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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 | ||
82fa9012 DC |
31 | STATIC void xfs_ail_insert(struct xfs_ail *, xfs_log_item_t *); |
32 | STATIC xfs_log_item_t * xfs_ail_delete(struct xfs_ail *, xfs_log_item_t *); | |
33 | STATIC xfs_log_item_t * xfs_ail_min(struct xfs_ail *); | |
34 | STATIC xfs_log_item_t * xfs_ail_next(struct xfs_ail *, xfs_log_item_t *); | |
1da177e4 LT |
35 | |
36 | #ifdef DEBUG | |
82fa9012 | 37 | STATIC void xfs_ail_check(struct xfs_ail *, 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); |
82fa9012 | 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 | |
82fa9012 | 94 | lip = xfs_ail_min(mp->m_ail); |
249a8c11 | 95 | if (lip && !XFS_FORCED_SHUTDOWN(mp)) { |
82fa9012 DC |
96 | if (XFS_LSN_CMP(threshold_lsn, mp->m_ail->xa_target) > 0) |
97 | xfsaild_wakeup(mp->m_ail, threshold_lsn); | |
249a8c11 DC |
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 | ||
82fa9012 DC |
114 | lip = xfs_ail_min(mp->m_ail); |
115 | *gen = (int)mp->m_ail->xa_gen; | |
249a8c11 DC |
116 | if (lsn == 0) |
117 | return lip; | |
118 | ||
82fa9012 | 119 | list_for_each_entry(lip, &mp->m_ail->xa_ail, li_ail) { |
535f6b37 JJS |
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( | |
82fa9012 | 132 | struct xfs_ail *ailp, |
249a8c11 DC |
133 | xfs_lsn_t *last_lsn) |
134 | { | |
135 | long tout = 1000; /* milliseconds */ | |
136 | xfs_lsn_t last_pushed_lsn = *last_lsn; | |
82fa9012 | 137 | xfs_lsn_t target = ailp->xa_target; |
249a8c11 DC |
138 | xfs_lsn_t lsn; |
139 | xfs_log_item_t *lip; | |
140 | int gen; | |
141 | int restarts; | |
142 | int flush_log, count, stuck; | |
82fa9012 | 143 | xfs_mount_t *mp = ailp->xa_mount; |
249a8c11 DC |
144 | |
145 | #define XFS_TRANS_PUSH_AIL_RESTARTS 10 | |
1da177e4 | 146 | |
287f3dad | 147 | spin_lock(&mp->m_ail_lock); |
249a8c11 DC |
148 | lip = xfs_trans_first_push_ail(mp, &gen, *last_lsn); |
149 | if (!lip || XFS_FORCED_SHUTDOWN(mp)) { | |
1da177e4 | 150 | /* |
249a8c11 | 151 | * AIL is empty or our push has reached the end. |
1da177e4 | 152 | */ |
287f3dad | 153 | spin_unlock(&mp->m_ail_lock); |
249a8c11 DC |
154 | last_pushed_lsn = 0; |
155 | goto out; | |
1da177e4 LT |
156 | } |
157 | ||
158 | XFS_STATS_INC(xs_push_ail); | |
159 | ||
160 | /* | |
161 | * While the item we are looking at is below the given threshold | |
249a8c11 | 162 | * try to flush it out. We'd like not to stop until we've at least |
1da177e4 | 163 | * tried to push on everything in the AIL with an LSN less than |
249a8c11 DC |
164 | * the given threshold. |
165 | * | |
166 | * However, we will stop after a certain number of pushes and wait | |
167 | * for a reduced timeout to fire before pushing further. This | |
168 | * prevents use from spinning when we can't do anything or there is | |
169 | * lots of contention on the AIL lists. | |
1da177e4 | 170 | */ |
249a8c11 DC |
171 | tout = 10; |
172 | lsn = lip->li_lsn; | |
173 | flush_log = stuck = count = restarts = 0; | |
174 | while ((XFS_LSN_CMP(lip->li_lsn, target) < 0)) { | |
175 | int lock_result; | |
1da177e4 | 176 | /* |
249a8c11 DC |
177 | * If we can lock the item without sleeping, unlock the AIL |
178 | * lock and flush the item. Then re-grab the AIL lock so we | |
179 | * can look for the next item on the AIL. List changes are | |
180 | * handled by the AIL lookup functions internally | |
1da177e4 | 181 | * |
249a8c11 DC |
182 | * If we can't lock the item, either its holder will flush it |
183 | * or it is already being flushed or it is being relogged. In | |
184 | * any of these case it is being taken care of and we can just | |
185 | * skip to the next item in the list. | |
1da177e4 LT |
186 | */ |
187 | lock_result = IOP_TRYLOCK(lip); | |
249a8c11 | 188 | spin_unlock(&mp->m_ail_lock); |
1da177e4 | 189 | switch (lock_result) { |
249a8c11 | 190 | case XFS_ITEM_SUCCESS: |
1da177e4 LT |
191 | XFS_STATS_INC(xs_push_ail_success); |
192 | IOP_PUSH(lip); | |
249a8c11 | 193 | last_pushed_lsn = lsn; |
1da177e4 LT |
194 | break; |
195 | ||
249a8c11 | 196 | case XFS_ITEM_PUSHBUF: |
1da177e4 | 197 | XFS_STATS_INC(xs_push_ail_pushbuf); |
1da177e4 | 198 | IOP_PUSHBUF(lip); |
249a8c11 | 199 | last_pushed_lsn = lsn; |
1da177e4 LT |
200 | break; |
201 | ||
249a8c11 | 202 | case XFS_ITEM_PINNED: |
1da177e4 | 203 | XFS_STATS_INC(xs_push_ail_pinned); |
249a8c11 | 204 | stuck++; |
1da177e4 LT |
205 | flush_log = 1; |
206 | break; | |
207 | ||
249a8c11 | 208 | case XFS_ITEM_LOCKED: |
1da177e4 | 209 | XFS_STATS_INC(xs_push_ail_locked); |
249a8c11 DC |
210 | last_pushed_lsn = lsn; |
211 | stuck++; | |
1da177e4 LT |
212 | break; |
213 | ||
249a8c11 | 214 | case XFS_ITEM_FLUSHING: |
1da177e4 | 215 | XFS_STATS_INC(xs_push_ail_flushing); |
249a8c11 DC |
216 | last_pushed_lsn = lsn; |
217 | stuck++; | |
1da177e4 LT |
218 | break; |
219 | ||
249a8c11 | 220 | default: |
1da177e4 LT |
221 | ASSERT(0); |
222 | break; | |
223 | } | |
224 | ||
249a8c11 DC |
225 | spin_lock(&mp->m_ail_lock); |
226 | /* should we bother continuing? */ | |
227 | if (XFS_FORCED_SHUTDOWN(mp)) | |
1da177e4 | 228 | break; |
249a8c11 DC |
229 | ASSERT(mp->m_log); |
230 | ||
231 | count++; | |
1da177e4 | 232 | |
249a8c11 DC |
233 | /* |
234 | * Are there too many items we can't do anything with? | |
235 | * If we we are skipping too many items because we can't flush | |
236 | * them or they are already being flushed, we back off and | |
237 | * given them time to complete whatever operation is being | |
238 | * done. i.e. remove pressure from the AIL while we can't make | |
239 | * progress so traversals don't slow down further inserts and | |
240 | * removals to/from the AIL. | |
241 | * | |
242 | * The value of 100 is an arbitrary magic number based on | |
243 | * observation. | |
244 | */ | |
245 | if (stuck > 100) | |
246 | break; | |
247 | ||
248 | lip = xfs_trans_next_ail(mp, lip, &gen, &restarts); | |
249 | if (lip == NULL) | |
250 | break; | |
251 | if (restarts > XFS_TRANS_PUSH_AIL_RESTARTS) | |
252 | break; | |
253 | lsn = lip->li_lsn; | |
1da177e4 | 254 | } |
249a8c11 | 255 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
256 | |
257 | if (flush_log) { | |
258 | /* | |
259 | * If something we need to push out was pinned, then | |
260 | * push out the log so it will become unpinned and | |
261 | * move forward in the AIL. | |
262 | */ | |
1da177e4 LT |
263 | XFS_STATS_INC(xs_push_ail_flush); |
264 | xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE); | |
1da177e4 LT |
265 | } |
266 | ||
92d9cd10 DC |
267 | if (!count) { |
268 | /* We're past our target or empty, so idle */ | |
269 | tout = 1000; | |
270 | } else if (XFS_LSN_CMP(lsn, target) >= 0) { | |
271 | /* | |
272 | * We reached the target so wait a bit longer for I/O to | |
273 | * complete and remove pushed items from the AIL before we | |
274 | * start the next scan from the start of the AIL. | |
275 | */ | |
249a8c11 DC |
276 | tout += 20; |
277 | last_pushed_lsn = 0; | |
278 | } else if ((restarts > XFS_TRANS_PUSH_AIL_RESTARTS) || | |
92d9cd10 | 279 | ((stuck * 100) / count > 90)) { |
249a8c11 DC |
280 | /* |
281 | * Either there is a lot of contention on the AIL or we | |
282 | * are stuck due to operations in progress. "Stuck" in this | |
283 | * case is defined as >90% of the items we tried to push | |
284 | * were stuck. | |
285 | * | |
286 | * Backoff a bit more to allow some I/O to complete before | |
287 | * continuing from where we were. | |
288 | */ | |
289 | tout += 10; | |
1da177e4 | 290 | } |
249a8c11 DC |
291 | out: |
292 | *last_lsn = last_pushed_lsn; | |
293 | return tout; | |
294 | } /* xfsaild_push */ | |
1da177e4 LT |
295 | |
296 | ||
297 | /* | |
298 | * This is to be called when an item is unlocked that may have | |
299 | * been in the AIL. It will wake up the first member of the AIL | |
300 | * wait list if this item's unlocking might allow it to progress. | |
301 | * If the item is in the AIL, then we need to get the AIL lock | |
302 | * while doing our checking so we don't race with someone going | |
303 | * to sleep waiting for this event in xfs_trans_push_ail(). | |
304 | */ | |
305 | void | |
306 | xfs_trans_unlocked_item( | |
307 | xfs_mount_t *mp, | |
308 | xfs_log_item_t *lip) | |
309 | { | |
310 | xfs_log_item_t *min_lip; | |
311 | ||
312 | /* | |
313 | * If we're forcibly shutting down, we may have | |
314 | * unlocked log items arbitrarily. The last thing | |
315 | * we want to do is to move the tail of the log | |
316 | * over some potentially valid data. | |
317 | */ | |
318 | if (!(lip->li_flags & XFS_LI_IN_AIL) || | |
319 | XFS_FORCED_SHUTDOWN(mp)) { | |
320 | return; | |
321 | } | |
322 | ||
323 | /* | |
324 | * This is the one case where we can call into xfs_ail_min() | |
325 | * without holding the AIL lock because we only care about the | |
326 | * case where we are at the tail of the AIL. If the object isn't | |
327 | * at the tail, it doesn't matter what result we get back. This | |
328 | * is slightly racy because since we were just unlocked, we could | |
329 | * go to sleep between the call to xfs_ail_min and the call to | |
330 | * xfs_log_move_tail, have someone else lock us, commit to us disk, | |
331 | * move us out of the tail of the AIL, and then we wake up. However, | |
332 | * the call to xfs_log_move_tail() doesn't do anything if there's | |
333 | * not enough free space to wake people up so we're safe calling it. | |
334 | */ | |
82fa9012 | 335 | min_lip = xfs_ail_min(mp->m_ail); |
1da177e4 LT |
336 | |
337 | if (min_lip == lip) | |
338 | xfs_log_move_tail(mp, 1); | |
339 | } /* xfs_trans_unlocked_item */ | |
340 | ||
341 | ||
342 | /* | |
343 | * Update the position of the item in the AIL with the new | |
344 | * lsn. If it is not yet in the AIL, add it. Otherwise, move | |
345 | * it to its new position by removing it and re-adding it. | |
346 | * | |
347 | * Wakeup anyone with an lsn less than the item's lsn. If the item | |
348 | * we move in the AIL is the minimum one, update the tail lsn in the | |
349 | * log manager. | |
350 | * | |
351 | * Increment the AIL's generation count to indicate that the tree | |
352 | * has changed. | |
353 | * | |
354 | * This function must be called with the AIL lock held. The lock | |
287f3dad | 355 | * is dropped before returning. |
1da177e4 LT |
356 | */ |
357 | void | |
358 | xfs_trans_update_ail( | |
359 | xfs_mount_t *mp, | |
360 | xfs_log_item_t *lip, | |
287f3dad | 361 | xfs_lsn_t lsn) __releases(mp->m_ail_lock) |
1da177e4 | 362 | { |
1da177e4 LT |
363 | xfs_log_item_t *dlip=NULL; |
364 | xfs_log_item_t *mlip; /* ptr to minimum lip */ | |
365 | ||
82fa9012 | 366 | mlip = xfs_ail_min(mp->m_ail); |
1da177e4 LT |
367 | |
368 | if (lip->li_flags & XFS_LI_IN_AIL) { | |
82fa9012 | 369 | dlip = xfs_ail_delete(mp->m_ail, lip); |
1da177e4 LT |
370 | ASSERT(dlip == lip); |
371 | } else { | |
372 | lip->li_flags |= XFS_LI_IN_AIL; | |
373 | } | |
374 | ||
375 | lip->li_lsn = lsn; | |
376 | ||
82fa9012 DC |
377 | xfs_ail_insert(mp->m_ail, lip); |
378 | mp->m_ail->xa_gen++; | |
1da177e4 LT |
379 | |
380 | if (mlip == dlip) { | |
82fa9012 | 381 | mlip = xfs_ail_min(mp->m_ail); |
287f3dad | 382 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
383 | xfs_log_move_tail(mp, mlip->li_lsn); |
384 | } else { | |
287f3dad | 385 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
386 | } |
387 | ||
388 | ||
389 | } /* xfs_trans_update_ail */ | |
390 | ||
391 | /* | |
392 | * Delete the given item from the AIL. It must already be in | |
393 | * the AIL. | |
394 | * | |
395 | * Wakeup anyone with an lsn less than item's lsn. If the item | |
396 | * we delete in the AIL is the minimum one, update the tail lsn in the | |
397 | * log manager. | |
398 | * | |
399 | * Clear the IN_AIL flag from the item, reset its lsn to 0, and | |
400 | * bump the AIL's generation count to indicate that the tree | |
401 | * has changed. | |
402 | * | |
403 | * This function must be called with the AIL lock held. The lock | |
287f3dad | 404 | * is dropped before returning. |
1da177e4 LT |
405 | */ |
406 | void | |
407 | xfs_trans_delete_ail( | |
408 | xfs_mount_t *mp, | |
287f3dad | 409 | xfs_log_item_t *lip) __releases(mp->m_ail_lock) |
1da177e4 | 410 | { |
1da177e4 LT |
411 | xfs_log_item_t *dlip; |
412 | xfs_log_item_t *mlip; | |
413 | ||
414 | if (lip->li_flags & XFS_LI_IN_AIL) { | |
82fa9012 DC |
415 | mlip = xfs_ail_min(mp->m_ail); |
416 | dlip = xfs_ail_delete(mp->m_ail, lip); | |
1da177e4 LT |
417 | ASSERT(dlip == lip); |
418 | ||
419 | ||
420 | lip->li_flags &= ~XFS_LI_IN_AIL; | |
421 | lip->li_lsn = 0; | |
82fa9012 | 422 | mp->m_ail->xa_gen++; |
1da177e4 LT |
423 | |
424 | if (mlip == dlip) { | |
82fa9012 | 425 | mlip = xfs_ail_min(mp->m_ail); |
287f3dad | 426 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
427 | xfs_log_move_tail(mp, (mlip ? mlip->li_lsn : 0)); |
428 | } else { | |
287f3dad | 429 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
430 | } |
431 | } | |
432 | else { | |
433 | /* | |
434 | * If the file system is not being shutdown, we are in | |
435 | * serious trouble if we get to this stage. | |
436 | */ | |
437 | if (XFS_FORCED_SHUTDOWN(mp)) | |
287f3dad | 438 | spin_unlock(&mp->m_ail_lock); |
1da177e4 LT |
439 | else { |
440 | xfs_cmn_err(XFS_PTAG_AILDELETE, CE_ALERT, mp, | |
7d04a335 | 441 | "%s: attempting to delete a log item that is not in the AIL", |
34a622b2 | 442 | __func__); |
287f3dad | 443 | spin_unlock(&mp->m_ail_lock); |
7d04a335 | 444 | xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); |
1da177e4 LT |
445 | } |
446 | } | |
447 | } | |
448 | ||
449 | ||
450 | ||
451 | /* | |
452 | * Return the item in the AIL with the smallest lsn. | |
453 | * Return the current tree generation number for use | |
454 | * in calls to xfs_trans_next_ail(). | |
455 | */ | |
456 | xfs_log_item_t * | |
457 | xfs_trans_first_ail( | |
458 | xfs_mount_t *mp, | |
459 | int *gen) | |
460 | { | |
461 | xfs_log_item_t *lip; | |
462 | ||
82fa9012 DC |
463 | lip = xfs_ail_min(mp->m_ail); |
464 | *gen = (int)mp->m_ail->xa_gen; | |
1da177e4 | 465 | |
249a8c11 | 466 | return lip; |
1da177e4 LT |
467 | } |
468 | ||
469 | /* | |
470 | * If the generation count of the tree has not changed since the | |
471 | * caller last took something from the AIL, then return the elmt | |
472 | * in the tree which follows the one given. If the count has changed, | |
473 | * then return the minimum elmt of the AIL and bump the restarts counter | |
474 | * if one is given. | |
475 | */ | |
476 | xfs_log_item_t * | |
477 | xfs_trans_next_ail( | |
478 | xfs_mount_t *mp, | |
479 | xfs_log_item_t *lip, | |
480 | int *gen, | |
481 | int *restarts) | |
482 | { | |
483 | xfs_log_item_t *nlip; | |
484 | ||
485 | ASSERT(mp && lip && gen); | |
82fa9012 DC |
486 | if (mp->m_ail->xa_gen == *gen) { |
487 | nlip = xfs_ail_next(mp->m_ail, lip); | |
1da177e4 | 488 | } else { |
82fa9012 DC |
489 | nlip = xfs_ail_min(mp->m_ail); |
490 | *gen = (int)mp->m_ail->xa_gen; | |
1da177e4 LT |
491 | if (restarts != NULL) { |
492 | XFS_STATS_INC(xs_push_ail_restarts); | |
493 | (*restarts)++; | |
494 | } | |
495 | } | |
496 | ||
497 | return (nlip); | |
498 | } | |
499 | ||
500 | ||
501 | /* | |
502 | * The active item list (AIL) is a doubly linked list of log | |
503 | * items sorted by ascending lsn. The base of the list is | |
504 | * a forw/back pointer pair embedded in the xfs mount structure. | |
505 | * The base is initialized with both pointers pointing to the | |
506 | * base. This case always needs to be distinguished, because | |
507 | * the base has no lsn to look at. We almost always insert | |
508 | * at the end of the list, so on inserts we search from the | |
509 | * end of the list to find where the new item belongs. | |
510 | */ | |
511 | ||
512 | /* | |
513 | * Initialize the doubly linked list to point only to itself. | |
514 | */ | |
249a8c11 | 515 | int |
1da177e4 LT |
516 | xfs_trans_ail_init( |
517 | xfs_mount_t *mp) | |
518 | { | |
82fa9012 DC |
519 | struct xfs_ail *ailp; |
520 | ||
521 | ailp = kmem_zalloc(sizeof(struct xfs_ail), KM_MAYFAIL); | |
522 | if (!ailp) | |
523 | return ENOMEM; | |
524 | ||
525 | ailp->xa_mount = mp; | |
526 | INIT_LIST_HEAD(&ailp->xa_ail); | |
527 | return xfsaild_start(ailp); | |
249a8c11 DC |
528 | } |
529 | ||
530 | void | |
531 | xfs_trans_ail_destroy( | |
532 | xfs_mount_t *mp) | |
533 | { | |
82fa9012 DC |
534 | struct xfs_ail *ailp = mp->m_ail; |
535 | ||
536 | xfsaild_stop(ailp); | |
537 | kmem_free(ailp); | |
1da177e4 LT |
538 | } |
539 | ||
540 | /* | |
541 | * Insert the given log item into the AIL. | |
542 | * We almost always insert at the end of the list, so on inserts | |
543 | * we search from the end of the list to find where the | |
544 | * new item belongs. | |
545 | */ | |
546 | STATIC void | |
547 | xfs_ail_insert( | |
82fa9012 | 548 | struct xfs_ail *ailp, |
1da177e4 LT |
549 | xfs_log_item_t *lip) |
550 | /* ARGSUSED */ | |
551 | { | |
552 | xfs_log_item_t *next_lip; | |
553 | ||
554 | /* | |
555 | * If the list is empty, just insert the item. | |
556 | */ | |
535f6b37 JJS |
557 | if (list_empty(&ailp->xa_ail)) { |
558 | list_add(&lip->li_ail, &ailp->xa_ail); | |
1da177e4 LT |
559 | return; |
560 | } | |
561 | ||
535f6b37 JJS |
562 | list_for_each_entry_reverse(next_lip, &ailp->xa_ail, li_ail) { |
563 | if (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0) | |
564 | break; | |
1da177e4 | 565 | } |
535f6b37 JJS |
566 | |
567 | ASSERT((&next_lip->li_ail == &ailp->xa_ail) || | |
1da177e4 | 568 | (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0)); |
1da177e4 | 569 | |
535f6b37 JJS |
570 | list_add(&lip->li_ail, &next_lip->li_ail); |
571 | ||
572 | xfs_ail_check(ailp, lip); | |
1da177e4 LT |
573 | return; |
574 | } | |
575 | ||
576 | /* | |
577 | * Delete the given item from the AIL. Return a pointer to the item. | |
578 | */ | |
579 | /*ARGSUSED*/ | |
580 | STATIC xfs_log_item_t * | |
581 | xfs_ail_delete( | |
82fa9012 | 582 | struct xfs_ail *ailp, |
1da177e4 LT |
583 | xfs_log_item_t *lip) |
584 | /* ARGSUSED */ | |
585 | { | |
535f6b37 JJS |
586 | xfs_ail_check(ailp, lip); |
587 | ||
588 | list_del(&lip->li_ail); | |
1da177e4 | 589 | |
1da177e4 LT |
590 | return lip; |
591 | } | |
592 | ||
593 | /* | |
594 | * Return a pointer to the first item in the AIL. | |
595 | * If the AIL is empty, then return NULL. | |
596 | */ | |
597 | STATIC xfs_log_item_t * | |
598 | xfs_ail_min( | |
82fa9012 | 599 | struct xfs_ail *ailp) |
1da177e4 LT |
600 | /* ARGSUSED */ |
601 | { | |
535f6b37 | 602 | if (list_empty(&ailp->xa_ail)) |
1da177e4 | 603 | return NULL; |
535f6b37 JJS |
604 | |
605 | return list_first_entry(&ailp->xa_ail, xfs_log_item_t, li_ail); | |
1da177e4 LT |
606 | } |
607 | ||
608 | /* | |
609 | * Return a pointer to the item which follows | |
610 | * the given item in the AIL. If the given item | |
611 | * is the last item in the list, then return NULL. | |
612 | */ | |
613 | STATIC xfs_log_item_t * | |
614 | xfs_ail_next( | |
82fa9012 | 615 | struct xfs_ail *ailp, |
1da177e4 LT |
616 | xfs_log_item_t *lip) |
617 | /* ARGSUSED */ | |
618 | { | |
535f6b37 | 619 | if (lip->li_ail.next == &ailp->xa_ail) |
1da177e4 | 620 | return NULL; |
1da177e4 | 621 | |
535f6b37 | 622 | return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail); |
1da177e4 LT |
623 | } |
624 | ||
625 | #ifdef DEBUG | |
626 | /* | |
627 | * Check that the list is sorted as it should be. | |
628 | */ | |
629 | STATIC void | |
630 | xfs_ail_check( | |
82fa9012 | 631 | struct xfs_ail *ailp, |
de08dbc1 | 632 | xfs_log_item_t *lip) |
1da177e4 | 633 | { |
1da177e4 LT |
634 | xfs_log_item_t *prev_lip; |
635 | ||
535f6b37 | 636 | if (list_empty(&ailp->xa_ail)) |
1da177e4 | 637 | return; |
1da177e4 | 638 | |
de08dbc1 DC |
639 | /* |
640 | * Check the next and previous entries are valid. | |
641 | */ | |
642 | ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0); | |
535f6b37 JJS |
643 | prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail); |
644 | if (&prev_lip->li_ail != &ailp->xa_ail) | |
de08dbc1 | 645 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0); |
535f6b37 JJS |
646 | |
647 | prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail); | |
648 | if (&prev_lip->li_ail != &ailp->xa_ail) | |
de08dbc1 | 649 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0); |
de08dbc1 DC |
650 | |
651 | ||
652 | #ifdef XFS_TRANS_DEBUG | |
1da177e4 | 653 | /* |
535f6b37 JJS |
654 | * Walk the list checking lsn ordering, and that every entry has the |
655 | * XFS_LI_IN_AIL flag set. This is really expensive, so only do it | |
656 | * when specifically debugging the transaction subsystem. | |
1da177e4 | 657 | */ |
535f6b37 JJS |
658 | prev_lip = list_entry(&ailp->xa_ail, xfs_log_item_t, li_ail); |
659 | list_for_each_entry(lip, &ailp->xa_ail, li_ail) { | |
660 | if (&prev_lip->li_ail != &ailp->xa_ail) | |
1da177e4 | 661 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0); |
1da177e4 LT |
662 | ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0); |
663 | prev_lip = lip; | |
1da177e4 | 664 | } |
de08dbc1 | 665 | #endif /* XFS_TRANS_DEBUG */ |
1da177e4 LT |
666 | } |
667 | #endif /* DEBUG */ |