1f9c78b2bSJens Axboe /* 2f9c78b2bSJens Axboe * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk> 3f9c78b2bSJens Axboe * 4f9c78b2bSJens Axboe * This program is free software; you can redistribute it and/or modify 5f9c78b2bSJens Axboe * it under the terms of the GNU General Public License version 2 as 6f9c78b2bSJens Axboe * published by the Free Software Foundation. 7f9c78b2bSJens Axboe * 8f9c78b2bSJens Axboe * This program is distributed in the hope that it will be useful, 9f9c78b2bSJens Axboe * but WITHOUT ANY WARRANTY; without even the implied warranty of 10f9c78b2bSJens Axboe * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11f9c78b2bSJens Axboe * GNU General Public License for more details. 12f9c78b2bSJens Axboe * 13f9c78b2bSJens Axboe * You should have received a copy of the GNU General Public Licens 14f9c78b2bSJens Axboe * along with this program; if not, write to the Free Software 15f9c78b2bSJens Axboe * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- 16f9c78b2bSJens Axboe * 17f9c78b2bSJens Axboe */ 18f9c78b2bSJens Axboe #include <linux/mm.h> 19f9c78b2bSJens Axboe #include <linux/swap.h> 20f9c78b2bSJens Axboe #include <linux/bio.h> 21f9c78b2bSJens Axboe #include <linux/blkdev.h> 22f9c78b2bSJens Axboe #include <linux/uio.h> 23f9c78b2bSJens Axboe #include <linux/iocontext.h> 24f9c78b2bSJens Axboe #include <linux/slab.h> 25f9c78b2bSJens Axboe #include <linux/init.h> 26f9c78b2bSJens Axboe #include <linux/kernel.h> 27f9c78b2bSJens Axboe #include <linux/export.h> 28f9c78b2bSJens Axboe #include <linux/mempool.h> 29f9c78b2bSJens Axboe #include <linux/workqueue.h> 30f9c78b2bSJens Axboe #include <linux/cgroup.h> 31f9c78b2bSJens Axboe 32f9c78b2bSJens Axboe #include <trace/events/block.h> 33f9c78b2bSJens Axboe 34f9c78b2bSJens Axboe /* 35f9c78b2bSJens Axboe * Test patch to inline a certain number of bi_io_vec's inside the bio 36f9c78b2bSJens Axboe * itself, to shrink a bio data allocation from two mempool calls to one 37f9c78b2bSJens Axboe */ 38f9c78b2bSJens Axboe #define BIO_INLINE_VECS 4 39f9c78b2bSJens Axboe 40f9c78b2bSJens Axboe /* 41f9c78b2bSJens Axboe * if you change this list, also change bvec_alloc or things will 42f9c78b2bSJens Axboe * break badly! cannot be bigger than what you can fit into an 43f9c78b2bSJens Axboe * unsigned short 44f9c78b2bSJens Axboe */ 45f9c78b2bSJens Axboe #define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) } 46f9c78b2bSJens Axboe static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { 47f9c78b2bSJens Axboe BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES), 48f9c78b2bSJens Axboe }; 49f9c78b2bSJens Axboe #undef BV 50f9c78b2bSJens Axboe 51f9c78b2bSJens Axboe /* 52f9c78b2bSJens Axboe * fs_bio_set is the bio_set containing bio and iovec memory pools used by 53f9c78b2bSJens Axboe * IO code that does not need private memory pools. 54f9c78b2bSJens Axboe */ 55f9c78b2bSJens Axboe struct bio_set *fs_bio_set; 56f9c78b2bSJens Axboe EXPORT_SYMBOL(fs_bio_set); 57f9c78b2bSJens Axboe 58f9c78b2bSJens Axboe /* 59f9c78b2bSJens Axboe * Our slab pool management 60f9c78b2bSJens Axboe */ 61f9c78b2bSJens Axboe struct bio_slab { 62f9c78b2bSJens Axboe struct kmem_cache *slab; 63f9c78b2bSJens Axboe unsigned int slab_ref; 64f9c78b2bSJens Axboe unsigned int slab_size; 65f9c78b2bSJens Axboe char name[8]; 66f9c78b2bSJens Axboe }; 67f9c78b2bSJens Axboe static DEFINE_MUTEX(bio_slab_lock); 68f9c78b2bSJens Axboe static struct bio_slab *bio_slabs; 69f9c78b2bSJens Axboe static unsigned int bio_slab_nr, bio_slab_max; 70f9c78b2bSJens Axboe 71f9c78b2bSJens Axboe static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size) 72f9c78b2bSJens Axboe { 73f9c78b2bSJens Axboe unsigned int sz = sizeof(struct bio) + extra_size; 74f9c78b2bSJens Axboe struct kmem_cache *slab = NULL; 75f9c78b2bSJens Axboe struct bio_slab *bslab, *new_bio_slabs; 76f9c78b2bSJens Axboe unsigned int new_bio_slab_max; 77f9c78b2bSJens Axboe unsigned int i, entry = -1; 78f9c78b2bSJens Axboe 79f9c78b2bSJens Axboe mutex_lock(&bio_slab_lock); 80f9c78b2bSJens Axboe 81f9c78b2bSJens Axboe i = 0; 82f9c78b2bSJens Axboe while (i < bio_slab_nr) { 83f9c78b2bSJens Axboe bslab = &bio_slabs[i]; 84f9c78b2bSJens Axboe 85f9c78b2bSJens Axboe if (!bslab->slab && entry == -1) 86f9c78b2bSJens Axboe entry = i; 87f9c78b2bSJens Axboe else if (bslab->slab_size == sz) { 88f9c78b2bSJens Axboe slab = bslab->slab; 89f9c78b2bSJens Axboe bslab->slab_ref++; 90f9c78b2bSJens Axboe break; 91f9c78b2bSJens Axboe } 92f9c78b2bSJens Axboe i++; 93f9c78b2bSJens Axboe } 94f9c78b2bSJens Axboe 95f9c78b2bSJens Axboe if (slab) 96f9c78b2bSJens Axboe goto out_unlock; 97f9c78b2bSJens Axboe 98f9c78b2bSJens Axboe if (bio_slab_nr == bio_slab_max && entry == -1) { 99f9c78b2bSJens Axboe new_bio_slab_max = bio_slab_max << 1; 100f9c78b2bSJens Axboe new_bio_slabs = krealloc(bio_slabs, 101f9c78b2bSJens Axboe new_bio_slab_max * sizeof(struct bio_slab), 102f9c78b2bSJens Axboe GFP_KERNEL); 103f9c78b2bSJens Axboe if (!new_bio_slabs) 104f9c78b2bSJens Axboe goto out_unlock; 105f9c78b2bSJens Axboe bio_slab_max = new_bio_slab_max; 106f9c78b2bSJens Axboe bio_slabs = new_bio_slabs; 107f9c78b2bSJens Axboe } 108f9c78b2bSJens Axboe if (entry == -1) 109f9c78b2bSJens Axboe entry = bio_slab_nr++; 110f9c78b2bSJens Axboe 111f9c78b2bSJens Axboe bslab = &bio_slabs[entry]; 112f9c78b2bSJens Axboe 113f9c78b2bSJens Axboe snprintf(bslab->name, sizeof(bslab->name), "bio-%d", entry); 1146a241483SMikulas Patocka slab = kmem_cache_create(bslab->name, sz, ARCH_KMALLOC_MINALIGN, 1156a241483SMikulas Patocka SLAB_HWCACHE_ALIGN, NULL); 116f9c78b2bSJens Axboe if (!slab) 117f9c78b2bSJens Axboe goto out_unlock; 118f9c78b2bSJens Axboe 119f9c78b2bSJens Axboe bslab->slab = slab; 120f9c78b2bSJens Axboe bslab->slab_ref = 1; 121f9c78b2bSJens Axboe bslab->slab_size = sz; 122f9c78b2bSJens Axboe out_unlock: 123f9c78b2bSJens Axboe mutex_unlock(&bio_slab_lock); 124f9c78b2bSJens Axboe return slab; 125f9c78b2bSJens Axboe } 126f9c78b2bSJens Axboe 127f9c78b2bSJens Axboe static void bio_put_slab(struct bio_set *bs) 128f9c78b2bSJens Axboe { 129f9c78b2bSJens Axboe struct bio_slab *bslab = NULL; 130f9c78b2bSJens Axboe unsigned int i; 131f9c78b2bSJens Axboe 132f9c78b2bSJens Axboe mutex_lock(&bio_slab_lock); 133f9c78b2bSJens Axboe 134f9c78b2bSJens Axboe for (i = 0; i < bio_slab_nr; i++) { 135f9c78b2bSJens Axboe if (bs->bio_slab == bio_slabs[i].slab) { 136f9c78b2bSJens Axboe bslab = &bio_slabs[i]; 137f9c78b2bSJens Axboe break; 138f9c78b2bSJens Axboe } 139f9c78b2bSJens Axboe } 140f9c78b2bSJens Axboe 141f9c78b2bSJens Axboe if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n")) 142f9c78b2bSJens Axboe goto out; 143f9c78b2bSJens Axboe 144f9c78b2bSJens Axboe WARN_ON(!bslab->slab_ref); 145f9c78b2bSJens Axboe 146f9c78b2bSJens Axboe if (--bslab->slab_ref) 147f9c78b2bSJens Axboe goto out; 148f9c78b2bSJens Axboe 149f9c78b2bSJens Axboe kmem_cache_destroy(bslab->slab); 150f9c78b2bSJens Axboe bslab->slab = NULL; 151f9c78b2bSJens Axboe 152f9c78b2bSJens Axboe out: 153f9c78b2bSJens Axboe mutex_unlock(&bio_slab_lock); 154f9c78b2bSJens Axboe } 155f9c78b2bSJens Axboe 156f9c78b2bSJens Axboe unsigned int bvec_nr_vecs(unsigned short idx) 157f9c78b2bSJens Axboe { 158f9c78b2bSJens Axboe return bvec_slabs[idx].nr_vecs; 159f9c78b2bSJens Axboe } 160f9c78b2bSJens Axboe 161f9c78b2bSJens Axboe void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned int idx) 162f9c78b2bSJens Axboe { 163f9c78b2bSJens Axboe BIO_BUG_ON(idx >= BIOVEC_NR_POOLS); 164f9c78b2bSJens Axboe 165f9c78b2bSJens Axboe if (idx == BIOVEC_MAX_IDX) 166f9c78b2bSJens Axboe mempool_free(bv, pool); 167f9c78b2bSJens Axboe else { 168f9c78b2bSJens Axboe struct biovec_slab *bvs = bvec_slabs + idx; 169f9c78b2bSJens Axboe 170f9c78b2bSJens Axboe kmem_cache_free(bvs->slab, bv); 171f9c78b2bSJens Axboe } 172f9c78b2bSJens Axboe } 173f9c78b2bSJens Axboe 174f9c78b2bSJens Axboe struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx, 175f9c78b2bSJens Axboe mempool_t *pool) 176f9c78b2bSJens Axboe { 177f9c78b2bSJens Axboe struct bio_vec *bvl; 178f9c78b2bSJens Axboe 179f9c78b2bSJens Axboe /* 180f9c78b2bSJens Axboe * see comment near bvec_array define! 181f9c78b2bSJens Axboe */ 182f9c78b2bSJens Axboe switch (nr) { 183f9c78b2bSJens Axboe case 1: 184f9c78b2bSJens Axboe *idx = 0; 185f9c78b2bSJens Axboe break; 186f9c78b2bSJens Axboe case 2 ... 4: 187f9c78b2bSJens Axboe *idx = 1; 188f9c78b2bSJens Axboe break; 189f9c78b2bSJens Axboe case 5 ... 16: 190f9c78b2bSJens Axboe *idx = 2; 191f9c78b2bSJens Axboe break; 192f9c78b2bSJens Axboe case 17 ... 64: 193f9c78b2bSJens Axboe *idx = 3; 194f9c78b2bSJens Axboe break; 195f9c78b2bSJens Axboe case 65 ... 128: 196f9c78b2bSJens Axboe *idx = 4; 197f9c78b2bSJens Axboe break; 198f9c78b2bSJens Axboe case 129 ... BIO_MAX_PAGES: 199f9c78b2bSJens Axboe *idx = 5; 200f9c78b2bSJens Axboe break; 201f9c78b2bSJens Axboe default: 202f9c78b2bSJens Axboe return NULL; 203f9c78b2bSJens Axboe } 204f9c78b2bSJens Axboe 205f9c78b2bSJens Axboe /* 206f9c78b2bSJens Axboe * idx now points to the pool we want to allocate from. only the 207f9c78b2bSJens Axboe * 1-vec entry pool is mempool backed. 208f9c78b2bSJens Axboe */ 209f9c78b2bSJens Axboe if (*idx == BIOVEC_MAX_IDX) { 210f9c78b2bSJens Axboe fallback: 211f9c78b2bSJens Axboe bvl = mempool_alloc(pool, gfp_mask); 212f9c78b2bSJens Axboe } else { 213f9c78b2bSJens Axboe struct biovec_slab *bvs = bvec_slabs + *idx; 214d0164adcSMel Gorman gfp_t __gfp_mask = gfp_mask & ~(__GFP_DIRECT_RECLAIM | __GFP_IO); 215f9c78b2bSJens Axboe 216f9c78b2bSJens Axboe /* 217f9c78b2bSJens Axboe * Make this allocation restricted and don't dump info on 218f9c78b2bSJens Axboe * allocation failures, since we'll fallback to the mempool 219f9c78b2bSJens Axboe * in case of failure. 220f9c78b2bSJens Axboe */ 221f9c78b2bSJens Axboe __gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; 222f9c78b2bSJens Axboe 223f9c78b2bSJens Axboe /* 224d0164adcSMel Gorman * Try a slab allocation. If this fails and __GFP_DIRECT_RECLAIM 225f9c78b2bSJens Axboe * is set, retry with the 1-entry mempool 226f9c78b2bSJens Axboe */ 227f9c78b2bSJens Axboe bvl = kmem_cache_alloc(bvs->slab, __gfp_mask); 228d0164adcSMel Gorman if (unlikely(!bvl && (gfp_mask & __GFP_DIRECT_RECLAIM))) { 229f9c78b2bSJens Axboe *idx = BIOVEC_MAX_IDX; 230f9c78b2bSJens Axboe goto fallback; 231f9c78b2bSJens Axboe } 232f9c78b2bSJens Axboe } 233f9c78b2bSJens Axboe 234f9c78b2bSJens Axboe return bvl; 235f9c78b2bSJens Axboe } 236f9c78b2bSJens Axboe 237f9c78b2bSJens Axboe static void __bio_free(struct bio *bio) 238f9c78b2bSJens Axboe { 239f9c78b2bSJens Axboe bio_disassociate_task(bio); 240f9c78b2bSJens Axboe 241f9c78b2bSJens Axboe if (bio_integrity(bio)) 242f9c78b2bSJens Axboe bio_integrity_free(bio); 243f9c78b2bSJens Axboe } 244f9c78b2bSJens Axboe 245f9c78b2bSJens Axboe static void bio_free(struct bio *bio) 246f9c78b2bSJens Axboe { 247f9c78b2bSJens Axboe struct bio_set *bs = bio->bi_pool; 248f9c78b2bSJens Axboe void *p; 249f9c78b2bSJens Axboe 250f9c78b2bSJens Axboe __bio_free(bio); 251f9c78b2bSJens Axboe 252f9c78b2bSJens Axboe if (bs) { 253f9c78b2bSJens Axboe if (bio_flagged(bio, BIO_OWNS_VEC)) 254f9c78b2bSJens Axboe bvec_free(bs->bvec_pool, bio->bi_io_vec, BIO_POOL_IDX(bio)); 255f9c78b2bSJens Axboe 256f9c78b2bSJens Axboe /* 257f9c78b2bSJens Axboe * If we have front padding, adjust the bio pointer before freeing 258f9c78b2bSJens Axboe */ 259f9c78b2bSJens Axboe p = bio; 260f9c78b2bSJens Axboe p -= bs->front_pad; 261f9c78b2bSJens Axboe 262f9c78b2bSJens Axboe mempool_free(p, bs->bio_pool); 263f9c78b2bSJens Axboe } else { 264f9c78b2bSJens Axboe /* Bio was allocated by bio_kmalloc() */ 265f9c78b2bSJens Axboe kfree(bio); 266f9c78b2bSJens Axboe } 267f9c78b2bSJens Axboe } 268f9c78b2bSJens Axboe 269f9c78b2bSJens Axboe void bio_init(struct bio *bio) 270f9c78b2bSJens Axboe { 271f9c78b2bSJens Axboe memset(bio, 0, sizeof(*bio)); 272c4cf5261SJens Axboe atomic_set(&bio->__bi_remaining, 1); 273dac56212SJens Axboe atomic_set(&bio->__bi_cnt, 1); 274f9c78b2bSJens Axboe } 275f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_init); 276f9c78b2bSJens Axboe 277f9c78b2bSJens Axboe /** 278f9c78b2bSJens Axboe * bio_reset - reinitialize a bio 279f9c78b2bSJens Axboe * @bio: bio to reset 280f9c78b2bSJens Axboe * 281f9c78b2bSJens Axboe * Description: 282f9c78b2bSJens Axboe * After calling bio_reset(), @bio will be in the same state as a freshly 283f9c78b2bSJens Axboe * allocated bio returned bio bio_alloc_bioset() - the only fields that are 284f9c78b2bSJens Axboe * preserved are the ones that are initialized by bio_alloc_bioset(). See 285f9c78b2bSJens Axboe * comment in struct bio. 286f9c78b2bSJens Axboe */ 287f9c78b2bSJens Axboe void bio_reset(struct bio *bio) 288f9c78b2bSJens Axboe { 289f9c78b2bSJens Axboe unsigned long flags = bio->bi_flags & (~0UL << BIO_RESET_BITS); 290f9c78b2bSJens Axboe 291f9c78b2bSJens Axboe __bio_free(bio); 292f9c78b2bSJens Axboe 293f9c78b2bSJens Axboe memset(bio, 0, BIO_RESET_BYTES); 2944246a0b6SChristoph Hellwig bio->bi_flags = flags; 295c4cf5261SJens Axboe atomic_set(&bio->__bi_remaining, 1); 296f9c78b2bSJens Axboe } 297f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_reset); 298f9c78b2bSJens Axboe 29938f8baaeSChristoph Hellwig static struct bio *__bio_chain_endio(struct bio *bio) 300f9c78b2bSJens Axboe { 3014246a0b6SChristoph Hellwig struct bio *parent = bio->bi_private; 3024246a0b6SChristoph Hellwig 303af3e3a52SChristoph Hellwig if (!parent->bi_error) 3044246a0b6SChristoph Hellwig parent->bi_error = bio->bi_error; 305f9c78b2bSJens Axboe bio_put(bio); 30638f8baaeSChristoph Hellwig return parent; 30738f8baaeSChristoph Hellwig } 30838f8baaeSChristoph Hellwig 30938f8baaeSChristoph Hellwig static void bio_chain_endio(struct bio *bio) 31038f8baaeSChristoph Hellwig { 31138f8baaeSChristoph Hellwig bio_endio(__bio_chain_endio(bio)); 312f9c78b2bSJens Axboe } 313f9c78b2bSJens Axboe 314f9c78b2bSJens Axboe /** 315f9c78b2bSJens Axboe * bio_chain - chain bio completions 316f9c78b2bSJens Axboe * @bio: the target bio 317f9c78b2bSJens Axboe * @parent: the @bio's parent bio 318f9c78b2bSJens Axboe * 319f9c78b2bSJens Axboe * The caller won't have a bi_end_io called when @bio completes - instead, 320f9c78b2bSJens Axboe * @parent's bi_end_io won't be called until both @parent and @bio have 321f9c78b2bSJens Axboe * completed; the chained bio will also be freed when it completes. 322f9c78b2bSJens Axboe * 323f9c78b2bSJens Axboe * The caller must not set bi_private or bi_end_io in @bio. 324f9c78b2bSJens Axboe */ 325f9c78b2bSJens Axboe void bio_chain(struct bio *bio, struct bio *parent) 326f9c78b2bSJens Axboe { 327f9c78b2bSJens Axboe BUG_ON(bio->bi_private || bio->bi_end_io); 328f9c78b2bSJens Axboe 329f9c78b2bSJens Axboe bio->bi_private = parent; 330f9c78b2bSJens Axboe bio->bi_end_io = bio_chain_endio; 331c4cf5261SJens Axboe bio_inc_remaining(parent); 332f9c78b2bSJens Axboe } 333f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_chain); 334f9c78b2bSJens Axboe 335f9c78b2bSJens Axboe static void bio_alloc_rescue(struct work_struct *work) 336f9c78b2bSJens Axboe { 337f9c78b2bSJens Axboe struct bio_set *bs = container_of(work, struct bio_set, rescue_work); 338f9c78b2bSJens Axboe struct bio *bio; 339f9c78b2bSJens Axboe 340f9c78b2bSJens Axboe while (1) { 341f9c78b2bSJens Axboe spin_lock(&bs->rescue_lock); 342f9c78b2bSJens Axboe bio = bio_list_pop(&bs->rescue_list); 343f9c78b2bSJens Axboe spin_unlock(&bs->rescue_lock); 344f9c78b2bSJens Axboe 345f9c78b2bSJens Axboe if (!bio) 346f9c78b2bSJens Axboe break; 347f9c78b2bSJens Axboe 348f9c78b2bSJens Axboe generic_make_request(bio); 349f9c78b2bSJens Axboe } 350f9c78b2bSJens Axboe } 351f9c78b2bSJens Axboe 352f9c78b2bSJens Axboe static void punt_bios_to_rescuer(struct bio_set *bs) 353f9c78b2bSJens Axboe { 354f9c78b2bSJens Axboe struct bio_list punt, nopunt; 355f9c78b2bSJens Axboe struct bio *bio; 356f9c78b2bSJens Axboe 357f9c78b2bSJens Axboe /* 358f9c78b2bSJens Axboe * In order to guarantee forward progress we must punt only bios that 359f9c78b2bSJens Axboe * were allocated from this bio_set; otherwise, if there was a bio on 360f9c78b2bSJens Axboe * there for a stacking driver higher up in the stack, processing it 361f9c78b2bSJens Axboe * could require allocating bios from this bio_set, and doing that from 362f9c78b2bSJens Axboe * our own rescuer would be bad. 363f9c78b2bSJens Axboe * 364f9c78b2bSJens Axboe * Since bio lists are singly linked, pop them all instead of trying to 365f9c78b2bSJens Axboe * remove from the middle of the list: 366f9c78b2bSJens Axboe */ 367f9c78b2bSJens Axboe 368f9c78b2bSJens Axboe bio_list_init(&punt); 369f9c78b2bSJens Axboe bio_list_init(&nopunt); 370f9c78b2bSJens Axboe 371f9c78b2bSJens Axboe while ((bio = bio_list_pop(current->bio_list))) 372f9c78b2bSJens Axboe bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio); 373f9c78b2bSJens Axboe 374f9c78b2bSJens Axboe *current->bio_list = nopunt; 375f9c78b2bSJens Axboe 376f9c78b2bSJens Axboe spin_lock(&bs->rescue_lock); 377f9c78b2bSJens Axboe bio_list_merge(&bs->rescue_list, &punt); 378f9c78b2bSJens Axboe spin_unlock(&bs->rescue_lock); 379f9c78b2bSJens Axboe 380f9c78b2bSJens Axboe queue_work(bs->rescue_workqueue, &bs->rescue_work); 381f9c78b2bSJens Axboe } 382f9c78b2bSJens Axboe 383f9c78b2bSJens Axboe /** 384f9c78b2bSJens Axboe * bio_alloc_bioset - allocate a bio for I/O 385f9c78b2bSJens Axboe * @gfp_mask: the GFP_ mask given to the slab allocator 386f9c78b2bSJens Axboe * @nr_iovecs: number of iovecs to pre-allocate 387f9c78b2bSJens Axboe * @bs: the bio_set to allocate from. 388f9c78b2bSJens Axboe * 389f9c78b2bSJens Axboe * Description: 390f9c78b2bSJens Axboe * If @bs is NULL, uses kmalloc() to allocate the bio; else the allocation is 391f9c78b2bSJens Axboe * backed by the @bs's mempool. 392f9c78b2bSJens Axboe * 393d0164adcSMel Gorman * When @bs is not NULL, if %__GFP_DIRECT_RECLAIM is set then bio_alloc will 394d0164adcSMel Gorman * always be able to allocate a bio. This is due to the mempool guarantees. 395d0164adcSMel Gorman * To make this work, callers must never allocate more than 1 bio at a time 396d0164adcSMel Gorman * from this pool. Callers that need to allocate more than 1 bio must always 397d0164adcSMel Gorman * submit the previously allocated bio for IO before attempting to allocate 398d0164adcSMel Gorman * a new one. Failure to do so can cause deadlocks under memory pressure. 399f9c78b2bSJens Axboe * 400f9c78b2bSJens Axboe * Note that when running under generic_make_request() (i.e. any block 401f9c78b2bSJens Axboe * driver), bios are not submitted until after you return - see the code in 402f9c78b2bSJens Axboe * generic_make_request() that converts recursion into iteration, to prevent 403f9c78b2bSJens Axboe * stack overflows. 404f9c78b2bSJens Axboe * 405f9c78b2bSJens Axboe * This would normally mean allocating multiple bios under 406f9c78b2bSJens Axboe * generic_make_request() would be susceptible to deadlocks, but we have 407f9c78b2bSJens Axboe * deadlock avoidance code that resubmits any blocked bios from a rescuer 408f9c78b2bSJens Axboe * thread. 409f9c78b2bSJens Axboe * 410f9c78b2bSJens Axboe * However, we do not guarantee forward progress for allocations from other 411f9c78b2bSJens Axboe * mempools. Doing multiple allocations from the same mempool under 412f9c78b2bSJens Axboe * generic_make_request() should be avoided - instead, use bio_set's front_pad 413f9c78b2bSJens Axboe * for per bio allocations. 414f9c78b2bSJens Axboe * 415f9c78b2bSJens Axboe * RETURNS: 416f9c78b2bSJens Axboe * Pointer to new bio on success, NULL on failure. 417f9c78b2bSJens Axboe */ 418f9c78b2bSJens Axboe struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) 419f9c78b2bSJens Axboe { 420f9c78b2bSJens Axboe gfp_t saved_gfp = gfp_mask; 421f9c78b2bSJens Axboe unsigned front_pad; 422f9c78b2bSJens Axboe unsigned inline_vecs; 423f9c78b2bSJens Axboe unsigned long idx = BIO_POOL_NONE; 424f9c78b2bSJens Axboe struct bio_vec *bvl = NULL; 425f9c78b2bSJens Axboe struct bio *bio; 426f9c78b2bSJens Axboe void *p; 427f9c78b2bSJens Axboe 428f9c78b2bSJens Axboe if (!bs) { 429f9c78b2bSJens Axboe if (nr_iovecs > UIO_MAXIOV) 430f9c78b2bSJens Axboe return NULL; 431f9c78b2bSJens Axboe 432f9c78b2bSJens Axboe p = kmalloc(sizeof(struct bio) + 433f9c78b2bSJens Axboe nr_iovecs * sizeof(struct bio_vec), 434f9c78b2bSJens Axboe gfp_mask); 435f9c78b2bSJens Axboe front_pad = 0; 436f9c78b2bSJens Axboe inline_vecs = nr_iovecs; 437f9c78b2bSJens Axboe } else { 438d8f429e1SJunichi Nomura /* should not use nobvec bioset for nr_iovecs > 0 */ 439d8f429e1SJunichi Nomura if (WARN_ON_ONCE(!bs->bvec_pool && nr_iovecs > 0)) 440d8f429e1SJunichi Nomura return NULL; 441f9c78b2bSJens Axboe /* 442f9c78b2bSJens Axboe * generic_make_request() converts recursion to iteration; this 443f9c78b2bSJens Axboe * means if we're running beneath it, any bios we allocate and 444f9c78b2bSJens Axboe * submit will not be submitted (and thus freed) until after we 445f9c78b2bSJens Axboe * return. 446f9c78b2bSJens Axboe * 447f9c78b2bSJens Axboe * This exposes us to a potential deadlock if we allocate 448f9c78b2bSJens Axboe * multiple bios from the same bio_set() while running 449f9c78b2bSJens Axboe * underneath generic_make_request(). If we were to allocate 450f9c78b2bSJens Axboe * multiple bios (say a stacking block driver that was splitting 451f9c78b2bSJens Axboe * bios), we would deadlock if we exhausted the mempool's 452f9c78b2bSJens Axboe * reserve. 453f9c78b2bSJens Axboe * 454f9c78b2bSJens Axboe * We solve this, and guarantee forward progress, with a rescuer 455f9c78b2bSJens Axboe * workqueue per bio_set. If we go to allocate and there are 456f9c78b2bSJens Axboe * bios on current->bio_list, we first try the allocation 457d0164adcSMel Gorman * without __GFP_DIRECT_RECLAIM; if that fails, we punt those 458d0164adcSMel Gorman * bios we would be blocking to the rescuer workqueue before 459d0164adcSMel Gorman * we retry with the original gfp_flags. 460f9c78b2bSJens Axboe */ 461f9c78b2bSJens Axboe 462f9c78b2bSJens Axboe if (current->bio_list && !bio_list_empty(current->bio_list)) 463d0164adcSMel Gorman gfp_mask &= ~__GFP_DIRECT_RECLAIM; 464f9c78b2bSJens Axboe 465f9c78b2bSJens Axboe p = mempool_alloc(bs->bio_pool, gfp_mask); 466f9c78b2bSJens Axboe if (!p && gfp_mask != saved_gfp) { 467f9c78b2bSJens Axboe punt_bios_to_rescuer(bs); 468f9c78b2bSJens Axboe gfp_mask = saved_gfp; 469f9c78b2bSJens Axboe p = mempool_alloc(bs->bio_pool, gfp_mask); 470f9c78b2bSJens Axboe } 471f9c78b2bSJens Axboe 472f9c78b2bSJens Axboe front_pad = bs->front_pad; 473f9c78b2bSJens Axboe inline_vecs = BIO_INLINE_VECS; 474f9c78b2bSJens Axboe } 475f9c78b2bSJens Axboe 476f9c78b2bSJens Axboe if (unlikely(!p)) 477f9c78b2bSJens Axboe return NULL; 478f9c78b2bSJens Axboe 479f9c78b2bSJens Axboe bio = p + front_pad; 480f9c78b2bSJens Axboe bio_init(bio); 481f9c78b2bSJens Axboe 482f9c78b2bSJens Axboe if (nr_iovecs > inline_vecs) { 483f9c78b2bSJens Axboe bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool); 484f9c78b2bSJens Axboe if (!bvl && gfp_mask != saved_gfp) { 485f9c78b2bSJens Axboe punt_bios_to_rescuer(bs); 486f9c78b2bSJens Axboe gfp_mask = saved_gfp; 487f9c78b2bSJens Axboe bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool); 488f9c78b2bSJens Axboe } 489f9c78b2bSJens Axboe 490f9c78b2bSJens Axboe if (unlikely(!bvl)) 491f9c78b2bSJens Axboe goto err_free; 492f9c78b2bSJens Axboe 493b7c44ed9SJens Axboe bio_set_flag(bio, BIO_OWNS_VEC); 494f9c78b2bSJens Axboe } else if (nr_iovecs) { 495f9c78b2bSJens Axboe bvl = bio->bi_inline_vecs; 496f9c78b2bSJens Axboe } 497f9c78b2bSJens Axboe 498f9c78b2bSJens Axboe bio->bi_pool = bs; 499f9c78b2bSJens Axboe bio->bi_flags |= idx << BIO_POOL_OFFSET; 500f9c78b2bSJens Axboe bio->bi_max_vecs = nr_iovecs; 501f9c78b2bSJens Axboe bio->bi_io_vec = bvl; 502f9c78b2bSJens Axboe return bio; 503f9c78b2bSJens Axboe 504f9c78b2bSJens Axboe err_free: 505f9c78b2bSJens Axboe mempool_free(p, bs->bio_pool); 506f9c78b2bSJens Axboe return NULL; 507f9c78b2bSJens Axboe } 508f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_alloc_bioset); 509f9c78b2bSJens Axboe 510f9c78b2bSJens Axboe void zero_fill_bio(struct bio *bio) 511f9c78b2bSJens Axboe { 512f9c78b2bSJens Axboe unsigned long flags; 513f9c78b2bSJens Axboe struct bio_vec bv; 514f9c78b2bSJens Axboe struct bvec_iter iter; 515f9c78b2bSJens Axboe 516f9c78b2bSJens Axboe bio_for_each_segment(bv, bio, iter) { 517f9c78b2bSJens Axboe char *data = bvec_kmap_irq(&bv, &flags); 518f9c78b2bSJens Axboe memset(data, 0, bv.bv_len); 519f9c78b2bSJens Axboe flush_dcache_page(bv.bv_page); 520f9c78b2bSJens Axboe bvec_kunmap_irq(data, &flags); 521f9c78b2bSJens Axboe } 522f9c78b2bSJens Axboe } 523f9c78b2bSJens Axboe EXPORT_SYMBOL(zero_fill_bio); 524f9c78b2bSJens Axboe 525f9c78b2bSJens Axboe /** 526f9c78b2bSJens Axboe * bio_put - release a reference to a bio 527f9c78b2bSJens Axboe * @bio: bio to release reference to 528f9c78b2bSJens Axboe * 529f9c78b2bSJens Axboe * Description: 530f9c78b2bSJens Axboe * Put a reference to a &struct bio, either one you have gotten with 531f9c78b2bSJens Axboe * bio_alloc, bio_get or bio_clone. The last put of a bio will free it. 532f9c78b2bSJens Axboe **/ 533f9c78b2bSJens Axboe void bio_put(struct bio *bio) 534f9c78b2bSJens Axboe { 535dac56212SJens Axboe if (!bio_flagged(bio, BIO_REFFED)) 536dac56212SJens Axboe bio_free(bio); 537dac56212SJens Axboe else { 538dac56212SJens Axboe BIO_BUG_ON(!atomic_read(&bio->__bi_cnt)); 539f9c78b2bSJens Axboe 540f9c78b2bSJens Axboe /* 541f9c78b2bSJens Axboe * last put frees it 542f9c78b2bSJens Axboe */ 543dac56212SJens Axboe if (atomic_dec_and_test(&bio->__bi_cnt)) 544f9c78b2bSJens Axboe bio_free(bio); 545f9c78b2bSJens Axboe } 546dac56212SJens Axboe } 547f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_put); 548f9c78b2bSJens Axboe 549f9c78b2bSJens Axboe inline int bio_phys_segments(struct request_queue *q, struct bio *bio) 550f9c78b2bSJens Axboe { 551f9c78b2bSJens Axboe if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) 552f9c78b2bSJens Axboe blk_recount_segments(q, bio); 553f9c78b2bSJens Axboe 554f9c78b2bSJens Axboe return bio->bi_phys_segments; 555f9c78b2bSJens Axboe } 556f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_phys_segments); 557f9c78b2bSJens Axboe 558f9c78b2bSJens Axboe /** 559f9c78b2bSJens Axboe * __bio_clone_fast - clone a bio that shares the original bio's biovec 560f9c78b2bSJens Axboe * @bio: destination bio 561f9c78b2bSJens Axboe * @bio_src: bio to clone 562f9c78b2bSJens Axboe * 563f9c78b2bSJens Axboe * Clone a &bio. Caller will own the returned bio, but not 564f9c78b2bSJens Axboe * the actual data it points to. Reference count of returned 565f9c78b2bSJens Axboe * bio will be one. 566f9c78b2bSJens Axboe * 567f9c78b2bSJens Axboe * Caller must ensure that @bio_src is not freed before @bio. 568f9c78b2bSJens Axboe */ 569f9c78b2bSJens Axboe void __bio_clone_fast(struct bio *bio, struct bio *bio_src) 570f9c78b2bSJens Axboe { 571f9c78b2bSJens Axboe BUG_ON(bio->bi_pool && BIO_POOL_IDX(bio) != BIO_POOL_NONE); 572f9c78b2bSJens Axboe 573f9c78b2bSJens Axboe /* 574f9c78b2bSJens Axboe * most users will be overriding ->bi_bdev with a new target, 575f9c78b2bSJens Axboe * so we don't set nor calculate new physical/hw segment counts here 576f9c78b2bSJens Axboe */ 577f9c78b2bSJens Axboe bio->bi_bdev = bio_src->bi_bdev; 578b7c44ed9SJens Axboe bio_set_flag(bio, BIO_CLONED); 579f9c78b2bSJens Axboe bio->bi_rw = bio_src->bi_rw; 580f9c78b2bSJens Axboe bio->bi_iter = bio_src->bi_iter; 581f9c78b2bSJens Axboe bio->bi_io_vec = bio_src->bi_io_vec; 582f9c78b2bSJens Axboe } 583f9c78b2bSJens Axboe EXPORT_SYMBOL(__bio_clone_fast); 584f9c78b2bSJens Axboe 585f9c78b2bSJens Axboe /** 586f9c78b2bSJens Axboe * bio_clone_fast - clone a bio that shares the original bio's biovec 587f9c78b2bSJens Axboe * @bio: bio to clone 588f9c78b2bSJens Axboe * @gfp_mask: allocation priority 589f9c78b2bSJens Axboe * @bs: bio_set to allocate from 590f9c78b2bSJens Axboe * 591f9c78b2bSJens Axboe * Like __bio_clone_fast, only also allocates the returned bio 592f9c78b2bSJens Axboe */ 593f9c78b2bSJens Axboe struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) 594f9c78b2bSJens Axboe { 595f9c78b2bSJens Axboe struct bio *b; 596f9c78b2bSJens Axboe 597f9c78b2bSJens Axboe b = bio_alloc_bioset(gfp_mask, 0, bs); 598f9c78b2bSJens Axboe if (!b) 599f9c78b2bSJens Axboe return NULL; 600f9c78b2bSJens Axboe 601f9c78b2bSJens Axboe __bio_clone_fast(b, bio); 602f9c78b2bSJens Axboe 603f9c78b2bSJens Axboe if (bio_integrity(bio)) { 604f9c78b2bSJens Axboe int ret; 605f9c78b2bSJens Axboe 606f9c78b2bSJens Axboe ret = bio_integrity_clone(b, bio, gfp_mask); 607f9c78b2bSJens Axboe 608f9c78b2bSJens Axboe if (ret < 0) { 609f9c78b2bSJens Axboe bio_put(b); 610f9c78b2bSJens Axboe return NULL; 611f9c78b2bSJens Axboe } 612f9c78b2bSJens Axboe } 613f9c78b2bSJens Axboe 614f9c78b2bSJens Axboe return b; 615f9c78b2bSJens Axboe } 616f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_clone_fast); 617f9c78b2bSJens Axboe 618f9c78b2bSJens Axboe /** 619f9c78b2bSJens Axboe * bio_clone_bioset - clone a bio 620f9c78b2bSJens Axboe * @bio_src: bio to clone 621f9c78b2bSJens Axboe * @gfp_mask: allocation priority 622f9c78b2bSJens Axboe * @bs: bio_set to allocate from 623f9c78b2bSJens Axboe * 624f9c78b2bSJens Axboe * Clone bio. Caller will own the returned bio, but not the actual data it 625f9c78b2bSJens Axboe * points to. Reference count of returned bio will be one. 626f9c78b2bSJens Axboe */ 627f9c78b2bSJens Axboe struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask, 628f9c78b2bSJens Axboe struct bio_set *bs) 629f9c78b2bSJens Axboe { 630f9c78b2bSJens Axboe struct bvec_iter iter; 631f9c78b2bSJens Axboe struct bio_vec bv; 632f9c78b2bSJens Axboe struct bio *bio; 633f9c78b2bSJens Axboe 634f9c78b2bSJens Axboe /* 635f9c78b2bSJens Axboe * Pre immutable biovecs, __bio_clone() used to just do a memcpy from 636f9c78b2bSJens Axboe * bio_src->bi_io_vec to bio->bi_io_vec. 637f9c78b2bSJens Axboe * 638f9c78b2bSJens Axboe * We can't do that anymore, because: 639f9c78b2bSJens Axboe * 640f9c78b2bSJens Axboe * - The point of cloning the biovec is to produce a bio with a biovec 641f9c78b2bSJens Axboe * the caller can modify: bi_idx and bi_bvec_done should be 0. 642f9c78b2bSJens Axboe * 643f9c78b2bSJens Axboe * - The original bio could've had more than BIO_MAX_PAGES biovecs; if 644f9c78b2bSJens Axboe * we tried to clone the whole thing bio_alloc_bioset() would fail. 645f9c78b2bSJens Axboe * But the clone should succeed as long as the number of biovecs we 646f9c78b2bSJens Axboe * actually need to allocate is fewer than BIO_MAX_PAGES. 647f9c78b2bSJens Axboe * 648f9c78b2bSJens Axboe * - Lastly, bi_vcnt should not be looked at or relied upon by code 649f9c78b2bSJens Axboe * that does not own the bio - reason being drivers don't use it for 650f9c78b2bSJens Axboe * iterating over the biovec anymore, so expecting it to be kept up 651f9c78b2bSJens Axboe * to date (i.e. for clones that share the parent biovec) is just 652f9c78b2bSJens Axboe * asking for trouble and would force extra work on 653f9c78b2bSJens Axboe * __bio_clone_fast() anyways. 654f9c78b2bSJens Axboe */ 655f9c78b2bSJens Axboe 656f9c78b2bSJens Axboe bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs); 657f9c78b2bSJens Axboe if (!bio) 658f9c78b2bSJens Axboe return NULL; 659f9c78b2bSJens Axboe 660f9c78b2bSJens Axboe bio->bi_bdev = bio_src->bi_bdev; 661f9c78b2bSJens Axboe bio->bi_rw = bio_src->bi_rw; 662f9c78b2bSJens Axboe bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector; 663f9c78b2bSJens Axboe bio->bi_iter.bi_size = bio_src->bi_iter.bi_size; 664f9c78b2bSJens Axboe 665f9c78b2bSJens Axboe if (bio->bi_rw & REQ_DISCARD) 666f9c78b2bSJens Axboe goto integrity_clone; 667f9c78b2bSJens Axboe 668f9c78b2bSJens Axboe if (bio->bi_rw & REQ_WRITE_SAME) { 669f9c78b2bSJens Axboe bio->bi_io_vec[bio->bi_vcnt++] = bio_src->bi_io_vec[0]; 670f9c78b2bSJens Axboe goto integrity_clone; 671f9c78b2bSJens Axboe } 672f9c78b2bSJens Axboe 673f9c78b2bSJens Axboe bio_for_each_segment(bv, bio_src, iter) 674f9c78b2bSJens Axboe bio->bi_io_vec[bio->bi_vcnt++] = bv; 675f9c78b2bSJens Axboe 676f9c78b2bSJens Axboe integrity_clone: 677f9c78b2bSJens Axboe if (bio_integrity(bio_src)) { 678f9c78b2bSJens Axboe int ret; 679f9c78b2bSJens Axboe 680f9c78b2bSJens Axboe ret = bio_integrity_clone(bio, bio_src, gfp_mask); 681f9c78b2bSJens Axboe if (ret < 0) { 682f9c78b2bSJens Axboe bio_put(bio); 683f9c78b2bSJens Axboe return NULL; 684f9c78b2bSJens Axboe } 685f9c78b2bSJens Axboe } 686f9c78b2bSJens Axboe 687f9c78b2bSJens Axboe return bio; 688f9c78b2bSJens Axboe } 689f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_clone_bioset); 690f9c78b2bSJens Axboe 691f9c78b2bSJens Axboe /** 692c66a14d0SKent Overstreet * bio_add_pc_page - attempt to add page to bio 693c66a14d0SKent Overstreet * @q: the target queue 694c66a14d0SKent Overstreet * @bio: destination bio 695c66a14d0SKent Overstreet * @page: page to add 696c66a14d0SKent Overstreet * @len: vec entry length 697c66a14d0SKent Overstreet * @offset: vec entry offset 698f9c78b2bSJens Axboe * 699c66a14d0SKent Overstreet * Attempt to add a page to the bio_vec maplist. This can fail for a 700c66a14d0SKent Overstreet * number of reasons, such as the bio being full or target block device 701c66a14d0SKent Overstreet * limitations. The target block device must allow bio's up to PAGE_SIZE, 702c66a14d0SKent Overstreet * so it is always possible to add a single page to an empty bio. 703c66a14d0SKent Overstreet * 704c66a14d0SKent Overstreet * This should only be used by REQ_PC bios. 705f9c78b2bSJens Axboe */ 706c66a14d0SKent Overstreet int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page 707c66a14d0SKent Overstreet *page, unsigned int len, unsigned int offset) 708f9c78b2bSJens Axboe { 709f9c78b2bSJens Axboe int retried_segments = 0; 710f9c78b2bSJens Axboe struct bio_vec *bvec; 711f9c78b2bSJens Axboe 712f9c78b2bSJens Axboe /* 713f9c78b2bSJens Axboe * cloned bio must not modify vec list 714f9c78b2bSJens Axboe */ 715f9c78b2bSJens Axboe if (unlikely(bio_flagged(bio, BIO_CLONED))) 716f9c78b2bSJens Axboe return 0; 717f9c78b2bSJens Axboe 718c66a14d0SKent Overstreet if (((bio->bi_iter.bi_size + len) >> 9) > queue_max_hw_sectors(q)) 719f9c78b2bSJens Axboe return 0; 720f9c78b2bSJens Axboe 721f9c78b2bSJens Axboe /* 722f9c78b2bSJens Axboe * For filesystems with a blocksize smaller than the pagesize 723f9c78b2bSJens Axboe * we will often be called with the same page as last time and 724f9c78b2bSJens Axboe * a consecutive offset. Optimize this special case. 725f9c78b2bSJens Axboe */ 726f9c78b2bSJens Axboe if (bio->bi_vcnt > 0) { 727f9c78b2bSJens Axboe struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1]; 728f9c78b2bSJens Axboe 729f9c78b2bSJens Axboe if (page == prev->bv_page && 730f9c78b2bSJens Axboe offset == prev->bv_offset + prev->bv_len) { 731f9c78b2bSJens Axboe prev->bv_len += len; 732fcbf6a08SMaurizio Lombardi bio->bi_iter.bi_size += len; 733f9c78b2bSJens Axboe goto done; 734f9c78b2bSJens Axboe } 73566cb45aaSJens Axboe 73666cb45aaSJens Axboe /* 73766cb45aaSJens Axboe * If the queue doesn't support SG gaps and adding this 73866cb45aaSJens Axboe * offset would create a gap, disallow it. 73966cb45aaSJens Axboe */ 74003100aadSKeith Busch if (bvec_gap_to_prev(q, prev, offset)) 74166cb45aaSJens Axboe return 0; 742f9c78b2bSJens Axboe } 743f9c78b2bSJens Axboe 744f9c78b2bSJens Axboe if (bio->bi_vcnt >= bio->bi_max_vecs) 745f9c78b2bSJens Axboe return 0; 746f9c78b2bSJens Axboe 747f9c78b2bSJens Axboe /* 748f9c78b2bSJens Axboe * setup the new entry, we might clear it again later if we 749f9c78b2bSJens Axboe * cannot add the page 750f9c78b2bSJens Axboe */ 751f9c78b2bSJens Axboe bvec = &bio->bi_io_vec[bio->bi_vcnt]; 752f9c78b2bSJens Axboe bvec->bv_page = page; 753f9c78b2bSJens Axboe bvec->bv_len = len; 754f9c78b2bSJens Axboe bvec->bv_offset = offset; 755fcbf6a08SMaurizio Lombardi bio->bi_vcnt++; 756fcbf6a08SMaurizio Lombardi bio->bi_phys_segments++; 757fcbf6a08SMaurizio Lombardi bio->bi_iter.bi_size += len; 758fcbf6a08SMaurizio Lombardi 759fcbf6a08SMaurizio Lombardi /* 760fcbf6a08SMaurizio Lombardi * Perform a recount if the number of segments is greater 761fcbf6a08SMaurizio Lombardi * than queue_max_segments(q). 762fcbf6a08SMaurizio Lombardi */ 763fcbf6a08SMaurizio Lombardi 764fcbf6a08SMaurizio Lombardi while (bio->bi_phys_segments > queue_max_segments(q)) { 765fcbf6a08SMaurizio Lombardi 766fcbf6a08SMaurizio Lombardi if (retried_segments) 767fcbf6a08SMaurizio Lombardi goto failed; 768fcbf6a08SMaurizio Lombardi 769fcbf6a08SMaurizio Lombardi retried_segments = 1; 770fcbf6a08SMaurizio Lombardi blk_recount_segments(q, bio); 771fcbf6a08SMaurizio Lombardi } 772f9c78b2bSJens Axboe 773f9c78b2bSJens Axboe /* If we may be able to merge these biovecs, force a recount */ 774fcbf6a08SMaurizio Lombardi if (bio->bi_vcnt > 1 && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec))) 775b7c44ed9SJens Axboe bio_clear_flag(bio, BIO_SEG_VALID); 776f9c78b2bSJens Axboe 777f9c78b2bSJens Axboe done: 778f9c78b2bSJens Axboe return len; 779fcbf6a08SMaurizio Lombardi 780fcbf6a08SMaurizio Lombardi failed: 781fcbf6a08SMaurizio Lombardi bvec->bv_page = NULL; 782fcbf6a08SMaurizio Lombardi bvec->bv_len = 0; 783fcbf6a08SMaurizio Lombardi bvec->bv_offset = 0; 784fcbf6a08SMaurizio Lombardi bio->bi_vcnt--; 785fcbf6a08SMaurizio Lombardi bio->bi_iter.bi_size -= len; 786fcbf6a08SMaurizio Lombardi blk_recount_segments(q, bio); 787fcbf6a08SMaurizio Lombardi return 0; 788f9c78b2bSJens Axboe } 789f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_add_pc_page); 790f9c78b2bSJens Axboe 791f9c78b2bSJens Axboe /** 792f9c78b2bSJens Axboe * bio_add_page - attempt to add page to bio 793f9c78b2bSJens Axboe * @bio: destination bio 794f9c78b2bSJens Axboe * @page: page to add 795f9c78b2bSJens Axboe * @len: vec entry length 796f9c78b2bSJens Axboe * @offset: vec entry offset 797f9c78b2bSJens Axboe * 798c66a14d0SKent Overstreet * Attempt to add a page to the bio_vec maplist. This will only fail 799c66a14d0SKent Overstreet * if either bio->bi_vcnt == bio->bi_max_vecs or it's a cloned bio. 800f9c78b2bSJens Axboe */ 801c66a14d0SKent Overstreet int bio_add_page(struct bio *bio, struct page *page, 802c66a14d0SKent Overstreet unsigned int len, unsigned int offset) 803f9c78b2bSJens Axboe { 804c66a14d0SKent Overstreet struct bio_vec *bv; 805762380adSJens Axboe 806c66a14d0SKent Overstreet /* 807c66a14d0SKent Overstreet * cloned bio must not modify vec list 808c66a14d0SKent Overstreet */ 809c66a14d0SKent Overstreet if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED))) 810c66a14d0SKent Overstreet return 0; 81158a4915aSJens Axboe 812c66a14d0SKent Overstreet /* 813c66a14d0SKent Overstreet * For filesystems with a blocksize smaller than the pagesize 814c66a14d0SKent Overstreet * we will often be called with the same page as last time and 815c66a14d0SKent Overstreet * a consecutive offset. Optimize this special case. 816c66a14d0SKent Overstreet */ 817c66a14d0SKent Overstreet if (bio->bi_vcnt > 0) { 818c66a14d0SKent Overstreet bv = &bio->bi_io_vec[bio->bi_vcnt - 1]; 819c66a14d0SKent Overstreet 820c66a14d0SKent Overstreet if (page == bv->bv_page && 821c66a14d0SKent Overstreet offset == bv->bv_offset + bv->bv_len) { 822c66a14d0SKent Overstreet bv->bv_len += len; 823c66a14d0SKent Overstreet goto done; 824c66a14d0SKent Overstreet } 825c66a14d0SKent Overstreet } 826c66a14d0SKent Overstreet 827c66a14d0SKent Overstreet if (bio->bi_vcnt >= bio->bi_max_vecs) 828c66a14d0SKent Overstreet return 0; 829c66a14d0SKent Overstreet 830c66a14d0SKent Overstreet bv = &bio->bi_io_vec[bio->bi_vcnt]; 831c66a14d0SKent Overstreet bv->bv_page = page; 832c66a14d0SKent Overstreet bv->bv_len = len; 833c66a14d0SKent Overstreet bv->bv_offset = offset; 834c66a14d0SKent Overstreet 835c66a14d0SKent Overstreet bio->bi_vcnt++; 836c66a14d0SKent Overstreet done: 837c66a14d0SKent Overstreet bio->bi_iter.bi_size += len; 838c66a14d0SKent Overstreet return len; 839f9c78b2bSJens Axboe } 840f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_add_page); 841f9c78b2bSJens Axboe 842f9c78b2bSJens Axboe struct submit_bio_ret { 843f9c78b2bSJens Axboe struct completion event; 844f9c78b2bSJens Axboe int error; 845f9c78b2bSJens Axboe }; 846f9c78b2bSJens Axboe 8474246a0b6SChristoph Hellwig static void submit_bio_wait_endio(struct bio *bio) 848f9c78b2bSJens Axboe { 849f9c78b2bSJens Axboe struct submit_bio_ret *ret = bio->bi_private; 850f9c78b2bSJens Axboe 8514246a0b6SChristoph Hellwig ret->error = bio->bi_error; 852f9c78b2bSJens Axboe complete(&ret->event); 853f9c78b2bSJens Axboe } 854f9c78b2bSJens Axboe 855f9c78b2bSJens Axboe /** 856f9c78b2bSJens Axboe * submit_bio_wait - submit a bio, and wait until it completes 857f9c78b2bSJens Axboe * @bio: The &struct bio which describes the I/O 858f9c78b2bSJens Axboe * 859f9c78b2bSJens Axboe * Simple wrapper around submit_bio(). Returns 0 on success, or the error from 860f9c78b2bSJens Axboe * bio_endio() on failure. 861f9c78b2bSJens Axboe */ 8624e49ea4aSMike Christie int submit_bio_wait(struct bio *bio) 863f9c78b2bSJens Axboe { 864f9c78b2bSJens Axboe struct submit_bio_ret ret; 865f9c78b2bSJens Axboe 866f9c78b2bSJens Axboe init_completion(&ret.event); 867f9c78b2bSJens Axboe bio->bi_private = &ret; 868f9c78b2bSJens Axboe bio->bi_end_io = submit_bio_wait_endio; 8694e49ea4aSMike Christie bio->bi_rw |= REQ_SYNC; 8704e49ea4aSMike Christie submit_bio(bio); 871d57d6115SStephane Gasparini wait_for_completion_io(&ret.event); 872f9c78b2bSJens Axboe 873f9c78b2bSJens Axboe return ret.error; 874f9c78b2bSJens Axboe } 875f9c78b2bSJens Axboe EXPORT_SYMBOL(submit_bio_wait); 876f9c78b2bSJens Axboe 877f9c78b2bSJens Axboe /** 878f9c78b2bSJens Axboe * bio_advance - increment/complete a bio by some number of bytes 879f9c78b2bSJens Axboe * @bio: bio to advance 880f9c78b2bSJens Axboe * @bytes: number of bytes to complete 881f9c78b2bSJens Axboe * 882f9c78b2bSJens Axboe * This updates bi_sector, bi_size and bi_idx; if the number of bytes to 883f9c78b2bSJens Axboe * complete doesn't align with a bvec boundary, then bv_len and bv_offset will 884f9c78b2bSJens Axboe * be updated on the last bvec as well. 885f9c78b2bSJens Axboe * 886f9c78b2bSJens Axboe * @bio will then represent the remaining, uncompleted portion of the io. 887f9c78b2bSJens Axboe */ 888f9c78b2bSJens Axboe void bio_advance(struct bio *bio, unsigned bytes) 889f9c78b2bSJens Axboe { 890f9c78b2bSJens Axboe if (bio_integrity(bio)) 891f9c78b2bSJens Axboe bio_integrity_advance(bio, bytes); 892f9c78b2bSJens Axboe 893f9c78b2bSJens Axboe bio_advance_iter(bio, &bio->bi_iter, bytes); 894f9c78b2bSJens Axboe } 895f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_advance); 896f9c78b2bSJens Axboe 897f9c78b2bSJens Axboe /** 898f9c78b2bSJens Axboe * bio_alloc_pages - allocates a single page for each bvec in a bio 899f9c78b2bSJens Axboe * @bio: bio to allocate pages for 900f9c78b2bSJens Axboe * @gfp_mask: flags for allocation 901f9c78b2bSJens Axboe * 902f9c78b2bSJens Axboe * Allocates pages up to @bio->bi_vcnt. 903f9c78b2bSJens Axboe * 904f9c78b2bSJens Axboe * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are 905f9c78b2bSJens Axboe * freed. 906f9c78b2bSJens Axboe */ 907f9c78b2bSJens Axboe int bio_alloc_pages(struct bio *bio, gfp_t gfp_mask) 908f9c78b2bSJens Axboe { 909f9c78b2bSJens Axboe int i; 910f9c78b2bSJens Axboe struct bio_vec *bv; 911f9c78b2bSJens Axboe 912f9c78b2bSJens Axboe bio_for_each_segment_all(bv, bio, i) { 913f9c78b2bSJens Axboe bv->bv_page = alloc_page(gfp_mask); 914f9c78b2bSJens Axboe if (!bv->bv_page) { 915f9c78b2bSJens Axboe while (--bv >= bio->bi_io_vec) 916f9c78b2bSJens Axboe __free_page(bv->bv_page); 917f9c78b2bSJens Axboe return -ENOMEM; 918f9c78b2bSJens Axboe } 919f9c78b2bSJens Axboe } 920f9c78b2bSJens Axboe 921f9c78b2bSJens Axboe return 0; 922f9c78b2bSJens Axboe } 923f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_alloc_pages); 924f9c78b2bSJens Axboe 925f9c78b2bSJens Axboe /** 926f9c78b2bSJens Axboe * bio_copy_data - copy contents of data buffers from one chain of bios to 927f9c78b2bSJens Axboe * another 928f9c78b2bSJens Axboe * @src: source bio list 929f9c78b2bSJens Axboe * @dst: destination bio list 930f9c78b2bSJens Axboe * 931f9c78b2bSJens Axboe * If @src and @dst are single bios, bi_next must be NULL - otherwise, treats 932f9c78b2bSJens Axboe * @src and @dst as linked lists of bios. 933f9c78b2bSJens Axboe * 934f9c78b2bSJens Axboe * Stops when it reaches the end of either @src or @dst - that is, copies 935f9c78b2bSJens Axboe * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios). 936f9c78b2bSJens Axboe */ 937f9c78b2bSJens Axboe void bio_copy_data(struct bio *dst, struct bio *src) 938f9c78b2bSJens Axboe { 939f9c78b2bSJens Axboe struct bvec_iter src_iter, dst_iter; 940f9c78b2bSJens Axboe struct bio_vec src_bv, dst_bv; 941f9c78b2bSJens Axboe void *src_p, *dst_p; 942f9c78b2bSJens Axboe unsigned bytes; 943f9c78b2bSJens Axboe 944f9c78b2bSJens Axboe src_iter = src->bi_iter; 945f9c78b2bSJens Axboe dst_iter = dst->bi_iter; 946f9c78b2bSJens Axboe 947f9c78b2bSJens Axboe while (1) { 948f9c78b2bSJens Axboe if (!src_iter.bi_size) { 949f9c78b2bSJens Axboe src = src->bi_next; 950f9c78b2bSJens Axboe if (!src) 951f9c78b2bSJens Axboe break; 952f9c78b2bSJens Axboe 953f9c78b2bSJens Axboe src_iter = src->bi_iter; 954f9c78b2bSJens Axboe } 955f9c78b2bSJens Axboe 956f9c78b2bSJens Axboe if (!dst_iter.bi_size) { 957f9c78b2bSJens Axboe dst = dst->bi_next; 958f9c78b2bSJens Axboe if (!dst) 959f9c78b2bSJens Axboe break; 960f9c78b2bSJens Axboe 961f9c78b2bSJens Axboe dst_iter = dst->bi_iter; 962f9c78b2bSJens Axboe } 963f9c78b2bSJens Axboe 964f9c78b2bSJens Axboe src_bv = bio_iter_iovec(src, src_iter); 965f9c78b2bSJens Axboe dst_bv = bio_iter_iovec(dst, dst_iter); 966f9c78b2bSJens Axboe 967f9c78b2bSJens Axboe bytes = min(src_bv.bv_len, dst_bv.bv_len); 968f9c78b2bSJens Axboe 969f9c78b2bSJens Axboe src_p = kmap_atomic(src_bv.bv_page); 970f9c78b2bSJens Axboe dst_p = kmap_atomic(dst_bv.bv_page); 971f9c78b2bSJens Axboe 972f9c78b2bSJens Axboe memcpy(dst_p + dst_bv.bv_offset, 973f9c78b2bSJens Axboe src_p + src_bv.bv_offset, 974f9c78b2bSJens Axboe bytes); 975f9c78b2bSJens Axboe 976f9c78b2bSJens Axboe kunmap_atomic(dst_p); 977f9c78b2bSJens Axboe kunmap_atomic(src_p); 978f9c78b2bSJens Axboe 979f9c78b2bSJens Axboe bio_advance_iter(src, &src_iter, bytes); 980f9c78b2bSJens Axboe bio_advance_iter(dst, &dst_iter, bytes); 981f9c78b2bSJens Axboe } 982f9c78b2bSJens Axboe } 983f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_copy_data); 984f9c78b2bSJens Axboe 985f9c78b2bSJens Axboe struct bio_map_data { 986f9c78b2bSJens Axboe int is_our_pages; 98726e49cfcSKent Overstreet struct iov_iter iter; 98826e49cfcSKent Overstreet struct iovec iov[]; 989f9c78b2bSJens Axboe }; 990f9c78b2bSJens Axboe 991f9c78b2bSJens Axboe static struct bio_map_data *bio_alloc_map_data(unsigned int iov_count, 992f9c78b2bSJens Axboe gfp_t gfp_mask) 993f9c78b2bSJens Axboe { 994f9c78b2bSJens Axboe if (iov_count > UIO_MAXIOV) 995f9c78b2bSJens Axboe return NULL; 996f9c78b2bSJens Axboe 997f9c78b2bSJens Axboe return kmalloc(sizeof(struct bio_map_data) + 99826e49cfcSKent Overstreet sizeof(struct iovec) * iov_count, gfp_mask); 999f9c78b2bSJens Axboe } 1000f9c78b2bSJens Axboe 10019124d3feSDongsu Park /** 10029124d3feSDongsu Park * bio_copy_from_iter - copy all pages from iov_iter to bio 10039124d3feSDongsu Park * @bio: The &struct bio which describes the I/O as destination 10049124d3feSDongsu Park * @iter: iov_iter as source 10059124d3feSDongsu Park * 10069124d3feSDongsu Park * Copy all pages from iov_iter to bio. 10079124d3feSDongsu Park * Returns 0 on success, or error on failure. 10089124d3feSDongsu Park */ 10099124d3feSDongsu Park static int bio_copy_from_iter(struct bio *bio, struct iov_iter iter) 1010f9c78b2bSJens Axboe { 10119124d3feSDongsu Park int i; 1012f9c78b2bSJens Axboe struct bio_vec *bvec; 1013f9c78b2bSJens Axboe 1014f9c78b2bSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 10159124d3feSDongsu Park ssize_t ret; 1016f9c78b2bSJens Axboe 10179124d3feSDongsu Park ret = copy_page_from_iter(bvec->bv_page, 10189124d3feSDongsu Park bvec->bv_offset, 10199124d3feSDongsu Park bvec->bv_len, 10209124d3feSDongsu Park &iter); 1021f9c78b2bSJens Axboe 10229124d3feSDongsu Park if (!iov_iter_count(&iter)) 10239124d3feSDongsu Park break; 1024f9c78b2bSJens Axboe 10259124d3feSDongsu Park if (ret < bvec->bv_len) 10269124d3feSDongsu Park return -EFAULT; 1027f9c78b2bSJens Axboe } 1028f9c78b2bSJens Axboe 10299124d3feSDongsu Park return 0; 1030f9c78b2bSJens Axboe } 1031f9c78b2bSJens Axboe 10329124d3feSDongsu Park /** 10339124d3feSDongsu Park * bio_copy_to_iter - copy all pages from bio to iov_iter 10349124d3feSDongsu Park * @bio: The &struct bio which describes the I/O as source 10359124d3feSDongsu Park * @iter: iov_iter as destination 10369124d3feSDongsu Park * 10379124d3feSDongsu Park * Copy all pages from bio to iov_iter. 10389124d3feSDongsu Park * Returns 0 on success, or error on failure. 10399124d3feSDongsu Park */ 10409124d3feSDongsu Park static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter) 10419124d3feSDongsu Park { 10429124d3feSDongsu Park int i; 10439124d3feSDongsu Park struct bio_vec *bvec; 10449124d3feSDongsu Park 10459124d3feSDongsu Park bio_for_each_segment_all(bvec, bio, i) { 10469124d3feSDongsu Park ssize_t ret; 10479124d3feSDongsu Park 10489124d3feSDongsu Park ret = copy_page_to_iter(bvec->bv_page, 10499124d3feSDongsu Park bvec->bv_offset, 10509124d3feSDongsu Park bvec->bv_len, 10519124d3feSDongsu Park &iter); 10529124d3feSDongsu Park 10539124d3feSDongsu Park if (!iov_iter_count(&iter)) 10549124d3feSDongsu Park break; 10559124d3feSDongsu Park 10569124d3feSDongsu Park if (ret < bvec->bv_len) 10579124d3feSDongsu Park return -EFAULT; 10589124d3feSDongsu Park } 10599124d3feSDongsu Park 10609124d3feSDongsu Park return 0; 1061f9c78b2bSJens Axboe } 1062f9c78b2bSJens Axboe 10631dfa0f68SChristoph Hellwig static void bio_free_pages(struct bio *bio) 10641dfa0f68SChristoph Hellwig { 10651dfa0f68SChristoph Hellwig struct bio_vec *bvec; 10661dfa0f68SChristoph Hellwig int i; 10671dfa0f68SChristoph Hellwig 10681dfa0f68SChristoph Hellwig bio_for_each_segment_all(bvec, bio, i) 10691dfa0f68SChristoph Hellwig __free_page(bvec->bv_page); 10701dfa0f68SChristoph Hellwig } 10711dfa0f68SChristoph Hellwig 1072f9c78b2bSJens Axboe /** 1073f9c78b2bSJens Axboe * bio_uncopy_user - finish previously mapped bio 1074f9c78b2bSJens Axboe * @bio: bio being terminated 1075f9c78b2bSJens Axboe * 1076ddad8dd0SChristoph Hellwig * Free pages allocated from bio_copy_user_iov() and write back data 1077f9c78b2bSJens Axboe * to user space in case of a read. 1078f9c78b2bSJens Axboe */ 1079f9c78b2bSJens Axboe int bio_uncopy_user(struct bio *bio) 1080f9c78b2bSJens Axboe { 1081f9c78b2bSJens Axboe struct bio_map_data *bmd = bio->bi_private; 10821dfa0f68SChristoph Hellwig int ret = 0; 1083f9c78b2bSJens Axboe 1084f9c78b2bSJens Axboe if (!bio_flagged(bio, BIO_NULL_MAPPED)) { 1085f9c78b2bSJens Axboe /* 1086f9c78b2bSJens Axboe * if we're in a workqueue, the request is orphaned, so 10872d99b55dSHannes Reinecke * don't copy into a random user address space, just free 10882d99b55dSHannes Reinecke * and return -EINTR so user space doesn't expect any data. 1089f9c78b2bSJens Axboe */ 10902d99b55dSHannes Reinecke if (!current->mm) 10912d99b55dSHannes Reinecke ret = -EINTR; 10922d99b55dSHannes Reinecke else if (bio_data_dir(bio) == READ) 10939124d3feSDongsu Park ret = bio_copy_to_iter(bio, bmd->iter); 10941dfa0f68SChristoph Hellwig if (bmd->is_our_pages) 10951dfa0f68SChristoph Hellwig bio_free_pages(bio); 1096f9c78b2bSJens Axboe } 1097f9c78b2bSJens Axboe kfree(bmd); 1098f9c78b2bSJens Axboe bio_put(bio); 1099f9c78b2bSJens Axboe return ret; 1100f9c78b2bSJens Axboe } 1101f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_uncopy_user); 1102f9c78b2bSJens Axboe 1103f9c78b2bSJens Axboe /** 1104f9c78b2bSJens Axboe * bio_copy_user_iov - copy user data to bio 1105f9c78b2bSJens Axboe * @q: destination block queue 1106f9c78b2bSJens Axboe * @map_data: pointer to the rq_map_data holding pages (if necessary) 110726e49cfcSKent Overstreet * @iter: iovec iterator 1108f9c78b2bSJens Axboe * @gfp_mask: memory allocation flags 1109f9c78b2bSJens Axboe * 1110f9c78b2bSJens Axboe * Prepares and returns a bio for indirect user io, bouncing data 1111f9c78b2bSJens Axboe * to/from kernel pages as necessary. Must be paired with 1112f9c78b2bSJens Axboe * call bio_uncopy_user() on io completion. 1113f9c78b2bSJens Axboe */ 1114f9c78b2bSJens Axboe struct bio *bio_copy_user_iov(struct request_queue *q, 1115f9c78b2bSJens Axboe struct rq_map_data *map_data, 111626e49cfcSKent Overstreet const struct iov_iter *iter, 111726e49cfcSKent Overstreet gfp_t gfp_mask) 1118f9c78b2bSJens Axboe { 1119f9c78b2bSJens Axboe struct bio_map_data *bmd; 1120f9c78b2bSJens Axboe struct page *page; 1121f9c78b2bSJens Axboe struct bio *bio; 1122f9c78b2bSJens Axboe int i, ret; 1123f9c78b2bSJens Axboe int nr_pages = 0; 112426e49cfcSKent Overstreet unsigned int len = iter->count; 1125bd5ceceaSGeliang Tang unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0; 1126f9c78b2bSJens Axboe 112726e49cfcSKent Overstreet for (i = 0; i < iter->nr_segs; i++) { 1128f9c78b2bSJens Axboe unsigned long uaddr; 1129f9c78b2bSJens Axboe unsigned long end; 1130f9c78b2bSJens Axboe unsigned long start; 1131f9c78b2bSJens Axboe 113226e49cfcSKent Overstreet uaddr = (unsigned long) iter->iov[i].iov_base; 113326e49cfcSKent Overstreet end = (uaddr + iter->iov[i].iov_len + PAGE_SIZE - 1) 113426e49cfcSKent Overstreet >> PAGE_SHIFT; 1135f9c78b2bSJens Axboe start = uaddr >> PAGE_SHIFT; 1136f9c78b2bSJens Axboe 1137f9c78b2bSJens Axboe /* 1138f9c78b2bSJens Axboe * Overflow, abort 1139f9c78b2bSJens Axboe */ 1140f9c78b2bSJens Axboe if (end < start) 1141f9c78b2bSJens Axboe return ERR_PTR(-EINVAL); 1142f9c78b2bSJens Axboe 1143f9c78b2bSJens Axboe nr_pages += end - start; 1144f9c78b2bSJens Axboe } 1145f9c78b2bSJens Axboe 1146f9c78b2bSJens Axboe if (offset) 1147f9c78b2bSJens Axboe nr_pages++; 1148f9c78b2bSJens Axboe 114926e49cfcSKent Overstreet bmd = bio_alloc_map_data(iter->nr_segs, gfp_mask); 1150f9c78b2bSJens Axboe if (!bmd) 1151f9c78b2bSJens Axboe return ERR_PTR(-ENOMEM); 1152f9c78b2bSJens Axboe 115326e49cfcSKent Overstreet /* 115426e49cfcSKent Overstreet * We need to do a deep copy of the iov_iter including the iovecs. 115526e49cfcSKent Overstreet * The caller provided iov might point to an on-stack or otherwise 115626e49cfcSKent Overstreet * shortlived one. 115726e49cfcSKent Overstreet */ 115826e49cfcSKent Overstreet bmd->is_our_pages = map_data ? 0 : 1; 115926e49cfcSKent Overstreet memcpy(bmd->iov, iter->iov, sizeof(struct iovec) * iter->nr_segs); 116026e49cfcSKent Overstreet iov_iter_init(&bmd->iter, iter->type, bmd->iov, 116126e49cfcSKent Overstreet iter->nr_segs, iter->count); 116226e49cfcSKent Overstreet 1163f9c78b2bSJens Axboe ret = -ENOMEM; 1164f9c78b2bSJens Axboe bio = bio_kmalloc(gfp_mask, nr_pages); 1165f9c78b2bSJens Axboe if (!bio) 1166f9c78b2bSJens Axboe goto out_bmd; 1167f9c78b2bSJens Axboe 116826e49cfcSKent Overstreet if (iter->type & WRITE) 1169f9c78b2bSJens Axboe bio->bi_rw |= REQ_WRITE; 1170f9c78b2bSJens Axboe 1171f9c78b2bSJens Axboe ret = 0; 1172f9c78b2bSJens Axboe 1173f9c78b2bSJens Axboe if (map_data) { 1174f9c78b2bSJens Axboe nr_pages = 1 << map_data->page_order; 1175f9c78b2bSJens Axboe i = map_data->offset / PAGE_SIZE; 1176f9c78b2bSJens Axboe } 1177f9c78b2bSJens Axboe while (len) { 1178f9c78b2bSJens Axboe unsigned int bytes = PAGE_SIZE; 1179f9c78b2bSJens Axboe 1180f9c78b2bSJens Axboe bytes -= offset; 1181f9c78b2bSJens Axboe 1182f9c78b2bSJens Axboe if (bytes > len) 1183f9c78b2bSJens Axboe bytes = len; 1184f9c78b2bSJens Axboe 1185f9c78b2bSJens Axboe if (map_data) { 1186f9c78b2bSJens Axboe if (i == map_data->nr_entries * nr_pages) { 1187f9c78b2bSJens Axboe ret = -ENOMEM; 1188f9c78b2bSJens Axboe break; 1189f9c78b2bSJens Axboe } 1190f9c78b2bSJens Axboe 1191f9c78b2bSJens Axboe page = map_data->pages[i / nr_pages]; 1192f9c78b2bSJens Axboe page += (i % nr_pages); 1193f9c78b2bSJens Axboe 1194f9c78b2bSJens Axboe i++; 1195f9c78b2bSJens Axboe } else { 1196f9c78b2bSJens Axboe page = alloc_page(q->bounce_gfp | gfp_mask); 1197f9c78b2bSJens Axboe if (!page) { 1198f9c78b2bSJens Axboe ret = -ENOMEM; 1199f9c78b2bSJens Axboe break; 1200f9c78b2bSJens Axboe } 1201f9c78b2bSJens Axboe } 1202f9c78b2bSJens Axboe 1203f9c78b2bSJens Axboe if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) 1204f9c78b2bSJens Axboe break; 1205f9c78b2bSJens Axboe 1206f9c78b2bSJens Axboe len -= bytes; 1207f9c78b2bSJens Axboe offset = 0; 1208f9c78b2bSJens Axboe } 1209f9c78b2bSJens Axboe 1210f9c78b2bSJens Axboe if (ret) 1211f9c78b2bSJens Axboe goto cleanup; 1212f9c78b2bSJens Axboe 1213f9c78b2bSJens Axboe /* 1214f9c78b2bSJens Axboe * success 1215f9c78b2bSJens Axboe */ 121626e49cfcSKent Overstreet if (((iter->type & WRITE) && (!map_data || !map_data->null_mapped)) || 1217f9c78b2bSJens Axboe (map_data && map_data->from_user)) { 12189124d3feSDongsu Park ret = bio_copy_from_iter(bio, *iter); 1219f9c78b2bSJens Axboe if (ret) 1220f9c78b2bSJens Axboe goto cleanup; 1221f9c78b2bSJens Axboe } 1222f9c78b2bSJens Axboe 122326e49cfcSKent Overstreet bio->bi_private = bmd; 1224f9c78b2bSJens Axboe return bio; 1225f9c78b2bSJens Axboe cleanup: 1226f9c78b2bSJens Axboe if (!map_data) 12271dfa0f68SChristoph Hellwig bio_free_pages(bio); 1228f9c78b2bSJens Axboe bio_put(bio); 1229f9c78b2bSJens Axboe out_bmd: 1230f9c78b2bSJens Axboe kfree(bmd); 1231f9c78b2bSJens Axboe return ERR_PTR(ret); 1232f9c78b2bSJens Axboe } 1233f9c78b2bSJens Axboe 123437f19e57SChristoph Hellwig /** 123537f19e57SChristoph Hellwig * bio_map_user_iov - map user iovec into bio 123637f19e57SChristoph Hellwig * @q: the struct request_queue for the bio 123737f19e57SChristoph Hellwig * @iter: iovec iterator 123837f19e57SChristoph Hellwig * @gfp_mask: memory allocation flags 123937f19e57SChristoph Hellwig * 124037f19e57SChristoph Hellwig * Map the user space address into a bio suitable for io to a block 124137f19e57SChristoph Hellwig * device. Returns an error pointer in case of error. 124237f19e57SChristoph Hellwig */ 124337f19e57SChristoph Hellwig struct bio *bio_map_user_iov(struct request_queue *q, 124426e49cfcSKent Overstreet const struct iov_iter *iter, 124526e49cfcSKent Overstreet gfp_t gfp_mask) 1246f9c78b2bSJens Axboe { 124726e49cfcSKent Overstreet int j; 1248f9c78b2bSJens Axboe int nr_pages = 0; 1249f9c78b2bSJens Axboe struct page **pages; 1250f9c78b2bSJens Axboe struct bio *bio; 1251f9c78b2bSJens Axboe int cur_page = 0; 1252f9c78b2bSJens Axboe int ret, offset; 125326e49cfcSKent Overstreet struct iov_iter i; 125426e49cfcSKent Overstreet struct iovec iov; 1255f9c78b2bSJens Axboe 125626e49cfcSKent Overstreet iov_for_each(iov, i, *iter) { 125726e49cfcSKent Overstreet unsigned long uaddr = (unsigned long) iov.iov_base; 125826e49cfcSKent Overstreet unsigned long len = iov.iov_len; 1259f9c78b2bSJens Axboe unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; 1260f9c78b2bSJens Axboe unsigned long start = uaddr >> PAGE_SHIFT; 1261f9c78b2bSJens Axboe 1262f9c78b2bSJens Axboe /* 1263f9c78b2bSJens Axboe * Overflow, abort 1264f9c78b2bSJens Axboe */ 1265f9c78b2bSJens Axboe if (end < start) 1266f9c78b2bSJens Axboe return ERR_PTR(-EINVAL); 1267f9c78b2bSJens Axboe 1268f9c78b2bSJens Axboe nr_pages += end - start; 1269f9c78b2bSJens Axboe /* 1270f9c78b2bSJens Axboe * buffer must be aligned to at least hardsector size for now 1271f9c78b2bSJens Axboe */ 1272f9c78b2bSJens Axboe if (uaddr & queue_dma_alignment(q)) 1273f9c78b2bSJens Axboe return ERR_PTR(-EINVAL); 1274f9c78b2bSJens Axboe } 1275f9c78b2bSJens Axboe 1276f9c78b2bSJens Axboe if (!nr_pages) 1277f9c78b2bSJens Axboe return ERR_PTR(-EINVAL); 1278f9c78b2bSJens Axboe 1279f9c78b2bSJens Axboe bio = bio_kmalloc(gfp_mask, nr_pages); 1280f9c78b2bSJens Axboe if (!bio) 1281f9c78b2bSJens Axboe return ERR_PTR(-ENOMEM); 1282f9c78b2bSJens Axboe 1283f9c78b2bSJens Axboe ret = -ENOMEM; 1284f9c78b2bSJens Axboe pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask); 1285f9c78b2bSJens Axboe if (!pages) 1286f9c78b2bSJens Axboe goto out; 1287f9c78b2bSJens Axboe 128826e49cfcSKent Overstreet iov_for_each(iov, i, *iter) { 128926e49cfcSKent Overstreet unsigned long uaddr = (unsigned long) iov.iov_base; 129026e49cfcSKent Overstreet unsigned long len = iov.iov_len; 1291f9c78b2bSJens Axboe unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; 1292f9c78b2bSJens Axboe unsigned long start = uaddr >> PAGE_SHIFT; 1293f9c78b2bSJens Axboe const int local_nr_pages = end - start; 1294f9c78b2bSJens Axboe const int page_limit = cur_page + local_nr_pages; 1295f9c78b2bSJens Axboe 1296f9c78b2bSJens Axboe ret = get_user_pages_fast(uaddr, local_nr_pages, 129726e49cfcSKent Overstreet (iter->type & WRITE) != WRITE, 129826e49cfcSKent Overstreet &pages[cur_page]); 1299f9c78b2bSJens Axboe if (ret < local_nr_pages) { 1300f9c78b2bSJens Axboe ret = -EFAULT; 1301f9c78b2bSJens Axboe goto out_unmap; 1302f9c78b2bSJens Axboe } 1303f9c78b2bSJens Axboe 1304bd5ceceaSGeliang Tang offset = offset_in_page(uaddr); 1305f9c78b2bSJens Axboe for (j = cur_page; j < page_limit; j++) { 1306f9c78b2bSJens Axboe unsigned int bytes = PAGE_SIZE - offset; 1307f9c78b2bSJens Axboe 1308f9c78b2bSJens Axboe if (len <= 0) 1309f9c78b2bSJens Axboe break; 1310f9c78b2bSJens Axboe 1311f9c78b2bSJens Axboe if (bytes > len) 1312f9c78b2bSJens Axboe bytes = len; 1313f9c78b2bSJens Axboe 1314f9c78b2bSJens Axboe /* 1315f9c78b2bSJens Axboe * sorry... 1316f9c78b2bSJens Axboe */ 1317f9c78b2bSJens Axboe if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < 1318f9c78b2bSJens Axboe bytes) 1319f9c78b2bSJens Axboe break; 1320f9c78b2bSJens Axboe 1321f9c78b2bSJens Axboe len -= bytes; 1322f9c78b2bSJens Axboe offset = 0; 1323f9c78b2bSJens Axboe } 1324f9c78b2bSJens Axboe 1325f9c78b2bSJens Axboe cur_page = j; 1326f9c78b2bSJens Axboe /* 1327f9c78b2bSJens Axboe * release the pages we didn't map into the bio, if any 1328f9c78b2bSJens Axboe */ 1329f9c78b2bSJens Axboe while (j < page_limit) 133009cbfeafSKirill A. Shutemov put_page(pages[j++]); 1331f9c78b2bSJens Axboe } 1332f9c78b2bSJens Axboe 1333f9c78b2bSJens Axboe kfree(pages); 1334f9c78b2bSJens Axboe 1335f9c78b2bSJens Axboe /* 1336f9c78b2bSJens Axboe * set data direction, and check if mapped pages need bouncing 1337f9c78b2bSJens Axboe */ 133826e49cfcSKent Overstreet if (iter->type & WRITE) 1339f9c78b2bSJens Axboe bio->bi_rw |= REQ_WRITE; 1340f9c78b2bSJens Axboe 1341b7c44ed9SJens Axboe bio_set_flag(bio, BIO_USER_MAPPED); 134237f19e57SChristoph Hellwig 134337f19e57SChristoph Hellwig /* 134437f19e57SChristoph Hellwig * subtle -- if __bio_map_user() ended up bouncing a bio, 134537f19e57SChristoph Hellwig * it would normally disappear when its bi_end_io is run. 134637f19e57SChristoph Hellwig * however, we need it for the unmap, so grab an extra 134737f19e57SChristoph Hellwig * reference to it 134837f19e57SChristoph Hellwig */ 134937f19e57SChristoph Hellwig bio_get(bio); 1350f9c78b2bSJens Axboe return bio; 1351f9c78b2bSJens Axboe 1352f9c78b2bSJens Axboe out_unmap: 135326e49cfcSKent Overstreet for (j = 0; j < nr_pages; j++) { 135426e49cfcSKent Overstreet if (!pages[j]) 1355f9c78b2bSJens Axboe break; 135609cbfeafSKirill A. Shutemov put_page(pages[j]); 1357f9c78b2bSJens Axboe } 1358f9c78b2bSJens Axboe out: 1359f9c78b2bSJens Axboe kfree(pages); 1360f9c78b2bSJens Axboe bio_put(bio); 1361f9c78b2bSJens Axboe return ERR_PTR(ret); 1362f9c78b2bSJens Axboe } 1363f9c78b2bSJens Axboe 1364f9c78b2bSJens Axboe static void __bio_unmap_user(struct bio *bio) 1365f9c78b2bSJens Axboe { 1366f9c78b2bSJens Axboe struct bio_vec *bvec; 1367f9c78b2bSJens Axboe int i; 1368f9c78b2bSJens Axboe 1369f9c78b2bSJens Axboe /* 1370f9c78b2bSJens Axboe * make sure we dirty pages we wrote to 1371f9c78b2bSJens Axboe */ 1372f9c78b2bSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 1373f9c78b2bSJens Axboe if (bio_data_dir(bio) == READ) 1374f9c78b2bSJens Axboe set_page_dirty_lock(bvec->bv_page); 1375f9c78b2bSJens Axboe 137609cbfeafSKirill A. Shutemov put_page(bvec->bv_page); 1377f9c78b2bSJens Axboe } 1378f9c78b2bSJens Axboe 1379f9c78b2bSJens Axboe bio_put(bio); 1380f9c78b2bSJens Axboe } 1381f9c78b2bSJens Axboe 1382f9c78b2bSJens Axboe /** 1383f9c78b2bSJens Axboe * bio_unmap_user - unmap a bio 1384f9c78b2bSJens Axboe * @bio: the bio being unmapped 1385f9c78b2bSJens Axboe * 1386f9c78b2bSJens Axboe * Unmap a bio previously mapped by bio_map_user(). Must be called with 1387f9c78b2bSJens Axboe * a process context. 1388f9c78b2bSJens Axboe * 1389f9c78b2bSJens Axboe * bio_unmap_user() may sleep. 1390f9c78b2bSJens Axboe */ 1391f9c78b2bSJens Axboe void bio_unmap_user(struct bio *bio) 1392f9c78b2bSJens Axboe { 1393f9c78b2bSJens Axboe __bio_unmap_user(bio); 1394f9c78b2bSJens Axboe bio_put(bio); 1395f9c78b2bSJens Axboe } 1396f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_unmap_user); 1397f9c78b2bSJens Axboe 13984246a0b6SChristoph Hellwig static void bio_map_kern_endio(struct bio *bio) 1399f9c78b2bSJens Axboe { 1400f9c78b2bSJens Axboe bio_put(bio); 1401f9c78b2bSJens Axboe } 1402f9c78b2bSJens Axboe 140375c72b83SChristoph Hellwig /** 140475c72b83SChristoph Hellwig * bio_map_kern - map kernel address into bio 140575c72b83SChristoph Hellwig * @q: the struct request_queue for the bio 140675c72b83SChristoph Hellwig * @data: pointer to buffer to map 140775c72b83SChristoph Hellwig * @len: length in bytes 140875c72b83SChristoph Hellwig * @gfp_mask: allocation flags for bio allocation 140975c72b83SChristoph Hellwig * 141075c72b83SChristoph Hellwig * Map the kernel address into a bio suitable for io to a block 141175c72b83SChristoph Hellwig * device. Returns an error pointer in case of error. 141275c72b83SChristoph Hellwig */ 141375c72b83SChristoph Hellwig struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len, 141475c72b83SChristoph Hellwig gfp_t gfp_mask) 1415f9c78b2bSJens Axboe { 1416f9c78b2bSJens Axboe unsigned long kaddr = (unsigned long)data; 1417f9c78b2bSJens Axboe unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; 1418f9c78b2bSJens Axboe unsigned long start = kaddr >> PAGE_SHIFT; 1419f9c78b2bSJens Axboe const int nr_pages = end - start; 1420f9c78b2bSJens Axboe int offset, i; 1421f9c78b2bSJens Axboe struct bio *bio; 1422f9c78b2bSJens Axboe 1423f9c78b2bSJens Axboe bio = bio_kmalloc(gfp_mask, nr_pages); 1424f9c78b2bSJens Axboe if (!bio) 1425f9c78b2bSJens Axboe return ERR_PTR(-ENOMEM); 1426f9c78b2bSJens Axboe 1427f9c78b2bSJens Axboe offset = offset_in_page(kaddr); 1428f9c78b2bSJens Axboe for (i = 0; i < nr_pages; i++) { 1429f9c78b2bSJens Axboe unsigned int bytes = PAGE_SIZE - offset; 1430f9c78b2bSJens Axboe 1431f9c78b2bSJens Axboe if (len <= 0) 1432f9c78b2bSJens Axboe break; 1433f9c78b2bSJens Axboe 1434f9c78b2bSJens Axboe if (bytes > len) 1435f9c78b2bSJens Axboe bytes = len; 1436f9c78b2bSJens Axboe 1437f9c78b2bSJens Axboe if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, 143875c72b83SChristoph Hellwig offset) < bytes) { 143975c72b83SChristoph Hellwig /* we don't support partial mappings */ 144075c72b83SChristoph Hellwig bio_put(bio); 144175c72b83SChristoph Hellwig return ERR_PTR(-EINVAL); 144275c72b83SChristoph Hellwig } 1443f9c78b2bSJens Axboe 1444f9c78b2bSJens Axboe data += bytes; 1445f9c78b2bSJens Axboe len -= bytes; 1446f9c78b2bSJens Axboe offset = 0; 1447f9c78b2bSJens Axboe } 1448f9c78b2bSJens Axboe 1449f9c78b2bSJens Axboe bio->bi_end_io = bio_map_kern_endio; 1450f9c78b2bSJens Axboe return bio; 1451f9c78b2bSJens Axboe } 1452f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_map_kern); 1453f9c78b2bSJens Axboe 14544246a0b6SChristoph Hellwig static void bio_copy_kern_endio(struct bio *bio) 1455f9c78b2bSJens Axboe { 14561dfa0f68SChristoph Hellwig bio_free_pages(bio); 14571dfa0f68SChristoph Hellwig bio_put(bio); 14581dfa0f68SChristoph Hellwig } 14591dfa0f68SChristoph Hellwig 14604246a0b6SChristoph Hellwig static void bio_copy_kern_endio_read(struct bio *bio) 14611dfa0f68SChristoph Hellwig { 146242d2683aSChristoph Hellwig char *p = bio->bi_private; 14631dfa0f68SChristoph Hellwig struct bio_vec *bvec; 1464f9c78b2bSJens Axboe int i; 1465f9c78b2bSJens Axboe 1466f9c78b2bSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 14671dfa0f68SChristoph Hellwig memcpy(p, page_address(bvec->bv_page), bvec->bv_len); 1468f9c78b2bSJens Axboe p += bvec->bv_len; 1469f9c78b2bSJens Axboe } 1470f9c78b2bSJens Axboe 14714246a0b6SChristoph Hellwig bio_copy_kern_endio(bio); 1472f9c78b2bSJens Axboe } 1473f9c78b2bSJens Axboe 1474f9c78b2bSJens Axboe /** 1475f9c78b2bSJens Axboe * bio_copy_kern - copy kernel address into bio 1476f9c78b2bSJens Axboe * @q: the struct request_queue for the bio 1477f9c78b2bSJens Axboe * @data: pointer to buffer to copy 1478f9c78b2bSJens Axboe * @len: length in bytes 1479f9c78b2bSJens Axboe * @gfp_mask: allocation flags for bio and page allocation 1480f9c78b2bSJens Axboe * @reading: data direction is READ 1481f9c78b2bSJens Axboe * 1482f9c78b2bSJens Axboe * copy the kernel address into a bio suitable for io to a block 1483f9c78b2bSJens Axboe * device. Returns an error pointer in case of error. 1484f9c78b2bSJens Axboe */ 1485f9c78b2bSJens Axboe struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, 1486f9c78b2bSJens Axboe gfp_t gfp_mask, int reading) 1487f9c78b2bSJens Axboe { 148842d2683aSChristoph Hellwig unsigned long kaddr = (unsigned long)data; 148942d2683aSChristoph Hellwig unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; 149042d2683aSChristoph Hellwig unsigned long start = kaddr >> PAGE_SHIFT; 149142d2683aSChristoph Hellwig struct bio *bio; 1492f9c78b2bSJens Axboe void *p = data; 14931dfa0f68SChristoph Hellwig int nr_pages = 0; 1494f9c78b2bSJens Axboe 149542d2683aSChristoph Hellwig /* 149642d2683aSChristoph Hellwig * Overflow, abort 149742d2683aSChristoph Hellwig */ 149842d2683aSChristoph Hellwig if (end < start) 149942d2683aSChristoph Hellwig return ERR_PTR(-EINVAL); 1500f9c78b2bSJens Axboe 150142d2683aSChristoph Hellwig nr_pages = end - start; 150242d2683aSChristoph Hellwig bio = bio_kmalloc(gfp_mask, nr_pages); 150342d2683aSChristoph Hellwig if (!bio) 150442d2683aSChristoph Hellwig return ERR_PTR(-ENOMEM); 150542d2683aSChristoph Hellwig 150642d2683aSChristoph Hellwig while (len) { 150742d2683aSChristoph Hellwig struct page *page; 150842d2683aSChristoph Hellwig unsigned int bytes = PAGE_SIZE; 150942d2683aSChristoph Hellwig 151042d2683aSChristoph Hellwig if (bytes > len) 151142d2683aSChristoph Hellwig bytes = len; 151242d2683aSChristoph Hellwig 151342d2683aSChristoph Hellwig page = alloc_page(q->bounce_gfp | gfp_mask); 151442d2683aSChristoph Hellwig if (!page) 151542d2683aSChristoph Hellwig goto cleanup; 151642d2683aSChristoph Hellwig 151742d2683aSChristoph Hellwig if (!reading) 151842d2683aSChristoph Hellwig memcpy(page_address(page), p, bytes); 151942d2683aSChristoph Hellwig 152042d2683aSChristoph Hellwig if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) 152142d2683aSChristoph Hellwig break; 152242d2683aSChristoph Hellwig 152342d2683aSChristoph Hellwig len -= bytes; 152442d2683aSChristoph Hellwig p += bytes; 1525f9c78b2bSJens Axboe } 1526f9c78b2bSJens Axboe 15271dfa0f68SChristoph Hellwig if (reading) { 15281dfa0f68SChristoph Hellwig bio->bi_end_io = bio_copy_kern_endio_read; 152942d2683aSChristoph Hellwig bio->bi_private = data; 15301dfa0f68SChristoph Hellwig } else { 1531f9c78b2bSJens Axboe bio->bi_end_io = bio_copy_kern_endio; 15321dfa0f68SChristoph Hellwig bio->bi_rw |= REQ_WRITE; 15331dfa0f68SChristoph Hellwig } 15341dfa0f68SChristoph Hellwig 1535f9c78b2bSJens Axboe return bio; 153642d2683aSChristoph Hellwig 153742d2683aSChristoph Hellwig cleanup: 15381dfa0f68SChristoph Hellwig bio_free_pages(bio); 153942d2683aSChristoph Hellwig bio_put(bio); 154042d2683aSChristoph Hellwig return ERR_PTR(-ENOMEM); 1541f9c78b2bSJens Axboe } 1542f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_copy_kern); 1543f9c78b2bSJens Axboe 1544f9c78b2bSJens Axboe /* 1545f9c78b2bSJens Axboe * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions 1546f9c78b2bSJens Axboe * for performing direct-IO in BIOs. 1547f9c78b2bSJens Axboe * 1548f9c78b2bSJens Axboe * The problem is that we cannot run set_page_dirty() from interrupt context 1549f9c78b2bSJens Axboe * because the required locks are not interrupt-safe. So what we can do is to 1550f9c78b2bSJens Axboe * mark the pages dirty _before_ performing IO. And in interrupt context, 1551f9c78b2bSJens Axboe * check that the pages are still dirty. If so, fine. If not, redirty them 1552f9c78b2bSJens Axboe * in process context. 1553f9c78b2bSJens Axboe * 1554f9c78b2bSJens Axboe * We special-case compound pages here: normally this means reads into hugetlb 1555f9c78b2bSJens Axboe * pages. The logic in here doesn't really work right for compound pages 1556f9c78b2bSJens Axboe * because the VM does not uniformly chase down the head page in all cases. 1557f9c78b2bSJens Axboe * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't 1558f9c78b2bSJens Axboe * handle them at all. So we skip compound pages here at an early stage. 1559f9c78b2bSJens Axboe * 1560f9c78b2bSJens Axboe * Note that this code is very hard to test under normal circumstances because 1561f9c78b2bSJens Axboe * direct-io pins the pages with get_user_pages(). This makes 1562f9c78b2bSJens Axboe * is_page_cache_freeable return false, and the VM will not clean the pages. 1563f9c78b2bSJens Axboe * But other code (eg, flusher threads) could clean the pages if they are mapped 1564f9c78b2bSJens Axboe * pagecache. 1565f9c78b2bSJens Axboe * 1566f9c78b2bSJens Axboe * Simply disabling the call to bio_set_pages_dirty() is a good way to test the 1567f9c78b2bSJens Axboe * deferred bio dirtying paths. 1568f9c78b2bSJens Axboe */ 1569f9c78b2bSJens Axboe 1570f9c78b2bSJens Axboe /* 1571f9c78b2bSJens Axboe * bio_set_pages_dirty() will mark all the bio's pages as dirty. 1572f9c78b2bSJens Axboe */ 1573f9c78b2bSJens Axboe void bio_set_pages_dirty(struct bio *bio) 1574f9c78b2bSJens Axboe { 1575f9c78b2bSJens Axboe struct bio_vec *bvec; 1576f9c78b2bSJens Axboe int i; 1577f9c78b2bSJens Axboe 1578f9c78b2bSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 1579f9c78b2bSJens Axboe struct page *page = bvec->bv_page; 1580f9c78b2bSJens Axboe 1581f9c78b2bSJens Axboe if (page && !PageCompound(page)) 1582f9c78b2bSJens Axboe set_page_dirty_lock(page); 1583f9c78b2bSJens Axboe } 1584f9c78b2bSJens Axboe } 1585f9c78b2bSJens Axboe 1586f9c78b2bSJens Axboe static void bio_release_pages(struct bio *bio) 1587f9c78b2bSJens Axboe { 1588f9c78b2bSJens Axboe struct bio_vec *bvec; 1589f9c78b2bSJens Axboe int i; 1590f9c78b2bSJens Axboe 1591f9c78b2bSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 1592f9c78b2bSJens Axboe struct page *page = bvec->bv_page; 1593f9c78b2bSJens Axboe 1594f9c78b2bSJens Axboe if (page) 1595f9c78b2bSJens Axboe put_page(page); 1596f9c78b2bSJens Axboe } 1597f9c78b2bSJens Axboe } 1598f9c78b2bSJens Axboe 1599f9c78b2bSJens Axboe /* 1600f9c78b2bSJens Axboe * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. 1601f9c78b2bSJens Axboe * If they are, then fine. If, however, some pages are clean then they must 1602f9c78b2bSJens Axboe * have been written out during the direct-IO read. So we take another ref on 1603f9c78b2bSJens Axboe * the BIO and the offending pages and re-dirty the pages in process context. 1604f9c78b2bSJens Axboe * 1605f9c78b2bSJens Axboe * It is expected that bio_check_pages_dirty() will wholly own the BIO from 1606ea1754a0SKirill A. Shutemov * here on. It will run one put_page() against each page and will run one 1607ea1754a0SKirill A. Shutemov * bio_put() against the BIO. 1608f9c78b2bSJens Axboe */ 1609f9c78b2bSJens Axboe 1610f9c78b2bSJens Axboe static void bio_dirty_fn(struct work_struct *work); 1611f9c78b2bSJens Axboe 1612f9c78b2bSJens Axboe static DECLARE_WORK(bio_dirty_work, bio_dirty_fn); 1613f9c78b2bSJens Axboe static DEFINE_SPINLOCK(bio_dirty_lock); 1614f9c78b2bSJens Axboe static struct bio *bio_dirty_list; 1615f9c78b2bSJens Axboe 1616f9c78b2bSJens Axboe /* 1617f9c78b2bSJens Axboe * This runs in process context 1618f9c78b2bSJens Axboe */ 1619f9c78b2bSJens Axboe static void bio_dirty_fn(struct work_struct *work) 1620f9c78b2bSJens Axboe { 1621f9c78b2bSJens Axboe unsigned long flags; 1622f9c78b2bSJens Axboe struct bio *bio; 1623f9c78b2bSJens Axboe 1624f9c78b2bSJens Axboe spin_lock_irqsave(&bio_dirty_lock, flags); 1625f9c78b2bSJens Axboe bio = bio_dirty_list; 1626f9c78b2bSJens Axboe bio_dirty_list = NULL; 1627f9c78b2bSJens Axboe spin_unlock_irqrestore(&bio_dirty_lock, flags); 1628f9c78b2bSJens Axboe 1629f9c78b2bSJens Axboe while (bio) { 1630f9c78b2bSJens Axboe struct bio *next = bio->bi_private; 1631f9c78b2bSJens Axboe 1632f9c78b2bSJens Axboe bio_set_pages_dirty(bio); 1633f9c78b2bSJens Axboe bio_release_pages(bio); 1634f9c78b2bSJens Axboe bio_put(bio); 1635f9c78b2bSJens Axboe bio = next; 1636f9c78b2bSJens Axboe } 1637f9c78b2bSJens Axboe } 1638f9c78b2bSJens Axboe 1639f9c78b2bSJens Axboe void bio_check_pages_dirty(struct bio *bio) 1640f9c78b2bSJens Axboe { 1641f9c78b2bSJens Axboe struct bio_vec *bvec; 1642f9c78b2bSJens Axboe int nr_clean_pages = 0; 1643f9c78b2bSJens Axboe int i; 1644f9c78b2bSJens Axboe 1645f9c78b2bSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 1646f9c78b2bSJens Axboe struct page *page = bvec->bv_page; 1647f9c78b2bSJens Axboe 1648f9c78b2bSJens Axboe if (PageDirty(page) || PageCompound(page)) { 164909cbfeafSKirill A. Shutemov put_page(page); 1650f9c78b2bSJens Axboe bvec->bv_page = NULL; 1651f9c78b2bSJens Axboe } else { 1652f9c78b2bSJens Axboe nr_clean_pages++; 1653f9c78b2bSJens Axboe } 1654f9c78b2bSJens Axboe } 1655f9c78b2bSJens Axboe 1656f9c78b2bSJens Axboe if (nr_clean_pages) { 1657f9c78b2bSJens Axboe unsigned long flags; 1658f9c78b2bSJens Axboe 1659f9c78b2bSJens Axboe spin_lock_irqsave(&bio_dirty_lock, flags); 1660f9c78b2bSJens Axboe bio->bi_private = bio_dirty_list; 1661f9c78b2bSJens Axboe bio_dirty_list = bio; 1662f9c78b2bSJens Axboe spin_unlock_irqrestore(&bio_dirty_lock, flags); 1663f9c78b2bSJens Axboe schedule_work(&bio_dirty_work); 1664f9c78b2bSJens Axboe } else { 1665f9c78b2bSJens Axboe bio_put(bio); 1666f9c78b2bSJens Axboe } 1667f9c78b2bSJens Axboe } 1668f9c78b2bSJens Axboe 1669394ffa50SGu Zheng void generic_start_io_acct(int rw, unsigned long sectors, 1670394ffa50SGu Zheng struct hd_struct *part) 1671394ffa50SGu Zheng { 1672394ffa50SGu Zheng int cpu = part_stat_lock(); 1673394ffa50SGu Zheng 1674394ffa50SGu Zheng part_round_stats(cpu, part); 1675394ffa50SGu Zheng part_stat_inc(cpu, part, ios[rw]); 1676394ffa50SGu Zheng part_stat_add(cpu, part, sectors[rw], sectors); 1677394ffa50SGu Zheng part_inc_in_flight(part, rw); 1678394ffa50SGu Zheng 1679394ffa50SGu Zheng part_stat_unlock(); 1680394ffa50SGu Zheng } 1681394ffa50SGu Zheng EXPORT_SYMBOL(generic_start_io_acct); 1682394ffa50SGu Zheng 1683394ffa50SGu Zheng void generic_end_io_acct(int rw, struct hd_struct *part, 1684394ffa50SGu Zheng unsigned long start_time) 1685394ffa50SGu Zheng { 1686394ffa50SGu Zheng unsigned long duration = jiffies - start_time; 1687394ffa50SGu Zheng int cpu = part_stat_lock(); 1688394ffa50SGu Zheng 1689394ffa50SGu Zheng part_stat_add(cpu, part, ticks[rw], duration); 1690394ffa50SGu Zheng part_round_stats(cpu, part); 1691394ffa50SGu Zheng part_dec_in_flight(part, rw); 1692394ffa50SGu Zheng 1693394ffa50SGu Zheng part_stat_unlock(); 1694394ffa50SGu Zheng } 1695394ffa50SGu Zheng EXPORT_SYMBOL(generic_end_io_acct); 1696394ffa50SGu Zheng 1697f9c78b2bSJens Axboe #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1698f9c78b2bSJens Axboe void bio_flush_dcache_pages(struct bio *bi) 1699f9c78b2bSJens Axboe { 1700f9c78b2bSJens Axboe struct bio_vec bvec; 1701f9c78b2bSJens Axboe struct bvec_iter iter; 1702f9c78b2bSJens Axboe 1703f9c78b2bSJens Axboe bio_for_each_segment(bvec, bi, iter) 1704f9c78b2bSJens Axboe flush_dcache_page(bvec.bv_page); 1705f9c78b2bSJens Axboe } 1706f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_flush_dcache_pages); 1707f9c78b2bSJens Axboe #endif 1708f9c78b2bSJens Axboe 1709c4cf5261SJens Axboe static inline bool bio_remaining_done(struct bio *bio) 1710c4cf5261SJens Axboe { 1711c4cf5261SJens Axboe /* 1712c4cf5261SJens Axboe * If we're not chaining, then ->__bi_remaining is always 1 and 1713c4cf5261SJens Axboe * we always end io on the first invocation. 1714c4cf5261SJens Axboe */ 1715c4cf5261SJens Axboe if (!bio_flagged(bio, BIO_CHAIN)) 1716c4cf5261SJens Axboe return true; 1717c4cf5261SJens Axboe 1718c4cf5261SJens Axboe BUG_ON(atomic_read(&bio->__bi_remaining) <= 0); 1719c4cf5261SJens Axboe 1720326e1dbbSMike Snitzer if (atomic_dec_and_test(&bio->__bi_remaining)) { 1721b7c44ed9SJens Axboe bio_clear_flag(bio, BIO_CHAIN); 1722c4cf5261SJens Axboe return true; 1723326e1dbbSMike Snitzer } 1724c4cf5261SJens Axboe 1725c4cf5261SJens Axboe return false; 1726c4cf5261SJens Axboe } 1727c4cf5261SJens Axboe 1728f9c78b2bSJens Axboe /** 1729f9c78b2bSJens Axboe * bio_endio - end I/O on a bio 1730f9c78b2bSJens Axboe * @bio: bio 1731f9c78b2bSJens Axboe * 1732f9c78b2bSJens Axboe * Description: 17334246a0b6SChristoph Hellwig * bio_endio() will end I/O on the whole bio. bio_endio() is the preferred 17344246a0b6SChristoph Hellwig * way to end I/O on a bio. No one should call bi_end_io() directly on a 17354246a0b6SChristoph Hellwig * bio unless they own it and thus know that it has an end_io function. 1736f9c78b2bSJens Axboe **/ 17374246a0b6SChristoph Hellwig void bio_endio(struct bio *bio) 1738f9c78b2bSJens Axboe { 1739ba8c6967SChristoph Hellwig again: 17402b885517SChristoph Hellwig if (!bio_remaining_done(bio)) 1741ba8c6967SChristoph Hellwig return; 1742f9c78b2bSJens Axboe 1743f9c78b2bSJens Axboe /* 1744ba8c6967SChristoph Hellwig * Need to have a real endio function for chained bios, otherwise 1745ba8c6967SChristoph Hellwig * various corner cases will break (like stacking block devices that 1746ba8c6967SChristoph Hellwig * save/restore bi_end_io) - however, we want to avoid unbounded 1747ba8c6967SChristoph Hellwig * recursion and blowing the stack. Tail call optimization would 1748ba8c6967SChristoph Hellwig * handle this, but compiling with frame pointers also disables 1749ba8c6967SChristoph Hellwig * gcc's sibling call optimization. 1750f9c78b2bSJens Axboe */ 1751f9c78b2bSJens Axboe if (bio->bi_end_io == bio_chain_endio) { 175238f8baaeSChristoph Hellwig bio = __bio_chain_endio(bio); 1753ba8c6967SChristoph Hellwig goto again; 1754ba8c6967SChristoph Hellwig } 1755ba8c6967SChristoph Hellwig 1756f9c78b2bSJens Axboe if (bio->bi_end_io) 17574246a0b6SChristoph Hellwig bio->bi_end_io(bio); 1758f9c78b2bSJens Axboe } 1759f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_endio); 1760f9c78b2bSJens Axboe 1761f9c78b2bSJens Axboe /** 1762f9c78b2bSJens Axboe * bio_split - split a bio 1763f9c78b2bSJens Axboe * @bio: bio to split 1764f9c78b2bSJens Axboe * @sectors: number of sectors to split from the front of @bio 1765f9c78b2bSJens Axboe * @gfp: gfp mask 1766f9c78b2bSJens Axboe * @bs: bio set to allocate from 1767f9c78b2bSJens Axboe * 1768f9c78b2bSJens Axboe * Allocates and returns a new bio which represents @sectors from the start of 1769f9c78b2bSJens Axboe * @bio, and updates @bio to represent the remaining sectors. 1770f9c78b2bSJens Axboe * 1771f3f5da62SMartin K. Petersen * Unless this is a discard request the newly allocated bio will point 1772f3f5da62SMartin K. Petersen * to @bio's bi_io_vec; it is the caller's responsibility to ensure that 1773f3f5da62SMartin K. Petersen * @bio is not freed before the split. 1774f9c78b2bSJens Axboe */ 1775f9c78b2bSJens Axboe struct bio *bio_split(struct bio *bio, int sectors, 1776f9c78b2bSJens Axboe gfp_t gfp, struct bio_set *bs) 1777f9c78b2bSJens Axboe { 1778f9c78b2bSJens Axboe struct bio *split = NULL; 1779f9c78b2bSJens Axboe 1780f9c78b2bSJens Axboe BUG_ON(sectors <= 0); 1781f9c78b2bSJens Axboe BUG_ON(sectors >= bio_sectors(bio)); 1782f9c78b2bSJens Axboe 1783f3f5da62SMartin K. Petersen /* 1784f3f5da62SMartin K. Petersen * Discards need a mutable bio_vec to accommodate the payload 1785f3f5da62SMartin K. Petersen * required by the DSM TRIM and UNMAP commands. 1786f3f5da62SMartin K. Petersen */ 1787f3f5da62SMartin K. Petersen if (bio->bi_rw & REQ_DISCARD) 1788f3f5da62SMartin K. Petersen split = bio_clone_bioset(bio, gfp, bs); 1789f3f5da62SMartin K. Petersen else 1790f9c78b2bSJens Axboe split = bio_clone_fast(bio, gfp, bs); 1791f3f5da62SMartin K. Petersen 1792f9c78b2bSJens Axboe if (!split) 1793f9c78b2bSJens Axboe return NULL; 1794f9c78b2bSJens Axboe 1795f9c78b2bSJens Axboe split->bi_iter.bi_size = sectors << 9; 1796f9c78b2bSJens Axboe 1797f9c78b2bSJens Axboe if (bio_integrity(split)) 1798f9c78b2bSJens Axboe bio_integrity_trim(split, 0, sectors); 1799f9c78b2bSJens Axboe 1800f9c78b2bSJens Axboe bio_advance(bio, split->bi_iter.bi_size); 1801f9c78b2bSJens Axboe 1802f9c78b2bSJens Axboe return split; 1803f9c78b2bSJens Axboe } 1804f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_split); 1805f9c78b2bSJens Axboe 1806f9c78b2bSJens Axboe /** 1807f9c78b2bSJens Axboe * bio_trim - trim a bio 1808f9c78b2bSJens Axboe * @bio: bio to trim 1809f9c78b2bSJens Axboe * @offset: number of sectors to trim from the front of @bio 1810f9c78b2bSJens Axboe * @size: size we want to trim @bio to, in sectors 1811f9c78b2bSJens Axboe */ 1812f9c78b2bSJens Axboe void bio_trim(struct bio *bio, int offset, int size) 1813f9c78b2bSJens Axboe { 1814f9c78b2bSJens Axboe /* 'bio' is a cloned bio which we need to trim to match 1815f9c78b2bSJens Axboe * the given offset and size. 1816f9c78b2bSJens Axboe */ 1817f9c78b2bSJens Axboe 1818f9c78b2bSJens Axboe size <<= 9; 1819f9c78b2bSJens Axboe if (offset == 0 && size == bio->bi_iter.bi_size) 1820f9c78b2bSJens Axboe return; 1821f9c78b2bSJens Axboe 1822b7c44ed9SJens Axboe bio_clear_flag(bio, BIO_SEG_VALID); 1823f9c78b2bSJens Axboe 1824f9c78b2bSJens Axboe bio_advance(bio, offset << 9); 1825f9c78b2bSJens Axboe 1826f9c78b2bSJens Axboe bio->bi_iter.bi_size = size; 1827f9c78b2bSJens Axboe } 1828f9c78b2bSJens Axboe EXPORT_SYMBOL_GPL(bio_trim); 1829f9c78b2bSJens Axboe 1830f9c78b2bSJens Axboe /* 1831f9c78b2bSJens Axboe * create memory pools for biovec's in a bio_set. 1832f9c78b2bSJens Axboe * use the global biovec slabs created for general use. 1833f9c78b2bSJens Axboe */ 1834f9c78b2bSJens Axboe mempool_t *biovec_create_pool(int pool_entries) 1835f9c78b2bSJens Axboe { 1836f9c78b2bSJens Axboe struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX; 1837f9c78b2bSJens Axboe 1838f9c78b2bSJens Axboe return mempool_create_slab_pool(pool_entries, bp->slab); 1839f9c78b2bSJens Axboe } 1840f9c78b2bSJens Axboe 1841f9c78b2bSJens Axboe void bioset_free(struct bio_set *bs) 1842f9c78b2bSJens Axboe { 1843f9c78b2bSJens Axboe if (bs->rescue_workqueue) 1844f9c78b2bSJens Axboe destroy_workqueue(bs->rescue_workqueue); 1845f9c78b2bSJens Axboe 1846f9c78b2bSJens Axboe if (bs->bio_pool) 1847f9c78b2bSJens Axboe mempool_destroy(bs->bio_pool); 1848f9c78b2bSJens Axboe 1849f9c78b2bSJens Axboe if (bs->bvec_pool) 1850f9c78b2bSJens Axboe mempool_destroy(bs->bvec_pool); 1851f9c78b2bSJens Axboe 1852f9c78b2bSJens Axboe bioset_integrity_free(bs); 1853f9c78b2bSJens Axboe bio_put_slab(bs); 1854f9c78b2bSJens Axboe 1855f9c78b2bSJens Axboe kfree(bs); 1856f9c78b2bSJens Axboe } 1857f9c78b2bSJens Axboe EXPORT_SYMBOL(bioset_free); 1858f9c78b2bSJens Axboe 1859d8f429e1SJunichi Nomura static struct bio_set *__bioset_create(unsigned int pool_size, 1860d8f429e1SJunichi Nomura unsigned int front_pad, 1861d8f429e1SJunichi Nomura bool create_bvec_pool) 1862f9c78b2bSJens Axboe { 1863f9c78b2bSJens Axboe unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec); 1864f9c78b2bSJens Axboe struct bio_set *bs; 1865f9c78b2bSJens Axboe 1866f9c78b2bSJens Axboe bs = kzalloc(sizeof(*bs), GFP_KERNEL); 1867f9c78b2bSJens Axboe if (!bs) 1868f9c78b2bSJens Axboe return NULL; 1869f9c78b2bSJens Axboe 1870f9c78b2bSJens Axboe bs->front_pad = front_pad; 1871f9c78b2bSJens Axboe 1872f9c78b2bSJens Axboe spin_lock_init(&bs->rescue_lock); 1873f9c78b2bSJens Axboe bio_list_init(&bs->rescue_list); 1874f9c78b2bSJens Axboe INIT_WORK(&bs->rescue_work, bio_alloc_rescue); 1875f9c78b2bSJens Axboe 1876f9c78b2bSJens Axboe bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad); 1877f9c78b2bSJens Axboe if (!bs->bio_slab) { 1878f9c78b2bSJens Axboe kfree(bs); 1879f9c78b2bSJens Axboe return NULL; 1880f9c78b2bSJens Axboe } 1881f9c78b2bSJens Axboe 1882f9c78b2bSJens Axboe bs->bio_pool = mempool_create_slab_pool(pool_size, bs->bio_slab); 1883f9c78b2bSJens Axboe if (!bs->bio_pool) 1884f9c78b2bSJens Axboe goto bad; 1885f9c78b2bSJens Axboe 1886d8f429e1SJunichi Nomura if (create_bvec_pool) { 1887f9c78b2bSJens Axboe bs->bvec_pool = biovec_create_pool(pool_size); 1888f9c78b2bSJens Axboe if (!bs->bvec_pool) 1889f9c78b2bSJens Axboe goto bad; 1890d8f429e1SJunichi Nomura } 1891f9c78b2bSJens Axboe 1892f9c78b2bSJens Axboe bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0); 1893f9c78b2bSJens Axboe if (!bs->rescue_workqueue) 1894f9c78b2bSJens Axboe goto bad; 1895f9c78b2bSJens Axboe 1896f9c78b2bSJens Axboe return bs; 1897f9c78b2bSJens Axboe bad: 1898f9c78b2bSJens Axboe bioset_free(bs); 1899f9c78b2bSJens Axboe return NULL; 1900f9c78b2bSJens Axboe } 1901d8f429e1SJunichi Nomura 1902d8f429e1SJunichi Nomura /** 1903d8f429e1SJunichi Nomura * bioset_create - Create a bio_set 1904d8f429e1SJunichi Nomura * @pool_size: Number of bio and bio_vecs to cache in the mempool 1905d8f429e1SJunichi Nomura * @front_pad: Number of bytes to allocate in front of the returned bio 1906d8f429e1SJunichi Nomura * 1907d8f429e1SJunichi Nomura * Description: 1908d8f429e1SJunichi Nomura * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller 1909d8f429e1SJunichi Nomura * to ask for a number of bytes to be allocated in front of the bio. 1910d8f429e1SJunichi Nomura * Front pad allocation is useful for embedding the bio inside 1911d8f429e1SJunichi Nomura * another structure, to avoid allocating extra data to go with the bio. 1912d8f429e1SJunichi Nomura * Note that the bio must be embedded at the END of that structure always, 1913d8f429e1SJunichi Nomura * or things will break badly. 1914d8f429e1SJunichi Nomura */ 1915d8f429e1SJunichi Nomura struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad) 1916d8f429e1SJunichi Nomura { 1917d8f429e1SJunichi Nomura return __bioset_create(pool_size, front_pad, true); 1918d8f429e1SJunichi Nomura } 1919f9c78b2bSJens Axboe EXPORT_SYMBOL(bioset_create); 1920f9c78b2bSJens Axboe 1921d8f429e1SJunichi Nomura /** 1922d8f429e1SJunichi Nomura * bioset_create_nobvec - Create a bio_set without bio_vec mempool 1923d8f429e1SJunichi Nomura * @pool_size: Number of bio to cache in the mempool 1924d8f429e1SJunichi Nomura * @front_pad: Number of bytes to allocate in front of the returned bio 1925d8f429e1SJunichi Nomura * 1926d8f429e1SJunichi Nomura * Description: 1927d8f429e1SJunichi Nomura * Same functionality as bioset_create() except that mempool is not 1928d8f429e1SJunichi Nomura * created for bio_vecs. Saving some memory for bio_clone_fast() users. 1929d8f429e1SJunichi Nomura */ 1930d8f429e1SJunichi Nomura struct bio_set *bioset_create_nobvec(unsigned int pool_size, unsigned int front_pad) 1931d8f429e1SJunichi Nomura { 1932d8f429e1SJunichi Nomura return __bioset_create(pool_size, front_pad, false); 1933d8f429e1SJunichi Nomura } 1934d8f429e1SJunichi Nomura EXPORT_SYMBOL(bioset_create_nobvec); 1935d8f429e1SJunichi Nomura 1936f9c78b2bSJens Axboe #ifdef CONFIG_BLK_CGROUP 19371d933cf0STejun Heo 19381d933cf0STejun Heo /** 19391d933cf0STejun Heo * bio_associate_blkcg - associate a bio with the specified blkcg 19401d933cf0STejun Heo * @bio: target bio 19411d933cf0STejun Heo * @blkcg_css: css of the blkcg to associate 19421d933cf0STejun Heo * 19431d933cf0STejun Heo * Associate @bio with the blkcg specified by @blkcg_css. Block layer will 19441d933cf0STejun Heo * treat @bio as if it were issued by a task which belongs to the blkcg. 19451d933cf0STejun Heo * 19461d933cf0STejun Heo * This function takes an extra reference of @blkcg_css which will be put 19471d933cf0STejun Heo * when @bio is released. The caller must own @bio and is responsible for 19481d933cf0STejun Heo * synchronizing calls to this function. 19491d933cf0STejun Heo */ 19501d933cf0STejun Heo int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) 19511d933cf0STejun Heo { 19521d933cf0STejun Heo if (unlikely(bio->bi_css)) 19531d933cf0STejun Heo return -EBUSY; 19541d933cf0STejun Heo css_get(blkcg_css); 19551d933cf0STejun Heo bio->bi_css = blkcg_css; 19561d933cf0STejun Heo return 0; 19571d933cf0STejun Heo } 19585aa2a96bSTejun Heo EXPORT_SYMBOL_GPL(bio_associate_blkcg); 19591d933cf0STejun Heo 1960f9c78b2bSJens Axboe /** 1961f9c78b2bSJens Axboe * bio_associate_current - associate a bio with %current 1962f9c78b2bSJens Axboe * @bio: target bio 1963f9c78b2bSJens Axboe * 1964f9c78b2bSJens Axboe * Associate @bio with %current if it hasn't been associated yet. Block 1965f9c78b2bSJens Axboe * layer will treat @bio as if it were issued by %current no matter which 1966f9c78b2bSJens Axboe * task actually issues it. 1967f9c78b2bSJens Axboe * 1968f9c78b2bSJens Axboe * This function takes an extra reference of @task's io_context and blkcg 1969f9c78b2bSJens Axboe * which will be put when @bio is released. The caller must own @bio, 1970f9c78b2bSJens Axboe * ensure %current->io_context exists, and is responsible for synchronizing 1971f9c78b2bSJens Axboe * calls to this function. 1972f9c78b2bSJens Axboe */ 1973f9c78b2bSJens Axboe int bio_associate_current(struct bio *bio) 1974f9c78b2bSJens Axboe { 1975f9c78b2bSJens Axboe struct io_context *ioc; 1976f9c78b2bSJens Axboe 19771d933cf0STejun Heo if (bio->bi_css) 1978f9c78b2bSJens Axboe return -EBUSY; 1979f9c78b2bSJens Axboe 1980f9c78b2bSJens Axboe ioc = current->io_context; 1981f9c78b2bSJens Axboe if (!ioc) 1982f9c78b2bSJens Axboe return -ENOENT; 1983f9c78b2bSJens Axboe 1984f9c78b2bSJens Axboe get_io_context_active(ioc); 1985f9c78b2bSJens Axboe bio->bi_ioc = ioc; 1986c165b3e3STejun Heo bio->bi_css = task_get_css(current, io_cgrp_id); 1987f9c78b2bSJens Axboe return 0; 1988f9c78b2bSJens Axboe } 19895aa2a96bSTejun Heo EXPORT_SYMBOL_GPL(bio_associate_current); 1990f9c78b2bSJens Axboe 1991f9c78b2bSJens Axboe /** 1992f9c78b2bSJens Axboe * bio_disassociate_task - undo bio_associate_current() 1993f9c78b2bSJens Axboe * @bio: target bio 1994f9c78b2bSJens Axboe */ 1995f9c78b2bSJens Axboe void bio_disassociate_task(struct bio *bio) 1996f9c78b2bSJens Axboe { 1997f9c78b2bSJens Axboe if (bio->bi_ioc) { 1998f9c78b2bSJens Axboe put_io_context(bio->bi_ioc); 1999f9c78b2bSJens Axboe bio->bi_ioc = NULL; 2000f9c78b2bSJens Axboe } 2001f9c78b2bSJens Axboe if (bio->bi_css) { 2002f9c78b2bSJens Axboe css_put(bio->bi_css); 2003f9c78b2bSJens Axboe bio->bi_css = NULL; 2004f9c78b2bSJens Axboe } 2005f9c78b2bSJens Axboe } 2006f9c78b2bSJens Axboe 2007f9c78b2bSJens Axboe #endif /* CONFIG_BLK_CGROUP */ 2008f9c78b2bSJens Axboe 2009f9c78b2bSJens Axboe static void __init biovec_init_slabs(void) 2010f9c78b2bSJens Axboe { 2011f9c78b2bSJens Axboe int i; 2012f9c78b2bSJens Axboe 2013f9c78b2bSJens Axboe for (i = 0; i < BIOVEC_NR_POOLS; i++) { 2014f9c78b2bSJens Axboe int size; 2015f9c78b2bSJens Axboe struct biovec_slab *bvs = bvec_slabs + i; 2016f9c78b2bSJens Axboe 2017f9c78b2bSJens Axboe if (bvs->nr_vecs <= BIO_INLINE_VECS) { 2018f9c78b2bSJens Axboe bvs->slab = NULL; 2019f9c78b2bSJens Axboe continue; 2020f9c78b2bSJens Axboe } 2021f9c78b2bSJens Axboe 2022f9c78b2bSJens Axboe size = bvs->nr_vecs * sizeof(struct bio_vec); 2023f9c78b2bSJens Axboe bvs->slab = kmem_cache_create(bvs->name, size, 0, 2024f9c78b2bSJens Axboe SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 2025f9c78b2bSJens Axboe } 2026f9c78b2bSJens Axboe } 2027f9c78b2bSJens Axboe 2028f9c78b2bSJens Axboe static int __init init_bio(void) 2029f9c78b2bSJens Axboe { 2030f9c78b2bSJens Axboe bio_slab_max = 2; 2031f9c78b2bSJens Axboe bio_slab_nr = 0; 2032f9c78b2bSJens Axboe bio_slabs = kzalloc(bio_slab_max * sizeof(struct bio_slab), GFP_KERNEL); 2033f9c78b2bSJens Axboe if (!bio_slabs) 2034f9c78b2bSJens Axboe panic("bio: can't allocate bios\n"); 2035f9c78b2bSJens Axboe 2036f9c78b2bSJens Axboe bio_integrity_init(); 2037f9c78b2bSJens Axboe biovec_init_slabs(); 2038f9c78b2bSJens Axboe 2039f9c78b2bSJens Axboe fs_bio_set = bioset_create(BIO_POOL_SIZE, 0); 2040f9c78b2bSJens Axboe if (!fs_bio_set) 2041f9c78b2bSJens Axboe panic("bio: can't allocate bios\n"); 2042f9c78b2bSJens Axboe 2043f9c78b2bSJens Axboe if (bioset_integrity_create(fs_bio_set, BIO_POOL_SIZE)) 2044f9c78b2bSJens Axboe panic("bio: can't create integrity pool\n"); 2045f9c78b2bSJens Axboe 2046f9c78b2bSJens Axboe return 0; 2047f9c78b2bSJens Axboe } 2048f9c78b2bSJens Axboe subsys_initcall(init_bio); 2049