]>
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> |
1da177e4 | 36 | |
b7963133 CH |
37 | #include "xfs_sb.h" |
38 | #include "xfs_inum.h" | |
ed3b4d6c | 39 | #include "xfs_log.h" |
b7963133 | 40 | #include "xfs_ag.h" |
b7963133 | 41 | #include "xfs_mount.h" |
0b1b213f | 42 | #include "xfs_trace.h" |
b7963133 | 43 | |
7989cb8e | 44 | static kmem_zone_t *xfs_buf_zone; |
a6867a68 | 45 | STATIC int xfsbufd(void *); |
ce8e922c | 46 | STATIC void xfs_buf_delwri_queue(xfs_buf_t *, int); |
23ea4032 | 47 | |
7989cb8e | 48 | static struct workqueue_struct *xfslogd_workqueue; |
0829c360 | 49 | struct workqueue_struct *xfsdatad_workqueue; |
c626d174 | 50 | struct workqueue_struct *xfsconvertd_workqueue; |
1da177e4 | 51 | |
ce8e922c NS |
52 | #ifdef XFS_BUF_LOCK_TRACKING |
53 | # define XB_SET_OWNER(bp) ((bp)->b_last_holder = current->pid) | |
54 | # define XB_CLEAR_OWNER(bp) ((bp)->b_last_holder = -1) | |
55 | # define XB_GET_OWNER(bp) ((bp)->b_last_holder) | |
1da177e4 | 56 | #else |
ce8e922c NS |
57 | # define XB_SET_OWNER(bp) do { } while (0) |
58 | # define XB_CLEAR_OWNER(bp) do { } while (0) | |
59 | # define XB_GET_OWNER(bp) do { } while (0) | |
1da177e4 LT |
60 | #endif |
61 | ||
ce8e922c NS |
62 | #define xb_to_gfp(flags) \ |
63 | ((((flags) & XBF_READ_AHEAD) ? __GFP_NORETRY : \ | |
64 | ((flags) & XBF_DONT_BLOCK) ? GFP_NOFS : GFP_KERNEL) | __GFP_NOWARN) | |
1da177e4 | 65 | |
ce8e922c NS |
66 | #define xb_to_km(flags) \ |
67 | (((flags) & XBF_DONT_BLOCK) ? KM_NOFS : KM_SLEEP) | |
1da177e4 | 68 | |
ce8e922c NS |
69 | #define xfs_buf_allocate(flags) \ |
70 | kmem_zone_alloc(xfs_buf_zone, xb_to_km(flags)) | |
71 | #define xfs_buf_deallocate(bp) \ | |
72 | kmem_zone_free(xfs_buf_zone, (bp)); | |
1da177e4 | 73 | |
73c77e2c JB |
74 | static inline int |
75 | xfs_buf_is_vmapped( | |
76 | struct xfs_buf *bp) | |
77 | { | |
78 | /* | |
79 | * Return true if the buffer is vmapped. | |
80 | * | |
81 | * The XBF_MAPPED flag is set if the buffer should be mapped, but the | |
82 | * code is clever enough to know it doesn't have to map a single page, | |
83 | * so the check has to be both for XBF_MAPPED and bp->b_page_count > 1. | |
84 | */ | |
85 | return (bp->b_flags & XBF_MAPPED) && bp->b_page_count > 1; | |
86 | } | |
87 | ||
88 | static inline int | |
89 | xfs_buf_vmap_len( | |
90 | struct xfs_buf *bp) | |
91 | { | |
92 | return (bp->b_page_count * PAGE_SIZE) - bp->b_offset; | |
93 | } | |
94 | ||
1da177e4 | 95 | /* |
430cbeb8 DC |
96 | * xfs_buf_lru_add - add a buffer to the LRU. |
97 | * | |
98 | * The LRU takes a new reference to the buffer so that it will only be freed | |
99 | * once the shrinker takes the buffer off the LRU. | |
100 | */ | |
101 | STATIC void | |
102 | xfs_buf_lru_add( | |
103 | struct xfs_buf *bp) | |
104 | { | |
105 | struct xfs_buftarg *btp = bp->b_target; | |
106 | ||
107 | spin_lock(&btp->bt_lru_lock); | |
108 | if (list_empty(&bp->b_lru)) { | |
109 | atomic_inc(&bp->b_hold); | |
110 | list_add_tail(&bp->b_lru, &btp->bt_lru); | |
111 | btp->bt_lru_nr++; | |
112 | } | |
113 | spin_unlock(&btp->bt_lru_lock); | |
114 | } | |
115 | ||
116 | /* | |
117 | * xfs_buf_lru_del - remove a buffer from the LRU | |
118 | * | |
119 | * The unlocked check is safe here because it only occurs when there are not | |
120 | * b_lru_ref counts left on the inode under the pag->pag_buf_lock. it is there | |
121 | * to optimise the shrinker removing the buffer from the LRU and calling | |
25985edc | 122 | * xfs_buf_free(). i.e. it removes an unnecessary round trip on the |
430cbeb8 | 123 | * bt_lru_lock. |
1da177e4 | 124 | */ |
430cbeb8 DC |
125 | STATIC void |
126 | xfs_buf_lru_del( | |
127 | struct xfs_buf *bp) | |
128 | { | |
129 | struct xfs_buftarg *btp = bp->b_target; | |
130 | ||
131 | if (list_empty(&bp->b_lru)) | |
132 | return; | |
133 | ||
134 | spin_lock(&btp->bt_lru_lock); | |
135 | if (!list_empty(&bp->b_lru)) { | |
136 | list_del_init(&bp->b_lru); | |
137 | btp->bt_lru_nr--; | |
138 | } | |
139 | spin_unlock(&btp->bt_lru_lock); | |
140 | } | |
141 | ||
142 | /* | |
143 | * When we mark a buffer stale, we remove the buffer from the LRU and clear the | |
144 | * b_lru_ref count so that the buffer is freed immediately when the buffer | |
145 | * reference count falls to zero. If the buffer is already on the LRU, we need | |
146 | * to remove the reference that LRU holds on the buffer. | |
147 | * | |
148 | * This prevents build-up of stale buffers on the LRU. | |
149 | */ | |
150 | void | |
151 | xfs_buf_stale( | |
152 | struct xfs_buf *bp) | |
153 | { | |
154 | bp->b_flags |= XBF_STALE; | |
155 | atomic_set(&(bp)->b_lru_ref, 0); | |
156 | if (!list_empty(&bp->b_lru)) { | |
157 | struct xfs_buftarg *btp = bp->b_target; | |
158 | ||
159 | spin_lock(&btp->bt_lru_lock); | |
160 | if (!list_empty(&bp->b_lru)) { | |
161 | list_del_init(&bp->b_lru); | |
162 | btp->bt_lru_nr--; | |
163 | atomic_dec(&bp->b_hold); | |
164 | } | |
165 | spin_unlock(&btp->bt_lru_lock); | |
166 | } | |
167 | ASSERT(atomic_read(&bp->b_hold) >= 1); | |
168 | } | |
1da177e4 LT |
169 | |
170 | STATIC void | |
ce8e922c NS |
171 | _xfs_buf_initialize( |
172 | xfs_buf_t *bp, | |
1da177e4 | 173 | xfs_buftarg_t *target, |
204ab25f | 174 | xfs_off_t range_base, |
1da177e4 | 175 | size_t range_length, |
ce8e922c | 176 | xfs_buf_flags_t flags) |
1da177e4 LT |
177 | { |
178 | /* | |
ce8e922c | 179 | * We don't want certain flags to appear in b_flags. |
1da177e4 | 180 | */ |
ce8e922c NS |
181 | flags &= ~(XBF_LOCK|XBF_MAPPED|XBF_DONT_BLOCK|XBF_READ_AHEAD); |
182 | ||
183 | memset(bp, 0, sizeof(xfs_buf_t)); | |
184 | atomic_set(&bp->b_hold, 1); | |
430cbeb8 | 185 | atomic_set(&bp->b_lru_ref, 1); |
b4dd330b | 186 | init_completion(&bp->b_iowait); |
430cbeb8 | 187 | INIT_LIST_HEAD(&bp->b_lru); |
ce8e922c | 188 | INIT_LIST_HEAD(&bp->b_list); |
74f75a0c | 189 | RB_CLEAR_NODE(&bp->b_rbnode); |
a731cd11 | 190 | sema_init(&bp->b_sema, 0); /* held, no waiters */ |
ce8e922c NS |
191 | XB_SET_OWNER(bp); |
192 | bp->b_target = target; | |
193 | bp->b_file_offset = range_base; | |
1da177e4 LT |
194 | /* |
195 | * Set buffer_length and count_desired to the same value initially. | |
196 | * I/O routines should use count_desired, which will be the same in | |
197 | * most cases but may be reset (e.g. XFS recovery). | |
198 | */ | |
ce8e922c NS |
199 | bp->b_buffer_length = bp->b_count_desired = range_length; |
200 | bp->b_flags = flags; | |
201 | bp->b_bn = XFS_BUF_DADDR_NULL; | |
202 | atomic_set(&bp->b_pin_count, 0); | |
203 | init_waitqueue_head(&bp->b_waiters); | |
204 | ||
205 | XFS_STATS_INC(xb_create); | |
0b1b213f CH |
206 | |
207 | trace_xfs_buf_init(bp, _RET_IP_); | |
1da177e4 LT |
208 | } |
209 | ||
210 | /* | |
ce8e922c NS |
211 | * Allocate a page array capable of holding a specified number |
212 | * of pages, and point the page buf at it. | |
1da177e4 LT |
213 | */ |
214 | STATIC int | |
ce8e922c NS |
215 | _xfs_buf_get_pages( |
216 | xfs_buf_t *bp, | |
1da177e4 | 217 | int page_count, |
ce8e922c | 218 | xfs_buf_flags_t flags) |
1da177e4 LT |
219 | { |
220 | /* Make sure that we have a page list */ | |
ce8e922c NS |
221 | if (bp->b_pages == NULL) { |
222 | bp->b_offset = xfs_buf_poff(bp->b_file_offset); | |
223 | bp->b_page_count = page_count; | |
224 | if (page_count <= XB_PAGES) { | |
225 | bp->b_pages = bp->b_page_array; | |
1da177e4 | 226 | } else { |
ce8e922c NS |
227 | bp->b_pages = kmem_alloc(sizeof(struct page *) * |
228 | page_count, xb_to_km(flags)); | |
229 | if (bp->b_pages == NULL) | |
1da177e4 LT |
230 | return -ENOMEM; |
231 | } | |
ce8e922c | 232 | memset(bp->b_pages, 0, sizeof(struct page *) * page_count); |
1da177e4 LT |
233 | } |
234 | return 0; | |
235 | } | |
236 | ||
237 | /* | |
ce8e922c | 238 | * Frees b_pages if it was allocated. |
1da177e4 LT |
239 | */ |
240 | STATIC void | |
ce8e922c | 241 | _xfs_buf_free_pages( |
1da177e4 LT |
242 | xfs_buf_t *bp) |
243 | { | |
ce8e922c | 244 | if (bp->b_pages != bp->b_page_array) { |
f0e2d93c | 245 | kmem_free(bp->b_pages); |
3fc98b1a | 246 | bp->b_pages = NULL; |
1da177e4 LT |
247 | } |
248 | } | |
249 | ||
250 | /* | |
251 | * Releases the specified buffer. | |
252 | * | |
253 | * The modification state of any associated pages is left unchanged. | |
ce8e922c | 254 | * The buffer most not be on any hash - use xfs_buf_rele instead for |
1da177e4 LT |
255 | * hashed and refcounted buffers |
256 | */ | |
257 | void | |
ce8e922c | 258 | xfs_buf_free( |
1da177e4 LT |
259 | xfs_buf_t *bp) |
260 | { | |
0b1b213f | 261 | trace_xfs_buf_free(bp, _RET_IP_); |
1da177e4 | 262 | |
430cbeb8 DC |
263 | ASSERT(list_empty(&bp->b_lru)); |
264 | ||
0e6e847f | 265 | if (bp->b_flags & _XBF_PAGES) { |
1da177e4 LT |
266 | uint i; |
267 | ||
73c77e2c | 268 | if (xfs_buf_is_vmapped(bp)) |
8a262e57 AE |
269 | vm_unmap_ram(bp->b_addr - bp->b_offset, |
270 | bp->b_page_count); | |
1da177e4 | 271 | |
948ecdb4 NS |
272 | for (i = 0; i < bp->b_page_count; i++) { |
273 | struct page *page = bp->b_pages[i]; | |
274 | ||
0e6e847f | 275 | __free_page(page); |
948ecdb4 | 276 | } |
0e6e847f DC |
277 | } else if (bp->b_flags & _XBF_KMEM) |
278 | kmem_free(bp->b_addr); | |
3fc98b1a | 279 | _xfs_buf_free_pages(bp); |
ce8e922c | 280 | xfs_buf_deallocate(bp); |
1da177e4 LT |
281 | } |
282 | ||
283 | /* | |
0e6e847f | 284 | * Allocates all the pages for buffer in question and builds it's page list. |
1da177e4 LT |
285 | */ |
286 | STATIC int | |
0e6e847f | 287 | xfs_buf_allocate_memory( |
1da177e4 LT |
288 | xfs_buf_t *bp, |
289 | uint flags) | |
290 | { | |
ce8e922c | 291 | size_t size = bp->b_count_desired; |
1da177e4 | 292 | size_t nbytes, offset; |
ce8e922c | 293 | gfp_t gfp_mask = xb_to_gfp(flags); |
1da177e4 | 294 | unsigned short page_count, i; |
204ab25f | 295 | xfs_off_t end; |
1da177e4 LT |
296 | int error; |
297 | ||
0e6e847f DC |
298 | /* |
299 | * for buffers that are contained within a single page, just allocate | |
300 | * the memory from the heap - there's no need for the complexity of | |
301 | * page arrays to keep allocation down to order 0. | |
302 | */ | |
303 | if (bp->b_buffer_length < PAGE_SIZE) { | |
304 | bp->b_addr = kmem_alloc(bp->b_buffer_length, xb_to_km(flags)); | |
305 | if (!bp->b_addr) { | |
306 | /* low memory - use alloc_page loop instead */ | |
307 | goto use_alloc_page; | |
308 | } | |
309 | ||
310 | if (((unsigned long)(bp->b_addr + bp->b_buffer_length - 1) & | |
311 | PAGE_MASK) != | |
312 | ((unsigned long)bp->b_addr & PAGE_MASK)) { | |
313 | /* b_addr spans two pages - use alloc_page instead */ | |
314 | kmem_free(bp->b_addr); | |
315 | bp->b_addr = NULL; | |
316 | goto use_alloc_page; | |
317 | } | |
318 | bp->b_offset = offset_in_page(bp->b_addr); | |
319 | bp->b_pages = bp->b_page_array; | |
320 | bp->b_pages[0] = virt_to_page(bp->b_addr); | |
321 | bp->b_page_count = 1; | |
322 | bp->b_flags |= XBF_MAPPED | _XBF_KMEM; | |
323 | return 0; | |
324 | } | |
325 | ||
326 | use_alloc_page: | |
ce8e922c NS |
327 | end = bp->b_file_offset + bp->b_buffer_length; |
328 | page_count = xfs_buf_btoc(end) - xfs_buf_btoct(bp->b_file_offset); | |
ce8e922c | 329 | error = _xfs_buf_get_pages(bp, page_count, flags); |
1da177e4 LT |
330 | if (unlikely(error)) |
331 | return error; | |
1da177e4 | 332 | |
ce8e922c | 333 | offset = bp->b_offset; |
0e6e847f | 334 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 335 | |
ce8e922c | 336 | for (i = 0; i < bp->b_page_count; i++) { |
1da177e4 LT |
337 | struct page *page; |
338 | uint retries = 0; | |
0e6e847f DC |
339 | retry: |
340 | page = alloc_page(gfp_mask); | |
1da177e4 | 341 | if (unlikely(page == NULL)) { |
ce8e922c NS |
342 | if (flags & XBF_READ_AHEAD) { |
343 | bp->b_page_count = i; | |
0e6e847f DC |
344 | error = ENOMEM; |
345 | goto out_free_pages; | |
1da177e4 LT |
346 | } |
347 | ||
348 | /* | |
349 | * This could deadlock. | |
350 | * | |
351 | * But until all the XFS lowlevel code is revamped to | |
352 | * handle buffer allocation failures we can't do much. | |
353 | */ | |
354 | if (!(++retries % 100)) | |
4f10700a DC |
355 | xfs_err(NULL, |
356 | "possible memory allocation deadlock in %s (mode:0x%x)", | |
34a622b2 | 357 | __func__, gfp_mask); |
1da177e4 | 358 | |
ce8e922c | 359 | XFS_STATS_INC(xb_page_retries); |
8aa7e847 | 360 | congestion_wait(BLK_RW_ASYNC, HZ/50); |
1da177e4 LT |
361 | goto retry; |
362 | } | |
363 | ||
ce8e922c | 364 | XFS_STATS_INC(xb_page_found); |
1da177e4 | 365 | |
0e6e847f | 366 | nbytes = min_t(size_t, size, PAGE_SIZE - offset); |
1da177e4 | 367 | size -= nbytes; |
ce8e922c | 368 | bp->b_pages[i] = page; |
1da177e4 LT |
369 | offset = 0; |
370 | } | |
0e6e847f | 371 | return 0; |
1da177e4 | 372 | |
0e6e847f DC |
373 | out_free_pages: |
374 | for (i = 0; i < bp->b_page_count; i++) | |
375 | __free_page(bp->b_pages[i]); | |
1da177e4 LT |
376 | return error; |
377 | } | |
378 | ||
379 | /* | |
25985edc | 380 | * Map buffer into kernel address-space if necessary. |
1da177e4 LT |
381 | */ |
382 | STATIC int | |
ce8e922c | 383 | _xfs_buf_map_pages( |
1da177e4 LT |
384 | xfs_buf_t *bp, |
385 | uint flags) | |
386 | { | |
0e6e847f | 387 | ASSERT(bp->b_flags & _XBF_PAGES); |
ce8e922c | 388 | if (bp->b_page_count == 1) { |
0e6e847f | 389 | /* A single page buffer is always mappable */ |
ce8e922c NS |
390 | bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; |
391 | bp->b_flags |= XBF_MAPPED; | |
392 | } else if (flags & XBF_MAPPED) { | |
a19fb380 DC |
393 | int retried = 0; |
394 | ||
395 | do { | |
396 | bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, | |
397 | -1, PAGE_KERNEL); | |
398 | if (bp->b_addr) | |
399 | break; | |
400 | vm_unmap_aliases(); | |
401 | } while (retried++ <= 1); | |
402 | ||
403 | if (!bp->b_addr) | |
1da177e4 | 404 | return -ENOMEM; |
ce8e922c NS |
405 | bp->b_addr += bp->b_offset; |
406 | bp->b_flags |= XBF_MAPPED; | |
1da177e4 LT |
407 | } |
408 | ||
409 | return 0; | |
410 | } | |
411 | ||
412 | /* | |
413 | * Finding and Reading Buffers | |
414 | */ | |
415 | ||
416 | /* | |
ce8e922c | 417 | * Look up, and creates if absent, a lockable buffer for |
1da177e4 LT |
418 | * a given range of an inode. The buffer is returned |
419 | * locked. If other overlapping buffers exist, they are | |
420 | * released before the new buffer is created and locked, | |
421 | * which may imply that this call will block until those buffers | |
422 | * are unlocked. No I/O is implied by this call. | |
423 | */ | |
424 | xfs_buf_t * | |
ce8e922c | 425 | _xfs_buf_find( |
1da177e4 | 426 | xfs_buftarg_t *btp, /* block device target */ |
204ab25f | 427 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 428 | size_t isize, /* length of range */ |
ce8e922c NS |
429 | xfs_buf_flags_t flags, |
430 | xfs_buf_t *new_bp) | |
1da177e4 | 431 | { |
204ab25f | 432 | xfs_off_t range_base; |
1da177e4 | 433 | size_t range_length; |
74f75a0c DC |
434 | struct xfs_perag *pag; |
435 | struct rb_node **rbp; | |
436 | struct rb_node *parent; | |
437 | xfs_buf_t *bp; | |
1da177e4 LT |
438 | |
439 | range_base = (ioff << BBSHIFT); | |
440 | range_length = (isize << BBSHIFT); | |
441 | ||
442 | /* Check for IOs smaller than the sector size / not sector aligned */ | |
ce8e922c | 443 | ASSERT(!(range_length < (1 << btp->bt_sshift))); |
204ab25f | 444 | ASSERT(!(range_base & (xfs_off_t)btp->bt_smask)); |
1da177e4 | 445 | |
74f75a0c DC |
446 | /* get tree root */ |
447 | pag = xfs_perag_get(btp->bt_mount, | |
448 | xfs_daddr_to_agno(btp->bt_mount, ioff)); | |
449 | ||
450 | /* walk tree */ | |
451 | spin_lock(&pag->pag_buf_lock); | |
452 | rbp = &pag->pag_buf_tree.rb_node; | |
453 | parent = NULL; | |
454 | bp = NULL; | |
455 | while (*rbp) { | |
456 | parent = *rbp; | |
457 | bp = rb_entry(parent, struct xfs_buf, b_rbnode); | |
458 | ||
459 | if (range_base < bp->b_file_offset) | |
460 | rbp = &(*rbp)->rb_left; | |
461 | else if (range_base > bp->b_file_offset) | |
462 | rbp = &(*rbp)->rb_right; | |
463 | else { | |
464 | /* | |
465 | * found a block offset match. If the range doesn't | |
466 | * match, the only way this is allowed is if the buffer | |
467 | * in the cache is stale and the transaction that made | |
468 | * it stale has not yet committed. i.e. we are | |
469 | * reallocating a busy extent. Skip this buffer and | |
470 | * continue searching to the right for an exact match. | |
471 | */ | |
472 | if (bp->b_buffer_length != range_length) { | |
473 | ASSERT(bp->b_flags & XBF_STALE); | |
474 | rbp = &(*rbp)->rb_right; | |
475 | continue; | |
476 | } | |
ce8e922c | 477 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
478 | goto found; |
479 | } | |
480 | } | |
481 | ||
482 | /* No match found */ | |
ce8e922c NS |
483 | if (new_bp) { |
484 | _xfs_buf_initialize(new_bp, btp, range_base, | |
1da177e4 | 485 | range_length, flags); |
74f75a0c DC |
486 | rb_link_node(&new_bp->b_rbnode, parent, rbp); |
487 | rb_insert_color(&new_bp->b_rbnode, &pag->pag_buf_tree); | |
488 | /* the buffer keeps the perag reference until it is freed */ | |
489 | new_bp->b_pag = pag; | |
490 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 491 | } else { |
ce8e922c | 492 | XFS_STATS_INC(xb_miss_locked); |
74f75a0c DC |
493 | spin_unlock(&pag->pag_buf_lock); |
494 | xfs_perag_put(pag); | |
1da177e4 | 495 | } |
ce8e922c | 496 | return new_bp; |
1da177e4 LT |
497 | |
498 | found: | |
74f75a0c DC |
499 | spin_unlock(&pag->pag_buf_lock); |
500 | xfs_perag_put(pag); | |
1da177e4 | 501 | |
90810b9e DC |
502 | if (xfs_buf_cond_lock(bp)) { |
503 | /* failed, so wait for the lock if requested. */ | |
ce8e922c | 504 | if (!(flags & XBF_TRYLOCK)) { |
ce8e922c NS |
505 | xfs_buf_lock(bp); |
506 | XFS_STATS_INC(xb_get_locked_waited); | |
1da177e4 | 507 | } else { |
ce8e922c NS |
508 | xfs_buf_rele(bp); |
509 | XFS_STATS_INC(xb_busy_locked); | |
510 | return NULL; | |
1da177e4 | 511 | } |
1da177e4 LT |
512 | } |
513 | ||
0e6e847f DC |
514 | /* |
515 | * if the buffer is stale, clear all the external state associated with | |
516 | * it. We need to keep flags such as how we allocated the buffer memory | |
517 | * intact here. | |
518 | */ | |
ce8e922c NS |
519 | if (bp->b_flags & XBF_STALE) { |
520 | ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); | |
0e6e847f | 521 | bp->b_flags &= XBF_MAPPED | _XBF_KMEM | _XBF_PAGES; |
2f926587 | 522 | } |
0b1b213f CH |
523 | |
524 | trace_xfs_buf_find(bp, flags, _RET_IP_); | |
ce8e922c NS |
525 | XFS_STATS_INC(xb_get_locked); |
526 | return bp; | |
1da177e4 LT |
527 | } |
528 | ||
529 | /* | |
ce8e922c | 530 | * Assembles a buffer covering the specified range. |
1da177e4 LT |
531 | * Storage in memory for all portions of the buffer will be allocated, |
532 | * although backing storage may not be. | |
533 | */ | |
534 | xfs_buf_t * | |
6ad112bf | 535 | xfs_buf_get( |
1da177e4 | 536 | xfs_buftarg_t *target,/* target for buffer */ |
204ab25f | 537 | xfs_off_t ioff, /* starting offset of range */ |
1da177e4 | 538 | size_t isize, /* length of range */ |
ce8e922c | 539 | xfs_buf_flags_t flags) |
1da177e4 | 540 | { |
ce8e922c | 541 | xfs_buf_t *bp, *new_bp; |
0e6e847f | 542 | int error = 0; |
1da177e4 | 543 | |
ce8e922c NS |
544 | new_bp = xfs_buf_allocate(flags); |
545 | if (unlikely(!new_bp)) | |
1da177e4 LT |
546 | return NULL; |
547 | ||
ce8e922c NS |
548 | bp = _xfs_buf_find(target, ioff, isize, flags, new_bp); |
549 | if (bp == new_bp) { | |
0e6e847f | 550 | error = xfs_buf_allocate_memory(bp, flags); |
1da177e4 LT |
551 | if (error) |
552 | goto no_buffer; | |
553 | } else { | |
ce8e922c NS |
554 | xfs_buf_deallocate(new_bp); |
555 | if (unlikely(bp == NULL)) | |
1da177e4 LT |
556 | return NULL; |
557 | } | |
558 | ||
ce8e922c NS |
559 | if (!(bp->b_flags & XBF_MAPPED)) { |
560 | error = _xfs_buf_map_pages(bp, flags); | |
1da177e4 | 561 | if (unlikely(error)) { |
4f10700a DC |
562 | xfs_warn(target->bt_mount, |
563 | "%s: failed to map pages\n", __func__); | |
1da177e4 LT |
564 | goto no_buffer; |
565 | } | |
566 | } | |
567 | ||
ce8e922c | 568 | XFS_STATS_INC(xb_get); |
1da177e4 LT |
569 | |
570 | /* | |
571 | * Always fill in the block number now, the mapped cases can do | |
572 | * their own overlay of this later. | |
573 | */ | |
ce8e922c NS |
574 | bp->b_bn = ioff; |
575 | bp->b_count_desired = bp->b_buffer_length; | |
1da177e4 | 576 | |
0b1b213f | 577 | trace_xfs_buf_get(bp, flags, _RET_IP_); |
ce8e922c | 578 | return bp; |
1da177e4 LT |
579 | |
580 | no_buffer: | |
ce8e922c NS |
581 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
582 | xfs_buf_unlock(bp); | |
583 | xfs_buf_rele(bp); | |
1da177e4 LT |
584 | return NULL; |
585 | } | |
586 | ||
5d765b97 CH |
587 | STATIC int |
588 | _xfs_buf_read( | |
589 | xfs_buf_t *bp, | |
590 | xfs_buf_flags_t flags) | |
591 | { | |
592 | int status; | |
593 | ||
5d765b97 CH |
594 | ASSERT(!(flags & (XBF_DELWRI|XBF_WRITE))); |
595 | ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL); | |
596 | ||
597 | bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_DELWRI | \ | |
598 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
599 | bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | \ | |
600 | XBF_READ_AHEAD | _XBF_RUN_QUEUES); | |
601 | ||
602 | status = xfs_buf_iorequest(bp); | |
ec53d1db DC |
603 | if (status || XFS_BUF_ISERROR(bp) || (flags & XBF_ASYNC)) |
604 | return status; | |
605 | return xfs_buf_iowait(bp); | |
5d765b97 CH |
606 | } |
607 | ||
1da177e4 | 608 | xfs_buf_t * |
6ad112bf | 609 | xfs_buf_read( |
1da177e4 | 610 | xfs_buftarg_t *target, |
204ab25f | 611 | xfs_off_t ioff, |
1da177e4 | 612 | size_t isize, |
ce8e922c | 613 | xfs_buf_flags_t flags) |
1da177e4 | 614 | { |
ce8e922c NS |
615 | xfs_buf_t *bp; |
616 | ||
617 | flags |= XBF_READ; | |
618 | ||
6ad112bf | 619 | bp = xfs_buf_get(target, ioff, isize, flags); |
ce8e922c | 620 | if (bp) { |
0b1b213f CH |
621 | trace_xfs_buf_read(bp, flags, _RET_IP_); |
622 | ||
ce8e922c | 623 | if (!XFS_BUF_ISDONE(bp)) { |
ce8e922c | 624 | XFS_STATS_INC(xb_get_read); |
5d765b97 | 625 | _xfs_buf_read(bp, flags); |
ce8e922c | 626 | } else if (flags & XBF_ASYNC) { |
1da177e4 LT |
627 | /* |
628 | * Read ahead call which is already satisfied, | |
629 | * drop the buffer | |
630 | */ | |
631 | goto no_buffer; | |
632 | } else { | |
1da177e4 | 633 | /* We do not want read in the flags */ |
ce8e922c | 634 | bp->b_flags &= ~XBF_READ; |
1da177e4 LT |
635 | } |
636 | } | |
637 | ||
ce8e922c | 638 | return bp; |
1da177e4 LT |
639 | |
640 | no_buffer: | |
ce8e922c NS |
641 | if (flags & (XBF_LOCK | XBF_TRYLOCK)) |
642 | xfs_buf_unlock(bp); | |
643 | xfs_buf_rele(bp); | |
1da177e4 LT |
644 | return NULL; |
645 | } | |
646 | ||
1da177e4 | 647 | /* |
ce8e922c NS |
648 | * If we are not low on memory then do the readahead in a deadlock |
649 | * safe manner. | |
1da177e4 LT |
650 | */ |
651 | void | |
ce8e922c | 652 | xfs_buf_readahead( |
1da177e4 | 653 | xfs_buftarg_t *target, |
204ab25f | 654 | xfs_off_t ioff, |
1a1a3e97 | 655 | size_t isize) |
1da177e4 | 656 | { |
0e6e847f | 657 | if (bdi_read_congested(target->bt_bdi)) |
1da177e4 LT |
658 | return; |
659 | ||
1a1a3e97 CH |
660 | xfs_buf_read(target, ioff, isize, |
661 | XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD|XBF_DONT_BLOCK); | |
1da177e4 LT |
662 | } |
663 | ||
5adc94c2 DC |
664 | /* |
665 | * Read an uncached buffer from disk. Allocates and returns a locked | |
666 | * buffer containing the disk contents or nothing. | |
667 | */ | |
668 | struct xfs_buf * | |
669 | xfs_buf_read_uncached( | |
670 | struct xfs_mount *mp, | |
671 | struct xfs_buftarg *target, | |
672 | xfs_daddr_t daddr, | |
673 | size_t length, | |
674 | int flags) | |
675 | { | |
676 | xfs_buf_t *bp; | |
677 | int error; | |
678 | ||
679 | bp = xfs_buf_get_uncached(target, length, flags); | |
680 | if (!bp) | |
681 | return NULL; | |
682 | ||
683 | /* set up the buffer for a read IO */ | |
684 | xfs_buf_lock(bp); | |
685 | XFS_BUF_SET_ADDR(bp, daddr); | |
686 | XFS_BUF_READ(bp); | |
687 | XFS_BUF_BUSY(bp); | |
688 | ||
689 | xfsbdstrat(mp, bp); | |
1a1a3e97 | 690 | error = xfs_buf_iowait(bp); |
5adc94c2 DC |
691 | if (error || bp->b_error) { |
692 | xfs_buf_relse(bp); | |
693 | return NULL; | |
694 | } | |
695 | return bp; | |
1da177e4 LT |
696 | } |
697 | ||
698 | xfs_buf_t * | |
ce8e922c | 699 | xfs_buf_get_empty( |
1da177e4 LT |
700 | size_t len, |
701 | xfs_buftarg_t *target) | |
702 | { | |
ce8e922c | 703 | xfs_buf_t *bp; |
1da177e4 | 704 | |
ce8e922c NS |
705 | bp = xfs_buf_allocate(0); |
706 | if (bp) | |
707 | _xfs_buf_initialize(bp, target, 0, len, 0); | |
708 | return bp; | |
1da177e4 LT |
709 | } |
710 | ||
44396476 DC |
711 | /* |
712 | * Return a buffer allocated as an empty buffer and associated to external | |
713 | * memory via xfs_buf_associate_memory() back to it's empty state. | |
714 | */ | |
715 | void | |
716 | xfs_buf_set_empty( | |
717 | struct xfs_buf *bp, | |
718 | size_t len) | |
719 | { | |
720 | if (bp->b_pages) | |
721 | _xfs_buf_free_pages(bp); | |
722 | ||
723 | bp->b_pages = NULL; | |
724 | bp->b_page_count = 0; | |
725 | bp->b_addr = NULL; | |
726 | bp->b_file_offset = 0; | |
727 | bp->b_buffer_length = bp->b_count_desired = len; | |
728 | bp->b_bn = XFS_BUF_DADDR_NULL; | |
729 | bp->b_flags &= ~XBF_MAPPED; | |
730 | } | |
731 | ||
1da177e4 LT |
732 | static inline struct page * |
733 | mem_to_page( | |
734 | void *addr) | |
735 | { | |
9e2779fa | 736 | if ((!is_vmalloc_addr(addr))) { |
1da177e4 LT |
737 | return virt_to_page(addr); |
738 | } else { | |
739 | return vmalloc_to_page(addr); | |
740 | } | |
741 | } | |
742 | ||
743 | int | |
ce8e922c NS |
744 | xfs_buf_associate_memory( |
745 | xfs_buf_t *bp, | |
1da177e4 LT |
746 | void *mem, |
747 | size_t len) | |
748 | { | |
749 | int rval; | |
750 | int i = 0; | |
d1afb678 LM |
751 | unsigned long pageaddr; |
752 | unsigned long offset; | |
753 | size_t buflen; | |
1da177e4 LT |
754 | int page_count; |
755 | ||
0e6e847f | 756 | pageaddr = (unsigned long)mem & PAGE_MASK; |
d1afb678 | 757 | offset = (unsigned long)mem - pageaddr; |
0e6e847f DC |
758 | buflen = PAGE_ALIGN(len + offset); |
759 | page_count = buflen >> PAGE_SHIFT; | |
1da177e4 LT |
760 | |
761 | /* Free any previous set of page pointers */ | |
ce8e922c NS |
762 | if (bp->b_pages) |
763 | _xfs_buf_free_pages(bp); | |
1da177e4 | 764 | |
ce8e922c NS |
765 | bp->b_pages = NULL; |
766 | bp->b_addr = mem; | |
1da177e4 | 767 | |
36fae17a | 768 | rval = _xfs_buf_get_pages(bp, page_count, XBF_DONT_BLOCK); |
1da177e4 LT |
769 | if (rval) |
770 | return rval; | |
771 | ||
ce8e922c | 772 | bp->b_offset = offset; |
d1afb678 LM |
773 | |
774 | for (i = 0; i < bp->b_page_count; i++) { | |
775 | bp->b_pages[i] = mem_to_page((void *)pageaddr); | |
0e6e847f | 776 | pageaddr += PAGE_SIZE; |
1da177e4 | 777 | } |
1da177e4 | 778 | |
d1afb678 LM |
779 | bp->b_count_desired = len; |
780 | bp->b_buffer_length = buflen; | |
ce8e922c | 781 | bp->b_flags |= XBF_MAPPED; |
1da177e4 LT |
782 | |
783 | return 0; | |
784 | } | |
785 | ||
786 | xfs_buf_t * | |
686865f7 DC |
787 | xfs_buf_get_uncached( |
788 | struct xfs_buftarg *target, | |
1da177e4 | 789 | size_t len, |
686865f7 | 790 | int flags) |
1da177e4 | 791 | { |
1fa40b01 CH |
792 | unsigned long page_count = PAGE_ALIGN(len) >> PAGE_SHIFT; |
793 | int error, i; | |
1da177e4 | 794 | xfs_buf_t *bp; |
1da177e4 | 795 | |
ce8e922c | 796 | bp = xfs_buf_allocate(0); |
1da177e4 LT |
797 | if (unlikely(bp == NULL)) |
798 | goto fail; | |
ce8e922c | 799 | _xfs_buf_initialize(bp, target, 0, len, 0); |
1da177e4 | 800 | |
1fa40b01 CH |
801 | error = _xfs_buf_get_pages(bp, page_count, 0); |
802 | if (error) | |
1da177e4 LT |
803 | goto fail_free_buf; |
804 | ||
1fa40b01 | 805 | for (i = 0; i < page_count; i++) { |
686865f7 | 806 | bp->b_pages[i] = alloc_page(xb_to_gfp(flags)); |
1fa40b01 CH |
807 | if (!bp->b_pages[i]) |
808 | goto fail_free_mem; | |
1da177e4 | 809 | } |
1fa40b01 | 810 | bp->b_flags |= _XBF_PAGES; |
1da177e4 | 811 | |
1fa40b01 CH |
812 | error = _xfs_buf_map_pages(bp, XBF_MAPPED); |
813 | if (unlikely(error)) { | |
4f10700a DC |
814 | xfs_warn(target->bt_mount, |
815 | "%s: failed to map pages\n", __func__); | |
1da177e4 | 816 | goto fail_free_mem; |
1fa40b01 | 817 | } |
1da177e4 | 818 | |
ce8e922c | 819 | xfs_buf_unlock(bp); |
1da177e4 | 820 | |
686865f7 | 821 | trace_xfs_buf_get_uncached(bp, _RET_IP_); |
1da177e4 | 822 | return bp; |
1fa40b01 | 823 | |
1da177e4 | 824 | fail_free_mem: |
1fa40b01 CH |
825 | while (--i >= 0) |
826 | __free_page(bp->b_pages[i]); | |
ca165b88 | 827 | _xfs_buf_free_pages(bp); |
1da177e4 | 828 | fail_free_buf: |
ca165b88 | 829 | xfs_buf_deallocate(bp); |
1da177e4 LT |
830 | fail: |
831 | return NULL; | |
832 | } | |
833 | ||
834 | /* | |
1da177e4 LT |
835 | * Increment reference count on buffer, to hold the buffer concurrently |
836 | * with another thread which may release (free) the buffer asynchronously. | |
1da177e4 LT |
837 | * Must hold the buffer already to call this function. |
838 | */ | |
839 | void | |
ce8e922c NS |
840 | xfs_buf_hold( |
841 | xfs_buf_t *bp) | |
1da177e4 | 842 | { |
0b1b213f | 843 | trace_xfs_buf_hold(bp, _RET_IP_); |
ce8e922c | 844 | atomic_inc(&bp->b_hold); |
1da177e4 LT |
845 | } |
846 | ||
847 | /* | |
ce8e922c NS |
848 | * Releases a hold on the specified buffer. If the |
849 | * the hold count is 1, calls xfs_buf_free. | |
1da177e4 LT |
850 | */ |
851 | void | |
ce8e922c NS |
852 | xfs_buf_rele( |
853 | xfs_buf_t *bp) | |
1da177e4 | 854 | { |
74f75a0c | 855 | struct xfs_perag *pag = bp->b_pag; |
1da177e4 | 856 | |
0b1b213f | 857 | trace_xfs_buf_rele(bp, _RET_IP_); |
1da177e4 | 858 | |
74f75a0c | 859 | if (!pag) { |
430cbeb8 | 860 | ASSERT(list_empty(&bp->b_lru)); |
74f75a0c | 861 | ASSERT(RB_EMPTY_NODE(&bp->b_rbnode)); |
fad3aa1e NS |
862 | if (atomic_dec_and_test(&bp->b_hold)) |
863 | xfs_buf_free(bp); | |
864 | return; | |
865 | } | |
866 | ||
74f75a0c | 867 | ASSERT(!RB_EMPTY_NODE(&bp->b_rbnode)); |
430cbeb8 | 868 | |
3790689f | 869 | ASSERT(atomic_read(&bp->b_hold) > 0); |
74f75a0c | 870 | if (atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock)) { |
bfc60177 | 871 | if (!(bp->b_flags & XBF_STALE) && |
430cbeb8 DC |
872 | atomic_read(&bp->b_lru_ref)) { |
873 | xfs_buf_lru_add(bp); | |
874 | spin_unlock(&pag->pag_buf_lock); | |
1da177e4 | 875 | } else { |
430cbeb8 | 876 | xfs_buf_lru_del(bp); |
ce8e922c | 877 | ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q))); |
74f75a0c DC |
878 | rb_erase(&bp->b_rbnode, &pag->pag_buf_tree); |
879 | spin_unlock(&pag->pag_buf_lock); | |
880 | xfs_perag_put(pag); | |
ce8e922c | 881 | xfs_buf_free(bp); |
1da177e4 LT |
882 | } |
883 | } | |
884 | } | |
885 | ||
886 | ||
887 | /* | |
0e6e847f | 888 | * Lock a buffer object, if it is not already locked. |
90810b9e DC |
889 | * |
890 | * If we come across a stale, pinned, locked buffer, we know that we are | |
891 | * being asked to lock a buffer that has been reallocated. Because it is | |
892 | * pinned, we know that the log has not been pushed to disk and hence it | |
893 | * will still be locked. Rather than continuing to have trylock attempts | |
894 | * fail until someone else pushes the log, push it ourselves before | |
895 | * returning. This means that the xfsaild will not get stuck trying | |
896 | * to push on stale inode buffers. | |
1da177e4 LT |
897 | */ |
898 | int | |
ce8e922c NS |
899 | xfs_buf_cond_lock( |
900 | xfs_buf_t *bp) | |
1da177e4 LT |
901 | { |
902 | int locked; | |
903 | ||
ce8e922c | 904 | locked = down_trylock(&bp->b_sema) == 0; |
0b1b213f | 905 | if (locked) |
ce8e922c | 906 | XB_SET_OWNER(bp); |
90810b9e DC |
907 | else if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
908 | xfs_log_force(bp->b_target->bt_mount, 0); | |
0b1b213f CH |
909 | |
910 | trace_xfs_buf_cond_lock(bp, _RET_IP_); | |
ce8e922c | 911 | return locked ? 0 : -EBUSY; |
1da177e4 LT |
912 | } |
913 | ||
1da177e4 | 914 | int |
ce8e922c NS |
915 | xfs_buf_lock_value( |
916 | xfs_buf_t *bp) | |
1da177e4 | 917 | { |
adaa693b | 918 | return bp->b_sema.count; |
1da177e4 | 919 | } |
1da177e4 LT |
920 | |
921 | /* | |
0e6e847f | 922 | * Lock a buffer object. |
ed3b4d6c DC |
923 | * |
924 | * If we come across a stale, pinned, locked buffer, we know that we | |
925 | * are being asked to lock a buffer that has been reallocated. Because | |
926 | * it is pinned, we know that the log has not been pushed to disk and | |
927 | * hence it will still be locked. Rather than sleeping until someone | |
928 | * else pushes the log, push it ourselves before trying to get the lock. | |
1da177e4 | 929 | */ |
ce8e922c NS |
930 | void |
931 | xfs_buf_lock( | |
932 | xfs_buf_t *bp) | |
1da177e4 | 933 | { |
0b1b213f CH |
934 | trace_xfs_buf_lock(bp, _RET_IP_); |
935 | ||
ed3b4d6c | 936 | if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) |
ebad861b | 937 | xfs_log_force(bp->b_target->bt_mount, 0); |
ce8e922c NS |
938 | down(&bp->b_sema); |
939 | XB_SET_OWNER(bp); | |
0b1b213f CH |
940 | |
941 | trace_xfs_buf_lock_done(bp, _RET_IP_); | |
1da177e4 LT |
942 | } |
943 | ||
944 | /* | |
ce8e922c | 945 | * Releases the lock on the buffer object. |
2f926587 | 946 | * If the buffer is marked delwri but is not queued, do so before we |
ce8e922c | 947 | * unlock the buffer as we need to set flags correctly. We also need to |
2f926587 DC |
948 | * take a reference for the delwri queue because the unlocker is going to |
949 | * drop their's and they don't know we just queued it. | |
1da177e4 LT |
950 | */ |
951 | void | |
ce8e922c NS |
952 | xfs_buf_unlock( |
953 | xfs_buf_t *bp) | |
1da177e4 | 954 | { |
ce8e922c NS |
955 | if ((bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)) == XBF_DELWRI) { |
956 | atomic_inc(&bp->b_hold); | |
957 | bp->b_flags |= XBF_ASYNC; | |
958 | xfs_buf_delwri_queue(bp, 0); | |
2f926587 DC |
959 | } |
960 | ||
ce8e922c NS |
961 | XB_CLEAR_OWNER(bp); |
962 | up(&bp->b_sema); | |
0b1b213f CH |
963 | |
964 | trace_xfs_buf_unlock(bp, _RET_IP_); | |
1da177e4 LT |
965 | } |
966 | ||
ce8e922c NS |
967 | STATIC void |
968 | xfs_buf_wait_unpin( | |
969 | xfs_buf_t *bp) | |
1da177e4 LT |
970 | { |
971 | DECLARE_WAITQUEUE (wait, current); | |
972 | ||
ce8e922c | 973 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 LT |
974 | return; |
975 | ||
ce8e922c | 976 | add_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
977 | for (;;) { |
978 | set_current_state(TASK_UNINTERRUPTIBLE); | |
ce8e922c | 979 | if (atomic_read(&bp->b_pin_count) == 0) |
1da177e4 | 980 | break; |
7eaceacc | 981 | io_schedule(); |
1da177e4 | 982 | } |
ce8e922c | 983 | remove_wait_queue(&bp->b_waiters, &wait); |
1da177e4 LT |
984 | set_current_state(TASK_RUNNING); |
985 | } | |
986 | ||
987 | /* | |
988 | * Buffer Utility Routines | |
989 | */ | |
990 | ||
1da177e4 | 991 | STATIC void |
ce8e922c | 992 | xfs_buf_iodone_work( |
c4028958 | 993 | struct work_struct *work) |
1da177e4 | 994 | { |
c4028958 DH |
995 | xfs_buf_t *bp = |
996 | container_of(work, xfs_buf_t, b_iodone_work); | |
1da177e4 | 997 | |
80f6c29d | 998 | if (bp->b_iodone) |
ce8e922c NS |
999 | (*(bp->b_iodone))(bp); |
1000 | else if (bp->b_flags & XBF_ASYNC) | |
1da177e4 LT |
1001 | xfs_buf_relse(bp); |
1002 | } | |
1003 | ||
1004 | void | |
ce8e922c NS |
1005 | xfs_buf_ioend( |
1006 | xfs_buf_t *bp, | |
1da177e4 LT |
1007 | int schedule) |
1008 | { | |
0b1b213f CH |
1009 | trace_xfs_buf_iodone(bp, _RET_IP_); |
1010 | ||
77be55a5 | 1011 | bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); |
ce8e922c NS |
1012 | if (bp->b_error == 0) |
1013 | bp->b_flags |= XBF_DONE; | |
1da177e4 | 1014 | |
ce8e922c | 1015 | if ((bp->b_iodone) || (bp->b_flags & XBF_ASYNC)) { |
1da177e4 | 1016 | if (schedule) { |
c4028958 | 1017 | INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work); |
ce8e922c | 1018 | queue_work(xfslogd_workqueue, &bp->b_iodone_work); |
1da177e4 | 1019 | } else { |
c4028958 | 1020 | xfs_buf_iodone_work(&bp->b_iodone_work); |
1da177e4 LT |
1021 | } |
1022 | } else { | |
b4dd330b | 1023 | complete(&bp->b_iowait); |
1da177e4 LT |
1024 | } |
1025 | } | |
1026 | ||
1da177e4 | 1027 | void |
ce8e922c NS |
1028 | xfs_buf_ioerror( |
1029 | xfs_buf_t *bp, | |
1030 | int error) | |
1da177e4 LT |
1031 | { |
1032 | ASSERT(error >= 0 && error <= 0xffff); | |
ce8e922c | 1033 | bp->b_error = (unsigned short)error; |
0b1b213f | 1034 | trace_xfs_buf_ioerror(bp, error, _RET_IP_); |
1da177e4 LT |
1035 | } |
1036 | ||
1da177e4 | 1037 | int |
64e0bc7d CH |
1038 | xfs_bwrite( |
1039 | struct xfs_mount *mp, | |
5d765b97 | 1040 | struct xfs_buf *bp) |
1da177e4 | 1041 | { |
8c38366f | 1042 | int error; |
1da177e4 | 1043 | |
64e0bc7d | 1044 | bp->b_flags |= XBF_WRITE; |
8c38366f | 1045 | bp->b_flags &= ~(XBF_ASYNC | XBF_READ); |
1da177e4 | 1046 | |
5d765b97 | 1047 | xfs_buf_delwri_dequeue(bp); |
939d723b | 1048 | xfs_bdstrat_cb(bp); |
1da177e4 | 1049 | |
8c38366f CH |
1050 | error = xfs_buf_iowait(bp); |
1051 | if (error) | |
1052 | xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR); | |
1053 | xfs_buf_relse(bp); | |
64e0bc7d | 1054 | return error; |
5d765b97 | 1055 | } |
1da177e4 | 1056 | |
5d765b97 CH |
1057 | void |
1058 | xfs_bdwrite( | |
1059 | void *mp, | |
1060 | struct xfs_buf *bp) | |
1061 | { | |
0b1b213f | 1062 | trace_xfs_buf_bdwrite(bp, _RET_IP_); |
1da177e4 | 1063 | |
5d765b97 CH |
1064 | bp->b_flags &= ~XBF_READ; |
1065 | bp->b_flags |= (XBF_DELWRI | XBF_ASYNC); | |
1066 | ||
1067 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1068 | } |
1069 | ||
4e23471a CH |
1070 | /* |
1071 | * Called when we want to stop a buffer from getting written or read. | |
1a1a3e97 | 1072 | * We attach the EIO error, muck with its flags, and call xfs_buf_ioend |
4e23471a CH |
1073 | * so that the proper iodone callbacks get called. |
1074 | */ | |
1075 | STATIC int | |
1076 | xfs_bioerror( | |
1077 | xfs_buf_t *bp) | |
1078 | { | |
1079 | #ifdef XFSERRORDEBUG | |
1080 | ASSERT(XFS_BUF_ISREAD(bp) || bp->b_iodone); | |
1081 | #endif | |
1082 | ||
1083 | /* | |
1084 | * No need to wait until the buffer is unpinned, we aren't flushing it. | |
1085 | */ | |
1086 | XFS_BUF_ERROR(bp, EIO); | |
1087 | ||
1088 | /* | |
1a1a3e97 | 1089 | * We're calling xfs_buf_ioend, so delete XBF_DONE flag. |
4e23471a CH |
1090 | */ |
1091 | XFS_BUF_UNREAD(bp); | |
1092 | XFS_BUF_UNDELAYWRITE(bp); | |
1093 | XFS_BUF_UNDONE(bp); | |
1094 | XFS_BUF_STALE(bp); | |
1095 | ||
1a1a3e97 | 1096 | xfs_buf_ioend(bp, 0); |
4e23471a CH |
1097 | |
1098 | return EIO; | |
1099 | } | |
1100 | ||
1101 | /* | |
1102 | * Same as xfs_bioerror, except that we are releasing the buffer | |
1a1a3e97 | 1103 | * here ourselves, and avoiding the xfs_buf_ioend call. |
4e23471a CH |
1104 | * This is meant for userdata errors; metadata bufs come with |
1105 | * iodone functions attached, so that we can track down errors. | |
1106 | */ | |
1107 | STATIC int | |
1108 | xfs_bioerror_relse( | |
1109 | struct xfs_buf *bp) | |
1110 | { | |
1111 | int64_t fl = XFS_BUF_BFLAGS(bp); | |
1112 | /* | |
1113 | * No need to wait until the buffer is unpinned. | |
1114 | * We aren't flushing it. | |
1115 | * | |
1116 | * chunkhold expects B_DONE to be set, whether | |
1117 | * we actually finish the I/O or not. We don't want to | |
1118 | * change that interface. | |
1119 | */ | |
1120 | XFS_BUF_UNREAD(bp); | |
1121 | XFS_BUF_UNDELAYWRITE(bp); | |
1122 | XFS_BUF_DONE(bp); | |
1123 | XFS_BUF_STALE(bp); | |
1124 | XFS_BUF_CLR_IODONE_FUNC(bp); | |
0cadda1c | 1125 | if (!(fl & XBF_ASYNC)) { |
4e23471a CH |
1126 | /* |
1127 | * Mark b_error and B_ERROR _both_. | |
1128 | * Lot's of chunkcache code assumes that. | |
1129 | * There's no reason to mark error for | |
1130 | * ASYNC buffers. | |
1131 | */ | |
1132 | XFS_BUF_ERROR(bp, EIO); | |
1133 | XFS_BUF_FINISH_IOWAIT(bp); | |
1134 | } else { | |
1135 | xfs_buf_relse(bp); | |
1136 | } | |
1137 | ||
1138 | return EIO; | |
1139 | } | |
1140 | ||
1141 | ||
1142 | /* | |
1143 | * All xfs metadata buffers except log state machine buffers | |
1144 | * get this attached as their b_bdstrat callback function. | |
1145 | * This is so that we can catch a buffer | |
1146 | * after prematurely unpinning it to forcibly shutdown the filesystem. | |
1147 | */ | |
1148 | int | |
1149 | xfs_bdstrat_cb( | |
1150 | struct xfs_buf *bp) | |
1151 | { | |
ebad861b | 1152 | if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) { |
4e23471a CH |
1153 | trace_xfs_bdstrat_shut(bp, _RET_IP_); |
1154 | /* | |
1155 | * Metadata write that didn't get logged but | |
1156 | * written delayed anyway. These aren't associated | |
1157 | * with a transaction, and can be ignored. | |
1158 | */ | |
1159 | if (!bp->b_iodone && !XFS_BUF_ISREAD(bp)) | |
1160 | return xfs_bioerror_relse(bp); | |
1161 | else | |
1162 | return xfs_bioerror(bp); | |
1163 | } | |
1164 | ||
1165 | xfs_buf_iorequest(bp); | |
1166 | return 0; | |
1167 | } | |
1168 | ||
1169 | /* | |
1170 | * Wrapper around bdstrat so that we can stop data from going to disk in case | |
1171 | * we are shutting down the filesystem. Typically user data goes thru this | |
1172 | * path; one of the exceptions is the superblock. | |
1173 | */ | |
1174 | void | |
1175 | xfsbdstrat( | |
1176 | struct xfs_mount *mp, | |
1177 | struct xfs_buf *bp) | |
1178 | { | |
1179 | if (XFS_FORCED_SHUTDOWN(mp)) { | |
1180 | trace_xfs_bdstrat_shut(bp, _RET_IP_); | |
1181 | xfs_bioerror_relse(bp); | |
1182 | return; | |
1183 | } | |
1184 | ||
1185 | xfs_buf_iorequest(bp); | |
1186 | } | |
1187 | ||
b8f82a4a | 1188 | STATIC void |
ce8e922c NS |
1189 | _xfs_buf_ioend( |
1190 | xfs_buf_t *bp, | |
1da177e4 LT |
1191 | int schedule) |
1192 | { | |
0e6e847f | 1193 | if (atomic_dec_and_test(&bp->b_io_remaining) == 1) |
ce8e922c | 1194 | xfs_buf_ioend(bp, schedule); |
1da177e4 LT |
1195 | } |
1196 | ||
782e3b3b | 1197 | STATIC void |
ce8e922c | 1198 | xfs_buf_bio_end_io( |
1da177e4 | 1199 | struct bio *bio, |
1da177e4 LT |
1200 | int error) |
1201 | { | |
ce8e922c | 1202 | xfs_buf_t *bp = (xfs_buf_t *)bio->bi_private; |
1da177e4 | 1203 | |
cfbe5267 | 1204 | xfs_buf_ioerror(bp, -error); |
1da177e4 | 1205 | |
73c77e2c JB |
1206 | if (!error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ)) |
1207 | invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp)); | |
1208 | ||
ce8e922c | 1209 | _xfs_buf_ioend(bp, 1); |
1da177e4 | 1210 | bio_put(bio); |
1da177e4 LT |
1211 | } |
1212 | ||
1213 | STATIC void | |
ce8e922c NS |
1214 | _xfs_buf_ioapply( |
1215 | xfs_buf_t *bp) | |
1da177e4 | 1216 | { |
a9759f2d | 1217 | int rw, map_i, total_nr_pages, nr_pages; |
1da177e4 | 1218 | struct bio *bio; |
ce8e922c NS |
1219 | int offset = bp->b_offset; |
1220 | int size = bp->b_count_desired; | |
1221 | sector_t sector = bp->b_bn; | |
1da177e4 | 1222 | |
ce8e922c | 1223 | total_nr_pages = bp->b_page_count; |
1da177e4 LT |
1224 | map_i = 0; |
1225 | ||
ce8e922c NS |
1226 | if (bp->b_flags & XBF_ORDERED) { |
1227 | ASSERT(!(bp->b_flags & XBF_READ)); | |
80f6c29d | 1228 | rw = WRITE_FLUSH_FUA; |
2ee1abad | 1229 | } else if (bp->b_flags & XBF_LOG_BUFFER) { |
51bdd706 NS |
1230 | ASSERT(!(bp->b_flags & XBF_READ_AHEAD)); |
1231 | bp->b_flags &= ~_XBF_RUN_QUEUES; | |
1232 | rw = (bp->b_flags & XBF_WRITE) ? WRITE_SYNC : READ_SYNC; | |
2ee1abad DC |
1233 | } else if (bp->b_flags & _XBF_RUN_QUEUES) { |
1234 | ASSERT(!(bp->b_flags & XBF_READ_AHEAD)); | |
1235 | bp->b_flags &= ~_XBF_RUN_QUEUES; | |
1236 | rw = (bp->b_flags & XBF_WRITE) ? WRITE_META : READ_META; | |
51bdd706 NS |
1237 | } else { |
1238 | rw = (bp->b_flags & XBF_WRITE) ? WRITE : | |
1239 | (bp->b_flags & XBF_READ_AHEAD) ? READA : READ; | |
f538d4da CH |
1240 | } |
1241 | ||
1da177e4 | 1242 | |
1da177e4 | 1243 | next_chunk: |
ce8e922c | 1244 | atomic_inc(&bp->b_io_remaining); |
1da177e4 LT |
1245 | nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT); |
1246 | if (nr_pages > total_nr_pages) | |
1247 | nr_pages = total_nr_pages; | |
1248 | ||
1249 | bio = bio_alloc(GFP_NOIO, nr_pages); | |
ce8e922c | 1250 | bio->bi_bdev = bp->b_target->bt_bdev; |
1da177e4 | 1251 | bio->bi_sector = sector; |
ce8e922c NS |
1252 | bio->bi_end_io = xfs_buf_bio_end_io; |
1253 | bio->bi_private = bp; | |
1da177e4 | 1254 | |
0e6e847f | 1255 | |
1da177e4 | 1256 | for (; size && nr_pages; nr_pages--, map_i++) { |
0e6e847f | 1257 | int rbytes, nbytes = PAGE_SIZE - offset; |
1da177e4 LT |
1258 | |
1259 | if (nbytes > size) | |
1260 | nbytes = size; | |
1261 | ||
ce8e922c NS |
1262 | rbytes = bio_add_page(bio, bp->b_pages[map_i], nbytes, offset); |
1263 | if (rbytes < nbytes) | |
1da177e4 LT |
1264 | break; |
1265 | ||
1266 | offset = 0; | |
1267 | sector += nbytes >> BBSHIFT; | |
1268 | size -= nbytes; | |
1269 | total_nr_pages--; | |
1270 | } | |
1271 | ||
1da177e4 | 1272 | if (likely(bio->bi_size)) { |
73c77e2c JB |
1273 | if (xfs_buf_is_vmapped(bp)) { |
1274 | flush_kernel_vmap_range(bp->b_addr, | |
1275 | xfs_buf_vmap_len(bp)); | |
1276 | } | |
1da177e4 LT |
1277 | submit_bio(rw, bio); |
1278 | if (size) | |
1279 | goto next_chunk; | |
1280 | } else { | |
ce8e922c | 1281 | xfs_buf_ioerror(bp, EIO); |
ec53d1db | 1282 | bio_put(bio); |
1da177e4 LT |
1283 | } |
1284 | } | |
1285 | ||
1da177e4 | 1286 | int |
ce8e922c NS |
1287 | xfs_buf_iorequest( |
1288 | xfs_buf_t *bp) | |
1da177e4 | 1289 | { |
0b1b213f | 1290 | trace_xfs_buf_iorequest(bp, _RET_IP_); |
1da177e4 | 1291 | |
ce8e922c NS |
1292 | if (bp->b_flags & XBF_DELWRI) { |
1293 | xfs_buf_delwri_queue(bp, 1); | |
1da177e4 LT |
1294 | return 0; |
1295 | } | |
1296 | ||
ce8e922c NS |
1297 | if (bp->b_flags & XBF_WRITE) { |
1298 | xfs_buf_wait_unpin(bp); | |
1da177e4 LT |
1299 | } |
1300 | ||
ce8e922c | 1301 | xfs_buf_hold(bp); |
1da177e4 LT |
1302 | |
1303 | /* Set the count to 1 initially, this will stop an I/O | |
1304 | * completion callout which happens before we have started | |
ce8e922c | 1305 | * all the I/O from calling xfs_buf_ioend too early. |
1da177e4 | 1306 | */ |
ce8e922c NS |
1307 | atomic_set(&bp->b_io_remaining, 1); |
1308 | _xfs_buf_ioapply(bp); | |
1309 | _xfs_buf_ioend(bp, 0); | |
1da177e4 | 1310 | |
ce8e922c | 1311 | xfs_buf_rele(bp); |
1da177e4 LT |
1312 | return 0; |
1313 | } | |
1314 | ||
1315 | /* | |
ce8e922c NS |
1316 | * Waits for I/O to complete on the buffer supplied. |
1317 | * It returns immediately if no I/O is pending. | |
1318 | * It returns the I/O error code, if any, or 0 if there was no error. | |
1da177e4 LT |
1319 | */ |
1320 | int | |
ce8e922c NS |
1321 | xfs_buf_iowait( |
1322 | xfs_buf_t *bp) | |
1da177e4 | 1323 | { |
0b1b213f CH |
1324 | trace_xfs_buf_iowait(bp, _RET_IP_); |
1325 | ||
b4dd330b | 1326 | wait_for_completion(&bp->b_iowait); |
0b1b213f CH |
1327 | |
1328 | trace_xfs_buf_iowait_done(bp, _RET_IP_); | |
ce8e922c | 1329 | return bp->b_error; |
1da177e4 LT |
1330 | } |
1331 | ||
ce8e922c NS |
1332 | xfs_caddr_t |
1333 | xfs_buf_offset( | |
1334 | xfs_buf_t *bp, | |
1da177e4 LT |
1335 | size_t offset) |
1336 | { | |
1337 | struct page *page; | |
1338 | ||
ce8e922c NS |
1339 | if (bp->b_flags & XBF_MAPPED) |
1340 | return XFS_BUF_PTR(bp) + offset; | |
1da177e4 | 1341 | |
ce8e922c | 1342 | offset += bp->b_offset; |
0e6e847f DC |
1343 | page = bp->b_pages[offset >> PAGE_SHIFT]; |
1344 | return (xfs_caddr_t)page_address(page) + (offset & (PAGE_SIZE-1)); | |
1da177e4 LT |
1345 | } |
1346 | ||
1347 | /* | |
1da177e4 LT |
1348 | * Move data into or out of a buffer. |
1349 | */ | |
1350 | void | |
ce8e922c NS |
1351 | xfs_buf_iomove( |
1352 | xfs_buf_t *bp, /* buffer to process */ | |
1da177e4 LT |
1353 | size_t boff, /* starting buffer offset */ |
1354 | size_t bsize, /* length to copy */ | |
b9c48649 | 1355 | void *data, /* data address */ |
ce8e922c | 1356 | xfs_buf_rw_t mode) /* read/write/zero flag */ |
1da177e4 LT |
1357 | { |
1358 | size_t bend, cpoff, csize; | |
1359 | struct page *page; | |
1360 | ||
1361 | bend = boff + bsize; | |
1362 | while (boff < bend) { | |
ce8e922c NS |
1363 | page = bp->b_pages[xfs_buf_btoct(boff + bp->b_offset)]; |
1364 | cpoff = xfs_buf_poff(boff + bp->b_offset); | |
1da177e4 | 1365 | csize = min_t(size_t, |
0e6e847f | 1366 | PAGE_SIZE-cpoff, bp->b_count_desired-boff); |
1da177e4 | 1367 | |
0e6e847f | 1368 | ASSERT(((csize + cpoff) <= PAGE_SIZE)); |
1da177e4 LT |
1369 | |
1370 | switch (mode) { | |
ce8e922c | 1371 | case XBRW_ZERO: |
1da177e4 LT |
1372 | memset(page_address(page) + cpoff, 0, csize); |
1373 | break; | |
ce8e922c | 1374 | case XBRW_READ: |
1da177e4 LT |
1375 | memcpy(data, page_address(page) + cpoff, csize); |
1376 | break; | |
ce8e922c | 1377 | case XBRW_WRITE: |
1da177e4 LT |
1378 | memcpy(page_address(page) + cpoff, data, csize); |
1379 | } | |
1380 | ||
1381 | boff += csize; | |
1382 | data += csize; | |
1383 | } | |
1384 | } | |
1385 | ||
1386 | /* | |
ce8e922c | 1387 | * Handling of buffer targets (buftargs). |
1da177e4 LT |
1388 | */ |
1389 | ||
1390 | /* | |
430cbeb8 DC |
1391 | * Wait for any bufs with callbacks that have been submitted but have not yet |
1392 | * returned. These buffers will have an elevated hold count, so wait on those | |
1393 | * while freeing all the buffers only held by the LRU. | |
1da177e4 LT |
1394 | */ |
1395 | void | |
1396 | xfs_wait_buftarg( | |
74f75a0c | 1397 | struct xfs_buftarg *btp) |
1da177e4 | 1398 | { |
430cbeb8 DC |
1399 | struct xfs_buf *bp; |
1400 | ||
1401 | restart: | |
1402 | spin_lock(&btp->bt_lru_lock); | |
1403 | while (!list_empty(&btp->bt_lru)) { | |
1404 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1405 | if (atomic_read(&bp->b_hold) > 1) { | |
1406 | spin_unlock(&btp->bt_lru_lock); | |
26af6552 | 1407 | delay(100); |
430cbeb8 | 1408 | goto restart; |
1da177e4 | 1409 | } |
430cbeb8 DC |
1410 | /* |
1411 | * clear the LRU reference count so the bufer doesn't get | |
1412 | * ignored in xfs_buf_rele(). | |
1413 | */ | |
1414 | atomic_set(&bp->b_lru_ref, 0); | |
1415 | spin_unlock(&btp->bt_lru_lock); | |
1416 | xfs_buf_rele(bp); | |
1417 | spin_lock(&btp->bt_lru_lock); | |
1da177e4 | 1418 | } |
430cbeb8 | 1419 | spin_unlock(&btp->bt_lru_lock); |
1da177e4 LT |
1420 | } |
1421 | ||
ff57ab21 DC |
1422 | int |
1423 | xfs_buftarg_shrink( | |
1424 | struct shrinker *shrink, | |
1495f230 | 1425 | struct shrink_control *sc) |
a6867a68 | 1426 | { |
ff57ab21 DC |
1427 | struct xfs_buftarg *btp = container_of(shrink, |
1428 | struct xfs_buftarg, bt_shrinker); | |
430cbeb8 | 1429 | struct xfs_buf *bp; |
1495f230 | 1430 | int nr_to_scan = sc->nr_to_scan; |
430cbeb8 DC |
1431 | LIST_HEAD(dispose); |
1432 | ||
1433 | if (!nr_to_scan) | |
1434 | return btp->bt_lru_nr; | |
1435 | ||
1436 | spin_lock(&btp->bt_lru_lock); | |
1437 | while (!list_empty(&btp->bt_lru)) { | |
1438 | if (nr_to_scan-- <= 0) | |
1439 | break; | |
1440 | ||
1441 | bp = list_first_entry(&btp->bt_lru, struct xfs_buf, b_lru); | |
1442 | ||
1443 | /* | |
1444 | * Decrement the b_lru_ref count unless the value is already | |
1445 | * zero. If the value is already zero, we need to reclaim the | |
1446 | * buffer, otherwise it gets another trip through the LRU. | |
1447 | */ | |
1448 | if (!atomic_add_unless(&bp->b_lru_ref, -1, 0)) { | |
1449 | list_move_tail(&bp->b_lru, &btp->bt_lru); | |
1450 | continue; | |
1451 | } | |
1452 | ||
1453 | /* | |
1454 | * remove the buffer from the LRU now to avoid needing another | |
1455 | * lock round trip inside xfs_buf_rele(). | |
1456 | */ | |
1457 | list_move(&bp->b_lru, &dispose); | |
1458 | btp->bt_lru_nr--; | |
ff57ab21 | 1459 | } |
430cbeb8 DC |
1460 | spin_unlock(&btp->bt_lru_lock); |
1461 | ||
1462 | while (!list_empty(&dispose)) { | |
1463 | bp = list_first_entry(&dispose, struct xfs_buf, b_lru); | |
1464 | list_del_init(&bp->b_lru); | |
1465 | xfs_buf_rele(bp); | |
1466 | } | |
1467 | ||
1468 | return btp->bt_lru_nr; | |
a6867a68 DC |
1469 | } |
1470 | ||
1da177e4 LT |
1471 | void |
1472 | xfs_free_buftarg( | |
b7963133 CH |
1473 | struct xfs_mount *mp, |
1474 | struct xfs_buftarg *btp) | |
1da177e4 | 1475 | { |
ff57ab21 DC |
1476 | unregister_shrinker(&btp->bt_shrinker); |
1477 | ||
1da177e4 | 1478 | xfs_flush_buftarg(btp, 1); |
b7963133 CH |
1479 | if (mp->m_flags & XFS_MOUNT_BARRIER) |
1480 | xfs_blkdev_issue_flush(btp); | |
a6867a68 | 1481 | |
a6867a68 | 1482 | kthread_stop(btp->bt_task); |
f0e2d93c | 1483 | kmem_free(btp); |
1da177e4 LT |
1484 | } |
1485 | ||
1da177e4 LT |
1486 | STATIC int |
1487 | xfs_setsize_buftarg_flags( | |
1488 | xfs_buftarg_t *btp, | |
1489 | unsigned int blocksize, | |
1490 | unsigned int sectorsize, | |
1491 | int verbose) | |
1492 | { | |
ce8e922c NS |
1493 | btp->bt_bsize = blocksize; |
1494 | btp->bt_sshift = ffs(sectorsize) - 1; | |
1495 | btp->bt_smask = sectorsize - 1; | |
1da177e4 | 1496 | |
ce8e922c | 1497 | if (set_blocksize(btp->bt_bdev, sectorsize)) { |
4f10700a DC |
1498 | xfs_warn(btp->bt_mount, |
1499 | "Cannot set_blocksize to %u on device %s\n", | |
1da177e4 LT |
1500 | sectorsize, XFS_BUFTARG_NAME(btp)); |
1501 | return EINVAL; | |
1502 | } | |
1503 | ||
1da177e4 LT |
1504 | return 0; |
1505 | } | |
1506 | ||
1507 | /* | |
ce8e922c NS |
1508 | * When allocating the initial buffer target we have not yet |
1509 | * read in the superblock, so don't know what sized sectors | |
1510 | * are being used is at this early stage. Play safe. | |
1511 | */ | |
1da177e4 LT |
1512 | STATIC int |
1513 | xfs_setsize_buftarg_early( | |
1514 | xfs_buftarg_t *btp, | |
1515 | struct block_device *bdev) | |
1516 | { | |
1517 | return xfs_setsize_buftarg_flags(btp, | |
0e6e847f | 1518 | PAGE_SIZE, bdev_logical_block_size(bdev), 0); |
1da177e4 LT |
1519 | } |
1520 | ||
1521 | int | |
1522 | xfs_setsize_buftarg( | |
1523 | xfs_buftarg_t *btp, | |
1524 | unsigned int blocksize, | |
1525 | unsigned int sectorsize) | |
1526 | { | |
1527 | return xfs_setsize_buftarg_flags(btp, blocksize, sectorsize, 1); | |
1528 | } | |
1529 | ||
a6867a68 DC |
1530 | STATIC int |
1531 | xfs_alloc_delwrite_queue( | |
e2a07812 JE |
1532 | xfs_buftarg_t *btp, |
1533 | const char *fsname) | |
a6867a68 | 1534 | { |
a6867a68 | 1535 | INIT_LIST_HEAD(&btp->bt_delwrite_queue); |
007c61c6 | 1536 | spin_lock_init(&btp->bt_delwrite_lock); |
a6867a68 | 1537 | btp->bt_flags = 0; |
e2a07812 | 1538 | btp->bt_task = kthread_run(xfsbufd, btp, "xfsbufd/%s", fsname); |
ff57ab21 DC |
1539 | if (IS_ERR(btp->bt_task)) |
1540 | return PTR_ERR(btp->bt_task); | |
1541 | return 0; | |
a6867a68 DC |
1542 | } |
1543 | ||
1da177e4 LT |
1544 | xfs_buftarg_t * |
1545 | xfs_alloc_buftarg( | |
ebad861b | 1546 | struct xfs_mount *mp, |
1da177e4 | 1547 | struct block_device *bdev, |
e2a07812 JE |
1548 | int external, |
1549 | const char *fsname) | |
1da177e4 LT |
1550 | { |
1551 | xfs_buftarg_t *btp; | |
1552 | ||
1553 | btp = kmem_zalloc(sizeof(*btp), KM_SLEEP); | |
1554 | ||
ebad861b | 1555 | btp->bt_mount = mp; |
ce8e922c NS |
1556 | btp->bt_dev = bdev->bd_dev; |
1557 | btp->bt_bdev = bdev; | |
0e6e847f DC |
1558 | btp->bt_bdi = blk_get_backing_dev_info(bdev); |
1559 | if (!btp->bt_bdi) | |
1560 | goto error; | |
1561 | ||
430cbeb8 DC |
1562 | INIT_LIST_HEAD(&btp->bt_lru); |
1563 | spin_lock_init(&btp->bt_lru_lock); | |
1da177e4 LT |
1564 | if (xfs_setsize_buftarg_early(btp, bdev)) |
1565 | goto error; | |
e2a07812 | 1566 | if (xfs_alloc_delwrite_queue(btp, fsname)) |
a6867a68 | 1567 | goto error; |
ff57ab21 DC |
1568 | btp->bt_shrinker.shrink = xfs_buftarg_shrink; |
1569 | btp->bt_shrinker.seeks = DEFAULT_SEEKS; | |
1570 | register_shrinker(&btp->bt_shrinker); | |
1da177e4 LT |
1571 | return btp; |
1572 | ||
1573 | error: | |
f0e2d93c | 1574 | kmem_free(btp); |
1da177e4 LT |
1575 | return NULL; |
1576 | } | |
1577 | ||
1578 | ||
1579 | /* | |
ce8e922c | 1580 | * Delayed write buffer handling |
1da177e4 | 1581 | */ |
1da177e4 | 1582 | STATIC void |
ce8e922c NS |
1583 | xfs_buf_delwri_queue( |
1584 | xfs_buf_t *bp, | |
1da177e4 LT |
1585 | int unlock) |
1586 | { | |
ce8e922c NS |
1587 | struct list_head *dwq = &bp->b_target->bt_delwrite_queue; |
1588 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; | |
a6867a68 | 1589 | |
0b1b213f CH |
1590 | trace_xfs_buf_delwri_queue(bp, _RET_IP_); |
1591 | ||
ce8e922c | 1592 | ASSERT((bp->b_flags&(XBF_DELWRI|XBF_ASYNC)) == (XBF_DELWRI|XBF_ASYNC)); |
1da177e4 | 1593 | |
a6867a68 | 1594 | spin_lock(dwlk); |
1da177e4 | 1595 | /* If already in the queue, dequeue and place at tail */ |
ce8e922c NS |
1596 | if (!list_empty(&bp->b_list)) { |
1597 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1598 | if (unlock) | |
1599 | atomic_dec(&bp->b_hold); | |
1600 | list_del(&bp->b_list); | |
1da177e4 LT |
1601 | } |
1602 | ||
c9c12971 DC |
1603 | if (list_empty(dwq)) { |
1604 | /* start xfsbufd as it is about to have something to do */ | |
1605 | wake_up_process(bp->b_target->bt_task); | |
1606 | } | |
1607 | ||
ce8e922c NS |
1608 | bp->b_flags |= _XBF_DELWRI_Q; |
1609 | list_add_tail(&bp->b_list, dwq); | |
1610 | bp->b_queuetime = jiffies; | |
a6867a68 | 1611 | spin_unlock(dwlk); |
1da177e4 LT |
1612 | |
1613 | if (unlock) | |
ce8e922c | 1614 | xfs_buf_unlock(bp); |
1da177e4 LT |
1615 | } |
1616 | ||
1617 | void | |
ce8e922c NS |
1618 | xfs_buf_delwri_dequeue( |
1619 | xfs_buf_t *bp) | |
1da177e4 | 1620 | { |
ce8e922c | 1621 | spinlock_t *dwlk = &bp->b_target->bt_delwrite_lock; |
1da177e4 LT |
1622 | int dequeued = 0; |
1623 | ||
a6867a68 | 1624 | spin_lock(dwlk); |
ce8e922c NS |
1625 | if ((bp->b_flags & XBF_DELWRI) && !list_empty(&bp->b_list)) { |
1626 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1627 | list_del_init(&bp->b_list); | |
1da177e4 LT |
1628 | dequeued = 1; |
1629 | } | |
ce8e922c | 1630 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q); |
a6867a68 | 1631 | spin_unlock(dwlk); |
1da177e4 LT |
1632 | |
1633 | if (dequeued) | |
ce8e922c | 1634 | xfs_buf_rele(bp); |
1da177e4 | 1635 | |
0b1b213f | 1636 | trace_xfs_buf_delwri_dequeue(bp, _RET_IP_); |
1da177e4 LT |
1637 | } |
1638 | ||
d808f617 DC |
1639 | /* |
1640 | * If a delwri buffer needs to be pushed before it has aged out, then promote | |
1641 | * it to the head of the delwri queue so that it will be flushed on the next | |
1642 | * xfsbufd run. We do this by resetting the queuetime of the buffer to be older | |
1643 | * than the age currently needed to flush the buffer. Hence the next time the | |
1644 | * xfsbufd sees it is guaranteed to be considered old enough to flush. | |
1645 | */ | |
1646 | void | |
1647 | xfs_buf_delwri_promote( | |
1648 | struct xfs_buf *bp) | |
1649 | { | |
1650 | struct xfs_buftarg *btp = bp->b_target; | |
1651 | long age = xfs_buf_age_centisecs * msecs_to_jiffies(10) + 1; | |
1652 | ||
1653 | ASSERT(bp->b_flags & XBF_DELWRI); | |
1654 | ASSERT(bp->b_flags & _XBF_DELWRI_Q); | |
1655 | ||
1656 | /* | |
1657 | * Check the buffer age before locking the delayed write queue as we | |
1658 | * don't need to promote buffers that are already past the flush age. | |
1659 | */ | |
1660 | if (bp->b_queuetime < jiffies - age) | |
1661 | return; | |
1662 | bp->b_queuetime = jiffies - age; | |
1663 | spin_lock(&btp->bt_delwrite_lock); | |
1664 | list_move(&bp->b_list, &btp->bt_delwrite_queue); | |
1665 | spin_unlock(&btp->bt_delwrite_lock); | |
1666 | } | |
1667 | ||
1da177e4 | 1668 | STATIC void |
ce8e922c | 1669 | xfs_buf_runall_queues( |
1da177e4 LT |
1670 | struct workqueue_struct *queue) |
1671 | { | |
1672 | flush_workqueue(queue); | |
1673 | } | |
1674 | ||
585e6d88 DC |
1675 | /* |
1676 | * Move as many buffers as specified to the supplied list | |
1677 | * idicating if we skipped any buffers to prevent deadlocks. | |
1678 | */ | |
1679 | STATIC int | |
1680 | xfs_buf_delwri_split( | |
1681 | xfs_buftarg_t *target, | |
1682 | struct list_head *list, | |
5e6a07df | 1683 | unsigned long age) |
585e6d88 DC |
1684 | { |
1685 | xfs_buf_t *bp, *n; | |
1686 | struct list_head *dwq = &target->bt_delwrite_queue; | |
1687 | spinlock_t *dwlk = &target->bt_delwrite_lock; | |
1688 | int skipped = 0; | |
5e6a07df | 1689 | int force; |
585e6d88 | 1690 | |
5e6a07df | 1691 | force = test_and_clear_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
585e6d88 DC |
1692 | INIT_LIST_HEAD(list); |
1693 | spin_lock(dwlk); | |
1694 | list_for_each_entry_safe(bp, n, dwq, b_list) { | |
585e6d88 DC |
1695 | ASSERT(bp->b_flags & XBF_DELWRI); |
1696 | ||
4d16e924 | 1697 | if (!XFS_BUF_ISPINNED(bp) && !xfs_buf_cond_lock(bp)) { |
5e6a07df | 1698 | if (!force && |
585e6d88 DC |
1699 | time_before(jiffies, bp->b_queuetime + age)) { |
1700 | xfs_buf_unlock(bp); | |
1701 | break; | |
1702 | } | |
1703 | ||
1704 | bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q| | |
1705 | _XBF_RUN_QUEUES); | |
1706 | bp->b_flags |= XBF_WRITE; | |
1707 | list_move_tail(&bp->b_list, list); | |
bfe27419 | 1708 | trace_xfs_buf_delwri_split(bp, _RET_IP_); |
585e6d88 DC |
1709 | } else |
1710 | skipped++; | |
1711 | } | |
1712 | spin_unlock(dwlk); | |
1713 | ||
1714 | return skipped; | |
1715 | ||
1716 | } | |
1717 | ||
089716aa DC |
1718 | /* |
1719 | * Compare function is more complex than it needs to be because | |
1720 | * the return value is only 32 bits and we are doing comparisons | |
1721 | * on 64 bit values | |
1722 | */ | |
1723 | static int | |
1724 | xfs_buf_cmp( | |
1725 | void *priv, | |
1726 | struct list_head *a, | |
1727 | struct list_head *b) | |
1728 | { | |
1729 | struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list); | |
1730 | struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); | |
1731 | xfs_daddr_t diff; | |
1732 | ||
1733 | diff = ap->b_bn - bp->b_bn; | |
1734 | if (diff < 0) | |
1735 | return -1; | |
1736 | if (diff > 0) | |
1737 | return 1; | |
1738 | return 0; | |
1739 | } | |
1740 | ||
1741 | void | |
1742 | xfs_buf_delwri_sort( | |
1743 | xfs_buftarg_t *target, | |
1744 | struct list_head *list) | |
1745 | { | |
1746 | list_sort(NULL, list, xfs_buf_cmp); | |
1747 | } | |
1748 | ||
1da177e4 | 1749 | STATIC int |
23ea4032 | 1750 | xfsbufd( |
585e6d88 | 1751 | void *data) |
1da177e4 | 1752 | { |
089716aa | 1753 | xfs_buftarg_t *target = (xfs_buftarg_t *)data; |
1da177e4 | 1754 | |
1da177e4 LT |
1755 | current->flags |= PF_MEMALLOC; |
1756 | ||
978c7b2f RW |
1757 | set_freezable(); |
1758 | ||
1da177e4 | 1759 | do { |
c9c12971 DC |
1760 | long age = xfs_buf_age_centisecs * msecs_to_jiffies(10); |
1761 | long tout = xfs_buf_timer_centisecs * msecs_to_jiffies(10); | |
089716aa | 1762 | struct list_head tmp; |
a1b7ea5d | 1763 | struct blk_plug plug; |
c9c12971 | 1764 | |
3e1d1d28 | 1765 | if (unlikely(freezing(current))) { |
ce8e922c | 1766 | set_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
3e1d1d28 | 1767 | refrigerator(); |
abd0cf7a | 1768 | } else { |
ce8e922c | 1769 | clear_bit(XBT_FORCE_SLEEP, &target->bt_flags); |
abd0cf7a | 1770 | } |
1da177e4 | 1771 | |
c9c12971 DC |
1772 | /* sleep for a long time if there is nothing to do. */ |
1773 | if (list_empty(&target->bt_delwrite_queue)) | |
1774 | tout = MAX_SCHEDULE_TIMEOUT; | |
1775 | schedule_timeout_interruptible(tout); | |
1da177e4 | 1776 | |
c9c12971 | 1777 | xfs_buf_delwri_split(target, &tmp, age); |
089716aa | 1778 | list_sort(NULL, &tmp, xfs_buf_cmp); |
a1b7ea5d CH |
1779 | |
1780 | blk_start_plug(&plug); | |
1da177e4 | 1781 | while (!list_empty(&tmp)) { |
089716aa DC |
1782 | struct xfs_buf *bp; |
1783 | bp = list_first_entry(&tmp, struct xfs_buf, b_list); | |
ce8e922c | 1784 | list_del_init(&bp->b_list); |
939d723b | 1785 | xfs_bdstrat_cb(bp); |
1da177e4 | 1786 | } |
a1b7ea5d | 1787 | blk_finish_plug(&plug); |
4df08c52 | 1788 | } while (!kthread_should_stop()); |
1da177e4 | 1789 | |
4df08c52 | 1790 | return 0; |
1da177e4 LT |
1791 | } |
1792 | ||
1793 | /* | |
ce8e922c NS |
1794 | * Go through all incore buffers, and release buffers if they belong to |
1795 | * the given device. This is used in filesystem error handling to | |
1796 | * preserve the consistency of its metadata. | |
1da177e4 LT |
1797 | */ |
1798 | int | |
1799 | xfs_flush_buftarg( | |
585e6d88 DC |
1800 | xfs_buftarg_t *target, |
1801 | int wait) | |
1da177e4 | 1802 | { |
089716aa | 1803 | xfs_buf_t *bp; |
585e6d88 | 1804 | int pincount = 0; |
089716aa DC |
1805 | LIST_HEAD(tmp_list); |
1806 | LIST_HEAD(wait_list); | |
a1b7ea5d | 1807 | struct blk_plug plug; |
1da177e4 | 1808 | |
c626d174 | 1809 | xfs_buf_runall_queues(xfsconvertd_workqueue); |
ce8e922c NS |
1810 | xfs_buf_runall_queues(xfsdatad_workqueue); |
1811 | xfs_buf_runall_queues(xfslogd_workqueue); | |
1da177e4 | 1812 | |
5e6a07df | 1813 | set_bit(XBT_FORCE_FLUSH, &target->bt_flags); |
089716aa | 1814 | pincount = xfs_buf_delwri_split(target, &tmp_list, 0); |
1da177e4 LT |
1815 | |
1816 | /* | |
089716aa DC |
1817 | * Dropped the delayed write list lock, now walk the temporary list. |
1818 | * All I/O is issued async and then if we need to wait for completion | |
1819 | * we do that after issuing all the IO. | |
1da177e4 | 1820 | */ |
089716aa | 1821 | list_sort(NULL, &tmp_list, xfs_buf_cmp); |
a1b7ea5d CH |
1822 | |
1823 | blk_start_plug(&plug); | |
089716aa DC |
1824 | while (!list_empty(&tmp_list)) { |
1825 | bp = list_first_entry(&tmp_list, struct xfs_buf, b_list); | |
585e6d88 | 1826 | ASSERT(target == bp->b_target); |
089716aa DC |
1827 | list_del_init(&bp->b_list); |
1828 | if (wait) { | |
ce8e922c | 1829 | bp->b_flags &= ~XBF_ASYNC; |
089716aa DC |
1830 | list_add(&bp->b_list, &wait_list); |
1831 | } | |
939d723b | 1832 | xfs_bdstrat_cb(bp); |
1da177e4 | 1833 | } |
a1b7ea5d | 1834 | blk_finish_plug(&plug); |
1da177e4 | 1835 | |
089716aa | 1836 | if (wait) { |
a1b7ea5d | 1837 | /* Wait for IO to complete. */ |
089716aa DC |
1838 | while (!list_empty(&wait_list)) { |
1839 | bp = list_first_entry(&wait_list, struct xfs_buf, b_list); | |
f07c2250 | 1840 | |
089716aa | 1841 | list_del_init(&bp->b_list); |
1a1a3e97 | 1842 | xfs_buf_iowait(bp); |
089716aa DC |
1843 | xfs_buf_relse(bp); |
1844 | } | |
1da177e4 LT |
1845 | } |
1846 | ||
1da177e4 LT |
1847 | return pincount; |
1848 | } | |
1849 | ||
04d8b284 | 1850 | int __init |
ce8e922c | 1851 | xfs_buf_init(void) |
1da177e4 | 1852 | { |
8758280f NS |
1853 | xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf", |
1854 | KM_ZONE_HWALIGN, NULL); | |
ce8e922c | 1855 | if (!xfs_buf_zone) |
0b1b213f | 1856 | goto out; |
04d8b284 | 1857 | |
51749e47 | 1858 | xfslogd_workqueue = alloc_workqueue("xfslogd", |
6370a6ad | 1859 | WQ_MEM_RECLAIM | WQ_HIGHPRI, 1); |
23ea4032 | 1860 | if (!xfslogd_workqueue) |
04d8b284 | 1861 | goto out_free_buf_zone; |
1da177e4 | 1862 | |
83e75904 | 1863 | xfsdatad_workqueue = alloc_workqueue("xfsdatad", WQ_MEM_RECLAIM, 1); |
23ea4032 CH |
1864 | if (!xfsdatad_workqueue) |
1865 | goto out_destroy_xfslogd_workqueue; | |
1da177e4 | 1866 | |
83e75904 TH |
1867 | xfsconvertd_workqueue = alloc_workqueue("xfsconvertd", |
1868 | WQ_MEM_RECLAIM, 1); | |
c626d174 DC |
1869 | if (!xfsconvertd_workqueue) |
1870 | goto out_destroy_xfsdatad_workqueue; | |
1871 | ||
23ea4032 | 1872 | return 0; |
1da177e4 | 1873 | |
c626d174 DC |
1874 | out_destroy_xfsdatad_workqueue: |
1875 | destroy_workqueue(xfsdatad_workqueue); | |
23ea4032 CH |
1876 | out_destroy_xfslogd_workqueue: |
1877 | destroy_workqueue(xfslogd_workqueue); | |
23ea4032 | 1878 | out_free_buf_zone: |
ce8e922c | 1879 | kmem_zone_destroy(xfs_buf_zone); |
0b1b213f | 1880 | out: |
8758280f | 1881 | return -ENOMEM; |
1da177e4 LT |
1882 | } |
1883 | ||
1da177e4 | 1884 | void |
ce8e922c | 1885 | xfs_buf_terminate(void) |
1da177e4 | 1886 | { |
c626d174 | 1887 | destroy_workqueue(xfsconvertd_workqueue); |
04d8b284 CH |
1888 | destroy_workqueue(xfsdatad_workqueue); |
1889 | destroy_workqueue(xfslogd_workqueue); | |
ce8e922c | 1890 | kmem_zone_destroy(xfs_buf_zone); |
1da177e4 | 1891 | } |
e6a0e9cd TS |
1892 | |
1893 | #ifdef CONFIG_KDB_MODULES | |
1894 | struct list_head * | |
1895 | xfs_get_buftarg_list(void) | |
1896 | { | |
1897 | return &xfs_buftarg_list; | |
1898 | } | |
1899 | #endif |