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0b61f8a4 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
f07c2250 | 3 | * Copyright (c) 2000-2006 Silicon Graphics, Inc. |
7b718769 | 4 | * All Rights Reserved. |
1da177e4 | 5 | */ |
93c189c1 | 6 | #include "xfs.h" |
3fcfab16 | 7 | #include <linux/backing-dev.h> |
1da177e4 | 8 | |
5467b34b | 9 | #include "xfs_shared.h" |
4fb6e8ad | 10 | #include "xfs_format.h" |
239880ef | 11 | #include "xfs_log_format.h" |
7fd36c44 | 12 | #include "xfs_trans_resv.h" |
b7963133 | 13 | #include "xfs_mount.h" |
0b1b213f | 14 | #include "xfs_trace.h" |
239880ef | 15 | #include "xfs_log.h" |
9fe5c77c | 16 | #include "xfs_log_recover.h" |
f593bf14 DC |
17 | #include "xfs_trans.h" |
18 | #include "xfs_buf_item.h" | |
e9e899a2 | 19 | #include "xfs_errortag.h" |
7561d27e | 20 | #include "xfs_error.h" |
9bbafc71 | 21 | #include "xfs_ag.h" |
b7963133 | 22 | |
7989cb8e | 23 | static kmem_zone_t *xfs_buf_zone; |
23ea4032 | 24 | |
37fd1678 DC |
25 | /* |
26 | * Locking orders | |
27 | * | |
28 | * xfs_buf_ioacct_inc: | |
29 | * xfs_buf_ioacct_dec: | |
30 | * b_sema (caller holds) | |
31 | * b_lock | |
32 | * | |
33 | * xfs_buf_stale: | |
34 | * b_sema (caller holds) | |
35 | * b_lock | |
36 | * lru_lock | |
37 | * | |
38 | * xfs_buf_rele: | |
39 | * b_lock | |
40 | * pag_buf_lock | |
41 | * lru_lock | |
42 | * | |
10fb9ac1 | 43 | * xfs_buftarg_drain_rele |
37fd1678 DC |
44 | * lru_lock |
45 | * b_lock (trylock due to inversion) | |
46 | * | |
47 | * xfs_buftarg_isolate | |
48 | * lru_lock | |
49 | * b_lock (trylock due to inversion) | |
50 | */ | |
1da177e4 | 51 | |
26e32875 CH |
52 | static int __xfs_buf_submit(struct xfs_buf *bp, bool wait); |
53 | ||
54 | static inline int | |
55 | xfs_buf_submit( | |
56 | struct xfs_buf *bp) | |
57 | { | |
58 | return __xfs_buf_submit(bp, !(bp->b_flags & XBF_ASYNC)); | |
59 | } | |
60 | ||
73c77e2c JB |
61 | static inline int |
62 | xfs_buf_is_vmapped( | |
63 | struct xfs_buf *bp) | |
64 | { | |
65 | /* | |
66 | * Return true if the buffer is vmapped. | |
67 | * | |
611c9946 DC |
68 | * b_addr is null if the buffer is not mapped, but the code is clever |
69 | * enough to know it doesn't have to map a single page, so the check has | |
70 | * to be both for b_addr and bp->b_page_count > 1. | |
73c77e2c | 71 | */ |
611c9946 | 72 | return bp->b_addr && bp->b_page_count > 1; |
73c77e2c JB |
73 | } |
74 | ||
75 | static inline int | |
76 | xfs_buf_vmap_len( | |
77 | struct xfs_buf *bp) | |
78 | { | |
54cd3aa6 | 79 | return (bp->b_page_count * PAGE_SIZE); |
73c77e2c JB |
80 | } |
81 | ||
9c7504aa BF |
82 | /* |
83 | * Bump the I/O in flight count on the buftarg if we haven't yet done so for | |
84 | * this buffer. The count is incremented once per buffer (per hold cycle) | |
85 | * because the corresponding decrement is deferred to buffer release. Buffers | |
86 | * can undergo I/O multiple times in a hold-release cycle and per buffer I/O | |
87 | * tracking adds unnecessary overhead. This is used for sychronization purposes | |
10fb9ac1 | 88 | * with unmount (see xfs_buftarg_drain()), so all we really need is a count of |
9c7504aa BF |
89 | * in-flight buffers. |
90 | * | |
91 | * Buffers that are never released (e.g., superblock, iclog buffers) must set | |
92 | * the XBF_NO_IOACCT flag before I/O submission. Otherwise, the buftarg count | |
93 | * never reaches zero and unmount hangs indefinitely. | |
94 | */ | |
95 | static inline void | |
96 | xfs_buf_ioacct_inc( | |
97 | struct xfs_buf *bp) | |
98 | { | |
63db7c81 | 99 | if (bp->b_flags & XBF_NO_IOACCT) |
9c7504aa BF |
100 | return; |
101 | ||
102 | ASSERT(bp->b_flags & XBF_ASYNC); | |
63db7c81 BF |
103 | spin_lock(&bp->b_lock); |
104 | if (!(bp->b_state & XFS_BSTATE_IN_FLIGHT)) { | |
105 | bp->b_state |= XFS_BSTATE_IN_FLIGHT; | |
106 | percpu_counter_inc(&bp->b_target->bt_io_count); | |
107 | } | |
108 | spin_unlock(&bp->b_lock); | |
9c7504aa BF |
109 | } |
110 | ||
111 | /* | |
112 | * Clear the in-flight state on a buffer about to be released to the LRU or | |
113 | * freed and unaccount from the buftarg. | |
114 | */ | |
115 | static inline void | |
63db7c81 | 116 | __xfs_buf_ioacct_dec( |
9c7504aa BF |
117 | struct xfs_buf *bp) |
118 | { | |
95989c46 | 119 | lockdep_assert_held(&bp->b_lock); |
9c7504aa | 120 | |
63db7c81 BF |
121 | if (bp->b_state & XFS_BSTATE_IN_FLIGHT) { |
122 | bp->b_state &= ~XFS_BSTATE_IN_FLIGHT; | |
123 | percpu_counter_dec(&bp->b_target->bt_io_count); | |
124 | } | |
125 | } | |
126 | ||
127 | static inline void | |
128 | xfs_buf_ioacct_dec( | |
129 | struct xfs_buf *bp) | |
130 | { | |
131 | spin_lock(&bp->b_lock); | |
132 | __xfs_buf_ioacct_dec(bp); | |
133 | spin_unlock(&bp->b_lock); | |
9c7504aa BF |
134 | } |
135 | ||
430cbeb8 DC |
136 | /* |
137 | * When we mark a buffer stale, we remove the buffer from the LRU and clear the | |
138 | * b_lru_ref count so that the buffer is freed immediately when the buffer | |
139 | * reference count falls to zero. If the buffer is already on the LRU, we need | |
140 | * to remove the reference that LRU holds on the buffer. | |
141 | * | |
142 | * This prevents build-up of stale buffers on the LRU. | |
143 | */ | |
144 | void | |
145 | xfs_buf_stale( | |
146 | struct xfs_buf *bp) | |
147 | { | |
43ff2122 CH |
148 | ASSERT(xfs_buf_islocked(bp)); |
149 | ||
430cbeb8 | 150 | bp->b_flags |= XBF_STALE; |
43ff2122 CH |
151 | |
152 | /* | |
153 | * Clear the delwri status so that a delwri queue walker will not | |
154 | * flush this buffer to disk now that it is stale. The delwri queue has | |
155 | * a reference to the buffer, so this is safe to do. | |
156 | */ | |
157 | bp->b_flags &= ~_XBF_DELWRI_Q; | |
158 | ||
9c7504aa BF |
159 | /* |
160 | * Once the buffer is marked stale and unlocked, a subsequent lookup | |
161 | * could reset b_flags. There is no guarantee that the buffer is | |
162 | * unaccounted (released to LRU) before that occurs. Drop in-flight | |
163 | * status now to preserve accounting consistency. | |
164 | */ | |
a4082357 | 165 | spin_lock(&bp->b_lock); |
63db7c81 BF |
166 | __xfs_buf_ioacct_dec(bp); |
167 | ||
a4082357 DC |
168 | atomic_set(&bp->b_lru_ref, 0); |
169 | if (!(bp->b_state & XFS_BSTATE_DISPOSE) && | |
e80dfa19 DC |
170 | (list_lru_del(&bp->b_target->bt_lru, &bp->b_lru))) |
171 | atomic_dec(&bp->b_hold); | |
172 | ||
430cbeb8 | 173 | ASSERT(atomic_read(&bp->b_hold) >= 1); |
a4082357 | 174 | spin_unlock(&bp->b_lock); |
430cbeb8 | 175 | } |
1da177e4 | 176 | |
3e85c868 DC |
177 | static int |
178 | xfs_buf_get_maps( | |
179 | struct xfs_buf *bp, | |
180 | int map_count) | |
181 | { | |
182 | ASSERT(bp->b_maps == NULL); | |
183 | bp->b_map_count = map_count; | |
184 | ||
185 | if (map_count == 1) { | |
f4b42421 | 186 | bp->b_maps = &bp->__b_map; |
3e85c868 DC |
187 | return 0; |
188 | } | |
189 | ||
190 | bp->b_maps = kmem_zalloc(map_count * sizeof(struct xfs_buf_map), | |
191 | KM_NOFS); | |
192 | if (!bp->b_maps) | |
2451337d | 193 | return -ENOMEM; |
3e85c868 DC |
194 | return 0; |
195 | } | |
196 | ||
197 | /* | |
198 | * Frees b_pages if it was allocated. | |
199 | */ | |
200 | static void | |
201 | xfs_buf_free_maps( | |
202 | struct xfs_buf *bp) | |
203 | { | |
f4b42421 | 204 | if (bp->b_maps != &bp->__b_map) { |
3e85c868 DC |
205 | kmem_free(bp->b_maps); |
206 | bp->b_maps = NULL; | |
207 | } | |
208 | } | |
209 | ||
32dff5e5 | 210 | static int |
3e85c868 | 211 | _xfs_buf_alloc( |
4347b9d7 | 212 | struct xfs_buftarg *target, |
3e85c868 DC |
213 | struct xfs_buf_map *map, |
214 | int nmaps, | |
32dff5e5 DW |
215 | xfs_buf_flags_t flags, |
216 | struct xfs_buf **bpp) | |
1da177e4 | 217 | { |
4347b9d7 | 218 | struct xfs_buf *bp; |
3e85c868 DC |
219 | int error; |
220 | int i; | |
4347b9d7 | 221 | |
32dff5e5 | 222 | *bpp = NULL; |
32a2b11f | 223 | bp = kmem_cache_zalloc(xfs_buf_zone, GFP_NOFS | __GFP_NOFAIL); |
4347b9d7 | 224 | |
1da177e4 | 225 | /* |
12bcb3f7 DC |
226 | * We don't want certain flags to appear in b_flags unless they are |
227 | * specifically set by later operations on the buffer. | |
1da177e4 | 228 | */ |
611c9946 | 229 | flags &= ~(XBF_UNMAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD); |
ce8e922c | 230 | |
ce8e922c | 231 | atomic_set(&bp->b_hold, 1); |
430cbeb8 | 232 | atomic_set(&bp->b_lru_ref, 1); |
b4dd330b | 233 | init_completion(&bp->b_iowait); |
430cbeb8 | 234 | INIT_LIST_HEAD(&bp->b_lru); |
ce8e922c | 235 | INIT_LIST_HEAD(&bp->b_list); |
643c8c05 | 236 | INIT_LIST_HEAD(&bp->b_li_list); |
a731cd11 | 237 | sema_init(&bp->b_sema, 0); /* held, no waiters */ |
a4082357 | 238 | spin_lock_init(&bp->b_lock); |
ce8e922c | 239 | bp->b_target = target; |
dbd329f1 | 240 | bp->b_mount = target->bt_mount; |
3e85c868 | 241 | bp->b_flags = flags; |
de1cbee4 | 242 | |
1da177e4 | 243 | /* |
aa0e8833 DC |
244 | * Set length and io_length to the same value initially. |
245 | * I/O routines should use io_length, which will be the same in | |
1da177e4 LT |
246 | * most cases but may be reset (e.g. XFS recovery). |
247 | */ | |
3e85c868 DC |
248 | error = xfs_buf_get_maps(bp, nmaps); |
249 | if (error) { | |
377bcd5f | 250 | kmem_cache_free(xfs_buf_zone, bp); |
32dff5e5 | 251 | return error; |
3e85c868 DC |
252 | } |
253 | ||
4c7f65ae | 254 | bp->b_rhash_key = map[0].bm_bn; |
3e85c868 DC |
255 | bp->b_length = 0; |
256 | for (i = 0; i < nmaps; i++) { | |
257 | bp->b_maps[i].bm_bn = map[i].bm_bn; | |
258 | bp->b_maps[i].bm_len = map[i].bm_len; | |
259 | bp->b_length += map[i].bm_len; | |
260 | } | |
3e85c868 | 261 | |
ce8e922c NS |
262 | atomic_set(&bp->b_pin_count, 0); |
263 | init_waitqueue_head(&bp->b_waiters); | |
264 | ||
dbd329f1 | 265 | XFS_STATS_INC(bp->b_mount, xb_create); |
0b1b213f | 266 | trace_xfs_buf_init(bp, _RET_IP_); |
4347b9d7 | 267 | |
32dff5e5 DW |
268 | *bpp = bp; |
269 | return 0; | |
1da177e4 LT |
270 | } |
271 | ||
e7d236a6 DC |
272 | static void |
273 | xfs_buf_free_pages( | |
e8222613 | 274 | struct xfs_buf *bp) |
1da177e4 | 275 | { |
e7d236a6 DC |
276 | uint i; |
277 | ||
278 | ASSERT(bp->b_flags & _XBF_PAGES); | |
279 | ||
280 | if (xfs_buf_is_vmapped(bp)) | |
54cd3aa6 | 281 | vm_unmap_ram(bp->b_addr, bp->b_page_count); |
e7d236a6 DC |
282 | |
283 | for (i = 0; i < bp->b_page_count; i++) { | |
284 | if (bp->b_pages[i]) | |
285 | __free_page(bp->b_pages[i]); | |
286 | } | |
287 | if (current->reclaim_state) | |
288 | current->reclaim_state->reclaimed_slab += bp->b_page_count; | |
289 | ||
02c51173 | 290 | if (bp->b_pages != bp->b_page_array) |
f0e2d93c | 291 | kmem_free(bp->b_pages); |
02c51173 | 292 | bp->b_pages = NULL; |
e7d236a6 | 293 | bp->b_flags &= ~_XBF_PAGES; |
1da177e4 LT |
294 | } |
295 | ||
25a40957 | 296 | static void |
ce8e922c | 297 | xfs_buf_free( |
e8222613 | 298 | struct xfs_buf *bp) |
1da177e4 | 299 | { |
0b1b213f | 300 | trace_xfs_buf_free(bp, _RET_IP_); |
1da177e4 | 301 | |
430cbeb8 DC |
302 | ASSERT(list_empty(&bp->b_lru)); |
303 | ||
e7d236a6 DC |
304 | if (bp->b_flags & _XBF_PAGES) |
305 | xfs_buf_free_pages(bp); | |
306 | else if (bp->b_flags & _XBF_KMEM) | |
0e6e847f | 307 | kmem_free(bp->b_addr); |
e7d236a6 | 308 | |
3e85c868 | 309 | xfs_buf_free_maps(bp); |
377bcd5f | 310 | kmem_cache_free(xfs_buf_zone, bp); |
1da177e4 LT |
311 | } |
312 | ||
0a683794 DC |
313 | static int |
314 | xfs_buf_alloc_kmem( | |
315 | struct xfs_buf *bp, | |
0a683794 | 316 | xfs_buf_flags_t flags) |
1da177e4 | 317 | { |
0a683794 | 318 | xfs_km_flags_t kmflag_mask = KM_NOFS; |
8bcac744 | 319 | size_t size = BBTOB(bp->b_length); |
3219e8cf | 320 | |
0a683794 DC |
321 | /* Assure zeroed buffer for non-read cases. */ |
322 | if (!(flags & XBF_READ)) | |
3219e8cf | 323 | kmflag_mask |= KM_ZERO; |
1da177e4 | 324 | |
98fe2c3c | 325 | bp->b_addr = kmem_alloc(size, kmflag_mask); |
0a683794 DC |
326 | if (!bp->b_addr) |
327 | return -ENOMEM; | |
0e6e847f | 328 | |
0a683794 DC |
329 | if (((unsigned long)(bp->b_addr + size - 1) & PAGE_MASK) != |
330 | ((unsigned long)bp->b_addr & PAGE_MASK)) { | |
331 | /* b_addr spans two pages - use alloc_page instead */ | |
332 | kmem_free(bp->b_addr); | |
333 | bp->b_addr = NULL; | |
334 | return -ENOMEM; | |
0e6e847f | 335 | } |
0a683794 DC |
336 | bp->b_offset = offset_in_page(bp->b_addr); |
337 | bp->b_pages = bp->b_page_array; | |
338 | bp->b_pages[0] = kmem_to_page(bp->b_addr); | |
339 | bp->b_page_count = 1; | |
340 | bp->b_flags |= _XBF_KMEM; | |
341 | return 0; | |
342 | } | |
343 | ||
344 | static int | |
345 | xfs_buf_alloc_pages( | |
346 | struct xfs_buf *bp, | |
0a683794 DC |
347 | xfs_buf_flags_t flags) |
348 | { | |
289ae7b4 | 349 | gfp_t gfp_mask = __GFP_NOWARN; |
c9fa5630 | 350 | long filled = 0; |
0a683794 | 351 | |
289ae7b4 DC |
352 | if (flags & XBF_READ_AHEAD) |
353 | gfp_mask |= __GFP_NORETRY; | |
354 | else | |
355 | gfp_mask |= GFP_NOFS; | |
356 | ||
02c51173 | 357 | /* Make sure that we have a page list */ |
934d1076 | 358 | bp->b_page_count = DIV_ROUND_UP(BBTOB(bp->b_length), PAGE_SIZE); |
02c51173 DC |
359 | if (bp->b_page_count <= XB_PAGES) { |
360 | bp->b_pages = bp->b_page_array; | |
361 | } else { | |
362 | bp->b_pages = kzalloc(sizeof(struct page *) * bp->b_page_count, | |
363 | gfp_mask); | |
364 | if (!bp->b_pages) | |
365 | return -ENOMEM; | |
366 | } | |
367 | bp->b_flags |= _XBF_PAGES; | |
368 | ||
0a683794 DC |
369 | /* Assure zeroed buffer for non-read cases. */ |
370 | if (!(flags & XBF_READ)) | |
371 | gfp_mask |= __GFP_ZERO; | |
0e6e847f | 372 | |
c9fa5630 DC |
373 | /* |
374 | * Bulk filling of pages can take multiple calls. Not filling the entire | |
375 | * array is not an allocation failure, so don't back off if we get at | |
376 | * least one extra page. | |
377 | */ | |
378 | for (;;) { | |
379 | long last = filled; | |
380 | ||
381 | filled = alloc_pages_bulk_array(gfp_mask, bp->b_page_count, | |
382 | bp->b_pages); | |
383 | if (filled == bp->b_page_count) { | |
384 | XFS_STATS_INC(bp->b_mount, xb_page_found); | |
385 | break; | |
1da177e4 LT |
386 | } |
387 | ||
c9fa5630 DC |
388 | if (filled != last) |
389 | continue; | |
390 | ||
391 | if (flags & XBF_READ_AHEAD) { | |
e7d236a6 DC |
392 | xfs_buf_free_pages(bp); |
393 | return -ENOMEM; | |
c9fa5630 | 394 | } |
1da177e4 | 395 | |
c9fa5630 DC |
396 | XFS_STATS_INC(bp->b_mount, xb_page_retries); |
397 | congestion_wait(BLK_RW_ASYNC, HZ / 50); | |
1da177e4 | 398 | } |
0e6e847f | 399 | return 0; |
1da177e4 LT |
400 | } |
401 | ||
402 | /* | |
25985edc | 403 | * Map buffer into kernel address-space if necessary. |
1da177e4 LT |
404 | */ |
405 | STATIC int | |
ce8e922c | 406 | _xfs_buf_map_pages( |
e8222613 | 407 | struct xfs_buf *bp, |
1da177e4 LT |
408 | uint flags) |
409 | { | |
0e6e847f | 410 | ASSERT(bp->b_flags & _XBF_PAGES); |
ce8e922c | 411 | if (bp->b_page_count == 1) { |
0e6e847f | 412 | /* A single page buffer is always mappable */ |
54cd3aa6 | 413 | bp->b_addr = page_address(bp->b_pages[0]); |
611c9946 DC |
414 | } else if (flags & XBF_UNMAPPED) { |
415 | bp->b_addr = NULL; | |
416 | } else { | |
a19fb380 | 417 | int retried = 0; |
9ba1fb2c | 418 | unsigned nofs_flag; |
ae687e58 DC |
419 | |
420 | /* | |
cf085a1b | 421 | * vm_map_ram() will allocate auxiliary structures (e.g. |
ae687e58 DC |
422 | * pagetables) with GFP_KERNEL, yet we are likely to be under |
423 | * GFP_NOFS context here. Hence we need to tell memory reclaim | |
9ba1fb2c | 424 | * that we are in such a context via PF_MEMALLOC_NOFS to prevent |
ae687e58 DC |
425 | * memory reclaim re-entering the filesystem here and |
426 | * potentially deadlocking. | |
427 | */ | |
9ba1fb2c | 428 | nofs_flag = memalloc_nofs_save(); |
a19fb380 DC |
429 | do { |
430 | bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, | |
d4efd79a | 431 | -1); |
a19fb380 DC |
432 | if (bp->b_addr) |
433 | break; | |
434 | vm_unmap_aliases(); | |
435 | } while (retried++ <= 1); | |
9ba1fb2c | 436 | memalloc_nofs_restore(nofs_flag); |
a19fb380 DC |
437 | |
438 | if (!bp->b_addr) | |
1da177e4 | 439 | return -ENOMEM; |
1da177e4 LT |
440 | } |
441 | ||
442 | return 0; | |
443 | } | |
444 | ||
445 | /* | |
446 | * Finding and Reading Buffers | |
447 | */ | |
6031e73a LS |
448 | static int |
449 | _xfs_buf_obj_cmp( | |
450 | struct rhashtable_compare_arg *arg, | |
451 | const void *obj) | |
452 | { | |
453 | const struct xfs_buf_map *map = arg->key; | |
454 | const struct xfs_buf *bp = obj; | |
455 | ||
456 | /* | |
457 | * The key hashing in the lookup path depends on the key being the | |
458 | * first element of the compare_arg, make sure to assert this. | |
459 | */ | |
460 | BUILD_BUG_ON(offsetof(struct xfs_buf_map, bm_bn) != 0); | |
461 | ||
4c7f65ae | 462 | if (bp->b_rhash_key != map->bm_bn) |
6031e73a LS |
463 | return 1; |
464 | ||
465 | if (unlikely(bp->b_length != map->bm_len)) { | |
466 | /* | |
467 | * found a block number match. If the range doesn't | |
468 | * match, the only way this is allowed is if the buffer | |
469 | * in the cache is stale and the transaction that made | |
470 | * it stale has not yet committed. i.e. we are | |
471 | * reallocating a busy extent. Skip this buffer and | |
472 | * continue searching for an exact match. | |
473 | */ | |
474 | ASSERT(bp->b_flags & XBF_STALE); | |
475 | return 1; | |
476 | } | |
477 | return 0; | |
478 | } | |
479 | ||
480 | static const struct rhashtable_params xfs_buf_hash_params = { | |
481 | .min_size = 32, /* empty AGs have minimal footprint */ | |
482 | .nelem_hint = 16, | |
483 | .key_len = sizeof(xfs_daddr_t), | |
4c7f65ae | 484 | .key_offset = offsetof(struct xfs_buf, b_rhash_key), |
6031e73a LS |
485 | .head_offset = offsetof(struct xfs_buf, b_rhash_head), |
486 | .automatic_shrinking = true, | |
487 | .obj_cmpfn = _xfs_buf_obj_cmp, | |
488 | }; | |
489 | ||
490 | int | |
491 | xfs_buf_hash_init( | |
492 | struct xfs_perag *pag) | |
493 | { | |
494 | spin_lock_init(&pag->pag_buf_lock); | |
495 | return rhashtable_init(&pag->pag_buf_hash, &xfs_buf_hash_params); | |
496 | } | |
497 | ||
498 | void | |
499 | xfs_buf_hash_destroy( | |
500 | struct xfs_perag *pag) | |
501 | { | |
502 | rhashtable_destroy(&pag->pag_buf_hash); | |
503 | } | |
1da177e4 LT |
504 | |
505 | /* | |
b027d4c9 DC |
506 | * Look up a buffer in the buffer cache and return it referenced and locked |
507 | * in @found_bp. | |
508 | * | |
509 | * If @new_bp is supplied and we have a lookup miss, insert @new_bp into the | |
510 | * cache. | |
511 | * | |
512 | * If XBF_TRYLOCK is set in @flags, only try to lock the buffer and return | |
513 | * -EAGAIN if we fail to lock it. | |
514 | * | |
515 | * Return values are: | |
516 | * -EFSCORRUPTED if have been supplied with an invalid address | |
517 | * -EAGAIN on trylock failure | |
518 | * -ENOENT if we fail to find a match and @new_bp was NULL | |
519 | * 0, with @found_bp: | |
520 | * - @new_bp if we inserted it into the cache | |
521 | * - the buffer we found and locked. | |
1da177e4 | 522 | */ |
b027d4c9 DC |
523 | static int |
524 | xfs_buf_find( | |
e70b73f8 | 525 | struct xfs_buftarg *btp, |
3e85c868 DC |
526 | struct xfs_buf_map *map, |
527 | int nmaps, | |
ce8e922c | 528 | xfs_buf_flags_t flags, |
b027d4c9 DC |
529 | struct xfs_buf *new_bp, |
530 | struct xfs_buf **found_bp) | |
1da177e4 | 531 | { |
74f75a0c | 532 | struct xfs_perag *pag; |
e8222613 | 533 | struct xfs_buf *bp; |
6031e73a | 534 | struct xfs_buf_map cmap = { .bm_bn = map[0].bm_bn }; |
10616b80 | 535 | xfs_daddr_t eofs; |
3e85c868 | 536 | int i; |
1da177e4 | 537 | |
b027d4c9 DC |
538 | *found_bp = NULL; |
539 | ||
3e85c868 | 540 | for (i = 0; i < nmaps; i++) |
6031e73a | 541 | cmap.bm_len += map[i].bm_len; |
1da177e4 LT |
542 | |
543 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
6031e73a LS |
544 | ASSERT(!(BBTOB(cmap.bm_len) < btp->bt_meta_sectorsize)); |
545 | ASSERT(!(BBTOB(cmap.bm_bn) & (xfs_off_t)btp->bt_meta_sectormask)); | |
1da177e4 | 546 | |
10616b80 DC |
547 | /* |
548 | * Corrupted block numbers can get through to here, unfortunately, so we | |
549 | * have to check that the buffer falls within the filesystem bounds. | |
550 | */ | |
551 | eofs = XFS_FSB_TO_BB(btp->bt_mount, btp->bt_mount->m_sb.sb_dblocks); | |
6031e73a | 552 | if (cmap.bm_bn < 0 || cmap.bm_bn >= eofs) { |
10616b80 | 553 | xfs_alert(btp->bt_mount, |
c219b015 | 554 | "%s: daddr 0x%llx out of range, EOFS 0x%llx", |
6031e73a | 555 | __func__, cmap.bm_bn, eofs); |
7bc0dc27 | 556 | WARN_ON(1); |
b027d4c9 | 557 | return -EFSCORRUPTED; |
10616b80 DC |
558 | } |
559 | ||
74f75a0c | 560 | pag = xfs_perag_get(btp->bt_mount, |
6031e73a | 561 | xfs_daddr_to_agno(btp->bt_mount, cmap.bm_bn)); |
74f75a0c | 562 | |
74f75a0c | 563 | spin_lock(&pag->pag_buf_lock); |
6031e73a LS |
564 | bp = rhashtable_lookup_fast(&pag->pag_buf_hash, &cmap, |
565 | xfs_buf_hash_params); | |
566 | if (bp) { | |
567 | atomic_inc(&bp->b_hold); | |
568 | goto found; | |
1da177e4 LT |
569 | } |
570 | ||
571 | /* No match found */ | |
b027d4c9 | 572 | if (!new_bp) { |
ff6d6af2 | 573 | XFS_STATS_INC(btp->bt_mount, xb_miss_locked); |
74f75a0c DC |
574 | spin_unlock(&pag->pag_buf_lock); |
575 | xfs_perag_put(pag); | |
b027d4c9 | 576 | return -ENOENT; |
1da177e4 | 577 | } |
b027d4c9 DC |
578 | |
579 | /* the buffer keeps the perag reference until it is freed */ | |
580 | new_bp->b_pag = pag; | |
581 | rhashtable_insert_fast(&pag->pag_buf_hash, &new_bp->b_rhash_head, | |
582 | xfs_buf_hash_params); | |
583 | spin_unlock(&pag->pag_buf_lock); | |
584 | *found_bp = new_bp; | |
585 | return 0; | |
1da177e4 LT |
586 | |
587 | found: | |
74f75a0c DC |
588 | spin_unlock(&pag->pag_buf_lock); |
589 | xfs_perag_put(pag); | |
1da177e4 | 590 | |
0c842ad4 CH |
591 | if (!xfs_buf_trylock(bp)) { |
592 | if (flags & XBF_TRYLOCK) { | |
ce8e922c | 593 | xfs_buf_rele(bp); |
ff6d6af2 | 594 | XFS_STATS_INC(btp->bt_mount, xb_busy_locked); |
b027d4c9 | 595 | return -EAGAIN; |
1da177e4 | 596 | } |
0c842ad4 | 597 | xfs_buf_lock(bp); |
ff6d6af2 | 598 | XFS_STATS_INC(btp->bt_mount, xb_get_locked_waited); |
1da177e4 LT |
599 | } |
600 | ||
0e6e847f DC |
601 | /* |
602 | * if the buffer is stale, clear all the external state associated with | |
603 | * it. We need to keep flags such as how we allocated the buffer memory | |
604 | * intact here. | |
605 | */ | |
ce8e922c NS |
606 | if (bp->b_flags & XBF_STALE) { |
607 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
611c9946 | 608 | bp->b_flags &= _XBF_KMEM | _XBF_PAGES; |
1813dd64 | 609 | bp->b_ops = NULL; |
2f926587 | 610 | } |
0b1b213f CH |
611 | |
612 | trace_xfs_buf_find(bp, flags, _RET_IP_); | |
ff6d6af2 | 613 | XFS_STATS_INC(btp->bt_mount, xb_get_locked); |
b027d4c9 DC |
614 | *found_bp = bp; |
615 | return 0; | |
1da177e4 LT |
616 | } |
617 | ||
8925a3dc DC |
618 | struct xfs_buf * |
619 | xfs_buf_incore( | |
620 | struct xfs_buftarg *target, | |
621 | xfs_daddr_t blkno, | |
622 | size_t numblks, | |
623 | xfs_buf_flags_t flags) | |
624 | { | |
b027d4c9 DC |
625 | struct xfs_buf *bp; |
626 | int error; | |
8925a3dc | 627 | DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); |
b027d4c9 DC |
628 | |
629 | error = xfs_buf_find(target, &map, 1, flags, NULL, &bp); | |
630 | if (error) | |
631 | return NULL; | |
632 | return bp; | |
8925a3dc DC |
633 | } |
634 | ||
1da177e4 | 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 | */ |
3848b5f6 | 640 | int |
6dde2707 DC |
641 | xfs_buf_get_map( |
642 | struct xfs_buftarg *target, | |
643 | struct xfs_buf_map *map, | |
644 | int nmaps, | |
3848b5f6 DW |
645 | xfs_buf_flags_t flags, |
646 | struct xfs_buf **bpp) | |
1da177e4 | 647 | { |
3815832a DC |
648 | struct xfs_buf *bp; |
649 | struct xfs_buf *new_bp; | |
9bb38aa0 | 650 | int error; |
1da177e4 | 651 | |
3848b5f6 | 652 | *bpp = NULL; |
b027d4c9 | 653 | error = xfs_buf_find(target, map, nmaps, flags, NULL, &bp); |
3848b5f6 | 654 | if (!error) |
3815832a | 655 | goto found; |
3848b5f6 DW |
656 | if (error != -ENOENT) |
657 | return error; | |
3815832a | 658 | |
32dff5e5 DW |
659 | error = _xfs_buf_alloc(target, map, nmaps, flags, &new_bp); |
660 | if (error) | |
3848b5f6 | 661 | return error; |
1da177e4 | 662 | |
8bcac744 DC |
663 | /* |
664 | * For buffers that fit entirely within a single page, first attempt to | |
665 | * allocate the memory from the heap to minimise memory usage. If we | |
666 | * can't get heap memory for these small buffers, we fall back to using | |
667 | * the page allocator. | |
668 | */ | |
669 | if (BBTOB(new_bp->b_length) >= PAGE_SIZE || | |
670 | xfs_buf_alloc_kmem(new_bp, flags) < 0) { | |
671 | error = xfs_buf_alloc_pages(new_bp, flags); | |
672 | if (error) | |
673 | goto out_free_buf; | |
674 | } | |
fe2429b0 | 675 | |
b027d4c9 | 676 | error = xfs_buf_find(target, map, nmaps, flags, new_bp, &bp); |
170041f7 CH |
677 | if (error) |
678 | goto out_free_buf; | |
3815832a | 679 | |
fe2429b0 DC |
680 | if (bp != new_bp) |
681 | xfs_buf_free(new_bp); | |
1da177e4 | 682 | |
3815832a | 683 | found: |
611c9946 | 684 | if (!bp->b_addr) { |
ce8e922c | 685 | error = _xfs_buf_map_pages(bp, flags); |
1da177e4 | 686 | if (unlikely(error)) { |
93baa55a DW |
687 | xfs_warn_ratelimited(target->bt_mount, |
688 | "%s: failed to map %u pages", __func__, | |
689 | bp->b_page_count); | |
a8acad70 | 690 | xfs_buf_relse(bp); |
3848b5f6 | 691 | return error; |
1da177e4 LT |
692 | } |
693 | } | |
694 | ||
b79f4a1c DC |
695 | /* |
696 | * Clear b_error if this is a lookup from a caller that doesn't expect | |
697 | * valid data to be found in the buffer. | |
698 | */ | |
699 | if (!(flags & XBF_READ)) | |
700 | xfs_buf_ioerror(bp, 0); | |
701 | ||
ff6d6af2 | 702 | XFS_STATS_INC(target->bt_mount, xb_get); |
0b1b213f | 703 | trace_xfs_buf_get(bp, flags, _RET_IP_); |
3848b5f6 DW |
704 | *bpp = bp; |
705 | return 0; | |
170041f7 CH |
706 | out_free_buf: |
707 | xfs_buf_free(new_bp); | |
708 | return error; | |
1da177e4 LT |
709 | } |
710 | ||
26e32875 | 711 | int |
5d765b97 | 712 | _xfs_buf_read( |
e8222613 | 713 | struct xfs_buf *bp, |
5d765b97 CH |
714 | xfs_buf_flags_t flags) |
715 | { | |
43ff2122 | 716 | ASSERT(!(flags & XBF_WRITE)); |
f4b42421 | 717 | ASSERT(bp->b_maps[0].bm_bn != XFS_BUF_DADDR_NULL); |
5d765b97 | 718 | |
26e32875 | 719 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD | XBF_DONE); |
1d5ae5df | 720 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD); |
5d765b97 | 721 | |
6af88cda | 722 | return xfs_buf_submit(bp); |
5d765b97 CH |
723 | } |
724 | ||
1aff5696 | 725 | /* |
75d02303 | 726 | * Reverify a buffer found in cache without an attached ->b_ops. |
add46b3b | 727 | * |
75d02303 BF |
728 | * If the caller passed an ops structure and the buffer doesn't have ops |
729 | * assigned, set the ops and use it to verify the contents. If verification | |
730 | * fails, clear XBF_DONE. We assume the buffer has no recorded errors and is | |
731 | * already in XBF_DONE state on entry. | |
add46b3b | 732 | * |
75d02303 BF |
733 | * Under normal operations, every in-core buffer is verified on read I/O |
734 | * completion. There are two scenarios that can lead to in-core buffers without | |
735 | * an assigned ->b_ops. The first is during log recovery of buffers on a V4 | |
736 | * filesystem, though these buffers are purged at the end of recovery. The | |
737 | * other is online repair, which intentionally reads with a NULL buffer ops to | |
738 | * run several verifiers across an in-core buffer in order to establish buffer | |
739 | * type. If repair can't establish that, the buffer will be left in memory | |
740 | * with NULL buffer ops. | |
1aff5696 DW |
741 | */ |
742 | int | |
75d02303 | 743 | xfs_buf_reverify( |
1aff5696 DW |
744 | struct xfs_buf *bp, |
745 | const struct xfs_buf_ops *ops) | |
746 | { | |
747 | ASSERT(bp->b_flags & XBF_DONE); | |
748 | ASSERT(bp->b_error == 0); | |
749 | ||
750 | if (!ops || bp->b_ops) | |
751 | return 0; | |
752 | ||
753 | bp->b_ops = ops; | |
754 | bp->b_ops->verify_read(bp); | |
755 | if (bp->b_error) | |
756 | bp->b_flags &= ~XBF_DONE; | |
757 | return bp->b_error; | |
758 | } | |
759 | ||
4ed8e27b | 760 | int |
6dde2707 DC |
761 | xfs_buf_read_map( |
762 | struct xfs_buftarg *target, | |
763 | struct xfs_buf_map *map, | |
764 | int nmaps, | |
c3f8fc73 | 765 | xfs_buf_flags_t flags, |
4ed8e27b | 766 | struct xfs_buf **bpp, |
cdbcf82b DW |
767 | const struct xfs_buf_ops *ops, |
768 | xfs_failaddr_t fa) | |
1da177e4 | 769 | { |
6dde2707 | 770 | struct xfs_buf *bp; |
3848b5f6 | 771 | int error; |
ce8e922c NS |
772 | |
773 | flags |= XBF_READ; | |
4ed8e27b | 774 | *bpp = NULL; |
ce8e922c | 775 | |
3848b5f6 DW |
776 | error = xfs_buf_get_map(target, map, nmaps, flags, &bp); |
777 | if (error) | |
4ed8e27b | 778 | return error; |
0b1b213f | 779 | |
1aff5696 DW |
780 | trace_xfs_buf_read(bp, flags, _RET_IP_); |
781 | ||
782 | if (!(bp->b_flags & XBF_DONE)) { | |
4ed8e27b | 783 | /* Initiate the buffer read and wait. */ |
1aff5696 DW |
784 | XFS_STATS_INC(target->bt_mount, xb_get_read); |
785 | bp->b_ops = ops; | |
4ed8e27b DW |
786 | error = _xfs_buf_read(bp, flags); |
787 | ||
788 | /* Readahead iodone already dropped the buffer, so exit. */ | |
789 | if (flags & XBF_ASYNC) | |
790 | return 0; | |
791 | } else { | |
792 | /* Buffer already read; all we need to do is check it. */ | |
793 | error = xfs_buf_reverify(bp, ops); | |
794 | ||
795 | /* Readahead already finished; drop the buffer and exit. */ | |
796 | if (flags & XBF_ASYNC) { | |
797 | xfs_buf_relse(bp); | |
798 | return 0; | |
799 | } | |
800 | ||
801 | /* We do not want read in the flags */ | |
802 | bp->b_flags &= ~XBF_READ; | |
803 | ASSERT(bp->b_ops != NULL || ops == NULL); | |
1aff5696 DW |
804 | } |
805 | ||
4ed8e27b DW |
806 | /* |
807 | * If we've had a read error, then the contents of the buffer are | |
808 | * invalid and should not be used. To ensure that a followup read tries | |
809 | * to pull the buffer from disk again, we clear the XBF_DONE flag and | |
810 | * mark the buffer stale. This ensures that anyone who has a current | |
811 | * reference to the buffer will interpret it's contents correctly and | |
812 | * future cache lookups will also treat it as an empty, uninitialised | |
813 | * buffer. | |
814 | */ | |
815 | if (error) { | |
75c8c50f | 816 | if (!xfs_is_shutdown(target->bt_mount)) |
cdbcf82b | 817 | xfs_buf_ioerror_alert(bp, fa); |
1aff5696 | 818 | |
4ed8e27b DW |
819 | bp->b_flags &= ~XBF_DONE; |
820 | xfs_buf_stale(bp); | |
1aff5696 | 821 | xfs_buf_relse(bp); |
4ed8e27b DW |
822 | |
823 | /* bad CRC means corrupted metadata */ | |
824 | if (error == -EFSBADCRC) | |
825 | error = -EFSCORRUPTED; | |
826 | return error; | |
1da177e4 LT |
827 | } |
828 | ||
4ed8e27b DW |
829 | *bpp = bp; |
830 | return 0; | |
1da177e4 LT |
831 | } |
832 | ||
1da177e4 | 833 | /* |
ce8e922c NS |
834 | * If we are not low on memory then do the readahead in a deadlock |
835 | * safe manner. | |
1da177e4 LT |
836 | */ |
837 | void | |
6dde2707 DC |
838 | xfs_buf_readahead_map( |
839 | struct xfs_buftarg *target, | |
840 | struct xfs_buf_map *map, | |
c3f8fc73 | 841 | int nmaps, |
1813dd64 | 842 | const struct xfs_buf_ops *ops) |
1da177e4 | 843 | { |
4ed8e27b DW |
844 | struct xfs_buf *bp; |
845 | ||
a11d7fc2 | 846 | if (bdi_read_congested(target->bt_bdev->bd_disk->bdi)) |
1da177e4 LT |
847 | return; |
848 | ||
6dde2707 | 849 | xfs_buf_read_map(target, map, nmaps, |
cdbcf82b DW |
850 | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD, &bp, ops, |
851 | __this_address); | |
1da177e4 LT |
852 | } |
853 | ||
5adc94c2 DC |
854 | /* |
855 | * Read an uncached buffer from disk. Allocates and returns a locked | |
4c7f65ae DC |
856 | * buffer containing the disk contents or nothing. Uncached buffers always have |
857 | * a cache index of XFS_BUF_DADDR_NULL so we can easily determine if the buffer | |
858 | * is cached or uncached during fault diagnosis. | |
5adc94c2 | 859 | */ |
ba372674 | 860 | int |
5adc94c2 | 861 | xfs_buf_read_uncached( |
5adc94c2 DC |
862 | struct xfs_buftarg *target, |
863 | xfs_daddr_t daddr, | |
e70b73f8 | 864 | size_t numblks, |
c3f8fc73 | 865 | int flags, |
ba372674 | 866 | struct xfs_buf **bpp, |
1813dd64 | 867 | const struct xfs_buf_ops *ops) |
5adc94c2 | 868 | { |
eab4e633 | 869 | struct xfs_buf *bp; |
2842b6db | 870 | int error; |
5adc94c2 | 871 | |
ba372674 DC |
872 | *bpp = NULL; |
873 | ||
2842b6db DW |
874 | error = xfs_buf_get_uncached(target, numblks, flags, &bp); |
875 | if (error) | |
876 | return error; | |
5adc94c2 DC |
877 | |
878 | /* set up the buffer for a read IO */ | |
3e85c868 | 879 | ASSERT(bp->b_map_count == 1); |
4c7f65ae | 880 | bp->b_rhash_key = XFS_BUF_DADDR_NULL; |
3e85c868 | 881 | bp->b_maps[0].bm_bn = daddr; |
cbb7baab | 882 | bp->b_flags |= XBF_READ; |
1813dd64 | 883 | bp->b_ops = ops; |
5adc94c2 | 884 | |
6af88cda | 885 | xfs_buf_submit(bp); |
ba372674 | 886 | if (bp->b_error) { |
2842b6db | 887 | error = bp->b_error; |
83a0adc3 | 888 | xfs_buf_relse(bp); |
ba372674 | 889 | return error; |
83a0adc3 | 890 | } |
ba372674 DC |
891 | |
892 | *bpp = bp; | |
893 | return 0; | |
1da177e4 LT |
894 | } |
895 | ||
2842b6db | 896 | int |
686865f7 DC |
897 | xfs_buf_get_uncached( |
898 | struct xfs_buftarg *target, | |
e70b73f8 | 899 | size_t numblks, |
2842b6db DW |
900 | int flags, |
901 | struct xfs_buf **bpp) | |
1da177e4 | 902 | { |
07b5c5ad | 903 | int error; |
3e85c868 DC |
904 | struct xfs_buf *bp; |
905 | DEFINE_SINGLE_BUF_MAP(map, XFS_BUF_DADDR_NULL, numblks); | |
1da177e4 | 906 | |
2842b6db DW |
907 | *bpp = NULL; |
908 | ||
c891c30a | 909 | /* flags might contain irrelevant bits, pass only what we care about */ |
32dff5e5 DW |
910 | error = _xfs_buf_alloc(target, &map, 1, flags & XBF_NO_IOACCT, &bp); |
911 | if (error) | |
07b5c5ad | 912 | return error; |
1da177e4 | 913 | |
934d1076 | 914 | error = xfs_buf_alloc_pages(bp, flags); |
1fa40b01 | 915 | if (error) |
1da177e4 LT |
916 | goto fail_free_buf; |
917 | ||
611c9946 | 918 | error = _xfs_buf_map_pages(bp, 0); |
1fa40b01 | 919 | if (unlikely(error)) { |
4f10700a | 920 | xfs_warn(target->bt_mount, |
08e96e1a | 921 | "%s: failed to map pages", __func__); |
07b5c5ad | 922 | goto fail_free_buf; |
1fa40b01 | 923 | } |
1da177e4 | 924 | |
686865f7 | 925 | trace_xfs_buf_get_uncached(bp, _RET_IP_); |
2842b6db DW |
926 | *bpp = bp; |
927 | return 0; | |
1fa40b01 | 928 | |
07b5c5ad DC |
929 | fail_free_buf: |
930 | xfs_buf_free(bp); | |
2842b6db | 931 | return error; |
1da177e4 LT |
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 | 940 | xfs_buf_hold( |
e8222613 | 941 | struct xfs_buf *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 | 952 | xfs_buf_rele( |
e8222613 | 953 | struct xfs_buf *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 | |
37fd1678 DC |
972 | /* |
973 | * We grab the b_lock here first to serialise racing xfs_buf_rele() | |
974 | * calls. The pag_buf_lock being taken on the last reference only | |
975 | * serialises against racing lookups in xfs_buf_find(). IOWs, the second | |
976 | * to last reference we drop here is not serialised against the last | |
977 | * reference until we take bp->b_lock. Hence if we don't grab b_lock | |
978 | * first, the last "release" reference can win the race to the lock and | |
979 | * free the buffer before the second-to-last reference is processed, | |
980 | * leading to a use-after-free scenario. | |
981 | */ | |
9c7504aa | 982 | spin_lock(&bp->b_lock); |
37fd1678 | 983 | release = atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock); |
9c7504aa BF |
984 | if (!release) { |
985 | /* | |
986 | * Drop the in-flight state if the buffer is already on the LRU | |
987 | * and it holds the only reference. This is racy because we | |
988 | * haven't acquired the pag lock, but the use of _XBF_IN_FLIGHT | |
989 | * ensures the decrement occurs only once per-buf. | |
990 | */ | |
991 | if ((atomic_read(&bp->b_hold) == 1) && !list_empty(&bp->b_lru)) | |
63db7c81 | 992 | __xfs_buf_ioacct_dec(bp); |
9c7504aa BF |
993 | goto out_unlock; |
994 | } | |
995 | ||
996 | /* the last reference has been dropped ... */ | |
63db7c81 | 997 | __xfs_buf_ioacct_dec(bp); |
9c7504aa BF |
998 | if (!(bp->b_flags & XBF_STALE) && atomic_read(&bp->b_lru_ref)) { |
999 | /* | |
1000 | * If the buffer is added to the LRU take a new reference to the | |
1001 | * buffer for the LRU and clear the (now stale) dispose list | |
1002 | * state flag | |
1003 | */ | |
1004 | if (list_lru_add(&bp->b_target->bt_lru, &bp->b_lru)) { | |
1005 | bp->b_state &= ~XFS_BSTATE_DISPOSE; | |
1006 | atomic_inc(&bp->b_hold); | |
1da177e4 | 1007 | } |
9c7504aa BF |
1008 | spin_unlock(&pag->pag_buf_lock); |
1009 | } else { | |
1010 | /* | |
1011 | * most of the time buffers will already be removed from the | |
1012 | * LRU, so optimise that case by checking for the | |
1013 | * XFS_BSTATE_DISPOSE flag indicating the last list the buffer | |
1014 | * was on was the disposal list | |
1015 | */ | |
1016 | if (!(bp->b_state & XFS_BSTATE_DISPOSE)) { | |
1017 | list_lru_del(&bp->b_target->bt_lru, &bp->b_lru); | |
1018 | } else { | |
1019 | ASSERT(list_empty(&bp->b_lru)); | |
1da177e4 | 1020 | } |
9c7504aa BF |
1021 | |
1022 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); | |
6031e73a LS |
1023 | rhashtable_remove_fast(&pag->pag_buf_hash, &bp->b_rhash_head, |
1024 | xfs_buf_hash_params); | |
9c7504aa BF |
1025 | spin_unlock(&pag->pag_buf_lock); |
1026 | xfs_perag_put(pag); | |
1027 | freebuf = true; | |
1da177e4 | 1028 | } |
9c7504aa BF |
1029 | |
1030 | out_unlock: | |
1031 | spin_unlock(&bp->b_lock); | |
1032 | ||
1033 | if (freebuf) | |
1034 | xfs_buf_free(bp); | |
1da177e4 LT |
1035 | } |
1036 | ||
1037 | ||
1038 | /* | |
0e6e847f | 1039 | * Lock a buffer object, if it is not already locked. |
90810b9e DC |
1040 | * |
1041 | * If we come across a stale, pinned, locked buffer, we know that we are | |
1042 | * being asked to lock a buffer that has been reallocated. Because it is | |
1043 | * pinned, we know that the log has not been pushed to disk and hence it | |
1044 | * will still be locked. Rather than continuing to have trylock attempts | |
1045 | * fail until someone else pushes the log, push it ourselves before | |
1046 | * returning. This means that the xfsaild will not get stuck trying | |
1047 | * to push on stale inode buffers. | |
1da177e4 LT |
1048 | */ |
1049 | int | |
0c842ad4 CH |
1050 | xfs_buf_trylock( |
1051 | struct xfs_buf *bp) | |
1da177e4 LT |
1052 | { |
1053 | int locked; | |
1054 | ||
ce8e922c | 1055 | locked = down_trylock(&bp->b_sema) == 0; |
fa6c668d | 1056 | if (locked) |
479c6412 | 1057 | trace_xfs_buf_trylock(bp, _RET_IP_); |
fa6c668d | 1058 | else |
479c6412 | 1059 | trace_xfs_buf_trylock_fail(bp, _RET_IP_); |
0c842ad4 | 1060 | return locked; |
1da177e4 | 1061 | } |
1da177e4 LT |
1062 | |
1063 | /* | |
0e6e847f | 1064 | * Lock a buffer object. |
ed3b4d6c DC |
1065 | * |
1066 | * If we come across a stale, pinned, locked buffer, we know that we | |
1067 | * are being asked to lock a buffer that has been reallocated. Because | |
1068 | * it is pinned, we know that the log has not been pushed to disk and | |
1069 | * hence it will still be locked. Rather than sleeping until someone | |
1070 | * else pushes the log, push it ourselves before trying to get the lock. | |
1da177e4 | 1071 | */ |
ce8e922c NS |
1072 | void |
1073 | xfs_buf_lock( | |
0c842ad4 | 1074 | struct xfs_buf *bp) |
1da177e4 | 1075 | { |
0b1b213f CH |
1076 | trace_xfs_buf_lock(bp, _RET_IP_); |
1077 | ||
ed3b4d6c | 1078 | if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
dbd329f1 | 1079 | xfs_log_force(bp->b_mount, 0); |
ce8e922c | 1080 | down(&bp->b_sema); |
0b1b213f CH |
1081 | |
1082 | trace_xfs_buf_lock_done(bp, _RET_IP_); | |
1da177e4 LT |
1083 | } |
1084 | ||
1da177e4 | 1085 | void |
ce8e922c | 1086 | xfs_buf_unlock( |
0c842ad4 | 1087 | struct xfs_buf *bp) |
1da177e4 | 1088 | { |
20e8a063 BF |
1089 | ASSERT(xfs_buf_islocked(bp)); |
1090 | ||
ce8e922c | 1091 | up(&bp->b_sema); |
0b1b213f | 1092 | trace_xfs_buf_unlock(bp, _RET_IP_); |
1da177e4 LT |
1093 | } |
1094 | ||
ce8e922c NS |
1095 | STATIC void |
1096 | xfs_buf_wait_unpin( | |
e8222613 | 1097 | struct xfs_buf *bp) |
1da177e4 LT |
1098 | { |
1099 | DECLARE_WAITQUEUE (wait, current); | |
1100 | ||
ce8e922c | 1101 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
1102 | return; |
1103 | ||
ce8e922c | 1104 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1105 | for (;;) { |
1106 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 1107 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 1108 | break; |
7eaceacc | 1109 | io_schedule(); |
1da177e4 | 1110 | } |
ce8e922c | 1111 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1112 | set_current_state(TASK_RUNNING); |
1113 | } | |
1114 | ||
f58d0ea9 CH |
1115 | static void |
1116 | xfs_buf_ioerror_alert_ratelimited( | |
664ffb8a CH |
1117 | struct xfs_buf *bp) |
1118 | { | |
664ffb8a CH |
1119 | static unsigned long lasttime; |
1120 | static struct xfs_buftarg *lasttarg; | |
1121 | ||
664ffb8a CH |
1122 | if (bp->b_target != lasttarg || |
1123 | time_after(jiffies, (lasttime + 5*HZ))) { | |
1124 | lasttime = jiffies; | |
1125 | xfs_buf_ioerror_alert(bp, __this_address); | |
1126 | } | |
1127 | lasttarg = bp->b_target; | |
664ffb8a CH |
1128 | } |
1129 | ||
664ffb8a CH |
1130 | /* |
1131 | * Account for this latest trip around the retry handler, and decide if | |
1132 | * we've failed enough times to constitute a permanent failure. | |
1133 | */ | |
1134 | static bool | |
1135 | xfs_buf_ioerror_permanent( | |
1136 | struct xfs_buf *bp, | |
1137 | struct xfs_error_cfg *cfg) | |
1138 | { | |
1139 | struct xfs_mount *mp = bp->b_mount; | |
1140 | ||
1141 | if (cfg->max_retries != XFS_ERR_RETRY_FOREVER && | |
1142 | ++bp->b_retries > cfg->max_retries) | |
1143 | return true; | |
1144 | if (cfg->retry_timeout != XFS_ERR_RETRY_FOREVER && | |
1145 | time_after(jiffies, cfg->retry_timeout + bp->b_first_retry_time)) | |
1146 | return true; | |
1147 | ||
1148 | /* At unmount we may treat errors differently */ | |
2e973b2c | 1149 | if (xfs_is_unmounting(mp) && mp->m_fail_unmount) |
664ffb8a CH |
1150 | return true; |
1151 | ||
1152 | return false; | |
1153 | } | |
1154 | ||
1155 | /* | |
1156 | * On a sync write or shutdown we just want to stale the buffer and let the | |
1157 | * caller handle the error in bp->b_error appropriately. | |
1158 | * | |
1159 | * If the write was asynchronous then no one will be looking for the error. If | |
1160 | * this is the first failure of this type, clear the error state and write the | |
1161 | * buffer out again. This means we always retry an async write failure at least | |
1162 | * once, but we also need to set the buffer up to behave correctly now for | |
1163 | * repeated failures. | |
1164 | * | |
1165 | * If we get repeated async write failures, then we take action according to the | |
1166 | * error configuration we have been set up to use. | |
1167 | * | |
70796c6b CH |
1168 | * Returns true if this function took care of error handling and the caller must |
1169 | * not touch the buffer again. Return false if the caller should proceed with | |
1170 | * normal I/O completion handling. | |
664ffb8a | 1171 | */ |
70796c6b CH |
1172 | static bool |
1173 | xfs_buf_ioend_handle_error( | |
664ffb8a CH |
1174 | struct xfs_buf *bp) |
1175 | { | |
1176 | struct xfs_mount *mp = bp->b_mount; | |
1177 | struct xfs_error_cfg *cfg; | |
1178 | ||
f58d0ea9 CH |
1179 | /* |
1180 | * If we've already decided to shutdown the filesystem because of I/O | |
1181 | * errors, there's no point in giving this a retry. | |
1182 | */ | |
75c8c50f | 1183 | if (xfs_is_shutdown(mp)) |
f58d0ea9 CH |
1184 | goto out_stale; |
1185 | ||
1186 | xfs_buf_ioerror_alert_ratelimited(bp); | |
1187 | ||
22c10589 CH |
1188 | /* |
1189 | * We're not going to bother about retrying this during recovery. | |
1190 | * One strike! | |
1191 | */ | |
1192 | if (bp->b_flags & _XBF_LOGRECOVERY) { | |
1193 | xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR); | |
1194 | return false; | |
1195 | } | |
1196 | ||
f58d0ea9 CH |
1197 | /* |
1198 | * Synchronous writes will have callers process the error. | |
1199 | */ | |
1200 | if (!(bp->b_flags & XBF_ASYNC)) | |
664ffb8a CH |
1201 | goto out_stale; |
1202 | ||
1203 | trace_xfs_buf_iodone_async(bp, _RET_IP_); | |
1204 | ||
1205 | cfg = xfs_error_get_cfg(mp, XFS_ERR_METADATA, bp->b_error); | |
3cc49884 CH |
1206 | if (bp->b_last_error != bp->b_error || |
1207 | !(bp->b_flags & (XBF_STALE | XBF_WRITE_FAIL))) { | |
1208 | bp->b_last_error = bp->b_error; | |
1209 | if (cfg->retry_timeout != XFS_ERR_RETRY_FOREVER && | |
1210 | !bp->b_first_retry_time) | |
1211 | bp->b_first_retry_time = jiffies; | |
1212 | goto resubmit; | |
664ffb8a CH |
1213 | } |
1214 | ||
1215 | /* | |
1216 | * Permanent error - we need to trigger a shutdown if we haven't already | |
1217 | * to indicate that inconsistency will result from this action. | |
1218 | */ | |
1219 | if (xfs_buf_ioerror_permanent(bp, cfg)) { | |
1220 | xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR); | |
1221 | goto out_stale; | |
1222 | } | |
1223 | ||
1224 | /* Still considered a transient error. Caller will schedule retries. */ | |
844c9358 CH |
1225 | if (bp->b_flags & _XBF_INODES) |
1226 | xfs_buf_inode_io_fail(bp); | |
1227 | else if (bp->b_flags & _XBF_DQUOTS) | |
1228 | xfs_buf_dquot_io_fail(bp); | |
1229 | else | |
1230 | ASSERT(list_empty(&bp->b_li_list)); | |
1231 | xfs_buf_ioerror(bp, 0); | |
1232 | xfs_buf_relse(bp); | |
70796c6b | 1233 | return true; |
664ffb8a | 1234 | |
3cc49884 CH |
1235 | resubmit: |
1236 | xfs_buf_ioerror(bp, 0); | |
55b7d711 | 1237 | bp->b_flags |= (XBF_DONE | XBF_WRITE_FAIL); |
3cc49884 | 1238 | xfs_buf_submit(bp); |
70796c6b | 1239 | return true; |
664ffb8a CH |
1240 | out_stale: |
1241 | xfs_buf_stale(bp); | |
1242 | bp->b_flags |= XBF_DONE; | |
55b7d711 | 1243 | bp->b_flags &= ~XBF_WRITE; |
664ffb8a | 1244 | trace_xfs_buf_error_relse(bp, _RET_IP_); |
70796c6b | 1245 | return false; |
664ffb8a | 1246 | } |
1da177e4 | 1247 | |
76b2d323 | 1248 | static void |
e8aaba9a DC |
1249 | xfs_buf_ioend( |
1250 | struct xfs_buf *bp) | |
1da177e4 | 1251 | { |
e8aaba9a | 1252 | trace_xfs_buf_iodone(bp, _RET_IP_); |
1813dd64 | 1253 | |
61be9c52 DC |
1254 | /* |
1255 | * Pull in IO completion errors now. We are guaranteed to be running | |
1256 | * single threaded, so we don't need the lock to read b_io_error. | |
1257 | */ | |
1258 | if (!bp->b_error && bp->b_io_error) | |
1259 | xfs_buf_ioerror(bp, bp->b_io_error); | |
1260 | ||
55b7d711 | 1261 | if (bp->b_flags & XBF_READ) { |
b01d1461 DC |
1262 | if (!bp->b_error && bp->b_ops) |
1263 | bp->b_ops->verify_read(bp); | |
1264 | if (!bp->b_error) | |
1265 | bp->b_flags |= XBF_DONE; | |
23fb5a93 CH |
1266 | } else { |
1267 | if (!bp->b_error) { | |
1268 | bp->b_flags &= ~XBF_WRITE_FAIL; | |
1269 | bp->b_flags |= XBF_DONE; | |
1270 | } | |
f593bf14 | 1271 | |
70796c6b | 1272 | if (unlikely(bp->b_error) && xfs_buf_ioend_handle_error(bp)) |
664ffb8a | 1273 | return; |
664ffb8a CH |
1274 | |
1275 | /* clear the retry state */ | |
1276 | bp->b_last_error = 0; | |
1277 | bp->b_retries = 0; | |
1278 | bp->b_first_retry_time = 0; | |
1279 | ||
1280 | /* | |
1281 | * Note that for things like remote attribute buffers, there may | |
1282 | * not be a buffer log item here, so processing the buffer log | |
1283 | * item must remain optional. | |
1284 | */ | |
1285 | if (bp->b_log_item) | |
1286 | xfs_buf_item_done(bp); | |
1287 | ||
23fb5a93 CH |
1288 | if (bp->b_flags & _XBF_INODES) |
1289 | xfs_buf_inode_iodone(bp); | |
1290 | else if (bp->b_flags & _XBF_DQUOTS) | |
1291 | xfs_buf_dquot_iodone(bp); | |
22c10589 | 1292 | |
0c7e5afb | 1293 | } |
6a7584b1 | 1294 | |
22c10589 CH |
1295 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD | |
1296 | _XBF_LOGRECOVERY); | |
55b7d711 | 1297 | |
6a7584b1 CH |
1298 | if (bp->b_flags & XBF_ASYNC) |
1299 | xfs_buf_relse(bp); | |
1300 | else | |
1301 | complete(&bp->b_iowait); | |
1da177e4 LT |
1302 | } |
1303 | ||
e8aaba9a DC |
1304 | static void |
1305 | xfs_buf_ioend_work( | |
1306 | struct work_struct *work) | |
1da177e4 | 1307 | { |
e8aaba9a | 1308 | struct xfs_buf *bp = |
e8222613 | 1309 | container_of(work, struct xfs_buf, b_ioend_work); |
0b1b213f | 1310 | |
e8aaba9a DC |
1311 | xfs_buf_ioend(bp); |
1312 | } | |
1da177e4 | 1313 | |
211fe1a4 | 1314 | static void |
e8aaba9a DC |
1315 | xfs_buf_ioend_async( |
1316 | struct xfs_buf *bp) | |
1317 | { | |
b29c70f5 | 1318 | INIT_WORK(&bp->b_ioend_work, xfs_buf_ioend_work); |
dbd329f1 | 1319 | queue_work(bp->b_mount->m_buf_workqueue, &bp->b_ioend_work); |
1da177e4 LT |
1320 | } |
1321 | ||
1da177e4 | 1322 | void |
31ca03c9 | 1323 | __xfs_buf_ioerror( |
e8222613 | 1324 | struct xfs_buf *bp, |
31ca03c9 DW |
1325 | int error, |
1326 | xfs_failaddr_t failaddr) | |
1da177e4 | 1327 | { |
2451337d DC |
1328 | ASSERT(error <= 0 && error >= -1000); |
1329 | bp->b_error = error; | |
31ca03c9 | 1330 | trace_xfs_buf_ioerror(bp, error, failaddr); |
1da177e4 LT |
1331 | } |
1332 | ||
901796af CH |
1333 | void |
1334 | xfs_buf_ioerror_alert( | |
1335 | struct xfs_buf *bp, | |
cdbcf82b | 1336 | xfs_failaddr_t func) |
901796af | 1337 | { |
f9bccfcc BF |
1338 | xfs_buf_alert_ratelimited(bp, "XFS: metadata IO error", |
1339 | "metadata I/O error in \"%pS\" at daddr 0x%llx len %d error %d", | |
04fcad80 | 1340 | func, (uint64_t)xfs_buf_daddr(bp), |
f9bccfcc | 1341 | bp->b_length, -bp->b_error); |
901796af CH |
1342 | } |
1343 | ||
54b3b1f6 BF |
1344 | /* |
1345 | * To simulate an I/O failure, the buffer must be locked and held with at least | |
1346 | * three references. The LRU reference is dropped by the stale call. The buf | |
1347 | * item reference is dropped via ioend processing. The third reference is owned | |
1348 | * by the caller and is dropped on I/O completion if the buffer is XBF_ASYNC. | |
1349 | */ | |
1350 | void | |
1351 | xfs_buf_ioend_fail( | |
1352 | struct xfs_buf *bp) | |
1353 | { | |
1354 | bp->b_flags &= ~XBF_DONE; | |
1355 | xfs_buf_stale(bp); | |
1356 | xfs_buf_ioerror(bp, -EIO); | |
1357 | xfs_buf_ioend(bp); | |
901796af CH |
1358 | } |
1359 | ||
a2dcf5df CH |
1360 | int |
1361 | xfs_bwrite( | |
1362 | struct xfs_buf *bp) | |
1363 | { | |
1364 | int error; | |
1365 | ||
1366 | ASSERT(xfs_buf_islocked(bp)); | |
1367 | ||
1368 | bp->b_flags |= XBF_WRITE; | |
27187754 | 1369 | bp->b_flags &= ~(XBF_ASYNC | XBF_READ | _XBF_DELWRI_Q | |
b6983e80 | 1370 | XBF_DONE); |
a2dcf5df | 1371 | |
6af88cda | 1372 | error = xfs_buf_submit(bp); |
dbd329f1 CH |
1373 | if (error) |
1374 | xfs_force_shutdown(bp->b_mount, SHUTDOWN_META_IO_ERROR); | |
a2dcf5df CH |
1375 | return error; |
1376 | } | |
1377 | ||
9bdd9bd6 | 1378 | static void |
ce8e922c | 1379 | xfs_buf_bio_end_io( |
4246a0b6 | 1380 | struct bio *bio) |
1da177e4 | 1381 | { |
9bdd9bd6 | 1382 | struct xfs_buf *bp = (struct xfs_buf *)bio->bi_private; |
1da177e4 | 1383 | |
7376d745 BF |
1384 | if (!bio->bi_status && |
1385 | (bp->b_flags & XBF_WRITE) && (bp->b_flags & XBF_ASYNC) && | |
43dc0aa8 | 1386 | XFS_TEST_ERROR(false, bp->b_mount, XFS_ERRTAG_BUF_IOERROR)) |
7376d745 | 1387 | bio->bi_status = BLK_STS_IOERR; |
1da177e4 | 1388 | |
37eb17e6 DC |
1389 | /* |
1390 | * don't overwrite existing errors - otherwise we can lose errors on | |
1391 | * buffers that require multiple bios to complete. | |
1392 | */ | |
4e4cbee9 CH |
1393 | if (bio->bi_status) { |
1394 | int error = blk_status_to_errno(bio->bi_status); | |
1395 | ||
1396 | cmpxchg(&bp->b_io_error, 0, error); | |
1397 | } | |
1da177e4 | 1398 | |
37eb17e6 | 1399 | if (!bp->b_error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ)) |
73c77e2c JB |
1400 | invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp)); |
1401 | ||
e8aaba9a DC |
1402 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) |
1403 | xfs_buf_ioend_async(bp); | |
1da177e4 | 1404 | bio_put(bio); |
1da177e4 LT |
1405 | } |
1406 | ||
3e85c868 DC |
1407 | static void |
1408 | xfs_buf_ioapply_map( | |
1409 | struct xfs_buf *bp, | |
1410 | int map, | |
1411 | int *buf_offset, | |
1412 | int *count, | |
2123ef85 | 1413 | int op) |
1da177e4 | 1414 | { |
3e85c868 | 1415 | int page_index; |
5f7136db | 1416 | unsigned int total_nr_pages = bp->b_page_count; |
3e85c868 DC |
1417 | int nr_pages; |
1418 | struct bio *bio; | |
1419 | sector_t sector = bp->b_maps[map].bm_bn; | |
1420 | int size; | |
1421 | int offset; | |
1da177e4 | 1422 | |
3e85c868 DC |
1423 | /* skip the pages in the buffer before the start offset */ |
1424 | page_index = 0; | |
1425 | offset = *buf_offset; | |
1426 | while (offset >= PAGE_SIZE) { | |
1427 | page_index++; | |
1428 | offset -= PAGE_SIZE; | |
f538d4da CH |
1429 | } |
1430 | ||
3e85c868 DC |
1431 | /* |
1432 | * Limit the IO size to the length of the current vector, and update the | |
1433 | * remaining IO count for the next time around. | |
1434 | */ | |
1435 | size = min_t(int, BBTOB(bp->b_maps[map].bm_len), *count); | |
1436 | *count -= size; | |
1437 | *buf_offset += size; | |
34951f5c | 1438 | |
1da177e4 | 1439 | next_chunk: |
ce8e922c | 1440 | atomic_inc(&bp->b_io_remaining); |
5f7136db | 1441 | nr_pages = bio_max_segs(total_nr_pages); |
1da177e4 LT |
1442 | |
1443 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
74d46992 | 1444 | bio_set_dev(bio, bp->b_target->bt_bdev); |
4f024f37 | 1445 | bio->bi_iter.bi_sector = sector; |
ce8e922c NS |
1446 | bio->bi_end_io = xfs_buf_bio_end_io; |
1447 | bio->bi_private = bp; | |
2123ef85 | 1448 | bio->bi_opf = op; |
0e6e847f | 1449 | |
3e85c868 | 1450 | for (; size && nr_pages; nr_pages--, page_index++) { |
0e6e847f | 1451 | int rbytes, nbytes = PAGE_SIZE - offset; |
1da177e4 LT |
1452 | |
1453 | if (nbytes > size) | |
1454 | nbytes = size; | |
1455 | ||
3e85c868 DC |
1456 | rbytes = bio_add_page(bio, bp->b_pages[page_index], nbytes, |
1457 | offset); | |
ce8e922c | 1458 | if (rbytes < nbytes) |
1da177e4 LT |
1459 | break; |
1460 | ||
1461 | offset = 0; | |
aa0e8833 | 1462 | sector += BTOBB(nbytes); |
1da177e4 LT |
1463 | size -= nbytes; |
1464 | total_nr_pages--; | |
1465 | } | |
1466 | ||
4f024f37 | 1467 | if (likely(bio->bi_iter.bi_size)) { |
73c77e2c JB |
1468 | if (xfs_buf_is_vmapped(bp)) { |
1469 | flush_kernel_vmap_range(bp->b_addr, | |
1470 | xfs_buf_vmap_len(bp)); | |
1471 | } | |
4e49ea4a | 1472 | submit_bio(bio); |
1da177e4 LT |
1473 | if (size) |
1474 | goto next_chunk; | |
1475 | } else { | |
37eb17e6 DC |
1476 | /* |
1477 | * This is guaranteed not to be the last io reference count | |
595bff75 | 1478 | * because the caller (xfs_buf_submit) holds a count itself. |
37eb17e6 DC |
1479 | */ |
1480 | atomic_dec(&bp->b_io_remaining); | |
2451337d | 1481 | xfs_buf_ioerror(bp, -EIO); |
ec53d1db | 1482 | bio_put(bio); |
1da177e4 | 1483 | } |
3e85c868 DC |
1484 | |
1485 | } | |
1486 | ||
1487 | STATIC void | |
1488 | _xfs_buf_ioapply( | |
1489 | struct xfs_buf *bp) | |
1490 | { | |
1491 | struct blk_plug plug; | |
50bfcd0c | 1492 | int op; |
3e85c868 DC |
1493 | int offset; |
1494 | int size; | |
1495 | int i; | |
1496 | ||
c163f9a1 DC |
1497 | /* |
1498 | * Make sure we capture only current IO errors rather than stale errors | |
1499 | * left over from previous use of the buffer (e.g. failed readahead). | |
1500 | */ | |
1501 | bp->b_error = 0; | |
1502 | ||
3e85c868 | 1503 | if (bp->b_flags & XBF_WRITE) { |
50bfcd0c | 1504 | op = REQ_OP_WRITE; |
1813dd64 DC |
1505 | |
1506 | /* | |
1507 | * Run the write verifier callback function if it exists. If | |
1508 | * this function fails it will mark the buffer with an error and | |
1509 | * the IO should not be dispatched. | |
1510 | */ | |
1511 | if (bp->b_ops) { | |
1512 | bp->b_ops->verify_write(bp); | |
1513 | if (bp->b_error) { | |
dbd329f1 | 1514 | xfs_force_shutdown(bp->b_mount, |
1813dd64 DC |
1515 | SHUTDOWN_CORRUPT_INCORE); |
1516 | return; | |
1517 | } | |
4c7f65ae | 1518 | } else if (bp->b_rhash_key != XFS_BUF_DADDR_NULL) { |
dbd329f1 | 1519 | struct xfs_mount *mp = bp->b_mount; |
400b9d88 DC |
1520 | |
1521 | /* | |
1522 | * non-crc filesystems don't attach verifiers during | |
1523 | * log recovery, so don't warn for such filesystems. | |
1524 | */ | |
38c26bfd | 1525 | if (xfs_has_crc(mp)) { |
400b9d88 | 1526 | xfs_warn(mp, |
c219b015 | 1527 | "%s: no buf ops on daddr 0x%llx len %d", |
4c7f65ae DC |
1528 | __func__, xfs_buf_daddr(bp), |
1529 | bp->b_length); | |
9c712a13 DW |
1530 | xfs_hex_dump(bp->b_addr, |
1531 | XFS_CORRUPTION_DUMP_LEN); | |
400b9d88 DC |
1532 | dump_stack(); |
1533 | } | |
1813dd64 | 1534 | } |
3e85c868 | 1535 | } else { |
50bfcd0c | 1536 | op = REQ_OP_READ; |
2123ef85 CH |
1537 | if (bp->b_flags & XBF_READ_AHEAD) |
1538 | op |= REQ_RAHEAD; | |
3e85c868 DC |
1539 | } |
1540 | ||
1541 | /* we only use the buffer cache for meta-data */ | |
2123ef85 | 1542 | op |= REQ_META; |
3e85c868 DC |
1543 | |
1544 | /* | |
1545 | * Walk all the vectors issuing IO on them. Set up the initial offset | |
1546 | * into the buffer and the desired IO size before we start - | |
1547 | * _xfs_buf_ioapply_vec() will modify them appropriately for each | |
1548 | * subsequent call. | |
1549 | */ | |
1550 | offset = bp->b_offset; | |
8124b9b6 | 1551 | size = BBTOB(bp->b_length); |
3e85c868 DC |
1552 | blk_start_plug(&plug); |
1553 | for (i = 0; i < bp->b_map_count; i++) { | |
2123ef85 | 1554 | xfs_buf_ioapply_map(bp, i, &offset, &size, op); |
3e85c868 DC |
1555 | if (bp->b_error) |
1556 | break; | |
1557 | if (size <= 0) | |
1558 | break; /* all done */ | |
1559 | } | |
1560 | blk_finish_plug(&plug); | |
1da177e4 LT |
1561 | } |
1562 | ||
595bff75 | 1563 | /* |
bb00b6f1 | 1564 | * Wait for I/O completion of a sync buffer and return the I/O error code. |
595bff75 | 1565 | */ |
eaebb515 | 1566 | static int |
bb00b6f1 | 1567 | xfs_buf_iowait( |
595bff75 | 1568 | struct xfs_buf *bp) |
1da177e4 | 1569 | { |
bb00b6f1 BF |
1570 | ASSERT(!(bp->b_flags & XBF_ASYNC)); |
1571 | ||
1572 | trace_xfs_buf_iowait(bp, _RET_IP_); | |
1573 | wait_for_completion(&bp->b_iowait); | |
1574 | trace_xfs_buf_iowait_done(bp, _RET_IP_); | |
1575 | ||
1576 | return bp->b_error; | |
1577 | } | |
1578 | ||
1579 | /* | |
1580 | * Buffer I/O submission path, read or write. Asynchronous submission transfers | |
1581 | * the buffer lock ownership and the current reference to the IO. It is not | |
1582 | * safe to reference the buffer after a call to this function unless the caller | |
1583 | * holds an additional reference itself. | |
1584 | */ | |
26e32875 | 1585 | static int |
bb00b6f1 BF |
1586 | __xfs_buf_submit( |
1587 | struct xfs_buf *bp, | |
1588 | bool wait) | |
1589 | { | |
1590 | int error = 0; | |
1591 | ||
595bff75 | 1592 | trace_xfs_buf_submit(bp, _RET_IP_); |
1da177e4 | 1593 | |
43ff2122 | 1594 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); |
595bff75 DC |
1595 | |
1596 | /* on shutdown we stale and complete the buffer immediately */ | |
75c8c50f | 1597 | if (xfs_is_shutdown(bp->b_mount)) { |
54b3b1f6 | 1598 | xfs_buf_ioend_fail(bp); |
eaebb515 | 1599 | return -EIO; |
595bff75 | 1600 | } |
1da177e4 | 1601 | |
bb00b6f1 BF |
1602 | /* |
1603 | * Grab a reference so the buffer does not go away underneath us. For | |
1604 | * async buffers, I/O completion drops the callers reference, which | |
1605 | * could occur before submission returns. | |
1606 | */ | |
1607 | xfs_buf_hold(bp); | |
1608 | ||
375ec69d | 1609 | if (bp->b_flags & XBF_WRITE) |
ce8e922c | 1610 | xfs_buf_wait_unpin(bp); |
e11bb805 | 1611 | |
61be9c52 DC |
1612 | /* clear the internal error state to avoid spurious errors */ |
1613 | bp->b_io_error = 0; | |
1614 | ||
8d6c1210 | 1615 | /* |
e11bb805 DC |
1616 | * Set the count to 1 initially, this will stop an I/O completion |
1617 | * callout which happens before we have started all the I/O from calling | |
1618 | * xfs_buf_ioend too early. | |
1da177e4 | 1619 | */ |
ce8e922c | 1620 | atomic_set(&bp->b_io_remaining, 1); |
eaebb515 BF |
1621 | if (bp->b_flags & XBF_ASYNC) |
1622 | xfs_buf_ioacct_inc(bp); | |
ce8e922c | 1623 | _xfs_buf_ioapply(bp); |
e11bb805 | 1624 | |
8d6c1210 | 1625 | /* |
595bff75 DC |
1626 | * If _xfs_buf_ioapply failed, we can get back here with only the IO |
1627 | * reference we took above. If we drop it to zero, run completion so | |
1628 | * that we don't return to the caller with completion still pending. | |
8d6c1210 | 1629 | */ |
e8aaba9a | 1630 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) { |
eaebb515 | 1631 | if (bp->b_error || !(bp->b_flags & XBF_ASYNC)) |
e8aaba9a DC |
1632 | xfs_buf_ioend(bp); |
1633 | else | |
1634 | xfs_buf_ioend_async(bp); | |
1635 | } | |
1da177e4 | 1636 | |
6af88cda BF |
1637 | if (wait) |
1638 | error = xfs_buf_iowait(bp); | |
bb00b6f1 | 1639 | |
595bff75 | 1640 | /* |
6af88cda BF |
1641 | * Release the hold that keeps the buffer referenced for the entire |
1642 | * I/O. Note that if the buffer is async, it is not safe to reference | |
1643 | * after this release. | |
595bff75 DC |
1644 | */ |
1645 | xfs_buf_rele(bp); | |
1646 | return error; | |
1da177e4 LT |
1647 | } |
1648 | ||
88ee2df7 | 1649 | void * |
ce8e922c | 1650 | xfs_buf_offset( |
88ee2df7 | 1651 | struct xfs_buf *bp, |
1da177e4 LT |
1652 | size_t offset) |
1653 | { | |
1654 | struct page *page; | |
1655 | ||
611c9946 | 1656 | if (bp->b_addr) |
62926044 | 1657 | return bp->b_addr + offset; |
1da177e4 | 1658 | |
0e6e847f | 1659 | page = bp->b_pages[offset >> PAGE_SHIFT]; |
88ee2df7 | 1660 | return page_address(page) + (offset & (PAGE_SIZE-1)); |
1da177e4 LT |
1661 | } |
1662 | ||
1da177e4 | 1663 | void |
f9a196ee CH |
1664 | xfs_buf_zero( |
1665 | struct xfs_buf *bp, | |
1666 | size_t boff, | |
1667 | size_t bsize) | |
1da177e4 | 1668 | { |
795cac72 | 1669 | size_t bend; |
1da177e4 LT |
1670 | |
1671 | bend = boff + bsize; | |
1672 | while (boff < bend) { | |
795cac72 DC |
1673 | struct page *page; |
1674 | int page_index, page_offset, csize; | |
1675 | ||
1676 | page_index = (boff + bp->b_offset) >> PAGE_SHIFT; | |
1677 | page_offset = (boff + bp->b_offset) & ~PAGE_MASK; | |
1678 | page = bp->b_pages[page_index]; | |
1679 | csize = min_t(size_t, PAGE_SIZE - page_offset, | |
8124b9b6 | 1680 | BBTOB(bp->b_length) - boff); |
1da177e4 | 1681 | |
795cac72 | 1682 | ASSERT((csize + page_offset) <= PAGE_SIZE); |
1da177e4 | 1683 | |
f9a196ee | 1684 | memset(page_address(page) + page_offset, 0, csize); |
1da177e4 LT |
1685 | |
1686 | boff += csize; | |
1da177e4 LT |
1687 | } |
1688 | } | |
1689 | ||
8d57c216 DW |
1690 | /* |
1691 | * Log a message about and stale a buffer that a caller has decided is corrupt. | |
1692 | * | |
1693 | * This function should be called for the kinds of metadata corruption that | |
1694 | * cannot be detect from a verifier, such as incorrect inter-block relationship | |
1695 | * data. Do /not/ call this function from a verifier function. | |
1696 | * | |
1697 | * The buffer must be XBF_DONE prior to the call. Afterwards, the buffer will | |
1698 | * be marked stale, but b_error will not be set. The caller is responsible for | |
1699 | * releasing the buffer or fixing it. | |
1700 | */ | |
1701 | void | |
1702 | __xfs_buf_mark_corrupt( | |
1703 | struct xfs_buf *bp, | |
1704 | xfs_failaddr_t fa) | |
1705 | { | |
1706 | ASSERT(bp->b_flags & XBF_DONE); | |
1707 | ||
e83cf875 | 1708 | xfs_buf_corruption_error(bp, fa); |
8d57c216 DW |
1709 | xfs_buf_stale(bp); |
1710 | } | |
1711 | ||
1da177e4 | 1712 | /* |
ce8e922c | 1713 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1714 | */ |
1715 | ||
1716 | /* | |
430cbeb8 DC |
1717 | * Wait for any bufs with callbacks that have been submitted but have not yet |
1718 | * returned. These buffers will have an elevated hold count, so wait on those | |
1719 | * while freeing all the buffers only held by the LRU. | |
1da177e4 | 1720 | */ |
e80dfa19 | 1721 | static enum lru_status |
10fb9ac1 | 1722 | xfs_buftarg_drain_rele( |
e80dfa19 | 1723 | struct list_head *item, |
3f97b163 | 1724 | struct list_lru_one *lru, |
e80dfa19 DC |
1725 | spinlock_t *lru_lock, |
1726 | void *arg) | |
1727 | ||
1da177e4 | 1728 | { |
e80dfa19 | 1729 | struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru); |
a4082357 | 1730 | struct list_head *dispose = arg; |
430cbeb8 | 1731 | |
e80dfa19 | 1732 | if (atomic_read(&bp->b_hold) > 1) { |
a4082357 | 1733 | /* need to wait, so skip it this pass */ |
10fb9ac1 | 1734 | trace_xfs_buf_drain_buftarg(bp, _RET_IP_); |
a4082357 | 1735 | return LRU_SKIP; |
1da177e4 | 1736 | } |
a4082357 DC |
1737 | if (!spin_trylock(&bp->b_lock)) |
1738 | return LRU_SKIP; | |
e80dfa19 | 1739 | |
a4082357 DC |
1740 | /* |
1741 | * clear the LRU reference count so the buffer doesn't get | |
1742 | * ignored in xfs_buf_rele(). | |
1743 | */ | |
1744 | atomic_set(&bp->b_lru_ref, 0); | |
1745 | bp->b_state |= XFS_BSTATE_DISPOSE; | |
3f97b163 | 1746 | list_lru_isolate_move(lru, item, dispose); |
a4082357 DC |
1747 | spin_unlock(&bp->b_lock); |
1748 | return LRU_REMOVED; | |
1da177e4 LT |
1749 | } |
1750 | ||
8321ddb2 BF |
1751 | /* |
1752 | * Wait for outstanding I/O on the buftarg to complete. | |
1753 | */ | |
e80dfa19 | 1754 | void |
8321ddb2 | 1755 | xfs_buftarg_wait( |
e80dfa19 DC |
1756 | struct xfs_buftarg *btp) |
1757 | { | |
85bec546 | 1758 | /* |
9c7504aa BF |
1759 | * First wait on the buftarg I/O count for all in-flight buffers to be |
1760 | * released. This is critical as new buffers do not make the LRU until | |
1761 | * they are released. | |
1762 | * | |
1763 | * Next, flush the buffer workqueue to ensure all completion processing | |
1764 | * has finished. Just waiting on buffer locks is not sufficient for | |
1765 | * async IO as the reference count held over IO is not released until | |
1766 | * after the buffer lock is dropped. Hence we need to ensure here that | |
1767 | * all reference counts have been dropped before we start walking the | |
1768 | * LRU list. | |
85bec546 | 1769 | */ |
9c7504aa BF |
1770 | while (percpu_counter_sum(&btp->bt_io_count)) |
1771 | delay(100); | |
800b2694 | 1772 | flush_workqueue(btp->bt_mount->m_buf_workqueue); |
8321ddb2 BF |
1773 | } |
1774 | ||
1775 | void | |
1776 | xfs_buftarg_drain( | |
1777 | struct xfs_buftarg *btp) | |
1778 | { | |
1779 | LIST_HEAD(dispose); | |
1780 | int loop = 0; | |
1781 | bool write_fail = false; | |
1782 | ||
1783 | xfs_buftarg_wait(btp); | |
85bec546 | 1784 | |
a4082357 DC |
1785 | /* loop until there is nothing left on the lru list. */ |
1786 | while (list_lru_count(&btp->bt_lru)) { | |
10fb9ac1 | 1787 | list_lru_walk(&btp->bt_lru, xfs_buftarg_drain_rele, |
a4082357 DC |
1788 | &dispose, LONG_MAX); |
1789 | ||
1790 | while (!list_empty(&dispose)) { | |
1791 | struct xfs_buf *bp; | |
1792 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); | |
1793 | list_del_init(&bp->b_lru); | |
ac8809f9 | 1794 | if (bp->b_flags & XBF_WRITE_FAIL) { |
61948b6f BF |
1795 | write_fail = true; |
1796 | xfs_buf_alert_ratelimited(bp, | |
1797 | "XFS: Corruption Alert", | |
c219b015 | 1798 | "Corruption Alert: Buffer at daddr 0x%llx had permanent write failures!", |
4c7f65ae | 1799 | (long long)xfs_buf_daddr(bp)); |
ac8809f9 | 1800 | } |
a4082357 DC |
1801 | xfs_buf_rele(bp); |
1802 | } | |
1803 | if (loop++ != 0) | |
1804 | delay(100); | |
1805 | } | |
61948b6f BF |
1806 | |
1807 | /* | |
1808 | * If one or more failed buffers were freed, that means dirty metadata | |
1809 | * was thrown away. This should only ever happen after I/O completion | |
1810 | * handling has elevated I/O error(s) to permanent failures and shuts | |
1811 | * down the fs. | |
1812 | */ | |
1813 | if (write_fail) { | |
75c8c50f | 1814 | ASSERT(xfs_is_shutdown(btp->bt_mount)); |
61948b6f BF |
1815 | xfs_alert(btp->bt_mount, |
1816 | "Please run xfs_repair to determine the extent of the problem."); | |
1817 | } | |
e80dfa19 DC |
1818 | } |
1819 | ||
1820 | static enum lru_status | |
1821 | xfs_buftarg_isolate( | |
1822 | struct list_head *item, | |
3f97b163 | 1823 | struct list_lru_one *lru, |
e80dfa19 DC |
1824 | spinlock_t *lru_lock, |
1825 | void *arg) | |
1826 | { | |
1827 | struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru); | |
1828 | struct list_head *dispose = arg; | |
1829 | ||
a4082357 DC |
1830 | /* |
1831 | * we are inverting the lru lock/bp->b_lock here, so use a trylock. | |
1832 | * If we fail to get the lock, just skip it. | |
1833 | */ | |
1834 | if (!spin_trylock(&bp->b_lock)) | |
1835 | return LRU_SKIP; | |
e80dfa19 DC |
1836 | /* |
1837 | * Decrement the b_lru_ref count unless the value is already | |
1838 | * zero. If the value is already zero, we need to reclaim the | |
1839 | * buffer, otherwise it gets another trip through the LRU. | |
1840 | */ | |
19957a18 | 1841 | if (atomic_add_unless(&bp->b_lru_ref, -1, 0)) { |
a4082357 | 1842 | spin_unlock(&bp->b_lock); |
e80dfa19 | 1843 | return LRU_ROTATE; |
a4082357 | 1844 | } |
e80dfa19 | 1845 | |
a4082357 | 1846 | bp->b_state |= XFS_BSTATE_DISPOSE; |
3f97b163 | 1847 | list_lru_isolate_move(lru, item, dispose); |
a4082357 | 1848 | spin_unlock(&bp->b_lock); |
e80dfa19 DC |
1849 | return LRU_REMOVED; |
1850 | } | |
1851 | ||
addbda40 | 1852 | static unsigned long |
e80dfa19 | 1853 | xfs_buftarg_shrink_scan( |
ff57ab21 | 1854 | struct shrinker *shrink, |
1495f230 | 1855 | struct shrink_control *sc) |
a6867a68 | 1856 | { |
ff57ab21 DC |
1857 | struct xfs_buftarg *btp = container_of(shrink, |
1858 | struct xfs_buftarg, bt_shrinker); | |
430cbeb8 | 1859 | LIST_HEAD(dispose); |
addbda40 | 1860 | unsigned long freed; |
430cbeb8 | 1861 | |
503c358c VD |
1862 | freed = list_lru_shrink_walk(&btp->bt_lru, sc, |
1863 | xfs_buftarg_isolate, &dispose); | |
430cbeb8 DC |
1864 | |
1865 | while (!list_empty(&dispose)) { | |
e80dfa19 | 1866 | struct xfs_buf *bp; |
430cbeb8 DC |
1867 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); |
1868 | list_del_init(&bp->b_lru); | |
1869 | xfs_buf_rele(bp); | |
1870 | } | |
1871 | ||
e80dfa19 DC |
1872 | return freed; |
1873 | } | |
1874 | ||
addbda40 | 1875 | static unsigned long |
e80dfa19 DC |
1876 | xfs_buftarg_shrink_count( |
1877 | struct shrinker *shrink, | |
1878 | struct shrink_control *sc) | |
1879 | { | |
1880 | struct xfs_buftarg *btp = container_of(shrink, | |
1881 | struct xfs_buftarg, bt_shrinker); | |
503c358c | 1882 | return list_lru_shrink_count(&btp->bt_lru, sc); |
a6867a68 DC |
1883 | } |
1884 | ||
1da177e4 LT |
1885 | void |
1886 | xfs_free_buftarg( | |
b7963133 | 1887 | struct xfs_buftarg *btp) |
1da177e4 | 1888 | { |
ff57ab21 | 1889 | unregister_shrinker(&btp->bt_shrinker); |
9c7504aa BF |
1890 | ASSERT(percpu_counter_sum(&btp->bt_io_count) == 0); |
1891 | percpu_counter_destroy(&btp->bt_io_count); | |
f5e1dd34 | 1892 | list_lru_destroy(&btp->bt_lru); |
ff57ab21 | 1893 | |
b5071ada | 1894 | blkdev_issue_flush(btp->bt_bdev); |
a6867a68 | 1895 | |
f0e2d93c | 1896 | kmem_free(btp); |
1da177e4 LT |
1897 | } |
1898 | ||
3fefdeee ES |
1899 | int |
1900 | xfs_setsize_buftarg( | |
1da177e4 | 1901 | xfs_buftarg_t *btp, |
3fefdeee | 1902 | unsigned int sectorsize) |
1da177e4 | 1903 | { |
7c71ee78 | 1904 | /* Set up metadata sector size info */ |
6da54179 ES |
1905 | btp->bt_meta_sectorsize = sectorsize; |
1906 | btp->bt_meta_sectormask = sectorsize - 1; | |
1da177e4 | 1907 | |
ce8e922c | 1908 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
4f10700a | 1909 | xfs_warn(btp->bt_mount, |
a1c6f057 DM |
1910 | "Cannot set_blocksize to %u on device %pg", |
1911 | sectorsize, btp->bt_bdev); | |
2451337d | 1912 | return -EINVAL; |
1da177e4 LT |
1913 | } |
1914 | ||
7c71ee78 ES |
1915 | /* Set up device logical sector size mask */ |
1916 | btp->bt_logical_sectorsize = bdev_logical_block_size(btp->bt_bdev); | |
1917 | btp->bt_logical_sectormask = bdev_logical_block_size(btp->bt_bdev) - 1; | |
1918 | ||
1da177e4 LT |
1919 | return 0; |
1920 | } | |
1921 | ||
1922 | /* | |
3fefdeee ES |
1923 | * When allocating the initial buffer target we have not yet |
1924 | * read in the superblock, so don't know what sized sectors | |
1925 | * are being used at this early stage. Play safe. | |
ce8e922c | 1926 | */ |
1da177e4 LT |
1927 | STATIC int |
1928 | xfs_setsize_buftarg_early( | |
1929 | xfs_buftarg_t *btp, | |
1930 | struct block_device *bdev) | |
1931 | { | |
a96c4151 | 1932 | return xfs_setsize_buftarg(btp, bdev_logical_block_size(bdev)); |
1da177e4 LT |
1933 | } |
1934 | ||
1da177e4 LT |
1935 | xfs_buftarg_t * |
1936 | xfs_alloc_buftarg( | |
ebad861b | 1937 | struct xfs_mount *mp, |
486aff5e DW |
1938 | struct block_device *bdev, |
1939 | struct dax_device *dax_dev) | |
1da177e4 LT |
1940 | { |
1941 | xfs_buftarg_t *btp; | |
1942 | ||
707e0dda | 1943 | btp = kmem_zalloc(sizeof(*btp), KM_NOFS); |
1da177e4 | 1944 | |
ebad861b | 1945 | btp->bt_mount = mp; |
ce8e922c NS |
1946 | btp->bt_dev = bdev->bd_dev; |
1947 | btp->bt_bdev = bdev; | |
486aff5e | 1948 | btp->bt_daxdev = dax_dev; |
0e6e847f | 1949 | |
f9bccfcc BF |
1950 | /* |
1951 | * Buffer IO error rate limiting. Limit it to no more than 10 messages | |
1952 | * per 30 seconds so as to not spam logs too much on repeated errors. | |
1953 | */ | |
1954 | ratelimit_state_init(&btp->bt_ioerror_rl, 30 * HZ, | |
1955 | DEFAULT_RATELIMIT_BURST); | |
1956 | ||
1da177e4 | 1957 | if (xfs_setsize_buftarg_early(btp, bdev)) |
d210a987 | 1958 | goto error_free; |
5ca302c8 GC |
1959 | |
1960 | if (list_lru_init(&btp->bt_lru)) | |
d210a987 | 1961 | goto error_free; |
5ca302c8 | 1962 | |
9c7504aa | 1963 | if (percpu_counter_init(&btp->bt_io_count, 0, GFP_KERNEL)) |
d210a987 | 1964 | goto error_lru; |
9c7504aa | 1965 | |
e80dfa19 DC |
1966 | btp->bt_shrinker.count_objects = xfs_buftarg_shrink_count; |
1967 | btp->bt_shrinker.scan_objects = xfs_buftarg_shrink_scan; | |
ff57ab21 | 1968 | btp->bt_shrinker.seeks = DEFAULT_SEEKS; |
e80dfa19 | 1969 | btp->bt_shrinker.flags = SHRINKER_NUMA_AWARE; |
d210a987 MH |
1970 | if (register_shrinker(&btp->bt_shrinker)) |
1971 | goto error_pcpu; | |
1da177e4 LT |
1972 | return btp; |
1973 | ||
d210a987 MH |
1974 | error_pcpu: |
1975 | percpu_counter_destroy(&btp->bt_io_count); | |
1976 | error_lru: | |
1977 | list_lru_destroy(&btp->bt_lru); | |
1978 | error_free: | |
f0e2d93c | 1979 | kmem_free(btp); |
1da177e4 LT |
1980 | return NULL; |
1981 | } | |
1982 | ||
20e8a063 BF |
1983 | /* |
1984 | * Cancel a delayed write list. | |
1985 | * | |
1986 | * Remove each buffer from the list, clear the delwri queue flag and drop the | |
1987 | * associated buffer reference. | |
1988 | */ | |
1989 | void | |
1990 | xfs_buf_delwri_cancel( | |
1991 | struct list_head *list) | |
1992 | { | |
1993 | struct xfs_buf *bp; | |
1994 | ||
1995 | while (!list_empty(list)) { | |
1996 | bp = list_first_entry(list, struct xfs_buf, b_list); | |
1997 | ||
1998 | xfs_buf_lock(bp); | |
1999 | bp->b_flags &= ~_XBF_DELWRI_Q; | |
2000 | list_del_init(&bp->b_list); | |
2001 | xfs_buf_relse(bp); | |
2002 | } | |
2003 | } | |
2004 | ||
1da177e4 | 2005 | /* |
43ff2122 CH |
2006 | * Add a buffer to the delayed write list. |
2007 | * | |
2008 | * This queues a buffer for writeout if it hasn't already been. Note that | |
2009 | * neither this routine nor the buffer list submission functions perform | |
2010 | * any internal synchronization. It is expected that the lists are thread-local | |
2011 | * to the callers. | |
2012 | * | |
2013 | * Returns true if we queued up the buffer, or false if it already had | |
2014 | * been on the buffer list. | |
1da177e4 | 2015 | */ |
43ff2122 | 2016 | bool |
ce8e922c | 2017 | xfs_buf_delwri_queue( |
43ff2122 CH |
2018 | struct xfs_buf *bp, |
2019 | struct list_head *list) | |
1da177e4 | 2020 | { |
43ff2122 | 2021 | ASSERT(xfs_buf_islocked(bp)); |
5a8ee6ba | 2022 | ASSERT(!(bp->b_flags & XBF_READ)); |
1da177e4 | 2023 | |
43ff2122 CH |
2024 | /* |
2025 | * If the buffer is already marked delwri it already is queued up | |
2026 | * by someone else for imediate writeout. Just ignore it in that | |
2027 | * case. | |
2028 | */ | |
2029 | if (bp->b_flags & _XBF_DELWRI_Q) { | |
2030 | trace_xfs_buf_delwri_queued(bp, _RET_IP_); | |
2031 | return false; | |
1da177e4 | 2032 | } |
1da177e4 | 2033 | |
43ff2122 | 2034 | trace_xfs_buf_delwri_queue(bp, _RET_IP_); |
d808f617 DC |
2035 | |
2036 | /* | |
43ff2122 CH |
2037 | * If a buffer gets written out synchronously or marked stale while it |
2038 | * is on a delwri list we lazily remove it. To do this, the other party | |
2039 | * clears the _XBF_DELWRI_Q flag but otherwise leaves the buffer alone. | |
2040 | * It remains referenced and on the list. In a rare corner case it | |
2041 | * might get readded to a delwri list after the synchronous writeout, in | |
2042 | * which case we need just need to re-add the flag here. | |
d808f617 | 2043 | */ |
43ff2122 CH |
2044 | bp->b_flags |= _XBF_DELWRI_Q; |
2045 | if (list_empty(&bp->b_list)) { | |
2046 | atomic_inc(&bp->b_hold); | |
2047 | list_add_tail(&bp->b_list, list); | |
585e6d88 | 2048 | } |
585e6d88 | 2049 | |
43ff2122 | 2050 | return true; |
585e6d88 DC |
2051 | } |
2052 | ||
089716aa DC |
2053 | /* |
2054 | * Compare function is more complex than it needs to be because | |
2055 | * the return value is only 32 bits and we are doing comparisons | |
2056 | * on 64 bit values | |
2057 | */ | |
2058 | static int | |
2059 | xfs_buf_cmp( | |
4f0f586b ST |
2060 | void *priv, |
2061 | const struct list_head *a, | |
2062 | const struct list_head *b) | |
089716aa DC |
2063 | { |
2064 | struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list); | |
2065 | struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); | |
2066 | xfs_daddr_t diff; | |
2067 | ||
f4b42421 | 2068 | diff = ap->b_maps[0].bm_bn - bp->b_maps[0].bm_bn; |
089716aa DC |
2069 | if (diff < 0) |
2070 | return -1; | |
2071 | if (diff > 0) | |
2072 | return 1; | |
2073 | return 0; | |
2074 | } | |
2075 | ||
26f1fe85 | 2076 | /* |
e339dd8d BF |
2077 | * Submit buffers for write. If wait_list is specified, the buffers are |
2078 | * submitted using sync I/O and placed on the wait list such that the caller can | |
2079 | * iowait each buffer. Otherwise async I/O is used and the buffers are released | |
2080 | * at I/O completion time. In either case, buffers remain locked until I/O | |
2081 | * completes and the buffer is released from the queue. | |
26f1fe85 | 2082 | */ |
43ff2122 | 2083 | static int |
26f1fe85 | 2084 | xfs_buf_delwri_submit_buffers( |
43ff2122 | 2085 | struct list_head *buffer_list, |
26f1fe85 | 2086 | struct list_head *wait_list) |
1da177e4 | 2087 | { |
43ff2122 CH |
2088 | struct xfs_buf *bp, *n; |
2089 | int pinned = 0; | |
26f1fe85 | 2090 | struct blk_plug plug; |
43ff2122 | 2091 | |
26f1fe85 | 2092 | list_sort(NULL, buffer_list, xfs_buf_cmp); |
43ff2122 | 2093 | |
26f1fe85 | 2094 | blk_start_plug(&plug); |
43ff2122 | 2095 | list_for_each_entry_safe(bp, n, buffer_list, b_list) { |
26f1fe85 | 2096 | if (!wait_list) { |
43ff2122 CH |
2097 | if (xfs_buf_ispinned(bp)) { |
2098 | pinned++; | |
2099 | continue; | |
2100 | } | |
2101 | if (!xfs_buf_trylock(bp)) | |
2102 | continue; | |
2103 | } else { | |
2104 | xfs_buf_lock(bp); | |
2105 | } | |
978c7b2f | 2106 | |
43ff2122 CH |
2107 | /* |
2108 | * Someone else might have written the buffer synchronously or | |
2109 | * marked it stale in the meantime. In that case only the | |
2110 | * _XBF_DELWRI_Q flag got cleared, and we have to drop the | |
2111 | * reference and remove it from the list here. | |
2112 | */ | |
2113 | if (!(bp->b_flags & _XBF_DELWRI_Q)) { | |
2114 | list_del_init(&bp->b_list); | |
2115 | xfs_buf_relse(bp); | |
2116 | continue; | |
2117 | } | |
c9c12971 | 2118 | |
43ff2122 | 2119 | trace_xfs_buf_delwri_split(bp, _RET_IP_); |
a1b7ea5d | 2120 | |
cf53e99d | 2121 | /* |
e339dd8d BF |
2122 | * If we have a wait list, each buffer (and associated delwri |
2123 | * queue reference) transfers to it and is submitted | |
2124 | * synchronously. Otherwise, drop the buffer from the delwri | |
2125 | * queue and submit async. | |
cf53e99d | 2126 | */ |
b6983e80 | 2127 | bp->b_flags &= ~_XBF_DELWRI_Q; |
e339dd8d | 2128 | bp->b_flags |= XBF_WRITE; |
26f1fe85 | 2129 | if (wait_list) { |
e339dd8d | 2130 | bp->b_flags &= ~XBF_ASYNC; |
26f1fe85 | 2131 | list_move_tail(&bp->b_list, wait_list); |
e339dd8d BF |
2132 | } else { |
2133 | bp->b_flags |= XBF_ASYNC; | |
ce8e922c | 2134 | list_del_init(&bp->b_list); |
e339dd8d | 2135 | } |
6af88cda | 2136 | __xfs_buf_submit(bp, false); |
43ff2122 CH |
2137 | } |
2138 | blk_finish_plug(&plug); | |
1da177e4 | 2139 | |
43ff2122 | 2140 | return pinned; |
1da177e4 LT |
2141 | } |
2142 | ||
2143 | /* | |
43ff2122 CH |
2144 | * Write out a buffer list asynchronously. |
2145 | * | |
2146 | * This will take the @buffer_list, write all non-locked and non-pinned buffers | |
2147 | * out and not wait for I/O completion on any of the buffers. This interface | |
2148 | * is only safely useable for callers that can track I/O completion by higher | |
2149 | * level means, e.g. AIL pushing as the @buffer_list is consumed in this | |
2150 | * function. | |
efc3289c BF |
2151 | * |
2152 | * Note: this function will skip buffers it would block on, and in doing so | |
2153 | * leaves them on @buffer_list so they can be retried on a later pass. As such, | |
2154 | * it is up to the caller to ensure that the buffer list is fully submitted or | |
2155 | * cancelled appropriately when they are finished with the list. Failure to | |
2156 | * cancel or resubmit the list until it is empty will result in leaked buffers | |
2157 | * at unmount time. | |
1da177e4 LT |
2158 | */ |
2159 | int | |
43ff2122 CH |
2160 | xfs_buf_delwri_submit_nowait( |
2161 | struct list_head *buffer_list) | |
1da177e4 | 2162 | { |
26f1fe85 | 2163 | return xfs_buf_delwri_submit_buffers(buffer_list, NULL); |
43ff2122 | 2164 | } |
1da177e4 | 2165 | |
43ff2122 CH |
2166 | /* |
2167 | * Write out a buffer list synchronously. | |
2168 | * | |
2169 | * This will take the @buffer_list, write all buffers out and wait for I/O | |
2170 | * completion on all of the buffers. @buffer_list is consumed by the function, | |
2171 | * so callers must have some other way of tracking buffers if they require such | |
2172 | * functionality. | |
2173 | */ | |
2174 | int | |
2175 | xfs_buf_delwri_submit( | |
2176 | struct list_head *buffer_list) | |
2177 | { | |
26f1fe85 | 2178 | LIST_HEAD (wait_list); |
43ff2122 CH |
2179 | int error = 0, error2; |
2180 | struct xfs_buf *bp; | |
1da177e4 | 2181 | |
26f1fe85 | 2182 | xfs_buf_delwri_submit_buffers(buffer_list, &wait_list); |
1da177e4 | 2183 | |
43ff2122 | 2184 | /* Wait for IO to complete. */ |
26f1fe85 DC |
2185 | while (!list_empty(&wait_list)) { |
2186 | bp = list_first_entry(&wait_list, struct xfs_buf, b_list); | |
a1b7ea5d | 2187 | |
089716aa | 2188 | list_del_init(&bp->b_list); |
cf53e99d | 2189 | |
e339dd8d BF |
2190 | /* |
2191 | * Wait on the locked buffer, check for errors and unlock and | |
2192 | * release the delwri queue reference. | |
2193 | */ | |
2194 | error2 = xfs_buf_iowait(bp); | |
43ff2122 CH |
2195 | xfs_buf_relse(bp); |
2196 | if (!error) | |
2197 | error = error2; | |
1da177e4 LT |
2198 | } |
2199 | ||
43ff2122 | 2200 | return error; |
1da177e4 LT |
2201 | } |
2202 | ||
7912e7fe BF |
2203 | /* |
2204 | * Push a single buffer on a delwri queue. | |
2205 | * | |
2206 | * The purpose of this function is to submit a single buffer of a delwri queue | |
2207 | * and return with the buffer still on the original queue. The waiting delwri | |
2208 | * buffer submission infrastructure guarantees transfer of the delwri queue | |
2209 | * buffer reference to a temporary wait list. We reuse this infrastructure to | |
2210 | * transfer the buffer back to the original queue. | |
2211 | * | |
2212 | * Note the buffer transitions from the queued state, to the submitted and wait | |
2213 | * listed state and back to the queued state during this call. The buffer | |
2214 | * locking and queue management logic between _delwri_pushbuf() and | |
2215 | * _delwri_queue() guarantee that the buffer cannot be queued to another list | |
2216 | * before returning. | |
2217 | */ | |
2218 | int | |
2219 | xfs_buf_delwri_pushbuf( | |
2220 | struct xfs_buf *bp, | |
2221 | struct list_head *buffer_list) | |
2222 | { | |
2223 | LIST_HEAD (submit_list); | |
2224 | int error; | |
2225 | ||
2226 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
2227 | ||
2228 | trace_xfs_buf_delwri_pushbuf(bp, _RET_IP_); | |
2229 | ||
2230 | /* | |
2231 | * Isolate the buffer to a new local list so we can submit it for I/O | |
2232 | * independently from the rest of the original list. | |
2233 | */ | |
2234 | xfs_buf_lock(bp); | |
2235 | list_move(&bp->b_list, &submit_list); | |
2236 | xfs_buf_unlock(bp); | |
2237 | ||
2238 | /* | |
2239 | * Delwri submission clears the DELWRI_Q buffer flag and returns with | |
e339dd8d | 2240 | * the buffer on the wait list with the original reference. Rather than |
7912e7fe BF |
2241 | * bounce the buffer from a local wait list back to the original list |
2242 | * after I/O completion, reuse the original list as the wait list. | |
2243 | */ | |
2244 | xfs_buf_delwri_submit_buffers(&submit_list, buffer_list); | |
2245 | ||
2246 | /* | |
e339dd8d BF |
2247 | * The buffer is now locked, under I/O and wait listed on the original |
2248 | * delwri queue. Wait for I/O completion, restore the DELWRI_Q flag and | |
2249 | * return with the buffer unlocked and on the original queue. | |
7912e7fe | 2250 | */ |
e339dd8d | 2251 | error = xfs_buf_iowait(bp); |
7912e7fe BF |
2252 | bp->b_flags |= _XBF_DELWRI_Q; |
2253 | xfs_buf_unlock(bp); | |
2254 | ||
2255 | return error; | |
2256 | } | |
2257 | ||
04d8b284 | 2258 | int __init |
ce8e922c | 2259 | xfs_buf_init(void) |
1da177e4 | 2260 | { |
12eba65b DC |
2261 | xfs_buf_zone = kmem_cache_create("xfs_buf", sizeof(struct xfs_buf), 0, |
2262 | SLAB_HWCACHE_ALIGN | | |
2263 | SLAB_RECLAIM_ACCOUNT | | |
2264 | SLAB_MEM_SPREAD, | |
2265 | NULL); | |
ce8e922c | 2266 | if (!xfs_buf_zone) |
0b1b213f | 2267 | goto out; |
04d8b284 | 2268 | |
23ea4032 | 2269 | return 0; |
1da177e4 | 2270 | |
0b1b213f | 2271 | out: |
8758280f | 2272 | return -ENOMEM; |
1da177e4 LT |
2273 | } |
2274 | ||
1da177e4 | 2275 | void |
ce8e922c | 2276 | xfs_buf_terminate(void) |
1da177e4 | 2277 | { |
aaf54eb8 | 2278 | kmem_cache_destroy(xfs_buf_zone); |
1da177e4 | 2279 | } |
7561d27e BF |
2280 | |
2281 | void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref) | |
2282 | { | |
7561d27e BF |
2283 | /* |
2284 | * Set the lru reference count to 0 based on the error injection tag. | |
2285 | * This allows userspace to disrupt buffer caching for debug/testing | |
2286 | * purposes. | |
2287 | */ | |
dbd329f1 | 2288 | if (XFS_TEST_ERROR(false, bp->b_mount, XFS_ERRTAG_BUF_LRU_REF)) |
7561d27e BF |
2289 | lru_ref = 0; |
2290 | ||
2291 | atomic_set(&bp->b_lru_ref, lru_ref); | |
2292 | } | |
8473fee3 BF |
2293 | |
2294 | /* | |
2295 | * Verify an on-disk magic value against the magic value specified in the | |
2296 | * verifier structure. The verifier magic is in disk byte order so the caller is | |
2297 | * expected to pass the value directly from disk. | |
2298 | */ | |
2299 | bool | |
2300 | xfs_verify_magic( | |
2301 | struct xfs_buf *bp, | |
15baadf7 | 2302 | __be32 dmagic) |
8473fee3 | 2303 | { |
dbd329f1 | 2304 | struct xfs_mount *mp = bp->b_mount; |
8473fee3 BF |
2305 | int idx; |
2306 | ||
38c26bfd | 2307 | idx = xfs_has_crc(mp); |
14ed8688 | 2308 | if (WARN_ON(!bp->b_ops || !bp->b_ops->magic[idx])) |
8473fee3 BF |
2309 | return false; |
2310 | return dmagic == bp->b_ops->magic[idx]; | |
2311 | } | |
15baadf7 DW |
2312 | /* |
2313 | * Verify an on-disk magic value against the magic value specified in the | |
2314 | * verifier structure. The verifier magic is in disk byte order so the caller is | |
2315 | * expected to pass the value directly from disk. | |
2316 | */ | |
2317 | bool | |
2318 | xfs_verify_magic16( | |
2319 | struct xfs_buf *bp, | |
2320 | __be16 dmagic) | |
2321 | { | |
dbd329f1 | 2322 | struct xfs_mount *mp = bp->b_mount; |
15baadf7 DW |
2323 | int idx; |
2324 | ||
38c26bfd | 2325 | idx = xfs_has_crc(mp); |
14ed8688 | 2326 | if (WARN_ON(!bp->b_ops || !bp->b_ops->magic16[idx])) |
15baadf7 DW |
2327 | return false; |
2328 | return dmagic == bp->b_ops->magic16[idx]; | |
2329 | } |