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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> |
5b3cc15a | 36 | #include <linux/sched/mm.h> |
1da177e4 | 37 | |
4fb6e8ad | 38 | #include "xfs_format.h" |
239880ef | 39 | #include "xfs_log_format.h" |
7fd36c44 | 40 | #include "xfs_trans_resv.h" |
239880ef | 41 | #include "xfs_sb.h" |
b7963133 | 42 | #include "xfs_mount.h" |
0b1b213f | 43 | #include "xfs_trace.h" |
239880ef | 44 | #include "xfs_log.h" |
b7963133 | 45 | |
7989cb8e | 46 | static kmem_zone_t *xfs_buf_zone; |
23ea4032 | 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 | ||
9c7504aa BF |
83 | /* |
84 | * Bump the I/O in flight count on the buftarg if we haven't yet done so for | |
85 | * this buffer. The count is incremented once per buffer (per hold cycle) | |
86 | * because the corresponding decrement is deferred to buffer release. Buffers | |
87 | * can undergo I/O multiple times in a hold-release cycle and per buffer I/O | |
88 | * tracking adds unnecessary overhead. This is used for sychronization purposes | |
89 | * with unmount (see xfs_wait_buftarg()), so all we really need is a count of | |
90 | * in-flight buffers. | |
91 | * | |
92 | * Buffers that are never released (e.g., superblock, iclog buffers) must set | |
93 | * the XBF_NO_IOACCT flag before I/O submission. Otherwise, the buftarg count | |
94 | * never reaches zero and unmount hangs indefinitely. | |
95 | */ | |
96 | static inline void | |
97 | xfs_buf_ioacct_inc( | |
98 | struct xfs_buf *bp) | |
99 | { | |
100 | if (bp->b_flags & (XBF_NO_IOACCT|_XBF_IN_FLIGHT)) | |
101 | return; | |
102 | ||
103 | ASSERT(bp->b_flags & XBF_ASYNC); | |
104 | bp->b_flags |= _XBF_IN_FLIGHT; | |
105 | percpu_counter_inc(&bp->b_target->bt_io_count); | |
106 | } | |
107 | ||
108 | /* | |
109 | * Clear the in-flight state on a buffer about to be released to the LRU or | |
110 | * freed and unaccount from the buftarg. | |
111 | */ | |
112 | static inline void | |
113 | xfs_buf_ioacct_dec( | |
114 | struct xfs_buf *bp) | |
115 | { | |
116 | if (!(bp->b_flags & _XBF_IN_FLIGHT)) | |
117 | return; | |
118 | ||
9c7504aa BF |
119 | bp->b_flags &= ~_XBF_IN_FLIGHT; |
120 | percpu_counter_dec(&bp->b_target->bt_io_count); | |
121 | } | |
122 | ||
430cbeb8 DC |
123 | /* |
124 | * When we mark a buffer stale, we remove the buffer from the LRU and clear the | |
125 | * b_lru_ref count so that the buffer is freed immediately when the buffer | |
126 | * reference count falls to zero. If the buffer is already on the LRU, we need | |
127 | * to remove the reference that LRU holds on the buffer. | |
128 | * | |
129 | * This prevents build-up of stale buffers on the LRU. | |
130 | */ | |
131 | void | |
132 | xfs_buf_stale( | |
133 | struct xfs_buf *bp) | |
134 | { | |
43ff2122 CH |
135 | ASSERT(xfs_buf_islocked(bp)); |
136 | ||
430cbeb8 | 137 | bp->b_flags |= XBF_STALE; |
43ff2122 CH |
138 | |
139 | /* | |
140 | * Clear the delwri status so that a delwri queue walker will not | |
141 | * flush this buffer to disk now that it is stale. The delwri queue has | |
142 | * a reference to the buffer, so this is safe to do. | |
143 | */ | |
144 | bp->b_flags &= ~_XBF_DELWRI_Q; | |
145 | ||
9c7504aa BF |
146 | /* |
147 | * Once the buffer is marked stale and unlocked, a subsequent lookup | |
148 | * could reset b_flags. There is no guarantee that the buffer is | |
149 | * unaccounted (released to LRU) before that occurs. Drop in-flight | |
150 | * status now to preserve accounting consistency. | |
151 | */ | |
152 | xfs_buf_ioacct_dec(bp); | |
153 | ||
a4082357 DC |
154 | spin_lock(&bp->b_lock); |
155 | atomic_set(&bp->b_lru_ref, 0); | |
156 | if (!(bp->b_state & XFS_BSTATE_DISPOSE) && | |
e80dfa19 DC |
157 | (list_lru_del(&bp->b_target->bt_lru, &bp->b_lru))) |
158 | atomic_dec(&bp->b_hold); | |
159 | ||
430cbeb8 | 160 | ASSERT(atomic_read(&bp->b_hold) >= 1); |
a4082357 | 161 | spin_unlock(&bp->b_lock); |
430cbeb8 | 162 | } |
1da177e4 | 163 | |
3e85c868 DC |
164 | static int |
165 | xfs_buf_get_maps( | |
166 | struct xfs_buf *bp, | |
167 | int map_count) | |
168 | { | |
169 | ASSERT(bp->b_maps == NULL); | |
170 | bp->b_map_count = map_count; | |
171 | ||
172 | if (map_count == 1) { | |
f4b42421 | 173 | bp->b_maps = &bp->__b_map; |
3e85c868 DC |
174 | return 0; |
175 | } | |
176 | ||
177 | bp->b_maps = kmem_zalloc(map_count * sizeof(struct xfs_buf_map), | |
178 | KM_NOFS); | |
179 | if (!bp->b_maps) | |
2451337d | 180 | return -ENOMEM; |
3e85c868 DC |
181 | return 0; |
182 | } | |
183 | ||
184 | /* | |
185 | * Frees b_pages if it was allocated. | |
186 | */ | |
187 | static void | |
188 | xfs_buf_free_maps( | |
189 | struct xfs_buf *bp) | |
190 | { | |
f4b42421 | 191 | if (bp->b_maps != &bp->__b_map) { |
3e85c868 DC |
192 | kmem_free(bp->b_maps); |
193 | bp->b_maps = NULL; | |
194 | } | |
195 | } | |
196 | ||
4347b9d7 | 197 | struct xfs_buf * |
3e85c868 | 198 | _xfs_buf_alloc( |
4347b9d7 | 199 | struct xfs_buftarg *target, |
3e85c868 DC |
200 | struct xfs_buf_map *map, |
201 | int nmaps, | |
ce8e922c | 202 | xfs_buf_flags_t flags) |
1da177e4 | 203 | { |
4347b9d7 | 204 | struct xfs_buf *bp; |
3e85c868 DC |
205 | int error; |
206 | int i; | |
4347b9d7 | 207 | |
aa5c158e | 208 | bp = kmem_zone_zalloc(xfs_buf_zone, KM_NOFS); |
4347b9d7 CH |
209 | if (unlikely(!bp)) |
210 | return NULL; | |
211 | ||
1da177e4 | 212 | /* |
12bcb3f7 DC |
213 | * We don't want certain flags to appear in b_flags unless they are |
214 | * specifically set by later operations on the buffer. | |
1da177e4 | 215 | */ |
611c9946 | 216 | flags &= ~(XBF_UNMAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD); |
ce8e922c | 217 | |
ce8e922c | 218 | atomic_set(&bp->b_hold, 1); |
430cbeb8 | 219 | atomic_set(&bp->b_lru_ref, 1); |
b4dd330b | 220 | init_completion(&bp->b_iowait); |
430cbeb8 | 221 | INIT_LIST_HEAD(&bp->b_lru); |
ce8e922c | 222 | INIT_LIST_HEAD(&bp->b_list); |
a731cd11 | 223 | sema_init(&bp->b_sema, 0); /* held, no waiters */ |
a4082357 | 224 | spin_lock_init(&bp->b_lock); |
ce8e922c NS |
225 | XB_SET_OWNER(bp); |
226 | bp->b_target = target; | |
3e85c868 | 227 | bp->b_flags = flags; |
de1cbee4 | 228 | |
1da177e4 | 229 | /* |
aa0e8833 DC |
230 | * Set length and io_length to the same value initially. |
231 | * I/O routines should use io_length, which will be the same in | |
1da177e4 LT |
232 | * most cases but may be reset (e.g. XFS recovery). |
233 | */ | |
3e85c868 DC |
234 | error = xfs_buf_get_maps(bp, nmaps); |
235 | if (error) { | |
236 | kmem_zone_free(xfs_buf_zone, bp); | |
237 | return NULL; | |
238 | } | |
239 | ||
240 | bp->b_bn = map[0].bm_bn; | |
241 | bp->b_length = 0; | |
242 | for (i = 0; i < nmaps; i++) { | |
243 | bp->b_maps[i].bm_bn = map[i].bm_bn; | |
244 | bp->b_maps[i].bm_len = map[i].bm_len; | |
245 | bp->b_length += map[i].bm_len; | |
246 | } | |
247 | bp->b_io_length = bp->b_length; | |
248 | ||
ce8e922c NS |
249 | atomic_set(&bp->b_pin_count, 0); |
250 | init_waitqueue_head(&bp->b_waiters); | |
251 | ||
ff6d6af2 | 252 | XFS_STATS_INC(target->bt_mount, xb_create); |
0b1b213f | 253 | trace_xfs_buf_init(bp, _RET_IP_); |
4347b9d7 CH |
254 | |
255 | return bp; | |
1da177e4 LT |
256 | } |
257 | ||
258 | /* | |
ce8e922c NS |
259 | * Allocate a page array capable of holding a specified number |
260 | * of pages, and point the page buf at it. | |
1da177e4 LT |
261 | */ |
262 | STATIC int | |
ce8e922c NS |
263 | _xfs_buf_get_pages( |
264 | xfs_buf_t *bp, | |
87937bf8 | 265 | int page_count) |
1da177e4 LT |
266 | { |
267 | /* Make sure that we have a page list */ | |
ce8e922c | 268 | if (bp->b_pages == NULL) { |
ce8e922c NS |
269 | bp->b_page_count = page_count; |
270 | if (page_count <= XB_PAGES) { | |
271 | bp->b_pages = bp->b_page_array; | |
1da177e4 | 272 | } else { |
ce8e922c | 273 | bp->b_pages = kmem_alloc(sizeof(struct page *) * |
aa5c158e | 274 | page_count, KM_NOFS); |
ce8e922c | 275 | if (bp->b_pages == NULL) |
1da177e4 LT |
276 | return -ENOMEM; |
277 | } | |
ce8e922c | 278 | memset(bp->b_pages, 0, sizeof(struct page *) * page_count); |
1da177e4 LT |
279 | } |
280 | return 0; | |
281 | } | |
282 | ||
283 | /* | |
ce8e922c | 284 | * Frees b_pages if it was allocated. |
1da177e4 LT |
285 | */ |
286 | STATIC void | |
ce8e922c | 287 | _xfs_buf_free_pages( |
1da177e4 LT |
288 | xfs_buf_t *bp) |
289 | { | |
ce8e922c | 290 | if (bp->b_pages != bp->b_page_array) { |
f0e2d93c | 291 | kmem_free(bp->b_pages); |
3fc98b1a | 292 | bp->b_pages = NULL; |
1da177e4 LT |
293 | } |
294 | } | |
295 | ||
296 | /* | |
297 | * Releases the specified buffer. | |
298 | * | |
299 | * The modification state of any associated pages is left unchanged. | |
b46fe825 | 300 | * The buffer must not be on any hash - use xfs_buf_rele instead for |
1da177e4 LT |
301 | * hashed and refcounted buffers |
302 | */ | |
303 | void | |
ce8e922c | 304 | xfs_buf_free( |
1da177e4 LT |
305 | xfs_buf_t *bp) |
306 | { | |
0b1b213f | 307 | trace_xfs_buf_free(bp, _RET_IP_); |
1da177e4 | 308 | |
430cbeb8 DC |
309 | ASSERT(list_empty(&bp->b_lru)); |
310 | ||
0e6e847f | 311 | if (bp->b_flags & _XBF_PAGES) { |
1da177e4 LT |
312 | uint i; |
313 | ||
73c77e2c | 314 | if (xfs_buf_is_vmapped(bp)) |
8a262e57 AE |
315 | vm_unmap_ram(bp->b_addr - bp->b_offset, |
316 | bp->b_page_count); | |
1da177e4 | 317 | |
948ecdb4 NS |
318 | for (i = 0; i < bp->b_page_count; i++) { |
319 | struct page *page = bp->b_pages[i]; | |
320 | ||
0e6e847f | 321 | __free_page(page); |
948ecdb4 | 322 | } |
0e6e847f DC |
323 | } else if (bp->b_flags & _XBF_KMEM) |
324 | kmem_free(bp->b_addr); | |
3fc98b1a | 325 | _xfs_buf_free_pages(bp); |
3e85c868 | 326 | xfs_buf_free_maps(bp); |
4347b9d7 | 327 | kmem_zone_free(xfs_buf_zone, bp); |
1da177e4 LT |
328 | } |
329 | ||
330 | /* | |
0e6e847f | 331 | * Allocates all the pages for buffer in question and builds it's page list. |
1da177e4 LT |
332 | */ |
333 | STATIC int | |
0e6e847f | 334 | xfs_buf_allocate_memory( |
1da177e4 LT |
335 | xfs_buf_t *bp, |
336 | uint flags) | |
337 | { | |
aa0e8833 | 338 | size_t size; |
1da177e4 | 339 | size_t nbytes, offset; |
ce8e922c | 340 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 | 341 | unsigned short page_count, i; |
795cac72 | 342 | xfs_off_t start, end; |
1da177e4 LT |
343 | int error; |
344 | ||
0e6e847f DC |
345 | /* |
346 | * for buffers that are contained within a single page, just allocate | |
347 | * the memory from the heap - there's no need for the complexity of | |
348 | * page arrays to keep allocation down to order 0. | |
349 | */ | |
795cac72 DC |
350 | size = BBTOB(bp->b_length); |
351 | if (size < PAGE_SIZE) { | |
aa5c158e | 352 | bp->b_addr = kmem_alloc(size, KM_NOFS); |
0e6e847f DC |
353 | if (!bp->b_addr) { |
354 | /* low memory - use alloc_page loop instead */ | |
355 | goto use_alloc_page; | |
356 | } | |
357 | ||
795cac72 | 358 | if (((unsigned long)(bp->b_addr + size - 1) & PAGE_MASK) != |
0e6e847f DC |
359 | ((unsigned long)bp->b_addr & PAGE_MASK)) { |
360 | /* b_addr spans two pages - use alloc_page instead */ | |
361 | kmem_free(bp->b_addr); | |
362 | bp->b_addr = NULL; | |
363 | goto use_alloc_page; | |
364 | } | |
365 | bp->b_offset = offset_in_page(bp->b_addr); | |
366 | bp->b_pages = bp->b_page_array; | |
367 | bp->b_pages[0] = virt_to_page(bp->b_addr); | |
368 | bp->b_page_count = 1; | |
611c9946 | 369 | bp->b_flags |= _XBF_KMEM; |
0e6e847f DC |
370 | return 0; |
371 | } | |
372 | ||
373 | use_alloc_page: | |
f4b42421 MT |
374 | start = BBTOB(bp->b_maps[0].bm_bn) >> PAGE_SHIFT; |
375 | end = (BBTOB(bp->b_maps[0].bm_bn + bp->b_length) + PAGE_SIZE - 1) | |
cbb7baab | 376 | >> PAGE_SHIFT; |
795cac72 | 377 | page_count = end - start; |
87937bf8 | 378 | error = _xfs_buf_get_pages(bp, page_count); |
1da177e4 LT |
379 | if (unlikely(error)) |
380 | return error; | |
1da177e4 | 381 | |
ce8e922c | 382 | offset = bp->b_offset; |
0e6e847f | 383 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 384 | |
ce8e922c | 385 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
386 | struct page *page; |
387 | uint retries = 0; | |
0e6e847f DC |
388 | retry: |
389 | page = alloc_page(gfp_mask); | |
1da177e4 | 390 | if (unlikely(page == NULL)) { |
ce8e922c NS |
391 | if (flags & XBF_READ_AHEAD) { |
392 | bp->b_page_count = i; | |
2451337d | 393 | error = -ENOMEM; |
0e6e847f | 394 | goto out_free_pages; |
1da177e4 LT |
395 | } |
396 | ||
397 | /* | |
398 | * This could deadlock. | |
399 | * | |
400 | * But until all the XFS lowlevel code is revamped to | |
401 | * handle buffer allocation failures we can't do much. | |
402 | */ | |
403 | if (!(++retries % 100)) | |
4f10700a | 404 | xfs_err(NULL, |
5bf97b1c TH |
405 | "%s(%u) possible memory allocation deadlock in %s (mode:0x%x)", |
406 | current->comm, current->pid, | |
34a622b2 | 407 | __func__, gfp_mask); |
1da177e4 | 408 | |
ff6d6af2 | 409 | XFS_STATS_INC(bp->b_target->bt_mount, xb_page_retries); |
8aa7e847 | 410 | congestion_wait(BLK_RW_ASYNC, HZ/50); |
1da177e4 LT |
411 | goto retry; |
412 | } | |
413 | ||
ff6d6af2 | 414 | XFS_STATS_INC(bp->b_target->bt_mount, xb_page_found); |
1da177e4 | 415 | |
0e6e847f | 416 | nbytes = min_t(size_t, size, PAGE_SIZE - offset); |
1da177e4 | 417 | size -= nbytes; |
ce8e922c | 418 | bp->b_pages[i] = page; |
1da177e4 LT |
419 | offset = 0; |
420 | } | |
0e6e847f | 421 | return 0; |
1da177e4 | 422 | |
0e6e847f DC |
423 | out_free_pages: |
424 | for (i = 0; i < bp->b_page_count; i++) | |
425 | __free_page(bp->b_pages[i]); | |
2aa6ba7b | 426 | bp->b_flags &= ~_XBF_PAGES; |
1da177e4 LT |
427 | return error; |
428 | } | |
429 | ||
430 | /* | |
25985edc | 431 | * Map buffer into kernel address-space if necessary. |
1da177e4 LT |
432 | */ |
433 | STATIC int | |
ce8e922c | 434 | _xfs_buf_map_pages( |
1da177e4 LT |
435 | xfs_buf_t *bp, |
436 | uint flags) | |
437 | { | |
0e6e847f | 438 | ASSERT(bp->b_flags & _XBF_PAGES); |
ce8e922c | 439 | if (bp->b_page_count == 1) { |
0e6e847f | 440 | /* A single page buffer is always mappable */ |
ce8e922c | 441 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; |
611c9946 DC |
442 | } else if (flags & XBF_UNMAPPED) { |
443 | bp->b_addr = NULL; | |
444 | } else { | |
a19fb380 | 445 | int retried = 0; |
ae687e58 DC |
446 | unsigned noio_flag; |
447 | ||
448 | /* | |
449 | * vm_map_ram() will allocate auxillary structures (e.g. | |
450 | * pagetables) with GFP_KERNEL, yet we are likely to be under | |
451 | * GFP_NOFS context here. Hence we need to tell memory reclaim | |
452 | * that we are in such a context via PF_MEMALLOC_NOIO to prevent | |
453 | * memory reclaim re-entering the filesystem here and | |
454 | * potentially deadlocking. | |
455 | */ | |
456 | noio_flag = memalloc_noio_save(); | |
a19fb380 DC |
457 | do { |
458 | bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, | |
459 | -1, PAGE_KERNEL); | |
460 | if (bp->b_addr) | |
461 | break; | |
462 | vm_unmap_aliases(); | |
463 | } while (retried++ <= 1); | |
ae687e58 | 464 | memalloc_noio_restore(noio_flag); |
a19fb380 DC |
465 | |
466 | if (!bp->b_addr) | |
1da177e4 | 467 | return -ENOMEM; |
ce8e922c | 468 | bp->b_addr += bp->b_offset; |
1da177e4 LT |
469 | } |
470 | ||
471 | return 0; | |
472 | } | |
473 | ||
474 | /* | |
475 | * Finding and Reading Buffers | |
476 | */ | |
6031e73a LS |
477 | static int |
478 | _xfs_buf_obj_cmp( | |
479 | struct rhashtable_compare_arg *arg, | |
480 | const void *obj) | |
481 | { | |
482 | const struct xfs_buf_map *map = arg->key; | |
483 | const struct xfs_buf *bp = obj; | |
484 | ||
485 | /* | |
486 | * The key hashing in the lookup path depends on the key being the | |
487 | * first element of the compare_arg, make sure to assert this. | |
488 | */ | |
489 | BUILD_BUG_ON(offsetof(struct xfs_buf_map, bm_bn) != 0); | |
490 | ||
491 | if (bp->b_bn != map->bm_bn) | |
492 | return 1; | |
493 | ||
494 | if (unlikely(bp->b_length != map->bm_len)) { | |
495 | /* | |
496 | * found a block number match. If the range doesn't | |
497 | * match, the only way this is allowed is if the buffer | |
498 | * in the cache is stale and the transaction that made | |
499 | * it stale has not yet committed. i.e. we are | |
500 | * reallocating a busy extent. Skip this buffer and | |
501 | * continue searching for an exact match. | |
502 | */ | |
503 | ASSERT(bp->b_flags & XBF_STALE); | |
504 | return 1; | |
505 | } | |
506 | return 0; | |
507 | } | |
508 | ||
509 | static const struct rhashtable_params xfs_buf_hash_params = { | |
510 | .min_size = 32, /* empty AGs have minimal footprint */ | |
511 | .nelem_hint = 16, | |
512 | .key_len = sizeof(xfs_daddr_t), | |
513 | .key_offset = offsetof(struct xfs_buf, b_bn), | |
514 | .head_offset = offsetof(struct xfs_buf, b_rhash_head), | |
515 | .automatic_shrinking = true, | |
516 | .obj_cmpfn = _xfs_buf_obj_cmp, | |
517 | }; | |
518 | ||
519 | int | |
520 | xfs_buf_hash_init( | |
521 | struct xfs_perag *pag) | |
522 | { | |
523 | spin_lock_init(&pag->pag_buf_lock); | |
524 | return rhashtable_init(&pag->pag_buf_hash, &xfs_buf_hash_params); | |
525 | } | |
526 | ||
527 | void | |
528 | xfs_buf_hash_destroy( | |
529 | struct xfs_perag *pag) | |
530 | { | |
531 | rhashtable_destroy(&pag->pag_buf_hash); | |
532 | } | |
1da177e4 LT |
533 | |
534 | /* | |
ce8e922c | 535 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 | 536 | * a given range of an inode. The buffer is returned |
eabbaf11 | 537 | * locked. No I/O is implied by this call. |
1da177e4 LT |
538 | */ |
539 | xfs_buf_t * | |
ce8e922c | 540 | _xfs_buf_find( |
e70b73f8 | 541 | struct xfs_buftarg *btp, |
3e85c868 DC |
542 | struct xfs_buf_map *map, |
543 | int nmaps, | |
ce8e922c NS |
544 | xfs_buf_flags_t flags, |
545 | xfs_buf_t *new_bp) | |
1da177e4 | 546 | { |
74f75a0c | 547 | struct xfs_perag *pag; |
74f75a0c | 548 | xfs_buf_t *bp; |
6031e73a | 549 | struct xfs_buf_map cmap = { .bm_bn = map[0].bm_bn }; |
10616b80 | 550 | xfs_daddr_t eofs; |
3e85c868 | 551 | int i; |
1da177e4 | 552 | |
3e85c868 | 553 | for (i = 0; i < nmaps; i++) |
6031e73a | 554 | cmap.bm_len += map[i].bm_len; |
1da177e4 LT |
555 | |
556 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
6031e73a LS |
557 | ASSERT(!(BBTOB(cmap.bm_len) < btp->bt_meta_sectorsize)); |
558 | ASSERT(!(BBTOB(cmap.bm_bn) & (xfs_off_t)btp->bt_meta_sectormask)); | |
1da177e4 | 559 | |
10616b80 DC |
560 | /* |
561 | * Corrupted block numbers can get through to here, unfortunately, so we | |
562 | * have to check that the buffer falls within the filesystem bounds. | |
563 | */ | |
564 | eofs = XFS_FSB_TO_BB(btp->bt_mount, btp->bt_mount->m_sb.sb_dblocks); | |
6031e73a | 565 | if (cmap.bm_bn < 0 || cmap.bm_bn >= eofs) { |
10616b80 | 566 | /* |
2451337d | 567 | * XXX (dgc): we should really be returning -EFSCORRUPTED here, |
10616b80 DC |
568 | * but none of the higher level infrastructure supports |
569 | * returning a specific error on buffer lookup failures. | |
570 | */ | |
571 | xfs_alert(btp->bt_mount, | |
572 | "%s: Block out of range: block 0x%llx, EOFS 0x%llx ", | |
6031e73a | 573 | __func__, cmap.bm_bn, eofs); |
7bc0dc27 | 574 | WARN_ON(1); |
10616b80 DC |
575 | return NULL; |
576 | } | |
577 | ||
74f75a0c | 578 | pag = xfs_perag_get(btp->bt_mount, |
6031e73a | 579 | xfs_daddr_to_agno(btp->bt_mount, cmap.bm_bn)); |
74f75a0c | 580 | |
74f75a0c | 581 | spin_lock(&pag->pag_buf_lock); |
6031e73a LS |
582 | bp = rhashtable_lookup_fast(&pag->pag_buf_hash, &cmap, |
583 | xfs_buf_hash_params); | |
584 | if (bp) { | |
585 | atomic_inc(&bp->b_hold); | |
586 | goto found; | |
1da177e4 LT |
587 | } |
588 | ||
589 | /* No match found */ | |
ce8e922c | 590 | if (new_bp) { |
74f75a0c DC |
591 | /* the buffer keeps the perag reference until it is freed */ |
592 | new_bp->b_pag = pag; | |
6031e73a LS |
593 | rhashtable_insert_fast(&pag->pag_buf_hash, |
594 | &new_bp->b_rhash_head, | |
595 | xfs_buf_hash_params); | |
74f75a0c | 596 | spin_unlock(&pag->pag_buf_lock); |
1da177e4 | 597 | } else { |
ff6d6af2 | 598 | XFS_STATS_INC(btp->bt_mount, xb_miss_locked); |
74f75a0c DC |
599 | spin_unlock(&pag->pag_buf_lock); |
600 | xfs_perag_put(pag); | |
1da177e4 | 601 | } |
ce8e922c | 602 | return new_bp; |
1da177e4 LT |
603 | |
604 | found: | |
74f75a0c DC |
605 | spin_unlock(&pag->pag_buf_lock); |
606 | xfs_perag_put(pag); | |
1da177e4 | 607 | |
0c842ad4 CH |
608 | if (!xfs_buf_trylock(bp)) { |
609 | if (flags & XBF_TRYLOCK) { | |
ce8e922c | 610 | xfs_buf_rele(bp); |
ff6d6af2 | 611 | XFS_STATS_INC(btp->bt_mount, xb_busy_locked); |
ce8e922c | 612 | return NULL; |
1da177e4 | 613 | } |
0c842ad4 | 614 | xfs_buf_lock(bp); |
ff6d6af2 | 615 | XFS_STATS_INC(btp->bt_mount, xb_get_locked_waited); |
1da177e4 LT |
616 | } |
617 | ||
0e6e847f DC |
618 | /* |
619 | * if the buffer is stale, clear all the external state associated with | |
620 | * it. We need to keep flags such as how we allocated the buffer memory | |
621 | * intact here. | |
622 | */ | |
ce8e922c NS |
623 | if (bp->b_flags & XBF_STALE) { |
624 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
cfb02852 | 625 | ASSERT(bp->b_iodone == NULL); |
611c9946 | 626 | bp->b_flags &= _XBF_KMEM | _XBF_PAGES; |
1813dd64 | 627 | bp->b_ops = NULL; |
2f926587 | 628 | } |
0b1b213f CH |
629 | |
630 | trace_xfs_buf_find(bp, flags, _RET_IP_); | |
ff6d6af2 | 631 | XFS_STATS_INC(btp->bt_mount, xb_get_locked); |
ce8e922c | 632 | return bp; |
1da177e4 LT |
633 | } |
634 | ||
635 | /* | |
3815832a DC |
636 | * Assembles a buffer covering the specified range. The code is optimised for |
637 | * cache hits, as metadata intensive workloads will see 3 orders of magnitude | |
638 | * more hits than misses. | |
1da177e4 | 639 | */ |
3815832a | 640 | struct xfs_buf * |
6dde2707 DC |
641 | xfs_buf_get_map( |
642 | struct xfs_buftarg *target, | |
643 | struct xfs_buf_map *map, | |
644 | int nmaps, | |
ce8e922c | 645 | xfs_buf_flags_t flags) |
1da177e4 | 646 | { |
3815832a DC |
647 | struct xfs_buf *bp; |
648 | struct xfs_buf *new_bp; | |
0e6e847f | 649 | int error = 0; |
1da177e4 | 650 | |
6dde2707 | 651 | bp = _xfs_buf_find(target, map, nmaps, flags, NULL); |
3815832a DC |
652 | if (likely(bp)) |
653 | goto found; | |
654 | ||
6dde2707 | 655 | new_bp = _xfs_buf_alloc(target, map, nmaps, flags); |
ce8e922c | 656 | if (unlikely(!new_bp)) |
1da177e4 LT |
657 | return NULL; |
658 | ||
fe2429b0 DC |
659 | error = xfs_buf_allocate_memory(new_bp, flags); |
660 | if (error) { | |
3e85c868 | 661 | xfs_buf_free(new_bp); |
fe2429b0 DC |
662 | return NULL; |
663 | } | |
664 | ||
6dde2707 | 665 | bp = _xfs_buf_find(target, map, nmaps, flags, new_bp); |
3815832a | 666 | if (!bp) { |
fe2429b0 | 667 | xfs_buf_free(new_bp); |
3815832a DC |
668 | return NULL; |
669 | } | |
670 | ||
fe2429b0 DC |
671 | if (bp != new_bp) |
672 | xfs_buf_free(new_bp); | |
1da177e4 | 673 | |
3815832a | 674 | found: |
611c9946 | 675 | if (!bp->b_addr) { |
ce8e922c | 676 | error = _xfs_buf_map_pages(bp, flags); |
1da177e4 | 677 | if (unlikely(error)) { |
4f10700a | 678 | xfs_warn(target->bt_mount, |
08e96e1a | 679 | "%s: failed to map pagesn", __func__); |
a8acad70 DC |
680 | xfs_buf_relse(bp); |
681 | return NULL; | |
1da177e4 LT |
682 | } |
683 | } | |
684 | ||
b79f4a1c DC |
685 | /* |
686 | * Clear b_error if this is a lookup from a caller that doesn't expect | |
687 | * valid data to be found in the buffer. | |
688 | */ | |
689 | if (!(flags & XBF_READ)) | |
690 | xfs_buf_ioerror(bp, 0); | |
691 | ||
ff6d6af2 | 692 | XFS_STATS_INC(target->bt_mount, xb_get); |
0b1b213f | 693 | trace_xfs_buf_get(bp, flags, _RET_IP_); |
ce8e922c | 694 | return bp; |
1da177e4 LT |
695 | } |
696 | ||
5d765b97 CH |
697 | STATIC int |
698 | _xfs_buf_read( | |
699 | xfs_buf_t *bp, | |
700 | xfs_buf_flags_t flags) | |
701 | { | |
43ff2122 | 702 | ASSERT(!(flags & XBF_WRITE)); |
f4b42421 | 703 | ASSERT(bp->b_maps[0].bm_bn != XFS_BUF_DADDR_NULL); |
5d765b97 | 704 | |
43ff2122 | 705 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD); |
1d5ae5df | 706 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD); |
5d765b97 | 707 | |
595bff75 DC |
708 | if (flags & XBF_ASYNC) { |
709 | xfs_buf_submit(bp); | |
0e95f19a | 710 | return 0; |
595bff75 DC |
711 | } |
712 | return xfs_buf_submit_wait(bp); | |
5d765b97 CH |
713 | } |
714 | ||
1da177e4 | 715 | xfs_buf_t * |
6dde2707 DC |
716 | xfs_buf_read_map( |
717 | struct xfs_buftarg *target, | |
718 | struct xfs_buf_map *map, | |
719 | int nmaps, | |
c3f8fc73 | 720 | xfs_buf_flags_t flags, |
1813dd64 | 721 | const struct xfs_buf_ops *ops) |
1da177e4 | 722 | { |
6dde2707 | 723 | struct xfs_buf *bp; |
ce8e922c NS |
724 | |
725 | flags |= XBF_READ; | |
726 | ||
6dde2707 | 727 | bp = xfs_buf_get_map(target, map, nmaps, flags); |
ce8e922c | 728 | if (bp) { |
0b1b213f CH |
729 | trace_xfs_buf_read(bp, flags, _RET_IP_); |
730 | ||
b0388bf1 | 731 | if (!(bp->b_flags & XBF_DONE)) { |
ff6d6af2 | 732 | XFS_STATS_INC(target->bt_mount, xb_get_read); |
1813dd64 | 733 | bp->b_ops = ops; |
5d765b97 | 734 | _xfs_buf_read(bp, flags); |
ce8e922c | 735 | } else if (flags & XBF_ASYNC) { |
1da177e4 LT |
736 | /* |
737 | * Read ahead call which is already satisfied, | |
738 | * drop the buffer | |
739 | */ | |
a8acad70 DC |
740 | xfs_buf_relse(bp); |
741 | return NULL; | |
1da177e4 | 742 | } else { |
1da177e4 | 743 | /* We do not want read in the flags */ |
ce8e922c | 744 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
745 | } |
746 | } | |
747 | ||
ce8e922c | 748 | return bp; |
1da177e4 LT |
749 | } |
750 | ||
1da177e4 | 751 | /* |
ce8e922c NS |
752 | * If we are not low on memory then do the readahead in a deadlock |
753 | * safe manner. | |
1da177e4 LT |
754 | */ |
755 | void | |
6dde2707 DC |
756 | xfs_buf_readahead_map( |
757 | struct xfs_buftarg *target, | |
758 | struct xfs_buf_map *map, | |
c3f8fc73 | 759 | int nmaps, |
1813dd64 | 760 | const struct xfs_buf_ops *ops) |
1da177e4 | 761 | { |
efa7c9f9 | 762 | if (bdi_read_congested(target->bt_bdev->bd_bdi)) |
1da177e4 LT |
763 | return; |
764 | ||
6dde2707 | 765 | xfs_buf_read_map(target, map, nmaps, |
1813dd64 | 766 | XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD, ops); |
1da177e4 LT |
767 | } |
768 | ||
5adc94c2 DC |
769 | /* |
770 | * Read an uncached buffer from disk. Allocates and returns a locked | |
771 | * buffer containing the disk contents or nothing. | |
772 | */ | |
ba372674 | 773 | int |
5adc94c2 | 774 | xfs_buf_read_uncached( |
5adc94c2 DC |
775 | struct xfs_buftarg *target, |
776 | xfs_daddr_t daddr, | |
e70b73f8 | 777 | size_t numblks, |
c3f8fc73 | 778 | int flags, |
ba372674 | 779 | struct xfs_buf **bpp, |
1813dd64 | 780 | const struct xfs_buf_ops *ops) |
5adc94c2 | 781 | { |
eab4e633 | 782 | struct xfs_buf *bp; |
5adc94c2 | 783 | |
ba372674 DC |
784 | *bpp = NULL; |
785 | ||
e70b73f8 | 786 | bp = xfs_buf_get_uncached(target, numblks, flags); |
5adc94c2 | 787 | if (!bp) |
ba372674 | 788 | return -ENOMEM; |
5adc94c2 DC |
789 | |
790 | /* set up the buffer for a read IO */ | |
3e85c868 | 791 | ASSERT(bp->b_map_count == 1); |
ba372674 | 792 | bp->b_bn = XFS_BUF_DADDR_NULL; /* always null for uncached buffers */ |
3e85c868 | 793 | bp->b_maps[0].bm_bn = daddr; |
cbb7baab | 794 | bp->b_flags |= XBF_READ; |
1813dd64 | 795 | bp->b_ops = ops; |
5adc94c2 | 796 | |
595bff75 | 797 | xfs_buf_submit_wait(bp); |
ba372674 DC |
798 | if (bp->b_error) { |
799 | int error = bp->b_error; | |
83a0adc3 | 800 | xfs_buf_relse(bp); |
ba372674 | 801 | return error; |
83a0adc3 | 802 | } |
ba372674 DC |
803 | |
804 | *bpp = bp; | |
805 | return 0; | |
1da177e4 LT |
806 | } |
807 | ||
44396476 DC |
808 | /* |
809 | * Return a buffer allocated as an empty buffer and associated to external | |
810 | * memory via xfs_buf_associate_memory() back to it's empty state. | |
811 | */ | |
812 | void | |
813 | xfs_buf_set_empty( | |
814 | struct xfs_buf *bp, | |
e70b73f8 | 815 | size_t numblks) |
44396476 DC |
816 | { |
817 | if (bp->b_pages) | |
818 | _xfs_buf_free_pages(bp); | |
819 | ||
820 | bp->b_pages = NULL; | |
821 | bp->b_page_count = 0; | |
822 | bp->b_addr = NULL; | |
4e94b71b | 823 | bp->b_length = numblks; |
aa0e8833 | 824 | bp->b_io_length = numblks; |
3e85c868 DC |
825 | |
826 | ASSERT(bp->b_map_count == 1); | |
44396476 | 827 | bp->b_bn = XFS_BUF_DADDR_NULL; |
3e85c868 DC |
828 | bp->b_maps[0].bm_bn = XFS_BUF_DADDR_NULL; |
829 | bp->b_maps[0].bm_len = bp->b_length; | |
44396476 DC |
830 | } |
831 | ||
1da177e4 LT |
832 | static inline struct page * |
833 | mem_to_page( | |
834 | void *addr) | |
835 | { | |
9e2779fa | 836 | if ((!is_vmalloc_addr(addr))) { |
1da177e4 LT |
837 | return virt_to_page(addr); |
838 | } else { | |
839 | return vmalloc_to_page(addr); | |
840 | } | |
841 | } | |
842 | ||
843 | int | |
ce8e922c NS |
844 | xfs_buf_associate_memory( |
845 | xfs_buf_t *bp, | |
1da177e4 LT |
846 | void *mem, |
847 | size_t len) | |
848 | { | |
849 | int rval; | |
850 | int i = 0; | |
d1afb678 LM |
851 | unsigned long pageaddr; |
852 | unsigned long offset; | |
853 | size_t buflen; | |
1da177e4 LT |
854 | int page_count; |
855 | ||
0e6e847f | 856 | pageaddr = (unsigned long)mem & PAGE_MASK; |
d1afb678 | 857 | offset = (unsigned long)mem - pageaddr; |
0e6e847f DC |
858 | buflen = PAGE_ALIGN(len + offset); |
859 | page_count = buflen >> PAGE_SHIFT; | |
1da177e4 LT |
860 | |
861 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
862 | if (bp->b_pages) |
863 | _xfs_buf_free_pages(bp); | |
1da177e4 | 864 | |
ce8e922c NS |
865 | bp->b_pages = NULL; |
866 | bp->b_addr = mem; | |
1da177e4 | 867 | |
87937bf8 | 868 | rval = _xfs_buf_get_pages(bp, page_count); |
1da177e4 LT |
869 | if (rval) |
870 | return rval; | |
871 | ||
ce8e922c | 872 | bp->b_offset = offset; |
d1afb678 LM |
873 | |
874 | for (i = 0; i < bp->b_page_count; i++) { | |
875 | bp->b_pages[i] = mem_to_page((void *)pageaddr); | |
0e6e847f | 876 | pageaddr += PAGE_SIZE; |
1da177e4 | 877 | } |
1da177e4 | 878 | |
aa0e8833 | 879 | bp->b_io_length = BTOBB(len); |
4e94b71b | 880 | bp->b_length = BTOBB(buflen); |
1da177e4 LT |
881 | |
882 | return 0; | |
883 | } | |
884 | ||
885 | xfs_buf_t * | |
686865f7 DC |
886 | xfs_buf_get_uncached( |
887 | struct xfs_buftarg *target, | |
e70b73f8 | 888 | size_t numblks, |
686865f7 | 889 | int flags) |
1da177e4 | 890 | { |
e70b73f8 | 891 | unsigned long page_count; |
1fa40b01 | 892 | int error, i; |
3e85c868 DC |
893 | struct xfs_buf *bp; |
894 | DEFINE_SINGLE_BUF_MAP(map, XFS_BUF_DADDR_NULL, numblks); | |
1da177e4 | 895 | |
c891c30a BF |
896 | /* flags might contain irrelevant bits, pass only what we care about */ |
897 | bp = _xfs_buf_alloc(target, &map, 1, flags & XBF_NO_IOACCT); | |
1da177e4 LT |
898 | if (unlikely(bp == NULL)) |
899 | goto fail; | |
1da177e4 | 900 | |
e70b73f8 | 901 | page_count = PAGE_ALIGN(numblks << BBSHIFT) >> PAGE_SHIFT; |
87937bf8 | 902 | error = _xfs_buf_get_pages(bp, page_count); |
1fa40b01 | 903 | if (error) |
1da177e4 LT |
904 | goto fail_free_buf; |
905 | ||
1fa40b01 | 906 | for (i = 0; i < page_count; i++) { |
686865f7 | 907 | bp->b_pages[i] = alloc_page(xb_to_gfp(flags)); |
1fa40b01 CH |
908 | if (!bp->b_pages[i]) |
909 | goto fail_free_mem; | |
1da177e4 | 910 | } |
1fa40b01 | 911 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 912 | |
611c9946 | 913 | error = _xfs_buf_map_pages(bp, 0); |
1fa40b01 | 914 | if (unlikely(error)) { |
4f10700a | 915 | xfs_warn(target->bt_mount, |
08e96e1a | 916 | "%s: failed to map pages", __func__); |
1da177e4 | 917 | goto fail_free_mem; |
1fa40b01 | 918 | } |
1da177e4 | 919 | |
686865f7 | 920 | trace_xfs_buf_get_uncached(bp, _RET_IP_); |
1da177e4 | 921 | return bp; |
1fa40b01 | 922 | |
1da177e4 | 923 | fail_free_mem: |
1fa40b01 CH |
924 | while (--i >= 0) |
925 | __free_page(bp->b_pages[i]); | |
ca165b88 | 926 | _xfs_buf_free_pages(bp); |
1da177e4 | 927 | fail_free_buf: |
3e85c868 | 928 | xfs_buf_free_maps(bp); |
4347b9d7 | 929 | kmem_zone_free(xfs_buf_zone, bp); |
1da177e4 LT |
930 | fail: |
931 | return NULL; | |
932 | } | |
933 | ||
934 | /* | |
1da177e4 LT |
935 | * Increment reference count on buffer, to hold the buffer concurrently |
936 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
937 | * Must hold the buffer already to call this function. |
938 | */ | |
939 | void | |
ce8e922c NS |
940 | xfs_buf_hold( |
941 | xfs_buf_t *bp) | |
1da177e4 | 942 | { |
0b1b213f | 943 | trace_xfs_buf_hold(bp, _RET_IP_); |
ce8e922c | 944 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
945 | } |
946 | ||
947 | /* | |
9c7504aa BF |
948 | * Release a hold on the specified buffer. If the hold count is 1, the buffer is |
949 | * placed on LRU or freed (depending on b_lru_ref). | |
1da177e4 LT |
950 | */ |
951 | void | |
ce8e922c NS |
952 | xfs_buf_rele( |
953 | xfs_buf_t *bp) | |
1da177e4 | 954 | { |
74f75a0c | 955 | struct xfs_perag *pag = bp->b_pag; |
9c7504aa BF |
956 | bool release; |
957 | bool freebuf = false; | |
1da177e4 | 958 | |
0b1b213f | 959 | trace_xfs_buf_rele(bp, _RET_IP_); |
1da177e4 | 960 | |
74f75a0c | 961 | if (!pag) { |
430cbeb8 | 962 | ASSERT(list_empty(&bp->b_lru)); |
9c7504aa BF |
963 | if (atomic_dec_and_test(&bp->b_hold)) { |
964 | xfs_buf_ioacct_dec(bp); | |
fad3aa1e | 965 | xfs_buf_free(bp); |
9c7504aa | 966 | } |
fad3aa1e NS |
967 | return; |
968 | } | |
969 | ||
3790689f | 970 | ASSERT(atomic_read(&bp->b_hold) > 0); |
a4082357 | 971 | |
9c7504aa BF |
972 | release = atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock); |
973 | spin_lock(&bp->b_lock); | |
974 | if (!release) { | |
975 | /* | |
976 | * Drop the in-flight state if the buffer is already on the LRU | |
977 | * and it holds the only reference. This is racy because we | |
978 | * haven't acquired the pag lock, but the use of _XBF_IN_FLIGHT | |
979 | * ensures the decrement occurs only once per-buf. | |
980 | */ | |
981 | if ((atomic_read(&bp->b_hold) == 1) && !list_empty(&bp->b_lru)) | |
982 | xfs_buf_ioacct_dec(bp); | |
983 | goto out_unlock; | |
984 | } | |
985 | ||
986 | /* the last reference has been dropped ... */ | |
987 | xfs_buf_ioacct_dec(bp); | |
988 | if (!(bp->b_flags & XBF_STALE) && atomic_read(&bp->b_lru_ref)) { | |
989 | /* | |
990 | * If the buffer is added to the LRU take a new reference to the | |
991 | * buffer for the LRU and clear the (now stale) dispose list | |
992 | * state flag | |
993 | */ | |
994 | if (list_lru_add(&bp->b_target->bt_lru, &bp->b_lru)) { | |
995 | bp->b_state &= ~XFS_BSTATE_DISPOSE; | |
996 | atomic_inc(&bp->b_hold); | |
1da177e4 | 997 | } |
9c7504aa BF |
998 | spin_unlock(&pag->pag_buf_lock); |
999 | } else { | |
1000 | /* | |
1001 | * most of the time buffers will already be removed from the | |
1002 | * LRU, so optimise that case by checking for the | |
1003 | * XFS_BSTATE_DISPOSE flag indicating the last list the buffer | |
1004 | * was on was the disposal list | |
1005 | */ | |
1006 | if (!(bp->b_state & XFS_BSTATE_DISPOSE)) { | |
1007 | list_lru_del(&bp->b_target->bt_lru, &bp->b_lru); | |
1008 | } else { | |
1009 | ASSERT(list_empty(&bp->b_lru)); | |
1da177e4 | 1010 | } |
9c7504aa BF |
1011 | |
1012 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); | |
6031e73a LS |
1013 | rhashtable_remove_fast(&pag->pag_buf_hash, &bp->b_rhash_head, |
1014 | xfs_buf_hash_params); | |
9c7504aa BF |
1015 | spin_unlock(&pag->pag_buf_lock); |
1016 | xfs_perag_put(pag); | |
1017 | freebuf = true; | |
1da177e4 | 1018 | } |
9c7504aa BF |
1019 | |
1020 | out_unlock: | |
1021 | spin_unlock(&bp->b_lock); | |
1022 | ||
1023 | if (freebuf) | |
1024 | xfs_buf_free(bp); | |
1da177e4 LT |
1025 | } |
1026 | ||
1027 | ||
1028 | /* | |
0e6e847f | 1029 | * Lock a buffer object, if it is not already locked. |
90810b9e DC |
1030 | * |
1031 | * If we come across a stale, pinned, locked buffer, we know that we are | |
1032 | * being asked to lock a buffer that has been reallocated. Because it is | |
1033 | * pinned, we know that the log has not been pushed to disk and hence it | |
1034 | * will still be locked. Rather than continuing to have trylock attempts | |
1035 | * fail until someone else pushes the log, push it ourselves before | |
1036 | * returning. This means that the xfsaild will not get stuck trying | |
1037 | * to push on stale inode buffers. | |
1da177e4 LT |
1038 | */ |
1039 | int | |
0c842ad4 CH |
1040 | xfs_buf_trylock( |
1041 | struct xfs_buf *bp) | |
1da177e4 LT |
1042 | { |
1043 | int locked; | |
1044 | ||
ce8e922c | 1045 | locked = down_trylock(&bp->b_sema) == 0; |
479c6412 | 1046 | if (locked) { |
ce8e922c | 1047 | XB_SET_OWNER(bp); |
479c6412 DW |
1048 | trace_xfs_buf_trylock(bp, _RET_IP_); |
1049 | } else { | |
1050 | trace_xfs_buf_trylock_fail(bp, _RET_IP_); | |
1051 | } | |
0c842ad4 | 1052 | return locked; |
1da177e4 | 1053 | } |
1da177e4 LT |
1054 | |
1055 | /* | |
0e6e847f | 1056 | * Lock a buffer object. |
ed3b4d6c DC |
1057 | * |
1058 | * If we come across a stale, pinned, locked buffer, we know that we | |
1059 | * are being asked to lock a buffer that has been reallocated. Because | |
1060 | * it is pinned, we know that the log has not been pushed to disk and | |
1061 | * hence it will still be locked. Rather than sleeping until someone | |
1062 | * else pushes the log, push it ourselves before trying to get the lock. | |
1da177e4 | 1063 | */ |
ce8e922c NS |
1064 | void |
1065 | xfs_buf_lock( | |
0c842ad4 | 1066 | struct xfs_buf *bp) |
1da177e4 | 1067 | { |
0b1b213f CH |
1068 | trace_xfs_buf_lock(bp, _RET_IP_); |
1069 | ||
ed3b4d6c | 1070 | if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
ebad861b | 1071 | xfs_log_force(bp->b_target->bt_mount, 0); |
ce8e922c NS |
1072 | down(&bp->b_sema); |
1073 | XB_SET_OWNER(bp); | |
0b1b213f CH |
1074 | |
1075 | trace_xfs_buf_lock_done(bp, _RET_IP_); | |
1da177e4 LT |
1076 | } |
1077 | ||
1da177e4 | 1078 | void |
ce8e922c | 1079 | xfs_buf_unlock( |
0c842ad4 | 1080 | struct xfs_buf *bp) |
1da177e4 | 1081 | { |
ce8e922c NS |
1082 | XB_CLEAR_OWNER(bp); |
1083 | up(&bp->b_sema); | |
0b1b213f CH |
1084 | |
1085 | trace_xfs_buf_unlock(bp, _RET_IP_); | |
1da177e4 LT |
1086 | } |
1087 | ||
ce8e922c NS |
1088 | STATIC void |
1089 | xfs_buf_wait_unpin( | |
1090 | xfs_buf_t *bp) | |
1da177e4 LT |
1091 | { |
1092 | DECLARE_WAITQUEUE (wait, current); | |
1093 | ||
ce8e922c | 1094 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
1095 | return; |
1096 | ||
ce8e922c | 1097 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1098 | for (;;) { |
1099 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 1100 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 1101 | break; |
7eaceacc | 1102 | io_schedule(); |
1da177e4 | 1103 | } |
ce8e922c | 1104 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1105 | set_current_state(TASK_RUNNING); |
1106 | } | |
1107 | ||
1108 | /* | |
1109 | * Buffer Utility Routines | |
1110 | */ | |
1111 | ||
e8aaba9a DC |
1112 | void |
1113 | xfs_buf_ioend( | |
1114 | struct xfs_buf *bp) | |
1da177e4 | 1115 | { |
e8aaba9a DC |
1116 | bool read = bp->b_flags & XBF_READ; |
1117 | ||
1118 | trace_xfs_buf_iodone(bp, _RET_IP_); | |
1813dd64 DC |
1119 | |
1120 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); | |
d5929de8 | 1121 | |
61be9c52 DC |
1122 | /* |
1123 | * Pull in IO completion errors now. We are guaranteed to be running | |
1124 | * single threaded, so we don't need the lock to read b_io_error. | |
1125 | */ | |
1126 | if (!bp->b_error && bp->b_io_error) | |
1127 | xfs_buf_ioerror(bp, bp->b_io_error); | |
1128 | ||
e8aaba9a DC |
1129 | /* Only validate buffers that were read without errors */ |
1130 | if (read && !bp->b_error && bp->b_ops) { | |
1131 | ASSERT(!bp->b_iodone); | |
1813dd64 | 1132 | bp->b_ops->verify_read(bp); |
e8aaba9a DC |
1133 | } |
1134 | ||
1135 | if (!bp->b_error) | |
1136 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1137 | |
80f6c29d | 1138 | if (bp->b_iodone) |
ce8e922c NS |
1139 | (*(bp->b_iodone))(bp); |
1140 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 | 1141 | xfs_buf_relse(bp); |
595bff75 | 1142 | else |
1813dd64 | 1143 | complete(&bp->b_iowait); |
1da177e4 LT |
1144 | } |
1145 | ||
e8aaba9a DC |
1146 | static void |
1147 | xfs_buf_ioend_work( | |
1148 | struct work_struct *work) | |
1da177e4 | 1149 | { |
e8aaba9a | 1150 | struct xfs_buf *bp = |
b29c70f5 | 1151 | container_of(work, xfs_buf_t, b_ioend_work); |
0b1b213f | 1152 | |
e8aaba9a DC |
1153 | xfs_buf_ioend(bp); |
1154 | } | |
1da177e4 | 1155 | |
211fe1a4 | 1156 | static void |
e8aaba9a DC |
1157 | xfs_buf_ioend_async( |
1158 | struct xfs_buf *bp) | |
1159 | { | |
b29c70f5 BF |
1160 | INIT_WORK(&bp->b_ioend_work, xfs_buf_ioend_work); |
1161 | queue_work(bp->b_ioend_wq, &bp->b_ioend_work); | |
1da177e4 LT |
1162 | } |
1163 | ||
1da177e4 | 1164 | void |
ce8e922c NS |
1165 | xfs_buf_ioerror( |
1166 | xfs_buf_t *bp, | |
1167 | int error) | |
1da177e4 | 1168 | { |
2451337d DC |
1169 | ASSERT(error <= 0 && error >= -1000); |
1170 | bp->b_error = error; | |
0b1b213f | 1171 | trace_xfs_buf_ioerror(bp, error, _RET_IP_); |
1da177e4 LT |
1172 | } |
1173 | ||
901796af CH |
1174 | void |
1175 | xfs_buf_ioerror_alert( | |
1176 | struct xfs_buf *bp, | |
1177 | const char *func) | |
1178 | { | |
1179 | xfs_alert(bp->b_target->bt_mount, | |
aa0e8833 | 1180 | "metadata I/O error: block 0x%llx (\"%s\") error %d numblks %d", |
2451337d | 1181 | (__uint64_t)XFS_BUF_ADDR(bp), func, -bp->b_error, bp->b_length); |
901796af CH |
1182 | } |
1183 | ||
a2dcf5df CH |
1184 | int |
1185 | xfs_bwrite( | |
1186 | struct xfs_buf *bp) | |
1187 | { | |
1188 | int error; | |
1189 | ||
1190 | ASSERT(xfs_buf_islocked(bp)); | |
1191 | ||
1192 | bp->b_flags |= XBF_WRITE; | |
27187754 DC |
1193 | bp->b_flags &= ~(XBF_ASYNC | XBF_READ | _XBF_DELWRI_Q | |
1194 | XBF_WRITE_FAIL | XBF_DONE); | |
a2dcf5df | 1195 | |
595bff75 | 1196 | error = xfs_buf_submit_wait(bp); |
a2dcf5df CH |
1197 | if (error) { |
1198 | xfs_force_shutdown(bp->b_target->bt_mount, | |
1199 | SHUTDOWN_META_IO_ERROR); | |
1200 | } | |
1201 | return error; | |
1202 | } | |
1203 | ||
9bdd9bd6 | 1204 | static void |
ce8e922c | 1205 | xfs_buf_bio_end_io( |
4246a0b6 | 1206 | struct bio *bio) |
1da177e4 | 1207 | { |
9bdd9bd6 | 1208 | struct xfs_buf *bp = (struct xfs_buf *)bio->bi_private; |
1da177e4 | 1209 | |
37eb17e6 DC |
1210 | /* |
1211 | * don't overwrite existing errors - otherwise we can lose errors on | |
1212 | * buffers that require multiple bios to complete. | |
1213 | */ | |
9bdd9bd6 BF |
1214 | if (bio->bi_error) |
1215 | cmpxchg(&bp->b_io_error, 0, bio->bi_error); | |
1da177e4 | 1216 | |
37eb17e6 | 1217 | if (!bp->b_error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ)) |
73c77e2c JB |
1218 | invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp)); |
1219 | ||
e8aaba9a DC |
1220 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) |
1221 | xfs_buf_ioend_async(bp); | |
1da177e4 | 1222 | bio_put(bio); |
1da177e4 LT |
1223 | } |
1224 | ||
3e85c868 DC |
1225 | static void |
1226 | xfs_buf_ioapply_map( | |
1227 | struct xfs_buf *bp, | |
1228 | int map, | |
1229 | int *buf_offset, | |
1230 | int *count, | |
50bfcd0c MC |
1231 | int op, |
1232 | int op_flags) | |
1da177e4 | 1233 | { |
3e85c868 DC |
1234 | int page_index; |
1235 | int total_nr_pages = bp->b_page_count; | |
1236 | int nr_pages; | |
1237 | struct bio *bio; | |
1238 | sector_t sector = bp->b_maps[map].bm_bn; | |
1239 | int size; | |
1240 | int offset; | |
1da177e4 | 1241 | |
ce8e922c | 1242 | total_nr_pages = bp->b_page_count; |
1da177e4 | 1243 | |
3e85c868 DC |
1244 | /* skip the pages in the buffer before the start offset */ |
1245 | page_index = 0; | |
1246 | offset = *buf_offset; | |
1247 | while (offset >= PAGE_SIZE) { | |
1248 | page_index++; | |
1249 | offset -= PAGE_SIZE; | |
f538d4da CH |
1250 | } |
1251 | ||
3e85c868 DC |
1252 | /* |
1253 | * Limit the IO size to the length of the current vector, and update the | |
1254 | * remaining IO count for the next time around. | |
1255 | */ | |
1256 | size = min_t(int, BBTOB(bp->b_maps[map].bm_len), *count); | |
1257 | *count -= size; | |
1258 | *buf_offset += size; | |
34951f5c | 1259 | |
1da177e4 | 1260 | next_chunk: |
ce8e922c | 1261 | atomic_inc(&bp->b_io_remaining); |
c908e380 | 1262 | nr_pages = min(total_nr_pages, BIO_MAX_PAGES); |
1da177e4 LT |
1263 | |
1264 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1265 | bio->bi_bdev = bp->b_target->bt_bdev; |
4f024f37 | 1266 | bio->bi_iter.bi_sector = sector; |
ce8e922c NS |
1267 | bio->bi_end_io = xfs_buf_bio_end_io; |
1268 | bio->bi_private = bp; | |
50bfcd0c | 1269 | bio_set_op_attrs(bio, op, op_flags); |
0e6e847f | 1270 | |
3e85c868 | 1271 | for (; size && nr_pages; nr_pages--, page_index++) { |
0e6e847f | 1272 | int rbytes, nbytes = PAGE_SIZE - offset; |
1da177e4 LT |
1273 | |
1274 | if (nbytes > size) | |
1275 | nbytes = size; | |
1276 | ||
3e85c868 DC |
1277 | rbytes = bio_add_page(bio, bp->b_pages[page_index], nbytes, |
1278 | offset); | |
ce8e922c | 1279 | if (rbytes < nbytes) |
1da177e4 LT |
1280 | break; |
1281 | ||
1282 | offset = 0; | |
aa0e8833 | 1283 | sector += BTOBB(nbytes); |
1da177e4 LT |
1284 | size -= nbytes; |
1285 | total_nr_pages--; | |
1286 | } | |
1287 | ||
4f024f37 | 1288 | if (likely(bio->bi_iter.bi_size)) { |
73c77e2c JB |
1289 | if (xfs_buf_is_vmapped(bp)) { |
1290 | flush_kernel_vmap_range(bp->b_addr, | |
1291 | xfs_buf_vmap_len(bp)); | |
1292 | } | |
4e49ea4a | 1293 | submit_bio(bio); |
1da177e4 LT |
1294 | if (size) |
1295 | goto next_chunk; | |
1296 | } else { | |
37eb17e6 DC |
1297 | /* |
1298 | * This is guaranteed not to be the last io reference count | |
595bff75 | 1299 | * because the caller (xfs_buf_submit) holds a count itself. |
37eb17e6 DC |
1300 | */ |
1301 | atomic_dec(&bp->b_io_remaining); | |
2451337d | 1302 | xfs_buf_ioerror(bp, -EIO); |
ec53d1db | 1303 | bio_put(bio); |
1da177e4 | 1304 | } |
3e85c868 DC |
1305 | |
1306 | } | |
1307 | ||
1308 | STATIC void | |
1309 | _xfs_buf_ioapply( | |
1310 | struct xfs_buf *bp) | |
1311 | { | |
1312 | struct blk_plug plug; | |
50bfcd0c MC |
1313 | int op; |
1314 | int op_flags = 0; | |
3e85c868 DC |
1315 | int offset; |
1316 | int size; | |
1317 | int i; | |
1318 | ||
c163f9a1 DC |
1319 | /* |
1320 | * Make sure we capture only current IO errors rather than stale errors | |
1321 | * left over from previous use of the buffer (e.g. failed readahead). | |
1322 | */ | |
1323 | bp->b_error = 0; | |
1324 | ||
b29c70f5 BF |
1325 | /* |
1326 | * Initialize the I/O completion workqueue if we haven't yet or the | |
1327 | * submitter has not opted to specify a custom one. | |
1328 | */ | |
1329 | if (!bp->b_ioend_wq) | |
1330 | bp->b_ioend_wq = bp->b_target->bt_mount->m_buf_workqueue; | |
1331 | ||
3e85c868 | 1332 | if (bp->b_flags & XBF_WRITE) { |
50bfcd0c | 1333 | op = REQ_OP_WRITE; |
3e85c868 | 1334 | if (bp->b_flags & XBF_SYNCIO) |
70fd7614 | 1335 | op_flags = REQ_SYNC; |
3e85c868 | 1336 | if (bp->b_flags & XBF_FUA) |
50bfcd0c | 1337 | op_flags |= REQ_FUA; |
3e85c868 | 1338 | if (bp->b_flags & XBF_FLUSH) |
28a8f0d3 | 1339 | op_flags |= REQ_PREFLUSH; |
1813dd64 DC |
1340 | |
1341 | /* | |
1342 | * Run the write verifier callback function if it exists. If | |
1343 | * this function fails it will mark the buffer with an error and | |
1344 | * the IO should not be dispatched. | |
1345 | */ | |
1346 | if (bp->b_ops) { | |
1347 | bp->b_ops->verify_write(bp); | |
1348 | if (bp->b_error) { | |
1349 | xfs_force_shutdown(bp->b_target->bt_mount, | |
1350 | SHUTDOWN_CORRUPT_INCORE); | |
1351 | return; | |
1352 | } | |
400b9d88 DC |
1353 | } else if (bp->b_bn != XFS_BUF_DADDR_NULL) { |
1354 | struct xfs_mount *mp = bp->b_target->bt_mount; | |
1355 | ||
1356 | /* | |
1357 | * non-crc filesystems don't attach verifiers during | |
1358 | * log recovery, so don't warn for such filesystems. | |
1359 | */ | |
1360 | if (xfs_sb_version_hascrc(&mp->m_sb)) { | |
1361 | xfs_warn(mp, | |
1362 | "%s: no ops on block 0x%llx/0x%x", | |
1363 | __func__, bp->b_bn, bp->b_length); | |
1364 | xfs_hex_dump(bp->b_addr, 64); | |
1365 | dump_stack(); | |
1366 | } | |
1813dd64 | 1367 | } |
3e85c868 | 1368 | } else if (bp->b_flags & XBF_READ_AHEAD) { |
50bfcd0c MC |
1369 | op = REQ_OP_READ; |
1370 | op_flags = REQ_RAHEAD; | |
3e85c868 | 1371 | } else { |
50bfcd0c | 1372 | op = REQ_OP_READ; |
3e85c868 DC |
1373 | } |
1374 | ||
1375 | /* we only use the buffer cache for meta-data */ | |
50bfcd0c | 1376 | op_flags |= REQ_META; |
3e85c868 DC |
1377 | |
1378 | /* | |
1379 | * Walk all the vectors issuing IO on them. Set up the initial offset | |
1380 | * into the buffer and the desired IO size before we start - | |
1381 | * _xfs_buf_ioapply_vec() will modify them appropriately for each | |
1382 | * subsequent call. | |
1383 | */ | |
1384 | offset = bp->b_offset; | |
1385 | size = BBTOB(bp->b_io_length); | |
1386 | blk_start_plug(&plug); | |
1387 | for (i = 0; i < bp->b_map_count; i++) { | |
50bfcd0c | 1388 | xfs_buf_ioapply_map(bp, i, &offset, &size, op, op_flags); |
3e85c868 DC |
1389 | if (bp->b_error) |
1390 | break; | |
1391 | if (size <= 0) | |
1392 | break; /* all done */ | |
1393 | } | |
1394 | blk_finish_plug(&plug); | |
1da177e4 LT |
1395 | } |
1396 | ||
595bff75 DC |
1397 | /* |
1398 | * Asynchronous IO submission path. This transfers the buffer lock ownership and | |
1399 | * the current reference to the IO. It is not safe to reference the buffer after | |
1400 | * a call to this function unless the caller holds an additional reference | |
1401 | * itself. | |
1402 | */ | |
0e95f19a | 1403 | void |
595bff75 DC |
1404 | xfs_buf_submit( |
1405 | struct xfs_buf *bp) | |
1da177e4 | 1406 | { |
595bff75 | 1407 | trace_xfs_buf_submit(bp, _RET_IP_); |
1da177e4 | 1408 | |
43ff2122 | 1409 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); |
595bff75 DC |
1410 | ASSERT(bp->b_flags & XBF_ASYNC); |
1411 | ||
1412 | /* on shutdown we stale and complete the buffer immediately */ | |
1413 | if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) { | |
1414 | xfs_buf_ioerror(bp, -EIO); | |
1415 | bp->b_flags &= ~XBF_DONE; | |
1416 | xfs_buf_stale(bp); | |
1417 | xfs_buf_ioend(bp); | |
1418 | return; | |
1419 | } | |
1da177e4 | 1420 | |
375ec69d | 1421 | if (bp->b_flags & XBF_WRITE) |
ce8e922c | 1422 | xfs_buf_wait_unpin(bp); |
e11bb805 | 1423 | |
61be9c52 DC |
1424 | /* clear the internal error state to avoid spurious errors */ |
1425 | bp->b_io_error = 0; | |
1426 | ||
e11bb805 | 1427 | /* |
595bff75 DC |
1428 | * The caller's reference is released during I/O completion. |
1429 | * This occurs some time after the last b_io_remaining reference is | |
1430 | * released, so after we drop our Io reference we have to have some | |
1431 | * other reference to ensure the buffer doesn't go away from underneath | |
1432 | * us. Take a direct reference to ensure we have safe access to the | |
1433 | * buffer until we are finished with it. | |
e11bb805 | 1434 | */ |
ce8e922c | 1435 | xfs_buf_hold(bp); |
1da177e4 | 1436 | |
8d6c1210 | 1437 | /* |
e11bb805 DC |
1438 | * Set the count to 1 initially, this will stop an I/O completion |
1439 | * callout which happens before we have started all the I/O from calling | |
1440 | * xfs_buf_ioend too early. | |
1da177e4 | 1441 | */ |
ce8e922c | 1442 | atomic_set(&bp->b_io_remaining, 1); |
9c7504aa | 1443 | xfs_buf_ioacct_inc(bp); |
ce8e922c | 1444 | _xfs_buf_ioapply(bp); |
e11bb805 | 1445 | |
8d6c1210 | 1446 | /* |
595bff75 DC |
1447 | * If _xfs_buf_ioapply failed, we can get back here with only the IO |
1448 | * reference we took above. If we drop it to zero, run completion so | |
1449 | * that we don't return to the caller with completion still pending. | |
8d6c1210 | 1450 | */ |
e8aaba9a | 1451 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) { |
595bff75 | 1452 | if (bp->b_error) |
e8aaba9a DC |
1453 | xfs_buf_ioend(bp); |
1454 | else | |
1455 | xfs_buf_ioend_async(bp); | |
1456 | } | |
1da177e4 | 1457 | |
ce8e922c | 1458 | xfs_buf_rele(bp); |
595bff75 | 1459 | /* Note: it is not safe to reference bp now we've dropped our ref */ |
1da177e4 LT |
1460 | } |
1461 | ||
1462 | /* | |
595bff75 | 1463 | * Synchronous buffer IO submission path, read or write. |
1da177e4 LT |
1464 | */ |
1465 | int | |
595bff75 DC |
1466 | xfs_buf_submit_wait( |
1467 | struct xfs_buf *bp) | |
1da177e4 | 1468 | { |
595bff75 | 1469 | int error; |
0b1b213f | 1470 | |
595bff75 DC |
1471 | trace_xfs_buf_submit_wait(bp, _RET_IP_); |
1472 | ||
1473 | ASSERT(!(bp->b_flags & (_XBF_DELWRI_Q | XBF_ASYNC))); | |
0b1b213f | 1474 | |
595bff75 DC |
1475 | if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) { |
1476 | xfs_buf_ioerror(bp, -EIO); | |
1477 | xfs_buf_stale(bp); | |
1478 | bp->b_flags &= ~XBF_DONE; | |
1479 | return -EIO; | |
1480 | } | |
1481 | ||
1482 | if (bp->b_flags & XBF_WRITE) | |
1483 | xfs_buf_wait_unpin(bp); | |
1484 | ||
1485 | /* clear the internal error state to avoid spurious errors */ | |
1486 | bp->b_io_error = 0; | |
1487 | ||
1488 | /* | |
1489 | * For synchronous IO, the IO does not inherit the submitters reference | |
1490 | * count, nor the buffer lock. Hence we cannot release the reference we | |
1491 | * are about to take until we've waited for all IO completion to occur, | |
1492 | * including any xfs_buf_ioend_async() work that may be pending. | |
1493 | */ | |
1494 | xfs_buf_hold(bp); | |
1495 | ||
1496 | /* | |
1497 | * Set the count to 1 initially, this will stop an I/O completion | |
1498 | * callout which happens before we have started all the I/O from calling | |
1499 | * xfs_buf_ioend too early. | |
1500 | */ | |
1501 | atomic_set(&bp->b_io_remaining, 1); | |
1502 | _xfs_buf_ioapply(bp); | |
1503 | ||
1504 | /* | |
1505 | * make sure we run completion synchronously if it raced with us and is | |
1506 | * already complete. | |
1507 | */ | |
1508 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) | |
1509 | xfs_buf_ioend(bp); | |
0b1b213f | 1510 | |
595bff75 DC |
1511 | /* wait for completion before gathering the error from the buffer */ |
1512 | trace_xfs_buf_iowait(bp, _RET_IP_); | |
1513 | wait_for_completion(&bp->b_iowait); | |
0b1b213f | 1514 | trace_xfs_buf_iowait_done(bp, _RET_IP_); |
595bff75 DC |
1515 | error = bp->b_error; |
1516 | ||
1517 | /* | |
1518 | * all done now, we can release the hold that keeps the buffer | |
1519 | * referenced for the entire IO. | |
1520 | */ | |
1521 | xfs_buf_rele(bp); | |
1522 | return error; | |
1da177e4 LT |
1523 | } |
1524 | ||
88ee2df7 | 1525 | void * |
ce8e922c | 1526 | xfs_buf_offset( |
88ee2df7 | 1527 | struct xfs_buf *bp, |
1da177e4 LT |
1528 | size_t offset) |
1529 | { | |
1530 | struct page *page; | |
1531 | ||
611c9946 | 1532 | if (bp->b_addr) |
62926044 | 1533 | return bp->b_addr + offset; |
1da177e4 | 1534 | |
ce8e922c | 1535 | offset += bp->b_offset; |
0e6e847f | 1536 | page = bp->b_pages[offset >> PAGE_SHIFT]; |
88ee2df7 | 1537 | return page_address(page) + (offset & (PAGE_SIZE-1)); |
1da177e4 LT |
1538 | } |
1539 | ||
1540 | /* | |
1da177e4 LT |
1541 | * Move data into or out of a buffer. |
1542 | */ | |
1543 | void | |
ce8e922c NS |
1544 | xfs_buf_iomove( |
1545 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1546 | size_t boff, /* starting buffer offset */ |
1547 | size_t bsize, /* length to copy */ | |
b9c48649 | 1548 | void *data, /* data address */ |
ce8e922c | 1549 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 | 1550 | { |
795cac72 | 1551 | size_t bend; |
1da177e4 LT |
1552 | |
1553 | bend = boff + bsize; | |
1554 | while (boff < bend) { | |
795cac72 DC |
1555 | struct page *page; |
1556 | int page_index, page_offset, csize; | |
1557 | ||
1558 | page_index = (boff + bp->b_offset) >> PAGE_SHIFT; | |
1559 | page_offset = (boff + bp->b_offset) & ~PAGE_MASK; | |
1560 | page = bp->b_pages[page_index]; | |
1561 | csize = min_t(size_t, PAGE_SIZE - page_offset, | |
1562 | BBTOB(bp->b_io_length) - boff); | |
1da177e4 | 1563 | |
795cac72 | 1564 | ASSERT((csize + page_offset) <= PAGE_SIZE); |
1da177e4 LT |
1565 | |
1566 | switch (mode) { | |
ce8e922c | 1567 | case XBRW_ZERO: |
795cac72 | 1568 | memset(page_address(page) + page_offset, 0, csize); |
1da177e4 | 1569 | break; |
ce8e922c | 1570 | case XBRW_READ: |
795cac72 | 1571 | memcpy(data, page_address(page) + page_offset, csize); |
1da177e4 | 1572 | break; |
ce8e922c | 1573 | case XBRW_WRITE: |
795cac72 | 1574 | memcpy(page_address(page) + page_offset, data, csize); |
1da177e4 LT |
1575 | } |
1576 | ||
1577 | boff += csize; | |
1578 | data += csize; | |
1579 | } | |
1580 | } | |
1581 | ||
1582 | /* | |
ce8e922c | 1583 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1584 | */ |
1585 | ||
1586 | /* | |
430cbeb8 DC |
1587 | * Wait for any bufs with callbacks that have been submitted but have not yet |
1588 | * returned. These buffers will have an elevated hold count, so wait on those | |
1589 | * while freeing all the buffers only held by the LRU. | |
1da177e4 | 1590 | */ |
e80dfa19 DC |
1591 | static enum lru_status |
1592 | xfs_buftarg_wait_rele( | |
1593 | struct list_head *item, | |
3f97b163 | 1594 | struct list_lru_one *lru, |
e80dfa19 DC |
1595 | spinlock_t *lru_lock, |
1596 | void *arg) | |
1597 | ||
1da177e4 | 1598 | { |
e80dfa19 | 1599 | struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru); |
a4082357 | 1600 | struct list_head *dispose = arg; |
430cbeb8 | 1601 | |
e80dfa19 | 1602 | if (atomic_read(&bp->b_hold) > 1) { |
a4082357 | 1603 | /* need to wait, so skip it this pass */ |
e80dfa19 | 1604 | trace_xfs_buf_wait_buftarg(bp, _RET_IP_); |
a4082357 | 1605 | return LRU_SKIP; |
1da177e4 | 1606 | } |
a4082357 DC |
1607 | if (!spin_trylock(&bp->b_lock)) |
1608 | return LRU_SKIP; | |
e80dfa19 | 1609 | |
a4082357 DC |
1610 | /* |
1611 | * clear the LRU reference count so the buffer doesn't get | |
1612 | * ignored in xfs_buf_rele(). | |
1613 | */ | |
1614 | atomic_set(&bp->b_lru_ref, 0); | |
1615 | bp->b_state |= XFS_BSTATE_DISPOSE; | |
3f97b163 | 1616 | list_lru_isolate_move(lru, item, dispose); |
a4082357 DC |
1617 | spin_unlock(&bp->b_lock); |
1618 | return LRU_REMOVED; | |
1da177e4 LT |
1619 | } |
1620 | ||
e80dfa19 DC |
1621 | void |
1622 | xfs_wait_buftarg( | |
1623 | struct xfs_buftarg *btp) | |
1624 | { | |
a4082357 DC |
1625 | LIST_HEAD(dispose); |
1626 | int loop = 0; | |
1627 | ||
85bec546 | 1628 | /* |
9c7504aa BF |
1629 | * First wait on the buftarg I/O count for all in-flight buffers to be |
1630 | * released. This is critical as new buffers do not make the LRU until | |
1631 | * they are released. | |
1632 | * | |
1633 | * Next, flush the buffer workqueue to ensure all completion processing | |
1634 | * has finished. Just waiting on buffer locks is not sufficient for | |
1635 | * async IO as the reference count held over IO is not released until | |
1636 | * after the buffer lock is dropped. Hence we need to ensure here that | |
1637 | * all reference counts have been dropped before we start walking the | |
1638 | * LRU list. | |
85bec546 | 1639 | */ |
9c7504aa BF |
1640 | while (percpu_counter_sum(&btp->bt_io_count)) |
1641 | delay(100); | |
800b2694 | 1642 | flush_workqueue(btp->bt_mount->m_buf_workqueue); |
85bec546 | 1643 | |
a4082357 DC |
1644 | /* loop until there is nothing left on the lru list. */ |
1645 | while (list_lru_count(&btp->bt_lru)) { | |
e80dfa19 | 1646 | list_lru_walk(&btp->bt_lru, xfs_buftarg_wait_rele, |
a4082357 DC |
1647 | &dispose, LONG_MAX); |
1648 | ||
1649 | while (!list_empty(&dispose)) { | |
1650 | struct xfs_buf *bp; | |
1651 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); | |
1652 | list_del_init(&bp->b_lru); | |
ac8809f9 DC |
1653 | if (bp->b_flags & XBF_WRITE_FAIL) { |
1654 | xfs_alert(btp->bt_mount, | |
f41febd2 | 1655 | "Corruption Alert: Buffer at block 0x%llx had permanent write failures!", |
ac8809f9 | 1656 | (long long)bp->b_bn); |
f41febd2 JP |
1657 | xfs_alert(btp->bt_mount, |
1658 | "Please run xfs_repair to determine the extent of the problem."); | |
ac8809f9 | 1659 | } |
a4082357 DC |
1660 | xfs_buf_rele(bp); |
1661 | } | |
1662 | if (loop++ != 0) | |
1663 | delay(100); | |
1664 | } | |
e80dfa19 DC |
1665 | } |
1666 | ||
1667 | static enum lru_status | |
1668 | xfs_buftarg_isolate( | |
1669 | struct list_head *item, | |
3f97b163 | 1670 | struct list_lru_one *lru, |
e80dfa19 DC |
1671 | spinlock_t *lru_lock, |
1672 | void *arg) | |
1673 | { | |
1674 | struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru); | |
1675 | struct list_head *dispose = arg; | |
1676 | ||
a4082357 DC |
1677 | /* |
1678 | * we are inverting the lru lock/bp->b_lock here, so use a trylock. | |
1679 | * If we fail to get the lock, just skip it. | |
1680 | */ | |
1681 | if (!spin_trylock(&bp->b_lock)) | |
1682 | return LRU_SKIP; | |
e80dfa19 DC |
1683 | /* |
1684 | * Decrement the b_lru_ref count unless the value is already | |
1685 | * zero. If the value is already zero, we need to reclaim the | |
1686 | * buffer, otherwise it gets another trip through the LRU. | |
1687 | */ | |
a4082357 DC |
1688 | if (!atomic_add_unless(&bp->b_lru_ref, -1, 0)) { |
1689 | spin_unlock(&bp->b_lock); | |
e80dfa19 | 1690 | return LRU_ROTATE; |
a4082357 | 1691 | } |
e80dfa19 | 1692 | |
a4082357 | 1693 | bp->b_state |= XFS_BSTATE_DISPOSE; |
3f97b163 | 1694 | list_lru_isolate_move(lru, item, dispose); |
a4082357 | 1695 | spin_unlock(&bp->b_lock); |
e80dfa19 DC |
1696 | return LRU_REMOVED; |
1697 | } | |
1698 | ||
addbda40 | 1699 | static unsigned long |
e80dfa19 | 1700 | xfs_buftarg_shrink_scan( |
ff57ab21 | 1701 | struct shrinker *shrink, |
1495f230 | 1702 | struct shrink_control *sc) |
a6867a68 | 1703 | { |
ff57ab21 DC |
1704 | struct xfs_buftarg *btp = container_of(shrink, |
1705 | struct xfs_buftarg, bt_shrinker); | |
430cbeb8 | 1706 | LIST_HEAD(dispose); |
addbda40 | 1707 | unsigned long freed; |
430cbeb8 | 1708 | |
503c358c VD |
1709 | freed = list_lru_shrink_walk(&btp->bt_lru, sc, |
1710 | xfs_buftarg_isolate, &dispose); | |
430cbeb8 DC |
1711 | |
1712 | while (!list_empty(&dispose)) { | |
e80dfa19 | 1713 | struct xfs_buf *bp; |
430cbeb8 DC |
1714 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); |
1715 | list_del_init(&bp->b_lru); | |
1716 | xfs_buf_rele(bp); | |
1717 | } | |
1718 | ||
e80dfa19 DC |
1719 | return freed; |
1720 | } | |
1721 | ||
addbda40 | 1722 | static unsigned long |
e80dfa19 DC |
1723 | xfs_buftarg_shrink_count( |
1724 | struct shrinker *shrink, | |
1725 | struct shrink_control *sc) | |
1726 | { | |
1727 | struct xfs_buftarg *btp = container_of(shrink, | |
1728 | struct xfs_buftarg, bt_shrinker); | |
503c358c | 1729 | return list_lru_shrink_count(&btp->bt_lru, sc); |
a6867a68 DC |
1730 | } |
1731 | ||
1da177e4 LT |
1732 | void |
1733 | xfs_free_buftarg( | |
b7963133 CH |
1734 | struct xfs_mount *mp, |
1735 | struct xfs_buftarg *btp) | |
1da177e4 | 1736 | { |
ff57ab21 | 1737 | unregister_shrinker(&btp->bt_shrinker); |
9c7504aa BF |
1738 | ASSERT(percpu_counter_sum(&btp->bt_io_count) == 0); |
1739 | percpu_counter_destroy(&btp->bt_io_count); | |
f5e1dd34 | 1740 | list_lru_destroy(&btp->bt_lru); |
ff57ab21 | 1741 | |
2291dab2 | 1742 | xfs_blkdev_issue_flush(btp); |
a6867a68 | 1743 | |
f0e2d93c | 1744 | kmem_free(btp); |
1da177e4 LT |
1745 | } |
1746 | ||
3fefdeee ES |
1747 | int |
1748 | xfs_setsize_buftarg( | |
1da177e4 | 1749 | xfs_buftarg_t *btp, |
3fefdeee | 1750 | unsigned int sectorsize) |
1da177e4 | 1751 | { |
7c71ee78 | 1752 | /* Set up metadata sector size info */ |
6da54179 ES |
1753 | btp->bt_meta_sectorsize = sectorsize; |
1754 | btp->bt_meta_sectormask = sectorsize - 1; | |
1da177e4 | 1755 | |
ce8e922c | 1756 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
4f10700a | 1757 | xfs_warn(btp->bt_mount, |
a1c6f057 DM |
1758 | "Cannot set_blocksize to %u on device %pg", |
1759 | sectorsize, btp->bt_bdev); | |
2451337d | 1760 | return -EINVAL; |
1da177e4 LT |
1761 | } |
1762 | ||
7c71ee78 ES |
1763 | /* Set up device logical sector size mask */ |
1764 | btp->bt_logical_sectorsize = bdev_logical_block_size(btp->bt_bdev); | |
1765 | btp->bt_logical_sectormask = bdev_logical_block_size(btp->bt_bdev) - 1; | |
1766 | ||
1da177e4 LT |
1767 | return 0; |
1768 | } | |
1769 | ||
1770 | /* | |
3fefdeee ES |
1771 | * When allocating the initial buffer target we have not yet |
1772 | * read in the superblock, so don't know what sized sectors | |
1773 | * are being used at this early stage. Play safe. | |
ce8e922c | 1774 | */ |
1da177e4 LT |
1775 | STATIC int |
1776 | xfs_setsize_buftarg_early( | |
1777 | xfs_buftarg_t *btp, | |
1778 | struct block_device *bdev) | |
1779 | { | |
a96c4151 | 1780 | return xfs_setsize_buftarg(btp, bdev_logical_block_size(bdev)); |
1da177e4 LT |
1781 | } |
1782 | ||
1da177e4 LT |
1783 | xfs_buftarg_t * |
1784 | xfs_alloc_buftarg( | |
ebad861b | 1785 | struct xfs_mount *mp, |
34dcefd7 | 1786 | struct block_device *bdev) |
1da177e4 LT |
1787 | { |
1788 | xfs_buftarg_t *btp; | |
1789 | ||
b17cb364 | 1790 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP | KM_NOFS); |
1da177e4 | 1791 | |
ebad861b | 1792 | btp->bt_mount = mp; |
ce8e922c NS |
1793 | btp->bt_dev = bdev->bd_dev; |
1794 | btp->bt_bdev = bdev; | |
0e6e847f | 1795 | |
1da177e4 LT |
1796 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1797 | goto error; | |
5ca302c8 GC |
1798 | |
1799 | if (list_lru_init(&btp->bt_lru)) | |
1800 | goto error; | |
1801 | ||
9c7504aa BF |
1802 | if (percpu_counter_init(&btp->bt_io_count, 0, GFP_KERNEL)) |
1803 | goto error; | |
1804 | ||
e80dfa19 DC |
1805 | btp->bt_shrinker.count_objects = xfs_buftarg_shrink_count; |
1806 | btp->bt_shrinker.scan_objects = xfs_buftarg_shrink_scan; | |
ff57ab21 | 1807 | btp->bt_shrinker.seeks = DEFAULT_SEEKS; |
e80dfa19 | 1808 | btp->bt_shrinker.flags = SHRINKER_NUMA_AWARE; |
ff57ab21 | 1809 | register_shrinker(&btp->bt_shrinker); |
1da177e4 LT |
1810 | return btp; |
1811 | ||
1812 | error: | |
f0e2d93c | 1813 | kmem_free(btp); |
1da177e4 LT |
1814 | return NULL; |
1815 | } | |
1816 | ||
1da177e4 | 1817 | /* |
43ff2122 CH |
1818 | * Add a buffer to the delayed write list. |
1819 | * | |
1820 | * This queues a buffer for writeout if it hasn't already been. Note that | |
1821 | * neither this routine nor the buffer list submission functions perform | |
1822 | * any internal synchronization. It is expected that the lists are thread-local | |
1823 | * to the callers. | |
1824 | * | |
1825 | * Returns true if we queued up the buffer, or false if it already had | |
1826 | * been on the buffer list. | |
1da177e4 | 1827 | */ |
43ff2122 | 1828 | bool |
ce8e922c | 1829 | xfs_buf_delwri_queue( |
43ff2122 CH |
1830 | struct xfs_buf *bp, |
1831 | struct list_head *list) | |
1da177e4 | 1832 | { |
43ff2122 | 1833 | ASSERT(xfs_buf_islocked(bp)); |
5a8ee6ba | 1834 | ASSERT(!(bp->b_flags & XBF_READ)); |
1da177e4 | 1835 | |
43ff2122 CH |
1836 | /* |
1837 | * If the buffer is already marked delwri it already is queued up | |
1838 | * by someone else for imediate writeout. Just ignore it in that | |
1839 | * case. | |
1840 | */ | |
1841 | if (bp->b_flags & _XBF_DELWRI_Q) { | |
1842 | trace_xfs_buf_delwri_queued(bp, _RET_IP_); | |
1843 | return false; | |
1da177e4 | 1844 | } |
1da177e4 | 1845 | |
43ff2122 | 1846 | trace_xfs_buf_delwri_queue(bp, _RET_IP_); |
d808f617 DC |
1847 | |
1848 | /* | |
43ff2122 CH |
1849 | * If a buffer gets written out synchronously or marked stale while it |
1850 | * is on a delwri list we lazily remove it. To do this, the other party | |
1851 | * clears the _XBF_DELWRI_Q flag but otherwise leaves the buffer alone. | |
1852 | * It remains referenced and on the list. In a rare corner case it | |
1853 | * might get readded to a delwri list after the synchronous writeout, in | |
1854 | * which case we need just need to re-add the flag here. | |
d808f617 | 1855 | */ |
43ff2122 CH |
1856 | bp->b_flags |= _XBF_DELWRI_Q; |
1857 | if (list_empty(&bp->b_list)) { | |
1858 | atomic_inc(&bp->b_hold); | |
1859 | list_add_tail(&bp->b_list, list); | |
585e6d88 | 1860 | } |
585e6d88 | 1861 | |
43ff2122 | 1862 | return true; |
585e6d88 DC |
1863 | } |
1864 | ||
089716aa DC |
1865 | /* |
1866 | * Compare function is more complex than it needs to be because | |
1867 | * the return value is only 32 bits and we are doing comparisons | |
1868 | * on 64 bit values | |
1869 | */ | |
1870 | static int | |
1871 | xfs_buf_cmp( | |
1872 | void *priv, | |
1873 | struct list_head *a, | |
1874 | struct list_head *b) | |
1875 | { | |
1876 | struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list); | |
1877 | struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); | |
1878 | xfs_daddr_t diff; | |
1879 | ||
f4b42421 | 1880 | diff = ap->b_maps[0].bm_bn - bp->b_maps[0].bm_bn; |
089716aa DC |
1881 | if (diff < 0) |
1882 | return -1; | |
1883 | if (diff > 0) | |
1884 | return 1; | |
1885 | return 0; | |
1886 | } | |
1887 | ||
26f1fe85 DC |
1888 | /* |
1889 | * submit buffers for write. | |
1890 | * | |
1891 | * When we have a large buffer list, we do not want to hold all the buffers | |
1892 | * locked while we block on the request queue waiting for IO dispatch. To avoid | |
1893 | * this problem, we lock and submit buffers in groups of 50, thereby minimising | |
1894 | * the lock hold times for lists which may contain thousands of objects. | |
1895 | * | |
1896 | * To do this, we sort the buffer list before we walk the list to lock and | |
1897 | * submit buffers, and we plug and unplug around each group of buffers we | |
1898 | * submit. | |
1899 | */ | |
43ff2122 | 1900 | static int |
26f1fe85 | 1901 | xfs_buf_delwri_submit_buffers( |
43ff2122 | 1902 | struct list_head *buffer_list, |
26f1fe85 | 1903 | struct list_head *wait_list) |
1da177e4 | 1904 | { |
43ff2122 | 1905 | struct xfs_buf *bp, *n; |
26f1fe85 | 1906 | LIST_HEAD (submit_list); |
43ff2122 | 1907 | int pinned = 0; |
26f1fe85 | 1908 | struct blk_plug plug; |
43ff2122 | 1909 | |
26f1fe85 | 1910 | list_sort(NULL, buffer_list, xfs_buf_cmp); |
43ff2122 | 1911 | |
26f1fe85 | 1912 | blk_start_plug(&plug); |
43ff2122 | 1913 | list_for_each_entry_safe(bp, n, buffer_list, b_list) { |
26f1fe85 | 1914 | if (!wait_list) { |
43ff2122 CH |
1915 | if (xfs_buf_ispinned(bp)) { |
1916 | pinned++; | |
1917 | continue; | |
1918 | } | |
1919 | if (!xfs_buf_trylock(bp)) | |
1920 | continue; | |
1921 | } else { | |
1922 | xfs_buf_lock(bp); | |
1923 | } | |
978c7b2f | 1924 | |
43ff2122 CH |
1925 | /* |
1926 | * Someone else might have written the buffer synchronously or | |
1927 | * marked it stale in the meantime. In that case only the | |
1928 | * _XBF_DELWRI_Q flag got cleared, and we have to drop the | |
1929 | * reference and remove it from the list here. | |
1930 | */ | |
1931 | if (!(bp->b_flags & _XBF_DELWRI_Q)) { | |
1932 | list_del_init(&bp->b_list); | |
1933 | xfs_buf_relse(bp); | |
1934 | continue; | |
1935 | } | |
c9c12971 | 1936 | |
43ff2122 | 1937 | trace_xfs_buf_delwri_split(bp, _RET_IP_); |
a1b7ea5d | 1938 | |
cf53e99d | 1939 | /* |
26f1fe85 DC |
1940 | * We do all IO submission async. This means if we need |
1941 | * to wait for IO completion we need to take an extra | |
1942 | * reference so the buffer is still valid on the other | |
1943 | * side. We need to move the buffer onto the io_list | |
1944 | * at this point so the caller can still access it. | |
cf53e99d | 1945 | */ |
bbfeb614 | 1946 | bp->b_flags &= ~(_XBF_DELWRI_Q | XBF_WRITE_FAIL); |
26f1fe85 DC |
1947 | bp->b_flags |= XBF_WRITE | XBF_ASYNC; |
1948 | if (wait_list) { | |
cf53e99d | 1949 | xfs_buf_hold(bp); |
26f1fe85 DC |
1950 | list_move_tail(&bp->b_list, wait_list); |
1951 | } else | |
ce8e922c | 1952 | list_del_init(&bp->b_list); |
8dac3921 | 1953 | |
595bff75 | 1954 | xfs_buf_submit(bp); |
43ff2122 CH |
1955 | } |
1956 | blk_finish_plug(&plug); | |
1da177e4 | 1957 | |
43ff2122 | 1958 | return pinned; |
1da177e4 LT |
1959 | } |
1960 | ||
1961 | /* | |
43ff2122 CH |
1962 | * Write out a buffer list asynchronously. |
1963 | * | |
1964 | * This will take the @buffer_list, write all non-locked and non-pinned buffers | |
1965 | * out and not wait for I/O completion on any of the buffers. This interface | |
1966 | * is only safely useable for callers that can track I/O completion by higher | |
1967 | * level means, e.g. AIL pushing as the @buffer_list is consumed in this | |
1968 | * function. | |
1da177e4 LT |
1969 | */ |
1970 | int | |
43ff2122 CH |
1971 | xfs_buf_delwri_submit_nowait( |
1972 | struct list_head *buffer_list) | |
1da177e4 | 1973 | { |
26f1fe85 | 1974 | return xfs_buf_delwri_submit_buffers(buffer_list, NULL); |
43ff2122 | 1975 | } |
1da177e4 | 1976 | |
43ff2122 CH |
1977 | /* |
1978 | * Write out a buffer list synchronously. | |
1979 | * | |
1980 | * This will take the @buffer_list, write all buffers out and wait for I/O | |
1981 | * completion on all of the buffers. @buffer_list is consumed by the function, | |
1982 | * so callers must have some other way of tracking buffers if they require such | |
1983 | * functionality. | |
1984 | */ | |
1985 | int | |
1986 | xfs_buf_delwri_submit( | |
1987 | struct list_head *buffer_list) | |
1988 | { | |
26f1fe85 | 1989 | LIST_HEAD (wait_list); |
43ff2122 CH |
1990 | int error = 0, error2; |
1991 | struct xfs_buf *bp; | |
1da177e4 | 1992 | |
26f1fe85 | 1993 | xfs_buf_delwri_submit_buffers(buffer_list, &wait_list); |
1da177e4 | 1994 | |
43ff2122 | 1995 | /* Wait for IO to complete. */ |
26f1fe85 DC |
1996 | while (!list_empty(&wait_list)) { |
1997 | bp = list_first_entry(&wait_list, struct xfs_buf, b_list); | |
a1b7ea5d | 1998 | |
089716aa | 1999 | list_del_init(&bp->b_list); |
cf53e99d DC |
2000 | |
2001 | /* locking the buffer will wait for async IO completion. */ | |
2002 | xfs_buf_lock(bp); | |
2003 | error2 = bp->b_error; | |
43ff2122 CH |
2004 | xfs_buf_relse(bp); |
2005 | if (!error) | |
2006 | error = error2; | |
1da177e4 LT |
2007 | } |
2008 | ||
43ff2122 | 2009 | return error; |
1da177e4 LT |
2010 | } |
2011 | ||
04d8b284 | 2012 | int __init |
ce8e922c | 2013 | xfs_buf_init(void) |
1da177e4 | 2014 | { |
8758280f NS |
2015 | xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf", |
2016 | KM_ZONE_HWALIGN, NULL); | |
ce8e922c | 2017 | if (!xfs_buf_zone) |
0b1b213f | 2018 | goto out; |
04d8b284 | 2019 | |
23ea4032 | 2020 | return 0; |
1da177e4 | 2021 | |
0b1b213f | 2022 | out: |
8758280f | 2023 | return -ENOMEM; |
1da177e4 LT |
2024 | } |
2025 | ||
1da177e4 | 2026 | void |
ce8e922c | 2027 | xfs_buf_terminate(void) |
1da177e4 | 2028 | { |
ce8e922c | 2029 | kmem_zone_destroy(xfs_buf_zone); |
1da177e4 | 2030 | } |