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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 | |
b7963133 CH |
37 | #include "xfs_sb.h" |
38 | #include "xfs_inum.h" | |
ed3b4d6c | 39 | #include "xfs_log.h" |
b7963133 | 40 | #include "xfs_ag.h" |
b7963133 | 41 | #include "xfs_mount.h" |
0b1b213f | 42 | #include "xfs_trace.h" |
b7963133 | 43 | |
7989cb8e | 44 | static kmem_zone_t *xfs_buf_zone; |
a6867a68 | 45 | STATIC int xfsbufd(void *); |
23ea4032 | 46 | |
7989cb8e | 47 | static struct workqueue_struct *xfslogd_workqueue; |
0829c360 | 48 | struct workqueue_struct *xfsdatad_workqueue; |
c626d174 | 49 | struct workqueue_struct *xfsconvertd_workqueue; |
1da177e4 | 50 | |
ce8e922c NS |
51 | #ifdef XFS_BUF_LOCK_TRACKING |
52 | # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid) | |
53 | # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1) | |
54 | # define XB_GET_OWNER(bp) ((bp)->b_last_holder) | |
1da177e4 | 55 | #else |
ce8e922c NS |
56 | # define XB_SET_OWNER(bp) do { } while (0) |
57 | # define XB_CLEAR_OWNER(bp) do { } while (0) | |
58 | # define XB_GET_OWNER(bp) do { } while (0) | |
1da177e4 LT |
59 | #endif |
60 | ||
ce8e922c NS |
61 | #define xb_to_gfp(flags) \ |
62 | ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : \ | |
63 | ((flags) & XBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN) | |
1da177e4 | 64 | |
ce8e922c NS |
65 | #define xb_to_km(flags) \ |
66 | (((flags) & XBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP) | |
1da177e4 | 67 | |
ce8e922c NS |
68 | #define xfs_buf_allocate(flags) \ |
69 | kmem_zone_alloc(xfs_buf_zone, xb_to_km(flags)) | |
70 | #define xfs_buf_deallocate(bp) \ | |
71 | kmem_zone_free(xfs_buf_zone, (bp)); | |
1da177e4 | 72 | |
73c77e2c JB |
73 | static inline int |
74 | xfs_buf_is_vmapped( | |
75 | struct xfs_buf *bp) | |
76 | { | |
77 | /* | |
78 | * Return true if the buffer is vmapped. | |
79 | * | |
80 | * The XBF_MAPPED flag is set if the buffer should be mapped, but the | |
81 | * code is clever enough to know it doesn't have to map a single page, | |
82 | * so the check has to be both for XBF_MAPPED and bp->b_page_count > 1. | |
83 | */ | |
84 | return (bp->b_flags & XBF_MAPPED) && bp->b_page_count > 1; | |
85 | } | |
86 | ||
87 | static inline int | |
88 | xfs_buf_vmap_len( | |
89 | struct xfs_buf *bp) | |
90 | { | |
91 | return (bp->b_page_count * PAGE_SIZE) - bp->b_offset; | |
92 | } | |
93 | ||
1da177e4 | 94 | /* |
430cbeb8 DC |
95 | * xfs_buf_lru_add - add a buffer to the LRU. |
96 | * | |
97 | * The LRU takes a new reference to the buffer so that it will only be freed | |
98 | * once the shrinker takes the buffer off the LRU. | |
99 | */ | |
100 | STATIC void | |
101 | xfs_buf_lru_add( | |
102 | struct xfs_buf *bp) | |
103 | { | |
104 | struct xfs_buftarg *btp = bp->b_target; | |
105 | ||
106 | spin_lock(&btp->bt_lru_lock); | |
107 | if (list_empty(&bp->b_lru)) { | |
108 | atomic_inc(&bp->b_hold); | |
109 | list_add_tail(&bp->b_lru, &btp->bt_lru); | |
110 | btp->bt_lru_nr++; | |
111 | } | |
112 | spin_unlock(&btp->bt_lru_lock); | |
113 | } | |
114 | ||
115 | /* | |
116 | * xfs_buf_lru_del - remove a buffer from the LRU | |
117 | * | |
118 | * The unlocked check is safe here because it only occurs when there are not | |
119 | * b_lru_ref counts left on the inode under the pag->pag_buf_lock. it is there | |
120 | * to optimise the shrinker removing the buffer from the LRU and calling | |
25985edc | 121 | * xfs_buf_free(). i.e. it removes an unnecessary round trip on the |
430cbeb8 | 122 | * bt_lru_lock. |
1da177e4 | 123 | */ |
430cbeb8 DC |
124 | STATIC void |
125 | xfs_buf_lru_del( | |
126 | struct xfs_buf *bp) | |
127 | { | |
128 | struct xfs_buftarg *btp = bp->b_target; | |
129 | ||
130 | if (list_empty(&bp->b_lru)) | |
131 | return; | |
132 | ||
133 | spin_lock(&btp->bt_lru_lock); | |
134 | if (!list_empty(&bp->b_lru)) { | |
135 | list_del_init(&bp->b_lru); | |
136 | btp->bt_lru_nr--; | |
137 | } | |
138 | spin_unlock(&btp->bt_lru_lock); | |
139 | } | |
140 | ||
141 | /* | |
142 | * When we mark a buffer stale, we remove the buffer from the LRU and clear the | |
143 | * b_lru_ref count so that the buffer is freed immediately when the buffer | |
144 | * reference count falls to zero. If the buffer is already on the LRU, we need | |
145 | * to remove the reference that LRU holds on the buffer. | |
146 | * | |
147 | * This prevents build-up of stale buffers on the LRU. | |
148 | */ | |
149 | void | |
150 | xfs_buf_stale( | |
151 | struct xfs_buf *bp) | |
152 | { | |
153 | bp->b_flags |= XBF_STALE; | |
154 | atomic_set(&(bp)->b_lru_ref, 0); | |
155 | if (!list_empty(&bp->b_lru)) { | |
156 | struct xfs_buftarg *btp = bp->b_target; | |
157 | ||
158 | spin_lock(&btp->bt_lru_lock); | |
159 | if (!list_empty(&bp->b_lru)) { | |
160 | list_del_init(&bp->b_lru); | |
161 | btp->bt_lru_nr--; | |
162 | atomic_dec(&bp->b_hold); | |
163 | } | |
164 | spin_unlock(&btp->bt_lru_lock); | |
165 | } | |
166 | ASSERT(atomic_read(&bp->b_hold) >= 1); | |
167 | } | |
1da177e4 LT |
168 | |
169 | STATIC void | |
ce8e922c NS |
170 | _xfs_buf_initialize( |
171 | xfs_buf_t *bp, | |
1da177e4 | 172 | xfs_buftarg_t *target, |
204ab25f | 173 | xfs_off_t range_base, |
1da177e4 | 174 | size_t range_length, |
ce8e922c | 175 | xfs_buf_flags_t flags) |
1da177e4 LT |
176 | { |
177 | /* | |
ce8e922c | 178 | * We don't want certain flags to appear in b_flags. |
1da177e4 | 179 | */ |
ce8e922c NS |
180 | flags &= ~(XBF_LOCK|XBF_MAPPED|XBF_DONT_BLOCK|XBF_READ_AHEAD); |
181 | ||
182 | memset(bp, 0, sizeof(xfs_buf_t)); | |
183 | atomic_set(&bp->b_hold, 1); | |
430cbeb8 | 184 | atomic_set(&bp->b_lru_ref, 1); |
b4dd330b | 185 | init_completion(&bp->b_iowait); |
430cbeb8 | 186 | INIT_LIST_HEAD(&bp->b_lru); |
ce8e922c | 187 | INIT_LIST_HEAD(&bp->b_list); |
74f75a0c | 188 | RB_CLEAR_NODE(&bp->b_rbnode); |
a731cd11 | 189 | sema_init(&bp->b_sema, 0); /* held, no waiters */ |
ce8e922c NS |
190 | XB_SET_OWNER(bp); |
191 | bp->b_target = target; | |
192 | bp->b_file_offset = range_base; | |
1da177e4 LT |
193 | /* |
194 | * Set buffer_length and count_desired to the same value initially. | |
195 | * I/O routines should use count_desired, which will be the same in | |
196 | * most cases but may be reset (e.g. XFS recovery). | |
197 | */ | |
ce8e922c NS |
198 | bp->b_buffer_length = bp->b_count_desired = range_length; |
199 | bp->b_flags = flags; | |
200 | bp->b_bn = XFS_BUF_DADDR_NULL; | |
201 | atomic_set(&bp->b_pin_count, 0); | |
202 | init_waitqueue_head(&bp->b_waiters); | |
203 | ||
204 | XFS_STATS_INC(xb_create); | |
0b1b213f CH |
205 | |
206 | trace_xfs_buf_init(bp, _RET_IP_); | |
1da177e4 LT |
207 | } |
208 | ||
209 | /* | |
ce8e922c NS |
210 | * Allocate a page array capable of holding a specified number |
211 | * of pages, and point the page buf at it. | |
1da177e4 LT |
212 | */ |
213 | STATIC int | |
ce8e922c NS |
214 | _xfs_buf_get_pages( |
215 | xfs_buf_t *bp, | |
1da177e4 | 216 | int page_count, |
ce8e922c | 217 | xfs_buf_flags_t flags) |
1da177e4 LT |
218 | { |
219 | /* Make sure that we have a page list */ | |
ce8e922c NS |
220 | if (bp->b_pages == NULL) { |
221 | bp->b_offset = xfs_buf_poff(bp->b_file_offset); | |
222 | bp->b_page_count = page_count; | |
223 | if (page_count <= XB_PAGES) { | |
224 | bp->b_pages = bp->b_page_array; | |
1da177e4 | 225 | } else { |
ce8e922c NS |
226 | bp->b_pages = kmem_alloc(sizeof(struct page *) * |
227 | page_count, xb_to_km(flags)); | |
228 | if (bp->b_pages == NULL) | |
1da177e4 LT |
229 | return -ENOMEM; |
230 | } | |
ce8e922c | 231 | memset(bp->b_pages, 0, sizeof(struct page *) * page_count); |
1da177e4 LT |
232 | } |
233 | return 0; | |
234 | } | |
235 | ||
236 | /* | |
ce8e922c | 237 | * Frees b_pages if it was allocated. |
1da177e4 LT |
238 | */ |
239 | STATIC void | |
ce8e922c | 240 | _xfs_buf_free_pages( |
1da177e4 LT |
241 | xfs_buf_t *bp) |
242 | { | |
ce8e922c | 243 | if (bp->b_pages != bp->b_page_array) { |
f0e2d93c | 244 | kmem_free(bp->b_pages); |
3fc98b1a | 245 | bp->b_pages = NULL; |
1da177e4 LT |
246 | } |
247 | } | |
248 | ||
249 | /* | |
250 | * Releases the specified buffer. | |
251 | * | |
252 | * The modification state of any associated pages is left unchanged. | |
ce8e922c | 253 | * The buffer most not be on any hash - use xfs_buf_rele instead for |
1da177e4 LT |
254 | * hashed and refcounted buffers |
255 | */ | |
256 | void | |
ce8e922c | 257 | xfs_buf_free( |
1da177e4 LT |
258 | xfs_buf_t *bp) |
259 | { | |
0b1b213f | 260 | trace_xfs_buf_free(bp, _RET_IP_); |
1da177e4 | 261 | |
430cbeb8 DC |
262 | ASSERT(list_empty(&bp->b_lru)); |
263 | ||
0e6e847f | 264 | if (bp->b_flags & _XBF_PAGES) { |
1da177e4 LT |
265 | uint i; |
266 | ||
73c77e2c | 267 | if (xfs_buf_is_vmapped(bp)) |
8a262e57 AE |
268 | vm_unmap_ram(bp->b_addr - bp->b_offset, |
269 | bp->b_page_count); | |
1da177e4 | 270 | |
948ecdb4 NS |
271 | for (i = 0; i < bp->b_page_count; i++) { |
272 | struct page *page = bp->b_pages[i]; | |
273 | ||
0e6e847f | 274 | __free_page(page); |
948ecdb4 | 275 | } |
0e6e847f DC |
276 | } else if (bp->b_flags & _XBF_KMEM) |
277 | kmem_free(bp->b_addr); | |
3fc98b1a | 278 | _xfs_buf_free_pages(bp); |
ce8e922c | 279 | xfs_buf_deallocate(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 | { | |
ce8e922c | 290 | size_t size = bp->b_count_desired; |
1da177e4 | 291 | size_t nbytes, offset; |
ce8e922c | 292 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 | 293 | unsigned short page_count, i; |
204ab25f | 294 | xfs_off_t 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 | */ | |
302 | if (bp->b_buffer_length < PAGE_SIZE) { | |
303 | bp->b_addr = kmem_alloc(bp->b_buffer_length, xb_to_km(flags)); | |
304 | if (!bp->b_addr) { | |
305 | /* low memory - use alloc_page loop instead */ | |
306 | goto use_alloc_page; | |
307 | } | |
308 | ||
309 | if (((unsigned long)(bp->b_addr + bp->b_buffer_length - 1) & | |
310 | PAGE_MASK) != | |
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; | |
321 | bp->b_flags |= XBF_MAPPED | _XBF_KMEM; | |
322 | return 0; | |
323 | } | |
324 | ||
325 | use_alloc_page: | |
ce8e922c NS |
326 | end = bp->b_file_offset + bp->b_buffer_length; |
327 | page_count = xfs_buf_btoc(end) - xfs_buf_btoct(bp->b_file_offset); | |
ce8e922c | 328 | error = _xfs_buf_get_pages(bp, page_count, flags); |
1da177e4 LT |
329 | if (unlikely(error)) |
330 | return error; | |
1da177e4 | 331 | |
ce8e922c | 332 | offset = bp->b_offset; |
0e6e847f | 333 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 334 | |
ce8e922c | 335 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
336 | struct page *page; |
337 | uint retries = 0; | |
0e6e847f DC |
338 | retry: |
339 | page = alloc_page(gfp_mask); | |
1da177e4 | 340 | if (unlikely(page == NULL)) { |
ce8e922c NS |
341 | if (flags & XBF_READ_AHEAD) { |
342 | bp->b_page_count = i; | |
0e6e847f DC |
343 | error = ENOMEM; |
344 | goto out_free_pages; | |
1da177e4 LT |
345 | } |
346 | ||
347 | /* | |
348 | * This could deadlock. | |
349 | * | |
350 | * But until all the XFS lowlevel code is revamped to | |
351 | * handle buffer allocation failures we can't do much. | |
352 | */ | |
353 | if (!(++retries % 100)) | |
4f10700a DC |
354 | xfs_err(NULL, |
355 | "possible memory allocation deadlock in %s (mode:0x%x)", | |
34a622b2 | 356 | __func__, gfp_mask); |
1da177e4 | 357 | |
ce8e922c | 358 | XFS_STATS_INC(xb_page_retries); |
8aa7e847 | 359 | congestion_wait(BLK_RW_ASYNC, HZ/50); |
1da177e4 LT |
360 | goto retry; |
361 | } | |
362 | ||
ce8e922c | 363 | XFS_STATS_INC(xb_page_found); |
1da177e4 | 364 | |
0e6e847f | 365 | nbytes = min_t(size_t, size, PAGE_SIZE - offset); |
1da177e4 | 366 | size -= nbytes; |
ce8e922c | 367 | bp->b_pages[i] = page; |
1da177e4 LT |
368 | offset = 0; |
369 | } | |
0e6e847f | 370 | return 0; |
1da177e4 | 371 | |
0e6e847f DC |
372 | out_free_pages: |
373 | for (i = 0; i < bp->b_page_count; i++) | |
374 | __free_page(bp->b_pages[i]); | |
1da177e4 LT |
375 | return error; |
376 | } | |
377 | ||
378 | /* | |
25985edc | 379 | * Map buffer into kernel address-space if necessary. |
1da177e4 LT |
380 | */ |
381 | STATIC int | |
ce8e922c | 382 | _xfs_buf_map_pages( |
1da177e4 LT |
383 | xfs_buf_t *bp, |
384 | uint flags) | |
385 | { | |
0e6e847f | 386 | ASSERT(bp->b_flags & _XBF_PAGES); |
ce8e922c | 387 | if (bp->b_page_count == 1) { |
0e6e847f | 388 | /* A single page buffer is always mappable */ |
ce8e922c NS |
389 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; |
390 | bp->b_flags |= XBF_MAPPED; | |
391 | } else if (flags & XBF_MAPPED) { | |
a19fb380 DC |
392 | int retried = 0; |
393 | ||
394 | do { | |
395 | bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, | |
396 | -1, PAGE_KERNEL); | |
397 | if (bp->b_addr) | |
398 | break; | |
399 | vm_unmap_aliases(); | |
400 | } while (retried++ <= 1); | |
401 | ||
402 | if (!bp->b_addr) | |
1da177e4 | 403 | return -ENOMEM; |
ce8e922c NS |
404 | bp->b_addr += bp->b_offset; |
405 | bp->b_flags |= XBF_MAPPED; | |
1da177e4 LT |
406 | } |
407 | ||
408 | return 0; | |
409 | } | |
410 | ||
411 | /* | |
412 | * Finding and Reading Buffers | |
413 | */ | |
414 | ||
415 | /* | |
ce8e922c | 416 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 LT |
417 | * a given range of an inode. The buffer is returned |
418 | * locked. If other overlapping buffers exist, they are | |
419 | * released before the new buffer is created and locked, | |
420 | * which may imply that this call will block until those buffers | |
421 | * are unlocked. No I/O is implied by this call. | |
422 | */ | |
423 | xfs_buf_t * | |
ce8e922c | 424 | _xfs_buf_find( |
1da177e4 | 425 | xfs_buftarg_t *btp, /* block device target */ |
204ab25f | 426 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 427 | size_t isize, /* length of range */ |
ce8e922c NS |
428 | xfs_buf_flags_t flags, |
429 | xfs_buf_t *new_bp) | |
1da177e4 | 430 | { |
204ab25f | 431 | xfs_off_t range_base; |
1da177e4 | 432 | size_t range_length; |
74f75a0c DC |
433 | struct xfs_perag *pag; |
434 | struct rb_node **rbp; | |
435 | struct rb_node *parent; | |
436 | xfs_buf_t *bp; | |
1da177e4 LT |
437 | |
438 | range_base = (ioff << BBSHIFT); | |
439 | range_length = (isize << BBSHIFT); | |
440 | ||
441 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
ce8e922c | 442 | ASSERT(!(range_length < (1 << btp->bt_sshift))); |
204ab25f | 443 | ASSERT(!(range_base & (xfs_off_t)btp->bt_smask)); |
1da177e4 | 444 | |
74f75a0c DC |
445 | /* get tree root */ |
446 | pag = xfs_perag_get(btp->bt_mount, | |
447 | xfs_daddr_to_agno(btp->bt_mount, ioff)); | |
448 | ||
449 | /* walk tree */ | |
450 | spin_lock(&pag->pag_buf_lock); | |
451 | rbp = &pag->pag_buf_tree.rb_node; | |
452 | parent = NULL; | |
453 | bp = NULL; | |
454 | while (*rbp) { | |
455 | parent = *rbp; | |
456 | bp = rb_entry(parent, struct xfs_buf, b_rbnode); | |
457 | ||
458 | if (range_base < bp->b_file_offset) | |
459 | rbp = &(*rbp)->rb_left; | |
460 | else if (range_base > bp->b_file_offset) | |
461 | rbp = &(*rbp)->rb_right; | |
462 | else { | |
463 | /* | |
464 | * found a block offset match. If the range doesn't | |
465 | * match, the only way this is allowed is if the buffer | |
466 | * in the cache is stale and the transaction that made | |
467 | * it stale has not yet committed. i.e. we are | |
468 | * reallocating a busy extent. Skip this buffer and | |
469 | * continue searching to the right for an exact match. | |
470 | */ | |
471 | if (bp->b_buffer_length != range_length) { | |
472 | ASSERT(bp->b_flags & XBF_STALE); | |
473 | rbp = &(*rbp)->rb_right; | |
474 | continue; | |
475 | } | |
ce8e922c | 476 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
477 | goto found; |
478 | } | |
479 | } | |
480 | ||
481 | /* No match found */ | |
ce8e922c NS |
482 | if (new_bp) { |
483 | _xfs_buf_initialize(new_bp, btp, range_base, | |
1da177e4 | 484 | range_length, flags); |
74f75a0c DC |
485 | rb_link_node(&new_bp->b_rbnode, parent, rbp); |
486 | rb_insert_color(&new_bp->b_rbnode, &pag->pag_buf_tree); | |
487 | /* the buffer keeps the perag reference until it is freed */ | |
488 | new_bp->b_pag = pag; | |
489 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 490 | } else { |
ce8e922c | 491 | XFS_STATS_INC(xb_miss_locked); |
74f75a0c DC |
492 | spin_unlock(&pag->pag_buf_lock); |
493 | xfs_perag_put(pag); | |
1da177e4 | 494 | } |
ce8e922c | 495 | return new_bp; |
1da177e4 LT |
496 | |
497 | found: | |
74f75a0c DC |
498 | spin_unlock(&pag->pag_buf_lock); |
499 | xfs_perag_put(pag); | |
1da177e4 | 500 | |
0c842ad4 CH |
501 | if (!xfs_buf_trylock(bp)) { |
502 | if (flags & XBF_TRYLOCK) { | |
ce8e922c NS |
503 | xfs_buf_rele(bp); |
504 | XFS_STATS_INC(xb_busy_locked); | |
505 | return NULL; | |
1da177e4 | 506 | } |
0c842ad4 CH |
507 | xfs_buf_lock(bp); |
508 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 LT |
509 | } |
510 | ||
0e6e847f DC |
511 | /* |
512 | * if the buffer is stale, clear all the external state associated with | |
513 | * it. We need to keep flags such as how we allocated the buffer memory | |
514 | * intact here. | |
515 | */ | |
ce8e922c NS |
516 | if (bp->b_flags & XBF_STALE) { |
517 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
0e6e847f | 518 | bp->b_flags &= XBF_MAPPED | _XBF_KMEM | _XBF_PAGES; |
2f926587 | 519 | } |
0b1b213f CH |
520 | |
521 | trace_xfs_buf_find(bp, flags, _RET_IP_); | |
ce8e922c NS |
522 | XFS_STATS_INC(xb_get_locked); |
523 | return bp; | |
1da177e4 LT |
524 | } |
525 | ||
526 | /* | |
ce8e922c | 527 | * Assembles a buffer covering the specified range. |
1da177e4 LT |
528 | * Storage in memory for all portions of the buffer will be allocated, |
529 | * although backing storage may not be. | |
530 | */ | |
531 | xfs_buf_t * | |
6ad112bf | 532 | xfs_buf_get( |
1da177e4 | 533 | xfs_buftarg_t *target,/* target for buffer */ |
204ab25f | 534 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 535 | size_t isize, /* length of range */ |
ce8e922c | 536 | xfs_buf_flags_t flags) |
1da177e4 | 537 | { |
ce8e922c | 538 | xfs_buf_t *bp, *new_bp; |
0e6e847f | 539 | int error = 0; |
1da177e4 | 540 | |
ce8e922c NS |
541 | new_bp = xfs_buf_allocate(flags); |
542 | if (unlikely(!new_bp)) | |
1da177e4 LT |
543 | return NULL; |
544 | ||
ce8e922c NS |
545 | bp = _xfs_buf_find(target, ioff, isize, flags, new_bp); |
546 | if (bp == new_bp) { | |
0e6e847f | 547 | error = xfs_buf_allocate_memory(bp, flags); |
1da177e4 LT |
548 | if (error) |
549 | goto no_buffer; | |
550 | } else { | |
ce8e922c NS |
551 | xfs_buf_deallocate(new_bp); |
552 | if (unlikely(bp == NULL)) | |
1da177e4 LT |
553 | return NULL; |
554 | } | |
555 | ||
ce8e922c NS |
556 | if (!(bp->b_flags & XBF_MAPPED)) { |
557 | error = _xfs_buf_map_pages(bp, flags); | |
1da177e4 | 558 | if (unlikely(error)) { |
4f10700a DC |
559 | xfs_warn(target->bt_mount, |
560 | "%s: failed to map pages\n", __func__); | |
1da177e4 LT |
561 | goto no_buffer; |
562 | } | |
563 | } | |
564 | ||
ce8e922c | 565 | XFS_STATS_INC(xb_get); |
1da177e4 LT |
566 | |
567 | /* | |
568 | * Always fill in the block number now, the mapped cases can do | |
569 | * their own overlay of this later. | |
570 | */ | |
ce8e922c NS |
571 | bp->b_bn = ioff; |
572 | bp->b_count_desired = bp->b_buffer_length; | |
1da177e4 | 573 | |
0b1b213f | 574 | trace_xfs_buf_get(bp, flags, _RET_IP_); |
ce8e922c | 575 | return bp; |
1da177e4 LT |
576 | |
577 | no_buffer: | |
ce8e922c NS |
578 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
579 | xfs_buf_unlock(bp); | |
580 | xfs_buf_rele(bp); | |
1da177e4 LT |
581 | return NULL; |
582 | } | |
583 | ||
5d765b97 CH |
584 | STATIC int |
585 | _xfs_buf_read( | |
586 | xfs_buf_t *bp, | |
587 | xfs_buf_flags_t flags) | |
588 | { | |
589 | int status; | |
590 | ||
5d765b97 CH |
591 | ASSERT(!(flags & (XBF_DELWRI|XBF_WRITE))); |
592 | ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL); | |
593 | ||
1d5ae5df CH |
594 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_DELWRI | XBF_READ_AHEAD); |
595 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD); | |
5d765b97 CH |
596 | |
597 | status = xfs_buf_iorequest(bp); | |
5a52c2a5 | 598 | if (status || bp->b_error || (flags & XBF_ASYNC)) |
ec53d1db DC |
599 | return status; |
600 | return xfs_buf_iowait(bp); | |
5d765b97 CH |
601 | } |
602 | ||
1da177e4 | 603 | xfs_buf_t * |
6ad112bf | 604 | xfs_buf_read( |
1da177e4 | 605 | xfs_buftarg_t *target, |
204ab25f | 606 | xfs_off_t ioff, |
1da177e4 | 607 | size_t isize, |
ce8e922c | 608 | xfs_buf_flags_t flags) |
1da177e4 | 609 | { |
ce8e922c NS |
610 | xfs_buf_t *bp; |
611 | ||
612 | flags |= XBF_READ; | |
613 | ||
6ad112bf | 614 | bp = xfs_buf_get(target, ioff, isize, flags); |
ce8e922c | 615 | if (bp) { |
0b1b213f CH |
616 | trace_xfs_buf_read(bp, flags, _RET_IP_); |
617 | ||
ce8e922c | 618 | if (!XFS_BUF_ISDONE(bp)) { |
ce8e922c | 619 | XFS_STATS_INC(xb_get_read); |
5d765b97 | 620 | _xfs_buf_read(bp, flags); |
ce8e922c | 621 | } else if (flags & XBF_ASYNC) { |
1da177e4 LT |
622 | /* |
623 | * Read ahead call which is already satisfied, | |
624 | * drop the buffer | |
625 | */ | |
626 | goto no_buffer; | |
627 | } else { | |
1da177e4 | 628 | /* We do not want read in the flags */ |
ce8e922c | 629 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
630 | } |
631 | } | |
632 | ||
ce8e922c | 633 | return bp; |
1da177e4 LT |
634 | |
635 | no_buffer: | |
ce8e922c NS |
636 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
637 | xfs_buf_unlock(bp); | |
638 | xfs_buf_rele(bp); | |
1da177e4 LT |
639 | return NULL; |
640 | } | |
641 | ||
1da177e4 | 642 | /* |
ce8e922c NS |
643 | * If we are not low on memory then do the readahead in a deadlock |
644 | * safe manner. | |
1da177e4 LT |
645 | */ |
646 | void | |
ce8e922c | 647 | xfs_buf_readahead( |
1da177e4 | 648 | xfs_buftarg_t *target, |
204ab25f | 649 | xfs_off_t ioff, |
1a1a3e97 | 650 | size_t isize) |
1da177e4 | 651 | { |
0e6e847f | 652 | if (bdi_read_congested(target->bt_bdi)) |
1da177e4 LT |
653 | return; |
654 | ||
1a1a3e97 CH |
655 | xfs_buf_read(target, ioff, isize, |
656 | XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD|XBF_DONT_BLOCK); | |
1da177e4 LT |
657 | } |
658 | ||
5adc94c2 DC |
659 | /* |
660 | * Read an uncached buffer from disk. Allocates and returns a locked | |
661 | * buffer containing the disk contents or nothing. | |
662 | */ | |
663 | struct xfs_buf * | |
664 | xfs_buf_read_uncached( | |
665 | struct xfs_mount *mp, | |
666 | struct xfs_buftarg *target, | |
667 | xfs_daddr_t daddr, | |
668 | size_t length, | |
669 | int flags) | |
670 | { | |
671 | xfs_buf_t *bp; | |
672 | int error; | |
673 | ||
674 | bp = xfs_buf_get_uncached(target, length, flags); | |
675 | if (!bp) | |
676 | return NULL; | |
677 | ||
678 | /* set up the buffer for a read IO */ | |
5adc94c2 DC |
679 | XFS_BUF_SET_ADDR(bp, daddr); |
680 | XFS_BUF_READ(bp); | |
5adc94c2 DC |
681 | |
682 | xfsbdstrat(mp, bp); | |
1a1a3e97 | 683 | error = xfs_buf_iowait(bp); |
5adc94c2 DC |
684 | if (error || bp->b_error) { |
685 | xfs_buf_relse(bp); | |
686 | return NULL; | |
687 | } | |
688 | return bp; | |
1da177e4 LT |
689 | } |
690 | ||
691 | xfs_buf_t * | |
ce8e922c | 692 | xfs_buf_get_empty( |
1da177e4 LT |
693 | size_t len, |
694 | xfs_buftarg_t *target) | |
695 | { | |
ce8e922c | 696 | xfs_buf_t *bp; |
1da177e4 | 697 | |
ce8e922c NS |
698 | bp = xfs_buf_allocate(0); |
699 | if (bp) | |
700 | _xfs_buf_initialize(bp, target, 0, len, 0); | |
701 | return bp; | |
1da177e4 LT |
702 | } |
703 | ||
44396476 DC |
704 | /* |
705 | * Return a buffer allocated as an empty buffer and associated to external | |
706 | * memory via xfs_buf_associate_memory() back to it's empty state. | |
707 | */ | |
708 | void | |
709 | xfs_buf_set_empty( | |
710 | struct xfs_buf *bp, | |
711 | size_t len) | |
712 | { | |
713 | if (bp->b_pages) | |
714 | _xfs_buf_free_pages(bp); | |
715 | ||
716 | bp->b_pages = NULL; | |
717 | bp->b_page_count = 0; | |
718 | bp->b_addr = NULL; | |
719 | bp->b_file_offset = 0; | |
720 | bp->b_buffer_length = bp->b_count_desired = len; | |
721 | bp->b_bn = XFS_BUF_DADDR_NULL; | |
722 | bp->b_flags &= ~XBF_MAPPED; | |
723 | } | |
724 | ||
1da177e4 LT |
725 | static inline struct page * |
726 | mem_to_page( | |
727 | void *addr) | |
728 | { | |
9e2779fa | 729 | if ((!is_vmalloc_addr(addr))) { |
1da177e4 LT |
730 | return virt_to_page(addr); |
731 | } else { | |
732 | return vmalloc_to_page(addr); | |
733 | } | |
734 | } | |
735 | ||
736 | int | |
ce8e922c NS |
737 | xfs_buf_associate_memory( |
738 | xfs_buf_t *bp, | |
1da177e4 LT |
739 | void *mem, |
740 | size_t len) | |
741 | { | |
742 | int rval; | |
743 | int i = 0; | |
d1afb678 LM |
744 | unsigned long pageaddr; |
745 | unsigned long offset; | |
746 | size_t buflen; | |
1da177e4 LT |
747 | int page_count; |
748 | ||
0e6e847f | 749 | pageaddr = (unsigned long)mem & PAGE_MASK; |
d1afb678 | 750 | offset = (unsigned long)mem - pageaddr; |
0e6e847f DC |
751 | buflen = PAGE_ALIGN(len + offset); |
752 | page_count = buflen >> PAGE_SHIFT; | |
1da177e4 LT |
753 | |
754 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
755 | if (bp->b_pages) |
756 | _xfs_buf_free_pages(bp); | |
1da177e4 | 757 | |
ce8e922c NS |
758 | bp->b_pages = NULL; |
759 | bp->b_addr = mem; | |
1da177e4 | 760 | |
36fae17a | 761 | rval = _xfs_buf_get_pages(bp, page_count, XBF_DONT_BLOCK); |
1da177e4 LT |
762 | if (rval) |
763 | return rval; | |
764 | ||
ce8e922c | 765 | bp->b_offset = offset; |
d1afb678 LM |
766 | |
767 | for (i = 0; i < bp->b_page_count; i++) { | |
768 | bp->b_pages[i] = mem_to_page((void *)pageaddr); | |
0e6e847f | 769 | pageaddr += PAGE_SIZE; |
1da177e4 | 770 | } |
1da177e4 | 771 | |
d1afb678 LM |
772 | bp->b_count_desired = len; |
773 | bp->b_buffer_length = buflen; | |
ce8e922c | 774 | bp->b_flags |= XBF_MAPPED; |
1da177e4 LT |
775 | |
776 | return 0; | |
777 | } | |
778 | ||
779 | xfs_buf_t * | |
686865f7 DC |
780 | xfs_buf_get_uncached( |
781 | struct xfs_buftarg *target, | |
1da177e4 | 782 | size_t len, |
686865f7 | 783 | int flags) |
1da177e4 | 784 | { |
1fa40b01 CH |
785 | unsigned long page_count = PAGE_ALIGN(len) >> PAGE_SHIFT; |
786 | int error, i; | |
1da177e4 | 787 | xfs_buf_t *bp; |
1da177e4 | 788 | |
ce8e922c | 789 | bp = xfs_buf_allocate(0); |
1da177e4 LT |
790 | if (unlikely(bp == NULL)) |
791 | goto fail; | |
ce8e922c | 792 | _xfs_buf_initialize(bp, target, 0, len, 0); |
1da177e4 | 793 | |
1fa40b01 CH |
794 | error = _xfs_buf_get_pages(bp, page_count, 0); |
795 | if (error) | |
1da177e4 LT |
796 | goto fail_free_buf; |
797 | ||
1fa40b01 | 798 | for (i = 0; i < page_count; i++) { |
686865f7 | 799 | bp->b_pages[i] = alloc_page(xb_to_gfp(flags)); |
1fa40b01 CH |
800 | if (!bp->b_pages[i]) |
801 | goto fail_free_mem; | |
1da177e4 | 802 | } |
1fa40b01 | 803 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 804 | |
1fa40b01 CH |
805 | error = _xfs_buf_map_pages(bp, XBF_MAPPED); |
806 | if (unlikely(error)) { | |
4f10700a DC |
807 | xfs_warn(target->bt_mount, |
808 | "%s: failed to map pages\n", __func__); | |
1da177e4 | 809 | goto fail_free_mem; |
1fa40b01 | 810 | } |
1da177e4 | 811 | |
686865f7 | 812 | trace_xfs_buf_get_uncached(bp, _RET_IP_); |
1da177e4 | 813 | return bp; |
1fa40b01 | 814 | |
1da177e4 | 815 | fail_free_mem: |
1fa40b01 CH |
816 | while (--i >= 0) |
817 | __free_page(bp->b_pages[i]); | |
ca165b88 | 818 | _xfs_buf_free_pages(bp); |
1da177e4 | 819 | fail_free_buf: |
ca165b88 | 820 | xfs_buf_deallocate(bp); |
1da177e4 LT |
821 | fail: |
822 | return NULL; | |
823 | } | |
824 | ||
825 | /* | |
1da177e4 LT |
826 | * Increment reference count on buffer, to hold the buffer concurrently |
827 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
828 | * Must hold the buffer already to call this function. |
829 | */ | |
830 | void | |
ce8e922c NS |
831 | xfs_buf_hold( |
832 | xfs_buf_t *bp) | |
1da177e4 | 833 | { |
0b1b213f | 834 | trace_xfs_buf_hold(bp, _RET_IP_); |
ce8e922c | 835 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
836 | } |
837 | ||
838 | /* | |
ce8e922c NS |
839 | * Releases a hold on the specified buffer. If the |
840 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
841 | */ |
842 | void | |
ce8e922c NS |
843 | xfs_buf_rele( |
844 | xfs_buf_t *bp) | |
1da177e4 | 845 | { |
74f75a0c | 846 | struct xfs_perag *pag = bp->b_pag; |
1da177e4 | 847 | |
0b1b213f | 848 | trace_xfs_buf_rele(bp, _RET_IP_); |
1da177e4 | 849 | |
74f75a0c | 850 | if (!pag) { |
430cbeb8 | 851 | ASSERT(list_empty(&bp->b_lru)); |
74f75a0c | 852 | ASSERT(RB_EMPTY_NODE(&bp->b_rbnode)); |
fad3aa1e NS |
853 | if (atomic_dec_and_test(&bp->b_hold)) |
854 | xfs_buf_free(bp); | |
855 | return; | |
856 | } | |
857 | ||
74f75a0c | 858 | ASSERT(!RB_EMPTY_NODE(&bp->b_rbnode)); |
430cbeb8 | 859 | |
3790689f | 860 | ASSERT(atomic_read(&bp->b_hold) > 0); |
74f75a0c | 861 | if (atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock)) { |
bfc60177 | 862 | if (!(bp->b_flags & XBF_STALE) && |
430cbeb8 DC |
863 | atomic_read(&bp->b_lru_ref)) { |
864 | xfs_buf_lru_add(bp); | |
865 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 866 | } else { |
430cbeb8 | 867 | xfs_buf_lru_del(bp); |
ce8e922c | 868 | ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q))); |
74f75a0c DC |
869 | rb_erase(&bp->b_rbnode, &pag->pag_buf_tree); |
870 | spin_unlock(&pag->pag_buf_lock); | |
871 | xfs_perag_put(pag); | |
ce8e922c | 872 | xfs_buf_free(bp); |
1da177e4 LT |
873 | } |
874 | } | |
875 | } | |
876 | ||
877 | ||
878 | /* | |
0e6e847f | 879 | * Lock a buffer object, if it is not already locked. |
90810b9e DC |
880 | * |
881 | * If we come across a stale, pinned, locked buffer, we know that we are | |
882 | * being asked to lock a buffer that has been reallocated. Because it is | |
883 | * pinned, we know that the log has not been pushed to disk and hence it | |
884 | * will still be locked. Rather than continuing to have trylock attempts | |
885 | * fail until someone else pushes the log, push it ourselves before | |
886 | * returning. This means that the xfsaild will not get stuck trying | |
887 | * to push on stale inode buffers. | |
1da177e4 LT |
888 | */ |
889 | int | |
0c842ad4 CH |
890 | xfs_buf_trylock( |
891 | struct xfs_buf *bp) | |
1da177e4 LT |
892 | { |
893 | int locked; | |
894 | ||
ce8e922c | 895 | locked = down_trylock(&bp->b_sema) == 0; |
0b1b213f | 896 | if (locked) |
ce8e922c | 897 | XB_SET_OWNER(bp); |
90810b9e DC |
898 | else if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
899 | xfs_log_force(bp->b_target->bt_mount, 0); | |
0b1b213f | 900 | |
0c842ad4 CH |
901 | trace_xfs_buf_trylock(bp, _RET_IP_); |
902 | return locked; | |
1da177e4 | 903 | } |
1da177e4 LT |
904 | |
905 | /* | |
0e6e847f | 906 | * Lock a buffer object. |
ed3b4d6c DC |
907 | * |
908 | * If we come across a stale, pinned, locked buffer, we know that we | |
909 | * are being asked to lock a buffer that has been reallocated. Because | |
910 | * it is pinned, we know that the log has not been pushed to disk and | |
911 | * hence it will still be locked. Rather than sleeping until someone | |
912 | * else pushes the log, push it ourselves before trying to get the lock. | |
1da177e4 | 913 | */ |
ce8e922c NS |
914 | void |
915 | xfs_buf_lock( | |
0c842ad4 | 916 | struct xfs_buf *bp) |
1da177e4 | 917 | { |
0b1b213f CH |
918 | trace_xfs_buf_lock(bp, _RET_IP_); |
919 | ||
ed3b4d6c | 920 | if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
ebad861b | 921 | xfs_log_force(bp->b_target->bt_mount, 0); |
ce8e922c NS |
922 | down(&bp->b_sema); |
923 | XB_SET_OWNER(bp); | |
0b1b213f CH |
924 | |
925 | trace_xfs_buf_lock_done(bp, _RET_IP_); | |
1da177e4 LT |
926 | } |
927 | ||
928 | /* | |
ce8e922c | 929 | * Releases the lock on the buffer object. |
2f926587 | 930 | * If the buffer is marked delwri but is not queued, do so before we |
ce8e922c | 931 | * unlock the buffer as we need to set flags correctly. We also need to |
2f926587 DC |
932 | * take a reference for the delwri queue because the unlocker is going to |
933 | * drop their's and they don't know we just queued it. | |
1da177e4 LT |
934 | */ |
935 | void | |
ce8e922c | 936 | xfs_buf_unlock( |
0c842ad4 | 937 | struct xfs_buf *bp) |
1da177e4 | 938 | { |
ce8e922c NS |
939 | XB_CLEAR_OWNER(bp); |
940 | up(&bp->b_sema); | |
0b1b213f CH |
941 | |
942 | trace_xfs_buf_unlock(bp, _RET_IP_); | |
1da177e4 LT |
943 | } |
944 | ||
ce8e922c NS |
945 | STATIC void |
946 | xfs_buf_wait_unpin( | |
947 | xfs_buf_t *bp) | |
1da177e4 LT |
948 | { |
949 | DECLARE_WAITQUEUE (wait, current); | |
950 | ||
ce8e922c | 951 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
952 | return; |
953 | ||
ce8e922c | 954 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
955 | for (;;) { |
956 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 957 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 958 | break; |
7eaceacc | 959 | io_schedule(); |
1da177e4 | 960 | } |
ce8e922c | 961 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
962 | set_current_state(TASK_RUNNING); |
963 | } | |
964 | ||
965 | /* | |
966 | * Buffer Utility Routines | |
967 | */ | |
968 | ||
1da177e4 | 969 | STATIC void |
ce8e922c | 970 | xfs_buf_iodone_work( |
c4028958 | 971 | struct work_struct *work) |
1da177e4 | 972 | { |
c4028958 DH |
973 | xfs_buf_t *bp = |
974 | container_of(work, xfs_buf_t, b_iodone_work); | |
1da177e4 | 975 | |
80f6c29d | 976 | if (bp->b_iodone) |
ce8e922c NS |
977 | (*(bp->b_iodone))(bp); |
978 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 LT |
979 | xfs_buf_relse(bp); |
980 | } | |
981 | ||
982 | void | |
ce8e922c NS |
983 | xfs_buf_ioend( |
984 | xfs_buf_t *bp, | |
1da177e4 LT |
985 | int schedule) |
986 | { | |
0b1b213f CH |
987 | trace_xfs_buf_iodone(bp, _RET_IP_); |
988 | ||
77be55a5 | 989 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); |
ce8e922c NS |
990 | if (bp->b_error == 0) |
991 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 992 | |
ce8e922c | 993 | if ((bp->b_iodone) || (bp->b_flags & XBF_ASYNC)) { |
1da177e4 | 994 | if (schedule) { |
c4028958 | 995 | INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work); |
ce8e922c | 996 | queue_work(xfslogd_workqueue, &bp->b_iodone_work); |
1da177e4 | 997 | } else { |
c4028958 | 998 | xfs_buf_iodone_work(&bp->b_iodone_work); |
1da177e4 LT |
999 | } |
1000 | } else { | |
b4dd330b | 1001 | complete(&bp->b_iowait); |
1da177e4 LT |
1002 | } |
1003 | } | |
1004 | ||
1da177e4 | 1005 | void |
ce8e922c NS |
1006 | xfs_buf_ioerror( |
1007 | xfs_buf_t *bp, | |
1008 | int error) | |
1da177e4 LT |
1009 | { |
1010 | ASSERT(error >= 0 && error <= 0xffff); | |
ce8e922c | 1011 | bp->b_error = (unsigned short)error; |
0b1b213f | 1012 | trace_xfs_buf_ioerror(bp, error, _RET_IP_); |
1da177e4 LT |
1013 | } |
1014 | ||
1da177e4 | 1015 | int |
64e0bc7d CH |
1016 | xfs_bwrite( |
1017 | struct xfs_mount *mp, | |
5d765b97 | 1018 | struct xfs_buf *bp) |
1da177e4 | 1019 | { |
8c38366f | 1020 | int error; |
1da177e4 | 1021 | |
64e0bc7d | 1022 | bp->b_flags |= XBF_WRITE; |
8c38366f | 1023 | bp->b_flags &= ~(XBF_ASYNC | XBF_READ); |
1da177e4 | 1024 | |
5d765b97 | 1025 | xfs_buf_delwri_dequeue(bp); |
939d723b | 1026 | xfs_bdstrat_cb(bp); |
1da177e4 | 1027 | |
8c38366f CH |
1028 | error = xfs_buf_iowait(bp); |
1029 | if (error) | |
1030 | xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR); | |
1031 | xfs_buf_relse(bp); | |
64e0bc7d | 1032 | return error; |
5d765b97 | 1033 | } |
1da177e4 | 1034 | |
4e23471a CH |
1035 | /* |
1036 | * Called when we want to stop a buffer from getting written or read. | |
1a1a3e97 | 1037 | * We attach the EIO error, muck with its flags, and call xfs_buf_ioend |
4e23471a CH |
1038 | * so that the proper iodone callbacks get called. |
1039 | */ | |
1040 | STATIC int | |
1041 | xfs_bioerror( | |
1042 | xfs_buf_t *bp) | |
1043 | { | |
1044 | #ifdef XFSERRORDEBUG | |
1045 | ASSERT(XFS_BUF_ISREAD(bp) || bp->b_iodone); | |
1046 | #endif | |
1047 | ||
1048 | /* | |
1049 | * No need to wait until the buffer is unpinned, we aren't flushing it. | |
1050 | */ | |
5a52c2a5 | 1051 | xfs_buf_ioerror(bp, EIO); |
4e23471a CH |
1052 | |
1053 | /* | |
1a1a3e97 | 1054 | * We're calling xfs_buf_ioend, so delete XBF_DONE flag. |
4e23471a CH |
1055 | */ |
1056 | XFS_BUF_UNREAD(bp); | |
61551f1e | 1057 | xfs_buf_delwri_dequeue(bp); |
4e23471a CH |
1058 | XFS_BUF_UNDONE(bp); |
1059 | XFS_BUF_STALE(bp); | |
1060 | ||
1a1a3e97 | 1061 | xfs_buf_ioend(bp, 0); |
4e23471a CH |
1062 | |
1063 | return EIO; | |
1064 | } | |
1065 | ||
1066 | /* | |
1067 | * Same as xfs_bioerror, except that we are releasing the buffer | |
1a1a3e97 | 1068 | * here ourselves, and avoiding the xfs_buf_ioend call. |
4e23471a CH |
1069 | * This is meant for userdata errors; metadata bufs come with |
1070 | * iodone functions attached, so that we can track down errors. | |
1071 | */ | |
1072 | STATIC int | |
1073 | xfs_bioerror_relse( | |
1074 | struct xfs_buf *bp) | |
1075 | { | |
ed43233b | 1076 | int64_t fl = bp->b_flags; |
4e23471a CH |
1077 | /* |
1078 | * No need to wait until the buffer is unpinned. | |
1079 | * We aren't flushing it. | |
1080 | * | |
1081 | * chunkhold expects B_DONE to be set, whether | |
1082 | * we actually finish the I/O or not. We don't want to | |
1083 | * change that interface. | |
1084 | */ | |
1085 | XFS_BUF_UNREAD(bp); | |
61551f1e | 1086 | xfs_buf_delwri_dequeue(bp); |
4e23471a CH |
1087 | XFS_BUF_DONE(bp); |
1088 | XFS_BUF_STALE(bp); | |
cb669ca5 | 1089 | bp->b_iodone = NULL; |
0cadda1c | 1090 | if (!(fl & XBF_ASYNC)) { |
4e23471a CH |
1091 | /* |
1092 | * Mark b_error and B_ERROR _both_. | |
1093 | * Lot's of chunkcache code assumes that. | |
1094 | * There's no reason to mark error for | |
1095 | * ASYNC buffers. | |
1096 | */ | |
5a52c2a5 | 1097 | xfs_buf_ioerror(bp, EIO); |
4e23471a CH |
1098 | XFS_BUF_FINISH_IOWAIT(bp); |
1099 | } else { | |
1100 | xfs_buf_relse(bp); | |
1101 | } | |
1102 | ||
1103 | return EIO; | |
1104 | } | |
1105 | ||
1106 | ||
1107 | /* | |
1108 | * All xfs metadata buffers except log state machine buffers | |
1109 | * get this attached as their b_bdstrat callback function. | |
1110 | * This is so that we can catch a buffer | |
1111 | * after prematurely unpinning it to forcibly shutdown the filesystem. | |
1112 | */ | |
1113 | int | |
1114 | xfs_bdstrat_cb( | |
1115 | struct xfs_buf *bp) | |
1116 | { | |
ebad861b | 1117 | if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) { |
4e23471a CH |
1118 | trace_xfs_bdstrat_shut(bp, _RET_IP_); |
1119 | /* | |
1120 | * Metadata write that didn't get logged but | |
1121 | * written delayed anyway. These aren't associated | |
1122 | * with a transaction, and can be ignored. | |
1123 | */ | |
1124 | if (!bp->b_iodone && !XFS_BUF_ISREAD(bp)) | |
1125 | return xfs_bioerror_relse(bp); | |
1126 | else | |
1127 | return xfs_bioerror(bp); | |
1128 | } | |
1129 | ||
1130 | xfs_buf_iorequest(bp); | |
1131 | return 0; | |
1132 | } | |
1133 | ||
1134 | /* | |
1135 | * Wrapper around bdstrat so that we can stop data from going to disk in case | |
1136 | * we are shutting down the filesystem. Typically user data goes thru this | |
1137 | * path; one of the exceptions is the superblock. | |
1138 | */ | |
1139 | void | |
1140 | xfsbdstrat( | |
1141 | struct xfs_mount *mp, | |
1142 | struct xfs_buf *bp) | |
1143 | { | |
1144 | if (XFS_FORCED_SHUTDOWN(mp)) { | |
1145 | trace_xfs_bdstrat_shut(bp, _RET_IP_); | |
1146 | xfs_bioerror_relse(bp); | |
1147 | return; | |
1148 | } | |
1149 | ||
1150 | xfs_buf_iorequest(bp); | |
1151 | } | |
1152 | ||
b8f82a4a | 1153 | STATIC void |
ce8e922c NS |
1154 | _xfs_buf_ioend( |
1155 | xfs_buf_t *bp, | |
1da177e4 LT |
1156 | int schedule) |
1157 | { | |
0e6e847f | 1158 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) |
ce8e922c | 1159 | xfs_buf_ioend(bp, schedule); |
1da177e4 LT |
1160 | } |
1161 | ||
782e3b3b | 1162 | STATIC void |
ce8e922c | 1163 | xfs_buf_bio_end_io( |
1da177e4 | 1164 | struct bio *bio, |
1da177e4 LT |
1165 | int error) |
1166 | { | |
ce8e922c | 1167 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1da177e4 | 1168 | |
cfbe5267 | 1169 | xfs_buf_ioerror(bp, -error); |
1da177e4 | 1170 | |
73c77e2c JB |
1171 | if (!error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ)) |
1172 | invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp)); | |
1173 | ||
ce8e922c | 1174 | _xfs_buf_ioend(bp, 1); |
1da177e4 | 1175 | bio_put(bio); |
1da177e4 LT |
1176 | } |
1177 | ||
1178 | STATIC void | |
ce8e922c NS |
1179 | _xfs_buf_ioapply( |
1180 | xfs_buf_t *bp) | |
1da177e4 | 1181 | { |
a9759f2d | 1182 | int rw, map_i, total_nr_pages, nr_pages; |
1da177e4 | 1183 | struct bio *bio; |
ce8e922c NS |
1184 | int offset = bp->b_offset; |
1185 | int size = bp->b_count_desired; | |
1186 | sector_t sector = bp->b_bn; | |
1da177e4 | 1187 | |
ce8e922c | 1188 | total_nr_pages = bp->b_page_count; |
1da177e4 LT |
1189 | map_i = 0; |
1190 | ||
1d5ae5df CH |
1191 | if (bp->b_flags & XBF_WRITE) { |
1192 | if (bp->b_flags & XBF_SYNCIO) | |
1193 | rw = WRITE_SYNC; | |
1194 | else | |
1195 | rw = WRITE; | |
1196 | if (bp->b_flags & XBF_FUA) | |
1197 | rw |= REQ_FUA; | |
1198 | if (bp->b_flags & XBF_FLUSH) | |
1199 | rw |= REQ_FLUSH; | |
1200 | } else if (bp->b_flags & XBF_READ_AHEAD) { | |
1201 | rw = READA; | |
51bdd706 | 1202 | } else { |
1d5ae5df | 1203 | rw = READ; |
f538d4da CH |
1204 | } |
1205 | ||
34951f5c CH |
1206 | /* we only use the buffer cache for meta-data */ |
1207 | rw |= REQ_META; | |
1208 | ||
1da177e4 | 1209 | next_chunk: |
ce8e922c | 1210 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1211 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1212 | if (nr_pages > total_nr_pages) | |
1213 | nr_pages = total_nr_pages; | |
1214 | ||
1215 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1216 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1217 | bio->bi_sector = sector; |
ce8e922c NS |
1218 | bio->bi_end_io = xfs_buf_bio_end_io; |
1219 | bio->bi_private = bp; | |
1da177e4 | 1220 | |
0e6e847f | 1221 | |
1da177e4 | 1222 | for (; size && nr_pages; nr_pages--, map_i++) { |
0e6e847f | 1223 | int rbytes, nbytes = PAGE_SIZE - offset; |
1da177e4 LT |
1224 | |
1225 | if (nbytes > size) | |
1226 | nbytes = size; | |
1227 | ||
ce8e922c NS |
1228 | rbytes = bio_add_page(bio, bp->b_pages[map_i], nbytes, offset); |
1229 | if (rbytes < nbytes) | |
1da177e4 LT |
1230 | break; |
1231 | ||
1232 | offset = 0; | |
1233 | sector += nbytes >> BBSHIFT; | |
1234 | size -= nbytes; | |
1235 | total_nr_pages--; | |
1236 | } | |
1237 | ||
1da177e4 | 1238 | if (likely(bio->bi_size)) { |
73c77e2c JB |
1239 | if (xfs_buf_is_vmapped(bp)) { |
1240 | flush_kernel_vmap_range(bp->b_addr, | |
1241 | xfs_buf_vmap_len(bp)); | |
1242 | } | |
1da177e4 LT |
1243 | submit_bio(rw, bio); |
1244 | if (size) | |
1245 | goto next_chunk; | |
1246 | } else { | |
ce8e922c | 1247 | xfs_buf_ioerror(bp, EIO); |
ec53d1db | 1248 | bio_put(bio); |
1da177e4 LT |
1249 | } |
1250 | } | |
1251 | ||
1da177e4 | 1252 | int |
ce8e922c NS |
1253 | xfs_buf_iorequest( |
1254 | xfs_buf_t *bp) | |
1da177e4 | 1255 | { |
0b1b213f | 1256 | trace_xfs_buf_iorequest(bp, _RET_IP_); |
1da177e4 | 1257 | |
375ec69d | 1258 | ASSERT(!(bp->b_flags & XBF_DELWRI)); |
1da177e4 | 1259 | |
375ec69d | 1260 | if (bp->b_flags & XBF_WRITE) |
ce8e922c | 1261 | xfs_buf_wait_unpin(bp); |
ce8e922c | 1262 | xfs_buf_hold(bp); |
1da177e4 LT |
1263 | |
1264 | /* Set the count to 1 initially, this will stop an I/O | |
1265 | * completion callout which happens before we have started | |
ce8e922c | 1266 | * all the I/O from calling xfs_buf_ioend too early. |
1da177e4 | 1267 | */ |
ce8e922c NS |
1268 | atomic_set(&bp->b_io_remaining, 1); |
1269 | _xfs_buf_ioapply(bp); | |
1270 | _xfs_buf_ioend(bp, 0); | |
1da177e4 | 1271 | |
ce8e922c | 1272 | xfs_buf_rele(bp); |
1da177e4 LT |
1273 | return 0; |
1274 | } | |
1275 | ||
1276 | /* | |
ce8e922c NS |
1277 | * Waits for I/O to complete on the buffer supplied. |
1278 | * It returns immediately if no I/O is pending. | |
1279 | * It returns the I/O error code, if any, or 0 if there was no error. | |
1da177e4 LT |
1280 | */ |
1281 | int | |
ce8e922c NS |
1282 | xfs_buf_iowait( |
1283 | xfs_buf_t *bp) | |
1da177e4 | 1284 | { |
0b1b213f CH |
1285 | trace_xfs_buf_iowait(bp, _RET_IP_); |
1286 | ||
b4dd330b | 1287 | wait_for_completion(&bp->b_iowait); |
0b1b213f CH |
1288 | |
1289 | trace_xfs_buf_iowait_done(bp, _RET_IP_); | |
ce8e922c | 1290 | return bp->b_error; |
1da177e4 LT |
1291 | } |
1292 | ||
ce8e922c NS |
1293 | xfs_caddr_t |
1294 | xfs_buf_offset( | |
1295 | xfs_buf_t *bp, | |
1da177e4 LT |
1296 | size_t offset) |
1297 | { | |
1298 | struct page *page; | |
1299 | ||
ce8e922c | 1300 | if (bp->b_flags & XBF_MAPPED) |
62926044 | 1301 | return bp->b_addr + offset; |
1da177e4 | 1302 | |
ce8e922c | 1303 | offset += bp->b_offset; |
0e6e847f DC |
1304 | page = bp->b_pages[offset >> PAGE_SHIFT]; |
1305 | return (xfs_caddr_t)page_address(page) + (offset & (PAGE_SIZE-1)); | |
1da177e4 LT |
1306 | } |
1307 | ||
1308 | /* | |
1da177e4 LT |
1309 | * Move data into or out of a buffer. |
1310 | */ | |
1311 | void | |
ce8e922c NS |
1312 | xfs_buf_iomove( |
1313 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1314 | size_t boff, /* starting buffer offset */ |
1315 | size_t bsize, /* length to copy */ | |
b9c48649 | 1316 | void *data, /* data address */ |
ce8e922c | 1317 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 LT |
1318 | { |
1319 | size_t bend, cpoff, csize; | |
1320 | struct page *page; | |
1321 | ||
1322 | bend = boff + bsize; | |
1323 | while (boff < bend) { | |
ce8e922c NS |
1324 | page = bp->b_pages[xfs_buf_btoct(boff + bp->b_offset)]; |
1325 | cpoff = xfs_buf_poff(boff + bp->b_offset); | |
1da177e4 | 1326 | csize = min_t(size_t, |
0e6e847f | 1327 | PAGE_SIZE-cpoff, bp->b_count_desired-boff); |
1da177e4 | 1328 | |
0e6e847f | 1329 | ASSERT(((csize + cpoff) <= PAGE_SIZE)); |
1da177e4 LT |
1330 | |
1331 | switch (mode) { | |
ce8e922c | 1332 | case XBRW_ZERO: |
1da177e4 LT |
1333 | memset(page_address(page) + cpoff, 0, csize); |
1334 | break; | |
ce8e922c | 1335 | case XBRW_READ: |
1da177e4 LT |
1336 | memcpy(data, page_address(page) + cpoff, csize); |
1337 | break; | |
ce8e922c | 1338 | case XBRW_WRITE: |
1da177e4 LT |
1339 | memcpy(page_address(page) + cpoff, data, csize); |
1340 | } | |
1341 | ||
1342 | boff += csize; | |
1343 | data += csize; | |
1344 | } | |
1345 | } | |
1346 | ||
1347 | /* | |
ce8e922c | 1348 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1349 | */ |
1350 | ||
1351 | /* | |
430cbeb8 DC |
1352 | * Wait for any bufs with callbacks that have been submitted but have not yet |
1353 | * returned. These buffers will have an elevated hold count, so wait on those | |
1354 | * while freeing all the buffers only held by the LRU. | |
1da177e4 LT |
1355 | */ |
1356 | void | |
1357 | xfs_wait_buftarg( | |
74f75a0c | 1358 | struct xfs_buftarg *btp) |
1da177e4 | 1359 | { |
430cbeb8 DC |
1360 | struct xfs_buf *bp; |
1361 | ||
1362 | restart: | |
1363 | spin_lock(&btp->bt_lru_lock); | |
1364 | while (!list_empty(&btp->bt_lru)) { | |
1365 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1366 | if (atomic_read(&bp->b_hold) > 1) { | |
1367 | spin_unlock(&btp->bt_lru_lock); | |
26af6552 | 1368 | delay(100); |
430cbeb8 | 1369 | goto restart; |
1da177e4 | 1370 | } |
430cbeb8 DC |
1371 | /* |
1372 | * clear the LRU reference count so the bufer doesn't get | |
1373 | * ignored in xfs_buf_rele(). | |
1374 | */ | |
1375 | atomic_set(&bp->b_lru_ref, 0); | |
1376 | spin_unlock(&btp->bt_lru_lock); | |
1377 | xfs_buf_rele(bp); | |
1378 | spin_lock(&btp->bt_lru_lock); | |
1da177e4 | 1379 | } |
430cbeb8 | 1380 | spin_unlock(&btp->bt_lru_lock); |
1da177e4 LT |
1381 | } |
1382 | ||
ff57ab21 DC |
1383 | int |
1384 | xfs_buftarg_shrink( | |
1385 | struct shrinker *shrink, | |
1495f230 | 1386 | struct shrink_control *sc) |
a6867a68 | 1387 | { |
ff57ab21 DC |
1388 | struct xfs_buftarg *btp = container_of(shrink, |
1389 | struct xfs_buftarg, bt_shrinker); | |
430cbeb8 | 1390 | struct xfs_buf *bp; |
1495f230 | 1391 | int nr_to_scan = sc->nr_to_scan; |
430cbeb8 DC |
1392 | LIST_HEAD(dispose); |
1393 | ||
1394 | if (!nr_to_scan) | |
1395 | return btp->bt_lru_nr; | |
1396 | ||
1397 | spin_lock(&btp->bt_lru_lock); | |
1398 | while (!list_empty(&btp->bt_lru)) { | |
1399 | if (nr_to_scan-- <= 0) | |
1400 | break; | |
1401 | ||
1402 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1403 | ||
1404 | /* | |
1405 | * Decrement the b_lru_ref count unless the value is already | |
1406 | * zero. If the value is already zero, we need to reclaim the | |
1407 | * buffer, otherwise it gets another trip through the LRU. | |
1408 | */ | |
1409 | if (!atomic_add_unless(&bp->b_lru_ref, -1, 0)) { | |
1410 | list_move_tail(&bp->b_lru, &btp->bt_lru); | |
1411 | continue; | |
1412 | } | |
1413 | ||
1414 | /* | |
1415 | * remove the buffer from the LRU now to avoid needing another | |
1416 | * lock round trip inside xfs_buf_rele(). | |
1417 | */ | |
1418 | list_move(&bp->b_lru, &dispose); | |
1419 | btp->bt_lru_nr--; | |
ff57ab21 | 1420 | } |
430cbeb8 DC |
1421 | spin_unlock(&btp->bt_lru_lock); |
1422 | ||
1423 | while (!list_empty(&dispose)) { | |
1424 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); | |
1425 | list_del_init(&bp->b_lru); | |
1426 | xfs_buf_rele(bp); | |
1427 | } | |
1428 | ||
1429 | return btp->bt_lru_nr; | |
a6867a68 DC |
1430 | } |
1431 | ||
1da177e4 LT |
1432 | void |
1433 | xfs_free_buftarg( | |
b7963133 CH |
1434 | struct xfs_mount *mp, |
1435 | struct xfs_buftarg *btp) | |
1da177e4 | 1436 | { |
ff57ab21 DC |
1437 | unregister_shrinker(&btp->bt_shrinker); |
1438 | ||
1da177e4 | 1439 | xfs_flush_buftarg(btp, 1); |
b7963133 CH |
1440 | if (mp->m_flags & XFS_MOUNT_BARRIER) |
1441 | xfs_blkdev_issue_flush(btp); | |
a6867a68 | 1442 | |
a6867a68 | 1443 | kthread_stop(btp->bt_task); |
f0e2d93c | 1444 | kmem_free(btp); |
1da177e4 LT |
1445 | } |
1446 | ||
1da177e4 LT |
1447 | STATIC int |
1448 | xfs_setsize_buftarg_flags( | |
1449 | xfs_buftarg_t *btp, | |
1450 | unsigned int blocksize, | |
1451 | unsigned int sectorsize, | |
1452 | int verbose) | |
1453 | { | |
ce8e922c NS |
1454 | btp->bt_bsize = blocksize; |
1455 | btp->bt_sshift = ffs(sectorsize) - 1; | |
1456 | btp->bt_smask = sectorsize - 1; | |
1da177e4 | 1457 | |
ce8e922c | 1458 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
4f10700a DC |
1459 | xfs_warn(btp->bt_mount, |
1460 | "Cannot set_blocksize to %u on device %s\n", | |
c35a549c | 1461 | sectorsize, xfs_buf_target_name(btp)); |
1da177e4 LT |
1462 | return EINVAL; |
1463 | } | |
1464 | ||
1da177e4 LT |
1465 | return 0; |
1466 | } | |
1467 | ||
1468 | /* | |
ce8e922c NS |
1469 | * When allocating the initial buffer target we have not yet |
1470 | * read in the superblock, so don't know what sized sectors | |
1471 | * are being used is at this early stage. Play safe. | |
1472 | */ | |
1da177e4 LT |
1473 | STATIC int |
1474 | xfs_setsize_buftarg_early( | |
1475 | xfs_buftarg_t *btp, | |
1476 | struct block_device *bdev) | |
1477 | { | |
1478 | return xfs_setsize_buftarg_flags(btp, | |
0e6e847f | 1479 | PAGE_SIZE, bdev_logical_block_size(bdev), 0); |
1da177e4 LT |
1480 | } |
1481 | ||
1482 | int | |
1483 | xfs_setsize_buftarg( | |
1484 | xfs_buftarg_t *btp, | |
1485 | unsigned int blocksize, | |
1486 | unsigned int sectorsize) | |
1487 | { | |
1488 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | |
1489 | } | |
1490 | ||
a6867a68 DC |
1491 | STATIC int |
1492 | xfs_alloc_delwrite_queue( | |
e2a07812 JE |
1493 | xfs_buftarg_t *btp, |
1494 | const char *fsname) | |
a6867a68 | 1495 | { |
a6867a68 | 1496 | INIT_LIST_HEAD(&btp->bt_delwrite_queue); |
007c61c6 | 1497 | spin_lock_init(&btp->bt_delwrite_lock); |
a6867a68 | 1498 | btp->bt_flags = 0; |
e2a07812 | 1499 | btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd/%s", fsname); |
ff57ab21 DC |
1500 | if (IS_ERR(btp->bt_task)) |
1501 | return PTR_ERR(btp->bt_task); | |
1502 | return 0; | |
a6867a68 DC |
1503 | } |
1504 | ||
1da177e4 LT |
1505 | xfs_buftarg_t * |
1506 | xfs_alloc_buftarg( | |
ebad861b | 1507 | struct xfs_mount *mp, |
1da177e4 | 1508 | struct block_device *bdev, |
e2a07812 JE |
1509 | int external, |
1510 | const char *fsname) | |
1da177e4 LT |
1511 | { |
1512 | xfs_buftarg_t *btp; | |
1513 | ||
1514 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP); | |
1515 | ||
ebad861b | 1516 | btp->bt_mount = mp; |
ce8e922c NS |
1517 | btp->bt_dev = bdev->bd_dev; |
1518 | btp->bt_bdev = bdev; | |
0e6e847f DC |
1519 | btp->bt_bdi = blk_get_backing_dev_info(bdev); |
1520 | if (!btp->bt_bdi) | |
1521 | goto error; | |
1522 | ||
430cbeb8 DC |
1523 | INIT_LIST_HEAD(&btp->bt_lru); |
1524 | spin_lock_init(&btp->bt_lru_lock); | |
1da177e4 LT |
1525 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1526 | goto error; | |
e2a07812 | 1527 | if (xfs_alloc_delwrite_queue(btp, fsname)) |
a6867a68 | 1528 | goto error; |
ff57ab21 DC |
1529 | btp->bt_shrinker.shrink = xfs_buftarg_shrink; |
1530 | btp->bt_shrinker.seeks = DEFAULT_SEEKS; | |
1531 | register_shrinker(&btp->bt_shrinker); | |
1da177e4 LT |
1532 | return btp; |
1533 | ||
1534 | error: | |
f0e2d93c | 1535 | kmem_free(btp); |
1da177e4 LT |
1536 | return NULL; |
1537 | } | |
1538 | ||
1539 | ||
1540 | /* | |
ce8e922c | 1541 | * Delayed write buffer handling |
1da177e4 | 1542 | */ |
61551f1e | 1543 | void |
ce8e922c | 1544 | xfs_buf_delwri_queue( |
527cfdf1 | 1545 | xfs_buf_t *bp) |
1da177e4 | 1546 | { |
ce8e922c NS |
1547 | struct list_head *dwq = &bp->b_target->bt_delwrite_queue; |
1548 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; | |
a6867a68 | 1549 | |
0b1b213f CH |
1550 | trace_xfs_buf_delwri_queue(bp, _RET_IP_); |
1551 | ||
5a8ee6ba | 1552 | ASSERT(!(bp->b_flags & XBF_READ)); |
1da177e4 | 1553 | |
a6867a68 | 1554 | spin_lock(dwlk); |
ce8e922c | 1555 | if (!list_empty(&bp->b_list)) { |
5a8ee6ba | 1556 | /* if already in the queue, move it to the tail */ |
ce8e922c | 1557 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); |
5a8ee6ba CH |
1558 | list_move_tail(&bp->b_list, dwq); |
1559 | } else { | |
c9c12971 | 1560 | /* start xfsbufd as it is about to have something to do */ |
5a8ee6ba CH |
1561 | if (list_empty(dwq)) |
1562 | wake_up_process(bp->b_target->bt_task); | |
c9c12971 | 1563 | |
5a8ee6ba CH |
1564 | atomic_inc(&bp->b_hold); |
1565 | bp->b_flags |= XBF_DELWRI | _XBF_DELWRI_Q | XBF_ASYNC; | |
1566 | list_add_tail(&bp->b_list, dwq); | |
1567 | } | |
ce8e922c | 1568 | bp->b_queuetime = jiffies; |
a6867a68 | 1569 | spin_unlock(dwlk); |
1da177e4 LT |
1570 | } |
1571 | ||
1572 | void | |
ce8e922c NS |
1573 | xfs_buf_delwri_dequeue( |
1574 | xfs_buf_t *bp) | |
1da177e4 | 1575 | { |
ce8e922c | 1576 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; |
1da177e4 LT |
1577 | int dequeued = 0; |
1578 | ||
a6867a68 | 1579 | spin_lock(dwlk); |
ce8e922c NS |
1580 | if ((bp->b_flags & XBF_DELWRI) && !list_empty(&bp->b_list)) { |
1581 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1582 | list_del_init(&bp->b_list); | |
1da177e4 LT |
1583 | dequeued = 1; |
1584 | } | |
ce8e922c | 1585 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); |
a6867a68 | 1586 | spin_unlock(dwlk); |
1da177e4 LT |
1587 | |
1588 | if (dequeued) | |
ce8e922c | 1589 | xfs_buf_rele(bp); |
1da177e4 | 1590 | |
0b1b213f | 1591 | trace_xfs_buf_delwri_dequeue(bp, _RET_IP_); |
1da177e4 LT |
1592 | } |
1593 | ||
d808f617 DC |
1594 | /* |
1595 | * If a delwri buffer needs to be pushed before it has aged out, then promote | |
1596 | * it to the head of the delwri queue so that it will be flushed on the next | |
1597 | * xfsbufd run. We do this by resetting the queuetime of the buffer to be older | |
1598 | * than the age currently needed to flush the buffer. Hence the next time the | |
1599 | * xfsbufd sees it is guaranteed to be considered old enough to flush. | |
1600 | */ | |
1601 | void | |
1602 | xfs_buf_delwri_promote( | |
1603 | struct xfs_buf *bp) | |
1604 | { | |
1605 | struct xfs_buftarg *btp = bp->b_target; | |
1606 | long age = xfs_buf_age_centisecs * msecs_to_jiffies(10) + 1; | |
1607 | ||
1608 | ASSERT(bp->b_flags & XBF_DELWRI); | |
1609 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1610 | ||
1611 | /* | |
1612 | * Check the buffer age before locking the delayed write queue as we | |
1613 | * don't need to promote buffers that are already past the flush age. | |
1614 | */ | |
1615 | if (bp->b_queuetime < jiffies - age) | |
1616 | return; | |
1617 | bp->b_queuetime = jiffies - age; | |
1618 | spin_lock(&btp->bt_delwrite_lock); | |
1619 | list_move(&bp->b_list, &btp->bt_delwrite_queue); | |
1620 | spin_unlock(&btp->bt_delwrite_lock); | |
1621 | } | |
1622 | ||
1da177e4 | 1623 | STATIC void |
ce8e922c | 1624 | xfs_buf_runall_queues( |
1da177e4 LT |
1625 | struct workqueue_struct *queue) |
1626 | { | |
1627 | flush_workqueue(queue); | |
1628 | } | |
1629 | ||
585e6d88 DC |
1630 | /* |
1631 | * Move as many buffers as specified to the supplied list | |
1632 | * idicating if we skipped any buffers to prevent deadlocks. | |
1633 | */ | |
1634 | STATIC int | |
1635 | xfs_buf_delwri_split( | |
1636 | xfs_buftarg_t *target, | |
1637 | struct list_head *list, | |
5e6a07df | 1638 | unsigned long age) |
585e6d88 DC |
1639 | { |
1640 | xfs_buf_t *bp, *n; | |
1641 | struct list_head *dwq = &target->bt_delwrite_queue; | |
1642 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1643 | int skipped = 0; | |
5e6a07df | 1644 | int force; |
585e6d88 | 1645 | |
5e6a07df | 1646 | force = test_and_clear_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
585e6d88 DC |
1647 | INIT_LIST_HEAD(list); |
1648 | spin_lock(dwlk); | |
1649 | list_for_each_entry_safe(bp, n, dwq, b_list) { | |
585e6d88 DC |
1650 | ASSERT(bp->b_flags & XBF_DELWRI); |
1651 | ||
811e64c7 | 1652 | if (!xfs_buf_ispinned(bp) && xfs_buf_trylock(bp)) { |
5e6a07df | 1653 | if (!force && |
585e6d88 DC |
1654 | time_before(jiffies, bp->b_queuetime + age)) { |
1655 | xfs_buf_unlock(bp); | |
1656 | break; | |
1657 | } | |
1658 | ||
1d5ae5df | 1659 | bp->b_flags &= ~(XBF_DELWRI | _XBF_DELWRI_Q); |
585e6d88 DC |
1660 | bp->b_flags |= XBF_WRITE; |
1661 | list_move_tail(&bp->b_list, list); | |
bfe27419 | 1662 | trace_xfs_buf_delwri_split(bp, _RET_IP_); |
585e6d88 DC |
1663 | } else |
1664 | skipped++; | |
1665 | } | |
1666 | spin_unlock(dwlk); | |
1667 | ||
1668 | return skipped; | |
1669 | ||
1670 | } | |
1671 | ||
089716aa DC |
1672 | /* |
1673 | * Compare function is more complex than it needs to be because | |
1674 | * the return value is only 32 bits and we are doing comparisons | |
1675 | * on 64 bit values | |
1676 | */ | |
1677 | static int | |
1678 | xfs_buf_cmp( | |
1679 | void *priv, | |
1680 | struct list_head *a, | |
1681 | struct list_head *b) | |
1682 | { | |
1683 | struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list); | |
1684 | struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); | |
1685 | xfs_daddr_t diff; | |
1686 | ||
1687 | diff = ap->b_bn - bp->b_bn; | |
1688 | if (diff < 0) | |
1689 | return -1; | |
1690 | if (diff > 0) | |
1691 | return 1; | |
1692 | return 0; | |
1693 | } | |
1694 | ||
1da177e4 | 1695 | STATIC int |
23ea4032 | 1696 | xfsbufd( |
585e6d88 | 1697 | void *data) |
1da177e4 | 1698 | { |
089716aa | 1699 | xfs_buftarg_t *target = (xfs_buftarg_t *)data; |
1da177e4 | 1700 | |
1da177e4 LT |
1701 | current->flags |= PF_MEMALLOC; |
1702 | ||
978c7b2f RW |
1703 | set_freezable(); |
1704 | ||
1da177e4 | 1705 | do { |
c9c12971 DC |
1706 | long age = xfs_buf_age_centisecs * msecs_to_jiffies(10); |
1707 | long tout = xfs_buf_timer_centisecs * msecs_to_jiffies(10); | |
089716aa | 1708 | struct list_head tmp; |
a1b7ea5d | 1709 | struct blk_plug plug; |
c9c12971 | 1710 | |
3e1d1d28 | 1711 | if (unlikely(freezing(current))) { |
ce8e922c | 1712 | set_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
3e1d1d28 | 1713 | refrigerator(); |
abd0cf7a | 1714 | } else { |
ce8e922c | 1715 | clear_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
abd0cf7a | 1716 | } |
1da177e4 | 1717 | |
c9c12971 DC |
1718 | /* sleep for a long time if there is nothing to do. */ |
1719 | if (list_empty(&target->bt_delwrite_queue)) | |
1720 | tout = MAX_SCHEDULE_TIMEOUT; | |
1721 | schedule_timeout_interruptible(tout); | |
1da177e4 | 1722 | |
c9c12971 | 1723 | xfs_buf_delwri_split(target, &tmp, age); |
089716aa | 1724 | list_sort(NULL, &tmp, xfs_buf_cmp); |
a1b7ea5d CH |
1725 | |
1726 | blk_start_plug(&plug); | |
1da177e4 | 1727 | while (!list_empty(&tmp)) { |
089716aa DC |
1728 | struct xfs_buf *bp; |
1729 | bp = list_first_entry(&tmp, struct xfs_buf, b_list); | |
ce8e922c | 1730 | list_del_init(&bp->b_list); |
939d723b | 1731 | xfs_bdstrat_cb(bp); |
1da177e4 | 1732 | } |
a1b7ea5d | 1733 | blk_finish_plug(&plug); |
4df08c52 | 1734 | } while (!kthread_should_stop()); |
1da177e4 | 1735 | |
4df08c52 | 1736 | return 0; |
1da177e4 LT |
1737 | } |
1738 | ||
1739 | /* | |
ce8e922c NS |
1740 | * Go through all incore buffers, and release buffers if they belong to |
1741 | * the given device. This is used in filesystem error handling to | |
1742 | * preserve the consistency of its metadata. | |
1da177e4 LT |
1743 | */ |
1744 | int | |
1745 | xfs_flush_buftarg( | |
585e6d88 DC |
1746 | xfs_buftarg_t *target, |
1747 | int wait) | |
1da177e4 | 1748 | { |
089716aa | 1749 | xfs_buf_t *bp; |
585e6d88 | 1750 | int pincount = 0; |
089716aa DC |
1751 | LIST_HEAD(tmp_list); |
1752 | LIST_HEAD(wait_list); | |
a1b7ea5d | 1753 | struct blk_plug plug; |
1da177e4 | 1754 | |
c626d174 | 1755 | xfs_buf_runall_queues(xfsconvertd_workqueue); |
ce8e922c NS |
1756 | xfs_buf_runall_queues(xfsdatad_workqueue); |
1757 | xfs_buf_runall_queues(xfslogd_workqueue); | |
1da177e4 | 1758 | |
5e6a07df | 1759 | set_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
089716aa | 1760 | pincount = xfs_buf_delwri_split(target, &tmp_list, 0); |
1da177e4 LT |
1761 | |
1762 | /* | |
089716aa DC |
1763 | * Dropped the delayed write list lock, now walk the temporary list. |
1764 | * All I/O is issued async and then if we need to wait for completion | |
1765 | * we do that after issuing all the IO. | |
1da177e4 | 1766 | */ |
089716aa | 1767 | list_sort(NULL, &tmp_list, xfs_buf_cmp); |
a1b7ea5d CH |
1768 | |
1769 | blk_start_plug(&plug); | |
089716aa DC |
1770 | while (!list_empty(&tmp_list)) { |
1771 | bp = list_first_entry(&tmp_list, struct xfs_buf, b_list); | |
585e6d88 | 1772 | ASSERT(target == bp->b_target); |
089716aa DC |
1773 | list_del_init(&bp->b_list); |
1774 | if (wait) { | |
ce8e922c | 1775 | bp->b_flags &= ~XBF_ASYNC; |
089716aa DC |
1776 | list_add(&bp->b_list, &wait_list); |
1777 | } | |
939d723b | 1778 | xfs_bdstrat_cb(bp); |
1da177e4 | 1779 | } |
a1b7ea5d | 1780 | blk_finish_plug(&plug); |
1da177e4 | 1781 | |
089716aa | 1782 | if (wait) { |
a1b7ea5d | 1783 | /* Wait for IO to complete. */ |
089716aa DC |
1784 | while (!list_empty(&wait_list)) { |
1785 | bp = list_first_entry(&wait_list, struct xfs_buf, b_list); | |
f07c2250 | 1786 | |
089716aa | 1787 | list_del_init(&bp->b_list); |
1a1a3e97 | 1788 | xfs_buf_iowait(bp); |
089716aa DC |
1789 | xfs_buf_relse(bp); |
1790 | } | |
1da177e4 LT |
1791 | } |
1792 | ||
1da177e4 LT |
1793 | return pincount; |
1794 | } | |
1795 | ||
04d8b284 | 1796 | int __init |
ce8e922c | 1797 | xfs_buf_init(void) |
1da177e4 | 1798 | { |
8758280f NS |
1799 | xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf", |
1800 | KM_ZONE_HWALIGN, NULL); | |
ce8e922c | 1801 | if (!xfs_buf_zone) |
0b1b213f | 1802 | goto out; |
04d8b284 | 1803 | |
51749e47 | 1804 | xfslogd_workqueue = alloc_workqueue("xfslogd", |
6370a6ad | 1805 | WQ_MEM_RECLAIM | WQ_HIGHPRI, 1); |
23ea4032 | 1806 | if (!xfslogd_workqueue) |
04d8b284 | 1807 | goto out_free_buf_zone; |
1da177e4 | 1808 | |
83e75904 | 1809 | xfsdatad_workqueue = alloc_workqueue("xfsdatad", WQ_MEM_RECLAIM, 1); |
23ea4032 CH |
1810 | if (!xfsdatad_workqueue) |
1811 | goto out_destroy_xfslogd_workqueue; | |
1da177e4 | 1812 | |
83e75904 TH |
1813 | xfsconvertd_workqueue = alloc_workqueue("xfsconvertd", |
1814 | WQ_MEM_RECLAIM, 1); | |
c626d174 DC |
1815 | if (!xfsconvertd_workqueue) |
1816 | goto out_destroy_xfsdatad_workqueue; | |
1817 | ||
23ea4032 | 1818 | return 0; |
1da177e4 | 1819 | |
c626d174 DC |
1820 | out_destroy_xfsdatad_workqueue: |
1821 | destroy_workqueue(xfsdatad_workqueue); | |
23ea4032 CH |
1822 | out_destroy_xfslogd_workqueue: |
1823 | destroy_workqueue(xfslogd_workqueue); | |
23ea4032 | 1824 | out_free_buf_zone: |
ce8e922c | 1825 | kmem_zone_destroy(xfs_buf_zone); |
0b1b213f | 1826 | out: |
8758280f | 1827 | return -ENOMEM; |
1da177e4 LT |
1828 | } |
1829 | ||
1da177e4 | 1830 | void |
ce8e922c | 1831 | xfs_buf_terminate(void) |
1da177e4 | 1832 | { |
c626d174 | 1833 | destroy_workqueue(xfsconvertd_workqueue); |
04d8b284 CH |
1834 | destroy_workqueue(xfsdatad_workqueue); |
1835 | destroy_workqueue(xfslogd_workqueue); | |
ce8e922c | 1836 | kmem_zone_destroy(xfs_buf_zone); |
1da177e4 | 1837 | } |
e6a0e9cd TS |
1838 | |
1839 | #ifdef CONFIG_KDB_MODULES | |
1840 | struct list_head * | |
1841 | xfs_get_buftarg_list(void) | |
1842 | { | |
1843 | return &xfs_buftarg_list; | |
1844 | } | |
1845 | #endif |