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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 */
56enum {
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 */
73enum {
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 */
99static 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
105static 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
111static 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 */
123struct 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 */
141static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
142static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
143static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
144static 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
155static 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 */
215int 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 */
270int 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
306void 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
329void 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
352static 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
387static 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
402static 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 */
425static 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
447static 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
459static 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 */
479static 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
491static 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
505static 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
539static 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 */
577static 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
593static 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
600static 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
608static 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
617static 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
626static 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
634static 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
649static 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
657static 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
666static 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
675static 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
683static 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
691static 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
746static 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
777static 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
810static 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
819static 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
835static 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
843static 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
859static 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
869static 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
895static 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
933static 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
950static 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
960static 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
987static 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
997static 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
1010static 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
1041static 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
1048static 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
1101static 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
1122static 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 */
1282static 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
1342static 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
1398static 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
1437static 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
1454static 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
1472static 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
1488static 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
1541static 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
1550static int
1551nilfs_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
1623static 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
1637static 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
1652static 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
1701static 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
1711static 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
1749static 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
1790static 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
1815static 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
1826static 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
1923static 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
1935static 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 spin_lock(&nilfs->ns_inode_lock);
1958 if (likely(!ii->i_bh))
1959 ii->i_bh = ibh;
1960 else
1961 brelse(ibh);
1962 goto retry;
1963 }
1964
1965 // Always redirty the buffer to avoid race condition
1966 mark_buffer_dirty(ii->i_bh);
1967 nilfs_mdt_mark_dirty(ifile);
1968
1969 clear_bit(NILFS_I_QUEUED, &ii->i_state);
1970 set_bit(NILFS_I_BUSY, &ii->i_state);
1971 list_move_tail(&ii->i_dirty, &sci->sc_dirty_files);
1972 }
1973 spin_unlock(&nilfs->ns_inode_lock);
1974
1975 return 0;
1976}
1977
1978static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
1979 struct the_nilfs *nilfs)
1980{
1981 struct nilfs_inode_info *ii, *n;
1982 int during_mount = !(sci->sc_super->s_flags & SB_ACTIVE);
1983 int defer_iput = false;
1984
1985 spin_lock(&nilfs->ns_inode_lock);
1986 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
1987 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
1988 test_bit(NILFS_I_DIRTY, &ii->i_state))
1989 continue;
1990
1991 clear_bit(NILFS_I_BUSY, &ii->i_state);
1992 brelse(ii->i_bh);
1993 ii->i_bh = NULL;
1994 list_del_init(&ii->i_dirty);
1995 if (!ii->vfs_inode.i_nlink || during_mount) {
1996 /*
1997 * Defer calling iput() to avoid deadlocks if
1998 * i_nlink == 0 or mount is not yet finished.
1999 */
2000 list_add_tail(&ii->i_dirty, &sci->sc_iput_queue);
2001 defer_iput = true;
2002 } else {
2003 spin_unlock(&nilfs->ns_inode_lock);
2004 iput(&ii->vfs_inode);
2005 spin_lock(&nilfs->ns_inode_lock);
2006 }
2007 }
2008 spin_unlock(&nilfs->ns_inode_lock);
2009
2010 if (defer_iput)
2011 schedule_work(&sci->sc_iput_work);
2012}
2013
2014/*
2015 * Main procedure of segment constructor
2016 */
2017static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2018{
2019 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2020 int err;
2021
2022 nilfs_sc_cstage_set(sci, NILFS_ST_INIT);
2023 sci->sc_cno = nilfs->ns_cno;
2024
2025 err = nilfs_segctor_collect_dirty_files(sci, nilfs);
2026 if (unlikely(err))
2027 goto out;
2028
2029 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
2030 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2031
2032 if (nilfs_segctor_clean(sci))
2033 goto out;
2034
2035 do {
2036 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2037
2038 err = nilfs_segctor_begin_construction(sci, nilfs);
2039 if (unlikely(err))
2040 goto out;
2041
2042 /* Update time stamp */
2043 sci->sc_seg_ctime = ktime_get_real_seconds();
2044
2045 err = nilfs_segctor_collect(sci, nilfs, mode);
2046 if (unlikely(err))
2047 goto failed;
2048
2049 /* Avoid empty segment */
2050 if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE &&
2051 nilfs_segbuf_empty(sci->sc_curseg)) {
2052 nilfs_segctor_abort_construction(sci, nilfs, 1);
2053 goto out;
2054 }
2055
2056 err = nilfs_segctor_assign(sci, mode);
2057 if (unlikely(err))
2058 goto failed;
2059
2060 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2061 nilfs_segctor_fill_in_file_bmap(sci);
2062
2063 if (mode == SC_LSEG_SR &&
2064 nilfs_sc_cstage_get(sci) >= NILFS_ST_CPFILE) {
2065 err = nilfs_segctor_fill_in_checkpoint(sci);
2066 if (unlikely(err))
2067 goto failed_to_write;
2068
2069 nilfs_segctor_fill_in_super_root(sci, nilfs);
2070 }
2071 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2072
2073 /* Write partial segments */
2074 nilfs_segctor_prepare_write(sci);
2075
2076 nilfs_add_checksums_on_logs(&sci->sc_segbufs,
2077 nilfs->ns_crc_seed);
2078
2079 err = nilfs_segctor_write(sci, nilfs);
2080 if (unlikely(err))
2081 goto failed_to_write;
2082
2083 if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE ||
2084 nilfs->ns_blocksize_bits != PAGE_SHIFT) {
2085 /*
2086 * At this point, we avoid double buffering
2087 * for blocksize < pagesize because page dirty
2088 * flag is turned off during write and dirty
2089 * buffers are not properly collected for
2090 * pages crossing over segments.
2091 */
2092 err = nilfs_segctor_wait(sci);
2093 if (err)
2094 goto failed_to_write;
2095 }
2096 } while (nilfs_sc_cstage_get(sci) != NILFS_ST_DONE);
2097
2098 out:
2099 nilfs_segctor_drop_written_files(sci, nilfs);
2100 return err;
2101
2102 failed_to_write:
2103 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2104 nilfs_redirty_inodes(&sci->sc_dirty_files);
2105
2106 failed:
2107 if (nilfs_doing_gc())
2108 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2109 nilfs_segctor_abort_construction(sci, nilfs, err);
2110 goto out;
2111}
2112
2113/**
2114 * nilfs_segctor_start_timer - set timer of background write
2115 * @sci: nilfs_sc_info
2116 *
2117 * If the timer has already been set, it ignores the new request.
2118 * This function MUST be called within a section locking the segment
2119 * semaphore.
2120 */
2121static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2122{
2123 spin_lock(&sci->sc_state_lock);
2124 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2125 sci->sc_timer.expires = jiffies + sci->sc_interval;
2126 add_timer(&sci->sc_timer);
2127 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2128 }
2129 spin_unlock(&sci->sc_state_lock);
2130}
2131
2132static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2133{
2134 spin_lock(&sci->sc_state_lock);
2135 if (!(sci->sc_flush_request & BIT(bn))) {
2136 unsigned long prev_req = sci->sc_flush_request;
2137
2138 sci->sc_flush_request |= BIT(bn);
2139 if (!prev_req)
2140 wake_up(&sci->sc_wait_daemon);
2141 }
2142 spin_unlock(&sci->sc_state_lock);
2143}
2144
2145/**
2146 * nilfs_flush_segment - trigger a segment construction for resource control
2147 * @sb: super block
2148 * @ino: inode number of the file to be flushed out.
2149 */
2150void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2151{
2152 struct the_nilfs *nilfs = sb->s_fs_info;
2153 struct nilfs_sc_info *sci = nilfs->ns_writer;
2154
2155 if (!sci || nilfs_doing_construction())
2156 return;
2157 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2158 /* assign bit 0 to data files */
2159}
2160
2161struct nilfs_segctor_wait_request {
2162 wait_queue_entry_t wq;
2163 __u32 seq;
2164 int err;
2165 atomic_t done;
2166};
2167
2168static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2169{
2170 struct nilfs_segctor_wait_request wait_req;
2171 int err = 0;
2172
2173 spin_lock(&sci->sc_state_lock);
2174 init_wait(&wait_req.wq);
2175 wait_req.err = 0;
2176 atomic_set(&wait_req.done, 0);
2177 wait_req.seq = ++sci->sc_seq_request;
2178 spin_unlock(&sci->sc_state_lock);
2179
2180 init_waitqueue_entry(&wait_req.wq, current);
2181 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2182 set_current_state(TASK_INTERRUPTIBLE);
2183 wake_up(&sci->sc_wait_daemon);
2184
2185 for (;;) {
2186 if (atomic_read(&wait_req.done)) {
2187 err = wait_req.err;
2188 break;
2189 }
2190 if (!signal_pending(current)) {
2191 schedule();
2192 continue;
2193 }
2194 err = -ERESTARTSYS;
2195 break;
2196 }
2197 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2198 return err;
2199}
2200
2201static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2202{
2203 struct nilfs_segctor_wait_request *wrq, *n;
2204 unsigned long flags;
2205
2206 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2207 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.head, wq.entry) {
2208 if (!atomic_read(&wrq->done) &&
2209 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2210 wrq->err = err;
2211 atomic_set(&wrq->done, 1);
2212 }
2213 if (atomic_read(&wrq->done)) {
2214 wrq->wq.func(&wrq->wq,
2215 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2216 0, NULL);
2217 }
2218 }
2219 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2220}
2221
2222/**
2223 * nilfs_construct_segment - construct a logical segment
2224 * @sb: super block
2225 *
2226 * Return Value: On success, 0 is retured. On errors, one of the following
2227 * negative error code is returned.
2228 *
2229 * %-EROFS - Read only filesystem.
2230 *
2231 * %-EIO - I/O error
2232 *
2233 * %-ENOSPC - No space left on device (only in a panic state).
2234 *
2235 * %-ERESTARTSYS - Interrupted.
2236 *
2237 * %-ENOMEM - Insufficient memory available.
2238 */
2239int nilfs_construct_segment(struct super_block *sb)
2240{
2241 struct the_nilfs *nilfs = sb->s_fs_info;
2242 struct nilfs_sc_info *sci = nilfs->ns_writer;
2243 struct nilfs_transaction_info *ti;
2244 int err;
2245
2246 if (!sci)
2247 return -EROFS;
2248
2249 /* A call inside transactions causes a deadlock. */
2250 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2251
2252 err = nilfs_segctor_sync(sci);
2253 return err;
2254}
2255
2256/**
2257 * nilfs_construct_dsync_segment - construct a data-only logical segment
2258 * @sb: super block
2259 * @inode: inode whose data blocks should be written out
2260 * @start: start byte offset
2261 * @end: end byte offset (inclusive)
2262 *
2263 * Return Value: On success, 0 is retured. On errors, one of the following
2264 * negative error code is returned.
2265 *
2266 * %-EROFS - Read only filesystem.
2267 *
2268 * %-EIO - I/O error
2269 *
2270 * %-ENOSPC - No space left on device (only in a panic state).
2271 *
2272 * %-ERESTARTSYS - Interrupted.
2273 *
2274 * %-ENOMEM - Insufficient memory available.
2275 */
2276int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2277 loff_t start, loff_t end)
2278{
2279 struct the_nilfs *nilfs = sb->s_fs_info;
2280 struct nilfs_sc_info *sci = nilfs->ns_writer;
2281 struct nilfs_inode_info *ii;
2282 struct nilfs_transaction_info ti;
2283 int err = 0;
2284
2285 if (!sci)
2286 return -EROFS;
2287
2288 nilfs_transaction_lock(sb, &ti, 0);
2289
2290 ii = NILFS_I(inode);
2291 if (test_bit(NILFS_I_INODE_SYNC, &ii->i_state) ||
2292 nilfs_test_opt(nilfs, STRICT_ORDER) ||
2293 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2294 nilfs_discontinued(nilfs)) {
2295 nilfs_transaction_unlock(sb);
2296 err = nilfs_segctor_sync(sci);
2297 return err;
2298 }
2299
2300 spin_lock(&nilfs->ns_inode_lock);
2301 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2302 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2303 spin_unlock(&nilfs->ns_inode_lock);
2304 nilfs_transaction_unlock(sb);
2305 return 0;
2306 }
2307 spin_unlock(&nilfs->ns_inode_lock);
2308 sci->sc_dsync_inode = ii;
2309 sci->sc_dsync_start = start;
2310 sci->sc_dsync_end = end;
2311
2312 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2313 if (!err)
2314 nilfs->ns_flushed_device = 0;
2315
2316 nilfs_transaction_unlock(sb);
2317 return err;
2318}
2319
2320#define FLUSH_FILE_BIT (0x1) /* data file only */
2321#define FLUSH_DAT_BIT BIT(NILFS_DAT_INO) /* DAT only */
2322
2323/**
2324 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2325 * @sci: segment constructor object
2326 */
2327static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2328{
2329 spin_lock(&sci->sc_state_lock);
2330 sci->sc_seq_accepted = sci->sc_seq_request;
2331 spin_unlock(&sci->sc_state_lock);
2332 del_timer_sync(&sci->sc_timer);
2333}
2334
2335/**
2336 * nilfs_segctor_notify - notify the result of request to caller threads
2337 * @sci: segment constructor object
2338 * @mode: mode of log forming
2339 * @err: error code to be notified
2340 */
2341static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2342{
2343 /* Clear requests (even when the construction failed) */
2344 spin_lock(&sci->sc_state_lock);
2345
2346 if (mode == SC_LSEG_SR) {
2347 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2348 sci->sc_seq_done = sci->sc_seq_accepted;
2349 nilfs_segctor_wakeup(sci, err);
2350 sci->sc_flush_request = 0;
2351 } else {
2352 if (mode == SC_FLUSH_FILE)
2353 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2354 else if (mode == SC_FLUSH_DAT)
2355 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2356
2357 /* re-enable timer if checkpoint creation was not done */
2358 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2359 time_before(jiffies, sci->sc_timer.expires))
2360 add_timer(&sci->sc_timer);
2361 }
2362 spin_unlock(&sci->sc_state_lock);
2363}
2364
2365/**
2366 * nilfs_segctor_construct - form logs and write them to disk
2367 * @sci: segment constructor object
2368 * @mode: mode of log forming
2369 */
2370static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2371{
2372 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2373 struct nilfs_super_block **sbp;
2374 int err = 0;
2375
2376 nilfs_segctor_accept(sci);
2377
2378 if (nilfs_discontinued(nilfs))
2379 mode = SC_LSEG_SR;
2380 if (!nilfs_segctor_confirm(sci))
2381 err = nilfs_segctor_do_construct(sci, mode);
2382
2383 if (likely(!err)) {
2384 if (mode != SC_FLUSH_DAT)
2385 atomic_set(&nilfs->ns_ndirtyblks, 0);
2386 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2387 nilfs_discontinued(nilfs)) {
2388 down_write(&nilfs->ns_sem);
2389 err = -EIO;
2390 sbp = nilfs_prepare_super(sci->sc_super,
2391 nilfs_sb_will_flip(nilfs));
2392 if (likely(sbp)) {
2393 nilfs_set_log_cursor(sbp[0], nilfs);
2394 err = nilfs_commit_super(sci->sc_super,
2395 NILFS_SB_COMMIT);
2396 }
2397 up_write(&nilfs->ns_sem);
2398 }
2399 }
2400
2401 nilfs_segctor_notify(sci, mode, err);
2402 return err;
2403}
2404
2405static void nilfs_construction_timeout(struct timer_list *t)
2406{
2407 struct nilfs_sc_info *sci = from_timer(sci, t, sc_timer);
2408
2409 wake_up_process(sci->sc_timer_task);
2410}
2411
2412static void
2413nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2414{
2415 struct nilfs_inode_info *ii, *n;
2416
2417 list_for_each_entry_safe(ii, n, head, i_dirty) {
2418 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2419 continue;
2420 list_del_init(&ii->i_dirty);
2421 truncate_inode_pages(&ii->vfs_inode.i_data, 0);
2422 nilfs_btnode_cache_clear(&ii->i_btnode_cache);
2423 iput(&ii->vfs_inode);
2424 }
2425}
2426
2427int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2428 void **kbufs)
2429{
2430 struct the_nilfs *nilfs = sb->s_fs_info;
2431 struct nilfs_sc_info *sci = nilfs->ns_writer;
2432 struct nilfs_transaction_info ti;
2433 int err;
2434
2435 if (unlikely(!sci))
2436 return -EROFS;
2437
2438 nilfs_transaction_lock(sb, &ti, 1);
2439
2440 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2441 if (unlikely(err))
2442 goto out_unlock;
2443
2444 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2445 if (unlikely(err)) {
2446 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2447 goto out_unlock;
2448 }
2449
2450 sci->sc_freesegs = kbufs[4];
2451 sci->sc_nfreesegs = argv[4].v_nmembs;
2452 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2453
2454 for (;;) {
2455 err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2456 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2457
2458 if (likely(!err))
2459 break;
2460
2461 nilfs_msg(sb, KERN_WARNING, "error %d cleaning segments", err);
2462 set_current_state(TASK_INTERRUPTIBLE);
2463 schedule_timeout(sci->sc_interval);
2464 }
2465 if (nilfs_test_opt(nilfs, DISCARD)) {
2466 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2467 sci->sc_nfreesegs);
2468 if (ret) {
2469 nilfs_msg(sb, KERN_WARNING,
2470 "error %d on discard request, turning discards off for the device",
2471 ret);
2472 nilfs_clear_opt(nilfs, DISCARD);
2473 }
2474 }
2475
2476 out_unlock:
2477 sci->sc_freesegs = NULL;
2478 sci->sc_nfreesegs = 0;
2479 nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2480 nilfs_transaction_unlock(sb);
2481 return err;
2482}
2483
2484static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2485{
2486 struct nilfs_transaction_info ti;
2487
2488 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2489 nilfs_segctor_construct(sci, mode);
2490
2491 /*
2492 * Unclosed segment should be retried. We do this using sc_timer.
2493 * Timeout of sc_timer will invoke complete construction which leads
2494 * to close the current logical segment.
2495 */
2496 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2497 nilfs_segctor_start_timer(sci);
2498
2499 nilfs_transaction_unlock(sci->sc_super);
2500}
2501
2502static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2503{
2504 int mode = 0;
2505
2506 spin_lock(&sci->sc_state_lock);
2507 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2508 SC_FLUSH_DAT : SC_FLUSH_FILE;
2509 spin_unlock(&sci->sc_state_lock);
2510
2511 if (mode) {
2512 nilfs_segctor_do_construct(sci, mode);
2513
2514 spin_lock(&sci->sc_state_lock);
2515 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2516 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2517 spin_unlock(&sci->sc_state_lock);
2518 }
2519 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2520}
2521
2522static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2523{
2524 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2525 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2526 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2527 return SC_FLUSH_FILE;
2528 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2529 return SC_FLUSH_DAT;
2530 }
2531 return SC_LSEG_SR;
2532}
2533
2534/**
2535 * nilfs_segctor_thread - main loop of the segment constructor thread.
2536 * @arg: pointer to a struct nilfs_sc_info.
2537 *
2538 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2539 * to execute segment constructions.
2540 */
2541static int nilfs_segctor_thread(void *arg)
2542{
2543 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2544 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2545 int timeout = 0;
2546
2547 sci->sc_timer_task = current;
2548
2549 /* start sync. */
2550 sci->sc_task = current;
2551 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2552 nilfs_msg(sci->sc_super, KERN_INFO,
2553 "segctord starting. Construction interval = %lu seconds, CP frequency < %lu seconds",
2554 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2555
2556 spin_lock(&sci->sc_state_lock);
2557 loop:
2558 for (;;) {
2559 int mode;
2560
2561 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2562 goto end_thread;
2563
2564 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2565 mode = SC_LSEG_SR;
2566 else if (sci->sc_flush_request)
2567 mode = nilfs_segctor_flush_mode(sci);
2568 else
2569 break;
2570
2571 spin_unlock(&sci->sc_state_lock);
2572 nilfs_segctor_thread_construct(sci, mode);
2573 spin_lock(&sci->sc_state_lock);
2574 timeout = 0;
2575 }
2576
2577
2578 if (freezing(current)) {
2579 spin_unlock(&sci->sc_state_lock);
2580 try_to_freeze();
2581 spin_lock(&sci->sc_state_lock);
2582 } else {
2583 DEFINE_WAIT(wait);
2584 int should_sleep = 1;
2585
2586 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2587 TASK_INTERRUPTIBLE);
2588
2589 if (sci->sc_seq_request != sci->sc_seq_done)
2590 should_sleep = 0;
2591 else if (sci->sc_flush_request)
2592 should_sleep = 0;
2593 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2594 should_sleep = time_before(jiffies,
2595 sci->sc_timer.expires);
2596
2597 if (should_sleep) {
2598 spin_unlock(&sci->sc_state_lock);
2599 schedule();
2600 spin_lock(&sci->sc_state_lock);
2601 }
2602 finish_wait(&sci->sc_wait_daemon, &wait);
2603 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2604 time_after_eq(jiffies, sci->sc_timer.expires));
2605
2606 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2607 set_nilfs_discontinued(nilfs);
2608 }
2609 goto loop;
2610
2611 end_thread:
2612 spin_unlock(&sci->sc_state_lock);
2613
2614 /* end sync. */
2615 sci->sc_task = NULL;
2616 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2617 return 0;
2618}
2619
2620static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2621{
2622 struct task_struct *t;
2623
2624 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2625 if (IS_ERR(t)) {
2626 int err = PTR_ERR(t);
2627
2628 nilfs_msg(sci->sc_super, KERN_ERR,
2629 "error %d creating segctord thread", err);
2630 return err;
2631 }
2632 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2633 return 0;
2634}
2635
2636static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2637 __acquires(&sci->sc_state_lock)
2638 __releases(&sci->sc_state_lock)
2639{
2640 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2641
2642 while (sci->sc_task) {
2643 wake_up(&sci->sc_wait_daemon);
2644 spin_unlock(&sci->sc_state_lock);
2645 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2646 spin_lock(&sci->sc_state_lock);
2647 }
2648}
2649
2650/*
2651 * Setup & clean-up functions
2652 */
2653static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
2654 struct nilfs_root *root)
2655{
2656 struct the_nilfs *nilfs = sb->s_fs_info;
2657 struct nilfs_sc_info *sci;
2658
2659 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2660 if (!sci)
2661 return NULL;
2662
2663 sci->sc_super = sb;
2664
2665 nilfs_get_root(root);
2666 sci->sc_root = root;
2667
2668 init_waitqueue_head(&sci->sc_wait_request);
2669 init_waitqueue_head(&sci->sc_wait_daemon);
2670 init_waitqueue_head(&sci->sc_wait_task);
2671 spin_lock_init(&sci->sc_state_lock);
2672 INIT_LIST_HEAD(&sci->sc_dirty_files);
2673 INIT_LIST_HEAD(&sci->sc_segbufs);
2674 INIT_LIST_HEAD(&sci->sc_write_logs);
2675 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2676 INIT_LIST_HEAD(&sci->sc_iput_queue);
2677 INIT_WORK(&sci->sc_iput_work, nilfs_iput_work_func);
2678 timer_setup(&sci->sc_timer, nilfs_construction_timeout, 0);
2679
2680 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2681 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2682 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2683
2684 if (nilfs->ns_interval)
2685 sci->sc_interval = HZ * nilfs->ns_interval;
2686 if (nilfs->ns_watermark)
2687 sci->sc_watermark = nilfs->ns_watermark;
2688 return sci;
2689}
2690
2691static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2692{
2693 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2694
2695 /*
2696 * The segctord thread was stopped and its timer was removed.
2697 * But some tasks remain.
2698 */
2699 do {
2700 struct nilfs_transaction_info ti;
2701
2702 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2703 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2704 nilfs_transaction_unlock(sci->sc_super);
2705
2706 flush_work(&sci->sc_iput_work);
2707
2708 } while (ret && retrycount-- > 0);
2709}
2710
2711/**
2712 * nilfs_segctor_destroy - destroy the segment constructor.
2713 * @sci: nilfs_sc_info
2714 *
2715 * nilfs_segctor_destroy() kills the segctord thread and frees
2716 * the nilfs_sc_info struct.
2717 * Caller must hold the segment semaphore.
2718 */
2719static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2720{
2721 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2722 int flag;
2723
2724 up_write(&nilfs->ns_segctor_sem);
2725
2726 spin_lock(&sci->sc_state_lock);
2727 nilfs_segctor_kill_thread(sci);
2728 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2729 || sci->sc_seq_request != sci->sc_seq_done);
2730 spin_unlock(&sci->sc_state_lock);
2731
2732 if (flush_work(&sci->sc_iput_work))
2733 flag = true;
2734
2735 if (flag || !nilfs_segctor_confirm(sci))
2736 nilfs_segctor_write_out(sci);
2737
2738 if (!list_empty(&sci->sc_dirty_files)) {
2739 nilfs_msg(sci->sc_super, KERN_WARNING,
2740 "disposed unprocessed dirty file(s) when stopping log writer");
2741 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
2742 }
2743
2744 if (!list_empty(&sci->sc_iput_queue)) {
2745 nilfs_msg(sci->sc_super, KERN_WARNING,
2746 "disposed unprocessed inode(s) in iput queue when stopping log writer");
2747 nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 1);
2748 }
2749
2750 WARN_ON(!list_empty(&sci->sc_segbufs));
2751 WARN_ON(!list_empty(&sci->sc_write_logs));
2752
2753 nilfs_put_root(sci->sc_root);
2754
2755 down_write(&nilfs->ns_segctor_sem);
2756
2757 del_timer_sync(&sci->sc_timer);
2758 kfree(sci);
2759}
2760
2761/**
2762 * nilfs_attach_log_writer - attach log writer
2763 * @sb: super block instance
2764 * @root: root object of the current filesystem tree
2765 *
2766 * This allocates a log writer object, initializes it, and starts the
2767 * log writer.
2768 *
2769 * Return Value: On success, 0 is returned. On error, one of the following
2770 * negative error code is returned.
2771 *
2772 * %-ENOMEM - Insufficient memory available.
2773 */
2774int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
2775{
2776 struct the_nilfs *nilfs = sb->s_fs_info;
2777 int err;
2778
2779 if (nilfs->ns_writer) {
2780 /*
2781 * This happens if the filesystem was remounted
2782 * read/write after nilfs_error degenerated it into a
2783 * read-only mount.
2784 */
2785 nilfs_detach_log_writer(sb);
2786 }
2787
2788 nilfs->ns_writer = nilfs_segctor_new(sb, root);
2789 if (!nilfs->ns_writer)
2790 return -ENOMEM;
2791
2792 err = nilfs_segctor_start_thread(nilfs->ns_writer);
2793 if (err) {
2794 kfree(nilfs->ns_writer);
2795 nilfs->ns_writer = NULL;
2796 }
2797 return err;
2798}
2799
2800/**
2801 * nilfs_detach_log_writer - destroy log writer
2802 * @sb: super block instance
2803 *
2804 * This kills log writer daemon, frees the log writer object, and
2805 * destroys list of dirty files.
2806 */
2807void nilfs_detach_log_writer(struct super_block *sb)
2808{
2809 struct the_nilfs *nilfs = sb->s_fs_info;
2810 LIST_HEAD(garbage_list);
2811
2812 down_write(&nilfs->ns_segctor_sem);
2813 if (nilfs->ns_writer) {
2814 nilfs_segctor_destroy(nilfs->ns_writer);
2815 nilfs->ns_writer = NULL;
2816 }
2817
2818 /* Force to free the list of dirty files */
2819 spin_lock(&nilfs->ns_inode_lock);
2820 if (!list_empty(&nilfs->ns_dirty_files)) {
2821 list_splice_init(&nilfs->ns_dirty_files, &garbage_list);
2822 nilfs_msg(sb, KERN_WARNING,
2823 "disposed unprocessed dirty file(s) when detaching log writer");
2824 }
2825 spin_unlock(&nilfs->ns_inode_lock);
2826 up_write(&nilfs->ns_segctor_sem);
2827
2828 nilfs_dispose_list(nilfs, &garbage_list, 1);
2829}
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 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
21 *
22 */
23
24#include <linux/pagemap.h>
25#include <linux/buffer_head.h>
26#include <linux/writeback.h>
27#include <linux/bitops.h>
28#include <linux/bio.h>
29#include <linux/completion.h>
30#include <linux/blkdev.h>
31#include <linux/backing-dev.h>
32#include <linux/freezer.h>
33#include <linux/kthread.h>
34#include <linux/crc32.h>
35#include <linux/pagevec.h>
36#include <linux/slab.h>
37#include "nilfs.h"
38#include "btnode.h"
39#include "page.h"
40#include "segment.h"
41#include "sufile.h"
42#include "cpfile.h"
43#include "ifile.h"
44#include "segbuf.h"
45
46
47/*
48 * Segment constructor
49 */
50#define SC_N_INODEVEC 16 /* Size of locally allocated inode vector */
51
52#define SC_MAX_SEGDELTA 64 /* Upper limit of the number of segments
53 appended in collection retry loop */
54
55/* Construction mode */
56enum {
57 SC_LSEG_SR = 1, /* Make a logical segment having a super root */
58 SC_LSEG_DSYNC, /* Flush data blocks of a given file and make
59 a logical segment without a super root */
60 SC_FLUSH_FILE, /* Flush data files, leads to segment writes without
61 creating a checkpoint */
62 SC_FLUSH_DAT, /* Flush DAT file. This also creates segments without
63 a checkpoint */
64};
65
66/* Stage numbers of dirty block collection */
67enum {
68 NILFS_ST_INIT = 0,
69 NILFS_ST_GC, /* Collecting dirty blocks for GC */
70 NILFS_ST_FILE,
71 NILFS_ST_IFILE,
72 NILFS_ST_CPFILE,
73 NILFS_ST_SUFILE,
74 NILFS_ST_DAT,
75 NILFS_ST_SR, /* Super root */
76 NILFS_ST_DSYNC, /* Data sync blocks */
77 NILFS_ST_DONE,
78};
79
80#define CREATE_TRACE_POINTS
81#include <trace/events/nilfs2.h>
82
83/*
84 * nilfs_sc_cstage_inc(), nilfs_sc_cstage_set(), nilfs_sc_cstage_get() are
85 * wrapper functions of stage count (nilfs_sc_info->sc_stage.scnt). Users of
86 * the variable must use them because transition of stage count must involve
87 * trace events (trace_nilfs2_collection_stage_transition).
88 *
89 * nilfs_sc_cstage_get() isn't required for the above purpose because it doesn't
90 * produce tracepoint events. It is provided just for making the intention
91 * clear.
92 */
93static inline void nilfs_sc_cstage_inc(struct nilfs_sc_info *sci)
94{
95 sci->sc_stage.scnt++;
96 trace_nilfs2_collection_stage_transition(sci);
97}
98
99static inline void nilfs_sc_cstage_set(struct nilfs_sc_info *sci, int next_scnt)
100{
101 sci->sc_stage.scnt = next_scnt;
102 trace_nilfs2_collection_stage_transition(sci);
103}
104
105static inline int nilfs_sc_cstage_get(struct nilfs_sc_info *sci)
106{
107 return sci->sc_stage.scnt;
108}
109
110/* State flags of collection */
111#define NILFS_CF_NODE 0x0001 /* Collecting node blocks */
112#define NILFS_CF_IFILE_STARTED 0x0002 /* IFILE stage has started */
113#define NILFS_CF_SUFREED 0x0004 /* segment usages has been freed */
114#define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED)
115
116/* Operations depending on the construction mode and file type */
117struct nilfs_sc_operations {
118 int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *,
119 struct inode *);
120 int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *,
121 struct inode *);
122 int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *,
123 struct inode *);
124 void (*write_data_binfo)(struct nilfs_sc_info *,
125 struct nilfs_segsum_pointer *,
126 union nilfs_binfo *);
127 void (*write_node_binfo)(struct nilfs_sc_info *,
128 struct nilfs_segsum_pointer *,
129 union nilfs_binfo *);
130};
131
132/*
133 * Other definitions
134 */
135static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
136static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
137static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
138static void nilfs_dispose_list(struct the_nilfs *, struct list_head *, int);
139
140#define nilfs_cnt32_gt(a, b) \
141 (typecheck(__u32, a) && typecheck(__u32, b) && \
142 ((__s32)(b) - (__s32)(a) < 0))
143#define nilfs_cnt32_ge(a, b) \
144 (typecheck(__u32, a) && typecheck(__u32, b) && \
145 ((__s32)(a) - (__s32)(b) >= 0))
146#define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a)
147#define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a)
148
149static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
150{
151 struct nilfs_transaction_info *cur_ti = current->journal_info;
152 void *save = NULL;
153
154 if (cur_ti) {
155 if (cur_ti->ti_magic == NILFS_TI_MAGIC)
156 return ++cur_ti->ti_count;
157 else {
158 /*
159 * If journal_info field is occupied by other FS,
160 * it is saved and will be restored on
161 * nilfs_transaction_commit().
162 */
163 printk(KERN_WARNING
164 "NILFS warning: journal info from a different "
165 "FS\n");
166 save = current->journal_info;
167 }
168 }
169 if (!ti) {
170 ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
171 if (!ti)
172 return -ENOMEM;
173 ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
174 } else {
175 ti->ti_flags = 0;
176 }
177 ti->ti_count = 0;
178 ti->ti_save = save;
179 ti->ti_magic = NILFS_TI_MAGIC;
180 current->journal_info = ti;
181 return 0;
182}
183
184/**
185 * nilfs_transaction_begin - start indivisible file operations.
186 * @sb: super block
187 * @ti: nilfs_transaction_info
188 * @vacancy_check: flags for vacancy rate checks
189 *
190 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
191 * the segment semaphore, to make a segment construction and write tasks
192 * exclusive. The function is used with nilfs_transaction_commit() in pairs.
193 * The region enclosed by these two functions can be nested. To avoid a
194 * deadlock, the semaphore is only acquired or released in the outermost call.
195 *
196 * This function allocates a nilfs_transaction_info struct to keep context
197 * information on it. It is initialized and hooked onto the current task in
198 * the outermost call. If a pre-allocated struct is given to @ti, it is used
199 * instead; otherwise a new struct is assigned from a slab.
200 *
201 * When @vacancy_check flag is set, this function will check the amount of
202 * free space, and will wait for the GC to reclaim disk space if low capacity.
203 *
204 * Return Value: On success, 0 is returned. On error, one of the following
205 * negative error code is returned.
206 *
207 * %-ENOMEM - Insufficient memory available.
208 *
209 * %-ENOSPC - No space left on device
210 */
211int nilfs_transaction_begin(struct super_block *sb,
212 struct nilfs_transaction_info *ti,
213 int vacancy_check)
214{
215 struct the_nilfs *nilfs;
216 int ret = nilfs_prepare_segment_lock(ti);
217 struct nilfs_transaction_info *trace_ti;
218
219 if (unlikely(ret < 0))
220 return ret;
221 if (ret > 0) {
222 trace_ti = current->journal_info;
223
224 trace_nilfs2_transaction_transition(sb, trace_ti,
225 trace_ti->ti_count, trace_ti->ti_flags,
226 TRACE_NILFS2_TRANSACTION_BEGIN);
227 return 0;
228 }
229
230 sb_start_intwrite(sb);
231
232 nilfs = sb->s_fs_info;
233 down_read(&nilfs->ns_segctor_sem);
234 if (vacancy_check && nilfs_near_disk_full(nilfs)) {
235 up_read(&nilfs->ns_segctor_sem);
236 ret = -ENOSPC;
237 goto failed;
238 }
239
240 trace_ti = current->journal_info;
241 trace_nilfs2_transaction_transition(sb, trace_ti, trace_ti->ti_count,
242 trace_ti->ti_flags,
243 TRACE_NILFS2_TRANSACTION_BEGIN);
244 return 0;
245
246 failed:
247 ti = current->journal_info;
248 current->journal_info = ti->ti_save;
249 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
250 kmem_cache_free(nilfs_transaction_cachep, ti);
251 sb_end_intwrite(sb);
252 return ret;
253}
254
255/**
256 * nilfs_transaction_commit - commit indivisible file operations.
257 * @sb: super block
258 *
259 * nilfs_transaction_commit() releases the read semaphore which is
260 * acquired by nilfs_transaction_begin(). This is only performed
261 * in outermost call of this function. If a commit flag is set,
262 * nilfs_transaction_commit() sets a timer to start the segment
263 * constructor. If a sync flag is set, it starts construction
264 * directly.
265 */
266int nilfs_transaction_commit(struct super_block *sb)
267{
268 struct nilfs_transaction_info *ti = current->journal_info;
269 struct the_nilfs *nilfs = sb->s_fs_info;
270 int err = 0;
271
272 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
273 ti->ti_flags |= NILFS_TI_COMMIT;
274 if (ti->ti_count > 0) {
275 ti->ti_count--;
276 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
277 ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
278 return 0;
279 }
280 if (nilfs->ns_writer) {
281 struct nilfs_sc_info *sci = nilfs->ns_writer;
282
283 if (ti->ti_flags & NILFS_TI_COMMIT)
284 nilfs_segctor_start_timer(sci);
285 if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark)
286 nilfs_segctor_do_flush(sci, 0);
287 }
288 up_read(&nilfs->ns_segctor_sem);
289 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
290 ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
291
292 current->journal_info = ti->ti_save;
293
294 if (ti->ti_flags & NILFS_TI_SYNC)
295 err = nilfs_construct_segment(sb);
296 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
297 kmem_cache_free(nilfs_transaction_cachep, ti);
298 sb_end_intwrite(sb);
299 return err;
300}
301
302void nilfs_transaction_abort(struct super_block *sb)
303{
304 struct nilfs_transaction_info *ti = current->journal_info;
305 struct the_nilfs *nilfs = sb->s_fs_info;
306
307 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
308 if (ti->ti_count > 0) {
309 ti->ti_count--;
310 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
311 ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
312 return;
313 }
314 up_read(&nilfs->ns_segctor_sem);
315
316 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
317 ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
318
319 current->journal_info = ti->ti_save;
320 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
321 kmem_cache_free(nilfs_transaction_cachep, ti);
322 sb_end_intwrite(sb);
323}
324
325void nilfs_relax_pressure_in_lock(struct super_block *sb)
326{
327 struct the_nilfs *nilfs = sb->s_fs_info;
328 struct nilfs_sc_info *sci = nilfs->ns_writer;
329
330 if (!sci || !sci->sc_flush_request)
331 return;
332
333 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
334 up_read(&nilfs->ns_segctor_sem);
335
336 down_write(&nilfs->ns_segctor_sem);
337 if (sci->sc_flush_request &&
338 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
339 struct nilfs_transaction_info *ti = current->journal_info;
340
341 ti->ti_flags |= NILFS_TI_WRITER;
342 nilfs_segctor_do_immediate_flush(sci);
343 ti->ti_flags &= ~NILFS_TI_WRITER;
344 }
345 downgrade_write(&nilfs->ns_segctor_sem);
346}
347
348static void nilfs_transaction_lock(struct super_block *sb,
349 struct nilfs_transaction_info *ti,
350 int gcflag)
351{
352 struct nilfs_transaction_info *cur_ti = current->journal_info;
353 struct the_nilfs *nilfs = sb->s_fs_info;
354 struct nilfs_sc_info *sci = nilfs->ns_writer;
355
356 WARN_ON(cur_ti);
357 ti->ti_flags = NILFS_TI_WRITER;
358 ti->ti_count = 0;
359 ti->ti_save = cur_ti;
360 ti->ti_magic = NILFS_TI_MAGIC;
361 current->journal_info = ti;
362
363 for (;;) {
364 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
365 ti->ti_flags, TRACE_NILFS2_TRANSACTION_TRYLOCK);
366
367 down_write(&nilfs->ns_segctor_sem);
368 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags))
369 break;
370
371 nilfs_segctor_do_immediate_flush(sci);
372
373 up_write(&nilfs->ns_segctor_sem);
374 yield();
375 }
376 if (gcflag)
377 ti->ti_flags |= NILFS_TI_GC;
378
379 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
380 ti->ti_flags, TRACE_NILFS2_TRANSACTION_LOCK);
381}
382
383static void nilfs_transaction_unlock(struct super_block *sb)
384{
385 struct nilfs_transaction_info *ti = current->journal_info;
386 struct the_nilfs *nilfs = sb->s_fs_info;
387
388 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
389 BUG_ON(ti->ti_count > 0);
390
391 up_write(&nilfs->ns_segctor_sem);
392 current->journal_info = ti->ti_save;
393
394 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
395 ti->ti_flags, TRACE_NILFS2_TRANSACTION_UNLOCK);
396}
397
398static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
399 struct nilfs_segsum_pointer *ssp,
400 unsigned bytes)
401{
402 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
403 unsigned blocksize = sci->sc_super->s_blocksize;
404 void *p;
405
406 if (unlikely(ssp->offset + bytes > blocksize)) {
407 ssp->offset = 0;
408 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
409 &segbuf->sb_segsum_buffers));
410 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
411 }
412 p = ssp->bh->b_data + ssp->offset;
413 ssp->offset += bytes;
414 return p;
415}
416
417/**
418 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
419 * @sci: nilfs_sc_info
420 */
421static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
422{
423 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
424 struct buffer_head *sumbh;
425 unsigned sumbytes;
426 unsigned flags = 0;
427 int err;
428
429 if (nilfs_doing_gc())
430 flags = NILFS_SS_GC;
431 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno);
432 if (unlikely(err))
433 return err;
434
435 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
436 sumbytes = segbuf->sb_sum.sumbytes;
437 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
438 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
439 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
440 return 0;
441}
442
443static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
444{
445 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
446 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
447 return -E2BIG; /* The current segment is filled up
448 (internal code) */
449 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
450 return nilfs_segctor_reset_segment_buffer(sci);
451}
452
453static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
454{
455 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
456 int err;
457
458 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
459 err = nilfs_segctor_feed_segment(sci);
460 if (err)
461 return err;
462 segbuf = sci->sc_curseg;
463 }
464 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root);
465 if (likely(!err))
466 segbuf->sb_sum.flags |= NILFS_SS_SR;
467 return err;
468}
469
470/*
471 * Functions for making segment summary and payloads
472 */
473static int nilfs_segctor_segsum_block_required(
474 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
475 unsigned binfo_size)
476{
477 unsigned blocksize = sci->sc_super->s_blocksize;
478 /* Size of finfo and binfo is enough small against blocksize */
479
480 return ssp->offset + binfo_size +
481 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
482 blocksize;
483}
484
485static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
486 struct inode *inode)
487{
488 sci->sc_curseg->sb_sum.nfinfo++;
489 sci->sc_binfo_ptr = sci->sc_finfo_ptr;
490 nilfs_segctor_map_segsum_entry(
491 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
492
493 if (NILFS_I(inode)->i_root &&
494 !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
495 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
496 /* skip finfo */
497}
498
499static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
500 struct inode *inode)
501{
502 struct nilfs_finfo *finfo;
503 struct nilfs_inode_info *ii;
504 struct nilfs_segment_buffer *segbuf;
505 __u64 cno;
506
507 if (sci->sc_blk_cnt == 0)
508 return;
509
510 ii = NILFS_I(inode);
511
512 if (test_bit(NILFS_I_GCINODE, &ii->i_state))
513 cno = ii->i_cno;
514 else if (NILFS_ROOT_METADATA_FILE(inode->i_ino))
515 cno = 0;
516 else
517 cno = sci->sc_cno;
518
519 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
520 sizeof(*finfo));
521 finfo->fi_ino = cpu_to_le64(inode->i_ino);
522 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
523 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
524 finfo->fi_cno = cpu_to_le64(cno);
525
526 segbuf = sci->sc_curseg;
527 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
528 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
529 sci->sc_finfo_ptr = sci->sc_binfo_ptr;
530 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
531}
532
533static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
534 struct buffer_head *bh,
535 struct inode *inode,
536 unsigned binfo_size)
537{
538 struct nilfs_segment_buffer *segbuf;
539 int required, err = 0;
540
541 retry:
542 segbuf = sci->sc_curseg;
543 required = nilfs_segctor_segsum_block_required(
544 sci, &sci->sc_binfo_ptr, binfo_size);
545 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
546 nilfs_segctor_end_finfo(sci, inode);
547 err = nilfs_segctor_feed_segment(sci);
548 if (err)
549 return err;
550 goto retry;
551 }
552 if (unlikely(required)) {
553 err = nilfs_segbuf_extend_segsum(segbuf);
554 if (unlikely(err))
555 goto failed;
556 }
557 if (sci->sc_blk_cnt == 0)
558 nilfs_segctor_begin_finfo(sci, inode);
559
560 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
561 /* Substitution to vblocknr is delayed until update_blocknr() */
562 nilfs_segbuf_add_file_buffer(segbuf, bh);
563 sci->sc_blk_cnt++;
564 failed:
565 return err;
566}
567
568/*
569 * Callback functions that enumerate, mark, and collect dirty blocks
570 */
571static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
572 struct buffer_head *bh, struct inode *inode)
573{
574 int err;
575
576 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
577 if (err < 0)
578 return err;
579
580 err = nilfs_segctor_add_file_block(sci, bh, inode,
581 sizeof(struct nilfs_binfo_v));
582 if (!err)
583 sci->sc_datablk_cnt++;
584 return err;
585}
586
587static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
588 struct buffer_head *bh,
589 struct inode *inode)
590{
591 return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
592}
593
594static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
595 struct buffer_head *bh,
596 struct inode *inode)
597{
598 WARN_ON(!buffer_dirty(bh));
599 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
600}
601
602static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
603 struct nilfs_segsum_pointer *ssp,
604 union nilfs_binfo *binfo)
605{
606 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
607 sci, ssp, sizeof(*binfo_v));
608 *binfo_v = binfo->bi_v;
609}
610
611static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
612 struct nilfs_segsum_pointer *ssp,
613 union nilfs_binfo *binfo)
614{
615 __le64 *vblocknr = nilfs_segctor_map_segsum_entry(
616 sci, ssp, sizeof(*vblocknr));
617 *vblocknr = binfo->bi_v.bi_vblocknr;
618}
619
620static struct nilfs_sc_operations nilfs_sc_file_ops = {
621 .collect_data = nilfs_collect_file_data,
622 .collect_node = nilfs_collect_file_node,
623 .collect_bmap = nilfs_collect_file_bmap,
624 .write_data_binfo = nilfs_write_file_data_binfo,
625 .write_node_binfo = nilfs_write_file_node_binfo,
626};
627
628static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
629 struct buffer_head *bh, struct inode *inode)
630{
631 int err;
632
633 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
634 if (err < 0)
635 return err;
636
637 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
638 if (!err)
639 sci->sc_datablk_cnt++;
640 return err;
641}
642
643static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
644 struct buffer_head *bh, struct inode *inode)
645{
646 WARN_ON(!buffer_dirty(bh));
647 return nilfs_segctor_add_file_block(sci, bh, inode,
648 sizeof(struct nilfs_binfo_dat));
649}
650
651static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
652 struct nilfs_segsum_pointer *ssp,
653 union nilfs_binfo *binfo)
654{
655 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
656 sizeof(*blkoff));
657 *blkoff = binfo->bi_dat.bi_blkoff;
658}
659
660static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
661 struct nilfs_segsum_pointer *ssp,
662 union nilfs_binfo *binfo)
663{
664 struct nilfs_binfo_dat *binfo_dat =
665 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
666 *binfo_dat = binfo->bi_dat;
667}
668
669static struct nilfs_sc_operations nilfs_sc_dat_ops = {
670 .collect_data = nilfs_collect_dat_data,
671 .collect_node = nilfs_collect_file_node,
672 .collect_bmap = nilfs_collect_dat_bmap,
673 .write_data_binfo = nilfs_write_dat_data_binfo,
674 .write_node_binfo = nilfs_write_dat_node_binfo,
675};
676
677static struct nilfs_sc_operations nilfs_sc_dsync_ops = {
678 .collect_data = nilfs_collect_file_data,
679 .collect_node = NULL,
680 .collect_bmap = NULL,
681 .write_data_binfo = nilfs_write_file_data_binfo,
682 .write_node_binfo = NULL,
683};
684
685static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
686 struct list_head *listp,
687 size_t nlimit,
688 loff_t start, loff_t end)
689{
690 struct address_space *mapping = inode->i_mapping;
691 struct pagevec pvec;
692 pgoff_t index = 0, last = ULONG_MAX;
693 size_t ndirties = 0;
694 int i;
695
696 if (unlikely(start != 0 || end != LLONG_MAX)) {
697 /*
698 * A valid range is given for sync-ing data pages. The
699 * range is rounded to per-page; extra dirty buffers
700 * may be included if blocksize < pagesize.
701 */
702 index = start >> PAGE_SHIFT;
703 last = end >> PAGE_SHIFT;
704 }
705 pagevec_init(&pvec, 0);
706 repeat:
707 if (unlikely(index > last) ||
708 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
709 min_t(pgoff_t, last - index,
710 PAGEVEC_SIZE - 1) + 1))
711 return ndirties;
712
713 for (i = 0; i < pagevec_count(&pvec); i++) {
714 struct buffer_head *bh, *head;
715 struct page *page = pvec.pages[i];
716
717 if (unlikely(page->index > last))
718 break;
719
720 lock_page(page);
721 if (!page_has_buffers(page))
722 create_empty_buffers(page, 1 << inode->i_blkbits, 0);
723 unlock_page(page);
724
725 bh = head = page_buffers(page);
726 do {
727 if (!buffer_dirty(bh) || buffer_async_write(bh))
728 continue;
729 get_bh(bh);
730 list_add_tail(&bh->b_assoc_buffers, listp);
731 ndirties++;
732 if (unlikely(ndirties >= nlimit)) {
733 pagevec_release(&pvec);
734 cond_resched();
735 return ndirties;
736 }
737 } while (bh = bh->b_this_page, bh != head);
738 }
739 pagevec_release(&pvec);
740 cond_resched();
741 goto repeat;
742}
743
744static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
745 struct list_head *listp)
746{
747 struct nilfs_inode_info *ii = NILFS_I(inode);
748 struct address_space *mapping = &ii->i_btnode_cache;
749 struct pagevec pvec;
750 struct buffer_head *bh, *head;
751 unsigned int i;
752 pgoff_t index = 0;
753
754 pagevec_init(&pvec, 0);
755
756 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
757 PAGEVEC_SIZE)) {
758 for (i = 0; i < pagevec_count(&pvec); i++) {
759 bh = head = page_buffers(pvec.pages[i]);
760 do {
761 if (buffer_dirty(bh) &&
762 !buffer_async_write(bh)) {
763 get_bh(bh);
764 list_add_tail(&bh->b_assoc_buffers,
765 listp);
766 }
767 bh = bh->b_this_page;
768 } while (bh != head);
769 }
770 pagevec_release(&pvec);
771 cond_resched();
772 }
773}
774
775static void nilfs_dispose_list(struct the_nilfs *nilfs,
776 struct list_head *head, int force)
777{
778 struct nilfs_inode_info *ii, *n;
779 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
780 unsigned nv = 0;
781
782 while (!list_empty(head)) {
783 spin_lock(&nilfs->ns_inode_lock);
784 list_for_each_entry_safe(ii, n, head, i_dirty) {
785 list_del_init(&ii->i_dirty);
786 if (force) {
787 if (unlikely(ii->i_bh)) {
788 brelse(ii->i_bh);
789 ii->i_bh = NULL;
790 }
791 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
792 set_bit(NILFS_I_QUEUED, &ii->i_state);
793 list_add_tail(&ii->i_dirty,
794 &nilfs->ns_dirty_files);
795 continue;
796 }
797 ivec[nv++] = ii;
798 if (nv == SC_N_INODEVEC)
799 break;
800 }
801 spin_unlock(&nilfs->ns_inode_lock);
802
803 for (pii = ivec; nv > 0; pii++, nv--)
804 iput(&(*pii)->vfs_inode);
805 }
806}
807
808static void nilfs_iput_work_func(struct work_struct *work)
809{
810 struct nilfs_sc_info *sci = container_of(work, struct nilfs_sc_info,
811 sc_iput_work);
812 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
813
814 nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 0);
815}
816
817static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
818 struct nilfs_root *root)
819{
820 int ret = 0;
821
822 if (nilfs_mdt_fetch_dirty(root->ifile))
823 ret++;
824 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
825 ret++;
826 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
827 ret++;
828 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat))
829 ret++;
830 return ret;
831}
832
833static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
834{
835 return list_empty(&sci->sc_dirty_files) &&
836 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
837 sci->sc_nfreesegs == 0 &&
838 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
839}
840
841static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
842{
843 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
844 int ret = 0;
845
846 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
847 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
848
849 spin_lock(&nilfs->ns_inode_lock);
850 if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci))
851 ret++;
852
853 spin_unlock(&nilfs->ns_inode_lock);
854 return ret;
855}
856
857static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
858{
859 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
860
861 nilfs_mdt_clear_dirty(sci->sc_root->ifile);
862 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
863 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
864 nilfs_mdt_clear_dirty(nilfs->ns_dat);
865}
866
867static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
868{
869 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
870 struct buffer_head *bh_cp;
871 struct nilfs_checkpoint *raw_cp;
872 int err;
873
874 /* XXX: this interface will be changed */
875 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
876 &raw_cp, &bh_cp);
877 if (likely(!err)) {
878 /* The following code is duplicated with cpfile. But, it is
879 needed to collect the checkpoint even if it was not newly
880 created */
881 mark_buffer_dirty(bh_cp);
882 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
883 nilfs_cpfile_put_checkpoint(
884 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
885 } else
886 WARN_ON(err == -EINVAL || err == -ENOENT);
887
888 return err;
889}
890
891static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
892{
893 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
894 struct buffer_head *bh_cp;
895 struct nilfs_checkpoint *raw_cp;
896 int err;
897
898 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
899 &raw_cp, &bh_cp);
900 if (unlikely(err)) {
901 WARN_ON(err == -EINVAL || err == -ENOENT);
902 goto failed_ibh;
903 }
904 raw_cp->cp_snapshot_list.ssl_next = 0;
905 raw_cp->cp_snapshot_list.ssl_prev = 0;
906 raw_cp->cp_inodes_count =
907 cpu_to_le64(atomic64_read(&sci->sc_root->inodes_count));
908 raw_cp->cp_blocks_count =
909 cpu_to_le64(atomic64_read(&sci->sc_root->blocks_count));
910 raw_cp->cp_nblk_inc =
911 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
912 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
913 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
914
915 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
916 nilfs_checkpoint_clear_minor(raw_cp);
917 else
918 nilfs_checkpoint_set_minor(raw_cp);
919
920 nilfs_write_inode_common(sci->sc_root->ifile,
921 &raw_cp->cp_ifile_inode, 1);
922 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
923 return 0;
924
925 failed_ibh:
926 return err;
927}
928
929static void nilfs_fill_in_file_bmap(struct inode *ifile,
930 struct nilfs_inode_info *ii)
931
932{
933 struct buffer_head *ibh;
934 struct nilfs_inode *raw_inode;
935
936 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
937 ibh = ii->i_bh;
938 BUG_ON(!ibh);
939 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
940 ibh);
941 nilfs_bmap_write(ii->i_bmap, raw_inode);
942 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
943 }
944}
945
946static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
947{
948 struct nilfs_inode_info *ii;
949
950 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
951 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
952 set_bit(NILFS_I_COLLECTED, &ii->i_state);
953 }
954}
955
956static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
957 struct the_nilfs *nilfs)
958{
959 struct buffer_head *bh_sr;
960 struct nilfs_super_root *raw_sr;
961 unsigned isz, srsz;
962
963 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
964 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
965 isz = nilfs->ns_inode_size;
966 srsz = NILFS_SR_BYTES(isz);
967
968 raw_sr->sr_bytes = cpu_to_le16(srsz);
969 raw_sr->sr_nongc_ctime
970 = cpu_to_le64(nilfs_doing_gc() ?
971 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
972 raw_sr->sr_flags = 0;
973
974 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr +
975 NILFS_SR_DAT_OFFSET(isz), 1);
976 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
977 NILFS_SR_CPFILE_OFFSET(isz), 1);
978 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
979 NILFS_SR_SUFILE_OFFSET(isz), 1);
980 memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz);
981}
982
983static void nilfs_redirty_inodes(struct list_head *head)
984{
985 struct nilfs_inode_info *ii;
986
987 list_for_each_entry(ii, head, i_dirty) {
988 if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
989 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
990 }
991}
992
993static void nilfs_drop_collected_inodes(struct list_head *head)
994{
995 struct nilfs_inode_info *ii;
996
997 list_for_each_entry(ii, head, i_dirty) {
998 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
999 continue;
1000
1001 clear_bit(NILFS_I_INODE_SYNC, &ii->i_state);
1002 set_bit(NILFS_I_UPDATED, &ii->i_state);
1003 }
1004}
1005
1006static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
1007 struct inode *inode,
1008 struct list_head *listp,
1009 int (*collect)(struct nilfs_sc_info *,
1010 struct buffer_head *,
1011 struct inode *))
1012{
1013 struct buffer_head *bh, *n;
1014 int err = 0;
1015
1016 if (collect) {
1017 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
1018 list_del_init(&bh->b_assoc_buffers);
1019 err = collect(sci, bh, inode);
1020 brelse(bh);
1021 if (unlikely(err))
1022 goto dispose_buffers;
1023 }
1024 return 0;
1025 }
1026
1027 dispose_buffers:
1028 while (!list_empty(listp)) {
1029 bh = list_first_entry(listp, struct buffer_head,
1030 b_assoc_buffers);
1031 list_del_init(&bh->b_assoc_buffers);
1032 brelse(bh);
1033 }
1034 return err;
1035}
1036
1037static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
1038{
1039 /* Remaining number of blocks within segment buffer */
1040 return sci->sc_segbuf_nblocks -
1041 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
1042}
1043
1044static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
1045 struct inode *inode,
1046 struct nilfs_sc_operations *sc_ops)
1047{
1048 LIST_HEAD(data_buffers);
1049 LIST_HEAD(node_buffers);
1050 int err;
1051
1052 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1053 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1054
1055 n = nilfs_lookup_dirty_data_buffers(
1056 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
1057 if (n > rest) {
1058 err = nilfs_segctor_apply_buffers(
1059 sci, inode, &data_buffers,
1060 sc_ops->collect_data);
1061 BUG_ON(!err); /* always receive -E2BIG or true error */
1062 goto break_or_fail;
1063 }
1064 }
1065 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
1066
1067 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1068 err = nilfs_segctor_apply_buffers(
1069 sci, inode, &data_buffers, sc_ops->collect_data);
1070 if (unlikely(err)) {
1071 /* dispose node list */
1072 nilfs_segctor_apply_buffers(
1073 sci, inode, &node_buffers, NULL);
1074 goto break_or_fail;
1075 }
1076 sci->sc_stage.flags |= NILFS_CF_NODE;
1077 }
1078 /* Collect node */
1079 err = nilfs_segctor_apply_buffers(
1080 sci, inode, &node_buffers, sc_ops->collect_node);
1081 if (unlikely(err))
1082 goto break_or_fail;
1083
1084 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1085 err = nilfs_segctor_apply_buffers(
1086 sci, inode, &node_buffers, sc_ops->collect_bmap);
1087 if (unlikely(err))
1088 goto break_or_fail;
1089
1090 nilfs_segctor_end_finfo(sci, inode);
1091 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1092
1093 break_or_fail:
1094 return err;
1095}
1096
1097static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1098 struct inode *inode)
1099{
1100 LIST_HEAD(data_buffers);
1101 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1102 int err;
1103
1104 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1105 sci->sc_dsync_start,
1106 sci->sc_dsync_end);
1107
1108 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1109 nilfs_collect_file_data);
1110 if (!err) {
1111 nilfs_segctor_end_finfo(sci, inode);
1112 BUG_ON(n > rest);
1113 /* always receive -E2BIG or true error if n > rest */
1114 }
1115 return err;
1116}
1117
1118static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1119{
1120 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1121 struct list_head *head;
1122 struct nilfs_inode_info *ii;
1123 size_t ndone;
1124 int err = 0;
1125
1126 switch (nilfs_sc_cstage_get(sci)) {
1127 case NILFS_ST_INIT:
1128 /* Pre-processes */
1129 sci->sc_stage.flags = 0;
1130
1131 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1132 sci->sc_nblk_inc = 0;
1133 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1134 if (mode == SC_LSEG_DSYNC) {
1135 nilfs_sc_cstage_set(sci, NILFS_ST_DSYNC);
1136 goto dsync_mode;
1137 }
1138 }
1139
1140 sci->sc_stage.dirty_file_ptr = NULL;
1141 sci->sc_stage.gc_inode_ptr = NULL;
1142 if (mode == SC_FLUSH_DAT) {
1143 nilfs_sc_cstage_set(sci, NILFS_ST_DAT);
1144 goto dat_stage;
1145 }
1146 nilfs_sc_cstage_inc(sci); /* Fall through */
1147 case NILFS_ST_GC:
1148 if (nilfs_doing_gc()) {
1149 head = &sci->sc_gc_inodes;
1150 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1151 head, i_dirty);
1152 list_for_each_entry_continue(ii, head, i_dirty) {
1153 err = nilfs_segctor_scan_file(
1154 sci, &ii->vfs_inode,
1155 &nilfs_sc_file_ops);
1156 if (unlikely(err)) {
1157 sci->sc_stage.gc_inode_ptr = list_entry(
1158 ii->i_dirty.prev,
1159 struct nilfs_inode_info,
1160 i_dirty);
1161 goto break_or_fail;
1162 }
1163 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1164 }
1165 sci->sc_stage.gc_inode_ptr = NULL;
1166 }
1167 nilfs_sc_cstage_inc(sci); /* Fall through */
1168 case NILFS_ST_FILE:
1169 head = &sci->sc_dirty_files;
1170 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1171 i_dirty);
1172 list_for_each_entry_continue(ii, head, i_dirty) {
1173 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1174
1175 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1176 &nilfs_sc_file_ops);
1177 if (unlikely(err)) {
1178 sci->sc_stage.dirty_file_ptr =
1179 list_entry(ii->i_dirty.prev,
1180 struct nilfs_inode_info,
1181 i_dirty);
1182 goto break_or_fail;
1183 }
1184 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1185 /* XXX: required ? */
1186 }
1187 sci->sc_stage.dirty_file_ptr = NULL;
1188 if (mode == SC_FLUSH_FILE) {
1189 nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1190 return 0;
1191 }
1192 nilfs_sc_cstage_inc(sci);
1193 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1194 /* Fall through */
1195 case NILFS_ST_IFILE:
1196 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile,
1197 &nilfs_sc_file_ops);
1198 if (unlikely(err))
1199 break;
1200 nilfs_sc_cstage_inc(sci);
1201 /* Creating a checkpoint */
1202 err = nilfs_segctor_create_checkpoint(sci);
1203 if (unlikely(err))
1204 break;
1205 /* Fall through */
1206 case NILFS_ST_CPFILE:
1207 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1208 &nilfs_sc_file_ops);
1209 if (unlikely(err))
1210 break;
1211 nilfs_sc_cstage_inc(sci); /* Fall through */
1212 case NILFS_ST_SUFILE:
1213 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1214 sci->sc_nfreesegs, &ndone);
1215 if (unlikely(err)) {
1216 nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1217 sci->sc_freesegs, ndone,
1218 NULL);
1219 break;
1220 }
1221 sci->sc_stage.flags |= NILFS_CF_SUFREED;
1222
1223 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1224 &nilfs_sc_file_ops);
1225 if (unlikely(err))
1226 break;
1227 nilfs_sc_cstage_inc(sci); /* Fall through */
1228 case NILFS_ST_DAT:
1229 dat_stage:
1230 err = nilfs_segctor_scan_file(sci, nilfs->ns_dat,
1231 &nilfs_sc_dat_ops);
1232 if (unlikely(err))
1233 break;
1234 if (mode == SC_FLUSH_DAT) {
1235 nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1236 return 0;
1237 }
1238 nilfs_sc_cstage_inc(sci); /* Fall through */
1239 case NILFS_ST_SR:
1240 if (mode == SC_LSEG_SR) {
1241 /* Appending a super root */
1242 err = nilfs_segctor_add_super_root(sci);
1243 if (unlikely(err))
1244 break;
1245 }
1246 /* End of a logical segment */
1247 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1248 nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1249 return 0;
1250 case NILFS_ST_DSYNC:
1251 dsync_mode:
1252 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1253 ii = sci->sc_dsync_inode;
1254 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1255 break;
1256
1257 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1258 if (unlikely(err))
1259 break;
1260 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1261 nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1262 return 0;
1263 case NILFS_ST_DONE:
1264 return 0;
1265 default:
1266 BUG();
1267 }
1268
1269 break_or_fail:
1270 return err;
1271}
1272
1273/**
1274 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1275 * @sci: nilfs_sc_info
1276 * @nilfs: nilfs object
1277 */
1278static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1279 struct the_nilfs *nilfs)
1280{
1281 struct nilfs_segment_buffer *segbuf, *prev;
1282 __u64 nextnum;
1283 int err, alloc = 0;
1284
1285 segbuf = nilfs_segbuf_new(sci->sc_super);
1286 if (unlikely(!segbuf))
1287 return -ENOMEM;
1288
1289 if (list_empty(&sci->sc_write_logs)) {
1290 nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1291 nilfs->ns_pseg_offset, nilfs);
1292 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1293 nilfs_shift_to_next_segment(nilfs);
1294 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1295 }
1296
1297 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1298 nextnum = nilfs->ns_nextnum;
1299
1300 if (nilfs->ns_segnum == nilfs->ns_nextnum)
1301 /* Start from the head of a new full segment */
1302 alloc++;
1303 } else {
1304 /* Continue logs */
1305 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1306 nilfs_segbuf_map_cont(segbuf, prev);
1307 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1308 nextnum = prev->sb_nextnum;
1309
1310 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1311 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1312 segbuf->sb_sum.seg_seq++;
1313 alloc++;
1314 }
1315 }
1316
1317 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1318 if (err)
1319 goto failed;
1320
1321 if (alloc) {
1322 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1323 if (err)
1324 goto failed;
1325 }
1326 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1327
1328 BUG_ON(!list_empty(&sci->sc_segbufs));
1329 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1330 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1331 return 0;
1332
1333 failed:
1334 nilfs_segbuf_free(segbuf);
1335 return err;
1336}
1337
1338static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1339 struct the_nilfs *nilfs, int nadd)
1340{
1341 struct nilfs_segment_buffer *segbuf, *prev;
1342 struct inode *sufile = nilfs->ns_sufile;
1343 __u64 nextnextnum;
1344 LIST_HEAD(list);
1345 int err, ret, i;
1346
1347 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1348 /*
1349 * Since the segment specified with nextnum might be allocated during
1350 * the previous construction, the buffer including its segusage may
1351 * not be dirty. The following call ensures that the buffer is dirty
1352 * and will pin the buffer on memory until the sufile is written.
1353 */
1354 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1355 if (unlikely(err))
1356 return err;
1357
1358 for (i = 0; i < nadd; i++) {
1359 /* extend segment info */
1360 err = -ENOMEM;
1361 segbuf = nilfs_segbuf_new(sci->sc_super);
1362 if (unlikely(!segbuf))
1363 goto failed;
1364
1365 /* map this buffer to region of segment on-disk */
1366 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1367 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1368
1369 /* allocate the next next full segment */
1370 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1371 if (unlikely(err))
1372 goto failed_segbuf;
1373
1374 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1375 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1376
1377 list_add_tail(&segbuf->sb_list, &list);
1378 prev = segbuf;
1379 }
1380 list_splice_tail(&list, &sci->sc_segbufs);
1381 return 0;
1382
1383 failed_segbuf:
1384 nilfs_segbuf_free(segbuf);
1385 failed:
1386 list_for_each_entry(segbuf, &list, sb_list) {
1387 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1388 WARN_ON(ret); /* never fails */
1389 }
1390 nilfs_destroy_logs(&list);
1391 return err;
1392}
1393
1394static void nilfs_free_incomplete_logs(struct list_head *logs,
1395 struct the_nilfs *nilfs)
1396{
1397 struct nilfs_segment_buffer *segbuf, *prev;
1398 struct inode *sufile = nilfs->ns_sufile;
1399 int ret;
1400
1401 segbuf = NILFS_FIRST_SEGBUF(logs);
1402 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1403 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1404 WARN_ON(ret); /* never fails */
1405 }
1406 if (atomic_read(&segbuf->sb_err)) {
1407 /* Case 1: The first segment failed */
1408 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1409 /* Case 1a: Partial segment appended into an existing
1410 segment */
1411 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1412 segbuf->sb_fseg_end);
1413 else /* Case 1b: New full segment */
1414 set_nilfs_discontinued(nilfs);
1415 }
1416
1417 prev = segbuf;
1418 list_for_each_entry_continue(segbuf, logs, sb_list) {
1419 if (prev->sb_nextnum != segbuf->sb_nextnum) {
1420 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1421 WARN_ON(ret); /* never fails */
1422 }
1423 if (atomic_read(&segbuf->sb_err) &&
1424 segbuf->sb_segnum != nilfs->ns_nextnum)
1425 /* Case 2: extended segment (!= next) failed */
1426 nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1427 prev = segbuf;
1428 }
1429}
1430
1431static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1432 struct inode *sufile)
1433{
1434 struct nilfs_segment_buffer *segbuf;
1435 unsigned long live_blocks;
1436 int ret;
1437
1438 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1439 live_blocks = segbuf->sb_sum.nblocks +
1440 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1441 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1442 live_blocks,
1443 sci->sc_seg_ctime);
1444 WARN_ON(ret); /* always succeed because the segusage is dirty */
1445 }
1446}
1447
1448static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1449{
1450 struct nilfs_segment_buffer *segbuf;
1451 int ret;
1452
1453 segbuf = NILFS_FIRST_SEGBUF(logs);
1454 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1455 segbuf->sb_pseg_start -
1456 segbuf->sb_fseg_start, 0);
1457 WARN_ON(ret); /* always succeed because the segusage is dirty */
1458
1459 list_for_each_entry_continue(segbuf, logs, sb_list) {
1460 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1461 0, 0);
1462 WARN_ON(ret); /* always succeed */
1463 }
1464}
1465
1466static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1467 struct nilfs_segment_buffer *last,
1468 struct inode *sufile)
1469{
1470 struct nilfs_segment_buffer *segbuf = last;
1471 int ret;
1472
1473 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1474 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1475 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1476 WARN_ON(ret);
1477 }
1478 nilfs_truncate_logs(&sci->sc_segbufs, last);
1479}
1480
1481
1482static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1483 struct the_nilfs *nilfs, int mode)
1484{
1485 struct nilfs_cstage prev_stage = sci->sc_stage;
1486 int err, nadd = 1;
1487
1488 /* Collection retry loop */
1489 for (;;) {
1490 sci->sc_nblk_this_inc = 0;
1491 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1492
1493 err = nilfs_segctor_reset_segment_buffer(sci);
1494 if (unlikely(err))
1495 goto failed;
1496
1497 err = nilfs_segctor_collect_blocks(sci, mode);
1498 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1499 if (!err)
1500 break;
1501
1502 if (unlikely(err != -E2BIG))
1503 goto failed;
1504
1505 /* The current segment is filled up */
1506 if (mode != SC_LSEG_SR ||
1507 nilfs_sc_cstage_get(sci) < NILFS_ST_CPFILE)
1508 break;
1509
1510 nilfs_clear_logs(&sci->sc_segbufs);
1511
1512 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1513 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1514 sci->sc_freesegs,
1515 sci->sc_nfreesegs,
1516 NULL);
1517 WARN_ON(err); /* do not happen */
1518 sci->sc_stage.flags &= ~NILFS_CF_SUFREED;
1519 }
1520
1521 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1522 if (unlikely(err))
1523 return err;
1524
1525 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1526 sci->sc_stage = prev_stage;
1527 }
1528 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1529 return 0;
1530
1531 failed:
1532 return err;
1533}
1534
1535static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1536 struct buffer_head *new_bh)
1537{
1538 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1539
1540 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1541 /* The caller must release old_bh */
1542}
1543
1544static int
1545nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1546 struct nilfs_segment_buffer *segbuf,
1547 int mode)
1548{
1549 struct inode *inode = NULL;
1550 sector_t blocknr;
1551 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1552 unsigned long nblocks = 0, ndatablk = 0;
1553 struct nilfs_sc_operations *sc_op = NULL;
1554 struct nilfs_segsum_pointer ssp;
1555 struct nilfs_finfo *finfo = NULL;
1556 union nilfs_binfo binfo;
1557 struct buffer_head *bh, *bh_org;
1558 ino_t ino = 0;
1559 int err = 0;
1560
1561 if (!nfinfo)
1562 goto out;
1563
1564 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1565 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1566 ssp.offset = sizeof(struct nilfs_segment_summary);
1567
1568 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1569 if (bh == segbuf->sb_super_root)
1570 break;
1571 if (!finfo) {
1572 finfo = nilfs_segctor_map_segsum_entry(
1573 sci, &ssp, sizeof(*finfo));
1574 ino = le64_to_cpu(finfo->fi_ino);
1575 nblocks = le32_to_cpu(finfo->fi_nblocks);
1576 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1577
1578 inode = bh->b_page->mapping->host;
1579
1580 if (mode == SC_LSEG_DSYNC)
1581 sc_op = &nilfs_sc_dsync_ops;
1582 else if (ino == NILFS_DAT_INO)
1583 sc_op = &nilfs_sc_dat_ops;
1584 else /* file blocks */
1585 sc_op = &nilfs_sc_file_ops;
1586 }
1587 bh_org = bh;
1588 get_bh(bh_org);
1589 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1590 &binfo);
1591 if (bh != bh_org)
1592 nilfs_list_replace_buffer(bh_org, bh);
1593 brelse(bh_org);
1594 if (unlikely(err))
1595 goto failed_bmap;
1596
1597 if (ndatablk > 0)
1598 sc_op->write_data_binfo(sci, &ssp, &binfo);
1599 else
1600 sc_op->write_node_binfo(sci, &ssp, &binfo);
1601
1602 blocknr++;
1603 if (--nblocks == 0) {
1604 finfo = NULL;
1605 if (--nfinfo == 0)
1606 break;
1607 } else if (ndatablk > 0)
1608 ndatablk--;
1609 }
1610 out:
1611 return 0;
1612
1613 failed_bmap:
1614 return err;
1615}
1616
1617static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1618{
1619 struct nilfs_segment_buffer *segbuf;
1620 int err;
1621
1622 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1623 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1624 if (unlikely(err))
1625 return err;
1626 nilfs_segbuf_fill_in_segsum(segbuf);
1627 }
1628 return 0;
1629}
1630
1631static void nilfs_begin_page_io(struct page *page)
1632{
1633 if (!page || PageWriteback(page))
1634 /* For split b-tree node pages, this function may be called
1635 twice. We ignore the 2nd or later calls by this check. */
1636 return;
1637
1638 lock_page(page);
1639 clear_page_dirty_for_io(page);
1640 set_page_writeback(page);
1641 unlock_page(page);
1642}
1643
1644static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
1645{
1646 struct nilfs_segment_buffer *segbuf;
1647 struct page *bd_page = NULL, *fs_page = NULL;
1648
1649 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1650 struct buffer_head *bh;
1651
1652 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1653 b_assoc_buffers) {
1654 if (bh->b_page != bd_page) {
1655 if (bd_page) {
1656 lock_page(bd_page);
1657 clear_page_dirty_for_io(bd_page);
1658 set_page_writeback(bd_page);
1659 unlock_page(bd_page);
1660 }
1661 bd_page = bh->b_page;
1662 }
1663 }
1664
1665 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1666 b_assoc_buffers) {
1667 set_buffer_async_write(bh);
1668 if (bh == segbuf->sb_super_root) {
1669 if (bh->b_page != bd_page) {
1670 lock_page(bd_page);
1671 clear_page_dirty_for_io(bd_page);
1672 set_page_writeback(bd_page);
1673 unlock_page(bd_page);
1674 bd_page = bh->b_page;
1675 }
1676 break;
1677 }
1678 if (bh->b_page != fs_page) {
1679 nilfs_begin_page_io(fs_page);
1680 fs_page = bh->b_page;
1681 }
1682 }
1683 }
1684 if (bd_page) {
1685 lock_page(bd_page);
1686 clear_page_dirty_for_io(bd_page);
1687 set_page_writeback(bd_page);
1688 unlock_page(bd_page);
1689 }
1690 nilfs_begin_page_io(fs_page);
1691}
1692
1693static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1694 struct the_nilfs *nilfs)
1695{
1696 int ret;
1697
1698 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1699 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1700 return ret;
1701}
1702
1703static void nilfs_end_page_io(struct page *page, int err)
1704{
1705 if (!page)
1706 return;
1707
1708 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
1709 /*
1710 * For b-tree node pages, this function may be called twice
1711 * or more because they might be split in a segment.
1712 */
1713 if (PageDirty(page)) {
1714 /*
1715 * For pages holding split b-tree node buffers, dirty
1716 * flag on the buffers may be cleared discretely.
1717 * In that case, the page is once redirtied for
1718 * remaining buffers, and it must be cancelled if
1719 * all the buffers get cleaned later.
1720 */
1721 lock_page(page);
1722 if (nilfs_page_buffers_clean(page))
1723 __nilfs_clear_page_dirty(page);
1724 unlock_page(page);
1725 }
1726 return;
1727 }
1728
1729 if (!err) {
1730 if (!nilfs_page_buffers_clean(page))
1731 __set_page_dirty_nobuffers(page);
1732 ClearPageError(page);
1733 } else {
1734 __set_page_dirty_nobuffers(page);
1735 SetPageError(page);
1736 }
1737
1738 end_page_writeback(page);
1739}
1740
1741static void nilfs_abort_logs(struct list_head *logs, int err)
1742{
1743 struct nilfs_segment_buffer *segbuf;
1744 struct page *bd_page = NULL, *fs_page = NULL;
1745 struct buffer_head *bh;
1746
1747 if (list_empty(logs))
1748 return;
1749
1750 list_for_each_entry(segbuf, logs, sb_list) {
1751 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1752 b_assoc_buffers) {
1753 if (bh->b_page != bd_page) {
1754 if (bd_page)
1755 end_page_writeback(bd_page);
1756 bd_page = bh->b_page;
1757 }
1758 }
1759
1760 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1761 b_assoc_buffers) {
1762 clear_buffer_async_write(bh);
1763 if (bh == segbuf->sb_super_root) {
1764 if (bh->b_page != bd_page) {
1765 end_page_writeback(bd_page);
1766 bd_page = bh->b_page;
1767 }
1768 break;
1769 }
1770 if (bh->b_page != fs_page) {
1771 nilfs_end_page_io(fs_page, err);
1772 fs_page = bh->b_page;
1773 }
1774 }
1775 }
1776 if (bd_page)
1777 end_page_writeback(bd_page);
1778
1779 nilfs_end_page_io(fs_page, err);
1780}
1781
1782static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1783 struct the_nilfs *nilfs, int err)
1784{
1785 LIST_HEAD(logs);
1786 int ret;
1787
1788 list_splice_tail_init(&sci->sc_write_logs, &logs);
1789 ret = nilfs_wait_on_logs(&logs);
1790 nilfs_abort_logs(&logs, ret ? : err);
1791
1792 list_splice_tail_init(&sci->sc_segbufs, &logs);
1793 nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1794 nilfs_free_incomplete_logs(&logs, nilfs);
1795
1796 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1797 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1798 sci->sc_freesegs,
1799 sci->sc_nfreesegs,
1800 NULL);
1801 WARN_ON(ret); /* do not happen */
1802 }
1803
1804 nilfs_destroy_logs(&logs);
1805}
1806
1807static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1808 struct nilfs_segment_buffer *segbuf)
1809{
1810 nilfs->ns_segnum = segbuf->sb_segnum;
1811 nilfs->ns_nextnum = segbuf->sb_nextnum;
1812 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1813 + segbuf->sb_sum.nblocks;
1814 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1815 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1816}
1817
1818static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1819{
1820 struct nilfs_segment_buffer *segbuf;
1821 struct page *bd_page = NULL, *fs_page = NULL;
1822 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1823 int update_sr = false;
1824
1825 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1826 struct buffer_head *bh;
1827
1828 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1829 b_assoc_buffers) {
1830 set_buffer_uptodate(bh);
1831 clear_buffer_dirty(bh);
1832 if (bh->b_page != bd_page) {
1833 if (bd_page)
1834 end_page_writeback(bd_page);
1835 bd_page = bh->b_page;
1836 }
1837 }
1838 /*
1839 * We assume that the buffers which belong to the same page
1840 * continue over the buffer list.
1841 * Under this assumption, the last BHs of pages is
1842 * identifiable by the discontinuity of bh->b_page
1843 * (page != fs_page).
1844 *
1845 * For B-tree node blocks, however, this assumption is not
1846 * guaranteed. The cleanup code of B-tree node pages needs
1847 * special care.
1848 */
1849 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1850 b_assoc_buffers) {
1851 const unsigned long set_bits = (1 << BH_Uptodate);
1852 const unsigned long clear_bits =
1853 (1 << BH_Dirty | 1 << BH_Async_Write |
1854 1 << BH_Delay | 1 << BH_NILFS_Volatile |
1855 1 << BH_NILFS_Redirected);
1856
1857 set_mask_bits(&bh->b_state, clear_bits, set_bits);
1858 if (bh == segbuf->sb_super_root) {
1859 if (bh->b_page != bd_page) {
1860 end_page_writeback(bd_page);
1861 bd_page = bh->b_page;
1862 }
1863 update_sr = true;
1864 break;
1865 }
1866 if (bh->b_page != fs_page) {
1867 nilfs_end_page_io(fs_page, 0);
1868 fs_page = bh->b_page;
1869 }
1870 }
1871
1872 if (!nilfs_segbuf_simplex(segbuf)) {
1873 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
1874 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1875 sci->sc_lseg_stime = jiffies;
1876 }
1877 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
1878 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1879 }
1880 }
1881 /*
1882 * Since pages may continue over multiple segment buffers,
1883 * end of the last page must be checked outside of the loop.
1884 */
1885 if (bd_page)
1886 end_page_writeback(bd_page);
1887
1888 nilfs_end_page_io(fs_page, 0);
1889
1890 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1891
1892 if (nilfs_doing_gc())
1893 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1894 else
1895 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1896
1897 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1898
1899 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1900 nilfs_set_next_segment(nilfs, segbuf);
1901
1902 if (update_sr) {
1903 nilfs->ns_flushed_device = 0;
1904 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
1905 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
1906
1907 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
1908 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1909 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1910 nilfs_segctor_clear_metadata_dirty(sci);
1911 } else
1912 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1913}
1914
1915static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
1916{
1917 int ret;
1918
1919 ret = nilfs_wait_on_logs(&sci->sc_write_logs);
1920 if (!ret) {
1921 nilfs_segctor_complete_write(sci);
1922 nilfs_destroy_logs(&sci->sc_write_logs);
1923 }
1924 return ret;
1925}
1926
1927static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci,
1928 struct the_nilfs *nilfs)
1929{
1930 struct nilfs_inode_info *ii, *n;
1931 struct inode *ifile = sci->sc_root->ifile;
1932
1933 spin_lock(&nilfs->ns_inode_lock);
1934 retry:
1935 list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) {
1936 if (!ii->i_bh) {
1937 struct buffer_head *ibh;
1938 int err;
1939
1940 spin_unlock(&nilfs->ns_inode_lock);
1941 err = nilfs_ifile_get_inode_block(
1942 ifile, ii->vfs_inode.i_ino, &ibh);
1943 if (unlikely(err)) {
1944 nilfs_warning(sci->sc_super, __func__,
1945 "failed to get inode block.\n");
1946 return err;
1947 }
1948 mark_buffer_dirty(ibh);
1949 nilfs_mdt_mark_dirty(ifile);
1950 spin_lock(&nilfs->ns_inode_lock);
1951 if (likely(!ii->i_bh))
1952 ii->i_bh = ibh;
1953 else
1954 brelse(ibh);
1955 goto retry;
1956 }
1957
1958 clear_bit(NILFS_I_QUEUED, &ii->i_state);
1959 set_bit(NILFS_I_BUSY, &ii->i_state);
1960 list_move_tail(&ii->i_dirty, &sci->sc_dirty_files);
1961 }
1962 spin_unlock(&nilfs->ns_inode_lock);
1963
1964 return 0;
1965}
1966
1967static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
1968 struct the_nilfs *nilfs)
1969{
1970 struct nilfs_inode_info *ii, *n;
1971 int during_mount = !(sci->sc_super->s_flags & MS_ACTIVE);
1972 int defer_iput = false;
1973
1974 spin_lock(&nilfs->ns_inode_lock);
1975 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
1976 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
1977 test_bit(NILFS_I_DIRTY, &ii->i_state))
1978 continue;
1979
1980 clear_bit(NILFS_I_BUSY, &ii->i_state);
1981 brelse(ii->i_bh);
1982 ii->i_bh = NULL;
1983 list_del_init(&ii->i_dirty);
1984 if (!ii->vfs_inode.i_nlink || during_mount) {
1985 /*
1986 * Defer calling iput() to avoid deadlocks if
1987 * i_nlink == 0 or mount is not yet finished.
1988 */
1989 list_add_tail(&ii->i_dirty, &sci->sc_iput_queue);
1990 defer_iput = true;
1991 } else {
1992 spin_unlock(&nilfs->ns_inode_lock);
1993 iput(&ii->vfs_inode);
1994 spin_lock(&nilfs->ns_inode_lock);
1995 }
1996 }
1997 spin_unlock(&nilfs->ns_inode_lock);
1998
1999 if (defer_iput)
2000 schedule_work(&sci->sc_iput_work);
2001}
2002
2003/*
2004 * Main procedure of segment constructor
2005 */
2006static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2007{
2008 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2009 int err;
2010
2011 nilfs_sc_cstage_set(sci, NILFS_ST_INIT);
2012 sci->sc_cno = nilfs->ns_cno;
2013
2014 err = nilfs_segctor_collect_dirty_files(sci, nilfs);
2015 if (unlikely(err))
2016 goto out;
2017
2018 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
2019 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2020
2021 if (nilfs_segctor_clean(sci))
2022 goto out;
2023
2024 do {
2025 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2026
2027 err = nilfs_segctor_begin_construction(sci, nilfs);
2028 if (unlikely(err))
2029 goto out;
2030
2031 /* Update time stamp */
2032 sci->sc_seg_ctime = get_seconds();
2033
2034 err = nilfs_segctor_collect(sci, nilfs, mode);
2035 if (unlikely(err))
2036 goto failed;
2037
2038 /* Avoid empty segment */
2039 if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE &&
2040 nilfs_segbuf_empty(sci->sc_curseg)) {
2041 nilfs_segctor_abort_construction(sci, nilfs, 1);
2042 goto out;
2043 }
2044
2045 err = nilfs_segctor_assign(sci, mode);
2046 if (unlikely(err))
2047 goto failed;
2048
2049 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2050 nilfs_segctor_fill_in_file_bmap(sci);
2051
2052 if (mode == SC_LSEG_SR &&
2053 nilfs_sc_cstage_get(sci) >= NILFS_ST_CPFILE) {
2054 err = nilfs_segctor_fill_in_checkpoint(sci);
2055 if (unlikely(err))
2056 goto failed_to_write;
2057
2058 nilfs_segctor_fill_in_super_root(sci, nilfs);
2059 }
2060 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2061
2062 /* Write partial segments */
2063 nilfs_segctor_prepare_write(sci);
2064
2065 nilfs_add_checksums_on_logs(&sci->sc_segbufs,
2066 nilfs->ns_crc_seed);
2067
2068 err = nilfs_segctor_write(sci, nilfs);
2069 if (unlikely(err))
2070 goto failed_to_write;
2071
2072 if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE ||
2073 nilfs->ns_blocksize_bits != PAGE_SHIFT) {
2074 /*
2075 * At this point, we avoid double buffering
2076 * for blocksize < pagesize because page dirty
2077 * flag is turned off during write and dirty
2078 * buffers are not properly collected for
2079 * pages crossing over segments.
2080 */
2081 err = nilfs_segctor_wait(sci);
2082 if (err)
2083 goto failed_to_write;
2084 }
2085 } while (nilfs_sc_cstage_get(sci) != NILFS_ST_DONE);
2086
2087 out:
2088 nilfs_segctor_drop_written_files(sci, nilfs);
2089 return err;
2090
2091 failed_to_write:
2092 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2093 nilfs_redirty_inodes(&sci->sc_dirty_files);
2094
2095 failed:
2096 if (nilfs_doing_gc())
2097 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2098 nilfs_segctor_abort_construction(sci, nilfs, err);
2099 goto out;
2100}
2101
2102/**
2103 * nilfs_segctor_start_timer - set timer of background write
2104 * @sci: nilfs_sc_info
2105 *
2106 * If the timer has already been set, it ignores the new request.
2107 * This function MUST be called within a section locking the segment
2108 * semaphore.
2109 */
2110static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2111{
2112 spin_lock(&sci->sc_state_lock);
2113 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2114 sci->sc_timer.expires = jiffies + sci->sc_interval;
2115 add_timer(&sci->sc_timer);
2116 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2117 }
2118 spin_unlock(&sci->sc_state_lock);
2119}
2120
2121static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2122{
2123 spin_lock(&sci->sc_state_lock);
2124 if (!(sci->sc_flush_request & (1 << bn))) {
2125 unsigned long prev_req = sci->sc_flush_request;
2126
2127 sci->sc_flush_request |= (1 << bn);
2128 if (!prev_req)
2129 wake_up(&sci->sc_wait_daemon);
2130 }
2131 spin_unlock(&sci->sc_state_lock);
2132}
2133
2134/**
2135 * nilfs_flush_segment - trigger a segment construction for resource control
2136 * @sb: super block
2137 * @ino: inode number of the file to be flushed out.
2138 */
2139void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2140{
2141 struct the_nilfs *nilfs = sb->s_fs_info;
2142 struct nilfs_sc_info *sci = nilfs->ns_writer;
2143
2144 if (!sci || nilfs_doing_construction())
2145 return;
2146 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2147 /* assign bit 0 to data files */
2148}
2149
2150struct nilfs_segctor_wait_request {
2151 wait_queue_t wq;
2152 __u32 seq;
2153 int err;
2154 atomic_t done;
2155};
2156
2157static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2158{
2159 struct nilfs_segctor_wait_request wait_req;
2160 int err = 0;
2161
2162 spin_lock(&sci->sc_state_lock);
2163 init_wait(&wait_req.wq);
2164 wait_req.err = 0;
2165 atomic_set(&wait_req.done, 0);
2166 wait_req.seq = ++sci->sc_seq_request;
2167 spin_unlock(&sci->sc_state_lock);
2168
2169 init_waitqueue_entry(&wait_req.wq, current);
2170 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2171 set_current_state(TASK_INTERRUPTIBLE);
2172 wake_up(&sci->sc_wait_daemon);
2173
2174 for (;;) {
2175 if (atomic_read(&wait_req.done)) {
2176 err = wait_req.err;
2177 break;
2178 }
2179 if (!signal_pending(current)) {
2180 schedule();
2181 continue;
2182 }
2183 err = -ERESTARTSYS;
2184 break;
2185 }
2186 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2187 return err;
2188}
2189
2190static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2191{
2192 struct nilfs_segctor_wait_request *wrq, *n;
2193 unsigned long flags;
2194
2195 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2196 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2197 wq.task_list) {
2198 if (!atomic_read(&wrq->done) &&
2199 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2200 wrq->err = err;
2201 atomic_set(&wrq->done, 1);
2202 }
2203 if (atomic_read(&wrq->done)) {
2204 wrq->wq.func(&wrq->wq,
2205 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2206 0, NULL);
2207 }
2208 }
2209 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2210}
2211
2212/**
2213 * nilfs_construct_segment - construct a logical segment
2214 * @sb: super block
2215 *
2216 * Return Value: On success, 0 is retured. On errors, one of the following
2217 * negative error code is returned.
2218 *
2219 * %-EROFS - Read only filesystem.
2220 *
2221 * %-EIO - I/O error
2222 *
2223 * %-ENOSPC - No space left on device (only in a panic state).
2224 *
2225 * %-ERESTARTSYS - Interrupted.
2226 *
2227 * %-ENOMEM - Insufficient memory available.
2228 */
2229int nilfs_construct_segment(struct super_block *sb)
2230{
2231 struct the_nilfs *nilfs = sb->s_fs_info;
2232 struct nilfs_sc_info *sci = nilfs->ns_writer;
2233 struct nilfs_transaction_info *ti;
2234 int err;
2235
2236 if (!sci)
2237 return -EROFS;
2238
2239 /* A call inside transactions causes a deadlock. */
2240 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2241
2242 err = nilfs_segctor_sync(sci);
2243 return err;
2244}
2245
2246/**
2247 * nilfs_construct_dsync_segment - construct a data-only logical segment
2248 * @sb: super block
2249 * @inode: inode whose data blocks should be written out
2250 * @start: start byte offset
2251 * @end: end byte offset (inclusive)
2252 *
2253 * Return Value: On success, 0 is retured. On errors, one of the following
2254 * negative error code is returned.
2255 *
2256 * %-EROFS - Read only filesystem.
2257 *
2258 * %-EIO - I/O error
2259 *
2260 * %-ENOSPC - No space left on device (only in a panic state).
2261 *
2262 * %-ERESTARTSYS - Interrupted.
2263 *
2264 * %-ENOMEM - Insufficient memory available.
2265 */
2266int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2267 loff_t start, loff_t end)
2268{
2269 struct the_nilfs *nilfs = sb->s_fs_info;
2270 struct nilfs_sc_info *sci = nilfs->ns_writer;
2271 struct nilfs_inode_info *ii;
2272 struct nilfs_transaction_info ti;
2273 int err = 0;
2274
2275 if (!sci)
2276 return -EROFS;
2277
2278 nilfs_transaction_lock(sb, &ti, 0);
2279
2280 ii = NILFS_I(inode);
2281 if (test_bit(NILFS_I_INODE_SYNC, &ii->i_state) ||
2282 nilfs_test_opt(nilfs, STRICT_ORDER) ||
2283 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2284 nilfs_discontinued(nilfs)) {
2285 nilfs_transaction_unlock(sb);
2286 err = nilfs_segctor_sync(sci);
2287 return err;
2288 }
2289
2290 spin_lock(&nilfs->ns_inode_lock);
2291 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2292 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2293 spin_unlock(&nilfs->ns_inode_lock);
2294 nilfs_transaction_unlock(sb);
2295 return 0;
2296 }
2297 spin_unlock(&nilfs->ns_inode_lock);
2298 sci->sc_dsync_inode = ii;
2299 sci->sc_dsync_start = start;
2300 sci->sc_dsync_end = end;
2301
2302 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2303 if (!err)
2304 nilfs->ns_flushed_device = 0;
2305
2306 nilfs_transaction_unlock(sb);
2307 return err;
2308}
2309
2310#define FLUSH_FILE_BIT (0x1) /* data file only */
2311#define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2312
2313/**
2314 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2315 * @sci: segment constructor object
2316 */
2317static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2318{
2319 spin_lock(&sci->sc_state_lock);
2320 sci->sc_seq_accepted = sci->sc_seq_request;
2321 spin_unlock(&sci->sc_state_lock);
2322 del_timer_sync(&sci->sc_timer);
2323}
2324
2325/**
2326 * nilfs_segctor_notify - notify the result of request to caller threads
2327 * @sci: segment constructor object
2328 * @mode: mode of log forming
2329 * @err: error code to be notified
2330 */
2331static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2332{
2333 /* Clear requests (even when the construction failed) */
2334 spin_lock(&sci->sc_state_lock);
2335
2336 if (mode == SC_LSEG_SR) {
2337 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2338 sci->sc_seq_done = sci->sc_seq_accepted;
2339 nilfs_segctor_wakeup(sci, err);
2340 sci->sc_flush_request = 0;
2341 } else {
2342 if (mode == SC_FLUSH_FILE)
2343 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2344 else if (mode == SC_FLUSH_DAT)
2345 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2346
2347 /* re-enable timer if checkpoint creation was not done */
2348 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2349 time_before(jiffies, sci->sc_timer.expires))
2350 add_timer(&sci->sc_timer);
2351 }
2352 spin_unlock(&sci->sc_state_lock);
2353}
2354
2355/**
2356 * nilfs_segctor_construct - form logs and write them to disk
2357 * @sci: segment constructor object
2358 * @mode: mode of log forming
2359 */
2360static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2361{
2362 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2363 struct nilfs_super_block **sbp;
2364 int err = 0;
2365
2366 nilfs_segctor_accept(sci);
2367
2368 if (nilfs_discontinued(nilfs))
2369 mode = SC_LSEG_SR;
2370 if (!nilfs_segctor_confirm(sci))
2371 err = nilfs_segctor_do_construct(sci, mode);
2372
2373 if (likely(!err)) {
2374 if (mode != SC_FLUSH_DAT)
2375 atomic_set(&nilfs->ns_ndirtyblks, 0);
2376 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2377 nilfs_discontinued(nilfs)) {
2378 down_write(&nilfs->ns_sem);
2379 err = -EIO;
2380 sbp = nilfs_prepare_super(sci->sc_super,
2381 nilfs_sb_will_flip(nilfs));
2382 if (likely(sbp)) {
2383 nilfs_set_log_cursor(sbp[0], nilfs);
2384 err = nilfs_commit_super(sci->sc_super,
2385 NILFS_SB_COMMIT);
2386 }
2387 up_write(&nilfs->ns_sem);
2388 }
2389 }
2390
2391 nilfs_segctor_notify(sci, mode, err);
2392 return err;
2393}
2394
2395static void nilfs_construction_timeout(unsigned long data)
2396{
2397 struct task_struct *p = (struct task_struct *)data;
2398 wake_up_process(p);
2399}
2400
2401static void
2402nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2403{
2404 struct nilfs_inode_info *ii, *n;
2405
2406 list_for_each_entry_safe(ii, n, head, i_dirty) {
2407 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2408 continue;
2409 list_del_init(&ii->i_dirty);
2410 truncate_inode_pages(&ii->vfs_inode.i_data, 0);
2411 nilfs_btnode_cache_clear(&ii->i_btnode_cache);
2412 iput(&ii->vfs_inode);
2413 }
2414}
2415
2416int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2417 void **kbufs)
2418{
2419 struct the_nilfs *nilfs = sb->s_fs_info;
2420 struct nilfs_sc_info *sci = nilfs->ns_writer;
2421 struct nilfs_transaction_info ti;
2422 int err;
2423
2424 if (unlikely(!sci))
2425 return -EROFS;
2426
2427 nilfs_transaction_lock(sb, &ti, 1);
2428
2429 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2430 if (unlikely(err))
2431 goto out_unlock;
2432
2433 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2434 if (unlikely(err)) {
2435 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2436 goto out_unlock;
2437 }
2438
2439 sci->sc_freesegs = kbufs[4];
2440 sci->sc_nfreesegs = argv[4].v_nmembs;
2441 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2442
2443 for (;;) {
2444 err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2445 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2446
2447 if (likely(!err))
2448 break;
2449
2450 nilfs_warning(sb, __func__,
2451 "segment construction failed. (err=%d)", err);
2452 set_current_state(TASK_INTERRUPTIBLE);
2453 schedule_timeout(sci->sc_interval);
2454 }
2455 if (nilfs_test_opt(nilfs, DISCARD)) {
2456 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2457 sci->sc_nfreesegs);
2458 if (ret) {
2459 printk(KERN_WARNING
2460 "NILFS warning: error %d on discard request, "
2461 "turning discards off for the device\n", ret);
2462 nilfs_clear_opt(nilfs, DISCARD);
2463 }
2464 }
2465
2466 out_unlock:
2467 sci->sc_freesegs = NULL;
2468 sci->sc_nfreesegs = 0;
2469 nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2470 nilfs_transaction_unlock(sb);
2471 return err;
2472}
2473
2474static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2475{
2476 struct nilfs_transaction_info ti;
2477
2478 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2479 nilfs_segctor_construct(sci, mode);
2480
2481 /*
2482 * Unclosed segment should be retried. We do this using sc_timer.
2483 * Timeout of sc_timer will invoke complete construction which leads
2484 * to close the current logical segment.
2485 */
2486 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2487 nilfs_segctor_start_timer(sci);
2488
2489 nilfs_transaction_unlock(sci->sc_super);
2490}
2491
2492static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2493{
2494 int mode = 0;
2495
2496 spin_lock(&sci->sc_state_lock);
2497 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2498 SC_FLUSH_DAT : SC_FLUSH_FILE;
2499 spin_unlock(&sci->sc_state_lock);
2500
2501 if (mode) {
2502 nilfs_segctor_do_construct(sci, mode);
2503
2504 spin_lock(&sci->sc_state_lock);
2505 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2506 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2507 spin_unlock(&sci->sc_state_lock);
2508 }
2509 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2510}
2511
2512static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2513{
2514 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2515 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2516 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2517 return SC_FLUSH_FILE;
2518 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2519 return SC_FLUSH_DAT;
2520 }
2521 return SC_LSEG_SR;
2522}
2523
2524/**
2525 * nilfs_segctor_thread - main loop of the segment constructor thread.
2526 * @arg: pointer to a struct nilfs_sc_info.
2527 *
2528 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2529 * to execute segment constructions.
2530 */
2531static int nilfs_segctor_thread(void *arg)
2532{
2533 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2534 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2535 int timeout = 0;
2536
2537 sci->sc_timer.data = (unsigned long)current;
2538 sci->sc_timer.function = nilfs_construction_timeout;
2539
2540 /* start sync. */
2541 sci->sc_task = current;
2542 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2543 printk(KERN_INFO
2544 "segctord starting. Construction interval = %lu seconds, "
2545 "CP frequency < %lu seconds\n",
2546 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2547
2548 spin_lock(&sci->sc_state_lock);
2549 loop:
2550 for (;;) {
2551 int mode;
2552
2553 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2554 goto end_thread;
2555
2556 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2557 mode = SC_LSEG_SR;
2558 else if (!sci->sc_flush_request)
2559 break;
2560 else
2561 mode = nilfs_segctor_flush_mode(sci);
2562
2563 spin_unlock(&sci->sc_state_lock);
2564 nilfs_segctor_thread_construct(sci, mode);
2565 spin_lock(&sci->sc_state_lock);
2566 timeout = 0;
2567 }
2568
2569
2570 if (freezing(current)) {
2571 spin_unlock(&sci->sc_state_lock);
2572 try_to_freeze();
2573 spin_lock(&sci->sc_state_lock);
2574 } else {
2575 DEFINE_WAIT(wait);
2576 int should_sleep = 1;
2577
2578 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2579 TASK_INTERRUPTIBLE);
2580
2581 if (sci->sc_seq_request != sci->sc_seq_done)
2582 should_sleep = 0;
2583 else if (sci->sc_flush_request)
2584 should_sleep = 0;
2585 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2586 should_sleep = time_before(jiffies,
2587 sci->sc_timer.expires);
2588
2589 if (should_sleep) {
2590 spin_unlock(&sci->sc_state_lock);
2591 schedule();
2592 spin_lock(&sci->sc_state_lock);
2593 }
2594 finish_wait(&sci->sc_wait_daemon, &wait);
2595 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2596 time_after_eq(jiffies, sci->sc_timer.expires));
2597
2598 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2599 set_nilfs_discontinued(nilfs);
2600 }
2601 goto loop;
2602
2603 end_thread:
2604 spin_unlock(&sci->sc_state_lock);
2605
2606 /* end sync. */
2607 sci->sc_task = NULL;
2608 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2609 return 0;
2610}
2611
2612static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2613{
2614 struct task_struct *t;
2615
2616 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2617 if (IS_ERR(t)) {
2618 int err = PTR_ERR(t);
2619
2620 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2621 err);
2622 return err;
2623 }
2624 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2625 return 0;
2626}
2627
2628static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2629 __acquires(&sci->sc_state_lock)
2630 __releases(&sci->sc_state_lock)
2631{
2632 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2633
2634 while (sci->sc_task) {
2635 wake_up(&sci->sc_wait_daemon);
2636 spin_unlock(&sci->sc_state_lock);
2637 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2638 spin_lock(&sci->sc_state_lock);
2639 }
2640}
2641
2642/*
2643 * Setup & clean-up functions
2644 */
2645static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
2646 struct nilfs_root *root)
2647{
2648 struct the_nilfs *nilfs = sb->s_fs_info;
2649 struct nilfs_sc_info *sci;
2650
2651 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2652 if (!sci)
2653 return NULL;
2654
2655 sci->sc_super = sb;
2656
2657 nilfs_get_root(root);
2658 sci->sc_root = root;
2659
2660 init_waitqueue_head(&sci->sc_wait_request);
2661 init_waitqueue_head(&sci->sc_wait_daemon);
2662 init_waitqueue_head(&sci->sc_wait_task);
2663 spin_lock_init(&sci->sc_state_lock);
2664 INIT_LIST_HEAD(&sci->sc_dirty_files);
2665 INIT_LIST_HEAD(&sci->sc_segbufs);
2666 INIT_LIST_HEAD(&sci->sc_write_logs);
2667 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2668 INIT_LIST_HEAD(&sci->sc_iput_queue);
2669 INIT_WORK(&sci->sc_iput_work, nilfs_iput_work_func);
2670 init_timer(&sci->sc_timer);
2671
2672 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2673 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2674 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2675
2676 if (nilfs->ns_interval)
2677 sci->sc_interval = HZ * nilfs->ns_interval;
2678 if (nilfs->ns_watermark)
2679 sci->sc_watermark = nilfs->ns_watermark;
2680 return sci;
2681}
2682
2683static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2684{
2685 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2686
2687 /* The segctord thread was stopped and its timer was removed.
2688 But some tasks remain. */
2689 do {
2690 struct nilfs_transaction_info ti;
2691
2692 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2693 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2694 nilfs_transaction_unlock(sci->sc_super);
2695
2696 flush_work(&sci->sc_iput_work);
2697
2698 } while (ret && retrycount-- > 0);
2699}
2700
2701/**
2702 * nilfs_segctor_destroy - destroy the segment constructor.
2703 * @sci: nilfs_sc_info
2704 *
2705 * nilfs_segctor_destroy() kills the segctord thread and frees
2706 * the nilfs_sc_info struct.
2707 * Caller must hold the segment semaphore.
2708 */
2709static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2710{
2711 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2712 int flag;
2713
2714 up_write(&nilfs->ns_segctor_sem);
2715
2716 spin_lock(&sci->sc_state_lock);
2717 nilfs_segctor_kill_thread(sci);
2718 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2719 || sci->sc_seq_request != sci->sc_seq_done);
2720 spin_unlock(&sci->sc_state_lock);
2721
2722 if (flush_work(&sci->sc_iput_work))
2723 flag = true;
2724
2725 if (flag || !nilfs_segctor_confirm(sci))
2726 nilfs_segctor_write_out(sci);
2727
2728 if (!list_empty(&sci->sc_dirty_files)) {
2729 nilfs_warning(sci->sc_super, __func__,
2730 "dirty file(s) after the final construction\n");
2731 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
2732 }
2733
2734 if (!list_empty(&sci->sc_iput_queue)) {
2735 nilfs_warning(sci->sc_super, __func__,
2736 "iput queue is not empty\n");
2737 nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 1);
2738 }
2739
2740 WARN_ON(!list_empty(&sci->sc_segbufs));
2741 WARN_ON(!list_empty(&sci->sc_write_logs));
2742
2743 nilfs_put_root(sci->sc_root);
2744
2745 down_write(&nilfs->ns_segctor_sem);
2746
2747 del_timer_sync(&sci->sc_timer);
2748 kfree(sci);
2749}
2750
2751/**
2752 * nilfs_attach_log_writer - attach log writer
2753 * @sb: super block instance
2754 * @root: root object of the current filesystem tree
2755 *
2756 * This allocates a log writer object, initializes it, and starts the
2757 * log writer.
2758 *
2759 * Return Value: On success, 0 is returned. On error, one of the following
2760 * negative error code is returned.
2761 *
2762 * %-ENOMEM - Insufficient memory available.
2763 */
2764int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
2765{
2766 struct the_nilfs *nilfs = sb->s_fs_info;
2767 int err;
2768
2769 if (nilfs->ns_writer) {
2770 /*
2771 * This happens if the filesystem was remounted
2772 * read/write after nilfs_error degenerated it into a
2773 * read-only mount.
2774 */
2775 nilfs_detach_log_writer(sb);
2776 }
2777
2778 nilfs->ns_writer = nilfs_segctor_new(sb, root);
2779 if (!nilfs->ns_writer)
2780 return -ENOMEM;
2781
2782 err = nilfs_segctor_start_thread(nilfs->ns_writer);
2783 if (err) {
2784 kfree(nilfs->ns_writer);
2785 nilfs->ns_writer = NULL;
2786 }
2787 return err;
2788}
2789
2790/**
2791 * nilfs_detach_log_writer - destroy log writer
2792 * @sb: super block instance
2793 *
2794 * This kills log writer daemon, frees the log writer object, and
2795 * destroys list of dirty files.
2796 */
2797void nilfs_detach_log_writer(struct super_block *sb)
2798{
2799 struct the_nilfs *nilfs = sb->s_fs_info;
2800 LIST_HEAD(garbage_list);
2801
2802 down_write(&nilfs->ns_segctor_sem);
2803 if (nilfs->ns_writer) {
2804 nilfs_segctor_destroy(nilfs->ns_writer);
2805 nilfs->ns_writer = NULL;
2806 }
2807
2808 /* Force to free the list of dirty files */
2809 spin_lock(&nilfs->ns_inode_lock);
2810 if (!list_empty(&nilfs->ns_dirty_files)) {
2811 list_splice_init(&nilfs->ns_dirty_files, &garbage_list);
2812 nilfs_warning(sb, __func__,
2813 "Hit dirty file after stopped log writer\n");
2814 }
2815 spin_unlock(&nilfs->ns_inode_lock);
2816 up_write(&nilfs->ns_segctor_sem);
2817
2818 nilfs_dispose_list(nilfs, &garbage_list, 1);
2819}