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 28de76fd89SChristoph Hellwig static struct biovec_slab { 296ac0b715SChristoph Hellwig int nr_vecs; 306ac0b715SChristoph Hellwig char *name; 316ac0b715SChristoph Hellwig struct kmem_cache *slab; 32de76fd89SChristoph Hellwig } bvec_slabs[] __read_mostly = { 33de76fd89SChristoph Hellwig { .nr_vecs = 16, .name = "biovec-16" }, 34de76fd89SChristoph Hellwig { .nr_vecs = 64, .name = "biovec-64" }, 35de76fd89SChristoph Hellwig { .nr_vecs = 128, .name = "biovec-128" }, 36a8affc03SChristoph Hellwig { .nr_vecs = BIO_MAX_VECS, .name = "biovec-max" }, 37f9c78b2bSJens Axboe }; 386ac0b715SChristoph Hellwig 397a800a20SChristoph Hellwig static struct biovec_slab *biovec_slab(unsigned short nr_vecs) 407a800a20SChristoph Hellwig { 417a800a20SChristoph Hellwig switch (nr_vecs) { 427a800a20SChristoph Hellwig /* smaller bios use inline vecs */ 437a800a20SChristoph Hellwig case 5 ... 16: 447a800a20SChristoph Hellwig return &bvec_slabs[0]; 457a800a20SChristoph Hellwig case 17 ... 64: 467a800a20SChristoph Hellwig return &bvec_slabs[1]; 477a800a20SChristoph Hellwig case 65 ... 128: 487a800a20SChristoph Hellwig return &bvec_slabs[2]; 49a8affc03SChristoph Hellwig case 129 ... BIO_MAX_VECS: 507a800a20SChristoph Hellwig return &bvec_slabs[3]; 517a800a20SChristoph Hellwig default: 527a800a20SChristoph Hellwig BUG(); 537a800a20SChristoph Hellwig return NULL; 547a800a20SChristoph Hellwig } 557a800a20SChristoph Hellwig } 56f9c78b2bSJens Axboe 57f9c78b2bSJens Axboe /* 58f9c78b2bSJens Axboe * fs_bio_set is the bio_set containing bio and iovec memory pools used by 59f9c78b2bSJens Axboe * IO code that does not need private memory pools. 60f9c78b2bSJens Axboe */ 61f4f8154aSKent Overstreet struct bio_set fs_bio_set; 62f9c78b2bSJens Axboe EXPORT_SYMBOL(fs_bio_set); 63f9c78b2bSJens Axboe 64f9c78b2bSJens Axboe /* 65f9c78b2bSJens Axboe * Our slab pool management 66f9c78b2bSJens Axboe */ 67f9c78b2bSJens Axboe struct bio_slab { 68f9c78b2bSJens Axboe struct kmem_cache *slab; 69f9c78b2bSJens Axboe unsigned int slab_ref; 70f9c78b2bSJens Axboe unsigned int slab_size; 71f9c78b2bSJens Axboe char name[8]; 72f9c78b2bSJens Axboe }; 73f9c78b2bSJens Axboe static DEFINE_MUTEX(bio_slab_lock); 7449d1ec85SMing Lei static DEFINE_XARRAY(bio_slabs); 75f9c78b2bSJens Axboe 7649d1ec85SMing Lei static struct bio_slab *create_bio_slab(unsigned int size) 77f9c78b2bSJens Axboe { 7849d1ec85SMing Lei struct bio_slab *bslab = kzalloc(sizeof(*bslab), GFP_KERNEL); 7949d1ec85SMing Lei 8049d1ec85SMing Lei if (!bslab) 8149d1ec85SMing Lei return NULL; 8249d1ec85SMing Lei 8349d1ec85SMing Lei snprintf(bslab->name, sizeof(bslab->name), "bio-%d", size); 8449d1ec85SMing Lei bslab->slab = kmem_cache_create(bslab->name, size, 8549d1ec85SMing Lei ARCH_KMALLOC_MINALIGN, SLAB_HWCACHE_ALIGN, NULL); 8649d1ec85SMing Lei if (!bslab->slab) 8749d1ec85SMing Lei goto fail_alloc_slab; 8849d1ec85SMing Lei 8949d1ec85SMing Lei bslab->slab_ref = 1; 9049d1ec85SMing Lei bslab->slab_size = size; 9149d1ec85SMing Lei 9249d1ec85SMing Lei if (!xa_err(xa_store(&bio_slabs, size, bslab, GFP_KERNEL))) 9349d1ec85SMing Lei return bslab; 9449d1ec85SMing Lei 9549d1ec85SMing Lei kmem_cache_destroy(bslab->slab); 9649d1ec85SMing Lei 9749d1ec85SMing Lei fail_alloc_slab: 9849d1ec85SMing Lei kfree(bslab); 9949d1ec85SMing Lei return NULL; 10049d1ec85SMing Lei } 10149d1ec85SMing Lei 10249d1ec85SMing Lei static inline unsigned int bs_bio_slab_size(struct bio_set *bs) 10349d1ec85SMing Lei { 1049f180e31SMing Lei return bs->front_pad + sizeof(struct bio) + bs->back_pad; 10549d1ec85SMing Lei } 10649d1ec85SMing Lei 10749d1ec85SMing Lei static struct kmem_cache *bio_find_or_create_slab(struct bio_set *bs) 10849d1ec85SMing Lei { 10949d1ec85SMing Lei unsigned int size = bs_bio_slab_size(bs); 11049d1ec85SMing Lei struct bio_slab *bslab; 111f9c78b2bSJens Axboe 112f9c78b2bSJens Axboe mutex_lock(&bio_slab_lock); 11349d1ec85SMing Lei bslab = xa_load(&bio_slabs, size); 11449d1ec85SMing Lei if (bslab) 115f9c78b2bSJens Axboe bslab->slab_ref++; 11649d1ec85SMing Lei else 11749d1ec85SMing Lei bslab = create_bio_slab(size); 118f9c78b2bSJens Axboe mutex_unlock(&bio_slab_lock); 11949d1ec85SMing Lei 12049d1ec85SMing Lei if (bslab) 12149d1ec85SMing Lei return bslab->slab; 12249d1ec85SMing Lei return NULL; 123f9c78b2bSJens Axboe } 124f9c78b2bSJens Axboe 125f9c78b2bSJens Axboe static void bio_put_slab(struct bio_set *bs) 126f9c78b2bSJens Axboe { 127f9c78b2bSJens Axboe struct bio_slab *bslab = NULL; 12849d1ec85SMing Lei unsigned int slab_size = bs_bio_slab_size(bs); 129f9c78b2bSJens Axboe 130f9c78b2bSJens Axboe mutex_lock(&bio_slab_lock); 131f9c78b2bSJens Axboe 13249d1ec85SMing Lei bslab = xa_load(&bio_slabs, slab_size); 133f9c78b2bSJens Axboe if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n")) 134f9c78b2bSJens Axboe goto out; 135f9c78b2bSJens Axboe 13649d1ec85SMing Lei WARN_ON_ONCE(bslab->slab != bs->bio_slab); 13749d1ec85SMing Lei 138f9c78b2bSJens Axboe WARN_ON(!bslab->slab_ref); 139f9c78b2bSJens Axboe 140f9c78b2bSJens Axboe if (--bslab->slab_ref) 141f9c78b2bSJens Axboe goto out; 142f9c78b2bSJens Axboe 14349d1ec85SMing Lei xa_erase(&bio_slabs, slab_size); 14449d1ec85SMing Lei 145f9c78b2bSJens Axboe kmem_cache_destroy(bslab->slab); 14649d1ec85SMing Lei kfree(bslab); 147f9c78b2bSJens Axboe 148f9c78b2bSJens Axboe out: 149f9c78b2bSJens Axboe mutex_unlock(&bio_slab_lock); 150f9c78b2bSJens Axboe } 151f9c78b2bSJens Axboe 1527a800a20SChristoph Hellwig void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs) 153f9c78b2bSJens Axboe { 154a8affc03SChristoph Hellwig BIO_BUG_ON(nr_vecs > BIO_MAX_VECS); 155f9c78b2bSJens Axboe 156a8affc03SChristoph Hellwig if (nr_vecs == BIO_MAX_VECS) 157f9c78b2bSJens Axboe mempool_free(bv, pool); 1587a800a20SChristoph Hellwig else if (nr_vecs > BIO_INLINE_VECS) 1597a800a20SChristoph Hellwig kmem_cache_free(biovec_slab(nr_vecs)->slab, bv); 160f9c78b2bSJens Axboe } 161f9c78b2bSJens Axboe 162f2c3eb9bSChristoph Hellwig /* 163f2c3eb9bSChristoph Hellwig * Make the first allocation restricted and don't dump info on allocation 164f2c3eb9bSChristoph Hellwig * failures, since we'll fall back to the mempool in case of failure. 165f2c3eb9bSChristoph Hellwig */ 166f2c3eb9bSChristoph Hellwig static inline gfp_t bvec_alloc_gfp(gfp_t gfp) 167f9c78b2bSJens Axboe { 168f2c3eb9bSChristoph Hellwig return (gfp & ~(__GFP_DIRECT_RECLAIM | __GFP_IO)) | 169f2c3eb9bSChristoph Hellwig __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; 170f2c3eb9bSChristoph Hellwig } 171f2c3eb9bSChristoph Hellwig 1727a800a20SChristoph Hellwig struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs, 1737a800a20SChristoph Hellwig gfp_t gfp_mask) 174f9c78b2bSJens Axboe { 1757a800a20SChristoph Hellwig struct biovec_slab *bvs = biovec_slab(*nr_vecs); 1767a800a20SChristoph Hellwig 1777a800a20SChristoph Hellwig if (WARN_ON_ONCE(!bvs)) 178f9c78b2bSJens Axboe return NULL; 1797a800a20SChristoph Hellwig 1807a800a20SChristoph Hellwig /* 1817a800a20SChristoph Hellwig * Upgrade the nr_vecs request to take full advantage of the allocation. 1827a800a20SChristoph Hellwig * We also rely on this in the bvec_free path. 1837a800a20SChristoph Hellwig */ 1847a800a20SChristoph Hellwig *nr_vecs = bvs->nr_vecs; 185f9c78b2bSJens Axboe 186f9c78b2bSJens Axboe /* 187f007a3d6SChristoph Hellwig * Try a slab allocation first for all smaller allocations. If that 188f007a3d6SChristoph Hellwig * fails and __GFP_DIRECT_RECLAIM is set retry with the mempool. 189a8affc03SChristoph Hellwig * The mempool is sized to handle up to BIO_MAX_VECS entries. 190f9c78b2bSJens Axboe */ 191a8affc03SChristoph Hellwig if (*nr_vecs < BIO_MAX_VECS) { 192f9c78b2bSJens Axboe struct bio_vec *bvl; 193f9c78b2bSJens Axboe 194f2c3eb9bSChristoph Hellwig bvl = kmem_cache_alloc(bvs->slab, bvec_alloc_gfp(gfp_mask)); 1957a800a20SChristoph Hellwig if (likely(bvl) || !(gfp_mask & __GFP_DIRECT_RECLAIM)) 196f9c78b2bSJens Axboe return bvl; 197a8affc03SChristoph Hellwig *nr_vecs = BIO_MAX_VECS; 198f9c78b2bSJens Axboe } 199f9c78b2bSJens Axboe 200f007a3d6SChristoph Hellwig return mempool_alloc(pool, gfp_mask); 201f9c78b2bSJens Axboe } 202f9c78b2bSJens Axboe 2039ae3b3f5SJens Axboe void bio_uninit(struct bio *bio) 204f9c78b2bSJens Axboe { 205db9819c7SChristoph Hellwig #ifdef CONFIG_BLK_CGROUP 206db9819c7SChristoph Hellwig if (bio->bi_blkg) { 207db9819c7SChristoph Hellwig blkg_put(bio->bi_blkg); 208db9819c7SChristoph Hellwig bio->bi_blkg = NULL; 209db9819c7SChristoph Hellwig } 210db9819c7SChristoph Hellwig #endif 211ece841abSJustin Tee if (bio_integrity(bio)) 212ece841abSJustin Tee bio_integrity_free(bio); 213a892c8d5SSatya Tangirala 214a892c8d5SSatya Tangirala bio_crypt_free_ctx(bio); 215f9c78b2bSJens Axboe } 2169ae3b3f5SJens Axboe EXPORT_SYMBOL(bio_uninit); 217f9c78b2bSJens Axboe 218f9c78b2bSJens Axboe static void bio_free(struct bio *bio) 219f9c78b2bSJens Axboe { 220f9c78b2bSJens Axboe struct bio_set *bs = bio->bi_pool; 221f9c78b2bSJens Axboe void *p; 222f9c78b2bSJens Axboe 2239ae3b3f5SJens Axboe bio_uninit(bio); 224f9c78b2bSJens Axboe 225f9c78b2bSJens Axboe if (bs) { 2267a800a20SChristoph Hellwig bvec_free(&bs->bvec_pool, bio->bi_io_vec, bio->bi_max_vecs); 227f9c78b2bSJens Axboe 228f9c78b2bSJens Axboe /* 229f9c78b2bSJens Axboe * If we have front padding, adjust the bio pointer before freeing 230f9c78b2bSJens Axboe */ 231f9c78b2bSJens Axboe p = bio; 232f9c78b2bSJens Axboe p -= bs->front_pad; 233f9c78b2bSJens Axboe 2348aa6ba2fSKent Overstreet mempool_free(p, &bs->bio_pool); 235f9c78b2bSJens Axboe } else { 236f9c78b2bSJens Axboe /* Bio was allocated by bio_kmalloc() */ 237f9c78b2bSJens Axboe kfree(bio); 238f9c78b2bSJens Axboe } 239f9c78b2bSJens Axboe } 240f9c78b2bSJens Axboe 2419ae3b3f5SJens Axboe /* 2429ae3b3f5SJens Axboe * Users of this function have their own bio allocation. Subsequently, 2439ae3b3f5SJens Axboe * they must remember to pair any call to bio_init() with bio_uninit() 2449ae3b3f5SJens Axboe * when IO has completed, or when the bio is released. 2459ae3b3f5SJens Axboe */ 2463a83f467SMing Lei void bio_init(struct bio *bio, struct bio_vec *table, 2473a83f467SMing Lei unsigned short max_vecs) 248f9c78b2bSJens Axboe { 249f9c78b2bSJens Axboe memset(bio, 0, sizeof(*bio)); 250c4cf5261SJens Axboe atomic_set(&bio->__bi_remaining, 1); 251dac56212SJens Axboe atomic_set(&bio->__bi_cnt, 1); 2523a83f467SMing Lei 2533a83f467SMing Lei bio->bi_io_vec = table; 2543a83f467SMing Lei bio->bi_max_vecs = max_vecs; 255f9c78b2bSJens Axboe } 256f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_init); 257f9c78b2bSJens Axboe 258f9c78b2bSJens Axboe /** 259f9c78b2bSJens Axboe * bio_reset - reinitialize a bio 260f9c78b2bSJens Axboe * @bio: bio to reset 261f9c78b2bSJens Axboe * 262f9c78b2bSJens Axboe * Description: 263f9c78b2bSJens Axboe * After calling bio_reset(), @bio will be in the same state as a freshly 264f9c78b2bSJens Axboe * allocated bio returned bio bio_alloc_bioset() - the only fields that are 265f9c78b2bSJens Axboe * preserved are the ones that are initialized by bio_alloc_bioset(). See 266f9c78b2bSJens Axboe * comment in struct bio. 267f9c78b2bSJens Axboe */ 268f9c78b2bSJens Axboe void bio_reset(struct bio *bio) 269f9c78b2bSJens Axboe { 2709ae3b3f5SJens Axboe bio_uninit(bio); 271f9c78b2bSJens Axboe memset(bio, 0, BIO_RESET_BYTES); 272c4cf5261SJens Axboe atomic_set(&bio->__bi_remaining, 1); 273f9c78b2bSJens Axboe } 274f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_reset); 275f9c78b2bSJens Axboe 27638f8baaeSChristoph Hellwig static struct bio *__bio_chain_endio(struct bio *bio) 277f9c78b2bSJens Axboe { 2784246a0b6SChristoph Hellwig struct bio *parent = bio->bi_private; 2794246a0b6SChristoph Hellwig 2803edf5346SYufen Yu if (bio->bi_status && !parent->bi_status) 2814e4cbee9SChristoph Hellwig parent->bi_status = bio->bi_status; 282f9c78b2bSJens Axboe bio_put(bio); 28338f8baaeSChristoph Hellwig return parent; 28438f8baaeSChristoph Hellwig } 28538f8baaeSChristoph Hellwig 28638f8baaeSChristoph Hellwig static void bio_chain_endio(struct bio *bio) 28738f8baaeSChristoph Hellwig { 28838f8baaeSChristoph Hellwig bio_endio(__bio_chain_endio(bio)); 289f9c78b2bSJens Axboe } 290f9c78b2bSJens Axboe 291f9c78b2bSJens Axboe /** 292f9c78b2bSJens Axboe * bio_chain - chain bio completions 293f9c78b2bSJens Axboe * @bio: the target bio 2945b874af6SMauro Carvalho Chehab * @parent: the parent bio of @bio 295f9c78b2bSJens Axboe * 296f9c78b2bSJens Axboe * The caller won't have a bi_end_io called when @bio completes - instead, 297f9c78b2bSJens Axboe * @parent's bi_end_io won't be called until both @parent and @bio have 298f9c78b2bSJens Axboe * completed; the chained bio will also be freed when it completes. 299f9c78b2bSJens Axboe * 300f9c78b2bSJens Axboe * The caller must not set bi_private or bi_end_io in @bio. 301f9c78b2bSJens Axboe */ 302f9c78b2bSJens Axboe void bio_chain(struct bio *bio, struct bio *parent) 303f9c78b2bSJens Axboe { 304f9c78b2bSJens Axboe BUG_ON(bio->bi_private || bio->bi_end_io); 305f9c78b2bSJens Axboe 306f9c78b2bSJens Axboe bio->bi_private = parent; 307f9c78b2bSJens Axboe bio->bi_end_io = bio_chain_endio; 308c4cf5261SJens Axboe bio_inc_remaining(parent); 309f9c78b2bSJens Axboe } 310f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_chain); 311f9c78b2bSJens Axboe 312f9c78b2bSJens Axboe static void bio_alloc_rescue(struct work_struct *work) 313f9c78b2bSJens Axboe { 314f9c78b2bSJens Axboe struct bio_set *bs = container_of(work, struct bio_set, rescue_work); 315f9c78b2bSJens Axboe struct bio *bio; 316f9c78b2bSJens Axboe 317f9c78b2bSJens Axboe while (1) { 318f9c78b2bSJens Axboe spin_lock(&bs->rescue_lock); 319f9c78b2bSJens Axboe bio = bio_list_pop(&bs->rescue_list); 320f9c78b2bSJens Axboe spin_unlock(&bs->rescue_lock); 321f9c78b2bSJens Axboe 322f9c78b2bSJens Axboe if (!bio) 323f9c78b2bSJens Axboe break; 324f9c78b2bSJens Axboe 325ed00aabdSChristoph Hellwig submit_bio_noacct(bio); 326f9c78b2bSJens Axboe } 327f9c78b2bSJens Axboe } 328f9c78b2bSJens Axboe 329f9c78b2bSJens Axboe static void punt_bios_to_rescuer(struct bio_set *bs) 330f9c78b2bSJens Axboe { 331f9c78b2bSJens Axboe struct bio_list punt, nopunt; 332f9c78b2bSJens Axboe struct bio *bio; 333f9c78b2bSJens Axboe 33447e0fb46SNeilBrown if (WARN_ON_ONCE(!bs->rescue_workqueue)) 33547e0fb46SNeilBrown return; 336f9c78b2bSJens Axboe /* 337f9c78b2bSJens Axboe * In order to guarantee forward progress we must punt only bios that 338f9c78b2bSJens Axboe * were allocated from this bio_set; otherwise, if there was a bio on 339f9c78b2bSJens Axboe * there for a stacking driver higher up in the stack, processing it 340f9c78b2bSJens Axboe * could require allocating bios from this bio_set, and doing that from 341f9c78b2bSJens Axboe * our own rescuer would be bad. 342f9c78b2bSJens Axboe * 343f9c78b2bSJens Axboe * Since bio lists are singly linked, pop them all instead of trying to 344f9c78b2bSJens Axboe * remove from the middle of the list: 345f9c78b2bSJens Axboe */ 346f9c78b2bSJens Axboe 347f9c78b2bSJens Axboe bio_list_init(&punt); 348f9c78b2bSJens Axboe bio_list_init(&nopunt); 349f9c78b2bSJens Axboe 350f5fe1b51SNeilBrown while ((bio = bio_list_pop(¤t->bio_list[0]))) 351f9c78b2bSJens Axboe bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio); 352f5fe1b51SNeilBrown current->bio_list[0] = nopunt; 353f9c78b2bSJens Axboe 354f5fe1b51SNeilBrown bio_list_init(&nopunt); 355f5fe1b51SNeilBrown while ((bio = bio_list_pop(¤t->bio_list[1]))) 356f5fe1b51SNeilBrown bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio); 357f5fe1b51SNeilBrown current->bio_list[1] = nopunt; 358f9c78b2bSJens Axboe 359f9c78b2bSJens Axboe spin_lock(&bs->rescue_lock); 360f9c78b2bSJens Axboe bio_list_merge(&bs->rescue_list, &punt); 361f9c78b2bSJens Axboe spin_unlock(&bs->rescue_lock); 362f9c78b2bSJens Axboe 363f9c78b2bSJens Axboe queue_work(bs->rescue_workqueue, &bs->rescue_work); 364f9c78b2bSJens Axboe } 365f9c78b2bSJens Axboe 366f9c78b2bSJens Axboe /** 367f9c78b2bSJens Axboe * bio_alloc_bioset - allocate a bio for I/O 368519c8e9fSRandy Dunlap * @gfp_mask: the GFP_* mask given to the slab allocator 369f9c78b2bSJens Axboe * @nr_iovecs: number of iovecs to pre-allocate 370f9c78b2bSJens Axboe * @bs: the bio_set to allocate from. 371f9c78b2bSJens Axboe * 3723175199aSChristoph Hellwig * Allocate a bio from the mempools in @bs. 373f9c78b2bSJens Axboe * 3743175199aSChristoph Hellwig * If %__GFP_DIRECT_RECLAIM is set then bio_alloc will always be able to 3753175199aSChristoph Hellwig * allocate a bio. This is due to the mempool guarantees. To make this work, 3763175199aSChristoph Hellwig * callers must never allocate more than 1 bio at a time from the general pool. 3773175199aSChristoph Hellwig * Callers that need to allocate more than 1 bio must always submit the 3783175199aSChristoph Hellwig * previously allocated bio for IO before attempting to allocate a new one. 3793175199aSChristoph Hellwig * Failure to do so can cause deadlocks under memory pressure. 380f9c78b2bSJens Axboe * 3813175199aSChristoph Hellwig * Note that when running under submit_bio_noacct() (i.e. any block driver), 3823175199aSChristoph Hellwig * bios are not submitted until after you return - see the code in 383ed00aabdSChristoph Hellwig * submit_bio_noacct() that converts recursion into iteration, to prevent 384f9c78b2bSJens Axboe * stack overflows. 385f9c78b2bSJens Axboe * 3863175199aSChristoph Hellwig * This would normally mean allocating multiple bios under submit_bio_noacct() 3873175199aSChristoph Hellwig * would be susceptible to deadlocks, but we have 388f9c78b2bSJens Axboe * deadlock avoidance code that resubmits any blocked bios from a rescuer 389f9c78b2bSJens Axboe * thread. 390f9c78b2bSJens Axboe * 391f9c78b2bSJens Axboe * However, we do not guarantee forward progress for allocations from other 392f9c78b2bSJens Axboe * mempools. Doing multiple allocations from the same mempool under 393ed00aabdSChristoph Hellwig * submit_bio_noacct() should be avoided - instead, use bio_set's front_pad 394f9c78b2bSJens Axboe * for per bio allocations. 395f9c78b2bSJens Axboe * 3963175199aSChristoph Hellwig * Returns: Pointer to new bio on success, NULL on failure. 397f9c78b2bSJens Axboe */ 3980f2e6ab8SChristoph Hellwig struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned short nr_iovecs, 3997a88fa19SDan Carpenter struct bio_set *bs) 400f9c78b2bSJens Axboe { 401f9c78b2bSJens Axboe gfp_t saved_gfp = gfp_mask; 402f9c78b2bSJens Axboe struct bio *bio; 403f9c78b2bSJens Axboe void *p; 404f9c78b2bSJens Axboe 4053175199aSChristoph Hellwig /* should not use nobvec bioset for nr_iovecs > 0 */ 4063175199aSChristoph Hellwig if (WARN_ON_ONCE(!mempool_initialized(&bs->bvec_pool) && nr_iovecs > 0)) 407f9c78b2bSJens Axboe return NULL; 408f9c78b2bSJens Axboe 409f9c78b2bSJens Axboe /* 4103175199aSChristoph Hellwig * submit_bio_noacct() converts recursion to iteration; this means if 4113175199aSChristoph Hellwig * we're running beneath it, any bios we allocate and submit will not be 4123175199aSChristoph Hellwig * submitted (and thus freed) until after we return. 413f9c78b2bSJens Axboe * 4143175199aSChristoph Hellwig * This exposes us to a potential deadlock if we allocate multiple bios 4153175199aSChristoph Hellwig * from the same bio_set() while running underneath submit_bio_noacct(). 4163175199aSChristoph Hellwig * If we were to allocate multiple bios (say a stacking block driver 4173175199aSChristoph Hellwig * that was splitting bios), we would deadlock if we exhausted the 4183175199aSChristoph Hellwig * mempool's reserve. 419f9c78b2bSJens Axboe * 420f9c78b2bSJens Axboe * We solve this, and guarantee forward progress, with a rescuer 4213175199aSChristoph Hellwig * workqueue per bio_set. If we go to allocate and there are bios on 4223175199aSChristoph Hellwig * current->bio_list, we first try the allocation without 4233175199aSChristoph Hellwig * __GFP_DIRECT_RECLAIM; if that fails, we punt those bios we would be 4243175199aSChristoph Hellwig * blocking to the rescuer workqueue before we retry with the original 4253175199aSChristoph Hellwig * gfp_flags. 426f9c78b2bSJens Axboe */ 427f5fe1b51SNeilBrown if (current->bio_list && 428f5fe1b51SNeilBrown (!bio_list_empty(¤t->bio_list[0]) || 42947e0fb46SNeilBrown !bio_list_empty(¤t->bio_list[1])) && 43047e0fb46SNeilBrown bs->rescue_workqueue) 431d0164adcSMel Gorman gfp_mask &= ~__GFP_DIRECT_RECLAIM; 432f9c78b2bSJens Axboe 4338aa6ba2fSKent Overstreet p = mempool_alloc(&bs->bio_pool, gfp_mask); 434f9c78b2bSJens Axboe if (!p && gfp_mask != saved_gfp) { 435f9c78b2bSJens Axboe punt_bios_to_rescuer(bs); 436f9c78b2bSJens Axboe gfp_mask = saved_gfp; 4378aa6ba2fSKent Overstreet p = mempool_alloc(&bs->bio_pool, gfp_mask); 438f9c78b2bSJens Axboe } 439f9c78b2bSJens Axboe if (unlikely(!p)) 440f9c78b2bSJens Axboe return NULL; 441f9c78b2bSJens Axboe 4423175199aSChristoph Hellwig bio = p + bs->front_pad; 4433175199aSChristoph Hellwig if (nr_iovecs > BIO_INLINE_VECS) { 4443175199aSChristoph Hellwig struct bio_vec *bvl = NULL; 445f9c78b2bSJens Axboe 4467a800a20SChristoph Hellwig bvl = bvec_alloc(&bs->bvec_pool, &nr_iovecs, gfp_mask); 447f9c78b2bSJens Axboe if (!bvl && gfp_mask != saved_gfp) { 448f9c78b2bSJens Axboe punt_bios_to_rescuer(bs); 449f9c78b2bSJens Axboe gfp_mask = saved_gfp; 4507a800a20SChristoph Hellwig bvl = bvec_alloc(&bs->bvec_pool, &nr_iovecs, gfp_mask); 451f9c78b2bSJens Axboe } 452f9c78b2bSJens Axboe if (unlikely(!bvl)) 453f9c78b2bSJens Axboe goto err_free; 454f9c78b2bSJens Axboe 4557a800a20SChristoph Hellwig bio_init(bio, bvl, nr_iovecs); 456f9c78b2bSJens Axboe } else if (nr_iovecs) { 4573175199aSChristoph Hellwig bio_init(bio, bio->bi_inline_vecs, BIO_INLINE_VECS); 4583175199aSChristoph Hellwig } else { 4593175199aSChristoph Hellwig bio_init(bio, NULL, 0); 460f9c78b2bSJens Axboe } 461f9c78b2bSJens Axboe 462f9c78b2bSJens Axboe bio->bi_pool = bs; 463f9c78b2bSJens Axboe return bio; 464f9c78b2bSJens Axboe 465f9c78b2bSJens Axboe err_free: 4668aa6ba2fSKent Overstreet mempool_free(p, &bs->bio_pool); 467f9c78b2bSJens Axboe return NULL; 468f9c78b2bSJens Axboe } 469f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_alloc_bioset); 470f9c78b2bSJens Axboe 4713175199aSChristoph Hellwig /** 4723175199aSChristoph Hellwig * bio_kmalloc - kmalloc a bio for I/O 4733175199aSChristoph Hellwig * @gfp_mask: the GFP_* mask given to the slab allocator 4743175199aSChristoph Hellwig * @nr_iovecs: number of iovecs to pre-allocate 4753175199aSChristoph Hellwig * 4763175199aSChristoph Hellwig * Use kmalloc to allocate and initialize a bio. 4773175199aSChristoph Hellwig * 4783175199aSChristoph Hellwig * Returns: Pointer to new bio on success, NULL on failure. 4793175199aSChristoph Hellwig */ 4800f2e6ab8SChristoph Hellwig struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned short nr_iovecs) 4813175199aSChristoph Hellwig { 4823175199aSChristoph Hellwig struct bio *bio; 4833175199aSChristoph Hellwig 4843175199aSChristoph Hellwig if (nr_iovecs > UIO_MAXIOV) 4853175199aSChristoph Hellwig return NULL; 4863175199aSChristoph Hellwig 4873175199aSChristoph Hellwig bio = kmalloc(struct_size(bio, bi_inline_vecs, nr_iovecs), gfp_mask); 4883175199aSChristoph Hellwig if (unlikely(!bio)) 4893175199aSChristoph Hellwig return NULL; 4903175199aSChristoph Hellwig bio_init(bio, nr_iovecs ? bio->bi_inline_vecs : NULL, nr_iovecs); 4913175199aSChristoph Hellwig bio->bi_pool = NULL; 4923175199aSChristoph Hellwig return bio; 4933175199aSChristoph Hellwig } 4943175199aSChristoph Hellwig EXPORT_SYMBOL(bio_kmalloc); 4953175199aSChristoph Hellwig 4966f822e1bSChristoph Hellwig void zero_fill_bio(struct bio *bio) 497f9c78b2bSJens Axboe { 498f9c78b2bSJens Axboe struct bio_vec bv; 499f9c78b2bSJens Axboe struct bvec_iter iter; 500f9c78b2bSJens Axboe 501*ab6c340eSChristoph Hellwig bio_for_each_segment(bv, bio, iter) 502*ab6c340eSChristoph Hellwig memzero_bvec(&bv); 503f9c78b2bSJens Axboe } 5046f822e1bSChristoph Hellwig EXPORT_SYMBOL(zero_fill_bio); 505f9c78b2bSJens Axboe 50683c9c547SMing Lei /** 50783c9c547SMing Lei * bio_truncate - truncate the bio to small size of @new_size 50883c9c547SMing Lei * @bio: the bio to be truncated 50983c9c547SMing Lei * @new_size: new size for truncating the bio 51083c9c547SMing Lei * 51183c9c547SMing Lei * Description: 51283c9c547SMing Lei * Truncate the bio to new size of @new_size. If bio_op(bio) is 51383c9c547SMing Lei * REQ_OP_READ, zero the truncated part. This function should only 51483c9c547SMing Lei * be used for handling corner cases, such as bio eod. 51583c9c547SMing Lei */ 51685a8ce62SMing Lei void bio_truncate(struct bio *bio, unsigned new_size) 51785a8ce62SMing Lei { 51885a8ce62SMing Lei struct bio_vec bv; 51985a8ce62SMing Lei struct bvec_iter iter; 52085a8ce62SMing Lei unsigned int done = 0; 52185a8ce62SMing Lei bool truncated = false; 52285a8ce62SMing Lei 52385a8ce62SMing Lei if (new_size >= bio->bi_iter.bi_size) 52485a8ce62SMing Lei return; 52585a8ce62SMing Lei 52683c9c547SMing Lei if (bio_op(bio) != REQ_OP_READ) 52785a8ce62SMing Lei goto exit; 52885a8ce62SMing Lei 52985a8ce62SMing Lei bio_for_each_segment(bv, bio, iter) { 53085a8ce62SMing Lei if (done + bv.bv_len > new_size) { 53185a8ce62SMing Lei unsigned offset; 53285a8ce62SMing Lei 53385a8ce62SMing Lei if (!truncated) 53485a8ce62SMing Lei offset = new_size - done; 53585a8ce62SMing Lei else 53685a8ce62SMing Lei offset = 0; 53785a8ce62SMing Lei zero_user(bv.bv_page, offset, bv.bv_len - offset); 53885a8ce62SMing Lei truncated = true; 53985a8ce62SMing Lei } 54085a8ce62SMing Lei done += bv.bv_len; 54185a8ce62SMing Lei } 54285a8ce62SMing Lei 54385a8ce62SMing Lei exit: 54485a8ce62SMing Lei /* 54585a8ce62SMing Lei * Don't touch bvec table here and make it really immutable, since 54685a8ce62SMing Lei * fs bio user has to retrieve all pages via bio_for_each_segment_all 54785a8ce62SMing Lei * in its .end_bio() callback. 54885a8ce62SMing Lei * 54985a8ce62SMing Lei * It is enough to truncate bio by updating .bi_size since we can make 55085a8ce62SMing Lei * correct bvec with the updated .bi_size for drivers. 55185a8ce62SMing Lei */ 55285a8ce62SMing Lei bio->bi_iter.bi_size = new_size; 55385a8ce62SMing Lei } 55485a8ce62SMing Lei 555f9c78b2bSJens Axboe /** 55629125ed6SChristoph Hellwig * guard_bio_eod - truncate a BIO to fit the block device 55729125ed6SChristoph Hellwig * @bio: bio to truncate 55829125ed6SChristoph Hellwig * 55929125ed6SChristoph Hellwig * This allows us to do IO even on the odd last sectors of a device, even if the 56029125ed6SChristoph Hellwig * block size is some multiple of the physical sector size. 56129125ed6SChristoph Hellwig * 56229125ed6SChristoph Hellwig * We'll just truncate the bio to the size of the device, and clear the end of 56329125ed6SChristoph Hellwig * the buffer head manually. Truly out-of-range accesses will turn into actual 56429125ed6SChristoph Hellwig * I/O errors, this only handles the "we need to be able to do I/O at the final 56529125ed6SChristoph Hellwig * sector" case. 56629125ed6SChristoph Hellwig */ 56729125ed6SChristoph Hellwig void guard_bio_eod(struct bio *bio) 56829125ed6SChristoph Hellwig { 569309dca30SChristoph Hellwig sector_t maxsector = bdev_nr_sectors(bio->bi_bdev); 57029125ed6SChristoph Hellwig 57129125ed6SChristoph Hellwig if (!maxsector) 57229125ed6SChristoph Hellwig return; 57329125ed6SChristoph Hellwig 57429125ed6SChristoph Hellwig /* 57529125ed6SChristoph Hellwig * If the *whole* IO is past the end of the device, 57629125ed6SChristoph Hellwig * let it through, and the IO layer will turn it into 57729125ed6SChristoph Hellwig * an EIO. 57829125ed6SChristoph Hellwig */ 57929125ed6SChristoph Hellwig if (unlikely(bio->bi_iter.bi_sector >= maxsector)) 58029125ed6SChristoph Hellwig return; 58129125ed6SChristoph Hellwig 58229125ed6SChristoph Hellwig maxsector -= bio->bi_iter.bi_sector; 58329125ed6SChristoph Hellwig if (likely((bio->bi_iter.bi_size >> 9) <= maxsector)) 58429125ed6SChristoph Hellwig return; 58529125ed6SChristoph Hellwig 58629125ed6SChristoph Hellwig bio_truncate(bio, maxsector << 9); 58729125ed6SChristoph Hellwig } 58829125ed6SChristoph Hellwig 58929125ed6SChristoph Hellwig /** 590f9c78b2bSJens Axboe * bio_put - release a reference to a bio 591f9c78b2bSJens Axboe * @bio: bio to release reference to 592f9c78b2bSJens Axboe * 593f9c78b2bSJens Axboe * Description: 594f9c78b2bSJens Axboe * Put a reference to a &struct bio, either one you have gotten with 5959b10f6a9SNeilBrown * bio_alloc, bio_get or bio_clone_*. The last put of a bio will free it. 596f9c78b2bSJens Axboe **/ 597f9c78b2bSJens Axboe void bio_put(struct bio *bio) 598f9c78b2bSJens Axboe { 599dac56212SJens Axboe if (!bio_flagged(bio, BIO_REFFED)) 600dac56212SJens Axboe bio_free(bio); 601dac56212SJens Axboe else { 602dac56212SJens Axboe BIO_BUG_ON(!atomic_read(&bio->__bi_cnt)); 603f9c78b2bSJens Axboe 604f9c78b2bSJens Axboe /* 605f9c78b2bSJens Axboe * last put frees it 606f9c78b2bSJens Axboe */ 607dac56212SJens Axboe if (atomic_dec_and_test(&bio->__bi_cnt)) 608f9c78b2bSJens Axboe bio_free(bio); 609f9c78b2bSJens Axboe } 610dac56212SJens Axboe } 611f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_put); 612f9c78b2bSJens Axboe 613f9c78b2bSJens Axboe /** 614f9c78b2bSJens Axboe * __bio_clone_fast - clone a bio that shares the original bio's biovec 615f9c78b2bSJens Axboe * @bio: destination bio 616f9c78b2bSJens Axboe * @bio_src: bio to clone 617f9c78b2bSJens Axboe * 618f9c78b2bSJens Axboe * Clone a &bio. Caller will own the returned bio, but not 619f9c78b2bSJens Axboe * the actual data it points to. Reference count of returned 620f9c78b2bSJens Axboe * bio will be one. 621f9c78b2bSJens Axboe * 622f9c78b2bSJens Axboe * Caller must ensure that @bio_src is not freed before @bio. 623f9c78b2bSJens Axboe */ 624f9c78b2bSJens Axboe void __bio_clone_fast(struct bio *bio, struct bio *bio_src) 625f9c78b2bSJens Axboe { 6267a800a20SChristoph Hellwig WARN_ON_ONCE(bio->bi_pool && bio->bi_max_vecs); 627f9c78b2bSJens Axboe 628f9c78b2bSJens Axboe /* 629309dca30SChristoph Hellwig * most users will be overriding ->bi_bdev with a new target, 630f9c78b2bSJens Axboe * so we don't set nor calculate new physical/hw segment counts here 631f9c78b2bSJens Axboe */ 632309dca30SChristoph Hellwig bio->bi_bdev = bio_src->bi_bdev; 633b7c44ed9SJens Axboe bio_set_flag(bio, BIO_CLONED); 634111be883SShaohua Li if (bio_flagged(bio_src, BIO_THROTTLED)) 635111be883SShaohua Li bio_set_flag(bio, BIO_THROTTLED); 63646bbf653SChristoph Hellwig if (bio_flagged(bio_src, BIO_REMAPPED)) 63746bbf653SChristoph Hellwig bio_set_flag(bio, BIO_REMAPPED); 6381eff9d32SJens Axboe bio->bi_opf = bio_src->bi_opf; 639ca474b73SHannes Reinecke bio->bi_ioprio = bio_src->bi_ioprio; 640cb6934f8SJens Axboe bio->bi_write_hint = bio_src->bi_write_hint; 641f9c78b2bSJens Axboe bio->bi_iter = bio_src->bi_iter; 642f9c78b2bSJens Axboe bio->bi_io_vec = bio_src->bi_io_vec; 64320bd723eSPaolo Valente 644db6638d7SDennis Zhou bio_clone_blkg_association(bio, bio_src); 645e439bedfSDennis Zhou blkcg_bio_issue_init(bio); 646f9c78b2bSJens Axboe } 647f9c78b2bSJens Axboe EXPORT_SYMBOL(__bio_clone_fast); 648f9c78b2bSJens Axboe 649f9c78b2bSJens Axboe /** 650f9c78b2bSJens Axboe * bio_clone_fast - clone a bio that shares the original bio's biovec 651f9c78b2bSJens Axboe * @bio: bio to clone 652f9c78b2bSJens Axboe * @gfp_mask: allocation priority 653f9c78b2bSJens Axboe * @bs: bio_set to allocate from 654f9c78b2bSJens Axboe * 655f9c78b2bSJens Axboe * Like __bio_clone_fast, only also allocates the returned bio 656f9c78b2bSJens Axboe */ 657f9c78b2bSJens Axboe struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) 658f9c78b2bSJens Axboe { 659f9c78b2bSJens Axboe struct bio *b; 660f9c78b2bSJens Axboe 661f9c78b2bSJens Axboe b = bio_alloc_bioset(gfp_mask, 0, bs); 662f9c78b2bSJens Axboe if (!b) 663f9c78b2bSJens Axboe return NULL; 664f9c78b2bSJens Axboe 665f9c78b2bSJens Axboe __bio_clone_fast(b, bio); 666f9c78b2bSJens Axboe 66707560151SEric Biggers if (bio_crypt_clone(b, bio, gfp_mask) < 0) 66807560151SEric Biggers goto err_put; 669a892c8d5SSatya Tangirala 67007560151SEric Biggers if (bio_integrity(bio) && 67107560151SEric Biggers bio_integrity_clone(b, bio, gfp_mask) < 0) 67207560151SEric Biggers goto err_put; 673f9c78b2bSJens Axboe 674f9c78b2bSJens Axboe return b; 67507560151SEric Biggers 67607560151SEric Biggers err_put: 67707560151SEric Biggers bio_put(b); 67807560151SEric Biggers return NULL; 679f9c78b2bSJens Axboe } 680f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_clone_fast); 681f9c78b2bSJens Axboe 6825cbd28e3SChristoph Hellwig const char *bio_devname(struct bio *bio, char *buf) 6835cbd28e3SChristoph Hellwig { 684309dca30SChristoph Hellwig return bdevname(bio->bi_bdev, buf); 6855cbd28e3SChristoph Hellwig } 6865cbd28e3SChristoph Hellwig EXPORT_SYMBOL(bio_devname); 6875cbd28e3SChristoph Hellwig 6885919482eSMing Lei static inline bool page_is_mergeable(const struct bio_vec *bv, 6895919482eSMing Lei struct page *page, unsigned int len, unsigned int off, 690ff896738SChristoph Hellwig bool *same_page) 6915919482eSMing Lei { 692d8166519SMatthew Wilcox (Oracle) size_t bv_end = bv->bv_offset + bv->bv_len; 693d8166519SMatthew Wilcox (Oracle) phys_addr_t vec_end_addr = page_to_phys(bv->bv_page) + bv_end - 1; 6945919482eSMing Lei phys_addr_t page_addr = page_to_phys(page); 6955919482eSMing Lei 6965919482eSMing Lei if (vec_end_addr + 1 != page_addr + off) 6975919482eSMing Lei return false; 6985919482eSMing Lei if (xen_domain() && !xen_biovec_phys_mergeable(bv, page)) 6995919482eSMing Lei return false; 70052d52d1cSChristoph Hellwig 701ff896738SChristoph Hellwig *same_page = ((vec_end_addr & PAGE_MASK) == page_addr); 702d8166519SMatthew Wilcox (Oracle) if (*same_page) 7035919482eSMing Lei return true; 704d8166519SMatthew Wilcox (Oracle) return (bv->bv_page + bv_end / PAGE_SIZE) == (page + off / PAGE_SIZE); 7055919482eSMing Lei } 7065919482eSMing Lei 707e4581105SChristoph Hellwig /* 708e4581105SChristoph Hellwig * Try to merge a page into a segment, while obeying the hardware segment 709e4581105SChristoph Hellwig * size limit. This is not for normal read/write bios, but for passthrough 710e4581105SChristoph Hellwig * or Zone Append operations that we can't split. 711e4581105SChristoph Hellwig */ 712e4581105SChristoph Hellwig static bool bio_try_merge_hw_seg(struct request_queue *q, struct bio *bio, 713e4581105SChristoph Hellwig struct page *page, unsigned len, 714e4581105SChristoph Hellwig unsigned offset, bool *same_page) 715489fbbcbSMing Lei { 716384209cdSChristoph Hellwig struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1]; 717489fbbcbSMing Lei unsigned long mask = queue_segment_boundary(q); 718489fbbcbSMing Lei phys_addr_t addr1 = page_to_phys(bv->bv_page) + bv->bv_offset; 719489fbbcbSMing Lei phys_addr_t addr2 = page_to_phys(page) + offset + len - 1; 720489fbbcbSMing Lei 721489fbbcbSMing Lei if ((addr1 | mask) != (addr2 | mask)) 722489fbbcbSMing Lei return false; 723489fbbcbSMing Lei if (bv->bv_len + len > queue_max_segment_size(q)) 724489fbbcbSMing Lei return false; 725384209cdSChristoph Hellwig return __bio_try_merge_page(bio, page, len, offset, same_page); 726489fbbcbSMing Lei } 727489fbbcbSMing Lei 728f4595875SShaohua Li /** 729e4581105SChristoph Hellwig * bio_add_hw_page - attempt to add a page to a bio with hw constraints 730c66a14d0SKent Overstreet * @q: the target queue 731c66a14d0SKent Overstreet * @bio: destination bio 732c66a14d0SKent Overstreet * @page: page to add 733c66a14d0SKent Overstreet * @len: vec entry length 734c66a14d0SKent Overstreet * @offset: vec entry offset 735e4581105SChristoph Hellwig * @max_sectors: maximum number of sectors that can be added 736e4581105SChristoph Hellwig * @same_page: return if the segment has been merged inside the same page 737f9c78b2bSJens Axboe * 738e4581105SChristoph Hellwig * Add a page to a bio while respecting the hardware max_sectors, max_segment 739e4581105SChristoph Hellwig * and gap limitations. 740f9c78b2bSJens Axboe */ 741e4581105SChristoph Hellwig int bio_add_hw_page(struct request_queue *q, struct bio *bio, 74219047087SMing Lei struct page *page, unsigned int len, unsigned int offset, 743e4581105SChristoph Hellwig unsigned int max_sectors, bool *same_page) 744f9c78b2bSJens Axboe { 745f9c78b2bSJens Axboe struct bio_vec *bvec; 746f9c78b2bSJens Axboe 747e4581105SChristoph Hellwig if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED))) 748f9c78b2bSJens Axboe return 0; 749f9c78b2bSJens Axboe 750e4581105SChristoph Hellwig if (((bio->bi_iter.bi_size + len) >> 9) > max_sectors) 751f9c78b2bSJens Axboe return 0; 752f9c78b2bSJens Axboe 753f9c78b2bSJens Axboe if (bio->bi_vcnt > 0) { 754e4581105SChristoph Hellwig if (bio_try_merge_hw_seg(q, bio, page, len, offset, same_page)) 755384209cdSChristoph Hellwig return len; 756320ea869SChristoph Hellwig 757320ea869SChristoph Hellwig /* 758320ea869SChristoph Hellwig * If the queue doesn't support SG gaps and adding this segment 759320ea869SChristoph Hellwig * would create a gap, disallow it. 760320ea869SChristoph Hellwig */ 761384209cdSChristoph Hellwig bvec = &bio->bi_io_vec[bio->bi_vcnt - 1]; 762320ea869SChristoph Hellwig if (bvec_gap_to_prev(q, bvec, offset)) 763320ea869SChristoph Hellwig return 0; 764f9c78b2bSJens Axboe } 765f9c78b2bSJens Axboe 76679d08f89SMing Lei if (bio_full(bio, len)) 767f9c78b2bSJens Axboe return 0; 768f9c78b2bSJens Axboe 76914ccb66bSChristoph Hellwig if (bio->bi_vcnt >= queue_max_segments(q)) 770489fbbcbSMing Lei return 0; 771489fbbcbSMing Lei 772f9c78b2bSJens Axboe bvec = &bio->bi_io_vec[bio->bi_vcnt]; 773f9c78b2bSJens Axboe bvec->bv_page = page; 774f9c78b2bSJens Axboe bvec->bv_len = len; 775f9c78b2bSJens Axboe bvec->bv_offset = offset; 776fcbf6a08SMaurizio Lombardi bio->bi_vcnt++; 777dcdca753SChristoph Hellwig bio->bi_iter.bi_size += len; 778f9c78b2bSJens Axboe return len; 779f9c78b2bSJens Axboe } 78019047087SMing Lei 781e4581105SChristoph Hellwig /** 782e4581105SChristoph Hellwig * bio_add_pc_page - attempt to add page to passthrough bio 783e4581105SChristoph Hellwig * @q: the target queue 784e4581105SChristoph Hellwig * @bio: destination bio 785e4581105SChristoph Hellwig * @page: page to add 786e4581105SChristoph Hellwig * @len: vec entry length 787e4581105SChristoph Hellwig * @offset: vec entry offset 788e4581105SChristoph Hellwig * 789e4581105SChristoph Hellwig * Attempt to add a page to the bio_vec maplist. This can fail for a 790e4581105SChristoph Hellwig * number of reasons, such as the bio being full or target block device 791e4581105SChristoph Hellwig * limitations. The target block device must allow bio's up to PAGE_SIZE, 792e4581105SChristoph Hellwig * so it is always possible to add a single page to an empty bio. 793e4581105SChristoph Hellwig * 794e4581105SChristoph Hellwig * This should only be used by passthrough bios. 795e4581105SChristoph Hellwig */ 79619047087SMing Lei int bio_add_pc_page(struct request_queue *q, struct bio *bio, 79719047087SMing Lei struct page *page, unsigned int len, unsigned int offset) 79819047087SMing Lei { 799d1916c86SChristoph Hellwig bool same_page = false; 800e4581105SChristoph Hellwig return bio_add_hw_page(q, bio, page, len, offset, 801e4581105SChristoph Hellwig queue_max_hw_sectors(q), &same_page); 80219047087SMing Lei } 803f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_add_pc_page); 804f9c78b2bSJens Axboe 805f9c78b2bSJens Axboe /** 806ae29333fSJohannes Thumshirn * bio_add_zone_append_page - attempt to add page to zone-append bio 807ae29333fSJohannes Thumshirn * @bio: destination bio 808ae29333fSJohannes Thumshirn * @page: page to add 809ae29333fSJohannes Thumshirn * @len: vec entry length 810ae29333fSJohannes Thumshirn * @offset: vec entry offset 811ae29333fSJohannes Thumshirn * 812ae29333fSJohannes Thumshirn * Attempt to add a page to the bio_vec maplist of a bio that will be submitted 813ae29333fSJohannes Thumshirn * for a zone-append request. This can fail for a number of reasons, such as the 814ae29333fSJohannes Thumshirn * bio being full or the target block device is not a zoned block device or 815ae29333fSJohannes Thumshirn * other limitations of the target block device. The target block device must 816ae29333fSJohannes Thumshirn * allow bio's up to PAGE_SIZE, so it is always possible to add a single page 817ae29333fSJohannes Thumshirn * to an empty bio. 818ae29333fSJohannes Thumshirn * 819ae29333fSJohannes Thumshirn * Returns: number of bytes added to the bio, or 0 in case of a failure. 820ae29333fSJohannes Thumshirn */ 821ae29333fSJohannes Thumshirn int bio_add_zone_append_page(struct bio *bio, struct page *page, 822ae29333fSJohannes Thumshirn unsigned int len, unsigned int offset) 823ae29333fSJohannes Thumshirn { 824582cd91fSLinus Torvalds struct request_queue *q = bio->bi_bdev->bd_disk->queue; 825ae29333fSJohannes Thumshirn bool same_page = false; 826ae29333fSJohannes Thumshirn 827ae29333fSJohannes Thumshirn if (WARN_ON_ONCE(bio_op(bio) != REQ_OP_ZONE_APPEND)) 828ae29333fSJohannes Thumshirn return 0; 829ae29333fSJohannes Thumshirn 830ae29333fSJohannes Thumshirn if (WARN_ON_ONCE(!blk_queue_is_zoned(q))) 831ae29333fSJohannes Thumshirn return 0; 832ae29333fSJohannes Thumshirn 833ae29333fSJohannes Thumshirn return bio_add_hw_page(q, bio, page, len, offset, 834ae29333fSJohannes Thumshirn queue_max_zone_append_sectors(q), &same_page); 835ae29333fSJohannes Thumshirn } 836ae29333fSJohannes Thumshirn EXPORT_SYMBOL_GPL(bio_add_zone_append_page); 837ae29333fSJohannes Thumshirn 838ae29333fSJohannes Thumshirn /** 8390aa69fd3SChristoph Hellwig * __bio_try_merge_page - try appending data to an existing bvec. 8400aa69fd3SChristoph Hellwig * @bio: destination bio 841551879a4SMing Lei * @page: start page to add 8420aa69fd3SChristoph Hellwig * @len: length of the data to add 843551879a4SMing Lei * @off: offset of the data relative to @page 844ff896738SChristoph Hellwig * @same_page: return if the segment has been merged inside the same page 8450aa69fd3SChristoph Hellwig * 8460aa69fd3SChristoph Hellwig * Try to add the data at @page + @off to the last bvec of @bio. This is a 8473cf14889SRandy Dunlap * useful optimisation for file systems with a block size smaller than the 8480aa69fd3SChristoph Hellwig * page size. 8490aa69fd3SChristoph Hellwig * 850551879a4SMing Lei * Warn if (@len, @off) crosses pages in case that @same_page is true. 851551879a4SMing Lei * 8520aa69fd3SChristoph Hellwig * Return %true on success or %false on failure. 8530aa69fd3SChristoph Hellwig */ 8540aa69fd3SChristoph Hellwig bool __bio_try_merge_page(struct bio *bio, struct page *page, 855ff896738SChristoph Hellwig unsigned int len, unsigned int off, bool *same_page) 8560aa69fd3SChristoph Hellwig { 8570aa69fd3SChristoph Hellwig if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED))) 8580aa69fd3SChristoph Hellwig return false; 8590aa69fd3SChristoph Hellwig 860cc90bc68SAndreas Gruenbacher if (bio->bi_vcnt > 0) { 8610aa69fd3SChristoph Hellwig struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1]; 8620aa69fd3SChristoph Hellwig 8635919482eSMing Lei if (page_is_mergeable(bv, page, len, off, same_page)) { 86435c820e7SJens Axboe if (bio->bi_iter.bi_size > UINT_MAX - len) { 8652cd896a5SRitesh Harjani *same_page = false; 866cc90bc68SAndreas Gruenbacher return false; 8672cd896a5SRitesh Harjani } 8680aa69fd3SChristoph Hellwig bv->bv_len += len; 8690aa69fd3SChristoph Hellwig bio->bi_iter.bi_size += len; 8700aa69fd3SChristoph Hellwig return true; 8710aa69fd3SChristoph Hellwig } 8725919482eSMing Lei } 8730aa69fd3SChristoph Hellwig return false; 8740aa69fd3SChristoph Hellwig } 8750aa69fd3SChristoph Hellwig EXPORT_SYMBOL_GPL(__bio_try_merge_page); 8760aa69fd3SChristoph Hellwig 8770aa69fd3SChristoph Hellwig /** 878551879a4SMing Lei * __bio_add_page - add page(s) to a bio in a new segment 8790aa69fd3SChristoph Hellwig * @bio: destination bio 880551879a4SMing Lei * @page: start page to add 881551879a4SMing Lei * @len: length of the data to add, may cross pages 882551879a4SMing Lei * @off: offset of the data relative to @page, may cross pages 8830aa69fd3SChristoph Hellwig * 8840aa69fd3SChristoph Hellwig * Add the data at @page + @off to @bio as a new bvec. The caller must ensure 8850aa69fd3SChristoph Hellwig * that @bio has space for another bvec. 8860aa69fd3SChristoph Hellwig */ 8870aa69fd3SChristoph Hellwig void __bio_add_page(struct bio *bio, struct page *page, 8880aa69fd3SChristoph Hellwig unsigned int len, unsigned int off) 8890aa69fd3SChristoph Hellwig { 8900aa69fd3SChristoph Hellwig struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt]; 8910aa69fd3SChristoph Hellwig 8920aa69fd3SChristoph Hellwig WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)); 89379d08f89SMing Lei WARN_ON_ONCE(bio_full(bio, len)); 8940aa69fd3SChristoph Hellwig 8950aa69fd3SChristoph Hellwig bv->bv_page = page; 8960aa69fd3SChristoph Hellwig bv->bv_offset = off; 8970aa69fd3SChristoph Hellwig bv->bv_len = len; 8980aa69fd3SChristoph Hellwig 8990aa69fd3SChristoph Hellwig bio->bi_iter.bi_size += len; 9000aa69fd3SChristoph Hellwig bio->bi_vcnt++; 901b8e24a93SJohannes Weiner 902b8e24a93SJohannes Weiner if (!bio_flagged(bio, BIO_WORKINGSET) && unlikely(PageWorkingset(page))) 903b8e24a93SJohannes Weiner bio_set_flag(bio, BIO_WORKINGSET); 9040aa69fd3SChristoph Hellwig } 9050aa69fd3SChristoph Hellwig EXPORT_SYMBOL_GPL(__bio_add_page); 9060aa69fd3SChristoph Hellwig 9070aa69fd3SChristoph Hellwig /** 908551879a4SMing Lei * bio_add_page - attempt to add page(s) to bio 909f9c78b2bSJens Axboe * @bio: destination bio 910551879a4SMing Lei * @page: start page to add 911551879a4SMing Lei * @len: vec entry length, may cross pages 912551879a4SMing Lei * @offset: vec entry offset relative to @page, may cross pages 913f9c78b2bSJens Axboe * 914551879a4SMing Lei * Attempt to add page(s) to the bio_vec maplist. This will only fail 915c66a14d0SKent Overstreet * if either bio->bi_vcnt == bio->bi_max_vecs or it's a cloned bio. 916f9c78b2bSJens Axboe */ 917c66a14d0SKent Overstreet int bio_add_page(struct bio *bio, struct page *page, 918c66a14d0SKent Overstreet unsigned int len, unsigned int offset) 919f9c78b2bSJens Axboe { 920ff896738SChristoph Hellwig bool same_page = false; 921ff896738SChristoph Hellwig 922ff896738SChristoph Hellwig if (!__bio_try_merge_page(bio, page, len, offset, &same_page)) { 92379d08f89SMing Lei if (bio_full(bio, len)) 924c66a14d0SKent Overstreet return 0; 9250aa69fd3SChristoph Hellwig __bio_add_page(bio, page, len, offset); 926c66a14d0SKent Overstreet } 927c66a14d0SKent Overstreet return len; 928f9c78b2bSJens Axboe } 929f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_add_page); 930f9c78b2bSJens Axboe 931d241a95fSChristoph Hellwig void bio_release_pages(struct bio *bio, bool mark_dirty) 9327321ecbfSChristoph Hellwig { 9337321ecbfSChristoph Hellwig struct bvec_iter_all iter_all; 9347321ecbfSChristoph Hellwig struct bio_vec *bvec; 9357321ecbfSChristoph Hellwig 936b2d0d991SChristoph Hellwig if (bio_flagged(bio, BIO_NO_PAGE_REF)) 937b2d0d991SChristoph Hellwig return; 938b2d0d991SChristoph Hellwig 939d241a95fSChristoph Hellwig bio_for_each_segment_all(bvec, bio, iter_all) { 940d241a95fSChristoph Hellwig if (mark_dirty && !PageCompound(bvec->bv_page)) 941d241a95fSChristoph Hellwig set_page_dirty_lock(bvec->bv_page); 9427321ecbfSChristoph Hellwig put_page(bvec->bv_page); 9437321ecbfSChristoph Hellwig } 944d241a95fSChristoph Hellwig } 94529b2a3aaSJohannes Thumshirn EXPORT_SYMBOL_GPL(bio_release_pages); 9467321ecbfSChristoph Hellwig 9477de55b7dSJohannes Thumshirn static void __bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter) 9486d0c48aeSJens Axboe { 9497a800a20SChristoph Hellwig WARN_ON_ONCE(bio->bi_max_vecs); 9506d0c48aeSJens Axboe 951c42bca92SPavel Begunkov bio->bi_vcnt = iter->nr_segs; 952c42bca92SPavel Begunkov bio->bi_io_vec = (struct bio_vec *)iter->bvec; 953c42bca92SPavel Begunkov bio->bi_iter.bi_bvec_done = iter->iov_offset; 954c42bca92SPavel Begunkov bio->bi_iter.bi_size = iter->count; 955ed97ce5eSChristoph Hellwig bio_set_flag(bio, BIO_NO_PAGE_REF); 956977be012SChristoph Hellwig bio_set_flag(bio, BIO_CLONED); 9577de55b7dSJohannes Thumshirn } 9586d0c48aeSJens Axboe 9597de55b7dSJohannes Thumshirn static int bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter) 9607de55b7dSJohannes Thumshirn { 9617de55b7dSJohannes Thumshirn __bio_iov_bvec_set(bio, iter); 962c42bca92SPavel Begunkov iov_iter_advance(iter, iter->count); 9636d0c48aeSJens Axboe return 0; 9646d0c48aeSJens Axboe } 9656d0c48aeSJens Axboe 9667de55b7dSJohannes Thumshirn static int bio_iov_bvec_set_append(struct bio *bio, struct iov_iter *iter) 9677de55b7dSJohannes Thumshirn { 9687de55b7dSJohannes Thumshirn struct request_queue *q = bio->bi_bdev->bd_disk->queue; 9697de55b7dSJohannes Thumshirn struct iov_iter i = *iter; 9707de55b7dSJohannes Thumshirn 9717de55b7dSJohannes Thumshirn iov_iter_truncate(&i, queue_max_zone_append_sectors(q) << 9); 9727de55b7dSJohannes Thumshirn __bio_iov_bvec_set(bio, &i); 9737de55b7dSJohannes Thumshirn iov_iter_advance(iter, i.count); 9747de55b7dSJohannes Thumshirn return 0; 9757de55b7dSJohannes Thumshirn } 9767de55b7dSJohannes Thumshirn 977576ed913SChristoph Hellwig #define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *)) 978576ed913SChristoph Hellwig 9792cefe4dbSKent Overstreet /** 98017d51b10SMartin Wilck * __bio_iov_iter_get_pages - pin user or kernel pages and add them to a bio 9812cefe4dbSKent Overstreet * @bio: bio to add pages to 9822cefe4dbSKent Overstreet * @iter: iov iterator describing the region to be mapped 9832cefe4dbSKent Overstreet * 98417d51b10SMartin Wilck * Pins pages from *iter and appends them to @bio's bvec array. The 9852cefe4dbSKent Overstreet * pages will have to be released using put_page() when done. 98617d51b10SMartin Wilck * For multi-segment *iter, this function only adds pages from the 9873cf14889SRandy Dunlap * next non-empty segment of the iov iterator. 9882cefe4dbSKent Overstreet */ 98917d51b10SMartin Wilck static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 9902cefe4dbSKent Overstreet { 991576ed913SChristoph Hellwig unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt; 992576ed913SChristoph Hellwig unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt; 9932cefe4dbSKent Overstreet struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt; 9942cefe4dbSKent Overstreet struct page **pages = (struct page **)bv; 99545691804SChristoph Hellwig bool same_page = false; 996576ed913SChristoph Hellwig ssize_t size, left; 997576ed913SChristoph Hellwig unsigned len, i; 998b403ea24SMartin Wilck size_t offset; 999576ed913SChristoph Hellwig 1000576ed913SChristoph Hellwig /* 1001576ed913SChristoph Hellwig * Move page array up in the allocated memory for the bio vecs as far as 1002576ed913SChristoph Hellwig * possible so that we can start filling biovecs from the beginning 1003576ed913SChristoph Hellwig * without overwriting the temporary page array. 1004576ed913SChristoph Hellwig */ 1005576ed913SChristoph Hellwig BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2); 1006576ed913SChristoph Hellwig pages += entries_left * (PAGE_PTRS_PER_BVEC - 1); 10072cefe4dbSKent Overstreet 100835c820e7SJens Axboe size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset); 10092cefe4dbSKent Overstreet if (unlikely(size <= 0)) 10102cefe4dbSKent Overstreet return size ? size : -EFAULT; 10112cefe4dbSKent Overstreet 1012576ed913SChristoph Hellwig for (left = size, i = 0; left > 0; left -= len, i++) { 1013576ed913SChristoph Hellwig struct page *page = pages[i]; 10142cefe4dbSKent Overstreet 1015576ed913SChristoph Hellwig len = min_t(size_t, PAGE_SIZE - offset, left); 101645691804SChristoph Hellwig 101745691804SChristoph Hellwig if (__bio_try_merge_page(bio, page, len, offset, &same_page)) { 101845691804SChristoph Hellwig if (same_page) 101945691804SChristoph Hellwig put_page(page); 102045691804SChristoph Hellwig } else { 102179d08f89SMing Lei if (WARN_ON_ONCE(bio_full(bio, len))) 1022576ed913SChristoph Hellwig return -EINVAL; 102345691804SChristoph Hellwig __bio_add_page(bio, page, len, offset); 102445691804SChristoph Hellwig } 1025576ed913SChristoph Hellwig offset = 0; 10262cefe4dbSKent Overstreet } 10272cefe4dbSKent Overstreet 10282cefe4dbSKent Overstreet iov_iter_advance(iter, size); 10292cefe4dbSKent Overstreet return 0; 10302cefe4dbSKent Overstreet } 103117d51b10SMartin Wilck 10320512a75bSKeith Busch static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter) 10330512a75bSKeith Busch { 10340512a75bSKeith Busch unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt; 10350512a75bSKeith Busch unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt; 1036309dca30SChristoph Hellwig struct request_queue *q = bio->bi_bdev->bd_disk->queue; 10370512a75bSKeith Busch unsigned int max_append_sectors = queue_max_zone_append_sectors(q); 10380512a75bSKeith Busch struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt; 10390512a75bSKeith Busch struct page **pages = (struct page **)bv; 10400512a75bSKeith Busch ssize_t size, left; 10410512a75bSKeith Busch unsigned len, i; 10420512a75bSKeith Busch size_t offset; 10434977d121SNaohiro Aota int ret = 0; 10440512a75bSKeith Busch 10450512a75bSKeith Busch if (WARN_ON_ONCE(!max_append_sectors)) 10460512a75bSKeith Busch return 0; 10470512a75bSKeith Busch 10480512a75bSKeith Busch /* 10490512a75bSKeith Busch * Move page array up in the allocated memory for the bio vecs as far as 10500512a75bSKeith Busch * possible so that we can start filling biovecs from the beginning 10510512a75bSKeith Busch * without overwriting the temporary page array. 10520512a75bSKeith Busch */ 10530512a75bSKeith Busch BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2); 10540512a75bSKeith Busch pages += entries_left * (PAGE_PTRS_PER_BVEC - 1); 10550512a75bSKeith Busch 10560512a75bSKeith Busch size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset); 10570512a75bSKeith Busch if (unlikely(size <= 0)) 10580512a75bSKeith Busch return size ? size : -EFAULT; 10590512a75bSKeith Busch 10600512a75bSKeith Busch for (left = size, i = 0; left > 0; left -= len, i++) { 10610512a75bSKeith Busch struct page *page = pages[i]; 10620512a75bSKeith Busch bool same_page = false; 10630512a75bSKeith Busch 10640512a75bSKeith Busch len = min_t(size_t, PAGE_SIZE - offset, left); 10650512a75bSKeith Busch if (bio_add_hw_page(q, bio, page, len, offset, 10664977d121SNaohiro Aota max_append_sectors, &same_page) != len) { 10674977d121SNaohiro Aota ret = -EINVAL; 10684977d121SNaohiro Aota break; 10694977d121SNaohiro Aota } 10700512a75bSKeith Busch if (same_page) 10710512a75bSKeith Busch put_page(page); 10720512a75bSKeith Busch offset = 0; 10730512a75bSKeith Busch } 10740512a75bSKeith Busch 10754977d121SNaohiro Aota iov_iter_advance(iter, size - left); 10764977d121SNaohiro Aota return ret; 10770512a75bSKeith Busch } 10780512a75bSKeith Busch 107917d51b10SMartin Wilck /** 10806d0c48aeSJens Axboe * bio_iov_iter_get_pages - add user or kernel pages to a bio 108117d51b10SMartin Wilck * @bio: bio to add pages to 10826d0c48aeSJens Axboe * @iter: iov iterator describing the region to be added 108317d51b10SMartin Wilck * 10846d0c48aeSJens Axboe * This takes either an iterator pointing to user memory, or one pointing to 10856d0c48aeSJens Axboe * kernel pages (BVEC iterator). If we're adding user pages, we pin them and 10866d0c48aeSJens Axboe * map them into the kernel. On IO completion, the caller should put those 1087c42bca92SPavel Begunkov * pages. For bvec based iterators bio_iov_iter_get_pages() uses the provided 1088c42bca92SPavel Begunkov * bvecs rather than copying them. Hence anyone issuing kiocb based IO needs 1089c42bca92SPavel Begunkov * to ensure the bvecs and pages stay referenced until the submitted I/O is 1090c42bca92SPavel Begunkov * completed by a call to ->ki_complete() or returns with an error other than 1091c42bca92SPavel Begunkov * -EIOCBQUEUED. The caller needs to check if the bio is flagged BIO_NO_PAGE_REF 1092c42bca92SPavel Begunkov * on IO completion. If it isn't, then pages should be released. 10936d0c48aeSJens Axboe * 109417d51b10SMartin Wilck * The function tries, but does not guarantee, to pin as many pages as 10955cd3ddc1SMauro Carvalho Chehab * fit into the bio, or are requested in @iter, whatever is smaller. If 10966d0c48aeSJens Axboe * MM encounters an error pinning the requested pages, it stops. Error 10976d0c48aeSJens Axboe * is returned only if 0 pages could be pinned. 10980cf41e5eSPavel Begunkov * 10990cf41e5eSPavel Begunkov * It's intended for direct IO, so doesn't do PSI tracking, the caller is 11000cf41e5eSPavel Begunkov * responsible for setting BIO_WORKINGSET if necessary. 110117d51b10SMartin Wilck */ 110217d51b10SMartin Wilck int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 110317d51b10SMartin Wilck { 1104c42bca92SPavel Begunkov int ret = 0; 110514eacf12SChristoph Hellwig 1106c42bca92SPavel Begunkov if (iov_iter_is_bvec(iter)) { 11077de55b7dSJohannes Thumshirn if (bio_op(bio) == REQ_OP_ZONE_APPEND) 11087de55b7dSJohannes Thumshirn return bio_iov_bvec_set_append(bio, iter); 1109ed97ce5eSChristoph Hellwig return bio_iov_bvec_set(bio, iter); 111086004515SChristoph Hellwig } 111117d51b10SMartin Wilck 111217d51b10SMartin Wilck do { 1113c42bca92SPavel Begunkov if (bio_op(bio) == REQ_OP_ZONE_APPEND) 11140512a75bSKeith Busch ret = __bio_iov_append_get_pages(bio, iter); 11156d0c48aeSJens Axboe else 11166d0c48aeSJens Axboe ret = __bio_iov_iter_get_pages(bio, iter); 111779d08f89SMing Lei } while (!ret && iov_iter_count(iter) && !bio_full(bio, 0)); 111817d51b10SMartin Wilck 11190cf41e5eSPavel Begunkov /* don't account direct I/O as memory stall */ 11200cf41e5eSPavel Begunkov bio_clear_flag(bio, BIO_WORKINGSET); 112114eacf12SChristoph Hellwig return bio->bi_vcnt ? 0 : ret; 112217d51b10SMartin Wilck } 112329b2a3aaSJohannes Thumshirn EXPORT_SYMBOL_GPL(bio_iov_iter_get_pages); 11242cefe4dbSKent Overstreet 11254246a0b6SChristoph Hellwig static void submit_bio_wait_endio(struct bio *bio) 1126f9c78b2bSJens Axboe { 112765e53aabSChristoph Hellwig complete(bio->bi_private); 1128f9c78b2bSJens Axboe } 1129f9c78b2bSJens Axboe 1130f9c78b2bSJens Axboe /** 1131f9c78b2bSJens Axboe * submit_bio_wait - submit a bio, and wait until it completes 1132f9c78b2bSJens Axboe * @bio: The &struct bio which describes the I/O 1133f9c78b2bSJens Axboe * 1134f9c78b2bSJens Axboe * Simple wrapper around submit_bio(). Returns 0 on success, or the error from 1135f9c78b2bSJens Axboe * bio_endio() on failure. 11363d289d68SJan Kara * 11373d289d68SJan Kara * WARNING: Unlike to how submit_bio() is usually used, this function does not 11383d289d68SJan Kara * result in bio reference to be consumed. The caller must drop the reference 11393d289d68SJan Kara * on his own. 1140f9c78b2bSJens Axboe */ 11414e49ea4aSMike Christie int submit_bio_wait(struct bio *bio) 1142f9c78b2bSJens Axboe { 1143309dca30SChristoph Hellwig DECLARE_COMPLETION_ONSTACK_MAP(done, 1144309dca30SChristoph Hellwig bio->bi_bdev->bd_disk->lockdep_map); 1145de6a78b6SMing Lei unsigned long hang_check; 1146f9c78b2bSJens Axboe 114765e53aabSChristoph Hellwig bio->bi_private = &done; 1148f9c78b2bSJens Axboe bio->bi_end_io = submit_bio_wait_endio; 11491eff9d32SJens Axboe bio->bi_opf |= REQ_SYNC; 11504e49ea4aSMike Christie submit_bio(bio); 1151de6a78b6SMing Lei 1152de6a78b6SMing Lei /* Prevent hang_check timer from firing at us during very long I/O */ 1153de6a78b6SMing Lei hang_check = sysctl_hung_task_timeout_secs; 1154de6a78b6SMing Lei if (hang_check) 1155de6a78b6SMing Lei while (!wait_for_completion_io_timeout(&done, 1156de6a78b6SMing Lei hang_check * (HZ/2))) 1157de6a78b6SMing Lei ; 1158de6a78b6SMing Lei else 115965e53aabSChristoph Hellwig wait_for_completion_io(&done); 1160f9c78b2bSJens Axboe 116165e53aabSChristoph Hellwig return blk_status_to_errno(bio->bi_status); 1162f9c78b2bSJens Axboe } 1163f9c78b2bSJens Axboe EXPORT_SYMBOL(submit_bio_wait); 1164f9c78b2bSJens Axboe 1165f9c78b2bSJens Axboe /** 1166f9c78b2bSJens Axboe * bio_advance - increment/complete a bio by some number of bytes 1167f9c78b2bSJens Axboe * @bio: bio to advance 1168f9c78b2bSJens Axboe * @bytes: number of bytes to complete 1169f9c78b2bSJens Axboe * 1170f9c78b2bSJens Axboe * This updates bi_sector, bi_size and bi_idx; if the number of bytes to 1171f9c78b2bSJens Axboe * complete doesn't align with a bvec boundary, then bv_len and bv_offset will 1172f9c78b2bSJens Axboe * be updated on the last bvec as well. 1173f9c78b2bSJens Axboe * 1174f9c78b2bSJens Axboe * @bio will then represent the remaining, uncompleted portion of the io. 1175f9c78b2bSJens Axboe */ 1176f9c78b2bSJens Axboe void bio_advance(struct bio *bio, unsigned bytes) 1177f9c78b2bSJens Axboe { 1178f9c78b2bSJens Axboe if (bio_integrity(bio)) 1179f9c78b2bSJens Axboe bio_integrity_advance(bio, bytes); 1180f9c78b2bSJens Axboe 1181a892c8d5SSatya Tangirala bio_crypt_advance(bio, bytes); 1182f9c78b2bSJens Axboe bio_advance_iter(bio, &bio->bi_iter, bytes); 1183f9c78b2bSJens Axboe } 1184f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_advance); 1185f9c78b2bSJens Axboe 118645db54d5SKent Overstreet void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter, 118745db54d5SKent Overstreet struct bio *src, struct bvec_iter *src_iter) 1188f9c78b2bSJens Axboe { 1189f9c78b2bSJens Axboe struct bio_vec src_bv, dst_bv; 1190f9c78b2bSJens Axboe void *src_p, *dst_p; 1191f9c78b2bSJens Axboe unsigned bytes; 1192f9c78b2bSJens Axboe 119345db54d5SKent Overstreet while (src_iter->bi_size && dst_iter->bi_size) { 119445db54d5SKent Overstreet src_bv = bio_iter_iovec(src, *src_iter); 119545db54d5SKent Overstreet dst_bv = bio_iter_iovec(dst, *dst_iter); 119645db54d5SKent Overstreet 119745db54d5SKent Overstreet bytes = min(src_bv.bv_len, dst_bv.bv_len); 119845db54d5SKent Overstreet 119945db54d5SKent Overstreet src_p = kmap_atomic(src_bv.bv_page); 120045db54d5SKent Overstreet dst_p = kmap_atomic(dst_bv.bv_page); 120145db54d5SKent Overstreet 120245db54d5SKent Overstreet memcpy(dst_p + dst_bv.bv_offset, 120345db54d5SKent Overstreet src_p + src_bv.bv_offset, 120445db54d5SKent Overstreet bytes); 120545db54d5SKent Overstreet 120645db54d5SKent Overstreet kunmap_atomic(dst_p); 120745db54d5SKent Overstreet kunmap_atomic(src_p); 120845db54d5SKent Overstreet 12096e6e811dSKent Overstreet flush_dcache_page(dst_bv.bv_page); 12106e6e811dSKent Overstreet 121122b56c29SPavel Begunkov bio_advance_iter_single(src, src_iter, bytes); 121222b56c29SPavel Begunkov bio_advance_iter_single(dst, dst_iter, bytes); 121345db54d5SKent Overstreet } 121445db54d5SKent Overstreet } 121545db54d5SKent Overstreet EXPORT_SYMBOL(bio_copy_data_iter); 121645db54d5SKent Overstreet 121745db54d5SKent Overstreet /** 121845db54d5SKent Overstreet * bio_copy_data - copy contents of data buffers from one bio to another 121945db54d5SKent Overstreet * @src: source bio 122045db54d5SKent Overstreet * @dst: destination bio 122145db54d5SKent Overstreet * 122245db54d5SKent Overstreet * Stops when it reaches the end of either @src or @dst - that is, copies 122345db54d5SKent Overstreet * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios). 122445db54d5SKent Overstreet */ 122545db54d5SKent Overstreet void bio_copy_data(struct bio *dst, struct bio *src) 122645db54d5SKent Overstreet { 122745db54d5SKent Overstreet struct bvec_iter src_iter = src->bi_iter; 122845db54d5SKent Overstreet struct bvec_iter dst_iter = dst->bi_iter; 122945db54d5SKent Overstreet 123045db54d5SKent Overstreet bio_copy_data_iter(dst, &dst_iter, src, &src_iter); 123145db54d5SKent Overstreet } 123245db54d5SKent Overstreet EXPORT_SYMBOL(bio_copy_data); 123345db54d5SKent Overstreet 1234491221f8SGuoqing Jiang void bio_free_pages(struct bio *bio) 12351dfa0f68SChristoph Hellwig { 12361dfa0f68SChristoph Hellwig struct bio_vec *bvec; 12376dc4f100SMing Lei struct bvec_iter_all iter_all; 12381dfa0f68SChristoph Hellwig 12392b070cfeSChristoph Hellwig bio_for_each_segment_all(bvec, bio, iter_all) 12401dfa0f68SChristoph Hellwig __free_page(bvec->bv_page); 12411dfa0f68SChristoph Hellwig } 1242491221f8SGuoqing Jiang EXPORT_SYMBOL(bio_free_pages); 12431dfa0f68SChristoph Hellwig 1244f9c78b2bSJens Axboe /* 1245f9c78b2bSJens Axboe * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions 1246f9c78b2bSJens Axboe * for performing direct-IO in BIOs. 1247f9c78b2bSJens Axboe * 1248f9c78b2bSJens Axboe * The problem is that we cannot run set_page_dirty() from interrupt context 1249f9c78b2bSJens Axboe * because the required locks are not interrupt-safe. So what we can do is to 1250f9c78b2bSJens Axboe * mark the pages dirty _before_ performing IO. And in interrupt context, 1251f9c78b2bSJens Axboe * check that the pages are still dirty. If so, fine. If not, redirty them 1252f9c78b2bSJens Axboe * in process context. 1253f9c78b2bSJens Axboe * 1254f9c78b2bSJens Axboe * We special-case compound pages here: normally this means reads into hugetlb 1255f9c78b2bSJens Axboe * pages. The logic in here doesn't really work right for compound pages 1256f9c78b2bSJens Axboe * because the VM does not uniformly chase down the head page in all cases. 1257f9c78b2bSJens Axboe * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't 1258f9c78b2bSJens Axboe * handle them at all. So we skip compound pages here at an early stage. 1259f9c78b2bSJens Axboe * 1260f9c78b2bSJens Axboe * Note that this code is very hard to test under normal circumstances because 1261f9c78b2bSJens Axboe * direct-io pins the pages with get_user_pages(). This makes 1262f9c78b2bSJens Axboe * is_page_cache_freeable return false, and the VM will not clean the pages. 1263f9c78b2bSJens Axboe * But other code (eg, flusher threads) could clean the pages if they are mapped 1264f9c78b2bSJens Axboe * pagecache. 1265f9c78b2bSJens Axboe * 1266f9c78b2bSJens Axboe * Simply disabling the call to bio_set_pages_dirty() is a good way to test the 1267f9c78b2bSJens Axboe * deferred bio dirtying paths. 1268f9c78b2bSJens Axboe */ 1269f9c78b2bSJens Axboe 1270f9c78b2bSJens Axboe /* 1271f9c78b2bSJens Axboe * bio_set_pages_dirty() will mark all the bio's pages as dirty. 1272f9c78b2bSJens Axboe */ 1273f9c78b2bSJens Axboe void bio_set_pages_dirty(struct bio *bio) 1274f9c78b2bSJens Axboe { 1275f9c78b2bSJens Axboe struct bio_vec *bvec; 12766dc4f100SMing Lei struct bvec_iter_all iter_all; 1277f9c78b2bSJens Axboe 12782b070cfeSChristoph Hellwig bio_for_each_segment_all(bvec, bio, iter_all) { 12793bb50983SChristoph Hellwig if (!PageCompound(bvec->bv_page)) 12803bb50983SChristoph Hellwig set_page_dirty_lock(bvec->bv_page); 1281f9c78b2bSJens Axboe } 1282f9c78b2bSJens Axboe } 1283f9c78b2bSJens Axboe 1284f9c78b2bSJens Axboe /* 1285f9c78b2bSJens Axboe * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. 1286f9c78b2bSJens Axboe * If they are, then fine. If, however, some pages are clean then they must 1287f9c78b2bSJens Axboe * have been written out during the direct-IO read. So we take another ref on 128824d5493fSChristoph Hellwig * the BIO and re-dirty the pages in process context. 1289f9c78b2bSJens Axboe * 1290f9c78b2bSJens Axboe * It is expected that bio_check_pages_dirty() will wholly own the BIO from 1291ea1754a0SKirill A. Shutemov * here on. It will run one put_page() against each page and will run one 1292ea1754a0SKirill A. Shutemov * bio_put() against the BIO. 1293f9c78b2bSJens Axboe */ 1294f9c78b2bSJens Axboe 1295f9c78b2bSJens Axboe static void bio_dirty_fn(struct work_struct *work); 1296f9c78b2bSJens Axboe 1297f9c78b2bSJens Axboe static DECLARE_WORK(bio_dirty_work, bio_dirty_fn); 1298f9c78b2bSJens Axboe static DEFINE_SPINLOCK(bio_dirty_lock); 1299f9c78b2bSJens Axboe static struct bio *bio_dirty_list; 1300f9c78b2bSJens Axboe 1301f9c78b2bSJens Axboe /* 1302f9c78b2bSJens Axboe * This runs in process context 1303f9c78b2bSJens Axboe */ 1304f9c78b2bSJens Axboe static void bio_dirty_fn(struct work_struct *work) 1305f9c78b2bSJens Axboe { 130624d5493fSChristoph Hellwig struct bio *bio, *next; 1307f9c78b2bSJens Axboe 130824d5493fSChristoph Hellwig spin_lock_irq(&bio_dirty_lock); 130924d5493fSChristoph Hellwig next = bio_dirty_list; 1310f9c78b2bSJens Axboe bio_dirty_list = NULL; 131124d5493fSChristoph Hellwig spin_unlock_irq(&bio_dirty_lock); 1312f9c78b2bSJens Axboe 131324d5493fSChristoph Hellwig while ((bio = next) != NULL) { 131424d5493fSChristoph Hellwig next = bio->bi_private; 1315f9c78b2bSJens Axboe 1316d241a95fSChristoph Hellwig bio_release_pages(bio, true); 1317f9c78b2bSJens Axboe bio_put(bio); 1318f9c78b2bSJens Axboe } 1319f9c78b2bSJens Axboe } 1320f9c78b2bSJens Axboe 1321f9c78b2bSJens Axboe void bio_check_pages_dirty(struct bio *bio) 1322f9c78b2bSJens Axboe { 1323f9c78b2bSJens Axboe struct bio_vec *bvec; 132424d5493fSChristoph Hellwig unsigned long flags; 13256dc4f100SMing Lei struct bvec_iter_all iter_all; 1326f9c78b2bSJens Axboe 13272b070cfeSChristoph Hellwig bio_for_each_segment_all(bvec, bio, iter_all) { 132824d5493fSChristoph Hellwig if (!PageDirty(bvec->bv_page) && !PageCompound(bvec->bv_page)) 132924d5493fSChristoph Hellwig goto defer; 1330f9c78b2bSJens Axboe } 1331f9c78b2bSJens Axboe 1332d241a95fSChristoph Hellwig bio_release_pages(bio, false); 133324d5493fSChristoph Hellwig bio_put(bio); 133424d5493fSChristoph Hellwig return; 133524d5493fSChristoph Hellwig defer: 1336f9c78b2bSJens Axboe spin_lock_irqsave(&bio_dirty_lock, flags); 1337f9c78b2bSJens Axboe bio->bi_private = bio_dirty_list; 1338f9c78b2bSJens Axboe bio_dirty_list = bio; 1339f9c78b2bSJens Axboe spin_unlock_irqrestore(&bio_dirty_lock, flags); 1340f9c78b2bSJens Axboe schedule_work(&bio_dirty_work); 1341f9c78b2bSJens Axboe } 1342f9c78b2bSJens Axboe 1343c4cf5261SJens Axboe static inline bool bio_remaining_done(struct bio *bio) 1344c4cf5261SJens Axboe { 1345c4cf5261SJens Axboe /* 1346c4cf5261SJens Axboe * If we're not chaining, then ->__bi_remaining is always 1 and 1347c4cf5261SJens Axboe * we always end io on the first invocation. 1348c4cf5261SJens Axboe */ 1349c4cf5261SJens Axboe if (!bio_flagged(bio, BIO_CHAIN)) 1350c4cf5261SJens Axboe return true; 1351c4cf5261SJens Axboe 1352c4cf5261SJens Axboe BUG_ON(atomic_read(&bio->__bi_remaining) <= 0); 1353c4cf5261SJens Axboe 1354326e1dbbSMike Snitzer if (atomic_dec_and_test(&bio->__bi_remaining)) { 1355b7c44ed9SJens Axboe bio_clear_flag(bio, BIO_CHAIN); 1356c4cf5261SJens Axboe return true; 1357326e1dbbSMike Snitzer } 1358c4cf5261SJens Axboe 1359c4cf5261SJens Axboe return false; 1360c4cf5261SJens Axboe } 1361c4cf5261SJens Axboe 1362f9c78b2bSJens Axboe /** 1363f9c78b2bSJens Axboe * bio_endio - end I/O on a bio 1364f9c78b2bSJens Axboe * @bio: bio 1365f9c78b2bSJens Axboe * 1366f9c78b2bSJens Axboe * Description: 13674246a0b6SChristoph Hellwig * bio_endio() will end I/O on the whole bio. bio_endio() is the preferred 13684246a0b6SChristoph Hellwig * way to end I/O on a bio. No one should call bi_end_io() directly on a 13694246a0b6SChristoph Hellwig * bio unless they own it and thus know that it has an end_io function. 1370fbbaf700SNeilBrown * 1371fbbaf700SNeilBrown * bio_endio() can be called several times on a bio that has been chained 1372fbbaf700SNeilBrown * using bio_chain(). The ->bi_end_io() function will only be called the 137360b6a7e6SEdward Hsieh * last time. 1374f9c78b2bSJens Axboe **/ 13754246a0b6SChristoph Hellwig void bio_endio(struct bio *bio) 1376f9c78b2bSJens Axboe { 1377ba8c6967SChristoph Hellwig again: 13782b885517SChristoph Hellwig if (!bio_remaining_done(bio)) 1379ba8c6967SChristoph Hellwig return; 13807c20f116SChristoph Hellwig if (!bio_integrity_endio(bio)) 13817c20f116SChristoph Hellwig return; 1382f9c78b2bSJens Axboe 1383309dca30SChristoph Hellwig if (bio->bi_bdev) 1384309dca30SChristoph Hellwig rq_qos_done_bio(bio->bi_bdev->bd_disk->queue, bio); 138567b42d0bSJosef Bacik 138660b6a7e6SEdward Hsieh if (bio->bi_bdev && bio_flagged(bio, BIO_TRACE_COMPLETION)) { 138760b6a7e6SEdward Hsieh trace_block_bio_complete(bio->bi_bdev->bd_disk->queue, bio); 138860b6a7e6SEdward Hsieh bio_clear_flag(bio, BIO_TRACE_COMPLETION); 138960b6a7e6SEdward Hsieh } 139060b6a7e6SEdward Hsieh 1391f9c78b2bSJens Axboe /* 1392ba8c6967SChristoph Hellwig * Need to have a real endio function for chained bios, otherwise 1393ba8c6967SChristoph Hellwig * various corner cases will break (like stacking block devices that 1394ba8c6967SChristoph Hellwig * save/restore bi_end_io) - however, we want to avoid unbounded 1395ba8c6967SChristoph Hellwig * recursion and blowing the stack. Tail call optimization would 1396ba8c6967SChristoph Hellwig * handle this, but compiling with frame pointers also disables 1397ba8c6967SChristoph Hellwig * gcc's sibling call optimization. 1398f9c78b2bSJens Axboe */ 1399f9c78b2bSJens Axboe if (bio->bi_end_io == bio_chain_endio) { 140038f8baaeSChristoph Hellwig bio = __bio_chain_endio(bio); 1401ba8c6967SChristoph Hellwig goto again; 1402ba8c6967SChristoph Hellwig } 1403ba8c6967SChristoph Hellwig 14049e234eeaSShaohua Li blk_throtl_bio_endio(bio); 1405b222dd2fSShaohua Li /* release cgroup info */ 1406b222dd2fSShaohua Li bio_uninit(bio); 1407f9c78b2bSJens Axboe if (bio->bi_end_io) 14084246a0b6SChristoph Hellwig bio->bi_end_io(bio); 1409f9c78b2bSJens Axboe } 1410f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_endio); 1411f9c78b2bSJens Axboe 1412f9c78b2bSJens Axboe /** 1413f9c78b2bSJens Axboe * bio_split - split a bio 1414f9c78b2bSJens Axboe * @bio: bio to split 1415f9c78b2bSJens Axboe * @sectors: number of sectors to split from the front of @bio 1416f9c78b2bSJens Axboe * @gfp: gfp mask 1417f9c78b2bSJens Axboe * @bs: bio set to allocate from 1418f9c78b2bSJens Axboe * 1419f9c78b2bSJens Axboe * Allocates and returns a new bio which represents @sectors from the start of 1420f9c78b2bSJens Axboe * @bio, and updates @bio to represent the remaining sectors. 1421f9c78b2bSJens Axboe * 1422f3f5da62SMartin K. Petersen * Unless this is a discard request the newly allocated bio will point 1423dad77584SBart Van Assche * to @bio's bi_io_vec. It is the caller's responsibility to ensure that 1424dad77584SBart Van Assche * neither @bio nor @bs are freed before the split bio. 1425f9c78b2bSJens Axboe */ 1426f9c78b2bSJens Axboe struct bio *bio_split(struct bio *bio, int sectors, 1427f9c78b2bSJens Axboe gfp_t gfp, struct bio_set *bs) 1428f9c78b2bSJens Axboe { 1429f341a4d3SMikulas Patocka struct bio *split; 1430f9c78b2bSJens Axboe 1431f9c78b2bSJens Axboe BUG_ON(sectors <= 0); 1432f9c78b2bSJens Axboe BUG_ON(sectors >= bio_sectors(bio)); 1433f9c78b2bSJens Axboe 14340512a75bSKeith Busch /* Zone append commands cannot be split */ 14350512a75bSKeith Busch if (WARN_ON_ONCE(bio_op(bio) == REQ_OP_ZONE_APPEND)) 14360512a75bSKeith Busch return NULL; 14370512a75bSKeith Busch 1438f9c78b2bSJens Axboe split = bio_clone_fast(bio, gfp, bs); 1439f9c78b2bSJens Axboe if (!split) 1440f9c78b2bSJens Axboe return NULL; 1441f9c78b2bSJens Axboe 1442f9c78b2bSJens Axboe split->bi_iter.bi_size = sectors << 9; 1443f9c78b2bSJens Axboe 1444f9c78b2bSJens Axboe if (bio_integrity(split)) 1445fbd08e76SDmitry Monakhov bio_integrity_trim(split); 1446f9c78b2bSJens Axboe 1447f9c78b2bSJens Axboe bio_advance(bio, split->bi_iter.bi_size); 1448f9c78b2bSJens Axboe 1449fbbaf700SNeilBrown if (bio_flagged(bio, BIO_TRACE_COMPLETION)) 145020d59023SGoldwyn Rodrigues bio_set_flag(split, BIO_TRACE_COMPLETION); 1451fbbaf700SNeilBrown 1452f9c78b2bSJens Axboe return split; 1453f9c78b2bSJens Axboe } 1454f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_split); 1455f9c78b2bSJens Axboe 1456f9c78b2bSJens Axboe /** 1457f9c78b2bSJens Axboe * bio_trim - trim a bio 1458f9c78b2bSJens Axboe * @bio: bio to trim 1459f9c78b2bSJens Axboe * @offset: number of sectors to trim from the front of @bio 1460f9c78b2bSJens Axboe * @size: size we want to trim @bio to, in sectors 1461f9c78b2bSJens Axboe */ 1462f9c78b2bSJens Axboe void bio_trim(struct bio *bio, int offset, int size) 1463f9c78b2bSJens Axboe { 1464f9c78b2bSJens Axboe /* 'bio' is a cloned bio which we need to trim to match 1465f9c78b2bSJens Axboe * the given offset and size. 1466f9c78b2bSJens Axboe */ 1467f9c78b2bSJens Axboe 1468f9c78b2bSJens Axboe size <<= 9; 1469f9c78b2bSJens Axboe if (offset == 0 && size == bio->bi_iter.bi_size) 1470f9c78b2bSJens Axboe return; 1471f9c78b2bSJens Axboe 1472f9c78b2bSJens Axboe bio_advance(bio, offset << 9); 1473f9c78b2bSJens Axboe bio->bi_iter.bi_size = size; 1474376a78abSDmitry Monakhov 1475376a78abSDmitry Monakhov if (bio_integrity(bio)) 1476fbd08e76SDmitry Monakhov bio_integrity_trim(bio); 1477376a78abSDmitry Monakhov 1478f9c78b2bSJens Axboe } 1479f9c78b2bSJens Axboe EXPORT_SYMBOL_GPL(bio_trim); 1480f9c78b2bSJens Axboe 1481f9c78b2bSJens Axboe /* 1482f9c78b2bSJens Axboe * create memory pools for biovec's in a bio_set. 1483f9c78b2bSJens Axboe * use the global biovec slabs created for general use. 1484f9c78b2bSJens Axboe */ 14858aa6ba2fSKent Overstreet int biovec_init_pool(mempool_t *pool, int pool_entries) 1486f9c78b2bSJens Axboe { 14877a800a20SChristoph Hellwig struct biovec_slab *bp = bvec_slabs + ARRAY_SIZE(bvec_slabs) - 1; 1488f9c78b2bSJens Axboe 14898aa6ba2fSKent Overstreet return mempool_init_slab_pool(pool, pool_entries, bp->slab); 1490f9c78b2bSJens Axboe } 1491f9c78b2bSJens Axboe 1492917a38c7SKent Overstreet /* 1493917a38c7SKent Overstreet * bioset_exit - exit a bioset initialized with bioset_init() 1494917a38c7SKent Overstreet * 1495917a38c7SKent Overstreet * May be called on a zeroed but uninitialized bioset (i.e. allocated with 1496917a38c7SKent Overstreet * kzalloc()). 1497917a38c7SKent Overstreet */ 1498917a38c7SKent Overstreet void bioset_exit(struct bio_set *bs) 1499f9c78b2bSJens Axboe { 1500f9c78b2bSJens Axboe if (bs->rescue_workqueue) 1501f9c78b2bSJens Axboe destroy_workqueue(bs->rescue_workqueue); 1502917a38c7SKent Overstreet bs->rescue_workqueue = NULL; 1503f9c78b2bSJens Axboe 15048aa6ba2fSKent Overstreet mempool_exit(&bs->bio_pool); 15058aa6ba2fSKent Overstreet mempool_exit(&bs->bvec_pool); 1506f9c78b2bSJens Axboe 1507f9c78b2bSJens Axboe bioset_integrity_free(bs); 1508917a38c7SKent Overstreet if (bs->bio_slab) 1509f9c78b2bSJens Axboe bio_put_slab(bs); 1510917a38c7SKent Overstreet bs->bio_slab = NULL; 1511917a38c7SKent Overstreet } 1512917a38c7SKent Overstreet EXPORT_SYMBOL(bioset_exit); 1513f9c78b2bSJens Axboe 1514011067b0SNeilBrown /** 1515917a38c7SKent Overstreet * bioset_init - Initialize a bio_set 1516dad08527SKent Overstreet * @bs: pool to initialize 1517917a38c7SKent Overstreet * @pool_size: Number of bio and bio_vecs to cache in the mempool 1518917a38c7SKent Overstreet * @front_pad: Number of bytes to allocate in front of the returned bio 1519917a38c7SKent Overstreet * @flags: Flags to modify behavior, currently %BIOSET_NEED_BVECS 1520917a38c7SKent Overstreet * and %BIOSET_NEED_RESCUER 1521917a38c7SKent Overstreet * 1522dad08527SKent Overstreet * Description: 1523dad08527SKent Overstreet * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller 1524dad08527SKent Overstreet * to ask for a number of bytes to be allocated in front of the bio. 1525dad08527SKent Overstreet * Front pad allocation is useful for embedding the bio inside 1526dad08527SKent Overstreet * another structure, to avoid allocating extra data to go with the bio. 1527dad08527SKent Overstreet * Note that the bio must be embedded at the END of that structure always, 1528dad08527SKent Overstreet * or things will break badly. 1529dad08527SKent Overstreet * If %BIOSET_NEED_BVECS is set in @flags, a separate pool will be allocated 1530dad08527SKent Overstreet * for allocating iovecs. This pool is not needed e.g. for bio_clone_fast(). 1531dad08527SKent Overstreet * If %BIOSET_NEED_RESCUER is set, a workqueue is created which can be used to 1532dad08527SKent Overstreet * dispatch queued requests when the mempool runs out of space. 1533dad08527SKent Overstreet * 1534917a38c7SKent Overstreet */ 1535917a38c7SKent Overstreet int bioset_init(struct bio_set *bs, 1536917a38c7SKent Overstreet unsigned int pool_size, 1537917a38c7SKent Overstreet unsigned int front_pad, 1538917a38c7SKent Overstreet int flags) 1539917a38c7SKent Overstreet { 1540917a38c7SKent Overstreet bs->front_pad = front_pad; 15419f180e31SMing Lei if (flags & BIOSET_NEED_BVECS) 15429f180e31SMing Lei bs->back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec); 15439f180e31SMing Lei else 15449f180e31SMing Lei bs->back_pad = 0; 1545917a38c7SKent Overstreet 1546917a38c7SKent Overstreet spin_lock_init(&bs->rescue_lock); 1547917a38c7SKent Overstreet bio_list_init(&bs->rescue_list); 1548917a38c7SKent Overstreet INIT_WORK(&bs->rescue_work, bio_alloc_rescue); 1549917a38c7SKent Overstreet 155049d1ec85SMing Lei bs->bio_slab = bio_find_or_create_slab(bs); 1551917a38c7SKent Overstreet if (!bs->bio_slab) 1552917a38c7SKent Overstreet return -ENOMEM; 1553917a38c7SKent Overstreet 1554917a38c7SKent Overstreet if (mempool_init_slab_pool(&bs->bio_pool, pool_size, bs->bio_slab)) 1555917a38c7SKent Overstreet goto bad; 1556917a38c7SKent Overstreet 1557917a38c7SKent Overstreet if ((flags & BIOSET_NEED_BVECS) && 1558917a38c7SKent Overstreet biovec_init_pool(&bs->bvec_pool, pool_size)) 1559917a38c7SKent Overstreet goto bad; 1560917a38c7SKent Overstreet 1561917a38c7SKent Overstreet if (!(flags & BIOSET_NEED_RESCUER)) 1562917a38c7SKent Overstreet return 0; 1563917a38c7SKent Overstreet 1564917a38c7SKent Overstreet bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0); 1565917a38c7SKent Overstreet if (!bs->rescue_workqueue) 1566917a38c7SKent Overstreet goto bad; 1567917a38c7SKent Overstreet 1568917a38c7SKent Overstreet return 0; 1569917a38c7SKent Overstreet bad: 1570917a38c7SKent Overstreet bioset_exit(bs); 1571917a38c7SKent Overstreet return -ENOMEM; 1572917a38c7SKent Overstreet } 1573917a38c7SKent Overstreet EXPORT_SYMBOL(bioset_init); 1574917a38c7SKent Overstreet 157528e89fd9SJens Axboe /* 157628e89fd9SJens Axboe * Initialize and setup a new bio_set, based on the settings from 157728e89fd9SJens Axboe * another bio_set. 157828e89fd9SJens Axboe */ 157928e89fd9SJens Axboe int bioset_init_from_src(struct bio_set *bs, struct bio_set *src) 158028e89fd9SJens Axboe { 158128e89fd9SJens Axboe int flags; 158228e89fd9SJens Axboe 158328e89fd9SJens Axboe flags = 0; 158428e89fd9SJens Axboe if (src->bvec_pool.min_nr) 158528e89fd9SJens Axboe flags |= BIOSET_NEED_BVECS; 158628e89fd9SJens Axboe if (src->rescue_workqueue) 158728e89fd9SJens Axboe flags |= BIOSET_NEED_RESCUER; 158828e89fd9SJens Axboe 158928e89fd9SJens Axboe return bioset_init(bs, src->bio_pool.min_nr, src->front_pad, flags); 159028e89fd9SJens Axboe } 159128e89fd9SJens Axboe EXPORT_SYMBOL(bioset_init_from_src); 159228e89fd9SJens Axboe 1593de76fd89SChristoph Hellwig static int __init init_bio(void) 1594f9c78b2bSJens Axboe { 1595f9c78b2bSJens Axboe int i; 1596f9c78b2bSJens Axboe 1597f9c78b2bSJens Axboe bio_integrity_init(); 1598de76fd89SChristoph Hellwig 1599de76fd89SChristoph Hellwig for (i = 0; i < ARRAY_SIZE(bvec_slabs); i++) { 1600f9c78b2bSJens Axboe struct biovec_slab *bvs = bvec_slabs + i; 1601f9c78b2bSJens Axboe 1602de76fd89SChristoph Hellwig bvs->slab = kmem_cache_create(bvs->name, 1603de76fd89SChristoph Hellwig bvs->nr_vecs * sizeof(struct bio_vec), 0, 1604f9c78b2bSJens Axboe SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); 1605f9c78b2bSJens Axboe } 1606f9c78b2bSJens Axboe 1607f4f8154aSKent Overstreet if (bioset_init(&fs_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS)) 1608f9c78b2bSJens Axboe panic("bio: can't allocate bios\n"); 1609f9c78b2bSJens Axboe 1610f4f8154aSKent Overstreet if (bioset_integrity_create(&fs_bio_set, BIO_POOL_SIZE)) 1611f9c78b2bSJens Axboe panic("bio: can't create integrity pool\n"); 1612f9c78b2bSJens Axboe 1613f9c78b2bSJens Axboe return 0; 1614f9c78b2bSJens Axboe } 1615f9c78b2bSJens Axboe subsys_initcall(init_bio); 1616