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authorHeinz Mauelshagen <hjm@redhat.com>2007-05-09 05:33:00 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-09 15:30:47 -0400
commit891ce207011d3d9219f79fd5114c8594bbacc653 (patch)
tree969ca658f41ec8a9f719a44a487ae582ee278c27 /drivers/md/dm-io.c
parentc897feb3dcf3c3300849056ee82b01df7bf66d3c (diff)
dm io: prepare for new interface
Introduce struct dm_io_client to prepare for per-client mempools and bio_sets. Temporary functions bios() and io_pool() choose between the per-client structures and the global ones so the old and new interfaces can co-exist. Make error_bits optional. Signed-off-by: Heinz Mauelshagen <hjm@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Milan Broz <mbroz@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/md/dm-io.c')
-rw-r--r--drivers/md/dm-io.c61
1 files changed, 44 insertions, 17 deletions
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 4d19c45158b4..66db79208c1d 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -1,5 +1,6 @@
1/* 1/*
2 * Copyright (C) 2003 Sistina Software 2 * Copyright (C) 2003 Sistina Software
3 * Copyright (C) 2006 Red Hat GmbH
3 * 4 *
4 * This file is released under the GPL. 5 * This file is released under the GPL.
5 */ 6 */
@@ -14,11 +15,17 @@
14 15
15static struct bio_set *_bios; 16static struct bio_set *_bios;
16 17
18struct dm_io_client {
19 mempool_t *pool;
20 struct bio_set *bios;
21};
22
17/* FIXME: can we shrink this ? */ 23/* FIXME: can we shrink this ? */
18struct io { 24struct io {
19 unsigned long error; 25 unsigned long error;
20 atomic_t count; 26 atomic_t count;
21 struct task_struct *sleeper; 27 struct task_struct *sleeper;
28 struct dm_io_client *client;
22 io_notify_fn callback; 29 io_notify_fn callback;
23 void *context; 30 void *context;
24}; 31};
@@ -26,12 +33,24 @@ struct io {
26/* 33/*
27 * io contexts are only dynamically allocated for asynchronous 34 * io contexts are only dynamically allocated for asynchronous
28 * io. Since async io is likely to be the majority of io we'll 35 * io. Since async io is likely to be the majority of io we'll
29 * have the same number of io contexts as buffer heads ! (FIXME: 36 * have the same number of io contexts as bios! (FIXME: must reduce this).
30 * must reduce this).
31 */ 37 */
32static unsigned _num_ios; 38static unsigned _num_ios;
33static mempool_t *_io_pool; 39static mempool_t *_io_pool;
34 40
41/*
42 * Temporary functions to allow old and new interfaces to co-exist.
43 */
44static struct bio_set *bios(struct dm_io_client *client)
45{
46 return client ? client->bios : _bios;
47}
48
49static mempool_t *io_pool(struct dm_io_client *client)
50{
51 return client ? client->pool : _io_pool;
52}
53
35static unsigned int pages_to_ios(unsigned int pages) 54static unsigned int pages_to_ios(unsigned int pages)
36{ 55{
37 return 4 * pages; /* too many ? */ 56 return 4 * pages; /* too many ? */
@@ -118,7 +137,7 @@ static void dec_count(struct io *io, unsigned int region, int error)
118 io_notify_fn fn = io->callback; 137 io_notify_fn fn = io->callback;
119 void *context = io->context; 138 void *context = io->context;
120 139
121 mempool_free(io, _io_pool); 140 mempool_free(io, io_pool(io->client));
122 fn(r, context); 141 fn(r, context);
123 } 142 }
124 } 143 }
@@ -241,7 +260,9 @@ static void vm_dp_init(struct dpages *dp, void *data)
241 260
242static void dm_bio_destructor(struct bio *bio) 261static void dm_bio_destructor(struct bio *bio)
243{ 262{
244 bio_free(bio, _bios); 263 struct io *io = bio->bi_private;
264
265 bio_free(bio, bios(io->client));
245} 266}
246 267
247/*----------------------------------------------------------------- 268/*-----------------------------------------------------------------
@@ -264,7 +285,7 @@ static void do_region(int rw, unsigned int region, struct io_region *where,
264 * to hide it from bio_add_page(). 285 * to hide it from bio_add_page().
265 */ 286 */
266 num_bvecs = (remaining / (PAGE_SIZE >> SECTOR_SHIFT)) + 2; 287 num_bvecs = (remaining / (PAGE_SIZE >> SECTOR_SHIFT)) + 2;
267 bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, _bios); 288 bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, bios(io->client));
268 bio->bi_sector = where->sector + (where->count - remaining); 289 bio->bi_sector = where->sector + (where->count - remaining);
269 bio->bi_bdev = where->bdev; 290 bio->bi_bdev = where->bdev;
270 bio->bi_end_io = endio; 291 bio->bi_end_io = endio;
@@ -319,8 +340,9 @@ static void dispatch_io(int rw, unsigned int num_regions,
319 dec_count(io, 0, 0); 340 dec_count(io, 0, 0);
320} 341}
321 342
322static int sync_io(unsigned int num_regions, struct io_region *where, 343static int sync_io(struct dm_io_client *client, unsigned int num_regions,
323 int rw, struct dpages *dp, unsigned long *error_bits) 344 struct io_region *where, int rw, struct dpages *dp,
345 unsigned long *error_bits)
324{ 346{
325 struct io io; 347 struct io io;
326 348
@@ -332,6 +354,7 @@ static int sync_io(unsigned int num_regions, struct io_region *where,
332 io.error = 0; 354 io.error = 0;
333 atomic_set(&io.count, 1); /* see dispatch_io() */ 355 atomic_set(&io.count, 1); /* see dispatch_io() */
334 io.sleeper = current; 356 io.sleeper = current;
357 io.client = client;
335 358
336 dispatch_io(rw, num_regions, where, dp, &io, 1); 359 dispatch_io(rw, num_regions, where, dp, &io, 1);
337 360
@@ -348,12 +371,15 @@ static int sync_io(unsigned int num_regions, struct io_region *where,
348 if (atomic_read(&io.count)) 371 if (atomic_read(&io.count))
349 return -EINTR; 372 return -EINTR;
350 373
351 *error_bits = io.error; 374 if (error_bits)
375 *error_bits = io.error;
376
352 return io.error ? -EIO : 0; 377 return io.error ? -EIO : 0;
353} 378}
354 379
355static int async_io(unsigned int num_regions, struct io_region *where, int rw, 380static int async_io(struct dm_io_client *client, unsigned int num_regions,
356 struct dpages *dp, io_notify_fn fn, void *context) 381 struct io_region *where, int rw, struct dpages *dp,
382 io_notify_fn fn, void *context)
357{ 383{
358 struct io *io; 384 struct io *io;
359 385
@@ -363,10 +389,11 @@ static int async_io(unsigned int num_regions, struct io_region *where, int rw,
363 return -EIO; 389 return -EIO;
364 } 390 }
365 391
366 io = mempool_alloc(_io_pool, GFP_NOIO); 392 io = mempool_alloc(io_pool(client), GFP_NOIO);
367 io->error = 0; 393 io->error = 0;
368 atomic_set(&io->count, 1); /* see dispatch_io() */ 394 atomic_set(&io->count, 1); /* see dispatch_io() */
369 io->sleeper = NULL; 395 io->sleeper = NULL;
396 io->client = client;
370 io->callback = fn; 397 io->callback = fn;
371 io->context = context; 398 io->context = context;
372 399
@@ -380,7 +407,7 @@ int dm_io_sync(unsigned int num_regions, struct io_region *where, int rw,
380{ 407{
381 struct dpages dp; 408 struct dpages dp;
382 list_dp_init(&dp, pl, offset); 409 list_dp_init(&dp, pl, offset);
383 return sync_io(num_regions, where, rw, &dp, error_bits); 410 return sync_io(NULL, num_regions, where, rw, &dp, error_bits);
384} 411}
385 412
386int dm_io_sync_bvec(unsigned int num_regions, struct io_region *where, int rw, 413int dm_io_sync_bvec(unsigned int num_regions, struct io_region *where, int rw,
@@ -388,7 +415,7 @@ int dm_io_sync_bvec(unsigned int num_regions, struct io_region *where, int rw,
388{ 415{
389 struct dpages dp; 416 struct dpages dp;
390 bvec_dp_init(&dp, bvec); 417 bvec_dp_init(&dp, bvec);
391 return sync_io(num_regions, where, rw, &dp, error_bits); 418 return sync_io(NULL, num_regions, where, rw, &dp, error_bits);
392} 419}
393 420
394int dm_io_sync_vm(unsigned int num_regions, struct io_region *where, int rw, 421int dm_io_sync_vm(unsigned int num_regions, struct io_region *where, int rw,
@@ -396,7 +423,7 @@ int dm_io_sync_vm(unsigned int num_regions, struct io_region *where, int rw,
396{ 423{
397 struct dpages dp; 424 struct dpages dp;
398 vm_dp_init(&dp, data); 425 vm_dp_init(&dp, data);
399 return sync_io(num_regions, where, rw, &dp, error_bits); 426 return sync_io(NULL, num_regions, where, rw, &dp, error_bits);
400} 427}
401 428
402int dm_io_async(unsigned int num_regions, struct io_region *where, int rw, 429int dm_io_async(unsigned int num_regions, struct io_region *where, int rw,
@@ -405,7 +432,7 @@ int dm_io_async(unsigned int num_regions, struct io_region *where, int rw,
405{ 432{
406 struct dpages dp; 433 struct dpages dp;
407 list_dp_init(&dp, pl, offset); 434 list_dp_init(&dp, pl, offset);
408 return async_io(num_regions, where, rw, &dp, fn, context); 435 return async_io(NULL, num_regions, where, rw, &dp, fn, context);
409} 436}
410 437
411int dm_io_async_bvec(unsigned int num_regions, struct io_region *where, int rw, 438int dm_io_async_bvec(unsigned int num_regions, struct io_region *where, int rw,
@@ -413,7 +440,7 @@ int dm_io_async_bvec(unsigned int num_regions, struct io_region *where, int rw,
413{ 440{
414 struct dpages dp; 441 struct dpages dp;
415 bvec_dp_init(&dp, bvec); 442 bvec_dp_init(&dp, bvec);
416 return async_io(num_regions, where, rw, &dp, fn, context); 443 return async_io(NULL, num_regions, where, rw, &dp, fn, context);
417} 444}
418 445
419int dm_io_async_vm(unsigned int num_regions, struct io_region *where, int rw, 446int dm_io_async_vm(unsigned int num_regions, struct io_region *where, int rw,
@@ -421,7 +448,7 @@ int dm_io_async_vm(unsigned int num_regions, struct io_region *where, int rw,
421{ 448{
422 struct dpages dp; 449 struct dpages dp;
423 vm_dp_init(&dp, data); 450 vm_dp_init(&dp, data);
424 return async_io(num_regions, where, rw, &dp, fn, context); 451 return async_io(NULL, num_regions, where, rw, &dp, fn, context);
425} 452}
426 453
427EXPORT_SYMBOL(dm_io_get); 454EXPORT_SYMBOL(dm_io_get);