Release 4.7 fs/block_dev.c

/*
 *  linux/fs/block_dev.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 2001  Andrea Arcangeli <andrea@suse.de> SuSE
 */

#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/uio.h>
#include <linux/namei.h>
#include <linux/log2.h>
#include <linux/cleancache.h>
#include <linux/dax.h>
#include <linux/badblocks.h>
#include <asm/uaccess.h>
#include "internal.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);
}

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struct block_device *I_BDEV(struct inode *inode)
{
	return &BDEV_I(inode)->bdev;
}
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EXPORT_SYMBOL(I_BDEV);



void __vfs_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	va_start(args, fmt);
	vaf.fmt = fmt;
	vaf.va = &args;
	printk_ratelimited("%sVFS (%s): %pV\n", prefix, sb->s_id, &vaf);
	va_end(args);
}

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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);
}

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vivek goyal
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dave chinner
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christoph hellwig
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jan kara
jan kara
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tejun heo
tejun heo
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/* Kill _all_ buffers and pagecache , dirty or not.. */


void kill_bdev(struct block_device *bdev)
{
	struct address_space *mapping = bdev->bd_inode->i_mapping;

	if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
		return;

	invalidate_bh_lrus();
	truncate_inode_pages(mapping, 0);
}	
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al viro
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linus torvalds
linus torvalds
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peter zijlstra
peter zijlstra
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johannes weiner
johannes weiner
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ross zwisler
ross zwisler
1
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EXPORT_SYMBOL(kill_bdev);

/* 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 == 0)
		return;

	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);
}
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al viro
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linus torvalds
linus torvalds
10
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dan magenheimer
dan magenheimer
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1
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53
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EXPORT_SYMBOL(invalidate_bdev);



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_block_size != size) {
		sync_blockdev(bdev);
		bdev->bd_block_size = size;
		bdev->bd_inode->i_blkbits = blksize_bits(size);
		kill_bdev(bdev);
	}
	return 0;
}

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linus torvalds
linus torvalds
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al viro
al viro
12
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mika kukkonen
mika kukkonen
6
6.74%
1
10.00%
vignesh babu
vignesh babu
4
4.49%
1
10.00%
martin k. petersen
martin k. petersen
1
1.12%
1
10.00%
andrew morton
andrew morton
1
1.12%
1
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89
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10
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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;
}

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linus torvalds
linus torvalds
42
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coywolf qi hunt
coywolf qi hunt
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al viro
al viro
1
2.08%
1
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mika kukkonen
mika kukkonen
1
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48
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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);
}

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linus torvalds
linus torvalds
39
95.12%
1
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martin k. petersen
martin k. petersen
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2.44%
1
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al viro
al viro
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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;
}

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andrew morton
andrew morton
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linus torvalds
linus torvalds
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kenneth w. chen
kenneth w. chen
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static struct inode *bdev_file_inode(struct file *file)
{
	return file->f_mapping->host;
}

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dan williams
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static ssize_t

blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
	struct file *file = iocb->ki_filp;
	struct inode *inode = bdev_file_inode(file);

	if (IS_DAX(inode))
		return dax_do_io(iocb, inode, iter, blkdev_get_block,
				NULL, DIO_SKIP_DIO_COUNT);
	return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), iter,
				    blkdev_get_block, NULL, NULL,
				    DIO_SKIP_DIO_COUNT);
}

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andrew morton
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matthew wilcox
matthew wilcox
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linus torvalds
linus torvalds
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christoph hellwig
christoph hellwig
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al viro
al viro
3
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1
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dan williams
dan williams
3
3.70%
1
6.25%
chuck lever
chuck lever
2
2.47%
1
6.25%
kenneth w. chen
kenneth w. chen
1
1.23%
1
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jens axboe
jens axboe
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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);
}

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jan kara
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nick piggin
nick piggin
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/*
 * 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);
}
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jan kara
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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);
}
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nick piggin
nick piggin
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jan kara
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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.
 */


struct super_block *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) {
		/*
                 * We don't even need to grab a reference - the first call
                 * to freeze_bdev grab an active reference and only the last
                 * thaw_bdev drops it.
                 */
		sb = get_super(bdev);
		drop_super(sb);
		mutex_unlock(&bdev->bd_fsfreeze_mutex);
		return sb;
	}

	sb = get_active_super(bdev);
	if (!sb)
		goto out;
	if (sb->s_op->freeze_super)
		error = sb->s_op->freeze_super(sb);
	else
		error = freeze_super(sb);
	if (error) {
		deactivate_super(sb);
		bdev->bd_fsfreeze_count--;
		mutex_unlock(&bdev->bd_fsfreeze_mutex);
		return ERR_PTR(error);
	}
	deactivate_super(sb);
 out:
	sync_blockdev(bdev);
	mutex_unlock(&bdev->bd_fsfreeze_mutex);
	return sb;	/* thaw_bdev releases s->s_umount */
}
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nick piggin
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christoph hellwig
christoph hellwig
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benjamin marzinski
benjamin marzinski
20
12.42%
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josef bacik
josef bacik
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EXPORT_SYMBOL(freeze_bdev);

/**
 * thaw_bdev  -- unlock filesystem
 * @bdev:       blockdevice to unlock
 * @sb:         associated superblock
 *
 * 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;

	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++;
		mutex_unlock(&bdev->bd_fsfreeze_mutex);
		return error;
	}
out:
	mutex_unlock(&bdev->bd_fsfreeze_mutex);
	return 0;
}
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nick piggin
nick piggin
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benjamin marzinski
benjamin marzinski
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christoph hellwig
christoph hellwig
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josef bacik
josef bacik
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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);
}

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linus torvalds
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andrew morton
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static int blkdev_readpage(struct file * file, struct page * page)
{
	return block_read_full_page(page, blkdev_get_block);
}

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linus torvalds
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static int blkdev_readpages(struct file *file, struct address_space *mapping,
			struct list_head *pages, unsigned nr_pages)
{
	return mpage_readpages(mapping, pages, nr_pages, blkdev_get_block);
}

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akinobu mita
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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);
}

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nick piggin
nick piggin
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linus torvalds
linus torvalds
21
40.38%
3
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pre-git
pre-git
2
3.85%
1
16.67%
christoph hellwig
christoph hellwig
1
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1
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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;
}

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nick piggin
nick piggin
46
66.67%
1
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linus torvalds
linus torvalds
20
28.99%
1
25.00%
pre-git
pre-git
2
2.90%
1
25.00%
kirill a. shutemov
kirill a. shutemov
1
1.45%
1
25.00%
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69
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4
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/*
 * 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;
}
	
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andrew morton
andrew morton
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pre-git
19
32.20%
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al viro
al viro
12
20.34%
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dan williams
dan williams
3
5.08%
1
10.00%
linus torvalds
linus torvalds
3
5.08%
2
20.00%
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59
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10
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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 = filemap_write_and_wait_range(filp->f_mapping, 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, GFP_KERNEL, NULL);
	if (error == -EOPNOTSUPP)
		error = 0;

	return error;
}
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christoph hellwig
christoph hellwig
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rafael j. wysocki
rafael j. wysocki
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22.73%
1
9.09%
pre-git
pre-git
13
14.77%
3
27.27%
anton blanchard
anton blanchard
12
13.64%
1
9.09%
josef bacik
josef bacik
6
6.82%
1
9.09%
andrew morton
andrew morton
3
3.41%
2
18.18%
dan williams
dan williams
3
3.41%
1
9.09%
dmitriy monakhov
dmitriy monakhov
2
2.27%
1
9.09%
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88
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11
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EXPORT_SYMBOL(blkdev_fsync);

/**
 * 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_queue, false);
	if (result)
		return result;
	result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ);
	blk_queue_exit(bdev->bd_queue);
	return result;
}
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matthew wilcox
matthew wilcox
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dan williams
dan williams
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vishal verma
vishal verma
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christoph hellwig
christoph hellwig
1
1.01%
1
25.00%
Total
99
100.00%
4
100.00%


EXPORT_SYMBOL_GPL(bdev_read_page);

/**
 * 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;
	int rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE;
	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_queue, false);
	if (result)
		return result;

	set_page_writeback(page);
	result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, rw);
	if (result)
		end_page_writeback(page);
	else
		unlock_page(page);
	blk_queue_exit(bdev->bd_queue);
	return result;
}
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matthew wilcox
matthew wilcox
107
78.10%
1
25.00%
dan williams
dan williams
24
17.52%
1
25.00%
vishal verma
vishal verma
5
3.65%
1
25.00%
christoph hellwig
christoph hellwig
1
0.73%
1
25.00%
Total
137
100.00%
4
100.00%


EXPORT_SYMBOL_GPL(bdev_write_page);

/**
 * bdev_direct_access() - Get the address for directly-accessibly memory
 * @bdev: The device containing the memory
 * @dax: control and output parameters for ->direct_access
 *
 * If a block device is made up of directly addressable memory, this function
 * will tell the caller the PFN and the address of the memory.  The address
 * may be directly dereferenced within the kernel without the need to call
 * ioremap(), kmap() or similar.  The PFN is suitable for inserting into
 * page tables.
 *
 * Return: negative errno if an error occurs, otherwise the number of bytes
 * accessible at this address.
 */


long bdev_direct_access(struct block_device *bdev, struct blk_dax_ctl *dax)
{
	sector_t sector = dax->sector;
	long avail, size = dax->size;
	const struct block_device_operations *ops = bdev->bd_disk->fops;

	/*
         * The device driver is allowed to sleep, in order to make the
         * memory directly accessible.
         */
	might_sleep();

	if (size < 0)
		return size;
	if (!ops->direct_access)
		return -EOPNOTSUPP;
	if ((sector + DIV_ROUND_UP(size, 512)) >
					part_nr_sects_read(bdev->bd_part))
		return -ERANGE;
	sector += get_start_sect(bdev);
	if (sector % (PAGE_SIZE / 512))
		return -EINVAL;
	avail = ops->direct_access(bdev, sector, &dax->addr, &dax->pfn, size);
	if (!avail)
		return -ERANGE;
	if (avail > 0 && avail & ~PAGE_MASK)
		return -ENXIO;
	return min(avail, size);
}
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matthew wilcox
matthew wilcox
128
76.65%
2
40.00%
dan williams
dan williams
39
23.35%
3
60.00%
Total
167
100.00%
5
100.00%


EXPORT_SYMBOL_GPL(bdev_direct_access);

/**
 * bdev_dax_supported() - Check if the device supports dax for filesystem
 * @sb: The superblock of the device
 * @blocksize: The block size of the device
 *
 * This is a library function for filesystems to check if the block device
 * can be mounted with dax option.
 *
 * Return: negative errno if unsupported, 0 if supported.
 */


int bdev_dax_supported(struct super_block *sb, int blocksize)
{
	struct blk_dax_ctl dax = {
		.sector = 0,
		.size = PAGE_SIZE,
        };
	int err;

	if (blocksize != PAGE_SIZE) {
		vfs_msg(sb, KERN_ERR, "error: unsupported blocksize for dax");
		return -EINVAL;
	}

	err = bdev_direct_access(sb->s_bdev, &dax);
	if (err < 0) {
		switch (err) {
		case -EOPNOTSUPP:
			vfs_msg(sb, KERN_ERR,
				"error: device does not support dax");
			break;
		case -EINVAL:
			vfs_msg(sb, KERN_ERR,
				"error: unaligned partition for dax");
			break;
		default:
			vfs_msg(sb, KERN_ERR,
				"error: dax access failed (%d)", err);
		}
		return err;
	}

	return 0;
}
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toshi kani
toshi kani
125
100.00%
1
100.00%
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125
100.00%
1
100.00%


EXPORT_SYMBOL_GPL(bdev_dax_supported);

/**
 * bdev_dax_capable() - Return if the raw device is capable for dax
 * @bdev: The device for raw block device access
 */


bool bdev_dax_capable(struct block_device *bdev)
{
	struct blk_dax_ctl dax = {
		.size = PAGE_SIZE,
        };

	if (!IS_ENABLED(CONFIG_FS_DAX))
		return false;

	dax.sector = 0;
	if (bdev_direct_access(bdev, &dax) < 0)
		return false;

	dax.sector = bdev->bd_part->nr_sects - (PAGE_SIZE / 512);
	if (bdev_direct_access(bdev, &dax) < 0)
		return false;

	return true;
}

Contributors
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toshi kani
toshi kani
87
100.00%
1
100.00%
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87
100.00%
1
100.00%

/*
 * 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;
	return &ei->vfs_inode;
}

Contributors
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al viro
al viro
28
71.79%
1
20.00%
pre-git
pre-git
4
10.26%
1
20.00%
andrew morton
andrew morton
3
7.69%
1
20.00%
linus torvalds
linus torvalds
3
7.69%
1
20.00%
christoph lameter
christoph lameter
1
2.56%
1
20.00%
Total
39
100.00%
5
100.00%



static void bdev_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);
	struct bdev_inode *bdi = BDEV_I(inode);

	kmem_cache_free(bdev_cachep, bdi);
}

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nick piggin
nick piggin
20
46.51%
1
25.00%
andrew morton
andrew morton
11
25.58%
1
25.00%
al viro
al viro
10
23.26%
1
25.00%
pre-git
pre-git
2
4.65%
1
25.00%
Total
43
100.00%
4
100.00%



static void bdev_destroy_inode(struct inode *inode)
{
	call_rcu(&inode->i_rcu, bdev_i_callback);
}

Contributors
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nick piggin
nick piggin
19
90.48%
1
50.00%
al viro
al viro
2
9.52%
1
50.00%
Total
21
100.00%
2
100.00%



static void init_once(void *foo)
{
	struct bdev_inode *ei = (struct bdev_inode *) foo;
	struct block_device *bdev = &ei->bdev;

	memset(bdev, 0, sizeof(*bdev));
	mutex_init(&bdev->bd_mutex);
	INIT_LIST_HEAD(&bdev->bd_inodes);
	INIT_LIST_HEAD(&bdev->bd_list);
#ifdef CONFIG_SYSFS
	INIT_LIST_HEAD(&bdev->bd_holder_disks);
#endif
	inode_init_once(&ei->vfs_inode);
	/* Initialize mutex for freeze. */
	mutex_init(&bdev->bd_fsfreeze_mutex);
}

Contributors
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al viro
al viro
57
57.58%
1
16.67%
pre-git
pre-git
15
15.15%
1
16.67%
tejun heo
tejun heo
13
13.13%
1
16.67%
takashi sato
takashi sato
9
9.09%
1
16.67%
christoph lameter
christoph lameter
3
3.03%
1
16.67%
arjan van de ven
arjan van de ven
2
2.02%
1
16.67%
Total
99
100.00%
6
100.00%



static inline void __bd_forget(struct inode *inode)
{
	list_del_init(&inode->i_devices);
	inode->i_bdev = NULL;
	inode->i_mapping = &inode->i_data;
}

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al viro
al viro
35
100.00%
1
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35
100.00%
1
100.00%



static void bdev_evict_inode(struct inode *inode)
{
	struct block_device *bdev = &BDEV_I(inode)->bdev;
	struct list_head *p;
	truncate_inode_pages_final(&inode->i_data);
	invalidate_inode_buffers(inode); /* is it needed here? */
	clear_inode(inode);
	spin_lock(&bdev_lock);
	while ( (p = bdev->bd_inodes.next) != &bdev->bd_inodes ) {
		__bd_forget(list_entry(p, struct inode, i_devices));
	}
	list_del_init(&bdev->bd_list);
	spin_unlock(&bdev_lock);
}

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al viro
al viro
98
98.00%
2
50.00%
jan kara
jan kara
1
1.00%
1
25.00%
johannes weiner
johannes weiner
1
1.00%
1
25.00%
Total
100
100.00%
4
100.00%


static const struct super_operations bdev_sops = {
	.statfs = simple_statfs,
	.alloc_inode = bdev_alloc_inode,
	.destroy_inode = bdev_destroy_inode,
	.drop_inode = generic_delete_inode,
	.evict_inode = bdev_evict_inode,
};



static struct dentry *bd_mount(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data)
{
	struct dentry *dent;
	dent = mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, BDEVFS_MAGIC);
	if (dent)
		dent->d_sb->s_iflags |= SB_I_CGROUPWB;
	return dent;
}

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al viro
al viro
31
50.82%
3
42.86%
shaohua li
shaohua li
22
36.07%
1
14.29%
pre-git
pre-git
6
9.84%
1
14.29%
muthu kumar
muthu kumar
1
1.64%
1
14.29%
linus torvalds
linus torvalds
1
1.64%
1
14.29%
Total
61
100.00%
7
100.00%


static struct file_system_type bd_type = {
	.name		= "bdev",
	.mount		= bd_mount,
	.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 */
}

Contributors
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linus torvalds
linus torvalds
40
44.44%
2
16.67%
pre-git
pre-git
26
28.89%
2
16.67%
andrew morton
andrew morton
9
10.00%
2
16.67%
cheng renquan
cheng renquan
5
5.56%
1
8.33%
paul jackson
paul jackson
4
4.44%
2
16.67%
al viro
al viro
3
3.33%
1
8.33%
vladimir davydov
vladimir davydov
2
2.22%
1
8.33%
sergey senozhatsky
sergey senozhatsky
1
1.11%
1
8.33%
Total
90
100.00%
12
100.00%

/*
 * Most likely _very_ bad one - but then it's hardly critical for small
 * /dev and can be fixed when somebody will need really large one.
 * Keep in mind that it will be fed through icache hash function too.
 */


static inline unsigned long hash(dev_t dev)
{
	return MAJOR(dev)+MINOR(dev);
}

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linus torvalds
linus torvalds
11
50.00%
1
33.33%
al viro
al viro
8
36.36%
1
33.33%
pre-git
pre-git
3
13.64%
1
33.33%
Total
22
100.00%
3
100.00%



static int bdev_test(struct inode *inode, void *data)
{
	return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data;
}

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al viro
al viro
25
78.12%
1
50.00%
pre-git
pre-git
7
21.88%
1
50.00%
Total
32
100.00%
2
100.00%



static int bdev_set(struct inode *inode, void *data)
{
	BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data;
	return 0;
}

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al viro
al viro
22
64.71%
1
50.00%
pre-git
pre-git
12
35.29%
1
50.00%
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34
100.00%
2
100.00%

static LIST_HEAD(all_bdevs);



struct block_device *bdget(dev_t dev)
{
	struct block_device *bdev;
	struct inode *inode;

	inode = iget5_locked(blockdev_superblock, hash(dev),
			bdev_test, bdev_set, &dev);

	if (!inode)
		return NULL;

	bdev = &BDEV_I(inode)->bdev;

	if (inode->i_state & I_NEW) {
		bdev->bd_contains = NULL;
		bdev->bd_super = NULL;
		bdev->bd_inode = inode;
		bdev->bd_block_size = (1 << inode->i_blkbits);
		bdev->bd_part_count = 0;
		bdev->bd_invalidated = 0;
		inode->i_mode = S_IFBLK;
		inode->i_rdev = dev;
		inode->i_bdev = bdev;
		inode->i_data.a_ops = &def_blk_aops;
		mapping_set_gfp_mask(&inode->i_data, GFP_USER);
		spin_lock(&bdev_lock);
		list_add(&bdev->bd_list, &all_bdevs);
		spin_unlock(&bdev_lock);
		unlock_new_inode(inode);
	}
	return bdev;
}

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al viro
al viro
62
35.03%
4
26.67%
linus torvalds
linus torvalds
47
26.55%
5
33.33%
pre-git
pre-git
45
25.42%
2
13.33%
andrew morton
andrew morton
16
9.04%
2
13.33%
lachlan mcilroy
lachlan mcilroy
6
3.39%
1
6.67%
cheng renquan
cheng renquan
1
0.56%
1
6.67%
Total
177
100.00%
15
100.00%


EXPORT_SYMBOL(bdget);

/**
 * bdgrab -- Grab a reference to an already referenced block device
 * @bdev:       Block device to grab a reference to.
 */


struct block_device *bdgrab(struct block_device *bdev)
{
	ihold(bdev->bd_inode);
	return bdev;
}
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alan jenkins
alan jenkins
21
95.45%
1
50.00%
al viro
al viro
1
4.55%
1
50.00%
Total
22
100.00%
2
100.00%


EXPORT_SYMBOL(bdgrab);



long nr_blockdev_pages(void)
{
	struct block_device *bdev;
	long ret = 0;
	spin_lock(&bdev_lock);
	list_for_each_entry(bdev, &all_bdevs, bd_list) {
		ret += bdev->bd_inode->i_mapping->nrpages;
	}
	spin_unlock(&bdev_lock);
	return ret;
}

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andrew morton
andrew morton
42
80.77%
1
33.33%
matthias kaehlcke
matthias kaehlcke
6
11.54%
1
33.33%
al viro
al viro
4
7.69%
1
33.33%
Total
52
100.00%
3
100.00%



void bdput(struct block_device *bdev)
{
	iput(bdev->bd_inode);
}

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pre-git
pre-git
9
52.94%
1
33.33%
linus torvalds
linus torvalds
8
47.06%
2
66.67%
Total
17
100.00%
3
100.00%


EXPORT_SYMBOL(bdput);
 


static struct block_device *bd_acquire(struct inode *inode)
{
	struct block_device *bdev;

	spin_lock(&bdev_lock);
	bdev = inode->i_bdev;
	if (bdev) {
		bdgrab(bdev);
		spin_unlock(&bdev_lock);
		return bdev;
	}
	spin_unlock(&bdev_lock);

	bdev = bdget(inode->i_rdev);
	if (bdev) {
		spin_lock(&bdev_lock);
		if (!inode->i_bdev) {
			/*
                         * We take an additional reference to bd_inode,
                         * and it's released in clear_inode() of inode.
                         * So, we can access it via ->i_mapping always
                         * without igrab().
                         */
			bdgrab(bdev);
			inode->i_bdev = bdev;
			inode->i_mapping = bdev->bd_inode->i_mapping;
			list_add(&inode->i_devices, &bdev->bd_inodes);
		}
		spin_unlock(&bdev_lock);
	}
	return bdev;
}

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linus torvalds
linus torvalds
90
69.23%
3
33.33%
andrew morton
andrew morton
15
11.54%
1
11.11%
pre-git
pre-git
12
9.23%
1
11.11%
hirofumi ogawa
hirofumi ogawa
7
5.38%
1
11.11%
al viro
al viro
4
3.08%
2
22.22%
ilya dryomov
ilya dryomov
2
1.54%
1
11.11%
Total
130
100.00%
9
100.00%

/* Call when you free inode */



void bd_forget(struct inode *inode)
{
	struct block_device *bdev = NULL;

	spin_lock(&bdev_lock);
	if (!sb_is_blkdev_sb(inode->i_sb))
		bdev = inode->i_bdev;
	__bd_forget(inode);
	spin_unlock(&bdev_lock);

	if (bdev)
		bdput(bdev);
}

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linus torvalds
linus torvalds
28
47.46%
2
33.33%
hirofumi ogawa
hirofumi ogawa
25
42.37%
1
16.67%
cheng renquan
cheng renquan
4
6.78%
1
16.67%
pre-git
pre-git
1
1.69%
1
16.67%
ilya dryomov
ilya dryomov
1
1.69%
1
16.67%
Total
59
100.00%
6
100.00%

/**
 * 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 (bdev->bd_contains == 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 */
}

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andrew morton
andrew morton
40
44.94%
1
25.00%
tejun heo
tejun heo
31
34.83%
2
50.00%
al viro
al viro
18
20.22%
1
25.00%
Total
89
100.00%
4
100.00%

/**
 * bd_prepare_to_claim - prepare to claim a block device
 * @bdev: block device of interest
 * @whole: the whole device containing @bdev, may equal @bdev
 * @holder: holder trying to claim @bdev
 *
 * Prepare to claim @bdev.  This function fails if @bdev is already
 * claimed by another holder and waits if another claiming is in
 * progress.  This function doesn't actually claim.  On successful
 * return, the caller has ownership of bd_claiming and bd_holder[s].
 *
 * CONTEXT:
 * spin_lock(&bdev_lock).  Might release bdev_lock, sleep and regrab
 * it multiple times.
 *
 * RETURNS:
 * 0 if @bdev can be claimed, -EBUSY otherwise.
 */


static int bd_prepare_to_claim(struct block_device *bdev,
			       struct block_device *whole, void *holder)
{
retry:
	/* if someone else claimed, fail */
	if (!bd_may_claim(bdev, whole, holder))
		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);
		spin_lock(&bdev_lock);
		goto retry;
	}

	/* yay, all mine */
	return 0;
}

Contributors
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tejun heo
tejun heo
107
100.00%
2
100.00%
Total
107
100.00%
2
100.00%

/**
 * bd_start_claiming - start claiming a block device
 * @bdev: block device of interest
 * @holder: holder trying to claim @bdev
 *
 * @bdev is about to be opened exclusively.  Check @bdev can be opened
 * exclusively and mark that an exclusive open is in progress.  Each
 * successful call to this function must be matched with a call to
 * either bd_finish_claiming() or bd_abort_claiming() (which do not
 * fail).
 *
 * This function is used to gain exclusive access to the block device
 * without actually causing other exclusive open attempts to fail. It
 * should be used when the open sequence itself requires exclusive
 * access but may subsequently fail.
 *
 * CONTEXT:
 * Might sleep.
 *
 * RETURNS:
 * Pointer to the block device containing @bdev on success, ERR_PTR()
 * value on failure.
 */


static struct block_device *bd_start_claiming(struct block_device *bdev,
					      void *holder)
{
	struct gendisk *disk;
	struct block_device *whole;
	int partno, err;

	might_sleep();

	/*
         * @bdev might not have been initialized properly yet, look up
         * and grab the outer block device the hard way.
         */
	disk = get_gendisk(bdev->bd_dev, &partno);
	if (!disk)
		return ERR_PTR(-ENXIO);

	/*
         * Normally, @bdev should equal what's returned from bdget_disk()
         * if partno is 0; however, some drivers (floppy) use multiple
         * bdev's for the same physical device and @bdev may be one of the
         * aliases.  Keep @bdev if partno is 0.  This means claimer
         * tracking is broken for those devices but it has always been that
         * way.
         */
	if (partno)
		whole = bdget_disk(disk, 0);
	else
		whole = bdgrab(bdev);

	module_put(disk->fops->owner);
	put_disk(disk);
	if (!whole)
		return ERR_PTR(-ENOMEM);

	/* prepare to claim, if successful, mark claiming in progress */
	spin_lock(&bdev_lock);

	err = bd_prepare_to_claim(bdev, whole, holder);
	if (err == 0) {
		whole->bd_claiming = holder;
		spin_unlock(&bdev_lock);
		return whole;
	} else {
		spin_unlock(&bdev_lock);
		bdput(whole);
		return ERR_PTR(err);
	}
}

Contributors
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tejun heo
tejun heo
160
94.67%
2
66.67%
nick piggin
nick piggin
9
5.33%
1
33.33%
Total
169
100.00%
3
100.00%

#ifdef CONFIG_SYSFS

struct bd_holder_disk {
	
struct list_head	list;
	
struct gendisk		*disk;
	
int			refcnt;
};



static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev,
						  struct gendisk *disk)
{
	struct bd_holder_disk *holder;

	list_for_each_entry(holder, &bdev->bd_holder_disks, list)
		if (holder->disk == disk)
			return holder;
	return NULL;
}

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tejun heo
tejun heo
45
100.00%
1
100.00%
Total
45
100.00%
1
100.00%



static int add_symlink(struct kobject *from, struct kobject *to)
{
	return sysfs_create_link(from, to, kobject_name(to));
}

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tejun heo
tejun heo
14
48.28%
1
33.33%
jun'ichi nomura
jun'ichi nomura
12
41.38%
1
33.33%
andrew morton
andrew morton
3
10.34%
1
33.33%
Total
29
100.00%
3
100.00%



static void del_symlink(struct kobject *from, struct kobject *to)
{
	sysfs_remove_link(from, kobject_name(to));
}

Contributors
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tejun heo
tejun heo
14
53.85%
1
50.00%
jun'ichi nomura
jun'ichi nomura
12
46.15%
1
50.00%
Total
26
100.00%
2
100.00%

/**
 * bd_link_disk_holder - create symlinks between holding disk and slave bdev
 * @bdev: the claimed slave bdev
 * @disk: the holding disk
 *
 * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
 *
 * This functions creates the following sysfs symlinks.
 *
 * - from "slaves" directory of the holder @disk to the claimed @bdev
 * - from "holders" directory of the @bdev to the holder @disk
 *
 * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is
 * passed to bd_link_disk_holder(), then:
 *
 *   /sys/block/dm-0/slaves/sda --> /sys/block/sda
 *   /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
 *
 * The caller must have claimed @bdev before calling this function and
 * ensure that both @bdev and @disk are valid during the creation and
 * lifetime of these symlinks.
 *
 * CONTEXT:
 * Might sleep.
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */


int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
{
	struct bd_holder_disk *holder;
	int ret = 0;

	mutex_lock(&bdev->bd_mutex);

	WARN_ON_ONCE(!bdev->bd_holder);

	/* FIXME: remove the following once add_disk() handles errors */
	if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir))
		goto out_unlock;

	holder = bd_find_holder_disk(bdev, disk);
	if (holder) {
		holder->refcnt++;
		goto out_unlock;
	}

	holder = kzalloc(sizeof(*holder), GFP_KERNEL);
	if (!holder) {
		ret = -ENOMEM;
		goto out_unlock;
	}

	INIT_LIST_HEAD(&holder->list);
	holder->disk = disk;
	holder->refcnt = 1;

	ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
	if (ret)
		goto out_free;

	ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
	if (ret)
		goto out_del;
	/*
         * bdev could be deleted beneath us which would implicitly destroy
         * the holder directory.  Hold on to it.
         */
	kobject_get(bdev->bd_part->holder_dir);

	list_add(&holder->list, &bdev->bd_holder_disks);
	goto out_unlock;

out_del:
	del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
out_free:
	kfree(holder);
out_unlock:
	mutex_unlock(&bdev->bd_mutex);
	return ret;
}
Contributors
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tejun heo
tejun heo
181
72.40%
6
66.67%
nick piggin
nick piggin
34
13.60%
1
11.11%
jun'ichi nomura
jun'ichi nomura
28
11.20%
1
11.11%
al viro
al viro
7
2.80%
1
11.11%
Total
250
100.00%
9
100.00%


EXPORT_SYMBOL_GPL(bd_link_disk_holder);

/**
 * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder()
 * @bdev: the calimed slave bdev
 * @disk: the holding disk
 *
 * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
 *
 * CONTEXT:
 * Might sleep.
 */


void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
{
	struct bd_holder_disk *holder;

	mutex_lock(&bdev->bd_mutex);

	holder = bd_find_holder_disk(bdev, disk);

	if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
		del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
		del_symlink(bdev->bd_part->holder_dir,
			    &disk_to_dev(disk)->kobj);
		kobject_put(bdev->bd_part->holder_dir);
		list_del_init(&holder->list);
		kfree(holder);
	}

	mutex_unlock(&bdev->bd_mutex);
}
Contributors
Person
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CommitProp
tejun heo
tejun heo
82
68.91%
4
57.14%
al viro
al viro
15
12.61%
1
14.29%
jun'ichi nomura
jun'ichi nomura
15
12.61%
1
14.29%
andrew morton
andrew morton
7
5.88%
1
14.29%
Total
119
100.00%
7
100.00%


EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
#endif

/**
 * flush_disk - invalidates all buffer-cache entries on a disk
 *
 * @bdev:      struct block device to be flushed
 * @kill_dirty: flag to guide handling of dirty inodes
 *
 * Invalidates all buffer-cache entries on a disk. It should be called
 * when a disk has been changed -- either by a media change or online
 * resize.
 */


static void flush_disk(struct block_device *bdev, bool kill_dirty)
{
	if (__invalidate_device(bdev, kill_dirty)) {
		printk(KERN_WARNING "VFS: busy inodes on changed media or "
		       "resized disk %s\n",
		       bdev->bd_disk ? bdev->bd_disk->disk_name : "");
	}

	if (!bdev->bd_disk)
		return;
	if (disk_part_scan_enabled(bdev->bd_disk))
		bdev->bd_invalidated = 1;
}

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andrew patterson
andrew patterson
32
47.76%
1
20.00%
jun'ichi nomura
jun'ichi nomura
18
26.87%
1
20.00%
dmitriy monakhov
dmitriy monakhov
11
16.42%
1
20.00%
neil brown
neil brown
5
7.46%
1
20.00%
tejun heo
tejun heo
1
1.49%
1
20.00%
Total
67
100.00%
5
100.00%

/**
 * check_disk_size_change - checks for disk size change and adjusts bdev size.
 * @disk: struct gendisk to check
 * @bdev: struct bdev to adjust.
 *
 * This routine checks to see if the bdev size does not match the disk size
 * and adjusts it if it differs.
 */


void check_disk_size_change(struct gendisk *disk, struct block_device *bdev)
{
	loff_t disk_size, bdev_size;

	disk_size = (loff_t)get_capacity(disk) << 9;
	bdev_size = i_size_read(bdev->bd_inode);
	if (disk_size != bdev_size) {
		printk(KERN_INFO
		       "%s: detected capacity change from %lld to %lld\n",
		       disk->disk_name, bdev_size, disk_size);
		i_size_write(bdev->bd_inode, disk_size);
		flush_disk(bdev, false);
	}
}
Contributors
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CommitProp
andrew patterson
andrew patterson
50
63.29%
2
33.33%
jun'ichi nomura
jun'ichi nomura
22
27.85%
1
16.67%
dmitriy monakhov
dmitriy monakhov
3
3.80%
1
16.67%
tejun heo
tejun heo
2
2.53%
1
16.67%
neil brown
neil brown
2
2.53%
1
16.67%
Total
79
100.00%
6
100.00%


EXPORT_SYMBOL(check_disk_size_change);

/**
 * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back
 * @disk: struct gendisk to be revalidated
 *
 * This routine is a wrapper for lower-level driver's revalidate_disk
 * call-backs.  It is used to do common pre and post operations needed
 * for all revalidate_disk operations.
 */


int revalidate_disk(struct gendisk *disk)
{
	struct block_device *bdev;
	int ret = 0;

	if (disk->fops->revalidate_disk)
		ret = disk->fops->revalidate_disk(disk);
	blk_integrity_revalidate(disk);
	bdev = bdget_disk(disk, 0);
	if (!bdev)
		return ret;

	mutex_lock(&bdev->bd_mutex);
	check_disk_size_change(disk, bdev);
	bdev->bd_invalidated = 0;
	mutex_unlock(&bdev->bd_mutex);
	bdput(bdev);
	return ret;
}
Contributors
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andrew patterson
andrew patterson
58
59.18%
2
33.33%
jun'ichi nomura
jun'ichi nomura
27
27.55%
1
16.67%
mitsunari shigeo
mitsunari shigeo
6
6.12%
1
16.67%
martin k. petersen
martin k. petersen
5
5.10%
1
16.67%
tejun heo
tejun heo
2
2.04%
1
16.67%
Total
98
100.00%
6
100.00%


EXPORT_SYMBOL(revalidate_disk);

/*
 * This routine checks whether a removable media has been changed,
 * and invalidates all buffer-cache-entries in that case. This
 * is a relatively slow routine, so we have to try to minimize using
 * it. Thus it is called only upon a 'mount' or 'open'. This
 * is the best way of combining speed and utility, I think.
 * People changing diskettes in the middle of an operation deserve
 * to lose :-)
 */


int check_disk_change(struct block_device *bdev)
{
	struct gendisk *disk = bdev->bd_disk;
	const struct block_device_operations *bdops = disk->fops;
	unsigned int events;

	events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE |
				   DISK_EVENT_EJECT_REQUEST);
	if (!(events & DISK_EVENT_MEDIA_CHANGE))
		return 0;

	flush_disk(bdev, true);
	if (bdops->revalidate_disk)
		bdops->revalidate_disk(bdev->bd_disk);
	return 1;
}

Contributors
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CommitProp
al viro
al viro
32
39.51%
6
42.86%
tejun heo
tejun heo
18
22.22%
1
7.14%
jun'ichi nomura
jun'ichi nomura
17
20.99%
1
7.14%
pre-git
pre-git
10
12.35%
3
21.43%
neil brown
neil brown
2
2.47%
1
7.14%
andrew patterson
andrew patterson
1
1.23%
1
7.14%
alexey dobriyan
alexey dobriyan
1
1.23%
1
7.14%
Total
81
100.00%
14
100.00%


EXPORT_SYMBOL(check_disk_change);



void bd_set_size(struct block_device *bdev, loff_t size)
{
	unsigned bsize = bdev_logical_block_size(bdev);

	inode_lock(bdev->bd_inode);
	i_size_write(bdev->bd_inode, size);
	inode_unlock(bdev->bd_inode);
	while (bsize < PAGE_SIZE) {
		if (size & bsize)
			break;
		bsize <<= 1;
	}
	bdev->bd_block_size = bsize;
	bdev->bd_inode->i_blkbits = blksize_bits(bsize);
}
Contributors
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al viro
al viro
44
55.00%
2
33.33%
jun'ichi nomura
jun'ichi nomura
18
22.50%
1
16.67%
guo chao
guo chao
16
20.00%
1
16.67%
kirill a. shutemov
kirill a. shutemov
1
1.25%
1
16.67%
martin k. petersen
martin k. petersen
1
1.25%
1
16.67%
Total
80
100.00%
6
100.00%


EXPORT_SYMBOL(bd_set_size);

static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);

/*
 * bd_mutex locking:
 *
 *  mutex_lock(part->bd_mutex)
 *    mutex_lock_nested(whole->bd_mutex, 1)
 */



static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
{
	struct gendisk *disk;
	struct module *owner;
	int ret;
	int partno;
	int perm = 0;

	if (mode & FMODE_READ)
		perm |= MAY_READ;
	if (mode & FMODE_WRITE)
		perm |= MAY_WRITE;
	/*
         * hooks: /n/, see "layering violations".
         */
	if (!for_part) {
		ret = devcgroup_inode_permission(bdev->bd_inode, perm);
		if (ret != 0) {
			bdput(bdev);
			return ret;
		}
	}

 restart:

	ret = -ENXIO;
	disk = get_gendisk(bdev->bd_dev, &partno);
	if (!disk)
		goto out;
	owner = disk->fops->owner;

	disk_block_events(disk);
	mutex_lock_nested(&bdev->bd_mutex, for_part);
	if (!bdev->bd_openers) {
		bdev->bd_disk = disk;
		bdev->bd_queue = disk->queue;
		bdev->bd_contains = bdev;
		if (IS_ENABLED(CONFIG_BLK_DEV_DAX) && disk->fops->direct_access)
			bdev->bd_inode->i_flags = S_DAX;
		else
			bdev->bd_inode->i_flags = 0;

		if (!partno) {
			ret = -ENXIO;
			bdev->bd_part = disk_get_part(disk, partno);
			if (!bdev->bd_part)
				goto out_clear;

			ret = 0;
			if (disk->fops->open) {
				ret = disk->fops->open(bdev, mode);
				if (ret == -ERESTARTSYS) {
					/* Lost a race with 'disk' being
                                         * deleted, try again.
                                         * See md.c
                                         */
					disk_put_part(bdev->bd_part);
					bdev->bd_part = NULL;
					bdev->bd_disk = NULL;
					bdev->bd_queue = NULL;
					mutex_unlock(&bdev->bd_mutex);
					disk_unblock_events(disk);
					put_disk(disk);
					module_put(owner);
					goto restart;
				}
			}

			if (!ret) {
				bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
				if (!bdev_dax_capable(bdev))
					bdev->bd_inode->i_flags &= ~S_DAX;
			}

			/*
                         * If the device is invalidated, rescan partition
                         * if open succeeded or failed with -ENOMEDIUM.
                         * The latter is necessary to prevent ghost
                         * partitions on a removed medium.
                         */
			if (bdev->bd_invalidated) {
				if (!ret)
					rescan_partitions(disk, bdev);
				else if (ret == -ENOMEDIUM)
					invalidate_partitions(disk, bdev);
			}

			if (ret)
				goto out_clear;
		} else {
			struct block_device *whole;
			whole = bdget_disk(disk, 0);
			ret = -ENOMEM;
			if (!whole)
				goto out_clear;
			BUG_ON(for_part);
			ret = __blkdev_get(whole, mode, 1);
			if (ret)
				goto out_clear;
			bdev->bd_contains = whole;
			bdev->bd_part = disk_get_part(disk, partno);
			if (!(disk->flags & GENHD_FL_UP) ||
			    !bdev->bd_part || !bdev->bd_part->nr_sects) {
				ret = -ENXIO;
				goto out_clear;
			}
			bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
			if (!bdev_dax_capable(bdev))
				bdev->bd_inode->i_flags &= ~S_DAX;
		}
	} else {
		if (bdev->bd_contains == bdev) {
			ret = 0;
			if (bdev->bd_disk->fops->open)
				ret = bdev->bd_disk->fops->open(bdev, mode);
			/* the same as first opener case, read comment there */
			if (bdev->bd_invalidated) {
				if (!ret)
					rescan_partitions(bdev->bd_disk, bdev);
				else if (ret == -ENOMEDIUM)
					invalidate_partitions(bdev->bd_disk, bdev);
			}
			if (ret)
				goto out_unlock_bdev;
		}
		/* only one opener holds refs to the module and disk */
		put_disk(disk);
		module_put(owner);
	}
	bdev->bd_openers++;
	if (for_part)
		bdev->bd_part_count++;
	mutex_unlock(&bdev->bd_mutex);
	disk_unblock_events(disk);
	return 0;

 out_clear:
	disk_put_part(bdev->bd_part);
	bdev->bd_disk = NULL;
	bdev->bd_part = NULL;
	bdev->bd_queue = NULL;
	if (bdev != bdev->bd_contains)
		__blkdev_put(bdev->bd_contains, mode, 1);
	bdev->bd_contains = NULL;
 out_unlock_bdev:
	mutex_unlock(&bdev->bd_mutex);
	disk_unblock_events(disk);
	put_disk(disk);
	module_put(owner);
 out:
	bdput(bdev);

	return ret;
}

Contributors
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tejun heo
tejun heo
166
21.90%
7
12.73%
peter zijlstra
peter zijlstra
156
20.58%
3
5.45%
jun'ichi nomura
jun'ichi nomura
131
17.28%
5
9.09%
al viro
al viro
85
11.21%
12
21.82%
neil brown
neil brown
59
7.78%
3
5.45%
dan williams
dan williams
41
5.41%
2
3.64%
andrew morton
andrew morton
24
3.17%
6
10.91%
andi kleen
andi kleen
20
2.64%
1
1.82%
pavel emelianov
pavel emelianov
17
2.24%
1
1.82%
jeff moyer
jeff moyer
13
1.72%
1
1.82%
matthew wilcox
matthew wilcox
10
1.32%
1
1.82%
ingo molnar
ingo molnar
9
1.19%
1
1.82%
linus torvalds
linus torvalds
6
0.79%
4
7.27%
johannes weiner
johannes weiner
5
0.66%
1
1.82%
arnaldo carvalho de melo
arnaldo carvalho de melo
3
0.40%
1
1.82%
andrew patterson
andrew patterson
3
0.40%
1
1.82%
chris wright
chris wright
3
0.40%
1
1.82%
dave chinner
dave chinner
2
0.26%
1
1.82%
dan carpenter
dan carpenter
2
0.26%
1
1.82%
toshi kani
toshi kani
2
0.26%
1
1.82%
arnd bergmann
arnd bergmann
1
0.13%
1
1.82%
Total
758
100.00%
55
100.00%

/**
 * blkdev_get - open a block device
 * @bdev: block_device to open
 * @mode: FMODE_* mask
 * @holder: exclusive holder identifier
 *
 * Open @bdev with @mode.  If @mode includes %FMODE_EXCL, @bdev is
 * open with exclusive access.  Specifying %FMODE_EXCL with %NULL
 * @holder is invalid.  Exclusive opens may nest for the same @holder.
 *
 * On success, the reference count of @bdev is unchanged.  On failure,
 * @bdev is put.
 *
 * CONTEXT:
 * Might sleep.
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */


int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
{
	struct block_device *whole = NULL;
	int res;

	WARN_ON_ONCE((mode & FMODE_EXCL) && !holder);

	if ((mode & FMODE_EXCL) && holder) {
		whole = bd_start_claiming(bdev, holder);
		if (IS_ERR(whole)) {
			bdput(bdev);
			return PTR_ERR(whole);
		}
	}

	res = __blkdev_get(bdev, mode, 0);

	if (whole) {
		struct gendisk *disk = whole->bd_disk;

		/* finish claiming */
		mutex_lock(&bdev->bd_mutex);
		spin_lock(&bdev_lock);

		if (!res) {
			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;
		}

		/* tell others that we're done */
		BUG_ON(whole->bd_claiming != holder);
		whole->bd_claiming = NULL;
		wake_up_bit(&whole->bd_claiming, 0);

		spin_unlock(&bdev_lock);

		/*
                 * 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 (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder &&
		    (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) {
			bdev->bd_write_holder = true;
			disk_block_events(disk);
		}

		mutex_unlock(&bdev->bd_mutex);
		bdput(whole);
	}

	return res;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
158
63.20%
7
31.82%
peter zijlstra
peter zijlstra
32
12.80%
1
4.55%
al viro
al viro
18
7.20%
7
31.82%
neil brown
neil brown
17
6.80%
1
4.55%
linus torvalds
linus torvalds
11
4.40%
3
13.64%
dave chinner
dave chinner
5
2.00%
1
4.55%
andrew morton
andrew morton
5
2.00%
1
4.55%
pre-git
pre-git
4
1.60%
1
4.55%
Total
250
100.00%
22
100.00%


EXPORT_SYMBOL(blkdev_get);

/**
 * 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 blockdevice described by the device file at @path.  @mode
 * and @holder are identical to blkdev_get().
 *
 * On success, the returned block_device has reference count of one.
 *
 * CONTEXT:
 * Might sleep.
 *
 * RETURNS:
 * Pointer to 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;
	int err;

	bdev = lookup_bdev(path);
	if (IS_ERR(bdev))
		return bdev;

	err = blkdev_get(bdev, mode, holder);
	if (err)
		return ERR_PTR(err);

	if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) {
		blkdev_put(bdev, mode);
		return ERR_PTR(-EACCES);
	}

	return bdev;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
61
62.89%
1
33.33%
chuck ebbert
chuck ebbert
29
29.90%
1
33.33%
peter zijlstra
peter zijlstra
7
7.22%
1
33.33%
Total
97
100.00%
3
100.00%


EXPORT_SYMBOL(blkdev_get_by_path);

/**
 * 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 blockdevice described by device number @dev.  @mode and
 * @holder are identical to blkdev_get().
 *
 * Use it 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.  _Never_ to be used for internal purposes.  If you
 * ever need it - reconsider your API.
 *
 * On success, the returned block_device has reference count of one.
 *
 * CONTEXT:
 * Might sleep.
 *
 * RETURNS:
 * Pointer to block_device on success, ERR_PTR(-errno) on failure.
 */


struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
{
	struct block_device *bdev;
	int err;

	bdev = bdget(dev);
	if (!bdev)
		return ERR_PTR(-ENOMEM);

	err = blkdev_get(bdev, mode, holder);
	if (err)
		return ERR_PTR(err);

	return bdev;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
51
75.00%
1
25.00%
neil brown
neil brown
13
19.12%
1
25.00%
peter zijlstra
peter zijlstra
3
4.41%
1
25.00%
al viro
al viro
1
1.47%
1
25.00%
Total
68
100.00%
4
100.00%


EXPORT_SYMBOL(blkdev_get_by_dev);



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;

	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 = bd_acquire(inode);
	if (bdev == NULL)
		return -ENOMEM;

	filp->f_mapping = bdev->bd_inode->i_mapping;

	return blkdev_get(bdev, filp->f_mode, filp);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
al viro
al viro
61
53.98%
2
33.33%
peter zijlstra
peter zijlstra
34
30.09%
1
16.67%
pavel emelianov
pavel emelianov
10
8.85%
1
16.67%
ingo molnar
ingo molnar
7
6.19%
1
16.67%
tejun heo
tejun heo
1
0.88%
1
16.67%
Total
113
100.00%
6
100.00%



static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
{
	struct gendisk *disk = bdev->bd_disk;
	struct block_device *victim = NULL;

	mutex_lock_nested(&bdev->bd_mutex, for_part);
	if (for_part)
		bdev->bd_part_count--;

	if (!--bdev->bd_openers) {
		WARN_ON_ONCE(bdev->bd_holders);
		sync_blockdev(bdev);
		kill_bdev(bdev);

		bdev_write_inode(bdev);
		/*
                 * Detaching bdev inode from its wb in __destroy_inode()
                 * is too late: the queue which embeds its bdi (along with
                 * root wb) can be gone as soon as we put_disk() below.
                 */
		inode_detach_wb(bdev->bd_inode);
	}
	if (bdev->bd_contains == bdev) {
		if (disk->fops->release)
			disk->fops->release(disk, mode);
	}
	if (!bdev->bd_openers) {
		struct module *owner = disk->fops->owner;

		disk_put_part(bdev->bd_part);
		bdev->bd_part = NULL;
		bdev->bd_disk = NULL;
		if (bdev != bdev->bd_contains)
			victim = bdev->bd_contains;
		bdev->bd_contains = NULL;

		put_disk(disk);
		module_put(owner);
	}
	mutex_unlock(&bdev->bd_mutex);
	bdput(bdev);
	if (victim)
		__blkdev_put(victim, mode, 1);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
peter zijlstra
peter zijlstra
140
64.81%
1
9.09%
neil brown
neil brown
37
17.13%
2
18.18%
tejun heo
tejun heo
18
8.33%
3
27.27%
al viro
al viro
8
3.70%
3
27.27%
ilya dryomov
ilya dryomov
8
3.70%
1
9.09%
christoph hellwig
christoph hellwig
5
2.31%
1
9.09%
Total
216
100.00%
11
100.00%



void blkdev_put(struct block_device *bdev, fmode_t mode)
{
	mutex_lock(&bdev->bd_mutex);

	if (mode & FMODE_EXCL) {
		bool bdev_free;

		/*
                 * Release a claim on the device.  The holder fields
                 * are protected with bdev_lock.  bd_mutex is to
                 * synchronize disk_holder unlinking.
                 */
		spin_lock(&bdev_lock);

		WARN_ON_ONCE(--bdev->bd_holders < 0);
		WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0);

		/* bd_contains might point to self, check in a separate step */
		if ((bdev_free = !bdev->bd_holders))
			bdev->bd_holder = NULL;
		if (!bdev->bd_contains->bd_holders)
			bdev->bd_contains->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(bdev->bd_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(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE);

	mutex_unlock(&bdev->bd_mutex);

	__blkdev_put(bdev, mode, 0);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
120
78.43%
5
55.56%
neil brown
neil brown
15
9.80%
1
11.11%
peter zijlstra
peter zijlstra
11
7.19%
1
11.11%
al viro
al viro
7
4.58%
2
22.22%
Total
153
100.00%
9
100.00%


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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
19
46.34%
1
20.00%
andrew morton
andrew morton
12
29.27%
1
20.00%
al viro
al viro
7
17.07%
2
40.00%
dan williams
dan williams
3
7.32%
1
20.00%
Total
41
100.00%
5
100.00%



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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
al viro
al viro
30
43.48%
1
20.00%
andrew morton
andrew morton
27
39.13%
1
20.00%
christoph hellwig
christoph hellwig
8
11.59%
1
20.00%
dan williams
dan williams
3
4.35%
1
20.00%
arnd bergmann
arnd bergmann
1
1.45%
1
20.00%
Total
69
100.00%
5
100.00%

/*
 * 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.
 */


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;
	ssize_t ret;

	if (bdev_read_only(I_BDEV(bd_inode)))
		return -EPERM;

	if (!iov_iter_count(from))
		return 0;

	if (iocb->ki_pos >= size)
		return -ENOSPC;

	iov_iter_truncate(from, size - iocb->ki_pos);

	blk_start_plug(&plug);
	ret = __generic_file_write_iter(iocb, from);
	if (ret > 0)
		ret = generic_write_sync(iocb, ret);
	blk_finish_plug(&plug);
	return ret;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
al viro
al viro
68
50.00%
3
37.50%
christoph hellwig
christoph hellwig
49
36.03%
3
37.50%
ma jianpeng
ma jianpeng
16
11.76%
1
12.50%
dan williams
dan williams
3
2.21%
1
12.50%
Total
136
100.00%
8
100.00%


EXPORT_SYMBOL_GPL(blkdev_write_iter);



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;

	if (pos >= size)
		return 0;

	size -= pos;
	iov_iter_truncate(to, size);
	return generic_file_read_iter(iocb, to);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
linus torvalds
linus torvalds
60
77.92%
1
25.00%
al viro
al viro
14
18.18%
2
50.00%
dan williams
dan williams
3
3.90%
1
25.00%
Total
77
100.00%
4
100.00%


EXPORT_SYMBOL_GPL(blkdev_read_iter);

/*
 * Try to release a page associated with block device when the system
 * is under memory pressure.
 */


static int blkdev_releasepage(struct page *page, gfp_t wait)
{
	struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super;

	if (super && super->s_op->bdev_try_to_free_page)
		return super->s_op->bdev_try_to_free_page(super, page, wait);

	return try_to_free_buffers(page);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
theodore tso
theodore tso
62
100.00%
1
100.00%
Total
62
100.00%
1
100.00%



static int blkdev_writepages(struct address_space *mapping,
			     struct writeback_control *wbc)
{
	if (dax_mapping(mapping)) {
		struct block_device *bdev = I_BDEV(mapping->host);

		return dax_writeback_mapping_range(mapping, bdev, wbc);
	}
	return generic_writepages(mapping, wbc);
}

Contributors
Person
Tokens
Prop
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CommitProp
ross zwisler
ross zwisler
55
100.00%
1
100.00%
Total
55
100.00%
1
100.00%


static const struct address_space_operations def_blk_aops = {
	.readpage	= blkdev_readpage,
	.readpages	= blkdev_readpages,
	.writepage	= blkdev_writepage,
	.write_begin	= blkdev_write_begin,
	.write_end	= blkdev_write_end,
	.writepages	= blkdev_writepages,
	.releasepage	= blkdev_releasepage,
	.direct_IO	= blkdev_direct_IO,
	.is_dirty_writeback = buffer_check_dirty_writeback,
};


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,
	.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,
};



int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg)
{
	int res;
	mm_segment_t old_fs = get_fs();
	set_fs(KERNEL_DS);
	res = blkdev_ioctl(bdev, 0, cmd, arg);
	set_fs(old_fs);
	return res;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
al viro
al viro
52
100.00%
2
100.00%
Total
52
100.00%
2
100.00%


EXPORT_SYMBOL(ioctl_by_bdev);

/**
 * lookup_bdev  - lookup a struct block_device by name
 * @pathname:   special file representing the block device
 *
 * Get a reference to the blockdevice at @pathname in the current
 * namespace if possible and return it.  Return ERR_PTR(error)
 * otherwise.
 */


struct block_device *lookup_bdev(const char *pathname)
{
	struct block_device *bdev;
	struct inode *inode;
	struct path path;
	int error;

	if (!pathname || !*pathname)
		return ERR_PTR(-EINVAL);

	error = kern_path(pathname, LOOKUP_FOLLOW, &path);
	if (error)
		return ERR_PTR(error);

	inode = d_backing_inode(path.dentry);
	error = -ENOTBLK;
	if (!S_ISBLK(inode->i_mode))
		goto fail;
	error = -EACCES;
	if (path.mnt->mnt_flags & MNT_NODEV)
		goto fail;
	error = -ENOMEM;
	bdev = bd_acquire(inode);
	if (!bdev)
		goto fail;
out:
	path_put(&path);
	return bdev;
fail:
	bdev = ERR_PTR(error);
	goto out;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
christoph hellwig
christoph hellwig
131
84.52%
2
28.57%
al viro
al viro
8
5.16%
1
14.29%
andrew morton
andrew morton
7
4.52%
1
14.29%
jan blunck
jan blunck
6
3.87%
2
28.57%
david howells
david howells
3
1.94%
1
14.29%
Total
155
100.00%
7
100.00%


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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
david howells
david howells
57
91.94%
1
50.00%
neil brown
neil brown
5
8.06%
1
50.00%
Total
62
100.00%
2
100.00%


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;

		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;

		func(I_BDEV(inode), arg);

		spin_lock(&blockdev_superblock->s_inode_list_lock);
	}
	spin_unlock(&blockdev_superblock->s_inode_list_lock);
	iput(old_inode);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
jan kara
jan kara
148
91.93%
1
50.00%
dave chinner
dave chinner
13
8.07%
1
50.00%
Total
161
100.00%
2
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
tejun heo
tejun heo
1291
17.58%
28
9.76%
al viro
al viro
1059
14.42%
48
16.72%
linus torvalds
linus torvalds
634
8.63%
20
6.97%
nick piggin
nick piggin
454
6.18%
5
1.74%
peter zijlstra
peter zijlstra
415
5.65%
5
1.74%
andrew morton
andrew morton
414
5.64%
32
11.15%
matthew wilcox
matthew wilcox
346
4.71%
5
1.74%
jun'ichi nomura
jun'ichi nomura
318
4.33%
5
1.74%
christoph hellwig
christoph hellwig
301
4.10%
18
6.27%
toshi kani
toshi kani
289
3.94%
3
1.05%
pre-git
pre-git
241
3.28%
15
5.23%
jan kara
jan kara
196
2.67%
5
1.74%
dan williams
dan williams
185
2.52%
8
2.79%
neil brown
neil brown
157
2.14%
4
1.39%
andrew patterson
andrew patterson
152
2.07%
4
1.39%
david howells
david howells
71
0.97%
4
1.39%
theodore tso
theodore tso
68
0.93%
1
0.35%
ross zwisler
ross zwisler
57
0.78%
2
0.70%
dave chinner
dave chinner
56
0.76%
3
1.05%
vivek goyal
vivek goyal
42
0.57%
1
0.35%
arnaldo carvalho de melo
arnaldo carvalho de melo
41
0.56%
1
0.35%
akinobu mita
akinobu mita
41
0.56%
1
0.35%
benjamin marzinski
benjamin marzinski
40
0.54%
1
0.35%
hirofumi ogawa
hirofumi ogawa
32
0.44%
1
0.35%
andi kleen
andi kleen
30
0.41%
2
0.70%
pavel emelianov
pavel emelianov
30
0.41%
2
0.70%
chuck ebbert
chuck ebbert
29
0.39%
1
0.35%
shaohua li
shaohua li
22
0.30%
1
0.35%
alan jenkins
alan jenkins
22
0.30%
1
0.35%
rafael j. wysocki
rafael j. wysocki
20
0.27%
1
0.35%
ingo molnar
ingo molnar
16
0.22%
1
0.35%
dmitriy monakhov
dmitriy monakhov
16
0.22%
2
0.70%
anton blanchard
anton blanchard
16
0.22%
2
0.70%
ma jianpeng
ma jianpeng
16
0.22%
1
0.35%
guo chao
guo chao
16
0.22%
1
0.35%
josef bacik
josef bacik
14
0.19%
2
0.70%
jeff moyer
jeff moyer
13
0.18%
1
0.35%
ilya dryomov
ilya dryomov
11
0.15%
2
0.70%
cheng renquan
cheng renquan
11
0.15%
1
0.35%
johannes weiner
johannes weiner
11
0.15%
2
0.70%
vishal verma
vishal verma
10
0.14%
1
0.35%
takashi sato
takashi sato
9
0.12%
1
0.35%
martin k. petersen
martin k. petersen
8
0.11%
2
0.70%
vignesh babu
vignesh babu
7
0.10%
1
0.35%
kenneth w. chen
kenneth w. chen
7
0.10%
1
0.35%
mika kukkonen
mika kukkonen
7
0.10%
1
0.35%
adrian bunk
adrian bunk
7
0.10%
1
0.35%
jens axboe
jens axboe
7
0.10%
2
0.70%
matthias kaehlcke
matthias kaehlcke
6
0.08%
1
0.35%
lachlan mcilroy
lachlan mcilroy
6
0.08%
1
0.35%
christoph lameter
christoph lameter
6
0.08%
3
1.05%
jan blunck
jan blunck
6
0.08%
2
0.70%
mitsunari shigeo
mitsunari shigeo
6
0.08%
1
0.35%
mel gorman
mel gorman
5
0.07%
1
0.35%
anatol pomozov
anatol pomozov
5
0.07%
1
0.35%
thomas gleixner
thomas gleixner
5
0.07%
1
0.35%
david jeffery
david jeffery
5
0.07%
1
0.35%
coywolf qi hunt
coywolf qi hunt
4
0.05%
1
0.35%
randy dunlap
randy dunlap
4
0.05%
3
1.05%
muthu kumar
muthu kumar
4
0.05%
1
0.35%
paul jackson
paul jackson
4
0.05%
2
0.70%
chris wright
chris wright
3
0.04%
1
0.35%
arnd bergmann
arnd bergmann
3
0.04%
2
0.70%
arjan van de ven
arjan van de ven
3
0.04%
2
0.70%
vladimir davydov
vladimir davydov
2
0.03%
1
0.35%
dan carpenter
dan carpenter
2
0.03%
1
0.35%
chuck lever
chuck lever
2
0.03%
1
0.35%
kirill a. shutemov
kirill a. shutemov
2
0.03%
1
0.35%
lucas de marchi
lucas de marchi
1
0.01%
1
0.35%
josef 'jeff' sipek
josef 'jeff' sipek
1
0.01%
1
0.35%
sergey senozhatsky
sergey senozhatsky
1
0.01%
1
0.35%
dan magenheimer
dan magenheimer
1
0.01%
1
0.35%
eric dumazet
eric dumazet
1
0.01%
1
0.35%
alexey dobriyan
alexey dobriyan
1
0.01%
1
0.35%
Total
7344
100.00%
287
100.00%
  
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