Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
7b718769 | 2 | * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. |
c7e8f268 | 3 | * Copyright (c) 2008 Dave Chinner |
7b718769 | 4 | * All Rights Reserved. |
1da177e4 | 5 | * |
7b718769 NS |
6 | * This program is free software; you can redistribute it and/or |
7 | * modify it under the terms of the GNU General Public License as | |
1da177e4 LT |
8 | * published by the Free Software Foundation. |
9 | * | |
7b718769 NS |
10 | * This program is distributed in the hope that it would be useful, |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
1da177e4 | 14 | * |
7b718769 NS |
15 | * You should have received a copy of the GNU General Public License |
16 | * along with this program; if not, write the Free Software Foundation, | |
17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
1da177e4 | 18 | */ |
1da177e4 | 19 | #include "xfs.h" |
a844f451 | 20 | #include "xfs_fs.h" |
1da177e4 | 21 | #include "xfs_types.h" |
1da177e4 | 22 | #include "xfs_log.h" |
a844f451 | 23 | #include "xfs_inum.h" |
1da177e4 LT |
24 | #include "xfs_trans.h" |
25 | #include "xfs_sb.h" | |
da353b0d | 26 | #include "xfs_ag.h" |
1da177e4 LT |
27 | #include "xfs_mount.h" |
28 | #include "xfs_trans_priv.h" | |
29 | #include "xfs_error.h" | |
30 | ||
1da177e4 | 31 | #ifdef DEBUG |
cd4a3c50 DC |
32 | /* |
33 | * Check that the list is sorted as it should be. | |
34 | */ | |
35 | STATIC void | |
36 | xfs_ail_check( | |
37 | struct xfs_ail *ailp, | |
38 | xfs_log_item_t *lip) | |
39 | { | |
40 | xfs_log_item_t *prev_lip; | |
41 | ||
42 | if (list_empty(&ailp->xa_ail)) | |
43 | return; | |
44 | ||
45 | /* | |
46 | * Check the next and previous entries are valid. | |
47 | */ | |
48 | ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0); | |
49 | prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail); | |
50 | if (&prev_lip->li_ail != &ailp->xa_ail) | |
51 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0); | |
52 | ||
53 | prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail); | |
54 | if (&prev_lip->li_ail != &ailp->xa_ail) | |
55 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0); | |
56 | ||
57 | ||
58 | #ifdef XFS_TRANS_DEBUG | |
59 | /* | |
60 | * Walk the list checking lsn ordering, and that every entry has the | |
61 | * XFS_LI_IN_AIL flag set. This is really expensive, so only do it | |
62 | * when specifically debugging the transaction subsystem. | |
63 | */ | |
64 | prev_lip = list_entry(&ailp->xa_ail, xfs_log_item_t, li_ail); | |
65 | list_for_each_entry(lip, &ailp->xa_ail, li_ail) { | |
66 | if (&prev_lip->li_ail != &ailp->xa_ail) | |
67 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0); | |
68 | ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0); | |
69 | prev_lip = lip; | |
70 | } | |
71 | #endif /* XFS_TRANS_DEBUG */ | |
72 | } | |
73 | #else /* !DEBUG */ | |
de08dbc1 | 74 | #define xfs_ail_check(a,l) |
1da177e4 LT |
75 | #endif /* DEBUG */ |
76 | ||
cd4a3c50 DC |
77 | /* |
78 | * Return a pointer to the first item in the AIL. If the AIL is empty, then | |
79 | * return NULL. | |
80 | */ | |
81 | static xfs_log_item_t * | |
82 | xfs_ail_min( | |
83 | struct xfs_ail *ailp) | |
84 | { | |
85 | if (list_empty(&ailp->xa_ail)) | |
86 | return NULL; | |
87 | ||
88 | return list_first_entry(&ailp->xa_ail, xfs_log_item_t, li_ail); | |
89 | } | |
90 | ||
fd074841 DC |
91 | /* |
92 | * Return a pointer to the last item in the AIL. If the AIL is empty, then | |
93 | * return NULL. | |
94 | */ | |
95 | static xfs_log_item_t * | |
96 | xfs_ail_max( | |
97 | struct xfs_ail *ailp) | |
98 | { | |
99 | if (list_empty(&ailp->xa_ail)) | |
100 | return NULL; | |
101 | ||
102 | return list_entry(ailp->xa_ail.prev, xfs_log_item_t, li_ail); | |
103 | } | |
104 | ||
cd4a3c50 DC |
105 | /* |
106 | * Return a pointer to the item which follows the given item in the AIL. If | |
107 | * the given item is the last item in the list, then return NULL. | |
108 | */ | |
109 | static xfs_log_item_t * | |
110 | xfs_ail_next( | |
111 | struct xfs_ail *ailp, | |
112 | xfs_log_item_t *lip) | |
113 | { | |
114 | if (lip->li_ail.next == &ailp->xa_ail) | |
115 | return NULL; | |
116 | ||
117 | return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail); | |
118 | } | |
1da177e4 LT |
119 | |
120 | /* | |
cd4a3c50 DC |
121 | * This is called by the log manager code to determine the LSN of the tail of |
122 | * the log. This is exactly the LSN of the first item in the AIL. If the AIL | |
123 | * is empty, then this function returns 0. | |
1da177e4 | 124 | * |
cd4a3c50 DC |
125 | * We need the AIL lock in order to get a coherent read of the lsn of the last |
126 | * item in the AIL. | |
1da177e4 LT |
127 | */ |
128 | xfs_lsn_t | |
fd074841 | 129 | xfs_ail_min_lsn( |
5b00f14f | 130 | struct xfs_ail *ailp) |
1da177e4 | 131 | { |
cd4a3c50 | 132 | xfs_lsn_t lsn = 0; |
1da177e4 | 133 | xfs_log_item_t *lip; |
1da177e4 | 134 | |
c7e8f268 | 135 | spin_lock(&ailp->xa_lock); |
5b00f14f | 136 | lip = xfs_ail_min(ailp); |
cd4a3c50 | 137 | if (lip) |
1da177e4 | 138 | lsn = lip->li_lsn; |
c7e8f268 | 139 | spin_unlock(&ailp->xa_lock); |
1da177e4 LT |
140 | |
141 | return lsn; | |
142 | } | |
143 | ||
fd074841 DC |
144 | /* |
145 | * Return the maximum lsn held in the AIL, or zero if the AIL is empty. | |
146 | */ | |
147 | static xfs_lsn_t | |
148 | xfs_ail_max_lsn( | |
149 | struct xfs_ail *ailp) | |
150 | { | |
151 | xfs_lsn_t lsn = 0; | |
152 | xfs_log_item_t *lip; | |
153 | ||
154 | spin_lock(&ailp->xa_lock); | |
155 | lip = xfs_ail_max(ailp); | |
156 | if (lip) | |
157 | lsn = lip->li_lsn; | |
158 | spin_unlock(&ailp->xa_lock); | |
159 | ||
160 | return lsn; | |
161 | } | |
162 | ||
27d8d5fe | 163 | /* |
af3e4022 DC |
164 | * The cursor keeps track of where our current traversal is up to by tracking |
165 | * the next item in the list for us. However, for this to be safe, removing an | |
166 | * object from the AIL needs to invalidate any cursor that points to it. hence | |
167 | * the traversal cursor needs to be linked to the struct xfs_ail so that | |
168 | * deletion can search all the active cursors for invalidation. | |
27d8d5fe | 169 | */ |
5b00f14f | 170 | STATIC void |
27d8d5fe DC |
171 | xfs_trans_ail_cursor_init( |
172 | struct xfs_ail *ailp, | |
173 | struct xfs_ail_cursor *cur) | |
174 | { | |
175 | cur->item = NULL; | |
af3e4022 | 176 | list_add_tail(&cur->list, &ailp->xa_cursors); |
27d8d5fe DC |
177 | } |
178 | ||
27d8d5fe | 179 | /* |
af3e4022 DC |
180 | * Get the next item in the traversal and advance the cursor. If the cursor |
181 | * was invalidated (indicated by a lip of 1), restart the traversal. | |
27d8d5fe | 182 | */ |
5b00f14f | 183 | struct xfs_log_item * |
27d8d5fe DC |
184 | xfs_trans_ail_cursor_next( |
185 | struct xfs_ail *ailp, | |
186 | struct xfs_ail_cursor *cur) | |
187 | { | |
188 | struct xfs_log_item *lip = cur->item; | |
189 | ||
190 | if ((__psint_t)lip & 1) | |
191 | lip = xfs_ail_min(ailp); | |
16b59029 DC |
192 | if (lip) |
193 | cur->item = xfs_ail_next(ailp, lip); | |
27d8d5fe DC |
194 | return lip; |
195 | } | |
196 | ||
27d8d5fe | 197 | /* |
af3e4022 DC |
198 | * When the traversal is complete, we need to remove the cursor from the list |
199 | * of traversing cursors. | |
27d8d5fe DC |
200 | */ |
201 | void | |
202 | xfs_trans_ail_cursor_done( | |
203 | struct xfs_ail *ailp, | |
af3e4022 | 204 | struct xfs_ail_cursor *cur) |
27d8d5fe | 205 | { |
af3e4022 DC |
206 | cur->item = NULL; |
207 | list_del_init(&cur->list); | |
27d8d5fe DC |
208 | } |
209 | ||
5b00f14f | 210 | /* |
af3e4022 DC |
211 | * Invalidate any cursor that is pointing to this item. This is called when an |
212 | * item is removed from the AIL. Any cursor pointing to this object is now | |
213 | * invalid and the traversal needs to be terminated so it doesn't reference a | |
214 | * freed object. We set the low bit of the cursor item pointer so we can | |
215 | * distinguish between an invalidation and the end of the list when getting the | |
216 | * next item from the cursor. | |
5b00f14f DC |
217 | */ |
218 | STATIC void | |
219 | xfs_trans_ail_cursor_clear( | |
220 | struct xfs_ail *ailp, | |
221 | struct xfs_log_item *lip) | |
222 | { | |
223 | struct xfs_ail_cursor *cur; | |
224 | ||
af3e4022 | 225 | list_for_each_entry(cur, &ailp->xa_cursors, list) { |
5b00f14f DC |
226 | if (cur->item == lip) |
227 | cur->item = (struct xfs_log_item *) | |
228 | ((__psint_t)cur->item | 1); | |
229 | } | |
230 | } | |
231 | ||
249a8c11 | 232 | /* |
16b59029 DC |
233 | * Find the first item in the AIL with the given @lsn by searching in ascending |
234 | * LSN order and initialise the cursor to point to the next item for a | |
235 | * ascending traversal. Pass a @lsn of zero to initialise the cursor to the | |
236 | * first item in the AIL. Returns NULL if the list is empty. | |
249a8c11 | 237 | */ |
5b00f14f DC |
238 | xfs_log_item_t * |
239 | xfs_trans_ail_cursor_first( | |
27d8d5fe DC |
240 | struct xfs_ail *ailp, |
241 | struct xfs_ail_cursor *cur, | |
242 | xfs_lsn_t lsn) | |
249a8c11 | 243 | { |
27d8d5fe | 244 | xfs_log_item_t *lip; |
249a8c11 | 245 | |
5b00f14f | 246 | xfs_trans_ail_cursor_init(ailp, cur); |
16b59029 DC |
247 | |
248 | if (lsn == 0) { | |
249 | lip = xfs_ail_min(ailp); | |
5b00f14f | 250 | goto out; |
16b59029 | 251 | } |
249a8c11 | 252 | |
27d8d5fe | 253 | list_for_each_entry(lip, &ailp->xa_ail, li_ail) { |
5b00f14f | 254 | if (XFS_LSN_CMP(lip->li_lsn, lsn) >= 0) |
7ee49acf | 255 | goto out; |
535f6b37 | 256 | } |
16b59029 DC |
257 | return NULL; |
258 | ||
5b00f14f | 259 | out: |
16b59029 DC |
260 | if (lip) |
261 | cur->item = xfs_ail_next(ailp, lip); | |
5b00f14f | 262 | return lip; |
249a8c11 DC |
263 | } |
264 | ||
1d8c95a3 DC |
265 | static struct xfs_log_item * |
266 | __xfs_trans_ail_cursor_last( | |
267 | struct xfs_ail *ailp, | |
268 | xfs_lsn_t lsn) | |
269 | { | |
270 | xfs_log_item_t *lip; | |
271 | ||
272 | list_for_each_entry_reverse(lip, &ailp->xa_ail, li_ail) { | |
273 | if (XFS_LSN_CMP(lip->li_lsn, lsn) <= 0) | |
274 | return lip; | |
275 | } | |
276 | return NULL; | |
277 | } | |
278 | ||
279 | /* | |
16b59029 DC |
280 | * Find the last item in the AIL with the given @lsn by searching in descending |
281 | * LSN order and initialise the cursor to point to that item. If there is no | |
282 | * item with the value of @lsn, then it sets the cursor to the last item with an | |
283 | * LSN lower than @lsn. Returns NULL if the list is empty. | |
1d8c95a3 DC |
284 | */ |
285 | struct xfs_log_item * | |
286 | xfs_trans_ail_cursor_last( | |
287 | struct xfs_ail *ailp, | |
288 | struct xfs_ail_cursor *cur, | |
289 | xfs_lsn_t lsn) | |
290 | { | |
291 | xfs_trans_ail_cursor_init(ailp, cur); | |
292 | cur->item = __xfs_trans_ail_cursor_last(ailp, lsn); | |
293 | return cur->item; | |
294 | } | |
295 | ||
296 | /* | |
16b59029 | 297 | * Splice the log item list into the AIL at the given LSN. We splice to the |
1d8c95a3 DC |
298 | * tail of the given LSN to maintain insert order for push traversals. The |
299 | * cursor is optional, allowing repeated updates to the same LSN to avoid | |
e44f4112 | 300 | * repeated traversals. This should not be called with an empty list. |
cd4a3c50 DC |
301 | */ |
302 | static void | |
303 | xfs_ail_splice( | |
1d8c95a3 DC |
304 | struct xfs_ail *ailp, |
305 | struct xfs_ail_cursor *cur, | |
306 | struct list_head *list, | |
307 | xfs_lsn_t lsn) | |
cd4a3c50 | 308 | { |
e44f4112 AE |
309 | struct xfs_log_item *lip; |
310 | ||
311 | ASSERT(!list_empty(list)); | |
cd4a3c50 | 312 | |
1d8c95a3 | 313 | /* |
e44f4112 AE |
314 | * Use the cursor to determine the insertion point if one is |
315 | * provided. If not, or if the one we got is not valid, | |
316 | * find the place in the AIL where the items belong. | |
1d8c95a3 | 317 | */ |
e44f4112 AE |
318 | lip = cur ? cur->item : NULL; |
319 | if (!lip || (__psint_t) lip & 1) | |
1d8c95a3 DC |
320 | lip = __xfs_trans_ail_cursor_last(ailp, lsn); |
321 | ||
e44f4112 AE |
322 | /* |
323 | * If a cursor is provided, we know we're processing the AIL | |
324 | * in lsn order, and future items to be spliced in will | |
325 | * follow the last one being inserted now. Update the | |
326 | * cursor to point to that last item, now while we have a | |
327 | * reliable pointer to it. | |
328 | */ | |
329 | if (cur) | |
330 | cur->item = list_entry(list->prev, struct xfs_log_item, li_ail); | |
cd4a3c50 | 331 | |
1d8c95a3 | 332 | /* |
e44f4112 AE |
333 | * Finally perform the splice. Unless the AIL was empty, |
334 | * lip points to the item in the AIL _after_ which the new | |
335 | * items should go. If lip is null the AIL was empty, so | |
336 | * the new items go at the head of the AIL. | |
1d8c95a3 | 337 | */ |
e44f4112 AE |
338 | if (lip) |
339 | list_splice(list, &lip->li_ail); | |
340 | else | |
341 | list_splice(list, &ailp->xa_ail); | |
cd4a3c50 DC |
342 | } |
343 | ||
344 | /* | |
345 | * Delete the given item from the AIL. Return a pointer to the item. | |
346 | */ | |
347 | static void | |
348 | xfs_ail_delete( | |
349 | struct xfs_ail *ailp, | |
350 | xfs_log_item_t *lip) | |
351 | { | |
352 | xfs_ail_check(ailp, lip); | |
353 | list_del(&lip->li_ail); | |
354 | xfs_trans_ail_cursor_clear(ailp, lip); | |
355 | } | |
356 | ||
0030807c CH |
357 | static long |
358 | xfsaild_push( | |
359 | struct xfs_ail *ailp) | |
249a8c11 | 360 | { |
9e7004e7 | 361 | xfs_mount_t *mp = ailp->xa_mount; |
af3e4022 | 362 | struct xfs_ail_cursor cur; |
9e7004e7 DC |
363 | xfs_log_item_t *lip; |
364 | xfs_lsn_t lsn; | |
fe0da767 | 365 | xfs_lsn_t target; |
9e7004e7 DC |
366 | long tout = 10; |
367 | int flush_log = 0; | |
368 | int stuck = 0; | |
369 | int count = 0; | |
370 | int push_xfsbufd = 0; | |
1da177e4 | 371 | |
c7e8f268 | 372 | spin_lock(&ailp->xa_lock); |
fe0da767 | 373 | target = ailp->xa_target; |
af3e4022 | 374 | lip = xfs_trans_ail_cursor_first(ailp, &cur, ailp->xa_last_pushed_lsn); |
249a8c11 | 375 | if (!lip || XFS_FORCED_SHUTDOWN(mp)) { |
1da177e4 | 376 | /* |
249a8c11 | 377 | * AIL is empty or our push has reached the end. |
1da177e4 | 378 | */ |
af3e4022 | 379 | xfs_trans_ail_cursor_done(ailp, &cur); |
c7e8f268 | 380 | spin_unlock(&ailp->xa_lock); |
9e7004e7 | 381 | goto out_done; |
1da177e4 LT |
382 | } |
383 | ||
384 | XFS_STATS_INC(xs_push_ail); | |
385 | ||
386 | /* | |
387 | * While the item we are looking at is below the given threshold | |
249a8c11 | 388 | * try to flush it out. We'd like not to stop until we've at least |
1da177e4 | 389 | * tried to push on everything in the AIL with an LSN less than |
249a8c11 DC |
390 | * the given threshold. |
391 | * | |
392 | * However, we will stop after a certain number of pushes and wait | |
393 | * for a reduced timeout to fire before pushing further. This | |
394 | * prevents use from spinning when we can't do anything or there is | |
395 | * lots of contention on the AIL lists. | |
1da177e4 | 396 | */ |
249a8c11 | 397 | lsn = lip->li_lsn; |
50e86686 | 398 | while ((XFS_LSN_CMP(lip->li_lsn, target) <= 0)) { |
249a8c11 | 399 | int lock_result; |
1da177e4 | 400 | /* |
249a8c11 DC |
401 | * If we can lock the item without sleeping, unlock the AIL |
402 | * lock and flush the item. Then re-grab the AIL lock so we | |
403 | * can look for the next item on the AIL. List changes are | |
404 | * handled by the AIL lookup functions internally | |
1da177e4 | 405 | * |
249a8c11 DC |
406 | * If we can't lock the item, either its holder will flush it |
407 | * or it is already being flushed or it is being relogged. In | |
408 | * any of these case it is being taken care of and we can just | |
409 | * skip to the next item in the list. | |
1da177e4 LT |
410 | */ |
411 | lock_result = IOP_TRYLOCK(lip); | |
c7e8f268 | 412 | spin_unlock(&ailp->xa_lock); |
1da177e4 | 413 | switch (lock_result) { |
249a8c11 | 414 | case XFS_ITEM_SUCCESS: |
1da177e4 LT |
415 | XFS_STATS_INC(xs_push_ail_success); |
416 | IOP_PUSH(lip); | |
0bf6a5bd | 417 | ailp->xa_last_pushed_lsn = lsn; |
1da177e4 LT |
418 | break; |
419 | ||
249a8c11 | 420 | case XFS_ITEM_PUSHBUF: |
1da177e4 | 421 | XFS_STATS_INC(xs_push_ail_pushbuf); |
17b38471 CH |
422 | |
423 | if (!IOP_PUSHBUF(lip)) { | |
424 | stuck++; | |
425 | flush_log = 1; | |
426 | } else { | |
427 | ailp->xa_last_pushed_lsn = lsn; | |
428 | } | |
d808f617 | 429 | push_xfsbufd = 1; |
1da177e4 LT |
430 | break; |
431 | ||
249a8c11 | 432 | case XFS_ITEM_PINNED: |
1da177e4 | 433 | XFS_STATS_INC(xs_push_ail_pinned); |
249a8c11 | 434 | stuck++; |
1da177e4 LT |
435 | flush_log = 1; |
436 | break; | |
437 | ||
249a8c11 | 438 | case XFS_ITEM_LOCKED: |
1da177e4 | 439 | XFS_STATS_INC(xs_push_ail_locked); |
249a8c11 | 440 | stuck++; |
1da177e4 LT |
441 | break; |
442 | ||
249a8c11 | 443 | default: |
1da177e4 LT |
444 | ASSERT(0); |
445 | break; | |
446 | } | |
447 | ||
c7e8f268 | 448 | spin_lock(&ailp->xa_lock); |
249a8c11 DC |
449 | /* should we bother continuing? */ |
450 | if (XFS_FORCED_SHUTDOWN(mp)) | |
1da177e4 | 451 | break; |
249a8c11 DC |
452 | ASSERT(mp->m_log); |
453 | ||
454 | count++; | |
1da177e4 | 455 | |
249a8c11 DC |
456 | /* |
457 | * Are there too many items we can't do anything with? | |
458 | * If we we are skipping too many items because we can't flush | |
459 | * them or they are already being flushed, we back off and | |
460 | * given them time to complete whatever operation is being | |
461 | * done. i.e. remove pressure from the AIL while we can't make | |
462 | * progress so traversals don't slow down further inserts and | |
463 | * removals to/from the AIL. | |
464 | * | |
465 | * The value of 100 is an arbitrary magic number based on | |
466 | * observation. | |
467 | */ | |
468 | if (stuck > 100) | |
469 | break; | |
470 | ||
af3e4022 | 471 | lip = xfs_trans_ail_cursor_next(ailp, &cur); |
249a8c11 DC |
472 | if (lip == NULL) |
473 | break; | |
249a8c11 | 474 | lsn = lip->li_lsn; |
1da177e4 | 475 | } |
af3e4022 | 476 | xfs_trans_ail_cursor_done(ailp, &cur); |
c7e8f268 | 477 | spin_unlock(&ailp->xa_lock); |
1da177e4 LT |
478 | |
479 | if (flush_log) { | |
480 | /* | |
481 | * If something we need to push out was pinned, then | |
482 | * push out the log so it will become unpinned and | |
483 | * move forward in the AIL. | |
484 | */ | |
1da177e4 | 485 | XFS_STATS_INC(xs_push_ail_flush); |
a14a348b | 486 | xfs_log_force(mp, 0); |
1da177e4 LT |
487 | } |
488 | ||
d808f617 DC |
489 | if (push_xfsbufd) { |
490 | /* we've got delayed write buffers to flush */ | |
491 | wake_up_process(mp->m_ddev_targp->bt_task); | |
492 | } | |
493 | ||
0bf6a5bd | 494 | /* assume we have more work to do in a short while */ |
9e7004e7 | 495 | out_done: |
92d9cd10 DC |
496 | if (!count) { |
497 | /* We're past our target or empty, so idle */ | |
0bf6a5bd DC |
498 | ailp->xa_last_pushed_lsn = 0; |
499 | ||
0bf6a5bd | 500 | tout = 50; |
92d9cd10 DC |
501 | } else if (XFS_LSN_CMP(lsn, target) >= 0) { |
502 | /* | |
503 | * We reached the target so wait a bit longer for I/O to | |
504 | * complete and remove pushed items from the AIL before we | |
505 | * start the next scan from the start of the AIL. | |
506 | */ | |
453eac8a | 507 | tout = 50; |
0bf6a5bd | 508 | ailp->xa_last_pushed_lsn = 0; |
27d8d5fe | 509 | } else if ((stuck * 100) / count > 90) { |
249a8c11 DC |
510 | /* |
511 | * Either there is a lot of contention on the AIL or we | |
512 | * are stuck due to operations in progress. "Stuck" in this | |
513 | * case is defined as >90% of the items we tried to push | |
514 | * were stuck. | |
515 | * | |
516 | * Backoff a bit more to allow some I/O to complete before | |
517 | * continuing from where we were. | |
518 | */ | |
453eac8a | 519 | tout = 20; |
1da177e4 | 520 | } |
0bf6a5bd | 521 | |
0030807c CH |
522 | return tout; |
523 | } | |
524 | ||
525 | static int | |
526 | xfsaild( | |
527 | void *data) | |
528 | { | |
529 | struct xfs_ail *ailp = data; | |
530 | long tout = 0; /* milliseconds */ | |
531 | ||
532 | while (!kthread_should_stop()) { | |
533 | if (tout && tout <= 20) | |
534 | __set_current_state(TASK_KILLABLE); | |
535 | else | |
536 | __set_current_state(TASK_INTERRUPTIBLE); | |
537 | schedule_timeout(tout ? | |
538 | msecs_to_jiffies(tout) : MAX_SCHEDULE_TIMEOUT); | |
539 | ||
540 | try_to_freeze(); | |
541 | ||
542 | tout = xfsaild_push(ailp); | |
543 | } | |
544 | ||
545 | return 0; | |
453eac8a | 546 | } |
1da177e4 | 547 | |
0bf6a5bd DC |
548 | /* |
549 | * This routine is called to move the tail of the AIL forward. It does this by | |
550 | * trying to flush items in the AIL whose lsns are below the given | |
551 | * threshold_lsn. | |
552 | * | |
553 | * The push is run asynchronously in a workqueue, which means the caller needs | |
554 | * to handle waiting on the async flush for space to become available. | |
555 | * We don't want to interrupt any push that is in progress, hence we only queue | |
556 | * work if we set the pushing bit approriately. | |
557 | * | |
558 | * We do this unlocked - we only need to know whether there is anything in the | |
559 | * AIL at the time we are called. We don't need to access the contents of | |
560 | * any of the objects, so the lock is not needed. | |
561 | */ | |
562 | void | |
fd074841 | 563 | xfs_ail_push( |
0bf6a5bd DC |
564 | struct xfs_ail *ailp, |
565 | xfs_lsn_t threshold_lsn) | |
566 | { | |
567 | xfs_log_item_t *lip; | |
568 | ||
569 | lip = xfs_ail_min(ailp); | |
570 | if (!lip || XFS_FORCED_SHUTDOWN(ailp->xa_mount) || | |
571 | XFS_LSN_CMP(threshold_lsn, ailp->xa_target) <= 0) | |
572 | return; | |
573 | ||
574 | /* | |
575 | * Ensure that the new target is noticed in push code before it clears | |
576 | * the XFS_AIL_PUSHING_BIT. | |
577 | */ | |
578 | smp_wmb(); | |
fe0da767 | 579 | xfs_trans_ail_copy_lsn(ailp, &ailp->xa_target, &threshold_lsn); |
0030807c CH |
580 | smp_wmb(); |
581 | ||
582 | wake_up_process(ailp->xa_task); | |
0bf6a5bd | 583 | } |
1da177e4 | 584 | |
fd074841 DC |
585 | /* |
586 | * Push out all items in the AIL immediately | |
587 | */ | |
588 | void | |
589 | xfs_ail_push_all( | |
590 | struct xfs_ail *ailp) | |
591 | { | |
592 | xfs_lsn_t threshold_lsn = xfs_ail_max_lsn(ailp); | |
593 | ||
594 | if (threshold_lsn) | |
595 | xfs_ail_push(ailp, threshold_lsn); | |
596 | } | |
597 | ||
1da177e4 LT |
598 | /* |
599 | * This is to be called when an item is unlocked that may have | |
600 | * been in the AIL. It will wake up the first member of the AIL | |
601 | * wait list if this item's unlocking might allow it to progress. | |
602 | * If the item is in the AIL, then we need to get the AIL lock | |
603 | * while doing our checking so we don't race with someone going | |
604 | * to sleep waiting for this event in xfs_trans_push_ail(). | |
605 | */ | |
606 | void | |
607 | xfs_trans_unlocked_item( | |
783a2f65 | 608 | struct xfs_ail *ailp, |
1da177e4 LT |
609 | xfs_log_item_t *lip) |
610 | { | |
611 | xfs_log_item_t *min_lip; | |
612 | ||
613 | /* | |
614 | * If we're forcibly shutting down, we may have | |
615 | * unlocked log items arbitrarily. The last thing | |
616 | * we want to do is to move the tail of the log | |
617 | * over some potentially valid data. | |
618 | */ | |
619 | if (!(lip->li_flags & XFS_LI_IN_AIL) || | |
783a2f65 | 620 | XFS_FORCED_SHUTDOWN(ailp->xa_mount)) { |
1da177e4 LT |
621 | return; |
622 | } | |
623 | ||
624 | /* | |
625 | * This is the one case where we can call into xfs_ail_min() | |
626 | * without holding the AIL lock because we only care about the | |
627 | * case where we are at the tail of the AIL. If the object isn't | |
628 | * at the tail, it doesn't matter what result we get back. This | |
629 | * is slightly racy because since we were just unlocked, we could | |
630 | * go to sleep between the call to xfs_ail_min and the call to | |
631 | * xfs_log_move_tail, have someone else lock us, commit to us disk, | |
632 | * move us out of the tail of the AIL, and then we wake up. However, | |
633 | * the call to xfs_log_move_tail() doesn't do anything if there's | |
634 | * not enough free space to wake people up so we're safe calling it. | |
635 | */ | |
783a2f65 | 636 | min_lip = xfs_ail_min(ailp); |
1da177e4 LT |
637 | |
638 | if (min_lip == lip) | |
783a2f65 | 639 | xfs_log_move_tail(ailp->xa_mount, 1); |
1da177e4 LT |
640 | } /* xfs_trans_unlocked_item */ |
641 | ||
0e57f6a3 DC |
642 | /* |
643 | * xfs_trans_ail_update - bulk AIL insertion operation. | |
644 | * | |
645 | * @xfs_trans_ail_update takes an array of log items that all need to be | |
646 | * positioned at the same LSN in the AIL. If an item is not in the AIL, it will | |
647 | * be added. Otherwise, it will be repositioned by removing it and re-adding | |
648 | * it to the AIL. If we move the first item in the AIL, update the log tail to | |
649 | * match the new minimum LSN in the AIL. | |
650 | * | |
651 | * This function takes the AIL lock once to execute the update operations on | |
652 | * all the items in the array, and as such should not be called with the AIL | |
653 | * lock held. As a result, once we have the AIL lock, we need to check each log | |
654 | * item LSN to confirm it needs to be moved forward in the AIL. | |
655 | * | |
656 | * To optimise the insert operation, we delete all the items from the AIL in | |
657 | * the first pass, moving them into a temporary list, then splice the temporary | |
658 | * list into the correct position in the AIL. This avoids needing to do an | |
659 | * insert operation on every item. | |
660 | * | |
661 | * This function must be called with the AIL lock held. The lock is dropped | |
662 | * before returning. | |
663 | */ | |
664 | void | |
665 | xfs_trans_ail_update_bulk( | |
666 | struct xfs_ail *ailp, | |
1d8c95a3 | 667 | struct xfs_ail_cursor *cur, |
0e57f6a3 DC |
668 | struct xfs_log_item **log_items, |
669 | int nr_items, | |
670 | xfs_lsn_t lsn) __releases(ailp->xa_lock) | |
671 | { | |
672 | xfs_log_item_t *mlip; | |
673 | xfs_lsn_t tail_lsn; | |
674 | int mlip_changed = 0; | |
675 | int i; | |
676 | LIST_HEAD(tmp); | |
677 | ||
e44f4112 | 678 | ASSERT(nr_items > 0); /* Not required, but true. */ |
0e57f6a3 DC |
679 | mlip = xfs_ail_min(ailp); |
680 | ||
681 | for (i = 0; i < nr_items; i++) { | |
682 | struct xfs_log_item *lip = log_items[i]; | |
683 | if (lip->li_flags & XFS_LI_IN_AIL) { | |
684 | /* check if we really need to move the item */ | |
685 | if (XFS_LSN_CMP(lsn, lip->li_lsn) <= 0) | |
686 | continue; | |
687 | ||
688 | xfs_ail_delete(ailp, lip); | |
689 | if (mlip == lip) | |
690 | mlip_changed = 1; | |
691 | } else { | |
692 | lip->li_flags |= XFS_LI_IN_AIL; | |
693 | } | |
694 | lip->li_lsn = lsn; | |
695 | list_add(&lip->li_ail, &tmp); | |
696 | } | |
697 | ||
e44f4112 AE |
698 | if (!list_empty(&tmp)) |
699 | xfs_ail_splice(ailp, cur, &tmp, lsn); | |
0e57f6a3 DC |
700 | |
701 | if (!mlip_changed) { | |
702 | spin_unlock(&ailp->xa_lock); | |
703 | return; | |
704 | } | |
705 | ||
706 | /* | |
707 | * It is not safe to access mlip after the AIL lock is dropped, so we | |
708 | * must get a copy of li_lsn before we do so. This is especially | |
709 | * important on 32-bit platforms where accessing and updating 64-bit | |
710 | * values like li_lsn is not atomic. | |
711 | */ | |
712 | mlip = xfs_ail_min(ailp); | |
713 | tail_lsn = mlip->li_lsn; | |
714 | spin_unlock(&ailp->xa_lock); | |
715 | xfs_log_move_tail(ailp->xa_mount, tail_lsn); | |
716 | } | |
717 | ||
30136832 DC |
718 | /* |
719 | * xfs_trans_ail_delete_bulk - remove multiple log items from the AIL | |
720 | * | |
721 | * @xfs_trans_ail_delete_bulk takes an array of log items that all need to | |
722 | * removed from the AIL. The caller is already holding the AIL lock, and done | |
723 | * all the checks necessary to ensure the items passed in via @log_items are | |
724 | * ready for deletion. This includes checking that the items are in the AIL. | |
725 | * | |
726 | * For each log item to be removed, unlink it from the AIL, clear the IN_AIL | |
727 | * flag from the item and reset the item's lsn to 0. If we remove the first | |
728 | * item in the AIL, update the log tail to match the new minimum LSN in the | |
729 | * AIL. | |
730 | * | |
731 | * This function will not drop the AIL lock until all items are removed from | |
732 | * the AIL to minimise the amount of lock traffic on the AIL. This does not | |
733 | * greatly increase the AIL hold time, but does significantly reduce the amount | |
734 | * of traffic on the lock, especially during IO completion. | |
735 | * | |
736 | * This function must be called with the AIL lock held. The lock is dropped | |
737 | * before returning. | |
738 | */ | |
739 | void | |
740 | xfs_trans_ail_delete_bulk( | |
741 | struct xfs_ail *ailp, | |
742 | struct xfs_log_item **log_items, | |
743 | int nr_items) __releases(ailp->xa_lock) | |
744 | { | |
745 | xfs_log_item_t *mlip; | |
746 | xfs_lsn_t tail_lsn; | |
747 | int mlip_changed = 0; | |
748 | int i; | |
749 | ||
750 | mlip = xfs_ail_min(ailp); | |
751 | ||
752 | for (i = 0; i < nr_items; i++) { | |
753 | struct xfs_log_item *lip = log_items[i]; | |
754 | if (!(lip->li_flags & XFS_LI_IN_AIL)) { | |
755 | struct xfs_mount *mp = ailp->xa_mount; | |
756 | ||
757 | spin_unlock(&ailp->xa_lock); | |
758 | if (!XFS_FORCED_SHUTDOWN(mp)) { | |
6a19d939 | 759 | xfs_alert_tag(mp, XFS_PTAG_AILDELETE, |
30136832 DC |
760 | "%s: attempting to delete a log item that is not in the AIL", |
761 | __func__); | |
762 | xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); | |
763 | } | |
764 | return; | |
765 | } | |
766 | ||
767 | xfs_ail_delete(ailp, lip); | |
768 | lip->li_flags &= ~XFS_LI_IN_AIL; | |
769 | lip->li_lsn = 0; | |
770 | if (mlip == lip) | |
771 | mlip_changed = 1; | |
772 | } | |
773 | ||
774 | if (!mlip_changed) { | |
775 | spin_unlock(&ailp->xa_lock); | |
776 | return; | |
777 | } | |
778 | ||
779 | /* | |
780 | * It is not safe to access mlip after the AIL lock is dropped, so we | |
781 | * must get a copy of li_lsn before we do so. This is especially | |
782 | * important on 32-bit platforms where accessing and updating 64-bit | |
783 | * values like li_lsn is not atomic. It is possible we've emptied the | |
784 | * AIL here, so if that is the case, pass an LSN of 0 to the tail move. | |
785 | */ | |
786 | mlip = xfs_ail_min(ailp); | |
787 | tail_lsn = mlip ? mlip->li_lsn : 0; | |
788 | spin_unlock(&ailp->xa_lock); | |
789 | xfs_log_move_tail(ailp->xa_mount, tail_lsn); | |
790 | } | |
1da177e4 | 791 | |
1da177e4 LT |
792 | /* |
793 | * The active item list (AIL) is a doubly linked list of log | |
794 | * items sorted by ascending lsn. The base of the list is | |
795 | * a forw/back pointer pair embedded in the xfs mount structure. | |
796 | * The base is initialized with both pointers pointing to the | |
797 | * base. This case always needs to be distinguished, because | |
798 | * the base has no lsn to look at. We almost always insert | |
799 | * at the end of the list, so on inserts we search from the | |
800 | * end of the list to find where the new item belongs. | |
801 | */ | |
802 | ||
803 | /* | |
804 | * Initialize the doubly linked list to point only to itself. | |
805 | */ | |
249a8c11 | 806 | int |
1da177e4 LT |
807 | xfs_trans_ail_init( |
808 | xfs_mount_t *mp) | |
809 | { | |
82fa9012 DC |
810 | struct xfs_ail *ailp; |
811 | ||
812 | ailp = kmem_zalloc(sizeof(struct xfs_ail), KM_MAYFAIL); | |
813 | if (!ailp) | |
814 | return ENOMEM; | |
815 | ||
816 | ailp->xa_mount = mp; | |
817 | INIT_LIST_HEAD(&ailp->xa_ail); | |
af3e4022 | 818 | INIT_LIST_HEAD(&ailp->xa_cursors); |
c7e8f268 | 819 | spin_lock_init(&ailp->xa_lock); |
0030807c CH |
820 | |
821 | ailp->xa_task = kthread_run(xfsaild, ailp, "xfsaild/%s", | |
822 | ailp->xa_mount->m_fsname); | |
823 | if (IS_ERR(ailp->xa_task)) | |
824 | goto out_free_ailp; | |
825 | ||
27d8d5fe DC |
826 | mp->m_ail = ailp; |
827 | return 0; | |
0030807c CH |
828 | |
829 | out_free_ailp: | |
830 | kmem_free(ailp); | |
831 | return ENOMEM; | |
249a8c11 DC |
832 | } |
833 | ||
834 | void | |
835 | xfs_trans_ail_destroy( | |
836 | xfs_mount_t *mp) | |
837 | { | |
82fa9012 DC |
838 | struct xfs_ail *ailp = mp->m_ail; |
839 | ||
0030807c | 840 | kthread_stop(ailp->xa_task); |
82fa9012 | 841 | kmem_free(ailp); |
1da177e4 | 842 | } |