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Commit | Line | Data |
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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 DC |
489 | xfs_daddr_t blkno = map[0].bm_bn; |
490 | int numblks = 0; | |
491 | int i; | |
1da177e4 | 492 | |
3e85c868 DC |
493 | for (i = 0; i < nmaps; i++) |
494 | numblks += map[i].bm_len; | |
e70b73f8 | 495 | numbytes = BBTOB(numblks); |
1da177e4 LT |
496 | |
497 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
e70b73f8 | 498 | ASSERT(!(numbytes < (1 << btp->bt_sshift))); |
de1cbee4 | 499 | ASSERT(!(BBTOB(blkno) & (xfs_off_t)btp->bt_smask)); |
1da177e4 | 500 | |
74f75a0c DC |
501 | /* get tree root */ |
502 | pag = xfs_perag_get(btp->bt_mount, | |
e70b73f8 | 503 | xfs_daddr_to_agno(btp->bt_mount, blkno)); |
74f75a0c DC |
504 | |
505 | /* walk tree */ | |
506 | spin_lock(&pag->pag_buf_lock); | |
507 | rbp = &pag->pag_buf_tree.rb_node; | |
508 | parent = NULL; | |
509 | bp = NULL; | |
510 | while (*rbp) { | |
511 | parent = *rbp; | |
512 | bp = rb_entry(parent, struct xfs_buf, b_rbnode); | |
513 | ||
de1cbee4 | 514 | if (blkno < bp->b_bn) |
74f75a0c | 515 | rbp = &(*rbp)->rb_left; |
de1cbee4 | 516 | else if (blkno > bp->b_bn) |
74f75a0c DC |
517 | rbp = &(*rbp)->rb_right; |
518 | else { | |
519 | /* | |
de1cbee4 | 520 | * found a block number match. If the range doesn't |
74f75a0c DC |
521 | * match, the only way this is allowed is if the buffer |
522 | * in the cache is stale and the transaction that made | |
523 | * it stale has not yet committed. i.e. we are | |
524 | * reallocating a busy extent. Skip this buffer and | |
525 | * continue searching to the right for an exact match. | |
526 | */ | |
4e94b71b | 527 | if (bp->b_length != numblks) { |
74f75a0c DC |
528 | ASSERT(bp->b_flags & XBF_STALE); |
529 | rbp = &(*rbp)->rb_right; | |
530 | continue; | |
531 | } | |
ce8e922c | 532 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
533 | goto found; |
534 | } | |
535 | } | |
536 | ||
537 | /* No match found */ | |
ce8e922c | 538 | if (new_bp) { |
74f75a0c DC |
539 | rb_link_node(&new_bp->b_rbnode, parent, rbp); |
540 | rb_insert_color(&new_bp->b_rbnode, &pag->pag_buf_tree); | |
541 | /* the buffer keeps the perag reference until it is freed */ | |
542 | new_bp->b_pag = pag; | |
543 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 544 | } else { |
ce8e922c | 545 | XFS_STATS_INC(xb_miss_locked); |
74f75a0c DC |
546 | spin_unlock(&pag->pag_buf_lock); |
547 | xfs_perag_put(pag); | |
1da177e4 | 548 | } |
ce8e922c | 549 | return new_bp; |
1da177e4 LT |
550 | |
551 | found: | |
74f75a0c DC |
552 | spin_unlock(&pag->pag_buf_lock); |
553 | xfs_perag_put(pag); | |
1da177e4 | 554 | |
0c842ad4 CH |
555 | if (!xfs_buf_trylock(bp)) { |
556 | if (flags & XBF_TRYLOCK) { | |
ce8e922c NS |
557 | xfs_buf_rele(bp); |
558 | XFS_STATS_INC(xb_busy_locked); | |
559 | return NULL; | |
1da177e4 | 560 | } |
0c842ad4 CH |
561 | xfs_buf_lock(bp); |
562 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 LT |
563 | } |
564 | ||
0e6e847f DC |
565 | /* |
566 | * if the buffer is stale, clear all the external state associated with | |
567 | * it. We need to keep flags such as how we allocated the buffer memory | |
568 | * intact here. | |
569 | */ | |
ce8e922c NS |
570 | if (bp->b_flags & XBF_STALE) { |
571 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
cfb02852 | 572 | ASSERT(bp->b_iodone == NULL); |
611c9946 | 573 | bp->b_flags &= _XBF_KMEM | _XBF_PAGES; |
1813dd64 | 574 | bp->b_ops = NULL; |
2f926587 | 575 | } |
0b1b213f CH |
576 | |
577 | trace_xfs_buf_find(bp, flags, _RET_IP_); | |
ce8e922c NS |
578 | XFS_STATS_INC(xb_get_locked); |
579 | return bp; | |
1da177e4 LT |
580 | } |
581 | ||
582 | /* | |
3815832a DC |
583 | * Assembles a buffer covering the specified range. The code is optimised for |
584 | * cache hits, as metadata intensive workloads will see 3 orders of magnitude | |
585 | * more hits than misses. | |
1da177e4 | 586 | */ |
3815832a | 587 | struct xfs_buf * |
6dde2707 DC |
588 | xfs_buf_get_map( |
589 | struct xfs_buftarg *target, | |
590 | struct xfs_buf_map *map, | |
591 | int nmaps, | |
ce8e922c | 592 | xfs_buf_flags_t flags) |
1da177e4 | 593 | { |
3815832a DC |
594 | struct xfs_buf *bp; |
595 | struct xfs_buf *new_bp; | |
0e6e847f | 596 | int error = 0; |
1da177e4 | 597 | |
6dde2707 | 598 | bp = _xfs_buf_find(target, map, nmaps, flags, NULL); |
3815832a DC |
599 | if (likely(bp)) |
600 | goto found; | |
601 | ||
6dde2707 | 602 | new_bp = _xfs_buf_alloc(target, map, nmaps, flags); |
ce8e922c | 603 | if (unlikely(!new_bp)) |
1da177e4 LT |
604 | return NULL; |
605 | ||
fe2429b0 DC |
606 | error = xfs_buf_allocate_memory(new_bp, flags); |
607 | if (error) { | |
3e85c868 | 608 | xfs_buf_free(new_bp); |
fe2429b0 DC |
609 | return NULL; |
610 | } | |
611 | ||
6dde2707 | 612 | bp = _xfs_buf_find(target, map, nmaps, flags, new_bp); |
3815832a | 613 | if (!bp) { |
fe2429b0 | 614 | xfs_buf_free(new_bp); |
3815832a DC |
615 | return NULL; |
616 | } | |
617 | ||
fe2429b0 DC |
618 | if (bp != new_bp) |
619 | xfs_buf_free(new_bp); | |
1da177e4 | 620 | |
3815832a | 621 | found: |
611c9946 | 622 | if (!bp->b_addr) { |
ce8e922c | 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__); | |
a8acad70 DC |
627 | xfs_buf_relse(bp); |
628 | return NULL; | |
1da177e4 LT |
629 | } |
630 | } | |
631 | ||
ce8e922c | 632 | XFS_STATS_INC(xb_get); |
0b1b213f | 633 | trace_xfs_buf_get(bp, flags, _RET_IP_); |
ce8e922c | 634 | return bp; |
1da177e4 LT |
635 | } |
636 | ||
5d765b97 CH |
637 | STATIC int |
638 | _xfs_buf_read( | |
639 | xfs_buf_t *bp, | |
640 | xfs_buf_flags_t flags) | |
641 | { | |
43ff2122 | 642 | ASSERT(!(flags & XBF_WRITE)); |
f4b42421 | 643 | ASSERT(bp->b_maps[0].bm_bn != XFS_BUF_DADDR_NULL); |
5d765b97 | 644 | |
43ff2122 | 645 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD); |
1d5ae5df | 646 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD); |
5d765b97 | 647 | |
0e95f19a DC |
648 | xfs_buf_iorequest(bp); |
649 | if (flags & XBF_ASYNC) | |
650 | return 0; | |
ec53d1db | 651 | return xfs_buf_iowait(bp); |
5d765b97 CH |
652 | } |
653 | ||
1da177e4 | 654 | xfs_buf_t * |
6dde2707 DC |
655 | xfs_buf_read_map( |
656 | struct xfs_buftarg *target, | |
657 | struct xfs_buf_map *map, | |
658 | int nmaps, | |
c3f8fc73 | 659 | xfs_buf_flags_t flags, |
1813dd64 | 660 | const struct xfs_buf_ops *ops) |
1da177e4 | 661 | { |
6dde2707 | 662 | struct xfs_buf *bp; |
ce8e922c NS |
663 | |
664 | flags |= XBF_READ; | |
665 | ||
6dde2707 | 666 | bp = xfs_buf_get_map(target, map, nmaps, flags); |
ce8e922c | 667 | if (bp) { |
0b1b213f CH |
668 | trace_xfs_buf_read(bp, flags, _RET_IP_); |
669 | ||
ce8e922c | 670 | if (!XFS_BUF_ISDONE(bp)) { |
ce8e922c | 671 | XFS_STATS_INC(xb_get_read); |
1813dd64 | 672 | bp->b_ops = ops; |
5d765b97 | 673 | _xfs_buf_read(bp, flags); |
ce8e922c | 674 | } else if (flags & XBF_ASYNC) { |
1da177e4 LT |
675 | /* |
676 | * Read ahead call which is already satisfied, | |
677 | * drop the buffer | |
678 | */ | |
a8acad70 DC |
679 | xfs_buf_relse(bp); |
680 | return NULL; | |
1da177e4 | 681 | } else { |
1da177e4 | 682 | /* We do not want read in the flags */ |
ce8e922c | 683 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
684 | } |
685 | } | |
686 | ||
ce8e922c | 687 | return bp; |
1da177e4 LT |
688 | } |
689 | ||
1da177e4 | 690 | /* |
ce8e922c NS |
691 | * If we are not low on memory then do the readahead in a deadlock |
692 | * safe manner. | |
1da177e4 LT |
693 | */ |
694 | void | |
6dde2707 DC |
695 | xfs_buf_readahead_map( |
696 | struct xfs_buftarg *target, | |
697 | struct xfs_buf_map *map, | |
c3f8fc73 | 698 | int nmaps, |
1813dd64 | 699 | const struct xfs_buf_ops *ops) |
1da177e4 | 700 | { |
0e6e847f | 701 | if (bdi_read_congested(target->bt_bdi)) |
1da177e4 LT |
702 | return; |
703 | ||
6dde2707 | 704 | xfs_buf_read_map(target, map, nmaps, |
1813dd64 | 705 | XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD, ops); |
1da177e4 LT |
706 | } |
707 | ||
5adc94c2 DC |
708 | /* |
709 | * Read an uncached buffer from disk. Allocates and returns a locked | |
710 | * buffer containing the disk contents or nothing. | |
711 | */ | |
712 | struct xfs_buf * | |
713 | xfs_buf_read_uncached( | |
5adc94c2 DC |
714 | struct xfs_buftarg *target, |
715 | xfs_daddr_t daddr, | |
e70b73f8 | 716 | size_t numblks, |
c3f8fc73 | 717 | int flags, |
1813dd64 | 718 | const struct xfs_buf_ops *ops) |
5adc94c2 | 719 | { |
eab4e633 | 720 | struct xfs_buf *bp; |
5adc94c2 | 721 | |
e70b73f8 | 722 | bp = xfs_buf_get_uncached(target, numblks, flags); |
5adc94c2 DC |
723 | if (!bp) |
724 | return NULL; | |
725 | ||
726 | /* set up the buffer for a read IO */ | |
3e85c868 DC |
727 | ASSERT(bp->b_map_count == 1); |
728 | bp->b_bn = daddr; | |
729 | bp->b_maps[0].bm_bn = daddr; | |
cbb7baab | 730 | bp->b_flags |= XBF_READ; |
1813dd64 | 731 | bp->b_ops = ops; |
5adc94c2 | 732 | |
e70b73f8 | 733 | xfsbdstrat(target->bt_mount, bp); |
eab4e633 | 734 | xfs_buf_iowait(bp); |
5adc94c2 | 735 | return bp; |
1da177e4 LT |
736 | } |
737 | ||
44396476 DC |
738 | /* |
739 | * Return a buffer allocated as an empty buffer and associated to external | |
740 | * memory via xfs_buf_associate_memory() back to it's empty state. | |
741 | */ | |
742 | void | |
743 | xfs_buf_set_empty( | |
744 | struct xfs_buf *bp, | |
e70b73f8 | 745 | size_t numblks) |
44396476 DC |
746 | { |
747 | if (bp->b_pages) | |
748 | _xfs_buf_free_pages(bp); | |
749 | ||
750 | bp->b_pages = NULL; | |
751 | bp->b_page_count = 0; | |
752 | bp->b_addr = NULL; | |
4e94b71b | 753 | bp->b_length = numblks; |
aa0e8833 | 754 | bp->b_io_length = numblks; |
3e85c868 DC |
755 | |
756 | ASSERT(bp->b_map_count == 1); | |
44396476 | 757 | bp->b_bn = XFS_BUF_DADDR_NULL; |
3e85c868 DC |
758 | bp->b_maps[0].bm_bn = XFS_BUF_DADDR_NULL; |
759 | bp->b_maps[0].bm_len = bp->b_length; | |
44396476 DC |
760 | } |
761 | ||
1da177e4 LT |
762 | static inline struct page * |
763 | mem_to_page( | |
764 | void *addr) | |
765 | { | |
9e2779fa | 766 | if ((!is_vmalloc_addr(addr))) { |
1da177e4 LT |
767 | return virt_to_page(addr); |
768 | } else { | |
769 | return vmalloc_to_page(addr); | |
770 | } | |
771 | } | |
772 | ||
773 | int | |
ce8e922c NS |
774 | xfs_buf_associate_memory( |
775 | xfs_buf_t *bp, | |
1da177e4 LT |
776 | void *mem, |
777 | size_t len) | |
778 | { | |
779 | int rval; | |
780 | int i = 0; | |
d1afb678 LM |
781 | unsigned long pageaddr; |
782 | unsigned long offset; | |
783 | size_t buflen; | |
1da177e4 LT |
784 | int page_count; |
785 | ||
0e6e847f | 786 | pageaddr = (unsigned long)mem & PAGE_MASK; |
d1afb678 | 787 | offset = (unsigned long)mem - pageaddr; |
0e6e847f DC |
788 | buflen = PAGE_ALIGN(len + offset); |
789 | page_count = buflen >> PAGE_SHIFT; | |
1da177e4 LT |
790 | |
791 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
792 | if (bp->b_pages) |
793 | _xfs_buf_free_pages(bp); | |
1da177e4 | 794 | |
ce8e922c NS |
795 | bp->b_pages = NULL; |
796 | bp->b_addr = mem; | |
1da177e4 | 797 | |
aa5c158e | 798 | rval = _xfs_buf_get_pages(bp, page_count, 0); |
1da177e4 LT |
799 | if (rval) |
800 | return rval; | |
801 | ||
ce8e922c | 802 | bp->b_offset = offset; |
d1afb678 LM |
803 | |
804 | for (i = 0; i < bp->b_page_count; i++) { | |
805 | bp->b_pages[i] = mem_to_page((void *)pageaddr); | |
0e6e847f | 806 | pageaddr += PAGE_SIZE; |
1da177e4 | 807 | } |
1da177e4 | 808 | |
aa0e8833 | 809 | bp->b_io_length = BTOBB(len); |
4e94b71b | 810 | bp->b_length = BTOBB(buflen); |
1da177e4 LT |
811 | |
812 | return 0; | |
813 | } | |
814 | ||
815 | xfs_buf_t * | |
686865f7 DC |
816 | xfs_buf_get_uncached( |
817 | struct xfs_buftarg *target, | |
e70b73f8 | 818 | size_t numblks, |
686865f7 | 819 | int flags) |
1da177e4 | 820 | { |
e70b73f8 | 821 | unsigned long page_count; |
1fa40b01 | 822 | int error, i; |
3e85c868 DC |
823 | struct xfs_buf *bp; |
824 | DEFINE_SINGLE_BUF_MAP(map, XFS_BUF_DADDR_NULL, numblks); | |
1da177e4 | 825 | |
3e85c868 | 826 | bp = _xfs_buf_alloc(target, &map, 1, 0); |
1da177e4 LT |
827 | if (unlikely(bp == NULL)) |
828 | goto fail; | |
1da177e4 | 829 | |
e70b73f8 | 830 | page_count = PAGE_ALIGN(numblks << BBSHIFT) >> PAGE_SHIFT; |
1fa40b01 CH |
831 | error = _xfs_buf_get_pages(bp, page_count, 0); |
832 | if (error) | |
1da177e4 LT |
833 | goto fail_free_buf; |
834 | ||
1fa40b01 | 835 | for (i = 0; i < page_count; i++) { |
686865f7 | 836 | bp->b_pages[i] = alloc_page(xb_to_gfp(flags)); |
1fa40b01 CH |
837 | if (!bp->b_pages[i]) |
838 | goto fail_free_mem; | |
1da177e4 | 839 | } |
1fa40b01 | 840 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 841 | |
611c9946 | 842 | error = _xfs_buf_map_pages(bp, 0); |
1fa40b01 | 843 | if (unlikely(error)) { |
4f10700a DC |
844 | xfs_warn(target->bt_mount, |
845 | "%s: failed to map pages\n", __func__); | |
1da177e4 | 846 | goto fail_free_mem; |
1fa40b01 | 847 | } |
1da177e4 | 848 | |
686865f7 | 849 | trace_xfs_buf_get_uncached(bp, _RET_IP_); |
1da177e4 | 850 | return bp; |
1fa40b01 | 851 | |
1da177e4 | 852 | fail_free_mem: |
1fa40b01 CH |
853 | while (--i >= 0) |
854 | __free_page(bp->b_pages[i]); | |
ca165b88 | 855 | _xfs_buf_free_pages(bp); |
1da177e4 | 856 | fail_free_buf: |
3e85c868 | 857 | xfs_buf_free_maps(bp); |
4347b9d7 | 858 | kmem_zone_free(xfs_buf_zone, bp); |
1da177e4 LT |
859 | fail: |
860 | return NULL; | |
861 | } | |
862 | ||
863 | /* | |
1da177e4 LT |
864 | * Increment reference count on buffer, to hold the buffer concurrently |
865 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
866 | * Must hold the buffer already to call this function. |
867 | */ | |
868 | void | |
ce8e922c NS |
869 | xfs_buf_hold( |
870 | xfs_buf_t *bp) | |
1da177e4 | 871 | { |
0b1b213f | 872 | trace_xfs_buf_hold(bp, _RET_IP_); |
ce8e922c | 873 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
874 | } |
875 | ||
876 | /* | |
ce8e922c NS |
877 | * Releases a hold on the specified buffer. If the |
878 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
879 | */ |
880 | void | |
ce8e922c NS |
881 | xfs_buf_rele( |
882 | xfs_buf_t *bp) | |
1da177e4 | 883 | { |
74f75a0c | 884 | struct xfs_perag *pag = bp->b_pag; |
1da177e4 | 885 | |
0b1b213f | 886 | trace_xfs_buf_rele(bp, _RET_IP_); |
1da177e4 | 887 | |
74f75a0c | 888 | if (!pag) { |
430cbeb8 | 889 | ASSERT(list_empty(&bp->b_lru)); |
74f75a0c | 890 | ASSERT(RB_EMPTY_NODE(&bp->b_rbnode)); |
fad3aa1e NS |
891 | if (atomic_dec_and_test(&bp->b_hold)) |
892 | xfs_buf_free(bp); | |
893 | return; | |
894 | } | |
895 | ||
74f75a0c | 896 | ASSERT(!RB_EMPTY_NODE(&bp->b_rbnode)); |
430cbeb8 | 897 | |
3790689f | 898 | ASSERT(atomic_read(&bp->b_hold) > 0); |
74f75a0c | 899 | if (atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock)) { |
bfc60177 | 900 | if (!(bp->b_flags & XBF_STALE) && |
430cbeb8 DC |
901 | atomic_read(&bp->b_lru_ref)) { |
902 | xfs_buf_lru_add(bp); | |
903 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 904 | } else { |
430cbeb8 | 905 | xfs_buf_lru_del(bp); |
43ff2122 | 906 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); |
74f75a0c DC |
907 | rb_erase(&bp->b_rbnode, &pag->pag_buf_tree); |
908 | spin_unlock(&pag->pag_buf_lock); | |
909 | xfs_perag_put(pag); | |
ce8e922c | 910 | xfs_buf_free(bp); |
1da177e4 LT |
911 | } |
912 | } | |
913 | } | |
914 | ||
915 | ||
916 | /* | |
0e6e847f | 917 | * Lock a buffer object, if it is not already locked. |
90810b9e DC |
918 | * |
919 | * If we come across a stale, pinned, locked buffer, we know that we are | |
920 | * being asked to lock a buffer that has been reallocated. Because it is | |
921 | * pinned, we know that the log has not been pushed to disk and hence it | |
922 | * will still be locked. Rather than continuing to have trylock attempts | |
923 | * fail until someone else pushes the log, push it ourselves before | |
924 | * returning. This means that the xfsaild will not get stuck trying | |
925 | * to push on stale inode buffers. | |
1da177e4 LT |
926 | */ |
927 | int | |
0c842ad4 CH |
928 | xfs_buf_trylock( |
929 | struct xfs_buf *bp) | |
1da177e4 LT |
930 | { |
931 | int locked; | |
932 | ||
ce8e922c | 933 | locked = down_trylock(&bp->b_sema) == 0; |
0b1b213f | 934 | if (locked) |
ce8e922c | 935 | XB_SET_OWNER(bp); |
90810b9e DC |
936 | else if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
937 | xfs_log_force(bp->b_target->bt_mount, 0); | |
0b1b213f | 938 | |
0c842ad4 CH |
939 | trace_xfs_buf_trylock(bp, _RET_IP_); |
940 | return locked; | |
1da177e4 | 941 | } |
1da177e4 LT |
942 | |
943 | /* | |
0e6e847f | 944 | * Lock a buffer object. |
ed3b4d6c DC |
945 | * |
946 | * If we come across a stale, pinned, locked buffer, we know that we | |
947 | * are being asked to lock a buffer that has been reallocated. Because | |
948 | * it is pinned, we know that the log has not been pushed to disk and | |
949 | * hence it will still be locked. Rather than sleeping until someone | |
950 | * else pushes the log, push it ourselves before trying to get the lock. | |
1da177e4 | 951 | */ |
ce8e922c NS |
952 | void |
953 | xfs_buf_lock( | |
0c842ad4 | 954 | struct xfs_buf *bp) |
1da177e4 | 955 | { |
0b1b213f CH |
956 | trace_xfs_buf_lock(bp, _RET_IP_); |
957 | ||
ed3b4d6c | 958 | if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
ebad861b | 959 | xfs_log_force(bp->b_target->bt_mount, 0); |
ce8e922c NS |
960 | down(&bp->b_sema); |
961 | XB_SET_OWNER(bp); | |
0b1b213f CH |
962 | |
963 | trace_xfs_buf_lock_done(bp, _RET_IP_); | |
1da177e4 LT |
964 | } |
965 | ||
1da177e4 | 966 | void |
ce8e922c | 967 | xfs_buf_unlock( |
0c842ad4 | 968 | struct xfs_buf *bp) |
1da177e4 | 969 | { |
ce8e922c NS |
970 | XB_CLEAR_OWNER(bp); |
971 | up(&bp->b_sema); | |
0b1b213f CH |
972 | |
973 | trace_xfs_buf_unlock(bp, _RET_IP_); | |
1da177e4 LT |
974 | } |
975 | ||
ce8e922c NS |
976 | STATIC void |
977 | xfs_buf_wait_unpin( | |
978 | xfs_buf_t *bp) | |
1da177e4 LT |
979 | { |
980 | DECLARE_WAITQUEUE (wait, current); | |
981 | ||
ce8e922c | 982 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
983 | return; |
984 | ||
ce8e922c | 985 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
986 | for (;;) { |
987 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 988 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 989 | break; |
7eaceacc | 990 | io_schedule(); |
1da177e4 | 991 | } |
ce8e922c | 992 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
993 | set_current_state(TASK_RUNNING); |
994 | } | |
995 | ||
996 | /* | |
997 | * Buffer Utility Routines | |
998 | */ | |
999 | ||
1da177e4 | 1000 | STATIC void |
ce8e922c | 1001 | xfs_buf_iodone_work( |
c4028958 | 1002 | struct work_struct *work) |
1da177e4 | 1003 | { |
1813dd64 | 1004 | struct xfs_buf *bp = |
c4028958 | 1005 | container_of(work, xfs_buf_t, b_iodone_work); |
1813dd64 DC |
1006 | bool read = !!(bp->b_flags & XBF_READ); |
1007 | ||
1008 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); | |
1009 | if (read && bp->b_ops) | |
1010 | bp->b_ops->verify_read(bp); | |
1da177e4 | 1011 | |
80f6c29d | 1012 | if (bp->b_iodone) |
ce8e922c NS |
1013 | (*(bp->b_iodone))(bp); |
1014 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 | 1015 | xfs_buf_relse(bp); |
1813dd64 DC |
1016 | else { |
1017 | ASSERT(read && bp->b_ops); | |
1018 | complete(&bp->b_iowait); | |
1019 | } | |
1da177e4 LT |
1020 | } |
1021 | ||
1022 | void | |
ce8e922c | 1023 | xfs_buf_ioend( |
1813dd64 DC |
1024 | struct xfs_buf *bp, |
1025 | int schedule) | |
1da177e4 | 1026 | { |
1813dd64 DC |
1027 | bool read = !!(bp->b_flags & XBF_READ); |
1028 | ||
0b1b213f CH |
1029 | trace_xfs_buf_iodone(bp, _RET_IP_); |
1030 | ||
ce8e922c NS |
1031 | if (bp->b_error == 0) |
1032 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1033 | |
1813dd64 | 1034 | if (bp->b_iodone || (read && bp->b_ops) || (bp->b_flags & XBF_ASYNC)) { |
1da177e4 | 1035 | if (schedule) { |
c4028958 | 1036 | INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work); |
ce8e922c | 1037 | queue_work(xfslogd_workqueue, &bp->b_iodone_work); |
1da177e4 | 1038 | } else { |
c4028958 | 1039 | xfs_buf_iodone_work(&bp->b_iodone_work); |
1da177e4 LT |
1040 | } |
1041 | } else { | |
1813dd64 | 1042 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); |
b4dd330b | 1043 | complete(&bp->b_iowait); |
1da177e4 LT |
1044 | } |
1045 | } | |
1046 | ||
1da177e4 | 1047 | void |
ce8e922c NS |
1048 | xfs_buf_ioerror( |
1049 | xfs_buf_t *bp, | |
1050 | int error) | |
1da177e4 LT |
1051 | { |
1052 | ASSERT(error >= 0 && error <= 0xffff); | |
ce8e922c | 1053 | bp->b_error = (unsigned short)error; |
0b1b213f | 1054 | trace_xfs_buf_ioerror(bp, error, _RET_IP_); |
1da177e4 LT |
1055 | } |
1056 | ||
901796af CH |
1057 | void |
1058 | xfs_buf_ioerror_alert( | |
1059 | struct xfs_buf *bp, | |
1060 | const char *func) | |
1061 | { | |
1062 | xfs_alert(bp->b_target->bt_mount, | |
aa0e8833 DC |
1063 | "metadata I/O error: block 0x%llx (\"%s\") error %d numblks %d", |
1064 | (__uint64_t)XFS_BUF_ADDR(bp), func, bp->b_error, bp->b_length); | |
901796af CH |
1065 | } |
1066 | ||
4e23471a CH |
1067 | /* |
1068 | * Called when we want to stop a buffer from getting written or read. | |
1a1a3e97 | 1069 | * We attach the EIO error, muck with its flags, and call xfs_buf_ioend |
4e23471a CH |
1070 | * so that the proper iodone callbacks get called. |
1071 | */ | |
1072 | STATIC int | |
1073 | xfs_bioerror( | |
1074 | xfs_buf_t *bp) | |
1075 | { | |
1076 | #ifdef XFSERRORDEBUG | |
1077 | ASSERT(XFS_BUF_ISREAD(bp) || bp->b_iodone); | |
1078 | #endif | |
1079 | ||
1080 | /* | |
1081 | * No need to wait until the buffer is unpinned, we aren't flushing it. | |
1082 | */ | |
5a52c2a5 | 1083 | xfs_buf_ioerror(bp, EIO); |
4e23471a CH |
1084 | |
1085 | /* | |
1a1a3e97 | 1086 | * We're calling xfs_buf_ioend, so delete XBF_DONE flag. |
4e23471a CH |
1087 | */ |
1088 | XFS_BUF_UNREAD(bp); | |
4e23471a | 1089 | XFS_BUF_UNDONE(bp); |
c867cb61 | 1090 | xfs_buf_stale(bp); |
4e23471a | 1091 | |
1a1a3e97 | 1092 | xfs_buf_ioend(bp, 0); |
4e23471a CH |
1093 | |
1094 | return EIO; | |
1095 | } | |
1096 | ||
1097 | /* | |
1098 | * Same as xfs_bioerror, except that we are releasing the buffer | |
1a1a3e97 | 1099 | * here ourselves, and avoiding the xfs_buf_ioend call. |
4e23471a CH |
1100 | * This is meant for userdata errors; metadata bufs come with |
1101 | * iodone functions attached, so that we can track down errors. | |
1102 | */ | |
1103 | STATIC int | |
1104 | xfs_bioerror_relse( | |
1105 | struct xfs_buf *bp) | |
1106 | { | |
ed43233b | 1107 | int64_t fl = bp->b_flags; |
4e23471a CH |
1108 | /* |
1109 | * No need to wait until the buffer is unpinned. | |
1110 | * We aren't flushing it. | |
1111 | * | |
1112 | * chunkhold expects B_DONE to be set, whether | |
1113 | * we actually finish the I/O or not. We don't want to | |
1114 | * change that interface. | |
1115 | */ | |
1116 | XFS_BUF_UNREAD(bp); | |
4e23471a | 1117 | XFS_BUF_DONE(bp); |
c867cb61 | 1118 | xfs_buf_stale(bp); |
cb669ca5 | 1119 | bp->b_iodone = NULL; |
0cadda1c | 1120 | if (!(fl & XBF_ASYNC)) { |
4e23471a CH |
1121 | /* |
1122 | * Mark b_error and B_ERROR _both_. | |
1123 | * Lot's of chunkcache code assumes that. | |
1124 | * There's no reason to mark error for | |
1125 | * ASYNC buffers. | |
1126 | */ | |
5a52c2a5 | 1127 | xfs_buf_ioerror(bp, EIO); |
5fde0326 | 1128 | complete(&bp->b_iowait); |
4e23471a CH |
1129 | } else { |
1130 | xfs_buf_relse(bp); | |
1131 | } | |
1132 | ||
1133 | return EIO; | |
1134 | } | |
1135 | ||
a2dcf5df | 1136 | STATIC int |
4e23471a CH |
1137 | xfs_bdstrat_cb( |
1138 | struct xfs_buf *bp) | |
1139 | { | |
ebad861b | 1140 | if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) { |
4e23471a CH |
1141 | trace_xfs_bdstrat_shut(bp, _RET_IP_); |
1142 | /* | |
1143 | * Metadata write that didn't get logged but | |
1144 | * written delayed anyway. These aren't associated | |
1145 | * with a transaction, and can be ignored. | |
1146 | */ | |
1147 | if (!bp->b_iodone && !XFS_BUF_ISREAD(bp)) | |
1148 | return xfs_bioerror_relse(bp); | |
1149 | else | |
1150 | return xfs_bioerror(bp); | |
1151 | } | |
1152 | ||
1153 | xfs_buf_iorequest(bp); | |
1154 | return 0; | |
1155 | } | |
1156 | ||
a2dcf5df CH |
1157 | int |
1158 | xfs_bwrite( | |
1159 | struct xfs_buf *bp) | |
1160 | { | |
1161 | int error; | |
1162 | ||
1163 | ASSERT(xfs_buf_islocked(bp)); | |
1164 | ||
1165 | bp->b_flags |= XBF_WRITE; | |
1166 | bp->b_flags &= ~(XBF_ASYNC | XBF_READ | _XBF_DELWRI_Q); | |
1167 | ||
1168 | xfs_bdstrat_cb(bp); | |
1169 | ||
1170 | error = xfs_buf_iowait(bp); | |
1171 | if (error) { | |
1172 | xfs_force_shutdown(bp->b_target->bt_mount, | |
1173 | SHUTDOWN_META_IO_ERROR); | |
1174 | } | |
1175 | return error; | |
1176 | } | |
1177 | ||
4e23471a CH |
1178 | /* |
1179 | * Wrapper around bdstrat so that we can stop data from going to disk in case | |
1180 | * we are shutting down the filesystem. Typically user data goes thru this | |
1181 | * path; one of the exceptions is the superblock. | |
1182 | */ | |
1183 | void | |
1184 | xfsbdstrat( | |
1185 | struct xfs_mount *mp, | |
1186 | struct xfs_buf *bp) | |
1187 | { | |
1188 | if (XFS_FORCED_SHUTDOWN(mp)) { | |
1189 | trace_xfs_bdstrat_shut(bp, _RET_IP_); | |
1190 | xfs_bioerror_relse(bp); | |
1191 | return; | |
1192 | } | |
1193 | ||
1194 | xfs_buf_iorequest(bp); | |
1195 | } | |
1196 | ||
b8f82a4a | 1197 | STATIC void |
ce8e922c NS |
1198 | _xfs_buf_ioend( |
1199 | xfs_buf_t *bp, | |
1da177e4 LT |
1200 | int schedule) |
1201 | { | |
0e6e847f | 1202 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) |
ce8e922c | 1203 | xfs_buf_ioend(bp, schedule); |
1da177e4 LT |
1204 | } |
1205 | ||
782e3b3b | 1206 | STATIC void |
ce8e922c | 1207 | xfs_buf_bio_end_io( |
1da177e4 | 1208 | struct bio *bio, |
1da177e4 LT |
1209 | int error) |
1210 | { | |
ce8e922c | 1211 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1da177e4 | 1212 | |
37eb17e6 DC |
1213 | /* |
1214 | * don't overwrite existing errors - otherwise we can lose errors on | |
1215 | * buffers that require multiple bios to complete. | |
1216 | */ | |
1217 | if (!bp->b_error) | |
1218 | xfs_buf_ioerror(bp, -error); | |
1da177e4 | 1219 | |
37eb17e6 | 1220 | if (!bp->b_error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ)) |
73c77e2c JB |
1221 | invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp)); |
1222 | ||
ce8e922c | 1223 | _xfs_buf_ioend(bp, 1); |
1da177e4 | 1224 | bio_put(bio); |
1da177e4 LT |
1225 | } |
1226 | ||
3e85c868 DC |
1227 | static void |
1228 | xfs_buf_ioapply_map( | |
1229 | struct xfs_buf *bp, | |
1230 | int map, | |
1231 | int *buf_offset, | |
1232 | int *count, | |
1233 | int rw) | |
1da177e4 | 1234 | { |
3e85c868 DC |
1235 | int page_index; |
1236 | int total_nr_pages = bp->b_page_count; | |
1237 | int nr_pages; | |
1238 | struct bio *bio; | |
1239 | sector_t sector = bp->b_maps[map].bm_bn; | |
1240 | int size; | |
1241 | int offset; | |
1da177e4 | 1242 | |
ce8e922c | 1243 | total_nr_pages = bp->b_page_count; |
1da177e4 | 1244 | |
3e85c868 DC |
1245 | /* skip the pages in the buffer before the start offset */ |
1246 | page_index = 0; | |
1247 | offset = *buf_offset; | |
1248 | while (offset >= PAGE_SIZE) { | |
1249 | page_index++; | |
1250 | offset -= PAGE_SIZE; | |
f538d4da CH |
1251 | } |
1252 | ||
3e85c868 DC |
1253 | /* |
1254 | * Limit the IO size to the length of the current vector, and update the | |
1255 | * remaining IO count for the next time around. | |
1256 | */ | |
1257 | size = min_t(int, BBTOB(bp->b_maps[map].bm_len), *count); | |
1258 | *count -= size; | |
1259 | *buf_offset += size; | |
34951f5c | 1260 | |
1da177e4 | 1261 | next_chunk: |
ce8e922c | 1262 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1263 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1264 | if (nr_pages > total_nr_pages) | |
1265 | nr_pages = total_nr_pages; | |
1266 | ||
1267 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1268 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1269 | bio->bi_sector = sector; |
ce8e922c NS |
1270 | bio->bi_end_io = xfs_buf_bio_end_io; |
1271 | bio->bi_private = bp; | |
1da177e4 | 1272 | |
0e6e847f | 1273 | |
3e85c868 | 1274 | for (; size && nr_pages; nr_pages--, page_index++) { |
0e6e847f | 1275 | int rbytes, nbytes = PAGE_SIZE - offset; |
1da177e4 LT |
1276 | |
1277 | if (nbytes > size) | |
1278 | nbytes = size; | |
1279 | ||
3e85c868 DC |
1280 | rbytes = bio_add_page(bio, bp->b_pages[page_index], nbytes, |
1281 | offset); | |
ce8e922c | 1282 | if (rbytes < nbytes) |
1da177e4 LT |
1283 | break; |
1284 | ||
1285 | offset = 0; | |
aa0e8833 | 1286 | sector += BTOBB(nbytes); |
1da177e4 LT |
1287 | size -= nbytes; |
1288 | total_nr_pages--; | |
1289 | } | |
1290 | ||
1da177e4 | 1291 | if (likely(bio->bi_size)) { |
73c77e2c JB |
1292 | if (xfs_buf_is_vmapped(bp)) { |
1293 | flush_kernel_vmap_range(bp->b_addr, | |
1294 | xfs_buf_vmap_len(bp)); | |
1295 | } | |
1da177e4 LT |
1296 | submit_bio(rw, bio); |
1297 | if (size) | |
1298 | goto next_chunk; | |
1299 | } else { | |
37eb17e6 DC |
1300 | /* |
1301 | * This is guaranteed not to be the last io reference count | |
1302 | * because the caller (xfs_buf_iorequest) holds a count itself. | |
1303 | */ | |
1304 | atomic_dec(&bp->b_io_remaining); | |
ce8e922c | 1305 | xfs_buf_ioerror(bp, EIO); |
ec53d1db | 1306 | bio_put(bio); |
1da177e4 | 1307 | } |
3e85c868 DC |
1308 | |
1309 | } | |
1310 | ||
1311 | STATIC void | |
1312 | _xfs_buf_ioapply( | |
1313 | struct xfs_buf *bp) | |
1314 | { | |
1315 | struct blk_plug plug; | |
1316 | int rw; | |
1317 | int offset; | |
1318 | int size; | |
1319 | int i; | |
1320 | ||
1321 | if (bp->b_flags & XBF_WRITE) { | |
1322 | if (bp->b_flags & XBF_SYNCIO) | |
1323 | rw = WRITE_SYNC; | |
1324 | else | |
1325 | rw = WRITE; | |
1326 | if (bp->b_flags & XBF_FUA) | |
1327 | rw |= REQ_FUA; | |
1328 | if (bp->b_flags & XBF_FLUSH) | |
1329 | rw |= REQ_FLUSH; | |
1813dd64 DC |
1330 | |
1331 | /* | |
1332 | * Run the write verifier callback function if it exists. If | |
1333 | * this function fails it will mark the buffer with an error and | |
1334 | * the IO should not be dispatched. | |
1335 | */ | |
1336 | if (bp->b_ops) { | |
1337 | bp->b_ops->verify_write(bp); | |
1338 | if (bp->b_error) { | |
1339 | xfs_force_shutdown(bp->b_target->bt_mount, | |
1340 | SHUTDOWN_CORRUPT_INCORE); | |
1341 | return; | |
1342 | } | |
1343 | } | |
3e85c868 DC |
1344 | } else if (bp->b_flags & XBF_READ_AHEAD) { |
1345 | rw = READA; | |
1346 | } else { | |
1347 | rw = READ; | |
1348 | } | |
1349 | ||
1350 | /* we only use the buffer cache for meta-data */ | |
1351 | rw |= REQ_META; | |
1352 | ||
1353 | /* | |
1354 | * Walk all the vectors issuing IO on them. Set up the initial offset | |
1355 | * into the buffer and the desired IO size before we start - | |
1356 | * _xfs_buf_ioapply_vec() will modify them appropriately for each | |
1357 | * subsequent call. | |
1358 | */ | |
1359 | offset = bp->b_offset; | |
1360 | size = BBTOB(bp->b_io_length); | |
1361 | blk_start_plug(&plug); | |
1362 | for (i = 0; i < bp->b_map_count; i++) { | |
1363 | xfs_buf_ioapply_map(bp, i, &offset, &size, rw); | |
1364 | if (bp->b_error) | |
1365 | break; | |
1366 | if (size <= 0) | |
1367 | break; /* all done */ | |
1368 | } | |
1369 | blk_finish_plug(&plug); | |
1da177e4 LT |
1370 | } |
1371 | ||
0e95f19a | 1372 | void |
ce8e922c NS |
1373 | xfs_buf_iorequest( |
1374 | xfs_buf_t *bp) | |
1da177e4 | 1375 | { |
0b1b213f | 1376 | trace_xfs_buf_iorequest(bp, _RET_IP_); |
1da177e4 | 1377 | |
43ff2122 | 1378 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); |
1da177e4 | 1379 | |
375ec69d | 1380 | if (bp->b_flags & XBF_WRITE) |
ce8e922c | 1381 | xfs_buf_wait_unpin(bp); |
ce8e922c | 1382 | xfs_buf_hold(bp); |
1da177e4 LT |
1383 | |
1384 | /* Set the count to 1 initially, this will stop an I/O | |
1385 | * completion callout which happens before we have started | |
ce8e922c | 1386 | * all the I/O from calling xfs_buf_ioend too early. |
1da177e4 | 1387 | */ |
ce8e922c NS |
1388 | atomic_set(&bp->b_io_remaining, 1); |
1389 | _xfs_buf_ioapply(bp); | |
08023d6d | 1390 | _xfs_buf_ioend(bp, 1); |
1da177e4 | 1391 | |
ce8e922c | 1392 | xfs_buf_rele(bp); |
1da177e4 LT |
1393 | } |
1394 | ||
1395 | /* | |
0e95f19a DC |
1396 | * Waits for I/O to complete on the buffer supplied. It returns immediately if |
1397 | * no I/O is pending or there is already a pending error on the buffer. It | |
1398 | * returns the I/O error code, if any, or 0 if there was no error. | |
1da177e4 LT |
1399 | */ |
1400 | int | |
ce8e922c NS |
1401 | xfs_buf_iowait( |
1402 | xfs_buf_t *bp) | |
1da177e4 | 1403 | { |
0b1b213f CH |
1404 | trace_xfs_buf_iowait(bp, _RET_IP_); |
1405 | ||
0e95f19a DC |
1406 | if (!bp->b_error) |
1407 | wait_for_completion(&bp->b_iowait); | |
0b1b213f CH |
1408 | |
1409 | trace_xfs_buf_iowait_done(bp, _RET_IP_); | |
ce8e922c | 1410 | return bp->b_error; |
1da177e4 LT |
1411 | } |
1412 | ||
ce8e922c NS |
1413 | xfs_caddr_t |
1414 | xfs_buf_offset( | |
1415 | xfs_buf_t *bp, | |
1da177e4 LT |
1416 | size_t offset) |
1417 | { | |
1418 | struct page *page; | |
1419 | ||
611c9946 | 1420 | if (bp->b_addr) |
62926044 | 1421 | return bp->b_addr + offset; |
1da177e4 | 1422 | |
ce8e922c | 1423 | offset += bp->b_offset; |
0e6e847f DC |
1424 | page = bp->b_pages[offset >> PAGE_SHIFT]; |
1425 | return (xfs_caddr_t)page_address(page) + (offset & (PAGE_SIZE-1)); | |
1da177e4 LT |
1426 | } |
1427 | ||
1428 | /* | |
1da177e4 LT |
1429 | * Move data into or out of a buffer. |
1430 | */ | |
1431 | void | |
ce8e922c NS |
1432 | xfs_buf_iomove( |
1433 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1434 | size_t boff, /* starting buffer offset */ |
1435 | size_t bsize, /* length to copy */ | |
b9c48649 | 1436 | void *data, /* data address */ |
ce8e922c | 1437 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 | 1438 | { |
795cac72 | 1439 | size_t bend; |
1da177e4 LT |
1440 | |
1441 | bend = boff + bsize; | |
1442 | while (boff < bend) { | |
795cac72 DC |
1443 | struct page *page; |
1444 | int page_index, page_offset, csize; | |
1445 | ||
1446 | page_index = (boff + bp->b_offset) >> PAGE_SHIFT; | |
1447 | page_offset = (boff + bp->b_offset) & ~PAGE_MASK; | |
1448 | page = bp->b_pages[page_index]; | |
1449 | csize = min_t(size_t, PAGE_SIZE - page_offset, | |
1450 | BBTOB(bp->b_io_length) - boff); | |
1da177e4 | 1451 | |
795cac72 | 1452 | ASSERT((csize + page_offset) <= PAGE_SIZE); |
1da177e4 LT |
1453 | |
1454 | switch (mode) { | |
ce8e922c | 1455 | case XBRW_ZERO: |
795cac72 | 1456 | memset(page_address(page) + page_offset, 0, csize); |
1da177e4 | 1457 | break; |
ce8e922c | 1458 | case XBRW_READ: |
795cac72 | 1459 | memcpy(data, page_address(page) + page_offset, csize); |
1da177e4 | 1460 | break; |
ce8e922c | 1461 | case XBRW_WRITE: |
795cac72 | 1462 | memcpy(page_address(page) + page_offset, data, csize); |
1da177e4 LT |
1463 | } |
1464 | ||
1465 | boff += csize; | |
1466 | data += csize; | |
1467 | } | |
1468 | } | |
1469 | ||
1470 | /* | |
ce8e922c | 1471 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1472 | */ |
1473 | ||
1474 | /* | |
430cbeb8 DC |
1475 | * Wait for any bufs with callbacks that have been submitted but have not yet |
1476 | * returned. These buffers will have an elevated hold count, so wait on those | |
1477 | * while freeing all the buffers only held by the LRU. | |
1da177e4 LT |
1478 | */ |
1479 | void | |
1480 | xfs_wait_buftarg( | |
74f75a0c | 1481 | struct xfs_buftarg *btp) |
1da177e4 | 1482 | { |
430cbeb8 DC |
1483 | struct xfs_buf *bp; |
1484 | ||
1485 | restart: | |
1486 | spin_lock(&btp->bt_lru_lock); | |
1487 | while (!list_empty(&btp->bt_lru)) { | |
1488 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1489 | if (atomic_read(&bp->b_hold) > 1) { | |
1490 | spin_unlock(&btp->bt_lru_lock); | |
26af6552 | 1491 | delay(100); |
430cbeb8 | 1492 | goto restart; |
1da177e4 | 1493 | } |
430cbeb8 | 1494 | /* |
90802ed9 | 1495 | * clear the LRU reference count so the buffer doesn't get |
430cbeb8 DC |
1496 | * ignored in xfs_buf_rele(). |
1497 | */ | |
1498 | atomic_set(&bp->b_lru_ref, 0); | |
1499 | spin_unlock(&btp->bt_lru_lock); | |
1500 | xfs_buf_rele(bp); | |
1501 | spin_lock(&btp->bt_lru_lock); | |
1da177e4 | 1502 | } |
430cbeb8 | 1503 | spin_unlock(&btp->bt_lru_lock); |
1da177e4 LT |
1504 | } |
1505 | ||
ff57ab21 DC |
1506 | int |
1507 | xfs_buftarg_shrink( | |
1508 | struct shrinker *shrink, | |
1495f230 | 1509 | struct shrink_control *sc) |
a6867a68 | 1510 | { |
ff57ab21 DC |
1511 | struct xfs_buftarg *btp = container_of(shrink, |
1512 | struct xfs_buftarg, bt_shrinker); | |
430cbeb8 | 1513 | struct xfs_buf *bp; |
1495f230 | 1514 | int nr_to_scan = sc->nr_to_scan; |
430cbeb8 DC |
1515 | LIST_HEAD(dispose); |
1516 | ||
1517 | if (!nr_to_scan) | |
1518 | return btp->bt_lru_nr; | |
1519 | ||
1520 | spin_lock(&btp->bt_lru_lock); | |
1521 | while (!list_empty(&btp->bt_lru)) { | |
1522 | if (nr_to_scan-- <= 0) | |
1523 | break; | |
1524 | ||
1525 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1526 | ||
1527 | /* | |
1528 | * Decrement the b_lru_ref count unless the value is already | |
1529 | * zero. If the value is already zero, we need to reclaim the | |
1530 | * buffer, otherwise it gets another trip through the LRU. | |
1531 | */ | |
1532 | if (!atomic_add_unless(&bp->b_lru_ref, -1, 0)) { | |
1533 | list_move_tail(&bp->b_lru, &btp->bt_lru); | |
1534 | continue; | |
1535 | } | |
1536 | ||
1537 | /* | |
1538 | * remove the buffer from the LRU now to avoid needing another | |
1539 | * lock round trip inside xfs_buf_rele(). | |
1540 | */ | |
1541 | list_move(&bp->b_lru, &dispose); | |
1542 | btp->bt_lru_nr--; | |
6fb8a90a | 1543 | bp->b_lru_flags |= _XBF_LRU_DISPOSE; |
ff57ab21 | 1544 | } |
430cbeb8 DC |
1545 | spin_unlock(&btp->bt_lru_lock); |
1546 | ||
1547 | while (!list_empty(&dispose)) { | |
1548 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); | |
1549 | list_del_init(&bp->b_lru); | |
1550 | xfs_buf_rele(bp); | |
1551 | } | |
1552 | ||
1553 | return btp->bt_lru_nr; | |
a6867a68 DC |
1554 | } |
1555 | ||
1da177e4 LT |
1556 | void |
1557 | xfs_free_buftarg( | |
b7963133 CH |
1558 | struct xfs_mount *mp, |
1559 | struct xfs_buftarg *btp) | |
1da177e4 | 1560 | { |
ff57ab21 DC |
1561 | unregister_shrinker(&btp->bt_shrinker); |
1562 | ||
b7963133 CH |
1563 | if (mp->m_flags & XFS_MOUNT_BARRIER) |
1564 | xfs_blkdev_issue_flush(btp); | |
a6867a68 | 1565 | |
f0e2d93c | 1566 | kmem_free(btp); |
1da177e4 LT |
1567 | } |
1568 | ||
1da177e4 LT |
1569 | STATIC int |
1570 | xfs_setsize_buftarg_flags( | |
1571 | xfs_buftarg_t *btp, | |
1572 | unsigned int blocksize, | |
1573 | unsigned int sectorsize, | |
1574 | int verbose) | |
1575 | { | |
ce8e922c NS |
1576 | btp->bt_bsize = blocksize; |
1577 | btp->bt_sshift = ffs(sectorsize) - 1; | |
1578 | btp->bt_smask = sectorsize - 1; | |
1da177e4 | 1579 | |
ce8e922c | 1580 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
02b102df CH |
1581 | char name[BDEVNAME_SIZE]; |
1582 | ||
1583 | bdevname(btp->bt_bdev, name); | |
1584 | ||
4f10700a DC |
1585 | xfs_warn(btp->bt_mount, |
1586 | "Cannot set_blocksize to %u on device %s\n", | |
02b102df | 1587 | sectorsize, name); |
1da177e4 LT |
1588 | return EINVAL; |
1589 | } | |
1590 | ||
1da177e4 LT |
1591 | return 0; |
1592 | } | |
1593 | ||
1594 | /* | |
ce8e922c NS |
1595 | * When allocating the initial buffer target we have not yet |
1596 | * read in the superblock, so don't know what sized sectors | |
1597 | * are being used is at this early stage. Play safe. | |
1598 | */ | |
1da177e4 LT |
1599 | STATIC int |
1600 | xfs_setsize_buftarg_early( | |
1601 | xfs_buftarg_t *btp, | |
1602 | struct block_device *bdev) | |
1603 | { | |
1604 | return xfs_setsize_buftarg_flags(btp, | |
0e6e847f | 1605 | PAGE_SIZE, bdev_logical_block_size(bdev), 0); |
1da177e4 LT |
1606 | } |
1607 | ||
1608 | int | |
1609 | xfs_setsize_buftarg( | |
1610 | xfs_buftarg_t *btp, | |
1611 | unsigned int blocksize, | |
1612 | unsigned int sectorsize) | |
1613 | { | |
1614 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | |
1615 | } | |
1616 | ||
1da177e4 LT |
1617 | xfs_buftarg_t * |
1618 | xfs_alloc_buftarg( | |
ebad861b | 1619 | struct xfs_mount *mp, |
1da177e4 | 1620 | struct block_device *bdev, |
e2a07812 JE |
1621 | int external, |
1622 | const char *fsname) | |
1da177e4 LT |
1623 | { |
1624 | xfs_buftarg_t *btp; | |
1625 | ||
1626 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP); | |
1627 | ||
ebad861b | 1628 | btp->bt_mount = mp; |
ce8e922c NS |
1629 | btp->bt_dev = bdev->bd_dev; |
1630 | btp->bt_bdev = bdev; | |
0e6e847f DC |
1631 | btp->bt_bdi = blk_get_backing_dev_info(bdev); |
1632 | if (!btp->bt_bdi) | |
1633 | goto error; | |
1634 | ||
430cbeb8 DC |
1635 | INIT_LIST_HEAD(&btp->bt_lru); |
1636 | spin_lock_init(&btp->bt_lru_lock); | |
1da177e4 LT |
1637 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1638 | goto error; | |
ff57ab21 DC |
1639 | btp->bt_shrinker.shrink = xfs_buftarg_shrink; |
1640 | btp->bt_shrinker.seeks = DEFAULT_SEEKS; | |
1641 | register_shrinker(&btp->bt_shrinker); | |
1da177e4 LT |
1642 | return btp; |
1643 | ||
1644 | error: | |
f0e2d93c | 1645 | kmem_free(btp); |
1da177e4 LT |
1646 | return NULL; |
1647 | } | |
1648 | ||
1da177e4 | 1649 | /* |
43ff2122 CH |
1650 | * Add a buffer to the delayed write list. |
1651 | * | |
1652 | * This queues a buffer for writeout if it hasn't already been. Note that | |
1653 | * neither this routine nor the buffer list submission functions perform | |
1654 | * any internal synchronization. It is expected that the lists are thread-local | |
1655 | * to the callers. | |
1656 | * | |
1657 | * Returns true if we queued up the buffer, or false if it already had | |
1658 | * been on the buffer list. | |
1da177e4 | 1659 | */ |
43ff2122 | 1660 | bool |
ce8e922c | 1661 | xfs_buf_delwri_queue( |
43ff2122 CH |
1662 | struct xfs_buf *bp, |
1663 | struct list_head *list) | |
1da177e4 | 1664 | { |
43ff2122 | 1665 | ASSERT(xfs_buf_islocked(bp)); |
5a8ee6ba | 1666 | ASSERT(!(bp->b_flags & XBF_READ)); |
1da177e4 | 1667 | |
43ff2122 CH |
1668 | /* |
1669 | * If the buffer is already marked delwri it already is queued up | |
1670 | * by someone else for imediate writeout. Just ignore it in that | |
1671 | * case. | |
1672 | */ | |
1673 | if (bp->b_flags & _XBF_DELWRI_Q) { | |
1674 | trace_xfs_buf_delwri_queued(bp, _RET_IP_); | |
1675 | return false; | |
1da177e4 | 1676 | } |
1da177e4 | 1677 | |
43ff2122 | 1678 | trace_xfs_buf_delwri_queue(bp, _RET_IP_); |
d808f617 DC |
1679 | |
1680 | /* | |
43ff2122 CH |
1681 | * If a buffer gets written out synchronously or marked stale while it |
1682 | * is on a delwri list we lazily remove it. To do this, the other party | |
1683 | * clears the _XBF_DELWRI_Q flag but otherwise leaves the buffer alone. | |
1684 | * It remains referenced and on the list. In a rare corner case it | |
1685 | * might get readded to a delwri list after the synchronous writeout, in | |
1686 | * which case we need just need to re-add the flag here. | |
d808f617 | 1687 | */ |
43ff2122 CH |
1688 | bp->b_flags |= _XBF_DELWRI_Q; |
1689 | if (list_empty(&bp->b_list)) { | |
1690 | atomic_inc(&bp->b_hold); | |
1691 | list_add_tail(&bp->b_list, list); | |
585e6d88 | 1692 | } |
585e6d88 | 1693 | |
43ff2122 | 1694 | return true; |
585e6d88 DC |
1695 | } |
1696 | ||
089716aa DC |
1697 | /* |
1698 | * Compare function is more complex than it needs to be because | |
1699 | * the return value is only 32 bits and we are doing comparisons | |
1700 | * on 64 bit values | |
1701 | */ | |
1702 | static int | |
1703 | xfs_buf_cmp( | |
1704 | void *priv, | |
1705 | struct list_head *a, | |
1706 | struct list_head *b) | |
1707 | { | |
1708 | struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list); | |
1709 | struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); | |
1710 | xfs_daddr_t diff; | |
1711 | ||
f4b42421 | 1712 | diff = ap->b_maps[0].bm_bn - bp->b_maps[0].bm_bn; |
089716aa DC |
1713 | if (diff < 0) |
1714 | return -1; | |
1715 | if (diff > 0) | |
1716 | return 1; | |
1717 | return 0; | |
1718 | } | |
1719 | ||
43ff2122 CH |
1720 | static int |
1721 | __xfs_buf_delwri_submit( | |
1722 | struct list_head *buffer_list, | |
1723 | struct list_head *io_list, | |
1724 | bool wait) | |
1da177e4 | 1725 | { |
43ff2122 CH |
1726 | struct blk_plug plug; |
1727 | struct xfs_buf *bp, *n; | |
1728 | int pinned = 0; | |
1729 | ||
1730 | list_for_each_entry_safe(bp, n, buffer_list, b_list) { | |
1731 | if (!wait) { | |
1732 | if (xfs_buf_ispinned(bp)) { | |
1733 | pinned++; | |
1734 | continue; | |
1735 | } | |
1736 | if (!xfs_buf_trylock(bp)) | |
1737 | continue; | |
1738 | } else { | |
1739 | xfs_buf_lock(bp); | |
1740 | } | |
978c7b2f | 1741 | |
43ff2122 CH |
1742 | /* |
1743 | * Someone else might have written the buffer synchronously or | |
1744 | * marked it stale in the meantime. In that case only the | |
1745 | * _XBF_DELWRI_Q flag got cleared, and we have to drop the | |
1746 | * reference and remove it from the list here. | |
1747 | */ | |
1748 | if (!(bp->b_flags & _XBF_DELWRI_Q)) { | |
1749 | list_del_init(&bp->b_list); | |
1750 | xfs_buf_relse(bp); | |
1751 | continue; | |
1752 | } | |
c9c12971 | 1753 | |
43ff2122 CH |
1754 | list_move_tail(&bp->b_list, io_list); |
1755 | trace_xfs_buf_delwri_split(bp, _RET_IP_); | |
1756 | } | |
1da177e4 | 1757 | |
43ff2122 | 1758 | list_sort(NULL, io_list, xfs_buf_cmp); |
1da177e4 | 1759 | |
43ff2122 CH |
1760 | blk_start_plug(&plug); |
1761 | list_for_each_entry_safe(bp, n, io_list, b_list) { | |
1762 | bp->b_flags &= ~(_XBF_DELWRI_Q | XBF_ASYNC); | |
1763 | bp->b_flags |= XBF_WRITE; | |
a1b7ea5d | 1764 | |
43ff2122 CH |
1765 | if (!wait) { |
1766 | bp->b_flags |= XBF_ASYNC; | |
ce8e922c | 1767 | list_del_init(&bp->b_list); |
1da177e4 | 1768 | } |
43ff2122 CH |
1769 | xfs_bdstrat_cb(bp); |
1770 | } | |
1771 | blk_finish_plug(&plug); | |
1da177e4 | 1772 | |
43ff2122 | 1773 | return pinned; |
1da177e4 LT |
1774 | } |
1775 | ||
1776 | /* | |
43ff2122 CH |
1777 | * Write out a buffer list asynchronously. |
1778 | * | |
1779 | * This will take the @buffer_list, write all non-locked and non-pinned buffers | |
1780 | * out and not wait for I/O completion on any of the buffers. This interface | |
1781 | * is only safely useable for callers that can track I/O completion by higher | |
1782 | * level means, e.g. AIL pushing as the @buffer_list is consumed in this | |
1783 | * function. | |
1da177e4 LT |
1784 | */ |
1785 | int | |
43ff2122 CH |
1786 | xfs_buf_delwri_submit_nowait( |
1787 | struct list_head *buffer_list) | |
1da177e4 | 1788 | { |
43ff2122 CH |
1789 | LIST_HEAD (io_list); |
1790 | return __xfs_buf_delwri_submit(buffer_list, &io_list, false); | |
1791 | } | |
1da177e4 | 1792 | |
43ff2122 CH |
1793 | /* |
1794 | * Write out a buffer list synchronously. | |
1795 | * | |
1796 | * This will take the @buffer_list, write all buffers out and wait for I/O | |
1797 | * completion on all of the buffers. @buffer_list is consumed by the function, | |
1798 | * so callers must have some other way of tracking buffers if they require such | |
1799 | * functionality. | |
1800 | */ | |
1801 | int | |
1802 | xfs_buf_delwri_submit( | |
1803 | struct list_head *buffer_list) | |
1804 | { | |
1805 | LIST_HEAD (io_list); | |
1806 | int error = 0, error2; | |
1807 | struct xfs_buf *bp; | |
1da177e4 | 1808 | |
43ff2122 | 1809 | __xfs_buf_delwri_submit(buffer_list, &io_list, true); |
1da177e4 | 1810 | |
43ff2122 CH |
1811 | /* Wait for IO to complete. */ |
1812 | while (!list_empty(&io_list)) { | |
1813 | bp = list_first_entry(&io_list, struct xfs_buf, b_list); | |
a1b7ea5d | 1814 | |
089716aa | 1815 | list_del_init(&bp->b_list); |
43ff2122 CH |
1816 | error2 = xfs_buf_iowait(bp); |
1817 | xfs_buf_relse(bp); | |
1818 | if (!error) | |
1819 | error = error2; | |
1da177e4 LT |
1820 | } |
1821 | ||
43ff2122 | 1822 | return error; |
1da177e4 LT |
1823 | } |
1824 | ||
04d8b284 | 1825 | int __init |
ce8e922c | 1826 | xfs_buf_init(void) |
1da177e4 | 1827 | { |
8758280f NS |
1828 | xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf", |
1829 | KM_ZONE_HWALIGN, NULL); | |
ce8e922c | 1830 | if (!xfs_buf_zone) |
0b1b213f | 1831 | goto out; |
04d8b284 | 1832 | |
51749e47 | 1833 | xfslogd_workqueue = alloc_workqueue("xfslogd", |
6370a6ad | 1834 | WQ_MEM_RECLAIM | WQ_HIGHPRI, 1); |
23ea4032 | 1835 | if (!xfslogd_workqueue) |
04d8b284 | 1836 | goto out_free_buf_zone; |
1da177e4 | 1837 | |
23ea4032 | 1838 | return 0; |
1da177e4 | 1839 | |
23ea4032 | 1840 | out_free_buf_zone: |
ce8e922c | 1841 | kmem_zone_destroy(xfs_buf_zone); |
0b1b213f | 1842 | out: |
8758280f | 1843 | return -ENOMEM; |
1da177e4 LT |
1844 | } |
1845 | ||
1da177e4 | 1846 | void |
ce8e922c | 1847 | xfs_buf_terminate(void) |
1da177e4 | 1848 | { |
04d8b284 | 1849 | destroy_workqueue(xfslogd_workqueue); |
ce8e922c | 1850 | kmem_zone_destroy(xfs_buf_zone); |
1da177e4 | 1851 | } |