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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> | |
21 | #include <linux/slab.h> | |
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" | |
39 | #include "xfs_ag.h" | |
40 | #include "xfs_dmapi.h" | |
41 | #include "xfs_mount.h" | |
42 | ||
7989cb8e | 43 | static kmem_zone_t *xfs_buf_zone; |
a6867a68 | 44 | STATIC int xfsbufd(void *); |
27496a8c | 45 | STATIC int xfsbufd_wakeup(int, gfp_t); |
ce8e922c | 46 | STATIC void xfs_buf_delwri_queue(xfs_buf_t *, int); |
8e1f936b RR |
47 | static struct shrinker xfs_buf_shake = { |
48 | .shrink = xfsbufd_wakeup, | |
49 | .seeks = DEFAULT_SEEKS, | |
50 | }; | |
23ea4032 | 51 | |
7989cb8e | 52 | static struct workqueue_struct *xfslogd_workqueue; |
0829c360 | 53 | struct workqueue_struct *xfsdatad_workqueue; |
c626d174 | 54 | struct workqueue_struct *xfsconvertd_workqueue; |
1da177e4 | 55 | |
ce8e922c | 56 | #ifdef XFS_BUF_TRACE |
1da177e4 | 57 | void |
ce8e922c NS |
58 | xfs_buf_trace( |
59 | xfs_buf_t *bp, | |
1da177e4 LT |
60 | char *id, |
61 | void *data, | |
62 | void *ra) | |
63 | { | |
ce8e922c NS |
64 | ktrace_enter(xfs_buf_trace_buf, |
65 | bp, id, | |
66 | (void *)(unsigned long)bp->b_flags, | |
67 | (void *)(unsigned long)bp->b_hold.counter, | |
d63f154a | 68 | (void *)(unsigned long)bp->b_sema.count, |
1da177e4 LT |
69 | (void *)current, |
70 | data, ra, | |
ce8e922c NS |
71 | (void *)(unsigned long)((bp->b_file_offset>>32) & 0xffffffff), |
72 | (void *)(unsigned long)(bp->b_file_offset & 0xffffffff), | |
73 | (void *)(unsigned long)bp->b_buffer_length, | |
1da177e4 LT |
74 | NULL, NULL, NULL, NULL, NULL); |
75 | } | |
ce8e922c NS |
76 | ktrace_t *xfs_buf_trace_buf; |
77 | #define XFS_BUF_TRACE_SIZE 4096 | |
78 | #define XB_TRACE(bp, id, data) \ | |
79 | xfs_buf_trace(bp, id, (void *)data, (void *)__builtin_return_address(0)) | |
1da177e4 | 80 | #else |
ce8e922c | 81 | #define XB_TRACE(bp, id, data) do { } while (0) |
1da177e4 LT |
82 | #endif |
83 | ||
ce8e922c NS |
84 | #ifdef XFS_BUF_LOCK_TRACKING |
85 | # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid) | |
86 | # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1) | |
87 | # define XB_GET_OWNER(bp) ((bp)->b_last_holder) | |
1da177e4 | 88 | #else |
ce8e922c NS |
89 | # define XB_SET_OWNER(bp) do { } while (0) |
90 | # define XB_CLEAR_OWNER(bp) do { } while (0) | |
91 | # define XB_GET_OWNER(bp) do { } while (0) | |
1da177e4 LT |
92 | #endif |
93 | ||
ce8e922c NS |
94 | #define xb_to_gfp(flags) \ |
95 | ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : \ | |
96 | ((flags) & XBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN) | |
1da177e4 | 97 | |
ce8e922c NS |
98 | #define xb_to_km(flags) \ |
99 | (((flags) & XBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP) | |
1da177e4 | 100 | |
ce8e922c NS |
101 | #define xfs_buf_allocate(flags) \ |
102 | kmem_zone_alloc(xfs_buf_zone, xb_to_km(flags)) | |
103 | #define xfs_buf_deallocate(bp) \ | |
104 | kmem_zone_free(xfs_buf_zone, (bp)); | |
1da177e4 LT |
105 | |
106 | /* | |
ce8e922c | 107 | * Page Region interfaces. |
1da177e4 | 108 | * |
ce8e922c NS |
109 | * For pages in filesystems where the blocksize is smaller than the |
110 | * pagesize, we use the page->private field (long) to hold a bitmap | |
111 | * of uptodate regions within the page. | |
1da177e4 | 112 | * |
ce8e922c | 113 | * Each such region is "bytes per page / bits per long" bytes long. |
1da177e4 | 114 | * |
ce8e922c NS |
115 | * NBPPR == number-of-bytes-per-page-region |
116 | * BTOPR == bytes-to-page-region (rounded up) | |
117 | * BTOPRT == bytes-to-page-region-truncated (rounded down) | |
1da177e4 LT |
118 | */ |
119 | #if (BITS_PER_LONG == 32) | |
120 | #define PRSHIFT (PAGE_CACHE_SHIFT - 5) /* (32 == 1<<5) */ | |
121 | #elif (BITS_PER_LONG == 64) | |
122 | #define PRSHIFT (PAGE_CACHE_SHIFT - 6) /* (64 == 1<<6) */ | |
123 | #else | |
124 | #error BITS_PER_LONG must be 32 or 64 | |
125 | #endif | |
126 | #define NBPPR (PAGE_CACHE_SIZE/BITS_PER_LONG) | |
127 | #define BTOPR(b) (((unsigned int)(b) + (NBPPR - 1)) >> PRSHIFT) | |
128 | #define BTOPRT(b) (((unsigned int)(b) >> PRSHIFT)) | |
129 | ||
130 | STATIC unsigned long | |
131 | page_region_mask( | |
132 | size_t offset, | |
133 | size_t length) | |
134 | { | |
135 | unsigned long mask; | |
136 | int first, final; | |
137 | ||
138 | first = BTOPR(offset); | |
139 | final = BTOPRT(offset + length - 1); | |
140 | first = min(first, final); | |
141 | ||
142 | mask = ~0UL; | |
143 | mask <<= BITS_PER_LONG - (final - first); | |
144 | mask >>= BITS_PER_LONG - (final); | |
145 | ||
146 | ASSERT(offset + length <= PAGE_CACHE_SIZE); | |
147 | ASSERT((final - first) < BITS_PER_LONG && (final - first) >= 0); | |
148 | ||
149 | return mask; | |
150 | } | |
151 | ||
7989cb8e | 152 | STATIC_INLINE void |
1da177e4 LT |
153 | set_page_region( |
154 | struct page *page, | |
155 | size_t offset, | |
156 | size_t length) | |
157 | { | |
4c21e2f2 HD |
158 | set_page_private(page, |
159 | page_private(page) | page_region_mask(offset, length)); | |
160 | if (page_private(page) == ~0UL) | |
1da177e4 LT |
161 | SetPageUptodate(page); |
162 | } | |
163 | ||
7989cb8e | 164 | STATIC_INLINE int |
1da177e4 LT |
165 | test_page_region( |
166 | struct page *page, | |
167 | size_t offset, | |
168 | size_t length) | |
169 | { | |
170 | unsigned long mask = page_region_mask(offset, length); | |
171 | ||
4c21e2f2 | 172 | return (mask && (page_private(page) & mask) == mask); |
1da177e4 LT |
173 | } |
174 | ||
3a011a17 FB |
175 | /* |
176 | * Mapping of multi-page buffers into contiguous virtual space | |
177 | */ | |
178 | ||
179 | typedef struct a_list { | |
180 | void *vm_addr; | |
181 | struct a_list *next; | |
182 | } a_list_t; | |
183 | ||
184 | static a_list_t *as_free_head; | |
185 | static int as_list_len; | |
186 | static DEFINE_SPINLOCK(as_lock); | |
187 | ||
188 | /* | |
189 | * Try to batch vunmaps because they are costly. | |
190 | */ | |
191 | STATIC void | |
192 | free_address( | |
193 | void *addr) | |
194 | { | |
195 | a_list_t *aentry; | |
196 | ||
197 | #ifdef CONFIG_XEN | |
198 | /* | |
199 | * Xen needs to be able to make sure it can get an exclusive | |
200 | * RO mapping of pages it wants to turn into a pagetable. If | |
201 | * a newly allocated page is also still being vmap()ed by xfs, | |
202 | * it will cause pagetable construction to fail. This is a | |
203 | * quick workaround to always eagerly unmap pages so that Xen | |
204 | * is happy. | |
205 | */ | |
206 | vunmap(addr); | |
207 | return; | |
208 | #endif | |
209 | ||
210 | aentry = kmalloc(sizeof(a_list_t), GFP_NOWAIT); | |
211 | if (likely(aentry)) { | |
212 | spin_lock(&as_lock); | |
213 | aentry->next = as_free_head; | |
214 | aentry->vm_addr = addr; | |
215 | as_free_head = aentry; | |
216 | as_list_len++; | |
217 | spin_unlock(&as_lock); | |
218 | } else { | |
219 | vunmap(addr); | |
220 | } | |
221 | } | |
222 | ||
223 | STATIC void | |
224 | purge_addresses(void) | |
225 | { | |
226 | a_list_t *aentry, *old; | |
227 | ||
228 | if (as_free_head == NULL) | |
229 | return; | |
230 | ||
231 | spin_lock(&as_lock); | |
232 | aentry = as_free_head; | |
233 | as_free_head = NULL; | |
234 | as_list_len = 0; | |
235 | spin_unlock(&as_lock); | |
236 | ||
237 | while ((old = aentry) != NULL) { | |
238 | vunmap(aentry->vm_addr); | |
239 | aentry = aentry->next; | |
240 | kfree(old); | |
241 | } | |
242 | } | |
243 | ||
1da177e4 | 244 | /* |
ce8e922c | 245 | * Internal xfs_buf_t object manipulation |
1da177e4 LT |
246 | */ |
247 | ||
248 | STATIC void | |
ce8e922c NS |
249 | _xfs_buf_initialize( |
250 | xfs_buf_t *bp, | |
1da177e4 | 251 | xfs_buftarg_t *target, |
204ab25f | 252 | xfs_off_t range_base, |
1da177e4 | 253 | size_t range_length, |
ce8e922c | 254 | xfs_buf_flags_t flags) |
1da177e4 LT |
255 | { |
256 | /* | |
ce8e922c | 257 | * We don't want certain flags to appear in b_flags. |
1da177e4 | 258 | */ |
ce8e922c NS |
259 | flags &= ~(XBF_LOCK|XBF_MAPPED|XBF_DONT_BLOCK|XBF_READ_AHEAD); |
260 | ||
261 | memset(bp, 0, sizeof(xfs_buf_t)); | |
262 | atomic_set(&bp->b_hold, 1); | |
b4dd330b | 263 | init_completion(&bp->b_iowait); |
ce8e922c NS |
264 | INIT_LIST_HEAD(&bp->b_list); |
265 | INIT_LIST_HEAD(&bp->b_hash_list); | |
266 | init_MUTEX_LOCKED(&bp->b_sema); /* held, no waiters */ | |
267 | XB_SET_OWNER(bp); | |
268 | bp->b_target = target; | |
269 | bp->b_file_offset = range_base; | |
1da177e4 LT |
270 | /* |
271 | * Set buffer_length and count_desired to the same value initially. | |
272 | * I/O routines should use count_desired, which will be the same in | |
273 | * most cases but may be reset (e.g. XFS recovery). | |
274 | */ | |
ce8e922c NS |
275 | bp->b_buffer_length = bp->b_count_desired = range_length; |
276 | bp->b_flags = flags; | |
277 | bp->b_bn = XFS_BUF_DADDR_NULL; | |
278 | atomic_set(&bp->b_pin_count, 0); | |
279 | init_waitqueue_head(&bp->b_waiters); | |
280 | ||
281 | XFS_STATS_INC(xb_create); | |
282 | XB_TRACE(bp, "initialize", target); | |
1da177e4 LT |
283 | } |
284 | ||
285 | /* | |
ce8e922c NS |
286 | * Allocate a page array capable of holding a specified number |
287 | * of pages, and point the page buf at it. | |
1da177e4 LT |
288 | */ |
289 | STATIC int | |
ce8e922c NS |
290 | _xfs_buf_get_pages( |
291 | xfs_buf_t *bp, | |
1da177e4 | 292 | int page_count, |
ce8e922c | 293 | xfs_buf_flags_t flags) |
1da177e4 LT |
294 | { |
295 | /* Make sure that we have a page list */ | |
ce8e922c NS |
296 | if (bp->b_pages == NULL) { |
297 | bp->b_offset = xfs_buf_poff(bp->b_file_offset); | |
298 | bp->b_page_count = page_count; | |
299 | if (page_count <= XB_PAGES) { | |
300 | bp->b_pages = bp->b_page_array; | |
1da177e4 | 301 | } else { |
ce8e922c NS |
302 | bp->b_pages = kmem_alloc(sizeof(struct page *) * |
303 | page_count, xb_to_km(flags)); | |
304 | if (bp->b_pages == NULL) | |
1da177e4 LT |
305 | return -ENOMEM; |
306 | } | |
ce8e922c | 307 | memset(bp->b_pages, 0, sizeof(struct page *) * page_count); |
1da177e4 LT |
308 | } |
309 | return 0; | |
310 | } | |
311 | ||
312 | /* | |
ce8e922c | 313 | * Frees b_pages if it was allocated. |
1da177e4 LT |
314 | */ |
315 | STATIC void | |
ce8e922c | 316 | _xfs_buf_free_pages( |
1da177e4 LT |
317 | xfs_buf_t *bp) |
318 | { | |
ce8e922c | 319 | if (bp->b_pages != bp->b_page_array) { |
f0e2d93c | 320 | kmem_free(bp->b_pages); |
1da177e4 LT |
321 | } |
322 | } | |
323 | ||
324 | /* | |
325 | * Releases the specified buffer. | |
326 | * | |
327 | * The modification state of any associated pages is left unchanged. | |
ce8e922c | 328 | * The buffer most not be on any hash - use xfs_buf_rele instead for |
1da177e4 LT |
329 | * hashed and refcounted buffers |
330 | */ | |
331 | void | |
ce8e922c | 332 | xfs_buf_free( |
1da177e4 LT |
333 | xfs_buf_t *bp) |
334 | { | |
ce8e922c | 335 | XB_TRACE(bp, "free", 0); |
1da177e4 | 336 | |
ce8e922c | 337 | ASSERT(list_empty(&bp->b_hash_list)); |
1da177e4 | 338 | |
1fa40b01 | 339 | if (bp->b_flags & (_XBF_PAGE_CACHE|_XBF_PAGES)) { |
1da177e4 LT |
340 | uint i; |
341 | ||
ce8e922c | 342 | if ((bp->b_flags & XBF_MAPPED) && (bp->b_page_count > 1)) |
3a011a17 | 343 | free_address(bp->b_addr - bp->b_offset); |
1da177e4 | 344 | |
948ecdb4 NS |
345 | for (i = 0; i < bp->b_page_count; i++) { |
346 | struct page *page = bp->b_pages[i]; | |
347 | ||
1fa40b01 CH |
348 | if (bp->b_flags & _XBF_PAGE_CACHE) |
349 | ASSERT(!PagePrivate(page)); | |
948ecdb4 NS |
350 | page_cache_release(page); |
351 | } | |
ce8e922c | 352 | _xfs_buf_free_pages(bp); |
1da177e4 LT |
353 | } |
354 | ||
ce8e922c | 355 | xfs_buf_deallocate(bp); |
1da177e4 LT |
356 | } |
357 | ||
358 | /* | |
359 | * Finds all pages for buffer in question and builds it's page list. | |
360 | */ | |
361 | STATIC int | |
ce8e922c | 362 | _xfs_buf_lookup_pages( |
1da177e4 LT |
363 | xfs_buf_t *bp, |
364 | uint flags) | |
365 | { | |
ce8e922c NS |
366 | struct address_space *mapping = bp->b_target->bt_mapping; |
367 | size_t blocksize = bp->b_target->bt_bsize; | |
368 | size_t size = bp->b_count_desired; | |
1da177e4 | 369 | size_t nbytes, offset; |
ce8e922c | 370 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 LT |
371 | unsigned short page_count, i; |
372 | pgoff_t first; | |
204ab25f | 373 | xfs_off_t end; |
1da177e4 LT |
374 | int error; |
375 | ||
ce8e922c NS |
376 | end = bp->b_file_offset + bp->b_buffer_length; |
377 | page_count = xfs_buf_btoc(end) - xfs_buf_btoct(bp->b_file_offset); | |
1da177e4 | 378 | |
ce8e922c | 379 | error = _xfs_buf_get_pages(bp, page_count, flags); |
1da177e4 LT |
380 | if (unlikely(error)) |
381 | return error; | |
ce8e922c | 382 | bp->b_flags |= _XBF_PAGE_CACHE; |
1da177e4 | 383 | |
ce8e922c NS |
384 | offset = bp->b_offset; |
385 | first = bp->b_file_offset >> PAGE_CACHE_SHIFT; | |
1da177e4 | 386 | |
ce8e922c | 387 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
388 | struct page *page; |
389 | uint retries = 0; | |
390 | ||
391 | retry: | |
392 | page = find_or_create_page(mapping, first + i, gfp_mask); | |
393 | if (unlikely(page == NULL)) { | |
ce8e922c NS |
394 | if (flags & XBF_READ_AHEAD) { |
395 | bp->b_page_count = i; | |
6ab455ee CH |
396 | for (i = 0; i < bp->b_page_count; i++) |
397 | unlock_page(bp->b_pages[i]); | |
1da177e4 LT |
398 | return -ENOMEM; |
399 | } | |
400 | ||
401 | /* | |
402 | * This could deadlock. | |
403 | * | |
404 | * But until all the XFS lowlevel code is revamped to | |
405 | * handle buffer allocation failures we can't do much. | |
406 | */ | |
407 | if (!(++retries % 100)) | |
408 | printk(KERN_ERR | |
409 | "XFS: possible memory allocation " | |
410 | "deadlock in %s (mode:0x%x)\n", | |
34a622b2 | 411 | __func__, gfp_mask); |
1da177e4 | 412 | |
ce8e922c | 413 | XFS_STATS_INC(xb_page_retries); |
23ea4032 | 414 | xfsbufd_wakeup(0, gfp_mask); |
8aa7e847 | 415 | congestion_wait(BLK_RW_ASYNC, HZ/50); |
1da177e4 LT |
416 | goto retry; |
417 | } | |
418 | ||
ce8e922c | 419 | XFS_STATS_INC(xb_page_found); |
1da177e4 LT |
420 | |
421 | nbytes = min_t(size_t, size, PAGE_CACHE_SIZE - offset); | |
422 | size -= nbytes; | |
423 | ||
948ecdb4 | 424 | ASSERT(!PagePrivate(page)); |
1da177e4 LT |
425 | if (!PageUptodate(page)) { |
426 | page_count--; | |
6ab455ee CH |
427 | if (blocksize >= PAGE_CACHE_SIZE) { |
428 | if (flags & XBF_READ) | |
429 | bp->b_flags |= _XBF_PAGE_LOCKED; | |
430 | } else if (!PagePrivate(page)) { | |
1da177e4 LT |
431 | if (test_page_region(page, offset, nbytes)) |
432 | page_count++; | |
433 | } | |
434 | } | |
435 | ||
ce8e922c | 436 | bp->b_pages[i] = page; |
1da177e4 LT |
437 | offset = 0; |
438 | } | |
439 | ||
6ab455ee CH |
440 | if (!(bp->b_flags & _XBF_PAGE_LOCKED)) { |
441 | for (i = 0; i < bp->b_page_count; i++) | |
442 | unlock_page(bp->b_pages[i]); | |
443 | } | |
444 | ||
ce8e922c NS |
445 | if (page_count == bp->b_page_count) |
446 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 447 | |
ce8e922c | 448 | XB_TRACE(bp, "lookup_pages", (long)page_count); |
1da177e4 LT |
449 | return error; |
450 | } | |
451 | ||
452 | /* | |
453 | * Map buffer into kernel address-space if nessecary. | |
454 | */ | |
455 | STATIC int | |
ce8e922c | 456 | _xfs_buf_map_pages( |
1da177e4 LT |
457 | xfs_buf_t *bp, |
458 | uint flags) | |
459 | { | |
460 | /* A single page buffer is always mappable */ | |
ce8e922c NS |
461 | if (bp->b_page_count == 1) { |
462 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; | |
463 | bp->b_flags |= XBF_MAPPED; | |
464 | } else if (flags & XBF_MAPPED) { | |
3a011a17 FB |
465 | if (as_list_len > 64) |
466 | purge_addresses(); | |
cf7dab80 FB |
467 | bp->b_addr = vmap(bp->b_pages, bp->b_page_count, |
468 | VM_MAP, PAGE_KERNEL); | |
ce8e922c | 469 | if (unlikely(bp->b_addr == NULL)) |
1da177e4 | 470 | return -ENOMEM; |
ce8e922c NS |
471 | bp->b_addr += bp->b_offset; |
472 | bp->b_flags |= XBF_MAPPED; | |
1da177e4 LT |
473 | } |
474 | ||
475 | return 0; | |
476 | } | |
477 | ||
478 | /* | |
479 | * Finding and Reading Buffers | |
480 | */ | |
481 | ||
482 | /* | |
ce8e922c | 483 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 LT |
484 | * a given range of an inode. The buffer is returned |
485 | * locked. If other overlapping buffers exist, they are | |
486 | * released before the new buffer is created and locked, | |
487 | * which may imply that this call will block until those buffers | |
488 | * are unlocked. No I/O is implied by this call. | |
489 | */ | |
490 | xfs_buf_t * | |
ce8e922c | 491 | _xfs_buf_find( |
1da177e4 | 492 | xfs_buftarg_t *btp, /* block device target */ |
204ab25f | 493 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 494 | size_t isize, /* length of range */ |
ce8e922c NS |
495 | xfs_buf_flags_t flags, |
496 | xfs_buf_t *new_bp) | |
1da177e4 | 497 | { |
204ab25f | 498 | xfs_off_t range_base; |
1da177e4 LT |
499 | size_t range_length; |
500 | xfs_bufhash_t *hash; | |
ce8e922c | 501 | xfs_buf_t *bp, *n; |
1da177e4 LT |
502 | |
503 | range_base = (ioff << BBSHIFT); | |
504 | range_length = (isize << BBSHIFT); | |
505 | ||
506 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
ce8e922c | 507 | ASSERT(!(range_length < (1 << btp->bt_sshift))); |
204ab25f | 508 | ASSERT(!(range_base & (xfs_off_t)btp->bt_smask)); |
1da177e4 LT |
509 | |
510 | hash = &btp->bt_hash[hash_long((unsigned long)ioff, btp->bt_hashshift)]; | |
511 | ||
512 | spin_lock(&hash->bh_lock); | |
513 | ||
ce8e922c NS |
514 | list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) { |
515 | ASSERT(btp == bp->b_target); | |
516 | if (bp->b_file_offset == range_base && | |
517 | bp->b_buffer_length == range_length) { | |
1da177e4 | 518 | /* |
ce8e922c | 519 | * If we look at something, bring it to the |
1da177e4 LT |
520 | * front of the list for next time. |
521 | */ | |
ce8e922c NS |
522 | atomic_inc(&bp->b_hold); |
523 | list_move(&bp->b_hash_list, &hash->bh_list); | |
1da177e4 LT |
524 | goto found; |
525 | } | |
526 | } | |
527 | ||
528 | /* No match found */ | |
ce8e922c NS |
529 | if (new_bp) { |
530 | _xfs_buf_initialize(new_bp, btp, range_base, | |
1da177e4 | 531 | range_length, flags); |
ce8e922c NS |
532 | new_bp->b_hash = hash; |
533 | list_add(&new_bp->b_hash_list, &hash->bh_list); | |
1da177e4 | 534 | } else { |
ce8e922c | 535 | XFS_STATS_INC(xb_miss_locked); |
1da177e4 LT |
536 | } |
537 | ||
538 | spin_unlock(&hash->bh_lock); | |
ce8e922c | 539 | return new_bp; |
1da177e4 LT |
540 | |
541 | found: | |
542 | spin_unlock(&hash->bh_lock); | |
543 | ||
544 | /* Attempt to get the semaphore without sleeping, | |
545 | * if this does not work then we need to drop the | |
546 | * spinlock and do a hard attempt on the semaphore. | |
547 | */ | |
ce8e922c NS |
548 | if (down_trylock(&bp->b_sema)) { |
549 | if (!(flags & XBF_TRYLOCK)) { | |
1da177e4 | 550 | /* wait for buffer ownership */ |
ce8e922c NS |
551 | XB_TRACE(bp, "get_lock", 0); |
552 | xfs_buf_lock(bp); | |
553 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 LT |
554 | } else { |
555 | /* We asked for a trylock and failed, no need | |
556 | * to look at file offset and length here, we | |
ce8e922c NS |
557 | * know that this buffer at least overlaps our |
558 | * buffer and is locked, therefore our buffer | |
559 | * either does not exist, or is this buffer. | |
1da177e4 | 560 | */ |
ce8e922c NS |
561 | xfs_buf_rele(bp); |
562 | XFS_STATS_INC(xb_busy_locked); | |
563 | return NULL; | |
1da177e4 LT |
564 | } |
565 | } else { | |
566 | /* trylock worked */ | |
ce8e922c | 567 | XB_SET_OWNER(bp); |
1da177e4 LT |
568 | } |
569 | ||
ce8e922c NS |
570 | if (bp->b_flags & XBF_STALE) { |
571 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
572 | bp->b_flags &= XBF_MAPPED; | |
2f926587 | 573 | } |
ce8e922c NS |
574 | XB_TRACE(bp, "got_lock", 0); |
575 | XFS_STATS_INC(xb_get_locked); | |
576 | return bp; | |
1da177e4 LT |
577 | } |
578 | ||
579 | /* | |
ce8e922c | 580 | * Assembles a buffer covering the specified range. |
1da177e4 LT |
581 | * Storage in memory for all portions of the buffer will be allocated, |
582 | * although backing storage may not be. | |
583 | */ | |
584 | xfs_buf_t * | |
ce8e922c | 585 | xfs_buf_get_flags( |
1da177e4 | 586 | xfs_buftarg_t *target,/* target for buffer */ |
204ab25f | 587 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 588 | size_t isize, /* length of range */ |
ce8e922c | 589 | xfs_buf_flags_t flags) |
1da177e4 | 590 | { |
ce8e922c | 591 | xfs_buf_t *bp, *new_bp; |
1da177e4 LT |
592 | int error = 0, i; |
593 | ||
ce8e922c NS |
594 | new_bp = xfs_buf_allocate(flags); |
595 | if (unlikely(!new_bp)) | |
1da177e4 LT |
596 | return NULL; |
597 | ||
ce8e922c NS |
598 | bp = _xfs_buf_find(target, ioff, isize, flags, new_bp); |
599 | if (bp == new_bp) { | |
600 | error = _xfs_buf_lookup_pages(bp, flags); | |
1da177e4 LT |
601 | if (error) |
602 | goto no_buffer; | |
603 | } else { | |
ce8e922c NS |
604 | xfs_buf_deallocate(new_bp); |
605 | if (unlikely(bp == NULL)) | |
1da177e4 LT |
606 | return NULL; |
607 | } | |
608 | ||
ce8e922c NS |
609 | for (i = 0; i < bp->b_page_count; i++) |
610 | mark_page_accessed(bp->b_pages[i]); | |
1da177e4 | 611 | |
ce8e922c NS |
612 | if (!(bp->b_flags & XBF_MAPPED)) { |
613 | error = _xfs_buf_map_pages(bp, flags); | |
1da177e4 LT |
614 | if (unlikely(error)) { |
615 | printk(KERN_WARNING "%s: failed to map pages\n", | |
34a622b2 | 616 | __func__); |
1da177e4 LT |
617 | goto no_buffer; |
618 | } | |
619 | } | |
620 | ||
ce8e922c | 621 | XFS_STATS_INC(xb_get); |
1da177e4 LT |
622 | |
623 | /* | |
624 | * Always fill in the block number now, the mapped cases can do | |
625 | * their own overlay of this later. | |
626 | */ | |
ce8e922c NS |
627 | bp->b_bn = ioff; |
628 | bp->b_count_desired = bp->b_buffer_length; | |
1da177e4 | 629 | |
ce8e922c NS |
630 | XB_TRACE(bp, "get", (unsigned long)flags); |
631 | return bp; | |
1da177e4 LT |
632 | |
633 | no_buffer: | |
ce8e922c NS |
634 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
635 | xfs_buf_unlock(bp); | |
636 | xfs_buf_rele(bp); | |
1da177e4 LT |
637 | return NULL; |
638 | } | |
639 | ||
5d765b97 CH |
640 | STATIC int |
641 | _xfs_buf_read( | |
642 | xfs_buf_t *bp, | |
643 | xfs_buf_flags_t flags) | |
644 | { | |
645 | int status; | |
646 | ||
647 | XB_TRACE(bp, "_xfs_buf_read", (unsigned long)flags); | |
648 | ||
649 | ASSERT(!(flags & (XBF_DELWRI|XBF_WRITE))); | |
650 | ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL); | |
651 | ||
652 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_DELWRI | \ | |
653 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
654 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | \ | |
655 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
656 | ||
657 | status = xfs_buf_iorequest(bp); | |
658 | if (!status && !(flags & XBF_ASYNC)) | |
659 | status = xfs_buf_iowait(bp); | |
660 | return status; | |
661 | } | |
662 | ||
1da177e4 LT |
663 | xfs_buf_t * |
664 | xfs_buf_read_flags( | |
665 | xfs_buftarg_t *target, | |
204ab25f | 666 | xfs_off_t ioff, |
1da177e4 | 667 | size_t isize, |
ce8e922c | 668 | xfs_buf_flags_t flags) |
1da177e4 | 669 | { |
ce8e922c NS |
670 | xfs_buf_t *bp; |
671 | ||
672 | flags |= XBF_READ; | |
673 | ||
674 | bp = xfs_buf_get_flags(target, ioff, isize, flags); | |
675 | if (bp) { | |
676 | if (!XFS_BUF_ISDONE(bp)) { | |
677 | XB_TRACE(bp, "read", (unsigned long)flags); | |
678 | XFS_STATS_INC(xb_get_read); | |
5d765b97 | 679 | _xfs_buf_read(bp, flags); |
ce8e922c NS |
680 | } else if (flags & XBF_ASYNC) { |
681 | XB_TRACE(bp, "read_async", (unsigned long)flags); | |
1da177e4 LT |
682 | /* |
683 | * Read ahead call which is already satisfied, | |
684 | * drop the buffer | |
685 | */ | |
686 | goto no_buffer; | |
687 | } else { | |
ce8e922c | 688 | XB_TRACE(bp, "read_done", (unsigned long)flags); |
1da177e4 | 689 | /* We do not want read in the flags */ |
ce8e922c | 690 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
691 | } |
692 | } | |
693 | ||
ce8e922c | 694 | return bp; |
1da177e4 LT |
695 | |
696 | no_buffer: | |
ce8e922c NS |
697 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
698 | xfs_buf_unlock(bp); | |
699 | xfs_buf_rele(bp); | |
1da177e4 LT |
700 | return NULL; |
701 | } | |
702 | ||
1da177e4 | 703 | /* |
ce8e922c NS |
704 | * If we are not low on memory then do the readahead in a deadlock |
705 | * safe manner. | |
1da177e4 LT |
706 | */ |
707 | void | |
ce8e922c | 708 | xfs_buf_readahead( |
1da177e4 | 709 | xfs_buftarg_t *target, |
204ab25f | 710 | xfs_off_t ioff, |
1da177e4 | 711 | size_t isize, |
ce8e922c | 712 | xfs_buf_flags_t flags) |
1da177e4 LT |
713 | { |
714 | struct backing_dev_info *bdi; | |
715 | ||
ce8e922c | 716 | bdi = target->bt_mapping->backing_dev_info; |
1da177e4 LT |
717 | if (bdi_read_congested(bdi)) |
718 | return; | |
719 | ||
ce8e922c | 720 | flags |= (XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD); |
1da177e4 LT |
721 | xfs_buf_read_flags(target, ioff, isize, flags); |
722 | } | |
723 | ||
724 | xfs_buf_t * | |
ce8e922c | 725 | xfs_buf_get_empty( |
1da177e4 LT |
726 | size_t len, |
727 | xfs_buftarg_t *target) | |
728 | { | |
ce8e922c | 729 | xfs_buf_t *bp; |
1da177e4 | 730 | |
ce8e922c NS |
731 | bp = xfs_buf_allocate(0); |
732 | if (bp) | |
733 | _xfs_buf_initialize(bp, target, 0, len, 0); | |
734 | return bp; | |
1da177e4 LT |
735 | } |
736 | ||
737 | static inline struct page * | |
738 | mem_to_page( | |
739 | void *addr) | |
740 | { | |
9e2779fa | 741 | if ((!is_vmalloc_addr(addr))) { |
1da177e4 LT |
742 | return virt_to_page(addr); |
743 | } else { | |
744 | return vmalloc_to_page(addr); | |
745 | } | |
746 | } | |
747 | ||
748 | int | |
ce8e922c NS |
749 | xfs_buf_associate_memory( |
750 | xfs_buf_t *bp, | |
1da177e4 LT |
751 | void *mem, |
752 | size_t len) | |
753 | { | |
754 | int rval; | |
755 | int i = 0; | |
d1afb678 LM |
756 | unsigned long pageaddr; |
757 | unsigned long offset; | |
758 | size_t buflen; | |
1da177e4 LT |
759 | int page_count; |
760 | ||
d1afb678 LM |
761 | pageaddr = (unsigned long)mem & PAGE_CACHE_MASK; |
762 | offset = (unsigned long)mem - pageaddr; | |
763 | buflen = PAGE_CACHE_ALIGN(len + offset); | |
764 | page_count = buflen >> PAGE_CACHE_SHIFT; | |
1da177e4 LT |
765 | |
766 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
767 | if (bp->b_pages) |
768 | _xfs_buf_free_pages(bp); | |
1da177e4 | 769 | |
ce8e922c NS |
770 | bp->b_pages = NULL; |
771 | bp->b_addr = mem; | |
1da177e4 | 772 | |
ce8e922c | 773 | rval = _xfs_buf_get_pages(bp, page_count, 0); |
1da177e4 LT |
774 | if (rval) |
775 | return rval; | |
776 | ||
ce8e922c | 777 | bp->b_offset = offset; |
d1afb678 LM |
778 | |
779 | for (i = 0; i < bp->b_page_count; i++) { | |
780 | bp->b_pages[i] = mem_to_page((void *)pageaddr); | |
781 | pageaddr += PAGE_CACHE_SIZE; | |
1da177e4 | 782 | } |
1da177e4 | 783 | |
d1afb678 LM |
784 | bp->b_count_desired = len; |
785 | bp->b_buffer_length = buflen; | |
ce8e922c | 786 | bp->b_flags |= XBF_MAPPED; |
6ab455ee | 787 | bp->b_flags &= ~_XBF_PAGE_LOCKED; |
1da177e4 LT |
788 | |
789 | return 0; | |
790 | } | |
791 | ||
792 | xfs_buf_t * | |
ce8e922c | 793 | xfs_buf_get_noaddr( |
1da177e4 LT |
794 | size_t len, |
795 | xfs_buftarg_t *target) | |
796 | { | |
1fa40b01 CH |
797 | unsigned long page_count = PAGE_ALIGN(len) >> PAGE_SHIFT; |
798 | int error, i; | |
1da177e4 | 799 | xfs_buf_t *bp; |
1da177e4 | 800 | |
ce8e922c | 801 | bp = xfs_buf_allocate(0); |
1da177e4 LT |
802 | if (unlikely(bp == NULL)) |
803 | goto fail; | |
ce8e922c | 804 | _xfs_buf_initialize(bp, target, 0, len, 0); |
1da177e4 | 805 | |
1fa40b01 CH |
806 | error = _xfs_buf_get_pages(bp, page_count, 0); |
807 | if (error) | |
1da177e4 LT |
808 | goto fail_free_buf; |
809 | ||
1fa40b01 CH |
810 | for (i = 0; i < page_count; i++) { |
811 | bp->b_pages[i] = alloc_page(GFP_KERNEL); | |
812 | if (!bp->b_pages[i]) | |
813 | goto fail_free_mem; | |
1da177e4 | 814 | } |
1fa40b01 | 815 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 816 | |
1fa40b01 CH |
817 | error = _xfs_buf_map_pages(bp, XBF_MAPPED); |
818 | if (unlikely(error)) { | |
819 | printk(KERN_WARNING "%s: failed to map pages\n", | |
34a622b2 | 820 | __func__); |
1da177e4 | 821 | goto fail_free_mem; |
1fa40b01 | 822 | } |
1da177e4 | 823 | |
ce8e922c | 824 | xfs_buf_unlock(bp); |
1da177e4 | 825 | |
1fa40b01 | 826 | XB_TRACE(bp, "no_daddr", len); |
1da177e4 | 827 | return bp; |
1fa40b01 | 828 | |
1da177e4 | 829 | fail_free_mem: |
1fa40b01 CH |
830 | while (--i >= 0) |
831 | __free_page(bp->b_pages[i]); | |
ca165b88 | 832 | _xfs_buf_free_pages(bp); |
1da177e4 | 833 | fail_free_buf: |
ca165b88 | 834 | xfs_buf_deallocate(bp); |
1da177e4 LT |
835 | fail: |
836 | return NULL; | |
837 | } | |
838 | ||
839 | /* | |
1da177e4 LT |
840 | * Increment reference count on buffer, to hold the buffer concurrently |
841 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
842 | * Must hold the buffer already to call this function. |
843 | */ | |
844 | void | |
ce8e922c NS |
845 | xfs_buf_hold( |
846 | xfs_buf_t *bp) | |
1da177e4 | 847 | { |
ce8e922c NS |
848 | atomic_inc(&bp->b_hold); |
849 | XB_TRACE(bp, "hold", 0); | |
1da177e4 LT |
850 | } |
851 | ||
852 | /* | |
ce8e922c NS |
853 | * Releases a hold on the specified buffer. If the |
854 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
855 | */ |
856 | void | |
ce8e922c NS |
857 | xfs_buf_rele( |
858 | xfs_buf_t *bp) | |
1da177e4 | 859 | { |
ce8e922c | 860 | xfs_bufhash_t *hash = bp->b_hash; |
1da177e4 | 861 | |
ce8e922c | 862 | XB_TRACE(bp, "rele", bp->b_relse); |
1da177e4 | 863 | |
fad3aa1e NS |
864 | if (unlikely(!hash)) { |
865 | ASSERT(!bp->b_relse); | |
866 | if (atomic_dec_and_test(&bp->b_hold)) | |
867 | xfs_buf_free(bp); | |
868 | return; | |
869 | } | |
870 | ||
3790689f | 871 | ASSERT(atomic_read(&bp->b_hold) > 0); |
ce8e922c NS |
872 | if (atomic_dec_and_lock(&bp->b_hold, &hash->bh_lock)) { |
873 | if (bp->b_relse) { | |
874 | atomic_inc(&bp->b_hold); | |
1da177e4 | 875 | spin_unlock(&hash->bh_lock); |
ce8e922c NS |
876 | (*(bp->b_relse)) (bp); |
877 | } else if (bp->b_flags & XBF_FS_MANAGED) { | |
1da177e4 | 878 | spin_unlock(&hash->bh_lock); |
1da177e4 | 879 | } else { |
ce8e922c NS |
880 | ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q))); |
881 | list_del_init(&bp->b_hash_list); | |
1da177e4 | 882 | spin_unlock(&hash->bh_lock); |
ce8e922c | 883 | xfs_buf_free(bp); |
1da177e4 LT |
884 | } |
885 | } | |
886 | } | |
887 | ||
888 | ||
889 | /* | |
890 | * Mutual exclusion on buffers. Locking model: | |
891 | * | |
892 | * Buffers associated with inodes for which buffer locking | |
893 | * is not enabled are not protected by semaphores, and are | |
894 | * assumed to be exclusively owned by the caller. There is a | |
895 | * spinlock in the buffer, used by the caller when concurrent | |
896 | * access is possible. | |
897 | */ | |
898 | ||
899 | /* | |
ce8e922c NS |
900 | * Locks a buffer object, if it is not already locked. |
901 | * Note that this in no way locks the underlying pages, so it is only | |
902 | * useful for synchronizing concurrent use of buffer objects, not for | |
903 | * synchronizing independent access to the underlying pages. | |
1da177e4 LT |
904 | */ |
905 | int | |
ce8e922c NS |
906 | xfs_buf_cond_lock( |
907 | xfs_buf_t *bp) | |
1da177e4 LT |
908 | { |
909 | int locked; | |
910 | ||
ce8e922c | 911 | locked = down_trylock(&bp->b_sema) == 0; |
1da177e4 | 912 | if (locked) { |
ce8e922c | 913 | XB_SET_OWNER(bp); |
1da177e4 | 914 | } |
ce8e922c NS |
915 | XB_TRACE(bp, "cond_lock", (long)locked); |
916 | return locked ? 0 : -EBUSY; | |
1da177e4 LT |
917 | } |
918 | ||
919 | #if defined(DEBUG) || defined(XFS_BLI_TRACE) | |
1da177e4 | 920 | int |
ce8e922c NS |
921 | xfs_buf_lock_value( |
922 | xfs_buf_t *bp) | |
1da177e4 | 923 | { |
adaa693b | 924 | return bp->b_sema.count; |
1da177e4 LT |
925 | } |
926 | #endif | |
927 | ||
928 | /* | |
ce8e922c NS |
929 | * Locks a buffer object. |
930 | * Note that this in no way locks the underlying pages, so it is only | |
931 | * useful for synchronizing concurrent use of buffer objects, not for | |
932 | * synchronizing independent access to the underlying pages. | |
1da177e4 | 933 | */ |
ce8e922c NS |
934 | void |
935 | xfs_buf_lock( | |
936 | xfs_buf_t *bp) | |
1da177e4 | 937 | { |
ce8e922c NS |
938 | XB_TRACE(bp, "lock", 0); |
939 | if (atomic_read(&bp->b_io_remaining)) | |
940 | blk_run_address_space(bp->b_target->bt_mapping); | |
941 | down(&bp->b_sema); | |
942 | XB_SET_OWNER(bp); | |
943 | XB_TRACE(bp, "locked", 0); | |
1da177e4 LT |
944 | } |
945 | ||
946 | /* | |
ce8e922c | 947 | * Releases the lock on the buffer object. |
2f926587 | 948 | * If the buffer is marked delwri but is not queued, do so before we |
ce8e922c | 949 | * unlock the buffer as we need to set flags correctly. We also need to |
2f926587 DC |
950 | * take a reference for the delwri queue because the unlocker is going to |
951 | * drop their's and they don't know we just queued it. | |
1da177e4 LT |
952 | */ |
953 | void | |
ce8e922c NS |
954 | xfs_buf_unlock( |
955 | xfs_buf_t *bp) | |
1da177e4 | 956 | { |
ce8e922c NS |
957 | if ((bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)) == XBF_DELWRI) { |
958 | atomic_inc(&bp->b_hold); | |
959 | bp->b_flags |= XBF_ASYNC; | |
960 | xfs_buf_delwri_queue(bp, 0); | |
2f926587 DC |
961 | } |
962 | ||
ce8e922c NS |
963 | XB_CLEAR_OWNER(bp); |
964 | up(&bp->b_sema); | |
965 | XB_TRACE(bp, "unlock", 0); | |
1da177e4 LT |
966 | } |
967 | ||
968 | ||
969 | /* | |
970 | * Pinning Buffer Storage in Memory | |
ce8e922c | 971 | * Ensure that no attempt to force a buffer to disk will succeed. |
1da177e4 LT |
972 | */ |
973 | void | |
ce8e922c NS |
974 | xfs_buf_pin( |
975 | xfs_buf_t *bp) | |
1da177e4 | 976 | { |
ce8e922c NS |
977 | atomic_inc(&bp->b_pin_count); |
978 | XB_TRACE(bp, "pin", (long)bp->b_pin_count.counter); | |
1da177e4 LT |
979 | } |
980 | ||
1da177e4 | 981 | void |
ce8e922c NS |
982 | xfs_buf_unpin( |
983 | xfs_buf_t *bp) | |
1da177e4 | 984 | { |
ce8e922c NS |
985 | if (atomic_dec_and_test(&bp->b_pin_count)) |
986 | wake_up_all(&bp->b_waiters); | |
987 | XB_TRACE(bp, "unpin", (long)bp->b_pin_count.counter); | |
1da177e4 LT |
988 | } |
989 | ||
990 | int | |
ce8e922c NS |
991 | xfs_buf_ispin( |
992 | xfs_buf_t *bp) | |
1da177e4 | 993 | { |
ce8e922c | 994 | return atomic_read(&bp->b_pin_count); |
1da177e4 LT |
995 | } |
996 | ||
ce8e922c NS |
997 | STATIC void |
998 | xfs_buf_wait_unpin( | |
999 | xfs_buf_t *bp) | |
1da177e4 LT |
1000 | { |
1001 | DECLARE_WAITQUEUE (wait, current); | |
1002 | ||
ce8e922c | 1003 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
1004 | return; |
1005 | ||
ce8e922c | 1006 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1007 | for (;;) { |
1008 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 1009 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 1010 | break; |
ce8e922c NS |
1011 | if (atomic_read(&bp->b_io_remaining)) |
1012 | blk_run_address_space(bp->b_target->bt_mapping); | |
1da177e4 LT |
1013 | schedule(); |
1014 | } | |
ce8e922c | 1015 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1016 | set_current_state(TASK_RUNNING); |
1017 | } | |
1018 | ||
1019 | /* | |
1020 | * Buffer Utility Routines | |
1021 | */ | |
1022 | ||
1da177e4 | 1023 | STATIC void |
ce8e922c | 1024 | xfs_buf_iodone_work( |
c4028958 | 1025 | struct work_struct *work) |
1da177e4 | 1026 | { |
c4028958 DH |
1027 | xfs_buf_t *bp = |
1028 | container_of(work, xfs_buf_t, b_iodone_work); | |
1da177e4 | 1029 | |
0bfefc46 DC |
1030 | /* |
1031 | * We can get an EOPNOTSUPP to ordered writes. Here we clear the | |
1032 | * ordered flag and reissue them. Because we can't tell the higher | |
1033 | * layers directly that they should not issue ordered I/O anymore, they | |
73f6aa4d | 1034 | * need to check if the _XFS_BARRIER_FAILED flag was set during I/O completion. |
0bfefc46 DC |
1035 | */ |
1036 | if ((bp->b_error == EOPNOTSUPP) && | |
1037 | (bp->b_flags & (XBF_ORDERED|XBF_ASYNC)) == (XBF_ORDERED|XBF_ASYNC)) { | |
1038 | XB_TRACE(bp, "ordered_retry", bp->b_iodone); | |
1039 | bp->b_flags &= ~XBF_ORDERED; | |
73f6aa4d | 1040 | bp->b_flags |= _XFS_BARRIER_FAILED; |
0bfefc46 DC |
1041 | xfs_buf_iorequest(bp); |
1042 | } else if (bp->b_iodone) | |
ce8e922c NS |
1043 | (*(bp->b_iodone))(bp); |
1044 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 LT |
1045 | xfs_buf_relse(bp); |
1046 | } | |
1047 | ||
1048 | void | |
ce8e922c NS |
1049 | xfs_buf_ioend( |
1050 | xfs_buf_t *bp, | |
1da177e4 LT |
1051 | int schedule) |
1052 | { | |
77be55a5 | 1053 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); |
ce8e922c NS |
1054 | if (bp->b_error == 0) |
1055 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1056 | |
ce8e922c | 1057 | XB_TRACE(bp, "iodone", bp->b_iodone); |
1da177e4 | 1058 | |
ce8e922c | 1059 | if ((bp->b_iodone) || (bp->b_flags & XBF_ASYNC)) { |
1da177e4 | 1060 | if (schedule) { |
c4028958 | 1061 | INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work); |
ce8e922c | 1062 | queue_work(xfslogd_workqueue, &bp->b_iodone_work); |
1da177e4 | 1063 | } else { |
c4028958 | 1064 | xfs_buf_iodone_work(&bp->b_iodone_work); |
1da177e4 LT |
1065 | } |
1066 | } else { | |
b4dd330b | 1067 | complete(&bp->b_iowait); |
1da177e4 LT |
1068 | } |
1069 | } | |
1070 | ||
1da177e4 | 1071 | void |
ce8e922c NS |
1072 | xfs_buf_ioerror( |
1073 | xfs_buf_t *bp, | |
1074 | int error) | |
1da177e4 LT |
1075 | { |
1076 | ASSERT(error >= 0 && error <= 0xffff); | |
ce8e922c NS |
1077 | bp->b_error = (unsigned short)error; |
1078 | XB_TRACE(bp, "ioerror", (unsigned long)error); | |
1da177e4 LT |
1079 | } |
1080 | ||
1da177e4 | 1081 | int |
5d765b97 CH |
1082 | xfs_bawrite( |
1083 | void *mp, | |
1084 | struct xfs_buf *bp) | |
1da177e4 | 1085 | { |
5d765b97 | 1086 | XB_TRACE(bp, "bawrite", 0); |
1da177e4 | 1087 | |
5d765b97 | 1088 | ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL); |
1da177e4 | 1089 | |
5d765b97 | 1090 | xfs_buf_delwri_dequeue(bp); |
1da177e4 | 1091 | |
5d765b97 CH |
1092 | bp->b_flags &= ~(XBF_READ | XBF_DELWRI | XBF_READ_AHEAD); |
1093 | bp->b_flags |= (XBF_WRITE | XBF_ASYNC | _XBF_RUN_QUEUES); | |
1da177e4 | 1094 | |
15ac08a8 | 1095 | bp->b_mount = mp; |
5d765b97 CH |
1096 | bp->b_strat = xfs_bdstrat_cb; |
1097 | return xfs_bdstrat_cb(bp); | |
1098 | } | |
1da177e4 | 1099 | |
5d765b97 CH |
1100 | void |
1101 | xfs_bdwrite( | |
1102 | void *mp, | |
1103 | struct xfs_buf *bp) | |
1104 | { | |
1105 | XB_TRACE(bp, "bdwrite", 0); | |
1da177e4 | 1106 | |
5d765b97 | 1107 | bp->b_strat = xfs_bdstrat_cb; |
15ac08a8 | 1108 | bp->b_mount = mp; |
1da177e4 | 1109 | |
5d765b97 CH |
1110 | bp->b_flags &= ~XBF_READ; |
1111 | bp->b_flags |= (XBF_DELWRI | XBF_ASYNC); | |
1112 | ||
1113 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1114 | } |
1115 | ||
7989cb8e | 1116 | STATIC_INLINE void |
ce8e922c NS |
1117 | _xfs_buf_ioend( |
1118 | xfs_buf_t *bp, | |
1da177e4 LT |
1119 | int schedule) |
1120 | { | |
6ab455ee CH |
1121 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) { |
1122 | bp->b_flags &= ~_XBF_PAGE_LOCKED; | |
ce8e922c | 1123 | xfs_buf_ioend(bp, schedule); |
6ab455ee | 1124 | } |
1da177e4 LT |
1125 | } |
1126 | ||
782e3b3b | 1127 | STATIC void |
ce8e922c | 1128 | xfs_buf_bio_end_io( |
1da177e4 | 1129 | struct bio *bio, |
1da177e4 LT |
1130 | int error) |
1131 | { | |
ce8e922c NS |
1132 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1133 | unsigned int blocksize = bp->b_target->bt_bsize; | |
eedb5530 | 1134 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; |
1da177e4 | 1135 | |
cfbe5267 | 1136 | xfs_buf_ioerror(bp, -error); |
1da177e4 | 1137 | |
eedb5530 | 1138 | do { |
1da177e4 LT |
1139 | struct page *page = bvec->bv_page; |
1140 | ||
948ecdb4 | 1141 | ASSERT(!PagePrivate(page)); |
ce8e922c NS |
1142 | if (unlikely(bp->b_error)) { |
1143 | if (bp->b_flags & XBF_READ) | |
eedb5530 | 1144 | ClearPageUptodate(page); |
ce8e922c | 1145 | } else if (blocksize >= PAGE_CACHE_SIZE) { |
1da177e4 LT |
1146 | SetPageUptodate(page); |
1147 | } else if (!PagePrivate(page) && | |
ce8e922c | 1148 | (bp->b_flags & _XBF_PAGE_CACHE)) { |
1da177e4 LT |
1149 | set_page_region(page, bvec->bv_offset, bvec->bv_len); |
1150 | } | |
1151 | ||
eedb5530 NS |
1152 | if (--bvec >= bio->bi_io_vec) |
1153 | prefetchw(&bvec->bv_page->flags); | |
6ab455ee CH |
1154 | |
1155 | if (bp->b_flags & _XBF_PAGE_LOCKED) | |
1156 | unlock_page(page); | |
eedb5530 | 1157 | } while (bvec >= bio->bi_io_vec); |
1da177e4 | 1158 | |
ce8e922c | 1159 | _xfs_buf_ioend(bp, 1); |
1da177e4 | 1160 | bio_put(bio); |
1da177e4 LT |
1161 | } |
1162 | ||
1163 | STATIC void | |
ce8e922c NS |
1164 | _xfs_buf_ioapply( |
1165 | xfs_buf_t *bp) | |
1da177e4 | 1166 | { |
a9759f2d | 1167 | int rw, map_i, total_nr_pages, nr_pages; |
1da177e4 | 1168 | struct bio *bio; |
ce8e922c NS |
1169 | int offset = bp->b_offset; |
1170 | int size = bp->b_count_desired; | |
1171 | sector_t sector = bp->b_bn; | |
1172 | unsigned int blocksize = bp->b_target->bt_bsize; | |
1da177e4 | 1173 | |
ce8e922c | 1174 | total_nr_pages = bp->b_page_count; |
1da177e4 LT |
1175 | map_i = 0; |
1176 | ||
ce8e922c NS |
1177 | if (bp->b_flags & XBF_ORDERED) { |
1178 | ASSERT(!(bp->b_flags & XBF_READ)); | |
f538d4da | 1179 | rw = WRITE_BARRIER; |
51bdd706 NS |
1180 | } else if (bp->b_flags & _XBF_RUN_QUEUES) { |
1181 | ASSERT(!(bp->b_flags & XBF_READ_AHEAD)); | |
1182 | bp->b_flags &= ~_XBF_RUN_QUEUES; | |
1183 | rw = (bp->b_flags & XBF_WRITE) ? WRITE_SYNC : READ_SYNC; | |
1184 | } else { | |
1185 | rw = (bp->b_flags & XBF_WRITE) ? WRITE : | |
1186 | (bp->b_flags & XBF_READ_AHEAD) ? READA : READ; | |
f538d4da CH |
1187 | } |
1188 | ||
ce8e922c | 1189 | /* Special code path for reading a sub page size buffer in -- |
1da177e4 LT |
1190 | * we populate up the whole page, and hence the other metadata |
1191 | * in the same page. This optimization is only valid when the | |
ce8e922c | 1192 | * filesystem block size is not smaller than the page size. |
1da177e4 | 1193 | */ |
ce8e922c | 1194 | if ((bp->b_buffer_length < PAGE_CACHE_SIZE) && |
6ab455ee CH |
1195 | ((bp->b_flags & (XBF_READ|_XBF_PAGE_LOCKED)) == |
1196 | (XBF_READ|_XBF_PAGE_LOCKED)) && | |
ce8e922c | 1197 | (blocksize >= PAGE_CACHE_SIZE)) { |
1da177e4 LT |
1198 | bio = bio_alloc(GFP_NOIO, 1); |
1199 | ||
ce8e922c | 1200 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1201 | bio->bi_sector = sector - (offset >> BBSHIFT); |
ce8e922c NS |
1202 | bio->bi_end_io = xfs_buf_bio_end_io; |
1203 | bio->bi_private = bp; | |
1da177e4 | 1204 | |
ce8e922c | 1205 | bio_add_page(bio, bp->b_pages[0], PAGE_CACHE_SIZE, 0); |
1da177e4 LT |
1206 | size = 0; |
1207 | ||
ce8e922c | 1208 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1209 | |
1210 | goto submit_io; | |
1211 | } | |
1212 | ||
1da177e4 | 1213 | next_chunk: |
ce8e922c | 1214 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1215 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1216 | if (nr_pages > total_nr_pages) | |
1217 | nr_pages = total_nr_pages; | |
1218 | ||
1219 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1220 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1221 | bio->bi_sector = sector; |
ce8e922c NS |
1222 | bio->bi_end_io = xfs_buf_bio_end_io; |
1223 | bio->bi_private = bp; | |
1da177e4 LT |
1224 | |
1225 | for (; size && nr_pages; nr_pages--, map_i++) { | |
ce8e922c | 1226 | int rbytes, nbytes = PAGE_CACHE_SIZE - offset; |
1da177e4 LT |
1227 | |
1228 | if (nbytes > size) | |
1229 | nbytes = size; | |
1230 | ||
ce8e922c NS |
1231 | rbytes = bio_add_page(bio, bp->b_pages[map_i], nbytes, offset); |
1232 | if (rbytes < nbytes) | |
1da177e4 LT |
1233 | break; |
1234 | ||
1235 | offset = 0; | |
1236 | sector += nbytes >> BBSHIFT; | |
1237 | size -= nbytes; | |
1238 | total_nr_pages--; | |
1239 | } | |
1240 | ||
1241 | submit_io: | |
1242 | if (likely(bio->bi_size)) { | |
1243 | submit_bio(rw, bio); | |
1244 | if (size) | |
1245 | goto next_chunk; | |
1246 | } else { | |
1247 | bio_put(bio); | |
ce8e922c | 1248 | xfs_buf_ioerror(bp, EIO); |
1da177e4 LT |
1249 | } |
1250 | } | |
1251 | ||
1da177e4 | 1252 | int |
ce8e922c NS |
1253 | xfs_buf_iorequest( |
1254 | xfs_buf_t *bp) | |
1da177e4 | 1255 | { |
ce8e922c | 1256 | XB_TRACE(bp, "iorequest", 0); |
1da177e4 | 1257 | |
ce8e922c NS |
1258 | if (bp->b_flags & XBF_DELWRI) { |
1259 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1260 | return 0; |
1261 | } | |
1262 | ||
ce8e922c NS |
1263 | if (bp->b_flags & XBF_WRITE) { |
1264 | xfs_buf_wait_unpin(bp); | |
1da177e4 LT |
1265 | } |
1266 | ||
ce8e922c | 1267 | xfs_buf_hold(bp); |
1da177e4 LT |
1268 | |
1269 | /* Set the count to 1 initially, this will stop an I/O | |
1270 | * completion callout which happens before we have started | |
ce8e922c | 1271 | * all the I/O from calling xfs_buf_ioend too early. |
1da177e4 | 1272 | */ |
ce8e922c NS |
1273 | atomic_set(&bp->b_io_remaining, 1); |
1274 | _xfs_buf_ioapply(bp); | |
1275 | _xfs_buf_ioend(bp, 0); | |
1da177e4 | 1276 | |
ce8e922c | 1277 | xfs_buf_rele(bp); |
1da177e4 LT |
1278 | return 0; |
1279 | } | |
1280 | ||
1281 | /* | |
ce8e922c NS |
1282 | * Waits for I/O to complete on the buffer supplied. |
1283 | * It returns immediately if no I/O is pending. | |
1284 | * It returns the I/O error code, if any, or 0 if there was no error. | |
1da177e4 LT |
1285 | */ |
1286 | int | |
ce8e922c NS |
1287 | xfs_buf_iowait( |
1288 | xfs_buf_t *bp) | |
1da177e4 | 1289 | { |
ce8e922c NS |
1290 | XB_TRACE(bp, "iowait", 0); |
1291 | if (atomic_read(&bp->b_io_remaining)) | |
1292 | blk_run_address_space(bp->b_target->bt_mapping); | |
b4dd330b | 1293 | wait_for_completion(&bp->b_iowait); |
ce8e922c NS |
1294 | XB_TRACE(bp, "iowaited", (long)bp->b_error); |
1295 | return bp->b_error; | |
1da177e4 LT |
1296 | } |
1297 | ||
ce8e922c NS |
1298 | xfs_caddr_t |
1299 | xfs_buf_offset( | |
1300 | xfs_buf_t *bp, | |
1da177e4 LT |
1301 | size_t offset) |
1302 | { | |
1303 | struct page *page; | |
1304 | ||
ce8e922c NS |
1305 | if (bp->b_flags & XBF_MAPPED) |
1306 | return XFS_BUF_PTR(bp) + offset; | |
1da177e4 | 1307 | |
ce8e922c NS |
1308 | offset += bp->b_offset; |
1309 | page = bp->b_pages[offset >> PAGE_CACHE_SHIFT]; | |
1310 | return (xfs_caddr_t)page_address(page) + (offset & (PAGE_CACHE_SIZE-1)); | |
1da177e4 LT |
1311 | } |
1312 | ||
1313 | /* | |
1da177e4 LT |
1314 | * Move data into or out of a buffer. |
1315 | */ | |
1316 | void | |
ce8e922c NS |
1317 | xfs_buf_iomove( |
1318 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1319 | size_t boff, /* starting buffer offset */ |
1320 | size_t bsize, /* length to copy */ | |
1321 | caddr_t data, /* data address */ | |
ce8e922c | 1322 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 LT |
1323 | { |
1324 | size_t bend, cpoff, csize; | |
1325 | struct page *page; | |
1326 | ||
1327 | bend = boff + bsize; | |
1328 | while (boff < bend) { | |
ce8e922c NS |
1329 | page = bp->b_pages[xfs_buf_btoct(boff + bp->b_offset)]; |
1330 | cpoff = xfs_buf_poff(boff + bp->b_offset); | |
1da177e4 | 1331 | csize = min_t(size_t, |
ce8e922c | 1332 | PAGE_CACHE_SIZE-cpoff, bp->b_count_desired-boff); |
1da177e4 LT |
1333 | |
1334 | ASSERT(((csize + cpoff) <= PAGE_CACHE_SIZE)); | |
1335 | ||
1336 | switch (mode) { | |
ce8e922c | 1337 | case XBRW_ZERO: |
1da177e4 LT |
1338 | memset(page_address(page) + cpoff, 0, csize); |
1339 | break; | |
ce8e922c | 1340 | case XBRW_READ: |
1da177e4 LT |
1341 | memcpy(data, page_address(page) + cpoff, csize); |
1342 | break; | |
ce8e922c | 1343 | case XBRW_WRITE: |
1da177e4 LT |
1344 | memcpy(page_address(page) + cpoff, data, csize); |
1345 | } | |
1346 | ||
1347 | boff += csize; | |
1348 | data += csize; | |
1349 | } | |
1350 | } | |
1351 | ||
1352 | /* | |
ce8e922c | 1353 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1354 | */ |
1355 | ||
1356 | /* | |
ce8e922c NS |
1357 | * Wait for any bufs with callbacks that have been submitted but |
1358 | * have not yet returned... walk the hash list for the target. | |
1da177e4 LT |
1359 | */ |
1360 | void | |
1361 | xfs_wait_buftarg( | |
1362 | xfs_buftarg_t *btp) | |
1363 | { | |
1364 | xfs_buf_t *bp, *n; | |
1365 | xfs_bufhash_t *hash; | |
1366 | uint i; | |
1367 | ||
1368 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { | |
1369 | hash = &btp->bt_hash[i]; | |
1370 | again: | |
1371 | spin_lock(&hash->bh_lock); | |
ce8e922c NS |
1372 | list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) { |
1373 | ASSERT(btp == bp->b_target); | |
1374 | if (!(bp->b_flags & XBF_FS_MANAGED)) { | |
1da177e4 | 1375 | spin_unlock(&hash->bh_lock); |
2f926587 DC |
1376 | /* |
1377 | * Catch superblock reference count leaks | |
1378 | * immediately | |
1379 | */ | |
ce8e922c | 1380 | BUG_ON(bp->b_bn == 0); |
1da177e4 LT |
1381 | delay(100); |
1382 | goto again; | |
1383 | } | |
1384 | } | |
1385 | spin_unlock(&hash->bh_lock); | |
1386 | } | |
1387 | } | |
1388 | ||
1389 | /* | |
ce8e922c NS |
1390 | * Allocate buffer hash table for a given target. |
1391 | * For devices containing metadata (i.e. not the log/realtime devices) | |
1392 | * we need to allocate a much larger hash table. | |
1da177e4 LT |
1393 | */ |
1394 | STATIC void | |
1395 | xfs_alloc_bufhash( | |
1396 | xfs_buftarg_t *btp, | |
1397 | int external) | |
1398 | { | |
1399 | unsigned int i; | |
1400 | ||
1401 | btp->bt_hashshift = external ? 3 : 8; /* 8 or 256 buckets */ | |
1402 | btp->bt_hashmask = (1 << btp->bt_hashshift) - 1; | |
1403 | btp->bt_hash = kmem_zalloc((1 << btp->bt_hashshift) * | |
93c189c1 | 1404 | sizeof(xfs_bufhash_t), KM_SLEEP | KM_LARGE); |
1da177e4 LT |
1405 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { |
1406 | spin_lock_init(&btp->bt_hash[i].bh_lock); | |
1407 | INIT_LIST_HEAD(&btp->bt_hash[i].bh_list); | |
1408 | } | |
1409 | } | |
1410 | ||
1411 | STATIC void | |
1412 | xfs_free_bufhash( | |
1413 | xfs_buftarg_t *btp) | |
1414 | { | |
f0e2d93c | 1415 | kmem_free(btp->bt_hash); |
1da177e4 LT |
1416 | btp->bt_hash = NULL; |
1417 | } | |
1418 | ||
a6867a68 | 1419 | /* |
ce8e922c | 1420 | * buftarg list for delwrite queue processing |
a6867a68 | 1421 | */ |
e6a0e9cd | 1422 | static LIST_HEAD(xfs_buftarg_list); |
7989cb8e | 1423 | static DEFINE_SPINLOCK(xfs_buftarg_lock); |
a6867a68 DC |
1424 | |
1425 | STATIC void | |
1426 | xfs_register_buftarg( | |
1427 | xfs_buftarg_t *btp) | |
1428 | { | |
1429 | spin_lock(&xfs_buftarg_lock); | |
1430 | list_add(&btp->bt_list, &xfs_buftarg_list); | |
1431 | spin_unlock(&xfs_buftarg_lock); | |
1432 | } | |
1433 | ||
1434 | STATIC void | |
1435 | xfs_unregister_buftarg( | |
1436 | xfs_buftarg_t *btp) | |
1437 | { | |
1438 | spin_lock(&xfs_buftarg_lock); | |
1439 | list_del(&btp->bt_list); | |
1440 | spin_unlock(&xfs_buftarg_lock); | |
1441 | } | |
1442 | ||
1da177e4 LT |
1443 | void |
1444 | xfs_free_buftarg( | |
b7963133 CH |
1445 | struct xfs_mount *mp, |
1446 | struct xfs_buftarg *btp) | |
1da177e4 LT |
1447 | { |
1448 | xfs_flush_buftarg(btp, 1); | |
b7963133 CH |
1449 | if (mp->m_flags & XFS_MOUNT_BARRIER) |
1450 | xfs_blkdev_issue_flush(btp); | |
1da177e4 | 1451 | xfs_free_bufhash(btp); |
ce8e922c | 1452 | iput(btp->bt_mapping->host); |
a6867a68 | 1453 | |
ce8e922c NS |
1454 | /* Unregister the buftarg first so that we don't get a |
1455 | * wakeup finding a non-existent task | |
1456 | */ | |
a6867a68 DC |
1457 | xfs_unregister_buftarg(btp); |
1458 | kthread_stop(btp->bt_task); | |
1459 | ||
f0e2d93c | 1460 | kmem_free(btp); |
1da177e4 LT |
1461 | } |
1462 | ||
1da177e4 LT |
1463 | STATIC int |
1464 | xfs_setsize_buftarg_flags( | |
1465 | xfs_buftarg_t *btp, | |
1466 | unsigned int blocksize, | |
1467 | unsigned int sectorsize, | |
1468 | int verbose) | |
1469 | { | |
ce8e922c NS |
1470 | btp->bt_bsize = blocksize; |
1471 | btp->bt_sshift = ffs(sectorsize) - 1; | |
1472 | btp->bt_smask = sectorsize - 1; | |
1da177e4 | 1473 | |
ce8e922c | 1474 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
1da177e4 LT |
1475 | printk(KERN_WARNING |
1476 | "XFS: Cannot set_blocksize to %u on device %s\n", | |
1477 | sectorsize, XFS_BUFTARG_NAME(btp)); | |
1478 | return EINVAL; | |
1479 | } | |
1480 | ||
1481 | if (verbose && | |
1482 | (PAGE_CACHE_SIZE / BITS_PER_LONG) > sectorsize) { | |
1483 | printk(KERN_WARNING | |
1484 | "XFS: %u byte sectors in use on device %s. " | |
1485 | "This is suboptimal; %u or greater is ideal.\n", | |
1486 | sectorsize, XFS_BUFTARG_NAME(btp), | |
1487 | (unsigned int)PAGE_CACHE_SIZE / BITS_PER_LONG); | |
1488 | } | |
1489 | ||
1490 | return 0; | |
1491 | } | |
1492 | ||
1493 | /* | |
ce8e922c NS |
1494 | * When allocating the initial buffer target we have not yet |
1495 | * read in the superblock, so don't know what sized sectors | |
1496 | * are being used is at this early stage. Play safe. | |
1497 | */ | |
1da177e4 LT |
1498 | STATIC int |
1499 | xfs_setsize_buftarg_early( | |
1500 | xfs_buftarg_t *btp, | |
1501 | struct block_device *bdev) | |
1502 | { | |
1503 | return xfs_setsize_buftarg_flags(btp, | |
e1defc4f | 1504 | PAGE_CACHE_SIZE, bdev_logical_block_size(bdev), 0); |
1da177e4 LT |
1505 | } |
1506 | ||
1507 | int | |
1508 | xfs_setsize_buftarg( | |
1509 | xfs_buftarg_t *btp, | |
1510 | unsigned int blocksize, | |
1511 | unsigned int sectorsize) | |
1512 | { | |
1513 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | |
1514 | } | |
1515 | ||
1516 | STATIC int | |
1517 | xfs_mapping_buftarg( | |
1518 | xfs_buftarg_t *btp, | |
1519 | struct block_device *bdev) | |
1520 | { | |
1521 | struct backing_dev_info *bdi; | |
1522 | struct inode *inode; | |
1523 | struct address_space *mapping; | |
f5e54d6e | 1524 | static const struct address_space_operations mapping_aops = { |
1da177e4 | 1525 | .sync_page = block_sync_page, |
e965f963 | 1526 | .migratepage = fail_migrate_page, |
1da177e4 LT |
1527 | }; |
1528 | ||
1529 | inode = new_inode(bdev->bd_inode->i_sb); | |
1530 | if (!inode) { | |
1531 | printk(KERN_WARNING | |
1532 | "XFS: Cannot allocate mapping inode for device %s\n", | |
1533 | XFS_BUFTARG_NAME(btp)); | |
1534 | return ENOMEM; | |
1535 | } | |
1536 | inode->i_mode = S_IFBLK; | |
1537 | inode->i_bdev = bdev; | |
1538 | inode->i_rdev = bdev->bd_dev; | |
1539 | bdi = blk_get_backing_dev_info(bdev); | |
1540 | if (!bdi) | |
1541 | bdi = &default_backing_dev_info; | |
1542 | mapping = &inode->i_data; | |
1543 | mapping->a_ops = &mapping_aops; | |
1544 | mapping->backing_dev_info = bdi; | |
1545 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
ce8e922c | 1546 | btp->bt_mapping = mapping; |
1da177e4 LT |
1547 | return 0; |
1548 | } | |
1549 | ||
a6867a68 DC |
1550 | STATIC int |
1551 | xfs_alloc_delwrite_queue( | |
1552 | xfs_buftarg_t *btp) | |
1553 | { | |
1554 | int error = 0; | |
1555 | ||
1556 | INIT_LIST_HEAD(&btp->bt_list); | |
1557 | INIT_LIST_HEAD(&btp->bt_delwrite_queue); | |
007c61c6 | 1558 | spin_lock_init(&btp->bt_delwrite_lock); |
a6867a68 DC |
1559 | btp->bt_flags = 0; |
1560 | btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd"); | |
1561 | if (IS_ERR(btp->bt_task)) { | |
1562 | error = PTR_ERR(btp->bt_task); | |
1563 | goto out_error; | |
1564 | } | |
1565 | xfs_register_buftarg(btp); | |
1566 | out_error: | |
1567 | return error; | |
1568 | } | |
1569 | ||
1da177e4 LT |
1570 | xfs_buftarg_t * |
1571 | xfs_alloc_buftarg( | |
1572 | struct block_device *bdev, | |
1573 | int external) | |
1574 | { | |
1575 | xfs_buftarg_t *btp; | |
1576 | ||
1577 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP); | |
1578 | ||
ce8e922c NS |
1579 | btp->bt_dev = bdev->bd_dev; |
1580 | btp->bt_bdev = bdev; | |
1da177e4 LT |
1581 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1582 | goto error; | |
1583 | if (xfs_mapping_buftarg(btp, bdev)) | |
1584 | goto error; | |
a6867a68 DC |
1585 | if (xfs_alloc_delwrite_queue(btp)) |
1586 | goto error; | |
1da177e4 LT |
1587 | xfs_alloc_bufhash(btp, external); |
1588 | return btp; | |
1589 | ||
1590 | error: | |
f0e2d93c | 1591 | kmem_free(btp); |
1da177e4 LT |
1592 | return NULL; |
1593 | } | |
1594 | ||
1595 | ||
1596 | /* | |
ce8e922c | 1597 | * Delayed write buffer handling |
1da177e4 | 1598 | */ |
1da177e4 | 1599 | STATIC void |
ce8e922c NS |
1600 | xfs_buf_delwri_queue( |
1601 | xfs_buf_t *bp, | |
1da177e4 LT |
1602 | int unlock) |
1603 | { | |
ce8e922c NS |
1604 | struct list_head *dwq = &bp->b_target->bt_delwrite_queue; |
1605 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; | |
a6867a68 | 1606 | |
ce8e922c NS |
1607 | XB_TRACE(bp, "delwri_q", (long)unlock); |
1608 | ASSERT((bp->b_flags&(XBF_DELWRI|XBF_ASYNC)) == (XBF_DELWRI|XBF_ASYNC)); | |
1da177e4 | 1609 | |
a6867a68 | 1610 | spin_lock(dwlk); |
1da177e4 | 1611 | /* If already in the queue, dequeue and place at tail */ |
ce8e922c NS |
1612 | if (!list_empty(&bp->b_list)) { |
1613 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1614 | if (unlock) | |
1615 | atomic_dec(&bp->b_hold); | |
1616 | list_del(&bp->b_list); | |
1da177e4 LT |
1617 | } |
1618 | ||
ce8e922c NS |
1619 | bp->b_flags |= _XBF_DELWRI_Q; |
1620 | list_add_tail(&bp->b_list, dwq); | |
1621 | bp->b_queuetime = jiffies; | |
a6867a68 | 1622 | spin_unlock(dwlk); |
1da177e4 LT |
1623 | |
1624 | if (unlock) | |
ce8e922c | 1625 | xfs_buf_unlock(bp); |
1da177e4 LT |
1626 | } |
1627 | ||
1628 | void | |
ce8e922c NS |
1629 | xfs_buf_delwri_dequeue( |
1630 | xfs_buf_t *bp) | |
1da177e4 | 1631 | { |
ce8e922c | 1632 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; |
1da177e4 LT |
1633 | int dequeued = 0; |
1634 | ||
a6867a68 | 1635 | spin_lock(dwlk); |
ce8e922c NS |
1636 | if ((bp->b_flags & XBF_DELWRI) && !list_empty(&bp->b_list)) { |
1637 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1638 | list_del_init(&bp->b_list); | |
1da177e4 LT |
1639 | dequeued = 1; |
1640 | } | |
ce8e922c | 1641 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); |
a6867a68 | 1642 | spin_unlock(dwlk); |
1da177e4 LT |
1643 | |
1644 | if (dequeued) | |
ce8e922c | 1645 | xfs_buf_rele(bp); |
1da177e4 | 1646 | |
ce8e922c | 1647 | XB_TRACE(bp, "delwri_dq", (long)dequeued); |
1da177e4 LT |
1648 | } |
1649 | ||
1650 | STATIC void | |
ce8e922c | 1651 | xfs_buf_runall_queues( |
1da177e4 LT |
1652 | struct workqueue_struct *queue) |
1653 | { | |
1654 | flush_workqueue(queue); | |
1655 | } | |
1656 | ||
1da177e4 | 1657 | STATIC int |
23ea4032 | 1658 | xfsbufd_wakeup( |
15c84a47 NS |
1659 | int priority, |
1660 | gfp_t mask) | |
1da177e4 | 1661 | { |
da7f93e9 | 1662 | xfs_buftarg_t *btp; |
a6867a68 DC |
1663 | |
1664 | spin_lock(&xfs_buftarg_lock); | |
da7f93e9 | 1665 | list_for_each_entry(btp, &xfs_buftarg_list, bt_list) { |
ce8e922c | 1666 | if (test_bit(XBT_FORCE_SLEEP, &btp->bt_flags)) |
a6867a68 | 1667 | continue; |
ce8e922c | 1668 | set_bit(XBT_FORCE_FLUSH, &btp->bt_flags); |
a6867a68 DC |
1669 | wake_up_process(btp->bt_task); |
1670 | } | |
1671 | spin_unlock(&xfs_buftarg_lock); | |
1da177e4 LT |
1672 | return 0; |
1673 | } | |
1674 | ||
585e6d88 DC |
1675 | /* |
1676 | * Move as many buffers as specified to the supplied list | |
1677 | * idicating if we skipped any buffers to prevent deadlocks. | |
1678 | */ | |
1679 | STATIC int | |
1680 | xfs_buf_delwri_split( | |
1681 | xfs_buftarg_t *target, | |
1682 | struct list_head *list, | |
5e6a07df | 1683 | unsigned long age) |
585e6d88 DC |
1684 | { |
1685 | xfs_buf_t *bp, *n; | |
1686 | struct list_head *dwq = &target->bt_delwrite_queue; | |
1687 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1688 | int skipped = 0; | |
5e6a07df | 1689 | int force; |
585e6d88 | 1690 | |
5e6a07df | 1691 | force = test_and_clear_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
585e6d88 DC |
1692 | INIT_LIST_HEAD(list); |
1693 | spin_lock(dwlk); | |
1694 | list_for_each_entry_safe(bp, n, dwq, b_list) { | |
1695 | XB_TRACE(bp, "walkq1", (long)xfs_buf_ispin(bp)); | |
1696 | ASSERT(bp->b_flags & XBF_DELWRI); | |
1697 | ||
1698 | if (!xfs_buf_ispin(bp) && !xfs_buf_cond_lock(bp)) { | |
5e6a07df | 1699 | if (!force && |
585e6d88 DC |
1700 | time_before(jiffies, bp->b_queuetime + age)) { |
1701 | xfs_buf_unlock(bp); | |
1702 | break; | |
1703 | } | |
1704 | ||
1705 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q| | |
1706 | _XBF_RUN_QUEUES); | |
1707 | bp->b_flags |= XBF_WRITE; | |
1708 | list_move_tail(&bp->b_list, list); | |
1709 | } else | |
1710 | skipped++; | |
1711 | } | |
1712 | spin_unlock(dwlk); | |
1713 | ||
1714 | return skipped; | |
1715 | ||
1716 | } | |
1717 | ||
1da177e4 | 1718 | STATIC int |
23ea4032 | 1719 | xfsbufd( |
585e6d88 | 1720 | void *data) |
1da177e4 | 1721 | { |
585e6d88 DC |
1722 | struct list_head tmp; |
1723 | xfs_buftarg_t *target = (xfs_buftarg_t *)data; | |
1724 | int count; | |
1725 | xfs_buf_t *bp; | |
1da177e4 | 1726 | |
1da177e4 LT |
1727 | current->flags |= PF_MEMALLOC; |
1728 | ||
978c7b2f RW |
1729 | set_freezable(); |
1730 | ||
1da177e4 | 1731 | do { |
3e1d1d28 | 1732 | if (unlikely(freezing(current))) { |
ce8e922c | 1733 | set_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
3e1d1d28 | 1734 | refrigerator(); |
abd0cf7a | 1735 | } else { |
ce8e922c | 1736 | clear_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
abd0cf7a | 1737 | } |
1da177e4 | 1738 | |
15c84a47 NS |
1739 | schedule_timeout_interruptible( |
1740 | xfs_buf_timer_centisecs * msecs_to_jiffies(10)); | |
1da177e4 | 1741 | |
585e6d88 | 1742 | xfs_buf_delwri_split(target, &tmp, |
5e6a07df | 1743 | xfs_buf_age_centisecs * msecs_to_jiffies(10)); |
1da177e4 | 1744 | |
585e6d88 | 1745 | count = 0; |
1da177e4 | 1746 | while (!list_empty(&tmp)) { |
ce8e922c NS |
1747 | bp = list_entry(tmp.next, xfs_buf_t, b_list); |
1748 | ASSERT(target == bp->b_target); | |
1da177e4 | 1749 | |
ce8e922c NS |
1750 | list_del_init(&bp->b_list); |
1751 | xfs_buf_iostrategy(bp); | |
585e6d88 | 1752 | count++; |
1da177e4 LT |
1753 | } |
1754 | ||
3a011a17 FB |
1755 | if (as_list_len > 0) |
1756 | purge_addresses(); | |
f07c2250 NS |
1757 | if (count) |
1758 | blk_run_address_space(target->bt_mapping); | |
1da177e4 | 1759 | |
4df08c52 | 1760 | } while (!kthread_should_stop()); |
1da177e4 | 1761 | |
4df08c52 | 1762 | return 0; |
1da177e4 LT |
1763 | } |
1764 | ||
1765 | /* | |
ce8e922c NS |
1766 | * Go through all incore buffers, and release buffers if they belong to |
1767 | * the given device. This is used in filesystem error handling to | |
1768 | * preserve the consistency of its metadata. | |
1da177e4 LT |
1769 | */ |
1770 | int | |
1771 | xfs_flush_buftarg( | |
585e6d88 DC |
1772 | xfs_buftarg_t *target, |
1773 | int wait) | |
1da177e4 | 1774 | { |
585e6d88 DC |
1775 | struct list_head tmp; |
1776 | xfs_buf_t *bp, *n; | |
1777 | int pincount = 0; | |
1da177e4 | 1778 | |
c626d174 | 1779 | xfs_buf_runall_queues(xfsconvertd_workqueue); |
ce8e922c NS |
1780 | xfs_buf_runall_queues(xfsdatad_workqueue); |
1781 | xfs_buf_runall_queues(xfslogd_workqueue); | |
1da177e4 | 1782 | |
5e6a07df DC |
1783 | set_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
1784 | pincount = xfs_buf_delwri_split(target, &tmp, 0); | |
1da177e4 LT |
1785 | |
1786 | /* | |
1787 | * Dropped the delayed write list lock, now walk the temporary list | |
1788 | */ | |
ce8e922c | 1789 | list_for_each_entry_safe(bp, n, &tmp, b_list) { |
585e6d88 | 1790 | ASSERT(target == bp->b_target); |
1da177e4 | 1791 | if (wait) |
ce8e922c | 1792 | bp->b_flags &= ~XBF_ASYNC; |
1da177e4 | 1793 | else |
ce8e922c | 1794 | list_del_init(&bp->b_list); |
1da177e4 | 1795 | |
ce8e922c | 1796 | xfs_buf_iostrategy(bp); |
1da177e4 LT |
1797 | } |
1798 | ||
f07c2250 NS |
1799 | if (wait) |
1800 | blk_run_address_space(target->bt_mapping); | |
1801 | ||
1da177e4 LT |
1802 | /* |
1803 | * Remaining list items must be flushed before returning | |
1804 | */ | |
1805 | while (!list_empty(&tmp)) { | |
ce8e922c | 1806 | bp = list_entry(tmp.next, xfs_buf_t, b_list); |
1da177e4 | 1807 | |
ce8e922c NS |
1808 | list_del_init(&bp->b_list); |
1809 | xfs_iowait(bp); | |
1810 | xfs_buf_relse(bp); | |
1da177e4 LT |
1811 | } |
1812 | ||
1da177e4 LT |
1813 | return pincount; |
1814 | } | |
1815 | ||
04d8b284 | 1816 | int __init |
ce8e922c | 1817 | xfs_buf_init(void) |
1da177e4 | 1818 | { |
ce8e922c | 1819 | #ifdef XFS_BUF_TRACE |
5695ef46 | 1820 | xfs_buf_trace_buf = ktrace_alloc(XFS_BUF_TRACE_SIZE, KM_NOFS); |
04d8b284 CH |
1821 | #endif |
1822 | ||
8758280f NS |
1823 | xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf", |
1824 | KM_ZONE_HWALIGN, NULL); | |
ce8e922c | 1825 | if (!xfs_buf_zone) |
04d8b284 CH |
1826 | goto out_free_trace_buf; |
1827 | ||
b4337692 | 1828 | xfslogd_workqueue = create_workqueue("xfslogd"); |
23ea4032 | 1829 | if (!xfslogd_workqueue) |
04d8b284 | 1830 | goto out_free_buf_zone; |
1da177e4 | 1831 | |
b4337692 | 1832 | xfsdatad_workqueue = create_workqueue("xfsdatad"); |
23ea4032 CH |
1833 | if (!xfsdatad_workqueue) |
1834 | goto out_destroy_xfslogd_workqueue; | |
1da177e4 | 1835 | |
c626d174 DC |
1836 | xfsconvertd_workqueue = create_workqueue("xfsconvertd"); |
1837 | if (!xfsconvertd_workqueue) | |
1838 | goto out_destroy_xfsdatad_workqueue; | |
1839 | ||
8e1f936b | 1840 | register_shrinker(&xfs_buf_shake); |
23ea4032 | 1841 | return 0; |
1da177e4 | 1842 | |
c626d174 DC |
1843 | out_destroy_xfsdatad_workqueue: |
1844 | destroy_workqueue(xfsdatad_workqueue); | |
23ea4032 CH |
1845 | out_destroy_xfslogd_workqueue: |
1846 | destroy_workqueue(xfslogd_workqueue); | |
23ea4032 | 1847 | out_free_buf_zone: |
ce8e922c | 1848 | kmem_zone_destroy(xfs_buf_zone); |
04d8b284 | 1849 | out_free_trace_buf: |
ce8e922c NS |
1850 | #ifdef XFS_BUF_TRACE |
1851 | ktrace_free(xfs_buf_trace_buf); | |
23ea4032 | 1852 | #endif |
8758280f | 1853 | return -ENOMEM; |
1da177e4 LT |
1854 | } |
1855 | ||
1da177e4 | 1856 | void |
ce8e922c | 1857 | xfs_buf_terminate(void) |
1da177e4 | 1858 | { |
8e1f936b | 1859 | unregister_shrinker(&xfs_buf_shake); |
c626d174 | 1860 | destroy_workqueue(xfsconvertd_workqueue); |
04d8b284 CH |
1861 | destroy_workqueue(xfsdatad_workqueue); |
1862 | destroy_workqueue(xfslogd_workqueue); | |
ce8e922c NS |
1863 | kmem_zone_destroy(xfs_buf_zone); |
1864 | #ifdef XFS_BUF_TRACE | |
1865 | ktrace_free(xfs_buf_trace_buf); | |
1da177e4 | 1866 | #endif |
1da177e4 | 1867 | } |
e6a0e9cd TS |
1868 | |
1869 | #ifdef CONFIG_KDB_MODULES | |
1870 | struct list_head * | |
1871 | xfs_get_buftarg_list(void) | |
1872 | { | |
1873 | return &xfs_buftarg_list; | |
1874 | } | |
1875 | #endif |