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1da177e4 | 1 | /* |
7b718769 | 2 | * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. |
c7e8f268 | 3 | * Copyright (c) 2008 Dave Chinner |
7b718769 | 4 | * All Rights Reserved. |
1da177e4 | 5 | * |
7b718769 NS |
6 | * This program is free software; you can redistribute it and/or |
7 | * modify it under the terms of the GNU General Public License as | |
1da177e4 LT |
8 | * published by the Free Software Foundation. |
9 | * | |
7b718769 NS |
10 | * This program is distributed in the hope that it would be useful, |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
1da177e4 | 14 | * |
7b718769 NS |
15 | * You should have received a copy of the GNU General Public License |
16 | * along with this program; if not, write the Free Software Foundation, | |
17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
1da177e4 | 18 | */ |
1da177e4 | 19 | #include "xfs.h" |
a844f451 | 20 | #include "xfs_fs.h" |
4fb6e8ad | 21 | #include "xfs_format.h" |
239880ef DC |
22 | #include "xfs_log_format.h" |
23 | #include "xfs_trans_resv.h" | |
1da177e4 | 24 | #include "xfs_mount.h" |
239880ef | 25 | #include "xfs_trans.h" |
1da177e4 | 26 | #include "xfs_trans_priv.h" |
9e4c109a | 27 | #include "xfs_trace.h" |
e9e899a2 | 28 | #include "xfs_errortag.h" |
1da177e4 | 29 | #include "xfs_error.h" |
239880ef | 30 | #include "xfs_log.h" |
1da177e4 | 31 | |
1da177e4 | 32 | #ifdef DEBUG |
cd4a3c50 DC |
33 | /* |
34 | * Check that the list is sorted as it should be. | |
35 | */ | |
36 | STATIC void | |
37 | xfs_ail_check( | |
38 | struct xfs_ail *ailp, | |
39 | xfs_log_item_t *lip) | |
40 | { | |
41 | xfs_log_item_t *prev_lip; | |
42 | ||
43 | if (list_empty(&ailp->xa_ail)) | |
44 | return; | |
45 | ||
46 | /* | |
47 | * Check the next and previous entries are valid. | |
48 | */ | |
49 | ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0); | |
50 | prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail); | |
51 | if (&prev_lip->li_ail != &ailp->xa_ail) | |
52 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0); | |
53 | ||
54 | prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail); | |
55 | if (&prev_lip->li_ail != &ailp->xa_ail) | |
56 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0); | |
57 | ||
58 | ||
cd4a3c50 DC |
59 | } |
60 | #else /* !DEBUG */ | |
de08dbc1 | 61 | #define xfs_ail_check(a,l) |
1da177e4 LT |
62 | #endif /* DEBUG */ |
63 | ||
cd4a3c50 | 64 | /* |
fd074841 DC |
65 | * Return a pointer to the last item in the AIL. If the AIL is empty, then |
66 | * return NULL. | |
67 | */ | |
68 | static xfs_log_item_t * | |
69 | xfs_ail_max( | |
70 | struct xfs_ail *ailp) | |
71 | { | |
72 | if (list_empty(&ailp->xa_ail)) | |
73 | return NULL; | |
74 | ||
75 | return list_entry(ailp->xa_ail.prev, xfs_log_item_t, li_ail); | |
76 | } | |
77 | ||
cd4a3c50 DC |
78 | /* |
79 | * Return a pointer to the item which follows the given item in the AIL. If | |
80 | * the given item is the last item in the list, then return NULL. | |
81 | */ | |
82 | static xfs_log_item_t * | |
83 | xfs_ail_next( | |
84 | struct xfs_ail *ailp, | |
85 | xfs_log_item_t *lip) | |
86 | { | |
87 | if (lip->li_ail.next == &ailp->xa_ail) | |
88 | return NULL; | |
89 | ||
90 | return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail); | |
91 | } | |
1da177e4 LT |
92 | |
93 | /* | |
cd4a3c50 DC |
94 | * This is called by the log manager code to determine the LSN of the tail of |
95 | * the log. This is exactly the LSN of the first item in the AIL. If the AIL | |
96 | * is empty, then this function returns 0. | |
1da177e4 | 97 | * |
cd4a3c50 DC |
98 | * We need the AIL lock in order to get a coherent read of the lsn of the last |
99 | * item in the AIL. | |
1da177e4 LT |
100 | */ |
101 | xfs_lsn_t | |
fd074841 | 102 | xfs_ail_min_lsn( |
5b00f14f | 103 | struct xfs_ail *ailp) |
1da177e4 | 104 | { |
cd4a3c50 | 105 | xfs_lsn_t lsn = 0; |
1da177e4 | 106 | xfs_log_item_t *lip; |
1da177e4 | 107 | |
c7e8f268 | 108 | spin_lock(&ailp->xa_lock); |
5b00f14f | 109 | lip = xfs_ail_min(ailp); |
cd4a3c50 | 110 | if (lip) |
1da177e4 | 111 | lsn = lip->li_lsn; |
c7e8f268 | 112 | spin_unlock(&ailp->xa_lock); |
1da177e4 LT |
113 | |
114 | return lsn; | |
115 | } | |
116 | ||
fd074841 DC |
117 | /* |
118 | * Return the maximum lsn held in the AIL, or zero if the AIL is empty. | |
119 | */ | |
120 | static xfs_lsn_t | |
121 | xfs_ail_max_lsn( | |
122 | struct xfs_ail *ailp) | |
123 | { | |
124 | xfs_lsn_t lsn = 0; | |
125 | xfs_log_item_t *lip; | |
126 | ||
127 | spin_lock(&ailp->xa_lock); | |
128 | lip = xfs_ail_max(ailp); | |
129 | if (lip) | |
130 | lsn = lip->li_lsn; | |
131 | spin_unlock(&ailp->xa_lock); | |
132 | ||
133 | return lsn; | |
134 | } | |
135 | ||
27d8d5fe | 136 | /* |
af3e4022 DC |
137 | * The cursor keeps track of where our current traversal is up to by tracking |
138 | * the next item in the list for us. However, for this to be safe, removing an | |
139 | * object from the AIL needs to invalidate any cursor that points to it. hence | |
140 | * the traversal cursor needs to be linked to the struct xfs_ail so that | |
141 | * deletion can search all the active cursors for invalidation. | |
27d8d5fe | 142 | */ |
5b00f14f | 143 | STATIC void |
27d8d5fe DC |
144 | xfs_trans_ail_cursor_init( |
145 | struct xfs_ail *ailp, | |
146 | struct xfs_ail_cursor *cur) | |
147 | { | |
148 | cur->item = NULL; | |
af3e4022 | 149 | list_add_tail(&cur->list, &ailp->xa_cursors); |
27d8d5fe DC |
150 | } |
151 | ||
27d8d5fe | 152 | /* |
af3e4022 DC |
153 | * Get the next item in the traversal and advance the cursor. If the cursor |
154 | * was invalidated (indicated by a lip of 1), restart the traversal. | |
27d8d5fe | 155 | */ |
5b00f14f | 156 | struct xfs_log_item * |
27d8d5fe DC |
157 | xfs_trans_ail_cursor_next( |
158 | struct xfs_ail *ailp, | |
159 | struct xfs_ail_cursor *cur) | |
160 | { | |
161 | struct xfs_log_item *lip = cur->item; | |
162 | ||
db9d67d6 | 163 | if ((uintptr_t)lip & 1) |
27d8d5fe | 164 | lip = xfs_ail_min(ailp); |
16b59029 DC |
165 | if (lip) |
166 | cur->item = xfs_ail_next(ailp, lip); | |
27d8d5fe DC |
167 | return lip; |
168 | } | |
169 | ||
27d8d5fe | 170 | /* |
af3e4022 DC |
171 | * When the traversal is complete, we need to remove the cursor from the list |
172 | * of traversing cursors. | |
27d8d5fe DC |
173 | */ |
174 | void | |
175 | xfs_trans_ail_cursor_done( | |
af3e4022 | 176 | struct xfs_ail_cursor *cur) |
27d8d5fe | 177 | { |
af3e4022 DC |
178 | cur->item = NULL; |
179 | list_del_init(&cur->list); | |
27d8d5fe DC |
180 | } |
181 | ||
5b00f14f | 182 | /* |
af3e4022 DC |
183 | * Invalidate any cursor that is pointing to this item. This is called when an |
184 | * item is removed from the AIL. Any cursor pointing to this object is now | |
185 | * invalid and the traversal needs to be terminated so it doesn't reference a | |
186 | * freed object. We set the low bit of the cursor item pointer so we can | |
187 | * distinguish between an invalidation and the end of the list when getting the | |
188 | * next item from the cursor. | |
5b00f14f DC |
189 | */ |
190 | STATIC void | |
191 | xfs_trans_ail_cursor_clear( | |
192 | struct xfs_ail *ailp, | |
193 | struct xfs_log_item *lip) | |
194 | { | |
195 | struct xfs_ail_cursor *cur; | |
196 | ||
af3e4022 | 197 | list_for_each_entry(cur, &ailp->xa_cursors, list) { |
5b00f14f DC |
198 | if (cur->item == lip) |
199 | cur->item = (struct xfs_log_item *) | |
db9d67d6 | 200 | ((uintptr_t)cur->item | 1); |
5b00f14f DC |
201 | } |
202 | } | |
203 | ||
249a8c11 | 204 | /* |
16b59029 DC |
205 | * Find the first item in the AIL with the given @lsn by searching in ascending |
206 | * LSN order and initialise the cursor to point to the next item for a | |
207 | * ascending traversal. Pass a @lsn of zero to initialise the cursor to the | |
208 | * first item in the AIL. Returns NULL if the list is empty. | |
249a8c11 | 209 | */ |
5b00f14f DC |
210 | xfs_log_item_t * |
211 | xfs_trans_ail_cursor_first( | |
27d8d5fe DC |
212 | struct xfs_ail *ailp, |
213 | struct xfs_ail_cursor *cur, | |
214 | xfs_lsn_t lsn) | |
249a8c11 | 215 | { |
27d8d5fe | 216 | xfs_log_item_t *lip; |
249a8c11 | 217 | |
5b00f14f | 218 | xfs_trans_ail_cursor_init(ailp, cur); |
16b59029 DC |
219 | |
220 | if (lsn == 0) { | |
221 | lip = xfs_ail_min(ailp); | |
5b00f14f | 222 | goto out; |
16b59029 | 223 | } |
249a8c11 | 224 | |
27d8d5fe | 225 | list_for_each_entry(lip, &ailp->xa_ail, li_ail) { |
5b00f14f | 226 | if (XFS_LSN_CMP(lip->li_lsn, lsn) >= 0) |
7ee49acf | 227 | goto out; |
535f6b37 | 228 | } |
16b59029 DC |
229 | return NULL; |
230 | ||
5b00f14f | 231 | out: |
16b59029 DC |
232 | if (lip) |
233 | cur->item = xfs_ail_next(ailp, lip); | |
5b00f14f | 234 | return lip; |
249a8c11 DC |
235 | } |
236 | ||
1d8c95a3 DC |
237 | static struct xfs_log_item * |
238 | __xfs_trans_ail_cursor_last( | |
239 | struct xfs_ail *ailp, | |
240 | xfs_lsn_t lsn) | |
241 | { | |
242 | xfs_log_item_t *lip; | |
243 | ||
244 | list_for_each_entry_reverse(lip, &ailp->xa_ail, li_ail) { | |
245 | if (XFS_LSN_CMP(lip->li_lsn, lsn) <= 0) | |
246 | return lip; | |
247 | } | |
248 | return NULL; | |
249 | } | |
250 | ||
251 | /* | |
16b59029 DC |
252 | * Find the last item in the AIL with the given @lsn by searching in descending |
253 | * LSN order and initialise the cursor to point to that item. If there is no | |
254 | * item with the value of @lsn, then it sets the cursor to the last item with an | |
255 | * LSN lower than @lsn. Returns NULL if the list is empty. | |
1d8c95a3 DC |
256 | */ |
257 | struct xfs_log_item * | |
258 | xfs_trans_ail_cursor_last( | |
259 | struct xfs_ail *ailp, | |
260 | struct xfs_ail_cursor *cur, | |
261 | xfs_lsn_t lsn) | |
262 | { | |
263 | xfs_trans_ail_cursor_init(ailp, cur); | |
264 | cur->item = __xfs_trans_ail_cursor_last(ailp, lsn); | |
265 | return cur->item; | |
266 | } | |
267 | ||
268 | /* | |
16b59029 | 269 | * Splice the log item list into the AIL at the given LSN. We splice to the |
1d8c95a3 DC |
270 | * tail of the given LSN to maintain insert order for push traversals. The |
271 | * cursor is optional, allowing repeated updates to the same LSN to avoid | |
e44f4112 | 272 | * repeated traversals. This should not be called with an empty list. |
cd4a3c50 DC |
273 | */ |
274 | static void | |
275 | xfs_ail_splice( | |
1d8c95a3 DC |
276 | struct xfs_ail *ailp, |
277 | struct xfs_ail_cursor *cur, | |
278 | struct list_head *list, | |
279 | xfs_lsn_t lsn) | |
cd4a3c50 | 280 | { |
e44f4112 AE |
281 | struct xfs_log_item *lip; |
282 | ||
283 | ASSERT(!list_empty(list)); | |
cd4a3c50 | 284 | |
1d8c95a3 | 285 | /* |
e44f4112 AE |
286 | * Use the cursor to determine the insertion point if one is |
287 | * provided. If not, or if the one we got is not valid, | |
288 | * find the place in the AIL where the items belong. | |
1d8c95a3 | 289 | */ |
e44f4112 | 290 | lip = cur ? cur->item : NULL; |
db9d67d6 | 291 | if (!lip || (uintptr_t)lip & 1) |
1d8c95a3 DC |
292 | lip = __xfs_trans_ail_cursor_last(ailp, lsn); |
293 | ||
e44f4112 AE |
294 | /* |
295 | * If a cursor is provided, we know we're processing the AIL | |
296 | * in lsn order, and future items to be spliced in will | |
297 | * follow the last one being inserted now. Update the | |
298 | * cursor to point to that last item, now while we have a | |
299 | * reliable pointer to it. | |
300 | */ | |
301 | if (cur) | |
302 | cur->item = list_entry(list->prev, struct xfs_log_item, li_ail); | |
cd4a3c50 | 303 | |
1d8c95a3 | 304 | /* |
e44f4112 AE |
305 | * Finally perform the splice. Unless the AIL was empty, |
306 | * lip points to the item in the AIL _after_ which the new | |
307 | * items should go. If lip is null the AIL was empty, so | |
308 | * the new items go at the head of the AIL. | |
1d8c95a3 | 309 | */ |
e44f4112 AE |
310 | if (lip) |
311 | list_splice(list, &lip->li_ail); | |
312 | else | |
313 | list_splice(list, &ailp->xa_ail); | |
cd4a3c50 DC |
314 | } |
315 | ||
316 | /* | |
317 | * Delete the given item from the AIL. Return a pointer to the item. | |
318 | */ | |
319 | static void | |
320 | xfs_ail_delete( | |
321 | struct xfs_ail *ailp, | |
322 | xfs_log_item_t *lip) | |
323 | { | |
324 | xfs_ail_check(ailp, lip); | |
325 | list_del(&lip->li_ail); | |
326 | xfs_trans_ail_cursor_clear(ailp, lip); | |
327 | } | |
328 | ||
7f4d01f3 BF |
329 | static inline uint |
330 | xfsaild_push_item( | |
331 | struct xfs_ail *ailp, | |
332 | struct xfs_log_item *lip) | |
333 | { | |
334 | /* | |
335 | * If log item pinning is enabled, skip the push and track the item as | |
336 | * pinned. This can help induce head-behind-tail conditions. | |
337 | */ | |
338 | if (XFS_TEST_ERROR(false, ailp->xa_mount, XFS_ERRTAG_LOG_ITEM_PIN)) | |
339 | return XFS_ITEM_PINNED; | |
340 | ||
341 | return lip->li_ops->iop_push(lip, &ailp->xa_buf_list); | |
342 | } | |
343 | ||
0030807c CH |
344 | static long |
345 | xfsaild_push( | |
346 | struct xfs_ail *ailp) | |
249a8c11 | 347 | { |
9e7004e7 | 348 | xfs_mount_t *mp = ailp->xa_mount; |
af3e4022 | 349 | struct xfs_ail_cursor cur; |
9e7004e7 DC |
350 | xfs_log_item_t *lip; |
351 | xfs_lsn_t lsn; | |
fe0da767 | 352 | xfs_lsn_t target; |
43ff2122 | 353 | long tout; |
9e7004e7 | 354 | int stuck = 0; |
43ff2122 | 355 | int flushing = 0; |
9e7004e7 | 356 | int count = 0; |
1da177e4 | 357 | |
670ce93f | 358 | /* |
43ff2122 CH |
359 | * If we encountered pinned items or did not finish writing out all |
360 | * buffers the last time we ran, force the log first and wait for it | |
361 | * before pushing again. | |
670ce93f | 362 | */ |
43ff2122 CH |
363 | if (ailp->xa_log_flush && ailp->xa_last_pushed_lsn == 0 && |
364 | (!list_empty_careful(&ailp->xa_buf_list) || | |
365 | xfs_ail_min_lsn(ailp))) { | |
670ce93f | 366 | ailp->xa_log_flush = 0; |
43ff2122 | 367 | |
ff6d6af2 | 368 | XFS_STATS_INC(mp, xs_push_ail_flush); |
670ce93f | 369 | xfs_log_force(mp, XFS_LOG_SYNC); |
670ce93f DC |
370 | } |
371 | ||
43ff2122 | 372 | spin_lock(&ailp->xa_lock); |
8375f922 BF |
373 | |
374 | /* barrier matches the xa_target update in xfs_ail_push() */ | |
375 | smp_rmb(); | |
376 | target = ailp->xa_target; | |
377 | ailp->xa_target_prev = target; | |
378 | ||
af3e4022 | 379 | lip = xfs_trans_ail_cursor_first(ailp, &cur, ailp->xa_last_pushed_lsn); |
211e4d43 | 380 | if (!lip) { |
1da177e4 | 381 | /* |
43ff2122 CH |
382 | * If the AIL is empty or our push has reached the end we are |
383 | * done now. | |
1da177e4 | 384 | */ |
e4a1e29c | 385 | xfs_trans_ail_cursor_done(&cur); |
c7e8f268 | 386 | spin_unlock(&ailp->xa_lock); |
9e7004e7 | 387 | goto out_done; |
1da177e4 LT |
388 | } |
389 | ||
ff6d6af2 | 390 | XFS_STATS_INC(mp, xs_push_ail); |
1da177e4 | 391 | |
249a8c11 | 392 | lsn = lip->li_lsn; |
50e86686 | 393 | while ((XFS_LSN_CMP(lip->li_lsn, target) <= 0)) { |
249a8c11 | 394 | int lock_result; |
43ff2122 | 395 | |
1da177e4 | 396 | /* |
904c17e6 | 397 | * Note that iop_push may unlock and reacquire the AIL lock. We |
43ff2122 CH |
398 | * rely on the AIL cursor implementation to be able to deal with |
399 | * the dropped lock. | |
1da177e4 | 400 | */ |
7f4d01f3 | 401 | lock_result = xfsaild_push_item(ailp, lip); |
1da177e4 | 402 | switch (lock_result) { |
249a8c11 | 403 | case XFS_ITEM_SUCCESS: |
ff6d6af2 | 404 | XFS_STATS_INC(mp, xs_push_ail_success); |
9e4c109a CH |
405 | trace_xfs_ail_push(lip); |
406 | ||
0bf6a5bd | 407 | ailp->xa_last_pushed_lsn = lsn; |
1da177e4 LT |
408 | break; |
409 | ||
43ff2122 CH |
410 | case XFS_ITEM_FLUSHING: |
411 | /* | |
412 | * The item or its backing buffer is already beeing | |
413 | * flushed. The typical reason for that is that an | |
414 | * inode buffer is locked because we already pushed the | |
415 | * updates to it as part of inode clustering. | |
416 | * | |
417 | * We do not want to to stop flushing just because lots | |
418 | * of items are already beeing flushed, but we need to | |
419 | * re-try the flushing relatively soon if most of the | |
420 | * AIL is beeing flushed. | |
421 | */ | |
ff6d6af2 | 422 | XFS_STATS_INC(mp, xs_push_ail_flushing); |
43ff2122 CH |
423 | trace_xfs_ail_flushing(lip); |
424 | ||
425 | flushing++; | |
426 | ailp->xa_last_pushed_lsn = lsn; | |
1da177e4 LT |
427 | break; |
428 | ||
249a8c11 | 429 | case XFS_ITEM_PINNED: |
ff6d6af2 | 430 | XFS_STATS_INC(mp, xs_push_ail_pinned); |
9e4c109a CH |
431 | trace_xfs_ail_pinned(lip); |
432 | ||
249a8c11 | 433 | stuck++; |
670ce93f | 434 | ailp->xa_log_flush++; |
1da177e4 | 435 | break; |
249a8c11 | 436 | case XFS_ITEM_LOCKED: |
ff6d6af2 | 437 | XFS_STATS_INC(mp, xs_push_ail_locked); |
9e4c109a | 438 | trace_xfs_ail_locked(lip); |
43ff2122 | 439 | |
249a8c11 | 440 | stuck++; |
1da177e4 | 441 | break; |
249a8c11 | 442 | default: |
1da177e4 LT |
443 | ASSERT(0); |
444 | break; | |
445 | } | |
446 | ||
249a8c11 | 447 | count++; |
1da177e4 | 448 | |
249a8c11 DC |
449 | /* |
450 | * Are there too many items we can't do anything with? | |
43ff2122 | 451 | * |
249a8c11 DC |
452 | * If we we are skipping too many items because we can't flush |
453 | * them or they are already being flushed, we back off and | |
454 | * given them time to complete whatever operation is being | |
455 | * done. i.e. remove pressure from the AIL while we can't make | |
456 | * progress so traversals don't slow down further inserts and | |
457 | * removals to/from the AIL. | |
458 | * | |
459 | * The value of 100 is an arbitrary magic number based on | |
460 | * observation. | |
461 | */ | |
462 | if (stuck > 100) | |
463 | break; | |
464 | ||
af3e4022 | 465 | lip = xfs_trans_ail_cursor_next(ailp, &cur); |
249a8c11 DC |
466 | if (lip == NULL) |
467 | break; | |
249a8c11 | 468 | lsn = lip->li_lsn; |
1da177e4 | 469 | } |
e4a1e29c | 470 | xfs_trans_ail_cursor_done(&cur); |
c7e8f268 | 471 | spin_unlock(&ailp->xa_lock); |
1da177e4 | 472 | |
43ff2122 CH |
473 | if (xfs_buf_delwri_submit_nowait(&ailp->xa_buf_list)) |
474 | ailp->xa_log_flush++; | |
d808f617 | 475 | |
43ff2122 | 476 | if (!count || XFS_LSN_CMP(lsn, target) >= 0) { |
9e7004e7 | 477 | out_done: |
92d9cd10 | 478 | /* |
43ff2122 CH |
479 | * We reached the target or the AIL is empty, so wait a bit |
480 | * longer for I/O to complete and remove pushed items from the | |
481 | * AIL before we start the next scan from the start of the AIL. | |
92d9cd10 | 482 | */ |
453eac8a | 483 | tout = 50; |
0bf6a5bd | 484 | ailp->xa_last_pushed_lsn = 0; |
43ff2122 | 485 | } else if (((stuck + flushing) * 100) / count > 90) { |
249a8c11 | 486 | /* |
43ff2122 CH |
487 | * Either there is a lot of contention on the AIL or we are |
488 | * stuck due to operations in progress. "Stuck" in this case | |
489 | * is defined as >90% of the items we tried to push were stuck. | |
249a8c11 DC |
490 | * |
491 | * Backoff a bit more to allow some I/O to complete before | |
43ff2122 CH |
492 | * restarting from the start of the AIL. This prevents us from |
493 | * spinning on the same items, and if they are pinned will all | |
494 | * the restart to issue a log force to unpin the stuck items. | |
249a8c11 | 495 | */ |
453eac8a | 496 | tout = 20; |
670ce93f | 497 | ailp->xa_last_pushed_lsn = 0; |
43ff2122 CH |
498 | } else { |
499 | /* | |
500 | * Assume we have more work to do in a short while. | |
501 | */ | |
502 | tout = 10; | |
1da177e4 | 503 | } |
0bf6a5bd | 504 | |
0030807c CH |
505 | return tout; |
506 | } | |
507 | ||
508 | static int | |
509 | xfsaild( | |
510 | void *data) | |
511 | { | |
512 | struct xfs_ail *ailp = data; | |
513 | long tout = 0; /* milliseconds */ | |
514 | ||
43ff2122 | 515 | current->flags |= PF_MEMALLOC; |
18f1df4e | 516 | set_freezable(); |
43ff2122 | 517 | |
0bd89676 | 518 | while (1) { |
0030807c | 519 | if (tout && tout <= 20) |
0bd89676 | 520 | set_current_state(TASK_KILLABLE); |
0030807c | 521 | else |
0bd89676 HT |
522 | set_current_state(TASK_INTERRUPTIBLE); |
523 | ||
524 | /* | |
525 | * Check kthread_should_stop() after we set the task state | |
526 | * to guarantee that we either see the stop bit and exit or | |
527 | * the task state is reset to runnable such that it's not | |
528 | * scheduled out indefinitely and detects the stop bit at | |
529 | * next iteration. | |
530 | * | |
531 | * A memory barrier is included in above task state set to | |
532 | * serialize again kthread_stop(). | |
533 | */ | |
534 | if (kthread_should_stop()) { | |
535 | __set_current_state(TASK_RUNNING); | |
536 | break; | |
537 | } | |
8375f922 BF |
538 | |
539 | spin_lock(&ailp->xa_lock); | |
540 | ||
541 | /* | |
542 | * Idle if the AIL is empty and we are not racing with a target | |
543 | * update. We check the AIL after we set the task to a sleep | |
544 | * state to guarantee that we either catch an xa_target update | |
545 | * or that a wake_up resets the state to TASK_RUNNING. | |
546 | * Otherwise, we run the risk of sleeping indefinitely. | |
547 | * | |
548 | * The barrier matches the xa_target update in xfs_ail_push(). | |
549 | */ | |
550 | smp_rmb(); | |
551 | if (!xfs_ail_min(ailp) && | |
552 | ailp->xa_target == ailp->xa_target_prev) { | |
553 | spin_unlock(&ailp->xa_lock); | |
18f1df4e | 554 | freezable_schedule(); |
8375f922 BF |
555 | tout = 0; |
556 | continue; | |
557 | } | |
558 | spin_unlock(&ailp->xa_lock); | |
559 | ||
560 | if (tout) | |
18f1df4e | 561 | freezable_schedule_timeout(msecs_to_jiffies(tout)); |
8375f922 BF |
562 | |
563 | __set_current_state(TASK_RUNNING); | |
0030807c CH |
564 | |
565 | try_to_freeze(); | |
566 | ||
567 | tout = xfsaild_push(ailp); | |
568 | } | |
569 | ||
570 | return 0; | |
453eac8a | 571 | } |
1da177e4 | 572 | |
0bf6a5bd DC |
573 | /* |
574 | * This routine is called to move the tail of the AIL forward. It does this by | |
575 | * trying to flush items in the AIL whose lsns are below the given | |
576 | * threshold_lsn. | |
577 | * | |
578 | * The push is run asynchronously in a workqueue, which means the caller needs | |
579 | * to handle waiting on the async flush for space to become available. | |
580 | * We don't want to interrupt any push that is in progress, hence we only queue | |
581 | * work if we set the pushing bit approriately. | |
582 | * | |
583 | * We do this unlocked - we only need to know whether there is anything in the | |
584 | * AIL at the time we are called. We don't need to access the contents of | |
585 | * any of the objects, so the lock is not needed. | |
586 | */ | |
587 | void | |
fd074841 | 588 | xfs_ail_push( |
0bf6a5bd DC |
589 | struct xfs_ail *ailp, |
590 | xfs_lsn_t threshold_lsn) | |
591 | { | |
592 | xfs_log_item_t *lip; | |
593 | ||
594 | lip = xfs_ail_min(ailp); | |
595 | if (!lip || XFS_FORCED_SHUTDOWN(ailp->xa_mount) || | |
596 | XFS_LSN_CMP(threshold_lsn, ailp->xa_target) <= 0) | |
597 | return; | |
598 | ||
599 | /* | |
600 | * Ensure that the new target is noticed in push code before it clears | |
601 | * the XFS_AIL_PUSHING_BIT. | |
602 | */ | |
603 | smp_wmb(); | |
fe0da767 | 604 | xfs_trans_ail_copy_lsn(ailp, &ailp->xa_target, &threshold_lsn); |
0030807c CH |
605 | smp_wmb(); |
606 | ||
607 | wake_up_process(ailp->xa_task); | |
0bf6a5bd | 608 | } |
1da177e4 | 609 | |
fd074841 DC |
610 | /* |
611 | * Push out all items in the AIL immediately | |
612 | */ | |
613 | void | |
614 | xfs_ail_push_all( | |
615 | struct xfs_ail *ailp) | |
616 | { | |
617 | xfs_lsn_t threshold_lsn = xfs_ail_max_lsn(ailp); | |
618 | ||
619 | if (threshold_lsn) | |
620 | xfs_ail_push(ailp, threshold_lsn); | |
621 | } | |
622 | ||
211e4d43 CH |
623 | /* |
624 | * Push out all items in the AIL immediately and wait until the AIL is empty. | |
625 | */ | |
626 | void | |
627 | xfs_ail_push_all_sync( | |
628 | struct xfs_ail *ailp) | |
629 | { | |
630 | struct xfs_log_item *lip; | |
631 | DEFINE_WAIT(wait); | |
632 | ||
633 | spin_lock(&ailp->xa_lock); | |
634 | while ((lip = xfs_ail_max(ailp)) != NULL) { | |
635 | prepare_to_wait(&ailp->xa_empty, &wait, TASK_UNINTERRUPTIBLE); | |
636 | ailp->xa_target = lip->li_lsn; | |
637 | wake_up_process(ailp->xa_task); | |
638 | spin_unlock(&ailp->xa_lock); | |
639 | schedule(); | |
640 | spin_lock(&ailp->xa_lock); | |
641 | } | |
642 | spin_unlock(&ailp->xa_lock); | |
643 | ||
644 | finish_wait(&ailp->xa_empty, &wait); | |
645 | } | |
646 | ||
0e57f6a3 DC |
647 | /* |
648 | * xfs_trans_ail_update - bulk AIL insertion operation. | |
649 | * | |
650 | * @xfs_trans_ail_update takes an array of log items that all need to be | |
651 | * positioned at the same LSN in the AIL. If an item is not in the AIL, it will | |
652 | * be added. Otherwise, it will be repositioned by removing it and re-adding | |
653 | * it to the AIL. If we move the first item in the AIL, update the log tail to | |
654 | * match the new minimum LSN in the AIL. | |
655 | * | |
656 | * This function takes the AIL lock once to execute the update operations on | |
657 | * all the items in the array, and as such should not be called with the AIL | |
658 | * lock held. As a result, once we have the AIL lock, we need to check each log | |
659 | * item LSN to confirm it needs to be moved forward in the AIL. | |
660 | * | |
661 | * To optimise the insert operation, we delete all the items from the AIL in | |
662 | * the first pass, moving them into a temporary list, then splice the temporary | |
663 | * list into the correct position in the AIL. This avoids needing to do an | |
664 | * insert operation on every item. | |
665 | * | |
666 | * This function must be called with the AIL lock held. The lock is dropped | |
667 | * before returning. | |
668 | */ | |
669 | void | |
670 | xfs_trans_ail_update_bulk( | |
671 | struct xfs_ail *ailp, | |
1d8c95a3 | 672 | struct xfs_ail_cursor *cur, |
0e57f6a3 DC |
673 | struct xfs_log_item **log_items, |
674 | int nr_items, | |
675 | xfs_lsn_t lsn) __releases(ailp->xa_lock) | |
676 | { | |
677 | xfs_log_item_t *mlip; | |
0e57f6a3 DC |
678 | int mlip_changed = 0; |
679 | int i; | |
680 | LIST_HEAD(tmp); | |
681 | ||
e44f4112 | 682 | ASSERT(nr_items > 0); /* Not required, but true. */ |
0e57f6a3 DC |
683 | mlip = xfs_ail_min(ailp); |
684 | ||
685 | for (i = 0; i < nr_items; i++) { | |
686 | struct xfs_log_item *lip = log_items[i]; | |
687 | if (lip->li_flags & XFS_LI_IN_AIL) { | |
688 | /* check if we really need to move the item */ | |
689 | if (XFS_LSN_CMP(lsn, lip->li_lsn) <= 0) | |
690 | continue; | |
691 | ||
750b9c90 | 692 | trace_xfs_ail_move(lip, lip->li_lsn, lsn); |
0e57f6a3 DC |
693 | xfs_ail_delete(ailp, lip); |
694 | if (mlip == lip) | |
695 | mlip_changed = 1; | |
696 | } else { | |
697 | lip->li_flags |= XFS_LI_IN_AIL; | |
750b9c90 | 698 | trace_xfs_ail_insert(lip, 0, lsn); |
0e57f6a3 DC |
699 | } |
700 | lip->li_lsn = lsn; | |
701 | list_add(&lip->li_ail, &tmp); | |
702 | } | |
703 | ||
e44f4112 AE |
704 | if (!list_empty(&tmp)) |
705 | xfs_ail_splice(ailp, cur, &tmp, lsn); | |
0e57f6a3 | 706 | |
1c304625 CH |
707 | if (mlip_changed) { |
708 | if (!XFS_FORCED_SHUTDOWN(ailp->xa_mount)) | |
709 | xlog_assign_tail_lsn_locked(ailp->xa_mount); | |
710 | spin_unlock(&ailp->xa_lock); | |
711 | ||
cfb7cdca | 712 | xfs_log_space_wake(ailp->xa_mount); |
1c304625 CH |
713 | } else { |
714 | spin_unlock(&ailp->xa_lock); | |
0e57f6a3 | 715 | } |
0e57f6a3 DC |
716 | } |
717 | ||
27af1bbf CH |
718 | bool |
719 | xfs_ail_delete_one( | |
720 | struct xfs_ail *ailp, | |
d3a304b6 | 721 | struct xfs_log_item *lip) |
27af1bbf CH |
722 | { |
723 | struct xfs_log_item *mlip = xfs_ail_min(ailp); | |
724 | ||
725 | trace_xfs_ail_delete(lip, mlip->li_lsn, lip->li_lsn); | |
726 | xfs_ail_delete(ailp, lip); | |
d3a304b6 | 727 | xfs_clear_li_failed(lip); |
27af1bbf CH |
728 | lip->li_flags &= ~XFS_LI_IN_AIL; |
729 | lip->li_lsn = 0; | |
730 | ||
731 | return mlip == lip; | |
732 | } | |
733 | ||
734 | /** | |
735 | * Remove a log items from the AIL | |
30136832 DC |
736 | * |
737 | * @xfs_trans_ail_delete_bulk takes an array of log items that all need to | |
738 | * removed from the AIL. The caller is already holding the AIL lock, and done | |
739 | * all the checks necessary to ensure the items passed in via @log_items are | |
740 | * ready for deletion. This includes checking that the items are in the AIL. | |
741 | * | |
742 | * For each log item to be removed, unlink it from the AIL, clear the IN_AIL | |
743 | * flag from the item and reset the item's lsn to 0. If we remove the first | |
744 | * item in the AIL, update the log tail to match the new minimum LSN in the | |
745 | * AIL. | |
746 | * | |
747 | * This function will not drop the AIL lock until all items are removed from | |
748 | * the AIL to minimise the amount of lock traffic on the AIL. This does not | |
749 | * greatly increase the AIL hold time, but does significantly reduce the amount | |
750 | * of traffic on the lock, especially during IO completion. | |
751 | * | |
752 | * This function must be called with the AIL lock held. The lock is dropped | |
753 | * before returning. | |
754 | */ | |
755 | void | |
27af1bbf | 756 | xfs_trans_ail_delete( |
30136832 | 757 | struct xfs_ail *ailp, |
27af1bbf | 758 | struct xfs_log_item *lip, |
04913fdd | 759 | int shutdown_type) __releases(ailp->xa_lock) |
30136832 | 760 | { |
27af1bbf CH |
761 | struct xfs_mount *mp = ailp->xa_mount; |
762 | bool mlip_changed; | |
30136832 | 763 | |
27af1bbf CH |
764 | if (!(lip->li_flags & XFS_LI_IN_AIL)) { |
765 | spin_unlock(&ailp->xa_lock); | |
766 | if (!XFS_FORCED_SHUTDOWN(mp)) { | |
767 | xfs_alert_tag(mp, XFS_PTAG_AILDELETE, | |
768 | "%s: attempting to delete a log item that is not in the AIL", | |
769 | __func__); | |
770 | xfs_force_shutdown(mp, shutdown_type); | |
30136832 | 771 | } |
27af1bbf | 772 | return; |
30136832 DC |
773 | } |
774 | ||
27af1bbf | 775 | mlip_changed = xfs_ail_delete_one(ailp, lip); |
1c304625 | 776 | if (mlip_changed) { |
27af1bbf CH |
777 | if (!XFS_FORCED_SHUTDOWN(mp)) |
778 | xlog_assign_tail_lsn_locked(mp); | |
211e4d43 CH |
779 | if (list_empty(&ailp->xa_ail)) |
780 | wake_up_all(&ailp->xa_empty); | |
27af1bbf | 781 | } |
1c304625 | 782 | |
27af1bbf CH |
783 | spin_unlock(&ailp->xa_lock); |
784 | if (mlip_changed) | |
cfb7cdca | 785 | xfs_log_space_wake(ailp->xa_mount); |
30136832 | 786 | } |
1da177e4 | 787 | |
249a8c11 | 788 | int |
1da177e4 LT |
789 | xfs_trans_ail_init( |
790 | xfs_mount_t *mp) | |
791 | { | |
82fa9012 DC |
792 | struct xfs_ail *ailp; |
793 | ||
794 | ailp = kmem_zalloc(sizeof(struct xfs_ail), KM_MAYFAIL); | |
795 | if (!ailp) | |
2451337d | 796 | return -ENOMEM; |
82fa9012 DC |
797 | |
798 | ailp->xa_mount = mp; | |
799 | INIT_LIST_HEAD(&ailp->xa_ail); | |
af3e4022 | 800 | INIT_LIST_HEAD(&ailp->xa_cursors); |
c7e8f268 | 801 | spin_lock_init(&ailp->xa_lock); |
43ff2122 | 802 | INIT_LIST_HEAD(&ailp->xa_buf_list); |
211e4d43 | 803 | init_waitqueue_head(&ailp->xa_empty); |
0030807c CH |
804 | |
805 | ailp->xa_task = kthread_run(xfsaild, ailp, "xfsaild/%s", | |
806 | ailp->xa_mount->m_fsname); | |
807 | if (IS_ERR(ailp->xa_task)) | |
808 | goto out_free_ailp; | |
809 | ||
27d8d5fe DC |
810 | mp->m_ail = ailp; |
811 | return 0; | |
0030807c CH |
812 | |
813 | out_free_ailp: | |
814 | kmem_free(ailp); | |
2451337d | 815 | return -ENOMEM; |
249a8c11 DC |
816 | } |
817 | ||
818 | void | |
819 | xfs_trans_ail_destroy( | |
820 | xfs_mount_t *mp) | |
821 | { | |
82fa9012 DC |
822 | struct xfs_ail *ailp = mp->m_ail; |
823 | ||
0030807c | 824 | kthread_stop(ailp->xa_task); |
82fa9012 | 825 | kmem_free(ailp); |
1da177e4 | 826 | } |