319 lines
8.6 KiB
C
319 lines
8.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* 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"
|
|
|
|
int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
|
|
sector_t nr_sects, gfp_t gfp_mask, int flags,
|
|
struct bio **biop)
|
|
{
|
|
struct request_queue *q = bdev_get_queue(bdev);
|
|
struct bio *bio = *biop;
|
|
unsigned int op;
|
|
sector_t bs_mask, part_offset = 0;
|
|
|
|
if (bdev_read_only(bdev))
|
|
return -EPERM;
|
|
|
|
if (flags & BLKDEV_DISCARD_SECURE) {
|
|
if (!blk_queue_secure_erase(q))
|
|
return -EOPNOTSUPP;
|
|
op = REQ_OP_SECURE_ERASE;
|
|
} else {
|
|
if (!blk_queue_discard(q))
|
|
return -EOPNOTSUPP;
|
|
op = REQ_OP_DISCARD;
|
|
}
|
|
|
|
/* In case the discard granularity isn't set by buggy device driver */
|
|
if (WARN_ON_ONCE(!q->limits.discard_granularity)) {
|
|
char dev_name[BDEVNAME_SIZE];
|
|
|
|
bdevname(bdev, dev_name);
|
|
pr_err_ratelimited("%s: Error: discard_granularity is 0.\n", dev_name);
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
|
|
if ((sector | nr_sects) & bs_mask)
|
|
return -EINVAL;
|
|
|
|
if (!nr_sects)
|
|
return -EINVAL;
|
|
|
|
/* In case the discard request is in a partition */
|
|
if (bdev_is_partition(bdev))
|
|
part_offset = bdev->bd_start_sect;
|
|
|
|
while (nr_sects) {
|
|
sector_t granularity_aligned_lba, req_sects;
|
|
sector_t sector_mapped = sector + part_offset;
|
|
|
|
granularity_aligned_lba = round_up(sector_mapped,
|
|
q->limits.discard_granularity >> SECTOR_SHIFT);
|
|
|
|
/*
|
|
* Check whether the discard bio starts at a discard_granularity
|
|
* aligned LBA,
|
|
* - If no: set (granularity_aligned_lba - sector_mapped) to
|
|
* bi_size of the first split bio, then the second bio will
|
|
* start at a discard_granularity aligned LBA on the device.
|
|
* - If yes: use bio_aligned_discard_max_sectors() as the max
|
|
* possible bi_size of the first split bio. Then when this bio
|
|
* is split in device drive, the split ones are very probably
|
|
* to be aligned to discard_granularity of the device's queue.
|
|
*/
|
|
if (granularity_aligned_lba == sector_mapped)
|
|
req_sects = min_t(sector_t, nr_sects,
|
|
bio_aligned_discard_max_sectors(q));
|
|
else
|
|
req_sects = min_t(sector_t, nr_sects,
|
|
granularity_aligned_lba - sector_mapped);
|
|
|
|
WARN_ON_ONCE((req_sects << 9) > UINT_MAX);
|
|
|
|
bio = blk_next_bio(bio, bdev, 0, op, gfp_mask);
|
|
bio->bi_iter.bi_sector = sector;
|
|
bio->bi_iter.bi_size = req_sects << 9;
|
|
sector += req_sects;
|
|
nr_sects -= req_sects;
|
|
|
|
/*
|
|
* We can loop for a long time in here, if someone does
|
|
* full device discards (like mkfs). Be nice and allow
|
|
* us to schedule out to avoid softlocking if preempt
|
|
* is disabled.
|
|
*/
|
|
cond_resched();
|
|
}
|
|
|
|
*biop = bio;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(__blkdev_issue_discard);
|
|
|
|
/**
|
|
* 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_DISCARD_* 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)
|
|
{
|
|
struct bio *bio = NULL;
|
|
struct blk_plug plug;
|
|
int ret;
|
|
|
|
blk_start_plug(&plug);
|
|
ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, flags,
|
|
&bio);
|
|
if (!ret && bio) {
|
|
ret = submit_bio_wait(bio);
|
|
if (ret == -EOPNOTSUPP)
|
|
ret = 0;
|
|
bio_put(bio);
|
|
}
|
|
blk_finish_plug(&plug);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(blkdev_issue_discard);
|
|
|
|
static int __blkdev_issue_write_zeroes(struct block_device *bdev,
|
|
sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
|
|
struct bio **biop, unsigned flags)
|
|
{
|
|
struct bio *bio = *biop;
|
|
unsigned int max_write_zeroes_sectors;
|
|
|
|
if (bdev_read_only(bdev))
|
|
return -EPERM;
|
|
|
|
/* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */
|
|
max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev);
|
|
|
|
if (max_write_zeroes_sectors == 0)
|
|
return -EOPNOTSUPP;
|
|
|
|
while (nr_sects) {
|
|
bio = blk_next_bio(bio, bdev, 0, REQ_OP_WRITE_ZEROES, gfp_mask);
|
|
bio->bi_iter.bi_sector = sector;
|
|
if (flags & BLKDEV_ZERO_NOUNMAP)
|
|
bio->bi_opf |= REQ_NOUNMAP;
|
|
|
|
if (nr_sects > max_write_zeroes_sectors) {
|
|
bio->bi_iter.bi_size = max_write_zeroes_sectors << 9;
|
|
nr_sects -= max_write_zeroes_sectors;
|
|
sector += max_write_zeroes_sectors;
|
|
} else {
|
|
bio->bi_iter.bi_size = nr_sects << 9;
|
|
nr_sects = 0;
|
|
}
|
|
cond_resched();
|
|
}
|
|
|
|
*biop = bio;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Convert a number of 512B sectors to a number of pages.
|
|
* The result is limited to a number of pages that can fit into a BIO.
|
|
* Also make sure that the result is always at least 1 (page) for the cases
|
|
* where nr_sects is lower than the number of sectors in a page.
|
|
*/
|
|
static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
|
|
{
|
|
sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
|
|
|
|
return min(pages, (sector_t)BIO_MAX_VECS);
|
|
}
|
|
|
|
static int __blkdev_issue_zero_pages(struct block_device *bdev,
|
|
sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
|
|
struct bio **biop)
|
|
{
|
|
struct bio *bio = *biop;
|
|
int bi_size = 0;
|
|
unsigned int sz;
|
|
|
|
if (bdev_read_only(bdev))
|
|
return -EPERM;
|
|
|
|
while (nr_sects != 0) {
|
|
bio = blk_next_bio(bio, bdev, __blkdev_sectors_to_bio_pages(nr_sects),
|
|
REQ_OP_WRITE, gfp_mask);
|
|
bio->bi_iter.bi_sector = sector;
|
|
|
|
while (nr_sects != 0) {
|
|
sz = min((sector_t) PAGE_SIZE, nr_sects << 9);
|
|
bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0);
|
|
nr_sects -= bi_size >> 9;
|
|
sector += bi_size >> 9;
|
|
if (bi_size < sz)
|
|
break;
|
|
}
|
|
cond_resched();
|
|
}
|
|
|
|
*biop = bio;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* __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)
|
|
* @biop: pointer to anchor bio
|
|
* @flags: controls detailed behavior
|
|
*
|
|
* Description:
|
|
* Zero-fill a block range, either using hardware offload or by explicitly
|
|
* writing zeroes to the device.
|
|
*
|
|
* If a device is using logical block provisioning, the underlying space will
|
|
* not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
|
|
*
|
|
* If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return
|
|
* -EOPNOTSUPP if no explicit hardware offload for zeroing is provided.
|
|
*/
|
|
int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
|
|
sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
|
|
unsigned flags)
|
|
{
|
|
int ret;
|
|
sector_t bs_mask;
|
|
|
|
bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
|
|
if ((sector | nr_sects) & bs_mask)
|
|
return -EINVAL;
|
|
|
|
ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,
|
|
biop, flags);
|
|
if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK))
|
|
return ret;
|
|
|
|
return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,
|
|
biop);
|
|
}
|
|
EXPORT_SYMBOL(__blkdev_issue_zeroout);
|
|
|
|
/**
|
|
* blkdev_issue_zeroout - zero-fill a block range
|
|
* @bdev: blockdev to write
|
|
* @sector: start sector
|
|
* @nr_sects: number of sectors to write
|
|
* @gfp_mask: memory allocation flags (for bio_alloc)
|
|
* @flags: controls detailed behavior
|
|
*
|
|
* Description:
|
|
* Zero-fill a block range, either using hardware offload or by explicitly
|
|
* writing zeroes to the device. See __blkdev_issue_zeroout() for the
|
|
* valid values for %flags.
|
|
*/
|
|
int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
|
|
sector_t nr_sects, gfp_t gfp_mask, unsigned flags)
|
|
{
|
|
int ret = 0;
|
|
sector_t bs_mask;
|
|
struct bio *bio;
|
|
struct blk_plug plug;
|
|
bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);
|
|
|
|
bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
|
|
if ((sector | nr_sects) & bs_mask)
|
|
return -EINVAL;
|
|
|
|
retry:
|
|
bio = NULL;
|
|
blk_start_plug(&plug);
|
|
if (try_write_zeroes) {
|
|
ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects,
|
|
gfp_mask, &bio, flags);
|
|
} else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
|
|
ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects,
|
|
gfp_mask, &bio);
|
|
} else {
|
|
/* No zeroing offload support */
|
|
ret = -EOPNOTSUPP;
|
|
}
|
|
if (ret == 0 && bio) {
|
|
ret = submit_bio_wait(bio);
|
|
bio_put(bio);
|
|
}
|
|
blk_finish_plug(&plug);
|
|
if (ret && try_write_zeroes) {
|
|
if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {
|
|
try_write_zeroes = false;
|
|
goto retry;
|
|
}
|
|
if (!bdev_write_zeroes_sectors(bdev)) {
|
|
/*
|
|
* Zeroing offload support was indicated, but the
|
|
* device reported ILLEGAL REQUEST (for some devices
|
|
* there is no non-destructive way to verify whether
|
|
* WRITE ZEROES is actually supported).
|
|
*/
|
|
ret = -EOPNOTSUPP;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(blkdev_issue_zeroout);
|