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Commit | Line | Data |
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1da177e4 | 1 | /* |
7b718769 NS |
2 | * Copyright (c) 2000-2005 Silicon Graphics, Inc. |
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 | */ |
1da177e4 LT |
18 | #include <linux/stddef.h> |
19 | #include <linux/errno.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/pagemap.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/vmalloc.h> | |
24 | #include <linux/bio.h> | |
25 | #include <linux/sysctl.h> | |
26 | #include <linux/proc_fs.h> | |
27 | #include <linux/workqueue.h> | |
28 | #include <linux/percpu.h> | |
29 | #include <linux/blkdev.h> | |
30 | #include <linux/hash.h> | |
4df08c52 | 31 | #include <linux/kthread.h> |
b20a3503 | 32 | #include <linux/migrate.h> |
1da177e4 LT |
33 | #include "xfs_linux.h" |
34 | ||
ce8e922c NS |
35 | STATIC kmem_zone_t *xfs_buf_zone; |
36 | STATIC kmem_shaker_t xfs_buf_shake; | |
a6867a68 | 37 | STATIC int xfsbufd(void *); |
27496a8c | 38 | STATIC int xfsbufd_wakeup(int, gfp_t); |
ce8e922c | 39 | STATIC void xfs_buf_delwri_queue(xfs_buf_t *, int); |
23ea4032 CH |
40 | |
41 | STATIC struct workqueue_struct *xfslogd_workqueue; | |
0829c360 | 42 | struct workqueue_struct *xfsdatad_workqueue; |
1da177e4 | 43 | |
ce8e922c | 44 | #ifdef XFS_BUF_TRACE |
1da177e4 | 45 | void |
ce8e922c NS |
46 | xfs_buf_trace( |
47 | xfs_buf_t *bp, | |
1da177e4 LT |
48 | char *id, |
49 | void *data, | |
50 | void *ra) | |
51 | { | |
ce8e922c NS |
52 | ktrace_enter(xfs_buf_trace_buf, |
53 | bp, id, | |
54 | (void *)(unsigned long)bp->b_flags, | |
55 | (void *)(unsigned long)bp->b_hold.counter, | |
56 | (void *)(unsigned long)bp->b_sema.count.counter, | |
1da177e4 LT |
57 | (void *)current, |
58 | data, ra, | |
ce8e922c NS |
59 | (void *)(unsigned long)((bp->b_file_offset>>32) & 0xffffffff), |
60 | (void *)(unsigned long)(bp->b_file_offset & 0xffffffff), | |
61 | (void *)(unsigned long)bp->b_buffer_length, | |
1da177e4 LT |
62 | NULL, NULL, NULL, NULL, NULL); |
63 | } | |
ce8e922c NS |
64 | ktrace_t *xfs_buf_trace_buf; |
65 | #define XFS_BUF_TRACE_SIZE 4096 | |
66 | #define XB_TRACE(bp, id, data) \ | |
67 | xfs_buf_trace(bp, id, (void *)data, (void *)__builtin_return_address(0)) | |
1da177e4 | 68 | #else |
ce8e922c | 69 | #define XB_TRACE(bp, id, data) do { } while (0) |
1da177e4 LT |
70 | #endif |
71 | ||
ce8e922c NS |
72 | #ifdef XFS_BUF_LOCK_TRACKING |
73 | # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid) | |
74 | # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1) | |
75 | # define XB_GET_OWNER(bp) ((bp)->b_last_holder) | |
1da177e4 | 76 | #else |
ce8e922c NS |
77 | # define XB_SET_OWNER(bp) do { } while (0) |
78 | # define XB_CLEAR_OWNER(bp) do { } while (0) | |
79 | # define XB_GET_OWNER(bp) do { } while (0) | |
1da177e4 LT |
80 | #endif |
81 | ||
ce8e922c NS |
82 | #define xb_to_gfp(flags) \ |
83 | ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : \ | |
84 | ((flags) & XBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN) | |
1da177e4 | 85 | |
ce8e922c NS |
86 | #define xb_to_km(flags) \ |
87 | (((flags) & XBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP) | |
1da177e4 | 88 | |
ce8e922c NS |
89 | #define xfs_buf_allocate(flags) \ |
90 | kmem_zone_alloc(xfs_buf_zone, xb_to_km(flags)) | |
91 | #define xfs_buf_deallocate(bp) \ | |
92 | kmem_zone_free(xfs_buf_zone, (bp)); | |
1da177e4 LT |
93 | |
94 | /* | |
ce8e922c | 95 | * Page Region interfaces. |
1da177e4 | 96 | * |
ce8e922c NS |
97 | * For pages in filesystems where the blocksize is smaller than the |
98 | * pagesize, we use the page->private field (long) to hold a bitmap | |
99 | * of uptodate regions within the page. | |
1da177e4 | 100 | * |
ce8e922c | 101 | * Each such region is "bytes per page / bits per long" bytes long. |
1da177e4 | 102 | * |
ce8e922c NS |
103 | * NBPPR == number-of-bytes-per-page-region |
104 | * BTOPR == bytes-to-page-region (rounded up) | |
105 | * BTOPRT == bytes-to-page-region-truncated (rounded down) | |
1da177e4 LT |
106 | */ |
107 | #if (BITS_PER_LONG == 32) | |
108 | #define PRSHIFT (PAGE_CACHE_SHIFT - 5) /* (32 == 1<<5) */ | |
109 | #elif (BITS_PER_LONG == 64) | |
110 | #define PRSHIFT (PAGE_CACHE_SHIFT - 6) /* (64 == 1<<6) */ | |
111 | #else | |
112 | #error BITS_PER_LONG must be 32 or 64 | |
113 | #endif | |
114 | #define NBPPR (PAGE_CACHE_SIZE/BITS_PER_LONG) | |
115 | #define BTOPR(b) (((unsigned int)(b) + (NBPPR - 1)) >> PRSHIFT) | |
116 | #define BTOPRT(b) (((unsigned int)(b) >> PRSHIFT)) | |
117 | ||
118 | STATIC unsigned long | |
119 | page_region_mask( | |
120 | size_t offset, | |
121 | size_t length) | |
122 | { | |
123 | unsigned long mask; | |
124 | int first, final; | |
125 | ||
126 | first = BTOPR(offset); | |
127 | final = BTOPRT(offset + length - 1); | |
128 | first = min(first, final); | |
129 | ||
130 | mask = ~0UL; | |
131 | mask <<= BITS_PER_LONG - (final - first); | |
132 | mask >>= BITS_PER_LONG - (final); | |
133 | ||
134 | ASSERT(offset + length <= PAGE_CACHE_SIZE); | |
135 | ASSERT((final - first) < BITS_PER_LONG && (final - first) >= 0); | |
136 | ||
137 | return mask; | |
138 | } | |
139 | ||
140 | STATIC inline void | |
141 | set_page_region( | |
142 | struct page *page, | |
143 | size_t offset, | |
144 | size_t length) | |
145 | { | |
4c21e2f2 HD |
146 | set_page_private(page, |
147 | page_private(page) | page_region_mask(offset, length)); | |
148 | if (page_private(page) == ~0UL) | |
1da177e4 LT |
149 | SetPageUptodate(page); |
150 | } | |
151 | ||
152 | STATIC inline int | |
153 | test_page_region( | |
154 | struct page *page, | |
155 | size_t offset, | |
156 | size_t length) | |
157 | { | |
158 | unsigned long mask = page_region_mask(offset, length); | |
159 | ||
4c21e2f2 | 160 | return (mask && (page_private(page) & mask) == mask); |
1da177e4 LT |
161 | } |
162 | ||
163 | /* | |
ce8e922c | 164 | * Mapping of multi-page buffers into contiguous virtual space |
1da177e4 LT |
165 | */ |
166 | ||
167 | typedef struct a_list { | |
168 | void *vm_addr; | |
169 | struct a_list *next; | |
170 | } a_list_t; | |
171 | ||
172 | STATIC a_list_t *as_free_head; | |
173 | STATIC int as_list_len; | |
174 | STATIC DEFINE_SPINLOCK(as_lock); | |
175 | ||
176 | /* | |
ce8e922c | 177 | * Try to batch vunmaps because they are costly. |
1da177e4 LT |
178 | */ |
179 | STATIC void | |
180 | free_address( | |
181 | void *addr) | |
182 | { | |
183 | a_list_t *aentry; | |
184 | ||
7b04d717 | 185 | aentry = kmalloc(sizeof(a_list_t), GFP_NOWAIT); |
1da177e4 LT |
186 | if (likely(aentry)) { |
187 | spin_lock(&as_lock); | |
188 | aentry->next = as_free_head; | |
189 | aentry->vm_addr = addr; | |
190 | as_free_head = aentry; | |
191 | as_list_len++; | |
192 | spin_unlock(&as_lock); | |
193 | } else { | |
194 | vunmap(addr); | |
195 | } | |
196 | } | |
197 | ||
198 | STATIC void | |
199 | purge_addresses(void) | |
200 | { | |
201 | a_list_t *aentry, *old; | |
202 | ||
203 | if (as_free_head == NULL) | |
204 | return; | |
205 | ||
206 | spin_lock(&as_lock); | |
207 | aentry = as_free_head; | |
208 | as_free_head = NULL; | |
209 | as_list_len = 0; | |
210 | spin_unlock(&as_lock); | |
211 | ||
212 | while ((old = aentry) != NULL) { | |
213 | vunmap(aentry->vm_addr); | |
214 | aentry = aentry->next; | |
215 | kfree(old); | |
216 | } | |
217 | } | |
218 | ||
219 | /* | |
ce8e922c | 220 | * Internal xfs_buf_t object manipulation |
1da177e4 LT |
221 | */ |
222 | ||
223 | STATIC void | |
ce8e922c NS |
224 | _xfs_buf_initialize( |
225 | xfs_buf_t *bp, | |
1da177e4 | 226 | xfs_buftarg_t *target, |
204ab25f | 227 | xfs_off_t range_base, |
1da177e4 | 228 | size_t range_length, |
ce8e922c | 229 | xfs_buf_flags_t flags) |
1da177e4 LT |
230 | { |
231 | /* | |
ce8e922c | 232 | * We don't want certain flags to appear in b_flags. |
1da177e4 | 233 | */ |
ce8e922c NS |
234 | flags &= ~(XBF_LOCK|XBF_MAPPED|XBF_DONT_BLOCK|XBF_READ_AHEAD); |
235 | ||
236 | memset(bp, 0, sizeof(xfs_buf_t)); | |
237 | atomic_set(&bp->b_hold, 1); | |
238 | init_MUTEX_LOCKED(&bp->b_iodonesema); | |
239 | INIT_LIST_HEAD(&bp->b_list); | |
240 | INIT_LIST_HEAD(&bp->b_hash_list); | |
241 | init_MUTEX_LOCKED(&bp->b_sema); /* held, no waiters */ | |
242 | XB_SET_OWNER(bp); | |
243 | bp->b_target = target; | |
244 | bp->b_file_offset = range_base; | |
1da177e4 LT |
245 | /* |
246 | * Set buffer_length and count_desired to the same value initially. | |
247 | * I/O routines should use count_desired, which will be the same in | |
248 | * most cases but may be reset (e.g. XFS recovery). | |
249 | */ | |
ce8e922c NS |
250 | bp->b_buffer_length = bp->b_count_desired = range_length; |
251 | bp->b_flags = flags; | |
252 | bp->b_bn = XFS_BUF_DADDR_NULL; | |
253 | atomic_set(&bp->b_pin_count, 0); | |
254 | init_waitqueue_head(&bp->b_waiters); | |
255 | ||
256 | XFS_STATS_INC(xb_create); | |
257 | XB_TRACE(bp, "initialize", target); | |
1da177e4 LT |
258 | } |
259 | ||
260 | /* | |
ce8e922c NS |
261 | * Allocate a page array capable of holding a specified number |
262 | * of pages, and point the page buf at it. | |
1da177e4 LT |
263 | */ |
264 | STATIC int | |
ce8e922c NS |
265 | _xfs_buf_get_pages( |
266 | xfs_buf_t *bp, | |
1da177e4 | 267 | int page_count, |
ce8e922c | 268 | xfs_buf_flags_t flags) |
1da177e4 LT |
269 | { |
270 | /* Make sure that we have a page list */ | |
ce8e922c NS |
271 | if (bp->b_pages == NULL) { |
272 | bp->b_offset = xfs_buf_poff(bp->b_file_offset); | |
273 | bp->b_page_count = page_count; | |
274 | if (page_count <= XB_PAGES) { | |
275 | bp->b_pages = bp->b_page_array; | |
1da177e4 | 276 | } else { |
ce8e922c NS |
277 | bp->b_pages = kmem_alloc(sizeof(struct page *) * |
278 | page_count, xb_to_km(flags)); | |
279 | if (bp->b_pages == NULL) | |
1da177e4 LT |
280 | return -ENOMEM; |
281 | } | |
ce8e922c | 282 | memset(bp->b_pages, 0, sizeof(struct page *) * page_count); |
1da177e4 LT |
283 | } |
284 | return 0; | |
285 | } | |
286 | ||
287 | /* | |
ce8e922c | 288 | * Frees b_pages if it was allocated. |
1da177e4 LT |
289 | */ |
290 | STATIC void | |
ce8e922c | 291 | _xfs_buf_free_pages( |
1da177e4 LT |
292 | xfs_buf_t *bp) |
293 | { | |
ce8e922c NS |
294 | if (bp->b_pages != bp->b_page_array) { |
295 | kmem_free(bp->b_pages, | |
296 | bp->b_page_count * sizeof(struct page *)); | |
1da177e4 LT |
297 | } |
298 | } | |
299 | ||
300 | /* | |
301 | * Releases the specified buffer. | |
302 | * | |
303 | * The modification state of any associated pages is left unchanged. | |
ce8e922c | 304 | * The buffer most not be on any hash - use xfs_buf_rele instead for |
1da177e4 LT |
305 | * hashed and refcounted buffers |
306 | */ | |
307 | void | |
ce8e922c | 308 | xfs_buf_free( |
1da177e4 LT |
309 | xfs_buf_t *bp) |
310 | { | |
ce8e922c | 311 | XB_TRACE(bp, "free", 0); |
1da177e4 | 312 | |
ce8e922c | 313 | ASSERT(list_empty(&bp->b_hash_list)); |
1da177e4 | 314 | |
ce8e922c | 315 | if (bp->b_flags & _XBF_PAGE_CACHE) { |
1da177e4 LT |
316 | uint i; |
317 | ||
ce8e922c NS |
318 | if ((bp->b_flags & XBF_MAPPED) && (bp->b_page_count > 1)) |
319 | free_address(bp->b_addr - bp->b_offset); | |
1da177e4 | 320 | |
ce8e922c NS |
321 | for (i = 0; i < bp->b_page_count; i++) |
322 | page_cache_release(bp->b_pages[i]); | |
323 | _xfs_buf_free_pages(bp); | |
324 | } else if (bp->b_flags & _XBF_KMEM_ALLOC) { | |
1da177e4 | 325 | /* |
ce8e922c NS |
326 | * XXX(hch): bp->b_count_desired might be incorrect (see |
327 | * xfs_buf_associate_memory for details), but fortunately | |
1da177e4 LT |
328 | * the Linux version of kmem_free ignores the len argument.. |
329 | */ | |
ce8e922c NS |
330 | kmem_free(bp->b_addr, bp->b_count_desired); |
331 | _xfs_buf_free_pages(bp); | |
1da177e4 LT |
332 | } |
333 | ||
ce8e922c | 334 | xfs_buf_deallocate(bp); |
1da177e4 LT |
335 | } |
336 | ||
337 | /* | |
338 | * Finds all pages for buffer in question and builds it's page list. | |
339 | */ | |
340 | STATIC int | |
ce8e922c | 341 | _xfs_buf_lookup_pages( |
1da177e4 LT |
342 | xfs_buf_t *bp, |
343 | uint flags) | |
344 | { | |
ce8e922c NS |
345 | struct address_space *mapping = bp->b_target->bt_mapping; |
346 | size_t blocksize = bp->b_target->bt_bsize; | |
347 | size_t size = bp->b_count_desired; | |
1da177e4 | 348 | size_t nbytes, offset; |
ce8e922c | 349 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 LT |
350 | unsigned short page_count, i; |
351 | pgoff_t first; | |
204ab25f | 352 | xfs_off_t end; |
1da177e4 LT |
353 | int error; |
354 | ||
ce8e922c NS |
355 | end = bp->b_file_offset + bp->b_buffer_length; |
356 | page_count = xfs_buf_btoc(end) - xfs_buf_btoct(bp->b_file_offset); | |
1da177e4 | 357 | |
ce8e922c | 358 | error = _xfs_buf_get_pages(bp, page_count, flags); |
1da177e4 LT |
359 | if (unlikely(error)) |
360 | return error; | |
ce8e922c | 361 | bp->b_flags |= _XBF_PAGE_CACHE; |
1da177e4 | 362 | |
ce8e922c NS |
363 | offset = bp->b_offset; |
364 | first = bp->b_file_offset >> PAGE_CACHE_SHIFT; | |
1da177e4 | 365 | |
ce8e922c | 366 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
367 | struct page *page; |
368 | uint retries = 0; | |
369 | ||
370 | retry: | |
371 | page = find_or_create_page(mapping, first + i, gfp_mask); | |
372 | if (unlikely(page == NULL)) { | |
ce8e922c NS |
373 | if (flags & XBF_READ_AHEAD) { |
374 | bp->b_page_count = i; | |
375 | for (i = 0; i < bp->b_page_count; i++) | |
376 | unlock_page(bp->b_pages[i]); | |
1da177e4 LT |
377 | return -ENOMEM; |
378 | } | |
379 | ||
380 | /* | |
381 | * This could deadlock. | |
382 | * | |
383 | * But until all the XFS lowlevel code is revamped to | |
384 | * handle buffer allocation failures we can't do much. | |
385 | */ | |
386 | if (!(++retries % 100)) | |
387 | printk(KERN_ERR | |
388 | "XFS: possible memory allocation " | |
389 | "deadlock in %s (mode:0x%x)\n", | |
390 | __FUNCTION__, gfp_mask); | |
391 | ||
ce8e922c | 392 | XFS_STATS_INC(xb_page_retries); |
23ea4032 | 393 | xfsbufd_wakeup(0, gfp_mask); |
1da177e4 LT |
394 | blk_congestion_wait(WRITE, HZ/50); |
395 | goto retry; | |
396 | } | |
397 | ||
ce8e922c | 398 | XFS_STATS_INC(xb_page_found); |
1da177e4 LT |
399 | |
400 | nbytes = min_t(size_t, size, PAGE_CACHE_SIZE - offset); | |
401 | size -= nbytes; | |
402 | ||
403 | if (!PageUptodate(page)) { | |
404 | page_count--; | |
405 | if (blocksize >= PAGE_CACHE_SIZE) { | |
ce8e922c NS |
406 | if (flags & XBF_READ) |
407 | bp->b_locked = 1; | |
1da177e4 LT |
408 | } else if (!PagePrivate(page)) { |
409 | if (test_page_region(page, offset, nbytes)) | |
410 | page_count++; | |
411 | } | |
412 | } | |
413 | ||
ce8e922c | 414 | bp->b_pages[i] = page; |
1da177e4 LT |
415 | offset = 0; |
416 | } | |
417 | ||
ce8e922c NS |
418 | if (!bp->b_locked) { |
419 | for (i = 0; i < bp->b_page_count; i++) | |
420 | unlock_page(bp->b_pages[i]); | |
1da177e4 LT |
421 | } |
422 | ||
ce8e922c NS |
423 | if (page_count == bp->b_page_count) |
424 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 425 | |
ce8e922c | 426 | XB_TRACE(bp, "lookup_pages", (long)page_count); |
1da177e4 LT |
427 | return error; |
428 | } | |
429 | ||
430 | /* | |
431 | * Map buffer into kernel address-space if nessecary. | |
432 | */ | |
433 | STATIC int | |
ce8e922c | 434 | _xfs_buf_map_pages( |
1da177e4 LT |
435 | xfs_buf_t *bp, |
436 | uint flags) | |
437 | { | |
438 | /* A single page buffer is always mappable */ | |
ce8e922c NS |
439 | if (bp->b_page_count == 1) { |
440 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; | |
441 | bp->b_flags |= XBF_MAPPED; | |
442 | } else if (flags & XBF_MAPPED) { | |
1da177e4 LT |
443 | if (as_list_len > 64) |
444 | purge_addresses(); | |
ce8e922c NS |
445 | bp->b_addr = vmap(bp->b_pages, bp->b_page_count, |
446 | VM_MAP, PAGE_KERNEL); | |
447 | if (unlikely(bp->b_addr == NULL)) | |
1da177e4 | 448 | return -ENOMEM; |
ce8e922c NS |
449 | bp->b_addr += bp->b_offset; |
450 | bp->b_flags |= XBF_MAPPED; | |
1da177e4 LT |
451 | } |
452 | ||
453 | return 0; | |
454 | } | |
455 | ||
456 | /* | |
457 | * Finding and Reading Buffers | |
458 | */ | |
459 | ||
460 | /* | |
ce8e922c | 461 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 LT |
462 | * a given range of an inode. The buffer is returned |
463 | * locked. If other overlapping buffers exist, they are | |
464 | * released before the new buffer is created and locked, | |
465 | * which may imply that this call will block until those buffers | |
466 | * are unlocked. No I/O is implied by this call. | |
467 | */ | |
468 | xfs_buf_t * | |
ce8e922c | 469 | _xfs_buf_find( |
1da177e4 | 470 | xfs_buftarg_t *btp, /* block device target */ |
204ab25f | 471 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 472 | size_t isize, /* length of range */ |
ce8e922c NS |
473 | xfs_buf_flags_t flags, |
474 | xfs_buf_t *new_bp) | |
1da177e4 | 475 | { |
204ab25f | 476 | xfs_off_t range_base; |
1da177e4 LT |
477 | size_t range_length; |
478 | xfs_bufhash_t *hash; | |
ce8e922c | 479 | xfs_buf_t *bp, *n; |
1da177e4 LT |
480 | |
481 | range_base = (ioff << BBSHIFT); | |
482 | range_length = (isize << BBSHIFT); | |
483 | ||
484 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
ce8e922c | 485 | ASSERT(!(range_length < (1 << btp->bt_sshift))); |
204ab25f | 486 | ASSERT(!(range_base & (xfs_off_t)btp->bt_smask)); |
1da177e4 LT |
487 | |
488 | hash = &btp->bt_hash[hash_long((unsigned long)ioff, btp->bt_hashshift)]; | |
489 | ||
490 | spin_lock(&hash->bh_lock); | |
491 | ||
ce8e922c NS |
492 | list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) { |
493 | ASSERT(btp == bp->b_target); | |
494 | if (bp->b_file_offset == range_base && | |
495 | bp->b_buffer_length == range_length) { | |
1da177e4 | 496 | /* |
ce8e922c | 497 | * If we look at something, bring it to the |
1da177e4 LT |
498 | * front of the list for next time. |
499 | */ | |
ce8e922c NS |
500 | atomic_inc(&bp->b_hold); |
501 | list_move(&bp->b_hash_list, &hash->bh_list); | |
1da177e4 LT |
502 | goto found; |
503 | } | |
504 | } | |
505 | ||
506 | /* No match found */ | |
ce8e922c NS |
507 | if (new_bp) { |
508 | _xfs_buf_initialize(new_bp, btp, range_base, | |
1da177e4 | 509 | range_length, flags); |
ce8e922c NS |
510 | new_bp->b_hash = hash; |
511 | list_add(&new_bp->b_hash_list, &hash->bh_list); | |
1da177e4 | 512 | } else { |
ce8e922c | 513 | XFS_STATS_INC(xb_miss_locked); |
1da177e4 LT |
514 | } |
515 | ||
516 | spin_unlock(&hash->bh_lock); | |
ce8e922c | 517 | return new_bp; |
1da177e4 LT |
518 | |
519 | found: | |
520 | spin_unlock(&hash->bh_lock); | |
521 | ||
522 | /* Attempt to get the semaphore without sleeping, | |
523 | * if this does not work then we need to drop the | |
524 | * spinlock and do a hard attempt on the semaphore. | |
525 | */ | |
ce8e922c NS |
526 | if (down_trylock(&bp->b_sema)) { |
527 | if (!(flags & XBF_TRYLOCK)) { | |
1da177e4 | 528 | /* wait for buffer ownership */ |
ce8e922c NS |
529 | XB_TRACE(bp, "get_lock", 0); |
530 | xfs_buf_lock(bp); | |
531 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 LT |
532 | } else { |
533 | /* We asked for a trylock and failed, no need | |
534 | * to look at file offset and length here, we | |
ce8e922c NS |
535 | * know that this buffer at least overlaps our |
536 | * buffer and is locked, therefore our buffer | |
537 | * either does not exist, or is this buffer. | |
1da177e4 | 538 | */ |
ce8e922c NS |
539 | xfs_buf_rele(bp); |
540 | XFS_STATS_INC(xb_busy_locked); | |
541 | return NULL; | |
1da177e4 LT |
542 | } |
543 | } else { | |
544 | /* trylock worked */ | |
ce8e922c | 545 | XB_SET_OWNER(bp); |
1da177e4 LT |
546 | } |
547 | ||
ce8e922c NS |
548 | if (bp->b_flags & XBF_STALE) { |
549 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
550 | bp->b_flags &= XBF_MAPPED; | |
2f926587 | 551 | } |
ce8e922c NS |
552 | XB_TRACE(bp, "got_lock", 0); |
553 | XFS_STATS_INC(xb_get_locked); | |
554 | return bp; | |
1da177e4 LT |
555 | } |
556 | ||
557 | /* | |
ce8e922c | 558 | * Assembles a buffer covering the specified range. |
1da177e4 LT |
559 | * Storage in memory for all portions of the buffer will be allocated, |
560 | * although backing storage may not be. | |
561 | */ | |
562 | xfs_buf_t * | |
ce8e922c | 563 | xfs_buf_get_flags( |
1da177e4 | 564 | xfs_buftarg_t *target,/* target for buffer */ |
204ab25f | 565 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 566 | size_t isize, /* length of range */ |
ce8e922c | 567 | xfs_buf_flags_t flags) |
1da177e4 | 568 | { |
ce8e922c | 569 | xfs_buf_t *bp, *new_bp; |
1da177e4 LT |
570 | int error = 0, i; |
571 | ||
ce8e922c NS |
572 | new_bp = xfs_buf_allocate(flags); |
573 | if (unlikely(!new_bp)) | |
1da177e4 LT |
574 | return NULL; |
575 | ||
ce8e922c NS |
576 | bp = _xfs_buf_find(target, ioff, isize, flags, new_bp); |
577 | if (bp == new_bp) { | |
578 | error = _xfs_buf_lookup_pages(bp, flags); | |
1da177e4 LT |
579 | if (error) |
580 | goto no_buffer; | |
581 | } else { | |
ce8e922c NS |
582 | xfs_buf_deallocate(new_bp); |
583 | if (unlikely(bp == NULL)) | |
1da177e4 LT |
584 | return NULL; |
585 | } | |
586 | ||
ce8e922c NS |
587 | for (i = 0; i < bp->b_page_count; i++) |
588 | mark_page_accessed(bp->b_pages[i]); | |
1da177e4 | 589 | |
ce8e922c NS |
590 | if (!(bp->b_flags & XBF_MAPPED)) { |
591 | error = _xfs_buf_map_pages(bp, flags); | |
1da177e4 LT |
592 | if (unlikely(error)) { |
593 | printk(KERN_WARNING "%s: failed to map pages\n", | |
594 | __FUNCTION__); | |
595 | goto no_buffer; | |
596 | } | |
597 | } | |
598 | ||
ce8e922c | 599 | XFS_STATS_INC(xb_get); |
1da177e4 LT |
600 | |
601 | /* | |
602 | * Always fill in the block number now, the mapped cases can do | |
603 | * their own overlay of this later. | |
604 | */ | |
ce8e922c NS |
605 | bp->b_bn = ioff; |
606 | bp->b_count_desired = bp->b_buffer_length; | |
1da177e4 | 607 | |
ce8e922c NS |
608 | XB_TRACE(bp, "get", (unsigned long)flags); |
609 | return bp; | |
1da177e4 LT |
610 | |
611 | no_buffer: | |
ce8e922c NS |
612 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
613 | xfs_buf_unlock(bp); | |
614 | xfs_buf_rele(bp); | |
1da177e4 LT |
615 | return NULL; |
616 | } | |
617 | ||
618 | xfs_buf_t * | |
619 | xfs_buf_read_flags( | |
620 | xfs_buftarg_t *target, | |
204ab25f | 621 | xfs_off_t ioff, |
1da177e4 | 622 | size_t isize, |
ce8e922c | 623 | xfs_buf_flags_t flags) |
1da177e4 | 624 | { |
ce8e922c NS |
625 | xfs_buf_t *bp; |
626 | ||
627 | flags |= XBF_READ; | |
628 | ||
629 | bp = xfs_buf_get_flags(target, ioff, isize, flags); | |
630 | if (bp) { | |
631 | if (!XFS_BUF_ISDONE(bp)) { | |
632 | XB_TRACE(bp, "read", (unsigned long)flags); | |
633 | XFS_STATS_INC(xb_get_read); | |
634 | xfs_buf_iostart(bp, flags); | |
635 | } else if (flags & XBF_ASYNC) { | |
636 | XB_TRACE(bp, "read_async", (unsigned long)flags); | |
1da177e4 LT |
637 | /* |
638 | * Read ahead call which is already satisfied, | |
639 | * drop the buffer | |
640 | */ | |
641 | goto no_buffer; | |
642 | } else { | |
ce8e922c | 643 | XB_TRACE(bp, "read_done", (unsigned long)flags); |
1da177e4 | 644 | /* We do not want read in the flags */ |
ce8e922c | 645 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
646 | } |
647 | } | |
648 | ||
ce8e922c | 649 | return bp; |
1da177e4 LT |
650 | |
651 | no_buffer: | |
ce8e922c NS |
652 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
653 | xfs_buf_unlock(bp); | |
654 | xfs_buf_rele(bp); | |
1da177e4 LT |
655 | return NULL; |
656 | } | |
657 | ||
1da177e4 | 658 | /* |
ce8e922c NS |
659 | * If we are not low on memory then do the readahead in a deadlock |
660 | * safe manner. | |
1da177e4 LT |
661 | */ |
662 | void | |
ce8e922c | 663 | xfs_buf_readahead( |
1da177e4 | 664 | xfs_buftarg_t *target, |
204ab25f | 665 | xfs_off_t ioff, |
1da177e4 | 666 | size_t isize, |
ce8e922c | 667 | xfs_buf_flags_t flags) |
1da177e4 LT |
668 | { |
669 | struct backing_dev_info *bdi; | |
670 | ||
ce8e922c | 671 | bdi = target->bt_mapping->backing_dev_info; |
1da177e4 LT |
672 | if (bdi_read_congested(bdi)) |
673 | return; | |
674 | ||
ce8e922c | 675 | flags |= (XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD); |
1da177e4 LT |
676 | xfs_buf_read_flags(target, ioff, isize, flags); |
677 | } | |
678 | ||
679 | xfs_buf_t * | |
ce8e922c | 680 | xfs_buf_get_empty( |
1da177e4 LT |
681 | size_t len, |
682 | xfs_buftarg_t *target) | |
683 | { | |
ce8e922c | 684 | xfs_buf_t *bp; |
1da177e4 | 685 | |
ce8e922c NS |
686 | bp = xfs_buf_allocate(0); |
687 | if (bp) | |
688 | _xfs_buf_initialize(bp, target, 0, len, 0); | |
689 | return bp; | |
1da177e4 LT |
690 | } |
691 | ||
692 | static inline struct page * | |
693 | mem_to_page( | |
694 | void *addr) | |
695 | { | |
696 | if (((unsigned long)addr < VMALLOC_START) || | |
697 | ((unsigned long)addr >= VMALLOC_END)) { | |
698 | return virt_to_page(addr); | |
699 | } else { | |
700 | return vmalloc_to_page(addr); | |
701 | } | |
702 | } | |
703 | ||
704 | int | |
ce8e922c NS |
705 | xfs_buf_associate_memory( |
706 | xfs_buf_t *bp, | |
1da177e4 LT |
707 | void *mem, |
708 | size_t len) | |
709 | { | |
710 | int rval; | |
711 | int i = 0; | |
712 | size_t ptr; | |
713 | size_t end, end_cur; | |
714 | off_t offset; | |
715 | int page_count; | |
716 | ||
717 | page_count = PAGE_CACHE_ALIGN(len) >> PAGE_CACHE_SHIFT; | |
718 | offset = (off_t) mem - ((off_t)mem & PAGE_CACHE_MASK); | |
719 | if (offset && (len > PAGE_CACHE_SIZE)) | |
720 | page_count++; | |
721 | ||
722 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
723 | if (bp->b_pages) |
724 | _xfs_buf_free_pages(bp); | |
1da177e4 | 725 | |
ce8e922c NS |
726 | bp->b_pages = NULL; |
727 | bp->b_addr = mem; | |
1da177e4 | 728 | |
ce8e922c | 729 | rval = _xfs_buf_get_pages(bp, page_count, 0); |
1da177e4 LT |
730 | if (rval) |
731 | return rval; | |
732 | ||
ce8e922c | 733 | bp->b_offset = offset; |
1da177e4 LT |
734 | ptr = (size_t) mem & PAGE_CACHE_MASK; |
735 | end = PAGE_CACHE_ALIGN((size_t) mem + len); | |
736 | end_cur = end; | |
737 | /* set up first page */ | |
ce8e922c | 738 | bp->b_pages[0] = mem_to_page(mem); |
1da177e4 LT |
739 | |
740 | ptr += PAGE_CACHE_SIZE; | |
ce8e922c | 741 | bp->b_page_count = ++i; |
1da177e4 | 742 | while (ptr < end) { |
ce8e922c NS |
743 | bp->b_pages[i] = mem_to_page((void *)ptr); |
744 | bp->b_page_count = ++i; | |
1da177e4 LT |
745 | ptr += PAGE_CACHE_SIZE; |
746 | } | |
ce8e922c | 747 | bp->b_locked = 0; |
1da177e4 | 748 | |
ce8e922c NS |
749 | bp->b_count_desired = bp->b_buffer_length = len; |
750 | bp->b_flags |= XBF_MAPPED; | |
1da177e4 LT |
751 | |
752 | return 0; | |
753 | } | |
754 | ||
755 | xfs_buf_t * | |
ce8e922c | 756 | xfs_buf_get_noaddr( |
1da177e4 LT |
757 | size_t len, |
758 | xfs_buftarg_t *target) | |
759 | { | |
760 | size_t malloc_len = len; | |
761 | xfs_buf_t *bp; | |
762 | void *data; | |
763 | int error; | |
764 | ||
ce8e922c | 765 | bp = xfs_buf_allocate(0); |
1da177e4 LT |
766 | if (unlikely(bp == NULL)) |
767 | goto fail; | |
ce8e922c | 768 | _xfs_buf_initialize(bp, target, 0, len, 0); |
1da177e4 LT |
769 | |
770 | try_again: | |
771 | data = kmem_alloc(malloc_len, KM_SLEEP | KM_MAYFAIL); | |
772 | if (unlikely(data == NULL)) | |
773 | goto fail_free_buf; | |
774 | ||
775 | /* check whether alignment matches.. */ | |
776 | if ((__psunsigned_t)data != | |
ce8e922c | 777 | ((__psunsigned_t)data & ~target->bt_smask)) { |
1da177e4 LT |
778 | /* .. else double the size and try again */ |
779 | kmem_free(data, malloc_len); | |
780 | malloc_len <<= 1; | |
781 | goto try_again; | |
782 | } | |
783 | ||
ce8e922c | 784 | error = xfs_buf_associate_memory(bp, data, len); |
1da177e4 LT |
785 | if (error) |
786 | goto fail_free_mem; | |
ce8e922c | 787 | bp->b_flags |= _XBF_KMEM_ALLOC; |
1da177e4 | 788 | |
ce8e922c | 789 | xfs_buf_unlock(bp); |
1da177e4 | 790 | |
ce8e922c | 791 | XB_TRACE(bp, "no_daddr", data); |
1da177e4 LT |
792 | return bp; |
793 | fail_free_mem: | |
794 | kmem_free(data, malloc_len); | |
795 | fail_free_buf: | |
ce8e922c | 796 | xfs_buf_free(bp); |
1da177e4 LT |
797 | fail: |
798 | return NULL; | |
799 | } | |
800 | ||
801 | /* | |
1da177e4 LT |
802 | * Increment reference count on buffer, to hold the buffer concurrently |
803 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
804 | * Must hold the buffer already to call this function. |
805 | */ | |
806 | void | |
ce8e922c NS |
807 | xfs_buf_hold( |
808 | xfs_buf_t *bp) | |
1da177e4 | 809 | { |
ce8e922c NS |
810 | atomic_inc(&bp->b_hold); |
811 | XB_TRACE(bp, "hold", 0); | |
1da177e4 LT |
812 | } |
813 | ||
814 | /* | |
ce8e922c NS |
815 | * Releases a hold on the specified buffer. If the |
816 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
817 | */ |
818 | void | |
ce8e922c NS |
819 | xfs_buf_rele( |
820 | xfs_buf_t *bp) | |
1da177e4 | 821 | { |
ce8e922c | 822 | xfs_bufhash_t *hash = bp->b_hash; |
1da177e4 | 823 | |
ce8e922c | 824 | XB_TRACE(bp, "rele", bp->b_relse); |
1da177e4 | 825 | |
fad3aa1e NS |
826 | if (unlikely(!hash)) { |
827 | ASSERT(!bp->b_relse); | |
828 | if (atomic_dec_and_test(&bp->b_hold)) | |
829 | xfs_buf_free(bp); | |
830 | return; | |
831 | } | |
832 | ||
ce8e922c NS |
833 | if (atomic_dec_and_lock(&bp->b_hold, &hash->bh_lock)) { |
834 | if (bp->b_relse) { | |
835 | atomic_inc(&bp->b_hold); | |
1da177e4 | 836 | spin_unlock(&hash->bh_lock); |
ce8e922c NS |
837 | (*(bp->b_relse)) (bp); |
838 | } else if (bp->b_flags & XBF_FS_MANAGED) { | |
1da177e4 | 839 | spin_unlock(&hash->bh_lock); |
1da177e4 | 840 | } else { |
ce8e922c NS |
841 | ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q))); |
842 | list_del_init(&bp->b_hash_list); | |
1da177e4 | 843 | spin_unlock(&hash->bh_lock); |
ce8e922c | 844 | xfs_buf_free(bp); |
1da177e4 | 845 | } |
2f926587 DC |
846 | } else { |
847 | /* | |
848 | * Catch reference count leaks | |
849 | */ | |
ce8e922c | 850 | ASSERT(atomic_read(&bp->b_hold) >= 0); |
1da177e4 LT |
851 | } |
852 | } | |
853 | ||
854 | ||
855 | /* | |
856 | * Mutual exclusion on buffers. Locking model: | |
857 | * | |
858 | * Buffers associated with inodes for which buffer locking | |
859 | * is not enabled are not protected by semaphores, and are | |
860 | * assumed to be exclusively owned by the caller. There is a | |
861 | * spinlock in the buffer, used by the caller when concurrent | |
862 | * access is possible. | |
863 | */ | |
864 | ||
865 | /* | |
ce8e922c NS |
866 | * Locks a buffer object, if it is not already locked. |
867 | * Note that this in no way locks the underlying pages, so it is only | |
868 | * useful for synchronizing concurrent use of buffer objects, not for | |
869 | * synchronizing independent access to the underlying pages. | |
1da177e4 LT |
870 | */ |
871 | int | |
ce8e922c NS |
872 | xfs_buf_cond_lock( |
873 | xfs_buf_t *bp) | |
1da177e4 LT |
874 | { |
875 | int locked; | |
876 | ||
ce8e922c | 877 | locked = down_trylock(&bp->b_sema) == 0; |
1da177e4 | 878 | if (locked) { |
ce8e922c | 879 | XB_SET_OWNER(bp); |
1da177e4 | 880 | } |
ce8e922c NS |
881 | XB_TRACE(bp, "cond_lock", (long)locked); |
882 | return locked ? 0 : -EBUSY; | |
1da177e4 LT |
883 | } |
884 | ||
885 | #if defined(DEBUG) || defined(XFS_BLI_TRACE) | |
1da177e4 | 886 | int |
ce8e922c NS |
887 | xfs_buf_lock_value( |
888 | xfs_buf_t *bp) | |
1da177e4 | 889 | { |
ce8e922c | 890 | return atomic_read(&bp->b_sema.count); |
1da177e4 LT |
891 | } |
892 | #endif | |
893 | ||
894 | /* | |
ce8e922c NS |
895 | * Locks a buffer object. |
896 | * Note that this in no way locks the underlying pages, so it is only | |
897 | * useful for synchronizing concurrent use of buffer objects, not for | |
898 | * synchronizing independent access to the underlying pages. | |
1da177e4 | 899 | */ |
ce8e922c NS |
900 | void |
901 | xfs_buf_lock( | |
902 | xfs_buf_t *bp) | |
1da177e4 | 903 | { |
ce8e922c NS |
904 | XB_TRACE(bp, "lock", 0); |
905 | if (atomic_read(&bp->b_io_remaining)) | |
906 | blk_run_address_space(bp->b_target->bt_mapping); | |
907 | down(&bp->b_sema); | |
908 | XB_SET_OWNER(bp); | |
909 | XB_TRACE(bp, "locked", 0); | |
1da177e4 LT |
910 | } |
911 | ||
912 | /* | |
ce8e922c | 913 | * Releases the lock on the buffer object. |
2f926587 | 914 | * If the buffer is marked delwri but is not queued, do so before we |
ce8e922c | 915 | * unlock the buffer as we need to set flags correctly. We also need to |
2f926587 DC |
916 | * take a reference for the delwri queue because the unlocker is going to |
917 | * drop their's and they don't know we just queued it. | |
1da177e4 LT |
918 | */ |
919 | void | |
ce8e922c NS |
920 | xfs_buf_unlock( |
921 | xfs_buf_t *bp) | |
1da177e4 | 922 | { |
ce8e922c NS |
923 | if ((bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)) == XBF_DELWRI) { |
924 | atomic_inc(&bp->b_hold); | |
925 | bp->b_flags |= XBF_ASYNC; | |
926 | xfs_buf_delwri_queue(bp, 0); | |
2f926587 DC |
927 | } |
928 | ||
ce8e922c NS |
929 | XB_CLEAR_OWNER(bp); |
930 | up(&bp->b_sema); | |
931 | XB_TRACE(bp, "unlock", 0); | |
1da177e4 LT |
932 | } |
933 | ||
934 | ||
935 | /* | |
936 | * Pinning Buffer Storage in Memory | |
ce8e922c | 937 | * Ensure that no attempt to force a buffer to disk will succeed. |
1da177e4 LT |
938 | */ |
939 | void | |
ce8e922c NS |
940 | xfs_buf_pin( |
941 | xfs_buf_t *bp) | |
1da177e4 | 942 | { |
ce8e922c NS |
943 | atomic_inc(&bp->b_pin_count); |
944 | XB_TRACE(bp, "pin", (long)bp->b_pin_count.counter); | |
1da177e4 LT |
945 | } |
946 | ||
1da177e4 | 947 | void |
ce8e922c NS |
948 | xfs_buf_unpin( |
949 | xfs_buf_t *bp) | |
1da177e4 | 950 | { |
ce8e922c NS |
951 | if (atomic_dec_and_test(&bp->b_pin_count)) |
952 | wake_up_all(&bp->b_waiters); | |
953 | XB_TRACE(bp, "unpin", (long)bp->b_pin_count.counter); | |
1da177e4 LT |
954 | } |
955 | ||
956 | int | |
ce8e922c NS |
957 | xfs_buf_ispin( |
958 | xfs_buf_t *bp) | |
1da177e4 | 959 | { |
ce8e922c | 960 | return atomic_read(&bp->b_pin_count); |
1da177e4 LT |
961 | } |
962 | ||
ce8e922c NS |
963 | STATIC void |
964 | xfs_buf_wait_unpin( | |
965 | xfs_buf_t *bp) | |
1da177e4 LT |
966 | { |
967 | DECLARE_WAITQUEUE (wait, current); | |
968 | ||
ce8e922c | 969 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
970 | return; |
971 | ||
ce8e922c | 972 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
973 | for (;;) { |
974 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 975 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 976 | break; |
ce8e922c NS |
977 | if (atomic_read(&bp->b_io_remaining)) |
978 | blk_run_address_space(bp->b_target->bt_mapping); | |
1da177e4 LT |
979 | schedule(); |
980 | } | |
ce8e922c | 981 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
982 | set_current_state(TASK_RUNNING); |
983 | } | |
984 | ||
985 | /* | |
986 | * Buffer Utility Routines | |
987 | */ | |
988 | ||
1da177e4 | 989 | STATIC void |
ce8e922c | 990 | xfs_buf_iodone_work( |
1da177e4 LT |
991 | void *v) |
992 | { | |
993 | xfs_buf_t *bp = (xfs_buf_t *)v; | |
994 | ||
ce8e922c NS |
995 | if (bp->b_iodone) |
996 | (*(bp->b_iodone))(bp); | |
997 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 LT |
998 | xfs_buf_relse(bp); |
999 | } | |
1000 | ||
1001 | void | |
ce8e922c NS |
1002 | xfs_buf_ioend( |
1003 | xfs_buf_t *bp, | |
1da177e4 LT |
1004 | int schedule) |
1005 | { | |
ce8e922c NS |
1006 | bp->b_flags &= ~(XBF_READ | XBF_WRITE); |
1007 | if (bp->b_error == 0) | |
1008 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1009 | |
ce8e922c | 1010 | XB_TRACE(bp, "iodone", bp->b_iodone); |
1da177e4 | 1011 | |
ce8e922c | 1012 | if ((bp->b_iodone) || (bp->b_flags & XBF_ASYNC)) { |
1da177e4 | 1013 | if (schedule) { |
ce8e922c NS |
1014 | INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work, bp); |
1015 | queue_work(xfslogd_workqueue, &bp->b_iodone_work); | |
1da177e4 | 1016 | } else { |
ce8e922c | 1017 | xfs_buf_iodone_work(bp); |
1da177e4 LT |
1018 | } |
1019 | } else { | |
ce8e922c | 1020 | up(&bp->b_iodonesema); |
1da177e4 LT |
1021 | } |
1022 | } | |
1023 | ||
1da177e4 | 1024 | void |
ce8e922c NS |
1025 | xfs_buf_ioerror( |
1026 | xfs_buf_t *bp, | |
1027 | int error) | |
1da177e4 LT |
1028 | { |
1029 | ASSERT(error >= 0 && error <= 0xffff); | |
ce8e922c NS |
1030 | bp->b_error = (unsigned short)error; |
1031 | XB_TRACE(bp, "ioerror", (unsigned long)error); | |
1da177e4 LT |
1032 | } |
1033 | ||
1034 | /* | |
ce8e922c NS |
1035 | * Initiate I/O on a buffer, based on the flags supplied. |
1036 | * The b_iodone routine in the buffer supplied will only be called | |
1da177e4 | 1037 | * when all of the subsidiary I/O requests, if any, have been completed. |
1da177e4 LT |
1038 | */ |
1039 | int | |
ce8e922c NS |
1040 | xfs_buf_iostart( |
1041 | xfs_buf_t *bp, | |
1042 | xfs_buf_flags_t flags) | |
1da177e4 LT |
1043 | { |
1044 | int status = 0; | |
1045 | ||
ce8e922c | 1046 | XB_TRACE(bp, "iostart", (unsigned long)flags); |
1da177e4 | 1047 | |
ce8e922c NS |
1048 | if (flags & XBF_DELWRI) { |
1049 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_ASYNC); | |
1050 | bp->b_flags |= flags & (XBF_DELWRI | XBF_ASYNC); | |
1051 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1052 | return status; |
1053 | } | |
1054 | ||
ce8e922c NS |
1055 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_ASYNC | XBF_DELWRI | \ |
1056 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
1057 | bp->b_flags |= flags & (XBF_READ | XBF_WRITE | XBF_ASYNC | \ | |
1058 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
1da177e4 | 1059 | |
ce8e922c | 1060 | BUG_ON(bp->b_bn == XFS_BUF_DADDR_NULL); |
1da177e4 LT |
1061 | |
1062 | /* For writes allow an alternate strategy routine to precede | |
1063 | * the actual I/O request (which may not be issued at all in | |
1064 | * a shutdown situation, for example). | |
1065 | */ | |
ce8e922c NS |
1066 | status = (flags & XBF_WRITE) ? |
1067 | xfs_buf_iostrategy(bp) : xfs_buf_iorequest(bp); | |
1da177e4 LT |
1068 | |
1069 | /* Wait for I/O if we are not an async request. | |
1070 | * Note: async I/O request completion will release the buffer, | |
1071 | * and that can already be done by this point. So using the | |
1072 | * buffer pointer from here on, after async I/O, is invalid. | |
1073 | */ | |
ce8e922c NS |
1074 | if (!status && !(flags & XBF_ASYNC)) |
1075 | status = xfs_buf_iowait(bp); | |
1da177e4 LT |
1076 | |
1077 | return status; | |
1078 | } | |
1079 | ||
1da177e4 | 1080 | STATIC __inline__ int |
ce8e922c NS |
1081 | _xfs_buf_iolocked( |
1082 | xfs_buf_t *bp) | |
1da177e4 | 1083 | { |
ce8e922c NS |
1084 | ASSERT(bp->b_flags & (XBF_READ | XBF_WRITE)); |
1085 | if (bp->b_flags & XBF_READ) | |
1086 | return bp->b_locked; | |
1da177e4 LT |
1087 | return 0; |
1088 | } | |
1089 | ||
1090 | STATIC __inline__ void | |
ce8e922c NS |
1091 | _xfs_buf_ioend( |
1092 | xfs_buf_t *bp, | |
1da177e4 LT |
1093 | int schedule) |
1094 | { | |
ce8e922c NS |
1095 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) { |
1096 | bp->b_locked = 0; | |
1097 | xfs_buf_ioend(bp, schedule); | |
1da177e4 LT |
1098 | } |
1099 | } | |
1100 | ||
1101 | STATIC int | |
ce8e922c | 1102 | xfs_buf_bio_end_io( |
1da177e4 LT |
1103 | struct bio *bio, |
1104 | unsigned int bytes_done, | |
1105 | int error) | |
1106 | { | |
ce8e922c NS |
1107 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1108 | unsigned int blocksize = bp->b_target->bt_bsize; | |
eedb5530 | 1109 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; |
1da177e4 LT |
1110 | |
1111 | if (bio->bi_size) | |
1112 | return 1; | |
1113 | ||
1114 | if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) | |
ce8e922c | 1115 | bp->b_error = EIO; |
1da177e4 | 1116 | |
eedb5530 | 1117 | do { |
1da177e4 LT |
1118 | struct page *page = bvec->bv_page; |
1119 | ||
ce8e922c NS |
1120 | if (unlikely(bp->b_error)) { |
1121 | if (bp->b_flags & XBF_READ) | |
eedb5530 | 1122 | ClearPageUptodate(page); |
1da177e4 | 1123 | SetPageError(page); |
ce8e922c | 1124 | } else if (blocksize >= PAGE_CACHE_SIZE) { |
1da177e4 LT |
1125 | SetPageUptodate(page); |
1126 | } else if (!PagePrivate(page) && | |
ce8e922c | 1127 | (bp->b_flags & _XBF_PAGE_CACHE)) { |
1da177e4 LT |
1128 | set_page_region(page, bvec->bv_offset, bvec->bv_len); |
1129 | } | |
1130 | ||
eedb5530 NS |
1131 | if (--bvec >= bio->bi_io_vec) |
1132 | prefetchw(&bvec->bv_page->flags); | |
1133 | ||
ce8e922c | 1134 | if (_xfs_buf_iolocked(bp)) { |
1da177e4 LT |
1135 | unlock_page(page); |
1136 | } | |
eedb5530 | 1137 | } while (bvec >= bio->bi_io_vec); |
1da177e4 | 1138 | |
ce8e922c | 1139 | _xfs_buf_ioend(bp, 1); |
1da177e4 LT |
1140 | bio_put(bio); |
1141 | return 0; | |
1142 | } | |
1143 | ||
1144 | STATIC void | |
ce8e922c NS |
1145 | _xfs_buf_ioapply( |
1146 | xfs_buf_t *bp) | |
1da177e4 LT |
1147 | { |
1148 | int i, rw, map_i, total_nr_pages, nr_pages; | |
1149 | struct bio *bio; | |
ce8e922c NS |
1150 | int offset = bp->b_offset; |
1151 | int size = bp->b_count_desired; | |
1152 | sector_t sector = bp->b_bn; | |
1153 | unsigned int blocksize = bp->b_target->bt_bsize; | |
1154 | int locking = _xfs_buf_iolocked(bp); | |
1da177e4 | 1155 | |
ce8e922c | 1156 | total_nr_pages = bp->b_page_count; |
1da177e4 LT |
1157 | map_i = 0; |
1158 | ||
ce8e922c NS |
1159 | if (bp->b_flags & _XBF_RUN_QUEUES) { |
1160 | bp->b_flags &= ~_XBF_RUN_QUEUES; | |
1161 | rw = (bp->b_flags & XBF_READ) ? READ_SYNC : WRITE_SYNC; | |
1da177e4 | 1162 | } else { |
ce8e922c | 1163 | rw = (bp->b_flags & XBF_READ) ? READ : WRITE; |
1da177e4 LT |
1164 | } |
1165 | ||
ce8e922c NS |
1166 | if (bp->b_flags & XBF_ORDERED) { |
1167 | ASSERT(!(bp->b_flags & XBF_READ)); | |
f538d4da CH |
1168 | rw = WRITE_BARRIER; |
1169 | } | |
1170 | ||
ce8e922c | 1171 | /* Special code path for reading a sub page size buffer in -- |
1da177e4 LT |
1172 | * we populate up the whole page, and hence the other metadata |
1173 | * in the same page. This optimization is only valid when the | |
ce8e922c | 1174 | * filesystem block size is not smaller than the page size. |
1da177e4 | 1175 | */ |
ce8e922c NS |
1176 | if ((bp->b_buffer_length < PAGE_CACHE_SIZE) && |
1177 | (bp->b_flags & XBF_READ) && locking && | |
1178 | (blocksize >= PAGE_CACHE_SIZE)) { | |
1da177e4 LT |
1179 | bio = bio_alloc(GFP_NOIO, 1); |
1180 | ||
ce8e922c | 1181 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1182 | bio->bi_sector = sector - (offset >> BBSHIFT); |
ce8e922c NS |
1183 | bio->bi_end_io = xfs_buf_bio_end_io; |
1184 | bio->bi_private = bp; | |
1da177e4 | 1185 | |
ce8e922c | 1186 | bio_add_page(bio, bp->b_pages[0], PAGE_CACHE_SIZE, 0); |
1da177e4 LT |
1187 | size = 0; |
1188 | ||
ce8e922c | 1189 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1190 | |
1191 | goto submit_io; | |
1192 | } | |
1193 | ||
1194 | /* Lock down the pages which we need to for the request */ | |
ce8e922c | 1195 | if (locking && (bp->b_flags & XBF_WRITE) && (bp->b_locked == 0)) { |
1da177e4 LT |
1196 | for (i = 0; size; i++) { |
1197 | int nbytes = PAGE_CACHE_SIZE - offset; | |
ce8e922c | 1198 | struct page *page = bp->b_pages[i]; |
1da177e4 LT |
1199 | |
1200 | if (nbytes > size) | |
1201 | nbytes = size; | |
1202 | ||
1203 | lock_page(page); | |
1204 | ||
1205 | size -= nbytes; | |
1206 | offset = 0; | |
1207 | } | |
ce8e922c NS |
1208 | offset = bp->b_offset; |
1209 | size = bp->b_count_desired; | |
1da177e4 LT |
1210 | } |
1211 | ||
1212 | next_chunk: | |
ce8e922c | 1213 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1214 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1215 | if (nr_pages > total_nr_pages) | |
1216 | nr_pages = total_nr_pages; | |
1217 | ||
1218 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1219 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1220 | bio->bi_sector = sector; |
ce8e922c NS |
1221 | bio->bi_end_io = xfs_buf_bio_end_io; |
1222 | bio->bi_private = bp; | |
1da177e4 LT |
1223 | |
1224 | for (; size && nr_pages; nr_pages--, map_i++) { | |
ce8e922c | 1225 | int rbytes, nbytes = PAGE_CACHE_SIZE - offset; |
1da177e4 LT |
1226 | |
1227 | if (nbytes > size) | |
1228 | nbytes = size; | |
1229 | ||
ce8e922c NS |
1230 | rbytes = bio_add_page(bio, bp->b_pages[map_i], nbytes, offset); |
1231 | if (rbytes < nbytes) | |
1da177e4 LT |
1232 | break; |
1233 | ||
1234 | offset = 0; | |
1235 | sector += nbytes >> BBSHIFT; | |
1236 | size -= nbytes; | |
1237 | total_nr_pages--; | |
1238 | } | |
1239 | ||
1240 | submit_io: | |
1241 | if (likely(bio->bi_size)) { | |
1242 | submit_bio(rw, bio); | |
1243 | if (size) | |
1244 | goto next_chunk; | |
1245 | } else { | |
1246 | bio_put(bio); | |
ce8e922c | 1247 | xfs_buf_ioerror(bp, EIO); |
1da177e4 LT |
1248 | } |
1249 | } | |
1250 | ||
1da177e4 | 1251 | int |
ce8e922c NS |
1252 | xfs_buf_iorequest( |
1253 | xfs_buf_t *bp) | |
1da177e4 | 1254 | { |
ce8e922c | 1255 | XB_TRACE(bp, "iorequest", 0); |
1da177e4 | 1256 | |
ce8e922c NS |
1257 | if (bp->b_flags & XBF_DELWRI) { |
1258 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1259 | return 0; |
1260 | } | |
1261 | ||
ce8e922c NS |
1262 | if (bp->b_flags & XBF_WRITE) { |
1263 | xfs_buf_wait_unpin(bp); | |
1da177e4 LT |
1264 | } |
1265 | ||
ce8e922c | 1266 | xfs_buf_hold(bp); |
1da177e4 LT |
1267 | |
1268 | /* Set the count to 1 initially, this will stop an I/O | |
1269 | * completion callout which happens before we have started | |
ce8e922c | 1270 | * all the I/O from calling xfs_buf_ioend too early. |
1da177e4 | 1271 | */ |
ce8e922c NS |
1272 | atomic_set(&bp->b_io_remaining, 1); |
1273 | _xfs_buf_ioapply(bp); | |
1274 | _xfs_buf_ioend(bp, 0); | |
1da177e4 | 1275 | |
ce8e922c | 1276 | xfs_buf_rele(bp); |
1da177e4 LT |
1277 | return 0; |
1278 | } | |
1279 | ||
1280 | /* | |
ce8e922c NS |
1281 | * Waits for I/O to complete on the buffer supplied. |
1282 | * It returns immediately if no I/O is pending. | |
1283 | * It returns the I/O error code, if any, or 0 if there was no error. | |
1da177e4 LT |
1284 | */ |
1285 | int | |
ce8e922c NS |
1286 | xfs_buf_iowait( |
1287 | xfs_buf_t *bp) | |
1da177e4 | 1288 | { |
ce8e922c NS |
1289 | XB_TRACE(bp, "iowait", 0); |
1290 | if (atomic_read(&bp->b_io_remaining)) | |
1291 | blk_run_address_space(bp->b_target->bt_mapping); | |
1292 | down(&bp->b_iodonesema); | |
1293 | XB_TRACE(bp, "iowaited", (long)bp->b_error); | |
1294 | return bp->b_error; | |
1da177e4 LT |
1295 | } |
1296 | ||
ce8e922c NS |
1297 | xfs_caddr_t |
1298 | xfs_buf_offset( | |
1299 | xfs_buf_t *bp, | |
1da177e4 LT |
1300 | size_t offset) |
1301 | { | |
1302 | struct page *page; | |
1303 | ||
ce8e922c NS |
1304 | if (bp->b_flags & XBF_MAPPED) |
1305 | return XFS_BUF_PTR(bp) + offset; | |
1da177e4 | 1306 | |
ce8e922c NS |
1307 | offset += bp->b_offset; |
1308 | page = bp->b_pages[offset >> PAGE_CACHE_SHIFT]; | |
1309 | return (xfs_caddr_t)page_address(page) + (offset & (PAGE_CACHE_SIZE-1)); | |
1da177e4 LT |
1310 | } |
1311 | ||
1312 | /* | |
1da177e4 LT |
1313 | * Move data into or out of a buffer. |
1314 | */ | |
1315 | void | |
ce8e922c NS |
1316 | xfs_buf_iomove( |
1317 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1318 | size_t boff, /* starting buffer offset */ |
1319 | size_t bsize, /* length to copy */ | |
1320 | caddr_t data, /* data address */ | |
ce8e922c | 1321 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 LT |
1322 | { |
1323 | size_t bend, cpoff, csize; | |
1324 | struct page *page; | |
1325 | ||
1326 | bend = boff + bsize; | |
1327 | while (boff < bend) { | |
ce8e922c NS |
1328 | page = bp->b_pages[xfs_buf_btoct(boff + bp->b_offset)]; |
1329 | cpoff = xfs_buf_poff(boff + bp->b_offset); | |
1da177e4 | 1330 | csize = min_t(size_t, |
ce8e922c | 1331 | PAGE_CACHE_SIZE-cpoff, bp->b_count_desired-boff); |
1da177e4 LT |
1332 | |
1333 | ASSERT(((csize + cpoff) <= PAGE_CACHE_SIZE)); | |
1334 | ||
1335 | switch (mode) { | |
ce8e922c | 1336 | case XBRW_ZERO: |
1da177e4 LT |
1337 | memset(page_address(page) + cpoff, 0, csize); |
1338 | break; | |
ce8e922c | 1339 | case XBRW_READ: |
1da177e4 LT |
1340 | memcpy(data, page_address(page) + cpoff, csize); |
1341 | break; | |
ce8e922c | 1342 | case XBRW_WRITE: |
1da177e4 LT |
1343 | memcpy(page_address(page) + cpoff, data, csize); |
1344 | } | |
1345 | ||
1346 | boff += csize; | |
1347 | data += csize; | |
1348 | } | |
1349 | } | |
1350 | ||
1351 | /* | |
ce8e922c | 1352 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1353 | */ |
1354 | ||
1355 | /* | |
ce8e922c NS |
1356 | * Wait for any bufs with callbacks that have been submitted but |
1357 | * have not yet returned... walk the hash list for the target. | |
1da177e4 LT |
1358 | */ |
1359 | void | |
1360 | xfs_wait_buftarg( | |
1361 | xfs_buftarg_t *btp) | |
1362 | { | |
1363 | xfs_buf_t *bp, *n; | |
1364 | xfs_bufhash_t *hash; | |
1365 | uint i; | |
1366 | ||
1367 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { | |
1368 | hash = &btp->bt_hash[i]; | |
1369 | again: | |
1370 | spin_lock(&hash->bh_lock); | |
ce8e922c NS |
1371 | list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) { |
1372 | ASSERT(btp == bp->b_target); | |
1373 | if (!(bp->b_flags & XBF_FS_MANAGED)) { | |
1da177e4 | 1374 | spin_unlock(&hash->bh_lock); |
2f926587 DC |
1375 | /* |
1376 | * Catch superblock reference count leaks | |
1377 | * immediately | |
1378 | */ | |
ce8e922c | 1379 | BUG_ON(bp->b_bn == 0); |
1da177e4 LT |
1380 | delay(100); |
1381 | goto again; | |
1382 | } | |
1383 | } | |
1384 | spin_unlock(&hash->bh_lock); | |
1385 | } | |
1386 | } | |
1387 | ||
1388 | /* | |
ce8e922c NS |
1389 | * Allocate buffer hash table for a given target. |
1390 | * For devices containing metadata (i.e. not the log/realtime devices) | |
1391 | * we need to allocate a much larger hash table. | |
1da177e4 LT |
1392 | */ |
1393 | STATIC void | |
1394 | xfs_alloc_bufhash( | |
1395 | xfs_buftarg_t *btp, | |
1396 | int external) | |
1397 | { | |
1398 | unsigned int i; | |
1399 | ||
1400 | btp->bt_hashshift = external ? 3 : 8; /* 8 or 256 buckets */ | |
1401 | btp->bt_hashmask = (1 << btp->bt_hashshift) - 1; | |
1402 | btp->bt_hash = kmem_zalloc((1 << btp->bt_hashshift) * | |
1403 | sizeof(xfs_bufhash_t), KM_SLEEP); | |
1404 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { | |
1405 | spin_lock_init(&btp->bt_hash[i].bh_lock); | |
1406 | INIT_LIST_HEAD(&btp->bt_hash[i].bh_list); | |
1407 | } | |
1408 | } | |
1409 | ||
1410 | STATIC void | |
1411 | xfs_free_bufhash( | |
1412 | xfs_buftarg_t *btp) | |
1413 | { | |
ce8e922c | 1414 | kmem_free(btp->bt_hash, (1<<btp->bt_hashshift) * sizeof(xfs_bufhash_t)); |
1da177e4 LT |
1415 | btp->bt_hash = NULL; |
1416 | } | |
1417 | ||
a6867a68 | 1418 | /* |
ce8e922c | 1419 | * buftarg list for delwrite queue processing |
a6867a68 DC |
1420 | */ |
1421 | STATIC LIST_HEAD(xfs_buftarg_list); | |
1422 | STATIC DEFINE_SPINLOCK(xfs_buftarg_lock); | |
1423 | ||
1424 | STATIC void | |
1425 | xfs_register_buftarg( | |
1426 | xfs_buftarg_t *btp) | |
1427 | { | |
1428 | spin_lock(&xfs_buftarg_lock); | |
1429 | list_add(&btp->bt_list, &xfs_buftarg_list); | |
1430 | spin_unlock(&xfs_buftarg_lock); | |
1431 | } | |
1432 | ||
1433 | STATIC void | |
1434 | xfs_unregister_buftarg( | |
1435 | xfs_buftarg_t *btp) | |
1436 | { | |
1437 | spin_lock(&xfs_buftarg_lock); | |
1438 | list_del(&btp->bt_list); | |
1439 | spin_unlock(&xfs_buftarg_lock); | |
1440 | } | |
1441 | ||
1da177e4 LT |
1442 | void |
1443 | xfs_free_buftarg( | |
1444 | xfs_buftarg_t *btp, | |
1445 | int external) | |
1446 | { | |
1447 | xfs_flush_buftarg(btp, 1); | |
1448 | if (external) | |
ce8e922c | 1449 | xfs_blkdev_put(btp->bt_bdev); |
1da177e4 | 1450 | xfs_free_bufhash(btp); |
ce8e922c | 1451 | iput(btp->bt_mapping->host); |
a6867a68 | 1452 | |
ce8e922c NS |
1453 | /* Unregister the buftarg first so that we don't get a |
1454 | * wakeup finding a non-existent task | |
1455 | */ | |
a6867a68 DC |
1456 | xfs_unregister_buftarg(btp); |
1457 | kthread_stop(btp->bt_task); | |
1458 | ||
1da177e4 LT |
1459 | kmem_free(btp, sizeof(*btp)); |
1460 | } | |
1461 | ||
1da177e4 LT |
1462 | STATIC int |
1463 | xfs_setsize_buftarg_flags( | |
1464 | xfs_buftarg_t *btp, | |
1465 | unsigned int blocksize, | |
1466 | unsigned int sectorsize, | |
1467 | int verbose) | |
1468 | { | |
ce8e922c NS |
1469 | btp->bt_bsize = blocksize; |
1470 | btp->bt_sshift = ffs(sectorsize) - 1; | |
1471 | btp->bt_smask = sectorsize - 1; | |
1da177e4 | 1472 | |
ce8e922c | 1473 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
1da177e4 LT |
1474 | printk(KERN_WARNING |
1475 | "XFS: Cannot set_blocksize to %u on device %s\n", | |
1476 | sectorsize, XFS_BUFTARG_NAME(btp)); | |
1477 | return EINVAL; | |
1478 | } | |
1479 | ||
1480 | if (verbose && | |
1481 | (PAGE_CACHE_SIZE / BITS_PER_LONG) > sectorsize) { | |
1482 | printk(KERN_WARNING | |
1483 | "XFS: %u byte sectors in use on device %s. " | |
1484 | "This is suboptimal; %u or greater is ideal.\n", | |
1485 | sectorsize, XFS_BUFTARG_NAME(btp), | |
1486 | (unsigned int)PAGE_CACHE_SIZE / BITS_PER_LONG); | |
1487 | } | |
1488 | ||
1489 | return 0; | |
1490 | } | |
1491 | ||
1492 | /* | |
ce8e922c NS |
1493 | * When allocating the initial buffer target we have not yet |
1494 | * read in the superblock, so don't know what sized sectors | |
1495 | * are being used is at this early stage. Play safe. | |
1496 | */ | |
1da177e4 LT |
1497 | STATIC int |
1498 | xfs_setsize_buftarg_early( | |
1499 | xfs_buftarg_t *btp, | |
1500 | struct block_device *bdev) | |
1501 | { | |
1502 | return xfs_setsize_buftarg_flags(btp, | |
1503 | PAGE_CACHE_SIZE, bdev_hardsect_size(bdev), 0); | |
1504 | } | |
1505 | ||
1506 | int | |
1507 | xfs_setsize_buftarg( | |
1508 | xfs_buftarg_t *btp, | |
1509 | unsigned int blocksize, | |
1510 | unsigned int sectorsize) | |
1511 | { | |
1512 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | |
1513 | } | |
1514 | ||
1515 | STATIC int | |
1516 | xfs_mapping_buftarg( | |
1517 | xfs_buftarg_t *btp, | |
1518 | struct block_device *bdev) | |
1519 | { | |
1520 | struct backing_dev_info *bdi; | |
1521 | struct inode *inode; | |
1522 | struct address_space *mapping; | |
1523 | static struct address_space_operations mapping_aops = { | |
1524 | .sync_page = block_sync_page, | |
e965f963 | 1525 | .migratepage = fail_migrate_page, |
1da177e4 LT |
1526 | }; |
1527 | ||
1528 | inode = new_inode(bdev->bd_inode->i_sb); | |
1529 | if (!inode) { | |
1530 | printk(KERN_WARNING | |
1531 | "XFS: Cannot allocate mapping inode for device %s\n", | |
1532 | XFS_BUFTARG_NAME(btp)); | |
1533 | return ENOMEM; | |
1534 | } | |
1535 | inode->i_mode = S_IFBLK; | |
1536 | inode->i_bdev = bdev; | |
1537 | inode->i_rdev = bdev->bd_dev; | |
1538 | bdi = blk_get_backing_dev_info(bdev); | |
1539 | if (!bdi) | |
1540 | bdi = &default_backing_dev_info; | |
1541 | mapping = &inode->i_data; | |
1542 | mapping->a_ops = &mapping_aops; | |
1543 | mapping->backing_dev_info = bdi; | |
1544 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
ce8e922c | 1545 | btp->bt_mapping = mapping; |
1da177e4 LT |
1546 | return 0; |
1547 | } | |
1548 | ||
a6867a68 DC |
1549 | STATIC int |
1550 | xfs_alloc_delwrite_queue( | |
1551 | xfs_buftarg_t *btp) | |
1552 | { | |
1553 | int error = 0; | |
1554 | ||
1555 | INIT_LIST_HEAD(&btp->bt_list); | |
1556 | INIT_LIST_HEAD(&btp->bt_delwrite_queue); | |
1557 | spinlock_init(&btp->bt_delwrite_lock, "delwri_lock"); | |
1558 | btp->bt_flags = 0; | |
1559 | btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd"); | |
1560 | if (IS_ERR(btp->bt_task)) { | |
1561 | error = PTR_ERR(btp->bt_task); | |
1562 | goto out_error; | |
1563 | } | |
1564 | xfs_register_buftarg(btp); | |
1565 | out_error: | |
1566 | return error; | |
1567 | } | |
1568 | ||
1da177e4 LT |
1569 | xfs_buftarg_t * |
1570 | xfs_alloc_buftarg( | |
1571 | struct block_device *bdev, | |
1572 | int external) | |
1573 | { | |
1574 | xfs_buftarg_t *btp; | |
1575 | ||
1576 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP); | |
1577 | ||
ce8e922c NS |
1578 | btp->bt_dev = bdev->bd_dev; |
1579 | btp->bt_bdev = bdev; | |
1da177e4 LT |
1580 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1581 | goto error; | |
1582 | if (xfs_mapping_buftarg(btp, bdev)) | |
1583 | goto error; | |
a6867a68 DC |
1584 | if (xfs_alloc_delwrite_queue(btp)) |
1585 | goto error; | |
1da177e4 LT |
1586 | xfs_alloc_bufhash(btp, external); |
1587 | return btp; | |
1588 | ||
1589 | error: | |
1590 | kmem_free(btp, sizeof(*btp)); | |
1591 | return NULL; | |
1592 | } | |
1593 | ||
1594 | ||
1595 | /* | |
ce8e922c | 1596 | * Delayed write buffer handling |
1da177e4 | 1597 | */ |
1da177e4 | 1598 | STATIC void |
ce8e922c NS |
1599 | xfs_buf_delwri_queue( |
1600 | xfs_buf_t *bp, | |
1da177e4 LT |
1601 | int unlock) |
1602 | { | |
ce8e922c NS |
1603 | struct list_head *dwq = &bp->b_target->bt_delwrite_queue; |
1604 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; | |
a6867a68 | 1605 | |
ce8e922c NS |
1606 | XB_TRACE(bp, "delwri_q", (long)unlock); |
1607 | ASSERT((bp->b_flags&(XBF_DELWRI|XBF_ASYNC)) == (XBF_DELWRI|XBF_ASYNC)); | |
1da177e4 | 1608 | |
a6867a68 | 1609 | spin_lock(dwlk); |
1da177e4 | 1610 | /* If already in the queue, dequeue and place at tail */ |
ce8e922c NS |
1611 | if (!list_empty(&bp->b_list)) { |
1612 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1613 | if (unlock) | |
1614 | atomic_dec(&bp->b_hold); | |
1615 | list_del(&bp->b_list); | |
1da177e4 LT |
1616 | } |
1617 | ||
ce8e922c NS |
1618 | bp->b_flags |= _XBF_DELWRI_Q; |
1619 | list_add_tail(&bp->b_list, dwq); | |
1620 | bp->b_queuetime = jiffies; | |
a6867a68 | 1621 | spin_unlock(dwlk); |
1da177e4 LT |
1622 | |
1623 | if (unlock) | |
ce8e922c | 1624 | xfs_buf_unlock(bp); |
1da177e4 LT |
1625 | } |
1626 | ||
1627 | void | |
ce8e922c NS |
1628 | xfs_buf_delwri_dequeue( |
1629 | xfs_buf_t *bp) | |
1da177e4 | 1630 | { |
ce8e922c | 1631 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; |
1da177e4 LT |
1632 | int dequeued = 0; |
1633 | ||
a6867a68 | 1634 | spin_lock(dwlk); |
ce8e922c NS |
1635 | if ((bp->b_flags & XBF_DELWRI) && !list_empty(&bp->b_list)) { |
1636 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1637 | list_del_init(&bp->b_list); | |
1da177e4 LT |
1638 | dequeued = 1; |
1639 | } | |
ce8e922c | 1640 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); |
a6867a68 | 1641 | spin_unlock(dwlk); |
1da177e4 LT |
1642 | |
1643 | if (dequeued) | |
ce8e922c | 1644 | xfs_buf_rele(bp); |
1da177e4 | 1645 | |
ce8e922c | 1646 | XB_TRACE(bp, "delwri_dq", (long)dequeued); |
1da177e4 LT |
1647 | } |
1648 | ||
1649 | STATIC void | |
ce8e922c | 1650 | xfs_buf_runall_queues( |
1da177e4 LT |
1651 | struct workqueue_struct *queue) |
1652 | { | |
1653 | flush_workqueue(queue); | |
1654 | } | |
1655 | ||
1da177e4 | 1656 | STATIC int |
23ea4032 | 1657 | xfsbufd_wakeup( |
15c84a47 NS |
1658 | int priority, |
1659 | gfp_t mask) | |
1da177e4 | 1660 | { |
da7f93e9 | 1661 | xfs_buftarg_t *btp; |
a6867a68 DC |
1662 | |
1663 | spin_lock(&xfs_buftarg_lock); | |
da7f93e9 | 1664 | list_for_each_entry(btp, &xfs_buftarg_list, bt_list) { |
ce8e922c | 1665 | if (test_bit(XBT_FORCE_SLEEP, &btp->bt_flags)) |
a6867a68 | 1666 | continue; |
ce8e922c | 1667 | set_bit(XBT_FORCE_FLUSH, &btp->bt_flags); |
a6867a68 DC |
1668 | wake_up_process(btp->bt_task); |
1669 | } | |
1670 | spin_unlock(&xfs_buftarg_lock); | |
1da177e4 LT |
1671 | return 0; |
1672 | } | |
1673 | ||
1674 | STATIC int | |
23ea4032 | 1675 | xfsbufd( |
1da177e4 LT |
1676 | void *data) |
1677 | { | |
1678 | struct list_head tmp; | |
1679 | unsigned long age; | |
a6867a68 | 1680 | xfs_buftarg_t *target = (xfs_buftarg_t *)data; |
ce8e922c | 1681 | xfs_buf_t *bp, *n; |
a6867a68 DC |
1682 | struct list_head *dwq = &target->bt_delwrite_queue; |
1683 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1da177e4 | 1684 | |
1da177e4 LT |
1685 | current->flags |= PF_MEMALLOC; |
1686 | ||
1da177e4 LT |
1687 | INIT_LIST_HEAD(&tmp); |
1688 | do { | |
3e1d1d28 | 1689 | if (unlikely(freezing(current))) { |
ce8e922c | 1690 | set_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
3e1d1d28 | 1691 | refrigerator(); |
abd0cf7a | 1692 | } else { |
ce8e922c | 1693 | clear_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
abd0cf7a | 1694 | } |
1da177e4 | 1695 | |
15c84a47 NS |
1696 | schedule_timeout_interruptible( |
1697 | xfs_buf_timer_centisecs * msecs_to_jiffies(10)); | |
1da177e4 | 1698 | |
041e0e3b | 1699 | age = xfs_buf_age_centisecs * msecs_to_jiffies(10); |
a6867a68 | 1700 | spin_lock(dwlk); |
ce8e922c NS |
1701 | list_for_each_entry_safe(bp, n, dwq, b_list) { |
1702 | XB_TRACE(bp, "walkq1", (long)xfs_buf_ispin(bp)); | |
1703 | ASSERT(bp->b_flags & XBF_DELWRI); | |
1da177e4 | 1704 | |
ce8e922c NS |
1705 | if (!xfs_buf_ispin(bp) && !xfs_buf_cond_lock(bp)) { |
1706 | if (!test_bit(XBT_FORCE_FLUSH, | |
a6867a68 | 1707 | &target->bt_flags) && |
1da177e4 | 1708 | time_before(jiffies, |
ce8e922c NS |
1709 | bp->b_queuetime + age)) { |
1710 | xfs_buf_unlock(bp); | |
1da177e4 LT |
1711 | break; |
1712 | } | |
1713 | ||
ce8e922c NS |
1714 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); |
1715 | bp->b_flags |= XBF_WRITE; | |
1716 | list_move(&bp->b_list, &tmp); | |
1da177e4 LT |
1717 | } |
1718 | } | |
a6867a68 | 1719 | spin_unlock(dwlk); |
1da177e4 LT |
1720 | |
1721 | while (!list_empty(&tmp)) { | |
ce8e922c NS |
1722 | bp = list_entry(tmp.next, xfs_buf_t, b_list); |
1723 | ASSERT(target == bp->b_target); | |
1da177e4 | 1724 | |
ce8e922c NS |
1725 | list_del_init(&bp->b_list); |
1726 | xfs_buf_iostrategy(bp); | |
1da177e4 | 1727 | |
ce8e922c | 1728 | blk_run_address_space(target->bt_mapping); |
1da177e4 LT |
1729 | } |
1730 | ||
1731 | if (as_list_len > 0) | |
1732 | purge_addresses(); | |
1733 | ||
ce8e922c | 1734 | clear_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
4df08c52 | 1735 | } while (!kthread_should_stop()); |
1da177e4 | 1736 | |
4df08c52 | 1737 | return 0; |
1da177e4 LT |
1738 | } |
1739 | ||
1740 | /* | |
ce8e922c NS |
1741 | * Go through all incore buffers, and release buffers if they belong to |
1742 | * the given device. This is used in filesystem error handling to | |
1743 | * preserve the consistency of its metadata. | |
1da177e4 LT |
1744 | */ |
1745 | int | |
1746 | xfs_flush_buftarg( | |
1747 | xfs_buftarg_t *target, | |
1748 | int wait) | |
1749 | { | |
1750 | struct list_head tmp; | |
ce8e922c | 1751 | xfs_buf_t *bp, *n; |
1da177e4 | 1752 | int pincount = 0; |
a6867a68 DC |
1753 | struct list_head *dwq = &target->bt_delwrite_queue; |
1754 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1da177e4 | 1755 | |
ce8e922c NS |
1756 | xfs_buf_runall_queues(xfsdatad_workqueue); |
1757 | xfs_buf_runall_queues(xfslogd_workqueue); | |
1da177e4 LT |
1758 | |
1759 | INIT_LIST_HEAD(&tmp); | |
a6867a68 | 1760 | spin_lock(dwlk); |
ce8e922c NS |
1761 | list_for_each_entry_safe(bp, n, dwq, b_list) { |
1762 | ASSERT(bp->b_target == target); | |
1763 | ASSERT(bp->b_flags & (XBF_DELWRI | _XBF_DELWRI_Q)); | |
1764 | XB_TRACE(bp, "walkq2", (long)xfs_buf_ispin(bp)); | |
1765 | if (xfs_buf_ispin(bp)) { | |
1da177e4 LT |
1766 | pincount++; |
1767 | continue; | |
1768 | } | |
1769 | ||
ce8e922c | 1770 | list_move(&bp->b_list, &tmp); |
1da177e4 | 1771 | } |
a6867a68 | 1772 | spin_unlock(dwlk); |
1da177e4 LT |
1773 | |
1774 | /* | |
1775 | * Dropped the delayed write list lock, now walk the temporary list | |
1776 | */ | |
ce8e922c NS |
1777 | list_for_each_entry_safe(bp, n, &tmp, b_list) { |
1778 | xfs_buf_lock(bp); | |
1779 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); | |
1780 | bp->b_flags |= XBF_WRITE; | |
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 | ||
1789 | /* | |
1790 | * Remaining list items must be flushed before returning | |
1791 | */ | |
1792 | while (!list_empty(&tmp)) { | |
ce8e922c | 1793 | bp = list_entry(tmp.next, xfs_buf_t, b_list); |
1da177e4 | 1794 | |
ce8e922c NS |
1795 | list_del_init(&bp->b_list); |
1796 | xfs_iowait(bp); | |
1797 | xfs_buf_relse(bp); | |
1da177e4 LT |
1798 | } |
1799 | ||
1800 | if (wait) | |
ce8e922c | 1801 | blk_run_address_space(target->bt_mapping); |
1da177e4 LT |
1802 | |
1803 | return pincount; | |
1804 | } | |
1805 | ||
04d8b284 | 1806 | int __init |
ce8e922c | 1807 | xfs_buf_init(void) |
1da177e4 | 1808 | { |
ce8e922c NS |
1809 | #ifdef XFS_BUF_TRACE |
1810 | xfs_buf_trace_buf = ktrace_alloc(XFS_BUF_TRACE_SIZE, KM_SLEEP); | |
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 | ||
23ea4032 CH |
1818 | xfslogd_workqueue = create_workqueue("xfslogd"); |
1819 | if (!xfslogd_workqueue) | |
04d8b284 | 1820 | goto out_free_buf_zone; |
1da177e4 | 1821 | |
23ea4032 CH |
1822 | xfsdatad_workqueue = create_workqueue("xfsdatad"); |
1823 | if (!xfsdatad_workqueue) | |
1824 | goto out_destroy_xfslogd_workqueue; | |
1da177e4 | 1825 | |
ce8e922c NS |
1826 | xfs_buf_shake = kmem_shake_register(xfsbufd_wakeup); |
1827 | if (!xfs_buf_shake) | |
a6867a68 | 1828 | goto out_destroy_xfsdatad_workqueue; |
04d8b284 | 1829 | |
23ea4032 | 1830 | return 0; |
1da177e4 | 1831 | |
23ea4032 CH |
1832 | out_destroy_xfsdatad_workqueue: |
1833 | destroy_workqueue(xfsdatad_workqueue); | |
1834 | out_destroy_xfslogd_workqueue: | |
1835 | destroy_workqueue(xfslogd_workqueue); | |
23ea4032 | 1836 | out_free_buf_zone: |
ce8e922c | 1837 | kmem_zone_destroy(xfs_buf_zone); |
04d8b284 | 1838 | out_free_trace_buf: |
ce8e922c NS |
1839 | #ifdef XFS_BUF_TRACE |
1840 | ktrace_free(xfs_buf_trace_buf); | |
23ea4032 | 1841 | #endif |
8758280f | 1842 | return -ENOMEM; |
1da177e4 LT |
1843 | } |
1844 | ||
1da177e4 | 1845 | void |
ce8e922c | 1846 | xfs_buf_terminate(void) |
1da177e4 | 1847 | { |
ce8e922c | 1848 | kmem_shake_deregister(xfs_buf_shake); |
04d8b284 CH |
1849 | destroy_workqueue(xfsdatad_workqueue); |
1850 | destroy_workqueue(xfslogd_workqueue); | |
ce8e922c NS |
1851 | kmem_zone_destroy(xfs_buf_zone); |
1852 | #ifdef XFS_BUF_TRACE | |
1853 | ktrace_free(xfs_buf_trace_buf); | |
1da177e4 | 1854 | #endif |
1da177e4 | 1855 | } |