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340 lines
8.8 KiB
340 lines
8.8 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Functions related to generic helpers functions |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/bio.h> |
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#include <linux/blkdev.h> |
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#include <linux/scatterlist.h> |
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#include "blk.h" |
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static sector_t bio_discard_limit(struct block_device *bdev, sector_t sector) |
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{ |
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unsigned int discard_granularity = bdev_discard_granularity(bdev); |
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sector_t granularity_aligned_sector; |
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if (bdev_is_partition(bdev)) |
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sector += bdev->bd_start_sect; |
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granularity_aligned_sector = |
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round_up(sector, discard_granularity >> SECTOR_SHIFT); |
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/* |
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* Make sure subsequent bios start aligned to the discard granularity if |
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* it needs to be split. |
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*/ |
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if (granularity_aligned_sector != sector) |
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return granularity_aligned_sector - sector; |
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/* |
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* Align the bio size to the discard granularity to make splitting the bio |
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* at discard granularity boundaries easier in the driver if needed. |
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*/ |
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return round_down(UINT_MAX, discard_granularity) >> SECTOR_SHIFT; |
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} |
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int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, |
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sector_t nr_sects, gfp_t gfp_mask, struct bio **biop) |
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{ |
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struct bio *bio = *biop; |
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sector_t bs_mask; |
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if (bdev_read_only(bdev)) |
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return -EPERM; |
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if (!bdev_max_discard_sectors(bdev)) |
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return -EOPNOTSUPP; |
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/* In case the discard granularity isn't set by buggy device driver */ |
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if (WARN_ON_ONCE(!bdev_discard_granularity(bdev))) { |
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pr_err_ratelimited("%pg: Error: discard_granularity is 0.\n", |
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bdev); |
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return -EOPNOTSUPP; |
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} |
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bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1; |
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if ((sector | nr_sects) & bs_mask) |
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return -EINVAL; |
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if (!nr_sects) |
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return -EINVAL; |
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while (nr_sects) { |
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sector_t req_sects = |
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min(nr_sects, bio_discard_limit(bdev, sector)); |
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bio = blk_next_bio(bio, bdev, 0, REQ_OP_DISCARD, gfp_mask); |
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bio->bi_iter.bi_sector = sector; |
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bio->bi_iter.bi_size = req_sects << 9; |
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sector += req_sects; |
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nr_sects -= req_sects; |
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/* |
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* We can loop for a long time in here, if someone does |
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* full device discards (like mkfs). Be nice and allow |
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* us to schedule out to avoid softlocking if preempt |
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* is disabled. |
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*/ |
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cond_resched(); |
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} |
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*biop = bio; |
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return 0; |
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} |
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EXPORT_SYMBOL(__blkdev_issue_discard); |
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/** |
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* blkdev_issue_discard - queue a discard |
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* @bdev: blockdev to issue discard for |
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* @sector: start sector |
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* @nr_sects: number of sectors to discard |
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* @gfp_mask: memory allocation flags (for bio_alloc) |
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* |
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* Description: |
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* Issue a discard request for the sectors in question. |
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*/ |
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int blkdev_issue_discard(struct block_device *bdev, sector_t sector, |
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sector_t nr_sects, gfp_t gfp_mask) |
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{ |
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struct bio *bio = NULL; |
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struct blk_plug plug; |
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int ret; |
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blk_start_plug(&plug); |
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ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, &bio); |
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if (!ret && bio) { |
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ret = submit_bio_wait(bio); |
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if (ret == -EOPNOTSUPP) |
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ret = 0; |
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bio_put(bio); |
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} |
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blk_finish_plug(&plug); |
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return ret; |
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} |
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EXPORT_SYMBOL(blkdev_issue_discard); |
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static int __blkdev_issue_write_zeroes(struct block_device *bdev, |
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sector_t sector, sector_t nr_sects, gfp_t gfp_mask, |
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struct bio **biop, unsigned flags) |
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{ |
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struct bio *bio = *biop; |
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unsigned int max_write_zeroes_sectors; |
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if (bdev_read_only(bdev)) |
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return -EPERM; |
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/* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */ |
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max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev); |
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if (max_write_zeroes_sectors == 0) |
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return -EOPNOTSUPP; |
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while (nr_sects) { |
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bio = blk_next_bio(bio, bdev, 0, REQ_OP_WRITE_ZEROES, gfp_mask); |
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bio->bi_iter.bi_sector = sector; |
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if (flags & BLKDEV_ZERO_NOUNMAP) |
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bio->bi_opf |= REQ_NOUNMAP; |
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if (nr_sects > max_write_zeroes_sectors) { |
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bio->bi_iter.bi_size = max_write_zeroes_sectors << 9; |
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nr_sects -= max_write_zeroes_sectors; |
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sector += max_write_zeroes_sectors; |
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} else { |
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bio->bi_iter.bi_size = nr_sects << 9; |
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nr_sects = 0; |
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} |
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cond_resched(); |
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} |
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*biop = bio; |
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return 0; |
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} |
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/* |
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* Convert a number of 512B sectors to a number of pages. |
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* The result is limited to a number of pages that can fit into a BIO. |
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* Also make sure that the result is always at least 1 (page) for the cases |
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* where nr_sects is lower than the number of sectors in a page. |
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*/ |
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static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects) |
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{ |
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sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512); |
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return min(pages, (sector_t)BIO_MAX_VECS); |
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} |
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static int __blkdev_issue_zero_pages(struct block_device *bdev, |
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sector_t sector, sector_t nr_sects, gfp_t gfp_mask, |
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struct bio **biop) |
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{ |
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struct bio *bio = *biop; |
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int bi_size = 0; |
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unsigned int sz; |
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if (bdev_read_only(bdev)) |
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return -EPERM; |
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while (nr_sects != 0) { |
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bio = blk_next_bio(bio, bdev, __blkdev_sectors_to_bio_pages(nr_sects), |
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REQ_OP_WRITE, gfp_mask); |
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bio->bi_iter.bi_sector = sector; |
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while (nr_sects != 0) { |
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sz = min((sector_t) PAGE_SIZE, nr_sects << 9); |
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bi_size = bio_add_page(bio, ZERO_PAGE(0), sz, 0); |
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nr_sects -= bi_size >> 9; |
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sector += bi_size >> 9; |
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if (bi_size < sz) |
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break; |
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} |
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cond_resched(); |
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} |
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*biop = bio; |
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return 0; |
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} |
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/** |
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* __blkdev_issue_zeroout - generate number of zero filed write bios |
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* @bdev: blockdev to issue |
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* @sector: start sector |
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* @nr_sects: number of sectors to write |
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* @gfp_mask: memory allocation flags (for bio_alloc) |
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* @biop: pointer to anchor bio |
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* @flags: controls detailed behavior |
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* |
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* Description: |
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* Zero-fill a block range, either using hardware offload or by explicitly |
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* writing zeroes to the device. |
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* |
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* If a device is using logical block provisioning, the underlying space will |
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* not be released if %flags contains BLKDEV_ZERO_NOUNMAP. |
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* |
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* If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return |
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* -EOPNOTSUPP if no explicit hardware offload for zeroing is provided. |
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*/ |
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int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, |
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sector_t nr_sects, gfp_t gfp_mask, struct bio **biop, |
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unsigned flags) |
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{ |
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int ret; |
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sector_t bs_mask; |
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bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1; |
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if ((sector | nr_sects) & bs_mask) |
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return -EINVAL; |
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ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask, |
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biop, flags); |
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if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK)) |
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return ret; |
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return __blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask, |
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biop); |
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} |
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EXPORT_SYMBOL(__blkdev_issue_zeroout); |
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/** |
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* blkdev_issue_zeroout - zero-fill a block range |
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* @bdev: blockdev to write |
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* @sector: start sector |
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* @nr_sects: number of sectors to write |
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* @gfp_mask: memory allocation flags (for bio_alloc) |
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* @flags: controls detailed behavior |
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* |
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* Description: |
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* Zero-fill a block range, either using hardware offload or by explicitly |
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* writing zeroes to the device. See __blkdev_issue_zeroout() for the |
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* valid values for %flags. |
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*/ |
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int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, |
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sector_t nr_sects, gfp_t gfp_mask, unsigned flags) |
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{ |
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int ret = 0; |
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sector_t bs_mask; |
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struct bio *bio; |
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struct blk_plug plug; |
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bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev); |
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bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1; |
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if ((sector | nr_sects) & bs_mask) |
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return -EINVAL; |
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retry: |
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bio = NULL; |
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blk_start_plug(&plug); |
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if (try_write_zeroes) { |
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ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, |
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gfp_mask, &bio, flags); |
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} else if (!(flags & BLKDEV_ZERO_NOFALLBACK)) { |
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ret = __blkdev_issue_zero_pages(bdev, sector, nr_sects, |
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gfp_mask, &bio); |
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} else { |
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/* No zeroing offload support */ |
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ret = -EOPNOTSUPP; |
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} |
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if (ret == 0 && bio) { |
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ret = submit_bio_wait(bio); |
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bio_put(bio); |
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} |
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blk_finish_plug(&plug); |
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if (ret && try_write_zeroes) { |
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if (!(flags & BLKDEV_ZERO_NOFALLBACK)) { |
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try_write_zeroes = false; |
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goto retry; |
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} |
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if (!bdev_write_zeroes_sectors(bdev)) { |
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/* |
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* Zeroing offload support was indicated, but the |
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* device reported ILLEGAL REQUEST (for some devices |
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* there is no non-destructive way to verify whether |
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* WRITE ZEROES is actually supported). |
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*/ |
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ret = -EOPNOTSUPP; |
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} |
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} |
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return ret; |
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} |
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EXPORT_SYMBOL(blkdev_issue_zeroout); |
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int blkdev_issue_secure_erase(struct block_device *bdev, sector_t sector, |
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sector_t nr_sects, gfp_t gfp) |
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{ |
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sector_t bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1; |
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unsigned int max_sectors = bdev_max_secure_erase_sectors(bdev); |
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struct bio *bio = NULL; |
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struct blk_plug plug; |
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int ret = 0; |
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if (max_sectors == 0) |
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return -EOPNOTSUPP; |
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if ((sector | nr_sects) & bs_mask) |
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return -EINVAL; |
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if (bdev_read_only(bdev)) |
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return -EPERM; |
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blk_start_plug(&plug); |
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for (;;) { |
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unsigned int len = min_t(sector_t, nr_sects, max_sectors); |
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bio = blk_next_bio(bio, bdev, 0, REQ_OP_SECURE_ERASE, gfp); |
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bio->bi_iter.bi_sector = sector; |
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bio->bi_iter.bi_size = len; |
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sector += len << SECTOR_SHIFT; |
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nr_sects -= len << SECTOR_SHIFT; |
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if (!nr_sects) { |
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ret = submit_bio_wait(bio); |
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bio_put(bio); |
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break; |
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} |
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cond_resched(); |
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} |
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blk_finish_plug(&plug); |
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return ret; |
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} |
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EXPORT_SYMBOL(blkdev_issue_secure_erase);
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