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1da177e4 | 1 | /* |
7b718769 NS |
2 | * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. |
3 | * All Rights Reserved. | |
1da177e4 | 4 | * |
7b718769 NS |
5 | * This program is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU General Public License as | |
1da177e4 LT |
7 | * published by the Free Software Foundation. |
8 | * | |
7b718769 NS |
9 | * This program is distributed in the hope that it would be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
1da177e4 | 13 | * |
7b718769 NS |
14 | * You should have received a copy of the GNU General Public License |
15 | * along with this program; if not, write the Free Software Foundation, | |
16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
1da177e4 | 17 | */ |
1da177e4 | 18 | #include "xfs.h" |
a844f451 | 19 | #include "xfs_fs.h" |
1da177e4 | 20 | #include "xfs_types.h" |
1da177e4 | 21 | #include "xfs_log.h" |
a844f451 | 22 | #include "xfs_inum.h" |
1da177e4 LT |
23 | #include "xfs_trans.h" |
24 | #include "xfs_sb.h" | |
da353b0d | 25 | #include "xfs_ag.h" |
1da177e4 LT |
26 | #include "xfs_dmapi.h" |
27 | #include "xfs_mount.h" | |
28 | #include "xfs_trans_priv.h" | |
29 | #include "xfs_error.h" | |
30 | ||
535f6b37 JJS |
31 | STATIC void xfs_ail_insert(xfs_ail_t *, xfs_log_item_t *); |
32 | STATIC xfs_log_item_t * xfs_ail_delete(xfs_ail_t *, xfs_log_item_t *); | |
33 | STATIC xfs_log_item_t * xfs_ail_min(xfs_ail_t *); | |
34 | STATIC xfs_log_item_t * xfs_ail_next(xfs_ail_t *, xfs_log_item_t *); | |
1da177e4 LT |
35 | |
36 | #ifdef DEBUG | |
535f6b37 | 37 | STATIC void xfs_ail_check(xfs_ail_t *, xfs_log_item_t *); |
1da177e4 | 38 | #else |
de08dbc1 | 39 | #define xfs_ail_check(a,l) |
1da177e4 LT |
40 | #endif /* DEBUG */ |
41 | ||
42 | ||
43 | /* | |
44 | * This is called by the log manager code to determine the LSN | |
45 | * of the tail of the log. This is exactly the LSN of the first | |
46 | * item in the AIL. If the AIL is empty, then this function | |
47 | * returns 0. | |
48 | * | |
49 | * We need the AIL lock in order to get a coherent read of the | |
50 | * lsn of the last item in the AIL. | |
51 | */ | |
52 | xfs_lsn_t | |
53 | xfs_trans_tail_ail( | |
54 | xfs_mount_t *mp) | |
55 | { | |
56 | xfs_lsn_t lsn; | |
57 | xfs_log_item_t *lip; | |
1da177e4 | 58 | |
287f3dad | 59 | spin_lock(&mp->m_ail_lock); |
535f6b37 | 60 | lip = xfs_ail_min(&mp->m_ail); |
1da177e4 LT |
61 | if (lip == NULL) { |
62 | lsn = (xfs_lsn_t)0; | |
63 | } else { | |
64 | lsn = lip->li_lsn; | |
65 | } | |
287f3dad | 66 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
67 | |
68 | return lsn; | |
69 | } | |
70 | ||
71 | /* | |
72 | * xfs_trans_push_ail | |
73 | * | |
249a8c11 DC |
74 | * This routine is called to move the tail of the AIL forward. It does this by |
75 | * trying to flush items in the AIL whose lsns are below the given | |
76 | * threshold_lsn. | |
1da177e4 | 77 | * |
249a8c11 DC |
78 | * the push is run asynchronously in a separate thread, so we return the tail |
79 | * of the log right now instead of the tail after the push. This means we will | |
80 | * either continue right away, or we will sleep waiting on the async thread to | |
81 | * do it's work. | |
82 | * | |
83 | * We do this unlocked - we only need to know whether there is anything in the | |
84 | * AIL at the time we are called. We don't need to access the contents of | |
85 | * any of the objects, so the lock is not needed. | |
1da177e4 | 86 | */ |
249a8c11 | 87 | void |
1da177e4 LT |
88 | xfs_trans_push_ail( |
89 | xfs_mount_t *mp, | |
90 | xfs_lsn_t threshold_lsn) | |
91 | { | |
1da177e4 | 92 | xfs_log_item_t *lip; |
1da177e4 | 93 | |
535f6b37 | 94 | lip = xfs_ail_min(&mp->m_ail); |
249a8c11 DC |
95 | if (lip && !XFS_FORCED_SHUTDOWN(mp)) { |
96 | if (XFS_LSN_CMP(threshold_lsn, mp->m_ail.xa_target) > 0) | |
97 | xfsaild_wakeup(mp, threshold_lsn); | |
98 | } | |
99 | } | |
100 | ||
101 | /* | |
102 | * Return the item in the AIL with the current lsn. | |
103 | * Return the current tree generation number for use | |
104 | * in calls to xfs_trans_next_ail(). | |
105 | */ | |
106 | STATIC xfs_log_item_t * | |
107 | xfs_trans_first_push_ail( | |
108 | xfs_mount_t *mp, | |
109 | int *gen, | |
110 | xfs_lsn_t lsn) | |
111 | { | |
112 | xfs_log_item_t *lip; | |
113 | ||
535f6b37 | 114 | lip = xfs_ail_min(&mp->m_ail); |
249a8c11 DC |
115 | *gen = (int)mp->m_ail.xa_gen; |
116 | if (lsn == 0) | |
117 | return lip; | |
118 | ||
535f6b37 JJS |
119 | list_for_each_entry(lip, &mp->m_ail.xa_ail, li_ail) { |
120 | if (XFS_LSN_CMP(lip->li_lsn, lsn) >= 0) | |
121 | return lip; | |
122 | } | |
249a8c11 | 123 | |
535f6b37 | 124 | return NULL; |
249a8c11 DC |
125 | } |
126 | ||
127 | /* | |
128 | * Function that does the work of pushing on the AIL | |
129 | */ | |
130 | long | |
131 | xfsaild_push( | |
132 | xfs_mount_t *mp, | |
133 | xfs_lsn_t *last_lsn) | |
134 | { | |
135 | long tout = 1000; /* milliseconds */ | |
136 | xfs_lsn_t last_pushed_lsn = *last_lsn; | |
137 | xfs_lsn_t target = mp->m_ail.xa_target; | |
138 | xfs_lsn_t lsn; | |
139 | xfs_log_item_t *lip; | |
140 | int gen; | |
141 | int restarts; | |
142 | int flush_log, count, stuck; | |
143 | ||
144 | #define XFS_TRANS_PUSH_AIL_RESTARTS 10 | |
1da177e4 | 145 | |
287f3dad | 146 | spin_lock(&mp->m_ail_lock); |
249a8c11 DC |
147 | lip = xfs_trans_first_push_ail(mp, &gen, *last_lsn); |
148 | if (!lip || XFS_FORCED_SHUTDOWN(mp)) { | |
1da177e4 | 149 | /* |
249a8c11 | 150 | * AIL is empty or our push has reached the end. |
1da177e4 | 151 | */ |
287f3dad | 152 | spin_unlock(&mp->m_ail_lock); |
249a8c11 DC |
153 | last_pushed_lsn = 0; |
154 | goto out; | |
1da177e4 LT |
155 | } |
156 | ||
157 | XFS_STATS_INC(xs_push_ail); | |
158 | ||
159 | /* | |
160 | * While the item we are looking at is below the given threshold | |
249a8c11 | 161 | * try to flush it out. We'd like not to stop until we've at least |
1da177e4 | 162 | * tried to push on everything in the AIL with an LSN less than |
249a8c11 DC |
163 | * the given threshold. |
164 | * | |
165 | * However, we will stop after a certain number of pushes and wait | |
166 | * for a reduced timeout to fire before pushing further. This | |
167 | * prevents use from spinning when we can't do anything or there is | |
168 | * lots of contention on the AIL lists. | |
1da177e4 | 169 | */ |
249a8c11 DC |
170 | tout = 10; |
171 | lsn = lip->li_lsn; | |
172 | flush_log = stuck = count = restarts = 0; | |
173 | while ((XFS_LSN_CMP(lip->li_lsn, target) < 0)) { | |
174 | int lock_result; | |
1da177e4 | 175 | /* |
249a8c11 DC |
176 | * If we can lock the item without sleeping, unlock the AIL |
177 | * lock and flush the item. Then re-grab the AIL lock so we | |
178 | * can look for the next item on the AIL. List changes are | |
179 | * handled by the AIL lookup functions internally | |
1da177e4 | 180 | * |
249a8c11 DC |
181 | * If we can't lock the item, either its holder will flush it |
182 | * or it is already being flushed or it is being relogged. In | |
183 | * any of these case it is being taken care of and we can just | |
184 | * skip to the next item in the list. | |
1da177e4 LT |
185 | */ |
186 | lock_result = IOP_TRYLOCK(lip); | |
249a8c11 | 187 | spin_unlock(&mp->m_ail_lock); |
1da177e4 | 188 | switch (lock_result) { |
249a8c11 | 189 | case XFS_ITEM_SUCCESS: |
1da177e4 LT |
190 | XFS_STATS_INC(xs_push_ail_success); |
191 | IOP_PUSH(lip); | |
249a8c11 | 192 | last_pushed_lsn = lsn; |
1da177e4 LT |
193 | break; |
194 | ||
249a8c11 | 195 | case XFS_ITEM_PUSHBUF: |
1da177e4 | 196 | XFS_STATS_INC(xs_push_ail_pushbuf); |
1da177e4 | 197 | IOP_PUSHBUF(lip); |
249a8c11 | 198 | last_pushed_lsn = lsn; |
1da177e4 LT |
199 | break; |
200 | ||
249a8c11 | 201 | case XFS_ITEM_PINNED: |
1da177e4 | 202 | XFS_STATS_INC(xs_push_ail_pinned); |
249a8c11 | 203 | stuck++; |
1da177e4 LT |
204 | flush_log = 1; |
205 | break; | |
206 | ||
249a8c11 | 207 | case XFS_ITEM_LOCKED: |
1da177e4 | 208 | XFS_STATS_INC(xs_push_ail_locked); |
249a8c11 DC |
209 | last_pushed_lsn = lsn; |
210 | stuck++; | |
1da177e4 LT |
211 | break; |
212 | ||
249a8c11 | 213 | case XFS_ITEM_FLUSHING: |
1da177e4 | 214 | XFS_STATS_INC(xs_push_ail_flushing); |
249a8c11 DC |
215 | last_pushed_lsn = lsn; |
216 | stuck++; | |
1da177e4 LT |
217 | break; |
218 | ||
249a8c11 | 219 | default: |
1da177e4 LT |
220 | ASSERT(0); |
221 | break; | |
222 | } | |
223 | ||
249a8c11 DC |
224 | spin_lock(&mp->m_ail_lock); |
225 | /* should we bother continuing? */ | |
226 | if (XFS_FORCED_SHUTDOWN(mp)) | |
1da177e4 | 227 | break; |
249a8c11 DC |
228 | ASSERT(mp->m_log); |
229 | ||
230 | count++; | |
1da177e4 | 231 | |
249a8c11 DC |
232 | /* |
233 | * Are there too many items we can't do anything with? | |
234 | * If we we are skipping too many items because we can't flush | |
235 | * them or they are already being flushed, we back off and | |
236 | * given them time to complete whatever operation is being | |
237 | * done. i.e. remove pressure from the AIL while we can't make | |
238 | * progress so traversals don't slow down further inserts and | |
239 | * removals to/from the AIL. | |
240 | * | |
241 | * The value of 100 is an arbitrary magic number based on | |
242 | * observation. | |
243 | */ | |
244 | if (stuck > 100) | |
245 | break; | |
246 | ||
247 | lip = xfs_trans_next_ail(mp, lip, &gen, &restarts); | |
248 | if (lip == NULL) | |
249 | break; | |
250 | if (restarts > XFS_TRANS_PUSH_AIL_RESTARTS) | |
251 | break; | |
252 | lsn = lip->li_lsn; | |
1da177e4 | 253 | } |
249a8c11 | 254 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
255 | |
256 | if (flush_log) { | |
257 | /* | |
258 | * If something we need to push out was pinned, then | |
259 | * push out the log so it will become unpinned and | |
260 | * move forward in the AIL. | |
261 | */ | |
1da177e4 LT |
262 | XFS_STATS_INC(xs_push_ail_flush); |
263 | xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE); | |
1da177e4 LT |
264 | } |
265 | ||
92d9cd10 DC |
266 | if (!count) { |
267 | /* We're past our target or empty, so idle */ | |
268 | tout = 1000; | |
269 | } else if (XFS_LSN_CMP(lsn, target) >= 0) { | |
270 | /* | |
271 | * We reached the target so wait a bit longer for I/O to | |
272 | * complete and remove pushed items from the AIL before we | |
273 | * start the next scan from the start of the AIL. | |
274 | */ | |
249a8c11 DC |
275 | tout += 20; |
276 | last_pushed_lsn = 0; | |
277 | } else if ((restarts > XFS_TRANS_PUSH_AIL_RESTARTS) || | |
92d9cd10 | 278 | ((stuck * 100) / count > 90)) { |
249a8c11 DC |
279 | /* |
280 | * Either there is a lot of contention on the AIL or we | |
281 | * are stuck due to operations in progress. "Stuck" in this | |
282 | * case is defined as >90% of the items we tried to push | |
283 | * were stuck. | |
284 | * | |
285 | * Backoff a bit more to allow some I/O to complete before | |
286 | * continuing from where we were. | |
287 | */ | |
288 | tout += 10; | |
1da177e4 | 289 | } |
249a8c11 DC |
290 | out: |
291 | *last_lsn = last_pushed_lsn; | |
292 | return tout; | |
293 | } /* xfsaild_push */ | |
1da177e4 LT |
294 | |
295 | ||
296 | /* | |
297 | * This is to be called when an item is unlocked that may have | |
298 | * been in the AIL. It will wake up the first member of the AIL | |
299 | * wait list if this item's unlocking might allow it to progress. | |
300 | * If the item is in the AIL, then we need to get the AIL lock | |
301 | * while doing our checking so we don't race with someone going | |
302 | * to sleep waiting for this event in xfs_trans_push_ail(). | |
303 | */ | |
304 | void | |
305 | xfs_trans_unlocked_item( | |
306 | xfs_mount_t *mp, | |
307 | xfs_log_item_t *lip) | |
308 | { | |
309 | xfs_log_item_t *min_lip; | |
310 | ||
311 | /* | |
312 | * If we're forcibly shutting down, we may have | |
313 | * unlocked log items arbitrarily. The last thing | |
314 | * we want to do is to move the tail of the log | |
315 | * over some potentially valid data. | |
316 | */ | |
317 | if (!(lip->li_flags & XFS_LI_IN_AIL) || | |
318 | XFS_FORCED_SHUTDOWN(mp)) { | |
319 | return; | |
320 | } | |
321 | ||
322 | /* | |
323 | * This is the one case where we can call into xfs_ail_min() | |
324 | * without holding the AIL lock because we only care about the | |
325 | * case where we are at the tail of the AIL. If the object isn't | |
326 | * at the tail, it doesn't matter what result we get back. This | |
327 | * is slightly racy because since we were just unlocked, we could | |
328 | * go to sleep between the call to xfs_ail_min and the call to | |
329 | * xfs_log_move_tail, have someone else lock us, commit to us disk, | |
330 | * move us out of the tail of the AIL, and then we wake up. However, | |
331 | * the call to xfs_log_move_tail() doesn't do anything if there's | |
332 | * not enough free space to wake people up so we're safe calling it. | |
333 | */ | |
535f6b37 | 334 | min_lip = xfs_ail_min(&mp->m_ail); |
1da177e4 LT |
335 | |
336 | if (min_lip == lip) | |
337 | xfs_log_move_tail(mp, 1); | |
338 | } /* xfs_trans_unlocked_item */ | |
339 | ||
340 | ||
341 | /* | |
342 | * Update the position of the item in the AIL with the new | |
343 | * lsn. If it is not yet in the AIL, add it. Otherwise, move | |
344 | * it to its new position by removing it and re-adding it. | |
345 | * | |
346 | * Wakeup anyone with an lsn less than the item's lsn. If the item | |
347 | * we move in the AIL is the minimum one, update the tail lsn in the | |
348 | * log manager. | |
349 | * | |
350 | * Increment the AIL's generation count to indicate that the tree | |
351 | * has changed. | |
352 | * | |
353 | * This function must be called with the AIL lock held. The lock | |
287f3dad | 354 | * is dropped before returning. |
1da177e4 LT |
355 | */ |
356 | void | |
357 | xfs_trans_update_ail( | |
358 | xfs_mount_t *mp, | |
359 | xfs_log_item_t *lip, | |
287f3dad | 360 | xfs_lsn_t lsn) __releases(mp->m_ail_lock) |
1da177e4 | 361 | { |
1da177e4 LT |
362 | xfs_log_item_t *dlip=NULL; |
363 | xfs_log_item_t *mlip; /* ptr to minimum lip */ | |
364 | ||
535f6b37 | 365 | mlip = xfs_ail_min(&mp->m_ail); |
1da177e4 LT |
366 | |
367 | if (lip->li_flags & XFS_LI_IN_AIL) { | |
535f6b37 | 368 | dlip = xfs_ail_delete(&mp->m_ail, lip); |
1da177e4 LT |
369 | ASSERT(dlip == lip); |
370 | } else { | |
371 | lip->li_flags |= XFS_LI_IN_AIL; | |
372 | } | |
373 | ||
374 | lip->li_lsn = lsn; | |
375 | ||
535f6b37 | 376 | xfs_ail_insert(&mp->m_ail, lip); |
249a8c11 | 377 | mp->m_ail.xa_gen++; |
1da177e4 LT |
378 | |
379 | if (mlip == dlip) { | |
535f6b37 | 380 | mlip = xfs_ail_min(&mp->m_ail); |
287f3dad | 381 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
382 | xfs_log_move_tail(mp, mlip->li_lsn); |
383 | } else { | |
287f3dad | 384 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
385 | } |
386 | ||
387 | ||
388 | } /* xfs_trans_update_ail */ | |
389 | ||
390 | /* | |
391 | * Delete the given item from the AIL. It must already be in | |
392 | * the AIL. | |
393 | * | |
394 | * Wakeup anyone with an lsn less than item's lsn. If the item | |
395 | * we delete in the AIL is the minimum one, update the tail lsn in the | |
396 | * log manager. | |
397 | * | |
398 | * Clear the IN_AIL flag from the item, reset its lsn to 0, and | |
399 | * bump the AIL's generation count to indicate that the tree | |
400 | * has changed. | |
401 | * | |
402 | * This function must be called with the AIL lock held. The lock | |
287f3dad | 403 | * is dropped before returning. |
1da177e4 LT |
404 | */ |
405 | void | |
406 | xfs_trans_delete_ail( | |
407 | xfs_mount_t *mp, | |
287f3dad | 408 | xfs_log_item_t *lip) __releases(mp->m_ail_lock) |
1da177e4 | 409 | { |
1da177e4 LT |
410 | xfs_log_item_t *dlip; |
411 | xfs_log_item_t *mlip; | |
412 | ||
413 | if (lip->li_flags & XFS_LI_IN_AIL) { | |
535f6b37 JJS |
414 | mlip = xfs_ail_min(&mp->m_ail); |
415 | dlip = xfs_ail_delete(&mp->m_ail, lip); | |
1da177e4 LT |
416 | ASSERT(dlip == lip); |
417 | ||
418 | ||
419 | lip->li_flags &= ~XFS_LI_IN_AIL; | |
420 | lip->li_lsn = 0; | |
249a8c11 | 421 | mp->m_ail.xa_gen++; |
1da177e4 LT |
422 | |
423 | if (mlip == dlip) { | |
535f6b37 | 424 | mlip = xfs_ail_min(&mp->m_ail); |
287f3dad | 425 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
426 | xfs_log_move_tail(mp, (mlip ? mlip->li_lsn : 0)); |
427 | } else { | |
287f3dad | 428 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
429 | } |
430 | } | |
431 | else { | |
432 | /* | |
433 | * If the file system is not being shutdown, we are in | |
434 | * serious trouble if we get to this stage. | |
435 | */ | |
436 | if (XFS_FORCED_SHUTDOWN(mp)) | |
287f3dad | 437 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
438 | else { |
439 | xfs_cmn_err(XFS_PTAG_AILDELETE, CE_ALERT, mp, | |
7d04a335 | 440 | "%s: attempting to delete a log item that is not in the AIL", |
34a622b2 | 441 | __func__); |
287f3dad | 442 | spin_unlock(&mp->m_ail_lock); |
7d04a335 | 443 | xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); |
1da177e4 LT |
444 | } |
445 | } | |
446 | } | |
447 | ||
448 | ||
449 | ||
450 | /* | |
451 | * Return the item in the AIL with the smallest lsn. | |
452 | * Return the current tree generation number for use | |
453 | * in calls to xfs_trans_next_ail(). | |
454 | */ | |
455 | xfs_log_item_t * | |
456 | xfs_trans_first_ail( | |
457 | xfs_mount_t *mp, | |
458 | int *gen) | |
459 | { | |
460 | xfs_log_item_t *lip; | |
461 | ||
535f6b37 | 462 | lip = xfs_ail_min(&mp->m_ail); |
249a8c11 | 463 | *gen = (int)mp->m_ail.xa_gen; |
1da177e4 | 464 | |
249a8c11 | 465 | return lip; |
1da177e4 LT |
466 | } |
467 | ||
468 | /* | |
469 | * If the generation count of the tree has not changed since the | |
470 | * caller last took something from the AIL, then return the elmt | |
471 | * in the tree which follows the one given. If the count has changed, | |
472 | * then return the minimum elmt of the AIL and bump the restarts counter | |
473 | * if one is given. | |
474 | */ | |
475 | xfs_log_item_t * | |
476 | xfs_trans_next_ail( | |
477 | xfs_mount_t *mp, | |
478 | xfs_log_item_t *lip, | |
479 | int *gen, | |
480 | int *restarts) | |
481 | { | |
482 | xfs_log_item_t *nlip; | |
483 | ||
484 | ASSERT(mp && lip && gen); | |
249a8c11 | 485 | if (mp->m_ail.xa_gen == *gen) { |
535f6b37 | 486 | nlip = xfs_ail_next(&mp->m_ail, lip); |
1da177e4 | 487 | } else { |
535f6b37 | 488 | nlip = xfs_ail_min(&mp->m_ail); |
249a8c11 | 489 | *gen = (int)mp->m_ail.xa_gen; |
1da177e4 LT |
490 | if (restarts != NULL) { |
491 | XFS_STATS_INC(xs_push_ail_restarts); | |
492 | (*restarts)++; | |
493 | } | |
494 | } | |
495 | ||
496 | return (nlip); | |
497 | } | |
498 | ||
499 | ||
500 | /* | |
501 | * The active item list (AIL) is a doubly linked list of log | |
502 | * items sorted by ascending lsn. The base of the list is | |
503 | * a forw/back pointer pair embedded in the xfs mount structure. | |
504 | * The base is initialized with both pointers pointing to the | |
505 | * base. This case always needs to be distinguished, because | |
506 | * the base has no lsn to look at. We almost always insert | |
507 | * at the end of the list, so on inserts we search from the | |
508 | * end of the list to find where the new item belongs. | |
509 | */ | |
510 | ||
511 | /* | |
512 | * Initialize the doubly linked list to point only to itself. | |
513 | */ | |
249a8c11 | 514 | int |
1da177e4 LT |
515 | xfs_trans_ail_init( |
516 | xfs_mount_t *mp) | |
517 | { | |
535f6b37 | 518 | INIT_LIST_HEAD(&mp->m_ail.xa_ail); |
249a8c11 DC |
519 | return xfsaild_start(mp); |
520 | } | |
521 | ||
522 | void | |
523 | xfs_trans_ail_destroy( | |
524 | xfs_mount_t *mp) | |
525 | { | |
526 | xfsaild_stop(mp); | |
1da177e4 LT |
527 | } |
528 | ||
529 | /* | |
530 | * Insert the given log item into the AIL. | |
531 | * We almost always insert at the end of the list, so on inserts | |
532 | * we search from the end of the list to find where the | |
533 | * new item belongs. | |
534 | */ | |
535 | STATIC void | |
536 | xfs_ail_insert( | |
535f6b37 | 537 | xfs_ail_t *ailp, |
1da177e4 LT |
538 | xfs_log_item_t *lip) |
539 | /* ARGSUSED */ | |
540 | { | |
541 | xfs_log_item_t *next_lip; | |
542 | ||
543 | /* | |
544 | * If the list is empty, just insert the item. | |
545 | */ | |
535f6b37 JJS |
546 | if (list_empty(&ailp->xa_ail)) { |
547 | list_add(&lip->li_ail, &ailp->xa_ail); | |
1da177e4 LT |
548 | return; |
549 | } | |
550 | ||
535f6b37 JJS |
551 | list_for_each_entry_reverse(next_lip, &ailp->xa_ail, li_ail) { |
552 | if (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0) | |
553 | break; | |
1da177e4 | 554 | } |
535f6b37 JJS |
555 | |
556 | ASSERT((&next_lip->li_ail == &ailp->xa_ail) || | |
1da177e4 | 557 | (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0)); |
1da177e4 | 558 | |
535f6b37 JJS |
559 | list_add(&lip->li_ail, &next_lip->li_ail); |
560 | ||
561 | xfs_ail_check(ailp, lip); | |
1da177e4 LT |
562 | return; |
563 | } | |
564 | ||
565 | /* | |
566 | * Delete the given item from the AIL. Return a pointer to the item. | |
567 | */ | |
568 | /*ARGSUSED*/ | |
569 | STATIC xfs_log_item_t * | |
570 | xfs_ail_delete( | |
535f6b37 | 571 | xfs_ail_t *ailp, |
1da177e4 LT |
572 | xfs_log_item_t *lip) |
573 | /* ARGSUSED */ | |
574 | { | |
535f6b37 JJS |
575 | xfs_ail_check(ailp, lip); |
576 | ||
577 | list_del(&lip->li_ail); | |
1da177e4 | 578 | |
1da177e4 LT |
579 | return lip; |
580 | } | |
581 | ||
582 | /* | |
583 | * Return a pointer to the first item in the AIL. | |
584 | * If the AIL is empty, then return NULL. | |
585 | */ | |
586 | STATIC xfs_log_item_t * | |
587 | xfs_ail_min( | |
535f6b37 | 588 | xfs_ail_t *ailp) |
1da177e4 LT |
589 | /* ARGSUSED */ |
590 | { | |
535f6b37 | 591 | if (list_empty(&ailp->xa_ail)) |
1da177e4 | 592 | return NULL; |
535f6b37 JJS |
593 | |
594 | return list_first_entry(&ailp->xa_ail, xfs_log_item_t, li_ail); | |
1da177e4 LT |
595 | } |
596 | ||
597 | /* | |
598 | * Return a pointer to the item which follows | |
599 | * the given item in the AIL. If the given item | |
600 | * is the last item in the list, then return NULL. | |
601 | */ | |
602 | STATIC xfs_log_item_t * | |
603 | xfs_ail_next( | |
535f6b37 | 604 | xfs_ail_t *ailp, |
1da177e4 LT |
605 | xfs_log_item_t *lip) |
606 | /* ARGSUSED */ | |
607 | { | |
535f6b37 | 608 | if (lip->li_ail.next == &ailp->xa_ail) |
1da177e4 | 609 | return NULL; |
1da177e4 | 610 | |
535f6b37 | 611 | return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail); |
1da177e4 LT |
612 | } |
613 | ||
614 | #ifdef DEBUG | |
615 | /* | |
616 | * Check that the list is sorted as it should be. | |
617 | */ | |
618 | STATIC void | |
619 | xfs_ail_check( | |
535f6b37 | 620 | xfs_ail_t *ailp, |
de08dbc1 | 621 | xfs_log_item_t *lip) |
1da177e4 | 622 | { |
1da177e4 LT |
623 | xfs_log_item_t *prev_lip; |
624 | ||
535f6b37 | 625 | if (list_empty(&ailp->xa_ail)) |
1da177e4 | 626 | return; |
1da177e4 | 627 | |
de08dbc1 DC |
628 | /* |
629 | * Check the next and previous entries are valid. | |
630 | */ | |
631 | ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0); | |
535f6b37 JJS |
632 | prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail); |
633 | if (&prev_lip->li_ail != &ailp->xa_ail) | |
de08dbc1 | 634 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0); |
535f6b37 JJS |
635 | |
636 | prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail); | |
637 | if (&prev_lip->li_ail != &ailp->xa_ail) | |
de08dbc1 | 638 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0); |
de08dbc1 DC |
639 | |
640 | ||
641 | #ifdef XFS_TRANS_DEBUG | |
1da177e4 | 642 | /* |
535f6b37 JJS |
643 | * Walk the list checking lsn ordering, and that every entry has the |
644 | * XFS_LI_IN_AIL flag set. This is really expensive, so only do it | |
645 | * when specifically debugging the transaction subsystem. | |
1da177e4 | 646 | */ |
535f6b37 JJS |
647 | prev_lip = list_entry(&ailp->xa_ail, xfs_log_item_t, li_ail); |
648 | list_for_each_entry(lip, &ailp->xa_ail, li_ail) { | |
649 | if (&prev_lip->li_ail != &ailp->xa_ail) | |
1da177e4 | 650 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0); |
1da177e4 LT |
651 | ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0); |
652 | prev_lip = lip; | |
1da177e4 | 653 | } |
de08dbc1 | 654 | #endif /* XFS_TRANS_DEBUG */ |
1da177e4 LT |
655 | } |
656 | #endif /* DEBUG */ |