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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Nathan Scott7b718762005-11-02 14:58:39 +11002 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
David Chinnerc7e8f262008-10-30 17:39:23 +11003 * Copyright (c) 2008 Dave Chinner
Nathan Scott7b718762005-11-02 14:58:39 +11004 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
Nathan Scott7b718762005-11-02 14:58:39 +11006 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * published by the Free Software Foundation.
9 *
Nathan Scott7b718762005-11-02 14:58:39 +110010 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070014 *
Nathan Scott7b718762005-11-02 14:58:39 +110015 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include "xfs.h"
Nathan Scotta844f452005-11-02 14:38:42 +110020#include "xfs_fs.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include "xfs_types.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include "xfs_log.h"
Nathan Scotta844f452005-11-02 14:38:42 +110023#include "xfs_inum.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include "xfs_trans.h"
25#include "xfs_sb.h"
David Chinnerda353b02007-08-28 14:00:13 +100026#include "xfs_ag.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include "xfs_dmapi.h"
28#include "xfs_mount.h"
29#include "xfs_trans_priv.h"
30#include "xfs_error.h"
31
David Chinner82fa9012008-10-30 17:38:26 +110032STATIC void xfs_ail_insert(struct xfs_ail *, xfs_log_item_t *);
33STATIC xfs_log_item_t * xfs_ail_delete(struct xfs_ail *, xfs_log_item_t *);
34STATIC xfs_log_item_t * xfs_ail_min(struct xfs_ail *);
35STATIC xfs_log_item_t * xfs_ail_next(struct xfs_ail *, xfs_log_item_t *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
37#ifdef DEBUG
David Chinner82fa9012008-10-30 17:38:26 +110038STATIC void xfs_ail_check(struct xfs_ail *, xfs_log_item_t *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#else
David Chinnerde08dbc2008-02-05 12:13:38 +110040#define xfs_ail_check(a,l)
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#endif /* DEBUG */
42
43
44/*
45 * This is called by the log manager code to determine the LSN
46 * of the tail of the log. This is exactly the LSN of the first
47 * item in the AIL. If the AIL is empty, then this function
48 * returns 0.
49 *
50 * We need the AIL lock in order to get a coherent read of the
51 * lsn of the last item in the AIL.
52 */
53xfs_lsn_t
David Chinner5b00f142008-10-30 17:39:00 +110054xfs_trans_ail_tail(
55 struct xfs_ail *ailp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070056{
57 xfs_lsn_t lsn;
58 xfs_log_item_t *lip;
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
David Chinnerc7e8f262008-10-30 17:39:23 +110060 spin_lock(&ailp->xa_lock);
David Chinner5b00f142008-10-30 17:39:00 +110061 lip = xfs_ail_min(ailp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 if (lip == NULL) {
63 lsn = (xfs_lsn_t)0;
64 } else {
65 lsn = lip->li_lsn;
66 }
David Chinnerc7e8f262008-10-30 17:39:23 +110067 spin_unlock(&ailp->xa_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
69 return lsn;
70}
71
72/*
73 * xfs_trans_push_ail
74 *
David Chinner249a8c12008-02-05 12:13:32 +110075 * This routine is called to move the tail of the AIL forward. It does this by
76 * trying to flush items in the AIL whose lsns are below the given
77 * threshold_lsn.
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 *
David Chinner249a8c12008-02-05 12:13:32 +110079 * the push is run asynchronously in a separate thread, so we return the tail
80 * of the log right now instead of the tail after the push. This means we will
81 * either continue right away, or we will sleep waiting on the async thread to
Malcolm Parsons9da096f2009-03-29 09:55:42 +020082 * do its work.
David Chinner249a8c12008-02-05 12:13:32 +110083 *
84 * We do this unlocked - we only need to know whether there is anything in the
85 * AIL at the time we are called. We don't need to access the contents of
86 * any of the objects, so the lock is not needed.
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 */
David Chinner249a8c12008-02-05 12:13:32 +110088void
David Chinner783a2f62008-10-30 17:39:58 +110089xfs_trans_ail_push(
90 struct xfs_ail *ailp,
91 xfs_lsn_t threshold_lsn)
Linus Torvalds1da177e2005-04-16 15:20:36 -070092{
David Chinner783a2f62008-10-30 17:39:58 +110093 xfs_log_item_t *lip;
Linus Torvalds1da177e2005-04-16 15:20:36 -070094
David Chinner783a2f62008-10-30 17:39:58 +110095 lip = xfs_ail_min(ailp);
96 if (lip && !XFS_FORCED_SHUTDOWN(ailp->xa_mount)) {
97 if (XFS_LSN_CMP(threshold_lsn, ailp->xa_target) > 0)
98 xfsaild_wakeup(ailp, threshold_lsn);
David Chinner249a8c12008-02-05 12:13:32 +110099 }
100}
101
102/*
David Chinner27d8d5f2008-10-30 17:38:39 +1100103 * AIL traversal cursor initialisation.
104 *
105 * The cursor keeps track of where our current traversal is up
106 * to by tracking the next ƣtem in the list for us. However, for
107 * this to be safe, removing an object from the AIL needs to invalidate
108 * any cursor that points to it. hence the traversal cursor needs to
109 * be linked to the struct xfs_ail so that deletion can search all the
110 * active cursors for invalidation.
111 *
112 * We don't link the push cursor because it is embedded in the struct
113 * xfs_ail and hence easily findable.
114 */
David Chinner5b00f142008-10-30 17:39:00 +1100115STATIC void
David Chinner27d8d5f2008-10-30 17:38:39 +1100116xfs_trans_ail_cursor_init(
117 struct xfs_ail *ailp,
118 struct xfs_ail_cursor *cur)
119{
120 cur->item = NULL;
121 if (cur == &ailp->xa_cursors)
122 return;
123
124 cur->next = ailp->xa_cursors.next;
125 ailp->xa_cursors.next = cur;
126}
127
128/*
129 * Set the cursor to the next item, because when we look
130 * up the cursor the current item may have been freed.
131 */
132STATIC void
133xfs_trans_ail_cursor_set(
134 struct xfs_ail *ailp,
135 struct xfs_ail_cursor *cur,
136 struct xfs_log_item *lip)
137{
138 if (lip)
139 cur->item = xfs_ail_next(ailp, lip);
140}
141
142/*
143 * Get the next item in the traversal and advance the cursor.
144 * If the cursor was invalidated (inidicated by a lip of 1),
145 * restart the traversal.
146 */
David Chinner5b00f142008-10-30 17:39:00 +1100147struct xfs_log_item *
David Chinner27d8d5f2008-10-30 17:38:39 +1100148xfs_trans_ail_cursor_next(
149 struct xfs_ail *ailp,
150 struct xfs_ail_cursor *cur)
151{
152 struct xfs_log_item *lip = cur->item;
153
154 if ((__psint_t)lip & 1)
155 lip = xfs_ail_min(ailp);
156 xfs_trans_ail_cursor_set(ailp, cur, lip);
157 return lip;
158}
159
160/*
David Chinner27d8d5f2008-10-30 17:38:39 +1100161 * Now that the traversal is complete, we need to remove the cursor
162 * from the list of traversing cursors. Avoid removing the embedded
Malcolm Parsons9da096f2009-03-29 09:55:42 +0200163 * push cursor, but use the fact it is always present to make the
David Chinner27d8d5f2008-10-30 17:38:39 +1100164 * list deletion simple.
165 */
166void
167xfs_trans_ail_cursor_done(
168 struct xfs_ail *ailp,
169 struct xfs_ail_cursor *done)
170{
171 struct xfs_ail_cursor *prev = NULL;
172 struct xfs_ail_cursor *cur;
173
174 done->item = NULL;
175 if (done == &ailp->xa_cursors)
176 return;
177 prev = &ailp->xa_cursors;
178 for (cur = prev->next; cur; prev = cur, cur = prev->next) {
179 if (cur == done) {
180 prev->next = cur->next;
181 break;
182 }
183 }
184 ASSERT(cur);
185}
186
187/*
David Chinner5b00f142008-10-30 17:39:00 +1100188 * Invalidate any cursor that is pointing to this item. This is
189 * called when an item is removed from the AIL. Any cursor pointing
190 * to this object is now invalid and the traversal needs to be
191 * terminated so it doesn't reference a freed object. We set the
192 * cursor item to a value of 1 so we can distinguish between an
193 * invalidation and the end of the list when getting the next item
194 * from the cursor.
195 */
196STATIC void
197xfs_trans_ail_cursor_clear(
198 struct xfs_ail *ailp,
199 struct xfs_log_item *lip)
200{
201 struct xfs_ail_cursor *cur;
202
203 /* need to search all cursors */
204 for (cur = &ailp->xa_cursors; cur; cur = cur->next) {
205 if (cur->item == lip)
206 cur->item = (struct xfs_log_item *)
207 ((__psint_t)cur->item | 1);
208 }
209}
210
211/*
David Chinner249a8c12008-02-05 12:13:32 +1100212 * Return the item in the AIL with the current lsn.
213 * Return the current tree generation number for use
214 * in calls to xfs_trans_next_ail().
215 */
David Chinner5b00f142008-10-30 17:39:00 +1100216xfs_log_item_t *
217xfs_trans_ail_cursor_first(
David Chinner27d8d5f2008-10-30 17:38:39 +1100218 struct xfs_ail *ailp,
219 struct xfs_ail_cursor *cur,
220 xfs_lsn_t lsn)
David Chinner249a8c12008-02-05 12:13:32 +1100221{
David Chinner27d8d5f2008-10-30 17:38:39 +1100222 xfs_log_item_t *lip;
David Chinner249a8c12008-02-05 12:13:32 +1100223
David Chinner5b00f142008-10-30 17:39:00 +1100224 xfs_trans_ail_cursor_init(ailp, cur);
David Chinner27d8d5f2008-10-30 17:38:39 +1100225 lip = xfs_ail_min(ailp);
David Chinner249a8c12008-02-05 12:13:32 +1100226 if (lsn == 0)
David Chinner5b00f142008-10-30 17:39:00 +1100227 goto out;
David Chinner249a8c12008-02-05 12:13:32 +1100228
David Chinner27d8d5f2008-10-30 17:38:39 +1100229 list_for_each_entry(lip, &ailp->xa_ail, li_ail) {
David Chinner5b00f142008-10-30 17:39:00 +1100230 if (XFS_LSN_CMP(lip->li_lsn, lsn) >= 0)
David Chinner7ee49ac2008-10-30 18:26:51 +1100231 goto out;
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100232 }
David Chinner5b00f142008-10-30 17:39:00 +1100233 lip = NULL;
234out:
235 xfs_trans_ail_cursor_set(ailp, cur, lip);
236 return lip;
David Chinner249a8c12008-02-05 12:13:32 +1100237}
238
239/*
240 * Function that does the work of pushing on the AIL
241 */
242long
243xfsaild_push(
David Chinner82fa9012008-10-30 17:38:26 +1100244 struct xfs_ail *ailp,
David Chinner249a8c12008-02-05 12:13:32 +1100245 xfs_lsn_t *last_lsn)
246{
247 long tout = 1000; /* milliseconds */
248 xfs_lsn_t last_pushed_lsn = *last_lsn;
David Chinner82fa9012008-10-30 17:38:26 +1100249 xfs_lsn_t target = ailp->xa_target;
David Chinner249a8c12008-02-05 12:13:32 +1100250 xfs_lsn_t lsn;
251 xfs_log_item_t *lip;
David Chinner249a8c12008-02-05 12:13:32 +1100252 int flush_log, count, stuck;
David Chinner82fa9012008-10-30 17:38:26 +1100253 xfs_mount_t *mp = ailp->xa_mount;
David Chinner27d8d5f2008-10-30 17:38:39 +1100254 struct xfs_ail_cursor *cur = &ailp->xa_cursors;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
David Chinnerc7e8f262008-10-30 17:39:23 +1100256 spin_lock(&ailp->xa_lock);
David Chinner27d8d5f2008-10-30 17:38:39 +1100257 xfs_trans_ail_cursor_init(ailp, cur);
David Chinner5b00f142008-10-30 17:39:00 +1100258 lip = xfs_trans_ail_cursor_first(ailp, cur, *last_lsn);
David Chinner249a8c12008-02-05 12:13:32 +1100259 if (!lip || XFS_FORCED_SHUTDOWN(mp)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 /*
David Chinner249a8c12008-02-05 12:13:32 +1100261 * AIL is empty or our push has reached the end.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 */
David Chinner27d8d5f2008-10-30 17:38:39 +1100263 xfs_trans_ail_cursor_done(ailp, cur);
David Chinnerc7e8f262008-10-30 17:39:23 +1100264 spin_unlock(&ailp->xa_lock);
David Chinner249a8c12008-02-05 12:13:32 +1100265 last_pushed_lsn = 0;
David Chinner27d8d5f2008-10-30 17:38:39 +1100266 return tout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 }
268
269 XFS_STATS_INC(xs_push_ail);
270
271 /*
272 * While the item we are looking at is below the given threshold
David Chinner249a8c12008-02-05 12:13:32 +1100273 * try to flush it out. We'd like not to stop until we've at least
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 * tried to push on everything in the AIL with an LSN less than
David Chinner249a8c12008-02-05 12:13:32 +1100275 * the given threshold.
276 *
277 * However, we will stop after a certain number of pushes and wait
278 * for a reduced timeout to fire before pushing further. This
279 * prevents use from spinning when we can't do anything or there is
280 * lots of contention on the AIL lists.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 */
David Chinner249a8c12008-02-05 12:13:32 +1100282 tout = 10;
283 lsn = lip->li_lsn;
David Chinner27d8d5f2008-10-30 17:38:39 +1100284 flush_log = stuck = count = 0;
David Chinner249a8c12008-02-05 12:13:32 +1100285 while ((XFS_LSN_CMP(lip->li_lsn, target) < 0)) {
286 int lock_result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 /*
David Chinner249a8c12008-02-05 12:13:32 +1100288 * If we can lock the item without sleeping, unlock the AIL
289 * lock and flush the item. Then re-grab the AIL lock so we
290 * can look for the next item on the AIL. List changes are
291 * handled by the AIL lookup functions internally
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 *
David Chinner249a8c12008-02-05 12:13:32 +1100293 * If we can't lock the item, either its holder will flush it
294 * or it is already being flushed or it is being relogged. In
295 * any of these case it is being taken care of and we can just
296 * skip to the next item in the list.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 */
298 lock_result = IOP_TRYLOCK(lip);
David Chinnerc7e8f262008-10-30 17:39:23 +1100299 spin_unlock(&ailp->xa_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 switch (lock_result) {
David Chinner249a8c12008-02-05 12:13:32 +1100301 case XFS_ITEM_SUCCESS:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 XFS_STATS_INC(xs_push_ail_success);
303 IOP_PUSH(lip);
David Chinner249a8c12008-02-05 12:13:32 +1100304 last_pushed_lsn = lsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 break;
306
David Chinner249a8c12008-02-05 12:13:32 +1100307 case XFS_ITEM_PUSHBUF:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 XFS_STATS_INC(xs_push_ail_pushbuf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 IOP_PUSHBUF(lip);
David Chinner249a8c12008-02-05 12:13:32 +1100310 last_pushed_lsn = lsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 break;
312
David Chinner249a8c12008-02-05 12:13:32 +1100313 case XFS_ITEM_PINNED:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 XFS_STATS_INC(xs_push_ail_pinned);
David Chinner249a8c12008-02-05 12:13:32 +1100315 stuck++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 flush_log = 1;
317 break;
318
David Chinner249a8c12008-02-05 12:13:32 +1100319 case XFS_ITEM_LOCKED:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 XFS_STATS_INC(xs_push_ail_locked);
David Chinner249a8c12008-02-05 12:13:32 +1100321 last_pushed_lsn = lsn;
322 stuck++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 break;
324
David Chinner249a8c12008-02-05 12:13:32 +1100325 case XFS_ITEM_FLUSHING:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 XFS_STATS_INC(xs_push_ail_flushing);
David Chinner249a8c12008-02-05 12:13:32 +1100327 last_pushed_lsn = lsn;
328 stuck++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 break;
330
David Chinner249a8c12008-02-05 12:13:32 +1100331 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 ASSERT(0);
333 break;
334 }
335
David Chinnerc7e8f262008-10-30 17:39:23 +1100336 spin_lock(&ailp->xa_lock);
David Chinner249a8c12008-02-05 12:13:32 +1100337 /* should we bother continuing? */
338 if (XFS_FORCED_SHUTDOWN(mp))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 break;
David Chinner249a8c12008-02-05 12:13:32 +1100340 ASSERT(mp->m_log);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
David Chinner249a8c12008-02-05 12:13:32 +1100342 count++;
343
344 /*
345 * Are there too many items we can't do anything with?
346 * If we we are skipping too many items because we can't flush
347 * them or they are already being flushed, we back off and
348 * given them time to complete whatever operation is being
349 * done. i.e. remove pressure from the AIL while we can't make
350 * progress so traversals don't slow down further inserts and
351 * removals to/from the AIL.
352 *
353 * The value of 100 is an arbitrary magic number based on
354 * observation.
355 */
356 if (stuck > 100)
357 break;
358
David Chinner27d8d5f2008-10-30 17:38:39 +1100359 lip = xfs_trans_ail_cursor_next(ailp, cur);
David Chinner249a8c12008-02-05 12:13:32 +1100360 if (lip == NULL)
361 break;
David Chinner249a8c12008-02-05 12:13:32 +1100362 lsn = lip->li_lsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 }
David Chinner27d8d5f2008-10-30 17:38:39 +1100364 xfs_trans_ail_cursor_done(ailp, cur);
David Chinnerc7e8f262008-10-30 17:39:23 +1100365 spin_unlock(&ailp->xa_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366
367 if (flush_log) {
368 /*
369 * If something we need to push out was pinned, then
370 * push out the log so it will become unpinned and
371 * move forward in the AIL.
372 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 XFS_STATS_INC(xs_push_ail_flush);
374 xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 }
376
David Chinner92d9cd12008-03-06 13:45:10 +1100377 if (!count) {
378 /* We're past our target or empty, so idle */
379 tout = 1000;
380 } else if (XFS_LSN_CMP(lsn, target) >= 0) {
381 /*
382 * We reached the target so wait a bit longer for I/O to
383 * complete and remove pushed items from the AIL before we
384 * start the next scan from the start of the AIL.
385 */
David Chinner249a8c12008-02-05 12:13:32 +1100386 tout += 20;
387 last_pushed_lsn = 0;
David Chinner27d8d5f2008-10-30 17:38:39 +1100388 } else if ((stuck * 100) / count > 90) {
David Chinner249a8c12008-02-05 12:13:32 +1100389 /*
390 * Either there is a lot of contention on the AIL or we
391 * are stuck due to operations in progress. "Stuck" in this
392 * case is defined as >90% of the items we tried to push
393 * were stuck.
394 *
395 * Backoff a bit more to allow some I/O to complete before
396 * continuing from where we were.
397 */
398 tout += 10;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 }
David Chinner249a8c12008-02-05 12:13:32 +1100400 *last_lsn = last_pushed_lsn;
401 return tout;
402} /* xfsaild_push */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403
404
405/*
406 * This is to be called when an item is unlocked that may have
407 * been in the AIL. It will wake up the first member of the AIL
408 * wait list if this item's unlocking might allow it to progress.
409 * If the item is in the AIL, then we need to get the AIL lock
410 * while doing our checking so we don't race with someone going
411 * to sleep waiting for this event in xfs_trans_push_ail().
412 */
413void
414xfs_trans_unlocked_item(
David Chinner783a2f62008-10-30 17:39:58 +1100415 struct xfs_ail *ailp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 xfs_log_item_t *lip)
417{
418 xfs_log_item_t *min_lip;
419
420 /*
421 * If we're forcibly shutting down, we may have
422 * unlocked log items arbitrarily. The last thing
423 * we want to do is to move the tail of the log
424 * over some potentially valid data.
425 */
426 if (!(lip->li_flags & XFS_LI_IN_AIL) ||
David Chinner783a2f62008-10-30 17:39:58 +1100427 XFS_FORCED_SHUTDOWN(ailp->xa_mount)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 return;
429 }
430
431 /*
432 * This is the one case where we can call into xfs_ail_min()
433 * without holding the AIL lock because we only care about the
434 * case where we are at the tail of the AIL. If the object isn't
435 * at the tail, it doesn't matter what result we get back. This
436 * is slightly racy because since we were just unlocked, we could
437 * go to sleep between the call to xfs_ail_min and the call to
438 * xfs_log_move_tail, have someone else lock us, commit to us disk,
439 * move us out of the tail of the AIL, and then we wake up. However,
440 * the call to xfs_log_move_tail() doesn't do anything if there's
441 * not enough free space to wake people up so we're safe calling it.
442 */
David Chinner783a2f62008-10-30 17:39:58 +1100443 min_lip = xfs_ail_min(ailp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444
445 if (min_lip == lip)
David Chinner783a2f62008-10-30 17:39:58 +1100446 xfs_log_move_tail(ailp->xa_mount, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447} /* xfs_trans_unlocked_item */
448
449
450/*
451 * Update the position of the item in the AIL with the new
452 * lsn. If it is not yet in the AIL, add it. Otherwise, move
453 * it to its new position by removing it and re-adding it.
454 *
455 * Wakeup anyone with an lsn less than the item's lsn. If the item
456 * we move in the AIL is the minimum one, update the tail lsn in the
457 * log manager.
458 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 * This function must be called with the AIL lock held. The lock
Donald Douwsma287f3da2007-10-11 17:36:05 +1000460 * is dropped before returning.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 */
462void
David Chinner783a2f62008-10-30 17:39:58 +1100463xfs_trans_ail_update(
464 struct xfs_ail *ailp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 xfs_log_item_t *lip,
David Chinnerc7e8f262008-10-30 17:39:23 +1100466 xfs_lsn_t lsn) __releases(ailp->xa_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467{
David Chinnerc7e8f262008-10-30 17:39:23 +1100468 xfs_log_item_t *dlip = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 xfs_log_item_t *mlip; /* ptr to minimum lip */
470
David Chinnerc7e8f262008-10-30 17:39:23 +1100471 mlip = xfs_ail_min(ailp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472
473 if (lip->li_flags & XFS_LI_IN_AIL) {
David Chinnerc7e8f262008-10-30 17:39:23 +1100474 dlip = xfs_ail_delete(ailp, lip);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 ASSERT(dlip == lip);
David Chinnerc7e8f262008-10-30 17:39:23 +1100476 xfs_trans_ail_cursor_clear(ailp, dlip);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 } else {
478 lip->li_flags |= XFS_LI_IN_AIL;
479 }
480
481 lip->li_lsn = lsn;
David Chinnerc7e8f262008-10-30 17:39:23 +1100482 xfs_ail_insert(ailp, lip);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483
484 if (mlip == dlip) {
David Chinnerc7e8f262008-10-30 17:39:23 +1100485 mlip = xfs_ail_min(ailp);
486 spin_unlock(&ailp->xa_lock);
David Chinner783a2f62008-10-30 17:39:58 +1100487 xfs_log_move_tail(ailp->xa_mount, mlip->li_lsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 } else {
David Chinnerc7e8f262008-10-30 17:39:23 +1100489 spin_unlock(&ailp->xa_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 }
491
492
493} /* xfs_trans_update_ail */
494
495/*
496 * Delete the given item from the AIL. It must already be in
497 * the AIL.
498 *
499 * Wakeup anyone with an lsn less than item's lsn. If the item
500 * we delete in the AIL is the minimum one, update the tail lsn in the
501 * log manager.
502 *
503 * Clear the IN_AIL flag from the item, reset its lsn to 0, and
504 * bump the AIL's generation count to indicate that the tree
505 * has changed.
506 *
507 * This function must be called with the AIL lock held. The lock
Donald Douwsma287f3da2007-10-11 17:36:05 +1000508 * is dropped before returning.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 */
510void
David Chinner783a2f62008-10-30 17:39:58 +1100511xfs_trans_ail_delete(
512 struct xfs_ail *ailp,
David Chinnerc7e8f262008-10-30 17:39:23 +1100513 xfs_log_item_t *lip) __releases(ailp->xa_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 xfs_log_item_t *dlip;
516 xfs_log_item_t *mlip;
517
518 if (lip->li_flags & XFS_LI_IN_AIL) {
David Chinnerc7e8f262008-10-30 17:39:23 +1100519 mlip = xfs_ail_min(ailp);
520 dlip = xfs_ail_delete(ailp, lip);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 ASSERT(dlip == lip);
David Chinnerc7e8f262008-10-30 17:39:23 +1100522 xfs_trans_ail_cursor_clear(ailp, dlip);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523
524
525 lip->li_flags &= ~XFS_LI_IN_AIL;
526 lip->li_lsn = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527
528 if (mlip == dlip) {
David Chinnerc7e8f262008-10-30 17:39:23 +1100529 mlip = xfs_ail_min(ailp);
530 spin_unlock(&ailp->xa_lock);
David Chinner783a2f62008-10-30 17:39:58 +1100531 xfs_log_move_tail(ailp->xa_mount,
532 (mlip ? mlip->li_lsn : 0));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 } else {
David Chinnerc7e8f262008-10-30 17:39:23 +1100534 spin_unlock(&ailp->xa_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 }
536 }
537 else {
538 /*
539 * If the file system is not being shutdown, we are in
540 * serious trouble if we get to this stage.
541 */
David Chinner783a2f62008-10-30 17:39:58 +1100542 struct xfs_mount *mp = ailp->xa_mount;
543
David Chinnerc7e8f262008-10-30 17:39:23 +1100544 spin_unlock(&ailp->xa_lock);
545 if (!XFS_FORCED_SHUTDOWN(mp)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 xfs_cmn_err(XFS_PTAG_AILDELETE, CE_ALERT, mp,
Nathan Scott7d04a332006-06-09 14:58:38 +1000547 "%s: attempting to delete a log item that is not in the AIL",
Harvey Harrison34a622b2008-04-10 12:19:21 +1000548 __func__);
Nathan Scott7d04a332006-06-09 14:58:38 +1000549 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 }
551 }
552}
553
554
555
556/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 * The active item list (AIL) is a doubly linked list of log
558 * items sorted by ascending lsn. The base of the list is
559 * a forw/back pointer pair embedded in the xfs mount structure.
560 * The base is initialized with both pointers pointing to the
561 * base. This case always needs to be distinguished, because
562 * the base has no lsn to look at. We almost always insert
563 * at the end of the list, so on inserts we search from the
564 * end of the list to find where the new item belongs.
565 */
566
567/*
568 * Initialize the doubly linked list to point only to itself.
569 */
David Chinner249a8c12008-02-05 12:13:32 +1100570int
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571xfs_trans_ail_init(
572 xfs_mount_t *mp)
573{
David Chinner82fa9012008-10-30 17:38:26 +1100574 struct xfs_ail *ailp;
David Chinner27d8d5f2008-10-30 17:38:39 +1100575 int error;
David Chinner82fa9012008-10-30 17:38:26 +1100576
577 ailp = kmem_zalloc(sizeof(struct xfs_ail), KM_MAYFAIL);
578 if (!ailp)
579 return ENOMEM;
580
581 ailp->xa_mount = mp;
582 INIT_LIST_HEAD(&ailp->xa_ail);
David Chinnerc7e8f262008-10-30 17:39:23 +1100583 spin_lock_init(&ailp->xa_lock);
David Chinner27d8d5f2008-10-30 17:38:39 +1100584 error = xfsaild_start(ailp);
585 if (error)
586 goto out_free_ailp;
587 mp->m_ail = ailp;
588 return 0;
589
590out_free_ailp:
591 kmem_free(ailp);
592 return error;
David Chinner249a8c12008-02-05 12:13:32 +1100593}
594
595void
596xfs_trans_ail_destroy(
597 xfs_mount_t *mp)
598{
David Chinner82fa9012008-10-30 17:38:26 +1100599 struct xfs_ail *ailp = mp->m_ail;
600
601 xfsaild_stop(ailp);
602 kmem_free(ailp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603}
604
605/*
606 * Insert the given log item into the AIL.
607 * We almost always insert at the end of the list, so on inserts
608 * we search from the end of the list to find where the
609 * new item belongs.
610 */
611STATIC void
612xfs_ail_insert(
David Chinner82fa9012008-10-30 17:38:26 +1100613 struct xfs_ail *ailp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 xfs_log_item_t *lip)
615/* ARGSUSED */
616{
617 xfs_log_item_t *next_lip;
618
619 /*
620 * If the list is empty, just insert the item.
621 */
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100622 if (list_empty(&ailp->xa_ail)) {
623 list_add(&lip->li_ail, &ailp->xa_ail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 return;
625 }
626
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100627 list_for_each_entry_reverse(next_lip, &ailp->xa_ail, li_ail) {
628 if (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0)
629 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100632 ASSERT((&next_lip->li_ail == &ailp->xa_ail) ||
633 (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0));
634
635 list_add(&lip->li_ail, &next_lip->li_ail);
636
637 xfs_ail_check(ailp, lip);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 return;
639}
640
641/*
642 * Delete the given item from the AIL. Return a pointer to the item.
643 */
644/*ARGSUSED*/
645STATIC xfs_log_item_t *
646xfs_ail_delete(
David Chinner82fa9012008-10-30 17:38:26 +1100647 struct xfs_ail *ailp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 xfs_log_item_t *lip)
649/* ARGSUSED */
650{
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100651 xfs_ail_check(ailp, lip);
652
653 list_del(&lip->li_ail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 return lip;
656}
657
658/*
659 * Return a pointer to the first item in the AIL.
660 * If the AIL is empty, then return NULL.
661 */
662STATIC xfs_log_item_t *
663xfs_ail_min(
David Chinner82fa9012008-10-30 17:38:26 +1100664 struct xfs_ail *ailp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665/* ARGSUSED */
666{
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100667 if (list_empty(&ailp->xa_ail))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 return NULL;
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100669
670 return list_first_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671}
672
673/*
674 * Return a pointer to the item which follows
675 * the given item in the AIL. If the given item
676 * is the last item in the list, then return NULL.
677 */
678STATIC xfs_log_item_t *
679xfs_ail_next(
David Chinner82fa9012008-10-30 17:38:26 +1100680 struct xfs_ail *ailp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 xfs_log_item_t *lip)
682/* ARGSUSED */
683{
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100684 if (lip->li_ail.next == &ailp->xa_ail)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100687 return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688}
689
690#ifdef DEBUG
691/*
692 * Check that the list is sorted as it should be.
693 */
694STATIC void
695xfs_ail_check(
David Chinner82fa9012008-10-30 17:38:26 +1100696 struct xfs_ail *ailp,
David Chinnerde08dbc2008-02-05 12:13:38 +1100697 xfs_log_item_t *lip)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 xfs_log_item_t *prev_lip;
700
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100701 if (list_empty(&ailp->xa_ail))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703
704 /*
David Chinnerde08dbc2008-02-05 12:13:38 +1100705 * Check the next and previous entries are valid.
706 */
707 ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100708 prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail);
709 if (&prev_lip->li_ail != &ailp->xa_ail)
David Chinnerde08dbc2008-02-05 12:13:38 +1100710 ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100711
712 prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail);
713 if (&prev_lip->li_ail != &ailp->xa_ail)
David Chinnerde08dbc2008-02-05 12:13:38 +1100714 ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0);
David Chinnerde08dbc2008-02-05 12:13:38 +1100715
716
717#ifdef XFS_TRANS_DEBUG
718 /*
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100719 * Walk the list checking lsn ordering, and that every entry has the
720 * XFS_LI_IN_AIL flag set. This is really expensive, so only do it
721 * when specifically debugging the transaction subsystem.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 */
Josef 'Jeff' Sipek535f6b32008-03-27 17:58:27 +1100723 prev_lip = list_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
724 list_for_each_entry(lip, &ailp->xa_ail, li_ail) {
725 if (&prev_lip->li_ail != &ailp->xa_ail)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
728 prev_lip = lip;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 }
David Chinnerde08dbc2008-02-05 12:13:38 +1100730#endif /* XFS_TRANS_DEBUG */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731}
732#endif /* DEBUG */