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> |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 29 | #include <scsi/sg.h> /* for struct sg_iovec */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 31 | static struct kmem_cache *bio_slab __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
Eric Dumazet | fa3536c | 2006-03-26 01:37:24 -0800 | [diff] [blame] | 33 | mempool_t *bio_split_pool __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | /* |
| 36 | * if you change this list, also change bvec_alloc or things will |
| 37 | * break badly! cannot be bigger than what you can fit into an |
| 38 | * unsigned short |
| 39 | */ |
| 40 | |
| 41 | #define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) } |
Christoph Lameter | 6c03652 | 2005-07-07 17:56:59 -0700 | [diff] [blame] | 42 | static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES), |
| 44 | }; |
| 45 | #undef BV |
| 46 | |
| 47 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | * fs_bio_set is the bio_set containing bio and iovec memory pools used by |
| 49 | * IO code that does not need private memory pools. |
| 50 | */ |
Martin K. Petersen | 51d654e | 2008-06-17 18:59:56 +0200 | [diff] [blame] | 51 | struct bio_set *fs_bio_set; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 53 | unsigned int bvec_nr_vecs(unsigned short idx) |
| 54 | { |
| 55 | return bvec_slabs[idx].nr_vecs; |
| 56 | } |
| 57 | |
Martin K. Petersen | 51d654e | 2008-06-17 18:59:56 +0200 | [diff] [blame] | 58 | struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, struct bio_set *bs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | { |
| 60 | struct bio_vec *bvl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | |
| 62 | /* |
| 63 | * see comment near bvec_array define! |
| 64 | */ |
| 65 | switch (nr) { |
| 66 | case 1 : *idx = 0; break; |
| 67 | case 2 ... 4: *idx = 1; break; |
| 68 | case 5 ... 16: *idx = 2; break; |
| 69 | case 17 ... 64: *idx = 3; break; |
| 70 | case 65 ... 128: *idx = 4; break; |
| 71 | case 129 ... BIO_MAX_PAGES: *idx = 5; break; |
| 72 | default: |
| 73 | return NULL; |
| 74 | } |
| 75 | /* |
| 76 | * idx now points to the pool we want to allocate from |
| 77 | */ |
| 78 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | bvl = mempool_alloc(bs->bvec_pools[*idx], gfp_mask); |
Andreas Mohr | bf02c08 | 2006-10-11 01:22:24 -0700 | [diff] [blame] | 80 | if (bvl) { |
| 81 | struct biovec_slab *bp = bvec_slabs + *idx; |
| 82 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | memset(bvl, 0, bp->nr_vecs * sizeof(struct bio_vec)); |
Andreas Mohr | bf02c08 | 2006-10-11 01:22:24 -0700 | [diff] [blame] | 84 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | |
| 86 | return bvl; |
| 87 | } |
| 88 | |
Peter Osterlund | 3676347 | 2005-09-06 15:16:42 -0700 | [diff] [blame] | 89 | void bio_free(struct bio *bio, struct bio_set *bio_set) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | { |
Jens Axboe | 992c5dd | 2007-07-18 13:18:08 +0200 | [diff] [blame] | 91 | if (bio->bi_io_vec) { |
| 92 | const int pool_idx = BIO_POOL_IDX(bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | |
Jens Axboe | 992c5dd | 2007-07-18 13:18:08 +0200 | [diff] [blame] | 94 | BIO_BUG_ON(pool_idx >= BIOVEC_NR_POOLS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | |
Jens Axboe | 992c5dd | 2007-07-18 13:18:08 +0200 | [diff] [blame] | 96 | mempool_free(bio->bi_io_vec, bio_set->bvec_pools[pool_idx]); |
| 97 | } |
| 98 | |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 99 | if (bio_integrity(bio)) |
| 100 | bio_integrity_free(bio, bio_set); |
| 101 | |
Peter Osterlund | 3676347 | 2005-09-06 15:16:42 -0700 | [diff] [blame] | 102 | mempool_free(bio, bio_set->bio_pool); |
| 103 | } |
| 104 | |
| 105 | /* |
| 106 | * default destructor for a bio allocated with bio_alloc_bioset() |
| 107 | */ |
| 108 | static void bio_fs_destructor(struct bio *bio) |
| 109 | { |
| 110 | bio_free(bio, fs_bio_set); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | } |
| 112 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 113 | void bio_init(struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | { |
Jens Axboe | 2b94de5 | 2007-07-18 13:14:03 +0200 | [diff] [blame] | 115 | memset(bio, 0, sizeof(*bio)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | bio->bi_flags = 1 << BIO_UPTODATE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | atomic_set(&bio->bi_cnt, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | } |
| 119 | |
| 120 | /** |
| 121 | * bio_alloc_bioset - allocate a bio for I/O |
| 122 | * @gfp_mask: the GFP_ mask given to the slab allocator |
| 123 | * @nr_iovecs: number of iovecs to pre-allocate |
Martin Waitz | 67be2dd | 2005-05-01 08:59:26 -0700 | [diff] [blame] | 124 | * @bs: the bio_set to allocate from |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | * |
| 126 | * Description: |
| 127 | * bio_alloc_bioset will first try it's on mempool to satisfy the allocation. |
| 128 | * If %__GFP_WAIT is set then we will block on the internal pool waiting |
| 129 | * for a &struct bio to become free. |
| 130 | * |
| 131 | * allocate bio and iovecs from the memory pools specified by the |
| 132 | * bio_set structure. |
| 133 | **/ |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 134 | 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] | 135 | { |
| 136 | struct bio *bio = mempool_alloc(bs->bio_pool, gfp_mask); |
| 137 | |
| 138 | if (likely(bio)) { |
| 139 | struct bio_vec *bvl = NULL; |
| 140 | |
| 141 | bio_init(bio); |
| 142 | if (likely(nr_iovecs)) { |
Jens Axboe | eeae1d4 | 2008-05-07 13:26:27 +0200 | [diff] [blame] | 143 | unsigned long uninitialized_var(idx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | |
| 145 | bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs); |
| 146 | if (unlikely(!bvl)) { |
| 147 | mempool_free(bio, bs->bio_pool); |
| 148 | bio = NULL; |
| 149 | goto out; |
| 150 | } |
| 151 | bio->bi_flags |= idx << BIO_POOL_OFFSET; |
| 152 | bio->bi_max_vecs = bvec_slabs[idx].nr_vecs; |
| 153 | } |
| 154 | bio->bi_io_vec = bvl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | } |
| 156 | out: |
| 157 | return bio; |
| 158 | } |
| 159 | |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 160 | struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | { |
Peter Osterlund | 3676347 | 2005-09-06 15:16:42 -0700 | [diff] [blame] | 162 | struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set); |
| 163 | |
| 164 | if (bio) |
| 165 | bio->bi_destructor = bio_fs_destructor; |
| 166 | |
| 167 | return bio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | } |
| 169 | |
| 170 | void zero_fill_bio(struct bio *bio) |
| 171 | { |
| 172 | unsigned long flags; |
| 173 | struct bio_vec *bv; |
| 174 | int i; |
| 175 | |
| 176 | bio_for_each_segment(bv, bio, i) { |
| 177 | char *data = bvec_kmap_irq(bv, &flags); |
| 178 | memset(data, 0, bv->bv_len); |
| 179 | flush_dcache_page(bv->bv_page); |
| 180 | bvec_kunmap_irq(data, &flags); |
| 181 | } |
| 182 | } |
| 183 | EXPORT_SYMBOL(zero_fill_bio); |
| 184 | |
| 185 | /** |
| 186 | * bio_put - release a reference to a bio |
| 187 | * @bio: bio to release reference to |
| 188 | * |
| 189 | * Description: |
| 190 | * Put a reference to a &struct bio, either one you have gotten with |
| 191 | * bio_alloc or bio_get. The last put of a bio will free it. |
| 192 | **/ |
| 193 | void bio_put(struct bio *bio) |
| 194 | { |
| 195 | BIO_BUG_ON(!atomic_read(&bio->bi_cnt)); |
| 196 | |
| 197 | /* |
| 198 | * last put frees it |
| 199 | */ |
| 200 | if (atomic_dec_and_test(&bio->bi_cnt)) { |
| 201 | bio->bi_next = NULL; |
| 202 | bio->bi_destructor(bio); |
| 203 | } |
| 204 | } |
| 205 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 206 | inline int bio_phys_segments(struct request_queue *q, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | { |
| 208 | if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) |
| 209 | blk_recount_segments(q, bio); |
| 210 | |
| 211 | return bio->bi_phys_segments; |
| 212 | } |
| 213 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 214 | inline int bio_hw_segments(struct request_queue *q, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | { |
| 216 | if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) |
| 217 | blk_recount_segments(q, bio); |
| 218 | |
| 219 | return bio->bi_hw_segments; |
| 220 | } |
| 221 | |
| 222 | /** |
| 223 | * __bio_clone - clone a bio |
| 224 | * @bio: destination bio |
| 225 | * @bio_src: bio to clone |
| 226 | * |
| 227 | * Clone a &bio. Caller will own the returned bio, but not |
| 228 | * the actual data it points to. Reference count of returned |
| 229 | * bio will be one. |
| 230 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 231 | void __bio_clone(struct bio *bio, struct bio *bio_src) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | { |
Andrew Morton | e525e15 | 2005-08-07 09:42:12 -0700 | [diff] [blame] | 233 | memcpy(bio->bi_io_vec, bio_src->bi_io_vec, |
| 234 | bio_src->bi_max_vecs * sizeof(struct bio_vec)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | |
Jens Axboe | 5d84070 | 2008-01-25 12:44:44 +0100 | [diff] [blame] | 236 | /* |
| 237 | * most users will be overriding ->bi_bdev with a new target, |
| 238 | * so we don't set nor calculate new physical/hw segment counts here |
| 239 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | bio->bi_sector = bio_src->bi_sector; |
| 241 | bio->bi_bdev = bio_src->bi_bdev; |
| 242 | bio->bi_flags |= 1 << BIO_CLONED; |
| 243 | bio->bi_rw = bio_src->bi_rw; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | bio->bi_vcnt = bio_src->bi_vcnt; |
| 245 | bio->bi_size = bio_src->bi_size; |
Andrew Morton | a5453be | 2005-07-28 01:07:18 -0700 | [diff] [blame] | 246 | bio->bi_idx = bio_src->bi_idx; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | } |
| 248 | |
| 249 | /** |
| 250 | * bio_clone - clone a bio |
| 251 | * @bio: bio to clone |
| 252 | * @gfp_mask: allocation priority |
| 253 | * |
| 254 | * Like __bio_clone, only also allocates the returned bio |
| 255 | */ |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 256 | struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | { |
| 258 | struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set); |
| 259 | |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 260 | if (!b) |
| 261 | return NULL; |
| 262 | |
| 263 | b->bi_destructor = bio_fs_destructor; |
| 264 | __bio_clone(b, bio); |
| 265 | |
| 266 | if (bio_integrity(bio)) { |
| 267 | int ret; |
| 268 | |
| 269 | ret = bio_integrity_clone(b, bio, fs_bio_set); |
| 270 | |
| 271 | if (ret < 0) |
| 272 | return NULL; |
Peter Osterlund | 3676347 | 2005-09-06 15:16:42 -0700 | [diff] [blame] | 273 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | |
| 275 | return b; |
| 276 | } |
| 277 | |
| 278 | /** |
| 279 | * bio_get_nr_vecs - return approx number of vecs |
| 280 | * @bdev: I/O target |
| 281 | * |
| 282 | * Return the approximate number of pages we can send to this target. |
| 283 | * There's no guarantee that you will be able to fit this number of pages |
| 284 | * into a bio, it does not account for dynamic restrictions that vary |
| 285 | * on offset. |
| 286 | */ |
| 287 | int bio_get_nr_vecs(struct block_device *bdev) |
| 288 | { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 289 | struct request_queue *q = bdev_get_queue(bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | int nr_pages; |
| 291 | |
| 292 | nr_pages = ((q->max_sectors << 9) + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 293 | if (nr_pages > q->max_phys_segments) |
| 294 | nr_pages = q->max_phys_segments; |
| 295 | if (nr_pages > q->max_hw_segments) |
| 296 | nr_pages = q->max_hw_segments; |
| 297 | |
| 298 | return nr_pages; |
| 299 | } |
| 300 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 301 | 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] | 302 | *page, unsigned int len, unsigned int offset, |
| 303 | unsigned short max_sectors) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | { |
| 305 | int retried_segments = 0; |
| 306 | struct bio_vec *bvec; |
| 307 | |
| 308 | /* |
| 309 | * cloned bio must not modify vec list |
| 310 | */ |
| 311 | if (unlikely(bio_flagged(bio, BIO_CLONED))) |
| 312 | return 0; |
| 313 | |
Jens Axboe | 80cfd54 | 2006-01-06 09:43:28 +0100 | [diff] [blame] | 314 | if (((bio->bi_size + len) >> 9) > max_sectors) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | return 0; |
| 316 | |
Jens Axboe | 80cfd54 | 2006-01-06 09:43:28 +0100 | [diff] [blame] | 317 | /* |
| 318 | * For filesystems with a blocksize smaller than the pagesize |
| 319 | * we will often be called with the same page as last time and |
| 320 | * a consecutive offset. Optimize this special case. |
| 321 | */ |
| 322 | if (bio->bi_vcnt > 0) { |
| 323 | struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1]; |
| 324 | |
| 325 | if (page == prev->bv_page && |
| 326 | offset == prev->bv_offset + prev->bv_len) { |
| 327 | prev->bv_len += len; |
Alasdair G Kergon | cc371e6 | 2008-07-03 09:53:43 +0200 | [diff] [blame] | 328 | |
| 329 | if (q->merge_bvec_fn) { |
| 330 | struct bvec_merge_data bvm = { |
| 331 | .bi_bdev = bio->bi_bdev, |
| 332 | .bi_sector = bio->bi_sector, |
| 333 | .bi_size = bio->bi_size, |
| 334 | .bi_rw = bio->bi_rw, |
| 335 | }; |
| 336 | |
| 337 | if (q->merge_bvec_fn(q, &bvm, prev) < len) { |
| 338 | prev->bv_len -= len; |
| 339 | return 0; |
| 340 | } |
Jens Axboe | 80cfd54 | 2006-01-06 09:43:28 +0100 | [diff] [blame] | 341 | } |
| 342 | |
| 343 | goto done; |
| 344 | } |
| 345 | } |
| 346 | |
| 347 | if (bio->bi_vcnt >= bio->bi_max_vecs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | return 0; |
| 349 | |
| 350 | /* |
| 351 | * we might lose a segment or two here, but rather that than |
| 352 | * make this too complex. |
| 353 | */ |
| 354 | |
| 355 | while (bio->bi_phys_segments >= q->max_phys_segments |
| 356 | || bio->bi_hw_segments >= q->max_hw_segments |
| 357 | || BIOVEC_VIRT_OVERSIZE(bio->bi_size)) { |
| 358 | |
| 359 | if (retried_segments) |
| 360 | return 0; |
| 361 | |
| 362 | retried_segments = 1; |
| 363 | blk_recount_segments(q, bio); |
| 364 | } |
| 365 | |
| 366 | /* |
| 367 | * setup the new entry, we might clear it again later if we |
| 368 | * cannot add the page |
| 369 | */ |
| 370 | bvec = &bio->bi_io_vec[bio->bi_vcnt]; |
| 371 | bvec->bv_page = page; |
| 372 | bvec->bv_len = len; |
| 373 | bvec->bv_offset = offset; |
| 374 | |
| 375 | /* |
| 376 | * if queue has other restrictions (eg varying max sector size |
| 377 | * depending on offset), it can specify a merge_bvec_fn in the |
| 378 | * queue to get further control |
| 379 | */ |
| 380 | if (q->merge_bvec_fn) { |
Alasdair G Kergon | cc371e6 | 2008-07-03 09:53:43 +0200 | [diff] [blame] | 381 | struct bvec_merge_data bvm = { |
| 382 | .bi_bdev = bio->bi_bdev, |
| 383 | .bi_sector = bio->bi_sector, |
| 384 | .bi_size = bio->bi_size, |
| 385 | .bi_rw = bio->bi_rw, |
| 386 | }; |
| 387 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | /* |
| 389 | * merge_bvec_fn() returns number of bytes it can accept |
| 390 | * at this offset |
| 391 | */ |
Alasdair G Kergon | cc371e6 | 2008-07-03 09:53:43 +0200 | [diff] [blame] | 392 | if (q->merge_bvec_fn(q, &bvm, bvec) < len) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 393 | bvec->bv_page = NULL; |
| 394 | bvec->bv_len = 0; |
| 395 | bvec->bv_offset = 0; |
| 396 | return 0; |
| 397 | } |
| 398 | } |
| 399 | |
| 400 | /* If we may be able to merge these biovecs, force a recount */ |
| 401 | if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec) || |
| 402 | BIOVEC_VIRT_MERGEABLE(bvec-1, bvec))) |
| 403 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); |
| 404 | |
| 405 | bio->bi_vcnt++; |
| 406 | bio->bi_phys_segments++; |
| 407 | bio->bi_hw_segments++; |
Jens Axboe | 80cfd54 | 2006-01-06 09:43:28 +0100 | [diff] [blame] | 408 | done: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | bio->bi_size += len; |
| 410 | return len; |
| 411 | } |
| 412 | |
| 413 | /** |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 414 | * bio_add_pc_page - attempt to add page to bio |
Jens Axboe | fddfdea | 2006-01-31 15:24:34 +0100 | [diff] [blame] | 415 | * @q: the target queue |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 416 | * @bio: destination bio |
| 417 | * @page: page to add |
| 418 | * @len: vec entry length |
| 419 | * @offset: vec entry offset |
| 420 | * |
| 421 | * Attempt to add a page to the bio_vec maplist. This can fail for a |
| 422 | * number of reasons, such as the bio being full or target block |
| 423 | * device limitations. The target block device must allow bio's |
| 424 | * smaller than PAGE_SIZE, so it is always possible to add a single |
| 425 | * page to an empty bio. This should only be used by REQ_PC bios. |
| 426 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 427 | 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] | 428 | unsigned int len, unsigned int offset) |
| 429 | { |
Mike Christie | defd94b | 2005-12-05 02:37:06 -0600 | [diff] [blame] | 430 | 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] | 431 | } |
| 432 | |
| 433 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | * bio_add_page - attempt to add page to bio |
| 435 | * @bio: destination bio |
| 436 | * @page: page to add |
| 437 | * @len: vec entry length |
| 438 | * @offset: vec entry offset |
| 439 | * |
| 440 | * Attempt to add a page to the bio_vec maplist. This can fail for a |
| 441 | * number of reasons, such as the bio being full or target block |
| 442 | * device limitations. The target block device must allow bio's |
| 443 | * smaller than PAGE_SIZE, so it is always possible to add a single |
| 444 | * page to an empty bio. |
| 445 | */ |
| 446 | int bio_add_page(struct bio *bio, struct page *page, unsigned int len, |
| 447 | unsigned int offset) |
| 448 | { |
Mike Christie | defd94b | 2005-12-05 02:37:06 -0600 | [diff] [blame] | 449 | struct request_queue *q = bdev_get_queue(bio->bi_bdev); |
| 450 | return __bio_add_page(q, bio, page, len, offset, q->max_sectors); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | } |
| 452 | |
| 453 | struct bio_map_data { |
| 454 | struct bio_vec *iovecs; |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 455 | int nr_sgvecs; |
| 456 | struct sg_iovec *sgvecs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 457 | }; |
| 458 | |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 459 | static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio, |
| 460 | struct sg_iovec *iov, int iov_count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 461 | { |
| 462 | 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] | 463 | memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count); |
| 464 | bmd->nr_sgvecs = iov_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | bio->bi_private = bmd; |
| 466 | } |
| 467 | |
| 468 | static void bio_free_map_data(struct bio_map_data *bmd) |
| 469 | { |
| 470 | kfree(bmd->iovecs); |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 471 | kfree(bmd->sgvecs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | kfree(bmd); |
| 473 | } |
| 474 | |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 475 | static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | { |
| 477 | struct bio_map_data *bmd = kmalloc(sizeof(*bmd), GFP_KERNEL); |
| 478 | |
| 479 | if (!bmd) |
| 480 | return NULL; |
| 481 | |
| 482 | bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, GFP_KERNEL); |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 483 | if (!bmd->iovecs) { |
| 484 | kfree(bmd); |
| 485 | return NULL; |
| 486 | } |
| 487 | |
| 488 | bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, GFP_KERNEL); |
| 489 | if (bmd->sgvecs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | return bmd; |
| 491 | |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 492 | kfree(bmd->iovecs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | kfree(bmd); |
| 494 | return NULL; |
| 495 | } |
| 496 | |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 497 | static int __bio_copy_iov(struct bio *bio, struct sg_iovec *iov, int iov_count, |
| 498 | int uncopy) |
| 499 | { |
| 500 | int ret = 0, i; |
| 501 | struct bio_vec *bvec; |
| 502 | int iov_idx = 0; |
| 503 | unsigned int iov_off = 0; |
| 504 | int read = bio_data_dir(bio) == READ; |
| 505 | |
| 506 | __bio_for_each_segment(bvec, bio, i, 0) { |
| 507 | char *bv_addr = page_address(bvec->bv_page); |
| 508 | unsigned int bv_len = bvec->bv_len; |
| 509 | |
| 510 | while (bv_len && iov_idx < iov_count) { |
| 511 | unsigned int bytes; |
| 512 | char *iov_addr; |
| 513 | |
| 514 | bytes = min_t(unsigned int, |
| 515 | iov[iov_idx].iov_len - iov_off, bv_len); |
| 516 | iov_addr = iov[iov_idx].iov_base + iov_off; |
| 517 | |
| 518 | if (!ret) { |
| 519 | if (!read && !uncopy) |
| 520 | ret = copy_from_user(bv_addr, iov_addr, |
| 521 | bytes); |
| 522 | if (read && uncopy) |
| 523 | ret = copy_to_user(iov_addr, bv_addr, |
| 524 | bytes); |
| 525 | |
| 526 | if (ret) |
| 527 | ret = -EFAULT; |
| 528 | } |
| 529 | |
| 530 | bv_len -= bytes; |
| 531 | bv_addr += bytes; |
| 532 | iov_addr += bytes; |
| 533 | iov_off += bytes; |
| 534 | |
| 535 | if (iov[iov_idx].iov_len == iov_off) { |
| 536 | iov_idx++; |
| 537 | iov_off = 0; |
| 538 | } |
| 539 | } |
| 540 | |
| 541 | if (uncopy) |
| 542 | __free_page(bvec->bv_page); |
| 543 | } |
| 544 | |
| 545 | return ret; |
| 546 | } |
| 547 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | /** |
| 549 | * bio_uncopy_user - finish previously mapped bio |
| 550 | * @bio: bio being terminated |
| 551 | * |
| 552 | * Free pages allocated from bio_copy_user() and write back data |
| 553 | * to user space in case of a read. |
| 554 | */ |
| 555 | int bio_uncopy_user(struct bio *bio) |
| 556 | { |
| 557 | struct bio_map_data *bmd = bio->bi_private; |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 558 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 560 | ret = __bio_copy_iov(bio, bmd->sgvecs, bmd->nr_sgvecs, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 561 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | bio_free_map_data(bmd); |
| 563 | bio_put(bio); |
| 564 | return ret; |
| 565 | } |
| 566 | |
| 567 | /** |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 568 | * bio_copy_user_iov - copy user data to bio |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | * @q: destination block queue |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 570 | * @iov: the iovec. |
| 571 | * @iov_count: number of elements in the iovec |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | * @write_to_vm: bool indicating writing to pages or not |
| 573 | * |
| 574 | * Prepares and returns a bio for indirect user io, bouncing data |
| 575 | * to/from kernel pages as necessary. Must be paired with |
| 576 | * call bio_uncopy_user() on io completion. |
| 577 | */ |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 578 | struct bio *bio_copy_user_iov(struct request_queue *q, struct sg_iovec *iov, |
| 579 | int iov_count, int write_to_vm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 580 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | struct bio_map_data *bmd; |
| 582 | struct bio_vec *bvec; |
| 583 | struct page *page; |
| 584 | struct bio *bio; |
| 585 | int i, ret; |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 586 | int nr_pages = 0; |
| 587 | unsigned int len = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 589 | for (i = 0; i < iov_count; i++) { |
| 590 | unsigned long uaddr; |
| 591 | unsigned long end; |
| 592 | unsigned long start; |
| 593 | |
| 594 | uaddr = (unsigned long)iov[i].iov_base; |
| 595 | end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 596 | start = uaddr >> PAGE_SHIFT; |
| 597 | |
| 598 | nr_pages += end - start; |
| 599 | len += iov[i].iov_len; |
| 600 | } |
| 601 | |
| 602 | bmd = bio_alloc_map_data(nr_pages, iov_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 603 | if (!bmd) |
| 604 | return ERR_PTR(-ENOMEM); |
| 605 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 606 | ret = -ENOMEM; |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 607 | bio = bio_alloc(GFP_KERNEL, nr_pages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 608 | if (!bio) |
| 609 | goto out_bmd; |
| 610 | |
| 611 | bio->bi_rw |= (!write_to_vm << BIO_RW); |
| 612 | |
| 613 | ret = 0; |
| 614 | while (len) { |
| 615 | unsigned int bytes = PAGE_SIZE; |
| 616 | |
| 617 | if (bytes > len) |
| 618 | bytes = len; |
| 619 | |
| 620 | page = alloc_page(q->bounce_gfp | GFP_KERNEL); |
| 621 | if (!page) { |
| 622 | ret = -ENOMEM; |
| 623 | break; |
| 624 | } |
| 625 | |
Mike Christie | 0e75f90 | 2006-12-01 10:40:55 +0100 | [diff] [blame] | 626 | if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 628 | |
| 629 | len -= bytes; |
| 630 | } |
| 631 | |
| 632 | if (ret) |
| 633 | goto cleanup; |
| 634 | |
| 635 | /* |
| 636 | * success |
| 637 | */ |
| 638 | if (!write_to_vm) { |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 639 | ret = __bio_copy_iov(bio, iov, iov_count, 0); |
| 640 | if (ret) |
| 641 | goto cleanup; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 642 | } |
| 643 | |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 644 | bio_set_map_data(bmd, bio, iov, iov_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | return bio; |
| 646 | cleanup: |
| 647 | bio_for_each_segment(bvec, bio, i) |
| 648 | __free_page(bvec->bv_page); |
| 649 | |
| 650 | bio_put(bio); |
| 651 | out_bmd: |
| 652 | bio_free_map_data(bmd); |
| 653 | return ERR_PTR(ret); |
| 654 | } |
| 655 | |
FUJITA Tomonori | c5dec1c | 2008-04-11 12:56:49 +0200 | [diff] [blame] | 656 | /** |
| 657 | * bio_copy_user - copy user data to bio |
| 658 | * @q: destination block queue |
| 659 | * @uaddr: start of user address |
| 660 | * @len: length in bytes |
| 661 | * @write_to_vm: bool indicating writing to pages or not |
| 662 | * |
| 663 | * Prepares and returns a bio for indirect user io, bouncing data |
| 664 | * to/from kernel pages as necessary. Must be paired with |
| 665 | * call bio_uncopy_user() on io completion. |
| 666 | */ |
| 667 | struct bio *bio_copy_user(struct request_queue *q, unsigned long uaddr, |
| 668 | unsigned int len, int write_to_vm) |
| 669 | { |
| 670 | struct sg_iovec iov; |
| 671 | |
| 672 | iov.iov_base = (void __user *)uaddr; |
| 673 | iov.iov_len = len; |
| 674 | |
| 675 | return bio_copy_user_iov(q, &iov, 1, write_to_vm); |
| 676 | } |
| 677 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 678 | static struct bio *__bio_map_user_iov(struct request_queue *q, |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 679 | struct block_device *bdev, |
| 680 | struct sg_iovec *iov, int iov_count, |
| 681 | int write_to_vm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 682 | { |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 683 | int i, j; |
| 684 | int nr_pages = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 685 | struct page **pages; |
| 686 | struct bio *bio; |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 687 | int cur_page = 0; |
| 688 | int ret, offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 689 | |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 690 | for (i = 0; i < iov_count; i++) { |
| 691 | unsigned long uaddr = (unsigned long)iov[i].iov_base; |
| 692 | unsigned long len = iov[i].iov_len; |
| 693 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 694 | unsigned long start = uaddr >> PAGE_SHIFT; |
| 695 | |
| 696 | nr_pages += end - start; |
| 697 | /* |
Mike Christie | ad2d722 | 2006-12-01 10:40:20 +0100 | [diff] [blame] | 698 | * buffer must be aligned to at least hardsector size for now |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 699 | */ |
Mike Christie | ad2d722 | 2006-12-01 10:40:20 +0100 | [diff] [blame] | 700 | if (uaddr & queue_dma_alignment(q)) |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 701 | return ERR_PTR(-EINVAL); |
| 702 | } |
| 703 | |
| 704 | if (!nr_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | return ERR_PTR(-EINVAL); |
| 706 | |
| 707 | bio = bio_alloc(GFP_KERNEL, nr_pages); |
| 708 | if (!bio) |
| 709 | return ERR_PTR(-ENOMEM); |
| 710 | |
| 711 | ret = -ENOMEM; |
Oliver Neukum | 11b0b5a | 2006-03-25 03:08:13 -0800 | [diff] [blame] | 712 | pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 713 | if (!pages) |
| 714 | goto out; |
| 715 | |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 716 | for (i = 0; i < iov_count; i++) { |
| 717 | unsigned long uaddr = (unsigned long)iov[i].iov_base; |
| 718 | unsigned long len = iov[i].iov_len; |
| 719 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 720 | unsigned long start = uaddr >> PAGE_SHIFT; |
| 721 | const int local_nr_pages = end - start; |
| 722 | const int page_limit = cur_page + local_nr_pages; |
| 723 | |
Nick Piggin | f5dd33c | 2008-07-25 19:45:25 -0700 | [diff] [blame^] | 724 | ret = get_user_pages_fast(uaddr, local_nr_pages, |
| 725 | write_to_vm, &pages[cur_page]); |
Jens Axboe | 9917215 | 2006-06-16 13:02:29 +0200 | [diff] [blame] | 726 | if (ret < local_nr_pages) { |
| 727 | ret = -EFAULT; |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 728 | goto out_unmap; |
Jens Axboe | 9917215 | 2006-06-16 13:02:29 +0200 | [diff] [blame] | 729 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 730 | |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 731 | offset = uaddr & ~PAGE_MASK; |
| 732 | for (j = cur_page; j < page_limit; j++) { |
| 733 | unsigned int bytes = PAGE_SIZE - offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 735 | if (len <= 0) |
| 736 | break; |
| 737 | |
| 738 | if (bytes > len) |
| 739 | bytes = len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 741 | /* |
| 742 | * sorry... |
| 743 | */ |
Mike Christie | defd94b | 2005-12-05 02:37:06 -0600 | [diff] [blame] | 744 | if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < |
| 745 | bytes) |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 746 | break; |
| 747 | |
| 748 | len -= bytes; |
| 749 | offset = 0; |
| 750 | } |
| 751 | |
| 752 | cur_page = j; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | /* |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 754 | * release the pages we didn't map into the bio, if any |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | */ |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 756 | while (j < page_limit) |
| 757 | page_cache_release(pages[j++]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 758 | } |
| 759 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | kfree(pages); |
| 761 | |
| 762 | /* |
| 763 | * set data direction, and check if mapped pages need bouncing |
| 764 | */ |
| 765 | if (!write_to_vm) |
| 766 | bio->bi_rw |= (1 << BIO_RW); |
| 767 | |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 768 | bio->bi_bdev = bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 769 | bio->bi_flags |= (1 << BIO_USER_MAPPED); |
| 770 | return bio; |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 771 | |
| 772 | out_unmap: |
| 773 | for (i = 0; i < nr_pages; i++) { |
| 774 | if(!pages[i]) |
| 775 | break; |
| 776 | page_cache_release(pages[i]); |
| 777 | } |
| 778 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 779 | kfree(pages); |
| 780 | bio_put(bio); |
| 781 | return ERR_PTR(ret); |
| 782 | } |
| 783 | |
| 784 | /** |
| 785 | * bio_map_user - map user address into bio |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 786 | * @q: the struct request_queue for the bio |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | * @bdev: destination block device |
| 788 | * @uaddr: start of user address |
| 789 | * @len: length in bytes |
| 790 | * @write_to_vm: bool indicating writing to pages or not |
| 791 | * |
| 792 | * Map the user space address into a bio suitable for io to a block |
| 793 | * device. Returns an error pointer in case of error. |
| 794 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 795 | struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | unsigned long uaddr, unsigned int len, int write_to_vm) |
| 797 | { |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 798 | struct sg_iovec iov; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | |
viro@ZenIV.linux.org.uk | 3f70353 | 2005-09-09 16:53:56 +0100 | [diff] [blame] | 800 | iov.iov_base = (void __user *)uaddr; |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 801 | iov.iov_len = len; |
| 802 | |
| 803 | return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm); |
| 804 | } |
| 805 | |
| 806 | /** |
| 807 | * bio_map_user_iov - map user sg_iovec table into bio |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 808 | * @q: the struct request_queue for the bio |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 809 | * @bdev: destination block device |
| 810 | * @iov: the iovec. |
| 811 | * @iov_count: number of elements in the iovec |
| 812 | * @write_to_vm: bool indicating writing to pages or not |
| 813 | * |
| 814 | * Map the user space address into a bio suitable for io to a block |
| 815 | * device. Returns an error pointer in case of error. |
| 816 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 817 | 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] | 818 | struct sg_iovec *iov, int iov_count, |
| 819 | int write_to_vm) |
| 820 | { |
| 821 | struct bio *bio; |
James Bottomley | f1970ba | 2005-06-20 14:06:52 +0200 | [diff] [blame] | 822 | |
| 823 | bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 824 | |
| 825 | if (IS_ERR(bio)) |
| 826 | return bio; |
| 827 | |
| 828 | /* |
| 829 | * subtle -- if __bio_map_user() ended up bouncing a bio, |
| 830 | * it would normally disappear when its bi_end_io is run. |
| 831 | * however, we need it for the unmap, so grab an extra |
| 832 | * reference to it |
| 833 | */ |
| 834 | bio_get(bio); |
| 835 | |
Mike Christie | 0e75f90 | 2006-12-01 10:40:55 +0100 | [diff] [blame] | 836 | return bio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 837 | } |
| 838 | |
| 839 | static void __bio_unmap_user(struct bio *bio) |
| 840 | { |
| 841 | struct bio_vec *bvec; |
| 842 | int i; |
| 843 | |
| 844 | /* |
| 845 | * make sure we dirty pages we wrote to |
| 846 | */ |
| 847 | __bio_for_each_segment(bvec, bio, i, 0) { |
| 848 | if (bio_data_dir(bio) == READ) |
| 849 | set_page_dirty_lock(bvec->bv_page); |
| 850 | |
| 851 | page_cache_release(bvec->bv_page); |
| 852 | } |
| 853 | |
| 854 | bio_put(bio); |
| 855 | } |
| 856 | |
| 857 | /** |
| 858 | * bio_unmap_user - unmap a bio |
| 859 | * @bio: the bio being unmapped |
| 860 | * |
| 861 | * Unmap a bio previously mapped by bio_map_user(). Must be called with |
| 862 | * a process context. |
| 863 | * |
| 864 | * bio_unmap_user() may sleep. |
| 865 | */ |
| 866 | void bio_unmap_user(struct bio *bio) |
| 867 | { |
| 868 | __bio_unmap_user(bio); |
| 869 | bio_put(bio); |
| 870 | } |
| 871 | |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 872 | static void bio_map_kern_endio(struct bio *bio, int err) |
Jens Axboe | b823825 | 2005-06-20 14:05:27 +0200 | [diff] [blame] | 873 | { |
Jens Axboe | b823825 | 2005-06-20 14:05:27 +0200 | [diff] [blame] | 874 | bio_put(bio); |
Jens Axboe | b823825 | 2005-06-20 14:05:27 +0200 | [diff] [blame] | 875 | } |
| 876 | |
| 877 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 878 | static struct bio *__bio_map_kern(struct request_queue *q, void *data, |
Al Viro | 27496a8 | 2005-10-21 03:20:48 -0400 | [diff] [blame] | 879 | unsigned int len, gfp_t gfp_mask) |
Mike Christie | df46b9a | 2005-06-20 14:04:44 +0200 | [diff] [blame] | 880 | { |
| 881 | unsigned long kaddr = (unsigned long)data; |
| 882 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 883 | unsigned long start = kaddr >> PAGE_SHIFT; |
| 884 | const int nr_pages = end - start; |
| 885 | int offset, i; |
| 886 | struct bio *bio; |
| 887 | |
| 888 | bio = bio_alloc(gfp_mask, nr_pages); |
| 889 | if (!bio) |
| 890 | return ERR_PTR(-ENOMEM); |
| 891 | |
| 892 | offset = offset_in_page(kaddr); |
| 893 | for (i = 0; i < nr_pages; i++) { |
| 894 | unsigned int bytes = PAGE_SIZE - offset; |
| 895 | |
| 896 | if (len <= 0) |
| 897 | break; |
| 898 | |
| 899 | if (bytes > len) |
| 900 | bytes = len; |
| 901 | |
Mike Christie | defd94b | 2005-12-05 02:37:06 -0600 | [diff] [blame] | 902 | if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, |
| 903 | offset) < bytes) |
Mike Christie | df46b9a | 2005-06-20 14:04:44 +0200 | [diff] [blame] | 904 | break; |
| 905 | |
| 906 | data += bytes; |
| 907 | len -= bytes; |
| 908 | offset = 0; |
| 909 | } |
| 910 | |
Jens Axboe | b823825 | 2005-06-20 14:05:27 +0200 | [diff] [blame] | 911 | bio->bi_end_io = bio_map_kern_endio; |
Mike Christie | df46b9a | 2005-06-20 14:04:44 +0200 | [diff] [blame] | 912 | return bio; |
| 913 | } |
| 914 | |
| 915 | /** |
| 916 | * bio_map_kern - map kernel address into bio |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 917 | * @q: the struct request_queue for the bio |
Mike Christie | df46b9a | 2005-06-20 14:04:44 +0200 | [diff] [blame] | 918 | * @data: pointer to buffer to map |
| 919 | * @len: length in bytes |
| 920 | * @gfp_mask: allocation flags for bio allocation |
| 921 | * |
| 922 | * Map the kernel address into a bio suitable for io to a block |
| 923 | * device. Returns an error pointer in case of error. |
| 924 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 925 | 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] | 926 | gfp_t gfp_mask) |
Mike Christie | df46b9a | 2005-06-20 14:04:44 +0200 | [diff] [blame] | 927 | { |
| 928 | struct bio *bio; |
| 929 | |
| 930 | bio = __bio_map_kern(q, data, len, gfp_mask); |
| 931 | if (IS_ERR(bio)) |
| 932 | return bio; |
| 933 | |
| 934 | if (bio->bi_size == len) |
| 935 | return bio; |
| 936 | |
| 937 | /* |
| 938 | * Don't support partial mappings. |
| 939 | */ |
| 940 | bio_put(bio); |
| 941 | return ERR_PTR(-EINVAL); |
| 942 | } |
| 943 | |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 944 | static void bio_copy_kern_endio(struct bio *bio, int err) |
| 945 | { |
| 946 | struct bio_vec *bvec; |
| 947 | const int read = bio_data_dir(bio) == READ; |
| 948 | char *p = bio->bi_private; |
| 949 | int i; |
| 950 | |
| 951 | __bio_for_each_segment(bvec, bio, i, 0) { |
| 952 | char *addr = page_address(bvec->bv_page); |
| 953 | |
| 954 | if (read && !err) |
| 955 | memcpy(p, addr, bvec->bv_len); |
| 956 | |
| 957 | __free_page(bvec->bv_page); |
| 958 | p += bvec->bv_len; |
| 959 | } |
| 960 | |
| 961 | bio_put(bio); |
| 962 | } |
| 963 | |
| 964 | /** |
| 965 | * bio_copy_kern - copy kernel address into bio |
| 966 | * @q: the struct request_queue for the bio |
| 967 | * @data: pointer to buffer to copy |
| 968 | * @len: length in bytes |
| 969 | * @gfp_mask: allocation flags for bio and page allocation |
Randy Dunlap | ffee025 | 2008-04-30 09:08:54 +0200 | [diff] [blame] | 970 | * @reading: data direction is READ |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 971 | * |
| 972 | * copy the kernel address into a bio suitable for io to a block |
| 973 | * device. Returns an error pointer in case of error. |
| 974 | */ |
| 975 | struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, |
| 976 | gfp_t gfp_mask, int reading) |
| 977 | { |
| 978 | unsigned long kaddr = (unsigned long)data; |
| 979 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 980 | unsigned long start = kaddr >> PAGE_SHIFT; |
| 981 | const int nr_pages = end - start; |
| 982 | struct bio *bio; |
| 983 | struct bio_vec *bvec; |
| 984 | int i, ret; |
| 985 | |
| 986 | bio = bio_alloc(gfp_mask, nr_pages); |
| 987 | if (!bio) |
| 988 | return ERR_PTR(-ENOMEM); |
| 989 | |
| 990 | while (len) { |
| 991 | struct page *page; |
| 992 | unsigned int bytes = PAGE_SIZE; |
| 993 | |
| 994 | if (bytes > len) |
| 995 | bytes = len; |
| 996 | |
| 997 | page = alloc_page(q->bounce_gfp | gfp_mask); |
| 998 | if (!page) { |
| 999 | ret = -ENOMEM; |
| 1000 | goto cleanup; |
| 1001 | } |
| 1002 | |
| 1003 | if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) { |
| 1004 | ret = -EINVAL; |
| 1005 | goto cleanup; |
| 1006 | } |
| 1007 | |
| 1008 | len -= bytes; |
| 1009 | } |
| 1010 | |
| 1011 | if (!reading) { |
| 1012 | void *p = data; |
| 1013 | |
| 1014 | bio_for_each_segment(bvec, bio, i) { |
| 1015 | char *addr = page_address(bvec->bv_page); |
| 1016 | |
| 1017 | memcpy(addr, p, bvec->bv_len); |
| 1018 | p += bvec->bv_len; |
| 1019 | } |
| 1020 | } |
| 1021 | |
| 1022 | bio->bi_private = data; |
| 1023 | bio->bi_end_io = bio_copy_kern_endio; |
| 1024 | return bio; |
| 1025 | cleanup: |
| 1026 | bio_for_each_segment(bvec, bio, i) |
| 1027 | __free_page(bvec->bv_page); |
| 1028 | |
| 1029 | bio_put(bio); |
| 1030 | |
| 1031 | return ERR_PTR(ret); |
| 1032 | } |
| 1033 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1034 | /* |
| 1035 | * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions |
| 1036 | * for performing direct-IO in BIOs. |
| 1037 | * |
| 1038 | * The problem is that we cannot run set_page_dirty() from interrupt context |
| 1039 | * because the required locks are not interrupt-safe. So what we can do is to |
| 1040 | * mark the pages dirty _before_ performing IO. And in interrupt context, |
| 1041 | * check that the pages are still dirty. If so, fine. If not, redirty them |
| 1042 | * in process context. |
| 1043 | * |
| 1044 | * We special-case compound pages here: normally this means reads into hugetlb |
| 1045 | * pages. The logic in here doesn't really work right for compound pages |
| 1046 | * because the VM does not uniformly chase down the head page in all cases. |
| 1047 | * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't |
| 1048 | * handle them at all. So we skip compound pages here at an early stage. |
| 1049 | * |
| 1050 | * Note that this code is very hard to test under normal circumstances because |
| 1051 | * direct-io pins the pages with get_user_pages(). This makes |
| 1052 | * is_page_cache_freeable return false, and the VM will not clean the pages. |
| 1053 | * But other code (eg, pdflush) could clean the pages if they are mapped |
| 1054 | * pagecache. |
| 1055 | * |
| 1056 | * Simply disabling the call to bio_set_pages_dirty() is a good way to test the |
| 1057 | * deferred bio dirtying paths. |
| 1058 | */ |
| 1059 | |
| 1060 | /* |
| 1061 | * bio_set_pages_dirty() will mark all the bio's pages as dirty. |
| 1062 | */ |
| 1063 | void bio_set_pages_dirty(struct bio *bio) |
| 1064 | { |
| 1065 | struct bio_vec *bvec = bio->bi_io_vec; |
| 1066 | int i; |
| 1067 | |
| 1068 | for (i = 0; i < bio->bi_vcnt; i++) { |
| 1069 | struct page *page = bvec[i].bv_page; |
| 1070 | |
| 1071 | if (page && !PageCompound(page)) |
| 1072 | set_page_dirty_lock(page); |
| 1073 | } |
| 1074 | } |
| 1075 | |
Adrian Bunk | 86b6c7a | 2008-02-18 13:48:32 +0100 | [diff] [blame] | 1076 | static void bio_release_pages(struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1077 | { |
| 1078 | struct bio_vec *bvec = bio->bi_io_vec; |
| 1079 | int i; |
| 1080 | |
| 1081 | for (i = 0; i < bio->bi_vcnt; i++) { |
| 1082 | struct page *page = bvec[i].bv_page; |
| 1083 | |
| 1084 | if (page) |
| 1085 | put_page(page); |
| 1086 | } |
| 1087 | } |
| 1088 | |
| 1089 | /* |
| 1090 | * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. |
| 1091 | * If they are, then fine. If, however, some pages are clean then they must |
| 1092 | * have been written out during the direct-IO read. So we take another ref on |
| 1093 | * the BIO and the offending pages and re-dirty the pages in process context. |
| 1094 | * |
| 1095 | * It is expected that bio_check_pages_dirty() will wholly own the BIO from |
| 1096 | * here on. It will run one page_cache_release() against each page and will |
| 1097 | * run one bio_put() against the BIO. |
| 1098 | */ |
| 1099 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 1100 | static void bio_dirty_fn(struct work_struct *work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1101 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 1102 | static DECLARE_WORK(bio_dirty_work, bio_dirty_fn); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1103 | static DEFINE_SPINLOCK(bio_dirty_lock); |
| 1104 | static struct bio *bio_dirty_list; |
| 1105 | |
| 1106 | /* |
| 1107 | * This runs in process context |
| 1108 | */ |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 1109 | static void bio_dirty_fn(struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1110 | { |
| 1111 | unsigned long flags; |
| 1112 | struct bio *bio; |
| 1113 | |
| 1114 | spin_lock_irqsave(&bio_dirty_lock, flags); |
| 1115 | bio = bio_dirty_list; |
| 1116 | bio_dirty_list = NULL; |
| 1117 | spin_unlock_irqrestore(&bio_dirty_lock, flags); |
| 1118 | |
| 1119 | while (bio) { |
| 1120 | struct bio *next = bio->bi_private; |
| 1121 | |
| 1122 | bio_set_pages_dirty(bio); |
| 1123 | bio_release_pages(bio); |
| 1124 | bio_put(bio); |
| 1125 | bio = next; |
| 1126 | } |
| 1127 | } |
| 1128 | |
| 1129 | void bio_check_pages_dirty(struct bio *bio) |
| 1130 | { |
| 1131 | struct bio_vec *bvec = bio->bi_io_vec; |
| 1132 | int nr_clean_pages = 0; |
| 1133 | int i; |
| 1134 | |
| 1135 | for (i = 0; i < bio->bi_vcnt; i++) { |
| 1136 | struct page *page = bvec[i].bv_page; |
| 1137 | |
| 1138 | if (PageDirty(page) || PageCompound(page)) { |
| 1139 | page_cache_release(page); |
| 1140 | bvec[i].bv_page = NULL; |
| 1141 | } else { |
| 1142 | nr_clean_pages++; |
| 1143 | } |
| 1144 | } |
| 1145 | |
| 1146 | if (nr_clean_pages) { |
| 1147 | unsigned long flags; |
| 1148 | |
| 1149 | spin_lock_irqsave(&bio_dirty_lock, flags); |
| 1150 | bio->bi_private = bio_dirty_list; |
| 1151 | bio_dirty_list = bio; |
| 1152 | spin_unlock_irqrestore(&bio_dirty_lock, flags); |
| 1153 | schedule_work(&bio_dirty_work); |
| 1154 | } else { |
| 1155 | bio_put(bio); |
| 1156 | } |
| 1157 | } |
| 1158 | |
| 1159 | /** |
| 1160 | * bio_endio - end I/O on a bio |
| 1161 | * @bio: bio |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1162 | * @error: error, if any |
| 1163 | * |
| 1164 | * Description: |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 1165 | * 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] | 1166 | * preferred way to end I/O on a bio, it takes care of clearing |
| 1167 | * BIO_UPTODATE on error. @error is 0 on success, and and one of the |
| 1168 | * established -Exxxx (-EIO, for instance) error values in case |
| 1169 | * something went wrong. Noone should call bi_end_io() directly on a |
| 1170 | * bio unless they own it and thus know that it has an end_io |
| 1171 | * function. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1172 | **/ |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 1173 | void bio_endio(struct bio *bio, int error) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1174 | { |
| 1175 | if (error) |
| 1176 | clear_bit(BIO_UPTODATE, &bio->bi_flags); |
NeilBrown | 9cc54d4 | 2007-09-27 12:46:12 +0200 | [diff] [blame] | 1177 | else if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) |
| 1178 | error = -EIO; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1179 | |
NeilBrown | 5bb23a6 | 2007-09-27 12:46:13 +0200 | [diff] [blame] | 1180 | if (bio->bi_end_io) |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 1181 | bio->bi_end_io(bio, error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1182 | } |
| 1183 | |
| 1184 | void bio_pair_release(struct bio_pair *bp) |
| 1185 | { |
| 1186 | if (atomic_dec_and_test(&bp->cnt)) { |
| 1187 | struct bio *master = bp->bio1.bi_private; |
| 1188 | |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 1189 | bio_endio(master, bp->error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1190 | mempool_free(bp, bp->bio2.bi_private); |
| 1191 | } |
| 1192 | } |
| 1193 | |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 1194 | static void bio_pair_end_1(struct bio *bi, int err) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1195 | { |
| 1196 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio1); |
| 1197 | |
| 1198 | if (err) |
| 1199 | bp->error = err; |
| 1200 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1201 | bio_pair_release(bp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1202 | } |
| 1203 | |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 1204 | static void bio_pair_end_2(struct bio *bi, int err) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1205 | { |
| 1206 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio2); |
| 1207 | |
| 1208 | if (err) |
| 1209 | bp->error = err; |
| 1210 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1211 | bio_pair_release(bp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1212 | } |
| 1213 | |
| 1214 | /* |
| 1215 | * split a bio - only worry about a bio with a single page |
| 1216 | * in it's iovec |
| 1217 | */ |
| 1218 | struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors) |
| 1219 | { |
| 1220 | struct bio_pair *bp = mempool_alloc(pool, GFP_NOIO); |
| 1221 | |
| 1222 | if (!bp) |
| 1223 | return bp; |
| 1224 | |
Jens Axboe | 2056a78 | 2006-03-23 20:00:26 +0100 | [diff] [blame] | 1225 | blk_add_trace_pdu_int(bdev_get_queue(bi->bi_bdev), BLK_TA_SPLIT, bi, |
| 1226 | bi->bi_sector + first_sectors); |
| 1227 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1228 | BUG_ON(bi->bi_vcnt != 1); |
| 1229 | BUG_ON(bi->bi_idx != 0); |
| 1230 | atomic_set(&bp->cnt, 3); |
| 1231 | bp->error = 0; |
| 1232 | bp->bio1 = *bi; |
| 1233 | bp->bio2 = *bi; |
| 1234 | bp->bio2.bi_sector += first_sectors; |
| 1235 | bp->bio2.bi_size -= first_sectors << 9; |
| 1236 | bp->bio1.bi_size = first_sectors << 9; |
| 1237 | |
| 1238 | bp->bv1 = bi->bi_io_vec[0]; |
| 1239 | bp->bv2 = bi->bi_io_vec[0]; |
| 1240 | bp->bv2.bv_offset += first_sectors << 9; |
| 1241 | bp->bv2.bv_len -= first_sectors << 9; |
| 1242 | bp->bv1.bv_len = first_sectors << 9; |
| 1243 | |
| 1244 | bp->bio1.bi_io_vec = &bp->bv1; |
| 1245 | bp->bio2.bi_io_vec = &bp->bv2; |
| 1246 | |
NeilBrown | a2eb0c1 | 2006-05-22 22:35:27 -0700 | [diff] [blame] | 1247 | bp->bio1.bi_max_vecs = 1; |
| 1248 | bp->bio2.bi_max_vecs = 1; |
| 1249 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1250 | bp->bio1.bi_end_io = bio_pair_end_1; |
| 1251 | bp->bio2.bi_end_io = bio_pair_end_2; |
| 1252 | |
| 1253 | bp->bio1.bi_private = bi; |
| 1254 | bp->bio2.bi_private = pool; |
| 1255 | |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 1256 | if (bio_integrity(bi)) |
| 1257 | bio_integrity_split(bi, bp, first_sectors); |
| 1258 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1259 | return bp; |
| 1260 | } |
| 1261 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1262 | |
| 1263 | /* |
| 1264 | * create memory pools for biovec's in a bio_set. |
| 1265 | * use the global biovec slabs created for general use. |
| 1266 | */ |
Jens Axboe | 5972511 | 2007-04-02 10:06:42 +0200 | [diff] [blame] | 1267 | static int biovec_create_pools(struct bio_set *bs, int pool_entries) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1268 | { |
| 1269 | int i; |
| 1270 | |
| 1271 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { |
| 1272 | struct biovec_slab *bp = bvec_slabs + i; |
| 1273 | mempool_t **bvp = bs->bvec_pools + i; |
| 1274 | |
Matthew Dobson | 93d2341 | 2006-03-26 01:37:50 -0800 | [diff] [blame] | 1275 | *bvp = mempool_create_slab_pool(pool_entries, bp->slab); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1276 | if (!*bvp) |
| 1277 | return -ENOMEM; |
| 1278 | } |
| 1279 | return 0; |
| 1280 | } |
| 1281 | |
| 1282 | static void biovec_free_pools(struct bio_set *bs) |
| 1283 | { |
| 1284 | int i; |
| 1285 | |
| 1286 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { |
| 1287 | mempool_t *bvp = bs->bvec_pools[i]; |
| 1288 | |
| 1289 | if (bvp) |
| 1290 | mempool_destroy(bvp); |
| 1291 | } |
| 1292 | |
| 1293 | } |
| 1294 | |
| 1295 | void bioset_free(struct bio_set *bs) |
| 1296 | { |
| 1297 | if (bs->bio_pool) |
| 1298 | mempool_destroy(bs->bio_pool); |
| 1299 | |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 1300 | bioset_integrity_free(bs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1301 | biovec_free_pools(bs); |
| 1302 | |
| 1303 | kfree(bs); |
| 1304 | } |
| 1305 | |
Jens Axboe | 5972511 | 2007-04-02 10:06:42 +0200 | [diff] [blame] | 1306 | struct bio_set *bioset_create(int bio_pool_size, int bvec_pool_size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1307 | { |
Oliver Neukum | 11b0b5a | 2006-03-25 03:08:13 -0800 | [diff] [blame] | 1308 | struct bio_set *bs = kzalloc(sizeof(*bs), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1309 | |
| 1310 | if (!bs) |
| 1311 | return NULL; |
| 1312 | |
Matthew Dobson | 93d2341 | 2006-03-26 01:37:50 -0800 | [diff] [blame] | 1313 | bs->bio_pool = mempool_create_slab_pool(bio_pool_size, bio_slab); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1314 | if (!bs->bio_pool) |
| 1315 | goto bad; |
| 1316 | |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 1317 | if (bioset_integrity_create(bs, bio_pool_size)) |
| 1318 | goto bad; |
| 1319 | |
Jens Axboe | 5972511 | 2007-04-02 10:06:42 +0200 | [diff] [blame] | 1320 | if (!biovec_create_pools(bs, bvec_pool_size)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1321 | return bs; |
| 1322 | |
| 1323 | bad: |
| 1324 | bioset_free(bs); |
| 1325 | return NULL; |
| 1326 | } |
| 1327 | |
| 1328 | static void __init biovec_init_slabs(void) |
| 1329 | { |
| 1330 | int i; |
| 1331 | |
| 1332 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { |
| 1333 | int size; |
| 1334 | struct biovec_slab *bvs = bvec_slabs + i; |
| 1335 | |
| 1336 | size = bvs->nr_vecs * sizeof(struct bio_vec); |
| 1337 | bvs->slab = kmem_cache_create(bvs->name, size, 0, |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1338 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1339 | } |
| 1340 | } |
| 1341 | |
| 1342 | static int __init init_bio(void) |
| 1343 | { |
Christoph Lameter | 0a31bd5 | 2007-05-06 14:49:57 -0700 | [diff] [blame] | 1344 | bio_slab = KMEM_CACHE(bio, SLAB_HWCACHE_ALIGN|SLAB_PANIC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1345 | |
Martin K. Petersen | 7ba1ba1 | 2008-06-30 20:04:41 +0200 | [diff] [blame] | 1346 | bio_integrity_init_slab(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1347 | biovec_init_slabs(); |
| 1348 | |
Jens Axboe | 5972511 | 2007-04-02 10:06:42 +0200 | [diff] [blame] | 1349 | fs_bio_set = bioset_create(BIO_POOL_SIZE, 2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1350 | if (!fs_bio_set) |
| 1351 | panic("bio: can't allocate bios\n"); |
| 1352 | |
Matthew Dobson | 0eaae62a | 2006-03-26 01:37:47 -0800 | [diff] [blame] | 1353 | bio_split_pool = mempool_create_kmalloc_pool(BIO_SPLIT_ENTRIES, |
| 1354 | sizeof(struct bio_pair)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1355 | if (!bio_split_pool) |
| 1356 | panic("bio: can't create split pool\n"); |
| 1357 | |
| 1358 | return 0; |
| 1359 | } |
| 1360 | |
| 1361 | subsys_initcall(init_bio); |
| 1362 | |
| 1363 | EXPORT_SYMBOL(bio_alloc); |
| 1364 | EXPORT_SYMBOL(bio_put); |
Peter Osterlund | 3676347 | 2005-09-06 15:16:42 -0700 | [diff] [blame] | 1365 | EXPORT_SYMBOL(bio_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1366 | EXPORT_SYMBOL(bio_endio); |
| 1367 | EXPORT_SYMBOL(bio_init); |
| 1368 | EXPORT_SYMBOL(__bio_clone); |
| 1369 | EXPORT_SYMBOL(bio_clone); |
| 1370 | EXPORT_SYMBOL(bio_phys_segments); |
| 1371 | EXPORT_SYMBOL(bio_hw_segments); |
| 1372 | EXPORT_SYMBOL(bio_add_page); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 1373 | EXPORT_SYMBOL(bio_add_pc_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1374 | EXPORT_SYMBOL(bio_get_nr_vecs); |
Jens Axboe | 40044ce | 2008-03-17 21:14:40 +0100 | [diff] [blame] | 1375 | EXPORT_SYMBOL(bio_map_user); |
| 1376 | EXPORT_SYMBOL(bio_unmap_user); |
Mike Christie | df46b9a | 2005-06-20 14:04:44 +0200 | [diff] [blame] | 1377 | EXPORT_SYMBOL(bio_map_kern); |
FUJITA Tomonori | 68154e9 | 2008-04-25 12:47:50 +0200 | [diff] [blame] | 1378 | EXPORT_SYMBOL(bio_copy_kern); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1379 | EXPORT_SYMBOL(bio_pair_release); |
| 1380 | EXPORT_SYMBOL(bio_split); |
| 1381 | EXPORT_SYMBOL(bio_split_pool); |
| 1382 | EXPORT_SYMBOL(bio_copy_user); |
| 1383 | EXPORT_SYMBOL(bio_uncopy_user); |
| 1384 | EXPORT_SYMBOL(bioset_create); |
| 1385 | EXPORT_SYMBOL(bioset_free); |
| 1386 | EXPORT_SYMBOL(bio_alloc_bioset); |