[net-next-2.6.git] / block / blk-lib.c

/*
 * Functions related to generic helpers functions
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/scatterlist.h>

#include "blk.h"

static void blkdev_discard_end_io(struct bio *bio, int err)
{
	if (err) {
		if (err == -EOPNOTSUPP)
			set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
		clear_bit(BIO_UPTODATE, &bio->bi_flags);
	}

	if (bio->bi_private)
		complete(bio->bi_private);

	bio_put(bio);
}

/**
 * blkdev_issue_discard - queue a discard
 * @bdev:	blockdev to issue discard for
 * @sector:	start sector
 * @nr_sects:	number of sectors to discard
 * @gfp_mask:	memory allocation flags (for bio_alloc)
 * @flags:	BLKDEV_IFL_* flags to control behaviour
 *
 * Description:
 *    Issue a discard request for the sectors in question.
 */
int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
{
	DECLARE_COMPLETION_ONSTACK(wait);
	struct request_queue *q = bdev_get_queue(bdev);
	int type = REQ_WRITE | REQ_DISCARD;
	unsigned int max_discard_sectors;
	struct bio *bio;
	int ret = 0;

	if (!q)
		return -ENXIO;

	if (!blk_queue_discard(q))
		return -EOPNOTSUPP;

	/*
	 * Ensure that max_discard_sectors is of the proper
	 * granularity
	 */
	max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
	if (q->limits.discard_granularity) {
		unsigned int disc_sects = q->limits.discard_granularity >> 9;

		max_discard_sectors &= ~(disc_sects - 1);
	}

	if (flags & BLKDEV_DISCARD_SECURE) {
		if (!blk_queue_secdiscard(q))
			return -EOPNOTSUPP;
		type |= REQ_SECURE;
	}

	while (nr_sects && !ret) {
		bio = bio_alloc(gfp_mask, 1);
		if (!bio) {
			ret = -ENOMEM;
			break;
		}

		bio->bi_sector = sector;
		bio->bi_end_io = blkdev_discard_end_io;
		bio->bi_bdev = bdev;
		bio->bi_private = &wait;

		if (nr_sects > max_discard_sectors) {
			bio->bi_size = max_discard_sectors << 9;
			nr_sects -= max_discard_sectors;
			sector += max_discard_sectors;
		} else {
			bio->bi_size = nr_sects << 9;
			nr_sects = 0;
		}

		bio_get(bio);
		submit_bio(type, bio);

		wait_for_completion(&wait);

		if (bio_flagged(bio, BIO_EOPNOTSUPP))
			ret = -EOPNOTSUPP;
		else if (!bio_flagged(bio, BIO_UPTODATE))
			ret = -EIO;
		bio_put(bio);
	}

	return ret;
}
EXPORT_SYMBOL(blkdev_issue_discard);

struct bio_batch
{
	atomic_t 		done;
	unsigned long 		flags;
	struct completion 	*wait;
	bio_end_io_t		*end_io;
};

static void bio_batch_end_io(struct bio *bio, int err)
{
	struct bio_batch *bb = bio->bi_private;

	if (err) {
		if (err == -EOPNOTSUPP)
			set_bit(BIO_EOPNOTSUPP, &bb->flags);
		else
			clear_bit(BIO_UPTODATE, &bb->flags);
	}
	if (bb) {
		if (bb->end_io)
			bb->end_io(bio, err);
		atomic_inc(&bb->done);
		complete(bb->wait);
	}
	bio_put(bio);
}

/**
 * blkdev_issue_zeroout generate number of zero filed write bios
 * @bdev:	blockdev to issue
 * @sector:	start sector
 * @nr_sects:	number of sectors to write
 * @gfp_mask:	memory allocation flags (for bio_alloc)
 *
 * Description:
 *  Generate and issue number of bios with zerofiled pages.
 *  Send barrier at the beginning and at the end if requested. This guarantie
 *  correct request ordering. Empty barrier allow us to avoid post queue flush.
 */

int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
			sector_t nr_sects, gfp_t gfp_mask)
{
	int ret;
	struct bio *bio;
	struct bio_batch bb;
	unsigned int sz, issued = 0;
	DECLARE_COMPLETION_ONSTACK(wait);

	atomic_set(&bb.done, 0);
	bb.flags = 1 << BIO_UPTODATE;
	bb.wait = &wait;
	bb.end_io = NULL;

submit:
	ret = 0;
	while (nr_sects != 0) {
		bio = bio_alloc(gfp_mask,
				min(nr_sects, (sector_t)BIO_MAX_PAGES));
		if (!bio) {
			ret = -ENOMEM;
			break;
		}

		bio->bi_sector = sector;
		bio->bi_bdev   = bdev;
		bio->bi_end_io = bio_batch_end_io;
		bio->bi_private = &bb;

		while (nr_sects != 0) {
			sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
			if (sz == 0)
				/* bio has maximum size possible */
				break;
			ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
			nr_sects -= ret >> 9;
			sector += ret >> 9;
			if (ret < (sz << 9))
				break;
		}
		ret = 0;
		issued++;
		submit_bio(WRITE, bio);
	}

	/* Wait for bios in-flight */
	while (issued != atomic_read(&bb.done))
		wait_for_completion(&wait);

	if (!test_bit(BIO_UPTODATE, &bb.flags))
		/* One of bios in the batch was completed with error.*/
		ret = -EIO;

	if (ret)
		goto out;

	if (test_bit(BIO_EOPNOTSUPP, &bb.flags)) {
		ret = -EOPNOTSUPP;
		goto out;
	}
	if (nr_sects != 0)
		goto submit;
out:
	return ret;
}
EXPORT_SYMBOL(blkdev_issue_zeroout);
Commit	Line	Data
f31e7e40 DM	1	/*
	2	* Functions related to generic helpers functions
	3	*/
	4	#include <linux/kernel.h>
	5	#include <linux/module.h>
	6	#include <linux/bio.h>
	7	#include <linux/blkdev.h>
	8	#include <linux/scatterlist.h>
	9
	10	#include "blk.h"
	11
	12	static void blkdev_discard_end_io(struct bio *bio, int err)
	13	{
	14	if (err) {
	15	if (err == -EOPNOTSUPP)
	16	set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
	17	clear_bit(BIO_UPTODATE, &bio->bi_flags);
	18	}
	19
	20	if (bio->bi_private)
	21	complete(bio->bi_private);
f31e7e40 DM	22
	23	bio_put(bio);
	24	}
	25
	26	/**
	27	* blkdev_issue_discard - queue a discard
	28	* @bdev: blockdev to issue discard for
	29	* @sector: start sector
	30	* @nr_sects: number of sectors to discard
	31	* @gfp_mask: memory allocation flags (for bio_alloc)
	32	* @flags: BLKDEV_IFL_* flags to control behaviour
	33	*
	34	* Description:
	35	* Issue a discard request for the sectors in question.
	36	*/
	37	int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
	38	sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
	39	{
	40	DECLARE_COMPLETION_ONSTACK(wait);
	41	struct request_queue *q = bdev_get_queue(bdev);
8c555367	42	int type = REQ_WRITE \| REQ_DISCARD;
10d1f9e2	43	unsigned int max_discard_sectors;
f31e7e40	44	struct bio *bio;
f31e7e40 DM	45	int ret = 0;
	46
	47	if (!q)
	48	return -ENXIO;
	49
	50	if (!blk_queue_discard(q))
	51	return -EOPNOTSUPP;
	52
10d1f9e2 JA	53	/*
	54	* Ensure that max_discard_sectors is of the proper
	55	* granularity
	56	*/
	57	max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
	58	if (q->limits.discard_granularity) {
	59	unsigned int disc_sects = q->limits.discard_granularity >> 9;
	60
	61	max_discard_sectors &= ~(disc_sects - 1);
	62	}
f31e7e40	63
dd3932ed	64	if (flags & BLKDEV_DISCARD_SECURE) {
8d57a98c AH	65	if (!blk_queue_secdiscard(q))
8d57a98c AH	66	return -EOPNOTSUPP;
8c555367	67	type \|= REQ_SECURE;
8d57a98c AH	68	}
8d57a98c AH	69
10d1f9e2	70	while (nr_sects && !ret) {
f31e7e40	71	bio = bio_alloc(gfp_mask, 1);
66ac0280 CH	72	if (!bio) {
	73	ret = -ENOMEM;
	74	break;
	75	}
	76
f31e7e40 DM	77	bio->bi_sector = sector;
	78	bio->bi_end_io = blkdev_discard_end_io;
	79	bio->bi_bdev = bdev;
dd3932ed	80	bio->bi_private = &wait;
f31e7e40	81
f31e7e40 DM	82	if (nr_sects > max_discard_sectors) {
	83	bio->bi_size = max_discard_sectors << 9;
	84	nr_sects -= max_discard_sectors;
	85	sector += max_discard_sectors;
	86	} else {
	87	bio->bi_size = nr_sects << 9;
	88	nr_sects = 0;
	89	}
	90
	91	bio_get(bio);
	92	submit_bio(type, bio);
	93
dd3932ed	94	wait_for_completion(&wait);
f31e7e40 DM	95
	96	if (bio_flagged(bio, BIO_EOPNOTSUPP))
	97	ret = -EOPNOTSUPP;
	98	else if (!bio_flagged(bio, BIO_UPTODATE))
	99	ret = -EIO;
	100	bio_put(bio);
	101	}
66ac0280	102
f31e7e40	103	return ret;
f31e7e40 DM	104	}
f31e7e40 DM	105	EXPORT_SYMBOL(blkdev_issue_discard);
3f14d792 DM	106
	107	struct bio_batch
	108	{
	109	atomic_t done;
	110	unsigned long flags;
	111	struct completion *wait;
	112	bio_end_io_t *end_io;
	113	};
	114
	115	static void bio_batch_end_io(struct bio *bio, int err)
	116	{
	117	struct bio_batch *bb = bio->bi_private;
0341aafb	118
3f14d792 DM	119	if (err) {
	120	if (err == -EOPNOTSUPP)
	121	set_bit(BIO_EOPNOTSUPP, &bb->flags);
	122	else
	123	clear_bit(BIO_UPTODATE, &bb->flags);
	124	}
	125	if (bb) {
	126	if (bb->end_io)
	127	bb->end_io(bio, err);
	128	atomic_inc(&bb->done);
	129	complete(bb->wait);
	130	}
	131	bio_put(bio);
	132	}
	133
	134	/**
	135	* blkdev_issue_zeroout generate number of zero filed write bios
	136	* @bdev: blockdev to issue
	137	* @sector: start sector
	138	* @nr_sects: number of sectors to write
	139	* @gfp_mask: memory allocation flags (for bio_alloc)
3f14d792 DM	140	*
	141	* Description:
	142	* Generate and issue number of bios with zerofiled pages.
	143	* Send barrier at the beginning and at the end if requested. This guarantie
	144	* correct request ordering. Empty barrier allow us to avoid post queue flush.
	145	*/
	146
	147	int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
dd3932ed	148	sector_t nr_sects, gfp_t gfp_mask)
3f14d792	149	{
18edc8ea	150	int ret;
3f14d792 DM	151	struct bio *bio;
	152	struct bio_batch bb;
	153	unsigned int sz, issued = 0;
	154	DECLARE_COMPLETION_ONSTACK(wait);
	155
	156	atomic_set(&bb.done, 0);
	157	bb.flags = 1 << BIO_UPTODATE;
	158	bb.wait = &wait;
	159	bb.end_io = NULL;
	160
3f14d792	161	submit:
18edc8ea	162	ret = 0;
3f14d792 DM	163	while (nr_sects != 0) {
	164	bio = bio_alloc(gfp_mask,
	165	min(nr_sects, (sector_t)BIO_MAX_PAGES));
18edc8ea DM	166	if (!bio) {
18edc8ea DM	167	ret = -ENOMEM;
3f14d792	168	break;
18edc8ea	169	}
3f14d792 DM	170
	171	bio->bi_sector = sector;
	172	bio->bi_bdev = bdev;
	173	bio->bi_end_io = bio_batch_end_io;
dd3932ed	174	bio->bi_private = &bb;
3f14d792	175
0341aafb JA	176	while (nr_sects != 0) {
0341aafb JA	177	sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
3f14d792 DM	178	if (sz == 0)
	179	/* bio has maximum size possible */
	180	break;
	181	ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
	182	nr_sects -= ret >> 9;
	183	sector += ret >> 9;
	184	if (ret < (sz << 9))
	185	break;
	186	}
18edc8ea	187	ret = 0;
3f14d792 DM	188	issued++;
	189	submit_bio(WRITE, bio);
	190	}
3f14d792	191
dd3932ed CH	192	/* Wait for bios in-flight */
	193	while (issued != atomic_read(&bb.done))
	194	wait_for_completion(&wait);
3f14d792 DM	195
	196	if (!test_bit(BIO_UPTODATE, &bb.flags))
	197	/* One of bios in the batch was completed with error.*/
	198	ret = -EIO;
	199
	200	if (ret)
	201	goto out;
	202
	203	if (test_bit(BIO_EOPNOTSUPP, &bb.flags)) {
	204	ret = -EOPNOTSUPP;
	205	goto out;
	206	}
	207	if (nr_sects != 0)
	208	goto submit;
	209	out:
	210	return ret;
	211	}
	212	EXPORT_SYMBOL(blkdev_issue_zeroout);