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> |
1da177e4 | 36 | |
b7963133 | 37 | #include "xfs_sb.h" |
ed3b4d6c | 38 | #include "xfs_log.h" |
b7963133 | 39 | #include "xfs_ag.h" |
b7963133 | 40 | #include "xfs_mount.h" |
0b1b213f | 41 | #include "xfs_trace.h" |
b7963133 | 42 | |
7989cb8e | 43 | static kmem_zone_t *xfs_buf_zone; |
23ea4032 | 44 | |
7989cb8e | 45 | static struct workqueue_struct *xfslogd_workqueue; |
1da177e4 | 46 | |
ce8e922c NS |
47 | #ifdef XFS_BUF_LOCK_TRACKING |
48 | # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid) | |
49 | # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1) | |
50 | # define XB_GET_OWNER(bp) ((bp)->b_last_holder) | |
1da177e4 | 51 | #else |
ce8e922c NS |
52 | # define XB_SET_OWNER(bp) do { } while (0) |
53 | # define XB_CLEAR_OWNER(bp) do { } while (0) | |
54 | # define XB_GET_OWNER(bp) do { } while (0) | |
1da177e4 LT |
55 | #endif |
56 | ||
ce8e922c | 57 | #define xb_to_gfp(flags) \ |
aa5c158e | 58 | ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : GFP_NOFS) | __GFP_NOWARN) |
1da177e4 | 59 | |
1da177e4 | 60 | |
73c77e2c JB |
61 | static inline int |
62 | xfs_buf_is_vmapped( | |
63 | struct xfs_buf *bp) | |
64 | { | |
65 | /* | |
66 | * Return true if the buffer is vmapped. | |
67 | * | |
611c9946 DC |
68 | * b_addr is null if the buffer is not mapped, but the code is clever |
69 | * enough to know it doesn't have to map a single page, so the check has | |
70 | * to be both for b_addr and bp->b_page_count > 1. | |
73c77e2c | 71 | */ |
611c9946 | 72 | return bp->b_addr && bp->b_page_count > 1; |
73c77e2c JB |
73 | } |
74 | ||
75 | static inline int | |
76 | xfs_buf_vmap_len( | |
77 | struct xfs_buf *bp) | |
78 | { | |
79 | return (bp->b_page_count * PAGE_SIZE) - bp->b_offset; | |
80 | } | |
81 | ||
1da177e4 | 82 | /* |
430cbeb8 DC |
83 | * xfs_buf_lru_add - add a buffer to the LRU. |
84 | * | |
85 | * The LRU takes a new reference to the buffer so that it will only be freed | |
86 | * once the shrinker takes the buffer off the LRU. | |
87 | */ | |
88 | STATIC void | |
89 | xfs_buf_lru_add( | |
90 | struct xfs_buf *bp) | |
91 | { | |
92 | struct xfs_buftarg *btp = bp->b_target; | |
93 | ||
94 | spin_lock(&btp->bt_lru_lock); | |
95 | if (list_empty(&bp->b_lru)) { | |
96 | atomic_inc(&bp->b_hold); | |
97 | list_add_tail(&bp->b_lru, &btp->bt_lru); | |
98 | btp->bt_lru_nr++; | |
6fb8a90a | 99 | bp->b_lru_flags &= ~_XBF_LRU_DISPOSE; |
430cbeb8 DC |
100 | } |
101 | spin_unlock(&btp->bt_lru_lock); | |
102 | } | |
103 | ||
104 | /* | |
105 | * xfs_buf_lru_del - remove a buffer from the LRU | |
106 | * | |
107 | * The unlocked check is safe here because it only occurs when there are not | |
108 | * b_lru_ref counts left on the inode under the pag->pag_buf_lock. it is there | |
109 | * to optimise the shrinker removing the buffer from the LRU and calling | |
25985edc | 110 | * xfs_buf_free(). i.e. it removes an unnecessary round trip on the |
430cbeb8 | 111 | * bt_lru_lock. |
1da177e4 | 112 | */ |
430cbeb8 DC |
113 | STATIC void |
114 | xfs_buf_lru_del( | |
115 | struct xfs_buf *bp) | |
116 | { | |
117 | struct xfs_buftarg *btp = bp->b_target; | |
118 | ||
119 | if (list_empty(&bp->b_lru)) | |
120 | return; | |
121 | ||
122 | spin_lock(&btp->bt_lru_lock); | |
123 | if (!list_empty(&bp->b_lru)) { | |
124 | list_del_init(&bp->b_lru); | |
125 | btp->bt_lru_nr--; | |
126 | } | |
127 | spin_unlock(&btp->bt_lru_lock); | |
128 | } | |
129 | ||
130 | /* | |
131 | * When we mark a buffer stale, we remove the buffer from the LRU and clear the | |
132 | * b_lru_ref count so that the buffer is freed immediately when the buffer | |
133 | * reference count falls to zero. If the buffer is already on the LRU, we need | |
134 | * to remove the reference that LRU holds on the buffer. | |
135 | * | |
136 | * This prevents build-up of stale buffers on the LRU. | |
137 | */ | |
138 | void | |
139 | xfs_buf_stale( | |
140 | struct xfs_buf *bp) | |
141 | { | |
43ff2122 CH |
142 | ASSERT(xfs_buf_islocked(bp)); |
143 | ||
430cbeb8 | 144 | bp->b_flags |= XBF_STALE; |
43ff2122 CH |
145 | |
146 | /* | |
147 | * Clear the delwri status so that a delwri queue walker will not | |
148 | * flush this buffer to disk now that it is stale. The delwri queue has | |
149 | * a reference to the buffer, so this is safe to do. | |
150 | */ | |
151 | bp->b_flags &= ~_XBF_DELWRI_Q; | |
152 | ||
430cbeb8 DC |
153 | atomic_set(&(bp)->b_lru_ref, 0); |
154 | if (!list_empty(&bp->b_lru)) { | |
155 | struct xfs_buftarg *btp = bp->b_target; | |
156 | ||
157 | spin_lock(&btp->bt_lru_lock); | |
6fb8a90a CM |
158 | if (!list_empty(&bp->b_lru) && |
159 | !(bp->b_lru_flags & _XBF_LRU_DISPOSE)) { | |
430cbeb8 DC |
160 | list_del_init(&bp->b_lru); |
161 | btp->bt_lru_nr--; | |
162 | atomic_dec(&bp->b_hold); | |
163 | } | |
164 | spin_unlock(&btp->bt_lru_lock); | |
165 | } | |
166 | ASSERT(atomic_read(&bp->b_hold) >= 1); | |
167 | } | |
1da177e4 | 168 | |
3e85c868 DC |
169 | static int |
170 | xfs_buf_get_maps( | |
171 | struct xfs_buf *bp, | |
172 | int map_count) | |
173 | { | |
174 | ASSERT(bp->b_maps == NULL); | |
175 | bp->b_map_count = map_count; | |
176 | ||
177 | if (map_count == 1) { | |
f4b42421 | 178 | bp->b_maps = &bp->__b_map; |
3e85c868 DC |
179 | return 0; |
180 | } | |
181 | ||
182 | bp->b_maps = kmem_zalloc(map_count * sizeof(struct xfs_buf_map), | |
183 | KM_NOFS); | |
184 | if (!bp->b_maps) | |
185 | return ENOMEM; | |
186 | return 0; | |
187 | } | |
188 | ||
189 | /* | |
190 | * Frees b_pages if it was allocated. | |
191 | */ | |
192 | static void | |
193 | xfs_buf_free_maps( | |
194 | struct xfs_buf *bp) | |
195 | { | |
f4b42421 | 196 | if (bp->b_maps != &bp->__b_map) { |
3e85c868 DC |
197 | kmem_free(bp->b_maps); |
198 | bp->b_maps = NULL; | |
199 | } | |
200 | } | |
201 | ||
4347b9d7 | 202 | struct xfs_buf * |
3e85c868 | 203 | _xfs_buf_alloc( |
4347b9d7 | 204 | struct xfs_buftarg *target, |
3e85c868 DC |
205 | struct xfs_buf_map *map, |
206 | int nmaps, | |
ce8e922c | 207 | xfs_buf_flags_t flags) |
1da177e4 | 208 | { |
4347b9d7 | 209 | struct xfs_buf *bp; |
3e85c868 DC |
210 | int error; |
211 | int i; | |
4347b9d7 | 212 | |
aa5c158e | 213 | bp = kmem_zone_zalloc(xfs_buf_zone, KM_NOFS); |
4347b9d7 CH |
214 | if (unlikely(!bp)) |
215 | return NULL; | |
216 | ||
1da177e4 | 217 | /* |
12bcb3f7 DC |
218 | * We don't want certain flags to appear in b_flags unless they are |
219 | * specifically set by later operations on the buffer. | |
1da177e4 | 220 | */ |
611c9946 | 221 | flags &= ~(XBF_UNMAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD); |
ce8e922c | 222 | |
ce8e922c | 223 | atomic_set(&bp->b_hold, 1); |
430cbeb8 | 224 | atomic_set(&bp->b_lru_ref, 1); |
b4dd330b | 225 | init_completion(&bp->b_iowait); |
430cbeb8 | 226 | INIT_LIST_HEAD(&bp->b_lru); |
ce8e922c | 227 | INIT_LIST_HEAD(&bp->b_list); |
74f75a0c | 228 | RB_CLEAR_NODE(&bp->b_rbnode); |
a731cd11 | 229 | sema_init(&bp->b_sema, 0); /* held, no waiters */ |
ce8e922c NS |
230 | XB_SET_OWNER(bp); |
231 | bp->b_target = target; | |
3e85c868 | 232 | bp->b_flags = flags; |
de1cbee4 | 233 | |
1da177e4 | 234 | /* |
aa0e8833 DC |
235 | * Set length and io_length to the same value initially. |
236 | * I/O routines should use io_length, which will be the same in | |
1da177e4 LT |
237 | * most cases but may be reset (e.g. XFS recovery). |
238 | */ | |
3e85c868 DC |
239 | error = xfs_buf_get_maps(bp, nmaps); |
240 | if (error) { | |
241 | kmem_zone_free(xfs_buf_zone, bp); | |
242 | return NULL; | |
243 | } | |
244 | ||
245 | bp->b_bn = map[0].bm_bn; | |
246 | bp->b_length = 0; | |
247 | for (i = 0; i < nmaps; i++) { | |
248 | bp->b_maps[i].bm_bn = map[i].bm_bn; | |
249 | bp->b_maps[i].bm_len = map[i].bm_len; | |
250 | bp->b_length += map[i].bm_len; | |
251 | } | |
252 | bp->b_io_length = bp->b_length; | |
253 | ||
ce8e922c NS |
254 | atomic_set(&bp->b_pin_count, 0); |
255 | init_waitqueue_head(&bp->b_waiters); | |
256 | ||
257 | XFS_STATS_INC(xb_create); | |
0b1b213f | 258 | trace_xfs_buf_init(bp, _RET_IP_); |
4347b9d7 CH |
259 | |
260 | return bp; | |
1da177e4 LT |
261 | } |
262 | ||
263 | /* | |
ce8e922c NS |
264 | * Allocate a page array capable of holding a specified number |
265 | * of pages, and point the page buf at it. | |
1da177e4 LT |
266 | */ |
267 | STATIC int | |
ce8e922c NS |
268 | _xfs_buf_get_pages( |
269 | xfs_buf_t *bp, | |
1da177e4 | 270 | int page_count, |
ce8e922c | 271 | xfs_buf_flags_t flags) |
1da177e4 LT |
272 | { |
273 | /* Make sure that we have a page list */ | |
ce8e922c | 274 | if (bp->b_pages == NULL) { |
ce8e922c NS |
275 | bp->b_page_count = page_count; |
276 | if (page_count <= XB_PAGES) { | |
277 | bp->b_pages = bp->b_page_array; | |
1da177e4 | 278 | } else { |
ce8e922c | 279 | bp->b_pages = kmem_alloc(sizeof(struct page *) * |
aa5c158e | 280 | page_count, KM_NOFS); |
ce8e922c | 281 | if (bp->b_pages == NULL) |
1da177e4 LT |
282 | return -ENOMEM; |
283 | } | |
ce8e922c | 284 | memset(bp->b_pages, 0, sizeof(struct page *) * page_count); |
1da177e4 LT |
285 | } |
286 | return 0; | |
287 | } | |
288 | ||
289 | /* | |
ce8e922c | 290 | * Frees b_pages if it was allocated. |
1da177e4 LT |
291 | */ |
292 | STATIC void | |
ce8e922c | 293 | _xfs_buf_free_pages( |
1da177e4 LT |
294 | xfs_buf_t *bp) |
295 | { | |
ce8e922c | 296 | if (bp->b_pages != bp->b_page_array) { |
f0e2d93c | 297 | kmem_free(bp->b_pages); |
3fc98b1a | 298 | bp->b_pages = NULL; |
1da177e4 LT |
299 | } |
300 | } | |
301 | ||
302 | /* | |
303 | * Releases the specified buffer. | |
304 | * | |
305 | * The modification state of any associated pages is left unchanged. | |
ce8e922c | 306 | * The buffer most not be on any hash - use xfs_buf_rele instead for |
1da177e4 LT |
307 | * hashed and refcounted buffers |
308 | */ | |
309 | void | |
ce8e922c | 310 | xfs_buf_free( |
1da177e4 LT |
311 | xfs_buf_t *bp) |
312 | { | |
0b1b213f | 313 | trace_xfs_buf_free(bp, _RET_IP_); |
1da177e4 | 314 | |
430cbeb8 DC |
315 | ASSERT(list_empty(&bp->b_lru)); |
316 | ||
0e6e847f | 317 | if (bp->b_flags & _XBF_PAGES) { |
1da177e4 LT |
318 | uint i; |
319 | ||
73c77e2c | 320 | if (xfs_buf_is_vmapped(bp)) |
8a262e57 AE |
321 | vm_unmap_ram(bp->b_addr - bp->b_offset, |
322 | bp->b_page_count); | |
1da177e4 | 323 | |
948ecdb4 NS |
324 | for (i = 0; i < bp->b_page_count; i++) { |
325 | struct page *page = bp->b_pages[i]; | |
326 | ||
0e6e847f | 327 | __free_page(page); |
948ecdb4 | 328 | } |
0e6e847f DC |
329 | } else if (bp->b_flags & _XBF_KMEM) |
330 | kmem_free(bp->b_addr); | |
3fc98b1a | 331 | _xfs_buf_free_pages(bp); |
3e85c868 | 332 | xfs_buf_free_maps(bp); |
4347b9d7 | 333 | kmem_zone_free(xfs_buf_zone, bp); |
1da177e4 LT |
334 | } |
335 | ||
336 | /* | |
0e6e847f | 337 | * Allocates all the pages for buffer in question and builds it's page list. |
1da177e4 LT |
338 | */ |
339 | STATIC int | |
0e6e847f | 340 | xfs_buf_allocate_memory( |
1da177e4 LT |
341 | xfs_buf_t *bp, |
342 | uint flags) | |
343 | { | |
aa0e8833 | 344 | size_t size; |
1da177e4 | 345 | size_t nbytes, offset; |
ce8e922c | 346 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 | 347 | unsigned short page_count, i; |
795cac72 | 348 | xfs_off_t start, end; |
1da177e4 LT |
349 | int error; |
350 | ||
0e6e847f DC |
351 | /* |
352 | * for buffers that are contained within a single page, just allocate | |
353 | * the memory from the heap - there's no need for the complexity of | |
354 | * page arrays to keep allocation down to order 0. | |
355 | */ | |
795cac72 DC |
356 | size = BBTOB(bp->b_length); |
357 | if (size < PAGE_SIZE) { | |
aa5c158e | 358 | bp->b_addr = kmem_alloc(size, KM_NOFS); |
0e6e847f DC |
359 | if (!bp->b_addr) { |
360 | /* low memory - use alloc_page loop instead */ | |
361 | goto use_alloc_page; | |
362 | } | |
363 | ||
795cac72 | 364 | if (((unsigned long)(bp->b_addr + size - 1) & PAGE_MASK) != |
0e6e847f DC |
365 | ((unsigned long)bp->b_addr & PAGE_MASK)) { |
366 | /* b_addr spans two pages - use alloc_page instead */ | |
367 | kmem_free(bp->b_addr); | |
368 | bp->b_addr = NULL; | |
369 | goto use_alloc_page; | |
370 | } | |
371 | bp->b_offset = offset_in_page(bp->b_addr); | |
372 | bp->b_pages = bp->b_page_array; | |
373 | bp->b_pages[0] = virt_to_page(bp->b_addr); | |
374 | bp->b_page_count = 1; | |
611c9946 | 375 | bp->b_flags |= _XBF_KMEM; |
0e6e847f DC |
376 | return 0; |
377 | } | |
378 | ||
379 | use_alloc_page: | |
f4b42421 MT |
380 | start = BBTOB(bp->b_maps[0].bm_bn) >> PAGE_SHIFT; |
381 | end = (BBTOB(bp->b_maps[0].bm_bn + bp->b_length) + PAGE_SIZE - 1) | |
cbb7baab | 382 | >> PAGE_SHIFT; |
795cac72 | 383 | page_count = end - start; |
ce8e922c | 384 | error = _xfs_buf_get_pages(bp, page_count, flags); |
1da177e4 LT |
385 | if (unlikely(error)) |
386 | return error; | |
1da177e4 | 387 | |
ce8e922c | 388 | offset = bp->b_offset; |
0e6e847f | 389 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 390 | |
ce8e922c | 391 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
392 | struct page *page; |
393 | uint retries = 0; | |
0e6e847f DC |
394 | retry: |
395 | page = alloc_page(gfp_mask); | |
1da177e4 | 396 | if (unlikely(page == NULL)) { |
ce8e922c NS |
397 | if (flags & XBF_READ_AHEAD) { |
398 | bp->b_page_count = i; | |
0e6e847f DC |
399 | error = ENOMEM; |
400 | goto out_free_pages; | |
1da177e4 LT |
401 | } |
402 | ||
403 | /* | |
404 | * This could deadlock. | |
405 | * | |
406 | * But until all the XFS lowlevel code is revamped to | |
407 | * handle buffer allocation failures we can't do much. | |
408 | */ | |
409 | if (!(++retries % 100)) | |
4f10700a DC |
410 | xfs_err(NULL, |
411 | "possible memory allocation deadlock in %s (mode:0x%x)", | |
34a622b2 | 412 | __func__, gfp_mask); |
1da177e4 | 413 | |
ce8e922c | 414 | XFS_STATS_INC(xb_page_retries); |
8aa7e847 | 415 | congestion_wait(BLK_RW_ASYNC, HZ/50); |
1da177e4 LT |
416 | goto retry; |
417 | } | |
418 | ||
ce8e922c | 419 | XFS_STATS_INC(xb_page_found); |
1da177e4 | 420 | |
0e6e847f | 421 | nbytes = min_t(size_t, size, PAGE_SIZE - offset); |
1da177e4 | 422 | size -= nbytes; |
ce8e922c | 423 | bp->b_pages[i] = page; |
1da177e4 LT |
424 | offset = 0; |
425 | } | |
0e6e847f | 426 | return 0; |
1da177e4 | 427 | |
0e6e847f DC |
428 | out_free_pages: |
429 | for (i = 0; i < bp->b_page_count; i++) | |
430 | __free_page(bp->b_pages[i]); | |
1da177e4 LT |
431 | return error; |
432 | } | |
433 | ||
434 | /* | |
25985edc | 435 | * Map buffer into kernel address-space if necessary. |
1da177e4 LT |
436 | */ |
437 | STATIC int | |
ce8e922c | 438 | _xfs_buf_map_pages( |
1da177e4 LT |
439 | xfs_buf_t *bp, |
440 | uint flags) | |
441 | { | |
0e6e847f | 442 | ASSERT(bp->b_flags & _XBF_PAGES); |
ce8e922c | 443 | if (bp->b_page_count == 1) { |
0e6e847f | 444 | /* A single page buffer is always mappable */ |
ce8e922c | 445 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; |
611c9946 DC |
446 | } else if (flags & XBF_UNMAPPED) { |
447 | bp->b_addr = NULL; | |
448 | } else { | |
a19fb380 DC |
449 | int retried = 0; |
450 | ||
451 | do { | |
452 | bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, | |
453 | -1, PAGE_KERNEL); | |
454 | if (bp->b_addr) | |
455 | break; | |
456 | vm_unmap_aliases(); | |
457 | } while (retried++ <= 1); | |
458 | ||
459 | if (!bp->b_addr) | |
1da177e4 | 460 | return -ENOMEM; |
ce8e922c | 461 | bp->b_addr += bp->b_offset; |
1da177e4 LT |
462 | } |
463 | ||
464 | return 0; | |
465 | } | |
466 | ||
467 | /* | |
468 | * Finding and Reading Buffers | |
469 | */ | |
470 | ||
471 | /* | |
ce8e922c | 472 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 | 473 | * a given range of an inode. The buffer is returned |
eabbaf11 | 474 | * locked. No I/O is implied by this call. |
1da177e4 LT |
475 | */ |
476 | xfs_buf_t * | |
ce8e922c | 477 | _xfs_buf_find( |
e70b73f8 | 478 | struct xfs_buftarg *btp, |
3e85c868 DC |
479 | struct xfs_buf_map *map, |
480 | int nmaps, | |
ce8e922c NS |
481 | xfs_buf_flags_t flags, |
482 | xfs_buf_t *new_bp) | |
1da177e4 | 483 | { |
e70b73f8 | 484 | size_t numbytes; |
74f75a0c DC |
485 | struct xfs_perag *pag; |
486 | struct rb_node **rbp; | |
487 | struct rb_node *parent; | |
488 | xfs_buf_t *bp; | |
3e85c868 | 489 | xfs_daddr_t blkno = map[0].bm_bn; |
10616b80 | 490 | xfs_daddr_t eofs; |
3e85c868 DC |
491 | int numblks = 0; |
492 | int i; | |
1da177e4 | 493 | |
3e85c868 DC |
494 | for (i = 0; i < nmaps; i++) |
495 | numblks += map[i].bm_len; | |
e70b73f8 | 496 | numbytes = BBTOB(numblks); |
1da177e4 LT |
497 | |
498 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
e70b73f8 | 499 | ASSERT(!(numbytes < (1 << btp->bt_sshift))); |
de1cbee4 | 500 | ASSERT(!(BBTOB(blkno) & (xfs_off_t)btp->bt_smask)); |
1da177e4 | 501 | |
10616b80 DC |
502 | /* |
503 | * Corrupted block numbers can get through to here, unfortunately, so we | |
504 | * have to check that the buffer falls within the filesystem bounds. | |
505 | */ | |
506 | eofs = XFS_FSB_TO_BB(btp->bt_mount, btp->bt_mount->m_sb.sb_dblocks); | |
507 | if (blkno >= eofs) { | |
508 | /* | |
509 | * XXX (dgc): we should really be returning EFSCORRUPTED here, | |
510 | * but none of the higher level infrastructure supports | |
511 | * returning a specific error on buffer lookup failures. | |
512 | */ | |
513 | xfs_alert(btp->bt_mount, | |
514 | "%s: Block out of range: block 0x%llx, EOFS 0x%llx ", | |
515 | __func__, blkno, eofs); | |
7bc0dc27 | 516 | WARN_ON(1); |
10616b80 DC |
517 | return NULL; |
518 | } | |
519 | ||
74f75a0c DC |
520 | /* get tree root */ |
521 | pag = xfs_perag_get(btp->bt_mount, | |
e70b73f8 | 522 | xfs_daddr_to_agno(btp->bt_mount, blkno)); |
74f75a0c DC |
523 | |
524 | /* walk tree */ | |
525 | spin_lock(&pag->pag_buf_lock); | |
526 | rbp = &pag->pag_buf_tree.rb_node; | |
527 | parent = NULL; | |
528 | bp = NULL; | |
529 | while (*rbp) { | |
530 | parent = *rbp; | |
531 | bp = rb_entry(parent, struct xfs_buf, b_rbnode); | |
532 | ||
de1cbee4 | 533 | if (blkno < bp->b_bn) |
74f75a0c | 534 | rbp = &(*rbp)->rb_left; |
de1cbee4 | 535 | else if (blkno > bp->b_bn) |
74f75a0c DC |
536 | rbp = &(*rbp)->rb_right; |
537 | else { | |
538 | /* | |
de1cbee4 | 539 | * found a block number match. If the range doesn't |
74f75a0c DC |
540 | * match, the only way this is allowed is if the buffer |
541 | * in the cache is stale and the transaction that made | |
542 | * it stale has not yet committed. i.e. we are | |
543 | * reallocating a busy extent. Skip this buffer and | |
544 | * continue searching to the right for an exact match. | |
545 | */ | |
4e94b71b | 546 | if (bp->b_length != numblks) { |
74f75a0c DC |
547 | ASSERT(bp->b_flags & XBF_STALE); |
548 | rbp = &(*rbp)->rb_right; | |
549 | continue; | |
550 | } | |
ce8e922c | 551 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
552 | goto found; |
553 | } | |
554 | } | |
555 | ||
556 | /* No match found */ | |
ce8e922c | 557 | if (new_bp) { |
74f75a0c DC |
558 | rb_link_node(&new_bp->b_rbnode, parent, rbp); |
559 | rb_insert_color(&new_bp->b_rbnode, &pag->pag_buf_tree); | |
560 | /* the buffer keeps the perag reference until it is freed */ | |
561 | new_bp->b_pag = pag; | |
562 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 563 | } else { |
ce8e922c | 564 | XFS_STATS_INC(xb_miss_locked); |
74f75a0c DC |
565 | spin_unlock(&pag->pag_buf_lock); |
566 | xfs_perag_put(pag); | |
1da177e4 | 567 | } |
ce8e922c | 568 | return new_bp; |
1da177e4 LT |
569 | |
570 | found: | |
74f75a0c DC |
571 | spin_unlock(&pag->pag_buf_lock); |
572 | xfs_perag_put(pag); | |
1da177e4 | 573 | |
0c842ad4 CH |
574 | if (!xfs_buf_trylock(bp)) { |
575 | if (flags & XBF_TRYLOCK) { | |
ce8e922c NS |
576 | xfs_buf_rele(bp); |
577 | XFS_STATS_INC(xb_busy_locked); | |
578 | return NULL; | |
1da177e4 | 579 | } |
0c842ad4 CH |
580 | xfs_buf_lock(bp); |
581 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 LT |
582 | } |
583 | ||
0e6e847f DC |
584 | /* |
585 | * if the buffer is stale, clear all the external state associated with | |
586 | * it. We need to keep flags such as how we allocated the buffer memory | |
587 | * intact here. | |
588 | */ | |
ce8e922c NS |
589 | if (bp->b_flags & XBF_STALE) { |
590 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
cfb02852 | 591 | ASSERT(bp->b_iodone == NULL); |
611c9946 | 592 | bp->b_flags &= _XBF_KMEM | _XBF_PAGES; |
1813dd64 | 593 | bp->b_ops = NULL; |
2f926587 | 594 | } |
0b1b213f CH |
595 | |
596 | trace_xfs_buf_find(bp, flags, _RET_IP_); | |
ce8e922c NS |
597 | XFS_STATS_INC(xb_get_locked); |
598 | return bp; | |
1da177e4 LT |
599 | } |
600 | ||
601 | /* | |
3815832a DC |
602 | * Assembles a buffer covering the specified range. The code is optimised for |
603 | * cache hits, as metadata intensive workloads will see 3 orders of magnitude | |
604 | * more hits than misses. | |
1da177e4 | 605 | */ |
3815832a | 606 | struct xfs_buf * |
6dde2707 DC |
607 | xfs_buf_get_map( |
608 | struct xfs_buftarg *target, | |
609 | struct xfs_buf_map *map, | |
610 | int nmaps, | |
ce8e922c | 611 | xfs_buf_flags_t flags) |
1da177e4 | 612 | { |
3815832a DC |
613 | struct xfs_buf *bp; |
614 | struct xfs_buf *new_bp; | |
0e6e847f | 615 | int error = 0; |
1da177e4 | 616 | |
6dde2707 | 617 | bp = _xfs_buf_find(target, map, nmaps, flags, NULL); |
3815832a DC |
618 | if (likely(bp)) |
619 | goto found; | |
620 | ||
6dde2707 | 621 | new_bp = _xfs_buf_alloc(target, map, nmaps, flags); |
ce8e922c | 622 | if (unlikely(!new_bp)) |
1da177e4 LT |
623 | return NULL; |
624 | ||
fe2429b0 DC |
625 | error = xfs_buf_allocate_memory(new_bp, flags); |
626 | if (error) { | |
3e85c868 | 627 | xfs_buf_free(new_bp); |
fe2429b0 DC |
628 | return NULL; |
629 | } | |
630 | ||
6dde2707 | 631 | bp = _xfs_buf_find(target, map, nmaps, flags, new_bp); |
3815832a | 632 | if (!bp) { |
fe2429b0 | 633 | xfs_buf_free(new_bp); |
3815832a DC |
634 | return NULL; |
635 | } | |
636 | ||
fe2429b0 DC |
637 | if (bp != new_bp) |
638 | xfs_buf_free(new_bp); | |
1da177e4 | 639 | |
3815832a | 640 | found: |
611c9946 | 641 | if (!bp->b_addr) { |
ce8e922c | 642 | error = _xfs_buf_map_pages(bp, flags); |
1da177e4 | 643 | if (unlikely(error)) { |
4f10700a DC |
644 | xfs_warn(target->bt_mount, |
645 | "%s: failed to map pages\n", __func__); | |
a8acad70 DC |
646 | xfs_buf_relse(bp); |
647 | return NULL; | |
1da177e4 LT |
648 | } |
649 | } | |
650 | ||
ce8e922c | 651 | XFS_STATS_INC(xb_get); |
0b1b213f | 652 | trace_xfs_buf_get(bp, flags, _RET_IP_); |
ce8e922c | 653 | return bp; |
1da177e4 LT |
654 | } |
655 | ||
5d765b97 CH |
656 | STATIC int |
657 | _xfs_buf_read( | |
658 | xfs_buf_t *bp, | |
659 | xfs_buf_flags_t flags) | |
660 | { | |
43ff2122 | 661 | ASSERT(!(flags & XBF_WRITE)); |
f4b42421 | 662 | ASSERT(bp->b_maps[0].bm_bn != XFS_BUF_DADDR_NULL); |
5d765b97 | 663 | |
43ff2122 | 664 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD); |
1d5ae5df | 665 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD); |
5d765b97 | 666 | |
0e95f19a DC |
667 | xfs_buf_iorequest(bp); |
668 | if (flags & XBF_ASYNC) | |
669 | return 0; | |
ec53d1db | 670 | return xfs_buf_iowait(bp); |
5d765b97 CH |
671 | } |
672 | ||
1da177e4 | 673 | xfs_buf_t * |
6dde2707 DC |
674 | xfs_buf_read_map( |
675 | struct xfs_buftarg *target, | |
676 | struct xfs_buf_map *map, | |
677 | int nmaps, | |
c3f8fc73 | 678 | xfs_buf_flags_t flags, |
1813dd64 | 679 | const struct xfs_buf_ops *ops) |
1da177e4 | 680 | { |
6dde2707 | 681 | struct xfs_buf *bp; |
ce8e922c NS |
682 | |
683 | flags |= XBF_READ; | |
684 | ||
6dde2707 | 685 | bp = xfs_buf_get_map(target, map, nmaps, flags); |
ce8e922c | 686 | if (bp) { |
0b1b213f CH |
687 | trace_xfs_buf_read(bp, flags, _RET_IP_); |
688 | ||
ce8e922c | 689 | if (!XFS_BUF_ISDONE(bp)) { |
ce8e922c | 690 | XFS_STATS_INC(xb_get_read); |
1813dd64 | 691 | bp->b_ops = ops; |
5d765b97 | 692 | _xfs_buf_read(bp, flags); |
ce8e922c | 693 | } else if (flags & XBF_ASYNC) { |
1da177e4 LT |
694 | /* |
695 | * Read ahead call which is already satisfied, | |
696 | * drop the buffer | |
697 | */ | |
a8acad70 DC |
698 | xfs_buf_relse(bp); |
699 | return NULL; | |
1da177e4 | 700 | } else { |
1da177e4 | 701 | /* We do not want read in the flags */ |
ce8e922c | 702 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
703 | } |
704 | } | |
705 | ||
ce8e922c | 706 | return bp; |
1da177e4 LT |
707 | } |
708 | ||
1da177e4 | 709 | /* |
ce8e922c NS |
710 | * If we are not low on memory then do the readahead in a deadlock |
711 | * safe manner. | |
1da177e4 LT |
712 | */ |
713 | void | |
6dde2707 DC |
714 | xfs_buf_readahead_map( |
715 | struct xfs_buftarg *target, | |
716 | struct xfs_buf_map *map, | |
c3f8fc73 | 717 | int nmaps, |
1813dd64 | 718 | const struct xfs_buf_ops *ops) |
1da177e4 | 719 | { |
0e6e847f | 720 | if (bdi_read_congested(target->bt_bdi)) |
1da177e4 LT |
721 | return; |
722 | ||
6dde2707 | 723 | xfs_buf_read_map(target, map, nmaps, |
1813dd64 | 724 | XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD, ops); |
1da177e4 LT |
725 | } |
726 | ||
5adc94c2 DC |
727 | /* |
728 | * Read an uncached buffer from disk. Allocates and returns a locked | |
729 | * buffer containing the disk contents or nothing. | |
730 | */ | |
731 | struct xfs_buf * | |
732 | xfs_buf_read_uncached( | |
5adc94c2 DC |
733 | struct xfs_buftarg *target, |
734 | xfs_daddr_t daddr, | |
e70b73f8 | 735 | size_t numblks, |
c3f8fc73 | 736 | int flags, |
1813dd64 | 737 | const struct xfs_buf_ops *ops) |
5adc94c2 | 738 | { |
eab4e633 | 739 | struct xfs_buf *bp; |
5adc94c2 | 740 | |
e70b73f8 | 741 | bp = xfs_buf_get_uncached(target, numblks, flags); |
5adc94c2 DC |
742 | if (!bp) |
743 | return NULL; | |
744 | ||
745 | /* set up the buffer for a read IO */ | |
3e85c868 DC |
746 | ASSERT(bp->b_map_count == 1); |
747 | bp->b_bn = daddr; | |
748 | bp->b_maps[0].bm_bn = daddr; | |
cbb7baab | 749 | bp->b_flags |= XBF_READ; |
1813dd64 | 750 | bp->b_ops = ops; |
5adc94c2 | 751 | |
e70b73f8 | 752 | xfsbdstrat(target->bt_mount, bp); |
eab4e633 | 753 | xfs_buf_iowait(bp); |
5adc94c2 | 754 | return bp; |
1da177e4 LT |
755 | } |
756 | ||
44396476 DC |
757 | /* |
758 | * Return a buffer allocated as an empty buffer and associated to external | |
759 | * memory via xfs_buf_associate_memory() back to it's empty state. | |
760 | */ | |
761 | void | |
762 | xfs_buf_set_empty( | |
763 | struct xfs_buf *bp, | |
e70b73f8 | 764 | size_t numblks) |
44396476 DC |
765 | { |
766 | if (bp->b_pages) | |
767 | _xfs_buf_free_pages(bp); | |
768 | ||
769 | bp->b_pages = NULL; | |
770 | bp->b_page_count = 0; | |
771 | bp->b_addr = NULL; | |
4e94b71b | 772 | bp->b_length = numblks; |
aa0e8833 | 773 | bp->b_io_length = numblks; |
3e85c868 DC |
774 | |
775 | ASSERT(bp->b_map_count == 1); | |
44396476 | 776 | bp->b_bn = XFS_BUF_DADDR_NULL; |
3e85c868 DC |
777 | bp->b_maps[0].bm_bn = XFS_BUF_DADDR_NULL; |
778 | bp->b_maps[0].bm_len = bp->b_length; | |
44396476 DC |
779 | } |
780 | ||
1da177e4 LT |
781 | static inline struct page * |
782 | mem_to_page( | |
783 | void *addr) | |
784 | { | |
9e2779fa | 785 | if ((!is_vmalloc_addr(addr))) { |
1da177e4 LT |
786 | return virt_to_page(addr); |
787 | } else { | |
788 | return vmalloc_to_page(addr); | |
789 | } | |
790 | } | |
791 | ||
792 | int | |
ce8e922c NS |
793 | xfs_buf_associate_memory( |
794 | xfs_buf_t *bp, | |
1da177e4 LT |
795 | void *mem, |
796 | size_t len) | |
797 | { | |
798 | int rval; | |
799 | int i = 0; | |
d1afb678 LM |
800 | unsigned long pageaddr; |
801 | unsigned long offset; | |
802 | size_t buflen; | |
1da177e4 LT |
803 | int page_count; |
804 | ||
0e6e847f | 805 | pageaddr = (unsigned long)mem & PAGE_MASK; |
d1afb678 | 806 | offset = (unsigned long)mem - pageaddr; |
0e6e847f DC |
807 | buflen = PAGE_ALIGN(len + offset); |
808 | page_count = buflen >> PAGE_SHIFT; | |
1da177e4 LT |
809 | |
810 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
811 | if (bp->b_pages) |
812 | _xfs_buf_free_pages(bp); | |
1da177e4 | 813 | |
ce8e922c NS |
814 | bp->b_pages = NULL; |
815 | bp->b_addr = mem; | |
1da177e4 | 816 | |
aa5c158e | 817 | rval = _xfs_buf_get_pages(bp, page_count, 0); |
1da177e4 LT |
818 | if (rval) |
819 | return rval; | |
820 | ||
ce8e922c | 821 | bp->b_offset = offset; |
d1afb678 LM |
822 | |
823 | for (i = 0; i < bp->b_page_count; i++) { | |
824 | bp->b_pages[i] = mem_to_page((void *)pageaddr); | |
0e6e847f | 825 | pageaddr += PAGE_SIZE; |
1da177e4 | 826 | } |
1da177e4 | 827 | |
aa0e8833 | 828 | bp->b_io_length = BTOBB(len); |
4e94b71b | 829 | bp->b_length = BTOBB(buflen); |
1da177e4 LT |
830 | |
831 | return 0; | |
832 | } | |
833 | ||
834 | xfs_buf_t * | |
686865f7 DC |
835 | xfs_buf_get_uncached( |
836 | struct xfs_buftarg *target, | |
e70b73f8 | 837 | size_t numblks, |
686865f7 | 838 | int flags) |
1da177e4 | 839 | { |
e70b73f8 | 840 | unsigned long page_count; |
1fa40b01 | 841 | int error, i; |
3e85c868 DC |
842 | struct xfs_buf *bp; |
843 | DEFINE_SINGLE_BUF_MAP(map, XFS_BUF_DADDR_NULL, numblks); | |
1da177e4 | 844 | |
3e85c868 | 845 | bp = _xfs_buf_alloc(target, &map, 1, 0); |
1da177e4 LT |
846 | if (unlikely(bp == NULL)) |
847 | goto fail; | |
1da177e4 | 848 | |
e70b73f8 | 849 | page_count = PAGE_ALIGN(numblks << BBSHIFT) >> PAGE_SHIFT; |
1fa40b01 CH |
850 | error = _xfs_buf_get_pages(bp, page_count, 0); |
851 | if (error) | |
1da177e4 LT |
852 | goto fail_free_buf; |
853 | ||
1fa40b01 | 854 | for (i = 0; i < page_count; i++) { |
686865f7 | 855 | bp->b_pages[i] = alloc_page(xb_to_gfp(flags)); |
1fa40b01 CH |
856 | if (!bp->b_pages[i]) |
857 | goto fail_free_mem; | |
1da177e4 | 858 | } |
1fa40b01 | 859 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 860 | |
611c9946 | 861 | error = _xfs_buf_map_pages(bp, 0); |
1fa40b01 | 862 | if (unlikely(error)) { |
4f10700a DC |
863 | xfs_warn(target->bt_mount, |
864 | "%s: failed to map pages\n", __func__); | |
1da177e4 | 865 | goto fail_free_mem; |
1fa40b01 | 866 | } |
1da177e4 | 867 | |
686865f7 | 868 | trace_xfs_buf_get_uncached(bp, _RET_IP_); |
1da177e4 | 869 | return bp; |
1fa40b01 | 870 | |
1da177e4 | 871 | fail_free_mem: |
1fa40b01 CH |
872 | while (--i >= 0) |
873 | __free_page(bp->b_pages[i]); | |
ca165b88 | 874 | _xfs_buf_free_pages(bp); |
1da177e4 | 875 | fail_free_buf: |
3e85c868 | 876 | xfs_buf_free_maps(bp); |
4347b9d7 | 877 | kmem_zone_free(xfs_buf_zone, bp); |
1da177e4 LT |
878 | fail: |
879 | return NULL; | |
880 | } | |
881 | ||
882 | /* | |
1da177e4 LT |
883 | * Increment reference count on buffer, to hold the buffer concurrently |
884 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
885 | * Must hold the buffer already to call this function. |
886 | */ | |
887 | void | |
ce8e922c NS |
888 | xfs_buf_hold( |
889 | xfs_buf_t *bp) | |
1da177e4 | 890 | { |
0b1b213f | 891 | trace_xfs_buf_hold(bp, _RET_IP_); |
ce8e922c | 892 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
893 | } |
894 | ||
895 | /* | |
ce8e922c NS |
896 | * Releases a hold on the specified buffer. If the |
897 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
898 | */ |
899 | void | |
ce8e922c NS |
900 | xfs_buf_rele( |
901 | xfs_buf_t *bp) | |
1da177e4 | 902 | { |
74f75a0c | 903 | struct xfs_perag *pag = bp->b_pag; |
1da177e4 | 904 | |
0b1b213f | 905 | trace_xfs_buf_rele(bp, _RET_IP_); |
1da177e4 | 906 | |
74f75a0c | 907 | if (!pag) { |
430cbeb8 | 908 | ASSERT(list_empty(&bp->b_lru)); |
74f75a0c | 909 | ASSERT(RB_EMPTY_NODE(&bp->b_rbnode)); |
fad3aa1e NS |
910 | if (atomic_dec_and_test(&bp->b_hold)) |
911 | xfs_buf_free(bp); | |
912 | return; | |
913 | } | |
914 | ||
74f75a0c | 915 | ASSERT(!RB_EMPTY_NODE(&bp->b_rbnode)); |
430cbeb8 | 916 | |
3790689f | 917 | ASSERT(atomic_read(&bp->b_hold) > 0); |
74f75a0c | 918 | if (atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock)) { |
bfc60177 | 919 | if (!(bp->b_flags & XBF_STALE) && |
430cbeb8 DC |
920 | atomic_read(&bp->b_lru_ref)) { |
921 | xfs_buf_lru_add(bp); | |
922 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 923 | } else { |
430cbeb8 | 924 | xfs_buf_lru_del(bp); |
43ff2122 | 925 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); |
74f75a0c DC |
926 | rb_erase(&bp->b_rbnode, &pag->pag_buf_tree); |
927 | spin_unlock(&pag->pag_buf_lock); | |
928 | xfs_perag_put(pag); | |
ce8e922c | 929 | xfs_buf_free(bp); |
1da177e4 LT |
930 | } |
931 | } | |
932 | } | |
933 | ||
934 | ||
935 | /* | |
0e6e847f | 936 | * Lock a buffer object, if it is not already locked. |
90810b9e DC |
937 | * |
938 | * If we come across a stale, pinned, locked buffer, we know that we are | |
939 | * being asked to lock a buffer that has been reallocated. Because it is | |
940 | * pinned, we know that the log has not been pushed to disk and hence it | |
941 | * will still be locked. Rather than continuing to have trylock attempts | |
942 | * fail until someone else pushes the log, push it ourselves before | |
943 | * returning. This means that the xfsaild will not get stuck trying | |
944 | * to push on stale inode buffers. | |
1da177e4 LT |
945 | */ |
946 | int | |
0c842ad4 CH |
947 | xfs_buf_trylock( |
948 | struct xfs_buf *bp) | |
1da177e4 LT |
949 | { |
950 | int locked; | |
951 | ||
ce8e922c | 952 | locked = down_trylock(&bp->b_sema) == 0; |
0b1b213f | 953 | if (locked) |
ce8e922c | 954 | XB_SET_OWNER(bp); |
0b1b213f | 955 | |
0c842ad4 CH |
956 | trace_xfs_buf_trylock(bp, _RET_IP_); |
957 | return locked; | |
1da177e4 | 958 | } |
1da177e4 LT |
959 | |
960 | /* | |
0e6e847f | 961 | * Lock a buffer object. |
ed3b4d6c DC |
962 | * |
963 | * If we come across a stale, pinned, locked buffer, we know that we | |
964 | * are being asked to lock a buffer that has been reallocated. Because | |
965 | * it is pinned, we know that the log has not been pushed to disk and | |
966 | * hence it will still be locked. Rather than sleeping until someone | |
967 | * else pushes the log, push it ourselves before trying to get the lock. | |
1da177e4 | 968 | */ |
ce8e922c NS |
969 | void |
970 | xfs_buf_lock( | |
0c842ad4 | 971 | struct xfs_buf *bp) |
1da177e4 | 972 | { |
0b1b213f CH |
973 | trace_xfs_buf_lock(bp, _RET_IP_); |
974 | ||
ed3b4d6c | 975 | if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
ebad861b | 976 | xfs_log_force(bp->b_target->bt_mount, 0); |
ce8e922c NS |
977 | down(&bp->b_sema); |
978 | XB_SET_OWNER(bp); | |
0b1b213f CH |
979 | |
980 | trace_xfs_buf_lock_done(bp, _RET_IP_); | |
1da177e4 LT |
981 | } |
982 | ||
1da177e4 | 983 | void |
ce8e922c | 984 | xfs_buf_unlock( |
0c842ad4 | 985 | struct xfs_buf *bp) |
1da177e4 | 986 | { |
ce8e922c NS |
987 | XB_CLEAR_OWNER(bp); |
988 | up(&bp->b_sema); | |
0b1b213f CH |
989 | |
990 | trace_xfs_buf_unlock(bp, _RET_IP_); | |
1da177e4 LT |
991 | } |
992 | ||
ce8e922c NS |
993 | STATIC void |
994 | xfs_buf_wait_unpin( | |
995 | xfs_buf_t *bp) | |
1da177e4 LT |
996 | { |
997 | DECLARE_WAITQUEUE (wait, current); | |
998 | ||
ce8e922c | 999 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
1000 | return; |
1001 | ||
ce8e922c | 1002 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1003 | for (;;) { |
1004 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 1005 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 1006 | break; |
7eaceacc | 1007 | io_schedule(); |
1da177e4 | 1008 | } |
ce8e922c | 1009 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1010 | set_current_state(TASK_RUNNING); |
1011 | } | |
1012 | ||
1013 | /* | |
1014 | * Buffer Utility Routines | |
1015 | */ | |
1016 | ||
1da177e4 | 1017 | STATIC void |
ce8e922c | 1018 | xfs_buf_iodone_work( |
c4028958 | 1019 | struct work_struct *work) |
1da177e4 | 1020 | { |
1813dd64 | 1021 | struct xfs_buf *bp = |
c4028958 | 1022 | container_of(work, xfs_buf_t, b_iodone_work); |
1813dd64 DC |
1023 | bool read = !!(bp->b_flags & XBF_READ); |
1024 | ||
1025 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); | |
d5929de8 DC |
1026 | |
1027 | /* only validate buffers that were read without errors */ | |
1028 | if (read && bp->b_ops && !bp->b_error && (bp->b_flags & XBF_DONE)) | |
1813dd64 | 1029 | bp->b_ops->verify_read(bp); |
1da177e4 | 1030 | |
80f6c29d | 1031 | if (bp->b_iodone) |
ce8e922c NS |
1032 | (*(bp->b_iodone))(bp); |
1033 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 | 1034 | xfs_buf_relse(bp); |
1813dd64 DC |
1035 | else { |
1036 | ASSERT(read && bp->b_ops); | |
1037 | complete(&bp->b_iowait); | |
1038 | } | |
1da177e4 LT |
1039 | } |
1040 | ||
1041 | void | |
ce8e922c | 1042 | xfs_buf_ioend( |
1813dd64 DC |
1043 | struct xfs_buf *bp, |
1044 | int schedule) | |
1da177e4 | 1045 | { |
1813dd64 DC |
1046 | bool read = !!(bp->b_flags & XBF_READ); |
1047 | ||
0b1b213f CH |
1048 | trace_xfs_buf_iodone(bp, _RET_IP_); |
1049 | ||
ce8e922c NS |
1050 | if (bp->b_error == 0) |
1051 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1052 | |
1813dd64 | 1053 | if (bp->b_iodone || (read && bp->b_ops) || (bp->b_flags & XBF_ASYNC)) { |
1da177e4 | 1054 | if (schedule) { |
c4028958 | 1055 | INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work); |
ce8e922c | 1056 | queue_work(xfslogd_workqueue, &bp->b_iodone_work); |
1da177e4 | 1057 | } else { |
c4028958 | 1058 | xfs_buf_iodone_work(&bp->b_iodone_work); |
1da177e4 LT |
1059 | } |
1060 | } else { | |
1813dd64 | 1061 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); |
b4dd330b | 1062 | complete(&bp->b_iowait); |
1da177e4 LT |
1063 | } |
1064 | } | |
1065 | ||
1da177e4 | 1066 | void |
ce8e922c NS |
1067 | xfs_buf_ioerror( |
1068 | xfs_buf_t *bp, | |
1069 | int error) | |
1da177e4 LT |
1070 | { |
1071 | ASSERT(error >= 0 && error <= 0xffff); | |
ce8e922c | 1072 | bp->b_error = (unsigned short)error; |
0b1b213f | 1073 | trace_xfs_buf_ioerror(bp, error, _RET_IP_); |
1da177e4 LT |
1074 | } |
1075 | ||
901796af CH |
1076 | void |
1077 | xfs_buf_ioerror_alert( | |
1078 | struct xfs_buf *bp, | |
1079 | const char *func) | |
1080 | { | |
1081 | xfs_alert(bp->b_target->bt_mount, | |
aa0e8833 DC |
1082 | "metadata I/O error: block 0x%llx (\"%s\") error %d numblks %d", |
1083 | (__uint64_t)XFS_BUF_ADDR(bp), func, bp->b_error, bp->b_length); | |
901796af CH |
1084 | } |
1085 | ||
4e23471a CH |
1086 | /* |
1087 | * Called when we want to stop a buffer from getting written or read. | |
1a1a3e97 | 1088 | * We attach the EIO error, muck with its flags, and call xfs_buf_ioend |
4e23471a CH |
1089 | * so that the proper iodone callbacks get called. |
1090 | */ | |
1091 | STATIC int | |
1092 | xfs_bioerror( | |
1093 | xfs_buf_t *bp) | |
1094 | { | |
1095 | #ifdef XFSERRORDEBUG | |
1096 | ASSERT(XFS_BUF_ISREAD(bp) || bp->b_iodone); | |
1097 | #endif | |
1098 | ||
1099 | /* | |
1100 | * No need to wait until the buffer is unpinned, we aren't flushing it. | |
1101 | */ | |
5a52c2a5 | 1102 | xfs_buf_ioerror(bp, EIO); |
4e23471a CH |
1103 | |
1104 | /* | |
1a1a3e97 | 1105 | * We're calling xfs_buf_ioend, so delete XBF_DONE flag. |
4e23471a CH |
1106 | */ |
1107 | XFS_BUF_UNREAD(bp); | |
4e23471a | 1108 | XFS_BUF_UNDONE(bp); |
c867cb61 | 1109 | xfs_buf_stale(bp); |
4e23471a | 1110 | |
1a1a3e97 | 1111 | xfs_buf_ioend(bp, 0); |
4e23471a CH |
1112 | |
1113 | return EIO; | |
1114 | } | |
1115 | ||
1116 | /* | |
1117 | * Same as xfs_bioerror, except that we are releasing the buffer | |
1a1a3e97 | 1118 | * here ourselves, and avoiding the xfs_buf_ioend call. |
4e23471a CH |
1119 | * This is meant for userdata errors; metadata bufs come with |
1120 | * iodone functions attached, so that we can track down errors. | |
1121 | */ | |
1122 | STATIC int | |
1123 | xfs_bioerror_relse( | |
1124 | struct xfs_buf *bp) | |
1125 | { | |
ed43233b | 1126 | int64_t fl = bp->b_flags; |
4e23471a CH |
1127 | /* |
1128 | * No need to wait until the buffer is unpinned. | |
1129 | * We aren't flushing it. | |
1130 | * | |
1131 | * chunkhold expects B_DONE to be set, whether | |
1132 | * we actually finish the I/O or not. We don't want to | |
1133 | * change that interface. | |
1134 | */ | |
1135 | XFS_BUF_UNREAD(bp); | |
4e23471a | 1136 | XFS_BUF_DONE(bp); |
c867cb61 | 1137 | xfs_buf_stale(bp); |
cb669ca5 | 1138 | bp->b_iodone = NULL; |
0cadda1c | 1139 | if (!(fl & XBF_ASYNC)) { |
4e23471a CH |
1140 | /* |
1141 | * Mark b_error and B_ERROR _both_. | |
1142 | * Lot's of chunkcache code assumes that. | |
1143 | * There's no reason to mark error for | |
1144 | * ASYNC buffers. | |
1145 | */ | |
5a52c2a5 | 1146 | xfs_buf_ioerror(bp, EIO); |
5fde0326 | 1147 | complete(&bp->b_iowait); |
4e23471a CH |
1148 | } else { |
1149 | xfs_buf_relse(bp); | |
1150 | } | |
1151 | ||
1152 | return EIO; | |
1153 | } | |
1154 | ||
a2dcf5df | 1155 | STATIC int |
4e23471a CH |
1156 | xfs_bdstrat_cb( |
1157 | struct xfs_buf *bp) | |
1158 | { | |
ebad861b | 1159 | if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) { |
4e23471a CH |
1160 | trace_xfs_bdstrat_shut(bp, _RET_IP_); |
1161 | /* | |
1162 | * Metadata write that didn't get logged but | |
1163 | * written delayed anyway. These aren't associated | |
1164 | * with a transaction, and can be ignored. | |
1165 | */ | |
1166 | if (!bp->b_iodone && !XFS_BUF_ISREAD(bp)) | |
1167 | return xfs_bioerror_relse(bp); | |
1168 | else | |
1169 | return xfs_bioerror(bp); | |
1170 | } | |
1171 | ||
1172 | xfs_buf_iorequest(bp); | |
1173 | return 0; | |
1174 | } | |
1175 | ||
a2dcf5df CH |
1176 | int |
1177 | xfs_bwrite( | |
1178 | struct xfs_buf *bp) | |
1179 | { | |
1180 | int error; | |
1181 | ||
1182 | ASSERT(xfs_buf_islocked(bp)); | |
1183 | ||
1184 | bp->b_flags |= XBF_WRITE; | |
1185 | bp->b_flags &= ~(XBF_ASYNC | XBF_READ | _XBF_DELWRI_Q); | |
1186 | ||
1187 | xfs_bdstrat_cb(bp); | |
1188 | ||
1189 | error = xfs_buf_iowait(bp); | |
1190 | if (error) { | |
1191 | xfs_force_shutdown(bp->b_target->bt_mount, | |
1192 | SHUTDOWN_META_IO_ERROR); | |
1193 | } | |
1194 | return error; | |
1195 | } | |
1196 | ||
4e23471a CH |
1197 | /* |
1198 | * Wrapper around bdstrat so that we can stop data from going to disk in case | |
1199 | * we are shutting down the filesystem. Typically user data goes thru this | |
1200 | * path; one of the exceptions is the superblock. | |
1201 | */ | |
1202 | void | |
1203 | xfsbdstrat( | |
1204 | struct xfs_mount *mp, | |
1205 | struct xfs_buf *bp) | |
1206 | { | |
1207 | if (XFS_FORCED_SHUTDOWN(mp)) { | |
1208 | trace_xfs_bdstrat_shut(bp, _RET_IP_); | |
1209 | xfs_bioerror_relse(bp); | |
1210 | return; | |
1211 | } | |
1212 | ||
1213 | xfs_buf_iorequest(bp); | |
1214 | } | |
1215 | ||
b8f82a4a | 1216 | STATIC void |
ce8e922c NS |
1217 | _xfs_buf_ioend( |
1218 | xfs_buf_t *bp, | |
1da177e4 LT |
1219 | int schedule) |
1220 | { | |
0e6e847f | 1221 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) |
ce8e922c | 1222 | xfs_buf_ioend(bp, schedule); |
1da177e4 LT |
1223 | } |
1224 | ||
782e3b3b | 1225 | STATIC void |
ce8e922c | 1226 | xfs_buf_bio_end_io( |
1da177e4 | 1227 | struct bio *bio, |
1da177e4 LT |
1228 | int error) |
1229 | { | |
ce8e922c | 1230 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1da177e4 | 1231 | |
37eb17e6 DC |
1232 | /* |
1233 | * don't overwrite existing errors - otherwise we can lose errors on | |
1234 | * buffers that require multiple bios to complete. | |
1235 | */ | |
1236 | if (!bp->b_error) | |
1237 | xfs_buf_ioerror(bp, -error); | |
1da177e4 | 1238 | |
37eb17e6 | 1239 | if (!bp->b_error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ)) |
73c77e2c JB |
1240 | invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp)); |
1241 | ||
ce8e922c | 1242 | _xfs_buf_ioend(bp, 1); |
1da177e4 | 1243 | bio_put(bio); |
1da177e4 LT |
1244 | } |
1245 | ||
3e85c868 DC |
1246 | static void |
1247 | xfs_buf_ioapply_map( | |
1248 | struct xfs_buf *bp, | |
1249 | int map, | |
1250 | int *buf_offset, | |
1251 | int *count, | |
1252 | int rw) | |
1da177e4 | 1253 | { |
3e85c868 DC |
1254 | int page_index; |
1255 | int total_nr_pages = bp->b_page_count; | |
1256 | int nr_pages; | |
1257 | struct bio *bio; | |
1258 | sector_t sector = bp->b_maps[map].bm_bn; | |
1259 | int size; | |
1260 | int offset; | |
1da177e4 | 1261 | |
ce8e922c | 1262 | total_nr_pages = bp->b_page_count; |
1da177e4 | 1263 | |
3e85c868 DC |
1264 | /* skip the pages in the buffer before the start offset */ |
1265 | page_index = 0; | |
1266 | offset = *buf_offset; | |
1267 | while (offset >= PAGE_SIZE) { | |
1268 | page_index++; | |
1269 | offset -= PAGE_SIZE; | |
f538d4da CH |
1270 | } |
1271 | ||
3e85c868 DC |
1272 | /* |
1273 | * Limit the IO size to the length of the current vector, and update the | |
1274 | * remaining IO count for the next time around. | |
1275 | */ | |
1276 | size = min_t(int, BBTOB(bp->b_maps[map].bm_len), *count); | |
1277 | *count -= size; | |
1278 | *buf_offset += size; | |
34951f5c | 1279 | |
1da177e4 | 1280 | next_chunk: |
ce8e922c | 1281 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1282 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1283 | if (nr_pages > total_nr_pages) | |
1284 | nr_pages = total_nr_pages; | |
1285 | ||
1286 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1287 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1288 | bio->bi_sector = sector; |
ce8e922c NS |
1289 | bio->bi_end_io = xfs_buf_bio_end_io; |
1290 | bio->bi_private = bp; | |
1da177e4 | 1291 | |
0e6e847f | 1292 | |
3e85c868 | 1293 | for (; size && nr_pages; nr_pages--, page_index++) { |
0e6e847f | 1294 | int rbytes, nbytes = PAGE_SIZE - offset; |
1da177e4 LT |
1295 | |
1296 | if (nbytes > size) | |
1297 | nbytes = size; | |
1298 | ||
3e85c868 DC |
1299 | rbytes = bio_add_page(bio, bp->b_pages[page_index], nbytes, |
1300 | offset); | |
ce8e922c | 1301 | if (rbytes < nbytes) |
1da177e4 LT |
1302 | break; |
1303 | ||
1304 | offset = 0; | |
aa0e8833 | 1305 | sector += BTOBB(nbytes); |
1da177e4 LT |
1306 | size -= nbytes; |
1307 | total_nr_pages--; | |
1308 | } | |
1309 | ||
1da177e4 | 1310 | if (likely(bio->bi_size)) { |
73c77e2c JB |
1311 | if (xfs_buf_is_vmapped(bp)) { |
1312 | flush_kernel_vmap_range(bp->b_addr, | |
1313 | xfs_buf_vmap_len(bp)); | |
1314 | } | |
1da177e4 LT |
1315 | submit_bio(rw, bio); |
1316 | if (size) | |
1317 | goto next_chunk; | |
1318 | } else { | |
37eb17e6 DC |
1319 | /* |
1320 | * This is guaranteed not to be the last io reference count | |
1321 | * because the caller (xfs_buf_iorequest) holds a count itself. | |
1322 | */ | |
1323 | atomic_dec(&bp->b_io_remaining); | |
ce8e922c | 1324 | xfs_buf_ioerror(bp, EIO); |
ec53d1db | 1325 | bio_put(bio); |
1da177e4 | 1326 | } |
3e85c868 DC |
1327 | |
1328 | } | |
1329 | ||
1330 | STATIC void | |
1331 | _xfs_buf_ioapply( | |
1332 | struct xfs_buf *bp) | |
1333 | { | |
1334 | struct blk_plug plug; | |
1335 | int rw; | |
1336 | int offset; | |
1337 | int size; | |
1338 | int i; | |
1339 | ||
c163f9a1 DC |
1340 | /* |
1341 | * Make sure we capture only current IO errors rather than stale errors | |
1342 | * left over from previous use of the buffer (e.g. failed readahead). | |
1343 | */ | |
1344 | bp->b_error = 0; | |
1345 | ||
3e85c868 DC |
1346 | if (bp->b_flags & XBF_WRITE) { |
1347 | if (bp->b_flags & XBF_SYNCIO) | |
1348 | rw = WRITE_SYNC; | |
1349 | else | |
1350 | rw = WRITE; | |
1351 | if (bp->b_flags & XBF_FUA) | |
1352 | rw |= REQ_FUA; | |
1353 | if (bp->b_flags & XBF_FLUSH) | |
1354 | rw |= REQ_FLUSH; | |
1813dd64 DC |
1355 | |
1356 | /* | |
1357 | * Run the write verifier callback function if it exists. If | |
1358 | * this function fails it will mark the buffer with an error and | |
1359 | * the IO should not be dispatched. | |
1360 | */ | |
1361 | if (bp->b_ops) { | |
1362 | bp->b_ops->verify_write(bp); | |
1363 | if (bp->b_error) { | |
1364 | xfs_force_shutdown(bp->b_target->bt_mount, | |
1365 | SHUTDOWN_CORRUPT_INCORE); | |
1366 | return; | |
1367 | } | |
1368 | } | |
3e85c868 DC |
1369 | } else if (bp->b_flags & XBF_READ_AHEAD) { |
1370 | rw = READA; | |
1371 | } else { | |
1372 | rw = READ; | |
1373 | } | |
1374 | ||
1375 | /* we only use the buffer cache for meta-data */ | |
1376 | rw |= REQ_META; | |
1377 | ||
1378 | /* | |
1379 | * Walk all the vectors issuing IO on them. Set up the initial offset | |
1380 | * into the buffer and the desired IO size before we start - | |
1381 | * _xfs_buf_ioapply_vec() will modify them appropriately for each | |
1382 | * subsequent call. | |
1383 | */ | |
1384 | offset = bp->b_offset; | |
1385 | size = BBTOB(bp->b_io_length); | |
1386 | blk_start_plug(&plug); | |
1387 | for (i = 0; i < bp->b_map_count; i++) { | |
1388 | xfs_buf_ioapply_map(bp, i, &offset, &size, rw); | |
1389 | if (bp->b_error) | |
1390 | break; | |
1391 | if (size <= 0) | |
1392 | break; /* all done */ | |
1393 | } | |
1394 | blk_finish_plug(&plug); | |
1da177e4 LT |
1395 | } |
1396 | ||
0e95f19a | 1397 | void |
ce8e922c NS |
1398 | xfs_buf_iorequest( |
1399 | xfs_buf_t *bp) | |
1da177e4 | 1400 | { |
0b1b213f | 1401 | trace_xfs_buf_iorequest(bp, _RET_IP_); |
1da177e4 | 1402 | |
43ff2122 | 1403 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); |
1da177e4 | 1404 | |
375ec69d | 1405 | if (bp->b_flags & XBF_WRITE) |
ce8e922c | 1406 | xfs_buf_wait_unpin(bp); |
ce8e922c | 1407 | xfs_buf_hold(bp); |
1da177e4 LT |
1408 | |
1409 | /* Set the count to 1 initially, this will stop an I/O | |
1410 | * completion callout which happens before we have started | |
ce8e922c | 1411 | * all the I/O from calling xfs_buf_ioend too early. |
1da177e4 | 1412 | */ |
ce8e922c NS |
1413 | atomic_set(&bp->b_io_remaining, 1); |
1414 | _xfs_buf_ioapply(bp); | |
08023d6d | 1415 | _xfs_buf_ioend(bp, 1); |
1da177e4 | 1416 | |
ce8e922c | 1417 | xfs_buf_rele(bp); |
1da177e4 LT |
1418 | } |
1419 | ||
1420 | /* | |
0e95f19a DC |
1421 | * Waits for I/O to complete on the buffer supplied. It returns immediately if |
1422 | * no I/O is pending or there is already a pending error on the buffer. It | |
1423 | * returns the I/O error code, if any, or 0 if there was no error. | |
1da177e4 LT |
1424 | */ |
1425 | int | |
ce8e922c NS |
1426 | xfs_buf_iowait( |
1427 | xfs_buf_t *bp) | |
1da177e4 | 1428 | { |
0b1b213f CH |
1429 | trace_xfs_buf_iowait(bp, _RET_IP_); |
1430 | ||
0e95f19a DC |
1431 | if (!bp->b_error) |
1432 | wait_for_completion(&bp->b_iowait); | |
0b1b213f CH |
1433 | |
1434 | trace_xfs_buf_iowait_done(bp, _RET_IP_); | |
ce8e922c | 1435 | return bp->b_error; |
1da177e4 LT |
1436 | } |
1437 | ||
ce8e922c NS |
1438 | xfs_caddr_t |
1439 | xfs_buf_offset( | |
1440 | xfs_buf_t *bp, | |
1da177e4 LT |
1441 | size_t offset) |
1442 | { | |
1443 | struct page *page; | |
1444 | ||
611c9946 | 1445 | if (bp->b_addr) |
62926044 | 1446 | return bp->b_addr + offset; |
1da177e4 | 1447 | |
ce8e922c | 1448 | offset += bp->b_offset; |
0e6e847f DC |
1449 | page = bp->b_pages[offset >> PAGE_SHIFT]; |
1450 | return (xfs_caddr_t)page_address(page) + (offset & (PAGE_SIZE-1)); | |
1da177e4 LT |
1451 | } |
1452 | ||
1453 | /* | |
1da177e4 LT |
1454 | * Move data into or out of a buffer. |
1455 | */ | |
1456 | void | |
ce8e922c NS |
1457 | xfs_buf_iomove( |
1458 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1459 | size_t boff, /* starting buffer offset */ |
1460 | size_t bsize, /* length to copy */ | |
b9c48649 | 1461 | void *data, /* data address */ |
ce8e922c | 1462 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 | 1463 | { |
795cac72 | 1464 | size_t bend; |
1da177e4 LT |
1465 | |
1466 | bend = boff + bsize; | |
1467 | while (boff < bend) { | |
795cac72 DC |
1468 | struct page *page; |
1469 | int page_index, page_offset, csize; | |
1470 | ||
1471 | page_index = (boff + bp->b_offset) >> PAGE_SHIFT; | |
1472 | page_offset = (boff + bp->b_offset) & ~PAGE_MASK; | |
1473 | page = bp->b_pages[page_index]; | |
1474 | csize = min_t(size_t, PAGE_SIZE - page_offset, | |
1475 | BBTOB(bp->b_io_length) - boff); | |
1da177e4 | 1476 | |
795cac72 | 1477 | ASSERT((csize + page_offset) <= PAGE_SIZE); |
1da177e4 LT |
1478 | |
1479 | switch (mode) { | |
ce8e922c | 1480 | case XBRW_ZERO: |
795cac72 | 1481 | memset(page_address(page) + page_offset, 0, csize); |
1da177e4 | 1482 | break; |
ce8e922c | 1483 | case XBRW_READ: |
795cac72 | 1484 | memcpy(data, page_address(page) + page_offset, csize); |
1da177e4 | 1485 | break; |
ce8e922c | 1486 | case XBRW_WRITE: |
795cac72 | 1487 | memcpy(page_address(page) + page_offset, data, csize); |
1da177e4 LT |
1488 | } |
1489 | ||
1490 | boff += csize; | |
1491 | data += csize; | |
1492 | } | |
1493 | } | |
1494 | ||
1495 | /* | |
ce8e922c | 1496 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1497 | */ |
1498 | ||
1499 | /* | |
430cbeb8 DC |
1500 | * Wait for any bufs with callbacks that have been submitted but have not yet |
1501 | * returned. These buffers will have an elevated hold count, so wait on those | |
1502 | * while freeing all the buffers only held by the LRU. | |
1da177e4 LT |
1503 | */ |
1504 | void | |
1505 | xfs_wait_buftarg( | |
74f75a0c | 1506 | struct xfs_buftarg *btp) |
1da177e4 | 1507 | { |
430cbeb8 DC |
1508 | struct xfs_buf *bp; |
1509 | ||
1510 | restart: | |
1511 | spin_lock(&btp->bt_lru_lock); | |
1512 | while (!list_empty(&btp->bt_lru)) { | |
1513 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1514 | if (atomic_read(&bp->b_hold) > 1) { | |
3b19034d DC |
1515 | trace_xfs_buf_wait_buftarg(bp, _RET_IP_); |
1516 | list_move_tail(&bp->b_lru, &btp->bt_lru); | |
430cbeb8 | 1517 | spin_unlock(&btp->bt_lru_lock); |
26af6552 | 1518 | delay(100); |
430cbeb8 | 1519 | goto restart; |
1da177e4 | 1520 | } |
430cbeb8 | 1521 | /* |
90802ed9 | 1522 | * clear the LRU reference count so the buffer doesn't get |
430cbeb8 DC |
1523 | * ignored in xfs_buf_rele(). |
1524 | */ | |
1525 | atomic_set(&bp->b_lru_ref, 0); | |
1526 | spin_unlock(&btp->bt_lru_lock); | |
1527 | xfs_buf_rele(bp); | |
1528 | spin_lock(&btp->bt_lru_lock); | |
1da177e4 | 1529 | } |
430cbeb8 | 1530 | spin_unlock(&btp->bt_lru_lock); |
1da177e4 LT |
1531 | } |
1532 | ||
ff57ab21 DC |
1533 | int |
1534 | xfs_buftarg_shrink( | |
1535 | struct shrinker *shrink, | |
1495f230 | 1536 | struct shrink_control *sc) |
a6867a68 | 1537 | { |
ff57ab21 DC |
1538 | struct xfs_buftarg *btp = container_of(shrink, |
1539 | struct xfs_buftarg, bt_shrinker); | |
430cbeb8 | 1540 | struct xfs_buf *bp; |
1495f230 | 1541 | int nr_to_scan = sc->nr_to_scan; |
430cbeb8 DC |
1542 | LIST_HEAD(dispose); |
1543 | ||
1544 | if (!nr_to_scan) | |
1545 | return btp->bt_lru_nr; | |
1546 | ||
1547 | spin_lock(&btp->bt_lru_lock); | |
1548 | while (!list_empty(&btp->bt_lru)) { | |
1549 | if (nr_to_scan-- <= 0) | |
1550 | break; | |
1551 | ||
1552 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1553 | ||
1554 | /* | |
1555 | * Decrement the b_lru_ref count unless the value is already | |
1556 | * zero. If the value is already zero, we need to reclaim the | |
1557 | * buffer, otherwise it gets another trip through the LRU. | |
1558 | */ | |
1559 | if (!atomic_add_unless(&bp->b_lru_ref, -1, 0)) { | |
1560 | list_move_tail(&bp->b_lru, &btp->bt_lru); | |
1561 | continue; | |
1562 | } | |
1563 | ||
1564 | /* | |
1565 | * remove the buffer from the LRU now to avoid needing another | |
1566 | * lock round trip inside xfs_buf_rele(). | |
1567 | */ | |
1568 | list_move(&bp->b_lru, &dispose); | |
1569 | btp->bt_lru_nr--; | |
6fb8a90a | 1570 | bp->b_lru_flags |= _XBF_LRU_DISPOSE; |
ff57ab21 | 1571 | } |
430cbeb8 DC |
1572 | spin_unlock(&btp->bt_lru_lock); |
1573 | ||
1574 | while (!list_empty(&dispose)) { | |
1575 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); | |
1576 | list_del_init(&bp->b_lru); | |
1577 | xfs_buf_rele(bp); | |
1578 | } | |
1579 | ||
1580 | return btp->bt_lru_nr; | |
a6867a68 DC |
1581 | } |
1582 | ||
1da177e4 LT |
1583 | void |
1584 | xfs_free_buftarg( | |
b7963133 CH |
1585 | struct xfs_mount *mp, |
1586 | struct xfs_buftarg *btp) | |
1da177e4 | 1587 | { |
ff57ab21 DC |
1588 | unregister_shrinker(&btp->bt_shrinker); |
1589 | ||
b7963133 CH |
1590 | if (mp->m_flags & XFS_MOUNT_BARRIER) |
1591 | xfs_blkdev_issue_flush(btp); | |
a6867a68 | 1592 | |
f0e2d93c | 1593 | kmem_free(btp); |
1da177e4 LT |
1594 | } |
1595 | ||
1da177e4 LT |
1596 | STATIC int |
1597 | xfs_setsize_buftarg_flags( | |
1598 | xfs_buftarg_t *btp, | |
1599 | unsigned int blocksize, | |
1600 | unsigned int sectorsize, | |
1601 | int verbose) | |
1602 | { | |
ce8e922c NS |
1603 | btp->bt_bsize = blocksize; |
1604 | btp->bt_sshift = ffs(sectorsize) - 1; | |
1605 | btp->bt_smask = sectorsize - 1; | |
1da177e4 | 1606 | |
ce8e922c | 1607 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
02b102df CH |
1608 | char name[BDEVNAME_SIZE]; |
1609 | ||
1610 | bdevname(btp->bt_bdev, name); | |
1611 | ||
4f10700a DC |
1612 | xfs_warn(btp->bt_mount, |
1613 | "Cannot set_blocksize to %u on device %s\n", | |
02b102df | 1614 | sectorsize, name); |
1da177e4 LT |
1615 | return EINVAL; |
1616 | } | |
1617 | ||
1da177e4 LT |
1618 | return 0; |
1619 | } | |
1620 | ||
1621 | /* | |
ce8e922c NS |
1622 | * When allocating the initial buffer target we have not yet |
1623 | * read in the superblock, so don't know what sized sectors | |
1624 | * are being used is at this early stage. Play safe. | |
1625 | */ | |
1da177e4 LT |
1626 | STATIC int |
1627 | xfs_setsize_buftarg_early( | |
1628 | xfs_buftarg_t *btp, | |
1629 | struct block_device *bdev) | |
1630 | { | |
1631 | return xfs_setsize_buftarg_flags(btp, | |
0e6e847f | 1632 | PAGE_SIZE, bdev_logical_block_size(bdev), 0); |
1da177e4 LT |
1633 | } |
1634 | ||
1635 | int | |
1636 | xfs_setsize_buftarg( | |
1637 | xfs_buftarg_t *btp, | |
1638 | unsigned int blocksize, | |
1639 | unsigned int sectorsize) | |
1640 | { | |
1641 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | |
1642 | } | |
1643 | ||
1da177e4 LT |
1644 | xfs_buftarg_t * |
1645 | xfs_alloc_buftarg( | |
ebad861b | 1646 | struct xfs_mount *mp, |
1da177e4 | 1647 | struct block_device *bdev, |
e2a07812 JE |
1648 | int external, |
1649 | const char *fsname) | |
1da177e4 LT |
1650 | { |
1651 | xfs_buftarg_t *btp; | |
1652 | ||
b17cb364 | 1653 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP | KM_NOFS); |
1da177e4 | 1654 | |
ebad861b | 1655 | btp->bt_mount = mp; |
ce8e922c NS |
1656 | btp->bt_dev = bdev->bd_dev; |
1657 | btp->bt_bdev = bdev; | |
0e6e847f DC |
1658 | btp->bt_bdi = blk_get_backing_dev_info(bdev); |
1659 | if (!btp->bt_bdi) | |
1660 | goto error; | |
1661 | ||
430cbeb8 DC |
1662 | INIT_LIST_HEAD(&btp->bt_lru); |
1663 | spin_lock_init(&btp->bt_lru_lock); | |
1da177e4 LT |
1664 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1665 | goto error; | |
ff57ab21 DC |
1666 | btp->bt_shrinker.shrink = xfs_buftarg_shrink; |
1667 | btp->bt_shrinker.seeks = DEFAULT_SEEKS; | |
1668 | register_shrinker(&btp->bt_shrinker); | |
1da177e4 LT |
1669 | return btp; |
1670 | ||
1671 | error: | |
f0e2d93c | 1672 | kmem_free(btp); |
1da177e4 LT |
1673 | return NULL; |
1674 | } | |
1675 | ||
1da177e4 | 1676 | /* |
43ff2122 CH |
1677 | * Add a buffer to the delayed write list. |
1678 | * | |
1679 | * This queues a buffer for writeout if it hasn't already been. Note that | |
1680 | * neither this routine nor the buffer list submission functions perform | |
1681 | * any internal synchronization. It is expected that the lists are thread-local | |
1682 | * to the callers. | |
1683 | * | |
1684 | * Returns true if we queued up the buffer, or false if it already had | |
1685 | * been on the buffer list. | |
1da177e4 | 1686 | */ |
43ff2122 | 1687 | bool |
ce8e922c | 1688 | xfs_buf_delwri_queue( |
43ff2122 CH |
1689 | struct xfs_buf *bp, |
1690 | struct list_head *list) | |
1da177e4 | 1691 | { |
43ff2122 | 1692 | ASSERT(xfs_buf_islocked(bp)); |
5a8ee6ba | 1693 | ASSERT(!(bp->b_flags & XBF_READ)); |
1da177e4 | 1694 | |
43ff2122 CH |
1695 | /* |
1696 | * If the buffer is already marked delwri it already is queued up | |
1697 | * by someone else for imediate writeout. Just ignore it in that | |
1698 | * case. | |
1699 | */ | |
1700 | if (bp->b_flags & _XBF_DELWRI_Q) { | |
1701 | trace_xfs_buf_delwri_queued(bp, _RET_IP_); | |
1702 | return false; | |
1da177e4 | 1703 | } |
1da177e4 | 1704 | |
43ff2122 | 1705 | trace_xfs_buf_delwri_queue(bp, _RET_IP_); |
d808f617 DC |
1706 | |
1707 | /* | |
43ff2122 CH |
1708 | * If a buffer gets written out synchronously or marked stale while it |
1709 | * is on a delwri list we lazily remove it. To do this, the other party | |
1710 | * clears the _XBF_DELWRI_Q flag but otherwise leaves the buffer alone. | |
1711 | * It remains referenced and on the list. In a rare corner case it | |
1712 | * might get readded to a delwri list after the synchronous writeout, in | |
1713 | * which case we need just need to re-add the flag here. | |
d808f617 | 1714 | */ |
43ff2122 CH |
1715 | bp->b_flags |= _XBF_DELWRI_Q; |
1716 | if (list_empty(&bp->b_list)) { | |
1717 | atomic_inc(&bp->b_hold); | |
1718 | list_add_tail(&bp->b_list, list); | |
585e6d88 | 1719 | } |
585e6d88 | 1720 | |
43ff2122 | 1721 | return true; |
585e6d88 DC |
1722 | } |
1723 | ||
089716aa DC |
1724 | /* |
1725 | * Compare function is more complex than it needs to be because | |
1726 | * the return value is only 32 bits and we are doing comparisons | |
1727 | * on 64 bit values | |
1728 | */ | |
1729 | static int | |
1730 | xfs_buf_cmp( | |
1731 | void *priv, | |
1732 | struct list_head *a, | |
1733 | struct list_head *b) | |
1734 | { | |
1735 | struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list); | |
1736 | struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); | |
1737 | xfs_daddr_t diff; | |
1738 | ||
f4b42421 | 1739 | diff = ap->b_maps[0].bm_bn - bp->b_maps[0].bm_bn; |
089716aa DC |
1740 | if (diff < 0) |
1741 | return -1; | |
1742 | if (diff > 0) | |
1743 | return 1; | |
1744 | return 0; | |
1745 | } | |
1746 | ||
43ff2122 CH |
1747 | static int |
1748 | __xfs_buf_delwri_submit( | |
1749 | struct list_head *buffer_list, | |
1750 | struct list_head *io_list, | |
1751 | bool wait) | |
1da177e4 | 1752 | { |
43ff2122 CH |
1753 | struct blk_plug plug; |
1754 | struct xfs_buf *bp, *n; | |
1755 | int pinned = 0; | |
1756 | ||
1757 | list_for_each_entry_safe(bp, n, buffer_list, b_list) { | |
1758 | if (!wait) { | |
1759 | if (xfs_buf_ispinned(bp)) { | |
1760 | pinned++; | |
1761 | continue; | |
1762 | } | |
1763 | if (!xfs_buf_trylock(bp)) | |
1764 | continue; | |
1765 | } else { | |
1766 | xfs_buf_lock(bp); | |
1767 | } | |
978c7b2f | 1768 | |
43ff2122 CH |
1769 | /* |
1770 | * Someone else might have written the buffer synchronously or | |
1771 | * marked it stale in the meantime. In that case only the | |
1772 | * _XBF_DELWRI_Q flag got cleared, and we have to drop the | |
1773 | * reference and remove it from the list here. | |
1774 | */ | |
1775 | if (!(bp->b_flags & _XBF_DELWRI_Q)) { | |
1776 | list_del_init(&bp->b_list); | |
1777 | xfs_buf_relse(bp); | |
1778 | continue; | |
1779 | } | |
c9c12971 | 1780 | |
43ff2122 CH |
1781 | list_move_tail(&bp->b_list, io_list); |
1782 | trace_xfs_buf_delwri_split(bp, _RET_IP_); | |
1783 | } | |
1da177e4 | 1784 | |
43ff2122 | 1785 | list_sort(NULL, io_list, xfs_buf_cmp); |
1da177e4 | 1786 | |
43ff2122 CH |
1787 | blk_start_plug(&plug); |
1788 | list_for_each_entry_safe(bp, n, io_list, b_list) { | |
1789 | bp->b_flags &= ~(_XBF_DELWRI_Q | XBF_ASYNC); | |
1790 | bp->b_flags |= XBF_WRITE; | |
a1b7ea5d | 1791 | |
43ff2122 CH |
1792 | if (!wait) { |
1793 | bp->b_flags |= XBF_ASYNC; | |
ce8e922c | 1794 | list_del_init(&bp->b_list); |
1da177e4 | 1795 | } |
43ff2122 CH |
1796 | xfs_bdstrat_cb(bp); |
1797 | } | |
1798 | blk_finish_plug(&plug); | |
1da177e4 | 1799 | |
43ff2122 | 1800 | return pinned; |
1da177e4 LT |
1801 | } |
1802 | ||
1803 | /* | |
43ff2122 CH |
1804 | * Write out a buffer list asynchronously. |
1805 | * | |
1806 | * This will take the @buffer_list, write all non-locked and non-pinned buffers | |
1807 | * out and not wait for I/O completion on any of the buffers. This interface | |
1808 | * is only safely useable for callers that can track I/O completion by higher | |
1809 | * level means, e.g. AIL pushing as the @buffer_list is consumed in this | |
1810 | * function. | |
1da177e4 LT |
1811 | */ |
1812 | int | |
43ff2122 CH |
1813 | xfs_buf_delwri_submit_nowait( |
1814 | struct list_head *buffer_list) | |
1da177e4 | 1815 | { |
43ff2122 CH |
1816 | LIST_HEAD (io_list); |
1817 | return __xfs_buf_delwri_submit(buffer_list, &io_list, false); | |
1818 | } | |
1da177e4 | 1819 | |
43ff2122 CH |
1820 | /* |
1821 | * Write out a buffer list synchronously. | |
1822 | * | |
1823 | * This will take the @buffer_list, write all buffers out and wait for I/O | |
1824 | * completion on all of the buffers. @buffer_list is consumed by the function, | |
1825 | * so callers must have some other way of tracking buffers if they require such | |
1826 | * functionality. | |
1827 | */ | |
1828 | int | |
1829 | xfs_buf_delwri_submit( | |
1830 | struct list_head *buffer_list) | |
1831 | { | |
1832 | LIST_HEAD (io_list); | |
1833 | int error = 0, error2; | |
1834 | struct xfs_buf *bp; | |
1da177e4 | 1835 | |
43ff2122 | 1836 | __xfs_buf_delwri_submit(buffer_list, &io_list, true); |
1da177e4 | 1837 | |
43ff2122 CH |
1838 | /* Wait for IO to complete. */ |
1839 | while (!list_empty(&io_list)) { | |
1840 | bp = list_first_entry(&io_list, struct xfs_buf, b_list); | |
a1b7ea5d | 1841 | |
089716aa | 1842 | list_del_init(&bp->b_list); |
43ff2122 CH |
1843 | error2 = xfs_buf_iowait(bp); |
1844 | xfs_buf_relse(bp); | |
1845 | if (!error) | |
1846 | error = error2; | |
1da177e4 LT |
1847 | } |
1848 | ||
43ff2122 | 1849 | return error; |
1da177e4 LT |
1850 | } |
1851 | ||
04d8b284 | 1852 | int __init |
ce8e922c | 1853 | xfs_buf_init(void) |
1da177e4 | 1854 | { |
8758280f NS |
1855 | xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf", |
1856 | KM_ZONE_HWALIGN, NULL); | |
ce8e922c | 1857 | if (!xfs_buf_zone) |
0b1b213f | 1858 | goto out; |
04d8b284 | 1859 | |
51749e47 | 1860 | xfslogd_workqueue = alloc_workqueue("xfslogd", |
6370a6ad | 1861 | WQ_MEM_RECLAIM | WQ_HIGHPRI, 1); |
23ea4032 | 1862 | if (!xfslogd_workqueue) |
04d8b284 | 1863 | goto out_free_buf_zone; |
1da177e4 | 1864 | |
23ea4032 | 1865 | return 0; |
1da177e4 | 1866 | |
23ea4032 | 1867 | out_free_buf_zone: |
ce8e922c | 1868 | kmem_zone_destroy(xfs_buf_zone); |
0b1b213f | 1869 | out: |
8758280f | 1870 | return -ENOMEM; |
1da177e4 LT |
1871 | } |
1872 | ||
1da177e4 | 1873 | void |
ce8e922c | 1874 | xfs_buf_terminate(void) |
1da177e4 | 1875 | { |
04d8b284 | 1876 | destroy_workqueue(xfslogd_workqueue); |
ce8e922c | 1877 | kmem_zone_destroy(xfs_buf_zone); |
1da177e4 | 1878 | } |