?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
fs/nilfs2: convert timers to use timer_setup()
[linux-2.6/btrfs-unstable.git] / fs / nilfs2 / segment.c
blob472f0b53a7247b22376d1483bbb6057474e24431
1 /*
2 * segment.c - NILFS segment constructor.
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * Written by Ryusuke Konishi.
17 *
18 */
19
20 #include <linux/pagemap.h>
21 #include <linux/buffer_head.h>
22 #include <linux/writeback.h>
23 #include <linux/bitops.h>
24 #include <linux/bio.h>
25 #include <linux/completion.h>
26 #include <linux/blkdev.h>
27 #include <linux/backing-dev.h>
28 #include <linux/freezer.h>
29 #include <linux/kthread.h>
30 #include <linux/crc32.h>
31 #include <linux/pagevec.h>
32 #include <linux/slab.h>
33 #include <linux/sched/signal.h>
34
35 #include "nilfs.h"
36 #include "btnode.h"
37 #include "page.h"
38 #include "segment.h"
39 #include "sufile.h"
40 #include "cpfile.h"
41 #include "ifile.h"
42 #include "segbuf.h"
43
44
45 /*
46 * Segment constructor
47 */
48 #define SC_N_INODEVEC 16 /* Size of locally allocated inode vector */
49
50 #define SC_MAX_SEGDELTA 64 /*
51 * Upper limit of the number of segments
52 * appended in collection retry loop
53 */
54
55 /* Construction mode */
56 enum {
57 SC_LSEG_SR = 1, /* Make a logical segment having a super root */
58 SC_LSEG_DSYNC, /*
59 * Flush data blocks of a given file and make
60 * a logical segment without a super root.
61 */
62 SC_FLUSH_FILE, /*
63 * Flush data files, leads to segment writes without
64 * creating a checkpoint.
65 */
66 SC_FLUSH_DAT, /*
67 * Flush DAT file. This also creates segments
68 * without a checkpoint.
69 */
70 };
71
72 /* Stage numbers of dirty block collection */
73 enum {
74 NILFS_ST_INIT = 0,
75 NILFS_ST_GC, /* Collecting dirty blocks for GC */
76 NILFS_ST_FILE,
77 NILFS_ST_IFILE,
78 NILFS_ST_CPFILE,
79 NILFS_ST_SUFILE,
80 NILFS_ST_DAT,
81 NILFS_ST_SR, /* Super root */
82 NILFS_ST_DSYNC, /* Data sync blocks */
83 NILFS_ST_DONE,
84 };
85
86 #define CREATE_TRACE_POINTS
87 #include <trace/events/nilfs2.h>
88
89 /*
90 * nilfs_sc_cstage_inc(), nilfs_sc_cstage_set(), nilfs_sc_cstage_get() are
91 * wrapper functions of stage count (nilfs_sc_info->sc_stage.scnt). Users of
92 * the variable must use them because transition of stage count must involve
93 * trace events (trace_nilfs2_collection_stage_transition).
94 *
95 * nilfs_sc_cstage_get() isn't required for the above purpose because it doesn't
96 * produce tracepoint events. It is provided just for making the intention
97 * clear.
98 */
99 static inline void nilfs_sc_cstage_inc(struct nilfs_sc_info *sci)
100 {
101 sci->sc_stage.scnt++;
102 trace_nilfs2_collection_stage_transition(sci);
103 }
104
105 static inline void nilfs_sc_cstage_set(struct nilfs_sc_info *sci, int next_scnt)
106 {
107 sci->sc_stage.scnt = next_scnt;
108 trace_nilfs2_collection_stage_transition(sci);
109 }
110
111 static inline int nilfs_sc_cstage_get(struct nilfs_sc_info *sci)
112 {
113 return sci->sc_stage.scnt;
114 }
115
116 /* State flags of collection */
117 #define NILFS_CF_NODE 0x0001 /* Collecting node blocks */
118 #define NILFS_CF_IFILE_STARTED 0x0002 /* IFILE stage has started */
119 #define NILFS_CF_SUFREED 0x0004 /* segment usages has been freed */
120 #define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED)
121
122 /* Operations depending on the construction mode and file type */
123 struct nilfs_sc_operations {
124 int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *,
125 struct inode *);
126 int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *,
127 struct inode *);
128 int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *,
129 struct inode *);
130 void (*write_data_binfo)(struct nilfs_sc_info *,
131 struct nilfs_segsum_pointer *,
132 union nilfs_binfo *);
133 void (*write_node_binfo)(struct nilfs_sc_info *,
134 struct nilfs_segsum_pointer *,
135 union nilfs_binfo *);
136 };
137
138 /*
139 * Other definitions
140 */
141 static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
142 static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
143 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
144 static void nilfs_dispose_list(struct the_nilfs *, struct list_head *, int);
145
146 #define nilfs_cnt32_gt(a, b) \
147 (typecheck(__u32, a) && typecheck(__u32, b) && \
148 ((__s32)(b) - (__s32)(a) < 0))
149 #define nilfs_cnt32_ge(a, b) \
150 (typecheck(__u32, a) && typecheck(__u32, b) && \
151 ((__s32)(a) - (__s32)(b) >= 0))
152 #define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a)
153 #define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a)
154
155 static int nilfs_prepare_segment_lock(struct super_block *sb,
156 struct nilfs_transaction_info *ti)
157 {
158 struct nilfs_transaction_info *cur_ti = current->journal_info;
159 void *save = NULL;
160
161 if (cur_ti) {
162 if (cur_ti->ti_magic == NILFS_TI_MAGIC)
163 return ++cur_ti->ti_count;
164
165 /*
166 * If journal_info field is occupied by other FS,
167 * it is saved and will be restored on
168 * nilfs_transaction_commit().
169 */
170 nilfs_msg(sb, KERN_WARNING, "journal info from a different FS");
171 save = current->journal_info;
172 }
173 if (!ti) {
174 ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
175 if (!ti)
176 return -ENOMEM;
177 ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
178 } else {
179 ti->ti_flags = 0;
180 }
181 ti->ti_count = 0;
182 ti->ti_save = save;
183 ti->ti_magic = NILFS_TI_MAGIC;
184 current->journal_info = ti;
185 return 0;
186 }
187
188 /**
189 * nilfs_transaction_begin - start indivisible file operations.
190 * @sb: super block
191 * @ti: nilfs_transaction_info
192 * @vacancy_check: flags for vacancy rate checks
193 *
194 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
195 * the segment semaphore, to make a segment construction and write tasks
196 * exclusive. The function is used with nilfs_transaction_commit() in pairs.
197 * The region enclosed by these two functions can be nested. To avoid a
198 * deadlock, the semaphore is only acquired or released in the outermost call.
199 *
200 * This function allocates a nilfs_transaction_info struct to keep context
201 * information on it. It is initialized and hooked onto the current task in
202 * the outermost call. If a pre-allocated struct is given to @ti, it is used
203 * instead; otherwise a new struct is assigned from a slab.
204 *
205 * When @vacancy_check flag is set, this function will check the amount of
206 * free space, and will wait for the GC to reclaim disk space if low capacity.
207 *
208 * Return Value: On success, 0 is returned. On error, one of the following
209 * negative error code is returned.
210 *
211 * %-ENOMEM - Insufficient memory available.
212 *
213 * %-ENOSPC - No space left on device
214 */
215 int nilfs_transaction_begin(struct super_block *sb,
216 struct nilfs_transaction_info *ti,
217 int vacancy_check)
218 {
219 struct the_nilfs *nilfs;
220 int ret = nilfs_prepare_segment_lock(sb, ti);
221 struct nilfs_transaction_info *trace_ti;
222
223 if (unlikely(ret < 0))
224 return ret;
225 if (ret > 0) {
226 trace_ti = current->journal_info;
227
228 trace_nilfs2_transaction_transition(sb, trace_ti,
229 trace_ti->ti_count, trace_ti->ti_flags,
230 TRACE_NILFS2_TRANSACTION_BEGIN);
231 return 0;
232 }
233
234 sb_start_intwrite(sb);
235
236 nilfs = sb->s_fs_info;
237 down_read(&nilfs->ns_segctor_sem);
238 if (vacancy_check && nilfs_near_disk_full(nilfs)) {
239 up_read(&nilfs->ns_segctor_sem);
240 ret = -ENOSPC;
241 goto failed;
242 }
243
244 trace_ti = current->journal_info;
245 trace_nilfs2_transaction_transition(sb, trace_ti, trace_ti->ti_count,
246 trace_ti->ti_flags,
247 TRACE_NILFS2_TRANSACTION_BEGIN);
248 return 0;
249
250 failed:
251 ti = current->journal_info;
252 current->journal_info = ti->ti_save;
253 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
254 kmem_cache_free(nilfs_transaction_cachep, ti);
255 sb_end_intwrite(sb);
256 return ret;
257 }
258
259 /**
260 * nilfs_transaction_commit - commit indivisible file operations.
261 * @sb: super block
262 *
263 * nilfs_transaction_commit() releases the read semaphore which is
264 * acquired by nilfs_transaction_begin(). This is only performed
265 * in outermost call of this function. If a commit flag is set,
266 * nilfs_transaction_commit() sets a timer to start the segment
267 * constructor. If a sync flag is set, it starts construction
268 * directly.
269 */
270 int nilfs_transaction_commit(struct super_block *sb)
271 {
272 struct nilfs_transaction_info *ti = current->journal_info;
273 struct the_nilfs *nilfs = sb->s_fs_info;
274 int err = 0;
275
276 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
277 ti->ti_flags |= NILFS_TI_COMMIT;
278 if (ti->ti_count > 0) {
279 ti->ti_count--;
280 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
281 ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
282 return 0;
283 }
284 if (nilfs->ns_writer) {
285 struct nilfs_sc_info *sci = nilfs->ns_writer;
286
287 if (ti->ti_flags & NILFS_TI_COMMIT)
288 nilfs_segctor_start_timer(sci);
289 if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark)
290 nilfs_segctor_do_flush(sci, 0);
291 }
292 up_read(&nilfs->ns_segctor_sem);
293 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
294 ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
295
296 current->journal_info = ti->ti_save;
297
298 if (ti->ti_flags & NILFS_TI_SYNC)
299 err = nilfs_construct_segment(sb);
300 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
301 kmem_cache_free(nilfs_transaction_cachep, ti);
302 sb_end_intwrite(sb);
303 return err;
304 }
305
306 void nilfs_transaction_abort(struct super_block *sb)
307 {
308 struct nilfs_transaction_info *ti = current->journal_info;
309 struct the_nilfs *nilfs = sb->s_fs_info;
310
311 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
312 if (ti->ti_count > 0) {
313 ti->ti_count--;
314 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
315 ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
316 return;
317 }
318 up_read(&nilfs->ns_segctor_sem);
319
320 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
321 ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
322
323 current->journal_info = ti->ti_save;
324 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
325 kmem_cache_free(nilfs_transaction_cachep, ti);
326 sb_end_intwrite(sb);
327 }
328
329 void nilfs_relax_pressure_in_lock(struct super_block *sb)
330 {
331 struct the_nilfs *nilfs = sb->s_fs_info;
332 struct nilfs_sc_info *sci = nilfs->ns_writer;
333
334 if (!sci || !sci->sc_flush_request)
335 return;
336
337 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
338 up_read(&nilfs->ns_segctor_sem);
339
340 down_write(&nilfs->ns_segctor_sem);
341 if (sci->sc_flush_request &&
342 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
343 struct nilfs_transaction_info *ti = current->journal_info;
344
345 ti->ti_flags |= NILFS_TI_WRITER;
346 nilfs_segctor_do_immediate_flush(sci);
347 ti->ti_flags &= ~NILFS_TI_WRITER;
348 }
349 downgrade_write(&nilfs->ns_segctor_sem);
350 }
351
352 static void nilfs_transaction_lock(struct super_block *sb,
353 struct nilfs_transaction_info *ti,
354 int gcflag)
355 {
356 struct nilfs_transaction_info *cur_ti = current->journal_info;
357 struct the_nilfs *nilfs = sb->s_fs_info;
358 struct nilfs_sc_info *sci = nilfs->ns_writer;
359
360 WARN_ON(cur_ti);
361 ti->ti_flags = NILFS_TI_WRITER;
362 ti->ti_count = 0;
363 ti->ti_save = cur_ti;
364 ti->ti_magic = NILFS_TI_MAGIC;
365 current->journal_info = ti;
366
367 for (;;) {
368 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
369 ti->ti_flags, TRACE_NILFS2_TRANSACTION_TRYLOCK);
370
371 down_write(&nilfs->ns_segctor_sem);
372 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags))
373 break;
374
375 nilfs_segctor_do_immediate_flush(sci);
376
377 up_write(&nilfs->ns_segctor_sem);
378 cond_resched();
379 }
380 if (gcflag)
381 ti->ti_flags |= NILFS_TI_GC;
382
383 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
384 ti->ti_flags, TRACE_NILFS2_TRANSACTION_LOCK);
385 }
386
387 static void nilfs_transaction_unlock(struct super_block *sb)
388 {
389 struct nilfs_transaction_info *ti = current->journal_info;
390 struct the_nilfs *nilfs = sb->s_fs_info;
391
392 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
393 BUG_ON(ti->ti_count > 0);
394
395 up_write(&nilfs->ns_segctor_sem);
396 current->journal_info = ti->ti_save;
397
398 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
399 ti->ti_flags, TRACE_NILFS2_TRANSACTION_UNLOCK);
400 }
401
402 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
403 struct nilfs_segsum_pointer *ssp,
404 unsigned int bytes)
405 {
406 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
407 unsigned int blocksize = sci->sc_super->s_blocksize;
408 void *p;
409
410 if (unlikely(ssp->offset + bytes > blocksize)) {
411 ssp->offset = 0;
412 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
413 &segbuf->sb_segsum_buffers));
414 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
415 }
416 p = ssp->bh->b_data + ssp->offset;
417 ssp->offset += bytes;
418 return p;
419 }
420
421 /**
422 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
423 * @sci: nilfs_sc_info
424 */
425 static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
426 {
427 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
428 struct buffer_head *sumbh;
429 unsigned int sumbytes;
430 unsigned int flags = 0;
431 int err;
432
433 if (nilfs_doing_gc())
434 flags = NILFS_SS_GC;
435 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno);
436 if (unlikely(err))
437 return err;
438
439 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
440 sumbytes = segbuf->sb_sum.sumbytes;
441 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
442 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
443 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
444 return 0;
445 }
446
447 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
448 {
449 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
450 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
451 return -E2BIG; /*
452 * The current segment is filled up
453 * (internal code)
454 */
455 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
456 return nilfs_segctor_reset_segment_buffer(sci);
457 }
458
459 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
460 {
461 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
462 int err;
463
464 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
465 err = nilfs_segctor_feed_segment(sci);
466 if (err)
467 return err;
468 segbuf = sci->sc_curseg;
469 }
470 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root);
471 if (likely(!err))
472 segbuf->sb_sum.flags |= NILFS_SS_SR;
473 return err;
474 }
475
476 /*
477 * Functions for making segment summary and payloads
478 */
479 static int nilfs_segctor_segsum_block_required(
480 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
481 unsigned int binfo_size)
482 {
483 unsigned int blocksize = sci->sc_super->s_blocksize;
484 /* Size of finfo and binfo is enough small against blocksize */
485
486 return ssp->offset + binfo_size +
487 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
488 blocksize;
489 }
490
491 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
492 struct inode *inode)
493 {
494 sci->sc_curseg->sb_sum.nfinfo++;
495 sci->sc_binfo_ptr = sci->sc_finfo_ptr;
496 nilfs_segctor_map_segsum_entry(
497 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
498
499 if (NILFS_I(inode)->i_root &&
500 !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
501 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
502 /* skip finfo */
503 }
504
505 static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
506 struct inode *inode)
507 {
508 struct nilfs_finfo *finfo;
509 struct nilfs_inode_info *ii;
510 struct nilfs_segment_buffer *segbuf;
511 __u64 cno;
512
513 if (sci->sc_blk_cnt == 0)
514 return;
515
516 ii = NILFS_I(inode);
517
518 if (test_bit(NILFS_I_GCINODE, &ii->i_state))
519 cno = ii->i_cno;
520 else if (NILFS_ROOT_METADATA_FILE(inode->i_ino))
521 cno = 0;
522 else
523 cno = sci->sc_cno;
524
525 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
526 sizeof(*finfo));
527 finfo->fi_ino = cpu_to_le64(inode->i_ino);
528 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
529 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
530 finfo->fi_cno = cpu_to_le64(cno);
531
532 segbuf = sci->sc_curseg;
533 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
534 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
535 sci->sc_finfo_ptr = sci->sc_binfo_ptr;
536 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
537 }
538
539 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
540 struct buffer_head *bh,
541 struct inode *inode,
542 unsigned int binfo_size)
543 {
544 struct nilfs_segment_buffer *segbuf;
545 int required, err = 0;
546
547 retry:
548 segbuf = sci->sc_curseg;
549 required = nilfs_segctor_segsum_block_required(
550 sci, &sci->sc_binfo_ptr, binfo_size);
551 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
552 nilfs_segctor_end_finfo(sci, inode);
553 err = nilfs_segctor_feed_segment(sci);
554 if (err)
555 return err;
556 goto retry;
557 }
558 if (unlikely(required)) {
559 err = nilfs_segbuf_extend_segsum(segbuf);
560 if (unlikely(err))
561 goto failed;
562 }
563 if (sci->sc_blk_cnt == 0)
564 nilfs_segctor_begin_finfo(sci, inode);
565
566 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
567 /* Substitution to vblocknr is delayed until update_blocknr() */
568 nilfs_segbuf_add_file_buffer(segbuf, bh);
569 sci->sc_blk_cnt++;
570 failed:
571 return err;
572 }
573
574 /*
575 * Callback functions that enumerate, mark, and collect dirty blocks
576 */
577 static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
578 struct buffer_head *bh, struct inode *inode)
579 {
580 int err;
581
582 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
583 if (err < 0)
584 return err;
585
586 err = nilfs_segctor_add_file_block(sci, bh, inode,
587 sizeof(struct nilfs_binfo_v));
588 if (!err)
589 sci->sc_datablk_cnt++;
590 return err;
591 }
592
593 static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
594 struct buffer_head *bh,
595 struct inode *inode)
596 {
597 return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
598 }
599
600 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
601 struct buffer_head *bh,
602 struct inode *inode)
603 {
604 WARN_ON(!buffer_dirty(bh));
605 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
606 }
607
608 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
609 struct nilfs_segsum_pointer *ssp,
610 union nilfs_binfo *binfo)
611 {
612 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
613 sci, ssp, sizeof(*binfo_v));
614 *binfo_v = binfo->bi_v;
615 }
616
617 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
618 struct nilfs_segsum_pointer *ssp,
619 union nilfs_binfo *binfo)
620 {
621 __le64 *vblocknr = nilfs_segctor_map_segsum_entry(
622 sci, ssp, sizeof(*vblocknr));
623 *vblocknr = binfo->bi_v.bi_vblocknr;
624 }
625
626 static const struct nilfs_sc_operations nilfs_sc_file_ops = {
627 .collect_data = nilfs_collect_file_data,
628 .collect_node = nilfs_collect_file_node,
629 .collect_bmap = nilfs_collect_file_bmap,
630 .write_data_binfo = nilfs_write_file_data_binfo,
631 .write_node_binfo = nilfs_write_file_node_binfo,
632 };
633
634 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
635 struct buffer_head *bh, struct inode *inode)
636 {
637 int err;
638
639 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
640 if (err < 0)
641 return err;
642
643 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
644 if (!err)
645 sci->sc_datablk_cnt++;
646 return err;
647 }
648
649 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
650 struct buffer_head *bh, struct inode *inode)
651 {
652 WARN_ON(!buffer_dirty(bh));
653 return nilfs_segctor_add_file_block(sci, bh, inode,
654 sizeof(struct nilfs_binfo_dat));
655 }
656
657 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
658 struct nilfs_segsum_pointer *ssp,
659 union nilfs_binfo *binfo)
660 {
661 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
662 sizeof(*blkoff));
663 *blkoff = binfo->bi_dat.bi_blkoff;
664 }
665
666 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
667 struct nilfs_segsum_pointer *ssp,
668 union nilfs_binfo *binfo)
669 {
670 struct nilfs_binfo_dat *binfo_dat =
671 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
672 *binfo_dat = binfo->bi_dat;
673 }
674
675 static const struct nilfs_sc_operations nilfs_sc_dat_ops = {
676 .collect_data = nilfs_collect_dat_data,
677 .collect_node = nilfs_collect_file_node,
678 .collect_bmap = nilfs_collect_dat_bmap,
679 .write_data_binfo = nilfs_write_dat_data_binfo,
680 .write_node_binfo = nilfs_write_dat_node_binfo,
681 };
682
683 static const struct nilfs_sc_operations nilfs_sc_dsync_ops = {
684 .collect_data = nilfs_collect_file_data,
685 .collect_node = NULL,
686 .collect_bmap = NULL,
687 .write_data_binfo = nilfs_write_file_data_binfo,
688 .write_node_binfo = NULL,
689 };
690
691 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
692 struct list_head *listp,
693 size_t nlimit,
694 loff_t start, loff_t end)
695 {
696 struct address_space *mapping = inode->i_mapping;
697 struct pagevec pvec;
698 pgoff_t index = 0, last = ULONG_MAX;
699 size_t ndirties = 0;
700 int i;
701
702 if (unlikely(start != 0 || end != LLONG_MAX)) {
703 /*
704 * A valid range is given for sync-ing data pages. The
705 * range is rounded to per-page; extra dirty buffers
706 * may be included if blocksize < pagesize.
707 */
708 index = start >> PAGE_SHIFT;
709 last = end >> PAGE_SHIFT;
710 }
711 pagevec_init(&pvec);
712 repeat:
713 if (unlikely(index > last) ||
714 !pagevec_lookup_range_tag(&pvec, mapping, &index, last,
715 PAGECACHE_TAG_DIRTY))
716 return ndirties;
717
718 for (i = 0; i < pagevec_count(&pvec); i++) {
719 struct buffer_head *bh, *head;
720 struct page *page = pvec.pages[i];
721
722 lock_page(page);
723 if (!page_has_buffers(page))
724 create_empty_buffers(page, i_blocksize(inode), 0);
725 unlock_page(page);
726
727 bh = head = page_buffers(page);
728 do {
729 if (!buffer_dirty(bh) || buffer_async_write(bh))
730 continue;
731 get_bh(bh);
732 list_add_tail(&bh->b_assoc_buffers, listp);
733 ndirties++;
734 if (unlikely(ndirties >= nlimit)) {
735 pagevec_release(&pvec);
736 cond_resched();
737 return ndirties;
738 }
739 } while (bh = bh->b_this_page, bh != head);
740 }
741 pagevec_release(&pvec);
742 cond_resched();
743 goto repeat;
744 }
745
746 static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
747 struct list_head *listp)
748 {
749 struct nilfs_inode_info *ii = NILFS_I(inode);
750 struct address_space *mapping = &ii->i_btnode_cache;
751 struct pagevec pvec;
752 struct buffer_head *bh, *head;
753 unsigned int i;
754 pgoff_t index = 0;
755
756 pagevec_init(&pvec);
757
758 while (pagevec_lookup_tag(&pvec, mapping, &index,
759 PAGECACHE_TAG_DIRTY)) {
760 for (i = 0; i < pagevec_count(&pvec); i++) {
761 bh = head = page_buffers(pvec.pages[i]);
762 do {
763 if (buffer_dirty(bh) &&
764 !buffer_async_write(bh)) {
765 get_bh(bh);
766 list_add_tail(&bh->b_assoc_buffers,
767 listp);
768 }
769 bh = bh->b_this_page;
770 } while (bh != head);
771 }
772 pagevec_release(&pvec);
773 cond_resched();
774 }
775 }
776
777 static void nilfs_dispose_list(struct the_nilfs *nilfs,
778 struct list_head *head, int force)
779 {
780 struct nilfs_inode_info *ii, *n;
781 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
782 unsigned int nv = 0;
783
784 while (!list_empty(head)) {
785 spin_lock(&nilfs->ns_inode_lock);
786 list_for_each_entry_safe(ii, n, head, i_dirty) {
787 list_del_init(&ii->i_dirty);
788 if (force) {
789 if (unlikely(ii->i_bh)) {
790 brelse(ii->i_bh);
791 ii->i_bh = NULL;
792 }
793 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
794 set_bit(NILFS_I_QUEUED, &ii->i_state);
795 list_add_tail(&ii->i_dirty,
796 &nilfs->ns_dirty_files);
797 continue;
798 }
799 ivec[nv++] = ii;
800 if (nv == SC_N_INODEVEC)
801 break;
802 }
803 spin_unlock(&nilfs->ns_inode_lock);
804
805 for (pii = ivec; nv > 0; pii++, nv--)
806 iput(&(*pii)->vfs_inode);
807 }
808 }
809
810 static void nilfs_iput_work_func(struct work_struct *work)
811 {
812 struct nilfs_sc_info *sci = container_of(work, struct nilfs_sc_info,
813 sc_iput_work);
814 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
815
816 nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 0);
817 }
818
819 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
820 struct nilfs_root *root)
821 {
822 int ret = 0;
823
824 if (nilfs_mdt_fetch_dirty(root->ifile))
825 ret++;
826 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
827 ret++;
828 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
829 ret++;
830 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat))
831 ret++;
832 return ret;
833 }
834
835 static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
836 {
837 return list_empty(&sci->sc_dirty_files) &&
838 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
839 sci->sc_nfreesegs == 0 &&
840 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
841 }
842
843 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
844 {
845 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
846 int ret = 0;
847
848 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
849 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
850
851 spin_lock(&nilfs->ns_inode_lock);
852 if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci))
853 ret++;
854
855 spin_unlock(&nilfs->ns_inode_lock);
856 return ret;
857 }
858
859 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
860 {
861 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
862
863 nilfs_mdt_clear_dirty(sci->sc_root->ifile);
864 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
865 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
866 nilfs_mdt_clear_dirty(nilfs->ns_dat);
867 }
868
869 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
870 {
871 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
872 struct buffer_head *bh_cp;
873 struct nilfs_checkpoint *raw_cp;
874 int err;
875
876 /* XXX: this interface will be changed */
877 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
878 &raw_cp, &bh_cp);
879 if (likely(!err)) {
880 /*
881 * The following code is duplicated with cpfile. But, it is
882 * needed to collect the checkpoint even if it was not newly
883 * created.
884 */
885 mark_buffer_dirty(bh_cp);
886 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
887 nilfs_cpfile_put_checkpoint(
888 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
889 } else
890 WARN_ON(err == -EINVAL || err == -ENOENT);
891
892 return err;
893 }
894
895 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
896 {
897 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
898 struct buffer_head *bh_cp;
899 struct nilfs_checkpoint *raw_cp;
900 int err;
901
902 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
903 &raw_cp, &bh_cp);
904 if (unlikely(err)) {
905 WARN_ON(err == -EINVAL || err == -ENOENT);
906 goto failed_ibh;
907 }
908 raw_cp->cp_snapshot_list.ssl_next = 0;
909 raw_cp->cp_snapshot_list.ssl_prev = 0;
910 raw_cp->cp_inodes_count =
911 cpu_to_le64(atomic64_read(&sci->sc_root->inodes_count));
912 raw_cp->cp_blocks_count =
913 cpu_to_le64(atomic64_read(&sci->sc_root->blocks_count));
914 raw_cp->cp_nblk_inc =
915 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
916 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
917 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
918
919 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
920 nilfs_checkpoint_clear_minor(raw_cp);
921 else
922 nilfs_checkpoint_set_minor(raw_cp);
923
924 nilfs_write_inode_common(sci->sc_root->ifile,
925 &raw_cp->cp_ifile_inode, 1);
926 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
927 return 0;
928
929 failed_ibh:
930 return err;
931 }
932
933 static void nilfs_fill_in_file_bmap(struct inode *ifile,
934 struct nilfs_inode_info *ii)
935
936 {
937 struct buffer_head *ibh;
938 struct nilfs_inode *raw_inode;
939
940 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
941 ibh = ii->i_bh;
942 BUG_ON(!ibh);
943 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
944 ibh);
945 nilfs_bmap_write(ii->i_bmap, raw_inode);
946 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
947 }
948 }
949
950 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
951 {
952 struct nilfs_inode_info *ii;
953
954 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
955 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
956 set_bit(NILFS_I_COLLECTED, &ii->i_state);
957 }
958 }
959
960 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
961 struct the_nilfs *nilfs)
962 {
963 struct buffer_head *bh_sr;
964 struct nilfs_super_root *raw_sr;
965 unsigned int isz, srsz;
966
967 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
968 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
969 isz = nilfs->ns_inode_size;
970 srsz = NILFS_SR_BYTES(isz);
971
972 raw_sr->sr_bytes = cpu_to_le16(srsz);
973 raw_sr->sr_nongc_ctime
974 = cpu_to_le64(nilfs_doing_gc() ?
975 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
976 raw_sr->sr_flags = 0;
977
978 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr +
979 NILFS_SR_DAT_OFFSET(isz), 1);
980 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
981 NILFS_SR_CPFILE_OFFSET(isz), 1);
982 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
983 NILFS_SR_SUFILE_OFFSET(isz), 1);
984 memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz);
985 }
986
987 static void nilfs_redirty_inodes(struct list_head *head)
988 {
989 struct nilfs_inode_info *ii;
990
991 list_for_each_entry(ii, head, i_dirty) {
992 if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
993 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
994 }
995 }
996
997 static void nilfs_drop_collected_inodes(struct list_head *head)
998 {
999 struct nilfs_inode_info *ii;
1000
1001 list_for_each_entry(ii, head, i_dirty) {
1002 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
1003 continue;
1004
1005 clear_bit(NILFS_I_INODE_SYNC, &ii->i_state);
1006 set_bit(NILFS_I_UPDATED, &ii->i_state);
1007 }
1008 }
1009
1010 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
1011 struct inode *inode,
1012 struct list_head *listp,
1013 int (*collect)(struct nilfs_sc_info *,
1014 struct buffer_head *,
1015 struct inode *))
1016 {
1017 struct buffer_head *bh, *n;
1018 int err = 0;
1019
1020 if (collect) {
1021 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
1022 list_del_init(&bh->b_assoc_buffers);
1023 err = collect(sci, bh, inode);
1024 brelse(bh);
1025 if (unlikely(err))
1026 goto dispose_buffers;
1027 }
1028 return 0;
1029 }
1030
1031 dispose_buffers:
1032 while (!list_empty(listp)) {
1033 bh = list_first_entry(listp, struct buffer_head,
1034 b_assoc_buffers);
1035 list_del_init(&bh->b_assoc_buffers);
1036 brelse(bh);
1037 }
1038 return err;
1039 }
1040
1041 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
1042 {
1043 /* Remaining number of blocks within segment buffer */
1044 return sci->sc_segbuf_nblocks -
1045 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
1046 }
1047
1048 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
1049 struct inode *inode,
1050 const struct nilfs_sc_operations *sc_ops)
1051 {
1052 LIST_HEAD(data_buffers);
1053 LIST_HEAD(node_buffers);
1054 int err;
1055
1056 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1057 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1058
1059 n = nilfs_lookup_dirty_data_buffers(
1060 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
1061 if (n > rest) {
1062 err = nilfs_segctor_apply_buffers(
1063 sci, inode, &data_buffers,
1064 sc_ops->collect_data);
1065 BUG_ON(!err); /* always receive -E2BIG or true error */
1066 goto break_or_fail;
1067 }
1068 }
1069 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
1070
1071 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1072 err = nilfs_segctor_apply_buffers(
1073 sci, inode, &data_buffers, sc_ops->collect_data);
1074 if (unlikely(err)) {
1075 /* dispose node list */
1076 nilfs_segctor_apply_buffers(
1077 sci, inode, &node_buffers, NULL);
1078 goto break_or_fail;
1079 }
1080 sci->sc_stage.flags |= NILFS_CF_NODE;
1081 }
1082 /* Collect node */
1083 err = nilfs_segctor_apply_buffers(
1084 sci, inode, &node_buffers, sc_ops->collect_node);
1085 if (unlikely(err))
1086 goto break_or_fail;
1087
1088 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1089 err = nilfs_segctor_apply_buffers(
1090 sci, inode, &node_buffers, sc_ops->collect_bmap);
1091 if (unlikely(err))
1092 goto break_or_fail;
1093
1094 nilfs_segctor_end_finfo(sci, inode);
1095 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1096
1097 break_or_fail:
1098 return err;
1099 }
1100
1101 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1102 struct inode *inode)
1103 {
1104 LIST_HEAD(data_buffers);
1105 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1106 int err;
1107
1108 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1109 sci->sc_dsync_start,
1110 sci->sc_dsync_end);
1111
1112 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1113 nilfs_collect_file_data);
1114 if (!err) {
1115 nilfs_segctor_end_finfo(sci, inode);
1116 BUG_ON(n > rest);
1117 /* always receive -E2BIG or true error if n > rest */
1118 }
1119 return err;
1120 }
1121
1122 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1123 {
1124 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1125 struct list_head *head;
1126 struct nilfs_inode_info *ii;
1127 size_t ndone;
1128 int err = 0;
1129
1130 switch (nilfs_sc_cstage_get(sci)) {
1131 case NILFS_ST_INIT:
1132 /* Pre-processes */
1133 sci->sc_stage.flags = 0;
1134
1135 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1136 sci->sc_nblk_inc = 0;
1137 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1138 if (mode == SC_LSEG_DSYNC) {
1139 nilfs_sc_cstage_set(sci, NILFS_ST_DSYNC);
1140 goto dsync_mode;
1141 }
1142 }
1143
1144 sci->sc_stage.dirty_file_ptr = NULL;
1145 sci->sc_stage.gc_inode_ptr = NULL;
1146 if (mode == SC_FLUSH_DAT) {
1147 nilfs_sc_cstage_set(sci, NILFS_ST_DAT);
1148 goto dat_stage;
1149 }
1150 nilfs_sc_cstage_inc(sci); /* Fall through */
1151 case NILFS_ST_GC:
1152 if (nilfs_doing_gc()) {
1153 head = &sci->sc_gc_inodes;
1154 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1155 head, i_dirty);
1156 list_for_each_entry_continue(ii, head, i_dirty) {
1157 err = nilfs_segctor_scan_file(
1158 sci, &ii->vfs_inode,
1159 &nilfs_sc_file_ops);
1160 if (unlikely(err)) {
1161 sci->sc_stage.gc_inode_ptr = list_entry(
1162 ii->i_dirty.prev,
1163 struct nilfs_inode_info,
1164 i_dirty);
1165 goto break_or_fail;
1166 }
1167 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1168 }
1169 sci->sc_stage.gc_inode_ptr = NULL;
1170 }
1171 nilfs_sc_cstage_inc(sci); /* Fall through */
1172 case NILFS_ST_FILE:
1173 head = &sci->sc_dirty_files;
1174 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1175 i_dirty);
1176 list_for_each_entry_continue(ii, head, i_dirty) {
1177 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1178
1179 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1180 &nilfs_sc_file_ops);
1181 if (unlikely(err)) {
1182 sci->sc_stage.dirty_file_ptr =
1183 list_entry(ii->i_dirty.prev,
1184 struct nilfs_inode_info,
1185 i_dirty);
1186 goto break_or_fail;
1187 }
1188 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1189 /* XXX: required ? */
1190 }
1191 sci->sc_stage.dirty_file_ptr = NULL;
1192 if (mode == SC_FLUSH_FILE) {
1193 nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1194 return 0;
1195 }
1196 nilfs_sc_cstage_inc(sci);
1197 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1198 /* Fall through */
1199 case NILFS_ST_IFILE:
1200 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile,
1201 &nilfs_sc_file_ops);
1202 if (unlikely(err))
1203 break;
1204 nilfs_sc_cstage_inc(sci);
1205 /* Creating a checkpoint */
1206 err = nilfs_segctor_create_checkpoint(sci);
1207 if (unlikely(err))
1208 break;
1209 /* Fall through */
1210 case NILFS_ST_CPFILE:
1211 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1212 &nilfs_sc_file_ops);
1213 if (unlikely(err))
1214 break;
1215 nilfs_sc_cstage_inc(sci); /* Fall through */
1216 case NILFS_ST_SUFILE:
1217 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1218 sci->sc_nfreesegs, &ndone);
1219 if (unlikely(err)) {
1220 nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1221 sci->sc_freesegs, ndone,
1222 NULL);
1223 break;
1224 }
1225 sci->sc_stage.flags |= NILFS_CF_SUFREED;
1226
1227 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1228 &nilfs_sc_file_ops);
1229 if (unlikely(err))
1230 break;
1231 nilfs_sc_cstage_inc(sci); /* Fall through */
1232 case NILFS_ST_DAT:
1233 dat_stage:
1234 err = nilfs_segctor_scan_file(sci, nilfs->ns_dat,
1235 &nilfs_sc_dat_ops);
1236 if (unlikely(err))
1237 break;
1238 if (mode == SC_FLUSH_DAT) {
1239 nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1240 return 0;
1241 }
1242 nilfs_sc_cstage_inc(sci); /* Fall through */
1243 case NILFS_ST_SR:
1244 if (mode == SC_LSEG_SR) {
1245 /* Appending a super root */
1246 err = nilfs_segctor_add_super_root(sci);
1247 if (unlikely(err))
1248 break;
1249 }
1250 /* End of a logical segment */
1251 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1252 nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1253 return 0;
1254 case NILFS_ST_DSYNC:
1255 dsync_mode:
1256 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1257 ii = sci->sc_dsync_inode;
1258 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1259 break;
1260
1261 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1262 if (unlikely(err))
1263 break;
1264 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1265 nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1266 return 0;
1267 case NILFS_ST_DONE:
1268 return 0;
1269 default:
1270 BUG();
1271 }
1272
1273 break_or_fail:
1274 return err;
1275 }
1276
1277 /**
1278 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1279 * @sci: nilfs_sc_info
1280 * @nilfs: nilfs object
1281 */
1282 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1283 struct the_nilfs *nilfs)
1284 {
1285 struct nilfs_segment_buffer *segbuf, *prev;
1286 __u64 nextnum;
1287 int err, alloc = 0;
1288
1289 segbuf = nilfs_segbuf_new(sci->sc_super);
1290 if (unlikely(!segbuf))
1291 return -ENOMEM;
1292
1293 if (list_empty(&sci->sc_write_logs)) {
1294 nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1295 nilfs->ns_pseg_offset, nilfs);
1296 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1297 nilfs_shift_to_next_segment(nilfs);
1298 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1299 }
1300
1301 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1302 nextnum = nilfs->ns_nextnum;
1303
1304 if (nilfs->ns_segnum == nilfs->ns_nextnum)
1305 /* Start from the head of a new full segment */
1306 alloc++;
1307 } else {
1308 /* Continue logs */
1309 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1310 nilfs_segbuf_map_cont(segbuf, prev);
1311 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1312 nextnum = prev->sb_nextnum;
1313
1314 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1315 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1316 segbuf->sb_sum.seg_seq++;
1317 alloc++;
1318 }
1319 }
1320
1321 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1322 if (err)
1323 goto failed;
1324
1325 if (alloc) {
1326 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1327 if (err)
1328 goto failed;
1329 }
1330 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1331
1332 BUG_ON(!list_empty(&sci->sc_segbufs));
1333 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1334 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1335 return 0;
1336
1337 failed:
1338 nilfs_segbuf_free(segbuf);
1339 return err;
1340 }
1341
1342 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1343 struct the_nilfs *nilfs, int nadd)
1344 {
1345 struct nilfs_segment_buffer *segbuf, *prev;
1346 struct inode *sufile = nilfs->ns_sufile;
1347 __u64 nextnextnum;
1348 LIST_HEAD(list);
1349 int err, ret, i;
1350
1351 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1352 /*
1353 * Since the segment specified with nextnum might be allocated during
1354 * the previous construction, the buffer including its segusage may
1355 * not be dirty. The following call ensures that the buffer is dirty
1356 * and will pin the buffer on memory until the sufile is written.
1357 */
1358 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1359 if (unlikely(err))
1360 return err;
1361
1362 for (i = 0; i < nadd; i++) {
1363 /* extend segment info */
1364 err = -ENOMEM;
1365 segbuf = nilfs_segbuf_new(sci->sc_super);
1366 if (unlikely(!segbuf))
1367 goto failed;
1368
1369 /* map this buffer to region of segment on-disk */
1370 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1371 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1372
1373 /* allocate the next next full segment */
1374 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1375 if (unlikely(err))
1376 goto failed_segbuf;
1377
1378 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1379 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1380
1381 list_add_tail(&segbuf->sb_list, &list);
1382 prev = segbuf;
1383 }
1384 list_splice_tail(&list, &sci->sc_segbufs);
1385 return 0;
1386
1387 failed_segbuf:
1388 nilfs_segbuf_free(segbuf);
1389 failed:
1390 list_for_each_entry(segbuf, &list, sb_list) {
1391 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1392 WARN_ON(ret); /* never fails */
1393 }
1394 nilfs_destroy_logs(&list);
1395 return err;
1396 }
1397
1398 static void nilfs_free_incomplete_logs(struct list_head *logs,
1399 struct the_nilfs *nilfs)
1400 {
1401 struct nilfs_segment_buffer *segbuf, *prev;
1402 struct inode *sufile = nilfs->ns_sufile;
1403 int ret;
1404
1405 segbuf = NILFS_FIRST_SEGBUF(logs);
1406 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1407 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1408 WARN_ON(ret); /* never fails */
1409 }
1410 if (atomic_read(&segbuf->sb_err)) {
1411 /* Case 1: The first segment failed */
1412 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1413 /*
1414 * Case 1a: Partial segment appended into an existing
1415 * segment
1416 */
1417 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1418 segbuf->sb_fseg_end);
1419 else /* Case 1b: New full segment */
1420 set_nilfs_discontinued(nilfs);
1421 }
1422
1423 prev = segbuf;
1424 list_for_each_entry_continue(segbuf, logs, sb_list) {
1425 if (prev->sb_nextnum != segbuf->sb_nextnum) {
1426 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1427 WARN_ON(ret); /* never fails */
1428 }
1429 if (atomic_read(&segbuf->sb_err) &&
1430 segbuf->sb_segnum != nilfs->ns_nextnum)
1431 /* Case 2: extended segment (!= next) failed */
1432 nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1433 prev = segbuf;
1434 }
1435 }
1436
1437 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1438 struct inode *sufile)
1439 {
1440 struct nilfs_segment_buffer *segbuf;
1441 unsigned long live_blocks;
1442 int ret;
1443
1444 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1445 live_blocks = segbuf->sb_sum.nblocks +
1446 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1447 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1448 live_blocks,
1449 sci->sc_seg_ctime);
1450 WARN_ON(ret); /* always succeed because the segusage is dirty */
1451 }
1452 }
1453
1454 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1455 {
1456 struct nilfs_segment_buffer *segbuf;
1457 int ret;
1458
1459 segbuf = NILFS_FIRST_SEGBUF(logs);
1460 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1461 segbuf->sb_pseg_start -
1462 segbuf->sb_fseg_start, 0);
1463 WARN_ON(ret); /* always succeed because the segusage is dirty */
1464
1465 list_for_each_entry_continue(segbuf, logs, sb_list) {
1466 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1467 0, 0);
1468 WARN_ON(ret); /* always succeed */
1469 }
1470 }
1471
1472 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1473 struct nilfs_segment_buffer *last,
1474 struct inode *sufile)
1475 {
1476 struct nilfs_segment_buffer *segbuf = last;
1477 int ret;
1478
1479 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1480 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1481 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1482 WARN_ON(ret);
1483 }
1484 nilfs_truncate_logs(&sci->sc_segbufs, last);
1485 }
1486
1487
1488 static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1489 struct the_nilfs *nilfs, int mode)
1490 {
1491 struct nilfs_cstage prev_stage = sci->sc_stage;
1492 int err, nadd = 1;
1493
1494 /* Collection retry loop */
1495 for (;;) {
1496 sci->sc_nblk_this_inc = 0;
1497 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1498
1499 err = nilfs_segctor_reset_segment_buffer(sci);
1500 if (unlikely(err))
1501 goto failed;
1502
1503 err = nilfs_segctor_collect_blocks(sci, mode);
1504 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1505 if (!err)
1506 break;
1507
1508 if (unlikely(err != -E2BIG))
1509 goto failed;
1510
1511 /* The current segment is filled up */
1512 if (mode != SC_LSEG_SR ||
1513 nilfs_sc_cstage_get(sci) < NILFS_ST_CPFILE)
1514 break;
1515
1516 nilfs_clear_logs(&sci->sc_segbufs);
1517
1518 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1519 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1520 sci->sc_freesegs,
1521 sci->sc_nfreesegs,
1522 NULL);
1523 WARN_ON(err); /* do not happen */
1524 sci->sc_stage.flags &= ~NILFS_CF_SUFREED;
1525 }
1526
1527 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1528 if (unlikely(err))
1529 return err;
1530
1531 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1532 sci->sc_stage = prev_stage;
1533 }
1534 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1535 return 0;
1536
1537 failed:
1538 return err;
1539 }
1540
1541 static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1542 struct buffer_head *new_bh)
1543 {
1544 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1545
1546 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1547 /* The caller must release old_bh */
1548 }
1549
1550 static int
1551 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1552 struct nilfs_segment_buffer *segbuf,
1553 int mode)
1554 {
1555 struct inode *inode = NULL;
1556 sector_t blocknr;
1557 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1558 unsigned long nblocks = 0, ndatablk = 0;
1559 const struct nilfs_sc_operations *sc_op = NULL;
1560 struct nilfs_segsum_pointer ssp;
1561 struct nilfs_finfo *finfo = NULL;
1562 union nilfs_binfo binfo;
1563 struct buffer_head *bh, *bh_org;
1564 ino_t ino = 0;
1565 int err = 0;
1566
1567 if (!nfinfo)
1568 goto out;
1569
1570 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1571 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1572 ssp.offset = sizeof(struct nilfs_segment_summary);
1573
1574 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1575 if (bh == segbuf->sb_super_root)
1576 break;
1577 if (!finfo) {
1578 finfo = nilfs_segctor_map_segsum_entry(
1579 sci, &ssp, sizeof(*finfo));
1580 ino = le64_to_cpu(finfo->fi_ino);
1581 nblocks = le32_to_cpu(finfo->fi_nblocks);
1582 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1583
1584 inode = bh->b_page->mapping->host;
1585
1586 if (mode == SC_LSEG_DSYNC)
1587 sc_op = &nilfs_sc_dsync_ops;
1588 else if (ino == NILFS_DAT_INO)
1589 sc_op = &nilfs_sc_dat_ops;
1590 else /* file blocks */
1591 sc_op = &nilfs_sc_file_ops;
1592 }
1593 bh_org = bh;
1594 get_bh(bh_org);
1595 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1596 &binfo);
1597 if (bh != bh_org)
1598 nilfs_list_replace_buffer(bh_org, bh);
1599 brelse(bh_org);
1600 if (unlikely(err))
1601 goto failed_bmap;
1602
1603 if (ndatablk > 0)
1604 sc_op->write_data_binfo(sci, &ssp, &binfo);
1605 else
1606 sc_op->write_node_binfo(sci, &ssp, &binfo);
1607
1608 blocknr++;
1609 if (--nblocks == 0) {
1610 finfo = NULL;
1611 if (--nfinfo == 0)
1612 break;
1613 } else if (ndatablk > 0)
1614 ndatablk--;
1615 }
1616 out:
1617 return 0;
1618
1619 failed_bmap:
1620 return err;
1621 }
1622
1623 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1624 {
1625 struct nilfs_segment_buffer *segbuf;
1626 int err;
1627
1628 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1629 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1630 if (unlikely(err))
1631 return err;
1632 nilfs_segbuf_fill_in_segsum(segbuf);
1633 }
1634 return 0;
1635 }
1636
1637 static void nilfs_begin_page_io(struct page *page)
1638 {
1639 if (!page || PageWriteback(page))
1640 /*
1641 * For split b-tree node pages, this function may be called
1642 * twice. We ignore the 2nd or later calls by this check.
1643 */
1644 return;
1645
1646 lock_page(page);
1647 clear_page_dirty_for_io(page);
1648 set_page_writeback(page);
1649 unlock_page(page);
1650 }
1651
1652 static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
1653 {
1654 struct nilfs_segment_buffer *segbuf;
1655 struct page *bd_page = NULL, *fs_page = NULL;
1656
1657 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1658 struct buffer_head *bh;
1659
1660 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1661 b_assoc_buffers) {
1662 if (bh->b_page != bd_page) {
1663 if (bd_page) {
1664 lock_page(bd_page);
1665 clear_page_dirty_for_io(bd_page);
1666 set_page_writeback(bd_page);
1667 unlock_page(bd_page);
1668 }
1669 bd_page = bh->b_page;
1670 }
1671 }
1672
1673 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1674 b_assoc_buffers) {
1675 set_buffer_async_write(bh);
1676 if (bh == segbuf->sb_super_root) {
1677 if (bh->b_page != bd_page) {
1678 lock_page(bd_page);
1679 clear_page_dirty_for_io(bd_page);
1680 set_page_writeback(bd_page);
1681 unlock_page(bd_page);
1682 bd_page = bh->b_page;
1683 }
1684 break;
1685 }
1686 if (bh->b_page != fs_page) {
1687 nilfs_begin_page_io(fs_page);
1688 fs_page = bh->b_page;
1689 }
1690 }
1691 }
1692 if (bd_page) {
1693 lock_page(bd_page);
1694 clear_page_dirty_for_io(bd_page);
1695 set_page_writeback(bd_page);
1696 unlock_page(bd_page);
1697 }
1698 nilfs_begin_page_io(fs_page);
1699 }
1700
1701 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1702 struct the_nilfs *nilfs)
1703 {
1704 int ret;
1705
1706 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1707 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1708 return ret;
1709 }
1710
1711 static void nilfs_end_page_io(struct page *page, int err)
1712 {
1713 if (!page)
1714 return;
1715
1716 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
1717 /*
1718 * For b-tree node pages, this function may be called twice
1719 * or more because they might be split in a segment.
1720 */
1721 if (PageDirty(page)) {
1722 /*
1723 * For pages holding split b-tree node buffers, dirty
1724 * flag on the buffers may be cleared discretely.
1725 * In that case, the page is once redirtied for
1726 * remaining buffers, and it must be cancelled if
1727 * all the buffers get cleaned later.
1728 */
1729 lock_page(page);
1730 if (nilfs_page_buffers_clean(page))
1731 __nilfs_clear_page_dirty(page);
1732 unlock_page(page);
1733 }
1734 return;
1735 }
1736
1737 if (!err) {
1738 if (!nilfs_page_buffers_clean(page))
1739 __set_page_dirty_nobuffers(page);
1740 ClearPageError(page);
1741 } else {
1742 __set_page_dirty_nobuffers(page);
1743 SetPageError(page);
1744 }
1745
1746 end_page_writeback(page);
1747 }
1748
1749 static void nilfs_abort_logs(struct list_head *logs, int err)
1750 {
1751 struct nilfs_segment_buffer *segbuf;
1752 struct page *bd_page = NULL, *fs_page = NULL;
1753 struct buffer_head *bh;
1754
1755 if (list_empty(logs))
1756 return;
1757
1758 list_for_each_entry(segbuf, logs, sb_list) {
1759 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1760 b_assoc_buffers) {
1761 if (bh->b_page != bd_page) {
1762 if (bd_page)
1763 end_page_writeback(bd_page);
1764 bd_page = bh->b_page;
1765 }
1766 }
1767
1768 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1769 b_assoc_buffers) {
1770 clear_buffer_async_write(bh);
1771 if (bh == segbuf->sb_super_root) {
1772 if (bh->b_page != bd_page) {
1773 end_page_writeback(bd_page);
1774 bd_page = bh->b_page;
1775 }
1776 break;
1777 }
1778 if (bh->b_page != fs_page) {
1779 nilfs_end_page_io(fs_page, err);
1780 fs_page = bh->b_page;
1781 }
1782 }
1783 }
1784 if (bd_page)
1785 end_page_writeback(bd_page);
1786
1787 nilfs_end_page_io(fs_page, err);
1788 }
1789
1790 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1791 struct the_nilfs *nilfs, int err)
1792 {
1793 LIST_HEAD(logs);
1794 int ret;
1795
1796 list_splice_tail_init(&sci->sc_write_logs, &logs);
1797 ret = nilfs_wait_on_logs(&logs);
1798 nilfs_abort_logs(&logs, ret ? : err);
1799
1800 list_splice_tail_init(&sci->sc_segbufs, &logs);
1801 nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1802 nilfs_free_incomplete_logs(&logs, nilfs);
1803
1804 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1805 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1806 sci->sc_freesegs,
1807 sci->sc_nfreesegs,
1808 NULL);
1809 WARN_ON(ret); /* do not happen */
1810 }
1811
1812 nilfs_destroy_logs(&logs);
1813 }
1814
1815 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1816 struct nilfs_segment_buffer *segbuf)
1817 {
1818 nilfs->ns_segnum = segbuf->sb_segnum;
1819 nilfs->ns_nextnum = segbuf->sb_nextnum;
1820 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1821 + segbuf->sb_sum.nblocks;
1822 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1823 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1824 }
1825
1826 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1827 {
1828 struct nilfs_segment_buffer *segbuf;
1829 struct page *bd_page = NULL, *fs_page = NULL;
1830 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1831 int update_sr = false;
1832
1833 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1834 struct buffer_head *bh;
1835
1836 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1837 b_assoc_buffers) {
1838 set_buffer_uptodate(bh);
1839 clear_buffer_dirty(bh);
1840 if (bh->b_page != bd_page) {
1841 if (bd_page)
1842 end_page_writeback(bd_page);
1843 bd_page = bh->b_page;
1844 }
1845 }
1846 /*
1847 * We assume that the buffers which belong to the same page
1848 * continue over the buffer list.
1849 * Under this assumption, the last BHs of pages is
1850 * identifiable by the discontinuity of bh->b_page
1851 * (page != fs_page).
1852 *
1853 * For B-tree node blocks, however, this assumption is not
1854 * guaranteed. The cleanup code of B-tree node pages needs
1855 * special care.
1856 */
1857 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1858 b_assoc_buffers) {
1859 const unsigned long set_bits = BIT(BH_Uptodate);
1860 const unsigned long clear_bits =
1861 (BIT(BH_Dirty) | BIT(BH_Async_Write) |
1862 BIT(BH_Delay) | BIT(BH_NILFS_Volatile) |
1863 BIT(BH_NILFS_Redirected));
1864
1865 set_mask_bits(&bh->b_state, clear_bits, set_bits);
1866 if (bh == segbuf->sb_super_root) {
1867 if (bh->b_page != bd_page) {
1868 end_page_writeback(bd_page);
1869 bd_page = bh->b_page;
1870 }
1871 update_sr = true;
1872 break;
1873 }
1874 if (bh->b_page != fs_page) {
1875 nilfs_end_page_io(fs_page, 0);
1876 fs_page = bh->b_page;
1877 }
1878 }
1879
1880 if (!nilfs_segbuf_simplex(segbuf)) {
1881 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
1882 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1883 sci->sc_lseg_stime = jiffies;
1884 }
1885 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
1886 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1887 }
1888 }
1889 /*
1890 * Since pages may continue over multiple segment buffers,
1891 * end of the last page must be checked outside of the loop.
1892 */
1893 if (bd_page)
1894 end_page_writeback(bd_page);
1895
1896 nilfs_end_page_io(fs_page, 0);
1897
1898 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1899
1900 if (nilfs_doing_gc())
1901 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1902 else
1903 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1904
1905 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1906
1907 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1908 nilfs_set_next_segment(nilfs, segbuf);
1909
1910 if (update_sr) {
1911 nilfs->ns_flushed_device = 0;
1912 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
1913 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
1914
1915 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
1916 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1917 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1918 nilfs_segctor_clear_metadata_dirty(sci);
1919 } else
1920 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1921 }
1922
1923 static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
1924 {
1925 int ret;
1926
1927 ret = nilfs_wait_on_logs(&sci->sc_write_logs);
1928 if (!ret) {
1929 nilfs_segctor_complete_write(sci);
1930 nilfs_destroy_logs(&sci->sc_write_logs);
1931 }
1932 return ret;
1933 }
1934
1935 static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci,
1936 struct the_nilfs *nilfs)
1937 {
1938 struct nilfs_inode_info *ii, *n;
1939 struct inode *ifile = sci->sc_root->ifile;
1940
1941 spin_lock(&nilfs->ns_inode_lock);
1942 retry:
1943 list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) {
1944 if (!ii->i_bh) {
1945 struct buffer_head *ibh;
1946 int err;
1947
1948 spin_unlock(&nilfs->ns_inode_lock);
1949 err = nilfs_ifile_get_inode_block(
1950 ifile, ii->vfs_inode.i_ino, &ibh);
1951 if (unlikely(err)) {
1952 nilfs_msg(sci->sc_super, KERN_WARNING,
1953 "log writer: error %d getting inode block (ino=%lu)",
1954 err, ii->vfs_inode.i_ino);
1955 return err;
1956 }
1957 mark_buffer_dirty(ibh);
1958 nilfs_mdt_mark_dirty(ifile);
1959 spin_lock(&nilfs->ns_inode_lock);
1960 if (likely(!ii->i_bh))
1961 ii->i_bh = ibh;
1962 else
1963 brelse(ibh);
1964 goto retry;
1965 }
1966
1967 clear_bit(NILFS_I_QUEUED, &ii->i_state);
1968 set_bit(NILFS_I_BUSY, &ii->i_state);
1969 list_move_tail(&ii->i_dirty, &sci->sc_dirty_files);
1970 }
1971 spin_unlock(&nilfs->ns_inode_lock);
1972
1973 return 0;
1974 }
1975
1976 static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
1977 struct the_nilfs *nilfs)
1978 {
1979 struct nilfs_inode_info *ii, *n;
1980 int during_mount = !(sci->sc_super->s_flags & MS_ACTIVE);
1981 int defer_iput = false;
1982
1983 spin_lock(&nilfs->ns_inode_lock);
1984 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
1985 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
1986 test_bit(NILFS_I_DIRTY, &ii->i_state))
1987 continue;
1988
1989 clear_bit(NILFS_I_BUSY, &ii->i_state);
1990 brelse(ii->i_bh);
1991 ii->i_bh = NULL;
1992 list_del_init(&ii->i_dirty);
1993 if (!ii->vfs_inode.i_nlink || during_mount) {
1994 /*
1995 * Defer calling iput() to avoid deadlocks if
1996 * i_nlink == 0 or mount is not yet finished.
1997 */
1998 list_add_tail(&ii->i_dirty, &sci->sc_iput_queue);
1999 defer_iput = true;
2000 } else {
2001 spin_unlock(&nilfs->ns_inode_lock);
2002 iput(&ii->vfs_inode);
2003 spin_lock(&nilfs->ns_inode_lock);
2004 }
2005 }
2006 spin_unlock(&nilfs->ns_inode_lock);
2007
2008 if (defer_iput)
2009 schedule_work(&sci->sc_iput_work);
2010 }
2011
2012 /*
2013 * Main procedure of segment constructor
2014 */
2015 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2016 {
2017 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2018 int err;
2019
2020 nilfs_sc_cstage_set(sci, NILFS_ST_INIT);
2021 sci->sc_cno = nilfs->ns_cno;
2022
2023 err = nilfs_segctor_collect_dirty_files(sci, nilfs);
2024 if (unlikely(err))
2025 goto out;
2026
2027 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
2028 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2029
2030 if (nilfs_segctor_clean(sci))
2031 goto out;
2032
2033 do {
2034 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2035
2036 err = nilfs_segctor_begin_construction(sci, nilfs);
2037 if (unlikely(err))
2038 goto out;
2039
2040 /* Update time stamp */
2041 sci->sc_seg_ctime = get_seconds();
2042
2043 err = nilfs_segctor_collect(sci, nilfs, mode);
2044 if (unlikely(err))
2045 goto failed;
2046
2047 /* Avoid empty segment */
2048 if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE &&
2049 nilfs_segbuf_empty(sci->sc_curseg)) {
2050 nilfs_segctor_abort_construction(sci, nilfs, 1);
2051 goto out;
2052 }
2053
2054 err = nilfs_segctor_assign(sci, mode);
2055 if (unlikely(err))
2056 goto failed;
2057
2058 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2059 nilfs_segctor_fill_in_file_bmap(sci);
2060
2061 if (mode == SC_LSEG_SR &&
2062 nilfs_sc_cstage_get(sci) >= NILFS_ST_CPFILE) {
2063 err = nilfs_segctor_fill_in_checkpoint(sci);
2064 if (unlikely(err))
2065 goto failed_to_write;
2066
2067 nilfs_segctor_fill_in_super_root(sci, nilfs);
2068 }
2069 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2070
2071 /* Write partial segments */
2072 nilfs_segctor_prepare_write(sci);
2073
2074 nilfs_add_checksums_on_logs(&sci->sc_segbufs,
2075 nilfs->ns_crc_seed);
2076
2077 err = nilfs_segctor_write(sci, nilfs);
2078 if (unlikely(err))
2079 goto failed_to_write;
2080
2081 if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE ||
2082 nilfs->ns_blocksize_bits != PAGE_SHIFT) {
2083 /*
2084 * At this point, we avoid double buffering
2085 * for blocksize < pagesize because page dirty
2086 * flag is turned off during write and dirty
2087 * buffers are not properly collected for
2088 * pages crossing over segments.
2089 */
2090 err = nilfs_segctor_wait(sci);
2091 if (err)
2092 goto failed_to_write;
2093 }
2094 } while (nilfs_sc_cstage_get(sci) != NILFS_ST_DONE);
2095
2096 out:
2097 nilfs_segctor_drop_written_files(sci, nilfs);
2098 return err;
2099
2100 failed_to_write:
2101 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2102 nilfs_redirty_inodes(&sci->sc_dirty_files);
2103
2104 failed:
2105 if (nilfs_doing_gc())
2106 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2107 nilfs_segctor_abort_construction(sci, nilfs, err);
2108 goto out;
2109 }
2110
2111 /**
2112 * nilfs_segctor_start_timer - set timer of background write
2113 * @sci: nilfs_sc_info
2114 *
2115 * If the timer has already been set, it ignores the new request.
2116 * This function MUST be called within a section locking the segment
2117 * semaphore.
2118 */
2119 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2120 {
2121 spin_lock(&sci->sc_state_lock);
2122 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2123 sci->sc_timer.expires = jiffies + sci->sc_interval;
2124 add_timer(&sci->sc_timer);
2125 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2126 }
2127 spin_unlock(&sci->sc_state_lock);
2128 }
2129
2130 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2131 {
2132 spin_lock(&sci->sc_state_lock);
2133 if (!(sci->sc_flush_request & BIT(bn))) {
2134 unsigned long prev_req = sci->sc_flush_request;
2135
2136 sci->sc_flush_request |= BIT(bn);
2137 if (!prev_req)
2138 wake_up(&sci->sc_wait_daemon);
2139 }
2140 spin_unlock(&sci->sc_state_lock);
2141 }
2142
2143 /**
2144 * nilfs_flush_segment - trigger a segment construction for resource control
2145 * @sb: super block
2146 * @ino: inode number of the file to be flushed out.
2147 */
2148 void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2149 {
2150 struct the_nilfs *nilfs = sb->s_fs_info;
2151 struct nilfs_sc_info *sci = nilfs->ns_writer;
2152
2153 if (!sci || nilfs_doing_construction())
2154 return;
2155 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2156 /* assign bit 0 to data files */
2157 }
2158
2159 struct nilfs_segctor_wait_request {
2160 wait_queue_entry_t wq;
2161 __u32 seq;
2162 int err;
2163 atomic_t done;
2164 };
2165
2166 static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2167 {
2168 struct nilfs_segctor_wait_request wait_req;
2169 int err = 0;
2170
2171 spin_lock(&sci->sc_state_lock);
2172 init_wait(&wait_req.wq);
2173 wait_req.err = 0;
2174 atomic_set(&wait_req.done, 0);
2175 wait_req.seq = ++sci->sc_seq_request;
2176 spin_unlock(&sci->sc_state_lock);
2177
2178 init_waitqueue_entry(&wait_req.wq, current);
2179 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2180 set_current_state(TASK_INTERRUPTIBLE);
2181 wake_up(&sci->sc_wait_daemon);
2182
2183 for (;;) {
2184 if (atomic_read(&wait_req.done)) {
2185 err = wait_req.err;
2186 break;
2187 }
2188 if (!signal_pending(current)) {
2189 schedule();
2190 continue;
2191 }
2192 err = -ERESTARTSYS;
2193 break;
2194 }
2195 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2196 return err;
2197 }
2198
2199 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2200 {
2201 struct nilfs_segctor_wait_request *wrq, *n;
2202 unsigned long flags;
2203
2204 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2205 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.head, wq.entry) {
2206 if (!atomic_read(&wrq->done) &&
2207 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2208 wrq->err = err;
2209 atomic_set(&wrq->done, 1);
2210 }
2211 if (atomic_read(&wrq->done)) {
2212 wrq->wq.func(&wrq->wq,
2213 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2214 0, NULL);
2215 }
2216 }
2217 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2218 }
2219
2220 /**
2221 * nilfs_construct_segment - construct a logical segment
2222 * @sb: super block
2223 *
2224 * Return Value: On success, 0 is retured. On errors, one of the following
2225 * negative error code is returned.
2226 *
2227 * %-EROFS - Read only filesystem.
2228 *
2229 * %-EIO - I/O error
2230 *
2231 * %-ENOSPC - No space left on device (only in a panic state).
2232 *
2233 * %-ERESTARTSYS - Interrupted.
2234 *
2235 * %-ENOMEM - Insufficient memory available.
2236 */
2237 int nilfs_construct_segment(struct super_block *sb)
2238 {
2239 struct the_nilfs *nilfs = sb->s_fs_info;
2240 struct nilfs_sc_info *sci = nilfs->ns_writer;
2241 struct nilfs_transaction_info *ti;
2242 int err;
2243
2244 if (!sci)
2245 return -EROFS;
2246
2247 /* A call inside transactions causes a deadlock. */
2248 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2249
2250 err = nilfs_segctor_sync(sci);
2251 return err;
2252 }
2253
2254 /**
2255 * nilfs_construct_dsync_segment - construct a data-only logical segment
2256 * @sb: super block
2257 * @inode: inode whose data blocks should be written out
2258 * @start: start byte offset
2259 * @end: end byte offset (inclusive)
2260 *
2261 * Return Value: On success, 0 is retured. On errors, one of the following
2262 * negative error code is returned.
2263 *
2264 * %-EROFS - Read only filesystem.
2265 *
2266 * %-EIO - I/O error
2267 *
2268 * %-ENOSPC - No space left on device (only in a panic state).
2269 *
2270 * %-ERESTARTSYS - Interrupted.
2271 *
2272 * %-ENOMEM - Insufficient memory available.
2273 */
2274 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2275 loff_t start, loff_t end)
2276 {
2277 struct the_nilfs *nilfs = sb->s_fs_info;
2278 struct nilfs_sc_info *sci = nilfs->ns_writer;
2279 struct nilfs_inode_info *ii;
2280 struct nilfs_transaction_info ti;
2281 int err = 0;
2282
2283 if (!sci)
2284 return -EROFS;
2285
2286 nilfs_transaction_lock(sb, &ti, 0);
2287
2288 ii = NILFS_I(inode);
2289 if (test_bit(NILFS_I_INODE_SYNC, &ii->i_state) ||
2290 nilfs_test_opt(nilfs, STRICT_ORDER) ||
2291 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2292 nilfs_discontinued(nilfs)) {
2293 nilfs_transaction_unlock(sb);
2294 err = nilfs_segctor_sync(sci);
2295 return err;
2296 }
2297
2298 spin_lock(&nilfs->ns_inode_lock);
2299 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2300 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2301 spin_unlock(&nilfs->ns_inode_lock);
2302 nilfs_transaction_unlock(sb);
2303 return 0;
2304 }
2305 spin_unlock(&nilfs->ns_inode_lock);
2306 sci->sc_dsync_inode = ii;
2307 sci->sc_dsync_start = start;
2308 sci->sc_dsync_end = end;
2309
2310 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2311 if (!err)
2312 nilfs->ns_flushed_device = 0;
2313
2314 nilfs_transaction_unlock(sb);
2315 return err;
2316 }
2317
2318 #define FLUSH_FILE_BIT (0x1) /* data file only */
2319 #define FLUSH_DAT_BIT BIT(NILFS_DAT_INO) /* DAT only */
2320
2321 /**
2322 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2323 * @sci: segment constructor object
2324 */
2325 static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2326 {
2327 spin_lock(&sci->sc_state_lock);
2328 sci->sc_seq_accepted = sci->sc_seq_request;
2329 spin_unlock(&sci->sc_state_lock);
2330 del_timer_sync(&sci->sc_timer);
2331 }
2332
2333 /**
2334 * nilfs_segctor_notify - notify the result of request to caller threads
2335 * @sci: segment constructor object
2336 * @mode: mode of log forming
2337 * @err: error code to be notified
2338 */
2339 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2340 {
2341 /* Clear requests (even when the construction failed) */
2342 spin_lock(&sci->sc_state_lock);
2343
2344 if (mode == SC_LSEG_SR) {
2345 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2346 sci->sc_seq_done = sci->sc_seq_accepted;
2347 nilfs_segctor_wakeup(sci, err);
2348 sci->sc_flush_request = 0;
2349 } else {
2350 if (mode == SC_FLUSH_FILE)
2351 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2352 else if (mode == SC_FLUSH_DAT)
2353 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2354
2355 /* re-enable timer if checkpoint creation was not done */
2356 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2357 time_before(jiffies, sci->sc_timer.expires))
2358 add_timer(&sci->sc_timer);
2359 }
2360 spin_unlock(&sci->sc_state_lock);
2361 }
2362
2363 /**
2364 * nilfs_segctor_construct - form logs and write them to disk
2365 * @sci: segment constructor object
2366 * @mode: mode of log forming
2367 */
2368 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2369 {
2370 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2371 struct nilfs_super_block **sbp;
2372 int err = 0;
2373
2374 nilfs_segctor_accept(sci);
2375
2376 if (nilfs_discontinued(nilfs))
2377 mode = SC_LSEG_SR;
2378 if (!nilfs_segctor_confirm(sci))
2379 err = nilfs_segctor_do_construct(sci, mode);
2380
2381 if (likely(!err)) {
2382 if (mode != SC_FLUSH_DAT)
2383 atomic_set(&nilfs->ns_ndirtyblks, 0);
2384 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2385 nilfs_discontinued(nilfs)) {
2386 down_write(&nilfs->ns_sem);
2387 err = -EIO;
2388 sbp = nilfs_prepare_super(sci->sc_super,
2389 nilfs_sb_will_flip(nilfs));
2390 if (likely(sbp)) {
2391 nilfs_set_log_cursor(sbp[0], nilfs);
2392 err = nilfs_commit_super(sci->sc_super,
2393 NILFS_SB_COMMIT);
2394 }
2395 up_write(&nilfs->ns_sem);
2396 }
2397 }
2398
2399 nilfs_segctor_notify(sci, mode, err);
2400 return err;
2401 }
2402
2403 static void nilfs_construction_timeout(struct timer_list *t)
2404 {
2405 struct nilfs_sc_info *sci = from_timer(sci, t, sc_timer);
2406
2407 wake_up_process(sci->sc_timer_task);
2408 }
2409
2410 static void
2411 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2412 {
2413 struct nilfs_inode_info *ii, *n;
2414
2415 list_for_each_entry_safe(ii, n, head, i_dirty) {
2416 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2417 continue;
2418 list_del_init(&ii->i_dirty);
2419 truncate_inode_pages(&ii->vfs_inode.i_data, 0);
2420 nilfs_btnode_cache_clear(&ii->i_btnode_cache);
2421 iput(&ii->vfs_inode);
2422 }
2423 }
2424
2425 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2426 void **kbufs)
2427 {
2428 struct the_nilfs *nilfs = sb->s_fs_info;
2429 struct nilfs_sc_info *sci = nilfs->ns_writer;
2430 struct nilfs_transaction_info ti;
2431 int err;
2432
2433 if (unlikely(!sci))
2434 return -EROFS;
2435
2436 nilfs_transaction_lock(sb, &ti, 1);
2437
2438 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2439 if (unlikely(err))
2440 goto out_unlock;
2441
2442 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2443 if (unlikely(err)) {
2444 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2445 goto out_unlock;
2446 }
2447
2448 sci->sc_freesegs = kbufs[4];
2449 sci->sc_nfreesegs = argv[4].v_nmembs;
2450 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2451
2452 for (;;) {
2453 err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2454 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2455
2456 if (likely(!err))
2457 break;
2458
2459 nilfs_msg(sb, KERN_WARNING, "error %d cleaning segments", err);
2460 set_current_state(TASK_INTERRUPTIBLE);
2461 schedule_timeout(sci->sc_interval);
2462 }
2463 if (nilfs_test_opt(nilfs, DISCARD)) {
2464 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2465 sci->sc_nfreesegs);
2466 if (ret) {
2467 nilfs_msg(sb, KERN_WARNING,
2468 "error %d on discard request, turning discards off for the device",
2469 ret);
2470 nilfs_clear_opt(nilfs, DISCARD);
2471 }
2472 }
2473
2474 out_unlock:
2475 sci->sc_freesegs = NULL;
2476 sci->sc_nfreesegs = 0;
2477 nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2478 nilfs_transaction_unlock(sb);
2479 return err;
2480 }
2481
2482 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2483 {
2484 struct nilfs_transaction_info ti;
2485
2486 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2487 nilfs_segctor_construct(sci, mode);
2488
2489 /*
2490 * Unclosed segment should be retried. We do this using sc_timer.
2491 * Timeout of sc_timer will invoke complete construction which leads
2492 * to close the current logical segment.
2493 */
2494 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2495 nilfs_segctor_start_timer(sci);
2496
2497 nilfs_transaction_unlock(sci->sc_super);
2498 }
2499
2500 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2501 {
2502 int mode = 0;
2503
2504 spin_lock(&sci->sc_state_lock);
2505 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2506 SC_FLUSH_DAT : SC_FLUSH_FILE;
2507 spin_unlock(&sci->sc_state_lock);
2508
2509 if (mode) {
2510 nilfs_segctor_do_construct(sci, mode);
2511
2512 spin_lock(&sci->sc_state_lock);
2513 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2514 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2515 spin_unlock(&sci->sc_state_lock);
2516 }
2517 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2518 }
2519
2520 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2521 {
2522 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2523 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2524 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2525 return SC_FLUSH_FILE;
2526 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2527 return SC_FLUSH_DAT;
2528 }
2529 return SC_LSEG_SR;
2530 }
2531
2532 /**
2533 * nilfs_segctor_thread - main loop of the segment constructor thread.
2534 * @arg: pointer to a struct nilfs_sc_info.
2535 *
2536 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2537 * to execute segment constructions.
2538 */
2539 static int nilfs_segctor_thread(void *arg)
2540 {
2541 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2542 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2543 int timeout = 0;
2544
2545 sci->sc_timer_task = current;
2546
2547 /* start sync. */
2548 sci->sc_task = current;
2549 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2550 nilfs_msg(sci->sc_super, KERN_INFO,
2551 "segctord starting. Construction interval = %lu seconds, CP frequency < %lu seconds",
2552 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2553
2554 spin_lock(&sci->sc_state_lock);
2555 loop:
2556 for (;;) {
2557 int mode;
2558
2559 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2560 goto end_thread;
2561
2562 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2563 mode = SC_LSEG_SR;
2564 else if (sci->sc_flush_request)
2565 mode = nilfs_segctor_flush_mode(sci);
2566 else
2567 break;
2568
2569 spin_unlock(&sci->sc_state_lock);
2570 nilfs_segctor_thread_construct(sci, mode);
2571 spin_lock(&sci->sc_state_lock);
2572 timeout = 0;
2573 }
2574
2575
2576 if (freezing(current)) {
2577 spin_unlock(&sci->sc_state_lock);
2578 try_to_freeze();
2579 spin_lock(&sci->sc_state_lock);
2580 } else {
2581 DEFINE_WAIT(wait);
2582 int should_sleep = 1;
2583
2584 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2585 TASK_INTERRUPTIBLE);
2586
2587 if (sci->sc_seq_request != sci->sc_seq_done)
2588 should_sleep = 0;
2589 else if (sci->sc_flush_request)
2590 should_sleep = 0;
2591 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2592 should_sleep = time_before(jiffies,
2593 sci->sc_timer.expires);
2594
2595 if (should_sleep) {
2596 spin_unlock(&sci->sc_state_lock);
2597 schedule();
2598 spin_lock(&sci->sc_state_lock);
2599 }
2600 finish_wait(&sci->sc_wait_daemon, &wait);
2601 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2602 time_after_eq(jiffies, sci->sc_timer.expires));
2603
2604 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2605 set_nilfs_discontinued(nilfs);
2606 }
2607 goto loop;
2608
2609 end_thread:
2610 spin_unlock(&sci->sc_state_lock);
2611
2612 /* end sync. */
2613 sci->sc_task = NULL;
2614 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2615 return 0;
2616 }
2617
2618 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2619 {
2620 struct task_struct *t;
2621
2622 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2623 if (IS_ERR(t)) {
2624 int err = PTR_ERR(t);
2625
2626 nilfs_msg(sci->sc_super, KERN_ERR,
2627 "error %d creating segctord thread", err);
2628 return err;
2629 }
2630 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2631 return 0;
2632 }
2633
2634 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2635 __acquires(&sci->sc_state_lock)
2636 __releases(&sci->sc_state_lock)
2637 {
2638 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2639
2640 while (sci->sc_task) {
2641 wake_up(&sci->sc_wait_daemon);
2642 spin_unlock(&sci->sc_state_lock);
2643 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2644 spin_lock(&sci->sc_state_lock);
2645 }
2646 }
2647
2648 /*
2649 * Setup & clean-up functions
2650 */
2651 static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
2652 struct nilfs_root *root)
2653 {
2654 struct the_nilfs *nilfs = sb->s_fs_info;
2655 struct nilfs_sc_info *sci;
2656
2657 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2658 if (!sci)
2659 return NULL;
2660
2661 sci->sc_super = sb;
2662
2663 nilfs_get_root(root);
2664 sci->sc_root = root;
2665
2666 init_waitqueue_head(&sci->sc_wait_request);
2667 init_waitqueue_head(&sci->sc_wait_daemon);
2668 init_waitqueue_head(&sci->sc_wait_task);
2669 spin_lock_init(&sci->sc_state_lock);
2670 INIT_LIST_HEAD(&sci->sc_dirty_files);
2671 INIT_LIST_HEAD(&sci->sc_segbufs);
2672 INIT_LIST_HEAD(&sci->sc_write_logs);
2673 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2674 INIT_LIST_HEAD(&sci->sc_iput_queue);
2675 INIT_WORK(&sci->sc_iput_work, nilfs_iput_work_func);
2676 timer_setup(&sci->sc_timer, nilfs_construction_timeout, 0);
2677
2678 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2679 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2680 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2681
2682 if (nilfs->ns_interval)
2683 sci->sc_interval = HZ * nilfs->ns_interval;
2684 if (nilfs->ns_watermark)
2685 sci->sc_watermark = nilfs->ns_watermark;
2686 return sci;
2687 }
2688
2689 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2690 {
2691 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2692
2693 /*
2694 * The segctord thread was stopped and its timer was removed.
2695 * But some tasks remain.
2696 */
2697 do {
2698 struct nilfs_transaction_info ti;
2699
2700 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2701 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2702 nilfs_transaction_unlock(sci->sc_super);
2703
2704 flush_work(&sci->sc_iput_work);
2705
2706 } while (ret && retrycount-- > 0);
2707 }
2708
2709 /**
2710 * nilfs_segctor_destroy - destroy the segment constructor.
2711 * @sci: nilfs_sc_info
2712 *
2713 * nilfs_segctor_destroy() kills the segctord thread and frees
2714 * the nilfs_sc_info struct.
2715 * Caller must hold the segment semaphore.
2716 */
2717 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2718 {
2719 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2720 int flag;
2721
2722 up_write(&nilfs->ns_segctor_sem);
2723
2724 spin_lock(&sci->sc_state_lock);
2725 nilfs_segctor_kill_thread(sci);
2726 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2727 || sci->sc_seq_request != sci->sc_seq_done);
2728 spin_unlock(&sci->sc_state_lock);
2729
2730 if (flush_work(&sci->sc_iput_work))
2731 flag = true;
2732
2733 if (flag || !nilfs_segctor_confirm(sci))
2734 nilfs_segctor_write_out(sci);
2735
2736 if (!list_empty(&sci->sc_dirty_files)) {
2737 nilfs_msg(sci->sc_super, KERN_WARNING,
2738 "disposed unprocessed dirty file(s) when stopping log writer");
2739 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
2740 }
2741
2742 if (!list_empty(&sci->sc_iput_queue)) {
2743 nilfs_msg(sci->sc_super, KERN_WARNING,
2744 "disposed unprocessed inode(s) in iput queue when stopping log writer");
2745 nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 1);
2746 }
2747
2748 WARN_ON(!list_empty(&sci->sc_segbufs));
2749 WARN_ON(!list_empty(&sci->sc_write_logs));
2750
2751 nilfs_put_root(sci->sc_root);
2752
2753 down_write(&nilfs->ns_segctor_sem);
2754
2755 del_timer_sync(&sci->sc_timer);
2756 kfree(sci);
2757 }
2758
2759 /**
2760 * nilfs_attach_log_writer - attach log writer
2761 * @sb: super block instance
2762 * @root: root object of the current filesystem tree
2763 *
2764 * This allocates a log writer object, initializes it, and starts the
2765 * log writer.
2766 *
2767 * Return Value: On success, 0 is returned. On error, one of the following
2768 * negative error code is returned.
2769 *
2770 * %-ENOMEM - Insufficient memory available.
2771 */
2772 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
2773 {
2774 struct the_nilfs *nilfs = sb->s_fs_info;
2775 int err;
2776
2777 if (nilfs->ns_writer) {
2778 /*
2779 * This happens if the filesystem was remounted
2780 * read/write after nilfs_error degenerated it into a
2781 * read-only mount.
2782 */
2783 nilfs_detach_log_writer(sb);
2784 }
2785
2786 nilfs->ns_writer = nilfs_segctor_new(sb, root);
2787 if (!nilfs->ns_writer)
2788 return -ENOMEM;
2789
2790 err = nilfs_segctor_start_thread(nilfs->ns_writer);
2791 if (err) {
2792 kfree(nilfs->ns_writer);
2793 nilfs->ns_writer = NULL;
2794 }
2795 return err;
2796 }
2797
2798 /**
2799 * nilfs_detach_log_writer - destroy log writer
2800 * @sb: super block instance
2801 *
2802 * This kills log writer daemon, frees the log writer object, and
2803 * destroys list of dirty files.
2804 */
2805 void nilfs_detach_log_writer(struct super_block *sb)
2806 {
2807 struct the_nilfs *nilfs = sb->s_fs_info;
2808 LIST_HEAD(garbage_list);
2809
2810 down_write(&nilfs->ns_segctor_sem);
2811 if (nilfs->ns_writer) {
2812 nilfs_segctor_destroy(nilfs->ns_writer);
2813 nilfs->ns_writer = NULL;
2814 }
2815
2816 /* Force to free the list of dirty files */
2817 spin_lock(&nilfs->ns_inode_lock);
2818 if (!list_empty(&nilfs->ns_dirty_files)) {
2819 list_splice_init(&nilfs->ns_dirty_files, &garbage_list);
2820 nilfs_msg(sb, KERN_WARNING,
2821 "disposed unprocessed dirty file(s) when detaching log writer");
2822 }
2823 spin_unlock(&nilfs->ns_inode_lock);
2824 up_write(&nilfs->ns_segctor_sem);
2825
2826 nilfs_dispose_list(nilfs, &garbage_list, 1);
2827 }
(deprecated) Btrfs devel tree