Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
f07c2250 | 2 | * Copyright (c) 2000-2006 Silicon Graphics, Inc. |
7b718769 | 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 | */ |
93c189c1 | 18 | #include "xfs.h" |
1da177e4 LT |
19 | #include <linux/stddef.h> |
20 | #include <linux/errno.h> | |
5a0e3ad6 | 21 | #include <linux/gfp.h> |
1da177e4 LT |
22 | #include <linux/pagemap.h> |
23 | #include <linux/init.h> | |
24 | #include <linux/vmalloc.h> | |
25 | #include <linux/bio.h> | |
26 | #include <linux/sysctl.h> | |
27 | #include <linux/proc_fs.h> | |
28 | #include <linux/workqueue.h> | |
29 | #include <linux/percpu.h> | |
30 | #include <linux/blkdev.h> | |
31 | #include <linux/hash.h> | |
4df08c52 | 32 | #include <linux/kthread.h> |
b20a3503 | 33 | #include <linux/migrate.h> |
3fcfab16 | 34 | #include <linux/backing-dev.h> |
7dfb7103 | 35 | #include <linux/freezer.h> |
089716aa | 36 | #include <linux/list_sort.h> |
1da177e4 | 37 | |
b7963133 CH |
38 | #include "xfs_sb.h" |
39 | #include "xfs_inum.h" | |
ed3b4d6c | 40 | #include "xfs_log.h" |
b7963133 | 41 | #include "xfs_ag.h" |
b7963133 | 42 | #include "xfs_mount.h" |
0b1b213f | 43 | #include "xfs_trace.h" |
b7963133 | 44 | |
7989cb8e | 45 | static kmem_zone_t *xfs_buf_zone; |
a6867a68 | 46 | STATIC int xfsbufd(void *); |
ce8e922c | 47 | STATIC void xfs_buf_delwri_queue(xfs_buf_t *, int); |
23ea4032 | 48 | |
7989cb8e | 49 | static struct workqueue_struct *xfslogd_workqueue; |
0829c360 | 50 | struct workqueue_struct *xfsdatad_workqueue; |
c626d174 | 51 | struct workqueue_struct *xfsconvertd_workqueue; |
1da177e4 | 52 | |
ce8e922c NS |
53 | #ifdef XFS_BUF_LOCK_TRACKING |
54 | # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid) | |
55 | # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1) | |
56 | # define XB_GET_OWNER(bp) ((bp)->b_last_holder) | |
1da177e4 | 57 | #else |
ce8e922c NS |
58 | # define XB_SET_OWNER(bp) do { } while (0) |
59 | # define XB_CLEAR_OWNER(bp) do { } while (0) | |
60 | # define XB_GET_OWNER(bp) do { } while (0) | |
1da177e4 LT |
61 | #endif |
62 | ||
ce8e922c NS |
63 | #define xb_to_gfp(flags) \ |
64 | ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : \ | |
65 | ((flags) & XBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN) | |
1da177e4 | 66 | |
ce8e922c NS |
67 | #define xb_to_km(flags) \ |
68 | (((flags) & XBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP) | |
1da177e4 | 69 | |
ce8e922c NS |
70 | #define xfs_buf_allocate(flags) \ |
71 | kmem_zone_alloc(xfs_buf_zone, xb_to_km(flags)) | |
72 | #define xfs_buf_deallocate(bp) \ | |
73 | kmem_zone_free(xfs_buf_zone, (bp)); | |
1da177e4 | 74 | |
73c77e2c JB |
75 | static inline int |
76 | xfs_buf_is_vmapped( | |
77 | struct xfs_buf *bp) | |
78 | { | |
79 | /* | |
80 | * Return true if the buffer is vmapped. | |
81 | * | |
82 | * The XBF_MAPPED flag is set if the buffer should be mapped, but the | |
83 | * code is clever enough to know it doesn't have to map a single page, | |
84 | * so the check has to be both for XBF_MAPPED and bp->b_page_count > 1. | |
85 | */ | |
86 | return (bp->b_flags & XBF_MAPPED) && bp->b_page_count > 1; | |
87 | } | |
88 | ||
89 | static inline int | |
90 | xfs_buf_vmap_len( | |
91 | struct xfs_buf *bp) | |
92 | { | |
93 | return (bp->b_page_count * PAGE_SIZE) - bp->b_offset; | |
94 | } | |
95 | ||
1da177e4 | 96 | /* |
ce8e922c | 97 | * Page Region interfaces. |
1da177e4 | 98 | * |
ce8e922c NS |
99 | * For pages in filesystems where the blocksize is smaller than the |
100 | * pagesize, we use the page->private field (long) to hold a bitmap | |
101 | * of uptodate regions within the page. | |
1da177e4 | 102 | * |
ce8e922c | 103 | * Each such region is "bytes per page / bits per long" bytes long. |
1da177e4 | 104 | * |
ce8e922c NS |
105 | * NBPPR == number-of-bytes-per-page-region |
106 | * BTOPR == bytes-to-page-region (rounded up) | |
107 | * BTOPRT == bytes-to-page-region-truncated (rounded down) | |
1da177e4 LT |
108 | */ |
109 | #if (BITS_PER_LONG == 32) | |
110 | #define PRSHIFT (PAGE_CACHE_SHIFT - 5) /* (32 == 1<<5) */ | |
111 | #elif (BITS_PER_LONG == 64) | |
112 | #define PRSHIFT (PAGE_CACHE_SHIFT - 6) /* (64 == 1<<6) */ | |
113 | #else | |
114 | #error BITS_PER_LONG must be 32 or 64 | |
115 | #endif | |
116 | #define NBPPR (PAGE_CACHE_SIZE/BITS_PER_LONG) | |
117 | #define BTOPR(b) (((unsigned int)(b) + (NBPPR - 1)) >> PRSHIFT) | |
118 | #define BTOPRT(b) (((unsigned int)(b) >> PRSHIFT)) | |
119 | ||
120 | STATIC unsigned long | |
121 | page_region_mask( | |
122 | size_t offset, | |
123 | size_t length) | |
124 | { | |
125 | unsigned long mask; | |
126 | int first, final; | |
127 | ||
128 | first = BTOPR(offset); | |
129 | final = BTOPRT(offset + length - 1); | |
130 | first = min(first, final); | |
131 | ||
132 | mask = ~0UL; | |
133 | mask <<= BITS_PER_LONG - (final - first); | |
134 | mask >>= BITS_PER_LONG - (final); | |
135 | ||
136 | ASSERT(offset + length <= PAGE_CACHE_SIZE); | |
137 | ASSERT((final - first) < BITS_PER_LONG && (final - first) >= 0); | |
138 | ||
139 | return mask; | |
140 | } | |
141 | ||
b8f82a4a | 142 | STATIC void |
1da177e4 LT |
143 | set_page_region( |
144 | struct page *page, | |
145 | size_t offset, | |
146 | size_t length) | |
147 | { | |
4c21e2f2 HD |
148 | set_page_private(page, |
149 | page_private(page) | page_region_mask(offset, length)); | |
150 | if (page_private(page) == ~0UL) | |
1da177e4 LT |
151 | SetPageUptodate(page); |
152 | } | |
153 | ||
b8f82a4a | 154 | STATIC int |
1da177e4 LT |
155 | test_page_region( |
156 | struct page *page, | |
157 | size_t offset, | |
158 | size_t length) | |
159 | { | |
160 | unsigned long mask = page_region_mask(offset, length); | |
161 | ||
4c21e2f2 | 162 | return (mask && (page_private(page) & mask) == mask); |
1da177e4 LT |
163 | } |
164 | ||
1da177e4 | 165 | /* |
430cbeb8 DC |
166 | * xfs_buf_lru_add - add a buffer to the LRU. |
167 | * | |
168 | * The LRU takes a new reference to the buffer so that it will only be freed | |
169 | * once the shrinker takes the buffer off the LRU. | |
170 | */ | |
171 | STATIC void | |
172 | xfs_buf_lru_add( | |
173 | struct xfs_buf *bp) | |
174 | { | |
175 | struct xfs_buftarg *btp = bp->b_target; | |
176 | ||
177 | spin_lock(&btp->bt_lru_lock); | |
178 | if (list_empty(&bp->b_lru)) { | |
179 | atomic_inc(&bp->b_hold); | |
180 | list_add_tail(&bp->b_lru, &btp->bt_lru); | |
181 | btp->bt_lru_nr++; | |
182 | } | |
183 | spin_unlock(&btp->bt_lru_lock); | |
184 | } | |
185 | ||
186 | /* | |
187 | * xfs_buf_lru_del - remove a buffer from the LRU | |
188 | * | |
189 | * The unlocked check is safe here because it only occurs when there are not | |
190 | * b_lru_ref counts left on the inode under the pag->pag_buf_lock. it is there | |
191 | * to optimise the shrinker removing the buffer from the LRU and calling | |
192 | * xfs_buf_free(). i.e. it removes an unneccessary round trip on the | |
193 | * bt_lru_lock. | |
1da177e4 | 194 | */ |
430cbeb8 DC |
195 | STATIC void |
196 | xfs_buf_lru_del( | |
197 | struct xfs_buf *bp) | |
198 | { | |
199 | struct xfs_buftarg *btp = bp->b_target; | |
200 | ||
201 | if (list_empty(&bp->b_lru)) | |
202 | return; | |
203 | ||
204 | spin_lock(&btp->bt_lru_lock); | |
205 | if (!list_empty(&bp->b_lru)) { | |
206 | list_del_init(&bp->b_lru); | |
207 | btp->bt_lru_nr--; | |
208 | } | |
209 | spin_unlock(&btp->bt_lru_lock); | |
210 | } | |
211 | ||
212 | /* | |
213 | * When we mark a buffer stale, we remove the buffer from the LRU and clear the | |
214 | * b_lru_ref count so that the buffer is freed immediately when the buffer | |
215 | * reference count falls to zero. If the buffer is already on the LRU, we need | |
216 | * to remove the reference that LRU holds on the buffer. | |
217 | * | |
218 | * This prevents build-up of stale buffers on the LRU. | |
219 | */ | |
220 | void | |
221 | xfs_buf_stale( | |
222 | struct xfs_buf *bp) | |
223 | { | |
224 | bp->b_flags |= XBF_STALE; | |
225 | atomic_set(&(bp)->b_lru_ref, 0); | |
226 | if (!list_empty(&bp->b_lru)) { | |
227 | struct xfs_buftarg *btp = bp->b_target; | |
228 | ||
229 | spin_lock(&btp->bt_lru_lock); | |
230 | if (!list_empty(&bp->b_lru)) { | |
231 | list_del_init(&bp->b_lru); | |
232 | btp->bt_lru_nr--; | |
233 | atomic_dec(&bp->b_hold); | |
234 | } | |
235 | spin_unlock(&btp->bt_lru_lock); | |
236 | } | |
237 | ASSERT(atomic_read(&bp->b_hold) >= 1); | |
238 | } | |
1da177e4 LT |
239 | |
240 | STATIC void | |
ce8e922c NS |
241 | _xfs_buf_initialize( |
242 | xfs_buf_t *bp, | |
1da177e4 | 243 | xfs_buftarg_t *target, |
204ab25f | 244 | xfs_off_t range_base, |
1da177e4 | 245 | size_t range_length, |
ce8e922c | 246 | xfs_buf_flags_t flags) |
1da177e4 LT |
247 | { |
248 | /* | |
ce8e922c | 249 | * We don't want certain flags to appear in b_flags. |
1da177e4 | 250 | */ |
ce8e922c NS |
251 | flags &= ~(XBF_LOCK|XBF_MAPPED|XBF_DONT_BLOCK|XBF_READ_AHEAD); |
252 | ||
253 | memset(bp, 0, sizeof(xfs_buf_t)); | |
254 | atomic_set(&bp->b_hold, 1); | |
430cbeb8 | 255 | atomic_set(&bp->b_lru_ref, 1); |
b4dd330b | 256 | init_completion(&bp->b_iowait); |
430cbeb8 | 257 | INIT_LIST_HEAD(&bp->b_lru); |
ce8e922c | 258 | INIT_LIST_HEAD(&bp->b_list); |
74f75a0c | 259 | RB_CLEAR_NODE(&bp->b_rbnode); |
a731cd11 | 260 | sema_init(&bp->b_sema, 0); /* held, no waiters */ |
ce8e922c NS |
261 | XB_SET_OWNER(bp); |
262 | bp->b_target = target; | |
263 | bp->b_file_offset = range_base; | |
1da177e4 LT |
264 | /* |
265 | * Set buffer_length and count_desired to the same value initially. | |
266 | * I/O routines should use count_desired, which will be the same in | |
267 | * most cases but may be reset (e.g. XFS recovery). | |
268 | */ | |
ce8e922c NS |
269 | bp->b_buffer_length = bp->b_count_desired = range_length; |
270 | bp->b_flags = flags; | |
271 | bp->b_bn = XFS_BUF_DADDR_NULL; | |
272 | atomic_set(&bp->b_pin_count, 0); | |
273 | init_waitqueue_head(&bp->b_waiters); | |
274 | ||
275 | XFS_STATS_INC(xb_create); | |
0b1b213f CH |
276 | |
277 | trace_xfs_buf_init(bp, _RET_IP_); | |
1da177e4 LT |
278 | } |
279 | ||
280 | /* | |
ce8e922c NS |
281 | * Allocate a page array capable of holding a specified number |
282 | * of pages, and point the page buf at it. | |
1da177e4 LT |
283 | */ |
284 | STATIC int | |
ce8e922c NS |
285 | _xfs_buf_get_pages( |
286 | xfs_buf_t *bp, | |
1da177e4 | 287 | int page_count, |
ce8e922c | 288 | xfs_buf_flags_t flags) |
1da177e4 LT |
289 | { |
290 | /* Make sure that we have a page list */ | |
ce8e922c NS |
291 | if (bp->b_pages == NULL) { |
292 | bp->b_offset = xfs_buf_poff(bp->b_file_offset); | |
293 | bp->b_page_count = page_count; | |
294 | if (page_count <= XB_PAGES) { | |
295 | bp->b_pages = bp->b_page_array; | |
1da177e4 | 296 | } else { |
ce8e922c NS |
297 | bp->b_pages = kmem_alloc(sizeof(struct page *) * |
298 | page_count, xb_to_km(flags)); | |
299 | if (bp->b_pages == NULL) | |
1da177e4 LT |
300 | return -ENOMEM; |
301 | } | |
ce8e922c | 302 | memset(bp->b_pages, 0, sizeof(struct page *) * page_count); |
1da177e4 LT |
303 | } |
304 | return 0; | |
305 | } | |
306 | ||
307 | /* | |
ce8e922c | 308 | * Frees b_pages if it was allocated. |
1da177e4 LT |
309 | */ |
310 | STATIC void | |
ce8e922c | 311 | _xfs_buf_free_pages( |
1da177e4 LT |
312 | xfs_buf_t *bp) |
313 | { | |
ce8e922c | 314 | if (bp->b_pages != bp->b_page_array) { |
f0e2d93c | 315 | kmem_free(bp->b_pages); |
3fc98b1a | 316 | bp->b_pages = NULL; |
1da177e4 LT |
317 | } |
318 | } | |
319 | ||
320 | /* | |
321 | * Releases the specified buffer. | |
322 | * | |
323 | * The modification state of any associated pages is left unchanged. | |
ce8e922c | 324 | * The buffer most not be on any hash - use xfs_buf_rele instead for |
1da177e4 LT |
325 | * hashed and refcounted buffers |
326 | */ | |
327 | void | |
ce8e922c | 328 | xfs_buf_free( |
1da177e4 LT |
329 | xfs_buf_t *bp) |
330 | { | |
0b1b213f | 331 | trace_xfs_buf_free(bp, _RET_IP_); |
1da177e4 | 332 | |
430cbeb8 DC |
333 | ASSERT(list_empty(&bp->b_lru)); |
334 | ||
1fa40b01 | 335 | if (bp->b_flags & (_XBF_PAGE_CACHE|_XBF_PAGES)) { |
1da177e4 LT |
336 | uint i; |
337 | ||
73c77e2c | 338 | if (xfs_buf_is_vmapped(bp)) |
8a262e57 AE |
339 | vm_unmap_ram(bp->b_addr - bp->b_offset, |
340 | bp->b_page_count); | |
1da177e4 | 341 | |
948ecdb4 NS |
342 | for (i = 0; i < bp->b_page_count; i++) { |
343 | struct page *page = bp->b_pages[i]; | |
344 | ||
1fa40b01 CH |
345 | if (bp->b_flags & _XBF_PAGE_CACHE) |
346 | ASSERT(!PagePrivate(page)); | |
948ecdb4 NS |
347 | page_cache_release(page); |
348 | } | |
1da177e4 | 349 | } |
3fc98b1a | 350 | _xfs_buf_free_pages(bp); |
ce8e922c | 351 | xfs_buf_deallocate(bp); |
1da177e4 LT |
352 | } |
353 | ||
354 | /* | |
355 | * Finds all pages for buffer in question and builds it's page list. | |
356 | */ | |
357 | STATIC int | |
ce8e922c | 358 | _xfs_buf_lookup_pages( |
1da177e4 LT |
359 | xfs_buf_t *bp, |
360 | uint flags) | |
361 | { | |
ce8e922c NS |
362 | struct address_space *mapping = bp->b_target->bt_mapping; |
363 | size_t blocksize = bp->b_target->bt_bsize; | |
364 | size_t size = bp->b_count_desired; | |
1da177e4 | 365 | size_t nbytes, offset; |
ce8e922c | 366 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 LT |
367 | unsigned short page_count, i; |
368 | pgoff_t first; | |
204ab25f | 369 | xfs_off_t end; |
1da177e4 LT |
370 | int error; |
371 | ||
ce8e922c NS |
372 | end = bp->b_file_offset + bp->b_buffer_length; |
373 | page_count = xfs_buf_btoc(end) - xfs_buf_btoct(bp->b_file_offset); | |
1da177e4 | 374 | |
ce8e922c | 375 | error = _xfs_buf_get_pages(bp, page_count, flags); |
1da177e4 LT |
376 | if (unlikely(error)) |
377 | return error; | |
ce8e922c | 378 | bp->b_flags |= _XBF_PAGE_CACHE; |
1da177e4 | 379 | |
ce8e922c NS |
380 | offset = bp->b_offset; |
381 | first = bp->b_file_offset >> PAGE_CACHE_SHIFT; | |
1da177e4 | 382 | |
ce8e922c | 383 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
384 | struct page *page; |
385 | uint retries = 0; | |
386 | ||
387 | retry: | |
388 | page = find_or_create_page(mapping, first + i, gfp_mask); | |
389 | if (unlikely(page == NULL)) { | |
ce8e922c NS |
390 | if (flags & XBF_READ_AHEAD) { |
391 | bp->b_page_count = i; | |
6ab455ee CH |
392 | for (i = 0; i < bp->b_page_count; i++) |
393 | unlock_page(bp->b_pages[i]); | |
1da177e4 LT |
394 | return -ENOMEM; |
395 | } | |
396 | ||
397 | /* | |
398 | * This could deadlock. | |
399 | * | |
400 | * But until all the XFS lowlevel code is revamped to | |
401 | * handle buffer allocation failures we can't do much. | |
402 | */ | |
403 | if (!(++retries % 100)) | |
4f10700a DC |
404 | xfs_err(NULL, |
405 | "possible memory allocation deadlock in %s (mode:0x%x)", | |
34a622b2 | 406 | __func__, gfp_mask); |
1da177e4 | 407 | |
ce8e922c | 408 | XFS_STATS_INC(xb_page_retries); |
8aa7e847 | 409 | congestion_wait(BLK_RW_ASYNC, HZ/50); |
1da177e4 LT |
410 | goto retry; |
411 | } | |
412 | ||
ce8e922c | 413 | XFS_STATS_INC(xb_page_found); |
1da177e4 LT |
414 | |
415 | nbytes = min_t(size_t, size, PAGE_CACHE_SIZE - offset); | |
416 | size -= nbytes; | |
417 | ||
948ecdb4 | 418 | ASSERT(!PagePrivate(page)); |
1da177e4 LT |
419 | if (!PageUptodate(page)) { |
420 | page_count--; | |
6ab455ee CH |
421 | if (blocksize >= PAGE_CACHE_SIZE) { |
422 | if (flags & XBF_READ) | |
423 | bp->b_flags |= _XBF_PAGE_LOCKED; | |
424 | } else if (!PagePrivate(page)) { | |
1da177e4 LT |
425 | if (test_page_region(page, offset, nbytes)) |
426 | page_count++; | |
427 | } | |
428 | } | |
429 | ||
ce8e922c | 430 | bp->b_pages[i] = page; |
1da177e4 LT |
431 | offset = 0; |
432 | } | |
433 | ||
6ab455ee CH |
434 | if (!(bp->b_flags & _XBF_PAGE_LOCKED)) { |
435 | for (i = 0; i < bp->b_page_count; i++) | |
436 | unlock_page(bp->b_pages[i]); | |
437 | } | |
438 | ||
ce8e922c NS |
439 | if (page_count == bp->b_page_count) |
440 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 441 | |
1da177e4 LT |
442 | return error; |
443 | } | |
444 | ||
445 | /* | |
446 | * Map buffer into kernel address-space if nessecary. | |
447 | */ | |
448 | STATIC int | |
ce8e922c | 449 | _xfs_buf_map_pages( |
1da177e4 LT |
450 | xfs_buf_t *bp, |
451 | uint flags) | |
452 | { | |
453 | /* A single page buffer is always mappable */ | |
ce8e922c NS |
454 | if (bp->b_page_count == 1) { |
455 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; | |
456 | bp->b_flags |= XBF_MAPPED; | |
457 | } else if (flags & XBF_MAPPED) { | |
a19fb380 DC |
458 | int retried = 0; |
459 | ||
460 | do { | |
461 | bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, | |
462 | -1, PAGE_KERNEL); | |
463 | if (bp->b_addr) | |
464 | break; | |
465 | vm_unmap_aliases(); | |
466 | } while (retried++ <= 1); | |
467 | ||
468 | if (!bp->b_addr) | |
1da177e4 | 469 | return -ENOMEM; |
ce8e922c NS |
470 | bp->b_addr += bp->b_offset; |
471 | bp->b_flags |= XBF_MAPPED; | |
1da177e4 LT |
472 | } |
473 | ||
474 | return 0; | |
475 | } | |
476 | ||
477 | /* | |
478 | * Finding and Reading Buffers | |
479 | */ | |
480 | ||
481 | /* | |
ce8e922c | 482 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 LT |
483 | * a given range of an inode. The buffer is returned |
484 | * locked. If other overlapping buffers exist, they are | |
485 | * released before the new buffer is created and locked, | |
486 | * which may imply that this call will block until those buffers | |
487 | * are unlocked. No I/O is implied by this call. | |
488 | */ | |
489 | xfs_buf_t * | |
ce8e922c | 490 | _xfs_buf_find( |
1da177e4 | 491 | xfs_buftarg_t *btp, /* block device target */ |
204ab25f | 492 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 493 | size_t isize, /* length of range */ |
ce8e922c NS |
494 | xfs_buf_flags_t flags, |
495 | xfs_buf_t *new_bp) | |
1da177e4 | 496 | { |
204ab25f | 497 | xfs_off_t range_base; |
1da177e4 | 498 | size_t range_length; |
74f75a0c DC |
499 | struct xfs_perag *pag; |
500 | struct rb_node **rbp; | |
501 | struct rb_node *parent; | |
502 | xfs_buf_t *bp; | |
1da177e4 LT |
503 | |
504 | range_base = (ioff << BBSHIFT); | |
505 | range_length = (isize << BBSHIFT); | |
506 | ||
507 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
ce8e922c | 508 | ASSERT(!(range_length < (1 << btp->bt_sshift))); |
204ab25f | 509 | ASSERT(!(range_base & (xfs_off_t)btp->bt_smask)); |
1da177e4 | 510 | |
74f75a0c DC |
511 | /* get tree root */ |
512 | pag = xfs_perag_get(btp->bt_mount, | |
513 | xfs_daddr_to_agno(btp->bt_mount, ioff)); | |
514 | ||
515 | /* walk tree */ | |
516 | spin_lock(&pag->pag_buf_lock); | |
517 | rbp = &pag->pag_buf_tree.rb_node; | |
518 | parent = NULL; | |
519 | bp = NULL; | |
520 | while (*rbp) { | |
521 | parent = *rbp; | |
522 | bp = rb_entry(parent, struct xfs_buf, b_rbnode); | |
523 | ||
524 | if (range_base < bp->b_file_offset) | |
525 | rbp = &(*rbp)->rb_left; | |
526 | else if (range_base > bp->b_file_offset) | |
527 | rbp = &(*rbp)->rb_right; | |
528 | else { | |
529 | /* | |
530 | * found a block offset match. If the range doesn't | |
531 | * match, the only way this is allowed is if the buffer | |
532 | * in the cache is stale and the transaction that made | |
533 | * it stale has not yet committed. i.e. we are | |
534 | * reallocating a busy extent. Skip this buffer and | |
535 | * continue searching to the right for an exact match. | |
536 | */ | |
537 | if (bp->b_buffer_length != range_length) { | |
538 | ASSERT(bp->b_flags & XBF_STALE); | |
539 | rbp = &(*rbp)->rb_right; | |
540 | continue; | |
541 | } | |
ce8e922c | 542 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
543 | goto found; |
544 | } | |
545 | } | |
546 | ||
547 | /* No match found */ | |
ce8e922c NS |
548 | if (new_bp) { |
549 | _xfs_buf_initialize(new_bp, btp, range_base, | |
1da177e4 | 550 | range_length, flags); |
74f75a0c DC |
551 | rb_link_node(&new_bp->b_rbnode, parent, rbp); |
552 | rb_insert_color(&new_bp->b_rbnode, &pag->pag_buf_tree); | |
553 | /* the buffer keeps the perag reference until it is freed */ | |
554 | new_bp->b_pag = pag; | |
555 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 556 | } else { |
ce8e922c | 557 | XFS_STATS_INC(xb_miss_locked); |
74f75a0c DC |
558 | spin_unlock(&pag->pag_buf_lock); |
559 | xfs_perag_put(pag); | |
1da177e4 | 560 | } |
ce8e922c | 561 | return new_bp; |
1da177e4 LT |
562 | |
563 | found: | |
74f75a0c DC |
564 | spin_unlock(&pag->pag_buf_lock); |
565 | xfs_perag_put(pag); | |
1da177e4 | 566 | |
90810b9e DC |
567 | if (xfs_buf_cond_lock(bp)) { |
568 | /* failed, so wait for the lock if requested. */ | |
ce8e922c | 569 | if (!(flags & XBF_TRYLOCK)) { |
ce8e922c NS |
570 | xfs_buf_lock(bp); |
571 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 | 572 | } else { |
ce8e922c NS |
573 | xfs_buf_rele(bp); |
574 | XFS_STATS_INC(xb_busy_locked); | |
575 | return NULL; | |
1da177e4 | 576 | } |
1da177e4 LT |
577 | } |
578 | ||
ce8e922c NS |
579 | if (bp->b_flags & XBF_STALE) { |
580 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
581 | bp->b_flags &= XBF_MAPPED; | |
2f926587 | 582 | } |
0b1b213f CH |
583 | |
584 | trace_xfs_buf_find(bp, flags, _RET_IP_); | |
ce8e922c NS |
585 | XFS_STATS_INC(xb_get_locked); |
586 | return bp; | |
1da177e4 LT |
587 | } |
588 | ||
589 | /* | |
ce8e922c | 590 | * Assembles a buffer covering the specified range. |
1da177e4 LT |
591 | * Storage in memory for all portions of the buffer will be allocated, |
592 | * although backing storage may not be. | |
593 | */ | |
594 | xfs_buf_t * | |
6ad112bf | 595 | xfs_buf_get( |
1da177e4 | 596 | xfs_buftarg_t *target,/* target for buffer */ |
204ab25f | 597 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 598 | size_t isize, /* length of range */ |
ce8e922c | 599 | xfs_buf_flags_t flags) |
1da177e4 | 600 | { |
ce8e922c | 601 | xfs_buf_t *bp, *new_bp; |
1da177e4 LT |
602 | int error = 0, i; |
603 | ||
ce8e922c NS |
604 | new_bp = xfs_buf_allocate(flags); |
605 | if (unlikely(!new_bp)) | |
1da177e4 LT |
606 | return NULL; |
607 | ||
ce8e922c NS |
608 | bp = _xfs_buf_find(target, ioff, isize, flags, new_bp); |
609 | if (bp == new_bp) { | |
610 | error = _xfs_buf_lookup_pages(bp, flags); | |
1da177e4 LT |
611 | if (error) |
612 | goto no_buffer; | |
613 | } else { | |
ce8e922c NS |
614 | xfs_buf_deallocate(new_bp); |
615 | if (unlikely(bp == NULL)) | |
1da177e4 LT |
616 | return NULL; |
617 | } | |
618 | ||
ce8e922c NS |
619 | for (i = 0; i < bp->b_page_count; i++) |
620 | mark_page_accessed(bp->b_pages[i]); | |
1da177e4 | 621 | |
ce8e922c NS |
622 | if (!(bp->b_flags & XBF_MAPPED)) { |
623 | error = _xfs_buf_map_pages(bp, flags); | |
1da177e4 | 624 | if (unlikely(error)) { |
4f10700a DC |
625 | xfs_warn(target->bt_mount, |
626 | "%s: failed to map pages\n", __func__); | |
1da177e4 LT |
627 | goto no_buffer; |
628 | } | |
629 | } | |
630 | ||
ce8e922c | 631 | XFS_STATS_INC(xb_get); |
1da177e4 LT |
632 | |
633 | /* | |
634 | * Always fill in the block number now, the mapped cases can do | |
635 | * their own overlay of this later. | |
636 | */ | |
ce8e922c NS |
637 | bp->b_bn = ioff; |
638 | bp->b_count_desired = bp->b_buffer_length; | |
1da177e4 | 639 | |
0b1b213f | 640 | trace_xfs_buf_get(bp, flags, _RET_IP_); |
ce8e922c | 641 | return bp; |
1da177e4 LT |
642 | |
643 | no_buffer: | |
ce8e922c NS |
644 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
645 | xfs_buf_unlock(bp); | |
646 | xfs_buf_rele(bp); | |
1da177e4 LT |
647 | return NULL; |
648 | } | |
649 | ||
5d765b97 CH |
650 | STATIC int |
651 | _xfs_buf_read( | |
652 | xfs_buf_t *bp, | |
653 | xfs_buf_flags_t flags) | |
654 | { | |
655 | int status; | |
656 | ||
5d765b97 CH |
657 | ASSERT(!(flags & (XBF_DELWRI|XBF_WRITE))); |
658 | ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL); | |
659 | ||
660 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_DELWRI | \ | |
661 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
662 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | \ | |
663 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
664 | ||
665 | status = xfs_buf_iorequest(bp); | |
ec53d1db DC |
666 | if (status || XFS_BUF_ISERROR(bp) || (flags & XBF_ASYNC)) |
667 | return status; | |
668 | return xfs_buf_iowait(bp); | |
5d765b97 CH |
669 | } |
670 | ||
1da177e4 | 671 | xfs_buf_t * |
6ad112bf | 672 | xfs_buf_read( |
1da177e4 | 673 | xfs_buftarg_t *target, |
204ab25f | 674 | xfs_off_t ioff, |
1da177e4 | 675 | size_t isize, |
ce8e922c | 676 | xfs_buf_flags_t flags) |
1da177e4 | 677 | { |
ce8e922c NS |
678 | xfs_buf_t *bp; |
679 | ||
680 | flags |= XBF_READ; | |
681 | ||
6ad112bf | 682 | bp = xfs_buf_get(target, ioff, isize, flags); |
ce8e922c | 683 | if (bp) { |
0b1b213f CH |
684 | trace_xfs_buf_read(bp, flags, _RET_IP_); |
685 | ||
ce8e922c | 686 | if (!XFS_BUF_ISDONE(bp)) { |
ce8e922c | 687 | XFS_STATS_INC(xb_get_read); |
5d765b97 | 688 | _xfs_buf_read(bp, flags); |
ce8e922c | 689 | } else if (flags & XBF_ASYNC) { |
1da177e4 LT |
690 | /* |
691 | * Read ahead call which is already satisfied, | |
692 | * drop the buffer | |
693 | */ | |
694 | goto no_buffer; | |
695 | } else { | |
1da177e4 | 696 | /* We do not want read in the flags */ |
ce8e922c | 697 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
698 | } |
699 | } | |
700 | ||
ce8e922c | 701 | return bp; |
1da177e4 LT |
702 | |
703 | no_buffer: | |
ce8e922c NS |
704 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
705 | xfs_buf_unlock(bp); | |
706 | xfs_buf_rele(bp); | |
1da177e4 LT |
707 | return NULL; |
708 | } | |
709 | ||
1da177e4 | 710 | /* |
ce8e922c NS |
711 | * If we are not low on memory then do the readahead in a deadlock |
712 | * safe manner. | |
1da177e4 LT |
713 | */ |
714 | void | |
ce8e922c | 715 | xfs_buf_readahead( |
1da177e4 | 716 | xfs_buftarg_t *target, |
204ab25f | 717 | xfs_off_t ioff, |
1a1a3e97 | 718 | size_t isize) |
1da177e4 LT |
719 | { |
720 | struct backing_dev_info *bdi; | |
721 | ||
ce8e922c | 722 | bdi = target->bt_mapping->backing_dev_info; |
1da177e4 LT |
723 | if (bdi_read_congested(bdi)) |
724 | return; | |
725 | ||
1a1a3e97 CH |
726 | xfs_buf_read(target, ioff, isize, |
727 | XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD|XBF_DONT_BLOCK); | |
1da177e4 LT |
728 | } |
729 | ||
5adc94c2 DC |
730 | /* |
731 | * Read an uncached buffer from disk. Allocates and returns a locked | |
732 | * buffer containing the disk contents or nothing. | |
733 | */ | |
734 | struct xfs_buf * | |
735 | xfs_buf_read_uncached( | |
736 | struct xfs_mount *mp, | |
737 | struct xfs_buftarg *target, | |
738 | xfs_daddr_t daddr, | |
739 | size_t length, | |
740 | int flags) | |
741 | { | |
742 | xfs_buf_t *bp; | |
743 | int error; | |
744 | ||
745 | bp = xfs_buf_get_uncached(target, length, flags); | |
746 | if (!bp) | |
747 | return NULL; | |
748 | ||
749 | /* set up the buffer for a read IO */ | |
750 | xfs_buf_lock(bp); | |
751 | XFS_BUF_SET_ADDR(bp, daddr); | |
752 | XFS_BUF_READ(bp); | |
753 | XFS_BUF_BUSY(bp); | |
754 | ||
755 | xfsbdstrat(mp, bp); | |
1a1a3e97 | 756 | error = xfs_buf_iowait(bp); |
5adc94c2 DC |
757 | if (error || bp->b_error) { |
758 | xfs_buf_relse(bp); | |
759 | return NULL; | |
760 | } | |
761 | return bp; | |
1da177e4 LT |
762 | } |
763 | ||
764 | xfs_buf_t * | |
ce8e922c | 765 | xfs_buf_get_empty( |
1da177e4 LT |
766 | size_t len, |
767 | xfs_buftarg_t *target) | |
768 | { | |
ce8e922c | 769 | xfs_buf_t *bp; |
1da177e4 | 770 | |
ce8e922c NS |
771 | bp = xfs_buf_allocate(0); |
772 | if (bp) | |
773 | _xfs_buf_initialize(bp, target, 0, len, 0); | |
774 | return bp; | |
1da177e4 LT |
775 | } |
776 | ||
777 | static inline struct page * | |
778 | mem_to_page( | |
779 | void *addr) | |
780 | { | |
9e2779fa | 781 | if ((!is_vmalloc_addr(addr))) { |
1da177e4 LT |
782 | return virt_to_page(addr); |
783 | } else { | |
784 | return vmalloc_to_page(addr); | |
785 | } | |
786 | } | |
787 | ||
788 | int | |
ce8e922c NS |
789 | xfs_buf_associate_memory( |
790 | xfs_buf_t *bp, | |
1da177e4 LT |
791 | void *mem, |
792 | size_t len) | |
793 | { | |
794 | int rval; | |
795 | int i = 0; | |
d1afb678 LM |
796 | unsigned long pageaddr; |
797 | unsigned long offset; | |
798 | size_t buflen; | |
1da177e4 LT |
799 | int page_count; |
800 | ||
d1afb678 LM |
801 | pageaddr = (unsigned long)mem & PAGE_CACHE_MASK; |
802 | offset = (unsigned long)mem - pageaddr; | |
803 | buflen = PAGE_CACHE_ALIGN(len + offset); | |
804 | page_count = buflen >> PAGE_CACHE_SHIFT; | |
1da177e4 LT |
805 | |
806 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
807 | if (bp->b_pages) |
808 | _xfs_buf_free_pages(bp); | |
1da177e4 | 809 | |
ce8e922c NS |
810 | bp->b_pages = NULL; |
811 | bp->b_addr = mem; | |
1da177e4 | 812 | |
36fae17a | 813 | rval = _xfs_buf_get_pages(bp, page_count, XBF_DONT_BLOCK); |
1da177e4 LT |
814 | if (rval) |
815 | return rval; | |
816 | ||
ce8e922c | 817 | bp->b_offset = offset; |
d1afb678 LM |
818 | |
819 | for (i = 0; i < bp->b_page_count; i++) { | |
820 | bp->b_pages[i] = mem_to_page((void *)pageaddr); | |
821 | pageaddr += PAGE_CACHE_SIZE; | |
1da177e4 | 822 | } |
1da177e4 | 823 | |
d1afb678 LM |
824 | bp->b_count_desired = len; |
825 | bp->b_buffer_length = buflen; | |
ce8e922c | 826 | bp->b_flags |= XBF_MAPPED; |
6ab455ee | 827 | bp->b_flags &= ~_XBF_PAGE_LOCKED; |
1da177e4 LT |
828 | |
829 | return 0; | |
830 | } | |
831 | ||
832 | xfs_buf_t * | |
686865f7 DC |
833 | xfs_buf_get_uncached( |
834 | struct xfs_buftarg *target, | |
1da177e4 | 835 | size_t len, |
686865f7 | 836 | int flags) |
1da177e4 | 837 | { |
1fa40b01 CH |
838 | unsigned long page_count = PAGE_ALIGN(len) >> PAGE_SHIFT; |
839 | int error, i; | |
1da177e4 | 840 | xfs_buf_t *bp; |
1da177e4 | 841 | |
ce8e922c | 842 | bp = xfs_buf_allocate(0); |
1da177e4 LT |
843 | if (unlikely(bp == NULL)) |
844 | goto fail; | |
ce8e922c | 845 | _xfs_buf_initialize(bp, target, 0, len, 0); |
1da177e4 | 846 | |
1fa40b01 CH |
847 | error = _xfs_buf_get_pages(bp, page_count, 0); |
848 | if (error) | |
1da177e4 LT |
849 | goto fail_free_buf; |
850 | ||
1fa40b01 | 851 | for (i = 0; i < page_count; i++) { |
686865f7 | 852 | bp->b_pages[i] = alloc_page(xb_to_gfp(flags)); |
1fa40b01 CH |
853 | if (!bp->b_pages[i]) |
854 | goto fail_free_mem; | |
1da177e4 | 855 | } |
1fa40b01 | 856 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 857 | |
1fa40b01 CH |
858 | error = _xfs_buf_map_pages(bp, XBF_MAPPED); |
859 | if (unlikely(error)) { | |
4f10700a DC |
860 | xfs_warn(target->bt_mount, |
861 | "%s: failed to map pages\n", __func__); | |
1da177e4 | 862 | goto fail_free_mem; |
1fa40b01 | 863 | } |
1da177e4 | 864 | |
ce8e922c | 865 | xfs_buf_unlock(bp); |
1da177e4 | 866 | |
686865f7 | 867 | trace_xfs_buf_get_uncached(bp, _RET_IP_); |
1da177e4 | 868 | return bp; |
1fa40b01 | 869 | |
1da177e4 | 870 | fail_free_mem: |
1fa40b01 CH |
871 | while (--i >= 0) |
872 | __free_page(bp->b_pages[i]); | |
ca165b88 | 873 | _xfs_buf_free_pages(bp); |
1da177e4 | 874 | fail_free_buf: |
ca165b88 | 875 | xfs_buf_deallocate(bp); |
1da177e4 LT |
876 | fail: |
877 | return NULL; | |
878 | } | |
879 | ||
880 | /* | |
1da177e4 LT |
881 | * Increment reference count on buffer, to hold the buffer concurrently |
882 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
883 | * Must hold the buffer already to call this function. |
884 | */ | |
885 | void | |
ce8e922c NS |
886 | xfs_buf_hold( |
887 | xfs_buf_t *bp) | |
1da177e4 | 888 | { |
0b1b213f | 889 | trace_xfs_buf_hold(bp, _RET_IP_); |
ce8e922c | 890 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
891 | } |
892 | ||
893 | /* | |
ce8e922c NS |
894 | * Releases a hold on the specified buffer. If the |
895 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
896 | */ |
897 | void | |
ce8e922c NS |
898 | xfs_buf_rele( |
899 | xfs_buf_t *bp) | |
1da177e4 | 900 | { |
74f75a0c | 901 | struct xfs_perag *pag = bp->b_pag; |
1da177e4 | 902 | |
0b1b213f | 903 | trace_xfs_buf_rele(bp, _RET_IP_); |
1da177e4 | 904 | |
74f75a0c | 905 | if (!pag) { |
430cbeb8 | 906 | ASSERT(list_empty(&bp->b_lru)); |
74f75a0c | 907 | ASSERT(RB_EMPTY_NODE(&bp->b_rbnode)); |
fad3aa1e NS |
908 | if (atomic_dec_and_test(&bp->b_hold)) |
909 | xfs_buf_free(bp); | |
910 | return; | |
911 | } | |
912 | ||
74f75a0c | 913 | ASSERT(!RB_EMPTY_NODE(&bp->b_rbnode)); |
430cbeb8 | 914 | |
3790689f | 915 | ASSERT(atomic_read(&bp->b_hold) > 0); |
74f75a0c | 916 | if (atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock)) { |
bfc60177 | 917 | if (!(bp->b_flags & XBF_STALE) && |
430cbeb8 DC |
918 | atomic_read(&bp->b_lru_ref)) { |
919 | xfs_buf_lru_add(bp); | |
920 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 921 | } else { |
430cbeb8 | 922 | xfs_buf_lru_del(bp); |
ce8e922c | 923 | ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q))); |
74f75a0c DC |
924 | rb_erase(&bp->b_rbnode, &pag->pag_buf_tree); |
925 | spin_unlock(&pag->pag_buf_lock); | |
926 | xfs_perag_put(pag); | |
ce8e922c | 927 | xfs_buf_free(bp); |
1da177e4 LT |
928 | } |
929 | } | |
930 | } | |
931 | ||
932 | ||
933 | /* | |
934 | * Mutual exclusion on buffers. Locking model: | |
935 | * | |
936 | * Buffers associated with inodes for which buffer locking | |
937 | * is not enabled are not protected by semaphores, and are | |
938 | * assumed to be exclusively owned by the caller. There is a | |
939 | * spinlock in the buffer, used by the caller when concurrent | |
940 | * access is possible. | |
941 | */ | |
942 | ||
943 | /* | |
90810b9e DC |
944 | * Locks a buffer object, if it is not already locked. Note that this in |
945 | * no way locks the underlying pages, so it is only useful for | |
946 | * synchronizing concurrent use of buffer objects, not for synchronizing | |
947 | * independent access to the underlying pages. | |
948 | * | |
949 | * If we come across a stale, pinned, locked buffer, we know that we are | |
950 | * being asked to lock a buffer that has been reallocated. Because it is | |
951 | * pinned, we know that the log has not been pushed to disk and hence it | |
952 | * will still be locked. Rather than continuing to have trylock attempts | |
953 | * fail until someone else pushes the log, push it ourselves before | |
954 | * returning. This means that the xfsaild will not get stuck trying | |
955 | * to push on stale inode buffers. | |
1da177e4 LT |
956 | */ |
957 | int | |
ce8e922c NS |
958 | xfs_buf_cond_lock( |
959 | xfs_buf_t *bp) | |
1da177e4 LT |
960 | { |
961 | int locked; | |
962 | ||
ce8e922c | 963 | locked = down_trylock(&bp->b_sema) == 0; |
0b1b213f | 964 | if (locked) |
ce8e922c | 965 | XB_SET_OWNER(bp); |
90810b9e DC |
966 | else if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
967 | xfs_log_force(bp->b_target->bt_mount, 0); | |
0b1b213f CH |
968 | |
969 | trace_xfs_buf_cond_lock(bp, _RET_IP_); | |
ce8e922c | 970 | return locked ? 0 : -EBUSY; |
1da177e4 LT |
971 | } |
972 | ||
1da177e4 | 973 | int |
ce8e922c NS |
974 | xfs_buf_lock_value( |
975 | xfs_buf_t *bp) | |
1da177e4 | 976 | { |
adaa693b | 977 | return bp->b_sema.count; |
1da177e4 | 978 | } |
1da177e4 LT |
979 | |
980 | /* | |
ce8e922c NS |
981 | * Locks a buffer object. |
982 | * Note that this in no way locks the underlying pages, so it is only | |
983 | * useful for synchronizing concurrent use of buffer objects, not for | |
984 | * synchronizing independent access to the underlying pages. | |
ed3b4d6c DC |
985 | * |
986 | * If we come across a stale, pinned, locked buffer, we know that we | |
987 | * are being asked to lock a buffer that has been reallocated. Because | |
988 | * it is pinned, we know that the log has not been pushed to disk and | |
989 | * hence it will still be locked. Rather than sleeping until someone | |
990 | * else pushes the log, push it ourselves before trying to get the lock. | |
1da177e4 | 991 | */ |
ce8e922c NS |
992 | void |
993 | xfs_buf_lock( | |
994 | xfs_buf_t *bp) | |
1da177e4 | 995 | { |
0b1b213f CH |
996 | trace_xfs_buf_lock(bp, _RET_IP_); |
997 | ||
ed3b4d6c | 998 | if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
ebad861b | 999 | xfs_log_force(bp->b_target->bt_mount, 0); |
ce8e922c NS |
1000 | if (atomic_read(&bp->b_io_remaining)) |
1001 | blk_run_address_space(bp->b_target->bt_mapping); | |
1002 | down(&bp->b_sema); | |
1003 | XB_SET_OWNER(bp); | |
0b1b213f CH |
1004 | |
1005 | trace_xfs_buf_lock_done(bp, _RET_IP_); | |
1da177e4 LT |
1006 | } |
1007 | ||
1008 | /* | |
ce8e922c | 1009 | * Releases the lock on the buffer object. |
2f926587 | 1010 | * If the buffer is marked delwri but is not queued, do so before we |
ce8e922c | 1011 | * unlock the buffer as we need to set flags correctly. We also need to |
2f926587 DC |
1012 | * take a reference for the delwri queue because the unlocker is going to |
1013 | * drop their's and they don't know we just queued it. | |
1da177e4 LT |
1014 | */ |
1015 | void | |
ce8e922c NS |
1016 | xfs_buf_unlock( |
1017 | xfs_buf_t *bp) | |
1da177e4 | 1018 | { |
ce8e922c NS |
1019 | if ((bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)) == XBF_DELWRI) { |
1020 | atomic_inc(&bp->b_hold); | |
1021 | bp->b_flags |= XBF_ASYNC; | |
1022 | xfs_buf_delwri_queue(bp, 0); | |
2f926587 DC |
1023 | } |
1024 | ||
ce8e922c NS |
1025 | XB_CLEAR_OWNER(bp); |
1026 | up(&bp->b_sema); | |
0b1b213f CH |
1027 | |
1028 | trace_xfs_buf_unlock(bp, _RET_IP_); | |
1da177e4 LT |
1029 | } |
1030 | ||
ce8e922c NS |
1031 | STATIC void |
1032 | xfs_buf_wait_unpin( | |
1033 | xfs_buf_t *bp) | |
1da177e4 LT |
1034 | { |
1035 | DECLARE_WAITQUEUE (wait, current); | |
1036 | ||
ce8e922c | 1037 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
1038 | return; |
1039 | ||
ce8e922c | 1040 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1041 | for (;;) { |
1042 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 1043 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 1044 | break; |
ce8e922c NS |
1045 | if (atomic_read(&bp->b_io_remaining)) |
1046 | blk_run_address_space(bp->b_target->bt_mapping); | |
1da177e4 LT |
1047 | schedule(); |
1048 | } | |
ce8e922c | 1049 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1050 | set_current_state(TASK_RUNNING); |
1051 | } | |
1052 | ||
1053 | /* | |
1054 | * Buffer Utility Routines | |
1055 | */ | |
1056 | ||
1da177e4 | 1057 | STATIC void |
ce8e922c | 1058 | xfs_buf_iodone_work( |
c4028958 | 1059 | struct work_struct *work) |
1da177e4 | 1060 | { |
c4028958 DH |
1061 | xfs_buf_t *bp = |
1062 | container_of(work, xfs_buf_t, b_iodone_work); | |
1da177e4 | 1063 | |
80f6c29d | 1064 | if (bp->b_iodone) |
ce8e922c NS |
1065 | (*(bp->b_iodone))(bp); |
1066 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 LT |
1067 | xfs_buf_relse(bp); |
1068 | } | |
1069 | ||
1070 | void | |
ce8e922c NS |
1071 | xfs_buf_ioend( |
1072 | xfs_buf_t *bp, | |
1da177e4 LT |
1073 | int schedule) |
1074 | { | |
0b1b213f CH |
1075 | trace_xfs_buf_iodone(bp, _RET_IP_); |
1076 | ||
77be55a5 | 1077 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); |
ce8e922c NS |
1078 | if (bp->b_error == 0) |
1079 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1080 | |
ce8e922c | 1081 | if ((bp->b_iodone) || (bp->b_flags & XBF_ASYNC)) { |
1da177e4 | 1082 | if (schedule) { |
c4028958 | 1083 | INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work); |
ce8e922c | 1084 | queue_work(xfslogd_workqueue, &bp->b_iodone_work); |
1da177e4 | 1085 | } else { |
c4028958 | 1086 | xfs_buf_iodone_work(&bp->b_iodone_work); |
1da177e4 LT |
1087 | } |
1088 | } else { | |
b4dd330b | 1089 | complete(&bp->b_iowait); |
1da177e4 LT |
1090 | } |
1091 | } | |
1092 | ||
1da177e4 | 1093 | void |
ce8e922c NS |
1094 | xfs_buf_ioerror( |
1095 | xfs_buf_t *bp, | |
1096 | int error) | |
1da177e4 LT |
1097 | { |
1098 | ASSERT(error >= 0 && error <= 0xffff); | |
ce8e922c | 1099 | bp->b_error = (unsigned short)error; |
0b1b213f | 1100 | trace_xfs_buf_ioerror(bp, error, _RET_IP_); |
1da177e4 LT |
1101 | } |
1102 | ||
1da177e4 | 1103 | int |
64e0bc7d CH |
1104 | xfs_bwrite( |
1105 | struct xfs_mount *mp, | |
5d765b97 | 1106 | struct xfs_buf *bp) |
1da177e4 | 1107 | { |
8c38366f | 1108 | int error; |
1da177e4 | 1109 | |
64e0bc7d | 1110 | bp->b_flags |= XBF_WRITE; |
8c38366f | 1111 | bp->b_flags &= ~(XBF_ASYNC | XBF_READ); |
1da177e4 | 1112 | |
5d765b97 | 1113 | xfs_buf_delwri_dequeue(bp); |
939d723b | 1114 | xfs_bdstrat_cb(bp); |
1da177e4 | 1115 | |
8c38366f CH |
1116 | error = xfs_buf_iowait(bp); |
1117 | if (error) | |
1118 | xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR); | |
1119 | xfs_buf_relse(bp); | |
64e0bc7d | 1120 | return error; |
5d765b97 | 1121 | } |
1da177e4 | 1122 | |
5d765b97 CH |
1123 | void |
1124 | xfs_bdwrite( | |
1125 | void *mp, | |
1126 | struct xfs_buf *bp) | |
1127 | { | |
0b1b213f | 1128 | trace_xfs_buf_bdwrite(bp, _RET_IP_); |
1da177e4 | 1129 | |
5d765b97 CH |
1130 | bp->b_flags &= ~XBF_READ; |
1131 | bp->b_flags |= (XBF_DELWRI | XBF_ASYNC); | |
1132 | ||
1133 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1134 | } |
1135 | ||
4e23471a CH |
1136 | /* |
1137 | * Called when we want to stop a buffer from getting written or read. | |
1a1a3e97 | 1138 | * We attach the EIO error, muck with its flags, and call xfs_buf_ioend |
4e23471a CH |
1139 | * so that the proper iodone callbacks get called. |
1140 | */ | |
1141 | STATIC int | |
1142 | xfs_bioerror( | |
1143 | xfs_buf_t *bp) | |
1144 | { | |
1145 | #ifdef XFSERRORDEBUG | |
1146 | ASSERT(XFS_BUF_ISREAD(bp) || bp->b_iodone); | |
1147 | #endif | |
1148 | ||
1149 | /* | |
1150 | * No need to wait until the buffer is unpinned, we aren't flushing it. | |
1151 | */ | |
1152 | XFS_BUF_ERROR(bp, EIO); | |
1153 | ||
1154 | /* | |
1a1a3e97 | 1155 | * We're calling xfs_buf_ioend, so delete XBF_DONE flag. |
4e23471a CH |
1156 | */ |
1157 | XFS_BUF_UNREAD(bp); | |
1158 | XFS_BUF_UNDELAYWRITE(bp); | |
1159 | XFS_BUF_UNDONE(bp); | |
1160 | XFS_BUF_STALE(bp); | |
1161 | ||
1a1a3e97 | 1162 | xfs_buf_ioend(bp, 0); |
4e23471a CH |
1163 | |
1164 | return EIO; | |
1165 | } | |
1166 | ||
1167 | /* | |
1168 | * Same as xfs_bioerror, except that we are releasing the buffer | |
1a1a3e97 | 1169 | * here ourselves, and avoiding the xfs_buf_ioend call. |
4e23471a CH |
1170 | * This is meant for userdata errors; metadata bufs come with |
1171 | * iodone functions attached, so that we can track down errors. | |
1172 | */ | |
1173 | STATIC int | |
1174 | xfs_bioerror_relse( | |
1175 | struct xfs_buf *bp) | |
1176 | { | |
1177 | int64_t fl = XFS_BUF_BFLAGS(bp); | |
1178 | /* | |
1179 | * No need to wait until the buffer is unpinned. | |
1180 | * We aren't flushing it. | |
1181 | * | |
1182 | * chunkhold expects B_DONE to be set, whether | |
1183 | * we actually finish the I/O or not. We don't want to | |
1184 | * change that interface. | |
1185 | */ | |
1186 | XFS_BUF_UNREAD(bp); | |
1187 | XFS_BUF_UNDELAYWRITE(bp); | |
1188 | XFS_BUF_DONE(bp); | |
1189 | XFS_BUF_STALE(bp); | |
1190 | XFS_BUF_CLR_IODONE_FUNC(bp); | |
0cadda1c | 1191 | if (!(fl & XBF_ASYNC)) { |
4e23471a CH |
1192 | /* |
1193 | * Mark b_error and B_ERROR _both_. | |
1194 | * Lot's of chunkcache code assumes that. | |
1195 | * There's no reason to mark error for | |
1196 | * ASYNC buffers. | |
1197 | */ | |
1198 | XFS_BUF_ERROR(bp, EIO); | |
1199 | XFS_BUF_FINISH_IOWAIT(bp); | |
1200 | } else { | |
1201 | xfs_buf_relse(bp); | |
1202 | } | |
1203 | ||
1204 | return EIO; | |
1205 | } | |
1206 | ||
1207 | ||
1208 | /* | |
1209 | * All xfs metadata buffers except log state machine buffers | |
1210 | * get this attached as their b_bdstrat callback function. | |
1211 | * This is so that we can catch a buffer | |
1212 | * after prematurely unpinning it to forcibly shutdown the filesystem. | |
1213 | */ | |
1214 | int | |
1215 | xfs_bdstrat_cb( | |
1216 | struct xfs_buf *bp) | |
1217 | { | |
ebad861b | 1218 | if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) { |
4e23471a CH |
1219 | trace_xfs_bdstrat_shut(bp, _RET_IP_); |
1220 | /* | |
1221 | * Metadata write that didn't get logged but | |
1222 | * written delayed anyway. These aren't associated | |
1223 | * with a transaction, and can be ignored. | |
1224 | */ | |
1225 | if (!bp->b_iodone && !XFS_BUF_ISREAD(bp)) | |
1226 | return xfs_bioerror_relse(bp); | |
1227 | else | |
1228 | return xfs_bioerror(bp); | |
1229 | } | |
1230 | ||
1231 | xfs_buf_iorequest(bp); | |
1232 | return 0; | |
1233 | } | |
1234 | ||
1235 | /* | |
1236 | * Wrapper around bdstrat so that we can stop data from going to disk in case | |
1237 | * we are shutting down the filesystem. Typically user data goes thru this | |
1238 | * path; one of the exceptions is the superblock. | |
1239 | */ | |
1240 | void | |
1241 | xfsbdstrat( | |
1242 | struct xfs_mount *mp, | |
1243 | struct xfs_buf *bp) | |
1244 | { | |
1245 | if (XFS_FORCED_SHUTDOWN(mp)) { | |
1246 | trace_xfs_bdstrat_shut(bp, _RET_IP_); | |
1247 | xfs_bioerror_relse(bp); | |
1248 | return; | |
1249 | } | |
1250 | ||
1251 | xfs_buf_iorequest(bp); | |
1252 | } | |
1253 | ||
b8f82a4a | 1254 | STATIC void |
ce8e922c NS |
1255 | _xfs_buf_ioend( |
1256 | xfs_buf_t *bp, | |
1da177e4 LT |
1257 | int schedule) |
1258 | { | |
6ab455ee CH |
1259 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) { |
1260 | bp->b_flags &= ~_XBF_PAGE_LOCKED; | |
ce8e922c | 1261 | xfs_buf_ioend(bp, schedule); |
6ab455ee | 1262 | } |
1da177e4 LT |
1263 | } |
1264 | ||
782e3b3b | 1265 | STATIC void |
ce8e922c | 1266 | xfs_buf_bio_end_io( |
1da177e4 | 1267 | struct bio *bio, |
1da177e4 LT |
1268 | int error) |
1269 | { | |
ce8e922c NS |
1270 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1271 | unsigned int blocksize = bp->b_target->bt_bsize; | |
eedb5530 | 1272 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; |
1da177e4 | 1273 | |
cfbe5267 | 1274 | xfs_buf_ioerror(bp, -error); |
1da177e4 | 1275 | |
73c77e2c JB |
1276 | if (!error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ)) |
1277 | invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp)); | |
1278 | ||
eedb5530 | 1279 | do { |
1da177e4 LT |
1280 | struct page *page = bvec->bv_page; |
1281 | ||
948ecdb4 | 1282 | ASSERT(!PagePrivate(page)); |
ce8e922c NS |
1283 | if (unlikely(bp->b_error)) { |
1284 | if (bp->b_flags & XBF_READ) | |
eedb5530 | 1285 | ClearPageUptodate(page); |
ce8e922c | 1286 | } else if (blocksize >= PAGE_CACHE_SIZE) { |
1da177e4 LT |
1287 | SetPageUptodate(page); |
1288 | } else if (!PagePrivate(page) && | |
ce8e922c | 1289 | (bp->b_flags & _XBF_PAGE_CACHE)) { |
1da177e4 LT |
1290 | set_page_region(page, bvec->bv_offset, bvec->bv_len); |
1291 | } | |
1292 | ||
eedb5530 NS |
1293 | if (--bvec >= bio->bi_io_vec) |
1294 | prefetchw(&bvec->bv_page->flags); | |
6ab455ee CH |
1295 | |
1296 | if (bp->b_flags & _XBF_PAGE_LOCKED) | |
1297 | unlock_page(page); | |
eedb5530 | 1298 | } while (bvec >= bio->bi_io_vec); |
1da177e4 | 1299 | |
ce8e922c | 1300 | _xfs_buf_ioend(bp, 1); |
1da177e4 | 1301 | bio_put(bio); |
1da177e4 LT |
1302 | } |
1303 | ||
1304 | STATIC void | |
ce8e922c NS |
1305 | _xfs_buf_ioapply( |
1306 | xfs_buf_t *bp) | |
1da177e4 | 1307 | { |
a9759f2d | 1308 | int rw, map_i, total_nr_pages, nr_pages; |
1da177e4 | 1309 | struct bio *bio; |
ce8e922c NS |
1310 | int offset = bp->b_offset; |
1311 | int size = bp->b_count_desired; | |
1312 | sector_t sector = bp->b_bn; | |
1313 | unsigned int blocksize = bp->b_target->bt_bsize; | |
1da177e4 | 1314 | |
ce8e922c | 1315 | total_nr_pages = bp->b_page_count; |
1da177e4 LT |
1316 | map_i = 0; |
1317 | ||
ce8e922c NS |
1318 | if (bp->b_flags & XBF_ORDERED) { |
1319 | ASSERT(!(bp->b_flags & XBF_READ)); | |
80f6c29d | 1320 | rw = WRITE_FLUSH_FUA; |
2ee1abad | 1321 | } else if (bp->b_flags & XBF_LOG_BUFFER) { |
51bdd706 NS |
1322 | ASSERT(!(bp->b_flags & XBF_READ_AHEAD)); |
1323 | bp->b_flags &= ~_XBF_RUN_QUEUES; | |
1324 | rw = (bp->b_flags & XBF_WRITE) ? WRITE_SYNC : READ_SYNC; | |
2ee1abad DC |
1325 | } else if (bp->b_flags & _XBF_RUN_QUEUES) { |
1326 | ASSERT(!(bp->b_flags & XBF_READ_AHEAD)); | |
1327 | bp->b_flags &= ~_XBF_RUN_QUEUES; | |
1328 | rw = (bp->b_flags & XBF_WRITE) ? WRITE_META : READ_META; | |
51bdd706 NS |
1329 | } else { |
1330 | rw = (bp->b_flags & XBF_WRITE) ? WRITE : | |
1331 | (bp->b_flags & XBF_READ_AHEAD) ? READA : READ; | |
f538d4da CH |
1332 | } |
1333 | ||
ce8e922c | 1334 | /* Special code path for reading a sub page size buffer in -- |
1da177e4 LT |
1335 | * we populate up the whole page, and hence the other metadata |
1336 | * in the same page. This optimization is only valid when the | |
ce8e922c | 1337 | * filesystem block size is not smaller than the page size. |
1da177e4 | 1338 | */ |
ce8e922c | 1339 | if ((bp->b_buffer_length < PAGE_CACHE_SIZE) && |
6ab455ee CH |
1340 | ((bp->b_flags & (XBF_READ|_XBF_PAGE_LOCKED)) == |
1341 | (XBF_READ|_XBF_PAGE_LOCKED)) && | |
ce8e922c | 1342 | (blocksize >= PAGE_CACHE_SIZE)) { |
1da177e4 LT |
1343 | bio = bio_alloc(GFP_NOIO, 1); |
1344 | ||
ce8e922c | 1345 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1346 | bio->bi_sector = sector - (offset >> BBSHIFT); |
ce8e922c NS |
1347 | bio->bi_end_io = xfs_buf_bio_end_io; |
1348 | bio->bi_private = bp; | |
1da177e4 | 1349 | |
ce8e922c | 1350 | bio_add_page(bio, bp->b_pages[0], PAGE_CACHE_SIZE, 0); |
1da177e4 LT |
1351 | size = 0; |
1352 | ||
ce8e922c | 1353 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1354 | |
1355 | goto submit_io; | |
1356 | } | |
1357 | ||
1da177e4 | 1358 | next_chunk: |
ce8e922c | 1359 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1360 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1361 | if (nr_pages > total_nr_pages) | |
1362 | nr_pages = total_nr_pages; | |
1363 | ||
1364 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1365 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1366 | bio->bi_sector = sector; |
ce8e922c NS |
1367 | bio->bi_end_io = xfs_buf_bio_end_io; |
1368 | bio->bi_private = bp; | |
1da177e4 LT |
1369 | |
1370 | for (; size && nr_pages; nr_pages--, map_i++) { | |
ce8e922c | 1371 | int rbytes, nbytes = PAGE_CACHE_SIZE - offset; |
1da177e4 LT |
1372 | |
1373 | if (nbytes > size) | |
1374 | nbytes = size; | |
1375 | ||
ce8e922c NS |
1376 | rbytes = bio_add_page(bio, bp->b_pages[map_i], nbytes, offset); |
1377 | if (rbytes < nbytes) | |
1da177e4 LT |
1378 | break; |
1379 | ||
1380 | offset = 0; | |
1381 | sector += nbytes >> BBSHIFT; | |
1382 | size -= nbytes; | |
1383 | total_nr_pages--; | |
1384 | } | |
1385 | ||
1386 | submit_io: | |
1387 | if (likely(bio->bi_size)) { | |
73c77e2c JB |
1388 | if (xfs_buf_is_vmapped(bp)) { |
1389 | flush_kernel_vmap_range(bp->b_addr, | |
1390 | xfs_buf_vmap_len(bp)); | |
1391 | } | |
1da177e4 LT |
1392 | submit_bio(rw, bio); |
1393 | if (size) | |
1394 | goto next_chunk; | |
1395 | } else { | |
ec53d1db DC |
1396 | /* |
1397 | * if we get here, no pages were added to the bio. However, | |
1398 | * we can't just error out here - if the pages are locked then | |
1399 | * we have to unlock them otherwise we can hang on a later | |
1400 | * access to the page. | |
1401 | */ | |
ce8e922c | 1402 | xfs_buf_ioerror(bp, EIO); |
ec53d1db DC |
1403 | if (bp->b_flags & _XBF_PAGE_LOCKED) { |
1404 | int i; | |
1405 | for (i = 0; i < bp->b_page_count; i++) | |
1406 | unlock_page(bp->b_pages[i]); | |
1407 | } | |
1408 | bio_put(bio); | |
1da177e4 LT |
1409 | } |
1410 | } | |
1411 | ||
1da177e4 | 1412 | int |
ce8e922c NS |
1413 | xfs_buf_iorequest( |
1414 | xfs_buf_t *bp) | |
1da177e4 | 1415 | { |
0b1b213f | 1416 | trace_xfs_buf_iorequest(bp, _RET_IP_); |
1da177e4 | 1417 | |
ce8e922c NS |
1418 | if (bp->b_flags & XBF_DELWRI) { |
1419 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1420 | return 0; |
1421 | } | |
1422 | ||
ce8e922c NS |
1423 | if (bp->b_flags & XBF_WRITE) { |
1424 | xfs_buf_wait_unpin(bp); | |
1da177e4 LT |
1425 | } |
1426 | ||
ce8e922c | 1427 | xfs_buf_hold(bp); |
1da177e4 LT |
1428 | |
1429 | /* Set the count to 1 initially, this will stop an I/O | |
1430 | * completion callout which happens before we have started | |
ce8e922c | 1431 | * all the I/O from calling xfs_buf_ioend too early. |
1da177e4 | 1432 | */ |
ce8e922c NS |
1433 | atomic_set(&bp->b_io_remaining, 1); |
1434 | _xfs_buf_ioapply(bp); | |
1435 | _xfs_buf_ioend(bp, 0); | |
1da177e4 | 1436 | |
ce8e922c | 1437 | xfs_buf_rele(bp); |
1da177e4 LT |
1438 | return 0; |
1439 | } | |
1440 | ||
1441 | /* | |
ce8e922c NS |
1442 | * Waits for I/O to complete on the buffer supplied. |
1443 | * It returns immediately if no I/O is pending. | |
1444 | * It returns the I/O error code, if any, or 0 if there was no error. | |
1da177e4 LT |
1445 | */ |
1446 | int | |
ce8e922c NS |
1447 | xfs_buf_iowait( |
1448 | xfs_buf_t *bp) | |
1da177e4 | 1449 | { |
0b1b213f CH |
1450 | trace_xfs_buf_iowait(bp, _RET_IP_); |
1451 | ||
ce8e922c NS |
1452 | if (atomic_read(&bp->b_io_remaining)) |
1453 | blk_run_address_space(bp->b_target->bt_mapping); | |
b4dd330b | 1454 | wait_for_completion(&bp->b_iowait); |
0b1b213f CH |
1455 | |
1456 | trace_xfs_buf_iowait_done(bp, _RET_IP_); | |
ce8e922c | 1457 | return bp->b_error; |
1da177e4 LT |
1458 | } |
1459 | ||
ce8e922c NS |
1460 | xfs_caddr_t |
1461 | xfs_buf_offset( | |
1462 | xfs_buf_t *bp, | |
1da177e4 LT |
1463 | size_t offset) |
1464 | { | |
1465 | struct page *page; | |
1466 | ||
ce8e922c NS |
1467 | if (bp->b_flags & XBF_MAPPED) |
1468 | return XFS_BUF_PTR(bp) + offset; | |
1da177e4 | 1469 | |
ce8e922c NS |
1470 | offset += bp->b_offset; |
1471 | page = bp->b_pages[offset >> PAGE_CACHE_SHIFT]; | |
1472 | return (xfs_caddr_t)page_address(page) + (offset & (PAGE_CACHE_SIZE-1)); | |
1da177e4 LT |
1473 | } |
1474 | ||
1475 | /* | |
1da177e4 LT |
1476 | * Move data into or out of a buffer. |
1477 | */ | |
1478 | void | |
ce8e922c NS |
1479 | xfs_buf_iomove( |
1480 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1481 | size_t boff, /* starting buffer offset */ |
1482 | size_t bsize, /* length to copy */ | |
b9c48649 | 1483 | void *data, /* data address */ |
ce8e922c | 1484 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 LT |
1485 | { |
1486 | size_t bend, cpoff, csize; | |
1487 | struct page *page; | |
1488 | ||
1489 | bend = boff + bsize; | |
1490 | while (boff < bend) { | |
ce8e922c NS |
1491 | page = bp->b_pages[xfs_buf_btoct(boff + bp->b_offset)]; |
1492 | cpoff = xfs_buf_poff(boff + bp->b_offset); | |
1da177e4 | 1493 | csize = min_t(size_t, |
ce8e922c | 1494 | PAGE_CACHE_SIZE-cpoff, bp->b_count_desired-boff); |
1da177e4 LT |
1495 | |
1496 | ASSERT(((csize + cpoff) <= PAGE_CACHE_SIZE)); | |
1497 | ||
1498 | switch (mode) { | |
ce8e922c | 1499 | case XBRW_ZERO: |
1da177e4 LT |
1500 | memset(page_address(page) + cpoff, 0, csize); |
1501 | break; | |
ce8e922c | 1502 | case XBRW_READ: |
1da177e4 LT |
1503 | memcpy(data, page_address(page) + cpoff, csize); |
1504 | break; | |
ce8e922c | 1505 | case XBRW_WRITE: |
1da177e4 LT |
1506 | memcpy(page_address(page) + cpoff, data, csize); |
1507 | } | |
1508 | ||
1509 | boff += csize; | |
1510 | data += csize; | |
1511 | } | |
1512 | } | |
1513 | ||
1514 | /* | |
ce8e922c | 1515 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1516 | */ |
1517 | ||
1518 | /* | |
430cbeb8 DC |
1519 | * Wait for any bufs with callbacks that have been submitted but have not yet |
1520 | * returned. These buffers will have an elevated hold count, so wait on those | |
1521 | * while freeing all the buffers only held by the LRU. | |
1da177e4 LT |
1522 | */ |
1523 | void | |
1524 | xfs_wait_buftarg( | |
74f75a0c | 1525 | struct xfs_buftarg *btp) |
1da177e4 | 1526 | { |
430cbeb8 DC |
1527 | struct xfs_buf *bp; |
1528 | ||
1529 | restart: | |
1530 | spin_lock(&btp->bt_lru_lock); | |
1531 | while (!list_empty(&btp->bt_lru)) { | |
1532 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1533 | if (atomic_read(&bp->b_hold) > 1) { | |
1534 | spin_unlock(&btp->bt_lru_lock); | |
26af6552 | 1535 | delay(100); |
430cbeb8 | 1536 | goto restart; |
1da177e4 | 1537 | } |
430cbeb8 DC |
1538 | /* |
1539 | * clear the LRU reference count so the bufer doesn't get | |
1540 | * ignored in xfs_buf_rele(). | |
1541 | */ | |
1542 | atomic_set(&bp->b_lru_ref, 0); | |
1543 | spin_unlock(&btp->bt_lru_lock); | |
1544 | xfs_buf_rele(bp); | |
1545 | spin_lock(&btp->bt_lru_lock); | |
1da177e4 | 1546 | } |
430cbeb8 | 1547 | spin_unlock(&btp->bt_lru_lock); |
1da177e4 LT |
1548 | } |
1549 | ||
ff57ab21 DC |
1550 | int |
1551 | xfs_buftarg_shrink( | |
1552 | struct shrinker *shrink, | |
1553 | int nr_to_scan, | |
1554 | gfp_t mask) | |
a6867a68 | 1555 | { |
ff57ab21 DC |
1556 | struct xfs_buftarg *btp = container_of(shrink, |
1557 | struct xfs_buftarg, bt_shrinker); | |
430cbeb8 DC |
1558 | struct xfs_buf *bp; |
1559 | LIST_HEAD(dispose); | |
1560 | ||
1561 | if (!nr_to_scan) | |
1562 | return btp->bt_lru_nr; | |
1563 | ||
1564 | spin_lock(&btp->bt_lru_lock); | |
1565 | while (!list_empty(&btp->bt_lru)) { | |
1566 | if (nr_to_scan-- <= 0) | |
1567 | break; | |
1568 | ||
1569 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1570 | ||
1571 | /* | |
1572 | * Decrement the b_lru_ref count unless the value is already | |
1573 | * zero. If the value is already zero, we need to reclaim the | |
1574 | * buffer, otherwise it gets another trip through the LRU. | |
1575 | */ | |
1576 | if (!atomic_add_unless(&bp->b_lru_ref, -1, 0)) { | |
1577 | list_move_tail(&bp->b_lru, &btp->bt_lru); | |
1578 | continue; | |
1579 | } | |
1580 | ||
1581 | /* | |
1582 | * remove the buffer from the LRU now to avoid needing another | |
1583 | * lock round trip inside xfs_buf_rele(). | |
1584 | */ | |
1585 | list_move(&bp->b_lru, &dispose); | |
1586 | btp->bt_lru_nr--; | |
ff57ab21 | 1587 | } |
430cbeb8 DC |
1588 | spin_unlock(&btp->bt_lru_lock); |
1589 | ||
1590 | while (!list_empty(&dispose)) { | |
1591 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); | |
1592 | list_del_init(&bp->b_lru); | |
1593 | xfs_buf_rele(bp); | |
1594 | } | |
1595 | ||
1596 | return btp->bt_lru_nr; | |
a6867a68 DC |
1597 | } |
1598 | ||
1da177e4 LT |
1599 | void |
1600 | xfs_free_buftarg( | |
b7963133 CH |
1601 | struct xfs_mount *mp, |
1602 | struct xfs_buftarg *btp) | |
1da177e4 | 1603 | { |
ff57ab21 DC |
1604 | unregister_shrinker(&btp->bt_shrinker); |
1605 | ||
1da177e4 | 1606 | xfs_flush_buftarg(btp, 1); |
b7963133 CH |
1607 | if (mp->m_flags & XFS_MOUNT_BARRIER) |
1608 | xfs_blkdev_issue_flush(btp); | |
ce8e922c | 1609 | iput(btp->bt_mapping->host); |
a6867a68 | 1610 | |
a6867a68 | 1611 | kthread_stop(btp->bt_task); |
f0e2d93c | 1612 | kmem_free(btp); |
1da177e4 LT |
1613 | } |
1614 | ||
1da177e4 LT |
1615 | STATIC int |
1616 | xfs_setsize_buftarg_flags( | |
1617 | xfs_buftarg_t *btp, | |
1618 | unsigned int blocksize, | |
1619 | unsigned int sectorsize, | |
1620 | int verbose) | |
1621 | { | |
ce8e922c NS |
1622 | btp->bt_bsize = blocksize; |
1623 | btp->bt_sshift = ffs(sectorsize) - 1; | |
1624 | btp->bt_smask = sectorsize - 1; | |
1da177e4 | 1625 | |
ce8e922c | 1626 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
4f10700a DC |
1627 | xfs_warn(btp->bt_mount, |
1628 | "Cannot set_blocksize to %u on device %s\n", | |
1da177e4 LT |
1629 | sectorsize, XFS_BUFTARG_NAME(btp)); |
1630 | return EINVAL; | |
1631 | } | |
1632 | ||
1633 | if (verbose && | |
1634 | (PAGE_CACHE_SIZE / BITS_PER_LONG) > sectorsize) { | |
1635 | printk(KERN_WARNING | |
1636 | "XFS: %u byte sectors in use on device %s. " | |
1637 | "This is suboptimal; %u or greater is ideal.\n", | |
1638 | sectorsize, XFS_BUFTARG_NAME(btp), | |
1639 | (unsigned int)PAGE_CACHE_SIZE / BITS_PER_LONG); | |
1640 | } | |
1641 | ||
1642 | return 0; | |
1643 | } | |
1644 | ||
1645 | /* | |
ce8e922c NS |
1646 | * When allocating the initial buffer target we have not yet |
1647 | * read in the superblock, so don't know what sized sectors | |
1648 | * are being used is at this early stage. Play safe. | |
1649 | */ | |
1da177e4 LT |
1650 | STATIC int |
1651 | xfs_setsize_buftarg_early( | |
1652 | xfs_buftarg_t *btp, | |
1653 | struct block_device *bdev) | |
1654 | { | |
1655 | return xfs_setsize_buftarg_flags(btp, | |
e1defc4f | 1656 | PAGE_CACHE_SIZE, bdev_logical_block_size(bdev), 0); |
1da177e4 LT |
1657 | } |
1658 | ||
1659 | int | |
1660 | xfs_setsize_buftarg( | |
1661 | xfs_buftarg_t *btp, | |
1662 | unsigned int blocksize, | |
1663 | unsigned int sectorsize) | |
1664 | { | |
1665 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | |
1666 | } | |
1667 | ||
1668 | STATIC int | |
1669 | xfs_mapping_buftarg( | |
1670 | xfs_buftarg_t *btp, | |
1671 | struct block_device *bdev) | |
1672 | { | |
1673 | struct backing_dev_info *bdi; | |
1674 | struct inode *inode; | |
1675 | struct address_space *mapping; | |
f5e54d6e | 1676 | static const struct address_space_operations mapping_aops = { |
1da177e4 | 1677 | .sync_page = block_sync_page, |
e965f963 | 1678 | .migratepage = fail_migrate_page, |
1da177e4 LT |
1679 | }; |
1680 | ||
1681 | inode = new_inode(bdev->bd_inode->i_sb); | |
1682 | if (!inode) { | |
1683 | printk(KERN_WARNING | |
1684 | "XFS: Cannot allocate mapping inode for device %s\n", | |
1685 | XFS_BUFTARG_NAME(btp)); | |
1686 | return ENOMEM; | |
1687 | } | |
85fe4025 | 1688 | inode->i_ino = get_next_ino(); |
1da177e4 LT |
1689 | inode->i_mode = S_IFBLK; |
1690 | inode->i_bdev = bdev; | |
1691 | inode->i_rdev = bdev->bd_dev; | |
1692 | bdi = blk_get_backing_dev_info(bdev); | |
1693 | if (!bdi) | |
1694 | bdi = &default_backing_dev_info; | |
1695 | mapping = &inode->i_data; | |
1696 | mapping->a_ops = &mapping_aops; | |
1697 | mapping->backing_dev_info = bdi; | |
1698 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
ce8e922c | 1699 | btp->bt_mapping = mapping; |
1da177e4 LT |
1700 | return 0; |
1701 | } | |
1702 | ||
a6867a68 DC |
1703 | STATIC int |
1704 | xfs_alloc_delwrite_queue( | |
e2a07812 JE |
1705 | xfs_buftarg_t *btp, |
1706 | const char *fsname) | |
a6867a68 | 1707 | { |
a6867a68 | 1708 | INIT_LIST_HEAD(&btp->bt_delwrite_queue); |
007c61c6 | 1709 | spin_lock_init(&btp->bt_delwrite_lock); |
a6867a68 | 1710 | btp->bt_flags = 0; |
e2a07812 | 1711 | btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd/%s", fsname); |
ff57ab21 DC |
1712 | if (IS_ERR(btp->bt_task)) |
1713 | return PTR_ERR(btp->bt_task); | |
1714 | return 0; | |
a6867a68 DC |
1715 | } |
1716 | ||
1da177e4 LT |
1717 | xfs_buftarg_t * |
1718 | xfs_alloc_buftarg( | |
ebad861b | 1719 | struct xfs_mount *mp, |
1da177e4 | 1720 | struct block_device *bdev, |
e2a07812 JE |
1721 | int external, |
1722 | const char *fsname) | |
1da177e4 LT |
1723 | { |
1724 | xfs_buftarg_t *btp; | |
1725 | ||
1726 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP); | |
1727 | ||
ebad861b | 1728 | btp->bt_mount = mp; |
ce8e922c NS |
1729 | btp->bt_dev = bdev->bd_dev; |
1730 | btp->bt_bdev = bdev; | |
430cbeb8 DC |
1731 | INIT_LIST_HEAD(&btp->bt_lru); |
1732 | spin_lock_init(&btp->bt_lru_lock); | |
1da177e4 LT |
1733 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1734 | goto error; | |
1735 | if (xfs_mapping_buftarg(btp, bdev)) | |
1736 | goto error; | |
e2a07812 | 1737 | if (xfs_alloc_delwrite_queue(btp, fsname)) |
a6867a68 | 1738 | goto error; |
ff57ab21 DC |
1739 | btp->bt_shrinker.shrink = xfs_buftarg_shrink; |
1740 | btp->bt_shrinker.seeks = DEFAULT_SEEKS; | |
1741 | register_shrinker(&btp->bt_shrinker); | |
1da177e4 LT |
1742 | return btp; |
1743 | ||
1744 | error: | |
f0e2d93c | 1745 | kmem_free(btp); |
1da177e4 LT |
1746 | return NULL; |
1747 | } | |
1748 | ||
1749 | ||
1750 | /* | |
ce8e922c | 1751 | * Delayed write buffer handling |
1da177e4 | 1752 | */ |
1da177e4 | 1753 | STATIC void |
ce8e922c NS |
1754 | xfs_buf_delwri_queue( |
1755 | xfs_buf_t *bp, | |
1da177e4 LT |
1756 | int unlock) |
1757 | { | |
ce8e922c NS |
1758 | struct list_head *dwq = &bp->b_target->bt_delwrite_queue; |
1759 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; | |
a6867a68 | 1760 | |
0b1b213f CH |
1761 | trace_xfs_buf_delwri_queue(bp, _RET_IP_); |
1762 | ||
ce8e922c | 1763 | ASSERT((bp->b_flags&(XBF_DELWRI|XBF_ASYNC)) == (XBF_DELWRI|XBF_ASYNC)); |
1da177e4 | 1764 | |
a6867a68 | 1765 | spin_lock(dwlk); |
1da177e4 | 1766 | /* If already in the queue, dequeue and place at tail */ |
ce8e922c NS |
1767 | if (!list_empty(&bp->b_list)) { |
1768 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1769 | if (unlock) | |
1770 | atomic_dec(&bp->b_hold); | |
1771 | list_del(&bp->b_list); | |
1da177e4 LT |
1772 | } |
1773 | ||
c9c12971 DC |
1774 | if (list_empty(dwq)) { |
1775 | /* start xfsbufd as it is about to have something to do */ | |
1776 | wake_up_process(bp->b_target->bt_task); | |
1777 | } | |
1778 | ||
ce8e922c NS |
1779 | bp->b_flags |= _XBF_DELWRI_Q; |
1780 | list_add_tail(&bp->b_list, dwq); | |
1781 | bp->b_queuetime = jiffies; | |
a6867a68 | 1782 | spin_unlock(dwlk); |
1da177e4 LT |
1783 | |
1784 | if (unlock) | |
ce8e922c | 1785 | xfs_buf_unlock(bp); |
1da177e4 LT |
1786 | } |
1787 | ||
1788 | void | |
ce8e922c NS |
1789 | xfs_buf_delwri_dequeue( |
1790 | xfs_buf_t *bp) | |
1da177e4 | 1791 | { |
ce8e922c | 1792 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; |
1da177e4 LT |
1793 | int dequeued = 0; |
1794 | ||
a6867a68 | 1795 | spin_lock(dwlk); |
ce8e922c NS |
1796 | if ((bp->b_flags & XBF_DELWRI) && !list_empty(&bp->b_list)) { |
1797 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1798 | list_del_init(&bp->b_list); | |
1da177e4 LT |
1799 | dequeued = 1; |
1800 | } | |
ce8e922c | 1801 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); |
a6867a68 | 1802 | spin_unlock(dwlk); |
1da177e4 LT |
1803 | |
1804 | if (dequeued) | |
ce8e922c | 1805 | xfs_buf_rele(bp); |
1da177e4 | 1806 | |
0b1b213f | 1807 | trace_xfs_buf_delwri_dequeue(bp, _RET_IP_); |
1da177e4 LT |
1808 | } |
1809 | ||
d808f617 DC |
1810 | /* |
1811 | * If a delwri buffer needs to be pushed before it has aged out, then promote | |
1812 | * it to the head of the delwri queue so that it will be flushed on the next | |
1813 | * xfsbufd run. We do this by resetting the queuetime of the buffer to be older | |
1814 | * than the age currently needed to flush the buffer. Hence the next time the | |
1815 | * xfsbufd sees it is guaranteed to be considered old enough to flush. | |
1816 | */ | |
1817 | void | |
1818 | xfs_buf_delwri_promote( | |
1819 | struct xfs_buf *bp) | |
1820 | { | |
1821 | struct xfs_buftarg *btp = bp->b_target; | |
1822 | long age = xfs_buf_age_centisecs * msecs_to_jiffies(10) + 1; | |
1823 | ||
1824 | ASSERT(bp->b_flags & XBF_DELWRI); | |
1825 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1826 | ||
1827 | /* | |
1828 | * Check the buffer age before locking the delayed write queue as we | |
1829 | * don't need to promote buffers that are already past the flush age. | |
1830 | */ | |
1831 | if (bp->b_queuetime < jiffies - age) | |
1832 | return; | |
1833 | bp->b_queuetime = jiffies - age; | |
1834 | spin_lock(&btp->bt_delwrite_lock); | |
1835 | list_move(&bp->b_list, &btp->bt_delwrite_queue); | |
1836 | spin_unlock(&btp->bt_delwrite_lock); | |
1837 | } | |
1838 | ||
1da177e4 | 1839 | STATIC void |
ce8e922c | 1840 | xfs_buf_runall_queues( |
1da177e4 LT |
1841 | struct workqueue_struct *queue) |
1842 | { | |
1843 | flush_workqueue(queue); | |
1844 | } | |
1845 | ||
585e6d88 DC |
1846 | /* |
1847 | * Move as many buffers as specified to the supplied list | |
1848 | * idicating if we skipped any buffers to prevent deadlocks. | |
1849 | */ | |
1850 | STATIC int | |
1851 | xfs_buf_delwri_split( | |
1852 | xfs_buftarg_t *target, | |
1853 | struct list_head *list, | |
5e6a07df | 1854 | unsigned long age) |
585e6d88 DC |
1855 | { |
1856 | xfs_buf_t *bp, *n; | |
1857 | struct list_head *dwq = &target->bt_delwrite_queue; | |
1858 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1859 | int skipped = 0; | |
5e6a07df | 1860 | int force; |
585e6d88 | 1861 | |
5e6a07df | 1862 | force = test_and_clear_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
585e6d88 DC |
1863 | INIT_LIST_HEAD(list); |
1864 | spin_lock(dwlk); | |
1865 | list_for_each_entry_safe(bp, n, dwq, b_list) { | |
585e6d88 DC |
1866 | ASSERT(bp->b_flags & XBF_DELWRI); |
1867 | ||
4d16e924 | 1868 | if (!XFS_BUF_ISPINNED(bp) && !xfs_buf_cond_lock(bp)) { |
5e6a07df | 1869 | if (!force && |
585e6d88 DC |
1870 | time_before(jiffies, bp->b_queuetime + age)) { |
1871 | xfs_buf_unlock(bp); | |
1872 | break; | |
1873 | } | |
1874 | ||
1875 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q| | |
1876 | _XBF_RUN_QUEUES); | |
1877 | bp->b_flags |= XBF_WRITE; | |
1878 | list_move_tail(&bp->b_list, list); | |
bfe27419 | 1879 | trace_xfs_buf_delwri_split(bp, _RET_IP_); |
585e6d88 DC |
1880 | } else |
1881 | skipped++; | |
1882 | } | |
1883 | spin_unlock(dwlk); | |
1884 | ||
1885 | return skipped; | |
1886 | ||
1887 | } | |
1888 | ||
089716aa DC |
1889 | /* |
1890 | * Compare function is more complex than it needs to be because | |
1891 | * the return value is only 32 bits and we are doing comparisons | |
1892 | * on 64 bit values | |
1893 | */ | |
1894 | static int | |
1895 | xfs_buf_cmp( | |
1896 | void *priv, | |
1897 | struct list_head *a, | |
1898 | struct list_head *b) | |
1899 | { | |
1900 | struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list); | |
1901 | struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); | |
1902 | xfs_daddr_t diff; | |
1903 | ||
1904 | diff = ap->b_bn - bp->b_bn; | |
1905 | if (diff < 0) | |
1906 | return -1; | |
1907 | if (diff > 0) | |
1908 | return 1; | |
1909 | return 0; | |
1910 | } | |
1911 | ||
1912 | void | |
1913 | xfs_buf_delwri_sort( | |
1914 | xfs_buftarg_t *target, | |
1915 | struct list_head *list) | |
1916 | { | |
1917 | list_sort(NULL, list, xfs_buf_cmp); | |
1918 | } | |
1919 | ||
1da177e4 | 1920 | STATIC int |
23ea4032 | 1921 | xfsbufd( |
585e6d88 | 1922 | void *data) |
1da177e4 | 1923 | { |
089716aa | 1924 | xfs_buftarg_t *target = (xfs_buftarg_t *)data; |
1da177e4 | 1925 | |
1da177e4 LT |
1926 | current->flags |= PF_MEMALLOC; |
1927 | ||
978c7b2f RW |
1928 | set_freezable(); |
1929 | ||
1da177e4 | 1930 | do { |
c9c12971 DC |
1931 | long age = xfs_buf_age_centisecs * msecs_to_jiffies(10); |
1932 | long tout = xfs_buf_timer_centisecs * msecs_to_jiffies(10); | |
089716aa DC |
1933 | int count = 0; |
1934 | struct list_head tmp; | |
c9c12971 | 1935 | |
3e1d1d28 | 1936 | if (unlikely(freezing(current))) { |
ce8e922c | 1937 | set_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
3e1d1d28 | 1938 | refrigerator(); |
abd0cf7a | 1939 | } else { |
ce8e922c | 1940 | clear_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
abd0cf7a | 1941 | } |
1da177e4 | 1942 | |
c9c12971 DC |
1943 | /* sleep for a long time if there is nothing to do. */ |
1944 | if (list_empty(&target->bt_delwrite_queue)) | |
1945 | tout = MAX_SCHEDULE_TIMEOUT; | |
1946 | schedule_timeout_interruptible(tout); | |
1da177e4 | 1947 | |
c9c12971 | 1948 | xfs_buf_delwri_split(target, &tmp, age); |
089716aa | 1949 | list_sort(NULL, &tmp, xfs_buf_cmp); |
1da177e4 | 1950 | while (!list_empty(&tmp)) { |
089716aa DC |
1951 | struct xfs_buf *bp; |
1952 | bp = list_first_entry(&tmp, struct xfs_buf, b_list); | |
ce8e922c | 1953 | list_del_init(&bp->b_list); |
939d723b | 1954 | xfs_bdstrat_cb(bp); |
585e6d88 | 1955 | count++; |
1da177e4 | 1956 | } |
f07c2250 NS |
1957 | if (count) |
1958 | blk_run_address_space(target->bt_mapping); | |
1da177e4 | 1959 | |
4df08c52 | 1960 | } while (!kthread_should_stop()); |
1da177e4 | 1961 | |
4df08c52 | 1962 | return 0; |
1da177e4 LT |
1963 | } |
1964 | ||
1965 | /* | |
ce8e922c NS |
1966 | * Go through all incore buffers, and release buffers if they belong to |
1967 | * the given device. This is used in filesystem error handling to | |
1968 | * preserve the consistency of its metadata. | |
1da177e4 LT |
1969 | */ |
1970 | int | |
1971 | xfs_flush_buftarg( | |
585e6d88 DC |
1972 | xfs_buftarg_t *target, |
1973 | int wait) | |
1da177e4 | 1974 | { |
089716aa | 1975 | xfs_buf_t *bp; |
585e6d88 | 1976 | int pincount = 0; |
089716aa DC |
1977 | LIST_HEAD(tmp_list); |
1978 | LIST_HEAD(wait_list); | |
1da177e4 | 1979 | |
c626d174 | 1980 | xfs_buf_runall_queues(xfsconvertd_workqueue); |
ce8e922c NS |
1981 | xfs_buf_runall_queues(xfsdatad_workqueue); |
1982 | xfs_buf_runall_queues(xfslogd_workqueue); | |
1da177e4 | 1983 | |
5e6a07df | 1984 | set_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
089716aa | 1985 | pincount = xfs_buf_delwri_split(target, &tmp_list, 0); |
1da177e4 LT |
1986 | |
1987 | /* | |
089716aa DC |
1988 | * Dropped the delayed write list lock, now walk the temporary list. |
1989 | * All I/O is issued async and then if we need to wait for completion | |
1990 | * we do that after issuing all the IO. | |
1da177e4 | 1991 | */ |
089716aa DC |
1992 | list_sort(NULL, &tmp_list, xfs_buf_cmp); |
1993 | while (!list_empty(&tmp_list)) { | |
1994 | bp = list_first_entry(&tmp_list, struct xfs_buf, b_list); | |
585e6d88 | 1995 | ASSERT(target == bp->b_target); |
089716aa DC |
1996 | list_del_init(&bp->b_list); |
1997 | if (wait) { | |
ce8e922c | 1998 | bp->b_flags &= ~XBF_ASYNC; |
089716aa DC |
1999 | list_add(&bp->b_list, &wait_list); |
2000 | } | |
939d723b | 2001 | xfs_bdstrat_cb(bp); |
1da177e4 LT |
2002 | } |
2003 | ||
089716aa DC |
2004 | if (wait) { |
2005 | /* Expedite and wait for IO to complete. */ | |
f07c2250 | 2006 | blk_run_address_space(target->bt_mapping); |
089716aa DC |
2007 | while (!list_empty(&wait_list)) { |
2008 | bp = list_first_entry(&wait_list, struct xfs_buf, b_list); | |
f07c2250 | 2009 | |
089716aa | 2010 | list_del_init(&bp->b_list); |
1a1a3e97 | 2011 | xfs_buf_iowait(bp); |
089716aa DC |
2012 | xfs_buf_relse(bp); |
2013 | } | |
1da177e4 LT |
2014 | } |
2015 | ||
1da177e4 LT |
2016 | return pincount; |
2017 | } | |
2018 | ||
04d8b284 | 2019 | int __init |
ce8e922c | 2020 | xfs_buf_init(void) |
1da177e4 | 2021 | { |
8758280f NS |
2022 | xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf", |
2023 | KM_ZONE_HWALIGN, NULL); | |
ce8e922c | 2024 | if (!xfs_buf_zone) |
0b1b213f | 2025 | goto out; |
04d8b284 | 2026 | |
51749e47 | 2027 | xfslogd_workqueue = alloc_workqueue("xfslogd", |
6370a6ad | 2028 | WQ_MEM_RECLAIM | WQ_HIGHPRI, 1); |
23ea4032 | 2029 | if (!xfslogd_workqueue) |
04d8b284 | 2030 | goto out_free_buf_zone; |
1da177e4 | 2031 | |
b4337692 | 2032 | xfsdatad_workqueue = create_workqueue("xfsdatad"); |
23ea4032 CH |
2033 | if (!xfsdatad_workqueue) |
2034 | goto out_destroy_xfslogd_workqueue; | |
1da177e4 | 2035 | |
c626d174 DC |
2036 | xfsconvertd_workqueue = create_workqueue("xfsconvertd"); |
2037 | if (!xfsconvertd_workqueue) | |
2038 | goto out_destroy_xfsdatad_workqueue; | |
2039 | ||
23ea4032 | 2040 | return 0; |
1da177e4 | 2041 | |
c626d174 DC |
2042 | out_destroy_xfsdatad_workqueue: |
2043 | destroy_workqueue(xfsdatad_workqueue); | |
23ea4032 CH |
2044 | out_destroy_xfslogd_workqueue: |
2045 | destroy_workqueue(xfslogd_workqueue); | |
23ea4032 | 2046 | out_free_buf_zone: |
ce8e922c | 2047 | kmem_zone_destroy(xfs_buf_zone); |
0b1b213f | 2048 | out: |
8758280f | 2049 | return -ENOMEM; |
1da177e4 LT |
2050 | } |
2051 | ||
1da177e4 | 2052 | void |
ce8e922c | 2053 | xfs_buf_terminate(void) |
1da177e4 | 2054 | { |
c626d174 | 2055 | destroy_workqueue(xfsconvertd_workqueue); |
04d8b284 CH |
2056 | destroy_workqueue(xfsdatad_workqueue); |
2057 | destroy_workqueue(xfslogd_workqueue); | |
ce8e922c | 2058 | kmem_zone_destroy(xfs_buf_zone); |
1da177e4 | 2059 | } |
e6a0e9cd TS |
2060 | |
2061 | #ifdef CONFIG_KDB_MODULES | |
2062 | struct list_head * | |
2063 | xfs_get_buftarg_list(void) | |
2064 | { | |
2065 | return &xfs_buftarg_list; | |
2066 | } | |
2067 | #endif |