Commit | Line | Data |
---|---|---|
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, | |
d63f154a | 61 | (void *)(unsigned long)bp->b_sema.count, |
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 | ||
27e88bf6 FB |
168 | /* |
169 | * Mapping of multi-page buffers into contiguous virtual space | |
170 | */ | |
171 | ||
172 | typedef struct a_list { | |
173 | void *vm_addr; | |
174 | struct a_list *next; | |
175 | } a_list_t; | |
176 | ||
177 | static a_list_t *as_free_head; | |
178 | static int as_list_len; | |
179 | static DEFINE_SPINLOCK(as_lock); | |
180 | ||
181 | /* | |
182 | * Try to batch vunmaps because they are costly. | |
183 | */ | |
184 | STATIC void | |
185 | free_address( | |
186 | void *addr) | |
187 | { | |
188 | a_list_t *aentry; | |
189 | ||
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 | ||
203 | aentry = kmalloc(sizeof(a_list_t), GFP_NOWAIT); | |
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 | ||
1da177e4 | 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); | |
b4dd330b | 256 | init_completion(&bp->b_iowait); |
ce8e922c NS |
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 | 312 | if (bp->b_pages != bp->b_page_array) { |
f0e2d93c | 313 | kmem_free(bp->b_pages); |
1da177e4 LT |
314 | } |
315 | } | |
316 | ||
317 | /* | |
318 | * Releases the specified buffer. | |
319 | * | |
320 | * The modification state of any associated pages is left unchanged. | |
ce8e922c | 321 | * The buffer most not be on any hash - use xfs_buf_rele instead for |
1da177e4 LT |
322 | * hashed and refcounted buffers |
323 | */ | |
324 | void | |
ce8e922c | 325 | xfs_buf_free( |
1da177e4 LT |
326 | xfs_buf_t *bp) |
327 | { | |
ce8e922c | 328 | XB_TRACE(bp, "free", 0); |
1da177e4 | 329 | |
ce8e922c | 330 | ASSERT(list_empty(&bp->b_hash_list)); |
1da177e4 | 331 | |
1fa40b01 | 332 | if (bp->b_flags & (_XBF_PAGE_CACHE|_XBF_PAGES)) { |
1da177e4 LT |
333 | uint i; |
334 | ||
ce8e922c | 335 | if ((bp->b_flags & XBF_MAPPED) && (bp->b_page_count > 1)) |
27e88bf6 | 336 | free_address(bp->b_addr - bp->b_offset); |
1da177e4 | 337 | |
948ecdb4 NS |
338 | for (i = 0; i < bp->b_page_count; i++) { |
339 | struct page *page = bp->b_pages[i]; | |
340 | ||
1fa40b01 CH |
341 | if (bp->b_flags & _XBF_PAGE_CACHE) |
342 | ASSERT(!PagePrivate(page)); | |
948ecdb4 NS |
343 | page_cache_release(page); |
344 | } | |
ce8e922c | 345 | _xfs_buf_free_pages(bp); |
1da177e4 LT |
346 | } |
347 | ||
ce8e922c | 348 | xfs_buf_deallocate(bp); |
1da177e4 LT |
349 | } |
350 | ||
351 | /* | |
352 | * Finds all pages for buffer in question and builds it's page list. | |
353 | */ | |
354 | STATIC int | |
ce8e922c | 355 | _xfs_buf_lookup_pages( |
1da177e4 LT |
356 | xfs_buf_t *bp, |
357 | uint flags) | |
358 | { | |
ce8e922c NS |
359 | struct address_space *mapping = bp->b_target->bt_mapping; |
360 | size_t blocksize = bp->b_target->bt_bsize; | |
361 | size_t size = bp->b_count_desired; | |
1da177e4 | 362 | size_t nbytes, offset; |
ce8e922c | 363 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 LT |
364 | unsigned short page_count, i; |
365 | pgoff_t first; | |
204ab25f | 366 | xfs_off_t end; |
1da177e4 LT |
367 | int error; |
368 | ||
ce8e922c NS |
369 | end = bp->b_file_offset + bp->b_buffer_length; |
370 | page_count = xfs_buf_btoc(end) - xfs_buf_btoct(bp->b_file_offset); | |
1da177e4 | 371 | |
ce8e922c | 372 | error = _xfs_buf_get_pages(bp, page_count, flags); |
1da177e4 LT |
373 | if (unlikely(error)) |
374 | return error; | |
ce8e922c | 375 | bp->b_flags |= _XBF_PAGE_CACHE; |
1da177e4 | 376 | |
ce8e922c NS |
377 | offset = bp->b_offset; |
378 | first = bp->b_file_offset >> PAGE_CACHE_SHIFT; | |
1da177e4 | 379 | |
ce8e922c | 380 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
381 | struct page *page; |
382 | uint retries = 0; | |
383 | ||
384 | retry: | |
385 | page = find_or_create_page(mapping, first + i, gfp_mask); | |
386 | if (unlikely(page == NULL)) { | |
ce8e922c NS |
387 | if (flags & XBF_READ_AHEAD) { |
388 | bp->b_page_count = i; | |
6ab455ee CH |
389 | for (i = 0; i < bp->b_page_count; i++) |
390 | unlock_page(bp->b_pages[i]); | |
1da177e4 LT |
391 | return -ENOMEM; |
392 | } | |
393 | ||
394 | /* | |
395 | * This could deadlock. | |
396 | * | |
397 | * But until all the XFS lowlevel code is revamped to | |
398 | * handle buffer allocation failures we can't do much. | |
399 | */ | |
400 | if (!(++retries % 100)) | |
401 | printk(KERN_ERR | |
402 | "XFS: possible memory allocation " | |
403 | "deadlock in %s (mode:0x%x)\n", | |
34a622b2 | 404 | __func__, gfp_mask); |
1da177e4 | 405 | |
ce8e922c | 406 | XFS_STATS_INC(xb_page_retries); |
23ea4032 | 407 | xfsbufd_wakeup(0, gfp_mask); |
3fcfab16 | 408 | congestion_wait(WRITE, HZ/50); |
1da177e4 LT |
409 | goto retry; |
410 | } | |
411 | ||
ce8e922c | 412 | XFS_STATS_INC(xb_page_found); |
1da177e4 LT |
413 | |
414 | nbytes = min_t(size_t, size, PAGE_CACHE_SIZE - offset); | |
415 | size -= nbytes; | |
416 | ||
948ecdb4 | 417 | ASSERT(!PagePrivate(page)); |
1da177e4 LT |
418 | if (!PageUptodate(page)) { |
419 | page_count--; | |
6ab455ee CH |
420 | if (blocksize >= PAGE_CACHE_SIZE) { |
421 | if (flags & XBF_READ) | |
422 | bp->b_flags |= _XBF_PAGE_LOCKED; | |
423 | } else if (!PagePrivate(page)) { | |
1da177e4 LT |
424 | if (test_page_region(page, offset, nbytes)) |
425 | page_count++; | |
426 | } | |
427 | } | |
428 | ||
ce8e922c | 429 | bp->b_pages[i] = page; |
1da177e4 LT |
430 | offset = 0; |
431 | } | |
432 | ||
6ab455ee CH |
433 | if (!(bp->b_flags & _XBF_PAGE_LOCKED)) { |
434 | for (i = 0; i < bp->b_page_count; i++) | |
435 | unlock_page(bp->b_pages[i]); | |
436 | } | |
437 | ||
ce8e922c NS |
438 | if (page_count == bp->b_page_count) |
439 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 440 | |
ce8e922c | 441 | XB_TRACE(bp, "lookup_pages", (long)page_count); |
1da177e4 LT |
442 | return error; |
443 | } | |
444 | ||
445 | /* | |
446 | * Map buffer into kernel address-space if nessecary. | |
447 | */ | |
448 | STATIC int | |
ce8e922c | 449 | _xfs_buf_map_pages( |
1da177e4 LT |
450 | xfs_buf_t *bp, |
451 | uint flags) | |
452 | { | |
453 | /* A single page buffer is always mappable */ | |
ce8e922c NS |
454 | if (bp->b_page_count == 1) { |
455 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; | |
456 | bp->b_flags |= XBF_MAPPED; | |
457 | } else if (flags & XBF_MAPPED) { | |
27e88bf6 FB |
458 | if (as_list_len > 64) |
459 | purge_addresses(); | |
7fdf5824 FB |
460 | bp->b_addr = vmap(bp->b_pages, bp->b_page_count, |
461 | VM_MAP, PAGE_KERNEL); | |
ce8e922c | 462 | if (unlikely(bp->b_addr == NULL)) |
1da177e4 | 463 | return -ENOMEM; |
ce8e922c NS |
464 | bp->b_addr += bp->b_offset; |
465 | bp->b_flags |= XBF_MAPPED; | |
1da177e4 LT |
466 | } |
467 | ||
468 | return 0; | |
469 | } | |
470 | ||
471 | /* | |
472 | * Finding and Reading Buffers | |
473 | */ | |
474 | ||
475 | /* | |
ce8e922c | 476 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 LT |
477 | * a given range of an inode. The buffer is returned |
478 | * locked. If other overlapping buffers exist, they are | |
479 | * released before the new buffer is created and locked, | |
480 | * which may imply that this call will block until those buffers | |
481 | * are unlocked. No I/O is implied by this call. | |
482 | */ | |
483 | xfs_buf_t * | |
ce8e922c | 484 | _xfs_buf_find( |
1da177e4 | 485 | xfs_buftarg_t *btp, /* block device target */ |
204ab25f | 486 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 487 | size_t isize, /* length of range */ |
ce8e922c NS |
488 | xfs_buf_flags_t flags, |
489 | xfs_buf_t *new_bp) | |
1da177e4 | 490 | { |
204ab25f | 491 | xfs_off_t range_base; |
1da177e4 LT |
492 | size_t range_length; |
493 | xfs_bufhash_t *hash; | |
ce8e922c | 494 | xfs_buf_t *bp, *n; |
1da177e4 LT |
495 | |
496 | range_base = (ioff << BBSHIFT); | |
497 | range_length = (isize << BBSHIFT); | |
498 | ||
499 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
ce8e922c | 500 | ASSERT(!(range_length < (1 << btp->bt_sshift))); |
204ab25f | 501 | ASSERT(!(range_base & (xfs_off_t)btp->bt_smask)); |
1da177e4 LT |
502 | |
503 | hash = &btp->bt_hash[hash_long((unsigned long)ioff, btp->bt_hashshift)]; | |
504 | ||
505 | spin_lock(&hash->bh_lock); | |
506 | ||
ce8e922c NS |
507 | list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) { |
508 | ASSERT(btp == bp->b_target); | |
509 | if (bp->b_file_offset == range_base && | |
510 | bp->b_buffer_length == range_length) { | |
1da177e4 | 511 | /* |
ce8e922c | 512 | * If we look at something, bring it to the |
1da177e4 LT |
513 | * front of the list for next time. |
514 | */ | |
ce8e922c NS |
515 | atomic_inc(&bp->b_hold); |
516 | list_move(&bp->b_hash_list, &hash->bh_list); | |
1da177e4 LT |
517 | goto found; |
518 | } | |
519 | } | |
520 | ||
521 | /* No match found */ | |
ce8e922c NS |
522 | if (new_bp) { |
523 | _xfs_buf_initialize(new_bp, btp, range_base, | |
1da177e4 | 524 | range_length, flags); |
ce8e922c NS |
525 | new_bp->b_hash = hash; |
526 | list_add(&new_bp->b_hash_list, &hash->bh_list); | |
1da177e4 | 527 | } else { |
ce8e922c | 528 | XFS_STATS_INC(xb_miss_locked); |
1da177e4 LT |
529 | } |
530 | ||
531 | spin_unlock(&hash->bh_lock); | |
ce8e922c | 532 | return new_bp; |
1da177e4 LT |
533 | |
534 | found: | |
535 | spin_unlock(&hash->bh_lock); | |
536 | ||
537 | /* Attempt to get the semaphore without sleeping, | |
538 | * if this does not work then we need to drop the | |
539 | * spinlock and do a hard attempt on the semaphore. | |
540 | */ | |
ce8e922c NS |
541 | if (down_trylock(&bp->b_sema)) { |
542 | if (!(flags & XBF_TRYLOCK)) { | |
1da177e4 | 543 | /* wait for buffer ownership */ |
ce8e922c NS |
544 | XB_TRACE(bp, "get_lock", 0); |
545 | xfs_buf_lock(bp); | |
546 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 LT |
547 | } else { |
548 | /* We asked for a trylock and failed, no need | |
549 | * to look at file offset and length here, we | |
ce8e922c NS |
550 | * know that this buffer at least overlaps our |
551 | * buffer and is locked, therefore our buffer | |
552 | * either does not exist, or is this buffer. | |
1da177e4 | 553 | */ |
ce8e922c NS |
554 | xfs_buf_rele(bp); |
555 | XFS_STATS_INC(xb_busy_locked); | |
556 | return NULL; | |
1da177e4 LT |
557 | } |
558 | } else { | |
559 | /* trylock worked */ | |
ce8e922c | 560 | XB_SET_OWNER(bp); |
1da177e4 LT |
561 | } |
562 | ||
ce8e922c NS |
563 | if (bp->b_flags & XBF_STALE) { |
564 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
565 | bp->b_flags &= XBF_MAPPED; | |
2f926587 | 566 | } |
ce8e922c NS |
567 | XB_TRACE(bp, "got_lock", 0); |
568 | XFS_STATS_INC(xb_get_locked); | |
569 | return bp; | |
1da177e4 LT |
570 | } |
571 | ||
572 | /* | |
ce8e922c | 573 | * Assembles a buffer covering the specified range. |
1da177e4 LT |
574 | * Storage in memory for all portions of the buffer will be allocated, |
575 | * although backing storage may not be. | |
576 | */ | |
577 | xfs_buf_t * | |
ce8e922c | 578 | xfs_buf_get_flags( |
1da177e4 | 579 | xfs_buftarg_t *target,/* target for buffer */ |
204ab25f | 580 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 581 | size_t isize, /* length of range */ |
ce8e922c | 582 | xfs_buf_flags_t flags) |
1da177e4 | 583 | { |
ce8e922c | 584 | xfs_buf_t *bp, *new_bp; |
1da177e4 LT |
585 | int error = 0, i; |
586 | ||
ce8e922c NS |
587 | new_bp = xfs_buf_allocate(flags); |
588 | if (unlikely(!new_bp)) | |
1da177e4 LT |
589 | return NULL; |
590 | ||
ce8e922c NS |
591 | bp = _xfs_buf_find(target, ioff, isize, flags, new_bp); |
592 | if (bp == new_bp) { | |
593 | error = _xfs_buf_lookup_pages(bp, flags); | |
1da177e4 LT |
594 | if (error) |
595 | goto no_buffer; | |
596 | } else { | |
ce8e922c NS |
597 | xfs_buf_deallocate(new_bp); |
598 | if (unlikely(bp == NULL)) | |
1da177e4 LT |
599 | return NULL; |
600 | } | |
601 | ||
ce8e922c NS |
602 | for (i = 0; i < bp->b_page_count; i++) |
603 | mark_page_accessed(bp->b_pages[i]); | |
1da177e4 | 604 | |
ce8e922c NS |
605 | if (!(bp->b_flags & XBF_MAPPED)) { |
606 | error = _xfs_buf_map_pages(bp, flags); | |
1da177e4 LT |
607 | if (unlikely(error)) { |
608 | printk(KERN_WARNING "%s: failed to map pages\n", | |
34a622b2 | 609 | __func__); |
1da177e4 LT |
610 | goto no_buffer; |
611 | } | |
612 | } | |
613 | ||
ce8e922c | 614 | XFS_STATS_INC(xb_get); |
1da177e4 LT |
615 | |
616 | /* | |
617 | * Always fill in the block number now, the mapped cases can do | |
618 | * their own overlay of this later. | |
619 | */ | |
ce8e922c NS |
620 | bp->b_bn = ioff; |
621 | bp->b_count_desired = bp->b_buffer_length; | |
1da177e4 | 622 | |
ce8e922c NS |
623 | XB_TRACE(bp, "get", (unsigned long)flags); |
624 | return bp; | |
1da177e4 LT |
625 | |
626 | no_buffer: | |
ce8e922c NS |
627 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
628 | xfs_buf_unlock(bp); | |
629 | xfs_buf_rele(bp); | |
1da177e4 LT |
630 | return NULL; |
631 | } | |
632 | ||
5d765b97 CH |
633 | STATIC int |
634 | _xfs_buf_read( | |
635 | xfs_buf_t *bp, | |
636 | xfs_buf_flags_t flags) | |
637 | { | |
638 | int status; | |
639 | ||
640 | XB_TRACE(bp, "_xfs_buf_read", (unsigned long)flags); | |
641 | ||
642 | ASSERT(!(flags & (XBF_DELWRI|XBF_WRITE))); | |
643 | ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL); | |
644 | ||
645 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_DELWRI | \ | |
646 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
647 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | \ | |
648 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
649 | ||
650 | status = xfs_buf_iorequest(bp); | |
651 | if (!status && !(flags & XBF_ASYNC)) | |
652 | status = xfs_buf_iowait(bp); | |
653 | return status; | |
654 | } | |
655 | ||
1da177e4 LT |
656 | xfs_buf_t * |
657 | xfs_buf_read_flags( | |
658 | xfs_buftarg_t *target, | |
204ab25f | 659 | xfs_off_t ioff, |
1da177e4 | 660 | size_t isize, |
ce8e922c | 661 | xfs_buf_flags_t flags) |
1da177e4 | 662 | { |
ce8e922c NS |
663 | xfs_buf_t *bp; |
664 | ||
665 | flags |= XBF_READ; | |
666 | ||
667 | bp = xfs_buf_get_flags(target, ioff, isize, flags); | |
668 | if (bp) { | |
669 | if (!XFS_BUF_ISDONE(bp)) { | |
670 | XB_TRACE(bp, "read", (unsigned long)flags); | |
671 | XFS_STATS_INC(xb_get_read); | |
5d765b97 | 672 | _xfs_buf_read(bp, flags); |
ce8e922c NS |
673 | } else if (flags & XBF_ASYNC) { |
674 | XB_TRACE(bp, "read_async", (unsigned long)flags); | |
1da177e4 LT |
675 | /* |
676 | * Read ahead call which is already satisfied, | |
677 | * drop the buffer | |
678 | */ | |
679 | goto no_buffer; | |
680 | } else { | |
ce8e922c | 681 | XB_TRACE(bp, "read_done", (unsigned long)flags); |
1da177e4 | 682 | /* We do not want read in the flags */ |
ce8e922c | 683 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
684 | } |
685 | } | |
686 | ||
ce8e922c | 687 | return bp; |
1da177e4 LT |
688 | |
689 | no_buffer: | |
ce8e922c NS |
690 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
691 | xfs_buf_unlock(bp); | |
692 | xfs_buf_rele(bp); | |
1da177e4 LT |
693 | return NULL; |
694 | } | |
695 | ||
1da177e4 | 696 | /* |
ce8e922c NS |
697 | * If we are not low on memory then do the readahead in a deadlock |
698 | * safe manner. | |
1da177e4 LT |
699 | */ |
700 | void | |
ce8e922c | 701 | xfs_buf_readahead( |
1da177e4 | 702 | xfs_buftarg_t *target, |
204ab25f | 703 | xfs_off_t ioff, |
1da177e4 | 704 | size_t isize, |
ce8e922c | 705 | xfs_buf_flags_t flags) |
1da177e4 LT |
706 | { |
707 | struct backing_dev_info *bdi; | |
708 | ||
ce8e922c | 709 | bdi = target->bt_mapping->backing_dev_info; |
1da177e4 LT |
710 | if (bdi_read_congested(bdi)) |
711 | return; | |
712 | ||
ce8e922c | 713 | flags |= (XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD); |
1da177e4 LT |
714 | xfs_buf_read_flags(target, ioff, isize, flags); |
715 | } | |
716 | ||
717 | xfs_buf_t * | |
ce8e922c | 718 | xfs_buf_get_empty( |
1da177e4 LT |
719 | size_t len, |
720 | xfs_buftarg_t *target) | |
721 | { | |
ce8e922c | 722 | xfs_buf_t *bp; |
1da177e4 | 723 | |
ce8e922c NS |
724 | bp = xfs_buf_allocate(0); |
725 | if (bp) | |
726 | _xfs_buf_initialize(bp, target, 0, len, 0); | |
727 | return bp; | |
1da177e4 LT |
728 | } |
729 | ||
730 | static inline struct page * | |
731 | mem_to_page( | |
732 | void *addr) | |
733 | { | |
9e2779fa | 734 | if ((!is_vmalloc_addr(addr))) { |
1da177e4 LT |
735 | return virt_to_page(addr); |
736 | } else { | |
737 | return vmalloc_to_page(addr); | |
738 | } | |
739 | } | |
740 | ||
741 | int | |
ce8e922c NS |
742 | xfs_buf_associate_memory( |
743 | xfs_buf_t *bp, | |
1da177e4 LT |
744 | void *mem, |
745 | size_t len) | |
746 | { | |
747 | int rval; | |
748 | int i = 0; | |
d1afb678 LM |
749 | unsigned long pageaddr; |
750 | unsigned long offset; | |
751 | size_t buflen; | |
1da177e4 LT |
752 | int page_count; |
753 | ||
d1afb678 LM |
754 | pageaddr = (unsigned long)mem & PAGE_CACHE_MASK; |
755 | offset = (unsigned long)mem - pageaddr; | |
756 | buflen = PAGE_CACHE_ALIGN(len + offset); | |
757 | page_count = buflen >> PAGE_CACHE_SHIFT; | |
1da177e4 LT |
758 | |
759 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
760 | if (bp->b_pages) |
761 | _xfs_buf_free_pages(bp); | |
1da177e4 | 762 | |
ce8e922c NS |
763 | bp->b_pages = NULL; |
764 | bp->b_addr = mem; | |
1da177e4 | 765 | |
ce8e922c | 766 | rval = _xfs_buf_get_pages(bp, page_count, 0); |
1da177e4 LT |
767 | if (rval) |
768 | return rval; | |
769 | ||
ce8e922c | 770 | bp->b_offset = offset; |
d1afb678 LM |
771 | |
772 | for (i = 0; i < bp->b_page_count; i++) { | |
773 | bp->b_pages[i] = mem_to_page((void *)pageaddr); | |
774 | pageaddr += PAGE_CACHE_SIZE; | |
1da177e4 | 775 | } |
1da177e4 | 776 | |
d1afb678 LM |
777 | bp->b_count_desired = len; |
778 | bp->b_buffer_length = buflen; | |
ce8e922c | 779 | bp->b_flags |= XBF_MAPPED; |
6ab455ee | 780 | bp->b_flags &= ~_XBF_PAGE_LOCKED; |
1da177e4 LT |
781 | |
782 | return 0; | |
783 | } | |
784 | ||
785 | xfs_buf_t * | |
ce8e922c | 786 | xfs_buf_get_noaddr( |
1da177e4 LT |
787 | size_t len, |
788 | xfs_buftarg_t *target) | |
789 | { | |
1fa40b01 CH |
790 | unsigned long page_count = PAGE_ALIGN(len) >> PAGE_SHIFT; |
791 | int error, i; | |
1da177e4 | 792 | xfs_buf_t *bp; |
1da177e4 | 793 | |
ce8e922c | 794 | bp = xfs_buf_allocate(0); |
1da177e4 LT |
795 | if (unlikely(bp == NULL)) |
796 | goto fail; | |
ce8e922c | 797 | _xfs_buf_initialize(bp, target, 0, len, 0); |
1da177e4 | 798 | |
1fa40b01 CH |
799 | error = _xfs_buf_get_pages(bp, page_count, 0); |
800 | if (error) | |
1da177e4 LT |
801 | goto fail_free_buf; |
802 | ||
1fa40b01 CH |
803 | for (i = 0; i < page_count; i++) { |
804 | bp->b_pages[i] = alloc_page(GFP_KERNEL); | |
805 | if (!bp->b_pages[i]) | |
806 | goto fail_free_mem; | |
1da177e4 | 807 | } |
1fa40b01 | 808 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 809 | |
1fa40b01 CH |
810 | error = _xfs_buf_map_pages(bp, XBF_MAPPED); |
811 | if (unlikely(error)) { | |
812 | printk(KERN_WARNING "%s: failed to map pages\n", | |
34a622b2 | 813 | __func__); |
1da177e4 | 814 | goto fail_free_mem; |
1fa40b01 | 815 | } |
1da177e4 | 816 | |
ce8e922c | 817 | xfs_buf_unlock(bp); |
1da177e4 | 818 | |
1fa40b01 | 819 | XB_TRACE(bp, "no_daddr", len); |
1da177e4 | 820 | return bp; |
1fa40b01 | 821 | |
1da177e4 | 822 | fail_free_mem: |
1fa40b01 CH |
823 | while (--i >= 0) |
824 | __free_page(bp->b_pages[i]); | |
ca165b88 | 825 | _xfs_buf_free_pages(bp); |
1da177e4 | 826 | fail_free_buf: |
ca165b88 | 827 | xfs_buf_deallocate(bp); |
1da177e4 LT |
828 | fail: |
829 | return NULL; | |
830 | } | |
831 | ||
832 | /* | |
1da177e4 LT |
833 | * Increment reference count on buffer, to hold the buffer concurrently |
834 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
835 | * Must hold the buffer already to call this function. |
836 | */ | |
837 | void | |
ce8e922c NS |
838 | xfs_buf_hold( |
839 | xfs_buf_t *bp) | |
1da177e4 | 840 | { |
ce8e922c NS |
841 | atomic_inc(&bp->b_hold); |
842 | XB_TRACE(bp, "hold", 0); | |
1da177e4 LT |
843 | } |
844 | ||
845 | /* | |
ce8e922c NS |
846 | * Releases a hold on the specified buffer. If the |
847 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
848 | */ |
849 | void | |
ce8e922c NS |
850 | xfs_buf_rele( |
851 | xfs_buf_t *bp) | |
1da177e4 | 852 | { |
ce8e922c | 853 | xfs_bufhash_t *hash = bp->b_hash; |
1da177e4 | 854 | |
ce8e922c | 855 | XB_TRACE(bp, "rele", bp->b_relse); |
1da177e4 | 856 | |
fad3aa1e NS |
857 | if (unlikely(!hash)) { |
858 | ASSERT(!bp->b_relse); | |
859 | if (atomic_dec_and_test(&bp->b_hold)) | |
860 | xfs_buf_free(bp); | |
861 | return; | |
862 | } | |
863 | ||
3790689f | 864 | ASSERT(atomic_read(&bp->b_hold) > 0); |
ce8e922c NS |
865 | if (atomic_dec_and_lock(&bp->b_hold, &hash->bh_lock)) { |
866 | if (bp->b_relse) { | |
867 | atomic_inc(&bp->b_hold); | |
1da177e4 | 868 | spin_unlock(&hash->bh_lock); |
ce8e922c NS |
869 | (*(bp->b_relse)) (bp); |
870 | } else if (bp->b_flags & XBF_FS_MANAGED) { | |
1da177e4 | 871 | spin_unlock(&hash->bh_lock); |
1da177e4 | 872 | } else { |
ce8e922c NS |
873 | ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q))); |
874 | list_del_init(&bp->b_hash_list); | |
1da177e4 | 875 | spin_unlock(&hash->bh_lock); |
ce8e922c | 876 | xfs_buf_free(bp); |
1da177e4 LT |
877 | } |
878 | } | |
879 | } | |
880 | ||
881 | ||
882 | /* | |
883 | * Mutual exclusion on buffers. Locking model: | |
884 | * | |
885 | * Buffers associated with inodes for which buffer locking | |
886 | * is not enabled are not protected by semaphores, and are | |
887 | * assumed to be exclusively owned by the caller. There is a | |
888 | * spinlock in the buffer, used by the caller when concurrent | |
889 | * access is possible. | |
890 | */ | |
891 | ||
892 | /* | |
ce8e922c NS |
893 | * Locks a buffer object, if it is not already locked. |
894 | * Note that this in no way locks the underlying pages, so it is only | |
895 | * useful for synchronizing concurrent use of buffer objects, not for | |
896 | * synchronizing independent access to the underlying pages. | |
1da177e4 LT |
897 | */ |
898 | int | |
ce8e922c NS |
899 | xfs_buf_cond_lock( |
900 | xfs_buf_t *bp) | |
1da177e4 LT |
901 | { |
902 | int locked; | |
903 | ||
ce8e922c | 904 | locked = down_trylock(&bp->b_sema) == 0; |
1da177e4 | 905 | if (locked) { |
ce8e922c | 906 | XB_SET_OWNER(bp); |
1da177e4 | 907 | } |
ce8e922c NS |
908 | XB_TRACE(bp, "cond_lock", (long)locked); |
909 | return locked ? 0 : -EBUSY; | |
1da177e4 LT |
910 | } |
911 | ||
912 | #if defined(DEBUG) || defined(XFS_BLI_TRACE) | |
1da177e4 | 913 | int |
ce8e922c NS |
914 | xfs_buf_lock_value( |
915 | xfs_buf_t *bp) | |
1da177e4 | 916 | { |
adaa693b | 917 | return bp->b_sema.count; |
1da177e4 LT |
918 | } |
919 | #endif | |
920 | ||
921 | /* | |
ce8e922c NS |
922 | * Locks a buffer object. |
923 | * Note that this in no way locks the underlying pages, so it is only | |
924 | * useful for synchronizing concurrent use of buffer objects, not for | |
925 | * synchronizing independent access to the underlying pages. | |
1da177e4 | 926 | */ |
ce8e922c NS |
927 | void |
928 | xfs_buf_lock( | |
929 | xfs_buf_t *bp) | |
1da177e4 | 930 | { |
ce8e922c NS |
931 | XB_TRACE(bp, "lock", 0); |
932 | if (atomic_read(&bp->b_io_remaining)) | |
933 | blk_run_address_space(bp->b_target->bt_mapping); | |
934 | down(&bp->b_sema); | |
935 | XB_SET_OWNER(bp); | |
936 | XB_TRACE(bp, "locked", 0); | |
1da177e4 LT |
937 | } |
938 | ||
939 | /* | |
ce8e922c | 940 | * Releases the lock on the buffer object. |
2f926587 | 941 | * If the buffer is marked delwri but is not queued, do so before we |
ce8e922c | 942 | * unlock the buffer as we need to set flags correctly. We also need to |
2f926587 DC |
943 | * take a reference for the delwri queue because the unlocker is going to |
944 | * drop their's and they don't know we just queued it. | |
1da177e4 LT |
945 | */ |
946 | void | |
ce8e922c NS |
947 | xfs_buf_unlock( |
948 | xfs_buf_t *bp) | |
1da177e4 | 949 | { |
ce8e922c NS |
950 | if ((bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)) == XBF_DELWRI) { |
951 | atomic_inc(&bp->b_hold); | |
952 | bp->b_flags |= XBF_ASYNC; | |
953 | xfs_buf_delwri_queue(bp, 0); | |
2f926587 DC |
954 | } |
955 | ||
ce8e922c NS |
956 | XB_CLEAR_OWNER(bp); |
957 | up(&bp->b_sema); | |
958 | XB_TRACE(bp, "unlock", 0); | |
1da177e4 LT |
959 | } |
960 | ||
961 | ||
962 | /* | |
963 | * Pinning Buffer Storage in Memory | |
ce8e922c | 964 | * Ensure that no attempt to force a buffer to disk will succeed. |
1da177e4 LT |
965 | */ |
966 | void | |
ce8e922c NS |
967 | xfs_buf_pin( |
968 | xfs_buf_t *bp) | |
1da177e4 | 969 | { |
ce8e922c NS |
970 | atomic_inc(&bp->b_pin_count); |
971 | XB_TRACE(bp, "pin", (long)bp->b_pin_count.counter); | |
1da177e4 LT |
972 | } |
973 | ||
1da177e4 | 974 | void |
ce8e922c NS |
975 | xfs_buf_unpin( |
976 | xfs_buf_t *bp) | |
1da177e4 | 977 | { |
ce8e922c NS |
978 | if (atomic_dec_and_test(&bp->b_pin_count)) |
979 | wake_up_all(&bp->b_waiters); | |
980 | XB_TRACE(bp, "unpin", (long)bp->b_pin_count.counter); | |
1da177e4 LT |
981 | } |
982 | ||
983 | int | |
ce8e922c NS |
984 | xfs_buf_ispin( |
985 | xfs_buf_t *bp) | |
1da177e4 | 986 | { |
ce8e922c | 987 | return atomic_read(&bp->b_pin_count); |
1da177e4 LT |
988 | } |
989 | ||
ce8e922c NS |
990 | STATIC void |
991 | xfs_buf_wait_unpin( | |
992 | xfs_buf_t *bp) | |
1da177e4 LT |
993 | { |
994 | DECLARE_WAITQUEUE (wait, current); | |
995 | ||
ce8e922c | 996 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
997 | return; |
998 | ||
ce8e922c | 999 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1000 | for (;;) { |
1001 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 1002 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 1003 | break; |
ce8e922c NS |
1004 | if (atomic_read(&bp->b_io_remaining)) |
1005 | blk_run_address_space(bp->b_target->bt_mapping); | |
1da177e4 LT |
1006 | schedule(); |
1007 | } | |
ce8e922c | 1008 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
1009 | set_current_state(TASK_RUNNING); |
1010 | } | |
1011 | ||
1012 | /* | |
1013 | * Buffer Utility Routines | |
1014 | */ | |
1015 | ||
1da177e4 | 1016 | STATIC void |
ce8e922c | 1017 | xfs_buf_iodone_work( |
c4028958 | 1018 | struct work_struct *work) |
1da177e4 | 1019 | { |
c4028958 DH |
1020 | xfs_buf_t *bp = |
1021 | container_of(work, xfs_buf_t, b_iodone_work); | |
1da177e4 | 1022 | |
0bfefc46 DC |
1023 | /* |
1024 | * We can get an EOPNOTSUPP to ordered writes. Here we clear the | |
1025 | * ordered flag and reissue them. Because we can't tell the higher | |
1026 | * layers directly that they should not issue ordered I/O anymore, they | |
73f6aa4d | 1027 | * need to check if the _XFS_BARRIER_FAILED flag was set during I/O completion. |
0bfefc46 DC |
1028 | */ |
1029 | if ((bp->b_error == EOPNOTSUPP) && | |
1030 | (bp->b_flags & (XBF_ORDERED|XBF_ASYNC)) == (XBF_ORDERED|XBF_ASYNC)) { | |
1031 | XB_TRACE(bp, "ordered_retry", bp->b_iodone); | |
1032 | bp->b_flags &= ~XBF_ORDERED; | |
73f6aa4d | 1033 | bp->b_flags |= _XFS_BARRIER_FAILED; |
0bfefc46 DC |
1034 | xfs_buf_iorequest(bp); |
1035 | } else if (bp->b_iodone) | |
ce8e922c NS |
1036 | (*(bp->b_iodone))(bp); |
1037 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 LT |
1038 | xfs_buf_relse(bp); |
1039 | } | |
1040 | ||
1041 | void | |
ce8e922c NS |
1042 | xfs_buf_ioend( |
1043 | xfs_buf_t *bp, | |
1da177e4 LT |
1044 | int schedule) |
1045 | { | |
77be55a5 | 1046 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); |
ce8e922c NS |
1047 | if (bp->b_error == 0) |
1048 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1049 | |
ce8e922c | 1050 | XB_TRACE(bp, "iodone", bp->b_iodone); |
1da177e4 | 1051 | |
ce8e922c | 1052 | if ((bp->b_iodone) || (bp->b_flags & XBF_ASYNC)) { |
1da177e4 | 1053 | if (schedule) { |
c4028958 | 1054 | INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work); |
ce8e922c | 1055 | queue_work(xfslogd_workqueue, &bp->b_iodone_work); |
1da177e4 | 1056 | } else { |
c4028958 | 1057 | xfs_buf_iodone_work(&bp->b_iodone_work); |
1da177e4 LT |
1058 | } |
1059 | } else { | |
b4dd330b | 1060 | complete(&bp->b_iowait); |
1da177e4 LT |
1061 | } |
1062 | } | |
1063 | ||
1da177e4 | 1064 | void |
ce8e922c NS |
1065 | xfs_buf_ioerror( |
1066 | xfs_buf_t *bp, | |
1067 | int error) | |
1da177e4 LT |
1068 | { |
1069 | ASSERT(error >= 0 && error <= 0xffff); | |
ce8e922c NS |
1070 | bp->b_error = (unsigned short)error; |
1071 | XB_TRACE(bp, "ioerror", (unsigned long)error); | |
1da177e4 LT |
1072 | } |
1073 | ||
1da177e4 | 1074 | int |
5d765b97 CH |
1075 | xfs_bawrite( |
1076 | void *mp, | |
1077 | struct xfs_buf *bp) | |
1da177e4 | 1078 | { |
5d765b97 | 1079 | XB_TRACE(bp, "bawrite", 0); |
1da177e4 | 1080 | |
5d765b97 | 1081 | ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL); |
1da177e4 | 1082 | |
5d765b97 | 1083 | xfs_buf_delwri_dequeue(bp); |
1da177e4 | 1084 | |
5d765b97 CH |
1085 | bp->b_flags &= ~(XBF_READ | XBF_DELWRI | XBF_READ_AHEAD); |
1086 | bp->b_flags |= (XBF_WRITE | XBF_ASYNC | _XBF_RUN_QUEUES); | |
1da177e4 | 1087 | |
15ac08a8 | 1088 | bp->b_mount = mp; |
5d765b97 CH |
1089 | bp->b_strat = xfs_bdstrat_cb; |
1090 | return xfs_bdstrat_cb(bp); | |
1091 | } | |
1da177e4 | 1092 | |
5d765b97 CH |
1093 | void |
1094 | xfs_bdwrite( | |
1095 | void *mp, | |
1096 | struct xfs_buf *bp) | |
1097 | { | |
1098 | XB_TRACE(bp, "bdwrite", 0); | |
1da177e4 | 1099 | |
5d765b97 | 1100 | bp->b_strat = xfs_bdstrat_cb; |
15ac08a8 | 1101 | bp->b_mount = mp; |
1da177e4 | 1102 | |
5d765b97 CH |
1103 | bp->b_flags &= ~XBF_READ; |
1104 | bp->b_flags |= (XBF_DELWRI | XBF_ASYNC); | |
1105 | ||
1106 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1107 | } |
1108 | ||
7989cb8e | 1109 | STATIC_INLINE void |
ce8e922c NS |
1110 | _xfs_buf_ioend( |
1111 | xfs_buf_t *bp, | |
1da177e4 LT |
1112 | int schedule) |
1113 | { | |
6ab455ee CH |
1114 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) { |
1115 | bp->b_flags &= ~_XBF_PAGE_LOCKED; | |
ce8e922c | 1116 | xfs_buf_ioend(bp, schedule); |
6ab455ee | 1117 | } |
1da177e4 LT |
1118 | } |
1119 | ||
782e3b3b | 1120 | STATIC void |
ce8e922c | 1121 | xfs_buf_bio_end_io( |
1da177e4 | 1122 | struct bio *bio, |
1da177e4 LT |
1123 | int error) |
1124 | { | |
ce8e922c NS |
1125 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1126 | unsigned int blocksize = bp->b_target->bt_bsize; | |
eedb5530 | 1127 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; |
1da177e4 | 1128 | |
cfbe5267 | 1129 | xfs_buf_ioerror(bp, -error); |
1da177e4 | 1130 | |
eedb5530 | 1131 | do { |
1da177e4 LT |
1132 | struct page *page = bvec->bv_page; |
1133 | ||
948ecdb4 | 1134 | ASSERT(!PagePrivate(page)); |
ce8e922c NS |
1135 | if (unlikely(bp->b_error)) { |
1136 | if (bp->b_flags & XBF_READ) | |
eedb5530 | 1137 | ClearPageUptodate(page); |
ce8e922c | 1138 | } else if (blocksize >= PAGE_CACHE_SIZE) { |
1da177e4 LT |
1139 | SetPageUptodate(page); |
1140 | } else if (!PagePrivate(page) && | |
ce8e922c | 1141 | (bp->b_flags & _XBF_PAGE_CACHE)) { |
1da177e4 LT |
1142 | set_page_region(page, bvec->bv_offset, bvec->bv_len); |
1143 | } | |
1144 | ||
eedb5530 NS |
1145 | if (--bvec >= bio->bi_io_vec) |
1146 | prefetchw(&bvec->bv_page->flags); | |
6ab455ee CH |
1147 | |
1148 | if (bp->b_flags & _XBF_PAGE_LOCKED) | |
1149 | unlock_page(page); | |
eedb5530 | 1150 | } while (bvec >= bio->bi_io_vec); |
1da177e4 | 1151 | |
ce8e922c | 1152 | _xfs_buf_ioend(bp, 1); |
1da177e4 | 1153 | bio_put(bio); |
1da177e4 LT |
1154 | } |
1155 | ||
1156 | STATIC void | |
ce8e922c NS |
1157 | _xfs_buf_ioapply( |
1158 | xfs_buf_t *bp) | |
1da177e4 | 1159 | { |
a9759f2d | 1160 | int rw, map_i, total_nr_pages, nr_pages; |
1da177e4 | 1161 | struct bio *bio; |
ce8e922c NS |
1162 | int offset = bp->b_offset; |
1163 | int size = bp->b_count_desired; | |
1164 | sector_t sector = bp->b_bn; | |
1165 | unsigned int blocksize = bp->b_target->bt_bsize; | |
1da177e4 | 1166 | |
ce8e922c | 1167 | total_nr_pages = bp->b_page_count; |
1da177e4 LT |
1168 | map_i = 0; |
1169 | ||
ce8e922c NS |
1170 | if (bp->b_flags & XBF_ORDERED) { |
1171 | ASSERT(!(bp->b_flags & XBF_READ)); | |
f538d4da | 1172 | rw = WRITE_BARRIER; |
51bdd706 NS |
1173 | } else if (bp->b_flags & _XBF_RUN_QUEUES) { |
1174 | ASSERT(!(bp->b_flags & XBF_READ_AHEAD)); | |
1175 | bp->b_flags &= ~_XBF_RUN_QUEUES; | |
1176 | rw = (bp->b_flags & XBF_WRITE) ? WRITE_SYNC : READ_SYNC; | |
1177 | } else { | |
1178 | rw = (bp->b_flags & XBF_WRITE) ? WRITE : | |
1179 | (bp->b_flags & XBF_READ_AHEAD) ? READA : READ; | |
f538d4da CH |
1180 | } |
1181 | ||
ce8e922c | 1182 | /* Special code path for reading a sub page size buffer in -- |
1da177e4 LT |
1183 | * we populate up the whole page, and hence the other metadata |
1184 | * in the same page. This optimization is only valid when the | |
ce8e922c | 1185 | * filesystem block size is not smaller than the page size. |
1da177e4 | 1186 | */ |
ce8e922c | 1187 | if ((bp->b_buffer_length < PAGE_CACHE_SIZE) && |
6ab455ee CH |
1188 | ((bp->b_flags & (XBF_READ|_XBF_PAGE_LOCKED)) == |
1189 | (XBF_READ|_XBF_PAGE_LOCKED)) && | |
ce8e922c | 1190 | (blocksize >= PAGE_CACHE_SIZE)) { |
1da177e4 LT |
1191 | bio = bio_alloc(GFP_NOIO, 1); |
1192 | ||
ce8e922c | 1193 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1194 | bio->bi_sector = sector - (offset >> BBSHIFT); |
ce8e922c NS |
1195 | bio->bi_end_io = xfs_buf_bio_end_io; |
1196 | bio->bi_private = bp; | |
1da177e4 | 1197 | |
ce8e922c | 1198 | bio_add_page(bio, bp->b_pages[0], PAGE_CACHE_SIZE, 0); |
1da177e4 LT |
1199 | size = 0; |
1200 | ||
ce8e922c | 1201 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1202 | |
1203 | goto submit_io; | |
1204 | } | |
1205 | ||
1da177e4 | 1206 | next_chunk: |
ce8e922c | 1207 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1208 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1209 | if (nr_pages > total_nr_pages) | |
1210 | nr_pages = total_nr_pages; | |
1211 | ||
1212 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1213 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1214 | bio->bi_sector = sector; |
ce8e922c NS |
1215 | bio->bi_end_io = xfs_buf_bio_end_io; |
1216 | bio->bi_private = bp; | |
1da177e4 LT |
1217 | |
1218 | for (; size && nr_pages; nr_pages--, map_i++) { | |
ce8e922c | 1219 | int rbytes, nbytes = PAGE_CACHE_SIZE - offset; |
1da177e4 LT |
1220 | |
1221 | if (nbytes > size) | |
1222 | nbytes = size; | |
1223 | ||
ce8e922c NS |
1224 | rbytes = bio_add_page(bio, bp->b_pages[map_i], nbytes, offset); |
1225 | if (rbytes < nbytes) | |
1da177e4 LT |
1226 | break; |
1227 | ||
1228 | offset = 0; | |
1229 | sector += nbytes >> BBSHIFT; | |
1230 | size -= nbytes; | |
1231 | total_nr_pages--; | |
1232 | } | |
1233 | ||
1234 | submit_io: | |
1235 | if (likely(bio->bi_size)) { | |
1236 | submit_bio(rw, bio); | |
1237 | if (size) | |
1238 | goto next_chunk; | |
1239 | } else { | |
1240 | bio_put(bio); | |
ce8e922c | 1241 | xfs_buf_ioerror(bp, EIO); |
1da177e4 LT |
1242 | } |
1243 | } | |
1244 | ||
1da177e4 | 1245 | int |
ce8e922c NS |
1246 | xfs_buf_iorequest( |
1247 | xfs_buf_t *bp) | |
1da177e4 | 1248 | { |
ce8e922c | 1249 | XB_TRACE(bp, "iorequest", 0); |
1da177e4 | 1250 | |
ce8e922c NS |
1251 | if (bp->b_flags & XBF_DELWRI) { |
1252 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1253 | return 0; |
1254 | } | |
1255 | ||
ce8e922c NS |
1256 | if (bp->b_flags & XBF_WRITE) { |
1257 | xfs_buf_wait_unpin(bp); | |
1da177e4 LT |
1258 | } |
1259 | ||
ce8e922c | 1260 | xfs_buf_hold(bp); |
1da177e4 LT |
1261 | |
1262 | /* Set the count to 1 initially, this will stop an I/O | |
1263 | * completion callout which happens before we have started | |
ce8e922c | 1264 | * all the I/O from calling xfs_buf_ioend too early. |
1da177e4 | 1265 | */ |
ce8e922c NS |
1266 | atomic_set(&bp->b_io_remaining, 1); |
1267 | _xfs_buf_ioapply(bp); | |
1268 | _xfs_buf_ioend(bp, 0); | |
1da177e4 | 1269 | |
ce8e922c | 1270 | xfs_buf_rele(bp); |
1da177e4 LT |
1271 | return 0; |
1272 | } | |
1273 | ||
1274 | /* | |
ce8e922c NS |
1275 | * Waits for I/O to complete on the buffer supplied. |
1276 | * It returns immediately if no I/O is pending. | |
1277 | * It returns the I/O error code, if any, or 0 if there was no error. | |
1da177e4 LT |
1278 | */ |
1279 | int | |
ce8e922c NS |
1280 | xfs_buf_iowait( |
1281 | xfs_buf_t *bp) | |
1da177e4 | 1282 | { |
ce8e922c NS |
1283 | XB_TRACE(bp, "iowait", 0); |
1284 | if (atomic_read(&bp->b_io_remaining)) | |
1285 | blk_run_address_space(bp->b_target->bt_mapping); | |
b4dd330b | 1286 | wait_for_completion(&bp->b_iowait); |
ce8e922c NS |
1287 | XB_TRACE(bp, "iowaited", (long)bp->b_error); |
1288 | return bp->b_error; | |
1da177e4 LT |
1289 | } |
1290 | ||
ce8e922c NS |
1291 | xfs_caddr_t |
1292 | xfs_buf_offset( | |
1293 | xfs_buf_t *bp, | |
1da177e4 LT |
1294 | size_t offset) |
1295 | { | |
1296 | struct page *page; | |
1297 | ||
ce8e922c NS |
1298 | if (bp->b_flags & XBF_MAPPED) |
1299 | return XFS_BUF_PTR(bp) + offset; | |
1da177e4 | 1300 | |
ce8e922c NS |
1301 | offset += bp->b_offset; |
1302 | page = bp->b_pages[offset >> PAGE_CACHE_SHIFT]; | |
1303 | return (xfs_caddr_t)page_address(page) + (offset & (PAGE_CACHE_SIZE-1)); | |
1da177e4 LT |
1304 | } |
1305 | ||
1306 | /* | |
1da177e4 LT |
1307 | * Move data into or out of a buffer. |
1308 | */ | |
1309 | void | |
ce8e922c NS |
1310 | xfs_buf_iomove( |
1311 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1312 | size_t boff, /* starting buffer offset */ |
1313 | size_t bsize, /* length to copy */ | |
1314 | caddr_t data, /* data address */ | |
ce8e922c | 1315 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 LT |
1316 | { |
1317 | size_t bend, cpoff, csize; | |
1318 | struct page *page; | |
1319 | ||
1320 | bend = boff + bsize; | |
1321 | while (boff < bend) { | |
ce8e922c NS |
1322 | page = bp->b_pages[xfs_buf_btoct(boff + bp->b_offset)]; |
1323 | cpoff = xfs_buf_poff(boff + bp->b_offset); | |
1da177e4 | 1324 | csize = min_t(size_t, |
ce8e922c | 1325 | PAGE_CACHE_SIZE-cpoff, bp->b_count_desired-boff); |
1da177e4 LT |
1326 | |
1327 | ASSERT(((csize + cpoff) <= PAGE_CACHE_SIZE)); | |
1328 | ||
1329 | switch (mode) { | |
ce8e922c | 1330 | case XBRW_ZERO: |
1da177e4 LT |
1331 | memset(page_address(page) + cpoff, 0, csize); |
1332 | break; | |
ce8e922c | 1333 | case XBRW_READ: |
1da177e4 LT |
1334 | memcpy(data, page_address(page) + cpoff, csize); |
1335 | break; | |
ce8e922c | 1336 | case XBRW_WRITE: |
1da177e4 LT |
1337 | memcpy(page_address(page) + cpoff, data, csize); |
1338 | } | |
1339 | ||
1340 | boff += csize; | |
1341 | data += csize; | |
1342 | } | |
1343 | } | |
1344 | ||
1345 | /* | |
ce8e922c | 1346 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1347 | */ |
1348 | ||
1349 | /* | |
ce8e922c NS |
1350 | * Wait for any bufs with callbacks that have been submitted but |
1351 | * have not yet returned... walk the hash list for the target. | |
1da177e4 LT |
1352 | */ |
1353 | void | |
1354 | xfs_wait_buftarg( | |
1355 | xfs_buftarg_t *btp) | |
1356 | { | |
1357 | xfs_buf_t *bp, *n; | |
1358 | xfs_bufhash_t *hash; | |
1359 | uint i; | |
1360 | ||
1361 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { | |
1362 | hash = &btp->bt_hash[i]; | |
1363 | again: | |
1364 | spin_lock(&hash->bh_lock); | |
ce8e922c NS |
1365 | list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) { |
1366 | ASSERT(btp == bp->b_target); | |
1367 | if (!(bp->b_flags & XBF_FS_MANAGED)) { | |
1da177e4 | 1368 | spin_unlock(&hash->bh_lock); |
2f926587 DC |
1369 | /* |
1370 | * Catch superblock reference count leaks | |
1371 | * immediately | |
1372 | */ | |
ce8e922c | 1373 | BUG_ON(bp->b_bn == 0); |
1da177e4 LT |
1374 | delay(100); |
1375 | goto again; | |
1376 | } | |
1377 | } | |
1378 | spin_unlock(&hash->bh_lock); | |
1379 | } | |
1380 | } | |
1381 | ||
1382 | /* | |
ce8e922c NS |
1383 | * Allocate buffer hash table for a given target. |
1384 | * For devices containing metadata (i.e. not the log/realtime devices) | |
1385 | * we need to allocate a much larger hash table. | |
1da177e4 LT |
1386 | */ |
1387 | STATIC void | |
1388 | xfs_alloc_bufhash( | |
1389 | xfs_buftarg_t *btp, | |
1390 | int external) | |
1391 | { | |
1392 | unsigned int i; | |
1393 | ||
1394 | btp->bt_hashshift = external ? 3 : 8; /* 8 or 256 buckets */ | |
1395 | btp->bt_hashmask = (1 << btp->bt_hashshift) - 1; | |
1396 | btp->bt_hash = kmem_zalloc((1 << btp->bt_hashshift) * | |
93c189c1 | 1397 | sizeof(xfs_bufhash_t), KM_SLEEP | KM_LARGE); |
1da177e4 LT |
1398 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { |
1399 | spin_lock_init(&btp->bt_hash[i].bh_lock); | |
1400 | INIT_LIST_HEAD(&btp->bt_hash[i].bh_list); | |
1401 | } | |
1402 | } | |
1403 | ||
1404 | STATIC void | |
1405 | xfs_free_bufhash( | |
1406 | xfs_buftarg_t *btp) | |
1407 | { | |
f0e2d93c | 1408 | kmem_free(btp->bt_hash); |
1da177e4 LT |
1409 | btp->bt_hash = NULL; |
1410 | } | |
1411 | ||
a6867a68 | 1412 | /* |
ce8e922c | 1413 | * buftarg list for delwrite queue processing |
a6867a68 | 1414 | */ |
e6a0e9cd | 1415 | static LIST_HEAD(xfs_buftarg_list); |
7989cb8e | 1416 | static DEFINE_SPINLOCK(xfs_buftarg_lock); |
a6867a68 DC |
1417 | |
1418 | STATIC void | |
1419 | xfs_register_buftarg( | |
1420 | xfs_buftarg_t *btp) | |
1421 | { | |
1422 | spin_lock(&xfs_buftarg_lock); | |
1423 | list_add(&btp->bt_list, &xfs_buftarg_list); | |
1424 | spin_unlock(&xfs_buftarg_lock); | |
1425 | } | |
1426 | ||
1427 | STATIC void | |
1428 | xfs_unregister_buftarg( | |
1429 | xfs_buftarg_t *btp) | |
1430 | { | |
1431 | spin_lock(&xfs_buftarg_lock); | |
1432 | list_del(&btp->bt_list); | |
1433 | spin_unlock(&xfs_buftarg_lock); | |
1434 | } | |
1435 | ||
1da177e4 LT |
1436 | void |
1437 | xfs_free_buftarg( | |
19f354d4 | 1438 | xfs_buftarg_t *btp) |
1da177e4 LT |
1439 | { |
1440 | xfs_flush_buftarg(btp, 1); | |
f4a9f28a | 1441 | xfs_blkdev_issue_flush(btp); |
1da177e4 | 1442 | xfs_free_bufhash(btp); |
ce8e922c | 1443 | iput(btp->bt_mapping->host); |
a6867a68 | 1444 | |
ce8e922c NS |
1445 | /* Unregister the buftarg first so that we don't get a |
1446 | * wakeup finding a non-existent task | |
1447 | */ | |
a6867a68 DC |
1448 | xfs_unregister_buftarg(btp); |
1449 | kthread_stop(btp->bt_task); | |
1450 | ||
f0e2d93c | 1451 | kmem_free(btp); |
1da177e4 LT |
1452 | } |
1453 | ||
1da177e4 LT |
1454 | STATIC int |
1455 | xfs_setsize_buftarg_flags( | |
1456 | xfs_buftarg_t *btp, | |
1457 | unsigned int blocksize, | |
1458 | unsigned int sectorsize, | |
1459 | int verbose) | |
1460 | { | |
ce8e922c NS |
1461 | btp->bt_bsize = blocksize; |
1462 | btp->bt_sshift = ffs(sectorsize) - 1; | |
1463 | btp->bt_smask = sectorsize - 1; | |
1da177e4 | 1464 | |
ce8e922c | 1465 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
1da177e4 LT |
1466 | printk(KERN_WARNING |
1467 | "XFS: Cannot set_blocksize to %u on device %s\n", | |
1468 | sectorsize, XFS_BUFTARG_NAME(btp)); | |
1469 | return EINVAL; | |
1470 | } | |
1471 | ||
1472 | if (verbose && | |
1473 | (PAGE_CACHE_SIZE / BITS_PER_LONG) > sectorsize) { | |
1474 | printk(KERN_WARNING | |
1475 | "XFS: %u byte sectors in use on device %s. " | |
1476 | "This is suboptimal; %u or greater is ideal.\n", | |
1477 | sectorsize, XFS_BUFTARG_NAME(btp), | |
1478 | (unsigned int)PAGE_CACHE_SIZE / BITS_PER_LONG); | |
1479 | } | |
1480 | ||
1481 | return 0; | |
1482 | } | |
1483 | ||
1484 | /* | |
ce8e922c NS |
1485 | * When allocating the initial buffer target we have not yet |
1486 | * read in the superblock, so don't know what sized sectors | |
1487 | * are being used is at this early stage. Play safe. | |
1488 | */ | |
1da177e4 LT |
1489 | STATIC int |
1490 | xfs_setsize_buftarg_early( | |
1491 | xfs_buftarg_t *btp, | |
1492 | struct block_device *bdev) | |
1493 | { | |
1494 | return xfs_setsize_buftarg_flags(btp, | |
1495 | PAGE_CACHE_SIZE, bdev_hardsect_size(bdev), 0); | |
1496 | } | |
1497 | ||
1498 | int | |
1499 | xfs_setsize_buftarg( | |
1500 | xfs_buftarg_t *btp, | |
1501 | unsigned int blocksize, | |
1502 | unsigned int sectorsize) | |
1503 | { | |
1504 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | |
1505 | } | |
1506 | ||
1507 | STATIC int | |
1508 | xfs_mapping_buftarg( | |
1509 | xfs_buftarg_t *btp, | |
1510 | struct block_device *bdev) | |
1511 | { | |
1512 | struct backing_dev_info *bdi; | |
1513 | struct inode *inode; | |
1514 | struct address_space *mapping; | |
f5e54d6e | 1515 | static const struct address_space_operations mapping_aops = { |
1da177e4 | 1516 | .sync_page = block_sync_page, |
e965f963 | 1517 | .migratepage = fail_migrate_page, |
1da177e4 LT |
1518 | }; |
1519 | ||
1520 | inode = new_inode(bdev->bd_inode->i_sb); | |
1521 | if (!inode) { | |
1522 | printk(KERN_WARNING | |
1523 | "XFS: Cannot allocate mapping inode for device %s\n", | |
1524 | XFS_BUFTARG_NAME(btp)); | |
1525 | return ENOMEM; | |
1526 | } | |
1527 | inode->i_mode = S_IFBLK; | |
1528 | inode->i_bdev = bdev; | |
1529 | inode->i_rdev = bdev->bd_dev; | |
1530 | bdi = blk_get_backing_dev_info(bdev); | |
1531 | if (!bdi) | |
1532 | bdi = &default_backing_dev_info; | |
1533 | mapping = &inode->i_data; | |
1534 | mapping->a_ops = &mapping_aops; | |
1535 | mapping->backing_dev_info = bdi; | |
1536 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
ce8e922c | 1537 | btp->bt_mapping = mapping; |
1da177e4 LT |
1538 | return 0; |
1539 | } | |
1540 | ||
a6867a68 DC |
1541 | STATIC int |
1542 | xfs_alloc_delwrite_queue( | |
1543 | xfs_buftarg_t *btp) | |
1544 | { | |
1545 | int error = 0; | |
1546 | ||
1547 | INIT_LIST_HEAD(&btp->bt_list); | |
1548 | INIT_LIST_HEAD(&btp->bt_delwrite_queue); | |
007c61c6 | 1549 | spin_lock_init(&btp->bt_delwrite_lock); |
a6867a68 DC |
1550 | btp->bt_flags = 0; |
1551 | btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd"); | |
1552 | if (IS_ERR(btp->bt_task)) { | |
1553 | error = PTR_ERR(btp->bt_task); | |
1554 | goto out_error; | |
1555 | } | |
1556 | xfs_register_buftarg(btp); | |
1557 | out_error: | |
1558 | return error; | |
1559 | } | |
1560 | ||
1da177e4 LT |
1561 | xfs_buftarg_t * |
1562 | xfs_alloc_buftarg( | |
1563 | struct block_device *bdev, | |
1564 | int external) | |
1565 | { | |
1566 | xfs_buftarg_t *btp; | |
1567 | ||
1568 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP); | |
1569 | ||
ce8e922c NS |
1570 | btp->bt_dev = bdev->bd_dev; |
1571 | btp->bt_bdev = bdev; | |
1da177e4 LT |
1572 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1573 | goto error; | |
1574 | if (xfs_mapping_buftarg(btp, bdev)) | |
1575 | goto error; | |
a6867a68 DC |
1576 | if (xfs_alloc_delwrite_queue(btp)) |
1577 | goto error; | |
1da177e4 LT |
1578 | xfs_alloc_bufhash(btp, external); |
1579 | return btp; | |
1580 | ||
1581 | error: | |
f0e2d93c | 1582 | kmem_free(btp); |
1da177e4 LT |
1583 | return NULL; |
1584 | } | |
1585 | ||
1586 | ||
1587 | /* | |
ce8e922c | 1588 | * Delayed write buffer handling |
1da177e4 | 1589 | */ |
1da177e4 | 1590 | STATIC void |
ce8e922c NS |
1591 | xfs_buf_delwri_queue( |
1592 | xfs_buf_t *bp, | |
1da177e4 LT |
1593 | int unlock) |
1594 | { | |
ce8e922c NS |
1595 | struct list_head *dwq = &bp->b_target->bt_delwrite_queue; |
1596 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; | |
a6867a68 | 1597 | |
ce8e922c NS |
1598 | XB_TRACE(bp, "delwri_q", (long)unlock); |
1599 | ASSERT((bp->b_flags&(XBF_DELWRI|XBF_ASYNC)) == (XBF_DELWRI|XBF_ASYNC)); | |
1da177e4 | 1600 | |
a6867a68 | 1601 | spin_lock(dwlk); |
1da177e4 | 1602 | /* If already in the queue, dequeue and place at tail */ |
ce8e922c NS |
1603 | if (!list_empty(&bp->b_list)) { |
1604 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1605 | if (unlock) | |
1606 | atomic_dec(&bp->b_hold); | |
1607 | list_del(&bp->b_list); | |
1da177e4 LT |
1608 | } |
1609 | ||
ce8e922c NS |
1610 | bp->b_flags |= _XBF_DELWRI_Q; |
1611 | list_add_tail(&bp->b_list, dwq); | |
1612 | bp->b_queuetime = jiffies; | |
a6867a68 | 1613 | spin_unlock(dwlk); |
1da177e4 LT |
1614 | |
1615 | if (unlock) | |
ce8e922c | 1616 | xfs_buf_unlock(bp); |
1da177e4 LT |
1617 | } |
1618 | ||
1619 | void | |
ce8e922c NS |
1620 | xfs_buf_delwri_dequeue( |
1621 | xfs_buf_t *bp) | |
1da177e4 | 1622 | { |
ce8e922c | 1623 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; |
1da177e4 LT |
1624 | int dequeued = 0; |
1625 | ||
a6867a68 | 1626 | spin_lock(dwlk); |
ce8e922c NS |
1627 | if ((bp->b_flags & XBF_DELWRI) && !list_empty(&bp->b_list)) { |
1628 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1629 | list_del_init(&bp->b_list); | |
1da177e4 LT |
1630 | dequeued = 1; |
1631 | } | |
ce8e922c | 1632 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); |
a6867a68 | 1633 | spin_unlock(dwlk); |
1da177e4 LT |
1634 | |
1635 | if (dequeued) | |
ce8e922c | 1636 | xfs_buf_rele(bp); |
1da177e4 | 1637 | |
ce8e922c | 1638 | XB_TRACE(bp, "delwri_dq", (long)dequeued); |
1da177e4 LT |
1639 | } |
1640 | ||
1641 | STATIC void | |
ce8e922c | 1642 | xfs_buf_runall_queues( |
1da177e4 LT |
1643 | struct workqueue_struct *queue) |
1644 | { | |
1645 | flush_workqueue(queue); | |
1646 | } | |
1647 | ||
1da177e4 | 1648 | STATIC int |
23ea4032 | 1649 | xfsbufd_wakeup( |
15c84a47 NS |
1650 | int priority, |
1651 | gfp_t mask) | |
1da177e4 | 1652 | { |
da7f93e9 | 1653 | xfs_buftarg_t *btp; |
a6867a68 DC |
1654 | |
1655 | spin_lock(&xfs_buftarg_lock); | |
da7f93e9 | 1656 | list_for_each_entry(btp, &xfs_buftarg_list, bt_list) { |
ce8e922c | 1657 | if (test_bit(XBT_FORCE_SLEEP, &btp->bt_flags)) |
a6867a68 | 1658 | continue; |
ce8e922c | 1659 | set_bit(XBT_FORCE_FLUSH, &btp->bt_flags); |
a6867a68 DC |
1660 | wake_up_process(btp->bt_task); |
1661 | } | |
1662 | spin_unlock(&xfs_buftarg_lock); | |
1da177e4 LT |
1663 | return 0; |
1664 | } | |
1665 | ||
585e6d88 DC |
1666 | /* |
1667 | * Move as many buffers as specified to the supplied list | |
1668 | * idicating if we skipped any buffers to prevent deadlocks. | |
1669 | */ | |
1670 | STATIC int | |
1671 | xfs_buf_delwri_split( | |
1672 | xfs_buftarg_t *target, | |
1673 | struct list_head *list, | |
5e6a07df | 1674 | unsigned long age) |
585e6d88 DC |
1675 | { |
1676 | xfs_buf_t *bp, *n; | |
1677 | struct list_head *dwq = &target->bt_delwrite_queue; | |
1678 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1679 | int skipped = 0; | |
5e6a07df | 1680 | int force; |
585e6d88 | 1681 | |
5e6a07df | 1682 | force = test_and_clear_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
585e6d88 DC |
1683 | INIT_LIST_HEAD(list); |
1684 | spin_lock(dwlk); | |
1685 | list_for_each_entry_safe(bp, n, dwq, b_list) { | |
1686 | XB_TRACE(bp, "walkq1", (long)xfs_buf_ispin(bp)); | |
1687 | ASSERT(bp->b_flags & XBF_DELWRI); | |
1688 | ||
1689 | if (!xfs_buf_ispin(bp) && !xfs_buf_cond_lock(bp)) { | |
5e6a07df | 1690 | if (!force && |
585e6d88 DC |
1691 | time_before(jiffies, bp->b_queuetime + age)) { |
1692 | xfs_buf_unlock(bp); | |
1693 | break; | |
1694 | } | |
1695 | ||
1696 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q| | |
1697 | _XBF_RUN_QUEUES); | |
1698 | bp->b_flags |= XBF_WRITE; | |
1699 | list_move_tail(&bp->b_list, list); | |
1700 | } else | |
1701 | skipped++; | |
1702 | } | |
1703 | spin_unlock(dwlk); | |
1704 | ||
1705 | return skipped; | |
1706 | ||
1707 | } | |
1708 | ||
1da177e4 | 1709 | STATIC int |
23ea4032 | 1710 | xfsbufd( |
585e6d88 | 1711 | void *data) |
1da177e4 | 1712 | { |
585e6d88 DC |
1713 | struct list_head tmp; |
1714 | xfs_buftarg_t *target = (xfs_buftarg_t *)data; | |
1715 | int count; | |
1716 | xfs_buf_t *bp; | |
1da177e4 | 1717 | |
1da177e4 LT |
1718 | current->flags |= PF_MEMALLOC; |
1719 | ||
978c7b2f RW |
1720 | set_freezable(); |
1721 | ||
1da177e4 | 1722 | do { |
3e1d1d28 | 1723 | if (unlikely(freezing(current))) { |
ce8e922c | 1724 | set_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
3e1d1d28 | 1725 | refrigerator(); |
abd0cf7a | 1726 | } else { |
ce8e922c | 1727 | clear_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
abd0cf7a | 1728 | } |
1da177e4 | 1729 | |
15c84a47 NS |
1730 | schedule_timeout_interruptible( |
1731 | xfs_buf_timer_centisecs * msecs_to_jiffies(10)); | |
1da177e4 | 1732 | |
585e6d88 | 1733 | xfs_buf_delwri_split(target, &tmp, |
5e6a07df | 1734 | xfs_buf_age_centisecs * msecs_to_jiffies(10)); |
1da177e4 | 1735 | |
585e6d88 | 1736 | count = 0; |
1da177e4 | 1737 | while (!list_empty(&tmp)) { |
ce8e922c NS |
1738 | bp = list_entry(tmp.next, xfs_buf_t, b_list); |
1739 | ASSERT(target == bp->b_target); | |
1da177e4 | 1740 | |
ce8e922c NS |
1741 | list_del_init(&bp->b_list); |
1742 | xfs_buf_iostrategy(bp); | |
585e6d88 | 1743 | count++; |
1da177e4 LT |
1744 | } |
1745 | ||
27e88bf6 FB |
1746 | if (as_list_len > 0) |
1747 | purge_addresses(); | |
f07c2250 NS |
1748 | if (count) |
1749 | blk_run_address_space(target->bt_mapping); | |
1da177e4 | 1750 | |
4df08c52 | 1751 | } while (!kthread_should_stop()); |
1da177e4 | 1752 | |
4df08c52 | 1753 | return 0; |
1da177e4 LT |
1754 | } |
1755 | ||
1756 | /* | |
ce8e922c NS |
1757 | * Go through all incore buffers, and release buffers if they belong to |
1758 | * the given device. This is used in filesystem error handling to | |
1759 | * preserve the consistency of its metadata. | |
1da177e4 LT |
1760 | */ |
1761 | int | |
1762 | xfs_flush_buftarg( | |
585e6d88 DC |
1763 | xfs_buftarg_t *target, |
1764 | int wait) | |
1da177e4 | 1765 | { |
585e6d88 DC |
1766 | struct list_head tmp; |
1767 | xfs_buf_t *bp, *n; | |
1768 | int pincount = 0; | |
1da177e4 | 1769 | |
ce8e922c NS |
1770 | xfs_buf_runall_queues(xfsdatad_workqueue); |
1771 | xfs_buf_runall_queues(xfslogd_workqueue); | |
1da177e4 | 1772 | |
5e6a07df DC |
1773 | set_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
1774 | pincount = xfs_buf_delwri_split(target, &tmp, 0); | |
1da177e4 LT |
1775 | |
1776 | /* | |
1777 | * Dropped the delayed write list lock, now walk the temporary list | |
1778 | */ | |
ce8e922c | 1779 | list_for_each_entry_safe(bp, n, &tmp, b_list) { |
585e6d88 | 1780 | ASSERT(target == bp->b_target); |
1da177e4 | 1781 | if (wait) |
ce8e922c | 1782 | bp->b_flags &= ~XBF_ASYNC; |
1da177e4 | 1783 | else |
ce8e922c | 1784 | list_del_init(&bp->b_list); |
1da177e4 | 1785 | |
ce8e922c | 1786 | xfs_buf_iostrategy(bp); |
1da177e4 LT |
1787 | } |
1788 | ||
f07c2250 NS |
1789 | if (wait) |
1790 | blk_run_address_space(target->bt_mapping); | |
1791 | ||
1da177e4 LT |
1792 | /* |
1793 | * Remaining list items must be flushed before returning | |
1794 | */ | |
1795 | while (!list_empty(&tmp)) { | |
ce8e922c | 1796 | bp = list_entry(tmp.next, xfs_buf_t, b_list); |
1da177e4 | 1797 | |
ce8e922c NS |
1798 | list_del_init(&bp->b_list); |
1799 | xfs_iowait(bp); | |
1800 | xfs_buf_relse(bp); | |
1da177e4 LT |
1801 | } |
1802 | ||
1da177e4 LT |
1803 | return pincount; |
1804 | } | |
1805 | ||
04d8b284 | 1806 | int __init |
ce8e922c | 1807 | xfs_buf_init(void) |
1da177e4 | 1808 | { |
ce8e922c | 1809 | #ifdef XFS_BUF_TRACE |
5695ef46 | 1810 | xfs_buf_trace_buf = ktrace_alloc(XFS_BUF_TRACE_SIZE, KM_NOFS); |
04d8b284 CH |
1811 | #endif |
1812 | ||
8758280f NS |
1813 | xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf", |
1814 | KM_ZONE_HWALIGN, NULL); | |
ce8e922c | 1815 | if (!xfs_buf_zone) |
04d8b284 CH |
1816 | goto out_free_trace_buf; |
1817 | ||
b4337692 | 1818 | xfslogd_workqueue = create_workqueue("xfslogd"); |
23ea4032 | 1819 | if (!xfslogd_workqueue) |
04d8b284 | 1820 | goto out_free_buf_zone; |
1da177e4 | 1821 | |
b4337692 | 1822 | xfsdatad_workqueue = create_workqueue("xfsdatad"); |
23ea4032 CH |
1823 | if (!xfsdatad_workqueue) |
1824 | goto out_destroy_xfslogd_workqueue; | |
1da177e4 | 1825 | |
8e1f936b | 1826 | register_shrinker(&xfs_buf_shake); |
23ea4032 | 1827 | return 0; |
1da177e4 | 1828 | |
23ea4032 CH |
1829 | out_destroy_xfslogd_workqueue: |
1830 | destroy_workqueue(xfslogd_workqueue); | |
23ea4032 | 1831 | out_free_buf_zone: |
ce8e922c | 1832 | kmem_zone_destroy(xfs_buf_zone); |
04d8b284 | 1833 | out_free_trace_buf: |
ce8e922c NS |
1834 | #ifdef XFS_BUF_TRACE |
1835 | ktrace_free(xfs_buf_trace_buf); | |
23ea4032 | 1836 | #endif |
8758280f | 1837 | return -ENOMEM; |
1da177e4 LT |
1838 | } |
1839 | ||
1da177e4 | 1840 | void |
ce8e922c | 1841 | xfs_buf_terminate(void) |
1da177e4 | 1842 | { |
8e1f936b | 1843 | unregister_shrinker(&xfs_buf_shake); |
04d8b284 CH |
1844 | destroy_workqueue(xfsdatad_workqueue); |
1845 | destroy_workqueue(xfslogd_workqueue); | |
ce8e922c NS |
1846 | kmem_zone_destroy(xfs_buf_zone); |
1847 | #ifdef XFS_BUF_TRACE | |
1848 | ktrace_free(xfs_buf_trace_buf); | |
1da177e4 | 1849 | #endif |
1da177e4 | 1850 | } |
e6a0e9cd TS |
1851 | |
1852 | #ifdef CONFIG_KDB_MODULES | |
1853 | struct list_head * | |
1854 | xfs_get_buftarg_list(void) | |
1855 | { | |
1856 | return &xfs_buftarg_list; | |
1857 | } | |
1858 | #endif |