Release 4.14 drivers/block/brd.c

/*
 * Ram backed block device driver.
 *
 * Copyright (C) 2007 Nick Piggin
 * Copyright (C) 2007 Novell Inc.
 *
 * Parts derived from drivers/block/rd.c, and drivers/block/loop.c, copyright
 * of their respective owners.
 */

#include <linux/init.h>
#include <linux/initrd.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/major.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/highmem.h>
#include <linux/mutex.h>
#include <linux/radix-tree.h>
#include <linux/fs.h>
#include <linux/slab.h>
#ifdef CONFIG_BLK_DEV_RAM_DAX
#include <linux/pfn_t.h>
#include <linux/dax.h>
#include <linux/uio.h>
#endif

#include <linux/uaccess.h>


#define SECTOR_SHIFT		9

#define PAGE_SECTORS_SHIFT	(PAGE_SHIFT - SECTOR_SHIFT)

#define PAGE_SECTORS		(1 << PAGE_SECTORS_SHIFT)

/*
 * Each block ramdisk device has a radix_tree brd_pages of pages that stores
 * the pages containing the block device's contents. A brd page's ->index is
 * its offset in PAGE_SIZE units. This is similar to, but in no way connected
 * with, the kernel's pagecache or buffer cache (which sit above our block
 * device).
 */

struct brd_device {
	
int		brd_number;

	
struct request_queue	*brd_queue;
	
struct gendisk		*brd_disk;
#ifdef CONFIG_BLK_DEV_RAM_DAX
	
struct dax_device	*dax_dev;
#endif
	
struct list_head	brd_list;

	/*
         * Backing store of pages and lock to protect it. This is the contents
         * of the block device.
         */
	
spinlock_t		brd_lock;
	
struct radix_tree_root	brd_pages;
};

/*
 * Look up and return a brd's page for a given sector.
 */
static DEFINE_MUTEX(brd_mutex);


static struct page *brd_lookup_page(struct brd_device *brd, sector_t sector)
{
	pgoff_t idx;
	struct page *page;

	/*
         * The page lifetime is protected by the fact that we have opened the
         * device node -- brd pages will never be deleted under us, so we
         * don't need any further locking or refcounting.
         *
         * This is strictly true for the radix-tree nodes as well (ie. we
         * don't actually need the rcu_read_lock()), however that is not a
         * documented feature of the radix-tree API so it is better to be
         * safe here (we don't have total exclusion from radix tree updates
         * here, only deletes).
         */
	rcu_read_lock();
	idx = sector >> PAGE_SECTORS_SHIFT; /* sector to page index */
	page = radix_tree_lookup(&brd->brd_pages, idx);
	rcu_read_unlock();

	BUG_ON(page && page->index != idx);

	return page;
}

Contributors
Person
Tokens
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CommitProp
Nicholas Piggin
41
64.06%
1
20.00%
Linus Torvalds
12
18.75%
1
20.00%
Andrew Morton
11
17.19%
3
60.00%
Total
64
100.00%
5
100.00%

/*
 * Look up and return a brd's page for a given sector.
 * If one does not exist, allocate an empty page, and insert that. Then
 * return it.
 */


static struct page *brd_insert_page(struct brd_device *brd, sector_t sector)
{
	pgoff_t idx;
	struct page *page;
	gfp_t gfp_flags;

	page = brd_lookup_page(brd, sector);
	if (page)
		return page;

	/*
         * Must use NOIO because we don't want to recurse back into the
         * block or filesystem layers from page reclaim.
         *
         * Cannot support DAX and highmem, because our ->direct_access
         * routine for DAX must return memory that is always addressable.
         * If DAX was reworked to use pfns and kmap throughout, this
         * restriction might be able to be lifted.
         */
	gfp_flags = GFP_NOIO | __GFP_ZERO;
#ifndef CONFIG_BLK_DEV_RAM_DAX
	gfp_flags |= __GFP_HIGHMEM;
#endif
	page = alloc_page(gfp_flags);
	if (!page)
		return NULL;

	if (radix_tree_preload(GFP_NOIO)) {
		__free_page(page);
		return NULL;
	}

	spin_lock(&brd->brd_lock);
	idx = sector >> PAGE_SECTORS_SHIFT;
	page->index = idx;
	if (radix_tree_insert(&brd->brd_pages, idx, page)) {
		__free_page(page);
		page = radix_tree_lookup(&brd->brd_pages, idx);
		BUG_ON(!page);
		BUG_ON(page->index != idx);
	}
	spin_unlock(&brd->brd_lock);

	radix_tree_preload_end();

	return page;
}

Contributors
Person
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CommitProp
Nicholas Piggin
110
63.58%
2
25.00%
Andrew Morton
37
21.39%
2
25.00%
Linus Torvalds
17
9.83%
1
12.50%
Brian Behlendorf
6
3.47%
1
12.50%
Matthew Wilcox
2
1.16%
1
12.50%
Petr Tesarik
1
0.58%
1
12.50%
Total
173
100.00%
8
100.00%

/*
 * Free all backing store pages and radix tree. This must only be called when
 * there are no other users of the device.
 */

#define FREE_BATCH 16


static void brd_free_pages(struct brd_device *brd)
{
	unsigned long pos = 0;
	struct page *pages[FREE_BATCH];
	int nr_pages;

	do {
		int i;

		nr_pages = radix_tree_gang_lookup(&brd->brd_pages,
				(void **)pages, pos, FREE_BATCH);

		for (i = 0; i < nr_pages; i++) {
			void *ret;

			BUG_ON(pages[i]->index < pos);
			pos = pages[i]->index;
			ret = radix_tree_delete(&brd->brd_pages, pos);
			BUG_ON(!ret || ret != pages[i]);
			__free_page(pages[i]);
		}

		pos++;

		/*
                 * This assumes radix_tree_gang_lookup always returns as
                 * many pages as possible. If the radix-tree code changes,
                 * so will this have to.
                 */
	} while (nr_pages == FREE_BATCH);
}

Contributors
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CommitProp
Nicholas Piggin
130
93.53%
1
50.00%
Andrew Morton
9
6.47%
1
50.00%
Total
139
100.00%
2
100.00%

/*
 * copy_to_brd_setup must be called before copy_to_brd. It may sleep.
 */


static int copy_to_brd_setup(struct brd_device *brd, sector_t sector, size_t n)
{
	unsigned int offset = (sector & (PAGE_SECTORS-1)) << SECTOR_SHIFT;
	size_t copy;

	copy = min_t(size_t, n, PAGE_SIZE - offset);
	if (!brd_insert_page(brd, sector))
		return -ENOSPC;
	if (copy < n) {
		sector += copy >> SECTOR_SHIFT;
		if (!brd_insert_page(brd, sector))
			return -ENOSPC;
	}
	return 0;
}

Contributors
Person
Tokens
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CommitProp
Nicholas Piggin
73
77.66%
1
20.00%
Andrew Morton
15
15.96%
2
40.00%
Linus Torvalds
4
4.26%
1
20.00%
Matthew Wilcox
2
2.13%
1
20.00%
Total
94
100.00%
5
100.00%

/*
 * Copy n bytes from src to the brd starting at sector. Does not sleep.
 */


static void copy_to_brd(struct brd_device *brd, const void *src,
			sector_t sector, size_t n)
{
	struct page *page;
	void *dst;
	unsigned int offset = (sector & (PAGE_SECTORS-1)) << SECTOR_SHIFT;
	size_t copy;

	copy = min_t(size_t, n, PAGE_SIZE - offset);
	page = brd_lookup_page(brd, sector);
	BUG_ON(!page);

	dst = kmap_atomic(page);
	memcpy(dst + offset, src, copy);
	kunmap_atomic(dst);

	if (copy < n) {
		src += copy;
		sector += copy >> SECTOR_SHIFT;
		copy = n - copy;
		page = brd_lookup_page(brd, sector);
		BUG_ON(!page);

		dst = kmap_atomic(page);
		memcpy(dst, src, copy);
		kunmap_atomic(dst);
	}
}

Contributors
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CommitProp
Nicholas Piggin
84
52.17%
1
10.00%
Linus Torvalds
52
32.30%
3
30.00%
Andrew Morton
11
6.83%
2
20.00%
Al Viro
7
4.35%
1
10.00%
Christian Bornträger
5
3.11%
1
10.00%
Russell King
1
0.62%
1
10.00%
Christoph Hellwig
1
0.62%
1
10.00%
Total
161
100.00%
10
100.00%

/*
 * Copy n bytes to dst from the brd starting at sector. Does not sleep.
 */


static void copy_from_brd(void *dst, struct brd_device *brd,
			sector_t sector, size_t n)
{
	struct page *page;
	void *src;
	unsigned int offset = (sector & (PAGE_SECTORS-1)) << SECTOR_SHIFT;
	size_t copy;

	copy = min_t(size_t, n, PAGE_SIZE - offset);
	page = brd_lookup_page(brd, sector);
	if (page) {
		src = kmap_atomic(page);
		memcpy(dst, src + offset, copy);
		kunmap_atomic(src);
	} else
		memset(dst, 0, copy);

	if (copy < n) {
		dst += copy;
		sector += copy >> SECTOR_SHIFT;
		copy = n - copy;
		page = brd_lookup_page(brd, sector);
		if (page) {
			src = kmap_atomic(page);
			memcpy(dst, src, copy);
			kunmap_atomic(src);
		} else
			memset(dst, 0, copy);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Nicholas Piggin
131
72.78%
1
14.29%
Linus Torvalds
27
15.00%
3
42.86%
Al Viro
13
7.22%
1
14.29%
Linus Torvalds (pre-git)
9
5.00%
2
28.57%
Total
180
100.00%
7
100.00%

/*
 * Process a single bvec of a bio.
 */


static int brd_do_bvec(struct brd_device *brd, struct page *page,
			unsigned int len, unsigned int off, bool is_write,
			sector_t sector)
{
	void *mem;
	int err = 0;

	if (is_write) {
		err = copy_to_brd_setup(brd, sector, len);
		if (err)
			goto out;
	}

	mem = kmap_atomic(page);
	if (!is_write) {
		copy_from_brd(mem + off, brd, sector, len);
		flush_dcache_page(page);
	} else {
		flush_dcache_page(page);
		copy_to_brd(brd, mem + off, sector, len);
	}
	kunmap_atomic(mem);

out:
	return err;
}

Contributors
Person
Tokens
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Commits
CommitProp
Nicholas Piggin
94
74.60%
2
20.00%
Linus Torvalds (pre-git)
18
14.29%
2
20.00%
Linus Torvalds
5
3.97%
2
20.00%
Al Viro
4
3.17%
2
20.00%
Jens Axboe
4
3.17%
1
10.00%
Michael Christie
1
0.79%
1
10.00%
Total
126
100.00%
10
100.00%



static blk_qc_t brd_make_request(struct request_queue *q, struct bio *bio)
{
	struct brd_device *brd = bio->bi_disk->private_data;
	struct bio_vec bvec;
	sector_t sector;
	struct bvec_iter iter;

	sector = bio->bi_iter.bi_sector;
	if (bio_end_sector(bio) > get_capacity(bio->bi_disk))
		goto io_error;

	bio_for_each_segment(bvec, bio, iter) {
		unsigned int len = bvec.bv_len;
		int err;

		err = brd_do_bvec(brd, bvec.bv_page, len, bvec.bv_offset,
					op_is_write(bio_op(bio)), sector);
		if (err)
			goto io_error;
		sector += len >> SECTOR_SHIFT;
	}

	bio_endio(bio);
	return BLK_QC_T_NONE;
io_error:
	bio_io_error(bio);
	return BLK_QC_T_NONE;
}

Contributors
Person
Tokens
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Commits
CommitProp
Nicholas Piggin
98
69.01%
1
11.11%
Christoph Hellwig
18
12.68%
2
22.22%
Kent Overstreet
12
8.45%
3
33.33%
Jens Axboe
10
7.04%
2
22.22%
Michael Christie
4
2.82%
1
11.11%
Total
142
100.00%
9
100.00%



static int brd_rw_page(struct block_device *bdev, sector_t sector,
		       struct page *page, bool is_write)
{
	struct brd_device *brd = bdev->bd_disk->private_data;
	int err;

	if (PageTransHuge(page))
		return -ENOTSUPP;
	err = brd_do_bvec(brd, page, PAGE_SIZE, 0, is_write, sector);
	page_endio(page, is_write, err);
	return err;
}

Contributors
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CommitProp
Matthew Wilcox
56
73.68%
1
25.00%
Huang Ying
15
19.74%
1
25.00%
Jens Axboe
4
5.26%
1
25.00%
Kirill A. Shutemov
1
1.32%
1
25.00%
Total
76
100.00%
4
100.00%

#ifdef CONFIG_BLK_DEV_RAM_DAX


static long __brd_direct_access(struct brd_device *brd, pgoff_t pgoff,
		long nr_pages, void **kaddr, pfn_t *pfn)
{
	struct page *page;

	if (!brd)
		return -ENODEV;
	page = brd_insert_page(brd, (sector_t)pgoff << PAGE_SECTORS_SHIFT);
	if (!page)
		return -ENOSPC;
	*kaddr = page_address(page);
	*pfn = page_to_pfn_t(page);

	return 1;
}

Contributors
Person
Tokens
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CommitProp
Nicholas Piggin
49
59.76%
1
14.29%
Jared Hulbert
14
17.07%
1
14.29%
Dan J Williams
12
14.63%
2
28.57%
Mikulas Patocka
5
6.10%
1
14.29%
Matthew Wilcox
2
2.44%
2
28.57%
Total
82
100.00%
7
100.00%



static long brd_dax_direct_access(struct dax_device *dax_dev,
		pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn)
{
	struct brd_device *brd = dax_get_private(dax_dev);

	return __brd_direct_access(brd, pgoff, nr_pages, kaddr, pfn);
}

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Dan J Williams
50
100.00%
1
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50
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1
100.00%



static size_t brd_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
		void *addr, size_t bytes, struct iov_iter *i)
{
	return copy_from_iter(addr, bytes, i);
}

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Dan J Williams
36
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1
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36
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1
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static const struct dax_operations brd_dax_ops = {
	.direct_access = brd_dax_direct_access,
	.copy_from_iter = brd_dax_copy_from_iter,
};
#endif


static const struct block_device_operations brd_fops = {
	.owner =		THIS_MODULE,
	.rw_page =		brd_rw_page,
};

/*
 * And now the modules code and kernel interface.
 */

static int rd_nr = CONFIG_BLK_DEV_RAM_COUNT;
module_param(rd_nr, int, S_IRUGO);
MODULE_PARM_DESC(rd_nr, "Maximum number of brd devices");


unsigned long rd_size = CONFIG_BLK_DEV_RAM_SIZE;
module_param(rd_size, ulong, S_IRUGO);
MODULE_PARM_DESC(rd_size, "Size of each RAM disk in kbytes.");


static int max_part = 1;
module_param(max_part, int, S_IRUGO);
MODULE_PARM_DESC(max_part, "Num Minors to reserve between devices");

MODULE_LICENSE("GPL");

MODULE_ALIAS_BLOCKDEV_MAJOR(RAMDISK_MAJOR);
MODULE_ALIAS("rd");

#ifndef MODULE
/* Legacy boot options - nonmodular */


static int __init ramdisk_size(char *str)
{
	rd_size = simple_strtol(str, NULL, 0);
	return 1;
}
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Nicholas Piggin
22
88.00%
1
50.00%
Linus Torvalds
3
12.00%
1
50.00%
Total
25
100.00%
2
100.00%

__setup("ramdisk_size=", ramdisk_size);
#endif

/*
 * The device scheme is derived from loop.c. Keep them in synch where possible
 * (should share code eventually).
 */
static LIST_HEAD(brd_devices);
static DEFINE_MUTEX(brd_devices_mutex);



static struct brd_device *brd_alloc(int i)
{
	struct brd_device *brd;
	struct gendisk *disk;

	brd = kzalloc(sizeof(*brd), GFP_KERNEL);
	if (!brd)
		goto out;
	brd->brd_number		= i;
	spin_lock_init(&brd->brd_lock);
	INIT_RADIX_TREE(&brd->brd_pages, GFP_ATOMIC);

	brd->brd_queue = blk_alloc_queue(GFP_KERNEL);
	if (!brd->brd_queue)
		goto out_free_dev;

	blk_queue_make_request(brd->brd_queue, brd_make_request);
	blk_queue_max_hw_sectors(brd->brd_queue, 1024);

	/* This is so fdisk will align partitions on 4k, because of
         * direct_access API needing 4k alignment, returning a PFN
         * (This is only a problem on very small devices <= 4M,
         *  otherwise fdisk will align on 1M. Regardless this call
         *  is harmless)
         */
	blk_queue_physical_block_size(brd->brd_queue, PAGE_SIZE);
	disk = brd->brd_disk = alloc_disk(max_part);
	if (!disk)
		goto out_free_queue;
	disk->major		= RAMDISK_MAJOR;
	disk->first_minor	= i * max_part;
	disk->fops		= &brd_fops;
	disk->private_data	= brd;
	disk->queue		= brd->brd_queue;
	disk->flags		= GENHD_FL_EXT_DEVT;
	sprintf(disk->disk_name, "ram%d", i);
	set_capacity(disk, rd_size * 2);

#ifdef CONFIG_BLK_DEV_RAM_DAX
	queue_flag_set_unlocked(QUEUE_FLAG_DAX, brd->brd_queue);
	brd->dax_dev = alloc_dax(brd, disk->disk_name, &brd_dax_ops);
	if (!brd->dax_dev)
		goto out_free_inode;
#endif


	return brd;

#ifdef CONFIG_BLK_DEV_RAM_DAX
out_free_inode:
	kill_dax(brd->dax_dev);
	put_dax(brd->dax_dev);
#endif
out_free_queue:
	blk_cleanup_queue(brd->brd_queue);
out_free_dev:
	kfree(brd);
out:
	return NULL;
}

Contributors
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Nicholas Piggin
143
51.44%
1
4.55%
Dan J Williams
53
19.06%
1
4.55%
Andrew Morton
18
6.47%
2
9.09%
Boaz Harrosh
15
5.40%
2
9.09%
Al Viro
12
4.32%
5
22.73%
Linus Torvalds
9
3.24%
3
13.64%
Linus Torvalds (pre-git)
8
2.88%
4
18.18%
Gerald Schaefer
8
2.88%
1
4.55%
Eric W. Biedermann
7
2.52%
1
4.55%
Marcin Krol
4
1.44%
1
4.55%
Martin K. Petersen
1
0.36%
1
4.55%
Total
278
100.00%
22
100.00%



static void brd_free(struct brd_device *brd)
{
	put_disk(brd->brd_disk);
	blk_cleanup_queue(brd->brd_queue);
	brd_free_pages(brd);
	kfree(brd);
}

Contributors
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Nicholas Piggin
32
91.43%
1
50.00%
Linus Torvalds (pre-git)
3
8.57%
1
50.00%
Total
35
100.00%
2
100.00%



static struct brd_device *brd_init_one(int i, bool *new)
{
	struct brd_device *brd;

	*new = false;
	list_for_each_entry(brd, &brd_devices, brd_list) {
		if (brd->brd_number == i)
			goto out;
	}

	brd = brd_alloc(i);
	if (brd) {
		add_disk(brd->brd_disk);
		list_add_tail(&brd->brd_list, &brd_devices);
	}
	*new = true;
out:
	return brd;
}

Contributors
Person
Tokens
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CommitProp
Nicholas Piggin
50
57.47%
1
9.09%
Boaz Harrosh
14
16.09%
1
9.09%
Al Viro
8
9.20%
3
27.27%
Linus Torvalds (pre-git)
6
6.90%
3
27.27%
Linus Torvalds
6
6.90%
2
18.18%
Jeff Garzik
3
3.45%
1
9.09%
Total
87
100.00%
11
100.00%



static void brd_del_one(struct brd_device *brd)
{
	list_del(&brd->brd_list);
#ifdef CONFIG_BLK_DEV_RAM_DAX
	kill_dax(brd->dax_dev);
	put_dax(brd->dax_dev);
#endif
	del_gendisk(brd->brd_disk);
	brd_free(brd);
}

Contributors
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CommitProp
Nicholas Piggin
21
42.00%
1
25.00%
Dan J Williams
19
38.00%
1
25.00%
Peter Zijlstra
6
12.00%
1
25.00%
Linus Torvalds (pre-git)
4
8.00%
1
25.00%
Total
50
100.00%
4
100.00%



static struct kobject *brd_probe(dev_t dev, int *part, void *data)
{
	struct brd_device *brd;
	struct kobject *kobj;
	bool new;

	mutex_lock(&brd_devices_mutex);
	brd = brd_init_one(MINOR(dev) / max_part, &new);
	kobj = brd ? get_disk(brd->brd_disk) : NULL;
	mutex_unlock(&brd_devices_mutex);

	if (new)
		*part = 0;

	return kobj;
}

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CommitProp
Nicholas Piggin
45
53.57%
1
11.11%
Boaz Harrosh
12
14.29%
1
11.11%
Peter Zijlstra
11
13.10%
1
11.11%
Linus Torvalds (pre-git)
11
13.10%
3
33.33%
Namhyung Kim
3
3.57%
1
11.11%
Mikulas Patocka
1
1.19%
1
11.11%
Linus Torvalds
1
1.19%
1
11.11%
Total
84
100.00%
9
100.00%



static int __init brd_init(void)
{
	struct brd_device *brd, *next;
	int i;

	/*
         * brd module now has a feature to instantiate underlying device
         * structure on-demand, provided that there is an access dev node.
         *
         * (1) if rd_nr is specified, create that many upfront. else
         *     it defaults to CONFIG_BLK_DEV_RAM_COUNT
         * (2) User can further extend brd devices by create dev node themselves
         *     and have kernel automatically instantiate actual device
         *     on-demand. Example:
         *              mknod /path/devnod_name b 1 X   # 1 is the rd major
         *              fdisk -l /path/devnod_name
         *      If (X / max_part) was not already created it will be created
         *      dynamically.
         */

	if (register_blkdev(RAMDISK_MAJOR, "ramdisk"))
		return -EIO;

	if (unlikely(!max_part))
		max_part = 1;

	for (i = 0; i < rd_nr; i++) {
		brd = brd_alloc(i);
		if (!brd)
			goto out_free;
		list_add_tail(&brd->brd_list, &brd_devices);
	}

	/* point of no return */

	list_for_each_entry(brd, &brd_devices, brd_list)
		add_disk(brd->brd_disk);

	blk_register_region(MKDEV(RAMDISK_MAJOR, 0), 1UL << MINORBITS,
				  THIS_MODULE, brd_probe, NULL, NULL);

	pr_info("brd: module loaded\n");
	return 0;

out_free:
	list_for_each_entry_safe(brd, next, &brd_devices, brd_list) {
		list_del(&brd->brd_list);
		brd_free(brd);
	}
	unregister_blkdev(RAMDISK_MAJOR, "ramdisk");

	pr_info("brd: module NOT loaded !!!\n");
	return -ENOMEM;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Nicholas Piggin
103
58.52%
1
5.26%
Boaz Harrosh
26
14.77%
1
5.26%
Linus Torvalds (pre-git)
16
9.09%
5
26.32%
Al Viro
11
6.25%
5
26.32%
Peter Zijlstra
7
3.98%
1
5.26%
Linus Torvalds
7
3.98%
1
5.26%
Andrew Morton
4
2.27%
3
15.79%
Akinobu Mita
1
0.57%
1
5.26%
Christoph Hellwig
1
0.57%
1
5.26%
Total
176
100.00%
19
100.00%



static void __exit brd_exit(void)
{
	struct brd_device *brd, *next;

	list_for_each_entry_safe(brd, next, &brd_devices, brd_list)
		brd_del_one(brd);

	blk_unregister_region(MKDEV(RAMDISK_MAJOR, 0), 1UL << MINORBITS);
	unregister_blkdev(RAMDISK_MAJOR, "ramdisk");

	pr_info("brd: module unloaded\n");
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Nicholas Piggin
27
46.55%
1
16.67%
Linus Torvalds
12
20.69%
1
16.67%
Linus Torvalds (pre-git)
11
18.97%
3
50.00%
Boaz Harrosh
8
13.79%
1
16.67%
Total
58
100.00%
6
100.00%


module_init(brd_init);

module_exit(brd_exit);

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Nicholas Piggin
1387
57.82%
4
3.77%
Dan J Williams
212
8.84%
3
2.83%
Linus Torvalds
165
6.88%
9
8.49%
Andrew Morton
118
4.92%
15
14.15%
Linus Torvalds (pre-git)
95
3.96%
17
16.04%
Boaz Harrosh
87
3.63%
2
1.89%
Matthew Wilcox
67
2.79%
4
3.77%
Al Viro
58
2.42%
11
10.38%
Christoph Hellwig
29
1.21%
6
5.66%
Peter Zijlstra
24
1.00%
1
0.94%
Jens Axboe
18
0.75%
2
1.89%
Huang Ying
15
0.63%
1
0.94%
Jared Hulbert
14
0.58%
1
0.94%
Dmitriy Monakhov
14
0.58%
1
0.94%
Kent Overstreet
12
0.50%
3
2.83%
Arnd Bergmann
9
0.38%
2
1.89%
Gerald Schaefer
8
0.33%
1
0.94%
Eric W. Biedermann
7
0.29%
1
0.94%
Mikulas Patocka
6
0.25%
2
1.89%
Brian Behlendorf
6
0.25%
1
0.94%
Stephen Hemminger
6
0.25%
1
0.94%
Namhyung Kim
5
0.21%
2
1.89%
Michael Christie
5
0.21%
1
0.94%
Christian Bornträger
5
0.21%
1
0.94%
Marcin Krol
4
0.17%
1
0.94%
Bart Van Assche
3
0.13%
1
0.94%
Robert P. J. Day
3
0.13%
2
1.89%
Tejun Heo
3
0.13%
1
0.94%
Jeff Garzik
3
0.13%
1
0.94%
Jan Kara
3
0.13%
1
0.94%
Laurent Vivier
2
0.08%
1
0.94%
Russell King
1
0.04%
1
0.94%
Petr Tesarik
1
0.04%
1
0.94%
Akinobu Mita
1
0.04%
1
0.94%
Kirill A. Shutemov
1
0.04%
1
0.94%
Alexey Dobriyan
1
0.04%
1
0.94%
Martin K. Petersen
1
0.04%
1
0.94%
Total
2399
100.00%
106
100.00%
Directory: drivers/block

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