Commit | Line | Data |
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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" | |
239880ef | 20 | #include "xfs_log_format.h" |
70a9883c | 21 | #include "xfs_shared.h" |
239880ef | 22 | #include "xfs_trans_resv.h" |
71e330b5 DC |
23 | #include "xfs_sb.h" |
24 | #include "xfs_ag.h" | |
71e330b5 DC |
25 | #include "xfs_mount.h" |
26 | #include "xfs_error.h" | |
27 | #include "xfs_alloc.h" | |
efc27b52 | 28 | #include "xfs_extent_busy.h" |
e84661aa | 29 | #include "xfs_discard.h" |
239880ef DC |
30 | #include "xfs_trans.h" |
31 | #include "xfs_trans_priv.h" | |
32 | #include "xfs_log.h" | |
33 | #include "xfs_log_priv.h" | |
71e330b5 | 34 | |
71e330b5 DC |
35 | /* |
36 | * Allocate a new ticket. Failing to get a new ticket makes it really hard to | |
37 | * recover, so we don't allow failure here. Also, we allocate in a context that | |
38 | * we don't want to be issuing transactions from, so we need to tell the | |
39 | * allocation code this as well. | |
40 | * | |
41 | * We don't reserve any space for the ticket - we are going to steal whatever | |
42 | * space we require from transactions as they commit. To ensure we reserve all | |
43 | * the space required, we need to set the current reservation of the ticket to | |
44 | * zero so that we know to steal the initial transaction overhead from the | |
45 | * first transaction commit. | |
46 | */ | |
47 | static struct xlog_ticket * | |
48 | xlog_cil_ticket_alloc( | |
f7bdf03a | 49 | struct xlog *log) |
71e330b5 DC |
50 | { |
51 | struct xlog_ticket *tic; | |
52 | ||
53 | tic = xlog_ticket_alloc(log, 0, 1, XFS_TRANSACTION, 0, | |
54 | KM_SLEEP|KM_NOFS); | |
55 | tic->t_trans_type = XFS_TRANS_CHECKPOINT; | |
56 | ||
57 | /* | |
58 | * set the current reservation to zero so we know to steal the basic | |
59 | * transaction overhead reservation from the first transaction commit. | |
60 | */ | |
61 | tic->t_curr_res = 0; | |
62 | return tic; | |
63 | } | |
64 | ||
65 | /* | |
66 | * After the first stage of log recovery is done, we know where the head and | |
67 | * tail of the log are. We need this log initialisation done before we can | |
68 | * initialise the first CIL checkpoint context. | |
69 | * | |
70 | * Here we allocate a log ticket to track space usage during a CIL push. This | |
71 | * ticket is passed to xlog_write() directly so that we don't slowly leak log | |
72 | * space by failing to account for space used by log headers and additional | |
73 | * region headers for split regions. | |
74 | */ | |
75 | void | |
76 | xlog_cil_init_post_recovery( | |
f7bdf03a | 77 | struct xlog *log) |
71e330b5 | 78 | { |
71e330b5 DC |
79 | log->l_cilp->xc_ctx->ticket = xlog_cil_ticket_alloc(log); |
80 | log->l_cilp->xc_ctx->sequence = 1; | |
81 | log->l_cilp->xc_ctx->commit_lsn = xlog_assign_lsn(log->l_curr_cycle, | |
82 | log->l_curr_block); | |
83 | } | |
84 | ||
991aaf65 DC |
85 | /* |
86 | * Prepare the log item for insertion into the CIL. Calculate the difference in | |
87 | * log space and vectors it will consume, and if it is a new item pin it as | |
88 | * well. | |
89 | */ | |
90 | STATIC void | |
91 | xfs_cil_prepare_item( | |
92 | struct xlog *log, | |
93 | struct xfs_log_vec *lv, | |
94 | struct xfs_log_vec *old_lv, | |
95 | int *diff_len, | |
96 | int *diff_iovecs) | |
97 | { | |
98 | /* Account for the new LV being passed in */ | |
99 | if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED) { | |
110dc24a | 100 | *diff_len += lv->lv_bytes; |
991aaf65 DC |
101 | *diff_iovecs += lv->lv_niovecs; |
102 | } | |
103 | ||
104 | /* | |
105 | * If there is no old LV, this is the first time we've seen the item in | |
106 | * this CIL context and so we need to pin it. If we are replacing the | |
107 | * old_lv, then remove the space it accounts for and free it. | |
108 | */ | |
109 | if (!old_lv) | |
110 | lv->lv_item->li_ops->iop_pin(lv->lv_item); | |
111 | else if (old_lv != lv) { | |
112 | ASSERT(lv->lv_buf_len != XFS_LOG_VEC_ORDERED); | |
113 | ||
110dc24a | 114 | *diff_len -= old_lv->lv_bytes; |
991aaf65 DC |
115 | *diff_iovecs -= old_lv->lv_niovecs; |
116 | kmem_free(old_lv); | |
117 | } | |
118 | ||
119 | /* attach new log vector to log item */ | |
120 | lv->lv_item->li_lv = lv; | |
121 | ||
122 | /* | |
123 | * If this is the first time the item is being committed to the | |
124 | * CIL, store the sequence number on the log item so we can | |
125 | * tell in future commits whether this is the first checkpoint | |
126 | * the item is being committed into. | |
127 | */ | |
128 | if (!lv->lv_item->li_seq) | |
129 | lv->lv_item->li_seq = log->l_cilp->xc_ctx->sequence; | |
130 | } | |
131 | ||
71e330b5 DC |
132 | /* |
133 | * Format log item into a flat buffers | |
134 | * | |
135 | * For delayed logging, we need to hold a formatted buffer containing all the | |
136 | * changes on the log item. This enables us to relog the item in memory and | |
137 | * write it out asynchronously without needing to relock the object that was | |
138 | * modified at the time it gets written into the iclog. | |
139 | * | |
140 | * This function builds a vector for the changes in each log item in the | |
141 | * transaction. It then works out the length of the buffer needed for each log | |
142 | * item, allocates them and formats the vector for the item into the buffer. | |
143 | * The buffer is then attached to the log item are then inserted into the | |
144 | * Committed Item List for tracking until the next checkpoint is written out. | |
145 | * | |
146 | * We don't set up region headers during this process; we simply copy the | |
147 | * regions into the flat buffer. We can do this because we still have to do a | |
148 | * formatting step to write the regions into the iclog buffer. Writing the | |
149 | * ophdrs during the iclog write means that we can support splitting large | |
150 | * regions across iclog boundares without needing a change in the format of the | |
151 | * item/region encapsulation. | |
152 | * | |
153 | * Hence what we need to do now is change the rewrite the vector array to point | |
154 | * to the copied region inside the buffer we just allocated. This allows us to | |
155 | * format the regions into the iclog as though they are being formatted | |
156 | * directly out of the objects themselves. | |
157 | */ | |
991aaf65 DC |
158 | static void |
159 | xlog_cil_insert_format_items( | |
160 | struct xlog *log, | |
161 | struct xfs_trans *tp, | |
162 | int *diff_len, | |
163 | int *diff_iovecs) | |
71e330b5 | 164 | { |
0244b960 | 165 | struct xfs_log_item_desc *lidp; |
71e330b5 | 166 | |
0244b960 CH |
167 | |
168 | /* Bail out if we didn't find a log item. */ | |
169 | if (list_empty(&tp->t_items)) { | |
170 | ASSERT(0); | |
991aaf65 | 171 | return; |
0244b960 CH |
172 | } |
173 | ||
174 | list_for_each_entry(lidp, &tp->t_items, lid_trans) { | |
166d1368 | 175 | struct xfs_log_item *lip = lidp->lid_item; |
7492c5b4 | 176 | struct xfs_log_vec *lv; |
991aaf65 | 177 | struct xfs_log_vec *old_lv; |
7492c5b4 DC |
178 | int niovecs = 0; |
179 | int nbytes = 0; | |
180 | int buf_size; | |
fd63875c | 181 | bool ordered = false; |
71e330b5 | 182 | |
0244b960 CH |
183 | /* Skip items which aren't dirty in this transaction. */ |
184 | if (!(lidp->lid_flags & XFS_LID_DIRTY)) | |
185 | continue; | |
186 | ||
166d1368 DC |
187 | /* get number of vecs and size of data to be stored */ |
188 | lip->li_ops->iop_size(lip, &niovecs, &nbytes); | |
189 | ||
0244b960 | 190 | /* Skip items that do not have any vectors for writing */ |
b3934213 | 191 | if (!niovecs) |
0244b960 CH |
192 | continue; |
193 | ||
fd63875c DC |
194 | /* |
195 | * Ordered items need to be tracked but we do not wish to write | |
196 | * them. We need a logvec to track the object, but we do not | |
197 | * need an iovec or buffer to be allocated for copying data. | |
198 | */ | |
199 | if (niovecs == XFS_LOG_VEC_ORDERED) { | |
200 | ordered = true; | |
201 | niovecs = 0; | |
7492c5b4 | 202 | nbytes = 0; |
fd63875c DC |
203 | } |
204 | ||
bde7cff6 CH |
205 | /* |
206 | * We 64-bit align the length of each iovec so that the start | |
207 | * of the next one is naturally aligned. We'll need to | |
3895e51f DC |
208 | * account for that slack space here. Then round nbytes up |
209 | * to 64-bit alignment so that the initial buffer alignment is | |
210 | * easy to calculate and verify. | |
bde7cff6 CH |
211 | */ |
212 | nbytes += niovecs * sizeof(uint64_t); | |
3895e51f | 213 | nbytes = round_up(nbytes, sizeof(uint64_t)); |
bde7cff6 | 214 | |
991aaf65 DC |
215 | /* grab the old item if it exists for reservation accounting */ |
216 | old_lv = lip->li_lv; | |
217 | ||
3895e51f DC |
218 | /* |
219 | * The data buffer needs to start 64-bit aligned, so round up | |
220 | * that space to ensure we can align it appropriately and not | |
221 | * overrun the buffer. | |
222 | */ | |
223 | buf_size = nbytes + | |
224 | round_up((sizeof(struct xfs_log_vec) + | |
225 | niovecs * sizeof(struct xfs_log_iovec)), | |
226 | sizeof(uint64_t)); | |
0244b960 | 227 | |
f5baac35 DC |
228 | /* compare to existing item size */ |
229 | if (lip->li_lv && buf_size <= lip->li_lv->lv_size) { | |
230 | /* same or smaller, optimise common overwrite case */ | |
231 | lv = lip->li_lv; | |
232 | lv->lv_next = NULL; | |
233 | ||
234 | if (ordered) | |
235 | goto insert; | |
236 | ||
991aaf65 DC |
237 | /* |
238 | * set the item up as though it is a new insertion so | |
239 | * that the space reservation accounting is correct. | |
240 | */ | |
241 | *diff_iovecs -= lv->lv_niovecs; | |
110dc24a | 242 | *diff_len -= lv->lv_bytes; |
9597df6b CH |
243 | } else { |
244 | /* allocate new data chunk */ | |
245 | lv = kmem_zalloc(buf_size, KM_SLEEP|KM_NOFS); | |
246 | lv->lv_item = lip; | |
247 | lv->lv_size = buf_size; | |
248 | if (ordered) { | |
249 | /* track as an ordered logvec */ | |
250 | ASSERT(lip->li_lv == NULL); | |
251 | lv->lv_buf_len = XFS_LOG_VEC_ORDERED; | |
252 | goto insert; | |
253 | } | |
254 | lv->lv_iovecp = (struct xfs_log_iovec *)&lv[1]; | |
f5baac35 DC |
255 | } |
256 | ||
9597df6b | 257 | /* Ensure the lv is set up according to ->iop_size */ |
7492c5b4 | 258 | lv->lv_niovecs = niovecs; |
71e330b5 | 259 | |
7492c5b4 | 260 | /* The allocated data region lies beyond the iovec region */ |
bde7cff6 | 261 | lv->lv_buf_len = 0; |
110dc24a | 262 | lv->lv_bytes = 0; |
7492c5b4 | 263 | lv->lv_buf = (char *)lv + buf_size - nbytes; |
3895e51f DC |
264 | ASSERT(IS_ALIGNED((unsigned long)lv->lv_buf, sizeof(uint64_t))); |
265 | ||
bde7cff6 | 266 | lip->li_ops->iop_format(lip, lv); |
7492c5b4 | 267 | insert: |
f5baac35 | 268 | ASSERT(lv->lv_buf_len <= nbytes); |
991aaf65 | 269 | xfs_cil_prepare_item(log, lv, old_lv, diff_len, diff_iovecs); |
3b93c7aa | 270 | } |
d1583a38 DC |
271 | } |
272 | ||
273 | /* | |
274 | * Insert the log items into the CIL and calculate the difference in space | |
275 | * consumed by the item. Add the space to the checkpoint ticket and calculate | |
276 | * if the change requires additional log metadata. If it does, take that space | |
42b2aa86 | 277 | * as well. Remove the amount of space we added to the checkpoint ticket from |
d1583a38 DC |
278 | * the current transaction ticket so that the accounting works out correctly. |
279 | */ | |
3b93c7aa DC |
280 | static void |
281 | xlog_cil_insert_items( | |
f7bdf03a | 282 | struct xlog *log, |
991aaf65 | 283 | struct xfs_trans *tp) |
3b93c7aa | 284 | { |
d1583a38 DC |
285 | struct xfs_cil *cil = log->l_cilp; |
286 | struct xfs_cil_ctx *ctx = cil->xc_ctx; | |
991aaf65 | 287 | struct xfs_log_item_desc *lidp; |
d1583a38 DC |
288 | int len = 0; |
289 | int diff_iovecs = 0; | |
290 | int iclog_space; | |
3b93c7aa | 291 | |
991aaf65 | 292 | ASSERT(tp); |
d1583a38 DC |
293 | |
294 | /* | |
d1583a38 DC |
295 | * We can do this safely because the context can't checkpoint until we |
296 | * are done so it doesn't matter exactly how we update the CIL. | |
297 | */ | |
991aaf65 DC |
298 | xlog_cil_insert_format_items(log, tp, &len, &diff_iovecs); |
299 | ||
300 | /* | |
301 | * Now (re-)position everything modified at the tail of the CIL. | |
302 | * We do this here so we only need to take the CIL lock once during | |
303 | * the transaction commit. | |
304 | */ | |
d1583a38 | 305 | spin_lock(&cil->xc_cil_lock); |
991aaf65 DC |
306 | list_for_each_entry(lidp, &tp->t_items, lid_trans) { |
307 | struct xfs_log_item *lip = lidp->lid_item; | |
d1583a38 | 308 | |
991aaf65 DC |
309 | /* Skip items which aren't dirty in this transaction. */ |
310 | if (!(lidp->lid_flags & XFS_LID_DIRTY)) | |
311 | continue; | |
fd63875c | 312 | |
991aaf65 | 313 | list_move_tail(&lip->li_cil, &cil->xc_cil); |
fd63875c | 314 | } |
d1583a38 | 315 | |
fd63875c DC |
316 | /* account for space used by new iovec headers */ |
317 | len += diff_iovecs * sizeof(xlog_op_header_t); | |
d1583a38 DC |
318 | ctx->nvecs += diff_iovecs; |
319 | ||
991aaf65 DC |
320 | /* attach the transaction to the CIL if it has any busy extents */ |
321 | if (!list_empty(&tp->t_busy)) | |
322 | list_splice_init(&tp->t_busy, &ctx->busy_extents); | |
323 | ||
d1583a38 DC |
324 | /* |
325 | * Now transfer enough transaction reservation to the context ticket | |
326 | * for the checkpoint. The context ticket is special - the unit | |
327 | * reservation has to grow as well as the current reservation as we | |
328 | * steal from tickets so we can correctly determine the space used | |
329 | * during the transaction commit. | |
330 | */ | |
331 | if (ctx->ticket->t_curr_res == 0) { | |
d1583a38 | 332 | ctx->ticket->t_curr_res = ctx->ticket->t_unit_res; |
991aaf65 | 333 | tp->t_ticket->t_curr_res -= ctx->ticket->t_unit_res; |
d1583a38 DC |
334 | } |
335 | ||
336 | /* do we need space for more log record headers? */ | |
337 | iclog_space = log->l_iclog_size - log->l_iclog_hsize; | |
338 | if (len > 0 && (ctx->space_used / iclog_space != | |
339 | (ctx->space_used + len) / iclog_space)) { | |
340 | int hdrs; | |
341 | ||
342 | hdrs = (len + iclog_space - 1) / iclog_space; | |
343 | /* need to take into account split region headers, too */ | |
344 | hdrs *= log->l_iclog_hsize + sizeof(struct xlog_op_header); | |
345 | ctx->ticket->t_unit_res += hdrs; | |
346 | ctx->ticket->t_curr_res += hdrs; | |
991aaf65 DC |
347 | tp->t_ticket->t_curr_res -= hdrs; |
348 | ASSERT(tp->t_ticket->t_curr_res >= len); | |
d1583a38 | 349 | } |
991aaf65 | 350 | tp->t_ticket->t_curr_res -= len; |
d1583a38 DC |
351 | ctx->space_used += len; |
352 | ||
353 | spin_unlock(&cil->xc_cil_lock); | |
71e330b5 DC |
354 | } |
355 | ||
356 | static void | |
357 | xlog_cil_free_logvec( | |
358 | struct xfs_log_vec *log_vector) | |
359 | { | |
360 | struct xfs_log_vec *lv; | |
361 | ||
362 | for (lv = log_vector; lv; ) { | |
363 | struct xfs_log_vec *next = lv->lv_next; | |
71e330b5 DC |
364 | kmem_free(lv); |
365 | lv = next; | |
366 | } | |
367 | } | |
368 | ||
71e330b5 DC |
369 | /* |
370 | * Mark all items committed and clear busy extents. We free the log vector | |
371 | * chains in a separate pass so that we unpin the log items as quickly as | |
372 | * possible. | |
373 | */ | |
374 | static void | |
375 | xlog_cil_committed( | |
376 | void *args, | |
377 | int abort) | |
378 | { | |
379 | struct xfs_cil_ctx *ctx = args; | |
e84661aa | 380 | struct xfs_mount *mp = ctx->cil->xc_log->l_mp; |
71e330b5 | 381 | |
0e57f6a3 DC |
382 | xfs_trans_committed_bulk(ctx->cil->xc_log->l_ailp, ctx->lv_chain, |
383 | ctx->start_lsn, abort); | |
71e330b5 | 384 | |
4ecbfe63 DC |
385 | xfs_extent_busy_sort(&ctx->busy_extents); |
386 | xfs_extent_busy_clear(mp, &ctx->busy_extents, | |
e84661aa | 387 | (mp->m_flags & XFS_MOUNT_DISCARD) && !abort); |
71e330b5 | 388 | |
ac983517 DC |
389 | /* |
390 | * If we are aborting the commit, wake up anyone waiting on the | |
391 | * committing list. If we don't, then a shutdown we can leave processes | |
392 | * waiting in xlog_cil_force_lsn() waiting on a sequence commit that | |
393 | * will never happen because we aborted it. | |
394 | */ | |
4bb928cd | 395 | spin_lock(&ctx->cil->xc_push_lock); |
ac983517 DC |
396 | if (abort) |
397 | wake_up_all(&ctx->cil->xc_commit_wait); | |
71e330b5 | 398 | list_del(&ctx->committing); |
4bb928cd | 399 | spin_unlock(&ctx->cil->xc_push_lock); |
71e330b5 DC |
400 | |
401 | xlog_cil_free_logvec(ctx->lv_chain); | |
e84661aa CH |
402 | |
403 | if (!list_empty(&ctx->busy_extents)) { | |
404 | ASSERT(mp->m_flags & XFS_MOUNT_DISCARD); | |
405 | ||
406 | xfs_discard_extents(mp, &ctx->busy_extents); | |
4ecbfe63 | 407 | xfs_extent_busy_clear(mp, &ctx->busy_extents, false); |
e84661aa CH |
408 | } |
409 | ||
71e330b5 DC |
410 | kmem_free(ctx); |
411 | } | |
412 | ||
413 | /* | |
a44f13ed DC |
414 | * Push the Committed Item List to the log. If @push_seq flag is zero, then it |
415 | * is a background flush and so we can chose to ignore it. Otherwise, if the | |
416 | * current sequence is the same as @push_seq we need to do a flush. If | |
417 | * @push_seq is less than the current sequence, then it has already been | |
418 | * flushed and we don't need to do anything - the caller will wait for it to | |
419 | * complete if necessary. | |
420 | * | |
421 | * @push_seq is a value rather than a flag because that allows us to do an | |
422 | * unlocked check of the sequence number for a match. Hence we can allows log | |
423 | * forces to run racily and not issue pushes for the same sequence twice. If we | |
424 | * get a race between multiple pushes for the same sequence they will block on | |
425 | * the first one and then abort, hence avoiding needless pushes. | |
71e330b5 | 426 | */ |
a44f13ed | 427 | STATIC int |
71e330b5 | 428 | xlog_cil_push( |
f7bdf03a | 429 | struct xlog *log) |
71e330b5 DC |
430 | { |
431 | struct xfs_cil *cil = log->l_cilp; | |
432 | struct xfs_log_vec *lv; | |
433 | struct xfs_cil_ctx *ctx; | |
434 | struct xfs_cil_ctx *new_ctx; | |
435 | struct xlog_in_core *commit_iclog; | |
436 | struct xlog_ticket *tic; | |
71e330b5 | 437 | int num_iovecs; |
71e330b5 DC |
438 | int error = 0; |
439 | struct xfs_trans_header thdr; | |
440 | struct xfs_log_iovec lhdr; | |
441 | struct xfs_log_vec lvhdr = { NULL }; | |
442 | xfs_lsn_t commit_lsn; | |
4c2d542f | 443 | xfs_lsn_t push_seq; |
71e330b5 DC |
444 | |
445 | if (!cil) | |
446 | return 0; | |
447 | ||
71e330b5 DC |
448 | new_ctx = kmem_zalloc(sizeof(*new_ctx), KM_SLEEP|KM_NOFS); |
449 | new_ctx->ticket = xlog_cil_ticket_alloc(log); | |
450 | ||
4c2d542f | 451 | down_write(&cil->xc_ctx_lock); |
71e330b5 DC |
452 | ctx = cil->xc_ctx; |
453 | ||
4bb928cd | 454 | spin_lock(&cil->xc_push_lock); |
4c2d542f DC |
455 | push_seq = cil->xc_push_seq; |
456 | ASSERT(push_seq <= ctx->sequence); | |
71e330b5 | 457 | |
4c2d542f DC |
458 | /* |
459 | * Check if we've anything to push. If there is nothing, then we don't | |
460 | * move on to a new sequence number and so we have to be able to push | |
461 | * this sequence again later. | |
462 | */ | |
463 | if (list_empty(&cil->xc_cil)) { | |
464 | cil->xc_push_seq = 0; | |
4bb928cd | 465 | spin_unlock(&cil->xc_push_lock); |
a44f13ed | 466 | goto out_skip; |
4c2d542f | 467 | } |
4bb928cd | 468 | spin_unlock(&cil->xc_push_lock); |
4c2d542f | 469 | |
a44f13ed DC |
470 | |
471 | /* check for a previously pushed seqeunce */ | |
4c2d542f | 472 | if (push_seq < cil->xc_ctx->sequence) |
df806158 DC |
473 | goto out_skip; |
474 | ||
71e330b5 DC |
475 | /* |
476 | * pull all the log vectors off the items in the CIL, and | |
477 | * remove the items from the CIL. We don't need the CIL lock | |
478 | * here because it's only needed on the transaction commit | |
479 | * side which is currently locked out by the flush lock. | |
480 | */ | |
481 | lv = NULL; | |
71e330b5 | 482 | num_iovecs = 0; |
71e330b5 DC |
483 | while (!list_empty(&cil->xc_cil)) { |
484 | struct xfs_log_item *item; | |
71e330b5 DC |
485 | |
486 | item = list_first_entry(&cil->xc_cil, | |
487 | struct xfs_log_item, li_cil); | |
488 | list_del_init(&item->li_cil); | |
489 | if (!ctx->lv_chain) | |
490 | ctx->lv_chain = item->li_lv; | |
491 | else | |
492 | lv->lv_next = item->li_lv; | |
493 | lv = item->li_lv; | |
494 | item->li_lv = NULL; | |
71e330b5 | 495 | num_iovecs += lv->lv_niovecs; |
71e330b5 DC |
496 | } |
497 | ||
498 | /* | |
499 | * initialise the new context and attach it to the CIL. Then attach | |
500 | * the current context to the CIL committing lsit so it can be found | |
501 | * during log forces to extract the commit lsn of the sequence that | |
502 | * needs to be forced. | |
503 | */ | |
504 | INIT_LIST_HEAD(&new_ctx->committing); | |
505 | INIT_LIST_HEAD(&new_ctx->busy_extents); | |
506 | new_ctx->sequence = ctx->sequence + 1; | |
507 | new_ctx->cil = cil; | |
508 | cil->xc_ctx = new_ctx; | |
509 | ||
510 | /* | |
511 | * The switch is now done, so we can drop the context lock and move out | |
512 | * of a shared context. We can't just go straight to the commit record, | |
513 | * though - we need to synchronise with previous and future commits so | |
514 | * that the commit records are correctly ordered in the log to ensure | |
515 | * that we process items during log IO completion in the correct order. | |
516 | * | |
517 | * For example, if we get an EFI in one checkpoint and the EFD in the | |
518 | * next (e.g. due to log forces), we do not want the checkpoint with | |
519 | * the EFD to be committed before the checkpoint with the EFI. Hence | |
520 | * we must strictly order the commit records of the checkpoints so | |
521 | * that: a) the checkpoint callbacks are attached to the iclogs in the | |
522 | * correct order; and b) the checkpoints are replayed in correct order | |
523 | * in log recovery. | |
524 | * | |
525 | * Hence we need to add this context to the committing context list so | |
526 | * that higher sequences will wait for us to write out a commit record | |
527 | * before they do. | |
f876e446 DC |
528 | * |
529 | * xfs_log_force_lsn requires us to mirror the new sequence into the cil | |
530 | * structure atomically with the addition of this sequence to the | |
531 | * committing list. This also ensures that we can do unlocked checks | |
532 | * against the current sequence in log forces without risking | |
533 | * deferencing a freed context pointer. | |
71e330b5 | 534 | */ |
4bb928cd | 535 | spin_lock(&cil->xc_push_lock); |
f876e446 | 536 | cil->xc_current_sequence = new_ctx->sequence; |
71e330b5 | 537 | list_add(&ctx->committing, &cil->xc_committing); |
4bb928cd | 538 | spin_unlock(&cil->xc_push_lock); |
71e330b5 DC |
539 | up_write(&cil->xc_ctx_lock); |
540 | ||
541 | /* | |
542 | * Build a checkpoint transaction header and write it to the log to | |
543 | * begin the transaction. We need to account for the space used by the | |
544 | * transaction header here as it is not accounted for in xlog_write(). | |
545 | * | |
546 | * The LSN we need to pass to the log items on transaction commit is | |
547 | * the LSN reported by the first log vector write. If we use the commit | |
548 | * record lsn then we can move the tail beyond the grant write head. | |
549 | */ | |
550 | tic = ctx->ticket; | |
551 | thdr.th_magic = XFS_TRANS_HEADER_MAGIC; | |
552 | thdr.th_type = XFS_TRANS_CHECKPOINT; | |
553 | thdr.th_tid = tic->t_tid; | |
554 | thdr.th_num_items = num_iovecs; | |
4e0d5f92 | 555 | lhdr.i_addr = &thdr; |
71e330b5 DC |
556 | lhdr.i_len = sizeof(xfs_trans_header_t); |
557 | lhdr.i_type = XLOG_REG_TYPE_TRANSHDR; | |
558 | tic->t_curr_res -= lhdr.i_len + sizeof(xlog_op_header_t); | |
559 | ||
560 | lvhdr.lv_niovecs = 1; | |
561 | lvhdr.lv_iovecp = &lhdr; | |
562 | lvhdr.lv_next = ctx->lv_chain; | |
563 | ||
564 | error = xlog_write(log, &lvhdr, tic, &ctx->start_lsn, NULL, 0); | |
565 | if (error) | |
7db37c5e | 566 | goto out_abort_free_ticket; |
71e330b5 DC |
567 | |
568 | /* | |
569 | * now that we've written the checkpoint into the log, strictly | |
570 | * order the commit records so replay will get them in the right order. | |
571 | */ | |
572 | restart: | |
4bb928cd | 573 | spin_lock(&cil->xc_push_lock); |
71e330b5 | 574 | list_for_each_entry(new_ctx, &cil->xc_committing, committing) { |
ac983517 DC |
575 | /* |
576 | * Avoid getting stuck in this loop because we were woken by the | |
577 | * shutdown, but then went back to sleep once already in the | |
578 | * shutdown state. | |
579 | */ | |
580 | if (XLOG_FORCED_SHUTDOWN(log)) { | |
581 | spin_unlock(&cil->xc_push_lock); | |
582 | goto out_abort_free_ticket; | |
583 | } | |
584 | ||
71e330b5 DC |
585 | /* |
586 | * Higher sequences will wait for this one so skip them. | |
ac983517 | 587 | * Don't wait for our own sequence, either. |
71e330b5 DC |
588 | */ |
589 | if (new_ctx->sequence >= ctx->sequence) | |
590 | continue; | |
591 | if (!new_ctx->commit_lsn) { | |
592 | /* | |
593 | * It is still being pushed! Wait for the push to | |
594 | * complete, then start again from the beginning. | |
595 | */ | |
4bb928cd | 596 | xlog_wait(&cil->xc_commit_wait, &cil->xc_push_lock); |
71e330b5 DC |
597 | goto restart; |
598 | } | |
599 | } | |
4bb928cd | 600 | spin_unlock(&cil->xc_push_lock); |
71e330b5 | 601 | |
7db37c5e | 602 | /* xfs_log_done always frees the ticket on error. */ |
71e330b5 | 603 | commit_lsn = xfs_log_done(log->l_mp, tic, &commit_iclog, 0); |
7db37c5e | 604 | if (commit_lsn == -1) |
71e330b5 DC |
605 | goto out_abort; |
606 | ||
607 | /* attach all the transactions w/ busy extents to iclog */ | |
608 | ctx->log_cb.cb_func = xlog_cil_committed; | |
609 | ctx->log_cb.cb_arg = ctx; | |
610 | error = xfs_log_notify(log->l_mp, commit_iclog, &ctx->log_cb); | |
611 | if (error) | |
612 | goto out_abort; | |
613 | ||
614 | /* | |
615 | * now the checkpoint commit is complete and we've attached the | |
616 | * callbacks to the iclog we can assign the commit LSN to the context | |
617 | * and wake up anyone who is waiting for the commit to complete. | |
618 | */ | |
4bb928cd | 619 | spin_lock(&cil->xc_push_lock); |
71e330b5 | 620 | ctx->commit_lsn = commit_lsn; |
eb40a875 | 621 | wake_up_all(&cil->xc_commit_wait); |
4bb928cd | 622 | spin_unlock(&cil->xc_push_lock); |
71e330b5 DC |
623 | |
624 | /* release the hounds! */ | |
625 | return xfs_log_release_iclog(log->l_mp, commit_iclog); | |
626 | ||
627 | out_skip: | |
628 | up_write(&cil->xc_ctx_lock); | |
629 | xfs_log_ticket_put(new_ctx->ticket); | |
630 | kmem_free(new_ctx); | |
631 | return 0; | |
632 | ||
7db37c5e DC |
633 | out_abort_free_ticket: |
634 | xfs_log_ticket_put(tic); | |
71e330b5 DC |
635 | out_abort: |
636 | xlog_cil_committed(ctx, XFS_LI_ABORTED); | |
2451337d | 637 | return -EIO; |
71e330b5 DC |
638 | } |
639 | ||
4c2d542f DC |
640 | static void |
641 | xlog_cil_push_work( | |
642 | struct work_struct *work) | |
643 | { | |
644 | struct xfs_cil *cil = container_of(work, struct xfs_cil, | |
645 | xc_push_work); | |
646 | xlog_cil_push(cil->xc_log); | |
647 | } | |
648 | ||
649 | /* | |
650 | * We need to push CIL every so often so we don't cache more than we can fit in | |
651 | * the log. The limit really is that a checkpoint can't be more than half the | |
652 | * log (the current checkpoint is not allowed to overwrite the previous | |
653 | * checkpoint), but commit latency and memory usage limit this to a smaller | |
654 | * size. | |
655 | */ | |
656 | static void | |
657 | xlog_cil_push_background( | |
f7bdf03a | 658 | struct xlog *log) |
4c2d542f DC |
659 | { |
660 | struct xfs_cil *cil = log->l_cilp; | |
661 | ||
662 | /* | |
663 | * The cil won't be empty because we are called while holding the | |
664 | * context lock so whatever we added to the CIL will still be there | |
665 | */ | |
666 | ASSERT(!list_empty(&cil->xc_cil)); | |
667 | ||
668 | /* | |
669 | * don't do a background push if we haven't used up all the | |
670 | * space available yet. | |
671 | */ | |
672 | if (cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log)) | |
673 | return; | |
674 | ||
4bb928cd | 675 | spin_lock(&cil->xc_push_lock); |
4c2d542f DC |
676 | if (cil->xc_push_seq < cil->xc_current_sequence) { |
677 | cil->xc_push_seq = cil->xc_current_sequence; | |
678 | queue_work(log->l_mp->m_cil_workqueue, &cil->xc_push_work); | |
679 | } | |
4bb928cd | 680 | spin_unlock(&cil->xc_push_lock); |
4c2d542f DC |
681 | |
682 | } | |
683 | ||
f876e446 DC |
684 | /* |
685 | * xlog_cil_push_now() is used to trigger an immediate CIL push to the sequence | |
686 | * number that is passed. When it returns, the work will be queued for | |
687 | * @push_seq, but it won't be completed. The caller is expected to do any | |
688 | * waiting for push_seq to complete if it is required. | |
689 | */ | |
4c2d542f | 690 | static void |
f876e446 | 691 | xlog_cil_push_now( |
f7bdf03a | 692 | struct xlog *log, |
4c2d542f DC |
693 | xfs_lsn_t push_seq) |
694 | { | |
695 | struct xfs_cil *cil = log->l_cilp; | |
696 | ||
697 | if (!cil) | |
698 | return; | |
699 | ||
700 | ASSERT(push_seq && push_seq <= cil->xc_current_sequence); | |
701 | ||
702 | /* start on any pending background push to minimise wait time on it */ | |
703 | flush_work(&cil->xc_push_work); | |
704 | ||
705 | /* | |
706 | * If the CIL is empty or we've already pushed the sequence then | |
707 | * there's no work we need to do. | |
708 | */ | |
4bb928cd | 709 | spin_lock(&cil->xc_push_lock); |
4c2d542f | 710 | if (list_empty(&cil->xc_cil) || push_seq <= cil->xc_push_seq) { |
4bb928cd | 711 | spin_unlock(&cil->xc_push_lock); |
4c2d542f DC |
712 | return; |
713 | } | |
714 | ||
715 | cil->xc_push_seq = push_seq; | |
f876e446 | 716 | queue_work(log->l_mp->m_cil_workqueue, &cil->xc_push_work); |
4bb928cd | 717 | spin_unlock(&cil->xc_push_lock); |
4c2d542f DC |
718 | } |
719 | ||
2c6e24ce DC |
720 | bool |
721 | xlog_cil_empty( | |
722 | struct xlog *log) | |
723 | { | |
724 | struct xfs_cil *cil = log->l_cilp; | |
725 | bool empty = false; | |
726 | ||
727 | spin_lock(&cil->xc_push_lock); | |
728 | if (list_empty(&cil->xc_cil)) | |
729 | empty = true; | |
730 | spin_unlock(&cil->xc_push_lock); | |
731 | return empty; | |
732 | } | |
733 | ||
a44f13ed DC |
734 | /* |
735 | * Commit a transaction with the given vector to the Committed Item List. | |
736 | * | |
737 | * To do this, we need to format the item, pin it in memory if required and | |
738 | * account for the space used by the transaction. Once we have done that we | |
739 | * need to release the unused reservation for the transaction, attach the | |
740 | * transaction to the checkpoint context so we carry the busy extents through | |
741 | * to checkpoint completion, and then unlock all the items in the transaction. | |
742 | * | |
a44f13ed DC |
743 | * Called with the context lock already held in read mode to lock out |
744 | * background commit, returns without it held once background commits are | |
745 | * allowed again. | |
746 | */ | |
c6f97264 | 747 | void |
a44f13ed DC |
748 | xfs_log_commit_cil( |
749 | struct xfs_mount *mp, | |
750 | struct xfs_trans *tp, | |
a44f13ed DC |
751 | xfs_lsn_t *commit_lsn, |
752 | int flags) | |
753 | { | |
f7bdf03a | 754 | struct xlog *log = mp->m_log; |
991aaf65 | 755 | struct xfs_cil *cil = log->l_cilp; |
a44f13ed | 756 | int log_flags = 0; |
a44f13ed DC |
757 | |
758 | if (flags & XFS_TRANS_RELEASE_LOG_RES) | |
759 | log_flags = XFS_LOG_REL_PERM_RESERV; | |
760 | ||
f5baac35 | 761 | /* lock out background commit */ |
991aaf65 | 762 | down_read(&cil->xc_ctx_lock); |
f5baac35 | 763 | |
991aaf65 | 764 | xlog_cil_insert_items(log, tp); |
a44f13ed DC |
765 | |
766 | /* check we didn't blow the reservation */ | |
767 | if (tp->t_ticket->t_curr_res < 0) | |
991aaf65 | 768 | xlog_print_tic_res(mp, tp->t_ticket); |
a44f13ed | 769 | |
991aaf65 DC |
770 | tp->t_commit_lsn = cil->xc_ctx->sequence; |
771 | if (commit_lsn) | |
772 | *commit_lsn = tp->t_commit_lsn; | |
a44f13ed | 773 | |
a44f13ed DC |
774 | xfs_log_done(mp, tp->t_ticket, NULL, log_flags); |
775 | xfs_trans_unreserve_and_mod_sb(tp); | |
776 | ||
777 | /* | |
778 | * Once all the items of the transaction have been copied to the CIL, | |
779 | * the items can be unlocked and freed. | |
780 | * | |
781 | * This needs to be done before we drop the CIL context lock because we | |
782 | * have to update state in the log items and unlock them before they go | |
783 | * to disk. If we don't, then the CIL checkpoint can race with us and | |
784 | * we can run checkpoint completion before we've updated and unlocked | |
785 | * the log items. This affects (at least) processing of stale buffers, | |
786 | * inodes and EFIs. | |
787 | */ | |
991aaf65 | 788 | xfs_trans_free_items(tp, tp->t_commit_lsn, 0); |
a44f13ed | 789 | |
4c2d542f | 790 | xlog_cil_push_background(log); |
a44f13ed | 791 | |
991aaf65 | 792 | up_read(&cil->xc_ctx_lock); |
a44f13ed DC |
793 | } |
794 | ||
71e330b5 DC |
795 | /* |
796 | * Conditionally push the CIL based on the sequence passed in. | |
797 | * | |
798 | * We only need to push if we haven't already pushed the sequence | |
799 | * number given. Hence the only time we will trigger a push here is | |
800 | * if the push sequence is the same as the current context. | |
801 | * | |
802 | * We return the current commit lsn to allow the callers to determine if a | |
803 | * iclog flush is necessary following this call. | |
71e330b5 DC |
804 | */ |
805 | xfs_lsn_t | |
a44f13ed | 806 | xlog_cil_force_lsn( |
f7bdf03a | 807 | struct xlog *log, |
a44f13ed | 808 | xfs_lsn_t sequence) |
71e330b5 DC |
809 | { |
810 | struct xfs_cil *cil = log->l_cilp; | |
811 | struct xfs_cil_ctx *ctx; | |
812 | xfs_lsn_t commit_lsn = NULLCOMMITLSN; | |
813 | ||
a44f13ed DC |
814 | ASSERT(sequence <= cil->xc_current_sequence); |
815 | ||
816 | /* | |
817 | * check to see if we need to force out the current context. | |
818 | * xlog_cil_push() handles racing pushes for the same sequence, | |
819 | * so no need to deal with it here. | |
820 | */ | |
f876e446 DC |
821 | restart: |
822 | xlog_cil_push_now(log, sequence); | |
71e330b5 DC |
823 | |
824 | /* | |
825 | * See if we can find a previous sequence still committing. | |
71e330b5 DC |
826 | * We need to wait for all previous sequence commits to complete |
827 | * before allowing the force of push_seq to go ahead. Hence block | |
828 | * on commits for those as well. | |
829 | */ | |
4bb928cd | 830 | spin_lock(&cil->xc_push_lock); |
71e330b5 | 831 | list_for_each_entry(ctx, &cil->xc_committing, committing) { |
ac983517 DC |
832 | /* |
833 | * Avoid getting stuck in this loop because we were woken by the | |
834 | * shutdown, but then went back to sleep once already in the | |
835 | * shutdown state. | |
836 | */ | |
837 | if (XLOG_FORCED_SHUTDOWN(log)) | |
838 | goto out_shutdown; | |
a44f13ed | 839 | if (ctx->sequence > sequence) |
71e330b5 DC |
840 | continue; |
841 | if (!ctx->commit_lsn) { | |
842 | /* | |
843 | * It is still being pushed! Wait for the push to | |
844 | * complete, then start again from the beginning. | |
845 | */ | |
4bb928cd | 846 | xlog_wait(&cil->xc_commit_wait, &cil->xc_push_lock); |
71e330b5 DC |
847 | goto restart; |
848 | } | |
a44f13ed | 849 | if (ctx->sequence != sequence) |
71e330b5 DC |
850 | continue; |
851 | /* found it! */ | |
852 | commit_lsn = ctx->commit_lsn; | |
853 | } | |
f876e446 DC |
854 | |
855 | /* | |
856 | * The call to xlog_cil_push_now() executes the push in the background. | |
857 | * Hence by the time we have got here it our sequence may not have been | |
858 | * pushed yet. This is true if the current sequence still matches the | |
859 | * push sequence after the above wait loop and the CIL still contains | |
860 | * dirty objects. | |
861 | * | |
ac983517 DC |
862 | * When the push occurs, it will empty the CIL and atomically increment |
863 | * the currect sequence past the push sequence and move it into the | |
864 | * committing list. Of course, if the CIL is clean at the time of the | |
865 | * push, it won't have pushed the CIL at all, so in that case we should | |
866 | * try the push for this sequence again from the start just in case. | |
f876e446 | 867 | */ |
f876e446 DC |
868 | if (sequence == cil->xc_current_sequence && |
869 | !list_empty(&cil->xc_cil)) { | |
870 | spin_unlock(&cil->xc_push_lock); | |
871 | goto restart; | |
872 | } | |
873 | ||
4bb928cd | 874 | spin_unlock(&cil->xc_push_lock); |
71e330b5 | 875 | return commit_lsn; |
ac983517 DC |
876 | |
877 | /* | |
878 | * We detected a shutdown in progress. We need to trigger the log force | |
879 | * to pass through it's iclog state machine error handling, even though | |
880 | * we are already in a shutdown state. Hence we can't return | |
881 | * NULLCOMMITLSN here as that has special meaning to log forces (i.e. | |
882 | * LSN is already stable), so we return a zero LSN instead. | |
883 | */ | |
884 | out_shutdown: | |
885 | spin_unlock(&cil->xc_push_lock); | |
886 | return 0; | |
71e330b5 | 887 | } |
ccf7c23f DC |
888 | |
889 | /* | |
890 | * Check if the current log item was first committed in this sequence. | |
891 | * We can't rely on just the log item being in the CIL, we have to check | |
892 | * the recorded commit sequence number. | |
893 | * | |
894 | * Note: for this to be used in a non-racy manner, it has to be called with | |
895 | * CIL flushing locked out. As a result, it should only be used during the | |
896 | * transaction commit process when deciding what to format into the item. | |
897 | */ | |
898 | bool | |
899 | xfs_log_item_in_current_chkpt( | |
900 | struct xfs_log_item *lip) | |
901 | { | |
902 | struct xfs_cil_ctx *ctx; | |
903 | ||
ccf7c23f DC |
904 | if (list_empty(&lip->li_cil)) |
905 | return false; | |
906 | ||
907 | ctx = lip->li_mountp->m_log->l_cilp->xc_ctx; | |
908 | ||
909 | /* | |
910 | * li_seq is written on the first commit of a log item to record the | |
911 | * first checkpoint it is written to. Hence if it is different to the | |
912 | * current sequence, we're in a new checkpoint. | |
913 | */ | |
914 | if (XFS_LSN_CMP(lip->li_seq, ctx->sequence) != 0) | |
915 | return false; | |
916 | return true; | |
917 | } | |
4c2d542f DC |
918 | |
919 | /* | |
920 | * Perform initial CIL structure initialisation. | |
921 | */ | |
922 | int | |
923 | xlog_cil_init( | |
f7bdf03a | 924 | struct xlog *log) |
4c2d542f DC |
925 | { |
926 | struct xfs_cil *cil; | |
927 | struct xfs_cil_ctx *ctx; | |
928 | ||
929 | cil = kmem_zalloc(sizeof(*cil), KM_SLEEP|KM_MAYFAIL); | |
930 | if (!cil) | |
2451337d | 931 | return -ENOMEM; |
4c2d542f DC |
932 | |
933 | ctx = kmem_zalloc(sizeof(*ctx), KM_SLEEP|KM_MAYFAIL); | |
934 | if (!ctx) { | |
935 | kmem_free(cil); | |
2451337d | 936 | return -ENOMEM; |
4c2d542f DC |
937 | } |
938 | ||
939 | INIT_WORK(&cil->xc_push_work, xlog_cil_push_work); | |
940 | INIT_LIST_HEAD(&cil->xc_cil); | |
941 | INIT_LIST_HEAD(&cil->xc_committing); | |
942 | spin_lock_init(&cil->xc_cil_lock); | |
4bb928cd | 943 | spin_lock_init(&cil->xc_push_lock); |
4c2d542f DC |
944 | init_rwsem(&cil->xc_ctx_lock); |
945 | init_waitqueue_head(&cil->xc_commit_wait); | |
946 | ||
947 | INIT_LIST_HEAD(&ctx->committing); | |
948 | INIT_LIST_HEAD(&ctx->busy_extents); | |
949 | ctx->sequence = 1; | |
950 | ctx->cil = cil; | |
951 | cil->xc_ctx = ctx; | |
952 | cil->xc_current_sequence = ctx->sequence; | |
953 | ||
954 | cil->xc_log = log; | |
955 | log->l_cilp = cil; | |
956 | return 0; | |
957 | } | |
958 | ||
959 | void | |
960 | xlog_cil_destroy( | |
f7bdf03a | 961 | struct xlog *log) |
4c2d542f DC |
962 | { |
963 | if (log->l_cilp->xc_ctx) { | |
964 | if (log->l_cilp->xc_ctx->ticket) | |
965 | xfs_log_ticket_put(log->l_cilp->xc_ctx->ticket); | |
966 | kmem_free(log->l_cilp->xc_ctx); | |
967 | } | |
968 | ||
969 | ASSERT(list_empty(&log->l_cilp->xc_cil)); | |
970 | kmem_free(log->l_cilp); | |
971 | } | |
972 |