18c16567dSChristoph Hellwig // SPDX-License-Identifier: GPL-2.0 2f9c78b2bSJens Axboe /* 3f9c78b2bSJens Axboe * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk> 4f9c78b2bSJens Axboe */ 5f9c78b2bSJens Axboe #include <linux/mm.h> 6f9c78b2bSJens Axboe #include <linux/swap.h> 7f9c78b2bSJens Axboe #include <linux/bio.h> 8f9c78b2bSJens Axboe #include <linux/blkdev.h> 9f9c78b2bSJens Axboe #include <linux/uio.h> 10f9c78b2bSJens Axboe #include <linux/iocontext.h> 11f9c78b2bSJens Axboe #include <linux/slab.h> 12f9c78b2bSJens Axboe #include <linux/init.h> 13f9c78b2bSJens Axboe #include <linux/kernel.h> 14f9c78b2bSJens Axboe #include <linux/export.h> 15f9c78b2bSJens Axboe #include <linux/mempool.h> 16f9c78b2bSJens Axboe #include <linux/workqueue.h> 17f9c78b2bSJens Axboe #include <linux/cgroup.h> 1808e18eabSJosef Bacik #include <linux/blk-cgroup.h> 19b4c5875dSDamien Le Moal #include <linux/highmem.h> 20de6a78b6SMing Lei #include <linux/sched/sysctl.h> 21a892c8d5SSatya Tangirala #include <linux/blk-crypto.h> 2249d1ec85SMing Lei #include <linux/xarray.h> 23f9c78b2bSJens Axboe 24f9c78b2bSJens Axboe #include <trace/events/block.h> 259e234eeaSShaohua Li #include "blk.h" 2667b42d0bSJosef Bacik #include "blk-rq-qos.h" 27f9c78b2bSJens Axboe 28be4d234dSJens Axboe struct bio_alloc_cache { 29be4d234dSJens Axboe struct bio_list free_list; 30be4d234dSJens Axboe unsigned int nr; 31be4d234dSJens Axboe }; 32be4d234dSJens Axboe 33de76fd89SChristoph Hellwig static struct biovec_slab { 346ac0b715SChristoph Hellwig int nr_vecs; 356ac0b715SChristoph Hellwig char *name; 366ac0b715SChristoph Hellwig struct kmem_cache *slab; 37de76fd89SChristoph Hellwig } bvec_slabs[] __read_mostly = { 38de76fd89SChristoph Hellwig { .nr_vecs = 16, .name = "biovec-16" }, 39de76fd89SChristoph Hellwig { .nr_vecs = 64, .name = "biovec-64" }, 40de76fd89SChristoph Hellwig { .nr_vecs = 128, .name = "biovec-128" }, 41a8affc03SChristoph Hellwig { .nr_vecs = BIO_MAX_VECS, .name = "biovec-max" }, 42f9c78b2bSJens Axboe }; 436ac0b715SChristoph Hellwig 447a800a20SChristoph Hellwig static struct biovec_slab *biovec_slab(unsigned short nr_vecs) 457a800a20SChristoph Hellwig { 467a800a20SChristoph Hellwig switch (nr_vecs) { 477a800a20SChristoph Hellwig /* smaller bios use inline vecs */ 487a800a20SChristoph Hellwig case 5 ... 16: 497a800a20SChristoph Hellwig return &bvec_slabs[0]; 507a800a20SChristoph Hellwig case 17 ... 64: 517a800a20SChristoph Hellwig return &bvec_slabs[1]; 527a800a20SChristoph Hellwig case 65 ... 128: 537a800a20SChristoph Hellwig return &bvec_slabs[2]; 54a8affc03SChristoph Hellwig case 129 ... BIO_MAX_VECS: 557a800a20SChristoph Hellwig return &bvec_slabs[3]; 567a800a20SChristoph Hellwig default: 577a800a20SChristoph Hellwig BUG(); 587a800a20SChristoph Hellwig return NULL; 597a800a20SChristoph Hellwig } 607a800a20SChristoph Hellwig } 61f9c78b2bSJens Axboe 62f9c78b2bSJens Axboe /* 63f9c78b2bSJens Axboe * fs_bio_set is the bio_set containing bio and iovec memory pools used by 64f9c78b2bSJens Axboe * IO code that does not need private memory pools. 65f9c78b2bSJens Axboe */ 66f4f8154aSKent Overstreet struct bio_set fs_bio_set; 67f9c78b2bSJens Axboe EXPORT_SYMBOL(fs_bio_set); 68f9c78b2bSJens Axboe 69f9c78b2bSJens Axboe /* 70f9c78b2bSJens Axboe * Our slab pool management 71f9c78b2bSJens Axboe */ 72f9c78b2bSJens Axboe struct bio_slab { 73f9c78b2bSJens Axboe struct kmem_cache *slab; 74f9c78b2bSJens Axboe unsigned int slab_ref; 75f9c78b2bSJens Axboe unsigned int slab_size; 76f9c78b2bSJens Axboe char name[8]; 77f9c78b2bSJens Axboe }; 78f9c78b2bSJens Axboe static DEFINE_MUTEX(bio_slab_lock); 7949d1ec85SMing Lei static DEFINE_XARRAY(bio_slabs); 80f9c78b2bSJens Axboe 8149d1ec85SMing Lei static struct bio_slab *create_bio_slab(unsigned int size) 82f9c78b2bSJens Axboe { 8349d1ec85SMing Lei struct bio_slab *bslab = kzalloc(sizeof(*bslab), GFP_KERNEL); 8449d1ec85SMing Lei 8549d1ec85SMing Lei if (!bslab) 8649d1ec85SMing Lei return NULL; 8749d1ec85SMing Lei 8849d1ec85SMing Lei snprintf(bslab->name, sizeof(bslab->name), "bio-%d", size); 8949d1ec85SMing Lei bslab->slab = kmem_cache_create(bslab->name, size, 9049d1ec85SMing Lei ARCH_KMALLOC_MINALIGN, SLAB_HWCACHE_ALIGN, NULL); 9149d1ec85SMing Lei if (!bslab->slab) 9249d1ec85SMing Lei goto fail_alloc_slab; 9349d1ec85SMing Lei 9449d1ec85SMing Lei bslab->slab_ref = 1; 9549d1ec85SMing Lei bslab->slab_size = size; 9649d1ec85SMing Lei 9749d1ec85SMing Lei if (!xa_err(xa_store(&bio_slabs, size, bslab, GFP_KERNEL))) 9849d1ec85SMing Lei return bslab; 9949d1ec85SMing Lei 10049d1ec85SMing Lei kmem_cache_destroy(bslab->slab); 10149d1ec85SMing Lei 10249d1ec85SMing Lei fail_alloc_slab: 10349d1ec85SMing Lei kfree(bslab); 10449d1ec85SMing Lei return NULL; 10549d1ec85SMing Lei } 10649d1ec85SMing Lei 10749d1ec85SMing Lei static inline unsigned int bs_bio_slab_size(struct bio_set *bs) 10849d1ec85SMing Lei { 1099f180e31SMing Lei return bs->front_pad + sizeof(struct bio) + bs->back_pad; 11049d1ec85SMing Lei } 11149d1ec85SMing Lei 11249d1ec85SMing Lei static struct kmem_cache *bio_find_or_create_slab(struct bio_set *bs) 11349d1ec85SMing Lei { 11449d1ec85SMing Lei unsigned int size = bs_bio_slab_size(bs); 11549d1ec85SMing Lei struct bio_slab *bslab; 116f9c78b2bSJens Axboe 117f9c78b2bSJens Axboe mutex_lock(&bio_slab_lock); 11849d1ec85SMing Lei bslab = xa_load(&bio_slabs, size); 11949d1ec85SMing Lei if (bslab) 120f9c78b2bSJens Axboe bslab->slab_ref++; 12149d1ec85SMing Lei else 12249d1ec85SMing Lei bslab = create_bio_slab(size); 123f9c78b2bSJens Axboe mutex_unlock(&bio_slab_lock); 12449d1ec85SMing Lei 12549d1ec85SMing Lei if (bslab) 12649d1ec85SMing Lei return bslab->slab; 12749d1ec85SMing Lei return NULL; 128f9c78b2bSJens Axboe } 129f9c78b2bSJens Axboe 130f9c78b2bSJens Axboe static void bio_put_slab(struct bio_set *bs) 131f9c78b2bSJens Axboe { 132f9c78b2bSJens Axboe struct bio_slab *bslab = NULL; 13349d1ec85SMing Lei unsigned int slab_size = bs_bio_slab_size(bs); 134f9c78b2bSJens Axboe 135f9c78b2bSJens Axboe mutex_lock(&bio_slab_lock); 136f9c78b2bSJens Axboe 13749d1ec85SMing Lei bslab = xa_load(&bio_slabs, slab_size); 138f9c78b2bSJens Axboe if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n")) 139f9c78b2bSJens Axboe goto out; 140f9c78b2bSJens Axboe 14149d1ec85SMing Lei WARN_ON_ONCE(bslab->slab != bs->bio_slab); 14249d1ec85SMing Lei 143f9c78b2bSJens Axboe WARN_ON(!bslab->slab_ref); 144f9c78b2bSJens Axboe 145f9c78b2bSJens Axboe if (--bslab->slab_ref) 146f9c78b2bSJens Axboe goto out; 147f9c78b2bSJens Axboe 14849d1ec85SMing Lei xa_erase(&bio_slabs, slab_size); 14949d1ec85SMing Lei 150f9c78b2bSJens Axboe kmem_cache_destroy(bslab->slab); 15149d1ec85SMing Lei kfree(bslab); 152f9c78b2bSJens Axboe 153f9c78b2bSJens Axboe out: 154f9c78b2bSJens Axboe mutex_unlock(&bio_slab_lock); 155f9c78b2bSJens Axboe } 156f9c78b2bSJens Axboe 1577a800a20SChristoph Hellwig void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs) 158f9c78b2bSJens Axboe { 159*9e8c0d0dSChristoph Hellwig BUG_ON(nr_vecs > BIO_MAX_VECS); 160f9c78b2bSJens Axboe 161a8affc03SChristoph Hellwig if (nr_vecs == BIO_MAX_VECS) 162f9c78b2bSJens Axboe mempool_free(bv, pool); 1637a800a20SChristoph Hellwig else if (nr_vecs > BIO_INLINE_VECS) 1647a800a20SChristoph Hellwig kmem_cache_free(biovec_slab(nr_vecs)->slab, bv); 165f9c78b2bSJens Axboe } 166f9c78b2bSJens Axboe 167f2c3eb9bSChristoph Hellwig /* 168f2c3eb9bSChristoph Hellwig * Make the first allocation restricted and don't dump info on allocation 169f2c3eb9bSChristoph Hellwig * failures, since we'll fall back to the mempool in case of failure. 170f2c3eb9bSChristoph Hellwig */ 171f2c3eb9bSChristoph Hellwig static inline gfp_t bvec_alloc_gfp(gfp_t gfp) 172f9c78b2bSJens Axboe { 173f2c3eb9bSChristoph Hellwig return (gfp & ~(__GFP_DIRECT_RECLAIM | __GFP_IO)) | 174f2c3eb9bSChristoph Hellwig __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; 175f2c3eb9bSChristoph Hellwig } 176f2c3eb9bSChristoph Hellwig 1777a800a20SChristoph Hellwig struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs, 1787a800a20SChristoph Hellwig gfp_t gfp_mask) 179f9c78b2bSJens Axboe { 1807a800a20SChristoph Hellwig struct biovec_slab *bvs = biovec_slab(*nr_vecs); 1817a800a20SChristoph Hellwig 1827a800a20SChristoph Hellwig if (WARN_ON_ONCE(!bvs)) 183f9c78b2bSJens Axboe return NULL; 1847a800a20SChristoph Hellwig 1857a800a20SChristoph Hellwig /* 1867a800a20SChristoph Hellwig * Upgrade the nr_vecs request to take full advantage of the allocation. 1877a800a20SChristoph Hellwig * We also rely on this in the bvec_free path. 1887a800a20SChristoph Hellwig */ 1897a800a20SChristoph Hellwig *nr_vecs = bvs->nr_vecs; 190f9c78b2bSJens Axboe 191f9c78b2bSJens Axboe /* 192f007a3d6SChristoph Hellwig * Try a slab allocation first for all smaller allocations. If that 193f007a3d6SChristoph Hellwig * fails and __GFP_DIRECT_RECLAIM is set retry with the mempool. 194a8affc03SChristoph Hellwig * The mempool is sized to handle up to BIO_MAX_VECS entries. 195f9c78b2bSJens Axboe */ 196a8affc03SChristoph Hellwig if (*nr_vecs < BIO_MAX_VECS) { 197f9c78b2bSJens Axboe struct bio_vec *bvl; 198f9c78b2bSJens Axboe 199f2c3eb9bSChristoph Hellwig bvl = kmem_cache_alloc(bvs->slab, bvec_alloc_gfp(gfp_mask)); 2007a800a20SChristoph Hellwig if (likely(bvl) || !(gfp_mask & __GFP_DIRECT_RECLAIM)) 201f9c78b2bSJens Axboe return bvl; 202a8affc03SChristoph Hellwig *nr_vecs = BIO_MAX_VECS; 203f9c78b2bSJens Axboe } 204f9c78b2bSJens Axboe 205f007a3d6SChristoph Hellwig return mempool_alloc(pool, gfp_mask); 206f9c78b2bSJens Axboe } 207f9c78b2bSJens Axboe 2089ae3b3f5SJens Axboe void bio_uninit(struct bio *bio) 209f9c78b2bSJens Axboe { 210db9819c7SChristoph Hellwig #ifdef CONFIG_BLK_CGROUP 211db9819c7SChristoph Hellwig if (bio->bi_blkg) { 212db9819c7SChristoph Hellwig blkg_put(bio->bi_blkg); 213db9819c7SChristoph Hellwig bio->bi_blkg = NULL; 214db9819c7SChristoph Hellwig } 215db9819c7SChristoph Hellwig #endif 216ece841abSJustin Tee if (bio_integrity(bio)) 217ece841abSJustin Tee bio_integrity_free(bio); 218a892c8d5SSatya Tangirala 219a892c8d5SSatya Tangirala bio_crypt_free_ctx(bio); 220f9c78b2bSJens Axboe } 2219ae3b3f5SJens Axboe EXPORT_SYMBOL(bio_uninit); 222f9c78b2bSJens Axboe 223f9c78b2bSJens Axboe static void bio_free(struct bio *bio) 224f9c78b2bSJens Axboe { 225f9c78b2bSJens Axboe struct bio_set *bs = bio->bi_pool; 226f9c78b2bSJens Axboe void *p; 227f9c78b2bSJens Axboe 2289ae3b3f5SJens Axboe bio_uninit(bio); 229f9c78b2bSJens Axboe 230f9c78b2bSJens Axboe if (bs) { 2317a800a20SChristoph Hellwig bvec_free(&bs->bvec_pool, bio->bi_io_vec, bio->bi_max_vecs); 232f9c78b2bSJens Axboe 233f9c78b2bSJens Axboe /* 234f9c78b2bSJens Axboe * If we have front padding, adjust the bio pointer before freeing 235f9c78b2bSJens Axboe */ 236f9c78b2bSJens Axboe p = bio; 237f9c78b2bSJens Axboe p -= bs->front_pad; 238f9c78b2bSJens Axboe 2398aa6ba2fSKent Overstreet mempool_free(p, &bs->bio_pool); 240f9c78b2bSJens Axboe } else { 241f9c78b2bSJens Axboe /* Bio was allocated by bio_kmalloc() */ 242f9c78b2bSJens Axboe kfree(bio); 243f9c78b2bSJens Axboe } 244f9c78b2bSJens Axboe } 245f9c78b2bSJens Axboe 2469ae3b3f5SJens Axboe /* 2479ae3b3f5SJens Axboe * Users of this function have their own bio allocation. Subsequently, 2489ae3b3f5SJens Axboe * they must remember to pair any call to bio_init() with bio_uninit() 2499ae3b3f5SJens Axboe * when IO has completed, or when the bio is released. 2509ae3b3f5SJens Axboe */ 2513a83f467SMing Lei void bio_init(struct bio *bio, struct bio_vec *table, 2523a83f467SMing Lei unsigned short max_vecs) 253f9c78b2bSJens Axboe { 254da521626SJens Axboe bio->bi_next = NULL; 255da521626SJens Axboe bio->bi_bdev = NULL; 256da521626SJens Axboe bio->bi_opf = 0; 257da521626SJens Axboe bio->bi_flags = 0; 258da521626SJens Axboe bio->bi_ioprio = 0; 259da521626SJens Axboe bio->bi_write_hint = 0; 260da521626SJens Axboe bio->bi_status = 0; 261da521626SJens Axboe bio->bi_iter.bi_sector = 0; 262da521626SJens Axboe bio->bi_iter.bi_size = 0; 263da521626SJens Axboe bio->bi_iter.bi_idx = 0; 264da521626SJens Axboe bio->bi_iter.bi_bvec_done = 0; 265da521626SJens Axboe bio->bi_end_io = NULL; 266da521626SJens Axboe bio->bi_private = NULL; 267da521626SJens Axboe #ifdef CONFIG_BLK_CGROUP 268da521626SJens Axboe bio->bi_blkg = NULL; 269da521626SJens Axboe bio->bi_issue.value = 0; 270da521626SJens Axboe #ifdef CONFIG_BLK_CGROUP_IOCOST 271da521626SJens Axboe bio->bi_iocost_cost = 0; 272da521626SJens Axboe #endif 273da521626SJens Axboe #endif 274da521626SJens Axboe #ifdef CONFIG_BLK_INLINE_ENCRYPTION 275da521626SJens Axboe bio->bi_crypt_context = NULL; 276da521626SJens Axboe #endif 277da521626SJens Axboe #ifdef CONFIG_BLK_DEV_INTEGRITY 278da521626SJens Axboe bio->bi_integrity = NULL; 279da521626SJens Axboe #endif 280da521626SJens Axboe bio->bi_vcnt = 0; 281da521626SJens Axboe 282c4cf5261SJens Axboe atomic_set(&bio->__bi_remaining, 1); 283dac56212SJens Axboe atomic_set(&bio->__bi_cnt, 1); 2843a83f467SMing Lei 2853a83f467SMing Lei bio->bi_max_vecs = max_vecs; 286da521626SJens Axboe bio->bi_io_vec = table; 287da521626SJens Axboe bio->bi_pool = NULL; 288f9c78b2bSJens Axboe } 289f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_init); 290f9c78b2bSJens Axboe 291f9c78b2bSJens Axboe /** 292f9c78b2bSJens Axboe * bio_reset - reinitialize a bio 293f9c78b2bSJens Axboe * @bio: bio to reset 294f9c78b2bSJens Axboe * 295f9c78b2bSJens Axboe * Description: 296f9c78b2bSJens Axboe * After calling bio_reset(), @bio will be in the same state as a freshly 297f9c78b2bSJens Axboe * allocated bio returned bio bio_alloc_bioset() - the only fields that are 298f9c78b2bSJens Axboe * preserved are the ones that are initialized by bio_alloc_bioset(). See 299f9c78b2bSJens Axboe * comment in struct bio. 300f9c78b2bSJens Axboe */ 301f9c78b2bSJens Axboe void bio_reset(struct bio *bio) 302f9c78b2bSJens Axboe { 3039ae3b3f5SJens Axboe bio_uninit(bio); 304f9c78b2bSJens Axboe memset(bio, 0, BIO_RESET_BYTES); 305c4cf5261SJens Axboe atomic_set(&bio->__bi_remaining, 1); 306f9c78b2bSJens Axboe } 307f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_reset); 308f9c78b2bSJens Axboe 30938f8baaeSChristoph Hellwig static struct bio *__bio_chain_endio(struct bio *bio) 310f9c78b2bSJens Axboe { 3114246a0b6SChristoph Hellwig struct bio *parent = bio->bi_private; 3124246a0b6SChristoph Hellwig 3133edf5346SYufen Yu if (bio->bi_status && !parent->bi_status) 3144e4cbee9SChristoph Hellwig parent->bi_status = bio->bi_status; 315f9c78b2bSJens Axboe bio_put(bio); 31638f8baaeSChristoph Hellwig return parent; 31738f8baaeSChristoph Hellwig } 31838f8baaeSChristoph Hellwig 31938f8baaeSChristoph Hellwig static void bio_chain_endio(struct bio *bio) 32038f8baaeSChristoph Hellwig { 32138f8baaeSChristoph Hellwig bio_endio(__bio_chain_endio(bio)); 322f9c78b2bSJens Axboe } 323f9c78b2bSJens Axboe 324f9c78b2bSJens Axboe /** 325f9c78b2bSJens Axboe * bio_chain - chain bio completions 326f9c78b2bSJens Axboe * @bio: the target bio 3275b874af6SMauro Carvalho Chehab * @parent: the parent bio of @bio 328f9c78b2bSJens Axboe * 329f9c78b2bSJens Axboe * The caller won't have a bi_end_io called when @bio completes - instead, 330f9c78b2bSJens Axboe * @parent's bi_end_io won't be called until both @parent and @bio have 331f9c78b2bSJens Axboe * completed; the chained bio will also be freed when it completes. 332f9c78b2bSJens Axboe * 333f9c78b2bSJens Axboe * The caller must not set bi_private or bi_end_io in @bio. 334f9c78b2bSJens Axboe */ 335f9c78b2bSJens Axboe void bio_chain(struct bio *bio, struct bio *parent) 336f9c78b2bSJens Axboe { 337f9c78b2bSJens Axboe BUG_ON(bio->bi_private || bio->bi_end_io); 338f9c78b2bSJens Axboe 339f9c78b2bSJens Axboe bio->bi_private = parent; 340f9c78b2bSJens Axboe bio->bi_end_io = bio_chain_endio; 341c4cf5261SJens Axboe bio_inc_remaining(parent); 342f9c78b2bSJens Axboe } 343f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_chain); 344f9c78b2bSJens Axboe 345f9c78b2bSJens Axboe static void bio_alloc_rescue(struct work_struct *work) 346f9c78b2bSJens Axboe { 347f9c78b2bSJens Axboe struct bio_set *bs = container_of(work, struct bio_set, rescue_work); 348f9c78b2bSJens Axboe struct bio *bio; 349f9c78b2bSJens Axboe 350f9c78b2bSJens Axboe while (1) { 351f9c78b2bSJens Axboe spin_lock(&bs->rescue_lock); 352f9c78b2bSJens Axboe bio = bio_list_pop(&bs->rescue_list); 353f9c78b2bSJens Axboe spin_unlock(&bs->rescue_lock); 354f9c78b2bSJens Axboe 355f9c78b2bSJens Axboe if (!bio) 356f9c78b2bSJens Axboe break; 357f9c78b2bSJens Axboe 358ed00aabdSChristoph Hellwig submit_bio_noacct(bio); 359f9c78b2bSJens Axboe } 360f9c78b2bSJens Axboe } 361f9c78b2bSJens Axboe 362f9c78b2bSJens Axboe static void punt_bios_to_rescuer(struct bio_set *bs) 363f9c78b2bSJens Axboe { 364f9c78b2bSJens Axboe struct bio_list punt, nopunt; 365f9c78b2bSJens Axboe struct bio *bio; 366f9c78b2bSJens Axboe 36747e0fb46SNeilBrown if (WARN_ON_ONCE(!bs->rescue_workqueue)) 36847e0fb46SNeilBrown return; 369f9c78b2bSJens Axboe /* 370f9c78b2bSJens Axboe * In order to guarantee forward progress we must punt only bios that 371f9c78b2bSJens Axboe * were allocated from this bio_set; otherwise, if there was a bio on 372f9c78b2bSJens Axboe * there for a stacking driver higher up in the stack, processing it 373f9c78b2bSJens Axboe * could require allocating bios from this bio_set, and doing that from 374f9c78b2bSJens Axboe * our own rescuer would be bad. 375f9c78b2bSJens Axboe * 376f9c78b2bSJens Axboe * Since bio lists are singly linked, pop them all instead of trying to 377f9c78b2bSJens Axboe * remove from the middle of the list: 378f9c78b2bSJens Axboe */ 379f9c78b2bSJens Axboe 380f9c78b2bSJens Axboe bio_list_init(&punt); 381f9c78b2bSJens Axboe bio_list_init(&nopunt); 382f9c78b2bSJens Axboe 383f5fe1b51SNeilBrown while ((bio = bio_list_pop(¤t->bio_list[0]))) 384f9c78b2bSJens Axboe bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio); 385f5fe1b51SNeilBrown current->bio_list[0] = nopunt; 386f9c78b2bSJens Axboe 387f5fe1b51SNeilBrown bio_list_init(&nopunt); 388f5fe1b51SNeilBrown while ((bio = bio_list_pop(¤t->bio_list[1]))) 389f5fe1b51SNeilBrown bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio); 390f5fe1b51SNeilBrown current->bio_list[1] = nopunt; 391f9c78b2bSJens Axboe 392f9c78b2bSJens Axboe spin_lock(&bs->rescue_lock); 393f9c78b2bSJens Axboe bio_list_merge(&bs->rescue_list, &punt); 394f9c78b2bSJens Axboe spin_unlock(&bs->rescue_lock); 395f9c78b2bSJens Axboe 396f9c78b2bSJens Axboe queue_work(bs->rescue_workqueue, &bs->rescue_work); 397f9c78b2bSJens Axboe } 398f9c78b2bSJens Axboe 399f9c78b2bSJens Axboe /** 400f9c78b2bSJens Axboe * bio_alloc_bioset - allocate a bio for I/O 401519c8e9fSRandy Dunlap * @gfp_mask: the GFP_* mask given to the slab allocator 402f9c78b2bSJens Axboe * @nr_iovecs: number of iovecs to pre-allocate 403f9c78b2bSJens Axboe * @bs: the bio_set to allocate from. 404f9c78b2bSJens Axboe * 4053175199aSChristoph Hellwig * Allocate a bio from the mempools in @bs. 406f9c78b2bSJens Axboe * 4073175199aSChristoph Hellwig * If %__GFP_DIRECT_RECLAIM is set then bio_alloc will always be able to 4083175199aSChristoph Hellwig * allocate a bio. This is due to the mempool guarantees. To make this work, 4093175199aSChristoph Hellwig * callers must never allocate more than 1 bio at a time from the general pool. 4103175199aSChristoph Hellwig * Callers that need to allocate more than 1 bio must always submit the 4113175199aSChristoph Hellwig * previously allocated bio for IO before attempting to allocate a new one. 4123175199aSChristoph Hellwig * Failure to do so can cause deadlocks under memory pressure. 413f9c78b2bSJens Axboe * 4143175199aSChristoph Hellwig * Note that when running under submit_bio_noacct() (i.e. any block driver), 4153175199aSChristoph Hellwig * bios are not submitted until after you return - see the code in 416ed00aabdSChristoph Hellwig * submit_bio_noacct() that converts recursion into iteration, to prevent 417f9c78b2bSJens Axboe * stack overflows. 418f9c78b2bSJens Axboe * 4193175199aSChristoph Hellwig * This would normally mean allocating multiple bios under submit_bio_noacct() 4203175199aSChristoph Hellwig * would be susceptible to deadlocks, but we have 421f9c78b2bSJens Axboe * deadlock avoidance code that resubmits any blocked bios from a rescuer 422f9c78b2bSJens Axboe * thread. 423f9c78b2bSJens Axboe * 424f9c78b2bSJens Axboe * However, we do not guarantee forward progress for allocations from other 425f9c78b2bSJens Axboe * mempools. Doing multiple allocations from the same mempool under 426ed00aabdSChristoph Hellwig * submit_bio_noacct() should be avoided - instead, use bio_set's front_pad 427f9c78b2bSJens Axboe * for per bio allocations. 428f9c78b2bSJens Axboe * 4293175199aSChristoph Hellwig * Returns: Pointer to new bio on success, NULL on failure. 430f9c78b2bSJens Axboe */ 4310f2e6ab8SChristoph Hellwig struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned short nr_iovecs, 4327a88fa19SDan Carpenter struct bio_set *bs) 433f9c78b2bSJens Axboe { 434f9c78b2bSJens Axboe gfp_t saved_gfp = gfp_mask; 435f9c78b2bSJens Axboe struct bio *bio; 436f9c78b2bSJens Axboe void *p; 437f9c78b2bSJens Axboe 4383175199aSChristoph Hellwig /* should not use nobvec bioset for nr_iovecs > 0 */ 4393175199aSChristoph Hellwig if (WARN_ON_ONCE(!mempool_initialized(&bs->bvec_pool) && nr_iovecs > 0)) 440f9c78b2bSJens Axboe return NULL; 441f9c78b2bSJens Axboe 442f9c78b2bSJens Axboe /* 4433175199aSChristoph Hellwig * submit_bio_noacct() converts recursion to iteration; this means if 4443175199aSChristoph Hellwig * we're running beneath it, any bios we allocate and submit will not be 4453175199aSChristoph Hellwig * submitted (and thus freed) until after we return. 446f9c78b2bSJens Axboe * 4473175199aSChristoph Hellwig * This exposes us to a potential deadlock if we allocate multiple bios 4483175199aSChristoph Hellwig * from the same bio_set() while running underneath submit_bio_noacct(). 4493175199aSChristoph Hellwig * If we were to allocate multiple bios (say a stacking block driver 4503175199aSChristoph Hellwig * that was splitting bios), we would deadlock if we exhausted the 4513175199aSChristoph Hellwig * mempool's reserve. 452f9c78b2bSJens Axboe * 453f9c78b2bSJens Axboe * We solve this, and guarantee forward progress, with a rescuer 4543175199aSChristoph Hellwig * workqueue per bio_set. If we go to allocate and there are bios on 4553175199aSChristoph Hellwig * current->bio_list, we first try the allocation without 4563175199aSChristoph Hellwig * __GFP_DIRECT_RECLAIM; if that fails, we punt those bios we would be 4573175199aSChristoph Hellwig * blocking to the rescuer workqueue before we retry with the original 4583175199aSChristoph Hellwig * gfp_flags. 459f9c78b2bSJens Axboe */ 460f5fe1b51SNeilBrown if (current->bio_list && 461f5fe1b51SNeilBrown (!bio_list_empty(¤t->bio_list[0]) || 46247e0fb46SNeilBrown !bio_list_empty(¤t->bio_list[1])) && 46347e0fb46SNeilBrown bs->rescue_workqueue) 464d0164adcSMel Gorman gfp_mask &= ~__GFP_DIRECT_RECLAIM; 465f9c78b2bSJens Axboe 4668aa6ba2fSKent Overstreet p = mempool_alloc(&bs->bio_pool, gfp_mask); 467f9c78b2bSJens Axboe if (!p && gfp_mask != saved_gfp) { 468f9c78b2bSJens Axboe punt_bios_to_rescuer(bs); 469f9c78b2bSJens Axboe gfp_mask = saved_gfp; 4708aa6ba2fSKent Overstreet p = mempool_alloc(&bs->bio_pool, gfp_mask); 471f9c78b2bSJens Axboe } 472f9c78b2bSJens Axboe if (unlikely(!p)) 473f9c78b2bSJens Axboe return NULL; 474f9c78b2bSJens Axboe 4753175199aSChristoph Hellwig bio = p + bs->front_pad; 4763175199aSChristoph Hellwig if (nr_iovecs > BIO_INLINE_VECS) { 4773175199aSChristoph Hellwig struct bio_vec *bvl = NULL; 478f9c78b2bSJens Axboe 4797a800a20SChristoph Hellwig bvl = bvec_alloc(&bs->bvec_pool, &nr_iovecs, gfp_mask); 480f9c78b2bSJens Axboe if (!bvl && gfp_mask != saved_gfp) { 481f9c78b2bSJens Axboe punt_bios_to_rescuer(bs); 482f9c78b2bSJens Axboe gfp_mask = saved_gfp; 4837a800a20SChristoph Hellwig bvl = bvec_alloc(&bs->bvec_pool, &nr_iovecs, gfp_mask); 484f9c78b2bSJens Axboe } 485f9c78b2bSJens Axboe if (unlikely(!bvl)) 486f9c78b2bSJens Axboe goto err_free; 487f9c78b2bSJens Axboe 4887a800a20SChristoph Hellwig bio_init(bio, bvl, nr_iovecs); 489f9c78b2bSJens Axboe } else if (nr_iovecs) { 4903175199aSChristoph Hellwig bio_init(bio, bio->bi_inline_vecs, BIO_INLINE_VECS); 4913175199aSChristoph Hellwig } else { 4923175199aSChristoph Hellwig bio_init(bio, NULL, 0); 493f9c78b2bSJens Axboe } 494f9c78b2bSJens Axboe 495f9c78b2bSJens Axboe bio->bi_pool = bs; 496f9c78b2bSJens Axboe return bio; 497f9c78b2bSJens Axboe 498f9c78b2bSJens Axboe err_free: 4998aa6ba2fSKent Overstreet mempool_free(p, &bs->bio_pool); 500f9c78b2bSJens Axboe return NULL; 501f9c78b2bSJens Axboe } 502f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_alloc_bioset); 503f9c78b2bSJens Axboe 5043175199aSChristoph Hellwig /** 5053175199aSChristoph Hellwig * bio_kmalloc - kmalloc a bio for I/O 5063175199aSChristoph Hellwig * @gfp_mask: the GFP_* mask given to the slab allocator 5073175199aSChristoph Hellwig * @nr_iovecs: number of iovecs to pre-allocate 5083175199aSChristoph Hellwig * 5093175199aSChristoph Hellwig * Use kmalloc to allocate and initialize a bio. 5103175199aSChristoph Hellwig * 5113175199aSChristoph Hellwig * Returns: Pointer to new bio on success, NULL on failure. 5123175199aSChristoph Hellwig */ 5130f2e6ab8SChristoph Hellwig struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned short nr_iovecs) 5143175199aSChristoph Hellwig { 5153175199aSChristoph Hellwig struct bio *bio; 5163175199aSChristoph Hellwig 5173175199aSChristoph Hellwig if (nr_iovecs > UIO_MAXIOV) 5183175199aSChristoph Hellwig return NULL; 5193175199aSChristoph Hellwig 5203175199aSChristoph Hellwig bio = kmalloc(struct_size(bio, bi_inline_vecs, nr_iovecs), gfp_mask); 5213175199aSChristoph Hellwig if (unlikely(!bio)) 5223175199aSChristoph Hellwig return NULL; 5233175199aSChristoph Hellwig bio_init(bio, nr_iovecs ? bio->bi_inline_vecs : NULL, nr_iovecs); 5243175199aSChristoph Hellwig bio->bi_pool = NULL; 5253175199aSChristoph Hellwig return bio; 5263175199aSChristoph Hellwig } 5273175199aSChristoph Hellwig EXPORT_SYMBOL(bio_kmalloc); 5283175199aSChristoph Hellwig 5296f822e1bSChristoph Hellwig void zero_fill_bio(struct bio *bio) 530f9c78b2bSJens Axboe { 531f9c78b2bSJens Axboe struct bio_vec bv; 532f9c78b2bSJens Axboe struct bvec_iter iter; 533f9c78b2bSJens Axboe 534ab6c340eSChristoph Hellwig bio_for_each_segment(bv, bio, iter) 535ab6c340eSChristoph Hellwig memzero_bvec(&bv); 536f9c78b2bSJens Axboe } 5376f822e1bSChristoph Hellwig EXPORT_SYMBOL(zero_fill_bio); 538f9c78b2bSJens Axboe 53983c9c547SMing Lei /** 54083c9c547SMing Lei * bio_truncate - truncate the bio to small size of @new_size 54183c9c547SMing Lei * @bio: the bio to be truncated 54283c9c547SMing Lei * @new_size: new size for truncating the bio 54383c9c547SMing Lei * 54483c9c547SMing Lei * Description: 54583c9c547SMing Lei * Truncate the bio to new size of @new_size. If bio_op(bio) is 54683c9c547SMing Lei * REQ_OP_READ, zero the truncated part. This function should only 54783c9c547SMing Lei * be used for handling corner cases, such as bio eod. 54883c9c547SMing Lei */ 54985a8ce62SMing Lei void bio_truncate(struct bio *bio, unsigned new_size) 55085a8ce62SMing Lei { 55185a8ce62SMing Lei struct bio_vec bv; 55285a8ce62SMing Lei struct bvec_iter iter; 55385a8ce62SMing Lei unsigned int done = 0; 55485a8ce62SMing Lei bool truncated = false; 55585a8ce62SMing Lei 55685a8ce62SMing Lei if (new_size >= bio->bi_iter.bi_size) 55785a8ce62SMing Lei return; 55885a8ce62SMing Lei 55983c9c547SMing Lei if (bio_op(bio) != REQ_OP_READ) 56085a8ce62SMing Lei goto exit; 56185a8ce62SMing Lei 56285a8ce62SMing Lei bio_for_each_segment(bv, bio, iter) { 56385a8ce62SMing Lei if (done + bv.bv_len > new_size) { 56485a8ce62SMing Lei unsigned offset; 56585a8ce62SMing Lei 56685a8ce62SMing Lei if (!truncated) 56785a8ce62SMing Lei offset = new_size - done; 56885a8ce62SMing Lei else 56985a8ce62SMing Lei offset = 0; 57085a8ce62SMing Lei zero_user(bv.bv_page, offset, bv.bv_len - offset); 57185a8ce62SMing Lei truncated = true; 57285a8ce62SMing Lei } 57385a8ce62SMing Lei done += bv.bv_len; 57485a8ce62SMing Lei } 57585a8ce62SMing Lei 57685a8ce62SMing Lei exit: 57785a8ce62SMing Lei /* 57885a8ce62SMing Lei * Don't touch bvec table here and make it really immutable, since 57985a8ce62SMing Lei * fs bio user has to retrieve all pages via bio_for_each_segment_all 58085a8ce62SMing Lei * in its .end_bio() callback. 58185a8ce62SMing Lei * 58285a8ce62SMing Lei * It is enough to truncate bio by updating .bi_size since we can make 58385a8ce62SMing Lei * correct bvec with the updated .bi_size for drivers. 58485a8ce62SMing Lei */ 58585a8ce62SMing Lei bio->bi_iter.bi_size = new_size; 58685a8ce62SMing Lei } 58785a8ce62SMing Lei 588f9c78b2bSJens Axboe /** 58929125ed6SChristoph Hellwig * guard_bio_eod - truncate a BIO to fit the block device 59029125ed6SChristoph Hellwig * @bio: bio to truncate 59129125ed6SChristoph Hellwig * 59229125ed6SChristoph Hellwig * This allows us to do IO even on the odd last sectors of a device, even if the 59329125ed6SChristoph Hellwig * block size is some multiple of the physical sector size. 59429125ed6SChristoph Hellwig * 59529125ed6SChristoph Hellwig * We'll just truncate the bio to the size of the device, and clear the end of 59629125ed6SChristoph Hellwig * the buffer head manually. Truly out-of-range accesses will turn into actual 59729125ed6SChristoph Hellwig * I/O errors, this only handles the "we need to be able to do I/O at the final 59829125ed6SChristoph Hellwig * sector" case. 59929125ed6SChristoph Hellwig */ 60029125ed6SChristoph Hellwig void guard_bio_eod(struct bio *bio) 60129125ed6SChristoph Hellwig { 602309dca30SChristoph Hellwig sector_t maxsector = bdev_nr_sectors(bio->bi_bdev); 60329125ed6SChristoph Hellwig 60429125ed6SChristoph Hellwig if (!maxsector) 60529125ed6SChristoph Hellwig return; 60629125ed6SChristoph Hellwig 60729125ed6SChristoph Hellwig /* 60829125ed6SChristoph Hellwig * If the *whole* IO is past the end of the device, 60929125ed6SChristoph Hellwig * let it through, and the IO layer will turn it into 61029125ed6SChristoph Hellwig * an EIO. 61129125ed6SChristoph Hellwig */ 61229125ed6SChristoph Hellwig if (unlikely(bio->bi_iter.bi_sector >= maxsector)) 61329125ed6SChristoph Hellwig return; 61429125ed6SChristoph Hellwig 61529125ed6SChristoph Hellwig maxsector -= bio->bi_iter.bi_sector; 61629125ed6SChristoph Hellwig if (likely((bio->bi_iter.bi_size >> 9) <= maxsector)) 61729125ed6SChristoph Hellwig return; 61829125ed6SChristoph Hellwig 61929125ed6SChristoph Hellwig bio_truncate(bio, maxsector << 9); 62029125ed6SChristoph Hellwig } 62129125ed6SChristoph Hellwig 622be4d234dSJens Axboe #define ALLOC_CACHE_MAX 512 623be4d234dSJens Axboe #define ALLOC_CACHE_SLACK 64 624be4d234dSJens Axboe 625be4d234dSJens Axboe static void bio_alloc_cache_prune(struct bio_alloc_cache *cache, 626be4d234dSJens Axboe unsigned int nr) 627be4d234dSJens Axboe { 628be4d234dSJens Axboe unsigned int i = 0; 629be4d234dSJens Axboe struct bio *bio; 630be4d234dSJens Axboe 631be4d234dSJens Axboe while ((bio = bio_list_pop(&cache->free_list)) != NULL) { 632be4d234dSJens Axboe cache->nr--; 633be4d234dSJens Axboe bio_free(bio); 634be4d234dSJens Axboe if (++i == nr) 635be4d234dSJens Axboe break; 636be4d234dSJens Axboe } 637be4d234dSJens Axboe } 638be4d234dSJens Axboe 639be4d234dSJens Axboe static int bio_cpu_dead(unsigned int cpu, struct hlist_node *node) 640be4d234dSJens Axboe { 641be4d234dSJens Axboe struct bio_set *bs; 642be4d234dSJens Axboe 643be4d234dSJens Axboe bs = hlist_entry_safe(node, struct bio_set, cpuhp_dead); 644be4d234dSJens Axboe if (bs->cache) { 645be4d234dSJens Axboe struct bio_alloc_cache *cache = per_cpu_ptr(bs->cache, cpu); 646be4d234dSJens Axboe 647be4d234dSJens Axboe bio_alloc_cache_prune(cache, -1U); 648be4d234dSJens Axboe } 649be4d234dSJens Axboe return 0; 650be4d234dSJens Axboe } 651be4d234dSJens Axboe 652be4d234dSJens Axboe static void bio_alloc_cache_destroy(struct bio_set *bs) 653be4d234dSJens Axboe { 654be4d234dSJens Axboe int cpu; 655be4d234dSJens Axboe 656be4d234dSJens Axboe if (!bs->cache) 657be4d234dSJens Axboe return; 658be4d234dSJens Axboe 659be4d234dSJens Axboe cpuhp_state_remove_instance_nocalls(CPUHP_BIO_DEAD, &bs->cpuhp_dead); 660be4d234dSJens Axboe for_each_possible_cpu(cpu) { 661be4d234dSJens Axboe struct bio_alloc_cache *cache; 662be4d234dSJens Axboe 663be4d234dSJens Axboe cache = per_cpu_ptr(bs->cache, cpu); 664be4d234dSJens Axboe bio_alloc_cache_prune(cache, -1U); 665be4d234dSJens Axboe } 666be4d234dSJens Axboe free_percpu(bs->cache); 667be4d234dSJens Axboe } 668be4d234dSJens Axboe 66929125ed6SChristoph Hellwig /** 670f9c78b2bSJens Axboe * bio_put - release a reference to a bio 671f9c78b2bSJens Axboe * @bio: bio to release reference to 672f9c78b2bSJens Axboe * 673f9c78b2bSJens Axboe * Description: 674f9c78b2bSJens Axboe * Put a reference to a &struct bio, either one you have gotten with 6759b10f6a9SNeilBrown * bio_alloc, bio_get or bio_clone_*. The last put of a bio will free it. 676f9c78b2bSJens Axboe **/ 677f9c78b2bSJens Axboe void bio_put(struct bio *bio) 678f9c78b2bSJens Axboe { 679be4d234dSJens Axboe if (unlikely(bio_flagged(bio, BIO_REFFED))) { 680*9e8c0d0dSChristoph Hellwig BUG_ON(!atomic_read(&bio->__bi_cnt)); 681be4d234dSJens Axboe if (!atomic_dec_and_test(&bio->__bi_cnt)) 682be4d234dSJens Axboe return; 683be4d234dSJens Axboe } 684f9c78b2bSJens Axboe 685be4d234dSJens Axboe if (bio_flagged(bio, BIO_PERCPU_CACHE)) { 686be4d234dSJens Axboe struct bio_alloc_cache *cache; 687be4d234dSJens Axboe 688be4d234dSJens Axboe bio_uninit(bio); 689be4d234dSJens Axboe cache = per_cpu_ptr(bio->bi_pool->cache, get_cpu()); 690be4d234dSJens Axboe bio_list_add_head(&cache->free_list, bio); 691be4d234dSJens Axboe if (++cache->nr > ALLOC_CACHE_MAX + ALLOC_CACHE_SLACK) 692be4d234dSJens Axboe bio_alloc_cache_prune(cache, ALLOC_CACHE_SLACK); 693be4d234dSJens Axboe put_cpu(); 694be4d234dSJens Axboe } else { 695f9c78b2bSJens Axboe bio_free(bio); 696f9c78b2bSJens Axboe } 697dac56212SJens Axboe } 698f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_put); 699f9c78b2bSJens Axboe 700f9c78b2bSJens Axboe /** 701f9c78b2bSJens Axboe * __bio_clone_fast - clone a bio that shares the original bio's biovec 702f9c78b2bSJens Axboe * @bio: destination bio 703f9c78b2bSJens Axboe * @bio_src: bio to clone 704f9c78b2bSJens Axboe * 705f9c78b2bSJens Axboe * Clone a &bio. Caller will own the returned bio, but not 706f9c78b2bSJens Axboe * the actual data it points to. Reference count of returned 707f9c78b2bSJens Axboe * bio will be one. 708f9c78b2bSJens Axboe * 709f9c78b2bSJens Axboe * Caller must ensure that @bio_src is not freed before @bio. 710f9c78b2bSJens Axboe */ 711f9c78b2bSJens Axboe void __bio_clone_fast(struct bio *bio, struct bio *bio_src) 712f9c78b2bSJens Axboe { 7137a800a20SChristoph Hellwig WARN_ON_ONCE(bio->bi_pool && bio->bi_max_vecs); 714f9c78b2bSJens Axboe 715f9c78b2bSJens Axboe /* 716309dca30SChristoph Hellwig * most users will be overriding ->bi_bdev with a new target, 717f9c78b2bSJens Axboe * so we don't set nor calculate new physical/hw segment counts here 718f9c78b2bSJens Axboe */ 719309dca30SChristoph Hellwig bio->bi_bdev = bio_src->bi_bdev; 720b7c44ed9SJens Axboe bio_set_flag(bio, BIO_CLONED); 721111be883SShaohua Li if (bio_flagged(bio_src, BIO_THROTTLED)) 722111be883SShaohua Li bio_set_flag(bio, BIO_THROTTLED); 72346bbf653SChristoph Hellwig if (bio_flagged(bio_src, BIO_REMAPPED)) 72446bbf653SChristoph Hellwig bio_set_flag(bio, BIO_REMAPPED); 7251eff9d32SJens Axboe bio->bi_opf = bio_src->bi_opf; 726ca474b73SHannes Reinecke bio->bi_ioprio = bio_src->bi_ioprio; 727cb6934f8SJens Axboe bio->bi_write_hint = bio_src->bi_write_hint; 728f9c78b2bSJens Axboe bio->bi_iter = bio_src->bi_iter; 729f9c78b2bSJens Axboe bio->bi_io_vec = bio_src->bi_io_vec; 73020bd723eSPaolo Valente 731db6638d7SDennis Zhou bio_clone_blkg_association(bio, bio_src); 732e439bedfSDennis Zhou blkcg_bio_issue_init(bio); 733f9c78b2bSJens Axboe } 734f9c78b2bSJens Axboe EXPORT_SYMBOL(__bio_clone_fast); 735f9c78b2bSJens Axboe 736f9c78b2bSJens Axboe /** 737f9c78b2bSJens Axboe * bio_clone_fast - clone a bio that shares the original bio's biovec 738f9c78b2bSJens Axboe * @bio: bio to clone 739f9c78b2bSJens Axboe * @gfp_mask: allocation priority 740f9c78b2bSJens Axboe * @bs: bio_set to allocate from 741f9c78b2bSJens Axboe * 742f9c78b2bSJens Axboe * Like __bio_clone_fast, only also allocates the returned bio 743f9c78b2bSJens Axboe */ 744f9c78b2bSJens Axboe struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) 745f9c78b2bSJens Axboe { 746f9c78b2bSJens Axboe struct bio *b; 747f9c78b2bSJens Axboe 748f9c78b2bSJens Axboe b = bio_alloc_bioset(gfp_mask, 0, bs); 749f9c78b2bSJens Axboe if (!b) 750f9c78b2bSJens Axboe return NULL; 751f9c78b2bSJens Axboe 752f9c78b2bSJens Axboe __bio_clone_fast(b, bio); 753f9c78b2bSJens Axboe 75407560151SEric Biggers if (bio_crypt_clone(b, bio, gfp_mask) < 0) 75507560151SEric Biggers goto err_put; 756a892c8d5SSatya Tangirala 75707560151SEric Biggers if (bio_integrity(bio) && 75807560151SEric Biggers bio_integrity_clone(b, bio, gfp_mask) < 0) 75907560151SEric Biggers goto err_put; 760f9c78b2bSJens Axboe 761f9c78b2bSJens Axboe return b; 76207560151SEric Biggers 76307560151SEric Biggers err_put: 76407560151SEric Biggers bio_put(b); 76507560151SEric Biggers return NULL; 766f9c78b2bSJens Axboe } 767f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_clone_fast); 768f9c78b2bSJens Axboe 7695cbd28e3SChristoph Hellwig const char *bio_devname(struct bio *bio, char *buf) 7705cbd28e3SChristoph Hellwig { 771309dca30SChristoph Hellwig return bdevname(bio->bi_bdev, buf); 7725cbd28e3SChristoph Hellwig } 7735cbd28e3SChristoph Hellwig EXPORT_SYMBOL(bio_devname); 7745cbd28e3SChristoph Hellwig 7755919482eSMing Lei static inline bool page_is_mergeable(const struct bio_vec *bv, 7765919482eSMing Lei struct page *page, unsigned int len, unsigned int off, 777ff896738SChristoph Hellwig bool *same_page) 7785919482eSMing Lei { 779d8166519SMatthew Wilcox (Oracle) size_t bv_end = bv->bv_offset + bv->bv_len; 780d8166519SMatthew Wilcox (Oracle) phys_addr_t vec_end_addr = page_to_phys(bv->bv_page) + bv_end - 1; 7815919482eSMing Lei phys_addr_t page_addr = page_to_phys(page); 7825919482eSMing Lei 7835919482eSMing Lei if (vec_end_addr + 1 != page_addr + off) 7845919482eSMing Lei return false; 7855919482eSMing Lei if (xen_domain() && !xen_biovec_phys_mergeable(bv, page)) 7865919482eSMing Lei return false; 78752d52d1cSChristoph Hellwig 788ff896738SChristoph Hellwig *same_page = ((vec_end_addr & PAGE_MASK) == page_addr); 789d8166519SMatthew Wilcox (Oracle) if (*same_page) 7905919482eSMing Lei return true; 791d8166519SMatthew Wilcox (Oracle) return (bv->bv_page + bv_end / PAGE_SIZE) == (page + off / PAGE_SIZE); 7925919482eSMing Lei } 7935919482eSMing Lei 794e4581105SChristoph Hellwig /* 795e4581105SChristoph Hellwig * Try to merge a page into a segment, while obeying the hardware segment 796e4581105SChristoph Hellwig * size limit. This is not for normal read/write bios, but for passthrough 797e4581105SChristoph Hellwig * or Zone Append operations that we can't split. 798e4581105SChristoph Hellwig */ 799e4581105SChristoph Hellwig static bool bio_try_merge_hw_seg(struct request_queue *q, struct bio *bio, 800e4581105SChristoph Hellwig struct page *page, unsigned len, 801e4581105SChristoph Hellwig unsigned offset, bool *same_page) 802489fbbcbSMing Lei { 803384209cdSChristoph Hellwig struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1]; 804489fbbcbSMing Lei unsigned long mask = queue_segment_boundary(q); 805489fbbcbSMing Lei phys_addr_t addr1 = page_to_phys(bv->bv_page) + bv->bv_offset; 806489fbbcbSMing Lei phys_addr_t addr2 = page_to_phys(page) + offset + len - 1; 807489fbbcbSMing Lei 808489fbbcbSMing Lei if ((addr1 | mask) != (addr2 | mask)) 809489fbbcbSMing Lei return false; 810489fbbcbSMing Lei if (bv->bv_len + len > queue_max_segment_size(q)) 811489fbbcbSMing Lei return false; 812384209cdSChristoph Hellwig return __bio_try_merge_page(bio, page, len, offset, same_page); 813489fbbcbSMing Lei } 814489fbbcbSMing Lei 815f4595875SShaohua Li /** 816e4581105SChristoph Hellwig * bio_add_hw_page - attempt to add a page to a bio with hw constraints 817c66a14d0SKent Overstreet * @q: the target queue 818c66a14d0SKent Overstreet * @bio: destination bio 819c66a14d0SKent Overstreet * @page: page to add 820c66a14d0SKent Overstreet * @len: vec entry length 821c66a14d0SKent Overstreet * @offset: vec entry offset 822e4581105SChristoph Hellwig * @max_sectors: maximum number of sectors that can be added 823e4581105SChristoph Hellwig * @same_page: return if the segment has been merged inside the same page 824f9c78b2bSJens Axboe * 825e4581105SChristoph Hellwig * Add a page to a bio while respecting the hardware max_sectors, max_segment 826e4581105SChristoph Hellwig * and gap limitations. 827f9c78b2bSJens Axboe */ 828e4581105SChristoph Hellwig int bio_add_hw_page(struct request_queue *q, struct bio *bio, 82919047087SMing Lei struct page *page, unsigned int len, unsigned int offset, 830e4581105SChristoph Hellwig unsigned int max_sectors, bool *same_page) 831f9c78b2bSJens Axboe { 832f9c78b2bSJens Axboe struct bio_vec *bvec; 833f9c78b2bSJens Axboe 834e4581105SChristoph Hellwig if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED))) 835f9c78b2bSJens Axboe return 0; 836f9c78b2bSJens Axboe 837e4581105SChristoph Hellwig if (((bio->bi_iter.bi_size + len) >> 9) > max_sectors) 838f9c78b2bSJens Axboe return 0; 839f9c78b2bSJens Axboe 840f9c78b2bSJens Axboe if (bio->bi_vcnt > 0) { 841e4581105SChristoph Hellwig if (bio_try_merge_hw_seg(q, bio, page, len, offset, same_page)) 842384209cdSChristoph Hellwig return len; 843320ea869SChristoph Hellwig 844320ea869SChristoph Hellwig /* 845320ea869SChristoph Hellwig * If the queue doesn't support SG gaps and adding this segment 846320ea869SChristoph Hellwig * would create a gap, disallow it. 847320ea869SChristoph Hellwig */ 848384209cdSChristoph Hellwig bvec = &bio->bi_io_vec[bio->bi_vcnt - 1]; 849320ea869SChristoph Hellwig if (bvec_gap_to_prev(q, bvec, offset)) 850320ea869SChristoph Hellwig return 0; 851f9c78b2bSJens Axboe } 852f9c78b2bSJens Axboe 85379d08f89SMing Lei if (bio_full(bio, len)) 854f9c78b2bSJens Axboe return 0; 855f9c78b2bSJens Axboe 85614ccb66bSChristoph Hellwig if (bio->bi_vcnt >= queue_max_segments(q)) 857489fbbcbSMing Lei return 0; 858489fbbcbSMing Lei 859f9c78b2bSJens Axboe bvec = &bio->bi_io_vec[bio->bi_vcnt]; 860f9c78b2bSJens Axboe bvec->bv_page = page; 861f9c78b2bSJens Axboe bvec->bv_len = len; 862f9c78b2bSJens Axboe bvec->bv_offset = offset; 863fcbf6a08SMaurizio Lombardi bio->bi_vcnt++; 864dcdca753SChristoph Hellwig bio->bi_iter.bi_size += len; 865f9c78b2bSJens Axboe return len; 866f9c78b2bSJens Axboe } 86719047087SMing Lei 868e4581105SChristoph Hellwig /** 869e4581105SChristoph Hellwig * bio_add_pc_page - attempt to add page to passthrough bio 870e4581105SChristoph Hellwig * @q: the target queue 871e4581105SChristoph Hellwig * @bio: destination bio 872e4581105SChristoph Hellwig * @page: page to add 873e4581105SChristoph Hellwig * @len: vec entry length 874e4581105SChristoph Hellwig * @offset: vec entry offset 875e4581105SChristoph Hellwig * 876e4581105SChristoph Hellwig * Attempt to add a page to the bio_vec maplist. This can fail for a 877e4581105SChristoph Hellwig * number of reasons, such as the bio being full or target block device 878e4581105SChristoph Hellwig * limitations. The target block device must allow bio's up to PAGE_SIZE, 879e4581105SChristoph Hellwig * so it is always possible to add a single page to an empty bio. 880e4581105SChristoph Hellwig * 881e4581105SChristoph Hellwig * This should only be used by passthrough bios. 882e4581105SChristoph Hellwig */ 88319047087SMing Lei int bio_add_pc_page(struct request_queue *q, struct bio *bio, 88419047087SMing Lei struct page *page, unsigned int len, unsigned int offset) 88519047087SMing Lei { 886d1916c86SChristoph Hellwig bool same_page = false; 887e4581105SChristoph Hellwig return bio_add_hw_page(q, bio, page, len, offset, 888e4581105SChristoph Hellwig queue_max_hw_sectors(q), &same_page); 88919047087SMing Lei } 890f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_add_pc_page); 891f9c78b2bSJens Axboe 892f9c78b2bSJens Axboe /** 893ae29333fSJohannes Thumshirn * bio_add_zone_append_page - attempt to add page to zone-append bio 894ae29333fSJohannes Thumshirn * @bio: destination bio 895ae29333fSJohannes Thumshirn * @page: page to add 896ae29333fSJohannes Thumshirn * @len: vec entry length 897ae29333fSJohannes Thumshirn * @offset: vec entry offset 898ae29333fSJohannes Thumshirn * 899ae29333fSJohannes Thumshirn * Attempt to add a page to the bio_vec maplist of a bio that will be submitted 900ae29333fSJohannes Thumshirn * for a zone-append request. This can fail for a number of reasons, such as the 901ae29333fSJohannes Thumshirn * bio being full or the target block device is not a zoned block device or 902ae29333fSJohannes Thumshirn * other limitations of the target block device. The target block device must 903ae29333fSJohannes Thumshirn * allow bio's up to PAGE_SIZE, so it is always possible to add a single page 904ae29333fSJohannes Thumshirn * to an empty bio. 905ae29333fSJohannes Thumshirn * 906ae29333fSJohannes Thumshirn * Returns: number of bytes added to the bio, or 0 in case of a failure. 907ae29333fSJohannes Thumshirn */ 908ae29333fSJohannes Thumshirn int bio_add_zone_append_page(struct bio *bio, struct page *page, 909ae29333fSJohannes Thumshirn unsigned int len, unsigned int offset) 910ae29333fSJohannes Thumshirn { 911582cd91fSLinus Torvalds struct request_queue *q = bio->bi_bdev->bd_disk->queue; 912ae29333fSJohannes Thumshirn bool same_page = false; 913ae29333fSJohannes Thumshirn 914ae29333fSJohannes Thumshirn if (WARN_ON_ONCE(bio_op(bio) != REQ_OP_ZONE_APPEND)) 915ae29333fSJohannes Thumshirn return 0; 916ae29333fSJohannes Thumshirn 917ae29333fSJohannes Thumshirn if (WARN_ON_ONCE(!blk_queue_is_zoned(q))) 918ae29333fSJohannes Thumshirn return 0; 919ae29333fSJohannes Thumshirn 920ae29333fSJohannes Thumshirn return bio_add_hw_page(q, bio, page, len, offset, 921ae29333fSJohannes Thumshirn queue_max_zone_append_sectors(q), &same_page); 922ae29333fSJohannes Thumshirn } 923ae29333fSJohannes Thumshirn EXPORT_SYMBOL_GPL(bio_add_zone_append_page); 924ae29333fSJohannes Thumshirn 925ae29333fSJohannes Thumshirn /** 9260aa69fd3SChristoph Hellwig * __bio_try_merge_page - try appending data to an existing bvec. 9270aa69fd3SChristoph Hellwig * @bio: destination bio 928551879a4SMing Lei * @page: start page to add 9290aa69fd3SChristoph Hellwig * @len: length of the data to add 930551879a4SMing Lei * @off: offset of the data relative to @page 931ff896738SChristoph Hellwig * @same_page: return if the segment has been merged inside the same page 9320aa69fd3SChristoph Hellwig * 9330aa69fd3SChristoph Hellwig * Try to add the data at @page + @off to the last bvec of @bio. This is a 9343cf14889SRandy Dunlap * useful optimisation for file systems with a block size smaller than the 9350aa69fd3SChristoph Hellwig * page size. 9360aa69fd3SChristoph Hellwig * 937551879a4SMing Lei * Warn if (@len, @off) crosses pages in case that @same_page is true. 938551879a4SMing Lei * 9390aa69fd3SChristoph Hellwig * Return %true on success or %false on failure. 9400aa69fd3SChristoph Hellwig */ 9410aa69fd3SChristoph Hellwig bool __bio_try_merge_page(struct bio *bio, struct page *page, 942ff896738SChristoph Hellwig unsigned int len, unsigned int off, bool *same_page) 9430aa69fd3SChristoph Hellwig { 9440aa69fd3SChristoph Hellwig if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED))) 9450aa69fd3SChristoph Hellwig return false; 9460aa69fd3SChristoph Hellwig 947cc90bc68SAndreas Gruenbacher if (bio->bi_vcnt > 0) { 9480aa69fd3SChristoph Hellwig struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1]; 9490aa69fd3SChristoph Hellwig 9505919482eSMing Lei if (page_is_mergeable(bv, page, len, off, same_page)) { 95135c820e7SJens Axboe if (bio->bi_iter.bi_size > UINT_MAX - len) { 9522cd896a5SRitesh Harjani *same_page = false; 953cc90bc68SAndreas Gruenbacher return false; 9542cd896a5SRitesh Harjani } 9550aa69fd3SChristoph Hellwig bv->bv_len += len; 9560aa69fd3SChristoph Hellwig bio->bi_iter.bi_size += len; 9570aa69fd3SChristoph Hellwig return true; 9580aa69fd3SChristoph Hellwig } 9595919482eSMing Lei } 9600aa69fd3SChristoph Hellwig return false; 9610aa69fd3SChristoph Hellwig } 9620aa69fd3SChristoph Hellwig EXPORT_SYMBOL_GPL(__bio_try_merge_page); 9630aa69fd3SChristoph Hellwig 9640aa69fd3SChristoph Hellwig /** 965551879a4SMing Lei * __bio_add_page - add page(s) to a bio in a new segment 9660aa69fd3SChristoph Hellwig * @bio: destination bio 967551879a4SMing Lei * @page: start page to add 968551879a4SMing Lei * @len: length of the data to add, may cross pages 969551879a4SMing Lei * @off: offset of the data relative to @page, may cross pages 9700aa69fd3SChristoph Hellwig * 9710aa69fd3SChristoph Hellwig * Add the data at @page + @off to @bio as a new bvec. The caller must ensure 9720aa69fd3SChristoph Hellwig * that @bio has space for another bvec. 9730aa69fd3SChristoph Hellwig */ 9740aa69fd3SChristoph Hellwig void __bio_add_page(struct bio *bio, struct page *page, 9750aa69fd3SChristoph Hellwig unsigned int len, unsigned int off) 9760aa69fd3SChristoph Hellwig { 9770aa69fd3SChristoph Hellwig struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt]; 9780aa69fd3SChristoph Hellwig 9790aa69fd3SChristoph Hellwig WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)); 98079d08f89SMing Lei WARN_ON_ONCE(bio_full(bio, len)); 9810aa69fd3SChristoph Hellwig 9820aa69fd3SChristoph Hellwig bv->bv_page = page; 9830aa69fd3SChristoph Hellwig bv->bv_offset = off; 9840aa69fd3SChristoph Hellwig bv->bv_len = len; 9850aa69fd3SChristoph Hellwig 9860aa69fd3SChristoph Hellwig bio->bi_iter.bi_size += len; 9870aa69fd3SChristoph Hellwig bio->bi_vcnt++; 988b8e24a93SJohannes Weiner 989b8e24a93SJohannes Weiner if (!bio_flagged(bio, BIO_WORKINGSET) && unlikely(PageWorkingset(page))) 990b8e24a93SJohannes Weiner bio_set_flag(bio, BIO_WORKINGSET); 9910aa69fd3SChristoph Hellwig } 9920aa69fd3SChristoph Hellwig EXPORT_SYMBOL_GPL(__bio_add_page); 9930aa69fd3SChristoph Hellwig 9940aa69fd3SChristoph Hellwig /** 995551879a4SMing Lei * bio_add_page - attempt to add page(s) to bio 996f9c78b2bSJens Axboe * @bio: destination bio 997551879a4SMing Lei * @page: start page to add 998551879a4SMing Lei * @len: vec entry length, may cross pages 999551879a4SMing Lei * @offset: vec entry offset relative to @page, may cross pages 1000f9c78b2bSJens Axboe * 1001551879a4SMing Lei * Attempt to add page(s) to the bio_vec maplist. This will only fail 1002c66a14d0SKent Overstreet * if either bio->bi_vcnt == bio->bi_max_vecs or it's a cloned bio. 1003f9c78b2bSJens Axboe */ 1004c66a14d0SKent Overstreet int bio_add_page(struct bio *bio, struct page *page, 1005c66a14d0SKent Overstreet unsigned int len, unsigned int offset) 1006f9c78b2bSJens Axboe { 1007ff896738SChristoph Hellwig bool same_page = false; 1008ff896738SChristoph Hellwig 1009ff896738SChristoph Hellwig if (!__bio_try_merge_page(bio, page, len, offset, &same_page)) { 101079d08f89SMing Lei if (bio_full(bio, len)) 1011c66a14d0SKent Overstreet return 0; 10120aa69fd3SChristoph Hellwig __bio_add_page(bio, page, len, offset); 1013c66a14d0SKent Overstreet } 1014c66a14d0SKent Overstreet return len; 1015f9c78b2bSJens Axboe } 1016f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_add_page); 1017f9c78b2bSJens Axboe 1018d241a95fSChristoph Hellwig void bio_release_pages(struct bio *bio, bool mark_dirty) 10197321ecbfSChristoph Hellwig { 10207321ecbfSChristoph Hellwig struct bvec_iter_all iter_all; 10217321ecbfSChristoph Hellwig struct bio_vec *bvec; 10227321ecbfSChristoph Hellwig 1023b2d0d991SChristoph Hellwig if (bio_flagged(bio, BIO_NO_PAGE_REF)) 1024b2d0d991SChristoph Hellwig return; 1025b2d0d991SChristoph Hellwig 1026d241a95fSChristoph Hellwig bio_for_each_segment_all(bvec, bio, iter_all) { 1027d241a95fSChristoph Hellwig if (mark_dirty && !PageCompound(bvec->bv_page)) 1028d241a95fSChristoph Hellwig set_page_dirty_lock(bvec->bv_page); 10297321ecbfSChristoph Hellwig put_page(bvec->bv_page); 10307321ecbfSChristoph Hellwig } 1031d241a95fSChristoph Hellwig } 103229b2a3aaSJohannes Thumshirn EXPORT_SYMBOL_GPL(bio_release_pages); 10337321ecbfSChristoph Hellwig 10347de55b7dSJohannes Thumshirn static void __bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter) 10356d0c48aeSJens Axboe { 10367a800a20SChristoph Hellwig WARN_ON_ONCE(bio->bi_max_vecs); 10376d0c48aeSJens Axboe 1038c42bca92SPavel Begunkov bio->bi_vcnt = iter->nr_segs; 1039c42bca92SPavel Begunkov bio->bi_io_vec = (struct bio_vec *)iter->bvec; 1040c42bca92SPavel Begunkov bio->bi_iter.bi_bvec_done = iter->iov_offset; 1041c42bca92SPavel Begunkov bio->bi_iter.bi_size = iter->count; 1042ed97ce5eSChristoph Hellwig bio_set_flag(bio, BIO_NO_PAGE_REF); 1043977be012SChristoph Hellwig bio_set_flag(bio, BIO_CLONED); 10447de55b7dSJohannes Thumshirn } 10456d0c48aeSJens Axboe 10467de55b7dSJohannes Thumshirn static int bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter) 10477de55b7dSJohannes Thumshirn { 10487de55b7dSJohannes Thumshirn __bio_iov_bvec_set(bio, iter); 1049c42bca92SPavel Begunkov iov_iter_advance(iter, iter->count); 10506d0c48aeSJens Axboe return 0; 10516d0c48aeSJens Axboe } 10526d0c48aeSJens Axboe 10537de55b7dSJohannes Thumshirn static int bio_iov_bvec_set_append(struct bio *bio, struct iov_iter *iter) 10547de55b7dSJohannes Thumshirn { 10557de55b7dSJohannes Thumshirn struct request_queue *q = bio->bi_bdev->bd_disk->queue; 10567de55b7dSJohannes Thumshirn struct iov_iter i = *iter; 10577de55b7dSJohannes Thumshirn 10587de55b7dSJohannes Thumshirn iov_iter_truncate(&i, queue_max_zone_append_sectors(q) << 9); 10597de55b7dSJohannes Thumshirn __bio_iov_bvec_set(bio, &i); 10607de55b7dSJohannes Thumshirn iov_iter_advance(iter, i.count); 10617de55b7dSJohannes Thumshirn return 0; 10627de55b7dSJohannes Thumshirn } 10637de55b7dSJohannes Thumshirn 1064d9cf3bd5SPavel Begunkov static void bio_put_pages(struct page **pages, size_t size, size_t off) 1065d9cf3bd5SPavel Begunkov { 1066d9cf3bd5SPavel Begunkov size_t i, nr = DIV_ROUND_UP(size + (off & ~PAGE_MASK), PAGE_SIZE); 1067d9cf3bd5SPavel Begunkov 1068d9cf3bd5SPavel Begunkov for (i = 0; i < nr; i++) 1069d9cf3bd5SPavel Begunkov put_page(pages[i]); 1070d9cf3bd5SPavel Begunkov } 1071d9cf3bd5SPavel Begunkov 1072576ed913SChristoph Hellwig #define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *)) 1073576ed913SChristoph Hellwig 10742cefe4dbSKent Overstreet /** 107517d51b10SMartin Wilck * __bio_iov_iter_get_pages - pin user or kernel pages and add them to a bio 10762cefe4dbSKent Overstreet * @bio: bio to add pages to 10772cefe4dbSKent Overstreet * @iter: iov iterator describing the region to be mapped 10782cefe4dbSKent Overstreet * 107917d51b10SMartin Wilck * Pins pages from *iter and appends them to @bio's bvec array. The 10802cefe4dbSKent Overstreet * pages will have to be released using put_page() when done. 108117d51b10SMartin Wilck * For multi-segment *iter, this function only adds pages from the 10823cf14889SRandy Dunlap * next non-empty segment of the iov iterator. 10832cefe4dbSKent Overstreet */ 108417d51b10SMartin Wilck static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 10852cefe4dbSKent Overstreet { 1086576ed913SChristoph Hellwig unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt; 1087576ed913SChristoph Hellwig unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt; 10882cefe4dbSKent Overstreet struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt; 10892cefe4dbSKent Overstreet struct page **pages = (struct page **)bv; 109045691804SChristoph Hellwig bool same_page = false; 1091576ed913SChristoph Hellwig ssize_t size, left; 1092576ed913SChristoph Hellwig unsigned len, i; 1093b403ea24SMartin Wilck size_t offset; 1094576ed913SChristoph Hellwig 1095576ed913SChristoph Hellwig /* 1096576ed913SChristoph Hellwig * Move page array up in the allocated memory for the bio vecs as far as 1097576ed913SChristoph Hellwig * possible so that we can start filling biovecs from the beginning 1098576ed913SChristoph Hellwig * without overwriting the temporary page array. 1099576ed913SChristoph Hellwig */ 1100576ed913SChristoph Hellwig BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2); 1101576ed913SChristoph Hellwig pages += entries_left * (PAGE_PTRS_PER_BVEC - 1); 11022cefe4dbSKent Overstreet 110335c820e7SJens Axboe size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset); 11042cefe4dbSKent Overstreet if (unlikely(size <= 0)) 11052cefe4dbSKent Overstreet return size ? size : -EFAULT; 11062cefe4dbSKent Overstreet 1107576ed913SChristoph Hellwig for (left = size, i = 0; left > 0; left -= len, i++) { 1108576ed913SChristoph Hellwig struct page *page = pages[i]; 11092cefe4dbSKent Overstreet 1110576ed913SChristoph Hellwig len = min_t(size_t, PAGE_SIZE - offset, left); 111145691804SChristoph Hellwig 111245691804SChristoph Hellwig if (__bio_try_merge_page(bio, page, len, offset, &same_page)) { 111345691804SChristoph Hellwig if (same_page) 111445691804SChristoph Hellwig put_page(page); 111545691804SChristoph Hellwig } else { 1116d9cf3bd5SPavel Begunkov if (WARN_ON_ONCE(bio_full(bio, len))) { 1117d9cf3bd5SPavel Begunkov bio_put_pages(pages + i, left, offset); 1118576ed913SChristoph Hellwig return -EINVAL; 1119d9cf3bd5SPavel Begunkov } 112045691804SChristoph Hellwig __bio_add_page(bio, page, len, offset); 112145691804SChristoph Hellwig } 1122576ed913SChristoph Hellwig offset = 0; 11232cefe4dbSKent Overstreet } 11242cefe4dbSKent Overstreet 11252cefe4dbSKent Overstreet iov_iter_advance(iter, size); 11262cefe4dbSKent Overstreet return 0; 11272cefe4dbSKent Overstreet } 112817d51b10SMartin Wilck 11290512a75bSKeith Busch static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter) 11300512a75bSKeith Busch { 11310512a75bSKeith Busch unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt; 11320512a75bSKeith Busch unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt; 1133309dca30SChristoph Hellwig struct request_queue *q = bio->bi_bdev->bd_disk->queue; 11340512a75bSKeith Busch unsigned int max_append_sectors = queue_max_zone_append_sectors(q); 11350512a75bSKeith Busch struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt; 11360512a75bSKeith Busch struct page **pages = (struct page **)bv; 11370512a75bSKeith Busch ssize_t size, left; 11380512a75bSKeith Busch unsigned len, i; 11390512a75bSKeith Busch size_t offset; 11404977d121SNaohiro Aota int ret = 0; 11410512a75bSKeith Busch 11420512a75bSKeith Busch if (WARN_ON_ONCE(!max_append_sectors)) 11430512a75bSKeith Busch return 0; 11440512a75bSKeith Busch 11450512a75bSKeith Busch /* 11460512a75bSKeith Busch * Move page array up in the allocated memory for the bio vecs as far as 11470512a75bSKeith Busch * possible so that we can start filling biovecs from the beginning 11480512a75bSKeith Busch * without overwriting the temporary page array. 11490512a75bSKeith Busch */ 11500512a75bSKeith Busch BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2); 11510512a75bSKeith Busch pages += entries_left * (PAGE_PTRS_PER_BVEC - 1); 11520512a75bSKeith Busch 11530512a75bSKeith Busch size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset); 11540512a75bSKeith Busch if (unlikely(size <= 0)) 11550512a75bSKeith Busch return size ? size : -EFAULT; 11560512a75bSKeith Busch 11570512a75bSKeith Busch for (left = size, i = 0; left > 0; left -= len, i++) { 11580512a75bSKeith Busch struct page *page = pages[i]; 11590512a75bSKeith Busch bool same_page = false; 11600512a75bSKeith Busch 11610512a75bSKeith Busch len = min_t(size_t, PAGE_SIZE - offset, left); 11620512a75bSKeith Busch if (bio_add_hw_page(q, bio, page, len, offset, 11634977d121SNaohiro Aota max_append_sectors, &same_page) != len) { 1164d9cf3bd5SPavel Begunkov bio_put_pages(pages + i, left, offset); 11654977d121SNaohiro Aota ret = -EINVAL; 11664977d121SNaohiro Aota break; 11674977d121SNaohiro Aota } 11680512a75bSKeith Busch if (same_page) 11690512a75bSKeith Busch put_page(page); 11700512a75bSKeith Busch offset = 0; 11710512a75bSKeith Busch } 11720512a75bSKeith Busch 11734977d121SNaohiro Aota iov_iter_advance(iter, size - left); 11744977d121SNaohiro Aota return ret; 11750512a75bSKeith Busch } 11760512a75bSKeith Busch 117717d51b10SMartin Wilck /** 11786d0c48aeSJens Axboe * bio_iov_iter_get_pages - add user or kernel pages to a bio 117917d51b10SMartin Wilck * @bio: bio to add pages to 11806d0c48aeSJens Axboe * @iter: iov iterator describing the region to be added 118117d51b10SMartin Wilck * 11826d0c48aeSJens Axboe * This takes either an iterator pointing to user memory, or one pointing to 11836d0c48aeSJens Axboe * kernel pages (BVEC iterator). If we're adding user pages, we pin them and 11846d0c48aeSJens Axboe * map them into the kernel. On IO completion, the caller should put those 1185c42bca92SPavel Begunkov * pages. For bvec based iterators bio_iov_iter_get_pages() uses the provided 1186c42bca92SPavel Begunkov * bvecs rather than copying them. Hence anyone issuing kiocb based IO needs 1187c42bca92SPavel Begunkov * to ensure the bvecs and pages stay referenced until the submitted I/O is 1188c42bca92SPavel Begunkov * completed by a call to ->ki_complete() or returns with an error other than 1189c42bca92SPavel Begunkov * -EIOCBQUEUED. The caller needs to check if the bio is flagged BIO_NO_PAGE_REF 1190c42bca92SPavel Begunkov * on IO completion. If it isn't, then pages should be released. 11916d0c48aeSJens Axboe * 119217d51b10SMartin Wilck * The function tries, but does not guarantee, to pin as many pages as 11935cd3ddc1SMauro Carvalho Chehab * fit into the bio, or are requested in @iter, whatever is smaller. If 11946d0c48aeSJens Axboe * MM encounters an error pinning the requested pages, it stops. Error 11956d0c48aeSJens Axboe * is returned only if 0 pages could be pinned. 11960cf41e5eSPavel Begunkov * 11970cf41e5eSPavel Begunkov * It's intended for direct IO, so doesn't do PSI tracking, the caller is 11980cf41e5eSPavel Begunkov * responsible for setting BIO_WORKINGSET if necessary. 119917d51b10SMartin Wilck */ 120017d51b10SMartin Wilck int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 120117d51b10SMartin Wilck { 1202c42bca92SPavel Begunkov int ret = 0; 120314eacf12SChristoph Hellwig 1204c42bca92SPavel Begunkov if (iov_iter_is_bvec(iter)) { 12057de55b7dSJohannes Thumshirn if (bio_op(bio) == REQ_OP_ZONE_APPEND) 12067de55b7dSJohannes Thumshirn return bio_iov_bvec_set_append(bio, iter); 1207ed97ce5eSChristoph Hellwig return bio_iov_bvec_set(bio, iter); 120886004515SChristoph Hellwig } 120917d51b10SMartin Wilck 121017d51b10SMartin Wilck do { 1211c42bca92SPavel Begunkov if (bio_op(bio) == REQ_OP_ZONE_APPEND) 12120512a75bSKeith Busch ret = __bio_iov_append_get_pages(bio, iter); 12136d0c48aeSJens Axboe else 12146d0c48aeSJens Axboe ret = __bio_iov_iter_get_pages(bio, iter); 121579d08f89SMing Lei } while (!ret && iov_iter_count(iter) && !bio_full(bio, 0)); 121617d51b10SMartin Wilck 12170cf41e5eSPavel Begunkov /* don't account direct I/O as memory stall */ 12180cf41e5eSPavel Begunkov bio_clear_flag(bio, BIO_WORKINGSET); 121914eacf12SChristoph Hellwig return bio->bi_vcnt ? 0 : ret; 122017d51b10SMartin Wilck } 122129b2a3aaSJohannes Thumshirn EXPORT_SYMBOL_GPL(bio_iov_iter_get_pages); 12222cefe4dbSKent Overstreet 12234246a0b6SChristoph Hellwig static void submit_bio_wait_endio(struct bio *bio) 1224f9c78b2bSJens Axboe { 122565e53aabSChristoph Hellwig complete(bio->bi_private); 1226f9c78b2bSJens Axboe } 1227f9c78b2bSJens Axboe 1228f9c78b2bSJens Axboe /** 1229f9c78b2bSJens Axboe * submit_bio_wait - submit a bio, and wait until it completes 1230f9c78b2bSJens Axboe * @bio: The &struct bio which describes the I/O 1231f9c78b2bSJens Axboe * 1232f9c78b2bSJens Axboe * Simple wrapper around submit_bio(). Returns 0 on success, or the error from 1233f9c78b2bSJens Axboe * bio_endio() on failure. 12343d289d68SJan Kara * 12353d289d68SJan Kara * WARNING: Unlike to how submit_bio() is usually used, this function does not 12363d289d68SJan Kara * result in bio reference to be consumed. The caller must drop the reference 12373d289d68SJan Kara * on his own. 1238f9c78b2bSJens Axboe */ 12394e49ea4aSMike Christie int submit_bio_wait(struct bio *bio) 1240f9c78b2bSJens Axboe { 1241309dca30SChristoph Hellwig DECLARE_COMPLETION_ONSTACK_MAP(done, 1242309dca30SChristoph Hellwig bio->bi_bdev->bd_disk->lockdep_map); 1243de6a78b6SMing Lei unsigned long hang_check; 1244f9c78b2bSJens Axboe 124565e53aabSChristoph Hellwig bio->bi_private = &done; 1246f9c78b2bSJens Axboe bio->bi_end_io = submit_bio_wait_endio; 12471eff9d32SJens Axboe bio->bi_opf |= REQ_SYNC; 12484e49ea4aSMike Christie submit_bio(bio); 1249de6a78b6SMing Lei 1250de6a78b6SMing Lei /* Prevent hang_check timer from firing at us during very long I/O */ 1251de6a78b6SMing Lei hang_check = sysctl_hung_task_timeout_secs; 1252de6a78b6SMing Lei if (hang_check) 1253de6a78b6SMing Lei while (!wait_for_completion_io_timeout(&done, 1254de6a78b6SMing Lei hang_check * (HZ/2))) 1255de6a78b6SMing Lei ; 1256de6a78b6SMing Lei else 125765e53aabSChristoph Hellwig wait_for_completion_io(&done); 1258f9c78b2bSJens Axboe 125965e53aabSChristoph Hellwig return blk_status_to_errno(bio->bi_status); 1260f9c78b2bSJens Axboe } 1261f9c78b2bSJens Axboe EXPORT_SYMBOL(submit_bio_wait); 1262f9c78b2bSJens Axboe 1263f9c78b2bSJens Axboe /** 1264f9c78b2bSJens Axboe * bio_advance - increment/complete a bio by some number of bytes 1265f9c78b2bSJens Axboe * @bio: bio to advance 1266f9c78b2bSJens Axboe * @bytes: number of bytes to complete 1267f9c78b2bSJens Axboe * 1268f9c78b2bSJens Axboe * This updates bi_sector, bi_size and bi_idx; if the number of bytes to 1269f9c78b2bSJens Axboe * complete doesn't align with a bvec boundary, then bv_len and bv_offset will 1270f9c78b2bSJens Axboe * be updated on the last bvec as well. 1271f9c78b2bSJens Axboe * 1272f9c78b2bSJens Axboe * @bio will then represent the remaining, uncompleted portion of the io. 1273f9c78b2bSJens Axboe */ 1274f9c78b2bSJens Axboe void bio_advance(struct bio *bio, unsigned bytes) 1275f9c78b2bSJens Axboe { 1276f9c78b2bSJens Axboe if (bio_integrity(bio)) 1277f9c78b2bSJens Axboe bio_integrity_advance(bio, bytes); 1278f9c78b2bSJens Axboe 1279a892c8d5SSatya Tangirala bio_crypt_advance(bio, bytes); 1280f9c78b2bSJens Axboe bio_advance_iter(bio, &bio->bi_iter, bytes); 1281f9c78b2bSJens Axboe } 1282f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_advance); 1283f9c78b2bSJens Axboe 128445db54d5SKent Overstreet void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter, 128545db54d5SKent Overstreet struct bio *src, struct bvec_iter *src_iter) 1286f9c78b2bSJens Axboe { 128745db54d5SKent Overstreet while (src_iter->bi_size && dst_iter->bi_size) { 1288f8b679a0SChristoph Hellwig struct bio_vec src_bv = bio_iter_iovec(src, *src_iter); 1289f8b679a0SChristoph Hellwig struct bio_vec dst_bv = bio_iter_iovec(dst, *dst_iter); 1290f8b679a0SChristoph Hellwig unsigned int bytes = min(src_bv.bv_len, dst_bv.bv_len); 1291f8b679a0SChristoph Hellwig void *src_buf; 129245db54d5SKent Overstreet 1293f8b679a0SChristoph Hellwig src_buf = bvec_kmap_local(&src_bv); 1294f8b679a0SChristoph Hellwig memcpy_to_bvec(&dst_bv, src_buf); 1295f8b679a0SChristoph Hellwig kunmap_local(src_buf); 12966e6e811dSKent Overstreet 129722b56c29SPavel Begunkov bio_advance_iter_single(src, src_iter, bytes); 129822b56c29SPavel Begunkov bio_advance_iter_single(dst, dst_iter, bytes); 129945db54d5SKent Overstreet } 130045db54d5SKent Overstreet } 130145db54d5SKent Overstreet EXPORT_SYMBOL(bio_copy_data_iter); 130245db54d5SKent Overstreet 130345db54d5SKent Overstreet /** 130445db54d5SKent Overstreet * bio_copy_data - copy contents of data buffers from one bio to another 130545db54d5SKent Overstreet * @src: source bio 130645db54d5SKent Overstreet * @dst: destination bio 130745db54d5SKent Overstreet * 130845db54d5SKent Overstreet * Stops when it reaches the end of either @src or @dst - that is, copies 130945db54d5SKent Overstreet * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios). 131045db54d5SKent Overstreet */ 131145db54d5SKent Overstreet void bio_copy_data(struct bio *dst, struct bio *src) 131245db54d5SKent Overstreet { 131345db54d5SKent Overstreet struct bvec_iter src_iter = src->bi_iter; 131445db54d5SKent Overstreet struct bvec_iter dst_iter = dst->bi_iter; 131545db54d5SKent Overstreet 131645db54d5SKent Overstreet bio_copy_data_iter(dst, &dst_iter, src, &src_iter); 131745db54d5SKent Overstreet } 131845db54d5SKent Overstreet EXPORT_SYMBOL(bio_copy_data); 131945db54d5SKent Overstreet 1320491221f8SGuoqing Jiang void bio_free_pages(struct bio *bio) 13211dfa0f68SChristoph Hellwig { 13221dfa0f68SChristoph Hellwig struct bio_vec *bvec; 13236dc4f100SMing Lei struct bvec_iter_all iter_all; 13241dfa0f68SChristoph Hellwig 13252b070cfeSChristoph Hellwig bio_for_each_segment_all(bvec, bio, iter_all) 13261dfa0f68SChristoph Hellwig __free_page(bvec->bv_page); 13271dfa0f68SChristoph Hellwig } 1328491221f8SGuoqing Jiang EXPORT_SYMBOL(bio_free_pages); 13291dfa0f68SChristoph Hellwig 1330f9c78b2bSJens Axboe /* 1331f9c78b2bSJens Axboe * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions 1332f9c78b2bSJens Axboe * for performing direct-IO in BIOs. 1333f9c78b2bSJens Axboe * 1334f9c78b2bSJens Axboe * The problem is that we cannot run set_page_dirty() from interrupt context 1335f9c78b2bSJens Axboe * because the required locks are not interrupt-safe. So what we can do is to 1336f9c78b2bSJens Axboe * mark the pages dirty _before_ performing IO. And in interrupt context, 1337f9c78b2bSJens Axboe * check that the pages are still dirty. If so, fine. If not, redirty them 1338f9c78b2bSJens Axboe * in process context. 1339f9c78b2bSJens Axboe * 1340f9c78b2bSJens Axboe * We special-case compound pages here: normally this means reads into hugetlb 1341f9c78b2bSJens Axboe * pages. The logic in here doesn't really work right for compound pages 1342f9c78b2bSJens Axboe * because the VM does not uniformly chase down the head page in all cases. 1343f9c78b2bSJens Axboe * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't 1344f9c78b2bSJens Axboe * handle them at all. So we skip compound pages here at an early stage. 1345f9c78b2bSJens Axboe * 1346f9c78b2bSJens Axboe * Note that this code is very hard to test under normal circumstances because 1347f9c78b2bSJens Axboe * direct-io pins the pages with get_user_pages(). This makes 1348f9c78b2bSJens Axboe * is_page_cache_freeable return false, and the VM will not clean the pages. 1349f9c78b2bSJens Axboe * But other code (eg, flusher threads) could clean the pages if they are mapped 1350f9c78b2bSJens Axboe * pagecache. 1351f9c78b2bSJens Axboe * 1352f9c78b2bSJens Axboe * Simply disabling the call to bio_set_pages_dirty() is a good way to test the 1353f9c78b2bSJens Axboe * deferred bio dirtying paths. 1354f9c78b2bSJens Axboe */ 1355f9c78b2bSJens Axboe 1356f9c78b2bSJens Axboe /* 1357f9c78b2bSJens Axboe * bio_set_pages_dirty() will mark all the bio's pages as dirty. 1358f9c78b2bSJens Axboe */ 1359f9c78b2bSJens Axboe void bio_set_pages_dirty(struct bio *bio) 1360f9c78b2bSJens Axboe { 1361f9c78b2bSJens Axboe struct bio_vec *bvec; 13626dc4f100SMing Lei struct bvec_iter_all iter_all; 1363f9c78b2bSJens Axboe 13642b070cfeSChristoph Hellwig bio_for_each_segment_all(bvec, bio, iter_all) { 13653bb50983SChristoph Hellwig if (!PageCompound(bvec->bv_page)) 13663bb50983SChristoph Hellwig set_page_dirty_lock(bvec->bv_page); 1367f9c78b2bSJens Axboe } 1368f9c78b2bSJens Axboe } 1369f9c78b2bSJens Axboe 1370f9c78b2bSJens Axboe /* 1371f9c78b2bSJens Axboe * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. 1372f9c78b2bSJens Axboe * If they are, then fine. If, however, some pages are clean then they must 1373f9c78b2bSJens Axboe * have been written out during the direct-IO read. So we take another ref on 137424d5493fSChristoph Hellwig * the BIO and re-dirty the pages in process context. 1375f9c78b2bSJens Axboe * 1376f9c78b2bSJens Axboe * It is expected that bio_check_pages_dirty() will wholly own the BIO from 1377ea1754a0SKirill A. Shutemov * here on. It will run one put_page() against each page and will run one 1378ea1754a0SKirill A. Shutemov * bio_put() against the BIO. 1379f9c78b2bSJens Axboe */ 1380f9c78b2bSJens Axboe 1381f9c78b2bSJens Axboe static void bio_dirty_fn(struct work_struct *work); 1382f9c78b2bSJens Axboe 1383f9c78b2bSJens Axboe static DECLARE_WORK(bio_dirty_work, bio_dirty_fn); 1384f9c78b2bSJens Axboe static DEFINE_SPINLOCK(bio_dirty_lock); 1385f9c78b2bSJens Axboe static struct bio *bio_dirty_list; 1386f9c78b2bSJens Axboe 1387f9c78b2bSJens Axboe /* 1388f9c78b2bSJens Axboe * This runs in process context 1389f9c78b2bSJens Axboe */ 1390f9c78b2bSJens Axboe static void bio_dirty_fn(struct work_struct *work) 1391f9c78b2bSJens Axboe { 139224d5493fSChristoph Hellwig struct bio *bio, *next; 1393f9c78b2bSJens Axboe 139424d5493fSChristoph Hellwig spin_lock_irq(&bio_dirty_lock); 139524d5493fSChristoph Hellwig next = bio_dirty_list; 1396f9c78b2bSJens Axboe bio_dirty_list = NULL; 139724d5493fSChristoph Hellwig spin_unlock_irq(&bio_dirty_lock); 1398f9c78b2bSJens Axboe 139924d5493fSChristoph Hellwig while ((bio = next) != NULL) { 140024d5493fSChristoph Hellwig next = bio->bi_private; 1401f9c78b2bSJens Axboe 1402d241a95fSChristoph Hellwig bio_release_pages(bio, true); 1403f9c78b2bSJens Axboe bio_put(bio); 1404f9c78b2bSJens Axboe } 1405f9c78b2bSJens Axboe } 1406f9c78b2bSJens Axboe 1407f9c78b2bSJens Axboe void bio_check_pages_dirty(struct bio *bio) 1408f9c78b2bSJens Axboe { 1409f9c78b2bSJens Axboe struct bio_vec *bvec; 141024d5493fSChristoph Hellwig unsigned long flags; 14116dc4f100SMing Lei struct bvec_iter_all iter_all; 1412f9c78b2bSJens Axboe 14132b070cfeSChristoph Hellwig bio_for_each_segment_all(bvec, bio, iter_all) { 141424d5493fSChristoph Hellwig if (!PageDirty(bvec->bv_page) && !PageCompound(bvec->bv_page)) 141524d5493fSChristoph Hellwig goto defer; 1416f9c78b2bSJens Axboe } 1417f9c78b2bSJens Axboe 1418d241a95fSChristoph Hellwig bio_release_pages(bio, false); 141924d5493fSChristoph Hellwig bio_put(bio); 142024d5493fSChristoph Hellwig return; 142124d5493fSChristoph Hellwig defer: 1422f9c78b2bSJens Axboe spin_lock_irqsave(&bio_dirty_lock, flags); 1423f9c78b2bSJens Axboe bio->bi_private = bio_dirty_list; 1424f9c78b2bSJens Axboe bio_dirty_list = bio; 1425f9c78b2bSJens Axboe spin_unlock_irqrestore(&bio_dirty_lock, flags); 1426f9c78b2bSJens Axboe schedule_work(&bio_dirty_work); 1427f9c78b2bSJens Axboe } 1428f9c78b2bSJens Axboe 1429c4cf5261SJens Axboe static inline bool bio_remaining_done(struct bio *bio) 1430c4cf5261SJens Axboe { 1431c4cf5261SJens Axboe /* 1432c4cf5261SJens Axboe * If we're not chaining, then ->__bi_remaining is always 1 and 1433c4cf5261SJens Axboe * we always end io on the first invocation. 1434c4cf5261SJens Axboe */ 1435c4cf5261SJens Axboe if (!bio_flagged(bio, BIO_CHAIN)) 1436c4cf5261SJens Axboe return true; 1437c4cf5261SJens Axboe 1438c4cf5261SJens Axboe BUG_ON(atomic_read(&bio->__bi_remaining) <= 0); 1439c4cf5261SJens Axboe 1440326e1dbbSMike Snitzer if (atomic_dec_and_test(&bio->__bi_remaining)) { 1441b7c44ed9SJens Axboe bio_clear_flag(bio, BIO_CHAIN); 1442c4cf5261SJens Axboe return true; 1443326e1dbbSMike Snitzer } 1444c4cf5261SJens Axboe 1445c4cf5261SJens Axboe return false; 1446c4cf5261SJens Axboe } 1447c4cf5261SJens Axboe 1448f9c78b2bSJens Axboe /** 1449f9c78b2bSJens Axboe * bio_endio - end I/O on a bio 1450f9c78b2bSJens Axboe * @bio: bio 1451f9c78b2bSJens Axboe * 1452f9c78b2bSJens Axboe * Description: 14534246a0b6SChristoph Hellwig * bio_endio() will end I/O on the whole bio. bio_endio() is the preferred 14544246a0b6SChristoph Hellwig * way to end I/O on a bio. No one should call bi_end_io() directly on a 14554246a0b6SChristoph Hellwig * bio unless they own it and thus know that it has an end_io function. 1456fbbaf700SNeilBrown * 1457fbbaf700SNeilBrown * bio_endio() can be called several times on a bio that has been chained 1458fbbaf700SNeilBrown * using bio_chain(). The ->bi_end_io() function will only be called the 145960b6a7e6SEdward Hsieh * last time. 1460f9c78b2bSJens Axboe **/ 14614246a0b6SChristoph Hellwig void bio_endio(struct bio *bio) 1462f9c78b2bSJens Axboe { 1463ba8c6967SChristoph Hellwig again: 14642b885517SChristoph Hellwig if (!bio_remaining_done(bio)) 1465ba8c6967SChristoph Hellwig return; 14667c20f116SChristoph Hellwig if (!bio_integrity_endio(bio)) 14677c20f116SChristoph Hellwig return; 1468f9c78b2bSJens Axboe 1469a647a524SMing Lei if (bio->bi_bdev && bio_flagged(bio, BIO_TRACKED)) 1470309dca30SChristoph Hellwig rq_qos_done_bio(bio->bi_bdev->bd_disk->queue, bio); 147167b42d0bSJosef Bacik 147260b6a7e6SEdward Hsieh if (bio->bi_bdev && bio_flagged(bio, BIO_TRACE_COMPLETION)) { 147360b6a7e6SEdward Hsieh trace_block_bio_complete(bio->bi_bdev->bd_disk->queue, bio); 147460b6a7e6SEdward Hsieh bio_clear_flag(bio, BIO_TRACE_COMPLETION); 147560b6a7e6SEdward Hsieh } 147660b6a7e6SEdward Hsieh 1477f9c78b2bSJens Axboe /* 1478ba8c6967SChristoph Hellwig * Need to have a real endio function for chained bios, otherwise 1479ba8c6967SChristoph Hellwig * various corner cases will break (like stacking block devices that 1480ba8c6967SChristoph Hellwig * save/restore bi_end_io) - however, we want to avoid unbounded 1481ba8c6967SChristoph Hellwig * recursion and blowing the stack. Tail call optimization would 1482ba8c6967SChristoph Hellwig * handle this, but compiling with frame pointers also disables 1483ba8c6967SChristoph Hellwig * gcc's sibling call optimization. 1484f9c78b2bSJens Axboe */ 1485f9c78b2bSJens Axboe if (bio->bi_end_io == bio_chain_endio) { 148638f8baaeSChristoph Hellwig bio = __bio_chain_endio(bio); 1487ba8c6967SChristoph Hellwig goto again; 1488ba8c6967SChristoph Hellwig } 1489ba8c6967SChristoph Hellwig 14909e234eeaSShaohua Li blk_throtl_bio_endio(bio); 1491b222dd2fSShaohua Li /* release cgroup info */ 1492b222dd2fSShaohua Li bio_uninit(bio); 1493f9c78b2bSJens Axboe if (bio->bi_end_io) 14944246a0b6SChristoph Hellwig bio->bi_end_io(bio); 1495f9c78b2bSJens Axboe } 1496f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_endio); 1497f9c78b2bSJens Axboe 1498f9c78b2bSJens Axboe /** 1499f9c78b2bSJens Axboe * bio_split - split a bio 1500f9c78b2bSJens Axboe * @bio: bio to split 1501f9c78b2bSJens Axboe * @sectors: number of sectors to split from the front of @bio 1502f9c78b2bSJens Axboe * @gfp: gfp mask 1503f9c78b2bSJens Axboe * @bs: bio set to allocate from 1504f9c78b2bSJens Axboe * 1505f9c78b2bSJens Axboe * Allocates and returns a new bio which represents @sectors from the start of 1506f9c78b2bSJens Axboe * @bio, and updates @bio to represent the remaining sectors. 1507f9c78b2bSJens Axboe * 1508f3f5da62SMartin K. Petersen * Unless this is a discard request the newly allocated bio will point 1509dad77584SBart Van Assche * to @bio's bi_io_vec. It is the caller's responsibility to ensure that 1510dad77584SBart Van Assche * neither @bio nor @bs are freed before the split bio. 1511f9c78b2bSJens Axboe */ 1512f9c78b2bSJens Axboe struct bio *bio_split(struct bio *bio, int sectors, 1513f9c78b2bSJens Axboe gfp_t gfp, struct bio_set *bs) 1514f9c78b2bSJens Axboe { 1515f341a4d3SMikulas Patocka struct bio *split; 1516f9c78b2bSJens Axboe 1517f9c78b2bSJens Axboe BUG_ON(sectors <= 0); 1518f9c78b2bSJens Axboe BUG_ON(sectors >= bio_sectors(bio)); 1519f9c78b2bSJens Axboe 15200512a75bSKeith Busch /* Zone append commands cannot be split */ 15210512a75bSKeith Busch if (WARN_ON_ONCE(bio_op(bio) == REQ_OP_ZONE_APPEND)) 15220512a75bSKeith Busch return NULL; 15230512a75bSKeith Busch 1524f9c78b2bSJens Axboe split = bio_clone_fast(bio, gfp, bs); 1525f9c78b2bSJens Axboe if (!split) 1526f9c78b2bSJens Axboe return NULL; 1527f9c78b2bSJens Axboe 1528f9c78b2bSJens Axboe split->bi_iter.bi_size = sectors << 9; 1529f9c78b2bSJens Axboe 1530f9c78b2bSJens Axboe if (bio_integrity(split)) 1531fbd08e76SDmitry Monakhov bio_integrity_trim(split); 1532f9c78b2bSJens Axboe 1533f9c78b2bSJens Axboe bio_advance(bio, split->bi_iter.bi_size); 1534f9c78b2bSJens Axboe 1535fbbaf700SNeilBrown if (bio_flagged(bio, BIO_TRACE_COMPLETION)) 153620d59023SGoldwyn Rodrigues bio_set_flag(split, BIO_TRACE_COMPLETION); 1537fbbaf700SNeilBrown 1538f9c78b2bSJens Axboe return split; 1539f9c78b2bSJens Axboe } 1540f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_split); 1541f9c78b2bSJens Axboe 1542f9c78b2bSJens Axboe /** 1543f9c78b2bSJens Axboe * bio_trim - trim a bio 1544f9c78b2bSJens Axboe * @bio: bio to trim 1545f9c78b2bSJens Axboe * @offset: number of sectors to trim from the front of @bio 1546f9c78b2bSJens Axboe * @size: size we want to trim @bio to, in sectors 1547e83502caSChaitanya Kulkarni * 1548e83502caSChaitanya Kulkarni * This function is typically used for bios that are cloned and submitted 1549e83502caSChaitanya Kulkarni * to the underlying device in parts. 1550f9c78b2bSJens Axboe */ 1551e83502caSChaitanya Kulkarni void bio_trim(struct bio *bio, sector_t offset, sector_t size) 1552f9c78b2bSJens Axboe { 1553e83502caSChaitanya Kulkarni if (WARN_ON_ONCE(offset > BIO_MAX_SECTORS || size > BIO_MAX_SECTORS || 1554e83502caSChaitanya Kulkarni offset + size > bio->bi_iter.bi_size)) 1555e83502caSChaitanya Kulkarni return; 1556f9c78b2bSJens Axboe 1557f9c78b2bSJens Axboe size <<= 9; 1558f9c78b2bSJens Axboe if (offset == 0 && size == bio->bi_iter.bi_size) 1559f9c78b2bSJens Axboe return; 1560f9c78b2bSJens Axboe 1561f9c78b2bSJens Axboe bio_advance(bio, offset << 9); 1562f9c78b2bSJens Axboe bio->bi_iter.bi_size = size; 1563376a78abSDmitry Monakhov 1564376a78abSDmitry Monakhov if (bio_integrity(bio)) 1565fbd08e76SDmitry Monakhov bio_integrity_trim(bio); 1566f9c78b2bSJens Axboe } 1567f9c78b2bSJens Axboe EXPORT_SYMBOL_GPL(bio_trim); 1568f9c78b2bSJens Axboe 1569f9c78b2bSJens Axboe /* 1570f9c78b2bSJens Axboe * create memory pools for biovec's in a bio_set. 1571f9c78b2bSJens Axboe * use the global biovec slabs created for general use. 1572f9c78b2bSJens Axboe */ 15738aa6ba2fSKent Overstreet int biovec_init_pool(mempool_t *pool, int pool_entries) 1574f9c78b2bSJens Axboe { 15757a800a20SChristoph Hellwig struct biovec_slab *bp = bvec_slabs + ARRAY_SIZE(bvec_slabs) - 1; 1576f9c78b2bSJens Axboe 15778aa6ba2fSKent Overstreet return mempool_init_slab_pool(pool, pool_entries, bp->slab); 1578f9c78b2bSJens Axboe } 1579f9c78b2bSJens Axboe 1580917a38c7SKent Overstreet /* 1581917a38c7SKent Overstreet * bioset_exit - exit a bioset initialized with bioset_init() 1582917a38c7SKent Overstreet * 1583917a38c7SKent Overstreet * May be called on a zeroed but uninitialized bioset (i.e. allocated with 1584917a38c7SKent Overstreet * kzalloc()). 1585917a38c7SKent Overstreet */ 1586917a38c7SKent Overstreet void bioset_exit(struct bio_set *bs) 1587f9c78b2bSJens Axboe { 1588be4d234dSJens Axboe bio_alloc_cache_destroy(bs); 1589f9c78b2bSJens Axboe if (bs->rescue_workqueue) 1590f9c78b2bSJens Axboe destroy_workqueue(bs->rescue_workqueue); 1591917a38c7SKent Overstreet bs->rescue_workqueue = NULL; 1592f9c78b2bSJens Axboe 15938aa6ba2fSKent Overstreet mempool_exit(&bs->bio_pool); 15948aa6ba2fSKent Overstreet mempool_exit(&bs->bvec_pool); 1595f9c78b2bSJens Axboe 1596f9c78b2bSJens Axboe bioset_integrity_free(bs); 1597917a38c7SKent Overstreet if (bs->bio_slab) 1598f9c78b2bSJens Axboe bio_put_slab(bs); 1599917a38c7SKent Overstreet bs->bio_slab = NULL; 1600917a38c7SKent Overstreet } 1601917a38c7SKent Overstreet EXPORT_SYMBOL(bioset_exit); 1602f9c78b2bSJens Axboe 1603011067b0SNeilBrown /** 1604917a38c7SKent Overstreet * bioset_init - Initialize a bio_set 1605dad08527SKent Overstreet * @bs: pool to initialize 1606917a38c7SKent Overstreet * @pool_size: Number of bio and bio_vecs to cache in the mempool 1607917a38c7SKent Overstreet * @front_pad: Number of bytes to allocate in front of the returned bio 1608917a38c7SKent Overstreet * @flags: Flags to modify behavior, currently %BIOSET_NEED_BVECS 1609917a38c7SKent Overstreet * and %BIOSET_NEED_RESCUER 1610917a38c7SKent Overstreet * 1611dad08527SKent Overstreet * Description: 1612dad08527SKent Overstreet * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller 1613dad08527SKent Overstreet * to ask for a number of bytes to be allocated in front of the bio. 1614dad08527SKent Overstreet * Front pad allocation is useful for embedding the bio inside 1615dad08527SKent Overstreet * another structure, to avoid allocating extra data to go with the bio. 1616dad08527SKent Overstreet * Note that the bio must be embedded at the END of that structure always, 1617dad08527SKent Overstreet * or things will break badly. 1618dad08527SKent Overstreet * If %BIOSET_NEED_BVECS is set in @flags, a separate pool will be allocated 1619dad08527SKent Overstreet * for allocating iovecs. This pool is not needed e.g. for bio_clone_fast(). 1620dad08527SKent Overstreet * If %BIOSET_NEED_RESCUER is set, a workqueue is created which can be used to 1621dad08527SKent Overstreet * dispatch queued requests when the mempool runs out of space. 1622dad08527SKent Overstreet * 1623917a38c7SKent Overstreet */ 1624917a38c7SKent Overstreet int bioset_init(struct bio_set *bs, 1625917a38c7SKent Overstreet unsigned int pool_size, 1626917a38c7SKent Overstreet unsigned int front_pad, 1627917a38c7SKent Overstreet int flags) 1628917a38c7SKent Overstreet { 1629917a38c7SKent Overstreet bs->front_pad = front_pad; 16309f180e31SMing Lei if (flags & BIOSET_NEED_BVECS) 16319f180e31SMing Lei bs->back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec); 16329f180e31SMing Lei else 16339f180e31SMing Lei bs->back_pad = 0; 1634917a38c7SKent Overstreet 1635917a38c7SKent Overstreet spin_lock_init(&bs->rescue_lock); 1636917a38c7SKent Overstreet bio_list_init(&bs->rescue_list); 1637917a38c7SKent Overstreet INIT_WORK(&bs->rescue_work, bio_alloc_rescue); 1638917a38c7SKent Overstreet 163949d1ec85SMing Lei bs->bio_slab = bio_find_or_create_slab(bs); 1640917a38c7SKent Overstreet if (!bs->bio_slab) 1641917a38c7SKent Overstreet return -ENOMEM; 1642917a38c7SKent Overstreet 1643917a38c7SKent Overstreet if (mempool_init_slab_pool(&bs->bio_pool, pool_size, bs->bio_slab)) 1644917a38c7SKent Overstreet goto bad; 1645917a38c7SKent Overstreet 1646917a38c7SKent Overstreet if ((flags & BIOSET_NEED_BVECS) && 1647917a38c7SKent Overstreet biovec_init_pool(&bs->bvec_pool, pool_size)) 1648917a38c7SKent Overstreet goto bad; 1649917a38c7SKent Overstreet 1650be4d234dSJens Axboe if (flags & BIOSET_NEED_RESCUER) { 1651be4d234dSJens Axboe bs->rescue_workqueue = alloc_workqueue("bioset", 1652be4d234dSJens Axboe WQ_MEM_RECLAIM, 0); 1653917a38c7SKent Overstreet if (!bs->rescue_workqueue) 1654917a38c7SKent Overstreet goto bad; 1655be4d234dSJens Axboe } 1656be4d234dSJens Axboe if (flags & BIOSET_PERCPU_CACHE) { 1657be4d234dSJens Axboe bs->cache = alloc_percpu(struct bio_alloc_cache); 1658be4d234dSJens Axboe if (!bs->cache) 1659be4d234dSJens Axboe goto bad; 1660be4d234dSJens Axboe cpuhp_state_add_instance_nocalls(CPUHP_BIO_DEAD, &bs->cpuhp_dead); 1661be4d234dSJens Axboe } 1662917a38c7SKent Overstreet 1663917a38c7SKent Overstreet return 0; 1664917a38c7SKent Overstreet bad: 1665917a38c7SKent Overstreet bioset_exit(bs); 1666917a38c7SKent Overstreet return -ENOMEM; 1667917a38c7SKent Overstreet } 1668917a38c7SKent Overstreet EXPORT_SYMBOL(bioset_init); 1669917a38c7SKent Overstreet 167028e89fd9SJens Axboe /* 167128e89fd9SJens Axboe * Initialize and setup a new bio_set, based on the settings from 167228e89fd9SJens Axboe * another bio_set. 167328e89fd9SJens Axboe */ 167428e89fd9SJens Axboe int bioset_init_from_src(struct bio_set *bs, struct bio_set *src) 167528e89fd9SJens Axboe { 167628e89fd9SJens Axboe int flags; 167728e89fd9SJens Axboe 167828e89fd9SJens Axboe flags = 0; 167928e89fd9SJens Axboe if (src->bvec_pool.min_nr) 168028e89fd9SJens Axboe flags |= BIOSET_NEED_BVECS; 168128e89fd9SJens Axboe if (src->rescue_workqueue) 168228e89fd9SJens Axboe flags |= BIOSET_NEED_RESCUER; 168328e89fd9SJens Axboe 168428e89fd9SJens Axboe return bioset_init(bs, src->bio_pool.min_nr, src->front_pad, flags); 168528e89fd9SJens Axboe } 168628e89fd9SJens Axboe EXPORT_SYMBOL(bioset_init_from_src); 168728e89fd9SJens Axboe 1688be4d234dSJens Axboe /** 1689be4d234dSJens Axboe * bio_alloc_kiocb - Allocate a bio from bio_set based on kiocb 1690be4d234dSJens Axboe * @kiocb: kiocb describing the IO 16910ef47db1SJens Axboe * @nr_vecs: number of iovecs to pre-allocate 1692be4d234dSJens Axboe * @bs: bio_set to allocate from 1693be4d234dSJens Axboe * 1694be4d234dSJens Axboe * Description: 1695be4d234dSJens Axboe * Like @bio_alloc_bioset, but pass in the kiocb. The kiocb is only 1696be4d234dSJens Axboe * used to check if we should dip into the per-cpu bio_set allocation 16973d5b3fbeSJens Axboe * cache. The allocation uses GFP_KERNEL internally. On return, the 16983d5b3fbeSJens Axboe * bio is marked BIO_PERCPU_CACHEABLE, and the final put of the bio 16993d5b3fbeSJens Axboe * MUST be done from process context, not hard/soft IRQ. 1700be4d234dSJens Axboe * 1701be4d234dSJens Axboe */ 1702be4d234dSJens Axboe struct bio *bio_alloc_kiocb(struct kiocb *kiocb, unsigned short nr_vecs, 1703be4d234dSJens Axboe struct bio_set *bs) 1704be4d234dSJens Axboe { 1705be4d234dSJens Axboe struct bio_alloc_cache *cache; 1706be4d234dSJens Axboe struct bio *bio; 1707be4d234dSJens Axboe 1708be4d234dSJens Axboe if (!(kiocb->ki_flags & IOCB_ALLOC_CACHE) || nr_vecs > BIO_INLINE_VECS) 1709be4d234dSJens Axboe return bio_alloc_bioset(GFP_KERNEL, nr_vecs, bs); 1710be4d234dSJens Axboe 1711be4d234dSJens Axboe cache = per_cpu_ptr(bs->cache, get_cpu()); 1712be4d234dSJens Axboe bio = bio_list_pop(&cache->free_list); 1713be4d234dSJens Axboe if (bio) { 1714be4d234dSJens Axboe cache->nr--; 1715be4d234dSJens Axboe put_cpu(); 1716be4d234dSJens Axboe bio_init(bio, nr_vecs ? bio->bi_inline_vecs : NULL, nr_vecs); 1717be4d234dSJens Axboe bio->bi_pool = bs; 1718be4d234dSJens Axboe bio_set_flag(bio, BIO_PERCPU_CACHE); 1719be4d234dSJens Axboe return bio; 1720be4d234dSJens Axboe } 1721be4d234dSJens Axboe put_cpu(); 1722be4d234dSJens Axboe bio = bio_alloc_bioset(GFP_KERNEL, nr_vecs, bs); 1723be4d234dSJens Axboe bio_set_flag(bio, BIO_PERCPU_CACHE); 1724be4d234dSJens Axboe return bio; 1725be4d234dSJens Axboe } 1726be4d234dSJens Axboe EXPORT_SYMBOL_GPL(bio_alloc_kiocb); 1727be4d234dSJens Axboe 1728de76fd89SChristoph Hellwig static int __init init_bio(void) 1729f9c78b2bSJens Axboe { 1730f9c78b2bSJens Axboe int i; 1731f9c78b2bSJens Axboe 1732f9c78b2bSJens Axboe bio_integrity_init(); 1733de76fd89SChristoph Hellwig 1734de76fd89SChristoph Hellwig for (i = 0; i < ARRAY_SIZE(bvec_slabs); i++) { 1735f9c78b2bSJens Axboe struct biovec_slab *bvs = bvec_slabs + i; 1736f9c78b2bSJens Axboe 1737de76fd89SChristoph Hellwig bvs->slab = kmem_cache_create(bvs->name, 1738de76fd89SChristoph Hellwig bvs->nr_vecs * sizeof(struct bio_vec), 0, 1739f9c78b2bSJens Axboe SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); 1740f9c78b2bSJens Axboe } 1741f9c78b2bSJens Axboe 1742be4d234dSJens Axboe cpuhp_setup_state_multi(CPUHP_BIO_DEAD, "block/bio:dead", NULL, 1743be4d234dSJens Axboe bio_cpu_dead); 1744be4d234dSJens Axboe 1745f4f8154aSKent Overstreet if (bioset_init(&fs_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS)) 1746f9c78b2bSJens Axboe panic("bio: can't allocate bios\n"); 1747f9c78b2bSJens Axboe 1748f4f8154aSKent Overstreet if (bioset_integrity_create(&fs_bio_set, BIO_POOL_SIZE)) 1749f9c78b2bSJens Axboe panic("bio: can't create integrity pool\n"); 1750f9c78b2bSJens Axboe 1751f9c78b2bSJens Axboe return 0; 1752f9c78b2bSJens Axboe } 1753f9c78b2bSJens Axboe subsys_initcall(init_bio); 1754