Merge tag 'block-5.15-2021-09-11' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph:
     - fix nvmet command set reporting for passthrough controllers (Adam Manzanares)
     - update a MAINTAINERS email address (Chaitanya Kulkarni)
     - set QUEUE_FLAG_NOWAIT for nvme-multipth (me)
     - handle errors from add_disk() (Luis Chamberlain)
     - update the keep alive interval when kato is modified (Tatsuya Sasaki)
     - fix a buffer overrun in nvmet_subsys_attr_serial (Hannes Reinecke)
     - do not reset transport on data digest errors in nvme-tcp (Daniel Wagner)
     - only call synchronize_srcu when clearing current path (Daniel Wagner)
     - revalidate paths during rescan (Hannes Reinecke)

 - Split out the fs/block_dev into block/fops.c and block/bdev.c, which
   has been long overdue. Do this now before -rc1, to avoid annoying
   conflicts due to this (Christoph)

 - blk-throtl use-after-free fix (Li)

 - Improve plug depth for multi-device plugs, greatly increasing md
   resync performance (Song)

 - blkdev_show() locking fix (Tetsuo)

 - n64cart error check fix (Yang)

* tag 'block-5.15-2021-09-11' of git://git.kernel.dk/linux-block:
  n64cart: fix return value check in n64cart_probe()
  blk-mq: allow 4x BLK_MAX_REQUEST_COUNT at blk_plug for multiple_queues
  block: move fs/block_dev.c to block/bdev.c
  block: split out operations on block special files
  blk-throttle: fix UAF by deleteing timer in blk_throtl_exit()
  block: genhd: don't call blkdev_show() with major_names_lock held
  nvme: update MAINTAINERS email address
  nvme: add error handling support for add_disk()
  nvme: only call synchronize_srcu when clearing current path
  nvme: update keep alive interval when kato is modified
  nvme-tcp: Do not reset transport on data digest errors
  nvmet: fixup buffer overrun in nvmet_subsys_attr_serial()
  nvmet: return bool from nvmet_passthru_ctrl and nvmet_is_passthru_req
  nvmet: looks at the passthrough controller when initializing CAP
  nvme: move nvme_multi_css into nvme.h
  nvme-multipath: revalidate paths during rescan
  nvme-multipath: set QUEUE_FLAG_NOWAIT

22 files changed, 805 insertions, 682 deletions

diff --git a/Documentation/core-api/kernel-api.rst b/Documentation/core-api/kernel-api.rst
index 2a7444e3a4c2..2e7186805148 100644
--- a/Documentation/core-api/kernel-api.rst
+++ b/Documentation/core-api/kernel-api.rst
@@ -315,6 +315,9 @@ Block Devices
 .. kernel-doc:: block/genhd.c
    :export:
 
+.. kernel-doc:: block/bdev.c
+   :export:
+
 Char devices
 ============
 
diff --git a/Documentation/filesystems/api-summary.rst b/Documentation/filesystems/api-summary.rst
index 7e5c04c98619..98db2ea5fa12 100644
--- a/Documentation/filesystems/api-summary.rst
+++ b/Documentation/filesystems/api-summary.rst
@@ -71,9 +71,6 @@ Other Functions
 .. kernel-doc:: fs/fs-writeback.c
    :export:
 
-.. kernel-doc:: fs/block_dev.c
-   :export:
-
 .. kernel-doc:: fs/anon_inodes.c
    :export:
 
diff --git a/MAINTAINERS b/MAINTAINERS
index 51be43b2495b..7d46f03e5037 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3313,7 +3313,6 @@ S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git
 F:	block/
 F:	drivers/block/
-F:	fs/block_dev.c
 F:	include/linux/blk*
 F:	kernel/trace/blktrace.c
 F:	lib/sbitmap.c
@@ -13409,7 +13408,7 @@ F:	include/linux/nvme-fc.h
 NVM EXPRESS TARGET DRIVER
 M:	Christoph Hellwig <hch@lst.de>
 M:	Sagi Grimberg <sagi@grimberg.me>
-M:	Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
+M:	Chaitanya Kulkarni <kch@nvidia.com>
 L:	linux-nvme@lists.infradead.org
 S:	Supported
 W:	http://git.infradead.org/nvme.git
diff --git a/block/Makefile b/block/Makefile
index 6cf40276d3cf..41aa1ba69c90 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -3,7 +3,7 @@
 # Makefile for the kernel block layer
 #
 
-obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-sysfs.o \
+obj-$(CONFIG_BLOCK) := bdev.o fops.o bio.o elevator.o blk-core.o blk-sysfs.o \
 			blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
 			blk-exec.o blk-merge.o blk-timeout.o \
 			blk-lib.o blk-mq.o blk-mq-tag.o blk-stat.o \
diff --git a/fs/block_dev.c b/block/bdev.c
index 45df6cbccf12..cf2780cb44a7 100644
--- a/fs/block_dev.c
+++ b/block/bdev.c
@@ -7,12 +7,10 @@
 
 #include <linux/init.h>
 #include <linux/mm.h>
-#include <linux/fcntl.h>
 #include <linux/slab.h>
 #include <linux/kmod.h>
 #include <linux/major.h>
 #include <linux/device_cgroup.h>
-#include <linux/highmem.h>
 #include <linux/blkdev.h>
 #include <linux/backing-dev.h>
 #include <linux/module.h>
@@ -20,30 +18,22 @@
 #include <linux/magic.h>
 #include <linux/buffer_head.h>
 #include <linux/swap.h>
-#include <linux/pagevec.h>
 #include <linux/writeback.h>
-#include <linux/mpage.h>
 #include <linux/mount.h>
 #include <linux/pseudo_fs.h>
 #include <linux/uio.h>
 #include <linux/namei.h>
-#include <linux/log2.h>
 #include <linux/cleancache.h>
-#include <linux/task_io_accounting_ops.h>
-#include <linux/falloc.h>
 #include <linux/part_stat.h>
 #include <linux/uaccess.h>
-#include <linux/suspend.h>
-#include "internal.h"
-#include "../block/blk.h"
+#include "../fs/internal.h"
+#include "blk.h"
 
 struct bdev_inode {
 	struct block_device bdev;
 	struct inode vfs_inode;
 };
 
-static const struct address_space_operations def_blk_aops;
-
 static inline struct bdev_inode *BDEV_I(struct inode *inode)
 {
 	return container_of(inode, struct bdev_inode, vfs_inode);
@@ -194,332 +184,6 @@ int sb_min_blocksize(struct super_block *sb, int size)
 
 EXPORT_SYMBOL(sb_min_blocksize);
 
-static int
-blkdev_get_block(struct inode *inode, sector_t iblock,
-		struct buffer_head *bh, int create)
-{
-	bh->b_bdev = I_BDEV(inode);
-	bh->b_blocknr = iblock;
-	set_buffer_mapped(bh);
-	return 0;
-}
-
-static struct inode *bdev_file_inode(struct file *file)
-{
-	return file->f_mapping->host;
-}
-
-static unsigned int dio_bio_write_op(struct kiocb *iocb)
-{
-	unsigned int op = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
-
-	/* avoid the need for a I/O completion work item */
-	if (iocb->ki_flags & IOCB_DSYNC)
-		op |= REQ_FUA;
-	return op;
-}
-
-#define DIO_INLINE_BIO_VECS 4
-
-static void blkdev_bio_end_io_simple(struct bio *bio)
-{
-	struct task_struct *waiter = bio->bi_private;
-
-	WRITE_ONCE(bio->bi_private, NULL);
-	blk_wake_io_task(waiter);
-}
-
-static ssize_t
-__blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
-		unsigned int nr_pages)
-{
-	struct file *file = iocb->ki_filp;
-	struct block_device *bdev = I_BDEV(bdev_file_inode(file));
-	struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs;
-	loff_t pos = iocb->ki_pos;
-	bool should_dirty = false;
-	struct bio bio;
-	ssize_t ret;
-	blk_qc_t qc;
-
-	if ((pos | iov_iter_alignment(iter)) &
-	    (bdev_logical_block_size(bdev) - 1))
-		return -EINVAL;
-
-	if (nr_pages <= DIO_INLINE_BIO_VECS)
-		vecs = inline_vecs;
-	else {
-		vecs = kmalloc_array(nr_pages, sizeof(struct bio_vec),
-				     GFP_KERNEL);
-		if (!vecs)
-			return -ENOMEM;
-	}
-
-	bio_init(&bio, vecs, nr_pages);
-	bio_set_dev(&bio, bdev);
-	bio.bi_iter.bi_sector = pos >> 9;
-	bio.bi_write_hint = iocb->ki_hint;
-	bio.bi_private = current;
-	bio.bi_end_io = blkdev_bio_end_io_simple;
-	bio.bi_ioprio = iocb->ki_ioprio;
-
-	ret = bio_iov_iter_get_pages(&bio, iter);
-	if (unlikely(ret))
-		goto out;
-	ret = bio.bi_iter.bi_size;
-
-	if (iov_iter_rw(iter) == READ) {
-		bio.bi_opf = REQ_OP_READ;
-		if (iter_is_iovec(iter))
-			should_dirty = true;
-	} else {
-		bio.bi_opf = dio_bio_write_op(iocb);
-		task_io_account_write(ret);
-	}
-	if (iocb->ki_flags & IOCB_NOWAIT)
-		bio.bi_opf |= REQ_NOWAIT;
-	if (iocb->ki_flags & IOCB_HIPRI)
-		bio_set_polled(&bio, iocb);
-
-	qc = submit_bio(&bio);
-	for (;;) {
-		set_current_state(TASK_UNINTERRUPTIBLE);
-		if (!READ_ONCE(bio.bi_private))
-			break;
-		if (!(iocb->ki_flags & IOCB_HIPRI) ||
-		    !blk_poll(bdev_get_queue(bdev), qc, true))
-			blk_io_schedule();
-	}
-	__set_current_state(TASK_RUNNING);
-
-	bio_release_pages(&bio, should_dirty);
-	if (unlikely(bio.bi_status))
-		ret = blk_status_to_errno(bio.bi_status);
-
-out:
-	if (vecs != inline_vecs)
-		kfree(vecs);
-
-	bio_uninit(&bio);
-
-	return ret;
-}
-
-struct blkdev_dio {
-	union {
-		struct kiocb		*iocb;
-		struct task_struct	*waiter;
-	};
-	size_t			size;
-	atomic_t		ref;
-	bool			multi_bio : 1;
-	bool			should_dirty : 1;
-	bool			is_sync : 1;
-	struct bio		bio;
-};
-
-static struct bio_set blkdev_dio_pool;
-
-static int blkdev_iopoll(struct kiocb *kiocb, bool wait)
-{
-	struct block_device *bdev = I_BDEV(kiocb->ki_filp->f_mapping->host);
-	struct request_queue *q = bdev_get_queue(bdev);
-
-	return blk_poll(q, READ_ONCE(kiocb->ki_cookie), wait);
-}
-
-static void blkdev_bio_end_io(struct bio *bio)
-{
-	struct blkdev_dio *dio = bio->bi_private;
-	bool should_dirty = dio->should_dirty;
-
-	if (bio->bi_status && !dio->bio.bi_status)
-		dio->bio.bi_status = bio->bi_status;
-
-	if (!dio->multi_bio || atomic_dec_and_test(&dio->ref)) {
-		if (!dio->is_sync) {
-			struct kiocb *iocb = dio->iocb;
-			ssize_t ret;
-
-			if (likely(!dio->bio.bi_status)) {
-				ret = dio->size;
-				iocb->ki_pos += ret;
-			} else {
-				ret = blk_status_to_errno(dio->bio.bi_status);
-			}
-
-			dio->iocb->ki_complete(iocb, ret, 0);
-			if (dio->multi_bio)
-				bio_put(&dio->bio);
-		} else {
-			struct task_struct *waiter = dio->waiter;
-
-			WRITE_ONCE(dio->waiter, NULL);
-			blk_wake_io_task(waiter);
-		}
-	}
-
-	if (should_dirty) {
-		bio_check_pages_dirty(bio);
-	} else {
-		bio_release_pages(bio, false);
-		bio_put(bio);
-	}
-}
-
-static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
-		unsigned int nr_pages)
-{
-	struct file *file = iocb->ki_filp;
-	struct inode *inode = bdev_file_inode(file);
-	struct block_device *bdev = I_BDEV(inode);
-	struct blk_plug plug;
-	struct blkdev_dio *dio;
-	struct bio *bio;
-	bool is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0;
-	bool is_read = (iov_iter_rw(iter) == READ), is_sync;
-	loff_t pos = iocb->ki_pos;
-	blk_qc_t qc = BLK_QC_T_NONE;
-	int ret = 0;
-
-	if ((pos | iov_iter_alignment(iter)) &
-	    (bdev_logical_block_size(bdev) - 1))
-		return -EINVAL;
-
-	bio = bio_alloc_kiocb(iocb, nr_pages, &blkdev_dio_pool);
-
-	dio = container_of(bio, struct blkdev_dio, bio);
-	dio->is_sync = is_sync = is_sync_kiocb(iocb);
-	if (dio->is_sync) {
-		dio->waiter = current;
-		bio_get(bio);
-	} else {
-		dio->iocb = iocb;
-	}
-
-	dio->size = 0;
-	dio->multi_bio = false;
-	dio->should_dirty = is_read && iter_is_iovec(iter);
-
-	/*
-	 * Don't plug for HIPRI/polled IO, as those should go straight
-	 * to issue
-	 */
-	if (!is_poll)
-		blk_start_plug(&plug);
-
-	for (;;) {
-		bio_set_dev(bio, bdev);
-		bio->bi_iter.bi_sector = pos >> 9;
-		bio->bi_write_hint = iocb->ki_hint;
-		bio->bi_private = dio;
-		bio->bi_end_io = blkdev_bio_end_io;
-		bio->bi_ioprio = iocb->ki_ioprio;
-
-		ret = bio_iov_iter_get_pages(bio, iter);
-		if (unlikely(ret)) {
-			bio->bi_status = BLK_STS_IOERR;
-			bio_endio(bio);
-			break;
-		}
-
-		if (is_read) {
-			bio->bi_opf = REQ_OP_READ;
-			if (dio->should_dirty)
-				bio_set_pages_dirty(bio);
-		} else {
-			bio->bi_opf = dio_bio_write_op(iocb);
-			task_io_account_write(bio->bi_iter.bi_size);
-		}
-		if (iocb->ki_flags & IOCB_NOWAIT)
-			bio->bi_opf |= REQ_NOWAIT;
-
-		dio->size += bio->bi_iter.bi_size;
-		pos += bio->bi_iter.bi_size;
-
-		nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS);
-		if (!nr_pages) {
-			bool polled = false;
-
-			if (iocb->ki_flags & IOCB_HIPRI) {
-				bio_set_polled(bio, iocb);
-				polled = true;
-			}
-
-			qc = submit_bio(bio);
-
-			if (polled)
-				WRITE_ONCE(iocb->ki_cookie, qc);
-			break;
-		}
-
-		if (!dio->multi_bio) {
-			/*
-			 * AIO needs an extra reference to ensure the dio
-			 * structure which is embedded into the first bio
-			 * stays around.
-			 */
-			if (!is_sync)
-				bio_get(bio);
-			dio->multi_bio = true;
-			atomic_set(&dio->ref, 2);
-		} else {
-			atomic_inc(&dio->ref);
-		}
-
-		submit_bio(bio);
-		bio = bio_alloc(GFP_KERNEL, nr_pages);
-	}
-
-	if (!is_poll)
-		blk_finish_plug(&plug);
-
-	if (!is_sync)
-		return -EIOCBQUEUED;
-
-	for (;;) {
-		set_current_state(TASK_UNINTERRUPTIBLE);
-		if (!READ_ONCE(dio->waiter))
-			break;
-
-		if (!(iocb->ki_flags & IOCB_HIPRI) ||
-		    !blk_poll(bdev_get_queue(bdev), qc, true))
-			blk_io_schedule();
-	}
-	__set_current_state(TASK_RUNNING);
-
-	if (!ret)
-		ret = blk_status_to_errno(dio->bio.bi_status);
-	if (likely(!ret))
-		ret = dio->size;
-
-	bio_put(&dio->bio);
-	return ret;
-}
-
-static ssize_t
-blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
-{
-	unsigned int nr_pages;
-
-	if (!iov_iter_count(iter))
-		return 0;
-
-	nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1);
-	if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_VECS)
-		return __blkdev_direct_IO_simple(iocb, iter, nr_pages);
-
-	return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages));
-}
-
-static __init int blkdev_init(void)
-{
-	return bioset_init(&blkdev_dio_pool, 4,
-				offsetof(struct blkdev_dio, bio),
-				BIOSET_NEED_BVECS|BIOSET_PERCPU_CACHE);
-}
-module_init(blkdev_init);
-
 int __sync_blockdev(struct block_device *bdev, int wait)
 {
 	if (!bdev)
@@ -637,81 +301,6 @@ out:
 }
 EXPORT_SYMBOL(thaw_bdev);
 
-static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
-{
-	return block_write_full_page(page, blkdev_get_block, wbc);
-}
-
-static int blkdev_readpage(struct file * file, struct page * page)
-{
-	return block_read_full_page(page, blkdev_get_block);
-}
-
-static void blkdev_readahead(struct readahead_control *rac)
-{
-	mpage_readahead(rac, blkdev_get_block);
-}
-
-static int blkdev_write_begin(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned flags,
-			struct page **pagep, void **fsdata)
-{
-	return block_write_begin(mapping, pos, len, flags, pagep,
-				 blkdev_get_block);
-}
-
-static int blkdev_write_end(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned copied,
-			struct page *page, void *fsdata)
-{
-	int ret;
-	ret = block_write_end(file, mapping, pos, len, copied, page, fsdata);
-
-	unlock_page(page);
-	put_page(page);
-
-	return ret;
-}
-
-/*
- * private llseek:
- * for a block special file file_inode(file)->i_size is zero
- * so we compute the size by hand (just as in block_read/write above)
- */
-static loff_t block_llseek(struct file *file, loff_t offset, int whence)
-{
-	struct inode *bd_inode = bdev_file_inode(file);
-	loff_t retval;
-
-	inode_lock(bd_inode);
-	retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode));
-	inode_unlock(bd_inode);
-	return retval;
-}
-	
-static int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
-		int datasync)
-{
-	struct inode *bd_inode = bdev_file_inode(filp);
-	struct block_device *bdev = I_BDEV(bd_inode);
-	int error;
-	
-	error = file_write_and_wait_range(filp, start, end);
-	if (error)
-		return error;
-
-	/*
-	 * There is no need to serialise calls to blkdev_issue_flush with
-	 * i_mutex and doing so causes performance issues with concurrent
-	 * O_SYNC writers to a block device.
-	 */
-	error = blkdev_issue_flush(bdev);
-	if (error == -EOPNOTSUPP)
-		error = 0;
-
-	return error;
-}
-
 /**
  * bdev_read_page() - Start reading a page from a block device
  * @bdev: The device to read the page from
@@ -1305,35 +894,6 @@ struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
 }
 EXPORT_SYMBOL(blkdev_get_by_path);
 
-static int blkdev_open(struct inode * inode, struct file * filp)
-{
-	struct block_device *bdev;
-
-	/*
-	 * Preserve backwards compatibility and allow large file access
-	 * even if userspace doesn't ask for it explicitly. Some mkfs
-	 * binary needs it. We might want to drop this workaround
-	 * during an unstable branch.
-	 */
-	filp->f_flags |= O_LARGEFILE;
-
-	filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
-
-	if (filp->f_flags & O_NDELAY)
-		filp->f_mode |= FMODE_NDELAY;
-	if (filp->f_flags & O_EXCL)
-		filp->f_mode |= FMODE_EXCL;
-	if ((filp->f_flags & O_ACCMODE) == 3)
-		filp->f_mode |= FMODE_WRITE_IOCTL;
-
-	bdev = blkdev_get_by_dev(inode->i_rdev, filp->f_mode, filp);
-	if (IS_ERR(bdev))
-		return PTR_ERR(bdev);
-	filp->f_mapping = bdev->bd_inode->i_mapping;
-	filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping);
-	return 0;
-}
-
 void blkdev_put(struct block_device *bdev, fmode_t mode)
 {
 	struct gendisk *disk = bdev->bd_disk;
@@ -1397,203 +957,6 @@ void blkdev_put(struct block_device *bdev, fmode_t mode)
 }
 EXPORT_SYMBOL(blkdev_put);
 
-static int blkdev_close(struct inode * inode, struct file * filp)
-{
-	struct block_device *bdev = I_BDEV(bdev_file_inode(filp));
-	blkdev_put(bdev, filp->f_mode);
-	return 0;
-}
-
-static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
-{
-	struct block_device *bdev = I_BDEV(bdev_file_inode(file));
-	fmode_t mode = file->f_mode;
-
-	/*
-	 * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
-	 * to updated it before every ioctl.
-	 */
-	if (file->f_flags & O_NDELAY)
-		mode |= FMODE_NDELAY;
-	else
-		mode &= ~FMODE_NDELAY;
-
-	return blkdev_ioctl(bdev, mode, cmd, arg);
-}
-
-/*
- * Write data to the block device.  Only intended for the block device itself
- * and the raw driver which basically is a fake block device.
- *
- * Does not take i_mutex for the write and thus is not for general purpose
- * use.
- */
-static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
-{
-	struct file *file = iocb->ki_filp;
-	struct inode *bd_inode = bdev_file_inode(file);
-	loff_t size = i_size_read(bd_inode);
-	struct blk_plug plug;
-	size_t shorted = 0;
-	ssize_t ret;
-
-	if (bdev_read_only(I_BDEV(bd_inode)))
-		return -EPERM;
-
-	if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev))
-		return -ETXTBSY;
-
-	if (!iov_iter_count(from))
-		return 0;
-
-	if (iocb->ki_pos >= size)
-		return -ENOSPC;
-
-	if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT)
-		return -EOPNOTSUPP;
-
-	size -= iocb->ki_pos;
-	if (iov_iter_count(from) > size) {
-		shorted = iov_iter_count(from) - size;
-		iov_iter_truncate(from, size);
-	}
-
-	blk_start_plug(&plug);
-	ret = __generic_file_write_iter(iocb, from);
-	if (ret > 0)
-		ret = generic_write_sync(iocb, ret);
-	iov_iter_reexpand(from, iov_iter_count(from) + shorted);
-	blk_finish_plug(&plug);
-	return ret;
-}
-
-static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
-{
-	struct file *file = iocb->ki_filp;
-	struct inode *bd_inode = bdev_file_inode(file);
-	loff_t size = i_size_read(bd_inode);
-	loff_t pos = iocb->ki_pos;
-	size_t shorted = 0;
-	ssize_t ret;
-
-	if (pos >= size)
-		return 0;
-
-	size -= pos;
-	if (iov_iter_count(to) > size) {
-		shorted = iov_iter_count(to) - size;
-		iov_iter_truncate(to, size);
-	}
-
-	ret = generic_file_read_iter(iocb, to);
-	iov_iter_reexpand(to, iov_iter_count(to) + shorted);
-	return ret;
-}
-
-static int blkdev_writepages(struct address_space *mapping,
-			     struct writeback_control *wbc)
-{
-	return generic_writepages(mapping, wbc);
-}
-
-static const struct address_space_operations def_blk_aops = {
-	.set_page_dirty	= __set_page_dirty_buffers,
-	.readpage	= blkdev_readpage,
-	.readahead	= blkdev_readahead,
-	.writepage	= blkdev_writepage,
-	.write_begin	= blkdev_write_begin,
-	.write_end	= blkdev_write_end,
-	.writepages	= blkdev_writepages,
-	.direct_IO	= blkdev_direct_IO,
-	.migratepage	= buffer_migrate_page_norefs,
-	.is_dirty_writeback = buffer_check_dirty_writeback,
-};
-
-#define	BLKDEV_FALLOC_FL_SUPPORTED					\
-		(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |		\
-		 FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE)
-
-static long blkdev_fallocate(struct file *file, int mode, loff_t start,
-			     loff_t len)
-{
-	struct block_device *bdev = I_BDEV(bdev_file_inode(file));
-	loff_t end = start + len - 1;
-	loff_t isize;
-	int error;
-
-	/* Fail if we don't recognize the flags. */
-	if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED)
-		return -EOPNOTSUPP;
-
-	/* Don't go off the end of the device. */
-	isize = i_size_read(bdev->bd_inode);
-	if (start >= isize)
-		return -EINVAL;
-	if (end >= isize) {
-		if (mode & FALLOC_FL_KEEP_SIZE) {
-			len = isize - start;
-			end = start + len - 1;
-		} else
-			return -EINVAL;
-	}
-
-	/*
-	 * Don't allow IO that isn't aligned to logical block size.
-	 */
-	if ((start | len) & (bdev_logical_block_size(bdev) - 1))
-		return -EINVAL;
-
-	/* Invalidate the page cache, including dirty pages. */
-	error = truncate_bdev_range(bdev, file->f_mode, start, end);
-	if (error)
-		return error;
-
-	switch (mode) {
-	case FALLOC_FL_ZERO_RANGE:
-	case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE:
-		error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
-					    GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
-		break;
-	case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
-		error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
-					     GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK);
-		break;
-	case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE:
-		error = blkdev_issue_discard(bdev, start >> 9, len >> 9,
-					     GFP_KERNEL, 0);
-		break;
-	default:
-		return -EOPNOTSUPP;
-	}
-	if (error)
-		return error;
-
-	/*
-	 * Invalidate the page cache again; if someone wandered in and dirtied
-	 * a page, we just discard it - userspace has no way of knowing whether
-	 * the write happened before or after discard completing...
-	 */
-	return truncate_bdev_range(bdev, file->f_mode, start, end);
-}
-
-const struct file_operations def_blk_fops = {
-	.open		= blkdev_open,
-	.release	= blkdev_close,
-	.llseek		= block_llseek,
-	.read_iter	= blkdev_read_iter,
-	.write_iter	= blkdev_write_iter,
-	.iopoll		= blkdev_iopoll,
-	.mmap		= generic_file_mmap,
-	.fsync		= blkdev_fsync,
-	.unlocked_ioctl	= block_ioctl,
-#ifdef CONFIG_COMPAT
-	.compat_ioctl	= compat_blkdev_ioctl,
-#endif
-	.splice_read	= generic_file_splice_read,
-	.splice_write	= iter_file_splice_write,
-	.fallocate	= blkdev_fallocate,
-};
-
 /**
  * lookup_bdev  - lookup a struct block_device by name
  * @pathname:	special file representing the block device
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 65d3a63aecc6..108a352051be 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2135,6 +2135,18 @@ static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq)
 	}
 }
 
+/*
+ * Allow 4x BLK_MAX_REQUEST_COUNT requests on plug queue for multiple
+ * queues. This is important for md arrays to benefit from merging
+ * requests.
+ */
+static inline unsigned short blk_plug_max_rq_count(struct blk_plug *plug)
+{
+	if (plug->multiple_queues)
+		return BLK_MAX_REQUEST_COUNT * 4;
+	return BLK_MAX_REQUEST_COUNT;
+}
+
 /**
  * blk_mq_submit_bio - Create and send a request to block device.
  * @bio: Bio pointer.
@@ -2231,7 +2243,7 @@ blk_qc_t blk_mq_submit_bio(struct bio *bio)
 		else
 			last = list_entry_rq(plug->mq_list.prev);
 
-		if (request_count >= BLK_MAX_REQUEST_COUNT || (last &&
+		if (request_count >= blk_plug_max_rq_count(plug) || (last &&
 		    blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) {
 			blk_flush_plug_list(plug, false);
 			trace_block_plug(q);
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 55c49015e533..7c4e7993ba97 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -2458,6 +2458,7 @@ int blk_throtl_init(struct request_queue *q)
 void blk_throtl_exit(struct request_queue *q)
 {
 	BUG_ON(!q->td);
+	del_timer_sync(&q->td->service_queue.pending_timer);
 	throtl_shutdown_wq(q);
 	blkcg_deactivate_policy(q, &blkcg_policy_throtl);
 	free_percpu(q->td->latency_buckets[READ]);
diff --git a/block/blk.h b/block/blk.h
index 8c96b0c90c48..7d2a0ba7ed21 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -373,4 +373,6 @@ static inline void bio_clear_hipri(struct bio *bio)
 	bio->bi_opf &= ~REQ_HIPRI;
 }
 
+extern const struct address_space_operations def_blk_aops;
+
 #endif /* BLK_INTERNAL_H */
diff --git a/block/fops.c b/block/fops.c
new file mode 100644
index 000000000000..ffce6f6c68dd
--- /dev/null
+++ b/block/fops.c
@@ -0,0 +1,640 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 1991, 1992  Linus Torvalds
+ * Copyright (C) 2001  Andrea Arcangeli <andrea@suse.de> SuSE
+ * Copyright (C) 2016 - 2020 Christoph Hellwig
+ */
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/blkdev.h>
+#include <linux/buffer_head.h>
+#include <linux/mpage.h>
+#include <linux/uio.h>
+#include <linux/namei.h>
+#include <linux/task_io_accounting_ops.h>
+#include <linux/falloc.h>
+#include <linux/suspend.h>
+#include "blk.h"
+
+static struct inode *bdev_file_inode(struct file *file)
+{
+	return file->f_mapping->host;
+}
+
+static int blkdev_get_block(struct inode *inode, sector_t iblock,
+		struct buffer_head *bh, int create)
+{
+	bh->b_bdev = I_BDEV(inode);
+	bh->b_blocknr = iblock;
+	set_buffer_mapped(bh);
+	return 0;
+}
+
+static unsigned int dio_bio_write_op(struct kiocb *iocb)
+{
+	unsigned int op = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
+
+	/* avoid the need for a I/O completion work item */
+	if (iocb->ki_flags & IOCB_DSYNC)
+		op |= REQ_FUA;
+	return op;
+}
+
+#define DIO_INLINE_BIO_VECS 4
+
+static void blkdev_bio_end_io_simple(struct bio *bio)
+{
+	struct task_struct *waiter = bio->bi_private;
+
+	WRITE_ONCE(bio->bi_private, NULL);
+	blk_wake_io_task(waiter);
+}
+
+static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
+		struct iov_iter *iter, unsigned int nr_pages)
+{
+	struct file *file = iocb->ki_filp;
+	struct block_device *bdev = I_BDEV(bdev_file_inode(file));
+	struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs;
+	loff_t pos = iocb->ki_pos;
+	bool should_dirty = false;
+	struct bio bio;
+	ssize_t ret;
+	blk_qc_t qc;
+
+	if ((pos | iov_iter_alignment(iter)) &
+	    (bdev_logical_block_size(bdev) - 1))
+		return -EINVAL;
+
+	if (nr_pages <= DIO_INLINE_BIO_VECS)
+		vecs = inline_vecs;
+	else {
+		vecs = kmalloc_array(nr_pages, sizeof(struct bio_vec),
+				     GFP_KERNEL);
+		if (!vecs)
+			return -ENOMEM;
+	}
+
+	bio_init(&bio, vecs, nr_pages);
+	bio_set_dev(&bio, bdev);
+	bio.bi_iter.bi_sector = pos >> 9;
+	bio.bi_write_hint = iocb->ki_hint;
+	bio.bi_private = current;
+	bio.bi_end_io = blkdev_bio_end_io_simple;
+	bio.bi_ioprio = iocb->ki_ioprio;
+
+	ret = bio_iov_iter_get_pages(&bio, iter);
+	if (unlikely(ret))
+		goto out;
+	ret = bio.bi_iter.bi_size;
+
+	if (iov_iter_rw(iter) == READ) {
+		bio.bi_opf = REQ_OP_READ;
+		if (iter_is_iovec(iter))
+			should_dirty = true;
+	} else {
+		bio.bi_opf = dio_bio_write_op(iocb);
+		task_io_account_write(ret);
+	}
+	if (iocb->ki_flags & IOCB_NOWAIT)
+		bio.bi_opf |= REQ_NOWAIT;
+	if (iocb->ki_flags & IOCB_HIPRI)