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

3 files changed, 2 insertions, 1697 deletions

diff --git a/fs/Makefile b/fs/Makefile
index 2f21300851ae..9e712aa5e254 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -17,7 +17,7 @@ obj-y :=	open.o read_write.o file_table.o super.o \
 		kernel_read_file.o remap_range.o
 
 ifeq ($(CONFIG_BLOCK),y)
-obj-y +=	buffer.o block_dev.o direct-io.o mpage.o
+obj-y +=	buffer.o direct-io.o mpage.o
 else
 obj-y +=	no-block.o
 endif
diff --git a/fs/block_dev.c b/fs/block_dev.c
deleted file mode 100644
index 45df6cbccf12..000000000000
--- a/fs/block_dev.c
+++ /dev/null
@@ -1,1695 +0,0 @@
-// 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/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>
-#include <linux/blkpg.h>
-#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"
-
-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);
-}
-
-struct block_device *I_BDEV(struct inode *inode)
-{
-	return &BDEV_I(inode)->bdev;
-}
-EXPORT_SYMBOL(I_BDEV);
-
-static void bdev_write_inode(struct block_device *bdev)
-{
-	struct inode *inode = bdev->bd_inode;
-	int ret;
-
-	spin_lock(&inode->i_lock);
-	while (inode->i_state & I_DIRTY) {
-		spin_unlock(&inode->i_lock);
-		ret = write_inode_now(inode, true);
-		if (ret) {
-			char name[BDEVNAME_SIZE];
-			pr_warn_ratelimited("VFS: Dirty inode writeback failed "
-					    "for block device %s (err=%d).\n",
-					    bdevname(bdev, name), ret);
-		}
-		spin_lock(&inode->i_lock);
-	}
-	spin_unlock(&inode->i_lock);
-}
-
-/* Kill _all_ buffers and pagecache , dirty or not.. */
-static void kill_bdev(struct block_device *bdev)
-{
-	struct address_space *mapping = bdev->bd_inode->i_mapping;
-
-	if (mapping_empty(mapping))
-		return;
-
-	invalidate_bh_lrus();
-	truncate_inode_pages(mapping, 0);
-}
-
-/* Invalidate clean unused buffers and pagecache. */
-void invalidate_bdev(struct block_device *bdev)
-{
-	struct address_space *mapping = bdev->bd_inode->i_mapping;
-
-	if (mapping->nrpages) {
-		invalidate_bh_lrus();
-		lru_add_drain_all();	/* make sure all lru add caches are flushed */
-		invalidate_mapping_pages(mapping, 0, -1);
-	}
-	/* 99% of the time, we don't need to flush the cleancache on the bdev.
-	 * But, for the strange corners, lets be cautious
-	 */
-	cleancache_invalidate_inode(mapping);
-}
-EXPORT_SYMBOL(invalidate_bdev);
-
-/*
- * Drop all buffers & page cache for given bdev range. This function bails
- * with error if bdev has other exclusive owner (such as filesystem).
- */
-int truncate_bdev_range(struct block_device *bdev, fmode_t mode,
-			loff_t lstart, loff_t lend)
-{
-	/*
-	 * If we don't hold exclusive handle for the device, upgrade to it
-	 * while we discard the buffer cache to avoid discarding buffers
-	 * under live filesystem.
-	 */
-	if (!(mode & FMODE_EXCL)) {
-		int err = bd_prepare_to_claim(bdev, truncate_bdev_range);
-		if (err)
-			goto invalidate;
-	}
-
-	truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend);
-	if (!(mode & FMODE_EXCL))
-		bd_abort_claiming(bdev, truncate_bdev_range);
-	return 0;
-
-invalidate:
-	/*
-	 * Someone else has handle exclusively open. Try invalidating instead.
-	 * The 'end' argument is inclusive so the rounding is safe.
-	 */
-	return invalidate_inode_pages2_range(bdev->bd_inode->i_mapping,
-					     lstart >> PAGE_SHIFT,
-					     lend >> PAGE_SHIFT);
-}
-
-static void set_init_blocksize(struct block_device *bdev)
-{
-	unsigned int bsize = bdev_logical_block_size(bdev);
-	loff_t size = i_size_read(bdev->bd_inode);
-
-	while (bsize < PAGE_SIZE) {
-		if (size & bsize)
-			break;
-		bsize <<= 1;
-	}
-	bdev->bd_inode->i_blkbits = blksize_bits(bsize);
-}
-
-int set_blocksize(struct block_device *bdev, int size)
-{
-	/* Size must be a power of two, and between 512 and PAGE_SIZE */
-	if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size))
-		return -EINVAL;
-
-	/* Size cannot be smaller than the size supported by the device */
-	if (size < bdev_logical_block_size(bdev))
-		return -EINVAL;
-
-	/* Don't change the size if it is same as current */
-	if (bdev->bd_inode->i_blkbits != blksize_bits(size)) {
-		sync_blockdev(bdev);
-		bdev->bd_inode->i_blkbits = blksize_bits(size);
-		kill_bdev(bdev);
-	}
-	return 0;
-}
-
-EXPORT_SYMBOL(set_blocksize);
-
-int sb_set_blocksize(struct super_block *sb, int size)
-{
-	if (set_blocksize(sb->s_bdev, size))
-		return 0;
-	/* If we get here, we know size is power of two
-	 * and it's value is between 512 and PAGE_SIZE */
-	sb->s_blocksize = size;
-	sb->s_blocksize_bits = blksize_bits(size);
-	return sb->s_blocksize;
-}
-
-EXPORT_SYMBOL(sb_set_blocksize);
-
-int sb_min_blocksize(struct super_block *sb, int size)
-{
-	int minsize = bdev_logical_block_size(sb->s_bdev);
-	if (size < minsize)
-		size = minsize;
-	return sb_set_blocksize(sb, 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)
-		return 0;
-	if (!wait)
-		return filemap_flush(bdev->bd_inode->i_mapping);
-	return filemap_write_and_wait(bdev->bd_inode->i_mapping);
-}
-
-/*
- * Write out and wait upon all the dirty data associated with a block
- * device via its mapping.  Does not take the superblock lock.
- */
-int sync_blockdev(struct block_device *bdev)
-{
-	return __sync_blockdev(bdev, 1);
-}
-EXPORT_SYMBOL(sync_blockdev);
-
-/*
- * Write out and wait upon all dirty data associated with this
- * device.   Filesystem data as well as the underlying block
- * device.  Takes the superblock lock.
- */
-int fsync_bdev(struct block_device *bdev)
-{
-	struct super_block *sb = get_super(bdev);
-	if (sb) {
-		int res = sync_filesystem(sb);
-		drop_super(sb);
-		return res;
-	}
-	return sync_blockdev(bdev);
-}
-EXPORT_SYMBOL(fsync_bdev);
-
-/**
- * freeze_bdev  --  lock a filesystem and force it into a consistent state
- * @bdev:	blockdevice to lock
- *
- * If a superblock is found on this device, we take the s_umount semaphore
- * on it to make sure nobody unmounts until the snapshot creation is done.
- * The reference counter (bd_fsfreeze_count) guarantees that only the last
- * unfreeze process can unfreeze the frozen filesystem actually when multiple
- * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
- * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
- * actually.
- */
-int freeze_bdev(struct block_device *bdev)
-{
-	struct super_block *sb;
-	int error = 0;
-
-	mutex_lock(&bdev->bd_fsfreeze_mutex);
-	if (++bdev->bd_fsfreeze_count > 1)
-		goto done;
-
-	sb = get_active_super(bdev);
-	if (!sb)
-		goto sync;
-	if (sb->s_op->freeze_super)
-		error = sb->s_op->freeze_super(sb);
-	else
-		error = freeze_super(sb);
-	deactivate_super(sb);
-
-	if (error) {
-		bdev->bd_fsfreeze_count--;
-		goto done;
-	}
-	bdev->bd_fsfreeze_sb = sb;
-
-sync:
-	sync_blockdev(bdev);
-done:
-	mutex_unlock(&bdev->bd_fsfreeze_mutex);
-	return error;
-}
-EXPORT_SYMBOL(freeze_bdev);
-
-/**
- * thaw_bdev  -- unlock filesystem
- * @bdev:	blockdevice to unlock
- *
- * Unlocks the filesystem and marks it writeable again after freeze_bdev().
- */
-int thaw_bdev(struct block_device *bdev)
-{
-	struct super_block *sb;
-	int error = -EINVAL;
-
-	mutex_lock(&bdev->bd_fsfreeze_mutex);
-	if (!bdev->bd_fsfreeze_count)
-		goto out;
-
-	error = 0;
-	if (--bdev->bd_fsfreeze_count > 0)
-		goto out;
-
-	sb = bdev->bd_fsfreeze_sb;
-	if (!sb)
-		goto out;
-
-	if (sb->s_op->thaw_super)
-		error = sb->s_op->thaw_super(sb);
-	else
-		error = thaw_super(sb);
-	if (error)
-		bdev->bd_fsfreeze_count++;
-	else
-		bdev->bd_fsfreeze_sb = NULL;
-out:
-	mutex_unlock(&bdev->bd_fsfreeze_mutex);
-	return error;
-}
-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
- * @sector: The offset on the device to read the page to (need not be aligned)
- * @page: The page to read
- *
- * On entry, the page should be locked.  It will be unlocked when the page
- * has been read.  If the block driver implements rw_page synchronously,
- * that will be true on exit from this function, but it need not be.
- *
- * Errors returned by this function are usually "soft", eg out of memory, or
- * queue full; callers should try a different route to read this page rather
- * than propagate an error back up the stack.
- *
- * Return: negative errno if an error occurs, 0 if submission was successful.
- */
-int bdev_read_page(struct block_device *bdev, sector_t sector,
-			struct page *page)
-{
-	const struct block_device_operations *ops = bdev->bd_disk->fops;
-	int result = -EOPNOTSUPP;
-
-	if (!ops->rw_page || bdev_get_integrity(bdev))
-		return result;
-
-	result = blk_queue_enter(bdev->bd_disk->queue, 0);
-	if (result)
-		return result;
-	result = ops->rw_page(bdev, sector + get_start_sect(bdev), page,
-			      REQ_OP_READ);
-	blk_queue_exit(bdev->bd_disk->queue);
-	return result;
-}
-
-/**
- * bdev_write_page() - Start writing a page to a block device
- * @bdev: The device to write the page to
- * @sector: The offset on the device to write the page to (need not be aligned)
- * @page: The page to write
- * @wbc: The writeback_control for the write
- *
- * On entry, the page should be locked and not currently under writeback.
- * On exit, if the write started successfully, the page will be unlocked and
- * under writeback.  If the write failed already (eg the driver failed to
- * queue the page to the device), the page will still be locked.  If the
- * caller is a ->writepage implementation, it will need to unlock the page.
- *
- * Errors returned by this function are usually "soft", eg out of memory, or
- * queue full; callers should try a different route to write this page rather
- * than propagate an error back up the stack.
- *
- * Return: negative errno if an error occurs, 0 if submission was successful.
- */
-int bdev_write_page(struct block_device *bdev, sector_t sector,
-			struct page *page, struct writeback_control *wbc)
-{
-	int result;
-	const struct block_device_operations *ops = bdev->bd_disk->fops;
-
-	if (!ops->rw_page || bdev_get_integrity(bdev))
-		return -EOPNOTSUPP;
-	result = blk_queue_enter(bdev->bd_disk->queue, 0);
-	if (result)
-		return result;
-
-	set_page_writeback(page);
-	result = ops->rw_page(bdev, sector + get_start_sect(bdev), page,
-			      REQ_OP_WRITE);
-	if (result) {
-		end_page_writeback(page);
-	} else {
-		clean_page_buffers(page);
-		unlock_page(page);
-	}
-	blk_queue_exit(bdev->bd_disk->queue);
-	return result;
-}
-
-/*
- * pseudo-fs
- */
-
-static  __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock);
-static struct kmem_cache * bdev_cachep __read_mostly;
-
-static struct inode *bdev_alloc_inode(struct super_block *sb)
-{
-	struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL);
-
-	if (!ei)
-		return NULL;
-	memset(&ei->bdev, 0, sizeof(ei->bdev));
-	return &ei->vfs_inode;
-}
-
-static void bdev_free_inode(struct inode *inode)
-{
-	struct block_device *bdev = I_BDEV(inode);
-
-	free_percpu(bdev->bd_stats);
-	kfree(bdev->bd_meta_info);
-
-	if (!bdev_is_partition(bdev)) {
-		if (bdev->bd_disk && bdev->bd_disk->bdi)
-			bdi_put(bdev->bd_disk->bdi);
-		kfree(bdev->bd_disk);
-	}
-
-	if (MAJOR(bdev->bd_dev) == BLOCK_EXT_MAJOR)
-		blk_free_ext_minor(MINOR(bdev->bd_dev));
-
-	kmem_cache_free(bdev_cachep, BDEV_I(inode));
-}
-
-static void init_once(void *data)
-{
-	struct bdev_inode *ei = data;
-
-	inode_init_once(&ei->vfs_inode);
-}
-
-static void bdev_evict_inode(struct inode *inode)
-{
-	truncate_inode_pages_final(&inode->i_data);
-	invalidate_inode_buffers(inode); /* is it needed here? */
-	clear_inode(inode);
-}
-
-static const struct super_operations bdev_sops = {
-	.statfs = simple_statfs,
-	.alloc_inode = bdev_alloc_inode,
-	.free_inode = bdev_free_inode,
-	.drop_inode = generic_delete_inode,
-	.evict_inode = bdev_evict_inode,
-};
-
-static int bd_init_fs_context(struct fs_context *fc)
-{
-	struct pseudo_fs_context *ctx = init_pseudo(fc, BDEVFS_MAGIC);
-	if (!ctx)
-		return -ENOMEM;
-	fc->s_iflags |= SB_I_CGROUPWB;
-	ctx->ops = &bdev_sops;
-	return 0;
-}
-
-static struct file_system_type bd_type = {
-	.name		= "bdev",
-	.init_fs_context = bd_init_fs_context,
-	.kill_sb	= kill_anon_super,
-};
-
-struct super_block *blockdev_superblock __read_mostly;
-EXPORT_SYMBOL_GPL(blockdev_superblock);
-
-void __init bdev_cache_init(void)
-{
-	int err;
-	static struct vfsmount *bd_mnt;
-
-	bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode),
-			0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
-				SLAB_MEM_SPREAD|SLAB_ACCOUNT|SLAB_PANIC),
-			init_once);
-	err = register_filesystem(&bd_type);
-	if (err)
-		panic("Cannot register bdev pseudo-fs");
-	bd_mnt = kern_mount(&bd_type);
-	if (IS_ERR(bd_mnt))
-		panic("Cannot create bdev pseudo-fs");
-	blockdev_superblock = bd_mnt->mnt_sb;   /* For writeback */
-}
-
-struct block_device *bdev_alloc(struct gendisk *disk, u8 partno)
-{
-	struct block_device *bdev;
-	struct inode *inode;
-
-	inode = new_inode(blockdev_superblock);
-	if (!inode)
-		return NULL;
-	inode->i_mode = S_IFBLK;
-	inode->i_rdev = 0;
-	inode->i_data.a_ops = &def_blk_aops;
-	mapping_set_gfp_mask(&inode->i_data, GFP_USER);
-
-	bdev = I_BDEV(inode);
-	mutex_init(&bdev->bd_fsfreeze_mutex);
-	spin_lock_init(&bdev->bd_size_lock);
-	bdev->bd_disk = disk;
-	bdev->bd_partno = partno;
-	bdev->bd_inode = inode;
-	bdev->bd_stats = alloc_percpu(struct disk_stats);
-	if (!bdev->bd_stats) {
-		iput(inode);
-		return NULL;
-	}
-	return bdev;
-}
-
-void bdev_add(struct block_device *bdev, dev_t dev)
-{
-	bdev->bd_dev = dev;
-	bdev->bd_inode->i_rdev = dev;
-	bdev->bd_inode->i_ino = dev;
-	insert_inode_hash(bdev->bd_inode);
-}
-
-long nr_blockdev_pages(void)
-{
-	struct inode *inode;
-	long ret = 0;
-
-	spin_lock(&blockdev_superblock->s_inode_list_lock);
-	list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list)
-		ret += inode->i_mapping->nrpages;
-	spin_unlock(&blockdev_superblock->s_inode_list_lock);
-
-	return ret;
-}
-
-/**
- * bd_may_claim - test whether a block device can be claimed
- * @bdev: block device of interest
- * @whole: whole block device containing @bdev, may equal @bdev
- * @holder: holder trying to claim @bdev
- *
- * Test whether @bdev can be claimed by @holder.
- *
- * CONTEXT:
- * spin_lock(&bdev_lock).
- *
- * RETURNS:
- * %true if @bdev can be claimed, %false otherwise.
- */
-static bool bd_may_claim(struct block_device *bdev, struct block_device *whole,
-			 void *holder)
-{
-	if (bdev->bd_holder == holder)
-		return true;	 /* already a holder */
-	else if (bdev->bd_holder != NULL)
-		return false; 	 /* held by someone else */
-	else if (whole == bdev)
-		return true;  	 /* is a whole device which isn't held */
-
-	else if (whole->bd_holder == bd_may_claim)
-		return true; 	 /* is a partition of a device that is being partitioned */
-	else if (whole->bd_holder != NULL)
-		return false;	 /* is a partition of a held device */
-	else
-		return true;	 /* is a partition of an un-held device */
-}
-
-/**
- * bd_prepare_to_claim - claim a block device
- * @bdev: block device of interest
- * @holder: holder trying to claim @bdev
- *
- * Claim @bdev.  This function fails if @bdev is already claimed by another
- * holder and waits if another claiming is in progress. return, the caller
- * has ownership of bd_claiming and bd_holder[s].
- *
- * RETURNS:
- * 0 if @bdev can be claimed, -EBUSY otherwise.
- */
-int bd_prepare_to_claim(struct block_device *bdev, void *holder)
-{
-	struct block_device *whole = bdev_whole(bdev);
-
-	if (WARN_ON_ONCE(!holder))
-		return -EINVAL;
-retry:
-	spin_lock(&bdev_lock);
-	/* if someone else claimed, fail */
-	if (!bd_may_claim(bdev, whole, holder)) {
-		spin_unlock(&bdev_lock);
-		return -EBUSY;
-	}
-
-	/* if claiming is already in progress, wait for it to finish */
-	if (whole->bd_claiming) {
-		wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0);
-		DEFINE_WAIT(wait);
-
-		prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);
-		spin_unlock(&bdev_lock);
-		schedule();
-		finish_wait(wq, &wait);
-		goto retry;
-	}
-
-	/* yay, all mine */
-	whole->bd_claiming = holder;
-	spin_unlock(&bdev_lock);
-	return 0;
-}
-EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */
-
-static void bd_clear_claiming(struct block_device *whole, void *holder)
-{
-	lockdep_assert_held(&bdev_lock);
-	/* tell others that we're done */
-	BUG_ON(whole->bd_claiming != holder);
-	whole->bd_claiming = NULL;
-	wake_up_bit(&whole->bd_claiming, 0);
-}
-
-/**
- * bd_finish_claiming - finish claiming of a block device
- * @bdev: block device of interest
- * @holder: holder that has claimed @bdev
- *
- * Finish exclusive open of a block device. Mark the device as exlusively
- * open by the holder and wake up all waiters for exclusive open to finish.
- */
-static void bd_finish_claiming(struct block_device *bdev, void *holder)
-{
-	struct block_device *whole = bdev_whole(bdev);
-
-	spin_lock(&bdev_lock);
-	BUG_ON(!bd_may_claim(bdev, whole, holder));
-	/*
-	 * Note that for a whole device bd_holders will be incremented twice,
-	 * and bd_holder will be set to bd_may_claim before being set to holder
-	 */
-	whole->bd_holders++;
-	whole->bd_holder = bd_may_claim;
-	bdev->bd_holders++;
-	bdev->bd_holder = holder;
-	bd_clear_claiming(whole, holder);
-	spin_unlock(&bdev_lock);
-}
-
-/**
- * bd_abort_claiming - abort claiming of a block device
- * @bdev: block device of interest
- * @holder: holder that has claimed @bdev
- *
- * Abort claiming of a block device when the exclusive open failed. This can be
- * also used when exclusive open is not actually desired and we just needed
- * to block other exclusive openers for a while.
- */
-void bd_abort_claiming(struct block_device *bdev, void *holder)
-{
-	spin_lock(&bdev_lock);
-	bd_clear_claiming(bdev_whole(bdev), holder);
-	spin_unlock(&bdev_lock);
-}
-EXPORT_SYMBOL(bd_abort_claiming);
-
-static void blkdev_flush_mapping(struct block_device *bdev)
-{
-	WARN_ON_ONCE(bdev->bd_holders);
-	sync_blockdev(bdev);
-	kill_bdev(bdev);
-	bdev_write_inode(bdev);
-}
-
-static int blkdev_get_whole(struct block_device *bdev, fmode_t mode)
-{
-	struct gendisk *disk = bdev->bd_disk;
-	int ret = 0;
-
-	if (disk->fops->open) {
-		ret = disk->fops->open(bdev, mode);
-		if (ret) {
-			/* avoid ghost partitions on a removed medium */
-			if (ret == -ENOMEDIUM &&
-			     test_bit(GD_NEED_PART_SCAN, &disk->state))
-				bdev_disk_changed(disk, true);
-			return ret;
-		}
-	}
-
-	if (!bdev->bd_openers)
-		set_init_blocksize(bdev);
-	if (test_bit(GD_NEED_PART_SCAN, &disk->state))
-		bdev_disk_changed(disk, false);
-	bdev->bd_openers++;
-	return 0;;
-}
-
-static void blkdev_put_whole(struct block_device *bdev, fmode_t mode)
-{
-	if (!--bdev->bd_openers)
-		blkdev_flush_mapping(bdev);
-	if (bdev->bd_disk->fops->release)
-		bdev->bd_disk->fops->release(bdev->bd_disk, mode);
-}
-
-static int blkdev_get_part(struct block_device *part, fmode_t mode)
-{
-	struct gendisk *disk = part->bd_disk;
-	int ret;
-
-	if (part->bd_openers)
-		goto done;
-
-	ret = blkdev_get_whole(bdev_whole(part), mode);
-	if (ret)
-		return ret;
-
-	ret = -ENXIO;
-	if (!bdev_nr_sectors(part))
-		goto out_blkdev_put;
-
-	disk->open_partitions++;
-	set_init_blocksize(part);
-done:
-	part->bd_openers++;
-	return 0;
-
-out_blkdev_put:
-	blkdev_put_whole(bdev_whole(part), mode);
-	return ret;
-}
-
-static void blkdev_put_part(struct block_device *part, fmode_t mode)
-{
-	struct block_device *whole = bdev_whole(part);
-
-	if (--part->bd_openers)
-		return;
-	blkdev_flush_mapping(part);
-	whole->bd_disk->open_partitions--;
-	blkdev_put_whole(whole, mode);
-}
-
-struct block_device *blkdev_get_no_open(dev_t dev)
-{
-	struct block_device *bdev;
-	struct inode *inode;
-
-	inode = ilookup(blockdev_superblock, dev);
-	if (!inode) {
-		blk_request_module(dev);
-		inode = ilookup(blockdev_superblock, dev);
-		if (!inode)
-			return NULL;
-	}
-
-	/* switch from the inode reference to a device mode one: */
-	bdev = &BDEV_I(inode)->bdev;
-	if (!kobject_get_unless_zero(&bdev->bd_device.kobj))
-		bdev = NULL;
-	iput(inode);
-
-	if (!bdev)
-		return NULL;
-	if ((bdev->bd_disk->flags & GENHD_FL_HIDDEN) ||
-	    !try_module_get(bdev->bd_disk->fops->owner)) {
-		put_device(&bdev->bd_device);
-		return NULL;
-	}
-
-	return bdev;
-}
-
-void blkdev_put_no_open(struct block_device *bdev)
-{
-	module_put(bdev->bd_disk->fops->owner);
-	put_device(&bdev->bd_device);
-}
-
-/**
- * blkdev_get_by_dev - open a block device by device number
- * @dev: device number of block device to open
- * @mode: FMODE_* mask
- * @holder: exclusive holder identifier
- *
- * Open the block device described by device number @dev. If @mode includes
- * %FMODE_EXCL, the block device is opened with exclusive access.  Specifying
- * %FMODE_EXCL with a %NULL @holder is invalid.  Exclusive opens may nest for
- * the same @holder.
- *
- * Use this interface ONLY if you really do not have anything better - i.e. when
- * you are behind a truly sucky interface and all you are given is a device
- * number.  Everything else should use blkdev_get_by_path().
- *
- * CONTEXT:
- * Might sleep.
- *
- * RETURNS:
- * Reference to the block_device on success, ERR_PTR(-errno) on failure.
- */
-struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
-{
-	bool unblock_events = true;
-	struct block_device *bdev;
-	struct gendisk *disk;
-	int ret;
-
-	ret = devcgroup_check_permission(DEVCG_DEV_BLOCK,
-			MAJOR(dev), MINOR(dev),
-			((mode & FMODE_READ) ? DEVCG_ACC_READ : 0) |
-			((mode & FMODE_WRITE) ? DEVCG_ACC_WRITE : 0));
-	if (ret)
-		return ERR_PTR(ret);
-
-	bdev = blkdev_get_no_open(dev);
-	if (!bdev)
-		return ERR_PTR(-ENXIO);
-	disk = bdev->bd_disk;
-
-	if (mode & FMODE_EXCL) {
-		ret = bd_prepare_to_claim(bdev, holder);
-		if (ret)
-			goto put_blkdev;
-	}
-
-	disk_block_events(disk);
-
-	mutex_lock(&disk->open_mutex);
-	ret = -ENXIO;
-	if (!disk_live(disk))
-		goto abort_claiming;
-	if (bdev_is_partition(bdev))
-		ret = blkdev_get_part(bdev, mode);
-	else
-		ret = blkdev_get_whole(bdev, mode);
-	if (ret)
-		goto abort_claiming;
-	if (mode & FMODE_EXCL) {
-		bd_finish_claiming(bdev, holder);
-
-		/*
-		 * Block event polling for write claims if requested.  Any write
-		 * holder makes the write_holder state stick until all are
-		 * released.  This is good enough and tracking individual
-		 * writeable reference is too fragile given the way @mode is
-		 * used in blkdev_get/put().
-		 */
-		if ((mode & FMODE_WRITE) && !bdev->bd_write_holder &&
-		    (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) {
-			bdev->bd_write_holder = true;
-			unblock_events = false;
-		}
-	}
-	mutex_unlock(&disk->open_mutex);
-
-	if (unblock_events)
-		disk_unblock_events(disk);
-	return bdev;
-
-abort_claiming:
-	if (mode & FMODE_EXCL)
-		bd_abort_claiming(bdev, holder);
-	mutex_unlock(&disk->open_mutex);
-	disk_unblock_events(disk);
-put_blkdev:
-	blkdev_put_no_open(bdev);
-	return ERR_PTR(ret);
-}
-EXPORT_SYMBOL(blkdev_get_by_dev);
-
-/**
- * blkdev_get_by_path - open a block device by name
- * @path: path to the block device to open
- * @mode: FMODE_* mask
- * @holder: exclusive holder identifier
- *
- * Open the block device described by the device file at @path.  If @mode
- * includes %FMODE_EXCL, the block device is opened with exclusive access.
- * Specifying %FMODE_EXCL with a %NULL @holder is invalid.  Exclusive opens may
- * nest for the same @holder.
- *
- * CONTEXT:
- * Might sleep.
- *
- * RETURNS:
- * Reference to the block_device on success, ERR_PTR(-errno) on failure.
- */
-struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
-					void *holder)
-{
-	struct block_device *bdev;
-	dev_t dev;
-	int error;
-
-	error = lookup_bdev(path, &dev);
-	if (error)
-		return ERR_PTR(error);
-
-	bdev = blkdev_get_by_dev(dev, mode, holder);
-	if (!IS_ERR(bdev) && (mode & FMODE_WRITE) && bdev_read_only(bdev)) {
-		blkdev_put(bdev, mode);
-		return ERR_PTR(-EACCES);
-	}
-
-	return bdev;
-}
-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;
-
-	/*
-	 * Sync early if it looks like we're the last one.  If someone else
-	 * opens the block device between now and the decrement of bd_openers
-	 * then we did a sync that we didn't need to, but that's not the end
-	 * of the world and we want to avoid long (could be several minute)
-	 * syncs while holding the mutex.
-	 */
-	if (bdev->bd_openers == 1)
-		sync_blockdev(bdev);
-
-	mutex_lock(&disk->open_mutex);
-	if (mode & FMODE_EXCL) {
-		struct block_device *whole = bdev_whole(bdev);
-		bool bdev_free;
-
-		/*
-		 * Release a claim on the device.  The holder fields
-		 * are protected with bdev_lock.  open_mutex is to
-		 * synchronize disk_holder unlinking.
-		 */
-		spin_lock(&bdev_lock);
-
-		WARN_ON_ONCE(--bdev->bd_holders < 0);
-		WARN_ON_ONCE(--whole->bd_holders < 0);
-
-		if ((bdev_free = !bdev->bd_holders))
-			bdev->bd_holder = NULL;
-		if (!whole->bd_holders)
-			whole->bd_holder = NULL;
-
-		spin_unlock(&bdev_lock);
-
-		/*
-		 * If this was the last claim, remove holder link and
-		 * unblock evpoll if it was a write holder.
-		 */
-		if (bdev_free && bdev->bd_write_holder) {
-			disk_unblock_events(disk);
-			bdev->bd_write_holder = false;
-		}
-	}
-
-	/*
-	 * Trigger event checking and tell drivers to flush MEDIA_CHANGE
-	 * event.  This is to ensure detection of media removal commanded
-	 * from userland - e.g. eject(1).
-	 */
-	disk_flush_events(disk, DISK_EVENT_MEDIA_CHANGE);
-
-	if (bdev_is_partition(bdev))
-		blkdev_put_part(bdev, mode);
-	else
-		blkdev_put_whole(bdev, mode);
-	mutex_unlock(&disk->open_mutex);
-
-	blkdev_put_no_open(bdev);
-}
-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
- * @dev:	return value of the block device's dev_t
- *
- * Get a reference to the blockdevice at @pathname in the current
- * namespace if possible and return it.  Return ERR_PTR(error)
- * otherwise.
- */
-int lookup_bdev(const char *pathname, dev_t *dev)
-{
-	struct inode *inode;
-	struct path path;
-	int error;
-
-	if (!pathname || !*pathname)
-		return -EINVAL;
-
-	error = kern_path(pathname, LOOKUP_FOLLOW, &path);
-	if (error)
-		return error;
-
-	inode = d_backing_inode(path.dentry);
-	error = -ENOTBLK;
-	if (!S_ISBLK(inode->i_mode))
-		goto out_path_put;
-	error = -EACCES;
-	if (!may_open_dev(&path))
-		goto out_path_put;
-
-	*dev = inode->i_rdev;
-	error = 0;
-out_path_put:
-	path_put(&path);
-	return error;
-}
-EXPORT_SYMBOL(lookup_bdev);
-
-int __invalidate_device(struct block_device *bdev, bool kill_dirty)
-{
-	struct super_block *sb = get_super(bdev);
-	int res = 0;
-
-	if (sb) {
-		/*
-		 * no need to lock the super, get_super holds the
-		 * read mutex so the filesystem cannot go away
-		 * under us (->put_super runs with the write lock
-		 * hold).
-		 */
-		shrink_dcache_sb(sb);
-		res = invalidate_inodes(sb, kill_dirty);
-		drop_super(sb);
-	}
-	invalidate_bdev(bdev);
-	return res;
-}
-EXPORT_SYMBOL(__invalidate_device);
-
-void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg)
-{
-	struct inode *inode, *old_inode = NULL;
-
-	spin_lock(&blockdev_superblock->s_inode_list_lock);
-	list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) {
-		struct address_space *mapping = inode->i_mapping;
-		struct block_device *bdev;
-
-		spin_lock(&inode->i_lock);
-		if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) ||
-		    mapping->nrpages == 0) {
-			spin_unlock(&inode->i_lock);
-			continue;
-		}
-		__iget(inode);
-		spin_unlock(&inode->i_lock);
-		spin_unlock(&blockdev_superblock->s_inode_list_lock);
-		/*
-		 * We hold a reference to 'inode' so it couldn't have been
-		 * removed from s_inodes list while we dropped the
-		 * s_inode_list_lock  We cannot iput the inode now as we can
-		 * be holding the last reference and we cannot iput it under
-		 * s_inode_list_lock. So we keep the reference and iput it
-		 * later.
-		 */
-		iput(old_inode);
-		old_inode = inode;
-		bdev = I_BDEV(inode);
-
-		mutex_lock(&bdev->bd_disk->open_mutex);
-		if (bdev->bd_openers)
-			func(bdev, arg);
-		mutex_unlock(&bdev->bd_disk->open_mutex);
-
-		spin_lock(&blockdev_superblock->s_inode_list_lock);
-	}
-	spin_unlock(&blockdev_superblock->s_inode_list_lock);
-	iput(old_inode);
-}
diff --git a/fs/internal.h b/fs/internal.h
index 68a2ae029a27..3cd065c8a66b 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -18,7 +18,7 @@ struct user_namespace;
 struct pipe_inode_info;
 
 /*
- * block_dev.c
+ * block/bdev.c
  */
 #ifdef CONFIG_BLOCK
 extern void __init bdev_cache_init(void);