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71e330b5 DC |
1 | /* |
2 | * Copyright (c) 2010 Red Hat, Inc. All Rights Reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it would be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * along with this program; if not, write the Free Software Foundation, | |
15 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
16 | */ | |
17 | ||
18 | #include "xfs.h" | |
19 | #include "xfs_fs.h" | |
20 | #include "xfs_types.h" | |
21 | #include "xfs_bit.h" | |
22 | #include "xfs_log.h" | |
23 | #include "xfs_inum.h" | |
24 | #include "xfs_trans.h" | |
25 | #include "xfs_trans_priv.h" | |
26 | #include "xfs_log_priv.h" | |
27 | #include "xfs_sb.h" | |
28 | #include "xfs_ag.h" | |
71e330b5 DC |
29 | #include "xfs_mount.h" |
30 | #include "xfs_error.h" | |
31 | #include "xfs_alloc.h" | |
e84661aa | 32 | #include "xfs_discard.h" |
71e330b5 DC |
33 | |
34 | /* | |
35 | * Perform initial CIL structure initialisation. If the CIL is not | |
36 | * enabled in this filesystem, ensure the log->l_cilp is null so | |
37 | * we can check this conditional to determine if we are doing delayed | |
38 | * logging or not. | |
39 | */ | |
40 | int | |
41 | xlog_cil_init( | |
42 | struct log *log) | |
43 | { | |
44 | struct xfs_cil *cil; | |
45 | struct xfs_cil_ctx *ctx; | |
46 | ||
47 | log->l_cilp = NULL; | |
48 | if (!(log->l_mp->m_flags & XFS_MOUNT_DELAYLOG)) | |
49 | return 0; | |
50 | ||
51 | cil = kmem_zalloc(sizeof(*cil), KM_SLEEP|KM_MAYFAIL); | |
52 | if (!cil) | |
53 | return ENOMEM; | |
54 | ||
55 | ctx = kmem_zalloc(sizeof(*ctx), KM_SLEEP|KM_MAYFAIL); | |
56 | if (!ctx) { | |
57 | kmem_free(cil); | |
58 | return ENOMEM; | |
59 | } | |
60 | ||
61 | INIT_LIST_HEAD(&cil->xc_cil); | |
62 | INIT_LIST_HEAD(&cil->xc_committing); | |
63 | spin_lock_init(&cil->xc_cil_lock); | |
64 | init_rwsem(&cil->xc_ctx_lock); | |
eb40a875 | 65 | init_waitqueue_head(&cil->xc_commit_wait); |
71e330b5 DC |
66 | |
67 | INIT_LIST_HEAD(&ctx->committing); | |
68 | INIT_LIST_HEAD(&ctx->busy_extents); | |
69 | ctx->sequence = 1; | |
70 | ctx->cil = cil; | |
71 | cil->xc_ctx = ctx; | |
a44f13ed | 72 | cil->xc_current_sequence = ctx->sequence; |
71e330b5 DC |
73 | |
74 | cil->xc_log = log; | |
75 | log->l_cilp = cil; | |
76 | return 0; | |
77 | } | |
78 | ||
79 | void | |
80 | xlog_cil_destroy( | |
81 | struct log *log) | |
82 | { | |
83 | if (!log->l_cilp) | |
84 | return; | |
85 | ||
86 | if (log->l_cilp->xc_ctx) { | |
87 | if (log->l_cilp->xc_ctx->ticket) | |
88 | xfs_log_ticket_put(log->l_cilp->xc_ctx->ticket); | |
89 | kmem_free(log->l_cilp->xc_ctx); | |
90 | } | |
91 | ||
92 | ASSERT(list_empty(&log->l_cilp->xc_cil)); | |
93 | kmem_free(log->l_cilp); | |
94 | } | |
95 | ||
96 | /* | |
97 | * Allocate a new ticket. Failing to get a new ticket makes it really hard to | |
98 | * recover, so we don't allow failure here. Also, we allocate in a context that | |
99 | * we don't want to be issuing transactions from, so we need to tell the | |
100 | * allocation code this as well. | |
101 | * | |
102 | * We don't reserve any space for the ticket - we are going to steal whatever | |
103 | * space we require from transactions as they commit. To ensure we reserve all | |
104 | * the space required, we need to set the current reservation of the ticket to | |
105 | * zero so that we know to steal the initial transaction overhead from the | |
106 | * first transaction commit. | |
107 | */ | |
108 | static struct xlog_ticket * | |
109 | xlog_cil_ticket_alloc( | |
110 | struct log *log) | |
111 | { | |
112 | struct xlog_ticket *tic; | |
113 | ||
114 | tic = xlog_ticket_alloc(log, 0, 1, XFS_TRANSACTION, 0, | |
115 | KM_SLEEP|KM_NOFS); | |
116 | tic->t_trans_type = XFS_TRANS_CHECKPOINT; | |
117 | ||
118 | /* | |
119 | * set the current reservation to zero so we know to steal the basic | |
120 | * transaction overhead reservation from the first transaction commit. | |
121 | */ | |
122 | tic->t_curr_res = 0; | |
123 | return tic; | |
124 | } | |
125 | ||
126 | /* | |
127 | * After the first stage of log recovery is done, we know where the head and | |
128 | * tail of the log are. We need this log initialisation done before we can | |
129 | * initialise the first CIL checkpoint context. | |
130 | * | |
131 | * Here we allocate a log ticket to track space usage during a CIL push. This | |
132 | * ticket is passed to xlog_write() directly so that we don't slowly leak log | |
133 | * space by failing to account for space used by log headers and additional | |
134 | * region headers for split regions. | |
135 | */ | |
136 | void | |
137 | xlog_cil_init_post_recovery( | |
138 | struct log *log) | |
139 | { | |
140 | if (!log->l_cilp) | |
141 | return; | |
142 | ||
143 | log->l_cilp->xc_ctx->ticket = xlog_cil_ticket_alloc(log); | |
144 | log->l_cilp->xc_ctx->sequence = 1; | |
145 | log->l_cilp->xc_ctx->commit_lsn = xlog_assign_lsn(log->l_curr_cycle, | |
146 | log->l_curr_block); | |
147 | } | |
148 | ||
71e330b5 DC |
149 | /* |
150 | * Format log item into a flat buffers | |
151 | * | |
152 | * For delayed logging, we need to hold a formatted buffer containing all the | |
153 | * changes on the log item. This enables us to relog the item in memory and | |
154 | * write it out asynchronously without needing to relock the object that was | |
155 | * modified at the time it gets written into the iclog. | |
156 | * | |
157 | * This function builds a vector for the changes in each log item in the | |
158 | * transaction. It then works out the length of the buffer needed for each log | |
159 | * item, allocates them and formats the vector for the item into the buffer. | |
160 | * The buffer is then attached to the log item are then inserted into the | |
161 | * Committed Item List for tracking until the next checkpoint is written out. | |
162 | * | |
163 | * We don't set up region headers during this process; we simply copy the | |
164 | * regions into the flat buffer. We can do this because we still have to do a | |
165 | * formatting step to write the regions into the iclog buffer. Writing the | |
166 | * ophdrs during the iclog write means that we can support splitting large | |
167 | * regions across iclog boundares without needing a change in the format of the | |
168 | * item/region encapsulation. | |
169 | * | |
170 | * Hence what we need to do now is change the rewrite the vector array to point | |
171 | * to the copied region inside the buffer we just allocated. This allows us to | |
172 | * format the regions into the iclog as though they are being formatted | |
173 | * directly out of the objects themselves. | |
174 | */ | |
175 | static void | |
176 | xlog_cil_format_items( | |
177 | struct log *log, | |
3b93c7aa | 178 | struct xfs_log_vec *log_vector) |
71e330b5 DC |
179 | { |
180 | struct xfs_log_vec *lv; | |
181 | ||
71e330b5 DC |
182 | ASSERT(log_vector); |
183 | for (lv = log_vector; lv; lv = lv->lv_next) { | |
184 | void *ptr; | |
185 | int index; | |
186 | int len = 0; | |
187 | ||
188 | /* build the vector array and calculate it's length */ | |
189 | IOP_FORMAT(lv->lv_item, lv->lv_iovecp); | |
190 | for (index = 0; index < lv->lv_niovecs; index++) | |
191 | len += lv->lv_iovecp[index].i_len; | |
192 | ||
193 | lv->lv_buf_len = len; | |
d1583a38 | 194 | lv->lv_buf = kmem_alloc(lv->lv_buf_len, KM_SLEEP|KM_NOFS); |
71e330b5 DC |
195 | ptr = lv->lv_buf; |
196 | ||
197 | for (index = 0; index < lv->lv_niovecs; index++) { | |
198 | struct xfs_log_iovec *vec = &lv->lv_iovecp[index]; | |
199 | ||
200 | memcpy(ptr, vec->i_addr, vec->i_len); | |
201 | vec->i_addr = ptr; | |
202 | ptr += vec->i_len; | |
203 | } | |
204 | ASSERT(ptr == lv->lv_buf + lv->lv_buf_len); | |
3b93c7aa DC |
205 | } |
206 | } | |
71e330b5 | 207 | |
d1583a38 DC |
208 | /* |
209 | * Prepare the log item for insertion into the CIL. Calculate the difference in | |
210 | * log space and vectors it will consume, and if it is a new item pin it as | |
211 | * well. | |
212 | */ | |
213 | STATIC void | |
214 | xfs_cil_prepare_item( | |
215 | struct log *log, | |
216 | struct xfs_log_vec *lv, | |
217 | int *len, | |
218 | int *diff_iovecs) | |
219 | { | |
220 | struct xfs_log_vec *old = lv->lv_item->li_lv; | |
221 | ||
222 | if (old) { | |
223 | /* existing lv on log item, space used is a delta */ | |
224 | ASSERT(!list_empty(&lv->lv_item->li_cil)); | |
225 | ASSERT(old->lv_buf && old->lv_buf_len && old->lv_niovecs); | |
226 | ||
227 | *len += lv->lv_buf_len - old->lv_buf_len; | |
228 | *diff_iovecs += lv->lv_niovecs - old->lv_niovecs; | |
229 | kmem_free(old->lv_buf); | |
230 | kmem_free(old); | |
231 | } else { | |
232 | /* new lv, must pin the log item */ | |
233 | ASSERT(!lv->lv_item->li_lv); | |
234 | ASSERT(list_empty(&lv->lv_item->li_cil)); | |
235 | ||
236 | *len += lv->lv_buf_len; | |
237 | *diff_iovecs += lv->lv_niovecs; | |
238 | IOP_PIN(lv->lv_item); | |
239 | ||
240 | } | |
241 | ||
242 | /* attach new log vector to log item */ | |
243 | lv->lv_item->li_lv = lv; | |
244 | ||
245 | /* | |
246 | * If this is the first time the item is being committed to the | |
247 | * CIL, store the sequence number on the log item so we can | |
248 | * tell in future commits whether this is the first checkpoint | |
249 | * the item is being committed into. | |
250 | */ | |
251 | if (!lv->lv_item->li_seq) | |
252 | lv->lv_item->li_seq = log->l_cilp->xc_ctx->sequence; | |
253 | } | |
254 | ||
255 | /* | |
256 | * Insert the log items into the CIL and calculate the difference in space | |
257 | * consumed by the item. Add the space to the checkpoint ticket and calculate | |
258 | * if the change requires additional log metadata. If it does, take that space | |
42b2aa86 | 259 | * as well. Remove the amount of space we added to the checkpoint ticket from |
d1583a38 DC |
260 | * the current transaction ticket so that the accounting works out correctly. |
261 | */ | |
3b93c7aa DC |
262 | static void |
263 | xlog_cil_insert_items( | |
264 | struct log *log, | |
265 | struct xfs_log_vec *log_vector, | |
d1583a38 | 266 | struct xlog_ticket *ticket) |
3b93c7aa | 267 | { |
d1583a38 DC |
268 | struct xfs_cil *cil = log->l_cilp; |
269 | struct xfs_cil_ctx *ctx = cil->xc_ctx; | |
270 | struct xfs_log_vec *lv; | |
271 | int len = 0; | |
272 | int diff_iovecs = 0; | |
273 | int iclog_space; | |
3b93c7aa DC |
274 | |
275 | ASSERT(log_vector); | |
d1583a38 DC |
276 | |
277 | /* | |
278 | * Do all the accounting aggregation and switching of log vectors | |
279 | * around in a separate loop to the insertion of items into the CIL. | |
280 | * Then we can do a separate loop to update the CIL within a single | |
281 | * lock/unlock pair. This reduces the number of round trips on the CIL | |
282 | * lock from O(nr_logvectors) to O(1) and greatly reduces the overall | |
283 | * hold time for the transaction commit. | |
284 | * | |
285 | * If this is the first time the item is being placed into the CIL in | |
286 | * this context, pin it so it can't be written to disk until the CIL is | |
287 | * flushed to the iclog and the iclog written to disk. | |
288 | * | |
289 | * We can do this safely because the context can't checkpoint until we | |
290 | * are done so it doesn't matter exactly how we update the CIL. | |
291 | */ | |
292 | for (lv = log_vector; lv; lv = lv->lv_next) | |
293 | xfs_cil_prepare_item(log, lv, &len, &diff_iovecs); | |
294 | ||
295 | /* account for space used by new iovec headers */ | |
296 | len += diff_iovecs * sizeof(xlog_op_header_t); | |
297 | ||
298 | spin_lock(&cil->xc_cil_lock); | |
299 | ||
300 | /* move the items to the tail of the CIL */ | |
3b93c7aa | 301 | for (lv = log_vector; lv; lv = lv->lv_next) |
d1583a38 DC |
302 | list_move_tail(&lv->lv_item->li_cil, &cil->xc_cil); |
303 | ||
304 | ctx->nvecs += diff_iovecs; | |
305 | ||
306 | /* | |
307 | * Now transfer enough transaction reservation to the context ticket | |
308 | * for the checkpoint. The context ticket is special - the unit | |
309 | * reservation has to grow as well as the current reservation as we | |
310 | * steal from tickets so we can correctly determine the space used | |
311 | * during the transaction commit. | |
312 | */ | |
313 | if (ctx->ticket->t_curr_res == 0) { | |
314 | /* first commit in checkpoint, steal the header reservation */ | |
315 | ASSERT(ticket->t_curr_res >= ctx->ticket->t_unit_res + len); | |
316 | ctx->ticket->t_curr_res = ctx->ticket->t_unit_res; | |
317 | ticket->t_curr_res -= ctx->ticket->t_unit_res; | |
318 | } | |
319 | ||
320 | /* do we need space for more log record headers? */ | |
321 | iclog_space = log->l_iclog_size - log->l_iclog_hsize; | |
322 | if (len > 0 && (ctx->space_used / iclog_space != | |
323 | (ctx->space_used + len) / iclog_space)) { | |
324 | int hdrs; | |
325 | ||
326 | hdrs = (len + iclog_space - 1) / iclog_space; | |
327 | /* need to take into account split region headers, too */ | |
328 | hdrs *= log->l_iclog_hsize + sizeof(struct xlog_op_header); | |
329 | ctx->ticket->t_unit_res += hdrs; | |
330 | ctx->ticket->t_curr_res += hdrs; | |
331 | ticket->t_curr_res -= hdrs; | |
332 | ASSERT(ticket->t_curr_res >= len); | |
333 | } | |
334 | ticket->t_curr_res -= len; | |
335 | ctx->space_used += len; | |
336 | ||
337 | spin_unlock(&cil->xc_cil_lock); | |
71e330b5 DC |
338 | } |
339 | ||
340 | static void | |
341 | xlog_cil_free_logvec( | |
342 | struct xfs_log_vec *log_vector) | |
343 | { | |
344 | struct xfs_log_vec *lv; | |
345 | ||
346 | for (lv = log_vector; lv; ) { | |
347 | struct xfs_log_vec *next = lv->lv_next; | |
348 | kmem_free(lv->lv_buf); | |
349 | kmem_free(lv); | |
350 | lv = next; | |
351 | } | |
352 | } | |
353 | ||
71e330b5 DC |
354 | /* |
355 | * Mark all items committed and clear busy extents. We free the log vector | |
356 | * chains in a separate pass so that we unpin the log items as quickly as | |
357 | * possible. | |
358 | */ | |
359 | static void | |
360 | xlog_cil_committed( | |
361 | void *args, | |
362 | int abort) | |
363 | { | |
364 | struct xfs_cil_ctx *ctx = args; | |
e84661aa | 365 | struct xfs_mount *mp = ctx->cil->xc_log->l_mp; |
71e330b5 | 366 | |
0e57f6a3 DC |
367 | xfs_trans_committed_bulk(ctx->cil->xc_log->l_ailp, ctx->lv_chain, |
368 | ctx->start_lsn, abort); | |
71e330b5 | 369 | |
8a072a4d | 370 | xfs_alloc_busy_sort(&ctx->busy_extents); |
e84661aa CH |
371 | xfs_alloc_busy_clear(mp, &ctx->busy_extents, |
372 | (mp->m_flags & XFS_MOUNT_DISCARD) && !abort); | |
71e330b5 DC |
373 | |
374 | spin_lock(&ctx->cil->xc_cil_lock); | |
375 | list_del(&ctx->committing); | |
376 | spin_unlock(&ctx->cil->xc_cil_lock); | |
377 | ||
378 | xlog_cil_free_logvec(ctx->lv_chain); | |
e84661aa CH |
379 | |
380 | if (!list_empty(&ctx->busy_extents)) { | |
381 | ASSERT(mp->m_flags & XFS_MOUNT_DISCARD); | |
382 | ||
383 | xfs_discard_extents(mp, &ctx->busy_extents); | |
384 | xfs_alloc_busy_clear(mp, &ctx->busy_extents, false); | |
385 | } | |
386 | ||
71e330b5 DC |
387 | kmem_free(ctx); |
388 | } | |
389 | ||
390 | /* | |
a44f13ed DC |
391 | * Push the Committed Item List to the log. If @push_seq flag is zero, then it |
392 | * is a background flush and so we can chose to ignore it. Otherwise, if the | |
393 | * current sequence is the same as @push_seq we need to do a flush. If | |
394 | * @push_seq is less than the current sequence, then it has already been | |
395 | * flushed and we don't need to do anything - the caller will wait for it to | |
396 | * complete if necessary. | |
397 | * | |
398 | * @push_seq is a value rather than a flag because that allows us to do an | |
399 | * unlocked check of the sequence number for a match. Hence we can allows log | |
400 | * forces to run racily and not issue pushes for the same sequence twice. If we | |
401 | * get a race between multiple pushes for the same sequence they will block on | |
402 | * the first one and then abort, hence avoiding needless pushes. | |
71e330b5 | 403 | */ |
a44f13ed | 404 | STATIC int |
71e330b5 DC |
405 | xlog_cil_push( |
406 | struct log *log, | |
a44f13ed | 407 | xfs_lsn_t push_seq) |
71e330b5 DC |
408 | { |
409 | struct xfs_cil *cil = log->l_cilp; | |
410 | struct xfs_log_vec *lv; | |
411 | struct xfs_cil_ctx *ctx; | |
412 | struct xfs_cil_ctx *new_ctx; | |
413 | struct xlog_in_core *commit_iclog; | |
414 | struct xlog_ticket *tic; | |
415 | int num_lv; | |
416 | int num_iovecs; | |
417 | int len; | |
418 | int error = 0; | |
419 | struct xfs_trans_header thdr; | |
420 | struct xfs_log_iovec lhdr; | |
421 | struct xfs_log_vec lvhdr = { NULL }; | |
422 | xfs_lsn_t commit_lsn; | |
423 | ||
424 | if (!cil) | |
425 | return 0; | |
426 | ||
a44f13ed DC |
427 | ASSERT(!push_seq || push_seq <= cil->xc_ctx->sequence); |
428 | ||
71e330b5 DC |
429 | new_ctx = kmem_zalloc(sizeof(*new_ctx), KM_SLEEP|KM_NOFS); |
430 | new_ctx->ticket = xlog_cil_ticket_alloc(log); | |
431 | ||
80168676 DC |
432 | /* |
433 | * Lock out transaction commit, but don't block for background pushes | |
434 | * unless we are well over the CIL space limit. See the definition of | |
435 | * XLOG_CIL_HARD_SPACE_LIMIT() for the full explanation of the logic | |
436 | * used here. | |
437 | */ | |
df806158 | 438 | if (!down_write_trylock(&cil->xc_ctx_lock)) { |
80168676 DC |
439 | if (!push_seq && |
440 | cil->xc_ctx->space_used < XLOG_CIL_HARD_SPACE_LIMIT(log)) | |
df806158 DC |
441 | goto out_free_ticket; |
442 | down_write(&cil->xc_ctx_lock); | |
443 | } | |
71e330b5 DC |
444 | ctx = cil->xc_ctx; |
445 | ||
446 | /* check if we've anything to push */ | |
447 | if (list_empty(&cil->xc_cil)) | |
448 | goto out_skip; | |
449 | ||
df806158 | 450 | /* check for spurious background flush */ |
a44f13ed DC |
451 | if (!push_seq && cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log)) |
452 | goto out_skip; | |
453 | ||
454 | /* check for a previously pushed seqeunce */ | |
80168676 | 455 | if (push_seq && push_seq < cil->xc_ctx->sequence) |
df806158 DC |
456 | goto out_skip; |
457 | ||
71e330b5 DC |
458 | /* |
459 | * pull all the log vectors off the items in the CIL, and | |
460 | * remove the items from the CIL. We don't need the CIL lock | |
461 | * here because it's only needed on the transaction commit | |
462 | * side which is currently locked out by the flush lock. | |
463 | */ | |
464 | lv = NULL; | |
465 | num_lv = 0; | |
466 | num_iovecs = 0; | |
467 | len = 0; | |
468 | while (!list_empty(&cil->xc_cil)) { | |
469 | struct xfs_log_item *item; | |
470 | int i; | |
471 | ||
472 | item = list_first_entry(&cil->xc_cil, | |
473 | struct xfs_log_item, li_cil); | |
474 | list_del_init(&item->li_cil); | |
475 | if (!ctx->lv_chain) | |
476 | ctx->lv_chain = item->li_lv; | |
477 | else | |
478 | lv->lv_next = item->li_lv; | |
479 | lv = item->li_lv; | |
480 | item->li_lv = NULL; | |
481 | ||
482 | num_lv++; | |
483 | num_iovecs += lv->lv_niovecs; | |
484 | for (i = 0; i < lv->lv_niovecs; i++) | |
485 | len += lv->lv_iovecp[i].i_len; | |
486 | } | |
487 | ||
488 | /* | |
489 | * initialise the new context and attach it to the CIL. Then attach | |
490 | * the current context to the CIL committing lsit so it can be found | |
491 | * during log forces to extract the commit lsn of the sequence that | |
492 | * needs to be forced. | |
493 | */ | |
494 | INIT_LIST_HEAD(&new_ctx->committing); | |
495 | INIT_LIST_HEAD(&new_ctx->busy_extents); | |
496 | new_ctx->sequence = ctx->sequence + 1; | |
497 | new_ctx->cil = cil; | |
498 | cil->xc_ctx = new_ctx; | |
499 | ||
a44f13ed DC |
500 | /* |
501 | * mirror the new sequence into the cil structure so that we can do | |
502 | * unlocked checks against the current sequence in log forces without | |
503 | * risking deferencing a freed context pointer. | |
504 | */ | |
505 | cil->xc_current_sequence = new_ctx->sequence; | |
506 | ||
71e330b5 DC |
507 | /* |
508 | * The switch is now done, so we can drop the context lock and move out | |
509 | * of a shared context. We can't just go straight to the commit record, | |
510 | * though - we need to synchronise with previous and future commits so | |
511 | * that the commit records are correctly ordered in the log to ensure | |
512 | * that we process items during log IO completion in the correct order. | |
513 | * | |
514 | * For example, if we get an EFI in one checkpoint and the EFD in the | |
515 | * next (e.g. due to log forces), we do not want the checkpoint with | |
516 | * the EFD to be committed before the checkpoint with the EFI. Hence | |
517 | * we must strictly order the commit records of the checkpoints so | |
518 | * that: a) the checkpoint callbacks are attached to the iclogs in the | |
519 | * correct order; and b) the checkpoints are replayed in correct order | |
520 | * in log recovery. | |
521 | * | |
522 | * Hence we need to add this context to the committing context list so | |
523 | * that higher sequences will wait for us to write out a commit record | |
524 | * before they do. | |
525 | */ | |
526 | spin_lock(&cil->xc_cil_lock); | |
527 | list_add(&ctx->committing, &cil->xc_committing); | |
528 | spin_unlock(&cil->xc_cil_lock); | |
529 | up_write(&cil->xc_ctx_lock); | |
530 | ||
531 | /* | |
532 | * Build a checkpoint transaction header and write it to the log to | |
533 | * begin the transaction. We need to account for the space used by the | |
534 | * transaction header here as it is not accounted for in xlog_write(). | |
535 | * | |
536 | * The LSN we need to pass to the log items on transaction commit is | |
537 | * the LSN reported by the first log vector write. If we use the commit | |
538 | * record lsn then we can move the tail beyond the grant write head. | |
539 | */ | |
540 | tic = ctx->ticket; | |
541 | thdr.th_magic = XFS_TRANS_HEADER_MAGIC; | |
542 | thdr.th_type = XFS_TRANS_CHECKPOINT; | |
543 | thdr.th_tid = tic->t_tid; | |
544 | thdr.th_num_items = num_iovecs; | |
4e0d5f92 | 545 | lhdr.i_addr = &thdr; |
71e330b5 DC |
546 | lhdr.i_len = sizeof(xfs_trans_header_t); |
547 | lhdr.i_type = XLOG_REG_TYPE_TRANSHDR; | |
548 | tic->t_curr_res -= lhdr.i_len + sizeof(xlog_op_header_t); | |
549 | ||
550 | lvhdr.lv_niovecs = 1; | |
551 | lvhdr.lv_iovecp = &lhdr; | |
552 | lvhdr.lv_next = ctx->lv_chain; | |
553 | ||
554 | error = xlog_write(log, &lvhdr, tic, &ctx->start_lsn, NULL, 0); | |
555 | if (error) | |
7db37c5e | 556 | goto out_abort_free_ticket; |
71e330b5 DC |
557 | |
558 | /* | |
559 | * now that we've written the checkpoint into the log, strictly | |
560 | * order the commit records so replay will get them in the right order. | |
561 | */ | |
562 | restart: | |
563 | spin_lock(&cil->xc_cil_lock); | |
564 | list_for_each_entry(new_ctx, &cil->xc_committing, committing) { | |
565 | /* | |
566 | * Higher sequences will wait for this one so skip them. | |
567 | * Don't wait for own own sequence, either. | |
568 | */ | |
569 | if (new_ctx->sequence >= ctx->sequence) | |
570 | continue; | |
571 | if (!new_ctx->commit_lsn) { | |
572 | /* | |
573 | * It is still being pushed! Wait for the push to | |
574 | * complete, then start again from the beginning. | |
575 | */ | |
eb40a875 | 576 | xlog_wait(&cil->xc_commit_wait, &cil->xc_cil_lock); |
71e330b5 DC |
577 | goto restart; |
578 | } | |
579 | } | |
580 | spin_unlock(&cil->xc_cil_lock); | |
581 | ||
7db37c5e | 582 | /* xfs_log_done always frees the ticket on error. */ |
71e330b5 | 583 | commit_lsn = xfs_log_done(log->l_mp, tic, &commit_iclog, 0); |
7db37c5e | 584 | if (commit_lsn == -1) |
71e330b5 DC |
585 | goto out_abort; |
586 | ||
587 | /* attach all the transactions w/ busy extents to iclog */ | |
588 | ctx->log_cb.cb_func = xlog_cil_committed; | |
589 | ctx->log_cb.cb_arg = ctx; | |
590 | error = xfs_log_notify(log->l_mp, commit_iclog, &ctx->log_cb); | |
591 | if (error) | |
592 | goto out_abort; | |
593 | ||
594 | /* | |
595 | * now the checkpoint commit is complete and we've attached the | |
596 | * callbacks to the iclog we can assign the commit LSN to the context | |
597 | * and wake up anyone who is waiting for the commit to complete. | |
598 | */ | |
599 | spin_lock(&cil->xc_cil_lock); | |
600 | ctx->commit_lsn = commit_lsn; | |
eb40a875 | 601 | wake_up_all(&cil->xc_commit_wait); |
71e330b5 DC |
602 | spin_unlock(&cil->xc_cil_lock); |
603 | ||
604 | /* release the hounds! */ | |
605 | return xfs_log_release_iclog(log->l_mp, commit_iclog); | |
606 | ||
607 | out_skip: | |
608 | up_write(&cil->xc_ctx_lock); | |
df806158 | 609 | out_free_ticket: |
71e330b5 DC |
610 | xfs_log_ticket_put(new_ctx->ticket); |
611 | kmem_free(new_ctx); | |
612 | return 0; | |
613 | ||
7db37c5e DC |
614 | out_abort_free_ticket: |
615 | xfs_log_ticket_put(tic); | |
71e330b5 DC |
616 | out_abort: |
617 | xlog_cil_committed(ctx, XFS_LI_ABORTED); | |
618 | return XFS_ERROR(EIO); | |
619 | } | |
620 | ||
a44f13ed DC |
621 | /* |
622 | * Commit a transaction with the given vector to the Committed Item List. | |
623 | * | |
624 | * To do this, we need to format the item, pin it in memory if required and | |
625 | * account for the space used by the transaction. Once we have done that we | |
626 | * need to release the unused reservation for the transaction, attach the | |
627 | * transaction to the checkpoint context so we carry the busy extents through | |
628 | * to checkpoint completion, and then unlock all the items in the transaction. | |
629 | * | |
630 | * For more specific information about the order of operations in | |
631 | * xfs_log_commit_cil() please refer to the comments in | |
632 | * xfs_trans_commit_iclog(). | |
633 | * | |
634 | * Called with the context lock already held in read mode to lock out | |
635 | * background commit, returns without it held once background commits are | |
636 | * allowed again. | |
637 | */ | |
c6f990d1 | 638 | void |
a44f13ed DC |
639 | xfs_log_commit_cil( |
640 | struct xfs_mount *mp, | |
641 | struct xfs_trans *tp, | |
642 | struct xfs_log_vec *log_vector, | |
643 | xfs_lsn_t *commit_lsn, | |
644 | int flags) | |
645 | { | |
646 | struct log *log = mp->m_log; | |
647 | int log_flags = 0; | |
648 | int push = 0; | |
649 | ||
650 | if (flags & XFS_TRANS_RELEASE_LOG_RES) | |
651 | log_flags = XFS_LOG_REL_PERM_RESERV; | |
652 | ||
3b93c7aa DC |
653 | /* |
654 | * do all the hard work of formatting items (including memory | |
655 | * allocation) outside the CIL context lock. This prevents stalling CIL | |
656 | * pushes when we are low on memory and a transaction commit spends a | |
657 | * lot of time in memory reclaim. | |
658 | */ | |
659 | xlog_cil_format_items(log, log_vector); | |
660 | ||
a44f13ed DC |
661 | /* lock out background commit */ |
662 | down_read(&log->l_cilp->xc_ctx_lock); | |
d1583a38 DC |
663 | if (commit_lsn) |
664 | *commit_lsn = log->l_cilp->xc_ctx->sequence; | |
665 | ||
666 | xlog_cil_insert_items(log, log_vector, tp->t_ticket); | |
a44f13ed DC |
667 | |
668 | /* check we didn't blow the reservation */ | |
669 | if (tp->t_ticket->t_curr_res < 0) | |
670 | xlog_print_tic_res(log->l_mp, tp->t_ticket); | |
671 | ||
672 | /* attach the transaction to the CIL if it has any busy extents */ | |
673 | if (!list_empty(&tp->t_busy)) { | |
674 | spin_lock(&log->l_cilp->xc_cil_lock); | |
675 | list_splice_init(&tp->t_busy, | |
676 | &log->l_cilp->xc_ctx->busy_extents); | |
677 | spin_unlock(&log->l_cilp->xc_cil_lock); | |
678 | } | |
679 | ||
680 | tp->t_commit_lsn = *commit_lsn; | |
681 | xfs_log_done(mp, tp->t_ticket, NULL, log_flags); | |
682 | xfs_trans_unreserve_and_mod_sb(tp); | |
683 | ||
684 | /* | |
685 | * Once all the items of the transaction have been copied to the CIL, | |
686 | * the items can be unlocked and freed. | |
687 | * | |
688 | * This needs to be done before we drop the CIL context lock because we | |
689 | * have to update state in the log items and unlock them before they go | |
690 | * to disk. If we don't, then the CIL checkpoint can race with us and | |
691 | * we can run checkpoint completion before we've updated and unlocked | |
692 | * the log items. This affects (at least) processing of stale buffers, | |
693 | * inodes and EFIs. | |
694 | */ | |
695 | xfs_trans_free_items(tp, *commit_lsn, 0); | |
696 | ||
697 | /* check for background commit before unlock */ | |
698 | if (log->l_cilp->xc_ctx->space_used > XLOG_CIL_SPACE_LIMIT(log)) | |
699 | push = 1; | |
700 | ||
701 | up_read(&log->l_cilp->xc_ctx_lock); | |
702 | ||
703 | /* | |
704 | * We need to push CIL every so often so we don't cache more than we | |
705 | * can fit in the log. The limit really is that a checkpoint can't be | |
706 | * more than half the log (the current checkpoint is not allowed to | |
707 | * overwrite the previous checkpoint), but commit latency and memory | |
708 | * usage limit this to a smaller size in most cases. | |
709 | */ | |
710 | if (push) | |
711 | xlog_cil_push(log, 0); | |
a44f13ed DC |
712 | } |
713 | ||
71e330b5 DC |
714 | /* |
715 | * Conditionally push the CIL based on the sequence passed in. | |
716 | * | |
717 | * We only need to push if we haven't already pushed the sequence | |
718 | * number given. Hence the only time we will trigger a push here is | |
719 | * if the push sequence is the same as the current context. | |
720 | * | |
721 | * We return the current commit lsn to allow the callers to determine if a | |
722 | * iclog flush is necessary following this call. | |
723 | * | |
724 | * XXX: Initially, just push the CIL unconditionally and return whatever | |
725 | * commit lsn is there. It'll be empty, so this is broken for now. | |
726 | */ | |
727 | xfs_lsn_t | |
a44f13ed | 728 | xlog_cil_force_lsn( |
71e330b5 | 729 | struct log *log, |
a44f13ed | 730 | xfs_lsn_t sequence) |
71e330b5 DC |
731 | { |
732 | struct xfs_cil *cil = log->l_cilp; | |
733 | struct xfs_cil_ctx *ctx; | |
734 | xfs_lsn_t commit_lsn = NULLCOMMITLSN; | |
735 | ||
a44f13ed DC |
736 | ASSERT(sequence <= cil->xc_current_sequence); |
737 | ||
738 | /* | |
739 | * check to see if we need to force out the current context. | |
740 | * xlog_cil_push() handles racing pushes for the same sequence, | |
741 | * so no need to deal with it here. | |
742 | */ | |
743 | if (sequence == cil->xc_current_sequence) | |
744 | xlog_cil_push(log, sequence); | |
71e330b5 DC |
745 | |
746 | /* | |
747 | * See if we can find a previous sequence still committing. | |
71e330b5 DC |
748 | * We need to wait for all previous sequence commits to complete |
749 | * before allowing the force of push_seq to go ahead. Hence block | |
750 | * on commits for those as well. | |
751 | */ | |
a44f13ed | 752 | restart: |
71e330b5 | 753 | spin_lock(&cil->xc_cil_lock); |
71e330b5 | 754 | list_for_each_entry(ctx, &cil->xc_committing, committing) { |
a44f13ed | 755 | if (ctx->sequence > sequence) |
71e330b5 DC |
756 | continue; |
757 | if (!ctx->commit_lsn) { | |
758 | /* | |
759 | * It is still being pushed! Wait for the push to | |
760 | * complete, then start again from the beginning. | |
761 | */ | |
eb40a875 | 762 | xlog_wait(&cil->xc_commit_wait, &cil->xc_cil_lock); |
71e330b5 DC |
763 | goto restart; |
764 | } | |
a44f13ed | 765 | if (ctx->sequence != sequence) |
71e330b5 DC |
766 | continue; |
767 | /* found it! */ | |
768 | commit_lsn = ctx->commit_lsn; | |
769 | } | |
770 | spin_unlock(&cil->xc_cil_lock); | |
771 | return commit_lsn; | |
772 | } | |
ccf7c23f DC |
773 | |
774 | /* | |
775 | * Check if the current log item was first committed in this sequence. | |
776 | * We can't rely on just the log item being in the CIL, we have to check | |
777 | * the recorded commit sequence number. | |
778 | * | |
779 | * Note: for this to be used in a non-racy manner, it has to be called with | |
780 | * CIL flushing locked out. As a result, it should only be used during the | |
781 | * transaction commit process when deciding what to format into the item. | |
782 | */ | |
783 | bool | |
784 | xfs_log_item_in_current_chkpt( | |
785 | struct xfs_log_item *lip) | |
786 | { | |
787 | struct xfs_cil_ctx *ctx; | |
788 | ||
789 | if (!(lip->li_mountp->m_flags & XFS_MOUNT_DELAYLOG)) | |
790 | return false; | |
791 | if (list_empty(&lip->li_cil)) | |
792 | return false; | |
793 | ||
794 | ctx = lip->li_mountp->m_log->l_cilp->xc_ctx; | |
795 | ||
796 | /* | |
797 | * li_seq is written on the first commit of a log item to record the | |
798 | * first checkpoint it is written to. Hence if it is different to the | |
799 | * current sequence, we're in a new checkpoint. | |
800 | */ | |
801 | if (XFS_LSN_CMP(lip->li_seq, ctx->sequence) != 0) | |
802 | return false; | |
803 | return true; | |
804 | } |