Commit | Line | Data |
---|---|---|
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> |
1da177e4 LT |
32 | #include "xfs_linux.h" |
33 | ||
ce8e922c NS |
34 | STATIC kmem_zone_t *xfs_buf_zone; |
35 | STATIC kmem_shaker_t xfs_buf_shake; | |
a6867a68 | 36 | STATIC int xfsbufd(void *); |
27496a8c | 37 | STATIC int xfsbufd_wakeup(int, gfp_t); |
ce8e922c | 38 | STATIC void xfs_buf_delwri_queue(xfs_buf_t *, int); |
23ea4032 CH |
39 | |
40 | STATIC struct workqueue_struct *xfslogd_workqueue; | |
0829c360 | 41 | struct workqueue_struct *xfsdatad_workqueue; |
1da177e4 | 42 | |
ce8e922c | 43 | #ifdef XFS_BUF_TRACE |
1da177e4 | 44 | void |
ce8e922c NS |
45 | xfs_buf_trace( |
46 | xfs_buf_t *bp, | |
1da177e4 LT |
47 | char *id, |
48 | void *data, | |
49 | void *ra) | |
50 | { | |
ce8e922c NS |
51 | ktrace_enter(xfs_buf_trace_buf, |
52 | bp, id, | |
53 | (void *)(unsigned long)bp->b_flags, | |
54 | (void *)(unsigned long)bp->b_hold.counter, | |
55 | (void *)(unsigned long)bp->b_sema.count.counter, | |
1da177e4 LT |
56 | (void *)current, |
57 | data, ra, | |
ce8e922c NS |
58 | (void *)(unsigned long)((bp->b_file_offset>>32) & 0xffffffff), |
59 | (void *)(unsigned long)(bp->b_file_offset & 0xffffffff), | |
60 | (void *)(unsigned long)bp->b_buffer_length, | |
1da177e4 LT |
61 | NULL, NULL, NULL, NULL, NULL); |
62 | } | |
ce8e922c NS |
63 | ktrace_t *xfs_buf_trace_buf; |
64 | #define XFS_BUF_TRACE_SIZE 4096 | |
65 | #define XB_TRACE(bp, id, data) \ | |
66 | xfs_buf_trace(bp, id, (void *)data, (void *)__builtin_return_address(0)) | |
1da177e4 | 67 | #else |
ce8e922c | 68 | #define XB_TRACE(bp, id, data) do { } while (0) |
1da177e4 LT |
69 | #endif |
70 | ||
ce8e922c NS |
71 | #ifdef XFS_BUF_LOCK_TRACKING |
72 | # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid) | |
73 | # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1) | |
74 | # define XB_GET_OWNER(bp) ((bp)->b_last_holder) | |
1da177e4 | 75 | #else |
ce8e922c NS |
76 | # define XB_SET_OWNER(bp) do { } while (0) |
77 | # define XB_CLEAR_OWNER(bp) do { } while (0) | |
78 | # define XB_GET_OWNER(bp) do { } while (0) | |
1da177e4 LT |
79 | #endif |
80 | ||
ce8e922c NS |
81 | #define xb_to_gfp(flags) \ |
82 | ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : \ | |
83 | ((flags) & XBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN) | |
1da177e4 | 84 | |
ce8e922c NS |
85 | #define xb_to_km(flags) \ |
86 | (((flags) & XBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP) | |
1da177e4 | 87 | |
ce8e922c NS |
88 | #define xfs_buf_allocate(flags) \ |
89 | kmem_zone_alloc(xfs_buf_zone, xb_to_km(flags)) | |
90 | #define xfs_buf_deallocate(bp) \ | |
91 | kmem_zone_free(xfs_buf_zone, (bp)); | |
1da177e4 LT |
92 | |
93 | /* | |
ce8e922c | 94 | * Page Region interfaces. |
1da177e4 | 95 | * |
ce8e922c NS |
96 | * For pages in filesystems where the blocksize is smaller than the |
97 | * pagesize, we use the page->private field (long) to hold a bitmap | |
98 | * of uptodate regions within the page. | |
1da177e4 | 99 | * |
ce8e922c | 100 | * Each such region is "bytes per page / bits per long" bytes long. |
1da177e4 | 101 | * |
ce8e922c NS |
102 | * NBPPR == number-of-bytes-per-page-region |
103 | * BTOPR == bytes-to-page-region (rounded up) | |
104 | * BTOPRT == bytes-to-page-region-truncated (rounded down) | |
1da177e4 LT |
105 | */ |
106 | #if (BITS_PER_LONG == 32) | |
107 | #define PRSHIFT (PAGE_CACHE_SHIFT - 5) /* (32 == 1<<5) */ | |
108 | #elif (BITS_PER_LONG == 64) | |
109 | #define PRSHIFT (PAGE_CACHE_SHIFT - 6) /* (64 == 1<<6) */ | |
110 | #else | |
111 | #error BITS_PER_LONG must be 32 or 64 | |
112 | #endif | |
113 | #define NBPPR (PAGE_CACHE_SIZE/BITS_PER_LONG) | |
114 | #define BTOPR(b) (((unsigned int)(b) + (NBPPR - 1)) >> PRSHIFT) | |
115 | #define BTOPRT(b) (((unsigned int)(b) >> PRSHIFT)) | |
116 | ||
117 | STATIC unsigned long | |
118 | page_region_mask( | |
119 | size_t offset, | |
120 | size_t length) | |
121 | { | |
122 | unsigned long mask; | |
123 | int first, final; | |
124 | ||
125 | first = BTOPR(offset); | |
126 | final = BTOPRT(offset + length - 1); | |
127 | first = min(first, final); | |
128 | ||
129 | mask = ~0UL; | |
130 | mask <<= BITS_PER_LONG - (final - first); | |
131 | mask >>= BITS_PER_LONG - (final); | |
132 | ||
133 | ASSERT(offset + length <= PAGE_CACHE_SIZE); | |
134 | ASSERT((final - first) < BITS_PER_LONG && (final - first) >= 0); | |
135 | ||
136 | return mask; | |
137 | } | |
138 | ||
139 | STATIC inline void | |
140 | set_page_region( | |
141 | struct page *page, | |
142 | size_t offset, | |
143 | size_t length) | |
144 | { | |
4c21e2f2 HD |
145 | set_page_private(page, |
146 | page_private(page) | page_region_mask(offset, length)); | |
147 | if (page_private(page) == ~0UL) | |
1da177e4 LT |
148 | SetPageUptodate(page); |
149 | } | |
150 | ||
151 | STATIC inline int | |
152 | test_page_region( | |
153 | struct page *page, | |
154 | size_t offset, | |
155 | size_t length) | |
156 | { | |
157 | unsigned long mask = page_region_mask(offset, length); | |
158 | ||
4c21e2f2 | 159 | return (mask && (page_private(page) & mask) == mask); |
1da177e4 LT |
160 | } |
161 | ||
162 | /* | |
ce8e922c | 163 | * Mapping of multi-page buffers into contiguous virtual space |
1da177e4 LT |
164 | */ |
165 | ||
166 | typedef struct a_list { | |
167 | void *vm_addr; | |
168 | struct a_list *next; | |
169 | } a_list_t; | |
170 | ||
171 | STATIC a_list_t *as_free_head; | |
172 | STATIC int as_list_len; | |
173 | STATIC DEFINE_SPINLOCK(as_lock); | |
174 | ||
175 | /* | |
ce8e922c | 176 | * Try to batch vunmaps because they are costly. |
1da177e4 LT |
177 | */ |
178 | STATIC void | |
179 | free_address( | |
180 | void *addr) | |
181 | { | |
182 | a_list_t *aentry; | |
183 | ||
184 | aentry = kmalloc(sizeof(a_list_t), GFP_ATOMIC & ~__GFP_HIGH); | |
185 | if (likely(aentry)) { | |
186 | spin_lock(&as_lock); | |
187 | aentry->next = as_free_head; | |
188 | aentry->vm_addr = addr; | |
189 | as_free_head = aentry; | |
190 | as_list_len++; | |
191 | spin_unlock(&as_lock); | |
192 | } else { | |
193 | vunmap(addr); | |
194 | } | |
195 | } | |
196 | ||
197 | STATIC void | |
198 | purge_addresses(void) | |
199 | { | |
200 | a_list_t *aentry, *old; | |
201 | ||
202 | if (as_free_head == NULL) | |
203 | return; | |
204 | ||
205 | spin_lock(&as_lock); | |
206 | aentry = as_free_head; | |
207 | as_free_head = NULL; | |
208 | as_list_len = 0; | |
209 | spin_unlock(&as_lock); | |
210 | ||
211 | while ((old = aentry) != NULL) { | |
212 | vunmap(aentry->vm_addr); | |
213 | aentry = aentry->next; | |
214 | kfree(old); | |
215 | } | |
216 | } | |
217 | ||
218 | /* | |
ce8e922c | 219 | * Internal xfs_buf_t object manipulation |
1da177e4 LT |
220 | */ |
221 | ||
222 | STATIC void | |
ce8e922c NS |
223 | _xfs_buf_initialize( |
224 | xfs_buf_t *bp, | |
1da177e4 | 225 | xfs_buftarg_t *target, |
204ab25f | 226 | xfs_off_t range_base, |
1da177e4 | 227 | size_t range_length, |
ce8e922c | 228 | xfs_buf_flags_t flags) |
1da177e4 LT |
229 | { |
230 | /* | |
ce8e922c | 231 | * We don't want certain flags to appear in b_flags. |
1da177e4 | 232 | */ |
ce8e922c NS |
233 | flags &= ~(XBF_LOCK|XBF_MAPPED|XBF_DONT_BLOCK|XBF_READ_AHEAD); |
234 | ||
235 | memset(bp, 0, sizeof(xfs_buf_t)); | |
236 | atomic_set(&bp->b_hold, 1); | |
237 | init_MUTEX_LOCKED(&bp->b_iodonesema); | |
238 | INIT_LIST_HEAD(&bp->b_list); | |
239 | INIT_LIST_HEAD(&bp->b_hash_list); | |
240 | init_MUTEX_LOCKED(&bp->b_sema); /* held, no waiters */ | |
241 | XB_SET_OWNER(bp); | |
242 | bp->b_target = target; | |
243 | bp->b_file_offset = range_base; | |
1da177e4 LT |
244 | /* |
245 | * Set buffer_length and count_desired to the same value initially. | |
246 | * I/O routines should use count_desired, which will be the same in | |
247 | * most cases but may be reset (e.g. XFS recovery). | |
248 | */ | |
ce8e922c NS |
249 | bp->b_buffer_length = bp->b_count_desired = range_length; |
250 | bp->b_flags = flags; | |
251 | bp->b_bn = XFS_BUF_DADDR_NULL; | |
252 | atomic_set(&bp->b_pin_count, 0); | |
253 | init_waitqueue_head(&bp->b_waiters); | |
254 | ||
255 | XFS_STATS_INC(xb_create); | |
256 | XB_TRACE(bp, "initialize", target); | |
1da177e4 LT |
257 | } |
258 | ||
259 | /* | |
ce8e922c NS |
260 | * Allocate a page array capable of holding a specified number |
261 | * of pages, and point the page buf at it. | |
1da177e4 LT |
262 | */ |
263 | STATIC int | |
ce8e922c NS |
264 | _xfs_buf_get_pages( |
265 | xfs_buf_t *bp, | |
1da177e4 | 266 | int page_count, |
ce8e922c | 267 | xfs_buf_flags_t flags) |
1da177e4 LT |
268 | { |
269 | /* Make sure that we have a page list */ | |
ce8e922c NS |
270 | if (bp->b_pages == NULL) { |
271 | bp->b_offset = xfs_buf_poff(bp->b_file_offset); | |
272 | bp->b_page_count = page_count; | |
273 | if (page_count <= XB_PAGES) { | |
274 | bp->b_pages = bp->b_page_array; | |
1da177e4 | 275 | } else { |
ce8e922c NS |
276 | bp->b_pages = kmem_alloc(sizeof(struct page *) * |
277 | page_count, xb_to_km(flags)); | |
278 | if (bp->b_pages == NULL) | |
1da177e4 LT |
279 | return -ENOMEM; |
280 | } | |
ce8e922c | 281 | memset(bp->b_pages, 0, sizeof(struct page *) * page_count); |
1da177e4 LT |
282 | } |
283 | return 0; | |
284 | } | |
285 | ||
286 | /* | |
ce8e922c | 287 | * Frees b_pages if it was allocated. |
1da177e4 LT |
288 | */ |
289 | STATIC void | |
ce8e922c | 290 | _xfs_buf_free_pages( |
1da177e4 LT |
291 | xfs_buf_t *bp) |
292 | { | |
ce8e922c NS |
293 | if (bp->b_pages != bp->b_page_array) { |
294 | kmem_free(bp->b_pages, | |
295 | bp->b_page_count * sizeof(struct page *)); | |
1da177e4 LT |
296 | } |
297 | } | |
298 | ||
299 | /* | |
300 | * Releases the specified buffer. | |
301 | * | |
302 | * The modification state of any associated pages is left unchanged. | |
ce8e922c | 303 | * The buffer most not be on any hash - use xfs_buf_rele instead for |
1da177e4 LT |
304 | * hashed and refcounted buffers |
305 | */ | |
306 | void | |
ce8e922c | 307 | xfs_buf_free( |
1da177e4 LT |
308 | xfs_buf_t *bp) |
309 | { | |
ce8e922c | 310 | XB_TRACE(bp, "free", 0); |
1da177e4 | 311 | |
ce8e922c | 312 | ASSERT(list_empty(&bp->b_hash_list)); |
1da177e4 | 313 | |
ce8e922c | 314 | if (bp->b_flags & _XBF_PAGE_CACHE) { |
1da177e4 LT |
315 | uint i; |
316 | ||
ce8e922c NS |
317 | if ((bp->b_flags & XBF_MAPPED) && (bp->b_page_count > 1)) |
318 | free_address(bp->b_addr - bp->b_offset); | |
1da177e4 | 319 | |
ce8e922c NS |
320 | for (i = 0; i < bp->b_page_count; i++) |
321 | page_cache_release(bp->b_pages[i]); | |
322 | _xfs_buf_free_pages(bp); | |
323 | } else if (bp->b_flags & _XBF_KMEM_ALLOC) { | |
1da177e4 | 324 | /* |
ce8e922c NS |
325 | * XXX(hch): bp->b_count_desired might be incorrect (see |
326 | * xfs_buf_associate_memory for details), but fortunately | |
1da177e4 LT |
327 | * the Linux version of kmem_free ignores the len argument.. |
328 | */ | |
ce8e922c NS |
329 | kmem_free(bp->b_addr, bp->b_count_desired); |
330 | _xfs_buf_free_pages(bp); | |
1da177e4 LT |
331 | } |
332 | ||
ce8e922c | 333 | xfs_buf_deallocate(bp); |
1da177e4 LT |
334 | } |
335 | ||
336 | /* | |
337 | * Finds all pages for buffer in question and builds it's page list. | |
338 | */ | |
339 | STATIC int | |
ce8e922c | 340 | _xfs_buf_lookup_pages( |
1da177e4 LT |
341 | xfs_buf_t *bp, |
342 | uint flags) | |
343 | { | |
ce8e922c NS |
344 | struct address_space *mapping = bp->b_target->bt_mapping; |
345 | size_t blocksize = bp->b_target->bt_bsize; | |
346 | size_t size = bp->b_count_desired; | |
1da177e4 | 347 | size_t nbytes, offset; |
ce8e922c | 348 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 LT |
349 | unsigned short page_count, i; |
350 | pgoff_t first; | |
204ab25f | 351 | xfs_off_t end; |
1da177e4 LT |
352 | int error; |
353 | ||
ce8e922c NS |
354 | end = bp->b_file_offset + bp->b_buffer_length; |
355 | page_count = xfs_buf_btoc(end) - xfs_buf_btoct(bp->b_file_offset); | |
1da177e4 | 356 | |
ce8e922c | 357 | error = _xfs_buf_get_pages(bp, page_count, flags); |
1da177e4 LT |
358 | if (unlikely(error)) |
359 | return error; | |
ce8e922c | 360 | bp->b_flags |= _XBF_PAGE_CACHE; |
1da177e4 | 361 | |
ce8e922c NS |
362 | offset = bp->b_offset; |
363 | first = bp->b_file_offset >> PAGE_CACHE_SHIFT; | |
1da177e4 | 364 | |
ce8e922c | 365 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
366 | struct page *page; |
367 | uint retries = 0; | |
368 | ||
369 | retry: | |
370 | page = find_or_create_page(mapping, first + i, gfp_mask); | |
371 | if (unlikely(page == NULL)) { | |
ce8e922c NS |
372 | if (flags & XBF_READ_AHEAD) { |
373 | bp->b_page_count = i; | |
374 | for (i = 0; i < bp->b_page_count; i++) | |
375 | unlock_page(bp->b_pages[i]); | |
1da177e4 LT |
376 | return -ENOMEM; |
377 | } | |
378 | ||
379 | /* | |
380 | * This could deadlock. | |
381 | * | |
382 | * But until all the XFS lowlevel code is revamped to | |
383 | * handle buffer allocation failures we can't do much. | |
384 | */ | |
385 | if (!(++retries % 100)) | |
386 | printk(KERN_ERR | |
387 | "XFS: possible memory allocation " | |
388 | "deadlock in %s (mode:0x%x)\n", | |
389 | __FUNCTION__, gfp_mask); | |
390 | ||
ce8e922c | 391 | XFS_STATS_INC(xb_page_retries); |
23ea4032 | 392 | xfsbufd_wakeup(0, gfp_mask); |
1da177e4 LT |
393 | blk_congestion_wait(WRITE, HZ/50); |
394 | goto retry; | |
395 | } | |
396 | ||
ce8e922c | 397 | XFS_STATS_INC(xb_page_found); |
1da177e4 LT |
398 | |
399 | nbytes = min_t(size_t, size, PAGE_CACHE_SIZE - offset); | |
400 | size -= nbytes; | |
401 | ||
402 | if (!PageUptodate(page)) { | |
403 | page_count--; | |
404 | if (blocksize >= PAGE_CACHE_SIZE) { | |
ce8e922c NS |
405 | if (flags & XBF_READ) |
406 | bp->b_locked = 1; | |
1da177e4 LT |
407 | } else if (!PagePrivate(page)) { |
408 | if (test_page_region(page, offset, nbytes)) | |
409 | page_count++; | |
410 | } | |
411 | } | |
412 | ||
ce8e922c | 413 | bp->b_pages[i] = page; |
1da177e4 LT |
414 | offset = 0; |
415 | } | |
416 | ||
ce8e922c NS |
417 | if (!bp->b_locked) { |
418 | for (i = 0; i < bp->b_page_count; i++) | |
419 | unlock_page(bp->b_pages[i]); | |
1da177e4 LT |
420 | } |
421 | ||
ce8e922c NS |
422 | if (page_count == bp->b_page_count) |
423 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 424 | |
ce8e922c | 425 | XB_TRACE(bp, "lookup_pages", (long)page_count); |
1da177e4 LT |
426 | return error; |
427 | } | |
428 | ||
429 | /* | |
430 | * Map buffer into kernel address-space if nessecary. | |
431 | */ | |
432 | STATIC int | |
ce8e922c | 433 | _xfs_buf_map_pages( |
1da177e4 LT |
434 | xfs_buf_t *bp, |
435 | uint flags) | |
436 | { | |
437 | /* A single page buffer is always mappable */ | |
ce8e922c NS |
438 | if (bp->b_page_count == 1) { |
439 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; | |
440 | bp->b_flags |= XBF_MAPPED; | |
441 | } else if (flags & XBF_MAPPED) { | |
1da177e4 LT |
442 | if (as_list_len > 64) |
443 | purge_addresses(); | |
ce8e922c NS |
444 | bp->b_addr = vmap(bp->b_pages, bp->b_page_count, |
445 | VM_MAP, PAGE_KERNEL); | |
446 | if (unlikely(bp->b_addr == NULL)) | |
1da177e4 | 447 | return -ENOMEM; |
ce8e922c NS |
448 | bp->b_addr += bp->b_offset; |
449 | bp->b_flags |= XBF_MAPPED; | |
1da177e4 LT |
450 | } |
451 | ||
452 | return 0; | |
453 | } | |
454 | ||
455 | /* | |
456 | * Finding and Reading Buffers | |
457 | */ | |
458 | ||
459 | /* | |
ce8e922c | 460 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 LT |
461 | * a given range of an inode. The buffer is returned |
462 | * locked. If other overlapping buffers exist, they are | |
463 | * released before the new buffer is created and locked, | |
464 | * which may imply that this call will block until those buffers | |
465 | * are unlocked. No I/O is implied by this call. | |
466 | */ | |
467 | xfs_buf_t * | |
ce8e922c | 468 | _xfs_buf_find( |
1da177e4 | 469 | xfs_buftarg_t *btp, /* block device target */ |
204ab25f | 470 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 471 | size_t isize, /* length of range */ |
ce8e922c NS |
472 | xfs_buf_flags_t flags, |
473 | xfs_buf_t *new_bp) | |
1da177e4 | 474 | { |
204ab25f | 475 | xfs_off_t range_base; |
1da177e4 LT |
476 | size_t range_length; |
477 | xfs_bufhash_t *hash; | |
ce8e922c | 478 | xfs_buf_t *bp, *n; |
1da177e4 LT |
479 | |
480 | range_base = (ioff << BBSHIFT); | |
481 | range_length = (isize << BBSHIFT); | |
482 | ||
483 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
ce8e922c | 484 | ASSERT(!(range_length < (1 << btp->bt_sshift))); |
204ab25f | 485 | ASSERT(!(range_base & (xfs_off_t)btp->bt_smask)); |
1da177e4 LT |
486 | |
487 | hash = &btp->bt_hash[hash_long((unsigned long)ioff, btp->bt_hashshift)]; | |
488 | ||
489 | spin_lock(&hash->bh_lock); | |
490 | ||
ce8e922c NS |
491 | list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) { |
492 | ASSERT(btp == bp->b_target); | |
493 | if (bp->b_file_offset == range_base && | |
494 | bp->b_buffer_length == range_length) { | |
1da177e4 | 495 | /* |
ce8e922c | 496 | * If we look at something, bring it to the |
1da177e4 LT |
497 | * front of the list for next time. |
498 | */ | |
ce8e922c NS |
499 | atomic_inc(&bp->b_hold); |
500 | list_move(&bp->b_hash_list, &hash->bh_list); | |
1da177e4 LT |
501 | goto found; |
502 | } | |
503 | } | |
504 | ||
505 | /* No match found */ | |
ce8e922c NS |
506 | if (new_bp) { |
507 | _xfs_buf_initialize(new_bp, btp, range_base, | |
1da177e4 | 508 | range_length, flags); |
ce8e922c NS |
509 | new_bp->b_hash = hash; |
510 | list_add(&new_bp->b_hash_list, &hash->bh_list); | |
1da177e4 | 511 | } else { |
ce8e922c | 512 | XFS_STATS_INC(xb_miss_locked); |
1da177e4 LT |
513 | } |
514 | ||
515 | spin_unlock(&hash->bh_lock); | |
ce8e922c | 516 | return new_bp; |
1da177e4 LT |
517 | |
518 | found: | |
519 | spin_unlock(&hash->bh_lock); | |
520 | ||
521 | /* Attempt to get the semaphore without sleeping, | |
522 | * if this does not work then we need to drop the | |
523 | * spinlock and do a hard attempt on the semaphore. | |
524 | */ | |
ce8e922c NS |
525 | if (down_trylock(&bp->b_sema)) { |
526 | if (!(flags & XBF_TRYLOCK)) { | |
1da177e4 | 527 | /* wait for buffer ownership */ |
ce8e922c NS |
528 | XB_TRACE(bp, "get_lock", 0); |
529 | xfs_buf_lock(bp); | |
530 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 LT |
531 | } else { |
532 | /* We asked for a trylock and failed, no need | |
533 | * to look at file offset and length here, we | |
ce8e922c NS |
534 | * know that this buffer at least overlaps our |
535 | * buffer and is locked, therefore our buffer | |
536 | * either does not exist, or is this buffer. | |
1da177e4 | 537 | */ |
ce8e922c NS |
538 | xfs_buf_rele(bp); |
539 | XFS_STATS_INC(xb_busy_locked); | |
540 | return NULL; | |
1da177e4 LT |
541 | } |
542 | } else { | |
543 | /* trylock worked */ | |
ce8e922c | 544 | XB_SET_OWNER(bp); |
1da177e4 LT |
545 | } |
546 | ||
ce8e922c NS |
547 | if (bp->b_flags & XBF_STALE) { |
548 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
549 | bp->b_flags &= XBF_MAPPED; | |
2f926587 | 550 | } |
ce8e922c NS |
551 | XB_TRACE(bp, "got_lock", 0); |
552 | XFS_STATS_INC(xb_get_locked); | |
553 | return bp; | |
1da177e4 LT |
554 | } |
555 | ||
556 | /* | |
ce8e922c | 557 | * Assembles a buffer covering the specified range. |
1da177e4 LT |
558 | * Storage in memory for all portions of the buffer will be allocated, |
559 | * although backing storage may not be. | |
560 | */ | |
561 | xfs_buf_t * | |
ce8e922c | 562 | xfs_buf_get_flags( |
1da177e4 | 563 | xfs_buftarg_t *target,/* target for buffer */ |
204ab25f | 564 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 565 | size_t isize, /* length of range */ |
ce8e922c | 566 | xfs_buf_flags_t flags) |
1da177e4 | 567 | { |
ce8e922c | 568 | xfs_buf_t *bp, *new_bp; |
1da177e4 LT |
569 | int error = 0, i; |
570 | ||
ce8e922c NS |
571 | new_bp = xfs_buf_allocate(flags); |
572 | if (unlikely(!new_bp)) | |
1da177e4 LT |
573 | return NULL; |
574 | ||
ce8e922c NS |
575 | bp = _xfs_buf_find(target, ioff, isize, flags, new_bp); |
576 | if (bp == new_bp) { | |
577 | error = _xfs_buf_lookup_pages(bp, flags); | |
1da177e4 LT |
578 | if (error) |
579 | goto no_buffer; | |
580 | } else { | |
ce8e922c NS |
581 | xfs_buf_deallocate(new_bp); |
582 | if (unlikely(bp == NULL)) | |
1da177e4 LT |
583 | return NULL; |
584 | } | |
585 | ||
ce8e922c NS |
586 | for (i = 0; i < bp->b_page_count; i++) |
587 | mark_page_accessed(bp->b_pages[i]); | |
1da177e4 | 588 | |
ce8e922c NS |
589 | if (!(bp->b_flags & XBF_MAPPED)) { |
590 | error = _xfs_buf_map_pages(bp, flags); | |
1da177e4 LT |
591 | if (unlikely(error)) { |
592 | printk(KERN_WARNING "%s: failed to map pages\n", | |
593 | __FUNCTION__); | |
594 | goto no_buffer; | |
595 | } | |
596 | } | |
597 | ||
ce8e922c | 598 | XFS_STATS_INC(xb_get); |
1da177e4 LT |
599 | |
600 | /* | |
601 | * Always fill in the block number now, the mapped cases can do | |
602 | * their own overlay of this later. | |
603 | */ | |
ce8e922c NS |
604 | bp->b_bn = ioff; |
605 | bp->b_count_desired = bp->b_buffer_length; | |
1da177e4 | 606 | |
ce8e922c NS |
607 | XB_TRACE(bp, "get", (unsigned long)flags); |
608 | return bp; | |
1da177e4 LT |
609 | |
610 | no_buffer: | |
ce8e922c NS |
611 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
612 | xfs_buf_unlock(bp); | |
613 | xfs_buf_rele(bp); | |
1da177e4 LT |
614 | return NULL; |
615 | } | |
616 | ||
617 | xfs_buf_t * | |
618 | xfs_buf_read_flags( | |
619 | xfs_buftarg_t *target, | |
204ab25f | 620 | xfs_off_t ioff, |
1da177e4 | 621 | size_t isize, |
ce8e922c | 622 | xfs_buf_flags_t flags) |
1da177e4 | 623 | { |
ce8e922c NS |
624 | xfs_buf_t *bp; |
625 | ||
626 | flags |= XBF_READ; | |
627 | ||
628 | bp = xfs_buf_get_flags(target, ioff, isize, flags); | |
629 | if (bp) { | |
630 | if (!XFS_BUF_ISDONE(bp)) { | |
631 | XB_TRACE(bp, "read", (unsigned long)flags); | |
632 | XFS_STATS_INC(xb_get_read); | |
633 | xfs_buf_iostart(bp, flags); | |
634 | } else if (flags & XBF_ASYNC) { | |
635 | XB_TRACE(bp, "read_async", (unsigned long)flags); | |
1da177e4 LT |
636 | /* |
637 | * Read ahead call which is already satisfied, | |
638 | * drop the buffer | |
639 | */ | |
640 | goto no_buffer; | |
641 | } else { | |
ce8e922c | 642 | XB_TRACE(bp, "read_done", (unsigned long)flags); |
1da177e4 | 643 | /* We do not want read in the flags */ |
ce8e922c | 644 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
645 | } |
646 | } | |
647 | ||
ce8e922c | 648 | return bp; |
1da177e4 LT |
649 | |
650 | no_buffer: | |
ce8e922c NS |
651 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
652 | xfs_buf_unlock(bp); | |
653 | xfs_buf_rele(bp); | |
1da177e4 LT |
654 | return NULL; |
655 | } | |
656 | ||
1da177e4 | 657 | /* |
ce8e922c NS |
658 | * If we are not low on memory then do the readahead in a deadlock |
659 | * safe manner. | |
1da177e4 LT |
660 | */ |
661 | void | |
ce8e922c | 662 | xfs_buf_readahead( |
1da177e4 | 663 | xfs_buftarg_t *target, |
204ab25f | 664 | xfs_off_t ioff, |
1da177e4 | 665 | size_t isize, |
ce8e922c | 666 | xfs_buf_flags_t flags) |
1da177e4 LT |
667 | { |
668 | struct backing_dev_info *bdi; | |
669 | ||
ce8e922c | 670 | bdi = target->bt_mapping->backing_dev_info; |
1da177e4 LT |
671 | if (bdi_read_congested(bdi)) |
672 | return; | |
673 | ||
ce8e922c | 674 | flags |= (XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD); |
1da177e4 LT |
675 | xfs_buf_read_flags(target, ioff, isize, flags); |
676 | } | |
677 | ||
678 | xfs_buf_t * | |
ce8e922c | 679 | xfs_buf_get_empty( |
1da177e4 LT |
680 | size_t len, |
681 | xfs_buftarg_t *target) | |
682 | { | |
ce8e922c | 683 | xfs_buf_t *bp; |
1da177e4 | 684 | |
ce8e922c NS |
685 | bp = xfs_buf_allocate(0); |
686 | if (bp) | |
687 | _xfs_buf_initialize(bp, target, 0, len, 0); | |
688 | return bp; | |
1da177e4 LT |
689 | } |
690 | ||
691 | static inline struct page * | |
692 | mem_to_page( | |
693 | void *addr) | |
694 | { | |
695 | if (((unsigned long)addr < VMALLOC_START) || | |
696 | ((unsigned long)addr >= VMALLOC_END)) { | |
697 | return virt_to_page(addr); | |
698 | } else { | |
699 | return vmalloc_to_page(addr); | |
700 | } | |
701 | } | |
702 | ||
703 | int | |
ce8e922c NS |
704 | xfs_buf_associate_memory( |
705 | xfs_buf_t *bp, | |
1da177e4 LT |
706 | void *mem, |
707 | size_t len) | |
708 | { | |
709 | int rval; | |
710 | int i = 0; | |
711 | size_t ptr; | |
712 | size_t end, end_cur; | |
713 | off_t offset; | |
714 | int page_count; | |
715 | ||
716 | page_count = PAGE_CACHE_ALIGN(len) >> PAGE_CACHE_SHIFT; | |
717 | offset = (off_t) mem - ((off_t)mem & PAGE_CACHE_MASK); | |
718 | if (offset && (len > PAGE_CACHE_SIZE)) | |
719 | page_count++; | |
720 | ||
721 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
722 | if (bp->b_pages) |
723 | _xfs_buf_free_pages(bp); | |
1da177e4 | 724 | |
ce8e922c NS |
725 | bp->b_pages = NULL; |
726 | bp->b_addr = mem; | |
1da177e4 | 727 | |
ce8e922c | 728 | rval = _xfs_buf_get_pages(bp, page_count, 0); |
1da177e4 LT |
729 | if (rval) |
730 | return rval; | |
731 | ||
ce8e922c | 732 | bp->b_offset = offset; |
1da177e4 LT |
733 | ptr = (size_t) mem & PAGE_CACHE_MASK; |
734 | end = PAGE_CACHE_ALIGN((size_t) mem + len); | |
735 | end_cur = end; | |
736 | /* set up first page */ | |
ce8e922c | 737 | bp->b_pages[0] = mem_to_page(mem); |
1da177e4 LT |
738 | |
739 | ptr += PAGE_CACHE_SIZE; | |
ce8e922c | 740 | bp->b_page_count = ++i; |
1da177e4 | 741 | while (ptr < end) { |
ce8e922c NS |
742 | bp->b_pages[i] = mem_to_page((void *)ptr); |
743 | bp->b_page_count = ++i; | |
1da177e4 LT |
744 | ptr += PAGE_CACHE_SIZE; |
745 | } | |
ce8e922c | 746 | bp->b_locked = 0; |
1da177e4 | 747 | |
ce8e922c NS |
748 | bp->b_count_desired = bp->b_buffer_length = len; |
749 | bp->b_flags |= XBF_MAPPED; | |
1da177e4 LT |
750 | |
751 | return 0; | |
752 | } | |
753 | ||
754 | xfs_buf_t * | |
ce8e922c | 755 | xfs_buf_get_noaddr( |
1da177e4 LT |
756 | size_t len, |
757 | xfs_buftarg_t *target) | |
758 | { | |
759 | size_t malloc_len = len; | |
760 | xfs_buf_t *bp; | |
761 | void *data; | |
762 | int error; | |
763 | ||
ce8e922c | 764 | bp = xfs_buf_allocate(0); |
1da177e4 LT |
765 | if (unlikely(bp == NULL)) |
766 | goto fail; | |
ce8e922c | 767 | _xfs_buf_initialize(bp, target, 0, len, 0); |
1da177e4 LT |
768 | |
769 | try_again: | |
770 | data = kmem_alloc(malloc_len, KM_SLEEP | KM_MAYFAIL); | |
771 | if (unlikely(data == NULL)) | |
772 | goto fail_free_buf; | |
773 | ||
774 | /* check whether alignment matches.. */ | |
775 | if ((__psunsigned_t)data != | |
ce8e922c | 776 | ((__psunsigned_t)data & ~target->bt_smask)) { |
1da177e4 LT |
777 | /* .. else double the size and try again */ |
778 | kmem_free(data, malloc_len); | |
779 | malloc_len <<= 1; | |
780 | goto try_again; | |
781 | } | |
782 | ||
ce8e922c | 783 | error = xfs_buf_associate_memory(bp, data, len); |
1da177e4 LT |
784 | if (error) |
785 | goto fail_free_mem; | |
ce8e922c | 786 | bp->b_flags |= _XBF_KMEM_ALLOC; |
1da177e4 | 787 | |
ce8e922c | 788 | xfs_buf_unlock(bp); |
1da177e4 | 789 | |
ce8e922c | 790 | XB_TRACE(bp, "no_daddr", data); |
1da177e4 LT |
791 | return bp; |
792 | fail_free_mem: | |
793 | kmem_free(data, malloc_len); | |
794 | fail_free_buf: | |
ce8e922c | 795 | xfs_buf_free(bp); |
1da177e4 LT |
796 | fail: |
797 | return NULL; | |
798 | } | |
799 | ||
800 | /* | |
1da177e4 LT |
801 | * Increment reference count on buffer, to hold the buffer concurrently |
802 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
803 | * Must hold the buffer already to call this function. |
804 | */ | |
805 | void | |
ce8e922c NS |
806 | xfs_buf_hold( |
807 | xfs_buf_t *bp) | |
1da177e4 | 808 | { |
ce8e922c NS |
809 | atomic_inc(&bp->b_hold); |
810 | XB_TRACE(bp, "hold", 0); | |
1da177e4 LT |
811 | } |
812 | ||
813 | /* | |
ce8e922c NS |
814 | * Releases a hold on the specified buffer. If the |
815 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
816 | */ |
817 | void | |
ce8e922c NS |
818 | xfs_buf_rele( |
819 | xfs_buf_t *bp) | |
1da177e4 | 820 | { |
ce8e922c | 821 | xfs_bufhash_t *hash = bp->b_hash; |
1da177e4 | 822 | |
ce8e922c | 823 | XB_TRACE(bp, "rele", bp->b_relse); |
1da177e4 | 824 | |
fad3aa1e NS |
825 | if (unlikely(!hash)) { |
826 | ASSERT(!bp->b_relse); | |
827 | if (atomic_dec_and_test(&bp->b_hold)) | |
828 | xfs_buf_free(bp); | |
829 | return; | |
830 | } | |
831 | ||
ce8e922c NS |
832 | if (atomic_dec_and_lock(&bp->b_hold, &hash->bh_lock)) { |
833 | if (bp->b_relse) { | |
834 | atomic_inc(&bp->b_hold); | |
1da177e4 | 835 | spin_unlock(&hash->bh_lock); |
ce8e922c NS |
836 | (*(bp->b_relse)) (bp); |
837 | } else if (bp->b_flags & XBF_FS_MANAGED) { | |
1da177e4 | 838 | spin_unlock(&hash->bh_lock); |
1da177e4 | 839 | } else { |
ce8e922c NS |
840 | ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q))); |
841 | list_del_init(&bp->b_hash_list); | |
1da177e4 | 842 | spin_unlock(&hash->bh_lock); |
ce8e922c | 843 | xfs_buf_free(bp); |
1da177e4 | 844 | } |
2f926587 DC |
845 | } else { |
846 | /* | |
847 | * Catch reference count leaks | |
848 | */ | |
ce8e922c | 849 | ASSERT(atomic_read(&bp->b_hold) >= 0); |
1da177e4 LT |
850 | } |
851 | } | |
852 | ||
853 | ||
854 | /* | |
855 | * Mutual exclusion on buffers. Locking model: | |
856 | * | |
857 | * Buffers associated with inodes for which buffer locking | |
858 | * is not enabled are not protected by semaphores, and are | |
859 | * assumed to be exclusively owned by the caller. There is a | |
860 | * spinlock in the buffer, used by the caller when concurrent | |
861 | * access is possible. | |
862 | */ | |
863 | ||
864 | /* | |
ce8e922c NS |
865 | * Locks a buffer object, if it is not already locked. |
866 | * Note that this in no way locks the underlying pages, so it is only | |
867 | * useful for synchronizing concurrent use of buffer objects, not for | |
868 | * synchronizing independent access to the underlying pages. | |
1da177e4 LT |
869 | */ |
870 | int | |
ce8e922c NS |
871 | xfs_buf_cond_lock( |
872 | xfs_buf_t *bp) | |
1da177e4 LT |
873 | { |
874 | int locked; | |
875 | ||
ce8e922c | 876 | locked = down_trylock(&bp->b_sema) == 0; |
1da177e4 | 877 | if (locked) { |
ce8e922c | 878 | XB_SET_OWNER(bp); |
1da177e4 | 879 | } |
ce8e922c NS |
880 | XB_TRACE(bp, "cond_lock", (long)locked); |
881 | return locked ? 0 : -EBUSY; | |
1da177e4 LT |
882 | } |
883 | ||
884 | #if defined(DEBUG) || defined(XFS_BLI_TRACE) | |
1da177e4 | 885 | int |
ce8e922c NS |
886 | xfs_buf_lock_value( |
887 | xfs_buf_t *bp) | |
1da177e4 | 888 | { |
ce8e922c | 889 | return atomic_read(&bp->b_sema.count); |
1da177e4 LT |
890 | } |
891 | #endif | |
892 | ||
893 | /* | |
ce8e922c NS |
894 | * Locks a buffer object. |
895 | * Note that this in no way locks the underlying pages, so it is only | |
896 | * useful for synchronizing concurrent use of buffer objects, not for | |
897 | * synchronizing independent access to the underlying pages. | |
1da177e4 | 898 | */ |
ce8e922c NS |
899 | void |
900 | xfs_buf_lock( | |
901 | xfs_buf_t *bp) | |
1da177e4 | 902 | { |
ce8e922c NS |
903 | XB_TRACE(bp, "lock", 0); |
904 | if (atomic_read(&bp->b_io_remaining)) | |
905 | blk_run_address_space(bp->b_target->bt_mapping); | |
906 | down(&bp->b_sema); | |
907 | XB_SET_OWNER(bp); | |
908 | XB_TRACE(bp, "locked", 0); | |
1da177e4 LT |
909 | } |
910 | ||
911 | /* | |
ce8e922c | 912 | * Releases the lock on the buffer object. |
2f926587 | 913 | * If the buffer is marked delwri but is not queued, do so before we |
ce8e922c | 914 | * unlock the buffer as we need to set flags correctly. We also need to |
2f926587 DC |
915 | * take a reference for the delwri queue because the unlocker is going to |
916 | * drop their's and they don't know we just queued it. | |
1da177e4 LT |
917 | */ |
918 | void | |
ce8e922c NS |
919 | xfs_buf_unlock( |
920 | xfs_buf_t *bp) | |
1da177e4 | 921 | { |
ce8e922c NS |
922 | if ((bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)) == XBF_DELWRI) { |
923 | atomic_inc(&bp->b_hold); | |
924 | bp->b_flags |= XBF_ASYNC; | |
925 | xfs_buf_delwri_queue(bp, 0); | |
2f926587 DC |
926 | } |
927 | ||
ce8e922c NS |
928 | XB_CLEAR_OWNER(bp); |
929 | up(&bp->b_sema); | |
930 | XB_TRACE(bp, "unlock", 0); | |
1da177e4 LT |
931 | } |
932 | ||
933 | ||
934 | /* | |
935 | * Pinning Buffer Storage in Memory | |
ce8e922c | 936 | * Ensure that no attempt to force a buffer to disk will succeed. |
1da177e4 LT |
937 | */ |
938 | void | |
ce8e922c NS |
939 | xfs_buf_pin( |
940 | xfs_buf_t *bp) | |
1da177e4 | 941 | { |
ce8e922c NS |
942 | atomic_inc(&bp->b_pin_count); |
943 | XB_TRACE(bp, "pin", (long)bp->b_pin_count.counter); | |
1da177e4 LT |
944 | } |
945 | ||
1da177e4 | 946 | void |
ce8e922c NS |
947 | xfs_buf_unpin( |
948 | xfs_buf_t *bp) | |
1da177e4 | 949 | { |
ce8e922c NS |
950 | if (atomic_dec_and_test(&bp->b_pin_count)) |
951 | wake_up_all(&bp->b_waiters); | |
952 | XB_TRACE(bp, "unpin", (long)bp->b_pin_count.counter); | |
1da177e4 LT |
953 | } |
954 | ||
955 | int | |
ce8e922c NS |
956 | xfs_buf_ispin( |
957 | xfs_buf_t *bp) | |
1da177e4 | 958 | { |
ce8e922c | 959 | return atomic_read(&bp->b_pin_count); |
1da177e4 LT |
960 | } |
961 | ||
ce8e922c NS |
962 | STATIC void |
963 | xfs_buf_wait_unpin( | |
964 | xfs_buf_t *bp) | |
1da177e4 LT |
965 | { |
966 | DECLARE_WAITQUEUE (wait, current); | |
967 | ||
ce8e922c | 968 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
969 | return; |
970 | ||
ce8e922c | 971 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
972 | for (;;) { |
973 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 974 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 975 | break; |
ce8e922c NS |
976 | if (atomic_read(&bp->b_io_remaining)) |
977 | blk_run_address_space(bp->b_target->bt_mapping); | |
1da177e4 LT |
978 | schedule(); |
979 | } | |
ce8e922c | 980 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
981 | set_current_state(TASK_RUNNING); |
982 | } | |
983 | ||
984 | /* | |
985 | * Buffer Utility Routines | |
986 | */ | |
987 | ||
1da177e4 | 988 | STATIC void |
ce8e922c | 989 | xfs_buf_iodone_work( |
1da177e4 LT |
990 | void *v) |
991 | { | |
992 | xfs_buf_t *bp = (xfs_buf_t *)v; | |
993 | ||
ce8e922c NS |
994 | if (bp->b_iodone) |
995 | (*(bp->b_iodone))(bp); | |
996 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 LT |
997 | xfs_buf_relse(bp); |
998 | } | |
999 | ||
1000 | void | |
ce8e922c NS |
1001 | xfs_buf_ioend( |
1002 | xfs_buf_t *bp, | |
1da177e4 LT |
1003 | int schedule) |
1004 | { | |
ce8e922c NS |
1005 | bp->b_flags &= ~(XBF_READ | XBF_WRITE); |
1006 | if (bp->b_error == 0) | |
1007 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1008 | |
ce8e922c | 1009 | XB_TRACE(bp, "iodone", bp->b_iodone); |
1da177e4 | 1010 | |
ce8e922c | 1011 | if ((bp->b_iodone) || (bp->b_flags & XBF_ASYNC)) { |
1da177e4 | 1012 | if (schedule) { |
ce8e922c NS |
1013 | INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work, bp); |
1014 | queue_work(xfslogd_workqueue, &bp->b_iodone_work); | |
1da177e4 | 1015 | } else { |
ce8e922c | 1016 | xfs_buf_iodone_work(bp); |
1da177e4 LT |
1017 | } |
1018 | } else { | |
ce8e922c | 1019 | up(&bp->b_iodonesema); |
1da177e4 LT |
1020 | } |
1021 | } | |
1022 | ||
1da177e4 | 1023 | void |
ce8e922c NS |
1024 | xfs_buf_ioerror( |
1025 | xfs_buf_t *bp, | |
1026 | int error) | |
1da177e4 LT |
1027 | { |
1028 | ASSERT(error >= 0 && error <= 0xffff); | |
ce8e922c NS |
1029 | bp->b_error = (unsigned short)error; |
1030 | XB_TRACE(bp, "ioerror", (unsigned long)error); | |
1da177e4 LT |
1031 | } |
1032 | ||
1033 | /* | |
ce8e922c NS |
1034 | * Initiate I/O on a buffer, based on the flags supplied. |
1035 | * The b_iodone routine in the buffer supplied will only be called | |
1da177e4 | 1036 | * when all of the subsidiary I/O requests, if any, have been completed. |
1da177e4 LT |
1037 | */ |
1038 | int | |
ce8e922c NS |
1039 | xfs_buf_iostart( |
1040 | xfs_buf_t *bp, | |
1041 | xfs_buf_flags_t flags) | |
1da177e4 LT |
1042 | { |
1043 | int status = 0; | |
1044 | ||
ce8e922c | 1045 | XB_TRACE(bp, "iostart", (unsigned long)flags); |
1da177e4 | 1046 | |
ce8e922c NS |
1047 | if (flags & XBF_DELWRI) { |
1048 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_ASYNC); | |
1049 | bp->b_flags |= flags & (XBF_DELWRI | XBF_ASYNC); | |
1050 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1051 | return status; |
1052 | } | |
1053 | ||
ce8e922c NS |
1054 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_ASYNC | XBF_DELWRI | \ |
1055 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
1056 | bp->b_flags |= flags & (XBF_READ | XBF_WRITE | XBF_ASYNC | \ | |
1057 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
1da177e4 | 1058 | |
ce8e922c | 1059 | BUG_ON(bp->b_bn == XFS_BUF_DADDR_NULL); |
1da177e4 LT |
1060 | |
1061 | /* For writes allow an alternate strategy routine to precede | |
1062 | * the actual I/O request (which may not be issued at all in | |
1063 | * a shutdown situation, for example). | |
1064 | */ | |
ce8e922c NS |
1065 | status = (flags & XBF_WRITE) ? |
1066 | xfs_buf_iostrategy(bp) : xfs_buf_iorequest(bp); | |
1da177e4 LT |
1067 | |
1068 | /* Wait for I/O if we are not an async request. | |
1069 | * Note: async I/O request completion will release the buffer, | |
1070 | * and that can already be done by this point. So using the | |
1071 | * buffer pointer from here on, after async I/O, is invalid. | |
1072 | */ | |
ce8e922c NS |
1073 | if (!status && !(flags & XBF_ASYNC)) |
1074 | status = xfs_buf_iowait(bp); | |
1da177e4 LT |
1075 | |
1076 | return status; | |
1077 | } | |
1078 | ||
1da177e4 | 1079 | STATIC __inline__ int |
ce8e922c NS |
1080 | _xfs_buf_iolocked( |
1081 | xfs_buf_t *bp) | |
1da177e4 | 1082 | { |
ce8e922c NS |
1083 | ASSERT(bp->b_flags & (XBF_READ | XBF_WRITE)); |
1084 | if (bp->b_flags & XBF_READ) | |
1085 | return bp->b_locked; | |
1da177e4 LT |
1086 | return 0; |
1087 | } | |
1088 | ||
1089 | STATIC __inline__ void | |
ce8e922c NS |
1090 | _xfs_buf_ioend( |
1091 | xfs_buf_t *bp, | |
1da177e4 LT |
1092 | int schedule) |
1093 | { | |
ce8e922c NS |
1094 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) { |
1095 | bp->b_locked = 0; | |
1096 | xfs_buf_ioend(bp, schedule); | |
1da177e4 LT |
1097 | } |
1098 | } | |
1099 | ||
1100 | STATIC int | |
ce8e922c | 1101 | xfs_buf_bio_end_io( |
1da177e4 LT |
1102 | struct bio *bio, |
1103 | unsigned int bytes_done, | |
1104 | int error) | |
1105 | { | |
ce8e922c NS |
1106 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1107 | unsigned int blocksize = bp->b_target->bt_bsize; | |
eedb5530 | 1108 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; |
1da177e4 LT |
1109 | |
1110 | if (bio->bi_size) | |
1111 | return 1; | |
1112 | ||
1113 | if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) | |
ce8e922c | 1114 | bp->b_error = EIO; |
1da177e4 | 1115 | |
eedb5530 | 1116 | do { |
1da177e4 LT |
1117 | struct page *page = bvec->bv_page; |
1118 | ||
ce8e922c NS |
1119 | if (unlikely(bp->b_error)) { |
1120 | if (bp->b_flags & XBF_READ) | |
eedb5530 | 1121 | ClearPageUptodate(page); |
1da177e4 | 1122 | SetPageError(page); |
ce8e922c | 1123 | } else if (blocksize >= PAGE_CACHE_SIZE) { |
1da177e4 LT |
1124 | SetPageUptodate(page); |
1125 | } else if (!PagePrivate(page) && | |
ce8e922c | 1126 | (bp->b_flags & _XBF_PAGE_CACHE)) { |
1da177e4 LT |
1127 | set_page_region(page, bvec->bv_offset, bvec->bv_len); |
1128 | } | |
1129 | ||
eedb5530 NS |
1130 | if (--bvec >= bio->bi_io_vec) |
1131 | prefetchw(&bvec->bv_page->flags); | |
1132 | ||
ce8e922c | 1133 | if (_xfs_buf_iolocked(bp)) { |
1da177e4 LT |
1134 | unlock_page(page); |
1135 | } | |
eedb5530 | 1136 | } while (bvec >= bio->bi_io_vec); |
1da177e4 | 1137 | |
ce8e922c | 1138 | _xfs_buf_ioend(bp, 1); |
1da177e4 LT |
1139 | bio_put(bio); |
1140 | return 0; | |
1141 | } | |
1142 | ||
1143 | STATIC void | |
ce8e922c NS |
1144 | _xfs_buf_ioapply( |
1145 | xfs_buf_t *bp) | |
1da177e4 LT |
1146 | { |
1147 | int i, rw, map_i, total_nr_pages, nr_pages; | |
1148 | struct bio *bio; | |
ce8e922c NS |
1149 | int offset = bp->b_offset; |
1150 | int size = bp->b_count_desired; | |
1151 | sector_t sector = bp->b_bn; | |
1152 | unsigned int blocksize = bp->b_target->bt_bsize; | |
1153 | int locking = _xfs_buf_iolocked(bp); | |
1da177e4 | 1154 | |
ce8e922c | 1155 | total_nr_pages = bp->b_page_count; |
1da177e4 LT |
1156 | map_i = 0; |
1157 | ||
ce8e922c NS |
1158 | if (bp->b_flags & _XBF_RUN_QUEUES) { |
1159 | bp->b_flags &= ~_XBF_RUN_QUEUES; | |
1160 | rw = (bp->b_flags & XBF_READ) ? READ_SYNC : WRITE_SYNC; | |
1da177e4 | 1161 | } else { |
ce8e922c | 1162 | rw = (bp->b_flags & XBF_READ) ? READ : WRITE; |
1da177e4 LT |
1163 | } |
1164 | ||
ce8e922c NS |
1165 | if (bp->b_flags & XBF_ORDERED) { |
1166 | ASSERT(!(bp->b_flags & XBF_READ)); | |
f538d4da CH |
1167 | rw = WRITE_BARRIER; |
1168 | } | |
1169 | ||
ce8e922c | 1170 | /* Special code path for reading a sub page size buffer in -- |
1da177e4 LT |
1171 | * we populate up the whole page, and hence the other metadata |
1172 | * in the same page. This optimization is only valid when the | |
ce8e922c | 1173 | * filesystem block size is not smaller than the page size. |
1da177e4 | 1174 | */ |
ce8e922c NS |
1175 | if ((bp->b_buffer_length < PAGE_CACHE_SIZE) && |
1176 | (bp->b_flags & XBF_READ) && locking && | |
1177 | (blocksize >= PAGE_CACHE_SIZE)) { | |
1da177e4 LT |
1178 | bio = bio_alloc(GFP_NOIO, 1); |
1179 | ||
ce8e922c | 1180 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1181 | bio->bi_sector = sector - (offset >> BBSHIFT); |
ce8e922c NS |
1182 | bio->bi_end_io = xfs_buf_bio_end_io; |
1183 | bio->bi_private = bp; | |
1da177e4 | 1184 | |
ce8e922c | 1185 | bio_add_page(bio, bp->b_pages[0], PAGE_CACHE_SIZE, 0); |
1da177e4 LT |
1186 | size = 0; |
1187 | ||
ce8e922c | 1188 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1189 | |
1190 | goto submit_io; | |
1191 | } | |
1192 | ||
1193 | /* Lock down the pages which we need to for the request */ | |
ce8e922c | 1194 | if (locking && (bp->b_flags & XBF_WRITE) && (bp->b_locked == 0)) { |
1da177e4 LT |
1195 | for (i = 0; size; i++) { |
1196 | int nbytes = PAGE_CACHE_SIZE - offset; | |
ce8e922c | 1197 | struct page *page = bp->b_pages[i]; |
1da177e4 LT |
1198 | |
1199 | if (nbytes > size) | |
1200 | nbytes = size; | |
1201 | ||
1202 | lock_page(page); | |
1203 | ||
1204 | size -= nbytes; | |
1205 | offset = 0; | |
1206 | } | |
ce8e922c NS |
1207 | offset = bp->b_offset; |
1208 | size = bp->b_count_desired; | |
1da177e4 LT |
1209 | } |
1210 | ||
1211 | next_chunk: | |
ce8e922c | 1212 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1213 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1214 | if (nr_pages > total_nr_pages) | |
1215 | nr_pages = total_nr_pages; | |
1216 | ||
1217 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1218 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1219 | bio->bi_sector = sector; |
ce8e922c NS |
1220 | bio->bi_end_io = xfs_buf_bio_end_io; |
1221 | bio->bi_private = bp; | |
1da177e4 LT |
1222 | |
1223 | for (; size && nr_pages; nr_pages--, map_i++) { | |
ce8e922c | 1224 | int rbytes, nbytes = PAGE_CACHE_SIZE - offset; |
1da177e4 LT |
1225 | |
1226 | if (nbytes > size) | |
1227 | nbytes = size; | |
1228 | ||
ce8e922c NS |
1229 | rbytes = bio_add_page(bio, bp->b_pages[map_i], nbytes, offset); |
1230 | if (rbytes < nbytes) | |
1da177e4 LT |
1231 | break; |
1232 | ||
1233 | offset = 0; | |
1234 | sector += nbytes >> BBSHIFT; | |
1235 | size -= nbytes; | |
1236 | total_nr_pages--; | |
1237 | } | |
1238 | ||
1239 | submit_io: | |
1240 | if (likely(bio->bi_size)) { | |
1241 | submit_bio(rw, bio); | |
1242 | if (size) | |
1243 | goto next_chunk; | |
1244 | } else { | |
1245 | bio_put(bio); | |
ce8e922c | 1246 | xfs_buf_ioerror(bp, EIO); |
1da177e4 LT |
1247 | } |
1248 | } | |
1249 | ||
1da177e4 | 1250 | int |
ce8e922c NS |
1251 | xfs_buf_iorequest( |
1252 | xfs_buf_t *bp) | |
1da177e4 | 1253 | { |
ce8e922c | 1254 | XB_TRACE(bp, "iorequest", 0); |
1da177e4 | 1255 | |
ce8e922c NS |
1256 | if (bp->b_flags & XBF_DELWRI) { |
1257 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1258 | return 0; |
1259 | } | |
1260 | ||
ce8e922c NS |
1261 | if (bp->b_flags & XBF_WRITE) { |
1262 | xfs_buf_wait_unpin(bp); | |
1da177e4 LT |
1263 | } |
1264 | ||
ce8e922c | 1265 | xfs_buf_hold(bp); |
1da177e4 LT |
1266 | |
1267 | /* Set the count to 1 initially, this will stop an I/O | |
1268 | * completion callout which happens before we have started | |
ce8e922c | 1269 | * all the I/O from calling xfs_buf_ioend too early. |
1da177e4 | 1270 | */ |
ce8e922c NS |
1271 | atomic_set(&bp->b_io_remaining, 1); |
1272 | _xfs_buf_ioapply(bp); | |
1273 | _xfs_buf_ioend(bp, 0); | |
1da177e4 | 1274 | |
ce8e922c | 1275 | xfs_buf_rele(bp); |
1da177e4 LT |
1276 | return 0; |
1277 | } | |
1278 | ||
1279 | /* | |
ce8e922c NS |
1280 | * Waits for I/O to complete on the buffer supplied. |
1281 | * It returns immediately if no I/O is pending. | |
1282 | * It returns the I/O error code, if any, or 0 if there was no error. | |
1da177e4 LT |
1283 | */ |
1284 | int | |
ce8e922c NS |
1285 | xfs_buf_iowait( |
1286 | xfs_buf_t *bp) | |
1da177e4 | 1287 | { |
ce8e922c NS |
1288 | XB_TRACE(bp, "iowait", 0); |
1289 | if (atomic_read(&bp->b_io_remaining)) | |
1290 | blk_run_address_space(bp->b_target->bt_mapping); | |
1291 | down(&bp->b_iodonesema); | |
1292 | XB_TRACE(bp, "iowaited", (long)bp->b_error); | |
1293 | return bp->b_error; | |
1da177e4 LT |
1294 | } |
1295 | ||
ce8e922c NS |
1296 | xfs_caddr_t |
1297 | xfs_buf_offset( | |
1298 | xfs_buf_t *bp, | |
1da177e4 LT |
1299 | size_t offset) |
1300 | { | |
1301 | struct page *page; | |
1302 | ||
ce8e922c NS |
1303 | if (bp->b_flags & XBF_MAPPED) |
1304 | return XFS_BUF_PTR(bp) + offset; | |
1da177e4 | 1305 | |
ce8e922c NS |
1306 | offset += bp->b_offset; |
1307 | page = bp->b_pages[offset >> PAGE_CACHE_SHIFT]; | |
1308 | return (xfs_caddr_t)page_address(page) + (offset & (PAGE_CACHE_SIZE-1)); | |
1da177e4 LT |
1309 | } |
1310 | ||
1311 | /* | |
1da177e4 LT |
1312 | * Move data into or out of a buffer. |
1313 | */ | |
1314 | void | |
ce8e922c NS |
1315 | xfs_buf_iomove( |
1316 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1317 | size_t boff, /* starting buffer offset */ |
1318 | size_t bsize, /* length to copy */ | |
1319 | caddr_t data, /* data address */ | |
ce8e922c | 1320 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 LT |
1321 | { |
1322 | size_t bend, cpoff, csize; | |
1323 | struct page *page; | |
1324 | ||
1325 | bend = boff + bsize; | |
1326 | while (boff < bend) { | |
ce8e922c NS |
1327 | page = bp->b_pages[xfs_buf_btoct(boff + bp->b_offset)]; |
1328 | cpoff = xfs_buf_poff(boff + bp->b_offset); | |
1da177e4 | 1329 | csize = min_t(size_t, |
ce8e922c | 1330 | PAGE_CACHE_SIZE-cpoff, bp->b_count_desired-boff); |
1da177e4 LT |
1331 | |
1332 | ASSERT(((csize + cpoff) <= PAGE_CACHE_SIZE)); | |
1333 | ||
1334 | switch (mode) { | |
ce8e922c | 1335 | case XBRW_ZERO: |
1da177e4 LT |
1336 | memset(page_address(page) + cpoff, 0, csize); |
1337 | break; | |
ce8e922c | 1338 | case XBRW_READ: |
1da177e4 LT |
1339 | memcpy(data, page_address(page) + cpoff, csize); |
1340 | break; | |
ce8e922c | 1341 | case XBRW_WRITE: |
1da177e4 LT |
1342 | memcpy(page_address(page) + cpoff, data, csize); |
1343 | } | |
1344 | ||
1345 | boff += csize; | |
1346 | data += csize; | |
1347 | } | |
1348 | } | |
1349 | ||
1350 | /* | |
ce8e922c | 1351 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1352 | */ |
1353 | ||
1354 | /* | |
ce8e922c NS |
1355 | * Wait for any bufs with callbacks that have been submitted but |
1356 | * have not yet returned... walk the hash list for the target. | |
1da177e4 LT |
1357 | */ |
1358 | void | |
1359 | xfs_wait_buftarg( | |
1360 | xfs_buftarg_t *btp) | |
1361 | { | |
1362 | xfs_buf_t *bp, *n; | |
1363 | xfs_bufhash_t *hash; | |
1364 | uint i; | |
1365 | ||
1366 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { | |
1367 | hash = &btp->bt_hash[i]; | |
1368 | again: | |
1369 | spin_lock(&hash->bh_lock); | |
ce8e922c NS |
1370 | list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) { |
1371 | ASSERT(btp == bp->b_target); | |
1372 | if (!(bp->b_flags & XBF_FS_MANAGED)) { | |
1da177e4 | 1373 | spin_unlock(&hash->bh_lock); |
2f926587 DC |
1374 | /* |
1375 | * Catch superblock reference count leaks | |
1376 | * immediately | |
1377 | */ | |
ce8e922c | 1378 | BUG_ON(bp->b_bn == 0); |
1da177e4 LT |
1379 | delay(100); |
1380 | goto again; | |
1381 | } | |
1382 | } | |
1383 | spin_unlock(&hash->bh_lock); | |
1384 | } | |
1385 | } | |
1386 | ||
1387 | /* | |
ce8e922c NS |
1388 | * Allocate buffer hash table for a given target. |
1389 | * For devices containing metadata (i.e. not the log/realtime devices) | |
1390 | * we need to allocate a much larger hash table. | |
1da177e4 LT |
1391 | */ |
1392 | STATIC void | |
1393 | xfs_alloc_bufhash( | |
1394 | xfs_buftarg_t *btp, | |
1395 | int external) | |
1396 | { | |
1397 | unsigned int i; | |
1398 | ||
1399 | btp->bt_hashshift = external ? 3 : 8; /* 8 or 256 buckets */ | |
1400 | btp->bt_hashmask = (1 << btp->bt_hashshift) - 1; | |
1401 | btp->bt_hash = kmem_zalloc((1 << btp->bt_hashshift) * | |
1402 | sizeof(xfs_bufhash_t), KM_SLEEP); | |
1403 | for (i = 0; i < (1 << btp->bt_hashshift); i++) { | |
1404 | spin_lock_init(&btp->bt_hash[i].bh_lock); | |
1405 | INIT_LIST_HEAD(&btp->bt_hash[i].bh_list); | |
1406 | } | |
1407 | } | |
1408 | ||
1409 | STATIC void | |
1410 | xfs_free_bufhash( | |
1411 | xfs_buftarg_t *btp) | |
1412 | { | |
ce8e922c | 1413 | kmem_free(btp->bt_hash, (1<<btp->bt_hashshift) * sizeof(xfs_bufhash_t)); |
1da177e4 LT |
1414 | btp->bt_hash = NULL; |
1415 | } | |
1416 | ||
a6867a68 | 1417 | /* |
ce8e922c | 1418 | * buftarg list for delwrite queue processing |
a6867a68 DC |
1419 | */ |
1420 | STATIC LIST_HEAD(xfs_buftarg_list); | |
1421 | STATIC DEFINE_SPINLOCK(xfs_buftarg_lock); | |
1422 | ||
1423 | STATIC void | |
1424 | xfs_register_buftarg( | |
1425 | xfs_buftarg_t *btp) | |
1426 | { | |
1427 | spin_lock(&xfs_buftarg_lock); | |
1428 | list_add(&btp->bt_list, &xfs_buftarg_list); | |
1429 | spin_unlock(&xfs_buftarg_lock); | |
1430 | } | |
1431 | ||
1432 | STATIC void | |
1433 | xfs_unregister_buftarg( | |
1434 | xfs_buftarg_t *btp) | |
1435 | { | |
1436 | spin_lock(&xfs_buftarg_lock); | |
1437 | list_del(&btp->bt_list); | |
1438 | spin_unlock(&xfs_buftarg_lock); | |
1439 | } | |
1440 | ||
1da177e4 LT |
1441 | void |
1442 | xfs_free_buftarg( | |
1443 | xfs_buftarg_t *btp, | |
1444 | int external) | |
1445 | { | |
1446 | xfs_flush_buftarg(btp, 1); | |
1447 | if (external) | |
ce8e922c | 1448 | xfs_blkdev_put(btp->bt_bdev); |
1da177e4 | 1449 | xfs_free_bufhash(btp); |
ce8e922c | 1450 | iput(btp->bt_mapping->host); |
a6867a68 | 1451 | |
ce8e922c NS |
1452 | /* Unregister the buftarg first so that we don't get a |
1453 | * wakeup finding a non-existent task | |
1454 | */ | |
a6867a68 DC |
1455 | xfs_unregister_buftarg(btp); |
1456 | kthread_stop(btp->bt_task); | |
1457 | ||
1da177e4 LT |
1458 | kmem_free(btp, sizeof(*btp)); |
1459 | } | |
1460 | ||
1da177e4 LT |
1461 | STATIC int |
1462 | xfs_setsize_buftarg_flags( | |
1463 | xfs_buftarg_t *btp, | |
1464 | unsigned int blocksize, | |
1465 | unsigned int sectorsize, | |
1466 | int verbose) | |
1467 | { | |
ce8e922c NS |
1468 | btp->bt_bsize = blocksize; |
1469 | btp->bt_sshift = ffs(sectorsize) - 1; | |
1470 | btp->bt_smask = sectorsize - 1; | |
1da177e4 | 1471 | |
ce8e922c | 1472 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
1da177e4 LT |
1473 | printk(KERN_WARNING |
1474 | "XFS: Cannot set_blocksize to %u on device %s\n", | |
1475 | sectorsize, XFS_BUFTARG_NAME(btp)); | |
1476 | return EINVAL; | |
1477 | } | |
1478 | ||
1479 | if (verbose && | |
1480 | (PAGE_CACHE_SIZE / BITS_PER_LONG) > sectorsize) { | |
1481 | printk(KERN_WARNING | |
1482 | "XFS: %u byte sectors in use on device %s. " | |
1483 | "This is suboptimal; %u or greater is ideal.\n", | |
1484 | sectorsize, XFS_BUFTARG_NAME(btp), | |
1485 | (unsigned int)PAGE_CACHE_SIZE / BITS_PER_LONG); | |
1486 | } | |
1487 | ||
1488 | return 0; | |
1489 | } | |
1490 | ||
1491 | /* | |
ce8e922c NS |
1492 | * When allocating the initial buffer target we have not yet |
1493 | * read in the superblock, so don't know what sized sectors | |
1494 | * are being used is at this early stage. Play safe. | |
1495 | */ | |
1da177e4 LT |
1496 | STATIC int |
1497 | xfs_setsize_buftarg_early( | |
1498 | xfs_buftarg_t *btp, | |
1499 | struct block_device *bdev) | |
1500 | { | |
1501 | return xfs_setsize_buftarg_flags(btp, | |
1502 | PAGE_CACHE_SIZE, bdev_hardsect_size(bdev), 0); | |
1503 | } | |
1504 | ||
1505 | int | |
1506 | xfs_setsize_buftarg( | |
1507 | xfs_buftarg_t *btp, | |
1508 | unsigned int blocksize, | |
1509 | unsigned int sectorsize) | |
1510 | { | |
1511 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | |
1512 | } | |
1513 | ||
1514 | STATIC int | |
1515 | xfs_mapping_buftarg( | |
1516 | xfs_buftarg_t *btp, | |
1517 | struct block_device *bdev) | |
1518 | { | |
1519 | struct backing_dev_info *bdi; | |
1520 | struct inode *inode; | |
1521 | struct address_space *mapping; | |
1522 | static struct address_space_operations mapping_aops = { | |
1523 | .sync_page = block_sync_page, | |
1524 | }; | |
1525 | ||
1526 | inode = new_inode(bdev->bd_inode->i_sb); | |
1527 | if (!inode) { | |
1528 | printk(KERN_WARNING | |
1529 | "XFS: Cannot allocate mapping inode for device %s\n", | |
1530 | XFS_BUFTARG_NAME(btp)); | |
1531 | return ENOMEM; | |
1532 | } | |
1533 | inode->i_mode = S_IFBLK; | |
1534 | inode->i_bdev = bdev; | |
1535 | inode->i_rdev = bdev->bd_dev; | |
1536 | bdi = blk_get_backing_dev_info(bdev); | |
1537 | if (!bdi) | |
1538 | bdi = &default_backing_dev_info; | |
1539 | mapping = &inode->i_data; | |
1540 | mapping->a_ops = &mapping_aops; | |
1541 | mapping->backing_dev_info = bdi; | |
1542 | mapping_set_gfp_mask(mapping, GFP_NOFS); | |
ce8e922c | 1543 | btp->bt_mapping = mapping; |
1da177e4 LT |
1544 | return 0; |
1545 | } | |
1546 | ||
a6867a68 DC |
1547 | STATIC int |
1548 | xfs_alloc_delwrite_queue( | |
1549 | xfs_buftarg_t *btp) | |
1550 | { | |
1551 | int error = 0; | |
1552 | ||
1553 | INIT_LIST_HEAD(&btp->bt_list); | |
1554 | INIT_LIST_HEAD(&btp->bt_delwrite_queue); | |
1555 | spinlock_init(&btp->bt_delwrite_lock, "delwri_lock"); | |
1556 | btp->bt_flags = 0; | |
1557 | btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd"); | |
1558 | if (IS_ERR(btp->bt_task)) { | |
1559 | error = PTR_ERR(btp->bt_task); | |
1560 | goto out_error; | |
1561 | } | |
1562 | xfs_register_buftarg(btp); | |
1563 | out_error: | |
1564 | return error; | |
1565 | } | |
1566 | ||
1da177e4 LT |
1567 | xfs_buftarg_t * |
1568 | xfs_alloc_buftarg( | |
1569 | struct block_device *bdev, | |
1570 | int external) | |
1571 | { | |
1572 | xfs_buftarg_t *btp; | |
1573 | ||
1574 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP); | |
1575 | ||
ce8e922c NS |
1576 | btp->bt_dev = bdev->bd_dev; |
1577 | btp->bt_bdev = bdev; | |
1da177e4 LT |
1578 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1579 | goto error; | |
1580 | if (xfs_mapping_buftarg(btp, bdev)) | |
1581 | goto error; | |
a6867a68 DC |
1582 | if (xfs_alloc_delwrite_queue(btp)) |
1583 | goto error; | |
1da177e4 LT |
1584 | xfs_alloc_bufhash(btp, external); |
1585 | return btp; | |
1586 | ||
1587 | error: | |
1588 | kmem_free(btp, sizeof(*btp)); | |
1589 | return NULL; | |
1590 | } | |
1591 | ||
1592 | ||
1593 | /* | |
ce8e922c | 1594 | * Delayed write buffer handling |
1da177e4 | 1595 | */ |
1da177e4 | 1596 | STATIC void |
ce8e922c NS |
1597 | xfs_buf_delwri_queue( |
1598 | xfs_buf_t *bp, | |
1da177e4 LT |
1599 | int unlock) |
1600 | { | |
ce8e922c NS |
1601 | struct list_head *dwq = &bp->b_target->bt_delwrite_queue; |
1602 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; | |
a6867a68 | 1603 | |
ce8e922c NS |
1604 | XB_TRACE(bp, "delwri_q", (long)unlock); |
1605 | ASSERT((bp->b_flags&(XBF_DELWRI|XBF_ASYNC)) == (XBF_DELWRI|XBF_ASYNC)); | |
1da177e4 | 1606 | |
a6867a68 | 1607 | spin_lock(dwlk); |
1da177e4 | 1608 | /* If already in the queue, dequeue and place at tail */ |
ce8e922c NS |
1609 | if (!list_empty(&bp->b_list)) { |
1610 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1611 | if (unlock) | |
1612 | atomic_dec(&bp->b_hold); | |
1613 | list_del(&bp->b_list); | |
1da177e4 LT |
1614 | } |
1615 | ||
ce8e922c NS |
1616 | bp->b_flags |= _XBF_DELWRI_Q; |
1617 | list_add_tail(&bp->b_list, dwq); | |
1618 | bp->b_queuetime = jiffies; | |
a6867a68 | 1619 | spin_unlock(dwlk); |
1da177e4 LT |
1620 | |
1621 | if (unlock) | |
ce8e922c | 1622 | xfs_buf_unlock(bp); |
1da177e4 LT |
1623 | } |
1624 | ||
1625 | void | |
ce8e922c NS |
1626 | xfs_buf_delwri_dequeue( |
1627 | xfs_buf_t *bp) | |
1da177e4 | 1628 | { |
ce8e922c | 1629 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; |
1da177e4 LT |
1630 | int dequeued = 0; |
1631 | ||
a6867a68 | 1632 | spin_lock(dwlk); |
ce8e922c NS |
1633 | if ((bp->b_flags & XBF_DELWRI) && !list_empty(&bp->b_list)) { |
1634 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1635 | list_del_init(&bp->b_list); | |
1da177e4 LT |
1636 | dequeued = 1; |
1637 | } | |
ce8e922c | 1638 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); |
a6867a68 | 1639 | spin_unlock(dwlk); |
1da177e4 LT |
1640 | |
1641 | if (dequeued) | |
ce8e922c | 1642 | xfs_buf_rele(bp); |
1da177e4 | 1643 | |
ce8e922c | 1644 | XB_TRACE(bp, "delwri_dq", (long)dequeued); |
1da177e4 LT |
1645 | } |
1646 | ||
1647 | STATIC void | |
ce8e922c | 1648 | xfs_buf_runall_queues( |
1da177e4 LT |
1649 | struct workqueue_struct *queue) |
1650 | { | |
1651 | flush_workqueue(queue); | |
1652 | } | |
1653 | ||
1da177e4 | 1654 | STATIC int |
23ea4032 | 1655 | xfsbufd_wakeup( |
15c84a47 NS |
1656 | int priority, |
1657 | gfp_t mask) | |
1da177e4 | 1658 | { |
da7f93e9 | 1659 | xfs_buftarg_t *btp; |
a6867a68 DC |
1660 | |
1661 | spin_lock(&xfs_buftarg_lock); | |
da7f93e9 | 1662 | list_for_each_entry(btp, &xfs_buftarg_list, bt_list) { |
ce8e922c | 1663 | if (test_bit(XBT_FORCE_SLEEP, &btp->bt_flags)) |
a6867a68 | 1664 | continue; |
ce8e922c | 1665 | set_bit(XBT_FORCE_FLUSH, &btp->bt_flags); |
a6867a68 DC |
1666 | wake_up_process(btp->bt_task); |
1667 | } | |
1668 | spin_unlock(&xfs_buftarg_lock); | |
1da177e4 LT |
1669 | return 0; |
1670 | } | |
1671 | ||
1672 | STATIC int | |
23ea4032 | 1673 | xfsbufd( |
1da177e4 LT |
1674 | void *data) |
1675 | { | |
1676 | struct list_head tmp; | |
1677 | unsigned long age; | |
a6867a68 | 1678 | xfs_buftarg_t *target = (xfs_buftarg_t *)data; |
ce8e922c | 1679 | xfs_buf_t *bp, *n; |
a6867a68 DC |
1680 | struct list_head *dwq = &target->bt_delwrite_queue; |
1681 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1da177e4 | 1682 | |
1da177e4 LT |
1683 | current->flags |= PF_MEMALLOC; |
1684 | ||
1da177e4 LT |
1685 | INIT_LIST_HEAD(&tmp); |
1686 | do { | |
3e1d1d28 | 1687 | if (unlikely(freezing(current))) { |
ce8e922c | 1688 | set_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
3e1d1d28 | 1689 | refrigerator(); |
abd0cf7a | 1690 | } else { |
ce8e922c | 1691 | clear_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
abd0cf7a | 1692 | } |
1da177e4 | 1693 | |
15c84a47 NS |
1694 | schedule_timeout_interruptible( |
1695 | xfs_buf_timer_centisecs * msecs_to_jiffies(10)); | |
1da177e4 | 1696 | |
041e0e3b | 1697 | age = xfs_buf_age_centisecs * msecs_to_jiffies(10); |
a6867a68 | 1698 | spin_lock(dwlk); |
ce8e922c NS |
1699 | list_for_each_entry_safe(bp, n, dwq, b_list) { |
1700 | XB_TRACE(bp, "walkq1", (long)xfs_buf_ispin(bp)); | |
1701 | ASSERT(bp->b_flags & XBF_DELWRI); | |
1da177e4 | 1702 | |
ce8e922c NS |
1703 | if (!xfs_buf_ispin(bp) && !xfs_buf_cond_lock(bp)) { |
1704 | if (!test_bit(XBT_FORCE_FLUSH, | |
a6867a68 | 1705 | &target->bt_flags) && |
1da177e4 | 1706 | time_before(jiffies, |
ce8e922c NS |
1707 | bp->b_queuetime + age)) { |
1708 | xfs_buf_unlock(bp); | |
1da177e4 LT |
1709 | break; |
1710 | } | |
1711 | ||
ce8e922c NS |
1712 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); |
1713 | bp->b_flags |= XBF_WRITE; | |
1714 | list_move(&bp->b_list, &tmp); | |
1da177e4 LT |
1715 | } |
1716 | } | |
a6867a68 | 1717 | spin_unlock(dwlk); |
1da177e4 LT |
1718 | |
1719 | while (!list_empty(&tmp)) { | |
ce8e922c NS |
1720 | bp = list_entry(tmp.next, xfs_buf_t, b_list); |
1721 | ASSERT(target == bp->b_target); | |
1da177e4 | 1722 | |
ce8e922c NS |
1723 | list_del_init(&bp->b_list); |
1724 | xfs_buf_iostrategy(bp); | |
1da177e4 | 1725 | |
ce8e922c | 1726 | blk_run_address_space(target->bt_mapping); |
1da177e4 LT |
1727 | } |
1728 | ||
1729 | if (as_list_len > 0) | |
1730 | purge_addresses(); | |
1731 | ||
ce8e922c | 1732 | clear_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
4df08c52 | 1733 | } while (!kthread_should_stop()); |
1da177e4 | 1734 | |
4df08c52 | 1735 | return 0; |
1da177e4 LT |
1736 | } |
1737 | ||
1738 | /* | |
ce8e922c NS |
1739 | * Go through all incore buffers, and release buffers if they belong to |
1740 | * the given device. This is used in filesystem error handling to | |
1741 | * preserve the consistency of its metadata. | |
1da177e4 LT |
1742 | */ |
1743 | int | |
1744 | xfs_flush_buftarg( | |
1745 | xfs_buftarg_t *target, | |
1746 | int wait) | |
1747 | { | |
1748 | struct list_head tmp; | |
ce8e922c | 1749 | xfs_buf_t *bp, *n; |
1da177e4 | 1750 | int pincount = 0; |
a6867a68 DC |
1751 | struct list_head *dwq = &target->bt_delwrite_queue; |
1752 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1da177e4 | 1753 | |
ce8e922c NS |
1754 | xfs_buf_runall_queues(xfsdatad_workqueue); |
1755 | xfs_buf_runall_queues(xfslogd_workqueue); | |
1da177e4 LT |
1756 | |
1757 | INIT_LIST_HEAD(&tmp); | |
a6867a68 | 1758 | spin_lock(dwlk); |
ce8e922c NS |
1759 | list_for_each_entry_safe(bp, n, dwq, b_list) { |
1760 | ASSERT(bp->b_target == target); | |
1761 | ASSERT(bp->b_flags & (XBF_DELWRI | _XBF_DELWRI_Q)); | |
1762 | XB_TRACE(bp, "walkq2", (long)xfs_buf_ispin(bp)); | |
1763 | if (xfs_buf_ispin(bp)) { | |
1da177e4 LT |
1764 | pincount++; |
1765 | continue; | |
1766 | } | |
1767 | ||
ce8e922c | 1768 | list_move(&bp->b_list, &tmp); |
1da177e4 | 1769 | } |
a6867a68 | 1770 | spin_unlock(dwlk); |
1da177e4 LT |
1771 | |
1772 | /* | |
1773 | * Dropped the delayed write list lock, now walk the temporary list | |
1774 | */ | |
ce8e922c NS |
1775 | list_for_each_entry_safe(bp, n, &tmp, b_list) { |
1776 | xfs_buf_lock(bp); | |
1777 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); | |
1778 | bp->b_flags |= XBF_WRITE; | |
1da177e4 | 1779 | if (wait) |
ce8e922c | 1780 | bp->b_flags &= ~XBF_ASYNC; |
1da177e4 | 1781 | else |
ce8e922c | 1782 | list_del_init(&bp->b_list); |
1da177e4 | 1783 | |
ce8e922c | 1784 | xfs_buf_iostrategy(bp); |
1da177e4 LT |
1785 | } |
1786 | ||
1787 | /* | |
1788 | * Remaining list items must be flushed before returning | |
1789 | */ | |
1790 | while (!list_empty(&tmp)) { | |
ce8e922c | 1791 | bp = list_entry(tmp.next, xfs_buf_t, b_list); |
1da177e4 | 1792 | |
ce8e922c NS |
1793 | list_del_init(&bp->b_list); |
1794 | xfs_iowait(bp); | |
1795 | xfs_buf_relse(bp); | |
1da177e4 LT |
1796 | } |
1797 | ||
1798 | if (wait) | |
ce8e922c | 1799 | blk_run_address_space(target->bt_mapping); |
1da177e4 LT |
1800 | |
1801 | return pincount; | |
1802 | } | |
1803 | ||
04d8b284 | 1804 | int __init |
ce8e922c | 1805 | xfs_buf_init(void) |
1da177e4 | 1806 | { |
23ea4032 | 1807 | int error = -ENOMEM; |
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 | ||
ce8e922c NS |
1813 | xfs_buf_zone = kmem_zone_init(sizeof(xfs_buf_t), "xfs_buf"); |
1814 | if (!xfs_buf_zone) | |
04d8b284 CH |
1815 | goto out_free_trace_buf; |
1816 | ||
23ea4032 CH |
1817 | xfslogd_workqueue = create_workqueue("xfslogd"); |
1818 | if (!xfslogd_workqueue) | |
04d8b284 | 1819 | goto out_free_buf_zone; |
1da177e4 | 1820 | |
23ea4032 CH |
1821 | xfsdatad_workqueue = create_workqueue("xfsdatad"); |
1822 | if (!xfsdatad_workqueue) | |
1823 | goto out_destroy_xfslogd_workqueue; | |
1da177e4 | 1824 | |
ce8e922c NS |
1825 | xfs_buf_shake = kmem_shake_register(xfsbufd_wakeup); |
1826 | if (!xfs_buf_shake) | |
a6867a68 | 1827 | goto out_destroy_xfsdatad_workqueue; |
04d8b284 | 1828 | |
23ea4032 | 1829 | return 0; |
1da177e4 | 1830 | |
23ea4032 CH |
1831 | out_destroy_xfsdatad_workqueue: |
1832 | destroy_workqueue(xfsdatad_workqueue); | |
1833 | out_destroy_xfslogd_workqueue: | |
1834 | destroy_workqueue(xfslogd_workqueue); | |
23ea4032 | 1835 | out_free_buf_zone: |
ce8e922c | 1836 | kmem_zone_destroy(xfs_buf_zone); |
04d8b284 | 1837 | out_free_trace_buf: |
ce8e922c NS |
1838 | #ifdef XFS_BUF_TRACE |
1839 | ktrace_free(xfs_buf_trace_buf); | |
23ea4032 | 1840 | #endif |
23ea4032 | 1841 | return error; |
1da177e4 LT |
1842 | } |
1843 | ||
1da177e4 | 1844 | void |
ce8e922c | 1845 | xfs_buf_terminate(void) |
1da177e4 | 1846 | { |
ce8e922c | 1847 | kmem_shake_deregister(xfs_buf_shake); |
04d8b284 CH |
1848 | destroy_workqueue(xfsdatad_workqueue); |
1849 | destroy_workqueue(xfslogd_workqueue); | |
ce8e922c NS |
1850 | kmem_zone_destroy(xfs_buf_zone); |
1851 | #ifdef XFS_BUF_TRACE | |
1852 | ktrace_free(xfs_buf_trace_buf); | |
1da177e4 | 1853 | #endif |
1da177e4 | 1854 | } |