| // 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 (!q) |
| return -ENXIO; |
| |
| 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); |
| |
| /** |
| * __blkdev_issue_write_same - generate number of bios with same page |
| * @bdev: target blockdev |
| * @sector: start sector |
| * @nr_sects: number of sectors to write |
| * @gfp_mask: memory allocation flags (for bio_alloc) |
| * @page: page containing data to write |
| * @biop: pointer to anchor bio |
| * |
| * Description: |
| * Generate and issue number of bios(REQ_OP_WRITE_SAME) with same page. |
| */ |
| static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector, |
| sector_t nr_sects, gfp_t gfp_mask, struct page *page, |
| struct bio **biop) |
| { |
| struct request_queue *q = bdev_get_queue(bdev); |
| unsigned int max_write_same_sectors; |
| struct bio *bio = *biop; |
| sector_t bs_mask; |
| |
| if (!q) |
| return -ENXIO; |
| |
| if (bdev_read_only(bdev)) |
| return -EPERM; |
| |
| bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1; |
| if ((sector | nr_sects) & bs_mask) |
| return -EINVAL; |
| |
| if (!bdev_write_same(bdev)) |
| return -EOPNOTSUPP; |
| |
| /* Ensure that max_write_same_sectors doesn't overflow bi_size */ |
| max_write_same_sectors = bio_allowed_max_sectors(q); |
| |
| while (nr_sects) { |
| bio = blk_next_bio(bio, bdev, 1, REQ_OP_WRITE_SAME, gfp_mask); |
| bio->bi_iter.bi_sector = sector; |
| bio->bi_vcnt = 1; |
| bio->bi_io_vec->bv_page = page; |
| bio->bi_io_vec->bv_offset = 0; |
| bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev); |
| |
| if (nr_sects > max_write_same_sectors) { |
| bio->bi_iter.bi_size = max_write_same_sectors << 9; |
| nr_sects -= max_write_same_sectors; |
| sector += max_write_same_sectors; |
| } else { |
| bio->bi_iter.bi_size = nr_sects << 9; |
| nr_sects = 0; |
| } |
| cond_resched(); |
| } |
| |
| *biop = bio; |
| return 0; |
| } |
| |
| /** |
| * blkdev_issue_write_same - queue a write same operation |
| * @bdev: target blockdev |
| * @sector: start sector |
| * @nr_sects: number of sectors to write |
| * @gfp_mask: memory allocation flags (for bio_alloc) |
| * @page: page containing data |
| * |
| * Description: |
| * Issue a write same request for the sectors in question. |
| */ |
| int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, |
| sector_t nr_sects, gfp_t gfp_mask, |
| struct page *page) |
| { |
| struct bio *bio = NULL; |
| struct blk_plug plug; |
| int ret; |
| |
| blk_start_plug(&plug); |
| ret = __blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, page, |
| &bio); |
| if (ret == 0 && bio) { |
| ret = submit_bio_wait(bio); |
| bio_put(bio); |
| } |
| blk_finish_plug(&plug); |
| return ret; |
| } |
| EXPORT_SYMBOL(blkdev_issue_write_same); |
| |
| 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; |
| struct request_queue *q = bdev_get_queue(bdev); |
| |
| if (!q) |
| return -ENXIO; |
| |
| 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 request_queue *q = bdev_get_queue(bdev); |
| struct bio *bio = *biop; |
| int bi_size = 0; |
| unsigned int sz; |
| |
| if (!q) |
| return -ENXIO; |
| |
| 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); |