			continue;
-		if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
-			continue;
-
-		blk_rq_check_expired(rq, data->next, data->next_set);
-	} while (1);
-}
-
-static void blk_mq_hw_ctx_check_timeout(struct blk_mq_hw_ctx *hctx,
-					unsigned long *next,
-					unsigned int *next_set)
-{
-	struct blk_mq_timeout_data data = {
-		.hctx		= hctx,
-		.next		= next,
-		.next_set	= next_set,
-	};
-
-	/*
-	 * Ask the tagging code to iterate busy requests, so we can
-	 * check them for timeout.
-	 */
-	blk_mq_tag_busy_iter(hctx->tags, blk_mq_timeout_check, &data);
-}
-
-static enum blk_eh_timer_return blk_mq_rq_timed_out(struct request *rq)
-{
-	struct request_queue *q = rq->q;
+	struct blk_mq_ops *ops = req->q->mq_ops;
+	enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER;
 
 	/*
 	 * We know that complete is set at this point. If STARTED isn't set
@@ -596,21 +527,54 @@ static enum blk_eh_timer_return blk_mq_rq_timed_out(struct request *rq)
 	 * we both flags will get cleared. So check here again, and ignore
 	 * a timeout event with a request that isn't active.
 	 */
-	if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
-		return BLK_EH_NOT_HANDLED;
+	if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags))
+		return;
+
+	if (ops->timeout)
+		ret = ops->timeout(req, reserved);
+
+	switch (ret) {
+	case BLK_EH_HANDLED:
+		__blk_mq_complete_request(req);
+		break;
+	case BLK_EH_RESET_TIMER:
+		blk_add_timer(req);
+		blk_clear_rq_complete(req);
+		break;
+	case BLK_EH_NOT_HANDLED:
+		break;
+	default:
+		printk(KERN_ERR "block: bad eh return: %d\n", ret);
+		break;
+	}
+}
+		
+static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
+		struct request *rq, void *priv, bool reserved)
+{
+	struct blk_mq_timeout_data *data = priv;
 
-	if (!q->mq_ops->timeout)
-		return BLK_EH_RESET_TIMER;
+	if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
+		return;
 
-	return q->mq_ops->timeout(rq);
+	if (time_after_eq(jiffies, rq->deadline)) {
+		if (!blk_mark_rq_complete(rq))
+			blk_mq_rq_timed_out(rq, reserved);
+	} else if (!data->next_set || time_after(data->next, rq->deadline)) {
+		data->next = rq->deadline;
+		data->next_set = 1;
+	}
 }
 
-static void blk_mq_rq_timer(unsigned long data)
+static void blk_mq_rq_timer(unsigned long priv)
 {
-	struct request_queue *q = (struct request_queue *) data;
+	struct request_queue *q = (struct request_queue *)priv;
+	struct blk_mq_timeout_data data = {
+		.next		= 0,
+		.next_set	= 0,
+	};
 	struct blk_mq_hw_ctx *hctx;
-	unsigned long next = 0;
-	int i, next_set = 0;
+	int i;
 
 	queue_for_each_hw_ctx(q, hctx, i) {
 		/*
@@ -620,12 +584,12 @@ static void blk_mq_rq_timer(unsigned long data)
 		if (!hctx->nr_ctx || !hctx->tags)
 			continue;
 
-		blk_mq_hw_ctx_check_timeout(hctx, &next, &next_set);
+		blk_mq_tag_busy_iter(hctx, blk_mq_check_expired, &data);
 	}
 
-	if (next_set) {
-		next = blk_rq_timeout(round_jiffies_up(next));
-		mod_timer(&q->timeout, next);
+	if (data.next_set) {
+		data.next = blk_rq_timeout(round_jiffies_up(data.next));
+		mod_timer(&q->timeout, data.next);
 	} else {
 		queue_for_each_hw_ctx(q, hctx, i)
 			blk_mq_tag_idle(hctx);
@@ -751,9 +715,7 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
 		rq = list_first_entry(&rq_list, struct request, queuelist);
 		list_del_init(&rq->queuelist);
 
-		blk_mq_start_request(rq, list_empty(&rq_list));
-
-		ret = q->mq_ops->queue_rq(hctx, rq);
+		ret = q->mq_ops->queue_rq(hctx, rq, list_empty(&rq_list));
 		switch (ret) {
 		case BLK_MQ_RQ_QUEUE_OK:
 			queued++;
@@ -766,7 +728,7 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
 			pr_err("blk-mq: bad return on queue: %d\n", ret);
 		case BLK_MQ_RQ_QUEUE_ERROR:
 			rq->errors = -EIO;
-			blk_mq_end_io(rq, rq->errors);
+			blk_mq_end_request(rq, rq->errors);
 			break;
 		}
 
@@ -1194,14 +1156,13 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
 		int ret;
 
 		blk_mq_bio_to_request(rq, bio);
-		blk_mq_start_request(rq, true);
 
 		/*
 		 * For OK queue, we are done. For error, kill it. Any other
 		 * error (busy), just add it to our list as we previously
 		 * would have done
 		 */
-		ret = q->mq_ops->queue_rq(data.hctx, rq);
+		ret = q->mq_ops->queue_rq(data.hctx, rq, true);
 		if (ret == BLK_MQ_RQ_QUEUE_OK)
 			goto done;
 		else {
@@ -1209,7 +1170,7 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
 
 			if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
 				rq->errors = -EIO;
-				blk_mq_end_io(rq, rq->errors);
+				blk_mq_end_request(rq, rq->errors);
 				goto done;
 			}
 		}
@@ -1531,6 +1492,28 @@ static int blk_mq_hctx_notify(void *data, unsigned long action,
 	return NOTIFY_OK;
 }
 
+static void blk_mq_exit_hctx(struct request_queue *q,
+		struct blk_mq_tag_set *set,
+		struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
+{
+	unsigned flush_start_tag = set->queue_depth;
+
+	blk_mq_tag_idle(hctx);
+
+	if (set->ops->exit_request)
+		set->ops->exit_request(set->driver_data,
+				       hctx->fq->flush_rq, hctx_idx,
+				       flush_start_tag + hctx_idx);
+
+	if (set->ops->exit_hctx)
+		set->ops->exit_hctx(hctx, hctx_idx);
+
+	blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
+	blk_free_flush_queue(hctx->fq);
+	kfree(hctx->ctxs);
+	blk_mq_free_bitmap(&hctx->ctx_map);
+}
+
 static void blk_mq_exit_hw_queues(struct request_queue *q,
 		struct blk_mq_tag_set *set, int nr_queue)
 {
@@ -1540,17 +1523,8 @@ static void blk_mq_exit_hw_queues(struct request_queue *q,
 	queue_for_each_hw_ctx(q, hctx, i) {
 		if (i == nr_queue)
 			break;
-
-		blk_mq_tag_idle(hctx);
-
-		if (set->ops->exit_hctx)
-			set->ops->exit_hctx(hctx, i);
-
-		blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
-		kfree(hctx->ctxs);
-		blk_mq_free_bitmap(&hctx->ctx_map);
+		blk_mq_exit_hctx(q, set, hctx, i);
 	}
-
 }
 
 static void blk_mq_free_hw_queues(struct request_queue *q,
@@ -1565,53 +1539,88 @@ static void blk_mq_free_hw_queues(struct request_queue *q,
 	}
 }
 
-static int blk_mq_init_hw_queues(struct request_queue *q,
-		struct blk_mq_tag_set *set)
+static int blk_mq_init_hctx(struct request_queue *q,
+		struct blk_mq_tag_set *set,
+		struct blk_mq_hw_ctx *hctx, unsigned hctx_idx)
 {
-	struct blk_mq_hw_ctx *hctx;
-	unsigned int i;
+	int node;
+	unsigned flush_start_tag = set->queue_depth;
+
+	node = hctx->numa_node;
+	if (node == NUMA_NO_NODE)
+		node = hctx->numa_node = set->numa_node;
+
+	INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn);
+	INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn);
+	spin_lock_init(&hctx->lock);
+	INIT_LIST_HEAD(&hctx->dispatch);
+	hctx->queue = q;
+	hctx->queue_num = hctx_idx;
+	hctx->flags = set->flags;
+	hctx->cmd_size = set->cmd_size;
+
+	blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
+					blk_mq_hctx_notify, hctx);
+	blk_mq_register_cpu_notifier(&hctx->cpu_notifier);
+
+	hctx->tags = set->tags[hctx_idx];
 
 	/*
-	 * Initialize hardware queues
+	 * Allocate space for all possible cpus to avoid allocation at
+	 * runtime
 	 */
-	queue_for_each_hw_ctx(q, hctx, i) {
-		int node;
+	hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
+					GFP_KERNEL, node);
+	if (!hctx->ctxs)
+		goto unregister_cpu_notifier;
 
-		node = hctx->numa_node;
-		if (node == NUMA_NO_NODE)
-			node = hctx->numa_node = set->numa_node;
+	if (blk_mq_alloc_bitmap(&hctx->ctx_map, node))
+		goto free_ctxs;
 
-		INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn);
-		INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn);
-		spin_lock_init(&hctx->lock);
-		INIT_LIST_HEAD(&hctx->dispatch);
-		hctx->queue = q;
-		hctx->queue_num = i;
-		hctx->flags = set->flags;
-		hctx->cmd_size = set->cmd_size;
+	hctx->nr_ctx = 0;
 
-		blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
-						blk_mq_hctx_notify, hctx);
-		blk_mq_register_cpu_notifier(&hctx->cpu_notifier);
+	if (set->ops->init_hctx &&
+	    set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
+		goto free_bitmap;
 
-		hctx->tags = set->tags[i];
+	hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size);
+	if (!hctx->fq)
+		goto exit_hctx;
 
-		/*
-		 * Allocate space for all possible cpus to avoid allocation at
-		 * runtime
-		 */
-		hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
-						GFP_KERNEL, node);
-		if (!hctx->ctxs)
-			break;
+	if (set->ops->init_request &&
+	    set->ops->init_request(set->driver_data,
+				   hctx->fq->flush_rq, hctx_idx,
+				   flush_start_tag + hctx_idx, node))
+		goto free_fq;
 
-		if (blk_mq_alloc_bitmap(&hctx->ctx_map, node))
-			break;
+	return 0;
 
-		hctx->nr_ctx = 0;
+ free_fq:
+	kfree(hctx->fq);
+ exit_hctx:
+	if (set->ops->exit_hctx)
+		set->ops->exit_hctx(hctx, hctx_idx);
+ free_bitmap:
+	blk_mq_free_bitmap(&hctx->ctx_map);
+ free_ctxs:
+	kfree(hctx->ctxs);
+ unregister_cpu_notifier:
+	blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
+
+	return -1;
+}
+
+static int blk_mq_init_hw_queues(struct request_queue *q,
+		struct blk_mq_tag_set *set)
+{
+	struct blk_mq_hw_ctx *hctx;
+	unsigned int i;
 
-		if (set->ops->init_hctx &&
-		    set->ops->init_hctx(hctx, set->driver_data, i))
+	/*
+	 * Initialize hardware queues
+	 */
+	queue_for_each_hw_ctx(q, hctx, i) {
+		if (blk_mq_init_hctx(q, set, hctx, i))
 			break;
 	}
 
@@ -1765,6 +1774,16 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 	if (!ctx)
 		return ERR_PTR(-ENOMEM);
 
+	/*
+	 * If a crashdump is active, then we are potentially in a very
+	 * memory constrained environment. Limit us to 1 queue and
+	 * 64 tags to prevent using too much memory.
+	 */
+	if (is_kdump_kernel()) {
+		set->nr_hw_queues = 1;
+		set->queue_depth = min(64U, set->queue_depth);
+	}
+
 	hctxs = kmalloc_node(set->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL,
 			set->numa_node);
 
@@ -1783,7 +1802,8 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 		if (!hctxs[i])
 			goto err_hctxs;
 
-		if (!zalloc_cpumask_var(&hctxs[i]->cpumask, GFP_KERNEL))
+		if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL,
+						node))
 			goto err_hctxs;
 
 		atomic_set(&hctxs[i]->nr_active, 0);
@@ -1830,7 +1850,6 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 	else
 		blk_queue_make_request(q, blk_sq_make_request);
 
-	blk_queue_rq_timed_out(q, blk_mq_rq_timed_out);
 	if (set->timeout)
 		blk_queue_rq_timeout(q, set->timeout);
 
@@ -1842,17 +1861,10 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 	if (set->ops->complete)
 		blk_queue_softirq_done(q, set->ops->complete);
 
-	blk_mq_init_flush(q);
 	blk_mq_init_cpu_queues(q, set->nr_hw_queues);
 
-	q->flush_rq = kzalloc(round_up(sizeof(struct request) +
-				set->cmd_size, cache_line_size()),
-				GFP_KERNEL);
-	if (!q->flush_rq)
-		goto err_hw;
-
 	if (blk_mq_init_hw_queues(q, set))
-		goto err_flush_rq;
+		goto err_hw;
 
 	mutex_lock(&all_q_mutex);
 	list_add_tail(&q->all_q_node, &all_q_list);
@@ -1864,8 +1876,6 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 
 	return q;
 
-err_flush_rq:
-	kfree(q->flush_rq);
 err_hw:
 	blk_cleanup_queue(q);
 err_hctxs:
diff --git a/block/blk-mq.h b/block/blk-mq.h
index ca4964a6295d..d567d5283ffa 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -27,7 +27,6 @@ struct blk_mq_ctx {
 
 void __blk_mq_complete_request(struct request *rq);
 void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
-void blk_mq_init_flush(struct request_queue *q);
 void blk_mq_freeze_queue(struct request_queue *q);
 void blk_mq_free_queue(struct request_queue *q);
 void blk_mq_clone_flush_request(struct request *flush_rq,
@@ -60,6 +59,8 @@ extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
 extern int blk_mq_sysfs_register(struct request_queue *q);
 extern void blk_mq_sysfs_unregister(struct request_queue *q);
 
+extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
+
 /*
  * Basic implementation of sparser bitmap, allowing the user to spread
  * the bits over more cachelines.
diff --git a/block/blk-settings.c b/block/blk-settings.c
index f1a1795a5683..aa02247d227e 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -574,7 +574,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 		bottom = max(b->physical_block_size, b->io_min) + alignment;
 
 		/* Verify that top and bottom intervals line up */
-		if (max(top, bottom) & (min(top, bottom) - 1)) {
+		if (max(top, bottom) % min(top, bottom)) {
 			t->misaligned = 1;
 			ret = -1;
 		}
@@ -619,7 +619,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 
 	/* Find lowest common alignment_offset */
 	t->alignment_offset = lcm(t->alignment_offset, alignment)
-		& (max(t->physical_block_size, t->io_min) - 1);
+		% max(t->physical_block_size, t->io_min);
 
 	/* Verify that new alignment_offset is on a logical block boundary */
 	if (t->alignment_offset & (t->logical_block_size - 1)) {
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 521ae9089c50..1fac43408911 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -519,8 +519,8 @@ static void blk_release_queue(struct kobject *kobj)
 
 	if (q->mq_ops)
 		blk_mq_free_queue(q);
-
-	kfree(q->flush_rq);
+	else
+		blk_free_flush_queue(q->fq);
 
 	blk_trace_shutdown(q);
 
diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index 95a09590ccfd..56c025894cdf 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -90,10 +90,7 @@ static void blk_rq_timed_out(struct request *req)
 	switch (ret) {
 	case BLK_EH_HANDLED:
 		/* Can we use req->errors here? */
-		if (q->mq_ops)
-			__blk_mq_complete_request(req);
-		else
-			__blk_complete_request(req);
+		__blk_complete_request(req);
 		break;
 	case BLK_EH_RESET_TIMER:
 		blk_add_timer(req);
@@ -113,7 +110,7 @@ static void blk_rq_timed_out(struct request *req)
 	}
 }
 
-void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout,
+static void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout,
 			  unsigned int *next_set)
 {
 	if (time_after_eq(jiffies, rq->deadline)) {
@@ -162,7 +159,10 @@ void blk_abort_request(struct request *req)
 	if (blk_mark_rq_complete(req))
 		return;
 	blk_delete_timer(req);
-	blk_rq_timed_out(req);
+	if (req->q->mq_ops)
+		blk_mq_rq_timed_out(req, false);
+	else
+		blk_rq_timed_out(req);
 }
 EXPORT_SYMBOL_GPL(blk_abort_request);
 
@@ -190,7 +190,8 @@ void blk_add_timer(struct request *req)
 	struct request_queue *q = req->q;
 	unsigned long expiry;
 
-	if (!q->rq_timed_out_fn)
+	/* blk-mq has its own handler, so we don't need ->rq_timed_out_fn */
+	if (!q->mq_ops && !q->rq_timed_out_fn)
 		return;
 
 	BUG_ON(!list_empty(&req->timeout_list));
diff --git a/block/blk.h b/block/blk.h
index 6748c4f8d7a1..43b036185712 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -2,6 +2,8 @@
 #define BLK_INTERNAL_H
 
 #include <linux/idr.h>
+#include <linux/blk-mq.h>
+#include "blk-mq.h"
 
 /* Amount of time in which a process may batch requests */
 #define BLK_BATCH_TIME	(HZ/50UL)
@@ -12,16 +14,44 @@
 /* Max future timer expiry for timeouts */
 #define BLK_MAX_TIMEOUT		(5 * HZ)
 
+struct blk_flush_queue {
+	unsigned int		flush_queue_delayed:1;
+	unsigned int		flush_pending_idx:1;
+	unsigned int		flush_running_idx:1;
+	unsigned long		flush_pending_since;
+	struct list_head	flush_queue[2];
+	struct list_head	flush_data_in_flight;
+	struct request		*flush_rq;
+	spinlock_t		mq_flush_lock;
+};
+
 extern struct kmem_cache *blk_requestq_cachep;
 extern struct kmem_cache *request_cachep;
 extern struct kobj_type blk_queue_ktype;
 extern struct ida blk_queue_ida;
 
+static inline struct blk_flush_queue *blk_get_flush_queue(
+		struct request_queue *q, struct blk_mq_ctx *ctx)
+{
+	struct blk_mq_hw_ctx *hctx;
+
+	if (!q->mq_ops)
+		return q->fq;
+
+	hctx = q->mq_ops->map_queue(q, ctx->cpu);
+
+	return hctx->fq;
+}
+
 static inline void __blk_get_queue(struct request_queue *q)
 {
 	kobject_get(&q->kobj);
 }
 
+struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
+		int node, int cmd_size);
+void blk_free_flush_queue(struct blk_flush_queue *q);
+
 int blk_init_rl(struct request_list *rl, struct request_queue *q,
 		gfp_t gfp_mask);
 void blk_exit_rl(struct request_list *rl);
@@ -38,8 +68,6 @@ bool __blk_end_bidi_request(struct request *rq, int error,
 			    unsigned int nr_bytes, unsigned int bidi_bytes);
 
 void blk_rq_timed_out_timer(unsigned long data);
-void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout,
-			  unsigned int *next_set);
 unsigned long blk_rq_timeout(unsigned long timeout);
 void blk_add_timer(struct request *req);
 void blk_delete_timer(struct request *);
@@ -88,6 +116,7 @@ void blk_insert_flush(struct request *rq);
 static inline struct request *__elv_next_request(struct request_queue *q)
 {
 	struct request *rq;
+	struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
 
 	while (1) {
 		if (!list_empty(&q->queue_head)) {
@@ -110,9 +139,9 @@ static inline struct request *__elv_next_request(struct request_queue *q)
 		 * should be restarted later. Please see flush_end_io() for
 		 * details.
 		 */
-		if (q->flush_pending_idx != q->flush_running_idx &&
+		if (fq->flush_pending_idx != fq->flush_running_idx &&
 				!queue_flush_queueable(q)) {
-			q->flush_queue_delayed = 1;
+			fq->flush_queue_delayed = 1;
 			return NULL;
 		}
 		if (unlikely(blk_queue_bypass(q)) ||
diff --git a/block/bsg.c b/block/bsg.c
index ff46addde5d8..276e869e686c 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -270,8 +270,8 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
 	 * map scatter-gather elements separately and string them to request
 	 */
 	rq = blk_get_request(q, rw, GFP_KERNEL);
-	if (!rq)
-		return ERR_PTR(-ENOMEM);
+	if (IS_ERR(rq))
+		return rq;
 	blk_rq_set_block_pc(rq);
 
 	ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
@@ -285,8 +285,9 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
 		}
 
 		next_rq = blk_get_request(q, READ, GFP_KERNEL);
-		if (!next_rq) {
-			ret = -ENOMEM;
+		if (IS_ERR(next_rq)) {
+			ret = PTR_ERR(next_rq);
+			next_rq = NULL;
 			goto out;
 		}
 		rq->next_rq = next_rq;
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 3f31cf9508e6..6f2751d305de 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -299,7 +299,7 @@ struct cfq_io_cq {
 	struct cfq_ttime	ttime;
 	int			ioprio;		/* the current ioprio */
 #ifdef CONFIG_CFQ_GROUP_IOSCHED
-	uint64_t		blkcg_id;	/* the current blkcg ID */
+	uint64_t		blkcg_serial_nr; /* the current blkcg serial */
 #endif
 };
 
@@ -3547,17 +3547,17 @@ static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio)
 {
 	struct cfq_data *cfqd = cic_to_cfqd(cic);
 	struct cfq_queue *sync_cfqq;
-	uint64_t id;
+	uint64_t serial_nr;
 
 	rcu_read_lock();
-	id = bio_blkcg(bio)->id;
+	serial_nr = bio_blkcg(bio)->css.serial_nr;
 	rcu_read_unlock();
 
 	/*
 	 * Check whether blkcg has changed.  The condition may trigger
 	 * spuriously on a newly created cic but there's no harm.
 	 */
-	if (unlikely(!cfqd) || likely(cic->blkcg_id == id))
+	if (unlikely(!cfqd) || likely(cic->blkcg_serial_nr == serial_nr))
 		return;
 
 	sync_cfqq = cic_to_cfqq(cic, 1);
@@ -3571,7 +3571,7 @@ static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio)
 		cfq_put_queue(sync_cfqq);
 	}
 
-	cic->blkcg_id = id;
+	cic->blkcg_serial_nr = serial_nr;
 }
 #else
 static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { }
diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index 18b282ce361e..f678c733df40 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -709,8 +709,6 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 		if (!arg)
 			return -EINVAL;
 		bdi = blk_get_backing_dev_info(bdev);
-		if (bdi == NULL)
-			return -ENOTTY;
 		return compat_put_long(arg,
 				       (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
 	case BLKROGET: /* compatible */
@@ -731,8 +729,6 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 		if (!capable(CAP_SYS_ADMIN))
 			return -EACCES;
 		bdi = blk_get_backing_dev_info(bdev);
-		if (bdi == NULL)
-			return -ENOTTY;
 		bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
 		return 0;
 	case BLKGETSIZE:
diff --git a/block/ioctl.c b/block/ioctl.c
index d6cda8147c91..6c7bf903742f 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -356,8 +356,6 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 		if (!arg)
 			return -EINVAL;
 		bdi = blk_get_backing_dev_info(bdev);
-		if (bdi == NULL)
-			return -ENOTTY;
 		return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
 	case BLKROGET:
 		return put_int(arg, bdev_read_only(bdev) != 0);
@@ -386,8 +384,6 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 		if(!capable(CAP_SYS_ADMIN))
 			return -EACCES;
 		bdi = blk_get_backing_dev_info(bdev);
-		if (bdi == NULL)
-			return -ENOTTY;
 		bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
 		return 0;
 	case BLKBSZSET:
diff --git a/block/partitions/mac.c b/block/partitions/mac.c
index 76d8ba6379a9..c2c48ec64b27 100644
--- a/block/partitions/mac.c
+++ b/block/partitions/mac.c
@@ -81,7 +81,7 @@ int mac_partition(struct parsed_partitions *state)
 			be32_to_cpu(part->start_block) * (secsize/512),
 			be32_to_cpu(part->block_count) * (secsize/512));
 
-		if (!strnicmp(part->type, "Linux_RAID", 10))
+		if (!strncasecmp(part->type, "Linux_RAID", 10))
 			state->parts[slot].flags = ADDPART_FLAG_RAID;
 #ifdef CONFIG_PPC_PMAC
 		/*
@@ -100,7 +100,7 @@ int mac_partition(struct parsed_partitions *state)
 				goodness++;
 
 			if (strcasecmp(part->type, "Apple_UNIX_SVR2") == 0
-			    || (strnicmp(part->type, "Linux", 5) == 0
+			    || (strncasecmp(part->type, "Linux", 5) == 0
 			        && strcasecmp(part->type, "Linux_swap") != 0)) {
 				int i, l;
 
@@ -109,13 +109,13 @@ int mac_partition(struct parsed_partitions *state)
 				if (strcmp(part->name, "/") == 0)
 					goodness++;
 				for (i = 0; i <= l - 4; ++i) {
-					if (strnicmp(part->name + i, "root",
+					if (strncasecmp(part->name + i, "root",
 						     4) == 0) {
 						goodness += 2;
 						break;
 					}
 				}
-				if (strnicmp(part->name, "swap", 4) == 0)
+				if (strncasecmp(part->name, "swap", 4) == 0)
 					goodness--;
 			}
 
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 9b8eaeca6a79..abb2e65b24cc 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -316,8 +316,8 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
 
 	ret = -ENOMEM;
 	rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
-	if (!rq)
-		goto out;
+	if (IS_ERR(rq))
+		return PTR_ERR(rq);
 	blk_rq_set_block_pc(rq);
 
 	if (hdr->cmd_len > BLK_MAX_CDB) {
@@ -387,7 +387,6 @@ out_free_cdb:
 		kfree(rq->cmd);
 out_put_request:
 	blk_put_request(rq);
-out:
 	return ret;
 }
 
@@ -457,8 +456,8 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
 	}
 
 	rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_WAIT);
-	if (!rq) {
-		err = -ENOMEM;
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
 		goto error;
 	}
 	blk_rq_set_block_pc(rq);
@@ -548,6 +547,8 @@ static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
 	int err;
 
 	rq = blk_get_request(q, WRITE, __GFP_WAIT);
+	if (IS_ERR(rq))
+		return PTR_ERR(rq);
 	blk_rq_set_block_pc(rq);
 	rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
 	rq->cmd[0] = cmd;
diff --git a/block/t10-pi.c b/block/t10-pi.c
new file mode 100644
index 000000000000..24d6e9715318
--- /dev/null
+++ b/block/t10-pi.c
@@ -0,0 +1,197 @@
+/*
+ * t10_pi.c - Functions for generating and verifying T10 Protection
+ *	      Information.
+ *
+ * Copyright (C) 2007, 2008, 2014 Oracle Corporation
+ * Written by: Martin K. Petersen <martin.petersen@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
+ * USA.
+ *
+ */
+
+#include <linux/t10-pi.h>
+#include <linux/blkdev.h>
+#include <linux/crc-t10dif.h>
+#include <net/checksum.h>
+
+typedef __be16 (csum_fn) (void *, unsigned int);
+
+static const __be16 APP_ESCAPE = (__force __be16) 0xffff;
+static const __be32 REF_ESCAPE = (__force __be32) 0xffffffff;
+
+static __be16 t10_pi_crc_fn(void *data, unsigned int len)
+{
+	return cpu_to_be16(crc_t10dif(data, len));
+}
+
+static __be16 t10_pi_ip_fn(void *data, unsigned int len)
+{
+	return (__force __be16)ip_compute_csum(data, len);
+}
+
+/*
+ * Type 1 and Type 2 protection use the same format: 16 bit guard tag,
+ * 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref
+ * tag.
+ */
+static int t10_pi_generate(struct blk_integrity_iter *iter, csum_fn *fn,
+			   unsigned int type)
+{
+	unsigned int i;
+
+	for (i = 0 ; i < iter->data_size ; i += iter->interval) {
+		struct t10_pi_tuple *pi = iter->prot_buf;
+
+		pi->guard_tag = fn(iter->data_buf, iter->interval);
+		pi->app_tag = 0;
+
+		if (type == 1)
+			pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed));
+		else
+			pi->ref_tag = 0;
+
+		iter->data_buf += iter->interval;
+		iter->prot_buf += sizeof(struct t10_pi_tuple);
+		iter->seed++;
+	}
+
+	return 0;
+}
+
+static int t10_pi_verify(struct blk_integrity_iter *iter, csum_fn *fn,
+				unsigned int type)
+{
+	unsigned int i;
+
+	for (i = 0 ; i < iter->data_size ; i += iter->interval) {
+		struct t10_pi_tuple *pi = iter->prot_buf;
+		__be16 csum;
+
+		switch (type) {
+		case 1:
+		case 2:
+			if (pi->app_tag == APP_ESCAPE)
+				goto next;
+
+			if (be32_to_cpu(pi->ref_tag) !=
+			    lower_32_bits(iter->seed)) {
+				pr_err("%s: ref tag error at location %llu " \
+				       "(rcvd %u)\n", iter->disk_name,
+				       (unsigned long long)
+				       iter->seed, be32_to_cpu(pi->ref_tag));
+				return -EILSEQ;
+			}
+			break;
+		case 3:
+			if (pi->app_tag == APP_ESCAPE &&
+			    pi->ref_tag == REF_ESCAPE)
+				goto next;
+			break;
+		}
+
+		csum = fn(iter->data_buf, iter->interval);
+
+		if (pi->guard_tag != csum) {
+			pr_err("%s: guard tag error at sector %llu " \
+			       "(rcvd %04x, want %04x)\n", iter->disk_name,
+			       (unsigned long long)iter->seed,
+			       be16_to_cpu(pi->guard_tag), be16_to_cpu(csum));
+			return -EILSEQ;
+		}
+
+next:
+		iter->data_buf += iter->interval;
+		iter->prot_buf += sizeof(struct t10_pi_tuple);
+		iter->seed++;
+	}
+
+	return 0;
+}
+
+static int t10_pi_type1_generate_crc(struct blk_integrity_iter *iter)
+{
+	return t10_pi_generate(iter, t10_pi_crc_fn, 1);
+}
+
+static int t10_pi_type1_generate_ip(struct blk_integrity_iter *iter)
+{
+	return t10_pi_generate(iter, t10_pi_ip_fn, 1);
+}
+
+static int t10_pi_type1_verify_crc(struct blk_integrity_iter *iter)
+{
+	return t10_pi_verify(iter, t10_pi_crc_fn, 1);
+}
+
+static int t10_pi_type1_verify_ip(struct blk_integrity_iter *iter)
+{
+	return t10_pi_verify(iter, t10_pi_ip_fn, 1);
+}
+
+static int t10_pi_type3_generate_crc(struct blk_integrity_iter *iter)
+{
+	return t10_pi_generate(iter, t10_pi_crc_fn, 3);
+}
+
+static int t10_pi_type3_generate_ip(struct blk_integrity_iter *iter)
+{
+	return t10_pi_generate(iter, t10_pi_ip_fn, 3);
+}
+
+static int t10_pi_type3_verify_crc(struct blk_integrity_iter *iter)
+{
+	return t10_pi_verify(iter, t10_pi_crc_fn, 3);
+}
+
+static int t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
+{
+	return t10_pi_verify(iter, t10_pi_ip_fn, 3);
+}
+
+struct blk_integrity t10_pi_type1_crc = {
+	.name			= "T10-DIF-TYPE1-CRC",
+	.generate_fn		= t10_pi_type1_generate_crc,
+	.verify_fn		= t10_pi_type1_verify_crc,
+	.tuple_size		= sizeof(struct t10_pi_tuple),
+	.tag_size		= 0,
+};
+EXPORT_SYMBOL(t10_pi_type1_crc);
+
+struct blk_integrity t10_pi_type1_ip = {
+	.name			= "T10-DIF-TYPE1-IP",
+	.generate_fn		= t10_pi_type1_generate_ip,
+	.verify_fn		= t10_pi_type1_verify_ip,
+	.tuple_size		= sizeof(struct t10_pi_tuple),
+	.tag_size		= 0,
+};
+EXPORT_SYMBOL(t10_pi_type1_ip);
+
+struct blk_integrity t10_pi_type3_crc = {
+	.name			= "T10-DIF-TYPE3-CRC",
+	.generate_fn		= t10_pi_type3_generate_crc,
+	.verify_fn		= t10_pi_type3_verify_crc,
+	.tuple_size		= sizeof(struct t10_pi_tuple),
+	.tag_size		= 0,
+};
+EXPORT_SYMBOL(t10_pi_type3_crc);
+
+struct blk_integrity t10_pi_type3_ip = {
+	.name			= "T10-DIF-TYPE3-IP",
+	.generate_fn		= t10_pi_type3_generate_ip,
+	.verify_fn		= t10_pi_type3_verify_ip,
+	.tuple_size		= sizeof(struct t10_pi_tuple),
+	.tag_size		= 0,
+};
+EXPORT_SYMBOL(t10_pi_type3_ip);
author	Linus Torvalds <torvalds@linux-foundation.org>	2014-10-18 11:53:51 -0700
committer	Linus Torvalds <torvalds@linux-foundation.org>	2014-10-18 11:53:51 -0700
commit	d3dc366bbaf07c125561e90d6da4bb147741101a (patch)
tree	6eb7e79a8ec9df1fa705393c6d15ccea3d104661 /block
parent	511c41d9e6665a07aca94eb00983cf6d77dd87ff (diff)
parent	e19a8a0ad2d255316830ead05b59c5a704434cbb (diff)