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 ...
2014-10-18 11:53:51 -07:00 · 2014-10-18 11:53:51 -07:00 · d3dc366bba
commit d3dc366bba
parent 511c41d9e6 e19a8a0ad2
65 changed files with 1210 additions and 1172 deletions
--- a/Documentation/ABI/testing/sysfs-block
+++ b/Documentation/ABI/testing/sysfs-block
@ -53,6 +53,14 @@ Description:
 		512 bytes of data.


+What:		/sys/block/<disk>/integrity/device_is_integrity_capable
+Date:		July 2014
+Contact:	Martin K. Petersen <martin.petersen@oracle.com>
+Description:
+		Indicates whether a storage device is capable of storing
+		integrity metadata. Set if the device is T10 PI-capable.
+
+
 What:		/sys/block/<disk>/integrity/write_generate
 Date:		June 2008
 Contact:	Martin K. Petersen <martin.petersen@oracle.com>
--- a/Documentation/block/data-integrity.txt
+++ b/Documentation/block/data-integrity.txt
@ -129,11 +129,11 @@ interface for this is being worked on.
 4.1 BIO

 The data integrity patches add a new field to struct bio when
-CONFIG_BLK_DEV_INTEGRITY is enabled.  bio->bi_integrity is a pointer
-to a struct bip which contains the bio integrity payload.  Essentially
-a bip is a trimmed down struct bio which holds a bio_vec containing
-the integrity metadata and the required housekeeping information (bvec
-pool, vector count, etc.)
+CONFIG_BLK_DEV_INTEGRITY is enabled.  bio_integrity(bio) returns a
+pointer to a struct bip which contains the bio integrity payload.
+Essentially a bip is a trimmed down struct bio which holds a bio_vec
+containing the integrity metadata and the required housekeeping
+information (bvec pool, vector count, etc.)

 A kernel subsystem can enable data integrity protection on a bio by
 calling bio_integrity_alloc(bio).  This will allocate and attach the
@ -192,16 +192,6 @@ will require extra work due to the application tag.
    supported by the block device.


-    int bdev_integrity_enabled(block_device, int rw);
-
-      bdev_integrity_enabled() will return 1 if the block device
-      supports integrity metadata transfer for the data direction
-      specified in 'rw'.
-
-      bdev_integrity_enabled() honors the write_generate and
-      read_verify flags in sysfs and will respond accordingly.
-
-
    int bio_integrity_prep(bio);

      To generate IMD for WRITE and to set up buffers for READ, the
@ -216,36 +206,6 @@ will require extra work due to the application tag.
      bio_integrity_enabled() returned 1.


-    int bio_integrity_tag_size(bio);
-
-      If the filesystem wants to use the application tag space it will
-      first have to find out how much storage space is available.
-      Because tag space is generally limited (usually 2 bytes per
-      sector regardless of sector size), the integrity framework
-      supports interleaving the information between the sectors in an
-      I/O.
-
-      Filesystems can call bio_integrity_tag_size(bio) to find out how
-      many bytes of storage are available for that particular bio.
-
-      Another option is bdev_get_tag_size(block_device) which will
-      return the number of available bytes per hardware sector.
-
-
-    int bio_integrity_set_tag(bio, void *tag_buf, len);
-
-      After a successful return from bio_integrity_prep(),
-      bio_integrity_set_tag() can be used to attach an opaque tag
-      buffer to a bio.  Obviously this only makes sense if the I/O is
-      a WRITE.
-
-
-    int bio_integrity_get_tag(bio, void *tag_buf, len);
-
-      Similarly, at READ I/O completion time the filesystem can
-      retrieve the tag buffer using bio_integrity_get_tag().
-
-
 5.3 PASSING EXISTING INTEGRITY METADATA

    Filesystems that either generate their own integrity metadata or
@ -298,8 +258,6 @@ will require extra work due to the application tag.
            .name                   = "STANDARDSBODY-TYPE-VARIANT-CSUM",
            .generate_fn            = my_generate_fn,
       	    .verify_fn              = my_verify_fn,
-       	    .get_tag_fn             = my_get_tag_fn,
-       	    .set_tag_fn             = my_set_tag_fn,
 	    .tuple_size             = sizeof(struct my_tuple_size),
 	    .tag_size               = <tag bytes per hw sector>,
        };
@ -321,7 +279,5 @@ will require extra work due to the application tag.
      are available per hardware sector.  For DIF this is either 2 or
      0 depending on the value of the Control Mode Page ATO bit.

-      See 6.2 for a description of get_tag_fn and set_tag_fn.
-
 ----------------------------------------------------------------------
 2007-12-24 Martin K. Petersen <martin.petersen@oracle.com>
--- 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
--- 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
+
--- 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
@ -174,199 +158,92 @@ 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;

-	return bdev_integrity_enabled(bio->bi_bdev, bio_data_dir(bio));
+	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 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;
+	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;

-	if (operate)
-		sector = bio->bi_iter.bi_sector;
-	else
-		sector = bio->bi_integrity->bip_iter.bi_sector;
-
-	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;
-			}
+		iter.data_buf = kaddr + bv->bv_offset;
+		iter.data_size = bv->bv_len;
+
+		ret = proc_fn(&iter);
+		if (ret) {
+			kunmap_atomic(kaddr);
+			return ret;
 		}

-		sectors = bv->bv_len / bi->sector_size;
-		sector += sectors;
-		prot_buf += sectors * bi->tuple_size;
-
 		kunmap_atomic(kaddr);
 	}
 	return ret;
 }

-/**
- * 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);
@ -455,25 +334,12 @@ 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");
 }
--- 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
--- 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);
--- 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;
--- 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;

--- 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);

-	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;
+	/*
+	 * 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;
+	}

-	return blk_flush_queue_rq(q->flush_rq, false);
+	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(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)
 {
-	spin_lock_init(&q->mq_flush_lock);
+	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)
+{
+	/* bio based request queue hasn't flush queue */
+	if (!fq)
+		return;
+
+	kfree(fq->flush_rq);
+	kfree(fq);
 }
--- 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 & INTEGRITY_FLAG_WRITE) != 0);
+	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, "%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;

--- 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 */
--- 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;
+	struct blk_mq_tags *tags = hctx->tags;

-	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;
-
-	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;
 }
--- 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, &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 (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
-		return BLK_EH_NOT_HANDLED;
+		return;

-	if (!q->mq_ops->timeout)
-		return BLK_EH_RESET_TIMER;
-
-	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,
@ -1565,6 +1539,77 @@ static void blk_mq_free_hw_queues(struct request_queue *q,
 	}
 }

+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)
+{
+	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];
+
+	/*
+	 * 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)
+		goto unregister_cpu_notifier;
+
+	if (blk_mq_alloc_bitmap(&hctx->ctx_map, node))
+		goto free_ctxs;
+
+	hctx->nr_ctx = 0;
+
+	if (set->ops->init_hctx &&
+	    set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
+		goto free_bitmap;
+
+	hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size);
+	if (!hctx->fq)
+		goto exit_hctx;
+
+	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;
+
+	return 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)
 {
@ -1575,43 +1620,7 @@ static int blk_mq_init_hw_queues(struct request_queue *q,
 	 * Initialize hardware queues
 	 */
 	queue_for_each_hw_ctx(q, hctx, i) {
-		int node;
-
-		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 = i;
-		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[i];
-
-		/*
-		 * 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 (blk_mq_alloc_bitmap(&hctx->ctx_map, node))
-			break;
-
-		hctx->nr_ctx = 0;
-
-		if (set->ops->init_hctx &&
-		    set->ops->init_hctx(hctx, set->driver_data, 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:
--- 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.
--- 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)) {
--- 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);

--- 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));
--- 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)) ||
--- 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;
--- 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) { }
--- 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:
--- 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:
--- 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--;
 			}

--- 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;
--- a/block/t10-pi.c
+++ 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);
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@ -247,7 +247,7 @@ static void mtip_async_complete(struct mtip_port *port,
 	if (unlikely(cmd->unaligned))
 		up(&port->cmd_slot_unal);

-	blk_mq_end_io(rq, status ? -EIO : 0);
+	blk_mq_end_request(rq, status ? -EIO : 0);
 }

 /*
@ -3739,7 +3739,7 @@ static int mtip_submit_request(struct blk_mq_hw_ctx *hctx, struct request *rq)
 		int err;

 		err = mtip_send_trim(dd, blk_rq_pos(rq), blk_rq_sectors(rq));
-		blk_mq_end_io(rq, err);
+		blk_mq_end_request(rq, err);
 		return 0;
 	}

@ -3775,13 +3775,16 @@ static bool mtip_check_unal_depth(struct blk_mq_hw_ctx *hctx,
 	return false;
 }

-static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq)
+static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq,
+		bool last)
 {
 	int ret;

 	if (unlikely(mtip_check_unal_depth(hctx, rq)))
 		return BLK_MQ_RQ_QUEUE_BUSY;

+	blk_mq_start_request(rq);
+
 	ret = mtip_submit_request(hctx, rq);
 	if (likely(!ret))
 		return BLK_MQ_RQ_QUEUE_OK;
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@ -177,7 +177,7 @@ static void end_cmd(struct nullb_cmd *cmd)
 {
 	switch (queue_mode)  {
 	case NULL_Q_MQ:
-		blk_mq_end_io(cmd->rq, 0);
+		blk_mq_end_request(cmd->rq, 0);
 		return;
 	case NULL_Q_RQ:
 		INIT_LIST_HEAD(&cmd->rq->queuelist);
@ -313,13 +313,16 @@ static void null_request_fn(struct request_queue *q)
 	}
 }

-static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq)
+static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq,
+		bool last)
 {
 	struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq);

 	cmd->rq = rq;
 	cmd->nq = hctx->driver_data;

+	blk_mq_start_request(rq);
+
 	null_handle_cmd(cmd);
 	return BLK_MQ_RQ_QUEUE_OK;
 }
--- a/drivers/block/paride/pd.c
+++ b/drivers/block/paride/pd.c
@ -722,6 +722,8 @@ static int pd_special_command(struct pd_unit *disk,
 	int err = 0;

 	rq = blk_get_request(disk->gd->queue, READ, __GFP_WAIT);
+	if (IS_ERR(rq))
+		return PTR_ERR(rq);

 	rq->cmd_type = REQ_TYPE_SPECIAL;
 	rq->special = func;
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@ -704,6 +704,8 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *

 	rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
 			     WRITE : READ, __GFP_WAIT);
+	if (IS_ERR(rq))
+		return PTR_ERR(rq);
 	blk_rq_set_block_pc(rq);

 	if (cgc->buflen) {
--- a/drivers/block/sx8.c
+++ b/drivers/block/sx8.c
@ -568,7 +568,7 @@ static struct carm_request *carm_get_special(struct carm_host *host)
 		return NULL;

 	rq = blk_get_request(host->oob_q, WRITE /* bogus */, GFP_KERNEL);
-	if (!rq) {
+	if (IS_ERR(rq)) {
 		spin_lock_irqsave(&host->lock, flags);
 		carm_put_request(host, crq);
 		spin_unlock_irqrestore(&host->lock, flags);
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@ -129,7 +129,7 @@ static inline void virtblk_request_done(struct request *req)
 		req->errors = (error != 0);
 	}

-	blk_mq_end_io(req, error);
+	blk_mq_end_request(req, error);
 }

 static void virtblk_done(struct virtqueue *vq)
@ -158,14 +158,14 @@ static void virtblk_done(struct virtqueue *vq)
 	spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
 }

-static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req)
+static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req,
+		bool last)
 {
 	struct virtio_blk *vblk = hctx->queue->queuedata;
 	struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
 	unsigned long flags;
 	unsigned int num;
 	int qid = hctx->queue_num;
-	const bool last = (req->cmd_flags & REQ_END) != 0;
 	int err;
 	bool notify = false;

@ -199,6 +199,8 @@ static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req)
 		}
 	}

+	blk_mq_start_request(req);
+
 	num = blk_rq_map_sg(hctx->queue, vbr->req, vbr->sg);
 	if (num) {
 		if (rq_data_dir(vbr->req) == WRITE)
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@ -2180,8 +2180,8 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
 		len = nr * CD_FRAMESIZE_RAW;

 		rq = blk_get_request(q, READ, GFP_KERNEL);
-		if (!rq) {
-			ret = -ENOMEM;
+		if (IS_ERR(rq)) {
+			ret = PTR_ERR(rq);
 			break;
 		}
 		blk_rq_set_block_pc(rq);
--- a/drivers/ide/ide-park.c
+++ b/drivers/ide/ide-park.c
@ -46,7 +46,7 @@ static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
 	 * timeout has expired, so power management will be reenabled.
 	 */
 	rq = blk_get_request(q, READ, GFP_NOWAIT);
-	if (unlikely(!rq))
+	if (IS_ERR(rq))
 		goto out;

 	rq->cmd[0] = REQ_UNPARK_HEADS;
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@ -73,7 +73,6 @@ comment "SCSI support type (disk, tape, CD-ROM)"
 config BLK_DEV_SD
 	tristate "SCSI disk support"
 	depends on SCSI
-	select CRC_T10DIF if BLK_DEV_INTEGRITY
 	---help---
 	  If you want to use SCSI hard disks, Fibre Channel disks,
 	  Serial ATA (SATA) or Parallel ATA (PATA) hard disks,
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@ -115,7 +115,7 @@ static struct request *get_alua_req(struct scsi_device *sdev,

 	rq = blk_get_request(q, rw, GFP_NOIO);

-	if (!rq) {
+	if (IS_ERR(rq)) {
 		sdev_printk(KERN_INFO, sdev,
 			    "%s: blk_get_request failed\n", __func__);
 		return NULL;
--- a/drivers/scsi/device_handler/scsi_dh_emc.c
+++ b/drivers/scsi/device_handler/scsi_dh_emc.c
@ -275,7 +275,7 @@ static struct request *get_req(struct scsi_device *sdev, int cmd,

 	rq = blk_get_request(sdev->request_queue,
 			(cmd != INQUIRY) ? WRITE : READ, GFP_NOIO);
-	if (!rq) {
+	if (IS_ERR(rq)) {
 		sdev_printk(KERN_INFO, sdev, "get_req: blk_get_request failed");
 		return NULL;
 	}
--- a/drivers/scsi/device_handler/scsi_dh_hp_sw.c
+++ b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
@ -117,7 +117,7 @@ static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)

 retry:
 	req = blk_get_request(sdev->request_queue, WRITE, GFP_NOIO);
-	if (!req)
+	if (IS_ERR(req))
 		return SCSI_DH_RES_TEMP_UNAVAIL;

 	blk_rq_set_block_pc(req);
@ -247,7 +247,7 @@ static int hp_sw_start_stop(struct hp_sw_dh_data *h)
 	struct request *req;

 	req = blk_get_request(h->sdev->request_queue, WRITE, GFP_ATOMIC);
-	if (!req)
+	if (IS_ERR(req))
 		return SCSI_DH_RES_TEMP_UNAVAIL;

 	blk_rq_set_block_pc(req);
--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@ -274,7 +274,7 @@ static struct request *get_rdac_req(struct scsi_device *sdev,

 	rq = blk_get_request(q, rw, GFP_NOIO);

-	if (!rq) {
+	if (IS_ERR(rq)) {
 		sdev_printk(KERN_INFO, sdev,
 				"get_rdac_req: blk_get_request failed.\n");
 		return NULL;
--- a/drivers/scsi/osd/osd_initiator.c
+++ b/drivers/scsi/osd/osd_initiator.c
@ -1567,8 +1567,8 @@ static struct request *_make_request(struct request_queue *q, bool has_write,
 		struct request *req;

 		req = blk_get_request(q, has_write ? WRITE : READ, flags);
-		if (unlikely(!req))
-			return ERR_PTR(-ENOMEM);
+		if (IS_ERR(req))
+			return req;

 		blk_rq_set_block_pc(req);
 		return req;
--- a/drivers/scsi/osst.c
+++ b/drivers/scsi/osst.c
@ -362,7 +362,7 @@ static int osst_execute(struct osst_request *SRpnt, const unsigned char *cmd,
 	int write = (data_direction == DMA_TO_DEVICE);

 	req = blk_get_request(SRpnt->stp->device->request_queue, write, GFP_KERNEL);
-	if (!req)
+	if (IS_ERR(req))
 		return DRIVER_ERROR << 24;

 	blk_rq_set_block_pc(req);
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@ -1961,6 +1961,8 @@ static void scsi_eh_lock_door(struct scsi_device *sdev)
 	 * request becomes available
 	 */
 	req = blk_get_request(sdev->request_queue, READ, GFP_KERNEL);
+	if (IS_ERR(req))
+		return;

 	blk_rq_set_block_pc(req);

--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@ -221,7 +221,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 	int ret = DRIVER_ERROR << 24;

 	req = blk_get_request(sdev->request_queue, write, __GFP_WAIT);
-	if (!req)
+	if (IS_ERR(req))
 		return ret;
 	blk_rq_set_block_pc(req);

@ -715,7 +715,7 @@ static bool scsi_end_request(struct request *req, int error,

 	if (req->mq_ctx) {
 		/*
-		 * In the MQ case the command gets freed by __blk_mq_end_io,
+		 * In the MQ case the command gets freed by __blk_mq_end_request,
 		 * so we have to do all cleanup that depends on it earlier.
 		 *
 		 * We also can't kick the queues from irq context, so we
@ -723,7 +723,7 @@ static bool scsi_end_request(struct request *req, int error,
 		 */
 		scsi_mq_uninit_cmd(cmd);

-		__blk_mq_end_io(req, error);
+		__blk_mq_end_request(req, error);

 		if (scsi_target(sdev)->single_lun ||
 		    !list_empty(&sdev->host->starved_list))
@ -1847,6 +1847,8 @@ static int scsi_mq_prep_fn(struct request *req)
 		next_rq->special = bidi_sdb;
 	}

+	blk_mq_start_request(req);
+
 	return scsi_setup_cmnd(sdev, req);
 }

@ -1856,7 +1858,8 @@ static void scsi_mq_done(struct scsi_cmnd *cmd)
 	blk_mq_complete_request(cmd->request);
 }

-static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req)
+static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req,
+		bool last)
 {
 	struct request_queue *q = req->q;
 	struct scsi_device *sdev = q->queuedata;
@ -1880,11 +1883,14 @@ static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req)
 	if (!scsi_host_queue_ready(q, shost, sdev))
 		goto out_dec_target_busy;

+
 	if (!(req->cmd_flags & REQ_DONTPREP)) {
 		ret = prep_to_mq(scsi_mq_prep_fn(req));
 		if (ret)
 			goto out_dec_host_busy;
 		req->cmd_flags |= REQ_DONTPREP;
+	} else {
+		blk_mq_start_request(req);
 	}

 	scsi_init_cmd_errh(cmd);
@ -1931,6 +1937,14 @@ out:
 	return ret;
 }

+static enum blk_eh_timer_return scsi_timeout(struct request *req,
+		bool reserved)
+{
+	if (reserved)
+		return BLK_EH_RESET_TIMER;
+	return scsi_times_out(req);
+}
+
 static int scsi_init_request(void *data, struct request *rq,
 		unsigned int hctx_idx, unsigned int request_idx,
 		unsigned int numa_node)
@ -2042,7 +2056,7 @@ static struct blk_mq_ops scsi_mq_ops = {
 	.map_queue	= blk_mq_map_queue,
 	.queue_rq	= scsi_queue_rq,
 	.complete	= scsi_softirq_done,
-	.timeout	= scsi_times_out,
+	.timeout	= scsi_timeout,
 	.init_request	= scsi_init_request,
 	.exit_request	= scsi_exit_request,
 };
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@ -610,29 +610,44 @@ static void scsi_disk_put(struct scsi_disk *sdkp)
 	mutex_unlock(&sd_ref_mutex);
 }

-static void sd_prot_op(struct scsi_cmnd *scmd, unsigned int dif)
-{
-	unsigned int prot_op = SCSI_PROT_NORMAL;
-	unsigned int dix = scsi_prot_sg_count(scmd);

-	if (scmd->sc_data_direction == DMA_FROM_DEVICE) {
-		if (dif && dix)
-			prot_op = SCSI_PROT_READ_PASS;
-		else if (dif && !dix)
-			prot_op = SCSI_PROT_READ_STRIP;
-		else if (!dif && dix)
-			prot_op = SCSI_PROT_READ_INSERT;
-	} else {
-		if (dif && dix)
-			prot_op = SCSI_PROT_WRITE_PASS;
-		else if (dif && !dix)
-			prot_op = SCSI_PROT_WRITE_INSERT;
-		else if (!dif && dix)
-			prot_op = SCSI_PROT_WRITE_STRIP;
+
+static unsigned char sd_setup_protect_cmnd(struct scsi_cmnd *scmd,
+					   unsigned int dix, unsigned int dif)
+{
+	struct bio *bio = scmd->request->bio;
+	unsigned int prot_op = sd_prot_op(rq_data_dir(scmd->request), dix, dif);
+	unsigned int protect = 0;
+
+	if (dix) {				/* DIX Type 0, 1, 2, 3 */
+		if (bio_integrity_flagged(bio, BIP_IP_CHECKSUM))
+			scmd->prot_flags |= SCSI_PROT_IP_CHECKSUM;
+
+		if (bio_integrity_flagged(bio, BIP_CTRL_NOCHECK) == false)
+			scmd->prot_flags |= SCSI_PROT_GUARD_CHECK;
+	}
+
+	if (dif != SD_DIF_TYPE3_PROTECTION) {	/* DIX/DIF Type 0, 1, 2 */
+		scmd->prot_flags |= SCSI_PROT_REF_INCREMENT;
+
+		if (bio_integrity_flagged(bio, BIP_CTRL_NOCHECK) == false)
+			scmd->prot_flags |= SCSI_PROT_REF_CHECK;
+	}
+
+	if (dif) {				/* DIX/DIF Type 1, 2, 3 */
+		scmd->prot_flags |= SCSI_PROT_TRANSFER_PI;
+
+		if (bio_integrity_flagged(bio, BIP_DISK_NOCHECK))
+			protect = 3 << 5;	/* Disable target PI checking */
+		else
+			protect = 1 << 5;	/* Enable target PI checking */
 	}

 	scsi_set_prot_op(scmd, prot_op);
 	scsi_set_prot_type(scmd, dif);
+	scmd->prot_flags &= sd_prot_flag_mask(prot_op);
+
+	return protect;
 }

 static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
@ -893,7 +908,8 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 	sector_t block = blk_rq_pos(rq);
 	sector_t threshold;
 	unsigned int this_count = blk_rq_sectors(rq);
-	int ret, host_dif;
+	unsigned int dif, dix;
+	int ret;
 	unsigned char protect;

 	ret = scsi_init_io(SCpnt, GFP_ATOMIC);
@ -995,7 +1011,7 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 		SCpnt->cmnd[0] = WRITE_6;

 		if (blk_integrity_rq(rq))
-			sd_dif_prepare(rq, block, sdp->sector_size);
+			sd_dif_prepare(SCpnt);

 	} else if (rq_data_dir(rq) == READ) {
 		SCpnt->cmnd[0] = READ_6;
@ -1010,14 +1026,15 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 					"writing" : "reading", this_count,
 					blk_rq_sectors(rq)));

-	/* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
-	host_dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
-	if (host_dif)
-		protect = 1 << 5;
+	dix = scsi_prot_sg_count(SCpnt);
+	dif = scsi_host_dif_capable(SCpnt->device->host, sdkp->protection_type);
+
+	if (dif || dix)
+		protect = sd_setup_protect_cmnd(SCpnt, dix, dif);
 	else
 		protect = 0;

-	if (host_dif == SD_DIF_TYPE2_PROTECTION) {
+	if (protect && sdkp->protection_type == SD_DIF_TYPE2_PROTECTION) {
 		SCpnt->cmnd = mempool_alloc(sd_cdb_pool, GFP_ATOMIC);

 		if (unlikely(SCpnt->cmnd == NULL)) {
@ -1102,10 +1119,6 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 	}
 	SCpnt->sdb.length = this_count * sdp->sector_size;

-	/* If DIF or DIX is enabled, tell HBA how to handle request */
-	if (host_dif || scsi_prot_sg_count(SCpnt))
-		sd_prot_op(SCpnt, host_dif);
-
 	/*
 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
 	 * host adapter, it's safe to assume that we can at least transfer
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@ -166,6 +166,68 @@ enum sd_dif_target_protection_types {
 	SD_DIF_TYPE3_PROTECTION = 0x3,
 };

+/*
+ * Look up the DIX operation based on whether the command is read or
+ * write and whether dix and dif are enabled.
+ */
+static inline unsigned int sd_prot_op(bool write, bool dix, bool dif)
+{
+	/* Lookup table: bit 2 (write), bit 1 (dix), bit 0 (dif) */
+	const unsigned int ops[] = {	/* wrt dix dif */
+		SCSI_PROT_NORMAL,	/*  0	0   0  */
+		SCSI_PROT_READ_STRIP,	/*  0	0   1  */
+		SCSI_PROT_READ_INSERT,	/*  0	1   0  */
+		SCSI_PROT_READ_PASS,	/*  0	1   1  */
+		SCSI_PROT_NORMAL,	/*  1	0   0  */
+		SCSI_PROT_WRITE_INSERT, /*  1	0   1  */
+		SCSI_PROT_WRITE_STRIP,	/*  1	1   0  */
+		SCSI_PROT_WRITE_PASS,	/*  1	1   1  */
+	};
+
+	return ops[write << 2 | dix << 1 | dif];
+}
+
+/*
+ * Returns a mask of the protection flags that are valid for a given DIX
+ * operation.
+ */
+static inline unsigned int sd_prot_flag_mask(unsigned int prot_op)
+{
+	const unsigned int flag_mask[] = {
+		[SCSI_PROT_NORMAL]		= 0,
+
+		[SCSI_PROT_READ_STRIP]		= SCSI_PROT_TRANSFER_PI |
+						  SCSI_PROT_GUARD_CHECK |
+						  SCSI_PROT_REF_CHECK |
+						  SCSI_PROT_REF_INCREMENT,
+
+		[SCSI_PROT_READ_INSERT]		= SCSI_PROT_REF_INCREMENT |
+						  SCSI_PROT_IP_CHECKSUM,
+
+		[SCSI_PROT_READ_PASS]		= SCSI_PROT_TRANSFER_PI |
+						  SCSI_PROT_GUARD_CHECK |
+						  SCSI_PROT_REF_CHECK |
+						  SCSI_PROT_REF_INCREMENT |
+						  SCSI_PROT_IP_CHECKSUM,
+
+		[SCSI_PROT_WRITE_INSERT]	= SCSI_PROT_TRANSFER_PI |
+						  SCSI_PROT_REF_INCREMENT,
+
+		[SCSI_PROT_WRITE_STRIP]		= SCSI_PROT_GUARD_CHECK |
+						  SCSI_PROT_REF_CHECK |
+						  SCSI_PROT_REF_INCREMENT |
+						  SCSI_PROT_IP_CHECKSUM,
+
+		[SCSI_PROT_WRITE_PASS]		= SCSI_PROT_TRANSFER_PI |
+						  SCSI_PROT_GUARD_CHECK |
+						  SCSI_PROT_REF_CHECK |
+						  SCSI_PROT_REF_INCREMENT |
+						  SCSI_PROT_IP_CHECKSUM,
+	};
+
+	return flag_mask[prot_op];
+}
+
 /*
 * Data Integrity Field tuple.
 */
@ -178,7 +240,7 @@ struct sd_dif_tuple {
 #ifdef CONFIG_BLK_DEV_INTEGRITY

 extern void sd_dif_config_host(struct scsi_disk *);
-extern void sd_dif_prepare(struct request *rq, sector_t, unsigned int);
+extern void sd_dif_prepare(struct scsi_cmnd *scmd);
 extern void sd_dif_complete(struct scsi_cmnd *, unsigned int);

 #else /* CONFIG_BLK_DEV_INTEGRITY */
@ -186,7 +248,7 @@ extern void sd_dif_complete(struct scsi_cmnd *, unsigned int);
 static inline void sd_dif_config_host(struct scsi_disk *disk)
 {
 }
-static inline int sd_dif_prepare(struct request *rq, sector_t s, unsigned int a)
+static inline int sd_dif_prepare(struct scsi_cmnd *scmd)
 {
 	return 0;
 }
--- a/drivers/scsi/sd_dif.c
+++ b/drivers/scsi/sd_dif.c
@ -21,7 +21,7 @@
 */

 #include <linux/blkdev.h>
-#include <linux/crc-t10dif.h>
+#include <linux/t10-pi.h>

 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@ -33,268 +33,8 @@
 #include <scsi/scsi_ioctl.h>
 #include <scsi/scsicam.h>

-#include <net/checksum.h>
-
 #include "sd.h"

-typedef __u16 (csum_fn) (void *, unsigned int);
-
-static __u16 sd_dif_crc_fn(void *data, unsigned int len)
-{
-	return cpu_to_be16(crc_t10dif(data, len));
-}
-
-static __u16 sd_dif_ip_fn(void *data, unsigned int len)
-{
-	return 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.
- */
-static void sd_dif_type1_generate(struct blk_integrity_exchg *bix, csum_fn *fn)
-{
-	void *buf = bix->data_buf;
-	struct sd_dif_tuple *sdt = bix->prot_buf;
-	sector_t sector = bix->sector;
-	unsigned int i;
-
-	for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
-		sdt->guard_tag = fn(buf, bix->sector_size);
-		sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
-		sdt->app_tag = 0;
-
-		buf += bix->sector_size;
-		sector++;
-	}
-}
-
-static void sd_dif_type1_generate_crc(struct blk_integrity_exchg *bix)
-{
-	sd_dif_type1_generate(bix, sd_dif_crc_fn);
-}
-
-static void sd_dif_type1_generate_ip(struct blk_integrity_exchg *bix)
-{
-	sd_dif_type1_generate(bix, sd_dif_ip_fn);
-}
-
-static int sd_dif_type1_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
-{
-	void *buf = bix->data_buf;
-	struct sd_dif_tuple *sdt = bix->prot_buf;
-	sector_t sector = bix->sector;
-	unsigned int i;
-	__u16 csum;
-
-	for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
-		/* Unwritten sectors */
-		if (sdt->app_tag == 0xffff)
-			return 0;
-
-		if (be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
-			printk(KERN_ERR
-			       "%s: ref tag error on sector %lu (rcvd %u)\n",
-			       bix->disk_name, (unsigned long)sector,
-			       be32_to_cpu(sdt->ref_tag));
-			return -EIO;
-		}
-
-		csum = fn(buf, bix->sector_size);
-
-		if (sdt->guard_tag != csum) {
-			printk(KERN_ERR "%s: guard tag error on sector %lu " \
-			       "(rcvd %04x, data %04x)\n", bix->disk_name,
-			       (unsigned long)sector,
-			       be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
-			return -EIO;
-		}
-
-		buf += bix->sector_size;
-		sector++;
-	}
-
-	return 0;
-}
-
-static int sd_dif_type1_verify_crc(struct blk_integrity_exchg *bix)
-{
-	return sd_dif_type1_verify(bix, sd_dif_crc_fn);
-}
-
-static int sd_dif_type1_verify_ip(struct blk_integrity_exchg *bix)
-{
-	return sd_dif_type1_verify(bix, sd_dif_ip_fn);
-}
-
-/*
- * Functions for interleaving and deinterleaving application tags
- */
-static void sd_dif_type1_set_tag(void *prot, void *tag_buf, unsigned int sectors)
-{
-	struct sd_dif_tuple *sdt = prot;
-	u8 *tag = tag_buf;
-	unsigned int i, j;
-
-	for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
-		sdt->app_tag = tag[j] << 8 | tag[j+1];
-		BUG_ON(sdt->app_tag == 0xffff);
-	}
-}
-
-static void sd_dif_type1_get_tag(void *prot, void *tag_buf, unsigned int sectors)
-{
-	struct sd_dif_tuple *sdt = prot;
-	u8 *tag = tag_buf;
-	unsigned int i, j;
-
-	for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
-		tag[j] = (sdt->app_tag & 0xff00) >> 8;
-		tag[j+1] = sdt->app_tag & 0xff;
-	}
-}
-
-static struct blk_integrity dif_type1_integrity_crc = {
-	.name			= "T10-DIF-TYPE1-CRC",
-	.generate_fn		= sd_dif_type1_generate_crc,
-	.verify_fn		= sd_dif_type1_verify_crc,
-	.get_tag_fn		= sd_dif_type1_get_tag,
-	.set_tag_fn		= sd_dif_type1_set_tag,
-	.tuple_size		= sizeof(struct sd_dif_tuple),
-	.tag_size		= 0,
-};
-
-static struct blk_integrity dif_type1_integrity_ip = {
-	.name			= "T10-DIF-TYPE1-IP",
-	.generate_fn		= sd_dif_type1_generate_ip,
-	.verify_fn		= sd_dif_type1_verify_ip,
-	.get_tag_fn		= sd_dif_type1_get_tag,
-	.set_tag_fn		= sd_dif_type1_set_tag,
-	.tuple_size		= sizeof(struct sd_dif_tuple),
-	.tag_size		= 0,
-};
-
-
-/*
- * Type 3 protection has a 16-bit guard tag and 16 + 32 bits of opaque
- * tag space.
- */
-static void sd_dif_type3_generate(struct blk_integrity_exchg *bix, csum_fn *fn)
-{
-	void *buf = bix->data_buf;
-	struct sd_dif_tuple *sdt = bix->prot_buf;
-	unsigned int i;
-
-	for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
-		sdt->guard_tag = fn(buf, bix->sector_size);
-		sdt->ref_tag = 0;
-		sdt->app_tag = 0;
-
-		buf += bix->sector_size;
-	}
-}
-
-static void sd_dif_type3_generate_crc(struct blk_integrity_exchg *bix)
-{
-	sd_dif_type3_generate(bix, sd_dif_crc_fn);
-}
-
-static void sd_dif_type3_generate_ip(struct blk_integrity_exchg *bix)
-{
-	sd_dif_type3_generate(bix, sd_dif_ip_fn);
-}
-
-static int sd_dif_type3_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
-{
-	void *buf = bix->data_buf;
-	struct sd_dif_tuple *sdt = bix->prot_buf;
-	sector_t sector = bix->sector;
-	unsigned int i;
-	__u16 csum;
-
-	for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
-		/* Unwritten sectors */
-		if (sdt->app_tag == 0xffff && sdt->ref_tag == 0xffffffff)
-			return 0;
-
-		csum = fn(buf, bix->sector_size);
-
-		if (sdt->guard_tag != csum) {
-			printk(KERN_ERR "%s: guard tag error on sector %lu " \
-			       "(rcvd %04x, data %04x)\n", bix->disk_name,
-			       (unsigned long)sector,
-			       be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
-			return -EIO;
-		}
-
-		buf += bix->sector_size;
-		sector++;
-	}
-
-	return 0;
-}
-
-static int sd_dif_type3_verify_crc(struct blk_integrity_exchg *bix)
-{
-	return sd_dif_type3_verify(bix, sd_dif_crc_fn);
-}
-
-static int sd_dif_type3_verify_ip(struct blk_integrity_exchg *bix)
-{
-	return sd_dif_type3_verify(bix, sd_dif_ip_fn);
-}
-
-static void sd_dif_type3_set_tag(void *prot, void *tag_buf, unsigned int sectors)
-{
-	struct sd_dif_tuple *sdt = prot;
-	u8 *tag = tag_buf;
-	unsigned int i, j;
-
-	for (i = 0, j = 0 ; i < sectors ; i++, j += 6, sdt++) {
-		sdt->app_tag = tag[j] << 8 | tag[j+1];
-		sdt->ref_tag = tag[j+2] << 24 | tag[j+3] << 16 |
-			tag[j+4] << 8 | tag[j+5];
-	}
-}
-
-static void sd_dif_type3_get_tag(void *prot, void *tag_buf, unsigned int sectors)
-{
-	struct sd_dif_tuple *sdt = prot;
-	u8 *tag = tag_buf;
-	unsigned int i, j;
-
-	for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
-		tag[j] = (sdt->app_tag & 0xff00) >> 8;
-		tag[j+1] = sdt->app_tag & 0xff;
-		tag[j+2] = (sdt->ref_tag & 0xff000000) >> 24;
-		tag[j+3] = (sdt->ref_tag & 0xff0000) >> 16;
-		tag[j+4] = (sdt->ref_tag & 0xff00) >> 8;
-		tag[j+5] = sdt->ref_tag & 0xff;
-		BUG_ON(sdt->app_tag == 0xffff || sdt->ref_tag == 0xffffffff);
-	}
-}
-
-static struct blk_integrity dif_type3_integrity_crc = {
-	.name			= "T10-DIF-TYPE3-CRC",
-	.generate_fn		= sd_dif_type3_generate_crc,
-	.verify_fn		= sd_dif_type3_verify_crc,
-	.get_tag_fn		= sd_dif_type3_get_tag,
-	.set_tag_fn		= sd_dif_type3_set_tag,
-	.tuple_size		= sizeof(struct sd_dif_tuple),
-	.tag_size		= 0,
-};
-
-static struct blk_integrity dif_type3_integrity_ip = {
-	.name			= "T10-DIF-TYPE3-IP",
-	.generate_fn		= sd_dif_type3_generate_ip,
-	.verify_fn		= sd_dif_type3_verify_ip,
-	.get_tag_fn		= sd_dif_type3_get_tag,
-	.set_tag_fn		= sd_dif_type3_set_tag,
-	.tuple_size		= sizeof(struct sd_dif_tuple),
-	.tag_size		= 0,
-};
-
 /*
 * Configure exchange of protection information between OS and HBA.
 */
@ -316,22 +56,30 @@ void sd_dif_config_host(struct scsi_disk *sdkp)
 		return;

 	/* Enable DMA of protection information */
-	if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP)
+	if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP) {
 		if (type == SD_DIF_TYPE3_PROTECTION)
-			blk_integrity_register(disk, &dif_type3_integrity_ip);
+			blk_integrity_register(disk, &t10_pi_type3_ip);
 		else
-			blk_integrity_register(disk, &dif_type1_integrity_ip);
-	else
+			blk_integrity_register(disk, &t10_pi_type1_ip);
+
+		disk->integrity->flags |= BLK_INTEGRITY_IP_CHECKSUM;
+	} else
 		if (type == SD_DIF_TYPE3_PROTECTION)
-			blk_integrity_register(disk, &dif_type3_integrity_crc);
+			blk_integrity_register(disk, &t10_pi_type3_crc);
 		else
-			blk_integrity_register(disk, &dif_type1_integrity_crc);
+			blk_integrity_register(disk, &t10_pi_type1_crc);

 	sd_printk(KERN_NOTICE, sdkp,
 		  "Enabling DIX %s protection\n", disk->integrity->name);

 	/* Signal to block layer that we support sector tagging */
-	if (dif && type && sdkp->ATO) {
+	if (dif && type) {
+
+		disk->integrity->flags |= BLK_INTEGRITY_DEVICE_CAPABLE;
+
+		if (!sdkp)
+			return;
+
 		if (type == SD_DIF_TYPE3_PROTECTION)
 			disk->integrity->tag_size = sizeof(u16) + sizeof(u32);
 		else
@ -358,50 +106,49 @@ void sd_dif_config_host(struct scsi_disk *sdkp)
 *
 * Type 3 does not have a reference tag so no remapping is required.
 */
-void sd_dif_prepare(struct request *rq, sector_t hw_sector,
-		    unsigned int sector_sz)
+void sd_dif_prepare(struct scsi_cmnd *scmd)
 {
-	const int tuple_sz = sizeof(struct sd_dif_tuple);
+	const int tuple_sz = sizeof(struct t10_pi_tuple);
 	struct bio *bio;
 	struct scsi_disk *sdkp;
-	struct sd_dif_tuple *sdt;
+	struct t10_pi_tuple *pi;
 	u32 phys, virt;

-	sdkp = rq->bio->bi_bdev->bd_disk->private_data;
+	sdkp = scsi_disk(scmd->request->rq_disk);

 	if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION)
 		return;

-	phys = hw_sector & 0xffffffff;
+	phys = scsi_prot_ref_tag(scmd);

-	__rq_for_each_bio(bio, rq) {
+	__rq_for_each_bio(bio, scmd->request) {
+		struct bio_integrity_payload *bip = bio_integrity(bio);
 		struct bio_vec iv;
 		struct bvec_iter iter;
 		unsigned int j;

 		/* Already remapped? */
-		if (bio_flagged(bio, BIO_MAPPED_INTEGRITY))
+		if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
 			break;

-		virt = bio->bi_integrity->bip_iter.bi_sector & 0xffffffff;
+		virt = bip_get_seed(bip) & 0xffffffff;

-		bip_for_each_vec(iv, bio->bi_integrity, iter) {
-			sdt = kmap_atomic(iv.bv_page)
-				+ iv.bv_offset;
+		bip_for_each_vec(iv, bip, iter) {
+			pi = kmap_atomic(iv.bv_page) + iv.bv_offset;

-			for (j = 0; j < iv.bv_len; j += tuple_sz, sdt++) {
+			for (j = 0; j < iv.bv_len; j += tuple_sz, pi++) {

-				if (be32_to_cpu(sdt->ref_tag) == virt)
-					sdt->ref_tag = cpu_to_be32(phys);
+				if (be32_to_cpu(pi->ref_tag) == virt)
+					pi->ref_tag = cpu_to_be32(phys);

 				virt++;
 				phys++;
 			}

-			kunmap_atomic(sdt);
+			kunmap_atomic(pi);
 		}

-		bio->bi_flags |= (1 << BIO_MAPPED_INTEGRITY);
+		bip->bip_flags |= BIP_MAPPED_INTEGRITY;
 	}
 }

@ -411,11 +158,11 @@ void sd_dif_prepare(struct request *rq, sector_t hw_sector,
 */
 void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
 {
-	const int tuple_sz = sizeof(struct sd_dif_tuple);
+	const int tuple_sz = sizeof(struct t10_pi_tuple);
 	struct scsi_disk *sdkp;
 	struct bio *bio;
-	struct sd_dif_tuple *sdt;
-	unsigned int j, sectors, sector_sz;
+	struct t10_pi_tuple *pi;
+	unsigned int j, intervals;
 	u32 phys, virt;

 	sdkp = scsi_disk(scmd->request->rq_disk);
@ -423,39 +170,35 @@ void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
 	if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION || good_bytes == 0)
 		return;

-	sector_sz = scmd->device->sector_size;
-	sectors = good_bytes / sector_sz;
-
-	phys = blk_rq_pos(scmd->request) & 0xffffffff;
-	if (sector_sz == 4096)
-		phys >>= 3;
+	intervals = good_bytes / scsi_prot_interval(scmd);
+	phys = scsi_prot_ref_tag(scmd);

 	__rq_for_each_bio(bio, scmd->request) {
+		struct bio_integrity_payload *bip = bio_integrity(bio);
 		struct bio_vec iv;
 		struct bvec_iter iter;

-		virt = bio->bi_integrity->bip_iter.bi_sector & 0xffffffff;
+		virt = bip_get_seed(bip) & 0xffffffff;

-		bip_for_each_vec(iv, bio->bi_integrity, iter) {
-			sdt = kmap_atomic(iv.bv_page)
-				+ iv.bv_offset;
+		bip_for_each_vec(iv, bip, iter) {
+			pi = kmap_atomic(iv.bv_page) + iv.bv_offset;

-			for (j = 0; j < iv.bv_len; j += tuple_sz, sdt++) {
+			for (j = 0; j < iv.bv_len; j += tuple_sz, pi++) {

-				if (sectors == 0) {
-					kunmap_atomic(sdt);
+				if (intervals == 0) {
+					kunmap_atomic(pi);
 					return;
 				}

-				if (be32_to_cpu(sdt->ref_tag) == phys)
-					sdt->ref_tag = cpu_to_be32(virt);
+				if (be32_to_cpu(pi->ref_tag) == phys)
+					pi->ref_tag = cpu_to_be32(virt);

 				virt++;
 				phys++;
-				sectors--;
+				intervals--;
 			}

-			kunmap_atomic(sdt);
+			kunmap_atomic(pi);
 		}
 	}
 }
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@ -1711,9 +1711,9 @@ sg_start_req(Sg_request *srp, unsigned char *cmd)
 	}

 	rq = blk_get_request(q, rw, GFP_ATOMIC);
-	if (!rq) {
+	if (IS_ERR(rq)) {
 		kfree(long_cmdp);
-		return -ENOMEM;
+		return PTR_ERR(rq);
 	}

 	blk_rq_set_block_pc(rq);
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@ -490,7 +490,7 @@ static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,

 	req = blk_get_request(SRpnt->stp->device->request_queue, write,
 			      GFP_KERNEL);
-	if (!req)
+	if (IS_ERR(req))
 		return DRIVER_ERROR << 24;

 	blk_rq_set_block_pc(req);
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@ -1050,7 +1050,7 @@ pscsi_execute_cmd(struct se_cmd *cmd)
 		req = blk_get_request(pdv->pdv_sd->request_queue,
 				(data_direction == DMA_TO_DEVICE),
 				GFP_KERNEL);
-		if (!req) {
+		if (IS_ERR(req)) {
 			pr_err("PSCSI: blk_get_request() failed\n");
 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 			goto fail;
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@ -50,32 +50,22 @@ inline struct block_device *I_BDEV(struct inode *inode)
 EXPORT_SYMBOL(I_BDEV);

 /*
- * Move the inode from its current bdi to a new bdi. If the inode is dirty we
- * need to move it onto the dirty list of @dst so that the inode is always on
- * the right list.
+ * Move the inode from its current bdi to a new bdi.  Make sure the inode
+ * is clean before moving so that it doesn't linger on the old bdi.
 */
 static void bdev_inode_switch_bdi(struct inode *inode,
 			struct backing_dev_info *dst)
 {
-	struct backing_dev_info *old = inode->i_data.backing_dev_info;
-	bool wakeup_bdi = false;
-
-	if (unlikely(dst == old))		/* deadlock avoidance */
-		return;
-	bdi_lock_two(&old->wb, &dst->wb);
-	spin_lock(&inode->i_lock);
-	inode->i_data.backing_dev_info = dst;
-	if (inode->i_state & I_DIRTY) {
-		if (bdi_cap_writeback_dirty(dst) && !wb_has_dirty_io(&dst->wb))
-			wakeup_bdi = true;
-		list_move(&inode->i_wb_list, &dst->wb.b_dirty);
+	while (true) {
+		spin_lock(&inode->i_lock);
+		if (!(inode->i_state & I_DIRTY)) {
+			inode->i_data.backing_dev_info = dst;
+			spin_unlock(&inode->i_lock);
+			return;
+		}
+		spin_unlock(&inode->i_lock);
+		WARN_ON_ONCE(write_inode_now(inode, true));
 	}
-	spin_unlock(&inode->i_lock);
-	spin_unlock(&old->wb.list_lock);
-	spin_unlock(&dst->wb.list_lock);
-
-	if (wakeup_bdi)
-		bdi_wakeup_thread_delayed(dst);
 }

 /* Kill _all_ buffers and pagecache , dirty or not.. */
@ -1179,8 +1169,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 			if (!ret) {
 				bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
 				bdi = blk_get_backing_dev_info(bdev);
-				if (bdi == NULL)
-					bdi = &default_backing_dev_info;
 				bdev_inode_switch_bdi(bdev->bd_inode, bdi);
 			}

--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@ -1702,7 +1702,7 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits)
 		if (!device->bdev)
 			continue;
 		bdi = blk_get_backing_dev_info(device->bdev);
-		if (bdi && bdi_congested(bdi, bdi_bits)) {
+		if (bdi_congested(bdi, bdi_bits)) {
 			ret = 1;
 			break;
 		}
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@ -220,11 +220,9 @@ ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter, loff_t
 #else
 	VM_BUG_ON(iocb->ki_nbytes != PAGE_SIZE);

-	if (rw == READ || rw == KERNEL_READ)
-		return nfs_file_direct_read(iocb, iter, pos,
-				rw == READ ? true : false);
-	return nfs_file_direct_write(iocb, iter, pos,
-				rw == WRITE ? true : false);
+	if (rw == READ)
+		return nfs_file_direct_read(iocb, iter, pos);
+	return nfs_file_direct_write(iocb, iter, pos);
 #endif /* CONFIG_NFS_SWAP */
 }

@ -510,7 +508,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
 * cache.
 */
 ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
-				loff_t pos, bool uio)
+				loff_t pos)
 {
 	struct file *file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
@ -879,7 +877,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
 * is no atomic O_APPEND write facility in the NFS protocol.
 */
 ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
-				loff_t pos, bool uio)
+				loff_t pos)
 {
 	ssize_t result = -EINVAL;
 	struct file *file = iocb->ki_filp;
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@ -172,7 +172,7 @@ nfs_file_read(struct kiocb *iocb, struct iov_iter *to)
 	ssize_t result;

 	if (iocb->ki_filp->f_flags & O_DIRECT)
-		return nfs_file_direct_read(iocb, to, iocb->ki_pos, true);
+		return nfs_file_direct_read(iocb, to, iocb->ki_pos);

 	dprintk("NFS: read(%pD2, %zu@%lu)\n",
 		iocb->ki_filp,
@ -676,7 +676,7 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from)
 		return result;

 	if (file->f_flags & O_DIRECT)
-		return nfs_file_direct_write(iocb, from, pos, true);
+		return nfs_file_direct_write(iocb, from, pos);

 	dprintk("NFS: write(%pD2, %zu@%Ld)\n",
 		file, count, (long long) pos);
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@ -1670,8 +1670,6 @@ xfs_alloc_buftarg(
 	btp->bt_dev =  bdev->bd_dev;
 	btp->bt_bdev = bdev;
 	btp->bt_bdi = blk_get_backing_dev_info(bdev);
-	if (!btp->bt_bdi)
-		goto error;

 	if (xfs_setsize_buftarg_early(btp, bdev))
 		goto error;
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@ -28,12 +28,10 @@ struct dentry;
 * Bits in backing_dev_info.state
 */
 enum bdi_state {
-	BDI_wb_alloc,		/* Default embedded wb allocated */
 	BDI_async_congested,	/* The async (write) queue is getting full */
 	BDI_sync_congested,	/* The sync queue is getting full */
 	BDI_registered,		/* bdi_register() was done */
 	BDI_writeback_running,	/* Writeback is in progress */
-	BDI_unused,		/* Available bits start here */
 };

 typedef int (congested_fn)(void *, int);
@ -50,7 +48,6 @@ enum bdi_stat_item {

 struct bdi_writeback {
 	struct backing_dev_info *bdi;	/* our parent bdi */
-	unsigned int nr;

 	unsigned long last_old_flush;	/* last old data flush */

@ -124,7 +121,6 @@ void bdi_start_background_writeback(struct backing_dev_info *bdi);
 void bdi_writeback_workfn(struct work_struct *work);
 int bdi_has_dirty_io(struct backing_dev_info *bdi);
 void bdi_wakeup_thread_delayed(struct backing_dev_info *bdi);
-void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2);

 extern spinlock_t bdi_lock;
 extern struct list_head bdi_list;
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@ -292,7 +292,24 @@ static inline unsigned bio_segments(struct bio *bio)
 */
 #define bio_get(bio)	atomic_inc(&(bio)->bi_cnt)

+enum bip_flags {
+	BIP_BLOCK_INTEGRITY	= 1 << 0, /* block layer owns integrity data */
+	BIP_MAPPED_INTEGRITY	= 1 << 1, /* ref tag has been remapped */
+	BIP_CTRL_NOCHECK	= 1 << 2, /* disable HBA integrity checking */
+	BIP_DISK_NOCHECK	= 1 << 3, /* disable disk integrity checking */
+	BIP_IP_CHECKSUM		= 1 << 4, /* IP checksum */
+};
+
 #if defined(CONFIG_BLK_DEV_INTEGRITY)
+
+static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
+{
+	if (bio->bi_rw & REQ_INTEGRITY)
+		return bio->bi_integrity;
+
+	return NULL;
+}
+
 /*
 * bio integrity payload
 */
@ -301,21 +318,40 @@ struct bio_integrity_payload {

 	struct bvec_iter	bip_iter;

-	/* kill - should just use bip_vec */
-	void			*bip_buf;	/* generated integrity data */
-
 	bio_end_io_t		*bip_end_io;	/* saved I/O completion fn */

 	unsigned short		bip_slab;	/* slab the bip came from */
 	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
 	unsigned short		bip_max_vcnt;	/* integrity bio_vec slots */
-	unsigned		bip_owns_buf:1;	/* should free bip_buf */
+	unsigned short		bip_flags;	/* control flags */

 	struct work_struct	bip_work;	/* I/O completion */

 	struct bio_vec		*bip_vec;
 	struct bio_vec		bip_inline_vecs[0];/* embedded bvec array */
 };
+
+static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
+{
+	struct bio_integrity_payload *bip = bio_integrity(bio);
+
+	if (bip)
+		return bip->bip_flags & flag;
+
+	return false;
+}
+
+static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
+{
+	return bip->bip_iter.bi_sector;
+}
+
+static inline void bip_set_seed(struct bio_integrity_payload *bip,
+				sector_t seed)
+{
+	bip->bip_iter.bi_sector = seed;
+}
+
 #endif /* CONFIG_BLK_DEV_INTEGRITY */

 extern void bio_trim(struct bio *bio, int offset, int size);
@ -342,6 +378,7 @@ static inline struct bio *bio_next_split(struct bio *bio, int sectors,
 }

 extern struct bio_set *bioset_create(unsigned int, unsigned int);
+extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
 extern void bioset_free(struct bio_set *);
 extern mempool_t *biovec_create_pool(int pool_entries);

@ -353,7 +390,6 @@ extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
 extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);

 extern struct bio_set *fs_bio_set;
-unsigned int bio_integrity_tag_size(struct bio *bio);

 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
 {
@ -661,14 +697,10 @@ struct biovec_slab {
 	for_each_bio(_bio)						\
 		bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)

-#define bio_integrity(bio) (bio->bi_integrity != NULL)
-
 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
 extern void bio_integrity_free(struct bio *);
 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
-extern int bio_integrity_enabled(struct bio *bio);
-extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
-extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
+extern bool bio_integrity_enabled(struct bio *bio);
 extern int bio_integrity_prep(struct bio *);
 extern void bio_integrity_endio(struct bio *, int);
 extern void bio_integrity_advance(struct bio *, unsigned int);
@ -680,14 +712,14 @@ extern void bio_integrity_init(void);

 #else /* CONFIG_BLK_DEV_INTEGRITY */

-static inline int bio_integrity(struct bio *bio)
+static inline void *bio_integrity(struct bio *bio)
 {
-	return 0;
+	return NULL;
 }

-static inline int bio_integrity_enabled(struct bio *bio)
+static inline bool bio_integrity_enabled(struct bio *bio)
 {
-	return 0;
+	return false;
 }

 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
@ -733,6 +765,11 @@ static inline void bio_integrity_init(void)
 	return;
 }

+static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
+{
+	return false;
+}
+
 #endif /* CONFIG_BLK_DEV_INTEGRITY */

 #endif /* CONFIG_BLOCK */
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@ -4,6 +4,7 @@
 #include <linux/blkdev.h>

 struct blk_mq_tags;
+struct blk_flush_queue;

 struct blk_mq_cpu_notifier {
 	struct list_head list;
@ -34,6 +35,7 @@ struct blk_mq_hw_ctx {

 	struct request_queue	*queue;
 	unsigned int		queue_num;
+	struct blk_flush_queue	*fq;

 	void			*driver_data;

@ -77,8 +79,9 @@ struct blk_mq_tag_set {
 	struct list_head	tag_list;
 };

-typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *);
+typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *, bool);
 typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
+typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool);
 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
 typedef int (init_request_fn)(void *, struct request *, unsigned int,
@ -86,6 +89,9 @@ typedef int (init_request_fn)(void *, struct request *, unsigned int,
 typedef void (exit_request_fn)(void *, struct request *, unsigned int,
 		unsigned int);

+typedef void (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
+		bool);
+
 struct blk_mq_ops {
 	/*
 	 * Queue request
@ -100,7 +106,7 @@ struct blk_mq_ops {
 	/*
 	 * Called on request timeout
 	 */
-	rq_timed_out_fn		*timeout;
+	timeout_fn		*timeout;

 	softirq_done_fn		*complete;

@ -115,6 +121,10 @@ struct blk_mq_ops {
 	/*
 	 * Called for every command allocated by the block layer to allow
 	 * the driver to set up driver specific data.
+	 *
+	 * Tag greater than or equal to queue_depth is for setting up
+	 * flush request.
+	 *
 	 * Ditto for exit/teardown.
 	 */
 	init_request_fn		*init_request;
@ -160,8 +170,9 @@ struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
 struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int, int);

-void blk_mq_end_io(struct request *rq, int error);
-void __blk_mq_end_io(struct request *rq, int error);
+void blk_mq_start_request(struct request *rq);
+void blk_mq_end_request(struct request *rq, int error);
+void __blk_mq_end_request(struct request *rq, int error);

 void blk_mq_requeue_request(struct request *rq);
 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head);
@ -174,7 +185,8 @@ void blk_mq_stop_hw_queues(struct request_queue *q);
 void blk_mq_start_hw_queues(struct request_queue *q);
 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
 void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
-void blk_mq_tag_busy_iter(struct blk_mq_tags *tags, void (*fn)(void *data, unsigned long *), void *data);
+void blk_mq_tag_busy_iter(struct blk_mq_hw_ctx *hctx, busy_iter_fn *fn,
+		void *priv);

 /*
 * Driver command data is immediately after the request. So subtract request
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@ -78,9 +78,11 @@ struct bio {
 	struct io_context	*bi_ioc;
 	struct cgroup_subsys_state *bi_css;
 #endif
+	union {
 #if defined(CONFIG_BLK_DEV_INTEGRITY)
-	struct bio_integrity_payload *bi_integrity;  /* data integrity */
+		struct bio_integrity_payload *bi_integrity; /* data integrity */
 #endif
+	};

 	unsigned short		bi_vcnt;	/* how many bio_vec's */

@ -118,10 +120,8 @@ struct bio {
 #define BIO_USER_MAPPED 6	/* contains user pages */
 #define BIO_EOPNOTSUPP	7	/* not supported */
 #define BIO_NULL_MAPPED 8	/* contains invalid user pages */
-#define BIO_FS_INTEGRITY 9	/* fs owns integrity data, not block layer */
-#define BIO_QUIET	10	/* Make BIO Quiet */
-#define BIO_MAPPED_INTEGRITY 11/* integrity metadata has been remapped */
-#define BIO_SNAP_STABLE	12	/* bio data must be snapshotted during write */
+#define BIO_QUIET	9	/* Make BIO Quiet */
+#define BIO_SNAP_STABLE	10	/* bio data must be snapshotted during write */

 /*
 * Flags starting here get preserved by bio_reset() - this includes
@ -162,6 +162,7 @@ enum rq_flag_bits {
 	__REQ_WRITE_SAME,	/* write same block many times */

 	__REQ_NOIDLE,		/* don't anticipate more IO after this one */
+	__REQ_INTEGRITY,	/* I/O includes block integrity payload */
 	__REQ_FUA,		/* forced unit access */
 	__REQ_FLUSH,		/* request for cache flush */

@ -186,9 +187,7 @@ enum rq_flag_bits {
 	__REQ_FLUSH_SEQ,	/* request for flush sequence */
 	__REQ_IO_STAT,		/* account I/O stat */
 	__REQ_MIXED_MERGE,	/* merge of different types, fail separately */
-	__REQ_KERNEL, 		/* direct IO to kernel pages */
 	__REQ_PM,		/* runtime pm request */
-	__REQ_END,		/* last of chain of requests */
 	__REQ_HASHED,		/* on IO scheduler merge hash */
 	__REQ_MQ_INFLIGHT,	/* track inflight for MQ */
 	__REQ_NR_BITS,		/* stops here */
@ -204,13 +203,14 @@ enum rq_flag_bits {
 #define REQ_DISCARD		(1ULL << __REQ_DISCARD)
 #define REQ_WRITE_SAME		(1ULL << __REQ_WRITE_SAME)
 #define REQ_NOIDLE		(1ULL << __REQ_NOIDLE)
+#define REQ_INTEGRITY		(1ULL << __REQ_INTEGRITY)

 #define REQ_FAILFAST_MASK \
 	(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
 #define REQ_COMMON_MASK \
 	(REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | \
 	 REQ_DISCARD | REQ_WRITE_SAME | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | \
-	 REQ_SECURE)
+	 REQ_SECURE | REQ_INTEGRITY)
 #define REQ_CLONE_MASK		REQ_COMMON_MASK

 #define BIO_NO_ADVANCE_ITER_MASK	(REQ_DISCARD|REQ_WRITE_SAME)
@ -240,9 +240,7 @@ enum rq_flag_bits {
 #define REQ_IO_STAT		(1ULL << __REQ_IO_STAT)
 #define REQ_MIXED_MERGE		(1ULL << __REQ_MIXED_MERGE)
 #define REQ_SECURE		(1ULL << __REQ_SECURE)
-#define REQ_KERNEL		(1ULL << __REQ_KERNEL)
 #define REQ_PM			(1ULL << __REQ_PM)
-#define REQ_END			(1ULL << __REQ_END)
 #define REQ_HASHED		(1ULL << __REQ_HASHED)
 #define REQ_MQ_INFLIGHT		(1ULL << __REQ_MQ_INFLIGHT)

--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@ -36,6 +36,7 @@ struct request;
 struct sg_io_hdr;
 struct bsg_job;
 struct blkcg_gq;
+struct blk_flush_queue;

 #define BLKDEV_MIN_RQ	4
 #define BLKDEV_MAX_RQ	128	/* Default maximum */
@ -455,14 +456,7 @@ struct request_queue {
 	 */
 	unsigned int		flush_flags;
 	unsigned int		flush_not_queueable:1;
-	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;
+	struct blk_flush_queue	*fq;

 	struct list_head	requeue_list;
 	spinlock_t		requeue_lock;
@ -865,7 +859,7 @@ extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,

 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
 {
-	return bdev->bd_disk->queue;
+	return bdev->bd_disk->queue;	/* this is never NULL */
 }

 /*
@ -1285,10 +1279,9 @@ static inline int queue_alignment_offset(struct request_queue *q)
 static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
 {
 	unsigned int granularity = max(lim->physical_block_size, lim->io_min);
-	unsigned int alignment = (sector << 9) & (granularity - 1);
+	unsigned int alignment = sector_div(sector, granularity >> 9) << 9;

-	return (granularity + lim->alignment_offset - alignment)
-		& (granularity - 1);
+	return (granularity + lim->alignment_offset - alignment) % granularity;
 }

 static inline int bdev_alignment_offset(struct block_device *bdev)
@ -1464,32 +1457,31 @@ static inline uint64_t rq_io_start_time_ns(struct request *req)

 #if defined(CONFIG_BLK_DEV_INTEGRITY)

-#define INTEGRITY_FLAG_READ	2	/* verify data integrity on read */
-#define INTEGRITY_FLAG_WRITE	4	/* generate data integrity on write */
+enum blk_integrity_flags {
+	BLK_INTEGRITY_VERIFY		= 1 << 0,
+	BLK_INTEGRITY_GENERATE		= 1 << 1,
+	BLK_INTEGRITY_DEVICE_CAPABLE	= 1 << 2,
+	BLK_INTEGRITY_IP_CHECKSUM	= 1 << 3,
+};

-struct blk_integrity_exchg {
+struct blk_integrity_iter {
 	void			*prot_buf;
 	void			*data_buf;
-	sector_t		sector;
+	sector_t		seed;
 	unsigned int		data_size;
-	unsigned short		sector_size;
+	unsigned short		interval;
 	const char		*disk_name;
 };

-typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
-typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
-typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
-typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
+typedef int (integrity_processing_fn) (struct blk_integrity_iter *);

 struct blk_integrity {
-	integrity_gen_fn	*generate_fn;
-	integrity_vrfy_fn	*verify_fn;
-	integrity_set_tag_fn	*set_tag_fn;
-	integrity_get_tag_fn	*get_tag_fn;
+	integrity_processing_fn	*generate_fn;
+	integrity_processing_fn	*verify_fn;

 	unsigned short		flags;
 	unsigned short		tuple_size;
-	unsigned short		sector_size;
+	unsigned short		interval;
 	unsigned short		tag_size;

 	const char		*name;
@ -1504,10 +1496,10 @@ extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
 extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
 				   struct scatterlist *);
 extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
-extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
-				  struct request *);
-extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
-				   struct bio *);
+extern bool blk_integrity_merge_rq(struct request_queue *, struct request *,
+				   struct request *);
+extern bool blk_integrity_merge_bio(struct request_queue *, struct request *,
+				    struct bio *);

 static inline
 struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
@ -1520,12 +1512,9 @@ static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
 	return disk->integrity;
 }

-static inline int blk_integrity_rq(struct request *rq)
+static inline bool blk_integrity_rq(struct request *rq)
 {
-	if (rq->bio == NULL)
-		return 0;
-
-	return bio_integrity(rq->bio);
+	return rq->cmd_flags & REQ_INTEGRITY;
 }

 static inline void blk_queue_max_integrity_segments(struct request_queue *q,
@ -1590,15 +1579,15 @@ static inline unsigned short queue_max_integrity_segments(struct request_queue *
 {
 	return 0;
 }
-static inline int blk_integrity_merge_rq(struct request_queue *rq,
-					 struct request *r1,
-					 struct request *r2)
+static inline bool blk_integrity_merge_rq(struct request_queue *rq,
+					  struct request *r1,
+					  struct request *r2)
 {
 	return 0;
 }
-static inline int blk_integrity_merge_bio(struct request_queue *rq,
-					  struct request *r,
-					  struct bio *b)
+static inline bool blk_integrity_merge_bio(struct request_queue *rq,
+					   struct request *r,
+					   struct bio *b)
 {
 	return 0;
 }
--- a/include/linux/crc-t10dif.h
+++ b/include/linux/crc-t10dif.h
@ -6,7 +6,8 @@
 #define CRC_T10DIF_DIGEST_SIZE 2
 #define CRC_T10DIF_BLOCK_SIZE 1

-__u16 crc_t10dif_generic(__u16 crc, const unsigned char *buffer, size_t len);
-__u16 crc_t10dif(unsigned char const *, size_t);
+extern __u16 crc_t10dif_generic(__u16 crc, const unsigned char *buffer,
+				size_t len);
+extern __u16 crc_t10dif(unsigned char const *, size_t);

 #endif
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@ -192,8 +192,6 @@ typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
 #define READ			0
 #define WRITE			RW_MASK
 #define READA			RWA_MASK
-#define KERNEL_READ		(READ|REQ_KERNEL)
-#define KERNEL_WRITE		(WRITE|REQ_KERNEL)

 #define READ_SYNC		(READ | REQ_SYNC)
 #define WRITE_SYNC		(WRITE | REQ_SYNC | REQ_NOIDLE)
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@ -448,10 +448,10 @@ static inline struct rpc_cred *nfs_file_cred(struct file *file)
 extern ssize_t nfs_direct_IO(int, struct kiocb *, struct iov_iter *, loff_t);
 extern ssize_t nfs_file_direct_read(struct kiocb *iocb,
 			struct iov_iter *iter,
-			loff_t pos, bool uio);
+			loff_t pos);
 extern ssize_t nfs_file_direct_write(struct kiocb *iocb,
 			struct iov_iter *iter,
-			loff_t pos, bool uio);
+			loff_t pos);

 /*
 * linux/fs/nfs/dir.c
--- a/include/linux/t10-pi.h
+++ b/include/linux/t10-pi.h
@ -0,0 +1,22 @@
+#ifndef _LINUX_T10_PI_H
+#define _LINUX_T10_PI_H
+
+#include <linux/types.h>
+#include <linux/blkdev.h>
+
+/*
+ * T10 Protection Information tuple.
+ */
+struct t10_pi_tuple {
+	__be16 guard_tag;	/* Checksum */
+	__be16 app_tag;		/* Opaque storage */
+	__be32 ref_tag;		/* Target LBA or indirect LBA */
+};
+
+
+extern struct blk_integrity t10_pi_type1_crc;
+extern struct blk_integrity t10_pi_type1_ip;
+extern struct blk_integrity t10_pi_type3_crc;
+extern struct blk_integrity t10_pi_type3_ip;
+
+#endif
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@ -10,9 +10,10 @@
 #include <scsi/scsi_device.h>

 struct Scsi_Host;
-struct scsi_device;
 struct scsi_driver;

+#include <scsi/scsi_device.h>
+
 /*
 * MAX_COMMAND_SIZE is:
 * The longest fixed-length SCSI CDB as per the SCSI standard.
@ -81,6 +82,7 @@ struct scsi_cmnd {

 	unsigned char prot_op;
 	unsigned char prot_type;
+	unsigned char prot_flags;

 	unsigned short cmd_len;
 	enum dma_data_direction sc_data_direction;
@ -252,6 +254,14 @@ static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
 	return scmd->prot_op;
 }

+enum scsi_prot_flags {
+	SCSI_PROT_TRANSFER_PI		= 1 << 0,
+	SCSI_PROT_GUARD_CHECK		= 1 << 1,
+	SCSI_PROT_REF_CHECK		= 1 << 2,
+	SCSI_PROT_REF_INCREMENT		= 1 << 3,
+	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
+};
+
 /*
 * The controller usually does not know anything about the target it
 * is communicating with.  However, when DIX is enabled the controller
@ -280,6 +290,17 @@ static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 	return blk_rq_pos(scmd->request);
 }

+static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
+{
+	return scmd->device->sector_size;
+}
+
+static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
+{
+	return blk_rq_pos(scmd->request) >>
+		(ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
+}
+
 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 {
 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
@ -316,17 +337,12 @@ static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 {
 	unsigned int xfer_len = scsi_out(scmd)->length;
-	unsigned int prot_op = scsi_get_prot_op(scmd);
-	unsigned int sector_size = scmd->device->sector_size;
+	unsigned int prot_interval = scsi_prot_interval(scmd);

-	switch (prot_op) {
-	case SCSI_PROT_NORMAL:
-	case SCSI_PROT_WRITE_STRIP:
-	case SCSI_PROT_READ_INSERT:
-		return xfer_len;
-	}
+	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
+		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;

-	return xfer_len + (xfer_len >> ilog2(sector_size)) * 8;
+	return xfer_len;
 }

 #endif /* _SCSI_SCSI_CMND_H */
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@ -40,7 +40,7 @@ LIST_HEAD(bdi_list);
 /* bdi_wq serves all asynchronous writeback tasks */
 struct workqueue_struct *bdi_wq;

-void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2)
+static void bdi_lock_two(struct bdi_writeback *wb1, struct bdi_writeback *wb2)
 {
 	if (wb1 < wb2) {
 		spin_lock(&wb1->list_lock);
@ -376,13 +376,7 @@ static void bdi_wb_shutdown(struct backing_dev_info *bdi)
 	mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0);
 	flush_delayed_work(&bdi->wb.dwork);
 	WARN_ON(!list_empty(&bdi->work_list));
-
-	/*
-	 * This shouldn't be necessary unless @bdi for some reason has
-	 * unflushed dirty IO after work_list is drained.  Do it anyway
-	 * just in case.
-	 */
-	cancel_delayed_work_sync(&bdi->wb.dwork);
+	WARN_ON(delayed_work_pending(&bdi->wb.dwork));
 }

 /*
@ -402,21 +396,15 @@ static void bdi_prune_sb(struct backing_dev_info *bdi)

 void bdi_unregister(struct backing_dev_info *bdi)
 {
-	struct device *dev = bdi->dev;
-
-	if (dev) {
+	if (bdi->dev) {
 		bdi_set_min_ratio(bdi, 0);
 		trace_writeback_bdi_unregister(bdi);
 		bdi_prune_sb(bdi);

 		bdi_wb_shutdown(bdi);
 		bdi_debug_unregister(bdi);
-
-		spin_lock_bh(&bdi->wb_lock);
+		device_unregister(bdi->dev);
 		bdi->dev = NULL;
-		spin_unlock_bh(&bdi->wb_lock);
-
-		device_unregister(dev);
 	}
 }
 EXPORT_SYMBOL(bdi_unregister);
@ -487,8 +475,17 @@ void bdi_destroy(struct backing_dev_info *bdi)
 	int i;

 	/*
-	 * Splice our entries to the default_backing_dev_info, if this
-	 * bdi disappears
+	 * Splice our entries to the default_backing_dev_info.  This
+	 * condition shouldn't happen.  @wb must be empty at this point and
+	 * dirty inodes on it might cause other issues.  This workaround is
+	 * added by ce5f8e779519 ("writeback: splice dirty inode entries to
+	 * default bdi on bdi_destroy()") without root-causing the issue.
+	 *
+	 * http://lkml.kernel.org/g/1253038617-30204-11-git-send-email-jens.axboe@oracle.com
+	 * http://thread.gmane.org/gmane.linux.file-systems/35341/focus=35350
+	 *
+	 * We should probably add WARN_ON() to find out whether it still
+	 * happens and track it down if so.
 	 */
 	if (bdi_has_dirty_io(bdi)) {
 		struct bdi_writeback *dst = &default_backing_dev_info.wb;
@ -503,12 +500,7 @@ void bdi_destroy(struct backing_dev_info *bdi)

 	bdi_unregister(bdi);

-	/*
-	 * If bdi_unregister() had already been called earlier, the dwork
-	 * could still be pending because bdi_prune_sb() can race with the
-	 * bdi_wakeup_thread_delayed() calls from __mark_inode_dirty().
-	 */
-	cancel_delayed_work_sync(&bdi->wb.dwork);
+	WARN_ON(delayed_work_pending(&bdi->wb.dwork));

 	for (i = 0; i < NR_BDI_STAT_ITEMS; i++)
 		percpu_counter_destroy(&bdi->bdi_stat[i]);