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