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ceph: fix inode reference leak
[linux/fpc-iii.git] / fs / nilfs2 / segment.c
blob4317f72568e60651709149497c8c027e608cf773
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 */
56 enum {
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 */
67 enum {
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 */
93 static 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
99 static 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
105 static 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 */
117 struct 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 */
135 static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
136 static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
137 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
138 static 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
149 static 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 */
211 int 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 */
266 int 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
302 void 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
325 void 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
348 static 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
383 static 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
398 static 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 */
421 static 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
443 static 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
453 static 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 */
473 static 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
485 static 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
499 static 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
533 static 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 */
571 static 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
587 static 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
594 static 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
602 static 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
611 static 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
620 static 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
628 static 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
643 static 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
651 static 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
660 static 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
669 static 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
677 static 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
685 static 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
744 static 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
775 static 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
808 static 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
817 static 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
833 static 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
841 static 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
857 static 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
867 static 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
891 static 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
929 static 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
946 static 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
956 static 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
983 static 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
993 static 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
1006 static 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
1037 static 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
1044 static 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
1097 static 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
1118 static 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 */
1278 static 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
1338 static 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
1394 static 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
1431 static 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
1448 static 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
1466 static 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
1482 static 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
1535 static 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
1544 static int
1545 nilfs_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
1617 static 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
1631 static 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
1644 static 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
1693 static 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
1703 static 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
1741 static 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
1782 static 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
1807 static 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
1818 static 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
1915 static 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
1927 static 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
1967 static 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 */
2006 static 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 */
2110 static 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
2121 static 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 */
2139 void 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
2150 struct nilfs_segctor_wait_request {
2151 wait_queue_t wq;
2152 __u32 seq;
2153 int err;
2154 atomic_t done;
2155 };
2156
2157 static 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
2190 static 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 */
2229 int 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 */
2266 int 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 */
2317 static 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 */
2331 static 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 */
2360 static 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
2395 static void nilfs_construction_timeout(unsigned long data)
2396 {
2397 struct task_struct *p = (struct task_struct *)data;
2398 wake_up_process(p);
2399 }
2400
2401 static void
2402 nilfs_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
2416 int 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
2474 static 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
2492 static 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
2512 static 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 */
2531 static 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
2612 static 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
2628 static 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 */
2645 static 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
2683 static 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 */
2709 static 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 */
2764 int 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 */
2797 void 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 }
Linux with added FPC-III support