]>
Commit | Line | Data |
---|---|---|
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 | ||
31 | STATIC void xfs_ail_insert(xfs_ail_entry_t *, xfs_log_item_t *); | |
32 | STATIC xfs_log_item_t * xfs_ail_delete(xfs_ail_entry_t *, xfs_log_item_t *); | |
33 | STATIC xfs_log_item_t * xfs_ail_min(xfs_ail_entry_t *); | |
34 | STATIC xfs_log_item_t * xfs_ail_next(xfs_ail_entry_t *, xfs_log_item_t *); | |
35 | ||
36 | #ifdef DEBUG | |
37 | STATIC void xfs_ail_check(xfs_ail_entry_t *); | |
38 | #else | |
39 | #define xfs_ail_check(a) | |
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); |
249a8c11 | 60 | lip = xfs_ail_min(&(mp->m_ail.xa_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 | |
249a8c11 DC |
94 | lip = xfs_ail_min(&mp->m_ail.xa_ail); |
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 | ||
114 | lip = xfs_ail_min(&(mp->m_ail.xa_ail)); | |
115 | *gen = (int)mp->m_ail.xa_gen; | |
116 | if (lsn == 0) | |
117 | return lip; | |
118 | ||
119 | while (lip && (XFS_LSN_CMP(lip->li_lsn, lsn) < 0)) | |
120 | lip = lip->li_ail.ail_forw; | |
121 | ||
122 | return lip; | |
123 | } | |
124 | ||
125 | /* | |
126 | * Function that does the work of pushing on the AIL | |
127 | */ | |
128 | long | |
129 | xfsaild_push( | |
130 | xfs_mount_t *mp, | |
131 | xfs_lsn_t *last_lsn) | |
132 | { | |
133 | long tout = 1000; /* milliseconds */ | |
134 | xfs_lsn_t last_pushed_lsn = *last_lsn; | |
135 | xfs_lsn_t target = mp->m_ail.xa_target; | |
136 | xfs_lsn_t lsn; | |
137 | xfs_log_item_t *lip; | |
138 | int gen; | |
139 | int restarts; | |
140 | int flush_log, count, stuck; | |
141 | ||
142 | #define XFS_TRANS_PUSH_AIL_RESTARTS 10 | |
1da177e4 | 143 | |
287f3dad | 144 | spin_lock(&mp->m_ail_lock); |
249a8c11 DC |
145 | lip = xfs_trans_first_push_ail(mp, &gen, *last_lsn); |
146 | if (!lip || XFS_FORCED_SHUTDOWN(mp)) { | |
1da177e4 | 147 | /* |
249a8c11 | 148 | * AIL is empty or our push has reached the end. |
1da177e4 | 149 | */ |
287f3dad | 150 | spin_unlock(&mp->m_ail_lock); |
249a8c11 DC |
151 | last_pushed_lsn = 0; |
152 | goto out; | |
1da177e4 LT |
153 | } |
154 | ||
155 | XFS_STATS_INC(xs_push_ail); | |
156 | ||
157 | /* | |
158 | * While the item we are looking at is below the given threshold | |
249a8c11 | 159 | * try to flush it out. We'd like not to stop until we've at least |
1da177e4 | 160 | * tried to push on everything in the AIL with an LSN less than |
249a8c11 DC |
161 | * the given threshold. |
162 | * | |
163 | * However, we will stop after a certain number of pushes and wait | |
164 | * for a reduced timeout to fire before pushing further. This | |
165 | * prevents use from spinning when we can't do anything or there is | |
166 | * lots of contention on the AIL lists. | |
1da177e4 | 167 | */ |
249a8c11 DC |
168 | tout = 10; |
169 | lsn = lip->li_lsn; | |
170 | flush_log = stuck = count = restarts = 0; | |
171 | while ((XFS_LSN_CMP(lip->li_lsn, target) < 0)) { | |
172 | int lock_result; | |
1da177e4 | 173 | /* |
249a8c11 DC |
174 | * If we can lock the item without sleeping, unlock the AIL |
175 | * lock and flush the item. Then re-grab the AIL lock so we | |
176 | * can look for the next item on the AIL. List changes are | |
177 | * handled by the AIL lookup functions internally | |
1da177e4 | 178 | * |
249a8c11 DC |
179 | * If we can't lock the item, either its holder will flush it |
180 | * or it is already being flushed or it is being relogged. In | |
181 | * any of these case it is being taken care of and we can just | |
182 | * skip to the next item in the list. | |
1da177e4 LT |
183 | */ |
184 | lock_result = IOP_TRYLOCK(lip); | |
249a8c11 | 185 | spin_unlock(&mp->m_ail_lock); |
1da177e4 | 186 | switch (lock_result) { |
249a8c11 | 187 | case XFS_ITEM_SUCCESS: |
1da177e4 LT |
188 | XFS_STATS_INC(xs_push_ail_success); |
189 | IOP_PUSH(lip); | |
249a8c11 | 190 | last_pushed_lsn = lsn; |
1da177e4 LT |
191 | break; |
192 | ||
249a8c11 | 193 | case XFS_ITEM_PUSHBUF: |
1da177e4 | 194 | XFS_STATS_INC(xs_push_ail_pushbuf); |
1da177e4 | 195 | IOP_PUSHBUF(lip); |
249a8c11 | 196 | last_pushed_lsn = lsn; |
1da177e4 LT |
197 | break; |
198 | ||
249a8c11 | 199 | case XFS_ITEM_PINNED: |
1da177e4 | 200 | XFS_STATS_INC(xs_push_ail_pinned); |
249a8c11 | 201 | stuck++; |
1da177e4 LT |
202 | flush_log = 1; |
203 | break; | |
204 | ||
249a8c11 | 205 | case XFS_ITEM_LOCKED: |
1da177e4 | 206 | XFS_STATS_INC(xs_push_ail_locked); |
249a8c11 DC |
207 | last_pushed_lsn = lsn; |
208 | stuck++; | |
1da177e4 LT |
209 | break; |
210 | ||
249a8c11 | 211 | case XFS_ITEM_FLUSHING: |
1da177e4 | 212 | XFS_STATS_INC(xs_push_ail_flushing); |
249a8c11 DC |
213 | last_pushed_lsn = lsn; |
214 | stuck++; | |
1da177e4 LT |
215 | break; |
216 | ||
249a8c11 | 217 | default: |
1da177e4 LT |
218 | ASSERT(0); |
219 | break; | |
220 | } | |
221 | ||
249a8c11 DC |
222 | spin_lock(&mp->m_ail_lock); |
223 | /* should we bother continuing? */ | |
224 | if (XFS_FORCED_SHUTDOWN(mp)) | |
1da177e4 | 225 | break; |
249a8c11 DC |
226 | ASSERT(mp->m_log); |
227 | ||
228 | count++; | |
1da177e4 | 229 | |
249a8c11 DC |
230 | /* |
231 | * Are there too many items we can't do anything with? | |
232 | * If we we are skipping too many items because we can't flush | |
233 | * them or they are already being flushed, we back off and | |
234 | * given them time to complete whatever operation is being | |
235 | * done. i.e. remove pressure from the AIL while we can't make | |
236 | * progress so traversals don't slow down further inserts and | |
237 | * removals to/from the AIL. | |
238 | * | |
239 | * The value of 100 is an arbitrary magic number based on | |
240 | * observation. | |
241 | */ | |
242 | if (stuck > 100) | |
243 | break; | |
244 | ||
245 | lip = xfs_trans_next_ail(mp, lip, &gen, &restarts); | |
246 | if (lip == NULL) | |
247 | break; | |
248 | if (restarts > XFS_TRANS_PUSH_AIL_RESTARTS) | |
249 | break; | |
250 | lsn = lip->li_lsn; | |
1da177e4 | 251 | } |
249a8c11 | 252 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
253 | |
254 | if (flush_log) { | |
255 | /* | |
256 | * If something we need to push out was pinned, then | |
257 | * push out the log so it will become unpinned and | |
258 | * move forward in the AIL. | |
259 | */ | |
1da177e4 LT |
260 | XFS_STATS_INC(xs_push_ail_flush); |
261 | xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE); | |
1da177e4 LT |
262 | } |
263 | ||
249a8c11 DC |
264 | /* |
265 | * We reached the target so wait a bit longer for I/O to complete and | |
266 | * remove pushed items from the AIL before we start the next scan from | |
267 | * the start of the AIL. | |
268 | */ | |
269 | if ((XFS_LSN_CMP(lsn, target) >= 0)) { | |
270 | tout += 20; | |
271 | last_pushed_lsn = 0; | |
272 | } else if ((restarts > XFS_TRANS_PUSH_AIL_RESTARTS) || | |
273 | (count && ((stuck * 100) / count > 90))) { | |
274 | /* | |
275 | * Either there is a lot of contention on the AIL or we | |
276 | * are stuck due to operations in progress. "Stuck" in this | |
277 | * case is defined as >90% of the items we tried to push | |
278 | * were stuck. | |
279 | * | |
280 | * Backoff a bit more to allow some I/O to complete before | |
281 | * continuing from where we were. | |
282 | */ | |
283 | tout += 10; | |
1da177e4 | 284 | } |
249a8c11 DC |
285 | out: |
286 | *last_lsn = last_pushed_lsn; | |
287 | return tout; | |
288 | } /* xfsaild_push */ | |
1da177e4 LT |
289 | |
290 | ||
291 | /* | |
292 | * This is to be called when an item is unlocked that may have | |
293 | * been in the AIL. It will wake up the first member of the AIL | |
294 | * wait list if this item's unlocking might allow it to progress. | |
295 | * If the item is in the AIL, then we need to get the AIL lock | |
296 | * while doing our checking so we don't race with someone going | |
297 | * to sleep waiting for this event in xfs_trans_push_ail(). | |
298 | */ | |
299 | void | |
300 | xfs_trans_unlocked_item( | |
301 | xfs_mount_t *mp, | |
302 | xfs_log_item_t *lip) | |
303 | { | |
304 | xfs_log_item_t *min_lip; | |
305 | ||
306 | /* | |
307 | * If we're forcibly shutting down, we may have | |
308 | * unlocked log items arbitrarily. The last thing | |
309 | * we want to do is to move the tail of the log | |
310 | * over some potentially valid data. | |
311 | */ | |
312 | if (!(lip->li_flags & XFS_LI_IN_AIL) || | |
313 | XFS_FORCED_SHUTDOWN(mp)) { | |
314 | return; | |
315 | } | |
316 | ||
317 | /* | |
318 | * This is the one case where we can call into xfs_ail_min() | |
319 | * without holding the AIL lock because we only care about the | |
320 | * case where we are at the tail of the AIL. If the object isn't | |
321 | * at the tail, it doesn't matter what result we get back. This | |
322 | * is slightly racy because since we were just unlocked, we could | |
323 | * go to sleep between the call to xfs_ail_min and the call to | |
324 | * xfs_log_move_tail, have someone else lock us, commit to us disk, | |
325 | * move us out of the tail of the AIL, and then we wake up. However, | |
326 | * the call to xfs_log_move_tail() doesn't do anything if there's | |
327 | * not enough free space to wake people up so we're safe calling it. | |
328 | */ | |
249a8c11 | 329 | min_lip = xfs_ail_min(&mp->m_ail.xa_ail); |
1da177e4 LT |
330 | |
331 | if (min_lip == lip) | |
332 | xfs_log_move_tail(mp, 1); | |
333 | } /* xfs_trans_unlocked_item */ | |
334 | ||
335 | ||
336 | /* | |
337 | * Update the position of the item in the AIL with the new | |
338 | * lsn. If it is not yet in the AIL, add it. Otherwise, move | |
339 | * it to its new position by removing it and re-adding it. | |
340 | * | |
341 | * Wakeup anyone with an lsn less than the item's lsn. If the item | |
342 | * we move in the AIL is the minimum one, update the tail lsn in the | |
343 | * log manager. | |
344 | * | |
345 | * Increment the AIL's generation count to indicate that the tree | |
346 | * has changed. | |
347 | * | |
348 | * This function must be called with the AIL lock held. The lock | |
287f3dad | 349 | * is dropped before returning. |
1da177e4 LT |
350 | */ |
351 | void | |
352 | xfs_trans_update_ail( | |
353 | xfs_mount_t *mp, | |
354 | xfs_log_item_t *lip, | |
287f3dad | 355 | xfs_lsn_t lsn) __releases(mp->m_ail_lock) |
1da177e4 LT |
356 | { |
357 | xfs_ail_entry_t *ailp; | |
358 | xfs_log_item_t *dlip=NULL; | |
359 | xfs_log_item_t *mlip; /* ptr to minimum lip */ | |
360 | ||
249a8c11 | 361 | ailp = &(mp->m_ail.xa_ail); |
1da177e4 LT |
362 | mlip = xfs_ail_min(ailp); |
363 | ||
364 | if (lip->li_flags & XFS_LI_IN_AIL) { | |
365 | dlip = xfs_ail_delete(ailp, lip); | |
366 | ASSERT(dlip == lip); | |
367 | } else { | |
368 | lip->li_flags |= XFS_LI_IN_AIL; | |
369 | } | |
370 | ||
371 | lip->li_lsn = lsn; | |
372 | ||
373 | xfs_ail_insert(ailp, lip); | |
249a8c11 | 374 | mp->m_ail.xa_gen++; |
1da177e4 LT |
375 | |
376 | if (mlip == dlip) { | |
249a8c11 | 377 | mlip = xfs_ail_min(&(mp->m_ail.xa_ail)); |
287f3dad | 378 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
379 | xfs_log_move_tail(mp, mlip->li_lsn); |
380 | } else { | |
287f3dad | 381 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
382 | } |
383 | ||
384 | ||
385 | } /* xfs_trans_update_ail */ | |
386 | ||
387 | /* | |
388 | * Delete the given item from the AIL. It must already be in | |
389 | * the AIL. | |
390 | * | |
391 | * Wakeup anyone with an lsn less than item's lsn. If the item | |
392 | * we delete in the AIL is the minimum one, update the tail lsn in the | |
393 | * log manager. | |
394 | * | |
395 | * Clear the IN_AIL flag from the item, reset its lsn to 0, and | |
396 | * bump the AIL's generation count to indicate that the tree | |
397 | * has changed. | |
398 | * | |
399 | * This function must be called with the AIL lock held. The lock | |
287f3dad | 400 | * is dropped before returning. |
1da177e4 LT |
401 | */ |
402 | void | |
403 | xfs_trans_delete_ail( | |
404 | xfs_mount_t *mp, | |
287f3dad | 405 | xfs_log_item_t *lip) __releases(mp->m_ail_lock) |
1da177e4 LT |
406 | { |
407 | xfs_ail_entry_t *ailp; | |
408 | xfs_log_item_t *dlip; | |
409 | xfs_log_item_t *mlip; | |
410 | ||
411 | if (lip->li_flags & XFS_LI_IN_AIL) { | |
249a8c11 | 412 | ailp = &(mp->m_ail.xa_ail); |
1da177e4 LT |
413 | mlip = xfs_ail_min(ailp); |
414 | dlip = xfs_ail_delete(ailp, lip); | |
415 | ASSERT(dlip == lip); | |
416 | ||
417 | ||
418 | lip->li_flags &= ~XFS_LI_IN_AIL; | |
419 | lip->li_lsn = 0; | |
249a8c11 | 420 | mp->m_ail.xa_gen++; |
1da177e4 LT |
421 | |
422 | if (mlip == dlip) { | |
249a8c11 | 423 | mlip = xfs_ail_min(&(mp->m_ail.xa_ail)); |
287f3dad | 424 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
425 | xfs_log_move_tail(mp, (mlip ? mlip->li_lsn : 0)); |
426 | } else { | |
287f3dad | 427 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
428 | } |
429 | } | |
430 | else { | |
431 | /* | |
432 | * If the file system is not being shutdown, we are in | |
433 | * serious trouble if we get to this stage. | |
434 | */ | |
435 | if (XFS_FORCED_SHUTDOWN(mp)) | |
287f3dad | 436 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
437 | else { |
438 | xfs_cmn_err(XFS_PTAG_AILDELETE, CE_ALERT, mp, | |
7d04a335 NS |
439 | "%s: attempting to delete a log item that is not in the AIL", |
440 | __FUNCTION__); | |
287f3dad | 441 | spin_unlock(&mp->m_ail_lock); |
7d04a335 | 442 | xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); |
1da177e4 LT |
443 | } |
444 | } | |
445 | } | |
446 | ||
447 | ||
448 | ||
449 | /* | |
450 | * Return the item in the AIL with the smallest lsn. | |
451 | * Return the current tree generation number for use | |
452 | * in calls to xfs_trans_next_ail(). | |
453 | */ | |
454 | xfs_log_item_t * | |
455 | xfs_trans_first_ail( | |
456 | xfs_mount_t *mp, | |
457 | int *gen) | |
458 | { | |
459 | xfs_log_item_t *lip; | |
460 | ||
249a8c11 DC |
461 | lip = xfs_ail_min(&(mp->m_ail.xa_ail)); |
462 | *gen = (int)mp->m_ail.xa_gen; | |
1da177e4 | 463 | |
249a8c11 | 464 | return lip; |
1da177e4 LT |
465 | } |
466 | ||
467 | /* | |
468 | * If the generation count of the tree has not changed since the | |
469 | * caller last took something from the AIL, then return the elmt | |
470 | * in the tree which follows the one given. If the count has changed, | |
471 | * then return the minimum elmt of the AIL and bump the restarts counter | |
472 | * if one is given. | |
473 | */ | |
474 | xfs_log_item_t * | |
475 | xfs_trans_next_ail( | |
476 | xfs_mount_t *mp, | |
477 | xfs_log_item_t *lip, | |
478 | int *gen, | |
479 | int *restarts) | |
480 | { | |
481 | xfs_log_item_t *nlip; | |
482 | ||
483 | ASSERT(mp && lip && gen); | |
249a8c11 DC |
484 | if (mp->m_ail.xa_gen == *gen) { |
485 | nlip = xfs_ail_next(&(mp->m_ail.xa_ail), lip); | |
1da177e4 | 486 | } else { |
249a8c11 DC |
487 | nlip = xfs_ail_min(&(mp->m_ail).xa_ail); |
488 | *gen = (int)mp->m_ail.xa_gen; | |
1da177e4 LT |
489 | if (restarts != NULL) { |
490 | XFS_STATS_INC(xs_push_ail_restarts); | |
491 | (*restarts)++; | |
492 | } | |
493 | } | |
494 | ||
495 | return (nlip); | |
496 | } | |
497 | ||
498 | ||
499 | /* | |
500 | * The active item list (AIL) is a doubly linked list of log | |
501 | * items sorted by ascending lsn. The base of the list is | |
502 | * a forw/back pointer pair embedded in the xfs mount structure. | |
503 | * The base is initialized with both pointers pointing to the | |
504 | * base. This case always needs to be distinguished, because | |
505 | * the base has no lsn to look at. We almost always insert | |
506 | * at the end of the list, so on inserts we search from the | |
507 | * end of the list to find where the new item belongs. | |
508 | */ | |
509 | ||
510 | /* | |
511 | * Initialize the doubly linked list to point only to itself. | |
512 | */ | |
249a8c11 | 513 | int |
1da177e4 LT |
514 | xfs_trans_ail_init( |
515 | xfs_mount_t *mp) | |
516 | { | |
249a8c11 DC |
517 | mp->m_ail.xa_ail.ail_forw = (xfs_log_item_t*)&mp->m_ail.xa_ail; |
518 | mp->m_ail.xa_ail.ail_back = (xfs_log_item_t*)&mp->m_ail.xa_ail; | |
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( | |
537 | xfs_ail_entry_t *base, | |
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 | */ | |
546 | if (base->ail_back == (xfs_log_item_t*)base) { | |
547 | base->ail_forw = lip; | |
548 | base->ail_back = lip; | |
549 | lip->li_ail.ail_forw = (xfs_log_item_t*)base; | |
550 | lip->li_ail.ail_back = (xfs_log_item_t*)base; | |
551 | return; | |
552 | } | |
553 | ||
554 | next_lip = base->ail_back; | |
555 | while ((next_lip != (xfs_log_item_t*)base) && | |
556 | (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) > 0)) { | |
557 | next_lip = next_lip->li_ail.ail_back; | |
558 | } | |
559 | ASSERT((next_lip == (xfs_log_item_t*)base) || | |
560 | (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0)); | |
561 | lip->li_ail.ail_forw = next_lip->li_ail.ail_forw; | |
562 | lip->li_ail.ail_back = next_lip; | |
563 | next_lip->li_ail.ail_forw = lip; | |
564 | lip->li_ail.ail_forw->li_ail.ail_back = lip; | |
565 | ||
566 | xfs_ail_check(base); | |
567 | return; | |
568 | } | |
569 | ||
570 | /* | |
571 | * Delete the given item from the AIL. Return a pointer to the item. | |
572 | */ | |
573 | /*ARGSUSED*/ | |
574 | STATIC xfs_log_item_t * | |
575 | xfs_ail_delete( | |
576 | xfs_ail_entry_t *base, | |
577 | xfs_log_item_t *lip) | |
578 | /* ARGSUSED */ | |
579 | { | |
580 | lip->li_ail.ail_forw->li_ail.ail_back = lip->li_ail.ail_back; | |
581 | lip->li_ail.ail_back->li_ail.ail_forw = lip->li_ail.ail_forw; | |
582 | lip->li_ail.ail_forw = NULL; | |
583 | lip->li_ail.ail_back = NULL; | |
584 | ||
585 | xfs_ail_check(base); | |
586 | return lip; | |
587 | } | |
588 | ||
589 | /* | |
590 | * Return a pointer to the first item in the AIL. | |
591 | * If the AIL is empty, then return NULL. | |
592 | */ | |
593 | STATIC xfs_log_item_t * | |
594 | xfs_ail_min( | |
595 | xfs_ail_entry_t *base) | |
596 | /* ARGSUSED */ | |
597 | { | |
598 | register xfs_log_item_t *forw = base->ail_forw; | |
599 | if (forw == (xfs_log_item_t*)base) { | |
600 | return NULL; | |
601 | } | |
602 | return forw; | |
603 | } | |
604 | ||
605 | /* | |
606 | * Return a pointer to the item which follows | |
607 | * the given item in the AIL. If the given item | |
608 | * is the last item in the list, then return NULL. | |
609 | */ | |
610 | STATIC xfs_log_item_t * | |
611 | xfs_ail_next( | |
612 | xfs_ail_entry_t *base, | |
613 | xfs_log_item_t *lip) | |
614 | /* ARGSUSED */ | |
615 | { | |
616 | if (lip->li_ail.ail_forw == (xfs_log_item_t*)base) { | |
617 | return NULL; | |
618 | } | |
619 | return lip->li_ail.ail_forw; | |
620 | ||
621 | } | |
622 | ||
623 | #ifdef DEBUG | |
624 | /* | |
625 | * Check that the list is sorted as it should be. | |
626 | */ | |
627 | STATIC void | |
628 | xfs_ail_check( | |
629 | xfs_ail_entry_t *base) | |
630 | { | |
631 | xfs_log_item_t *lip; | |
632 | xfs_log_item_t *prev_lip; | |
633 | ||
634 | lip = base->ail_forw; | |
635 | if (lip == (xfs_log_item_t*)base) { | |
636 | /* | |
637 | * Make sure the pointers are correct when the list | |
638 | * is empty. | |
639 | */ | |
640 | ASSERT(base->ail_back == (xfs_log_item_t*)base); | |
641 | return; | |
642 | } | |
643 | ||
644 | /* | |
645 | * Walk the list checking forward and backward pointers, | |
646 | * lsn ordering, and that every entry has the XFS_LI_IN_AIL | |
647 | * flag set. | |
648 | */ | |
649 | prev_lip = (xfs_log_item_t*)base; | |
650 | while (lip != (xfs_log_item_t*)base) { | |
651 | if (prev_lip != (xfs_log_item_t*)base) { | |
652 | ASSERT(prev_lip->li_ail.ail_forw == lip); | |
653 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0); | |
654 | } | |
655 | ASSERT(lip->li_ail.ail_back == prev_lip); | |
656 | ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0); | |
657 | prev_lip = lip; | |
658 | lip = lip->li_ail.ail_forw; | |
659 | } | |
660 | ASSERT(lip == (xfs_log_item_t*)base); | |
661 | ASSERT(base->ail_back == prev_lip); | |
662 | } | |
663 | #endif /* DEBUG */ |