Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2003 Sistina Software |
Heinz Mauelshagen | 891ce20 | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 3 | * Copyright (C) 2006 Red Hat GmbH |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * |
| 5 | * This file is released under the GPL. |
| 6 | */ |
| 7 | |
Mikulas Patocka | 952b355 | 2009-12-10 23:51:57 +0000 | [diff] [blame] | 8 | #include "dm.h" |
| 9 | |
Mikulas Patocka | 586e80e | 2008-10-21 17:44:59 +0100 | [diff] [blame] | 10 | #include <linux/device-mapper.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | |
| 12 | #include <linux/bio.h> |
Joe Thornber | 10f1d5d | 2014-06-27 15:29:04 -0400 | [diff] [blame] | 13 | #include <linux/completion.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | #include <linux/mempool.h> |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/sched.h> |
| 17 | #include <linux/slab.h> |
Alasdair G Kergon | a765e20 | 2008-04-24 22:02:01 +0100 | [diff] [blame] | 18 | #include <linux/dm-io.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 20 | #define DM_MSG_PREFIX "io" |
| 21 | |
| 22 | #define DM_IO_MAX_REGIONS BITS_PER_LONG |
| 23 | |
Heinz Mauelshagen | 891ce20 | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 24 | struct dm_io_client { |
| 25 | mempool_t *pool; |
| 26 | struct bio_set *bios; |
| 27 | }; |
| 28 | |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 29 | /* |
| 30 | * Aligning 'struct io' reduces the number of bits required to store |
| 31 | * its address. Refer to store_io_and_region_in_bio() below. |
| 32 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | struct io { |
Alasdair G Kergon | e01fd7e | 2008-04-24 21:43:14 +0100 | [diff] [blame] | 34 | unsigned long error_bits; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | atomic_t count; |
Heinz Mauelshagen | 891ce20 | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 36 | struct dm_io_client *client; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | io_notify_fn callback; |
| 38 | void *context; |
Mikulas Patocka | bb91bc7 | 2011-08-02 12:32:01 +0100 | [diff] [blame] | 39 | void *vma_invalidate_address; |
| 40 | unsigned long vma_invalidate_size; |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 41 | } __attribute__((aligned(DM_IO_MAX_REGIONS))); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | |
Mikulas Patocka | 952b355 | 2009-12-10 23:51:57 +0000 | [diff] [blame] | 43 | static struct kmem_cache *_dm_io_cache; |
| 44 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | /* |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 46 | * Create a client with mempool and bioset. |
| 47 | */ |
Mikulas Patocka | bda8efe | 2011-05-29 13:03:09 +0100 | [diff] [blame] | 48 | struct dm_io_client *dm_io_client_create(void) |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 49 | { |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 50 | struct dm_io_client *client; |
Mike Snitzer | e860313 | 2013-09-12 18:06:12 -0400 | [diff] [blame] | 51 | unsigned min_ios = dm_get_reserved_bio_based_ios(); |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 52 | |
| 53 | client = kmalloc(sizeof(*client), GFP_KERNEL); |
| 54 | if (!client) |
| 55 | return ERR_PTR(-ENOMEM); |
| 56 | |
Mike Snitzer | e860313 | 2013-09-12 18:06:12 -0400 | [diff] [blame] | 57 | client->pool = mempool_create_slab_pool(min_ios, _dm_io_cache); |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 58 | if (!client->pool) |
| 59 | goto bad; |
| 60 | |
Mike Snitzer | e860313 | 2013-09-12 18:06:12 -0400 | [diff] [blame] | 61 | client->bios = bioset_create(min_ios, 0); |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 62 | if (!client->bios) |
| 63 | goto bad; |
| 64 | |
| 65 | return client; |
| 66 | |
| 67 | bad: |
| 68 | if (client->pool) |
| 69 | mempool_destroy(client->pool); |
| 70 | kfree(client); |
| 71 | return ERR_PTR(-ENOMEM); |
| 72 | } |
| 73 | EXPORT_SYMBOL(dm_io_client_create); |
| 74 | |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 75 | void dm_io_client_destroy(struct dm_io_client *client) |
| 76 | { |
| 77 | mempool_destroy(client->pool); |
| 78 | bioset_free(client->bios); |
| 79 | kfree(client); |
| 80 | } |
| 81 | EXPORT_SYMBOL(dm_io_client_destroy); |
| 82 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | /*----------------------------------------------------------------- |
| 84 | * We need to keep track of which region a bio is doing io for. |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 85 | * To avoid a memory allocation to store just 5 or 6 bits, we |
| 86 | * ensure the 'struct io' pointer is aligned so enough low bits are |
| 87 | * always zero and then combine it with the region number directly in |
| 88 | * bi_private. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | *---------------------------------------------------------------*/ |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 90 | static void store_io_and_region_in_bio(struct bio *bio, struct io *io, |
| 91 | unsigned region) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | { |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 93 | if (unlikely(!IS_ALIGNED((unsigned long)io, DM_IO_MAX_REGIONS))) { |
| 94 | DMCRIT("Unaligned struct io pointer %p", io); |
| 95 | BUG(); |
| 96 | } |
| 97 | |
| 98 | bio->bi_private = (void *)((unsigned long)io | region); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | } |
| 100 | |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 101 | static void retrieve_io_and_region_from_bio(struct bio *bio, struct io **io, |
| 102 | unsigned *region) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | { |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 104 | unsigned long val = (unsigned long)bio->bi_private; |
| 105 | |
| 106 | *io = (void *)(val & -(unsigned long)DM_IO_MAX_REGIONS); |
| 107 | *region = val & (DM_IO_MAX_REGIONS - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | } |
| 109 | |
| 110 | /*----------------------------------------------------------------- |
| 111 | * We need an io object to keep track of the number of bios that |
| 112 | * have been dispatched for a particular io. |
| 113 | *---------------------------------------------------------------*/ |
Joe Thornber | 97e7cdf | 2014-06-30 13:26:30 -0400 | [diff] [blame] | 114 | static void complete_io(struct io *io) |
| 115 | { |
| 116 | unsigned long error_bits = io->error_bits; |
| 117 | io_notify_fn fn = io->callback; |
| 118 | void *context = io->context; |
| 119 | |
| 120 | if (io->vma_invalidate_size) |
| 121 | invalidate_kernel_vmap_range(io->vma_invalidate_address, |
| 122 | io->vma_invalidate_size); |
| 123 | |
| 124 | mempool_free(io, io->client->pool); |
| 125 | fn(error_bits, context); |
| 126 | } |
| 127 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | static void dec_count(struct io *io, unsigned int region, int error) |
| 129 | { |
Tejun Heo | d87f4c1 | 2010-09-03 11:56:19 +0200 | [diff] [blame] | 130 | if (error) |
Alasdair G Kergon | e01fd7e | 2008-04-24 21:43:14 +0100 | [diff] [blame] | 131 | set_bit(region, &io->error_bits); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | |
Joe Thornber | 97e7cdf | 2014-06-30 13:26:30 -0400 | [diff] [blame] | 133 | if (atomic_dec_and_test(&io->count)) |
| 134 | complete_io(io); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | } |
| 136 | |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 137 | static void endio(struct bio *bio, int error) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | { |
Heinz Mauelshagen | c897feb | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 139 | struct io *io; |
| 140 | unsigned region; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | if (error && bio_data_dir(bio) == READ) |
| 143 | zero_fill_bio(bio); |
| 144 | |
Heinz Mauelshagen | c897feb | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 145 | /* |
| 146 | * The bio destructor in bio_put() may use the io object. |
| 147 | */ |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 148 | retrieve_io_and_region_from_bio(bio, &io, ®ion); |
Heinz Mauelshagen | c897feb | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 149 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | bio_put(bio); |
| 151 | |
Heinz Mauelshagen | c897feb | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 152 | dec_count(io, region, error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | } |
| 154 | |
| 155 | /*----------------------------------------------------------------- |
| 156 | * These little objects provide an abstraction for getting a new |
| 157 | * destination page for io. |
| 158 | *---------------------------------------------------------------*/ |
| 159 | struct dpages { |
| 160 | void (*get_page)(struct dpages *dp, |
| 161 | struct page **p, unsigned long *len, unsigned *offset); |
| 162 | void (*next_page)(struct dpages *dp); |
| 163 | |
| 164 | unsigned context_u; |
| 165 | void *context_ptr; |
Mikulas Patocka | bb91bc7 | 2011-08-02 12:32:01 +0100 | [diff] [blame] | 166 | |
| 167 | void *vma_invalidate_address; |
| 168 | unsigned long vma_invalidate_size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | }; |
| 170 | |
| 171 | /* |
| 172 | * Functions for getting the pages from a list. |
| 173 | */ |
| 174 | static void list_get_page(struct dpages *dp, |
| 175 | struct page **p, unsigned long *len, unsigned *offset) |
| 176 | { |
| 177 | unsigned o = dp->context_u; |
| 178 | struct page_list *pl = (struct page_list *) dp->context_ptr; |
| 179 | |
| 180 | *p = pl->page; |
| 181 | *len = PAGE_SIZE - o; |
| 182 | *offset = o; |
| 183 | } |
| 184 | |
| 185 | static void list_next_page(struct dpages *dp) |
| 186 | { |
| 187 | struct page_list *pl = (struct page_list *) dp->context_ptr; |
| 188 | dp->context_ptr = pl->next; |
| 189 | dp->context_u = 0; |
| 190 | } |
| 191 | |
| 192 | static void list_dp_init(struct dpages *dp, struct page_list *pl, unsigned offset) |
| 193 | { |
| 194 | dp->get_page = list_get_page; |
| 195 | dp->next_page = list_next_page; |
| 196 | dp->context_u = offset; |
| 197 | dp->context_ptr = pl; |
| 198 | } |
| 199 | |
| 200 | /* |
| 201 | * Functions for getting the pages from a bvec. |
| 202 | */ |
Mikulas Patocka | d73f990 | 2014-02-12 16:37:30 -0500 | [diff] [blame] | 203 | static void bio_get_page(struct dpages *dp, struct page **p, |
| 204 | unsigned long *len, unsigned *offset) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | { |
Mikulas Patocka | d73f990 | 2014-02-12 16:37:30 -0500 | [diff] [blame] | 206 | struct bio_vec *bvec = dp->context_ptr; |
| 207 | *p = bvec->bv_page; |
| 208 | *len = bvec->bv_len - dp->context_u; |
| 209 | *offset = bvec->bv_offset + dp->context_u; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | } |
| 211 | |
Kent Overstreet | 003b5c5 | 2013-10-11 15:45:43 -0700 | [diff] [blame] | 212 | static void bio_next_page(struct dpages *dp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | { |
Mikulas Patocka | d73f990 | 2014-02-12 16:37:30 -0500 | [diff] [blame] | 214 | struct bio_vec *bvec = dp->context_ptr; |
| 215 | dp->context_ptr = bvec + 1; |
| 216 | dp->context_u = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | } |
| 218 | |
Kent Overstreet | 003b5c5 | 2013-10-11 15:45:43 -0700 | [diff] [blame] | 219 | static void bio_dp_init(struct dpages *dp, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 220 | { |
Kent Overstreet | 003b5c5 | 2013-10-11 15:45:43 -0700 | [diff] [blame] | 221 | dp->get_page = bio_get_page; |
| 222 | dp->next_page = bio_next_page; |
Mikulas Patocka | d73f990 | 2014-02-12 16:37:30 -0500 | [diff] [blame] | 223 | dp->context_ptr = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter); |
| 224 | dp->context_u = bio->bi_iter.bi_bvec_done; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | } |
| 226 | |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 227 | /* |
| 228 | * Functions for getting the pages from a VMA. |
| 229 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | static void vm_get_page(struct dpages *dp, |
| 231 | struct page **p, unsigned long *len, unsigned *offset) |
| 232 | { |
| 233 | *p = vmalloc_to_page(dp->context_ptr); |
| 234 | *offset = dp->context_u; |
| 235 | *len = PAGE_SIZE - dp->context_u; |
| 236 | } |
| 237 | |
| 238 | static void vm_next_page(struct dpages *dp) |
| 239 | { |
| 240 | dp->context_ptr += PAGE_SIZE - dp->context_u; |
| 241 | dp->context_u = 0; |
| 242 | } |
| 243 | |
| 244 | static void vm_dp_init(struct dpages *dp, void *data) |
| 245 | { |
| 246 | dp->get_page = vm_get_page; |
| 247 | dp->next_page = vm_next_page; |
| 248 | dp->context_u = ((unsigned long) data) & (PAGE_SIZE - 1); |
| 249 | dp->context_ptr = data; |
| 250 | } |
| 251 | |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 252 | /* |
| 253 | * Functions for getting the pages from kernel memory. |
| 254 | */ |
| 255 | static void km_get_page(struct dpages *dp, struct page **p, unsigned long *len, |
| 256 | unsigned *offset) |
| 257 | { |
| 258 | *p = virt_to_page(dp->context_ptr); |
| 259 | *offset = dp->context_u; |
| 260 | *len = PAGE_SIZE - dp->context_u; |
| 261 | } |
| 262 | |
| 263 | static void km_next_page(struct dpages *dp) |
| 264 | { |
| 265 | dp->context_ptr += PAGE_SIZE - dp->context_u; |
| 266 | dp->context_u = 0; |
| 267 | } |
| 268 | |
| 269 | static void km_dp_init(struct dpages *dp, void *data) |
| 270 | { |
| 271 | dp->get_page = km_get_page; |
| 272 | dp->next_page = km_next_page; |
| 273 | dp->context_u = ((unsigned long) data) & (PAGE_SIZE - 1); |
| 274 | dp->context_ptr = data; |
| 275 | } |
| 276 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | /*----------------------------------------------------------------- |
| 278 | * IO routines that accept a list of pages. |
| 279 | *---------------------------------------------------------------*/ |
Heinz Mauelshagen | 22a1ceb | 2008-04-24 21:43:17 +0100 | [diff] [blame] | 280 | static void do_region(int rw, unsigned region, struct dm_io_region *where, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | struct dpages *dp, struct io *io) |
| 282 | { |
| 283 | struct bio *bio; |
| 284 | struct page *page; |
| 285 | unsigned long len; |
| 286 | unsigned offset; |
| 287 | unsigned num_bvecs; |
| 288 | sector_t remaining = where->count; |
Milan Broz | 0c535e0 | 2012-03-07 19:09:37 +0000 | [diff] [blame] | 289 | struct request_queue *q = bdev_get_queue(where->bdev); |
Mike Snitzer | 70d6c40 | 2012-12-21 20:23:37 +0000 | [diff] [blame] | 290 | unsigned short logical_block_size = queue_logical_block_size(q); |
| 291 | sector_t num_sectors; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | |
Mikulas Patocka | 12fc0f4 | 2009-12-10 23:52:22 +0000 | [diff] [blame] | 293 | /* |
Tejun Heo | d87f4c1 | 2010-09-03 11:56:19 +0200 | [diff] [blame] | 294 | * where->count may be zero if rw holds a flush and we need to |
| 295 | * send a zero-sized flush. |
Mikulas Patocka | 12fc0f4 | 2009-12-10 23:52:22 +0000 | [diff] [blame] | 296 | */ |
| 297 | do { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | /* |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 299 | * Allocate a suitably sized-bio. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | */ |
Mike Snitzer | 70d6c40 | 2012-12-21 20:23:37 +0000 | [diff] [blame] | 301 | if ((rw & REQ_DISCARD) || (rw & REQ_WRITE_SAME)) |
Milan Broz | 0c535e0 | 2012-03-07 19:09:37 +0000 | [diff] [blame] | 302 | num_bvecs = 1; |
| 303 | else |
| 304 | num_bvecs = min_t(int, bio_get_nr_vecs(where->bdev), |
| 305 | dm_sector_div_up(remaining, (PAGE_SIZE >> SECTOR_SHIFT))); |
| 306 | |
Milan Broz | bf17ce3 | 2007-05-09 02:33:05 -0700 | [diff] [blame] | 307 | bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, io->client->bios); |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 308 | bio->bi_iter.bi_sector = where->sector + (where->count - remaining); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | bio->bi_bdev = where->bdev; |
| 310 | bio->bi_end_io = endio; |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 311 | store_io_and_region_in_bio(bio, io, region); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | |
Milan Broz | 0c535e0 | 2012-03-07 19:09:37 +0000 | [diff] [blame] | 313 | if (rw & REQ_DISCARD) { |
Mike Snitzer | 70d6c40 | 2012-12-21 20:23:37 +0000 | [diff] [blame] | 314 | num_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining); |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 315 | bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT; |
Mike Snitzer | 70d6c40 | 2012-12-21 20:23:37 +0000 | [diff] [blame] | 316 | remaining -= num_sectors; |
| 317 | } else if (rw & REQ_WRITE_SAME) { |
| 318 | /* |
| 319 | * WRITE SAME only uses a single page. |
| 320 | */ |
| 321 | dp->get_page(dp, &page, &len, &offset); |
| 322 | bio_add_page(bio, page, logical_block_size, offset); |
| 323 | num_sectors = min_t(sector_t, q->limits.max_write_same_sectors, remaining); |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 324 | bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT; |
Mike Snitzer | 70d6c40 | 2012-12-21 20:23:37 +0000 | [diff] [blame] | 325 | |
| 326 | offset = 0; |
| 327 | remaining -= num_sectors; |
| 328 | dp->next_page(dp); |
Milan Broz | 0c535e0 | 2012-03-07 19:09:37 +0000 | [diff] [blame] | 329 | } else while (remaining) { |
| 330 | /* |
| 331 | * Try and add as many pages as possible. |
| 332 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | dp->get_page(dp, &page, &len, &offset); |
| 334 | len = min(len, to_bytes(remaining)); |
| 335 | if (!bio_add_page(bio, page, len, offset)) |
| 336 | break; |
| 337 | |
| 338 | offset = 0; |
| 339 | remaining -= to_sector(len); |
| 340 | dp->next_page(dp); |
| 341 | } |
| 342 | |
| 343 | atomic_inc(&io->count); |
| 344 | submit_bio(rw, bio); |
Mikulas Patocka | 12fc0f4 | 2009-12-10 23:52:22 +0000 | [diff] [blame] | 345 | } while (remaining); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | } |
| 347 | |
| 348 | static void dispatch_io(int rw, unsigned int num_regions, |
Heinz Mauelshagen | 22a1ceb | 2008-04-24 21:43:17 +0100 | [diff] [blame] | 349 | struct dm_io_region *where, struct dpages *dp, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | struct io *io, int sync) |
| 351 | { |
| 352 | int i; |
| 353 | struct dpages old_pages = *dp; |
| 354 | |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 355 | BUG_ON(num_regions > DM_IO_MAX_REGIONS); |
| 356 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | if (sync) |
Jens Axboe | 721a960 | 2011-03-09 11:56:30 +0100 | [diff] [blame] | 358 | rw |= REQ_SYNC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | |
| 360 | /* |
| 361 | * For multiple regions we need to be careful to rewind |
| 362 | * the dp object for each call to do_region. |
| 363 | */ |
| 364 | for (i = 0; i < num_regions; i++) { |
| 365 | *dp = old_pages; |
Tejun Heo | d87f4c1 | 2010-09-03 11:56:19 +0200 | [diff] [blame] | 366 | if (where[i].count || (rw & REQ_FLUSH)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | do_region(rw, i, where + i, dp, io); |
| 368 | } |
| 369 | |
| 370 | /* |
Heinz Mauelshagen | f00b16a | 2006-12-08 02:41:01 -0800 | [diff] [blame] | 371 | * Drop the extra reference that we were holding to avoid |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | * the io being completed too early. |
| 373 | */ |
| 374 | dec_count(io, 0, 0); |
| 375 | } |
| 376 | |
Joe Thornber | 97e7cdf | 2014-06-30 13:26:30 -0400 | [diff] [blame] | 377 | struct sync_io { |
| 378 | unsigned long error_bits; |
| 379 | struct completion wait; |
| 380 | }; |
| 381 | |
| 382 | static void sync_io_complete(unsigned long error, void *context) |
| 383 | { |
| 384 | struct sync_io *sio = context; |
| 385 | |
| 386 | sio->error_bits = error; |
| 387 | complete(&sio->wait); |
| 388 | } |
| 389 | |
Heinz Mauelshagen | 891ce20 | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 390 | static int sync_io(struct dm_io_client *client, unsigned int num_regions, |
Heinz Mauelshagen | 22a1ceb | 2008-04-24 21:43:17 +0100 | [diff] [blame] | 391 | struct dm_io_region *where, int rw, struct dpages *dp, |
Heinz Mauelshagen | 891ce20 | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 392 | unsigned long *error_bits) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 393 | { |
Joe Thornber | 97e7cdf | 2014-06-30 13:26:30 -0400 | [diff] [blame] | 394 | struct io *io; |
| 395 | struct sync_io sio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | |
Mikulas Patocka | 7ff14a3 | 2008-04-24 22:10:47 +0100 | [diff] [blame] | 397 | if (num_regions > 1 && (rw & RW_MASK) != WRITE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | WARN_ON(1); |
| 399 | return -EIO; |
| 400 | } |
| 401 | |
Joe Thornber | 97e7cdf | 2014-06-30 13:26:30 -0400 | [diff] [blame] | 402 | init_completion(&sio.wait); |
| 403 | |
| 404 | io = mempool_alloc(client->pool, GFP_NOIO); |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 405 | io->error_bits = 0; |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 406 | atomic_set(&io->count, 1); /* see dispatch_io() */ |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 407 | io->client = client; |
Joe Thornber | 97e7cdf | 2014-06-30 13:26:30 -0400 | [diff] [blame] | 408 | io->callback = sync_io_complete; |
| 409 | io->context = &sio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | |
Mikulas Patocka | bb91bc7 | 2011-08-02 12:32:01 +0100 | [diff] [blame] | 411 | io->vma_invalidate_address = dp->vma_invalidate_address; |
| 412 | io->vma_invalidate_size = dp->vma_invalidate_size; |
| 413 | |
Mikulas Patocka | f1e5398 | 2009-12-10 23:51:58 +0000 | [diff] [blame] | 414 | dispatch_io(rw, num_regions, where, dp, io, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | |
Joe Thornber | 97e7cdf | 2014-06-30 13:26:30 -0400 | [diff] [blame] | 416 | wait_for_completion_io(&sio.wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | |
Heinz Mauelshagen | 891ce20 | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 418 | if (error_bits) |
Joe Thornber | 97e7cdf | 2014-06-30 13:26:30 -0400 | [diff] [blame] | 419 | *error_bits = sio.error_bits; |
Heinz Mauelshagen | 891ce20 | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 420 | |
Joe Thornber | 97e7cdf | 2014-06-30 13:26:30 -0400 | [diff] [blame] | 421 | return sio.error_bits ? -EIO : 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 422 | } |
| 423 | |
Heinz Mauelshagen | 891ce20 | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 424 | static int async_io(struct dm_io_client *client, unsigned int num_regions, |
Heinz Mauelshagen | 22a1ceb | 2008-04-24 21:43:17 +0100 | [diff] [blame] | 425 | struct dm_io_region *where, int rw, struct dpages *dp, |
Heinz Mauelshagen | 891ce20 | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 426 | io_notify_fn fn, void *context) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | { |
| 428 | struct io *io; |
| 429 | |
Mikulas Patocka | 7ff14a3 | 2008-04-24 22:10:47 +0100 | [diff] [blame] | 430 | if (num_regions > 1 && (rw & RW_MASK) != WRITE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | WARN_ON(1); |
| 432 | fn(1, context); |
| 433 | return -EIO; |
| 434 | } |
| 435 | |
Milan Broz | bf17ce3 | 2007-05-09 02:33:05 -0700 | [diff] [blame] | 436 | io = mempool_alloc(client->pool, GFP_NOIO); |
Alasdair G Kergon | e01fd7e | 2008-04-24 21:43:14 +0100 | [diff] [blame] | 437 | io->error_bits = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | atomic_set(&io->count, 1); /* see dispatch_io() */ |
Heinz Mauelshagen | 891ce20 | 2007-05-09 02:33:00 -0700 | [diff] [blame] | 439 | io->client = client; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | io->callback = fn; |
| 441 | io->context = context; |
| 442 | |
Mikulas Patocka | bb91bc7 | 2011-08-02 12:32:01 +0100 | [diff] [blame] | 443 | io->vma_invalidate_address = dp->vma_invalidate_address; |
| 444 | io->vma_invalidate_size = dp->vma_invalidate_size; |
| 445 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | dispatch_io(rw, num_regions, where, dp, io, 0); |
| 447 | return 0; |
| 448 | } |
| 449 | |
Mikulas Patocka | bb91bc7 | 2011-08-02 12:32:01 +0100 | [diff] [blame] | 450 | static int dp_init(struct dm_io_request *io_req, struct dpages *dp, |
| 451 | unsigned long size) |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 452 | { |
| 453 | /* Set up dpages based on memory type */ |
Mikulas Patocka | bb91bc7 | 2011-08-02 12:32:01 +0100 | [diff] [blame] | 454 | |
| 455 | dp->vma_invalidate_address = NULL; |
| 456 | dp->vma_invalidate_size = 0; |
| 457 | |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 458 | switch (io_req->mem.type) { |
| 459 | case DM_IO_PAGE_LIST: |
| 460 | list_dp_init(dp, io_req->mem.ptr.pl, io_req->mem.offset); |
| 461 | break; |
| 462 | |
Kent Overstreet | 003b5c5 | 2013-10-11 15:45:43 -0700 | [diff] [blame] | 463 | case DM_IO_BIO: |
| 464 | bio_dp_init(dp, io_req->mem.ptr.bio); |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 465 | break; |
| 466 | |
| 467 | case DM_IO_VMA: |
Mikulas Patocka | bb91bc7 | 2011-08-02 12:32:01 +0100 | [diff] [blame] | 468 | flush_kernel_vmap_range(io_req->mem.ptr.vma, size); |
| 469 | if ((io_req->bi_rw & RW_MASK) == READ) { |
| 470 | dp->vma_invalidate_address = io_req->mem.ptr.vma; |
| 471 | dp->vma_invalidate_size = size; |
| 472 | } |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 473 | vm_dp_init(dp, io_req->mem.ptr.vma); |
| 474 | break; |
| 475 | |
| 476 | case DM_IO_KMEM: |
| 477 | km_dp_init(dp, io_req->mem.ptr.addr); |
| 478 | break; |
| 479 | |
| 480 | default: |
| 481 | return -EINVAL; |
| 482 | } |
| 483 | |
| 484 | return 0; |
| 485 | } |
| 486 | |
| 487 | /* |
Mikulas Patocka | 7ff14a3 | 2008-04-24 22:10:47 +0100 | [diff] [blame] | 488 | * New collapsed (a)synchronous interface. |
| 489 | * |
| 490 | * If the IO is asynchronous (i.e. it has notify.fn), you must either unplug |
Joe Thornber | 97e7cdf | 2014-06-30 13:26:30 -0400 | [diff] [blame] | 491 | * the queue with blk_unplug() some time later or set REQ_SYNC in io_req->bi_rw. |
| 492 | * If you fail to do one of these, the IO will be submitted to the disk after |
| 493 | * q->unplug_delay, which defaults to 3ms in blk-settings.c. |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 494 | */ |
| 495 | int dm_io(struct dm_io_request *io_req, unsigned num_regions, |
Heinz Mauelshagen | 22a1ceb | 2008-04-24 21:43:17 +0100 | [diff] [blame] | 496 | struct dm_io_region *where, unsigned long *sync_error_bits) |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 497 | { |
| 498 | int r; |
| 499 | struct dpages dp; |
| 500 | |
Mikulas Patocka | bb91bc7 | 2011-08-02 12:32:01 +0100 | [diff] [blame] | 501 | r = dp_init(io_req, &dp, (unsigned long)where->count << SECTOR_SHIFT); |
Heinz Mauelshagen | c8b03af | 2007-05-09 02:33:01 -0700 | [diff] [blame] | 502 | if (r) |
| 503 | return r; |
| 504 | |
| 505 | if (!io_req->notify.fn) |
| 506 | return sync_io(io_req->client, num_regions, where, |
| 507 | io_req->bi_rw, &dp, sync_error_bits); |
| 508 | |
| 509 | return async_io(io_req->client, num_regions, where, io_req->bi_rw, |
| 510 | &dp, io_req->notify.fn, io_req->notify.context); |
| 511 | } |
| 512 | EXPORT_SYMBOL(dm_io); |
Mikulas Patocka | 952b355 | 2009-12-10 23:51:57 +0000 | [diff] [blame] | 513 | |
| 514 | int __init dm_io_init(void) |
| 515 | { |
| 516 | _dm_io_cache = KMEM_CACHE(io, 0); |
| 517 | if (!_dm_io_cache) |
| 518 | return -ENOMEM; |
| 519 | |
| 520 | return 0; |
| 521 | } |
| 522 | |
| 523 | void dm_io_exit(void) |
| 524 | { |
| 525 | kmem_cache_destroy(_dm_io_cache); |
| 526 | _dm_io_cache = NULL; |
| 527 | } |