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0b61f8a4 | 1 | // SPDX-License-Identifier: GPL-2.0 |
71e330b5 DC |
2 | /* |
3 | * Copyright (c) 2010 Red Hat, Inc. All Rights Reserved. | |
71e330b5 DC |
4 | */ |
5 | ||
6 | #include "xfs.h" | |
7 | #include "xfs_fs.h" | |
4fb6e8ad | 8 | #include "xfs_format.h" |
239880ef | 9 | #include "xfs_log_format.h" |
70a9883c | 10 | #include "xfs_shared.h" |
239880ef | 11 | #include "xfs_trans_resv.h" |
71e330b5 | 12 | #include "xfs_mount.h" |
efc27b52 | 13 | #include "xfs_extent_busy.h" |
239880ef DC |
14 | #include "xfs_trans.h" |
15 | #include "xfs_trans_priv.h" | |
16 | #include "xfs_log.h" | |
17 | #include "xfs_log_priv.h" | |
4560e78f CH |
18 | #include "xfs_trace.h" |
19 | ||
20 | struct workqueue_struct *xfs_discard_wq; | |
71e330b5 | 21 | |
71e330b5 DC |
22 | /* |
23 | * Allocate a new ticket. Failing to get a new ticket makes it really hard to | |
24 | * recover, so we don't allow failure here. Also, we allocate in a context that | |
25 | * we don't want to be issuing transactions from, so we need to tell the | |
26 | * allocation code this as well. | |
27 | * | |
28 | * We don't reserve any space for the ticket - we are going to steal whatever | |
29 | * space we require from transactions as they commit. To ensure we reserve all | |
30 | * the space required, we need to set the current reservation of the ticket to | |
31 | * zero so that we know to steal the initial transaction overhead from the | |
32 | * first transaction commit. | |
33 | */ | |
34 | static struct xlog_ticket * | |
35 | xlog_cil_ticket_alloc( | |
f7bdf03a | 36 | struct xlog *log) |
71e330b5 DC |
37 | { |
38 | struct xlog_ticket *tic; | |
39 | ||
c7610dce | 40 | tic = xlog_ticket_alloc(log, 0, 1, 0); |
71e330b5 DC |
41 | |
42 | /* | |
43 | * set the current reservation to zero so we know to steal the basic | |
44 | * transaction overhead reservation from the first transaction commit. | |
45 | */ | |
46 | tic->t_curr_res = 0; | |
31151cc3 | 47 | tic->t_iclog_hdrs = 0; |
71e330b5 DC |
48 | return tic; |
49 | } | |
50 | ||
31151cc3 DC |
51 | static inline void |
52 | xlog_cil_set_iclog_hdr_count(struct xfs_cil *cil) | |
53 | { | |
54 | struct xlog *log = cil->xc_log; | |
55 | ||
56 | atomic_set(&cil->xc_iclog_hdrs, | |
57 | (XLOG_CIL_BLOCKING_SPACE_LIMIT(log) / | |
58 | (log->l_iclog_size - log->l_iclog_hsize))); | |
59 | } | |
60 | ||
22b1afc5 DC |
61 | /* |
62 | * Check if the current log item was first committed in this sequence. | |
63 | * We can't rely on just the log item being in the CIL, we have to check | |
64 | * the recorded commit sequence number. | |
65 | * | |
66 | * Note: for this to be used in a non-racy manner, it has to be called with | |
67 | * CIL flushing locked out. As a result, it should only be used during the | |
68 | * transaction commit process when deciding what to format into the item. | |
69 | */ | |
70 | static bool | |
71 | xlog_item_in_current_chkpt( | |
72 | struct xfs_cil *cil, | |
73 | struct xfs_log_item *lip) | |
74 | { | |
88591e7f | 75 | if (test_bit(XLOG_CIL_EMPTY, &cil->xc_flags)) |
22b1afc5 DC |
76 | return false; |
77 | ||
78 | /* | |
79 | * li_seq is written on the first commit of a log item to record the | |
80 | * first checkpoint it is written to. Hence if it is different to the | |
81 | * current sequence, we're in a new checkpoint. | |
82 | */ | |
83 | return lip->li_seq == READ_ONCE(cil->xc_current_sequence); | |
84 | } | |
85 | ||
86 | bool | |
87 | xfs_log_item_in_current_chkpt( | |
88 | struct xfs_log_item *lip) | |
89 | { | |
90 | return xlog_item_in_current_chkpt(lip->li_log->l_cilp, lip); | |
91 | } | |
92 | ||
39823d0f DC |
93 | /* |
94 | * Unavoidable forward declaration - xlog_cil_push_work() calls | |
95 | * xlog_cil_ctx_alloc() itself. | |
96 | */ | |
97 | static void xlog_cil_push_work(struct work_struct *work); | |
98 | ||
99 | static struct xfs_cil_ctx * | |
100 | xlog_cil_ctx_alloc(void) | |
101 | { | |
102 | struct xfs_cil_ctx *ctx; | |
103 | ||
104 | ctx = kmem_zalloc(sizeof(*ctx), KM_NOFS); | |
105 | INIT_LIST_HEAD(&ctx->committing); | |
106 | INIT_LIST_HEAD(&ctx->busy_extents); | |
107 | INIT_WORK(&ctx->push_work, xlog_cil_push_work); | |
108 | return ctx; | |
109 | } | |
110 | ||
7c8ade21 DC |
111 | /* |
112 | * Aggregate the CIL per cpu structures into global counts, lists, etc and | |
113 | * clear the percpu state ready for the next context to use. This is called | |
114 | * from the push code with the context lock held exclusively, hence nothing else | |
115 | * will be accessing or modifying the per-cpu counters. | |
116 | */ | |
117 | static void | |
118 | xlog_cil_push_pcp_aggregate( | |
119 | struct xfs_cil *cil, | |
120 | struct xfs_cil_ctx *ctx) | |
121 | { | |
122 | struct xlog_cil_pcp *cilpcp; | |
123 | int cpu; | |
124 | ||
125 | for_each_online_cpu(cpu) { | |
126 | cilpcp = per_cpu_ptr(cil->xc_pcp, cpu); | |
127 | ||
1dd2a2c1 DC |
128 | ctx->ticket->t_curr_res += cilpcp->space_reserved; |
129 | cilpcp->space_reserved = 0; | |
130 | ||
df7a4a21 DC |
131 | if (!list_empty(&cilpcp->busy_extents)) { |
132 | list_splice_init(&cilpcp->busy_extents, | |
133 | &ctx->busy_extents); | |
134 | } | |
135 | ||
7c8ade21 DC |
136 | /* |
137 | * We're in the middle of switching cil contexts. Reset the | |
138 | * counter we use to detect when the current context is nearing | |
139 | * full. | |
140 | */ | |
141 | cilpcp->space_used = 0; | |
142 | } | |
143 | } | |
144 | ||
145 | /* | |
146 | * Aggregate the CIL per-cpu space used counters into the global atomic value. | |
147 | * This is called when the per-cpu counter aggregation will first pass the soft | |
148 | * limit threshold so we can switch to atomic counter aggregation for accurate | |
149 | * detection of hard limit traversal. | |
150 | */ | |
151 | static void | |
152 | xlog_cil_insert_pcp_aggregate( | |
153 | struct xfs_cil *cil, | |
154 | struct xfs_cil_ctx *ctx) | |
155 | { | |
156 | struct xlog_cil_pcp *cilpcp; | |
157 | int cpu; | |
158 | int count = 0; | |
159 | ||
160 | /* Trigger atomic updates then aggregate only for the first caller */ | |
161 | if (!test_and_clear_bit(XLOG_CIL_PCP_SPACE, &cil->xc_flags)) | |
162 | return; | |
163 | ||
164 | for_each_online_cpu(cpu) { | |
165 | int old, prev; | |
166 | ||
167 | cilpcp = per_cpu_ptr(cil->xc_pcp, cpu); | |
168 | do { | |
169 | old = cilpcp->space_used; | |
170 | prev = cmpxchg(&cilpcp->space_used, old, 0); | |
171 | } while (old != prev); | |
172 | count += old; | |
173 | } | |
174 | atomic_add(count, &ctx->space_used); | |
175 | } | |
176 | ||
39823d0f DC |
177 | static void |
178 | xlog_cil_ctx_switch( | |
179 | struct xfs_cil *cil, | |
180 | struct xfs_cil_ctx *ctx) | |
181 | { | |
31151cc3 | 182 | xlog_cil_set_iclog_hdr_count(cil); |
88591e7f | 183 | set_bit(XLOG_CIL_EMPTY, &cil->xc_flags); |
7c8ade21 | 184 | set_bit(XLOG_CIL_PCP_SPACE, &cil->xc_flags); |
39823d0f DC |
185 | ctx->sequence = ++cil->xc_current_sequence; |
186 | ctx->cil = cil; | |
187 | cil->xc_ctx = ctx; | |
188 | } | |
189 | ||
71e330b5 DC |
190 | /* |
191 | * After the first stage of log recovery is done, we know where the head and | |
192 | * tail of the log are. We need this log initialisation done before we can | |
193 | * initialise the first CIL checkpoint context. | |
194 | * | |
195 | * Here we allocate a log ticket to track space usage during a CIL push. This | |
196 | * ticket is passed to xlog_write() directly so that we don't slowly leak log | |
197 | * space by failing to account for space used by log headers and additional | |
198 | * region headers for split regions. | |
199 | */ | |
200 | void | |
201 | xlog_cil_init_post_recovery( | |
f7bdf03a | 202 | struct xlog *log) |
71e330b5 | 203 | { |
71e330b5 DC |
204 | log->l_cilp->xc_ctx->ticket = xlog_cil_ticket_alloc(log); |
205 | log->l_cilp->xc_ctx->sequence = 1; | |
31151cc3 | 206 | xlog_cil_set_iclog_hdr_count(log->l_cilp); |
71e330b5 DC |
207 | } |
208 | ||
b1c5ebb2 DC |
209 | static inline int |
210 | xlog_cil_iovec_space( | |
211 | uint niovecs) | |
212 | { | |
213 | return round_up((sizeof(struct xfs_log_vec) + | |
214 | niovecs * sizeof(struct xfs_log_iovec)), | |
215 | sizeof(uint64_t)); | |
216 | } | |
217 | ||
218 | /* | |
219 | * Allocate or pin log vector buffers for CIL insertion. | |
220 | * | |
221 | * The CIL currently uses disposable buffers for copying a snapshot of the | |
222 | * modified items into the log during a push. The biggest problem with this is | |
223 | * the requirement to allocate the disposable buffer during the commit if: | |
224 | * a) does not exist; or | |
225 | * b) it is too small | |
226 | * | |
227 | * If we do this allocation within xlog_cil_insert_format_items(), it is done | |
228 | * under the xc_ctx_lock, which means that a CIL push cannot occur during | |
229 | * the memory allocation. This means that we have a potential deadlock situation | |
230 | * under low memory conditions when we have lots of dirty metadata pinned in | |
231 | * the CIL and we need a CIL commit to occur to free memory. | |
232 | * | |
233 | * To avoid this, we need to move the memory allocation outside the | |
234 | * xc_ctx_lock, but because the log vector buffers are disposable, that opens | |
235 | * up a TOCTOU race condition w.r.t. the CIL committing and removing the log | |
236 | * vector buffers between the check and the formatting of the item into the | |
237 | * log vector buffer within the xc_ctx_lock. | |
238 | * | |
239 | * Because the log vector buffer needs to be unchanged during the CIL push | |
240 | * process, we cannot share the buffer between the transaction commit (which | |
241 | * modifies the buffer) and the CIL push context that is writing the changes | |
242 | * into the log. This means skipping preallocation of buffer space is | |
243 | * unreliable, but we most definitely do not want to be allocating and freeing | |
244 | * buffers unnecessarily during commits when overwrites can be done safely. | |
245 | * | |
246 | * The simplest solution to this problem is to allocate a shadow buffer when a | |
247 | * log item is committed for the second time, and then to only use this buffer | |
248 | * if necessary. The buffer can remain attached to the log item until such time | |
249 | * it is needed, and this is the buffer that is reallocated to match the size of | |
250 | * the incoming modification. Then during the formatting of the item we can swap | |
251 | * the active buffer with the new one if we can't reuse the existing buffer. We | |
252 | * don't free the old buffer as it may be reused on the next modification if | |
253 | * it's size is right, otherwise we'll free and reallocate it at that point. | |
254 | * | |
255 | * This function builds a vector for the changes in each log item in the | |
256 | * transaction. It then works out the length of the buffer needed for each log | |
257 | * item, allocates them and attaches the vector to the log item in preparation | |
258 | * for the formatting step which occurs under the xc_ctx_lock. | |
259 | * | |
260 | * While this means the memory footprint goes up, it avoids the repeated | |
261 | * alloc/free pattern that repeated modifications of an item would otherwise | |
262 | * cause, and hence minimises the CPU overhead of such behaviour. | |
263 | */ | |
264 | static void | |
265 | xlog_cil_alloc_shadow_bufs( | |
266 | struct xlog *log, | |
267 | struct xfs_trans *tp) | |
268 | { | |
e6631f85 | 269 | struct xfs_log_item *lip; |
b1c5ebb2 | 270 | |
e6631f85 | 271 | list_for_each_entry(lip, &tp->t_items, li_trans) { |
b1c5ebb2 DC |
272 | struct xfs_log_vec *lv; |
273 | int niovecs = 0; | |
274 | int nbytes = 0; | |
275 | int buf_size; | |
276 | bool ordered = false; | |
277 | ||
278 | /* Skip items which aren't dirty in this transaction. */ | |
e6631f85 | 279 | if (!test_bit(XFS_LI_DIRTY, &lip->li_flags)) |
b1c5ebb2 DC |
280 | continue; |
281 | ||
282 | /* get number of vecs and size of data to be stored */ | |
283 | lip->li_ops->iop_size(lip, &niovecs, &nbytes); | |
284 | ||
285 | /* | |
286 | * Ordered items need to be tracked but we do not wish to write | |
287 | * them. We need a logvec to track the object, but we do not | |
288 | * need an iovec or buffer to be allocated for copying data. | |
289 | */ | |
290 | if (niovecs == XFS_LOG_VEC_ORDERED) { | |
291 | ordered = true; | |
292 | niovecs = 0; | |
293 | nbytes = 0; | |
294 | } | |
295 | ||
296 | /* | |
8d547cf9 DC |
297 | * We 64-bit align the length of each iovec so that the start of |
298 | * the next one is naturally aligned. We'll need to account for | |
299 | * that slack space here. | |
300 | * | |
301 | * We also add the xlog_op_header to each region when | |
302 | * formatting, but that's not accounted to the size of the item | |
303 | * at this point. Hence we'll need an addition number of bytes | |
304 | * for each vector to hold an opheader. | |
305 | * | |
306 | * Then round nbytes up to 64-bit alignment so that the initial | |
307 | * buffer alignment is easy to calculate and verify. | |
b1c5ebb2 | 308 | */ |
8d547cf9 DC |
309 | nbytes += niovecs * |
310 | (sizeof(uint64_t) + sizeof(struct xlog_op_header)); | |
b1c5ebb2 DC |
311 | nbytes = round_up(nbytes, sizeof(uint64_t)); |
312 | ||
313 | /* | |
314 | * The data buffer needs to start 64-bit aligned, so round up | |
315 | * that space to ensure we can align it appropriately and not | |
316 | * overrun the buffer. | |
317 | */ | |
318 | buf_size = nbytes + xlog_cil_iovec_space(niovecs); | |
319 | ||
320 | /* | |
321 | * if we have no shadow buffer, or it is too small, we need to | |
322 | * reallocate it. | |
323 | */ | |
324 | if (!lip->li_lv_shadow || | |
325 | buf_size > lip->li_lv_shadow->lv_size) { | |
b1c5ebb2 DC |
326 | /* |
327 | * We free and allocate here as a realloc would copy | |
8dc9384b | 328 | * unnecessary data. We don't use kvzalloc() for the |
b1c5ebb2 DC |
329 | * same reason - we don't need to zero the data area in |
330 | * the buffer, only the log vector header and the iovec | |
331 | * storage. | |
332 | */ | |
333 | kmem_free(lip->li_lv_shadow); | |
45ff8b47 | 334 | lv = xlog_kvmalloc(buf_size); |
b1c5ebb2 | 335 | |
b1c5ebb2 DC |
336 | memset(lv, 0, xlog_cil_iovec_space(niovecs)); |
337 | ||
338 | lv->lv_item = lip; | |
339 | lv->lv_size = buf_size; | |
340 | if (ordered) | |
341 | lv->lv_buf_len = XFS_LOG_VEC_ORDERED; | |
342 | else | |
343 | lv->lv_iovecp = (struct xfs_log_iovec *)&lv[1]; | |
344 | lip->li_lv_shadow = lv; | |
345 | } else { | |
346 | /* same or smaller, optimise common overwrite case */ | |
347 | lv = lip->li_lv_shadow; | |
348 | if (ordered) | |
349 | lv->lv_buf_len = XFS_LOG_VEC_ORDERED; | |
350 | else | |
351 | lv->lv_buf_len = 0; | |
352 | lv->lv_bytes = 0; | |
353 | lv->lv_next = NULL; | |
354 | } | |
355 | ||
356 | /* Ensure the lv is set up according to ->iop_size */ | |
357 | lv->lv_niovecs = niovecs; | |
358 | ||
359 | /* The allocated data region lies beyond the iovec region */ | |
360 | lv->lv_buf = (char *)lv + xlog_cil_iovec_space(niovecs); | |
361 | } | |
362 | ||
363 | } | |
364 | ||
991aaf65 DC |
365 | /* |
366 | * Prepare the log item for insertion into the CIL. Calculate the difference in | |
593e3439 | 367 | * log space it will consume, and if it is a new item pin it as well. |
991aaf65 DC |
368 | */ |
369 | STATIC void | |
370 | xfs_cil_prepare_item( | |
371 | struct xlog *log, | |
372 | struct xfs_log_vec *lv, | |
373 | struct xfs_log_vec *old_lv, | |
593e3439 | 374 | int *diff_len) |
991aaf65 DC |
375 | { |
376 | /* Account for the new LV being passed in */ | |
593e3439 | 377 | if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED) |
110dc24a | 378 | *diff_len += lv->lv_bytes; |
991aaf65 DC |
379 | |
380 | /* | |
381 | * If there is no old LV, this is the first time we've seen the item in | |
382 | * this CIL context and so we need to pin it. If we are replacing the | |
b1c5ebb2 DC |
383 | * old_lv, then remove the space it accounts for and make it the shadow |
384 | * buffer for later freeing. In both cases we are now switching to the | |
b63da6c8 | 385 | * shadow buffer, so update the pointer to it appropriately. |
991aaf65 | 386 | */ |
b1c5ebb2 | 387 | if (!old_lv) { |
e8b78db7 CH |
388 | if (lv->lv_item->li_ops->iop_pin) |
389 | lv->lv_item->li_ops->iop_pin(lv->lv_item); | |
b1c5ebb2 DC |
390 | lv->lv_item->li_lv_shadow = NULL; |
391 | } else if (old_lv != lv) { | |
991aaf65 DC |
392 | ASSERT(lv->lv_buf_len != XFS_LOG_VEC_ORDERED); |
393 | ||
110dc24a | 394 | *diff_len -= old_lv->lv_bytes; |
b1c5ebb2 | 395 | lv->lv_item->li_lv_shadow = old_lv; |
991aaf65 DC |
396 | } |
397 | ||
398 | /* attach new log vector to log item */ | |
399 | lv->lv_item->li_lv = lv; | |
400 | ||
401 | /* | |
402 | * If this is the first time the item is being committed to the | |
403 | * CIL, store the sequence number on the log item so we can | |
404 | * tell in future commits whether this is the first checkpoint | |
405 | * the item is being committed into. | |
406 | */ | |
407 | if (!lv->lv_item->li_seq) | |
408 | lv->lv_item->li_seq = log->l_cilp->xc_ctx->sequence; | |
409 | } | |
410 | ||
71e330b5 DC |
411 | /* |
412 | * Format log item into a flat buffers | |
413 | * | |
414 | * For delayed logging, we need to hold a formatted buffer containing all the | |
415 | * changes on the log item. This enables us to relog the item in memory and | |
416 | * write it out asynchronously without needing to relock the object that was | |
417 | * modified at the time it gets written into the iclog. | |
418 | * | |
b1c5ebb2 DC |
419 | * This function takes the prepared log vectors attached to each log item, and |
420 | * formats the changes into the log vector buffer. The buffer it uses is | |
421 | * dependent on the current state of the vector in the CIL - the shadow lv is | |
422 | * guaranteed to be large enough for the current modification, but we will only | |
423 | * use that if we can't reuse the existing lv. If we can't reuse the existing | |
424 | * lv, then simple swap it out for the shadow lv. We don't free it - that is | |
425 | * done lazily either by th enext modification or the freeing of the log item. | |
71e330b5 DC |
426 | * |
427 | * We don't set up region headers during this process; we simply copy the | |
428 | * regions into the flat buffer. We can do this because we still have to do a | |
429 | * formatting step to write the regions into the iclog buffer. Writing the | |
430 | * ophdrs during the iclog write means that we can support splitting large | |
431 | * regions across iclog boundares without needing a change in the format of the | |
432 | * item/region encapsulation. | |
433 | * | |
434 | * Hence what we need to do now is change the rewrite the vector array to point | |
435 | * to the copied region inside the buffer we just allocated. This allows us to | |
436 | * format the regions into the iclog as though they are being formatted | |
437 | * directly out of the objects themselves. | |
438 | */ | |
991aaf65 DC |
439 | static void |
440 | xlog_cil_insert_format_items( | |
441 | struct xlog *log, | |
442 | struct xfs_trans *tp, | |
593e3439 | 443 | int *diff_len) |
71e330b5 | 444 | { |
e6631f85 | 445 | struct xfs_log_item *lip; |
71e330b5 | 446 | |
0244b960 CH |
447 | /* Bail out if we didn't find a log item. */ |
448 | if (list_empty(&tp->t_items)) { | |
449 | ASSERT(0); | |
991aaf65 | 450 | return; |
0244b960 CH |
451 | } |
452 | ||
e6631f85 | 453 | list_for_each_entry(lip, &tp->t_items, li_trans) { |
7492c5b4 | 454 | struct xfs_log_vec *lv; |
b1c5ebb2 DC |
455 | struct xfs_log_vec *old_lv = NULL; |
456 | struct xfs_log_vec *shadow; | |
fd63875c | 457 | bool ordered = false; |
71e330b5 | 458 | |
0244b960 | 459 | /* Skip items which aren't dirty in this transaction. */ |
e6631f85 | 460 | if (!test_bit(XFS_LI_DIRTY, &lip->li_flags)) |
0244b960 CH |
461 | continue; |
462 | ||
fd63875c | 463 | /* |
b1c5ebb2 DC |
464 | * The formatting size information is already attached to |
465 | * the shadow lv on the log item. | |
fd63875c | 466 | */ |
b1c5ebb2 DC |
467 | shadow = lip->li_lv_shadow; |
468 | if (shadow->lv_buf_len == XFS_LOG_VEC_ORDERED) | |
fd63875c | 469 | ordered = true; |
fd63875c | 470 | |
b1c5ebb2 DC |
471 | /* Skip items that do not have any vectors for writing */ |
472 | if (!shadow->lv_niovecs && !ordered) | |
473 | continue; | |
0244b960 | 474 | |
f5baac35 | 475 | /* compare to existing item size */ |
b1c5ebb2 DC |
476 | old_lv = lip->li_lv; |
477 | if (lip->li_lv && shadow->lv_size <= lip->li_lv->lv_size) { | |
f5baac35 DC |
478 | /* same or smaller, optimise common overwrite case */ |
479 | lv = lip->li_lv; | |
480 | lv->lv_next = NULL; | |
481 | ||
482 | if (ordered) | |
483 | goto insert; | |
484 | ||
991aaf65 DC |
485 | /* |
486 | * set the item up as though it is a new insertion so | |
487 | * that the space reservation accounting is correct. | |
488 | */ | |
110dc24a | 489 | *diff_len -= lv->lv_bytes; |
b1c5ebb2 DC |
490 | |
491 | /* Ensure the lv is set up according to ->iop_size */ | |
492 | lv->lv_niovecs = shadow->lv_niovecs; | |
493 | ||
494 | /* reset the lv buffer information for new formatting */ | |
495 | lv->lv_buf_len = 0; | |
496 | lv->lv_bytes = 0; | |
497 | lv->lv_buf = (char *)lv + | |
498 | xlog_cil_iovec_space(lv->lv_niovecs); | |
9597df6b | 499 | } else { |
b1c5ebb2 DC |
500 | /* switch to shadow buffer! */ |
501 | lv = shadow; | |
9597df6b | 502 | lv->lv_item = lip; |
9597df6b CH |
503 | if (ordered) { |
504 | /* track as an ordered logvec */ | |
505 | ASSERT(lip->li_lv == NULL); | |
9597df6b CH |
506 | goto insert; |
507 | } | |
f5baac35 DC |
508 | } |
509 | ||
3895e51f | 510 | ASSERT(IS_ALIGNED((unsigned long)lv->lv_buf, sizeof(uint64_t))); |
bde7cff6 | 511 | lip->li_ops->iop_format(lip, lv); |
7492c5b4 | 512 | insert: |
593e3439 | 513 | xfs_cil_prepare_item(log, lv, old_lv, diff_len); |
3b93c7aa | 514 | } |
d1583a38 DC |
515 | } |
516 | ||
7c8ade21 DC |
517 | /* |
518 | * The use of lockless waitqueue_active() requires that the caller has | |
519 | * serialised itself against the wakeup call in xlog_cil_push_work(). That | |
520 | * can be done by either holding the push lock or the context lock. | |
521 | */ | |
522 | static inline bool | |
523 | xlog_cil_over_hard_limit( | |
524 | struct xlog *log, | |
525 | int32_t space_used) | |
526 | { | |
527 | if (waitqueue_active(&log->l_cilp->xc_push_wait)) | |
528 | return true; | |
529 | if (space_used >= XLOG_CIL_BLOCKING_SPACE_LIMIT(log)) | |
530 | return true; | |
531 | return false; | |
532 | } | |
533 | ||
d1583a38 DC |
534 | /* |
535 | * Insert the log items into the CIL and calculate the difference in space | |
536 | * consumed by the item. Add the space to the checkpoint ticket and calculate | |
537 | * if the change requires additional log metadata. If it does, take that space | |
42b2aa86 | 538 | * as well. Remove the amount of space we added to the checkpoint ticket from |
d1583a38 DC |
539 | * the current transaction ticket so that the accounting works out correctly. |
540 | */ | |
3b93c7aa DC |
541 | static void |
542 | xlog_cil_insert_items( | |
f7bdf03a | 543 | struct xlog *log, |
0d227466 DC |
544 | struct xfs_trans *tp, |
545 | uint32_t released_space) | |
3b93c7aa | 546 | { |
d1583a38 DC |
547 | struct xfs_cil *cil = log->l_cilp; |
548 | struct xfs_cil_ctx *ctx = cil->xc_ctx; | |
e6631f85 | 549 | struct xfs_log_item *lip; |
d1583a38 | 550 | int len = 0; |
e2f23426 | 551 | int iovhdr_res = 0, split_res = 0, ctx_res = 0; |
7c8ade21 DC |
552 | int space_used; |
553 | struct xlog_cil_pcp *cilpcp; | |
3b93c7aa | 554 | |
991aaf65 | 555 | ASSERT(tp); |
d1583a38 DC |
556 | |
557 | /* | |
d1583a38 DC |
558 | * We can do this safely because the context can't checkpoint until we |
559 | * are done so it doesn't matter exactly how we update the CIL. | |
560 | */ | |
593e3439 | 561 | xlog_cil_insert_format_items(log, tp, &len); |
991aaf65 | 562 | |
7c8ade21 DC |
563 | /* |
564 | * Subtract the space released by intent cancelation from the space we | |
565 | * consumed so that we remove it from the CIL space and add it back to | |
566 | * the current transaction reservation context. | |
567 | */ | |
568 | len -= released_space; | |
569 | ||
570 | /* | |
571 | * Grab the per-cpu pointer for the CIL before we start any accounting. | |
572 | * That ensures that we are running with pre-emption disabled and so we | |
573 | * can't be scheduled away between split sample/update operations that | |
574 | * are done without outside locking to serialise them. | |
575 | */ | |
576 | cilpcp = get_cpu_ptr(cil->xc_pcp); | |
577 | ||
d1583a38 | 578 | /* |
88591e7f DC |
579 | * We need to take the CIL checkpoint unit reservation on the first |
580 | * commit into the CIL. Test the XLOG_CIL_EMPTY bit first so we don't | |
12380d23 DC |
581 | * unnecessarily do an atomic op in the fast path here. We don't need to |
582 | * hold the xc_cil_lock here to clear the XLOG_CIL_EMPTY bit as we are | |
583 | * under the xc_ctx_lock here and that needs to be held exclusively to | |
584 | * reset the XLOG_CIL_EMPTY bit. | |
d1583a38 | 585 | */ |
88591e7f | 586 | if (test_bit(XLOG_CIL_EMPTY, &cil->xc_flags) && |
12380d23 | 587 | test_and_clear_bit(XLOG_CIL_EMPTY, &cil->xc_flags)) |
e2f23426 | 588 | ctx_res = ctx->ticket->t_unit_res; |
12380d23 | 589 | |
31151cc3 DC |
590 | /* |
591 | * Check if we need to steal iclog headers. atomic_read() is not a | |
592 | * locked atomic operation, so we can check the value before we do any | |
593 | * real atomic ops in the fast path. If we've already taken the CIL unit | |
594 | * reservation from this commit, we've already got one iclog header | |
595 | * space reserved so we have to account for that otherwise we risk | |
596 | * overrunning the reservation on this ticket. | |
597 | * | |
598 | * If the CIL is already at the hard limit, we might need more header | |
599 | * space that originally reserved. So steal more header space from every | |
600 | * commit that occurs once we are over the hard limit to ensure the CIL | |
601 | * push won't run out of reservation space. | |
602 | * | |
603 | * This can steal more than we need, but that's OK. | |
7c8ade21 DC |
604 | * |
605 | * The cil->xc_ctx_lock provides the serialisation necessary for safely | |
606 | * calling xlog_cil_over_hard_limit() in this context. | |
31151cc3 | 607 | */ |
7c8ade21 | 608 | space_used = atomic_read(&ctx->space_used) + cilpcp->space_used + len; |
31151cc3 | 609 | if (atomic_read(&cil->xc_iclog_hdrs) > 0 || |
7c8ade21 DC |
610 | xlog_cil_over_hard_limit(log, space_used)) { |
611 | split_res = log->l_iclog_hsize + | |
31151cc3 DC |
612 | sizeof(struct xlog_op_header); |
613 | if (ctx_res) | |
614 | ctx_res += split_res * (tp->t_ticket->t_iclog_hdrs - 1); | |
615 | else | |
616 | ctx_res = split_res * tp->t_ticket->t_iclog_hdrs; | |
617 | atomic_sub(tp->t_ticket->t_iclog_hdrs, &cil->xc_iclog_hdrs); | |
d1583a38 | 618 | } |
1dd2a2c1 | 619 | cilpcp->space_reserved += ctx_res; |
31151cc3 | 620 | |
d4ca1d55 | 621 | /* |
7c8ade21 DC |
622 | * Accurately account when over the soft limit, otherwise fold the |
623 | * percpu count into the global count if over the per-cpu threshold. | |
d4ca1d55 | 624 | */ |
7c8ade21 DC |
625 | if (!test_bit(XLOG_CIL_PCP_SPACE, &cil->xc_flags)) { |
626 | atomic_add(len, &ctx->space_used); | |
627 | } else if (cilpcp->space_used + len > | |
628 | (XLOG_CIL_SPACE_LIMIT(log) / num_online_cpus())) { | |
629 | space_used = atomic_add_return(cilpcp->space_used + len, | |
630 | &ctx->space_used); | |
631 | cilpcp->space_used = 0; | |
632 | ||
633 | /* | |
634 | * If we just transitioned over the soft limit, we need to | |
635 | * transition to the global atomic counter. | |
636 | */ | |
637 | if (space_used >= XLOG_CIL_SPACE_LIMIT(log)) | |
638 | xlog_cil_insert_pcp_aggregate(cil, ctx); | |
639 | } else { | |
640 | cilpcp->space_used += len; | |
d4ca1d55 | 641 | } |
df7a4a21 DC |
642 | /* attach the transaction to the CIL if it has any busy extents */ |
643 | if (!list_empty(&tp->t_busy)) | |
644 | list_splice_init(&tp->t_busy, &cilpcp->busy_extents); | |
7c8ade21 DC |
645 | put_cpu_ptr(cilpcp); |
646 | ||
e2f23426 BF |
647 | /* |
648 | * Now (re-)position everything modified at the tail of the CIL. | |
649 | * We do this here so we only need to take the CIL lock once during | |
650 | * the transaction commit. | |
651 | */ | |
1dd2a2c1 | 652 | spin_lock(&cil->xc_cil_lock); |
e6631f85 | 653 | list_for_each_entry(lip, &tp->t_items, li_trans) { |
e2f23426 | 654 | /* Skip items which aren't dirty in this transaction. */ |
e6631f85 | 655 | if (!test_bit(XFS_LI_DIRTY, &lip->li_flags)) |
e2f23426 BF |
656 | continue; |
657 | ||
658 | /* | |
659 | * Only move the item if it isn't already at the tail. This is | |
660 | * to prevent a transient list_empty() state when reinserting | |
661 | * an item that is already the only item in the CIL. | |
662 | */ | |
663 | if (!list_is_last(&lip->li_cil, &cil->xc_cil)) | |
664 | list_move_tail(&lip->li_cil, &cil->xc_cil); | |
665 | } | |
666 | ||
d1583a38 | 667 | spin_unlock(&cil->xc_cil_lock); |
d4ca1d55 | 668 | |
7c8ade21 DC |
669 | /* |
670 | * If we've overrun the reservation, dump the tx details before we move | |
671 | * the log items. Shutdown is imminent... | |
672 | */ | |
673 | tp->t_ticket->t_curr_res -= ctx_res + len; | |
674 | if (WARN_ON(tp->t_ticket->t_curr_res < 0)) { | |
675 | xfs_warn(log->l_mp, "Transaction log reservation overrun:"); | |
676 | xfs_warn(log->l_mp, | |
677 | " log items: %d bytes (iov hdrs: %d bytes)", | |
678 | len, iovhdr_res); | |
679 | xfs_warn(log->l_mp, " split region headers: %d bytes", | |
680 | split_res); | |
681 | xfs_warn(log->l_mp, " ctx ticket: %d bytes", ctx_res); | |
682 | xlog_print_trans(tp); | |
b5f17bec | 683 | xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR); |
7c8ade21 | 684 | } |
71e330b5 DC |
685 | } |
686 | ||
687 | static void | |
688 | xlog_cil_free_logvec( | |
689 | struct xfs_log_vec *log_vector) | |
690 | { | |
691 | struct xfs_log_vec *lv; | |
692 | ||
693 | for (lv = log_vector; lv; ) { | |
694 | struct xfs_log_vec *next = lv->lv_next; | |
71e330b5 DC |
695 | kmem_free(lv); |
696 | lv = next; | |
697 | } | |
698 | } | |
699 | ||
4560e78f CH |
700 | static void |
701 | xlog_discard_endio_work( | |
702 | struct work_struct *work) | |
703 | { | |
704 | struct xfs_cil_ctx *ctx = | |
705 | container_of(work, struct xfs_cil_ctx, discard_endio_work); | |
706 | struct xfs_mount *mp = ctx->cil->xc_log->l_mp; | |
707 | ||
708 | xfs_extent_busy_clear(mp, &ctx->busy_extents, false); | |
709 | kmem_free(ctx); | |
710 | } | |
711 | ||
712 | /* | |
713 | * Queue up the actual completion to a thread to avoid IRQ-safe locking for | |
714 | * pagb_lock. Note that we need a unbounded workqueue, otherwise we might | |
715 | * get the execution delayed up to 30 seconds for weird reasons. | |
716 | */ | |
717 | static void | |
718 | xlog_discard_endio( | |
719 | struct bio *bio) | |
720 | { | |
721 | struct xfs_cil_ctx *ctx = bio->bi_private; | |
722 | ||
723 | INIT_WORK(&ctx->discard_endio_work, xlog_discard_endio_work); | |
724 | queue_work(xfs_discard_wq, &ctx->discard_endio_work); | |
ea7bd56f | 725 | bio_put(bio); |
4560e78f CH |
726 | } |
727 | ||
728 | static void | |
729 | xlog_discard_busy_extents( | |
730 | struct xfs_mount *mp, | |
731 | struct xfs_cil_ctx *ctx) | |
732 | { | |
733 | struct list_head *list = &ctx->busy_extents; | |
734 | struct xfs_extent_busy *busyp; | |
735 | struct bio *bio = NULL; | |
736 | struct blk_plug plug; | |
737 | int error = 0; | |
738 | ||
0560f31a | 739 | ASSERT(xfs_has_discard(mp)); |
4560e78f CH |
740 | |
741 | blk_start_plug(&plug); | |
742 | list_for_each_entry(busyp, list, list) { | |
743 | trace_xfs_discard_extent(mp, busyp->agno, busyp->bno, | |
744 | busyp->length); | |
745 | ||
746 | error = __blkdev_issue_discard(mp->m_ddev_targp->bt_bdev, | |
747 | XFS_AGB_TO_DADDR(mp, busyp->agno, busyp->bno), | |
748 | XFS_FSB_TO_BB(mp, busyp->length), | |
44abff2c | 749 | GFP_NOFS, &bio); |
4560e78f CH |
750 | if (error && error != -EOPNOTSUPP) { |
751 | xfs_info(mp, | |
752 | "discard failed for extent [0x%llx,%u], error %d", | |
753 | (unsigned long long)busyp->bno, | |
754 | busyp->length, | |
755 | error); | |
756 | break; | |
757 | } | |
758 | } | |
759 | ||
760 | if (bio) { | |
761 | bio->bi_private = ctx; | |
762 | bio->bi_end_io = xlog_discard_endio; | |
763 | submit_bio(bio); | |
764 | } else { | |
765 | xlog_discard_endio_work(&ctx->discard_endio_work); | |
766 | } | |
767 | blk_finish_plug(&plug); | |
768 | } | |
769 | ||
71e330b5 DC |
770 | /* |
771 | * Mark all items committed and clear busy extents. We free the log vector | |
772 | * chains in a separate pass so that we unpin the log items as quickly as | |
773 | * possible. | |
774 | */ | |
775 | static void | |
776 | xlog_cil_committed( | |
12e6a0f4 | 777 | struct xfs_cil_ctx *ctx) |
71e330b5 | 778 | { |
e84661aa | 779 | struct xfs_mount *mp = ctx->cil->xc_log->l_mp; |
2039a272 | 780 | bool abort = xlog_is_shutdown(ctx->cil->xc_log); |
71e330b5 | 781 | |
545aa41f BF |
782 | /* |
783 | * If the I/O failed, we're aborting the commit and already shutdown. | |
784 | * Wake any commit waiters before aborting the log items so we don't | |
785 | * block async log pushers on callbacks. Async log pushers explicitly do | |
786 | * not wait on log force completion because they may be holding locks | |
787 | * required to unpin items. | |
788 | */ | |
789 | if (abort) { | |
790 | spin_lock(&ctx->cil->xc_push_lock); | |
68a74dca | 791 | wake_up_all(&ctx->cil->xc_start_wait); |
545aa41f BF |
792 | wake_up_all(&ctx->cil->xc_commit_wait); |
793 | spin_unlock(&ctx->cil->xc_push_lock); | |
794 | } | |
795 | ||
0e57f6a3 DC |
796 | xfs_trans_committed_bulk(ctx->cil->xc_log->l_ailp, ctx->lv_chain, |
797 | ctx->start_lsn, abort); | |
71e330b5 | 798 | |
4ecbfe63 DC |
799 | xfs_extent_busy_sort(&ctx->busy_extents); |
800 | xfs_extent_busy_clear(mp, &ctx->busy_extents, | |
0560f31a | 801 | xfs_has_discard(mp) && !abort); |
71e330b5 | 802 | |
4bb928cd | 803 | spin_lock(&ctx->cil->xc_push_lock); |
71e330b5 | 804 | list_del(&ctx->committing); |
4bb928cd | 805 | spin_unlock(&ctx->cil->xc_push_lock); |
71e330b5 DC |
806 | |
807 | xlog_cil_free_logvec(ctx->lv_chain); | |
e84661aa | 808 | |
4560e78f CH |
809 | if (!list_empty(&ctx->busy_extents)) |
810 | xlog_discard_busy_extents(mp, ctx); | |
811 | else | |
812 | kmem_free(ctx); | |
71e330b5 DC |
813 | } |
814 | ||
89ae379d CH |
815 | void |
816 | xlog_cil_process_committed( | |
12e6a0f4 | 817 | struct list_head *list) |
89ae379d CH |
818 | { |
819 | struct xfs_cil_ctx *ctx; | |
820 | ||
821 | while ((ctx = list_first_entry_or_null(list, | |
822 | struct xfs_cil_ctx, iclog_entry))) { | |
823 | list_del(&ctx->iclog_entry); | |
12e6a0f4 | 824 | xlog_cil_committed(ctx); |
89ae379d CH |
825 | } |
826 | } | |
827 | ||
c45aba40 DC |
828 | /* |
829 | * Record the LSN of the iclog we were just granted space to start writing into. | |
830 | * If the context doesn't have a start_lsn recorded, then this iclog will | |
831 | * contain the start record for the checkpoint. Otherwise this write contains | |
832 | * the commit record for the checkpoint. | |
833 | */ | |
834 | void | |
835 | xlog_cil_set_ctx_write_state( | |
836 | struct xfs_cil_ctx *ctx, | |
837 | struct xlog_in_core *iclog) | |
838 | { | |
839 | struct xfs_cil *cil = ctx->cil; | |
840 | xfs_lsn_t lsn = be64_to_cpu(iclog->ic_header.h_lsn); | |
841 | ||
842 | ASSERT(!ctx->commit_lsn); | |
caa80090 DC |
843 | if (!ctx->start_lsn) { |
844 | spin_lock(&cil->xc_push_lock); | |
68a74dca DC |
845 | /* |
846 | * The LSN we need to pass to the log items on transaction | |
847 | * commit is the LSN reported by the first log vector write, not | |
848 | * the commit lsn. If we use the commit record lsn then we can | |
919edbad DC |
849 | * move the grant write head beyond the tail LSN and overwrite |
850 | * it. | |
68a74dca | 851 | */ |
c45aba40 | 852 | ctx->start_lsn = lsn; |
68a74dca | 853 | wake_up_all(&cil->xc_start_wait); |
caa80090 | 854 | spin_unlock(&cil->xc_push_lock); |
919edbad DC |
855 | |
856 | /* | |
857 | * Make sure the metadata we are about to overwrite in the log | |
858 | * has been flushed to stable storage before this iclog is | |
859 | * issued. | |
860 | */ | |
861 | spin_lock(&cil->xc_log->l_icloglock); | |
862 | iclog->ic_flags |= XLOG_ICL_NEED_FLUSH; | |
863 | spin_unlock(&cil->xc_log->l_icloglock); | |
caa80090 DC |
864 | return; |
865 | } | |
866 | ||
867 | /* | |
868 | * Take a reference to the iclog for the context so that we still hold | |
869 | * it when xlog_write is done and has released it. This means the | |
870 | * context controls when the iclog is released for IO. | |
871 | */ | |
872 | atomic_inc(&iclog->ic_refcnt); | |
873 | ||
874 | /* | |
875 | * xlog_state_get_iclog_space() guarantees there is enough space in the | |
876 | * iclog for an entire commit record, so we can attach the context | |
877 | * callbacks now. This needs to be done before we make the commit_lsn | |
878 | * visible to waiters so that checkpoints with commit records in the | |
879 | * same iclog order their IO completion callbacks in the same order that | |
880 | * the commit records appear in the iclog. | |
881 | */ | |
882 | spin_lock(&cil->xc_log->l_icloglock); | |
883 | list_add_tail(&ctx->iclog_entry, &iclog->ic_callbacks); | |
884 | spin_unlock(&cil->xc_log->l_icloglock); | |
885 | ||
886 | /* | |
887 | * Now we can record the commit LSN and wake anyone waiting for this | |
888 | * sequence to have the ordered commit record assigned to a physical | |
889 | * location in the log. | |
890 | */ | |
891 | spin_lock(&cil->xc_push_lock); | |
892 | ctx->commit_iclog = iclog; | |
893 | ctx->commit_lsn = lsn; | |
894 | wake_up_all(&cil->xc_commit_wait); | |
c45aba40 DC |
895 | spin_unlock(&cil->xc_push_lock); |
896 | } | |
897 | ||
898 | ||
2ce82b72 | 899 | /* |
bf034bc8 DC |
900 | * Ensure that the order of log writes follows checkpoint sequence order. This |
901 | * relies on the context LSN being zero until the log write has guaranteed the | |
902 | * LSN that the log write will start at via xlog_state_get_iclog_space(). | |
903 | */ | |
68a74dca DC |
904 | enum _record_type { |
905 | _START_RECORD, | |
906 | _COMMIT_RECORD, | |
907 | }; | |
908 | ||
bf034bc8 DC |
909 | static int |
910 | xlog_cil_order_write( | |
911 | struct xfs_cil *cil, | |
68a74dca DC |
912 | xfs_csn_t sequence, |
913 | enum _record_type record) | |
bf034bc8 DC |
914 | { |
915 | struct xfs_cil_ctx *ctx; | |
916 | ||
917 | restart: | |
918 | spin_lock(&cil->xc_push_lock); | |
919 | list_for_each_entry(ctx, &cil->xc_committing, committing) { | |
920 | /* | |
921 | * Avoid getting stuck in this loop because we were woken by the | |
922 | * shutdown, but then went back to sleep once already in the | |
923 | * shutdown state. | |
924 | */ | |
925 | if (xlog_is_shutdown(cil->xc_log)) { | |
926 | spin_unlock(&cil->xc_push_lock); | |
927 | return -EIO; | |
928 | } | |
929 | ||
930 | /* | |
931 | * Higher sequences will wait for this one so skip them. | |
932 | * Don't wait for our own sequence, either. | |
933 | */ | |
934 | if (ctx->sequence >= sequence) | |
935 | continue; | |
68a74dca DC |
936 | |
937 | /* Wait until the LSN for the record has been recorded. */ | |
938 | switch (record) { | |
939 | case _START_RECORD: | |
940 | if (!ctx->start_lsn) { | |
941 | xlog_wait(&cil->xc_start_wait, &cil->xc_push_lock); | |
942 | goto restart; | |
943 | } | |
944 | break; | |
945 | case _COMMIT_RECORD: | |
946 | if (!ctx->commit_lsn) { | |
947 | xlog_wait(&cil->xc_commit_wait, &cil->xc_push_lock); | |
948 | goto restart; | |
949 | } | |
950 | break; | |
bf034bc8 DC |
951 | } |
952 | } | |
953 | spin_unlock(&cil->xc_push_lock); | |
954 | return 0; | |
955 | } | |
956 | ||
68a74dca DC |
957 | /* |
958 | * Write out the log vector change now attached to the CIL context. This will | |
959 | * write a start record that needs to be strictly ordered in ascending CIL | |
960 | * sequence order so that log recovery will always use in-order start LSNs when | |
961 | * replaying checkpoints. | |
962 | */ | |
963 | static int | |
964 | xlog_cil_write_chain( | |
965 | struct xfs_cil_ctx *ctx, | |
d80fc291 DC |
966 | struct xfs_log_vec *chain, |
967 | uint32_t chain_len) | |
68a74dca DC |
968 | { |
969 | struct xlog *log = ctx->cil->xc_log; | |
970 | int error; | |
971 | ||
972 | error = xlog_cil_order_write(ctx->cil, ctx->sequence, _START_RECORD); | |
973 | if (error) | |
974 | return error; | |
14b07ecd | 975 | return xlog_write(log, ctx, chain, ctx->ticket, chain_len); |
68a74dca DC |
976 | } |
977 | ||
bf034bc8 DC |
978 | /* |
979 | * Write out the commit record of a checkpoint transaction to close off a | |
980 | * running log write. These commit records are strictly ordered in ascending CIL | |
981 | * sequence order so that log recovery will always replay the checkpoints in the | |
982 | * correct order. | |
2ce82b72 DC |
983 | */ |
984 | static int | |
985 | xlog_cil_write_commit_record( | |
caa80090 | 986 | struct xfs_cil_ctx *ctx) |
2ce82b72 | 987 | { |
c45aba40 | 988 | struct xlog *log = ctx->cil->xc_log; |
54021b62 DC |
989 | struct xlog_op_header ophdr = { |
990 | .oh_clientid = XFS_TRANSACTION, | |
991 | .oh_tid = cpu_to_be32(ctx->ticket->t_tid), | |
992 | .oh_flags = XLOG_COMMIT_TRANS, | |
993 | }; | |
c45aba40 | 994 | struct xfs_log_iovec reg = { |
54021b62 DC |
995 | .i_addr = &ophdr, |
996 | .i_len = sizeof(struct xlog_op_header), | |
2ce82b72 DC |
997 | .i_type = XLOG_REG_TYPE_COMMIT, |
998 | }; | |
c45aba40 | 999 | struct xfs_log_vec vec = { |
2ce82b72 DC |
1000 | .lv_niovecs = 1, |
1001 | .lv_iovecp = ®, | |
1002 | }; | |
c45aba40 | 1003 | int error; |
2ce82b72 DC |
1004 | |
1005 | if (xlog_is_shutdown(log)) | |
1006 | return -EIO; | |
1007 | ||
68a74dca DC |
1008 | error = xlog_cil_order_write(ctx->cil, ctx->sequence, _COMMIT_RECORD); |
1009 | if (error) | |
1010 | return error; | |
1011 | ||
54021b62 DC |
1012 | /* account for space used by record data */ |
1013 | ctx->ticket->t_curr_res -= reg.i_len; | |
14b07ecd | 1014 | error = xlog_write(log, ctx, &vec, ctx->ticket, reg.i_len); |
2ce82b72 | 1015 | if (error) |
b5f17bec | 1016 | xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR); |
2ce82b72 DC |
1017 | return error; |
1018 | } | |
1019 | ||
735fbf67 | 1020 | struct xlog_cil_trans_hdr { |
6eaed95e | 1021 | struct xlog_op_header oph[2]; |
735fbf67 | 1022 | struct xfs_trans_header thdr; |
6eaed95e | 1023 | struct xfs_log_iovec lhdr[2]; |
735fbf67 DC |
1024 | }; |
1025 | ||
1026 | /* | |
1027 | * Build a checkpoint transaction header to begin the journal transaction. We | |
1028 | * need to account for the space used by the transaction header here as it is | |
1029 | * not accounted for in xlog_write(). | |
6eaed95e DC |
1030 | * |
1031 | * This is the only place we write a transaction header, so we also build the | |
1032 | * log opheaders that indicate the start of a log transaction and wrap the | |
1033 | * transaction header. We keep the start record in it's own log vector rather | |
1034 | * than compacting them into a single region as this ends up making the logic | |
1035 | * in xlog_write() for handling empty opheaders for start, commit and unmount | |
1036 | * records much simpler. | |
735fbf67 DC |
1037 | */ |
1038 | static void | |
1039 | xlog_cil_build_trans_hdr( | |
1040 | struct xfs_cil_ctx *ctx, | |
1041 | struct xlog_cil_trans_hdr *hdr, | |
1042 | struct xfs_log_vec *lvhdr, | |
1043 | int num_iovecs) | |
1044 | { | |
1045 | struct xlog_ticket *tic = ctx->ticket; | |
6eaed95e | 1046 | __be32 tid = cpu_to_be32(tic->t_tid); |
735fbf67 DC |
1047 | |
1048 | memset(hdr, 0, sizeof(*hdr)); | |
1049 | ||
6eaed95e DC |
1050 | /* Log start record */ |
1051 | hdr->oph[0].oh_tid = tid; | |
1052 | hdr->oph[0].oh_clientid = XFS_TRANSACTION; | |
1053 | hdr->oph[0].oh_flags = XLOG_START_TRANS; | |
1054 | ||
1055 | /* log iovec region pointer */ | |
1056 | hdr->lhdr[0].i_addr = &hdr->oph[0]; | |
1057 | hdr->lhdr[0].i_len = sizeof(struct xlog_op_header); | |
1058 | hdr->lhdr[0].i_type = XLOG_REG_TYPE_LRHEADER; | |
1059 | ||
1060 | /* log opheader */ | |
1061 | hdr->oph[1].oh_tid = tid; | |
1062 | hdr->oph[1].oh_clientid = XFS_TRANSACTION; | |
1063 | hdr->oph[1].oh_len = cpu_to_be32(sizeof(struct xfs_trans_header)); | |
1064 | ||
1065 | /* transaction header in host byte order format */ | |
735fbf67 DC |
1066 | hdr->thdr.th_magic = XFS_TRANS_HEADER_MAGIC; |
1067 | hdr->thdr.th_type = XFS_TRANS_CHECKPOINT; | |
1068 | hdr->thdr.th_tid = tic->t_tid; | |
1069 | hdr->thdr.th_num_items = num_iovecs; | |
735fbf67 | 1070 | |
6eaed95e DC |
1071 | /* log iovec region pointer */ |
1072 | hdr->lhdr[1].i_addr = &hdr->oph[1]; | |
1073 | hdr->lhdr[1].i_len = sizeof(struct xlog_op_header) + | |
1074 | sizeof(struct xfs_trans_header); | |
1075 | hdr->lhdr[1].i_type = XLOG_REG_TYPE_TRANSHDR; | |
1076 | ||
6eaed95e DC |
1077 | lvhdr->lv_niovecs = 2; |
1078 | lvhdr->lv_iovecp = &hdr->lhdr[0]; | |
d80fc291 | 1079 | lvhdr->lv_bytes = hdr->lhdr[0].i_len + hdr->lhdr[1].i_len; |
735fbf67 | 1080 | lvhdr->lv_next = ctx->lv_chain; |
d80fc291 DC |
1081 | |
1082 | tic->t_curr_res -= lvhdr->lv_bytes; | |
735fbf67 DC |
1083 | } |
1084 | ||
22b1afc5 DC |
1085 | /* |
1086 | * Pull all the log vectors off the items in the CIL, and remove the items from | |
1087 | * the CIL. We don't need the CIL lock here because it's only needed on the | |
1088 | * transaction commit side which is currently locked out by the flush lock. | |
0d227466 DC |
1089 | * |
1090 | * If a log item is marked with a whiteout, we do not need to write it to the | |
1091 | * journal and so we just move them to the whiteout list for the caller to | |
1092 | * dispose of appropriately. | |
22b1afc5 DC |
1093 | */ |
1094 | static void | |
1095 | xlog_cil_build_lv_chain( | |
1096 | struct xfs_cil *cil, | |
1097 | struct xfs_cil_ctx *ctx, | |
0d227466 | 1098 | struct list_head *whiteouts, |
22b1afc5 DC |
1099 | uint32_t *num_iovecs, |
1100 | uint32_t *num_bytes) | |
1101 | { | |
1102 | struct xfs_log_vec *lv = NULL; | |
1103 | ||
1104 | while (!list_empty(&cil->xc_cil)) { | |
1105 | struct xfs_log_item *item; | |
1106 | ||
1107 | item = list_first_entry(&cil->xc_cil, | |
1108 | struct xfs_log_item, li_cil); | |
0d227466 DC |
1109 | |
1110 | if (test_bit(XFS_LI_WHITEOUT, &item->li_flags)) { | |
1111 | list_move(&item->li_cil, whiteouts); | |
1112 | trace_xfs_cil_whiteout_skip(item); | |
1113 | continue; | |
1114 | } | |
1115 | ||
22b1afc5 DC |
1116 | list_del_init(&item->li_cil); |
1117 | if (!ctx->lv_chain) | |
1118 | ctx->lv_chain = item->li_lv; | |
1119 | else | |
1120 | lv->lv_next = item->li_lv; | |
1121 | lv = item->li_lv; | |
1122 | item->li_lv = NULL; | |
1123 | *num_iovecs += lv->lv_niovecs; | |
1124 | ||
1125 | /* we don't write ordered log vectors */ | |
1126 | if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED) | |
1127 | *num_bytes += lv->lv_bytes; | |
1128 | } | |
1129 | } | |
1130 | ||
0d227466 DC |
1131 | static void |
1132 | xlog_cil_cleanup_whiteouts( | |
1133 | struct list_head *whiteouts) | |
1134 | { | |
1135 | while (!list_empty(whiteouts)) { | |
1136 | struct xfs_log_item *item = list_first_entry(whiteouts, | |
1137 | struct xfs_log_item, li_cil); | |
1138 | list_del_init(&item->li_cil); | |
1139 | trace_xfs_cil_whiteout_unpin(item); | |
1140 | item->li_ops->iop_unpin(item, 1); | |
1141 | } | |
1142 | } | |
1143 | ||
71e330b5 | 1144 | /* |
c7cc296d CH |
1145 | * Push the Committed Item List to the log. |
1146 | * | |
1147 | * If the current sequence is the same as xc_push_seq we need to do a flush. If | |
1148 | * xc_push_seq is less than the current sequence, then it has already been | |
a44f13ed DC |
1149 | * flushed and we don't need to do anything - the caller will wait for it to |
1150 | * complete if necessary. | |
1151 | * | |
c7cc296d CH |
1152 | * xc_push_seq is checked unlocked against the sequence number for a match. |
1153 | * Hence we can allow log forces to run racily and not issue pushes for the | |
1154 | * same sequence twice. If we get a race between multiple pushes for the same | |
1155 | * sequence they will block on the first one and then abort, hence avoiding | |
1156 | * needless pushes. | |
71e330b5 | 1157 | */ |
c7cc296d CH |
1158 | static void |
1159 | xlog_cil_push_work( | |
1160 | struct work_struct *work) | |
71e330b5 | 1161 | { |
39823d0f DC |
1162 | struct xfs_cil_ctx *ctx = |
1163 | container_of(work, struct xfs_cil_ctx, push_work); | |
1164 | struct xfs_cil *cil = ctx->cil; | |
c7cc296d | 1165 | struct xlog *log = cil->xc_log; |
71e330b5 | 1166 | struct xfs_cil_ctx *new_ctx; |
d80fc291 DC |
1167 | int num_iovecs = 0; |
1168 | int num_bytes = 0; | |
71e330b5 | 1169 | int error = 0; |
735fbf67 | 1170 | struct xlog_cil_trans_hdr thdr; |
71e330b5 | 1171 | struct xfs_log_vec lvhdr = { NULL }; |
0dc8f7f1 | 1172 | xfs_csn_t push_seq; |
0020a190 | 1173 | bool push_commit_stable; |
0d227466 | 1174 | LIST_HEAD (whiteouts); |
71e330b5 | 1175 | |
39823d0f | 1176 | new_ctx = xlog_cil_ctx_alloc(); |
71e330b5 DC |
1177 | new_ctx->ticket = xlog_cil_ticket_alloc(log); |
1178 | ||
4c2d542f | 1179 | down_write(&cil->xc_ctx_lock); |
71e330b5 | 1180 | |
4bb928cd | 1181 | spin_lock(&cil->xc_push_lock); |
4c2d542f DC |
1182 | push_seq = cil->xc_push_seq; |
1183 | ASSERT(push_seq <= ctx->sequence); | |
0020a190 DC |
1184 | push_commit_stable = cil->xc_push_commit_stable; |
1185 | cil->xc_push_commit_stable = false; | |
71e330b5 | 1186 | |
0e7ab7ef | 1187 | /* |
19f4e7cc DC |
1188 | * As we are about to switch to a new, empty CIL context, we no longer |
1189 | * need to throttle tasks on CIL space overruns. Wake any waiters that | |
1190 | * the hard push throttle may have caught so they can start committing | |
1191 | * to the new context. The ctx->xc_push_lock provides the serialisation | |
1192 | * necessary for safely using the lockless waitqueue_active() check in | |
1193 | * this context. | |
0e7ab7ef | 1194 | */ |
19f4e7cc | 1195 | if (waitqueue_active(&cil->xc_push_wait)) |
c7f87f39 | 1196 | wake_up_all(&cil->xc_push_wait); |
0e7ab7ef | 1197 | |
7c8ade21 DC |
1198 | xlog_cil_push_pcp_aggregate(cil, ctx); |
1199 | ||
4c2d542f DC |
1200 | /* |
1201 | * Check if we've anything to push. If there is nothing, then we don't | |
1202 | * move on to a new sequence number and so we have to be able to push | |
1203 | * this sequence again later. | |
1204 | */ | |
88591e7f | 1205 | if (test_bit(XLOG_CIL_EMPTY, &cil->xc_flags)) { |
4c2d542f | 1206 | cil->xc_push_seq = 0; |
4bb928cd | 1207 | spin_unlock(&cil->xc_push_lock); |
a44f13ed | 1208 | goto out_skip; |
4c2d542f | 1209 | } |
4c2d542f | 1210 | |
a44f13ed | 1211 | |
cf085a1b | 1212 | /* check for a previously pushed sequence */ |
39823d0f | 1213 | if (push_seq < ctx->sequence) { |
8af3dcd3 | 1214 | spin_unlock(&cil->xc_push_lock); |
df806158 | 1215 | goto out_skip; |
8af3dcd3 DC |
1216 | } |
1217 | ||
1218 | /* | |
1219 | * We are now going to push this context, so add it to the committing | |
1220 | * list before we do anything else. This ensures that anyone waiting on | |
1221 | * this push can easily detect the difference between a "push in | |
1222 | * progress" and "CIL is empty, nothing to do". | |
1223 | * | |
1224 | * IOWs, a wait loop can now check for: | |
1225 | * the current sequence not being found on the committing list; | |
1226 | * an empty CIL; and | |
1227 | * an unchanged sequence number | |
1228 | * to detect a push that had nothing to do and therefore does not need | |
1229 | * waiting on. If the CIL is not empty, we get put on the committing | |
1230 | * list before emptying the CIL and bumping the sequence number. Hence | |
1231 | * an empty CIL and an unchanged sequence number means we jumped out | |
1232 | * above after doing nothing. | |
1233 | * | |
1234 | * Hence the waiter will either find the commit sequence on the | |
1235 | * committing list or the sequence number will be unchanged and the CIL | |
1236 | * still dirty. In that latter case, the push has not yet started, and | |
1237 | * so the waiter will have to continue trying to check the CIL | |
1238 | * committing list until it is found. In extreme cases of delay, the | |
1239 | * sequence may fully commit between the attempts the wait makes to wait | |
1240 | * on the commit sequence. | |
1241 | */ | |
1242 | list_add(&ctx->committing, &cil->xc_committing); | |
1243 | spin_unlock(&cil->xc_push_lock); | |
df806158 | 1244 | |
0d227466 | 1245 | xlog_cil_build_lv_chain(cil, ctx, &whiteouts, &num_iovecs, &num_bytes); |
71e330b5 DC |
1246 | |
1247 | /* | |
39823d0f | 1248 | * Switch the contexts so we can drop the context lock and move out |
71e330b5 DC |
1249 | * of a shared context. We can't just go straight to the commit record, |
1250 | * though - we need to synchronise with previous and future commits so | |
1251 | * that the commit records are correctly ordered in the log to ensure | |
1252 | * that we process items during log IO completion in the correct order. | |
1253 | * | |
1254 | * For example, if we get an EFI in one checkpoint and the EFD in the | |
1255 | * next (e.g. due to log forces), we do not want the checkpoint with | |
1256 | * the EFD to be committed before the checkpoint with the EFI. Hence | |
1257 | * we must strictly order the commit records of the checkpoints so | |
1258 | * that: a) the checkpoint callbacks are attached to the iclogs in the | |
1259 | * correct order; and b) the checkpoints are replayed in correct order | |
1260 | * in log recovery. | |
1261 | * | |
1262 | * Hence we need to add this context to the committing context list so | |
1263 | * that higher sequences will wait for us to write out a commit record | |
1264 | * before they do. | |
f876e446 | 1265 | * |
5f9b4b0d | 1266 | * xfs_log_force_seq requires us to mirror the new sequence into the cil |
f876e446 DC |
1267 | * structure atomically with the addition of this sequence to the |
1268 | * committing list. This also ensures that we can do unlocked checks | |
1269 | * against the current sequence in log forces without risking | |
1270 | * deferencing a freed context pointer. | |
71e330b5 | 1271 | */ |
4bb928cd | 1272 | spin_lock(&cil->xc_push_lock); |
39823d0f | 1273 | xlog_cil_ctx_switch(cil, new_ctx); |
4bb928cd | 1274 | spin_unlock(&cil->xc_push_lock); |
71e330b5 DC |
1275 | up_write(&cil->xc_ctx_lock); |
1276 | ||
1277 | /* | |
1278 | * Build a checkpoint transaction header and write it to the log to | |
1279 | * begin the transaction. We need to account for the space used by the | |
1280 | * transaction header here as it is not accounted for in xlog_write(). | |
71e330b5 | 1281 | */ |
735fbf67 | 1282 | xlog_cil_build_trans_hdr(ctx, &thdr, &lvhdr, num_iovecs); |
d80fc291 | 1283 | num_bytes += lvhdr.lv_bytes; |
71e330b5 | 1284 | |
d80fc291 | 1285 | error = xlog_cil_write_chain(ctx, &lvhdr, num_bytes); |
bf034bc8 DC |
1286 | if (error) |
1287 | goto out_abort_free_ticket; | |
71e330b5 | 1288 | |
caa80090 | 1289 | error = xlog_cil_write_commit_record(ctx); |
dd401770 DC |
1290 | if (error) |
1291 | goto out_abort_free_ticket; | |
1292 | ||
735fbf67 | 1293 | xfs_log_ticket_ungrant(log, ctx->ticket); |
71e330b5 | 1294 | |
a79b28c2 | 1295 | /* |
1effb72a DC |
1296 | * If the checkpoint spans multiple iclogs, wait for all previous iclogs |
1297 | * to complete before we submit the commit_iclog. We can't use state | |
1298 | * checks for this - ACTIVE can be either a past completed iclog or a | |
1299 | * future iclog being filled, while WANT_SYNC through SYNC_DONE can be a | |
1300 | * past or future iclog awaiting IO or ordered IO completion to be run. | |
1301 | * In the latter case, if it's a future iclog and we wait on it, the we | |
1302 | * will hang because it won't get processed through to ic_force_wait | |
1303 | * wakeup until this commit_iclog is written to disk. Hence we use the | |
1304 | * iclog header lsn and compare it to the commit lsn to determine if we | |
1305 | * need to wait on iclogs or not. | |
a79b28c2 | 1306 | */ |
caa80090 | 1307 | spin_lock(&log->l_icloglock); |
c45aba40 | 1308 | if (ctx->start_lsn != ctx->commit_lsn) { |
1effb72a DC |
1309 | xfs_lsn_t plsn; |
1310 | ||
caa80090 | 1311 | plsn = be64_to_cpu(ctx->commit_iclog->ic_prev->ic_header.h_lsn); |
c45aba40 | 1312 | if (plsn && XFS_LSN_CMP(plsn, ctx->commit_lsn) < 0) { |
1effb72a DC |
1313 | /* |
1314 | * Waiting on ic_force_wait orders the completion of | |
1315 | * iclogs older than ic_prev. Hence we only need to wait | |
1316 | * on the most recent older iclog here. | |
1317 | */ | |
caa80090 | 1318 | xlog_wait_on_iclog(ctx->commit_iclog->ic_prev); |
1effb72a DC |
1319 | spin_lock(&log->l_icloglock); |
1320 | } | |
1321 | ||
1322 | /* | |
1323 | * We need to issue a pre-flush so that the ordering for this | |
1324 | * checkpoint is correctly preserved down to stable storage. | |
1325 | */ | |
caa80090 | 1326 | ctx->commit_iclog->ic_flags |= XLOG_ICL_NEED_FLUSH; |
a79b28c2 DC |
1327 | } |
1328 | ||
eef983ff DC |
1329 | /* |
1330 | * The commit iclog must be written to stable storage to guarantee | |
1331 | * journal IO vs metadata writeback IO is correctly ordered on stable | |
1332 | * storage. | |
0020a190 DC |
1333 | * |
1334 | * If the push caller needs the commit to be immediately stable and the | |
1335 | * commit_iclog is not yet marked as XLOG_STATE_WANT_SYNC to indicate it | |
1336 | * will be written when released, switch it's state to WANT_SYNC right | |
1337 | * now. | |
eef983ff | 1338 | */ |
caa80090 | 1339 | ctx->commit_iclog->ic_flags |= XLOG_ICL_NEED_FUA; |
0020a190 DC |
1340 | if (push_commit_stable && |
1341 | ctx->commit_iclog->ic_state == XLOG_STATE_ACTIVE) | |
1342 | xlog_state_switch_iclogs(log, ctx->commit_iclog, 0); | |
919edbad | 1343 | xlog_state_release_iclog(log, ctx->commit_iclog); |
502a01fa DC |
1344 | |
1345 | /* Not safe to reference ctx now! */ | |
1346 | ||
eef983ff | 1347 | spin_unlock(&log->l_icloglock); |
0d227466 | 1348 | xlog_cil_cleanup_whiteouts(&whiteouts); |
c7cc296d | 1349 | return; |
71e330b5 DC |
1350 | |
1351 | out_skip: | |
1352 | up_write(&cil->xc_ctx_lock); | |
1353 | xfs_log_ticket_put(new_ctx->ticket); | |
1354 | kmem_free(new_ctx); | |
c7cc296d | 1355 | return; |
71e330b5 | 1356 | |
7db37c5e | 1357 | out_abort_free_ticket: |
735fbf67 | 1358 | xfs_log_ticket_ungrant(log, ctx->ticket); |
2039a272 | 1359 | ASSERT(xlog_is_shutdown(log)); |
0d227466 | 1360 | xlog_cil_cleanup_whiteouts(&whiteouts); |
caa80090 DC |
1361 | if (!ctx->commit_iclog) { |
1362 | xlog_cil_committed(ctx); | |
1363 | return; | |
1364 | } | |
1365 | spin_lock(&log->l_icloglock); | |
919edbad | 1366 | xlog_state_release_iclog(log, ctx->commit_iclog); |
caa80090 DC |
1367 | /* Not safe to reference ctx now! */ |
1368 | spin_unlock(&log->l_icloglock); | |
4c2d542f DC |
1369 | } |
1370 | ||
1371 | /* | |
1372 | * We need to push CIL every so often so we don't cache more than we can fit in | |
1373 | * the log. The limit really is that a checkpoint can't be more than half the | |
1374 | * log (the current checkpoint is not allowed to overwrite the previous | |
1375 | * checkpoint), but commit latency and memory usage limit this to a smaller | |
1376 | * size. | |
1377 | */ | |
1378 | static void | |
1379 | xlog_cil_push_background( | |
0e7ab7ef | 1380 | struct xlog *log) __releases(cil->xc_ctx_lock) |
4c2d542f DC |
1381 | { |
1382 | struct xfs_cil *cil = log->l_cilp; | |
7c8ade21 | 1383 | int space_used = atomic_read(&cil->xc_ctx->space_used); |
4c2d542f DC |
1384 | |
1385 | /* | |
1386 | * The cil won't be empty because we are called while holding the | |
88591e7f | 1387 | * context lock so whatever we added to the CIL will still be there. |
4c2d542f DC |
1388 | */ |
1389 | ASSERT(!list_empty(&cil->xc_cil)); | |
88591e7f | 1390 | ASSERT(!test_bit(XLOG_CIL_EMPTY, &cil->xc_flags)); |
4c2d542f DC |
1391 | |
1392 | /* | |
19f4e7cc | 1393 | * Don't do a background push if we haven't used up all the |
4c2d542f DC |
1394 | * space available yet. |
1395 | */ | |
7c8ade21 | 1396 | if (space_used < XLOG_CIL_SPACE_LIMIT(log)) { |
0e7ab7ef | 1397 | up_read(&cil->xc_ctx_lock); |
4c2d542f | 1398 | return; |
0e7ab7ef | 1399 | } |
4c2d542f | 1400 | |
4bb928cd | 1401 | spin_lock(&cil->xc_push_lock); |
4c2d542f DC |
1402 | if (cil->xc_push_seq < cil->xc_current_sequence) { |
1403 | cil->xc_push_seq = cil->xc_current_sequence; | |
33c0dd78 | 1404 | queue_work(cil->xc_push_wq, &cil->xc_ctx->push_work); |
4c2d542f | 1405 | } |
0e7ab7ef DC |
1406 | |
1407 | /* | |
1408 | * Drop the context lock now, we can't hold that if we need to sleep | |
1409 | * because we are over the blocking threshold. The push_lock is still | |
1410 | * held, so blocking threshold sleep/wakeup is still correctly | |
1411 | * serialised here. | |
1412 | */ | |
1413 | up_read(&cil->xc_ctx_lock); | |
1414 | ||
1415 | /* | |
1416 | * If we are well over the space limit, throttle the work that is being | |
19f4e7cc DC |
1417 | * done until the push work on this context has begun. Enforce the hard |
1418 | * throttle on all transaction commits once it has been activated, even | |
1419 | * if the committing transactions have resulted in the space usage | |
1420 | * dipping back down under the hard limit. | |
1421 | * | |
1422 | * The ctx->xc_push_lock provides the serialisation necessary for safely | |
7c8ade21 | 1423 | * calling xlog_cil_over_hard_limit() in this context. |
0e7ab7ef | 1424 | */ |
7c8ade21 | 1425 | if (xlog_cil_over_hard_limit(log, space_used)) { |
0e7ab7ef | 1426 | trace_xfs_log_cil_wait(log, cil->xc_ctx->ticket); |
7c8ade21 | 1427 | ASSERT(space_used < log->l_logsize); |
c7f87f39 | 1428 | xlog_wait(&cil->xc_push_wait, &cil->xc_push_lock); |
0e7ab7ef DC |
1429 | return; |
1430 | } | |
1431 | ||
4bb928cd | 1432 | spin_unlock(&cil->xc_push_lock); |
4c2d542f DC |
1433 | |
1434 | } | |
1435 | ||
f876e446 DC |
1436 | /* |
1437 | * xlog_cil_push_now() is used to trigger an immediate CIL push to the sequence | |
1438 | * number that is passed. When it returns, the work will be queued for | |
0020a190 DC |
1439 | * @push_seq, but it won't be completed. |
1440 | * | |
1441 | * If the caller is performing a synchronous force, we will flush the workqueue | |
1442 | * to get previously queued work moving to minimise the wait time they will | |
1443 | * undergo waiting for all outstanding pushes to complete. The caller is | |
1444 | * expected to do the required waiting for push_seq to complete. | |
1445 | * | |
1446 | * If the caller is performing an async push, we need to ensure that the | |
1447 | * checkpoint is fully flushed out of the iclogs when we finish the push. If we | |
1448 | * don't do this, then the commit record may remain sitting in memory in an | |
1449 | * ACTIVE iclog. This then requires another full log force to push to disk, | |
1450 | * which defeats the purpose of having an async, non-blocking CIL force | |
1451 | * mechanism. Hence in this case we need to pass a flag to the push work to | |
1452 | * indicate it needs to flush the commit record itself. | |
f876e446 | 1453 | */ |
4c2d542f | 1454 | static void |
f876e446 | 1455 | xlog_cil_push_now( |
f7bdf03a | 1456 | struct xlog *log, |
0020a190 DC |
1457 | xfs_lsn_t push_seq, |
1458 | bool async) | |
4c2d542f DC |
1459 | { |
1460 | struct xfs_cil *cil = log->l_cilp; | |
1461 | ||
1462 | if (!cil) | |
1463 | return; | |
1464 | ||
1465 | ASSERT(push_seq && push_seq <= cil->xc_current_sequence); | |
1466 | ||
1467 | /* start on any pending background push to minimise wait time on it */ | |
0020a190 | 1468 | if (!async) |
33c0dd78 | 1469 | flush_workqueue(cil->xc_push_wq); |
4c2d542f | 1470 | |
70447e0a DC |
1471 | spin_lock(&cil->xc_push_lock); |
1472 | ||
1473 | /* | |
1474 | * If this is an async flush request, we always need to set the | |
1475 | * xc_push_commit_stable flag even if something else has already queued | |
1476 | * a push. The flush caller is asking for the CIL to be on stable | |
1477 | * storage when the next push completes, so regardless of who has queued | |
1478 | * the push, the flush requires stable semantics from it. | |
1479 | */ | |
1480 | cil->xc_push_commit_stable = async; | |
1481 | ||
4c2d542f DC |
1482 | /* |
1483 | * If the CIL is empty or we've already pushed the sequence then | |
70447e0a | 1484 | * there's no more work that we need to do. |
4c2d542f | 1485 | */ |
88591e7f DC |
1486 | if (test_bit(XLOG_CIL_EMPTY, &cil->xc_flags) || |
1487 | push_seq <= cil->xc_push_seq) { | |
4bb928cd | 1488 | spin_unlock(&cil->xc_push_lock); |
4c2d542f DC |
1489 | return; |
1490 | } | |
1491 | ||
1492 | cil->xc_push_seq = push_seq; | |
33c0dd78 | 1493 | queue_work(cil->xc_push_wq, &cil->xc_ctx->push_work); |
4bb928cd | 1494 | spin_unlock(&cil->xc_push_lock); |
4c2d542f DC |
1495 | } |
1496 | ||
2c6e24ce DC |
1497 | bool |
1498 | xlog_cil_empty( | |
1499 | struct xlog *log) | |
1500 | { | |
1501 | struct xfs_cil *cil = log->l_cilp; | |
1502 | bool empty = false; | |
1503 | ||
1504 | spin_lock(&cil->xc_push_lock); | |
88591e7f | 1505 | if (test_bit(XLOG_CIL_EMPTY, &cil->xc_flags)) |
2c6e24ce DC |
1506 | empty = true; |
1507 | spin_unlock(&cil->xc_push_lock); | |
1508 | return empty; | |
1509 | } | |
1510 | ||
0d227466 DC |
1511 | /* |
1512 | * If there are intent done items in this transaction and the related intent was | |
1513 | * committed in the current (same) CIL checkpoint, we don't need to write either | |
1514 | * the intent or intent done item to the journal as the change will be | |
1515 | * journalled atomically within this checkpoint. As we cannot remove items from | |
1516 | * the CIL here, mark the related intent with a whiteout so that the CIL push | |
1517 | * can remove it rather than writing it to the journal. Then remove the intent | |
1518 | * done item from the current transaction and release it so it doesn't get put | |
1519 | * into the CIL at all. | |
1520 | */ | |
1521 | static uint32_t | |
1522 | xlog_cil_process_intents( | |
1523 | struct xfs_cil *cil, | |
1524 | struct xfs_trans *tp) | |
1525 | { | |
1526 | struct xfs_log_item *lip, *ilip, *next; | |
1527 | uint32_t len = 0; | |
1528 | ||
1529 | list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) { | |
1530 | if (!(lip->li_ops->flags & XFS_ITEM_INTENT_DONE)) | |
1531 | continue; | |
1532 | ||
1533 | ilip = lip->li_ops->iop_intent(lip); | |
1534 | if (!ilip || !xlog_item_in_current_chkpt(cil, ilip)) | |
1535 | continue; | |
1536 | set_bit(XFS_LI_WHITEOUT, &ilip->li_flags); | |
1537 | trace_xfs_cil_whiteout_mark(ilip); | |
1538 | len += ilip->li_lv->lv_bytes; | |
1539 | kmem_free(ilip->li_lv); | |
1540 | ilip->li_lv = NULL; | |
1541 | ||
1542 | xfs_trans_del_item(lip); | |
1543 | lip->li_ops->iop_release(lip); | |
1544 | } | |
1545 | return len; | |
1546 | } | |
1547 | ||
a44f13ed DC |
1548 | /* |
1549 | * Commit a transaction with the given vector to the Committed Item List. | |
1550 | * | |
1551 | * To do this, we need to format the item, pin it in memory if required and | |
1552 | * account for the space used by the transaction. Once we have done that we | |
1553 | * need to release the unused reservation for the transaction, attach the | |
1554 | * transaction to the checkpoint context so we carry the busy extents through | |
1555 | * to checkpoint completion, and then unlock all the items in the transaction. | |
1556 | * | |
a44f13ed DC |
1557 | * Called with the context lock already held in read mode to lock out |
1558 | * background commit, returns without it held once background commits are | |
1559 | * allowed again. | |
1560 | */ | |
c6f97264 | 1561 | void |
5f9b4b0d DC |
1562 | xlog_cil_commit( |
1563 | struct xlog *log, | |
a44f13ed | 1564 | struct xfs_trans *tp, |
5f9b4b0d | 1565 | xfs_csn_t *commit_seq, |
70393313 | 1566 | bool regrant) |
a44f13ed | 1567 | { |
991aaf65 | 1568 | struct xfs_cil *cil = log->l_cilp; |
195cd83d | 1569 | struct xfs_log_item *lip, *next; |
0d227466 | 1570 | uint32_t released_space = 0; |
a44f13ed | 1571 | |
b1c5ebb2 DC |
1572 | /* |
1573 | * Do all necessary memory allocation before we lock the CIL. | |
1574 | * This ensures the allocation does not deadlock with a CIL | |
1575 | * push in memory reclaim (e.g. from kswapd). | |
1576 | */ | |
1577 | xlog_cil_alloc_shadow_bufs(log, tp); | |
1578 | ||
f5baac35 | 1579 | /* lock out background commit */ |
991aaf65 | 1580 | down_read(&cil->xc_ctx_lock); |
f5baac35 | 1581 | |
0d227466 DC |
1582 | if (tp->t_flags & XFS_TRANS_HAS_INTENT_DONE) |
1583 | released_space = xlog_cil_process_intents(cil, tp); | |
1584 | ||
1585 | xlog_cil_insert_items(log, tp, released_space); | |
a44f13ed | 1586 | |
2039a272 | 1587 | if (regrant && !xlog_is_shutdown(log)) |
8b41e3f9 CH |
1588 | xfs_log_ticket_regrant(log, tp->t_ticket); |
1589 | else | |
1590 | xfs_log_ticket_ungrant(log, tp->t_ticket); | |
ba18781b | 1591 | tp->t_ticket = NULL; |
a44f13ed DC |
1592 | xfs_trans_unreserve_and_mod_sb(tp); |
1593 | ||
1594 | /* | |
1595 | * Once all the items of the transaction have been copied to the CIL, | |
195cd83d | 1596 | * the items can be unlocked and possibly freed. |
a44f13ed DC |
1597 | * |
1598 | * This needs to be done before we drop the CIL context lock because we | |
1599 | * have to update state in the log items and unlock them before they go | |
1600 | * to disk. If we don't, then the CIL checkpoint can race with us and | |
1601 | * we can run checkpoint completion before we've updated and unlocked | |
1602 | * the log items. This affects (at least) processing of stale buffers, | |
1603 | * inodes and EFIs. | |
1604 | */ | |
195cd83d CH |
1605 | trace_xfs_trans_commit_items(tp, _RET_IP_); |
1606 | list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) { | |
1607 | xfs_trans_del_item(lip); | |
1608 | if (lip->li_ops->iop_committing) | |
5f9b4b0d | 1609 | lip->li_ops->iop_committing(lip, cil->xc_ctx->sequence); |
195cd83d | 1610 | } |
5f9b4b0d DC |
1611 | if (commit_seq) |
1612 | *commit_seq = cil->xc_ctx->sequence; | |
a44f13ed | 1613 | |
0e7ab7ef DC |
1614 | /* xlog_cil_push_background() releases cil->xc_ctx_lock */ |
1615 | xlog_cil_push_background(log); | |
a44f13ed DC |
1616 | } |
1617 | ||
0020a190 DC |
1618 | /* |
1619 | * Flush the CIL to stable storage but don't wait for it to complete. This | |
1620 | * requires the CIL push to ensure the commit record for the push hits the disk, | |
1621 | * but otherwise is no different to a push done from a log force. | |
1622 | */ | |
1623 | void | |
1624 | xlog_cil_flush( | |
1625 | struct xlog *log) | |
1626 | { | |
1627 | xfs_csn_t seq = log->l_cilp->xc_current_sequence; | |
1628 | ||
1629 | trace_xfs_log_force(log->l_mp, seq, _RET_IP_); | |
1630 | xlog_cil_push_now(log, seq, true); | |
70447e0a DC |
1631 | |
1632 | /* | |
1633 | * If the CIL is empty, make sure that any previous checkpoint that may | |
1634 | * still be in an active iclog is pushed to stable storage. | |
1635 | */ | |
1636 | if (list_empty(&log->l_cilp->xc_cil)) | |
1637 | xfs_log_force(log->l_mp, 0); | |
0020a190 DC |
1638 | } |
1639 | ||
71e330b5 DC |
1640 | /* |
1641 | * Conditionally push the CIL based on the sequence passed in. | |
1642 | * | |
0020a190 DC |
1643 | * We only need to push if we haven't already pushed the sequence number given. |
1644 | * Hence the only time we will trigger a push here is if the push sequence is | |
1645 | * the same as the current context. | |
71e330b5 DC |
1646 | * |
1647 | * We return the current commit lsn to allow the callers to determine if a | |
1648 | * iclog flush is necessary following this call. | |
71e330b5 DC |
1649 | */ |
1650 | xfs_lsn_t | |
5f9b4b0d | 1651 | xlog_cil_force_seq( |
f7bdf03a | 1652 | struct xlog *log, |
5f9b4b0d | 1653 | xfs_csn_t sequence) |
71e330b5 DC |
1654 | { |
1655 | struct xfs_cil *cil = log->l_cilp; | |
1656 | struct xfs_cil_ctx *ctx; | |
1657 | xfs_lsn_t commit_lsn = NULLCOMMITLSN; | |
1658 | ||
a44f13ed DC |
1659 | ASSERT(sequence <= cil->xc_current_sequence); |
1660 | ||
0020a190 DC |
1661 | if (!sequence) |
1662 | sequence = cil->xc_current_sequence; | |
1663 | trace_xfs_log_force(log->l_mp, sequence, _RET_IP_); | |
1664 | ||
a44f13ed DC |
1665 | /* |
1666 | * check to see if we need to force out the current context. | |
1667 | * xlog_cil_push() handles racing pushes for the same sequence, | |
1668 | * so no need to deal with it here. | |
1669 | */ | |
f876e446 | 1670 | restart: |
0020a190 | 1671 | xlog_cil_push_now(log, sequence, false); |
71e330b5 DC |
1672 | |
1673 | /* | |
1674 | * See if we can find a previous sequence still committing. | |
71e330b5 DC |
1675 | * We need to wait for all previous sequence commits to complete |
1676 | * before allowing the force of push_seq to go ahead. Hence block | |
1677 | * on commits for those as well. | |
1678 | */ | |
4bb928cd | 1679 | spin_lock(&cil->xc_push_lock); |
71e330b5 | 1680 | list_for_each_entry(ctx, &cil->xc_committing, committing) { |
ac983517 DC |
1681 | /* |
1682 | * Avoid getting stuck in this loop because we were woken by the | |
1683 | * shutdown, but then went back to sleep once already in the | |
1684 | * shutdown state. | |
1685 | */ | |
2039a272 | 1686 | if (xlog_is_shutdown(log)) |
ac983517 | 1687 | goto out_shutdown; |
a44f13ed | 1688 | if (ctx->sequence > sequence) |
71e330b5 DC |
1689 | continue; |
1690 | if (!ctx->commit_lsn) { | |
1691 | /* | |
1692 | * It is still being pushed! Wait for the push to | |
1693 | * complete, then start again from the beginning. | |
1694 | */ | |
0020a190 | 1695 | XFS_STATS_INC(log->l_mp, xs_log_force_sleep); |
4bb928cd | 1696 | xlog_wait(&cil->xc_commit_wait, &cil->xc_push_lock); |
71e330b5 DC |
1697 | goto restart; |
1698 | } | |
a44f13ed | 1699 | if (ctx->sequence != sequence) |
71e330b5 DC |
1700 | continue; |
1701 | /* found it! */ | |
1702 | commit_lsn = ctx->commit_lsn; | |
1703 | } | |
f876e446 DC |
1704 | |
1705 | /* | |
1706 | * The call to xlog_cil_push_now() executes the push in the background. | |
1707 | * Hence by the time we have got here it our sequence may not have been | |
1708 | * pushed yet. This is true if the current sequence still matches the | |
1709 | * push sequence after the above wait loop and the CIL still contains | |
8af3dcd3 DC |
1710 | * dirty objects. This is guaranteed by the push code first adding the |
1711 | * context to the committing list before emptying the CIL. | |
f876e446 | 1712 | * |
8af3dcd3 DC |
1713 | * Hence if we don't find the context in the committing list and the |
1714 | * current sequence number is unchanged then the CIL contents are | |
1715 | * significant. If the CIL is empty, if means there was nothing to push | |
1716 | * and that means there is nothing to wait for. If the CIL is not empty, | |
1717 | * it means we haven't yet started the push, because if it had started | |
1718 | * we would have found the context on the committing list. | |
f876e446 | 1719 | */ |
f876e446 | 1720 | if (sequence == cil->xc_current_sequence && |
88591e7f | 1721 | !test_bit(XLOG_CIL_EMPTY, &cil->xc_flags)) { |
f876e446 DC |
1722 | spin_unlock(&cil->xc_push_lock); |
1723 | goto restart; | |
1724 | } | |
1725 | ||
4bb928cd | 1726 | spin_unlock(&cil->xc_push_lock); |
71e330b5 | 1727 | return commit_lsn; |
ac983517 DC |
1728 | |
1729 | /* | |
1730 | * We detected a shutdown in progress. We need to trigger the log force | |
1731 | * to pass through it's iclog state machine error handling, even though | |
1732 | * we are already in a shutdown state. Hence we can't return | |
1733 | * NULLCOMMITLSN here as that has special meaning to log forces (i.e. | |
1734 | * LSN is already stable), so we return a zero LSN instead. | |
1735 | */ | |
1736 | out_shutdown: | |
1737 | spin_unlock(&cil->xc_push_lock); | |
1738 | return 0; | |
71e330b5 | 1739 | } |
ccf7c23f | 1740 | |
af1c2146 DC |
1741 | /* |
1742 | * Move dead percpu state to the relevant CIL context structures. | |
1743 | * | |
1744 | * We have to lock the CIL context here to ensure that nothing is modifying | |
1745 | * the percpu state, either addition or removal. Both of these are done under | |
1746 | * the CIL context lock, so grabbing that exclusively here will ensure we can | |
1747 | * safely drain the cilpcp for the CPU that is dying. | |
1748 | */ | |
1749 | void | |
1750 | xlog_cil_pcp_dead( | |
1751 | struct xlog *log, | |
1752 | unsigned int cpu) | |
1753 | { | |
1754 | struct xfs_cil *cil = log->l_cilp; | |
7c8ade21 | 1755 | struct xlog_cil_pcp *cilpcp = per_cpu_ptr(cil->xc_pcp, cpu); |
1dd2a2c1 | 1756 | struct xfs_cil_ctx *ctx; |
af1c2146 DC |
1757 | |
1758 | down_write(&cil->xc_ctx_lock); | |
1dd2a2c1 DC |
1759 | ctx = cil->xc_ctx; |
1760 | if (ctx->ticket) | |
1761 | ctx->ticket->t_curr_res += cilpcp->space_reserved; | |
1762 | cilpcp->space_reserved = 0; | |
1763 | ||
df7a4a21 DC |
1764 | if (!list_empty(&cilpcp->busy_extents)) |
1765 | list_splice_init(&cilpcp->busy_extents, &ctx->busy_extents); | |
1dd2a2c1 | 1766 | atomic_add(cilpcp->space_used, &ctx->space_used); |
7c8ade21 | 1767 | cilpcp->space_used = 0; |
af1c2146 DC |
1768 | up_write(&cil->xc_ctx_lock); |
1769 | } | |
1770 | ||
4c2d542f DC |
1771 | /* |
1772 | * Perform initial CIL structure initialisation. | |
1773 | */ | |
1774 | int | |
1775 | xlog_cil_init( | |
df7a4a21 | 1776 | struct xlog *log) |
4c2d542f | 1777 | { |
df7a4a21 DC |
1778 | struct xfs_cil *cil; |
1779 | struct xfs_cil_ctx *ctx; | |
1780 | struct xlog_cil_pcp *cilpcp; | |
1781 | int cpu; | |
4c2d542f | 1782 | |
707e0dda | 1783 | cil = kmem_zalloc(sizeof(*cil), KM_MAYFAIL); |
4c2d542f | 1784 | if (!cil) |
2451337d | 1785 | return -ENOMEM; |
33c0dd78 DC |
1786 | /* |
1787 | * Limit the CIL pipeline depth to 4 concurrent works to bound the | |
1788 | * concurrency the log spinlocks will be exposed to. | |
1789 | */ | |
1790 | cil->xc_push_wq = alloc_workqueue("xfs-cil/%s", | |
1791 | XFS_WQFLAGS(WQ_FREEZABLE | WQ_MEM_RECLAIM | WQ_UNBOUND), | |
1792 | 4, log->l_mp->m_super->s_id); | |
1793 | if (!cil->xc_push_wq) | |
1794 | goto out_destroy_cil; | |
4c2d542f | 1795 | |
af1c2146 DC |
1796 | cil->xc_log = log; |
1797 | cil->xc_pcp = alloc_percpu(struct xlog_cil_pcp); | |
1798 | if (!cil->xc_pcp) | |
1799 | goto out_destroy_wq; | |
1800 | ||
df7a4a21 DC |
1801 | for_each_possible_cpu(cpu) { |
1802 | cilpcp = per_cpu_ptr(cil->xc_pcp, cpu); | |
1803 | INIT_LIST_HEAD(&cilpcp->busy_extents); | |
1804 | } | |
1805 | ||
4c2d542f DC |
1806 | INIT_LIST_HEAD(&cil->xc_cil); |
1807 | INIT_LIST_HEAD(&cil->xc_committing); | |
1808 | spin_lock_init(&cil->xc_cil_lock); | |
4bb928cd | 1809 | spin_lock_init(&cil->xc_push_lock); |
c7f87f39 | 1810 | init_waitqueue_head(&cil->xc_push_wait); |
4c2d542f | 1811 | init_rwsem(&cil->xc_ctx_lock); |
68a74dca | 1812 | init_waitqueue_head(&cil->xc_start_wait); |
4c2d542f | 1813 | init_waitqueue_head(&cil->xc_commit_wait); |
4c2d542f | 1814 | log->l_cilp = cil; |
39823d0f DC |
1815 | |
1816 | ctx = xlog_cil_ctx_alloc(); | |
1817 | xlog_cil_ctx_switch(cil, ctx); | |
4c2d542f | 1818 | return 0; |
33c0dd78 | 1819 | |
af1c2146 DC |
1820 | out_destroy_wq: |
1821 | destroy_workqueue(cil->xc_push_wq); | |
33c0dd78 DC |
1822 | out_destroy_cil: |
1823 | kmem_free(cil); | |
1824 | return -ENOMEM; | |
4c2d542f DC |
1825 | } |
1826 | ||
1827 | void | |
1828 | xlog_cil_destroy( | |
f7bdf03a | 1829 | struct xlog *log) |
4c2d542f | 1830 | { |
88591e7f DC |
1831 | struct xfs_cil *cil = log->l_cilp; |
1832 | ||
1833 | if (cil->xc_ctx) { | |
1834 | if (cil->xc_ctx->ticket) | |
1835 | xfs_log_ticket_put(cil->xc_ctx->ticket); | |
1836 | kmem_free(cil->xc_ctx); | |
4c2d542f DC |
1837 | } |
1838 | ||
88591e7f DC |
1839 | ASSERT(list_empty(&cil->xc_cil)); |
1840 | ASSERT(test_bit(XLOG_CIL_EMPTY, &cil->xc_flags)); | |
af1c2146 | 1841 | free_percpu(cil->xc_pcp); |
88591e7f DC |
1842 | destroy_workqueue(cil->xc_push_wq); |
1843 | kmem_free(cil); | |
4c2d542f DC |
1844 | } |
1845 |