diff options
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_buf.c')
-rw-r--r-- | fs/xfs/linux-2.6/xfs_buf.c | 1980 |
1 files changed, 1980 insertions, 0 deletions
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c new file mode 100644 index 000000000000..23e0eb67fc25 --- /dev/null +++ b/fs/xfs/linux-2.6/xfs_buf.c | |||
@@ -0,0 +1,1980 @@ | |||
1 | /* | ||
2 | * Copyright (c) 2000-2004 Silicon Graphics, Inc. All Rights Reserved. | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or modify it | ||
5 | * under the terms of version 2 of the GNU General Public License as | ||
6 | * published by the Free Software Foundation. | ||
7 | * | ||
8 | * This program is distributed in the hope that it would be useful, but | ||
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | ||
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | ||
11 | * | ||
12 | * Further, this software is distributed without any warranty that it is | ||
13 | * free of the rightful claim of any third person regarding infringement | ||
14 | * or the like. Any license provided herein, whether implied or | ||
15 | * otherwise, applies only to this software file. Patent licenses, if | ||
16 | * any, provided herein do not apply to combinations of this program with | ||
17 | * other software, or any other product whatsoever. | ||
18 | * | ||
19 | * You should have received a copy of the GNU General Public License along | ||
20 | * with this program; if not, write the Free Software Foundation, Inc., 59 | ||
21 | * Temple Place - Suite 330, Boston MA 02111-1307, USA. | ||
22 | * | ||
23 | * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy, | ||
24 | * Mountain View, CA 94043, or: | ||
25 | * | ||
26 | * http://www.sgi.com | ||
27 | * | ||
28 | * For further information regarding this notice, see: | ||
29 | * | ||
30 | * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/ | ||
31 | */ | ||
32 | |||
33 | /* | ||
34 | * The xfs_buf.c code provides an abstract buffer cache model on top | ||
35 | * of the Linux page cache. Cached metadata blocks for a file system | ||
36 | * are hashed to the inode for the block device. xfs_buf.c assembles | ||
37 | * buffers (xfs_buf_t) on demand to aggregate such cached pages for I/O. | ||
38 | * | ||
39 | * Written by Steve Lord, Jim Mostek, Russell Cattelan | ||
40 | * and Rajagopal Ananthanarayanan ("ananth") at SGI. | ||
41 | * | ||
42 | */ | ||
43 | |||
44 | #include <linux/stddef.h> | ||
45 | #include <linux/errno.h> | ||
46 | #include <linux/slab.h> | ||
47 | #include <linux/pagemap.h> | ||
48 | #include <linux/init.h> | ||
49 | #include <linux/vmalloc.h> | ||
50 | #include <linux/bio.h> | ||
51 | #include <linux/sysctl.h> | ||
52 | #include <linux/proc_fs.h> | ||
53 | #include <linux/workqueue.h> | ||
54 | #include <linux/percpu.h> | ||
55 | #include <linux/blkdev.h> | ||
56 | #include <linux/hash.h> | ||
57 | |||
58 | #include "xfs_linux.h" | ||
59 | |||
60 | /* | ||
61 | * File wide globals | ||
62 | */ | ||
63 | |||
64 | STATIC kmem_cache_t *pagebuf_cache; | ||
65 | STATIC kmem_shaker_t pagebuf_shake; | ||
66 | STATIC int pagebuf_daemon_wakeup(int, unsigned int); | ||
67 | STATIC void pagebuf_delwri_queue(xfs_buf_t *, int); | ||
68 | STATIC struct workqueue_struct *pagebuf_logio_workqueue; | ||
69 | STATIC struct workqueue_struct *pagebuf_dataio_workqueue; | ||
70 | |||
71 | /* | ||
72 | * Pagebuf debugging | ||
73 | */ | ||
74 | |||
75 | #ifdef PAGEBUF_TRACE | ||
76 | void | ||
77 | pagebuf_trace( | ||
78 | xfs_buf_t *pb, | ||
79 | char *id, | ||
80 | void *data, | ||
81 | void *ra) | ||
82 | { | ||
83 | ktrace_enter(pagebuf_trace_buf, | ||
84 | pb, id, | ||
85 | (void *)(unsigned long)pb->pb_flags, | ||
86 | (void *)(unsigned long)pb->pb_hold.counter, | ||
87 | (void *)(unsigned long)pb->pb_sema.count.counter, | ||
88 | (void *)current, | ||
89 | data, ra, | ||
90 | (void *)(unsigned long)((pb->pb_file_offset>>32) & 0xffffffff), | ||
91 | (void *)(unsigned long)(pb->pb_file_offset & 0xffffffff), | ||
92 | (void *)(unsigned long)pb->pb_buffer_length, | ||
93 | NULL, NULL, NULL, NULL, NULL); | ||
94 | } | ||
95 | ktrace_t *pagebuf_trace_buf; | ||
96 | #define PAGEBUF_TRACE_SIZE 4096 | ||
97 | #define PB_TRACE(pb, id, data) \ | ||
98 | pagebuf_trace(pb, id, (void *)data, (void *)__builtin_return_address(0)) | ||
99 | #else | ||
100 | #define PB_TRACE(pb, id, data) do { } while (0) | ||
101 | #endif | ||
102 | |||
103 | #ifdef PAGEBUF_LOCK_TRACKING | ||
104 | # define PB_SET_OWNER(pb) ((pb)->pb_last_holder = current->pid) | ||
105 | # define PB_CLEAR_OWNER(pb) ((pb)->pb_last_holder = -1) | ||
106 | # define PB_GET_OWNER(pb) ((pb)->pb_last_holder) | ||
107 | #else | ||
108 | # define PB_SET_OWNER(pb) do { } while (0) | ||
109 | # define PB_CLEAR_OWNER(pb) do { } while (0) | ||
110 | # define PB_GET_OWNER(pb) do { } while (0) | ||
111 | #endif | ||
112 | |||
113 | /* | ||
114 | * Pagebuf allocation / freeing. | ||
115 | */ | ||
116 | |||
117 | #define pb_to_gfp(flags) \ | ||
118 | ((((flags) & PBF_READ_AHEAD) ? __GFP_NORETRY : \ | ||
119 | ((flags) & PBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN) | ||
120 | |||
121 | #define pb_to_km(flags) \ | ||
122 | (((flags) & PBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP) | ||
123 | |||
124 | |||
125 | #define pagebuf_allocate(flags) \ | ||
126 | kmem_zone_alloc(pagebuf_cache, pb_to_km(flags)) | ||
127 | #define pagebuf_deallocate(pb) \ | ||
128 | kmem_zone_free(pagebuf_cache, (pb)); | ||
129 | |||
130 | /* | ||
131 | * Page Region interfaces. | ||
132 | * | ||
133 | * For pages in filesystems where the blocksize is smaller than the | ||
134 | * pagesize, we use the page->private field (long) to hold a bitmap | ||
135 | * of uptodate regions within the page. | ||
136 | * | ||
137 | * Each such region is "bytes per page / bits per long" bytes long. | ||
138 | * | ||
139 | * NBPPR == number-of-bytes-per-page-region | ||
140 | * BTOPR == bytes-to-page-region (rounded up) | ||
141 | * BTOPRT == bytes-to-page-region-truncated (rounded down) | ||
142 | */ | ||
143 | #if (BITS_PER_LONG == 32) | ||
144 | #define PRSHIFT (PAGE_CACHE_SHIFT - 5) /* (32 == 1<<5) */ | ||
145 | #elif (BITS_PER_LONG == 64) | ||
146 | #define PRSHIFT (PAGE_CACHE_SHIFT - 6) /* (64 == 1<<6) */ | ||
147 | #else | ||
148 | #error BITS_PER_LONG must be 32 or 64 | ||
149 | #endif | ||
150 | #define NBPPR (PAGE_CACHE_SIZE/BITS_PER_LONG) | ||
151 | #define BTOPR(b) (((unsigned int)(b) + (NBPPR - 1)) >> PRSHIFT) | ||
152 | #define BTOPRT(b) (((unsigned int)(b) >> PRSHIFT)) | ||
153 | |||
154 | STATIC unsigned long | ||
155 | page_region_mask( | ||
156 | size_t offset, | ||
157 | size_t length) | ||
158 | { | ||
159 | unsigned long mask; | ||
160 | int first, final; | ||
161 | |||
162 | first = BTOPR(offset); | ||
163 | final = BTOPRT(offset + length - 1); | ||
164 | first = min(first, final); | ||
165 | |||
166 | mask = ~0UL; | ||
167 | mask <<= BITS_PER_LONG - (final - first); | ||
168 | mask >>= BITS_PER_LONG - (final); | ||
169 | |||
170 | ASSERT(offset + length <= PAGE_CACHE_SIZE); | ||
171 | ASSERT((final - first) < BITS_PER_LONG && (final - first) >= 0); | ||
172 | |||
173 | return mask; | ||
174 | } | ||
175 | |||
176 | STATIC inline void | ||
177 | set_page_region( | ||
178 | struct page *page, | ||
179 | size_t offset, | ||
180 | size_t length) | ||
181 | { | ||
182 | page->private |= page_region_mask(offset, length); | ||
183 | if (page->private == ~0UL) | ||
184 | SetPageUptodate(page); | ||
185 | } | ||
186 | |||
187 | STATIC inline int | ||
188 | test_page_region( | ||
189 | struct page *page, | ||
190 | size_t offset, | ||
191 | size_t length) | ||
192 | { | ||
193 | unsigned long mask = page_region_mask(offset, length); | ||
194 | |||
195 | return (mask && (page->private & mask) == mask); | ||
196 | } | ||
197 | |||
198 | /* | ||
199 | * Mapping of multi-page buffers into contiguous virtual space | ||
200 | */ | ||
201 | |||
202 | typedef struct a_list { | ||
203 | void *vm_addr; | ||
204 | struct a_list *next; | ||
205 | } a_list_t; | ||
206 | |||
207 | STATIC a_list_t *as_free_head; | ||
208 | STATIC int as_list_len; | ||
209 | STATIC DEFINE_SPINLOCK(as_lock); | ||
210 | |||
211 | /* | ||
212 | * Try to batch vunmaps because they are costly. | ||
213 | */ | ||
214 | STATIC void | ||
215 | free_address( | ||
216 | void *addr) | ||
217 | { | ||
218 | a_list_t *aentry; | ||
219 | |||
220 | aentry = kmalloc(sizeof(a_list_t), GFP_ATOMIC & ~__GFP_HIGH); | ||
221 | if (likely(aentry)) { | ||
222 | spin_lock(&as_lock); | ||
223 | aentry->next = as_free_head; | ||
224 | aentry->vm_addr = addr; | ||
225 | as_free_head = aentry; | ||
226 | as_list_len++; | ||
227 | spin_unlock(&as_lock); | ||
228 | } else { | ||
229 | vunmap(addr); | ||
230 | } | ||
231 | } | ||
232 | |||
233 | STATIC void | ||
234 | purge_addresses(void) | ||
235 | { | ||
236 | a_list_t *aentry, *old; | ||
237 | |||
238 | if (as_free_head == NULL) | ||
239 | return; | ||
240 | |||
241 | spin_lock(&as_lock); | ||
242 | aentry = as_free_head; | ||
243 | as_free_head = NULL; | ||
244 | as_list_len = 0; | ||
245 | spin_unlock(&as_lock); | ||
246 | |||
247 | while ((old = aentry) != NULL) { | ||
248 | vunmap(aentry->vm_addr); | ||
249 | aentry = aentry->next; | ||
250 | kfree(old); | ||
251 | } | ||
252 | } | ||
253 | |||
254 | /* | ||
255 | * Internal pagebuf object manipulation | ||
256 | */ | ||
257 | |||
258 | STATIC void | ||
259 | _pagebuf_initialize( | ||
260 | xfs_buf_t *pb, | ||
261 | xfs_buftarg_t *target, | ||
262 | loff_t range_base, | ||
263 | size_t range_length, | ||
264 | page_buf_flags_t flags) | ||
265 | { | ||
266 | /* | ||
267 | * We don't want certain flags to appear in pb->pb_flags. | ||
268 | */ | ||
269 | flags &= ~(PBF_LOCK|PBF_MAPPED|PBF_DONT_BLOCK|PBF_READ_AHEAD); | ||
270 | |||
271 | memset(pb, 0, sizeof(xfs_buf_t)); | ||
272 | atomic_set(&pb->pb_hold, 1); | ||
273 | init_MUTEX_LOCKED(&pb->pb_iodonesema); | ||
274 | INIT_LIST_HEAD(&pb->pb_list); | ||
275 | INIT_LIST_HEAD(&pb->pb_hash_list); | ||
276 | init_MUTEX_LOCKED(&pb->pb_sema); /* held, no waiters */ | ||
277 | PB_SET_OWNER(pb); | ||
278 | pb->pb_target = target; | ||
279 | pb->pb_file_offset = range_base; | ||
280 | /* | ||
281 | * Set buffer_length and count_desired to the same value initially. | ||
282 | * I/O routines should use count_desired, which will be the same in | ||
283 | * most cases but may be reset (e.g. XFS recovery). | ||
284 | */ | ||
285 | pb->pb_buffer_length = pb->pb_count_desired = range_length; | ||
286 | pb->pb_flags = flags | PBF_NONE; | ||
287 | pb->pb_bn = XFS_BUF_DADDR_NULL; | ||
288 | atomic_set(&pb->pb_pin_count, 0); | ||
289 | init_waitqueue_head(&pb->pb_waiters); | ||
290 | |||
291 | XFS_STATS_INC(pb_create); | ||
292 | PB_TRACE(pb, "initialize", target); | ||
293 | } | ||
294 | |||
295 | /* | ||
296 | * Allocate a page array capable of holding a specified number | ||
297 | * of pages, and point the page buf at it. | ||
298 | */ | ||
299 | STATIC int | ||
300 | _pagebuf_get_pages( | ||
301 | xfs_buf_t *pb, | ||
302 | int page_count, | ||
303 | page_buf_flags_t flags) | ||
304 | { | ||
305 | /* Make sure that we have a page list */ | ||
306 | if (pb->pb_pages == NULL) { | ||
307 | pb->pb_offset = page_buf_poff(pb->pb_file_offset); | ||
308 | pb->pb_page_count = page_count; | ||
309 | if (page_count <= PB_PAGES) { | ||
310 | pb->pb_pages = pb->pb_page_array; | ||
311 | } else { | ||
312 | pb->pb_pages = kmem_alloc(sizeof(struct page *) * | ||
313 | page_count, pb_to_km(flags)); | ||
314 | if (pb->pb_pages == NULL) | ||
315 | return -ENOMEM; | ||
316 | } | ||
317 | memset(pb->pb_pages, 0, sizeof(struct page *) * page_count); | ||
318 | } | ||
319 | return 0; | ||
320 | } | ||
321 | |||
322 | /* | ||
323 | * Frees pb_pages if it was malloced. | ||
324 | */ | ||
325 | STATIC void | ||
326 | _pagebuf_free_pages( | ||
327 | xfs_buf_t *bp) | ||
328 | { | ||
329 | if (bp->pb_pages != bp->pb_page_array) { | ||
330 | kmem_free(bp->pb_pages, | ||
331 | bp->pb_page_count * sizeof(struct page *)); | ||
332 | } | ||
333 | } | ||
334 | |||
335 | /* | ||
336 | * Releases the specified buffer. | ||
337 | * | ||
338 | * The modification state of any associated pages is left unchanged. | ||
339 | * The buffer most not be on any hash - use pagebuf_rele instead for | ||
340 | * hashed and refcounted buffers | ||
341 | */ | ||
342 | void | ||
343 | pagebuf_free( | ||
344 | xfs_buf_t *bp) | ||
345 | { | ||
346 | PB_TRACE(bp, "free", 0); | ||
347 | |||
348 | ASSERT(list_empty(&bp->pb_hash_list)); | ||
349 | |||
350 | if (bp->pb_flags & _PBF_PAGE_CACHE) { | ||
351 | uint i; | ||
352 | |||
353 | if ((bp->pb_flags & PBF_MAPPED) && (bp->pb_page_count > 1)) | ||
354 | free_address(bp->pb_addr - bp->pb_offset); | ||
355 | |||
356 | for (i = 0; i < bp->pb_page_count; i++) | ||
357 | page_cache_release(bp->pb_pages[i]); | ||
358 | _pagebuf_free_pages(bp); | ||
359 | } else if (bp->pb_flags & _PBF_KMEM_ALLOC) { | ||
360 | /* | ||
361 | * XXX(hch): bp->pb_count_desired might be incorrect (see | ||
362 | * pagebuf_associate_memory for details), but fortunately | ||
363 | * the Linux version of kmem_free ignores the len argument.. | ||
364 | */ | ||
365 | kmem_free(bp->pb_addr, bp->pb_count_desired); | ||
366 | _pagebuf_free_pages(bp); | ||
367 | } | ||
368 | |||
369 | pagebuf_deallocate(bp); | ||
370 | } | ||
371 | |||
372 | /* | ||
373 | * Finds all pages for buffer in question and builds it's page list. | ||
374 | */ | ||
375 | STATIC int | ||
376 | _pagebuf_lookup_pages( | ||
377 | xfs_buf_t *bp, | ||
378 | uint flags) | ||
379 | { | ||
380 | struct address_space *mapping = bp->pb_target->pbr_mapping; | ||
381 | size_t blocksize = bp->pb_target->pbr_bsize; | ||
382 | size_t size = bp->pb_count_desired; | ||
383 | size_t nbytes, offset; | ||
384 | int gfp_mask = pb_to_gfp(flags); | ||
385 | unsigned short page_count, i; | ||
386 | pgoff_t first; | ||
387 | loff_t end; | ||
388 | int error; | ||
389 | |||
390 | end = bp->pb_file_offset + bp->pb_buffer_length; | ||
391 | page_count = page_buf_btoc(end) - page_buf_btoct(bp->pb_file_offset); | ||
392 | |||
393 | error = _pagebuf_get_pages(bp, page_count, flags); | ||
394 | if (unlikely(error)) | ||
395 | return error; | ||
396 | bp->pb_flags |= _PBF_PAGE_CACHE; | ||
397 | |||
398 | offset = bp->pb_offset; | ||
399 | first = bp->pb_file_offset >> PAGE_CACHE_SHIFT; | ||
400 | |||
401 | for (i = 0; i < bp->pb_page_count; i++) { | ||
402 | struct page *page; | ||
403 | uint retries = 0; | ||
404 | |||
405 | retry: | ||
406 | page = find_or_create_page(mapping, first + i, gfp_mask); | ||
407 | if (unlikely(page == NULL)) { | ||
408 | if (flags & PBF_READ_AHEAD) { | ||
409 | bp->pb_page_count = i; | ||
410 | for (i = 0; i < bp->pb_page_count; i++) | ||
411 | unlock_page(bp->pb_pages[i]); | ||
412 | return -ENOMEM; | ||
413 | } | ||
414 | |||
415 | /* | ||
416 | * This could deadlock. | ||
417 | * | ||
418 | * But until all the XFS lowlevel code is revamped to | ||
419 | * handle buffer allocation failures we can't do much. | ||
420 | */ | ||
421 | if (!(++retries % 100)) | ||
422 | printk(KERN_ERR | ||
423 | "XFS: possible memory allocation " | ||
424 | "deadlock in %s (mode:0x%x)\n", | ||
425 | __FUNCTION__, gfp_mask); | ||
426 | |||
427 | XFS_STATS_INC(pb_page_retries); | ||
428 | pagebuf_daemon_wakeup(0, gfp_mask); | ||
429 | blk_congestion_wait(WRITE, HZ/50); | ||
430 | goto retry; | ||
431 | } | ||
432 | |||
433 | XFS_STATS_INC(pb_page_found); | ||
434 | |||
435 | nbytes = min_t(size_t, size, PAGE_CACHE_SIZE - offset); | ||
436 | size -= nbytes; | ||
437 | |||
438 | if (!PageUptodate(page)) { | ||
439 | page_count--; | ||
440 | if (blocksize >= PAGE_CACHE_SIZE) { | ||
441 | if (flags & PBF_READ) | ||
442 | bp->pb_locked = 1; | ||
443 | } else if (!PagePrivate(page)) { | ||
444 | if (test_page_region(page, offset, nbytes)) | ||
445 | page_count++; | ||
446 | } | ||
447 | } | ||
448 | |||
449 | bp->pb_pages[i] = page; | ||
450 | offset = 0; | ||
451 | } | ||
452 | |||
453 | if (!bp->pb_locked) { | ||
454 | for (i = 0; i < bp->pb_page_count; i++) | ||
455 | unlock_page(bp->pb_pages[i]); | ||
456 | } | ||
457 | |||
458 | if (page_count) { | ||
459 | /* if we have any uptodate pages, mark that in the buffer */ | ||
460 | bp->pb_flags &= ~PBF_NONE; | ||
461 | |||
462 | /* if some pages aren't uptodate, mark that in the buffer */ | ||
463 | if (page_count != bp->pb_page_count) | ||
464 | bp->pb_flags |= PBF_PARTIAL; | ||
465 | } | ||
466 | |||
467 | PB_TRACE(bp, "lookup_pages", (long)page_count); | ||
468 | return error; | ||
469 | } | ||
470 | |||
471 | /* | ||
472 | * Map buffer into kernel address-space if nessecary. | ||
473 | */ | ||
474 | STATIC int | ||
475 | _pagebuf_map_pages( | ||
476 | xfs_buf_t *bp, | ||
477 | uint flags) | ||
478 | { | ||
479 | /* A single page buffer is always mappable */ | ||
480 | if (bp->pb_page_count == 1) { | ||
481 | bp->pb_addr = page_address(bp->pb_pages[0]) + bp->pb_offset; | ||
482 | bp->pb_flags |= PBF_MAPPED; | ||
483 | } else if (flags & PBF_MAPPED) { | ||
484 | if (as_list_len > 64) | ||
485 | purge_addresses(); | ||
486 | bp->pb_addr = vmap(bp->pb_pages, bp->pb_page_count, | ||
487 | VM_MAP, PAGE_KERNEL); | ||
488 | if (unlikely(bp->pb_addr == NULL)) | ||
489 | return -ENOMEM; | ||
490 | bp->pb_addr += bp->pb_offset; | ||
491 | bp->pb_flags |= PBF_MAPPED; | ||
492 | } | ||
493 | |||
494 | return 0; | ||
495 | } | ||
496 | |||
497 | /* | ||
498 | * Finding and Reading Buffers | ||
499 | */ | ||
500 | |||
501 | /* | ||
502 | * _pagebuf_find | ||
503 | * | ||
504 | * Looks up, and creates if absent, a lockable buffer for | ||
505 | * a given range of an inode. The buffer is returned | ||
506 | * locked. If other overlapping buffers exist, they are | ||
507 | * released before the new buffer is created and locked, | ||
508 | * which may imply that this call will block until those buffers | ||
509 | * are unlocked. No I/O is implied by this call. | ||
510 | */ | ||
511 | xfs_buf_t * | ||
512 | _pagebuf_find( | ||
513 | xfs_buftarg_t *btp, /* block device target */ | ||
514 | loff_t ioff, /* starting offset of range */ | ||
515 | size_t isize, /* length of range */ | ||
516 | page_buf_flags_t flags, /* PBF_TRYLOCK */ | ||
517 | xfs_buf_t *new_pb)/* newly allocated buffer */ | ||
518 | { | ||
519 | loff_t range_base; | ||
520 | size_t range_length; | ||
521 | xfs_bufhash_t *hash; | ||
522 | xfs_buf_t *pb, *n; | ||
523 | |||
524 | range_base = (ioff << BBSHIFT); | ||
525 | range_length = (isize << BBSHIFT); | ||
526 | |||
527 | /* Check for IOs smaller than the sector size / not sector aligned */ | ||
528 | ASSERT(!(range_length < (1 << btp->pbr_sshift))); | ||
529 | ASSERT(!(range_base & (loff_t)btp->pbr_smask)); | ||
530 | |||
531 | hash = &btp->bt_hash[hash_long((unsigned long)ioff, btp->bt_hashshift)]; | ||
532 | |||
533 | spin_lock(&hash->bh_lock); | ||
534 | |||
535 | list_for_each_entry_safe(pb, n, &hash->bh_list, pb_hash_list) { | ||
536 | ASSERT(btp == pb->pb_target); | ||
537 | if (pb->pb_file_offset == range_base && | ||
538 | pb->pb_buffer_length == range_length) { | ||
539 | /* | ||
540 | * If we look at something bring it to the | ||
541 | * front of the list for next time. | ||
542 | */ | ||
543 | atomic_inc(&pb->pb_hold); | ||
544 | list_move(&pb->pb_hash_list, &hash->bh_list); | ||
545 | goto found; | ||
546 | } | ||
547 | } | ||
548 | |||
549 | /* No match found */ | ||
550 | if (new_pb) { | ||
551 | _pagebuf_initialize(new_pb, btp, range_base, | ||
552 | range_length, flags); | ||
553 | new_pb->pb_hash = hash; | ||
554 | list_add(&new_pb->pb_hash_list, &hash->bh_list); | ||
555 | } else { | ||
556 | XFS_STATS_INC(pb_miss_locked); | ||
557 | } | ||
558 | |||
559 | spin_unlock(&hash->bh_lock); | ||
560 | return new_pb; | ||
561 | |||
562 | found: | ||
563 | spin_unlock(&hash->bh_lock); | ||
564 | |||
565 | /* Attempt to get the semaphore without sleeping, | ||
566 | * if this does not work then we need to drop the | ||
567 | * spinlock and do a hard attempt on the semaphore. | ||
568 | */ | ||
569 | if (down_trylock(&pb->pb_sema)) { | ||
570 | if (!(flags & PBF_TRYLOCK)) { | ||
571 | /* wait for buffer ownership */ | ||
572 | PB_TRACE(pb, "get_lock", 0); | ||
573 | pagebuf_lock(pb); | ||
574 | XFS_STATS_INC(pb_get_locked_waited); | ||
575 | } else { | ||
576 | /* We asked for a trylock and failed, no need | ||
577 | * to look at file offset and length here, we | ||
578 | * know that this pagebuf at least overlaps our | ||
579 | * pagebuf and is locked, therefore our buffer | ||
580 | * either does not exist, or is this buffer | ||
581 | */ | ||
582 | |||
583 | pagebuf_rele(pb); | ||
584 | XFS_STATS_INC(pb_busy_locked); | ||
585 | return (NULL); | ||
586 | } | ||
587 | } else { | ||
588 | /* trylock worked */ | ||
589 | PB_SET_OWNER(pb); | ||
590 | } | ||
591 | |||
592 | if (pb->pb_flags & PBF_STALE) | ||
593 | pb->pb_flags &= PBF_MAPPED; | ||
594 | PB_TRACE(pb, "got_lock", 0); | ||
595 | XFS_STATS_INC(pb_get_locked); | ||
596 | return (pb); | ||
597 | } | ||
598 | |||
599 | /* | ||
600 | * xfs_buf_get_flags assembles a buffer covering the specified range. | ||
601 | * | ||
602 | * Storage in memory for all portions of the buffer will be allocated, | ||
603 | * although backing storage may not be. | ||
604 | */ | ||
605 | xfs_buf_t * | ||
606 | xfs_buf_get_flags( /* allocate a buffer */ | ||
607 | xfs_buftarg_t *target,/* target for buffer */ | ||
608 | loff_t ioff, /* starting offset of range */ | ||
609 | size_t isize, /* length of range */ | ||
610 | page_buf_flags_t flags) /* PBF_TRYLOCK */ | ||
611 | { | ||
612 | xfs_buf_t *pb, *new_pb; | ||
613 | int error = 0, i; | ||
614 | |||
615 | new_pb = pagebuf_allocate(flags); | ||
616 | if (unlikely(!new_pb)) | ||
617 | return NULL; | ||
618 | |||
619 | pb = _pagebuf_find(target, ioff, isize, flags, new_pb); | ||
620 | if (pb == new_pb) { | ||
621 | error = _pagebuf_lookup_pages(pb, flags); | ||
622 | if (error) | ||
623 | goto no_buffer; | ||
624 | } else { | ||
625 | pagebuf_deallocate(new_pb); | ||
626 | if (unlikely(pb == NULL)) | ||
627 | return NULL; | ||
628 | } | ||
629 | |||
630 | for (i = 0; i < pb->pb_page_count; i++) | ||
631 | mark_page_accessed(pb->pb_pages[i]); | ||
632 | |||
633 | if (!(pb->pb_flags & PBF_MAPPED)) { | ||
634 | error = _pagebuf_map_pages(pb, flags); | ||
635 | if (unlikely(error)) { | ||
636 | printk(KERN_WARNING "%s: failed to map pages\n", | ||
637 | __FUNCTION__); | ||
638 | goto no_buffer; | ||
639 | } | ||
640 | } | ||
641 | |||
642 | XFS_STATS_INC(pb_get); | ||
643 | |||
644 | /* | ||
645 | * Always fill in the block number now, the mapped cases can do | ||
646 | * their own overlay of this later. | ||
647 | */ | ||
648 | pb->pb_bn = ioff; | ||
649 | pb->pb_count_desired = pb->pb_buffer_length; | ||
650 | |||
651 | PB_TRACE(pb, "get", (unsigned long)flags); | ||
652 | return pb; | ||
653 | |||
654 | no_buffer: | ||
655 | if (flags & (PBF_LOCK | PBF_TRYLOCK)) | ||
656 | pagebuf_unlock(pb); | ||
657 | pagebuf_rele(pb); | ||
658 | return NULL; | ||
659 | } | ||
660 | |||
661 | xfs_buf_t * | ||
662 | xfs_buf_read_flags( | ||
663 | xfs_buftarg_t *target, | ||
664 | loff_t ioff, | ||
665 | size_t isize, | ||
666 | page_buf_flags_t flags) | ||
667 | { | ||
668 | xfs_buf_t *pb; | ||
669 | |||
670 | flags |= PBF_READ; | ||
671 | |||
672 | pb = xfs_buf_get_flags(target, ioff, isize, flags); | ||
673 | if (pb) { | ||
674 | if (PBF_NOT_DONE(pb)) { | ||
675 | PB_TRACE(pb, "read", (unsigned long)flags); | ||
676 | XFS_STATS_INC(pb_get_read); | ||
677 | pagebuf_iostart(pb, flags); | ||
678 | } else if (flags & PBF_ASYNC) { | ||
679 | PB_TRACE(pb, "read_async", (unsigned long)flags); | ||
680 | /* | ||
681 | * Read ahead call which is already satisfied, | ||
682 | * drop the buffer | ||
683 | */ | ||
684 | goto no_buffer; | ||
685 | } else { | ||
686 | PB_TRACE(pb, "read_done", (unsigned long)flags); | ||
687 | /* We do not want read in the flags */ | ||
688 | pb->pb_flags &= ~PBF_READ; | ||
689 | } | ||
690 | } | ||
691 | |||
692 | return pb; | ||
693 | |||
694 | no_buffer: | ||
695 | if (flags & (PBF_LOCK | PBF_TRYLOCK)) | ||
696 | pagebuf_unlock(pb); | ||
697 | pagebuf_rele(pb); | ||
698 | return NULL; | ||
699 | } | ||
700 | |||
701 | /* | ||
702 | * Create a skeletal pagebuf (no pages associated with it). | ||
703 | */ | ||
704 | xfs_buf_t * | ||
705 | pagebuf_lookup( | ||
706 | xfs_buftarg_t *target, | ||
707 | loff_t ioff, | ||
708 | size_t isize, | ||
709 | page_buf_flags_t flags) | ||
710 | { | ||
711 | xfs_buf_t *pb; | ||
712 | |||
713 | pb = pagebuf_allocate(flags); | ||
714 | if (pb) { | ||
715 | _pagebuf_initialize(pb, target, ioff, isize, flags); | ||
716 | } | ||
717 | return pb; | ||
718 | } | ||
719 | |||
720 | /* | ||
721 | * If we are not low on memory then do the readahead in a deadlock | ||
722 | * safe manner. | ||
723 | */ | ||
724 | void | ||
725 | pagebuf_readahead( | ||
726 | xfs_buftarg_t *target, | ||
727 | loff_t ioff, | ||
728 | size_t isize, | ||
729 | page_buf_flags_t flags) | ||
730 | { | ||
731 | struct backing_dev_info *bdi; | ||
732 | |||
733 | bdi = target->pbr_mapping->backing_dev_info; | ||
734 | if (bdi_read_congested(bdi)) | ||
735 | return; | ||
736 | |||
737 | flags |= (PBF_TRYLOCK|PBF_ASYNC|PBF_READ_AHEAD); | ||
738 | xfs_buf_read_flags(target, ioff, isize, flags); | ||
739 | } | ||
740 | |||
741 | xfs_buf_t * | ||
742 | pagebuf_get_empty( | ||
743 | size_t len, | ||
744 | xfs_buftarg_t *target) | ||
745 | { | ||
746 | xfs_buf_t *pb; | ||
747 | |||
748 | pb = pagebuf_allocate(0); | ||
749 | if (pb) | ||
750 | _pagebuf_initialize(pb, target, 0, len, 0); | ||
751 | return pb; | ||
752 | } | ||
753 | |||
754 | static inline struct page * | ||
755 | mem_to_page( | ||
756 | void *addr) | ||
757 | { | ||
758 | if (((unsigned long)addr < VMALLOC_START) || | ||
759 | ((unsigned long)addr >= VMALLOC_END)) { | ||
760 | return virt_to_page(addr); | ||
761 | } else { | ||
762 | return vmalloc_to_page(addr); | ||
763 | } | ||
764 | } | ||
765 | |||
766 | int | ||
767 | pagebuf_associate_memory( | ||
768 | xfs_buf_t *pb, | ||
769 | void *mem, | ||
770 | size_t len) | ||
771 | { | ||
772 | int rval; | ||
773 | int i = 0; | ||
774 | size_t ptr; | ||
775 | size_t end, end_cur; | ||
776 | off_t offset; | ||
777 | int page_count; | ||
778 | |||
779 | page_count = PAGE_CACHE_ALIGN(len) >> PAGE_CACHE_SHIFT; | ||
780 | offset = (off_t) mem - ((off_t)mem & PAGE_CACHE_MASK); | ||
781 | if (offset && (len > PAGE_CACHE_SIZE)) | ||
782 | page_count++; | ||
783 | |||
784 | /* Free any previous set of page pointers */ | ||
785 | if (pb->pb_pages) | ||
786 | _pagebuf_free_pages(pb); | ||
787 | |||
788 | pb->pb_pages = NULL; | ||
789 | pb->pb_addr = mem; | ||
790 | |||
791 | rval = _pagebuf_get_pages(pb, page_count, 0); | ||
792 | if (rval) | ||
793 | return rval; | ||
794 | |||
795 | pb->pb_offset = offset; | ||
796 | ptr = (size_t) mem & PAGE_CACHE_MASK; | ||
797 | end = PAGE_CACHE_ALIGN((size_t) mem + len); | ||
798 | end_cur = end; | ||
799 | /* set up first page */ | ||
800 | pb->pb_pages[0] = mem_to_page(mem); | ||
801 | |||
802 | ptr += PAGE_CACHE_SIZE; | ||
803 | pb->pb_page_count = ++i; | ||
804 | while (ptr < end) { | ||
805 | pb->pb_pages[i] = mem_to_page((void *)ptr); | ||
806 | pb->pb_page_count = ++i; | ||
807 | ptr += PAGE_CACHE_SIZE; | ||
808 | } | ||
809 | pb->pb_locked = 0; | ||
810 | |||
811 | pb->pb_count_desired = pb->pb_buffer_length = len; | ||
812 | pb->pb_flags |= PBF_MAPPED; | ||
813 | |||
814 | return 0; | ||
815 | } | ||
816 | |||
817 | xfs_buf_t * | ||
818 | pagebuf_get_no_daddr( | ||
819 | size_t len, | ||
820 | xfs_buftarg_t *target) | ||
821 | { | ||
822 | size_t malloc_len = len; | ||
823 | xfs_buf_t *bp; | ||
824 | void *data; | ||
825 | int error; | ||
826 | |||
827 | bp = pagebuf_allocate(0); | ||
828 | if (unlikely(bp == NULL)) | ||
829 | goto fail; | ||
830 | _pagebuf_initialize(bp, target, 0, len, PBF_FORCEIO); | ||
831 | |||
832 | try_again: | ||
833 | data = kmem_alloc(malloc_len, KM_SLEEP | KM_MAYFAIL); | ||
834 | if (unlikely(data == NULL)) | ||
835 | goto fail_free_buf; | ||
836 | |||
837 | /* check whether alignment matches.. */ | ||
838 | if ((__psunsigned_t)data != | ||
839 | ((__psunsigned_t)data & ~target->pbr_smask)) { | ||
840 | /* .. else double the size and try again */ | ||
841 | kmem_free(data, malloc_len); | ||
842 | malloc_len <<= 1; | ||
843 | goto try_again; | ||
844 | } | ||
845 | |||
846 | error = pagebuf_associate_memory(bp, data, len); | ||
847 | if (error) | ||
848 | goto fail_free_mem; | ||
849 | bp->pb_flags |= _PBF_KMEM_ALLOC; | ||
850 | |||
851 | pagebuf_unlock(bp); | ||
852 | |||
853 | PB_TRACE(bp, "no_daddr", data); | ||
854 | return bp; | ||
855 | fail_free_mem: | ||
856 | kmem_free(data, malloc_len); | ||
857 | fail_free_buf: | ||
858 | pagebuf_free(bp); | ||
859 | fail: | ||
860 | return NULL; | ||
861 | } | ||
862 | |||
863 | /* | ||
864 | * pagebuf_hold | ||
865 | * | ||
866 | * Increment reference count on buffer, to hold the buffer concurrently | ||
867 | * with another thread which may release (free) the buffer asynchronously. | ||
868 | * | ||
869 | * Must hold the buffer already to call this function. | ||
870 | */ | ||
871 | void | ||
872 | pagebuf_hold( | ||
873 | xfs_buf_t *pb) | ||
874 | { | ||
875 | atomic_inc(&pb->pb_hold); | ||
876 | PB_TRACE(pb, "hold", 0); | ||
877 | } | ||
878 | |||
879 | /* | ||
880 | * pagebuf_rele | ||
881 | * | ||
882 | * pagebuf_rele releases a hold on the specified buffer. If the | ||
883 | * the hold count is 1, pagebuf_rele calls pagebuf_free. | ||
884 | */ | ||
885 | void | ||
886 | pagebuf_rele( | ||
887 | xfs_buf_t *pb) | ||
888 | { | ||
889 | xfs_bufhash_t *hash = pb->pb_hash; | ||
890 | |||
891 | PB_TRACE(pb, "rele", pb->pb_relse); | ||
892 | |||
893 | /* | ||
894 | * pagebuf_lookup buffers are not hashed, not delayed write, | ||
895 | * and don't have their own release routines. Special case. | ||
896 | */ | ||
897 | if (unlikely(!hash)) { | ||
898 | ASSERT(!pb->pb_relse); | ||
899 | if (atomic_dec_and_test(&pb->pb_hold)) | ||
900 | xfs_buf_free(pb); | ||
901 | return; | ||
902 | } | ||
903 | |||
904 | if (atomic_dec_and_lock(&pb->pb_hold, &hash->bh_lock)) { | ||
905 | int do_free = 1; | ||
906 | |||
907 | if (pb->pb_relse) { | ||
908 | atomic_inc(&pb->pb_hold); | ||
909 | spin_unlock(&hash->bh_lock); | ||
910 | (*(pb->pb_relse)) (pb); | ||
911 | spin_lock(&hash->bh_lock); | ||
912 | do_free = 0; | ||
913 | } | ||
914 | |||
915 | if (pb->pb_flags & PBF_DELWRI) { | ||
916 | pb->pb_flags |= PBF_ASYNC; | ||
917 | atomic_inc(&pb->pb_hold); | ||
918 | pagebuf_delwri_queue(pb, 0); | ||
919 | do_free = 0; | ||
920 | } else if (pb->pb_flags & PBF_FS_MANAGED) { | ||
921 | do_free = 0; | ||
922 | } | ||
923 | |||
924 | if (do_free) { | ||
925 | list_del_init(&pb->pb_hash_list); | ||
926 | spin_unlock(&hash->bh_lock); | ||
927 | pagebuf_free(pb); | ||
928 | } else { | ||
929 | spin_unlock(&hash->bh_lock); | ||
930 | } | ||
931 | } | ||
932 | } | ||
933 | |||
934 | |||
935 | /* | ||
936 | * Mutual exclusion on buffers. Locking model: | ||
937 | * | ||
938 | * Buffers associated with inodes for which buffer locking | ||
939 | * is not enabled are not protected by semaphores, and are | ||
940 | * assumed to be exclusively owned by the caller. There is a | ||
941 | * spinlock in the buffer, used by the caller when concurrent | ||
942 | * access is possible. | ||
943 | */ | ||
944 | |||
945 | /* | ||
946 | * pagebuf_cond_lock | ||
947 | * | ||
948 | * pagebuf_cond_lock locks a buffer object, if it is not already locked. | ||
949 | * Note that this in no way | ||
950 | * locks the underlying pages, so it is only useful for synchronizing | ||
951 | * concurrent use of page buffer objects, not for synchronizing independent | ||
952 | * access to the underlying pages. | ||
953 | */ | ||
954 | int | ||
955 | pagebuf_cond_lock( /* lock buffer, if not locked */ | ||
956 | /* returns -EBUSY if locked) */ | ||
957 | xfs_buf_t *pb) | ||
958 | { | ||
959 | int locked; | ||
960 | |||
961 | locked = down_trylock(&pb->pb_sema) == 0; | ||
962 | if (locked) { | ||
963 | PB_SET_OWNER(pb); | ||
964 | } | ||
965 | PB_TRACE(pb, "cond_lock", (long)locked); | ||
966 | return(locked ? 0 : -EBUSY); | ||
967 | } | ||
968 | |||
969 | #if defined(DEBUG) || defined(XFS_BLI_TRACE) | ||
970 | /* | ||
971 | * pagebuf_lock_value | ||
972 | * | ||
973 | * Return lock value for a pagebuf | ||
974 | */ | ||
975 | int | ||
976 | pagebuf_lock_value( | ||
977 | xfs_buf_t *pb) | ||
978 | { | ||
979 | return(atomic_read(&pb->pb_sema.count)); | ||
980 | } | ||
981 | #endif | ||
982 | |||
983 | /* | ||
984 | * pagebuf_lock | ||
985 | * | ||
986 | * pagebuf_lock locks a buffer object. Note that this in no way | ||
987 | * locks the underlying pages, so it is only useful for synchronizing | ||
988 | * concurrent use of page buffer objects, not for synchronizing independent | ||
989 | * access to the underlying pages. | ||
990 | */ | ||
991 | int | ||
992 | pagebuf_lock( | ||
993 | xfs_buf_t *pb) | ||
994 | { | ||
995 | PB_TRACE(pb, "lock", 0); | ||
996 | if (atomic_read(&pb->pb_io_remaining)) | ||
997 | blk_run_address_space(pb->pb_target->pbr_mapping); | ||
998 | down(&pb->pb_sema); | ||
999 | PB_SET_OWNER(pb); | ||
1000 | PB_TRACE(pb, "locked", 0); | ||
1001 | return 0; | ||
1002 | } | ||
1003 | |||
1004 | /* | ||
1005 | * pagebuf_unlock | ||
1006 | * | ||
1007 | * pagebuf_unlock releases the lock on the buffer object created by | ||
1008 | * pagebuf_lock or pagebuf_cond_lock (not any | ||
1009 | * pinning of underlying pages created by pagebuf_pin). | ||
1010 | */ | ||
1011 | void | ||
1012 | pagebuf_unlock( /* unlock buffer */ | ||
1013 | xfs_buf_t *pb) /* buffer to unlock */ | ||
1014 | { | ||
1015 | PB_CLEAR_OWNER(pb); | ||
1016 | up(&pb->pb_sema); | ||
1017 | PB_TRACE(pb, "unlock", 0); | ||
1018 | } | ||
1019 | |||
1020 | |||
1021 | /* | ||
1022 | * Pinning Buffer Storage in Memory | ||
1023 | */ | ||
1024 | |||
1025 | /* | ||
1026 | * pagebuf_pin | ||
1027 | * | ||
1028 | * pagebuf_pin locks all of the memory represented by a buffer in | ||
1029 | * memory. Multiple calls to pagebuf_pin and pagebuf_unpin, for | ||
1030 | * the same or different buffers affecting a given page, will | ||
1031 | * properly count the number of outstanding "pin" requests. The | ||
1032 | * buffer may be released after the pagebuf_pin and a different | ||
1033 | * buffer used when calling pagebuf_unpin, if desired. | ||
1034 | * pagebuf_pin should be used by the file system when it wants be | ||
1035 | * assured that no attempt will be made to force the affected | ||
1036 | * memory to disk. It does not assure that a given logical page | ||
1037 | * will not be moved to a different physical page. | ||
1038 | */ | ||
1039 | void | ||
1040 | pagebuf_pin( | ||
1041 | xfs_buf_t *pb) | ||
1042 | { | ||
1043 | atomic_inc(&pb->pb_pin_count); | ||
1044 | PB_TRACE(pb, "pin", (long)pb->pb_pin_count.counter); | ||
1045 | } | ||
1046 | |||
1047 | /* | ||
1048 | * pagebuf_unpin | ||
1049 | * | ||
1050 | * pagebuf_unpin reverses the locking of memory performed by | ||
1051 | * pagebuf_pin. Note that both functions affected the logical | ||
1052 | * pages associated with the buffer, not the buffer itself. | ||
1053 | */ | ||
1054 | void | ||
1055 | pagebuf_unpin( | ||
1056 | xfs_buf_t *pb) | ||
1057 | { | ||
1058 | if (atomic_dec_and_test(&pb->pb_pin_count)) { | ||
1059 | wake_up_all(&pb->pb_waiters); | ||
1060 | } | ||
1061 | PB_TRACE(pb, "unpin", (long)pb->pb_pin_count.counter); | ||
1062 | } | ||
1063 | |||
1064 | int | ||
1065 | pagebuf_ispin( | ||
1066 | xfs_buf_t *pb) | ||
1067 | { | ||
1068 | return atomic_read(&pb->pb_pin_count); | ||
1069 | } | ||
1070 | |||
1071 | /* | ||
1072 | * pagebuf_wait_unpin | ||
1073 | * | ||
1074 | * pagebuf_wait_unpin waits until all of the memory associated | ||
1075 | * with the buffer is not longer locked in memory. It returns | ||
1076 | * immediately if none of the affected pages are locked. | ||
1077 | */ | ||
1078 | static inline void | ||
1079 | _pagebuf_wait_unpin( | ||
1080 | xfs_buf_t *pb) | ||
1081 | { | ||
1082 | DECLARE_WAITQUEUE (wait, current); | ||
1083 | |||
1084 | if (atomic_read(&pb->pb_pin_count) == 0) | ||
1085 | return; | ||
1086 | |||
1087 | add_wait_queue(&pb->pb_waiters, &wait); | ||
1088 | for (;;) { | ||
1089 | set_current_state(TASK_UNINTERRUPTIBLE); | ||
1090 | if (atomic_read(&pb->pb_pin_count) == 0) | ||
1091 | break; | ||
1092 | if (atomic_read(&pb->pb_io_remaining)) | ||
1093 | blk_run_address_space(pb->pb_target->pbr_mapping); | ||
1094 | schedule(); | ||
1095 | } | ||
1096 | remove_wait_queue(&pb->pb_waiters, &wait); | ||
1097 | set_current_state(TASK_RUNNING); | ||
1098 | } | ||
1099 | |||
1100 | /* | ||
1101 | * Buffer Utility Routines | ||
1102 | */ | ||
1103 | |||
1104 | /* | ||
1105 | * pagebuf_iodone | ||
1106 | * | ||
1107 | * pagebuf_iodone marks a buffer for which I/O is in progress | ||
1108 | * done with respect to that I/O. The pb_iodone routine, if | ||
1109 | * present, will be called as a side-effect. | ||
1110 | */ | ||
1111 | STATIC void | ||
1112 | pagebuf_iodone_work( | ||
1113 | void *v) | ||
1114 | { | ||
1115 | xfs_buf_t *bp = (xfs_buf_t *)v; | ||
1116 | |||
1117 | if (bp->pb_iodone) | ||
1118 | (*(bp->pb_iodone))(bp); | ||
1119 | else if (bp->pb_flags & PBF_ASYNC) | ||
1120 | xfs_buf_relse(bp); | ||
1121 | } | ||
1122 | |||
1123 | void | ||
1124 | pagebuf_iodone( | ||
1125 | xfs_buf_t *pb, | ||
1126 | int dataio, | ||
1127 | int schedule) | ||
1128 | { | ||
1129 | pb->pb_flags &= ~(PBF_READ | PBF_WRITE); | ||
1130 | if (pb->pb_error == 0) { | ||
1131 | pb->pb_flags &= ~(PBF_PARTIAL | PBF_NONE); | ||
1132 | } | ||
1133 | |||
1134 | PB_TRACE(pb, "iodone", pb->pb_iodone); | ||
1135 | |||
1136 | if ((pb->pb_iodone) || (pb->pb_flags & PBF_ASYNC)) { | ||
1137 | if (schedule) { | ||
1138 | INIT_WORK(&pb->pb_iodone_work, pagebuf_iodone_work, pb); | ||
1139 | queue_work(dataio ? pagebuf_dataio_workqueue : | ||
1140 | pagebuf_logio_workqueue, &pb->pb_iodone_work); | ||
1141 | } else { | ||
1142 | pagebuf_iodone_work(pb); | ||
1143 | } | ||
1144 | } else { | ||
1145 | up(&pb->pb_iodonesema); | ||
1146 | } | ||
1147 | } | ||
1148 | |||
1149 | /* | ||
1150 | * pagebuf_ioerror | ||
1151 | * | ||
1152 | * pagebuf_ioerror sets the error code for a buffer. | ||
1153 | */ | ||
1154 | void | ||
1155 | pagebuf_ioerror( /* mark/clear buffer error flag */ | ||
1156 | xfs_buf_t *pb, /* buffer to mark */ | ||
1157 | int error) /* error to store (0 if none) */ | ||
1158 | { | ||
1159 | ASSERT(error >= 0 && error <= 0xffff); | ||
1160 | pb->pb_error = (unsigned short)error; | ||
1161 | PB_TRACE(pb, "ioerror", (unsigned long)error); | ||
1162 | } | ||
1163 | |||
1164 | /* | ||
1165 | * pagebuf_iostart | ||
1166 | * | ||
1167 | * pagebuf_iostart initiates I/O on a buffer, based on the flags supplied. | ||
1168 | * If necessary, it will arrange for any disk space allocation required, | ||
1169 | * and it will break up the request if the block mappings require it. | ||
1170 | * The pb_iodone routine in the buffer supplied will only be called | ||
1171 | * when all of the subsidiary I/O requests, if any, have been completed. | ||
1172 | * pagebuf_iostart calls the pagebuf_ioinitiate routine or | ||
1173 | * pagebuf_iorequest, if the former routine is not defined, to start | ||
1174 | * the I/O on a given low-level request. | ||
1175 | */ | ||
1176 | int | ||
1177 | pagebuf_iostart( /* start I/O on a buffer */ | ||
1178 | xfs_buf_t *pb, /* buffer to start */ | ||
1179 | page_buf_flags_t flags) /* PBF_LOCK, PBF_ASYNC, PBF_READ, */ | ||
1180 | /* PBF_WRITE, PBF_DELWRI, */ | ||
1181 | /* PBF_DONT_BLOCK */ | ||
1182 | { | ||
1183 | int status = 0; | ||
1184 | |||
1185 | PB_TRACE(pb, "iostart", (unsigned long)flags); | ||
1186 | |||
1187 | if (flags & PBF_DELWRI) { | ||
1188 | pb->pb_flags &= ~(PBF_READ | PBF_WRITE | PBF_ASYNC); | ||
1189 | pb->pb_flags |= flags & (PBF_DELWRI | PBF_ASYNC); | ||
1190 | pagebuf_delwri_queue(pb, 1); | ||
1191 | return status; | ||
1192 | } | ||
1193 | |||
1194 | pb->pb_flags &= ~(PBF_READ | PBF_WRITE | PBF_ASYNC | PBF_DELWRI | \ | ||
1195 | PBF_READ_AHEAD | _PBF_RUN_QUEUES); | ||
1196 | pb->pb_flags |= flags & (PBF_READ | PBF_WRITE | PBF_ASYNC | \ | ||
1197 | PBF_READ_AHEAD | _PBF_RUN_QUEUES); | ||
1198 | |||
1199 | BUG_ON(pb->pb_bn == XFS_BUF_DADDR_NULL); | ||
1200 | |||
1201 | /* For writes allow an alternate strategy routine to precede | ||
1202 | * the actual I/O request (which may not be issued at all in | ||
1203 | * a shutdown situation, for example). | ||
1204 | */ | ||
1205 | status = (flags & PBF_WRITE) ? | ||
1206 | pagebuf_iostrategy(pb) : pagebuf_iorequest(pb); | ||
1207 | |||
1208 | /* Wait for I/O if we are not an async request. | ||
1209 | * Note: async I/O request completion will release the buffer, | ||
1210 | * and that can already be done by this point. So using the | ||
1211 | * buffer pointer from here on, after async I/O, is invalid. | ||
1212 | */ | ||
1213 | if (!status && !(flags & PBF_ASYNC)) | ||
1214 | status = pagebuf_iowait(pb); | ||
1215 | |||
1216 | return status; | ||
1217 | } | ||
1218 | |||
1219 | /* | ||
1220 | * Helper routine for pagebuf_iorequest | ||
1221 | */ | ||
1222 | |||
1223 | STATIC __inline__ int | ||
1224 | _pagebuf_iolocked( | ||
1225 | xfs_buf_t *pb) | ||
1226 | { | ||
1227 | ASSERT(pb->pb_flags & (PBF_READ|PBF_WRITE)); | ||
1228 | if (pb->pb_flags & PBF_READ) | ||
1229 | return pb->pb_locked; | ||
1230 | return 0; | ||
1231 | } | ||
1232 | |||
1233 | STATIC __inline__ void | ||
1234 | _pagebuf_iodone( | ||
1235 | xfs_buf_t *pb, | ||
1236 | int schedule) | ||
1237 | { | ||
1238 | if (atomic_dec_and_test(&pb->pb_io_remaining) == 1) { | ||
1239 | pb->pb_locked = 0; | ||
1240 | pagebuf_iodone(pb, (pb->pb_flags & PBF_FS_DATAIOD), schedule); | ||
1241 | } | ||
1242 | } | ||
1243 | |||
1244 | STATIC int | ||
1245 | bio_end_io_pagebuf( | ||
1246 | struct bio *bio, | ||
1247 | unsigned int bytes_done, | ||
1248 | int error) | ||
1249 | { | ||
1250 | xfs_buf_t *pb = (xfs_buf_t *)bio->bi_private; | ||
1251 | unsigned int i, blocksize = pb->pb_target->pbr_bsize; | ||
1252 | struct bio_vec *bvec = bio->bi_io_vec; | ||
1253 | |||
1254 | if (bio->bi_size) | ||
1255 | return 1; | ||
1256 | |||
1257 | if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) | ||
1258 | pb->pb_error = EIO; | ||
1259 | |||
1260 | for (i = 0; i < bio->bi_vcnt; i++, bvec++) { | ||
1261 | struct page *page = bvec->bv_page; | ||
1262 | |||
1263 | if (pb->pb_error) { | ||
1264 | SetPageError(page); | ||
1265 | } else if (blocksize == PAGE_CACHE_SIZE) { | ||
1266 | SetPageUptodate(page); | ||
1267 | } else if (!PagePrivate(page) && | ||
1268 | (pb->pb_flags & _PBF_PAGE_CACHE)) { | ||
1269 | set_page_region(page, bvec->bv_offset, bvec->bv_len); | ||
1270 | } | ||
1271 | |||
1272 | if (_pagebuf_iolocked(pb)) { | ||
1273 | unlock_page(page); | ||
1274 | } | ||
1275 | } | ||
1276 | |||
1277 | _pagebuf_iodone(pb, 1); | ||
1278 | bio_put(bio); | ||
1279 | return 0; | ||
1280 | } | ||
1281 | |||
1282 | STATIC void | ||
1283 | _pagebuf_ioapply( | ||
1284 | xfs_buf_t *pb) | ||
1285 | { | ||
1286 | int i, rw, map_i, total_nr_pages, nr_pages; | ||
1287 | struct bio *bio; | ||
1288 | int offset = pb->pb_offset; | ||
1289 | int size = pb->pb_count_desired; | ||
1290 | sector_t sector = pb->pb_bn; | ||
1291 | unsigned int blocksize = pb->pb_target->pbr_bsize; | ||
1292 | int locking = _pagebuf_iolocked(pb); | ||
1293 | |||
1294 | total_nr_pages = pb->pb_page_count; | ||
1295 | map_i = 0; | ||
1296 | |||
1297 | if (pb->pb_flags & _PBF_RUN_QUEUES) { | ||
1298 | pb->pb_flags &= ~_PBF_RUN_QUEUES; | ||
1299 | rw = (pb->pb_flags & PBF_READ) ? READ_SYNC : WRITE_SYNC; | ||
1300 | } else { | ||
1301 | rw = (pb->pb_flags & PBF_READ) ? READ : WRITE; | ||
1302 | } | ||
1303 | |||
1304 | /* Special code path for reading a sub page size pagebuf in -- | ||
1305 | * we populate up the whole page, and hence the other metadata | ||
1306 | * in the same page. This optimization is only valid when the | ||
1307 | * filesystem block size and the page size are equal. | ||
1308 | */ | ||
1309 | if ((pb->pb_buffer_length < PAGE_CACHE_SIZE) && | ||
1310 | (pb->pb_flags & PBF_READ) && locking && | ||
1311 | (blocksize == PAGE_CACHE_SIZE)) { | ||
1312 | bio = bio_alloc(GFP_NOIO, 1); | ||
1313 | |||
1314 | bio->bi_bdev = pb->pb_target->pbr_bdev; | ||
1315 | bio->bi_sector = sector - (offset >> BBSHIFT); | ||
1316 | bio->bi_end_io = bio_end_io_pagebuf; | ||
1317 | bio->bi_private = pb; | ||
1318 | |||
1319 | bio_add_page(bio, pb->pb_pages[0], PAGE_CACHE_SIZE, 0); | ||
1320 | size = 0; | ||
1321 | |||
1322 | atomic_inc(&pb->pb_io_remaining); | ||
1323 | |||
1324 | goto submit_io; | ||
1325 | } | ||
1326 | |||
1327 | /* Lock down the pages which we need to for the request */ | ||
1328 | if (locking && (pb->pb_flags & PBF_WRITE) && (pb->pb_locked == 0)) { | ||
1329 | for (i = 0; size; i++) { | ||
1330 | int nbytes = PAGE_CACHE_SIZE - offset; | ||
1331 | struct page *page = pb->pb_pages[i]; | ||
1332 | |||
1333 | if (nbytes > size) | ||
1334 | nbytes = size; | ||
1335 | |||
1336 | lock_page(page); | ||
1337 | |||
1338 | size -= nbytes; | ||
1339 | offset = 0; | ||
1340 | } | ||
1341 | offset = pb->pb_offset; | ||
1342 | size = pb->pb_count_desired; | ||
1343 | } | ||
1344 | |||
1345 | next_chunk: | ||
1346 | atomic_inc(&pb->pb_io_remaining); | ||
1347 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); | ||
1348 | if (nr_pages > total_nr_pages) | ||
1349 | nr_pages = total_nr_pages; | ||
1350 | |||
1351 | bio = bio_alloc(GFP_NOIO, nr_pages); | ||
1352 | bio->bi_bdev = pb->pb_target->pbr_bdev; | ||
1353 | bio->bi_sector = sector; | ||
1354 | bio->bi_end_io = bio_end_io_pagebuf; | ||
1355 | bio->bi_private = pb; | ||
1356 | |||
1357 | for (; size && nr_pages; nr_pages--, map_i++) { | ||
1358 | int nbytes = PAGE_CACHE_SIZE - offset; | ||
1359 | |||
1360 | if (nbytes > size) | ||
1361 | nbytes = size; | ||
1362 | |||
1363 | if (bio_add_page(bio, pb->pb_pages[map_i], | ||
1364 | nbytes, offset) < nbytes) | ||
1365 | break; | ||
1366 | |||
1367 | offset = 0; | ||
1368 | sector += nbytes >> BBSHIFT; | ||
1369 | size -= nbytes; | ||
1370 | total_nr_pages--; | ||
1371 | } | ||
1372 | |||
1373 | submit_io: | ||
1374 | if (likely(bio->bi_size)) { | ||
1375 | submit_bio(rw, bio); | ||
1376 | if (size) | ||
1377 | goto next_chunk; | ||
1378 | } else { | ||
1379 | bio_put(bio); | ||
1380 | pagebuf_ioerror(pb, EIO); | ||
1381 | } | ||
1382 | } | ||
1383 | |||
1384 | /* | ||
1385 | * pagebuf_iorequest -- the core I/O request routine. | ||
1386 | */ | ||
1387 | int | ||
1388 | pagebuf_iorequest( /* start real I/O */ | ||
1389 | xfs_buf_t *pb) /* buffer to convey to device */ | ||
1390 | { | ||
1391 | PB_TRACE(pb, "iorequest", 0); | ||
1392 | |||
1393 | if (pb->pb_flags & PBF_DELWRI) { | ||
1394 | pagebuf_delwri_queue(pb, 1); | ||
1395 | return 0; | ||
1396 | } | ||
1397 | |||
1398 | if (pb->pb_flags & PBF_WRITE) { | ||
1399 | _pagebuf_wait_unpin(pb); | ||
1400 | } | ||
1401 | |||
1402 | pagebuf_hold(pb); | ||
1403 | |||
1404 | /* Set the count to 1 initially, this will stop an I/O | ||
1405 | * completion callout which happens before we have started | ||
1406 | * all the I/O from calling pagebuf_iodone too early. | ||
1407 | */ | ||
1408 | atomic_set(&pb->pb_io_remaining, 1); | ||
1409 | _pagebuf_ioapply(pb); | ||
1410 | _pagebuf_iodone(pb, 0); | ||
1411 | |||
1412 | pagebuf_rele(pb); | ||
1413 | return 0; | ||
1414 | } | ||
1415 | |||
1416 | /* | ||
1417 | * pagebuf_iowait | ||
1418 | * | ||
1419 | * pagebuf_iowait waits for I/O to complete on the buffer supplied. | ||
1420 | * It returns immediately if no I/O is pending. In any case, it returns | ||
1421 | * the error code, if any, or 0 if there is no error. | ||
1422 | */ | ||
1423 | int | ||
1424 | pagebuf_iowait( | ||
1425 | xfs_buf_t *pb) | ||
1426 | { | ||
1427 | PB_TRACE(pb, "iowait", 0); | ||
1428 | if (atomic_read(&pb->pb_io_remaining)) | ||
1429 | blk_run_address_space(pb->pb_target->pbr_mapping); | ||
1430 | down(&pb->pb_iodonesema); | ||
1431 | PB_TRACE(pb, "iowaited", (long)pb->pb_error); | ||
1432 | return pb->pb_error; | ||
1433 | } | ||
1434 | |||
1435 | caddr_t | ||
1436 | pagebuf_offset( | ||
1437 | xfs_buf_t *pb, | ||
1438 | size_t offset) | ||
1439 | { | ||
1440 | struct page *page; | ||
1441 | |||
1442 | offset += pb->pb_offset; | ||
1443 | |||
1444 | page = pb->pb_pages[offset >> PAGE_CACHE_SHIFT]; | ||
1445 | return (caddr_t) page_address(page) + (offset & (PAGE_CACHE_SIZE - 1)); | ||
1446 | } | ||
1447 | |||
1448 | /* | ||
1449 | * pagebuf_iomove | ||
1450 | * | ||
1451 | * Move data into or out of a buffer. | ||
1452 | */ | ||
1453 | void | ||
1454 | pagebuf_iomove( | ||
1455 | xfs_buf_t *pb, /* buffer to process */ | ||
1456 | size_t boff, /* starting buffer offset */ | ||
1457 | size_t bsize, /* length to copy */ | ||
1458 | caddr_t data, /* data address */ | ||
1459 | page_buf_rw_t mode) /* read/write flag */ | ||
1460 | { | ||
1461 | size_t bend, cpoff, csize; | ||
1462 | struct page *page; | ||
1463 | |||
1464 | bend = boff + bsize; | ||
1465 | while (boff < bend) { | ||
1466 | page = pb->pb_pages[page_buf_btoct(boff + pb->pb_offset)]; | ||
1467 | cpoff = page_buf_poff(boff + pb->pb_offset); | ||
1468 | csize = min_t(size_t, | ||
1469 | PAGE_CACHE_SIZE-cpoff, pb->pb_count_desired-boff); | ||
1470 | |||
1471 | ASSERT(((csize + cpoff) <= PAGE_CACHE_SIZE)); | ||
1472 | |||
1473 | switch (mode) { | ||
1474 | case PBRW_ZERO: | ||
1475 | memset(page_address(page) + cpoff, 0, csize); | ||
1476 | break; | ||
1477 | case PBRW_READ: | ||
1478 | memcpy(data, page_address(page) + cpoff, csize); | ||
1479 | break; | ||
1480 | case PBRW_WRITE: | ||
1481 | memcpy(page_address(page) + cpoff, data, csize); | ||
1482 | } | ||
1483 | |||
1484 | boff += csize; | ||
1485 | data += csize; | ||
1486 | } | ||
1487 | } | ||
1488 | |||
1489 | /* | ||
1490 | * Handling of buftargs. | ||
1491 | */ | ||
1492 | |||
1493 | /* | ||
1494 | * Wait for any bufs with callbacks that have been submitted but | ||
1495 | * have not yet returned... walk the hash list for the target. | ||
1496 | */ | ||
1497 | void | ||
1498 | xfs_wait_buftarg( | ||
1499 | xfs_buftarg_t *btp) | ||
1500 | { | ||
1501 | xfs_buf_t *bp, *n; | ||
1502 | xfs_bufhash_t *hash; | ||
1503 | uint i; | ||
1504 | |||
1505 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { | ||
1506 | hash = &btp->bt_hash[i]; | ||
1507 | again: | ||
1508 | spin_lock(&hash->bh_lock); | ||
1509 | list_for_each_entry_safe(bp, n, &hash->bh_list, pb_hash_list) { | ||
1510 | ASSERT(btp == bp->pb_target); | ||
1511 | if (!(bp->pb_flags & PBF_FS_MANAGED)) { | ||
1512 | spin_unlock(&hash->bh_lock); | ||
1513 | delay(100); | ||
1514 | goto again; | ||
1515 | } | ||
1516 | } | ||
1517 | spin_unlock(&hash->bh_lock); | ||
1518 | } | ||
1519 | } | ||
1520 | |||
1521 | /* | ||
1522 | * Allocate buffer hash table for a given target. | ||
1523 | * For devices containing metadata (i.e. not the log/realtime devices) | ||
1524 | * we need to allocate a much larger hash table. | ||
1525 | */ | ||
1526 | STATIC void | ||
1527 | xfs_alloc_bufhash( | ||
1528 | xfs_buftarg_t *btp, | ||
1529 | int external) | ||
1530 | { | ||
1531 | unsigned int i; | ||
1532 | |||
1533 | btp->bt_hashshift = external ? 3 : 8; /* 8 or 256 buckets */ | ||
1534 | btp->bt_hashmask = (1 << btp->bt_hashshift) - 1; | ||
1535 | btp->bt_hash = kmem_zalloc((1 << btp->bt_hashshift) * | ||
1536 | sizeof(xfs_bufhash_t), KM_SLEEP); | ||
1537 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { | ||
1538 | spin_lock_init(&btp->bt_hash[i].bh_lock); | ||
1539 | INIT_LIST_HEAD(&btp->bt_hash[i].bh_list); | ||
1540 | } | ||
1541 | } | ||
1542 | |||
1543 | STATIC void | ||
1544 | xfs_free_bufhash( | ||
1545 | xfs_buftarg_t *btp) | ||
1546 | { | ||
1547 | kmem_free(btp->bt_hash, | ||
1548 | (1 << btp->bt_hashshift) * sizeof(xfs_bufhash_t)); | ||
1549 | btp->bt_hash = NULL; | ||
1550 | } | ||
1551 | |||
1552 | void | ||
1553 | xfs_free_buftarg( | ||
1554 | xfs_buftarg_t *btp, | ||
1555 | int external) | ||
1556 | { | ||
1557 | xfs_flush_buftarg(btp, 1); | ||
1558 | if (external) | ||
1559 | xfs_blkdev_put(btp->pbr_bdev); | ||
1560 | xfs_free_bufhash(btp); | ||
1561 | iput(btp->pbr_mapping->host); | ||
1562 | kmem_free(btp, sizeof(*btp)); | ||
1563 | } | ||
1564 | |||
1565 | void | ||
1566 | xfs_incore_relse( | ||
1567 | xfs_buftarg_t *btp, | ||
1568 | int delwri_only, | ||
1569 | int wait) | ||
1570 | { | ||
1571 | invalidate_bdev(btp->pbr_bdev, 1); | ||
1572 | truncate_inode_pages(btp->pbr_mapping, 0LL); | ||
1573 | } | ||
1574 | |||
1575 | STATIC int | ||
1576 | xfs_setsize_buftarg_flags( | ||
1577 | xfs_buftarg_t *btp, | ||
1578 | unsigned int blocksize, | ||
1579 | unsigned int sectorsize, | ||
1580 | int verbose) | ||
1581 | { | ||
1582 | btp->pbr_bsize = blocksize; | ||
1583 | btp->pbr_sshift = ffs(sectorsize) - 1; | ||
1584 | btp->pbr_smask = sectorsize - 1; | ||
1585 | |||
1586 | if (set_blocksize(btp->pbr_bdev, sectorsize)) { | ||
1587 | printk(KERN_WARNING | ||
1588 | "XFS: Cannot set_blocksize to %u on device %s\n", | ||
1589 | sectorsize, XFS_BUFTARG_NAME(btp)); | ||
1590 | return EINVAL; | ||
1591 | } | ||
1592 | |||
1593 | if (verbose && | ||
1594 | (PAGE_CACHE_SIZE / BITS_PER_LONG) > sectorsize) { | ||
1595 | printk(KERN_WARNING | ||
1596 | "XFS: %u byte sectors in use on device %s. " | ||
1597 | "This is suboptimal; %u or greater is ideal.\n", | ||
1598 | sectorsize, XFS_BUFTARG_NAME(btp), | ||
1599 | (unsigned int)PAGE_CACHE_SIZE / BITS_PER_LONG); | ||
1600 | } | ||
1601 | |||
1602 | return 0; | ||
1603 | } | ||
1604 | |||
1605 | /* | ||
1606 | * When allocating the initial buffer target we have not yet | ||
1607 | * read in the superblock, so don't know what sized sectors | ||
1608 | * are being used is at this early stage. Play safe. | ||
1609 | */ | ||
1610 | STATIC int | ||
1611 | xfs_setsize_buftarg_early( | ||
1612 | xfs_buftarg_t *btp, | ||
1613 | struct block_device *bdev) | ||
1614 | { | ||
1615 | return xfs_setsize_buftarg_flags(btp, | ||
1616 | PAGE_CACHE_SIZE, bdev_hardsect_size(bdev), 0); | ||
1617 | } | ||
1618 | |||
1619 | int | ||
1620 | xfs_setsize_buftarg( | ||
1621 | xfs_buftarg_t *btp, | ||
1622 | unsigned int blocksize, | ||
1623 | unsigned int sectorsize) | ||
1624 | { | ||
1625 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | ||
1626 | } | ||
1627 | |||
1628 | STATIC int | ||
1629 | xfs_mapping_buftarg( | ||
1630 | xfs_buftarg_t *btp, | ||
1631 | struct block_device *bdev) | ||
1632 | { | ||
1633 | struct backing_dev_info *bdi; | ||
1634 | struct inode *inode; | ||
1635 | struct address_space *mapping; | ||
1636 | static struct address_space_operations mapping_aops = { | ||
1637 | .sync_page = block_sync_page, | ||
1638 | }; | ||
1639 | |||
1640 | inode = new_inode(bdev->bd_inode->i_sb); | ||
1641 | if (!inode) { | ||
1642 | printk(KERN_WARNING | ||
1643 | "XFS: Cannot allocate mapping inode for device %s\n", | ||
1644 | XFS_BUFTARG_NAME(btp)); | ||
1645 | return ENOMEM; | ||
1646 | } | ||
1647 | inode->i_mode = S_IFBLK; | ||
1648 | inode->i_bdev = bdev; | ||
1649 | inode->i_rdev = bdev->bd_dev; | ||
1650 | bdi = blk_get_backing_dev_info(bdev); | ||
1651 | if (!bdi) | ||
1652 | bdi = &default_backing_dev_info; | ||
1653 | mapping = &inode->i_data; | ||
1654 | mapping->a_ops = &mapping_aops; | ||
1655 | mapping->backing_dev_info = bdi; | ||
1656 | mapping_set_gfp_mask(mapping, GFP_NOFS); | ||
1657 | btp->pbr_mapping = mapping; | ||
1658 | return 0; | ||
1659 | } | ||
1660 | |||
1661 | xfs_buftarg_t * | ||
1662 | xfs_alloc_buftarg( | ||
1663 | struct block_device *bdev, | ||
1664 | int external) | ||
1665 | { | ||
1666 | xfs_buftarg_t *btp; | ||
1667 | |||
1668 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP); | ||
1669 | |||
1670 | btp->pbr_dev = bdev->bd_dev; | ||
1671 | btp->pbr_bdev = bdev; | ||
1672 | if (xfs_setsize_buftarg_early(btp, bdev)) | ||
1673 | goto error; | ||
1674 | if (xfs_mapping_buftarg(btp, bdev)) | ||
1675 | goto error; | ||
1676 | xfs_alloc_bufhash(btp, external); | ||
1677 | return btp; | ||
1678 | |||
1679 | error: | ||
1680 | kmem_free(btp, sizeof(*btp)); | ||
1681 | return NULL; | ||
1682 | } | ||
1683 | |||
1684 | |||
1685 | /* | ||
1686 | * Pagebuf delayed write buffer handling | ||
1687 | */ | ||
1688 | |||
1689 | STATIC LIST_HEAD(pbd_delwrite_queue); | ||
1690 | STATIC DEFINE_SPINLOCK(pbd_delwrite_lock); | ||
1691 | |||
1692 | STATIC void | ||
1693 | pagebuf_delwri_queue( | ||
1694 | xfs_buf_t *pb, | ||
1695 | int unlock) | ||
1696 | { | ||
1697 | PB_TRACE(pb, "delwri_q", (long)unlock); | ||
1698 | ASSERT(pb->pb_flags & PBF_DELWRI); | ||
1699 | |||
1700 | spin_lock(&pbd_delwrite_lock); | ||
1701 | /* If already in the queue, dequeue and place at tail */ | ||
1702 | if (!list_empty(&pb->pb_list)) { | ||
1703 | if (unlock) { | ||
1704 | atomic_dec(&pb->pb_hold); | ||
1705 | } | ||
1706 | list_del(&pb->pb_list); | ||
1707 | } | ||
1708 | |||
1709 | list_add_tail(&pb->pb_list, &pbd_delwrite_queue); | ||
1710 | pb->pb_queuetime = jiffies; | ||
1711 | spin_unlock(&pbd_delwrite_lock); | ||
1712 | |||
1713 | if (unlock) | ||
1714 | pagebuf_unlock(pb); | ||
1715 | } | ||
1716 | |||
1717 | void | ||
1718 | pagebuf_delwri_dequeue( | ||
1719 | xfs_buf_t *pb) | ||
1720 | { | ||
1721 | int dequeued = 0; | ||
1722 | |||
1723 | spin_lock(&pbd_delwrite_lock); | ||
1724 | if ((pb->pb_flags & PBF_DELWRI) && !list_empty(&pb->pb_list)) { | ||
1725 | list_del_init(&pb->pb_list); | ||
1726 | dequeued = 1; | ||
1727 | } | ||
1728 | pb->pb_flags &= ~PBF_DELWRI; | ||
1729 | spin_unlock(&pbd_delwrite_lock); | ||
1730 | |||
1731 | if (dequeued) | ||
1732 | pagebuf_rele(pb); | ||
1733 | |||
1734 | PB_TRACE(pb, "delwri_dq", (long)dequeued); | ||
1735 | } | ||
1736 | |||
1737 | STATIC void | ||
1738 | pagebuf_runall_queues( | ||
1739 | struct workqueue_struct *queue) | ||
1740 | { | ||
1741 | flush_workqueue(queue); | ||
1742 | } | ||
1743 | |||
1744 | /* Defines for pagebuf daemon */ | ||
1745 | STATIC DECLARE_COMPLETION(pagebuf_daemon_done); | ||
1746 | STATIC struct task_struct *pagebuf_daemon_task; | ||
1747 | STATIC int pagebuf_daemon_active; | ||
1748 | STATIC int force_flush; | ||
1749 | |||
1750 | |||
1751 | STATIC int | ||
1752 | pagebuf_daemon_wakeup( | ||
1753 | int priority, | ||
1754 | unsigned int mask) | ||
1755 | { | ||
1756 | force_flush = 1; | ||
1757 | barrier(); | ||
1758 | wake_up_process(pagebuf_daemon_task); | ||
1759 | return 0; | ||
1760 | } | ||
1761 | |||
1762 | STATIC int | ||
1763 | pagebuf_daemon( | ||
1764 | void *data) | ||
1765 | { | ||
1766 | struct list_head tmp; | ||
1767 | unsigned long age; | ||
1768 | xfs_buftarg_t *target; | ||
1769 | xfs_buf_t *pb, *n; | ||
1770 | |||
1771 | /* Set up the thread */ | ||
1772 | daemonize("xfsbufd"); | ||
1773 | current->flags |= PF_MEMALLOC; | ||
1774 | |||
1775 | pagebuf_daemon_task = current; | ||
1776 | pagebuf_daemon_active = 1; | ||
1777 | barrier(); | ||
1778 | |||
1779 | INIT_LIST_HEAD(&tmp); | ||
1780 | do { | ||
1781 | try_to_freeze(PF_FREEZE); | ||
1782 | |||
1783 | set_current_state(TASK_INTERRUPTIBLE); | ||
1784 | schedule_timeout((xfs_buf_timer_centisecs * HZ) / 100); | ||
1785 | |||
1786 | age = (xfs_buf_age_centisecs * HZ) / 100; | ||
1787 | spin_lock(&pbd_delwrite_lock); | ||
1788 | list_for_each_entry_safe(pb, n, &pbd_delwrite_queue, pb_list) { | ||
1789 | PB_TRACE(pb, "walkq1", (long)pagebuf_ispin(pb)); | ||
1790 | ASSERT(pb->pb_flags & PBF_DELWRI); | ||
1791 | |||
1792 | if (!pagebuf_ispin(pb) && !pagebuf_cond_lock(pb)) { | ||
1793 | if (!force_flush && | ||
1794 | time_before(jiffies, | ||
1795 | pb->pb_queuetime + age)) { | ||
1796 | pagebuf_unlock(pb); | ||
1797 | break; | ||
1798 | } | ||
1799 | |||
1800 | pb->pb_flags &= ~PBF_DELWRI; | ||
1801 | pb->pb_flags |= PBF_WRITE; | ||
1802 | list_move(&pb->pb_list, &tmp); | ||
1803 | } | ||
1804 | } | ||
1805 | spin_unlock(&pbd_delwrite_lock); | ||
1806 | |||
1807 | while (!list_empty(&tmp)) { | ||
1808 | pb = list_entry(tmp.next, xfs_buf_t, pb_list); | ||
1809 | target = pb->pb_target; | ||
1810 | |||
1811 | list_del_init(&pb->pb_list); | ||
1812 | pagebuf_iostrategy(pb); | ||
1813 | |||
1814 | blk_run_address_space(target->pbr_mapping); | ||
1815 | } | ||
1816 | |||
1817 | if (as_list_len > 0) | ||
1818 | purge_addresses(); | ||
1819 | |||
1820 | force_flush = 0; | ||
1821 | } while (pagebuf_daemon_active); | ||
1822 | |||
1823 | complete_and_exit(&pagebuf_daemon_done, 0); | ||
1824 | } | ||
1825 | |||
1826 | /* | ||
1827 | * Go through all incore buffers, and release buffers if they belong to | ||
1828 | * the given device. This is used in filesystem error handling to | ||
1829 | * preserve the consistency of its metadata. | ||
1830 | */ | ||
1831 | int | ||
1832 | xfs_flush_buftarg( | ||
1833 | xfs_buftarg_t *target, | ||
1834 | int wait) | ||
1835 | { | ||
1836 | struct list_head tmp; | ||
1837 | xfs_buf_t *pb, *n; | ||
1838 | int pincount = 0; | ||
1839 | |||
1840 | pagebuf_runall_queues(pagebuf_dataio_workqueue); | ||
1841 | pagebuf_runall_queues(pagebuf_logio_workqueue); | ||
1842 | |||
1843 | INIT_LIST_HEAD(&tmp); | ||
1844 | spin_lock(&pbd_delwrite_lock); | ||
1845 | list_for_each_entry_safe(pb, n, &pbd_delwrite_queue, pb_list) { | ||
1846 | |||
1847 | if (pb->pb_target != target) | ||
1848 | continue; | ||
1849 | |||
1850 | ASSERT(pb->pb_flags & PBF_DELWRI); | ||
1851 | PB_TRACE(pb, "walkq2", (long)pagebuf_ispin(pb)); | ||
1852 | if (pagebuf_ispin(pb)) { | ||
1853 | pincount++; | ||
1854 | continue; | ||
1855 | } | ||
1856 | |||
1857 | pb->pb_flags &= ~PBF_DELWRI; | ||
1858 | pb->pb_flags |= PBF_WRITE; | ||
1859 | list_move(&pb->pb_list, &tmp); | ||
1860 | } | ||
1861 | spin_unlock(&pbd_delwrite_lock); | ||
1862 | |||
1863 | /* | ||
1864 | * Dropped the delayed write list lock, now walk the temporary list | ||
1865 | */ | ||
1866 | list_for_each_entry_safe(pb, n, &tmp, pb_list) { | ||
1867 | if (wait) | ||
1868 | pb->pb_flags &= ~PBF_ASYNC; | ||
1869 | else | ||
1870 | list_del_init(&pb->pb_list); | ||
1871 | |||
1872 | pagebuf_lock(pb); | ||
1873 | pagebuf_iostrategy(pb); | ||
1874 | } | ||
1875 | |||
1876 | /* | ||
1877 | * Remaining list items must be flushed before returning | ||
1878 | */ | ||
1879 | while (!list_empty(&tmp)) { | ||
1880 | pb = list_entry(tmp.next, xfs_buf_t, pb_list); | ||
1881 | |||
1882 | list_del_init(&pb->pb_list); | ||
1883 | xfs_iowait(pb); | ||
1884 | xfs_buf_relse(pb); | ||
1885 | } | ||
1886 | |||
1887 | if (wait) | ||
1888 | blk_run_address_space(target->pbr_mapping); | ||
1889 | |||
1890 | return pincount; | ||
1891 | } | ||
1892 | |||
1893 | STATIC int | ||
1894 | pagebuf_daemon_start(void) | ||
1895 | { | ||
1896 | int rval; | ||
1897 | |||
1898 | pagebuf_logio_workqueue = create_workqueue("xfslogd"); | ||
1899 | if (!pagebuf_logio_workqueue) | ||
1900 | return -ENOMEM; | ||
1901 | |||
1902 | pagebuf_dataio_workqueue = create_workqueue("xfsdatad"); | ||
1903 | if (!pagebuf_dataio_workqueue) { | ||
1904 | destroy_workqueue(pagebuf_logio_workqueue); | ||
1905 | return -ENOMEM; | ||
1906 | } | ||
1907 | |||
1908 | rval = kernel_thread(pagebuf_daemon, NULL, CLONE_FS|CLONE_FILES); | ||
1909 | if (rval < 0) { | ||
1910 | destroy_workqueue(pagebuf_logio_workqueue); | ||
1911 | destroy_workqueue(pagebuf_dataio_workqueue); | ||
1912 | } | ||
1913 | |||
1914 | return rval; | ||
1915 | } | ||
1916 | |||
1917 | /* | ||
1918 | * pagebuf_daemon_stop | ||
1919 | * | ||
1920 | * Note: do not mark as __exit, it is called from pagebuf_terminate. | ||
1921 | */ | ||
1922 | STATIC void | ||
1923 | pagebuf_daemon_stop(void) | ||
1924 | { | ||
1925 | pagebuf_daemon_active = 0; | ||
1926 | barrier(); | ||
1927 | wait_for_completion(&pagebuf_daemon_done); | ||
1928 | |||
1929 | destroy_workqueue(pagebuf_logio_workqueue); | ||
1930 | destroy_workqueue(pagebuf_dataio_workqueue); | ||
1931 | } | ||
1932 | |||
1933 | /* | ||
1934 | * Initialization and Termination | ||
1935 | */ | ||
1936 | |||
1937 | int __init | ||
1938 | pagebuf_init(void) | ||
1939 | { | ||
1940 | pagebuf_cache = kmem_cache_create("xfs_buf_t", sizeof(xfs_buf_t), 0, | ||
1941 | SLAB_HWCACHE_ALIGN, NULL, NULL); | ||
1942 | if (pagebuf_cache == NULL) { | ||
1943 | printk("XFS: couldn't init xfs_buf_t cache\n"); | ||
1944 | pagebuf_terminate(); | ||
1945 | return -ENOMEM; | ||
1946 | } | ||
1947 | |||
1948 | #ifdef PAGEBUF_TRACE | ||
1949 | pagebuf_trace_buf = ktrace_alloc(PAGEBUF_TRACE_SIZE, KM_SLEEP); | ||
1950 | #endif | ||
1951 | |||
1952 | pagebuf_daemon_start(); | ||
1953 | |||
1954 | pagebuf_shake = kmem_shake_register(pagebuf_daemon_wakeup); | ||
1955 | if (pagebuf_shake == NULL) { | ||
1956 | pagebuf_terminate(); | ||
1957 | return -ENOMEM; | ||
1958 | } | ||
1959 | |||
1960 | return 0; | ||
1961 | } | ||
1962 | |||
1963 | |||
1964 | /* | ||
1965 | * pagebuf_terminate. | ||
1966 | * | ||
1967 | * Note: do not mark as __exit, this is also called from the __init code. | ||
1968 | */ | ||
1969 | void | ||
1970 | pagebuf_terminate(void) | ||
1971 | { | ||
1972 | pagebuf_daemon_stop(); | ||
1973 | |||
1974 | #ifdef PAGEBUF_TRACE | ||
1975 | ktrace_free(pagebuf_trace_buf); | ||
1976 | #endif | ||
1977 | |||
1978 | kmem_zone_destroy(pagebuf_cache); | ||
1979 | kmem_shake_deregister(pagebuf_shake); | ||
1980 | } | ||