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" |
7fd36c44 | 38 | #include "xfs_trans_resv.h" |
ed3b4d6c | 39 | #include "xfs_log.h" |
b7963133 | 40 | #include "xfs_ag.h" |
b7963133 | 41 | #include "xfs_mount.h" |
0b1b213f | 42 | #include "xfs_trace.h" |
b7963133 | 43 | |
7989cb8e | 44 | static kmem_zone_t *xfs_buf_zone; |
23ea4032 | 45 | |
7989cb8e | 46 | static struct workqueue_struct *xfslogd_workqueue; |
1da177e4 | 47 | |
ce8e922c NS |
48 | #ifdef XFS_BUF_LOCK_TRACKING |
49 | # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid) | |
50 | # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1) | |
51 | # define XB_GET_OWNER(bp) ((bp)->b_last_holder) | |
1da177e4 | 52 | #else |
ce8e922c NS |
53 | # define XB_SET_OWNER(bp) do { } while (0) |
54 | # define XB_CLEAR_OWNER(bp) do { } while (0) | |
55 | # define XB_GET_OWNER(bp) do { } while (0) | |
1da177e4 LT |
56 | #endif |
57 | ||
ce8e922c | 58 | #define xb_to_gfp(flags) \ |
aa5c158e | 59 | ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : GFP_NOFS) | __GFP_NOWARN) |
1da177e4 | 60 | |
1da177e4 | 61 | |
73c77e2c JB |
62 | static inline int |
63 | xfs_buf_is_vmapped( | |
64 | struct xfs_buf *bp) | |
65 | { | |
66 | /* | |
67 | * Return true if the buffer is vmapped. | |
68 | * | |
611c9946 DC |
69 | * b_addr is null if the buffer is not mapped, but the code is clever |
70 | * enough to know it doesn't have to map a single page, so the check has | |
71 | * to be both for b_addr and bp->b_page_count > 1. | |
73c77e2c | 72 | */ |
611c9946 | 73 | return bp->b_addr && bp->b_page_count > 1; |
73c77e2c JB |
74 | } |
75 | ||
76 | static inline int | |
77 | xfs_buf_vmap_len( | |
78 | struct xfs_buf *bp) | |
79 | { | |
80 | return (bp->b_page_count * PAGE_SIZE) - bp->b_offset; | |
81 | } | |
82 | ||
1da177e4 | 83 | /* |
430cbeb8 DC |
84 | * xfs_buf_lru_add - add a buffer to the LRU. |
85 | * | |
86 | * The LRU takes a new reference to the buffer so that it will only be freed | |
87 | * once the shrinker takes the buffer off the LRU. | |
88 | */ | |
89 | STATIC void | |
90 | xfs_buf_lru_add( | |
91 | struct xfs_buf *bp) | |
92 | { | |
93 | struct xfs_buftarg *btp = bp->b_target; | |
94 | ||
95 | spin_lock(&btp->bt_lru_lock); | |
96 | if (list_empty(&bp->b_lru)) { | |
97 | atomic_inc(&bp->b_hold); | |
98 | list_add_tail(&bp->b_lru, &btp->bt_lru); | |
99 | btp->bt_lru_nr++; | |
6fb8a90a | 100 | bp->b_lru_flags &= ~_XBF_LRU_DISPOSE; |
430cbeb8 DC |
101 | } |
102 | spin_unlock(&btp->bt_lru_lock); | |
103 | } | |
104 | ||
105 | /* | |
106 | * xfs_buf_lru_del - remove a buffer from the LRU | |
107 | * | |
108 | * The unlocked check is safe here because it only occurs when there are not | |
109 | * b_lru_ref counts left on the inode under the pag->pag_buf_lock. it is there | |
110 | * to optimise the shrinker removing the buffer from the LRU and calling | |
25985edc | 111 | * xfs_buf_free(). i.e. it removes an unnecessary round trip on the |
430cbeb8 | 112 | * bt_lru_lock. |
1da177e4 | 113 | */ |
430cbeb8 DC |
114 | STATIC void |
115 | xfs_buf_lru_del( | |
116 | struct xfs_buf *bp) | |
117 | { | |
118 | struct xfs_buftarg *btp = bp->b_target; | |
119 | ||
120 | if (list_empty(&bp->b_lru)) | |
121 | return; | |
122 | ||
123 | spin_lock(&btp->bt_lru_lock); | |
124 | if (!list_empty(&bp->b_lru)) { | |
125 | list_del_init(&bp->b_lru); | |
126 | btp->bt_lru_nr--; | |
127 | } | |
128 | spin_unlock(&btp->bt_lru_lock); | |
129 | } | |
130 | ||
131 | /* | |
132 | * When we mark a buffer stale, we remove the buffer from the LRU and clear the | |
133 | * b_lru_ref count so that the buffer is freed immediately when the buffer | |
134 | * reference count falls to zero. If the buffer is already on the LRU, we need | |
135 | * to remove the reference that LRU holds on the buffer. | |
136 | * | |
137 | * This prevents build-up of stale buffers on the LRU. | |
138 | */ | |
139 | void | |
140 | xfs_buf_stale( | |
141 | struct xfs_buf *bp) | |
142 | { | |
43ff2122 CH |
143 | ASSERT(xfs_buf_islocked(bp)); |
144 | ||
430cbeb8 | 145 | bp->b_flags |= XBF_STALE; |
43ff2122 CH |
146 | |
147 | /* | |
148 | * Clear the delwri status so that a delwri queue walker will not | |
149 | * flush this buffer to disk now that it is stale. The delwri queue has | |
150 | * a reference to the buffer, so this is safe to do. | |
151 | */ | |
152 | bp->b_flags &= ~_XBF_DELWRI_Q; | |
153 | ||
430cbeb8 DC |
154 | atomic_set(&(bp)->b_lru_ref, 0); |
155 | if (!list_empty(&bp->b_lru)) { | |
156 | struct xfs_buftarg *btp = bp->b_target; | |
157 | ||
158 | spin_lock(&btp->bt_lru_lock); | |
6fb8a90a CM |
159 | if (!list_empty(&bp->b_lru) && |
160 | !(bp->b_lru_flags & _XBF_LRU_DISPOSE)) { | |
430cbeb8 DC |
161 | list_del_init(&bp->b_lru); |
162 | btp->bt_lru_nr--; | |
163 | atomic_dec(&bp->b_hold); | |
164 | } | |
165 | spin_unlock(&btp->bt_lru_lock); | |
166 | } | |
167 | ASSERT(atomic_read(&bp->b_hold) >= 1); | |
168 | } | |
1da177e4 | 169 | |
3e85c868 DC |
170 | static int |
171 | xfs_buf_get_maps( | |
172 | struct xfs_buf *bp, | |
173 | int map_count) | |
174 | { | |
175 | ASSERT(bp->b_maps == NULL); | |
176 | bp->b_map_count = map_count; | |
177 | ||
178 | if (map_count == 1) { | |
f4b42421 | 179 | bp->b_maps = &bp->__b_map; |
3e85c868 DC |
180 | return 0; |
181 | } | |
182 | ||
183 | bp->b_maps = kmem_zalloc(map_count * sizeof(struct xfs_buf_map), | |
184 | KM_NOFS); | |
185 | if (!bp->b_maps) | |
186 | return ENOMEM; | |
187 | return 0; | |
188 | } | |
189 | ||
190 | /* | |
191 | * Frees b_pages if it was allocated. | |
192 | */ | |
193 | static void | |
194 | xfs_buf_free_maps( | |
195 | struct xfs_buf *bp) | |
196 | { | |
f4b42421 | 197 | if (bp->b_maps != &bp->__b_map) { |
3e85c868 DC |
198 | kmem_free(bp->b_maps); |
199 | bp->b_maps = NULL; | |
200 | } | |
201 | } | |
202 | ||
4347b9d7 | 203 | struct xfs_buf * |
3e85c868 | 204 | _xfs_buf_alloc( |
4347b9d7 | 205 | struct xfs_buftarg *target, |
3e85c868 DC |
206 | struct xfs_buf_map *map, |
207 | int nmaps, | |
ce8e922c | 208 | xfs_buf_flags_t flags) |
1da177e4 | 209 | { |
4347b9d7 | 210 | struct xfs_buf *bp; |
3e85c868 DC |
211 | int error; |
212 | int i; | |
4347b9d7 | 213 | |
aa5c158e | 214 | bp = kmem_zone_zalloc(xfs_buf_zone, KM_NOFS); |
4347b9d7 CH |
215 | if (unlikely(!bp)) |
216 | return NULL; | |
217 | ||
1da177e4 | 218 | /* |
12bcb3f7 DC |
219 | * We don't want certain flags to appear in b_flags unless they are |
220 | * specifically set by later operations on the buffer. | |
1da177e4 | 221 | */ |
611c9946 | 222 | flags &= ~(XBF_UNMAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD); |
ce8e922c | 223 | |
ce8e922c | 224 | atomic_set(&bp->b_hold, 1); |
430cbeb8 | 225 | atomic_set(&bp->b_lru_ref, 1); |
b4dd330b | 226 | init_completion(&bp->b_iowait); |
430cbeb8 | 227 | INIT_LIST_HEAD(&bp->b_lru); |
ce8e922c | 228 | INIT_LIST_HEAD(&bp->b_list); |
74f75a0c | 229 | RB_CLEAR_NODE(&bp->b_rbnode); |
a731cd11 | 230 | sema_init(&bp->b_sema, 0); /* held, no waiters */ |
ce8e922c NS |
231 | XB_SET_OWNER(bp); |
232 | bp->b_target = target; | |
3e85c868 | 233 | bp->b_flags = flags; |
de1cbee4 | 234 | |
1da177e4 | 235 | /* |
aa0e8833 DC |
236 | * Set length and io_length to the same value initially. |
237 | * I/O routines should use io_length, which will be the same in | |
1da177e4 LT |
238 | * most cases but may be reset (e.g. XFS recovery). |
239 | */ | |
3e85c868 DC |
240 | error = xfs_buf_get_maps(bp, nmaps); |
241 | if (error) { | |
242 | kmem_zone_free(xfs_buf_zone, bp); | |
243 | return NULL; | |
244 | } | |
245 | ||
246 | bp->b_bn = map[0].bm_bn; | |
247 | bp->b_length = 0; | |
248 | for (i = 0; i < nmaps; i++) { | |
249 | bp->b_maps[i].bm_bn = map[i].bm_bn; | |
250 | bp->b_maps[i].bm_len = map[i].bm_len; | |
251 | bp->b_length += map[i].bm_len; | |
252 | } | |
253 | bp->b_io_length = bp->b_length; | |
254 | ||
ce8e922c NS |
255 | atomic_set(&bp->b_pin_count, 0); |
256 | init_waitqueue_head(&bp->b_waiters); | |
257 | ||
258 | XFS_STATS_INC(xb_create); | |
0b1b213f | 259 | trace_xfs_buf_init(bp, _RET_IP_); |
4347b9d7 CH |
260 | |
261 | return bp; | |
1da177e4 LT |
262 | } |
263 | ||
264 | /* | |
ce8e922c NS |
265 | * Allocate a page array capable of holding a specified number |
266 | * of pages, and point the page buf at it. | |
1da177e4 LT |
267 | */ |
268 | STATIC int | |
ce8e922c NS |
269 | _xfs_buf_get_pages( |
270 | xfs_buf_t *bp, | |
1da177e4 | 271 | int page_count, |
ce8e922c | 272 | xfs_buf_flags_t flags) |
1da177e4 LT |
273 | { |
274 | /* Make sure that we have a page list */ | |
ce8e922c | 275 | if (bp->b_pages == NULL) { |
ce8e922c NS |
276 | bp->b_page_count = page_count; |
277 | if (page_count <= XB_PAGES) { | |
278 | bp->b_pages = bp->b_page_array; | |
1da177e4 | 279 | } else { |
ce8e922c | 280 | bp->b_pages = kmem_alloc(sizeof(struct page *) * |
aa5c158e | 281 | page_count, KM_NOFS); |
ce8e922c | 282 | if (bp->b_pages == NULL) |
1da177e4 LT |
283 | return -ENOMEM; |
284 | } | |
ce8e922c | 285 | memset(bp->b_pages, 0, sizeof(struct page *) * page_count); |
1da177e4 LT |
286 | } |
287 | return 0; | |
288 | } | |
289 | ||
290 | /* | |
ce8e922c | 291 | * Frees b_pages if it was allocated. |
1da177e4 LT |
292 | */ |
293 | STATIC void | |
ce8e922c | 294 | _xfs_buf_free_pages( |
1da177e4 LT |
295 | xfs_buf_t *bp) |
296 | { | |
ce8e922c | 297 | if (bp->b_pages != bp->b_page_array) { |
f0e2d93c | 298 | kmem_free(bp->b_pages); |
3fc98b1a | 299 | bp->b_pages = NULL; |
1da177e4 LT |
300 | } |
301 | } | |
302 | ||
303 | /* | |
304 | * Releases the specified buffer. | |
305 | * | |
306 | * The modification state of any associated pages is left unchanged. | |
b46fe825 | 307 | * The buffer must not be on any hash - use xfs_buf_rele instead for |
1da177e4 LT |
308 | * hashed and refcounted buffers |
309 | */ | |
310 | void | |
ce8e922c | 311 | xfs_buf_free( |
1da177e4 LT |
312 | xfs_buf_t *bp) |
313 | { | |
0b1b213f | 314 | trace_xfs_buf_free(bp, _RET_IP_); |
1da177e4 | 315 | |
430cbeb8 DC |
316 | ASSERT(list_empty(&bp->b_lru)); |
317 | ||
0e6e847f | 318 | if (bp->b_flags & _XBF_PAGES) { |
1da177e4 LT |
319 | uint i; |
320 | ||
73c77e2c | 321 | if (xfs_buf_is_vmapped(bp)) |
8a262e57 AE |
322 | vm_unmap_ram(bp->b_addr - bp->b_offset, |
323 | bp->b_page_count); | |
1da177e4 | 324 | |
948ecdb4 NS |
325 | for (i = 0; i < bp->b_page_count; i++) { |
326 | struct page *page = bp->b_pages[i]; | |
327 | ||
0e6e847f | 328 | __free_page(page); |
948ecdb4 | 329 | } |
0e6e847f DC |
330 | } else if (bp->b_flags & _XBF_KMEM) |
331 | kmem_free(bp->b_addr); | |
3fc98b1a | 332 | _xfs_buf_free_pages(bp); |
3e85c868 | 333 | xfs_buf_free_maps(bp); |
4347b9d7 | 334 | kmem_zone_free(xfs_buf_zone, bp); |
1da177e4 LT |
335 | } |
336 | ||
337 | /* | |
0e6e847f | 338 | * Allocates all the pages for buffer in question and builds it's page list. |
1da177e4 LT |
339 | */ |
340 | STATIC int | |
0e6e847f | 341 | xfs_buf_allocate_memory( |
1da177e4 LT |
342 | xfs_buf_t *bp, |
343 | uint flags) | |
344 | { | |
aa0e8833 | 345 | size_t size; |
1da177e4 | 346 | size_t nbytes, offset; |
ce8e922c | 347 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 | 348 | unsigned short page_count, i; |
795cac72 | 349 | xfs_off_t start, end; |
1da177e4 LT |
350 | int error; |
351 | ||
0e6e847f DC |
352 | /* |
353 | * for buffers that are contained within a single page, just allocate | |
354 | * the memory from the heap - there's no need for the complexity of | |
355 | * page arrays to keep allocation down to order 0. | |
356 | */ | |
795cac72 DC |
357 | size = BBTOB(bp->b_length); |
358 | if (size < PAGE_SIZE) { | |
aa5c158e | 359 | bp->b_addr = kmem_alloc(size, KM_NOFS); |
0e6e847f DC |
360 | if (!bp->b_addr) { |
361 | /* low memory - use alloc_page loop instead */ | |
362 | goto use_alloc_page; | |
363 | } | |
364 | ||
795cac72 | 365 | if (((unsigned long)(bp->b_addr + size - 1) & PAGE_MASK) != |
0e6e847f DC |
366 | ((unsigned long)bp->b_addr & PAGE_MASK)) { |
367 | /* b_addr spans two pages - use alloc_page instead */ | |
368 | kmem_free(bp->b_addr); | |
369 | bp->b_addr = NULL; | |
370 | goto use_alloc_page; | |
371 | } | |
372 | bp->b_offset = offset_in_page(bp->b_addr); | |
373 | bp->b_pages = bp->b_page_array; | |
374 | bp->b_pages[0] = virt_to_page(bp->b_addr); | |
375 | bp->b_page_count = 1; | |
611c9946 | 376 | bp->b_flags |= _XBF_KMEM; |
0e6e847f DC |
377 | return 0; |
378 | } | |
379 | ||
380 | use_alloc_page: | |
f4b42421 MT |
381 | start = BBTOB(bp->b_maps[0].bm_bn) >> PAGE_SHIFT; |
382 | end = (BBTOB(bp->b_maps[0].bm_bn + bp->b_length) + PAGE_SIZE - 1) | |
cbb7baab | 383 | >> PAGE_SHIFT; |
795cac72 | 384 | page_count = end - start; |
ce8e922c | 385 | error = _xfs_buf_get_pages(bp, page_count, flags); |
1da177e4 LT |
386 | if (unlikely(error)) |
387 | return error; | |
1da177e4 | 388 | |
ce8e922c | 389 | offset = bp->b_offset; |
0e6e847f | 390 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 391 | |
ce8e922c | 392 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
393 | struct page *page; |
394 | uint retries = 0; | |
0e6e847f DC |
395 | retry: |
396 | page = alloc_page(gfp_mask); | |
1da177e4 | 397 | if (unlikely(page == NULL)) { |
ce8e922c NS |
398 | if (flags & XBF_READ_AHEAD) { |
399 | bp->b_page_count = i; | |
0e6e847f DC |
400 | error = ENOMEM; |
401 | goto out_free_pages; | |
1da177e4 LT |
402 | } |
403 | ||
404 | /* | |
405 | * This could deadlock. | |
406 | * | |
407 | * But until all the XFS lowlevel code is revamped to | |
408 | * handle buffer allocation failures we can't do much. | |
409 | */ | |
410 | if (!(++retries % 100)) | |
4f10700a DC |
411 | xfs_err(NULL, |
412 | "possible memory allocation deadlock in %s (mode:0x%x)", | |
34a622b2 | 413 | __func__, gfp_mask); |
1da177e4 | 414 | |
ce8e922c | 415 | XFS_STATS_INC(xb_page_retries); |
8aa7e847 | 416 | congestion_wait(BLK_RW_ASYNC, HZ/50); |
1da177e4 LT |
417 | goto retry; |
418 | } | |
419 | ||
ce8e922c | 420 | XFS_STATS_INC(xb_page_found); |
1da177e4 | 421 | |
0e6e847f | 422 | nbytes = min_t(size_t, size, PAGE_SIZE - offset); |
1da177e4 | 423 | size -= nbytes; |
ce8e922c | 424 | bp->b_pages[i] = page; |
1da177e4 LT |
425 | offset = 0; |
426 | } | |
0e6e847f | 427 | return 0; |
1da177e4 | 428 | |
0e6e847f DC |
429 | out_free_pages: |
430 | for (i = 0; i < bp->b_page_count; i++) | |
431 | __free_page(bp->b_pages[i]); | |
1da177e4 LT |
432 | return error; |
433 | } | |
434 | ||
435 | /* | |
25985edc | 436 | * Map buffer into kernel address-space if necessary. |
1da177e4 LT |
437 | */ |
438 | STATIC int | |
ce8e922c | 439 | _xfs_buf_map_pages( |
1da177e4 LT |
440 | xfs_buf_t *bp, |
441 | uint flags) | |
442 | { | |
0e6e847f | 443 | ASSERT(bp->b_flags & _XBF_PAGES); |
ce8e922c | 444 | if (bp->b_page_count == 1) { |
0e6e847f | 445 | /* A single page buffer is always mappable */ |
ce8e922c | 446 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; |
611c9946 DC |
447 | } else if (flags & XBF_UNMAPPED) { |
448 | bp->b_addr = NULL; | |
449 | } else { | |
a19fb380 DC |
450 | int retried = 0; |
451 | ||
452 | do { | |
453 | bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, | |
454 | -1, PAGE_KERNEL); | |
455 | if (bp->b_addr) | |
456 | break; | |
457 | vm_unmap_aliases(); | |
458 | } while (retried++ <= 1); | |
459 | ||
460 | if (!bp->b_addr) | |
1da177e4 | 461 | return -ENOMEM; |
ce8e922c | 462 | bp->b_addr += bp->b_offset; |
1da177e4 LT |
463 | } |
464 | ||
465 | return 0; | |
466 | } | |
467 | ||
468 | /* | |
469 | * Finding and Reading Buffers | |
470 | */ | |
471 | ||
472 | /* | |
ce8e922c | 473 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 | 474 | * a given range of an inode. The buffer is returned |
eabbaf11 | 475 | * locked. No I/O is implied by this call. |
1da177e4 LT |
476 | */ |
477 | xfs_buf_t * | |
ce8e922c | 478 | _xfs_buf_find( |
e70b73f8 | 479 | struct xfs_buftarg *btp, |
3e85c868 DC |
480 | struct xfs_buf_map *map, |
481 | int nmaps, | |
ce8e922c NS |
482 | xfs_buf_flags_t flags, |
483 | xfs_buf_t *new_bp) | |
1da177e4 | 484 | { |
e70b73f8 | 485 | size_t numbytes; |
74f75a0c DC |
486 | struct xfs_perag *pag; |
487 | struct rb_node **rbp; | |
488 | struct rb_node *parent; | |
489 | xfs_buf_t *bp; | |
3e85c868 | 490 | xfs_daddr_t blkno = map[0].bm_bn; |
10616b80 | 491 | xfs_daddr_t eofs; |
3e85c868 DC |
492 | int numblks = 0; |
493 | int i; | |
1da177e4 | 494 | |
3e85c868 DC |
495 | for (i = 0; i < nmaps; i++) |
496 | numblks += map[i].bm_len; | |
e70b73f8 | 497 | numbytes = BBTOB(numblks); |
1da177e4 LT |
498 | |
499 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
e70b73f8 | 500 | ASSERT(!(numbytes < (1 << btp->bt_sshift))); |
de1cbee4 | 501 | ASSERT(!(BBTOB(blkno) & (xfs_off_t)btp->bt_smask)); |
1da177e4 | 502 | |
10616b80 DC |
503 | /* |
504 | * Corrupted block numbers can get through to here, unfortunately, so we | |
505 | * have to check that the buffer falls within the filesystem bounds. | |
506 | */ | |
507 | eofs = XFS_FSB_TO_BB(btp->bt_mount, btp->bt_mount->m_sb.sb_dblocks); | |
508 | if (blkno >= eofs) { | |
509 | /* | |
510 | * XXX (dgc): we should really be returning EFSCORRUPTED here, | |
511 | * but none of the higher level infrastructure supports | |
512 | * returning a specific error on buffer lookup failures. | |
513 | */ | |
514 | xfs_alert(btp->bt_mount, | |
515 | "%s: Block out of range: block 0x%llx, EOFS 0x%llx ", | |
516 | __func__, blkno, eofs); | |
7bc0dc27 | 517 | WARN_ON(1); |
10616b80 DC |
518 | return NULL; |
519 | } | |
520 | ||
74f75a0c DC |
521 | /* get tree root */ |
522 | pag = xfs_perag_get(btp->bt_mount, | |
e70b73f8 | 523 | xfs_daddr_to_agno(btp->bt_mount, blkno)); |
74f75a0c DC |
524 | |
525 | /* walk tree */ | |
526 | spin_lock(&pag->pag_buf_lock); | |
527 | rbp = &pag->pag_buf_tree.rb_node; | |
528 | parent = NULL; | |
529 | bp = NULL; | |
530 | while (*rbp) { | |
531 | parent = *rbp; | |
532 | bp = rb_entry(parent, struct xfs_buf, b_rbnode); | |
533 | ||
de1cbee4 | 534 | if (blkno < bp->b_bn) |
74f75a0c | 535 | rbp = &(*rbp)->rb_left; |
de1cbee4 | 536 | else if (blkno > bp->b_bn) |
74f75a0c DC |
537 | rbp = &(*rbp)->rb_right; |
538 | else { | |
539 | /* | |
de1cbee4 | 540 | * found a block number match. If the range doesn't |
74f75a0c DC |
541 | * match, the only way this is allowed is if the buffer |
542 | * in the cache is stale and the transaction that made | |
543 | * it stale has not yet committed. i.e. we are | |
544 | * reallocating a busy extent. Skip this buffer and | |
545 | * continue searching to the right for an exact match. | |
546 | */ | |
4e94b71b | 547 | if (bp->b_length != numblks) { |
74f75a0c DC |
548 | ASSERT(bp->b_flags & XBF_STALE); |
549 | rbp = &(*rbp)->rb_right; | |
550 | continue; | |
551 | } | |
ce8e922c | 552 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
553 | goto found; |
554 | } | |
555 | } | |
556 | ||
557 | /* No match found */ | |
ce8e922c | 558 | if (new_bp) { |
74f75a0c DC |
559 | rb_link_node(&new_bp->b_rbnode, parent, rbp); |
560 | rb_insert_color(&new_bp->b_rbnode, &pag->pag_buf_tree); | |
561 | /* the buffer keeps the perag reference until it is freed */ | |
562 | new_bp->b_pag = pag; | |
563 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 564 | } else { |
ce8e922c | 565 | XFS_STATS_INC(xb_miss_locked); |
74f75a0c DC |
566 | spin_unlock(&pag->pag_buf_lock); |
567 | xfs_perag_put(pag); | |
1da177e4 | 568 | } |
ce8e922c | 569 | return new_bp; |
1da177e4 LT |
570 | |
571 | found: | |
74f75a0c DC |
572 | spin_unlock(&pag->pag_buf_lock); |
573 | xfs_perag_put(pag); | |
1da177e4 | 574 | |
0c842ad4 CH |
575 | if (!xfs_buf_trylock(bp)) { |
576 | if (flags & XBF_TRYLOCK) { | |
ce8e922c NS |
577 | xfs_buf_rele(bp); |
578 | XFS_STATS_INC(xb_busy_locked); | |
579 | return NULL; | |
1da177e4 | 580 | } |
0c842ad4 CH |
581 | xfs_buf_lock(bp); |
582 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 LT |
583 | } |
584 | ||
0e6e847f DC |
585 | /* |
586 | * if the buffer is stale, clear all the external state associated with | |
587 | * it. We need to keep flags such as how we allocated the buffer memory | |
588 | * intact here. | |
589 | */ | |
ce8e922c NS |
590 | if (bp->b_flags & XBF_STALE) { |
591 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
cfb02852 | 592 | ASSERT(bp->b_iodone == NULL); |
611c9946 | 593 | bp->b_flags &= _XBF_KMEM | _XBF_PAGES; |
1813dd64 | 594 | bp->b_ops = NULL; |
2f926587 | 595 | } |
0b1b213f CH |
596 | |
597 | trace_xfs_buf_find(bp, flags, _RET_IP_); | |
ce8e922c NS |
598 | XFS_STATS_INC(xb_get_locked); |
599 | return bp; | |
1da177e4 LT |
600 | } |
601 | ||
602 | /* | |
3815832a DC |
603 | * Assembles a buffer covering the specified range. The code is optimised for |
604 | * cache hits, as metadata intensive workloads will see 3 orders of magnitude | |
605 | * more hits than misses. | |
1da177e4 | 606 | */ |
3815832a | 607 | struct xfs_buf * |
6dde2707 DC |
608 | xfs_buf_get_map( |
609 | struct xfs_buftarg *target, | |
610 | struct xfs_buf_map *map, | |
611 | int nmaps, | |
ce8e922c | 612 | xfs_buf_flags_t flags) |
1da177e4 | 613 | { |
3815832a DC |
614 | struct xfs_buf *bp; |
615 | struct xfs_buf *new_bp; | |
0e6e847f | 616 | int error = 0; |
1da177e4 | 617 | |
6dde2707 | 618 | bp = _xfs_buf_find(target, map, nmaps, flags, NULL); |
3815832a DC |
619 | if (likely(bp)) |
620 | goto found; | |
621 | ||
6dde2707 | 622 | new_bp = _xfs_buf_alloc(target, map, nmaps, flags); |
ce8e922c | 623 | if (unlikely(!new_bp)) |
1da177e4 LT |
624 | return NULL; |
625 | ||
fe2429b0 DC |
626 | error = xfs_buf_allocate_memory(new_bp, flags); |
627 | if (error) { | |
3e85c868 | 628 | xfs_buf_free(new_bp); |
fe2429b0 DC |
629 | return NULL; |
630 | } | |
631 | ||
6dde2707 | 632 | bp = _xfs_buf_find(target, map, nmaps, flags, new_bp); |
3815832a | 633 | if (!bp) { |
fe2429b0 | 634 | xfs_buf_free(new_bp); |
3815832a DC |
635 | return NULL; |
636 | } | |
637 | ||
fe2429b0 DC |
638 | if (bp != new_bp) |
639 | xfs_buf_free(new_bp); | |
1da177e4 | 640 | |
3815832a | 641 | found: |
611c9946 | 642 | if (!bp->b_addr) { |
ce8e922c | 643 | error = _xfs_buf_map_pages(bp, flags); |
1da177e4 | 644 | if (unlikely(error)) { |
4f10700a DC |
645 | xfs_warn(target->bt_mount, |
646 | "%s: failed to map pages\n", __func__); | |
a8acad70 DC |
647 | xfs_buf_relse(bp); |
648 | return NULL; | |
1da177e4 LT |
649 | } |
650 | } | |
651 | ||
ce8e922c | 652 | XFS_STATS_INC(xb_get); |
0b1b213f | 653 | trace_xfs_buf_get(bp, flags, _RET_IP_); |
ce8e922c | 654 | return bp; |
1da177e4 LT |
655 | } |
656 | ||
5d765b97 CH |
657 | STATIC int |
658 | _xfs_buf_read( | |
659 | xfs_buf_t *bp, | |
660 | xfs_buf_flags_t flags) | |
661 | { | |
43ff2122 | 662 | ASSERT(!(flags & XBF_WRITE)); |
f4b42421 | 663 | ASSERT(bp->b_maps[0].bm_bn != XFS_BUF_DADDR_NULL); |
5d765b97 | 664 | |
43ff2122 | 665 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD); |
1d5ae5df | 666 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD); |
5d765b97 | 667 | |
0e95f19a DC |
668 | xfs_buf_iorequest(bp); |
669 | if (flags & XBF_ASYNC) | |
670 | return 0; | |
ec53d1db | 671 | return xfs_buf_iowait(bp); |
5d765b97 CH |
672 | } |
673 | ||
1da177e4 | 674 | xfs_buf_t * |
6dde2707 DC |
675 | xfs_buf_read_map( |
676 | struct xfs_buftarg *target, | |
677 | struct xfs_buf_map *map, | |
678 | int nmaps, | |
c3f8fc73 | 679 | xfs_buf_flags_t flags, |
1813dd64 | 680 | const struct xfs_buf_ops *ops) |
1da177e4 | 681 | { |
6dde2707 | 682 | struct xfs_buf *bp; |
ce8e922c NS |
683 | |
684 | flags |= XBF_READ; | |
685 | ||
6dde2707 | 686 | bp = xfs_buf_get_map(target, map, nmaps, flags); |
ce8e922c | 687 | if (bp) { |
0b1b213f CH |
688 | trace_xfs_buf_read(bp, flags, _RET_IP_); |
689 | ||
ce8e922c | 690 | if (!XFS_BUF_ISDONE(bp)) { |
ce8e922c | 691 | XFS_STATS_INC(xb_get_read); |
1813dd64 | 692 | bp->b_ops = ops; |
5d765b97 | 693 | _xfs_buf_read(bp, flags); |
ce8e922c | 694 | } else if (flags & XBF_ASYNC) { |
1da177e4 LT |
695 | /* |
696 | * Read ahead call which is already satisfied, | |
697 | * drop the buffer | |
698 | */ | |
a8acad70 DC |
699 | xfs_buf_relse(bp); |
700 | return NULL; | |
1da177e4 | 701 | } else { |
1da177e4 | 702 | /* We do not want read in the flags */ |
ce8e922c | 703 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
704 | } |
705 | } | |
706 | ||
ce8e922c | 707 | return bp; |
1da177e4 LT |
708 | } |
709 | ||
1da177e4 | 710 | /* |
ce8e922c NS |
711 | * If we are not low on memory then do the readahead in a deadlock |
712 | * safe manner. | |
1da177e4 LT |
713 | */ |
714 | void | |
6dde2707 DC |
715 | xfs_buf_readahead_map( |
716 | struct xfs_buftarg *target, | |
717 | struct xfs_buf_map *map, | |
c3f8fc73 | 718 | int nmaps, |
1813dd64 | 719 | const struct xfs_buf_ops *ops) |
1da177e4 | 720 | { |
0e6e847f | 721 | if (bdi_read_congested(target->bt_bdi)) |
1da177e4 LT |
722 | return; |
723 | ||
6dde2707 | 724 | xfs_buf_read_map(target, map, nmaps, |
1813dd64 | 725 | XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD, ops); |
1da177e4 LT |
726 | } |
727 | ||
5adc94c2 DC |
728 | /* |
729 | * Read an uncached buffer from disk. Allocates and returns a locked | |
730 | * buffer containing the disk contents or nothing. | |
731 | */ | |
732 | struct xfs_buf * | |
733 | xfs_buf_read_uncached( | |
5adc94c2 DC |
734 | struct xfs_buftarg *target, |
735 | xfs_daddr_t daddr, | |
e70b73f8 | 736 | size_t numblks, |
c3f8fc73 | 737 | int flags, |
1813dd64 | 738 | const struct xfs_buf_ops *ops) |
5adc94c2 | 739 | { |
eab4e633 | 740 | struct xfs_buf *bp; |
5adc94c2 | 741 | |
e70b73f8 | 742 | bp = xfs_buf_get_uncached(target, numblks, flags); |
5adc94c2 DC |
743 | if (!bp) |
744 | return NULL; | |
745 | ||
746 | /* set up the buffer for a read IO */ | |
3e85c868 DC |
747 | ASSERT(bp->b_map_count == 1); |
748 | bp->b_bn = daddr; | |
749 | bp->b_maps[0].bm_bn = daddr; | |
cbb7baab | 750 | bp->b_flags |= XBF_READ; |
1813dd64 | 751 | bp->b_ops = ops; |
5adc94c2 | 752 | |
e70b73f8 | 753 | xfsbdstrat(target->bt_mount, bp); |
eab4e633 | 754 | xfs_buf_iowait(bp); |
5adc94c2 | 755 | return bp; |
1da177e4 LT |
756 | } |
757 | ||
44396476 DC |
758 | /* |
759 | * Return a buffer allocated as an empty buffer and associated to external | |
760 | * memory via xfs_buf_associate_memory() back to it's empty state. | |
761 | */ | |
762 | void | |
763 | xfs_buf_set_empty( | |
764 | struct xfs_buf *bp, | |
e70b73f8 | 765 | size_t numblks) |
44396476 DC |
766 | { |
767 | if (bp->b_pages) | |
768 | _xfs_buf_free_pages(bp); | |
769 | ||
770 | bp->b_pages = NULL; | |
771 | bp->b_page_count = 0; | |
772 | bp->b_addr = NULL; | |
4e94b71b | 773 | bp->b_length = numblks; |
aa0e8833 | 774 | bp->b_io_length = numblks; |
3e85c868 DC |
775 | |
776 | ASSERT(bp->b_map_count == 1); | |
44396476 | 777 | bp->b_bn = XFS_BUF_DADDR_NULL; |
3e85c868 DC |
778 | bp->b_maps[0].bm_bn = XFS_BUF_DADDR_NULL; |
779 | bp->b_maps[0].bm_len = bp->b_length; | |
44396476 DC |
780 | } |
781 | ||
1da177e4 LT |
782 | static inline struct page * |
783 | mem_to_page( | |
784 | void *addr) | |
785 | { | |
9e2779fa | 786 | if ((!is_vmalloc_addr(addr))) { |
1da177e4 LT |
787 | return virt_to_page(addr); |
788 | } else { | |
789 | return vmalloc_to_page(addr); | |
790 | } | |
791 | } | |
792 | ||
793 | int | |
ce8e922c NS |
794 | xfs_buf_associate_memory( |
795 | xfs_buf_t *bp, | |
1da177e4 LT |
796 | void *mem, |
797 | size_t len) | |
798 | { | |
799 | int rval; | |
800 | int i = 0; | |
d1afb678 LM |
801 | unsigned long pageaddr; |
802 | unsigned long offset; | |
803 | size_t buflen; | |
1da177e4 LT |
804 | int page_count; |
805 | ||
0e6e847f | 806 | pageaddr = (unsigned long)mem & PAGE_MASK; |
d1afb678 | 807 | offset = (unsigned long)mem - pageaddr; |
0e6e847f DC |
808 | buflen = PAGE_ALIGN(len + offset); |
809 | page_count = buflen >> PAGE_SHIFT; | |
1da177e4 LT |
810 | |
811 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
812 | if (bp->b_pages) |
813 | _xfs_buf_free_pages(bp); | |
1da177e4 | 814 | |
ce8e922c NS |
815 | bp->b_pages = NULL; |
816 | bp->b_addr = mem; | |
1da177e4 | 817 | |
aa5c158e | 818 | rval = _xfs_buf_get_pages(bp, page_count, 0); |
1da177e4 LT |
819 | if (rval) |
820 | return rval; | |
821 | ||
ce8e922c | 822 | bp->b_offset = offset; |
d1afb678 LM |
823 | |
824 | for (i = 0; i < bp->b_page_count; i++) { | |
825 | bp->b_pages[i] = mem_to_page((void *)pageaddr); | |
0e6e847f | 826 | pageaddr += PAGE_SIZE; |
1da177e4 | 827 | } |
1da177e4 | 828 | |
aa0e8833 | 829 | bp->b_io_length = BTOBB(len); |
4e94b71b | 830 | bp->b_length = BTOBB(buflen); |
1da177e4 LT |
831 | |
832 | return 0; | |
833 | } | |
834 | ||
835 | xfs_buf_t * | |
686865f7 DC |
836 | xfs_buf_get_uncached( |
837 | struct xfs_buftarg *target, | |
e70b73f8 | 838 | size_t numblks, |
686865f7 | 839 | int flags) |
1da177e4 | 840 | { |
e70b73f8 | 841 | unsigned long page_count; |
1fa40b01 | 842 | int error, i; |
3e85c868 DC |
843 | struct xfs_buf *bp; |
844 | DEFINE_SINGLE_BUF_MAP(map, XFS_BUF_DADDR_NULL, numblks); | |
1da177e4 | 845 | |
3e85c868 | 846 | bp = _xfs_buf_alloc(target, &map, 1, 0); |
1da177e4 LT |
847 | if (unlikely(bp == NULL)) |
848 | goto fail; | |
1da177e4 | 849 | |
e70b73f8 | 850 | page_count = PAGE_ALIGN(numblks << BBSHIFT) >> PAGE_SHIFT; |
1fa40b01 CH |
851 | error = _xfs_buf_get_pages(bp, page_count, 0); |
852 | if (error) | |
1da177e4 LT |
853 | goto fail_free_buf; |
854 | ||
1fa40b01 | 855 | for (i = 0; i < page_count; i++) { |
686865f7 | 856 | bp->b_pages[i] = alloc_page(xb_to_gfp(flags)); |
1fa40b01 CH |
857 | if (!bp->b_pages[i]) |
858 | goto fail_free_mem; | |
1da177e4 | 859 | } |
1fa40b01 | 860 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 861 | |
611c9946 | 862 | error = _xfs_buf_map_pages(bp, 0); |
1fa40b01 | 863 | if (unlikely(error)) { |
4f10700a DC |
864 | xfs_warn(target->bt_mount, |
865 | "%s: failed to map pages\n", __func__); | |
1da177e4 | 866 | goto fail_free_mem; |
1fa40b01 | 867 | } |
1da177e4 | 868 | |
686865f7 | 869 | trace_xfs_buf_get_uncached(bp, _RET_IP_); |
1da177e4 | 870 | return bp; |
1fa40b01 | 871 | |
1da177e4 | 872 | fail_free_mem: |
1fa40b01 CH |
873 | while (--i >= 0) |
874 | __free_page(bp->b_pages[i]); | |
ca165b88 | 875 | _xfs_buf_free_pages(bp); |
1da177e4 | 876 | fail_free_buf: |
3e85c868 | 877 | xfs_buf_free_maps(bp); |
4347b9d7 | 878 | kmem_zone_free(xfs_buf_zone, bp); |
1da177e4 LT |
879 | fail: |
880 | return NULL; | |
881 | } | |
882 | ||
883 | /* | |
1da177e4 LT |
884 | * Increment reference count on buffer, to hold the buffer concurrently |
885 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
886 | * Must hold the buffer already to call this function. |
887 | */ | |
888 | void | |
ce8e922c NS |
889 | xfs_buf_hold( |
890 | xfs_buf_t *bp) | |
1da177e4 | 891 | { |
0b1b213f | 892 | trace_xfs_buf_hold(bp, _RET_IP_); |
ce8e922c | 893 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
894 | } |
895 | ||
896 | /* | |
ce8e922c NS |
897 | * Releases a hold on the specified buffer. If the |
898 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
899 | */ |
900 | void | |
ce8e922c NS |
901 | xfs_buf_rele( |
902 | xfs_buf_t *bp) | |
1da177e4 | 903 | { |
74f75a0c | 904 | struct xfs_perag *pag = bp->b_pag; |
1da177e4 | 905 | |
0b1b213f | 906 | trace_xfs_buf_rele(bp, _RET_IP_); |
1da177e4 | 907 | |
74f75a0c | 908 | if (!pag) { |
430cbeb8 | 909 | ASSERT(list_empty(&bp->b_lru)); |
74f75a0c | 910 | ASSERT(RB_EMPTY_NODE(&bp->b_rbnode)); |
fad3aa1e NS |
911 | if (atomic_dec_and_test(&bp->b_hold)) |
912 | xfs_buf_free(bp); | |
913 | return; | |
914 | } | |
915 | ||
74f75a0c | 916 | ASSERT(!RB_EMPTY_NODE(&bp->b_rbnode)); |
430cbeb8 | 917 | |
3790689f | 918 | ASSERT(atomic_read(&bp->b_hold) > 0); |
74f75a0c | 919 | if (atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock)) { |
bfc60177 | 920 | if (!(bp->b_flags & XBF_STALE) && |
430cbeb8 DC |
921 | atomic_read(&bp->b_lru_ref)) { |
922 | xfs_buf_lru_add(bp); | |
923 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 924 | } else { |
430cbeb8 | 925 | xfs_buf_lru_del(bp); |
43ff2122 | 926 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); |
74f75a0c DC |
927 | rb_erase(&bp->b_rbnode, &pag->pag_buf_tree); |
928 | spin_unlock(&pag->pag_buf_lock); | |
929 | xfs_perag_put(pag); | |
ce8e922c | 930 | xfs_buf_free(bp); |
1da177e4 LT |
931 | } |
932 | } | |
933 | } | |
934 | ||
935 | ||
936 | /* | |
0e6e847f | 937 | * Lock a buffer object, if it is not already locked. |
90810b9e DC |
938 | * |
939 | * If we come across a stale, pinned, locked buffer, we know that we are | |
940 | * being asked to lock a buffer that has been reallocated. Because it is | |
941 | * pinned, we know that the log has not been pushed to disk and hence it | |
942 | * will still be locked. Rather than continuing to have trylock attempts | |
943 | * fail until someone else pushes the log, push it ourselves before | |
944 | * returning. This means that the xfsaild will not get stuck trying | |
945 | * to push on stale inode buffers. | |
1da177e4 LT |
946 | */ |
947 | int | |
0c842ad4 CH |
948 | xfs_buf_trylock( |
949 | struct xfs_buf *bp) | |
1da177e4 LT |
950 | { |
951 | int locked; | |
952 | ||
ce8e922c | 953 | locked = down_trylock(&bp->b_sema) == 0; |
0b1b213f | 954 | if (locked) |
ce8e922c | 955 | XB_SET_OWNER(bp); |
0b1b213f | 956 | |
0c842ad4 CH |
957 | trace_xfs_buf_trylock(bp, _RET_IP_); |
958 | return locked; | |
1da177e4 | 959 | } |
1da177e4 LT |
960 | |
961 | /* | |
0e6e847f | 962 | * Lock a buffer object. |
ed3b4d6c DC |
963 | * |
964 | * If we come across a stale, pinned, locked buffer, we know that we | |
965 | * are being asked to lock a buffer that has been reallocated. Because | |
966 | * it is pinned, we know that the log has not been pushed to disk and | |
967 | * hence it will still be locked. Rather than sleeping until someone | |
968 | * else pushes the log, push it ourselves before trying to get the lock. | |
1da177e4 | 969 | */ |
ce8e922c NS |
970 | void |
971 | xfs_buf_lock( | |
0c842ad4 | 972 | struct xfs_buf *bp) |
1da177e4 | 973 | { |
0b1b213f CH |
974 | trace_xfs_buf_lock(bp, _RET_IP_); |
975 | ||
ed3b4d6c | 976 | if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
ebad861b | 977 | xfs_log_force(bp->b_target->bt_mount, 0); |
ce8e922c NS |
978 | down(&bp->b_sema); |
979 | XB_SET_OWNER(bp); | |
0b1b213f CH |
980 | |
981 | trace_xfs_buf_lock_done(bp, _RET_IP_); | |
1da177e4 LT |
982 | } |
983 | ||
1da177e4 | 984 | void |
ce8e922c | 985 | xfs_buf_unlock( |
0c842ad4 | 986 | struct xfs_buf *bp) |
1da177e4 | 987 | { |
ce8e922c NS |
988 | XB_CLEAR_OWNER(bp); |
989 | up(&bp->b_sema); | |
0b1b213f CH |
990 | |
991 | trace_xfs_buf_unlock(bp, _RET_IP_); | |
1da177e4 LT |
992 | } |
993 | ||
ce8e922c NS |
994 | STATIC void |
995 | xfs_buf_wait_unpin( | |
996 | xfs_buf_t *bp) | |
1da177e4 LT |
997 | { |
998 | DECLARE_WAITQUEUE (wait, current); | |
999 | ||
ce8e922c | 1000 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
1001 | return; |
1002 | ||
ce8e922c | 1003 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1004 | for (;;) { |
1005 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 1006 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 1007 | break; |
7eaceacc | 1008 | io_schedule(); |
1da177e4 | 1009 | } |
ce8e922c | 1010 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1011 | set_current_state(TASK_RUNNING); |
1012 | } | |
1013 | ||
1014 | /* | |
1015 | * Buffer Utility Routines | |
1016 | */ | |
1017 | ||
1da177e4 | 1018 | STATIC void |
ce8e922c | 1019 | xfs_buf_iodone_work( |
c4028958 | 1020 | struct work_struct *work) |
1da177e4 | 1021 | { |
1813dd64 | 1022 | struct xfs_buf *bp = |
c4028958 | 1023 | container_of(work, xfs_buf_t, b_iodone_work); |
1813dd64 DC |
1024 | bool read = !!(bp->b_flags & XBF_READ); |
1025 | ||
1026 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); | |
d5929de8 DC |
1027 | |
1028 | /* only validate buffers that were read without errors */ | |
1029 | if (read && bp->b_ops && !bp->b_error && (bp->b_flags & XBF_DONE)) | |
1813dd64 | 1030 | bp->b_ops->verify_read(bp); |
1da177e4 | 1031 | |
80f6c29d | 1032 | if (bp->b_iodone) |
ce8e922c NS |
1033 | (*(bp->b_iodone))(bp); |
1034 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 | 1035 | xfs_buf_relse(bp); |
1813dd64 DC |
1036 | else { |
1037 | ASSERT(read && bp->b_ops); | |
1038 | complete(&bp->b_iowait); | |
1039 | } | |
1da177e4 LT |
1040 | } |
1041 | ||
1042 | void | |
ce8e922c | 1043 | xfs_buf_ioend( |
1813dd64 DC |
1044 | struct xfs_buf *bp, |
1045 | int schedule) | |
1da177e4 | 1046 | { |
1813dd64 DC |
1047 | bool read = !!(bp->b_flags & XBF_READ); |
1048 | ||
0b1b213f CH |
1049 | trace_xfs_buf_iodone(bp, _RET_IP_); |
1050 | ||
ce8e922c NS |
1051 | if (bp->b_error == 0) |
1052 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1053 | |
1813dd64 | 1054 | if (bp->b_iodone || (read && bp->b_ops) || (bp->b_flags & XBF_ASYNC)) { |
1da177e4 | 1055 | if (schedule) { |
c4028958 | 1056 | INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work); |
ce8e922c | 1057 | queue_work(xfslogd_workqueue, &bp->b_iodone_work); |
1da177e4 | 1058 | } else { |
c4028958 | 1059 | xfs_buf_iodone_work(&bp->b_iodone_work); |
1da177e4 LT |
1060 | } |
1061 | } else { | |
1813dd64 | 1062 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); |
b4dd330b | 1063 | complete(&bp->b_iowait); |
1da177e4 LT |
1064 | } |
1065 | } | |
1066 | ||
1da177e4 | 1067 | void |
ce8e922c NS |
1068 | xfs_buf_ioerror( |
1069 | xfs_buf_t *bp, | |
1070 | int error) | |
1da177e4 LT |
1071 | { |
1072 | ASSERT(error >= 0 && error <= 0xffff); | |
ce8e922c | 1073 | bp->b_error = (unsigned short)error; |
0b1b213f | 1074 | trace_xfs_buf_ioerror(bp, error, _RET_IP_); |
1da177e4 LT |
1075 | } |
1076 | ||
901796af CH |
1077 | void |
1078 | xfs_buf_ioerror_alert( | |
1079 | struct xfs_buf *bp, | |
1080 | const char *func) | |
1081 | { | |
1082 | xfs_alert(bp->b_target->bt_mount, | |
aa0e8833 DC |
1083 | "metadata I/O error: block 0x%llx (\"%s\") error %d numblks %d", |
1084 | (__uint64_t)XFS_BUF_ADDR(bp), func, bp->b_error, bp->b_length); | |
901796af CH |
1085 | } |
1086 | ||
4e23471a CH |
1087 | /* |
1088 | * Called when we want to stop a buffer from getting written or read. | |
1a1a3e97 | 1089 | * We attach the EIO error, muck with its flags, and call xfs_buf_ioend |
4e23471a CH |
1090 | * so that the proper iodone callbacks get called. |
1091 | */ | |
1092 | STATIC int | |
1093 | xfs_bioerror( | |
1094 | xfs_buf_t *bp) | |
1095 | { | |
1096 | #ifdef XFSERRORDEBUG | |
1097 | ASSERT(XFS_BUF_ISREAD(bp) || bp->b_iodone); | |
1098 | #endif | |
1099 | ||
1100 | /* | |
1101 | * No need to wait until the buffer is unpinned, we aren't flushing it. | |
1102 | */ | |
5a52c2a5 | 1103 | xfs_buf_ioerror(bp, EIO); |
4e23471a CH |
1104 | |
1105 | /* | |
1a1a3e97 | 1106 | * We're calling xfs_buf_ioend, so delete XBF_DONE flag. |
4e23471a CH |
1107 | */ |
1108 | XFS_BUF_UNREAD(bp); | |
4e23471a | 1109 | XFS_BUF_UNDONE(bp); |
c867cb61 | 1110 | xfs_buf_stale(bp); |
4e23471a | 1111 | |
1a1a3e97 | 1112 | xfs_buf_ioend(bp, 0); |
4e23471a CH |
1113 | |
1114 | return EIO; | |
1115 | } | |
1116 | ||
1117 | /* | |
1118 | * Same as xfs_bioerror, except that we are releasing the buffer | |
1a1a3e97 | 1119 | * here ourselves, and avoiding the xfs_buf_ioend call. |
4e23471a CH |
1120 | * This is meant for userdata errors; metadata bufs come with |
1121 | * iodone functions attached, so that we can track down errors. | |
1122 | */ | |
1123 | STATIC int | |
1124 | xfs_bioerror_relse( | |
1125 | struct xfs_buf *bp) | |
1126 | { | |
ed43233b | 1127 | int64_t fl = bp->b_flags; |
4e23471a CH |
1128 | /* |
1129 | * No need to wait until the buffer is unpinned. | |
1130 | * We aren't flushing it. | |
1131 | * | |
1132 | * chunkhold expects B_DONE to be set, whether | |
1133 | * we actually finish the I/O or not. We don't want to | |
1134 | * change that interface. | |
1135 | */ | |
1136 | XFS_BUF_UNREAD(bp); | |
4e23471a | 1137 | XFS_BUF_DONE(bp); |
c867cb61 | 1138 | xfs_buf_stale(bp); |
cb669ca5 | 1139 | bp->b_iodone = NULL; |
0cadda1c | 1140 | if (!(fl & XBF_ASYNC)) { |
4e23471a CH |
1141 | /* |
1142 | * Mark b_error and B_ERROR _both_. | |
1143 | * Lot's of chunkcache code assumes that. | |
1144 | * There's no reason to mark error for | |
1145 | * ASYNC buffers. | |
1146 | */ | |
5a52c2a5 | 1147 | xfs_buf_ioerror(bp, EIO); |
5fde0326 | 1148 | complete(&bp->b_iowait); |
4e23471a CH |
1149 | } else { |
1150 | xfs_buf_relse(bp); | |
1151 | } | |
1152 | ||
1153 | return EIO; | |
1154 | } | |
1155 | ||
a2dcf5df | 1156 | STATIC int |
4e23471a CH |
1157 | xfs_bdstrat_cb( |
1158 | struct xfs_buf *bp) | |
1159 | { | |
ebad861b | 1160 | if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) { |
4e23471a CH |
1161 | trace_xfs_bdstrat_shut(bp, _RET_IP_); |
1162 | /* | |
1163 | * Metadata write that didn't get logged but | |
1164 | * written delayed anyway. These aren't associated | |
1165 | * with a transaction, and can be ignored. | |
1166 | */ | |
1167 | if (!bp->b_iodone && !XFS_BUF_ISREAD(bp)) | |
1168 | return xfs_bioerror_relse(bp); | |
1169 | else | |
1170 | return xfs_bioerror(bp); | |
1171 | } | |
1172 | ||
1173 | xfs_buf_iorequest(bp); | |
1174 | return 0; | |
1175 | } | |
1176 | ||
a2dcf5df CH |
1177 | int |
1178 | xfs_bwrite( | |
1179 | struct xfs_buf *bp) | |
1180 | { | |
1181 | int error; | |
1182 | ||
1183 | ASSERT(xfs_buf_islocked(bp)); | |
1184 | ||
1185 | bp->b_flags |= XBF_WRITE; | |
1186 | bp->b_flags &= ~(XBF_ASYNC | XBF_READ | _XBF_DELWRI_Q); | |
1187 | ||
1188 | xfs_bdstrat_cb(bp); | |
1189 | ||
1190 | error = xfs_buf_iowait(bp); | |
1191 | if (error) { | |
1192 | xfs_force_shutdown(bp->b_target->bt_mount, | |
1193 | SHUTDOWN_META_IO_ERROR); | |
1194 | } | |
1195 | return error; | |
1196 | } | |
1197 | ||
4e23471a CH |
1198 | /* |
1199 | * Wrapper around bdstrat so that we can stop data from going to disk in case | |
1200 | * we are shutting down the filesystem. Typically user data goes thru this | |
1201 | * path; one of the exceptions is the superblock. | |
1202 | */ | |
1203 | void | |
1204 | xfsbdstrat( | |
1205 | struct xfs_mount *mp, | |
1206 | struct xfs_buf *bp) | |
1207 | { | |
1208 | if (XFS_FORCED_SHUTDOWN(mp)) { | |
1209 | trace_xfs_bdstrat_shut(bp, _RET_IP_); | |
1210 | xfs_bioerror_relse(bp); | |
1211 | return; | |
1212 | } | |
1213 | ||
1214 | xfs_buf_iorequest(bp); | |
1215 | } | |
1216 | ||
b8f82a4a | 1217 | STATIC void |
ce8e922c NS |
1218 | _xfs_buf_ioend( |
1219 | xfs_buf_t *bp, | |
1da177e4 LT |
1220 | int schedule) |
1221 | { | |
0e6e847f | 1222 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) |
ce8e922c | 1223 | xfs_buf_ioend(bp, schedule); |
1da177e4 LT |
1224 | } |
1225 | ||
782e3b3b | 1226 | STATIC void |
ce8e922c | 1227 | xfs_buf_bio_end_io( |
1da177e4 | 1228 | struct bio *bio, |
1da177e4 LT |
1229 | int error) |
1230 | { | |
ce8e922c | 1231 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1da177e4 | 1232 | |
37eb17e6 DC |
1233 | /* |
1234 | * don't overwrite existing errors - otherwise we can lose errors on | |
1235 | * buffers that require multiple bios to complete. | |
1236 | */ | |
1237 | if (!bp->b_error) | |
1238 | xfs_buf_ioerror(bp, -error); | |
1da177e4 | 1239 | |
37eb17e6 | 1240 | if (!bp->b_error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ)) |
73c77e2c JB |
1241 | invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp)); |
1242 | ||
ce8e922c | 1243 | _xfs_buf_ioend(bp, 1); |
1da177e4 | 1244 | bio_put(bio); |
1da177e4 LT |
1245 | } |
1246 | ||
3e85c868 DC |
1247 | static void |
1248 | xfs_buf_ioapply_map( | |
1249 | struct xfs_buf *bp, | |
1250 | int map, | |
1251 | int *buf_offset, | |
1252 | int *count, | |
1253 | int rw) | |
1da177e4 | 1254 | { |
3e85c868 DC |
1255 | int page_index; |
1256 | int total_nr_pages = bp->b_page_count; | |
1257 | int nr_pages; | |
1258 | struct bio *bio; | |
1259 | sector_t sector = bp->b_maps[map].bm_bn; | |
1260 | int size; | |
1261 | int offset; | |
1da177e4 | 1262 | |
ce8e922c | 1263 | total_nr_pages = bp->b_page_count; |
1da177e4 | 1264 | |
3e85c868 DC |
1265 | /* skip the pages in the buffer before the start offset */ |
1266 | page_index = 0; | |
1267 | offset = *buf_offset; | |
1268 | while (offset >= PAGE_SIZE) { | |
1269 | page_index++; | |
1270 | offset -= PAGE_SIZE; | |
f538d4da CH |
1271 | } |
1272 | ||
3e85c868 DC |
1273 | /* |
1274 | * Limit the IO size to the length of the current vector, and update the | |
1275 | * remaining IO count for the next time around. | |
1276 | */ | |
1277 | size = min_t(int, BBTOB(bp->b_maps[map].bm_len), *count); | |
1278 | *count -= size; | |
1279 | *buf_offset += size; | |
34951f5c | 1280 | |
1da177e4 | 1281 | next_chunk: |
ce8e922c | 1282 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1283 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1284 | if (nr_pages > total_nr_pages) | |
1285 | nr_pages = total_nr_pages; | |
1286 | ||
1287 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1288 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1289 | bio->bi_sector = sector; |
ce8e922c NS |
1290 | bio->bi_end_io = xfs_buf_bio_end_io; |
1291 | bio->bi_private = bp; | |
1da177e4 | 1292 | |
0e6e847f | 1293 | |
3e85c868 | 1294 | for (; size && nr_pages; nr_pages--, page_index++) { |
0e6e847f | 1295 | int rbytes, nbytes = PAGE_SIZE - offset; |
1da177e4 LT |
1296 | |
1297 | if (nbytes > size) | |
1298 | nbytes = size; | |
1299 | ||
3e85c868 DC |
1300 | rbytes = bio_add_page(bio, bp->b_pages[page_index], nbytes, |
1301 | offset); | |
ce8e922c | 1302 | if (rbytes < nbytes) |
1da177e4 LT |
1303 | break; |
1304 | ||
1305 | offset = 0; | |
aa0e8833 | 1306 | sector += BTOBB(nbytes); |
1da177e4 LT |
1307 | size -= nbytes; |
1308 | total_nr_pages--; | |
1309 | } | |
1310 | ||
1da177e4 | 1311 | if (likely(bio->bi_size)) { |
73c77e2c JB |
1312 | if (xfs_buf_is_vmapped(bp)) { |
1313 | flush_kernel_vmap_range(bp->b_addr, | |
1314 | xfs_buf_vmap_len(bp)); | |
1315 | } | |
1da177e4 LT |
1316 | submit_bio(rw, bio); |
1317 | if (size) | |
1318 | goto next_chunk; | |
1319 | } else { | |
37eb17e6 DC |
1320 | /* |
1321 | * This is guaranteed not to be the last io reference count | |
1322 | * because the caller (xfs_buf_iorequest) holds a count itself. | |
1323 | */ | |
1324 | atomic_dec(&bp->b_io_remaining); | |
ce8e922c | 1325 | xfs_buf_ioerror(bp, EIO); |
ec53d1db | 1326 | bio_put(bio); |
1da177e4 | 1327 | } |
3e85c868 DC |
1328 | |
1329 | } | |
1330 | ||
1331 | STATIC void | |
1332 | _xfs_buf_ioapply( | |
1333 | struct xfs_buf *bp) | |
1334 | { | |
1335 | struct blk_plug plug; | |
1336 | int rw; | |
1337 | int offset; | |
1338 | int size; | |
1339 | int i; | |
1340 | ||
c163f9a1 DC |
1341 | /* |
1342 | * Make sure we capture only current IO errors rather than stale errors | |
1343 | * left over from previous use of the buffer (e.g. failed readahead). | |
1344 | */ | |
1345 | bp->b_error = 0; | |
1346 | ||
3e85c868 DC |
1347 | if (bp->b_flags & XBF_WRITE) { |
1348 | if (bp->b_flags & XBF_SYNCIO) | |
1349 | rw = WRITE_SYNC; | |
1350 | else | |
1351 | rw = WRITE; | |
1352 | if (bp->b_flags & XBF_FUA) | |
1353 | rw |= REQ_FUA; | |
1354 | if (bp->b_flags & XBF_FLUSH) | |
1355 | rw |= REQ_FLUSH; | |
1813dd64 DC |
1356 | |
1357 | /* | |
1358 | * Run the write verifier callback function if it exists. If | |
1359 | * this function fails it will mark the buffer with an error and | |
1360 | * the IO should not be dispatched. | |
1361 | */ | |
1362 | if (bp->b_ops) { | |
1363 | bp->b_ops->verify_write(bp); | |
1364 | if (bp->b_error) { | |
1365 | xfs_force_shutdown(bp->b_target->bt_mount, | |
1366 | SHUTDOWN_CORRUPT_INCORE); | |
1367 | return; | |
1368 | } | |
1369 | } | |
3e85c868 DC |
1370 | } else if (bp->b_flags & XBF_READ_AHEAD) { |
1371 | rw = READA; | |
1372 | } else { | |
1373 | rw = READ; | |
1374 | } | |
1375 | ||
1376 | /* we only use the buffer cache for meta-data */ | |
1377 | rw |= REQ_META; | |
1378 | ||
1379 | /* | |
1380 | * Walk all the vectors issuing IO on them. Set up the initial offset | |
1381 | * into the buffer and the desired IO size before we start - | |
1382 | * _xfs_buf_ioapply_vec() will modify them appropriately for each | |
1383 | * subsequent call. | |
1384 | */ | |
1385 | offset = bp->b_offset; | |
1386 | size = BBTOB(bp->b_io_length); | |
1387 | blk_start_plug(&plug); | |
1388 | for (i = 0; i < bp->b_map_count; i++) { | |
1389 | xfs_buf_ioapply_map(bp, i, &offset, &size, rw); | |
1390 | if (bp->b_error) | |
1391 | break; | |
1392 | if (size <= 0) | |
1393 | break; /* all done */ | |
1394 | } | |
1395 | blk_finish_plug(&plug); | |
1da177e4 LT |
1396 | } |
1397 | ||
0e95f19a | 1398 | void |
ce8e922c NS |
1399 | xfs_buf_iorequest( |
1400 | xfs_buf_t *bp) | |
1da177e4 | 1401 | { |
0b1b213f | 1402 | trace_xfs_buf_iorequest(bp, _RET_IP_); |
1da177e4 | 1403 | |
43ff2122 | 1404 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); |
1da177e4 | 1405 | |
375ec69d | 1406 | if (bp->b_flags & XBF_WRITE) |
ce8e922c | 1407 | xfs_buf_wait_unpin(bp); |
ce8e922c | 1408 | xfs_buf_hold(bp); |
1da177e4 LT |
1409 | |
1410 | /* Set the count to 1 initially, this will stop an I/O | |
1411 | * completion callout which happens before we have started | |
ce8e922c | 1412 | * all the I/O from calling xfs_buf_ioend too early. |
1da177e4 | 1413 | */ |
ce8e922c NS |
1414 | atomic_set(&bp->b_io_remaining, 1); |
1415 | _xfs_buf_ioapply(bp); | |
08023d6d | 1416 | _xfs_buf_ioend(bp, 1); |
1da177e4 | 1417 | |
ce8e922c | 1418 | xfs_buf_rele(bp); |
1da177e4 LT |
1419 | } |
1420 | ||
1421 | /* | |
0e95f19a DC |
1422 | * Waits for I/O to complete on the buffer supplied. It returns immediately if |
1423 | * no I/O is pending or there is already a pending error on the buffer. It | |
1424 | * returns the I/O error code, if any, or 0 if there was no error. | |
1da177e4 LT |
1425 | */ |
1426 | int | |
ce8e922c NS |
1427 | xfs_buf_iowait( |
1428 | xfs_buf_t *bp) | |
1da177e4 | 1429 | { |
0b1b213f CH |
1430 | trace_xfs_buf_iowait(bp, _RET_IP_); |
1431 | ||
0e95f19a DC |
1432 | if (!bp->b_error) |
1433 | wait_for_completion(&bp->b_iowait); | |
0b1b213f CH |
1434 | |
1435 | trace_xfs_buf_iowait_done(bp, _RET_IP_); | |
ce8e922c | 1436 | return bp->b_error; |
1da177e4 LT |
1437 | } |
1438 | ||
ce8e922c NS |
1439 | xfs_caddr_t |
1440 | xfs_buf_offset( | |
1441 | xfs_buf_t *bp, | |
1da177e4 LT |
1442 | size_t offset) |
1443 | { | |
1444 | struct page *page; | |
1445 | ||
611c9946 | 1446 | if (bp->b_addr) |
62926044 | 1447 | return bp->b_addr + offset; |
1da177e4 | 1448 | |
ce8e922c | 1449 | offset += bp->b_offset; |
0e6e847f DC |
1450 | page = bp->b_pages[offset >> PAGE_SHIFT]; |
1451 | return (xfs_caddr_t)page_address(page) + (offset & (PAGE_SIZE-1)); | |
1da177e4 LT |
1452 | } |
1453 | ||
1454 | /* | |
1da177e4 LT |
1455 | * Move data into or out of a buffer. |
1456 | */ | |
1457 | void | |
ce8e922c NS |
1458 | xfs_buf_iomove( |
1459 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1460 | size_t boff, /* starting buffer offset */ |
1461 | size_t bsize, /* length to copy */ | |
b9c48649 | 1462 | void *data, /* data address */ |
ce8e922c | 1463 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 | 1464 | { |
795cac72 | 1465 | size_t bend; |
1da177e4 LT |
1466 | |
1467 | bend = boff + bsize; | |
1468 | while (boff < bend) { | |
795cac72 DC |
1469 | struct page *page; |
1470 | int page_index, page_offset, csize; | |
1471 | ||
1472 | page_index = (boff + bp->b_offset) >> PAGE_SHIFT; | |
1473 | page_offset = (boff + bp->b_offset) & ~PAGE_MASK; | |
1474 | page = bp->b_pages[page_index]; | |
1475 | csize = min_t(size_t, PAGE_SIZE - page_offset, | |
1476 | BBTOB(bp->b_io_length) - boff); | |
1da177e4 | 1477 | |
795cac72 | 1478 | ASSERT((csize + page_offset) <= PAGE_SIZE); |
1da177e4 LT |
1479 | |
1480 | switch (mode) { | |
ce8e922c | 1481 | case XBRW_ZERO: |
795cac72 | 1482 | memset(page_address(page) + page_offset, 0, csize); |
1da177e4 | 1483 | break; |
ce8e922c | 1484 | case XBRW_READ: |
795cac72 | 1485 | memcpy(data, page_address(page) + page_offset, csize); |
1da177e4 | 1486 | break; |
ce8e922c | 1487 | case XBRW_WRITE: |
795cac72 | 1488 | memcpy(page_address(page) + page_offset, data, csize); |
1da177e4 LT |
1489 | } |
1490 | ||
1491 | boff += csize; | |
1492 | data += csize; | |
1493 | } | |
1494 | } | |
1495 | ||
1496 | /* | |
ce8e922c | 1497 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1498 | */ |
1499 | ||
1500 | /* | |
430cbeb8 DC |
1501 | * Wait for any bufs with callbacks that have been submitted but have not yet |
1502 | * returned. These buffers will have an elevated hold count, so wait on those | |
1503 | * while freeing all the buffers only held by the LRU. | |
1da177e4 LT |
1504 | */ |
1505 | void | |
1506 | xfs_wait_buftarg( | |
74f75a0c | 1507 | struct xfs_buftarg *btp) |
1da177e4 | 1508 | { |
430cbeb8 DC |
1509 | struct xfs_buf *bp; |
1510 | ||
1511 | restart: | |
1512 | spin_lock(&btp->bt_lru_lock); | |
1513 | while (!list_empty(&btp->bt_lru)) { | |
1514 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1515 | if (atomic_read(&bp->b_hold) > 1) { | |
3b19034d DC |
1516 | trace_xfs_buf_wait_buftarg(bp, _RET_IP_); |
1517 | list_move_tail(&bp->b_lru, &btp->bt_lru); | |
430cbeb8 | 1518 | spin_unlock(&btp->bt_lru_lock); |
26af6552 | 1519 | delay(100); |
430cbeb8 | 1520 | goto restart; |
1da177e4 | 1521 | } |
430cbeb8 | 1522 | /* |
90802ed9 | 1523 | * clear the LRU reference count so the buffer doesn't get |
430cbeb8 DC |
1524 | * ignored in xfs_buf_rele(). |
1525 | */ | |
1526 | atomic_set(&bp->b_lru_ref, 0); | |
1527 | spin_unlock(&btp->bt_lru_lock); | |
1528 | xfs_buf_rele(bp); | |
1529 | spin_lock(&btp->bt_lru_lock); | |
1da177e4 | 1530 | } |
430cbeb8 | 1531 | spin_unlock(&btp->bt_lru_lock); |
1da177e4 LT |
1532 | } |
1533 | ||
ff57ab21 DC |
1534 | int |
1535 | xfs_buftarg_shrink( | |
1536 | struct shrinker *shrink, | |
1495f230 | 1537 | struct shrink_control *sc) |
a6867a68 | 1538 | { |
ff57ab21 DC |
1539 | struct xfs_buftarg *btp = container_of(shrink, |
1540 | struct xfs_buftarg, bt_shrinker); | |
430cbeb8 | 1541 | struct xfs_buf *bp; |
1495f230 | 1542 | int nr_to_scan = sc->nr_to_scan; |
430cbeb8 DC |
1543 | LIST_HEAD(dispose); |
1544 | ||
1545 | if (!nr_to_scan) | |
1546 | return btp->bt_lru_nr; | |
1547 | ||
1548 | spin_lock(&btp->bt_lru_lock); | |
1549 | while (!list_empty(&btp->bt_lru)) { | |
1550 | if (nr_to_scan-- <= 0) | |
1551 | break; | |
1552 | ||
1553 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1554 | ||
1555 | /* | |
1556 | * Decrement the b_lru_ref count unless the value is already | |
1557 | * zero. If the value is already zero, we need to reclaim the | |
1558 | * buffer, otherwise it gets another trip through the LRU. | |
1559 | */ | |
1560 | if (!atomic_add_unless(&bp->b_lru_ref, -1, 0)) { | |
1561 | list_move_tail(&bp->b_lru, &btp->bt_lru); | |
1562 | continue; | |
1563 | } | |
1564 | ||
1565 | /* | |
1566 | * remove the buffer from the LRU now to avoid needing another | |
1567 | * lock round trip inside xfs_buf_rele(). | |
1568 | */ | |
1569 | list_move(&bp->b_lru, &dispose); | |
1570 | btp->bt_lru_nr--; | |
6fb8a90a | 1571 | bp->b_lru_flags |= _XBF_LRU_DISPOSE; |
ff57ab21 | 1572 | } |
430cbeb8 DC |
1573 | spin_unlock(&btp->bt_lru_lock); |
1574 | ||
1575 | while (!list_empty(&dispose)) { | |
1576 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); | |
1577 | list_del_init(&bp->b_lru); | |
1578 | xfs_buf_rele(bp); | |
1579 | } | |
1580 | ||
1581 | return btp->bt_lru_nr; | |
a6867a68 DC |
1582 | } |
1583 | ||
1da177e4 LT |
1584 | void |
1585 | xfs_free_buftarg( | |
b7963133 CH |
1586 | struct xfs_mount *mp, |
1587 | struct xfs_buftarg *btp) | |
1da177e4 | 1588 | { |
ff57ab21 DC |
1589 | unregister_shrinker(&btp->bt_shrinker); |
1590 | ||
b7963133 CH |
1591 | if (mp->m_flags & XFS_MOUNT_BARRIER) |
1592 | xfs_blkdev_issue_flush(btp); | |
a6867a68 | 1593 | |
f0e2d93c | 1594 | kmem_free(btp); |
1da177e4 LT |
1595 | } |
1596 | ||
1da177e4 LT |
1597 | STATIC int |
1598 | xfs_setsize_buftarg_flags( | |
1599 | xfs_buftarg_t *btp, | |
1600 | unsigned int blocksize, | |
1601 | unsigned int sectorsize, | |
1602 | int verbose) | |
1603 | { | |
ce8e922c NS |
1604 | btp->bt_bsize = blocksize; |
1605 | btp->bt_sshift = ffs(sectorsize) - 1; | |
1606 | btp->bt_smask = sectorsize - 1; | |
1da177e4 | 1607 | |
ce8e922c | 1608 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
02b102df CH |
1609 | char name[BDEVNAME_SIZE]; |
1610 | ||
1611 | bdevname(btp->bt_bdev, name); | |
1612 | ||
4f10700a DC |
1613 | xfs_warn(btp->bt_mount, |
1614 | "Cannot set_blocksize to %u on device %s\n", | |
02b102df | 1615 | sectorsize, name); |
1da177e4 LT |
1616 | return EINVAL; |
1617 | } | |
1618 | ||
1da177e4 LT |
1619 | return 0; |
1620 | } | |
1621 | ||
1622 | /* | |
ce8e922c NS |
1623 | * When allocating the initial buffer target we have not yet |
1624 | * read in the superblock, so don't know what sized sectors | |
8b4ad79c | 1625 | * are being used at this early stage. Play safe. |
ce8e922c | 1626 | */ |
1da177e4 LT |
1627 | STATIC int |
1628 | xfs_setsize_buftarg_early( | |
1629 | xfs_buftarg_t *btp, | |
1630 | struct block_device *bdev) | |
1631 | { | |
1632 | return xfs_setsize_buftarg_flags(btp, | |
0e6e847f | 1633 | PAGE_SIZE, bdev_logical_block_size(bdev), 0); |
1da177e4 LT |
1634 | } |
1635 | ||
1636 | int | |
1637 | xfs_setsize_buftarg( | |
1638 | xfs_buftarg_t *btp, | |
1639 | unsigned int blocksize, | |
1640 | unsigned int sectorsize) | |
1641 | { | |
1642 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | |
1643 | } | |
1644 | ||
1da177e4 LT |
1645 | xfs_buftarg_t * |
1646 | xfs_alloc_buftarg( | |
ebad861b | 1647 | struct xfs_mount *mp, |
1da177e4 | 1648 | struct block_device *bdev, |
e2a07812 JE |
1649 | int external, |
1650 | const char *fsname) | |
1da177e4 LT |
1651 | { |
1652 | xfs_buftarg_t *btp; | |
1653 | ||
b17cb364 | 1654 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP | KM_NOFS); |
1da177e4 | 1655 | |
ebad861b | 1656 | btp->bt_mount = mp; |
ce8e922c NS |
1657 | btp->bt_dev = bdev->bd_dev; |
1658 | btp->bt_bdev = bdev; | |
0e6e847f DC |
1659 | btp->bt_bdi = blk_get_backing_dev_info(bdev); |
1660 | if (!btp->bt_bdi) | |
1661 | goto error; | |
1662 | ||
430cbeb8 DC |
1663 | INIT_LIST_HEAD(&btp->bt_lru); |
1664 | spin_lock_init(&btp->bt_lru_lock); | |
1da177e4 LT |
1665 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1666 | goto error; | |
ff57ab21 DC |
1667 | btp->bt_shrinker.shrink = xfs_buftarg_shrink; |
1668 | btp->bt_shrinker.seeks = DEFAULT_SEEKS; | |
1669 | register_shrinker(&btp->bt_shrinker); | |
1da177e4 LT |
1670 | return btp; |
1671 | ||
1672 | error: | |
f0e2d93c | 1673 | kmem_free(btp); |
1da177e4 LT |
1674 | return NULL; |
1675 | } | |
1676 | ||
1da177e4 | 1677 | /* |
43ff2122 CH |
1678 | * Add a buffer to the delayed write list. |
1679 | * | |
1680 | * This queues a buffer for writeout if it hasn't already been. Note that | |
1681 | * neither this routine nor the buffer list submission functions perform | |
1682 | * any internal synchronization. It is expected that the lists are thread-local | |
1683 | * to the callers. | |
1684 | * | |
1685 | * Returns true if we queued up the buffer, or false if it already had | |
1686 | * been on the buffer list. | |
1da177e4 | 1687 | */ |
43ff2122 | 1688 | bool |
ce8e922c | 1689 | xfs_buf_delwri_queue( |
43ff2122 CH |
1690 | struct xfs_buf *bp, |
1691 | struct list_head *list) | |
1da177e4 | 1692 | { |
43ff2122 | 1693 | ASSERT(xfs_buf_islocked(bp)); |
5a8ee6ba | 1694 | ASSERT(!(bp->b_flags & XBF_READ)); |
1da177e4 | 1695 | |
43ff2122 CH |
1696 | /* |
1697 | * If the buffer is already marked delwri it already is queued up | |
1698 | * by someone else for imediate writeout. Just ignore it in that | |
1699 | * case. | |
1700 | */ | |
1701 | if (bp->b_flags & _XBF_DELWRI_Q) { | |
1702 | trace_xfs_buf_delwri_queued(bp, _RET_IP_); | |
1703 | return false; | |
1da177e4 | 1704 | } |
1da177e4 | 1705 | |
43ff2122 | 1706 | trace_xfs_buf_delwri_queue(bp, _RET_IP_); |
d808f617 DC |
1707 | |
1708 | /* | |
43ff2122 CH |
1709 | * If a buffer gets written out synchronously or marked stale while it |
1710 | * is on a delwri list we lazily remove it. To do this, the other party | |
1711 | * clears the _XBF_DELWRI_Q flag but otherwise leaves the buffer alone. | |
1712 | * It remains referenced and on the list. In a rare corner case it | |
1713 | * might get readded to a delwri list after the synchronous writeout, in | |
1714 | * which case we need just need to re-add the flag here. | |
d808f617 | 1715 | */ |
43ff2122 CH |
1716 | bp->b_flags |= _XBF_DELWRI_Q; |
1717 | if (list_empty(&bp->b_list)) { | |
1718 | atomic_inc(&bp->b_hold); | |
1719 | list_add_tail(&bp->b_list, list); | |
585e6d88 | 1720 | } |
585e6d88 | 1721 | |
43ff2122 | 1722 | return true; |
585e6d88 DC |
1723 | } |
1724 | ||
089716aa DC |
1725 | /* |
1726 | * Compare function is more complex than it needs to be because | |
1727 | * the return value is only 32 bits and we are doing comparisons | |
1728 | * on 64 bit values | |
1729 | */ | |
1730 | static int | |
1731 | xfs_buf_cmp( | |
1732 | void *priv, | |
1733 | struct list_head *a, | |
1734 | struct list_head *b) | |
1735 | { | |
1736 | struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list); | |
1737 | struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); | |
1738 | xfs_daddr_t diff; | |
1739 | ||
f4b42421 | 1740 | diff = ap->b_maps[0].bm_bn - bp->b_maps[0].bm_bn; |
089716aa DC |
1741 | if (diff < 0) |
1742 | return -1; | |
1743 | if (diff > 0) | |
1744 | return 1; | |
1745 | return 0; | |
1746 | } | |
1747 | ||
43ff2122 CH |
1748 | static int |
1749 | __xfs_buf_delwri_submit( | |
1750 | struct list_head *buffer_list, | |
1751 | struct list_head *io_list, | |
1752 | bool wait) | |
1da177e4 | 1753 | { |
43ff2122 CH |
1754 | struct blk_plug plug; |
1755 | struct xfs_buf *bp, *n; | |
1756 | int pinned = 0; | |
1757 | ||
1758 | list_for_each_entry_safe(bp, n, buffer_list, b_list) { | |
1759 | if (!wait) { | |
1760 | if (xfs_buf_ispinned(bp)) { | |
1761 | pinned++; | |
1762 | continue; | |
1763 | } | |
1764 | if (!xfs_buf_trylock(bp)) | |
1765 | continue; | |
1766 | } else { | |
1767 | xfs_buf_lock(bp); | |
1768 | } | |
978c7b2f | 1769 | |
43ff2122 CH |
1770 | /* |
1771 | * Someone else might have written the buffer synchronously or | |
1772 | * marked it stale in the meantime. In that case only the | |
1773 | * _XBF_DELWRI_Q flag got cleared, and we have to drop the | |
1774 | * reference and remove it from the list here. | |
1775 | */ | |
1776 | if (!(bp->b_flags & _XBF_DELWRI_Q)) { | |
1777 | list_del_init(&bp->b_list); | |
1778 | xfs_buf_relse(bp); | |
1779 | continue; | |
1780 | } | |
c9c12971 | 1781 | |
43ff2122 CH |
1782 | list_move_tail(&bp->b_list, io_list); |
1783 | trace_xfs_buf_delwri_split(bp, _RET_IP_); | |
1784 | } | |
1da177e4 | 1785 | |
43ff2122 | 1786 | list_sort(NULL, io_list, xfs_buf_cmp); |
1da177e4 | 1787 | |
43ff2122 CH |
1788 | blk_start_plug(&plug); |
1789 | list_for_each_entry_safe(bp, n, io_list, b_list) { | |
1790 | bp->b_flags &= ~(_XBF_DELWRI_Q | XBF_ASYNC); | |
1791 | bp->b_flags |= XBF_WRITE; | |
a1b7ea5d | 1792 | |
43ff2122 CH |
1793 | if (!wait) { |
1794 | bp->b_flags |= XBF_ASYNC; | |
ce8e922c | 1795 | list_del_init(&bp->b_list); |
1da177e4 | 1796 | } |
43ff2122 CH |
1797 | xfs_bdstrat_cb(bp); |
1798 | } | |
1799 | blk_finish_plug(&plug); | |
1da177e4 | 1800 | |
43ff2122 | 1801 | return pinned; |
1da177e4 LT |
1802 | } |
1803 | ||
1804 | /* | |
43ff2122 CH |
1805 | * Write out a buffer list asynchronously. |
1806 | * | |
1807 | * This will take the @buffer_list, write all non-locked and non-pinned buffers | |
1808 | * out and not wait for I/O completion on any of the buffers. This interface | |
1809 | * is only safely useable for callers that can track I/O completion by higher | |
1810 | * level means, e.g. AIL pushing as the @buffer_list is consumed in this | |
1811 | * function. | |
1da177e4 LT |
1812 | */ |
1813 | int | |
43ff2122 CH |
1814 | xfs_buf_delwri_submit_nowait( |
1815 | struct list_head *buffer_list) | |
1da177e4 | 1816 | { |
43ff2122 CH |
1817 | LIST_HEAD (io_list); |
1818 | return __xfs_buf_delwri_submit(buffer_list, &io_list, false); | |
1819 | } | |
1da177e4 | 1820 | |
43ff2122 CH |
1821 | /* |
1822 | * Write out a buffer list synchronously. | |
1823 | * | |
1824 | * This will take the @buffer_list, write all buffers out and wait for I/O | |
1825 | * completion on all of the buffers. @buffer_list is consumed by the function, | |
1826 | * so callers must have some other way of tracking buffers if they require such | |
1827 | * functionality. | |
1828 | */ | |
1829 | int | |
1830 | xfs_buf_delwri_submit( | |
1831 | struct list_head *buffer_list) | |
1832 | { | |
1833 | LIST_HEAD (io_list); | |
1834 | int error = 0, error2; | |
1835 | struct xfs_buf *bp; | |
1da177e4 | 1836 | |
43ff2122 | 1837 | __xfs_buf_delwri_submit(buffer_list, &io_list, true); |
1da177e4 | 1838 | |
43ff2122 CH |
1839 | /* Wait for IO to complete. */ |
1840 | while (!list_empty(&io_list)) { | |
1841 | bp = list_first_entry(&io_list, struct xfs_buf, b_list); | |
a1b7ea5d | 1842 | |
089716aa | 1843 | list_del_init(&bp->b_list); |
43ff2122 CH |
1844 | error2 = xfs_buf_iowait(bp); |
1845 | xfs_buf_relse(bp); | |
1846 | if (!error) | |
1847 | error = error2; | |
1da177e4 LT |
1848 | } |
1849 | ||
43ff2122 | 1850 | return error; |
1da177e4 LT |
1851 | } |
1852 | ||
04d8b284 | 1853 | int __init |
ce8e922c | 1854 | xfs_buf_init(void) |
1da177e4 | 1855 | { |
8758280f NS |
1856 | xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf", |
1857 | KM_ZONE_HWALIGN, NULL); | |
ce8e922c | 1858 | if (!xfs_buf_zone) |
0b1b213f | 1859 | goto out; |
04d8b284 | 1860 | |
51749e47 | 1861 | xfslogd_workqueue = alloc_workqueue("xfslogd", |
6370a6ad | 1862 | WQ_MEM_RECLAIM | WQ_HIGHPRI, 1); |
23ea4032 | 1863 | if (!xfslogd_workqueue) |
04d8b284 | 1864 | goto out_free_buf_zone; |
1da177e4 | 1865 | |
23ea4032 | 1866 | return 0; |
1da177e4 | 1867 | |
23ea4032 | 1868 | out_free_buf_zone: |
ce8e922c | 1869 | kmem_zone_destroy(xfs_buf_zone); |
0b1b213f | 1870 | out: |
8758280f | 1871 | return -ENOMEM; |
1da177e4 LT |
1872 | } |
1873 | ||
1da177e4 | 1874 | void |
ce8e922c | 1875 | xfs_buf_terminate(void) |
1da177e4 | 1876 | { |
04d8b284 | 1877 | destroy_workqueue(xfslogd_workqueue); |
ce8e922c | 1878 | kmem_zone_destroy(xfs_buf_zone); |
1da177e4 | 1879 | } |