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Commit | Line | Data |
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1da177e4 | 1 | /* |
f07c2250 | 2 | * Copyright (c) 2000-2006 Silicon Graphics, Inc. |
7b718769 | 3 | * All Rights Reserved. |
1da177e4 | 4 | * |
7b718769 NS |
5 | * This program is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU General Public License as | |
1da177e4 LT |
7 | * published by the Free Software Foundation. |
8 | * | |
7b718769 NS |
9 | * This program is distributed in the hope that it would be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
1da177e4 | 13 | * |
7b718769 NS |
14 | * You should have received a copy of the GNU General Public License |
15 | * along with this program; if not, write the Free Software Foundation, | |
16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
1da177e4 | 17 | */ |
93c189c1 | 18 | #include "xfs.h" |
1da177e4 LT |
19 | #include <linux/stddef.h> |
20 | #include <linux/errno.h> | |
5a0e3ad6 | 21 | #include <linux/gfp.h> |
1da177e4 LT |
22 | #include <linux/pagemap.h> |
23 | #include <linux/init.h> | |
24 | #include <linux/vmalloc.h> | |
25 | #include <linux/bio.h> | |
26 | #include <linux/sysctl.h> | |
27 | #include <linux/proc_fs.h> | |
28 | #include <linux/workqueue.h> | |
29 | #include <linux/percpu.h> | |
30 | #include <linux/blkdev.h> | |
31 | #include <linux/hash.h> | |
4df08c52 | 32 | #include <linux/kthread.h> |
b20a3503 | 33 | #include <linux/migrate.h> |
3fcfab16 | 34 | #include <linux/backing-dev.h> |
7dfb7103 | 35 | #include <linux/freezer.h> |
1da177e4 | 36 | |
4fb6e8ad | 37 | #include "xfs_format.h" |
239880ef | 38 | #include "xfs_log_format.h" |
7fd36c44 | 39 | #include "xfs_trans_resv.h" |
239880ef | 40 | #include "xfs_sb.h" |
b7963133 | 41 | #include "xfs_mount.h" |
0b1b213f | 42 | #include "xfs_trace.h" |
239880ef | 43 | #include "xfs_log.h" |
b7963133 | 44 | |
7989cb8e | 45 | static kmem_zone_t *xfs_buf_zone; |
23ea4032 | 46 | |
ce8e922c NS |
47 | #ifdef XFS_BUF_LOCK_TRACKING |
48 | # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid) | |
49 | # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1) | |
50 | # define XB_GET_OWNER(bp) ((bp)->b_last_holder) | |
1da177e4 | 51 | #else |
ce8e922c NS |
52 | # define XB_SET_OWNER(bp) do { } while (0) |
53 | # define XB_CLEAR_OWNER(bp) do { } while (0) | |
54 | # define XB_GET_OWNER(bp) do { } while (0) | |
1da177e4 LT |
55 | #endif |
56 | ||
ce8e922c | 57 | #define xb_to_gfp(flags) \ |
aa5c158e | 58 | ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : GFP_NOFS) | __GFP_NOWARN) |
1da177e4 | 59 | |
1da177e4 | 60 | |
73c77e2c JB |
61 | static inline int |
62 | xfs_buf_is_vmapped( | |
63 | struct xfs_buf *bp) | |
64 | { | |
65 | /* | |
66 | * Return true if the buffer is vmapped. | |
67 | * | |
611c9946 DC |
68 | * b_addr is null if the buffer is not mapped, but the code is clever |
69 | * enough to know it doesn't have to map a single page, so the check has | |
70 | * to be both for b_addr and bp->b_page_count > 1. | |
73c77e2c | 71 | */ |
611c9946 | 72 | return bp->b_addr && bp->b_page_count > 1; |
73c77e2c JB |
73 | } |
74 | ||
75 | static inline int | |
76 | xfs_buf_vmap_len( | |
77 | struct xfs_buf *bp) | |
78 | { | |
79 | return (bp->b_page_count * PAGE_SIZE) - bp->b_offset; | |
80 | } | |
81 | ||
430cbeb8 DC |
82 | /* |
83 | * When we mark a buffer stale, we remove the buffer from the LRU and clear the | |
84 | * b_lru_ref count so that the buffer is freed immediately when the buffer | |
85 | * reference count falls to zero. If the buffer is already on the LRU, we need | |
86 | * to remove the reference that LRU holds on the buffer. | |
87 | * | |
88 | * This prevents build-up of stale buffers on the LRU. | |
89 | */ | |
90 | void | |
91 | xfs_buf_stale( | |
92 | struct xfs_buf *bp) | |
93 | { | |
43ff2122 CH |
94 | ASSERT(xfs_buf_islocked(bp)); |
95 | ||
430cbeb8 | 96 | bp->b_flags |= XBF_STALE; |
43ff2122 CH |
97 | |
98 | /* | |
99 | * Clear the delwri status so that a delwri queue walker will not | |
100 | * flush this buffer to disk now that it is stale. The delwri queue has | |
101 | * a reference to the buffer, so this is safe to do. | |
102 | */ | |
103 | bp->b_flags &= ~_XBF_DELWRI_Q; | |
104 | ||
a4082357 DC |
105 | spin_lock(&bp->b_lock); |
106 | atomic_set(&bp->b_lru_ref, 0); | |
107 | if (!(bp->b_state & XFS_BSTATE_DISPOSE) && | |
e80dfa19 DC |
108 | (list_lru_del(&bp->b_target->bt_lru, &bp->b_lru))) |
109 | atomic_dec(&bp->b_hold); | |
110 | ||
430cbeb8 | 111 | ASSERT(atomic_read(&bp->b_hold) >= 1); |
a4082357 | 112 | spin_unlock(&bp->b_lock); |
430cbeb8 | 113 | } |
1da177e4 | 114 | |
3e85c868 DC |
115 | static int |
116 | xfs_buf_get_maps( | |
117 | struct xfs_buf *bp, | |
118 | int map_count) | |
119 | { | |
120 | ASSERT(bp->b_maps == NULL); | |
121 | bp->b_map_count = map_count; | |
122 | ||
123 | if (map_count == 1) { | |
f4b42421 | 124 | bp->b_maps = &bp->__b_map; |
3e85c868 DC |
125 | return 0; |
126 | } | |
127 | ||
128 | bp->b_maps = kmem_zalloc(map_count * sizeof(struct xfs_buf_map), | |
129 | KM_NOFS); | |
130 | if (!bp->b_maps) | |
2451337d | 131 | return -ENOMEM; |
3e85c868 DC |
132 | return 0; |
133 | } | |
134 | ||
135 | /* | |
136 | * Frees b_pages if it was allocated. | |
137 | */ | |
138 | static void | |
139 | xfs_buf_free_maps( | |
140 | struct xfs_buf *bp) | |
141 | { | |
f4b42421 | 142 | if (bp->b_maps != &bp->__b_map) { |
3e85c868 DC |
143 | kmem_free(bp->b_maps); |
144 | bp->b_maps = NULL; | |
145 | } | |
146 | } | |
147 | ||
4347b9d7 | 148 | struct xfs_buf * |
3e85c868 | 149 | _xfs_buf_alloc( |
4347b9d7 | 150 | struct xfs_buftarg *target, |
3e85c868 DC |
151 | struct xfs_buf_map *map, |
152 | int nmaps, | |
ce8e922c | 153 | xfs_buf_flags_t flags) |
1da177e4 | 154 | { |
4347b9d7 | 155 | struct xfs_buf *bp; |
3e85c868 DC |
156 | int error; |
157 | int i; | |
4347b9d7 | 158 | |
aa5c158e | 159 | bp = kmem_zone_zalloc(xfs_buf_zone, KM_NOFS); |
4347b9d7 CH |
160 | if (unlikely(!bp)) |
161 | return NULL; | |
162 | ||
1da177e4 | 163 | /* |
12bcb3f7 DC |
164 | * We don't want certain flags to appear in b_flags unless they are |
165 | * specifically set by later operations on the buffer. | |
1da177e4 | 166 | */ |
611c9946 | 167 | flags &= ~(XBF_UNMAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD); |
ce8e922c | 168 | |
ce8e922c | 169 | atomic_set(&bp->b_hold, 1); |
430cbeb8 | 170 | atomic_set(&bp->b_lru_ref, 1); |
b4dd330b | 171 | init_completion(&bp->b_iowait); |
430cbeb8 | 172 | INIT_LIST_HEAD(&bp->b_lru); |
ce8e922c | 173 | INIT_LIST_HEAD(&bp->b_list); |
74f75a0c | 174 | RB_CLEAR_NODE(&bp->b_rbnode); |
a731cd11 | 175 | sema_init(&bp->b_sema, 0); /* held, no waiters */ |
a4082357 | 176 | spin_lock_init(&bp->b_lock); |
ce8e922c NS |
177 | XB_SET_OWNER(bp); |
178 | bp->b_target = target; | |
3e85c868 | 179 | bp->b_flags = flags; |
de1cbee4 | 180 | |
1da177e4 | 181 | /* |
aa0e8833 DC |
182 | * Set length and io_length to the same value initially. |
183 | * I/O routines should use io_length, which will be the same in | |
1da177e4 LT |
184 | * most cases but may be reset (e.g. XFS recovery). |
185 | */ | |
3e85c868 DC |
186 | error = xfs_buf_get_maps(bp, nmaps); |
187 | if (error) { | |
188 | kmem_zone_free(xfs_buf_zone, bp); | |
189 | return NULL; | |
190 | } | |
191 | ||
192 | bp->b_bn = map[0].bm_bn; | |
193 | bp->b_length = 0; | |
194 | for (i = 0; i < nmaps; i++) { | |
195 | bp->b_maps[i].bm_bn = map[i].bm_bn; | |
196 | bp->b_maps[i].bm_len = map[i].bm_len; | |
197 | bp->b_length += map[i].bm_len; | |
198 | } | |
199 | bp->b_io_length = bp->b_length; | |
200 | ||
ce8e922c NS |
201 | atomic_set(&bp->b_pin_count, 0); |
202 | init_waitqueue_head(&bp->b_waiters); | |
203 | ||
204 | XFS_STATS_INC(xb_create); | |
0b1b213f | 205 | trace_xfs_buf_init(bp, _RET_IP_); |
4347b9d7 CH |
206 | |
207 | return bp; | |
1da177e4 LT |
208 | } |
209 | ||
210 | /* | |
ce8e922c NS |
211 | * Allocate a page array capable of holding a specified number |
212 | * of pages, and point the page buf at it. | |
1da177e4 LT |
213 | */ |
214 | STATIC int | |
ce8e922c NS |
215 | _xfs_buf_get_pages( |
216 | xfs_buf_t *bp, | |
87937bf8 | 217 | int page_count) |
1da177e4 LT |
218 | { |
219 | /* Make sure that we have a page list */ | |
ce8e922c | 220 | if (bp->b_pages == NULL) { |
ce8e922c NS |
221 | bp->b_page_count = page_count; |
222 | if (page_count <= XB_PAGES) { | |
223 | bp->b_pages = bp->b_page_array; | |
1da177e4 | 224 | } else { |
ce8e922c | 225 | bp->b_pages = kmem_alloc(sizeof(struct page *) * |
aa5c158e | 226 | page_count, KM_NOFS); |
ce8e922c | 227 | if (bp->b_pages == NULL) |
1da177e4 LT |
228 | return -ENOMEM; |
229 | } | |
ce8e922c | 230 | memset(bp->b_pages, 0, sizeof(struct page *) * page_count); |
1da177e4 LT |
231 | } |
232 | return 0; | |
233 | } | |
234 | ||
235 | /* | |
ce8e922c | 236 | * Frees b_pages if it was allocated. |
1da177e4 LT |
237 | */ |
238 | STATIC void | |
ce8e922c | 239 | _xfs_buf_free_pages( |
1da177e4 LT |
240 | xfs_buf_t *bp) |
241 | { | |
ce8e922c | 242 | if (bp->b_pages != bp->b_page_array) { |
f0e2d93c | 243 | kmem_free(bp->b_pages); |
3fc98b1a | 244 | bp->b_pages = NULL; |
1da177e4 LT |
245 | } |
246 | } | |
247 | ||
248 | /* | |
249 | * Releases the specified buffer. | |
250 | * | |
251 | * The modification state of any associated pages is left unchanged. | |
b46fe825 | 252 | * The buffer must not be on any hash - use xfs_buf_rele instead for |
1da177e4 LT |
253 | * hashed and refcounted buffers |
254 | */ | |
255 | void | |
ce8e922c | 256 | xfs_buf_free( |
1da177e4 LT |
257 | xfs_buf_t *bp) |
258 | { | |
0b1b213f | 259 | trace_xfs_buf_free(bp, _RET_IP_); |
1da177e4 | 260 | |
430cbeb8 DC |
261 | ASSERT(list_empty(&bp->b_lru)); |
262 | ||
0e6e847f | 263 | if (bp->b_flags & _XBF_PAGES) { |
1da177e4 LT |
264 | uint i; |
265 | ||
73c77e2c | 266 | if (xfs_buf_is_vmapped(bp)) |
8a262e57 AE |
267 | vm_unmap_ram(bp->b_addr - bp->b_offset, |
268 | bp->b_page_count); | |
1da177e4 | 269 | |
948ecdb4 NS |
270 | for (i = 0; i < bp->b_page_count; i++) { |
271 | struct page *page = bp->b_pages[i]; | |
272 | ||
0e6e847f | 273 | __free_page(page); |
948ecdb4 | 274 | } |
0e6e847f DC |
275 | } else if (bp->b_flags & _XBF_KMEM) |
276 | kmem_free(bp->b_addr); | |
3fc98b1a | 277 | _xfs_buf_free_pages(bp); |
3e85c868 | 278 | xfs_buf_free_maps(bp); |
4347b9d7 | 279 | kmem_zone_free(xfs_buf_zone, bp); |
1da177e4 LT |
280 | } |
281 | ||
282 | /* | |
0e6e847f | 283 | * Allocates all the pages for buffer in question and builds it's page list. |
1da177e4 LT |
284 | */ |
285 | STATIC int | |
0e6e847f | 286 | xfs_buf_allocate_memory( |
1da177e4 LT |
287 | xfs_buf_t *bp, |
288 | uint flags) | |
289 | { | |
aa0e8833 | 290 | size_t size; |
1da177e4 | 291 | size_t nbytes, offset; |
ce8e922c | 292 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 | 293 | unsigned short page_count, i; |
795cac72 | 294 | xfs_off_t start, end; |
1da177e4 LT |
295 | int error; |
296 | ||
0e6e847f DC |
297 | /* |
298 | * for buffers that are contained within a single page, just allocate | |
299 | * the memory from the heap - there's no need for the complexity of | |
300 | * page arrays to keep allocation down to order 0. | |
301 | */ | |
795cac72 DC |
302 | size = BBTOB(bp->b_length); |
303 | if (size < PAGE_SIZE) { | |
aa5c158e | 304 | bp->b_addr = kmem_alloc(size, KM_NOFS); |
0e6e847f DC |
305 | if (!bp->b_addr) { |
306 | /* low memory - use alloc_page loop instead */ | |
307 | goto use_alloc_page; | |
308 | } | |
309 | ||
795cac72 | 310 | if (((unsigned long)(bp->b_addr + size - 1) & PAGE_MASK) != |
0e6e847f DC |
311 | ((unsigned long)bp->b_addr & PAGE_MASK)) { |
312 | /* b_addr spans two pages - use alloc_page instead */ | |
313 | kmem_free(bp->b_addr); | |
314 | bp->b_addr = NULL; | |
315 | goto use_alloc_page; | |
316 | } | |
317 | bp->b_offset = offset_in_page(bp->b_addr); | |
318 | bp->b_pages = bp->b_page_array; | |
319 | bp->b_pages[0] = virt_to_page(bp->b_addr); | |
320 | bp->b_page_count = 1; | |
611c9946 | 321 | bp->b_flags |= _XBF_KMEM; |
0e6e847f DC |
322 | return 0; |
323 | } | |
324 | ||
325 | use_alloc_page: | |
f4b42421 MT |
326 | start = BBTOB(bp->b_maps[0].bm_bn) >> PAGE_SHIFT; |
327 | end = (BBTOB(bp->b_maps[0].bm_bn + bp->b_length) + PAGE_SIZE - 1) | |
cbb7baab | 328 | >> PAGE_SHIFT; |
795cac72 | 329 | page_count = end - start; |
87937bf8 | 330 | error = _xfs_buf_get_pages(bp, page_count); |
1da177e4 LT |
331 | if (unlikely(error)) |
332 | return error; | |
1da177e4 | 333 | |
ce8e922c | 334 | offset = bp->b_offset; |
0e6e847f | 335 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 336 | |
ce8e922c | 337 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
338 | struct page *page; |
339 | uint retries = 0; | |
0e6e847f DC |
340 | retry: |
341 | page = alloc_page(gfp_mask); | |
1da177e4 | 342 | if (unlikely(page == NULL)) { |
ce8e922c NS |
343 | if (flags & XBF_READ_AHEAD) { |
344 | bp->b_page_count = i; | |
2451337d | 345 | error = -ENOMEM; |
0e6e847f | 346 | goto out_free_pages; |
1da177e4 LT |
347 | } |
348 | ||
349 | /* | |
350 | * This could deadlock. | |
351 | * | |
352 | * But until all the XFS lowlevel code is revamped to | |
353 | * handle buffer allocation failures we can't do much. | |
354 | */ | |
355 | if (!(++retries % 100)) | |
4f10700a DC |
356 | xfs_err(NULL, |
357 | "possible memory allocation deadlock in %s (mode:0x%x)", | |
34a622b2 | 358 | __func__, gfp_mask); |
1da177e4 | 359 | |
ce8e922c | 360 | XFS_STATS_INC(xb_page_retries); |
8aa7e847 | 361 | congestion_wait(BLK_RW_ASYNC, HZ/50); |
1da177e4 LT |
362 | goto retry; |
363 | } | |
364 | ||
ce8e922c | 365 | XFS_STATS_INC(xb_page_found); |
1da177e4 | 366 | |
0e6e847f | 367 | nbytes = min_t(size_t, size, PAGE_SIZE - offset); |
1da177e4 | 368 | size -= nbytes; |
ce8e922c | 369 | bp->b_pages[i] = page; |
1da177e4 LT |
370 | offset = 0; |
371 | } | |
0e6e847f | 372 | return 0; |
1da177e4 | 373 | |
0e6e847f DC |
374 | out_free_pages: |
375 | for (i = 0; i < bp->b_page_count; i++) | |
376 | __free_page(bp->b_pages[i]); | |
1da177e4 LT |
377 | return error; |
378 | } | |
379 | ||
380 | /* | |
25985edc | 381 | * Map buffer into kernel address-space if necessary. |
1da177e4 LT |
382 | */ |
383 | STATIC int | |
ce8e922c | 384 | _xfs_buf_map_pages( |
1da177e4 LT |
385 | xfs_buf_t *bp, |
386 | uint flags) | |
387 | { | |
0e6e847f | 388 | ASSERT(bp->b_flags & _XBF_PAGES); |
ce8e922c | 389 | if (bp->b_page_count == 1) { |
0e6e847f | 390 | /* A single page buffer is always mappable */ |
ce8e922c | 391 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; |
611c9946 DC |
392 | } else if (flags & XBF_UNMAPPED) { |
393 | bp->b_addr = NULL; | |
394 | } else { | |
a19fb380 | 395 | int retried = 0; |
ae687e58 DC |
396 | unsigned noio_flag; |
397 | ||
398 | /* | |
399 | * vm_map_ram() will allocate auxillary structures (e.g. | |
400 | * pagetables) with GFP_KERNEL, yet we are likely to be under | |
401 | * GFP_NOFS context here. Hence we need to tell memory reclaim | |
402 | * that we are in such a context via PF_MEMALLOC_NOIO to prevent | |
403 | * memory reclaim re-entering the filesystem here and | |
404 | * potentially deadlocking. | |
405 | */ | |
406 | noio_flag = memalloc_noio_save(); | |
a19fb380 DC |
407 | do { |
408 | bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, | |
409 | -1, PAGE_KERNEL); | |
410 | if (bp->b_addr) | |
411 | break; | |
412 | vm_unmap_aliases(); | |
413 | } while (retried++ <= 1); | |
ae687e58 | 414 | memalloc_noio_restore(noio_flag); |
a19fb380 DC |
415 | |
416 | if (!bp->b_addr) | |
1da177e4 | 417 | return -ENOMEM; |
ce8e922c | 418 | bp->b_addr += bp->b_offset; |
1da177e4 LT |
419 | } |
420 | ||
421 | return 0; | |
422 | } | |
423 | ||
424 | /* | |
425 | * Finding and Reading Buffers | |
426 | */ | |
427 | ||
428 | /* | |
ce8e922c | 429 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 | 430 | * a given range of an inode. The buffer is returned |
eabbaf11 | 431 | * locked. No I/O is implied by this call. |
1da177e4 LT |
432 | */ |
433 | xfs_buf_t * | |
ce8e922c | 434 | _xfs_buf_find( |
e70b73f8 | 435 | struct xfs_buftarg *btp, |
3e85c868 DC |
436 | struct xfs_buf_map *map, |
437 | int nmaps, | |
ce8e922c NS |
438 | xfs_buf_flags_t flags, |
439 | xfs_buf_t *new_bp) | |
1da177e4 | 440 | { |
e70b73f8 | 441 | size_t numbytes; |
74f75a0c DC |
442 | struct xfs_perag *pag; |
443 | struct rb_node **rbp; | |
444 | struct rb_node *parent; | |
445 | xfs_buf_t *bp; | |
3e85c868 | 446 | xfs_daddr_t blkno = map[0].bm_bn; |
10616b80 | 447 | xfs_daddr_t eofs; |
3e85c868 DC |
448 | int numblks = 0; |
449 | int i; | |
1da177e4 | 450 | |
3e85c868 DC |
451 | for (i = 0; i < nmaps; i++) |
452 | numblks += map[i].bm_len; | |
e70b73f8 | 453 | numbytes = BBTOB(numblks); |
1da177e4 LT |
454 | |
455 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
6da54179 ES |
456 | ASSERT(!(numbytes < btp->bt_meta_sectorsize)); |
457 | ASSERT(!(BBTOB(blkno) & (xfs_off_t)btp->bt_meta_sectormask)); | |
1da177e4 | 458 | |
10616b80 DC |
459 | /* |
460 | * Corrupted block numbers can get through to here, unfortunately, so we | |
461 | * have to check that the buffer falls within the filesystem bounds. | |
462 | */ | |
463 | eofs = XFS_FSB_TO_BB(btp->bt_mount, btp->bt_mount->m_sb.sb_dblocks); | |
db52d09e | 464 | if (blkno < 0 || blkno >= eofs) { |
10616b80 | 465 | /* |
2451337d | 466 | * XXX (dgc): we should really be returning -EFSCORRUPTED here, |
10616b80 DC |
467 | * but none of the higher level infrastructure supports |
468 | * returning a specific error on buffer lookup failures. | |
469 | */ | |
470 | xfs_alert(btp->bt_mount, | |
471 | "%s: Block out of range: block 0x%llx, EOFS 0x%llx ", | |
472 | __func__, blkno, eofs); | |
7bc0dc27 | 473 | WARN_ON(1); |
10616b80 DC |
474 | return NULL; |
475 | } | |
476 | ||
74f75a0c DC |
477 | /* get tree root */ |
478 | pag = xfs_perag_get(btp->bt_mount, | |
e70b73f8 | 479 | xfs_daddr_to_agno(btp->bt_mount, blkno)); |
74f75a0c DC |
480 | |
481 | /* walk tree */ | |
482 | spin_lock(&pag->pag_buf_lock); | |
483 | rbp = &pag->pag_buf_tree.rb_node; | |
484 | parent = NULL; | |
485 | bp = NULL; | |
486 | while (*rbp) { | |
487 | parent = *rbp; | |
488 | bp = rb_entry(parent, struct xfs_buf, b_rbnode); | |
489 | ||
de1cbee4 | 490 | if (blkno < bp->b_bn) |
74f75a0c | 491 | rbp = &(*rbp)->rb_left; |
de1cbee4 | 492 | else if (blkno > bp->b_bn) |
74f75a0c DC |
493 | rbp = &(*rbp)->rb_right; |
494 | else { | |
495 | /* | |
de1cbee4 | 496 | * found a block number match. If the range doesn't |
74f75a0c DC |
497 | * match, the only way this is allowed is if the buffer |
498 | * in the cache is stale and the transaction that made | |
499 | * it stale has not yet committed. i.e. we are | |
500 | * reallocating a busy extent. Skip this buffer and | |
501 | * continue searching to the right for an exact match. | |
502 | */ | |
4e94b71b | 503 | if (bp->b_length != numblks) { |
74f75a0c DC |
504 | ASSERT(bp->b_flags & XBF_STALE); |
505 | rbp = &(*rbp)->rb_right; | |
506 | continue; | |
507 | } | |
ce8e922c | 508 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
509 | goto found; |
510 | } | |
511 | } | |
512 | ||
513 | /* No match found */ | |
ce8e922c | 514 | if (new_bp) { |
74f75a0c DC |
515 | rb_link_node(&new_bp->b_rbnode, parent, rbp); |
516 | rb_insert_color(&new_bp->b_rbnode, &pag->pag_buf_tree); | |
517 | /* the buffer keeps the perag reference until it is freed */ | |
518 | new_bp->b_pag = pag; | |
519 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 520 | } else { |
ce8e922c | 521 | XFS_STATS_INC(xb_miss_locked); |
74f75a0c DC |
522 | spin_unlock(&pag->pag_buf_lock); |
523 | xfs_perag_put(pag); | |
1da177e4 | 524 | } |
ce8e922c | 525 | return new_bp; |
1da177e4 LT |
526 | |
527 | found: | |
74f75a0c DC |
528 | spin_unlock(&pag->pag_buf_lock); |
529 | xfs_perag_put(pag); | |
1da177e4 | 530 | |
0c842ad4 CH |
531 | if (!xfs_buf_trylock(bp)) { |
532 | if (flags & XBF_TRYLOCK) { | |
ce8e922c NS |
533 | xfs_buf_rele(bp); |
534 | XFS_STATS_INC(xb_busy_locked); | |
535 | return NULL; | |
1da177e4 | 536 | } |
0c842ad4 CH |
537 | xfs_buf_lock(bp); |
538 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 LT |
539 | } |
540 | ||
0e6e847f DC |
541 | /* |
542 | * if the buffer is stale, clear all the external state associated with | |
543 | * it. We need to keep flags such as how we allocated the buffer memory | |
544 | * intact here. | |
545 | */ | |
ce8e922c NS |
546 | if (bp->b_flags & XBF_STALE) { |
547 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
cfb02852 | 548 | ASSERT(bp->b_iodone == NULL); |
611c9946 | 549 | bp->b_flags &= _XBF_KMEM | _XBF_PAGES; |
1813dd64 | 550 | bp->b_ops = NULL; |
2f926587 | 551 | } |
0b1b213f CH |
552 | |
553 | trace_xfs_buf_find(bp, flags, _RET_IP_); | |
ce8e922c NS |
554 | XFS_STATS_INC(xb_get_locked); |
555 | return bp; | |
1da177e4 LT |
556 | } |
557 | ||
558 | /* | |
3815832a DC |
559 | * Assembles a buffer covering the specified range. The code is optimised for |
560 | * cache hits, as metadata intensive workloads will see 3 orders of magnitude | |
561 | * more hits than misses. | |
1da177e4 | 562 | */ |
3815832a | 563 | struct xfs_buf * |
6dde2707 DC |
564 | xfs_buf_get_map( |
565 | struct xfs_buftarg *target, | |
566 | struct xfs_buf_map *map, | |
567 | int nmaps, | |
ce8e922c | 568 | xfs_buf_flags_t flags) |
1da177e4 | 569 | { |
3815832a DC |
570 | struct xfs_buf *bp; |
571 | struct xfs_buf *new_bp; | |
0e6e847f | 572 | int error = 0; |
1da177e4 | 573 | |
6dde2707 | 574 | bp = _xfs_buf_find(target, map, nmaps, flags, NULL); |
3815832a DC |
575 | if (likely(bp)) |
576 | goto found; | |
577 | ||
6dde2707 | 578 | new_bp = _xfs_buf_alloc(target, map, nmaps, flags); |
ce8e922c | 579 | if (unlikely(!new_bp)) |
1da177e4 LT |
580 | return NULL; |
581 | ||
fe2429b0 DC |
582 | error = xfs_buf_allocate_memory(new_bp, flags); |
583 | if (error) { | |
3e85c868 | 584 | xfs_buf_free(new_bp); |
fe2429b0 DC |
585 | return NULL; |
586 | } | |
587 | ||
6dde2707 | 588 | bp = _xfs_buf_find(target, map, nmaps, flags, new_bp); |
3815832a | 589 | if (!bp) { |
fe2429b0 | 590 | xfs_buf_free(new_bp); |
3815832a DC |
591 | return NULL; |
592 | } | |
593 | ||
fe2429b0 DC |
594 | if (bp != new_bp) |
595 | xfs_buf_free(new_bp); | |
1da177e4 | 596 | |
3815832a | 597 | found: |
611c9946 | 598 | if (!bp->b_addr) { |
ce8e922c | 599 | error = _xfs_buf_map_pages(bp, flags); |
1da177e4 | 600 | if (unlikely(error)) { |
4f10700a | 601 | xfs_warn(target->bt_mount, |
08e96e1a | 602 | "%s: failed to map pagesn", __func__); |
a8acad70 DC |
603 | xfs_buf_relse(bp); |
604 | return NULL; | |
1da177e4 LT |
605 | } |
606 | } | |
607 | ||
ce8e922c | 608 | XFS_STATS_INC(xb_get); |
0b1b213f | 609 | trace_xfs_buf_get(bp, flags, _RET_IP_); |
ce8e922c | 610 | return bp; |
1da177e4 LT |
611 | } |
612 | ||
5d765b97 CH |
613 | STATIC int |
614 | _xfs_buf_read( | |
615 | xfs_buf_t *bp, | |
616 | xfs_buf_flags_t flags) | |
617 | { | |
43ff2122 | 618 | ASSERT(!(flags & XBF_WRITE)); |
f4b42421 | 619 | ASSERT(bp->b_maps[0].bm_bn != XFS_BUF_DADDR_NULL); |
5d765b97 | 620 | |
43ff2122 | 621 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD); |
1d5ae5df | 622 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD); |
5d765b97 | 623 | |
595bff75 DC |
624 | if (flags & XBF_ASYNC) { |
625 | xfs_buf_submit(bp); | |
0e95f19a | 626 | return 0; |
595bff75 DC |
627 | } |
628 | return xfs_buf_submit_wait(bp); | |
5d765b97 CH |
629 | } |
630 | ||
1da177e4 | 631 | xfs_buf_t * |
6dde2707 DC |
632 | xfs_buf_read_map( |
633 | struct xfs_buftarg *target, | |
634 | struct xfs_buf_map *map, | |
635 | int nmaps, | |
c3f8fc73 | 636 | xfs_buf_flags_t flags, |
1813dd64 | 637 | const struct xfs_buf_ops *ops) |
1da177e4 | 638 | { |
6dde2707 | 639 | struct xfs_buf *bp; |
ce8e922c NS |
640 | |
641 | flags |= XBF_READ; | |
642 | ||
6dde2707 | 643 | bp = xfs_buf_get_map(target, map, nmaps, flags); |
ce8e922c | 644 | if (bp) { |
0b1b213f CH |
645 | trace_xfs_buf_read(bp, flags, _RET_IP_); |
646 | ||
ce8e922c | 647 | if (!XFS_BUF_ISDONE(bp)) { |
ce8e922c | 648 | XFS_STATS_INC(xb_get_read); |
1813dd64 | 649 | bp->b_ops = ops; |
5d765b97 | 650 | _xfs_buf_read(bp, flags); |
ce8e922c | 651 | } else if (flags & XBF_ASYNC) { |
1da177e4 LT |
652 | /* |
653 | * Read ahead call which is already satisfied, | |
654 | * drop the buffer | |
655 | */ | |
a8acad70 DC |
656 | xfs_buf_relse(bp); |
657 | return NULL; | |
1da177e4 | 658 | } else { |
1da177e4 | 659 | /* We do not want read in the flags */ |
ce8e922c | 660 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
661 | } |
662 | } | |
663 | ||
ce8e922c | 664 | return bp; |
1da177e4 LT |
665 | } |
666 | ||
1da177e4 | 667 | /* |
ce8e922c NS |
668 | * If we are not low on memory then do the readahead in a deadlock |
669 | * safe manner. | |
1da177e4 LT |
670 | */ |
671 | void | |
6dde2707 DC |
672 | xfs_buf_readahead_map( |
673 | struct xfs_buftarg *target, | |
674 | struct xfs_buf_map *map, | |
c3f8fc73 | 675 | int nmaps, |
1813dd64 | 676 | const struct xfs_buf_ops *ops) |
1da177e4 | 677 | { |
0e6e847f | 678 | if (bdi_read_congested(target->bt_bdi)) |
1da177e4 LT |
679 | return; |
680 | ||
6dde2707 | 681 | xfs_buf_read_map(target, map, nmaps, |
1813dd64 | 682 | XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD, ops); |
1da177e4 LT |
683 | } |
684 | ||
5adc94c2 DC |
685 | /* |
686 | * Read an uncached buffer from disk. Allocates and returns a locked | |
687 | * buffer containing the disk contents or nothing. | |
688 | */ | |
ba372674 | 689 | int |
5adc94c2 | 690 | xfs_buf_read_uncached( |
5adc94c2 DC |
691 | struct xfs_buftarg *target, |
692 | xfs_daddr_t daddr, | |
e70b73f8 | 693 | size_t numblks, |
c3f8fc73 | 694 | int flags, |
ba372674 | 695 | struct xfs_buf **bpp, |
1813dd64 | 696 | const struct xfs_buf_ops *ops) |
5adc94c2 | 697 | { |
eab4e633 | 698 | struct xfs_buf *bp; |
5adc94c2 | 699 | |
ba372674 DC |
700 | *bpp = NULL; |
701 | ||
e70b73f8 | 702 | bp = xfs_buf_get_uncached(target, numblks, flags); |
5adc94c2 | 703 | if (!bp) |
ba372674 | 704 | return -ENOMEM; |
5adc94c2 DC |
705 | |
706 | /* set up the buffer for a read IO */ | |
3e85c868 | 707 | ASSERT(bp->b_map_count == 1); |
ba372674 | 708 | bp->b_bn = XFS_BUF_DADDR_NULL; /* always null for uncached buffers */ |
3e85c868 | 709 | bp->b_maps[0].bm_bn = daddr; |
cbb7baab | 710 | bp->b_flags |= XBF_READ; |
1813dd64 | 711 | bp->b_ops = ops; |
5adc94c2 | 712 | |
595bff75 | 713 | xfs_buf_submit_wait(bp); |
ba372674 DC |
714 | if (bp->b_error) { |
715 | int error = bp->b_error; | |
83a0adc3 | 716 | xfs_buf_relse(bp); |
ba372674 | 717 | return error; |
83a0adc3 | 718 | } |
ba372674 DC |
719 | |
720 | *bpp = bp; | |
721 | return 0; | |
1da177e4 LT |
722 | } |
723 | ||
44396476 DC |
724 | /* |
725 | * Return a buffer allocated as an empty buffer and associated to external | |
726 | * memory via xfs_buf_associate_memory() back to it's empty state. | |
727 | */ | |
728 | void | |
729 | xfs_buf_set_empty( | |
730 | struct xfs_buf *bp, | |
e70b73f8 | 731 | size_t numblks) |
44396476 DC |
732 | { |
733 | if (bp->b_pages) | |
734 | _xfs_buf_free_pages(bp); | |
735 | ||
736 | bp->b_pages = NULL; | |
737 | bp->b_page_count = 0; | |
738 | bp->b_addr = NULL; | |
4e94b71b | 739 | bp->b_length = numblks; |
aa0e8833 | 740 | bp->b_io_length = numblks; |
3e85c868 DC |
741 | |
742 | ASSERT(bp->b_map_count == 1); | |
44396476 | 743 | bp->b_bn = XFS_BUF_DADDR_NULL; |
3e85c868 DC |
744 | bp->b_maps[0].bm_bn = XFS_BUF_DADDR_NULL; |
745 | bp->b_maps[0].bm_len = bp->b_length; | |
44396476 DC |
746 | } |
747 | ||
1da177e4 LT |
748 | static inline struct page * |
749 | mem_to_page( | |
750 | void *addr) | |
751 | { | |
9e2779fa | 752 | if ((!is_vmalloc_addr(addr))) { |
1da177e4 LT |
753 | return virt_to_page(addr); |
754 | } else { | |
755 | return vmalloc_to_page(addr); | |
756 | } | |
757 | } | |
758 | ||
759 | int | |
ce8e922c NS |
760 | xfs_buf_associate_memory( |
761 | xfs_buf_t *bp, | |
1da177e4 LT |
762 | void *mem, |
763 | size_t len) | |
764 | { | |
765 | int rval; | |
766 | int i = 0; | |
d1afb678 LM |
767 | unsigned long pageaddr; |
768 | unsigned long offset; | |
769 | size_t buflen; | |
1da177e4 LT |
770 | int page_count; |
771 | ||
0e6e847f | 772 | pageaddr = (unsigned long)mem & PAGE_MASK; |
d1afb678 | 773 | offset = (unsigned long)mem - pageaddr; |
0e6e847f DC |
774 | buflen = PAGE_ALIGN(len + offset); |
775 | page_count = buflen >> PAGE_SHIFT; | |
1da177e4 LT |
776 | |
777 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
778 | if (bp->b_pages) |
779 | _xfs_buf_free_pages(bp); | |
1da177e4 | 780 | |
ce8e922c NS |
781 | bp->b_pages = NULL; |
782 | bp->b_addr = mem; | |
1da177e4 | 783 | |
87937bf8 | 784 | rval = _xfs_buf_get_pages(bp, page_count); |
1da177e4 LT |
785 | if (rval) |
786 | return rval; | |
787 | ||
ce8e922c | 788 | bp->b_offset = offset; |
d1afb678 LM |
789 | |
790 | for (i = 0; i < bp->b_page_count; i++) { | |
791 | bp->b_pages[i] = mem_to_page((void *)pageaddr); | |
0e6e847f | 792 | pageaddr += PAGE_SIZE; |
1da177e4 | 793 | } |
1da177e4 | 794 | |
aa0e8833 | 795 | bp->b_io_length = BTOBB(len); |
4e94b71b | 796 | bp->b_length = BTOBB(buflen); |
1da177e4 LT |
797 | |
798 | return 0; | |
799 | } | |
800 | ||
801 | xfs_buf_t * | |
686865f7 DC |
802 | xfs_buf_get_uncached( |
803 | struct xfs_buftarg *target, | |
e70b73f8 | 804 | size_t numblks, |
686865f7 | 805 | int flags) |
1da177e4 | 806 | { |
e70b73f8 | 807 | unsigned long page_count; |
1fa40b01 | 808 | int error, i; |
3e85c868 DC |
809 | struct xfs_buf *bp; |
810 | DEFINE_SINGLE_BUF_MAP(map, XFS_BUF_DADDR_NULL, numblks); | |
1da177e4 | 811 | |
3e85c868 | 812 | bp = _xfs_buf_alloc(target, &map, 1, 0); |
1da177e4 LT |
813 | if (unlikely(bp == NULL)) |
814 | goto fail; | |
1da177e4 | 815 | |
e70b73f8 | 816 | page_count = PAGE_ALIGN(numblks << BBSHIFT) >> PAGE_SHIFT; |
87937bf8 | 817 | error = _xfs_buf_get_pages(bp, page_count); |
1fa40b01 | 818 | if (error) |
1da177e4 LT |
819 | goto fail_free_buf; |
820 | ||
1fa40b01 | 821 | for (i = 0; i < page_count; i++) { |
686865f7 | 822 | bp->b_pages[i] = alloc_page(xb_to_gfp(flags)); |
1fa40b01 CH |
823 | if (!bp->b_pages[i]) |
824 | goto fail_free_mem; | |
1da177e4 | 825 | } |
1fa40b01 | 826 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 827 | |
611c9946 | 828 | error = _xfs_buf_map_pages(bp, 0); |
1fa40b01 | 829 | if (unlikely(error)) { |
4f10700a | 830 | xfs_warn(target->bt_mount, |
08e96e1a | 831 | "%s: failed to map pages", __func__); |
1da177e4 | 832 | goto fail_free_mem; |
1fa40b01 | 833 | } |
1da177e4 | 834 | |
686865f7 | 835 | trace_xfs_buf_get_uncached(bp, _RET_IP_); |
1da177e4 | 836 | return bp; |
1fa40b01 | 837 | |
1da177e4 | 838 | fail_free_mem: |
1fa40b01 CH |
839 | while (--i >= 0) |
840 | __free_page(bp->b_pages[i]); | |
ca165b88 | 841 | _xfs_buf_free_pages(bp); |
1da177e4 | 842 | fail_free_buf: |
3e85c868 | 843 | xfs_buf_free_maps(bp); |
4347b9d7 | 844 | kmem_zone_free(xfs_buf_zone, bp); |
1da177e4 LT |
845 | fail: |
846 | return NULL; | |
847 | } | |
848 | ||
849 | /* | |
1da177e4 LT |
850 | * Increment reference count on buffer, to hold the buffer concurrently |
851 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
852 | * Must hold the buffer already to call this function. |
853 | */ | |
854 | void | |
ce8e922c NS |
855 | xfs_buf_hold( |
856 | xfs_buf_t *bp) | |
1da177e4 | 857 | { |
0b1b213f | 858 | trace_xfs_buf_hold(bp, _RET_IP_); |
ce8e922c | 859 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
860 | } |
861 | ||
862 | /* | |
ce8e922c NS |
863 | * Releases a hold on the specified buffer. If the |
864 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
865 | */ |
866 | void | |
ce8e922c NS |
867 | xfs_buf_rele( |
868 | xfs_buf_t *bp) | |
1da177e4 | 869 | { |
74f75a0c | 870 | struct xfs_perag *pag = bp->b_pag; |
1da177e4 | 871 | |
0b1b213f | 872 | trace_xfs_buf_rele(bp, _RET_IP_); |
1da177e4 | 873 | |
74f75a0c | 874 | if (!pag) { |
430cbeb8 | 875 | ASSERT(list_empty(&bp->b_lru)); |
74f75a0c | 876 | ASSERT(RB_EMPTY_NODE(&bp->b_rbnode)); |
fad3aa1e NS |
877 | if (atomic_dec_and_test(&bp->b_hold)) |
878 | xfs_buf_free(bp); | |
879 | return; | |
880 | } | |
881 | ||
74f75a0c | 882 | ASSERT(!RB_EMPTY_NODE(&bp->b_rbnode)); |
430cbeb8 | 883 | |
3790689f | 884 | ASSERT(atomic_read(&bp->b_hold) > 0); |
74f75a0c | 885 | if (atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock)) { |
a4082357 DC |
886 | spin_lock(&bp->b_lock); |
887 | if (!(bp->b_flags & XBF_STALE) && atomic_read(&bp->b_lru_ref)) { | |
888 | /* | |
889 | * If the buffer is added to the LRU take a new | |
890 | * reference to the buffer for the LRU and clear the | |
891 | * (now stale) dispose list state flag | |
892 | */ | |
893 | if (list_lru_add(&bp->b_target->bt_lru, &bp->b_lru)) { | |
894 | bp->b_state &= ~XFS_BSTATE_DISPOSE; | |
895 | atomic_inc(&bp->b_hold); | |
896 | } | |
897 | spin_unlock(&bp->b_lock); | |
430cbeb8 | 898 | spin_unlock(&pag->pag_buf_lock); |
1da177e4 | 899 | } else { |
a4082357 DC |
900 | /* |
901 | * most of the time buffers will already be removed from | |
902 | * the LRU, so optimise that case by checking for the | |
903 | * XFS_BSTATE_DISPOSE flag indicating the last list the | |
904 | * buffer was on was the disposal list | |
905 | */ | |
906 | if (!(bp->b_state & XFS_BSTATE_DISPOSE)) { | |
907 | list_lru_del(&bp->b_target->bt_lru, &bp->b_lru); | |
908 | } else { | |
909 | ASSERT(list_empty(&bp->b_lru)); | |
910 | } | |
911 | spin_unlock(&bp->b_lock); | |
912 | ||
43ff2122 | 913 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); |
74f75a0c DC |
914 | rb_erase(&bp->b_rbnode, &pag->pag_buf_tree); |
915 | spin_unlock(&pag->pag_buf_lock); | |
916 | xfs_perag_put(pag); | |
ce8e922c | 917 | xfs_buf_free(bp); |
1da177e4 LT |
918 | } |
919 | } | |
920 | } | |
921 | ||
922 | ||
923 | /* | |
0e6e847f | 924 | * Lock a buffer object, if it is not already locked. |
90810b9e DC |
925 | * |
926 | * If we come across a stale, pinned, locked buffer, we know that we are | |
927 | * being asked to lock a buffer that has been reallocated. Because it is | |
928 | * pinned, we know that the log has not been pushed to disk and hence it | |
929 | * will still be locked. Rather than continuing to have trylock attempts | |
930 | * fail until someone else pushes the log, push it ourselves before | |
931 | * returning. This means that the xfsaild will not get stuck trying | |
932 | * to push on stale inode buffers. | |
1da177e4 LT |
933 | */ |
934 | int | |
0c842ad4 CH |
935 | xfs_buf_trylock( |
936 | struct xfs_buf *bp) | |
1da177e4 LT |
937 | { |
938 | int locked; | |
939 | ||
ce8e922c | 940 | locked = down_trylock(&bp->b_sema) == 0; |
0b1b213f | 941 | if (locked) |
ce8e922c | 942 | XB_SET_OWNER(bp); |
0b1b213f | 943 | |
0c842ad4 CH |
944 | trace_xfs_buf_trylock(bp, _RET_IP_); |
945 | return locked; | |
1da177e4 | 946 | } |
1da177e4 LT |
947 | |
948 | /* | |
0e6e847f | 949 | * Lock a buffer object. |
ed3b4d6c DC |
950 | * |
951 | * If we come across a stale, pinned, locked buffer, we know that we | |
952 | * are being asked to lock a buffer that has been reallocated. Because | |
953 | * it is pinned, we know that the log has not been pushed to disk and | |
954 | * hence it will still be locked. Rather than sleeping until someone | |
955 | * else pushes the log, push it ourselves before trying to get the lock. | |
1da177e4 | 956 | */ |
ce8e922c NS |
957 | void |
958 | xfs_buf_lock( | |
0c842ad4 | 959 | struct xfs_buf *bp) |
1da177e4 | 960 | { |
0b1b213f CH |
961 | trace_xfs_buf_lock(bp, _RET_IP_); |
962 | ||
ed3b4d6c | 963 | if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
ebad861b | 964 | xfs_log_force(bp->b_target->bt_mount, 0); |
ce8e922c NS |
965 | down(&bp->b_sema); |
966 | XB_SET_OWNER(bp); | |
0b1b213f CH |
967 | |
968 | trace_xfs_buf_lock_done(bp, _RET_IP_); | |
1da177e4 LT |
969 | } |
970 | ||
1da177e4 | 971 | void |
ce8e922c | 972 | xfs_buf_unlock( |
0c842ad4 | 973 | struct xfs_buf *bp) |
1da177e4 | 974 | { |
ce8e922c NS |
975 | XB_CLEAR_OWNER(bp); |
976 | up(&bp->b_sema); | |
0b1b213f CH |
977 | |
978 | trace_xfs_buf_unlock(bp, _RET_IP_); | |
1da177e4 LT |
979 | } |
980 | ||
ce8e922c NS |
981 | STATIC void |
982 | xfs_buf_wait_unpin( | |
983 | xfs_buf_t *bp) | |
1da177e4 LT |
984 | { |
985 | DECLARE_WAITQUEUE (wait, current); | |
986 | ||
ce8e922c | 987 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
988 | return; |
989 | ||
ce8e922c | 990 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
991 | for (;;) { |
992 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 993 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 994 | break; |
7eaceacc | 995 | io_schedule(); |
1da177e4 | 996 | } |
ce8e922c | 997 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
998 | set_current_state(TASK_RUNNING); |
999 | } | |
1000 | ||
1001 | /* | |
1002 | * Buffer Utility Routines | |
1003 | */ | |
1004 | ||
e8aaba9a DC |
1005 | void |
1006 | xfs_buf_ioend( | |
1007 | struct xfs_buf *bp) | |
1da177e4 | 1008 | { |
e8aaba9a DC |
1009 | bool read = bp->b_flags & XBF_READ; |
1010 | ||
1011 | trace_xfs_buf_iodone(bp, _RET_IP_); | |
1813dd64 DC |
1012 | |
1013 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); | |
d5929de8 | 1014 | |
61be9c52 DC |
1015 | /* |
1016 | * Pull in IO completion errors now. We are guaranteed to be running | |
1017 | * single threaded, so we don't need the lock to read b_io_error. | |
1018 | */ | |
1019 | if (!bp->b_error && bp->b_io_error) | |
1020 | xfs_buf_ioerror(bp, bp->b_io_error); | |
1021 | ||
e8aaba9a DC |
1022 | /* Only validate buffers that were read without errors */ |
1023 | if (read && !bp->b_error && bp->b_ops) { | |
1024 | ASSERT(!bp->b_iodone); | |
1813dd64 | 1025 | bp->b_ops->verify_read(bp); |
e8aaba9a DC |
1026 | } |
1027 | ||
1028 | if (!bp->b_error) | |
1029 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1030 | |
80f6c29d | 1031 | if (bp->b_iodone) |
ce8e922c NS |
1032 | (*(bp->b_iodone))(bp); |
1033 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 | 1034 | xfs_buf_relse(bp); |
595bff75 | 1035 | else |
1813dd64 | 1036 | complete(&bp->b_iowait); |
1da177e4 LT |
1037 | } |
1038 | ||
e8aaba9a DC |
1039 | static void |
1040 | xfs_buf_ioend_work( | |
1041 | struct work_struct *work) | |
1da177e4 | 1042 | { |
e8aaba9a | 1043 | struct xfs_buf *bp = |
b29c70f5 | 1044 | container_of(work, xfs_buf_t, b_ioend_work); |
0b1b213f | 1045 | |
e8aaba9a DC |
1046 | xfs_buf_ioend(bp); |
1047 | } | |
1da177e4 | 1048 | |
e8aaba9a DC |
1049 | void |
1050 | xfs_buf_ioend_async( | |
1051 | struct xfs_buf *bp) | |
1052 | { | |
b29c70f5 BF |
1053 | INIT_WORK(&bp->b_ioend_work, xfs_buf_ioend_work); |
1054 | queue_work(bp->b_ioend_wq, &bp->b_ioend_work); | |
1da177e4 LT |
1055 | } |
1056 | ||
1da177e4 | 1057 | void |
ce8e922c NS |
1058 | xfs_buf_ioerror( |
1059 | xfs_buf_t *bp, | |
1060 | int error) | |
1da177e4 | 1061 | { |
2451337d DC |
1062 | ASSERT(error <= 0 && error >= -1000); |
1063 | bp->b_error = error; | |
0b1b213f | 1064 | trace_xfs_buf_ioerror(bp, error, _RET_IP_); |
1da177e4 LT |
1065 | } |
1066 | ||
901796af CH |
1067 | void |
1068 | xfs_buf_ioerror_alert( | |
1069 | struct xfs_buf *bp, | |
1070 | const char *func) | |
1071 | { | |
1072 | xfs_alert(bp->b_target->bt_mount, | |
aa0e8833 | 1073 | "metadata I/O error: block 0x%llx (\"%s\") error %d numblks %d", |
2451337d | 1074 | (__uint64_t)XFS_BUF_ADDR(bp), func, -bp->b_error, bp->b_length); |
901796af CH |
1075 | } |
1076 | ||
a2dcf5df CH |
1077 | int |
1078 | xfs_bwrite( | |
1079 | struct xfs_buf *bp) | |
1080 | { | |
1081 | int error; | |
1082 | ||
1083 | ASSERT(xfs_buf_islocked(bp)); | |
1084 | ||
1085 | bp->b_flags |= XBF_WRITE; | |
27187754 DC |
1086 | bp->b_flags &= ~(XBF_ASYNC | XBF_READ | _XBF_DELWRI_Q | |
1087 | XBF_WRITE_FAIL | XBF_DONE); | |
a2dcf5df | 1088 | |
595bff75 | 1089 | error = xfs_buf_submit_wait(bp); |
a2dcf5df CH |
1090 | if (error) { |
1091 | xfs_force_shutdown(bp->b_target->bt_mount, | |
1092 | SHUTDOWN_META_IO_ERROR); | |
1093 | } | |
1094 | return error; | |
1095 | } | |
1096 | ||
782e3b3b | 1097 | STATIC void |
ce8e922c | 1098 | xfs_buf_bio_end_io( |
1da177e4 | 1099 | struct bio *bio, |
1da177e4 LT |
1100 | int error) |
1101 | { | |
ce8e922c | 1102 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1da177e4 | 1103 | |
37eb17e6 DC |
1104 | /* |
1105 | * don't overwrite existing errors - otherwise we can lose errors on | |
1106 | * buffers that require multiple bios to complete. | |
1107 | */ | |
61be9c52 DC |
1108 | if (error) { |
1109 | spin_lock(&bp->b_lock); | |
1110 | if (!bp->b_io_error) | |
1111 | bp->b_io_error = error; | |
1112 | spin_unlock(&bp->b_lock); | |
1113 | } | |
1da177e4 | 1114 | |
37eb17e6 | 1115 | if (!bp->b_error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ)) |
73c77e2c JB |
1116 | invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp)); |
1117 | ||
e8aaba9a DC |
1118 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) |
1119 | xfs_buf_ioend_async(bp); | |
1da177e4 | 1120 | bio_put(bio); |
1da177e4 LT |
1121 | } |
1122 | ||
3e85c868 DC |
1123 | static void |
1124 | xfs_buf_ioapply_map( | |
1125 | struct xfs_buf *bp, | |
1126 | int map, | |
1127 | int *buf_offset, | |
1128 | int *count, | |
1129 | int rw) | |
1da177e4 | 1130 | { |
3e85c868 DC |
1131 | int page_index; |
1132 | int total_nr_pages = bp->b_page_count; | |
1133 | int nr_pages; | |
1134 | struct bio *bio; | |
1135 | sector_t sector = bp->b_maps[map].bm_bn; | |
1136 | int size; | |
1137 | int offset; | |
1da177e4 | 1138 | |
ce8e922c | 1139 | total_nr_pages = bp->b_page_count; |
1da177e4 | 1140 | |
3e85c868 DC |
1141 | /* skip the pages in the buffer before the start offset */ |
1142 | page_index = 0; | |
1143 | offset = *buf_offset; | |
1144 | while (offset >= PAGE_SIZE) { | |
1145 | page_index++; | |
1146 | offset -= PAGE_SIZE; | |
f538d4da CH |
1147 | } |
1148 | ||
3e85c868 DC |
1149 | /* |
1150 | * Limit the IO size to the length of the current vector, and update the | |
1151 | * remaining IO count for the next time around. | |
1152 | */ | |
1153 | size = min_t(int, BBTOB(bp->b_maps[map].bm_len), *count); | |
1154 | *count -= size; | |
1155 | *buf_offset += size; | |
34951f5c | 1156 | |
1da177e4 | 1157 | next_chunk: |
ce8e922c | 1158 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1159 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1160 | if (nr_pages > total_nr_pages) | |
1161 | nr_pages = total_nr_pages; | |
1162 | ||
1163 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1164 | bio->bi_bdev = bp->b_target->bt_bdev; |
4f024f37 | 1165 | bio->bi_iter.bi_sector = sector; |
ce8e922c NS |
1166 | bio->bi_end_io = xfs_buf_bio_end_io; |
1167 | bio->bi_private = bp; | |
1da177e4 | 1168 | |
0e6e847f | 1169 | |
3e85c868 | 1170 | for (; size && nr_pages; nr_pages--, page_index++) { |
0e6e847f | 1171 | int rbytes, nbytes = PAGE_SIZE - offset; |
1da177e4 LT |
1172 | |
1173 | if (nbytes > size) | |
1174 | nbytes = size; | |
1175 | ||
3e85c868 DC |
1176 | rbytes = bio_add_page(bio, bp->b_pages[page_index], nbytes, |
1177 | offset); | |
ce8e922c | 1178 | if (rbytes < nbytes) |
1da177e4 LT |
1179 | break; |
1180 | ||
1181 | offset = 0; | |
aa0e8833 | 1182 | sector += BTOBB(nbytes); |
1da177e4 LT |
1183 | size -= nbytes; |
1184 | total_nr_pages--; | |
1185 | } | |
1186 | ||
4f024f37 | 1187 | if (likely(bio->bi_iter.bi_size)) { |
73c77e2c JB |
1188 | if (xfs_buf_is_vmapped(bp)) { |
1189 | flush_kernel_vmap_range(bp->b_addr, | |
1190 | xfs_buf_vmap_len(bp)); | |
1191 | } | |
1da177e4 LT |
1192 | submit_bio(rw, bio); |
1193 | if (size) | |
1194 | goto next_chunk; | |
1195 | } else { | |
37eb17e6 DC |
1196 | /* |
1197 | * This is guaranteed not to be the last io reference count | |
595bff75 | 1198 | * because the caller (xfs_buf_submit) holds a count itself. |
37eb17e6 DC |
1199 | */ |
1200 | atomic_dec(&bp->b_io_remaining); | |
2451337d | 1201 | xfs_buf_ioerror(bp, -EIO); |
ec53d1db | 1202 | bio_put(bio); |
1da177e4 | 1203 | } |
3e85c868 DC |
1204 | |
1205 | } | |
1206 | ||
1207 | STATIC void | |
1208 | _xfs_buf_ioapply( | |
1209 | struct xfs_buf *bp) | |
1210 | { | |
1211 | struct blk_plug plug; | |
1212 | int rw; | |
1213 | int offset; | |
1214 | int size; | |
1215 | int i; | |
1216 | ||
c163f9a1 DC |
1217 | /* |
1218 | * Make sure we capture only current IO errors rather than stale errors | |
1219 | * left over from previous use of the buffer (e.g. failed readahead). | |
1220 | */ | |
1221 | bp->b_error = 0; | |
1222 | ||
b29c70f5 BF |
1223 | /* |
1224 | * Initialize the I/O completion workqueue if we haven't yet or the | |
1225 | * submitter has not opted to specify a custom one. | |
1226 | */ | |
1227 | if (!bp->b_ioend_wq) | |
1228 | bp->b_ioend_wq = bp->b_target->bt_mount->m_buf_workqueue; | |
1229 | ||
3e85c868 DC |
1230 | if (bp->b_flags & XBF_WRITE) { |
1231 | if (bp->b_flags & XBF_SYNCIO) | |
1232 | rw = WRITE_SYNC; | |
1233 | else | |
1234 | rw = WRITE; | |
1235 | if (bp->b_flags & XBF_FUA) | |
1236 | rw |= REQ_FUA; | |
1237 | if (bp->b_flags & XBF_FLUSH) | |
1238 | rw |= REQ_FLUSH; | |
1813dd64 DC |
1239 | |
1240 | /* | |
1241 | * Run the write verifier callback function if it exists. If | |
1242 | * this function fails it will mark the buffer with an error and | |
1243 | * the IO should not be dispatched. | |
1244 | */ | |
1245 | if (bp->b_ops) { | |
1246 | bp->b_ops->verify_write(bp); | |
1247 | if (bp->b_error) { | |
1248 | xfs_force_shutdown(bp->b_target->bt_mount, | |
1249 | SHUTDOWN_CORRUPT_INCORE); | |
1250 | return; | |
1251 | } | |
400b9d88 DC |
1252 | } else if (bp->b_bn != XFS_BUF_DADDR_NULL) { |
1253 | struct xfs_mount *mp = bp->b_target->bt_mount; | |
1254 | ||
1255 | /* | |
1256 | * non-crc filesystems don't attach verifiers during | |
1257 | * log recovery, so don't warn for such filesystems. | |
1258 | */ | |
1259 | if (xfs_sb_version_hascrc(&mp->m_sb)) { | |
1260 | xfs_warn(mp, | |
1261 | "%s: no ops on block 0x%llx/0x%x", | |
1262 | __func__, bp->b_bn, bp->b_length); | |
1263 | xfs_hex_dump(bp->b_addr, 64); | |
1264 | dump_stack(); | |
1265 | } | |
1813dd64 | 1266 | } |
3e85c868 DC |
1267 | } else if (bp->b_flags & XBF_READ_AHEAD) { |
1268 | rw = READA; | |
1269 | } else { | |
1270 | rw = READ; | |
1271 | } | |
1272 | ||
1273 | /* we only use the buffer cache for meta-data */ | |
1274 | rw |= REQ_META; | |
1275 | ||
1276 | /* | |
1277 | * Walk all the vectors issuing IO on them. Set up the initial offset | |
1278 | * into the buffer and the desired IO size before we start - | |
1279 | * _xfs_buf_ioapply_vec() will modify them appropriately for each | |
1280 | * subsequent call. | |
1281 | */ | |
1282 | offset = bp->b_offset; | |
1283 | size = BBTOB(bp->b_io_length); | |
1284 | blk_start_plug(&plug); | |
1285 | for (i = 0; i < bp->b_map_count; i++) { | |
1286 | xfs_buf_ioapply_map(bp, i, &offset, &size, rw); | |
1287 | if (bp->b_error) | |
1288 | break; | |
1289 | if (size <= 0) | |
1290 | break; /* all done */ | |
1291 | } | |
1292 | blk_finish_plug(&plug); | |
1da177e4 LT |
1293 | } |
1294 | ||
595bff75 DC |
1295 | /* |
1296 | * Asynchronous IO submission path. This transfers the buffer lock ownership and | |
1297 | * the current reference to the IO. It is not safe to reference the buffer after | |
1298 | * a call to this function unless the caller holds an additional reference | |
1299 | * itself. | |
1300 | */ | |
0e95f19a | 1301 | void |
595bff75 DC |
1302 | xfs_buf_submit( |
1303 | struct xfs_buf *bp) | |
1da177e4 | 1304 | { |
595bff75 | 1305 | trace_xfs_buf_submit(bp, _RET_IP_); |
1da177e4 | 1306 | |
43ff2122 | 1307 | ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); |
595bff75 DC |
1308 | ASSERT(bp->b_flags & XBF_ASYNC); |
1309 | ||
1310 | /* on shutdown we stale and complete the buffer immediately */ | |
1311 | if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) { | |
1312 | xfs_buf_ioerror(bp, -EIO); | |
1313 | bp->b_flags &= ~XBF_DONE; | |
1314 | xfs_buf_stale(bp); | |
1315 | xfs_buf_ioend(bp); | |
1316 | return; | |
1317 | } | |
1da177e4 | 1318 | |
375ec69d | 1319 | if (bp->b_flags & XBF_WRITE) |
ce8e922c | 1320 | xfs_buf_wait_unpin(bp); |
e11bb805 | 1321 | |
61be9c52 DC |
1322 | /* clear the internal error state to avoid spurious errors */ |
1323 | bp->b_io_error = 0; | |
1324 | ||
e11bb805 | 1325 | /* |
595bff75 DC |
1326 | * The caller's reference is released during I/O completion. |
1327 | * This occurs some time after the last b_io_remaining reference is | |
1328 | * released, so after we drop our Io reference we have to have some | |
1329 | * other reference to ensure the buffer doesn't go away from underneath | |
1330 | * us. Take a direct reference to ensure we have safe access to the | |
1331 | * buffer until we are finished with it. | |
e11bb805 | 1332 | */ |
ce8e922c | 1333 | xfs_buf_hold(bp); |
1da177e4 | 1334 | |
8d6c1210 | 1335 | /* |
e11bb805 DC |
1336 | * Set the count to 1 initially, this will stop an I/O completion |
1337 | * callout which happens before we have started all the I/O from calling | |
1338 | * xfs_buf_ioend too early. | |
1da177e4 | 1339 | */ |
ce8e922c NS |
1340 | atomic_set(&bp->b_io_remaining, 1); |
1341 | _xfs_buf_ioapply(bp); | |
e11bb805 | 1342 | |
8d6c1210 | 1343 | /* |
595bff75 DC |
1344 | * If _xfs_buf_ioapply failed, we can get back here with only the IO |
1345 | * reference we took above. If we drop it to zero, run completion so | |
1346 | * that we don't return to the caller with completion still pending. | |
8d6c1210 | 1347 | */ |
e8aaba9a | 1348 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) { |
595bff75 | 1349 | if (bp->b_error) |
e8aaba9a DC |
1350 | xfs_buf_ioend(bp); |
1351 | else | |
1352 | xfs_buf_ioend_async(bp); | |
1353 | } | |
1da177e4 | 1354 | |
ce8e922c | 1355 | xfs_buf_rele(bp); |
595bff75 | 1356 | /* Note: it is not safe to reference bp now we've dropped our ref */ |
1da177e4 LT |
1357 | } |
1358 | ||
1359 | /* | |
595bff75 | 1360 | * Synchronous buffer IO submission path, read or write. |
1da177e4 LT |
1361 | */ |
1362 | int | |
595bff75 DC |
1363 | xfs_buf_submit_wait( |
1364 | struct xfs_buf *bp) | |
1da177e4 | 1365 | { |
595bff75 | 1366 | int error; |
0b1b213f | 1367 | |
595bff75 DC |
1368 | trace_xfs_buf_submit_wait(bp, _RET_IP_); |
1369 | ||
1370 | ASSERT(!(bp->b_flags & (_XBF_DELWRI_Q | XBF_ASYNC))); | |
0b1b213f | 1371 | |
595bff75 DC |
1372 | if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) { |
1373 | xfs_buf_ioerror(bp, -EIO); | |
1374 | xfs_buf_stale(bp); | |
1375 | bp->b_flags &= ~XBF_DONE; | |
1376 | return -EIO; | |
1377 | } | |
1378 | ||
1379 | if (bp->b_flags & XBF_WRITE) | |
1380 | xfs_buf_wait_unpin(bp); | |
1381 | ||
1382 | /* clear the internal error state to avoid spurious errors */ | |
1383 | bp->b_io_error = 0; | |
1384 | ||
1385 | /* | |
1386 | * For synchronous IO, the IO does not inherit the submitters reference | |
1387 | * count, nor the buffer lock. Hence we cannot release the reference we | |
1388 | * are about to take until we've waited for all IO completion to occur, | |
1389 | * including any xfs_buf_ioend_async() work that may be pending. | |
1390 | */ | |
1391 | xfs_buf_hold(bp); | |
1392 | ||
1393 | /* | |
1394 | * Set the count to 1 initially, this will stop an I/O completion | |
1395 | * callout which happens before we have started all the I/O from calling | |
1396 | * xfs_buf_ioend too early. | |
1397 | */ | |
1398 | atomic_set(&bp->b_io_remaining, 1); | |
1399 | _xfs_buf_ioapply(bp); | |
1400 | ||
1401 | /* | |
1402 | * make sure we run completion synchronously if it raced with us and is | |
1403 | * already complete. | |
1404 | */ | |
1405 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) | |
1406 | xfs_buf_ioend(bp); | |
0b1b213f | 1407 | |
595bff75 DC |
1408 | /* wait for completion before gathering the error from the buffer */ |
1409 | trace_xfs_buf_iowait(bp, _RET_IP_); | |
1410 | wait_for_completion(&bp->b_iowait); | |
0b1b213f | 1411 | trace_xfs_buf_iowait_done(bp, _RET_IP_); |
595bff75 DC |
1412 | error = bp->b_error; |
1413 | ||
1414 | /* | |
1415 | * all done now, we can release the hold that keeps the buffer | |
1416 | * referenced for the entire IO. | |
1417 | */ | |
1418 | xfs_buf_rele(bp); | |
1419 | return error; | |
1da177e4 LT |
1420 | } |
1421 | ||
88ee2df7 | 1422 | void * |
ce8e922c | 1423 | xfs_buf_offset( |
88ee2df7 | 1424 | struct xfs_buf *bp, |
1da177e4 LT |
1425 | size_t offset) |
1426 | { | |
1427 | struct page *page; | |
1428 | ||
611c9946 | 1429 | if (bp->b_addr) |
62926044 | 1430 | return bp->b_addr + offset; |
1da177e4 | 1431 | |
ce8e922c | 1432 | offset += bp->b_offset; |
0e6e847f | 1433 | page = bp->b_pages[offset >> PAGE_SHIFT]; |
88ee2df7 | 1434 | return page_address(page) + (offset & (PAGE_SIZE-1)); |
1da177e4 LT |
1435 | } |
1436 | ||
1437 | /* | |
1da177e4 LT |
1438 | * Move data into or out of a buffer. |
1439 | */ | |
1440 | void | |
ce8e922c NS |
1441 | xfs_buf_iomove( |
1442 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1443 | size_t boff, /* starting buffer offset */ |
1444 | size_t bsize, /* length to copy */ | |
b9c48649 | 1445 | void *data, /* data address */ |
ce8e922c | 1446 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 | 1447 | { |
795cac72 | 1448 | size_t bend; |
1da177e4 LT |
1449 | |
1450 | bend = boff + bsize; | |
1451 | while (boff < bend) { | |
795cac72 DC |
1452 | struct page *page; |
1453 | int page_index, page_offset, csize; | |
1454 | ||
1455 | page_index = (boff + bp->b_offset) >> PAGE_SHIFT; | |
1456 | page_offset = (boff + bp->b_offset) & ~PAGE_MASK; | |
1457 | page = bp->b_pages[page_index]; | |
1458 | csize = min_t(size_t, PAGE_SIZE - page_offset, | |
1459 | BBTOB(bp->b_io_length) - boff); | |
1da177e4 | 1460 | |
795cac72 | 1461 | ASSERT((csize + page_offset) <= PAGE_SIZE); |
1da177e4 LT |
1462 | |
1463 | switch (mode) { | |
ce8e922c | 1464 | case XBRW_ZERO: |
795cac72 | 1465 | memset(page_address(page) + page_offset, 0, csize); |
1da177e4 | 1466 | break; |
ce8e922c | 1467 | case XBRW_READ: |
795cac72 | 1468 | memcpy(data, page_address(page) + page_offset, csize); |
1da177e4 | 1469 | break; |
ce8e922c | 1470 | case XBRW_WRITE: |
795cac72 | 1471 | memcpy(page_address(page) + page_offset, data, csize); |
1da177e4 LT |
1472 | } |
1473 | ||
1474 | boff += csize; | |
1475 | data += csize; | |
1476 | } | |
1477 | } | |
1478 | ||
1479 | /* | |
ce8e922c | 1480 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1481 | */ |
1482 | ||
1483 | /* | |
430cbeb8 DC |
1484 | * Wait for any bufs with callbacks that have been submitted but have not yet |
1485 | * returned. These buffers will have an elevated hold count, so wait on those | |
1486 | * while freeing all the buffers only held by the LRU. | |
1da177e4 | 1487 | */ |
e80dfa19 DC |
1488 | static enum lru_status |
1489 | xfs_buftarg_wait_rele( | |
1490 | struct list_head *item, | |
3f97b163 | 1491 | struct list_lru_one *lru, |
e80dfa19 DC |
1492 | spinlock_t *lru_lock, |
1493 | void *arg) | |
1494 | ||
1da177e4 | 1495 | { |
e80dfa19 | 1496 | struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru); |
a4082357 | 1497 | struct list_head *dispose = arg; |
430cbeb8 | 1498 | |
e80dfa19 | 1499 | if (atomic_read(&bp->b_hold) > 1) { |
a4082357 | 1500 | /* need to wait, so skip it this pass */ |
e80dfa19 | 1501 | trace_xfs_buf_wait_buftarg(bp, _RET_IP_); |
a4082357 | 1502 | return LRU_SKIP; |
1da177e4 | 1503 | } |
a4082357 DC |
1504 | if (!spin_trylock(&bp->b_lock)) |
1505 | return LRU_SKIP; | |
e80dfa19 | 1506 | |
a4082357 DC |
1507 | /* |
1508 | * clear the LRU reference count so the buffer doesn't get | |
1509 | * ignored in xfs_buf_rele(). | |
1510 | */ | |
1511 | atomic_set(&bp->b_lru_ref, 0); | |
1512 | bp->b_state |= XFS_BSTATE_DISPOSE; | |
3f97b163 | 1513 | list_lru_isolate_move(lru, item, dispose); |
a4082357 DC |
1514 | spin_unlock(&bp->b_lock); |
1515 | return LRU_REMOVED; | |
1da177e4 LT |
1516 | } |
1517 | ||
e80dfa19 DC |
1518 | void |
1519 | xfs_wait_buftarg( | |
1520 | struct xfs_buftarg *btp) | |
1521 | { | |
a4082357 DC |
1522 | LIST_HEAD(dispose); |
1523 | int loop = 0; | |
1524 | ||
1525 | /* loop until there is nothing left on the lru list. */ | |
1526 | while (list_lru_count(&btp->bt_lru)) { | |
e80dfa19 | 1527 | list_lru_walk(&btp->bt_lru, xfs_buftarg_wait_rele, |
a4082357 DC |
1528 | &dispose, LONG_MAX); |
1529 | ||
1530 | while (!list_empty(&dispose)) { | |
1531 | struct xfs_buf *bp; | |
1532 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); | |
1533 | list_del_init(&bp->b_lru); | |
ac8809f9 DC |
1534 | if (bp->b_flags & XBF_WRITE_FAIL) { |
1535 | xfs_alert(btp->bt_mount, | |
1536 | "Corruption Alert: Buffer at block 0x%llx had permanent write failures!\n" | |
1537 | "Please run xfs_repair to determine the extent of the problem.", | |
1538 | (long long)bp->b_bn); | |
1539 | } | |
a4082357 DC |
1540 | xfs_buf_rele(bp); |
1541 | } | |
1542 | if (loop++ != 0) | |
1543 | delay(100); | |
1544 | } | |
e80dfa19 DC |
1545 | } |
1546 | ||
1547 | static enum lru_status | |
1548 | xfs_buftarg_isolate( | |
1549 | struct list_head *item, | |
3f97b163 | 1550 | struct list_lru_one *lru, |
e80dfa19 DC |
1551 | spinlock_t *lru_lock, |
1552 | void *arg) | |
1553 | { | |
1554 | struct xfs_buf *bp = container_of(item, struct xfs_buf, b_lru); | |
1555 | struct list_head *dispose = arg; | |
1556 | ||
a4082357 DC |
1557 | /* |
1558 | * we are inverting the lru lock/bp->b_lock here, so use a trylock. | |
1559 | * If we fail to get the lock, just skip it. | |
1560 | */ | |
1561 | if (!spin_trylock(&bp->b_lock)) | |
1562 | return LRU_SKIP; | |
e80dfa19 DC |
1563 | /* |
1564 | * Decrement the b_lru_ref count unless the value is already | |
1565 | * zero. If the value is already zero, we need to reclaim the | |
1566 | * buffer, otherwise it gets another trip through the LRU. | |
1567 | */ | |
a4082357 DC |
1568 | if (!atomic_add_unless(&bp->b_lru_ref, -1, 0)) { |
1569 | spin_unlock(&bp->b_lock); | |
e80dfa19 | 1570 | return LRU_ROTATE; |
a4082357 | 1571 | } |
e80dfa19 | 1572 | |
a4082357 | 1573 | bp->b_state |= XFS_BSTATE_DISPOSE; |
3f97b163 | 1574 | list_lru_isolate_move(lru, item, dispose); |
a4082357 | 1575 | spin_unlock(&bp->b_lock); |
e80dfa19 DC |
1576 | return LRU_REMOVED; |
1577 | } | |
1578 | ||
addbda40 | 1579 | static unsigned long |
e80dfa19 | 1580 | xfs_buftarg_shrink_scan( |
ff57ab21 | 1581 | struct shrinker *shrink, |
1495f230 | 1582 | struct shrink_control *sc) |
a6867a68 | 1583 | { |
ff57ab21 DC |
1584 | struct xfs_buftarg *btp = container_of(shrink, |
1585 | struct xfs_buftarg, bt_shrinker); | |
430cbeb8 | 1586 | LIST_HEAD(dispose); |
addbda40 | 1587 | unsigned long freed; |
430cbeb8 | 1588 | |
503c358c VD |
1589 | freed = list_lru_shrink_walk(&btp->bt_lru, sc, |
1590 | xfs_buftarg_isolate, &dispose); | |
430cbeb8 DC |
1591 | |
1592 | while (!list_empty(&dispose)) { | |
e80dfa19 | 1593 | struct xfs_buf *bp; |
430cbeb8 DC |
1594 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); |
1595 | list_del_init(&bp->b_lru); | |
1596 | xfs_buf_rele(bp); | |
1597 | } | |
1598 | ||
e80dfa19 DC |
1599 | return freed; |
1600 | } | |
1601 | ||
addbda40 | 1602 | static unsigned long |
e80dfa19 DC |
1603 | xfs_buftarg_shrink_count( |
1604 | struct shrinker *shrink, | |
1605 | struct shrink_control *sc) | |
1606 | { | |
1607 | struct xfs_buftarg *btp = container_of(shrink, | |
1608 | struct xfs_buftarg, bt_shrinker); | |
503c358c | 1609 | return list_lru_shrink_count(&btp->bt_lru, sc); |
a6867a68 DC |
1610 | } |
1611 | ||
1da177e4 LT |
1612 | void |
1613 | xfs_free_buftarg( | |
b7963133 CH |
1614 | struct xfs_mount *mp, |
1615 | struct xfs_buftarg *btp) | |
1da177e4 | 1616 | { |
ff57ab21 | 1617 | unregister_shrinker(&btp->bt_shrinker); |
f5e1dd34 | 1618 | list_lru_destroy(&btp->bt_lru); |
ff57ab21 | 1619 | |
b7963133 CH |
1620 | if (mp->m_flags & XFS_MOUNT_BARRIER) |
1621 | xfs_blkdev_issue_flush(btp); | |
a6867a68 | 1622 | |
f0e2d93c | 1623 | kmem_free(btp); |
1da177e4 LT |
1624 | } |
1625 | ||
3fefdeee ES |
1626 | int |
1627 | xfs_setsize_buftarg( | |
1da177e4 | 1628 | xfs_buftarg_t *btp, |
3fefdeee | 1629 | unsigned int sectorsize) |
1da177e4 | 1630 | { |
7c71ee78 | 1631 | /* Set up metadata sector size info */ |
6da54179 ES |
1632 | btp->bt_meta_sectorsize = sectorsize; |
1633 | btp->bt_meta_sectormask = sectorsize - 1; | |
1da177e4 | 1634 | |
ce8e922c | 1635 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
02b102df CH |
1636 | char name[BDEVNAME_SIZE]; |
1637 | ||
1638 | bdevname(btp->bt_bdev, name); | |
1639 | ||
4f10700a | 1640 | xfs_warn(btp->bt_mount, |
08e96e1a | 1641 | "Cannot set_blocksize to %u on device %s", |
02b102df | 1642 | sectorsize, name); |
2451337d | 1643 | return -EINVAL; |
1da177e4 LT |
1644 | } |
1645 | ||
7c71ee78 ES |
1646 | /* Set up device logical sector size mask */ |
1647 | btp->bt_logical_sectorsize = bdev_logical_block_size(btp->bt_bdev); | |
1648 | btp->bt_logical_sectormask = bdev_logical_block_size(btp->bt_bdev) - 1; | |
1649 | ||
1da177e4 LT |
1650 | return 0; |
1651 | } | |
1652 | ||
1653 | /* | |
3fefdeee ES |
1654 | * When allocating the initial buffer target we have not yet |
1655 | * read in the superblock, so don't know what sized sectors | |
1656 | * are being used at this early stage. Play safe. | |
ce8e922c | 1657 | */ |
1da177e4 LT |
1658 | STATIC int |
1659 | xfs_setsize_buftarg_early( | |
1660 | xfs_buftarg_t *btp, | |
1661 | struct block_device *bdev) | |
1662 | { | |
a96c4151 | 1663 | return xfs_setsize_buftarg(btp, bdev_logical_block_size(bdev)); |
1da177e4 LT |
1664 | } |
1665 | ||
1da177e4 LT |
1666 | xfs_buftarg_t * |
1667 | xfs_alloc_buftarg( | |
ebad861b | 1668 | struct xfs_mount *mp, |
34dcefd7 | 1669 | struct block_device *bdev) |
1da177e4 LT |
1670 | { |
1671 | xfs_buftarg_t *btp; | |
1672 | ||
b17cb364 | 1673 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP | KM_NOFS); |
1da177e4 | 1674 | |
ebad861b | 1675 | btp->bt_mount = mp; |
ce8e922c NS |
1676 | btp->bt_dev = bdev->bd_dev; |
1677 | btp->bt_bdev = bdev; | |
0e6e847f | 1678 | btp->bt_bdi = blk_get_backing_dev_info(bdev); |
0e6e847f | 1679 | |
1da177e4 LT |
1680 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1681 | goto error; | |
5ca302c8 GC |
1682 | |
1683 | if (list_lru_init(&btp->bt_lru)) | |
1684 | goto error; | |
1685 | ||
e80dfa19 DC |
1686 | btp->bt_shrinker.count_objects = xfs_buftarg_shrink_count; |
1687 | btp->bt_shrinker.scan_objects = xfs_buftarg_shrink_scan; | |
ff57ab21 | 1688 | btp->bt_shrinker.seeks = DEFAULT_SEEKS; |
e80dfa19 | 1689 | btp->bt_shrinker.flags = SHRINKER_NUMA_AWARE; |
ff57ab21 | 1690 | register_shrinker(&btp->bt_shrinker); |
1da177e4 LT |
1691 | return btp; |
1692 | ||
1693 | error: | |
f0e2d93c | 1694 | kmem_free(btp); |
1da177e4 LT |
1695 | return NULL; |
1696 | } | |
1697 | ||
1da177e4 | 1698 | /* |
43ff2122 CH |
1699 | * Add a buffer to the delayed write list. |
1700 | * | |
1701 | * This queues a buffer for writeout if it hasn't already been. Note that | |
1702 | * neither this routine nor the buffer list submission functions perform | |
1703 | * any internal synchronization. It is expected that the lists are thread-local | |
1704 | * to the callers. | |
1705 | * | |
1706 | * Returns true if we queued up the buffer, or false if it already had | |
1707 | * been on the buffer list. | |
1da177e4 | 1708 | */ |
43ff2122 | 1709 | bool |
ce8e922c | 1710 | xfs_buf_delwri_queue( |
43ff2122 CH |
1711 | struct xfs_buf *bp, |
1712 | struct list_head *list) | |
1da177e4 | 1713 | { |
43ff2122 | 1714 | ASSERT(xfs_buf_islocked(bp)); |
5a8ee6ba | 1715 | ASSERT(!(bp->b_flags & XBF_READ)); |
1da177e4 | 1716 | |
43ff2122 CH |
1717 | /* |
1718 | * If the buffer is already marked delwri it already is queued up | |
1719 | * by someone else for imediate writeout. Just ignore it in that | |
1720 | * case. | |
1721 | */ | |
1722 | if (bp->b_flags & _XBF_DELWRI_Q) { | |
1723 | trace_xfs_buf_delwri_queued(bp, _RET_IP_); | |
1724 | return false; | |
1da177e4 | 1725 | } |
1da177e4 | 1726 | |
43ff2122 | 1727 | trace_xfs_buf_delwri_queue(bp, _RET_IP_); |
d808f617 DC |
1728 | |
1729 | /* | |
43ff2122 CH |
1730 | * If a buffer gets written out synchronously or marked stale while it |
1731 | * is on a delwri list we lazily remove it. To do this, the other party | |
1732 | * clears the _XBF_DELWRI_Q flag but otherwise leaves the buffer alone. | |
1733 | * It remains referenced and on the list. In a rare corner case it | |
1734 | * might get readded to a delwri list after the synchronous writeout, in | |
1735 | * which case we need just need to re-add the flag here. | |
d808f617 | 1736 | */ |
43ff2122 CH |
1737 | bp->b_flags |= _XBF_DELWRI_Q; |
1738 | if (list_empty(&bp->b_list)) { | |
1739 | atomic_inc(&bp->b_hold); | |
1740 | list_add_tail(&bp->b_list, list); | |
585e6d88 | 1741 | } |
585e6d88 | 1742 | |
43ff2122 | 1743 | return true; |
585e6d88 DC |
1744 | } |
1745 | ||
089716aa DC |
1746 | /* |
1747 | * Compare function is more complex than it needs to be because | |
1748 | * the return value is only 32 bits and we are doing comparisons | |
1749 | * on 64 bit values | |
1750 | */ | |
1751 | static int | |
1752 | xfs_buf_cmp( | |
1753 | void *priv, | |
1754 | struct list_head *a, | |
1755 | struct list_head *b) | |
1756 | { | |
1757 | struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list); | |
1758 | struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); | |
1759 | xfs_daddr_t diff; | |
1760 | ||
f4b42421 | 1761 | diff = ap->b_maps[0].bm_bn - bp->b_maps[0].bm_bn; |
089716aa DC |
1762 | if (diff < 0) |
1763 | return -1; | |
1764 | if (diff > 0) | |
1765 | return 1; | |
1766 | return 0; | |
1767 | } | |
1768 | ||
43ff2122 CH |
1769 | static int |
1770 | __xfs_buf_delwri_submit( | |
1771 | struct list_head *buffer_list, | |
1772 | struct list_head *io_list, | |
1773 | bool wait) | |
1da177e4 | 1774 | { |
43ff2122 CH |
1775 | struct blk_plug plug; |
1776 | struct xfs_buf *bp, *n; | |
1777 | int pinned = 0; | |
1778 | ||
1779 | list_for_each_entry_safe(bp, n, buffer_list, b_list) { | |
1780 | if (!wait) { | |
1781 | if (xfs_buf_ispinned(bp)) { | |
1782 | pinned++; | |
1783 | continue; | |
1784 | } | |
1785 | if (!xfs_buf_trylock(bp)) | |
1786 | continue; | |
1787 | } else { | |
1788 | xfs_buf_lock(bp); | |
1789 | } | |
978c7b2f | 1790 | |
43ff2122 CH |
1791 | /* |
1792 | * Someone else might have written the buffer synchronously or | |
1793 | * marked it stale in the meantime. In that case only the | |
1794 | * _XBF_DELWRI_Q flag got cleared, and we have to drop the | |
1795 | * reference and remove it from the list here. | |
1796 | */ | |
1797 | if (!(bp->b_flags & _XBF_DELWRI_Q)) { | |
1798 | list_del_init(&bp->b_list); | |
1799 | xfs_buf_relse(bp); | |
1800 | continue; | |
1801 | } | |
c9c12971 | 1802 | |
43ff2122 CH |
1803 | list_move_tail(&bp->b_list, io_list); |
1804 | trace_xfs_buf_delwri_split(bp, _RET_IP_); | |
1805 | } | |
1da177e4 | 1806 | |
43ff2122 | 1807 | list_sort(NULL, io_list, xfs_buf_cmp); |
1da177e4 | 1808 | |
43ff2122 CH |
1809 | blk_start_plug(&plug); |
1810 | list_for_each_entry_safe(bp, n, io_list, b_list) { | |
ac8809f9 | 1811 | bp->b_flags &= ~(_XBF_DELWRI_Q | XBF_ASYNC | XBF_WRITE_FAIL); |
cf53e99d | 1812 | bp->b_flags |= XBF_WRITE | XBF_ASYNC; |
a1b7ea5d | 1813 | |
cf53e99d DC |
1814 | /* |
1815 | * we do all Io submission async. This means if we need to wait | |
1816 | * for IO completion we need to take an extra reference so the | |
1817 | * buffer is still valid on the other side. | |
1818 | */ | |
1819 | if (wait) | |
1820 | xfs_buf_hold(bp); | |
1821 | else | |
ce8e922c | 1822 | list_del_init(&bp->b_list); |
8dac3921 | 1823 | |
595bff75 | 1824 | xfs_buf_submit(bp); |
43ff2122 CH |
1825 | } |
1826 | blk_finish_plug(&plug); | |
1da177e4 | 1827 | |
43ff2122 | 1828 | return pinned; |
1da177e4 LT |
1829 | } |
1830 | ||
1831 | /* | |
43ff2122 CH |
1832 | * Write out a buffer list asynchronously. |
1833 | * | |
1834 | * This will take the @buffer_list, write all non-locked and non-pinned buffers | |
1835 | * out and not wait for I/O completion on any of the buffers. This interface | |
1836 | * is only safely useable for callers that can track I/O completion by higher | |
1837 | * level means, e.g. AIL pushing as the @buffer_list is consumed in this | |
1838 | * function. | |
1da177e4 LT |
1839 | */ |
1840 | int | |
43ff2122 CH |
1841 | xfs_buf_delwri_submit_nowait( |
1842 | struct list_head *buffer_list) | |
1da177e4 | 1843 | { |
43ff2122 CH |
1844 | LIST_HEAD (io_list); |
1845 | return __xfs_buf_delwri_submit(buffer_list, &io_list, false); | |
1846 | } | |
1da177e4 | 1847 | |
43ff2122 CH |
1848 | /* |
1849 | * Write out a buffer list synchronously. | |
1850 | * | |
1851 | * This will take the @buffer_list, write all buffers out and wait for I/O | |
1852 | * completion on all of the buffers. @buffer_list is consumed by the function, | |
1853 | * so callers must have some other way of tracking buffers if they require such | |
1854 | * functionality. | |
1855 | */ | |
1856 | int | |
1857 | xfs_buf_delwri_submit( | |
1858 | struct list_head *buffer_list) | |
1859 | { | |
1860 | LIST_HEAD (io_list); | |
1861 | int error = 0, error2; | |
1862 | struct xfs_buf *bp; | |
1da177e4 | 1863 | |
43ff2122 | 1864 | __xfs_buf_delwri_submit(buffer_list, &io_list, true); |
1da177e4 | 1865 | |
43ff2122 CH |
1866 | /* Wait for IO to complete. */ |
1867 | while (!list_empty(&io_list)) { | |
1868 | bp = list_first_entry(&io_list, struct xfs_buf, b_list); | |
a1b7ea5d | 1869 | |
089716aa | 1870 | list_del_init(&bp->b_list); |
cf53e99d DC |
1871 | |
1872 | /* locking the buffer will wait for async IO completion. */ | |
1873 | xfs_buf_lock(bp); | |
1874 | error2 = bp->b_error; | |
43ff2122 CH |
1875 | xfs_buf_relse(bp); |
1876 | if (!error) | |
1877 | error = error2; | |
1da177e4 LT |
1878 | } |
1879 | ||
43ff2122 | 1880 | return error; |
1da177e4 LT |
1881 | } |
1882 | ||
04d8b284 | 1883 | int __init |
ce8e922c | 1884 | xfs_buf_init(void) |
1da177e4 | 1885 | { |
8758280f NS |
1886 | xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf", |
1887 | KM_ZONE_HWALIGN, NULL); | |
ce8e922c | 1888 | if (!xfs_buf_zone) |
0b1b213f | 1889 | goto out; |
04d8b284 | 1890 | |
23ea4032 | 1891 | return 0; |
1da177e4 | 1892 | |
0b1b213f | 1893 | out: |
8758280f | 1894 | return -ENOMEM; |
1da177e4 LT |
1895 | } |
1896 | ||
1da177e4 | 1897 | void |
ce8e922c | 1898 | xfs_buf_terminate(void) |
1da177e4 | 1899 | { |
ce8e922c | 1900 | kmem_zone_destroy(xfs_buf_zone); |
1da177e4 | 1901 | } |