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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" |
01728b44 | 17 | #include "xfs_log_priv.h" |
f593bf14 DC |
18 | #include "xfs_trans.h" |
19 | #include "xfs_buf_item.h" | |
e9e899a2 | 20 | #include "xfs_errortag.h" |
7561d27e | 21 | #include "xfs_error.h" |
9bbafc71 | 22 | #include "xfs_ag.h" |
b7963133 | 23 | |
182696fb | 24 | static struct kmem_cache *xfs_buf_cache; |
23ea4032 | 25 | |
37fd1678 DC |
26 | /* |
27 | * Locking orders | |
28 | * | |
29 | * xfs_buf_ioacct_inc: | |
30 | * xfs_buf_ioacct_dec: | |
31 | * b_sema (caller holds) | |
32 | * b_lock | |
33 | * | |
34 | * xfs_buf_stale: | |
35 | * b_sema (caller holds) | |
36 | * b_lock | |
37 | * lru_lock | |
38 | * | |
39 | * xfs_buf_rele: | |
40 | * b_lock | |
41 | * pag_buf_lock | |
42 | * lru_lock | |
43 | * | |
10fb9ac1 | 44 | * xfs_buftarg_drain_rele |
37fd1678 DC |
45 | * lru_lock |
46 | * b_lock (trylock due to inversion) | |
47 | * | |
48 | * xfs_buftarg_isolate | |
49 | * lru_lock | |
50 | * b_lock (trylock due to inversion) | |
51 | */ | |
1da177e4 | 52 | |
26e32875 CH |
53 | static int __xfs_buf_submit(struct xfs_buf *bp, bool wait); |
54 | ||
55 | static inline int | |
56 | xfs_buf_submit( | |
57 | struct xfs_buf *bp) | |
58 | { | |
59 | return __xfs_buf_submit(bp, !(bp->b_flags & XBF_ASYNC)); | |
60 | } | |
61 | ||
73c77e2c JB |
62 | static inline int |
63 | xfs_buf_is_vmapped( | |
64 | struct xfs_buf *bp) | |
65 | { | |
66 | /* | |
67 | * Return true if the buffer is vmapped. | |
68 | * | |
611c9946 DC |
69 | * b_addr is null if the buffer is not mapped, but the code is clever |
70 | * enough to know it doesn't have to map a single page, so the check has | |
71 | * to be both for b_addr and bp->b_page_count > 1. | |
73c77e2c | 72 | */ |
611c9946 | 73 | return bp->b_addr && bp->b_page_count > 1; |
73c77e2c JB |
74 | } |
75 | ||
76 | static inline int | |
77 | xfs_buf_vmap_len( | |
78 | struct xfs_buf *bp) | |
79 | { | |
54cd3aa6 | 80 | return (bp->b_page_count * PAGE_SIZE); |
73c77e2c JB |
81 | } |
82 | ||
9c7504aa BF |
83 | /* |
84 | * Bump the I/O in flight count on the buftarg if we haven't yet done so for | |
85 | * this buffer. The count is incremented once per buffer (per hold cycle) | |
86 | * because the corresponding decrement is deferred to buffer release. Buffers | |
87 | * can undergo I/O multiple times in a hold-release cycle and per buffer I/O | |
88 | * tracking adds unnecessary overhead. This is used for sychronization purposes | |
10fb9ac1 | 89 | * with unmount (see xfs_buftarg_drain()), so all we really need is a count of |
9c7504aa BF |
90 | * in-flight buffers. |
91 | * | |
92 | * Buffers that are never released (e.g., superblock, iclog buffers) must set | |
93 | * the XBF_NO_IOACCT flag before I/O submission. Otherwise, the buftarg count | |
94 | * never reaches zero and unmount hangs indefinitely. | |
95 | */ | |
96 | static inline void | |
97 | xfs_buf_ioacct_inc( | |
98 | struct xfs_buf *bp) | |
99 | { | |
63db7c81 | 100 | if (bp->b_flags & XBF_NO_IOACCT) |
9c7504aa BF |
101 | return; |
102 | ||
103 | ASSERT(bp->b_flags & XBF_ASYNC); | |
63db7c81 BF |
104 | spin_lock(&bp->b_lock); |
105 | if (!(bp->b_state & XFS_BSTATE_IN_FLIGHT)) { | |
106 | bp->b_state |= XFS_BSTATE_IN_FLIGHT; | |
107 | percpu_counter_inc(&bp->b_target->bt_io_count); | |
108 | } | |
109 | spin_unlock(&bp->b_lock); | |
9c7504aa BF |
110 | } |
111 | ||
112 | /* | |
113 | * Clear the in-flight state on a buffer about to be released to the LRU or | |
114 | * freed and unaccount from the buftarg. | |
115 | */ | |
116 | static inline void | |
63db7c81 | 117 | __xfs_buf_ioacct_dec( |
9c7504aa BF |
118 | struct xfs_buf *bp) |
119 | { | |
95989c46 | 120 | lockdep_assert_held(&bp->b_lock); |
9c7504aa | 121 | |
63db7c81 BF |
122 | if (bp->b_state & XFS_BSTATE_IN_FLIGHT) { |
123 | bp->b_state &= ~XFS_BSTATE_IN_FLIGHT; | |
124 | percpu_counter_dec(&bp->b_target->bt_io_count); | |
125 | } | |
126 | } | |
127 | ||
128 | static inline void | |
129 | xfs_buf_ioacct_dec( | |
130 | struct xfs_buf *bp) | |
131 | { | |
132 | spin_lock(&bp->b_lock); | |
133 | __xfs_buf_ioacct_dec(bp); | |
134 | spin_unlock(&bp->b_lock); | |
9c7504aa BF |
135 | } |
136 | ||
430cbeb8 DC |
137 | /* |
138 | * When we mark a buffer stale, we remove the buffer from the LRU and clear the | |
139 | * b_lru_ref count so that the buffer is freed immediately when the buffer | |
140 | * reference count falls to zero. If the buffer is already on the LRU, we need | |
141 | * to remove the reference that LRU holds on the buffer. | |
142 | * | |
143 | * This prevents build-up of stale buffers on the LRU. | |
144 | */ | |
145 | void | |
146 | xfs_buf_stale( | |
147 | struct xfs_buf *bp) | |
148 | { | |
43ff2122 CH |
149 | ASSERT(xfs_buf_islocked(bp)); |
150 | ||
430cbeb8 | 151 | bp->b_flags |= XBF_STALE; |
43ff2122 CH |
152 | |
153 | /* | |
154 | * Clear the delwri status so that a delwri queue walker will not | |
155 | * flush this buffer to disk now that it is stale. The delwri queue has | |
156 | * a reference to the buffer, so this is safe to do. | |
157 | */ | |
158 | bp->b_flags &= ~_XBF_DELWRI_Q; | |
159 | ||
9c7504aa BF |
160 | /* |
161 | * Once the buffer is marked stale and unlocked, a subsequent lookup | |
162 | * could reset b_flags. There is no guarantee that the buffer is | |
163 | * unaccounted (released to LRU) before that occurs. Drop in-flight | |
164 | * status now to preserve accounting consistency. | |
165 | */ | |
a4082357 | 166 | spin_lock(&bp->b_lock); |
63db7c81 BF |
167 | __xfs_buf_ioacct_dec(bp); |
168 | ||
a4082357 DC |
169 | atomic_set(&bp->b_lru_ref, 0); |
170 | if (!(bp->b_state & XFS_BSTATE_DISPOSE) && | |
e80dfa19 DC |
171 | (list_lru_del(&bp->b_target->bt_lru, &bp->b_lru))) |
172 | atomic_dec(&bp->b_hold); | |
173 | ||
430cbeb8 | 174 | ASSERT(atomic_read(&bp->b_hold) >= 1); |
a4082357 | 175 | spin_unlock(&bp->b_lock); |
430cbeb8 | 176 | } |
1da177e4 | 177 | |
3e85c868 DC |
178 | static int |
179 | xfs_buf_get_maps( | |
180 | struct xfs_buf *bp, | |
181 | int map_count) | |
182 | { | |
183 | ASSERT(bp->b_maps == NULL); | |
184 | bp->b_map_count = map_count; | |
185 | ||
186 | if (map_count == 1) { | |
f4b42421 | 187 | bp->b_maps = &bp->__b_map; |
3e85c868 DC |
188 | return 0; |
189 | } | |
190 | ||
191 | bp->b_maps = kmem_zalloc(map_count * sizeof(struct xfs_buf_map), | |
192 | KM_NOFS); | |
193 | if (!bp->b_maps) | |
2451337d | 194 | return -ENOMEM; |
3e85c868 DC |
195 | return 0; |
196 | } | |
197 | ||
198 | /* | |
199 | * Frees b_pages if it was allocated. | |
200 | */ | |
201 | static void | |
202 | xfs_buf_free_maps( | |
203 | struct xfs_buf *bp) | |
204 | { | |
f4b42421 | 205 | if (bp->b_maps != &bp->__b_map) { |
3e85c868 DC |
206 | kmem_free(bp->b_maps); |
207 | bp->b_maps = NULL; | |
208 | } | |
209 | } | |
210 | ||
32dff5e5 | 211 | static int |
3e85c868 | 212 | _xfs_buf_alloc( |
4347b9d7 | 213 | struct xfs_buftarg *target, |
3e85c868 DC |
214 | struct xfs_buf_map *map, |
215 | int nmaps, | |
32dff5e5 DW |
216 | xfs_buf_flags_t flags, |
217 | struct xfs_buf **bpp) | |
1da177e4 | 218 | { |
4347b9d7 | 219 | struct xfs_buf *bp; |
3e85c868 DC |
220 | int error; |
221 | int i; | |
4347b9d7 | 222 | |
32dff5e5 | 223 | *bpp = NULL; |
182696fb | 224 | bp = kmem_cache_zalloc(xfs_buf_cache, GFP_NOFS | __GFP_NOFAIL); |
4347b9d7 | 225 | |
1da177e4 | 226 | /* |
12bcb3f7 DC |
227 | * We don't want certain flags to appear in b_flags unless they are |
228 | * specifically set by later operations on the buffer. | |
1da177e4 | 229 | */ |
611c9946 | 230 | flags &= ~(XBF_UNMAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD); |
ce8e922c | 231 | |
ce8e922c | 232 | atomic_set(&bp->b_hold, 1); |
430cbeb8 | 233 | atomic_set(&bp->b_lru_ref, 1); |
b4dd330b | 234 | init_completion(&bp->b_iowait); |
430cbeb8 | 235 | INIT_LIST_HEAD(&bp->b_lru); |
ce8e922c | 236 | INIT_LIST_HEAD(&bp->b_list); |
643c8c05 | 237 | INIT_LIST_HEAD(&bp->b_li_list); |
a731cd11 | 238 | sema_init(&bp->b_sema, 0); /* held, no waiters */ |
a4082357 | 239 | spin_lock_init(&bp->b_lock); |
ce8e922c | 240 | bp->b_target = target; |
dbd329f1 | 241 | bp->b_mount = target->bt_mount; |
3e85c868 | 242 | bp->b_flags = flags; |
de1cbee4 | 243 | |
1da177e4 | 244 | /* |
aa0e8833 DC |
245 | * Set length and io_length to the same value initially. |
246 | * I/O routines should use io_length, which will be the same in | |
1da177e4 LT |
247 | * most cases but may be reset (e.g. XFS recovery). |
248 | */ | |
3e85c868 DC |
249 | error = xfs_buf_get_maps(bp, nmaps); |
250 | if (error) { | |
182696fb | 251 | kmem_cache_free(xfs_buf_cache, bp); |
32dff5e5 | 252 | return error; |
3e85c868 DC |
253 | } |
254 | ||
4c7f65ae | 255 | bp->b_rhash_key = map[0].bm_bn; |
3e85c868 DC |
256 | bp->b_length = 0; |
257 | for (i = 0; i < nmaps; i++) { | |
258 | bp->b_maps[i].bm_bn = map[i].bm_bn; | |
259 | bp->b_maps[i].bm_len = map[i].bm_len; | |
260 | bp->b_length += map[i].bm_len; | |
261 | } | |
3e85c868 | 262 | |
ce8e922c NS |
263 | atomic_set(&bp->b_pin_count, 0); |
264 | init_waitqueue_head(&bp->b_waiters); | |
265 | ||
dbd329f1 | 266 | XFS_STATS_INC(bp->b_mount, xb_create); |
0b1b213f | 267 | trace_xfs_buf_init(bp, _RET_IP_); |
4347b9d7 | 268 | |
32dff5e5 DW |
269 | *bpp = bp; |
270 | return 0; | |
1da177e4 LT |
271 | } |
272 | ||
e7d236a6 DC |
273 | static void |
274 | xfs_buf_free_pages( | |
e8222613 | 275 | struct xfs_buf *bp) |
1da177e4 | 276 | { |
e7d236a6 DC |
277 | uint i; |
278 | ||
279 | ASSERT(bp->b_flags & _XBF_PAGES); | |
280 | ||
281 | if (xfs_buf_is_vmapped(bp)) | |
54cd3aa6 | 282 | vm_unmap_ram(bp->b_addr, bp->b_page_count); |
e7d236a6 DC |
283 | |
284 | for (i = 0; i < bp->b_page_count; i++) { | |
285 | if (bp->b_pages[i]) | |
286 | __free_page(bp->b_pages[i]); | |
287 | } | |
288 | if (current->reclaim_state) | |
289 | current->reclaim_state->reclaimed_slab += bp->b_page_count; | |
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 | ||
25a40957 | 297 | static void |
ce8e922c | 298 | xfs_buf_free( |
e8222613 | 299 | struct xfs_buf *bp) |
1da177e4 | 300 | { |
0b1b213f | 301 | trace_xfs_buf_free(bp, _RET_IP_); |
1da177e4 | 302 | |
430cbeb8 DC |
303 | ASSERT(list_empty(&bp->b_lru)); |
304 | ||
e7d236a6 DC |
305 | if (bp->b_flags & _XBF_PAGES) |
306 | xfs_buf_free_pages(bp); | |
307 | else if (bp->b_flags & _XBF_KMEM) | |
0e6e847f | 308 | kmem_free(bp->b_addr); |
e7d236a6 | 309 | |
3e85c868 | 310 | xfs_buf_free_maps(bp); |
182696fb | 311 | kmem_cache_free(xfs_buf_cache, bp); |
1da177e4 LT |
312 | } |
313 | ||
0a683794 DC |
314 | static int |
315 | xfs_buf_alloc_kmem( | |
316 | struct xfs_buf *bp, | |
0a683794 | 317 | xfs_buf_flags_t flags) |
1da177e4 | 318 | { |
0a683794 | 319 | xfs_km_flags_t kmflag_mask = KM_NOFS; |
8bcac744 | 320 | size_t size = BBTOB(bp->b_length); |
3219e8cf | 321 | |
0a683794 DC |
322 | /* Assure zeroed buffer for non-read cases. */ |
323 | if (!(flags & XBF_READ)) | |
3219e8cf | 324 | kmflag_mask |= KM_ZERO; |
1da177e4 | 325 | |
98fe2c3c | 326 | bp->b_addr = kmem_alloc(size, kmflag_mask); |
0a683794 DC |
327 | if (!bp->b_addr) |
328 | return -ENOMEM; | |
0e6e847f | 329 | |
0a683794 DC |
330 | if (((unsigned long)(bp->b_addr + size - 1) & PAGE_MASK) != |
331 | ((unsigned long)bp->b_addr & PAGE_MASK)) { | |
332 | /* b_addr spans two pages - use alloc_page instead */ | |
333 | kmem_free(bp->b_addr); | |
334 | bp->b_addr = NULL; | |
335 | return -ENOMEM; | |
0e6e847f | 336 | } |
0a683794 DC |
337 | bp->b_offset = offset_in_page(bp->b_addr); |
338 | bp->b_pages = bp->b_page_array; | |
339 | bp->b_pages[0] = kmem_to_page(bp->b_addr); | |
340 | bp->b_page_count = 1; | |
341 | bp->b_flags |= _XBF_KMEM; | |
342 | return 0; | |
343 | } | |
344 | ||
345 | static int | |
346 | xfs_buf_alloc_pages( | |
347 | struct xfs_buf *bp, | |
0a683794 DC |
348 | xfs_buf_flags_t flags) |
349 | { | |
289ae7b4 | 350 | gfp_t gfp_mask = __GFP_NOWARN; |
c9fa5630 | 351 | long filled = 0; |
0a683794 | 352 | |
289ae7b4 DC |
353 | if (flags & XBF_READ_AHEAD) |
354 | gfp_mask |= __GFP_NORETRY; | |
355 | else | |
356 | gfp_mask |= GFP_NOFS; | |
357 | ||
02c51173 | 358 | /* Make sure that we have a page list */ |
934d1076 | 359 | bp->b_page_count = DIV_ROUND_UP(BBTOB(bp->b_length), PAGE_SIZE); |
02c51173 DC |
360 | if (bp->b_page_count <= XB_PAGES) { |
361 | bp->b_pages = bp->b_page_array; | |
362 | } else { | |
363 | bp->b_pages = kzalloc(sizeof(struct page *) * bp->b_page_count, | |
364 | gfp_mask); | |
365 | if (!bp->b_pages) | |
366 | return -ENOMEM; | |
367 | } | |
368 | bp->b_flags |= _XBF_PAGES; | |
369 | ||
0a683794 DC |
370 | /* Assure zeroed buffer for non-read cases. */ |
371 | if (!(flags & XBF_READ)) | |
372 | gfp_mask |= __GFP_ZERO; | |
0e6e847f | 373 | |
c9fa5630 DC |
374 | /* |
375 | * Bulk filling of pages can take multiple calls. Not filling the entire | |
376 | * array is not an allocation failure, so don't back off if we get at | |
377 | * least one extra page. | |
378 | */ | |
379 | for (;;) { | |
380 | long last = filled; | |
381 | ||
382 | filled = alloc_pages_bulk_array(gfp_mask, bp->b_page_count, | |
383 | bp->b_pages); | |
384 | if (filled == bp->b_page_count) { | |
385 | XFS_STATS_INC(bp->b_mount, xb_page_found); | |
386 | break; | |
1da177e4 LT |
387 | } |
388 | ||
c9fa5630 DC |
389 | if (filled != last) |
390 | continue; | |
391 | ||
392 | if (flags & XBF_READ_AHEAD) { | |
e7d236a6 DC |
393 | xfs_buf_free_pages(bp); |
394 | return -ENOMEM; | |
c9fa5630 | 395 | } |
1da177e4 | 396 | |
c9fa5630 | 397 | XFS_STATS_INC(bp->b_mount, xb_page_retries); |
4034247a | 398 | memalloc_retry_wait(gfp_mask); |
1da177e4 | 399 | } |
0e6e847f | 400 | return 0; |
1da177e4 LT |
401 | } |
402 | ||
403 | /* | |
25985edc | 404 | * Map buffer into kernel address-space if necessary. |
1da177e4 LT |
405 | */ |
406 | STATIC int | |
ce8e922c | 407 | _xfs_buf_map_pages( |
e8222613 | 408 | struct xfs_buf *bp, |
b9b3fe15 | 409 | xfs_buf_flags_t flags) |
1da177e4 | 410 | { |
0e6e847f | 411 | ASSERT(bp->b_flags & _XBF_PAGES); |
ce8e922c | 412 | if (bp->b_page_count == 1) { |
0e6e847f | 413 | /* A single page buffer is always mappable */ |
54cd3aa6 | 414 | bp->b_addr = page_address(bp->b_pages[0]); |
611c9946 DC |
415 | } else if (flags & XBF_UNMAPPED) { |
416 | bp->b_addr = NULL; | |
417 | } else { | |
a19fb380 | 418 | int retried = 0; |
9ba1fb2c | 419 | unsigned nofs_flag; |
ae687e58 DC |
420 | |
421 | /* | |
cf085a1b | 422 | * vm_map_ram() will allocate auxiliary structures (e.g. |
ae687e58 DC |
423 | * pagetables) with GFP_KERNEL, yet we are likely to be under |
424 | * GFP_NOFS context here. Hence we need to tell memory reclaim | |
9ba1fb2c | 425 | * that we are in such a context via PF_MEMALLOC_NOFS to prevent |
ae687e58 DC |
426 | * memory reclaim re-entering the filesystem here and |
427 | * potentially deadlocking. | |
428 | */ | |
9ba1fb2c | 429 | nofs_flag = memalloc_nofs_save(); |
a19fb380 DC |
430 | do { |
431 | bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, | |
d4efd79a | 432 | -1); |
a19fb380 DC |
433 | if (bp->b_addr) |
434 | break; | |
435 | vm_unmap_aliases(); | |
436 | } while (retried++ <= 1); | |
9ba1fb2c | 437 | memalloc_nofs_restore(nofs_flag); |
a19fb380 DC |
438 | |
439 | if (!bp->b_addr) | |
1da177e4 | 440 | return -ENOMEM; |
1da177e4 LT |
441 | } |
442 | ||
443 | return 0; | |
444 | } | |
445 | ||
446 | /* | |
447 | * Finding and Reading Buffers | |
448 | */ | |
6031e73a LS |
449 | static int |
450 | _xfs_buf_obj_cmp( | |
451 | struct rhashtable_compare_arg *arg, | |
452 | const void *obj) | |
453 | { | |
454 | const struct xfs_buf_map *map = arg->key; | |
455 | const struct xfs_buf *bp = obj; | |
456 | ||
457 | /* | |
458 | * The key hashing in the lookup path depends on the key being the | |
459 | * first element of the compare_arg, make sure to assert this. | |
460 | */ | |
461 | BUILD_BUG_ON(offsetof(struct xfs_buf_map, bm_bn) != 0); | |
462 | ||
4c7f65ae | 463 | if (bp->b_rhash_key != map->bm_bn) |
6031e73a LS |
464 | return 1; |
465 | ||
466 | if (unlikely(bp->b_length != map->bm_len)) { | |
467 | /* | |
468 | * found a block number match. If the range doesn't | |
469 | * match, the only way this is allowed is if the buffer | |
470 | * in the cache is stale and the transaction that made | |
471 | * it stale has not yet committed. i.e. we are | |
472 | * reallocating a busy extent. Skip this buffer and | |
473 | * continue searching for an exact match. | |
474 | */ | |
475 | ASSERT(bp->b_flags & XBF_STALE); | |
476 | return 1; | |
477 | } | |
478 | return 0; | |
479 | } | |
480 | ||
481 | static const struct rhashtable_params xfs_buf_hash_params = { | |
482 | .min_size = 32, /* empty AGs have minimal footprint */ | |
483 | .nelem_hint = 16, | |
484 | .key_len = sizeof(xfs_daddr_t), | |
4c7f65ae | 485 | .key_offset = offsetof(struct xfs_buf, b_rhash_key), |
6031e73a LS |
486 | .head_offset = offsetof(struct xfs_buf, b_rhash_head), |
487 | .automatic_shrinking = true, | |
488 | .obj_cmpfn = _xfs_buf_obj_cmp, | |
489 | }; | |
490 | ||
491 | int | |
492 | xfs_buf_hash_init( | |
493 | struct xfs_perag *pag) | |
494 | { | |
495 | spin_lock_init(&pag->pag_buf_lock); | |
496 | return rhashtable_init(&pag->pag_buf_hash, &xfs_buf_hash_params); | |
497 | } | |
498 | ||
499 | void | |
500 | xfs_buf_hash_destroy( | |
501 | struct xfs_perag *pag) | |
502 | { | |
503 | rhashtable_destroy(&pag->pag_buf_hash); | |
504 | } | |
1da177e4 LT |
505 | |
506 | /* | |
b027d4c9 DC |
507 | * Look up a buffer in the buffer cache and return it referenced and locked |
508 | * in @found_bp. | |
509 | * | |
510 | * If @new_bp is supplied and we have a lookup miss, insert @new_bp into the | |
511 | * cache. | |
512 | * | |
513 | * If XBF_TRYLOCK is set in @flags, only try to lock the buffer and return | |
514 | * -EAGAIN if we fail to lock it. | |
515 | * | |
516 | * Return values are: | |
517 | * -EFSCORRUPTED if have been supplied with an invalid address | |
518 | * -EAGAIN on trylock failure | |
519 | * -ENOENT if we fail to find a match and @new_bp was NULL | |
520 | * 0, with @found_bp: | |
521 | * - @new_bp if we inserted it into the cache | |
522 | * - the buffer we found and locked. | |
1da177e4 | 523 | */ |
b027d4c9 DC |
524 | static int |
525 | xfs_buf_find( | |
e70b73f8 | 526 | struct xfs_buftarg *btp, |
3e85c868 DC |
527 | struct xfs_buf_map *map, |
528 | int nmaps, | |
ce8e922c | 529 | xfs_buf_flags_t flags, |
b027d4c9 DC |
530 | struct xfs_buf *new_bp, |
531 | struct xfs_buf **found_bp) | |
1da177e4 | 532 | { |
74f75a0c | 533 | struct xfs_perag *pag; |
e8222613 | 534 | struct xfs_buf *bp; |
6031e73a | 535 | struct xfs_buf_map cmap = { .bm_bn = map[0].bm_bn }; |
10616b80 | 536 | xfs_daddr_t eofs; |
3e85c868 | 537 | int i; |
1da177e4 | 538 | |
b027d4c9 DC |
539 | *found_bp = NULL; |
540 | ||
3e85c868 | 541 | for (i = 0; i < nmaps; i++) |
6031e73a | 542 | cmap.bm_len += map[i].bm_len; |
1da177e4 LT |
543 | |
544 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
6031e73a LS |
545 | ASSERT(!(BBTOB(cmap.bm_len) < btp->bt_meta_sectorsize)); |
546 | ASSERT(!(BBTOB(cmap.bm_bn) & (xfs_off_t)btp->bt_meta_sectormask)); | |
1da177e4 | 547 | |
10616b80 DC |
548 | /* |
549 | * Corrupted block numbers can get through to here, unfortunately, so we | |
550 | * have to check that the buffer falls within the filesystem bounds. | |
551 | */ | |
552 | eofs = XFS_FSB_TO_BB(btp->bt_mount, btp->bt_mount->m_sb.sb_dblocks); | |
6031e73a | 553 | if (cmap.bm_bn < 0 || cmap.bm_bn >= eofs) { |
10616b80 | 554 | xfs_alert(btp->bt_mount, |
c219b015 | 555 | "%s: daddr 0x%llx out of range, EOFS 0x%llx", |
6031e73a | 556 | __func__, cmap.bm_bn, eofs); |
7bc0dc27 | 557 | WARN_ON(1); |
b027d4c9 | 558 | return -EFSCORRUPTED; |
10616b80 DC |
559 | } |
560 | ||
74f75a0c | 561 | pag = xfs_perag_get(btp->bt_mount, |
6031e73a | 562 | xfs_daddr_to_agno(btp->bt_mount, cmap.bm_bn)); |
74f75a0c | 563 | |
74f75a0c | 564 | spin_lock(&pag->pag_buf_lock); |
6031e73a LS |
565 | bp = rhashtable_lookup_fast(&pag->pag_buf_hash, &cmap, |
566 | xfs_buf_hash_params); | |
567 | if (bp) { | |
568 | atomic_inc(&bp->b_hold); | |
569 | goto found; | |
1da177e4 LT |
570 | } |
571 | ||
572 | /* No match found */ | |
b027d4c9 | 573 | if (!new_bp) { |
ff6d6af2 | 574 | XFS_STATS_INC(btp->bt_mount, xb_miss_locked); |
74f75a0c DC |
575 | spin_unlock(&pag->pag_buf_lock); |
576 | xfs_perag_put(pag); | |
b027d4c9 | 577 | return -ENOENT; |
1da177e4 | 578 | } |
b027d4c9 DC |
579 | |
580 | /* the buffer keeps the perag reference until it is freed */ | |
581 | new_bp->b_pag = pag; | |
582 | rhashtable_insert_fast(&pag->pag_buf_hash, &new_bp->b_rhash_head, | |
583 | xfs_buf_hash_params); | |
584 | spin_unlock(&pag->pag_buf_lock); | |
585 | *found_bp = new_bp; | |
586 | return 0; | |
1da177e4 LT |
587 | |
588 | found: | |
74f75a0c DC |
589 | spin_unlock(&pag->pag_buf_lock); |
590 | xfs_perag_put(pag); | |
1da177e4 | 591 | |
0c842ad4 CH |
592 | if (!xfs_buf_trylock(bp)) { |
593 | if (flags & XBF_TRYLOCK) { | |
ce8e922c | 594 | xfs_buf_rele(bp); |
ff6d6af2 | 595 | XFS_STATS_INC(btp->bt_mount, xb_busy_locked); |
b027d4c9 | 596 | return -EAGAIN; |
1da177e4 | 597 | } |
0c842ad4 | 598 | xfs_buf_lock(bp); |
ff6d6af2 | 599 | XFS_STATS_INC(btp->bt_mount, xb_get_locked_waited); |
1da177e4 LT |
600 | } |
601 | ||
0e6e847f DC |
602 | /* |
603 | * if the buffer is stale, clear all the external state associated with | |
604 | * it. We need to keep flags such as how we allocated the buffer memory | |
605 | * intact here. | |
606 | */ | |
ce8e922c NS |
607 | if (bp->b_flags & XBF_STALE) { |
608 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
611c9946 | 609 | bp->b_flags &= _XBF_KMEM | _XBF_PAGES; |
1813dd64 | 610 | bp->b_ops = NULL; |
2f926587 | 611 | } |
0b1b213f CH |
612 | |
613 | trace_xfs_buf_find(bp, flags, _RET_IP_); | |
ff6d6af2 | 614 | XFS_STATS_INC(btp->bt_mount, xb_get_locked); |
b027d4c9 DC |
615 | *found_bp = bp; |
616 | return 0; | |
1da177e4 LT |
617 | } |
618 | ||
8925a3dc DC |
619 | struct xfs_buf * |
620 | xfs_buf_incore( | |
621 | struct xfs_buftarg *target, | |
622 | xfs_daddr_t blkno, | |
623 | size_t numblks, | |
624 | xfs_buf_flags_t flags) | |
625 | { | |
b027d4c9 DC |
626 | struct xfs_buf *bp; |
627 | int error; | |
8925a3dc | 628 | DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); |
b027d4c9 DC |
629 | |
630 | error = xfs_buf_find(target, &map, 1, flags, NULL, &bp); | |
631 | if (error) | |
632 | return NULL; | |
633 | return bp; | |
8925a3dc DC |
634 | } |
635 | ||
1da177e4 | 636 | /* |
3815832a DC |
637 | * Assembles a buffer covering the specified range. The code is optimised for |
638 | * cache hits, as metadata intensive workloads will see 3 orders of magnitude | |
639 | * more hits than misses. | |
1da177e4 | 640 | */ |
3848b5f6 | 641 | int |
6dde2707 DC |
642 | xfs_buf_get_map( |
643 | struct xfs_buftarg *target, | |
644 | struct xfs_buf_map *map, | |
645 | int nmaps, | |
3848b5f6 DW |
646 | xfs_buf_flags_t flags, |
647 | struct xfs_buf **bpp) | |
1da177e4 | 648 | { |
3815832a DC |
649 | struct xfs_buf *bp; |
650 | struct xfs_buf *new_bp; | |
9bb38aa0 | 651 | int error; |
1da177e4 | 652 | |
3848b5f6 | 653 | *bpp = NULL; |
b027d4c9 | 654 | error = xfs_buf_find(target, map, nmaps, flags, NULL, &bp); |
3848b5f6 | 655 | if (!error) |
3815832a | 656 | goto found; |
3848b5f6 DW |
657 | if (error != -ENOENT) |
658 | return error; | |
3815832a | 659 | |
32dff5e5 DW |
660 | error = _xfs_buf_alloc(target, map, nmaps, flags, &new_bp); |
661 | if (error) | |
3848b5f6 | 662 | return error; |
1da177e4 | 663 | |
8bcac744 DC |
664 | /* |
665 | * For buffers that fit entirely within a single page, first attempt to | |
666 | * allocate the memory from the heap to minimise memory usage. If we | |
667 | * can't get heap memory for these small buffers, we fall back to using | |
668 | * the page allocator. | |
669 | */ | |
670 | if (BBTOB(new_bp->b_length) >= PAGE_SIZE || | |
671 | xfs_buf_alloc_kmem(new_bp, flags) < 0) { | |
672 | error = xfs_buf_alloc_pages(new_bp, flags); | |
673 | if (error) | |
674 | goto out_free_buf; | |
675 | } | |
fe2429b0 | 676 | |
b027d4c9 | 677 | error = xfs_buf_find(target, map, nmaps, flags, new_bp, &bp); |
170041f7 CH |
678 | if (error) |
679 | goto out_free_buf; | |
3815832a | 680 | |
fe2429b0 DC |
681 | if (bp != new_bp) |
682 | xfs_buf_free(new_bp); | |
1da177e4 | 683 | |
3815832a | 684 | found: |
611c9946 | 685 | if (!bp->b_addr) { |
ce8e922c | 686 | error = _xfs_buf_map_pages(bp, flags); |
1da177e4 | 687 | if (unlikely(error)) { |
93baa55a DW |
688 | xfs_warn_ratelimited(target->bt_mount, |
689 | "%s: failed to map %u pages", __func__, | |
690 | bp->b_page_count); | |
a8acad70 | 691 | xfs_buf_relse(bp); |
3848b5f6 | 692 | return error; |
1da177e4 LT |
693 | } |
694 | } | |
695 | ||
b79f4a1c DC |
696 | /* |
697 | * Clear b_error if this is a lookup from a caller that doesn't expect | |
698 | * valid data to be found in the buffer. | |
699 | */ | |
700 | if (!(flags & XBF_READ)) | |
701 | xfs_buf_ioerror(bp, 0); | |
702 | ||
ff6d6af2 | 703 | XFS_STATS_INC(target->bt_mount, xb_get); |
0b1b213f | 704 | trace_xfs_buf_get(bp, flags, _RET_IP_); |
3848b5f6 DW |
705 | *bpp = bp; |
706 | return 0; | |
170041f7 CH |
707 | out_free_buf: |
708 | xfs_buf_free(new_bp); | |
709 | return error; | |
1da177e4 LT |
710 | } |
711 | ||
26e32875 | 712 | int |
5d765b97 | 713 | _xfs_buf_read( |
e8222613 | 714 | struct xfs_buf *bp, |
5d765b97 CH |
715 | xfs_buf_flags_t flags) |
716 | { | |
43ff2122 | 717 | ASSERT(!(flags & XBF_WRITE)); |
f4b42421 | 718 | ASSERT(bp->b_maps[0].bm_bn != XFS_BUF_DADDR_NULL); |
5d765b97 | 719 | |
26e32875 | 720 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD | XBF_DONE); |
1d5ae5df | 721 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD); |
5d765b97 | 722 | |
6af88cda | 723 | return xfs_buf_submit(bp); |
5d765b97 CH |
724 | } |
725 | ||
1aff5696 | 726 | /* |
75d02303 | 727 | * Reverify a buffer found in cache without an attached ->b_ops. |
add46b3b | 728 | * |
75d02303 BF |
729 | * If the caller passed an ops structure and the buffer doesn't have ops |
730 | * assigned, set the ops and use it to verify the contents. If verification | |
731 | * fails, clear XBF_DONE. We assume the buffer has no recorded errors and is | |
732 | * already in XBF_DONE state on entry. | |
add46b3b | 733 | * |
75d02303 BF |
734 | * Under normal operations, every in-core buffer is verified on read I/O |
735 | * completion. There are two scenarios that can lead to in-core buffers without | |
736 | * an assigned ->b_ops. The first is during log recovery of buffers on a V4 | |
737 | * filesystem, though these buffers are purged at the end of recovery. The | |
738 | * other is online repair, which intentionally reads with a NULL buffer ops to | |
739 | * run several verifiers across an in-core buffer in order to establish buffer | |
740 | * type. If repair can't establish that, the buffer will be left in memory | |
741 | * with NULL buffer ops. | |
1aff5696 DW |
742 | */ |
743 | int | |
75d02303 | 744 | xfs_buf_reverify( |
1aff5696 DW |
745 | struct xfs_buf *bp, |
746 | const struct xfs_buf_ops *ops) | |
747 | { | |
748 | ASSERT(bp->b_flags & XBF_DONE); | |
749 | ASSERT(bp->b_error == 0); | |
750 | ||
751 | if (!ops || bp->b_ops) | |
752 | return 0; | |
753 | ||
754 | bp->b_ops = ops; | |
755 | bp->b_ops->verify_read(bp); | |
756 | if (bp->b_error) | |
757 | bp->b_flags &= ~XBF_DONE; | |
758 | return bp->b_error; | |
759 | } | |
760 | ||
4ed8e27b | 761 | int |
6dde2707 DC |
762 | xfs_buf_read_map( |
763 | struct xfs_buftarg *target, | |
764 | struct xfs_buf_map *map, | |
765 | int nmaps, | |
c3f8fc73 | 766 | xfs_buf_flags_t flags, |
4ed8e27b | 767 | struct xfs_buf **bpp, |
cdbcf82b DW |
768 | const struct xfs_buf_ops *ops, |
769 | xfs_failaddr_t fa) | |
1da177e4 | 770 | { |
6dde2707 | 771 | struct xfs_buf *bp; |
3848b5f6 | 772 | int error; |
ce8e922c NS |
773 | |
774 | flags |= XBF_READ; | |
4ed8e27b | 775 | *bpp = NULL; |
ce8e922c | 776 | |
3848b5f6 DW |
777 | error = xfs_buf_get_map(target, map, nmaps, flags, &bp); |
778 | if (error) | |
4ed8e27b | 779 | return error; |
0b1b213f | 780 | |
1aff5696 DW |
781 | trace_xfs_buf_read(bp, flags, _RET_IP_); |
782 | ||
783 | if (!(bp->b_flags & XBF_DONE)) { | |
4ed8e27b | 784 | /* Initiate the buffer read and wait. */ |
1aff5696 DW |
785 | XFS_STATS_INC(target->bt_mount, xb_get_read); |
786 | bp->b_ops = ops; | |
4ed8e27b DW |
787 | error = _xfs_buf_read(bp, flags); |
788 | ||
789 | /* Readahead iodone already dropped the buffer, so exit. */ | |
790 | if (flags & XBF_ASYNC) | |
791 | return 0; | |
792 | } else { | |
793 | /* Buffer already read; all we need to do is check it. */ | |
794 | error = xfs_buf_reverify(bp, ops); | |
795 | ||
796 | /* Readahead already finished; drop the buffer and exit. */ | |
797 | if (flags & XBF_ASYNC) { | |
798 | xfs_buf_relse(bp); | |
799 | return 0; | |
800 | } | |
801 | ||
802 | /* We do not want read in the flags */ | |
803 | bp->b_flags &= ~XBF_READ; | |
804 | ASSERT(bp->b_ops != NULL || ops == NULL); | |
1aff5696 DW |
805 | } |
806 | ||
4ed8e27b DW |
807 | /* |
808 | * If we've had a read error, then the contents of the buffer are | |
809 | * invalid and should not be used. To ensure that a followup read tries | |
810 | * to pull the buffer from disk again, we clear the XBF_DONE flag and | |
811 | * mark the buffer stale. This ensures that anyone who has a current | |
812 | * reference to the buffer will interpret it's contents correctly and | |
813 | * future cache lookups will also treat it as an empty, uninitialised | |
814 | * buffer. | |
815 | */ | |
816 | if (error) { | |
01728b44 DC |
817 | /* |
818 | * Check against log shutdown for error reporting because | |
819 | * metadata writeback may require a read first and we need to | |
820 | * report errors in metadata writeback until the log is shut | |
821 | * down. High level transaction read functions already check | |
822 | * against mount shutdown, anyway, so we only need to be | |
823 | * concerned about low level IO interactions here. | |
824 | */ | |
825 | if (!xlog_is_shutdown(target->bt_mount->m_log)) | |
cdbcf82b | 826 | xfs_buf_ioerror_alert(bp, fa); |
1aff5696 | 827 | |
4ed8e27b DW |
828 | bp->b_flags &= ~XBF_DONE; |
829 | xfs_buf_stale(bp); | |
1aff5696 | 830 | xfs_buf_relse(bp); |
4ed8e27b DW |
831 | |
832 | /* bad CRC means corrupted metadata */ | |
833 | if (error == -EFSBADCRC) | |
834 | error = -EFSCORRUPTED; | |
835 | return error; | |
1da177e4 LT |
836 | } |
837 | ||
4ed8e27b DW |
838 | *bpp = bp; |
839 | return 0; | |
1da177e4 LT |
840 | } |
841 | ||
1da177e4 | 842 | /* |
ce8e922c NS |
843 | * If we are not low on memory then do the readahead in a deadlock |
844 | * safe manner. | |
1da177e4 LT |
845 | */ |
846 | void | |
6dde2707 DC |
847 | xfs_buf_readahead_map( |
848 | struct xfs_buftarg *target, | |
849 | struct xfs_buf_map *map, | |
c3f8fc73 | 850 | int nmaps, |
1813dd64 | 851 | const struct xfs_buf_ops *ops) |
1da177e4 | 852 | { |
4ed8e27b DW |
853 | struct xfs_buf *bp; |
854 | ||
6dde2707 | 855 | xfs_buf_read_map(target, map, nmaps, |
cdbcf82b DW |
856 | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD, &bp, ops, |
857 | __this_address); | |
1da177e4 LT |
858 | } |
859 | ||
5adc94c2 DC |
860 | /* |
861 | * Read an uncached buffer from disk. Allocates and returns a locked | |
4c7f65ae DC |
862 | * buffer containing the disk contents or nothing. Uncached buffers always have |
863 | * a cache index of XFS_BUF_DADDR_NULL so we can easily determine if the buffer | |
864 | * is cached or uncached during fault diagnosis. | |
5adc94c2 | 865 | */ |
ba372674 | 866 | int |
5adc94c2 | 867 | xfs_buf_read_uncached( |
5adc94c2 DC |
868 | struct xfs_buftarg *target, |
869 | xfs_daddr_t daddr, | |
e70b73f8 | 870 | size_t numblks, |
b9b3fe15 | 871 | xfs_buf_flags_t flags, |
ba372674 | 872 | struct xfs_buf **bpp, |
1813dd64 | 873 | const struct xfs_buf_ops *ops) |
5adc94c2 | 874 | { |
eab4e633 | 875 | struct xfs_buf *bp; |
2842b6db | 876 | int error; |
5adc94c2 | 877 | |
ba372674 DC |
878 | *bpp = NULL; |
879 | ||
2842b6db DW |
880 | error = xfs_buf_get_uncached(target, numblks, flags, &bp); |
881 | if (error) | |
882 | return error; | |
5adc94c2 DC |
883 | |
884 | /* set up the buffer for a read IO */ | |
3e85c868 | 885 | ASSERT(bp->b_map_count == 1); |
4c7f65ae | 886 | bp->b_rhash_key = XFS_BUF_DADDR_NULL; |
3e85c868 | 887 | bp->b_maps[0].bm_bn = daddr; |
cbb7baab | 888 | bp->b_flags |= XBF_READ; |
1813dd64 | 889 | bp->b_ops = ops; |
5adc94c2 | 890 | |
6af88cda | 891 | xfs_buf_submit(bp); |
ba372674 | 892 | if (bp->b_error) { |
2842b6db | 893 | error = bp->b_error; |
83a0adc3 | 894 | xfs_buf_relse(bp); |
ba372674 | 895 | return error; |
83a0adc3 | 896 | } |
ba372674 DC |
897 | |
898 | *bpp = bp; | |
899 | return 0; | |
1da177e4 LT |
900 | } |
901 | ||
2842b6db | 902 | int |
686865f7 DC |
903 | xfs_buf_get_uncached( |
904 | struct xfs_buftarg *target, | |
e70b73f8 | 905 | size_t numblks, |
b9b3fe15 | 906 | xfs_buf_flags_t flags, |
2842b6db | 907 | struct xfs_buf **bpp) |
1da177e4 | 908 | { |
07b5c5ad | 909 | int error; |
3e85c868 DC |
910 | struct xfs_buf *bp; |
911 | DEFINE_SINGLE_BUF_MAP(map, XFS_BUF_DADDR_NULL, numblks); | |
1da177e4 | 912 | |
2842b6db DW |
913 | *bpp = NULL; |
914 | ||
c891c30a | 915 | /* flags might contain irrelevant bits, pass only what we care about */ |
32dff5e5 DW |
916 | error = _xfs_buf_alloc(target, &map, 1, flags & XBF_NO_IOACCT, &bp); |
917 | if (error) | |
07b5c5ad | 918 | return error; |
1da177e4 | 919 | |
934d1076 | 920 | error = xfs_buf_alloc_pages(bp, flags); |
1fa40b01 | 921 | if (error) |
1da177e4 LT |
922 | goto fail_free_buf; |
923 | ||
611c9946 | 924 | error = _xfs_buf_map_pages(bp, 0); |
1fa40b01 | 925 | if (unlikely(error)) { |
4f10700a | 926 | xfs_warn(target->bt_mount, |
08e96e1a | 927 | "%s: failed to map pages", __func__); |
07b5c5ad | 928 | goto fail_free_buf; |
1fa40b01 | 929 | } |
1da177e4 | 930 | |
686865f7 | 931 | trace_xfs_buf_get_uncached(bp, _RET_IP_); |
2842b6db DW |
932 | *bpp = bp; |
933 | return 0; | |
1fa40b01 | 934 | |
07b5c5ad DC |
935 | fail_free_buf: |
936 | xfs_buf_free(bp); | |
2842b6db | 937 | return error; |
1da177e4 LT |
938 | } |
939 | ||
940 | /* | |
1da177e4 LT |
941 | * Increment reference count on buffer, to hold the buffer concurrently |
942 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
943 | * Must hold the buffer already to call this function. |
944 | */ | |
945 | void | |
ce8e922c | 946 | xfs_buf_hold( |
e8222613 | 947 | struct xfs_buf *bp) |
1da177e4 | 948 | { |
0b1b213f | 949 | trace_xfs_buf_hold(bp, _RET_IP_); |
ce8e922c | 950 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
951 | } |
952 | ||
953 | /* | |
9c7504aa BF |
954 | * Release a hold on the specified buffer. If the hold count is 1, the buffer is |
955 | * placed on LRU or freed (depending on b_lru_ref). | |
1da177e4 LT |
956 | */ |
957 | void | |
ce8e922c | 958 | xfs_buf_rele( |
e8222613 | 959 | struct xfs_buf *bp) |
1da177e4 | 960 | { |
74f75a0c | 961 | struct xfs_perag *pag = bp->b_pag; |
9c7504aa BF |
962 | bool release; |
963 | bool freebuf = false; | |
1da177e4 | 964 | |
0b1b213f | 965 | trace_xfs_buf_rele(bp, _RET_IP_); |
1da177e4 | 966 | |
74f75a0c | 967 | if (!pag) { |
430cbeb8 | 968 | ASSERT(list_empty(&bp->b_lru)); |
9c7504aa BF |
969 | if (atomic_dec_and_test(&bp->b_hold)) { |
970 | xfs_buf_ioacct_dec(bp); | |
fad3aa1e | 971 | xfs_buf_free(bp); |
9c7504aa | 972 | } |
fad3aa1e NS |
973 | return; |
974 | } | |
975 | ||
3790689f | 976 | ASSERT(atomic_read(&bp->b_hold) > 0); |
a4082357 | 977 | |
37fd1678 DC |
978 | /* |
979 | * We grab the b_lock here first to serialise racing xfs_buf_rele() | |
980 | * calls. The pag_buf_lock being taken on the last reference only | |
981 | * serialises against racing lookups in xfs_buf_find(). IOWs, the second | |
982 | * to last reference we drop here is not serialised against the last | |
983 | * reference until we take bp->b_lock. Hence if we don't grab b_lock | |
984 | * first, the last "release" reference can win the race to the lock and | |
985 | * free the buffer before the second-to-last reference is processed, | |
986 | * leading to a use-after-free scenario. | |
987 | */ | |
9c7504aa | 988 | spin_lock(&bp->b_lock); |
37fd1678 | 989 | release = atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock); |
9c7504aa BF |
990 | if (!release) { |
991 | /* | |
992 | * Drop the in-flight state if the buffer is already on the LRU | |
993 | * and it holds the only reference. This is racy because we | |
994 | * haven't acquired the pag lock, but the use of _XBF_IN_FLIGHT | |
995 | * ensures the decrement occurs only once per-buf. | |
996 | */ | |
997 | if ((atomic_read(&bp->b_hold) == 1) && !list_empty(&bp->b_lru)) | |
63db7c81 | 998 | __xfs_buf_ioacct_dec(bp); |
9c7504aa BF |
999 | goto out_unlock; |
1000 | } | |
1001 | ||
1002 | /* the last reference has been dropped ... */ | |
63db7c81 | 1003 | __xfs_buf_ioacct_dec(bp); |
9c7504aa BF |
1004 | if (!(bp->b_flags & XBF_STALE) && atomic_read(&bp->b_lru_ref)) { |
1005 | /* | |
1006 | * If the buffer is added to the LRU take a new reference to the | |
1007 | * buffer for the LRU and clear the (now stale) dispose list | |
1008 | * state flag | |
1009 | */ | |
1010 | if (list_lru_add(&bp->b_target->bt_lru, &bp->b_lru)) { | |
1011 | bp->b_state &= ~XFS_BSTATE_DISPOSE; | |
1012 | atomic_inc(&bp->b_hold); | |
1da177e4 | 1013 | } |
9c7504aa BF |
1014 | spin_unlock(&pag->pag_buf_lock); |
1015 | } else { | |
1016 | /* | |
1017 | * most of the time buffers will already be removed from the | |
1018 | * LRU, so optimise that case by checking for the | |
1019 | * XFS_BSTATE_DISPOSE flag indicating the last list the buffer | |
1020 | * was on was the disposal list | |
1021 | */ | |
1022 | if (!(bp->b_state & XFS_BSTATE_DISPOSE)) { | |
1023 | list_lru_del(&bp->b_target->bt_lru, &bp->b_lru); | |
1024 | } else { | |
1025 | ASSERT(list_empty(&bp->b_lru)); | |
1da177e4 | 1026 | } |
9c7504aa BF |
1027 | |
1028 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); | |
6031e73a LS |
1029 | rhashtable_remove_fast(&pag->pag_buf_hash, &bp->b_rhash_head, |
1030 | xfs_buf_hash_params); | |
9c7504aa BF |
1031 | spin_unlock(&pag->pag_buf_lock); |
1032 | xfs_perag_put(pag); | |
1033 | freebuf = true; | |
1da177e4 | 1034 | } |
9c7504aa BF |
1035 | |
1036 | out_unlock: | |
1037 | spin_unlock(&bp->b_lock); | |
1038 | ||
1039 | if (freebuf) | |
1040 | xfs_buf_free(bp); | |
1da177e4 LT |
1041 | } |
1042 | ||
1043 | ||
1044 | /* | |
0e6e847f | 1045 | * Lock a buffer object, if it is not already locked. |
90810b9e DC |
1046 | * |
1047 | * If we come across a stale, pinned, locked buffer, we know that we are | |
1048 | * being asked to lock a buffer that has been reallocated. Because it is | |
1049 | * pinned, we know that the log has not been pushed to disk and hence it | |
1050 | * will still be locked. Rather than continuing to have trylock attempts | |
1051 | * fail until someone else pushes the log, push it ourselves before | |
1052 | * returning. This means that the xfsaild will not get stuck trying | |
1053 | * to push on stale inode buffers. | |
1da177e4 LT |
1054 | */ |
1055 | int | |
0c842ad4 CH |
1056 | xfs_buf_trylock( |
1057 | struct xfs_buf *bp) | |
1da177e4 LT |
1058 | { |
1059 | int locked; | |
1060 | ||
ce8e922c | 1061 | locked = down_trylock(&bp->b_sema) == 0; |
fa6c668d | 1062 | if (locked) |
479c6412 | 1063 | trace_xfs_buf_trylock(bp, _RET_IP_); |
fa6c668d | 1064 | else |
479c6412 | 1065 | trace_xfs_buf_trylock_fail(bp, _RET_IP_); |
0c842ad4 | 1066 | return locked; |
1da177e4 | 1067 | } |
1da177e4 LT |
1068 | |
1069 | /* | |
0e6e847f | 1070 | * Lock a buffer object. |
ed3b4d6c DC |
1071 | * |
1072 | * If we come across a stale, pinned, locked buffer, we know that we | |
1073 | * are being asked to lock a buffer that has been reallocated. Because | |
1074 | * it is pinned, we know that the log has not been pushed to disk and | |
1075 | * hence it will still be locked. Rather than sleeping until someone | |
1076 | * else pushes the log, push it ourselves before trying to get the lock. | |
1da177e4 | 1077 | */ |
ce8e922c NS |
1078 | void |
1079 | xfs_buf_lock( | |
0c842ad4 | 1080 | struct xfs_buf *bp) |
1da177e4 | 1081 | { |
0b1b213f CH |
1082 | trace_xfs_buf_lock(bp, _RET_IP_); |
1083 | ||
ed3b4d6c | 1084 | if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
dbd329f1 | 1085 | xfs_log_force(bp->b_mount, 0); |
ce8e922c | 1086 | down(&bp->b_sema); |
0b1b213f CH |
1087 | |
1088 | trace_xfs_buf_lock_done(bp, _RET_IP_); | |
1da177e4 LT |
1089 | } |
1090 | ||
1da177e4 | 1091 | void |
ce8e922c | 1092 | xfs_buf_unlock( |
0c842ad4 | 1093 | struct xfs_buf *bp) |
1da177e4 | 1094 | { |
20e8a063 BF |
1095 | ASSERT(xfs_buf_islocked(bp)); |
1096 | ||
ce8e922c | 1097 | up(&bp->b_sema); |
0b1b213f | 1098 | trace_xfs_buf_unlock(bp, _RET_IP_); |
1da177e4 LT |
1099 | } |
1100 | ||
ce8e922c NS |
1101 | STATIC void |
1102 | xfs_buf_wait_unpin( | |
e8222613 | 1103 | struct xfs_buf *bp) |
1da177e4 LT |
1104 | { |
1105 | DECLARE_WAITQUEUE (wait, current); | |
1106 | ||
ce8e922c | 1107 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
1108 | return; |
1109 | ||
ce8e922c | 1110 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1111 | for (;;) { |
1112 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 1113 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 1114 | break; |
7eaceacc | 1115 | io_schedule(); |
1da177e4 | 1116 | } |
ce8e922c | 1117 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1118 | set_current_state(TASK_RUNNING); |
1119 | } | |
1120 | ||
f58d0ea9 CH |
1121 | static void |
1122 | xfs_buf_ioerror_alert_ratelimited( | |
664ffb8a CH |
1123 | struct xfs_buf *bp) |
1124 | { | |
664ffb8a CH |
1125 | static unsigned long lasttime; |
1126 | static struct xfs_buftarg *lasttarg; | |
1127 | ||
664ffb8a CH |
1128 | if (bp->b_target != lasttarg || |
1129 | time_after(jiffies, (lasttime + 5*HZ))) { | |
1130 | lasttime = jiffies; | |
1131 | xfs_buf_ioerror_alert(bp, __this_address); | |
1132 | } | |
1133 | lasttarg = bp->b_target; | |
664ffb8a CH |
1134 | } |
1135 | ||
664ffb8a CH |
1136 | /* |
1137 | * Account for this latest trip around the retry handler, and decide if | |
1138 | * we've failed enough times to constitute a permanent failure. | |
1139 | */ | |
1140 | static bool | |
1141 | xfs_buf_ioerror_permanent( | |
1142 | struct xfs_buf *bp, | |
1143 | struct xfs_error_cfg *cfg) | |
1144 | { | |
1145 | struct xfs_mount *mp = bp->b_mount; | |
1146 | ||
1147 | if (cfg->max_retries != XFS_ERR_RETRY_FOREVER && | |
1148 | ++bp->b_retries > cfg->max_retries) | |
1149 | return true; | |
1150 | if (cfg->retry_timeout != XFS_ERR_RETRY_FOREVER && | |
1151 | time_after(jiffies, cfg->retry_timeout + bp->b_first_retry_time)) | |
1152 | return true; | |
1153 | ||
1154 | /* At unmount we may treat errors differently */ | |
2e973b2c | 1155 | if (xfs_is_unmounting(mp) && mp->m_fail_unmount) |
664ffb8a CH |
1156 | return true; |
1157 | ||
1158 | return false; | |
1159 | } | |
1160 | ||
1161 | /* | |
1162 | * On a sync write or shutdown we just want to stale the buffer and let the | |
1163 | * caller handle the error in bp->b_error appropriately. | |
1164 | * | |
1165 | * If the write was asynchronous then no one will be looking for the error. If | |
1166 | * this is the first failure of this type, clear the error state and write the | |
1167 | * buffer out again. This means we always retry an async write failure at least | |
1168 | * once, but we also need to set the buffer up to behave correctly now for | |
1169 | * repeated failures. | |
1170 | * | |
1171 | * If we get repeated async write failures, then we take action according to the | |
1172 | * error configuration we have been set up to use. | |
1173 | * | |
70796c6b CH |
1174 | * Returns true if this function took care of error handling and the caller must |
1175 | * not touch the buffer again. Return false if the caller should proceed with | |
1176 | * normal I/O completion handling. | |
664ffb8a | 1177 | */ |
70796c6b CH |
1178 | static bool |
1179 | xfs_buf_ioend_handle_error( | |
664ffb8a CH |
1180 | struct xfs_buf *bp) |
1181 | { | |
1182 | struct xfs_mount *mp = bp->b_mount; | |
1183 | struct xfs_error_cfg *cfg; | |
1184 | ||
f58d0ea9 | 1185 | /* |
01728b44 DC |
1186 | * If we've already shutdown the journal because of I/O errors, there's |
1187 | * no point in giving this a retry. | |
f58d0ea9 | 1188 | */ |
01728b44 | 1189 | if (xlog_is_shutdown(mp->m_log)) |
f58d0ea9 CH |
1190 | goto out_stale; |
1191 | ||
1192 | xfs_buf_ioerror_alert_ratelimited(bp); | |
1193 | ||
22c10589 CH |
1194 | /* |
1195 | * We're not going to bother about retrying this during recovery. | |
1196 | * One strike! | |
1197 | */ | |
1198 | if (bp->b_flags & _XBF_LOGRECOVERY) { | |
1199 | xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR); | |
1200 | return false; | |
1201 | } | |
1202 | ||
f58d0ea9 CH |
1203 | /* |
1204 | * Synchronous writes will have callers process the error. | |
1205 | */ | |
1206 | if (!(bp->b_flags & XBF_ASYNC)) | |
664ffb8a CH |
1207 | goto out_stale; |
1208 | ||
1209 | trace_xfs_buf_iodone_async(bp, _RET_IP_); | |
1210 | ||
1211 | cfg = xfs_error_get_cfg(mp, XFS_ERR_METADATA, bp->b_error); | |
3cc49884 CH |
1212 | if (bp->b_last_error != bp->b_error || |
1213 | !(bp->b_flags & (XBF_STALE | XBF_WRITE_FAIL))) { | |
1214 | bp->b_last_error = bp->b_error; | |
1215 | if (cfg->retry_timeout != XFS_ERR_RETRY_FOREVER && | |
1216 | !bp->b_first_retry_time) | |
1217 | bp->b_first_retry_time = jiffies; | |
1218 | goto resubmit; | |
664ffb8a CH |
1219 | } |
1220 | ||
1221 | /* | |
1222 | * Permanent error - we need to trigger a shutdown if we haven't already | |
1223 | * to indicate that inconsistency will result from this action. | |
1224 | */ | |
1225 | if (xfs_buf_ioerror_permanent(bp, cfg)) { | |
1226 | xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR); | |
1227 | goto out_stale; | |
1228 | } | |
1229 | ||
1230 | /* Still considered a transient error. Caller will schedule retries. */ | |
844c9358 CH |
1231 | if (bp->b_flags & _XBF_INODES) |
1232 | xfs_buf_inode_io_fail(bp); | |
1233 | else if (bp->b_flags & _XBF_DQUOTS) | |
1234 | xfs_buf_dquot_io_fail(bp); | |
1235 | else | |
1236 | ASSERT(list_empty(&bp->b_li_list)); | |
1237 | xfs_buf_ioerror(bp, 0); | |
1238 | xfs_buf_relse(bp); | |
70796c6b | 1239 | return true; |
664ffb8a | 1240 | |
3cc49884 CH |
1241 | resubmit: |
1242 | xfs_buf_ioerror(bp, 0); | |
55b7d711 | 1243 | bp->b_flags |= (XBF_DONE | XBF_WRITE_FAIL); |
3cc49884 | 1244 | xfs_buf_submit(bp); |
70796c6b | 1245 | return true; |
664ffb8a CH |
1246 | out_stale: |
1247 | xfs_buf_stale(bp); | |
1248 | bp->b_flags |= XBF_DONE; | |
55b7d711 | 1249 | bp->b_flags &= ~XBF_WRITE; |
664ffb8a | 1250 | trace_xfs_buf_error_relse(bp, _RET_IP_); |
70796c6b | 1251 | return false; |
664ffb8a | 1252 | } |
1da177e4 | 1253 | |
76b2d323 | 1254 | static void |
e8aaba9a DC |
1255 | xfs_buf_ioend( |
1256 | struct xfs_buf *bp) | |
1da177e4 | 1257 | { |
e8aaba9a | 1258 | trace_xfs_buf_iodone(bp, _RET_IP_); |
1813dd64 | 1259 | |
61be9c52 DC |
1260 | /* |
1261 | * Pull in IO completion errors now. We are guaranteed to be running | |
1262 | * single threaded, so we don't need the lock to read b_io_error. | |
1263 | */ | |
1264 | if (!bp->b_error && bp->b_io_error) | |
1265 | xfs_buf_ioerror(bp, bp->b_io_error); | |
1266 | ||
55b7d711 | 1267 | if (bp->b_flags & XBF_READ) { |
b01d1461 DC |
1268 | if (!bp->b_error && bp->b_ops) |
1269 | bp->b_ops->verify_read(bp); | |
1270 | if (!bp->b_error) | |
1271 | bp->b_flags |= XBF_DONE; | |
23fb5a93 CH |
1272 | } else { |
1273 | if (!bp->b_error) { | |
1274 | bp->b_flags &= ~XBF_WRITE_FAIL; | |
1275 | bp->b_flags |= XBF_DONE; | |
1276 | } | |
f593bf14 | 1277 | |
70796c6b | 1278 | if (unlikely(bp->b_error) && xfs_buf_ioend_handle_error(bp)) |
664ffb8a | 1279 | return; |
664ffb8a CH |
1280 | |
1281 | /* clear the retry state */ | |
1282 | bp->b_last_error = 0; | |
1283 | bp->b_retries = 0; | |
1284 | bp->b_first_retry_time = 0; | |
1285 | ||
1286 | /* | |
1287 | * Note that for things like remote attribute buffers, there may | |
1288 | * not be a buffer log item here, so processing the buffer log | |
1289 | * item must remain optional. | |
1290 | */ | |
1291 | if (bp->b_log_item) | |
1292 | xfs_buf_item_done(bp); | |
1293 | ||
23fb5a93 CH |
1294 | if (bp->b_flags & _XBF_INODES) |
1295 | xfs_buf_inode_iodone(bp); | |
1296 | else if (bp->b_flags & _XBF_DQUOTS) | |
1297 | xfs_buf_dquot_iodone(bp); | |
22c10589 | 1298 | |
0c7e5afb | 1299 | } |
6a7584b1 | 1300 | |
22c10589 CH |
1301 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD | |
1302 | _XBF_LOGRECOVERY); | |
55b7d711 | 1303 | |
6a7584b1 CH |
1304 | if (bp->b_flags & XBF_ASYNC) |
1305 | xfs_buf_relse(bp); | |
1306 | else | |
1307 | complete(&bp->b_iowait); | |
1da177e4 LT |
1308 | } |
1309 | ||
e8aaba9a DC |
1310 | static void |
1311 | xfs_buf_ioend_work( | |
1312 | struct work_struct *work) | |
1da177e4 | 1313 | { |
e8aaba9a | 1314 | struct xfs_buf *bp = |
e8222613 | 1315 | container_of(work, struct xfs_buf, b_ioend_work); |
0b1b213f | 1316 | |
e8aaba9a DC |
1317 | xfs_buf_ioend(bp); |
1318 | } | |
1da177e4 | 1319 | |
211fe1a4 | 1320 | static void |
e8aaba9a DC |
1321 | xfs_buf_ioend_async( |
1322 | struct xfs_buf *bp) | |
1323 | { | |
b29c70f5 | 1324 | INIT_WORK(&bp->b_ioend_work, xfs_buf_ioend_work); |
dbd329f1 | 1325 | queue_work(bp->b_mount->m_buf_workqueue, &bp->b_ioend_work); |
1da177e4 LT |
1326 | } |
1327 | ||
1da177e4 | 1328 | void |
31ca03c9 | 1329 | __xfs_buf_ioerror( |
e8222613 | 1330 | struct xfs_buf *bp, |
31ca03c9 DW |
1331 | int error, |
1332 | xfs_failaddr_t failaddr) | |
1da177e4 | 1333 | { |
2451337d DC |
1334 | ASSERT(error <= 0 && error >= -1000); |
1335 | bp->b_error = error; | |
31ca03c9 | 1336 | trace_xfs_buf_ioerror(bp, error, failaddr); |
1da177e4 LT |
1337 | } |
1338 | ||
901796af CH |
1339 | void |
1340 | xfs_buf_ioerror_alert( | |
1341 | struct xfs_buf *bp, | |
cdbcf82b | 1342 | xfs_failaddr_t func) |
901796af | 1343 | { |
f9bccfcc BF |
1344 | xfs_buf_alert_ratelimited(bp, "XFS: metadata IO error", |
1345 | "metadata I/O error in \"%pS\" at daddr 0x%llx len %d error %d", | |
04fcad80 | 1346 | func, (uint64_t)xfs_buf_daddr(bp), |
f9bccfcc | 1347 | bp->b_length, -bp->b_error); |
901796af CH |
1348 | } |
1349 | ||
54b3b1f6 BF |
1350 | /* |
1351 | * To simulate an I/O failure, the buffer must be locked and held with at least | |
1352 | * three references. The LRU reference is dropped by the stale call. The buf | |
1353 | * item reference is dropped via ioend processing. The third reference is owned | |
1354 | * by the caller and is dropped on I/O completion if the buffer is XBF_ASYNC. | |
1355 | */ | |
1356 | void | |
1357 | xfs_buf_ioend_fail( | |
1358 | struct xfs_buf *bp) | |
1359 | { | |
1360 | bp->b_flags &= ~XBF_DONE; | |
1361 | xfs_buf_stale(bp); | |
1362 | xfs_buf_ioerror(bp, -EIO); | |
1363 | xfs_buf_ioend(bp); | |
901796af CH |
1364 | } |
1365 | ||
a2dcf5df CH |
1366 | int |
1367 | xfs_bwrite( | |
1368 | struct xfs_buf *bp) | |
1369 | { | |
1370 | int error; | |
1371 | ||
1372 | ASSERT(xfs_buf_islocked(bp)); | |
1373 | ||
1374 | bp->b_flags |= XBF_WRITE; | |
27187754 | 1375 | bp->b_flags &= ~(XBF_ASYNC | XBF_READ | _XBF_DELWRI_Q | |
b6983e80 | 1376 | XBF_DONE); |
a2dcf5df | 1377 | |
6af88cda | 1378 | error = xfs_buf_submit(bp); |
dbd329f1 CH |
1379 | if (error) |
1380 | xfs_force_shutdown(bp->b_mount, SHUTDOWN_META_IO_ERROR); | |
a2dcf5df CH |
1381 | return error; |
1382 | } | |
1383 | ||
9bdd9bd6 | 1384 | static void |
ce8e922c | 1385 | xfs_buf_bio_end_io( |
4246a0b6 | 1386 | struct bio *bio) |
1da177e4 | 1387 | { |
9bdd9bd6 | 1388 | struct xfs_buf *bp = (struct xfs_buf *)bio->bi_private; |
1da177e4 | 1389 | |
7376d745 BF |
1390 | if (!bio->bi_status && |
1391 | (bp->b_flags & XBF_WRITE) && (bp->b_flags & XBF_ASYNC) && | |
43dc0aa8 | 1392 | XFS_TEST_ERROR(false, bp->b_mount, XFS_ERRTAG_BUF_IOERROR)) |
7376d745 | 1393 | bio->bi_status = BLK_STS_IOERR; |
1da177e4 | 1394 | |
37eb17e6 DC |
1395 | /* |
1396 | * don't overwrite existing errors - otherwise we can lose errors on | |
1397 | * buffers that require multiple bios to complete. | |
1398 | */ | |
4e4cbee9 CH |
1399 | if (bio->bi_status) { |
1400 | int error = blk_status_to_errno(bio->bi_status); | |
1401 | ||
1402 | cmpxchg(&bp->b_io_error, 0, error); | |
1403 | } | |
1da177e4 | 1404 | |
37eb17e6 | 1405 | if (!bp->b_error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ)) |
73c77e2c JB |
1406 | invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp)); |
1407 | ||
e8aaba9a DC |
1408 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) |
1409 | xfs_buf_ioend_async(bp); | |
1da177e4 | 1410 | bio_put(bio); |
1da177e4 LT |
1411 | } |
1412 | ||
3e85c868 DC |
1413 | static void |
1414 | xfs_buf_ioapply_map( | |
1415 | struct xfs_buf *bp, | |
1416 | int map, | |
1417 | int *buf_offset, | |
1418 | int *count, | |
2123ef85 | 1419 | int op) |
1da177e4 | 1420 | { |
3e85c868 | 1421 | int page_index; |
5f7136db | 1422 | unsigned int total_nr_pages = bp->b_page_count; |
3e85c868 DC |
1423 | int nr_pages; |
1424 | struct bio *bio; | |
1425 | sector_t sector = bp->b_maps[map].bm_bn; | |
1426 | int size; | |
1427 | int offset; | |
1da177e4 | 1428 | |
3e85c868 DC |
1429 | /* skip the pages in the buffer before the start offset */ |
1430 | page_index = 0; | |
1431 | offset = *buf_offset; | |
1432 | while (offset >= PAGE_SIZE) { | |
1433 | page_index++; | |
1434 | offset -= PAGE_SIZE; | |
f538d4da CH |
1435 | } |
1436 | ||
3e85c868 DC |
1437 | /* |
1438 | * Limit the IO size to the length of the current vector, and update the | |
1439 | * remaining IO count for the next time around. | |
1440 | */ | |
1441 | size = min_t(int, BBTOB(bp->b_maps[map].bm_len), *count); | |
1442 | *count -= size; | |
1443 | *buf_offset += size; | |
34951f5c | 1444 | |
1da177e4 | 1445 | next_chunk: |
ce8e922c | 1446 | atomic_inc(&bp->b_io_remaining); |
5f7136db | 1447 | nr_pages = bio_max_segs(total_nr_pages); |
1da177e4 | 1448 | |
07888c66 | 1449 | bio = bio_alloc(bp->b_target->bt_bdev, nr_pages, op, GFP_NOIO); |
4f024f37 | 1450 | bio->bi_iter.bi_sector = sector; |
ce8e922c NS |
1451 | bio->bi_end_io = xfs_buf_bio_end_io; |
1452 | bio->bi_private = bp; | |
0e6e847f | 1453 | |
3e85c868 | 1454 | for (; size && nr_pages; nr_pages--, page_index++) { |
0e6e847f | 1455 | int rbytes, nbytes = PAGE_SIZE - offset; |
1da177e4 LT |
1456 | |
1457 | if (nbytes > size) | |
1458 | nbytes = size; | |
1459 | ||
3e85c868 DC |
1460 | rbytes = bio_add_page(bio, bp->b_pages[page_index], nbytes, |
1461 | offset); | |
ce8e922c | 1462 | if (rbytes < nbytes) |
1da177e4 LT |
1463 | break; |
1464 | ||
1465 | offset = 0; | |
aa0e8833 | 1466 | sector += BTOBB(nbytes); |
1da177e4 LT |
1467 | size -= nbytes; |
1468 | total_nr_pages--; | |
1469 | } | |
1470 | ||
4f024f37 | 1471 | if (likely(bio->bi_iter.bi_size)) { |
73c77e2c JB |
1472 | if (xfs_buf_is_vmapped(bp)) { |
1473 | flush_kernel_vmap_range(bp->b_addr, | |
1474 | xfs_buf_vmap_len(bp)); | |
1475 | } | |
4e49ea4a | 1476 | submit_bio(bio); |
1da177e4 LT |
1477 | if (size) |
1478 | goto next_chunk; | |
1479 | } else { | |
37eb17e6 DC |
1480 | /* |
1481 | * This is guaranteed not to be the last io reference count | |
595bff75 | 1482 | * because the caller (xfs_buf_submit) holds a count itself. |
37eb17e6 DC |
1483 | */ |
1484 | atomic_dec(&bp->b_io_remaining); | |
2451337d | 1485 | xfs_buf_ioerror(bp, -EIO); |
ec53d1db | 1486 | bio_put(bio); |
1da177e4 | 1487 | } |
3e85c868 DC |
1488 | |
1489 | } | |
1490 | ||
1491 | STATIC void | |
1492 | _xfs_buf_ioapply( | |
1493 | struct xfs_buf *bp) | |
1494 | { | |
1495 | struct blk_plug plug; | |
50bfcd0c | 1496 | int op; |
3e85c868 DC |
1497 | int offset; |
1498 | int size; | |
1499 | int i; | |
1500 | ||
c163f9a1 DC |
1501 | /* |
1502 | * Make sure we capture only current IO errors rather than stale errors | |
1503 | * left over from previous use of the buffer (e.g. failed readahead). | |
1504 | */ | |
1505 | bp->b_error = 0; | |
1506 | ||
3e85c868 | 1507 | if (bp->b_flags & XBF_WRITE) { |
50bfcd0c | 1508 | op = REQ_OP_WRITE; |
1813dd64 DC |
1509 | |
1510 | /* | |
1511 | * Run the write verifier callback function if it exists. If | |
1512 | * this function fails it will mark the buffer with an error and | |
1513 | * the IO should not be dispatched. | |
1514 | */ | |
1515 | if (bp->b_ops) { | |
1516 | bp->b_ops->verify_write(bp); | |
1517 | if (bp->b_error) { | |
dbd329f1 | 1518 | xfs_force_shutdown(bp->b_mount, |
1813dd64 DC |
1519 | SHUTDOWN_CORRUPT_INCORE); |
1520 | return; | |
1521 | } | |
4c7f65ae | 1522 | } else if (bp->b_rhash_key != XFS_BUF_DADDR_NULL) { |
dbd329f1 | 1523 | struct xfs_mount *mp = bp->b_mount; |
400b9d88 DC |
1524 | |
1525 | /* | |
1526 | * non-crc filesystems don't attach verifiers during | |
1527 | * log recovery, so don't warn for such filesystems. | |
1528 | */ | |
38c26bfd | 1529 | if (xfs_has_crc(mp)) { |
400b9d88 | 1530 | xfs_warn(mp, |
c219b015 | 1531 | "%s: no buf ops on daddr 0x%llx len %d", |
4c7f65ae DC |
1532 | __func__, xfs_buf_daddr(bp), |
1533 | bp->b_length); | |
9c712a13 DW |
1534 | xfs_hex_dump(bp->b_addr, |
1535 | XFS_CORRUPTION_DUMP_LEN); | |
400b9d88 DC |
1536 | dump_stack(); |
1537 | } | |
1813dd64 | 1538 | } |
3e85c868 | 1539 | } else { |
50bfcd0c | 1540 | op = REQ_OP_READ; |
2123ef85 CH |
1541 | if (bp->b_flags & XBF_READ_AHEAD) |
1542 | op |= REQ_RAHEAD; | |
3e85c868 DC |
1543 | } |
1544 | ||
1545 | /* we only use the buffer cache for meta-data */ | |
2123ef85 | 1546 | op |= REQ_META; |
3e85c868 DC |
1547 | |
1548 | /* | |
1549 | * Walk all the vectors issuing IO on them. Set up the initial offset | |
1550 | * into the buffer and the desired IO size before we start - | |
1551 | * _xfs_buf_ioapply_vec() will modify them appropriately for each | |
1552 | * subsequent call. | |
1553 | */ | |
1554 | offset = bp->b_offset; | |
8124b9b6 | 1555 | size = BBTOB(bp->b_length); |
3e85c868 DC |
1556 | blk_start_plug(&plug); |
1557 | for (i = 0; i < bp->b_map_count; i++) { | |
2123ef85 | 1558 | xfs_buf_ioapply_map(bp, i, &offset, &size, op); |
3e85c868 DC |
1559 | if (bp->b_error) |
1560 | break; | |
1561 | if (size <= 0) | |
1562 | break; /* all done */ | |
1563 | } | |
1564 | blk_finish_plug(&plug); | |
1da177e4 LT |
1565 | } |
1566 | ||
595bff75 | 1567 | /* |
bb00b6f1 | 1568 | * Wait for I/O completion of a sync buffer and return the I/O error code. |
595bff75 | 1569 | */ |
eaebb515 | 1570 | static int |
bb00b6f1 | 1571 | xfs_buf_iowait( |
595bff75 | 1572 | struct xfs_buf *bp) |
1da177e4 | 1573 | { |
bb00b6f1 BF |
1574 | ASSERT(!(bp->b_flags & XBF_ASYNC)); |
1575 | ||
1576 | trace_xfs_buf_iowait(bp, _RET_IP_); | |
1577 | wait_for_completion(&bp->b_iowait); | |
1578 | trace_xfs_buf_iowait_done(bp, _RET_IP_); | |
1579 | ||
1580 | return bp->b_error; | |
1581 | } | |
1582 | ||
1583 | /* | |
1584 | * Buffer I/O submission path, read or write. Asynchronous submission transfers | |
1585 | * the buffer lock ownership and the current reference to the IO. It is not | |
1586 | * safe to reference the buffer after a call to this function unless the caller | |
1587 | * holds an additional reference itself. | |
1588 | */ | |
26e32875 | 1589 | static int |
bb00b6f1 BF |
1590 | __xfs_buf_submit( |
1591 | struct xfs_buf *bp, | |
1592 | bool wait) | |
1593 | { | |
1594 | int error = 0; | |
1595 | ||
595bff75 | 1596 | trace_xfs_buf_submit(bp, _RET_IP_); |
1da177e4 | 1597 | |
43ff2122 | 1598 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); |
595bff75 | 1599 | |
01728b44 DC |
1600 | /* |
1601 | * On log shutdown we stale and complete the buffer immediately. We can | |
1602 | * be called to read the superblock before the log has been set up, so | |
1603 | * be careful checking the log state. | |
1604 | * | |
1605 | * Checking the mount shutdown state here can result in the log tail | |
1606 | * moving inappropriately on disk as the log may not yet be shut down. | |
1607 | * i.e. failing this buffer on mount shutdown can remove it from the AIL | |
1608 | * and move the tail of the log forwards without having written this | |
1609 | * buffer to disk. This corrupts the log tail state in memory, and | |
1610 | * because the log may not be shut down yet, it can then be propagated | |
1611 | * to disk before the log is shutdown. Hence we check log shutdown | |
1612 | * state here rather than mount state to avoid corrupting the log tail | |
1613 | * on shutdown. | |
1614 | */ | |
1615 | if (bp->b_mount->m_log && | |
1616 | xlog_is_shutdown(bp->b_mount->m_log)) { | |
54b3b1f6 | 1617 | xfs_buf_ioend_fail(bp); |
eaebb515 | 1618 | return -EIO; |
595bff75 | 1619 | } |
1da177e4 | 1620 | |
bb00b6f1 BF |
1621 | /* |
1622 | * Grab a reference so the buffer does not go away underneath us. For | |
1623 | * async buffers, I/O completion drops the callers reference, which | |
1624 | * could occur before submission returns. | |
1625 | */ | |
1626 | xfs_buf_hold(bp); | |
1627 | ||
375ec69d | 1628 | if (bp->b_flags & XBF_WRITE) |
ce8e922c | 1629 | xfs_buf_wait_unpin(bp); |
e11bb805 | 1630 | |
61be9c52 DC |
1631 | /* clear the internal error state to avoid spurious errors */ |
1632 | bp->b_io_error = 0; | |
1633 | ||
8d6c1210 | 1634 | /* |
e11bb805 DC |
1635 | * Set the count to 1 initially, this will stop an I/O completion |
1636 | * callout which happens before we have started all the I/O from calling | |
1637 | * xfs_buf_ioend too early. | |
1da177e4 | 1638 | */ |
ce8e922c | 1639 | atomic_set(&bp->b_io_remaining, 1); |
eaebb515 BF |
1640 | if (bp->b_flags & XBF_ASYNC) |
1641 | xfs_buf_ioacct_inc(bp); | |
ce8e922c | 1642 | _xfs_buf_ioapply(bp); |
e11bb805 | 1643 | |
8d6c1210 | 1644 | /* |
595bff75 DC |
1645 | * If _xfs_buf_ioapply failed, we can get back here with only the IO |
1646 | * reference we took above. If we drop it to zero, run completion so | |
1647 | * that we don't return to the caller with completion still pending. | |
8d6c1210 | 1648 | */ |
e8aaba9a | 1649 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) { |
eaebb515 | 1650 | if (bp->b_error || !(bp->b_flags & XBF_ASYNC)) |
e8aaba9a DC |
1651 | xfs_buf_ioend(bp); |
1652 | else | |
1653 | xfs_buf_ioend_async(bp); | |
1654 | } | |
1da177e4 | 1655 | |
6af88cda BF |
1656 | if (wait) |
1657 | error = xfs_buf_iowait(bp); | |
bb00b6f1 | 1658 | |
595bff75 | 1659 | /* |
6af88cda BF |
1660 | * Release the hold that keeps the buffer referenced for the entire |
1661 | * I/O. Note that if the buffer is async, it is not safe to reference | |
1662 | * after this release. | |
595bff75 DC |
1663 | */ |
1664 | xfs_buf_rele(bp); | |
1665 | return error; | |
1da177e4 LT |
1666 | } |
1667 | ||
88ee2df7 | 1668 | void * |
ce8e922c | 1669 | xfs_buf_offset( |
88ee2df7 | 1670 | struct xfs_buf *bp, |
1da177e4 LT |
1671 | size_t offset) |
1672 | { | |
1673 | struct page *page; | |
1674 | ||
611c9946 | 1675 | if (bp->b_addr) |
62926044 | 1676 | return bp->b_addr + offset; |
1da177e4 | 1677 | |
0e6e847f | 1678 | page = bp->b_pages[offset >> PAGE_SHIFT]; |
88ee2df7 | 1679 | return page_address(page) + (offset & (PAGE_SIZE-1)); |
1da177e4 LT |
1680 | } |
1681 | ||
1da177e4 | 1682 | void |
f9a196ee CH |
1683 | xfs_buf_zero( |
1684 | struct xfs_buf *bp, | |
1685 | size_t boff, | |
1686 | size_t bsize) | |
1da177e4 | 1687 | { |
795cac72 | 1688 | size_t bend; |
1da177e4 LT |
1689 | |
1690 | bend = boff + bsize; | |
1691 | while (boff < bend) { | |
795cac72 DC |
1692 | struct page *page; |
1693 | int page_index, page_offset, csize; | |
1694 | ||
1695 | page_index = (boff + bp->b_offset) >> PAGE_SHIFT; | |
1696 | page_offset = (boff + bp->b_offset) & ~PAGE_MASK; | |
1697 | page = bp->b_pages[page_index]; | |
1698 | csize = min_t(size_t, PAGE_SIZE - page_offset, | |
8124b9b6 | 1699 | BBTOB(bp->b_length) - boff); |
1da177e4 | 1700 | |
795cac72 | 1701 | ASSERT((csize + page_offset) <= PAGE_SIZE); |
1da177e4 | 1702 | |
f9a196ee | 1703 | memset(page_address(page) + page_offset, 0, csize); |
1da177e4 LT |
1704 | |
1705 | boff += csize; | |
1da177e4 LT |
1706 | } |
1707 | } | |
1708 | ||
8d57c216 DW |
1709 | /* |
1710 | * Log a message about and stale a buffer that a caller has decided is corrupt. | |
1711 | * | |
1712 | * This function should be called for the kinds of metadata corruption that | |
1713 | * cannot be detect from a verifier, such as incorrect inter-block relationship | |
1714 | * data. Do /not/ call this function from a verifier function. | |
1715 | * | |
1716 | * The buffer must be XBF_DONE prior to the call. Afterwards, the buffer will | |
1717 | * be marked stale, but b_error will not be set. The caller is responsible for | |
1718 | * releasing the buffer or fixing it. | |
1719 | */ | |
1720 | void | |
1721 | __xfs_buf_mark_corrupt( | |
1722 | struct xfs_buf *bp, | |
1723 | xfs_failaddr_t fa) | |
1724 | { | |
1725 | ASSERT(bp->b_flags & XBF_DONE); | |
1726 | ||
e83cf875 | 1727 | xfs_buf_corruption_error(bp, fa); |
8d57c216 DW |
1728 | xfs_buf_stale(bp); |
1729 | } | |
1730 | ||
1da177e4 | 1731 | /* |
ce8e922c | 1732 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1733 | */ |
1734 | ||
1735 | /* | |
430cbeb8 DC |
1736 | * Wait for any bufs with callbacks that have been submitted but have not yet |
1737 | * returned. These buffers will have an elevated hold count, so wait on those | |
1738 | * while freeing all the buffers only held by the LRU. | |
1da177e4 | 1739 | */ |
e80dfa19 | 1740 | static enum lru_status |
10fb9ac1 | 1741 | xfs_buftarg_drain_rele( |
e80dfa19 | 1742 | struct list_head *item, |
3f97b163 | 1743 | struct list_lru_one *lru, |
e80dfa19 DC |
1744 | spinlock_t *lru_lock, |
1745 | void *arg) | |
1746 | ||
1da177e4 | 1747 | { |
e80dfa19 | 1748 | struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru); |
a4082357 | 1749 | struct list_head *dispose = arg; |
430cbeb8 | 1750 | |
e80dfa19 | 1751 | if (atomic_read(&bp->b_hold) > 1) { |
a4082357 | 1752 | /* need to wait, so skip it this pass */ |
10fb9ac1 | 1753 | trace_xfs_buf_drain_buftarg(bp, _RET_IP_); |
a4082357 | 1754 | return LRU_SKIP; |
1da177e4 | 1755 | } |
a4082357 DC |
1756 | if (!spin_trylock(&bp->b_lock)) |
1757 | return LRU_SKIP; | |
e80dfa19 | 1758 | |
a4082357 DC |
1759 | /* |
1760 | * clear the LRU reference count so the buffer doesn't get | |
1761 | * ignored in xfs_buf_rele(). | |
1762 | */ | |
1763 | atomic_set(&bp->b_lru_ref, 0); | |
1764 | bp->b_state |= XFS_BSTATE_DISPOSE; | |
3f97b163 | 1765 | list_lru_isolate_move(lru, item, dispose); |
a4082357 DC |
1766 | spin_unlock(&bp->b_lock); |
1767 | return LRU_REMOVED; | |
1da177e4 LT |
1768 | } |
1769 | ||
8321ddb2 BF |
1770 | /* |
1771 | * Wait for outstanding I/O on the buftarg to complete. | |
1772 | */ | |
e80dfa19 | 1773 | void |
8321ddb2 | 1774 | xfs_buftarg_wait( |
e80dfa19 DC |
1775 | struct xfs_buftarg *btp) |
1776 | { | |
85bec546 | 1777 | /* |
9c7504aa BF |
1778 | * First wait on the buftarg I/O count for all in-flight buffers to be |
1779 | * released. This is critical as new buffers do not make the LRU until | |
1780 | * they are released. | |
1781 | * | |
1782 | * Next, flush the buffer workqueue to ensure all completion processing | |
1783 | * has finished. Just waiting on buffer locks is not sufficient for | |
1784 | * async IO as the reference count held over IO is not released until | |
1785 | * after the buffer lock is dropped. Hence we need to ensure here that | |
1786 | * all reference counts have been dropped before we start walking the | |
1787 | * LRU list. | |
85bec546 | 1788 | */ |
9c7504aa BF |
1789 | while (percpu_counter_sum(&btp->bt_io_count)) |
1790 | delay(100); | |
800b2694 | 1791 | flush_workqueue(btp->bt_mount->m_buf_workqueue); |
8321ddb2 BF |
1792 | } |
1793 | ||
1794 | void | |
1795 | xfs_buftarg_drain( | |
1796 | struct xfs_buftarg *btp) | |
1797 | { | |
1798 | LIST_HEAD(dispose); | |
1799 | int loop = 0; | |
1800 | bool write_fail = false; | |
1801 | ||
1802 | xfs_buftarg_wait(btp); | |
85bec546 | 1803 | |
a4082357 DC |
1804 | /* loop until there is nothing left on the lru list. */ |
1805 | while (list_lru_count(&btp->bt_lru)) { | |
10fb9ac1 | 1806 | list_lru_walk(&btp->bt_lru, xfs_buftarg_drain_rele, |
a4082357 DC |
1807 | &dispose, LONG_MAX); |
1808 | ||
1809 | while (!list_empty(&dispose)) { | |
1810 | struct xfs_buf *bp; | |
1811 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); | |
1812 | list_del_init(&bp->b_lru); | |
ac8809f9 | 1813 | if (bp->b_flags & XBF_WRITE_FAIL) { |
61948b6f BF |
1814 | write_fail = true; |
1815 | xfs_buf_alert_ratelimited(bp, | |
1816 | "XFS: Corruption Alert", | |
c219b015 | 1817 | "Corruption Alert: Buffer at daddr 0x%llx had permanent write failures!", |
4c7f65ae | 1818 | (long long)xfs_buf_daddr(bp)); |
ac8809f9 | 1819 | } |
a4082357 DC |
1820 | xfs_buf_rele(bp); |
1821 | } | |
1822 | if (loop++ != 0) | |
1823 | delay(100); | |
1824 | } | |
61948b6f BF |
1825 | |
1826 | /* | |
1827 | * If one or more failed buffers were freed, that means dirty metadata | |
1828 | * was thrown away. This should only ever happen after I/O completion | |
1829 | * handling has elevated I/O error(s) to permanent failures and shuts | |
01728b44 | 1830 | * down the journal. |
61948b6f BF |
1831 | */ |
1832 | if (write_fail) { | |
01728b44 | 1833 | ASSERT(xlog_is_shutdown(btp->bt_mount->m_log)); |
61948b6f BF |
1834 | xfs_alert(btp->bt_mount, |
1835 | "Please run xfs_repair to determine the extent of the problem."); | |
1836 | } | |
e80dfa19 DC |
1837 | } |
1838 | ||
1839 | static enum lru_status | |
1840 | xfs_buftarg_isolate( | |
1841 | struct list_head *item, | |
3f97b163 | 1842 | struct list_lru_one *lru, |
e80dfa19 DC |
1843 | spinlock_t *lru_lock, |
1844 | void *arg) | |
1845 | { | |
1846 | struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru); | |
1847 | struct list_head *dispose = arg; | |
1848 | ||
a4082357 DC |
1849 | /* |
1850 | * we are inverting the lru lock/bp->b_lock here, so use a trylock. | |
1851 | * If we fail to get the lock, just skip it. | |
1852 | */ | |
1853 | if (!spin_trylock(&bp->b_lock)) | |
1854 | return LRU_SKIP; | |
e80dfa19 DC |
1855 | /* |
1856 | * Decrement the b_lru_ref count unless the value is already | |
1857 | * zero. If the value is already zero, we need to reclaim the | |
1858 | * buffer, otherwise it gets another trip through the LRU. | |
1859 | */ | |
19957a18 | 1860 | if (atomic_add_unless(&bp->b_lru_ref, -1, 0)) { |
a4082357 | 1861 | spin_unlock(&bp->b_lock); |
e80dfa19 | 1862 | return LRU_ROTATE; |
a4082357 | 1863 | } |
e80dfa19 | 1864 | |
a4082357 | 1865 | bp->b_state |= XFS_BSTATE_DISPOSE; |
3f97b163 | 1866 | list_lru_isolate_move(lru, item, dispose); |
a4082357 | 1867 | spin_unlock(&bp->b_lock); |
e80dfa19 DC |
1868 | return LRU_REMOVED; |
1869 | } | |
1870 | ||
addbda40 | 1871 | static unsigned long |
e80dfa19 | 1872 | xfs_buftarg_shrink_scan( |
ff57ab21 | 1873 | struct shrinker *shrink, |
1495f230 | 1874 | struct shrink_control *sc) |
a6867a68 | 1875 | { |
ff57ab21 DC |
1876 | struct xfs_buftarg *btp = container_of(shrink, |
1877 | struct xfs_buftarg, bt_shrinker); | |
430cbeb8 | 1878 | LIST_HEAD(dispose); |
addbda40 | 1879 | unsigned long freed; |
430cbeb8 | 1880 | |
503c358c VD |
1881 | freed = list_lru_shrink_walk(&btp->bt_lru, sc, |
1882 | xfs_buftarg_isolate, &dispose); | |
430cbeb8 DC |
1883 | |
1884 | while (!list_empty(&dispose)) { | |
e80dfa19 | 1885 | struct xfs_buf *bp; |
430cbeb8 DC |
1886 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); |
1887 | list_del_init(&bp->b_lru); | |
1888 | xfs_buf_rele(bp); | |
1889 | } | |
1890 | ||
e80dfa19 DC |
1891 | return freed; |
1892 | } | |
1893 | ||
addbda40 | 1894 | static unsigned long |
e80dfa19 DC |
1895 | xfs_buftarg_shrink_count( |
1896 | struct shrinker *shrink, | |
1897 | struct shrink_control *sc) | |
1898 | { | |
1899 | struct xfs_buftarg *btp = container_of(shrink, | |
1900 | struct xfs_buftarg, bt_shrinker); | |
503c358c | 1901 | return list_lru_shrink_count(&btp->bt_lru, sc); |
a6867a68 DC |
1902 | } |
1903 | ||
1da177e4 LT |
1904 | void |
1905 | xfs_free_buftarg( | |
b7963133 | 1906 | struct xfs_buftarg *btp) |
1da177e4 | 1907 | { |
ff57ab21 | 1908 | unregister_shrinker(&btp->bt_shrinker); |
9c7504aa BF |
1909 | ASSERT(percpu_counter_sum(&btp->bt_io_count) == 0); |
1910 | percpu_counter_destroy(&btp->bt_io_count); | |
f5e1dd34 | 1911 | list_lru_destroy(&btp->bt_lru); |
ff57ab21 | 1912 | |
b5071ada | 1913 | blkdev_issue_flush(btp->bt_bdev); |
5b5abbef | 1914 | fs_put_dax(btp->bt_daxdev); |
a6867a68 | 1915 | |
f0e2d93c | 1916 | kmem_free(btp); |
1da177e4 LT |
1917 | } |
1918 | ||
3fefdeee ES |
1919 | int |
1920 | xfs_setsize_buftarg( | |
1da177e4 | 1921 | xfs_buftarg_t *btp, |
3fefdeee | 1922 | unsigned int sectorsize) |
1da177e4 | 1923 | { |
7c71ee78 | 1924 | /* Set up metadata sector size info */ |
6da54179 ES |
1925 | btp->bt_meta_sectorsize = sectorsize; |
1926 | btp->bt_meta_sectormask = sectorsize - 1; | |
1da177e4 | 1927 | |
ce8e922c | 1928 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
4f10700a | 1929 | xfs_warn(btp->bt_mount, |
a1c6f057 DM |
1930 | "Cannot set_blocksize to %u on device %pg", |
1931 | sectorsize, btp->bt_bdev); | |
2451337d | 1932 | return -EINVAL; |
1da177e4 LT |
1933 | } |
1934 | ||
7c71ee78 ES |
1935 | /* Set up device logical sector size mask */ |
1936 | btp->bt_logical_sectorsize = bdev_logical_block_size(btp->bt_bdev); | |
1937 | btp->bt_logical_sectormask = bdev_logical_block_size(btp->bt_bdev) - 1; | |
1938 | ||
1da177e4 LT |
1939 | return 0; |
1940 | } | |
1941 | ||
1942 | /* | |
3fefdeee ES |
1943 | * When allocating the initial buffer target we have not yet |
1944 | * read in the superblock, so don't know what sized sectors | |
1945 | * are being used at this early stage. Play safe. | |
ce8e922c | 1946 | */ |
1da177e4 LT |
1947 | STATIC int |
1948 | xfs_setsize_buftarg_early( | |
1949 | xfs_buftarg_t *btp, | |
1950 | struct block_device *bdev) | |
1951 | { | |
a96c4151 | 1952 | return xfs_setsize_buftarg(btp, bdev_logical_block_size(bdev)); |
1da177e4 LT |
1953 | } |
1954 | ||
5b5abbef | 1955 | struct xfs_buftarg * |
1da177e4 | 1956 | xfs_alloc_buftarg( |
ebad861b | 1957 | struct xfs_mount *mp, |
5b5abbef | 1958 | struct block_device *bdev) |
1da177e4 LT |
1959 | { |
1960 | xfs_buftarg_t *btp; | |
1961 | ||
707e0dda | 1962 | btp = kmem_zalloc(sizeof(*btp), KM_NOFS); |
1da177e4 | 1963 | |
ebad861b | 1964 | btp->bt_mount = mp; |
ce8e922c NS |
1965 | btp->bt_dev = bdev->bd_dev; |
1966 | btp->bt_bdev = bdev; | |
cd913c76 | 1967 | btp->bt_daxdev = fs_dax_get_by_bdev(bdev, &btp->bt_dax_part_off); |
0e6e847f | 1968 | |
f9bccfcc BF |
1969 | /* |
1970 | * Buffer IO error rate limiting. Limit it to no more than 10 messages | |
1971 | * per 30 seconds so as to not spam logs too much on repeated errors. | |
1972 | */ | |
1973 | ratelimit_state_init(&btp->bt_ioerror_rl, 30 * HZ, | |
1974 | DEFAULT_RATELIMIT_BURST); | |
1975 | ||
1da177e4 | 1976 | if (xfs_setsize_buftarg_early(btp, bdev)) |
d210a987 | 1977 | goto error_free; |
5ca302c8 GC |
1978 | |
1979 | if (list_lru_init(&btp->bt_lru)) | |
d210a987 | 1980 | goto error_free; |
5ca302c8 | 1981 | |
9c7504aa | 1982 | if (percpu_counter_init(&btp->bt_io_count, 0, GFP_KERNEL)) |
d210a987 | 1983 | goto error_lru; |
9c7504aa | 1984 | |
e80dfa19 DC |
1985 | btp->bt_shrinker.count_objects = xfs_buftarg_shrink_count; |
1986 | btp->bt_shrinker.scan_objects = xfs_buftarg_shrink_scan; | |
ff57ab21 | 1987 | btp->bt_shrinker.seeks = DEFAULT_SEEKS; |
e80dfa19 | 1988 | btp->bt_shrinker.flags = SHRINKER_NUMA_AWARE; |
d210a987 MH |
1989 | if (register_shrinker(&btp->bt_shrinker)) |
1990 | goto error_pcpu; | |
1da177e4 LT |
1991 | return btp; |
1992 | ||
d210a987 MH |
1993 | error_pcpu: |
1994 | percpu_counter_destroy(&btp->bt_io_count); | |
1995 | error_lru: | |
1996 | list_lru_destroy(&btp->bt_lru); | |
1997 | error_free: | |
f0e2d93c | 1998 | kmem_free(btp); |
1da177e4 LT |
1999 | return NULL; |
2000 | } | |
2001 | ||
20e8a063 BF |
2002 | /* |
2003 | * Cancel a delayed write list. | |
2004 | * | |
2005 | * Remove each buffer from the list, clear the delwri queue flag and drop the | |
2006 | * associated buffer reference. | |
2007 | */ | |
2008 | void | |
2009 | xfs_buf_delwri_cancel( | |
2010 | struct list_head *list) | |
2011 | { | |
2012 | struct xfs_buf *bp; | |
2013 | ||
2014 | while (!list_empty(list)) { | |
2015 | bp = list_first_entry(list, struct xfs_buf, b_list); | |
2016 | ||
2017 | xfs_buf_lock(bp); | |
2018 | bp->b_flags &= ~_XBF_DELWRI_Q; | |
2019 | list_del_init(&bp->b_list); | |
2020 | xfs_buf_relse(bp); | |
2021 | } | |
2022 | } | |
2023 | ||
1da177e4 | 2024 | /* |
43ff2122 CH |
2025 | * Add a buffer to the delayed write list. |
2026 | * | |
2027 | * This queues a buffer for writeout if it hasn't already been. Note that | |
2028 | * neither this routine nor the buffer list submission functions perform | |
2029 | * any internal synchronization. It is expected that the lists are thread-local | |
2030 | * to the callers. | |
2031 | * | |
2032 | * Returns true if we queued up the buffer, or false if it already had | |
2033 | * been on the buffer list. | |
1da177e4 | 2034 | */ |
43ff2122 | 2035 | bool |
ce8e922c | 2036 | xfs_buf_delwri_queue( |
43ff2122 CH |
2037 | struct xfs_buf *bp, |
2038 | struct list_head *list) | |
1da177e4 | 2039 | { |
43ff2122 | 2040 | ASSERT(xfs_buf_islocked(bp)); |
5a8ee6ba | 2041 | ASSERT(!(bp->b_flags & XBF_READ)); |
1da177e4 | 2042 | |
43ff2122 CH |
2043 | /* |
2044 | * If the buffer is already marked delwri it already is queued up | |
2045 | * by someone else for imediate writeout. Just ignore it in that | |
2046 | * case. | |
2047 | */ | |
2048 | if (bp->b_flags & _XBF_DELWRI_Q) { | |
2049 | trace_xfs_buf_delwri_queued(bp, _RET_IP_); | |
2050 | return false; | |
1da177e4 | 2051 | } |
1da177e4 | 2052 | |
43ff2122 | 2053 | trace_xfs_buf_delwri_queue(bp, _RET_IP_); |
d808f617 DC |
2054 | |
2055 | /* | |
43ff2122 CH |
2056 | * If a buffer gets written out synchronously or marked stale while it |
2057 | * is on a delwri list we lazily remove it. To do this, the other party | |
2058 | * clears the _XBF_DELWRI_Q flag but otherwise leaves the buffer alone. | |
2059 | * It remains referenced and on the list. In a rare corner case it | |
2060 | * might get readded to a delwri list after the synchronous writeout, in | |
2061 | * which case we need just need to re-add the flag here. | |
d808f617 | 2062 | */ |
43ff2122 CH |
2063 | bp->b_flags |= _XBF_DELWRI_Q; |
2064 | if (list_empty(&bp->b_list)) { | |
2065 | atomic_inc(&bp->b_hold); | |
2066 | list_add_tail(&bp->b_list, list); | |
585e6d88 | 2067 | } |
585e6d88 | 2068 | |
43ff2122 | 2069 | return true; |
585e6d88 DC |
2070 | } |
2071 | ||
089716aa DC |
2072 | /* |
2073 | * Compare function is more complex than it needs to be because | |
2074 | * the return value is only 32 bits and we are doing comparisons | |
2075 | * on 64 bit values | |
2076 | */ | |
2077 | static int | |
2078 | xfs_buf_cmp( | |
4f0f586b ST |
2079 | void *priv, |
2080 | const struct list_head *a, | |
2081 | const struct list_head *b) | |
089716aa DC |
2082 | { |
2083 | struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list); | |
2084 | struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); | |
2085 | xfs_daddr_t diff; | |
2086 | ||
f4b42421 | 2087 | diff = ap->b_maps[0].bm_bn - bp->b_maps[0].bm_bn; |
089716aa DC |
2088 | if (diff < 0) |
2089 | return -1; | |
2090 | if (diff > 0) | |
2091 | return 1; | |
2092 | return 0; | |
2093 | } | |
2094 | ||
26f1fe85 | 2095 | /* |
e339dd8d BF |
2096 | * Submit buffers for write. If wait_list is specified, the buffers are |
2097 | * submitted using sync I/O and placed on the wait list such that the caller can | |
2098 | * iowait each buffer. Otherwise async I/O is used and the buffers are released | |
2099 | * at I/O completion time. In either case, buffers remain locked until I/O | |
2100 | * completes and the buffer is released from the queue. | |
26f1fe85 | 2101 | */ |
43ff2122 | 2102 | static int |
26f1fe85 | 2103 | xfs_buf_delwri_submit_buffers( |
43ff2122 | 2104 | struct list_head *buffer_list, |
26f1fe85 | 2105 | struct list_head *wait_list) |
1da177e4 | 2106 | { |
43ff2122 CH |
2107 | struct xfs_buf *bp, *n; |
2108 | int pinned = 0; | |
26f1fe85 | 2109 | struct blk_plug plug; |
43ff2122 | 2110 | |
26f1fe85 | 2111 | list_sort(NULL, buffer_list, xfs_buf_cmp); |
43ff2122 | 2112 | |
26f1fe85 | 2113 | blk_start_plug(&plug); |
43ff2122 | 2114 | list_for_each_entry_safe(bp, n, buffer_list, b_list) { |
26f1fe85 | 2115 | if (!wait_list) { |
dbd0f529 DC |
2116 | if (!xfs_buf_trylock(bp)) |
2117 | continue; | |
43ff2122 | 2118 | if (xfs_buf_ispinned(bp)) { |
dbd0f529 | 2119 | xfs_buf_unlock(bp); |
43ff2122 CH |
2120 | pinned++; |
2121 | continue; | |
2122 | } | |
43ff2122 CH |
2123 | } else { |
2124 | xfs_buf_lock(bp); | |
2125 | } | |
978c7b2f | 2126 | |
43ff2122 CH |
2127 | /* |
2128 | * Someone else might have written the buffer synchronously or | |
2129 | * marked it stale in the meantime. In that case only the | |
2130 | * _XBF_DELWRI_Q flag got cleared, and we have to drop the | |
2131 | * reference and remove it from the list here. | |
2132 | */ | |
2133 | if (!(bp->b_flags & _XBF_DELWRI_Q)) { | |
2134 | list_del_init(&bp->b_list); | |
2135 | xfs_buf_relse(bp); | |
2136 | continue; | |
2137 | } | |
c9c12971 | 2138 | |
43ff2122 | 2139 | trace_xfs_buf_delwri_split(bp, _RET_IP_); |
a1b7ea5d | 2140 | |
cf53e99d | 2141 | /* |
e339dd8d BF |
2142 | * If we have a wait list, each buffer (and associated delwri |
2143 | * queue reference) transfers to it and is submitted | |
2144 | * synchronously. Otherwise, drop the buffer from the delwri | |
2145 | * queue and submit async. | |
cf53e99d | 2146 | */ |
b6983e80 | 2147 | bp->b_flags &= ~_XBF_DELWRI_Q; |
e339dd8d | 2148 | bp->b_flags |= XBF_WRITE; |
26f1fe85 | 2149 | if (wait_list) { |
e339dd8d | 2150 | bp->b_flags &= ~XBF_ASYNC; |
26f1fe85 | 2151 | list_move_tail(&bp->b_list, wait_list); |
e339dd8d BF |
2152 | } else { |
2153 | bp->b_flags |= XBF_ASYNC; | |
ce8e922c | 2154 | list_del_init(&bp->b_list); |
e339dd8d | 2155 | } |
6af88cda | 2156 | __xfs_buf_submit(bp, false); |
43ff2122 CH |
2157 | } |
2158 | blk_finish_plug(&plug); | |
1da177e4 | 2159 | |
43ff2122 | 2160 | return pinned; |
1da177e4 LT |
2161 | } |
2162 | ||
2163 | /* | |
43ff2122 CH |
2164 | * Write out a buffer list asynchronously. |
2165 | * | |
2166 | * This will take the @buffer_list, write all non-locked and non-pinned buffers | |
2167 | * out and not wait for I/O completion on any of the buffers. This interface | |
2168 | * is only safely useable for callers that can track I/O completion by higher | |
2169 | * level means, e.g. AIL pushing as the @buffer_list is consumed in this | |
2170 | * function. | |
efc3289c BF |
2171 | * |
2172 | * Note: this function will skip buffers it would block on, and in doing so | |
2173 | * leaves them on @buffer_list so they can be retried on a later pass. As such, | |
2174 | * it is up to the caller to ensure that the buffer list is fully submitted or | |
2175 | * cancelled appropriately when they are finished with the list. Failure to | |
2176 | * cancel or resubmit the list until it is empty will result in leaked buffers | |
2177 | * at unmount time. | |
1da177e4 LT |
2178 | */ |
2179 | int | |
43ff2122 CH |
2180 | xfs_buf_delwri_submit_nowait( |
2181 | struct list_head *buffer_list) | |
1da177e4 | 2182 | { |
26f1fe85 | 2183 | return xfs_buf_delwri_submit_buffers(buffer_list, NULL); |
43ff2122 | 2184 | } |
1da177e4 | 2185 | |
43ff2122 CH |
2186 | /* |
2187 | * Write out a buffer list synchronously. | |
2188 | * | |
2189 | * This will take the @buffer_list, write all buffers out and wait for I/O | |
2190 | * completion on all of the buffers. @buffer_list is consumed by the function, | |
2191 | * so callers must have some other way of tracking buffers if they require such | |
2192 | * functionality. | |
2193 | */ | |
2194 | int | |
2195 | xfs_buf_delwri_submit( | |
2196 | struct list_head *buffer_list) | |
2197 | { | |
26f1fe85 | 2198 | LIST_HEAD (wait_list); |
43ff2122 CH |
2199 | int error = 0, error2; |
2200 | struct xfs_buf *bp; | |
1da177e4 | 2201 | |
26f1fe85 | 2202 | xfs_buf_delwri_submit_buffers(buffer_list, &wait_list); |
1da177e4 | 2203 | |
43ff2122 | 2204 | /* Wait for IO to complete. */ |
26f1fe85 DC |
2205 | while (!list_empty(&wait_list)) { |
2206 | bp = list_first_entry(&wait_list, struct xfs_buf, b_list); | |
a1b7ea5d | 2207 | |
089716aa | 2208 | list_del_init(&bp->b_list); |
cf53e99d | 2209 | |
e339dd8d BF |
2210 | /* |
2211 | * Wait on the locked buffer, check for errors and unlock and | |
2212 | * release the delwri queue reference. | |
2213 | */ | |
2214 | error2 = xfs_buf_iowait(bp); | |
43ff2122 CH |
2215 | xfs_buf_relse(bp); |
2216 | if (!error) | |
2217 | error = error2; | |
1da177e4 LT |
2218 | } |
2219 | ||
43ff2122 | 2220 | return error; |
1da177e4 LT |
2221 | } |
2222 | ||
7912e7fe BF |
2223 | /* |
2224 | * Push a single buffer on a delwri queue. | |
2225 | * | |
2226 | * The purpose of this function is to submit a single buffer of a delwri queue | |
2227 | * and return with the buffer still on the original queue. The waiting delwri | |
2228 | * buffer submission infrastructure guarantees transfer of the delwri queue | |
2229 | * buffer reference to a temporary wait list. We reuse this infrastructure to | |
2230 | * transfer the buffer back to the original queue. | |
2231 | * | |
2232 | * Note the buffer transitions from the queued state, to the submitted and wait | |
2233 | * listed state and back to the queued state during this call. The buffer | |
2234 | * locking and queue management logic between _delwri_pushbuf() and | |
2235 | * _delwri_queue() guarantee that the buffer cannot be queued to another list | |
2236 | * before returning. | |
2237 | */ | |
2238 | int | |
2239 | xfs_buf_delwri_pushbuf( | |
2240 | struct xfs_buf *bp, | |
2241 | struct list_head *buffer_list) | |
2242 | { | |
2243 | LIST_HEAD (submit_list); | |
2244 | int error; | |
2245 | ||
2246 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
2247 | ||
2248 | trace_xfs_buf_delwri_pushbuf(bp, _RET_IP_); | |
2249 | ||
2250 | /* | |
2251 | * Isolate the buffer to a new local list so we can submit it for I/O | |
2252 | * independently from the rest of the original list. | |
2253 | */ | |
2254 | xfs_buf_lock(bp); | |
2255 | list_move(&bp->b_list, &submit_list); | |
2256 | xfs_buf_unlock(bp); | |
2257 | ||
2258 | /* | |
2259 | * Delwri submission clears the DELWRI_Q buffer flag and returns with | |
e339dd8d | 2260 | * the buffer on the wait list with the original reference. Rather than |
7912e7fe BF |
2261 | * bounce the buffer from a local wait list back to the original list |
2262 | * after I/O completion, reuse the original list as the wait list. | |
2263 | */ | |
2264 | xfs_buf_delwri_submit_buffers(&submit_list, buffer_list); | |
2265 | ||
2266 | /* | |
e339dd8d BF |
2267 | * The buffer is now locked, under I/O and wait listed on the original |
2268 | * delwri queue. Wait for I/O completion, restore the DELWRI_Q flag and | |
2269 | * return with the buffer unlocked and on the original queue. | |
7912e7fe | 2270 | */ |
e339dd8d | 2271 | error = xfs_buf_iowait(bp); |
7912e7fe BF |
2272 | bp->b_flags |= _XBF_DELWRI_Q; |
2273 | xfs_buf_unlock(bp); | |
2274 | ||
2275 | return error; | |
2276 | } | |
2277 | ||
04d8b284 | 2278 | int __init |
ce8e922c | 2279 | xfs_buf_init(void) |
1da177e4 | 2280 | { |
182696fb | 2281 | xfs_buf_cache = kmem_cache_create("xfs_buf", sizeof(struct xfs_buf), 0, |
12eba65b DC |
2282 | SLAB_HWCACHE_ALIGN | |
2283 | SLAB_RECLAIM_ACCOUNT | | |
2284 | SLAB_MEM_SPREAD, | |
2285 | NULL); | |
182696fb | 2286 | if (!xfs_buf_cache) |
0b1b213f | 2287 | goto out; |
04d8b284 | 2288 | |
23ea4032 | 2289 | return 0; |
1da177e4 | 2290 | |
0b1b213f | 2291 | out: |
8758280f | 2292 | return -ENOMEM; |
1da177e4 LT |
2293 | } |
2294 | ||
1da177e4 | 2295 | void |
ce8e922c | 2296 | xfs_buf_terminate(void) |
1da177e4 | 2297 | { |
182696fb | 2298 | kmem_cache_destroy(xfs_buf_cache); |
1da177e4 | 2299 | } |
7561d27e BF |
2300 | |
2301 | void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref) | |
2302 | { | |
7561d27e BF |
2303 | /* |
2304 | * Set the lru reference count to 0 based on the error injection tag. | |
2305 | * This allows userspace to disrupt buffer caching for debug/testing | |
2306 | * purposes. | |
2307 | */ | |
dbd329f1 | 2308 | if (XFS_TEST_ERROR(false, bp->b_mount, XFS_ERRTAG_BUF_LRU_REF)) |
7561d27e BF |
2309 | lru_ref = 0; |
2310 | ||
2311 | atomic_set(&bp->b_lru_ref, lru_ref); | |
2312 | } | |
8473fee3 BF |
2313 | |
2314 | /* | |
2315 | * Verify an on-disk magic value against the magic value specified in the | |
2316 | * verifier structure. The verifier magic is in disk byte order so the caller is | |
2317 | * expected to pass the value directly from disk. | |
2318 | */ | |
2319 | bool | |
2320 | xfs_verify_magic( | |
2321 | struct xfs_buf *bp, | |
15baadf7 | 2322 | __be32 dmagic) |
8473fee3 | 2323 | { |
dbd329f1 | 2324 | struct xfs_mount *mp = bp->b_mount; |
8473fee3 BF |
2325 | int idx; |
2326 | ||
38c26bfd | 2327 | idx = xfs_has_crc(mp); |
14ed8688 | 2328 | if (WARN_ON(!bp->b_ops || !bp->b_ops->magic[idx])) |
8473fee3 BF |
2329 | return false; |
2330 | return dmagic == bp->b_ops->magic[idx]; | |
2331 | } | |
15baadf7 DW |
2332 | /* |
2333 | * Verify an on-disk magic value against the magic value specified in the | |
2334 | * verifier structure. The verifier magic is in disk byte order so the caller is | |
2335 | * expected to pass the value directly from disk. | |
2336 | */ | |
2337 | bool | |
2338 | xfs_verify_magic16( | |
2339 | struct xfs_buf *bp, | |
2340 | __be16 dmagic) | |
2341 | { | |
dbd329f1 | 2342 | struct xfs_mount *mp = bp->b_mount; |
15baadf7 DW |
2343 | int idx; |
2344 | ||
38c26bfd | 2345 | idx = xfs_has_crc(mp); |
14ed8688 | 2346 | if (WARN_ON(!bp->b_ops || !bp->b_ops->magic16[idx])) |
15baadf7 DW |
2347 | return false; |
2348 | return dmagic == bp->b_ops->magic16[idx]; | |
2349 | } |