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 | */ |
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 | |
948ecdb4 NS |
321 | for (i = 0; i < bp->b_page_count; i++) { |
322 | struct page *page = bp->b_pages[i]; | |
323 | ||
324 | ASSERT(!PagePrivate(page)); | |
325 | page_cache_release(page); | |
326 | } | |
ce8e922c NS |
327 | _xfs_buf_free_pages(bp); |
328 | } else if (bp->b_flags & _XBF_KMEM_ALLOC) { | |
1da177e4 | 329 | /* |
ce8e922c NS |
330 | * XXX(hch): bp->b_count_desired might be incorrect (see |
331 | * xfs_buf_associate_memory for details), but fortunately | |
1da177e4 LT |
332 | * the Linux version of kmem_free ignores the len argument.. |
333 | */ | |
ce8e922c NS |
334 | kmem_free(bp->b_addr, bp->b_count_desired); |
335 | _xfs_buf_free_pages(bp); | |
1da177e4 LT |
336 | } |
337 | ||
ce8e922c | 338 | xfs_buf_deallocate(bp); |
1da177e4 LT |
339 | } |
340 | ||
341 | /* | |
342 | * Finds all pages for buffer in question and builds it's page list. | |
343 | */ | |
344 | STATIC int | |
ce8e922c | 345 | _xfs_buf_lookup_pages( |
1da177e4 LT |
346 | xfs_buf_t *bp, |
347 | uint flags) | |
348 | { | |
ce8e922c NS |
349 | struct address_space *mapping = bp->b_target->bt_mapping; |
350 | size_t blocksize = bp->b_target->bt_bsize; | |
351 | size_t size = bp->b_count_desired; | |
1da177e4 | 352 | size_t nbytes, offset; |
ce8e922c | 353 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 LT |
354 | unsigned short page_count, i; |
355 | pgoff_t first; | |
204ab25f | 356 | xfs_off_t end; |
1da177e4 LT |
357 | int error; |
358 | ||
ce8e922c NS |
359 | end = bp->b_file_offset + bp->b_buffer_length; |
360 | page_count = xfs_buf_btoc(end) - xfs_buf_btoct(bp->b_file_offset); | |
1da177e4 | 361 | |
ce8e922c | 362 | error = _xfs_buf_get_pages(bp, page_count, flags); |
1da177e4 LT |
363 | if (unlikely(error)) |
364 | return error; | |
ce8e922c | 365 | bp->b_flags |= _XBF_PAGE_CACHE; |
1da177e4 | 366 | |
ce8e922c NS |
367 | offset = bp->b_offset; |
368 | first = bp->b_file_offset >> PAGE_CACHE_SHIFT; | |
1da177e4 | 369 | |
ce8e922c | 370 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
371 | struct page *page; |
372 | uint retries = 0; | |
373 | ||
374 | retry: | |
375 | page = find_or_create_page(mapping, first + i, gfp_mask); | |
376 | if (unlikely(page == NULL)) { | |
ce8e922c NS |
377 | if (flags & XBF_READ_AHEAD) { |
378 | bp->b_page_count = i; | |
379 | for (i = 0; i < bp->b_page_count; i++) | |
380 | unlock_page(bp->b_pages[i]); | |
1da177e4 LT |
381 | return -ENOMEM; |
382 | } | |
383 | ||
384 | /* | |
385 | * This could deadlock. | |
386 | * | |
387 | * But until all the XFS lowlevel code is revamped to | |
388 | * handle buffer allocation failures we can't do much. | |
389 | */ | |
390 | if (!(++retries % 100)) | |
391 | printk(KERN_ERR | |
392 | "XFS: possible memory allocation " | |
393 | "deadlock in %s (mode:0x%x)\n", | |
394 | __FUNCTION__, gfp_mask); | |
395 | ||
ce8e922c | 396 | XFS_STATS_INC(xb_page_retries); |
23ea4032 | 397 | xfsbufd_wakeup(0, gfp_mask); |
1da177e4 LT |
398 | blk_congestion_wait(WRITE, HZ/50); |
399 | goto retry; | |
400 | } | |
401 | ||
ce8e922c | 402 | XFS_STATS_INC(xb_page_found); |
1da177e4 LT |
403 | |
404 | nbytes = min_t(size_t, size, PAGE_CACHE_SIZE - offset); | |
405 | size -= nbytes; | |
406 | ||
948ecdb4 | 407 | ASSERT(!PagePrivate(page)); |
1da177e4 LT |
408 | if (!PageUptodate(page)) { |
409 | page_count--; | |
410 | if (blocksize >= PAGE_CACHE_SIZE) { | |
ce8e922c NS |
411 | if (flags & XBF_READ) |
412 | bp->b_locked = 1; | |
1da177e4 LT |
413 | } else if (!PagePrivate(page)) { |
414 | if (test_page_region(page, offset, nbytes)) | |
415 | page_count++; | |
416 | } | |
417 | } | |
418 | ||
ce8e922c | 419 | bp->b_pages[i] = page; |
1da177e4 LT |
420 | offset = 0; |
421 | } | |
422 | ||
ce8e922c NS |
423 | if (!bp->b_locked) { |
424 | for (i = 0; i < bp->b_page_count; i++) | |
425 | unlock_page(bp->b_pages[i]); | |
1da177e4 LT |
426 | } |
427 | ||
ce8e922c NS |
428 | if (page_count == bp->b_page_count) |
429 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 430 | |
ce8e922c | 431 | XB_TRACE(bp, "lookup_pages", (long)page_count); |
1da177e4 LT |
432 | return error; |
433 | } | |
434 | ||
435 | /* | |
436 | * Map buffer into kernel address-space if nessecary. | |
437 | */ | |
438 | STATIC int | |
ce8e922c | 439 | _xfs_buf_map_pages( |
1da177e4 LT |
440 | xfs_buf_t *bp, |
441 | uint flags) | |
442 | { | |
443 | /* A single page buffer is always mappable */ | |
ce8e922c NS |
444 | if (bp->b_page_count == 1) { |
445 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; | |
446 | bp->b_flags |= XBF_MAPPED; | |
447 | } else if (flags & XBF_MAPPED) { | |
1da177e4 LT |
448 | if (as_list_len > 64) |
449 | purge_addresses(); | |
ce8e922c NS |
450 | bp->b_addr = vmap(bp->b_pages, bp->b_page_count, |
451 | VM_MAP, PAGE_KERNEL); | |
452 | if (unlikely(bp->b_addr == NULL)) | |
1da177e4 | 453 | return -ENOMEM; |
ce8e922c NS |
454 | bp->b_addr += bp->b_offset; |
455 | bp->b_flags |= XBF_MAPPED; | |
1da177e4 LT |
456 | } |
457 | ||
458 | return 0; | |
459 | } | |
460 | ||
461 | /* | |
462 | * Finding and Reading Buffers | |
463 | */ | |
464 | ||
465 | /* | |
ce8e922c | 466 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 LT |
467 | * a given range of an inode. The buffer is returned |
468 | * locked. If other overlapping buffers exist, they are | |
469 | * released before the new buffer is created and locked, | |
470 | * which may imply that this call will block until those buffers | |
471 | * are unlocked. No I/O is implied by this call. | |
472 | */ | |
473 | xfs_buf_t * | |
ce8e922c | 474 | _xfs_buf_find( |
1da177e4 | 475 | xfs_buftarg_t *btp, /* block device target */ |
204ab25f | 476 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 477 | size_t isize, /* length of range */ |
ce8e922c NS |
478 | xfs_buf_flags_t flags, |
479 | xfs_buf_t *new_bp) | |
1da177e4 | 480 | { |
204ab25f | 481 | xfs_off_t range_base; |
1da177e4 LT |
482 | size_t range_length; |
483 | xfs_bufhash_t *hash; | |
ce8e922c | 484 | xfs_buf_t *bp, *n; |
1da177e4 LT |
485 | |
486 | range_base = (ioff << BBSHIFT); | |
487 | range_length = (isize << BBSHIFT); | |
488 | ||
489 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
ce8e922c | 490 | ASSERT(!(range_length < (1 << btp->bt_sshift))); |
204ab25f | 491 | ASSERT(!(range_base & (xfs_off_t)btp->bt_smask)); |
1da177e4 LT |
492 | |
493 | hash = &btp->bt_hash[hash_long((unsigned long)ioff, btp->bt_hashshift)]; | |
494 | ||
495 | spin_lock(&hash->bh_lock); | |
496 | ||
ce8e922c NS |
497 | list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) { |
498 | ASSERT(btp == bp->b_target); | |
499 | if (bp->b_file_offset == range_base && | |
500 | bp->b_buffer_length == range_length) { | |
1da177e4 | 501 | /* |
ce8e922c | 502 | * If we look at something, bring it to the |
1da177e4 LT |
503 | * front of the list for next time. |
504 | */ | |
ce8e922c NS |
505 | atomic_inc(&bp->b_hold); |
506 | list_move(&bp->b_hash_list, &hash->bh_list); | |
1da177e4 LT |
507 | goto found; |
508 | } | |
509 | } | |
510 | ||
511 | /* No match found */ | |
ce8e922c NS |
512 | if (new_bp) { |
513 | _xfs_buf_initialize(new_bp, btp, range_base, | |
1da177e4 | 514 | range_length, flags); |
ce8e922c NS |
515 | new_bp->b_hash = hash; |
516 | list_add(&new_bp->b_hash_list, &hash->bh_list); | |
1da177e4 | 517 | } else { |
ce8e922c | 518 | XFS_STATS_INC(xb_miss_locked); |
1da177e4 LT |
519 | } |
520 | ||
521 | spin_unlock(&hash->bh_lock); | |
ce8e922c | 522 | return new_bp; |
1da177e4 LT |
523 | |
524 | found: | |
525 | spin_unlock(&hash->bh_lock); | |
526 | ||
527 | /* Attempt to get the semaphore without sleeping, | |
528 | * if this does not work then we need to drop the | |
529 | * spinlock and do a hard attempt on the semaphore. | |
530 | */ | |
ce8e922c NS |
531 | if (down_trylock(&bp->b_sema)) { |
532 | if (!(flags & XBF_TRYLOCK)) { | |
1da177e4 | 533 | /* wait for buffer ownership */ |
ce8e922c NS |
534 | XB_TRACE(bp, "get_lock", 0); |
535 | xfs_buf_lock(bp); | |
536 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 LT |
537 | } else { |
538 | /* We asked for a trylock and failed, no need | |
539 | * to look at file offset and length here, we | |
ce8e922c NS |
540 | * know that this buffer at least overlaps our |
541 | * buffer and is locked, therefore our buffer | |
542 | * either does not exist, or is this buffer. | |
1da177e4 | 543 | */ |
ce8e922c NS |
544 | xfs_buf_rele(bp); |
545 | XFS_STATS_INC(xb_busy_locked); | |
546 | return NULL; | |
1da177e4 LT |
547 | } |
548 | } else { | |
549 | /* trylock worked */ | |
ce8e922c | 550 | XB_SET_OWNER(bp); |
1da177e4 LT |
551 | } |
552 | ||
ce8e922c NS |
553 | if (bp->b_flags & XBF_STALE) { |
554 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
555 | bp->b_flags &= XBF_MAPPED; | |
2f926587 | 556 | } |
ce8e922c NS |
557 | XB_TRACE(bp, "got_lock", 0); |
558 | XFS_STATS_INC(xb_get_locked); | |
559 | return bp; | |
1da177e4 LT |
560 | } |
561 | ||
562 | /* | |
ce8e922c | 563 | * Assembles a buffer covering the specified range. |
1da177e4 LT |
564 | * Storage in memory for all portions of the buffer will be allocated, |
565 | * although backing storage may not be. | |
566 | */ | |
567 | xfs_buf_t * | |
ce8e922c | 568 | xfs_buf_get_flags( |
1da177e4 | 569 | xfs_buftarg_t *target,/* target for buffer */ |
204ab25f | 570 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 571 | size_t isize, /* length of range */ |
ce8e922c | 572 | xfs_buf_flags_t flags) |
1da177e4 | 573 | { |
ce8e922c | 574 | xfs_buf_t *bp, *new_bp; |
1da177e4 LT |
575 | int error = 0, i; |
576 | ||
ce8e922c NS |
577 | new_bp = xfs_buf_allocate(flags); |
578 | if (unlikely(!new_bp)) | |
1da177e4 LT |
579 | return NULL; |
580 | ||
ce8e922c NS |
581 | bp = _xfs_buf_find(target, ioff, isize, flags, new_bp); |
582 | if (bp == new_bp) { | |
583 | error = _xfs_buf_lookup_pages(bp, flags); | |
1da177e4 LT |
584 | if (error) |
585 | goto no_buffer; | |
586 | } else { | |
ce8e922c NS |
587 | xfs_buf_deallocate(new_bp); |
588 | if (unlikely(bp == NULL)) | |
1da177e4 LT |
589 | return NULL; |
590 | } | |
591 | ||
ce8e922c NS |
592 | for (i = 0; i < bp->b_page_count; i++) |
593 | mark_page_accessed(bp->b_pages[i]); | |
1da177e4 | 594 | |
ce8e922c NS |
595 | if (!(bp->b_flags & XBF_MAPPED)) { |
596 | error = _xfs_buf_map_pages(bp, flags); | |
1da177e4 LT |
597 | if (unlikely(error)) { |
598 | printk(KERN_WARNING "%s: failed to map pages\n", | |
599 | __FUNCTION__); | |
600 | goto no_buffer; | |
601 | } | |
602 | } | |
603 | ||
ce8e922c | 604 | XFS_STATS_INC(xb_get); |
1da177e4 LT |
605 | |
606 | /* | |
607 | * Always fill in the block number now, the mapped cases can do | |
608 | * their own overlay of this later. | |
609 | */ | |
ce8e922c NS |
610 | bp->b_bn = ioff; |
611 | bp->b_count_desired = bp->b_buffer_length; | |
1da177e4 | 612 | |
ce8e922c NS |
613 | XB_TRACE(bp, "get", (unsigned long)flags); |
614 | return bp; | |
1da177e4 LT |
615 | |
616 | no_buffer: | |
ce8e922c NS |
617 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
618 | xfs_buf_unlock(bp); | |
619 | xfs_buf_rele(bp); | |
1da177e4 LT |
620 | return NULL; |
621 | } | |
622 | ||
623 | xfs_buf_t * | |
624 | xfs_buf_read_flags( | |
625 | xfs_buftarg_t *target, | |
204ab25f | 626 | xfs_off_t ioff, |
1da177e4 | 627 | size_t isize, |
ce8e922c | 628 | xfs_buf_flags_t flags) |
1da177e4 | 629 | { |
ce8e922c NS |
630 | xfs_buf_t *bp; |
631 | ||
632 | flags |= XBF_READ; | |
633 | ||
634 | bp = xfs_buf_get_flags(target, ioff, isize, flags); | |
635 | if (bp) { | |
636 | if (!XFS_BUF_ISDONE(bp)) { | |
637 | XB_TRACE(bp, "read", (unsigned long)flags); | |
638 | XFS_STATS_INC(xb_get_read); | |
639 | xfs_buf_iostart(bp, flags); | |
640 | } else if (flags & XBF_ASYNC) { | |
641 | XB_TRACE(bp, "read_async", (unsigned long)flags); | |
1da177e4 LT |
642 | /* |
643 | * Read ahead call which is already satisfied, | |
644 | * drop the buffer | |
645 | */ | |
646 | goto no_buffer; | |
647 | } else { | |
ce8e922c | 648 | XB_TRACE(bp, "read_done", (unsigned long)flags); |
1da177e4 | 649 | /* We do not want read in the flags */ |
ce8e922c | 650 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
651 | } |
652 | } | |
653 | ||
ce8e922c | 654 | return bp; |
1da177e4 LT |
655 | |
656 | no_buffer: | |
ce8e922c NS |
657 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
658 | xfs_buf_unlock(bp); | |
659 | xfs_buf_rele(bp); | |
1da177e4 LT |
660 | return NULL; |
661 | } | |
662 | ||
1da177e4 | 663 | /* |
ce8e922c NS |
664 | * If we are not low on memory then do the readahead in a deadlock |
665 | * safe manner. | |
1da177e4 LT |
666 | */ |
667 | void | |
ce8e922c | 668 | xfs_buf_readahead( |
1da177e4 | 669 | xfs_buftarg_t *target, |
204ab25f | 670 | xfs_off_t ioff, |
1da177e4 | 671 | size_t isize, |
ce8e922c | 672 | xfs_buf_flags_t flags) |
1da177e4 LT |
673 | { |
674 | struct backing_dev_info *bdi; | |
675 | ||
ce8e922c | 676 | bdi = target->bt_mapping->backing_dev_info; |
1da177e4 LT |
677 | if (bdi_read_congested(bdi)) |
678 | return; | |
679 | ||
ce8e922c | 680 | flags |= (XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD); |
1da177e4 LT |
681 | xfs_buf_read_flags(target, ioff, isize, flags); |
682 | } | |
683 | ||
684 | xfs_buf_t * | |
ce8e922c | 685 | xfs_buf_get_empty( |
1da177e4 LT |
686 | size_t len, |
687 | xfs_buftarg_t *target) | |
688 | { | |
ce8e922c | 689 | xfs_buf_t *bp; |
1da177e4 | 690 | |
ce8e922c NS |
691 | bp = xfs_buf_allocate(0); |
692 | if (bp) | |
693 | _xfs_buf_initialize(bp, target, 0, len, 0); | |
694 | return bp; | |
1da177e4 LT |
695 | } |
696 | ||
697 | static inline struct page * | |
698 | mem_to_page( | |
699 | void *addr) | |
700 | { | |
701 | if (((unsigned long)addr < VMALLOC_START) || | |
702 | ((unsigned long)addr >= VMALLOC_END)) { | |
703 | return virt_to_page(addr); | |
704 | } else { | |
705 | return vmalloc_to_page(addr); | |
706 | } | |
707 | } | |
708 | ||
709 | int | |
ce8e922c NS |
710 | xfs_buf_associate_memory( |
711 | xfs_buf_t *bp, | |
1da177e4 LT |
712 | void *mem, |
713 | size_t len) | |
714 | { | |
715 | int rval; | |
716 | int i = 0; | |
717 | size_t ptr; | |
718 | size_t end, end_cur; | |
719 | off_t offset; | |
720 | int page_count; | |
721 | ||
722 | page_count = PAGE_CACHE_ALIGN(len) >> PAGE_CACHE_SHIFT; | |
723 | offset = (off_t) mem - ((off_t)mem & PAGE_CACHE_MASK); | |
724 | if (offset && (len > PAGE_CACHE_SIZE)) | |
725 | page_count++; | |
726 | ||
727 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
728 | if (bp->b_pages) |
729 | _xfs_buf_free_pages(bp); | |
1da177e4 | 730 | |
ce8e922c NS |
731 | bp->b_pages = NULL; |
732 | bp->b_addr = mem; | |
1da177e4 | 733 | |
ce8e922c | 734 | rval = _xfs_buf_get_pages(bp, page_count, 0); |
1da177e4 LT |
735 | if (rval) |
736 | return rval; | |
737 | ||
ce8e922c | 738 | bp->b_offset = offset; |
1da177e4 LT |
739 | ptr = (size_t) mem & PAGE_CACHE_MASK; |
740 | end = PAGE_CACHE_ALIGN((size_t) mem + len); | |
741 | end_cur = end; | |
742 | /* set up first page */ | |
ce8e922c | 743 | bp->b_pages[0] = mem_to_page(mem); |
1da177e4 LT |
744 | |
745 | ptr += PAGE_CACHE_SIZE; | |
ce8e922c | 746 | bp->b_page_count = ++i; |
1da177e4 | 747 | while (ptr < end) { |
ce8e922c NS |
748 | bp->b_pages[i] = mem_to_page((void *)ptr); |
749 | bp->b_page_count = ++i; | |
1da177e4 LT |
750 | ptr += PAGE_CACHE_SIZE; |
751 | } | |
ce8e922c | 752 | bp->b_locked = 0; |
1da177e4 | 753 | |
ce8e922c NS |
754 | bp->b_count_desired = bp->b_buffer_length = len; |
755 | bp->b_flags |= XBF_MAPPED; | |
1da177e4 LT |
756 | |
757 | return 0; | |
758 | } | |
759 | ||
760 | xfs_buf_t * | |
ce8e922c | 761 | xfs_buf_get_noaddr( |
1da177e4 LT |
762 | size_t len, |
763 | xfs_buftarg_t *target) | |
764 | { | |
765 | size_t malloc_len = len; | |
766 | xfs_buf_t *bp; | |
767 | void *data; | |
768 | int error; | |
769 | ||
ce8e922c | 770 | bp = xfs_buf_allocate(0); |
1da177e4 LT |
771 | if (unlikely(bp == NULL)) |
772 | goto fail; | |
ce8e922c | 773 | _xfs_buf_initialize(bp, target, 0, len, 0); |
1da177e4 LT |
774 | |
775 | try_again: | |
efb8ad7e | 776 | data = kmem_alloc(malloc_len, KM_SLEEP | KM_MAYFAIL | KM_LARGE); |
1da177e4 LT |
777 | if (unlikely(data == NULL)) |
778 | goto fail_free_buf; | |
779 | ||
780 | /* check whether alignment matches.. */ | |
781 | if ((__psunsigned_t)data != | |
ce8e922c | 782 | ((__psunsigned_t)data & ~target->bt_smask)) { |
1da177e4 LT |
783 | /* .. else double the size and try again */ |
784 | kmem_free(data, malloc_len); | |
785 | malloc_len <<= 1; | |
786 | goto try_again; | |
787 | } | |
788 | ||
ce8e922c | 789 | error = xfs_buf_associate_memory(bp, data, len); |
1da177e4 LT |
790 | if (error) |
791 | goto fail_free_mem; | |
ce8e922c | 792 | bp->b_flags |= _XBF_KMEM_ALLOC; |
1da177e4 | 793 | |
ce8e922c | 794 | xfs_buf_unlock(bp); |
1da177e4 | 795 | |
ce8e922c | 796 | XB_TRACE(bp, "no_daddr", data); |
1da177e4 LT |
797 | return bp; |
798 | fail_free_mem: | |
799 | kmem_free(data, malloc_len); | |
800 | fail_free_buf: | |
ce8e922c | 801 | xfs_buf_free(bp); |
1da177e4 LT |
802 | fail: |
803 | return NULL; | |
804 | } | |
805 | ||
806 | /* | |
1da177e4 LT |
807 | * Increment reference count on buffer, to hold the buffer concurrently |
808 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
809 | * Must hold the buffer already to call this function. |
810 | */ | |
811 | void | |
ce8e922c NS |
812 | xfs_buf_hold( |
813 | xfs_buf_t *bp) | |
1da177e4 | 814 | { |
ce8e922c NS |
815 | atomic_inc(&bp->b_hold); |
816 | XB_TRACE(bp, "hold", 0); | |
1da177e4 LT |
817 | } |
818 | ||
819 | /* | |
ce8e922c NS |
820 | * Releases a hold on the specified buffer. If the |
821 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
822 | */ |
823 | void | |
ce8e922c NS |
824 | xfs_buf_rele( |
825 | xfs_buf_t *bp) | |
1da177e4 | 826 | { |
ce8e922c | 827 | xfs_bufhash_t *hash = bp->b_hash; |
1da177e4 | 828 | |
ce8e922c | 829 | XB_TRACE(bp, "rele", bp->b_relse); |
1da177e4 | 830 | |
fad3aa1e NS |
831 | if (unlikely(!hash)) { |
832 | ASSERT(!bp->b_relse); | |
833 | if (atomic_dec_and_test(&bp->b_hold)) | |
834 | xfs_buf_free(bp); | |
835 | return; | |
836 | } | |
837 | ||
ce8e922c NS |
838 | if (atomic_dec_and_lock(&bp->b_hold, &hash->bh_lock)) { |
839 | if (bp->b_relse) { | |
840 | atomic_inc(&bp->b_hold); | |
1da177e4 | 841 | spin_unlock(&hash->bh_lock); |
ce8e922c NS |
842 | (*(bp->b_relse)) (bp); |
843 | } else if (bp->b_flags & XBF_FS_MANAGED) { | |
1da177e4 | 844 | spin_unlock(&hash->bh_lock); |
1da177e4 | 845 | } else { |
ce8e922c NS |
846 | ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q))); |
847 | list_del_init(&bp->b_hash_list); | |
1da177e4 | 848 | spin_unlock(&hash->bh_lock); |
ce8e922c | 849 | xfs_buf_free(bp); |
1da177e4 | 850 | } |
2f926587 DC |
851 | } else { |
852 | /* | |
853 | * Catch reference count leaks | |
854 | */ | |
ce8e922c | 855 | ASSERT(atomic_read(&bp->b_hold) >= 0); |
1da177e4 LT |
856 | } |
857 | } | |
858 | ||
859 | ||
860 | /* | |
861 | * Mutual exclusion on buffers. Locking model: | |
862 | * | |
863 | * Buffers associated with inodes for which buffer locking | |
864 | * is not enabled are not protected by semaphores, and are | |
865 | * assumed to be exclusively owned by the caller. There is a | |
866 | * spinlock in the buffer, used by the caller when concurrent | |
867 | * access is possible. | |
868 | */ | |
869 | ||
870 | /* | |
ce8e922c NS |
871 | * Locks a buffer object, if it is not already locked. |
872 | * Note that this in no way locks the underlying pages, so it is only | |
873 | * useful for synchronizing concurrent use of buffer objects, not for | |
874 | * synchronizing independent access to the underlying pages. | |
1da177e4 LT |
875 | */ |
876 | int | |
ce8e922c NS |
877 | xfs_buf_cond_lock( |
878 | xfs_buf_t *bp) | |
1da177e4 LT |
879 | { |
880 | int locked; | |
881 | ||
ce8e922c | 882 | locked = down_trylock(&bp->b_sema) == 0; |
1da177e4 | 883 | if (locked) { |
ce8e922c | 884 | XB_SET_OWNER(bp); |
1da177e4 | 885 | } |
ce8e922c NS |
886 | XB_TRACE(bp, "cond_lock", (long)locked); |
887 | return locked ? 0 : -EBUSY; | |
1da177e4 LT |
888 | } |
889 | ||
890 | #if defined(DEBUG) || defined(XFS_BLI_TRACE) | |
1da177e4 | 891 | int |
ce8e922c NS |
892 | xfs_buf_lock_value( |
893 | xfs_buf_t *bp) | |
1da177e4 | 894 | { |
ce8e922c | 895 | return atomic_read(&bp->b_sema.count); |
1da177e4 LT |
896 | } |
897 | #endif | |
898 | ||
899 | /* | |
ce8e922c NS |
900 | * Locks a buffer object. |
901 | * Note that this in no way locks the underlying pages, so it is only | |
902 | * useful for synchronizing concurrent use of buffer objects, not for | |
903 | * synchronizing independent access to the underlying pages. | |
1da177e4 | 904 | */ |
ce8e922c NS |
905 | void |
906 | xfs_buf_lock( | |
907 | xfs_buf_t *bp) | |
1da177e4 | 908 | { |
ce8e922c NS |
909 | XB_TRACE(bp, "lock", 0); |
910 | if (atomic_read(&bp->b_io_remaining)) | |
911 | blk_run_address_space(bp->b_target->bt_mapping); | |
912 | down(&bp->b_sema); | |
913 | XB_SET_OWNER(bp); | |
914 | XB_TRACE(bp, "locked", 0); | |
1da177e4 LT |
915 | } |
916 | ||
917 | /* | |
ce8e922c | 918 | * Releases the lock on the buffer object. |
2f926587 | 919 | * If the buffer is marked delwri but is not queued, do so before we |
ce8e922c | 920 | * unlock the buffer as we need to set flags correctly. We also need to |
2f926587 DC |
921 | * take a reference for the delwri queue because the unlocker is going to |
922 | * drop their's and they don't know we just queued it. | |
1da177e4 LT |
923 | */ |
924 | void | |
ce8e922c NS |
925 | xfs_buf_unlock( |
926 | xfs_buf_t *bp) | |
1da177e4 | 927 | { |
ce8e922c NS |
928 | if ((bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)) == XBF_DELWRI) { |
929 | atomic_inc(&bp->b_hold); | |
930 | bp->b_flags |= XBF_ASYNC; | |
931 | xfs_buf_delwri_queue(bp, 0); | |
2f926587 DC |
932 | } |
933 | ||
ce8e922c NS |
934 | XB_CLEAR_OWNER(bp); |
935 | up(&bp->b_sema); | |
936 | XB_TRACE(bp, "unlock", 0); | |
1da177e4 LT |
937 | } |
938 | ||
939 | ||
940 | /* | |
941 | * Pinning Buffer Storage in Memory | |
ce8e922c | 942 | * Ensure that no attempt to force a buffer to disk will succeed. |
1da177e4 LT |
943 | */ |
944 | void | |
ce8e922c NS |
945 | xfs_buf_pin( |
946 | xfs_buf_t *bp) | |
1da177e4 | 947 | { |
ce8e922c NS |
948 | atomic_inc(&bp->b_pin_count); |
949 | XB_TRACE(bp, "pin", (long)bp->b_pin_count.counter); | |
1da177e4 LT |
950 | } |
951 | ||
1da177e4 | 952 | void |
ce8e922c NS |
953 | xfs_buf_unpin( |
954 | xfs_buf_t *bp) | |
1da177e4 | 955 | { |
ce8e922c NS |
956 | if (atomic_dec_and_test(&bp->b_pin_count)) |
957 | wake_up_all(&bp->b_waiters); | |
958 | XB_TRACE(bp, "unpin", (long)bp->b_pin_count.counter); | |
1da177e4 LT |
959 | } |
960 | ||
961 | int | |
ce8e922c NS |
962 | xfs_buf_ispin( |
963 | xfs_buf_t *bp) | |
1da177e4 | 964 | { |
ce8e922c | 965 | return atomic_read(&bp->b_pin_count); |
1da177e4 LT |
966 | } |
967 | ||
ce8e922c NS |
968 | STATIC void |
969 | xfs_buf_wait_unpin( | |
970 | xfs_buf_t *bp) | |
1da177e4 LT |
971 | { |
972 | DECLARE_WAITQUEUE (wait, current); | |
973 | ||
ce8e922c | 974 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
975 | return; |
976 | ||
ce8e922c | 977 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
978 | for (;;) { |
979 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 980 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 981 | break; |
ce8e922c NS |
982 | if (atomic_read(&bp->b_io_remaining)) |
983 | blk_run_address_space(bp->b_target->bt_mapping); | |
1da177e4 LT |
984 | schedule(); |
985 | } | |
ce8e922c | 986 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
987 | set_current_state(TASK_RUNNING); |
988 | } | |
989 | ||
990 | /* | |
991 | * Buffer Utility Routines | |
992 | */ | |
993 | ||
1da177e4 | 994 | STATIC void |
ce8e922c | 995 | xfs_buf_iodone_work( |
1da177e4 LT |
996 | void *v) |
997 | { | |
998 | xfs_buf_t *bp = (xfs_buf_t *)v; | |
999 | ||
ce8e922c NS |
1000 | if (bp->b_iodone) |
1001 | (*(bp->b_iodone))(bp); | |
1002 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 LT |
1003 | xfs_buf_relse(bp); |
1004 | } | |
1005 | ||
1006 | void | |
ce8e922c NS |
1007 | xfs_buf_ioend( |
1008 | xfs_buf_t *bp, | |
1da177e4 LT |
1009 | int schedule) |
1010 | { | |
ce8e922c NS |
1011 | bp->b_flags &= ~(XBF_READ | XBF_WRITE); |
1012 | if (bp->b_error == 0) | |
1013 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1014 | |
ce8e922c | 1015 | XB_TRACE(bp, "iodone", bp->b_iodone); |
1da177e4 | 1016 | |
ce8e922c | 1017 | if ((bp->b_iodone) || (bp->b_flags & XBF_ASYNC)) { |
1da177e4 | 1018 | if (schedule) { |
ce8e922c NS |
1019 | INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work, bp); |
1020 | queue_work(xfslogd_workqueue, &bp->b_iodone_work); | |
1da177e4 | 1021 | } else { |
ce8e922c | 1022 | xfs_buf_iodone_work(bp); |
1da177e4 LT |
1023 | } |
1024 | } else { | |
ce8e922c | 1025 | up(&bp->b_iodonesema); |
1da177e4 LT |
1026 | } |
1027 | } | |
1028 | ||
1da177e4 | 1029 | void |
ce8e922c NS |
1030 | xfs_buf_ioerror( |
1031 | xfs_buf_t *bp, | |
1032 | int error) | |
1da177e4 LT |
1033 | { |
1034 | ASSERT(error >= 0 && error <= 0xffff); | |
ce8e922c NS |
1035 | bp->b_error = (unsigned short)error; |
1036 | XB_TRACE(bp, "ioerror", (unsigned long)error); | |
1da177e4 LT |
1037 | } |
1038 | ||
1039 | /* | |
ce8e922c NS |
1040 | * Initiate I/O on a buffer, based on the flags supplied. |
1041 | * The b_iodone routine in the buffer supplied will only be called | |
1da177e4 | 1042 | * when all of the subsidiary I/O requests, if any, have been completed. |
1da177e4 LT |
1043 | */ |
1044 | int | |
ce8e922c NS |
1045 | xfs_buf_iostart( |
1046 | xfs_buf_t *bp, | |
1047 | xfs_buf_flags_t flags) | |
1da177e4 LT |
1048 | { |
1049 | int status = 0; | |
1050 | ||
ce8e922c | 1051 | XB_TRACE(bp, "iostart", (unsigned long)flags); |
1da177e4 | 1052 | |
ce8e922c NS |
1053 | if (flags & XBF_DELWRI) { |
1054 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_ASYNC); | |
1055 | bp->b_flags |= flags & (XBF_DELWRI | XBF_ASYNC); | |
1056 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1057 | return status; |
1058 | } | |
1059 | ||
ce8e922c NS |
1060 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_ASYNC | XBF_DELWRI | \ |
1061 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
1062 | bp->b_flags |= flags & (XBF_READ | XBF_WRITE | XBF_ASYNC | \ | |
1063 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
1da177e4 | 1064 | |
ce8e922c | 1065 | BUG_ON(bp->b_bn == XFS_BUF_DADDR_NULL); |
1da177e4 LT |
1066 | |
1067 | /* For writes allow an alternate strategy routine to precede | |
1068 | * the actual I/O request (which may not be issued at all in | |
1069 | * a shutdown situation, for example). | |
1070 | */ | |
ce8e922c NS |
1071 | status = (flags & XBF_WRITE) ? |
1072 | xfs_buf_iostrategy(bp) : xfs_buf_iorequest(bp); | |
1da177e4 LT |
1073 | |
1074 | /* Wait for I/O if we are not an async request. | |
1075 | * Note: async I/O request completion will release the buffer, | |
1076 | * and that can already be done by this point. So using the | |
1077 | * buffer pointer from here on, after async I/O, is invalid. | |
1078 | */ | |
ce8e922c NS |
1079 | if (!status && !(flags & XBF_ASYNC)) |
1080 | status = xfs_buf_iowait(bp); | |
1da177e4 LT |
1081 | |
1082 | return status; | |
1083 | } | |
1084 | ||
1da177e4 | 1085 | STATIC __inline__ int |
ce8e922c NS |
1086 | _xfs_buf_iolocked( |
1087 | xfs_buf_t *bp) | |
1da177e4 | 1088 | { |
ce8e922c NS |
1089 | ASSERT(bp->b_flags & (XBF_READ | XBF_WRITE)); |
1090 | if (bp->b_flags & XBF_READ) | |
1091 | return bp->b_locked; | |
1da177e4 LT |
1092 | return 0; |
1093 | } | |
1094 | ||
1095 | STATIC __inline__ void | |
ce8e922c NS |
1096 | _xfs_buf_ioend( |
1097 | xfs_buf_t *bp, | |
1da177e4 LT |
1098 | int schedule) |
1099 | { | |
ce8e922c NS |
1100 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) { |
1101 | bp->b_locked = 0; | |
1102 | xfs_buf_ioend(bp, schedule); | |
1da177e4 LT |
1103 | } |
1104 | } | |
1105 | ||
1106 | STATIC int | |
ce8e922c | 1107 | xfs_buf_bio_end_io( |
1da177e4 LT |
1108 | struct bio *bio, |
1109 | unsigned int bytes_done, | |
1110 | int error) | |
1111 | { | |
ce8e922c NS |
1112 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1113 | unsigned int blocksize = bp->b_target->bt_bsize; | |
eedb5530 | 1114 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; |
1da177e4 LT |
1115 | |
1116 | if (bio->bi_size) | |
1117 | return 1; | |
1118 | ||
1119 | if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) | |
ce8e922c | 1120 | bp->b_error = EIO; |
1da177e4 | 1121 | |
eedb5530 | 1122 | do { |
1da177e4 LT |
1123 | struct page *page = bvec->bv_page; |
1124 | ||
948ecdb4 | 1125 | ASSERT(!PagePrivate(page)); |
ce8e922c NS |
1126 | if (unlikely(bp->b_error)) { |
1127 | if (bp->b_flags & XBF_READ) | |
eedb5530 | 1128 | ClearPageUptodate(page); |
ce8e922c | 1129 | } else if (blocksize >= PAGE_CACHE_SIZE) { |
1da177e4 LT |
1130 | SetPageUptodate(page); |
1131 | } else if (!PagePrivate(page) && | |
ce8e922c | 1132 | (bp->b_flags & _XBF_PAGE_CACHE)) { |
1da177e4 LT |
1133 | set_page_region(page, bvec->bv_offset, bvec->bv_len); |
1134 | } | |
1135 | ||
eedb5530 NS |
1136 | if (--bvec >= bio->bi_io_vec) |
1137 | prefetchw(&bvec->bv_page->flags); | |
1138 | ||
ce8e922c | 1139 | if (_xfs_buf_iolocked(bp)) { |
1da177e4 LT |
1140 | unlock_page(page); |
1141 | } | |
eedb5530 | 1142 | } while (bvec >= bio->bi_io_vec); |
1da177e4 | 1143 | |
ce8e922c | 1144 | _xfs_buf_ioend(bp, 1); |
1da177e4 LT |
1145 | bio_put(bio); |
1146 | return 0; | |
1147 | } | |
1148 | ||
1149 | STATIC void | |
ce8e922c NS |
1150 | _xfs_buf_ioapply( |
1151 | xfs_buf_t *bp) | |
1da177e4 LT |
1152 | { |
1153 | int i, rw, map_i, total_nr_pages, nr_pages; | |
1154 | struct bio *bio; | |
ce8e922c NS |
1155 | int offset = bp->b_offset; |
1156 | int size = bp->b_count_desired; | |
1157 | sector_t sector = bp->b_bn; | |
1158 | unsigned int blocksize = bp->b_target->bt_bsize; | |
1159 | int locking = _xfs_buf_iolocked(bp); | |
1da177e4 | 1160 | |
ce8e922c | 1161 | total_nr_pages = bp->b_page_count; |
1da177e4 LT |
1162 | map_i = 0; |
1163 | ||
ce8e922c NS |
1164 | if (bp->b_flags & XBF_ORDERED) { |
1165 | ASSERT(!(bp->b_flags & XBF_READ)); | |
f538d4da | 1166 | rw = WRITE_BARRIER; |
51bdd706 NS |
1167 | } else if (bp->b_flags & _XBF_RUN_QUEUES) { |
1168 | ASSERT(!(bp->b_flags & XBF_READ_AHEAD)); | |
1169 | bp->b_flags &= ~_XBF_RUN_QUEUES; | |
1170 | rw = (bp->b_flags & XBF_WRITE) ? WRITE_SYNC : READ_SYNC; | |
1171 | } else { | |
1172 | rw = (bp->b_flags & XBF_WRITE) ? WRITE : | |
1173 | (bp->b_flags & XBF_READ_AHEAD) ? READA : READ; | |
f538d4da CH |
1174 | } |
1175 | ||
ce8e922c | 1176 | /* Special code path for reading a sub page size buffer in -- |
1da177e4 LT |
1177 | * we populate up the whole page, and hence the other metadata |
1178 | * in the same page. This optimization is only valid when the | |
ce8e922c | 1179 | * filesystem block size is not smaller than the page size. |
1da177e4 | 1180 | */ |
ce8e922c NS |
1181 | if ((bp->b_buffer_length < PAGE_CACHE_SIZE) && |
1182 | (bp->b_flags & XBF_READ) && locking && | |
1183 | (blocksize >= PAGE_CACHE_SIZE)) { | |
1da177e4 LT |
1184 | bio = bio_alloc(GFP_NOIO, 1); |
1185 | ||
ce8e922c | 1186 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1187 | bio->bi_sector = sector - (offset >> BBSHIFT); |
ce8e922c NS |
1188 | bio->bi_end_io = xfs_buf_bio_end_io; |
1189 | bio->bi_private = bp; | |
1da177e4 | 1190 | |
ce8e922c | 1191 | bio_add_page(bio, bp->b_pages[0], PAGE_CACHE_SIZE, 0); |
1da177e4 LT |
1192 | size = 0; |
1193 | ||
ce8e922c | 1194 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1195 | |
1196 | goto submit_io; | |
1197 | } | |
1198 | ||
1199 | /* Lock down the pages which we need to for the request */ | |
ce8e922c | 1200 | if (locking && (bp->b_flags & XBF_WRITE) && (bp->b_locked == 0)) { |
1da177e4 LT |
1201 | for (i = 0; size; i++) { |
1202 | int nbytes = PAGE_CACHE_SIZE - offset; | |
ce8e922c | 1203 | struct page *page = bp->b_pages[i]; |
1da177e4 LT |
1204 | |
1205 | if (nbytes > size) | |
1206 | nbytes = size; | |
1207 | ||
1208 | lock_page(page); | |
1209 | ||
1210 | size -= nbytes; | |
1211 | offset = 0; | |
1212 | } | |
ce8e922c NS |
1213 | offset = bp->b_offset; |
1214 | size = bp->b_count_desired; | |
1da177e4 LT |
1215 | } |
1216 | ||
1217 | next_chunk: | |
ce8e922c | 1218 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1219 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1220 | if (nr_pages > total_nr_pages) | |
1221 | nr_pages = total_nr_pages; | |
1222 | ||
1223 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1224 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1225 | bio->bi_sector = sector; |
ce8e922c NS |
1226 | bio->bi_end_io = xfs_buf_bio_end_io; |
1227 | bio->bi_private = bp; | |
1da177e4 LT |
1228 | |
1229 | for (; size && nr_pages; nr_pages--, map_i++) { | |
ce8e922c | 1230 | int rbytes, nbytes = PAGE_CACHE_SIZE - offset; |
1da177e4 LT |
1231 | |
1232 | if (nbytes > size) | |
1233 | nbytes = size; | |
1234 | ||
ce8e922c NS |
1235 | rbytes = bio_add_page(bio, bp->b_pages[map_i], nbytes, offset); |
1236 | if (rbytes < nbytes) | |
1da177e4 LT |
1237 | break; |
1238 | ||
1239 | offset = 0; | |
1240 | sector += nbytes >> BBSHIFT; | |
1241 | size -= nbytes; | |
1242 | total_nr_pages--; | |
1243 | } | |
1244 | ||
1245 | submit_io: | |
1246 | if (likely(bio->bi_size)) { | |
1247 | submit_bio(rw, bio); | |
1248 | if (size) | |
1249 | goto next_chunk; | |
1250 | } else { | |
1251 | bio_put(bio); | |
ce8e922c | 1252 | xfs_buf_ioerror(bp, EIO); |
1da177e4 LT |
1253 | } |
1254 | } | |
1255 | ||
1da177e4 | 1256 | int |
ce8e922c NS |
1257 | xfs_buf_iorequest( |
1258 | xfs_buf_t *bp) | |
1da177e4 | 1259 | { |
ce8e922c | 1260 | XB_TRACE(bp, "iorequest", 0); |
1da177e4 | 1261 | |
ce8e922c NS |
1262 | if (bp->b_flags & XBF_DELWRI) { |
1263 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1264 | return 0; |
1265 | } | |
1266 | ||
ce8e922c NS |
1267 | if (bp->b_flags & XBF_WRITE) { |
1268 | xfs_buf_wait_unpin(bp); | |
1da177e4 LT |
1269 | } |
1270 | ||
ce8e922c | 1271 | xfs_buf_hold(bp); |
1da177e4 LT |
1272 | |
1273 | /* Set the count to 1 initially, this will stop an I/O | |
1274 | * completion callout which happens before we have started | |
ce8e922c | 1275 | * all the I/O from calling xfs_buf_ioend too early. |
1da177e4 | 1276 | */ |
ce8e922c NS |
1277 | atomic_set(&bp->b_io_remaining, 1); |
1278 | _xfs_buf_ioapply(bp); | |
1279 | _xfs_buf_ioend(bp, 0); | |
1da177e4 | 1280 | |
ce8e922c | 1281 | xfs_buf_rele(bp); |
1da177e4 LT |
1282 | return 0; |
1283 | } | |
1284 | ||
1285 | /* | |
ce8e922c NS |
1286 | * Waits for I/O to complete on the buffer supplied. |
1287 | * It returns immediately if no I/O is pending. | |
1288 | * It returns the I/O error code, if any, or 0 if there was no error. | |
1da177e4 LT |
1289 | */ |
1290 | int | |
ce8e922c NS |
1291 | xfs_buf_iowait( |
1292 | xfs_buf_t *bp) | |
1da177e4 | 1293 | { |
ce8e922c NS |
1294 | XB_TRACE(bp, "iowait", 0); |
1295 | if (atomic_read(&bp->b_io_remaining)) | |
1296 | blk_run_address_space(bp->b_target->bt_mapping); | |
1297 | down(&bp->b_iodonesema); | |
1298 | XB_TRACE(bp, "iowaited", (long)bp->b_error); | |
1299 | return bp->b_error; | |
1da177e4 LT |
1300 | } |
1301 | ||
ce8e922c NS |
1302 | xfs_caddr_t |
1303 | xfs_buf_offset( | |
1304 | xfs_buf_t *bp, | |
1da177e4 LT |
1305 | size_t offset) |
1306 | { | |
1307 | struct page *page; | |
1308 | ||
ce8e922c NS |
1309 | if (bp->b_flags & XBF_MAPPED) |
1310 | return XFS_BUF_PTR(bp) + offset; | |
1da177e4 | 1311 | |
ce8e922c NS |
1312 | offset += bp->b_offset; |
1313 | page = bp->b_pages[offset >> PAGE_CACHE_SHIFT]; | |
1314 | return (xfs_caddr_t)page_address(page) + (offset & (PAGE_CACHE_SIZE-1)); | |
1da177e4 LT |
1315 | } |
1316 | ||
1317 | /* | |
1da177e4 LT |
1318 | * Move data into or out of a buffer. |
1319 | */ | |
1320 | void | |
ce8e922c NS |
1321 | xfs_buf_iomove( |
1322 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1323 | size_t boff, /* starting buffer offset */ |
1324 | size_t bsize, /* length to copy */ | |
1325 | caddr_t data, /* data address */ | |
ce8e922c | 1326 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 LT |
1327 | { |
1328 | size_t bend, cpoff, csize; | |
1329 | struct page *page; | |
1330 | ||
1331 | bend = boff + bsize; | |
1332 | while (boff < bend) { | |
ce8e922c NS |
1333 | page = bp->b_pages[xfs_buf_btoct(boff + bp->b_offset)]; |
1334 | cpoff = xfs_buf_poff(boff + bp->b_offset); | |
1da177e4 | 1335 | csize = min_t(size_t, |
ce8e922c | 1336 | PAGE_CACHE_SIZE-cpoff, bp->b_count_desired-boff); |
1da177e4 LT |
1337 | |
1338 | ASSERT(((csize + cpoff) <= PAGE_CACHE_SIZE)); | |
1339 | ||
1340 | switch (mode) { | |
ce8e922c | 1341 | case XBRW_ZERO: |
1da177e4 LT |
1342 | memset(page_address(page) + cpoff, 0, csize); |
1343 | break; | |
ce8e922c | 1344 | case XBRW_READ: |
1da177e4 LT |
1345 | memcpy(data, page_address(page) + cpoff, csize); |
1346 | break; | |
ce8e922c | 1347 | case XBRW_WRITE: |
1da177e4 LT |
1348 | memcpy(page_address(page) + cpoff, data, csize); |
1349 | } | |
1350 | ||
1351 | boff += csize; | |
1352 | data += csize; | |
1353 | } | |
1354 | } | |
1355 | ||
1356 | /* | |
ce8e922c | 1357 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1358 | */ |
1359 | ||
1360 | /* | |
ce8e922c NS |
1361 | * Wait for any bufs with callbacks that have been submitted but |
1362 | * have not yet returned... walk the hash list for the target. | |
1da177e4 LT |
1363 | */ |
1364 | void | |
1365 | xfs_wait_buftarg( | |
1366 | xfs_buftarg_t *btp) | |
1367 | { | |
1368 | xfs_buf_t *bp, *n; | |
1369 | xfs_bufhash_t *hash; | |
1370 | uint i; | |
1371 | ||
1372 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { | |
1373 | hash = &btp->bt_hash[i]; | |
1374 | again: | |
1375 | spin_lock(&hash->bh_lock); | |
ce8e922c NS |
1376 | list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) { |
1377 | ASSERT(btp == bp->b_target); | |
1378 | if (!(bp->b_flags & XBF_FS_MANAGED)) { | |
1da177e4 | 1379 | spin_unlock(&hash->bh_lock); |
2f926587 DC |
1380 | /* |
1381 | * Catch superblock reference count leaks | |
1382 | * immediately | |
1383 | */ | |
ce8e922c | 1384 | BUG_ON(bp->b_bn == 0); |
1da177e4 LT |
1385 | delay(100); |
1386 | goto again; | |
1387 | } | |
1388 | } | |
1389 | spin_unlock(&hash->bh_lock); | |
1390 | } | |
1391 | } | |
1392 | ||
1393 | /* | |
ce8e922c NS |
1394 | * Allocate buffer hash table for a given target. |
1395 | * For devices containing metadata (i.e. not the log/realtime devices) | |
1396 | * we need to allocate a much larger hash table. | |
1da177e4 LT |
1397 | */ |
1398 | STATIC void | |
1399 | xfs_alloc_bufhash( | |
1400 | xfs_buftarg_t *btp, | |
1401 | int external) | |
1402 | { | |
1403 | unsigned int i; | |
1404 | ||
1405 | btp->bt_hashshift = external ? 3 : 8; /* 8 or 256 buckets */ | |
1406 | btp->bt_hashmask = (1 << btp->bt_hashshift) - 1; | |
1407 | btp->bt_hash = kmem_zalloc((1 << btp->bt_hashshift) * | |
1408 | sizeof(xfs_bufhash_t), KM_SLEEP); | |
1409 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { | |
1410 | spin_lock_init(&btp->bt_hash[i].bh_lock); | |
1411 | INIT_LIST_HEAD(&btp->bt_hash[i].bh_list); | |
1412 | } | |
1413 | } | |
1414 | ||
1415 | STATIC void | |
1416 | xfs_free_bufhash( | |
1417 | xfs_buftarg_t *btp) | |
1418 | { | |
ce8e922c | 1419 | kmem_free(btp->bt_hash, (1<<btp->bt_hashshift) * sizeof(xfs_bufhash_t)); |
1da177e4 LT |
1420 | btp->bt_hash = NULL; |
1421 | } | |
1422 | ||
a6867a68 | 1423 | /* |
ce8e922c | 1424 | * buftarg list for delwrite queue processing |
a6867a68 DC |
1425 | */ |
1426 | STATIC LIST_HEAD(xfs_buftarg_list); | |
1427 | STATIC DEFINE_SPINLOCK(xfs_buftarg_lock); | |
1428 | ||
1429 | STATIC void | |
1430 | xfs_register_buftarg( | |
1431 | xfs_buftarg_t *btp) | |
1432 | { | |
1433 | spin_lock(&xfs_buftarg_lock); | |
1434 | list_add(&btp->bt_list, &xfs_buftarg_list); | |
1435 | spin_unlock(&xfs_buftarg_lock); | |
1436 | } | |
1437 | ||
1438 | STATIC void | |
1439 | xfs_unregister_buftarg( | |
1440 | xfs_buftarg_t *btp) | |
1441 | { | |
1442 | spin_lock(&xfs_buftarg_lock); | |
1443 | list_del(&btp->bt_list); | |
1444 | spin_unlock(&xfs_buftarg_lock); | |
1445 | } | |
1446 | ||
1da177e4 LT |
1447 | void |
1448 | xfs_free_buftarg( | |
1449 | xfs_buftarg_t *btp, | |
1450 | int external) | |
1451 | { | |
1452 | xfs_flush_buftarg(btp, 1); | |
1453 | if (external) | |
ce8e922c | 1454 | xfs_blkdev_put(btp->bt_bdev); |
1da177e4 | 1455 | xfs_free_bufhash(btp); |
ce8e922c | 1456 | iput(btp->bt_mapping->host); |
a6867a68 | 1457 | |
ce8e922c NS |
1458 | /* Unregister the buftarg first so that we don't get a |
1459 | * wakeup finding a non-existent task | |
1460 | */ | |
a6867a68 DC |
1461 | xfs_unregister_buftarg(btp); |
1462 | kthread_stop(btp->bt_task); | |
1463 | ||
1da177e4 LT |
1464 | kmem_free(btp, sizeof(*btp)); |
1465 | } | |
1466 | ||
1da177e4 LT |
1467 | STATIC int |
1468 | xfs_setsize_buftarg_flags( | |
1469 | xfs_buftarg_t *btp, | |
1470 | unsigned int blocksize, | |
1471 | unsigned int sectorsize, | |
1472 | int verbose) | |
1473 | { | |
ce8e922c NS |
1474 | btp->bt_bsize = blocksize; |
1475 | btp->bt_sshift = ffs(sectorsize) - 1; | |
1476 | btp->bt_smask = sectorsize - 1; | |
1da177e4 | 1477 | |
ce8e922c | 1478 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
1da177e4 LT |
1479 | printk(KERN_WARNING |
1480 | "XFS: Cannot set_blocksize to %u on device %s\n", | |
1481 | sectorsize, XFS_BUFTARG_NAME(btp)); | |
1482 | return EINVAL; | |
1483 | } | |
1484 | ||
1485 | if (verbose && | |
1486 | (PAGE_CACHE_SIZE / BITS_PER_LONG) > sectorsize) { | |
1487 | printk(KERN_WARNING | |
1488 | "XFS: %u byte sectors in use on device %s. " | |
1489 | "This is suboptimal; %u or greater is ideal.\n", | |
1490 | sectorsize, XFS_BUFTARG_NAME(btp), | |
1491 | (unsigned int)PAGE_CACHE_SIZE / BITS_PER_LONG); | |
1492 | } | |
1493 | ||
1494 | return 0; | |
1495 | } | |
1496 | ||
1497 | /* | |
ce8e922c NS |
1498 | * When allocating the initial buffer target we have not yet |
1499 | * read in the superblock, so don't know what sized sectors | |
1500 | * are being used is at this early stage. Play safe. | |
1501 | */ | |
1da177e4 LT |
1502 | STATIC int |
1503 | xfs_setsize_buftarg_early( | |
1504 | xfs_buftarg_t *btp, | |
1505 | struct block_device *bdev) | |
1506 | { | |
1507 | return xfs_setsize_buftarg_flags(btp, | |
1508 | PAGE_CACHE_SIZE, bdev_hardsect_size(bdev), 0); | |
1509 | } | |
1510 | ||
1511 | int | |
1512 | xfs_setsize_buftarg( | |
1513 | xfs_buftarg_t *btp, | |
1514 | unsigned int blocksize, | |
1515 | unsigned int sectorsize) | |
1516 | { | |
1517 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | |
1518 | } | |
1519 | ||
1520 | STATIC int | |
1521 | xfs_mapping_buftarg( | |
1522 | xfs_buftarg_t *btp, | |
1523 | struct block_device *bdev) | |
1524 | { | |
1525 | struct backing_dev_info *bdi; | |
1526 | struct inode *inode; | |
1527 | struct address_space *mapping; | |
f5e54d6e | 1528 | static const struct address_space_operations mapping_aops = { |
1da177e4 | 1529 | .sync_page = block_sync_page, |
e965f963 | 1530 | .migratepage = fail_migrate_page, |
1da177e4 LT |
1531 | }; |
1532 | ||
1533 | inode = new_inode(bdev->bd_inode->i_sb); | |
1534 | if (!inode) { | |
1535 | printk(KERN_WARNING | |
1536 | "XFS: Cannot allocate mapping inode for device %s\n", | |
1537 | XFS_BUFTARG_NAME(btp)); | |
1538 | return ENOMEM; | |
1539 | } | |
1540 | inode->i_mode = S_IFBLK; | |
1541 | inode->i_bdev = bdev; | |
1542 | inode->i_rdev = bdev->bd_dev; | |
1543 | bdi = blk_get_backing_dev_info(bdev); | |
1544 | if (!bdi) | |
1545 | bdi = &default_backing_dev_info; | |
1546 | mapping = &inode->i_data; | |
1547 | mapping->a_ops = &mapping_aops; | |
1548 | mapping->backing_dev_info = bdi; | |
1549 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
ce8e922c | 1550 | btp->bt_mapping = mapping; |
1da177e4 LT |
1551 | return 0; |
1552 | } | |
1553 | ||
a6867a68 DC |
1554 | STATIC int |
1555 | xfs_alloc_delwrite_queue( | |
1556 | xfs_buftarg_t *btp) | |
1557 | { | |
1558 | int error = 0; | |
1559 | ||
1560 | INIT_LIST_HEAD(&btp->bt_list); | |
1561 | INIT_LIST_HEAD(&btp->bt_delwrite_queue); | |
1562 | spinlock_init(&btp->bt_delwrite_lock, "delwri_lock"); | |
1563 | btp->bt_flags = 0; | |
1564 | btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd"); | |
1565 | if (IS_ERR(btp->bt_task)) { | |
1566 | error = PTR_ERR(btp->bt_task); | |
1567 | goto out_error; | |
1568 | } | |
1569 | xfs_register_buftarg(btp); | |
1570 | out_error: | |
1571 | return error; | |
1572 | } | |
1573 | ||
1da177e4 LT |
1574 | xfs_buftarg_t * |
1575 | xfs_alloc_buftarg( | |
1576 | struct block_device *bdev, | |
1577 | int external) | |
1578 | { | |
1579 | xfs_buftarg_t *btp; | |
1580 | ||
1581 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP); | |
1582 | ||
ce8e922c NS |
1583 | btp->bt_dev = bdev->bd_dev; |
1584 | btp->bt_bdev = bdev; | |
1da177e4 LT |
1585 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1586 | goto error; | |
1587 | if (xfs_mapping_buftarg(btp, bdev)) | |
1588 | goto error; | |
a6867a68 DC |
1589 | if (xfs_alloc_delwrite_queue(btp)) |
1590 | goto error; | |
1da177e4 LT |
1591 | xfs_alloc_bufhash(btp, external); |
1592 | return btp; | |
1593 | ||
1594 | error: | |
1595 | kmem_free(btp, sizeof(*btp)); | |
1596 | return NULL; | |
1597 | } | |
1598 | ||
1599 | ||
1600 | /* | |
ce8e922c | 1601 | * Delayed write buffer handling |
1da177e4 | 1602 | */ |
1da177e4 | 1603 | STATIC void |
ce8e922c NS |
1604 | xfs_buf_delwri_queue( |
1605 | xfs_buf_t *bp, | |
1da177e4 LT |
1606 | int unlock) |
1607 | { | |
ce8e922c NS |
1608 | struct list_head *dwq = &bp->b_target->bt_delwrite_queue; |
1609 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; | |
a6867a68 | 1610 | |
ce8e922c NS |
1611 | XB_TRACE(bp, "delwri_q", (long)unlock); |
1612 | ASSERT((bp->b_flags&(XBF_DELWRI|XBF_ASYNC)) == (XBF_DELWRI|XBF_ASYNC)); | |
1da177e4 | 1613 | |
a6867a68 | 1614 | spin_lock(dwlk); |
1da177e4 | 1615 | /* If already in the queue, dequeue and place at tail */ |
ce8e922c NS |
1616 | if (!list_empty(&bp->b_list)) { |
1617 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1618 | if (unlock) | |
1619 | atomic_dec(&bp->b_hold); | |
1620 | list_del(&bp->b_list); | |
1da177e4 LT |
1621 | } |
1622 | ||
ce8e922c NS |
1623 | bp->b_flags |= _XBF_DELWRI_Q; |
1624 | list_add_tail(&bp->b_list, dwq); | |
1625 | bp->b_queuetime = jiffies; | |
a6867a68 | 1626 | spin_unlock(dwlk); |
1da177e4 LT |
1627 | |
1628 | if (unlock) | |
ce8e922c | 1629 | xfs_buf_unlock(bp); |
1da177e4 LT |
1630 | } |
1631 | ||
1632 | void | |
ce8e922c NS |
1633 | xfs_buf_delwri_dequeue( |
1634 | xfs_buf_t *bp) | |
1da177e4 | 1635 | { |
ce8e922c | 1636 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; |
1da177e4 LT |
1637 | int dequeued = 0; |
1638 | ||
a6867a68 | 1639 | spin_lock(dwlk); |
ce8e922c NS |
1640 | if ((bp->b_flags & XBF_DELWRI) && !list_empty(&bp->b_list)) { |
1641 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1642 | list_del_init(&bp->b_list); | |
1da177e4 LT |
1643 | dequeued = 1; |
1644 | } | |
ce8e922c | 1645 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); |
a6867a68 | 1646 | spin_unlock(dwlk); |
1da177e4 LT |
1647 | |
1648 | if (dequeued) | |
ce8e922c | 1649 | xfs_buf_rele(bp); |
1da177e4 | 1650 | |
ce8e922c | 1651 | XB_TRACE(bp, "delwri_dq", (long)dequeued); |
1da177e4 LT |
1652 | } |
1653 | ||
1654 | STATIC void | |
ce8e922c | 1655 | xfs_buf_runall_queues( |
1da177e4 LT |
1656 | struct workqueue_struct *queue) |
1657 | { | |
1658 | flush_workqueue(queue); | |
1659 | } | |
1660 | ||
1da177e4 | 1661 | STATIC int |
23ea4032 | 1662 | xfsbufd_wakeup( |
15c84a47 NS |
1663 | int priority, |
1664 | gfp_t mask) | |
1da177e4 | 1665 | { |
da7f93e9 | 1666 | xfs_buftarg_t *btp; |
a6867a68 DC |
1667 | |
1668 | spin_lock(&xfs_buftarg_lock); | |
da7f93e9 | 1669 | list_for_each_entry(btp, &xfs_buftarg_list, bt_list) { |
ce8e922c | 1670 | if (test_bit(XBT_FORCE_SLEEP, &btp->bt_flags)) |
a6867a68 | 1671 | continue; |
ce8e922c | 1672 | set_bit(XBT_FORCE_FLUSH, &btp->bt_flags); |
a6867a68 DC |
1673 | wake_up_process(btp->bt_task); |
1674 | } | |
1675 | spin_unlock(&xfs_buftarg_lock); | |
1da177e4 LT |
1676 | return 0; |
1677 | } | |
1678 | ||
1679 | STATIC int | |
23ea4032 | 1680 | xfsbufd( |
1da177e4 LT |
1681 | void *data) |
1682 | { | |
1683 | struct list_head tmp; | |
1684 | unsigned long age; | |
a6867a68 | 1685 | xfs_buftarg_t *target = (xfs_buftarg_t *)data; |
ce8e922c | 1686 | xfs_buf_t *bp, *n; |
a6867a68 DC |
1687 | struct list_head *dwq = &target->bt_delwrite_queue; |
1688 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
f07c2250 | 1689 | int count; |
1da177e4 | 1690 | |
1da177e4 LT |
1691 | current->flags |= PF_MEMALLOC; |
1692 | ||
1da177e4 LT |
1693 | INIT_LIST_HEAD(&tmp); |
1694 | do { | |
3e1d1d28 | 1695 | if (unlikely(freezing(current))) { |
ce8e922c | 1696 | set_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
3e1d1d28 | 1697 | refrigerator(); |
abd0cf7a | 1698 | } else { |
ce8e922c | 1699 | clear_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
abd0cf7a | 1700 | } |
1da177e4 | 1701 | |
15c84a47 NS |
1702 | schedule_timeout_interruptible( |
1703 | xfs_buf_timer_centisecs * msecs_to_jiffies(10)); | |
1da177e4 | 1704 | |
f07c2250 | 1705 | count = 0; |
041e0e3b | 1706 | age = xfs_buf_age_centisecs * msecs_to_jiffies(10); |
a6867a68 | 1707 | spin_lock(dwlk); |
ce8e922c NS |
1708 | list_for_each_entry_safe(bp, n, dwq, b_list) { |
1709 | XB_TRACE(bp, "walkq1", (long)xfs_buf_ispin(bp)); | |
1710 | ASSERT(bp->b_flags & XBF_DELWRI); | |
1da177e4 | 1711 | |
ce8e922c NS |
1712 | if (!xfs_buf_ispin(bp) && !xfs_buf_cond_lock(bp)) { |
1713 | if (!test_bit(XBT_FORCE_FLUSH, | |
a6867a68 | 1714 | &target->bt_flags) && |
1da177e4 | 1715 | time_before(jiffies, |
ce8e922c NS |
1716 | bp->b_queuetime + age)) { |
1717 | xfs_buf_unlock(bp); | |
1da177e4 LT |
1718 | break; |
1719 | } | |
1720 | ||
f07c2250 NS |
1721 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q| |
1722 | _XBF_RUN_QUEUES); | |
ce8e922c | 1723 | bp->b_flags |= XBF_WRITE; |
f07c2250 NS |
1724 | list_move_tail(&bp->b_list, &tmp); |
1725 | count++; | |
1da177e4 LT |
1726 | } |
1727 | } | |
a6867a68 | 1728 | spin_unlock(dwlk); |
1da177e4 LT |
1729 | |
1730 | while (!list_empty(&tmp)) { | |
ce8e922c NS |
1731 | bp = list_entry(tmp.next, xfs_buf_t, b_list); |
1732 | ASSERT(target == bp->b_target); | |
1da177e4 | 1733 | |
ce8e922c NS |
1734 | list_del_init(&bp->b_list); |
1735 | xfs_buf_iostrategy(bp); | |
1da177e4 LT |
1736 | } |
1737 | ||
1738 | if (as_list_len > 0) | |
1739 | purge_addresses(); | |
f07c2250 NS |
1740 | if (count) |
1741 | blk_run_address_space(target->bt_mapping); | |
1da177e4 | 1742 | |
ce8e922c | 1743 | clear_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
4df08c52 | 1744 | } while (!kthread_should_stop()); |
1da177e4 | 1745 | |
4df08c52 | 1746 | return 0; |
1da177e4 LT |
1747 | } |
1748 | ||
1749 | /* | |
ce8e922c NS |
1750 | * Go through all incore buffers, and release buffers if they belong to |
1751 | * the given device. This is used in filesystem error handling to | |
1752 | * preserve the consistency of its metadata. | |
1da177e4 LT |
1753 | */ |
1754 | int | |
1755 | xfs_flush_buftarg( | |
1756 | xfs_buftarg_t *target, | |
1757 | int wait) | |
1758 | { | |
1759 | struct list_head tmp; | |
ce8e922c | 1760 | xfs_buf_t *bp, *n; |
1da177e4 | 1761 | int pincount = 0; |
a6867a68 DC |
1762 | struct list_head *dwq = &target->bt_delwrite_queue; |
1763 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1da177e4 | 1764 | |
ce8e922c NS |
1765 | xfs_buf_runall_queues(xfsdatad_workqueue); |
1766 | xfs_buf_runall_queues(xfslogd_workqueue); | |
1da177e4 LT |
1767 | |
1768 | INIT_LIST_HEAD(&tmp); | |
a6867a68 | 1769 | spin_lock(dwlk); |
ce8e922c NS |
1770 | list_for_each_entry_safe(bp, n, dwq, b_list) { |
1771 | ASSERT(bp->b_target == target); | |
1772 | ASSERT(bp->b_flags & (XBF_DELWRI | _XBF_DELWRI_Q)); | |
1773 | XB_TRACE(bp, "walkq2", (long)xfs_buf_ispin(bp)); | |
1774 | if (xfs_buf_ispin(bp)) { | |
1da177e4 LT |
1775 | pincount++; |
1776 | continue; | |
1777 | } | |
1778 | ||
f07c2250 | 1779 | list_move_tail(&bp->b_list, &tmp); |
1da177e4 | 1780 | } |
a6867a68 | 1781 | spin_unlock(dwlk); |
1da177e4 LT |
1782 | |
1783 | /* | |
1784 | * Dropped the delayed write list lock, now walk the temporary list | |
1785 | */ | |
ce8e922c NS |
1786 | list_for_each_entry_safe(bp, n, &tmp, b_list) { |
1787 | xfs_buf_lock(bp); | |
f07c2250 | 1788 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q|_XBF_RUN_QUEUES); |
ce8e922c | 1789 | bp->b_flags |= XBF_WRITE; |
1da177e4 | 1790 | if (wait) |
ce8e922c | 1791 | bp->b_flags &= ~XBF_ASYNC; |
1da177e4 | 1792 | else |
ce8e922c | 1793 | list_del_init(&bp->b_list); |
1da177e4 | 1794 | |
ce8e922c | 1795 | xfs_buf_iostrategy(bp); |
1da177e4 LT |
1796 | } |
1797 | ||
f07c2250 NS |
1798 | if (wait) |
1799 | blk_run_address_space(target->bt_mapping); | |
1800 | ||
1da177e4 LT |
1801 | /* |
1802 | * Remaining list items must be flushed before returning | |
1803 | */ | |
1804 | while (!list_empty(&tmp)) { | |
ce8e922c | 1805 | bp = list_entry(tmp.next, xfs_buf_t, b_list); |
1da177e4 | 1806 | |
ce8e922c NS |
1807 | list_del_init(&bp->b_list); |
1808 | xfs_iowait(bp); | |
1809 | xfs_buf_relse(bp); | |
1da177e4 LT |
1810 | } |
1811 | ||
1da177e4 LT |
1812 | return pincount; |
1813 | } | |
1814 | ||
04d8b284 | 1815 | int __init |
ce8e922c | 1816 | xfs_buf_init(void) |
1da177e4 | 1817 | { |
ce8e922c NS |
1818 | #ifdef XFS_BUF_TRACE |
1819 | xfs_buf_trace_buf = ktrace_alloc(XFS_BUF_TRACE_SIZE, KM_SLEEP); | |
04d8b284 CH |
1820 | #endif |
1821 | ||
8758280f NS |
1822 | xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf", |
1823 | KM_ZONE_HWALIGN, NULL); | |
ce8e922c | 1824 | if (!xfs_buf_zone) |
04d8b284 CH |
1825 | goto out_free_trace_buf; |
1826 | ||
23ea4032 CH |
1827 | xfslogd_workqueue = create_workqueue("xfslogd"); |
1828 | if (!xfslogd_workqueue) | |
04d8b284 | 1829 | goto out_free_buf_zone; |
1da177e4 | 1830 | |
23ea4032 CH |
1831 | xfsdatad_workqueue = create_workqueue("xfsdatad"); |
1832 | if (!xfsdatad_workqueue) | |
1833 | goto out_destroy_xfslogd_workqueue; | |
1da177e4 | 1834 | |
ce8e922c NS |
1835 | xfs_buf_shake = kmem_shake_register(xfsbufd_wakeup); |
1836 | if (!xfs_buf_shake) | |
a6867a68 | 1837 | goto out_destroy_xfsdatad_workqueue; |
04d8b284 | 1838 | |
23ea4032 | 1839 | return 0; |
1da177e4 | 1840 | |
23ea4032 CH |
1841 | out_destroy_xfsdatad_workqueue: |
1842 | destroy_workqueue(xfsdatad_workqueue); | |
1843 | out_destroy_xfslogd_workqueue: | |
1844 | destroy_workqueue(xfslogd_workqueue); | |
23ea4032 | 1845 | out_free_buf_zone: |
ce8e922c | 1846 | kmem_zone_destroy(xfs_buf_zone); |
04d8b284 | 1847 | out_free_trace_buf: |
ce8e922c NS |
1848 | #ifdef XFS_BUF_TRACE |
1849 | ktrace_free(xfs_buf_trace_buf); | |
23ea4032 | 1850 | #endif |
8758280f | 1851 | return -ENOMEM; |
1da177e4 LT |
1852 | } |
1853 | ||
1da177e4 | 1854 | void |
ce8e922c | 1855 | xfs_buf_terminate(void) |
1da177e4 | 1856 | { |
ce8e922c | 1857 | kmem_shake_deregister(xfs_buf_shake); |
04d8b284 CH |
1858 | destroy_workqueue(xfsdatad_workqueue); |
1859 | destroy_workqueue(xfslogd_workqueue); | |
ce8e922c NS |
1860 | kmem_zone_destroy(xfs_buf_zone); |
1861 | #ifdef XFS_BUF_TRACE | |
1862 | ktrace_free(xfs_buf_trace_buf); | |
1da177e4 | 1863 | #endif |
1da177e4 | 1864 | } |