Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
f07c2250 | 2 | * Copyright (c) 2000-2006 Silicon Graphics, Inc. |
7b718769 | 3 | * All Rights Reserved. |
1da177e4 | 4 | * |
7b718769 NS |
5 | * This program is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU General Public License as | |
1da177e4 LT |
7 | * published by the Free Software Foundation. |
8 | * | |
7b718769 NS |
9 | * This program is distributed in the hope that it would be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
1da177e4 | 13 | * |
7b718769 NS |
14 | * You should have received a copy of the GNU General Public License |
15 | * along with this program; if not, write the Free Software Foundation, | |
16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
1da177e4 | 17 | */ |
93c189c1 | 18 | #include "xfs.h" |
1da177e4 LT |
19 | #include <linux/stddef.h> |
20 | #include <linux/errno.h> | |
5a0e3ad6 | 21 | #include <linux/gfp.h> |
1da177e4 LT |
22 | #include <linux/pagemap.h> |
23 | #include <linux/init.h> | |
24 | #include <linux/vmalloc.h> | |
25 | #include <linux/bio.h> | |
26 | #include <linux/sysctl.h> | |
27 | #include <linux/proc_fs.h> | |
28 | #include <linux/workqueue.h> | |
29 | #include <linux/percpu.h> | |
30 | #include <linux/blkdev.h> | |
31 | #include <linux/hash.h> | |
4df08c52 | 32 | #include <linux/kthread.h> |
b20a3503 | 33 | #include <linux/migrate.h> |
3fcfab16 | 34 | #include <linux/backing-dev.h> |
7dfb7103 | 35 | #include <linux/freezer.h> |
089716aa | 36 | #include <linux/list_sort.h> |
1da177e4 | 37 | |
b7963133 CH |
38 | #include "xfs_sb.h" |
39 | #include "xfs_inum.h" | |
ed3b4d6c | 40 | #include "xfs_log.h" |
b7963133 | 41 | #include "xfs_ag.h" |
b7963133 | 42 | #include "xfs_mount.h" |
0b1b213f | 43 | #include "xfs_trace.h" |
b7963133 | 44 | |
7989cb8e | 45 | static kmem_zone_t *xfs_buf_zone; |
a6867a68 | 46 | STATIC int xfsbufd(void *); |
ce8e922c | 47 | STATIC void xfs_buf_delwri_queue(xfs_buf_t *, int); |
23ea4032 | 48 | |
7989cb8e | 49 | static struct workqueue_struct *xfslogd_workqueue; |
0829c360 | 50 | struct workqueue_struct *xfsdatad_workqueue; |
c626d174 | 51 | struct workqueue_struct *xfsconvertd_workqueue; |
1da177e4 | 52 | |
ce8e922c NS |
53 | #ifdef XFS_BUF_LOCK_TRACKING |
54 | # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid) | |
55 | # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1) | |
56 | # define XB_GET_OWNER(bp) ((bp)->b_last_holder) | |
1da177e4 | 57 | #else |
ce8e922c NS |
58 | # define XB_SET_OWNER(bp) do { } while (0) |
59 | # define XB_CLEAR_OWNER(bp) do { } while (0) | |
60 | # define XB_GET_OWNER(bp) do { } while (0) | |
1da177e4 LT |
61 | #endif |
62 | ||
ce8e922c NS |
63 | #define xb_to_gfp(flags) \ |
64 | ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : \ | |
65 | ((flags) & XBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN) | |
1da177e4 | 66 | |
ce8e922c NS |
67 | #define xb_to_km(flags) \ |
68 | (((flags) & XBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP) | |
1da177e4 | 69 | |
ce8e922c NS |
70 | #define xfs_buf_allocate(flags) \ |
71 | kmem_zone_alloc(xfs_buf_zone, xb_to_km(flags)) | |
72 | #define xfs_buf_deallocate(bp) \ | |
73 | kmem_zone_free(xfs_buf_zone, (bp)); | |
1da177e4 | 74 | |
73c77e2c JB |
75 | static inline int |
76 | xfs_buf_is_vmapped( | |
77 | struct xfs_buf *bp) | |
78 | { | |
79 | /* | |
80 | * Return true if the buffer is vmapped. | |
81 | * | |
82 | * The XBF_MAPPED flag is set if the buffer should be mapped, but the | |
83 | * code is clever enough to know it doesn't have to map a single page, | |
84 | * so the check has to be both for XBF_MAPPED and bp->b_page_count > 1. | |
85 | */ | |
86 | return (bp->b_flags & XBF_MAPPED) && bp->b_page_count > 1; | |
87 | } | |
88 | ||
89 | static inline int | |
90 | xfs_buf_vmap_len( | |
91 | struct xfs_buf *bp) | |
92 | { | |
93 | return (bp->b_page_count * PAGE_SIZE) - bp->b_offset; | |
94 | } | |
95 | ||
1da177e4 | 96 | /* |
430cbeb8 DC |
97 | * xfs_buf_lru_add - add a buffer to the LRU. |
98 | * | |
99 | * The LRU takes a new reference to the buffer so that it will only be freed | |
100 | * once the shrinker takes the buffer off the LRU. | |
101 | */ | |
102 | STATIC void | |
103 | xfs_buf_lru_add( | |
104 | struct xfs_buf *bp) | |
105 | { | |
106 | struct xfs_buftarg *btp = bp->b_target; | |
107 | ||
108 | spin_lock(&btp->bt_lru_lock); | |
109 | if (list_empty(&bp->b_lru)) { | |
110 | atomic_inc(&bp->b_hold); | |
111 | list_add_tail(&bp->b_lru, &btp->bt_lru); | |
112 | btp->bt_lru_nr++; | |
113 | } | |
114 | spin_unlock(&btp->bt_lru_lock); | |
115 | } | |
116 | ||
117 | /* | |
118 | * xfs_buf_lru_del - remove a buffer from the LRU | |
119 | * | |
120 | * The unlocked check is safe here because it only occurs when there are not | |
121 | * b_lru_ref counts left on the inode under the pag->pag_buf_lock. it is there | |
122 | * to optimise the shrinker removing the buffer from the LRU and calling | |
123 | * xfs_buf_free(). i.e. it removes an unneccessary round trip on the | |
124 | * bt_lru_lock. | |
1da177e4 | 125 | */ |
430cbeb8 DC |
126 | STATIC void |
127 | xfs_buf_lru_del( | |
128 | struct xfs_buf *bp) | |
129 | { | |
130 | struct xfs_buftarg *btp = bp->b_target; | |
131 | ||
132 | if (list_empty(&bp->b_lru)) | |
133 | return; | |
134 | ||
135 | spin_lock(&btp->bt_lru_lock); | |
136 | if (!list_empty(&bp->b_lru)) { | |
137 | list_del_init(&bp->b_lru); | |
138 | btp->bt_lru_nr--; | |
139 | } | |
140 | spin_unlock(&btp->bt_lru_lock); | |
141 | } | |
142 | ||
143 | /* | |
144 | * When we mark a buffer stale, we remove the buffer from the LRU and clear the | |
145 | * b_lru_ref count so that the buffer is freed immediately when the buffer | |
146 | * reference count falls to zero. If the buffer is already on the LRU, we need | |
147 | * to remove the reference that LRU holds on the buffer. | |
148 | * | |
149 | * This prevents build-up of stale buffers on the LRU. | |
150 | */ | |
151 | void | |
152 | xfs_buf_stale( | |
153 | struct xfs_buf *bp) | |
154 | { | |
155 | bp->b_flags |= XBF_STALE; | |
156 | atomic_set(&(bp)->b_lru_ref, 0); | |
157 | if (!list_empty(&bp->b_lru)) { | |
158 | struct xfs_buftarg *btp = bp->b_target; | |
159 | ||
160 | spin_lock(&btp->bt_lru_lock); | |
161 | if (!list_empty(&bp->b_lru)) { | |
162 | list_del_init(&bp->b_lru); | |
163 | btp->bt_lru_nr--; | |
164 | atomic_dec(&bp->b_hold); | |
165 | } | |
166 | spin_unlock(&btp->bt_lru_lock); | |
167 | } | |
168 | ASSERT(atomic_read(&bp->b_hold) >= 1); | |
169 | } | |
1da177e4 LT |
170 | |
171 | STATIC void | |
ce8e922c NS |
172 | _xfs_buf_initialize( |
173 | xfs_buf_t *bp, | |
1da177e4 | 174 | xfs_buftarg_t *target, |
204ab25f | 175 | xfs_off_t range_base, |
1da177e4 | 176 | size_t range_length, |
ce8e922c | 177 | xfs_buf_flags_t flags) |
1da177e4 LT |
178 | { |
179 | /* | |
ce8e922c | 180 | * We don't want certain flags to appear in b_flags. |
1da177e4 | 181 | */ |
ce8e922c NS |
182 | flags &= ~(XBF_LOCK|XBF_MAPPED|XBF_DONT_BLOCK|XBF_READ_AHEAD); |
183 | ||
184 | memset(bp, 0, sizeof(xfs_buf_t)); | |
185 | atomic_set(&bp->b_hold, 1); | |
430cbeb8 | 186 | atomic_set(&bp->b_lru_ref, 1); |
b4dd330b | 187 | init_completion(&bp->b_iowait); |
430cbeb8 | 188 | INIT_LIST_HEAD(&bp->b_lru); |
ce8e922c | 189 | INIT_LIST_HEAD(&bp->b_list); |
74f75a0c | 190 | RB_CLEAR_NODE(&bp->b_rbnode); |
a731cd11 | 191 | sema_init(&bp->b_sema, 0); /* held, no waiters */ |
ce8e922c NS |
192 | XB_SET_OWNER(bp); |
193 | bp->b_target = target; | |
194 | bp->b_file_offset = range_base; | |
1da177e4 LT |
195 | /* |
196 | * Set buffer_length and count_desired to the same value initially. | |
197 | * I/O routines should use count_desired, which will be the same in | |
198 | * most cases but may be reset (e.g. XFS recovery). | |
199 | */ | |
ce8e922c NS |
200 | bp->b_buffer_length = bp->b_count_desired = range_length; |
201 | bp->b_flags = flags; | |
202 | bp->b_bn = XFS_BUF_DADDR_NULL; | |
203 | atomic_set(&bp->b_pin_count, 0); | |
204 | init_waitqueue_head(&bp->b_waiters); | |
205 | ||
206 | XFS_STATS_INC(xb_create); | |
0b1b213f CH |
207 | |
208 | trace_xfs_buf_init(bp, _RET_IP_); | |
1da177e4 LT |
209 | } |
210 | ||
211 | /* | |
ce8e922c NS |
212 | * Allocate a page array capable of holding a specified number |
213 | * of pages, and point the page buf at it. | |
1da177e4 LT |
214 | */ |
215 | STATIC int | |
ce8e922c NS |
216 | _xfs_buf_get_pages( |
217 | xfs_buf_t *bp, | |
1da177e4 | 218 | int page_count, |
ce8e922c | 219 | xfs_buf_flags_t flags) |
1da177e4 LT |
220 | { |
221 | /* Make sure that we have a page list */ | |
ce8e922c NS |
222 | if (bp->b_pages == NULL) { |
223 | bp->b_offset = xfs_buf_poff(bp->b_file_offset); | |
224 | bp->b_page_count = page_count; | |
225 | if (page_count <= XB_PAGES) { | |
226 | bp->b_pages = bp->b_page_array; | |
1da177e4 | 227 | } else { |
ce8e922c NS |
228 | bp->b_pages = kmem_alloc(sizeof(struct page *) * |
229 | page_count, xb_to_km(flags)); | |
230 | if (bp->b_pages == NULL) | |
1da177e4 LT |
231 | return -ENOMEM; |
232 | } | |
ce8e922c | 233 | memset(bp->b_pages, 0, sizeof(struct page *) * page_count); |
1da177e4 LT |
234 | } |
235 | return 0; | |
236 | } | |
237 | ||
238 | /* | |
ce8e922c | 239 | * Frees b_pages if it was allocated. |
1da177e4 LT |
240 | */ |
241 | STATIC void | |
ce8e922c | 242 | _xfs_buf_free_pages( |
1da177e4 LT |
243 | xfs_buf_t *bp) |
244 | { | |
ce8e922c | 245 | if (bp->b_pages != bp->b_page_array) { |
f0e2d93c | 246 | kmem_free(bp->b_pages); |
3fc98b1a | 247 | bp->b_pages = NULL; |
1da177e4 LT |
248 | } |
249 | } | |
250 | ||
251 | /* | |
252 | * Releases the specified buffer. | |
253 | * | |
254 | * The modification state of any associated pages is left unchanged. | |
ce8e922c | 255 | * The buffer most not be on any hash - use xfs_buf_rele instead for |
1da177e4 LT |
256 | * hashed and refcounted buffers |
257 | */ | |
258 | void | |
ce8e922c | 259 | xfs_buf_free( |
1da177e4 LT |
260 | xfs_buf_t *bp) |
261 | { | |
0b1b213f | 262 | trace_xfs_buf_free(bp, _RET_IP_); |
1da177e4 | 263 | |
430cbeb8 DC |
264 | ASSERT(list_empty(&bp->b_lru)); |
265 | ||
0e6e847f | 266 | if (bp->b_flags & _XBF_PAGES) { |
1da177e4 LT |
267 | uint i; |
268 | ||
73c77e2c | 269 | if (xfs_buf_is_vmapped(bp)) |
8a262e57 AE |
270 | vm_unmap_ram(bp->b_addr - bp->b_offset, |
271 | bp->b_page_count); | |
1da177e4 | 272 | |
948ecdb4 NS |
273 | for (i = 0; i < bp->b_page_count; i++) { |
274 | struct page *page = bp->b_pages[i]; | |
275 | ||
0e6e847f | 276 | __free_page(page); |
948ecdb4 | 277 | } |
0e6e847f DC |
278 | } else if (bp->b_flags & _XBF_KMEM) |
279 | kmem_free(bp->b_addr); | |
3fc98b1a | 280 | _xfs_buf_free_pages(bp); |
ce8e922c | 281 | xfs_buf_deallocate(bp); |
1da177e4 LT |
282 | } |
283 | ||
284 | /* | |
0e6e847f | 285 | * Allocates all the pages for buffer in question and builds it's page list. |
1da177e4 LT |
286 | */ |
287 | STATIC int | |
0e6e847f | 288 | xfs_buf_allocate_memory( |
1da177e4 LT |
289 | xfs_buf_t *bp, |
290 | uint flags) | |
291 | { | |
ce8e922c | 292 | size_t size = bp->b_count_desired; |
1da177e4 | 293 | size_t nbytes, offset; |
ce8e922c | 294 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 LT |
295 | unsigned short page_count, i; |
296 | pgoff_t first; | |
204ab25f | 297 | xfs_off_t end; |
1da177e4 LT |
298 | int error; |
299 | ||
0e6e847f DC |
300 | /* |
301 | * for buffers that are contained within a single page, just allocate | |
302 | * the memory from the heap - there's no need for the complexity of | |
303 | * page arrays to keep allocation down to order 0. | |
304 | */ | |
305 | if (bp->b_buffer_length < PAGE_SIZE) { | |
306 | bp->b_addr = kmem_alloc(bp->b_buffer_length, xb_to_km(flags)); | |
307 | if (!bp->b_addr) { | |
308 | /* low memory - use alloc_page loop instead */ | |
309 | goto use_alloc_page; | |
310 | } | |
311 | ||
312 | if (((unsigned long)(bp->b_addr + bp->b_buffer_length - 1) & | |
313 | PAGE_MASK) != | |
314 | ((unsigned long)bp->b_addr & PAGE_MASK)) { | |
315 | /* b_addr spans two pages - use alloc_page instead */ | |
316 | kmem_free(bp->b_addr); | |
317 | bp->b_addr = NULL; | |
318 | goto use_alloc_page; | |
319 | } | |
320 | bp->b_offset = offset_in_page(bp->b_addr); | |
321 | bp->b_pages = bp->b_page_array; | |
322 | bp->b_pages[0] = virt_to_page(bp->b_addr); | |
323 | bp->b_page_count = 1; | |
324 | bp->b_flags |= XBF_MAPPED | _XBF_KMEM; | |
325 | return 0; | |
326 | } | |
327 | ||
328 | use_alloc_page: | |
ce8e922c NS |
329 | end = bp->b_file_offset + bp->b_buffer_length; |
330 | page_count = xfs_buf_btoc(end) - xfs_buf_btoct(bp->b_file_offset); | |
ce8e922c | 331 | error = _xfs_buf_get_pages(bp, page_count, flags); |
1da177e4 LT |
332 | if (unlikely(error)) |
333 | return error; | |
1da177e4 | 334 | |
ce8e922c | 335 | offset = bp->b_offset; |
0e6e847f DC |
336 | first = bp->b_file_offset >> PAGE_SHIFT; |
337 | bp->b_flags |= _XBF_PAGES; | |
1da177e4 | 338 | |
ce8e922c | 339 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
340 | struct page *page; |
341 | uint retries = 0; | |
0e6e847f DC |
342 | retry: |
343 | page = alloc_page(gfp_mask); | |
1da177e4 | 344 | if (unlikely(page == NULL)) { |
ce8e922c NS |
345 | if (flags & XBF_READ_AHEAD) { |
346 | bp->b_page_count = i; | |
0e6e847f DC |
347 | error = ENOMEM; |
348 | goto out_free_pages; | |
1da177e4 LT |
349 | } |
350 | ||
351 | /* | |
352 | * This could deadlock. | |
353 | * | |
354 | * But until all the XFS lowlevel code is revamped to | |
355 | * handle buffer allocation failures we can't do much. | |
356 | */ | |
357 | if (!(++retries % 100)) | |
4f10700a DC |
358 | xfs_err(NULL, |
359 | "possible memory allocation deadlock in %s (mode:0x%x)", | |
34a622b2 | 360 | __func__, gfp_mask); |
1da177e4 | 361 | |
ce8e922c | 362 | XFS_STATS_INC(xb_page_retries); |
8aa7e847 | 363 | congestion_wait(BLK_RW_ASYNC, HZ/50); |
1da177e4 LT |
364 | goto retry; |
365 | } | |
366 | ||
ce8e922c | 367 | XFS_STATS_INC(xb_page_found); |
1da177e4 | 368 | |
0e6e847f | 369 | nbytes = min_t(size_t, size, PAGE_SIZE - offset); |
1da177e4 | 370 | size -= nbytes; |
ce8e922c | 371 | bp->b_pages[i] = page; |
1da177e4 LT |
372 | offset = 0; |
373 | } | |
0e6e847f | 374 | return 0; |
1da177e4 | 375 | |
0e6e847f DC |
376 | out_free_pages: |
377 | for (i = 0; i < bp->b_page_count; i++) | |
378 | __free_page(bp->b_pages[i]); | |
1da177e4 LT |
379 | return error; |
380 | } | |
381 | ||
382 | /* | |
383 | * Map buffer into kernel address-space if nessecary. | |
384 | */ | |
385 | STATIC int | |
ce8e922c | 386 | _xfs_buf_map_pages( |
1da177e4 LT |
387 | xfs_buf_t *bp, |
388 | uint flags) | |
389 | { | |
0e6e847f | 390 | ASSERT(bp->b_flags & _XBF_PAGES); |
ce8e922c | 391 | if (bp->b_page_count == 1) { |
0e6e847f | 392 | /* A single page buffer is always mappable */ |
ce8e922c NS |
393 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; |
394 | bp->b_flags |= XBF_MAPPED; | |
395 | } else if (flags & XBF_MAPPED) { | |
a19fb380 DC |
396 | int retried = 0; |
397 | ||
398 | do { | |
399 | bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, | |
400 | -1, PAGE_KERNEL); | |
401 | if (bp->b_addr) | |
402 | break; | |
403 | vm_unmap_aliases(); | |
404 | } while (retried++ <= 1); | |
405 | ||
406 | if (!bp->b_addr) | |
1da177e4 | 407 | return -ENOMEM; |
ce8e922c NS |
408 | bp->b_addr += bp->b_offset; |
409 | bp->b_flags |= XBF_MAPPED; | |
1da177e4 LT |
410 | } |
411 | ||
412 | return 0; | |
413 | } | |
414 | ||
415 | /* | |
416 | * Finding and Reading Buffers | |
417 | */ | |
418 | ||
419 | /* | |
ce8e922c | 420 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 LT |
421 | * a given range of an inode. The buffer is returned |
422 | * locked. If other overlapping buffers exist, they are | |
423 | * released before the new buffer is created and locked, | |
424 | * which may imply that this call will block until those buffers | |
425 | * are unlocked. No I/O is implied by this call. | |
426 | */ | |
427 | xfs_buf_t * | |
ce8e922c | 428 | _xfs_buf_find( |
1da177e4 | 429 | xfs_buftarg_t *btp, /* block device target */ |
204ab25f | 430 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 431 | size_t isize, /* length of range */ |
ce8e922c NS |
432 | xfs_buf_flags_t flags, |
433 | xfs_buf_t *new_bp) | |
1da177e4 | 434 | { |
204ab25f | 435 | xfs_off_t range_base; |
1da177e4 | 436 | size_t range_length; |
74f75a0c DC |
437 | struct xfs_perag *pag; |
438 | struct rb_node **rbp; | |
439 | struct rb_node *parent; | |
440 | xfs_buf_t *bp; | |
1da177e4 LT |
441 | |
442 | range_base = (ioff << BBSHIFT); | |
443 | range_length = (isize << BBSHIFT); | |
444 | ||
445 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
ce8e922c | 446 | ASSERT(!(range_length < (1 << btp->bt_sshift))); |
204ab25f | 447 | ASSERT(!(range_base & (xfs_off_t)btp->bt_smask)); |
1da177e4 | 448 | |
74f75a0c DC |
449 | /* get tree root */ |
450 | pag = xfs_perag_get(btp->bt_mount, | |
451 | xfs_daddr_to_agno(btp->bt_mount, ioff)); | |
452 | ||
453 | /* walk tree */ | |
454 | spin_lock(&pag->pag_buf_lock); | |
455 | rbp = &pag->pag_buf_tree.rb_node; | |
456 | parent = NULL; | |
457 | bp = NULL; | |
458 | while (*rbp) { | |
459 | parent = *rbp; | |
460 | bp = rb_entry(parent, struct xfs_buf, b_rbnode); | |
461 | ||
462 | if (range_base < bp->b_file_offset) | |
463 | rbp = &(*rbp)->rb_left; | |
464 | else if (range_base > bp->b_file_offset) | |
465 | rbp = &(*rbp)->rb_right; | |
466 | else { | |
467 | /* | |
468 | * found a block offset match. If the range doesn't | |
469 | * match, the only way this is allowed is if the buffer | |
470 | * in the cache is stale and the transaction that made | |
471 | * it stale has not yet committed. i.e. we are | |
472 | * reallocating a busy extent. Skip this buffer and | |
473 | * continue searching to the right for an exact match. | |
474 | */ | |
475 | if (bp->b_buffer_length != range_length) { | |
476 | ASSERT(bp->b_flags & XBF_STALE); | |
477 | rbp = &(*rbp)->rb_right; | |
478 | continue; | |
479 | } | |
ce8e922c | 480 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
481 | goto found; |
482 | } | |
483 | } | |
484 | ||
485 | /* No match found */ | |
ce8e922c NS |
486 | if (new_bp) { |
487 | _xfs_buf_initialize(new_bp, btp, range_base, | |
1da177e4 | 488 | range_length, flags); |
74f75a0c DC |
489 | rb_link_node(&new_bp->b_rbnode, parent, rbp); |
490 | rb_insert_color(&new_bp->b_rbnode, &pag->pag_buf_tree); | |
491 | /* the buffer keeps the perag reference until it is freed */ | |
492 | new_bp->b_pag = pag; | |
493 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 494 | } else { |
ce8e922c | 495 | XFS_STATS_INC(xb_miss_locked); |
74f75a0c DC |
496 | spin_unlock(&pag->pag_buf_lock); |
497 | xfs_perag_put(pag); | |
1da177e4 | 498 | } |
ce8e922c | 499 | return new_bp; |
1da177e4 LT |
500 | |
501 | found: | |
74f75a0c DC |
502 | spin_unlock(&pag->pag_buf_lock); |
503 | xfs_perag_put(pag); | |
1da177e4 | 504 | |
90810b9e DC |
505 | if (xfs_buf_cond_lock(bp)) { |
506 | /* failed, so wait for the lock if requested. */ | |
ce8e922c | 507 | if (!(flags & XBF_TRYLOCK)) { |
ce8e922c NS |
508 | xfs_buf_lock(bp); |
509 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 | 510 | } else { |
ce8e922c NS |
511 | xfs_buf_rele(bp); |
512 | XFS_STATS_INC(xb_busy_locked); | |
513 | return NULL; | |
1da177e4 | 514 | } |
1da177e4 LT |
515 | } |
516 | ||
0e6e847f DC |
517 | /* |
518 | * if the buffer is stale, clear all the external state associated with | |
519 | * it. We need to keep flags such as how we allocated the buffer memory | |
520 | * intact here. | |
521 | */ | |
ce8e922c NS |
522 | if (bp->b_flags & XBF_STALE) { |
523 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
0e6e847f | 524 | bp->b_flags &= XBF_MAPPED | _XBF_KMEM | _XBF_PAGES; |
2f926587 | 525 | } |
0b1b213f CH |
526 | |
527 | trace_xfs_buf_find(bp, flags, _RET_IP_); | |
ce8e922c NS |
528 | XFS_STATS_INC(xb_get_locked); |
529 | return bp; | |
1da177e4 LT |
530 | } |
531 | ||
532 | /* | |
ce8e922c | 533 | * Assembles a buffer covering the specified range. |
1da177e4 LT |
534 | * Storage in memory for all portions of the buffer will be allocated, |
535 | * although backing storage may not be. | |
536 | */ | |
537 | xfs_buf_t * | |
6ad112bf | 538 | xfs_buf_get( |
1da177e4 | 539 | xfs_buftarg_t *target,/* target for buffer */ |
204ab25f | 540 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 541 | size_t isize, /* length of range */ |
ce8e922c | 542 | xfs_buf_flags_t flags) |
1da177e4 | 543 | { |
ce8e922c | 544 | xfs_buf_t *bp, *new_bp; |
0e6e847f | 545 | int error = 0; |
1da177e4 | 546 | |
ce8e922c NS |
547 | new_bp = xfs_buf_allocate(flags); |
548 | if (unlikely(!new_bp)) | |
1da177e4 LT |
549 | return NULL; |
550 | ||
ce8e922c NS |
551 | bp = _xfs_buf_find(target, ioff, isize, flags, new_bp); |
552 | if (bp == new_bp) { | |
0e6e847f | 553 | error = xfs_buf_allocate_memory(bp, flags); |
1da177e4 LT |
554 | if (error) |
555 | goto no_buffer; | |
556 | } else { | |
ce8e922c NS |
557 | xfs_buf_deallocate(new_bp); |
558 | if (unlikely(bp == NULL)) | |
1da177e4 LT |
559 | return NULL; |
560 | } | |
561 | ||
ce8e922c NS |
562 | if (!(bp->b_flags & XBF_MAPPED)) { |
563 | error = _xfs_buf_map_pages(bp, flags); | |
1da177e4 | 564 | if (unlikely(error)) { |
4f10700a DC |
565 | xfs_warn(target->bt_mount, |
566 | "%s: failed to map pages\n", __func__); | |
1da177e4 LT |
567 | goto no_buffer; |
568 | } | |
569 | } | |
570 | ||
ce8e922c | 571 | XFS_STATS_INC(xb_get); |
1da177e4 LT |
572 | |
573 | /* | |
574 | * Always fill in the block number now, the mapped cases can do | |
575 | * their own overlay of this later. | |
576 | */ | |
ce8e922c NS |
577 | bp->b_bn = ioff; |
578 | bp->b_count_desired = bp->b_buffer_length; | |
1da177e4 | 579 | |
0b1b213f | 580 | trace_xfs_buf_get(bp, flags, _RET_IP_); |
ce8e922c | 581 | return bp; |
1da177e4 LT |
582 | |
583 | no_buffer: | |
ce8e922c NS |
584 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
585 | xfs_buf_unlock(bp); | |
586 | xfs_buf_rele(bp); | |
1da177e4 LT |
587 | return NULL; |
588 | } | |
589 | ||
5d765b97 CH |
590 | STATIC int |
591 | _xfs_buf_read( | |
592 | xfs_buf_t *bp, | |
593 | xfs_buf_flags_t flags) | |
594 | { | |
595 | int status; | |
596 | ||
5d765b97 CH |
597 | ASSERT(!(flags & (XBF_DELWRI|XBF_WRITE))); |
598 | ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL); | |
599 | ||
600 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_DELWRI | \ | |
601 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
602 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | \ | |
603 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
604 | ||
605 | status = xfs_buf_iorequest(bp); | |
ec53d1db DC |
606 | if (status || XFS_BUF_ISERROR(bp) || (flags & XBF_ASYNC)) |
607 | return status; | |
608 | return xfs_buf_iowait(bp); | |
5d765b97 CH |
609 | } |
610 | ||
1da177e4 | 611 | xfs_buf_t * |
6ad112bf | 612 | xfs_buf_read( |
1da177e4 | 613 | xfs_buftarg_t *target, |
204ab25f | 614 | xfs_off_t ioff, |
1da177e4 | 615 | size_t isize, |
ce8e922c | 616 | xfs_buf_flags_t flags) |
1da177e4 | 617 | { |
ce8e922c NS |
618 | xfs_buf_t *bp; |
619 | ||
620 | flags |= XBF_READ; | |
621 | ||
6ad112bf | 622 | bp = xfs_buf_get(target, ioff, isize, flags); |
ce8e922c | 623 | if (bp) { |
0b1b213f CH |
624 | trace_xfs_buf_read(bp, flags, _RET_IP_); |
625 | ||
ce8e922c | 626 | if (!XFS_BUF_ISDONE(bp)) { |
ce8e922c | 627 | XFS_STATS_INC(xb_get_read); |
5d765b97 | 628 | _xfs_buf_read(bp, flags); |
ce8e922c | 629 | } else if (flags & XBF_ASYNC) { |
1da177e4 LT |
630 | /* |
631 | * Read ahead call which is already satisfied, | |
632 | * drop the buffer | |
633 | */ | |
634 | goto no_buffer; | |
635 | } else { | |
1da177e4 | 636 | /* We do not want read in the flags */ |
ce8e922c | 637 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
638 | } |
639 | } | |
640 | ||
ce8e922c | 641 | return bp; |
1da177e4 LT |
642 | |
643 | no_buffer: | |
ce8e922c NS |
644 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
645 | xfs_buf_unlock(bp); | |
646 | xfs_buf_rele(bp); | |
1da177e4 LT |
647 | return NULL; |
648 | } | |
649 | ||
1da177e4 | 650 | /* |
ce8e922c NS |
651 | * If we are not low on memory then do the readahead in a deadlock |
652 | * safe manner. | |
1da177e4 LT |
653 | */ |
654 | void | |
ce8e922c | 655 | xfs_buf_readahead( |
1da177e4 | 656 | xfs_buftarg_t *target, |
204ab25f | 657 | xfs_off_t ioff, |
1a1a3e97 | 658 | size_t isize) |
1da177e4 LT |
659 | { |
660 | struct backing_dev_info *bdi; | |
661 | ||
0e6e847f | 662 | if (bdi_read_congested(target->bt_bdi)) |
1da177e4 LT |
663 | return; |
664 | ||
1a1a3e97 CH |
665 | xfs_buf_read(target, ioff, isize, |
666 | XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD|XBF_DONT_BLOCK); | |
1da177e4 LT |
667 | } |
668 | ||
5adc94c2 DC |
669 | /* |
670 | * Read an uncached buffer from disk. Allocates and returns a locked | |
671 | * buffer containing the disk contents or nothing. | |
672 | */ | |
673 | struct xfs_buf * | |
674 | xfs_buf_read_uncached( | |
675 | struct xfs_mount *mp, | |
676 | struct xfs_buftarg *target, | |
677 | xfs_daddr_t daddr, | |
678 | size_t length, | |
679 | int flags) | |
680 | { | |
681 | xfs_buf_t *bp; | |
682 | int error; | |
683 | ||
684 | bp = xfs_buf_get_uncached(target, length, flags); | |
685 | if (!bp) | |
686 | return NULL; | |
687 | ||
688 | /* set up the buffer for a read IO */ | |
689 | xfs_buf_lock(bp); | |
690 | XFS_BUF_SET_ADDR(bp, daddr); | |
691 | XFS_BUF_READ(bp); | |
692 | XFS_BUF_BUSY(bp); | |
693 | ||
694 | xfsbdstrat(mp, bp); | |
1a1a3e97 | 695 | error = xfs_buf_iowait(bp); |
5adc94c2 DC |
696 | if (error || bp->b_error) { |
697 | xfs_buf_relse(bp); | |
698 | return NULL; | |
699 | } | |
700 | return bp; | |
1da177e4 LT |
701 | } |
702 | ||
703 | xfs_buf_t * | |
ce8e922c | 704 | xfs_buf_get_empty( |
1da177e4 LT |
705 | size_t len, |
706 | xfs_buftarg_t *target) | |
707 | { | |
ce8e922c | 708 | xfs_buf_t *bp; |
1da177e4 | 709 | |
ce8e922c NS |
710 | bp = xfs_buf_allocate(0); |
711 | if (bp) | |
712 | _xfs_buf_initialize(bp, target, 0, len, 0); | |
713 | return bp; | |
1da177e4 LT |
714 | } |
715 | ||
716 | static inline struct page * | |
717 | mem_to_page( | |
718 | void *addr) | |
719 | { | |
9e2779fa | 720 | if ((!is_vmalloc_addr(addr))) { |
1da177e4 LT |
721 | return virt_to_page(addr); |
722 | } else { | |
723 | return vmalloc_to_page(addr); | |
724 | } | |
725 | } | |
726 | ||
727 | int | |
ce8e922c NS |
728 | xfs_buf_associate_memory( |
729 | xfs_buf_t *bp, | |
1da177e4 LT |
730 | void *mem, |
731 | size_t len) | |
732 | { | |
733 | int rval; | |
734 | int i = 0; | |
d1afb678 LM |
735 | unsigned long pageaddr; |
736 | unsigned long offset; | |
737 | size_t buflen; | |
1da177e4 LT |
738 | int page_count; |
739 | ||
0e6e847f | 740 | pageaddr = (unsigned long)mem & PAGE_MASK; |
d1afb678 | 741 | offset = (unsigned long)mem - pageaddr; |
0e6e847f DC |
742 | buflen = PAGE_ALIGN(len + offset); |
743 | page_count = buflen >> PAGE_SHIFT; | |
1da177e4 LT |
744 | |
745 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
746 | if (bp->b_pages) |
747 | _xfs_buf_free_pages(bp); | |
1da177e4 | 748 | |
ce8e922c NS |
749 | bp->b_pages = NULL; |
750 | bp->b_addr = mem; | |
1da177e4 | 751 | |
36fae17a | 752 | rval = _xfs_buf_get_pages(bp, page_count, XBF_DONT_BLOCK); |
1da177e4 LT |
753 | if (rval) |
754 | return rval; | |
755 | ||
ce8e922c | 756 | bp->b_offset = offset; |
d1afb678 LM |
757 | |
758 | for (i = 0; i < bp->b_page_count; i++) { | |
759 | bp->b_pages[i] = mem_to_page((void *)pageaddr); | |
0e6e847f | 760 | pageaddr += PAGE_SIZE; |
1da177e4 | 761 | } |
1da177e4 | 762 | |
d1afb678 LM |
763 | bp->b_count_desired = len; |
764 | bp->b_buffer_length = buflen; | |
ce8e922c | 765 | bp->b_flags |= XBF_MAPPED; |
1da177e4 LT |
766 | |
767 | return 0; | |
768 | } | |
769 | ||
770 | xfs_buf_t * | |
686865f7 DC |
771 | xfs_buf_get_uncached( |
772 | struct xfs_buftarg *target, | |
1da177e4 | 773 | size_t len, |
686865f7 | 774 | int flags) |
1da177e4 | 775 | { |
1fa40b01 CH |
776 | unsigned long page_count = PAGE_ALIGN(len) >> PAGE_SHIFT; |
777 | int error, i; | |
1da177e4 | 778 | xfs_buf_t *bp; |
1da177e4 | 779 | |
ce8e922c | 780 | bp = xfs_buf_allocate(0); |
1da177e4 LT |
781 | if (unlikely(bp == NULL)) |
782 | goto fail; | |
ce8e922c | 783 | _xfs_buf_initialize(bp, target, 0, len, 0); |
1da177e4 | 784 | |
1fa40b01 CH |
785 | error = _xfs_buf_get_pages(bp, page_count, 0); |
786 | if (error) | |
1da177e4 LT |
787 | goto fail_free_buf; |
788 | ||
1fa40b01 | 789 | for (i = 0; i < page_count; i++) { |
686865f7 | 790 | bp->b_pages[i] = alloc_page(xb_to_gfp(flags)); |
1fa40b01 CH |
791 | if (!bp->b_pages[i]) |
792 | goto fail_free_mem; | |
1da177e4 | 793 | } |
1fa40b01 | 794 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 795 | |
1fa40b01 CH |
796 | error = _xfs_buf_map_pages(bp, XBF_MAPPED); |
797 | if (unlikely(error)) { | |
4f10700a DC |
798 | xfs_warn(target->bt_mount, |
799 | "%s: failed to map pages\n", __func__); | |
1da177e4 | 800 | goto fail_free_mem; |
1fa40b01 | 801 | } |
1da177e4 | 802 | |
ce8e922c | 803 | xfs_buf_unlock(bp); |
1da177e4 | 804 | |
686865f7 | 805 | trace_xfs_buf_get_uncached(bp, _RET_IP_); |
1da177e4 | 806 | return bp; |
1fa40b01 | 807 | |
1da177e4 | 808 | fail_free_mem: |
1fa40b01 CH |
809 | while (--i >= 0) |
810 | __free_page(bp->b_pages[i]); | |
ca165b88 | 811 | _xfs_buf_free_pages(bp); |
1da177e4 | 812 | fail_free_buf: |
ca165b88 | 813 | xfs_buf_deallocate(bp); |
1da177e4 LT |
814 | fail: |
815 | return NULL; | |
816 | } | |
817 | ||
818 | /* | |
1da177e4 LT |
819 | * Increment reference count on buffer, to hold the buffer concurrently |
820 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
821 | * Must hold the buffer already to call this function. |
822 | */ | |
823 | void | |
ce8e922c NS |
824 | xfs_buf_hold( |
825 | xfs_buf_t *bp) | |
1da177e4 | 826 | { |
0b1b213f | 827 | trace_xfs_buf_hold(bp, _RET_IP_); |
ce8e922c | 828 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
829 | } |
830 | ||
831 | /* | |
ce8e922c NS |
832 | * Releases a hold on the specified buffer. If the |
833 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
834 | */ |
835 | void | |
ce8e922c NS |
836 | xfs_buf_rele( |
837 | xfs_buf_t *bp) | |
1da177e4 | 838 | { |
74f75a0c | 839 | struct xfs_perag *pag = bp->b_pag; |
1da177e4 | 840 | |
0b1b213f | 841 | trace_xfs_buf_rele(bp, _RET_IP_); |
1da177e4 | 842 | |
74f75a0c | 843 | if (!pag) { |
430cbeb8 | 844 | ASSERT(list_empty(&bp->b_lru)); |
74f75a0c | 845 | ASSERT(RB_EMPTY_NODE(&bp->b_rbnode)); |
fad3aa1e NS |
846 | if (atomic_dec_and_test(&bp->b_hold)) |
847 | xfs_buf_free(bp); | |
848 | return; | |
849 | } | |
850 | ||
74f75a0c | 851 | ASSERT(!RB_EMPTY_NODE(&bp->b_rbnode)); |
430cbeb8 | 852 | |
3790689f | 853 | ASSERT(atomic_read(&bp->b_hold) > 0); |
74f75a0c | 854 | if (atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock)) { |
bfc60177 | 855 | if (!(bp->b_flags & XBF_STALE) && |
430cbeb8 DC |
856 | atomic_read(&bp->b_lru_ref)) { |
857 | xfs_buf_lru_add(bp); | |
858 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 859 | } else { |
430cbeb8 | 860 | xfs_buf_lru_del(bp); |
ce8e922c | 861 | ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q))); |
74f75a0c DC |
862 | rb_erase(&bp->b_rbnode, &pag->pag_buf_tree); |
863 | spin_unlock(&pag->pag_buf_lock); | |
864 | xfs_perag_put(pag); | |
ce8e922c | 865 | xfs_buf_free(bp); |
1da177e4 LT |
866 | } |
867 | } | |
868 | } | |
869 | ||
870 | ||
871 | /* | |
0e6e847f | 872 | * Lock a buffer object, if it is not already locked. |
90810b9e DC |
873 | * |
874 | * If we come across a stale, pinned, locked buffer, we know that we are | |
875 | * being asked to lock a buffer that has been reallocated. Because it is | |
876 | * pinned, we know that the log has not been pushed to disk and hence it | |
877 | * will still be locked. Rather than continuing to have trylock attempts | |
878 | * fail until someone else pushes the log, push it ourselves before | |
879 | * returning. This means that the xfsaild will not get stuck trying | |
880 | * to push on stale inode buffers. | |
1da177e4 LT |
881 | */ |
882 | int | |
ce8e922c NS |
883 | xfs_buf_cond_lock( |
884 | xfs_buf_t *bp) | |
1da177e4 LT |
885 | { |
886 | int locked; | |
887 | ||
ce8e922c | 888 | locked = down_trylock(&bp->b_sema) == 0; |
0b1b213f | 889 | if (locked) |
ce8e922c | 890 | XB_SET_OWNER(bp); |
90810b9e DC |
891 | else if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
892 | xfs_log_force(bp->b_target->bt_mount, 0); | |
0b1b213f CH |
893 | |
894 | trace_xfs_buf_cond_lock(bp, _RET_IP_); | |
ce8e922c | 895 | return locked ? 0 : -EBUSY; |
1da177e4 LT |
896 | } |
897 | ||
1da177e4 | 898 | int |
ce8e922c NS |
899 | xfs_buf_lock_value( |
900 | xfs_buf_t *bp) | |
1da177e4 | 901 | { |
adaa693b | 902 | return bp->b_sema.count; |
1da177e4 | 903 | } |
1da177e4 LT |
904 | |
905 | /* | |
0e6e847f | 906 | * Lock a buffer object. |
ed3b4d6c DC |
907 | * |
908 | * If we come across a stale, pinned, locked buffer, we know that we | |
909 | * are being asked to lock a buffer that has been reallocated. Because | |
910 | * it is pinned, we know that the log has not been pushed to disk and | |
911 | * hence it will still be locked. Rather than sleeping until someone | |
912 | * else pushes the log, push it ourselves before trying to get the lock. | |
1da177e4 | 913 | */ |
ce8e922c NS |
914 | void |
915 | xfs_buf_lock( | |
916 | xfs_buf_t *bp) | |
1da177e4 | 917 | { |
0b1b213f CH |
918 | trace_xfs_buf_lock(bp, _RET_IP_); |
919 | ||
ed3b4d6c | 920 | if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
ebad861b | 921 | xfs_log_force(bp->b_target->bt_mount, 0); |
ce8e922c | 922 | if (atomic_read(&bp->b_io_remaining)) |
0e6e847f | 923 | blk_run_backing_dev(bp->b_target->bt_bdi, NULL); |
ce8e922c NS |
924 | down(&bp->b_sema); |
925 | XB_SET_OWNER(bp); | |
0b1b213f CH |
926 | |
927 | trace_xfs_buf_lock_done(bp, _RET_IP_); | |
1da177e4 LT |
928 | } |
929 | ||
930 | /* | |
ce8e922c | 931 | * Releases the lock on the buffer object. |
2f926587 | 932 | * If the buffer is marked delwri but is not queued, do so before we |
ce8e922c | 933 | * unlock the buffer as we need to set flags correctly. We also need to |
2f926587 DC |
934 | * take a reference for the delwri queue because the unlocker is going to |
935 | * drop their's and they don't know we just queued it. | |
1da177e4 LT |
936 | */ |
937 | void | |
ce8e922c NS |
938 | xfs_buf_unlock( |
939 | xfs_buf_t *bp) | |
1da177e4 | 940 | { |
ce8e922c NS |
941 | if ((bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)) == XBF_DELWRI) { |
942 | atomic_inc(&bp->b_hold); | |
943 | bp->b_flags |= XBF_ASYNC; | |
944 | xfs_buf_delwri_queue(bp, 0); | |
2f926587 DC |
945 | } |
946 | ||
ce8e922c NS |
947 | XB_CLEAR_OWNER(bp); |
948 | up(&bp->b_sema); | |
0b1b213f CH |
949 | |
950 | trace_xfs_buf_unlock(bp, _RET_IP_); | |
1da177e4 LT |
951 | } |
952 | ||
ce8e922c NS |
953 | STATIC void |
954 | xfs_buf_wait_unpin( | |
955 | xfs_buf_t *bp) | |
1da177e4 LT |
956 | { |
957 | DECLARE_WAITQUEUE (wait, current); | |
958 | ||
ce8e922c | 959 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
960 | return; |
961 | ||
ce8e922c | 962 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
963 | for (;;) { |
964 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 965 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 966 | break; |
ce8e922c | 967 | if (atomic_read(&bp->b_io_remaining)) |
0e6e847f | 968 | blk_run_backing_dev(bp->b_target->bt_bdi, NULL); |
1da177e4 LT |
969 | schedule(); |
970 | } | |
ce8e922c | 971 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
972 | set_current_state(TASK_RUNNING); |
973 | } | |
974 | ||
975 | /* | |
976 | * Buffer Utility Routines | |
977 | */ | |
978 | ||
1da177e4 | 979 | STATIC void |
ce8e922c | 980 | xfs_buf_iodone_work( |
c4028958 | 981 | struct work_struct *work) |
1da177e4 | 982 | { |
c4028958 DH |
983 | xfs_buf_t *bp = |
984 | container_of(work, xfs_buf_t, b_iodone_work); | |
1da177e4 | 985 | |
80f6c29d | 986 | if (bp->b_iodone) |
ce8e922c NS |
987 | (*(bp->b_iodone))(bp); |
988 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 LT |
989 | xfs_buf_relse(bp); |
990 | } | |
991 | ||
992 | void | |
ce8e922c NS |
993 | xfs_buf_ioend( |
994 | xfs_buf_t *bp, | |
1da177e4 LT |
995 | int schedule) |
996 | { | |
0b1b213f CH |
997 | trace_xfs_buf_iodone(bp, _RET_IP_); |
998 | ||
77be55a5 | 999 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); |
ce8e922c NS |
1000 | if (bp->b_error == 0) |
1001 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1002 | |
ce8e922c | 1003 | if ((bp->b_iodone) || (bp->b_flags & XBF_ASYNC)) { |
1da177e4 | 1004 | if (schedule) { |
c4028958 | 1005 | INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work); |
ce8e922c | 1006 | queue_work(xfslogd_workqueue, &bp->b_iodone_work); |
1da177e4 | 1007 | } else { |
c4028958 | 1008 | xfs_buf_iodone_work(&bp->b_iodone_work); |
1da177e4 LT |
1009 | } |
1010 | } else { | |
b4dd330b | 1011 | complete(&bp->b_iowait); |
1da177e4 LT |
1012 | } |
1013 | } | |
1014 | ||
1da177e4 | 1015 | void |
ce8e922c NS |
1016 | xfs_buf_ioerror( |
1017 | xfs_buf_t *bp, | |
1018 | int error) | |
1da177e4 LT |
1019 | { |
1020 | ASSERT(error >= 0 && error <= 0xffff); | |
ce8e922c | 1021 | bp->b_error = (unsigned short)error; |
0b1b213f | 1022 | trace_xfs_buf_ioerror(bp, error, _RET_IP_); |
1da177e4 LT |
1023 | } |
1024 | ||
1da177e4 | 1025 | int |
64e0bc7d CH |
1026 | xfs_bwrite( |
1027 | struct xfs_mount *mp, | |
5d765b97 | 1028 | struct xfs_buf *bp) |
1da177e4 | 1029 | { |
8c38366f | 1030 | int error; |
1da177e4 | 1031 | |
64e0bc7d | 1032 | bp->b_flags |= XBF_WRITE; |
8c38366f | 1033 | bp->b_flags &= ~(XBF_ASYNC | XBF_READ); |
1da177e4 | 1034 | |
5d765b97 | 1035 | xfs_buf_delwri_dequeue(bp); |
939d723b | 1036 | xfs_bdstrat_cb(bp); |
1da177e4 | 1037 | |
8c38366f CH |
1038 | error = xfs_buf_iowait(bp); |
1039 | if (error) | |
1040 | xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR); | |
1041 | xfs_buf_relse(bp); | |
64e0bc7d | 1042 | return error; |
5d765b97 | 1043 | } |
1da177e4 | 1044 | |
5d765b97 CH |
1045 | void |
1046 | xfs_bdwrite( | |
1047 | void *mp, | |
1048 | struct xfs_buf *bp) | |
1049 | { | |
0b1b213f | 1050 | trace_xfs_buf_bdwrite(bp, _RET_IP_); |
1da177e4 | 1051 | |
5d765b97 CH |
1052 | bp->b_flags &= ~XBF_READ; |
1053 | bp->b_flags |= (XBF_DELWRI | XBF_ASYNC); | |
1054 | ||
1055 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1056 | } |
1057 | ||
4e23471a CH |
1058 | /* |
1059 | * Called when we want to stop a buffer from getting written or read. | |
1a1a3e97 | 1060 | * We attach the EIO error, muck with its flags, and call xfs_buf_ioend |
4e23471a CH |
1061 | * so that the proper iodone callbacks get called. |
1062 | */ | |
1063 | STATIC int | |
1064 | xfs_bioerror( | |
1065 | xfs_buf_t *bp) | |
1066 | { | |
1067 | #ifdef XFSERRORDEBUG | |
1068 | ASSERT(XFS_BUF_ISREAD(bp) || bp->b_iodone); | |
1069 | #endif | |
1070 | ||
1071 | /* | |
1072 | * No need to wait until the buffer is unpinned, we aren't flushing it. | |
1073 | */ | |
1074 | XFS_BUF_ERROR(bp, EIO); | |
1075 | ||
1076 | /* | |
1a1a3e97 | 1077 | * We're calling xfs_buf_ioend, so delete XBF_DONE flag. |
4e23471a CH |
1078 | */ |
1079 | XFS_BUF_UNREAD(bp); | |
1080 | XFS_BUF_UNDELAYWRITE(bp); | |
1081 | XFS_BUF_UNDONE(bp); | |
1082 | XFS_BUF_STALE(bp); | |
1083 | ||
1a1a3e97 | 1084 | xfs_buf_ioend(bp, 0); |
4e23471a CH |
1085 | |
1086 | return EIO; | |
1087 | } | |
1088 | ||
1089 | /* | |
1090 | * Same as xfs_bioerror, except that we are releasing the buffer | |
1a1a3e97 | 1091 | * here ourselves, and avoiding the xfs_buf_ioend call. |
4e23471a CH |
1092 | * This is meant for userdata errors; metadata bufs come with |
1093 | * iodone functions attached, so that we can track down errors. | |
1094 | */ | |
1095 | STATIC int | |
1096 | xfs_bioerror_relse( | |
1097 | struct xfs_buf *bp) | |
1098 | { | |
1099 | int64_t fl = XFS_BUF_BFLAGS(bp); | |
1100 | /* | |
1101 | * No need to wait until the buffer is unpinned. | |
1102 | * We aren't flushing it. | |
1103 | * | |
1104 | * chunkhold expects B_DONE to be set, whether | |
1105 | * we actually finish the I/O or not. We don't want to | |
1106 | * change that interface. | |
1107 | */ | |
1108 | XFS_BUF_UNREAD(bp); | |
1109 | XFS_BUF_UNDELAYWRITE(bp); | |
1110 | XFS_BUF_DONE(bp); | |
1111 | XFS_BUF_STALE(bp); | |
1112 | XFS_BUF_CLR_IODONE_FUNC(bp); | |
0cadda1c | 1113 | if (!(fl & XBF_ASYNC)) { |
4e23471a CH |
1114 | /* |
1115 | * Mark b_error and B_ERROR _both_. | |
1116 | * Lot's of chunkcache code assumes that. | |
1117 | * There's no reason to mark error for | |
1118 | * ASYNC buffers. | |
1119 | */ | |
1120 | XFS_BUF_ERROR(bp, EIO); | |
1121 | XFS_BUF_FINISH_IOWAIT(bp); | |
1122 | } else { | |
1123 | xfs_buf_relse(bp); | |
1124 | } | |
1125 | ||
1126 | return EIO; | |
1127 | } | |
1128 | ||
1129 | ||
1130 | /* | |
1131 | * All xfs metadata buffers except log state machine buffers | |
1132 | * get this attached as their b_bdstrat callback function. | |
1133 | * This is so that we can catch a buffer | |
1134 | * after prematurely unpinning it to forcibly shutdown the filesystem. | |
1135 | */ | |
1136 | int | |
1137 | xfs_bdstrat_cb( | |
1138 | struct xfs_buf *bp) | |
1139 | { | |
ebad861b | 1140 | if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) { |
4e23471a CH |
1141 | trace_xfs_bdstrat_shut(bp, _RET_IP_); |
1142 | /* | |
1143 | * Metadata write that didn't get logged but | |
1144 | * written delayed anyway. These aren't associated | |
1145 | * with a transaction, and can be ignored. | |
1146 | */ | |
1147 | if (!bp->b_iodone && !XFS_BUF_ISREAD(bp)) | |
1148 | return xfs_bioerror_relse(bp); | |
1149 | else | |
1150 | return xfs_bioerror(bp); | |
1151 | } | |
1152 | ||
1153 | xfs_buf_iorequest(bp); | |
1154 | return 0; | |
1155 | } | |
1156 | ||
1157 | /* | |
1158 | * Wrapper around bdstrat so that we can stop data from going to disk in case | |
1159 | * we are shutting down the filesystem. Typically user data goes thru this | |
1160 | * path; one of the exceptions is the superblock. | |
1161 | */ | |
1162 | void | |
1163 | xfsbdstrat( | |
1164 | struct xfs_mount *mp, | |
1165 | struct xfs_buf *bp) | |
1166 | { | |
1167 | if (XFS_FORCED_SHUTDOWN(mp)) { | |
1168 | trace_xfs_bdstrat_shut(bp, _RET_IP_); | |
1169 | xfs_bioerror_relse(bp); | |
1170 | return; | |
1171 | } | |
1172 | ||
1173 | xfs_buf_iorequest(bp); | |
1174 | } | |
1175 | ||
b8f82a4a | 1176 | STATIC void |
ce8e922c NS |
1177 | _xfs_buf_ioend( |
1178 | xfs_buf_t *bp, | |
1da177e4 LT |
1179 | int schedule) |
1180 | { | |
0e6e847f | 1181 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) |
ce8e922c | 1182 | xfs_buf_ioend(bp, schedule); |
1da177e4 LT |
1183 | } |
1184 | ||
782e3b3b | 1185 | STATIC void |
ce8e922c | 1186 | xfs_buf_bio_end_io( |
1da177e4 | 1187 | struct bio *bio, |
1da177e4 LT |
1188 | int error) |
1189 | { | |
ce8e922c | 1190 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1da177e4 | 1191 | |
cfbe5267 | 1192 | xfs_buf_ioerror(bp, -error); |
1da177e4 | 1193 | |
73c77e2c JB |
1194 | if (!error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ)) |
1195 | invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp)); | |
1196 | ||
ce8e922c | 1197 | _xfs_buf_ioend(bp, 1); |
1da177e4 | 1198 | bio_put(bio); |
1da177e4 LT |
1199 | } |
1200 | ||
1201 | STATIC void | |
ce8e922c NS |
1202 | _xfs_buf_ioapply( |
1203 | xfs_buf_t *bp) | |
1da177e4 | 1204 | { |
a9759f2d | 1205 | int rw, map_i, total_nr_pages, nr_pages; |
1da177e4 | 1206 | struct bio *bio; |
ce8e922c NS |
1207 | int offset = bp->b_offset; |
1208 | int size = bp->b_count_desired; | |
1209 | sector_t sector = bp->b_bn; | |
1da177e4 | 1210 | |
ce8e922c | 1211 | total_nr_pages = bp->b_page_count; |
1da177e4 LT |
1212 | map_i = 0; |
1213 | ||
ce8e922c NS |
1214 | if (bp->b_flags & XBF_ORDERED) { |
1215 | ASSERT(!(bp->b_flags & XBF_READ)); | |
80f6c29d | 1216 | rw = WRITE_FLUSH_FUA; |
2ee1abad | 1217 | } else if (bp->b_flags & XBF_LOG_BUFFER) { |
51bdd706 NS |
1218 | ASSERT(!(bp->b_flags & XBF_READ_AHEAD)); |
1219 | bp->b_flags &= ~_XBF_RUN_QUEUES; | |
1220 | rw = (bp->b_flags & XBF_WRITE) ? WRITE_SYNC : READ_SYNC; | |
2ee1abad DC |
1221 | } else if (bp->b_flags & _XBF_RUN_QUEUES) { |
1222 | ASSERT(!(bp->b_flags & XBF_READ_AHEAD)); | |
1223 | bp->b_flags &= ~_XBF_RUN_QUEUES; | |
1224 | rw = (bp->b_flags & XBF_WRITE) ? WRITE_META : READ_META; | |
51bdd706 NS |
1225 | } else { |
1226 | rw = (bp->b_flags & XBF_WRITE) ? WRITE : | |
1227 | (bp->b_flags & XBF_READ_AHEAD) ? READA : READ; | |
f538d4da CH |
1228 | } |
1229 | ||
1da177e4 | 1230 | |
1da177e4 | 1231 | next_chunk: |
ce8e922c | 1232 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1233 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1234 | if (nr_pages > total_nr_pages) | |
1235 | nr_pages = total_nr_pages; | |
1236 | ||
1237 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1238 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1239 | bio->bi_sector = sector; |
ce8e922c NS |
1240 | bio->bi_end_io = xfs_buf_bio_end_io; |
1241 | bio->bi_private = bp; | |
1da177e4 | 1242 | |
0e6e847f | 1243 | |
1da177e4 | 1244 | for (; size && nr_pages; nr_pages--, map_i++) { |
0e6e847f | 1245 | int rbytes, nbytes = PAGE_SIZE - offset; |
1da177e4 LT |
1246 | |
1247 | if (nbytes > size) | |
1248 | nbytes = size; | |
1249 | ||
ce8e922c NS |
1250 | rbytes = bio_add_page(bio, bp->b_pages[map_i], nbytes, offset); |
1251 | if (rbytes < nbytes) | |
1da177e4 LT |
1252 | break; |
1253 | ||
1254 | offset = 0; | |
1255 | sector += nbytes >> BBSHIFT; | |
1256 | size -= nbytes; | |
1257 | total_nr_pages--; | |
1258 | } | |
1259 | ||
1da177e4 | 1260 | if (likely(bio->bi_size)) { |
73c77e2c JB |
1261 | if (xfs_buf_is_vmapped(bp)) { |
1262 | flush_kernel_vmap_range(bp->b_addr, | |
1263 | xfs_buf_vmap_len(bp)); | |
1264 | } | |
1da177e4 LT |
1265 | submit_bio(rw, bio); |
1266 | if (size) | |
1267 | goto next_chunk; | |
1268 | } else { | |
ce8e922c | 1269 | xfs_buf_ioerror(bp, EIO); |
ec53d1db | 1270 | bio_put(bio); |
1da177e4 LT |
1271 | } |
1272 | } | |
1273 | ||
1da177e4 | 1274 | int |
ce8e922c NS |
1275 | xfs_buf_iorequest( |
1276 | xfs_buf_t *bp) | |
1da177e4 | 1277 | { |
0b1b213f | 1278 | trace_xfs_buf_iorequest(bp, _RET_IP_); |
1da177e4 | 1279 | |
ce8e922c NS |
1280 | if (bp->b_flags & XBF_DELWRI) { |
1281 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1282 | return 0; |
1283 | } | |
1284 | ||
ce8e922c NS |
1285 | if (bp->b_flags & XBF_WRITE) { |
1286 | xfs_buf_wait_unpin(bp); | |
1da177e4 LT |
1287 | } |
1288 | ||
ce8e922c | 1289 | xfs_buf_hold(bp); |
1da177e4 LT |
1290 | |
1291 | /* Set the count to 1 initially, this will stop an I/O | |
1292 | * completion callout which happens before we have started | |
ce8e922c | 1293 | * all the I/O from calling xfs_buf_ioend too early. |
1da177e4 | 1294 | */ |
ce8e922c NS |
1295 | atomic_set(&bp->b_io_remaining, 1); |
1296 | _xfs_buf_ioapply(bp); | |
1297 | _xfs_buf_ioend(bp, 0); | |
1da177e4 | 1298 | |
ce8e922c | 1299 | xfs_buf_rele(bp); |
1da177e4 LT |
1300 | return 0; |
1301 | } | |
1302 | ||
1303 | /* | |
ce8e922c NS |
1304 | * Waits for I/O to complete on the buffer supplied. |
1305 | * It returns immediately if no I/O is pending. | |
1306 | * It returns the I/O error code, if any, or 0 if there was no error. | |
1da177e4 LT |
1307 | */ |
1308 | int | |
ce8e922c NS |
1309 | xfs_buf_iowait( |
1310 | xfs_buf_t *bp) | |
1da177e4 | 1311 | { |
0b1b213f CH |
1312 | trace_xfs_buf_iowait(bp, _RET_IP_); |
1313 | ||
ce8e922c | 1314 | if (atomic_read(&bp->b_io_remaining)) |
0e6e847f | 1315 | blk_run_backing_dev(bp->b_target->bt_bdi, NULL); |
b4dd330b | 1316 | wait_for_completion(&bp->b_iowait); |
0b1b213f CH |
1317 | |
1318 | trace_xfs_buf_iowait_done(bp, _RET_IP_); | |
ce8e922c | 1319 | return bp->b_error; |
1da177e4 LT |
1320 | } |
1321 | ||
ce8e922c NS |
1322 | xfs_caddr_t |
1323 | xfs_buf_offset( | |
1324 | xfs_buf_t *bp, | |
1da177e4 LT |
1325 | size_t offset) |
1326 | { | |
1327 | struct page *page; | |
1328 | ||
ce8e922c NS |
1329 | if (bp->b_flags & XBF_MAPPED) |
1330 | return XFS_BUF_PTR(bp) + offset; | |
1da177e4 | 1331 | |
ce8e922c | 1332 | offset += bp->b_offset; |
0e6e847f DC |
1333 | page = bp->b_pages[offset >> PAGE_SHIFT]; |
1334 | return (xfs_caddr_t)page_address(page) + (offset & (PAGE_SIZE-1)); | |
1da177e4 LT |
1335 | } |
1336 | ||
1337 | /* | |
1da177e4 LT |
1338 | * Move data into or out of a buffer. |
1339 | */ | |
1340 | void | |
ce8e922c NS |
1341 | xfs_buf_iomove( |
1342 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1343 | size_t boff, /* starting buffer offset */ |
1344 | size_t bsize, /* length to copy */ | |
b9c48649 | 1345 | void *data, /* data address */ |
ce8e922c | 1346 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 LT |
1347 | { |
1348 | size_t bend, cpoff, csize; | |
1349 | struct page *page; | |
1350 | ||
1351 | bend = boff + bsize; | |
1352 | while (boff < bend) { | |
ce8e922c NS |
1353 | page = bp->b_pages[xfs_buf_btoct(boff + bp->b_offset)]; |
1354 | cpoff = xfs_buf_poff(boff + bp->b_offset); | |
1da177e4 | 1355 | csize = min_t(size_t, |
0e6e847f | 1356 | PAGE_SIZE-cpoff, bp->b_count_desired-boff); |
1da177e4 | 1357 | |
0e6e847f | 1358 | ASSERT(((csize + cpoff) <= PAGE_SIZE)); |
1da177e4 LT |
1359 | |
1360 | switch (mode) { | |
ce8e922c | 1361 | case XBRW_ZERO: |
1da177e4 LT |
1362 | memset(page_address(page) + cpoff, 0, csize); |
1363 | break; | |
ce8e922c | 1364 | case XBRW_READ: |
1da177e4 LT |
1365 | memcpy(data, page_address(page) + cpoff, csize); |
1366 | break; | |
ce8e922c | 1367 | case XBRW_WRITE: |
1da177e4 LT |
1368 | memcpy(page_address(page) + cpoff, data, csize); |
1369 | } | |
1370 | ||
1371 | boff += csize; | |
1372 | data += csize; | |
1373 | } | |
1374 | } | |
1375 | ||
1376 | /* | |
ce8e922c | 1377 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1378 | */ |
1379 | ||
1380 | /* | |
430cbeb8 DC |
1381 | * Wait for any bufs with callbacks that have been submitted but have not yet |
1382 | * returned. These buffers will have an elevated hold count, so wait on those | |
1383 | * while freeing all the buffers only held by the LRU. | |
1da177e4 LT |
1384 | */ |
1385 | void | |
1386 | xfs_wait_buftarg( | |
74f75a0c | 1387 | struct xfs_buftarg *btp) |
1da177e4 | 1388 | { |
430cbeb8 DC |
1389 | struct xfs_buf *bp; |
1390 | ||
1391 | restart: | |
1392 | spin_lock(&btp->bt_lru_lock); | |
1393 | while (!list_empty(&btp->bt_lru)) { | |
1394 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1395 | if (atomic_read(&bp->b_hold) > 1) { | |
1396 | spin_unlock(&btp->bt_lru_lock); | |
26af6552 | 1397 | delay(100); |
430cbeb8 | 1398 | goto restart; |
1da177e4 | 1399 | } |
430cbeb8 DC |
1400 | /* |
1401 | * clear the LRU reference count so the bufer doesn't get | |
1402 | * ignored in xfs_buf_rele(). | |
1403 | */ | |
1404 | atomic_set(&bp->b_lru_ref, 0); | |
1405 | spin_unlock(&btp->bt_lru_lock); | |
1406 | xfs_buf_rele(bp); | |
1407 | spin_lock(&btp->bt_lru_lock); | |
1da177e4 | 1408 | } |
430cbeb8 | 1409 | spin_unlock(&btp->bt_lru_lock); |
1da177e4 LT |
1410 | } |
1411 | ||
ff57ab21 DC |
1412 | int |
1413 | xfs_buftarg_shrink( | |
1414 | struct shrinker *shrink, | |
1415 | int nr_to_scan, | |
1416 | gfp_t mask) | |
a6867a68 | 1417 | { |
ff57ab21 DC |
1418 | struct xfs_buftarg *btp = container_of(shrink, |
1419 | struct xfs_buftarg, bt_shrinker); | |
430cbeb8 DC |
1420 | struct xfs_buf *bp; |
1421 | LIST_HEAD(dispose); | |
1422 | ||
1423 | if (!nr_to_scan) | |
1424 | return btp->bt_lru_nr; | |
1425 | ||
1426 | spin_lock(&btp->bt_lru_lock); | |
1427 | while (!list_empty(&btp->bt_lru)) { | |
1428 | if (nr_to_scan-- <= 0) | |
1429 | break; | |
1430 | ||
1431 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1432 | ||
1433 | /* | |
1434 | * Decrement the b_lru_ref count unless the value is already | |
1435 | * zero. If the value is already zero, we need to reclaim the | |
1436 | * buffer, otherwise it gets another trip through the LRU. | |
1437 | */ | |
1438 | if (!atomic_add_unless(&bp->b_lru_ref, -1, 0)) { | |
1439 | list_move_tail(&bp->b_lru, &btp->bt_lru); | |
1440 | continue; | |
1441 | } | |
1442 | ||
1443 | /* | |
1444 | * remove the buffer from the LRU now to avoid needing another | |
1445 | * lock round trip inside xfs_buf_rele(). | |
1446 | */ | |
1447 | list_move(&bp->b_lru, &dispose); | |
1448 | btp->bt_lru_nr--; | |
ff57ab21 | 1449 | } |
430cbeb8 DC |
1450 | spin_unlock(&btp->bt_lru_lock); |
1451 | ||
1452 | while (!list_empty(&dispose)) { | |
1453 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); | |
1454 | list_del_init(&bp->b_lru); | |
1455 | xfs_buf_rele(bp); | |
1456 | } | |
1457 | ||
1458 | return btp->bt_lru_nr; | |
a6867a68 DC |
1459 | } |
1460 | ||
1da177e4 LT |
1461 | void |
1462 | xfs_free_buftarg( | |
b7963133 CH |
1463 | struct xfs_mount *mp, |
1464 | struct xfs_buftarg *btp) | |
1da177e4 | 1465 | { |
ff57ab21 DC |
1466 | unregister_shrinker(&btp->bt_shrinker); |
1467 | ||
1da177e4 | 1468 | xfs_flush_buftarg(btp, 1); |
b7963133 CH |
1469 | if (mp->m_flags & XFS_MOUNT_BARRIER) |
1470 | xfs_blkdev_issue_flush(btp); | |
a6867a68 | 1471 | |
a6867a68 | 1472 | kthread_stop(btp->bt_task); |
f0e2d93c | 1473 | kmem_free(btp); |
1da177e4 LT |
1474 | } |
1475 | ||
1da177e4 LT |
1476 | STATIC int |
1477 | xfs_setsize_buftarg_flags( | |
1478 | xfs_buftarg_t *btp, | |
1479 | unsigned int blocksize, | |
1480 | unsigned int sectorsize, | |
1481 | int verbose) | |
1482 | { | |
ce8e922c NS |
1483 | btp->bt_bsize = blocksize; |
1484 | btp->bt_sshift = ffs(sectorsize) - 1; | |
1485 | btp->bt_smask = sectorsize - 1; | |
1da177e4 | 1486 | |
ce8e922c | 1487 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
4f10700a DC |
1488 | xfs_warn(btp->bt_mount, |
1489 | "Cannot set_blocksize to %u on device %s\n", | |
1da177e4 LT |
1490 | sectorsize, XFS_BUFTARG_NAME(btp)); |
1491 | return EINVAL; | |
1492 | } | |
1493 | ||
1da177e4 LT |
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, | |
0e6e847f | 1508 | PAGE_SIZE, bdev_logical_block_size(bdev), 0); |
1da177e4 LT |
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 | ||
a6867a68 DC |
1520 | STATIC int |
1521 | xfs_alloc_delwrite_queue( | |
e2a07812 JE |
1522 | xfs_buftarg_t *btp, |
1523 | const char *fsname) | |
a6867a68 | 1524 | { |
a6867a68 | 1525 | INIT_LIST_HEAD(&btp->bt_delwrite_queue); |
007c61c6 | 1526 | spin_lock_init(&btp->bt_delwrite_lock); |
a6867a68 | 1527 | btp->bt_flags = 0; |
e2a07812 | 1528 | btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd/%s", fsname); |
ff57ab21 DC |
1529 | if (IS_ERR(btp->bt_task)) |
1530 | return PTR_ERR(btp->bt_task); | |
1531 | return 0; | |
a6867a68 DC |
1532 | } |
1533 | ||
1da177e4 LT |
1534 | xfs_buftarg_t * |
1535 | xfs_alloc_buftarg( | |
ebad861b | 1536 | struct xfs_mount *mp, |
1da177e4 | 1537 | struct block_device *bdev, |
e2a07812 JE |
1538 | int external, |
1539 | const char *fsname) | |
1da177e4 LT |
1540 | { |
1541 | xfs_buftarg_t *btp; | |
1542 | ||
1543 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP); | |
1544 | ||
ebad861b | 1545 | btp->bt_mount = mp; |
ce8e922c NS |
1546 | btp->bt_dev = bdev->bd_dev; |
1547 | btp->bt_bdev = bdev; | |
0e6e847f DC |
1548 | btp->bt_bdi = blk_get_backing_dev_info(bdev); |
1549 | if (!btp->bt_bdi) | |
1550 | goto error; | |
1551 | ||
430cbeb8 DC |
1552 | INIT_LIST_HEAD(&btp->bt_lru); |
1553 | spin_lock_init(&btp->bt_lru_lock); | |
1da177e4 LT |
1554 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1555 | goto error; | |
e2a07812 | 1556 | if (xfs_alloc_delwrite_queue(btp, fsname)) |
a6867a68 | 1557 | goto error; |
ff57ab21 DC |
1558 | btp->bt_shrinker.shrink = xfs_buftarg_shrink; |
1559 | btp->bt_shrinker.seeks = DEFAULT_SEEKS; | |
1560 | register_shrinker(&btp->bt_shrinker); | |
1da177e4 LT |
1561 | return btp; |
1562 | ||
1563 | error: | |
f0e2d93c | 1564 | kmem_free(btp); |
1da177e4 LT |
1565 | return NULL; |
1566 | } | |
1567 | ||
1568 | ||
1569 | /* | |
ce8e922c | 1570 | * Delayed write buffer handling |
1da177e4 | 1571 | */ |
1da177e4 | 1572 | STATIC void |
ce8e922c NS |
1573 | xfs_buf_delwri_queue( |
1574 | xfs_buf_t *bp, | |
1da177e4 LT |
1575 | int unlock) |
1576 | { | |
ce8e922c NS |
1577 | struct list_head *dwq = &bp->b_target->bt_delwrite_queue; |
1578 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; | |
a6867a68 | 1579 | |
0b1b213f CH |
1580 | trace_xfs_buf_delwri_queue(bp, _RET_IP_); |
1581 | ||
ce8e922c | 1582 | ASSERT((bp->b_flags&(XBF_DELWRI|XBF_ASYNC)) == (XBF_DELWRI|XBF_ASYNC)); |
1da177e4 | 1583 | |
a6867a68 | 1584 | spin_lock(dwlk); |
1da177e4 | 1585 | /* If already in the queue, dequeue and place at tail */ |
ce8e922c NS |
1586 | if (!list_empty(&bp->b_list)) { |
1587 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1588 | if (unlock) | |
1589 | atomic_dec(&bp->b_hold); | |
1590 | list_del(&bp->b_list); | |
1da177e4 LT |
1591 | } |
1592 | ||
c9c12971 DC |
1593 | if (list_empty(dwq)) { |
1594 | /* start xfsbufd as it is about to have something to do */ | |
1595 | wake_up_process(bp->b_target->bt_task); | |
1596 | } | |
1597 | ||
ce8e922c NS |
1598 | bp->b_flags |= _XBF_DELWRI_Q; |
1599 | list_add_tail(&bp->b_list, dwq); | |
1600 | bp->b_queuetime = jiffies; | |
a6867a68 | 1601 | spin_unlock(dwlk); |
1da177e4 LT |
1602 | |
1603 | if (unlock) | |
ce8e922c | 1604 | xfs_buf_unlock(bp); |
1da177e4 LT |
1605 | } |
1606 | ||
1607 | void | |
ce8e922c NS |
1608 | xfs_buf_delwri_dequeue( |
1609 | xfs_buf_t *bp) | |
1da177e4 | 1610 | { |
ce8e922c | 1611 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; |
1da177e4 LT |
1612 | int dequeued = 0; |
1613 | ||
a6867a68 | 1614 | spin_lock(dwlk); |
ce8e922c NS |
1615 | if ((bp->b_flags & XBF_DELWRI) && !list_empty(&bp->b_list)) { |
1616 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1617 | list_del_init(&bp->b_list); | |
1da177e4 LT |
1618 | dequeued = 1; |
1619 | } | |
ce8e922c | 1620 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); |
a6867a68 | 1621 | spin_unlock(dwlk); |
1da177e4 LT |
1622 | |
1623 | if (dequeued) | |
ce8e922c | 1624 | xfs_buf_rele(bp); |
1da177e4 | 1625 | |
0b1b213f | 1626 | trace_xfs_buf_delwri_dequeue(bp, _RET_IP_); |
1da177e4 LT |
1627 | } |
1628 | ||
d808f617 DC |
1629 | /* |
1630 | * If a delwri buffer needs to be pushed before it has aged out, then promote | |
1631 | * it to the head of the delwri queue so that it will be flushed on the next | |
1632 | * xfsbufd run. We do this by resetting the queuetime of the buffer to be older | |
1633 | * than the age currently needed to flush the buffer. Hence the next time the | |
1634 | * xfsbufd sees it is guaranteed to be considered old enough to flush. | |
1635 | */ | |
1636 | void | |
1637 | xfs_buf_delwri_promote( | |
1638 | struct xfs_buf *bp) | |
1639 | { | |
1640 | struct xfs_buftarg *btp = bp->b_target; | |
1641 | long age = xfs_buf_age_centisecs * msecs_to_jiffies(10) + 1; | |
1642 | ||
1643 | ASSERT(bp->b_flags & XBF_DELWRI); | |
1644 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1645 | ||
1646 | /* | |
1647 | * Check the buffer age before locking the delayed write queue as we | |
1648 | * don't need to promote buffers that are already past the flush age. | |
1649 | */ | |
1650 | if (bp->b_queuetime < jiffies - age) | |
1651 | return; | |
1652 | bp->b_queuetime = jiffies - age; | |
1653 | spin_lock(&btp->bt_delwrite_lock); | |
1654 | list_move(&bp->b_list, &btp->bt_delwrite_queue); | |
1655 | spin_unlock(&btp->bt_delwrite_lock); | |
1656 | } | |
1657 | ||
1da177e4 | 1658 | STATIC void |
ce8e922c | 1659 | xfs_buf_runall_queues( |
1da177e4 LT |
1660 | struct workqueue_struct *queue) |
1661 | { | |
1662 | flush_workqueue(queue); | |
1663 | } | |
1664 | ||
585e6d88 DC |
1665 | /* |
1666 | * Move as many buffers as specified to the supplied list | |
1667 | * idicating if we skipped any buffers to prevent deadlocks. | |
1668 | */ | |
1669 | STATIC int | |
1670 | xfs_buf_delwri_split( | |
1671 | xfs_buftarg_t *target, | |
1672 | struct list_head *list, | |
5e6a07df | 1673 | unsigned long age) |
585e6d88 DC |
1674 | { |
1675 | xfs_buf_t *bp, *n; | |
1676 | struct list_head *dwq = &target->bt_delwrite_queue; | |
1677 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1678 | int skipped = 0; | |
5e6a07df | 1679 | int force; |
585e6d88 | 1680 | |
5e6a07df | 1681 | force = test_and_clear_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
585e6d88 DC |
1682 | INIT_LIST_HEAD(list); |
1683 | spin_lock(dwlk); | |
1684 | list_for_each_entry_safe(bp, n, dwq, b_list) { | |
585e6d88 DC |
1685 | ASSERT(bp->b_flags & XBF_DELWRI); |
1686 | ||
4d16e924 | 1687 | if (!XFS_BUF_ISPINNED(bp) && !xfs_buf_cond_lock(bp)) { |
5e6a07df | 1688 | if (!force && |
585e6d88 DC |
1689 | time_before(jiffies, bp->b_queuetime + age)) { |
1690 | xfs_buf_unlock(bp); | |
1691 | break; | |
1692 | } | |
1693 | ||
1694 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q| | |
1695 | _XBF_RUN_QUEUES); | |
1696 | bp->b_flags |= XBF_WRITE; | |
1697 | list_move_tail(&bp->b_list, list); | |
bfe27419 | 1698 | trace_xfs_buf_delwri_split(bp, _RET_IP_); |
585e6d88 DC |
1699 | } else |
1700 | skipped++; | |
1701 | } | |
1702 | spin_unlock(dwlk); | |
1703 | ||
1704 | return skipped; | |
1705 | ||
1706 | } | |
1707 | ||
089716aa DC |
1708 | /* |
1709 | * Compare function is more complex than it needs to be because | |
1710 | * the return value is only 32 bits and we are doing comparisons | |
1711 | * on 64 bit values | |
1712 | */ | |
1713 | static int | |
1714 | xfs_buf_cmp( | |
1715 | void *priv, | |
1716 | struct list_head *a, | |
1717 | struct list_head *b) | |
1718 | { | |
1719 | struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list); | |
1720 | struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); | |
1721 | xfs_daddr_t diff; | |
1722 | ||
1723 | diff = ap->b_bn - bp->b_bn; | |
1724 | if (diff < 0) | |
1725 | return -1; | |
1726 | if (diff > 0) | |
1727 | return 1; | |
1728 | return 0; | |
1729 | } | |
1730 | ||
1731 | void | |
1732 | xfs_buf_delwri_sort( | |
1733 | xfs_buftarg_t *target, | |
1734 | struct list_head *list) | |
1735 | { | |
1736 | list_sort(NULL, list, xfs_buf_cmp); | |
1737 | } | |
1738 | ||
1da177e4 | 1739 | STATIC int |
23ea4032 | 1740 | xfsbufd( |
585e6d88 | 1741 | void *data) |
1da177e4 | 1742 | { |
089716aa | 1743 | xfs_buftarg_t *target = (xfs_buftarg_t *)data; |
1da177e4 | 1744 | |
1da177e4 LT |
1745 | current->flags |= PF_MEMALLOC; |
1746 | ||
978c7b2f RW |
1747 | set_freezable(); |
1748 | ||
1da177e4 | 1749 | do { |
c9c12971 DC |
1750 | long age = xfs_buf_age_centisecs * msecs_to_jiffies(10); |
1751 | long tout = xfs_buf_timer_centisecs * msecs_to_jiffies(10); | |
089716aa DC |
1752 | int count = 0; |
1753 | struct list_head tmp; | |
c9c12971 | 1754 | |
3e1d1d28 | 1755 | if (unlikely(freezing(current))) { |
ce8e922c | 1756 | set_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
3e1d1d28 | 1757 | refrigerator(); |
abd0cf7a | 1758 | } else { |
ce8e922c | 1759 | clear_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
abd0cf7a | 1760 | } |
1da177e4 | 1761 | |
c9c12971 DC |
1762 | /* sleep for a long time if there is nothing to do. */ |
1763 | if (list_empty(&target->bt_delwrite_queue)) | |
1764 | tout = MAX_SCHEDULE_TIMEOUT; | |
1765 | schedule_timeout_interruptible(tout); | |
1da177e4 | 1766 | |
c9c12971 | 1767 | xfs_buf_delwri_split(target, &tmp, age); |
089716aa | 1768 | list_sort(NULL, &tmp, xfs_buf_cmp); |
1da177e4 | 1769 | while (!list_empty(&tmp)) { |
089716aa DC |
1770 | struct xfs_buf *bp; |
1771 | bp = list_first_entry(&tmp, struct xfs_buf, b_list); | |
ce8e922c | 1772 | list_del_init(&bp->b_list); |
939d723b | 1773 | xfs_bdstrat_cb(bp); |
585e6d88 | 1774 | count++; |
1da177e4 | 1775 | } |
f07c2250 | 1776 | if (count) |
0e6e847f | 1777 | blk_run_backing_dev(target->bt_bdi, NULL); |
1da177e4 | 1778 | |
4df08c52 | 1779 | } while (!kthread_should_stop()); |
1da177e4 | 1780 | |
4df08c52 | 1781 | return 0; |
1da177e4 LT |
1782 | } |
1783 | ||
1784 | /* | |
ce8e922c NS |
1785 | * Go through all incore buffers, and release buffers if they belong to |
1786 | * the given device. This is used in filesystem error handling to | |
1787 | * preserve the consistency of its metadata. | |
1da177e4 LT |
1788 | */ |
1789 | int | |
1790 | xfs_flush_buftarg( | |
585e6d88 DC |
1791 | xfs_buftarg_t *target, |
1792 | int wait) | |
1da177e4 | 1793 | { |
089716aa | 1794 | xfs_buf_t *bp; |
585e6d88 | 1795 | int pincount = 0; |
089716aa DC |
1796 | LIST_HEAD(tmp_list); |
1797 | LIST_HEAD(wait_list); | |
1da177e4 | 1798 | |
c626d174 | 1799 | xfs_buf_runall_queues(xfsconvertd_workqueue); |
ce8e922c NS |
1800 | xfs_buf_runall_queues(xfsdatad_workqueue); |
1801 | xfs_buf_runall_queues(xfslogd_workqueue); | |
1da177e4 | 1802 | |
5e6a07df | 1803 | set_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
089716aa | 1804 | pincount = xfs_buf_delwri_split(target, &tmp_list, 0); |
1da177e4 LT |
1805 | |
1806 | /* | |
089716aa DC |
1807 | * Dropped the delayed write list lock, now walk the temporary list. |
1808 | * All I/O is issued async and then if we need to wait for completion | |
1809 | * we do that after issuing all the IO. | |
1da177e4 | 1810 | */ |
089716aa DC |
1811 | list_sort(NULL, &tmp_list, xfs_buf_cmp); |
1812 | while (!list_empty(&tmp_list)) { | |
1813 | bp = list_first_entry(&tmp_list, struct xfs_buf, b_list); | |
585e6d88 | 1814 | ASSERT(target == bp->b_target); |
089716aa DC |
1815 | list_del_init(&bp->b_list); |
1816 | if (wait) { | |
ce8e922c | 1817 | bp->b_flags &= ~XBF_ASYNC; |
089716aa DC |
1818 | list_add(&bp->b_list, &wait_list); |
1819 | } | |
939d723b | 1820 | xfs_bdstrat_cb(bp); |
1da177e4 LT |
1821 | } |
1822 | ||
089716aa DC |
1823 | if (wait) { |
1824 | /* Expedite and wait for IO to complete. */ | |
0e6e847f | 1825 | blk_run_backing_dev(target->bt_bdi, NULL); |
089716aa DC |
1826 | while (!list_empty(&wait_list)) { |
1827 | bp = list_first_entry(&wait_list, struct xfs_buf, b_list); | |
f07c2250 | 1828 | |
089716aa | 1829 | list_del_init(&bp->b_list); |
1a1a3e97 | 1830 | xfs_buf_iowait(bp); |
089716aa DC |
1831 | xfs_buf_relse(bp); |
1832 | } | |
1da177e4 LT |
1833 | } |
1834 | ||
1da177e4 LT |
1835 | return pincount; |
1836 | } | |
1837 | ||
04d8b284 | 1838 | int __init |
ce8e922c | 1839 | xfs_buf_init(void) |
1da177e4 | 1840 | { |
8758280f NS |
1841 | xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf", |
1842 | KM_ZONE_HWALIGN, NULL); | |
ce8e922c | 1843 | if (!xfs_buf_zone) |
0b1b213f | 1844 | goto out; |
04d8b284 | 1845 | |
51749e47 | 1846 | xfslogd_workqueue = alloc_workqueue("xfslogd", |
6370a6ad | 1847 | WQ_MEM_RECLAIM | WQ_HIGHPRI, 1); |
23ea4032 | 1848 | if (!xfslogd_workqueue) |
04d8b284 | 1849 | goto out_free_buf_zone; |
1da177e4 | 1850 | |
b4337692 | 1851 | xfsdatad_workqueue = create_workqueue("xfsdatad"); |
23ea4032 CH |
1852 | if (!xfsdatad_workqueue) |
1853 | goto out_destroy_xfslogd_workqueue; | |
1da177e4 | 1854 | |
c626d174 DC |
1855 | xfsconvertd_workqueue = create_workqueue("xfsconvertd"); |
1856 | if (!xfsconvertd_workqueue) | |
1857 | goto out_destroy_xfsdatad_workqueue; | |
1858 | ||
23ea4032 | 1859 | return 0; |
1da177e4 | 1860 | |
c626d174 DC |
1861 | out_destroy_xfsdatad_workqueue: |
1862 | destroy_workqueue(xfsdatad_workqueue); | |
23ea4032 CH |
1863 | out_destroy_xfslogd_workqueue: |
1864 | destroy_workqueue(xfslogd_workqueue); | |
23ea4032 | 1865 | out_free_buf_zone: |
ce8e922c | 1866 | kmem_zone_destroy(xfs_buf_zone); |
0b1b213f | 1867 | out: |
8758280f | 1868 | return -ENOMEM; |
1da177e4 LT |
1869 | } |
1870 | ||
1da177e4 | 1871 | void |
ce8e922c | 1872 | xfs_buf_terminate(void) |
1da177e4 | 1873 | { |
c626d174 | 1874 | destroy_workqueue(xfsconvertd_workqueue); |
04d8b284 CH |
1875 | destroy_workqueue(xfsdatad_workqueue); |
1876 | destroy_workqueue(xfslogd_workqueue); | |
ce8e922c | 1877 | kmem_zone_destroy(xfs_buf_zone); |
1da177e4 | 1878 | } |
e6a0e9cd TS |
1879 | |
1880 | #ifdef CONFIG_KDB_MODULES | |
1881 | struct list_head * | |
1882 | xfs_get_buftarg_list(void) | |
1883 | { | |
1884 | return &xfs_buftarg_list; | |
1885 | } | |
1886 | #endif |