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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 | |
7989cb8e | 37 | static kmem_zone_t *xfs_buf_zone; |
a6867a68 | 38 | STATIC int xfsbufd(void *); |
27496a8c | 39 | STATIC int xfsbufd_wakeup(int, gfp_t); |
ce8e922c | 40 | STATIC void xfs_buf_delwri_queue(xfs_buf_t *, int); |
8e1f936b RR |
41 | static struct shrinker xfs_buf_shake = { |
42 | .shrink = xfsbufd_wakeup, | |
43 | .seeks = DEFAULT_SEEKS, | |
44 | }; | |
23ea4032 | 45 | |
7989cb8e | 46 | static struct workqueue_struct *xfslogd_workqueue; |
0829c360 | 47 | struct workqueue_struct *xfsdatad_workqueue; |
1da177e4 | 48 | |
ce8e922c | 49 | #ifdef XFS_BUF_TRACE |
1da177e4 | 50 | void |
ce8e922c NS |
51 | xfs_buf_trace( |
52 | xfs_buf_t *bp, | |
1da177e4 LT |
53 | char *id, |
54 | void *data, | |
55 | void *ra) | |
56 | { | |
ce8e922c NS |
57 | ktrace_enter(xfs_buf_trace_buf, |
58 | bp, id, | |
59 | (void *)(unsigned long)bp->b_flags, | |
60 | (void *)(unsigned long)bp->b_hold.counter, | |
61 | (void *)(unsigned long)bp->b_sema.count.counter, | |
1da177e4 LT |
62 | (void *)current, |
63 | data, ra, | |
ce8e922c NS |
64 | (void *)(unsigned long)((bp->b_file_offset>>32) & 0xffffffff), |
65 | (void *)(unsigned long)(bp->b_file_offset & 0xffffffff), | |
66 | (void *)(unsigned long)bp->b_buffer_length, | |
1da177e4 LT |
67 | NULL, NULL, NULL, NULL, NULL); |
68 | } | |
ce8e922c NS |
69 | ktrace_t *xfs_buf_trace_buf; |
70 | #define XFS_BUF_TRACE_SIZE 4096 | |
71 | #define XB_TRACE(bp, id, data) \ | |
72 | xfs_buf_trace(bp, id, (void *)data, (void *)__builtin_return_address(0)) | |
1da177e4 | 73 | #else |
ce8e922c | 74 | #define XB_TRACE(bp, id, data) do { } while (0) |
1da177e4 LT |
75 | #endif |
76 | ||
ce8e922c NS |
77 | #ifdef XFS_BUF_LOCK_TRACKING |
78 | # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid) | |
79 | # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1) | |
80 | # define XB_GET_OWNER(bp) ((bp)->b_last_holder) | |
1da177e4 | 81 | #else |
ce8e922c NS |
82 | # define XB_SET_OWNER(bp) do { } while (0) |
83 | # define XB_CLEAR_OWNER(bp) do { } while (0) | |
84 | # define XB_GET_OWNER(bp) do { } while (0) | |
1da177e4 LT |
85 | #endif |
86 | ||
ce8e922c NS |
87 | #define xb_to_gfp(flags) \ |
88 | ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : \ | |
89 | ((flags) & XBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN) | |
1da177e4 | 90 | |
ce8e922c NS |
91 | #define xb_to_km(flags) \ |
92 | (((flags) & XBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP) | |
1da177e4 | 93 | |
ce8e922c NS |
94 | #define xfs_buf_allocate(flags) \ |
95 | kmem_zone_alloc(xfs_buf_zone, xb_to_km(flags)) | |
96 | #define xfs_buf_deallocate(bp) \ | |
97 | kmem_zone_free(xfs_buf_zone, (bp)); | |
1da177e4 LT |
98 | |
99 | /* | |
ce8e922c | 100 | * Page Region interfaces. |
1da177e4 | 101 | * |
ce8e922c NS |
102 | * For pages in filesystems where the blocksize is smaller than the |
103 | * pagesize, we use the page->private field (long) to hold a bitmap | |
104 | * of uptodate regions within the page. | |
1da177e4 | 105 | * |
ce8e922c | 106 | * Each such region is "bytes per page / bits per long" bytes long. |
1da177e4 | 107 | * |
ce8e922c NS |
108 | * NBPPR == number-of-bytes-per-page-region |
109 | * BTOPR == bytes-to-page-region (rounded up) | |
110 | * BTOPRT == bytes-to-page-region-truncated (rounded down) | |
1da177e4 LT |
111 | */ |
112 | #if (BITS_PER_LONG == 32) | |
113 | #define PRSHIFT (PAGE_CACHE_SHIFT - 5) /* (32 == 1<<5) */ | |
114 | #elif (BITS_PER_LONG == 64) | |
115 | #define PRSHIFT (PAGE_CACHE_SHIFT - 6) /* (64 == 1<<6) */ | |
116 | #else | |
117 | #error BITS_PER_LONG must be 32 or 64 | |
118 | #endif | |
119 | #define NBPPR (PAGE_CACHE_SIZE/BITS_PER_LONG) | |
120 | #define BTOPR(b) (((unsigned int)(b) + (NBPPR - 1)) >> PRSHIFT) | |
121 | #define BTOPRT(b) (((unsigned int)(b) >> PRSHIFT)) | |
122 | ||
123 | STATIC unsigned long | |
124 | page_region_mask( | |
125 | size_t offset, | |
126 | size_t length) | |
127 | { | |
128 | unsigned long mask; | |
129 | int first, final; | |
130 | ||
131 | first = BTOPR(offset); | |
132 | final = BTOPRT(offset + length - 1); | |
133 | first = min(first, final); | |
134 | ||
135 | mask = ~0UL; | |
136 | mask <<= BITS_PER_LONG - (final - first); | |
137 | mask >>= BITS_PER_LONG - (final); | |
138 | ||
139 | ASSERT(offset + length <= PAGE_CACHE_SIZE); | |
140 | ASSERT((final - first) < BITS_PER_LONG && (final - first) >= 0); | |
141 | ||
142 | return mask; | |
143 | } | |
144 | ||
7989cb8e | 145 | STATIC_INLINE void |
1da177e4 LT |
146 | set_page_region( |
147 | struct page *page, | |
148 | size_t offset, | |
149 | size_t length) | |
150 | { | |
4c21e2f2 HD |
151 | set_page_private(page, |
152 | page_private(page) | page_region_mask(offset, length)); | |
153 | if (page_private(page) == ~0UL) | |
1da177e4 LT |
154 | SetPageUptodate(page); |
155 | } | |
156 | ||
7989cb8e | 157 | STATIC_INLINE int |
1da177e4 LT |
158 | test_page_region( |
159 | struct page *page, | |
160 | size_t offset, | |
161 | size_t length) | |
162 | { | |
163 | unsigned long mask = page_region_mask(offset, length); | |
164 | ||
4c21e2f2 | 165 | return (mask && (page_private(page) & mask) == mask); |
1da177e4 LT |
166 | } |
167 | ||
168 | /* | |
ce8e922c | 169 | * Mapping of multi-page buffers into contiguous virtual space |
1da177e4 LT |
170 | */ |
171 | ||
172 | typedef struct a_list { | |
173 | void *vm_addr; | |
174 | struct a_list *next; | |
175 | } a_list_t; | |
176 | ||
7989cb8e DC |
177 | static a_list_t *as_free_head; |
178 | static int as_list_len; | |
179 | static DEFINE_SPINLOCK(as_lock); | |
1da177e4 LT |
180 | |
181 | /* | |
ce8e922c | 182 | * Try to batch vunmaps because they are costly. |
1da177e4 LT |
183 | */ |
184 | STATIC void | |
185 | free_address( | |
186 | void *addr) | |
187 | { | |
188 | a_list_t *aentry; | |
189 | ||
7f015072 JF |
190 | #ifdef CONFIG_XEN |
191 | /* | |
192 | * Xen needs to be able to make sure it can get an exclusive | |
193 | * RO mapping of pages it wants to turn into a pagetable. If | |
194 | * a newly allocated page is also still being vmap()ed by xfs, | |
195 | * it will cause pagetable construction to fail. This is a | |
196 | * quick workaround to always eagerly unmap pages so that Xen | |
197 | * is happy. | |
198 | */ | |
199 | vunmap(addr); | |
200 | return; | |
201 | #endif | |
202 | ||
7b04d717 | 203 | aentry = kmalloc(sizeof(a_list_t), GFP_NOWAIT); |
1da177e4 LT |
204 | if (likely(aentry)) { |
205 | spin_lock(&as_lock); | |
206 | aentry->next = as_free_head; | |
207 | aentry->vm_addr = addr; | |
208 | as_free_head = aentry; | |
209 | as_list_len++; | |
210 | spin_unlock(&as_lock); | |
211 | } else { | |
212 | vunmap(addr); | |
213 | } | |
214 | } | |
215 | ||
216 | STATIC void | |
217 | purge_addresses(void) | |
218 | { | |
219 | a_list_t *aentry, *old; | |
220 | ||
221 | if (as_free_head == NULL) | |
222 | return; | |
223 | ||
224 | spin_lock(&as_lock); | |
225 | aentry = as_free_head; | |
226 | as_free_head = NULL; | |
227 | as_list_len = 0; | |
228 | spin_unlock(&as_lock); | |
229 | ||
230 | while ((old = aentry) != NULL) { | |
231 | vunmap(aentry->vm_addr); | |
232 | aentry = aentry->next; | |
233 | kfree(old); | |
234 | } | |
235 | } | |
236 | ||
237 | /* | |
ce8e922c | 238 | * Internal xfs_buf_t object manipulation |
1da177e4 LT |
239 | */ |
240 | ||
241 | STATIC void | |
ce8e922c NS |
242 | _xfs_buf_initialize( |
243 | xfs_buf_t *bp, | |
1da177e4 | 244 | xfs_buftarg_t *target, |
204ab25f | 245 | xfs_off_t range_base, |
1da177e4 | 246 | size_t range_length, |
ce8e922c | 247 | xfs_buf_flags_t flags) |
1da177e4 LT |
248 | { |
249 | /* | |
ce8e922c | 250 | * We don't want certain flags to appear in b_flags. |
1da177e4 | 251 | */ |
ce8e922c NS |
252 | flags &= ~(XBF_LOCK|XBF_MAPPED|XBF_DONT_BLOCK|XBF_READ_AHEAD); |
253 | ||
254 | memset(bp, 0, sizeof(xfs_buf_t)); | |
255 | atomic_set(&bp->b_hold, 1); | |
256 | init_MUTEX_LOCKED(&bp->b_iodonesema); | |
257 | INIT_LIST_HEAD(&bp->b_list); | |
258 | INIT_LIST_HEAD(&bp->b_hash_list); | |
259 | init_MUTEX_LOCKED(&bp->b_sema); /* held, no waiters */ | |
260 | XB_SET_OWNER(bp); | |
261 | bp->b_target = target; | |
262 | bp->b_file_offset = range_base; | |
1da177e4 LT |
263 | /* |
264 | * Set buffer_length and count_desired to the same value initially. | |
265 | * I/O routines should use count_desired, which will be the same in | |
266 | * most cases but may be reset (e.g. XFS recovery). | |
267 | */ | |
ce8e922c NS |
268 | bp->b_buffer_length = bp->b_count_desired = range_length; |
269 | bp->b_flags = flags; | |
270 | bp->b_bn = XFS_BUF_DADDR_NULL; | |
271 | atomic_set(&bp->b_pin_count, 0); | |
272 | init_waitqueue_head(&bp->b_waiters); | |
273 | ||
274 | XFS_STATS_INC(xb_create); | |
275 | XB_TRACE(bp, "initialize", target); | |
1da177e4 LT |
276 | } |
277 | ||
278 | /* | |
ce8e922c NS |
279 | * Allocate a page array capable of holding a specified number |
280 | * of pages, and point the page buf at it. | |
1da177e4 LT |
281 | */ |
282 | STATIC int | |
ce8e922c NS |
283 | _xfs_buf_get_pages( |
284 | xfs_buf_t *bp, | |
1da177e4 | 285 | int page_count, |
ce8e922c | 286 | xfs_buf_flags_t flags) |
1da177e4 LT |
287 | { |
288 | /* Make sure that we have a page list */ | |
ce8e922c NS |
289 | if (bp->b_pages == NULL) { |
290 | bp->b_offset = xfs_buf_poff(bp->b_file_offset); | |
291 | bp->b_page_count = page_count; | |
292 | if (page_count <= XB_PAGES) { | |
293 | bp->b_pages = bp->b_page_array; | |
1da177e4 | 294 | } else { |
ce8e922c NS |
295 | bp->b_pages = kmem_alloc(sizeof(struct page *) * |
296 | page_count, xb_to_km(flags)); | |
297 | if (bp->b_pages == NULL) | |
1da177e4 LT |
298 | return -ENOMEM; |
299 | } | |
ce8e922c | 300 | memset(bp->b_pages, 0, sizeof(struct page *) * page_count); |
1da177e4 LT |
301 | } |
302 | return 0; | |
303 | } | |
304 | ||
305 | /* | |
ce8e922c | 306 | * Frees b_pages if it was allocated. |
1da177e4 LT |
307 | */ |
308 | STATIC void | |
ce8e922c | 309 | _xfs_buf_free_pages( |
1da177e4 LT |
310 | xfs_buf_t *bp) |
311 | { | |
ce8e922c NS |
312 | if (bp->b_pages != bp->b_page_array) { |
313 | kmem_free(bp->b_pages, | |
314 | bp->b_page_count * sizeof(struct page *)); | |
1da177e4 LT |
315 | } |
316 | } | |
317 | ||
318 | /* | |
319 | * Releases the specified buffer. | |
320 | * | |
321 | * The modification state of any associated pages is left unchanged. | |
ce8e922c | 322 | * The buffer most not be on any hash - use xfs_buf_rele instead for |
1da177e4 LT |
323 | * hashed and refcounted buffers |
324 | */ | |
325 | void | |
ce8e922c | 326 | xfs_buf_free( |
1da177e4 LT |
327 | xfs_buf_t *bp) |
328 | { | |
ce8e922c | 329 | XB_TRACE(bp, "free", 0); |
1da177e4 | 330 | |
ce8e922c | 331 | ASSERT(list_empty(&bp->b_hash_list)); |
1da177e4 | 332 | |
1fa40b01 | 333 | if (bp->b_flags & (_XBF_PAGE_CACHE|_XBF_PAGES)) { |
1da177e4 LT |
334 | uint i; |
335 | ||
ce8e922c NS |
336 | if ((bp->b_flags & XBF_MAPPED) && (bp->b_page_count > 1)) |
337 | free_address(bp->b_addr - bp->b_offset); | |
1da177e4 | 338 | |
948ecdb4 NS |
339 | for (i = 0; i < bp->b_page_count; i++) { |
340 | struct page *page = bp->b_pages[i]; | |
341 | ||
1fa40b01 CH |
342 | if (bp->b_flags & _XBF_PAGE_CACHE) |
343 | ASSERT(!PagePrivate(page)); | |
948ecdb4 NS |
344 | page_cache_release(page); |
345 | } | |
ce8e922c | 346 | _xfs_buf_free_pages(bp); |
1da177e4 LT |
347 | } |
348 | ||
ce8e922c | 349 | xfs_buf_deallocate(bp); |
1da177e4 LT |
350 | } |
351 | ||
352 | /* | |
353 | * Finds all pages for buffer in question and builds it's page list. | |
354 | */ | |
355 | STATIC int | |
ce8e922c | 356 | _xfs_buf_lookup_pages( |
1da177e4 LT |
357 | xfs_buf_t *bp, |
358 | uint flags) | |
359 | { | |
ce8e922c NS |
360 | struct address_space *mapping = bp->b_target->bt_mapping; |
361 | size_t blocksize = bp->b_target->bt_bsize; | |
362 | size_t size = bp->b_count_desired; | |
1da177e4 | 363 | size_t nbytes, offset; |
ce8e922c | 364 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 LT |
365 | unsigned short page_count, i; |
366 | pgoff_t first; | |
204ab25f | 367 | xfs_off_t end; |
1da177e4 LT |
368 | int error; |
369 | ||
ce8e922c NS |
370 | end = bp->b_file_offset + bp->b_buffer_length; |
371 | page_count = xfs_buf_btoc(end) - xfs_buf_btoct(bp->b_file_offset); | |
1da177e4 | 372 | |
ce8e922c | 373 | error = _xfs_buf_get_pages(bp, page_count, flags); |
1da177e4 LT |
374 | if (unlikely(error)) |
375 | return error; | |
ce8e922c | 376 | bp->b_flags |= _XBF_PAGE_CACHE; |
1da177e4 | 377 | |
ce8e922c NS |
378 | offset = bp->b_offset; |
379 | first = bp->b_file_offset >> PAGE_CACHE_SHIFT; | |
1da177e4 | 380 | |
ce8e922c | 381 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
382 | struct page *page; |
383 | uint retries = 0; | |
384 | ||
385 | retry: | |
386 | page = find_or_create_page(mapping, first + i, gfp_mask); | |
387 | if (unlikely(page == NULL)) { | |
ce8e922c NS |
388 | if (flags & XBF_READ_AHEAD) { |
389 | bp->b_page_count = i; | |
1da177e4 LT |
390 | return -ENOMEM; |
391 | } | |
392 | ||
393 | /* | |
394 | * This could deadlock. | |
395 | * | |
396 | * But until all the XFS lowlevel code is revamped to | |
397 | * handle buffer allocation failures we can't do much. | |
398 | */ | |
399 | if (!(++retries % 100)) | |
400 | printk(KERN_ERR | |
401 | "XFS: possible memory allocation " | |
402 | "deadlock in %s (mode:0x%x)\n", | |
34a622b2 | 403 | __func__, gfp_mask); |
1da177e4 | 404 | |
ce8e922c | 405 | XFS_STATS_INC(xb_page_retries); |
23ea4032 | 406 | xfsbufd_wakeup(0, gfp_mask); |
3fcfab16 | 407 | congestion_wait(WRITE, HZ/50); |
1da177e4 LT |
408 | goto retry; |
409 | } | |
410 | ||
ce8e922c | 411 | XFS_STATS_INC(xb_page_found); |
1da177e4 LT |
412 | |
413 | nbytes = min_t(size_t, size, PAGE_CACHE_SIZE - offset); | |
414 | size -= nbytes; | |
415 | ||
948ecdb4 | 416 | ASSERT(!PagePrivate(page)); |
1da177e4 LT |
417 | if (!PageUptodate(page)) { |
418 | page_count--; | |
a9759f2d | 419 | if (blocksize < PAGE_CACHE_SIZE && !PagePrivate(page)) { |
1da177e4 LT |
420 | if (test_page_region(page, offset, nbytes)) |
421 | page_count++; | |
422 | } | |
423 | } | |
424 | ||
a9759f2d | 425 | unlock_page(page); |
ce8e922c | 426 | bp->b_pages[i] = page; |
1da177e4 LT |
427 | offset = 0; |
428 | } | |
429 | ||
ce8e922c NS |
430 | if (page_count == bp->b_page_count) |
431 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 432 | |
ce8e922c | 433 | XB_TRACE(bp, "lookup_pages", (long)page_count); |
1da177e4 LT |
434 | return error; |
435 | } | |
436 | ||
437 | /* | |
438 | * Map buffer into kernel address-space if nessecary. | |
439 | */ | |
440 | STATIC int | |
ce8e922c | 441 | _xfs_buf_map_pages( |
1da177e4 LT |
442 | xfs_buf_t *bp, |
443 | uint flags) | |
444 | { | |
445 | /* A single page buffer is always mappable */ | |
ce8e922c NS |
446 | if (bp->b_page_count == 1) { |
447 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; | |
448 | bp->b_flags |= XBF_MAPPED; | |
449 | } else if (flags & XBF_MAPPED) { | |
1da177e4 LT |
450 | if (as_list_len > 64) |
451 | purge_addresses(); | |
ce8e922c NS |
452 | bp->b_addr = vmap(bp->b_pages, bp->b_page_count, |
453 | VM_MAP, PAGE_KERNEL); | |
454 | if (unlikely(bp->b_addr == NULL)) | |
1da177e4 | 455 | return -ENOMEM; |
ce8e922c NS |
456 | bp->b_addr += bp->b_offset; |
457 | bp->b_flags |= XBF_MAPPED; | |
1da177e4 LT |
458 | } |
459 | ||
460 | return 0; | |
461 | } | |
462 | ||
463 | /* | |
464 | * Finding and Reading Buffers | |
465 | */ | |
466 | ||
467 | /* | |
ce8e922c | 468 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 LT |
469 | * a given range of an inode. The buffer is returned |
470 | * locked. If other overlapping buffers exist, they are | |
471 | * released before the new buffer is created and locked, | |
472 | * which may imply that this call will block until those buffers | |
473 | * are unlocked. No I/O is implied by this call. | |
474 | */ | |
475 | xfs_buf_t * | |
ce8e922c | 476 | _xfs_buf_find( |
1da177e4 | 477 | xfs_buftarg_t *btp, /* block device target */ |
204ab25f | 478 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 479 | size_t isize, /* length of range */ |
ce8e922c NS |
480 | xfs_buf_flags_t flags, |
481 | xfs_buf_t *new_bp) | |
1da177e4 | 482 | { |
204ab25f | 483 | xfs_off_t range_base; |
1da177e4 LT |
484 | size_t range_length; |
485 | xfs_bufhash_t *hash; | |
ce8e922c | 486 | xfs_buf_t *bp, *n; |
1da177e4 LT |
487 | |
488 | range_base = (ioff << BBSHIFT); | |
489 | range_length = (isize << BBSHIFT); | |
490 | ||
491 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
ce8e922c | 492 | ASSERT(!(range_length < (1 << btp->bt_sshift))); |
204ab25f | 493 | ASSERT(!(range_base & (xfs_off_t)btp->bt_smask)); |
1da177e4 LT |
494 | |
495 | hash = &btp->bt_hash[hash_long((unsigned long)ioff, btp->bt_hashshift)]; | |
496 | ||
497 | spin_lock(&hash->bh_lock); | |
498 | ||
ce8e922c NS |
499 | list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) { |
500 | ASSERT(btp == bp->b_target); | |
501 | if (bp->b_file_offset == range_base && | |
502 | bp->b_buffer_length == range_length) { | |
1da177e4 | 503 | /* |
ce8e922c | 504 | * If we look at something, bring it to the |
1da177e4 LT |
505 | * front of the list for next time. |
506 | */ | |
ce8e922c NS |
507 | atomic_inc(&bp->b_hold); |
508 | list_move(&bp->b_hash_list, &hash->bh_list); | |
1da177e4 LT |
509 | goto found; |
510 | } | |
511 | } | |
512 | ||
513 | /* No match found */ | |
ce8e922c NS |
514 | if (new_bp) { |
515 | _xfs_buf_initialize(new_bp, btp, range_base, | |
1da177e4 | 516 | range_length, flags); |
ce8e922c NS |
517 | new_bp->b_hash = hash; |
518 | list_add(&new_bp->b_hash_list, &hash->bh_list); | |
1da177e4 | 519 | } else { |
ce8e922c | 520 | XFS_STATS_INC(xb_miss_locked); |
1da177e4 LT |
521 | } |
522 | ||
523 | spin_unlock(&hash->bh_lock); | |
ce8e922c | 524 | return new_bp; |
1da177e4 LT |
525 | |
526 | found: | |
527 | spin_unlock(&hash->bh_lock); | |
528 | ||
529 | /* Attempt to get the semaphore without sleeping, | |
530 | * if this does not work then we need to drop the | |
531 | * spinlock and do a hard attempt on the semaphore. | |
532 | */ | |
ce8e922c NS |
533 | if (down_trylock(&bp->b_sema)) { |
534 | if (!(flags & XBF_TRYLOCK)) { | |
1da177e4 | 535 | /* wait for buffer ownership */ |
ce8e922c NS |
536 | XB_TRACE(bp, "get_lock", 0); |
537 | xfs_buf_lock(bp); | |
538 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 LT |
539 | } else { |
540 | /* We asked for a trylock and failed, no need | |
541 | * to look at file offset and length here, we | |
ce8e922c NS |
542 | * know that this buffer at least overlaps our |
543 | * buffer and is locked, therefore our buffer | |
544 | * either does not exist, or is this buffer. | |
1da177e4 | 545 | */ |
ce8e922c NS |
546 | xfs_buf_rele(bp); |
547 | XFS_STATS_INC(xb_busy_locked); | |
548 | return NULL; | |
1da177e4 LT |
549 | } |
550 | } else { | |
551 | /* trylock worked */ | |
ce8e922c | 552 | XB_SET_OWNER(bp); |
1da177e4 LT |
553 | } |
554 | ||
ce8e922c NS |
555 | if (bp->b_flags & XBF_STALE) { |
556 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
557 | bp->b_flags &= XBF_MAPPED; | |
2f926587 | 558 | } |
ce8e922c NS |
559 | XB_TRACE(bp, "got_lock", 0); |
560 | XFS_STATS_INC(xb_get_locked); | |
561 | return bp; | |
1da177e4 LT |
562 | } |
563 | ||
564 | /* | |
ce8e922c | 565 | * Assembles a buffer covering the specified range. |
1da177e4 LT |
566 | * Storage in memory for all portions of the buffer will be allocated, |
567 | * although backing storage may not be. | |
568 | */ | |
569 | xfs_buf_t * | |
ce8e922c | 570 | xfs_buf_get_flags( |
1da177e4 | 571 | xfs_buftarg_t *target,/* target for buffer */ |
204ab25f | 572 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 573 | size_t isize, /* length of range */ |
ce8e922c | 574 | xfs_buf_flags_t flags) |
1da177e4 | 575 | { |
ce8e922c | 576 | xfs_buf_t *bp, *new_bp; |
1da177e4 LT |
577 | int error = 0, i; |
578 | ||
ce8e922c NS |
579 | new_bp = xfs_buf_allocate(flags); |
580 | if (unlikely(!new_bp)) | |
1da177e4 LT |
581 | return NULL; |
582 | ||
ce8e922c NS |
583 | bp = _xfs_buf_find(target, ioff, isize, flags, new_bp); |
584 | if (bp == new_bp) { | |
585 | error = _xfs_buf_lookup_pages(bp, flags); | |
1da177e4 LT |
586 | if (error) |
587 | goto no_buffer; | |
588 | } else { | |
ce8e922c NS |
589 | xfs_buf_deallocate(new_bp); |
590 | if (unlikely(bp == NULL)) | |
1da177e4 LT |
591 | return NULL; |
592 | } | |
593 | ||
ce8e922c NS |
594 | for (i = 0; i < bp->b_page_count; i++) |
595 | mark_page_accessed(bp->b_pages[i]); | |
1da177e4 | 596 | |
ce8e922c NS |
597 | if (!(bp->b_flags & XBF_MAPPED)) { |
598 | error = _xfs_buf_map_pages(bp, flags); | |
1da177e4 LT |
599 | if (unlikely(error)) { |
600 | printk(KERN_WARNING "%s: failed to map pages\n", | |
34a622b2 | 601 | __func__); |
1da177e4 LT |
602 | goto no_buffer; |
603 | } | |
604 | } | |
605 | ||
ce8e922c | 606 | XFS_STATS_INC(xb_get); |
1da177e4 LT |
607 | |
608 | /* | |
609 | * Always fill in the block number now, the mapped cases can do | |
610 | * their own overlay of this later. | |
611 | */ | |
ce8e922c NS |
612 | bp->b_bn = ioff; |
613 | bp->b_count_desired = bp->b_buffer_length; | |
1da177e4 | 614 | |
ce8e922c NS |
615 | XB_TRACE(bp, "get", (unsigned long)flags); |
616 | return bp; | |
1da177e4 LT |
617 | |
618 | no_buffer: | |
ce8e922c NS |
619 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
620 | xfs_buf_unlock(bp); | |
621 | xfs_buf_rele(bp); | |
1da177e4 LT |
622 | return NULL; |
623 | } | |
624 | ||
625 | xfs_buf_t * | |
626 | xfs_buf_read_flags( | |
627 | xfs_buftarg_t *target, | |
204ab25f | 628 | xfs_off_t ioff, |
1da177e4 | 629 | size_t isize, |
ce8e922c | 630 | xfs_buf_flags_t flags) |
1da177e4 | 631 | { |
ce8e922c NS |
632 | xfs_buf_t *bp; |
633 | ||
634 | flags |= XBF_READ; | |
635 | ||
636 | bp = xfs_buf_get_flags(target, ioff, isize, flags); | |
637 | if (bp) { | |
638 | if (!XFS_BUF_ISDONE(bp)) { | |
639 | XB_TRACE(bp, "read", (unsigned long)flags); | |
640 | XFS_STATS_INC(xb_get_read); | |
641 | xfs_buf_iostart(bp, flags); | |
642 | } else if (flags & XBF_ASYNC) { | |
643 | XB_TRACE(bp, "read_async", (unsigned long)flags); | |
1da177e4 LT |
644 | /* |
645 | * Read ahead call which is already satisfied, | |
646 | * drop the buffer | |
647 | */ | |
648 | goto no_buffer; | |
649 | } else { | |
ce8e922c | 650 | XB_TRACE(bp, "read_done", (unsigned long)flags); |
1da177e4 | 651 | /* We do not want read in the flags */ |
ce8e922c | 652 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
653 | } |
654 | } | |
655 | ||
ce8e922c | 656 | return bp; |
1da177e4 LT |
657 | |
658 | no_buffer: | |
ce8e922c NS |
659 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
660 | xfs_buf_unlock(bp); | |
661 | xfs_buf_rele(bp); | |
1da177e4 LT |
662 | return NULL; |
663 | } | |
664 | ||
1da177e4 | 665 | /* |
ce8e922c NS |
666 | * If we are not low on memory then do the readahead in a deadlock |
667 | * safe manner. | |
1da177e4 LT |
668 | */ |
669 | void | |
ce8e922c | 670 | xfs_buf_readahead( |
1da177e4 | 671 | xfs_buftarg_t *target, |
204ab25f | 672 | xfs_off_t ioff, |
1da177e4 | 673 | size_t isize, |
ce8e922c | 674 | xfs_buf_flags_t flags) |
1da177e4 LT |
675 | { |
676 | struct backing_dev_info *bdi; | |
677 | ||
ce8e922c | 678 | bdi = target->bt_mapping->backing_dev_info; |
1da177e4 LT |
679 | if (bdi_read_congested(bdi)) |
680 | return; | |
681 | ||
ce8e922c | 682 | flags |= (XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD); |
1da177e4 LT |
683 | xfs_buf_read_flags(target, ioff, isize, flags); |
684 | } | |
685 | ||
686 | xfs_buf_t * | |
ce8e922c | 687 | xfs_buf_get_empty( |
1da177e4 LT |
688 | size_t len, |
689 | xfs_buftarg_t *target) | |
690 | { | |
ce8e922c | 691 | xfs_buf_t *bp; |
1da177e4 | 692 | |
ce8e922c NS |
693 | bp = xfs_buf_allocate(0); |
694 | if (bp) | |
695 | _xfs_buf_initialize(bp, target, 0, len, 0); | |
696 | return bp; | |
1da177e4 LT |
697 | } |
698 | ||
699 | static inline struct page * | |
700 | mem_to_page( | |
701 | void *addr) | |
702 | { | |
9e2779fa | 703 | if ((!is_vmalloc_addr(addr))) { |
1da177e4 LT |
704 | return virt_to_page(addr); |
705 | } else { | |
706 | return vmalloc_to_page(addr); | |
707 | } | |
708 | } | |
709 | ||
710 | int | |
ce8e922c NS |
711 | xfs_buf_associate_memory( |
712 | xfs_buf_t *bp, | |
1da177e4 LT |
713 | void *mem, |
714 | size_t len) | |
715 | { | |
716 | int rval; | |
717 | int i = 0; | |
d1afb678 LM |
718 | unsigned long pageaddr; |
719 | unsigned long offset; | |
720 | size_t buflen; | |
1da177e4 LT |
721 | int page_count; |
722 | ||
d1afb678 LM |
723 | pageaddr = (unsigned long)mem & PAGE_CACHE_MASK; |
724 | offset = (unsigned long)mem - pageaddr; | |
725 | buflen = PAGE_CACHE_ALIGN(len + offset); | |
726 | page_count = buflen >> PAGE_CACHE_SHIFT; | |
1da177e4 LT |
727 | |
728 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
729 | if (bp->b_pages) |
730 | _xfs_buf_free_pages(bp); | |
1da177e4 | 731 | |
ce8e922c NS |
732 | bp->b_pages = NULL; |
733 | bp->b_addr = mem; | |
1da177e4 | 734 | |
ce8e922c | 735 | rval = _xfs_buf_get_pages(bp, page_count, 0); |
1da177e4 LT |
736 | if (rval) |
737 | return rval; | |
738 | ||
ce8e922c | 739 | bp->b_offset = offset; |
d1afb678 LM |
740 | |
741 | for (i = 0; i < bp->b_page_count; i++) { | |
742 | bp->b_pages[i] = mem_to_page((void *)pageaddr); | |
743 | pageaddr += PAGE_CACHE_SIZE; | |
1da177e4 | 744 | } |
1da177e4 | 745 | |
d1afb678 LM |
746 | bp->b_count_desired = len; |
747 | bp->b_buffer_length = buflen; | |
ce8e922c | 748 | bp->b_flags |= XBF_MAPPED; |
1da177e4 LT |
749 | |
750 | return 0; | |
751 | } | |
752 | ||
753 | xfs_buf_t * | |
ce8e922c | 754 | xfs_buf_get_noaddr( |
1da177e4 LT |
755 | size_t len, |
756 | xfs_buftarg_t *target) | |
757 | { | |
1fa40b01 CH |
758 | unsigned long page_count = PAGE_ALIGN(len) >> PAGE_SHIFT; |
759 | int error, i; | |
1da177e4 | 760 | xfs_buf_t *bp; |
1da177e4 | 761 | |
ce8e922c | 762 | bp = xfs_buf_allocate(0); |
1da177e4 LT |
763 | if (unlikely(bp == NULL)) |
764 | goto fail; | |
ce8e922c | 765 | _xfs_buf_initialize(bp, target, 0, len, 0); |
1da177e4 | 766 | |
1fa40b01 CH |
767 | error = _xfs_buf_get_pages(bp, page_count, 0); |
768 | if (error) | |
1da177e4 LT |
769 | goto fail_free_buf; |
770 | ||
1fa40b01 CH |
771 | for (i = 0; i < page_count; i++) { |
772 | bp->b_pages[i] = alloc_page(GFP_KERNEL); | |
773 | if (!bp->b_pages[i]) | |
774 | goto fail_free_mem; | |
1da177e4 | 775 | } |
1fa40b01 | 776 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 777 | |
1fa40b01 CH |
778 | error = _xfs_buf_map_pages(bp, XBF_MAPPED); |
779 | if (unlikely(error)) { | |
780 | printk(KERN_WARNING "%s: failed to map pages\n", | |
34a622b2 | 781 | __func__); |
1da177e4 | 782 | goto fail_free_mem; |
1fa40b01 | 783 | } |
1da177e4 | 784 | |
ce8e922c | 785 | xfs_buf_unlock(bp); |
1da177e4 | 786 | |
1fa40b01 | 787 | XB_TRACE(bp, "no_daddr", len); |
1da177e4 | 788 | return bp; |
1fa40b01 | 789 | |
1da177e4 | 790 | fail_free_mem: |
1fa40b01 CH |
791 | while (--i >= 0) |
792 | __free_page(bp->b_pages[i]); | |
ca165b88 | 793 | _xfs_buf_free_pages(bp); |
1da177e4 | 794 | fail_free_buf: |
ca165b88 | 795 | xfs_buf_deallocate(bp); |
1da177e4 LT |
796 | fail: |
797 | return NULL; | |
798 | } | |
799 | ||
800 | /* | |
1da177e4 LT |
801 | * Increment reference count on buffer, to hold the buffer concurrently |
802 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
803 | * Must hold the buffer already to call this function. |
804 | */ | |
805 | void | |
ce8e922c NS |
806 | xfs_buf_hold( |
807 | xfs_buf_t *bp) | |
1da177e4 | 808 | { |
ce8e922c NS |
809 | atomic_inc(&bp->b_hold); |
810 | XB_TRACE(bp, "hold", 0); | |
1da177e4 LT |
811 | } |
812 | ||
813 | /* | |
ce8e922c NS |
814 | * Releases a hold on the specified buffer. If the |
815 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
816 | */ |
817 | void | |
ce8e922c NS |
818 | xfs_buf_rele( |
819 | xfs_buf_t *bp) | |
1da177e4 | 820 | { |
ce8e922c | 821 | xfs_bufhash_t *hash = bp->b_hash; |
1da177e4 | 822 | |
ce8e922c | 823 | XB_TRACE(bp, "rele", bp->b_relse); |
1da177e4 | 824 | |
fad3aa1e NS |
825 | if (unlikely(!hash)) { |
826 | ASSERT(!bp->b_relse); | |
827 | if (atomic_dec_and_test(&bp->b_hold)) | |
828 | xfs_buf_free(bp); | |
829 | return; | |
830 | } | |
831 | ||
ce8e922c NS |
832 | if (atomic_dec_and_lock(&bp->b_hold, &hash->bh_lock)) { |
833 | if (bp->b_relse) { | |
834 | atomic_inc(&bp->b_hold); | |
1da177e4 | 835 | spin_unlock(&hash->bh_lock); |
ce8e922c NS |
836 | (*(bp->b_relse)) (bp); |
837 | } else if (bp->b_flags & XBF_FS_MANAGED) { | |
1da177e4 | 838 | spin_unlock(&hash->bh_lock); |
1da177e4 | 839 | } else { |
ce8e922c NS |
840 | ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q))); |
841 | list_del_init(&bp->b_hash_list); | |
1da177e4 | 842 | spin_unlock(&hash->bh_lock); |
ce8e922c | 843 | xfs_buf_free(bp); |
1da177e4 | 844 | } |
2f926587 DC |
845 | } else { |
846 | /* | |
847 | * Catch reference count leaks | |
848 | */ | |
ce8e922c | 849 | ASSERT(atomic_read(&bp->b_hold) >= 0); |
1da177e4 LT |
850 | } |
851 | } | |
852 | ||
853 | ||
854 | /* | |
855 | * Mutual exclusion on buffers. Locking model: | |
856 | * | |
857 | * Buffers associated with inodes for which buffer locking | |
858 | * is not enabled are not protected by semaphores, and are | |
859 | * assumed to be exclusively owned by the caller. There is a | |
860 | * spinlock in the buffer, used by the caller when concurrent | |
861 | * access is possible. | |
862 | */ | |
863 | ||
864 | /* | |
ce8e922c NS |
865 | * Locks a buffer object, if it is not already locked. |
866 | * Note that this in no way locks the underlying pages, so it is only | |
867 | * useful for synchronizing concurrent use of buffer objects, not for | |
868 | * synchronizing independent access to the underlying pages. | |
1da177e4 LT |
869 | */ |
870 | int | |
ce8e922c NS |
871 | xfs_buf_cond_lock( |
872 | xfs_buf_t *bp) | |
1da177e4 LT |
873 | { |
874 | int locked; | |
875 | ||
ce8e922c | 876 | locked = down_trylock(&bp->b_sema) == 0; |
1da177e4 | 877 | if (locked) { |
ce8e922c | 878 | XB_SET_OWNER(bp); |
1da177e4 | 879 | } |
ce8e922c NS |
880 | XB_TRACE(bp, "cond_lock", (long)locked); |
881 | return locked ? 0 : -EBUSY; | |
1da177e4 LT |
882 | } |
883 | ||
884 | #if defined(DEBUG) || defined(XFS_BLI_TRACE) | |
1da177e4 | 885 | int |
ce8e922c NS |
886 | xfs_buf_lock_value( |
887 | xfs_buf_t *bp) | |
1da177e4 | 888 | { |
adaa693b | 889 | return bp->b_sema.count; |
1da177e4 LT |
890 | } |
891 | #endif | |
892 | ||
893 | /* | |
ce8e922c NS |
894 | * Locks a buffer object. |
895 | * Note that this in no way locks the underlying pages, so it is only | |
896 | * useful for synchronizing concurrent use of buffer objects, not for | |
897 | * synchronizing independent access to the underlying pages. | |
1da177e4 | 898 | */ |
ce8e922c NS |
899 | void |
900 | xfs_buf_lock( | |
901 | xfs_buf_t *bp) | |
1da177e4 | 902 | { |
ce8e922c NS |
903 | XB_TRACE(bp, "lock", 0); |
904 | if (atomic_read(&bp->b_io_remaining)) | |
905 | blk_run_address_space(bp->b_target->bt_mapping); | |
906 | down(&bp->b_sema); | |
907 | XB_SET_OWNER(bp); | |
908 | XB_TRACE(bp, "locked", 0); | |
1da177e4 LT |
909 | } |
910 | ||
911 | /* | |
ce8e922c | 912 | * Releases the lock on the buffer object. |
2f926587 | 913 | * If the buffer is marked delwri but is not queued, do so before we |
ce8e922c | 914 | * unlock the buffer as we need to set flags correctly. We also need to |
2f926587 DC |
915 | * take a reference for the delwri queue because the unlocker is going to |
916 | * drop their's and they don't know we just queued it. | |
1da177e4 LT |
917 | */ |
918 | void | |
ce8e922c NS |
919 | xfs_buf_unlock( |
920 | xfs_buf_t *bp) | |
1da177e4 | 921 | { |
ce8e922c NS |
922 | if ((bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)) == XBF_DELWRI) { |
923 | atomic_inc(&bp->b_hold); | |
924 | bp->b_flags |= XBF_ASYNC; | |
925 | xfs_buf_delwri_queue(bp, 0); | |
2f926587 DC |
926 | } |
927 | ||
ce8e922c NS |
928 | XB_CLEAR_OWNER(bp); |
929 | up(&bp->b_sema); | |
930 | XB_TRACE(bp, "unlock", 0); | |
1da177e4 LT |
931 | } |
932 | ||
933 | ||
934 | /* | |
935 | * Pinning Buffer Storage in Memory | |
ce8e922c | 936 | * Ensure that no attempt to force a buffer to disk will succeed. |
1da177e4 LT |
937 | */ |
938 | void | |
ce8e922c NS |
939 | xfs_buf_pin( |
940 | xfs_buf_t *bp) | |
1da177e4 | 941 | { |
ce8e922c NS |
942 | atomic_inc(&bp->b_pin_count); |
943 | XB_TRACE(bp, "pin", (long)bp->b_pin_count.counter); | |
1da177e4 LT |
944 | } |
945 | ||
1da177e4 | 946 | void |
ce8e922c NS |
947 | xfs_buf_unpin( |
948 | xfs_buf_t *bp) | |
1da177e4 | 949 | { |
ce8e922c NS |
950 | if (atomic_dec_and_test(&bp->b_pin_count)) |
951 | wake_up_all(&bp->b_waiters); | |
952 | XB_TRACE(bp, "unpin", (long)bp->b_pin_count.counter); | |
1da177e4 LT |
953 | } |
954 | ||
955 | int | |
ce8e922c NS |
956 | xfs_buf_ispin( |
957 | xfs_buf_t *bp) | |
1da177e4 | 958 | { |
ce8e922c | 959 | return atomic_read(&bp->b_pin_count); |
1da177e4 LT |
960 | } |
961 | ||
ce8e922c NS |
962 | STATIC void |
963 | xfs_buf_wait_unpin( | |
964 | xfs_buf_t *bp) | |
1da177e4 LT |
965 | { |
966 | DECLARE_WAITQUEUE (wait, current); | |
967 | ||
ce8e922c | 968 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
969 | return; |
970 | ||
ce8e922c | 971 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
972 | for (;;) { |
973 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 974 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 975 | break; |
ce8e922c NS |
976 | if (atomic_read(&bp->b_io_remaining)) |
977 | blk_run_address_space(bp->b_target->bt_mapping); | |
1da177e4 LT |
978 | schedule(); |
979 | } | |
ce8e922c | 980 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
981 | set_current_state(TASK_RUNNING); |
982 | } | |
983 | ||
984 | /* | |
985 | * Buffer Utility Routines | |
986 | */ | |
987 | ||
1da177e4 | 988 | STATIC void |
ce8e922c | 989 | xfs_buf_iodone_work( |
c4028958 | 990 | struct work_struct *work) |
1da177e4 | 991 | { |
c4028958 DH |
992 | xfs_buf_t *bp = |
993 | container_of(work, xfs_buf_t, b_iodone_work); | |
1da177e4 | 994 | |
0bfefc46 DC |
995 | /* |
996 | * We can get an EOPNOTSUPP to ordered writes. Here we clear the | |
997 | * ordered flag and reissue them. Because we can't tell the higher | |
998 | * layers directly that they should not issue ordered I/O anymore, they | |
999 | * need to check if the ordered flag was cleared during I/O completion. | |
1000 | */ | |
1001 | if ((bp->b_error == EOPNOTSUPP) && | |
1002 | (bp->b_flags & (XBF_ORDERED|XBF_ASYNC)) == (XBF_ORDERED|XBF_ASYNC)) { | |
1003 | XB_TRACE(bp, "ordered_retry", bp->b_iodone); | |
1004 | bp->b_flags &= ~XBF_ORDERED; | |
1005 | xfs_buf_iorequest(bp); | |
1006 | } else if (bp->b_iodone) | |
ce8e922c NS |
1007 | (*(bp->b_iodone))(bp); |
1008 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 LT |
1009 | xfs_buf_relse(bp); |
1010 | } | |
1011 | ||
1012 | void | |
ce8e922c NS |
1013 | xfs_buf_ioend( |
1014 | xfs_buf_t *bp, | |
1da177e4 LT |
1015 | int schedule) |
1016 | { | |
77be55a5 | 1017 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); |
ce8e922c NS |
1018 | if (bp->b_error == 0) |
1019 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1020 | |
ce8e922c | 1021 | XB_TRACE(bp, "iodone", bp->b_iodone); |
1da177e4 | 1022 | |
ce8e922c | 1023 | if ((bp->b_iodone) || (bp->b_flags & XBF_ASYNC)) { |
1da177e4 | 1024 | if (schedule) { |
c4028958 | 1025 | INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work); |
ce8e922c | 1026 | queue_work(xfslogd_workqueue, &bp->b_iodone_work); |
1da177e4 | 1027 | } else { |
c4028958 | 1028 | xfs_buf_iodone_work(&bp->b_iodone_work); |
1da177e4 LT |
1029 | } |
1030 | } else { | |
ce8e922c | 1031 | up(&bp->b_iodonesema); |
1da177e4 LT |
1032 | } |
1033 | } | |
1034 | ||
1da177e4 | 1035 | void |
ce8e922c NS |
1036 | xfs_buf_ioerror( |
1037 | xfs_buf_t *bp, | |
1038 | int error) | |
1da177e4 LT |
1039 | { |
1040 | ASSERT(error >= 0 && error <= 0xffff); | |
ce8e922c NS |
1041 | bp->b_error = (unsigned short)error; |
1042 | XB_TRACE(bp, "ioerror", (unsigned long)error); | |
1da177e4 LT |
1043 | } |
1044 | ||
1045 | /* | |
ce8e922c NS |
1046 | * Initiate I/O on a buffer, based on the flags supplied. |
1047 | * The b_iodone routine in the buffer supplied will only be called | |
1da177e4 | 1048 | * when all of the subsidiary I/O requests, if any, have been completed. |
1da177e4 LT |
1049 | */ |
1050 | int | |
ce8e922c NS |
1051 | xfs_buf_iostart( |
1052 | xfs_buf_t *bp, | |
1053 | xfs_buf_flags_t flags) | |
1da177e4 LT |
1054 | { |
1055 | int status = 0; | |
1056 | ||
ce8e922c | 1057 | XB_TRACE(bp, "iostart", (unsigned long)flags); |
1da177e4 | 1058 | |
ce8e922c NS |
1059 | if (flags & XBF_DELWRI) { |
1060 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_ASYNC); | |
1061 | bp->b_flags |= flags & (XBF_DELWRI | XBF_ASYNC); | |
1062 | xfs_buf_delwri_queue(bp, 1); | |
958d4ec6 | 1063 | return 0; |
1da177e4 LT |
1064 | } |
1065 | ||
ce8e922c NS |
1066 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_ASYNC | XBF_DELWRI | \ |
1067 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
1068 | bp->b_flags |= flags & (XBF_READ | XBF_WRITE | XBF_ASYNC | \ | |
1069 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
1da177e4 | 1070 | |
ce8e922c | 1071 | BUG_ON(bp->b_bn == XFS_BUF_DADDR_NULL); |
1da177e4 LT |
1072 | |
1073 | /* For writes allow an alternate strategy routine to precede | |
1074 | * the actual I/O request (which may not be issued at all in | |
1075 | * a shutdown situation, for example). | |
1076 | */ | |
ce8e922c NS |
1077 | status = (flags & XBF_WRITE) ? |
1078 | xfs_buf_iostrategy(bp) : xfs_buf_iorequest(bp); | |
1da177e4 LT |
1079 | |
1080 | /* Wait for I/O if we are not an async request. | |
1081 | * Note: async I/O request completion will release the buffer, | |
1082 | * and that can already be done by this point. So using the | |
1083 | * buffer pointer from here on, after async I/O, is invalid. | |
1084 | */ | |
ce8e922c NS |
1085 | if (!status && !(flags & XBF_ASYNC)) |
1086 | status = xfs_buf_iowait(bp); | |
1da177e4 LT |
1087 | |
1088 | return status; | |
1089 | } | |
1090 | ||
7989cb8e | 1091 | STATIC_INLINE void |
ce8e922c NS |
1092 | _xfs_buf_ioend( |
1093 | xfs_buf_t *bp, | |
1da177e4 LT |
1094 | int schedule) |
1095 | { | |
a9759f2d | 1096 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) |
ce8e922c | 1097 | xfs_buf_ioend(bp, schedule); |
1da177e4 LT |
1098 | } |
1099 | ||
782e3b3b | 1100 | STATIC void |
ce8e922c | 1101 | xfs_buf_bio_end_io( |
1da177e4 | 1102 | struct bio *bio, |
1da177e4 LT |
1103 | int error) |
1104 | { | |
ce8e922c NS |
1105 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1106 | unsigned int blocksize = bp->b_target->bt_bsize; | |
eedb5530 | 1107 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; |
1da177e4 | 1108 | |
1da177e4 | 1109 | if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) |
ce8e922c | 1110 | bp->b_error = EIO; |
1da177e4 | 1111 | |
eedb5530 | 1112 | do { |
1da177e4 LT |
1113 | struct page *page = bvec->bv_page; |
1114 | ||
948ecdb4 | 1115 | ASSERT(!PagePrivate(page)); |
ce8e922c NS |
1116 | if (unlikely(bp->b_error)) { |
1117 | if (bp->b_flags & XBF_READ) | |
eedb5530 | 1118 | ClearPageUptodate(page); |
ce8e922c | 1119 | } else if (blocksize >= PAGE_CACHE_SIZE) { |
1da177e4 LT |
1120 | SetPageUptodate(page); |
1121 | } else if (!PagePrivate(page) && | |
ce8e922c | 1122 | (bp->b_flags & _XBF_PAGE_CACHE)) { |
1da177e4 LT |
1123 | set_page_region(page, bvec->bv_offset, bvec->bv_len); |
1124 | } | |
1125 | ||
eedb5530 NS |
1126 | if (--bvec >= bio->bi_io_vec) |
1127 | prefetchw(&bvec->bv_page->flags); | |
eedb5530 | 1128 | } while (bvec >= bio->bi_io_vec); |
1da177e4 | 1129 | |
ce8e922c | 1130 | _xfs_buf_ioend(bp, 1); |
1da177e4 | 1131 | bio_put(bio); |
1da177e4 LT |
1132 | } |
1133 | ||
1134 | STATIC void | |
ce8e922c NS |
1135 | _xfs_buf_ioapply( |
1136 | xfs_buf_t *bp) | |
1da177e4 | 1137 | { |
a9759f2d | 1138 | int rw, map_i, total_nr_pages, nr_pages; |
1da177e4 | 1139 | struct bio *bio; |
ce8e922c NS |
1140 | int offset = bp->b_offset; |
1141 | int size = bp->b_count_desired; | |
1142 | sector_t sector = bp->b_bn; | |
1143 | unsigned int blocksize = bp->b_target->bt_bsize; | |
1da177e4 | 1144 | |
ce8e922c | 1145 | total_nr_pages = bp->b_page_count; |
1da177e4 LT |
1146 | map_i = 0; |
1147 | ||
ce8e922c NS |
1148 | if (bp->b_flags & XBF_ORDERED) { |
1149 | ASSERT(!(bp->b_flags & XBF_READ)); | |
f538d4da | 1150 | rw = WRITE_BARRIER; |
51bdd706 NS |
1151 | } else if (bp->b_flags & _XBF_RUN_QUEUES) { |
1152 | ASSERT(!(bp->b_flags & XBF_READ_AHEAD)); | |
1153 | bp->b_flags &= ~_XBF_RUN_QUEUES; | |
1154 | rw = (bp->b_flags & XBF_WRITE) ? WRITE_SYNC : READ_SYNC; | |
1155 | } else { | |
1156 | rw = (bp->b_flags & XBF_WRITE) ? WRITE : | |
1157 | (bp->b_flags & XBF_READ_AHEAD) ? READA : READ; | |
f538d4da CH |
1158 | } |
1159 | ||
ce8e922c | 1160 | /* Special code path for reading a sub page size buffer in -- |
1da177e4 LT |
1161 | * we populate up the whole page, and hence the other metadata |
1162 | * in the same page. This optimization is only valid when the | |
ce8e922c | 1163 | * filesystem block size is not smaller than the page size. |
1da177e4 | 1164 | */ |
ce8e922c | 1165 | if ((bp->b_buffer_length < PAGE_CACHE_SIZE) && |
a9759f2d | 1166 | (bp->b_flags & XBF_READ) && |
ce8e922c | 1167 | (blocksize >= PAGE_CACHE_SIZE)) { |
1da177e4 LT |
1168 | bio = bio_alloc(GFP_NOIO, 1); |
1169 | ||
ce8e922c | 1170 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1171 | bio->bi_sector = sector - (offset >> BBSHIFT); |
ce8e922c NS |
1172 | bio->bi_end_io = xfs_buf_bio_end_io; |
1173 | bio->bi_private = bp; | |
1da177e4 | 1174 | |
ce8e922c | 1175 | bio_add_page(bio, bp->b_pages[0], PAGE_CACHE_SIZE, 0); |
1da177e4 LT |
1176 | size = 0; |
1177 | ||
ce8e922c | 1178 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1179 | |
1180 | goto submit_io; | |
1181 | } | |
1182 | ||
1da177e4 | 1183 | next_chunk: |
ce8e922c | 1184 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1185 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1186 | if (nr_pages > total_nr_pages) | |
1187 | nr_pages = total_nr_pages; | |
1188 | ||
1189 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1190 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1191 | bio->bi_sector = sector; |
ce8e922c NS |
1192 | bio->bi_end_io = xfs_buf_bio_end_io; |
1193 | bio->bi_private = bp; | |
1da177e4 LT |
1194 | |
1195 | for (; size && nr_pages; nr_pages--, map_i++) { | |
ce8e922c | 1196 | int rbytes, nbytes = PAGE_CACHE_SIZE - offset; |
1da177e4 LT |
1197 | |
1198 | if (nbytes > size) | |
1199 | nbytes = size; | |
1200 | ||
ce8e922c NS |
1201 | rbytes = bio_add_page(bio, bp->b_pages[map_i], nbytes, offset); |
1202 | if (rbytes < nbytes) | |
1da177e4 LT |
1203 | break; |
1204 | ||
1205 | offset = 0; | |
1206 | sector += nbytes >> BBSHIFT; | |
1207 | size -= nbytes; | |
1208 | total_nr_pages--; | |
1209 | } | |
1210 | ||
1211 | submit_io: | |
1212 | if (likely(bio->bi_size)) { | |
1213 | submit_bio(rw, bio); | |
1214 | if (size) | |
1215 | goto next_chunk; | |
1216 | } else { | |
1217 | bio_put(bio); | |
ce8e922c | 1218 | xfs_buf_ioerror(bp, EIO); |
1da177e4 LT |
1219 | } |
1220 | } | |
1221 | ||
1da177e4 | 1222 | int |
ce8e922c NS |
1223 | xfs_buf_iorequest( |
1224 | xfs_buf_t *bp) | |
1da177e4 | 1225 | { |
ce8e922c | 1226 | XB_TRACE(bp, "iorequest", 0); |
1da177e4 | 1227 | |
ce8e922c NS |
1228 | if (bp->b_flags & XBF_DELWRI) { |
1229 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1230 | return 0; |
1231 | } | |
1232 | ||
ce8e922c NS |
1233 | if (bp->b_flags & XBF_WRITE) { |
1234 | xfs_buf_wait_unpin(bp); | |
1da177e4 LT |
1235 | } |
1236 | ||
ce8e922c | 1237 | xfs_buf_hold(bp); |
1da177e4 LT |
1238 | |
1239 | /* Set the count to 1 initially, this will stop an I/O | |
1240 | * completion callout which happens before we have started | |
ce8e922c | 1241 | * all the I/O from calling xfs_buf_ioend too early. |
1da177e4 | 1242 | */ |
ce8e922c NS |
1243 | atomic_set(&bp->b_io_remaining, 1); |
1244 | _xfs_buf_ioapply(bp); | |
1245 | _xfs_buf_ioend(bp, 0); | |
1da177e4 | 1246 | |
ce8e922c | 1247 | xfs_buf_rele(bp); |
1da177e4 LT |
1248 | return 0; |
1249 | } | |
1250 | ||
1251 | /* | |
ce8e922c NS |
1252 | * Waits for I/O to complete on the buffer supplied. |
1253 | * It returns immediately if no I/O is pending. | |
1254 | * It returns the I/O error code, if any, or 0 if there was no error. | |
1da177e4 LT |
1255 | */ |
1256 | int | |
ce8e922c NS |
1257 | xfs_buf_iowait( |
1258 | xfs_buf_t *bp) | |
1da177e4 | 1259 | { |
ce8e922c NS |
1260 | XB_TRACE(bp, "iowait", 0); |
1261 | if (atomic_read(&bp->b_io_remaining)) | |
1262 | blk_run_address_space(bp->b_target->bt_mapping); | |
1263 | down(&bp->b_iodonesema); | |
1264 | XB_TRACE(bp, "iowaited", (long)bp->b_error); | |
1265 | return bp->b_error; | |
1da177e4 LT |
1266 | } |
1267 | ||
ce8e922c NS |
1268 | xfs_caddr_t |
1269 | xfs_buf_offset( | |
1270 | xfs_buf_t *bp, | |
1da177e4 LT |
1271 | size_t offset) |
1272 | { | |
1273 | struct page *page; | |
1274 | ||
ce8e922c NS |
1275 | if (bp->b_flags & XBF_MAPPED) |
1276 | return XFS_BUF_PTR(bp) + offset; | |
1da177e4 | 1277 | |
ce8e922c NS |
1278 | offset += bp->b_offset; |
1279 | page = bp->b_pages[offset >> PAGE_CACHE_SHIFT]; | |
1280 | return (xfs_caddr_t)page_address(page) + (offset & (PAGE_CACHE_SIZE-1)); | |
1da177e4 LT |
1281 | } |
1282 | ||
1283 | /* | |
1da177e4 LT |
1284 | * Move data into or out of a buffer. |
1285 | */ | |
1286 | void | |
ce8e922c NS |
1287 | xfs_buf_iomove( |
1288 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1289 | size_t boff, /* starting buffer offset */ |
1290 | size_t bsize, /* length to copy */ | |
1291 | caddr_t data, /* data address */ | |
ce8e922c | 1292 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 LT |
1293 | { |
1294 | size_t bend, cpoff, csize; | |
1295 | struct page *page; | |
1296 | ||
1297 | bend = boff + bsize; | |
1298 | while (boff < bend) { | |
ce8e922c NS |
1299 | page = bp->b_pages[xfs_buf_btoct(boff + bp->b_offset)]; |
1300 | cpoff = xfs_buf_poff(boff + bp->b_offset); | |
1da177e4 | 1301 | csize = min_t(size_t, |
ce8e922c | 1302 | PAGE_CACHE_SIZE-cpoff, bp->b_count_desired-boff); |
1da177e4 LT |
1303 | |
1304 | ASSERT(((csize + cpoff) <= PAGE_CACHE_SIZE)); | |
1305 | ||
1306 | switch (mode) { | |
ce8e922c | 1307 | case XBRW_ZERO: |
1da177e4 LT |
1308 | memset(page_address(page) + cpoff, 0, csize); |
1309 | break; | |
ce8e922c | 1310 | case XBRW_READ: |
1da177e4 LT |
1311 | memcpy(data, page_address(page) + cpoff, csize); |
1312 | break; | |
ce8e922c | 1313 | case XBRW_WRITE: |
1da177e4 LT |
1314 | memcpy(page_address(page) + cpoff, data, csize); |
1315 | } | |
1316 | ||
1317 | boff += csize; | |
1318 | data += csize; | |
1319 | } | |
1320 | } | |
1321 | ||
1322 | /* | |
ce8e922c | 1323 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1324 | */ |
1325 | ||
1326 | /* | |
ce8e922c NS |
1327 | * Wait for any bufs with callbacks that have been submitted but |
1328 | * have not yet returned... walk the hash list for the target. | |
1da177e4 LT |
1329 | */ |
1330 | void | |
1331 | xfs_wait_buftarg( | |
1332 | xfs_buftarg_t *btp) | |
1333 | { | |
1334 | xfs_buf_t *bp, *n; | |
1335 | xfs_bufhash_t *hash; | |
1336 | uint i; | |
1337 | ||
1338 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { | |
1339 | hash = &btp->bt_hash[i]; | |
1340 | again: | |
1341 | spin_lock(&hash->bh_lock); | |
ce8e922c NS |
1342 | list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) { |
1343 | ASSERT(btp == bp->b_target); | |
1344 | if (!(bp->b_flags & XBF_FS_MANAGED)) { | |
1da177e4 | 1345 | spin_unlock(&hash->bh_lock); |
2f926587 DC |
1346 | /* |
1347 | * Catch superblock reference count leaks | |
1348 | * immediately | |
1349 | */ | |
ce8e922c | 1350 | BUG_ON(bp->b_bn == 0); |
1da177e4 LT |
1351 | delay(100); |
1352 | goto again; | |
1353 | } | |
1354 | } | |
1355 | spin_unlock(&hash->bh_lock); | |
1356 | } | |
1357 | } | |
1358 | ||
1359 | /* | |
ce8e922c NS |
1360 | * Allocate buffer hash table for a given target. |
1361 | * For devices containing metadata (i.e. not the log/realtime devices) | |
1362 | * we need to allocate a much larger hash table. | |
1da177e4 LT |
1363 | */ |
1364 | STATIC void | |
1365 | xfs_alloc_bufhash( | |
1366 | xfs_buftarg_t *btp, | |
1367 | int external) | |
1368 | { | |
1369 | unsigned int i; | |
1370 | ||
1371 | btp->bt_hashshift = external ? 3 : 8; /* 8 or 256 buckets */ | |
1372 | btp->bt_hashmask = (1 << btp->bt_hashshift) - 1; | |
1373 | btp->bt_hash = kmem_zalloc((1 << btp->bt_hashshift) * | |
93c189c1 | 1374 | sizeof(xfs_bufhash_t), KM_SLEEP | KM_LARGE); |
1da177e4 LT |
1375 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { |
1376 | spin_lock_init(&btp->bt_hash[i].bh_lock); | |
1377 | INIT_LIST_HEAD(&btp->bt_hash[i].bh_list); | |
1378 | } | |
1379 | } | |
1380 | ||
1381 | STATIC void | |
1382 | xfs_free_bufhash( | |
1383 | xfs_buftarg_t *btp) | |
1384 | { | |
ce8e922c | 1385 | kmem_free(btp->bt_hash, (1<<btp->bt_hashshift) * sizeof(xfs_bufhash_t)); |
1da177e4 LT |
1386 | btp->bt_hash = NULL; |
1387 | } | |
1388 | ||
a6867a68 | 1389 | /* |
ce8e922c | 1390 | * buftarg list for delwrite queue processing |
a6867a68 | 1391 | */ |
e6a0e9cd | 1392 | static LIST_HEAD(xfs_buftarg_list); |
7989cb8e | 1393 | static DEFINE_SPINLOCK(xfs_buftarg_lock); |
a6867a68 DC |
1394 | |
1395 | STATIC void | |
1396 | xfs_register_buftarg( | |
1397 | xfs_buftarg_t *btp) | |
1398 | { | |
1399 | spin_lock(&xfs_buftarg_lock); | |
1400 | list_add(&btp->bt_list, &xfs_buftarg_list); | |
1401 | spin_unlock(&xfs_buftarg_lock); | |
1402 | } | |
1403 | ||
1404 | STATIC void | |
1405 | xfs_unregister_buftarg( | |
1406 | xfs_buftarg_t *btp) | |
1407 | { | |
1408 | spin_lock(&xfs_buftarg_lock); | |
1409 | list_del(&btp->bt_list); | |
1410 | spin_unlock(&xfs_buftarg_lock); | |
1411 | } | |
1412 | ||
1da177e4 LT |
1413 | void |
1414 | xfs_free_buftarg( | |
1415 | xfs_buftarg_t *btp, | |
1416 | int external) | |
1417 | { | |
1418 | xfs_flush_buftarg(btp, 1); | |
f4a9f28a | 1419 | xfs_blkdev_issue_flush(btp); |
1da177e4 | 1420 | if (external) |
ce8e922c | 1421 | xfs_blkdev_put(btp->bt_bdev); |
1da177e4 | 1422 | xfs_free_bufhash(btp); |
ce8e922c | 1423 | iput(btp->bt_mapping->host); |
a6867a68 | 1424 | |
ce8e922c NS |
1425 | /* Unregister the buftarg first so that we don't get a |
1426 | * wakeup finding a non-existent task | |
1427 | */ | |
a6867a68 DC |
1428 | xfs_unregister_buftarg(btp); |
1429 | kthread_stop(btp->bt_task); | |
1430 | ||
1da177e4 LT |
1431 | kmem_free(btp, sizeof(*btp)); |
1432 | } | |
1433 | ||
1da177e4 LT |
1434 | STATIC int |
1435 | xfs_setsize_buftarg_flags( | |
1436 | xfs_buftarg_t *btp, | |
1437 | unsigned int blocksize, | |
1438 | unsigned int sectorsize, | |
1439 | int verbose) | |
1440 | { | |
ce8e922c NS |
1441 | btp->bt_bsize = blocksize; |
1442 | btp->bt_sshift = ffs(sectorsize) - 1; | |
1443 | btp->bt_smask = sectorsize - 1; | |
1da177e4 | 1444 | |
ce8e922c | 1445 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
1da177e4 LT |
1446 | printk(KERN_WARNING |
1447 | "XFS: Cannot set_blocksize to %u on device %s\n", | |
1448 | sectorsize, XFS_BUFTARG_NAME(btp)); | |
1449 | return EINVAL; | |
1450 | } | |
1451 | ||
1452 | if (verbose && | |
1453 | (PAGE_CACHE_SIZE / BITS_PER_LONG) > sectorsize) { | |
1454 | printk(KERN_WARNING | |
1455 | "XFS: %u byte sectors in use on device %s. " | |
1456 | "This is suboptimal; %u or greater is ideal.\n", | |
1457 | sectorsize, XFS_BUFTARG_NAME(btp), | |
1458 | (unsigned int)PAGE_CACHE_SIZE / BITS_PER_LONG); | |
1459 | } | |
1460 | ||
1461 | return 0; | |
1462 | } | |
1463 | ||
1464 | /* | |
ce8e922c NS |
1465 | * When allocating the initial buffer target we have not yet |
1466 | * read in the superblock, so don't know what sized sectors | |
1467 | * are being used is at this early stage. Play safe. | |
1468 | */ | |
1da177e4 LT |
1469 | STATIC int |
1470 | xfs_setsize_buftarg_early( | |
1471 | xfs_buftarg_t *btp, | |
1472 | struct block_device *bdev) | |
1473 | { | |
1474 | return xfs_setsize_buftarg_flags(btp, | |
1475 | PAGE_CACHE_SIZE, bdev_hardsect_size(bdev), 0); | |
1476 | } | |
1477 | ||
1478 | int | |
1479 | xfs_setsize_buftarg( | |
1480 | xfs_buftarg_t *btp, | |
1481 | unsigned int blocksize, | |
1482 | unsigned int sectorsize) | |
1483 | { | |
1484 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | |
1485 | } | |
1486 | ||
1487 | STATIC int | |
1488 | xfs_mapping_buftarg( | |
1489 | xfs_buftarg_t *btp, | |
1490 | struct block_device *bdev) | |
1491 | { | |
1492 | struct backing_dev_info *bdi; | |
1493 | struct inode *inode; | |
1494 | struct address_space *mapping; | |
f5e54d6e | 1495 | static const struct address_space_operations mapping_aops = { |
1da177e4 | 1496 | .sync_page = block_sync_page, |
e965f963 | 1497 | .migratepage = fail_migrate_page, |
1da177e4 LT |
1498 | }; |
1499 | ||
1500 | inode = new_inode(bdev->bd_inode->i_sb); | |
1501 | if (!inode) { | |
1502 | printk(KERN_WARNING | |
1503 | "XFS: Cannot allocate mapping inode for device %s\n", | |
1504 | XFS_BUFTARG_NAME(btp)); | |
1505 | return ENOMEM; | |
1506 | } | |
1507 | inode->i_mode = S_IFBLK; | |
1508 | inode->i_bdev = bdev; | |
1509 | inode->i_rdev = bdev->bd_dev; | |
1510 | bdi = blk_get_backing_dev_info(bdev); | |
1511 | if (!bdi) | |
1512 | bdi = &default_backing_dev_info; | |
1513 | mapping = &inode->i_data; | |
1514 | mapping->a_ops = &mapping_aops; | |
1515 | mapping->backing_dev_info = bdi; | |
1516 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
ce8e922c | 1517 | btp->bt_mapping = mapping; |
1da177e4 LT |
1518 | return 0; |
1519 | } | |
1520 | ||
a6867a68 DC |
1521 | STATIC int |
1522 | xfs_alloc_delwrite_queue( | |
1523 | xfs_buftarg_t *btp) | |
1524 | { | |
1525 | int error = 0; | |
1526 | ||
1527 | INIT_LIST_HEAD(&btp->bt_list); | |
1528 | INIT_LIST_HEAD(&btp->bt_delwrite_queue); | |
007c61c6 | 1529 | spin_lock_init(&btp->bt_delwrite_lock); |
a6867a68 DC |
1530 | btp->bt_flags = 0; |
1531 | btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd"); | |
1532 | if (IS_ERR(btp->bt_task)) { | |
1533 | error = PTR_ERR(btp->bt_task); | |
1534 | goto out_error; | |
1535 | } | |
1536 | xfs_register_buftarg(btp); | |
1537 | out_error: | |
1538 | return error; | |
1539 | } | |
1540 | ||
1da177e4 LT |
1541 | xfs_buftarg_t * |
1542 | xfs_alloc_buftarg( | |
1543 | struct block_device *bdev, | |
1544 | int external) | |
1545 | { | |
1546 | xfs_buftarg_t *btp; | |
1547 | ||
1548 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP); | |
1549 | ||
ce8e922c NS |
1550 | btp->bt_dev = bdev->bd_dev; |
1551 | btp->bt_bdev = bdev; | |
1da177e4 LT |
1552 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1553 | goto error; | |
1554 | if (xfs_mapping_buftarg(btp, bdev)) | |
1555 | goto error; | |
a6867a68 DC |
1556 | if (xfs_alloc_delwrite_queue(btp)) |
1557 | goto error; | |
1da177e4 LT |
1558 | xfs_alloc_bufhash(btp, external); |
1559 | return btp; | |
1560 | ||
1561 | error: | |
1562 | kmem_free(btp, sizeof(*btp)); | |
1563 | return NULL; | |
1564 | } | |
1565 | ||
1566 | ||
1567 | /* | |
ce8e922c | 1568 | * Delayed write buffer handling |
1da177e4 | 1569 | */ |
1da177e4 | 1570 | STATIC void |
ce8e922c NS |
1571 | xfs_buf_delwri_queue( |
1572 | xfs_buf_t *bp, | |
1da177e4 LT |
1573 | int unlock) |
1574 | { | |
ce8e922c NS |
1575 | struct list_head *dwq = &bp->b_target->bt_delwrite_queue; |
1576 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; | |
a6867a68 | 1577 | |
ce8e922c NS |
1578 | XB_TRACE(bp, "delwri_q", (long)unlock); |
1579 | ASSERT((bp->b_flags&(XBF_DELWRI|XBF_ASYNC)) == (XBF_DELWRI|XBF_ASYNC)); | |
1da177e4 | 1580 | |
a6867a68 | 1581 | spin_lock(dwlk); |
1da177e4 | 1582 | /* If already in the queue, dequeue and place at tail */ |
ce8e922c NS |
1583 | if (!list_empty(&bp->b_list)) { |
1584 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1585 | if (unlock) | |
1586 | atomic_dec(&bp->b_hold); | |
1587 | list_del(&bp->b_list); | |
1da177e4 LT |
1588 | } |
1589 | ||
ce8e922c NS |
1590 | bp->b_flags |= _XBF_DELWRI_Q; |
1591 | list_add_tail(&bp->b_list, dwq); | |
1592 | bp->b_queuetime = jiffies; | |
a6867a68 | 1593 | spin_unlock(dwlk); |
1da177e4 LT |
1594 | |
1595 | if (unlock) | |
ce8e922c | 1596 | xfs_buf_unlock(bp); |
1da177e4 LT |
1597 | } |
1598 | ||
1599 | void | |
ce8e922c NS |
1600 | xfs_buf_delwri_dequeue( |
1601 | xfs_buf_t *bp) | |
1da177e4 | 1602 | { |
ce8e922c | 1603 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; |
1da177e4 LT |
1604 | int dequeued = 0; |
1605 | ||
a6867a68 | 1606 | spin_lock(dwlk); |
ce8e922c NS |
1607 | if ((bp->b_flags & XBF_DELWRI) && !list_empty(&bp->b_list)) { |
1608 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1609 | list_del_init(&bp->b_list); | |
1da177e4 LT |
1610 | dequeued = 1; |
1611 | } | |
ce8e922c | 1612 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); |
a6867a68 | 1613 | spin_unlock(dwlk); |
1da177e4 LT |
1614 | |
1615 | if (dequeued) | |
ce8e922c | 1616 | xfs_buf_rele(bp); |
1da177e4 | 1617 | |
ce8e922c | 1618 | XB_TRACE(bp, "delwri_dq", (long)dequeued); |
1da177e4 LT |
1619 | } |
1620 | ||
1621 | STATIC void | |
ce8e922c | 1622 | xfs_buf_runall_queues( |
1da177e4 LT |
1623 | struct workqueue_struct *queue) |
1624 | { | |
1625 | flush_workqueue(queue); | |
1626 | } | |
1627 | ||
1da177e4 | 1628 | STATIC int |
23ea4032 | 1629 | xfsbufd_wakeup( |
15c84a47 NS |
1630 | int priority, |
1631 | gfp_t mask) | |
1da177e4 | 1632 | { |
da7f93e9 | 1633 | xfs_buftarg_t *btp; |
a6867a68 DC |
1634 | |
1635 | spin_lock(&xfs_buftarg_lock); | |
da7f93e9 | 1636 | list_for_each_entry(btp, &xfs_buftarg_list, bt_list) { |
ce8e922c | 1637 | if (test_bit(XBT_FORCE_SLEEP, &btp->bt_flags)) |
a6867a68 | 1638 | continue; |
ce8e922c | 1639 | set_bit(XBT_FORCE_FLUSH, &btp->bt_flags); |
a6867a68 DC |
1640 | wake_up_process(btp->bt_task); |
1641 | } | |
1642 | spin_unlock(&xfs_buftarg_lock); | |
1da177e4 LT |
1643 | return 0; |
1644 | } | |
1645 | ||
585e6d88 DC |
1646 | /* |
1647 | * Move as many buffers as specified to the supplied list | |
1648 | * idicating if we skipped any buffers to prevent deadlocks. | |
1649 | */ | |
1650 | STATIC int | |
1651 | xfs_buf_delwri_split( | |
1652 | xfs_buftarg_t *target, | |
1653 | struct list_head *list, | |
5e6a07df | 1654 | unsigned long age) |
585e6d88 DC |
1655 | { |
1656 | xfs_buf_t *bp, *n; | |
1657 | struct list_head *dwq = &target->bt_delwrite_queue; | |
1658 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1659 | int skipped = 0; | |
5e6a07df | 1660 | int force; |
585e6d88 | 1661 | |
5e6a07df | 1662 | force = test_and_clear_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
585e6d88 DC |
1663 | INIT_LIST_HEAD(list); |
1664 | spin_lock(dwlk); | |
1665 | list_for_each_entry_safe(bp, n, dwq, b_list) { | |
1666 | XB_TRACE(bp, "walkq1", (long)xfs_buf_ispin(bp)); | |
1667 | ASSERT(bp->b_flags & XBF_DELWRI); | |
1668 | ||
1669 | if (!xfs_buf_ispin(bp) && !xfs_buf_cond_lock(bp)) { | |
5e6a07df | 1670 | if (!force && |
585e6d88 DC |
1671 | time_before(jiffies, bp->b_queuetime + age)) { |
1672 | xfs_buf_unlock(bp); | |
1673 | break; | |
1674 | } | |
1675 | ||
1676 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q| | |
1677 | _XBF_RUN_QUEUES); | |
1678 | bp->b_flags |= XBF_WRITE; | |
1679 | list_move_tail(&bp->b_list, list); | |
1680 | } else | |
1681 | skipped++; | |
1682 | } | |
1683 | spin_unlock(dwlk); | |
1684 | ||
1685 | return skipped; | |
1686 | ||
1687 | } | |
1688 | ||
1da177e4 | 1689 | STATIC int |
23ea4032 | 1690 | xfsbufd( |
585e6d88 | 1691 | void *data) |
1da177e4 | 1692 | { |
585e6d88 DC |
1693 | struct list_head tmp; |
1694 | xfs_buftarg_t *target = (xfs_buftarg_t *)data; | |
1695 | int count; | |
1696 | xfs_buf_t *bp; | |
1da177e4 | 1697 | |
1da177e4 LT |
1698 | current->flags |= PF_MEMALLOC; |
1699 | ||
978c7b2f RW |
1700 | set_freezable(); |
1701 | ||
1da177e4 | 1702 | do { |
3e1d1d28 | 1703 | if (unlikely(freezing(current))) { |
ce8e922c | 1704 | set_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
3e1d1d28 | 1705 | refrigerator(); |
abd0cf7a | 1706 | } else { |
ce8e922c | 1707 | clear_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
abd0cf7a | 1708 | } |
1da177e4 | 1709 | |
15c84a47 NS |
1710 | schedule_timeout_interruptible( |
1711 | xfs_buf_timer_centisecs * msecs_to_jiffies(10)); | |
1da177e4 | 1712 | |
585e6d88 | 1713 | xfs_buf_delwri_split(target, &tmp, |
5e6a07df | 1714 | xfs_buf_age_centisecs * msecs_to_jiffies(10)); |
1da177e4 | 1715 | |
585e6d88 | 1716 | count = 0; |
1da177e4 | 1717 | while (!list_empty(&tmp)) { |
ce8e922c NS |
1718 | bp = list_entry(tmp.next, xfs_buf_t, b_list); |
1719 | ASSERT(target == bp->b_target); | |
1da177e4 | 1720 | |
ce8e922c NS |
1721 | list_del_init(&bp->b_list); |
1722 | xfs_buf_iostrategy(bp); | |
585e6d88 | 1723 | count++; |
1da177e4 LT |
1724 | } |
1725 | ||
1726 | if (as_list_len > 0) | |
1727 | purge_addresses(); | |
f07c2250 NS |
1728 | if (count) |
1729 | blk_run_address_space(target->bt_mapping); | |
1da177e4 | 1730 | |
4df08c52 | 1731 | } while (!kthread_should_stop()); |
1da177e4 | 1732 | |
4df08c52 | 1733 | return 0; |
1da177e4 LT |
1734 | } |
1735 | ||
1736 | /* | |
ce8e922c NS |
1737 | * Go through all incore buffers, and release buffers if they belong to |
1738 | * the given device. This is used in filesystem error handling to | |
1739 | * preserve the consistency of its metadata. | |
1da177e4 LT |
1740 | */ |
1741 | int | |
1742 | xfs_flush_buftarg( | |
585e6d88 DC |
1743 | xfs_buftarg_t *target, |
1744 | int wait) | |
1da177e4 | 1745 | { |
585e6d88 DC |
1746 | struct list_head tmp; |
1747 | xfs_buf_t *bp, *n; | |
1748 | int pincount = 0; | |
1da177e4 | 1749 | |
ce8e922c NS |
1750 | xfs_buf_runall_queues(xfsdatad_workqueue); |
1751 | xfs_buf_runall_queues(xfslogd_workqueue); | |
1da177e4 | 1752 | |
5e6a07df DC |
1753 | set_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
1754 | pincount = xfs_buf_delwri_split(target, &tmp, 0); | |
1da177e4 LT |
1755 | |
1756 | /* | |
1757 | * Dropped the delayed write list lock, now walk the temporary list | |
1758 | */ | |
ce8e922c | 1759 | list_for_each_entry_safe(bp, n, &tmp, b_list) { |
585e6d88 | 1760 | ASSERT(target == bp->b_target); |
1da177e4 | 1761 | if (wait) |
ce8e922c | 1762 | bp->b_flags &= ~XBF_ASYNC; |
1da177e4 | 1763 | else |
ce8e922c | 1764 | list_del_init(&bp->b_list); |
1da177e4 | 1765 | |
ce8e922c | 1766 | xfs_buf_iostrategy(bp); |
1da177e4 LT |
1767 | } |
1768 | ||
f07c2250 NS |
1769 | if (wait) |
1770 | blk_run_address_space(target->bt_mapping); | |
1771 | ||
1da177e4 LT |
1772 | /* |
1773 | * Remaining list items must be flushed before returning | |
1774 | */ | |
1775 | while (!list_empty(&tmp)) { | |
ce8e922c | 1776 | bp = list_entry(tmp.next, xfs_buf_t, b_list); |
1da177e4 | 1777 | |
ce8e922c NS |
1778 | list_del_init(&bp->b_list); |
1779 | xfs_iowait(bp); | |
1780 | xfs_buf_relse(bp); | |
1da177e4 LT |
1781 | } |
1782 | ||
1da177e4 LT |
1783 | return pincount; |
1784 | } | |
1785 | ||
04d8b284 | 1786 | int __init |
ce8e922c | 1787 | xfs_buf_init(void) |
1da177e4 | 1788 | { |
ce8e922c NS |
1789 | #ifdef XFS_BUF_TRACE |
1790 | xfs_buf_trace_buf = ktrace_alloc(XFS_BUF_TRACE_SIZE, KM_SLEEP); | |
04d8b284 CH |
1791 | #endif |
1792 | ||
8758280f NS |
1793 | xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf", |
1794 | KM_ZONE_HWALIGN, NULL); | |
ce8e922c | 1795 | if (!xfs_buf_zone) |
04d8b284 CH |
1796 | goto out_free_trace_buf; |
1797 | ||
b4337692 | 1798 | xfslogd_workqueue = create_workqueue("xfslogd"); |
23ea4032 | 1799 | if (!xfslogd_workqueue) |
04d8b284 | 1800 | goto out_free_buf_zone; |
1da177e4 | 1801 | |
b4337692 | 1802 | xfsdatad_workqueue = create_workqueue("xfsdatad"); |
23ea4032 CH |
1803 | if (!xfsdatad_workqueue) |
1804 | goto out_destroy_xfslogd_workqueue; | |
1da177e4 | 1805 | |
8e1f936b | 1806 | register_shrinker(&xfs_buf_shake); |
23ea4032 | 1807 | return 0; |
1da177e4 | 1808 | |
23ea4032 CH |
1809 | out_destroy_xfslogd_workqueue: |
1810 | destroy_workqueue(xfslogd_workqueue); | |
23ea4032 | 1811 | out_free_buf_zone: |
ce8e922c | 1812 | kmem_zone_destroy(xfs_buf_zone); |
04d8b284 | 1813 | out_free_trace_buf: |
ce8e922c NS |
1814 | #ifdef XFS_BUF_TRACE |
1815 | ktrace_free(xfs_buf_trace_buf); | |
23ea4032 | 1816 | #endif |
8758280f | 1817 | return -ENOMEM; |
1da177e4 LT |
1818 | } |
1819 | ||
1da177e4 | 1820 | void |
ce8e922c | 1821 | xfs_buf_terminate(void) |
1da177e4 | 1822 | { |
8e1f936b | 1823 | unregister_shrinker(&xfs_buf_shake); |
04d8b284 CH |
1824 | destroy_workqueue(xfsdatad_workqueue); |
1825 | destroy_workqueue(xfslogd_workqueue); | |
ce8e922c NS |
1826 | kmem_zone_destroy(xfs_buf_zone); |
1827 | #ifdef XFS_BUF_TRACE | |
1828 | ktrace_free(xfs_buf_trace_buf); | |
1da177e4 | 1829 | #endif |
1da177e4 | 1830 | } |
e6a0e9cd TS |
1831 | |
1832 | #ifdef CONFIG_KDB_MODULES | |
1833 | struct list_head * | |
1834 | xfs_get_buftarg_list(void) | |
1835 | { | |
1836 | return &xfs_buftarg_list; | |
1837 | } | |
1838 | #endif |