Commit | Line | Data |
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1da177e4 | 1 | /* |
7b718769 NS |
2 | * Copyright (c) 2000-2005 Silicon Graphics, Inc. |
3 | * All Rights Reserved. | |
1da177e4 | 4 | * |
7b718769 NS |
5 | * This program is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU General Public License as | |
1da177e4 LT |
7 | * published by the Free Software Foundation. |
8 | * | |
7b718769 NS |
9 | * This program is distributed in the hope that it would be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
1da177e4 | 13 | * |
7b718769 NS |
14 | * You should have received a copy of the GNU General Public License |
15 | * along with this program; if not, write the Free Software Foundation, | |
16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
1da177e4 | 17 | */ |
1da177e4 LT |
18 | #include <linux/stddef.h> |
19 | #include <linux/errno.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/pagemap.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/vmalloc.h> | |
24 | #include <linux/bio.h> | |
25 | #include <linux/sysctl.h> | |
26 | #include <linux/proc_fs.h> | |
27 | #include <linux/workqueue.h> | |
28 | #include <linux/percpu.h> | |
29 | #include <linux/blkdev.h> | |
30 | #include <linux/hash.h> | |
4df08c52 | 31 | #include <linux/kthread.h> |
1da177e4 LT |
32 | #include "xfs_linux.h" |
33 | ||
23ea4032 | 34 | STATIC kmem_cache_t *pagebuf_zone; |
1da177e4 | 35 | STATIC kmem_shaker_t pagebuf_shake; |
a6867a68 | 36 | STATIC int xfsbufd(void *); |
27496a8c | 37 | STATIC int xfsbufd_wakeup(int, gfp_t); |
1da177e4 | 38 | STATIC void pagebuf_delwri_queue(xfs_buf_t *, int); |
23ea4032 CH |
39 | |
40 | STATIC struct workqueue_struct *xfslogd_workqueue; | |
0829c360 | 41 | struct workqueue_struct *xfsdatad_workqueue; |
1da177e4 | 42 | |
1da177e4 LT |
43 | #ifdef PAGEBUF_TRACE |
44 | void | |
45 | pagebuf_trace( | |
46 | xfs_buf_t *pb, | |
47 | char *id, | |
48 | void *data, | |
49 | void *ra) | |
50 | { | |
51 | ktrace_enter(pagebuf_trace_buf, | |
52 | pb, id, | |
53 | (void *)(unsigned long)pb->pb_flags, | |
54 | (void *)(unsigned long)pb->pb_hold.counter, | |
55 | (void *)(unsigned long)pb->pb_sema.count.counter, | |
56 | (void *)current, | |
57 | data, ra, | |
58 | (void *)(unsigned long)((pb->pb_file_offset>>32) & 0xffffffff), | |
59 | (void *)(unsigned long)(pb->pb_file_offset & 0xffffffff), | |
60 | (void *)(unsigned long)pb->pb_buffer_length, | |
61 | NULL, NULL, NULL, NULL, NULL); | |
62 | } | |
63 | ktrace_t *pagebuf_trace_buf; | |
64 | #define PAGEBUF_TRACE_SIZE 4096 | |
65 | #define PB_TRACE(pb, id, data) \ | |
66 | pagebuf_trace(pb, id, (void *)data, (void *)__builtin_return_address(0)) | |
67 | #else | |
68 | #define PB_TRACE(pb, id, data) do { } while (0) | |
69 | #endif | |
70 | ||
71 | #ifdef PAGEBUF_LOCK_TRACKING | |
72 | # define PB_SET_OWNER(pb) ((pb)->pb_last_holder = current->pid) | |
73 | # define PB_CLEAR_OWNER(pb) ((pb)->pb_last_holder = -1) | |
74 | # define PB_GET_OWNER(pb) ((pb)->pb_last_holder) | |
75 | #else | |
76 | # define PB_SET_OWNER(pb) do { } while (0) | |
77 | # define PB_CLEAR_OWNER(pb) do { } while (0) | |
78 | # define PB_GET_OWNER(pb) do { } while (0) | |
79 | #endif | |
80 | ||
1da177e4 LT |
81 | #define pb_to_gfp(flags) \ |
82 | ((((flags) & PBF_READ_AHEAD) ? __GFP_NORETRY : \ | |
83 | ((flags) & PBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN) | |
84 | ||
85 | #define pb_to_km(flags) \ | |
86 | (((flags) & PBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP) | |
87 | ||
1da177e4 | 88 | #define pagebuf_allocate(flags) \ |
23ea4032 | 89 | kmem_zone_alloc(pagebuf_zone, pb_to_km(flags)) |
1da177e4 | 90 | #define pagebuf_deallocate(pb) \ |
23ea4032 | 91 | kmem_zone_free(pagebuf_zone, (pb)); |
1da177e4 LT |
92 | |
93 | /* | |
94 | * Page Region interfaces. | |
95 | * | |
96 | * For pages in filesystems where the blocksize is smaller than the | |
97 | * pagesize, we use the page->private field (long) to hold a bitmap | |
98 | * of uptodate regions within the page. | |
99 | * | |
100 | * Each such region is "bytes per page / bits per long" bytes long. | |
101 | * | |
102 | * NBPPR == number-of-bytes-per-page-region | |
103 | * BTOPR == bytes-to-page-region (rounded up) | |
104 | * BTOPRT == bytes-to-page-region-truncated (rounded down) | |
105 | */ | |
106 | #if (BITS_PER_LONG == 32) | |
107 | #define PRSHIFT (PAGE_CACHE_SHIFT - 5) /* (32 == 1<<5) */ | |
108 | #elif (BITS_PER_LONG == 64) | |
109 | #define PRSHIFT (PAGE_CACHE_SHIFT - 6) /* (64 == 1<<6) */ | |
110 | #else | |
111 | #error BITS_PER_LONG must be 32 or 64 | |
112 | #endif | |
113 | #define NBPPR (PAGE_CACHE_SIZE/BITS_PER_LONG) | |
114 | #define BTOPR(b) (((unsigned int)(b) + (NBPPR - 1)) >> PRSHIFT) | |
115 | #define BTOPRT(b) (((unsigned int)(b) >> PRSHIFT)) | |
116 | ||
117 | STATIC unsigned long | |
118 | page_region_mask( | |
119 | size_t offset, | |
120 | size_t length) | |
121 | { | |
122 | unsigned long mask; | |
123 | int first, final; | |
124 | ||
125 | first = BTOPR(offset); | |
126 | final = BTOPRT(offset + length - 1); | |
127 | first = min(first, final); | |
128 | ||
129 | mask = ~0UL; | |
130 | mask <<= BITS_PER_LONG - (final - first); | |
131 | mask >>= BITS_PER_LONG - (final); | |
132 | ||
133 | ASSERT(offset + length <= PAGE_CACHE_SIZE); | |
134 | ASSERT((final - first) < BITS_PER_LONG && (final - first) >= 0); | |
135 | ||
136 | return mask; | |
137 | } | |
138 | ||
139 | STATIC inline void | |
140 | set_page_region( | |
141 | struct page *page, | |
142 | size_t offset, | |
143 | size_t length) | |
144 | { | |
4c21e2f2 HD |
145 | set_page_private(page, |
146 | page_private(page) | page_region_mask(offset, length)); | |
147 | if (page_private(page) == ~0UL) | |
1da177e4 LT |
148 | SetPageUptodate(page); |
149 | } | |
150 | ||
151 | STATIC inline int | |
152 | test_page_region( | |
153 | struct page *page, | |
154 | size_t offset, | |
155 | size_t length) | |
156 | { | |
157 | unsigned long mask = page_region_mask(offset, length); | |
158 | ||
4c21e2f2 | 159 | return (mask && (page_private(page) & mask) == mask); |
1da177e4 LT |
160 | } |
161 | ||
162 | /* | |
163 | * Mapping of multi-page buffers into contiguous virtual space | |
164 | */ | |
165 | ||
166 | typedef struct a_list { | |
167 | void *vm_addr; | |
168 | struct a_list *next; | |
169 | } a_list_t; | |
170 | ||
171 | STATIC a_list_t *as_free_head; | |
172 | STATIC int as_list_len; | |
173 | STATIC DEFINE_SPINLOCK(as_lock); | |
174 | ||
175 | /* | |
176 | * Try to batch vunmaps because they are costly. | |
177 | */ | |
178 | STATIC void | |
179 | free_address( | |
180 | void *addr) | |
181 | { | |
182 | a_list_t *aentry; | |
183 | ||
184 | aentry = kmalloc(sizeof(a_list_t), GFP_ATOMIC & ~__GFP_HIGH); | |
185 | if (likely(aentry)) { | |
186 | spin_lock(&as_lock); | |
187 | aentry->next = as_free_head; | |
188 | aentry->vm_addr = addr; | |
189 | as_free_head = aentry; | |
190 | as_list_len++; | |
191 | spin_unlock(&as_lock); | |
192 | } else { | |
193 | vunmap(addr); | |
194 | } | |
195 | } | |
196 | ||
197 | STATIC void | |
198 | purge_addresses(void) | |
199 | { | |
200 | a_list_t *aentry, *old; | |
201 | ||
202 | if (as_free_head == NULL) | |
203 | return; | |
204 | ||
205 | spin_lock(&as_lock); | |
206 | aentry = as_free_head; | |
207 | as_free_head = NULL; | |
208 | as_list_len = 0; | |
209 | spin_unlock(&as_lock); | |
210 | ||
211 | while ((old = aentry) != NULL) { | |
212 | vunmap(aentry->vm_addr); | |
213 | aentry = aentry->next; | |
214 | kfree(old); | |
215 | } | |
216 | } | |
217 | ||
218 | /* | |
219 | * Internal pagebuf object manipulation | |
220 | */ | |
221 | ||
222 | STATIC void | |
223 | _pagebuf_initialize( | |
224 | xfs_buf_t *pb, | |
225 | xfs_buftarg_t *target, | |
226 | loff_t range_base, | |
227 | size_t range_length, | |
228 | page_buf_flags_t flags) | |
229 | { | |
230 | /* | |
231 | * We don't want certain flags to appear in pb->pb_flags. | |
232 | */ | |
233 | flags &= ~(PBF_LOCK|PBF_MAPPED|PBF_DONT_BLOCK|PBF_READ_AHEAD); | |
234 | ||
235 | memset(pb, 0, sizeof(xfs_buf_t)); | |
236 | atomic_set(&pb->pb_hold, 1); | |
237 | init_MUTEX_LOCKED(&pb->pb_iodonesema); | |
238 | INIT_LIST_HEAD(&pb->pb_list); | |
239 | INIT_LIST_HEAD(&pb->pb_hash_list); | |
240 | init_MUTEX_LOCKED(&pb->pb_sema); /* held, no waiters */ | |
241 | PB_SET_OWNER(pb); | |
242 | pb->pb_target = target; | |
243 | pb->pb_file_offset = range_base; | |
244 | /* | |
245 | * Set buffer_length and count_desired to the same value initially. | |
246 | * I/O routines should use count_desired, which will be the same in | |
247 | * most cases but may be reset (e.g. XFS recovery). | |
248 | */ | |
249 | pb->pb_buffer_length = pb->pb_count_desired = range_length; | |
c86e711c | 250 | pb->pb_flags = flags; |
1da177e4 LT |
251 | pb->pb_bn = XFS_BUF_DADDR_NULL; |
252 | atomic_set(&pb->pb_pin_count, 0); | |
253 | init_waitqueue_head(&pb->pb_waiters); | |
254 | ||
255 | XFS_STATS_INC(pb_create); | |
256 | PB_TRACE(pb, "initialize", target); | |
257 | } | |
258 | ||
259 | /* | |
260 | * Allocate a page array capable of holding a specified number | |
261 | * of pages, and point the page buf at it. | |
262 | */ | |
263 | STATIC int | |
264 | _pagebuf_get_pages( | |
265 | xfs_buf_t *pb, | |
266 | int page_count, | |
267 | page_buf_flags_t flags) | |
268 | { | |
269 | /* Make sure that we have a page list */ | |
270 | if (pb->pb_pages == NULL) { | |
271 | pb->pb_offset = page_buf_poff(pb->pb_file_offset); | |
272 | pb->pb_page_count = page_count; | |
273 | if (page_count <= PB_PAGES) { | |
274 | pb->pb_pages = pb->pb_page_array; | |
275 | } else { | |
276 | pb->pb_pages = kmem_alloc(sizeof(struct page *) * | |
277 | page_count, pb_to_km(flags)); | |
278 | if (pb->pb_pages == NULL) | |
279 | return -ENOMEM; | |
280 | } | |
281 | memset(pb->pb_pages, 0, sizeof(struct page *) * page_count); | |
282 | } | |
283 | return 0; | |
284 | } | |
285 | ||
286 | /* | |
287 | * Frees pb_pages if it was malloced. | |
288 | */ | |
289 | STATIC void | |
290 | _pagebuf_free_pages( | |
291 | xfs_buf_t *bp) | |
292 | { | |
293 | if (bp->pb_pages != bp->pb_page_array) { | |
294 | kmem_free(bp->pb_pages, | |
295 | bp->pb_page_count * sizeof(struct page *)); | |
296 | } | |
297 | } | |
298 | ||
299 | /* | |
300 | * Releases the specified buffer. | |
301 | * | |
302 | * The modification state of any associated pages is left unchanged. | |
303 | * The buffer most not be on any hash - use pagebuf_rele instead for | |
304 | * hashed and refcounted buffers | |
305 | */ | |
306 | void | |
307 | pagebuf_free( | |
308 | xfs_buf_t *bp) | |
309 | { | |
310 | PB_TRACE(bp, "free", 0); | |
311 | ||
312 | ASSERT(list_empty(&bp->pb_hash_list)); | |
313 | ||
314 | if (bp->pb_flags & _PBF_PAGE_CACHE) { | |
315 | uint i; | |
316 | ||
317 | if ((bp->pb_flags & PBF_MAPPED) && (bp->pb_page_count > 1)) | |
318 | free_address(bp->pb_addr - bp->pb_offset); | |
319 | ||
320 | for (i = 0; i < bp->pb_page_count; i++) | |
321 | page_cache_release(bp->pb_pages[i]); | |
322 | _pagebuf_free_pages(bp); | |
323 | } else if (bp->pb_flags & _PBF_KMEM_ALLOC) { | |
324 | /* | |
325 | * XXX(hch): bp->pb_count_desired might be incorrect (see | |
326 | * pagebuf_associate_memory for details), but fortunately | |
327 | * the Linux version of kmem_free ignores the len argument.. | |
328 | */ | |
329 | kmem_free(bp->pb_addr, bp->pb_count_desired); | |
330 | _pagebuf_free_pages(bp); | |
331 | } | |
332 | ||
333 | pagebuf_deallocate(bp); | |
334 | } | |
335 | ||
336 | /* | |
337 | * Finds all pages for buffer in question and builds it's page list. | |
338 | */ | |
339 | STATIC int | |
340 | _pagebuf_lookup_pages( | |
341 | xfs_buf_t *bp, | |
342 | uint flags) | |
343 | { | |
344 | struct address_space *mapping = bp->pb_target->pbr_mapping; | |
345 | size_t blocksize = bp->pb_target->pbr_bsize; | |
346 | size_t size = bp->pb_count_desired; | |
347 | size_t nbytes, offset; | |
27496a8c | 348 | gfp_t gfp_mask = pb_to_gfp(flags); |
1da177e4 LT |
349 | unsigned short page_count, i; |
350 | pgoff_t first; | |
351 | loff_t end; | |
352 | int error; | |
353 | ||
354 | end = bp->pb_file_offset + bp->pb_buffer_length; | |
355 | page_count = page_buf_btoc(end) - page_buf_btoct(bp->pb_file_offset); | |
356 | ||
357 | error = _pagebuf_get_pages(bp, page_count, flags); | |
358 | if (unlikely(error)) | |
359 | return error; | |
360 | bp->pb_flags |= _PBF_PAGE_CACHE; | |
361 | ||
362 | offset = bp->pb_offset; | |
363 | first = bp->pb_file_offset >> PAGE_CACHE_SHIFT; | |
364 | ||
365 | for (i = 0; i < bp->pb_page_count; i++) { | |
366 | struct page *page; | |
367 | uint retries = 0; | |
368 | ||
369 | retry: | |
370 | page = find_or_create_page(mapping, first + i, gfp_mask); | |
371 | if (unlikely(page == NULL)) { | |
372 | if (flags & PBF_READ_AHEAD) { | |
373 | bp->pb_page_count = i; | |
374 | for (i = 0; i < bp->pb_page_count; i++) | |
375 | unlock_page(bp->pb_pages[i]); | |
376 | return -ENOMEM; | |
377 | } | |
378 | ||
379 | /* | |
380 | * This could deadlock. | |
381 | * | |
382 | * But until all the XFS lowlevel code is revamped to | |
383 | * handle buffer allocation failures we can't do much. | |
384 | */ | |
385 | if (!(++retries % 100)) | |
386 | printk(KERN_ERR | |
387 | "XFS: possible memory allocation " | |
388 | "deadlock in %s (mode:0x%x)\n", | |
389 | __FUNCTION__, gfp_mask); | |
390 | ||
391 | XFS_STATS_INC(pb_page_retries); | |
23ea4032 | 392 | xfsbufd_wakeup(0, gfp_mask); |
1da177e4 LT |
393 | blk_congestion_wait(WRITE, HZ/50); |
394 | goto retry; | |
395 | } | |
396 | ||
397 | XFS_STATS_INC(pb_page_found); | |
398 | ||
399 | nbytes = min_t(size_t, size, PAGE_CACHE_SIZE - offset); | |
400 | size -= nbytes; | |
401 | ||
402 | if (!PageUptodate(page)) { | |
403 | page_count--; | |
404 | if (blocksize >= PAGE_CACHE_SIZE) { | |
405 | if (flags & PBF_READ) | |
406 | bp->pb_locked = 1; | |
407 | } else if (!PagePrivate(page)) { | |
408 | if (test_page_region(page, offset, nbytes)) | |
409 | page_count++; | |
410 | } | |
411 | } | |
412 | ||
413 | bp->pb_pages[i] = page; | |
414 | offset = 0; | |
415 | } | |
416 | ||
417 | if (!bp->pb_locked) { | |
418 | for (i = 0; i < bp->pb_page_count; i++) | |
419 | unlock_page(bp->pb_pages[i]); | |
420 | } | |
421 | ||
c86e711c CH |
422 | if (page_count == bp->pb_page_count) |
423 | bp->pb_flags |= PBF_DONE; | |
1da177e4 LT |
424 | |
425 | PB_TRACE(bp, "lookup_pages", (long)page_count); | |
426 | return error; | |
427 | } | |
428 | ||
429 | /* | |
430 | * Map buffer into kernel address-space if nessecary. | |
431 | */ | |
432 | STATIC int | |
433 | _pagebuf_map_pages( | |
434 | xfs_buf_t *bp, | |
435 | uint flags) | |
436 | { | |
437 | /* A single page buffer is always mappable */ | |
438 | if (bp->pb_page_count == 1) { | |
439 | bp->pb_addr = page_address(bp->pb_pages[0]) + bp->pb_offset; | |
440 | bp->pb_flags |= PBF_MAPPED; | |
441 | } else if (flags & PBF_MAPPED) { | |
442 | if (as_list_len > 64) | |
443 | purge_addresses(); | |
444 | bp->pb_addr = vmap(bp->pb_pages, bp->pb_page_count, | |
445 | VM_MAP, PAGE_KERNEL); | |
446 | if (unlikely(bp->pb_addr == NULL)) | |
447 | return -ENOMEM; | |
448 | bp->pb_addr += bp->pb_offset; | |
449 | bp->pb_flags |= PBF_MAPPED; | |
450 | } | |
451 | ||
452 | return 0; | |
453 | } | |
454 | ||
455 | /* | |
456 | * Finding and Reading Buffers | |
457 | */ | |
458 | ||
459 | /* | |
460 | * _pagebuf_find | |
461 | * | |
462 | * Looks up, and creates if absent, a lockable buffer for | |
463 | * a given range of an inode. The buffer is returned | |
464 | * locked. If other overlapping buffers exist, they are | |
465 | * released before the new buffer is created and locked, | |
466 | * which may imply that this call will block until those buffers | |
467 | * are unlocked. No I/O is implied by this call. | |
468 | */ | |
469 | xfs_buf_t * | |
470 | _pagebuf_find( | |
471 | xfs_buftarg_t *btp, /* block device target */ | |
472 | loff_t ioff, /* starting offset of range */ | |
473 | size_t isize, /* length of range */ | |
474 | page_buf_flags_t flags, /* PBF_TRYLOCK */ | |
475 | xfs_buf_t *new_pb)/* newly allocated buffer */ | |
476 | { | |
477 | loff_t range_base; | |
478 | size_t range_length; | |
479 | xfs_bufhash_t *hash; | |
480 | xfs_buf_t *pb, *n; | |
481 | ||
482 | range_base = (ioff << BBSHIFT); | |
483 | range_length = (isize << BBSHIFT); | |
484 | ||
485 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
486 | ASSERT(!(range_length < (1 << btp->pbr_sshift))); | |
487 | ASSERT(!(range_base & (loff_t)btp->pbr_smask)); | |
488 | ||
489 | hash = &btp->bt_hash[hash_long((unsigned long)ioff, btp->bt_hashshift)]; | |
490 | ||
491 | spin_lock(&hash->bh_lock); | |
492 | ||
493 | list_for_each_entry_safe(pb, n, &hash->bh_list, pb_hash_list) { | |
494 | ASSERT(btp == pb->pb_target); | |
495 | if (pb->pb_file_offset == range_base && | |
496 | pb->pb_buffer_length == range_length) { | |
497 | /* | |
498 | * If we look at something bring it to the | |
499 | * front of the list for next time. | |
500 | */ | |
501 | atomic_inc(&pb->pb_hold); | |
502 | list_move(&pb->pb_hash_list, &hash->bh_list); | |
503 | goto found; | |
504 | } | |
505 | } | |
506 | ||
507 | /* No match found */ | |
508 | if (new_pb) { | |
509 | _pagebuf_initialize(new_pb, btp, range_base, | |
510 | range_length, flags); | |
511 | new_pb->pb_hash = hash; | |
512 | list_add(&new_pb->pb_hash_list, &hash->bh_list); | |
513 | } else { | |
514 | XFS_STATS_INC(pb_miss_locked); | |
515 | } | |
516 | ||
517 | spin_unlock(&hash->bh_lock); | |
518 | return new_pb; | |
519 | ||
520 | found: | |
521 | spin_unlock(&hash->bh_lock); | |
522 | ||
523 | /* Attempt to get the semaphore without sleeping, | |
524 | * if this does not work then we need to drop the | |
525 | * spinlock and do a hard attempt on the semaphore. | |
526 | */ | |
527 | if (down_trylock(&pb->pb_sema)) { | |
528 | if (!(flags & PBF_TRYLOCK)) { | |
529 | /* wait for buffer ownership */ | |
530 | PB_TRACE(pb, "get_lock", 0); | |
531 | pagebuf_lock(pb); | |
532 | XFS_STATS_INC(pb_get_locked_waited); | |
533 | } else { | |
534 | /* We asked for a trylock and failed, no need | |
535 | * to look at file offset and length here, we | |
536 | * know that this pagebuf at least overlaps our | |
537 | * pagebuf and is locked, therefore our buffer | |
538 | * either does not exist, or is this buffer | |
539 | */ | |
540 | ||
541 | pagebuf_rele(pb); | |
542 | XFS_STATS_INC(pb_busy_locked); | |
543 | return (NULL); | |
544 | } | |
545 | } else { | |
546 | /* trylock worked */ | |
547 | PB_SET_OWNER(pb); | |
548 | } | |
549 | ||
2f926587 DC |
550 | if (pb->pb_flags & PBF_STALE) { |
551 | ASSERT((pb->pb_flags & _PBF_DELWRI_Q) == 0); | |
1da177e4 | 552 | pb->pb_flags &= PBF_MAPPED; |
2f926587 | 553 | } |
1da177e4 LT |
554 | PB_TRACE(pb, "got_lock", 0); |
555 | XFS_STATS_INC(pb_get_locked); | |
556 | return (pb); | |
557 | } | |
558 | ||
559 | /* | |
560 | * xfs_buf_get_flags assembles a buffer covering the specified range. | |
561 | * | |
562 | * Storage in memory for all portions of the buffer will be allocated, | |
563 | * although backing storage may not be. | |
564 | */ | |
565 | xfs_buf_t * | |
566 | xfs_buf_get_flags( /* allocate a buffer */ | |
567 | xfs_buftarg_t *target,/* target for buffer */ | |
568 | loff_t ioff, /* starting offset of range */ | |
569 | size_t isize, /* length of range */ | |
570 | page_buf_flags_t flags) /* PBF_TRYLOCK */ | |
571 | { | |
572 | xfs_buf_t *pb, *new_pb; | |
573 | int error = 0, i; | |
574 | ||
575 | new_pb = pagebuf_allocate(flags); | |
576 | if (unlikely(!new_pb)) | |
577 | return NULL; | |
578 | ||
579 | pb = _pagebuf_find(target, ioff, isize, flags, new_pb); | |
580 | if (pb == new_pb) { | |
581 | error = _pagebuf_lookup_pages(pb, flags); | |
582 | if (error) | |
583 | goto no_buffer; | |
584 | } else { | |
585 | pagebuf_deallocate(new_pb); | |
586 | if (unlikely(pb == NULL)) | |
587 | return NULL; | |
588 | } | |
589 | ||
590 | for (i = 0; i < pb->pb_page_count; i++) | |
591 | mark_page_accessed(pb->pb_pages[i]); | |
592 | ||
593 | if (!(pb->pb_flags & PBF_MAPPED)) { | |
594 | error = _pagebuf_map_pages(pb, flags); | |
595 | if (unlikely(error)) { | |
596 | printk(KERN_WARNING "%s: failed to map pages\n", | |
597 | __FUNCTION__); | |
598 | goto no_buffer; | |
599 | } | |
600 | } | |
601 | ||
602 | XFS_STATS_INC(pb_get); | |
603 | ||
604 | /* | |
605 | * Always fill in the block number now, the mapped cases can do | |
606 | * their own overlay of this later. | |
607 | */ | |
608 | pb->pb_bn = ioff; | |
609 | pb->pb_count_desired = pb->pb_buffer_length; | |
610 | ||
611 | PB_TRACE(pb, "get", (unsigned long)flags); | |
612 | return pb; | |
613 | ||
614 | no_buffer: | |
615 | if (flags & (PBF_LOCK | PBF_TRYLOCK)) | |
616 | pagebuf_unlock(pb); | |
617 | pagebuf_rele(pb); | |
618 | return NULL; | |
619 | } | |
620 | ||
621 | xfs_buf_t * | |
622 | xfs_buf_read_flags( | |
623 | xfs_buftarg_t *target, | |
624 | loff_t ioff, | |
625 | size_t isize, | |
626 | page_buf_flags_t flags) | |
627 | { | |
628 | xfs_buf_t *pb; | |
629 | ||
630 | flags |= PBF_READ; | |
631 | ||
632 | pb = xfs_buf_get_flags(target, ioff, isize, flags); | |
633 | if (pb) { | |
88741a95 | 634 | if (!XFS_BUF_ISDONE(pb)) { |
1da177e4 LT |
635 | PB_TRACE(pb, "read", (unsigned long)flags); |
636 | XFS_STATS_INC(pb_get_read); | |
637 | pagebuf_iostart(pb, flags); | |
638 | } else if (flags & PBF_ASYNC) { | |
639 | PB_TRACE(pb, "read_async", (unsigned long)flags); | |
640 | /* | |
641 | * Read ahead call which is already satisfied, | |
642 | * drop the buffer | |
643 | */ | |
644 | goto no_buffer; | |
645 | } else { | |
646 | PB_TRACE(pb, "read_done", (unsigned long)flags); | |
647 | /* We do not want read in the flags */ | |
648 | pb->pb_flags &= ~PBF_READ; | |
649 | } | |
650 | } | |
651 | ||
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 | ||
1da177e4 LT |
661 | /* |
662 | * If we are not low on memory then do the readahead in a deadlock | |
663 | * safe manner. | |
664 | */ | |
665 | void | |
666 | pagebuf_readahead( | |
667 | xfs_buftarg_t *target, | |
668 | loff_t ioff, | |
669 | size_t isize, | |
670 | page_buf_flags_t flags) | |
671 | { | |
672 | struct backing_dev_info *bdi; | |
673 | ||
674 | bdi = target->pbr_mapping->backing_dev_info; | |
675 | if (bdi_read_congested(bdi)) | |
676 | return; | |
677 | ||
678 | flags |= (PBF_TRYLOCK|PBF_ASYNC|PBF_READ_AHEAD); | |
679 | xfs_buf_read_flags(target, ioff, isize, flags); | |
680 | } | |
681 | ||
682 | xfs_buf_t * | |
683 | pagebuf_get_empty( | |
684 | size_t len, | |
685 | xfs_buftarg_t *target) | |
686 | { | |
687 | xfs_buf_t *pb; | |
688 | ||
689 | pb = pagebuf_allocate(0); | |
690 | if (pb) | |
691 | _pagebuf_initialize(pb, target, 0, len, 0); | |
692 | return pb; | |
693 | } | |
694 | ||
695 | static inline struct page * | |
696 | mem_to_page( | |
697 | void *addr) | |
698 | { | |
699 | if (((unsigned long)addr < VMALLOC_START) || | |
700 | ((unsigned long)addr >= VMALLOC_END)) { | |
701 | return virt_to_page(addr); | |
702 | } else { | |
703 | return vmalloc_to_page(addr); | |
704 | } | |
705 | } | |
706 | ||
707 | int | |
708 | pagebuf_associate_memory( | |
709 | xfs_buf_t *pb, | |
710 | void *mem, | |
711 | size_t len) | |
712 | { | |
713 | int rval; | |
714 | int i = 0; | |
715 | size_t ptr; | |
716 | size_t end, end_cur; | |
717 | off_t offset; | |
718 | int page_count; | |
719 | ||
720 | page_count = PAGE_CACHE_ALIGN(len) >> PAGE_CACHE_SHIFT; | |
721 | offset = (off_t) mem - ((off_t)mem & PAGE_CACHE_MASK); | |
722 | if (offset && (len > PAGE_CACHE_SIZE)) | |
723 | page_count++; | |
724 | ||
725 | /* Free any previous set of page pointers */ | |
726 | if (pb->pb_pages) | |
727 | _pagebuf_free_pages(pb); | |
728 | ||
729 | pb->pb_pages = NULL; | |
730 | pb->pb_addr = mem; | |
731 | ||
732 | rval = _pagebuf_get_pages(pb, page_count, 0); | |
733 | if (rval) | |
734 | return rval; | |
735 | ||
736 | pb->pb_offset = offset; | |
737 | ptr = (size_t) mem & PAGE_CACHE_MASK; | |
738 | end = PAGE_CACHE_ALIGN((size_t) mem + len); | |
739 | end_cur = end; | |
740 | /* set up first page */ | |
741 | pb->pb_pages[0] = mem_to_page(mem); | |
742 | ||
743 | ptr += PAGE_CACHE_SIZE; | |
744 | pb->pb_page_count = ++i; | |
745 | while (ptr < end) { | |
746 | pb->pb_pages[i] = mem_to_page((void *)ptr); | |
747 | pb->pb_page_count = ++i; | |
748 | ptr += PAGE_CACHE_SIZE; | |
749 | } | |
750 | pb->pb_locked = 0; | |
751 | ||
752 | pb->pb_count_desired = pb->pb_buffer_length = len; | |
753 | pb->pb_flags |= PBF_MAPPED; | |
754 | ||
755 | return 0; | |
756 | } | |
757 | ||
758 | xfs_buf_t * | |
759 | pagebuf_get_no_daddr( | |
760 | size_t len, | |
761 | xfs_buftarg_t *target) | |
762 | { | |
763 | size_t malloc_len = len; | |
764 | xfs_buf_t *bp; | |
765 | void *data; | |
766 | int error; | |
767 | ||
768 | bp = pagebuf_allocate(0); | |
769 | if (unlikely(bp == NULL)) | |
770 | goto fail; | |
88741a95 | 771 | _pagebuf_initialize(bp, target, 0, len, 0); |
1da177e4 LT |
772 | |
773 | try_again: | |
774 | data = kmem_alloc(malloc_len, KM_SLEEP | KM_MAYFAIL); | |
775 | if (unlikely(data == NULL)) | |
776 | goto fail_free_buf; | |
777 | ||
778 | /* check whether alignment matches.. */ | |
779 | if ((__psunsigned_t)data != | |
780 | ((__psunsigned_t)data & ~target->pbr_smask)) { | |
781 | /* .. else double the size and try again */ | |
782 | kmem_free(data, malloc_len); | |
783 | malloc_len <<= 1; | |
784 | goto try_again; | |
785 | } | |
786 | ||
787 | error = pagebuf_associate_memory(bp, data, len); | |
788 | if (error) | |
789 | goto fail_free_mem; | |
790 | bp->pb_flags |= _PBF_KMEM_ALLOC; | |
791 | ||
792 | pagebuf_unlock(bp); | |
793 | ||
794 | PB_TRACE(bp, "no_daddr", data); | |
795 | return bp; | |
796 | fail_free_mem: | |
797 | kmem_free(data, malloc_len); | |
798 | fail_free_buf: | |
799 | pagebuf_free(bp); | |
800 | fail: | |
801 | return NULL; | |
802 | } | |
803 | ||
804 | /* | |
805 | * pagebuf_hold | |
806 | * | |
807 | * Increment reference count on buffer, to hold the buffer concurrently | |
808 | * with another thread which may release (free) the buffer asynchronously. | |
809 | * | |
810 | * Must hold the buffer already to call this function. | |
811 | */ | |
812 | void | |
813 | pagebuf_hold( | |
814 | xfs_buf_t *pb) | |
815 | { | |
816 | atomic_inc(&pb->pb_hold); | |
817 | PB_TRACE(pb, "hold", 0); | |
818 | } | |
819 | ||
820 | /* | |
821 | * pagebuf_rele | |
822 | * | |
823 | * pagebuf_rele releases a hold on the specified buffer. If the | |
824 | * the hold count is 1, pagebuf_rele calls pagebuf_free. | |
825 | */ | |
826 | void | |
827 | pagebuf_rele( | |
828 | xfs_buf_t *pb) | |
829 | { | |
830 | xfs_bufhash_t *hash = pb->pb_hash; | |
831 | ||
832 | PB_TRACE(pb, "rele", pb->pb_relse); | |
833 | ||
1da177e4 | 834 | if (atomic_dec_and_lock(&pb->pb_hold, &hash->bh_lock)) { |
1da177e4 LT |
835 | if (pb->pb_relse) { |
836 | atomic_inc(&pb->pb_hold); | |
837 | spin_unlock(&hash->bh_lock); | |
838 | (*(pb->pb_relse)) (pb); | |
7f14d0a0 | 839 | } else if (pb->pb_flags & PBF_FS_MANAGED) { |
1da177e4 | 840 | spin_unlock(&hash->bh_lock); |
1da177e4 | 841 | } else { |
7f14d0a0 CH |
842 | ASSERT(!(pb->pb_flags & (PBF_DELWRI|_PBF_DELWRI_Q))); |
843 | list_del_init(&pb->pb_hash_list); | |
1da177e4 | 844 | spin_unlock(&hash->bh_lock); |
7f14d0a0 | 845 | pagebuf_free(pb); |
1da177e4 | 846 | } |
2f926587 DC |
847 | } else { |
848 | /* | |
849 | * Catch reference count leaks | |
850 | */ | |
851 | ASSERT(atomic_read(&pb->pb_hold) >= 0); | |
1da177e4 LT |
852 | } |
853 | } | |
854 | ||
855 | ||
856 | /* | |
857 | * Mutual exclusion on buffers. Locking model: | |
858 | * | |
859 | * Buffers associated with inodes for which buffer locking | |
860 | * is not enabled are not protected by semaphores, and are | |
861 | * assumed to be exclusively owned by the caller. There is a | |
862 | * spinlock in the buffer, used by the caller when concurrent | |
863 | * access is possible. | |
864 | */ | |
865 | ||
866 | /* | |
867 | * pagebuf_cond_lock | |
868 | * | |
869 | * pagebuf_cond_lock locks a buffer object, if it is not already locked. | |
870 | * Note that this in no way | |
871 | * locks the underlying pages, so it is only useful for synchronizing | |
872 | * concurrent use of page buffer objects, not for synchronizing independent | |
873 | * access to the underlying pages. | |
874 | */ | |
875 | int | |
876 | pagebuf_cond_lock( /* lock buffer, if not locked */ | |
877 | /* returns -EBUSY if locked) */ | |
878 | xfs_buf_t *pb) | |
879 | { | |
880 | int locked; | |
881 | ||
882 | locked = down_trylock(&pb->pb_sema) == 0; | |
883 | if (locked) { | |
884 | PB_SET_OWNER(pb); | |
885 | } | |
886 | PB_TRACE(pb, "cond_lock", (long)locked); | |
887 | return(locked ? 0 : -EBUSY); | |
888 | } | |
889 | ||
890 | #if defined(DEBUG) || defined(XFS_BLI_TRACE) | |
891 | /* | |
892 | * pagebuf_lock_value | |
893 | * | |
894 | * Return lock value for a pagebuf | |
895 | */ | |
896 | int | |
897 | pagebuf_lock_value( | |
898 | xfs_buf_t *pb) | |
899 | { | |
900 | return(atomic_read(&pb->pb_sema.count)); | |
901 | } | |
902 | #endif | |
903 | ||
904 | /* | |
905 | * pagebuf_lock | |
906 | * | |
907 | * pagebuf_lock locks a buffer object. Note that this in no way | |
908 | * locks the underlying pages, so it is only useful for synchronizing | |
909 | * concurrent use of page buffer objects, not for synchronizing independent | |
910 | * access to the underlying pages. | |
911 | */ | |
912 | int | |
913 | pagebuf_lock( | |
914 | xfs_buf_t *pb) | |
915 | { | |
916 | PB_TRACE(pb, "lock", 0); | |
917 | if (atomic_read(&pb->pb_io_remaining)) | |
918 | blk_run_address_space(pb->pb_target->pbr_mapping); | |
919 | down(&pb->pb_sema); | |
920 | PB_SET_OWNER(pb); | |
921 | PB_TRACE(pb, "locked", 0); | |
922 | return 0; | |
923 | } | |
924 | ||
925 | /* | |
926 | * pagebuf_unlock | |
927 | * | |
928 | * pagebuf_unlock releases the lock on the buffer object created by | |
2f926587 DC |
929 | * pagebuf_lock or pagebuf_cond_lock (not any pinning of underlying pages |
930 | * created by pagebuf_pin). | |
931 | * | |
932 | * If the buffer is marked delwri but is not queued, do so before we | |
933 | * unlock the buffer as we need to set flags correctly. We also need to | |
934 | * take a reference for the delwri queue because the unlocker is going to | |
935 | * drop their's and they don't know we just queued it. | |
1da177e4 LT |
936 | */ |
937 | void | |
938 | pagebuf_unlock( /* unlock buffer */ | |
939 | xfs_buf_t *pb) /* buffer to unlock */ | |
940 | { | |
2f926587 DC |
941 | if ((pb->pb_flags & (PBF_DELWRI|_PBF_DELWRI_Q)) == PBF_DELWRI) { |
942 | atomic_inc(&pb->pb_hold); | |
943 | pb->pb_flags |= PBF_ASYNC; | |
944 | pagebuf_delwri_queue(pb, 0); | |
945 | } | |
946 | ||
1da177e4 LT |
947 | PB_CLEAR_OWNER(pb); |
948 | up(&pb->pb_sema); | |
949 | PB_TRACE(pb, "unlock", 0); | |
950 | } | |
951 | ||
952 | ||
953 | /* | |
954 | * Pinning Buffer Storage in Memory | |
955 | */ | |
956 | ||
957 | /* | |
958 | * pagebuf_pin | |
959 | * | |
960 | * pagebuf_pin locks all of the memory represented by a buffer in | |
961 | * memory. Multiple calls to pagebuf_pin and pagebuf_unpin, for | |
962 | * the same or different buffers affecting a given page, will | |
963 | * properly count the number of outstanding "pin" requests. The | |
964 | * buffer may be released after the pagebuf_pin and a different | |
965 | * buffer used when calling pagebuf_unpin, if desired. | |
966 | * pagebuf_pin should be used by the file system when it wants be | |
967 | * assured that no attempt will be made to force the affected | |
968 | * memory to disk. It does not assure that a given logical page | |
969 | * will not be moved to a different physical page. | |
970 | */ | |
971 | void | |
972 | pagebuf_pin( | |
973 | xfs_buf_t *pb) | |
974 | { | |
975 | atomic_inc(&pb->pb_pin_count); | |
976 | PB_TRACE(pb, "pin", (long)pb->pb_pin_count.counter); | |
977 | } | |
978 | ||
979 | /* | |
980 | * pagebuf_unpin | |
981 | * | |
982 | * pagebuf_unpin reverses the locking of memory performed by | |
983 | * pagebuf_pin. Note that both functions affected the logical | |
984 | * pages associated with the buffer, not the buffer itself. | |
985 | */ | |
986 | void | |
987 | pagebuf_unpin( | |
988 | xfs_buf_t *pb) | |
989 | { | |
990 | if (atomic_dec_and_test(&pb->pb_pin_count)) { | |
991 | wake_up_all(&pb->pb_waiters); | |
992 | } | |
993 | PB_TRACE(pb, "unpin", (long)pb->pb_pin_count.counter); | |
994 | } | |
995 | ||
996 | int | |
997 | pagebuf_ispin( | |
998 | xfs_buf_t *pb) | |
999 | { | |
1000 | return atomic_read(&pb->pb_pin_count); | |
1001 | } | |
1002 | ||
1003 | /* | |
1004 | * pagebuf_wait_unpin | |
1005 | * | |
1006 | * pagebuf_wait_unpin waits until all of the memory associated | |
1007 | * with the buffer is not longer locked in memory. It returns | |
1008 | * immediately if none of the affected pages are locked. | |
1009 | */ | |
1010 | static inline void | |
1011 | _pagebuf_wait_unpin( | |
1012 | xfs_buf_t *pb) | |
1013 | { | |
1014 | DECLARE_WAITQUEUE (wait, current); | |
1015 | ||
1016 | if (atomic_read(&pb->pb_pin_count) == 0) | |
1017 | return; | |
1018 | ||
1019 | add_wait_queue(&pb->pb_waiters, &wait); | |
1020 | for (;;) { | |
1021 | set_current_state(TASK_UNINTERRUPTIBLE); | |
1022 | if (atomic_read(&pb->pb_pin_count) == 0) | |
1023 | break; | |
1024 | if (atomic_read(&pb->pb_io_remaining)) | |
1025 | blk_run_address_space(pb->pb_target->pbr_mapping); | |
1026 | schedule(); | |
1027 | } | |
1028 | remove_wait_queue(&pb->pb_waiters, &wait); | |
1029 | set_current_state(TASK_RUNNING); | |
1030 | } | |
1031 | ||
1032 | /* | |
1033 | * Buffer Utility Routines | |
1034 | */ | |
1035 | ||
1036 | /* | |
1037 | * pagebuf_iodone | |
1038 | * | |
1039 | * pagebuf_iodone marks a buffer for which I/O is in progress | |
1040 | * done with respect to that I/O. The pb_iodone routine, if | |
1041 | * present, will be called as a side-effect. | |
1042 | */ | |
1043 | STATIC void | |
1044 | pagebuf_iodone_work( | |
1045 | void *v) | |
1046 | { | |
1047 | xfs_buf_t *bp = (xfs_buf_t *)v; | |
1048 | ||
1049 | if (bp->pb_iodone) | |
1050 | (*(bp->pb_iodone))(bp); | |
1051 | else if (bp->pb_flags & PBF_ASYNC) | |
1052 | xfs_buf_relse(bp); | |
1053 | } | |
1054 | ||
1055 | void | |
1056 | pagebuf_iodone( | |
1057 | xfs_buf_t *pb, | |
1da177e4 LT |
1058 | int schedule) |
1059 | { | |
1060 | pb->pb_flags &= ~(PBF_READ | PBF_WRITE); | |
88741a95 | 1061 | if (pb->pb_error == 0) |
c86e711c | 1062 | pb->pb_flags |= PBF_DONE; |
1da177e4 LT |
1063 | |
1064 | PB_TRACE(pb, "iodone", pb->pb_iodone); | |
1065 | ||
1066 | if ((pb->pb_iodone) || (pb->pb_flags & PBF_ASYNC)) { | |
1067 | if (schedule) { | |
1068 | INIT_WORK(&pb->pb_iodone_work, pagebuf_iodone_work, pb); | |
88741a95 | 1069 | queue_work(xfslogd_workqueue, &pb->pb_iodone_work); |
1da177e4 LT |
1070 | } else { |
1071 | pagebuf_iodone_work(pb); | |
1072 | } | |
1073 | } else { | |
1074 | up(&pb->pb_iodonesema); | |
1075 | } | |
1076 | } | |
1077 | ||
1078 | /* | |
1079 | * pagebuf_ioerror | |
1080 | * | |
1081 | * pagebuf_ioerror sets the error code for a buffer. | |
1082 | */ | |
1083 | void | |
1084 | pagebuf_ioerror( /* mark/clear buffer error flag */ | |
1085 | xfs_buf_t *pb, /* buffer to mark */ | |
1086 | int error) /* error to store (0 if none) */ | |
1087 | { | |
1088 | ASSERT(error >= 0 && error <= 0xffff); | |
1089 | pb->pb_error = (unsigned short)error; | |
1090 | PB_TRACE(pb, "ioerror", (unsigned long)error); | |
1091 | } | |
1092 | ||
1093 | /* | |
1094 | * pagebuf_iostart | |
1095 | * | |
1096 | * pagebuf_iostart initiates I/O on a buffer, based on the flags supplied. | |
1097 | * If necessary, it will arrange for any disk space allocation required, | |
1098 | * and it will break up the request if the block mappings require it. | |
1099 | * The pb_iodone routine in the buffer supplied will only be called | |
1100 | * when all of the subsidiary I/O requests, if any, have been completed. | |
1101 | * pagebuf_iostart calls the pagebuf_ioinitiate routine or | |
1102 | * pagebuf_iorequest, if the former routine is not defined, to start | |
1103 | * the I/O on a given low-level request. | |
1104 | */ | |
1105 | int | |
1106 | pagebuf_iostart( /* start I/O on a buffer */ | |
1107 | xfs_buf_t *pb, /* buffer to start */ | |
1108 | page_buf_flags_t flags) /* PBF_LOCK, PBF_ASYNC, PBF_READ, */ | |
1109 | /* PBF_WRITE, PBF_DELWRI, */ | |
1110 | /* PBF_DONT_BLOCK */ | |
1111 | { | |
1112 | int status = 0; | |
1113 | ||
1114 | PB_TRACE(pb, "iostart", (unsigned long)flags); | |
1115 | ||
1116 | if (flags & PBF_DELWRI) { | |
1117 | pb->pb_flags &= ~(PBF_READ | PBF_WRITE | PBF_ASYNC); | |
1118 | pb->pb_flags |= flags & (PBF_DELWRI | PBF_ASYNC); | |
1119 | pagebuf_delwri_queue(pb, 1); | |
1120 | return status; | |
1121 | } | |
1122 | ||
1123 | pb->pb_flags &= ~(PBF_READ | PBF_WRITE | PBF_ASYNC | PBF_DELWRI | \ | |
1124 | PBF_READ_AHEAD | _PBF_RUN_QUEUES); | |
1125 | pb->pb_flags |= flags & (PBF_READ | PBF_WRITE | PBF_ASYNC | \ | |
1126 | PBF_READ_AHEAD | _PBF_RUN_QUEUES); | |
1127 | ||
1128 | BUG_ON(pb->pb_bn == XFS_BUF_DADDR_NULL); | |
1129 | ||
1130 | /* For writes allow an alternate strategy routine to precede | |
1131 | * the actual I/O request (which may not be issued at all in | |
1132 | * a shutdown situation, for example). | |
1133 | */ | |
1134 | status = (flags & PBF_WRITE) ? | |
1135 | pagebuf_iostrategy(pb) : pagebuf_iorequest(pb); | |
1136 | ||
1137 | /* Wait for I/O if we are not an async request. | |
1138 | * Note: async I/O request completion will release the buffer, | |
1139 | * and that can already be done by this point. So using the | |
1140 | * buffer pointer from here on, after async I/O, is invalid. | |
1141 | */ | |
1142 | if (!status && !(flags & PBF_ASYNC)) | |
1143 | status = pagebuf_iowait(pb); | |
1144 | ||
1145 | return status; | |
1146 | } | |
1147 | ||
1148 | /* | |
1149 | * Helper routine for pagebuf_iorequest | |
1150 | */ | |
1151 | ||
1152 | STATIC __inline__ int | |
1153 | _pagebuf_iolocked( | |
1154 | xfs_buf_t *pb) | |
1155 | { | |
1156 | ASSERT(pb->pb_flags & (PBF_READ|PBF_WRITE)); | |
1157 | if (pb->pb_flags & PBF_READ) | |
1158 | return pb->pb_locked; | |
1159 | return 0; | |
1160 | } | |
1161 | ||
1162 | STATIC __inline__ void | |
1163 | _pagebuf_iodone( | |
1164 | xfs_buf_t *pb, | |
1165 | int schedule) | |
1166 | { | |
1167 | if (atomic_dec_and_test(&pb->pb_io_remaining) == 1) { | |
1168 | pb->pb_locked = 0; | |
88741a95 | 1169 | pagebuf_iodone(pb, schedule); |
1da177e4 LT |
1170 | } |
1171 | } | |
1172 | ||
1173 | STATIC int | |
1174 | bio_end_io_pagebuf( | |
1175 | struct bio *bio, | |
1176 | unsigned int bytes_done, | |
1177 | int error) | |
1178 | { | |
1179 | xfs_buf_t *pb = (xfs_buf_t *)bio->bi_private; | |
eedb5530 NS |
1180 | unsigned int blocksize = pb->pb_target->pbr_bsize; |
1181 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; | |
1da177e4 LT |
1182 | |
1183 | if (bio->bi_size) | |
1184 | return 1; | |
1185 | ||
1186 | if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) | |
1187 | pb->pb_error = EIO; | |
1188 | ||
eedb5530 | 1189 | do { |
1da177e4 LT |
1190 | struct page *page = bvec->bv_page; |
1191 | ||
eedb5530 NS |
1192 | if (unlikely(pb->pb_error)) { |
1193 | if (pb->pb_flags & PBF_READ) | |
1194 | ClearPageUptodate(page); | |
1da177e4 LT |
1195 | SetPageError(page); |
1196 | } else if (blocksize == PAGE_CACHE_SIZE) { | |
1197 | SetPageUptodate(page); | |
1198 | } else if (!PagePrivate(page) && | |
1199 | (pb->pb_flags & _PBF_PAGE_CACHE)) { | |
1200 | set_page_region(page, bvec->bv_offset, bvec->bv_len); | |
1201 | } | |
1202 | ||
eedb5530 NS |
1203 | if (--bvec >= bio->bi_io_vec) |
1204 | prefetchw(&bvec->bv_page->flags); | |
1205 | ||
1da177e4 LT |
1206 | if (_pagebuf_iolocked(pb)) { |
1207 | unlock_page(page); | |
1208 | } | |
eedb5530 | 1209 | } while (bvec >= bio->bi_io_vec); |
1da177e4 LT |
1210 | |
1211 | _pagebuf_iodone(pb, 1); | |
1212 | bio_put(bio); | |
1213 | return 0; | |
1214 | } | |
1215 | ||
1216 | STATIC void | |
1217 | _pagebuf_ioapply( | |
1218 | xfs_buf_t *pb) | |
1219 | { | |
1220 | int i, rw, map_i, total_nr_pages, nr_pages; | |
1221 | struct bio *bio; | |
1222 | int offset = pb->pb_offset; | |
1223 | int size = pb->pb_count_desired; | |
1224 | sector_t sector = pb->pb_bn; | |
1225 | unsigned int blocksize = pb->pb_target->pbr_bsize; | |
1226 | int locking = _pagebuf_iolocked(pb); | |
1227 | ||
1228 | total_nr_pages = pb->pb_page_count; | |
1229 | map_i = 0; | |
1230 | ||
1231 | if (pb->pb_flags & _PBF_RUN_QUEUES) { | |
1232 | pb->pb_flags &= ~_PBF_RUN_QUEUES; | |
1233 | rw = (pb->pb_flags & PBF_READ) ? READ_SYNC : WRITE_SYNC; | |
1234 | } else { | |
1235 | rw = (pb->pb_flags & PBF_READ) ? READ : WRITE; | |
1236 | } | |
1237 | ||
f538d4da CH |
1238 | if (pb->pb_flags & PBF_ORDERED) { |
1239 | ASSERT(!(pb->pb_flags & PBF_READ)); | |
1240 | rw = WRITE_BARRIER; | |
1241 | } | |
1242 | ||
1da177e4 LT |
1243 | /* Special code path for reading a sub page size pagebuf in -- |
1244 | * we populate up the whole page, and hence the other metadata | |
1245 | * in the same page. This optimization is only valid when the | |
1246 | * filesystem block size and the page size are equal. | |
1247 | */ | |
1248 | if ((pb->pb_buffer_length < PAGE_CACHE_SIZE) && | |
1249 | (pb->pb_flags & PBF_READ) && locking && | |
1250 | (blocksize == PAGE_CACHE_SIZE)) { | |
1251 | bio = bio_alloc(GFP_NOIO, 1); | |
1252 | ||
1253 | bio->bi_bdev = pb->pb_target->pbr_bdev; | |
1254 | bio->bi_sector = sector - (offset >> BBSHIFT); | |
1255 | bio->bi_end_io = bio_end_io_pagebuf; | |
1256 | bio->bi_private = pb; | |
1257 | ||
1258 | bio_add_page(bio, pb->pb_pages[0], PAGE_CACHE_SIZE, 0); | |
1259 | size = 0; | |
1260 | ||
1261 | atomic_inc(&pb->pb_io_remaining); | |
1262 | ||
1263 | goto submit_io; | |
1264 | } | |
1265 | ||
1266 | /* Lock down the pages which we need to for the request */ | |
1267 | if (locking && (pb->pb_flags & PBF_WRITE) && (pb->pb_locked == 0)) { | |
1268 | for (i = 0; size; i++) { | |
1269 | int nbytes = PAGE_CACHE_SIZE - offset; | |
1270 | struct page *page = pb->pb_pages[i]; | |
1271 | ||
1272 | if (nbytes > size) | |
1273 | nbytes = size; | |
1274 | ||
1275 | lock_page(page); | |
1276 | ||
1277 | size -= nbytes; | |
1278 | offset = 0; | |
1279 | } | |
1280 | offset = pb->pb_offset; | |
1281 | size = pb->pb_count_desired; | |
1282 | } | |
1283 | ||
1284 | next_chunk: | |
1285 | atomic_inc(&pb->pb_io_remaining); | |
1286 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); | |
1287 | if (nr_pages > total_nr_pages) | |
1288 | nr_pages = total_nr_pages; | |
1289 | ||
1290 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
1291 | bio->bi_bdev = pb->pb_target->pbr_bdev; | |
1292 | bio->bi_sector = sector; | |
1293 | bio->bi_end_io = bio_end_io_pagebuf; | |
1294 | bio->bi_private = pb; | |
1295 | ||
1296 | for (; size && nr_pages; nr_pages--, map_i++) { | |
1297 | int nbytes = PAGE_CACHE_SIZE - offset; | |
1298 | ||
1299 | if (nbytes > size) | |
1300 | nbytes = size; | |
1301 | ||
1302 | if (bio_add_page(bio, pb->pb_pages[map_i], | |
1303 | nbytes, offset) < nbytes) | |
1304 | break; | |
1305 | ||
1306 | offset = 0; | |
1307 | sector += nbytes >> BBSHIFT; | |
1308 | size -= nbytes; | |
1309 | total_nr_pages--; | |
1310 | } | |
1311 | ||
1312 | submit_io: | |
1313 | if (likely(bio->bi_size)) { | |
1314 | submit_bio(rw, bio); | |
1315 | if (size) | |
1316 | goto next_chunk; | |
1317 | } else { | |
1318 | bio_put(bio); | |
1319 | pagebuf_ioerror(pb, EIO); | |
1320 | } | |
1321 | } | |
1322 | ||
1323 | /* | |
1324 | * pagebuf_iorequest -- the core I/O request routine. | |
1325 | */ | |
1326 | int | |
1327 | pagebuf_iorequest( /* start real I/O */ | |
1328 | xfs_buf_t *pb) /* buffer to convey to device */ | |
1329 | { | |
1330 | PB_TRACE(pb, "iorequest", 0); | |
1331 | ||
1332 | if (pb->pb_flags & PBF_DELWRI) { | |
1333 | pagebuf_delwri_queue(pb, 1); | |
1334 | return 0; | |
1335 | } | |
1336 | ||
1337 | if (pb->pb_flags & PBF_WRITE) { | |
1338 | _pagebuf_wait_unpin(pb); | |
1339 | } | |
1340 | ||
1341 | pagebuf_hold(pb); | |
1342 | ||
1343 | /* Set the count to 1 initially, this will stop an I/O | |
1344 | * completion callout which happens before we have started | |
1345 | * all the I/O from calling pagebuf_iodone too early. | |
1346 | */ | |
1347 | atomic_set(&pb->pb_io_remaining, 1); | |
1348 | _pagebuf_ioapply(pb); | |
1349 | _pagebuf_iodone(pb, 0); | |
1350 | ||
1351 | pagebuf_rele(pb); | |
1352 | return 0; | |
1353 | } | |
1354 | ||
1355 | /* | |
1356 | * pagebuf_iowait | |
1357 | * | |
1358 | * pagebuf_iowait waits for I/O to complete on the buffer supplied. | |
1359 | * It returns immediately if no I/O is pending. In any case, it returns | |
1360 | * the error code, if any, or 0 if there is no error. | |
1361 | */ | |
1362 | int | |
1363 | pagebuf_iowait( | |
1364 | xfs_buf_t *pb) | |
1365 | { | |
1366 | PB_TRACE(pb, "iowait", 0); | |
1367 | if (atomic_read(&pb->pb_io_remaining)) | |
1368 | blk_run_address_space(pb->pb_target->pbr_mapping); | |
1369 | down(&pb->pb_iodonesema); | |
1370 | PB_TRACE(pb, "iowaited", (long)pb->pb_error); | |
1371 | return pb->pb_error; | |
1372 | } | |
1373 | ||
1374 | caddr_t | |
1375 | pagebuf_offset( | |
1376 | xfs_buf_t *pb, | |
1377 | size_t offset) | |
1378 | { | |
1379 | struct page *page; | |
1380 | ||
1381 | offset += pb->pb_offset; | |
1382 | ||
1383 | page = pb->pb_pages[offset >> PAGE_CACHE_SHIFT]; | |
1384 | return (caddr_t) page_address(page) + (offset & (PAGE_CACHE_SIZE - 1)); | |
1385 | } | |
1386 | ||
1387 | /* | |
1388 | * pagebuf_iomove | |
1389 | * | |
1390 | * Move data into or out of a buffer. | |
1391 | */ | |
1392 | void | |
1393 | pagebuf_iomove( | |
1394 | xfs_buf_t *pb, /* buffer to process */ | |
1395 | size_t boff, /* starting buffer offset */ | |
1396 | size_t bsize, /* length to copy */ | |
1397 | caddr_t data, /* data address */ | |
1398 | page_buf_rw_t mode) /* read/write flag */ | |
1399 | { | |
1400 | size_t bend, cpoff, csize; | |
1401 | struct page *page; | |
1402 | ||
1403 | bend = boff + bsize; | |
1404 | while (boff < bend) { | |
1405 | page = pb->pb_pages[page_buf_btoct(boff + pb->pb_offset)]; | |
1406 | cpoff = page_buf_poff(boff + pb->pb_offset); | |
1407 | csize = min_t(size_t, | |
1408 | PAGE_CACHE_SIZE-cpoff, pb->pb_count_desired-boff); | |
1409 | ||
1410 | ASSERT(((csize + cpoff) <= PAGE_CACHE_SIZE)); | |
1411 | ||
1412 | switch (mode) { | |
1413 | case PBRW_ZERO: | |
1414 | memset(page_address(page) + cpoff, 0, csize); | |
1415 | break; | |
1416 | case PBRW_READ: | |
1417 | memcpy(data, page_address(page) + cpoff, csize); | |
1418 | break; | |
1419 | case PBRW_WRITE: | |
1420 | memcpy(page_address(page) + cpoff, data, csize); | |
1421 | } | |
1422 | ||
1423 | boff += csize; | |
1424 | data += csize; | |
1425 | } | |
1426 | } | |
1427 | ||
1428 | /* | |
1429 | * Handling of buftargs. | |
1430 | */ | |
1431 | ||
1432 | /* | |
1433 | * Wait for any bufs with callbacks that have been submitted but | |
1434 | * have not yet returned... walk the hash list for the target. | |
1435 | */ | |
1436 | void | |
1437 | xfs_wait_buftarg( | |
1438 | xfs_buftarg_t *btp) | |
1439 | { | |
1440 | xfs_buf_t *bp, *n; | |
1441 | xfs_bufhash_t *hash; | |
1442 | uint i; | |
1443 | ||
1444 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { | |
1445 | hash = &btp->bt_hash[i]; | |
1446 | again: | |
1447 | spin_lock(&hash->bh_lock); | |
1448 | list_for_each_entry_safe(bp, n, &hash->bh_list, pb_hash_list) { | |
1449 | ASSERT(btp == bp->pb_target); | |
1450 | if (!(bp->pb_flags & PBF_FS_MANAGED)) { | |
1451 | spin_unlock(&hash->bh_lock); | |
2f926587 DC |
1452 | /* |
1453 | * Catch superblock reference count leaks | |
1454 | * immediately | |
1455 | */ | |
1456 | BUG_ON(bp->pb_bn == 0); | |
1da177e4 LT |
1457 | delay(100); |
1458 | goto again; | |
1459 | } | |
1460 | } | |
1461 | spin_unlock(&hash->bh_lock); | |
1462 | } | |
1463 | } | |
1464 | ||
1465 | /* | |
1466 | * Allocate buffer hash table for a given target. | |
1467 | * For devices containing metadata (i.e. not the log/realtime devices) | |
1468 | * we need to allocate a much larger hash table. | |
1469 | */ | |
1470 | STATIC void | |
1471 | xfs_alloc_bufhash( | |
1472 | xfs_buftarg_t *btp, | |
1473 | int external) | |
1474 | { | |
1475 | unsigned int i; | |
1476 | ||
1477 | btp->bt_hashshift = external ? 3 : 8; /* 8 or 256 buckets */ | |
1478 | btp->bt_hashmask = (1 << btp->bt_hashshift) - 1; | |
1479 | btp->bt_hash = kmem_zalloc((1 << btp->bt_hashshift) * | |
1480 | sizeof(xfs_bufhash_t), KM_SLEEP); | |
1481 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { | |
1482 | spin_lock_init(&btp->bt_hash[i].bh_lock); | |
1483 | INIT_LIST_HEAD(&btp->bt_hash[i].bh_list); | |
1484 | } | |
1485 | } | |
1486 | ||
1487 | STATIC void | |
1488 | xfs_free_bufhash( | |
1489 | xfs_buftarg_t *btp) | |
1490 | { | |
1491 | kmem_free(btp->bt_hash, | |
1492 | (1 << btp->bt_hashshift) * sizeof(xfs_bufhash_t)); | |
1493 | btp->bt_hash = NULL; | |
1494 | } | |
1495 | ||
a6867a68 DC |
1496 | /* |
1497 | * buftarg list for delwrite queue processing | |
1498 | */ | |
1499 | STATIC LIST_HEAD(xfs_buftarg_list); | |
1500 | STATIC DEFINE_SPINLOCK(xfs_buftarg_lock); | |
1501 | ||
1502 | STATIC void | |
1503 | xfs_register_buftarg( | |
1504 | xfs_buftarg_t *btp) | |
1505 | { | |
1506 | spin_lock(&xfs_buftarg_lock); | |
1507 | list_add(&btp->bt_list, &xfs_buftarg_list); | |
1508 | spin_unlock(&xfs_buftarg_lock); | |
1509 | } | |
1510 | ||
1511 | STATIC void | |
1512 | xfs_unregister_buftarg( | |
1513 | xfs_buftarg_t *btp) | |
1514 | { | |
1515 | spin_lock(&xfs_buftarg_lock); | |
1516 | list_del(&btp->bt_list); | |
1517 | spin_unlock(&xfs_buftarg_lock); | |
1518 | } | |
1519 | ||
1da177e4 LT |
1520 | void |
1521 | xfs_free_buftarg( | |
1522 | xfs_buftarg_t *btp, | |
1523 | int external) | |
1524 | { | |
1525 | xfs_flush_buftarg(btp, 1); | |
1526 | if (external) | |
1527 | xfs_blkdev_put(btp->pbr_bdev); | |
1528 | xfs_free_bufhash(btp); | |
1529 | iput(btp->pbr_mapping->host); | |
a6867a68 DC |
1530 | |
1531 | /* unregister the buftarg first so that we don't get a | |
1532 | * wakeup finding a non-existent task */ | |
1533 | xfs_unregister_buftarg(btp); | |
1534 | kthread_stop(btp->bt_task); | |
1535 | ||
1da177e4 LT |
1536 | kmem_free(btp, sizeof(*btp)); |
1537 | } | |
1538 | ||
1da177e4 LT |
1539 | STATIC int |
1540 | xfs_setsize_buftarg_flags( | |
1541 | xfs_buftarg_t *btp, | |
1542 | unsigned int blocksize, | |
1543 | unsigned int sectorsize, | |
1544 | int verbose) | |
1545 | { | |
1546 | btp->pbr_bsize = blocksize; | |
1547 | btp->pbr_sshift = ffs(sectorsize) - 1; | |
1548 | btp->pbr_smask = sectorsize - 1; | |
1549 | ||
1550 | if (set_blocksize(btp->pbr_bdev, sectorsize)) { | |
1551 | printk(KERN_WARNING | |
1552 | "XFS: Cannot set_blocksize to %u on device %s\n", | |
1553 | sectorsize, XFS_BUFTARG_NAME(btp)); | |
1554 | return EINVAL; | |
1555 | } | |
1556 | ||
1557 | if (verbose && | |
1558 | (PAGE_CACHE_SIZE / BITS_PER_LONG) > sectorsize) { | |
1559 | printk(KERN_WARNING | |
1560 | "XFS: %u byte sectors in use on device %s. " | |
1561 | "This is suboptimal; %u or greater is ideal.\n", | |
1562 | sectorsize, XFS_BUFTARG_NAME(btp), | |
1563 | (unsigned int)PAGE_CACHE_SIZE / BITS_PER_LONG); | |
1564 | } | |
1565 | ||
1566 | return 0; | |
1567 | } | |
1568 | ||
1569 | /* | |
1570 | * When allocating the initial buffer target we have not yet | |
1571 | * read in the superblock, so don't know what sized sectors | |
1572 | * are being used is at this early stage. Play safe. | |
1573 | */ | |
1574 | STATIC int | |
1575 | xfs_setsize_buftarg_early( | |
1576 | xfs_buftarg_t *btp, | |
1577 | struct block_device *bdev) | |
1578 | { | |
1579 | return xfs_setsize_buftarg_flags(btp, | |
1580 | PAGE_CACHE_SIZE, bdev_hardsect_size(bdev), 0); | |
1581 | } | |
1582 | ||
1583 | int | |
1584 | xfs_setsize_buftarg( | |
1585 | xfs_buftarg_t *btp, | |
1586 | unsigned int blocksize, | |
1587 | unsigned int sectorsize) | |
1588 | { | |
1589 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | |
1590 | } | |
1591 | ||
1592 | STATIC int | |
1593 | xfs_mapping_buftarg( | |
1594 | xfs_buftarg_t *btp, | |
1595 | struct block_device *bdev) | |
1596 | { | |
1597 | struct backing_dev_info *bdi; | |
1598 | struct inode *inode; | |
1599 | struct address_space *mapping; | |
1600 | static struct address_space_operations mapping_aops = { | |
1601 | .sync_page = block_sync_page, | |
1602 | }; | |
1603 | ||
1604 | inode = new_inode(bdev->bd_inode->i_sb); | |
1605 | if (!inode) { | |
1606 | printk(KERN_WARNING | |
1607 | "XFS: Cannot allocate mapping inode for device %s\n", | |
1608 | XFS_BUFTARG_NAME(btp)); | |
1609 | return ENOMEM; | |
1610 | } | |
1611 | inode->i_mode = S_IFBLK; | |
1612 | inode->i_bdev = bdev; | |
1613 | inode->i_rdev = bdev->bd_dev; | |
1614 | bdi = blk_get_backing_dev_info(bdev); | |
1615 | if (!bdi) | |
1616 | bdi = &default_backing_dev_info; | |
1617 | mapping = &inode->i_data; | |
1618 | mapping->a_ops = &mapping_aops; | |
1619 | mapping->backing_dev_info = bdi; | |
1620 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
1621 | btp->pbr_mapping = mapping; | |
1622 | return 0; | |
1623 | } | |
1624 | ||
a6867a68 DC |
1625 | STATIC int |
1626 | xfs_alloc_delwrite_queue( | |
1627 | xfs_buftarg_t *btp) | |
1628 | { | |
1629 | int error = 0; | |
1630 | ||
1631 | INIT_LIST_HEAD(&btp->bt_list); | |
1632 | INIT_LIST_HEAD(&btp->bt_delwrite_queue); | |
1633 | spinlock_init(&btp->bt_delwrite_lock, "delwri_lock"); | |
1634 | btp->bt_flags = 0; | |
1635 | btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd"); | |
1636 | if (IS_ERR(btp->bt_task)) { | |
1637 | error = PTR_ERR(btp->bt_task); | |
1638 | goto out_error; | |
1639 | } | |
1640 | xfs_register_buftarg(btp); | |
1641 | out_error: | |
1642 | return error; | |
1643 | } | |
1644 | ||
1da177e4 LT |
1645 | xfs_buftarg_t * |
1646 | xfs_alloc_buftarg( | |
1647 | struct block_device *bdev, | |
1648 | int external) | |
1649 | { | |
1650 | xfs_buftarg_t *btp; | |
1651 | ||
1652 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP); | |
1653 | ||
1654 | btp->pbr_dev = bdev->bd_dev; | |
1655 | btp->pbr_bdev = bdev; | |
1656 | if (xfs_setsize_buftarg_early(btp, bdev)) | |
1657 | goto error; | |
1658 | if (xfs_mapping_buftarg(btp, bdev)) | |
1659 | goto error; | |
a6867a68 DC |
1660 | if (xfs_alloc_delwrite_queue(btp)) |
1661 | goto error; | |
1da177e4 LT |
1662 | xfs_alloc_bufhash(btp, external); |
1663 | return btp; | |
1664 | ||
1665 | error: | |
1666 | kmem_free(btp, sizeof(*btp)); | |
1667 | return NULL; | |
1668 | } | |
1669 | ||
1670 | ||
1671 | /* | |
1672 | * Pagebuf delayed write buffer handling | |
1673 | */ | |
1da177e4 LT |
1674 | STATIC void |
1675 | pagebuf_delwri_queue( | |
1676 | xfs_buf_t *pb, | |
1677 | int unlock) | |
1678 | { | |
a6867a68 DC |
1679 | struct list_head *dwq = &pb->pb_target->bt_delwrite_queue; |
1680 | spinlock_t *dwlk = &pb->pb_target->bt_delwrite_lock; | |
1681 | ||
1da177e4 | 1682 | PB_TRACE(pb, "delwri_q", (long)unlock); |
2f926587 DC |
1683 | ASSERT((pb->pb_flags & (PBF_DELWRI|PBF_ASYNC)) == |
1684 | (PBF_DELWRI|PBF_ASYNC)); | |
1da177e4 | 1685 | |
a6867a68 | 1686 | spin_lock(dwlk); |
1da177e4 LT |
1687 | /* If already in the queue, dequeue and place at tail */ |
1688 | if (!list_empty(&pb->pb_list)) { | |
2f926587 | 1689 | ASSERT(pb->pb_flags & _PBF_DELWRI_Q); |
1da177e4 LT |
1690 | if (unlock) { |
1691 | atomic_dec(&pb->pb_hold); | |
1692 | } | |
1693 | list_del(&pb->pb_list); | |
1694 | } | |
1695 | ||
2f926587 | 1696 | pb->pb_flags |= _PBF_DELWRI_Q; |
a6867a68 | 1697 | list_add_tail(&pb->pb_list, dwq); |
1da177e4 | 1698 | pb->pb_queuetime = jiffies; |
a6867a68 | 1699 | spin_unlock(dwlk); |
1da177e4 LT |
1700 | |
1701 | if (unlock) | |
1702 | pagebuf_unlock(pb); | |
1703 | } | |
1704 | ||
1705 | void | |
1706 | pagebuf_delwri_dequeue( | |
1707 | xfs_buf_t *pb) | |
1708 | { | |
a6867a68 | 1709 | spinlock_t *dwlk = &pb->pb_target->bt_delwrite_lock; |
1da177e4 LT |
1710 | int dequeued = 0; |
1711 | ||
a6867a68 | 1712 | spin_lock(dwlk); |
1da177e4 | 1713 | if ((pb->pb_flags & PBF_DELWRI) && !list_empty(&pb->pb_list)) { |
2f926587 | 1714 | ASSERT(pb->pb_flags & _PBF_DELWRI_Q); |
1da177e4 LT |
1715 | list_del_init(&pb->pb_list); |
1716 | dequeued = 1; | |
1717 | } | |
2f926587 | 1718 | pb->pb_flags &= ~(PBF_DELWRI|_PBF_DELWRI_Q); |
a6867a68 | 1719 | spin_unlock(dwlk); |
1da177e4 LT |
1720 | |
1721 | if (dequeued) | |
1722 | pagebuf_rele(pb); | |
1723 | ||
1724 | PB_TRACE(pb, "delwri_dq", (long)dequeued); | |
1725 | } | |
1726 | ||
1727 | STATIC void | |
1728 | pagebuf_runall_queues( | |
1729 | struct workqueue_struct *queue) | |
1730 | { | |
1731 | flush_workqueue(queue); | |
1732 | } | |
1733 | ||
1da177e4 | 1734 | STATIC int |
23ea4032 | 1735 | xfsbufd_wakeup( |
15c84a47 NS |
1736 | int priority, |
1737 | gfp_t mask) | |
1da177e4 | 1738 | { |
a6867a68 DC |
1739 | xfs_buftarg_t *btp, *n; |
1740 | ||
1741 | spin_lock(&xfs_buftarg_lock); | |
1742 | list_for_each_entry_safe(btp, n, &xfs_buftarg_list, bt_list) { | |
1743 | if (test_bit(BT_FORCE_SLEEP, &btp->bt_flags)) | |
1744 | continue; | |
1745 | set_bit(BT_FORCE_FLUSH, &btp->bt_flags); | |
1746 | barrier(); | |
1747 | wake_up_process(btp->bt_task); | |
1748 | } | |
1749 | spin_unlock(&xfs_buftarg_lock); | |
1da177e4 LT |
1750 | return 0; |
1751 | } | |
1752 | ||
1753 | STATIC int | |
23ea4032 | 1754 | xfsbufd( |
1da177e4 LT |
1755 | void *data) |
1756 | { | |
1757 | struct list_head tmp; | |
1758 | unsigned long age; | |
a6867a68 | 1759 | xfs_buftarg_t *target = (xfs_buftarg_t *)data; |
1da177e4 | 1760 | xfs_buf_t *pb, *n; |
a6867a68 DC |
1761 | struct list_head *dwq = &target->bt_delwrite_queue; |
1762 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1da177e4 | 1763 | |
1da177e4 LT |
1764 | current->flags |= PF_MEMALLOC; |
1765 | ||
1da177e4 LT |
1766 | INIT_LIST_HEAD(&tmp); |
1767 | do { | |
3e1d1d28 | 1768 | if (unlikely(freezing(current))) { |
a6867a68 | 1769 | set_bit(BT_FORCE_SLEEP, &target->bt_flags); |
3e1d1d28 | 1770 | refrigerator(); |
abd0cf7a | 1771 | } else { |
a6867a68 | 1772 | clear_bit(BT_FORCE_SLEEP, &target->bt_flags); |
abd0cf7a | 1773 | } |
1da177e4 | 1774 | |
15c84a47 NS |
1775 | schedule_timeout_interruptible( |
1776 | xfs_buf_timer_centisecs * msecs_to_jiffies(10)); | |
1da177e4 | 1777 | |
041e0e3b | 1778 | age = xfs_buf_age_centisecs * msecs_to_jiffies(10); |
a6867a68 DC |
1779 | spin_lock(dwlk); |
1780 | list_for_each_entry_safe(pb, n, dwq, pb_list) { | |
1da177e4 LT |
1781 | PB_TRACE(pb, "walkq1", (long)pagebuf_ispin(pb)); |
1782 | ASSERT(pb->pb_flags & PBF_DELWRI); | |
1783 | ||
1784 | if (!pagebuf_ispin(pb) && !pagebuf_cond_lock(pb)) { | |
a6867a68 DC |
1785 | if (!test_bit(BT_FORCE_FLUSH, |
1786 | &target->bt_flags) && | |
1da177e4 LT |
1787 | time_before(jiffies, |
1788 | pb->pb_queuetime + age)) { | |
1789 | pagebuf_unlock(pb); | |
1790 | break; | |
1791 | } | |
1792 | ||
2f926587 | 1793 | pb->pb_flags &= ~(PBF_DELWRI|_PBF_DELWRI_Q); |
1da177e4 LT |
1794 | pb->pb_flags |= PBF_WRITE; |
1795 | list_move(&pb->pb_list, &tmp); | |
1796 | } | |
1797 | } | |
a6867a68 | 1798 | spin_unlock(dwlk); |
1da177e4 LT |
1799 | |
1800 | while (!list_empty(&tmp)) { | |
1801 | pb = list_entry(tmp.next, xfs_buf_t, pb_list); | |
a6867a68 | 1802 | ASSERT(target == pb->pb_target); |
1da177e4 LT |
1803 | |
1804 | list_del_init(&pb->pb_list); | |
1805 | pagebuf_iostrategy(pb); | |
1806 | ||
1807 | blk_run_address_space(target->pbr_mapping); | |
1808 | } | |
1809 | ||
1810 | if (as_list_len > 0) | |
1811 | purge_addresses(); | |
1812 | ||
a6867a68 | 1813 | clear_bit(BT_FORCE_FLUSH, &target->bt_flags); |
4df08c52 | 1814 | } while (!kthread_should_stop()); |
1da177e4 | 1815 | |
4df08c52 | 1816 | return 0; |
1da177e4 LT |
1817 | } |
1818 | ||
1819 | /* | |
1820 | * Go through all incore buffers, and release buffers if they belong to | |
1821 | * the given device. This is used in filesystem error handling to | |
1822 | * preserve the consistency of its metadata. | |
1823 | */ | |
1824 | int | |
1825 | xfs_flush_buftarg( | |
1826 | xfs_buftarg_t *target, | |
1827 | int wait) | |
1828 | { | |
1829 | struct list_head tmp; | |
1830 | xfs_buf_t *pb, *n; | |
1831 | int pincount = 0; | |
a6867a68 DC |
1832 | struct list_head *dwq = &target->bt_delwrite_queue; |
1833 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1da177e4 | 1834 | |
23ea4032 CH |
1835 | pagebuf_runall_queues(xfsdatad_workqueue); |
1836 | pagebuf_runall_queues(xfslogd_workqueue); | |
1da177e4 LT |
1837 | |
1838 | INIT_LIST_HEAD(&tmp); | |
a6867a68 DC |
1839 | spin_lock(dwlk); |
1840 | list_for_each_entry_safe(pb, n, dwq, pb_list) { | |
1da177e4 | 1841 | |
a6867a68 | 1842 | ASSERT(pb->pb_target == target); |
2f926587 | 1843 | ASSERT(pb->pb_flags & (PBF_DELWRI|_PBF_DELWRI_Q)); |
1da177e4 LT |
1844 | PB_TRACE(pb, "walkq2", (long)pagebuf_ispin(pb)); |
1845 | if (pagebuf_ispin(pb)) { | |
1846 | pincount++; | |
1847 | continue; | |
1848 | } | |
1849 | ||
1da177e4 LT |
1850 | list_move(&pb->pb_list, &tmp); |
1851 | } | |
a6867a68 | 1852 | spin_unlock(dwlk); |
1da177e4 LT |
1853 | |
1854 | /* | |
1855 | * Dropped the delayed write list lock, now walk the temporary list | |
1856 | */ | |
1857 | list_for_each_entry_safe(pb, n, &tmp, pb_list) { | |
2f926587 DC |
1858 | pagebuf_lock(pb); |
1859 | pb->pb_flags &= ~(PBF_DELWRI|_PBF_DELWRI_Q); | |
1860 | pb->pb_flags |= PBF_WRITE; | |
1da177e4 LT |
1861 | if (wait) |
1862 | pb->pb_flags &= ~PBF_ASYNC; | |
1863 | else | |
1864 | list_del_init(&pb->pb_list); | |
1865 | ||
1da177e4 LT |
1866 | pagebuf_iostrategy(pb); |
1867 | } | |
1868 | ||
1869 | /* | |
1870 | * Remaining list items must be flushed before returning | |
1871 | */ | |
1872 | while (!list_empty(&tmp)) { | |
1873 | pb = list_entry(tmp.next, xfs_buf_t, pb_list); | |
1874 | ||
1875 | list_del_init(&pb->pb_list); | |
1876 | xfs_iowait(pb); | |
1877 | xfs_buf_relse(pb); | |
1878 | } | |
1879 | ||
1880 | if (wait) | |
1881 | blk_run_address_space(target->pbr_mapping); | |
1882 | ||
1883 | return pincount; | |
1884 | } | |
1885 | ||
04d8b284 CH |
1886 | int __init |
1887 | pagebuf_init(void) | |
1da177e4 | 1888 | { |
23ea4032 | 1889 | int error = -ENOMEM; |
1da177e4 | 1890 | |
04d8b284 CH |
1891 | #ifdef PAGEBUF_TRACE |
1892 | pagebuf_trace_buf = ktrace_alloc(PAGEBUF_TRACE_SIZE, KM_SLEEP); | |
1893 | #endif | |
1894 | ||
1895 | pagebuf_zone = kmem_zone_init(sizeof(xfs_buf_t), "xfs_buf"); | |
1896 | if (!pagebuf_zone) | |
1897 | goto out_free_trace_buf; | |
1898 | ||
23ea4032 CH |
1899 | xfslogd_workqueue = create_workqueue("xfslogd"); |
1900 | if (!xfslogd_workqueue) | |
04d8b284 | 1901 | goto out_free_buf_zone; |
1da177e4 | 1902 | |
23ea4032 CH |
1903 | xfsdatad_workqueue = create_workqueue("xfsdatad"); |
1904 | if (!xfsdatad_workqueue) | |
1905 | goto out_destroy_xfslogd_workqueue; | |
1da177e4 | 1906 | |
04d8b284 CH |
1907 | pagebuf_shake = kmem_shake_register(xfsbufd_wakeup); |
1908 | if (!pagebuf_shake) | |
a6867a68 | 1909 | goto out_destroy_xfsdatad_workqueue; |
04d8b284 | 1910 | |
23ea4032 | 1911 | return 0; |
1da177e4 | 1912 | |
23ea4032 CH |
1913 | out_destroy_xfsdatad_workqueue: |
1914 | destroy_workqueue(xfsdatad_workqueue); | |
1915 | out_destroy_xfslogd_workqueue: | |
1916 | destroy_workqueue(xfslogd_workqueue); | |
23ea4032 | 1917 | out_free_buf_zone: |
04d8b284 CH |
1918 | kmem_zone_destroy(pagebuf_zone); |
1919 | out_free_trace_buf: | |
23ea4032 CH |
1920 | #ifdef PAGEBUF_TRACE |
1921 | ktrace_free(pagebuf_trace_buf); | |
1922 | #endif | |
23ea4032 | 1923 | return error; |
1da177e4 LT |
1924 | } |
1925 | ||
1da177e4 LT |
1926 | void |
1927 | pagebuf_terminate(void) | |
1928 | { | |
04d8b284 | 1929 | kmem_shake_deregister(pagebuf_shake); |
04d8b284 CH |
1930 | destroy_workqueue(xfsdatad_workqueue); |
1931 | destroy_workqueue(xfslogd_workqueue); | |
1932 | kmem_zone_destroy(pagebuf_zone); | |
1da177e4 LT |
1933 | #ifdef PAGEBUF_TRACE |
1934 | ktrace_free(pagebuf_trace_buf); | |
1935 | #endif | |
1da177e4 | 1936 | } |