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Linux 4.9.169
[linux/fpc-iii.git] / fs / nilfs2 / segment.c
blob36362d4bc344feeee0e2befaad8a32a59675170a
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 "nilfs.h"
34 #include "btnode.h"
35 #include "page.h"
36 #include "segment.h"
37 #include "sufile.h"
38 #include "cpfile.h"
39 #include "ifile.h"
40 #include "segbuf.h"
41
42
43 /*
44 * Segment constructor
45 */
46 #define SC_N_INODEVEC 16 /* Size of locally allocated inode vector */
47
48 #define SC_MAX_SEGDELTA 64 /*
49 * Upper limit of the number of segments
50 * appended in collection retry loop
51 */
52
53 /* Construction mode */
54 enum {
55 SC_LSEG_SR = 1, /* Make a logical segment having a super root */
56 SC_LSEG_DSYNC, /*
57 * Flush data blocks of a given file and make
58 * a logical segment without a super root.
59 */
60 SC_FLUSH_FILE, /*
61 * Flush data files, leads to segment writes without
62 * creating a checkpoint.
63 */
64 SC_FLUSH_DAT, /*
65 * Flush DAT file. This also creates segments
66 * without a checkpoint.
67 */
68 };
69
70 /* Stage numbers of dirty block collection */
71 enum {
72 NILFS_ST_INIT = 0,
73 NILFS_ST_GC, /* Collecting dirty blocks for GC */
74 NILFS_ST_FILE,
75 NILFS_ST_IFILE,
76 NILFS_ST_CPFILE,
77 NILFS_ST_SUFILE,
78 NILFS_ST_DAT,
79 NILFS_ST_SR, /* Super root */
80 NILFS_ST_DSYNC, /* Data sync blocks */
81 NILFS_ST_DONE,
82 };
83
84 #define CREATE_TRACE_POINTS
85 #include <trace/events/nilfs2.h>
86
87 /*
88 * nilfs_sc_cstage_inc(), nilfs_sc_cstage_set(), nilfs_sc_cstage_get() are
89 * wrapper functions of stage count (nilfs_sc_info->sc_stage.scnt). Users of
90 * the variable must use them because transition of stage count must involve
91 * trace events (trace_nilfs2_collection_stage_transition).
92 *
93 * nilfs_sc_cstage_get() isn't required for the above purpose because it doesn't
94 * produce tracepoint events. It is provided just for making the intention
95 * clear.
96 */
97 static inline void nilfs_sc_cstage_inc(struct nilfs_sc_info *sci)
98 {
99 sci->sc_stage.scnt++;
100 trace_nilfs2_collection_stage_transition(sci);
101 }
102
103 static inline void nilfs_sc_cstage_set(struct nilfs_sc_info *sci, int next_scnt)
104 {
105 sci->sc_stage.scnt = next_scnt;
106 trace_nilfs2_collection_stage_transition(sci);
107 }
108
109 static inline int nilfs_sc_cstage_get(struct nilfs_sc_info *sci)
110 {
111 return sci->sc_stage.scnt;
112 }
113
114 /* State flags of collection */
115 #define NILFS_CF_NODE 0x0001 /* Collecting node blocks */
116 #define NILFS_CF_IFILE_STARTED 0x0002 /* IFILE stage has started */
117 #define NILFS_CF_SUFREED 0x0004 /* segment usages has been freed */
118 #define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED)
119
120 /* Operations depending on the construction mode and file type */
121 struct nilfs_sc_operations {
122 int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *,
123 struct inode *);
124 int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *,
125 struct inode *);
126 int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *,
127 struct inode *);
128 void (*write_data_binfo)(struct nilfs_sc_info *,
129 struct nilfs_segsum_pointer *,
130 union nilfs_binfo *);
131 void (*write_node_binfo)(struct nilfs_sc_info *,
132 struct nilfs_segsum_pointer *,
133 union nilfs_binfo *);
134 };
135
136 /*
137 * Other definitions
138 */
139 static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
140 static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
141 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
142 static void nilfs_dispose_list(struct the_nilfs *, struct list_head *, int);
143
144 #define nilfs_cnt32_gt(a, b) \
145 (typecheck(__u32, a) && typecheck(__u32, b) && \
146 ((__s32)(b) - (__s32)(a) < 0))
147 #define nilfs_cnt32_ge(a, b) \
148 (typecheck(__u32, a) && typecheck(__u32, b) && \
149 ((__s32)(a) - (__s32)(b) >= 0))
150 #define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a)
151 #define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a)
152
153 static int nilfs_prepare_segment_lock(struct super_block *sb,
154 struct nilfs_transaction_info *ti)
155 {
156 struct nilfs_transaction_info *cur_ti = current->journal_info;
157 void *save = NULL;
158
159 if (cur_ti) {
160 if (cur_ti->ti_magic == NILFS_TI_MAGIC)
161 return ++cur_ti->ti_count;
162
163 /*
164 * If journal_info field is occupied by other FS,
165 * it is saved and will be restored on
166 * nilfs_transaction_commit().
167 */
168 nilfs_msg(sb, KERN_WARNING, "journal info from a different FS");
169 save = current->journal_info;
170 }
171 if (!ti) {
172 ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
173 if (!ti)
174 return -ENOMEM;
175 ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
176 } else {
177 ti->ti_flags = 0;
178 }
179 ti->ti_count = 0;
180 ti->ti_save = save;
181 ti->ti_magic = NILFS_TI_MAGIC;
182 current->journal_info = ti;
183 return 0;
184 }
185
186 /**
187 * nilfs_transaction_begin - start indivisible file operations.
188 * @sb: super block
189 * @ti: nilfs_transaction_info
190 * @vacancy_check: flags for vacancy rate checks
191 *
192 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
193 * the segment semaphore, to make a segment construction and write tasks
194 * exclusive. The function is used with nilfs_transaction_commit() in pairs.
195 * The region enclosed by these two functions can be nested. To avoid a
196 * deadlock, the semaphore is only acquired or released in the outermost call.
197 *
198 * This function allocates a nilfs_transaction_info struct to keep context
199 * information on it. It is initialized and hooked onto the current task in
200 * the outermost call. If a pre-allocated struct is given to @ti, it is used
201 * instead; otherwise a new struct is assigned from a slab.
202 *
203 * When @vacancy_check flag is set, this function will check the amount of
204 * free space, and will wait for the GC to reclaim disk space if low capacity.
205 *
206 * Return Value: On success, 0 is returned. On error, one of the following
207 * negative error code is returned.
208 *
209 * %-ENOMEM - Insufficient memory available.
210 *
211 * %-ENOSPC - No space left on device
212 */
213 int nilfs_transaction_begin(struct super_block *sb,
214 struct nilfs_transaction_info *ti,
215 int vacancy_check)
216 {
217 struct the_nilfs *nilfs;
218 int ret = nilfs_prepare_segment_lock(sb, ti);
219 struct nilfs_transaction_info *trace_ti;
220
221 if (unlikely(ret < 0))
222 return ret;
223 if (ret > 0) {
224 trace_ti = current->journal_info;
225
226 trace_nilfs2_transaction_transition(sb, trace_ti,
227 trace_ti->ti_count, trace_ti->ti_flags,
228 TRACE_NILFS2_TRANSACTION_BEGIN);
229 return 0;
230 }
231
232 sb_start_intwrite(sb);
233
234 nilfs = sb->s_fs_info;
235 down_read(&nilfs->ns_segctor_sem);
236 if (vacancy_check && nilfs_near_disk_full(nilfs)) {
237 up_read(&nilfs->ns_segctor_sem);
238 ret = -ENOSPC;
239 goto failed;
240 }
241
242 trace_ti = current->journal_info;
243 trace_nilfs2_transaction_transition(sb, trace_ti, trace_ti->ti_count,
244 trace_ti->ti_flags,
245 TRACE_NILFS2_TRANSACTION_BEGIN);
246 return 0;
247
248 failed:
249 ti = current->journal_info;
250 current->journal_info = ti->ti_save;
251 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
252 kmem_cache_free(nilfs_transaction_cachep, ti);
253 sb_end_intwrite(sb);
254 return ret;
255 }
256
257 /**
258 * nilfs_transaction_commit - commit indivisible file operations.
259 * @sb: super block
260 *
261 * nilfs_transaction_commit() releases the read semaphore which is
262 * acquired by nilfs_transaction_begin(). This is only performed
263 * in outermost call of this function. If a commit flag is set,
264 * nilfs_transaction_commit() sets a timer to start the segment
265 * constructor. If a sync flag is set, it starts construction
266 * directly.
267 */
268 int nilfs_transaction_commit(struct super_block *sb)
269 {
270 struct nilfs_transaction_info *ti = current->journal_info;
271 struct the_nilfs *nilfs = sb->s_fs_info;
272 int err = 0;
273
274 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
275 ti->ti_flags |= NILFS_TI_COMMIT;
276 if (ti->ti_count > 0) {
277 ti->ti_count--;
278 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
279 ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
280 return 0;
281 }
282 if (nilfs->ns_writer) {
283 struct nilfs_sc_info *sci = nilfs->ns_writer;
284
285 if (ti->ti_flags & NILFS_TI_COMMIT)
286 nilfs_segctor_start_timer(sci);
287 if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark)
288 nilfs_segctor_do_flush(sci, 0);
289 }
290 up_read(&nilfs->ns_segctor_sem);
291 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
292 ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
293
294 current->journal_info = ti->ti_save;
295
296 if (ti->ti_flags & NILFS_TI_SYNC)
297 err = nilfs_construct_segment(sb);
298 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
299 kmem_cache_free(nilfs_transaction_cachep, ti);
300 sb_end_intwrite(sb);
301 return err;
302 }
303
304 void nilfs_transaction_abort(struct super_block *sb)
305 {
306 struct nilfs_transaction_info *ti = current->journal_info;
307 struct the_nilfs *nilfs = sb->s_fs_info;
308
309 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
310 if (ti->ti_count > 0) {
311 ti->ti_count--;
312 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
313 ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
314 return;
315 }
316 up_read(&nilfs->ns_segctor_sem);
317
318 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
319 ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
320
321 current->journal_info = ti->ti_save;
322 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
323 kmem_cache_free(nilfs_transaction_cachep, ti);
324 sb_end_intwrite(sb);
325 }
326
327 void nilfs_relax_pressure_in_lock(struct super_block *sb)
328 {
329 struct the_nilfs *nilfs = sb->s_fs_info;
330 struct nilfs_sc_info *sci = nilfs->ns_writer;
331
332 if (!sci || !sci->sc_flush_request)
333 return;
334
335 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
336 up_read(&nilfs->ns_segctor_sem);
337
338 down_write(&nilfs->ns_segctor_sem);
339 if (sci->sc_flush_request &&
340 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
341 struct nilfs_transaction_info *ti = current->journal_info;
342
343 ti->ti_flags |= NILFS_TI_WRITER;
344 nilfs_segctor_do_immediate_flush(sci);
345 ti->ti_flags &= ~NILFS_TI_WRITER;
346 }
347 downgrade_write(&nilfs->ns_segctor_sem);
348 }
349
350 static void nilfs_transaction_lock(struct super_block *sb,
351 struct nilfs_transaction_info *ti,
352 int gcflag)
353 {
354 struct nilfs_transaction_info *cur_ti = current->journal_info;
355 struct the_nilfs *nilfs = sb->s_fs_info;
356 struct nilfs_sc_info *sci = nilfs->ns_writer;
357
358 WARN_ON(cur_ti);
359 ti->ti_flags = NILFS_TI_WRITER;
360 ti->ti_count = 0;
361 ti->ti_save = cur_ti;
362 ti->ti_magic = NILFS_TI_MAGIC;
363 current->journal_info = ti;
364
365 for (;;) {
366 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
367 ti->ti_flags, TRACE_NILFS2_TRANSACTION_TRYLOCK);
368
369 down_write(&nilfs->ns_segctor_sem);
370 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags))
371 break;
372
373 nilfs_segctor_do_immediate_flush(sci);
374
375 up_write(&nilfs->ns_segctor_sem);
376 cond_resched();
377 }
378 if (gcflag)
379 ti->ti_flags |= NILFS_TI_GC;
380
381 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
382 ti->ti_flags, TRACE_NILFS2_TRANSACTION_LOCK);
383 }
384
385 static void nilfs_transaction_unlock(struct super_block *sb)
386 {
387 struct nilfs_transaction_info *ti = current->journal_info;
388 struct the_nilfs *nilfs = sb->s_fs_info;
389
390 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
391 BUG_ON(ti->ti_count > 0);
392
393 up_write(&nilfs->ns_segctor_sem);
394 current->journal_info = ti->ti_save;
395
396 trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
397 ti->ti_flags, TRACE_NILFS2_TRANSACTION_UNLOCK);
398 }
399
400 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
401 struct nilfs_segsum_pointer *ssp,
402 unsigned int bytes)
403 {
404 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
405 unsigned int blocksize = sci->sc_super->s_blocksize;
406 void *p;
407
408 if (unlikely(ssp->offset + bytes > blocksize)) {
409 ssp->offset = 0;
410 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
411 &segbuf->sb_segsum_buffers));
412 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
413 }
414 p = ssp->bh->b_data + ssp->offset;
415 ssp->offset += bytes;
416 return p;
417 }
418
419 /**
420 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
421 * @sci: nilfs_sc_info
422 */
423 static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
424 {
425 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
426 struct buffer_head *sumbh;
427 unsigned int sumbytes;
428 unsigned int flags = 0;
429 int err;
430
431 if (nilfs_doing_gc())
432 flags = NILFS_SS_GC;
433 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno);
434 if (unlikely(err))
435 return err;
436
437 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
438 sumbytes = segbuf->sb_sum.sumbytes;
439 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
440 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
441 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
442 return 0;
443 }
444
445 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
446 {
447 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
448 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
449 return -E2BIG; /*
450 * The current segment is filled up
451 * (internal code)
452 */
453 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
454 return nilfs_segctor_reset_segment_buffer(sci);
455 }
456
457 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
458 {
459 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
460 int err;
461
462 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
463 err = nilfs_segctor_feed_segment(sci);
464 if (err)
465 return err;
466 segbuf = sci->sc_curseg;
467 }
468 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root);
469 if (likely(!err))
470 segbuf->sb_sum.flags |= NILFS_SS_SR;
471 return err;
472 }
473
474 /*
475 * Functions for making segment summary and payloads
476 */
477 static int nilfs_segctor_segsum_block_required(
478 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
479 unsigned int binfo_size)
480 {
481 unsigned int blocksize = sci->sc_super->s_blocksize;
482 /* Size of finfo and binfo is enough small against blocksize */
483
484 return ssp->offset + binfo_size +
485 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
486 blocksize;
487 }
488
489 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
490 struct inode *inode)
491 {
492 sci->sc_curseg->sb_sum.nfinfo++;
493 sci->sc_binfo_ptr = sci->sc_finfo_ptr;
494 nilfs_segctor_map_segsum_entry(
495 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
496
497 if (NILFS_I(inode)->i_root &&
498 !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
499 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
500 /* skip finfo */
501 }
502
503 static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
504 struct inode *inode)
505 {
506 struct nilfs_finfo *finfo;
507 struct nilfs_inode_info *ii;
508 struct nilfs_segment_buffer *segbuf;
509 __u64 cno;
510
511 if (sci->sc_blk_cnt == 0)
512 return;
513
514 ii = NILFS_I(inode);
515
516 if (test_bit(NILFS_I_GCINODE, &ii->i_state))
517 cno = ii->i_cno;
518 else if (NILFS_ROOT_METADATA_FILE(inode->i_ino))
519 cno = 0;
520 else
521 cno = sci->sc_cno;
522
523 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
524 sizeof(*finfo));
525 finfo->fi_ino = cpu_to_le64(inode->i_ino);
526 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
527 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
528 finfo->fi_cno = cpu_to_le64(cno);
529
530 segbuf = sci->sc_curseg;
531 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
532 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
533 sci->sc_finfo_ptr = sci->sc_binfo_ptr;
534 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
535 }
536
537 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
538 struct buffer_head *bh,
539 struct inode *inode,
540 unsigned int binfo_size)
541 {
542 struct nilfs_segment_buffer *segbuf;
543 int required, err = 0;
544
545 retry:
546 segbuf = sci->sc_curseg;
547 required = nilfs_segctor_segsum_block_required(
548 sci, &sci->sc_binfo_ptr, binfo_size);
549 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
550 nilfs_segctor_end_finfo(sci, inode);
551 err = nilfs_segctor_feed_segment(sci);
552 if (err)
553 return err;
554 goto retry;
555 }
556 if (unlikely(required)) {
557 err = nilfs_segbuf_extend_segsum(segbuf);
558 if (unlikely(err))
559 goto failed;
560 }
561 if (sci->sc_blk_cnt == 0)
562 nilfs_segctor_begin_finfo(sci, inode);
563
564 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
565 /* Substitution to vblocknr is delayed until update_blocknr() */
566 nilfs_segbuf_add_file_buffer(segbuf, bh);
567 sci->sc_blk_cnt++;
568 failed:
569 return err;
570 }
571
572 /*
573 * Callback functions that enumerate, mark, and collect dirty blocks
574 */
575 static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
576 struct buffer_head *bh, struct inode *inode)
577 {
578 int err;
579
580 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
581 if (err < 0)
582 return err;
583
584 err = nilfs_segctor_add_file_block(sci, bh, inode,
585 sizeof(struct nilfs_binfo_v));
586 if (!err)
587 sci->sc_datablk_cnt++;
588 return err;
589 }
590
591 static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
592 struct buffer_head *bh,
593 struct inode *inode)
594 {
595 return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
596 }
597
598 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
599 struct buffer_head *bh,
600 struct inode *inode)
601 {
602 WARN_ON(!buffer_dirty(bh));
603 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
604 }
605
606 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
607 struct nilfs_segsum_pointer *ssp,
608 union nilfs_binfo *binfo)
609 {
610 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
611 sci, ssp, sizeof(*binfo_v));
612 *binfo_v = binfo->bi_v;
613 }
614
615 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
616 struct nilfs_segsum_pointer *ssp,
617 union nilfs_binfo *binfo)
618 {
619 __le64 *vblocknr = nilfs_segctor_map_segsum_entry(
620 sci, ssp, sizeof(*vblocknr));
621 *vblocknr = binfo->bi_v.bi_vblocknr;
622 }
623
624 static const struct nilfs_sc_operations nilfs_sc_file_ops = {
625 .collect_data = nilfs_collect_file_data,
626 .collect_node = nilfs_collect_file_node,
627 .collect_bmap = nilfs_collect_file_bmap,
628 .write_data_binfo = nilfs_write_file_data_binfo,
629 .write_node_binfo = nilfs_write_file_node_binfo,
630 };
631
632 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
633 struct buffer_head *bh, struct inode *inode)
634 {
635 int err;
636
637 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
638 if (err < 0)
639 return err;
640
641 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
642 if (!err)
643 sci->sc_datablk_cnt++;
644 return err;
645 }
646
647 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
648 struct buffer_head *bh, struct inode *inode)
649 {
650 WARN_ON(!buffer_dirty(bh));
651 return nilfs_segctor_add_file_block(sci, bh, inode,
652 sizeof(struct nilfs_binfo_dat));
653 }
654
655 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
656 struct nilfs_segsum_pointer *ssp,
657 union nilfs_binfo *binfo)
658 {
659 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
660 sizeof(*blkoff));
661 *blkoff = binfo->bi_dat.bi_blkoff;
662 }
663
664 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
665 struct nilfs_segsum_pointer *ssp,
666 union nilfs_binfo *binfo)
667 {
668 struct nilfs_binfo_dat *binfo_dat =
669 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
670 *binfo_dat = binfo->bi_dat;
671 }
672
673 static const struct nilfs_sc_operations nilfs_sc_dat_ops = {
674 .collect_data = nilfs_collect_dat_data,
675 .collect_node = nilfs_collect_file_node,
676 .collect_bmap = nilfs_collect_dat_bmap,
677 .write_data_binfo = nilfs_write_dat_data_binfo,
678 .write_node_binfo = nilfs_write_dat_node_binfo,
679 };
680
681 static const struct nilfs_sc_operations nilfs_sc_dsync_ops = {
682 .collect_data = nilfs_collect_file_data,
683 .collect_node = NULL,
684 .collect_bmap = NULL,
685 .write_data_binfo = nilfs_write_file_data_binfo,
686 .write_node_binfo = NULL,
687 };
688
689 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
690 struct list_head *listp,
691 size_t nlimit,
692 loff_t start, loff_t end)
693 {
694 struct address_space *mapping = inode->i_mapping;
695 struct pagevec pvec;
696 pgoff_t index = 0, last = ULONG_MAX;
697 size_t ndirties = 0;
698 int i;
699
700 if (unlikely(start != 0 || end != LLONG_MAX)) {
701 /*
702 * A valid range is given for sync-ing data pages. The
703 * range is rounded to per-page; extra dirty buffers
704 * may be included if blocksize < pagesize.
705 */
706 index = start >> PAGE_SHIFT;
707 last = end >> PAGE_SHIFT;
708 }
709 pagevec_init(&pvec, 0);
710 repeat:
711 if (unlikely(index > last) ||
712 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
713 min_t(pgoff_t, last - index,
714 PAGEVEC_SIZE - 1) + 1))
715 return ndirties;
716
717 for (i = 0; i < pagevec_count(&pvec); i++) {
718 struct buffer_head *bh, *head;
719 struct page *page = pvec.pages[i];
720
721 if (unlikely(page->index > last))
722 break;
723
724 lock_page(page);
725 if (!page_has_buffers(page))
726 create_empty_buffers(page, i_blocksize(inode), 0);
727 unlock_page(page);
728
729 bh = head = page_buffers(page);
730 do {
731 if (!buffer_dirty(bh) || buffer_async_write(bh))
732 continue;
733 get_bh(bh);
734 list_add_tail(&bh->b_assoc_buffers, listp);
735 ndirties++;
736 if (unlikely(ndirties >= nlimit)) {
737 pagevec_release(&pvec);
738 cond_resched();
739 return ndirties;
740 }
741 } while (bh = bh->b_this_page, bh != head);
742 }
743 pagevec_release(&pvec);
744 cond_resched();
745 goto repeat;
746 }
747
748 static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
749 struct list_head *listp)
750 {
751 struct nilfs_inode_info *ii = NILFS_I(inode);
752 struct address_space *mapping = &ii->i_btnode_cache;
753 struct pagevec pvec;
754 struct buffer_head *bh, *head;
755 unsigned int i;
756 pgoff_t index = 0;
757
758 pagevec_init(&pvec, 0);
759
760 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
761 PAGEVEC_SIZE)) {
762 for (i = 0; i < pagevec_count(&pvec); i++) {
763 bh = head = page_buffers(pvec.pages[i]);
764 do {
765 if (buffer_dirty(bh) &&
766 !buffer_async_write(bh)) {
767 get_bh(bh);
768 list_add_tail(&bh->b_assoc_buffers,
769 listp);
770 }
771 bh = bh->b_this_page;
772 } while (bh != head);
773 }
774 pagevec_release(&pvec);
775 cond_resched();
776 }
777 }
778
779 static void nilfs_dispose_list(struct the_nilfs *nilfs,
780 struct list_head *head, int force)
781 {
782 struct nilfs_inode_info *ii, *n;
783 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
784 unsigned int nv = 0;
785
786 while (!list_empty(head)) {
787 spin_lock(&nilfs->ns_inode_lock);
788 list_for_each_entry_safe(ii, n, head, i_dirty) {
789 list_del_init(&ii->i_dirty);
790 if (force) {
791 if (unlikely(ii->i_bh)) {
792 brelse(ii->i_bh);
793 ii->i_bh = NULL;
794 }
795 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
796 set_bit(NILFS_I_QUEUED, &ii->i_state);
797 list_add_tail(&ii->i_dirty,
798 &nilfs->ns_dirty_files);
799 continue;
800 }
801 ivec[nv++] = ii;
802 if (nv == SC_N_INODEVEC)
803 break;
804 }
805 spin_unlock(&nilfs->ns_inode_lock);
806
807 for (pii = ivec; nv > 0; pii++, nv--)
808 iput(&(*pii)->vfs_inode);
809 }
810 }
811
812 static void nilfs_iput_work_func(struct work_struct *work)
813 {
814 struct nilfs_sc_info *sci = container_of(work, struct nilfs_sc_info,
815 sc_iput_work);
816 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
817
818 nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 0);
819 }
820
821 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
822 struct nilfs_root *root)
823 {
824 int ret = 0;
825
826 if (nilfs_mdt_fetch_dirty(root->ifile))
827 ret++;
828 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
829 ret++;
830 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
831 ret++;
832 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat))
833 ret++;
834 return ret;
835 }
836
837 static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
838 {
839 return list_empty(&sci->sc_dirty_files) &&
840 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
841 sci->sc_nfreesegs == 0 &&
842 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
843 }
844
845 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
846 {
847 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
848 int ret = 0;
849
850 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
851 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
852
853 spin_lock(&nilfs->ns_inode_lock);
854 if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci))
855 ret++;
856
857 spin_unlock(&nilfs->ns_inode_lock);
858 return ret;
859 }
860
861 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
862 {
863 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
864
865 nilfs_mdt_clear_dirty(sci->sc_root->ifile);
866 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
867 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
868 nilfs_mdt_clear_dirty(nilfs->ns_dat);
869 }
870
871 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
872 {
873 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
874 struct buffer_head *bh_cp;
875 struct nilfs_checkpoint *raw_cp;
876 int err;
877
878 /* XXX: this interface will be changed */
879 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
880 &raw_cp, &bh_cp);
881 if (likely(!err)) {
882 /*
883 * The following code is duplicated with cpfile. But, it is
884 * needed to collect the checkpoint even if it was not newly
885 * created.
886 */
887 mark_buffer_dirty(bh_cp);
888 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
889 nilfs_cpfile_put_checkpoint(
890 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
891 } else
892 WARN_ON(err == -EINVAL || err == -ENOENT);
893
894 return err;
895 }
896
897 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
898 {
899 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
900 struct buffer_head *bh_cp;
901 struct nilfs_checkpoint *raw_cp;
902 int err;
903
904 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
905 &raw_cp, &bh_cp);
906 if (unlikely(err)) {
907 WARN_ON(err == -EINVAL || err == -ENOENT);
908 goto failed_ibh;
909 }
910 raw_cp->cp_snapshot_list.ssl_next = 0;
911 raw_cp->cp_snapshot_list.ssl_prev = 0;
912 raw_cp->cp_inodes_count =
913 cpu_to_le64(atomic64_read(&sci->sc_root->inodes_count));
914 raw_cp->cp_blocks_count =
915 cpu_to_le64(atomic64_read(&sci->sc_root->blocks_count));
916 raw_cp->cp_nblk_inc =
917 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
918 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
919 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
920
921 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
922 nilfs_checkpoint_clear_minor(raw_cp);
923 else
924 nilfs_checkpoint_set_minor(raw_cp);
925
926 nilfs_write_inode_common(sci->sc_root->ifile,
927 &raw_cp->cp_ifile_inode, 1);
928 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
929 return 0;
930
931 failed_ibh:
932 return err;
933 }
934
935 static void nilfs_fill_in_file_bmap(struct inode *ifile,
936 struct nilfs_inode_info *ii)
937
938 {
939 struct buffer_head *ibh;
940 struct nilfs_inode *raw_inode;
941
942 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
943 ibh = ii->i_bh;
944 BUG_ON(!ibh);
945 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
946 ibh);
947 nilfs_bmap_write(ii->i_bmap, raw_inode);
948 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
949 }
950 }
951
952 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
953 {
954 struct nilfs_inode_info *ii;
955
956 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
957 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
958 set_bit(NILFS_I_COLLECTED, &ii->i_state);
959 }
960 }
961
962 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
963 struct the_nilfs *nilfs)
964 {
965 struct buffer_head *bh_sr;
966 struct nilfs_super_root *raw_sr;
967 unsigned int isz, srsz;
968
969 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
970 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
971 isz = nilfs->ns_inode_size;
972 srsz = NILFS_SR_BYTES(isz);
973
974 raw_sr->sr_bytes = cpu_to_le16(srsz);
975 raw_sr->sr_nongc_ctime
976 = cpu_to_le64(nilfs_doing_gc() ?
977 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
978 raw_sr->sr_flags = 0;
979
980 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr +
981 NILFS_SR_DAT_OFFSET(isz), 1);
982 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
983 NILFS_SR_CPFILE_OFFSET(isz), 1);
984 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
985 NILFS_SR_SUFILE_OFFSET(isz), 1);
986 memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz);
987 }
988
989 static void nilfs_redirty_inodes(struct list_head *head)
990 {
991 struct nilfs_inode_info *ii;
992
993 list_for_each_entry(ii, head, i_dirty) {
994 if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
995 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
996 }
997 }
998
999 static void nilfs_drop_collected_inodes(struct list_head *head)
1000 {
1001 struct nilfs_inode_info *ii;
1002
1003 list_for_each_entry(ii, head, i_dirty) {
1004 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
1005 continue;
1006
1007 clear_bit(NILFS_I_INODE_SYNC, &ii->i_state);
1008 set_bit(NILFS_I_UPDATED, &ii->i_state);
1009 }
1010 }
1011
1012 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
1013 struct inode *inode,
1014 struct list_head *listp,
1015 int (*collect)(struct nilfs_sc_info *,
1016 struct buffer_head *,
1017 struct inode *))
1018 {
1019 struct buffer_head *bh, *n;
1020 int err = 0;
1021
1022 if (collect) {
1023 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
1024 list_del_init(&bh->b_assoc_buffers);
1025 err = collect(sci, bh, inode);
1026 brelse(bh);
1027 if (unlikely(err))
1028 goto dispose_buffers;
1029 }
1030 return 0;
1031 }
1032
1033 dispose_buffers:
1034 while (!list_empty(listp)) {
1035 bh = list_first_entry(listp, struct buffer_head,
1036 b_assoc_buffers);
1037 list_del_init(&bh->b_assoc_buffers);
1038 brelse(bh);
1039 }
1040 return err;
1041 }
1042
1043 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
1044 {
1045 /* Remaining number of blocks within segment buffer */
1046 return sci->sc_segbuf_nblocks -
1047 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
1048 }
1049
1050 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
1051 struct inode *inode,
1052 const struct nilfs_sc_operations *sc_ops)
1053 {
1054 LIST_HEAD(data_buffers);
1055 LIST_HEAD(node_buffers);
1056 int err;
1057
1058 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1059 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1060
1061 n = nilfs_lookup_dirty_data_buffers(
1062 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
1063 if (n > rest) {
1064 err = nilfs_segctor_apply_buffers(
1065 sci, inode, &data_buffers,
1066 sc_ops->collect_data);
1067 BUG_ON(!err); /* always receive -E2BIG or true error */
1068 goto break_or_fail;
1069 }
1070 }
1071 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
1072
1073 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1074 err = nilfs_segctor_apply_buffers(
1075 sci, inode, &data_buffers, sc_ops->collect_data);
1076 if (unlikely(err)) {
1077 /* dispose node list */
1078 nilfs_segctor_apply_buffers(
1079 sci, inode, &node_buffers, NULL);
1080 goto break_or_fail;
1081 }
1082 sci->sc_stage.flags |= NILFS_CF_NODE;
1083 }
1084 /* Collect node */
1085 err = nilfs_segctor_apply_buffers(
1086 sci, inode, &node_buffers, sc_ops->collect_node);
1087 if (unlikely(err))
1088 goto break_or_fail;
1089
1090 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1091 err = nilfs_segctor_apply_buffers(
1092 sci, inode, &node_buffers, sc_ops->collect_bmap);
1093 if (unlikely(err))
1094 goto break_or_fail;
1095
1096 nilfs_segctor_end_finfo(sci, inode);
1097 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1098
1099 break_or_fail:
1100 return err;
1101 }
1102
1103 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1104 struct inode *inode)
1105 {
1106 LIST_HEAD(data_buffers);
1107 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1108 int err;
1109
1110 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1111 sci->sc_dsync_start,
1112 sci->sc_dsync_end);
1113
1114 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1115 nilfs_collect_file_data);
1116 if (!err) {
1117 nilfs_segctor_end_finfo(sci, inode);
1118 BUG_ON(n > rest);
1119 /* always receive -E2BIG or true error if n > rest */
1120 }
1121 return err;
1122 }
1123
1124 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1125 {
1126 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1127 struct list_head *head;
1128 struct nilfs_inode_info *ii;
1129 size_t ndone;
1130 int err = 0;
1131
1132 switch (nilfs_sc_cstage_get(sci)) {
1133 case NILFS_ST_INIT:
1134 /* Pre-processes */
1135 sci->sc_stage.flags = 0;
1136
1137 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1138 sci->sc_nblk_inc = 0;
1139 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1140 if (mode == SC_LSEG_DSYNC) {
1141 nilfs_sc_cstage_set(sci, NILFS_ST_DSYNC);
1142 goto dsync_mode;
1143 }
1144 }
1145
1146 sci->sc_stage.dirty_file_ptr = NULL;
1147 sci->sc_stage.gc_inode_ptr = NULL;
1148 if (mode == SC_FLUSH_DAT) {
1149 nilfs_sc_cstage_set(sci, NILFS_ST_DAT);
1150 goto dat_stage;
1151 }
1152 nilfs_sc_cstage_inc(sci); /* Fall through */
1153 case NILFS_ST_GC:
1154 if (nilfs_doing_gc()) {
1155 head = &sci->sc_gc_inodes;
1156 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1157 head, i_dirty);
1158 list_for_each_entry_continue(ii, head, i_dirty) {
1159 err = nilfs_segctor_scan_file(
1160 sci, &ii->vfs_inode,
1161 &nilfs_sc_file_ops);
1162 if (unlikely(err)) {
1163 sci->sc_stage.gc_inode_ptr = list_entry(
1164 ii->i_dirty.prev,
1165 struct nilfs_inode_info,
1166 i_dirty);
1167 goto break_or_fail;
1168 }
1169 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1170 }
1171 sci->sc_stage.gc_inode_ptr = NULL;
1172 }
1173 nilfs_sc_cstage_inc(sci); /* Fall through */
1174 case NILFS_ST_FILE:
1175 head = &sci->sc_dirty_files;
1176 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1177 i_dirty);
1178 list_for_each_entry_continue(ii, head, i_dirty) {
1179 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1180
1181 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1182 &nilfs_sc_file_ops);
1183 if (unlikely(err)) {
1184 sci->sc_stage.dirty_file_ptr =
1185 list_entry(ii->i_dirty.prev,
1186 struct nilfs_inode_info,
1187 i_dirty);
1188 goto break_or_fail;
1189 }
1190 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1191 /* XXX: required ? */
1192 }
1193 sci->sc_stage.dirty_file_ptr = NULL;
1194 if (mode == SC_FLUSH_FILE) {
1195 nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1196 return 0;
1197 }
1198 nilfs_sc_cstage_inc(sci);
1199 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1200 /* Fall through */
1201 case NILFS_ST_IFILE:
1202 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile,
1203 &nilfs_sc_file_ops);
1204 if (unlikely(err))
1205 break;
1206 nilfs_sc_cstage_inc(sci);
1207 /* Creating a checkpoint */
1208 err = nilfs_segctor_create_checkpoint(sci);
1209 if (unlikely(err))
1210 break;
1211 /* Fall through */
1212 case NILFS_ST_CPFILE:
1213 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1214 &nilfs_sc_file_ops);
1215 if (unlikely(err))
1216 break;
1217 nilfs_sc_cstage_inc(sci); /* Fall through */
1218 case NILFS_ST_SUFILE:
1219 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1220 sci->sc_nfreesegs, &ndone);
1221 if (unlikely(err)) {
1222 nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1223 sci->sc_freesegs, ndone,
1224 NULL);
1225 break;
1226 }
1227 sci->sc_stage.flags |= NILFS_CF_SUFREED;
1228
1229 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1230 &nilfs_sc_file_ops);
1231 if (unlikely(err))
1232 break;
1233 nilfs_sc_cstage_inc(sci); /* Fall through */
1234 case NILFS_ST_DAT:
1235 dat_stage:
1236 err = nilfs_segctor_scan_file(sci, nilfs->ns_dat,
1237 &nilfs_sc_dat_ops);
1238 if (unlikely(err))
1239 break;
1240 if (mode == SC_FLUSH_DAT) {
1241 nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1242 return 0;
1243 }
1244 nilfs_sc_cstage_inc(sci); /* Fall through */
1245 case NILFS_ST_SR:
1246 if (mode == SC_LSEG_SR) {
1247 /* Appending a super root */
1248 err = nilfs_segctor_add_super_root(sci);
1249 if (unlikely(err))
1250 break;
1251 }
1252 /* End of a logical segment */
1253 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1254 nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1255 return 0;
1256 case NILFS_ST_DSYNC:
1257 dsync_mode:
1258 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1259 ii = sci->sc_dsync_inode;
1260 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1261 break;
1262
1263 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1264 if (unlikely(err))
1265 break;
1266 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1267 nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1268 return 0;
1269 case NILFS_ST_DONE:
1270 return 0;
1271 default:
1272 BUG();
1273 }
1274
1275 break_or_fail:
1276 return err;
1277 }
1278
1279 /**
1280 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1281 * @sci: nilfs_sc_info
1282 * @nilfs: nilfs object
1283 */
1284 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1285 struct the_nilfs *nilfs)
1286 {
1287 struct nilfs_segment_buffer *segbuf, *prev;
1288 __u64 nextnum;
1289 int err, alloc = 0;
1290
1291 segbuf = nilfs_segbuf_new(sci->sc_super);
1292 if (unlikely(!segbuf))
1293 return -ENOMEM;
1294
1295 if (list_empty(&sci->sc_write_logs)) {
1296 nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1297 nilfs->ns_pseg_offset, nilfs);
1298 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1299 nilfs_shift_to_next_segment(nilfs);
1300 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1301 }
1302
1303 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1304 nextnum = nilfs->ns_nextnum;
1305
1306 if (nilfs->ns_segnum == nilfs->ns_nextnum)
1307 /* Start from the head of a new full segment */
1308 alloc++;
1309 } else {
1310 /* Continue logs */
1311 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1312 nilfs_segbuf_map_cont(segbuf, prev);
1313 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1314 nextnum = prev->sb_nextnum;
1315
1316 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1317 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1318 segbuf->sb_sum.seg_seq++;
1319 alloc++;
1320 }
1321 }
1322
1323 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1324 if (err)
1325 goto failed;
1326
1327 if (alloc) {
1328 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1329 if (err)
1330 goto failed;
1331 }
1332 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1333
1334 BUG_ON(!list_empty(&sci->sc_segbufs));
1335 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1336 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1337 return 0;
1338
1339 failed:
1340 nilfs_segbuf_free(segbuf);
1341 return err;
1342 }
1343
1344 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1345 struct the_nilfs *nilfs, int nadd)
1346 {
1347 struct nilfs_segment_buffer *segbuf, *prev;
1348 struct inode *sufile = nilfs->ns_sufile;
1349 __u64 nextnextnum;
1350 LIST_HEAD(list);
1351 int err, ret, i;
1352
1353 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1354 /*
1355 * Since the segment specified with nextnum might be allocated during
1356 * the previous construction, the buffer including its segusage may
1357 * not be dirty. The following call ensures that the buffer is dirty
1358 * and will pin the buffer on memory until the sufile is written.
1359 */
1360 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1361 if (unlikely(err))
1362 return err;
1363
1364 for (i = 0; i < nadd; i++) {
1365 /* extend segment info */
1366 err = -ENOMEM;
1367 segbuf = nilfs_segbuf_new(sci->sc_super);
1368 if (unlikely(!segbuf))
1369 goto failed;
1370
1371 /* map this buffer to region of segment on-disk */
1372 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1373 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1374
1375 /* allocate the next next full segment */
1376 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1377 if (unlikely(err))
1378 goto failed_segbuf;
1379
1380 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1381 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1382
1383 list_add_tail(&segbuf->sb_list, &list);
1384 prev = segbuf;
1385 }
1386 list_splice_tail(&list, &sci->sc_segbufs);
1387 return 0;
1388
1389 failed_segbuf:
1390 nilfs_segbuf_free(segbuf);
1391 failed:
1392 list_for_each_entry(segbuf, &list, sb_list) {
1393 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1394 WARN_ON(ret); /* never fails */
1395 }
1396 nilfs_destroy_logs(&list);
1397 return err;
1398 }
1399
1400 static void nilfs_free_incomplete_logs(struct list_head *logs,
1401 struct the_nilfs *nilfs)
1402 {
1403 struct nilfs_segment_buffer *segbuf, *prev;
1404 struct inode *sufile = nilfs->ns_sufile;
1405 int ret;
1406
1407 segbuf = NILFS_FIRST_SEGBUF(logs);
1408 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1409 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1410 WARN_ON(ret); /* never fails */
1411 }
1412 if (atomic_read(&segbuf->sb_err)) {
1413 /* Case 1: The first segment failed */
1414 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1415 /*
1416 * Case 1a: Partial segment appended into an existing
1417 * segment
1418 */
1419 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1420 segbuf->sb_fseg_end);
1421 else /* Case 1b: New full segment */
1422 set_nilfs_discontinued(nilfs);
1423 }
1424
1425 prev = segbuf;
1426 list_for_each_entry_continue(segbuf, logs, sb_list) {
1427 if (prev->sb_nextnum != segbuf->sb_nextnum) {
1428 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1429 WARN_ON(ret); /* never fails */
1430 }
1431 if (atomic_read(&segbuf->sb_err) &&
1432 segbuf->sb_segnum != nilfs->ns_nextnum)
1433 /* Case 2: extended segment (!= next) failed */
1434 nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1435 prev = segbuf;
1436 }
1437 }
1438
1439 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1440 struct inode *sufile)
1441 {
1442 struct nilfs_segment_buffer *segbuf;
1443 unsigned long live_blocks;
1444 int ret;
1445
1446 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1447 live_blocks = segbuf->sb_sum.nblocks +
1448 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1449 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1450 live_blocks,
1451 sci->sc_seg_ctime);
1452 WARN_ON(ret); /* always succeed because the segusage is dirty */
1453 }
1454 }
1455
1456 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1457 {
1458 struct nilfs_segment_buffer *segbuf;
1459 int ret;
1460
1461 segbuf = NILFS_FIRST_SEGBUF(logs);
1462 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1463 segbuf->sb_pseg_start -
1464 segbuf->sb_fseg_start, 0);
1465 WARN_ON(ret); /* always succeed because the segusage is dirty */
1466
1467 list_for_each_entry_continue(segbuf, logs, sb_list) {
1468 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1469 0, 0);
1470 WARN_ON(ret); /* always succeed */
1471 }
1472 }
1473
1474 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1475 struct nilfs_segment_buffer *last,
1476 struct inode *sufile)
1477 {
1478 struct nilfs_segment_buffer *segbuf = last;
1479 int ret;
1480
1481 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1482 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1483 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1484 WARN_ON(ret);
1485 }
1486 nilfs_truncate_logs(&sci->sc_segbufs, last);
1487 }
1488
1489
1490 static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1491 struct the_nilfs *nilfs, int mode)
1492 {
1493 struct nilfs_cstage prev_stage = sci->sc_stage;
1494 int err, nadd = 1;
1495
1496 /* Collection retry loop */
1497 for (;;) {
1498 sci->sc_nblk_this_inc = 0;
1499 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1500
1501 err = nilfs_segctor_reset_segment_buffer(sci);
1502 if (unlikely(err))
1503 goto failed;
1504
1505 err = nilfs_segctor_collect_blocks(sci, mode);
1506 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1507 if (!err)
1508 break;
1509
1510 if (unlikely(err != -E2BIG))
1511 goto failed;
1512
1513 /* The current segment is filled up */
1514 if (mode != SC_LSEG_SR ||
1515 nilfs_sc_cstage_get(sci) < NILFS_ST_CPFILE)
1516 break;
1517
1518 nilfs_clear_logs(&sci->sc_segbufs);
1519
1520 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1521 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1522 sci->sc_freesegs,
1523 sci->sc_nfreesegs,
1524 NULL);
1525 WARN_ON(err); /* do not happen */
1526 sci->sc_stage.flags &= ~NILFS_CF_SUFREED;
1527 }
1528
1529 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1530 if (unlikely(err))
1531 return err;
1532
1533 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1534 sci->sc_stage = prev_stage;
1535 }
1536 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1537 return 0;
1538
1539 failed:
1540 return err;
1541 }
1542
1543 static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1544 struct buffer_head *new_bh)
1545 {
1546 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1547
1548 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1549 /* The caller must release old_bh */
1550 }
1551
1552 static int
1553 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1554 struct nilfs_segment_buffer *segbuf,
1555 int mode)
1556 {
1557 struct inode *inode = NULL;
1558 sector_t blocknr;
1559 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1560 unsigned long nblocks = 0, ndatablk = 0;
1561 const struct nilfs_sc_operations *sc_op = NULL;
1562 struct nilfs_segsum_pointer ssp;
1563 struct nilfs_finfo *finfo = NULL;
1564 union nilfs_binfo binfo;
1565 struct buffer_head *bh, *bh_org;
1566 ino_t ino = 0;
1567 int err = 0;
1568
1569 if (!nfinfo)
1570 goto out;
1571
1572 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1573 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1574 ssp.offset = sizeof(struct nilfs_segment_summary);
1575
1576 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1577 if (bh == segbuf->sb_super_root)
1578 break;
1579 if (!finfo) {
1580 finfo = nilfs_segctor_map_segsum_entry(
1581 sci, &ssp, sizeof(*finfo));
1582 ino = le64_to_cpu(finfo->fi_ino);
1583 nblocks = le32_to_cpu(finfo->fi_nblocks);
1584 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1585
1586 inode = bh->b_page->mapping->host;
1587
1588 if (mode == SC_LSEG_DSYNC)
1589 sc_op = &nilfs_sc_dsync_ops;
1590 else if (ino == NILFS_DAT_INO)
1591 sc_op = &nilfs_sc_dat_ops;
1592 else /* file blocks */
1593 sc_op = &nilfs_sc_file_ops;
1594 }
1595 bh_org = bh;
1596 get_bh(bh_org);
1597 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1598 &binfo);
1599 if (bh != bh_org)
1600 nilfs_list_replace_buffer(bh_org, bh);
1601 brelse(bh_org);
1602 if (unlikely(err))
1603 goto failed_bmap;
1604
1605 if (ndatablk > 0)
1606 sc_op->write_data_binfo(sci, &ssp, &binfo);
1607 else
1608 sc_op->write_node_binfo(sci, &ssp, &binfo);
1609
1610 blocknr++;
1611 if (--nblocks == 0) {
1612 finfo = NULL;
1613 if (--nfinfo == 0)
1614 break;
1615 } else if (ndatablk > 0)
1616 ndatablk--;
1617 }
1618 out:
1619 return 0;
1620
1621 failed_bmap:
1622 return err;
1623 }
1624
1625 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1626 {
1627 struct nilfs_segment_buffer *segbuf;
1628 int err;
1629
1630 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1631 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1632 if (unlikely(err))
1633 return err;
1634 nilfs_segbuf_fill_in_segsum(segbuf);
1635 }
1636 return 0;
1637 }
1638
1639 static void nilfs_begin_page_io(struct page *page)
1640 {
1641 if (!page || PageWriteback(page))
1642 /*
1643 * For split b-tree node pages, this function may be called
1644 * twice. We ignore the 2nd or later calls by this check.
1645 */
1646 return;
1647
1648 lock_page(page);
1649 clear_page_dirty_for_io(page);
1650 set_page_writeback(page);
1651 unlock_page(page);
1652 }
1653
1654 static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
1655 {
1656 struct nilfs_segment_buffer *segbuf;
1657 struct page *bd_page = NULL, *fs_page = NULL;
1658
1659 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1660 struct buffer_head *bh;
1661
1662 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1663 b_assoc_buffers) {
1664 if (bh->b_page != bd_page) {
1665 if (bd_page) {
1666 lock_page(bd_page);
1667 clear_page_dirty_for_io(bd_page);
1668 set_page_writeback(bd_page);
1669 unlock_page(bd_page);
1670 }
1671 bd_page = bh->b_page;
1672 }
1673 }
1674
1675 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1676 b_assoc_buffers) {
1677 set_buffer_async_write(bh);
1678 if (bh == segbuf->sb_super_root) {
1679 if (bh->b_page != bd_page) {
1680 lock_page(bd_page);
1681 clear_page_dirty_for_io(bd_page);
1682 set_page_writeback(bd_page);
1683 unlock_page(bd_page);
1684 bd_page = bh->b_page;
1685 }
1686 break;
1687 }
1688 if (bh->b_page != fs_page) {
1689 nilfs_begin_page_io(fs_page);
1690 fs_page = bh->b_page;
1691 }
1692 }
1693 }
1694 if (bd_page) {
1695 lock_page(bd_page);
1696 clear_page_dirty_for_io(bd_page);
1697 set_page_writeback(bd_page);
1698 unlock_page(bd_page);
1699 }
1700 nilfs_begin_page_io(fs_page);
1701 }
1702
1703 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1704 struct the_nilfs *nilfs)
1705 {
1706 int ret;
1707
1708 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1709 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1710 return ret;
1711 }
1712
1713 static void nilfs_end_page_io(struct page *page, int err)
1714 {
1715 if (!page)
1716 return;
1717
1718 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
1719 /*
1720 * For b-tree node pages, this function may be called twice
1721 * or more because they might be split in a segment.
1722 */
1723 if (PageDirty(page)) {
1724 /*
1725 * For pages holding split b-tree node buffers, dirty
1726 * flag on the buffers may be cleared discretely.
1727 * In that case, the page is once redirtied for
1728 * remaining buffers, and it must be cancelled if
1729 * all the buffers get cleaned later.
1730 */
1731 lock_page(page);
1732 if (nilfs_page_buffers_clean(page))
1733 __nilfs_clear_page_dirty(page);
1734 unlock_page(page);
1735 }
1736 return;
1737 }
1738
1739 if (!err) {
1740 if (!nilfs_page_buffers_clean(page))
1741 __set_page_dirty_nobuffers(page);
1742 ClearPageError(page);
1743 } else {
1744 __set_page_dirty_nobuffers(page);
1745 SetPageError(page);
1746 }
1747
1748 end_page_writeback(page);
1749 }
1750
1751 static void nilfs_abort_logs(struct list_head *logs, int err)
1752 {
1753 struct nilfs_segment_buffer *segbuf;
1754 struct page *bd_page = NULL, *fs_page = NULL;
1755 struct buffer_head *bh;
1756
1757 if (list_empty(logs))
1758 return;
1759
1760 list_for_each_entry(segbuf, logs, sb_list) {
1761 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1762 b_assoc_buffers) {
1763 if (bh->b_page != bd_page) {
1764 if (bd_page)
1765 end_page_writeback(bd_page);
1766 bd_page = bh->b_page;
1767 }
1768 }
1769
1770 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1771 b_assoc_buffers) {
1772 clear_buffer_async_write(bh);
1773 if (bh == segbuf->sb_super_root) {
1774 if (bh->b_page != bd_page) {
1775 end_page_writeback(bd_page);
1776 bd_page = bh->b_page;
1777 }
1778 break;
1779 }
1780 if (bh->b_page != fs_page) {
1781 nilfs_end_page_io(fs_page, err);
1782 fs_page = bh->b_page;
1783 }
1784 }
1785 }
1786 if (bd_page)
1787 end_page_writeback(bd_page);
1788
1789 nilfs_end_page_io(fs_page, err);
1790 }
1791
1792 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1793 struct the_nilfs *nilfs, int err)
1794 {
1795 LIST_HEAD(logs);
1796 int ret;
1797
1798 list_splice_tail_init(&sci->sc_write_logs, &logs);
1799 ret = nilfs_wait_on_logs(&logs);
1800 nilfs_abort_logs(&logs, ret ? : err);
1801
1802 list_splice_tail_init(&sci->sc_segbufs, &logs);
1803 nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1804 nilfs_free_incomplete_logs(&logs, nilfs);
1805
1806 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1807 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1808 sci->sc_freesegs,
1809 sci->sc_nfreesegs,
1810 NULL);
1811 WARN_ON(ret); /* do not happen */
1812 }
1813
1814 nilfs_destroy_logs(&logs);
1815 }
1816
1817 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1818 struct nilfs_segment_buffer *segbuf)
1819 {
1820 nilfs->ns_segnum = segbuf->sb_segnum;
1821 nilfs->ns_nextnum = segbuf->sb_nextnum;
1822 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1823 + segbuf->sb_sum.nblocks;
1824 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1825 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1826 }
1827
1828 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1829 {
1830 struct nilfs_segment_buffer *segbuf;
1831 struct page *bd_page = NULL, *fs_page = NULL;
1832 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1833 int update_sr = false;
1834
1835 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1836 struct buffer_head *bh;
1837
1838 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1839 b_assoc_buffers) {
1840 set_buffer_uptodate(bh);
1841 clear_buffer_dirty(bh);
1842 if (bh->b_page != bd_page) {
1843 if (bd_page)
1844 end_page_writeback(bd_page);
1845 bd_page = bh->b_page;
1846 }
1847 }
1848 /*
1849 * We assume that the buffers which belong to the same page
1850 * continue over the buffer list.
1851 * Under this assumption, the last BHs of pages is
1852 * identifiable by the discontinuity of bh->b_page
1853 * (page != fs_page).
1854 *
1855 * For B-tree node blocks, however, this assumption is not
1856 * guaranteed. The cleanup code of B-tree node pages needs
1857 * special care.
1858 */
1859 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1860 b_assoc_buffers) {
1861 const unsigned long set_bits = BIT(BH_Uptodate);
1862 const unsigned long clear_bits =
1863 (BIT(BH_Dirty) | BIT(BH_Async_Write) |
1864 BIT(BH_Delay) | BIT(BH_NILFS_Volatile) |
1865 BIT(BH_NILFS_Redirected));
1866
1867 set_mask_bits(&bh->b_state, clear_bits, set_bits);
1868 if (bh == segbuf->sb_super_root) {
1869 if (bh->b_page != bd_page) {
1870 end_page_writeback(bd_page);
1871 bd_page = bh->b_page;
1872 }
1873 update_sr = true;
1874 break;
1875 }
1876 if (bh->b_page != fs_page) {
1877 nilfs_end_page_io(fs_page, 0);
1878 fs_page = bh->b_page;
1879 }
1880 }
1881
1882 if (!nilfs_segbuf_simplex(segbuf)) {
1883 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
1884 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1885 sci->sc_lseg_stime = jiffies;
1886 }
1887 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
1888 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1889 }
1890 }
1891 /*
1892 * Since pages may continue over multiple segment buffers,
1893 * end of the last page must be checked outside of the loop.
1894 */
1895 if (bd_page)
1896 end_page_writeback(bd_page);
1897
1898 nilfs_end_page_io(fs_page, 0);
1899
1900 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1901
1902 if (nilfs_doing_gc())
1903 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1904 else
1905 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1906
1907 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1908
1909 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1910 nilfs_set_next_segment(nilfs, segbuf);
1911
1912 if (update_sr) {
1913 nilfs->ns_flushed_device = 0;
1914 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
1915 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
1916
1917 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
1918 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1919 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1920 nilfs_segctor_clear_metadata_dirty(sci);
1921 } else
1922 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1923 }
1924
1925 static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
1926 {
1927 int ret;
1928
1929 ret = nilfs_wait_on_logs(&sci->sc_write_logs);
1930 if (!ret) {
1931 nilfs_segctor_complete_write(sci);
1932 nilfs_destroy_logs(&sci->sc_write_logs);
1933 }
1934 return ret;
1935 }
1936
1937 static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci,
1938 struct the_nilfs *nilfs)
1939 {
1940 struct nilfs_inode_info *ii, *n;
1941 struct inode *ifile = sci->sc_root->ifile;
1942
1943 spin_lock(&nilfs->ns_inode_lock);
1944 retry:
1945 list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) {
1946 if (!ii->i_bh) {
1947 struct buffer_head *ibh;
1948 int err;
1949
1950 spin_unlock(&nilfs->ns_inode_lock);
1951 err = nilfs_ifile_get_inode_block(
1952 ifile, ii->vfs_inode.i_ino, &ibh);
1953 if (unlikely(err)) {
1954 nilfs_msg(sci->sc_super, KERN_WARNING,
1955 "log writer: error %d getting inode block (ino=%lu)",
1956 err, ii->vfs_inode.i_ino);
1957 return err;
1958 }
1959 spin_lock(&nilfs->ns_inode_lock);
1960 if (likely(!ii->i_bh))
1961 ii->i_bh = ibh;
1962 else
1963 brelse(ibh);
1964 goto retry;
1965 }
1966
1967 // Always redirty the buffer to avoid race condition
1968 mark_buffer_dirty(ii->i_bh);
1969 nilfs_mdt_mark_dirty(ifile);
1970
1971 clear_bit(NILFS_I_QUEUED, &ii->i_state);
1972 set_bit(NILFS_I_BUSY, &ii->i_state);
1973 list_move_tail(&ii->i_dirty, &sci->sc_dirty_files);
1974 }
1975 spin_unlock(&nilfs->ns_inode_lock);
1976
1977 return 0;
1978 }
1979
1980 static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
1981 struct the_nilfs *nilfs)
1982 {
1983 struct nilfs_inode_info *ii, *n;
1984 int during_mount = !(sci->sc_super->s_flags & MS_ACTIVE);
1985 int defer_iput = false;
1986
1987 spin_lock(&nilfs->ns_inode_lock);
1988 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
1989 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
1990 test_bit(NILFS_I_DIRTY, &ii->i_state))
1991 continue;
1992
1993 clear_bit(NILFS_I_BUSY, &ii->i_state);
1994 brelse(ii->i_bh);
1995 ii->i_bh = NULL;
1996 list_del_init(&ii->i_dirty);
1997 if (!ii->vfs_inode.i_nlink || during_mount) {
1998 /*
1999 * Defer calling iput() to avoid deadlocks if
2000 * i_nlink == 0 or mount is not yet finished.
2001 */
2002 list_add_tail(&ii->i_dirty, &sci->sc_iput_queue);
2003 defer_iput = true;
2004 } else {
2005 spin_unlock(&nilfs->ns_inode_lock);
2006 iput(&ii->vfs_inode);
2007 spin_lock(&nilfs->ns_inode_lock);
2008 }
2009 }
2010 spin_unlock(&nilfs->ns_inode_lock);
2011
2012 if (defer_iput)
2013 schedule_work(&sci->sc_iput_work);
2014 }
2015
2016 /*
2017 * Main procedure of segment constructor
2018 */
2019 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2020 {
2021 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2022 int err;
2023
2024 nilfs_sc_cstage_set(sci, NILFS_ST_INIT);
2025 sci->sc_cno = nilfs->ns_cno;
2026
2027 err = nilfs_segctor_collect_dirty_files(sci, nilfs);
2028 if (unlikely(err))
2029 goto out;
2030
2031 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
2032 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2033
2034 if (nilfs_segctor_clean(sci))
2035 goto out;
2036
2037 do {
2038 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2039
2040 err = nilfs_segctor_begin_construction(sci, nilfs);
2041 if (unlikely(err))
2042 goto out;
2043
2044 /* Update time stamp */
2045 sci->sc_seg_ctime = get_seconds();
2046
2047 err = nilfs_segctor_collect(sci, nilfs, mode);
2048 if (unlikely(err))
2049 goto failed;
2050
2051 /* Avoid empty segment */
2052 if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE &&
2053 nilfs_segbuf_empty(sci->sc_curseg)) {
2054 nilfs_segctor_abort_construction(sci, nilfs, 1);
2055 goto out;
2056 }
2057
2058 err = nilfs_segctor_assign(sci, mode);
2059 if (unlikely(err))
2060 goto failed;
2061
2062 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2063 nilfs_segctor_fill_in_file_bmap(sci);
2064
2065 if (mode == SC_LSEG_SR &&
2066 nilfs_sc_cstage_get(sci) >= NILFS_ST_CPFILE) {
2067 err = nilfs_segctor_fill_in_checkpoint(sci);
2068 if (unlikely(err))
2069 goto failed_to_write;
2070
2071 nilfs_segctor_fill_in_super_root(sci, nilfs);
2072 }
2073 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2074
2075 /* Write partial segments */
2076 nilfs_segctor_prepare_write(sci);
2077
2078 nilfs_add_checksums_on_logs(&sci->sc_segbufs,
2079 nilfs->ns_crc_seed);
2080
2081 err = nilfs_segctor_write(sci, nilfs);
2082 if (unlikely(err))
2083 goto failed_to_write;
2084
2085 if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE ||
2086 nilfs->ns_blocksize_bits != PAGE_SHIFT) {
2087 /*
2088 * At this point, we avoid double buffering
2089 * for blocksize < pagesize because page dirty
2090 * flag is turned off during write and dirty
2091 * buffers are not properly collected for
2092 * pages crossing over segments.
2093 */
2094 err = nilfs_segctor_wait(sci);
2095 if (err)
2096 goto failed_to_write;
2097 }
2098 } while (nilfs_sc_cstage_get(sci) != NILFS_ST_DONE);
2099
2100 out:
2101 nilfs_segctor_drop_written_files(sci, nilfs);
2102 return err;
2103
2104 failed_to_write:
2105 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2106 nilfs_redirty_inodes(&sci->sc_dirty_files);
2107
2108 failed:
2109 if (nilfs_doing_gc())
2110 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2111 nilfs_segctor_abort_construction(sci, nilfs, err);
2112 goto out;
2113 }
2114
2115 /**
2116 * nilfs_segctor_start_timer - set timer of background write
2117 * @sci: nilfs_sc_info
2118 *
2119 * If the timer has already been set, it ignores the new request.
2120 * This function MUST be called within a section locking the segment
2121 * semaphore.
2122 */
2123 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2124 {
2125 spin_lock(&sci->sc_state_lock);
2126 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2127 sci->sc_timer.expires = jiffies + sci->sc_interval;
2128 add_timer(&sci->sc_timer);
2129 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2130 }
2131 spin_unlock(&sci->sc_state_lock);
2132 }
2133
2134 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2135 {
2136 spin_lock(&sci->sc_state_lock);
2137 if (!(sci->sc_flush_request & BIT(bn))) {
2138 unsigned long prev_req = sci->sc_flush_request;
2139
2140 sci->sc_flush_request |= BIT(bn);
2141 if (!prev_req)
2142 wake_up(&sci->sc_wait_daemon);
2143 }
2144 spin_unlock(&sci->sc_state_lock);
2145 }
2146
2147 /**
2148 * nilfs_flush_segment - trigger a segment construction for resource control
2149 * @sb: super block
2150 * @ino: inode number of the file to be flushed out.
2151 */
2152 void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2153 {
2154 struct the_nilfs *nilfs = sb->s_fs_info;
2155 struct nilfs_sc_info *sci = nilfs->ns_writer;
2156
2157 if (!sci || nilfs_doing_construction())
2158 return;
2159 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2160 /* assign bit 0 to data files */
2161 }
2162
2163 struct nilfs_segctor_wait_request {
2164 wait_queue_t wq;
2165 __u32 seq;
2166 int err;
2167 atomic_t done;
2168 };
2169
2170 static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2171 {
2172 struct nilfs_segctor_wait_request wait_req;
2173 int err = 0;
2174
2175 spin_lock(&sci->sc_state_lock);
2176 init_wait(&wait_req.wq);
2177 wait_req.err = 0;
2178 atomic_set(&wait_req.done, 0);
2179 wait_req.seq = ++sci->sc_seq_request;
2180 spin_unlock(&sci->sc_state_lock);
2181
2182 init_waitqueue_entry(&wait_req.wq, current);
2183 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2184 set_current_state(TASK_INTERRUPTIBLE);
2185 wake_up(&sci->sc_wait_daemon);
2186
2187 for (;;) {
2188 if (atomic_read(&wait_req.done)) {
2189 err = wait_req.err;
2190 break;
2191 }
2192 if (!signal_pending(current)) {
2193 schedule();
2194 continue;
2195 }
2196 err = -ERESTARTSYS;
2197 break;
2198 }
2199 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2200 return err;
2201 }
2202
2203 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2204 {
2205 struct nilfs_segctor_wait_request *wrq, *n;
2206 unsigned long flags;
2207
2208 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2209 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2210 wq.task_list) {
2211 if (!atomic_read(&wrq->done) &&
2212 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2213 wrq->err = err;
2214 atomic_set(&wrq->done, 1);
2215 }
2216 if (atomic_read(&wrq->done)) {
2217 wrq->wq.func(&wrq->wq,
2218 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2219 0, NULL);
2220 }
2221 }
2222 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2223 }
2224
2225 /**
2226 * nilfs_construct_segment - construct a logical segment
2227 * @sb: super block
2228 *
2229 * Return Value: On success, 0 is retured. On errors, one of the following
2230 * negative error code is returned.
2231 *
2232 * %-EROFS - Read only filesystem.
2233 *
2234 * %-EIO - I/O error
2235 *
2236 * %-ENOSPC - No space left on device (only in a panic state).
2237 *
2238 * %-ERESTARTSYS - Interrupted.
2239 *
2240 * %-ENOMEM - Insufficient memory available.
2241 */
2242 int nilfs_construct_segment(struct super_block *sb)
2243 {
2244 struct the_nilfs *nilfs = sb->s_fs_info;
2245 struct nilfs_sc_info *sci = nilfs->ns_writer;
2246 struct nilfs_transaction_info *ti;
2247 int err;
2248
2249 if (!sci)
2250 return -EROFS;
2251
2252 /* A call inside transactions causes a deadlock. */
2253 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2254
2255 err = nilfs_segctor_sync(sci);
2256 return err;
2257 }
2258
2259 /**
2260 * nilfs_construct_dsync_segment - construct a data-only logical segment
2261 * @sb: super block
2262 * @inode: inode whose data blocks should be written out
2263 * @start: start byte offset
2264 * @end: end byte offset (inclusive)
2265 *
2266 * Return Value: On success, 0 is retured. On errors, one of the following
2267 * negative error code is returned.
2268 *
2269 * %-EROFS - Read only filesystem.
2270 *
2271 * %-EIO - I/O error
2272 *
2273 * %-ENOSPC - No space left on device (only in a panic state).
2274 *
2275 * %-ERESTARTSYS - Interrupted.
2276 *
2277 * %-ENOMEM - Insufficient memory available.
2278 */
2279 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2280 loff_t start, loff_t end)
2281 {
2282 struct the_nilfs *nilfs = sb->s_fs_info;
2283 struct nilfs_sc_info *sci = nilfs->ns_writer;
2284 struct nilfs_inode_info *ii;
2285 struct nilfs_transaction_info ti;
2286 int err = 0;
2287
2288 if (!sci)
2289 return -EROFS;
2290
2291 nilfs_transaction_lock(sb, &ti, 0);
2292
2293 ii = NILFS_I(inode);
2294 if (test_bit(NILFS_I_INODE_SYNC, &ii->i_state) ||
2295 nilfs_test_opt(nilfs, STRICT_ORDER) ||
2296 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2297 nilfs_discontinued(nilfs)) {
2298 nilfs_transaction_unlock(sb);
2299 err = nilfs_segctor_sync(sci);
2300 return err;
2301 }
2302
2303 spin_lock(&nilfs->ns_inode_lock);
2304 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2305 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2306 spin_unlock(&nilfs->ns_inode_lock);
2307 nilfs_transaction_unlock(sb);
2308 return 0;
2309 }
2310 spin_unlock(&nilfs->ns_inode_lock);
2311 sci->sc_dsync_inode = ii;
2312 sci->sc_dsync_start = start;
2313 sci->sc_dsync_end = end;
2314
2315 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2316 if (!err)
2317 nilfs->ns_flushed_device = 0;
2318
2319 nilfs_transaction_unlock(sb);
2320 return err;
2321 }
2322
2323 #define FLUSH_FILE_BIT (0x1) /* data file only */
2324 #define FLUSH_DAT_BIT BIT(NILFS_DAT_INO) /* DAT only */
2325
2326 /**
2327 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2328 * @sci: segment constructor object
2329 */
2330 static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2331 {
2332 spin_lock(&sci->sc_state_lock);
2333 sci->sc_seq_accepted = sci->sc_seq_request;
2334 spin_unlock(&sci->sc_state_lock);
2335 del_timer_sync(&sci->sc_timer);
2336 }
2337
2338 /**
2339 * nilfs_segctor_notify - notify the result of request to caller threads
2340 * @sci: segment constructor object
2341 * @mode: mode of log forming
2342 * @err: error code to be notified
2343 */
2344 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2345 {
2346 /* Clear requests (even when the construction failed) */
2347 spin_lock(&sci->sc_state_lock);
2348
2349 if (mode == SC_LSEG_SR) {
2350 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2351 sci->sc_seq_done = sci->sc_seq_accepted;
2352 nilfs_segctor_wakeup(sci, err);
2353 sci->sc_flush_request = 0;
2354 } else {
2355 if (mode == SC_FLUSH_FILE)
2356 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2357 else if (mode == SC_FLUSH_DAT)
2358 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2359
2360 /* re-enable timer if checkpoint creation was not done */
2361 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2362 time_before(jiffies, sci->sc_timer.expires))
2363 add_timer(&sci->sc_timer);
2364 }
2365 spin_unlock(&sci->sc_state_lock);
2366 }
2367
2368 /**
2369 * nilfs_segctor_construct - form logs and write them to disk
2370 * @sci: segment constructor object
2371 * @mode: mode of log forming
2372 */
2373 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2374 {
2375 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2376 struct nilfs_super_block **sbp;
2377 int err = 0;
2378
2379 nilfs_segctor_accept(sci);
2380
2381 if (nilfs_discontinued(nilfs))
2382 mode = SC_LSEG_SR;
2383 if (!nilfs_segctor_confirm(sci))
2384 err = nilfs_segctor_do_construct(sci, mode);
2385
2386 if (likely(!err)) {
2387 if (mode != SC_FLUSH_DAT)
2388 atomic_set(&nilfs->ns_ndirtyblks, 0);
2389 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2390 nilfs_discontinued(nilfs)) {
2391 down_write(&nilfs->ns_sem);
2392 err = -EIO;
2393 sbp = nilfs_prepare_super(sci->sc_super,
2394 nilfs_sb_will_flip(nilfs));
2395 if (likely(sbp)) {
2396 nilfs_set_log_cursor(sbp[0], nilfs);
2397 err = nilfs_commit_super(sci->sc_super,
2398 NILFS_SB_COMMIT);
2399 }
2400 up_write(&nilfs->ns_sem);
2401 }
2402 }
2403
2404 nilfs_segctor_notify(sci, mode, err);
2405 return err;
2406 }
2407
2408 static void nilfs_construction_timeout(unsigned long data)
2409 {
2410 struct task_struct *p = (struct task_struct *)data;
2411
2412 wake_up_process(p);
2413 }
2414
2415 static void
2416 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2417 {
2418 struct nilfs_inode_info *ii, *n;
2419
2420 list_for_each_entry_safe(ii, n, head, i_dirty) {
2421 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2422 continue;
2423 list_del_init(&ii->i_dirty);
2424 truncate_inode_pages(&ii->vfs_inode.i_data, 0);
2425 nilfs_btnode_cache_clear(&ii->i_btnode_cache);
2426 iput(&ii->vfs_inode);
2427 }
2428 }
2429
2430 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2431 void **kbufs)
2432 {
2433 struct the_nilfs *nilfs = sb->s_fs_info;
2434 struct nilfs_sc_info *sci = nilfs->ns_writer;
2435 struct nilfs_transaction_info ti;
2436 int err;
2437
2438 if (unlikely(!sci))
2439 return -EROFS;
2440
2441 nilfs_transaction_lock(sb, &ti, 1);
2442
2443 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2444 if (unlikely(err))
2445 goto out_unlock;
2446
2447 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2448 if (unlikely(err)) {
2449 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2450 goto out_unlock;
2451 }
2452
2453 sci->sc_freesegs = kbufs[4];
2454 sci->sc_nfreesegs = argv[4].v_nmembs;
2455 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2456
2457 for (;;) {
2458 err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2459 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2460
2461 if (likely(!err))
2462 break;
2463
2464 nilfs_msg(sb, KERN_WARNING, "error %d cleaning segments", err);
2465 set_current_state(TASK_INTERRUPTIBLE);
2466 schedule_timeout(sci->sc_interval);
2467 }
2468 if (nilfs_test_opt(nilfs, DISCARD)) {
2469 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2470 sci->sc_nfreesegs);
2471 if (ret) {
2472 nilfs_msg(sb, KERN_WARNING,
2473 "error %d on discard request, turning discards off for the device",
2474 ret);
2475 nilfs_clear_opt(nilfs, DISCARD);
2476 }
2477 }
2478
2479 out_unlock:
2480 sci->sc_freesegs = NULL;
2481 sci->sc_nfreesegs = 0;
2482 nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2483 nilfs_transaction_unlock(sb);
2484 return err;
2485 }
2486
2487 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2488 {
2489 struct nilfs_transaction_info ti;
2490
2491 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2492 nilfs_segctor_construct(sci, mode);
2493
2494 /*
2495 * Unclosed segment should be retried. We do this using sc_timer.
2496 * Timeout of sc_timer will invoke complete construction which leads
2497 * to close the current logical segment.
2498 */
2499 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2500 nilfs_segctor_start_timer(sci);
2501
2502 nilfs_transaction_unlock(sci->sc_super);
2503 }
2504
2505 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2506 {
2507 int mode = 0;
2508
2509 spin_lock(&sci->sc_state_lock);
2510 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2511 SC_FLUSH_DAT : SC_FLUSH_FILE;
2512 spin_unlock(&sci->sc_state_lock);
2513
2514 if (mode) {
2515 nilfs_segctor_do_construct(sci, mode);
2516
2517 spin_lock(&sci->sc_state_lock);
2518 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2519 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2520 spin_unlock(&sci->sc_state_lock);
2521 }
2522 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2523 }
2524
2525 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2526 {
2527 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2528 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2529 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2530 return SC_FLUSH_FILE;
2531 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2532 return SC_FLUSH_DAT;
2533 }
2534 return SC_LSEG_SR;
2535 }
2536
2537 /**
2538 * nilfs_segctor_thread - main loop of the segment constructor thread.
2539 * @arg: pointer to a struct nilfs_sc_info.
2540 *
2541 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2542 * to execute segment constructions.
2543 */
2544 static int nilfs_segctor_thread(void *arg)
2545 {
2546 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2547 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2548 int timeout = 0;
2549
2550 sci->sc_timer.data = (unsigned long)current;
2551 sci->sc_timer.function = nilfs_construction_timeout;
2552
2553 /* start sync. */
2554 sci->sc_task = current;
2555 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2556 nilfs_msg(sci->sc_super, KERN_INFO,
2557 "segctord starting. Construction interval = %lu seconds, CP frequency < %lu seconds",
2558 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2559
2560 spin_lock(&sci->sc_state_lock);
2561 loop:
2562 for (;;) {
2563 int mode;
2564
2565 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2566 goto end_thread;
2567
2568 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2569 mode = SC_LSEG_SR;
2570 else if (sci->sc_flush_request)
2571 mode = nilfs_segctor_flush_mode(sci);
2572 else
2573 break;
2574
2575 spin_unlock(&sci->sc_state_lock);
2576 nilfs_segctor_thread_construct(sci, mode);
2577 spin_lock(&sci->sc_state_lock);
2578 timeout = 0;
2579 }
2580
2581
2582 if (freezing(current)) {
2583 spin_unlock(&sci->sc_state_lock);
2584 try_to_freeze();
2585 spin_lock(&sci->sc_state_lock);
2586 } else {
2587 DEFINE_WAIT(wait);
2588 int should_sleep = 1;
2589
2590 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2591 TASK_INTERRUPTIBLE);
2592
2593 if (sci->sc_seq_request != sci->sc_seq_done)
2594 should_sleep = 0;
2595 else if (sci->sc_flush_request)
2596 should_sleep = 0;
2597 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2598 should_sleep = time_before(jiffies,
2599 sci->sc_timer.expires);
2600
2601 if (should_sleep) {
2602 spin_unlock(&sci->sc_state_lock);
2603 schedule();
2604 spin_lock(&sci->sc_state_lock);
2605 }
2606 finish_wait(&sci->sc_wait_daemon, &wait);
2607 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2608 time_after_eq(jiffies, sci->sc_timer.expires));
2609
2610 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2611 set_nilfs_discontinued(nilfs);
2612 }
2613 goto loop;
2614
2615 end_thread:
2616 spin_unlock(&sci->sc_state_lock);
2617
2618 /* end sync. */
2619 sci->sc_task = NULL;
2620 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2621 return 0;
2622 }
2623
2624 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2625 {
2626 struct task_struct *t;
2627
2628 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2629 if (IS_ERR(t)) {
2630 int err = PTR_ERR(t);
2631
2632 nilfs_msg(sci->sc_super, KERN_ERR,
2633 "error %d creating segctord thread", err);
2634 return err;
2635 }
2636 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2637 return 0;
2638 }
2639
2640 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2641 __acquires(&sci->sc_state_lock)
2642 __releases(&sci->sc_state_lock)
2643 {
2644 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2645
2646 while (sci->sc_task) {
2647 wake_up(&sci->sc_wait_daemon);
2648 spin_unlock(&sci->sc_state_lock);
2649 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2650 spin_lock(&sci->sc_state_lock);
2651 }
2652 }
2653
2654 /*
2655 * Setup & clean-up functions
2656 */
2657 static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
2658 struct nilfs_root *root)
2659 {
2660 struct the_nilfs *nilfs = sb->s_fs_info;
2661 struct nilfs_sc_info *sci;
2662
2663 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2664 if (!sci)
2665 return NULL;
2666
2667 sci->sc_super = sb;
2668
2669 nilfs_get_root(root);
2670 sci->sc_root = root;
2671
2672 init_waitqueue_head(&sci->sc_wait_request);
2673 init_waitqueue_head(&sci->sc_wait_daemon);
2674 init_waitqueue_head(&sci->sc_wait_task);
2675 spin_lock_init(&sci->sc_state_lock);
2676 INIT_LIST_HEAD(&sci->sc_dirty_files);
2677 INIT_LIST_HEAD(&sci->sc_segbufs);
2678 INIT_LIST_HEAD(&sci->sc_write_logs);
2679 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2680 INIT_LIST_HEAD(&sci->sc_iput_queue);
2681 INIT_WORK(&sci->sc_iput_work, nilfs_iput_work_func);
2682 init_timer(&sci->sc_timer);
2683
2684 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2685 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2686 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2687
2688 if (nilfs->ns_interval)
2689 sci->sc_interval = HZ * nilfs->ns_interval;
2690 if (nilfs->ns_watermark)
2691 sci->sc_watermark = nilfs->ns_watermark;
2692 return sci;
2693 }
2694
2695 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2696 {
2697 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2698
2699 /*
2700 * The segctord thread was stopped and its timer was removed.
2701 * But some tasks remain.
2702 */
2703 do {
2704 struct nilfs_transaction_info ti;
2705
2706 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2707 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2708 nilfs_transaction_unlock(sci->sc_super);
2709
2710 flush_work(&sci->sc_iput_work);
2711
2712 } while (ret && retrycount-- > 0);
2713 }
2714
2715 /**
2716 * nilfs_segctor_destroy - destroy the segment constructor.
2717 * @sci: nilfs_sc_info
2718 *
2719 * nilfs_segctor_destroy() kills the segctord thread and frees
2720 * the nilfs_sc_info struct.
2721 * Caller must hold the segment semaphore.
2722 */
2723 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2724 {
2725 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2726 int flag;
2727
2728 up_write(&nilfs->ns_segctor_sem);
2729
2730 spin_lock(&sci->sc_state_lock);
2731 nilfs_segctor_kill_thread(sci);
2732 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2733 || sci->sc_seq_request != sci->sc_seq_done);
2734 spin_unlock(&sci->sc_state_lock);
2735
2736 if (flush_work(&sci->sc_iput_work))
2737 flag = true;
2738
2739 if (flag || !nilfs_segctor_confirm(sci))
2740 nilfs_segctor_write_out(sci);
2741
2742 if (!list_empty(&sci->sc_dirty_files)) {
2743 nilfs_msg(sci->sc_super, KERN_WARNING,
2744 "disposed unprocessed dirty file(s) when stopping log writer");
2745 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
2746 }
2747
2748 if (!list_empty(&sci->sc_iput_queue)) {
2749 nilfs_msg(sci->sc_super, KERN_WARNING,
2750 "disposed unprocessed inode(s) in iput queue when stopping log writer");
2751 nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 1);
2752 }
2753
2754 WARN_ON(!list_empty(&sci->sc_segbufs));
2755 WARN_ON(!list_empty(&sci->sc_write_logs));
2756
2757 nilfs_put_root(sci->sc_root);
2758
2759 down_write(&nilfs->ns_segctor_sem);
2760
2761 del_timer_sync(&sci->sc_timer);
2762 kfree(sci);
2763 }
2764
2765 /**
2766 * nilfs_attach_log_writer - attach log writer
2767 * @sb: super block instance
2768 * @root: root object of the current filesystem tree
2769 *
2770 * This allocates a log writer object, initializes it, and starts the
2771 * log writer.
2772 *
2773 * Return Value: On success, 0 is returned. On error, one of the following
2774 * negative error code is returned.
2775 *
2776 * %-ENOMEM - Insufficient memory available.
2777 */
2778 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
2779 {
2780 struct the_nilfs *nilfs = sb->s_fs_info;
2781 int err;
2782
2783 if (nilfs->ns_writer) {
2784 /*
2785 * This happens if the filesystem was remounted
2786 * read/write after nilfs_error degenerated it into a
2787 * read-only mount.
2788 */
2789 nilfs_detach_log_writer(sb);
2790 }
2791
2792 nilfs->ns_writer = nilfs_segctor_new(sb, root);
2793 if (!nilfs->ns_writer)
2794 return -ENOMEM;
2795
2796 err = nilfs_segctor_start_thread(nilfs->ns_writer);
2797 if (err) {
2798 kfree(nilfs->ns_writer);
2799 nilfs->ns_writer = NULL;
2800 }
2801 return err;
2802 }
2803
2804 /**
2805 * nilfs_detach_log_writer - destroy log writer
2806 * @sb: super block instance
2807 *
2808 * This kills log writer daemon, frees the log writer object, and
2809 * destroys list of dirty files.
2810 */
2811 void nilfs_detach_log_writer(struct super_block *sb)
2812 {
2813 struct the_nilfs *nilfs = sb->s_fs_info;
2814 LIST_HEAD(garbage_list);
2815
2816 down_write(&nilfs->ns_segctor_sem);
2817 if (nilfs->ns_writer) {
2818 nilfs_segctor_destroy(nilfs->ns_writer);
2819 nilfs->ns_writer = NULL;
2820 }
2821
2822 /* Force to free the list of dirty files */
2823 spin_lock(&nilfs->ns_inode_lock);
2824 if (!list_empty(&nilfs->ns_dirty_files)) {
2825 list_splice_init(&nilfs->ns_dirty_files, &garbage_list);
2826 nilfs_msg(sb, KERN_WARNING,
2827 "disposed unprocessed dirty file(s) when detaching log writer");
2828 }
2829 spin_unlock(&nilfs->ns_inode_lock);
2830 up_write(&nilfs->ns_segctor_sem);
2831
2832 nilfs_dispose_list(nilfs, &garbage_list, 1);
2833 }
Linux with added FPC-III support