Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Jens Axboe | 0fe2347 | 2006-09-04 15:41:16 +0200 | [diff] [blame] | 2 | * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public Licens |
| 14 | * along with this program; if not, write to the Free Software |
| 15 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- |
| 16 | * |
| 17 | */ |
| 18 | #include <linux/mm.h> |
| 19 | #include <linux/swap.h> |
| 20 | #include <linux/bio.h> |
| 21 | #include <linux/blkdev.h> |
| 22 | #include <linux/slab.h> |
| 23 | #include <linux/init.h> |
| 24 | #include <linux/kernel.h> |
| 25 | #include <linux/module.h> |
| 26 | #include <linux/mempool.h> |
| 27 | #include <linux/workqueue.h> |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 28 | #include <linux/blktrace_api.h> |
Arnaldo Carvalho de Melo | 5f3ea37 | 2008-10-30 08:34:33 +0100 | [diff] [blame] | 29 | #include <trace/block.h> |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 30 | #include <scsi/sg.h> /* for struct sg_iovec */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | |
Ingo Molnar | 0bfc245 | 2008-11-26 11:59:56 +0100 | [diff] [blame] | 32 | DEFINE_TRACE(block_split); |
| 33 | |
Jens Axboe | 392ddc3 | 2008-12-23 12:42:54 +0100 | [diff] [blame] | 34 | /* |
| 35 | * Test patch to inline a certain number of bi_io_vec's inside the bio |
| 36 | * itself, to shrink a bio data allocation from two mempool calls to one |
| 37 | */ |
| 38 | #define BIO_INLINE_VECS 4 |
| 39 | |
Denis ChengRq | 6feef53 | 2008-10-09 08:57:05 +0200 | [diff] [blame] | 40 | static mempool_t *bio_split_pool __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | /* |
| 43 | * if you change this list, also change bvec_alloc or things will |
| 44 | * break badly! cannot be bigger than what you can fit into an |
| 45 | * unsigned short |
| 46 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | #define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) } |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 48 | struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES), |
| 50 | }; |
| 51 | #undef BV |
| 52 | |
| 53 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | * fs_bio_set is the bio_set containing bio and iovec memory pools used by |
| 55 | * IO code that does not need private memory pools. |
| 56 | */ |
Martin K. Petersen | 51d654e | 2008-06-17 18:59:56 +0200 | [diff] [blame] | 57 | struct bio_set *fs_bio_set; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 59 | /* |
| 60 | * Our slab pool management |
| 61 | */ |
| 62 | struct bio_slab { |
| 63 | struct kmem_cache *slab; |
| 64 | unsigned int slab_ref; |
| 65 | unsigned int slab_size; |
| 66 | char name[8]; |
| 67 | }; |
| 68 | static DEFINE_MUTEX(bio_slab_lock); |
| 69 | static struct bio_slab *bio_slabs; |
| 70 | static unsigned int bio_slab_nr, bio_slab_max; |
| 71 | |
| 72 | static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size) |
| 73 | { |
| 74 | unsigned int sz = sizeof(struct bio) + extra_size; |
| 75 | struct kmem_cache *slab = NULL; |
| 76 | struct bio_slab *bslab; |
| 77 | unsigned int i, entry = -1; |
| 78 | |
| 79 | mutex_lock(&bio_slab_lock); |
| 80 | |
| 81 | i = 0; |
| 82 | while (i < bio_slab_nr) { |
| 83 | struct bio_slab *bslab = &bio_slabs[i]; |
| 84 | |
| 85 | if (!bslab->slab && entry == -1) |
| 86 | entry = i; |
| 87 | else if (bslab->slab_size == sz) { |
| 88 | slab = bslab->slab; |
| 89 | bslab->slab_ref++; |
| 90 | break; |
| 91 | } |
| 92 | i++; |
| 93 | } |
| 94 | |
| 95 | if (slab) |
| 96 | goto out_unlock; |
| 97 | |
| 98 | if (bio_slab_nr == bio_slab_max && entry == -1) { |
| 99 | bio_slab_max <<= 1; |
| 100 | bio_slabs = krealloc(bio_slabs, |
| 101 | bio_slab_max * sizeof(struct bio_slab), |
| 102 | GFP_KERNEL); |
| 103 | if (!bio_slabs) |
| 104 | goto out_unlock; |
| 105 | } |
| 106 | if (entry == -1) |
| 107 | entry = bio_slab_nr++; |
| 108 | |
| 109 | bslab = &bio_slabs[entry]; |
| 110 | |
| 111 | snprintf(bslab->name, sizeof(bslab->name), "bio-%d", entry); |
| 112 | slab = kmem_cache_create(bslab->name, sz, 0, SLAB_HWCACHE_ALIGN, NULL); |
| 113 | if (!slab) |
| 114 | goto out_unlock; |
| 115 | |
| 116 | printk("bio: create slab <%s> at %d\n", bslab->name, entry); |
| 117 | bslab->slab = slab; |
| 118 | bslab->slab_ref = 1; |
| 119 | bslab->slab_size = sz; |
| 120 | out_unlock: |
| 121 | mutex_unlock(&bio_slab_lock); |
| 122 | return slab; |
| 123 | } |
| 124 | |
| 125 | static void bio_put_slab(struct bio_set *bs) |
| 126 | { |
| 127 | struct bio_slab *bslab = NULL; |
| 128 | unsigned int i; |
| 129 | |
| 130 | mutex_lock(&bio_slab_lock); |
| 131 | |
| 132 | for (i = 0; i < bio_slab_nr; i++) { |
| 133 | if (bs->bio_slab == bio_slabs[i].slab) { |
| 134 | bslab = &bio_slabs[i]; |
| 135 | break; |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n")) |
| 140 | goto out; |
| 141 | |
| 142 | WARN_ON(!bslab->slab_ref); |
| 143 | |
| 144 | if (--bslab->slab_ref) |
| 145 | goto out; |
| 146 | |
| 147 | kmem_cache_destroy(bslab->slab); |
| 148 | bslab->slab = NULL; |
| 149 | |
| 150 | out: |
| 151 | mutex_unlock(&bio_slab_lock); |
| 152 | } |
| 153 | |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 154 | unsigned int bvec_nr_vecs(unsigned short idx) |
| 155 | { |
| 156 | return bvec_slabs[idx].nr_vecs; |
| 157 | } |
| 158 | |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 159 | void bvec_free_bs(struct bio_set *bs, struct bio_vec *bv, unsigned int idx) |
| 160 | { |
| 161 | BIO_BUG_ON(idx >= BIOVEC_NR_POOLS); |
| 162 | |
| 163 | if (idx == BIOVEC_MAX_IDX) |
| 164 | mempool_free(bv, bs->bvec_pool); |
| 165 | else { |
| 166 | struct biovec_slab *bvs = bvec_slabs + idx; |
| 167 | |
| 168 | kmem_cache_free(bvs->slab, bv); |
| 169 | } |
| 170 | } |
| 171 | |
Jens Axboe | 7ff9345 | 2008-12-11 11:53:43 +0100 | [diff] [blame] | 172 | struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, |
| 173 | struct bio_set *bs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | { |
| 175 | struct bio_vec *bvl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | |
| 177 | /* |
Jens Axboe | 7ff9345 | 2008-12-11 11:53:43 +0100 | [diff] [blame] | 178 | * see comment near bvec_array define! |
| 179 | */ |
| 180 | switch (nr) { |
| 181 | case 1: |
| 182 | *idx = 0; |
| 183 | break; |
| 184 | case 2 ... 4: |
| 185 | *idx = 1; |
| 186 | break; |
| 187 | case 5 ... 16: |
| 188 | *idx = 2; |
| 189 | break; |
| 190 | case 17 ... 64: |
| 191 | *idx = 3; |
| 192 | break; |
| 193 | case 65 ... 128: |
| 194 | *idx = 4; |
| 195 | break; |
| 196 | case 129 ... BIO_MAX_PAGES: |
| 197 | *idx = 5; |
| 198 | break; |
| 199 | default: |
| 200 | return NULL; |
| 201 | } |
| 202 | |
| 203 | /* |
| 204 | * idx now points to the pool we want to allocate from. only the |
| 205 | * 1-vec entry pool is mempool backed. |
| 206 | */ |
| 207 | if (*idx == BIOVEC_MAX_IDX) { |
| 208 | fallback: |
| 209 | bvl = mempool_alloc(bs->bvec_pool, gfp_mask); |
| 210 | } else { |
| 211 | struct biovec_slab *bvs = bvec_slabs + *idx; |
| 212 | gfp_t __gfp_mask = gfp_mask & ~(__GFP_WAIT | __GFP_IO); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | |
Jens Axboe | 0a0d96b | 2008-09-11 13:17:37 +0200 | [diff] [blame] | 214 | /* |
Jens Axboe | 7ff9345 | 2008-12-11 11:53:43 +0100 | [diff] [blame] | 215 | * Make this allocation restricted and don't dump info on |
| 216 | * allocation failures, since we'll fallback to the mempool |
| 217 | * in case of failure. |
Jens Axboe | 0a0d96b | 2008-09-11 13:17:37 +0200 | [diff] [blame] | 218 | */ |
Jens Axboe | 7ff9345 | 2008-12-11 11:53:43 +0100 | [diff] [blame] | 219 | __gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; |
| 220 | |
| 221 | /* |
| 222 | * Try a slab allocation. If this fails and __GFP_WAIT |
| 223 | * is set, retry with the 1-entry mempool |
| 224 | */ |
| 225 | bvl = kmem_cache_alloc(bvs->slab, __gfp_mask); |
| 226 | if (unlikely(!bvl && (gfp_mask & __GFP_WAIT))) { |
| 227 | *idx = BIOVEC_MAX_IDX; |
| 228 | goto fallback; |
| 229 | } |
| 230 | } |
| 231 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | return bvl; |
| 233 | } |
| 234 | |
Jens Axboe | 7ff9345 | 2008-12-11 11:53:43 +0100 | [diff] [blame] | 235 | void bio_free(struct bio *bio, struct bio_set *bs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | { |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 237 | void *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | |
Jens Axboe | 392ddc3 | 2008-12-23 12:42:54 +0100 | [diff] [blame] | 239 | if (bio_has_allocated_vec(bio)) |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 240 | bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio)); |
Jens Axboe | 992c5dd | 2007-07-18 13:18:08 +0200 | [diff] [blame] | 241 | |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 242 | if (bio_integrity(bio)) |
Martin K. Petersen | 6d2a78e | 2009-03-10 08:27:39 +0100 | [diff] [blame] | 243 | bio_integrity_free(bio); |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 244 | |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 245 | /* |
| 246 | * If we have front padding, adjust the bio pointer before freeing |
| 247 | */ |
| 248 | p = bio; |
| 249 | if (bs->front_pad) |
| 250 | p -= bs->front_pad; |
| 251 | |
| 252 | mempool_free(p, bs->bio_pool); |
Peter Osterlund | 3676347 | 2005-09-06 15:16:42 -0700 | [diff] [blame] | 253 | } |
| 254 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 255 | void bio_init(struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | { |
Jens Axboe | 2b94de5 | 2007-07-18 13:14:03 +0200 | [diff] [blame] | 257 | memset(bio, 0, sizeof(*bio)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | bio->bi_flags = 1 << BIO_UPTODATE; |
Jens Axboe | c7c22e4 | 2008-09-13 20:26:01 +0200 | [diff] [blame] | 259 | bio->bi_comp_cpu = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | atomic_set(&bio->bi_cnt, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | } |
| 262 | |
| 263 | /** |
| 264 | * bio_alloc_bioset - allocate a bio for I/O |
| 265 | * @gfp_mask: the GFP_ mask given to the slab allocator |
| 266 | * @nr_iovecs: number of iovecs to pre-allocate |
Jens Axboe | 0a0d96b | 2008-09-11 13:17:37 +0200 | [diff] [blame] | 267 | * @bs: the bio_set to allocate from. If %NULL, just use kmalloc |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | * |
| 269 | * Description: |
Jens Axboe | 0a0d96b | 2008-09-11 13:17:37 +0200 | [diff] [blame] | 270 | * bio_alloc_bioset will first try its own mempool to satisfy the allocation. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | * If %__GFP_WAIT is set then we will block on the internal pool waiting |
Jens Axboe | 0a0d96b | 2008-09-11 13:17:37 +0200 | [diff] [blame] | 272 | * for a &struct bio to become free. If a %NULL @bs is passed in, we will |
| 273 | * fall back to just using @kmalloc to allocate the required memory. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | * |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 275 | * Note that the caller must set ->bi_destructor on succesful return |
| 276 | * of a bio, to do the appropriate freeing of the bio once the reference |
| 277 | * count drops to zero. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | **/ |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 279 | struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | { |
Tejun Heo | 451a9eb | 2009-04-15 19:50:51 +0200 | [diff] [blame] | 281 | unsigned long idx = BIO_POOL_NONE; |
Ingo Molnar | 3405397 | 2009-02-21 11:16:36 +0100 | [diff] [blame] | 282 | struct bio_vec *bvl = NULL; |
Tejun Heo | 451a9eb | 2009-04-15 19:50:51 +0200 | [diff] [blame] | 283 | struct bio *bio; |
| 284 | void *p; |
Jens Axboe | 0a0d96b | 2008-09-11 13:17:37 +0200 | [diff] [blame] | 285 | |
Tejun Heo | 451a9eb | 2009-04-15 19:50:51 +0200 | [diff] [blame] | 286 | p = mempool_alloc(bs->bio_pool, gfp_mask); |
| 287 | if (unlikely(!p)) |
| 288 | return NULL; |
| 289 | bio = p + bs->front_pad; |
Ingo Molnar | 3405397 | 2009-02-21 11:16:36 +0100 | [diff] [blame] | 290 | |
| 291 | bio_init(bio); |
| 292 | |
| 293 | if (unlikely(!nr_iovecs)) |
| 294 | goto out_set; |
| 295 | |
| 296 | if (nr_iovecs <= BIO_INLINE_VECS) { |
| 297 | bvl = bio->bi_inline_vecs; |
| 298 | nr_iovecs = BIO_INLINE_VECS; |
| 299 | } else { |
| 300 | bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs); |
| 301 | if (unlikely(!bvl)) |
| 302 | goto err_free; |
| 303 | |
| 304 | nr_iovecs = bvec_nr_vecs(idx); |
| 305 | } |
Tejun Heo | 451a9eb | 2009-04-15 19:50:51 +0200 | [diff] [blame] | 306 | out_set: |
Ingo Molnar | 3405397 | 2009-02-21 11:16:36 +0100 | [diff] [blame] | 307 | bio->bi_flags |= idx << BIO_POOL_OFFSET; |
| 308 | bio->bi_max_vecs = nr_iovecs; |
Ingo Molnar | 3405397 | 2009-02-21 11:16:36 +0100 | [diff] [blame] | 309 | bio->bi_io_vec = bvl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | return bio; |
Ingo Molnar | 3405397 | 2009-02-21 11:16:36 +0100 | [diff] [blame] | 311 | |
| 312 | err_free: |
Tejun Heo | 451a9eb | 2009-04-15 19:50:51 +0200 | [diff] [blame] | 313 | mempool_free(p, bs->bio_pool); |
Ingo Molnar | 3405397 | 2009-02-21 11:16:36 +0100 | [diff] [blame] | 314 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | } |
| 316 | |
Tejun Heo | 451a9eb | 2009-04-15 19:50:51 +0200 | [diff] [blame] | 317 | static void bio_fs_destructor(struct bio *bio) |
| 318 | { |
| 319 | bio_free(bio, fs_bio_set); |
| 320 | } |
| 321 | |
| 322 | /** |
| 323 | * bio_alloc - allocate a new bio, memory pool backed |
| 324 | * @gfp_mask: allocation mask to use |
| 325 | * @nr_iovecs: number of iovecs |
| 326 | * |
| 327 | * Allocate a new bio with @nr_iovecs bvecs. If @gfp_mask |
| 328 | * contains __GFP_WAIT, the allocation is guaranteed to succeed. |
| 329 | * |
| 330 | * RETURNS: |
| 331 | * Pointer to new bio on success, NULL on failure. |
| 332 | */ |
| 333 | struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs) |
| 334 | { |
| 335 | struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set); |
| 336 | |
| 337 | if (bio) |
| 338 | bio->bi_destructor = bio_fs_destructor; |
| 339 | |
| 340 | return bio; |
| 341 | } |
| 342 | |
| 343 | static void bio_kmalloc_destructor(struct bio *bio) |
| 344 | { |
| 345 | if (bio_integrity(bio)) |
| 346 | bio_integrity_free(bio); |
| 347 | kfree(bio); |
| 348 | } |
| 349 | |
Jens Axboe | 86c824b | 2009-04-15 09:00:07 +0200 | [diff] [blame] | 350 | /** |
| 351 | * bio_alloc - allocate a bio for I/O |
| 352 | * @gfp_mask: the GFP_ mask given to the slab allocator |
| 353 | * @nr_iovecs: number of iovecs to pre-allocate |
| 354 | * |
| 355 | * Description: |
| 356 | * bio_alloc will allocate a bio and associated bio_vec array that can hold |
| 357 | * at least @nr_iovecs entries. Allocations will be done from the |
| 358 | * fs_bio_set. Also see @bio_alloc_bioset. |
| 359 | * |
| 360 | * If %__GFP_WAIT is set, then bio_alloc will always be able to allocate |
| 361 | * a bio. This is due to the mempool guarantees. To make this work, callers |
| 362 | * must never allocate more than 1 bio at the time from this pool. Callers |
| 363 | * that need to allocate more than 1 bio must always submit the previously |
| 364 | * allocate bio for IO before attempting to allocate a new one. Failure to |
| 365 | * do so can cause livelocks under memory pressure. |
| 366 | * |
| 367 | **/ |
Jens Axboe | 0a0d96b | 2008-09-11 13:17:37 +0200 | [diff] [blame] | 368 | struct bio *bio_kmalloc(gfp_t gfp_mask, int nr_iovecs) |
| 369 | { |
Tejun Heo | 451a9eb | 2009-04-15 19:50:51 +0200 | [diff] [blame] | 370 | struct bio *bio; |
Jens Axboe | 0a0d96b | 2008-09-11 13:17:37 +0200 | [diff] [blame] | 371 | |
Tejun Heo | 451a9eb | 2009-04-15 19:50:51 +0200 | [diff] [blame] | 372 | bio = kmalloc(sizeof(struct bio) + nr_iovecs * sizeof(struct bio_vec), |
| 373 | gfp_mask); |
| 374 | if (unlikely(!bio)) |
| 375 | return NULL; |
| 376 | |
| 377 | bio_init(bio); |
| 378 | bio->bi_flags |= BIO_POOL_NONE << BIO_POOL_OFFSET; |
| 379 | bio->bi_max_vecs = nr_iovecs; |
| 380 | bio->bi_io_vec = bio->bi_inline_vecs; |
| 381 | bio->bi_destructor = bio_kmalloc_destructor; |
Jens Axboe | 0a0d96b | 2008-09-11 13:17:37 +0200 | [diff] [blame] | 382 | |
| 383 | return bio; |
| 384 | } |
| 385 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | void zero_fill_bio(struct bio *bio) |
| 387 | { |
| 388 | unsigned long flags; |
| 389 | struct bio_vec *bv; |
| 390 | int i; |
| 391 | |
| 392 | bio_for_each_segment(bv, bio, i) { |
| 393 | char *data = bvec_kmap_irq(bv, &flags); |
| 394 | memset(data, 0, bv->bv_len); |
| 395 | flush_dcache_page(bv->bv_page); |
| 396 | bvec_kunmap_irq(data, &flags); |
| 397 | } |
| 398 | } |
| 399 | EXPORT_SYMBOL(zero_fill_bio); |
| 400 | |
| 401 | /** |
| 402 | * bio_put - release a reference to a bio |
| 403 | * @bio: bio to release reference to |
| 404 | * |
| 405 | * Description: |
| 406 | * Put a reference to a &struct bio, either one you have gotten with |
| 407 | * bio_alloc or bio_get. The last put of a bio will free it. |
| 408 | **/ |
| 409 | void bio_put(struct bio *bio) |
| 410 | { |
| 411 | BIO_BUG_ON(!atomic_read(&bio->bi_cnt)); |
| 412 | |
| 413 | /* |
| 414 | * last put frees it |
| 415 | */ |
| 416 | if (atomic_dec_and_test(&bio->bi_cnt)) { |
| 417 | bio->bi_next = NULL; |
| 418 | bio->bi_destructor(bio); |
| 419 | } |
| 420 | } |
| 421 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 422 | inline int bio_phys_segments(struct request_queue *q, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | { |
| 424 | if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) |
| 425 | blk_recount_segments(q, bio); |
| 426 | |
| 427 | return bio->bi_phys_segments; |
| 428 | } |
| 429 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | /** |
| 431 | * __bio_clone - clone a bio |
| 432 | * @bio: destination bio |
| 433 | * @bio_src: bio to clone |
| 434 | * |
| 435 | * Clone a &bio. Caller will own the returned bio, but not |
| 436 | * the actual data it points to. Reference count of returned |
| 437 | * bio will be one. |
| 438 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 439 | void __bio_clone(struct bio *bio, struct bio *bio_src) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | { |
Andrew Morton | e525e15 | 2005-08-07 09:42:12 -0700 | [diff] [blame] | 441 | memcpy(bio->bi_io_vec, bio_src->bi_io_vec, |
| 442 | bio_src->bi_max_vecs * sizeof(struct bio_vec)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | |
Jens Axboe | 5d84070 | 2008-01-25 12:44:44 +0100 | [diff] [blame] | 444 | /* |
| 445 | * most users will be overriding ->bi_bdev with a new target, |
| 446 | * so we don't set nor calculate new physical/hw segment counts here |
| 447 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | bio->bi_sector = bio_src->bi_sector; |
| 449 | bio->bi_bdev = bio_src->bi_bdev; |
| 450 | bio->bi_flags |= 1 << BIO_CLONED; |
| 451 | bio->bi_rw = bio_src->bi_rw; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | bio->bi_vcnt = bio_src->bi_vcnt; |
| 453 | bio->bi_size = bio_src->bi_size; |
Andrew Morton | a5453be | 2005-07-28 01:07:18 -0700 | [diff] [blame] | 454 | bio->bi_idx = bio_src->bi_idx; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | } |
| 456 | |
| 457 | /** |
| 458 | * bio_clone - clone a bio |
| 459 | * @bio: bio to clone |
| 460 | * @gfp_mask: allocation priority |
| 461 | * |
| 462 | * Like __bio_clone, only also allocates the returned bio |
| 463 | */ |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 464 | struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | { |
| 466 | struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set); |
| 467 | |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 468 | if (!b) |
| 469 | return NULL; |
| 470 | |
| 471 | b->bi_destructor = bio_fs_destructor; |
| 472 | __bio_clone(b, bio); |
| 473 | |
| 474 | if (bio_integrity(bio)) { |
| 475 | int ret; |
| 476 | |
Martin K. Petersen | 6d2a78e | 2009-03-10 08:27:39 +0100 | [diff] [blame] | 477 | ret = bio_integrity_clone(b, bio, gfp_mask); |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 478 | |
Li Zefan | 059ea33 | 2009-03-09 10:42:45 +0100 | [diff] [blame] | 479 | if (ret < 0) { |
| 480 | bio_put(b); |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 481 | return NULL; |
Li Zefan | 059ea33 | 2009-03-09 10:42:45 +0100 | [diff] [blame] | 482 | } |
Peter Osterlund | 3676347 | 2005-09-06 15:16:42 -0700 | [diff] [blame] | 483 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | |
| 485 | return b; |
| 486 | } |
| 487 | |
| 488 | /** |
| 489 | * bio_get_nr_vecs - return approx number of vecs |
| 490 | * @bdev: I/O target |
| 491 | * |
| 492 | * Return the approximate number of pages we can send to this target. |
| 493 | * There's no guarantee that you will be able to fit this number of pages |
| 494 | * into a bio, it does not account for dynamic restrictions that vary |
| 495 | * on offset. |
| 496 | */ |
| 497 | int bio_get_nr_vecs(struct block_device *bdev) |
| 498 | { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 499 | struct request_queue *q = bdev_get_queue(bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | int nr_pages; |
| 501 | |
| 502 | nr_pages = ((q->max_sectors << 9) + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 503 | if (nr_pages > q->max_phys_segments) |
| 504 | nr_pages = q->max_phys_segments; |
| 505 | if (nr_pages > q->max_hw_segments) |
| 506 | nr_pages = q->max_hw_segments; |
| 507 | |
| 508 | return nr_pages; |
| 509 | } |
| 510 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 511 | static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page |
Mike Christie | defd94b | 2005-12-05 02:37:06 -0600 | [diff] [blame] | 512 | *page, unsigned int len, unsigned int offset, |
| 513 | unsigned short max_sectors) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | { |
| 515 | int retried_segments = 0; |
| 516 | struct bio_vec *bvec; |
| 517 | |
| 518 | /* |
| 519 | * cloned bio must not modify vec list |
| 520 | */ |
| 521 | if (unlikely(bio_flagged(bio, BIO_CLONED))) |
| 522 | return 0; |
| 523 | |
Jens Axboe | 80cfd54 | 2006-01-06 09:43:28 +0100 | [diff] [blame] | 524 | if (((bio->bi_size + len) >> 9) > max_sectors) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 525 | return 0; |
| 526 | |
Jens Axboe | 80cfd54 | 2006-01-06 09:43:28 +0100 | [diff] [blame] | 527 | /* |
| 528 | * For filesystems with a blocksize smaller than the pagesize |
| 529 | * we will often be called with the same page as last time and |
| 530 | * a consecutive offset. Optimize this special case. |
| 531 | */ |
| 532 | if (bio->bi_vcnt > 0) { |
| 533 | struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1]; |
| 534 | |
| 535 | if (page == prev->bv_page && |
| 536 | offset == prev->bv_offset + prev->bv_len) { |
| 537 | prev->bv_len += len; |
Alasdair G Kergon | cc371e6 | 2008-07-03 09:53:43 +0200 | [diff] [blame] | 538 | |
| 539 | if (q->merge_bvec_fn) { |
| 540 | struct bvec_merge_data bvm = { |
| 541 | .bi_bdev = bio->bi_bdev, |
| 542 | .bi_sector = bio->bi_sector, |
| 543 | .bi_size = bio->bi_size, |
| 544 | .bi_rw = bio->bi_rw, |
| 545 | }; |
| 546 | |
| 547 | if (q->merge_bvec_fn(q, &bvm, prev) < len) { |
| 548 | prev->bv_len -= len; |
| 549 | return 0; |
| 550 | } |
Jens Axboe | 80cfd54 | 2006-01-06 09:43:28 +0100 | [diff] [blame] | 551 | } |
| 552 | |
| 553 | goto done; |
| 554 | } |
| 555 | } |
| 556 | |
| 557 | if (bio->bi_vcnt >= bio->bi_max_vecs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | return 0; |
| 559 | |
| 560 | /* |
| 561 | * we might lose a segment or two here, but rather that than |
| 562 | * make this too complex. |
| 563 | */ |
| 564 | |
| 565 | while (bio->bi_phys_segments >= q->max_phys_segments |
Mikulas Patocka | 5df97b9 | 2008-08-15 10:20:02 +0200 | [diff] [blame] | 566 | || bio->bi_phys_segments >= q->max_hw_segments) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | |
| 568 | if (retried_segments) |
| 569 | return 0; |
| 570 | |
| 571 | retried_segments = 1; |
| 572 | blk_recount_segments(q, bio); |
| 573 | } |
| 574 | |
| 575 | /* |
| 576 | * setup the new entry, we might clear it again later if we |
| 577 | * cannot add the page |
| 578 | */ |
| 579 | bvec = &bio->bi_io_vec[bio->bi_vcnt]; |
| 580 | bvec->bv_page = page; |
| 581 | bvec->bv_len = len; |
| 582 | bvec->bv_offset = offset; |
| 583 | |
| 584 | /* |
| 585 | * if queue has other restrictions (eg varying max sector size |
| 586 | * depending on offset), it can specify a merge_bvec_fn in the |
| 587 | * queue to get further control |
| 588 | */ |
| 589 | if (q->merge_bvec_fn) { |
Alasdair G Kergon | cc371e6 | 2008-07-03 09:53:43 +0200 | [diff] [blame] | 590 | struct bvec_merge_data bvm = { |
| 591 | .bi_bdev = bio->bi_bdev, |
| 592 | .bi_sector = bio->bi_sector, |
| 593 | .bi_size = bio->bi_size, |
| 594 | .bi_rw = bio->bi_rw, |
| 595 | }; |
| 596 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 597 | /* |
| 598 | * merge_bvec_fn() returns number of bytes it can accept |
| 599 | * at this offset |
| 600 | */ |
Alasdair G Kergon | cc371e6 | 2008-07-03 09:53:43 +0200 | [diff] [blame] | 601 | if (q->merge_bvec_fn(q, &bvm, bvec) < len) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | bvec->bv_page = NULL; |
| 603 | bvec->bv_len = 0; |
| 604 | bvec->bv_offset = 0; |
| 605 | return 0; |
| 606 | } |
| 607 | } |
| 608 | |
| 609 | /* If we may be able to merge these biovecs, force a recount */ |
Mikulas Patocka | b8b3e16 | 2008-08-15 10:15:19 +0200 | [diff] [blame] | 610 | if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 611 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); |
| 612 | |
| 613 | bio->bi_vcnt++; |
| 614 | bio->bi_phys_segments++; |
Jens Axboe | 80cfd54 | 2006-01-06 09:43:28 +0100 | [diff] [blame] | 615 | done: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 616 | bio->bi_size += len; |
| 617 | return len; |
| 618 | } |
| 619 | |
| 620 | /** |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 621 | * bio_add_pc_page - attempt to add page to bio |
Jens Axboe | fddfdea | 2006-01-31 15:24:34 +0100 | [diff] [blame] | 622 | * @q: the target queue |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 623 | * @bio: destination bio |
| 624 | * @page: page to add |
| 625 | * @len: vec entry length |
| 626 | * @offset: vec entry offset |
| 627 | * |
| 628 | * Attempt to add a page to the bio_vec maplist. This can fail for a |
| 629 | * number of reasons, such as the bio being full or target block |
| 630 | * device limitations. The target block device must allow bio's |
| 631 | * smaller than PAGE_SIZE, so it is always possible to add a single |
| 632 | * page to an empty bio. This should only be used by REQ_PC bios. |
| 633 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 634 | int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page, |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 635 | unsigned int len, unsigned int offset) |
| 636 | { |
Mike Christie | defd94b | 2005-12-05 02:37:06 -0600 | [diff] [blame] | 637 | return __bio_add_page(q, bio, page, len, offset, q->max_hw_sectors); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 638 | } |
| 639 | |
| 640 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 641 | * bio_add_page - attempt to add page to bio |
| 642 | * @bio: destination bio |
| 643 | * @page: page to add |
| 644 | * @len: vec entry length |
| 645 | * @offset: vec entry offset |
| 646 | * |
| 647 | * Attempt to add a page to the bio_vec maplist. This can fail for a |
| 648 | * number of reasons, such as the bio being full or target block |
| 649 | * device limitations. The target block device must allow bio's |
| 650 | * smaller than PAGE_SIZE, so it is always possible to add a single |
| 651 | * page to an empty bio. |
| 652 | */ |
| 653 | int bio_add_page(struct bio *bio, struct page *page, unsigned int len, |
| 654 | unsigned int offset) |
| 655 | { |
Mike Christie | defd94b | 2005-12-05 02:37:06 -0600 | [diff] [blame] | 656 | struct request_queue *q = bdev_get_queue(bio->bi_bdev); |
| 657 | return __bio_add_page(q, bio, page, len, offset, q->max_sectors); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 658 | } |
| 659 | |
| 660 | struct bio_map_data { |
| 661 | struct bio_vec *iovecs; |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 662 | struct sg_iovec *sgvecs; |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 663 | int nr_sgvecs; |
| 664 | int is_our_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 665 | }; |
| 666 | |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 667 | static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio, |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 668 | struct sg_iovec *iov, int iov_count, |
| 669 | int is_our_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 670 | { |
| 671 | memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt); |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 672 | memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count); |
| 673 | bmd->nr_sgvecs = iov_count; |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 674 | bmd->is_our_pages = is_our_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | bio->bi_private = bmd; |
| 676 | } |
| 677 | |
| 678 | static void bio_free_map_data(struct bio_map_data *bmd) |
| 679 | { |
| 680 | kfree(bmd->iovecs); |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 681 | kfree(bmd->sgvecs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 682 | kfree(bmd); |
| 683 | } |
| 684 | |
FUJITA Tomonori | 76029ff | 2008-08-25 20:36:08 +0200 | [diff] [blame] | 685 | static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count, |
| 686 | gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | { |
FUJITA Tomonori | 76029ff | 2008-08-25 20:36:08 +0200 | [diff] [blame] | 688 | struct bio_map_data *bmd = kmalloc(sizeof(*bmd), gfp_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 689 | |
| 690 | if (!bmd) |
| 691 | return NULL; |
| 692 | |
FUJITA Tomonori | 76029ff | 2008-08-25 20:36:08 +0200 | [diff] [blame] | 693 | bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, gfp_mask); |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 694 | if (!bmd->iovecs) { |
| 695 | kfree(bmd); |
| 696 | return NULL; |
| 697 | } |
| 698 | |
FUJITA Tomonori | 76029ff | 2008-08-25 20:36:08 +0200 | [diff] [blame] | 699 | bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, gfp_mask); |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 700 | if (bmd->sgvecs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 701 | return bmd; |
| 702 | |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 703 | kfree(bmd->iovecs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | kfree(bmd); |
| 705 | return NULL; |
| 706 | } |
| 707 | |
FUJITA Tomonori | aefcc28 | 2008-08-25 20:36:08 +0200 | [diff] [blame] | 708 | static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs, |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 709 | struct sg_iovec *iov, int iov_count, int uncopy, |
| 710 | int do_free_page) |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 711 | { |
| 712 | int ret = 0, i; |
| 713 | struct bio_vec *bvec; |
| 714 | int iov_idx = 0; |
| 715 | unsigned int iov_off = 0; |
| 716 | int read = bio_data_dir(bio) == READ; |
| 717 | |
| 718 | __bio_for_each_segment(bvec, bio, i, 0) { |
| 719 | char *bv_addr = page_address(bvec->bv_page); |
FUJITA Tomonori | aefcc28 | 2008-08-25 20:36:08 +0200 | [diff] [blame] | 720 | unsigned int bv_len = iovecs[i].bv_len; |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 721 | |
| 722 | while (bv_len && iov_idx < iov_count) { |
| 723 | unsigned int bytes; |
| 724 | char *iov_addr; |
| 725 | |
| 726 | bytes = min_t(unsigned int, |
| 727 | iov[iov_idx].iov_len - iov_off, bv_len); |
| 728 | iov_addr = iov[iov_idx].iov_base + iov_off; |
| 729 | |
| 730 | if (!ret) { |
| 731 | if (!read && !uncopy) |
| 732 | ret = copy_from_user(bv_addr, iov_addr, |
| 733 | bytes); |
| 734 | if (read && uncopy) |
| 735 | ret = copy_to_user(iov_addr, bv_addr, |
| 736 | bytes); |
| 737 | |
| 738 | if (ret) |
| 739 | ret = -EFAULT; |
| 740 | } |
| 741 | |
| 742 | bv_len -= bytes; |
| 743 | bv_addr += bytes; |
| 744 | iov_addr += bytes; |
| 745 | iov_off += bytes; |
| 746 | |
| 747 | if (iov[iov_idx].iov_len == iov_off) { |
| 748 | iov_idx++; |
| 749 | iov_off = 0; |
| 750 | } |
| 751 | } |
| 752 | |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 753 | if (do_free_page) |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 754 | __free_page(bvec->bv_page); |
| 755 | } |
| 756 | |
| 757 | return ret; |
| 758 | } |
| 759 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | /** |
| 761 | * bio_uncopy_user - finish previously mapped bio |
| 762 | * @bio: bio being terminated |
| 763 | * |
| 764 | * Free pages allocated from bio_copy_user() and write back data |
| 765 | * to user space in case of a read. |
| 766 | */ |
| 767 | int bio_uncopy_user(struct bio *bio) |
| 768 | { |
| 769 | struct bio_map_data *bmd = bio->bi_private; |
FUJITA Tomonori | 8188276 | 2008-09-02 16:20:19 +0900 | [diff] [blame] | 770 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | |
FUJITA Tomonori | 8188276 | 2008-09-02 16:20:19 +0900 | [diff] [blame] | 772 | if (!bio_flagged(bio, BIO_NULL_MAPPED)) |
| 773 | ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs, |
| 774 | bmd->nr_sgvecs, 1, bmd->is_our_pages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 775 | bio_free_map_data(bmd); |
| 776 | bio_put(bio); |
| 777 | return ret; |
| 778 | } |
| 779 | |
| 780 | /** |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 781 | * bio_copy_user_iov - copy user data to bio |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | * @q: destination block queue |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 783 | * @map_data: pointer to the rq_map_data holding pages (if necessary) |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 784 | * @iov: the iovec. |
| 785 | * @iov_count: number of elements in the iovec |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | * @write_to_vm: bool indicating writing to pages or not |
FUJITA Tomonori | a3bce90 | 2008-08-28 16:17:05 +0900 | [diff] [blame] | 787 | * @gfp_mask: memory allocation flags |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 788 | * |
| 789 | * Prepares and returns a bio for indirect user io, bouncing data |
| 790 | * to/from kernel pages as necessary. Must be paired with |
| 791 | * call bio_uncopy_user() on io completion. |
| 792 | */ |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 793 | struct bio *bio_copy_user_iov(struct request_queue *q, |
| 794 | struct rq_map_data *map_data, |
| 795 | struct sg_iovec *iov, int iov_count, |
| 796 | int write_to_vm, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 797 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | struct bio_map_data *bmd; |
| 799 | struct bio_vec *bvec; |
| 800 | struct page *page; |
| 801 | struct bio *bio; |
| 802 | int i, ret; |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 803 | int nr_pages = 0; |
| 804 | unsigned int len = 0; |
FUJITA Tomonori | 56c451f | 2008-12-18 14:49:37 +0900 | [diff] [blame] | 805 | unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 806 | |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 807 | for (i = 0; i < iov_count; i++) { |
| 808 | unsigned long uaddr; |
| 809 | unsigned long end; |
| 810 | unsigned long start; |
| 811 | |
| 812 | uaddr = (unsigned long)iov[i].iov_base; |
| 813 | end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 814 | start = uaddr >> PAGE_SHIFT; |
| 815 | |
| 816 | nr_pages += end - start; |
| 817 | len += iov[i].iov_len; |
| 818 | } |
| 819 | |
FUJITA Tomonori | a3bce90 | 2008-08-28 16:17:05 +0900 | [diff] [blame] | 820 | bmd = bio_alloc_map_data(nr_pages, iov_count, gfp_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 821 | if (!bmd) |
| 822 | return ERR_PTR(-ENOMEM); |
| 823 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 824 | ret = -ENOMEM; |
Tejun Heo | a9e9dc2 | 2009-04-15 22:10:27 +0900 | [diff] [blame^] | 825 | bio = bio_kmalloc(gfp_mask, nr_pages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 826 | if (!bio) |
| 827 | goto out_bmd; |
| 828 | |
| 829 | bio->bi_rw |= (!write_to_vm << BIO_RW); |
| 830 | |
| 831 | ret = 0; |
FUJITA Tomonori | 56c451f | 2008-12-18 14:49:37 +0900 | [diff] [blame] | 832 | |
| 833 | if (map_data) { |
FUJITA Tomonori | e623ddb | 2008-12-18 14:49:36 +0900 | [diff] [blame] | 834 | nr_pages = 1 << map_data->page_order; |
FUJITA Tomonori | 56c451f | 2008-12-18 14:49:37 +0900 | [diff] [blame] | 835 | i = map_data->offset / PAGE_SIZE; |
| 836 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 837 | while (len) { |
FUJITA Tomonori | e623ddb | 2008-12-18 14:49:36 +0900 | [diff] [blame] | 838 | unsigned int bytes = PAGE_SIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 839 | |
FUJITA Tomonori | 56c451f | 2008-12-18 14:49:37 +0900 | [diff] [blame] | 840 | bytes -= offset; |
| 841 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 842 | if (bytes > len) |
| 843 | bytes = len; |
| 844 | |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 845 | if (map_data) { |
FUJITA Tomonori | e623ddb | 2008-12-18 14:49:36 +0900 | [diff] [blame] | 846 | if (i == map_data->nr_entries * nr_pages) { |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 847 | ret = -ENOMEM; |
| 848 | break; |
| 849 | } |
FUJITA Tomonori | e623ddb | 2008-12-18 14:49:36 +0900 | [diff] [blame] | 850 | |
| 851 | page = map_data->pages[i / nr_pages]; |
| 852 | page += (i % nr_pages); |
| 853 | |
| 854 | i++; |
| 855 | } else { |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 856 | page = alloc_page(q->bounce_gfp | gfp_mask); |
FUJITA Tomonori | e623ddb | 2008-12-18 14:49:36 +0900 | [diff] [blame] | 857 | if (!page) { |
| 858 | ret = -ENOMEM; |
| 859 | break; |
| 860 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 861 | } |
| 862 | |
FUJITA Tomonori | 56c451f | 2008-12-18 14:49:37 +0900 | [diff] [blame] | 863 | if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 864 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 865 | |
| 866 | len -= bytes; |
FUJITA Tomonori | 56c451f | 2008-12-18 14:49:37 +0900 | [diff] [blame] | 867 | offset = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 868 | } |
| 869 | |
| 870 | if (ret) |
| 871 | goto cleanup; |
| 872 | |
| 873 | /* |
| 874 | * success |
| 875 | */ |
FUJITA Tomonori | 97ae77a | 2008-12-18 14:49:38 +0900 | [diff] [blame] | 876 | if (!write_to_vm && (!map_data || !map_data->null_mapped)) { |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 877 | ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 0); |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 878 | if (ret) |
| 879 | goto cleanup; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 880 | } |
| 881 | |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 882 | bio_set_map_data(bmd, bio, iov, iov_count, map_data ? 0 : 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 883 | return bio; |
| 884 | cleanup: |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 885 | if (!map_data) |
| 886 | bio_for_each_segment(bvec, bio, i) |
| 887 | __free_page(bvec->bv_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 888 | |
| 889 | bio_put(bio); |
| 890 | out_bmd: |
| 891 | bio_free_map_data(bmd); |
| 892 | return ERR_PTR(ret); |
| 893 | } |
| 894 | |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 895 | /** |
| 896 | * bio_copy_user - copy user data to bio |
| 897 | * @q: destination block queue |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 898 | * @map_data: pointer to the rq_map_data holding pages (if necessary) |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 899 | * @uaddr: start of user address |
| 900 | * @len: length in bytes |
| 901 | * @write_to_vm: bool indicating writing to pages or not |
FUJITA Tomonori | a3bce90 | 2008-08-28 16:17:05 +0900 | [diff] [blame] | 902 | * @gfp_mask: memory allocation flags |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 903 | * |
| 904 | * Prepares and returns a bio for indirect user io, bouncing data |
| 905 | * to/from kernel pages as necessary. Must be paired with |
| 906 | * call bio_uncopy_user() on io completion. |
| 907 | */ |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 908 | struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data, |
| 909 | unsigned long uaddr, unsigned int len, |
| 910 | int write_to_vm, gfp_t gfp_mask) |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 911 | { |
| 912 | struct sg_iovec iov; |
| 913 | |
| 914 | iov.iov_base = (void __user *)uaddr; |
| 915 | iov.iov_len = len; |
| 916 | |
FUJITA Tomonori | 152e283 | 2008-08-28 16:17:06 +0900 | [diff] [blame] | 917 | return bio_copy_user_iov(q, map_data, &iov, 1, write_to_vm, gfp_mask); |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 918 | } |
| 919 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 920 | static struct bio *__bio_map_user_iov(struct request_queue *q, |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 921 | struct block_device *bdev, |
| 922 | struct sg_iovec *iov, int iov_count, |
FUJITA Tomonori | a3bce90 | 2008-08-28 16:17:05 +0900 | [diff] [blame] | 923 | int write_to_vm, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 924 | { |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 925 | int i, j; |
| 926 | int nr_pages = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 927 | struct page **pages; |
| 928 | struct bio *bio; |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 929 | int cur_page = 0; |
| 930 | int ret, offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 931 | |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 932 | for (i = 0; i < iov_count; i++) { |
| 933 | unsigned long uaddr = (unsigned long)iov[i].iov_base; |
| 934 | unsigned long len = iov[i].iov_len; |
| 935 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 936 | unsigned long start = uaddr >> PAGE_SHIFT; |
| 937 | |
| 938 | nr_pages += end - start; |
| 939 | /* |
Mike Christie | ad2d722 | 2006-12-01 10:40:20 +0100 | [diff] [blame] | 940 | * buffer must be aligned to at least hardsector size for now |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 941 | */ |
Mike Christie | ad2d722 | 2006-12-01 10:40:20 +0100 | [diff] [blame] | 942 | if (uaddr & queue_dma_alignment(q)) |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 943 | return ERR_PTR(-EINVAL); |
| 944 | } |
| 945 | |
| 946 | if (!nr_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 947 | return ERR_PTR(-EINVAL); |
| 948 | |
Tejun Heo | a9e9dc2 | 2009-04-15 22:10:27 +0900 | [diff] [blame^] | 949 | bio = bio_kmalloc(gfp_mask, nr_pages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 950 | if (!bio) |
| 951 | return ERR_PTR(-ENOMEM); |
| 952 | |
| 953 | ret = -ENOMEM; |
FUJITA Tomonori | a3bce90 | 2008-08-28 16:17:05 +0900 | [diff] [blame] | 954 | pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 955 | if (!pages) |
| 956 | goto out; |
| 957 | |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 958 | for (i = 0; i < iov_count; i++) { |
| 959 | unsigned long uaddr = (unsigned long)iov[i].iov_base; |
| 960 | unsigned long len = iov[i].iov_len; |
| 961 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 962 | unsigned long start = uaddr >> PAGE_SHIFT; |
| 963 | const int local_nr_pages = end - start; |
| 964 | const int page_limit = cur_page + local_nr_pages; |
| 965 | |
Nick Piggin | f5dd33c | 2008-07-25 19:45:25 -0700 | [diff] [blame] | 966 | ret = get_user_pages_fast(uaddr, local_nr_pages, |
| 967 | write_to_vm, &pages[cur_page]); |
Jens Axboe | 9917215 | 2006-06-16 13:02:29 +0200 | [diff] [blame] | 968 | if (ret < local_nr_pages) { |
| 969 | ret = -EFAULT; |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 970 | goto out_unmap; |
Jens Axboe | 9917215 | 2006-06-16 13:02:29 +0200 | [diff] [blame] | 971 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 972 | |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 973 | offset = uaddr & ~PAGE_MASK; |
| 974 | for (j = cur_page; j < page_limit; j++) { |
| 975 | unsigned int bytes = PAGE_SIZE - offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 977 | if (len <= 0) |
| 978 | break; |
| 979 | |
| 980 | if (bytes > len) |
| 981 | bytes = len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 982 | |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 983 | /* |
| 984 | * sorry... |
| 985 | */ |
Mike Christie | defd94b | 2005-12-05 02:37:06 -0600 | [diff] [blame] | 986 | if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < |
| 987 | bytes) |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 988 | break; |
| 989 | |
| 990 | len -= bytes; |
| 991 | offset = 0; |
| 992 | } |
| 993 | |
| 994 | cur_page = j; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 995 | /* |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 996 | * release the pages we didn't map into the bio, if any |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 997 | */ |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 998 | while (j < page_limit) |
| 999 | page_cache_release(pages[j++]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1000 | } |
| 1001 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1002 | kfree(pages); |
| 1003 | |
| 1004 | /* |
| 1005 | * set data direction, and check if mapped pages need bouncing |
| 1006 | */ |
| 1007 | if (!write_to_vm) |
| 1008 | bio->bi_rw |= (1 << BIO_RW); |
| 1009 | |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 1010 | bio->bi_bdev = bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | bio->bi_flags |= (1 << BIO_USER_MAPPED); |
| 1012 | return bio; |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 1013 | |
| 1014 | out_unmap: |
| 1015 | for (i = 0; i < nr_pages; i++) { |
| 1016 | if(!pages[i]) |
| 1017 | break; |
| 1018 | page_cache_release(pages[i]); |
| 1019 | } |
| 1020 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1021 | kfree(pages); |
| 1022 | bio_put(bio); |
| 1023 | return ERR_PTR(ret); |
| 1024 | } |
| 1025 | |
| 1026 | /** |
| 1027 | * bio_map_user - map user address into bio |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1028 | * @q: the struct request_queue for the bio |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1029 | * @bdev: destination block device |
| 1030 | * @uaddr: start of user address |
| 1031 | * @len: length in bytes |
| 1032 | * @write_to_vm: bool indicating writing to pages or not |
FUJITA Tomonori | a3bce90 | 2008-08-28 16:17:05 +0900 | [diff] [blame] | 1033 | * @gfp_mask: memory allocation flags |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1034 | * |
| 1035 | * Map the user space address into a bio suitable for io to a block |
| 1036 | * device. Returns an error pointer in case of error. |
| 1037 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1038 | struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev, |
FUJITA Tomonori | a3bce90 | 2008-08-28 16:17:05 +0900 | [diff] [blame] | 1039 | unsigned long uaddr, unsigned int len, int write_to_vm, |
| 1040 | gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1041 | { |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 1042 | struct sg_iovec iov; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1043 | |
viro@ZenIV.linux.org.uk | 3f70353 | 2005-09-09 16:53:56 +0100 | [diff] [blame] | 1044 | iov.iov_base = (void __user *)uaddr; |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 1045 | iov.iov_len = len; |
| 1046 | |
FUJITA Tomonori | a3bce90 | 2008-08-28 16:17:05 +0900 | [diff] [blame] | 1047 | return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask); |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 1048 | } |
| 1049 | |
| 1050 | /** |
| 1051 | * bio_map_user_iov - map user sg_iovec table into bio |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1052 | * @q: the struct request_queue for the bio |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 1053 | * @bdev: destination block device |
| 1054 | * @iov: the iovec. |
| 1055 | * @iov_count: number of elements in the iovec |
| 1056 | * @write_to_vm: bool indicating writing to pages or not |
FUJITA Tomonori | a3bce90 | 2008-08-28 16:17:05 +0900 | [diff] [blame] | 1057 | * @gfp_mask: memory allocation flags |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 1058 | * |
| 1059 | * Map the user space address into a bio suitable for io to a block |
| 1060 | * device. Returns an error pointer in case of error. |
| 1061 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1062 | struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev, |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 1063 | struct sg_iovec *iov, int iov_count, |
FUJITA Tomonori | a3bce90 | 2008-08-28 16:17:05 +0900 | [diff] [blame] | 1064 | int write_to_vm, gfp_t gfp_mask) |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 1065 | { |
| 1066 | struct bio *bio; |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 1067 | |
FUJITA Tomonori | a3bce90 | 2008-08-28 16:17:05 +0900 | [diff] [blame] | 1068 | bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm, |
| 1069 | gfp_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1070 | if (IS_ERR(bio)) |
| 1071 | return bio; |
| 1072 | |
| 1073 | /* |
| 1074 | * subtle -- if __bio_map_user() ended up bouncing a bio, |
| 1075 | * it would normally disappear when its bi_end_io is run. |
| 1076 | * however, we need it for the unmap, so grab an extra |
| 1077 | * reference to it |
| 1078 | */ |
| 1079 | bio_get(bio); |
| 1080 | |
Mike Christie | 0e75f90 | 2006-12-01 10:40:55 +0100 | [diff] [blame] | 1081 | return bio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1082 | } |
| 1083 | |
| 1084 | static void __bio_unmap_user(struct bio *bio) |
| 1085 | { |
| 1086 | struct bio_vec *bvec; |
| 1087 | int i; |
| 1088 | |
| 1089 | /* |
| 1090 | * make sure we dirty pages we wrote to |
| 1091 | */ |
| 1092 | __bio_for_each_segment(bvec, bio, i, 0) { |
| 1093 | if (bio_data_dir(bio) == READ) |
| 1094 | set_page_dirty_lock(bvec->bv_page); |
| 1095 | |
| 1096 | page_cache_release(bvec->bv_page); |
| 1097 | } |
| 1098 | |
| 1099 | bio_put(bio); |
| 1100 | } |
| 1101 | |
| 1102 | /** |
| 1103 | * bio_unmap_user - unmap a bio |
| 1104 | * @bio: the bio being unmapped |
| 1105 | * |
| 1106 | * Unmap a bio previously mapped by bio_map_user(). Must be called with |
| 1107 | * a process context. |
| 1108 | * |
| 1109 | * bio_unmap_user() may sleep. |
| 1110 | */ |
| 1111 | void bio_unmap_user(struct bio *bio) |
| 1112 | { |
| 1113 | __bio_unmap_user(bio); |
| 1114 | bio_put(bio); |
| 1115 | } |
| 1116 | |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 1117 | static void bio_map_kern_endio(struct bio *bio, int err) |
Jens Axboe | b823825 | 2005-06-20 14:05:27 +0200 | [diff] [blame] | 1118 | { |
Jens Axboe | b823825 | 2005-06-20 14:05:27 +0200 | [diff] [blame] | 1119 | bio_put(bio); |
Jens Axboe | b823825 | 2005-06-20 14:05:27 +0200 | [diff] [blame] | 1120 | } |
| 1121 | |
| 1122 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1123 | static struct bio *__bio_map_kern(struct request_queue *q, void *data, |
Al Viro | 27496a8 | 2005-10-21 03:20:48 -0400 | [diff] [blame] | 1124 | unsigned int len, gfp_t gfp_mask) |
Mike Christie | df46b9a | 2005-06-20 14:04:44 +0200 | [diff] [blame] | 1125 | { |
| 1126 | unsigned long kaddr = (unsigned long)data; |
| 1127 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 1128 | unsigned long start = kaddr >> PAGE_SHIFT; |
| 1129 | const int nr_pages = end - start; |
| 1130 | int offset, i; |
| 1131 | struct bio *bio; |
| 1132 | |
Tejun Heo | a9e9dc2 | 2009-04-15 22:10:27 +0900 | [diff] [blame^] | 1133 | bio = bio_kmalloc(gfp_mask, nr_pages); |
Mike Christie | df46b9a | 2005-06-20 14:04:44 +0200 | [diff] [blame] | 1134 | if (!bio) |
| 1135 | return ERR_PTR(-ENOMEM); |
| 1136 | |
| 1137 | offset = offset_in_page(kaddr); |
| 1138 | for (i = 0; i < nr_pages; i++) { |
| 1139 | unsigned int bytes = PAGE_SIZE - offset; |
| 1140 | |
| 1141 | if (len <= 0) |
| 1142 | break; |
| 1143 | |
| 1144 | if (bytes > len) |
| 1145 | bytes = len; |
| 1146 | |
Mike Christie | defd94b | 2005-12-05 02:37:06 -0600 | [diff] [blame] | 1147 | if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, |
| 1148 | offset) < bytes) |
Mike Christie | df46b9a | 2005-06-20 14:04:44 +0200 | [diff] [blame] | 1149 | break; |
| 1150 | |
| 1151 | data += bytes; |
| 1152 | len -= bytes; |
| 1153 | offset = 0; |
| 1154 | } |
| 1155 | |
Jens Axboe | b823825 | 2005-06-20 14:05:27 +0200 | [diff] [blame] | 1156 | bio->bi_end_io = bio_map_kern_endio; |
Mike Christie | df46b9a | 2005-06-20 14:04:44 +0200 | [diff] [blame] | 1157 | return bio; |
| 1158 | } |
| 1159 | |
| 1160 | /** |
| 1161 | * bio_map_kern - map kernel address into bio |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1162 | * @q: the struct request_queue for the bio |
Mike Christie | df46b9a | 2005-06-20 14:04:44 +0200 | [diff] [blame] | 1163 | * @data: pointer to buffer to map |
| 1164 | * @len: length in bytes |
| 1165 | * @gfp_mask: allocation flags for bio allocation |
| 1166 | * |
| 1167 | * Map the kernel address into a bio suitable for io to a block |
| 1168 | * device. Returns an error pointer in case of error. |
| 1169 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1170 | struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len, |
Al Viro | 27496a8 | 2005-10-21 03:20:48 -0400 | [diff] [blame] | 1171 | gfp_t gfp_mask) |
Mike Christie | df46b9a | 2005-06-20 14:04:44 +0200 | [diff] [blame] | 1172 | { |
| 1173 | struct bio *bio; |
| 1174 | |
| 1175 | bio = __bio_map_kern(q, data, len, gfp_mask); |
| 1176 | if (IS_ERR(bio)) |
| 1177 | return bio; |
| 1178 | |
| 1179 | if (bio->bi_size == len) |
| 1180 | return bio; |
| 1181 | |
| 1182 | /* |
| 1183 | * Don't support partial mappings. |
| 1184 | */ |
| 1185 | bio_put(bio); |
| 1186 | return ERR_PTR(-EINVAL); |
| 1187 | } |
| 1188 | |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1189 | static void bio_copy_kern_endio(struct bio *bio, int err) |
| 1190 | { |
| 1191 | struct bio_vec *bvec; |
| 1192 | const int read = bio_data_dir(bio) == READ; |
FUJITA Tomonori | 76029ff | 2008-08-25 20:36:08 +0200 | [diff] [blame] | 1193 | struct bio_map_data *bmd = bio->bi_private; |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1194 | int i; |
FUJITA Tomonori | 76029ff | 2008-08-25 20:36:08 +0200 | [diff] [blame] | 1195 | char *p = bmd->sgvecs[0].iov_base; |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1196 | |
| 1197 | __bio_for_each_segment(bvec, bio, i, 0) { |
| 1198 | char *addr = page_address(bvec->bv_page); |
FUJITA Tomonori | 76029ff | 2008-08-25 20:36:08 +0200 | [diff] [blame] | 1199 | int len = bmd->iovecs[i].bv_len; |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1200 | |
| 1201 | if (read && !err) |
FUJITA Tomonori | 76029ff | 2008-08-25 20:36:08 +0200 | [diff] [blame] | 1202 | memcpy(p, addr, len); |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1203 | |
| 1204 | __free_page(bvec->bv_page); |
FUJITA Tomonori | 76029ff | 2008-08-25 20:36:08 +0200 | [diff] [blame] | 1205 | p += len; |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1206 | } |
| 1207 | |
FUJITA Tomonori | 76029ff | 2008-08-25 20:36:08 +0200 | [diff] [blame] | 1208 | bio_free_map_data(bmd); |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1209 | bio_put(bio); |
| 1210 | } |
| 1211 | |
| 1212 | /** |
| 1213 | * bio_copy_kern - copy kernel address into bio |
| 1214 | * @q: the struct request_queue for the bio |
| 1215 | * @data: pointer to buffer to copy |
| 1216 | * @len: length in bytes |
| 1217 | * @gfp_mask: allocation flags for bio and page allocation |
Randy Dunlap | ffee025 | 2008-04-30 09:08:54 +0200 | [diff] [blame] | 1218 | * @reading: data direction is READ |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1219 | * |
| 1220 | * copy the kernel address into a bio suitable for io to a block |
| 1221 | * device. Returns an error pointer in case of error. |
| 1222 | */ |
| 1223 | struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, |
| 1224 | gfp_t gfp_mask, int reading) |
| 1225 | { |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1226 | struct bio *bio; |
| 1227 | struct bio_vec *bvec; |
FUJITA Tomonori | 4d8ab62 | 2008-08-28 15:05:57 +0900 | [diff] [blame] | 1228 | int i; |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1229 | |
FUJITA Tomonori | 4d8ab62 | 2008-08-28 15:05:57 +0900 | [diff] [blame] | 1230 | bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask); |
| 1231 | if (IS_ERR(bio)) |
| 1232 | return bio; |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1233 | |
| 1234 | if (!reading) { |
| 1235 | void *p = data; |
| 1236 | |
| 1237 | bio_for_each_segment(bvec, bio, i) { |
| 1238 | char *addr = page_address(bvec->bv_page); |
| 1239 | |
| 1240 | memcpy(addr, p, bvec->bv_len); |
| 1241 | p += bvec->bv_len; |
| 1242 | } |
| 1243 | } |
| 1244 | |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1245 | bio->bi_end_io = bio_copy_kern_endio; |
FUJITA Tomonori | 76029ff | 2008-08-25 20:36:08 +0200 | [diff] [blame] | 1246 | |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1247 | return bio; |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1248 | } |
| 1249 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1250 | /* |
| 1251 | * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions |
| 1252 | * for performing direct-IO in BIOs. |
| 1253 | * |
| 1254 | * The problem is that we cannot run set_page_dirty() from interrupt context |
| 1255 | * because the required locks are not interrupt-safe. So what we can do is to |
| 1256 | * mark the pages dirty _before_ performing IO. And in interrupt context, |
| 1257 | * check that the pages are still dirty. If so, fine. If not, redirty them |
| 1258 | * in process context. |
| 1259 | * |
| 1260 | * We special-case compound pages here: normally this means reads into hugetlb |
| 1261 | * pages. The logic in here doesn't really work right for compound pages |
| 1262 | * because the VM does not uniformly chase down the head page in all cases. |
| 1263 | * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't |
| 1264 | * handle them at all. So we skip compound pages here at an early stage. |
| 1265 | * |
| 1266 | * Note that this code is very hard to test under normal circumstances because |
| 1267 | * direct-io pins the pages with get_user_pages(). This makes |
| 1268 | * is_page_cache_freeable return false, and the VM will not clean the pages. |
| 1269 | * But other code (eg, pdflush) could clean the pages if they are mapped |
| 1270 | * pagecache. |
| 1271 | * |
| 1272 | * Simply disabling the call to bio_set_pages_dirty() is a good way to test the |
| 1273 | * deferred bio dirtying paths. |
| 1274 | */ |
| 1275 | |
| 1276 | /* |
| 1277 | * bio_set_pages_dirty() will mark all the bio's pages as dirty. |
| 1278 | */ |
| 1279 | void bio_set_pages_dirty(struct bio *bio) |
| 1280 | { |
| 1281 | struct bio_vec *bvec = bio->bi_io_vec; |
| 1282 | int i; |
| 1283 | |
| 1284 | for (i = 0; i < bio->bi_vcnt; i++) { |
| 1285 | struct page *page = bvec[i].bv_page; |
| 1286 | |
| 1287 | if (page && !PageCompound(page)) |
| 1288 | set_page_dirty_lock(page); |
| 1289 | } |
| 1290 | } |
| 1291 | |
Adrian Bunk | 86b6c7a | 2008-02-18 13:48:32 +0100 | [diff] [blame] | 1292 | static void bio_release_pages(struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1293 | { |
| 1294 | struct bio_vec *bvec = bio->bi_io_vec; |
| 1295 | int i; |
| 1296 | |
| 1297 | for (i = 0; i < bio->bi_vcnt; i++) { |
| 1298 | struct page *page = bvec[i].bv_page; |
| 1299 | |
| 1300 | if (page) |
| 1301 | put_page(page); |
| 1302 | } |
| 1303 | } |
| 1304 | |
| 1305 | /* |
| 1306 | * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. |
| 1307 | * If they are, then fine. If, however, some pages are clean then they must |
| 1308 | * have been written out during the direct-IO read. So we take another ref on |
| 1309 | * the BIO and the offending pages and re-dirty the pages in process context. |
| 1310 | * |
| 1311 | * It is expected that bio_check_pages_dirty() will wholly own the BIO from |
| 1312 | * here on. It will run one page_cache_release() against each page and will |
| 1313 | * run one bio_put() against the BIO. |
| 1314 | */ |
| 1315 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 1316 | static void bio_dirty_fn(struct work_struct *work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1317 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 1318 | static DECLARE_WORK(bio_dirty_work, bio_dirty_fn); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1319 | static DEFINE_SPINLOCK(bio_dirty_lock); |
| 1320 | static struct bio *bio_dirty_list; |
| 1321 | |
| 1322 | /* |
| 1323 | * This runs in process context |
| 1324 | */ |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 1325 | static void bio_dirty_fn(struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1326 | { |
| 1327 | unsigned long flags; |
| 1328 | struct bio *bio; |
| 1329 | |
| 1330 | spin_lock_irqsave(&bio_dirty_lock, flags); |
| 1331 | bio = bio_dirty_list; |
| 1332 | bio_dirty_list = NULL; |
| 1333 | spin_unlock_irqrestore(&bio_dirty_lock, flags); |
| 1334 | |
| 1335 | while (bio) { |
| 1336 | struct bio *next = bio->bi_private; |
| 1337 | |
| 1338 | bio_set_pages_dirty(bio); |
| 1339 | bio_release_pages(bio); |
| 1340 | bio_put(bio); |
| 1341 | bio = next; |
| 1342 | } |
| 1343 | } |
| 1344 | |
| 1345 | void bio_check_pages_dirty(struct bio *bio) |
| 1346 | { |
| 1347 | struct bio_vec *bvec = bio->bi_io_vec; |
| 1348 | int nr_clean_pages = 0; |
| 1349 | int i; |
| 1350 | |
| 1351 | for (i = 0; i < bio->bi_vcnt; i++) { |
| 1352 | struct page *page = bvec[i].bv_page; |
| 1353 | |
| 1354 | if (PageDirty(page) || PageCompound(page)) { |
| 1355 | page_cache_release(page); |
| 1356 | bvec[i].bv_page = NULL; |
| 1357 | } else { |
| 1358 | nr_clean_pages++; |
| 1359 | } |
| 1360 | } |
| 1361 | |
| 1362 | if (nr_clean_pages) { |
| 1363 | unsigned long flags; |
| 1364 | |
| 1365 | spin_lock_irqsave(&bio_dirty_lock, flags); |
| 1366 | bio->bi_private = bio_dirty_list; |
| 1367 | bio_dirty_list = bio; |
| 1368 | spin_unlock_irqrestore(&bio_dirty_lock, flags); |
| 1369 | schedule_work(&bio_dirty_work); |
| 1370 | } else { |
| 1371 | bio_put(bio); |
| 1372 | } |
| 1373 | } |
| 1374 | |
| 1375 | /** |
| 1376 | * bio_endio - end I/O on a bio |
| 1377 | * @bio: bio |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1378 | * @error: error, if any |
| 1379 | * |
| 1380 | * Description: |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 1381 | * bio_endio() will end I/O on the whole bio. bio_endio() is the |
NeilBrown | 5bb23a6 | 2007-09-27 12:46:13 +0200 | [diff] [blame] | 1382 | * preferred way to end I/O on a bio, it takes care of clearing |
| 1383 | * BIO_UPTODATE on error. @error is 0 on success, and and one of the |
| 1384 | * established -Exxxx (-EIO, for instance) error values in case |
| 1385 | * something went wrong. Noone should call bi_end_io() directly on a |
| 1386 | * bio unless they own it and thus know that it has an end_io |
| 1387 | * function. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1388 | **/ |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 1389 | void bio_endio(struct bio *bio, int error) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1390 | { |
| 1391 | if (error) |
| 1392 | clear_bit(BIO_UPTODATE, &bio->bi_flags); |
NeilBrown | 9cc54d4 | 2007-09-27 12:46:12 +0200 | [diff] [blame] | 1393 | else if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) |
| 1394 | error = -EIO; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1395 | |
NeilBrown | 5bb23a6 | 2007-09-27 12:46:13 +0200 | [diff] [blame] | 1396 | if (bio->bi_end_io) |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 1397 | bio->bi_end_io(bio, error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1398 | } |
| 1399 | |
| 1400 | void bio_pair_release(struct bio_pair *bp) |
| 1401 | { |
| 1402 | if (atomic_dec_and_test(&bp->cnt)) { |
| 1403 | struct bio *master = bp->bio1.bi_private; |
| 1404 | |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 1405 | bio_endio(master, bp->error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1406 | mempool_free(bp, bp->bio2.bi_private); |
| 1407 | } |
| 1408 | } |
| 1409 | |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 1410 | static void bio_pair_end_1(struct bio *bi, int err) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1411 | { |
| 1412 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio1); |
| 1413 | |
| 1414 | if (err) |
| 1415 | bp->error = err; |
| 1416 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1417 | bio_pair_release(bp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1418 | } |
| 1419 | |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 1420 | static void bio_pair_end_2(struct bio *bi, int err) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1421 | { |
| 1422 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio2); |
| 1423 | |
| 1424 | if (err) |
| 1425 | bp->error = err; |
| 1426 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1427 | bio_pair_release(bp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1428 | } |
| 1429 | |
| 1430 | /* |
Alberto Bertogli | c7eee1b | 2009-01-25 23:36:14 -0200 | [diff] [blame] | 1431 | * split a bio - only worry about a bio with a single page in its iovec |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1432 | */ |
Denis ChengRq | 6feef53 | 2008-10-09 08:57:05 +0200 | [diff] [blame] | 1433 | struct bio_pair *bio_split(struct bio *bi, int first_sectors) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1434 | { |
Denis ChengRq | 6feef53 | 2008-10-09 08:57:05 +0200 | [diff] [blame] | 1435 | struct bio_pair *bp = mempool_alloc(bio_split_pool, GFP_NOIO); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1436 | |
| 1437 | if (!bp) |
| 1438 | return bp; |
| 1439 | |
Arnaldo Carvalho de Melo | 5f3ea37 | 2008-10-30 08:34:33 +0100 | [diff] [blame] | 1440 | trace_block_split(bdev_get_queue(bi->bi_bdev), bi, |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 1441 | bi->bi_sector + first_sectors); |
| 1442 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1443 | BUG_ON(bi->bi_vcnt != 1); |
| 1444 | BUG_ON(bi->bi_idx != 0); |
| 1445 | atomic_set(&bp->cnt, 3); |
| 1446 | bp->error = 0; |
| 1447 | bp->bio1 = *bi; |
| 1448 | bp->bio2 = *bi; |
| 1449 | bp->bio2.bi_sector += first_sectors; |
| 1450 | bp->bio2.bi_size -= first_sectors << 9; |
| 1451 | bp->bio1.bi_size = first_sectors << 9; |
| 1452 | |
| 1453 | bp->bv1 = bi->bi_io_vec[0]; |
| 1454 | bp->bv2 = bi->bi_io_vec[0]; |
| 1455 | bp->bv2.bv_offset += first_sectors << 9; |
| 1456 | bp->bv2.bv_len -= first_sectors << 9; |
| 1457 | bp->bv1.bv_len = first_sectors << 9; |
| 1458 | |
| 1459 | bp->bio1.bi_io_vec = &bp->bv1; |
| 1460 | bp->bio2.bi_io_vec = &bp->bv2; |
| 1461 | |
NeilBrown | a2eb0c1 | 2006-05-22 22:35:27 -0700 | [diff] [blame] | 1462 | bp->bio1.bi_max_vecs = 1; |
| 1463 | bp->bio2.bi_max_vecs = 1; |
| 1464 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1465 | bp->bio1.bi_end_io = bio_pair_end_1; |
| 1466 | bp->bio2.bi_end_io = bio_pair_end_2; |
| 1467 | |
| 1468 | bp->bio1.bi_private = bi; |
Denis ChengRq | 6feef53 | 2008-10-09 08:57:05 +0200 | [diff] [blame] | 1469 | bp->bio2.bi_private = bio_split_pool; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1470 | |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 1471 | if (bio_integrity(bi)) |
| 1472 | bio_integrity_split(bi, bp, first_sectors); |
| 1473 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1474 | return bp; |
| 1475 | } |
| 1476 | |
Martin K. Petersen | ad3316b | 2008-10-01 22:42:53 -0400 | [diff] [blame] | 1477 | /** |
| 1478 | * bio_sector_offset - Find hardware sector offset in bio |
| 1479 | * @bio: bio to inspect |
| 1480 | * @index: bio_vec index |
| 1481 | * @offset: offset in bv_page |
| 1482 | * |
| 1483 | * Return the number of hardware sectors between beginning of bio |
| 1484 | * and an end point indicated by a bio_vec index and an offset |
| 1485 | * within that vector's page. |
| 1486 | */ |
| 1487 | sector_t bio_sector_offset(struct bio *bio, unsigned short index, |
| 1488 | unsigned int offset) |
| 1489 | { |
| 1490 | unsigned int sector_sz = queue_hardsect_size(bio->bi_bdev->bd_disk->queue); |
| 1491 | struct bio_vec *bv; |
| 1492 | sector_t sectors; |
| 1493 | int i; |
| 1494 | |
| 1495 | sectors = 0; |
| 1496 | |
| 1497 | if (index >= bio->bi_idx) |
| 1498 | index = bio->bi_vcnt - 1; |
| 1499 | |
| 1500 | __bio_for_each_segment(bv, bio, i, 0) { |
| 1501 | if (i == index) { |
| 1502 | if (offset > bv->bv_offset) |
| 1503 | sectors += (offset - bv->bv_offset) / sector_sz; |
| 1504 | break; |
| 1505 | } |
| 1506 | |
| 1507 | sectors += bv->bv_len / sector_sz; |
| 1508 | } |
| 1509 | |
| 1510 | return sectors; |
| 1511 | } |
| 1512 | EXPORT_SYMBOL(bio_sector_offset); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1513 | |
| 1514 | /* |
| 1515 | * create memory pools for biovec's in a bio_set. |
| 1516 | * use the global biovec slabs created for general use. |
| 1517 | */ |
Jens Axboe | 5972511 | 2007-04-02 10:06:42 +0200 | [diff] [blame] | 1518 | static int biovec_create_pools(struct bio_set *bs, int pool_entries) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1519 | { |
Jens Axboe | 7ff9345 | 2008-12-11 11:53:43 +0100 | [diff] [blame] | 1520 | struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1521 | |
Jens Axboe | 7ff9345 | 2008-12-11 11:53:43 +0100 | [diff] [blame] | 1522 | bs->bvec_pool = mempool_create_slab_pool(pool_entries, bp->slab); |
| 1523 | if (!bs->bvec_pool) |
| 1524 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1525 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1526 | return 0; |
| 1527 | } |
| 1528 | |
| 1529 | static void biovec_free_pools(struct bio_set *bs) |
| 1530 | { |
Jens Axboe | 7ff9345 | 2008-12-11 11:53:43 +0100 | [diff] [blame] | 1531 | mempool_destroy(bs->bvec_pool); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1532 | } |
| 1533 | |
| 1534 | void bioset_free(struct bio_set *bs) |
| 1535 | { |
| 1536 | if (bs->bio_pool) |
| 1537 | mempool_destroy(bs->bio_pool); |
| 1538 | |
| 1539 | biovec_free_pools(bs); |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 1540 | bio_put_slab(bs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1541 | |
| 1542 | kfree(bs); |
| 1543 | } |
| 1544 | |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 1545 | /** |
| 1546 | * bioset_create - Create a bio_set |
| 1547 | * @pool_size: Number of bio and bio_vecs to cache in the mempool |
| 1548 | * @front_pad: Number of bytes to allocate in front of the returned bio |
| 1549 | * |
| 1550 | * Description: |
| 1551 | * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller |
| 1552 | * to ask for a number of bytes to be allocated in front of the bio. |
| 1553 | * Front pad allocation is useful for embedding the bio inside |
| 1554 | * another structure, to avoid allocating extra data to go with the bio. |
| 1555 | * Note that the bio must be embedded at the END of that structure always, |
| 1556 | * or things will break badly. |
| 1557 | */ |
| 1558 | struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1559 | { |
Jens Axboe | 392ddc3 | 2008-12-23 12:42:54 +0100 | [diff] [blame] | 1560 | unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec); |
Jens Axboe | 1b43449 | 2008-10-22 20:32:58 +0200 | [diff] [blame] | 1561 | struct bio_set *bs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1562 | |
Jens Axboe | 1b43449 | 2008-10-22 20:32:58 +0200 | [diff] [blame] | 1563 | bs = kzalloc(sizeof(*bs), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1564 | if (!bs) |
| 1565 | return NULL; |
| 1566 | |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 1567 | bs->front_pad = front_pad; |
Jens Axboe | 1b43449 | 2008-10-22 20:32:58 +0200 | [diff] [blame] | 1568 | |
Jens Axboe | 392ddc3 | 2008-12-23 12:42:54 +0100 | [diff] [blame] | 1569 | bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad); |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 1570 | if (!bs->bio_slab) { |
| 1571 | kfree(bs); |
| 1572 | return NULL; |
| 1573 | } |
| 1574 | |
| 1575 | bs->bio_pool = mempool_create_slab_pool(pool_size, bs->bio_slab); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1576 | if (!bs->bio_pool) |
| 1577 | goto bad; |
| 1578 | |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 1579 | if (!biovec_create_pools(bs, pool_size)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1580 | return bs; |
| 1581 | |
| 1582 | bad: |
| 1583 | bioset_free(bs); |
| 1584 | return NULL; |
| 1585 | } |
| 1586 | |
| 1587 | static void __init biovec_init_slabs(void) |
| 1588 | { |
| 1589 | int i; |
| 1590 | |
| 1591 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { |
| 1592 | int size; |
| 1593 | struct biovec_slab *bvs = bvec_slabs + i; |
| 1594 | |
Jens Axboe | a7fcd37 | 2008-12-05 16:10:29 +0100 | [diff] [blame] | 1595 | #ifndef CONFIG_BLK_DEV_INTEGRITY |
| 1596 | if (bvs->nr_vecs <= BIO_INLINE_VECS) { |
| 1597 | bvs->slab = NULL; |
| 1598 | continue; |
| 1599 | } |
| 1600 | #endif |
| 1601 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1602 | size = bvs->nr_vecs * sizeof(struct bio_vec); |
| 1603 | bvs->slab = kmem_cache_create(bvs->name, size, 0, |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1604 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1605 | } |
| 1606 | } |
| 1607 | |
| 1608 | static int __init init_bio(void) |
| 1609 | { |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 1610 | bio_slab_max = 2; |
| 1611 | bio_slab_nr = 0; |
| 1612 | bio_slabs = kzalloc(bio_slab_max * sizeof(struct bio_slab), GFP_KERNEL); |
| 1613 | if (!bio_slabs) |
| 1614 | panic("bio: can't allocate bios\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1615 | |
| 1616 | biovec_init_slabs(); |
| 1617 | |
Jens Axboe | bb799ca | 2008-12-10 15:35:05 +0100 | [diff] [blame] | 1618 | fs_bio_set = bioset_create(BIO_POOL_SIZE, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1619 | if (!fs_bio_set) |
| 1620 | panic("bio: can't allocate bios\n"); |
| 1621 | |
Matthew Dobson | 0eaae62a | 2006-03-26 01:37:47 -0800 | [diff] [blame] | 1622 | bio_split_pool = mempool_create_kmalloc_pool(BIO_SPLIT_ENTRIES, |
| 1623 | sizeof(struct bio_pair)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1624 | if (!bio_split_pool) |
| 1625 | panic("bio: can't create split pool\n"); |
| 1626 | |
| 1627 | return 0; |
| 1628 | } |
| 1629 | |
| 1630 | subsys_initcall(init_bio); |
| 1631 | |
| 1632 | EXPORT_SYMBOL(bio_alloc); |
Jens Axboe | 0a0d96b | 2008-09-11 13:17:37 +0200 | [diff] [blame] | 1633 | EXPORT_SYMBOL(bio_kmalloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1634 | EXPORT_SYMBOL(bio_put); |
Peter Osterlund | 3676347 | 2005-09-06 15:16:42 -0700 | [diff] [blame] | 1635 | EXPORT_SYMBOL(bio_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1636 | EXPORT_SYMBOL(bio_endio); |
| 1637 | EXPORT_SYMBOL(bio_init); |
| 1638 | EXPORT_SYMBOL(__bio_clone); |
| 1639 | EXPORT_SYMBOL(bio_clone); |
| 1640 | EXPORT_SYMBOL(bio_phys_segments); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1641 | EXPORT_SYMBOL(bio_add_page); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 1642 | EXPORT_SYMBOL(bio_add_pc_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1643 | EXPORT_SYMBOL(bio_get_nr_vecs); |
Jens Axboe | 40044ce | 2008-03-17 21:14:40 +0100 | [diff] [blame] | 1644 | EXPORT_SYMBOL(bio_map_user); |
| 1645 | EXPORT_SYMBOL(bio_unmap_user); |
Mike Christie | df46b9a | 2005-06-20 14:04:44 +0200 | [diff] [blame] | 1646 | EXPORT_SYMBOL(bio_map_kern); |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1647 | EXPORT_SYMBOL(bio_copy_kern); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1648 | EXPORT_SYMBOL(bio_pair_release); |
| 1649 | EXPORT_SYMBOL(bio_split); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1650 | EXPORT_SYMBOL(bio_copy_user); |
| 1651 | EXPORT_SYMBOL(bio_uncopy_user); |
| 1652 | EXPORT_SYMBOL(bioset_create); |
| 1653 | EXPORT_SYMBOL(bioset_free); |
| 1654 | EXPORT_SYMBOL(bio_alloc_bioset); |