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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> |
6f643c57 | 8 | #include <linux/dax.h> |
1da177e4 | 9 | |
5467b34b | 10 | #include "xfs_shared.h" |
4fb6e8ad | 11 | #include "xfs_format.h" |
239880ef | 12 | #include "xfs_log_format.h" |
7fd36c44 | 13 | #include "xfs_trans_resv.h" |
b7963133 | 14 | #include "xfs_mount.h" |
0b1b213f | 15 | #include "xfs_trace.h" |
239880ef | 16 | #include "xfs_log.h" |
9fe5c77c | 17 | #include "xfs_log_recover.h" |
01728b44 | 18 | #include "xfs_log_priv.h" |
f593bf14 DC |
19 | #include "xfs_trans.h" |
20 | #include "xfs_buf_item.h" | |
e9e899a2 | 21 | #include "xfs_errortag.h" |
7561d27e | 22 | #include "xfs_error.h" |
9bbafc71 | 23 | #include "xfs_ag.h" |
b7963133 | 24 | |
231f91ab | 25 | struct kmem_cache *xfs_buf_cache; |
23ea4032 | 26 | |
37fd1678 DC |
27 | /* |
28 | * Locking orders | |
29 | * | |
30 | * xfs_buf_ioacct_inc: | |
31 | * xfs_buf_ioacct_dec: | |
32 | * b_sema (caller holds) | |
33 | * b_lock | |
34 | * | |
35 | * xfs_buf_stale: | |
36 | * b_sema (caller holds) | |
37 | * b_lock | |
38 | * lru_lock | |
39 | * | |
40 | * xfs_buf_rele: | |
41 | * b_lock | |
42 | * pag_buf_lock | |
43 | * lru_lock | |
44 | * | |
10fb9ac1 | 45 | * xfs_buftarg_drain_rele |
37fd1678 DC |
46 | * lru_lock |
47 | * b_lock (trylock due to inversion) | |
48 | * | |
49 | * xfs_buftarg_isolate | |
50 | * lru_lock | |
51 | * b_lock (trylock due to inversion) | |
52 | */ | |
1da177e4 | 53 | |
26e32875 CH |
54 | static int __xfs_buf_submit(struct xfs_buf *bp, bool wait); |
55 | ||
56 | static inline int | |
57 | xfs_buf_submit( | |
58 | struct xfs_buf *bp) | |
59 | { | |
60 | return __xfs_buf_submit(bp, !(bp->b_flags & XBF_ASYNC)); | |
61 | } | |
62 | ||
73c77e2c JB |
63 | static inline int |
64 | xfs_buf_is_vmapped( | |
65 | struct xfs_buf *bp) | |
66 | { | |
67 | /* | |
68 | * Return true if the buffer is vmapped. | |
69 | * | |
611c9946 DC |
70 | * b_addr is null if the buffer is not mapped, but the code is clever |
71 | * enough to know it doesn't have to map a single page, so the check has | |
72 | * to be both for b_addr and bp->b_page_count > 1. | |
73c77e2c | 73 | */ |
611c9946 | 74 | return bp->b_addr && bp->b_page_count > 1; |
73c77e2c JB |
75 | } |
76 | ||
77 | static inline int | |
78 | xfs_buf_vmap_len( | |
79 | struct xfs_buf *bp) | |
80 | { | |
54cd3aa6 | 81 | return (bp->b_page_count * PAGE_SIZE); |
73c77e2c JB |
82 | } |
83 | ||
9c7504aa BF |
84 | /* |
85 | * Bump the I/O in flight count on the buftarg if we haven't yet done so for | |
86 | * this buffer. The count is incremented once per buffer (per hold cycle) | |
87 | * because the corresponding decrement is deferred to buffer release. Buffers | |
88 | * can undergo I/O multiple times in a hold-release cycle and per buffer I/O | |
89 | * tracking adds unnecessary overhead. This is used for sychronization purposes | |
10fb9ac1 | 90 | * with unmount (see xfs_buftarg_drain()), so all we really need is a count of |
9c7504aa BF |
91 | * in-flight buffers. |
92 | * | |
93 | * Buffers that are never released (e.g., superblock, iclog buffers) must set | |
94 | * the XBF_NO_IOACCT flag before I/O submission. Otherwise, the buftarg count | |
95 | * never reaches zero and unmount hangs indefinitely. | |
96 | */ | |
97 | static inline void | |
98 | xfs_buf_ioacct_inc( | |
99 | struct xfs_buf *bp) | |
100 | { | |
63db7c81 | 101 | if (bp->b_flags & XBF_NO_IOACCT) |
9c7504aa BF |
102 | return; |
103 | ||
104 | ASSERT(bp->b_flags & XBF_ASYNC); | |
63db7c81 BF |
105 | spin_lock(&bp->b_lock); |
106 | if (!(bp->b_state & XFS_BSTATE_IN_FLIGHT)) { | |
107 | bp->b_state |= XFS_BSTATE_IN_FLIGHT; | |
108 | percpu_counter_inc(&bp->b_target->bt_io_count); | |
109 | } | |
110 | spin_unlock(&bp->b_lock); | |
9c7504aa BF |
111 | } |
112 | ||
113 | /* | |
114 | * Clear the in-flight state on a buffer about to be released to the LRU or | |
115 | * freed and unaccount from the buftarg. | |
116 | */ | |
117 | static inline void | |
63db7c81 | 118 | __xfs_buf_ioacct_dec( |
9c7504aa BF |
119 | struct xfs_buf *bp) |
120 | { | |
95989c46 | 121 | lockdep_assert_held(&bp->b_lock); |
9c7504aa | 122 | |
63db7c81 BF |
123 | if (bp->b_state & XFS_BSTATE_IN_FLIGHT) { |
124 | bp->b_state &= ~XFS_BSTATE_IN_FLIGHT; | |
125 | percpu_counter_dec(&bp->b_target->bt_io_count); | |
126 | } | |
127 | } | |
128 | ||
129 | static inline void | |
130 | xfs_buf_ioacct_dec( | |
131 | struct xfs_buf *bp) | |
132 | { | |
133 | spin_lock(&bp->b_lock); | |
134 | __xfs_buf_ioacct_dec(bp); | |
135 | spin_unlock(&bp->b_lock); | |
9c7504aa BF |
136 | } |
137 | ||
430cbeb8 DC |
138 | /* |
139 | * When we mark a buffer stale, we remove the buffer from the LRU and clear the | |
140 | * b_lru_ref count so that the buffer is freed immediately when the buffer | |
141 | * reference count falls to zero. If the buffer is already on the LRU, we need | |
142 | * to remove the reference that LRU holds on the buffer. | |
143 | * | |
144 | * This prevents build-up of stale buffers on the LRU. | |
145 | */ | |
146 | void | |
147 | xfs_buf_stale( | |
148 | struct xfs_buf *bp) | |
149 | { | |
43ff2122 CH |
150 | ASSERT(xfs_buf_islocked(bp)); |
151 | ||
430cbeb8 | 152 | bp->b_flags |= XBF_STALE; |
43ff2122 CH |
153 | |
154 | /* | |
155 | * Clear the delwri status so that a delwri queue walker will not | |
156 | * flush this buffer to disk now that it is stale. The delwri queue has | |
157 | * a reference to the buffer, so this is safe to do. | |
158 | */ | |
159 | bp->b_flags &= ~_XBF_DELWRI_Q; | |
160 | ||
9c7504aa BF |
161 | /* |
162 | * Once the buffer is marked stale and unlocked, a subsequent lookup | |
163 | * could reset b_flags. There is no guarantee that the buffer is | |
164 | * unaccounted (released to LRU) before that occurs. Drop in-flight | |
165 | * status now to preserve accounting consistency. | |
166 | */ | |
a4082357 | 167 | spin_lock(&bp->b_lock); |
63db7c81 BF |
168 | __xfs_buf_ioacct_dec(bp); |
169 | ||
a4082357 DC |
170 | atomic_set(&bp->b_lru_ref, 0); |
171 | if (!(bp->b_state & XFS_BSTATE_DISPOSE) && | |
e80dfa19 DC |
172 | (list_lru_del(&bp->b_target->bt_lru, &bp->b_lru))) |
173 | atomic_dec(&bp->b_hold); | |
174 | ||
430cbeb8 | 175 | ASSERT(atomic_read(&bp->b_hold) >= 1); |
a4082357 | 176 | spin_unlock(&bp->b_lock); |
430cbeb8 | 177 | } |
1da177e4 | 178 | |
3e85c868 DC |
179 | static int |
180 | xfs_buf_get_maps( | |
181 | struct xfs_buf *bp, | |
182 | int map_count) | |
183 | { | |
184 | ASSERT(bp->b_maps == NULL); | |
185 | bp->b_map_count = map_count; | |
186 | ||
187 | if (map_count == 1) { | |
f4b42421 | 188 | bp->b_maps = &bp->__b_map; |
3e85c868 DC |
189 | return 0; |
190 | } | |
191 | ||
192 | bp->b_maps = kmem_zalloc(map_count * sizeof(struct xfs_buf_map), | |
193 | KM_NOFS); | |
194 | if (!bp->b_maps) | |
2451337d | 195 | return -ENOMEM; |
3e85c868 DC |
196 | return 0; |
197 | } | |
198 | ||
199 | /* | |
200 | * Frees b_pages if it was allocated. | |
201 | */ | |
202 | static void | |
203 | xfs_buf_free_maps( | |
204 | struct xfs_buf *bp) | |
205 | { | |
f4b42421 | 206 | if (bp->b_maps != &bp->__b_map) { |
3e85c868 DC |
207 | kmem_free(bp->b_maps); |
208 | bp->b_maps = NULL; | |
209 | } | |
210 | } | |
211 | ||
32dff5e5 | 212 | static int |
3e85c868 | 213 | _xfs_buf_alloc( |
4347b9d7 | 214 | struct xfs_buftarg *target, |
3e85c868 DC |
215 | struct xfs_buf_map *map, |
216 | int nmaps, | |
32dff5e5 DW |
217 | xfs_buf_flags_t flags, |
218 | struct xfs_buf **bpp) | |
1da177e4 | 219 | { |
4347b9d7 | 220 | struct xfs_buf *bp; |
3e85c868 DC |
221 | int error; |
222 | int i; | |
4347b9d7 | 223 | |
32dff5e5 | 224 | *bpp = NULL; |
182696fb | 225 | bp = kmem_cache_zalloc(xfs_buf_cache, GFP_NOFS | __GFP_NOFAIL); |
4347b9d7 | 226 | |
1da177e4 | 227 | /* |
12bcb3f7 DC |
228 | * We don't want certain flags to appear in b_flags unless they are |
229 | * specifically set by later operations on the buffer. | |
1da177e4 | 230 | */ |
611c9946 | 231 | flags &= ~(XBF_UNMAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD); |
ce8e922c | 232 | |
ce8e922c | 233 | atomic_set(&bp->b_hold, 1); |
430cbeb8 | 234 | atomic_set(&bp->b_lru_ref, 1); |
b4dd330b | 235 | init_completion(&bp->b_iowait); |
430cbeb8 | 236 | INIT_LIST_HEAD(&bp->b_lru); |
ce8e922c | 237 | INIT_LIST_HEAD(&bp->b_list); |
643c8c05 | 238 | INIT_LIST_HEAD(&bp->b_li_list); |
a731cd11 | 239 | sema_init(&bp->b_sema, 0); /* held, no waiters */ |
a4082357 | 240 | spin_lock_init(&bp->b_lock); |
ce8e922c | 241 | bp->b_target = target; |
dbd329f1 | 242 | bp->b_mount = target->bt_mount; |
3e85c868 | 243 | bp->b_flags = flags; |
de1cbee4 | 244 | |
1da177e4 | 245 | /* |
aa0e8833 DC |
246 | * Set length and io_length to the same value initially. |
247 | * I/O routines should use io_length, which will be the same in | |
1da177e4 LT |
248 | * most cases but may be reset (e.g. XFS recovery). |
249 | */ | |
3e85c868 DC |
250 | error = xfs_buf_get_maps(bp, nmaps); |
251 | if (error) { | |
182696fb | 252 | kmem_cache_free(xfs_buf_cache, bp); |
32dff5e5 | 253 | return error; |
3e85c868 DC |
254 | } |
255 | ||
4c7f65ae | 256 | bp->b_rhash_key = map[0].bm_bn; |
3e85c868 DC |
257 | bp->b_length = 0; |
258 | for (i = 0; i < nmaps; i++) { | |
259 | bp->b_maps[i].bm_bn = map[i].bm_bn; | |
260 | bp->b_maps[i].bm_len = map[i].bm_len; | |
261 | bp->b_length += map[i].bm_len; | |
262 | } | |
3e85c868 | 263 | |
ce8e922c NS |
264 | atomic_set(&bp->b_pin_count, 0); |
265 | init_waitqueue_head(&bp->b_waiters); | |
266 | ||
dbd329f1 | 267 | XFS_STATS_INC(bp->b_mount, xb_create); |
0b1b213f | 268 | trace_xfs_buf_init(bp, _RET_IP_); |
4347b9d7 | 269 | |
32dff5e5 DW |
270 | *bpp = bp; |
271 | return 0; | |
1da177e4 LT |
272 | } |
273 | ||
e7d236a6 DC |
274 | static void |
275 | xfs_buf_free_pages( | |
e8222613 | 276 | struct xfs_buf *bp) |
1da177e4 | 277 | { |
e7d236a6 DC |
278 | uint i; |
279 | ||
280 | ASSERT(bp->b_flags & _XBF_PAGES); | |
281 | ||
282 | if (xfs_buf_is_vmapped(bp)) | |
54cd3aa6 | 283 | vm_unmap_ram(bp->b_addr, bp->b_page_count); |
e7d236a6 DC |
284 | |
285 | for (i = 0; i < bp->b_page_count; i++) { | |
286 | if (bp->b_pages[i]) | |
287 | __free_page(bp->b_pages[i]); | |
288 | } | |
c7b23b68 | 289 | mm_account_reclaimed_pages(bp->b_page_count); |
e7d236a6 | 290 | |
02c51173 | 291 | if (bp->b_pages != bp->b_page_array) |
f0e2d93c | 292 | kmem_free(bp->b_pages); |
02c51173 | 293 | bp->b_pages = NULL; |
e7d236a6 | 294 | bp->b_flags &= ~_XBF_PAGES; |
1da177e4 LT |
295 | } |
296 | ||
298f3422 DC |
297 | static void |
298 | xfs_buf_free_callback( | |
299 | struct callback_head *cb) | |
300 | { | |
301 | struct xfs_buf *bp = container_of(cb, struct xfs_buf, b_rcu); | |
302 | ||
303 | xfs_buf_free_maps(bp); | |
304 | kmem_cache_free(xfs_buf_cache, bp); | |
305 | } | |
306 | ||
25a40957 | 307 | static void |
ce8e922c | 308 | xfs_buf_free( |
e8222613 | 309 | struct xfs_buf *bp) |
1da177e4 | 310 | { |
0b1b213f | 311 | trace_xfs_buf_free(bp, _RET_IP_); |
1da177e4 | 312 | |
430cbeb8 DC |
313 | ASSERT(list_empty(&bp->b_lru)); |
314 | ||
e7d236a6 DC |
315 | if (bp->b_flags & _XBF_PAGES) |
316 | xfs_buf_free_pages(bp); | |
317 | else if (bp->b_flags & _XBF_KMEM) | |
0e6e847f | 318 | kmem_free(bp->b_addr); |
e7d236a6 | 319 | |
298f3422 | 320 | call_rcu(&bp->b_rcu, xfs_buf_free_callback); |
1da177e4 LT |
321 | } |
322 | ||
0a683794 DC |
323 | static int |
324 | xfs_buf_alloc_kmem( | |
325 | struct xfs_buf *bp, | |
0a683794 | 326 | xfs_buf_flags_t flags) |
1da177e4 | 327 | { |
0a683794 | 328 | xfs_km_flags_t kmflag_mask = KM_NOFS; |
8bcac744 | 329 | size_t size = BBTOB(bp->b_length); |
3219e8cf | 330 | |
0a683794 DC |
331 | /* Assure zeroed buffer for non-read cases. */ |
332 | if (!(flags & XBF_READ)) | |
3219e8cf | 333 | kmflag_mask |= KM_ZERO; |
1da177e4 | 334 | |
98fe2c3c | 335 | bp->b_addr = kmem_alloc(size, kmflag_mask); |
0a683794 DC |
336 | if (!bp->b_addr) |
337 | return -ENOMEM; | |
0e6e847f | 338 | |
0a683794 DC |
339 | if (((unsigned long)(bp->b_addr + size - 1) & PAGE_MASK) != |
340 | ((unsigned long)bp->b_addr & PAGE_MASK)) { | |
341 | /* b_addr spans two pages - use alloc_page instead */ | |
342 | kmem_free(bp->b_addr); | |
343 | bp->b_addr = NULL; | |
344 | return -ENOMEM; | |
0e6e847f | 345 | } |
0a683794 DC |
346 | bp->b_offset = offset_in_page(bp->b_addr); |
347 | bp->b_pages = bp->b_page_array; | |
348 | bp->b_pages[0] = kmem_to_page(bp->b_addr); | |
349 | bp->b_page_count = 1; | |
350 | bp->b_flags |= _XBF_KMEM; | |
351 | return 0; | |
352 | } | |
353 | ||
354 | static int | |
355 | xfs_buf_alloc_pages( | |
356 | struct xfs_buf *bp, | |
0a683794 DC |
357 | xfs_buf_flags_t flags) |
358 | { | |
289ae7b4 | 359 | gfp_t gfp_mask = __GFP_NOWARN; |
c9fa5630 | 360 | long filled = 0; |
0a683794 | 361 | |
289ae7b4 DC |
362 | if (flags & XBF_READ_AHEAD) |
363 | gfp_mask |= __GFP_NORETRY; | |
364 | else | |
365 | gfp_mask |= GFP_NOFS; | |
366 | ||
02c51173 | 367 | /* Make sure that we have a page list */ |
934d1076 | 368 | bp->b_page_count = DIV_ROUND_UP(BBTOB(bp->b_length), PAGE_SIZE); |
02c51173 DC |
369 | if (bp->b_page_count <= XB_PAGES) { |
370 | bp->b_pages = bp->b_page_array; | |
371 | } else { | |
372 | bp->b_pages = kzalloc(sizeof(struct page *) * bp->b_page_count, | |
373 | gfp_mask); | |
374 | if (!bp->b_pages) | |
375 | return -ENOMEM; | |
376 | } | |
377 | bp->b_flags |= _XBF_PAGES; | |
378 | ||
0a683794 DC |
379 | /* Assure zeroed buffer for non-read cases. */ |
380 | if (!(flags & XBF_READ)) | |
381 | gfp_mask |= __GFP_ZERO; | |
0e6e847f | 382 | |
c9fa5630 DC |
383 | /* |
384 | * Bulk filling of pages can take multiple calls. Not filling the entire | |
385 | * array is not an allocation failure, so don't back off if we get at | |
386 | * least one extra page. | |
387 | */ | |
388 | for (;;) { | |
389 | long last = filled; | |
390 | ||
391 | filled = alloc_pages_bulk_array(gfp_mask, bp->b_page_count, | |
392 | bp->b_pages); | |
393 | if (filled == bp->b_page_count) { | |
394 | XFS_STATS_INC(bp->b_mount, xb_page_found); | |
395 | break; | |
1da177e4 LT |
396 | } |
397 | ||
c9fa5630 DC |
398 | if (filled != last) |
399 | continue; | |
400 | ||
401 | if (flags & XBF_READ_AHEAD) { | |
e7d236a6 DC |
402 | xfs_buf_free_pages(bp); |
403 | return -ENOMEM; | |
c9fa5630 | 404 | } |
1da177e4 | 405 | |
c9fa5630 | 406 | XFS_STATS_INC(bp->b_mount, xb_page_retries); |
4034247a | 407 | memalloc_retry_wait(gfp_mask); |
1da177e4 | 408 | } |
0e6e847f | 409 | return 0; |
1da177e4 LT |
410 | } |
411 | ||
412 | /* | |
25985edc | 413 | * Map buffer into kernel address-space if necessary. |
1da177e4 LT |
414 | */ |
415 | STATIC int | |
ce8e922c | 416 | _xfs_buf_map_pages( |
e8222613 | 417 | struct xfs_buf *bp, |
b9b3fe15 | 418 | xfs_buf_flags_t flags) |
1da177e4 | 419 | { |
0e6e847f | 420 | ASSERT(bp->b_flags & _XBF_PAGES); |
ce8e922c | 421 | if (bp->b_page_count == 1) { |
0e6e847f | 422 | /* A single page buffer is always mappable */ |
54cd3aa6 | 423 | bp->b_addr = page_address(bp->b_pages[0]); |
611c9946 DC |
424 | } else if (flags & XBF_UNMAPPED) { |
425 | bp->b_addr = NULL; | |
426 | } else { | |
a19fb380 | 427 | int retried = 0; |
9ba1fb2c | 428 | unsigned nofs_flag; |
ae687e58 DC |
429 | |
430 | /* | |
cf085a1b | 431 | * vm_map_ram() will allocate auxiliary structures (e.g. |
ae687e58 DC |
432 | * pagetables) with GFP_KERNEL, yet we are likely to be under |
433 | * GFP_NOFS context here. Hence we need to tell memory reclaim | |
9ba1fb2c | 434 | * that we are in such a context via PF_MEMALLOC_NOFS to prevent |
ae687e58 DC |
435 | * memory reclaim re-entering the filesystem here and |
436 | * potentially deadlocking. | |
437 | */ | |
9ba1fb2c | 438 | nofs_flag = memalloc_nofs_save(); |
a19fb380 DC |
439 | do { |
440 | bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, | |
d4efd79a | 441 | -1); |
a19fb380 DC |
442 | if (bp->b_addr) |
443 | break; | |
444 | vm_unmap_aliases(); | |
445 | } while (retried++ <= 1); | |
9ba1fb2c | 446 | memalloc_nofs_restore(nofs_flag); |
a19fb380 DC |
447 | |
448 | if (!bp->b_addr) | |
1da177e4 | 449 | return -ENOMEM; |
1da177e4 LT |
450 | } |
451 | ||
452 | return 0; | |
453 | } | |
454 | ||
455 | /* | |
456 | * Finding and Reading Buffers | |
457 | */ | |
6031e73a LS |
458 | static int |
459 | _xfs_buf_obj_cmp( | |
460 | struct rhashtable_compare_arg *arg, | |
461 | const void *obj) | |
462 | { | |
463 | const struct xfs_buf_map *map = arg->key; | |
464 | const struct xfs_buf *bp = obj; | |
465 | ||
466 | /* | |
467 | * The key hashing in the lookup path depends on the key being the | |
468 | * first element of the compare_arg, make sure to assert this. | |
469 | */ | |
470 | BUILD_BUG_ON(offsetof(struct xfs_buf_map, bm_bn) != 0); | |
471 | ||
4c7f65ae | 472 | if (bp->b_rhash_key != map->bm_bn) |
6031e73a LS |
473 | return 1; |
474 | ||
475 | if (unlikely(bp->b_length != map->bm_len)) { | |
476 | /* | |
477 | * found a block number match. If the range doesn't | |
478 | * match, the only way this is allowed is if the buffer | |
479 | * in the cache is stale and the transaction that made | |
480 | * it stale has not yet committed. i.e. we are | |
481 | * reallocating a busy extent. Skip this buffer and | |
482 | * continue searching for an exact match. | |
483 | */ | |
484 | ASSERT(bp->b_flags & XBF_STALE); | |
485 | return 1; | |
486 | } | |
487 | return 0; | |
488 | } | |
489 | ||
490 | static const struct rhashtable_params xfs_buf_hash_params = { | |
491 | .min_size = 32, /* empty AGs have minimal footprint */ | |
492 | .nelem_hint = 16, | |
493 | .key_len = sizeof(xfs_daddr_t), | |
4c7f65ae | 494 | .key_offset = offsetof(struct xfs_buf, b_rhash_key), |
6031e73a LS |
495 | .head_offset = offsetof(struct xfs_buf, b_rhash_head), |
496 | .automatic_shrinking = true, | |
497 | .obj_cmpfn = _xfs_buf_obj_cmp, | |
498 | }; | |
499 | ||
500 | int | |
501 | xfs_buf_hash_init( | |
502 | struct xfs_perag *pag) | |
503 | { | |
504 | spin_lock_init(&pag->pag_buf_lock); | |
505 | return rhashtable_init(&pag->pag_buf_hash, &xfs_buf_hash_params); | |
506 | } | |
507 | ||
508 | void | |
509 | xfs_buf_hash_destroy( | |
510 | struct xfs_perag *pag) | |
511 | { | |
512 | rhashtable_destroy(&pag->pag_buf_hash); | |
513 | } | |
1da177e4 | 514 | |
b027d4c9 | 515 | static int |
de67dc57 | 516 | xfs_buf_map_verify( |
e70b73f8 | 517 | struct xfs_buftarg *btp, |
de67dc57 | 518 | struct xfs_buf_map *map) |
1da177e4 | 519 | { |
10616b80 | 520 | xfs_daddr_t eofs; |
1da177e4 LT |
521 | |
522 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
de67dc57 DC |
523 | ASSERT(!(BBTOB(map->bm_len) < btp->bt_meta_sectorsize)); |
524 | ASSERT(!(BBTOB(map->bm_bn) & (xfs_off_t)btp->bt_meta_sectormask)); | |
1da177e4 | 525 | |
10616b80 DC |
526 | /* |
527 | * Corrupted block numbers can get through to here, unfortunately, so we | |
528 | * have to check that the buffer falls within the filesystem bounds. | |
529 | */ | |
530 | eofs = XFS_FSB_TO_BB(btp->bt_mount, btp->bt_mount->m_sb.sb_dblocks); | |
de67dc57 | 531 | if (map->bm_bn < 0 || map->bm_bn >= eofs) { |
10616b80 | 532 | xfs_alert(btp->bt_mount, |
c219b015 | 533 | "%s: daddr 0x%llx out of range, EOFS 0x%llx", |
de67dc57 | 534 | __func__, map->bm_bn, eofs); |
7bc0dc27 | 535 | WARN_ON(1); |
b027d4c9 | 536 | return -EFSCORRUPTED; |
10616b80 | 537 | } |
b027d4c9 | 538 | return 0; |
de67dc57 | 539 | } |
1da177e4 | 540 | |
de67dc57 DC |
541 | static int |
542 | xfs_buf_find_lock( | |
543 | struct xfs_buf *bp, | |
544 | xfs_buf_flags_t flags) | |
545 | { | |
d8d9bbb0 DC |
546 | if (flags & XBF_TRYLOCK) { |
547 | if (!xfs_buf_trylock(bp)) { | |
de67dc57 | 548 | XFS_STATS_INC(bp->b_mount, xb_busy_locked); |
b027d4c9 | 549 | return -EAGAIN; |
1da177e4 | 550 | } |
d8d9bbb0 | 551 | } else { |
0c842ad4 | 552 | xfs_buf_lock(bp); |
de67dc57 | 553 | XFS_STATS_INC(bp->b_mount, xb_get_locked_waited); |
1da177e4 LT |
554 | } |
555 | ||
0e6e847f DC |
556 | /* |
557 | * if the buffer is stale, clear all the external state associated with | |
558 | * it. We need to keep flags such as how we allocated the buffer memory | |
559 | * intact here. | |
560 | */ | |
ce8e922c NS |
561 | if (bp->b_flags & XBF_STALE) { |
562 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
611c9946 | 563 | bp->b_flags &= _XBF_KMEM | _XBF_PAGES; |
1813dd64 | 564 | bp->b_ops = NULL; |
2f926587 | 565 | } |
b027d4c9 | 566 | return 0; |
1da177e4 LT |
567 | } |
568 | ||
34800080 | 569 | static inline int |
de67dc57 DC |
570 | xfs_buf_lookup( |
571 | struct xfs_perag *pag, | |
34800080 DC |
572 | struct xfs_buf_map *map, |
573 | xfs_buf_flags_t flags, | |
574 | struct xfs_buf **bpp) | |
8925a3dc | 575 | { |
de67dc57 | 576 | struct xfs_buf *bp; |
b027d4c9 | 577 | int error; |
b027d4c9 | 578 | |
298f3422 | 579 | rcu_read_lock(); |
de67dc57 | 580 | bp = rhashtable_lookup(&pag->pag_buf_hash, map, xfs_buf_hash_params); |
298f3422 DC |
581 | if (!bp || !atomic_inc_not_zero(&bp->b_hold)) { |
582 | rcu_read_unlock(); | |
34800080 DC |
583 | return -ENOENT; |
584 | } | |
298f3422 | 585 | rcu_read_unlock(); |
de67dc57 | 586 | |
34800080 DC |
587 | error = xfs_buf_find_lock(bp, flags); |
588 | if (error) { | |
589 | xfs_buf_rele(bp); | |
590 | return error; | |
de67dc57 DC |
591 | } |
592 | ||
34800080 DC |
593 | trace_xfs_buf_find(bp, flags, _RET_IP_); |
594 | *bpp = bp; | |
de67dc57 | 595 | return 0; |
8925a3dc DC |
596 | } |
597 | ||
1da177e4 | 598 | /* |
34800080 DC |
599 | * Insert the new_bp into the hash table. This consumes the perag reference |
600 | * taken for the lookup regardless of the result of the insert. | |
1da177e4 | 601 | */ |
b027d4c9 | 602 | static int |
34800080 | 603 | xfs_buf_find_insert( |
e70b73f8 | 604 | struct xfs_buftarg *btp, |
34800080 DC |
605 | struct xfs_perag *pag, |
606 | struct xfs_buf_map *cmap, | |
6dde2707 DC |
607 | struct xfs_buf_map *map, |
608 | int nmaps, | |
3848b5f6 DW |
609 | xfs_buf_flags_t flags, |
610 | struct xfs_buf **bpp) | |
1da177e4 | 611 | { |
3815832a | 612 | struct xfs_buf *new_bp; |
e8222613 | 613 | struct xfs_buf *bp; |
9bb38aa0 | 614 | int error; |
1da177e4 | 615 | |
34800080 | 616 | error = _xfs_buf_alloc(btp, map, nmaps, flags, &new_bp); |
32dff5e5 | 617 | if (error) |
34800080 | 618 | goto out_drop_pag; |
1da177e4 | 619 | |
8bcac744 DC |
620 | /* |
621 | * For buffers that fit entirely within a single page, first attempt to | |
622 | * allocate the memory from the heap to minimise memory usage. If we | |
623 | * can't get heap memory for these small buffers, we fall back to using | |
624 | * the page allocator. | |
625 | */ | |
626 | if (BBTOB(new_bp->b_length) >= PAGE_SIZE || | |
627 | xfs_buf_alloc_kmem(new_bp, flags) < 0) { | |
628 | error = xfs_buf_alloc_pages(new_bp, flags); | |
629 | if (error) | |
630 | goto out_free_buf; | |
631 | } | |
fe2429b0 | 632 | |
74f75a0c | 633 | spin_lock(&pag->pag_buf_lock); |
32dd4f9c DC |
634 | bp = rhashtable_lookup_get_insert_fast(&pag->pag_buf_hash, |
635 | &new_bp->b_rhash_head, xfs_buf_hash_params); | |
636 | if (IS_ERR(bp)) { | |
637 | error = PTR_ERR(bp); | |
638 | spin_unlock(&pag->pag_buf_lock); | |
170041f7 | 639 | goto out_free_buf; |
32dd4f9c | 640 | } |
34800080 | 641 | if (bp) { |
32dd4f9c | 642 | /* found an existing buffer */ |
34800080 DC |
643 | atomic_inc(&bp->b_hold); |
644 | spin_unlock(&pag->pag_buf_lock); | |
645 | error = xfs_buf_find_lock(bp, flags); | |
646 | if (error) | |
647 | xfs_buf_rele(bp); | |
648 | else | |
649 | *bpp = bp; | |
650 | goto out_free_buf; | |
651 | } | |
1da177e4 | 652 | |
32dd4f9c | 653 | /* The new buffer keeps the perag reference until it is freed. */ |
34800080 | 654 | new_bp->b_pag = pag; |
b027d4c9 | 655 | spin_unlock(&pag->pag_buf_lock); |
34800080 | 656 | *bpp = new_bp; |
b027d4c9 | 657 | return 0; |
3815832a | 658 | |
34800080 DC |
659 | out_free_buf: |
660 | xfs_buf_free(new_bp); | |
661 | out_drop_pag: | |
74f75a0c | 662 | xfs_perag_put(pag); |
34800080 | 663 | return error; |
1da177e4 | 664 | } |
1da177e4 | 665 | |
1da177e4 | 666 | /* |
3815832a DC |
667 | * Assembles a buffer covering the specified range. The code is optimised for |
668 | * cache hits, as metadata intensive workloads will see 3 orders of magnitude | |
669 | * more hits than misses. | |
1da177e4 | 670 | */ |
3848b5f6 | 671 | int |
6dde2707 | 672 | xfs_buf_get_map( |
34800080 | 673 | struct xfs_buftarg *btp, |
6dde2707 DC |
674 | struct xfs_buf_map *map, |
675 | int nmaps, | |
3848b5f6 DW |
676 | xfs_buf_flags_t flags, |
677 | struct xfs_buf **bpp) | |
1da177e4 | 678 | { |
34800080 DC |
679 | struct xfs_perag *pag; |
680 | struct xfs_buf *bp = NULL; | |
681 | struct xfs_buf_map cmap = { .bm_bn = map[0].bm_bn }; | |
9bb38aa0 | 682 | int error; |
34800080 | 683 | int i; |
1da177e4 | 684 | |
34800080 DC |
685 | for (i = 0; i < nmaps; i++) |
686 | cmap.bm_len += map[i].bm_len; | |
3815832a | 687 | |
34800080 | 688 | error = xfs_buf_map_verify(btp, &cmap); |
32dff5e5 | 689 | if (error) |
3848b5f6 | 690 | return error; |
1da177e4 | 691 | |
34800080 DC |
692 | pag = xfs_perag_get(btp->bt_mount, |
693 | xfs_daddr_to_agno(btp->bt_mount, cmap.bm_bn)); | |
fe2429b0 | 694 | |
34800080 DC |
695 | error = xfs_buf_lookup(pag, &cmap, flags, &bp); |
696 | if (error && error != -ENOENT) | |
697 | goto out_put_perag; | |
698 | ||
699 | /* cache hits always outnumber misses by at least 10:1 */ | |
700 | if (unlikely(!bp)) { | |
701 | XFS_STATS_INC(btp->bt_mount, xb_miss_locked); | |
3815832a | 702 | |
34800080 DC |
703 | if (flags & XBF_INCORE) |
704 | goto out_put_perag; | |
1da177e4 | 705 | |
34800080 DC |
706 | /* xfs_buf_find_insert() consumes the perag reference. */ |
707 | error = xfs_buf_find_insert(btp, pag, &cmap, map, nmaps, | |
708 | flags, &bp); | |
709 | if (error) | |
710 | return error; | |
711 | } else { | |
712 | XFS_STATS_INC(btp->bt_mount, xb_get_locked); | |
713 | xfs_perag_put(pag); | |
714 | } | |
715 | ||
716 | /* We do not hold a perag reference anymore. */ | |
611c9946 | 717 | if (!bp->b_addr) { |
ce8e922c | 718 | error = _xfs_buf_map_pages(bp, flags); |
1da177e4 | 719 | if (unlikely(error)) { |
34800080 | 720 | xfs_warn_ratelimited(btp->bt_mount, |
93baa55a DW |
721 | "%s: failed to map %u pages", __func__, |
722 | bp->b_page_count); | |
a8acad70 | 723 | xfs_buf_relse(bp); |
3848b5f6 | 724 | return error; |
1da177e4 LT |
725 | } |
726 | } | |
727 | ||
b79f4a1c DC |
728 | /* |
729 | * Clear b_error if this is a lookup from a caller that doesn't expect | |
730 | * valid data to be found in the buffer. | |
731 | */ | |
732 | if (!(flags & XBF_READ)) | |
733 | xfs_buf_ioerror(bp, 0); | |
734 | ||
34800080 | 735 | XFS_STATS_INC(btp->bt_mount, xb_get); |
0b1b213f | 736 | trace_xfs_buf_get(bp, flags, _RET_IP_); |
3848b5f6 DW |
737 | *bpp = bp; |
738 | return 0; | |
34800080 DC |
739 | |
740 | out_put_perag: | |
741 | xfs_perag_put(pag); | |
170041f7 | 742 | return error; |
1da177e4 LT |
743 | } |
744 | ||
26e32875 | 745 | int |
5d765b97 | 746 | _xfs_buf_read( |
e8222613 | 747 | struct xfs_buf *bp, |
5d765b97 CH |
748 | xfs_buf_flags_t flags) |
749 | { | |
43ff2122 | 750 | ASSERT(!(flags & XBF_WRITE)); |
f4b42421 | 751 | ASSERT(bp->b_maps[0].bm_bn != XFS_BUF_DADDR_NULL); |
5d765b97 | 752 | |
26e32875 | 753 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD | XBF_DONE); |
1d5ae5df | 754 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD); |
5d765b97 | 755 | |
6af88cda | 756 | return xfs_buf_submit(bp); |
5d765b97 CH |
757 | } |
758 | ||
1aff5696 | 759 | /* |
75d02303 | 760 | * Reverify a buffer found in cache without an attached ->b_ops. |
add46b3b | 761 | * |
75d02303 BF |
762 | * If the caller passed an ops structure and the buffer doesn't have ops |
763 | * assigned, set the ops and use it to verify the contents. If verification | |
764 | * fails, clear XBF_DONE. We assume the buffer has no recorded errors and is | |
765 | * already in XBF_DONE state on entry. | |
add46b3b | 766 | * |
75d02303 BF |
767 | * Under normal operations, every in-core buffer is verified on read I/O |
768 | * completion. There are two scenarios that can lead to in-core buffers without | |
769 | * an assigned ->b_ops. The first is during log recovery of buffers on a V4 | |
770 | * filesystem, though these buffers are purged at the end of recovery. The | |
771 | * other is online repair, which intentionally reads with a NULL buffer ops to | |
772 | * run several verifiers across an in-core buffer in order to establish buffer | |
773 | * type. If repair can't establish that, the buffer will be left in memory | |
774 | * with NULL buffer ops. | |
1aff5696 DW |
775 | */ |
776 | int | |
75d02303 | 777 | xfs_buf_reverify( |
1aff5696 DW |
778 | struct xfs_buf *bp, |
779 | const struct xfs_buf_ops *ops) | |
780 | { | |
781 | ASSERT(bp->b_flags & XBF_DONE); | |
782 | ASSERT(bp->b_error == 0); | |
783 | ||
784 | if (!ops || bp->b_ops) | |
785 | return 0; | |
786 | ||
787 | bp->b_ops = ops; | |
788 | bp->b_ops->verify_read(bp); | |
789 | if (bp->b_error) | |
790 | bp->b_flags &= ~XBF_DONE; | |
791 | return bp->b_error; | |
792 | } | |
793 | ||
4ed8e27b | 794 | int |
6dde2707 DC |
795 | xfs_buf_read_map( |
796 | struct xfs_buftarg *target, | |
797 | struct xfs_buf_map *map, | |
798 | int nmaps, | |
c3f8fc73 | 799 | xfs_buf_flags_t flags, |
4ed8e27b | 800 | struct xfs_buf **bpp, |
cdbcf82b DW |
801 | const struct xfs_buf_ops *ops, |
802 | xfs_failaddr_t fa) | |
1da177e4 | 803 | { |
6dde2707 | 804 | struct xfs_buf *bp; |
3848b5f6 | 805 | int error; |
ce8e922c NS |
806 | |
807 | flags |= XBF_READ; | |
4ed8e27b | 808 | *bpp = NULL; |
ce8e922c | 809 | |
3848b5f6 DW |
810 | error = xfs_buf_get_map(target, map, nmaps, flags, &bp); |
811 | if (error) | |
4ed8e27b | 812 | return error; |
0b1b213f | 813 | |
1aff5696 DW |
814 | trace_xfs_buf_read(bp, flags, _RET_IP_); |
815 | ||
816 | if (!(bp->b_flags & XBF_DONE)) { | |
4ed8e27b | 817 | /* Initiate the buffer read and wait. */ |
1aff5696 DW |
818 | XFS_STATS_INC(target->bt_mount, xb_get_read); |
819 | bp->b_ops = ops; | |
4ed8e27b DW |
820 | error = _xfs_buf_read(bp, flags); |
821 | ||
822 | /* Readahead iodone already dropped the buffer, so exit. */ | |
823 | if (flags & XBF_ASYNC) | |
824 | return 0; | |
825 | } else { | |
826 | /* Buffer already read; all we need to do is check it. */ | |
827 | error = xfs_buf_reverify(bp, ops); | |
828 | ||
829 | /* Readahead already finished; drop the buffer and exit. */ | |
830 | if (flags & XBF_ASYNC) { | |
831 | xfs_buf_relse(bp); | |
832 | return 0; | |
833 | } | |
834 | ||
835 | /* We do not want read in the flags */ | |
836 | bp->b_flags &= ~XBF_READ; | |
837 | ASSERT(bp->b_ops != NULL || ops == NULL); | |
1aff5696 DW |
838 | } |
839 | ||
4ed8e27b DW |
840 | /* |
841 | * If we've had a read error, then the contents of the buffer are | |
842 | * invalid and should not be used. To ensure that a followup read tries | |
843 | * to pull the buffer from disk again, we clear the XBF_DONE flag and | |
844 | * mark the buffer stale. This ensures that anyone who has a current | |
845 | * reference to the buffer will interpret it's contents correctly and | |
846 | * future cache lookups will also treat it as an empty, uninitialised | |
847 | * buffer. | |
848 | */ | |
849 | if (error) { | |
01728b44 DC |
850 | /* |
851 | * Check against log shutdown for error reporting because | |
852 | * metadata writeback may require a read first and we need to | |
853 | * report errors in metadata writeback until the log is shut | |
854 | * down. High level transaction read functions already check | |
855 | * against mount shutdown, anyway, so we only need to be | |
856 | * concerned about low level IO interactions here. | |
857 | */ | |
858 | if (!xlog_is_shutdown(target->bt_mount->m_log)) | |
cdbcf82b | 859 | xfs_buf_ioerror_alert(bp, fa); |
1aff5696 | 860 | |
4ed8e27b DW |
861 | bp->b_flags &= ~XBF_DONE; |
862 | xfs_buf_stale(bp); | |
1aff5696 | 863 | xfs_buf_relse(bp); |
4ed8e27b DW |
864 | |
865 | /* bad CRC means corrupted metadata */ | |
866 | if (error == -EFSBADCRC) | |
867 | error = -EFSCORRUPTED; | |
868 | return error; | |
1da177e4 LT |
869 | } |
870 | ||
4ed8e27b DW |
871 | *bpp = bp; |
872 | return 0; | |
1da177e4 LT |
873 | } |
874 | ||
1da177e4 | 875 | /* |
ce8e922c NS |
876 | * If we are not low on memory then do the readahead in a deadlock |
877 | * safe manner. | |
1da177e4 LT |
878 | */ |
879 | void | |
6dde2707 DC |
880 | xfs_buf_readahead_map( |
881 | struct xfs_buftarg *target, | |
882 | struct xfs_buf_map *map, | |
c3f8fc73 | 883 | int nmaps, |
1813dd64 | 884 | const struct xfs_buf_ops *ops) |
1da177e4 | 885 | { |
4ed8e27b DW |
886 | struct xfs_buf *bp; |
887 | ||
6dde2707 | 888 | xfs_buf_read_map(target, map, nmaps, |
cdbcf82b DW |
889 | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD, &bp, ops, |
890 | __this_address); | |
1da177e4 LT |
891 | } |
892 | ||
5adc94c2 DC |
893 | /* |
894 | * Read an uncached buffer from disk. Allocates and returns a locked | |
4c7f65ae DC |
895 | * buffer containing the disk contents or nothing. Uncached buffers always have |
896 | * a cache index of XFS_BUF_DADDR_NULL so we can easily determine if the buffer | |
897 | * is cached or uncached during fault diagnosis. | |
5adc94c2 | 898 | */ |
ba372674 | 899 | int |
5adc94c2 | 900 | xfs_buf_read_uncached( |
5adc94c2 DC |
901 | struct xfs_buftarg *target, |
902 | xfs_daddr_t daddr, | |
e70b73f8 | 903 | size_t numblks, |
b9b3fe15 | 904 | xfs_buf_flags_t flags, |
ba372674 | 905 | struct xfs_buf **bpp, |
1813dd64 | 906 | const struct xfs_buf_ops *ops) |
5adc94c2 | 907 | { |
eab4e633 | 908 | struct xfs_buf *bp; |
2842b6db | 909 | int error; |
5adc94c2 | 910 | |
ba372674 DC |
911 | *bpp = NULL; |
912 | ||
2842b6db DW |
913 | error = xfs_buf_get_uncached(target, numblks, flags, &bp); |
914 | if (error) | |
915 | return error; | |
5adc94c2 DC |
916 | |
917 | /* set up the buffer for a read IO */ | |
3e85c868 | 918 | ASSERT(bp->b_map_count == 1); |
4c7f65ae | 919 | bp->b_rhash_key = XFS_BUF_DADDR_NULL; |
3e85c868 | 920 | bp->b_maps[0].bm_bn = daddr; |
cbb7baab | 921 | bp->b_flags |= XBF_READ; |
1813dd64 | 922 | bp->b_ops = ops; |
5adc94c2 | 923 | |
6af88cda | 924 | xfs_buf_submit(bp); |
ba372674 | 925 | if (bp->b_error) { |
2842b6db | 926 | error = bp->b_error; |
83a0adc3 | 927 | xfs_buf_relse(bp); |
ba372674 | 928 | return error; |
83a0adc3 | 929 | } |
ba372674 DC |
930 | |
931 | *bpp = bp; | |
932 | return 0; | |
1da177e4 LT |
933 | } |
934 | ||
2842b6db | 935 | int |
686865f7 DC |
936 | xfs_buf_get_uncached( |
937 | struct xfs_buftarg *target, | |
e70b73f8 | 938 | size_t numblks, |
b9b3fe15 | 939 | xfs_buf_flags_t flags, |
2842b6db | 940 | struct xfs_buf **bpp) |
1da177e4 | 941 | { |
07b5c5ad | 942 | int error; |
3e85c868 DC |
943 | struct xfs_buf *bp; |
944 | DEFINE_SINGLE_BUF_MAP(map, XFS_BUF_DADDR_NULL, numblks); | |
1da177e4 | 945 | |
2842b6db DW |
946 | *bpp = NULL; |
947 | ||
c891c30a | 948 | /* flags might contain irrelevant bits, pass only what we care about */ |
32dff5e5 DW |
949 | error = _xfs_buf_alloc(target, &map, 1, flags & XBF_NO_IOACCT, &bp); |
950 | if (error) | |
07b5c5ad | 951 | return error; |
1da177e4 | 952 | |
934d1076 | 953 | error = xfs_buf_alloc_pages(bp, flags); |
1fa40b01 | 954 | if (error) |
1da177e4 LT |
955 | goto fail_free_buf; |
956 | ||
611c9946 | 957 | error = _xfs_buf_map_pages(bp, 0); |
1fa40b01 | 958 | if (unlikely(error)) { |
4f10700a | 959 | xfs_warn(target->bt_mount, |
08e96e1a | 960 | "%s: failed to map pages", __func__); |
07b5c5ad | 961 | goto fail_free_buf; |
1fa40b01 | 962 | } |
1da177e4 | 963 | |
686865f7 | 964 | trace_xfs_buf_get_uncached(bp, _RET_IP_); |
2842b6db DW |
965 | *bpp = bp; |
966 | return 0; | |
1fa40b01 | 967 | |
07b5c5ad DC |
968 | fail_free_buf: |
969 | xfs_buf_free(bp); | |
2842b6db | 970 | return error; |
1da177e4 LT |
971 | } |
972 | ||
973 | /* | |
1da177e4 LT |
974 | * Increment reference count on buffer, to hold the buffer concurrently |
975 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
976 | * Must hold the buffer already to call this function. |
977 | */ | |
978 | void | |
ce8e922c | 979 | xfs_buf_hold( |
e8222613 | 980 | struct xfs_buf *bp) |
1da177e4 | 981 | { |
0b1b213f | 982 | trace_xfs_buf_hold(bp, _RET_IP_); |
ce8e922c | 983 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
984 | } |
985 | ||
986 | /* | |
9c7504aa BF |
987 | * Release a hold on the specified buffer. If the hold count is 1, the buffer is |
988 | * placed on LRU or freed (depending on b_lru_ref). | |
1da177e4 LT |
989 | */ |
990 | void | |
ce8e922c | 991 | xfs_buf_rele( |
e8222613 | 992 | struct xfs_buf *bp) |
1da177e4 | 993 | { |
74f75a0c | 994 | struct xfs_perag *pag = bp->b_pag; |
9c7504aa BF |
995 | bool release; |
996 | bool freebuf = false; | |
1da177e4 | 997 | |
0b1b213f | 998 | trace_xfs_buf_rele(bp, _RET_IP_); |
1da177e4 | 999 | |
74f75a0c | 1000 | if (!pag) { |
430cbeb8 | 1001 | ASSERT(list_empty(&bp->b_lru)); |
9c7504aa BF |
1002 | if (atomic_dec_and_test(&bp->b_hold)) { |
1003 | xfs_buf_ioacct_dec(bp); | |
fad3aa1e | 1004 | xfs_buf_free(bp); |
9c7504aa | 1005 | } |
fad3aa1e NS |
1006 | return; |
1007 | } | |
1008 | ||
3790689f | 1009 | ASSERT(atomic_read(&bp->b_hold) > 0); |
a4082357 | 1010 | |
37fd1678 DC |
1011 | /* |
1012 | * We grab the b_lock here first to serialise racing xfs_buf_rele() | |
1013 | * calls. The pag_buf_lock being taken on the last reference only | |
1014 | * serialises against racing lookups in xfs_buf_find(). IOWs, the second | |
1015 | * to last reference we drop here is not serialised against the last | |
1016 | * reference until we take bp->b_lock. Hence if we don't grab b_lock | |
1017 | * first, the last "release" reference can win the race to the lock and | |
1018 | * free the buffer before the second-to-last reference is processed, | |
1019 | * leading to a use-after-free scenario. | |
1020 | */ | |
9c7504aa | 1021 | spin_lock(&bp->b_lock); |
37fd1678 | 1022 | release = atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock); |
9c7504aa BF |
1023 | if (!release) { |
1024 | /* | |
1025 | * Drop the in-flight state if the buffer is already on the LRU | |
1026 | * and it holds the only reference. This is racy because we | |
1027 | * haven't acquired the pag lock, but the use of _XBF_IN_FLIGHT | |
1028 | * ensures the decrement occurs only once per-buf. | |
1029 | */ | |
1030 | if ((atomic_read(&bp->b_hold) == 1) && !list_empty(&bp->b_lru)) | |
63db7c81 | 1031 | __xfs_buf_ioacct_dec(bp); |
9c7504aa BF |
1032 | goto out_unlock; |
1033 | } | |
1034 | ||
1035 | /* the last reference has been dropped ... */ | |
63db7c81 | 1036 | __xfs_buf_ioacct_dec(bp); |
9c7504aa BF |
1037 | if (!(bp->b_flags & XBF_STALE) && atomic_read(&bp->b_lru_ref)) { |
1038 | /* | |
1039 | * If the buffer is added to the LRU take a new reference to the | |
1040 | * buffer for the LRU and clear the (now stale) dispose list | |
1041 | * state flag | |
1042 | */ | |
1043 | if (list_lru_add(&bp->b_target->bt_lru, &bp->b_lru)) { | |
1044 | bp->b_state &= ~XFS_BSTATE_DISPOSE; | |
1045 | atomic_inc(&bp->b_hold); | |
1da177e4 | 1046 | } |
9c7504aa BF |
1047 | spin_unlock(&pag->pag_buf_lock); |
1048 | } else { | |
1049 | /* | |
1050 | * most of the time buffers will already be removed from the | |
1051 | * LRU, so optimise that case by checking for the | |
1052 | * XFS_BSTATE_DISPOSE flag indicating the last list the buffer | |
1053 | * was on was the disposal list | |
1054 | */ | |
1055 | if (!(bp->b_state & XFS_BSTATE_DISPOSE)) { | |
1056 | list_lru_del(&bp->b_target->bt_lru, &bp->b_lru); | |
1057 | } else { | |
1058 | ASSERT(list_empty(&bp->b_lru)); | |
1da177e4 | 1059 | } |
9c7504aa BF |
1060 | |
1061 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); | |
6031e73a LS |
1062 | rhashtable_remove_fast(&pag->pag_buf_hash, &bp->b_rhash_head, |
1063 | xfs_buf_hash_params); | |
9c7504aa BF |
1064 | spin_unlock(&pag->pag_buf_lock); |
1065 | xfs_perag_put(pag); | |
1066 | freebuf = true; | |
1da177e4 | 1067 | } |
9c7504aa BF |
1068 | |
1069 | out_unlock: | |
1070 | spin_unlock(&bp->b_lock); | |
1071 | ||
1072 | if (freebuf) | |
1073 | xfs_buf_free(bp); | |
1da177e4 LT |
1074 | } |
1075 | ||
1076 | ||
1077 | /* | |
0e6e847f | 1078 | * Lock a buffer object, if it is not already locked. |
90810b9e DC |
1079 | * |
1080 | * If we come across a stale, pinned, locked buffer, we know that we are | |
1081 | * being asked to lock a buffer that has been reallocated. Because it is | |
1082 | * pinned, we know that the log has not been pushed to disk and hence it | |
1083 | * will still be locked. Rather than continuing to have trylock attempts | |
1084 | * fail until someone else pushes the log, push it ourselves before | |
1085 | * returning. This means that the xfsaild will not get stuck trying | |
1086 | * to push on stale inode buffers. | |
1da177e4 LT |
1087 | */ |
1088 | int | |
0c842ad4 CH |
1089 | xfs_buf_trylock( |
1090 | struct xfs_buf *bp) | |
1da177e4 LT |
1091 | { |
1092 | int locked; | |
1093 | ||
ce8e922c | 1094 | locked = down_trylock(&bp->b_sema) == 0; |
fa6c668d | 1095 | if (locked) |
479c6412 | 1096 | trace_xfs_buf_trylock(bp, _RET_IP_); |
fa6c668d | 1097 | else |
479c6412 | 1098 | trace_xfs_buf_trylock_fail(bp, _RET_IP_); |
0c842ad4 | 1099 | return locked; |
1da177e4 | 1100 | } |
1da177e4 LT |
1101 | |
1102 | /* | |
0e6e847f | 1103 | * Lock a buffer object. |
ed3b4d6c DC |
1104 | * |
1105 | * If we come across a stale, pinned, locked buffer, we know that we | |
1106 | * are being asked to lock a buffer that has been reallocated. Because | |
1107 | * it is pinned, we know that the log has not been pushed to disk and | |
1108 | * hence it will still be locked. Rather than sleeping until someone | |
1109 | * else pushes the log, push it ourselves before trying to get the lock. | |
1da177e4 | 1110 | */ |
ce8e922c NS |
1111 | void |
1112 | xfs_buf_lock( | |
0c842ad4 | 1113 | struct xfs_buf *bp) |
1da177e4 | 1114 | { |
0b1b213f CH |
1115 | trace_xfs_buf_lock(bp, _RET_IP_); |
1116 | ||
ed3b4d6c | 1117 | if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
dbd329f1 | 1118 | xfs_log_force(bp->b_mount, 0); |
ce8e922c | 1119 | down(&bp->b_sema); |
0b1b213f CH |
1120 | |
1121 | trace_xfs_buf_lock_done(bp, _RET_IP_); | |
1da177e4 LT |
1122 | } |
1123 | ||
1da177e4 | 1124 | void |
ce8e922c | 1125 | xfs_buf_unlock( |
0c842ad4 | 1126 | struct xfs_buf *bp) |
1da177e4 | 1127 | { |
20e8a063 BF |
1128 | ASSERT(xfs_buf_islocked(bp)); |
1129 | ||
ce8e922c | 1130 | up(&bp->b_sema); |
0b1b213f | 1131 | trace_xfs_buf_unlock(bp, _RET_IP_); |
1da177e4 LT |
1132 | } |
1133 | ||
ce8e922c NS |
1134 | STATIC void |
1135 | xfs_buf_wait_unpin( | |
e8222613 | 1136 | struct xfs_buf *bp) |
1da177e4 LT |
1137 | { |
1138 | DECLARE_WAITQUEUE (wait, current); | |
1139 | ||
ce8e922c | 1140 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
1141 | return; |
1142 | ||
ce8e922c | 1143 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1144 | for (;;) { |
1145 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 1146 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 1147 | break; |
7eaceacc | 1148 | io_schedule(); |
1da177e4 | 1149 | } |
ce8e922c | 1150 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1151 | set_current_state(TASK_RUNNING); |
1152 | } | |
1153 | ||
f58d0ea9 CH |
1154 | static void |
1155 | xfs_buf_ioerror_alert_ratelimited( | |
664ffb8a CH |
1156 | struct xfs_buf *bp) |
1157 | { | |
664ffb8a CH |
1158 | static unsigned long lasttime; |
1159 | static struct xfs_buftarg *lasttarg; | |
1160 | ||
664ffb8a CH |
1161 | if (bp->b_target != lasttarg || |
1162 | time_after(jiffies, (lasttime + 5*HZ))) { | |
1163 | lasttime = jiffies; | |
1164 | xfs_buf_ioerror_alert(bp, __this_address); | |
1165 | } | |
1166 | lasttarg = bp->b_target; | |
664ffb8a CH |
1167 | } |
1168 | ||
664ffb8a CH |
1169 | /* |
1170 | * Account for this latest trip around the retry handler, and decide if | |
1171 | * we've failed enough times to constitute a permanent failure. | |
1172 | */ | |
1173 | static bool | |
1174 | xfs_buf_ioerror_permanent( | |
1175 | struct xfs_buf *bp, | |
1176 | struct xfs_error_cfg *cfg) | |
1177 | { | |
1178 | struct xfs_mount *mp = bp->b_mount; | |
1179 | ||
1180 | if (cfg->max_retries != XFS_ERR_RETRY_FOREVER && | |
1181 | ++bp->b_retries > cfg->max_retries) | |
1182 | return true; | |
1183 | if (cfg->retry_timeout != XFS_ERR_RETRY_FOREVER && | |
1184 | time_after(jiffies, cfg->retry_timeout + bp->b_first_retry_time)) | |
1185 | return true; | |
1186 | ||
1187 | /* At unmount we may treat errors differently */ | |
2e973b2c | 1188 | if (xfs_is_unmounting(mp) && mp->m_fail_unmount) |
664ffb8a CH |
1189 | return true; |
1190 | ||
1191 | return false; | |
1192 | } | |
1193 | ||
1194 | /* | |
1195 | * On a sync write or shutdown we just want to stale the buffer and let the | |
1196 | * caller handle the error in bp->b_error appropriately. | |
1197 | * | |
1198 | * If the write was asynchronous then no one will be looking for the error. If | |
1199 | * this is the first failure of this type, clear the error state and write the | |
1200 | * buffer out again. This means we always retry an async write failure at least | |
1201 | * once, but we also need to set the buffer up to behave correctly now for | |
1202 | * repeated failures. | |
1203 | * | |
1204 | * If we get repeated async write failures, then we take action according to the | |
1205 | * error configuration we have been set up to use. | |
1206 | * | |
70796c6b CH |
1207 | * Returns true if this function took care of error handling and the caller must |
1208 | * not touch the buffer again. Return false if the caller should proceed with | |
1209 | * normal I/O completion handling. | |
664ffb8a | 1210 | */ |
70796c6b CH |
1211 | static bool |
1212 | xfs_buf_ioend_handle_error( | |
664ffb8a CH |
1213 | struct xfs_buf *bp) |
1214 | { | |
1215 | struct xfs_mount *mp = bp->b_mount; | |
1216 | struct xfs_error_cfg *cfg; | |
1217 | ||
f58d0ea9 | 1218 | /* |
01728b44 DC |
1219 | * If we've already shutdown the journal because of I/O errors, there's |
1220 | * no point in giving this a retry. | |
f58d0ea9 | 1221 | */ |
01728b44 | 1222 | if (xlog_is_shutdown(mp->m_log)) |
f58d0ea9 CH |
1223 | goto out_stale; |
1224 | ||
1225 | xfs_buf_ioerror_alert_ratelimited(bp); | |
1226 | ||
22c10589 CH |
1227 | /* |
1228 | * We're not going to bother about retrying this during recovery. | |
1229 | * One strike! | |
1230 | */ | |
1231 | if (bp->b_flags & _XBF_LOGRECOVERY) { | |
1232 | xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR); | |
1233 | return false; | |
1234 | } | |
1235 | ||
f58d0ea9 CH |
1236 | /* |
1237 | * Synchronous writes will have callers process the error. | |
1238 | */ | |
1239 | if (!(bp->b_flags & XBF_ASYNC)) | |
664ffb8a CH |
1240 | goto out_stale; |
1241 | ||
1242 | trace_xfs_buf_iodone_async(bp, _RET_IP_); | |
1243 | ||
1244 | cfg = xfs_error_get_cfg(mp, XFS_ERR_METADATA, bp->b_error); | |
3cc49884 CH |
1245 | if (bp->b_last_error != bp->b_error || |
1246 | !(bp->b_flags & (XBF_STALE | XBF_WRITE_FAIL))) { | |
1247 | bp->b_last_error = bp->b_error; | |
1248 | if (cfg->retry_timeout != XFS_ERR_RETRY_FOREVER && | |
1249 | !bp->b_first_retry_time) | |
1250 | bp->b_first_retry_time = jiffies; | |
1251 | goto resubmit; | |
664ffb8a CH |
1252 | } |
1253 | ||
1254 | /* | |
1255 | * Permanent error - we need to trigger a shutdown if we haven't already | |
1256 | * to indicate that inconsistency will result from this action. | |
1257 | */ | |
1258 | if (xfs_buf_ioerror_permanent(bp, cfg)) { | |
1259 | xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR); | |
1260 | goto out_stale; | |
1261 | } | |
1262 | ||
1263 | /* Still considered a transient error. Caller will schedule retries. */ | |
844c9358 CH |
1264 | if (bp->b_flags & _XBF_INODES) |
1265 | xfs_buf_inode_io_fail(bp); | |
1266 | else if (bp->b_flags & _XBF_DQUOTS) | |
1267 | xfs_buf_dquot_io_fail(bp); | |
1268 | else | |
1269 | ASSERT(list_empty(&bp->b_li_list)); | |
1270 | xfs_buf_ioerror(bp, 0); | |
1271 | xfs_buf_relse(bp); | |
70796c6b | 1272 | return true; |
664ffb8a | 1273 | |
3cc49884 CH |
1274 | resubmit: |
1275 | xfs_buf_ioerror(bp, 0); | |
55b7d711 | 1276 | bp->b_flags |= (XBF_DONE | XBF_WRITE_FAIL); |
3cc49884 | 1277 | xfs_buf_submit(bp); |
70796c6b | 1278 | return true; |
664ffb8a CH |
1279 | out_stale: |
1280 | xfs_buf_stale(bp); | |
1281 | bp->b_flags |= XBF_DONE; | |
55b7d711 | 1282 | bp->b_flags &= ~XBF_WRITE; |
664ffb8a | 1283 | trace_xfs_buf_error_relse(bp, _RET_IP_); |
70796c6b | 1284 | return false; |
664ffb8a | 1285 | } |
1da177e4 | 1286 | |
76b2d323 | 1287 | static void |
e8aaba9a DC |
1288 | xfs_buf_ioend( |
1289 | struct xfs_buf *bp) | |
1da177e4 | 1290 | { |
e8aaba9a | 1291 | trace_xfs_buf_iodone(bp, _RET_IP_); |
1813dd64 | 1292 | |
61be9c52 DC |
1293 | /* |
1294 | * Pull in IO completion errors now. We are guaranteed to be running | |
1295 | * single threaded, so we don't need the lock to read b_io_error. | |
1296 | */ | |
1297 | if (!bp->b_error && bp->b_io_error) | |
1298 | xfs_buf_ioerror(bp, bp->b_io_error); | |
1299 | ||
55b7d711 | 1300 | if (bp->b_flags & XBF_READ) { |
b01d1461 DC |
1301 | if (!bp->b_error && bp->b_ops) |
1302 | bp->b_ops->verify_read(bp); | |
1303 | if (!bp->b_error) | |
1304 | bp->b_flags |= XBF_DONE; | |
23fb5a93 CH |
1305 | } else { |
1306 | if (!bp->b_error) { | |
1307 | bp->b_flags &= ~XBF_WRITE_FAIL; | |
1308 | bp->b_flags |= XBF_DONE; | |
1309 | } | |
f593bf14 | 1310 | |
70796c6b | 1311 | if (unlikely(bp->b_error) && xfs_buf_ioend_handle_error(bp)) |
664ffb8a | 1312 | return; |
664ffb8a CH |
1313 | |
1314 | /* clear the retry state */ | |
1315 | bp->b_last_error = 0; | |
1316 | bp->b_retries = 0; | |
1317 | bp->b_first_retry_time = 0; | |
1318 | ||
1319 | /* | |
1320 | * Note that for things like remote attribute buffers, there may | |
1321 | * not be a buffer log item here, so processing the buffer log | |
1322 | * item must remain optional. | |
1323 | */ | |
1324 | if (bp->b_log_item) | |
1325 | xfs_buf_item_done(bp); | |
1326 | ||
23fb5a93 CH |
1327 | if (bp->b_flags & _XBF_INODES) |
1328 | xfs_buf_inode_iodone(bp); | |
1329 | else if (bp->b_flags & _XBF_DQUOTS) | |
1330 | xfs_buf_dquot_iodone(bp); | |
22c10589 | 1331 | |
0c7e5afb | 1332 | } |
6a7584b1 | 1333 | |
22c10589 CH |
1334 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD | |
1335 | _XBF_LOGRECOVERY); | |
55b7d711 | 1336 | |
6a7584b1 CH |
1337 | if (bp->b_flags & XBF_ASYNC) |
1338 | xfs_buf_relse(bp); | |
1339 | else | |
1340 | complete(&bp->b_iowait); | |
1da177e4 LT |
1341 | } |
1342 | ||
e8aaba9a DC |
1343 | static void |
1344 | xfs_buf_ioend_work( | |
1345 | struct work_struct *work) | |
1da177e4 | 1346 | { |
e8aaba9a | 1347 | struct xfs_buf *bp = |
e8222613 | 1348 | container_of(work, struct xfs_buf, b_ioend_work); |
0b1b213f | 1349 | |
e8aaba9a DC |
1350 | xfs_buf_ioend(bp); |
1351 | } | |
1da177e4 | 1352 | |
211fe1a4 | 1353 | static void |
e8aaba9a DC |
1354 | xfs_buf_ioend_async( |
1355 | struct xfs_buf *bp) | |
1356 | { | |
b29c70f5 | 1357 | INIT_WORK(&bp->b_ioend_work, xfs_buf_ioend_work); |
dbd329f1 | 1358 | queue_work(bp->b_mount->m_buf_workqueue, &bp->b_ioend_work); |
1da177e4 LT |
1359 | } |
1360 | ||
1da177e4 | 1361 | void |
31ca03c9 | 1362 | __xfs_buf_ioerror( |
e8222613 | 1363 | struct xfs_buf *bp, |
31ca03c9 DW |
1364 | int error, |
1365 | xfs_failaddr_t failaddr) | |
1da177e4 | 1366 | { |
2451337d DC |
1367 | ASSERT(error <= 0 && error >= -1000); |
1368 | bp->b_error = error; | |
31ca03c9 | 1369 | trace_xfs_buf_ioerror(bp, error, failaddr); |
1da177e4 LT |
1370 | } |
1371 | ||
901796af CH |
1372 | void |
1373 | xfs_buf_ioerror_alert( | |
1374 | struct xfs_buf *bp, | |
cdbcf82b | 1375 | xfs_failaddr_t func) |
901796af | 1376 | { |
f9bccfcc BF |
1377 | xfs_buf_alert_ratelimited(bp, "XFS: metadata IO error", |
1378 | "metadata I/O error in \"%pS\" at daddr 0x%llx len %d error %d", | |
04fcad80 | 1379 | func, (uint64_t)xfs_buf_daddr(bp), |
f9bccfcc | 1380 | bp->b_length, -bp->b_error); |
901796af CH |
1381 | } |
1382 | ||
54b3b1f6 BF |
1383 | /* |
1384 | * To simulate an I/O failure, the buffer must be locked and held with at least | |
1385 | * three references. The LRU reference is dropped by the stale call. The buf | |
1386 | * item reference is dropped via ioend processing. The third reference is owned | |
1387 | * by the caller and is dropped on I/O completion if the buffer is XBF_ASYNC. | |
1388 | */ | |
1389 | void | |
1390 | xfs_buf_ioend_fail( | |
1391 | struct xfs_buf *bp) | |
1392 | { | |
1393 | bp->b_flags &= ~XBF_DONE; | |
1394 | xfs_buf_stale(bp); | |
1395 | xfs_buf_ioerror(bp, -EIO); | |
1396 | xfs_buf_ioend(bp); | |
901796af CH |
1397 | } |
1398 | ||
a2dcf5df CH |
1399 | int |
1400 | xfs_bwrite( | |
1401 | struct xfs_buf *bp) | |
1402 | { | |
1403 | int error; | |
1404 | ||
1405 | ASSERT(xfs_buf_islocked(bp)); | |
1406 | ||
1407 | bp->b_flags |= XBF_WRITE; | |
27187754 | 1408 | bp->b_flags &= ~(XBF_ASYNC | XBF_READ | _XBF_DELWRI_Q | |
b6983e80 | 1409 | XBF_DONE); |
a2dcf5df | 1410 | |
6af88cda | 1411 | error = xfs_buf_submit(bp); |
dbd329f1 CH |
1412 | if (error) |
1413 | xfs_force_shutdown(bp->b_mount, SHUTDOWN_META_IO_ERROR); | |
a2dcf5df CH |
1414 | return error; |
1415 | } | |
1416 | ||
9bdd9bd6 | 1417 | static void |
ce8e922c | 1418 | xfs_buf_bio_end_io( |
4246a0b6 | 1419 | struct bio *bio) |
1da177e4 | 1420 | { |
9bdd9bd6 | 1421 | struct xfs_buf *bp = (struct xfs_buf *)bio->bi_private; |
1da177e4 | 1422 | |
7376d745 BF |
1423 | if (!bio->bi_status && |
1424 | (bp->b_flags & XBF_WRITE) && (bp->b_flags & XBF_ASYNC) && | |
43dc0aa8 | 1425 | XFS_TEST_ERROR(false, bp->b_mount, XFS_ERRTAG_BUF_IOERROR)) |
7376d745 | 1426 | bio->bi_status = BLK_STS_IOERR; |
1da177e4 | 1427 | |
37eb17e6 DC |
1428 | /* |
1429 | * don't overwrite existing errors - otherwise we can lose errors on | |
1430 | * buffers that require multiple bios to complete. | |
1431 | */ | |
4e4cbee9 CH |
1432 | if (bio->bi_status) { |
1433 | int error = blk_status_to_errno(bio->bi_status); | |
1434 | ||
1435 | cmpxchg(&bp->b_io_error, 0, error); | |
1436 | } | |
1da177e4 | 1437 | |
37eb17e6 | 1438 | if (!bp->b_error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ)) |
73c77e2c JB |
1439 | invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp)); |
1440 | ||
e8aaba9a DC |
1441 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) |
1442 | xfs_buf_ioend_async(bp); | |
1da177e4 | 1443 | bio_put(bio); |
1da177e4 LT |
1444 | } |
1445 | ||
3e85c868 DC |
1446 | static void |
1447 | xfs_buf_ioapply_map( | |
1448 | struct xfs_buf *bp, | |
1449 | int map, | |
1450 | int *buf_offset, | |
1451 | int *count, | |
d03025ae | 1452 | blk_opf_t op) |
1da177e4 | 1453 | { |
3e85c868 | 1454 | int page_index; |
5f7136db | 1455 | unsigned int total_nr_pages = bp->b_page_count; |
3e85c868 DC |
1456 | int nr_pages; |
1457 | struct bio *bio; | |
1458 | sector_t sector = bp->b_maps[map].bm_bn; | |
1459 | int size; | |
1460 | int offset; | |
1da177e4 | 1461 | |
3e85c868 DC |
1462 | /* skip the pages in the buffer before the start offset */ |
1463 | page_index = 0; | |
1464 | offset = *buf_offset; | |
1465 | while (offset >= PAGE_SIZE) { | |
1466 | page_index++; | |
1467 | offset -= PAGE_SIZE; | |
f538d4da CH |
1468 | } |
1469 | ||
3e85c868 DC |
1470 | /* |
1471 | * Limit the IO size to the length of the current vector, and update the | |
1472 | * remaining IO count for the next time around. | |
1473 | */ | |
1474 | size = min_t(int, BBTOB(bp->b_maps[map].bm_len), *count); | |
1475 | *count -= size; | |
1476 | *buf_offset += size; | |
34951f5c | 1477 | |
1da177e4 | 1478 | next_chunk: |
ce8e922c | 1479 | atomic_inc(&bp->b_io_remaining); |
5f7136db | 1480 | nr_pages = bio_max_segs(total_nr_pages); |
1da177e4 | 1481 | |
07888c66 | 1482 | bio = bio_alloc(bp->b_target->bt_bdev, nr_pages, op, GFP_NOIO); |
4f024f37 | 1483 | bio->bi_iter.bi_sector = sector; |
ce8e922c NS |
1484 | bio->bi_end_io = xfs_buf_bio_end_io; |
1485 | bio->bi_private = bp; | |
0e6e847f | 1486 | |
3e85c868 | 1487 | for (; size && nr_pages; nr_pages--, page_index++) { |
0e6e847f | 1488 | int rbytes, nbytes = PAGE_SIZE - offset; |
1da177e4 LT |
1489 | |
1490 | if (nbytes > size) | |
1491 | nbytes = size; | |
1492 | ||
3e85c868 DC |
1493 | rbytes = bio_add_page(bio, bp->b_pages[page_index], nbytes, |
1494 | offset); | |
ce8e922c | 1495 | if (rbytes < nbytes) |
1da177e4 LT |
1496 | break; |
1497 | ||
1498 | offset = 0; | |
aa0e8833 | 1499 | sector += BTOBB(nbytes); |
1da177e4 LT |
1500 | size -= nbytes; |
1501 | total_nr_pages--; | |
1502 | } | |
1503 | ||
4f024f37 | 1504 | if (likely(bio->bi_iter.bi_size)) { |
73c77e2c JB |
1505 | if (xfs_buf_is_vmapped(bp)) { |
1506 | flush_kernel_vmap_range(bp->b_addr, | |
1507 | xfs_buf_vmap_len(bp)); | |
1508 | } | |
4e49ea4a | 1509 | submit_bio(bio); |
1da177e4 LT |
1510 | if (size) |
1511 | goto next_chunk; | |
1512 | } else { | |
37eb17e6 DC |
1513 | /* |
1514 | * This is guaranteed not to be the last io reference count | |
595bff75 | 1515 | * because the caller (xfs_buf_submit) holds a count itself. |
37eb17e6 DC |
1516 | */ |
1517 | atomic_dec(&bp->b_io_remaining); | |
2451337d | 1518 | xfs_buf_ioerror(bp, -EIO); |
ec53d1db | 1519 | bio_put(bio); |
1da177e4 | 1520 | } |
3e85c868 DC |
1521 | |
1522 | } | |
1523 | ||
1524 | STATIC void | |
1525 | _xfs_buf_ioapply( | |
1526 | struct xfs_buf *bp) | |
1527 | { | |
1528 | struct blk_plug plug; | |
d03025ae | 1529 | blk_opf_t op; |
3e85c868 DC |
1530 | int offset; |
1531 | int size; | |
1532 | int i; | |
1533 | ||
c163f9a1 DC |
1534 | /* |
1535 | * Make sure we capture only current IO errors rather than stale errors | |
1536 | * left over from previous use of the buffer (e.g. failed readahead). | |
1537 | */ | |
1538 | bp->b_error = 0; | |
1539 | ||
3e85c868 | 1540 | if (bp->b_flags & XBF_WRITE) { |
50bfcd0c | 1541 | op = REQ_OP_WRITE; |
1813dd64 DC |
1542 | |
1543 | /* | |
1544 | * Run the write verifier callback function if it exists. If | |
1545 | * this function fails it will mark the buffer with an error and | |
1546 | * the IO should not be dispatched. | |
1547 | */ | |
1548 | if (bp->b_ops) { | |
1549 | bp->b_ops->verify_write(bp); | |
1550 | if (bp->b_error) { | |
dbd329f1 | 1551 | xfs_force_shutdown(bp->b_mount, |
1813dd64 DC |
1552 | SHUTDOWN_CORRUPT_INCORE); |
1553 | return; | |
1554 | } | |
4c7f65ae | 1555 | } else if (bp->b_rhash_key != XFS_BUF_DADDR_NULL) { |
dbd329f1 | 1556 | struct xfs_mount *mp = bp->b_mount; |
400b9d88 DC |
1557 | |
1558 | /* | |
1559 | * non-crc filesystems don't attach verifiers during | |
1560 | * log recovery, so don't warn for such filesystems. | |
1561 | */ | |
38c26bfd | 1562 | if (xfs_has_crc(mp)) { |
400b9d88 | 1563 | xfs_warn(mp, |
c219b015 | 1564 | "%s: no buf ops on daddr 0x%llx len %d", |
4c7f65ae DC |
1565 | __func__, xfs_buf_daddr(bp), |
1566 | bp->b_length); | |
9c712a13 DW |
1567 | xfs_hex_dump(bp->b_addr, |
1568 | XFS_CORRUPTION_DUMP_LEN); | |
400b9d88 DC |
1569 | dump_stack(); |
1570 | } | |
1813dd64 | 1571 | } |
3e85c868 | 1572 | } else { |
50bfcd0c | 1573 | op = REQ_OP_READ; |
2123ef85 CH |
1574 | if (bp->b_flags & XBF_READ_AHEAD) |
1575 | op |= REQ_RAHEAD; | |
3e85c868 DC |
1576 | } |
1577 | ||
1578 | /* we only use the buffer cache for meta-data */ | |
2123ef85 | 1579 | op |= REQ_META; |
3e85c868 DC |
1580 | |
1581 | /* | |
1582 | * Walk all the vectors issuing IO on them. Set up the initial offset | |
1583 | * into the buffer and the desired IO size before we start - | |
1584 | * _xfs_buf_ioapply_vec() will modify them appropriately for each | |
1585 | * subsequent call. | |
1586 | */ | |
1587 | offset = bp->b_offset; | |
8124b9b6 | 1588 | size = BBTOB(bp->b_length); |
3e85c868 DC |
1589 | blk_start_plug(&plug); |
1590 | for (i = 0; i < bp->b_map_count; i++) { | |
2123ef85 | 1591 | xfs_buf_ioapply_map(bp, i, &offset, &size, op); |
3e85c868 DC |
1592 | if (bp->b_error) |
1593 | break; | |
1594 | if (size <= 0) | |
1595 | break; /* all done */ | |
1596 | } | |
1597 | blk_finish_plug(&plug); | |
1da177e4 LT |
1598 | } |
1599 | ||
595bff75 | 1600 | /* |
bb00b6f1 | 1601 | * Wait for I/O completion of a sync buffer and return the I/O error code. |
595bff75 | 1602 | */ |
eaebb515 | 1603 | static int |
bb00b6f1 | 1604 | xfs_buf_iowait( |
595bff75 | 1605 | struct xfs_buf *bp) |
1da177e4 | 1606 | { |
bb00b6f1 BF |
1607 | ASSERT(!(bp->b_flags & XBF_ASYNC)); |
1608 | ||
1609 | trace_xfs_buf_iowait(bp, _RET_IP_); | |
1610 | wait_for_completion(&bp->b_iowait); | |
1611 | trace_xfs_buf_iowait_done(bp, _RET_IP_); | |
1612 | ||
1613 | return bp->b_error; | |
1614 | } | |
1615 | ||
1616 | /* | |
1617 | * Buffer I/O submission path, read or write. Asynchronous submission transfers | |
1618 | * the buffer lock ownership and the current reference to the IO. It is not | |
1619 | * safe to reference the buffer after a call to this function unless the caller | |
1620 | * holds an additional reference itself. | |
1621 | */ | |
26e32875 | 1622 | static int |
bb00b6f1 BF |
1623 | __xfs_buf_submit( |
1624 | struct xfs_buf *bp, | |
1625 | bool wait) | |
1626 | { | |
1627 | int error = 0; | |
1628 | ||
595bff75 | 1629 | trace_xfs_buf_submit(bp, _RET_IP_); |
1da177e4 | 1630 | |
43ff2122 | 1631 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); |
595bff75 | 1632 | |
01728b44 DC |
1633 | /* |
1634 | * On log shutdown we stale and complete the buffer immediately. We can | |
1635 | * be called to read the superblock before the log has been set up, so | |
1636 | * be careful checking the log state. | |
1637 | * | |
1638 | * Checking the mount shutdown state here can result in the log tail | |
1639 | * moving inappropriately on disk as the log may not yet be shut down. | |
1640 | * i.e. failing this buffer on mount shutdown can remove it from the AIL | |
1641 | * and move the tail of the log forwards without having written this | |
1642 | * buffer to disk. This corrupts the log tail state in memory, and | |
1643 | * because the log may not be shut down yet, it can then be propagated | |
1644 | * to disk before the log is shutdown. Hence we check log shutdown | |
1645 | * state here rather than mount state to avoid corrupting the log tail | |
1646 | * on shutdown. | |
1647 | */ | |
1648 | if (bp->b_mount->m_log && | |
1649 | xlog_is_shutdown(bp->b_mount->m_log)) { | |
54b3b1f6 | 1650 | xfs_buf_ioend_fail(bp); |
eaebb515 | 1651 | return -EIO; |
595bff75 | 1652 | } |
1da177e4 | 1653 | |
bb00b6f1 BF |
1654 | /* |
1655 | * Grab a reference so the buffer does not go away underneath us. For | |
1656 | * async buffers, I/O completion drops the callers reference, which | |
1657 | * could occur before submission returns. | |
1658 | */ | |
1659 | xfs_buf_hold(bp); | |
1660 | ||
375ec69d | 1661 | if (bp->b_flags & XBF_WRITE) |
ce8e922c | 1662 | xfs_buf_wait_unpin(bp); |
e11bb805 | 1663 | |
61be9c52 DC |
1664 | /* clear the internal error state to avoid spurious errors */ |
1665 | bp->b_io_error = 0; | |
1666 | ||
8d6c1210 | 1667 | /* |
e11bb805 DC |
1668 | * Set the count to 1 initially, this will stop an I/O completion |
1669 | * callout which happens before we have started all the I/O from calling | |
1670 | * xfs_buf_ioend too early. | |
1da177e4 | 1671 | */ |
ce8e922c | 1672 | atomic_set(&bp->b_io_remaining, 1); |
eaebb515 BF |
1673 | if (bp->b_flags & XBF_ASYNC) |
1674 | xfs_buf_ioacct_inc(bp); | |
ce8e922c | 1675 | _xfs_buf_ioapply(bp); |
e11bb805 | 1676 | |
8d6c1210 | 1677 | /* |
595bff75 DC |
1678 | * If _xfs_buf_ioapply failed, we can get back here with only the IO |
1679 | * reference we took above. If we drop it to zero, run completion so | |
1680 | * that we don't return to the caller with completion still pending. | |
8d6c1210 | 1681 | */ |
e8aaba9a | 1682 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) { |
eaebb515 | 1683 | if (bp->b_error || !(bp->b_flags & XBF_ASYNC)) |
e8aaba9a DC |
1684 | xfs_buf_ioend(bp); |
1685 | else | |
1686 | xfs_buf_ioend_async(bp); | |
1687 | } | |
1da177e4 | 1688 | |
6af88cda BF |
1689 | if (wait) |
1690 | error = xfs_buf_iowait(bp); | |
bb00b6f1 | 1691 | |
595bff75 | 1692 | /* |
6af88cda BF |
1693 | * Release the hold that keeps the buffer referenced for the entire |
1694 | * I/O. Note that if the buffer is async, it is not safe to reference | |
1695 | * after this release. | |
595bff75 DC |
1696 | */ |
1697 | xfs_buf_rele(bp); | |
1698 | return error; | |
1da177e4 LT |
1699 | } |
1700 | ||
88ee2df7 | 1701 | void * |
ce8e922c | 1702 | xfs_buf_offset( |
88ee2df7 | 1703 | struct xfs_buf *bp, |
1da177e4 LT |
1704 | size_t offset) |
1705 | { | |
1706 | struct page *page; | |
1707 | ||
611c9946 | 1708 | if (bp->b_addr) |
62926044 | 1709 | return bp->b_addr + offset; |
1da177e4 | 1710 | |
0e6e847f | 1711 | page = bp->b_pages[offset >> PAGE_SHIFT]; |
88ee2df7 | 1712 | return page_address(page) + (offset & (PAGE_SIZE-1)); |
1da177e4 LT |
1713 | } |
1714 | ||
1da177e4 | 1715 | void |
f9a196ee CH |
1716 | xfs_buf_zero( |
1717 | struct xfs_buf *bp, | |
1718 | size_t boff, | |
1719 | size_t bsize) | |
1da177e4 | 1720 | { |
795cac72 | 1721 | size_t bend; |
1da177e4 LT |
1722 | |
1723 | bend = boff + bsize; | |
1724 | while (boff < bend) { | |
795cac72 DC |
1725 | struct page *page; |
1726 | int page_index, page_offset, csize; | |
1727 | ||
1728 | page_index = (boff + bp->b_offset) >> PAGE_SHIFT; | |
1729 | page_offset = (boff + bp->b_offset) & ~PAGE_MASK; | |
1730 | page = bp->b_pages[page_index]; | |
1731 | csize = min_t(size_t, PAGE_SIZE - page_offset, | |
8124b9b6 | 1732 | BBTOB(bp->b_length) - boff); |
1da177e4 | 1733 | |
795cac72 | 1734 | ASSERT((csize + page_offset) <= PAGE_SIZE); |
1da177e4 | 1735 | |
f9a196ee | 1736 | memset(page_address(page) + page_offset, 0, csize); |
1da177e4 LT |
1737 | |
1738 | boff += csize; | |
1da177e4 LT |
1739 | } |
1740 | } | |
1741 | ||
8d57c216 DW |
1742 | /* |
1743 | * Log a message about and stale a buffer that a caller has decided is corrupt. | |
1744 | * | |
1745 | * This function should be called for the kinds of metadata corruption that | |
1746 | * cannot be detect from a verifier, such as incorrect inter-block relationship | |
1747 | * data. Do /not/ call this function from a verifier function. | |
1748 | * | |
1749 | * The buffer must be XBF_DONE prior to the call. Afterwards, the buffer will | |
1750 | * be marked stale, but b_error will not be set. The caller is responsible for | |
1751 | * releasing the buffer or fixing it. | |
1752 | */ | |
1753 | void | |
1754 | __xfs_buf_mark_corrupt( | |
1755 | struct xfs_buf *bp, | |
1756 | xfs_failaddr_t fa) | |
1757 | { | |
1758 | ASSERT(bp->b_flags & XBF_DONE); | |
1759 | ||
e83cf875 | 1760 | xfs_buf_corruption_error(bp, fa); |
8d57c216 DW |
1761 | xfs_buf_stale(bp); |
1762 | } | |
1763 | ||
1da177e4 | 1764 | /* |
ce8e922c | 1765 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1766 | */ |
1767 | ||
1768 | /* | |
430cbeb8 DC |
1769 | * Wait for any bufs with callbacks that have been submitted but have not yet |
1770 | * returned. These buffers will have an elevated hold count, so wait on those | |
1771 | * while freeing all the buffers only held by the LRU. | |
1da177e4 | 1772 | */ |
e80dfa19 | 1773 | static enum lru_status |
10fb9ac1 | 1774 | xfs_buftarg_drain_rele( |
e80dfa19 | 1775 | struct list_head *item, |
3f97b163 | 1776 | struct list_lru_one *lru, |
e80dfa19 DC |
1777 | spinlock_t *lru_lock, |
1778 | void *arg) | |
1779 | ||
1da177e4 | 1780 | { |
e80dfa19 | 1781 | struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru); |
a4082357 | 1782 | struct list_head *dispose = arg; |
430cbeb8 | 1783 | |
e80dfa19 | 1784 | if (atomic_read(&bp->b_hold) > 1) { |
a4082357 | 1785 | /* need to wait, so skip it this pass */ |
10fb9ac1 | 1786 | trace_xfs_buf_drain_buftarg(bp, _RET_IP_); |
a4082357 | 1787 | return LRU_SKIP; |
1da177e4 | 1788 | } |
a4082357 DC |
1789 | if (!spin_trylock(&bp->b_lock)) |
1790 | return LRU_SKIP; | |
e80dfa19 | 1791 | |
a4082357 DC |
1792 | /* |
1793 | * clear the LRU reference count so the buffer doesn't get | |
1794 | * ignored in xfs_buf_rele(). | |
1795 | */ | |
1796 | atomic_set(&bp->b_lru_ref, 0); | |
1797 | bp->b_state |= XFS_BSTATE_DISPOSE; | |
3f97b163 | 1798 | list_lru_isolate_move(lru, item, dispose); |
a4082357 DC |
1799 | spin_unlock(&bp->b_lock); |
1800 | return LRU_REMOVED; | |
1da177e4 LT |
1801 | } |
1802 | ||
8321ddb2 BF |
1803 | /* |
1804 | * Wait for outstanding I/O on the buftarg to complete. | |
1805 | */ | |
e80dfa19 | 1806 | void |
8321ddb2 | 1807 | xfs_buftarg_wait( |
e80dfa19 DC |
1808 | struct xfs_buftarg *btp) |
1809 | { | |
85bec546 | 1810 | /* |
9c7504aa BF |
1811 | * First wait on the buftarg I/O count for all in-flight buffers to be |
1812 | * released. This is critical as new buffers do not make the LRU until | |
1813 | * they are released. | |
1814 | * | |
1815 | * Next, flush the buffer workqueue to ensure all completion processing | |
1816 | * has finished. Just waiting on buffer locks is not sufficient for | |
1817 | * async IO as the reference count held over IO is not released until | |
1818 | * after the buffer lock is dropped. Hence we need to ensure here that | |
1819 | * all reference counts have been dropped before we start walking the | |
1820 | * LRU list. | |
85bec546 | 1821 | */ |
9c7504aa BF |
1822 | while (percpu_counter_sum(&btp->bt_io_count)) |
1823 | delay(100); | |
800b2694 | 1824 | flush_workqueue(btp->bt_mount->m_buf_workqueue); |
8321ddb2 BF |
1825 | } |
1826 | ||
1827 | void | |
1828 | xfs_buftarg_drain( | |
1829 | struct xfs_buftarg *btp) | |
1830 | { | |
1831 | LIST_HEAD(dispose); | |
1832 | int loop = 0; | |
1833 | bool write_fail = false; | |
1834 | ||
1835 | xfs_buftarg_wait(btp); | |
85bec546 | 1836 | |
a4082357 DC |
1837 | /* loop until there is nothing left on the lru list. */ |
1838 | while (list_lru_count(&btp->bt_lru)) { | |
10fb9ac1 | 1839 | list_lru_walk(&btp->bt_lru, xfs_buftarg_drain_rele, |
a4082357 DC |
1840 | &dispose, LONG_MAX); |
1841 | ||
1842 | while (!list_empty(&dispose)) { | |
1843 | struct xfs_buf *bp; | |
1844 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); | |
1845 | list_del_init(&bp->b_lru); | |
ac8809f9 | 1846 | if (bp->b_flags & XBF_WRITE_FAIL) { |
61948b6f BF |
1847 | write_fail = true; |
1848 | xfs_buf_alert_ratelimited(bp, | |
1849 | "XFS: Corruption Alert", | |
c219b015 | 1850 | "Corruption Alert: Buffer at daddr 0x%llx had permanent write failures!", |
4c7f65ae | 1851 | (long long)xfs_buf_daddr(bp)); |
ac8809f9 | 1852 | } |
a4082357 DC |
1853 | xfs_buf_rele(bp); |
1854 | } | |
1855 | if (loop++ != 0) | |
1856 | delay(100); | |
1857 | } | |
61948b6f BF |
1858 | |
1859 | /* | |
1860 | * If one or more failed buffers were freed, that means dirty metadata | |
1861 | * was thrown away. This should only ever happen after I/O completion | |
1862 | * handling has elevated I/O error(s) to permanent failures and shuts | |
01728b44 | 1863 | * down the journal. |
61948b6f BF |
1864 | */ |
1865 | if (write_fail) { | |
01728b44 | 1866 | ASSERT(xlog_is_shutdown(btp->bt_mount->m_log)); |
61948b6f BF |
1867 | xfs_alert(btp->bt_mount, |
1868 | "Please run xfs_repair to determine the extent of the problem."); | |
1869 | } | |
e80dfa19 DC |
1870 | } |
1871 | ||
1872 | static enum lru_status | |
1873 | xfs_buftarg_isolate( | |
1874 | struct list_head *item, | |
3f97b163 | 1875 | struct list_lru_one *lru, |
e80dfa19 DC |
1876 | spinlock_t *lru_lock, |
1877 | void *arg) | |
1878 | { | |
1879 | struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru); | |
1880 | struct list_head *dispose = arg; | |
1881 | ||
a4082357 DC |
1882 | /* |
1883 | * we are inverting the lru lock/bp->b_lock here, so use a trylock. | |
1884 | * If we fail to get the lock, just skip it. | |
1885 | */ | |
1886 | if (!spin_trylock(&bp->b_lock)) | |
1887 | return LRU_SKIP; | |
e80dfa19 DC |
1888 | /* |
1889 | * Decrement the b_lru_ref count unless the value is already | |
1890 | * zero. If the value is already zero, we need to reclaim the | |
1891 | * buffer, otherwise it gets another trip through the LRU. | |
1892 | */ | |
19957a18 | 1893 | if (atomic_add_unless(&bp->b_lru_ref, -1, 0)) { |
a4082357 | 1894 | spin_unlock(&bp->b_lock); |
e80dfa19 | 1895 | return LRU_ROTATE; |
a4082357 | 1896 | } |
e80dfa19 | 1897 | |
a4082357 | 1898 | bp->b_state |= XFS_BSTATE_DISPOSE; |
3f97b163 | 1899 | list_lru_isolate_move(lru, item, dispose); |
a4082357 | 1900 | spin_unlock(&bp->b_lock); |
e80dfa19 DC |
1901 | return LRU_REMOVED; |
1902 | } | |
1903 | ||
addbda40 | 1904 | static unsigned long |
e80dfa19 | 1905 | xfs_buftarg_shrink_scan( |
ff57ab21 | 1906 | struct shrinker *shrink, |
1495f230 | 1907 | struct shrink_control *sc) |
a6867a68 | 1908 | { |
ff57ab21 DC |
1909 | struct xfs_buftarg *btp = container_of(shrink, |
1910 | struct xfs_buftarg, bt_shrinker); | |
430cbeb8 | 1911 | LIST_HEAD(dispose); |
addbda40 | 1912 | unsigned long freed; |
430cbeb8 | 1913 | |
503c358c VD |
1914 | freed = list_lru_shrink_walk(&btp->bt_lru, sc, |
1915 | xfs_buftarg_isolate, &dispose); | |
430cbeb8 DC |
1916 | |
1917 | while (!list_empty(&dispose)) { | |
e80dfa19 | 1918 | struct xfs_buf *bp; |
430cbeb8 DC |
1919 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); |
1920 | list_del_init(&bp->b_lru); | |
1921 | xfs_buf_rele(bp); | |
1922 | } | |
1923 | ||
e80dfa19 DC |
1924 | return freed; |
1925 | } | |
1926 | ||
addbda40 | 1927 | static unsigned long |
e80dfa19 DC |
1928 | xfs_buftarg_shrink_count( |
1929 | struct shrinker *shrink, | |
1930 | struct shrink_control *sc) | |
1931 | { | |
1932 | struct xfs_buftarg *btp = container_of(shrink, | |
1933 | struct xfs_buftarg, bt_shrinker); | |
503c358c | 1934 | return list_lru_shrink_count(&btp->bt_lru, sc); |
a6867a68 DC |
1935 | } |
1936 | ||
1da177e4 LT |
1937 | void |
1938 | xfs_free_buftarg( | |
b7963133 | 1939 | struct xfs_buftarg *btp) |
1da177e4 | 1940 | { |
ff57ab21 | 1941 | unregister_shrinker(&btp->bt_shrinker); |
9c7504aa BF |
1942 | ASSERT(percpu_counter_sum(&btp->bt_io_count) == 0); |
1943 | percpu_counter_destroy(&btp->bt_io_count); | |
f5e1dd34 | 1944 | list_lru_destroy(&btp->bt_lru); |
ff57ab21 | 1945 | |
b5071ada | 1946 | blkdev_issue_flush(btp->bt_bdev); |
032e1603 | 1947 | invalidate_bdev(btp->bt_bdev); |
6f643c57 | 1948 | fs_put_dax(btp->bt_daxdev, btp->bt_mount); |
a6867a68 | 1949 | |
f0e2d93c | 1950 | kmem_free(btp); |
1da177e4 LT |
1951 | } |
1952 | ||
3fefdeee ES |
1953 | int |
1954 | xfs_setsize_buftarg( | |
1da177e4 | 1955 | xfs_buftarg_t *btp, |
3fefdeee | 1956 | unsigned int sectorsize) |
1da177e4 | 1957 | { |
7c71ee78 | 1958 | /* Set up metadata sector size info */ |
6da54179 ES |
1959 | btp->bt_meta_sectorsize = sectorsize; |
1960 | btp->bt_meta_sectormask = sectorsize - 1; | |
1da177e4 | 1961 | |
ce8e922c | 1962 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
4f10700a | 1963 | xfs_warn(btp->bt_mount, |
a1c6f057 DM |
1964 | "Cannot set_blocksize to %u on device %pg", |
1965 | sectorsize, btp->bt_bdev); | |
2451337d | 1966 | return -EINVAL; |
1da177e4 LT |
1967 | } |
1968 | ||
7c71ee78 ES |
1969 | /* Set up device logical sector size mask */ |
1970 | btp->bt_logical_sectorsize = bdev_logical_block_size(btp->bt_bdev); | |
1971 | btp->bt_logical_sectormask = bdev_logical_block_size(btp->bt_bdev) - 1; | |
1972 | ||
1da177e4 LT |
1973 | return 0; |
1974 | } | |
1975 | ||
1976 | /* | |
3fefdeee ES |
1977 | * When allocating the initial buffer target we have not yet |
1978 | * read in the superblock, so don't know what sized sectors | |
1979 | * are being used at this early stage. Play safe. | |
ce8e922c | 1980 | */ |
1da177e4 LT |
1981 | STATIC int |
1982 | xfs_setsize_buftarg_early( | |
1983 | xfs_buftarg_t *btp, | |
1984 | struct block_device *bdev) | |
1985 | { | |
a96c4151 | 1986 | return xfs_setsize_buftarg(btp, bdev_logical_block_size(bdev)); |
1da177e4 LT |
1987 | } |
1988 | ||
5b5abbef | 1989 | struct xfs_buftarg * |
1da177e4 | 1990 | xfs_alloc_buftarg( |
ebad861b | 1991 | struct xfs_mount *mp, |
5b5abbef | 1992 | struct block_device *bdev) |
1da177e4 LT |
1993 | { |
1994 | xfs_buftarg_t *btp; | |
6f643c57 | 1995 | const struct dax_holder_operations *ops = NULL; |
1da177e4 | 1996 | |
6f643c57 SR |
1997 | #if defined(CONFIG_FS_DAX) && defined(CONFIG_MEMORY_FAILURE) |
1998 | ops = &xfs_dax_holder_operations; | |
1999 | #endif | |
707e0dda | 2000 | btp = kmem_zalloc(sizeof(*btp), KM_NOFS); |
1da177e4 | 2001 | |
ebad861b | 2002 | btp->bt_mount = mp; |
ce8e922c NS |
2003 | btp->bt_dev = bdev->bd_dev; |
2004 | btp->bt_bdev = bdev; | |
6f643c57 SR |
2005 | btp->bt_daxdev = fs_dax_get_by_bdev(bdev, &btp->bt_dax_part_off, |
2006 | mp, ops); | |
0e6e847f | 2007 | |
f9bccfcc BF |
2008 | /* |
2009 | * Buffer IO error rate limiting. Limit it to no more than 10 messages | |
2010 | * per 30 seconds so as to not spam logs too much on repeated errors. | |
2011 | */ | |
2012 | ratelimit_state_init(&btp->bt_ioerror_rl, 30 * HZ, | |
2013 | DEFAULT_RATELIMIT_BURST); | |
2014 | ||
1da177e4 | 2015 | if (xfs_setsize_buftarg_early(btp, bdev)) |
d210a987 | 2016 | goto error_free; |
5ca302c8 GC |
2017 | |
2018 | if (list_lru_init(&btp->bt_lru)) | |
d210a987 | 2019 | goto error_free; |
5ca302c8 | 2020 | |
9c7504aa | 2021 | if (percpu_counter_init(&btp->bt_io_count, 0, GFP_KERNEL)) |
d210a987 | 2022 | goto error_lru; |
9c7504aa | 2023 | |
e80dfa19 DC |
2024 | btp->bt_shrinker.count_objects = xfs_buftarg_shrink_count; |
2025 | btp->bt_shrinker.scan_objects = xfs_buftarg_shrink_scan; | |
ff57ab21 | 2026 | btp->bt_shrinker.seeks = DEFAULT_SEEKS; |
e80dfa19 | 2027 | btp->bt_shrinker.flags = SHRINKER_NUMA_AWARE; |
e33c267a RG |
2028 | if (register_shrinker(&btp->bt_shrinker, "xfs-buf:%s", |
2029 | mp->m_super->s_id)) | |
d210a987 | 2030 | goto error_pcpu; |
1da177e4 LT |
2031 | return btp; |
2032 | ||
d210a987 MH |
2033 | error_pcpu: |
2034 | percpu_counter_destroy(&btp->bt_io_count); | |
2035 | error_lru: | |
2036 | list_lru_destroy(&btp->bt_lru); | |
2037 | error_free: | |
f0e2d93c | 2038 | kmem_free(btp); |
1da177e4 LT |
2039 | return NULL; |
2040 | } | |
2041 | ||
20e8a063 BF |
2042 | /* |
2043 | * Cancel a delayed write list. | |
2044 | * | |
2045 | * Remove each buffer from the list, clear the delwri queue flag and drop the | |
2046 | * associated buffer reference. | |
2047 | */ | |
2048 | void | |
2049 | xfs_buf_delwri_cancel( | |
2050 | struct list_head *list) | |
2051 | { | |
2052 | struct xfs_buf *bp; | |
2053 | ||
2054 | while (!list_empty(list)) { | |
2055 | bp = list_first_entry(list, struct xfs_buf, b_list); | |
2056 | ||
2057 | xfs_buf_lock(bp); | |
2058 | bp->b_flags &= ~_XBF_DELWRI_Q; | |
2059 | list_del_init(&bp->b_list); | |
2060 | xfs_buf_relse(bp); | |
2061 | } | |
2062 | } | |
2063 | ||
1da177e4 | 2064 | /* |
43ff2122 CH |
2065 | * Add a buffer to the delayed write list. |
2066 | * | |
2067 | * This queues a buffer for writeout if it hasn't already been. Note that | |
2068 | * neither this routine nor the buffer list submission functions perform | |
2069 | * any internal synchronization. It is expected that the lists are thread-local | |
2070 | * to the callers. | |
2071 | * | |
2072 | * Returns true if we queued up the buffer, or false if it already had | |
2073 | * been on the buffer list. | |
1da177e4 | 2074 | */ |
43ff2122 | 2075 | bool |
ce8e922c | 2076 | xfs_buf_delwri_queue( |
43ff2122 CH |
2077 | struct xfs_buf *bp, |
2078 | struct list_head *list) | |
1da177e4 | 2079 | { |
43ff2122 | 2080 | ASSERT(xfs_buf_islocked(bp)); |
5a8ee6ba | 2081 | ASSERT(!(bp->b_flags & XBF_READ)); |
1da177e4 | 2082 | |
43ff2122 CH |
2083 | /* |
2084 | * If the buffer is already marked delwri it already is queued up | |
2085 | * by someone else for imediate writeout. Just ignore it in that | |
2086 | * case. | |
2087 | */ | |
2088 | if (bp->b_flags & _XBF_DELWRI_Q) { | |
2089 | trace_xfs_buf_delwri_queued(bp, _RET_IP_); | |
2090 | return false; | |
1da177e4 | 2091 | } |
1da177e4 | 2092 | |
43ff2122 | 2093 | trace_xfs_buf_delwri_queue(bp, _RET_IP_); |
d808f617 DC |
2094 | |
2095 | /* | |
43ff2122 CH |
2096 | * If a buffer gets written out synchronously or marked stale while it |
2097 | * is on a delwri list we lazily remove it. To do this, the other party | |
2098 | * clears the _XBF_DELWRI_Q flag but otherwise leaves the buffer alone. | |
2099 | * It remains referenced and on the list. In a rare corner case it | |
2100 | * might get readded to a delwri list after the synchronous writeout, in | |
2101 | * which case we need just need to re-add the flag here. | |
d808f617 | 2102 | */ |
43ff2122 CH |
2103 | bp->b_flags |= _XBF_DELWRI_Q; |
2104 | if (list_empty(&bp->b_list)) { | |
2105 | atomic_inc(&bp->b_hold); | |
2106 | list_add_tail(&bp->b_list, list); | |
585e6d88 | 2107 | } |
585e6d88 | 2108 | |
43ff2122 | 2109 | return true; |
585e6d88 DC |
2110 | } |
2111 | ||
089716aa DC |
2112 | /* |
2113 | * Compare function is more complex than it needs to be because | |
2114 | * the return value is only 32 bits and we are doing comparisons | |
2115 | * on 64 bit values | |
2116 | */ | |
2117 | static int | |
2118 | xfs_buf_cmp( | |
4f0f586b ST |
2119 | void *priv, |
2120 | const struct list_head *a, | |
2121 | const struct list_head *b) | |
089716aa DC |
2122 | { |
2123 | struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list); | |
2124 | struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); | |
2125 | xfs_daddr_t diff; | |
2126 | ||
f4b42421 | 2127 | diff = ap->b_maps[0].bm_bn - bp->b_maps[0].bm_bn; |
089716aa DC |
2128 | if (diff < 0) |
2129 | return -1; | |
2130 | if (diff > 0) | |
2131 | return 1; | |
2132 | return 0; | |
2133 | } | |
2134 | ||
26f1fe85 | 2135 | /* |
e339dd8d BF |
2136 | * Submit buffers for write. If wait_list is specified, the buffers are |
2137 | * submitted using sync I/O and placed on the wait list such that the caller can | |
2138 | * iowait each buffer. Otherwise async I/O is used and the buffers are released | |
2139 | * at I/O completion time. In either case, buffers remain locked until I/O | |
2140 | * completes and the buffer is released from the queue. | |
26f1fe85 | 2141 | */ |
43ff2122 | 2142 | static int |
26f1fe85 | 2143 | xfs_buf_delwri_submit_buffers( |
43ff2122 | 2144 | struct list_head *buffer_list, |
26f1fe85 | 2145 | struct list_head *wait_list) |
1da177e4 | 2146 | { |
43ff2122 CH |
2147 | struct xfs_buf *bp, *n; |
2148 | int pinned = 0; | |
26f1fe85 | 2149 | struct blk_plug plug; |
43ff2122 | 2150 | |
26f1fe85 | 2151 | list_sort(NULL, buffer_list, xfs_buf_cmp); |
43ff2122 | 2152 | |
26f1fe85 | 2153 | blk_start_plug(&plug); |
43ff2122 | 2154 | list_for_each_entry_safe(bp, n, buffer_list, b_list) { |
26f1fe85 | 2155 | if (!wait_list) { |
dbd0f529 DC |
2156 | if (!xfs_buf_trylock(bp)) |
2157 | continue; | |
43ff2122 | 2158 | if (xfs_buf_ispinned(bp)) { |
dbd0f529 | 2159 | xfs_buf_unlock(bp); |
43ff2122 CH |
2160 | pinned++; |
2161 | continue; | |
2162 | } | |
43ff2122 CH |
2163 | } else { |
2164 | xfs_buf_lock(bp); | |
2165 | } | |
978c7b2f | 2166 | |
43ff2122 CH |
2167 | /* |
2168 | * Someone else might have written the buffer synchronously or | |
2169 | * marked it stale in the meantime. In that case only the | |
2170 | * _XBF_DELWRI_Q flag got cleared, and we have to drop the | |
2171 | * reference and remove it from the list here. | |
2172 | */ | |
2173 | if (!(bp->b_flags & _XBF_DELWRI_Q)) { | |
2174 | list_del_init(&bp->b_list); | |
2175 | xfs_buf_relse(bp); | |
2176 | continue; | |
2177 | } | |
c9c12971 | 2178 | |
43ff2122 | 2179 | trace_xfs_buf_delwri_split(bp, _RET_IP_); |
a1b7ea5d | 2180 | |
cf53e99d | 2181 | /* |
e339dd8d BF |
2182 | * If we have a wait list, each buffer (and associated delwri |
2183 | * queue reference) transfers to it and is submitted | |
2184 | * synchronously. Otherwise, drop the buffer from the delwri | |
2185 | * queue and submit async. | |
cf53e99d | 2186 | */ |
b6983e80 | 2187 | bp->b_flags &= ~_XBF_DELWRI_Q; |
e339dd8d | 2188 | bp->b_flags |= XBF_WRITE; |
26f1fe85 | 2189 | if (wait_list) { |
e339dd8d | 2190 | bp->b_flags &= ~XBF_ASYNC; |
26f1fe85 | 2191 | list_move_tail(&bp->b_list, wait_list); |
e339dd8d BF |
2192 | } else { |
2193 | bp->b_flags |= XBF_ASYNC; | |
ce8e922c | 2194 | list_del_init(&bp->b_list); |
e339dd8d | 2195 | } |
6af88cda | 2196 | __xfs_buf_submit(bp, false); |
43ff2122 CH |
2197 | } |
2198 | blk_finish_plug(&plug); | |
1da177e4 | 2199 | |
43ff2122 | 2200 | return pinned; |
1da177e4 LT |
2201 | } |
2202 | ||
2203 | /* | |
43ff2122 CH |
2204 | * Write out a buffer list asynchronously. |
2205 | * | |
2206 | * This will take the @buffer_list, write all non-locked and non-pinned buffers | |
2207 | * out and not wait for I/O completion on any of the buffers. This interface | |
2208 | * is only safely useable for callers that can track I/O completion by higher | |
2209 | * level means, e.g. AIL pushing as the @buffer_list is consumed in this | |
2210 | * function. | |
efc3289c BF |
2211 | * |
2212 | * Note: this function will skip buffers it would block on, and in doing so | |
2213 | * leaves them on @buffer_list so they can be retried on a later pass. As such, | |
2214 | * it is up to the caller to ensure that the buffer list is fully submitted or | |
2215 | * cancelled appropriately when they are finished with the list. Failure to | |
2216 | * cancel or resubmit the list until it is empty will result in leaked buffers | |
2217 | * at unmount time. | |
1da177e4 LT |
2218 | */ |
2219 | int | |
43ff2122 CH |
2220 | xfs_buf_delwri_submit_nowait( |
2221 | struct list_head *buffer_list) | |
1da177e4 | 2222 | { |
26f1fe85 | 2223 | return xfs_buf_delwri_submit_buffers(buffer_list, NULL); |
43ff2122 | 2224 | } |
1da177e4 | 2225 | |
43ff2122 CH |
2226 | /* |
2227 | * Write out a buffer list synchronously. | |
2228 | * | |
2229 | * This will take the @buffer_list, write all buffers out and wait for I/O | |
2230 | * completion on all of the buffers. @buffer_list is consumed by the function, | |
2231 | * so callers must have some other way of tracking buffers if they require such | |
2232 | * functionality. | |
2233 | */ | |
2234 | int | |
2235 | xfs_buf_delwri_submit( | |
2236 | struct list_head *buffer_list) | |
2237 | { | |
26f1fe85 | 2238 | LIST_HEAD (wait_list); |
43ff2122 CH |
2239 | int error = 0, error2; |
2240 | struct xfs_buf *bp; | |
1da177e4 | 2241 | |
26f1fe85 | 2242 | xfs_buf_delwri_submit_buffers(buffer_list, &wait_list); |
1da177e4 | 2243 | |
43ff2122 | 2244 | /* Wait for IO to complete. */ |
26f1fe85 DC |
2245 | while (!list_empty(&wait_list)) { |
2246 | bp = list_first_entry(&wait_list, struct xfs_buf, b_list); | |
a1b7ea5d | 2247 | |
089716aa | 2248 | list_del_init(&bp->b_list); |
cf53e99d | 2249 | |
e339dd8d BF |
2250 | /* |
2251 | * Wait on the locked buffer, check for errors and unlock and | |
2252 | * release the delwri queue reference. | |
2253 | */ | |
2254 | error2 = xfs_buf_iowait(bp); | |
43ff2122 CH |
2255 | xfs_buf_relse(bp); |
2256 | if (!error) | |
2257 | error = error2; | |
1da177e4 LT |
2258 | } |
2259 | ||
43ff2122 | 2260 | return error; |
1da177e4 LT |
2261 | } |
2262 | ||
7912e7fe BF |
2263 | /* |
2264 | * Push a single buffer on a delwri queue. | |
2265 | * | |
2266 | * The purpose of this function is to submit a single buffer of a delwri queue | |
2267 | * and return with the buffer still on the original queue. The waiting delwri | |
2268 | * buffer submission infrastructure guarantees transfer of the delwri queue | |
2269 | * buffer reference to a temporary wait list. We reuse this infrastructure to | |
2270 | * transfer the buffer back to the original queue. | |
2271 | * | |
2272 | * Note the buffer transitions from the queued state, to the submitted and wait | |
2273 | * listed state and back to the queued state during this call. The buffer | |
2274 | * locking and queue management logic between _delwri_pushbuf() and | |
2275 | * _delwri_queue() guarantee that the buffer cannot be queued to another list | |
2276 | * before returning. | |
2277 | */ | |
2278 | int | |
2279 | xfs_buf_delwri_pushbuf( | |
2280 | struct xfs_buf *bp, | |
2281 | struct list_head *buffer_list) | |
2282 | { | |
2283 | LIST_HEAD (submit_list); | |
2284 | int error; | |
2285 | ||
2286 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
2287 | ||
2288 | trace_xfs_buf_delwri_pushbuf(bp, _RET_IP_); | |
2289 | ||
2290 | /* | |
2291 | * Isolate the buffer to a new local list so we can submit it for I/O | |
2292 | * independently from the rest of the original list. | |
2293 | */ | |
2294 | xfs_buf_lock(bp); | |
2295 | list_move(&bp->b_list, &submit_list); | |
2296 | xfs_buf_unlock(bp); | |
2297 | ||
2298 | /* | |
2299 | * Delwri submission clears the DELWRI_Q buffer flag and returns with | |
e339dd8d | 2300 | * the buffer on the wait list with the original reference. Rather than |
7912e7fe BF |
2301 | * bounce the buffer from a local wait list back to the original list |
2302 | * after I/O completion, reuse the original list as the wait list. | |
2303 | */ | |
2304 | xfs_buf_delwri_submit_buffers(&submit_list, buffer_list); | |
2305 | ||
2306 | /* | |
e339dd8d BF |
2307 | * The buffer is now locked, under I/O and wait listed on the original |
2308 | * delwri queue. Wait for I/O completion, restore the DELWRI_Q flag and | |
2309 | * return with the buffer unlocked and on the original queue. | |
7912e7fe | 2310 | */ |
e339dd8d | 2311 | error = xfs_buf_iowait(bp); |
7912e7fe BF |
2312 | bp->b_flags |= _XBF_DELWRI_Q; |
2313 | xfs_buf_unlock(bp); | |
2314 | ||
2315 | return error; | |
2316 | } | |
2317 | ||
7561d27e BF |
2318 | void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref) |
2319 | { | |
7561d27e BF |
2320 | /* |
2321 | * Set the lru reference count to 0 based on the error injection tag. | |
2322 | * This allows userspace to disrupt buffer caching for debug/testing | |
2323 | * purposes. | |
2324 | */ | |
dbd329f1 | 2325 | if (XFS_TEST_ERROR(false, bp->b_mount, XFS_ERRTAG_BUF_LRU_REF)) |
7561d27e BF |
2326 | lru_ref = 0; |
2327 | ||
2328 | atomic_set(&bp->b_lru_ref, lru_ref); | |
2329 | } | |
8473fee3 BF |
2330 | |
2331 | /* | |
2332 | * Verify an on-disk magic value against the magic value specified in the | |
2333 | * verifier structure. The verifier magic is in disk byte order so the caller is | |
2334 | * expected to pass the value directly from disk. | |
2335 | */ | |
2336 | bool | |
2337 | xfs_verify_magic( | |
2338 | struct xfs_buf *bp, | |
15baadf7 | 2339 | __be32 dmagic) |
8473fee3 | 2340 | { |
dbd329f1 | 2341 | struct xfs_mount *mp = bp->b_mount; |
8473fee3 BF |
2342 | int idx; |
2343 | ||
38c26bfd | 2344 | idx = xfs_has_crc(mp); |
14ed8688 | 2345 | if (WARN_ON(!bp->b_ops || !bp->b_ops->magic[idx])) |
8473fee3 BF |
2346 | return false; |
2347 | return dmagic == bp->b_ops->magic[idx]; | |
2348 | } | |
15baadf7 DW |
2349 | /* |
2350 | * Verify an on-disk magic value against the magic value specified in the | |
2351 | * verifier structure. The verifier magic is in disk byte order so the caller is | |
2352 | * expected to pass the value directly from disk. | |
2353 | */ | |
2354 | bool | |
2355 | xfs_verify_magic16( | |
2356 | struct xfs_buf *bp, | |
2357 | __be16 dmagic) | |
2358 | { | |
dbd329f1 | 2359 | struct xfs_mount *mp = bp->b_mount; |
15baadf7 DW |
2360 | int idx; |
2361 | ||
38c26bfd | 2362 | idx = xfs_has_crc(mp); |
14ed8688 | 2363 | if (WARN_ON(!bp->b_ops || !bp->b_ops->magic16[idx])) |
15baadf7 DW |
2364 | return false; |
2365 | return dmagic == bp->b_ops->magic16[idx]; | |
2366 | } |