| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Kent Overstreet | 1811 | 25.15% | 34 | 15.25% |
| Jens Axboe | 1623 | 22.54% | 35 | 15.70% |
| Christoph Hellwig | 699 | 9.71% | 21 | 9.42% |
| FUJITA Tomonori | 370 | 5.14% | 11 | 4.93% |
| Linus Torvalds | 365 | 5.07% | 6 | 2.69% |
| Al Viro | 269 | 3.74% | 15 | 6.73% |
| Andrew Morton | 229 | 3.18% | 9 | 4.04% |
| Michael Christie | 189 | 2.62% | 4 | 1.79% |
| Dave Olien | 181 | 2.51% | 1 | 0.45% |
| Dennis Zhou | 173 | 2.40% | 7 | 3.14% |
| Neil Brown | 158 | 2.19% | 6 | 2.69% |
| Gu Zheng | 130 | 1.81% | 1 | 0.45% |
| Dongsu Park | 101 | 1.40% | 1 | 0.45% |
| Maurizio Lombardi | 89 | 1.24% | 1 | 0.45% |
| Tejun Heo | 79 | 1.10% | 5 | 2.24% |
| Martin Wilck | 77 | 1.07% | 2 | 0.90% |
| Josef Bacik | 61 | 0.85% | 2 | 0.90% |
| H Hartley Sweeten | 45 | 0.62% | 1 | 0.45% |
| James Bottomley | 44 | 0.61% | 1 | 0.45% |
| Martin K. Petersen | 41 | 0.57% | 5 | 2.24% |
| Ilya Loginov | 37 | 0.51% | 1 | 0.45% |
| Patrick Mansfield | 34 | 0.47% | 1 | 0.45% |
| Shaohua Li | 34 | 0.47% | 4 | 1.79% |
| Michael Callahan | 31 | 0.43% | 1 | 0.45% |
| Ingo Molnar | 26 | 0.36% | 1 | 0.45% |
| Andi Kleen | 26 | 0.36% | 1 | 0.45% |
| Lei Ming | 25 | 0.35% | 1 | 0.45% |
| Paolo Valente | 25 | 0.35% | 1 | 0.45% |
| Jun'ichi Nomura | 21 | 0.29% | 1 | 0.45% |
| Vitaly Mayatskikh | 20 | 0.28% | 1 | 0.45% |
| Hannes Reinecke | 19 | 0.26% | 2 | 0.90% |
| Roland Dreier | 17 | 0.24% | 1 | 0.45% |
| Mikulas Patocka | 16 | 0.22% | 2 | 0.90% |
| Keith Busch | 13 | 0.18% | 3 | 1.35% |
| Dmitriy Monakhov | 12 | 0.17% | 1 | 0.45% |
| Anna Leuschner | 12 | 0.17% | 1 | 0.45% |
| David Howells | 10 | 0.14% | 2 | 0.90% |
| Alexey Khoroshilov | 9 | 0.12% | 1 | 0.45% |
| Subhash Peddamallu | 8 | 0.11% | 1 | 0.45% |
| Michael Lyle | 8 | 0.11% | 1 | 0.45% |
| Byungchul Park | 7 | 0.10% | 1 | 0.45% |
| Mike Snitzer | 6 | 0.08% | 1 | 0.45% |
| Guoqing Jiang | 5 | 0.07% | 1 | 0.45% |
| Mel Gorman | 5 | 0.07% | 1 | 0.45% |
| Geliang Tang | 5 | 0.07% | 1 | 0.45% |
| Peter Osterlund | 4 | 0.06% | 1 | 0.45% |
| Thomas Gleixner | 4 | 0.06% | 1 | 0.45% |
| Omar Sandoval | 4 | 0.06% | 1 | 0.45% |
| Bart Van Assche | 4 | 0.06% | 2 | 0.90% |
| Kirill A. Shutemov | 3 | 0.04% | 1 | 0.45% |
| Randy Dunlap | 3 | 0.04% | 3 | 1.35% |
| Kees Cook | 2 | 0.03% | 1 | 0.45% |
| Adrian Bunk | 2 | 0.03% | 2 | 0.90% |
| Thiago Farina | 2 | 0.03% | 1 | 0.45% |
| Artem B. Bityutskiy | 1 | 0.01% | 1 | 0.45% |
| Paul Gortmaker | 1 | 0.01% | 1 | 0.45% |
| Stephane Gasparini | 1 | 0.01% | 1 | 0.45% |
| Jan Kara | 1 | 0.01% | 1 | 0.45% |
| Li Zefan | 1 | 0.01% | 1 | 0.45% |
| Greg Edwards | 1 | 0.01% | 1 | 0.45% |
| Dan Carpenter | 1 | 0.01% | 1 | 0.45% |
| Christoph Lameter | 1 | 0.01% | 1 | 0.45% |
| Goldwyn Rodrigues | 1 | 0.01% | 1 | 0.45% |
| Total | 7202 | 223 |
/* * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public Licens * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- * */ #include <linux/mm.h> #include <linux/swap.h> #include <linux/bio.h> #include <linux/blkdev.h> #include <linux/uio.h> #include <linux/iocontext.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/export.h> #include <linux/mempool.h> #include <linux/workqueue.h> #include <linux/cgroup.h> #include <linux/blk-cgroup.h> #include <trace/events/block.h> #include "blk.h" #include "blk-rq-qos.h" /* * Test patch to inline a certain number of bi_io_vec's inside the bio * itself, to shrink a bio data allocation from two mempool calls to one */ #define BIO_INLINE_VECS 4 /* * if you change this list, also change bvec_alloc or things will * break badly! cannot be bigger than what you can fit into an * unsigned short */ #define BV(x, n) { .nr_vecs = x, .name = "biovec-"#n } static struct biovec_slab bvec_slabs[BVEC_POOL_NR] __read_mostly = { BV(1, 1), BV(4, 4), BV(16, 16), BV(64, 64), BV(128, 128), BV(BIO_MAX_PAGES, max), }; #undef BV /* * fs_bio_set is the bio_set containing bio and iovec memory pools used by * IO code that does not need private memory pools. */ struct bio_set fs_bio_set; EXPORT_SYMBOL(fs_bio_set); /* * Our slab pool management */ struct bio_slab { struct kmem_cache *slab; unsigned int slab_ref; unsigned int slab_size; char name[8]; }; static DEFINE_MUTEX(bio_slab_lock); static struct bio_slab *bio_slabs; static unsigned int bio_slab_nr, bio_slab_max; static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size) { unsigned int sz = sizeof(struct bio) + extra_size; struct kmem_cache *slab = NULL; struct bio_slab *bslab, *new_bio_slabs; unsigned int new_bio_slab_max; unsigned int i, entry = -1; mutex_lock(&bio_slab_lock); i = 0; while (i < bio_slab_nr) { bslab = &bio_slabs[i]; if (!bslab->slab && entry == -1) entry = i; else if (bslab->slab_size == sz) { slab = bslab->slab; bslab->slab_ref++; break; } i++; } if (slab) goto out_unlock; if (bio_slab_nr == bio_slab_max && entry == -1) { new_bio_slab_max = bio_slab_max << 1; new_bio_slabs = krealloc(bio_slabs, new_bio_slab_max * sizeof(struct bio_slab), GFP_KERNEL); if (!new_bio_slabs) goto out_unlock; bio_slab_max = new_bio_slab_max; bio_slabs = new_bio_slabs; } if (entry == -1) entry = bio_slab_nr++; bslab = &bio_slabs[entry]; snprintf(bslab->name, sizeof(bslab->name), "bio-%d", entry); slab = kmem_cache_create(bslab->name, sz, ARCH_KMALLOC_MINALIGN, SLAB_HWCACHE_ALIGN, NULL); if (!slab) goto out_unlock; bslab->slab = slab; bslab->slab_ref = 1; bslab->slab_size = sz; out_unlock: mutex_unlock(&bio_slab_lock); return slab; } static void bio_put_slab(struct bio_set *bs) { struct bio_slab *bslab = NULL; unsigned int i; mutex_lock(&bio_slab_lock); for (i = 0; i < bio_slab_nr; i++) { if (bs->bio_slab == bio_slabs[i].slab) { bslab = &bio_slabs[i]; break; } } if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n")) goto out; WARN_ON(!bslab->slab_ref); if (--bslab->slab_ref) goto out; kmem_cache_destroy(bslab->slab); bslab->slab = NULL; out: mutex_unlock(&bio_slab_lock); } unsigned int bvec_nr_vecs(unsigned short idx) { return bvec_slabs[--idx].nr_vecs; } void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned int idx) { if (!idx) return; idx--; BIO_BUG_ON(idx >= BVEC_POOL_NR); if (idx == BVEC_POOL_MAX) { mempool_free(bv, pool); } else { struct biovec_slab *bvs = bvec_slabs + idx; kmem_cache_free(bvs->slab, bv); } } struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx, mempool_t *pool) { struct bio_vec *bvl; /* * see comment near bvec_array define! */ switch (nr) { case 1: *idx = 0; break; case 2 ... 4: *idx = 1; break; case 5 ... 16: *idx = 2; break; case 17 ... 64: *idx = 3; break; case 65 ... 128: *idx = 4; break; case 129 ... BIO_MAX_PAGES: *idx = 5; break; default: return NULL; } /* * idx now points to the pool we want to allocate from. only the * 1-vec entry pool is mempool backed. */ if (*idx == BVEC_POOL_MAX) { fallback: bvl = mempool_alloc(pool, gfp_mask); } else { struct biovec_slab *bvs = bvec_slabs + *idx; gfp_t __gfp_mask = gfp_mask & ~(__GFP_DIRECT_RECLAIM | __GFP_IO); /* * Make this allocation restricted and don't dump info on * allocation failures, since we'll fallback to the mempool * in case of failure. */ __gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; /* * Try a slab allocation. If this fails and __GFP_DIRECT_RECLAIM * is set, retry with the 1-entry mempool */ bvl = kmem_cache_alloc(bvs->slab, __gfp_mask); if (unlikely(!bvl && (gfp_mask & __GFP_DIRECT_RECLAIM))) { *idx = BVEC_POOL_MAX; goto fallback; } } (*idx)++; return bvl; } void bio_uninit(struct bio *bio) { bio_disassociate_task(bio); } EXPORT_SYMBOL(bio_uninit); static void bio_free(struct bio *bio) { struct bio_set *bs = bio->bi_pool; void *p; bio_uninit(bio); if (bs) { bvec_free(&bs->bvec_pool, bio->bi_io_vec, BVEC_POOL_IDX(bio)); /* * If we have front padding, adjust the bio pointer before freeing */ p = bio; p -= bs->front_pad; mempool_free(p, &bs->bio_pool); } else { /* Bio was allocated by bio_kmalloc() */ kfree(bio); } } /* * Users of this function have their own bio allocation. Subsequently, * they must remember to pair any call to bio_init() with bio_uninit() * when IO has completed, or when the bio is released. */ void bio_init(struct bio *bio, struct bio_vec *table, unsigned short max_vecs) { memset(bio, 0, sizeof(*bio)); atomic_set(&bio->__bi_remaining, 1); atomic_set(&bio->__bi_cnt, 1); bio->bi_io_vec = table; bio->bi_max_vecs = max_vecs; } EXPORT_SYMBOL(bio_init); /** * bio_reset - reinitialize a bio * @bio: bio to reset * * Description: * After calling bio_reset(), @bio will be in the same state as a freshly * allocated bio returned bio bio_alloc_bioset() - the only fields that are * preserved are the ones that are initialized by bio_alloc_bioset(). See * comment in struct bio. */ void bio_reset(struct bio *bio) { unsigned long flags = bio->bi_flags & (~0UL << BIO_RESET_BITS); bio_uninit(bio); memset(bio, 0, BIO_RESET_BYTES); bio->bi_flags = flags; atomic_set(&bio->__bi_remaining, 1); } EXPORT_SYMBOL(bio_reset); static struct bio *__bio_chain_endio(struct bio *bio) { struct bio *parent = bio->bi_private; if (!parent->bi_status) parent->bi_status = bio->bi_status; bio_put(bio); return parent; } static void bio_chain_endio(struct bio *bio) { bio_endio(__bio_chain_endio(bio)); } /** * bio_chain - chain bio completions * @bio: the target bio * @parent: the @bio's parent bio * * The caller won't have a bi_end_io called when @bio completes - instead, * @parent's bi_end_io won't be called until both @parent and @bio have * completed; the chained bio will also be freed when it completes. * * The caller must not set bi_private or bi_end_io in @bio. */ void bio_chain(struct bio *bio, struct bio *parent) { BUG_ON(bio->bi_private || bio->bi_end_io); bio->bi_private = parent; bio->bi_end_io = bio_chain_endio; bio_inc_remaining(parent); } EXPORT_SYMBOL(bio_chain); static void bio_alloc_rescue(struct work_struct *work) { struct bio_set *bs = container_of(work, struct bio_set, rescue_work); struct bio *bio; while (1) { spin_lock(&bs->rescue_lock); bio = bio_list_pop(&bs->rescue_list); spin_unlock(&bs->rescue_lock); if (!bio) break; generic_make_request(bio); } } static void punt_bios_to_rescuer(struct bio_set *bs) { struct bio_list punt, nopunt; struct bio *bio; if (WARN_ON_ONCE(!bs->rescue_workqueue)) return; /* * In order to guarantee forward progress we must punt only bios that * were allocated from this bio_set; otherwise, if there was a bio on * there for a stacking driver higher up in the stack, processing it * could require allocating bios from this bio_set, and doing that from * our own rescuer would be bad. * * Since bio lists are singly linked, pop them all instead of trying to * remove from the middle of the list: */ bio_list_init(&punt); bio_list_init(&nopunt); while ((bio = bio_list_pop(¤t->bio_list[0]))) bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio); current->bio_list[0] = nopunt; bio_list_init(&nopunt); while ((bio = bio_list_pop(¤t->bio_list[1]))) bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio); current->bio_list[1] = nopunt; spin_lock(&bs->rescue_lock); bio_list_merge(&bs->rescue_list, &punt); spin_unlock(&bs->rescue_lock); queue_work(bs->rescue_workqueue, &bs->rescue_work); } /** * bio_alloc_bioset - allocate a bio for I/O * @gfp_mask: the GFP_* mask given to the slab allocator * @nr_iovecs: number of iovecs to pre-allocate * @bs: the bio_set to allocate from. * * Description: * If @bs is NULL, uses kmalloc() to allocate the bio; else the allocation is * backed by the @bs's mempool. * * When @bs is not NULL, if %__GFP_DIRECT_RECLAIM is set then bio_alloc will * always be able to allocate a bio. This is due to the mempool guarantees. * To make this work, callers must never allocate more than 1 bio at a time * from this pool. Callers that need to allocate more than 1 bio must always * submit the previously allocated bio for IO before attempting to allocate * a new one. Failure to do so can cause deadlocks under memory pressure. * * Note that when running under generic_make_request() (i.e. any block * driver), bios are not submitted until after you return - see the code in * generic_make_request() that converts recursion into iteration, to prevent * stack overflows. * * This would normally mean allocating multiple bios under * generic_make_request() would be susceptible to deadlocks, but we have * deadlock avoidance code that resubmits any blocked bios from a rescuer * thread. * * However, we do not guarantee forward progress for allocations from other * mempools. Doing multiple allocations from the same mempool under * generic_make_request() should be avoided - instead, use bio_set's front_pad * for per bio allocations. * * RETURNS: * Pointer to new bio on success, NULL on failure. */ struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned int nr_iovecs, struct bio_set *bs) { gfp_t saved_gfp = gfp_mask; unsigned front_pad; unsigned inline_vecs; struct bio_vec *bvl = NULL; struct bio *bio; void *p; if (!bs) { if (nr_iovecs > UIO_MAXIOV) return NULL; p = kmalloc(sizeof(struct bio) + nr_iovecs * sizeof(struct bio_vec), gfp_mask); front_pad = 0; inline_vecs = nr_iovecs; } else { /* should not use nobvec bioset for nr_iovecs > 0 */ if (WARN_ON_ONCE(!mempool_initialized(&bs->bvec_pool) && nr_iovecs > 0)) return NULL; /* * generic_make_request() converts recursion to iteration; this * means if we're running beneath it, any bios we allocate and * submit will not be submitted (and thus freed) until after we * return. * * This exposes us to a potential deadlock if we allocate * multiple bios from the same bio_set() while running * underneath generic_make_request(). If we were to allocate * multiple bios (say a stacking block driver that was splitting * bios), we would deadlock if we exhausted the mempool's * reserve. * * We solve this, and guarantee forward progress, with a rescuer * workqueue per bio_set. If we go to allocate and there are * bios on current->bio_list, we first try the allocation * without __GFP_DIRECT_RECLAIM; if that fails, we punt those * bios we would be blocking to the rescuer workqueue before * we retry with the original gfp_flags. */ if (current->bio_list && (!bio_list_empty(¤t->bio_list[0]) || !bio_list_empty(¤t->bio_list[1])) && bs->rescue_workqueue) gfp_mask &= ~__GFP_DIRECT_RECLAIM; p = mempool_alloc(&bs->bio_pool, gfp_mask); if (!p && gfp_mask != saved_gfp) { punt_bios_to_rescuer(bs); gfp_mask = saved_gfp; p = mempool_alloc(&bs->bio_pool, gfp_mask); } front_pad = bs->front_pad; inline_vecs = BIO_INLINE_VECS; } if (unlikely(!p)) return NULL; bio = p + front_pad; bio_init(bio, NULL, 0); if (nr_iovecs > inline_vecs) { unsigned long idx = 0; bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, &bs->bvec_pool); if (!bvl && gfp_mask != saved_gfp) { punt_bios_to_rescuer(bs); gfp_mask = saved_gfp; bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, &bs->bvec_pool); } if (unlikely(!bvl)) goto err_free; bio->bi_flags |= idx << BVEC_POOL_OFFSET; } else if (nr_iovecs) { bvl = bio->bi_inline_vecs; } bio->bi_pool = bs; bio->bi_max_vecs = nr_iovecs; bio->bi_io_vec = bvl; return bio; err_free: mempool_free(p, &bs->bio_pool); return NULL; } EXPORT_SYMBOL(bio_alloc_bioset); void zero_fill_bio_iter(struct bio *bio, struct bvec_iter start) { unsigned long flags; struct bio_vec bv; struct bvec_iter iter; __bio_for_each_segment(bv, bio, iter, start) { char *data = bvec_kmap_irq(&bv, &flags); memset(data, 0, bv.bv_len); flush_dcache_page(bv.bv_page); bvec_kunmap_irq(data, &flags); } } EXPORT_SYMBOL(zero_fill_bio_iter); /** * bio_put - release a reference to a bio * @bio: bio to release reference to * * Description: * Put a reference to a &struct bio, either one you have gotten with * bio_alloc, bio_get or bio_clone_*. The last put of a bio will free it. **/ void bio_put(struct bio *bio) { if (!bio_flagged(bio, BIO_REFFED)) bio_free(bio); else { BIO_BUG_ON(!atomic_read(&bio->__bi_cnt)); /* * last put frees it */ if (atomic_dec_and_test(&bio->__bi_cnt)) bio_free(bio); } } EXPORT_SYMBOL(bio_put); inline int bio_phys_segments(struct request_queue *q, struct bio *bio) { if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) blk_recount_segments(q, bio); return bio->bi_phys_segments; } EXPORT_SYMBOL(bio_phys_segments); /** * __bio_clone_fast - clone a bio that shares the original bio's biovec * @bio: destination bio * @bio_src: bio to clone * * Clone a &bio. Caller will own the returned bio, but not * the actual data it points to. Reference count of returned * bio will be one. * * Caller must ensure that @bio_src is not freed before @bio. */ void __bio_clone_fast(struct bio *bio, struct bio *bio_src) { BUG_ON(bio->bi_pool && BVEC_POOL_IDX(bio)); /* * most users will be overriding ->bi_disk with a new target, * so we don't set nor calculate new physical/hw segment counts here */ bio->bi_disk = bio_src->bi_disk; bio->bi_partno = bio_src->bi_partno; bio_set_flag(bio, BIO_CLONED); if (bio_flagged(bio_src, BIO_THROTTLED)) bio_set_flag(bio, BIO_THROTTLED); bio->bi_opf = bio_src->bi_opf; bio->bi_ioprio = bio_src->bi_ioprio; bio->bi_write_hint = bio_src->bi_write_hint; bio->bi_iter = bio_src->bi_iter; bio->bi_io_vec = bio_src->bi_io_vec; bio_clone_blkcg_association(bio, bio_src); } EXPORT_SYMBOL(__bio_clone_fast); /** * bio_clone_fast - clone a bio that shares the original bio's biovec * @bio: bio to clone * @gfp_mask: allocation priority * @bs: bio_set to allocate from * * Like __bio_clone_fast, only also allocates the returned bio */ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) { struct bio *b; b = bio_alloc_bioset(gfp_mask, 0, bs); if (!b) return NULL; __bio_clone_fast(b, bio); if (bio_integrity(bio)) { int ret; ret = bio_integrity_clone(b, bio, gfp_mask); if (ret < 0) { bio_put(b); return NULL; } } return b; } EXPORT_SYMBOL(bio_clone_fast); /** * bio_add_pc_page - attempt to add page to bio * @q: the target queue * @bio: destination bio * @page: page to add * @len: vec entry length * @offset: vec entry offset * * Attempt to add a page to the bio_vec maplist. This can fail for a * number of reasons, such as the bio being full or target block device * limitations. The target block device must allow bio's up to PAGE_SIZE, * so it is always possible to add a single page to an empty bio. * * This should only be used by REQ_PC bios. */ int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page, unsigned int len, unsigned int offset) { int retried_segments = 0; struct bio_vec *bvec; /* * cloned bio must not modify vec list */ if (unlikely(bio_flagged(bio, BIO_CLONED))) return 0; if (((bio->bi_iter.bi_size + len) >> 9) > queue_max_hw_sectors(q)) return 0; /* * For filesystems with a blocksize smaller than the pagesize * we will often be called with the same page as last time and * a consecutive offset. Optimize this special case. */ if (bio->bi_vcnt > 0) { struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1]; if (page == prev->bv_page && offset == prev->bv_offset + prev->bv_len) { prev->bv_len += len; bio->bi_iter.bi_size += len; goto done; } /* * If the queue doesn't support SG gaps and adding this * offset would create a gap, disallow it. */ if (bvec_gap_to_prev(q, prev, offset)) return 0; } if (bio_full(bio)) return 0; /* * setup the new entry, we might clear it again later if we * cannot add the page */ bvec = &bio->bi_io_vec[bio->bi_vcnt]; bvec->bv_page = page; bvec->bv_len = len; bvec->bv_offset = offset; bio->bi_vcnt++; bio->bi_phys_segments++; bio->bi_iter.bi_size += len; /* * Perform a recount if the number of segments is greater * than queue_max_segments(q). */ while (bio->bi_phys_segments > queue_max_segments(q)) { if (retried_segments) goto failed; retried_segments = 1; blk_recount_segments(q, bio); } /* If we may be able to merge these biovecs, force a recount */ if (bio->bi_vcnt > 1 && biovec_phys_mergeable(q, bvec - 1, bvec)) bio_clear_flag(bio, BIO_SEG_VALID); done: return len; failed: bvec->bv_page = NULL; bvec->bv_len = 0; bvec->bv_offset = 0; bio->bi_vcnt--; bio->bi_iter.bi_size -= len; blk_recount_segments(q, bio); return 0; } EXPORT_SYMBOL(bio_add_pc_page); /** * __bio_try_merge_page - try appending data to an existing bvec. * @bio: destination bio * @page: page to add * @len: length of the data to add * @off: offset of the data in @page * * Try to add the data at @page + @off to the last bvec of @bio. This is a * a useful optimisation for file systems with a block size smaller than the * page size. * * Return %true on success or %false on failure. */ bool __bio_try_merge_page(struct bio *bio, struct page *page, unsigned int len, unsigned int off) { if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED))) return false; if (bio->bi_vcnt > 0) { struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1]; if (page == bv->bv_page && off == bv->bv_offset + bv->bv_len) { bv->bv_len += len; bio->bi_iter.bi_size += len; return true; } } return false; } EXPORT_SYMBOL_GPL(__bio_try_merge_page); /** * __bio_add_page - add page to a bio in a new segment * @bio: destination bio * @page: page to add * @len: length of the data to add * @off: offset of the data in @page * * Add the data at @page + @off to @bio as a new bvec. The caller must ensure * that @bio has space for another bvec. */ void __bio_add_page(struct bio *bio, struct page *page, unsigned int len, unsigned int off) { struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt]; WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)); WARN_ON_ONCE(bio_full(bio)); bv->bv_page = page; bv->bv_offset = off; bv->bv_len = len; bio->bi_iter.bi_size += len; bio->bi_vcnt++; } EXPORT_SYMBOL_GPL(__bio_add_page); /** * bio_add_page - attempt to add page to bio * @bio: destination bio * @page: page to add * @len: vec entry length * @offset: vec entry offset * * Attempt to add a page to the bio_vec maplist. This will only fail * if either bio->bi_vcnt == bio->bi_max_vecs or it's a cloned bio. */ int bio_add_page(struct bio *bio, struct page *page, unsigned int len, unsigned int offset) { if (!__bio_try_merge_page(bio, page, len, offset)) { if (bio_full(bio)) return 0; __bio_add_page(bio, page, len, offset); } return len; } EXPORT_SYMBOL(bio_add_page); #define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *)) /** * __bio_iov_iter_get_pages - pin user or kernel pages and add them to a bio * @bio: bio to add pages to * @iter: iov iterator describing the region to be mapped * * Pins pages from *iter and appends them to @bio's bvec array. The * pages will have to be released using put_page() when done. * For multi-segment *iter, this function only adds pages from the * the next non-empty segment of the iov iterator. */ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) { unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt; unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt; struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt; struct page **pages = (struct page **)bv; ssize_t size, left; unsigned len, i; size_t offset; /* * Move page array up in the allocated memory for the bio vecs as far as * possible so that we can start filling biovecs from the beginning * without overwriting the temporary page array. */ BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2); pages += entries_left * (PAGE_PTRS_PER_BVEC - 1); size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset); if (unlikely(size <= 0)) return size ? size : -EFAULT; for (left = size, i = 0; left > 0; left -= len, i++) { struct page *page = pages[i]; len = min_t(size_t, PAGE_SIZE - offset, left); if (WARN_ON_ONCE(bio_add_page(bio, page, len, offset) != len)) return -EINVAL; offset = 0; } iov_iter_advance(iter, size); return 0; } /** * bio_iov_iter_get_pages - pin user or kernel pages and add them to a bio * @bio: bio to add pages to * @iter: iov iterator describing the region to be mapped * * Pins pages from *iter and appends them to @bio's bvec array. The * pages will have to be released using put_page() when done. * The function tries, but does not guarantee, to pin as many pages as * fit into the bio, or are requested in *iter, whatever is smaller. * If MM encounters an error pinning the requested pages, it stops. * Error is returned only if 0 pages could be pinned. */ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) { unsigned short orig_vcnt = bio->bi_vcnt; do { int ret = __bio_iov_iter_get_pages(bio, iter); if (unlikely(ret)) return bio->bi_vcnt > orig_vcnt ? 0 : ret; } while (iov_iter_count(iter) && !bio_full(bio)); return 0; } EXPORT_SYMBOL_GPL(bio_iov_iter_get_pages); static void submit_bio_wait_endio(struct bio *bio) { complete(bio->bi_private); } /** * submit_bio_wait - submit a bio, and wait until it completes * @bio: The &struct bio which describes the I/O * * Simple wrapper around submit_bio(). Returns 0 on success, or the error from * bio_endio() on failure. * * WARNING: Unlike to how submit_bio() is usually used, this function does not * result in bio reference to be consumed. The caller must drop the reference * on his own. */ int submit_bio_wait(struct bio *bio) { DECLARE_COMPLETION_ONSTACK_MAP(done, bio->bi_disk->lockdep_map); bio->bi_private = &done; bio->bi_end_io = submit_bio_wait_endio; bio->bi_opf |= REQ_SYNC; submit_bio(bio); wait_for_completion_io(&done); return blk_status_to_errno(bio->bi_status); } EXPORT_SYMBOL(submit_bio_wait); /** * bio_advance - increment/complete a bio by some number of bytes * @bio: bio to advance * @bytes: number of bytes to complete * * This updates bi_sector, bi_size and bi_idx; if the number of bytes to * complete doesn't align with a bvec boundary, then bv_len and bv_offset will * be updated on the last bvec as well. * * @bio will then represent the remaining, uncompleted portion of the io. */ void bio_advance(struct bio *bio, unsigned bytes) { if (bio_integrity(bio)) bio_integrity_advance(bio, bytes); bio_advance_iter(bio, &bio->bi_iter, bytes); } EXPORT_SYMBOL(bio_advance); void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter, struct bio *src, struct bvec_iter *src_iter) { struct bio_vec src_bv, dst_bv; void *src_p, *dst_p; unsigned bytes; while (src_iter->bi_size && dst_iter->bi_size) { src_bv = bio_iter_iovec(src, *src_iter); dst_bv = bio_iter_iovec(dst, *dst_iter); bytes = min(src_bv.bv_len, dst_bv.bv_len); src_p = kmap_atomic(src_bv.bv_page); dst_p = kmap_atomic(dst_bv.bv_page); memcpy(dst_p + dst_bv.bv_offset, src_p + src_bv.bv_offset, bytes); kunmap_atomic(dst_p); kunmap_atomic(src_p); flush_dcache_page(dst_bv.bv_page); bio_advance_iter(src, src_iter, bytes); bio_advance_iter(dst, dst_iter, bytes); } } EXPORT_SYMBOL(bio_copy_data_iter); /** * bio_copy_data - copy contents of data buffers from one bio to another * @src: source bio * @dst: destination bio * * Stops when it reaches the end of either @src or @dst - that is, copies * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios). */ void bio_copy_data(struct bio *dst, struct bio *src) { struct bvec_iter src_iter = src->bi_iter; struct bvec_iter dst_iter = dst->bi_iter; bio_copy_data_iter(dst, &dst_iter, src, &src_iter); } EXPORT_SYMBOL(bio_copy_data); /** * bio_list_copy_data - copy contents of data buffers from one chain of bios to * another * @src: source bio list * @dst: destination bio list * * Stops when it reaches the end of either the @src list or @dst list - that is, * copies min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of * bios). */ void bio_list_copy_data(struct bio *dst, struct bio *src) { struct bvec_iter src_iter = src->bi_iter; struct bvec_iter dst_iter = dst->bi_iter; while (1) { if (!src_iter.bi_size) { src = src->bi_next; if (!src) break; src_iter = src->bi_iter; } if (!dst_iter.bi_size) { dst = dst->bi_next; if (!dst) break; dst_iter = dst->bi_iter; } bio_copy_data_iter(dst, &dst_iter, src, &src_iter); } } EXPORT_SYMBOL(bio_list_copy_data); struct bio_map_data { int is_our_pages; struct iov_iter iter; struct iovec iov[]; }; static struct bio_map_data *bio_alloc_map_data(struct iov_iter *data, gfp_t gfp_mask) { struct bio_map_data *bmd; if (data->nr_segs > UIO_MAXIOV) return NULL; bmd = kmalloc(sizeof(struct bio_map_data) + sizeof(struct iovec) * data->nr_segs, gfp_mask); if (!bmd) return NULL; memcpy(bmd->iov, data->iov, sizeof(struct iovec) * data->nr_segs); bmd->iter = *data; bmd->iter.iov = bmd->iov; return bmd; } /** * bio_copy_from_iter - copy all pages from iov_iter to bio * @bio: The &struct bio which describes the I/O as destination * @iter: iov_iter as source * * Copy all pages from iov_iter to bio. * Returns 0 on success, or error on failure. */ static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter) { int i; struct bio_vec *bvec; bio_for_each_segment_all(bvec, bio, i) { ssize_t ret; ret = copy_page_from_iter(bvec->bv_page, bvec->bv_offset, bvec->bv_len, iter); if (!iov_iter_count(iter)) break; if (ret < bvec->bv_len) return -EFAULT; } return 0; } /** * bio_copy_to_iter - copy all pages from bio to iov_iter * @bio: The &struct bio which describes the I/O as source * @iter: iov_iter as destination * * Copy all pages from bio to iov_iter. * Returns 0 on success, or error on failure. */ static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter) { int i; struct bio_vec *bvec; bio_for_each_segment_all(bvec, bio, i) { ssize_t ret; ret = copy_page_to_iter(bvec->bv_page, bvec->bv_offset, bvec->bv_len, &iter); if (!iov_iter_count(&iter)) break; if (ret < bvec->bv_len) return -EFAULT; } return 0; } void bio_free_pages(struct bio *bio) { struct bio_vec *bvec; int i; bio_for_each_segment_all(bvec, bio, i) __free_page(bvec->bv_page); } EXPORT_SYMBOL(bio_free_pages); /** * bio_uncopy_user - finish previously mapped bio * @bio: bio being terminated * * Free pages allocated from bio_copy_user_iov() and write back data * to user space in case of a read. */ int bio_uncopy_user(struct bio *bio) { struct bio_map_data *bmd = bio->bi_private; int ret = 0; if (!bio_flagged(bio, BIO_NULL_MAPPED)) { /* * if we're in a workqueue, the request is orphaned, so * don't copy into a random user address space, just free * and return -EINTR so user space doesn't expect any data. */ if (!current->mm) ret = -EINTR; else if (bio_data_dir(bio) == READ) ret = bio_copy_to_iter(bio, bmd->iter); if (bmd->is_our_pages) bio_free_pages(bio); } kfree(bmd); bio_put(bio); return ret; } /** * bio_copy_user_iov - copy user data to bio * @q: destination block queue * @map_data: pointer to the rq_map_data holding pages (if necessary) * @iter: iovec iterator * @gfp_mask: memory allocation flags * * Prepares and returns a bio for indirect user io, bouncing data * to/from kernel pages as necessary. Must be paired with * call bio_uncopy_user() on io completion. */ struct bio *bio_copy_user_iov(struct request_queue *q, struct rq_map_data *map_data, struct iov_iter *iter, gfp_t gfp_mask) { struct bio_map_data *bmd; struct page *page; struct bio *bio; int i = 0, ret; int nr_pages; unsigned int len = iter->count; unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0; bmd = bio_alloc_map_data(iter, gfp_mask); if (!bmd) return ERR_PTR(-ENOMEM); /* * We need to do a deep copy of the iov_iter including the iovecs. * The caller provided iov might point to an on-stack or otherwise * shortlived one. */ bmd->is_our_pages = map_data ? 0 : 1; nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE); if (nr_pages > BIO_MAX_PAGES) nr_pages = BIO_MAX_PAGES; ret = -ENOMEM; bio = bio_kmalloc(gfp_mask, nr_pages); if (!bio) goto out_bmd; ret = 0; if (map_data) { nr_pages = 1 << map_data->page_order; i = map_data->offset / PAGE_SIZE; } while (len) { unsigned int bytes = PAGE_SIZE; bytes -= offset; if (bytes > len) bytes = len; if (map_data) { if (i == map_data->nr_entries * nr_pages) { ret = -ENOMEM; break; } page = map_data->pages[i / nr_pages]; page += (i % nr_pages); i++; } else { page = alloc_page(q->bounce_gfp | gfp_mask); if (!page) { ret = -ENOMEM; break; } } if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) break; len -= bytes; offset = 0; } if (ret) goto cleanup; if (map_data) map_data->offset += bio->bi_iter.bi_size; /* * success */ if ((iov_iter_rw(iter) == WRITE && (!map_data || !map_data->null_mapped)) || (map_data && map_data->from_user)) { ret = bio_copy_from_iter(bio, iter); if (ret) goto cleanup; } else { if (bmd->is_our_pages) zero_fill_bio(bio); iov_iter_advance(iter, bio->bi_iter.bi_size); } bio->bi_private = bmd; if (map_data && map_data->null_mapped) bio_set_flag(bio, BIO_NULL_MAPPED); return bio; cleanup: if (!map_data) bio_free_pages(bio); bio_put(bio); out_bmd: kfree(bmd); return ERR_PTR(ret); } /** * bio_map_user_iov - map user iovec into bio * @q: the struct request_queue for the bio * @iter: iovec iterator * @gfp_mask: memory allocation flags * * Map the user space address into a bio suitable for io to a block * device. Returns an error pointer in case of error. */ struct bio *bio_map_user_iov(struct request_queue *q, struct iov_iter *iter, gfp_t gfp_mask) { int j; struct bio *bio; int ret; struct bio_vec *bvec; if (!iov_iter_count(iter)) return ERR_PTR(-EINVAL); bio = bio_kmalloc(gfp_mask, iov_iter_npages(iter, BIO_MAX_PAGES)); if (!bio) return ERR_PTR(-ENOMEM); while (iov_iter_count(iter)) { struct page **pages; ssize_t bytes; size_t offs, added = 0; int npages; bytes = iov_iter_get_pages_alloc(iter, &pages, LONG_MAX, &offs); if (unlikely(bytes <= 0)) { ret = bytes ? bytes : -EFAULT; goto out_unmap; } npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE); if (unlikely(offs & queue_dma_alignment(q))) { ret = -EINVAL; j = 0; } else { for (j = 0; j < npages; j++) { struct page *page = pages[j]; unsigned int n = PAGE_SIZE - offs; unsigned short prev_bi_vcnt = bio->bi_vcnt; if (n > bytes) n = bytes; if (!bio_add_pc_page(q, bio, page, n, offs)) break; /* * check if vector was merged with previous * drop page reference if needed */ if (bio->bi_vcnt == prev_bi_vcnt) put_page(page); added += n; bytes -= n; offs = 0; } iov_iter_advance(iter, added); } /* * release the pages we didn't map into the bio, if any */ while (j < npages) put_page(pages[j++]); kvfree(pages); /* couldn't stuff something into bio? */ if (bytes) break; } bio_set_flag(bio, BIO_USER_MAPPED); /* * subtle -- if bio_map_user_iov() ended up bouncing a bio, * it would normally disappear when its bi_end_io is run. * however, we need it for the unmap, so grab an extra * reference to it */ bio_get(bio); return bio; out_unmap: bio_for_each_segment_all(bvec, bio, j) { put_page(bvec->bv_page); } bio_put(bio); return ERR_PTR(ret); } static void __bio_unmap_user(struct bio *bio) { struct bio_vec *bvec; int i; /* * make sure we dirty pages we wrote to */ bio_for_each_segment_all(bvec, bio, i) { if (bio_data_dir(bio) == READ) set_page_dirty_lock(bvec->bv_page); put_page(bvec->bv_page); } bio_put(bio); } /** * bio_unmap_user - unmap a bio * @bio: the bio being unmapped * * Unmap a bio previously mapped by bio_map_user_iov(). Must be called from * process context. * * bio_unmap_user() may sleep. */ void bio_unmap_user(struct bio *bio) { __bio_unmap_user(bio); bio_put(bio); } static void bio_map_kern_endio(struct bio *bio) { bio_put(bio); } /** * bio_map_kern - map kernel address into bio * @q: the struct request_queue for the bio * @data: pointer to buffer to map * @len: length in bytes * @gfp_mask: allocation flags for bio allocation * * Map the kernel address into a bio suitable for io to a block * device. Returns an error pointer in case of error. */ struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len, gfp_t gfp_mask) { unsigned long kaddr = (unsigned long)data; unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; unsigned long start = kaddr >> PAGE_SHIFT; const int nr_pages = end - start; int offset, i; struct bio *bio; bio = bio_kmalloc(gfp_mask, nr_pages); if (!bio) return ERR_PTR(-ENOMEM); offset = offset_in_page(kaddr); for (i = 0; i < nr_pages; i++) { unsigned int bytes = PAGE_SIZE - offset; if (len <= 0) break; if (bytes > len) bytes = len; if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, offset) < bytes) { /* we don't support partial mappings */ bio_put(bio); return ERR_PTR(-EINVAL); } data += bytes; len -= bytes; offset = 0; } bio->bi_end_io = bio_map_kern_endio; return bio; } EXPORT_SYMBOL(bio_map_kern); static void bio_copy_kern_endio(struct bio *bio) { bio_free_pages(bio); bio_put(bio); } static void bio_copy_kern_endio_read(struct bio *bio) { char *p = bio->bi_private; struct bio_vec *bvec; int i; bio_for_each_segment_all(bvec, bio, i) { memcpy(p, page_address(bvec->bv_page), bvec->bv_len); p += bvec->bv_len; } bio_copy_kern_endio(bio); } /** * bio_copy_kern - copy kernel address into bio * @q: the struct request_queue for the bio * @data: pointer to buffer to copy * @len: length in bytes * @gfp_mask: allocation flags for bio and page allocation * @reading: data direction is READ * * copy the kernel address into a bio suitable for io to a block * device. Returns an error pointer in case of error. */ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, gfp_t gfp_mask, int reading) { unsigned long kaddr = (unsigned long)data; unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; unsigned long start = kaddr >> PAGE_SHIFT; struct bio *bio; void *p = data; int nr_pages = 0; /* * Overflow, abort */ if (end < start) return ERR_PTR(-EINVAL); nr_pages = end - start; bio = bio_kmalloc(gfp_mask, nr_pages); if (!bio) return ERR_PTR(-ENOMEM); while (len) { struct page *page; unsigned int bytes = PAGE_SIZE; if (bytes > len) bytes = len; page = alloc_page(q->bounce_gfp | gfp_mask); if (!page) goto cleanup; if (!reading) memcpy(page_address(page), p, bytes); if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) break; len -= bytes; p += bytes; } if (reading) { bio->bi_end_io = bio_copy_kern_endio_read; bio->bi_private = data; } else { bio->bi_end_io = bio_copy_kern_endio; } return bio; cleanup: bio_free_pages(bio); bio_put(bio); return ERR_PTR(-ENOMEM); } /* * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions * for performing direct-IO in BIOs. * * The problem is that we cannot run set_page_dirty() from interrupt context * because the required locks are not interrupt-safe. So what we can do is to * mark the pages dirty _before_ performing IO. And in interrupt context, * check that the pages are still dirty. If so, fine. If not, redirty them * in process context. * * We special-case compound pages here: normally this means reads into hugetlb * pages. The logic in here doesn't really work right for compound pages * because the VM does not uniformly chase down the head page in all cases. * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't * handle them at all. So we skip compound pages here at an early stage. * * Note that this code is very hard to test under normal circumstances because * direct-io pins the pages with get_user_pages(). This makes * is_page_cache_freeable return false, and the VM will not clean the pages. * But other code (eg, flusher threads) could clean the pages if they are mapped * pagecache. * * Simply disabling the call to bio_set_pages_dirty() is a good way to test the * deferred bio dirtying paths. */ /* * bio_set_pages_dirty() will mark all the bio's pages as dirty. */ void bio_set_pages_dirty(struct bio *bio) { struct bio_vec *bvec; int i; bio_for_each_segment_all(bvec, bio, i) { if (!PageCompound(bvec->bv_page)) set_page_dirty_lock(bvec->bv_page); } } EXPORT_SYMBOL_GPL(bio_set_pages_dirty); static void bio_release_pages(struct bio *bio) { struct bio_vec *bvec; int i; bio_for_each_segment_all(bvec, bio, i) put_page(bvec->bv_page); } /* * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. * If they are, then fine. If, however, some pages are clean then they must * have been written out during the direct-IO read. So we take another ref on * the BIO and re-dirty the pages in process context. * * It is expected that bio_check_pages_dirty() will wholly own the BIO from * here on. It will run one put_page() against each page and will run one * bio_put() against the BIO. */ static void bio_dirty_fn(struct work_struct *work); static DECLARE_WORK(bio_dirty_work, bio_dirty_fn); static DEFINE_SPINLOCK(bio_dirty_lock); static struct bio *bio_dirty_list; /* * This runs in process context */ static void bio_dirty_fn(struct work_struct *work) { struct bio *bio, *next; spin_lock_irq(&bio_dirty_lock); next = bio_dirty_list; bio_dirty_list = NULL; spin_unlock_irq(&bio_dirty_lock); while ((bio = next) != NULL) { next = bio->bi_private; bio_set_pages_dirty(bio); bio_release_pages(bio); bio_put(bio); } } void bio_check_pages_dirty(struct bio *bio) { struct bio_vec *bvec; unsigned long flags; int i; bio_for_each_segment_all(bvec, bio, i) { if (!PageDirty(bvec->bv_page) && !PageCompound(bvec->bv_page)) goto defer; } bio_release_pages(bio); bio_put(bio); return; defer: spin_lock_irqsave(&bio_dirty_lock, flags); bio->bi_private = bio_dirty_list; bio_dirty_list = bio; spin_unlock_irqrestore(&bio_dirty_lock, flags); schedule_work(&bio_dirty_work); } EXPORT_SYMBOL_GPL(bio_check_pages_dirty); void generic_start_io_acct(struct request_queue *q, int op, unsigned long sectors, struct hd_struct *part) { const int sgrp = op_stat_group(op); int cpu = part_stat_lock(); part_round_stats(q, cpu, part); part_stat_inc(cpu, part, ios[sgrp]); part_stat_add(cpu, part, sectors[sgrp], sectors); part_inc_in_flight(q, part, op_is_write(op)); part_stat_unlock(); } EXPORT_SYMBOL(generic_start_io_acct); void generic_end_io_acct(struct request_queue *q, int req_op, struct hd_struct *part, unsigned long start_time) { unsigned long duration = jiffies - start_time; const int sgrp = op_stat_group(req_op); int cpu = part_stat_lock(); part_stat_add(cpu, part, nsecs[sgrp], jiffies_to_nsecs(duration)); part_round_stats(q, cpu, part); part_dec_in_flight(q, part, op_is_write(req_op)); part_stat_unlock(); } EXPORT_SYMBOL(generic_end_io_acct); #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE void bio_flush_dcache_pages(struct bio *bi) { struct bio_vec bvec; struct bvec_iter iter; bio_for_each_segment(bvec, bi, iter) flush_dcache_page(bvec.bv_page); } EXPORT_SYMBOL(bio_flush_dcache_pages); #endif static inline bool bio_remaining_done(struct bio *bio) { /* * If we're not chaining, then ->__bi_remaining is always 1 and * we always end io on the first invocation. */ if (!bio_flagged(bio, BIO_CHAIN)) return true; BUG_ON(atomic_read(&bio->__bi_remaining) <= 0); if (atomic_dec_and_test(&bio->__bi_remaining)) { bio_clear_flag(bio, BIO_CHAIN); return true; } return false; } /** * bio_endio - end I/O on a bio * @bio: bio * * Description: * bio_endio() will end I/O on the whole bio. bio_endio() is the preferred * way to end I/O on a bio. No one should call bi_end_io() directly on a * bio unless they own it and thus know that it has an end_io function. * * bio_endio() can be called several times on a bio that has been chained * using bio_chain(). The ->bi_end_io() function will only be called the * last time. At this point the BLK_TA_COMPLETE tracing event will be * generated if BIO_TRACE_COMPLETION is set. **/ void bio_endio(struct bio *bio) { again: if (!bio_remaining_done(bio)) return; if (!bio_integrity_endio(bio)) return; if (bio->bi_disk) rq_qos_done_bio(bio->bi_disk->queue, bio); /* * Need to have a real endio function for chained bios, otherwise * various corner cases will break (like stacking block devices that * save/restore bi_end_io) - however, we want to avoid unbounded * recursion and blowing the stack. Tail call optimization would * handle this, but compiling with frame pointers also disables * gcc's sibling call optimization. */ if (bio->bi_end_io == bio_chain_endio) { bio = __bio_chain_endio(bio); goto again; } if (bio->bi_disk && bio_flagged(bio, BIO_TRACE_COMPLETION)) { trace_block_bio_complete(bio->bi_disk->queue, bio, blk_status_to_errno(bio->bi_status)); bio_clear_flag(bio, BIO_TRACE_COMPLETION); } blk_throtl_bio_endio(bio); /* release cgroup info */ bio_uninit(bio); if (bio->bi_end_io) bio->bi_end_io(bio); } EXPORT_SYMBOL(bio_endio); /** * bio_split - split a bio * @bio: bio to split * @sectors: number of sectors to split from the front of @bio * @gfp: gfp mask * @bs: bio set to allocate from * * Allocates and returns a new bio which represents @sectors from the start of * @bio, and updates @bio to represent the remaining sectors. * * Unless this is a discard request the newly allocated bio will point * to @bio's bi_io_vec; it is the caller's responsibility to ensure that * @bio is not freed before the split. */ struct bio *bio_split(struct bio *bio, int sectors, gfp_t gfp, struct bio_set *bs) { struct bio *split; BUG_ON(sectors <= 0); BUG_ON(sectors >= bio_sectors(bio)); split = bio_clone_fast(bio, gfp, bs); if (!split) return NULL; split->bi_iter.bi_size = sectors << 9; if (bio_integrity(split)) bio_integrity_trim(split); bio_advance(bio, split->bi_iter.bi_size); if (bio_flagged(bio, BIO_TRACE_COMPLETION)) bio_set_flag(split, BIO_TRACE_COMPLETION); return split; } EXPORT_SYMBOL(bio_split); /** * bio_trim - trim a bio * @bio: bio to trim * @offset: number of sectors to trim from the front of @bio * @size: size we want to trim @bio to, in sectors */ void bio_trim(struct bio *bio, int offset, int size) { /* 'bio' is a cloned bio which we need to trim to match * the given offset and size. */ size <<= 9; if (offset == 0 && size == bio->bi_iter.bi_size) return; bio_clear_flag(bio, BIO_SEG_VALID); bio_advance(bio, offset << 9); bio->bi_iter.bi_size = size; if (bio_integrity(bio)) bio_integrity_trim(bio); } EXPORT_SYMBOL_GPL(bio_trim); /* * create memory pools for biovec's in a bio_set. * use the global biovec slabs created for general use. */ int biovec_init_pool(mempool_t *pool, int pool_entries) { struct biovec_slab *bp = bvec_slabs + BVEC_POOL_MAX; return mempool_init_slab_pool(pool, pool_entries, bp->slab); } /* * bioset_exit - exit a bioset initialized with bioset_init() * * May be called on a zeroed but uninitialized bioset (i.e. allocated with * kzalloc()). */ void bioset_exit(struct bio_set *bs) { if (bs->rescue_workqueue) destroy_workqueue(bs->rescue_workqueue); bs->rescue_workqueue = NULL; mempool_exit(&bs->bio_pool); mempool_exit(&bs->bvec_pool); bioset_integrity_free(bs); if (bs->bio_slab) bio_put_slab(bs); bs->bio_slab = NULL; } EXPORT_SYMBOL(bioset_exit); /** * bioset_init - Initialize a bio_set * @bs: pool to initialize * @pool_size: Number of bio and bio_vecs to cache in the mempool * @front_pad: Number of bytes to allocate in front of the returned bio * @flags: Flags to modify behavior, currently %BIOSET_NEED_BVECS * and %BIOSET_NEED_RESCUER * * Description: * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller * to ask for a number of bytes to be allocated in front of the bio. * Front pad allocation is useful for embedding the bio inside * another structure, to avoid allocating extra data to go with the bio. * Note that the bio must be embedded at the END of that structure always, * or things will break badly. * If %BIOSET_NEED_BVECS is set in @flags, a separate pool will be allocated * for allocating iovecs. This pool is not needed e.g. for bio_clone_fast(). * If %BIOSET_NEED_RESCUER is set, a workqueue is created which can be used to * dispatch queued requests when the mempool runs out of space. * */ int bioset_init(struct bio_set *bs, unsigned int pool_size, unsigned int front_pad, int flags) { unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec); bs->front_pad = front_pad; spin_lock_init(&bs->rescue_lock); bio_list_init(&bs->rescue_list); INIT_WORK(&bs->rescue_work, bio_alloc_rescue); bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad); if (!bs->bio_slab) return -ENOMEM; if (mempool_init_slab_pool(&bs->bio_pool, pool_size, bs->bio_slab)) goto bad; if ((flags & BIOSET_NEED_BVECS) && biovec_init_pool(&bs->bvec_pool, pool_size)) goto bad; if (!(flags & BIOSET_NEED_RESCUER)) return 0; bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0); if (!bs->rescue_workqueue) goto bad; return 0; bad: bioset_exit(bs); return -ENOMEM; } EXPORT_SYMBOL(bioset_init); /* * Initialize and setup a new bio_set, based on the settings from * another bio_set. */ int bioset_init_from_src(struct bio_set *bs, struct bio_set *src) { int flags; flags = 0; if (src->bvec_pool.min_nr) flags |= BIOSET_NEED_BVECS; if (src->rescue_workqueue) flags |= BIOSET_NEED_RESCUER; return bioset_init(bs, src->bio_pool.min_nr, src->front_pad, flags); } EXPORT_SYMBOL(bioset_init_from_src); #ifdef CONFIG_BLK_CGROUP #ifdef CONFIG_MEMCG /** * bio_associate_blkcg_from_page - associate a bio with the page's blkcg * @bio: target bio * @page: the page to lookup the blkcg from * * Associate @bio with the blkcg from @page's owning memcg. This works like * every other associate function wrt references. */ int bio_associate_blkcg_from_page(struct bio *bio, struct page *page) { struct cgroup_subsys_state *blkcg_css; if (unlikely(bio->bi_css)) return -EBUSY; if (!page->mem_cgroup) return 0; blkcg_css = cgroup_get_e_css(page->mem_cgroup->css.cgroup, &io_cgrp_subsys); bio->bi_css = blkcg_css; return 0; } #endif /* CONFIG_MEMCG */ /** * bio_associate_blkcg - associate a bio with the specified blkcg * @bio: target bio * @blkcg_css: css of the blkcg to associate * * Associate @bio with the blkcg specified by @blkcg_css. Block layer will * treat @bio as if it were issued by a task which belongs to the blkcg. * * This function takes an extra reference of @blkcg_css which will be put * when @bio is released. The caller must own @bio and is responsible for * synchronizing calls to this function. */ int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) { if (unlikely(bio->bi_css)) return -EBUSY; css_get(blkcg_css); bio->bi_css = blkcg_css; return 0; } EXPORT_SYMBOL_GPL(bio_associate_blkcg); /** * bio_associate_blkg - associate a bio with the specified blkg * @bio: target bio * @blkg: the blkg to associate * * Associate @bio with the blkg specified by @blkg. This is the queue specific * blkcg information associated with the @bio, a reference will be taken on the * @blkg and will be freed when the bio is freed. */ int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg) { if (unlikely(bio->bi_blkg)) return -EBUSY; if (!blkg_try_get(blkg)) return -ENODEV; bio->bi_blkg = blkg; return 0; } /** * bio_disassociate_task - undo bio_associate_current() * @bio: target bio */ void bio_disassociate_task(struct bio *bio) { if (bio->bi_ioc) { put_io_context(bio->bi_ioc); bio->bi_ioc = NULL; } if (bio->bi_css) { css_put(bio->bi_css); bio->bi_css = NULL; } if (bio->bi_blkg) { blkg_put(bio->bi_blkg); bio->bi_blkg = NULL; } } /** * bio_clone_blkcg_association - clone blkcg association from src to dst bio * @dst: destination bio * @src: source bio */ void bio_clone_blkcg_association(struct bio *dst, struct bio *src) { if (src->bi_css) WARN_ON(bio_associate_blkcg(dst, src->bi_css)); } EXPORT_SYMBOL_GPL(bio_clone_blkcg_association); #endif /* CONFIG_BLK_CGROUP */ static void __init biovec_init_slabs(void) { int i; for (i = 0; i < BVEC_POOL_NR; i++) { int size; struct biovec_slab *bvs = bvec_slabs + i; if (bvs->nr_vecs <= BIO_INLINE_VECS) { bvs->slab = NULL; continue; } size = bvs->nr_vecs * sizeof(struct bio_vec); bvs->slab = kmem_cache_create(bvs->name, size, 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); } } static int __init init_bio(void) { bio_slab_max = 2; bio_slab_nr = 0; bio_slabs = kcalloc(bio_slab_max, sizeof(struct bio_slab), GFP_KERNEL); if (!bio_slabs) panic("bio: can't allocate bios\n"); bio_integrity_init(); biovec_init_slabs(); if (bioset_init(&fs_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS)) panic("bio: can't allocate bios\n"); if (bioset_integrity_create(&fs_bio_set, BIO_POOL_SIZE)) panic("bio: can't create integrity pool\n"); return 0; } subsys_initcall(init_bio);
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