blob: cdebd832c3dba1fcd937869d1cedcebe09113c25 [file] [log] [blame]
Dave Chinner71e330b2010-05-21 14:37:18 +10001/*
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"
Dave Chinner239880e2013-10-23 10:50:10 +110020#include "xfs_log_format.h"
Dave Chinner70a9883c2013-10-23 10:36:05 +110021#include "xfs_shared.h"
Dave Chinner239880e2013-10-23 10:50:10 +110022#include "xfs_trans_resv.h"
Dave Chinner71e330b2010-05-21 14:37:18 +100023#include "xfs_sb.h"
24#include "xfs_ag.h"
Dave Chinner71e330b2010-05-21 14:37:18 +100025#include "xfs_mount.h"
26#include "xfs_error.h"
27#include "xfs_alloc.h"
Dave Chinnerefc27b52012-04-29 10:39:43 +000028#include "xfs_extent_busy.h"
Christoph Hellwige84661a2011-05-20 13:45:32 +000029#include "xfs_discard.h"
Dave Chinner239880e2013-10-23 10:50:10 +110030#include "xfs_trans.h"
31#include "xfs_trans_priv.h"
32#include "xfs_log.h"
33#include "xfs_log_priv.h"
Dave Chinner71e330b2010-05-21 14:37:18 +100034
35/*
Dave Chinner71e330b2010-05-21 14:37:18 +100036 * Allocate a new ticket. Failing to get a new ticket makes it really hard to
37 * recover, so we don't allow failure here. Also, we allocate in a context that
38 * we don't want to be issuing transactions from, so we need to tell the
39 * allocation code this as well.
40 *
41 * We don't reserve any space for the ticket - we are going to steal whatever
42 * space we require from transactions as they commit. To ensure we reserve all
43 * the space required, we need to set the current reservation of the ticket to
44 * zero so that we know to steal the initial transaction overhead from the
45 * first transaction commit.
46 */
47static struct xlog_ticket *
48xlog_cil_ticket_alloc(
Mark Tinguelyf7bdf032012-06-14 09:22:15 -050049 struct xlog *log)
Dave Chinner71e330b2010-05-21 14:37:18 +100050{
51 struct xlog_ticket *tic;
52
53 tic = xlog_ticket_alloc(log, 0, 1, XFS_TRANSACTION, 0,
54 KM_SLEEP|KM_NOFS);
55 tic->t_trans_type = XFS_TRANS_CHECKPOINT;
56
57 /*
58 * set the current reservation to zero so we know to steal the basic
59 * transaction overhead reservation from the first transaction commit.
60 */
61 tic->t_curr_res = 0;
62 return tic;
63}
64
65/*
66 * After the first stage of log recovery is done, we know where the head and
67 * tail of the log are. We need this log initialisation done before we can
68 * initialise the first CIL checkpoint context.
69 *
70 * Here we allocate a log ticket to track space usage during a CIL push. This
71 * ticket is passed to xlog_write() directly so that we don't slowly leak log
72 * space by failing to account for space used by log headers and additional
73 * region headers for split regions.
74 */
75void
76xlog_cil_init_post_recovery(
Mark Tinguelyf7bdf032012-06-14 09:22:15 -050077 struct xlog *log)
Dave Chinner71e330b2010-05-21 14:37:18 +100078{
Dave Chinner71e330b2010-05-21 14:37:18 +100079 log->l_cilp->xc_ctx->ticket = xlog_cil_ticket_alloc(log);
80 log->l_cilp->xc_ctx->sequence = 1;
81 log->l_cilp->xc_ctx->commit_lsn = xlog_assign_lsn(log->l_curr_cycle,
82 log->l_curr_block);
83}
84
85/*
Dave Chinner991aaf62013-08-12 20:50:07 +100086 * Prepare the log item for insertion into the CIL. Calculate the difference in
87 * log space and vectors it will consume, and if it is a new item pin it as
88 * well.
89 */
90STATIC void
91xfs_cil_prepare_item(
92 struct xlog *log,
93 struct xfs_log_vec *lv,
94 struct xfs_log_vec *old_lv,
95 int *diff_len,
96 int *diff_iovecs)
97{
98 /* Account for the new LV being passed in */
99 if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED) {
100 *diff_len += lv->lv_buf_len;
101 *diff_iovecs += lv->lv_niovecs;
102 }
103
104 /*
105 * If there is no old LV, this is the first time we've seen the item in
106 * this CIL context and so we need to pin it. If we are replacing the
107 * old_lv, then remove the space it accounts for and free it.
108 */
109 if (!old_lv)
110 lv->lv_item->li_ops->iop_pin(lv->lv_item);
111 else if (old_lv != lv) {
112 ASSERT(lv->lv_buf_len != XFS_LOG_VEC_ORDERED);
113
114 *diff_len -= old_lv->lv_buf_len;
115 *diff_iovecs -= old_lv->lv_niovecs;
116 kmem_free(old_lv);
117 }
118
119 /* attach new log vector to log item */
120 lv->lv_item->li_lv = lv;
121
122 /*
123 * If this is the first time the item is being committed to the
124 * CIL, store the sequence number on the log item so we can
125 * tell in future commits whether this is the first checkpoint
126 * the item is being committed into.
127 */
128 if (!lv->lv_item->li_seq)
129 lv->lv_item->li_seq = log->l_cilp->xc_ctx->sequence;
130}
131
132/*
Dave Chinner71e330b2010-05-21 14:37:18 +1000133 * Format log item into a flat buffers
134 *
135 * For delayed logging, we need to hold a formatted buffer containing all the
136 * changes on the log item. This enables us to relog the item in memory and
137 * write it out asynchronously without needing to relock the object that was
138 * modified at the time it gets written into the iclog.
139 *
140 * This function builds a vector for the changes in each log item in the
141 * transaction. It then works out the length of the buffer needed for each log
142 * item, allocates them and formats the vector for the item into the buffer.
143 * The buffer is then attached to the log item are then inserted into the
144 * Committed Item List for tracking until the next checkpoint is written out.
145 *
146 * We don't set up region headers during this process; we simply copy the
147 * regions into the flat buffer. We can do this because we still have to do a
148 * formatting step to write the regions into the iclog buffer. Writing the
149 * ophdrs during the iclog write means that we can support splitting large
150 * regions across iclog boundares without needing a change in the format of the
151 * item/region encapsulation.
152 *
153 * Hence what we need to do now is change the rewrite the vector array to point
154 * to the copied region inside the buffer we just allocated. This allows us to
155 * format the regions into the iclog as though they are being formatted
156 * directly out of the objects themselves.
157 */
Dave Chinner991aaf62013-08-12 20:50:07 +1000158static void
159xlog_cil_insert_format_items(
160 struct xlog *log,
161 struct xfs_trans *tp,
162 int *diff_len,
163 int *diff_iovecs)
Dave Chinner71e330b2010-05-21 14:37:18 +1000164{
Christoph Hellwig0244b962011-12-06 21:58:08 +0000165 struct xfs_log_item_desc *lidp;
Dave Chinner71e330b2010-05-21 14:37:18 +1000166
Christoph Hellwig0244b962011-12-06 21:58:08 +0000167
168 /* Bail out if we didn't find a log item. */
169 if (list_empty(&tp->t_items)) {
170 ASSERT(0);
Dave Chinner991aaf62013-08-12 20:50:07 +1000171 return;
Christoph Hellwig0244b962011-12-06 21:58:08 +0000172 }
173
174 list_for_each_entry(lidp, &tp->t_items, lid_trans) {
Dave Chinner166d1362013-08-12 20:50:04 +1000175 struct xfs_log_item *lip = lidp->lid_item;
Dave Chinner7492c5b2013-08-12 20:50:05 +1000176 struct xfs_log_vec *lv;
Dave Chinner991aaf62013-08-12 20:50:07 +1000177 struct xfs_log_vec *old_lv;
Dave Chinner7492c5b2013-08-12 20:50:05 +1000178 int niovecs = 0;
179 int nbytes = 0;
180 int buf_size;
Dave Chinnerfd638752013-06-27 16:04:51 +1000181 bool ordered = false;
Dave Chinner71e330b2010-05-21 14:37:18 +1000182
Christoph Hellwig0244b962011-12-06 21:58:08 +0000183 /* Skip items which aren't dirty in this transaction. */
184 if (!(lidp->lid_flags & XFS_LID_DIRTY))
185 continue;
186
Dave Chinner166d1362013-08-12 20:50:04 +1000187 /* get number of vecs and size of data to be stored */
188 lip->li_ops->iop_size(lip, &niovecs, &nbytes);
189
Christoph Hellwig0244b962011-12-06 21:58:08 +0000190 /* Skip items that do not have any vectors for writing */
Christoph Hellwigb3934212011-12-06 21:58:09 +0000191 if (!niovecs)
Christoph Hellwig0244b962011-12-06 21:58:08 +0000192 continue;
193
Dave Chinnerfd638752013-06-27 16:04:51 +1000194 /*
195 * Ordered items need to be tracked but we do not wish to write
196 * them. We need a logvec to track the object, but we do not
197 * need an iovec or buffer to be allocated for copying data.
198 */
199 if (niovecs == XFS_LOG_VEC_ORDERED) {
200 ordered = true;
201 niovecs = 0;
Dave Chinner7492c5b2013-08-12 20:50:05 +1000202 nbytes = 0;
Dave Chinnerfd638752013-06-27 16:04:51 +1000203 }
204
Christoph Hellwigbde7cff2013-12-13 11:34:02 +1100205 /*
206 * We 64-bit align the length of each iovec so that the start
207 * of the next one is naturally aligned. We'll need to
208 * account for that slack space here.
209 */
210 nbytes += niovecs * sizeof(uint64_t);
211
Dave Chinner991aaf62013-08-12 20:50:07 +1000212 /* grab the old item if it exists for reservation accounting */
213 old_lv = lip->li_lv;
214
Dave Chinner7492c5b2013-08-12 20:50:05 +1000215 /* calc buffer size */
216 buf_size = sizeof(struct xfs_log_vec) + nbytes +
217 niovecs * sizeof(struct xfs_log_iovec);
Christoph Hellwig0244b962011-12-06 21:58:08 +0000218
Dave Chinnerf5baac32013-08-12 20:50:06 +1000219 /* compare to existing item size */
220 if (lip->li_lv && buf_size <= lip->li_lv->lv_size) {
221 /* same or smaller, optimise common overwrite case */
222 lv = lip->li_lv;
223 lv->lv_next = NULL;
224
225 if (ordered)
226 goto insert;
227
Dave Chinner991aaf62013-08-12 20:50:07 +1000228 /*
229 * set the item up as though it is a new insertion so
230 * that the space reservation accounting is correct.
231 */
232 *diff_iovecs -= lv->lv_niovecs;
233 *diff_len -= lv->lv_buf_len;
Christoph Hellwig9597df62013-12-13 11:00:42 +1100234 } else {
235 /* allocate new data chunk */
236 lv = kmem_zalloc(buf_size, KM_SLEEP|KM_NOFS);
237 lv->lv_item = lip;
238 lv->lv_size = buf_size;
239 if (ordered) {
240 /* track as an ordered logvec */
241 ASSERT(lip->li_lv == NULL);
242 lv->lv_buf_len = XFS_LOG_VEC_ORDERED;
243 goto insert;
244 }
245 lv->lv_iovecp = (struct xfs_log_iovec *)&lv[1];
Dave Chinnerf5baac32013-08-12 20:50:06 +1000246 }
247
Christoph Hellwig9597df62013-12-13 11:00:42 +1100248 /* Ensure the lv is set up according to ->iop_size */
Dave Chinner7492c5b2013-08-12 20:50:05 +1000249 lv->lv_niovecs = niovecs;
Christoph Hellwig0244b962011-12-06 21:58:08 +0000250
Dave Chinner7492c5b2013-08-12 20:50:05 +1000251 /* The allocated data region lies beyond the iovec region */
Christoph Hellwigbde7cff2013-12-13 11:34:02 +1100252 lv->lv_buf_len = 0;
Dave Chinner7492c5b2013-08-12 20:50:05 +1000253 lv->lv_buf = (char *)lv + buf_size - nbytes;
Christoph Hellwigbde7cff2013-12-13 11:34:02 +1100254 lip->li_ops->iop_format(lip, lv);
Dave Chinner7492c5b2013-08-12 20:50:05 +1000255insert:
Dave Chinnerf5baac32013-08-12 20:50:06 +1000256 ASSERT(lv->lv_buf_len <= nbytes);
Dave Chinner991aaf62013-08-12 20:50:07 +1000257 xfs_cil_prepare_item(log, lv, old_lv, diff_len, diff_iovecs);
Dave Chinner71e330b2010-05-21 14:37:18 +1000258 }
Dave Chinnerd1583a32010-09-24 18:14:13 +1000259}
260
261/*
262 * Insert the log items into the CIL and calculate the difference in space
263 * consumed by the item. Add the space to the checkpoint ticket and calculate
264 * if the change requires additional log metadata. If it does, take that space
Justin P. Mattock42b2aa82011-11-28 20:31:00 -0800265 * as well. Remove the amount of space we added to the checkpoint ticket from
Dave Chinnerd1583a32010-09-24 18:14:13 +1000266 * the current transaction ticket so that the accounting works out correctly.
267 */
Dave Chinner71e330b2010-05-21 14:37:18 +1000268static void
Dave Chinner3b93c7a2010-08-24 11:45:53 +1000269xlog_cil_insert_items(
Mark Tinguelyf7bdf032012-06-14 09:22:15 -0500270 struct xlog *log,
Dave Chinner991aaf62013-08-12 20:50:07 +1000271 struct xfs_trans *tp)
Dave Chinner3b93c7a2010-08-24 11:45:53 +1000272{
Dave Chinnerd1583a32010-09-24 18:14:13 +1000273 struct xfs_cil *cil = log->l_cilp;
274 struct xfs_cil_ctx *ctx = cil->xc_ctx;
Dave Chinner991aaf62013-08-12 20:50:07 +1000275 struct xfs_log_item_desc *lidp;
Dave Chinnerd1583a32010-09-24 18:14:13 +1000276 int len = 0;
277 int diff_iovecs = 0;
278 int iclog_space;
Dave Chinner3b93c7a2010-08-24 11:45:53 +1000279
Dave Chinner991aaf62013-08-12 20:50:07 +1000280 ASSERT(tp);
Dave Chinnerd1583a32010-09-24 18:14:13 +1000281
282 /*
Dave Chinnerd1583a32010-09-24 18:14:13 +1000283 * We can do this safely because the context can't checkpoint until we
284 * are done so it doesn't matter exactly how we update the CIL.
285 */
Dave Chinner991aaf62013-08-12 20:50:07 +1000286 xlog_cil_insert_format_items(log, tp, &len, &diff_iovecs);
287
288 /*
289 * Now (re-)position everything modified at the tail of the CIL.
290 * We do this here so we only need to take the CIL lock once during
291 * the transaction commit.
292 */
Dave Chinnerfd638752013-06-27 16:04:51 +1000293 spin_lock(&cil->xc_cil_lock);
Dave Chinner991aaf62013-08-12 20:50:07 +1000294 list_for_each_entry(lidp, &tp->t_items, lid_trans) {
295 struct xfs_log_item *lip = lidp->lid_item;
Dave Chinnerfd638752013-06-27 16:04:51 +1000296
Dave Chinner991aaf62013-08-12 20:50:07 +1000297 /* Skip items which aren't dirty in this transaction. */
298 if (!(lidp->lid_flags & XFS_LID_DIRTY))
299 continue;
Dave Chinnerfd638752013-06-27 16:04:51 +1000300
Dave Chinner991aaf62013-08-12 20:50:07 +1000301 list_move_tail(&lip->li_cil, &cil->xc_cil);
Dave Chinnerfd638752013-06-27 16:04:51 +1000302 }
Dave Chinnerd1583a32010-09-24 18:14:13 +1000303
304 /* account for space used by new iovec headers */
305 len += diff_iovecs * sizeof(xlog_op_header_t);
Dave Chinnerd1583a32010-09-24 18:14:13 +1000306 ctx->nvecs += diff_iovecs;
307
Dave Chinner991aaf62013-08-12 20:50:07 +1000308 /* attach the transaction to the CIL if it has any busy extents */
309 if (!list_empty(&tp->t_busy))
310 list_splice_init(&tp->t_busy, &ctx->busy_extents);
311
Dave Chinnerd1583a32010-09-24 18:14:13 +1000312 /*
313 * Now transfer enough transaction reservation to the context ticket
314 * for the checkpoint. The context ticket is special - the unit
315 * reservation has to grow as well as the current reservation as we
316 * steal from tickets so we can correctly determine the space used
317 * during the transaction commit.
318 */
319 if (ctx->ticket->t_curr_res == 0) {
Dave Chinnerd1583a32010-09-24 18:14:13 +1000320 ctx->ticket->t_curr_res = ctx->ticket->t_unit_res;
Dave Chinner991aaf62013-08-12 20:50:07 +1000321 tp->t_ticket->t_curr_res -= ctx->ticket->t_unit_res;
Dave Chinnerd1583a32010-09-24 18:14:13 +1000322 }
323
324 /* do we need space for more log record headers? */
325 iclog_space = log->l_iclog_size - log->l_iclog_hsize;
326 if (len > 0 && (ctx->space_used / iclog_space !=
327 (ctx->space_used + len) / iclog_space)) {
328 int hdrs;
329
330 hdrs = (len + iclog_space - 1) / iclog_space;
331 /* need to take into account split region headers, too */
332 hdrs *= log->l_iclog_hsize + sizeof(struct xlog_op_header);
333 ctx->ticket->t_unit_res += hdrs;
334 ctx->ticket->t_curr_res += hdrs;
Dave Chinner991aaf62013-08-12 20:50:07 +1000335 tp->t_ticket->t_curr_res -= hdrs;
336 ASSERT(tp->t_ticket->t_curr_res >= len);
Dave Chinnerd1583a32010-09-24 18:14:13 +1000337 }
Dave Chinner991aaf62013-08-12 20:50:07 +1000338 tp->t_ticket->t_curr_res -= len;
Dave Chinnerd1583a32010-09-24 18:14:13 +1000339 ctx->space_used += len;
340
341 spin_unlock(&cil->xc_cil_lock);
Dave Chinner3b93c7a2010-08-24 11:45:53 +1000342}
343
344static void
Dave Chinner71e330b2010-05-21 14:37:18 +1000345xlog_cil_free_logvec(
346 struct xfs_log_vec *log_vector)
347{
348 struct xfs_log_vec *lv;
349
350 for (lv = log_vector; lv; ) {
351 struct xfs_log_vec *next = lv->lv_next;
Dave Chinner71e330b2010-05-21 14:37:18 +1000352 kmem_free(lv);
353 lv = next;
354 }
355}
356
357/*
Dave Chinner71e330b2010-05-21 14:37:18 +1000358 * Mark all items committed and clear busy extents. We free the log vector
359 * chains in a separate pass so that we unpin the log items as quickly as
360 * possible.
361 */
362static void
363xlog_cil_committed(
364 void *args,
365 int abort)
366{
367 struct xfs_cil_ctx *ctx = args;
Christoph Hellwige84661a2011-05-20 13:45:32 +0000368 struct xfs_mount *mp = ctx->cil->xc_log->l_mp;
Dave Chinner71e330b2010-05-21 14:37:18 +1000369
Dave Chinner0e57f6a2010-12-20 12:02:19 +1100370 xfs_trans_committed_bulk(ctx->cil->xc_log->l_ailp, ctx->lv_chain,
371 ctx->start_lsn, abort);
Dave Chinner71e330b2010-05-21 14:37:18 +1000372
Dave Chinner4ecbfe62012-04-29 10:41:10 +0000373 xfs_extent_busy_sort(&ctx->busy_extents);
374 xfs_extent_busy_clear(mp, &ctx->busy_extents,
Christoph Hellwige84661a2011-05-20 13:45:32 +0000375 (mp->m_flags & XFS_MOUNT_DISCARD) && !abort);
Dave Chinner71e330b2010-05-21 14:37:18 +1000376
Dave Chinner4bb928c2013-08-12 20:50:08 +1000377 spin_lock(&ctx->cil->xc_push_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000378 list_del(&ctx->committing);
Dave Chinner4bb928c2013-08-12 20:50:08 +1000379 spin_unlock(&ctx->cil->xc_push_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000380
381 xlog_cil_free_logvec(ctx->lv_chain);
Christoph Hellwige84661a2011-05-20 13:45:32 +0000382
383 if (!list_empty(&ctx->busy_extents)) {
384 ASSERT(mp->m_flags & XFS_MOUNT_DISCARD);
385
386 xfs_discard_extents(mp, &ctx->busy_extents);
Dave Chinner4ecbfe62012-04-29 10:41:10 +0000387 xfs_extent_busy_clear(mp, &ctx->busy_extents, false);
Christoph Hellwige84661a2011-05-20 13:45:32 +0000388 }
389
Dave Chinner71e330b2010-05-21 14:37:18 +1000390 kmem_free(ctx);
391}
392
393/*
Dave Chinnera44f13e2010-08-24 11:40:03 +1000394 * Push the Committed Item List to the log. If @push_seq flag is zero, then it
395 * is a background flush and so we can chose to ignore it. Otherwise, if the
396 * current sequence is the same as @push_seq we need to do a flush. If
397 * @push_seq is less than the current sequence, then it has already been
398 * flushed and we don't need to do anything - the caller will wait for it to
399 * complete if necessary.
400 *
401 * @push_seq is a value rather than a flag because that allows us to do an
402 * unlocked check of the sequence number for a match. Hence we can allows log
403 * forces to run racily and not issue pushes for the same sequence twice. If we
404 * get a race between multiple pushes for the same sequence they will block on
405 * the first one and then abort, hence avoiding needless pushes.
Dave Chinner71e330b2010-05-21 14:37:18 +1000406 */
Dave Chinnera44f13e2010-08-24 11:40:03 +1000407STATIC int
Dave Chinner71e330b2010-05-21 14:37:18 +1000408xlog_cil_push(
Mark Tinguelyf7bdf032012-06-14 09:22:15 -0500409 struct xlog *log)
Dave Chinner71e330b2010-05-21 14:37:18 +1000410{
411 struct xfs_cil *cil = log->l_cilp;
412 struct xfs_log_vec *lv;
413 struct xfs_cil_ctx *ctx;
414 struct xfs_cil_ctx *new_ctx;
415 struct xlog_in_core *commit_iclog;
416 struct xlog_ticket *tic;
Dave Chinner71e330b2010-05-21 14:37:18 +1000417 int num_iovecs;
Dave Chinner71e330b2010-05-21 14:37:18 +1000418 int error = 0;
419 struct xfs_trans_header thdr;
420 struct xfs_log_iovec lhdr;
421 struct xfs_log_vec lvhdr = { NULL };
422 xfs_lsn_t commit_lsn;
Dave Chinner4c2d5422012-04-23 17:54:32 +1000423 xfs_lsn_t push_seq;
Dave Chinner71e330b2010-05-21 14:37:18 +1000424
425 if (!cil)
426 return 0;
427
Dave Chinner71e330b2010-05-21 14:37:18 +1000428 new_ctx = kmem_zalloc(sizeof(*new_ctx), KM_SLEEP|KM_NOFS);
429 new_ctx->ticket = xlog_cil_ticket_alloc(log);
430
Dave Chinner4c2d5422012-04-23 17:54:32 +1000431 down_write(&cil->xc_ctx_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000432 ctx = cil->xc_ctx;
433
Dave Chinner4bb928c2013-08-12 20:50:08 +1000434 spin_lock(&cil->xc_push_lock);
Dave Chinner4c2d5422012-04-23 17:54:32 +1000435 push_seq = cil->xc_push_seq;
436 ASSERT(push_seq <= ctx->sequence);
Dave Chinner71e330b2010-05-21 14:37:18 +1000437
Dave Chinner4c2d5422012-04-23 17:54:32 +1000438 /*
439 * Check if we've anything to push. If there is nothing, then we don't
440 * move on to a new sequence number and so we have to be able to push
441 * this sequence again later.
442 */
443 if (list_empty(&cil->xc_cil)) {
444 cil->xc_push_seq = 0;
Dave Chinner4bb928c2013-08-12 20:50:08 +1000445 spin_unlock(&cil->xc_push_lock);
Dave Chinnera44f13e2010-08-24 11:40:03 +1000446 goto out_skip;
Dave Chinner4c2d5422012-04-23 17:54:32 +1000447 }
Dave Chinner4bb928c2013-08-12 20:50:08 +1000448 spin_unlock(&cil->xc_push_lock);
Dave Chinner4c2d5422012-04-23 17:54:32 +1000449
Dave Chinnera44f13e2010-08-24 11:40:03 +1000450
451 /* check for a previously pushed seqeunce */
Dave Chinner4c2d5422012-04-23 17:54:32 +1000452 if (push_seq < cil->xc_ctx->sequence)
Dave Chinnerdf806152010-05-17 15:52:13 +1000453 goto out_skip;
454
Dave Chinner71e330b2010-05-21 14:37:18 +1000455 /*
456 * pull all the log vectors off the items in the CIL, and
457 * remove the items from the CIL. We don't need the CIL lock
458 * here because it's only needed on the transaction commit
459 * side which is currently locked out by the flush lock.
460 */
461 lv = NULL;
Dave Chinner71e330b2010-05-21 14:37:18 +1000462 num_iovecs = 0;
Dave Chinner71e330b2010-05-21 14:37:18 +1000463 while (!list_empty(&cil->xc_cil)) {
464 struct xfs_log_item *item;
Dave Chinner71e330b2010-05-21 14:37:18 +1000465
466 item = list_first_entry(&cil->xc_cil,
467 struct xfs_log_item, li_cil);
468 list_del_init(&item->li_cil);
469 if (!ctx->lv_chain)
470 ctx->lv_chain = item->li_lv;
471 else
472 lv->lv_next = item->li_lv;
473 lv = item->li_lv;
474 item->li_lv = NULL;
Dave Chinner71e330b2010-05-21 14:37:18 +1000475 num_iovecs += lv->lv_niovecs;
Dave Chinner71e330b2010-05-21 14:37:18 +1000476 }
477
478 /*
479 * initialise the new context and attach it to the CIL. Then attach
480 * the current context to the CIL committing lsit so it can be found
481 * during log forces to extract the commit lsn of the sequence that
482 * needs to be forced.
483 */
484 INIT_LIST_HEAD(&new_ctx->committing);
485 INIT_LIST_HEAD(&new_ctx->busy_extents);
486 new_ctx->sequence = ctx->sequence + 1;
487 new_ctx->cil = cil;
488 cil->xc_ctx = new_ctx;
489
490 /*
Dave Chinnera44f13e2010-08-24 11:40:03 +1000491 * mirror the new sequence into the cil structure so that we can do
492 * unlocked checks against the current sequence in log forces without
493 * risking deferencing a freed context pointer.
494 */
495 cil->xc_current_sequence = new_ctx->sequence;
496
497 /*
Dave Chinner71e330b2010-05-21 14:37:18 +1000498 * The switch is now done, so we can drop the context lock and move out
499 * of a shared context. We can't just go straight to the commit record,
500 * though - we need to synchronise with previous and future commits so
501 * that the commit records are correctly ordered in the log to ensure
502 * that we process items during log IO completion in the correct order.
503 *
504 * For example, if we get an EFI in one checkpoint and the EFD in the
505 * next (e.g. due to log forces), we do not want the checkpoint with
506 * the EFD to be committed before the checkpoint with the EFI. Hence
507 * we must strictly order the commit records of the checkpoints so
508 * that: a) the checkpoint callbacks are attached to the iclogs in the
509 * correct order; and b) the checkpoints are replayed in correct order
510 * in log recovery.
511 *
512 * Hence we need to add this context to the committing context list so
513 * that higher sequences will wait for us to write out a commit record
514 * before they do.
515 */
Dave Chinner4bb928c2013-08-12 20:50:08 +1000516 spin_lock(&cil->xc_push_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000517 list_add(&ctx->committing, &cil->xc_committing);
Dave Chinner4bb928c2013-08-12 20:50:08 +1000518 spin_unlock(&cil->xc_push_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000519 up_write(&cil->xc_ctx_lock);
520
521 /*
522 * Build a checkpoint transaction header and write it to the log to
523 * begin the transaction. We need to account for the space used by the
524 * transaction header here as it is not accounted for in xlog_write().
525 *
526 * The LSN we need to pass to the log items on transaction commit is
527 * the LSN reported by the first log vector write. If we use the commit
528 * record lsn then we can move the tail beyond the grant write head.
529 */
530 tic = ctx->ticket;
531 thdr.th_magic = XFS_TRANS_HEADER_MAGIC;
532 thdr.th_type = XFS_TRANS_CHECKPOINT;
533 thdr.th_tid = tic->t_tid;
534 thdr.th_num_items = num_iovecs;
Christoph Hellwig4e0d5f92010-06-23 18:11:15 +1000535 lhdr.i_addr = &thdr;
Dave Chinner71e330b2010-05-21 14:37:18 +1000536 lhdr.i_len = sizeof(xfs_trans_header_t);
537 lhdr.i_type = XLOG_REG_TYPE_TRANSHDR;
538 tic->t_curr_res -= lhdr.i_len + sizeof(xlog_op_header_t);
539
540 lvhdr.lv_niovecs = 1;
541 lvhdr.lv_iovecp = &lhdr;
542 lvhdr.lv_next = ctx->lv_chain;
543
544 error = xlog_write(log, &lvhdr, tic, &ctx->start_lsn, NULL, 0);
545 if (error)
Dave Chinner7db37c52011-01-27 12:02:00 +1100546 goto out_abort_free_ticket;
Dave Chinner71e330b2010-05-21 14:37:18 +1000547
548 /*
549 * now that we've written the checkpoint into the log, strictly
550 * order the commit records so replay will get them in the right order.
551 */
552restart:
Dave Chinner4bb928c2013-08-12 20:50:08 +1000553 spin_lock(&cil->xc_push_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000554 list_for_each_entry(new_ctx, &cil->xc_committing, committing) {
555 /*
556 * Higher sequences will wait for this one so skip them.
557 * Don't wait for own own sequence, either.
558 */
559 if (new_ctx->sequence >= ctx->sequence)
560 continue;
561 if (!new_ctx->commit_lsn) {
562 /*
563 * It is still being pushed! Wait for the push to
564 * complete, then start again from the beginning.
565 */
Dave Chinner4bb928c2013-08-12 20:50:08 +1000566 xlog_wait(&cil->xc_commit_wait, &cil->xc_push_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000567 goto restart;
568 }
569 }
Dave Chinner4bb928c2013-08-12 20:50:08 +1000570 spin_unlock(&cil->xc_push_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000571
Dave Chinner7db37c52011-01-27 12:02:00 +1100572 /* xfs_log_done always frees the ticket on error. */
Dave Chinner71e330b2010-05-21 14:37:18 +1000573 commit_lsn = xfs_log_done(log->l_mp, tic, &commit_iclog, 0);
Dave Chinner7db37c52011-01-27 12:02:00 +1100574 if (commit_lsn == -1)
Dave Chinner71e330b2010-05-21 14:37:18 +1000575 goto out_abort;
576
577 /* attach all the transactions w/ busy extents to iclog */
578 ctx->log_cb.cb_func = xlog_cil_committed;
579 ctx->log_cb.cb_arg = ctx;
580 error = xfs_log_notify(log->l_mp, commit_iclog, &ctx->log_cb);
581 if (error)
582 goto out_abort;
583
584 /*
585 * now the checkpoint commit is complete and we've attached the
586 * callbacks to the iclog we can assign the commit LSN to the context
587 * and wake up anyone who is waiting for the commit to complete.
588 */
Dave Chinner4bb928c2013-08-12 20:50:08 +1000589 spin_lock(&cil->xc_push_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000590 ctx->commit_lsn = commit_lsn;
Dave Chinnereb40a872010-12-21 12:09:01 +1100591 wake_up_all(&cil->xc_commit_wait);
Dave Chinner4bb928c2013-08-12 20:50:08 +1000592 spin_unlock(&cil->xc_push_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000593
594 /* release the hounds! */
595 return xfs_log_release_iclog(log->l_mp, commit_iclog);
596
597out_skip:
598 up_write(&cil->xc_ctx_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000599 xfs_log_ticket_put(new_ctx->ticket);
600 kmem_free(new_ctx);
601 return 0;
602
Dave Chinner7db37c52011-01-27 12:02:00 +1100603out_abort_free_ticket:
604 xfs_log_ticket_put(tic);
Dave Chinner71e330b2010-05-21 14:37:18 +1000605out_abort:
606 xlog_cil_committed(ctx, XFS_LI_ABORTED);
607 return XFS_ERROR(EIO);
608}
609
Dave Chinner4c2d5422012-04-23 17:54:32 +1000610static void
611xlog_cil_push_work(
612 struct work_struct *work)
613{
614 struct xfs_cil *cil = container_of(work, struct xfs_cil,
615 xc_push_work);
616 xlog_cil_push(cil->xc_log);
617}
618
619/*
620 * We need to push CIL every so often so we don't cache more than we can fit in
621 * the log. The limit really is that a checkpoint can't be more than half the
622 * log (the current checkpoint is not allowed to overwrite the previous
623 * checkpoint), but commit latency and memory usage limit this to a smaller
624 * size.
625 */
626static void
627xlog_cil_push_background(
Mark Tinguelyf7bdf032012-06-14 09:22:15 -0500628 struct xlog *log)
Dave Chinner4c2d5422012-04-23 17:54:32 +1000629{
630 struct xfs_cil *cil = log->l_cilp;
631
632 /*
633 * The cil won't be empty because we are called while holding the
634 * context lock so whatever we added to the CIL will still be there
635 */
636 ASSERT(!list_empty(&cil->xc_cil));
637
638 /*
639 * don't do a background push if we haven't used up all the
640 * space available yet.
641 */
642 if (cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log))
643 return;
644
Dave Chinner4bb928c2013-08-12 20:50:08 +1000645 spin_lock(&cil->xc_push_lock);
Dave Chinner4c2d5422012-04-23 17:54:32 +1000646 if (cil->xc_push_seq < cil->xc_current_sequence) {
647 cil->xc_push_seq = cil->xc_current_sequence;
648 queue_work(log->l_mp->m_cil_workqueue, &cil->xc_push_work);
649 }
Dave Chinner4bb928c2013-08-12 20:50:08 +1000650 spin_unlock(&cil->xc_push_lock);
Dave Chinner4c2d5422012-04-23 17:54:32 +1000651
652}
653
654static void
655xlog_cil_push_foreground(
Mark Tinguelyf7bdf032012-06-14 09:22:15 -0500656 struct xlog *log,
Dave Chinner4c2d5422012-04-23 17:54:32 +1000657 xfs_lsn_t push_seq)
658{
659 struct xfs_cil *cil = log->l_cilp;
660
661 if (!cil)
662 return;
663
664 ASSERT(push_seq && push_seq <= cil->xc_current_sequence);
665
666 /* start on any pending background push to minimise wait time on it */
667 flush_work(&cil->xc_push_work);
668
669 /*
670 * If the CIL is empty or we've already pushed the sequence then
671 * there's no work we need to do.
672 */
Dave Chinner4bb928c2013-08-12 20:50:08 +1000673 spin_lock(&cil->xc_push_lock);
Dave Chinner4c2d5422012-04-23 17:54:32 +1000674 if (list_empty(&cil->xc_cil) || push_seq <= cil->xc_push_seq) {
Dave Chinner4bb928c2013-08-12 20:50:08 +1000675 spin_unlock(&cil->xc_push_lock);
Dave Chinner4c2d5422012-04-23 17:54:32 +1000676 return;
677 }
678
679 cil->xc_push_seq = push_seq;
Dave Chinner4bb928c2013-08-12 20:50:08 +1000680 spin_unlock(&cil->xc_push_lock);
Dave Chinner4c2d5422012-04-23 17:54:32 +1000681
682 /* do the push now */
683 xlog_cil_push(log);
684}
685
Dave Chinner2c6e24c2013-10-15 09:17:49 +1100686bool
687xlog_cil_empty(
688 struct xlog *log)
689{
690 struct xfs_cil *cil = log->l_cilp;
691 bool empty = false;
692
693 spin_lock(&cil->xc_push_lock);
694 if (list_empty(&cil->xc_cil))
695 empty = true;
696 spin_unlock(&cil->xc_push_lock);
697 return empty;
698}
699
Dave Chinner71e330b2010-05-21 14:37:18 +1000700/*
Dave Chinnera44f13e2010-08-24 11:40:03 +1000701 * Commit a transaction with the given vector to the Committed Item List.
702 *
703 * To do this, we need to format the item, pin it in memory if required and
704 * account for the space used by the transaction. Once we have done that we
705 * need to release the unused reservation for the transaction, attach the
706 * transaction to the checkpoint context so we carry the busy extents through
707 * to checkpoint completion, and then unlock all the items in the transaction.
708 *
Dave Chinnera44f13e2010-08-24 11:40:03 +1000709 * Called with the context lock already held in read mode to lock out
710 * background commit, returns without it held once background commits are
711 * allowed again.
712 */
Christoph Hellwig0244b962011-12-06 21:58:08 +0000713int
Dave Chinnera44f13e2010-08-24 11:40:03 +1000714xfs_log_commit_cil(
715 struct xfs_mount *mp,
716 struct xfs_trans *tp,
Dave Chinnera44f13e2010-08-24 11:40:03 +1000717 xfs_lsn_t *commit_lsn,
718 int flags)
719{
Mark Tinguelyf7bdf032012-06-14 09:22:15 -0500720 struct xlog *log = mp->m_log;
Dave Chinner991aaf62013-08-12 20:50:07 +1000721 struct xfs_cil *cil = log->l_cilp;
Dave Chinnera44f13e2010-08-24 11:40:03 +1000722 int log_flags = 0;
Dave Chinnera44f13e2010-08-24 11:40:03 +1000723
724 if (flags & XFS_TRANS_RELEASE_LOG_RES)
725 log_flags = XFS_LOG_REL_PERM_RESERV;
726
Dave Chinnerf5baac32013-08-12 20:50:06 +1000727 /* lock out background commit */
Dave Chinner991aaf62013-08-12 20:50:07 +1000728 down_read(&cil->xc_ctx_lock);
Dave Chinnerf5baac32013-08-12 20:50:06 +1000729
Dave Chinner991aaf62013-08-12 20:50:07 +1000730 xlog_cil_insert_items(log, tp);
Dave Chinnera44f13e2010-08-24 11:40:03 +1000731
732 /* check we didn't blow the reservation */
733 if (tp->t_ticket->t_curr_res < 0)
Dave Chinner991aaf62013-08-12 20:50:07 +1000734 xlog_print_tic_res(mp, tp->t_ticket);
Dave Chinnera44f13e2010-08-24 11:40:03 +1000735
Dave Chinner991aaf62013-08-12 20:50:07 +1000736 tp->t_commit_lsn = cil->xc_ctx->sequence;
737 if (commit_lsn)
738 *commit_lsn = tp->t_commit_lsn;
Dave Chinnera44f13e2010-08-24 11:40:03 +1000739
Dave Chinnera44f13e2010-08-24 11:40:03 +1000740 xfs_log_done(mp, tp->t_ticket, NULL, log_flags);
741 xfs_trans_unreserve_and_mod_sb(tp);
742
743 /*
744 * Once all the items of the transaction have been copied to the CIL,
745 * the items can be unlocked and freed.
746 *
747 * This needs to be done before we drop the CIL context lock because we
748 * have to update state in the log items and unlock them before they go
749 * to disk. If we don't, then the CIL checkpoint can race with us and
750 * we can run checkpoint completion before we've updated and unlocked
751 * the log items. This affects (at least) processing of stale buffers,
752 * inodes and EFIs.
753 */
Dave Chinner991aaf62013-08-12 20:50:07 +1000754 xfs_trans_free_items(tp, tp->t_commit_lsn, 0);
Dave Chinnera44f13e2010-08-24 11:40:03 +1000755
Dave Chinner4c2d5422012-04-23 17:54:32 +1000756 xlog_cil_push_background(log);
Dave Chinnera44f13e2010-08-24 11:40:03 +1000757
Dave Chinner991aaf62013-08-12 20:50:07 +1000758 up_read(&cil->xc_ctx_lock);
Christoph Hellwig0244b962011-12-06 21:58:08 +0000759 return 0;
Dave Chinnera44f13e2010-08-24 11:40:03 +1000760}
761
762/*
Dave Chinner71e330b2010-05-21 14:37:18 +1000763 * Conditionally push the CIL based on the sequence passed in.
764 *
765 * We only need to push if we haven't already pushed the sequence
766 * number given. Hence the only time we will trigger a push here is
767 * if the push sequence is the same as the current context.
768 *
769 * We return the current commit lsn to allow the callers to determine if a
770 * iclog flush is necessary following this call.
Dave Chinner71e330b2010-05-21 14:37:18 +1000771 */
772xfs_lsn_t
Dave Chinnera44f13e2010-08-24 11:40:03 +1000773xlog_cil_force_lsn(
Mark Tinguelyf7bdf032012-06-14 09:22:15 -0500774 struct xlog *log,
Dave Chinnera44f13e2010-08-24 11:40:03 +1000775 xfs_lsn_t sequence)
Dave Chinner71e330b2010-05-21 14:37:18 +1000776{
777 struct xfs_cil *cil = log->l_cilp;
778 struct xfs_cil_ctx *ctx;
779 xfs_lsn_t commit_lsn = NULLCOMMITLSN;
780
Dave Chinnera44f13e2010-08-24 11:40:03 +1000781 ASSERT(sequence <= cil->xc_current_sequence);
Dave Chinner71e330b2010-05-21 14:37:18 +1000782
Dave Chinnera44f13e2010-08-24 11:40:03 +1000783 /*
784 * check to see if we need to force out the current context.
785 * xlog_cil_push() handles racing pushes for the same sequence,
786 * so no need to deal with it here.
787 */
Dave Chinner4c2d5422012-04-23 17:54:32 +1000788 xlog_cil_push_foreground(log, sequence);
Dave Chinner71e330b2010-05-21 14:37:18 +1000789
790 /*
791 * See if we can find a previous sequence still committing.
Dave Chinner71e330b2010-05-21 14:37:18 +1000792 * We need to wait for all previous sequence commits to complete
793 * before allowing the force of push_seq to go ahead. Hence block
794 * on commits for those as well.
795 */
Dave Chinnera44f13e2010-08-24 11:40:03 +1000796restart:
Dave Chinner4bb928c2013-08-12 20:50:08 +1000797 spin_lock(&cil->xc_push_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000798 list_for_each_entry(ctx, &cil->xc_committing, committing) {
Dave Chinnera44f13e2010-08-24 11:40:03 +1000799 if (ctx->sequence > sequence)
Dave Chinner71e330b2010-05-21 14:37:18 +1000800 continue;
801 if (!ctx->commit_lsn) {
802 /*
803 * It is still being pushed! Wait for the push to
804 * complete, then start again from the beginning.
805 */
Dave Chinner4bb928c2013-08-12 20:50:08 +1000806 xlog_wait(&cil->xc_commit_wait, &cil->xc_push_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000807 goto restart;
808 }
Dave Chinnera44f13e2010-08-24 11:40:03 +1000809 if (ctx->sequence != sequence)
Dave Chinner71e330b2010-05-21 14:37:18 +1000810 continue;
811 /* found it! */
812 commit_lsn = ctx->commit_lsn;
813 }
Dave Chinner4bb928c2013-08-12 20:50:08 +1000814 spin_unlock(&cil->xc_push_lock);
Dave Chinner71e330b2010-05-21 14:37:18 +1000815 return commit_lsn;
816}
Dave Chinnerccf7c232010-05-20 23:19:42 +1000817
818/*
819 * Check if the current log item was first committed in this sequence.
820 * We can't rely on just the log item being in the CIL, we have to check
821 * the recorded commit sequence number.
822 *
823 * Note: for this to be used in a non-racy manner, it has to be called with
824 * CIL flushing locked out. As a result, it should only be used during the
825 * transaction commit process when deciding what to format into the item.
826 */
827bool
828xfs_log_item_in_current_chkpt(
829 struct xfs_log_item *lip)
830{
831 struct xfs_cil_ctx *ctx;
832
Dave Chinnerccf7c232010-05-20 23:19:42 +1000833 if (list_empty(&lip->li_cil))
834 return false;
835
836 ctx = lip->li_mountp->m_log->l_cilp->xc_ctx;
837
838 /*
839 * li_seq is written on the first commit of a log item to record the
840 * first checkpoint it is written to. Hence if it is different to the
841 * current sequence, we're in a new checkpoint.
842 */
843 if (XFS_LSN_CMP(lip->li_seq, ctx->sequence) != 0)
844 return false;
845 return true;
846}
Dave Chinner4c2d5422012-04-23 17:54:32 +1000847
848/*
849 * Perform initial CIL structure initialisation.
850 */
851int
852xlog_cil_init(
Mark Tinguelyf7bdf032012-06-14 09:22:15 -0500853 struct xlog *log)
Dave Chinner4c2d5422012-04-23 17:54:32 +1000854{
855 struct xfs_cil *cil;
856 struct xfs_cil_ctx *ctx;
857
858 cil = kmem_zalloc(sizeof(*cil), KM_SLEEP|KM_MAYFAIL);
859 if (!cil)
860 return ENOMEM;
861
862 ctx = kmem_zalloc(sizeof(*ctx), KM_SLEEP|KM_MAYFAIL);
863 if (!ctx) {
864 kmem_free(cil);
865 return ENOMEM;
866 }
867
868 INIT_WORK(&cil->xc_push_work, xlog_cil_push_work);
869 INIT_LIST_HEAD(&cil->xc_cil);
870 INIT_LIST_HEAD(&cil->xc_committing);
871 spin_lock_init(&cil->xc_cil_lock);
Dave Chinner4bb928c2013-08-12 20:50:08 +1000872 spin_lock_init(&cil->xc_push_lock);
Dave Chinner4c2d5422012-04-23 17:54:32 +1000873 init_rwsem(&cil->xc_ctx_lock);
874 init_waitqueue_head(&cil->xc_commit_wait);
875
876 INIT_LIST_HEAD(&ctx->committing);
877 INIT_LIST_HEAD(&ctx->busy_extents);
878 ctx->sequence = 1;
879 ctx->cil = cil;
880 cil->xc_ctx = ctx;
881 cil->xc_current_sequence = ctx->sequence;
882
883 cil->xc_log = log;
884 log->l_cilp = cil;
885 return 0;
886}
887
888void
889xlog_cil_destroy(
Mark Tinguelyf7bdf032012-06-14 09:22:15 -0500890 struct xlog *log)
Dave Chinner4c2d5422012-04-23 17:54:32 +1000891{
892 if (log->l_cilp->xc_ctx) {
893 if (log->l_cilp->xc_ctx->ticket)
894 xfs_log_ticket_put(log->l_cilp->xc_ctx->ticket);
895 kmem_free(log->l_cilp->xc_ctx);
896 }
897
898 ASSERT(list_empty(&log->l_cilp->xc_cil));
899 kmem_free(log->l_cilp);
900}
901