From eeadd68e2a5f6bfe0bf1038ec49e3a8d99eb5fe8 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 5 May 2025 10:11:25 +0200 Subject: block: remove bounce buffering support The block layer bounce buffering support is unused now, remove it. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: John Garry Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20250505081138.3435992-7-hch@lst.de Signed-off-by: Jens Axboe --- block/Makefile | 1 - block/blk-map.c | 5 +- block/blk-mq.c | 2 - block/blk-settings.c | 5 - block/blk.h | 17 ---- block/bounce.c | 267 --------------------------------------------------- 6 files changed, 1 insertion(+), 296 deletions(-) delete mode 100644 block/bounce.c (limited to 'block') diff --git a/block/Makefile b/block/Makefile index 3a941dc0d27f..36033c0f07bc 100644 --- a/block/Makefile +++ b/block/Makefile @@ -11,7 +11,6 @@ obj-y := bdev.o fops.o bio.o elevator.o blk-core.o blk-sysfs.o \ genhd.o ioprio.o badblocks.o partitions/ blk-rq-qos.o \ disk-events.o blk-ia-ranges.o early-lookup.o -obj-$(CONFIG_BOUNCE) += bounce.o obj-$(CONFIG_BLK_DEV_BSG_COMMON) += bsg.o obj-$(CONFIG_BLK_DEV_BSGLIB) += bsg-lib.o obj-$(CONFIG_BLK_CGROUP) += blk-cgroup.o diff --git a/block/blk-map.c b/block/blk-map.c index d2f22744b3d1..cadbf11b50a3 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -556,8 +556,6 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq, if (map_data) copy = true; - else if (blk_queue_may_bounce(q)) - copy = true; else if (iov_iter_alignment(iter) & align) copy = true; else if (iov_iter_is_bvec(iter)) @@ -713,8 +711,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf, if (!len || !kbuf) return -EINVAL; - if (!blk_rq_aligned(q, addr, len) || object_is_on_stack(kbuf) || - blk_queue_may_bounce(q)) + if (!blk_rq_aligned(q, addr, len) || object_is_on_stack(kbuf)) bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading); else bio = bio_map_kern(q, kbuf, len, gfp_mask); diff --git a/block/blk-mq.c b/block/blk-mq.c index 796baeccd37b..83c651a7facd 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3144,8 +3144,6 @@ void blk_mq_submit_bio(struct bio *bio) goto new_request; } - bio = blk_queue_bounce(bio, q); - /* * The cached request already holds a q_usage_counter reference and we * don't have to acquire a new one if we use it. diff --git a/block/blk-settings.c b/block/blk-settings.c index 4817e7ca03f8..a000daafbfb4 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -124,11 +124,6 @@ static int blk_validate_integrity_limits(struct queue_limits *lim) return 0; } - if (lim->features & BLK_FEAT_BOUNCE_HIGH) { - pr_warn("no bounce buffer support for integrity metadata\n"); - return -EINVAL; - } - if (!IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY)) { pr_warn("integrity support disabled.\n"); return -EINVAL; diff --git a/block/blk.h b/block/blk.h index 328075787814..ff21f234b62f 100644 --- a/block/blk.h +++ b/block/blk.h @@ -443,23 +443,6 @@ static inline void ioc_clear_queue(struct request_queue *q) } #endif /* CONFIG_BLK_ICQ */ -struct bio *__blk_queue_bounce(struct bio *bio, struct request_queue *q); - -static inline bool blk_queue_may_bounce(struct request_queue *q) -{ - return IS_ENABLED(CONFIG_BOUNCE) && - (q->limits.features & BLK_FEAT_BOUNCE_HIGH) && - max_low_pfn >= max_pfn; -} - -static inline struct bio *blk_queue_bounce(struct bio *bio, - struct request_queue *q) -{ - if (unlikely(blk_queue_may_bounce(q) && bio_has_data(bio))) - return __blk_queue_bounce(bio, q); - return bio; -} - #ifdef CONFIG_BLK_DEV_ZONED void disk_init_zone_resources(struct gendisk *disk); void disk_free_zone_resources(struct gendisk *disk); diff --git a/block/bounce.c b/block/bounce.c deleted file mode 100644 index 09a9616cf209..000000000000 --- a/block/bounce.c +++ /dev/null @@ -1,267 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* bounce buffer handling for block devices - * - * - Split from highmem.c - */ - -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include "blk.h" -#include "blk-cgroup.h" - -#define POOL_SIZE 64 -#define ISA_POOL_SIZE 16 - -static struct bio_set bounce_bio_set, bounce_bio_split; -static mempool_t page_pool; - -static void init_bounce_bioset(void) -{ - static bool bounce_bs_setup; - int ret; - - if (bounce_bs_setup) - return; - - ret = bioset_init(&bounce_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS); - BUG_ON(ret); - - ret = bioset_init(&bounce_bio_split, BIO_POOL_SIZE, 0, 0); - BUG_ON(ret); - bounce_bs_setup = true; -} - -static __init int init_emergency_pool(void) -{ - int ret; - -#ifndef CONFIG_MEMORY_HOTPLUG - if (max_pfn <= max_low_pfn) - return 0; -#endif - - ret = mempool_init_page_pool(&page_pool, POOL_SIZE, 0); - BUG_ON(ret); - pr_info("pool size: %d pages\n", POOL_SIZE); - - init_bounce_bioset(); - return 0; -} - -__initcall(init_emergency_pool); - -/* - * Simple bounce buffer support for highmem pages. Depending on the - * queue gfp mask set, *to may or may not be a highmem page. kmap it - * always, it will do the Right Thing - */ -static void copy_to_high_bio_irq(struct bio *to, struct bio *from) -{ - struct bio_vec tovec, fromvec; - struct bvec_iter iter; - /* - * The bio of @from is created by bounce, so we can iterate - * its bvec from start to end, but the @from->bi_iter can't be - * trusted because it might be changed by splitting. - */ - struct bvec_iter from_iter = BVEC_ITER_ALL_INIT; - - bio_for_each_segment(tovec, to, iter) { - fromvec = bio_iter_iovec(from, from_iter); - if (tovec.bv_page != fromvec.bv_page) { - /* - * fromvec->bv_offset and fromvec->bv_len might have - * been modified by the block layer, so use the original - * copy, bounce_copy_vec already uses tovec->bv_len - */ - memcpy_to_bvec(&tovec, page_address(fromvec.bv_page) + - tovec.bv_offset); - } - bio_advance_iter(from, &from_iter, tovec.bv_len); - } -} - -static void bounce_end_io(struct bio *bio) -{ - struct bio *bio_orig = bio->bi_private; - struct bio_vec *bvec, orig_vec; - struct bvec_iter orig_iter = bio_orig->bi_iter; - struct bvec_iter_all iter_all; - - /* - * free up bounce indirect pages used - */ - bio_for_each_segment_all(bvec, bio, iter_all) { - orig_vec = bio_iter_iovec(bio_orig, orig_iter); - if (bvec->bv_page != orig_vec.bv_page) { - dec_zone_page_state(bvec->bv_page, NR_BOUNCE); - mempool_free(bvec->bv_page, &page_pool); - } - bio_advance_iter(bio_orig, &orig_iter, orig_vec.bv_len); - } - - bio_orig->bi_status = bio->bi_status; - bio_endio(bio_orig); - bio_put(bio); -} - -static void bounce_end_io_write(struct bio *bio) -{ - bounce_end_io(bio); -} - -static void bounce_end_io_read(struct bio *bio) -{ - struct bio *bio_orig = bio->bi_private; - - if (!bio->bi_status) - copy_to_high_bio_irq(bio_orig, bio); - - bounce_end_io(bio); -} - -static struct bio *bounce_clone_bio(struct bio *bio_src) -{ - struct bvec_iter iter; - struct bio_vec bv; - struct bio *bio; - - /* - * Pre immutable biovecs, __bio_clone() used to just do a memcpy from - * bio_src->bi_io_vec to bio->bi_io_vec. - * - * We can't do that anymore, because: - * - * - The point of cloning the biovec is to produce a bio with a biovec - * the caller can modify: bi_idx and bi_bvec_done should be 0. - * - * - The original bio could've had more than BIO_MAX_VECS biovecs; if - * we tried to clone the whole thing bio_alloc_bioset() would fail. - * But the clone should succeed as long as the number of biovecs we - * actually need to allocate is fewer than BIO_MAX_VECS. - * - * - Lastly, bi_vcnt should not be looked at or relied upon by code - * that does not own the bio - reason being drivers don't use it for - * iterating over the biovec anymore, so expecting it to be kept up - * to date (i.e. for clones that share the parent biovec) is just - * asking for trouble and would force extra work. - */ - bio = bio_alloc_bioset(bio_src->bi_bdev, bio_segments(bio_src), - bio_src->bi_opf, GFP_NOIO, &bounce_bio_set); - if (bio_flagged(bio_src, BIO_REMAPPED)) - bio_set_flag(bio, BIO_REMAPPED); - bio->bi_ioprio = bio_src->bi_ioprio; - bio->bi_write_hint = bio_src->bi_write_hint; - bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector; - bio->bi_iter.bi_size = bio_src->bi_iter.bi_size; - - switch (bio_op(bio)) { - case REQ_OP_DISCARD: - case REQ_OP_SECURE_ERASE: - case REQ_OP_WRITE_ZEROES: - break; - default: - bio_for_each_segment(bv, bio_src, iter) - bio->bi_io_vec[bio->bi_vcnt++] = bv; - break; - } - - if (bio_crypt_clone(bio, bio_src, GFP_NOIO) < 0) - goto err_put; - - if (bio_integrity(bio_src) && - bio_integrity_clone(bio, bio_src, GFP_NOIO) < 0) - goto err_put; - - bio_clone_blkg_association(bio, bio_src); - - return bio; - -err_put: - bio_put(bio); - return NULL; -} - -struct bio *__blk_queue_bounce(struct bio *bio_orig, struct request_queue *q) -{ - struct bio *bio; - int rw = bio_data_dir(bio_orig); - struct bio_vec *to, from; - struct bvec_iter iter; - unsigned i = 0, bytes = 0; - bool bounce = false; - int sectors; - - bio_for_each_segment(from, bio_orig, iter) { - if (i++ < BIO_MAX_VECS) - bytes += from.bv_len; - if (PageHighMem(from.bv_page)) - bounce = true; - } - if (!bounce) - return bio_orig; - - /* - * Individual bvecs might not be logical block aligned. Round down - * the split size so that each bio is properly block size aligned, - * even if we do not use the full hardware limits. - */ - sectors = ALIGN_DOWN(bytes, queue_logical_block_size(q)) >> - SECTOR_SHIFT; - if (sectors < bio_sectors(bio_orig)) { - bio = bio_split(bio_orig, sectors, GFP_NOIO, &bounce_bio_split); - bio_chain(bio, bio_orig); - submit_bio_noacct(bio_orig); - bio_orig = bio; - } - bio = bounce_clone_bio(bio_orig); - - /* - * Bvec table can't be updated by bio_for_each_segment_all(), - * so retrieve bvec from the table directly. This way is safe - * because the 'bio' is single-page bvec. - */ - for (i = 0, to = bio->bi_io_vec; i < bio->bi_vcnt; to++, i++) { - struct page *bounce_page; - - if (!PageHighMem(to->bv_page)) - continue; - - bounce_page = mempool_alloc(&page_pool, GFP_NOIO); - inc_zone_page_state(bounce_page, NR_BOUNCE); - - if (rw == WRITE) { - flush_dcache_page(to->bv_page); - memcpy_from_bvec(page_address(bounce_page), to); - } - to->bv_page = bounce_page; - } - - trace_block_bio_bounce(bio_orig); - - bio->bi_flags |= (1 << BIO_BOUNCED); - - if (rw == READ) - bio->bi_end_io = bounce_end_io_read; - else - bio->bi_end_io = bounce_end_io_write; - - bio->bi_private = bio_orig; - return bio; -} -- cgit v1.2.3