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> 3108e18eabSJosef Bacik #include <linux/blk-cgroup.h> 32f9c78b2bSJens Axboe 33f9c78b2bSJens Axboe #include <trace/events/block.h> 349e234eeaSShaohua Li #include "blk.h" 3567b42d0bSJosef Bacik #include "blk-rq-qos.h" 36f9c78b2bSJens Axboe 37f9c78b2bSJens Axboe /* 38f9c78b2bSJens Axboe * Test patch to inline a certain number of bi_io_vec's inside the bio 39f9c78b2bSJens Axboe * itself, to shrink a bio data allocation from two mempool calls to one 40f9c78b2bSJens Axboe */ 41f9c78b2bSJens Axboe #define BIO_INLINE_VECS 4 42f9c78b2bSJens Axboe 43f9c78b2bSJens Axboe /* 44f9c78b2bSJens Axboe * if you change this list, also change bvec_alloc or things will 45f9c78b2bSJens Axboe * break badly! cannot be bigger than what you can fit into an 46f9c78b2bSJens Axboe * unsigned short 47f9c78b2bSJens Axboe */ 48bd5c4facSMikulas Patocka #define BV(x, n) { .nr_vecs = x, .name = "biovec-"#n } 49ed996a52SChristoph Hellwig static struct biovec_slab bvec_slabs[BVEC_POOL_NR] __read_mostly = { 50bd5c4facSMikulas Patocka BV(1, 1), BV(4, 4), BV(16, 16), BV(64, 64), BV(128, 128), BV(BIO_MAX_PAGES, max), 51f9c78b2bSJens Axboe }; 52f9c78b2bSJens Axboe #undef BV 53f9c78b2bSJens Axboe 54f9c78b2bSJens Axboe /* 55f9c78b2bSJens Axboe * fs_bio_set is the bio_set containing bio and iovec memory pools used by 56f9c78b2bSJens Axboe * IO code that does not need private memory pools. 57f9c78b2bSJens Axboe */ 58f4f8154aSKent Overstreet struct bio_set fs_bio_set; 59f9c78b2bSJens Axboe EXPORT_SYMBOL(fs_bio_set); 60f9c78b2bSJens Axboe 61f9c78b2bSJens Axboe /* 62f9c78b2bSJens Axboe * Our slab pool management 63f9c78b2bSJens Axboe */ 64f9c78b2bSJens Axboe struct bio_slab { 65f9c78b2bSJens Axboe struct kmem_cache *slab; 66f9c78b2bSJens Axboe unsigned int slab_ref; 67f9c78b2bSJens Axboe unsigned int slab_size; 68f9c78b2bSJens Axboe char name[8]; 69f9c78b2bSJens Axboe }; 70f9c78b2bSJens Axboe static DEFINE_MUTEX(bio_slab_lock); 71f9c78b2bSJens Axboe static struct bio_slab *bio_slabs; 72f9c78b2bSJens Axboe static unsigned int bio_slab_nr, bio_slab_max; 73f9c78b2bSJens Axboe 74f9c78b2bSJens Axboe static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size) 75f9c78b2bSJens Axboe { 76f9c78b2bSJens Axboe unsigned int sz = sizeof(struct bio) + extra_size; 77f9c78b2bSJens Axboe struct kmem_cache *slab = NULL; 78f9c78b2bSJens Axboe struct bio_slab *bslab, *new_bio_slabs; 79f9c78b2bSJens Axboe unsigned int new_bio_slab_max; 80f9c78b2bSJens Axboe unsigned int i, entry = -1; 81f9c78b2bSJens Axboe 82f9c78b2bSJens Axboe mutex_lock(&bio_slab_lock); 83f9c78b2bSJens Axboe 84f9c78b2bSJens Axboe i = 0; 85f9c78b2bSJens Axboe while (i < bio_slab_nr) { 86f9c78b2bSJens Axboe bslab = &bio_slabs[i]; 87f9c78b2bSJens Axboe 88f9c78b2bSJens Axboe if (!bslab->slab && entry == -1) 89f9c78b2bSJens Axboe entry = i; 90f9c78b2bSJens Axboe else if (bslab->slab_size == sz) { 91f9c78b2bSJens Axboe slab = bslab->slab; 92f9c78b2bSJens Axboe bslab->slab_ref++; 93f9c78b2bSJens Axboe break; 94f9c78b2bSJens Axboe } 95f9c78b2bSJens Axboe i++; 96f9c78b2bSJens Axboe } 97f9c78b2bSJens Axboe 98f9c78b2bSJens Axboe if (slab) 99f9c78b2bSJens Axboe goto out_unlock; 100f9c78b2bSJens Axboe 101f9c78b2bSJens Axboe if (bio_slab_nr == bio_slab_max && entry == -1) { 102f9c78b2bSJens Axboe new_bio_slab_max = bio_slab_max << 1; 103f9c78b2bSJens Axboe new_bio_slabs = krealloc(bio_slabs, 104f9c78b2bSJens Axboe new_bio_slab_max * sizeof(struct bio_slab), 105f9c78b2bSJens Axboe GFP_KERNEL); 106f9c78b2bSJens Axboe if (!new_bio_slabs) 107f9c78b2bSJens Axboe goto out_unlock; 108f9c78b2bSJens Axboe bio_slab_max = new_bio_slab_max; 109f9c78b2bSJens Axboe bio_slabs = new_bio_slabs; 110f9c78b2bSJens Axboe } 111f9c78b2bSJens Axboe if (entry == -1) 112f9c78b2bSJens Axboe entry = bio_slab_nr++; 113f9c78b2bSJens Axboe 114f9c78b2bSJens Axboe bslab = &bio_slabs[entry]; 115f9c78b2bSJens Axboe 116f9c78b2bSJens Axboe snprintf(bslab->name, sizeof(bslab->name), "bio-%d", entry); 1176a241483SMikulas Patocka slab = kmem_cache_create(bslab->name, sz, ARCH_KMALLOC_MINALIGN, 1186a241483SMikulas Patocka SLAB_HWCACHE_ALIGN, NULL); 119f9c78b2bSJens Axboe if (!slab) 120f9c78b2bSJens Axboe goto out_unlock; 121f9c78b2bSJens Axboe 122f9c78b2bSJens Axboe bslab->slab = slab; 123f9c78b2bSJens Axboe bslab->slab_ref = 1; 124f9c78b2bSJens Axboe bslab->slab_size = sz; 125f9c78b2bSJens Axboe out_unlock: 126f9c78b2bSJens Axboe mutex_unlock(&bio_slab_lock); 127f9c78b2bSJens Axboe return slab; 128f9c78b2bSJens Axboe } 129f9c78b2bSJens Axboe 130f9c78b2bSJens Axboe static void bio_put_slab(struct bio_set *bs) 131f9c78b2bSJens Axboe { 132f9c78b2bSJens Axboe struct bio_slab *bslab = NULL; 133f9c78b2bSJens Axboe unsigned int i; 134f9c78b2bSJens Axboe 135f9c78b2bSJens Axboe mutex_lock(&bio_slab_lock); 136f9c78b2bSJens Axboe 137f9c78b2bSJens Axboe for (i = 0; i < bio_slab_nr; i++) { 138f9c78b2bSJens Axboe if (bs->bio_slab == bio_slabs[i].slab) { 139f9c78b2bSJens Axboe bslab = &bio_slabs[i]; 140f9c78b2bSJens Axboe break; 141f9c78b2bSJens Axboe } 142f9c78b2bSJens Axboe } 143f9c78b2bSJens Axboe 144f9c78b2bSJens Axboe if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n")) 145f9c78b2bSJens Axboe goto out; 146f9c78b2bSJens Axboe 147f9c78b2bSJens Axboe WARN_ON(!bslab->slab_ref); 148f9c78b2bSJens Axboe 149f9c78b2bSJens Axboe if (--bslab->slab_ref) 150f9c78b2bSJens Axboe goto out; 151f9c78b2bSJens Axboe 152f9c78b2bSJens Axboe kmem_cache_destroy(bslab->slab); 153f9c78b2bSJens Axboe bslab->slab = NULL; 154f9c78b2bSJens Axboe 155f9c78b2bSJens Axboe out: 156f9c78b2bSJens Axboe mutex_unlock(&bio_slab_lock); 157f9c78b2bSJens Axboe } 158f9c78b2bSJens Axboe 159f9c78b2bSJens Axboe unsigned int bvec_nr_vecs(unsigned short idx) 160f9c78b2bSJens Axboe { 161d6c02a9bSGreg Edwards return bvec_slabs[--idx].nr_vecs; 162f9c78b2bSJens Axboe } 163f9c78b2bSJens Axboe 164f9c78b2bSJens Axboe void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned int idx) 165f9c78b2bSJens Axboe { 166ed996a52SChristoph Hellwig if (!idx) 167ed996a52SChristoph Hellwig return; 168ed996a52SChristoph Hellwig idx--; 169f9c78b2bSJens Axboe 170ed996a52SChristoph Hellwig BIO_BUG_ON(idx >= BVEC_POOL_NR); 171ed996a52SChristoph Hellwig 172ed996a52SChristoph Hellwig if (idx == BVEC_POOL_MAX) { 173f9c78b2bSJens Axboe mempool_free(bv, pool); 174ed996a52SChristoph Hellwig } else { 175f9c78b2bSJens Axboe struct biovec_slab *bvs = bvec_slabs + idx; 176f9c78b2bSJens Axboe 177f9c78b2bSJens Axboe kmem_cache_free(bvs->slab, bv); 178f9c78b2bSJens Axboe } 179f9c78b2bSJens Axboe } 180f9c78b2bSJens Axboe 181f9c78b2bSJens Axboe struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx, 182f9c78b2bSJens Axboe mempool_t *pool) 183f9c78b2bSJens Axboe { 184f9c78b2bSJens Axboe struct bio_vec *bvl; 185f9c78b2bSJens Axboe 186f9c78b2bSJens Axboe /* 187f9c78b2bSJens Axboe * see comment near bvec_array define! 188f9c78b2bSJens Axboe */ 189f9c78b2bSJens Axboe switch (nr) { 190f9c78b2bSJens Axboe case 1: 191f9c78b2bSJens Axboe *idx = 0; 192f9c78b2bSJens Axboe break; 193f9c78b2bSJens Axboe case 2 ... 4: 194f9c78b2bSJens Axboe *idx = 1; 195f9c78b2bSJens Axboe break; 196f9c78b2bSJens Axboe case 5 ... 16: 197f9c78b2bSJens Axboe *idx = 2; 198f9c78b2bSJens Axboe break; 199f9c78b2bSJens Axboe case 17 ... 64: 200f9c78b2bSJens Axboe *idx = 3; 201f9c78b2bSJens Axboe break; 202f9c78b2bSJens Axboe case 65 ... 128: 203f9c78b2bSJens Axboe *idx = 4; 204f9c78b2bSJens Axboe break; 205f9c78b2bSJens Axboe case 129 ... BIO_MAX_PAGES: 206f9c78b2bSJens Axboe *idx = 5; 207f9c78b2bSJens Axboe break; 208f9c78b2bSJens Axboe default: 209f9c78b2bSJens Axboe return NULL; 210f9c78b2bSJens Axboe } 211f9c78b2bSJens Axboe 212f9c78b2bSJens Axboe /* 213f9c78b2bSJens Axboe * idx now points to the pool we want to allocate from. only the 214f9c78b2bSJens Axboe * 1-vec entry pool is mempool backed. 215f9c78b2bSJens Axboe */ 216ed996a52SChristoph Hellwig if (*idx == BVEC_POOL_MAX) { 217f9c78b2bSJens Axboe fallback: 218f9c78b2bSJens Axboe bvl = mempool_alloc(pool, gfp_mask); 219f9c78b2bSJens Axboe } else { 220f9c78b2bSJens Axboe struct biovec_slab *bvs = bvec_slabs + *idx; 221d0164adcSMel Gorman gfp_t __gfp_mask = gfp_mask & ~(__GFP_DIRECT_RECLAIM | __GFP_IO); 222f9c78b2bSJens Axboe 223f9c78b2bSJens Axboe /* 224f9c78b2bSJens Axboe * Make this allocation restricted and don't dump info on 225f9c78b2bSJens Axboe * allocation failures, since we'll fallback to the mempool 226f9c78b2bSJens Axboe * in case of failure. 227f9c78b2bSJens Axboe */ 228f9c78b2bSJens Axboe __gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; 229f9c78b2bSJens Axboe 230f9c78b2bSJens Axboe /* 231d0164adcSMel Gorman * Try a slab allocation. If this fails and __GFP_DIRECT_RECLAIM 232f9c78b2bSJens Axboe * is set, retry with the 1-entry mempool 233f9c78b2bSJens Axboe */ 234f9c78b2bSJens Axboe bvl = kmem_cache_alloc(bvs->slab, __gfp_mask); 235d0164adcSMel Gorman if (unlikely(!bvl && (gfp_mask & __GFP_DIRECT_RECLAIM))) { 236ed996a52SChristoph Hellwig *idx = BVEC_POOL_MAX; 237f9c78b2bSJens Axboe goto fallback; 238f9c78b2bSJens Axboe } 239f9c78b2bSJens Axboe } 240f9c78b2bSJens Axboe 241ed996a52SChristoph Hellwig (*idx)++; 242f9c78b2bSJens Axboe return bvl; 243f9c78b2bSJens Axboe } 244f9c78b2bSJens Axboe 2459ae3b3f5SJens Axboe void bio_uninit(struct bio *bio) 246f9c78b2bSJens Axboe { 247f9c78b2bSJens Axboe bio_disassociate_task(bio); 248f9c78b2bSJens Axboe } 2499ae3b3f5SJens Axboe EXPORT_SYMBOL(bio_uninit); 250f9c78b2bSJens Axboe 251f9c78b2bSJens Axboe static void bio_free(struct bio *bio) 252f9c78b2bSJens Axboe { 253f9c78b2bSJens Axboe struct bio_set *bs = bio->bi_pool; 254f9c78b2bSJens Axboe void *p; 255f9c78b2bSJens Axboe 2569ae3b3f5SJens Axboe bio_uninit(bio); 257f9c78b2bSJens Axboe 258f9c78b2bSJens Axboe if (bs) { 2598aa6ba2fSKent Overstreet bvec_free(&bs->bvec_pool, bio->bi_io_vec, BVEC_POOL_IDX(bio)); 260f9c78b2bSJens Axboe 261f9c78b2bSJens Axboe /* 262f9c78b2bSJens Axboe * If we have front padding, adjust the bio pointer before freeing 263f9c78b2bSJens Axboe */ 264f9c78b2bSJens Axboe p = bio; 265f9c78b2bSJens Axboe p -= bs->front_pad; 266f9c78b2bSJens Axboe 2678aa6ba2fSKent Overstreet mempool_free(p, &bs->bio_pool); 268f9c78b2bSJens Axboe } else { 269f9c78b2bSJens Axboe /* Bio was allocated by bio_kmalloc() */ 270f9c78b2bSJens Axboe kfree(bio); 271f9c78b2bSJens Axboe } 272f9c78b2bSJens Axboe } 273f9c78b2bSJens Axboe 2749ae3b3f5SJens Axboe /* 2759ae3b3f5SJens Axboe * Users of this function have their own bio allocation. Subsequently, 2769ae3b3f5SJens Axboe * they must remember to pair any call to bio_init() with bio_uninit() 2779ae3b3f5SJens Axboe * when IO has completed, or when the bio is released. 2789ae3b3f5SJens Axboe */ 2793a83f467SMing Lei void bio_init(struct bio *bio, struct bio_vec *table, 2803a83f467SMing Lei unsigned short max_vecs) 281f9c78b2bSJens Axboe { 282f9c78b2bSJens Axboe memset(bio, 0, sizeof(*bio)); 283c4cf5261SJens Axboe atomic_set(&bio->__bi_remaining, 1); 284dac56212SJens Axboe atomic_set(&bio->__bi_cnt, 1); 2853a83f467SMing Lei 2863a83f467SMing Lei bio->bi_io_vec = table; 2873a83f467SMing Lei bio->bi_max_vecs = max_vecs; 288f9c78b2bSJens Axboe } 289f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_init); 290f9c78b2bSJens Axboe 291f9c78b2bSJens Axboe /** 292f9c78b2bSJens Axboe * bio_reset - reinitialize a bio 293f9c78b2bSJens Axboe * @bio: bio to reset 294f9c78b2bSJens Axboe * 295f9c78b2bSJens Axboe * Description: 296f9c78b2bSJens Axboe * After calling bio_reset(), @bio will be in the same state as a freshly 297f9c78b2bSJens Axboe * allocated bio returned bio bio_alloc_bioset() - the only fields that are 298f9c78b2bSJens Axboe * preserved are the ones that are initialized by bio_alloc_bioset(). See 299f9c78b2bSJens Axboe * comment in struct bio. 300f9c78b2bSJens Axboe */ 301f9c78b2bSJens Axboe void bio_reset(struct bio *bio) 302f9c78b2bSJens Axboe { 303f9c78b2bSJens Axboe unsigned long flags = bio->bi_flags & (~0UL << BIO_RESET_BITS); 304f9c78b2bSJens Axboe 3059ae3b3f5SJens Axboe bio_uninit(bio); 306f9c78b2bSJens Axboe 307f9c78b2bSJens Axboe memset(bio, 0, BIO_RESET_BYTES); 3084246a0b6SChristoph Hellwig bio->bi_flags = flags; 309c4cf5261SJens Axboe atomic_set(&bio->__bi_remaining, 1); 310f9c78b2bSJens Axboe } 311f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_reset); 312f9c78b2bSJens Axboe 31338f8baaeSChristoph Hellwig static struct bio *__bio_chain_endio(struct bio *bio) 314f9c78b2bSJens Axboe { 3154246a0b6SChristoph Hellwig struct bio *parent = bio->bi_private; 3164246a0b6SChristoph Hellwig 3174e4cbee9SChristoph Hellwig if (!parent->bi_status) 3184e4cbee9SChristoph Hellwig parent->bi_status = bio->bi_status; 319f9c78b2bSJens Axboe bio_put(bio); 32038f8baaeSChristoph Hellwig return parent; 32138f8baaeSChristoph Hellwig } 32238f8baaeSChristoph Hellwig 32338f8baaeSChristoph Hellwig static void bio_chain_endio(struct bio *bio) 32438f8baaeSChristoph Hellwig { 32538f8baaeSChristoph Hellwig bio_endio(__bio_chain_endio(bio)); 326f9c78b2bSJens Axboe } 327f9c78b2bSJens Axboe 328f9c78b2bSJens Axboe /** 329f9c78b2bSJens Axboe * bio_chain - chain bio completions 330f9c78b2bSJens Axboe * @bio: the target bio 331f9c78b2bSJens Axboe * @parent: the @bio's parent bio 332f9c78b2bSJens Axboe * 333f9c78b2bSJens Axboe * The caller won't have a bi_end_io called when @bio completes - instead, 334f9c78b2bSJens Axboe * @parent's bi_end_io won't be called until both @parent and @bio have 335f9c78b2bSJens Axboe * completed; the chained bio will also be freed when it completes. 336f9c78b2bSJens Axboe * 337f9c78b2bSJens Axboe * The caller must not set bi_private or bi_end_io in @bio. 338f9c78b2bSJens Axboe */ 339f9c78b2bSJens Axboe void bio_chain(struct bio *bio, struct bio *parent) 340f9c78b2bSJens Axboe { 341f9c78b2bSJens Axboe BUG_ON(bio->bi_private || bio->bi_end_io); 342f9c78b2bSJens Axboe 343f9c78b2bSJens Axboe bio->bi_private = parent; 344f9c78b2bSJens Axboe bio->bi_end_io = bio_chain_endio; 345c4cf5261SJens Axboe bio_inc_remaining(parent); 346f9c78b2bSJens Axboe } 347f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_chain); 348f9c78b2bSJens Axboe 349f9c78b2bSJens Axboe static void bio_alloc_rescue(struct work_struct *work) 350f9c78b2bSJens Axboe { 351f9c78b2bSJens Axboe struct bio_set *bs = container_of(work, struct bio_set, rescue_work); 352f9c78b2bSJens Axboe struct bio *bio; 353f9c78b2bSJens Axboe 354f9c78b2bSJens Axboe while (1) { 355f9c78b2bSJens Axboe spin_lock(&bs->rescue_lock); 356f9c78b2bSJens Axboe bio = bio_list_pop(&bs->rescue_list); 357f9c78b2bSJens Axboe spin_unlock(&bs->rescue_lock); 358f9c78b2bSJens Axboe 359f9c78b2bSJens Axboe if (!bio) 360f9c78b2bSJens Axboe break; 361f9c78b2bSJens Axboe 362f9c78b2bSJens Axboe generic_make_request(bio); 363f9c78b2bSJens Axboe } 364f9c78b2bSJens Axboe } 365f9c78b2bSJens Axboe 366f9c78b2bSJens Axboe static void punt_bios_to_rescuer(struct bio_set *bs) 367f9c78b2bSJens Axboe { 368f9c78b2bSJens Axboe struct bio_list punt, nopunt; 369f9c78b2bSJens Axboe struct bio *bio; 370f9c78b2bSJens Axboe 37147e0fb46SNeilBrown if (WARN_ON_ONCE(!bs->rescue_workqueue)) 37247e0fb46SNeilBrown return; 373f9c78b2bSJens Axboe /* 374f9c78b2bSJens Axboe * In order to guarantee forward progress we must punt only bios that 375f9c78b2bSJens Axboe * were allocated from this bio_set; otherwise, if there was a bio on 376f9c78b2bSJens Axboe * there for a stacking driver higher up in the stack, processing it 377f9c78b2bSJens Axboe * could require allocating bios from this bio_set, and doing that from 378f9c78b2bSJens Axboe * our own rescuer would be bad. 379f9c78b2bSJens Axboe * 380f9c78b2bSJens Axboe * Since bio lists are singly linked, pop them all instead of trying to 381f9c78b2bSJens Axboe * remove from the middle of the list: 382f9c78b2bSJens Axboe */ 383f9c78b2bSJens Axboe 384f9c78b2bSJens Axboe bio_list_init(&punt); 385f9c78b2bSJens Axboe bio_list_init(&nopunt); 386f9c78b2bSJens Axboe 387f5fe1b51SNeilBrown while ((bio = bio_list_pop(¤t->bio_list[0]))) 388f9c78b2bSJens Axboe bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio); 389f5fe1b51SNeilBrown current->bio_list[0] = nopunt; 390f9c78b2bSJens Axboe 391f5fe1b51SNeilBrown bio_list_init(&nopunt); 392f5fe1b51SNeilBrown while ((bio = bio_list_pop(¤t->bio_list[1]))) 393f5fe1b51SNeilBrown bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio); 394f5fe1b51SNeilBrown current->bio_list[1] = nopunt; 395f9c78b2bSJens Axboe 396f9c78b2bSJens Axboe spin_lock(&bs->rescue_lock); 397f9c78b2bSJens Axboe bio_list_merge(&bs->rescue_list, &punt); 398f9c78b2bSJens Axboe spin_unlock(&bs->rescue_lock); 399f9c78b2bSJens Axboe 400f9c78b2bSJens Axboe queue_work(bs->rescue_workqueue, &bs->rescue_work); 401f9c78b2bSJens Axboe } 402f9c78b2bSJens Axboe 403f9c78b2bSJens Axboe /** 404f9c78b2bSJens Axboe * bio_alloc_bioset - allocate a bio for I/O 405519c8e9fSRandy Dunlap * @gfp_mask: the GFP_* mask given to the slab allocator 406f9c78b2bSJens Axboe * @nr_iovecs: number of iovecs to pre-allocate 407f9c78b2bSJens Axboe * @bs: the bio_set to allocate from. 408f9c78b2bSJens Axboe * 409f9c78b2bSJens Axboe * Description: 410f9c78b2bSJens Axboe * If @bs is NULL, uses kmalloc() to allocate the bio; else the allocation is 411f9c78b2bSJens Axboe * backed by the @bs's mempool. 412f9c78b2bSJens Axboe * 413d0164adcSMel Gorman * When @bs is not NULL, if %__GFP_DIRECT_RECLAIM is set then bio_alloc will 414d0164adcSMel Gorman * always be able to allocate a bio. This is due to the mempool guarantees. 415d0164adcSMel Gorman * To make this work, callers must never allocate more than 1 bio at a time 416d0164adcSMel Gorman * from this pool. Callers that need to allocate more than 1 bio must always 417d0164adcSMel Gorman * submit the previously allocated bio for IO before attempting to allocate 418d0164adcSMel Gorman * a new one. Failure to do so can cause deadlocks under memory pressure. 419f9c78b2bSJens Axboe * 420f9c78b2bSJens Axboe * Note that when running under generic_make_request() (i.e. any block 421f9c78b2bSJens Axboe * driver), bios are not submitted until after you return - see the code in 422f9c78b2bSJens Axboe * generic_make_request() that converts recursion into iteration, to prevent 423f9c78b2bSJens Axboe * stack overflows. 424f9c78b2bSJens Axboe * 425f9c78b2bSJens Axboe * This would normally mean allocating multiple bios under 426f9c78b2bSJens Axboe * generic_make_request() would be susceptible to deadlocks, but we have 427f9c78b2bSJens Axboe * deadlock avoidance code that resubmits any blocked bios from a rescuer 428f9c78b2bSJens Axboe * thread. 429f9c78b2bSJens Axboe * 430f9c78b2bSJens Axboe * However, we do not guarantee forward progress for allocations from other 431f9c78b2bSJens Axboe * mempools. Doing multiple allocations from the same mempool under 432f9c78b2bSJens Axboe * generic_make_request() should be avoided - instead, use bio_set's front_pad 433f9c78b2bSJens Axboe * for per bio allocations. 434f9c78b2bSJens Axboe * 435f9c78b2bSJens Axboe * RETURNS: 436f9c78b2bSJens Axboe * Pointer to new bio on success, NULL on failure. 437f9c78b2bSJens Axboe */ 4387a88fa19SDan Carpenter struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned int nr_iovecs, 4397a88fa19SDan Carpenter struct bio_set *bs) 440f9c78b2bSJens Axboe { 441f9c78b2bSJens Axboe gfp_t saved_gfp = gfp_mask; 442f9c78b2bSJens Axboe unsigned front_pad; 443f9c78b2bSJens Axboe unsigned inline_vecs; 444f9c78b2bSJens Axboe struct bio_vec *bvl = NULL; 445f9c78b2bSJens Axboe struct bio *bio; 446f9c78b2bSJens Axboe void *p; 447f9c78b2bSJens Axboe 448f9c78b2bSJens Axboe if (!bs) { 449f9c78b2bSJens Axboe if (nr_iovecs > UIO_MAXIOV) 450f9c78b2bSJens Axboe return NULL; 451f9c78b2bSJens Axboe 452f9c78b2bSJens Axboe p = kmalloc(sizeof(struct bio) + 453f9c78b2bSJens Axboe nr_iovecs * sizeof(struct bio_vec), 454f9c78b2bSJens Axboe gfp_mask); 455f9c78b2bSJens Axboe front_pad = 0; 456f9c78b2bSJens Axboe inline_vecs = nr_iovecs; 457f9c78b2bSJens Axboe } else { 458d8f429e1SJunichi Nomura /* should not use nobvec bioset for nr_iovecs > 0 */ 4598aa6ba2fSKent Overstreet if (WARN_ON_ONCE(!mempool_initialized(&bs->bvec_pool) && 4608aa6ba2fSKent Overstreet nr_iovecs > 0)) 461d8f429e1SJunichi Nomura return NULL; 462f9c78b2bSJens Axboe /* 463f9c78b2bSJens Axboe * generic_make_request() converts recursion to iteration; this 464f9c78b2bSJens Axboe * means if we're running beneath it, any bios we allocate and 465f9c78b2bSJens Axboe * submit will not be submitted (and thus freed) until after we 466f9c78b2bSJens Axboe * return. 467f9c78b2bSJens Axboe * 468f9c78b2bSJens Axboe * This exposes us to a potential deadlock if we allocate 469f9c78b2bSJens Axboe * multiple bios from the same bio_set() while running 470f9c78b2bSJens Axboe * underneath generic_make_request(). If we were to allocate 471f9c78b2bSJens Axboe * multiple bios (say a stacking block driver that was splitting 472f9c78b2bSJens Axboe * bios), we would deadlock if we exhausted the mempool's 473f9c78b2bSJens Axboe * reserve. 474f9c78b2bSJens Axboe * 475f9c78b2bSJens Axboe * We solve this, and guarantee forward progress, with a rescuer 476f9c78b2bSJens Axboe * workqueue per bio_set. If we go to allocate and there are 477f9c78b2bSJens Axboe * bios on current->bio_list, we first try the allocation 478d0164adcSMel Gorman * without __GFP_DIRECT_RECLAIM; if that fails, we punt those 479d0164adcSMel Gorman * bios we would be blocking to the rescuer workqueue before 480d0164adcSMel Gorman * we retry with the original gfp_flags. 481f9c78b2bSJens Axboe */ 482f9c78b2bSJens Axboe 483f5fe1b51SNeilBrown if (current->bio_list && 484f5fe1b51SNeilBrown (!bio_list_empty(¤t->bio_list[0]) || 48547e0fb46SNeilBrown !bio_list_empty(¤t->bio_list[1])) && 48647e0fb46SNeilBrown bs->rescue_workqueue) 487d0164adcSMel Gorman gfp_mask &= ~__GFP_DIRECT_RECLAIM; 488f9c78b2bSJens Axboe 4898aa6ba2fSKent Overstreet p = mempool_alloc(&bs->bio_pool, gfp_mask); 490f9c78b2bSJens Axboe if (!p && gfp_mask != saved_gfp) { 491f9c78b2bSJens Axboe punt_bios_to_rescuer(bs); 492f9c78b2bSJens Axboe gfp_mask = saved_gfp; 4938aa6ba2fSKent Overstreet p = mempool_alloc(&bs->bio_pool, gfp_mask); 494f9c78b2bSJens Axboe } 495f9c78b2bSJens Axboe 496f9c78b2bSJens Axboe front_pad = bs->front_pad; 497f9c78b2bSJens Axboe inline_vecs = BIO_INLINE_VECS; 498f9c78b2bSJens Axboe } 499f9c78b2bSJens Axboe 500f9c78b2bSJens Axboe if (unlikely(!p)) 501f9c78b2bSJens Axboe return NULL; 502f9c78b2bSJens Axboe 503f9c78b2bSJens Axboe bio = p + front_pad; 5043a83f467SMing Lei bio_init(bio, NULL, 0); 505f9c78b2bSJens Axboe 506f9c78b2bSJens Axboe if (nr_iovecs > inline_vecs) { 507ed996a52SChristoph Hellwig unsigned long idx = 0; 508ed996a52SChristoph Hellwig 5098aa6ba2fSKent Overstreet bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, &bs->bvec_pool); 510f9c78b2bSJens Axboe if (!bvl && gfp_mask != saved_gfp) { 511f9c78b2bSJens Axboe punt_bios_to_rescuer(bs); 512f9c78b2bSJens Axboe gfp_mask = saved_gfp; 5138aa6ba2fSKent Overstreet bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, &bs->bvec_pool); 514f9c78b2bSJens Axboe } 515f9c78b2bSJens Axboe 516f9c78b2bSJens Axboe if (unlikely(!bvl)) 517f9c78b2bSJens Axboe goto err_free; 518f9c78b2bSJens Axboe 519ed996a52SChristoph Hellwig bio->bi_flags |= idx << BVEC_POOL_OFFSET; 520f9c78b2bSJens Axboe } else if (nr_iovecs) { 521f9c78b2bSJens Axboe bvl = bio->bi_inline_vecs; 522f9c78b2bSJens Axboe } 523f9c78b2bSJens Axboe 524f9c78b2bSJens Axboe bio->bi_pool = bs; 525f9c78b2bSJens Axboe bio->bi_max_vecs = nr_iovecs; 526f9c78b2bSJens Axboe bio->bi_io_vec = bvl; 527f9c78b2bSJens Axboe return bio; 528f9c78b2bSJens Axboe 529f9c78b2bSJens Axboe err_free: 5308aa6ba2fSKent Overstreet mempool_free(p, &bs->bio_pool); 531f9c78b2bSJens Axboe return NULL; 532f9c78b2bSJens Axboe } 533f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_alloc_bioset); 534f9c78b2bSJens Axboe 53538a72dacSKent Overstreet void zero_fill_bio_iter(struct bio *bio, struct bvec_iter start) 536f9c78b2bSJens Axboe { 537f9c78b2bSJens Axboe unsigned long flags; 538f9c78b2bSJens Axboe struct bio_vec bv; 539f9c78b2bSJens Axboe struct bvec_iter iter; 540f9c78b2bSJens Axboe 54138a72dacSKent Overstreet __bio_for_each_segment(bv, bio, iter, start) { 542f9c78b2bSJens Axboe char *data = bvec_kmap_irq(&bv, &flags); 543f9c78b2bSJens Axboe memset(data, 0, bv.bv_len); 544f9c78b2bSJens Axboe flush_dcache_page(bv.bv_page); 545f9c78b2bSJens Axboe bvec_kunmap_irq(data, &flags); 546f9c78b2bSJens Axboe } 547f9c78b2bSJens Axboe } 54838a72dacSKent Overstreet EXPORT_SYMBOL(zero_fill_bio_iter); 549f9c78b2bSJens Axboe 550f9c78b2bSJens Axboe /** 551f9c78b2bSJens Axboe * bio_put - release a reference to a bio 552f9c78b2bSJens Axboe * @bio: bio to release reference to 553f9c78b2bSJens Axboe * 554f9c78b2bSJens Axboe * Description: 555f9c78b2bSJens Axboe * Put a reference to a &struct bio, either one you have gotten with 5569b10f6a9SNeilBrown * bio_alloc, bio_get or bio_clone_*. The last put of a bio will free it. 557f9c78b2bSJens Axboe **/ 558f9c78b2bSJens Axboe void bio_put(struct bio *bio) 559f9c78b2bSJens Axboe { 560dac56212SJens Axboe if (!bio_flagged(bio, BIO_REFFED)) 561dac56212SJens Axboe bio_free(bio); 562dac56212SJens Axboe else { 563dac56212SJens Axboe BIO_BUG_ON(!atomic_read(&bio->__bi_cnt)); 564f9c78b2bSJens Axboe 565f9c78b2bSJens Axboe /* 566f9c78b2bSJens Axboe * last put frees it 567f9c78b2bSJens Axboe */ 568dac56212SJens Axboe if (atomic_dec_and_test(&bio->__bi_cnt)) 569f9c78b2bSJens Axboe bio_free(bio); 570f9c78b2bSJens Axboe } 571dac56212SJens Axboe } 572f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_put); 573f9c78b2bSJens Axboe 574f9c78b2bSJens Axboe inline int bio_phys_segments(struct request_queue *q, struct bio *bio) 575f9c78b2bSJens Axboe { 576f9c78b2bSJens Axboe if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) 577f9c78b2bSJens Axboe blk_recount_segments(q, bio); 578f9c78b2bSJens Axboe 579f9c78b2bSJens Axboe return bio->bi_phys_segments; 580f9c78b2bSJens Axboe } 581f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_phys_segments); 582f9c78b2bSJens Axboe 583f9c78b2bSJens Axboe /** 584f9c78b2bSJens Axboe * __bio_clone_fast - clone a bio that shares the original bio's biovec 585f9c78b2bSJens Axboe * @bio: destination bio 586f9c78b2bSJens Axboe * @bio_src: bio to clone 587f9c78b2bSJens Axboe * 588f9c78b2bSJens Axboe * Clone a &bio. Caller will own the returned bio, but not 589f9c78b2bSJens Axboe * the actual data it points to. Reference count of returned 590f9c78b2bSJens Axboe * bio will be one. 591f9c78b2bSJens Axboe * 592f9c78b2bSJens Axboe * Caller must ensure that @bio_src is not freed before @bio. 593f9c78b2bSJens Axboe */ 594f9c78b2bSJens Axboe void __bio_clone_fast(struct bio *bio, struct bio *bio_src) 595f9c78b2bSJens Axboe { 596ed996a52SChristoph Hellwig BUG_ON(bio->bi_pool && BVEC_POOL_IDX(bio)); 597f9c78b2bSJens Axboe 598f9c78b2bSJens Axboe /* 59974d46992SChristoph Hellwig * most users will be overriding ->bi_disk with a new target, 600f9c78b2bSJens Axboe * so we don't set nor calculate new physical/hw segment counts here 601f9c78b2bSJens Axboe */ 60274d46992SChristoph Hellwig bio->bi_disk = bio_src->bi_disk; 60362530ed8SMichael Lyle bio->bi_partno = bio_src->bi_partno; 604b7c44ed9SJens Axboe bio_set_flag(bio, BIO_CLONED); 605111be883SShaohua Li if (bio_flagged(bio_src, BIO_THROTTLED)) 606111be883SShaohua Li bio_set_flag(bio, BIO_THROTTLED); 6071eff9d32SJens Axboe bio->bi_opf = bio_src->bi_opf; 608ca474b73SHannes Reinecke bio->bi_ioprio = bio_src->bi_ioprio; 609cb6934f8SJens Axboe bio->bi_write_hint = bio_src->bi_write_hint; 610f9c78b2bSJens Axboe bio->bi_iter = bio_src->bi_iter; 611f9c78b2bSJens Axboe bio->bi_io_vec = bio_src->bi_io_vec; 61220bd723eSPaolo Valente 613b5f2954dSDennis Zhou bio_clone_blkcg_association(bio, bio_src); 614f9c78b2bSJens Axboe } 615f9c78b2bSJens Axboe EXPORT_SYMBOL(__bio_clone_fast); 616f9c78b2bSJens Axboe 617f9c78b2bSJens Axboe /** 618f9c78b2bSJens Axboe * bio_clone_fast - clone a bio that shares the original bio's biovec 619f9c78b2bSJens Axboe * @bio: bio to clone 620f9c78b2bSJens Axboe * @gfp_mask: allocation priority 621f9c78b2bSJens Axboe * @bs: bio_set to allocate from 622f9c78b2bSJens Axboe * 623f9c78b2bSJens Axboe * Like __bio_clone_fast, only also allocates the returned bio 624f9c78b2bSJens Axboe */ 625f9c78b2bSJens Axboe struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) 626f9c78b2bSJens Axboe { 627f9c78b2bSJens Axboe struct bio *b; 628f9c78b2bSJens Axboe 629f9c78b2bSJens Axboe b = bio_alloc_bioset(gfp_mask, 0, bs); 630f9c78b2bSJens Axboe if (!b) 631f9c78b2bSJens Axboe return NULL; 632f9c78b2bSJens Axboe 633f9c78b2bSJens Axboe __bio_clone_fast(b, bio); 634f9c78b2bSJens Axboe 635f9c78b2bSJens Axboe if (bio_integrity(bio)) { 636f9c78b2bSJens Axboe int ret; 637f9c78b2bSJens Axboe 638f9c78b2bSJens Axboe ret = bio_integrity_clone(b, bio, gfp_mask); 639f9c78b2bSJens Axboe 640f9c78b2bSJens Axboe if (ret < 0) { 641f9c78b2bSJens Axboe bio_put(b); 642f9c78b2bSJens Axboe return NULL; 643f9c78b2bSJens Axboe } 644f9c78b2bSJens Axboe } 645f9c78b2bSJens Axboe 646f9c78b2bSJens Axboe return b; 647f9c78b2bSJens Axboe } 648f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_clone_fast); 649f9c78b2bSJens Axboe 650f4595875SShaohua Li /** 651c66a14d0SKent Overstreet * bio_add_pc_page - attempt to add page to bio 652c66a14d0SKent Overstreet * @q: the target queue 653c66a14d0SKent Overstreet * @bio: destination bio 654c66a14d0SKent Overstreet * @page: page to add 655c66a14d0SKent Overstreet * @len: vec entry length 656c66a14d0SKent Overstreet * @offset: vec entry offset 657f9c78b2bSJens Axboe * 658c66a14d0SKent Overstreet * Attempt to add a page to the bio_vec maplist. This can fail for a 659c66a14d0SKent Overstreet * number of reasons, such as the bio being full or target block device 660c66a14d0SKent Overstreet * limitations. The target block device must allow bio's up to PAGE_SIZE, 661c66a14d0SKent Overstreet * so it is always possible to add a single page to an empty bio. 662c66a14d0SKent Overstreet * 663c66a14d0SKent Overstreet * This should only be used by REQ_PC bios. 664f9c78b2bSJens Axboe */ 665c66a14d0SKent Overstreet int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page 666c66a14d0SKent Overstreet *page, unsigned int len, unsigned int offset) 667f9c78b2bSJens Axboe { 668f9c78b2bSJens Axboe int retried_segments = 0; 669f9c78b2bSJens Axboe struct bio_vec *bvec; 670f9c78b2bSJens Axboe 671f9c78b2bSJens Axboe /* 672f9c78b2bSJens Axboe * cloned bio must not modify vec list 673f9c78b2bSJens Axboe */ 674f9c78b2bSJens Axboe if (unlikely(bio_flagged(bio, BIO_CLONED))) 675f9c78b2bSJens Axboe return 0; 676f9c78b2bSJens Axboe 677c66a14d0SKent Overstreet if (((bio->bi_iter.bi_size + len) >> 9) > queue_max_hw_sectors(q)) 678f9c78b2bSJens Axboe return 0; 679f9c78b2bSJens Axboe 680f9c78b2bSJens Axboe /* 681f9c78b2bSJens Axboe * For filesystems with a blocksize smaller than the pagesize 682f9c78b2bSJens Axboe * we will often be called with the same page as last time and 683f9c78b2bSJens Axboe * a consecutive offset. Optimize this special case. 684f9c78b2bSJens Axboe */ 685f9c78b2bSJens Axboe if (bio->bi_vcnt > 0) { 686f9c78b2bSJens Axboe struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1]; 687f9c78b2bSJens Axboe 688f9c78b2bSJens Axboe if (page == prev->bv_page && 689f9c78b2bSJens Axboe offset == prev->bv_offset + prev->bv_len) { 690f9c78b2bSJens Axboe prev->bv_len += len; 691fcbf6a08SMaurizio Lombardi bio->bi_iter.bi_size += len; 692f9c78b2bSJens Axboe goto done; 693f9c78b2bSJens Axboe } 69466cb45aaSJens Axboe 69566cb45aaSJens Axboe /* 69666cb45aaSJens Axboe * If the queue doesn't support SG gaps and adding this 69766cb45aaSJens Axboe * offset would create a gap, disallow it. 69866cb45aaSJens Axboe */ 69903100aadSKeith Busch if (bvec_gap_to_prev(q, prev, offset)) 70066cb45aaSJens Axboe return 0; 701f9c78b2bSJens Axboe } 702f9c78b2bSJens Axboe 7030aa69fd3SChristoph Hellwig if (bio_full(bio)) 704f9c78b2bSJens Axboe return 0; 705f9c78b2bSJens Axboe 706f9c78b2bSJens Axboe /* 707f9c78b2bSJens Axboe * setup the new entry, we might clear it again later if we 708f9c78b2bSJens Axboe * cannot add the page 709f9c78b2bSJens Axboe */ 710f9c78b2bSJens Axboe bvec = &bio->bi_io_vec[bio->bi_vcnt]; 711f9c78b2bSJens Axboe bvec->bv_page = page; 712f9c78b2bSJens Axboe bvec->bv_len = len; 713f9c78b2bSJens Axboe bvec->bv_offset = offset; 714fcbf6a08SMaurizio Lombardi bio->bi_vcnt++; 715fcbf6a08SMaurizio Lombardi bio->bi_phys_segments++; 716fcbf6a08SMaurizio Lombardi bio->bi_iter.bi_size += len; 717fcbf6a08SMaurizio Lombardi 718fcbf6a08SMaurizio Lombardi /* 719fcbf6a08SMaurizio Lombardi * Perform a recount if the number of segments is greater 720fcbf6a08SMaurizio Lombardi * than queue_max_segments(q). 721fcbf6a08SMaurizio Lombardi */ 722fcbf6a08SMaurizio Lombardi 723fcbf6a08SMaurizio Lombardi while (bio->bi_phys_segments > queue_max_segments(q)) { 724fcbf6a08SMaurizio Lombardi 725fcbf6a08SMaurizio Lombardi if (retried_segments) 726fcbf6a08SMaurizio Lombardi goto failed; 727fcbf6a08SMaurizio Lombardi 728fcbf6a08SMaurizio Lombardi retried_segments = 1; 729fcbf6a08SMaurizio Lombardi blk_recount_segments(q, bio); 730fcbf6a08SMaurizio Lombardi } 731f9c78b2bSJens Axboe 732f9c78b2bSJens Axboe /* If we may be able to merge these biovecs, force a recount */ 7333dccdae5SChristoph Hellwig if (bio->bi_vcnt > 1 && biovec_phys_mergeable(q, bvec - 1, bvec)) 734b7c44ed9SJens Axboe bio_clear_flag(bio, BIO_SEG_VALID); 735f9c78b2bSJens Axboe 736f9c78b2bSJens Axboe done: 737f9c78b2bSJens Axboe return len; 738fcbf6a08SMaurizio Lombardi 739fcbf6a08SMaurizio Lombardi failed: 740fcbf6a08SMaurizio Lombardi bvec->bv_page = NULL; 741fcbf6a08SMaurizio Lombardi bvec->bv_len = 0; 742fcbf6a08SMaurizio Lombardi bvec->bv_offset = 0; 743fcbf6a08SMaurizio Lombardi bio->bi_vcnt--; 744fcbf6a08SMaurizio Lombardi bio->bi_iter.bi_size -= len; 745fcbf6a08SMaurizio Lombardi blk_recount_segments(q, bio); 746fcbf6a08SMaurizio Lombardi return 0; 747f9c78b2bSJens Axboe } 748f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_add_pc_page); 749f9c78b2bSJens Axboe 750f9c78b2bSJens Axboe /** 7510aa69fd3SChristoph Hellwig * __bio_try_merge_page - try appending data to an existing bvec. 7520aa69fd3SChristoph Hellwig * @bio: destination bio 7530aa69fd3SChristoph Hellwig * @page: page to add 7540aa69fd3SChristoph Hellwig * @len: length of the data to add 7550aa69fd3SChristoph Hellwig * @off: offset of the data in @page 7560aa69fd3SChristoph Hellwig * 7570aa69fd3SChristoph Hellwig * Try to add the data at @page + @off to the last bvec of @bio. This is a 7580aa69fd3SChristoph Hellwig * a useful optimisation for file systems with a block size smaller than the 7590aa69fd3SChristoph Hellwig * page size. 7600aa69fd3SChristoph Hellwig * 7610aa69fd3SChristoph Hellwig * Return %true on success or %false on failure. 7620aa69fd3SChristoph Hellwig */ 7630aa69fd3SChristoph Hellwig bool __bio_try_merge_page(struct bio *bio, struct page *page, 7640aa69fd3SChristoph Hellwig unsigned int len, unsigned int off) 7650aa69fd3SChristoph Hellwig { 7660aa69fd3SChristoph Hellwig if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED))) 7670aa69fd3SChristoph Hellwig return false; 7680aa69fd3SChristoph Hellwig 7690aa69fd3SChristoph Hellwig if (bio->bi_vcnt > 0) { 7700aa69fd3SChristoph Hellwig struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1]; 7710aa69fd3SChristoph Hellwig 7720aa69fd3SChristoph Hellwig if (page == bv->bv_page && off == bv->bv_offset + bv->bv_len) { 7730aa69fd3SChristoph Hellwig bv->bv_len += len; 7740aa69fd3SChristoph Hellwig bio->bi_iter.bi_size += len; 7750aa69fd3SChristoph Hellwig return true; 7760aa69fd3SChristoph Hellwig } 7770aa69fd3SChristoph Hellwig } 7780aa69fd3SChristoph Hellwig return false; 7790aa69fd3SChristoph Hellwig } 7800aa69fd3SChristoph Hellwig EXPORT_SYMBOL_GPL(__bio_try_merge_page); 7810aa69fd3SChristoph Hellwig 7820aa69fd3SChristoph Hellwig /** 7830aa69fd3SChristoph Hellwig * __bio_add_page - add page to a bio in a new segment 7840aa69fd3SChristoph Hellwig * @bio: destination bio 7850aa69fd3SChristoph Hellwig * @page: page to add 7860aa69fd3SChristoph Hellwig * @len: length of the data to add 7870aa69fd3SChristoph Hellwig * @off: offset of the data in @page 7880aa69fd3SChristoph Hellwig * 7890aa69fd3SChristoph Hellwig * Add the data at @page + @off to @bio as a new bvec. The caller must ensure 7900aa69fd3SChristoph Hellwig * that @bio has space for another bvec. 7910aa69fd3SChristoph Hellwig */ 7920aa69fd3SChristoph Hellwig void __bio_add_page(struct bio *bio, struct page *page, 7930aa69fd3SChristoph Hellwig unsigned int len, unsigned int off) 7940aa69fd3SChristoph Hellwig { 7950aa69fd3SChristoph Hellwig struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt]; 7960aa69fd3SChristoph Hellwig 7970aa69fd3SChristoph Hellwig WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)); 7980aa69fd3SChristoph Hellwig WARN_ON_ONCE(bio_full(bio)); 7990aa69fd3SChristoph Hellwig 8000aa69fd3SChristoph Hellwig bv->bv_page = page; 8010aa69fd3SChristoph Hellwig bv->bv_offset = off; 8020aa69fd3SChristoph Hellwig bv->bv_len = len; 8030aa69fd3SChristoph Hellwig 8040aa69fd3SChristoph Hellwig bio->bi_iter.bi_size += len; 8050aa69fd3SChristoph Hellwig bio->bi_vcnt++; 8060aa69fd3SChristoph Hellwig } 8070aa69fd3SChristoph Hellwig EXPORT_SYMBOL_GPL(__bio_add_page); 8080aa69fd3SChristoph Hellwig 8090aa69fd3SChristoph Hellwig /** 810f9c78b2bSJens Axboe * bio_add_page - attempt to add page to bio 811f9c78b2bSJens Axboe * @bio: destination bio 812f9c78b2bSJens Axboe * @page: page to add 813f9c78b2bSJens Axboe * @len: vec entry length 814f9c78b2bSJens Axboe * @offset: vec entry offset 815f9c78b2bSJens Axboe * 816c66a14d0SKent Overstreet * Attempt to add a page to the bio_vec maplist. This will only fail 817c66a14d0SKent Overstreet * if either bio->bi_vcnt == bio->bi_max_vecs or it's a cloned bio. 818f9c78b2bSJens Axboe */ 819c66a14d0SKent Overstreet int bio_add_page(struct bio *bio, struct page *page, 820c66a14d0SKent Overstreet unsigned int len, unsigned int offset) 821f9c78b2bSJens Axboe { 8220aa69fd3SChristoph Hellwig if (!__bio_try_merge_page(bio, page, len, offset)) { 8230aa69fd3SChristoph Hellwig if (bio_full(bio)) 824c66a14d0SKent Overstreet return 0; 8250aa69fd3SChristoph Hellwig __bio_add_page(bio, page, len, offset); 826c66a14d0SKent Overstreet } 827c66a14d0SKent Overstreet return len; 828f9c78b2bSJens Axboe } 829f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_add_page); 830f9c78b2bSJens Axboe 831576ed913SChristoph Hellwig #define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *)) 832576ed913SChristoph Hellwig 8332cefe4dbSKent Overstreet /** 83417d51b10SMartin Wilck * __bio_iov_iter_get_pages - pin user or kernel pages and add them to a bio 8352cefe4dbSKent Overstreet * @bio: bio to add pages to 8362cefe4dbSKent Overstreet * @iter: iov iterator describing the region to be mapped 8372cefe4dbSKent Overstreet * 83817d51b10SMartin Wilck * Pins pages from *iter and appends them to @bio's bvec array. The 8392cefe4dbSKent Overstreet * pages will have to be released using put_page() when done. 84017d51b10SMartin Wilck * For multi-segment *iter, this function only adds pages from the 84117d51b10SMartin Wilck * the next non-empty segment of the iov iterator. 8422cefe4dbSKent Overstreet */ 84317d51b10SMartin Wilck static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 8442cefe4dbSKent Overstreet { 845576ed913SChristoph Hellwig unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt; 846576ed913SChristoph Hellwig unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt; 8472cefe4dbSKent Overstreet struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt; 8482cefe4dbSKent Overstreet struct page **pages = (struct page **)bv; 849576ed913SChristoph Hellwig ssize_t size, left; 850576ed913SChristoph Hellwig unsigned len, i; 851b403ea24SMartin Wilck size_t offset; 852576ed913SChristoph Hellwig 853576ed913SChristoph Hellwig /* 854576ed913SChristoph Hellwig * Move page array up in the allocated memory for the bio vecs as far as 855576ed913SChristoph Hellwig * possible so that we can start filling biovecs from the beginning 856576ed913SChristoph Hellwig * without overwriting the temporary page array. 857576ed913SChristoph Hellwig */ 858576ed913SChristoph Hellwig BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2); 859576ed913SChristoph Hellwig pages += entries_left * (PAGE_PTRS_PER_BVEC - 1); 8602cefe4dbSKent Overstreet 8612cefe4dbSKent Overstreet size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset); 8622cefe4dbSKent Overstreet if (unlikely(size <= 0)) 8632cefe4dbSKent Overstreet return size ? size : -EFAULT; 8642cefe4dbSKent Overstreet 865576ed913SChristoph Hellwig for (left = size, i = 0; left > 0; left -= len, i++) { 866576ed913SChristoph Hellwig struct page *page = pages[i]; 8672cefe4dbSKent Overstreet 868576ed913SChristoph Hellwig len = min_t(size_t, PAGE_SIZE - offset, left); 869576ed913SChristoph Hellwig if (WARN_ON_ONCE(bio_add_page(bio, page, len, offset) != len)) 870576ed913SChristoph Hellwig return -EINVAL; 871576ed913SChristoph Hellwig offset = 0; 8722cefe4dbSKent Overstreet } 8732cefe4dbSKent Overstreet 8742cefe4dbSKent Overstreet iov_iter_advance(iter, size); 8752cefe4dbSKent Overstreet return 0; 8762cefe4dbSKent Overstreet } 87717d51b10SMartin Wilck 87817d51b10SMartin Wilck /** 87917d51b10SMartin Wilck * bio_iov_iter_get_pages - pin user or kernel pages and add them to a bio 88017d51b10SMartin Wilck * @bio: bio to add pages to 88117d51b10SMartin Wilck * @iter: iov iterator describing the region to be mapped 88217d51b10SMartin Wilck * 88317d51b10SMartin Wilck * Pins pages from *iter and appends them to @bio's bvec array. The 88417d51b10SMartin Wilck * pages will have to be released using put_page() when done. 88517d51b10SMartin Wilck * The function tries, but does not guarantee, to pin as many pages as 88617d51b10SMartin Wilck * fit into the bio, or are requested in *iter, whatever is smaller. 88717d51b10SMartin Wilck * If MM encounters an error pinning the requested pages, it stops. 88817d51b10SMartin Wilck * Error is returned only if 0 pages could be pinned. 88917d51b10SMartin Wilck */ 89017d51b10SMartin Wilck int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) 89117d51b10SMartin Wilck { 89217d51b10SMartin Wilck unsigned short orig_vcnt = bio->bi_vcnt; 89317d51b10SMartin Wilck 89417d51b10SMartin Wilck do { 89517d51b10SMartin Wilck int ret = __bio_iov_iter_get_pages(bio, iter); 89617d51b10SMartin Wilck 89717d51b10SMartin Wilck if (unlikely(ret)) 89817d51b10SMartin Wilck return bio->bi_vcnt > orig_vcnt ? 0 : ret; 89917d51b10SMartin Wilck 90017d51b10SMartin Wilck } while (iov_iter_count(iter) && !bio_full(bio)); 90117d51b10SMartin Wilck 90217d51b10SMartin Wilck return 0; 90317d51b10SMartin Wilck } 9042cefe4dbSKent Overstreet EXPORT_SYMBOL_GPL(bio_iov_iter_get_pages); 9052cefe4dbSKent Overstreet 9064246a0b6SChristoph Hellwig static void submit_bio_wait_endio(struct bio *bio) 907f9c78b2bSJens Axboe { 90865e53aabSChristoph Hellwig complete(bio->bi_private); 909f9c78b2bSJens Axboe } 910f9c78b2bSJens Axboe 911f9c78b2bSJens Axboe /** 912f9c78b2bSJens Axboe * submit_bio_wait - submit a bio, and wait until it completes 913f9c78b2bSJens Axboe * @bio: The &struct bio which describes the I/O 914f9c78b2bSJens Axboe * 915f9c78b2bSJens Axboe * Simple wrapper around submit_bio(). Returns 0 on success, or the error from 916f9c78b2bSJens Axboe * bio_endio() on failure. 9173d289d68SJan Kara * 9183d289d68SJan Kara * WARNING: Unlike to how submit_bio() is usually used, this function does not 9193d289d68SJan Kara * result in bio reference to be consumed. The caller must drop the reference 9203d289d68SJan Kara * on his own. 921f9c78b2bSJens Axboe */ 9224e49ea4aSMike Christie int submit_bio_wait(struct bio *bio) 923f9c78b2bSJens Axboe { 924e319e1fbSByungchul Park DECLARE_COMPLETION_ONSTACK_MAP(done, bio->bi_disk->lockdep_map); 925f9c78b2bSJens Axboe 92665e53aabSChristoph Hellwig bio->bi_private = &done; 927f9c78b2bSJens Axboe bio->bi_end_io = submit_bio_wait_endio; 9281eff9d32SJens Axboe bio->bi_opf |= REQ_SYNC; 9294e49ea4aSMike Christie submit_bio(bio); 93065e53aabSChristoph Hellwig wait_for_completion_io(&done); 931f9c78b2bSJens Axboe 93265e53aabSChristoph Hellwig return blk_status_to_errno(bio->bi_status); 933f9c78b2bSJens Axboe } 934f9c78b2bSJens Axboe EXPORT_SYMBOL(submit_bio_wait); 935f9c78b2bSJens Axboe 936f9c78b2bSJens Axboe /** 937f9c78b2bSJens Axboe * bio_advance - increment/complete a bio by some number of bytes 938f9c78b2bSJens Axboe * @bio: bio to advance 939f9c78b2bSJens Axboe * @bytes: number of bytes to complete 940f9c78b2bSJens Axboe * 941f9c78b2bSJens Axboe * This updates bi_sector, bi_size and bi_idx; if the number of bytes to 942f9c78b2bSJens Axboe * complete doesn't align with a bvec boundary, then bv_len and bv_offset will 943f9c78b2bSJens Axboe * be updated on the last bvec as well. 944f9c78b2bSJens Axboe * 945f9c78b2bSJens Axboe * @bio will then represent the remaining, uncompleted portion of the io. 946f9c78b2bSJens Axboe */ 947f9c78b2bSJens Axboe void bio_advance(struct bio *bio, unsigned bytes) 948f9c78b2bSJens Axboe { 949f9c78b2bSJens Axboe if (bio_integrity(bio)) 950f9c78b2bSJens Axboe bio_integrity_advance(bio, bytes); 951f9c78b2bSJens Axboe 952f9c78b2bSJens Axboe bio_advance_iter(bio, &bio->bi_iter, bytes); 953f9c78b2bSJens Axboe } 954f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_advance); 955f9c78b2bSJens Axboe 95645db54d5SKent Overstreet void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter, 95745db54d5SKent Overstreet struct bio *src, struct bvec_iter *src_iter) 958f9c78b2bSJens Axboe { 959f9c78b2bSJens Axboe struct bio_vec src_bv, dst_bv; 960f9c78b2bSJens Axboe void *src_p, *dst_p; 961f9c78b2bSJens Axboe unsigned bytes; 962f9c78b2bSJens Axboe 96345db54d5SKent Overstreet while (src_iter->bi_size && dst_iter->bi_size) { 96445db54d5SKent Overstreet src_bv = bio_iter_iovec(src, *src_iter); 96545db54d5SKent Overstreet dst_bv = bio_iter_iovec(dst, *dst_iter); 96645db54d5SKent Overstreet 96745db54d5SKent Overstreet bytes = min(src_bv.bv_len, dst_bv.bv_len); 96845db54d5SKent Overstreet 96945db54d5SKent Overstreet src_p = kmap_atomic(src_bv.bv_page); 97045db54d5SKent Overstreet dst_p = kmap_atomic(dst_bv.bv_page); 97145db54d5SKent Overstreet 97245db54d5SKent Overstreet memcpy(dst_p + dst_bv.bv_offset, 97345db54d5SKent Overstreet src_p + src_bv.bv_offset, 97445db54d5SKent Overstreet bytes); 97545db54d5SKent Overstreet 97645db54d5SKent Overstreet kunmap_atomic(dst_p); 97745db54d5SKent Overstreet kunmap_atomic(src_p); 97845db54d5SKent Overstreet 9796e6e811dSKent Overstreet flush_dcache_page(dst_bv.bv_page); 9806e6e811dSKent Overstreet 98145db54d5SKent Overstreet bio_advance_iter(src, src_iter, bytes); 98245db54d5SKent Overstreet bio_advance_iter(dst, dst_iter, bytes); 98345db54d5SKent Overstreet } 98445db54d5SKent Overstreet } 98545db54d5SKent Overstreet EXPORT_SYMBOL(bio_copy_data_iter); 98645db54d5SKent Overstreet 98745db54d5SKent Overstreet /** 98845db54d5SKent Overstreet * bio_copy_data - copy contents of data buffers from one bio to another 98945db54d5SKent Overstreet * @src: source bio 99045db54d5SKent Overstreet * @dst: destination bio 99145db54d5SKent Overstreet * 99245db54d5SKent Overstreet * Stops when it reaches the end of either @src or @dst - that is, copies 99345db54d5SKent Overstreet * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios). 99445db54d5SKent Overstreet */ 99545db54d5SKent Overstreet void bio_copy_data(struct bio *dst, struct bio *src) 99645db54d5SKent Overstreet { 99745db54d5SKent Overstreet struct bvec_iter src_iter = src->bi_iter; 99845db54d5SKent Overstreet struct bvec_iter dst_iter = dst->bi_iter; 99945db54d5SKent Overstreet 100045db54d5SKent Overstreet bio_copy_data_iter(dst, &dst_iter, src, &src_iter); 100145db54d5SKent Overstreet } 100245db54d5SKent Overstreet EXPORT_SYMBOL(bio_copy_data); 100345db54d5SKent Overstreet 100445db54d5SKent Overstreet /** 100545db54d5SKent Overstreet * bio_list_copy_data - copy contents of data buffers from one chain of bios to 100645db54d5SKent Overstreet * another 100745db54d5SKent Overstreet * @src: source bio list 100845db54d5SKent Overstreet * @dst: destination bio list 100945db54d5SKent Overstreet * 101045db54d5SKent Overstreet * Stops when it reaches the end of either the @src list or @dst list - that is, 101145db54d5SKent Overstreet * copies min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of 101245db54d5SKent Overstreet * bios). 101345db54d5SKent Overstreet */ 101445db54d5SKent Overstreet void bio_list_copy_data(struct bio *dst, struct bio *src) 101545db54d5SKent Overstreet { 101645db54d5SKent Overstreet struct bvec_iter src_iter = src->bi_iter; 101745db54d5SKent Overstreet struct bvec_iter dst_iter = dst->bi_iter; 101845db54d5SKent Overstreet 1019f9c78b2bSJens Axboe while (1) { 1020f9c78b2bSJens Axboe if (!src_iter.bi_size) { 1021f9c78b2bSJens Axboe src = src->bi_next; 1022f9c78b2bSJens Axboe if (!src) 1023f9c78b2bSJens Axboe break; 1024f9c78b2bSJens Axboe 1025f9c78b2bSJens Axboe src_iter = src->bi_iter; 1026f9c78b2bSJens Axboe } 1027f9c78b2bSJens Axboe 1028f9c78b2bSJens Axboe if (!dst_iter.bi_size) { 1029f9c78b2bSJens Axboe dst = dst->bi_next; 1030f9c78b2bSJens Axboe if (!dst) 1031f9c78b2bSJens Axboe break; 1032f9c78b2bSJens Axboe 1033f9c78b2bSJens Axboe dst_iter = dst->bi_iter; 1034f9c78b2bSJens Axboe } 1035f9c78b2bSJens Axboe 103645db54d5SKent Overstreet bio_copy_data_iter(dst, &dst_iter, src, &src_iter); 1037f9c78b2bSJens Axboe } 1038f9c78b2bSJens Axboe } 103945db54d5SKent Overstreet EXPORT_SYMBOL(bio_list_copy_data); 1040f9c78b2bSJens Axboe 1041f9c78b2bSJens Axboe struct bio_map_data { 1042f9c78b2bSJens Axboe int is_our_pages; 104326e49cfcSKent Overstreet struct iov_iter iter; 104426e49cfcSKent Overstreet struct iovec iov[]; 1045f9c78b2bSJens Axboe }; 1046f9c78b2bSJens Axboe 10470e5b935dSAl Viro static struct bio_map_data *bio_alloc_map_data(struct iov_iter *data, 1048f9c78b2bSJens Axboe gfp_t gfp_mask) 1049f9c78b2bSJens Axboe { 10500e5b935dSAl Viro struct bio_map_data *bmd; 10510e5b935dSAl Viro if (data->nr_segs > UIO_MAXIOV) 1052f9c78b2bSJens Axboe return NULL; 1053f9c78b2bSJens Axboe 10540e5b935dSAl Viro bmd = kmalloc(sizeof(struct bio_map_data) + 10550e5b935dSAl Viro sizeof(struct iovec) * data->nr_segs, gfp_mask); 10560e5b935dSAl Viro if (!bmd) 10570e5b935dSAl Viro return NULL; 10580e5b935dSAl Viro memcpy(bmd->iov, data->iov, sizeof(struct iovec) * data->nr_segs); 10590e5b935dSAl Viro bmd->iter = *data; 10600e5b935dSAl Viro bmd->iter.iov = bmd->iov; 10610e5b935dSAl Viro return bmd; 1062f9c78b2bSJens Axboe } 1063f9c78b2bSJens Axboe 10649124d3feSDongsu Park /** 10659124d3feSDongsu Park * bio_copy_from_iter - copy all pages from iov_iter to bio 10669124d3feSDongsu Park * @bio: The &struct bio which describes the I/O as destination 10679124d3feSDongsu Park * @iter: iov_iter as source 10689124d3feSDongsu Park * 10699124d3feSDongsu Park * Copy all pages from iov_iter to bio. 10709124d3feSDongsu Park * Returns 0 on success, or error on failure. 10719124d3feSDongsu Park */ 107298a09d61SAl Viro static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter) 1073f9c78b2bSJens Axboe { 10749124d3feSDongsu Park int i; 1075f9c78b2bSJens Axboe struct bio_vec *bvec; 1076f9c78b2bSJens Axboe 1077f9c78b2bSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 10789124d3feSDongsu Park ssize_t ret; 1079f9c78b2bSJens Axboe 10809124d3feSDongsu Park ret = copy_page_from_iter(bvec->bv_page, 10819124d3feSDongsu Park bvec->bv_offset, 10829124d3feSDongsu Park bvec->bv_len, 108398a09d61SAl Viro iter); 1084f9c78b2bSJens Axboe 108598a09d61SAl Viro if (!iov_iter_count(iter)) 10869124d3feSDongsu Park break; 1087f9c78b2bSJens Axboe 10889124d3feSDongsu Park if (ret < bvec->bv_len) 10899124d3feSDongsu Park return -EFAULT; 1090f9c78b2bSJens Axboe } 1091f9c78b2bSJens Axboe 10929124d3feSDongsu Park return 0; 1093f9c78b2bSJens Axboe } 1094f9c78b2bSJens Axboe 10959124d3feSDongsu Park /** 10969124d3feSDongsu Park * bio_copy_to_iter - copy all pages from bio to iov_iter 10979124d3feSDongsu Park * @bio: The &struct bio which describes the I/O as source 10989124d3feSDongsu Park * @iter: iov_iter as destination 10999124d3feSDongsu Park * 11009124d3feSDongsu Park * Copy all pages from bio to iov_iter. 11019124d3feSDongsu Park * Returns 0 on success, or error on failure. 11029124d3feSDongsu Park */ 11039124d3feSDongsu Park static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter) 11049124d3feSDongsu Park { 11059124d3feSDongsu Park int i; 11069124d3feSDongsu Park struct bio_vec *bvec; 11079124d3feSDongsu Park 11089124d3feSDongsu Park bio_for_each_segment_all(bvec, bio, i) { 11099124d3feSDongsu Park ssize_t ret; 11109124d3feSDongsu Park 11119124d3feSDongsu Park ret = copy_page_to_iter(bvec->bv_page, 11129124d3feSDongsu Park bvec->bv_offset, 11139124d3feSDongsu Park bvec->bv_len, 11149124d3feSDongsu Park &iter); 11159124d3feSDongsu Park 11169124d3feSDongsu Park if (!iov_iter_count(&iter)) 11179124d3feSDongsu Park break; 11189124d3feSDongsu Park 11199124d3feSDongsu Park if (ret < bvec->bv_len) 11209124d3feSDongsu Park return -EFAULT; 11219124d3feSDongsu Park } 11229124d3feSDongsu Park 11239124d3feSDongsu Park return 0; 1124f9c78b2bSJens Axboe } 1125f9c78b2bSJens Axboe 1126491221f8SGuoqing Jiang void bio_free_pages(struct bio *bio) 11271dfa0f68SChristoph Hellwig { 11281dfa0f68SChristoph Hellwig struct bio_vec *bvec; 11291dfa0f68SChristoph Hellwig int i; 11301dfa0f68SChristoph Hellwig 11311dfa0f68SChristoph Hellwig bio_for_each_segment_all(bvec, bio, i) 11321dfa0f68SChristoph Hellwig __free_page(bvec->bv_page); 11331dfa0f68SChristoph Hellwig } 1134491221f8SGuoqing Jiang EXPORT_SYMBOL(bio_free_pages); 11351dfa0f68SChristoph Hellwig 1136f9c78b2bSJens Axboe /** 1137f9c78b2bSJens Axboe * bio_uncopy_user - finish previously mapped bio 1138f9c78b2bSJens Axboe * @bio: bio being terminated 1139f9c78b2bSJens Axboe * 1140ddad8dd0SChristoph Hellwig * Free pages allocated from bio_copy_user_iov() and write back data 1141f9c78b2bSJens Axboe * to user space in case of a read. 1142f9c78b2bSJens Axboe */ 1143f9c78b2bSJens Axboe int bio_uncopy_user(struct bio *bio) 1144f9c78b2bSJens Axboe { 1145f9c78b2bSJens Axboe struct bio_map_data *bmd = bio->bi_private; 11461dfa0f68SChristoph Hellwig int ret = 0; 1147f9c78b2bSJens Axboe 1148f9c78b2bSJens Axboe if (!bio_flagged(bio, BIO_NULL_MAPPED)) { 1149f9c78b2bSJens Axboe /* 1150f9c78b2bSJens Axboe * if we're in a workqueue, the request is orphaned, so 11512d99b55dSHannes Reinecke * don't copy into a random user address space, just free 11522d99b55dSHannes Reinecke * and return -EINTR so user space doesn't expect any data. 1153f9c78b2bSJens Axboe */ 11542d99b55dSHannes Reinecke if (!current->mm) 11552d99b55dSHannes Reinecke ret = -EINTR; 11562d99b55dSHannes Reinecke else if (bio_data_dir(bio) == READ) 11579124d3feSDongsu Park ret = bio_copy_to_iter(bio, bmd->iter); 11581dfa0f68SChristoph Hellwig if (bmd->is_our_pages) 11591dfa0f68SChristoph Hellwig bio_free_pages(bio); 1160f9c78b2bSJens Axboe } 1161f9c78b2bSJens Axboe kfree(bmd); 1162f9c78b2bSJens Axboe bio_put(bio); 1163f9c78b2bSJens Axboe return ret; 1164f9c78b2bSJens Axboe } 1165f9c78b2bSJens Axboe 1166f9c78b2bSJens Axboe /** 1167f9c78b2bSJens Axboe * bio_copy_user_iov - copy user data to bio 1168f9c78b2bSJens Axboe * @q: destination block queue 1169f9c78b2bSJens Axboe * @map_data: pointer to the rq_map_data holding pages (if necessary) 117026e49cfcSKent Overstreet * @iter: iovec iterator 1171f9c78b2bSJens Axboe * @gfp_mask: memory allocation flags 1172f9c78b2bSJens Axboe * 1173f9c78b2bSJens Axboe * Prepares and returns a bio for indirect user io, bouncing data 1174f9c78b2bSJens Axboe * to/from kernel pages as necessary. Must be paired with 1175f9c78b2bSJens Axboe * call bio_uncopy_user() on io completion. 1176f9c78b2bSJens Axboe */ 1177f9c78b2bSJens Axboe struct bio *bio_copy_user_iov(struct request_queue *q, 1178f9c78b2bSJens Axboe struct rq_map_data *map_data, 1179e81cef5dSAl Viro struct iov_iter *iter, 118026e49cfcSKent Overstreet gfp_t gfp_mask) 1181f9c78b2bSJens Axboe { 1182f9c78b2bSJens Axboe struct bio_map_data *bmd; 1183f9c78b2bSJens Axboe struct page *page; 1184f9c78b2bSJens Axboe struct bio *bio; 1185d16d44ebSAl Viro int i = 0, ret; 1186d16d44ebSAl Viro int nr_pages; 118726e49cfcSKent Overstreet unsigned int len = iter->count; 1188bd5ceceaSGeliang Tang unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0; 1189f9c78b2bSJens Axboe 11900e5b935dSAl Viro bmd = bio_alloc_map_data(iter, gfp_mask); 1191f9c78b2bSJens Axboe if (!bmd) 1192f9c78b2bSJens Axboe return ERR_PTR(-ENOMEM); 1193f9c78b2bSJens Axboe 119426e49cfcSKent Overstreet /* 119526e49cfcSKent Overstreet * We need to do a deep copy of the iov_iter including the iovecs. 119626e49cfcSKent Overstreet * The caller provided iov might point to an on-stack or otherwise 119726e49cfcSKent Overstreet * shortlived one. 119826e49cfcSKent Overstreet */ 119926e49cfcSKent Overstreet bmd->is_our_pages = map_data ? 0 : 1; 120026e49cfcSKent Overstreet 1201d16d44ebSAl Viro nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE); 1202d16d44ebSAl Viro if (nr_pages > BIO_MAX_PAGES) 1203d16d44ebSAl Viro nr_pages = BIO_MAX_PAGES; 1204f9c78b2bSJens Axboe 1205f9c78b2bSJens Axboe ret = -ENOMEM; 1206f9c78b2bSJens Axboe bio = bio_kmalloc(gfp_mask, nr_pages); 1207f9c78b2bSJens Axboe if (!bio) 1208f9c78b2bSJens Axboe goto out_bmd; 1209f9c78b2bSJens Axboe 1210f9c78b2bSJens Axboe ret = 0; 1211f9c78b2bSJens Axboe 1212f9c78b2bSJens Axboe if (map_data) { 1213f9c78b2bSJens Axboe nr_pages = 1 << map_data->page_order; 1214f9c78b2bSJens Axboe i = map_data->offset / PAGE_SIZE; 1215f9c78b2bSJens Axboe } 1216f9c78b2bSJens Axboe while (len) { 1217f9c78b2bSJens Axboe unsigned int bytes = PAGE_SIZE; 1218f9c78b2bSJens Axboe 1219f9c78b2bSJens Axboe bytes -= offset; 1220f9c78b2bSJens Axboe 1221f9c78b2bSJens Axboe if (bytes > len) 1222f9c78b2bSJens Axboe bytes = len; 1223f9c78b2bSJens Axboe 1224f9c78b2bSJens Axboe if (map_data) { 1225f9c78b2bSJens Axboe if (i == map_data->nr_entries * nr_pages) { 1226f9c78b2bSJens Axboe ret = -ENOMEM; 1227f9c78b2bSJens Axboe break; 1228f9c78b2bSJens Axboe } 1229f9c78b2bSJens Axboe 1230f9c78b2bSJens Axboe page = map_data->pages[i / nr_pages]; 1231f9c78b2bSJens Axboe page += (i % nr_pages); 1232f9c78b2bSJens Axboe 1233f9c78b2bSJens Axboe i++; 1234f9c78b2bSJens Axboe } else { 1235f9c78b2bSJens Axboe page = alloc_page(q->bounce_gfp | gfp_mask); 1236f9c78b2bSJens Axboe if (!page) { 1237f9c78b2bSJens Axboe ret = -ENOMEM; 1238f9c78b2bSJens Axboe break; 1239f9c78b2bSJens Axboe } 1240f9c78b2bSJens Axboe } 1241f9c78b2bSJens Axboe 1242f9c78b2bSJens Axboe if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) 1243f9c78b2bSJens Axboe break; 1244f9c78b2bSJens Axboe 1245f9c78b2bSJens Axboe len -= bytes; 1246f9c78b2bSJens Axboe offset = 0; 1247f9c78b2bSJens Axboe } 1248f9c78b2bSJens Axboe 1249f9c78b2bSJens Axboe if (ret) 1250f9c78b2bSJens Axboe goto cleanup; 1251f9c78b2bSJens Axboe 12522884d0beSAl Viro if (map_data) 12532884d0beSAl Viro map_data->offset += bio->bi_iter.bi_size; 12542884d0beSAl Viro 1255f9c78b2bSJens Axboe /* 1256f9c78b2bSJens Axboe * success 1257f9c78b2bSJens Axboe */ 125800e23707SDavid Howells if ((iov_iter_rw(iter) == WRITE && (!map_data || !map_data->null_mapped)) || 1259f9c78b2bSJens Axboe (map_data && map_data->from_user)) { 126098a09d61SAl Viro ret = bio_copy_from_iter(bio, iter); 1261f9c78b2bSJens Axboe if (ret) 1262f9c78b2bSJens Axboe goto cleanup; 126398a09d61SAl Viro } else { 1264f3587d76SKeith Busch zero_fill_bio(bio); 1265e81cef5dSAl Viro iov_iter_advance(iter, bio->bi_iter.bi_size); 1266f9c78b2bSJens Axboe } 1267f9c78b2bSJens Axboe 126826e49cfcSKent Overstreet bio->bi_private = bmd; 12692884d0beSAl Viro if (map_data && map_data->null_mapped) 12702884d0beSAl Viro bio_set_flag(bio, BIO_NULL_MAPPED); 1271f9c78b2bSJens Axboe return bio; 1272f9c78b2bSJens Axboe cleanup: 1273f9c78b2bSJens Axboe if (!map_data) 12741dfa0f68SChristoph Hellwig bio_free_pages(bio); 1275f9c78b2bSJens Axboe bio_put(bio); 1276f9c78b2bSJens Axboe out_bmd: 1277f9c78b2bSJens Axboe kfree(bmd); 1278f9c78b2bSJens Axboe return ERR_PTR(ret); 1279f9c78b2bSJens Axboe } 1280f9c78b2bSJens Axboe 128137f19e57SChristoph Hellwig /** 128237f19e57SChristoph Hellwig * bio_map_user_iov - map user iovec into bio 128337f19e57SChristoph Hellwig * @q: the struct request_queue for the bio 128437f19e57SChristoph Hellwig * @iter: iovec iterator 128537f19e57SChristoph Hellwig * @gfp_mask: memory allocation flags 128637f19e57SChristoph Hellwig * 128737f19e57SChristoph Hellwig * Map the user space address into a bio suitable for io to a block 128837f19e57SChristoph Hellwig * device. Returns an error pointer in case of error. 128937f19e57SChristoph Hellwig */ 129037f19e57SChristoph Hellwig struct bio *bio_map_user_iov(struct request_queue *q, 1291e81cef5dSAl Viro struct iov_iter *iter, 129226e49cfcSKent Overstreet gfp_t gfp_mask) 1293f9c78b2bSJens Axboe { 129426e49cfcSKent Overstreet int j; 1295f9c78b2bSJens Axboe struct bio *bio; 1296076098e5SAl Viro int ret; 12972b04e8f6SAl Viro struct bio_vec *bvec; 1298f9c78b2bSJens Axboe 1299b282cc76SAl Viro if (!iov_iter_count(iter)) 1300f9c78b2bSJens Axboe return ERR_PTR(-EINVAL); 1301f9c78b2bSJens Axboe 1302b282cc76SAl Viro bio = bio_kmalloc(gfp_mask, iov_iter_npages(iter, BIO_MAX_PAGES)); 1303f9c78b2bSJens Axboe if (!bio) 1304f9c78b2bSJens Axboe return ERR_PTR(-ENOMEM); 1305f9c78b2bSJens Axboe 13060a0f1513SAl Viro while (iov_iter_count(iter)) { 1307629e42bcSAl Viro struct page **pages; 1308076098e5SAl Viro ssize_t bytes; 1309076098e5SAl Viro size_t offs, added = 0; 1310076098e5SAl Viro int npages; 1311f9c78b2bSJens Axboe 13120a0f1513SAl Viro bytes = iov_iter_get_pages_alloc(iter, &pages, LONG_MAX, &offs); 1313076098e5SAl Viro if (unlikely(bytes <= 0)) { 1314076098e5SAl Viro ret = bytes ? bytes : -EFAULT; 1315f9c78b2bSJens Axboe goto out_unmap; 1316f9c78b2bSJens Axboe } 1317f9c78b2bSJens Axboe 1318076098e5SAl Viro npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE); 1319076098e5SAl Viro 132098f0bc99SAl Viro if (unlikely(offs & queue_dma_alignment(q))) { 132198f0bc99SAl Viro ret = -EINVAL; 132298f0bc99SAl Viro j = 0; 132398f0bc99SAl Viro } else { 1324629e42bcSAl Viro for (j = 0; j < npages; j++) { 132598f0bc99SAl Viro struct page *page = pages[j]; 1326076098e5SAl Viro unsigned int n = PAGE_SIZE - offs; 132795d78c28SVitaly Mayatskikh unsigned short prev_bi_vcnt = bio->bi_vcnt; 1328f9c78b2bSJens Axboe 1329076098e5SAl Viro if (n > bytes) 1330076098e5SAl Viro n = bytes; 1331f9c78b2bSJens Axboe 133298f0bc99SAl Viro if (!bio_add_pc_page(q, bio, page, n, offs)) 1333f9c78b2bSJens Axboe break; 1334f9c78b2bSJens Axboe 133595d78c28SVitaly Mayatskikh /* 133695d78c28SVitaly Mayatskikh * check if vector was merged with previous 133795d78c28SVitaly Mayatskikh * drop page reference if needed 133895d78c28SVitaly Mayatskikh */ 133995d78c28SVitaly Mayatskikh if (bio->bi_vcnt == prev_bi_vcnt) 134098f0bc99SAl Viro put_page(page); 134195d78c28SVitaly Mayatskikh 1342076098e5SAl Viro added += n; 1343076098e5SAl Viro bytes -= n; 1344076098e5SAl Viro offs = 0; 1345f9c78b2bSJens Axboe } 13460a0f1513SAl Viro iov_iter_advance(iter, added); 134798f0bc99SAl Viro } 1348f9c78b2bSJens Axboe /* 1349f9c78b2bSJens Axboe * release the pages we didn't map into the bio, if any 1350f9c78b2bSJens Axboe */ 1351629e42bcSAl Viro while (j < npages) 135209cbfeafSKirill A. Shutemov put_page(pages[j++]); 1353629e42bcSAl Viro kvfree(pages); 1354e2e115d1SAl Viro /* couldn't stuff something into bio? */ 1355e2e115d1SAl Viro if (bytes) 1356e2e115d1SAl Viro break; 1357f9c78b2bSJens Axboe } 1358f9c78b2bSJens Axboe 1359b7c44ed9SJens Axboe bio_set_flag(bio, BIO_USER_MAPPED); 136037f19e57SChristoph Hellwig 136137f19e57SChristoph Hellwig /* 13625fad1b64SBart Van Assche * subtle -- if bio_map_user_iov() ended up bouncing a bio, 136337f19e57SChristoph Hellwig * it would normally disappear when its bi_end_io is run. 136437f19e57SChristoph Hellwig * however, we need it for the unmap, so grab an extra 136537f19e57SChristoph Hellwig * reference to it 136637f19e57SChristoph Hellwig */ 136737f19e57SChristoph Hellwig bio_get(bio); 1368f9c78b2bSJens Axboe return bio; 1369f9c78b2bSJens Axboe 1370f9c78b2bSJens Axboe out_unmap: 13712b04e8f6SAl Viro bio_for_each_segment_all(bvec, bio, j) { 13722b04e8f6SAl Viro put_page(bvec->bv_page); 1373f9c78b2bSJens Axboe } 1374f9c78b2bSJens Axboe bio_put(bio); 1375f9c78b2bSJens Axboe return ERR_PTR(ret); 1376f9c78b2bSJens Axboe } 1377f9c78b2bSJens Axboe 1378f9c78b2bSJens Axboe static void __bio_unmap_user(struct bio *bio) 1379f9c78b2bSJens Axboe { 1380f9c78b2bSJens Axboe struct bio_vec *bvec; 1381f9c78b2bSJens Axboe int i; 1382f9c78b2bSJens Axboe 1383f9c78b2bSJens Axboe /* 1384f9c78b2bSJens Axboe * make sure we dirty pages we wrote to 1385f9c78b2bSJens Axboe */ 1386f9c78b2bSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 1387f9c78b2bSJens Axboe if (bio_data_dir(bio) == READ) 1388f9c78b2bSJens Axboe set_page_dirty_lock(bvec->bv_page); 1389f9c78b2bSJens Axboe 139009cbfeafSKirill A. Shutemov put_page(bvec->bv_page); 1391f9c78b2bSJens Axboe } 1392f9c78b2bSJens Axboe 1393f9c78b2bSJens Axboe bio_put(bio); 1394f9c78b2bSJens Axboe } 1395f9c78b2bSJens Axboe 1396f9c78b2bSJens Axboe /** 1397f9c78b2bSJens Axboe * bio_unmap_user - unmap a bio 1398f9c78b2bSJens Axboe * @bio: the bio being unmapped 1399f9c78b2bSJens Axboe * 14005fad1b64SBart Van Assche * Unmap a bio previously mapped by bio_map_user_iov(). Must be called from 14015fad1b64SBart Van Assche * process context. 1402f9c78b2bSJens Axboe * 1403f9c78b2bSJens Axboe * bio_unmap_user() may sleep. 1404f9c78b2bSJens Axboe */ 1405f9c78b2bSJens Axboe void bio_unmap_user(struct bio *bio) 1406f9c78b2bSJens Axboe { 1407f9c78b2bSJens Axboe __bio_unmap_user(bio); 1408f9c78b2bSJens Axboe bio_put(bio); 1409f9c78b2bSJens Axboe } 1410f9c78b2bSJens Axboe 14114246a0b6SChristoph Hellwig static void bio_map_kern_endio(struct bio *bio) 1412f9c78b2bSJens Axboe { 1413f9c78b2bSJens Axboe bio_put(bio); 1414f9c78b2bSJens Axboe } 1415f9c78b2bSJens Axboe 141675c72b83SChristoph Hellwig /** 141775c72b83SChristoph Hellwig * bio_map_kern - map kernel address into bio 141875c72b83SChristoph Hellwig * @q: the struct request_queue for the bio 141975c72b83SChristoph Hellwig * @data: pointer to buffer to map 142075c72b83SChristoph Hellwig * @len: length in bytes 142175c72b83SChristoph Hellwig * @gfp_mask: allocation flags for bio allocation 142275c72b83SChristoph Hellwig * 142375c72b83SChristoph Hellwig * Map the kernel address into a bio suitable for io to a block 142475c72b83SChristoph Hellwig * device. Returns an error pointer in case of error. 142575c72b83SChristoph Hellwig */ 142675c72b83SChristoph Hellwig struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len, 142775c72b83SChristoph Hellwig gfp_t gfp_mask) 1428f9c78b2bSJens Axboe { 1429f9c78b2bSJens Axboe unsigned long kaddr = (unsigned long)data; 1430f9c78b2bSJens Axboe unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; 1431f9c78b2bSJens Axboe unsigned long start = kaddr >> PAGE_SHIFT; 1432f9c78b2bSJens Axboe const int nr_pages = end - start; 1433f9c78b2bSJens Axboe int offset, i; 1434f9c78b2bSJens Axboe struct bio *bio; 1435f9c78b2bSJens Axboe 1436f9c78b2bSJens Axboe bio = bio_kmalloc(gfp_mask, nr_pages); 1437f9c78b2bSJens Axboe if (!bio) 1438f9c78b2bSJens Axboe return ERR_PTR(-ENOMEM); 1439f9c78b2bSJens Axboe 1440f9c78b2bSJens Axboe offset = offset_in_page(kaddr); 1441f9c78b2bSJens Axboe for (i = 0; i < nr_pages; i++) { 1442f9c78b2bSJens Axboe unsigned int bytes = PAGE_SIZE - offset; 1443f9c78b2bSJens Axboe 1444f9c78b2bSJens Axboe if (len <= 0) 1445f9c78b2bSJens Axboe break; 1446f9c78b2bSJens Axboe 1447f9c78b2bSJens Axboe if (bytes > len) 1448f9c78b2bSJens Axboe bytes = len; 1449f9c78b2bSJens Axboe 1450f9c78b2bSJens Axboe if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, 145175c72b83SChristoph Hellwig offset) < bytes) { 145275c72b83SChristoph Hellwig /* we don't support partial mappings */ 145375c72b83SChristoph Hellwig bio_put(bio); 145475c72b83SChristoph Hellwig return ERR_PTR(-EINVAL); 145575c72b83SChristoph Hellwig } 1456f9c78b2bSJens Axboe 1457f9c78b2bSJens Axboe data += bytes; 1458f9c78b2bSJens Axboe len -= bytes; 1459f9c78b2bSJens Axboe offset = 0; 1460f9c78b2bSJens Axboe } 1461f9c78b2bSJens Axboe 1462f9c78b2bSJens Axboe bio->bi_end_io = bio_map_kern_endio; 1463f9c78b2bSJens Axboe return bio; 1464f9c78b2bSJens Axboe } 1465f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_map_kern); 1466f9c78b2bSJens Axboe 14674246a0b6SChristoph Hellwig static void bio_copy_kern_endio(struct bio *bio) 1468f9c78b2bSJens Axboe { 14691dfa0f68SChristoph Hellwig bio_free_pages(bio); 14701dfa0f68SChristoph Hellwig bio_put(bio); 14711dfa0f68SChristoph Hellwig } 14721dfa0f68SChristoph Hellwig 14734246a0b6SChristoph Hellwig static void bio_copy_kern_endio_read(struct bio *bio) 14741dfa0f68SChristoph Hellwig { 147542d2683aSChristoph Hellwig char *p = bio->bi_private; 14761dfa0f68SChristoph Hellwig struct bio_vec *bvec; 1477f9c78b2bSJens Axboe int i; 1478f9c78b2bSJens Axboe 1479f9c78b2bSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 14801dfa0f68SChristoph Hellwig memcpy(p, page_address(bvec->bv_page), bvec->bv_len); 1481f9c78b2bSJens Axboe p += bvec->bv_len; 1482f9c78b2bSJens Axboe } 1483f9c78b2bSJens Axboe 14844246a0b6SChristoph Hellwig bio_copy_kern_endio(bio); 1485f9c78b2bSJens Axboe } 1486f9c78b2bSJens Axboe 1487f9c78b2bSJens Axboe /** 1488f9c78b2bSJens Axboe * bio_copy_kern - copy kernel address into bio 1489f9c78b2bSJens Axboe * @q: the struct request_queue for the bio 1490f9c78b2bSJens Axboe * @data: pointer to buffer to copy 1491f9c78b2bSJens Axboe * @len: length in bytes 1492f9c78b2bSJens Axboe * @gfp_mask: allocation flags for bio and page allocation 1493f9c78b2bSJens Axboe * @reading: data direction is READ 1494f9c78b2bSJens Axboe * 1495f9c78b2bSJens Axboe * copy the kernel address into a bio suitable for io to a block 1496f9c78b2bSJens Axboe * device. Returns an error pointer in case of error. 1497f9c78b2bSJens Axboe */ 1498f9c78b2bSJens Axboe struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, 1499f9c78b2bSJens Axboe gfp_t gfp_mask, int reading) 1500f9c78b2bSJens Axboe { 150142d2683aSChristoph Hellwig unsigned long kaddr = (unsigned long)data; 150242d2683aSChristoph Hellwig unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; 150342d2683aSChristoph Hellwig unsigned long start = kaddr >> PAGE_SHIFT; 150442d2683aSChristoph Hellwig struct bio *bio; 1505f9c78b2bSJens Axboe void *p = data; 15061dfa0f68SChristoph Hellwig int nr_pages = 0; 1507f9c78b2bSJens Axboe 150842d2683aSChristoph Hellwig /* 150942d2683aSChristoph Hellwig * Overflow, abort 151042d2683aSChristoph Hellwig */ 151142d2683aSChristoph Hellwig if (end < start) 151242d2683aSChristoph Hellwig return ERR_PTR(-EINVAL); 1513f9c78b2bSJens Axboe 151442d2683aSChristoph Hellwig nr_pages = end - start; 151542d2683aSChristoph Hellwig bio = bio_kmalloc(gfp_mask, nr_pages); 151642d2683aSChristoph Hellwig if (!bio) 151742d2683aSChristoph Hellwig return ERR_PTR(-ENOMEM); 151842d2683aSChristoph Hellwig 151942d2683aSChristoph Hellwig while (len) { 152042d2683aSChristoph Hellwig struct page *page; 152142d2683aSChristoph Hellwig unsigned int bytes = PAGE_SIZE; 152242d2683aSChristoph Hellwig 152342d2683aSChristoph Hellwig if (bytes > len) 152442d2683aSChristoph Hellwig bytes = len; 152542d2683aSChristoph Hellwig 152642d2683aSChristoph Hellwig page = alloc_page(q->bounce_gfp | gfp_mask); 152742d2683aSChristoph Hellwig if (!page) 152842d2683aSChristoph Hellwig goto cleanup; 152942d2683aSChristoph Hellwig 153042d2683aSChristoph Hellwig if (!reading) 153142d2683aSChristoph Hellwig memcpy(page_address(page), p, bytes); 153242d2683aSChristoph Hellwig 153342d2683aSChristoph Hellwig if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) 153442d2683aSChristoph Hellwig break; 153542d2683aSChristoph Hellwig 153642d2683aSChristoph Hellwig len -= bytes; 153742d2683aSChristoph Hellwig p += bytes; 1538f9c78b2bSJens Axboe } 1539f9c78b2bSJens Axboe 15401dfa0f68SChristoph Hellwig if (reading) { 15411dfa0f68SChristoph Hellwig bio->bi_end_io = bio_copy_kern_endio_read; 154242d2683aSChristoph Hellwig bio->bi_private = data; 15431dfa0f68SChristoph Hellwig } else { 1544f9c78b2bSJens Axboe bio->bi_end_io = bio_copy_kern_endio; 15451dfa0f68SChristoph Hellwig } 15461dfa0f68SChristoph Hellwig 1547f9c78b2bSJens Axboe return bio; 154842d2683aSChristoph Hellwig 154942d2683aSChristoph Hellwig cleanup: 15501dfa0f68SChristoph Hellwig bio_free_pages(bio); 155142d2683aSChristoph Hellwig bio_put(bio); 155242d2683aSChristoph Hellwig return ERR_PTR(-ENOMEM); 1553f9c78b2bSJens Axboe } 1554f9c78b2bSJens Axboe 1555f9c78b2bSJens Axboe /* 1556f9c78b2bSJens Axboe * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions 1557f9c78b2bSJens Axboe * for performing direct-IO in BIOs. 1558f9c78b2bSJens Axboe * 1559f9c78b2bSJens Axboe * The problem is that we cannot run set_page_dirty() from interrupt context 1560f9c78b2bSJens Axboe * because the required locks are not interrupt-safe. So what we can do is to 1561f9c78b2bSJens Axboe * mark the pages dirty _before_ performing IO. And in interrupt context, 1562f9c78b2bSJens Axboe * check that the pages are still dirty. If so, fine. If not, redirty them 1563f9c78b2bSJens Axboe * in process context. 1564f9c78b2bSJens Axboe * 1565f9c78b2bSJens Axboe * We special-case compound pages here: normally this means reads into hugetlb 1566f9c78b2bSJens Axboe * pages. The logic in here doesn't really work right for compound pages 1567f9c78b2bSJens Axboe * because the VM does not uniformly chase down the head page in all cases. 1568f9c78b2bSJens Axboe * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't 1569f9c78b2bSJens Axboe * handle them at all. So we skip compound pages here at an early stage. 1570f9c78b2bSJens Axboe * 1571f9c78b2bSJens Axboe * Note that this code is very hard to test under normal circumstances because 1572f9c78b2bSJens Axboe * direct-io pins the pages with get_user_pages(). This makes 1573f9c78b2bSJens Axboe * is_page_cache_freeable return false, and the VM will not clean the pages. 1574f9c78b2bSJens Axboe * But other code (eg, flusher threads) could clean the pages if they are mapped 1575f9c78b2bSJens Axboe * pagecache. 1576f9c78b2bSJens Axboe * 1577f9c78b2bSJens Axboe * Simply disabling the call to bio_set_pages_dirty() is a good way to test the 1578f9c78b2bSJens Axboe * deferred bio dirtying paths. 1579f9c78b2bSJens Axboe */ 1580f9c78b2bSJens Axboe 1581f9c78b2bSJens Axboe /* 1582f9c78b2bSJens Axboe * bio_set_pages_dirty() will mark all the bio's pages as dirty. 1583f9c78b2bSJens Axboe */ 1584f9c78b2bSJens Axboe void bio_set_pages_dirty(struct bio *bio) 1585f9c78b2bSJens Axboe { 1586f9c78b2bSJens Axboe struct bio_vec *bvec; 1587f9c78b2bSJens Axboe int i; 1588f9c78b2bSJens Axboe 1589f9c78b2bSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 15903bb50983SChristoph Hellwig if (!PageCompound(bvec->bv_page)) 15913bb50983SChristoph Hellwig set_page_dirty_lock(bvec->bv_page); 1592f9c78b2bSJens Axboe } 1593f9c78b2bSJens Axboe } 15941900fcc4SKent Overstreet EXPORT_SYMBOL_GPL(bio_set_pages_dirty); 1595f9c78b2bSJens Axboe 1596f9c78b2bSJens Axboe static void bio_release_pages(struct bio *bio) 1597f9c78b2bSJens Axboe { 1598f9c78b2bSJens Axboe struct bio_vec *bvec; 1599f9c78b2bSJens Axboe int i; 1600f9c78b2bSJens Axboe 160124d5493fSChristoph Hellwig bio_for_each_segment_all(bvec, bio, i) 160224d5493fSChristoph Hellwig put_page(bvec->bv_page); 1603f9c78b2bSJens Axboe } 1604f9c78b2bSJens Axboe 1605f9c78b2bSJens Axboe /* 1606f9c78b2bSJens Axboe * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. 1607f9c78b2bSJens Axboe * If they are, then fine. If, however, some pages are clean then they must 1608f9c78b2bSJens Axboe * have been written out during the direct-IO read. So we take another ref on 160924d5493fSChristoph Hellwig * the BIO and re-dirty the pages in process context. 1610f9c78b2bSJens Axboe * 1611f9c78b2bSJens Axboe * It is expected that bio_check_pages_dirty() will wholly own the BIO from 1612ea1754a0SKirill A. Shutemov * here on. It will run one put_page() against each page and will run one 1613ea1754a0SKirill A. Shutemov * bio_put() against the BIO. 1614f9c78b2bSJens Axboe */ 1615f9c78b2bSJens Axboe 1616f9c78b2bSJens Axboe static void bio_dirty_fn(struct work_struct *work); 1617f9c78b2bSJens Axboe 1618f9c78b2bSJens Axboe static DECLARE_WORK(bio_dirty_work, bio_dirty_fn); 1619f9c78b2bSJens Axboe static DEFINE_SPINLOCK(bio_dirty_lock); 1620f9c78b2bSJens Axboe static struct bio *bio_dirty_list; 1621f9c78b2bSJens Axboe 1622f9c78b2bSJens Axboe /* 1623f9c78b2bSJens Axboe * This runs in process context 1624f9c78b2bSJens Axboe */ 1625f9c78b2bSJens Axboe static void bio_dirty_fn(struct work_struct *work) 1626f9c78b2bSJens Axboe { 162724d5493fSChristoph Hellwig struct bio *bio, *next; 1628f9c78b2bSJens Axboe 162924d5493fSChristoph Hellwig spin_lock_irq(&bio_dirty_lock); 163024d5493fSChristoph Hellwig next = bio_dirty_list; 1631f9c78b2bSJens Axboe bio_dirty_list = NULL; 163224d5493fSChristoph Hellwig spin_unlock_irq(&bio_dirty_lock); 1633f9c78b2bSJens Axboe 163424d5493fSChristoph Hellwig while ((bio = next) != NULL) { 163524d5493fSChristoph Hellwig next = bio->bi_private; 1636f9c78b2bSJens Axboe 1637f9c78b2bSJens Axboe bio_set_pages_dirty(bio); 1638f9c78b2bSJens Axboe bio_release_pages(bio); 1639f9c78b2bSJens Axboe bio_put(bio); 1640f9c78b2bSJens Axboe } 1641f9c78b2bSJens Axboe } 1642f9c78b2bSJens Axboe 1643f9c78b2bSJens Axboe void bio_check_pages_dirty(struct bio *bio) 1644f9c78b2bSJens Axboe { 1645f9c78b2bSJens Axboe struct bio_vec *bvec; 164624d5493fSChristoph Hellwig unsigned long flags; 1647f9c78b2bSJens Axboe int i; 1648f9c78b2bSJens Axboe 1649f9c78b2bSJens Axboe bio_for_each_segment_all(bvec, bio, i) { 165024d5493fSChristoph Hellwig if (!PageDirty(bvec->bv_page) && !PageCompound(bvec->bv_page)) 165124d5493fSChristoph Hellwig goto defer; 1652f9c78b2bSJens Axboe } 1653f9c78b2bSJens Axboe 165424d5493fSChristoph Hellwig bio_release_pages(bio); 165524d5493fSChristoph Hellwig bio_put(bio); 165624d5493fSChristoph Hellwig return; 165724d5493fSChristoph Hellwig defer: 1658f9c78b2bSJens Axboe spin_lock_irqsave(&bio_dirty_lock, flags); 1659f9c78b2bSJens Axboe bio->bi_private = bio_dirty_list; 1660f9c78b2bSJens Axboe bio_dirty_list = bio; 1661f9c78b2bSJens Axboe spin_unlock_irqrestore(&bio_dirty_lock, flags); 1662f9c78b2bSJens Axboe schedule_work(&bio_dirty_work); 1663f9c78b2bSJens Axboe } 16641900fcc4SKent Overstreet EXPORT_SYMBOL_GPL(bio_check_pages_dirty); 1665f9c78b2bSJens Axboe 1666ddcf35d3SMichael Callahan void generic_start_io_acct(struct request_queue *q, int op, 1667d62e26b3SJens Axboe unsigned long sectors, struct hd_struct *part) 1668394ffa50SGu Zheng { 1669ddcf35d3SMichael Callahan const int sgrp = op_stat_group(op); 1670394ffa50SGu Zheng int cpu = part_stat_lock(); 1671394ffa50SGu Zheng 1672d62e26b3SJens Axboe part_round_stats(q, cpu, part); 1673ddcf35d3SMichael Callahan part_stat_inc(cpu, part, ios[sgrp]); 1674ddcf35d3SMichael Callahan part_stat_add(cpu, part, sectors[sgrp], sectors); 1675ddcf35d3SMichael Callahan part_inc_in_flight(q, part, op_is_write(op)); 1676394ffa50SGu Zheng 1677394ffa50SGu Zheng part_stat_unlock(); 1678394ffa50SGu Zheng } 1679394ffa50SGu Zheng EXPORT_SYMBOL(generic_start_io_acct); 1680394ffa50SGu Zheng 1681ddcf35d3SMichael Callahan void generic_end_io_acct(struct request_queue *q, int req_op, 1682d62e26b3SJens Axboe struct hd_struct *part, unsigned long start_time) 1683394ffa50SGu Zheng { 1684394ffa50SGu Zheng unsigned long duration = jiffies - start_time; 1685ddcf35d3SMichael Callahan const int sgrp = op_stat_group(req_op); 1686394ffa50SGu Zheng int cpu = part_stat_lock(); 1687394ffa50SGu Zheng 1688b57e99b4SOmar Sandoval part_stat_add(cpu, part, nsecs[sgrp], jiffies_to_nsecs(duration)); 1689d62e26b3SJens Axboe part_round_stats(q, cpu, part); 1690ddcf35d3SMichael Callahan part_dec_in_flight(q, part, op_is_write(req_op)); 1691394ffa50SGu Zheng 1692394ffa50SGu Zheng part_stat_unlock(); 1693394ffa50SGu Zheng } 1694394ffa50SGu Zheng EXPORT_SYMBOL(generic_end_io_acct); 1695394ffa50SGu Zheng 1696f9c78b2bSJens Axboe #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1697f9c78b2bSJens Axboe void bio_flush_dcache_pages(struct bio *bi) 1698f9c78b2bSJens Axboe { 1699f9c78b2bSJens Axboe struct bio_vec bvec; 1700f9c78b2bSJens Axboe struct bvec_iter iter; 1701f9c78b2bSJens Axboe 1702f9c78b2bSJens Axboe bio_for_each_segment(bvec, bi, iter) 1703f9c78b2bSJens Axboe flush_dcache_page(bvec.bv_page); 1704f9c78b2bSJens Axboe } 1705f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_flush_dcache_pages); 1706f9c78b2bSJens Axboe #endif 1707f9c78b2bSJens Axboe 1708c4cf5261SJens Axboe static inline bool bio_remaining_done(struct bio *bio) 1709c4cf5261SJens Axboe { 1710c4cf5261SJens Axboe /* 1711c4cf5261SJens Axboe * If we're not chaining, then ->__bi_remaining is always 1 and 1712c4cf5261SJens Axboe * we always end io on the first invocation. 1713c4cf5261SJens Axboe */ 1714c4cf5261SJens Axboe if (!bio_flagged(bio, BIO_CHAIN)) 1715c4cf5261SJens Axboe return true; 1716c4cf5261SJens Axboe 1717c4cf5261SJens Axboe BUG_ON(atomic_read(&bio->__bi_remaining) <= 0); 1718c4cf5261SJens Axboe 1719326e1dbbSMike Snitzer if (atomic_dec_and_test(&bio->__bi_remaining)) { 1720b7c44ed9SJens Axboe bio_clear_flag(bio, BIO_CHAIN); 1721c4cf5261SJens Axboe return true; 1722326e1dbbSMike Snitzer } 1723c4cf5261SJens Axboe 1724c4cf5261SJens Axboe return false; 1725c4cf5261SJens Axboe } 1726c4cf5261SJens Axboe 1727f9c78b2bSJens Axboe /** 1728f9c78b2bSJens Axboe * bio_endio - end I/O on a bio 1729f9c78b2bSJens Axboe * @bio: bio 1730f9c78b2bSJens Axboe * 1731f9c78b2bSJens Axboe * Description: 17324246a0b6SChristoph Hellwig * bio_endio() will end I/O on the whole bio. bio_endio() is the preferred 17334246a0b6SChristoph Hellwig * way to end I/O on a bio. No one should call bi_end_io() directly on a 17344246a0b6SChristoph Hellwig * bio unless they own it and thus know that it has an end_io function. 1735fbbaf700SNeilBrown * 1736fbbaf700SNeilBrown * bio_endio() can be called several times on a bio that has been chained 1737fbbaf700SNeilBrown * using bio_chain(). The ->bi_end_io() function will only be called the 1738fbbaf700SNeilBrown * last time. At this point the BLK_TA_COMPLETE tracing event will be 1739fbbaf700SNeilBrown * generated if BIO_TRACE_COMPLETION is set. 1740f9c78b2bSJens Axboe **/ 17414246a0b6SChristoph Hellwig void bio_endio(struct bio *bio) 1742f9c78b2bSJens Axboe { 1743ba8c6967SChristoph Hellwig again: 17442b885517SChristoph Hellwig if (!bio_remaining_done(bio)) 1745ba8c6967SChristoph Hellwig return; 17467c20f116SChristoph Hellwig if (!bio_integrity_endio(bio)) 17477c20f116SChristoph Hellwig return; 1748f9c78b2bSJens Axboe 174967b42d0bSJosef Bacik if (bio->bi_disk) 175067b42d0bSJosef Bacik rq_qos_done_bio(bio->bi_disk->queue, bio); 175167b42d0bSJosef Bacik 1752f9c78b2bSJens Axboe /* 1753ba8c6967SChristoph Hellwig * Need to have a real endio function for chained bios, otherwise 1754ba8c6967SChristoph Hellwig * various corner cases will break (like stacking block devices that 1755ba8c6967SChristoph Hellwig * save/restore bi_end_io) - however, we want to avoid unbounded 1756ba8c6967SChristoph Hellwig * recursion and blowing the stack. Tail call optimization would 1757ba8c6967SChristoph Hellwig * handle this, but compiling with frame pointers also disables 1758ba8c6967SChristoph Hellwig * gcc's sibling call optimization. 1759f9c78b2bSJens Axboe */ 1760f9c78b2bSJens Axboe if (bio->bi_end_io == bio_chain_endio) { 176138f8baaeSChristoph Hellwig bio = __bio_chain_endio(bio); 1762ba8c6967SChristoph Hellwig goto again; 1763ba8c6967SChristoph Hellwig } 1764ba8c6967SChristoph Hellwig 176574d46992SChristoph Hellwig if (bio->bi_disk && bio_flagged(bio, BIO_TRACE_COMPLETION)) { 176674d46992SChristoph Hellwig trace_block_bio_complete(bio->bi_disk->queue, bio, 1767a462b950SBart Van Assche blk_status_to_errno(bio->bi_status)); 1768fbbaf700SNeilBrown bio_clear_flag(bio, BIO_TRACE_COMPLETION); 1769fbbaf700SNeilBrown } 1770fbbaf700SNeilBrown 17719e234eeaSShaohua Li blk_throtl_bio_endio(bio); 1772b222dd2fSShaohua Li /* release cgroup info */ 1773b222dd2fSShaohua Li bio_uninit(bio); 1774f9c78b2bSJens Axboe if (bio->bi_end_io) 17754246a0b6SChristoph Hellwig bio->bi_end_io(bio); 1776f9c78b2bSJens Axboe } 1777f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_endio); 1778f9c78b2bSJens Axboe 1779f9c78b2bSJens Axboe /** 1780f9c78b2bSJens Axboe * bio_split - split a bio 1781f9c78b2bSJens Axboe * @bio: bio to split 1782f9c78b2bSJens Axboe * @sectors: number of sectors to split from the front of @bio 1783f9c78b2bSJens Axboe * @gfp: gfp mask 1784f9c78b2bSJens Axboe * @bs: bio set to allocate from 1785f9c78b2bSJens Axboe * 1786f9c78b2bSJens Axboe * Allocates and returns a new bio which represents @sectors from the start of 1787f9c78b2bSJens Axboe * @bio, and updates @bio to represent the remaining sectors. 1788f9c78b2bSJens Axboe * 1789f3f5da62SMartin K. Petersen * Unless this is a discard request the newly allocated bio will point 1790f3f5da62SMartin K. Petersen * to @bio's bi_io_vec; it is the caller's responsibility to ensure that 1791f3f5da62SMartin K. Petersen * @bio is not freed before the split. 1792f9c78b2bSJens Axboe */ 1793f9c78b2bSJens Axboe struct bio *bio_split(struct bio *bio, int sectors, 1794f9c78b2bSJens Axboe gfp_t gfp, struct bio_set *bs) 1795f9c78b2bSJens Axboe { 1796f341a4d3SMikulas Patocka struct bio *split; 1797f9c78b2bSJens Axboe 1798f9c78b2bSJens Axboe BUG_ON(sectors <= 0); 1799f9c78b2bSJens Axboe BUG_ON(sectors >= bio_sectors(bio)); 1800f9c78b2bSJens Axboe 1801f9c78b2bSJens Axboe split = bio_clone_fast(bio, gfp, bs); 1802f9c78b2bSJens Axboe if (!split) 1803f9c78b2bSJens Axboe return NULL; 1804f9c78b2bSJens Axboe 1805f9c78b2bSJens Axboe split->bi_iter.bi_size = sectors << 9; 1806f9c78b2bSJens Axboe 1807f9c78b2bSJens Axboe if (bio_integrity(split)) 1808fbd08e76SDmitry Monakhov bio_integrity_trim(split); 1809f9c78b2bSJens Axboe 1810f9c78b2bSJens Axboe bio_advance(bio, split->bi_iter.bi_size); 1811f9c78b2bSJens Axboe 1812fbbaf700SNeilBrown if (bio_flagged(bio, BIO_TRACE_COMPLETION)) 181320d59023SGoldwyn Rodrigues bio_set_flag(split, BIO_TRACE_COMPLETION); 1814fbbaf700SNeilBrown 1815f9c78b2bSJens Axboe return split; 1816f9c78b2bSJens Axboe } 1817f9c78b2bSJens Axboe EXPORT_SYMBOL(bio_split); 1818f9c78b2bSJens Axboe 1819f9c78b2bSJens Axboe /** 1820f9c78b2bSJens Axboe * bio_trim - trim a bio 1821f9c78b2bSJens Axboe * @bio: bio to trim 1822f9c78b2bSJens Axboe * @offset: number of sectors to trim from the front of @bio 1823f9c78b2bSJens Axboe * @size: size we want to trim @bio to, in sectors 1824f9c78b2bSJens Axboe */ 1825f9c78b2bSJens Axboe void bio_trim(struct bio *bio, int offset, int size) 1826f9c78b2bSJens Axboe { 1827f9c78b2bSJens Axboe /* 'bio' is a cloned bio which we need to trim to match 1828f9c78b2bSJens Axboe * the given offset and size. 1829f9c78b2bSJens Axboe */ 1830f9c78b2bSJens Axboe 1831f9c78b2bSJens Axboe size <<= 9; 1832f9c78b2bSJens Axboe if (offset == 0 && size == bio->bi_iter.bi_size) 1833f9c78b2bSJens Axboe return; 1834f9c78b2bSJens Axboe 1835b7c44ed9SJens Axboe bio_clear_flag(bio, BIO_SEG_VALID); 1836f9c78b2bSJens Axboe 1837f9c78b2bSJens Axboe bio_advance(bio, offset << 9); 1838f9c78b2bSJens Axboe 1839f9c78b2bSJens Axboe bio->bi_iter.bi_size = size; 1840376a78abSDmitry Monakhov 1841376a78abSDmitry Monakhov if (bio_integrity(bio)) 1842fbd08e76SDmitry Monakhov bio_integrity_trim(bio); 1843376a78abSDmitry Monakhov 1844f9c78b2bSJens Axboe } 1845f9c78b2bSJens Axboe EXPORT_SYMBOL_GPL(bio_trim); 1846f9c78b2bSJens Axboe 1847f9c78b2bSJens Axboe /* 1848f9c78b2bSJens Axboe * create memory pools for biovec's in a bio_set. 1849f9c78b2bSJens Axboe * use the global biovec slabs created for general use. 1850f9c78b2bSJens Axboe */ 18518aa6ba2fSKent Overstreet int biovec_init_pool(mempool_t *pool, int pool_entries) 1852f9c78b2bSJens Axboe { 1853ed996a52SChristoph Hellwig struct biovec_slab *bp = bvec_slabs + BVEC_POOL_MAX; 1854f9c78b2bSJens Axboe 18558aa6ba2fSKent Overstreet return mempool_init_slab_pool(pool, pool_entries, bp->slab); 1856f9c78b2bSJens Axboe } 1857f9c78b2bSJens Axboe 1858917a38c7SKent Overstreet /* 1859917a38c7SKent Overstreet * bioset_exit - exit a bioset initialized with bioset_init() 1860917a38c7SKent Overstreet * 1861917a38c7SKent Overstreet * May be called on a zeroed but uninitialized bioset (i.e. allocated with 1862917a38c7SKent Overstreet * kzalloc()). 1863917a38c7SKent Overstreet */ 1864917a38c7SKent Overstreet void bioset_exit(struct bio_set *bs) 1865f9c78b2bSJens Axboe { 1866f9c78b2bSJens Axboe if (bs->rescue_workqueue) 1867f9c78b2bSJens Axboe destroy_workqueue(bs->rescue_workqueue); 1868917a38c7SKent Overstreet bs->rescue_workqueue = NULL; 1869f9c78b2bSJens Axboe 18708aa6ba2fSKent Overstreet mempool_exit(&bs->bio_pool); 18718aa6ba2fSKent Overstreet mempool_exit(&bs->bvec_pool); 1872f9c78b2bSJens Axboe 1873f9c78b2bSJens Axboe bioset_integrity_free(bs); 1874917a38c7SKent Overstreet if (bs->bio_slab) 1875f9c78b2bSJens Axboe bio_put_slab(bs); 1876917a38c7SKent Overstreet bs->bio_slab = NULL; 1877917a38c7SKent Overstreet } 1878917a38c7SKent Overstreet EXPORT_SYMBOL(bioset_exit); 1879f9c78b2bSJens Axboe 1880011067b0SNeilBrown /** 1881917a38c7SKent Overstreet * bioset_init - Initialize a bio_set 1882dad08527SKent Overstreet * @bs: pool to initialize 1883917a38c7SKent Overstreet * @pool_size: Number of bio and bio_vecs to cache in the mempool 1884917a38c7SKent Overstreet * @front_pad: Number of bytes to allocate in front of the returned bio 1885917a38c7SKent Overstreet * @flags: Flags to modify behavior, currently %BIOSET_NEED_BVECS 1886917a38c7SKent Overstreet * and %BIOSET_NEED_RESCUER 1887917a38c7SKent Overstreet * 1888dad08527SKent Overstreet * Description: 1889dad08527SKent Overstreet * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller 1890dad08527SKent Overstreet * to ask for a number of bytes to be allocated in front of the bio. 1891dad08527SKent Overstreet * Front pad allocation is useful for embedding the bio inside 1892dad08527SKent Overstreet * another structure, to avoid allocating extra data to go with the bio. 1893dad08527SKent Overstreet * Note that the bio must be embedded at the END of that structure always, 1894dad08527SKent Overstreet * or things will break badly. 1895dad08527SKent Overstreet * If %BIOSET_NEED_BVECS is set in @flags, a separate pool will be allocated 1896dad08527SKent Overstreet * for allocating iovecs. This pool is not needed e.g. for bio_clone_fast(). 1897dad08527SKent Overstreet * If %BIOSET_NEED_RESCUER is set, a workqueue is created which can be used to 1898dad08527SKent Overstreet * dispatch queued requests when the mempool runs out of space. 1899dad08527SKent Overstreet * 1900917a38c7SKent Overstreet */ 1901917a38c7SKent Overstreet int bioset_init(struct bio_set *bs, 1902917a38c7SKent Overstreet unsigned int pool_size, 1903917a38c7SKent Overstreet unsigned int front_pad, 1904917a38c7SKent Overstreet int flags) 1905917a38c7SKent Overstreet { 1906917a38c7SKent Overstreet unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec); 1907917a38c7SKent Overstreet 1908917a38c7SKent Overstreet bs->front_pad = front_pad; 1909917a38c7SKent Overstreet 1910917a38c7SKent Overstreet spin_lock_init(&bs->rescue_lock); 1911917a38c7SKent Overstreet bio_list_init(&bs->rescue_list); 1912917a38c7SKent Overstreet INIT_WORK(&bs->rescue_work, bio_alloc_rescue); 1913917a38c7SKent Overstreet 1914917a38c7SKent Overstreet bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad); 1915917a38c7SKent Overstreet if (!bs->bio_slab) 1916917a38c7SKent Overstreet return -ENOMEM; 1917917a38c7SKent Overstreet 1918917a38c7SKent Overstreet if (mempool_init_slab_pool(&bs->bio_pool, pool_size, bs->bio_slab)) 1919917a38c7SKent Overstreet goto bad; 1920917a38c7SKent Overstreet 1921917a38c7SKent Overstreet if ((flags & BIOSET_NEED_BVECS) && 1922917a38c7SKent Overstreet biovec_init_pool(&bs->bvec_pool, pool_size)) 1923917a38c7SKent Overstreet goto bad; 1924917a38c7SKent Overstreet 1925917a38c7SKent Overstreet if (!(flags & BIOSET_NEED_RESCUER)) 1926917a38c7SKent Overstreet return 0; 1927917a38c7SKent Overstreet 1928917a38c7SKent Overstreet bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0); 1929917a38c7SKent Overstreet if (!bs->rescue_workqueue) 1930917a38c7SKent Overstreet goto bad; 1931917a38c7SKent Overstreet 1932917a38c7SKent Overstreet return 0; 1933917a38c7SKent Overstreet bad: 1934917a38c7SKent Overstreet bioset_exit(bs); 1935917a38c7SKent Overstreet return -ENOMEM; 1936917a38c7SKent Overstreet } 1937917a38c7SKent Overstreet EXPORT_SYMBOL(bioset_init); 1938917a38c7SKent Overstreet 193928e89fd9SJens Axboe /* 194028e89fd9SJens Axboe * Initialize and setup a new bio_set, based on the settings from 194128e89fd9SJens Axboe * another bio_set. 194228e89fd9SJens Axboe */ 194328e89fd9SJens Axboe int bioset_init_from_src(struct bio_set *bs, struct bio_set *src) 194428e89fd9SJens Axboe { 194528e89fd9SJens Axboe int flags; 194628e89fd9SJens Axboe 194728e89fd9SJens Axboe flags = 0; 194828e89fd9SJens Axboe if (src->bvec_pool.min_nr) 194928e89fd9SJens Axboe flags |= BIOSET_NEED_BVECS; 195028e89fd9SJens Axboe if (src->rescue_workqueue) 195128e89fd9SJens Axboe flags |= BIOSET_NEED_RESCUER; 195228e89fd9SJens Axboe 195328e89fd9SJens Axboe return bioset_init(bs, src->bio_pool.min_nr, src->front_pad, flags); 195428e89fd9SJens Axboe } 195528e89fd9SJens Axboe EXPORT_SYMBOL(bioset_init_from_src); 195628e89fd9SJens Axboe 1957f9c78b2bSJens Axboe #ifdef CONFIG_BLK_CGROUP 19581d933cf0STejun Heo 1959b5f2954dSDennis Zhou #ifdef CONFIG_MEMCG 19601d933cf0STejun Heo /** 1961b5f2954dSDennis Zhou * bio_associate_blkcg_from_page - associate a bio with the page's blkcg 1962b5f2954dSDennis Zhou * @bio: target bio 1963b5f2954dSDennis Zhou * @page: the page to lookup the blkcg from 1964b5f2954dSDennis Zhou * 1965b5f2954dSDennis Zhou * Associate @bio with the blkcg from @page's owning memcg. This works like 1966b5f2954dSDennis Zhou * every other associate function wrt references. 1967b5f2954dSDennis Zhou */ 1968b5f2954dSDennis Zhou int bio_associate_blkcg_from_page(struct bio *bio, struct page *page) 1969b5f2954dSDennis Zhou { 1970b5f2954dSDennis Zhou struct cgroup_subsys_state *blkcg_css; 1971b5f2954dSDennis Zhou 1972b5f2954dSDennis Zhou if (unlikely(bio->bi_css)) 1973b5f2954dSDennis Zhou return -EBUSY; 1974b5f2954dSDennis Zhou if (!page->mem_cgroup) 1975b5f2954dSDennis Zhou return 0; 1976b5f2954dSDennis Zhou blkcg_css = cgroup_get_e_css(page->mem_cgroup->css.cgroup, 1977b5f2954dSDennis Zhou &io_cgrp_subsys); 1978b5f2954dSDennis Zhou bio->bi_css = blkcg_css; 1979b5f2954dSDennis Zhou return 0; 1980b5f2954dSDennis Zhou } 1981b5f2954dSDennis Zhou #endif /* CONFIG_MEMCG */ 1982b5f2954dSDennis Zhou 1983b5f2954dSDennis Zhou /** 1984b5f2954dSDennis Zhou * bio_associate_blkcg - associate a bio with the specified blkcg 1985b5f2954dSDennis Zhou * @bio: target bio 1986b5f2954dSDennis Zhou * @blkcg_css: css of the blkcg to associate 1987b5f2954dSDennis Zhou * 1988b5f2954dSDennis Zhou * Associate @bio with the blkcg specified by @blkcg_css. Block layer will 1989b5f2954dSDennis Zhou * treat @bio as if it were issued by a task which belongs to the blkcg. 1990b5f2954dSDennis Zhou * 1991b5f2954dSDennis Zhou * This function takes an extra reference of @blkcg_css which will be put 1992b5f2954dSDennis Zhou * when @bio is released. The caller must own @bio and is responsible for 1993b5f2954dSDennis Zhou * synchronizing calls to this function. 1994b5f2954dSDennis Zhou */ 1995b5f2954dSDennis Zhou int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) 1996b5f2954dSDennis Zhou { 1997b5f2954dSDennis Zhou if (unlikely(bio->bi_css)) 1998b5f2954dSDennis Zhou return -EBUSY; 1999b5f2954dSDennis Zhou css_get(blkcg_css); 2000b5f2954dSDennis Zhou bio->bi_css = blkcg_css; 2001b5f2954dSDennis Zhou return 0; 2002b5f2954dSDennis Zhou } 2003b5f2954dSDennis Zhou EXPORT_SYMBOL_GPL(bio_associate_blkcg); 2004b5f2954dSDennis Zhou 2005b5f2954dSDennis Zhou /** 2006b5f2954dSDennis Zhou * bio_associate_blkg - associate a bio with the specified blkg 200708e18eabSJosef Bacik * @bio: target bio 200808e18eabSJosef Bacik * @blkg: the blkg to associate 200908e18eabSJosef Bacik * 2010b5f2954dSDennis Zhou * Associate @bio with the blkg specified by @blkg. This is the queue specific 2011b5f2954dSDennis Zhou * blkcg information associated with the @bio, a reference will be taken on the 2012b5f2954dSDennis Zhou * @blkg and will be freed when the bio is freed. 201308e18eabSJosef Bacik */ 201408e18eabSJosef Bacik int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg) 201508e18eabSJosef Bacik { 201608e18eabSJosef Bacik if (unlikely(bio->bi_blkg)) 201708e18eabSJosef Bacik return -EBUSY; 2018b5f2954dSDennis Zhou if (!blkg_try_get(blkg)) 2019b5f2954dSDennis Zhou return -ENODEV; 2020b5f2954dSDennis Zhou bio->bi_blkg = blkg; 202108e18eabSJosef Bacik return 0; 202208e18eabSJosef Bacik } 202308e18eabSJosef Bacik 2024f0fcb3ecSDennis Zhou (Facebook) /** 2025f9c78b2bSJens Axboe * bio_disassociate_task - undo bio_associate_current() 2026f9c78b2bSJens Axboe * @bio: target bio 2027f9c78b2bSJens Axboe */ 2028f9c78b2bSJens Axboe void bio_disassociate_task(struct bio *bio) 2029f9c78b2bSJens Axboe { 2030f9c78b2bSJens Axboe if (bio->bi_ioc) { 2031f9c78b2bSJens Axboe put_io_context(bio->bi_ioc); 2032f9c78b2bSJens Axboe bio->bi_ioc = NULL; 2033f9c78b2bSJens Axboe } 2034b5f2954dSDennis Zhou if (bio->bi_css) { 2035b5f2954dSDennis Zhou css_put(bio->bi_css); 2036b5f2954dSDennis Zhou bio->bi_css = NULL; 2037b5f2954dSDennis Zhou } 203808e18eabSJosef Bacik if (bio->bi_blkg) { 203908e18eabSJosef Bacik blkg_put(bio->bi_blkg); 204008e18eabSJosef Bacik bio->bi_blkg = NULL; 204108e18eabSJosef Bacik } 2042f9c78b2bSJens Axboe } 2043f9c78b2bSJens Axboe 204420bd723eSPaolo Valente /** 2045b5f2954dSDennis Zhou * bio_clone_blkcg_association - clone blkcg association from src to dst bio 204620bd723eSPaolo Valente * @dst: destination bio 204720bd723eSPaolo Valente * @src: source bio 204820bd723eSPaolo Valente */ 2049b5f2954dSDennis Zhou void bio_clone_blkcg_association(struct bio *dst, struct bio *src) 205020bd723eSPaolo Valente { 2051b5f2954dSDennis Zhou if (src->bi_css) 2052b5f2954dSDennis Zhou WARN_ON(bio_associate_blkcg(dst, src->bi_css)); 205320bd723eSPaolo Valente } 2054b5f2954dSDennis Zhou EXPORT_SYMBOL_GPL(bio_clone_blkcg_association); 2055f9c78b2bSJens Axboe #endif /* CONFIG_BLK_CGROUP */ 2056f9c78b2bSJens Axboe 2057f9c78b2bSJens Axboe static void __init biovec_init_slabs(void) 2058f9c78b2bSJens Axboe { 2059f9c78b2bSJens Axboe int i; 2060f9c78b2bSJens Axboe 2061ed996a52SChristoph Hellwig for (i = 0; i < BVEC_POOL_NR; i++) { 2062f9c78b2bSJens Axboe int size; 2063f9c78b2bSJens Axboe struct biovec_slab *bvs = bvec_slabs + i; 2064f9c78b2bSJens Axboe 2065f9c78b2bSJens Axboe if (bvs->nr_vecs <= BIO_INLINE_VECS) { 2066f9c78b2bSJens Axboe bvs->slab = NULL; 2067f9c78b2bSJens Axboe continue; 2068f9c78b2bSJens Axboe } 2069f9c78b2bSJens Axboe 2070f9c78b2bSJens Axboe size = bvs->nr_vecs * sizeof(struct bio_vec); 2071f9c78b2bSJens Axboe bvs->slab = kmem_cache_create(bvs->name, size, 0, 2072f9c78b2bSJens Axboe SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 2073f9c78b2bSJens Axboe } 2074f9c78b2bSJens Axboe } 2075f9c78b2bSJens Axboe 2076f9c78b2bSJens Axboe static int __init init_bio(void) 2077f9c78b2bSJens Axboe { 2078f9c78b2bSJens Axboe bio_slab_max = 2; 2079f9c78b2bSJens Axboe bio_slab_nr = 0; 20806396bb22SKees Cook bio_slabs = kcalloc(bio_slab_max, sizeof(struct bio_slab), 20816396bb22SKees Cook GFP_KERNEL); 2082f9c78b2bSJens Axboe if (!bio_slabs) 2083f9c78b2bSJens Axboe panic("bio: can't allocate bios\n"); 2084f9c78b2bSJens Axboe 2085f9c78b2bSJens Axboe bio_integrity_init(); 2086f9c78b2bSJens Axboe biovec_init_slabs(); 2087f9c78b2bSJens Axboe 2088f4f8154aSKent Overstreet if (bioset_init(&fs_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS)) 2089f9c78b2bSJens Axboe panic("bio: can't allocate bios\n"); 2090f9c78b2bSJens Axboe 2091f4f8154aSKent Overstreet if (bioset_integrity_create(&fs_bio_set, BIO_POOL_SIZE)) 2092f9c78b2bSJens Axboe panic("bio: can't create integrity pool\n"); 2093f9c78b2bSJens Axboe 2094f9c78b2bSJens Axboe return 0; 2095f9c78b2bSJens Axboe } 2096f9c78b2bSJens Axboe subsys_initcall(init_bio); 2097