| 1 | /* |
| 2 | * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk> |
| 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/iocontext.h> |
| 23 | #include <linux/slab.h> |
| 24 | #include <linux/init.h> |
| 25 | #include <linux/kernel.h> |
| 26 | #include <linux/export.h> |
| 27 | #include <linux/mempool.h> |
| 28 | #include <linux/workqueue.h> |
| 29 | #include <linux/cgroup.h> |
| 30 | #include <scsi/sg.h> /* for struct sg_iovec */ |
| 31 | |
| 32 | #include <trace/events/block.h> |
| 33 | |
| 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 | |
| 40 | static mempool_t *bio_split_pool __read_mostly; |
| 41 | |
| 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 | */ |
| 47 | #define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) } |
| 48 | static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { |
| 49 | BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES), |
| 50 | }; |
| 51 | #undef BV |
| 52 | |
| 53 | /* |
| 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 | */ |
| 57 | struct bio_set *fs_bio_set; |
| 58 | |
| 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 | 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(KERN_INFO "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 | |
| 154 | unsigned int bvec_nr_vecs(unsigned short idx) |
| 155 | { |
| 156 | return bvec_slabs[idx].nr_vecs; |
| 157 | } |
| 158 | |
| 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 | |
| 172 | struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, |
| 173 | struct bio_set *bs) |
| 174 | { |
| 175 | struct bio_vec *bvl; |
| 176 | |
| 177 | /* |
| 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); |
| 213 | |
| 214 | /* |
| 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. |
| 218 | */ |
| 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 | |
| 232 | return bvl; |
| 233 | } |
| 234 | |
| 235 | void bio_free(struct bio *bio, struct bio_set *bs) |
| 236 | { |
| 237 | void *p; |
| 238 | |
| 239 | if (bio_has_allocated_vec(bio)) |
| 240 | bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio)); |
| 241 | |
| 242 | if (bio_integrity(bio)) |
| 243 | bio_integrity_free(bio, bs); |
| 244 | |
| 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); |
| 253 | } |
| 254 | EXPORT_SYMBOL(bio_free); |
| 255 | |
| 256 | void bio_init(struct bio *bio) |
| 257 | { |
| 258 | memset(bio, 0, sizeof(*bio)); |
| 259 | bio->bi_flags = 1 << BIO_UPTODATE; |
| 260 | atomic_set(&bio->bi_cnt, 1); |
| 261 | } |
| 262 | EXPORT_SYMBOL(bio_init); |
| 263 | |
| 264 | /** |
| 265 | * bio_alloc_bioset - allocate a bio for I/O |
| 266 | * @gfp_mask: the GFP_ mask given to the slab allocator |
| 267 | * @nr_iovecs: number of iovecs to pre-allocate |
| 268 | * @bs: the bio_set to allocate from. |
| 269 | * |
| 270 | * Description: |
| 271 | * bio_alloc_bioset will try its own mempool to satisfy the allocation. |
| 272 | * If %__GFP_WAIT is set then we will block on the internal pool waiting |
| 273 | * for a &struct bio to become free. |
| 274 | * |
| 275 | * Note that the caller must set ->bi_destructor on successful return |
| 276 | * of a bio, to do the appropriate freeing of the bio once the reference |
| 277 | * count drops to zero. |
| 278 | **/ |
| 279 | struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) |
| 280 | { |
| 281 | unsigned long idx = BIO_POOL_NONE; |
| 282 | struct bio_vec *bvl = NULL; |
| 283 | struct bio *bio; |
| 284 | void *p; |
| 285 | |
| 286 | p = mempool_alloc(bs->bio_pool, gfp_mask); |
| 287 | if (unlikely(!p)) |
| 288 | return NULL; |
| 289 | bio = p + bs->front_pad; |
| 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 | } |
| 306 | out_set: |
| 307 | bio->bi_flags |= idx << BIO_POOL_OFFSET; |
| 308 | bio->bi_max_vecs = nr_iovecs; |
| 309 | bio->bi_io_vec = bvl; |
| 310 | return bio; |
| 311 | |
| 312 | err_free: |
| 313 | mempool_free(p, bs->bio_pool); |
| 314 | return NULL; |
| 315 | } |
| 316 | EXPORT_SYMBOL(bio_alloc_bioset); |
| 317 | |
| 318 | static void bio_fs_destructor(struct bio *bio) |
| 319 | { |
| 320 | bio_free(bio, fs_bio_set); |
| 321 | } |
| 322 | |
| 323 | /** |
| 324 | * bio_alloc - allocate a new bio, memory pool backed |
| 325 | * @gfp_mask: allocation mask to use |
| 326 | * @nr_iovecs: number of iovecs |
| 327 | * |
| 328 | * bio_alloc will allocate a bio and associated bio_vec array that can hold |
| 329 | * at least @nr_iovecs entries. Allocations will be done from the |
| 330 | * fs_bio_set. Also see @bio_alloc_bioset and @bio_kmalloc. |
| 331 | * |
| 332 | * If %__GFP_WAIT is set, then bio_alloc will always be able to allocate |
| 333 | * a bio. This is due to the mempool guarantees. To make this work, callers |
| 334 | * must never allocate more than 1 bio at a time from this pool. Callers |
| 335 | * that need to allocate more than 1 bio must always submit the previously |
| 336 | * allocated bio for IO before attempting to allocate a new one. Failure to |
| 337 | * do so can cause livelocks under memory pressure. |
| 338 | * |
| 339 | * RETURNS: |
| 340 | * Pointer to new bio on success, NULL on failure. |
| 341 | */ |
| 342 | struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) |
| 343 | { |
| 344 | struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set); |
| 345 | |
| 346 | if (bio) |
| 347 | bio->bi_destructor = bio_fs_destructor; |
| 348 | |
| 349 | return bio; |
| 350 | } |
| 351 | EXPORT_SYMBOL(bio_alloc); |
| 352 | |
| 353 | static void bio_kmalloc_destructor(struct bio *bio) |
| 354 | { |
| 355 | if (bio_integrity(bio)) |
| 356 | bio_integrity_free(bio, fs_bio_set); |
| 357 | kfree(bio); |
| 358 | } |
| 359 | |
| 360 | /** |
| 361 | * bio_kmalloc - allocate a bio for I/O using kmalloc() |
| 362 | * @gfp_mask: the GFP_ mask given to the slab allocator |
| 363 | * @nr_iovecs: number of iovecs to pre-allocate |
| 364 | * |
| 365 | * Description: |
| 366 | * Allocate a new bio with @nr_iovecs bvecs. If @gfp_mask contains |
| 367 | * %__GFP_WAIT, the allocation is guaranteed to succeed. |
| 368 | * |
| 369 | **/ |
| 370 | struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs) |
| 371 | { |
| 372 | struct bio *bio; |
| 373 | |
| 374 | if (nr_iovecs > UIO_MAXIOV) |
| 375 | return NULL; |
| 376 | |
| 377 | bio = kmalloc(sizeof(struct bio) + nr_iovecs * sizeof(struct bio_vec), |
| 378 | gfp_mask); |
| 379 | if (unlikely(!bio)) |
| 380 | return NULL; |
| 381 | |
| 382 | bio_init(bio); |
| 383 | bio->bi_flags |= BIO_POOL_NONE << BIO_POOL_OFFSET; |
| 384 | bio->bi_max_vecs = nr_iovecs; |
| 385 | bio->bi_io_vec = bio->bi_inline_vecs; |
| 386 | bio->bi_destructor = bio_kmalloc_destructor; |
| 387 | |
| 388 | return bio; |
| 389 | } |
| 390 | EXPORT_SYMBOL(bio_kmalloc); |
| 391 | |
| 392 | void zero_fill_bio(struct bio *bio) |
| 393 | { |
| 394 | unsigned long flags; |
| 395 | struct bio_vec *bv; |
| 396 | int i; |
| 397 | |
| 398 | bio_for_each_segment(bv, bio, i) { |
| 399 | char *data = bvec_kmap_irq(bv, &flags); |
| 400 | memset(data, 0, bv->bv_len); |
| 401 | flush_dcache_page(bv->bv_page); |
| 402 | bvec_kunmap_irq(data, &flags); |
| 403 | } |
| 404 | } |
| 405 | EXPORT_SYMBOL(zero_fill_bio); |
| 406 | |
| 407 | /** |
| 408 | * bio_put - release a reference to a bio |
| 409 | * @bio: bio to release reference to |
| 410 | * |
| 411 | * Description: |
| 412 | * Put a reference to a &struct bio, either one you have gotten with |
| 413 | * bio_alloc, bio_get or bio_clone. The last put of a bio will free it. |
| 414 | **/ |
| 415 | void bio_put(struct bio *bio) |
| 416 | { |
| 417 | BIO_BUG_ON(!atomic_read(&bio->bi_cnt)); |
| 418 | |
| 419 | /* |
| 420 | * last put frees it |
| 421 | */ |
| 422 | if (atomic_dec_and_test(&bio->bi_cnt)) { |
| 423 | bio_disassociate_task(bio); |
| 424 | bio->bi_next = NULL; |
| 425 | bio->bi_destructor(bio); |
| 426 | } |
| 427 | } |
| 428 | EXPORT_SYMBOL(bio_put); |
| 429 | |
| 430 | inline int bio_phys_segments(struct request_queue *q, struct bio *bio) |
| 431 | { |
| 432 | if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) |
| 433 | blk_recount_segments(q, bio); |
| 434 | |
| 435 | return bio->bi_phys_segments; |
| 436 | } |
| 437 | EXPORT_SYMBOL(bio_phys_segments); |
| 438 | |
| 439 | /** |
| 440 | * __bio_clone - clone a bio |
| 441 | * @bio: destination bio |
| 442 | * @bio_src: bio to clone |
| 443 | * |
| 444 | * Clone a &bio. Caller will own the returned bio, but not |
| 445 | * the actual data it points to. Reference count of returned |
| 446 | * bio will be one. |
| 447 | */ |
| 448 | void __bio_clone(struct bio *bio, struct bio *bio_src) |
| 449 | { |
| 450 | memcpy(bio->bi_io_vec, bio_src->bi_io_vec, |
| 451 | bio_src->bi_max_vecs * sizeof(struct bio_vec)); |
| 452 | |
| 453 | /* |
| 454 | * most users will be overriding ->bi_bdev with a new target, |
| 455 | * so we don't set nor calculate new physical/hw segment counts here |
| 456 | */ |
| 457 | bio->bi_sector = bio_src->bi_sector; |
| 458 | bio->bi_bdev = bio_src->bi_bdev; |
| 459 | bio->bi_flags |= 1 << BIO_CLONED; |
| 460 | bio->bi_rw = bio_src->bi_rw; |
| 461 | bio->bi_vcnt = bio_src->bi_vcnt; |
| 462 | bio->bi_size = bio_src->bi_size; |
| 463 | bio->bi_idx = bio_src->bi_idx; |
| 464 | } |
| 465 | EXPORT_SYMBOL(__bio_clone); |
| 466 | |
| 467 | /** |
| 468 | * bio_clone - clone a bio |
| 469 | * @bio: bio to clone |
| 470 | * @gfp_mask: allocation priority |
| 471 | * |
| 472 | * Like __bio_clone, only also allocates the returned bio |
| 473 | */ |
| 474 | struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) |
| 475 | { |
| 476 | struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set); |
| 477 | |
| 478 | if (!b) |
| 479 | return NULL; |
| 480 | |
| 481 | b->bi_destructor = bio_fs_destructor; |
| 482 | __bio_clone(b, bio); |
| 483 | |
| 484 | if (bio_integrity(bio)) { |
| 485 | int ret; |
| 486 | |
| 487 | ret = bio_integrity_clone(b, bio, gfp_mask, fs_bio_set); |
| 488 | |
| 489 | if (ret < 0) { |
| 490 | bio_put(b); |
| 491 | return NULL; |
| 492 | } |
| 493 | } |
| 494 | |
| 495 | return b; |
| 496 | } |
| 497 | EXPORT_SYMBOL(bio_clone); |
| 498 | |
| 499 | /** |
| 500 | * bio_get_nr_vecs - return approx number of vecs |
| 501 | * @bdev: I/O target |
| 502 | * |
| 503 | * Return the approximate number of pages we can send to this target. |
| 504 | * There's no guarantee that you will be able to fit this number of pages |
| 505 | * into a bio, it does not account for dynamic restrictions that vary |
| 506 | * on offset. |
| 507 | */ |
| 508 | int bio_get_nr_vecs(struct block_device *bdev) |
| 509 | { |
| 510 | struct request_queue *q = bdev_get_queue(bdev); |
| 511 | int nr_pages; |
| 512 | |
| 513 | nr_pages = min_t(unsigned, |
| 514 | queue_max_segments(q), |
| 515 | queue_max_sectors(q) / (PAGE_SIZE >> 9) + 1); |
| 516 | |
| 517 | return min_t(unsigned, nr_pages, BIO_MAX_PAGES); |
| 518 | |
| 519 | } |
| 520 | EXPORT_SYMBOL(bio_get_nr_vecs); |
| 521 | |
| 522 | static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page |
| 523 | *page, unsigned int len, unsigned int offset, |
| 524 | unsigned short max_sectors) |
| 525 | { |
| 526 | int retried_segments = 0; |
| 527 | struct bio_vec *bvec; |
| 528 | |
| 529 | /* |
| 530 | * cloned bio must not modify vec list |
| 531 | */ |
| 532 | if (unlikely(bio_flagged(bio, BIO_CLONED))) |
| 533 | return 0; |
| 534 | |
| 535 | if (((bio->bi_size + len) >> 9) > max_sectors) |
| 536 | return 0; |
| 537 | |
| 538 | /* |
| 539 | * For filesystems with a blocksize smaller than the pagesize |
| 540 | * we will often be called with the same page as last time and |
| 541 | * a consecutive offset. Optimize this special case. |
| 542 | */ |
| 543 | if (bio->bi_vcnt > 0) { |
| 544 | struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1]; |
| 545 | |
| 546 | if (page == prev->bv_page && |
| 547 | offset == prev->bv_offset + prev->bv_len) { |
| 548 | unsigned int prev_bv_len = prev->bv_len; |
| 549 | prev->bv_len += len; |
| 550 | |
| 551 | if (q->merge_bvec_fn) { |
| 552 | struct bvec_merge_data bvm = { |
| 553 | /* prev_bvec is already charged in |
| 554 | bi_size, discharge it in order to |
| 555 | simulate merging updated prev_bvec |
| 556 | as new bvec. */ |
| 557 | .bi_bdev = bio->bi_bdev, |
| 558 | .bi_sector = bio->bi_sector, |
| 559 | .bi_size = bio->bi_size - prev_bv_len, |
| 560 | .bi_rw = bio->bi_rw, |
| 561 | }; |
| 562 | |
| 563 | if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len) { |
| 564 | prev->bv_len -= len; |
| 565 | return 0; |
| 566 | } |
| 567 | } |
| 568 | |
| 569 | goto done; |
| 570 | } |
| 571 | } |
| 572 | |
| 573 | if (bio->bi_vcnt >= bio->bi_max_vecs) |
| 574 | return 0; |
| 575 | |
| 576 | /* |
| 577 | * we might lose a segment or two here, but rather that than |
| 578 | * make this too complex. |
| 579 | */ |
| 580 | |
| 581 | while (bio->bi_phys_segments >= queue_max_segments(q)) { |
| 582 | |
| 583 | if (retried_segments) |
| 584 | return 0; |
| 585 | |
| 586 | retried_segments = 1; |
| 587 | blk_recount_segments(q, bio); |
| 588 | } |
| 589 | |
| 590 | /* |
| 591 | * setup the new entry, we might clear it again later if we |
| 592 | * cannot add the page |
| 593 | */ |
| 594 | bvec = &bio->bi_io_vec[bio->bi_vcnt]; |
| 595 | bvec->bv_page = page; |
| 596 | bvec->bv_len = len; |
| 597 | bvec->bv_offset = offset; |
| 598 | |
| 599 | /* |
| 600 | * if queue has other restrictions (eg varying max sector size |
| 601 | * depending on offset), it can specify a merge_bvec_fn in the |
| 602 | * queue to get further control |
| 603 | */ |
| 604 | if (q->merge_bvec_fn) { |
| 605 | struct bvec_merge_data bvm = { |
| 606 | .bi_bdev = bio->bi_bdev, |
| 607 | .bi_sector = bio->bi_sector, |
| 608 | .bi_size = bio->bi_size, |
| 609 | .bi_rw = bio->bi_rw, |
| 610 | }; |
| 611 | |
| 612 | /* |
| 613 | * merge_bvec_fn() returns number of bytes it can accept |
| 614 | * at this offset |
| 615 | */ |
| 616 | if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len) { |
| 617 | bvec->bv_page = NULL; |
| 618 | bvec->bv_len = 0; |
| 619 | bvec->bv_offset = 0; |
| 620 | return 0; |
| 621 | } |
| 622 | } |
| 623 | |
| 624 | /* If we may be able to merge these biovecs, force a recount */ |
| 625 | if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec))) |
| 626 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); |
| 627 | |
| 628 | bio->bi_vcnt++; |
| 629 | bio->bi_phys_segments++; |
| 630 | done: |
| 631 | bio->bi_size += len; |
| 632 | return len; |
| 633 | } |
| 634 | |
| 635 | /** |
| 636 | * bio_add_pc_page - attempt to add page to bio |
| 637 | * @q: the target queue |
| 638 | * @bio: destination bio |
| 639 | * @page: page to add |
| 640 | * @len: vec entry length |
| 641 | * @offset: vec entry offset |
| 642 | * |
| 643 | * Attempt to add a page to the bio_vec maplist. This can fail for a |
| 644 | * number of reasons, such as the bio being full or target block device |
| 645 | * limitations. The target block device must allow bio's up to PAGE_SIZE, |
| 646 | * so it is always possible to add a single page to an empty bio. |
| 647 | * |
| 648 | * This should only be used by REQ_PC bios. |
| 649 | */ |
| 650 | int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page, |
| 651 | unsigned int len, unsigned int offset) |
| 652 | { |
| 653 | return __bio_add_page(q, bio, page, len, offset, |
| 654 | queue_max_hw_sectors(q)); |
| 655 | } |
| 656 | EXPORT_SYMBOL(bio_add_pc_page); |
| 657 | |
| 658 | /** |
| 659 | * bio_add_page - attempt to add page to bio |
| 660 | * @bio: destination bio |
| 661 | * @page: page to add |
| 662 | * @len: vec entry length |
| 663 | * @offset: vec entry offset |
| 664 | * |
| 665 | * Attempt to add a page to the bio_vec maplist. This can fail for a |
| 666 | * number of reasons, such as the bio being full or target block device |
| 667 | * limitations. The target block device must allow bio's up to PAGE_SIZE, |
| 668 | * so it is always possible to add a single page to an empty bio. |
| 669 | */ |
| 670 | int bio_add_page(struct bio *bio, struct page *page, unsigned int len, |
| 671 | unsigned int offset) |
| 672 | { |
| 673 | struct request_queue *q = bdev_get_queue(bio->bi_bdev); |
| 674 | return __bio_add_page(q, bio, page, len, offset, queue_max_sectors(q)); |
| 675 | } |
| 676 | EXPORT_SYMBOL(bio_add_page); |
| 677 | |
| 678 | struct bio_map_data { |
| 679 | struct bio_vec *iovecs; |
| 680 | struct sg_iovec *sgvecs; |
| 681 | int nr_sgvecs; |
| 682 | int is_our_pages; |
| 683 | }; |
| 684 | |
| 685 | static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio, |
| 686 | struct sg_iovec *iov, int iov_count, |
| 687 | int is_our_pages) |
| 688 | { |
| 689 | memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt); |
| 690 | memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count); |
| 691 | bmd->nr_sgvecs = iov_count; |
| 692 | bmd->is_our_pages = is_our_pages; |
| 693 | bio->bi_private = bmd; |
| 694 | } |
| 695 | |
| 696 | static void bio_free_map_data(struct bio_map_data *bmd) |
| 697 | { |
| 698 | kfree(bmd->iovecs); |
| 699 | kfree(bmd->sgvecs); |
| 700 | kfree(bmd); |
| 701 | } |
| 702 | |
| 703 | static struct bio_map_data *bio_alloc_map_data(int nr_segs, |
| 704 | unsigned int iov_count, |
| 705 | gfp_t gfp_mask) |
| 706 | { |
| 707 | struct bio_map_data *bmd; |
| 708 | |
| 709 | if (iov_count > UIO_MAXIOV) |
| 710 | return NULL; |
| 711 | |
| 712 | bmd = kmalloc(sizeof(*bmd), gfp_mask); |
| 713 | if (!bmd) |
| 714 | return NULL; |
| 715 | |
| 716 | bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, gfp_mask); |
| 717 | if (!bmd->iovecs) { |
| 718 | kfree(bmd); |
| 719 | return NULL; |
| 720 | } |
| 721 | |
| 722 | bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, gfp_mask); |
| 723 | if (bmd->sgvecs) |
| 724 | return bmd; |
| 725 | |
| 726 | kfree(bmd->iovecs); |
| 727 | kfree(bmd); |
| 728 | return NULL; |
| 729 | } |
| 730 | |
| 731 | static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs, |
| 732 | struct sg_iovec *iov, int iov_count, |
| 733 | int to_user, int from_user, int do_free_page) |
| 734 | { |
| 735 | int ret = 0, i; |
| 736 | struct bio_vec *bvec; |
| 737 | int iov_idx = 0; |
| 738 | unsigned int iov_off = 0; |
| 739 | |
| 740 | __bio_for_each_segment(bvec, bio, i, 0) { |
| 741 | char *bv_addr = page_address(bvec->bv_page); |
| 742 | unsigned int bv_len = iovecs[i].bv_len; |
| 743 | |
| 744 | while (bv_len && iov_idx < iov_count) { |
| 745 | unsigned int bytes; |
| 746 | char __user *iov_addr; |
| 747 | |
| 748 | bytes = min_t(unsigned int, |
| 749 | iov[iov_idx].iov_len - iov_off, bv_len); |
| 750 | iov_addr = iov[iov_idx].iov_base + iov_off; |
| 751 | |
| 752 | if (!ret) { |
| 753 | if (to_user) |
| 754 | ret = copy_to_user(iov_addr, bv_addr, |
| 755 | bytes); |
| 756 | |
| 757 | if (from_user) |
| 758 | ret = copy_from_user(bv_addr, iov_addr, |
| 759 | bytes); |
| 760 | |
| 761 | if (ret) |
| 762 | ret = -EFAULT; |
| 763 | } |
| 764 | |
| 765 | bv_len -= bytes; |
| 766 | bv_addr += bytes; |
| 767 | iov_addr += bytes; |
| 768 | iov_off += bytes; |
| 769 | |
| 770 | if (iov[iov_idx].iov_len == iov_off) { |
| 771 | iov_idx++; |
| 772 | iov_off = 0; |
| 773 | } |
| 774 | } |
| 775 | |
| 776 | if (do_free_page) |
| 777 | __free_page(bvec->bv_page); |
| 778 | } |
| 779 | |
| 780 | return ret; |
| 781 | } |
| 782 | |
| 783 | /** |
| 784 | * bio_uncopy_user - finish previously mapped bio |
| 785 | * @bio: bio being terminated |
| 786 | * |
| 787 | * Free pages allocated from bio_copy_user() and write back data |
| 788 | * to user space in case of a read. |
| 789 | */ |
| 790 | int bio_uncopy_user(struct bio *bio) |
| 791 | { |
| 792 | struct bio_map_data *bmd = bio->bi_private; |
| 793 | int ret = 0; |
| 794 | |
| 795 | if (!bio_flagged(bio, BIO_NULL_MAPPED)) |
| 796 | ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs, |
| 797 | bmd->nr_sgvecs, bio_data_dir(bio) == READ, |
| 798 | 0, bmd->is_our_pages); |
| 799 | bio_free_map_data(bmd); |
| 800 | bio_put(bio); |
| 801 | return ret; |
| 802 | } |
| 803 | EXPORT_SYMBOL(bio_uncopy_user); |
| 804 | |
| 805 | /** |
| 806 | * bio_copy_user_iov - copy user data to bio |
| 807 | * @q: destination block queue |
| 808 | * @map_data: pointer to the rq_map_data holding pages (if necessary) |
| 809 | * @iov: the iovec. |
| 810 | * @iov_count: number of elements in the iovec |
| 811 | * @write_to_vm: bool indicating writing to pages or not |
| 812 | * @gfp_mask: memory allocation flags |
| 813 | * |
| 814 | * Prepares and returns a bio for indirect user io, bouncing data |
| 815 | * to/from kernel pages as necessary. Must be paired with |
| 816 | * call bio_uncopy_user() on io completion. |
| 817 | */ |
| 818 | struct bio *bio_copy_user_iov(struct request_queue *q, |
| 819 | struct rq_map_data *map_data, |
| 820 | struct sg_iovec *iov, int iov_count, |
| 821 | int write_to_vm, gfp_t gfp_mask) |
| 822 | { |
| 823 | struct bio_map_data *bmd; |
| 824 | struct bio_vec *bvec; |
| 825 | struct page *page; |
| 826 | struct bio *bio; |
| 827 | int i, ret; |
| 828 | int nr_pages = 0; |
| 829 | unsigned int len = 0; |
| 830 | unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0; |
| 831 | |
| 832 | for (i = 0; i < iov_count; i++) { |
| 833 | unsigned long uaddr; |
| 834 | unsigned long end; |
| 835 | unsigned long start; |
| 836 | |
| 837 | uaddr = (unsigned long)iov[i].iov_base; |
| 838 | end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 839 | start = uaddr >> PAGE_SHIFT; |
| 840 | |
| 841 | /* |
| 842 | * Overflow, abort |
| 843 | */ |
| 844 | if (end < start) |
| 845 | return ERR_PTR(-EINVAL); |
| 846 | |
| 847 | nr_pages += end - start; |
| 848 | len += iov[i].iov_len; |
| 849 | } |
| 850 | |
| 851 | if (offset) |
| 852 | nr_pages++; |
| 853 | |
| 854 | bmd = bio_alloc_map_data(nr_pages, iov_count, gfp_mask); |
| 855 | if (!bmd) |
| 856 | return ERR_PTR(-ENOMEM); |
| 857 | |
| 858 | ret = -ENOMEM; |
| 859 | bio = bio_kmalloc(gfp_mask, nr_pages); |
| 860 | if (!bio) |
| 861 | goto out_bmd; |
| 862 | |
| 863 | if (!write_to_vm) |
| 864 | bio->bi_rw |= REQ_WRITE; |
| 865 | |
| 866 | ret = 0; |
| 867 | |
| 868 | if (map_data) { |
| 869 | nr_pages = 1 << map_data->page_order; |
| 870 | i = map_data->offset / PAGE_SIZE; |
| 871 | } |
| 872 | while (len) { |
| 873 | unsigned int bytes = PAGE_SIZE; |
| 874 | |
| 875 | bytes -= offset; |
| 876 | |
| 877 | if (bytes > len) |
| 878 | bytes = len; |
| 879 | |
| 880 | if (map_data) { |
| 881 | if (i == map_data->nr_entries * nr_pages) { |
| 882 | ret = -ENOMEM; |
| 883 | break; |
| 884 | } |
| 885 | |
| 886 | page = map_data->pages[i / nr_pages]; |
| 887 | page += (i % nr_pages); |
| 888 | |
| 889 | i++; |
| 890 | } else { |
| 891 | page = alloc_page(q->bounce_gfp | gfp_mask); |
| 892 | if (!page) { |
| 893 | ret = -ENOMEM; |
| 894 | break; |
| 895 | } |
| 896 | } |
| 897 | |
| 898 | if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) |
| 899 | break; |
| 900 | |
| 901 | len -= bytes; |
| 902 | offset = 0; |
| 903 | } |
| 904 | |
| 905 | if (ret) |
| 906 | goto cleanup; |
| 907 | |
| 908 | /* |
| 909 | * success |
| 910 | */ |
| 911 | if ((!write_to_vm && (!map_data || !map_data->null_mapped)) || |
| 912 | (map_data && map_data->from_user)) { |
| 913 | ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 1, 0); |
| 914 | if (ret) |
| 915 | goto cleanup; |
| 916 | } |
| 917 | |
| 918 | bio_set_map_data(bmd, bio, iov, iov_count, map_data ? 0 : 1); |
| 919 | return bio; |
| 920 | cleanup: |
| 921 | if (!map_data) |
| 922 | bio_for_each_segment(bvec, bio, i) |
| 923 | __free_page(bvec->bv_page); |
| 924 | |
| 925 | bio_put(bio); |
| 926 | out_bmd: |
| 927 | bio_free_map_data(bmd); |
| 928 | return ERR_PTR(ret); |
| 929 | } |
| 930 | |
| 931 | /** |
| 932 | * bio_copy_user - copy user data to bio |
| 933 | * @q: destination block queue |
| 934 | * @map_data: pointer to the rq_map_data holding pages (if necessary) |
| 935 | * @uaddr: start of user address |
| 936 | * @len: length in bytes |
| 937 | * @write_to_vm: bool indicating writing to pages or not |
| 938 | * @gfp_mask: memory allocation flags |
| 939 | * |
| 940 | * Prepares and returns a bio for indirect user io, bouncing data |
| 941 | * to/from kernel pages as necessary. Must be paired with |
| 942 | * call bio_uncopy_user() on io completion. |
| 943 | */ |
| 944 | struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data, |
| 945 | unsigned long uaddr, unsigned int len, |
| 946 | int write_to_vm, gfp_t gfp_mask) |
| 947 | { |
| 948 | struct sg_iovec iov; |
| 949 | |
| 950 | iov.iov_base = (void __user *)uaddr; |
| 951 | iov.iov_len = len; |
| 952 | |
| 953 | return bio_copy_user_iov(q, map_data, &iov, 1, write_to_vm, gfp_mask); |
| 954 | } |
| 955 | EXPORT_SYMBOL(bio_copy_user); |
| 956 | |
| 957 | static struct bio *__bio_map_user_iov(struct request_queue *q, |
| 958 | struct block_device *bdev, |
| 959 | struct sg_iovec *iov, int iov_count, |
| 960 | int write_to_vm, gfp_t gfp_mask) |
| 961 | { |
| 962 | int i, j; |
| 963 | int nr_pages = 0; |
| 964 | struct page **pages; |
| 965 | struct bio *bio; |
| 966 | int cur_page = 0; |
| 967 | int ret, offset; |
| 968 | |
| 969 | for (i = 0; i < iov_count; i++) { |
| 970 | unsigned long uaddr = (unsigned long)iov[i].iov_base; |
| 971 | unsigned long len = iov[i].iov_len; |
| 972 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 973 | unsigned long start = uaddr >> PAGE_SHIFT; |
| 974 | |
| 975 | /* |
| 976 | * Overflow, abort |
| 977 | */ |
| 978 | if (end < start) |
| 979 | return ERR_PTR(-EINVAL); |
| 980 | |
| 981 | nr_pages += end - start; |
| 982 | /* |
| 983 | * buffer must be aligned to at least hardsector size for now |
| 984 | */ |
| 985 | if (uaddr & queue_dma_alignment(q)) |
| 986 | return ERR_PTR(-EINVAL); |
| 987 | } |
| 988 | |
| 989 | if (!nr_pages) |
| 990 | return ERR_PTR(-EINVAL); |
| 991 | |
| 992 | bio = bio_kmalloc(gfp_mask, nr_pages); |
| 993 | if (!bio) |
| 994 | return ERR_PTR(-ENOMEM); |
| 995 | |
| 996 | ret = -ENOMEM; |
| 997 | pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask); |
| 998 | if (!pages) |
| 999 | goto out; |
| 1000 | |
| 1001 | for (i = 0; i < iov_count; i++) { |
| 1002 | unsigned long uaddr = (unsigned long)iov[i].iov_base; |
| 1003 | unsigned long len = iov[i].iov_len; |
| 1004 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 1005 | unsigned long start = uaddr >> PAGE_SHIFT; |
| 1006 | const int local_nr_pages = end - start; |
| 1007 | const int page_limit = cur_page + local_nr_pages; |
| 1008 | |
| 1009 | ret = get_user_pages_fast(uaddr, local_nr_pages, |
| 1010 | write_to_vm, &pages[cur_page]); |
| 1011 | if (ret < local_nr_pages) { |
| 1012 | ret = -EFAULT; |
| 1013 | goto out_unmap; |
| 1014 | } |
| 1015 | |
| 1016 | offset = uaddr & ~PAGE_MASK; |
| 1017 | for (j = cur_page; j < page_limit; j++) { |
| 1018 | unsigned int bytes = PAGE_SIZE - offset; |
| 1019 | |
| 1020 | if (len <= 0) |
| 1021 | break; |
| 1022 | |
| 1023 | if (bytes > len) |
| 1024 | bytes = len; |
| 1025 | |
| 1026 | /* |
| 1027 | * sorry... |
| 1028 | */ |
| 1029 | if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < |
| 1030 | bytes) |
| 1031 | break; |
| 1032 | |
| 1033 | len -= bytes; |
| 1034 | offset = 0; |
| 1035 | } |
| 1036 | |
| 1037 | cur_page = j; |
| 1038 | /* |
| 1039 | * release the pages we didn't map into the bio, if any |
| 1040 | */ |
| 1041 | while (j < page_limit) |
| 1042 | page_cache_release(pages[j++]); |
| 1043 | } |
| 1044 | |
| 1045 | kfree(pages); |
| 1046 | |
| 1047 | /* |
| 1048 | * set data direction, and check if mapped pages need bouncing |
| 1049 | */ |
| 1050 | if (!write_to_vm) |
| 1051 | bio->bi_rw |= REQ_WRITE; |
| 1052 | |
| 1053 | bio->bi_bdev = bdev; |
| 1054 | bio->bi_flags |= (1 << BIO_USER_MAPPED); |
| 1055 | return bio; |
| 1056 | |
| 1057 | out_unmap: |
| 1058 | for (i = 0; i < nr_pages; i++) { |
| 1059 | if(!pages[i]) |
| 1060 | break; |
| 1061 | page_cache_release(pages[i]); |
| 1062 | } |
| 1063 | out: |
| 1064 | kfree(pages); |
| 1065 | bio_put(bio); |
| 1066 | return ERR_PTR(ret); |
| 1067 | } |
| 1068 | |
| 1069 | /** |
| 1070 | * bio_map_user - map user address into bio |
| 1071 | * @q: the struct request_queue for the bio |
| 1072 | * @bdev: destination block device |
| 1073 | * @uaddr: start of user address |
| 1074 | * @len: length in bytes |
| 1075 | * @write_to_vm: bool indicating writing to pages or not |
| 1076 | * @gfp_mask: memory allocation flags |
| 1077 | * |
| 1078 | * Map the user space address into a bio suitable for io to a block |
| 1079 | * device. Returns an error pointer in case of error. |
| 1080 | */ |
| 1081 | struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev, |
| 1082 | unsigned long uaddr, unsigned int len, int write_to_vm, |
| 1083 | gfp_t gfp_mask) |
| 1084 | { |
| 1085 | struct sg_iovec iov; |
| 1086 | |
| 1087 | iov.iov_base = (void __user *)uaddr; |
| 1088 | iov.iov_len = len; |
| 1089 | |
| 1090 | return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask); |
| 1091 | } |
| 1092 | EXPORT_SYMBOL(bio_map_user); |
| 1093 | |
| 1094 | /** |
| 1095 | * bio_map_user_iov - map user sg_iovec table into bio |
| 1096 | * @q: the struct request_queue for the bio |
| 1097 | * @bdev: destination block device |
| 1098 | * @iov: the iovec. |
| 1099 | * @iov_count: number of elements in the iovec |
| 1100 | * @write_to_vm: bool indicating writing to pages or not |
| 1101 | * @gfp_mask: memory allocation flags |
| 1102 | * |
| 1103 | * Map the user space address into a bio suitable for io to a block |
| 1104 | * device. Returns an error pointer in case of error. |
| 1105 | */ |
| 1106 | struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev, |
| 1107 | struct sg_iovec *iov, int iov_count, |
| 1108 | int write_to_vm, gfp_t gfp_mask) |
| 1109 | { |
| 1110 | struct bio *bio; |
| 1111 | |
| 1112 | bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm, |
| 1113 | gfp_mask); |
| 1114 | if (IS_ERR(bio)) |
| 1115 | return bio; |
| 1116 | |
| 1117 | /* |
| 1118 | * subtle -- if __bio_map_user() ended up bouncing a bio, |
| 1119 | * it would normally disappear when its bi_end_io is run. |
| 1120 | * however, we need it for the unmap, so grab an extra |
| 1121 | * reference to it |
| 1122 | */ |
| 1123 | bio_get(bio); |
| 1124 | |
| 1125 | return bio; |
| 1126 | } |
| 1127 | |
| 1128 | static void __bio_unmap_user(struct bio *bio) |
| 1129 | { |
| 1130 | struct bio_vec *bvec; |
| 1131 | int i; |
| 1132 | |
| 1133 | /* |
| 1134 | * make sure we dirty pages we wrote to |
| 1135 | */ |
| 1136 | __bio_for_each_segment(bvec, bio, i, 0) { |
| 1137 | if (bio_data_dir(bio) == READ) |
| 1138 | set_page_dirty_lock(bvec->bv_page); |
| 1139 | |
| 1140 | page_cache_release(bvec->bv_page); |
| 1141 | } |
| 1142 | |
| 1143 | bio_put(bio); |
| 1144 | } |
| 1145 | |
| 1146 | /** |
| 1147 | * bio_unmap_user - unmap a bio |
| 1148 | * @bio: the bio being unmapped |
| 1149 | * |
| 1150 | * Unmap a bio previously mapped by bio_map_user(). Must be called with |
| 1151 | * a process context. |
| 1152 | * |
| 1153 | * bio_unmap_user() may sleep. |
| 1154 | */ |
| 1155 | void bio_unmap_user(struct bio *bio) |
| 1156 | { |
| 1157 | __bio_unmap_user(bio); |
| 1158 | bio_put(bio); |
| 1159 | } |
| 1160 | EXPORT_SYMBOL(bio_unmap_user); |
| 1161 | |
| 1162 | static void bio_map_kern_endio(struct bio *bio, int err) |
| 1163 | { |
| 1164 | bio_put(bio); |
| 1165 | } |
| 1166 | |
| 1167 | static struct bio *__bio_map_kern(struct request_queue *q, void *data, |
| 1168 | unsigned int len, gfp_t gfp_mask) |
| 1169 | { |
| 1170 | unsigned long kaddr = (unsigned long)data; |
| 1171 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 1172 | unsigned long start = kaddr >> PAGE_SHIFT; |
| 1173 | const int nr_pages = end - start; |
| 1174 | int offset, i; |
| 1175 | struct bio *bio; |
| 1176 | |
| 1177 | bio = bio_kmalloc(gfp_mask, nr_pages); |
| 1178 | if (!bio) |
| 1179 | return ERR_PTR(-ENOMEM); |
| 1180 | |
| 1181 | offset = offset_in_page(kaddr); |
| 1182 | for (i = 0; i < nr_pages; i++) { |
| 1183 | unsigned int bytes = PAGE_SIZE - offset; |
| 1184 | |
| 1185 | if (len <= 0) |
| 1186 | break; |
| 1187 | |
| 1188 | if (bytes > len) |
| 1189 | bytes = len; |
| 1190 | |
| 1191 | if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, |
| 1192 | offset) < bytes) |
| 1193 | break; |
| 1194 | |
| 1195 | data += bytes; |
| 1196 | len -= bytes; |
| 1197 | offset = 0; |
| 1198 | } |
| 1199 | |
| 1200 | bio->bi_end_io = bio_map_kern_endio; |
| 1201 | return bio; |
| 1202 | } |
| 1203 | |
| 1204 | /** |
| 1205 | * bio_map_kern - map kernel address into bio |
| 1206 | * @q: the struct request_queue for the bio |
| 1207 | * @data: pointer to buffer to map |
| 1208 | * @len: length in bytes |
| 1209 | * @gfp_mask: allocation flags for bio allocation |
| 1210 | * |
| 1211 | * Map the kernel address into a bio suitable for io to a block |
| 1212 | * device. Returns an error pointer in case of error. |
| 1213 | */ |
| 1214 | struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len, |
| 1215 | gfp_t gfp_mask) |
| 1216 | { |
| 1217 | struct bio *bio; |
| 1218 | |
| 1219 | bio = __bio_map_kern(q, data, len, gfp_mask); |
| 1220 | if (IS_ERR(bio)) |
| 1221 | return bio; |
| 1222 | |
| 1223 | if (bio->bi_size == len) |
| 1224 | return bio; |
| 1225 | |
| 1226 | /* |
| 1227 | * Don't support partial mappings. |
| 1228 | */ |
| 1229 | bio_put(bio); |
| 1230 | return ERR_PTR(-EINVAL); |
| 1231 | } |
| 1232 | EXPORT_SYMBOL(bio_map_kern); |
| 1233 | |
| 1234 | static void bio_copy_kern_endio(struct bio *bio, int err) |
| 1235 | { |
| 1236 | struct bio_vec *bvec; |
| 1237 | const int read = bio_data_dir(bio) == READ; |
| 1238 | struct bio_map_data *bmd = bio->bi_private; |
| 1239 | int i; |
| 1240 | char *p = bmd->sgvecs[0].iov_base; |
| 1241 | |
| 1242 | __bio_for_each_segment(bvec, bio, i, 0) { |
| 1243 | char *addr = page_address(bvec->bv_page); |
| 1244 | int len = bmd->iovecs[i].bv_len; |
| 1245 | |
| 1246 | if (read) |
| 1247 | memcpy(p, addr, len); |
| 1248 | |
| 1249 | __free_page(bvec->bv_page); |
| 1250 | p += len; |
| 1251 | } |
| 1252 | |
| 1253 | bio_free_map_data(bmd); |
| 1254 | bio_put(bio); |
| 1255 | } |
| 1256 | |
| 1257 | /** |
| 1258 | * bio_copy_kern - copy kernel address into bio |
| 1259 | * @q: the struct request_queue for the bio |
| 1260 | * @data: pointer to buffer to copy |
| 1261 | * @len: length in bytes |
| 1262 | * @gfp_mask: allocation flags for bio and page allocation |
| 1263 | * @reading: data direction is READ |
| 1264 | * |
| 1265 | * copy the kernel address into a bio suitable for io to a block |
| 1266 | * device. Returns an error pointer in case of error. |
| 1267 | */ |
| 1268 | struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, |
| 1269 | gfp_t gfp_mask, int reading) |
| 1270 | { |
| 1271 | struct bio *bio; |
| 1272 | struct bio_vec *bvec; |
| 1273 | int i; |
| 1274 | |
| 1275 | bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask); |
| 1276 | if (IS_ERR(bio)) |
| 1277 | return bio; |
| 1278 | |
| 1279 | if (!reading) { |
| 1280 | void *p = data; |
| 1281 | |
| 1282 | bio_for_each_segment(bvec, bio, i) { |
| 1283 | char *addr = page_address(bvec->bv_page); |
| 1284 | |
| 1285 | memcpy(addr, p, bvec->bv_len); |
| 1286 | p += bvec->bv_len; |
| 1287 | } |
| 1288 | } |
| 1289 | |
| 1290 | bio->bi_end_io = bio_copy_kern_endio; |
| 1291 | |
| 1292 | return bio; |
| 1293 | } |
| 1294 | EXPORT_SYMBOL(bio_copy_kern); |
| 1295 | |
| 1296 | /* |
| 1297 | * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions |
| 1298 | * for performing direct-IO in BIOs. |
| 1299 | * |
| 1300 | * The problem is that we cannot run set_page_dirty() from interrupt context |
| 1301 | * because the required locks are not interrupt-safe. So what we can do is to |
| 1302 | * mark the pages dirty _before_ performing IO. And in interrupt context, |
| 1303 | * check that the pages are still dirty. If so, fine. If not, redirty them |
| 1304 | * in process context. |
| 1305 | * |
| 1306 | * We special-case compound pages here: normally this means reads into hugetlb |
| 1307 | * pages. The logic in here doesn't really work right for compound pages |
| 1308 | * because the VM does not uniformly chase down the head page in all cases. |
| 1309 | * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't |
| 1310 | * handle them at all. So we skip compound pages here at an early stage. |
| 1311 | * |
| 1312 | * Note that this code is very hard to test under normal circumstances because |
| 1313 | * direct-io pins the pages with get_user_pages(). This makes |
| 1314 | * is_page_cache_freeable return false, and the VM will not clean the pages. |
| 1315 | * But other code (eg, pdflush) could clean the pages if they are mapped |
| 1316 | * pagecache. |
| 1317 | * |
| 1318 | * Simply disabling the call to bio_set_pages_dirty() is a good way to test the |
| 1319 | * deferred bio dirtying paths. |
| 1320 | */ |
| 1321 | |
| 1322 | /* |
| 1323 | * bio_set_pages_dirty() will mark all the bio's pages as dirty. |
| 1324 | */ |
| 1325 | void bio_set_pages_dirty(struct bio *bio) |
| 1326 | { |
| 1327 | struct bio_vec *bvec = bio->bi_io_vec; |
| 1328 | int i; |
| 1329 | |
| 1330 | for (i = 0; i < bio->bi_vcnt; i++) { |
| 1331 | struct page *page = bvec[i].bv_page; |
| 1332 | |
| 1333 | if (page && !PageCompound(page)) |
| 1334 | set_page_dirty_lock(page); |
| 1335 | } |
| 1336 | } |
| 1337 | |
| 1338 | static void bio_release_pages(struct bio *bio) |
| 1339 | { |
| 1340 | struct bio_vec *bvec = bio->bi_io_vec; |
| 1341 | int i; |
| 1342 | |
| 1343 | for (i = 0; i < bio->bi_vcnt; i++) { |
| 1344 | struct page *page = bvec[i].bv_page; |
| 1345 | |
| 1346 | if (page) |
| 1347 | put_page(page); |
| 1348 | } |
| 1349 | } |
| 1350 | |
| 1351 | /* |
| 1352 | * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. |
| 1353 | * If they are, then fine. If, however, some pages are clean then they must |
| 1354 | * have been written out during the direct-IO read. So we take another ref on |
| 1355 | * the BIO and the offending pages and re-dirty the pages in process context. |
| 1356 | * |
| 1357 | * It is expected that bio_check_pages_dirty() will wholly own the BIO from |
| 1358 | * here on. It will run one page_cache_release() against each page and will |
| 1359 | * run one bio_put() against the BIO. |
| 1360 | */ |
| 1361 | |
| 1362 | static void bio_dirty_fn(struct work_struct *work); |
| 1363 | |
| 1364 | static DECLARE_WORK(bio_dirty_work, bio_dirty_fn); |
| 1365 | static DEFINE_SPINLOCK(bio_dirty_lock); |
| 1366 | static struct bio *bio_dirty_list; |
| 1367 | |
| 1368 | /* |
| 1369 | * This runs in process context |
| 1370 | */ |
| 1371 | static void bio_dirty_fn(struct work_struct *work) |
| 1372 | { |
| 1373 | unsigned long flags; |
| 1374 | struct bio *bio; |
| 1375 | |
| 1376 | spin_lock_irqsave(&bio_dirty_lock, flags); |
| 1377 | bio = bio_dirty_list; |
| 1378 | bio_dirty_list = NULL; |
| 1379 | spin_unlock_irqrestore(&bio_dirty_lock, flags); |
| 1380 | |
| 1381 | while (bio) { |
| 1382 | struct bio *next = bio->bi_private; |
| 1383 | |
| 1384 | bio_set_pages_dirty(bio); |
| 1385 | bio_release_pages(bio); |
| 1386 | bio_put(bio); |
| 1387 | bio = next; |
| 1388 | } |
| 1389 | } |
| 1390 | |
| 1391 | void bio_check_pages_dirty(struct bio *bio) |
| 1392 | { |
| 1393 | struct bio_vec *bvec = bio->bi_io_vec; |
| 1394 | int nr_clean_pages = 0; |
| 1395 | int i; |
| 1396 | |
| 1397 | for (i = 0; i < bio->bi_vcnt; i++) { |
| 1398 | struct page *page = bvec[i].bv_page; |
| 1399 | |
| 1400 | if (PageDirty(page) || PageCompound(page)) { |
| 1401 | page_cache_release(page); |
| 1402 | bvec[i].bv_page = NULL; |
| 1403 | } else { |
| 1404 | nr_clean_pages++; |
| 1405 | } |
| 1406 | } |
| 1407 | |
| 1408 | if (nr_clean_pages) { |
| 1409 | unsigned long flags; |
| 1410 | |
| 1411 | spin_lock_irqsave(&bio_dirty_lock, flags); |
| 1412 | bio->bi_private = bio_dirty_list; |
| 1413 | bio_dirty_list = bio; |
| 1414 | spin_unlock_irqrestore(&bio_dirty_lock, flags); |
| 1415 | schedule_work(&bio_dirty_work); |
| 1416 | } else { |
| 1417 | bio_put(bio); |
| 1418 | } |
| 1419 | } |
| 1420 | |
| 1421 | #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE |
| 1422 | void bio_flush_dcache_pages(struct bio *bi) |
| 1423 | { |
| 1424 | int i; |
| 1425 | struct bio_vec *bvec; |
| 1426 | |
| 1427 | bio_for_each_segment(bvec, bi, i) |
| 1428 | flush_dcache_page(bvec->bv_page); |
| 1429 | } |
| 1430 | EXPORT_SYMBOL(bio_flush_dcache_pages); |
| 1431 | #endif |
| 1432 | |
| 1433 | /** |
| 1434 | * bio_endio - end I/O on a bio |
| 1435 | * @bio: bio |
| 1436 | * @error: error, if any |
| 1437 | * |
| 1438 | * Description: |
| 1439 | * bio_endio() will end I/O on the whole bio. bio_endio() is the |
| 1440 | * preferred way to end I/O on a bio, it takes care of clearing |
| 1441 | * BIO_UPTODATE on error. @error is 0 on success, and and one of the |
| 1442 | * established -Exxxx (-EIO, for instance) error values in case |
| 1443 | * something went wrong. No one should call bi_end_io() directly on a |
| 1444 | * bio unless they own it and thus know that it has an end_io |
| 1445 | * function. |
| 1446 | **/ |
| 1447 | void bio_endio(struct bio *bio, int error) |
| 1448 | { |
| 1449 | if (error) |
| 1450 | clear_bit(BIO_UPTODATE, &bio->bi_flags); |
| 1451 | else if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) |
| 1452 | error = -EIO; |
| 1453 | |
| 1454 | if (bio->bi_end_io) |
| 1455 | bio->bi_end_io(bio, error); |
| 1456 | } |
| 1457 | EXPORT_SYMBOL(bio_endio); |
| 1458 | |
| 1459 | void bio_pair_release(struct bio_pair *bp) |
| 1460 | { |
| 1461 | if (atomic_dec_and_test(&bp->cnt)) { |
| 1462 | struct bio *master = bp->bio1.bi_private; |
| 1463 | |
| 1464 | bio_endio(master, bp->error); |
| 1465 | mempool_free(bp, bp->bio2.bi_private); |
| 1466 | } |
| 1467 | } |
| 1468 | EXPORT_SYMBOL(bio_pair_release); |
| 1469 | |
| 1470 | static void bio_pair_end_1(struct bio *bi, int err) |
| 1471 | { |
| 1472 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio1); |
| 1473 | |
| 1474 | if (err) |
| 1475 | bp->error = err; |
| 1476 | |
| 1477 | bio_pair_release(bp); |
| 1478 | } |
| 1479 | |
| 1480 | static void bio_pair_end_2(struct bio *bi, int err) |
| 1481 | { |
| 1482 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio2); |
| 1483 | |
| 1484 | if (err) |
| 1485 | bp->error = err; |
| 1486 | |
| 1487 | bio_pair_release(bp); |
| 1488 | } |
| 1489 | |
| 1490 | /* |
| 1491 | * split a bio - only worry about a bio with a single page in its iovec |
| 1492 | */ |
| 1493 | struct bio_pair *bio_split(struct bio *bi, int first_sectors) |
| 1494 | { |
| 1495 | struct bio_pair *bp = mempool_alloc(bio_split_pool, GFP_NOIO); |
| 1496 | |
| 1497 | if (!bp) |
| 1498 | return bp; |
| 1499 | |
| 1500 | trace_block_split(bdev_get_queue(bi->bi_bdev), bi, |
| 1501 | bi->bi_sector + first_sectors); |
| 1502 | |
| 1503 | BUG_ON(bi->bi_vcnt != 1); |
| 1504 | BUG_ON(bi->bi_idx != 0); |
| 1505 | atomic_set(&bp->cnt, 3); |
| 1506 | bp->error = 0; |
| 1507 | bp->bio1 = *bi; |
| 1508 | bp->bio2 = *bi; |
| 1509 | bp->bio2.bi_sector += first_sectors; |
| 1510 | bp->bio2.bi_size -= first_sectors << 9; |
| 1511 | bp->bio1.bi_size = first_sectors << 9; |
| 1512 | |
| 1513 | bp->bv1 = bi->bi_io_vec[0]; |
| 1514 | bp->bv2 = bi->bi_io_vec[0]; |
| 1515 | bp->bv2.bv_offset += first_sectors << 9; |
| 1516 | bp->bv2.bv_len -= first_sectors << 9; |
| 1517 | bp->bv1.bv_len = first_sectors << 9; |
| 1518 | |
| 1519 | bp->bio1.bi_io_vec = &bp->bv1; |
| 1520 | bp->bio2.bi_io_vec = &bp->bv2; |
| 1521 | |
| 1522 | bp->bio1.bi_max_vecs = 1; |
| 1523 | bp->bio2.bi_max_vecs = 1; |
| 1524 | |
| 1525 | bp->bio1.bi_end_io = bio_pair_end_1; |
| 1526 | bp->bio2.bi_end_io = bio_pair_end_2; |
| 1527 | |
| 1528 | bp->bio1.bi_private = bi; |
| 1529 | bp->bio2.bi_private = bio_split_pool; |
| 1530 | |
| 1531 | if (bio_integrity(bi)) |
| 1532 | bio_integrity_split(bi, bp, first_sectors); |
| 1533 | |
| 1534 | return bp; |
| 1535 | } |
| 1536 | EXPORT_SYMBOL(bio_split); |
| 1537 | |
| 1538 | /** |
| 1539 | * bio_sector_offset - Find hardware sector offset in bio |
| 1540 | * @bio: bio to inspect |
| 1541 | * @index: bio_vec index |
| 1542 | * @offset: offset in bv_page |
| 1543 | * |
| 1544 | * Return the number of hardware sectors between beginning of bio |
| 1545 | * and an end point indicated by a bio_vec index and an offset |
| 1546 | * within that vector's page. |
| 1547 | */ |
| 1548 | sector_t bio_sector_offset(struct bio *bio, unsigned short index, |
| 1549 | unsigned int offset) |
| 1550 | { |
| 1551 | unsigned int sector_sz; |
| 1552 | struct bio_vec *bv; |
| 1553 | sector_t sectors; |
| 1554 | int i; |
| 1555 | |
| 1556 | sector_sz = queue_logical_block_size(bio->bi_bdev->bd_disk->queue); |
| 1557 | sectors = 0; |
| 1558 | |
| 1559 | if (index >= bio->bi_idx) |
| 1560 | index = bio->bi_vcnt - 1; |
| 1561 | |
| 1562 | __bio_for_each_segment(bv, bio, i, 0) { |
| 1563 | if (i == index) { |
| 1564 | if (offset > bv->bv_offset) |
| 1565 | sectors += (offset - bv->bv_offset) / sector_sz; |
| 1566 | break; |
| 1567 | } |
| 1568 | |
| 1569 | sectors += bv->bv_len / sector_sz; |
| 1570 | } |
| 1571 | |
| 1572 | return sectors; |
| 1573 | } |
| 1574 | EXPORT_SYMBOL(bio_sector_offset); |
| 1575 | |
| 1576 | /* |
| 1577 | * create memory pools for biovec's in a bio_set. |
| 1578 | * use the global biovec slabs created for general use. |
| 1579 | */ |
| 1580 | static int biovec_create_pools(struct bio_set *bs, int pool_entries) |
| 1581 | { |
| 1582 | struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX; |
| 1583 | |
| 1584 | bs->bvec_pool = mempool_create_slab_pool(pool_entries, bp->slab); |
| 1585 | if (!bs->bvec_pool) |
| 1586 | return -ENOMEM; |
| 1587 | |
| 1588 | return 0; |
| 1589 | } |
| 1590 | |
| 1591 | static void biovec_free_pools(struct bio_set *bs) |
| 1592 | { |
| 1593 | mempool_destroy(bs->bvec_pool); |
| 1594 | } |
| 1595 | |
| 1596 | void bioset_free(struct bio_set *bs) |
| 1597 | { |
| 1598 | if (bs->bio_pool) |
| 1599 | mempool_destroy(bs->bio_pool); |
| 1600 | |
| 1601 | bioset_integrity_free(bs); |
| 1602 | biovec_free_pools(bs); |
| 1603 | bio_put_slab(bs); |
| 1604 | |
| 1605 | kfree(bs); |
| 1606 | } |
| 1607 | EXPORT_SYMBOL(bioset_free); |
| 1608 | |
| 1609 | /** |
| 1610 | * bioset_create - Create a bio_set |
| 1611 | * @pool_size: Number of bio and bio_vecs to cache in the mempool |
| 1612 | * @front_pad: Number of bytes to allocate in front of the returned bio |
| 1613 | * |
| 1614 | * Description: |
| 1615 | * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller |
| 1616 | * to ask for a number of bytes to be allocated in front of the bio. |
| 1617 | * Front pad allocation is useful for embedding the bio inside |
| 1618 | * another structure, to avoid allocating extra data to go with the bio. |
| 1619 | * Note that the bio must be embedded at the END of that structure always, |
| 1620 | * or things will break badly. |
| 1621 | */ |
| 1622 | struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad) |
| 1623 | { |
| 1624 | unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec); |
| 1625 | struct bio_set *bs; |
| 1626 | |
| 1627 | bs = kzalloc(sizeof(*bs), GFP_KERNEL); |
| 1628 | if (!bs) |
| 1629 | return NULL; |
| 1630 | |
| 1631 | bs->front_pad = front_pad; |
| 1632 | |
| 1633 | bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad); |
| 1634 | if (!bs->bio_slab) { |
| 1635 | kfree(bs); |
| 1636 | return NULL; |
| 1637 | } |
| 1638 | |
| 1639 | bs->bio_pool = mempool_create_slab_pool(pool_size, bs->bio_slab); |
| 1640 | if (!bs->bio_pool) |
| 1641 | goto bad; |
| 1642 | |
| 1643 | if (!biovec_create_pools(bs, pool_size)) |
| 1644 | return bs; |
| 1645 | |
| 1646 | bad: |
| 1647 | bioset_free(bs); |
| 1648 | return NULL; |
| 1649 | } |
| 1650 | EXPORT_SYMBOL(bioset_create); |
| 1651 | |
| 1652 | #ifdef CONFIG_BLK_CGROUP |
| 1653 | /** |
| 1654 | * bio_associate_current - associate a bio with %current |
| 1655 | * @bio: target bio |
| 1656 | * |
| 1657 | * Associate @bio with %current if it hasn't been associated yet. Block |
| 1658 | * layer will treat @bio as if it were issued by %current no matter which |
| 1659 | * task actually issues it. |
| 1660 | * |
| 1661 | * This function takes an extra reference of @task's io_context and blkcg |
| 1662 | * which will be put when @bio is released. The caller must own @bio, |
| 1663 | * ensure %current->io_context exists, and is responsible for synchronizing |
| 1664 | * calls to this function. |
| 1665 | */ |
| 1666 | int bio_associate_current(struct bio *bio) |
| 1667 | { |
| 1668 | struct io_context *ioc; |
| 1669 | struct cgroup_subsys_state *css; |
| 1670 | |
| 1671 | if (bio->bi_ioc) |
| 1672 | return -EBUSY; |
| 1673 | |
| 1674 | ioc = current->io_context; |
| 1675 | if (!ioc) |
| 1676 | return -ENOENT; |
| 1677 | |
| 1678 | /* acquire active ref on @ioc and associate */ |
| 1679 | get_io_context_active(ioc); |
| 1680 | bio->bi_ioc = ioc; |
| 1681 | |
| 1682 | /* associate blkcg if exists */ |
| 1683 | rcu_read_lock(); |
| 1684 | css = task_subsys_state(current, blkio_subsys_id); |
| 1685 | if (css && css_tryget(css)) |
| 1686 | bio->bi_css = css; |
| 1687 | rcu_read_unlock(); |
| 1688 | |
| 1689 | return 0; |
| 1690 | } |
| 1691 | |
| 1692 | /** |
| 1693 | * bio_disassociate_task - undo bio_associate_current() |
| 1694 | * @bio: target bio |
| 1695 | */ |
| 1696 | void bio_disassociate_task(struct bio *bio) |
| 1697 | { |
| 1698 | if (bio->bi_ioc) { |
| 1699 | put_io_context(bio->bi_ioc); |
| 1700 | bio->bi_ioc = NULL; |
| 1701 | } |
| 1702 | if (bio->bi_css) { |
| 1703 | css_put(bio->bi_css); |
| 1704 | bio->bi_css = NULL; |
| 1705 | } |
| 1706 | } |
| 1707 | |
| 1708 | #endif /* CONFIG_BLK_CGROUP */ |
| 1709 | |
| 1710 | static void __init biovec_init_slabs(void) |
| 1711 | { |
| 1712 | int i; |
| 1713 | |
| 1714 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { |
| 1715 | int size; |
| 1716 | struct biovec_slab *bvs = bvec_slabs + i; |
| 1717 | |
| 1718 | if (bvs->nr_vecs <= BIO_INLINE_VECS) { |
| 1719 | bvs->slab = NULL; |
| 1720 | continue; |
| 1721 | } |
| 1722 | |
| 1723 | size = bvs->nr_vecs * sizeof(struct bio_vec); |
| 1724 | bvs->slab = kmem_cache_create(bvs->name, size, 0, |
| 1725 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
| 1726 | } |
| 1727 | } |
| 1728 | |
| 1729 | static int __init init_bio(void) |
| 1730 | { |
| 1731 | bio_slab_max = 2; |
| 1732 | bio_slab_nr = 0; |
| 1733 | bio_slabs = kzalloc(bio_slab_max * sizeof(struct bio_slab), GFP_KERNEL); |
| 1734 | if (!bio_slabs) |
| 1735 | panic("bio: can't allocate bios\n"); |
| 1736 | |
| 1737 | bio_integrity_init(); |
| 1738 | biovec_init_slabs(); |
| 1739 | |
| 1740 | fs_bio_set = bioset_create(BIO_POOL_SIZE, 0); |
| 1741 | if (!fs_bio_set) |
| 1742 | panic("bio: can't allocate bios\n"); |
| 1743 | |
| 1744 | if (bioset_integrity_create(fs_bio_set, BIO_POOL_SIZE)) |
| 1745 | panic("bio: can't create integrity pool\n"); |
| 1746 | |
| 1747 | bio_split_pool = mempool_create_kmalloc_pool(BIO_SPLIT_ENTRIES, |
| 1748 | sizeof(struct bio_pair)); |
| 1749 | if (!bio_split_pool) |
| 1750 | panic("bio: can't create split pool\n"); |
| 1751 | |
| 1752 | return 0; |
| 1753 | } |
| 1754 | subsys_initcall(init_bio); |