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Staging: android: lowmemorykiller.c: fix it for "oom: move oom_adj value from task_st...
[linux-2.6/mini2440.git] / fs / nilfs2 / segment.c
blob8b5e4778cf28bc780fcf516400ccc7a2e963c076
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/bio.h>
28 #include <linux/completion.h>
29 #include <linux/blkdev.h>
30 #include <linux/backing-dev.h>
31 #include <linux/freezer.h>
32 #include <linux/kthread.h>
33 #include <linux/crc32.h>
34 #include <linux/pagevec.h>
35 #include "nilfs.h"
36 #include "btnode.h"
37 #include "page.h"
38 #include "segment.h"
39 #include "sufile.h"
40 #include "cpfile.h"
41 #include "ifile.h"
42 #include "segbuf.h"
43
44
45 /*
46 * Segment constructor
47 */
48 #define SC_N_INODEVEC 16 /* Size of locally allocated inode vector */
49
50 #define SC_MAX_SEGDELTA 64 /* Upper limit of the number of segments
51 appended in collection retry loop */
52
53 /* Construction mode */
54 enum {
55 SC_LSEG_SR = 1, /* Make a logical segment having a super root */
56 SC_LSEG_DSYNC, /* Flush data blocks of a given file and make
57 a logical segment without a super root */
58 SC_FLUSH_FILE, /* Flush data files, leads to segment writes without
59 creating a checkpoint */
60 SC_FLUSH_DAT, /* Flush DAT file. This also creates segments without
61 a checkpoint */
62 };
63
64 /* Stage numbers of dirty block collection */
65 enum {
66 NILFS_ST_INIT = 0,
67 NILFS_ST_GC, /* Collecting dirty blocks for GC */
68 NILFS_ST_FILE,
69 NILFS_ST_IFILE,
70 NILFS_ST_CPFILE,
71 NILFS_ST_SUFILE,
72 NILFS_ST_DAT,
73 NILFS_ST_SR, /* Super root */
74 NILFS_ST_DSYNC, /* Data sync blocks */
75 NILFS_ST_DONE,
76 };
77
78 /* State flags of collection */
79 #define NILFS_CF_NODE 0x0001 /* Collecting node blocks */
80 #define NILFS_CF_IFILE_STARTED 0x0002 /* IFILE stage has started */
81 #define NILFS_CF_SUFREED 0x0004 /* segment usages has been freed */
82 #define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED)
83
84 /* Operations depending on the construction mode and file type */
85 struct nilfs_sc_operations {
86 int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *,
87 struct inode *);
88 int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *,
89 struct inode *);
90 int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *,
91 struct inode *);
92 void (*write_data_binfo)(struct nilfs_sc_info *,
93 struct nilfs_segsum_pointer *,
94 union nilfs_binfo *);
95 void (*write_node_binfo)(struct nilfs_sc_info *,
96 struct nilfs_segsum_pointer *,
97 union nilfs_binfo *);
98 };
99
100 /*
101 * Other definitions
102 */
103 static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
104 static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
105 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
106 static void nilfs_dispose_list(struct nilfs_sb_info *, struct list_head *,
107 int);
108
109 #define nilfs_cnt32_gt(a, b) \
110 (typecheck(__u32, a) && typecheck(__u32, b) && \
111 ((__s32)(b) - (__s32)(a) < 0))
112 #define nilfs_cnt32_ge(a, b) \
113 (typecheck(__u32, a) && typecheck(__u32, b) && \
114 ((__s32)(a) - (__s32)(b) >= 0))
115 #define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a)
116 #define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a)
117
118 /*
119 * Transaction
120 */
121 static struct kmem_cache *nilfs_transaction_cachep;
122
123 /**
124 * nilfs_init_transaction_cache - create a cache for nilfs_transaction_info
125 *
126 * nilfs_init_transaction_cache() creates a slab cache for the struct
127 * nilfs_transaction_info.
128 *
129 * Return Value: On success, it returns 0. On error, one of the following
130 * negative error code is returned.
131 *
132 * %-ENOMEM - Insufficient memory available.
133 */
134 int nilfs_init_transaction_cache(void)
135 {
136 nilfs_transaction_cachep =
137 kmem_cache_create("nilfs2_transaction_cache",
138 sizeof(struct nilfs_transaction_info),
139 0, SLAB_RECLAIM_ACCOUNT, NULL);
140 return (nilfs_transaction_cachep == NULL) ? -ENOMEM : 0;
141 }
142
143 /**
144 * nilfs_detroy_transaction_cache - destroy the cache for transaction info
145 *
146 * nilfs_destroy_transaction_cache() frees the slab cache for the struct
147 * nilfs_transaction_info.
148 */
149 void nilfs_destroy_transaction_cache(void)
150 {
151 kmem_cache_destroy(nilfs_transaction_cachep);
152 }
153
154 static int nilfs_prepare_segment_lock(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 else {
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 printk(KERN_WARNING
169 "NILFS warning: journal info from a different "
170 "FS\n");
171 save = current->journal_info;
172 }
173 }
174 if (!ti) {
175 ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
176 if (!ti)
177 return -ENOMEM;
178 ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
179 } else {
180 ti->ti_flags = 0;
181 }
182 ti->ti_count = 0;
183 ti->ti_save = save;
184 ti->ti_magic = NILFS_TI_MAGIC;
185 current->journal_info = ti;
186 return 0;
187 }
188
189 /**
190 * nilfs_transaction_begin - start indivisible file operations.
191 * @sb: super block
192 * @ti: nilfs_transaction_info
193 * @vacancy_check: flags for vacancy rate checks
194 *
195 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
196 * the segment semaphore, to make a segment construction and write tasks
197 * exclusive. The function is used with nilfs_transaction_commit() in pairs.
198 * The region enclosed by these two functions can be nested. To avoid a
199 * deadlock, the semaphore is only acquired or released in the outermost call.
200 *
201 * This function allocates a nilfs_transaction_info struct to keep context
202 * information on it. It is initialized and hooked onto the current task in
203 * the outermost call. If a pre-allocated struct is given to @ti, it is used
204 * instead; othewise a new struct is assigned from a slab.
205 *
206 * When @vacancy_check flag is set, this function will check the amount of
207 * free space, and will wait for the GC to reclaim disk space if low capacity.
208 *
209 * Return Value: On success, 0 is returned. On error, one of the following
210 * negative error code is returned.
211 *
212 * %-ENOMEM - Insufficient memory available.
213 *
214 * %-ENOSPC - No space left on device
215 */
216 int nilfs_transaction_begin(struct super_block *sb,
217 struct nilfs_transaction_info *ti,
218 int vacancy_check)
219 {
220 struct nilfs_sb_info *sbi;
221 struct the_nilfs *nilfs;
222 int ret = nilfs_prepare_segment_lock(ti);
223
224 if (unlikely(ret < 0))
225 return ret;
226 if (ret > 0)
227 return 0;
228
229 sbi = NILFS_SB(sb);
230 nilfs = sbi->s_nilfs;
231 down_read(&nilfs->ns_segctor_sem);
232 if (vacancy_check && nilfs_near_disk_full(nilfs)) {
233 up_read(&nilfs->ns_segctor_sem);
234 ret = -ENOSPC;
235 goto failed;
236 }
237 return 0;
238
239 failed:
240 ti = current->journal_info;
241 current->journal_info = ti->ti_save;
242 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
243 kmem_cache_free(nilfs_transaction_cachep, ti);
244 return ret;
245 }
246
247 /**
248 * nilfs_transaction_commit - commit indivisible file operations.
249 * @sb: super block
250 *
251 * nilfs_transaction_commit() releases the read semaphore which is
252 * acquired by nilfs_transaction_begin(). This is only performed
253 * in outermost call of this function. If a commit flag is set,
254 * nilfs_transaction_commit() sets a timer to start the segment
255 * constructor. If a sync flag is set, it starts construction
256 * directly.
257 */
258 int nilfs_transaction_commit(struct super_block *sb)
259 {
260 struct nilfs_transaction_info *ti = current->journal_info;
261 struct nilfs_sb_info *sbi;
262 struct nilfs_sc_info *sci;
263 int err = 0;
264
265 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
266 ti->ti_flags |= NILFS_TI_COMMIT;
267 if (ti->ti_count > 0) {
268 ti->ti_count--;
269 return 0;
270 }
271 sbi = NILFS_SB(sb);
272 sci = NILFS_SC(sbi);
273 if (sci != NULL) {
274 if (ti->ti_flags & NILFS_TI_COMMIT)
275 nilfs_segctor_start_timer(sci);
276 if (atomic_read(&sbi->s_nilfs->ns_ndirtyblks) >
277 sci->sc_watermark)
278 nilfs_segctor_do_flush(sci, 0);
279 }
280 up_read(&sbi->s_nilfs->ns_segctor_sem);
281 current->journal_info = ti->ti_save;
282
283 if (ti->ti_flags & NILFS_TI_SYNC)
284 err = nilfs_construct_segment(sb);
285 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
286 kmem_cache_free(nilfs_transaction_cachep, ti);
287 return err;
288 }
289
290 void nilfs_transaction_abort(struct super_block *sb)
291 {
292 struct nilfs_transaction_info *ti = current->journal_info;
293
294 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
295 if (ti->ti_count > 0) {
296 ti->ti_count--;
297 return;
298 }
299 up_read(&NILFS_SB(sb)->s_nilfs->ns_segctor_sem);
300
301 current->journal_info = ti->ti_save;
302 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
303 kmem_cache_free(nilfs_transaction_cachep, ti);
304 }
305
306 void nilfs_relax_pressure_in_lock(struct super_block *sb)
307 {
308 struct nilfs_sb_info *sbi = NILFS_SB(sb);
309 struct nilfs_sc_info *sci = NILFS_SC(sbi);
310 struct the_nilfs *nilfs = sbi->s_nilfs;
311
312 if (!sci || !sci->sc_flush_request)
313 return;
314
315 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
316 up_read(&nilfs->ns_segctor_sem);
317
318 down_write(&nilfs->ns_segctor_sem);
319 if (sci->sc_flush_request &&
320 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
321 struct nilfs_transaction_info *ti = current->journal_info;
322
323 ti->ti_flags |= NILFS_TI_WRITER;
324 nilfs_segctor_do_immediate_flush(sci);
325 ti->ti_flags &= ~NILFS_TI_WRITER;
326 }
327 downgrade_write(&nilfs->ns_segctor_sem);
328 }
329
330 static void nilfs_transaction_lock(struct nilfs_sb_info *sbi,
331 struct nilfs_transaction_info *ti,
332 int gcflag)
333 {
334 struct nilfs_transaction_info *cur_ti = current->journal_info;
335
336 WARN_ON(cur_ti);
337 ti->ti_flags = NILFS_TI_WRITER;
338 ti->ti_count = 0;
339 ti->ti_save = cur_ti;
340 ti->ti_magic = NILFS_TI_MAGIC;
341 INIT_LIST_HEAD(&ti->ti_garbage);
342 current->journal_info = ti;
343
344 for (;;) {
345 down_write(&sbi->s_nilfs->ns_segctor_sem);
346 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &NILFS_SC(sbi)->sc_flags))
347 break;
348
349 nilfs_segctor_do_immediate_flush(NILFS_SC(sbi));
350
351 up_write(&sbi->s_nilfs->ns_segctor_sem);
352 yield();
353 }
354 if (gcflag)
355 ti->ti_flags |= NILFS_TI_GC;
356 }
357
358 static void nilfs_transaction_unlock(struct nilfs_sb_info *sbi)
359 {
360 struct nilfs_transaction_info *ti = current->journal_info;
361
362 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
363 BUG_ON(ti->ti_count > 0);
364
365 up_write(&sbi->s_nilfs->ns_segctor_sem);
366 current->journal_info = ti->ti_save;
367 if (!list_empty(&ti->ti_garbage))
368 nilfs_dispose_list(sbi, &ti->ti_garbage, 0);
369 }
370
371 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
372 struct nilfs_segsum_pointer *ssp,
373 unsigned bytes)
374 {
375 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
376 unsigned blocksize = sci->sc_super->s_blocksize;
377 void *p;
378
379 if (unlikely(ssp->offset + bytes > blocksize)) {
380 ssp->offset = 0;
381 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
382 &segbuf->sb_segsum_buffers));
383 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
384 }
385 p = ssp->bh->b_data + ssp->offset;
386 ssp->offset += bytes;
387 return p;
388 }
389
390 /**
391 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
392 * @sci: nilfs_sc_info
393 */
394 static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
395 {
396 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
397 struct buffer_head *sumbh;
398 unsigned sumbytes;
399 unsigned flags = 0;
400 int err;
401
402 if (nilfs_doing_gc())
403 flags = NILFS_SS_GC;
404 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime);
405 if (unlikely(err))
406 return err;
407
408 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
409 sumbytes = segbuf->sb_sum.sumbytes;
410 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
411 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
412 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
413 return 0;
414 }
415
416 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
417 {
418 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
419 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
420 return -E2BIG; /* The current segment is filled up
421 (internal code) */
422 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
423 return nilfs_segctor_reset_segment_buffer(sci);
424 }
425
426 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
427 {
428 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
429 int err;
430
431 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
432 err = nilfs_segctor_feed_segment(sci);
433 if (err)
434 return err;
435 segbuf = sci->sc_curseg;
436 }
437 err = nilfs_segbuf_extend_payload(segbuf, &sci->sc_super_root);
438 if (likely(!err))
439 segbuf->sb_sum.flags |= NILFS_SS_SR;
440 return err;
441 }
442
443 /*
444 * Functions for making segment summary and payloads
445 */
446 static int nilfs_segctor_segsum_block_required(
447 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
448 unsigned binfo_size)
449 {
450 unsigned blocksize = sci->sc_super->s_blocksize;
451 /* Size of finfo and binfo is enough small against blocksize */
452
453 return ssp->offset + binfo_size +
454 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
455 blocksize;
456 }
457
458 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
459 struct inode *inode)
460 {
461 sci->sc_curseg->sb_sum.nfinfo++;
462 sci->sc_binfo_ptr = sci->sc_finfo_ptr;
463 nilfs_segctor_map_segsum_entry(
464 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
465
466 if (inode->i_sb && !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
467 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
468 /* skip finfo */
469 }
470
471 static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
472 struct inode *inode)
473 {
474 struct nilfs_finfo *finfo;
475 struct nilfs_inode_info *ii;
476 struct nilfs_segment_buffer *segbuf;
477
478 if (sci->sc_blk_cnt == 0)
479 return;
480
481 ii = NILFS_I(inode);
482 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
483 sizeof(*finfo));
484 finfo->fi_ino = cpu_to_le64(inode->i_ino);
485 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
486 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
487 finfo->fi_cno = cpu_to_le64(ii->i_cno);
488
489 segbuf = sci->sc_curseg;
490 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
491 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
492 sci->sc_finfo_ptr = sci->sc_binfo_ptr;
493 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
494 }
495
496 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
497 struct buffer_head *bh,
498 struct inode *inode,
499 unsigned binfo_size)
500 {
501 struct nilfs_segment_buffer *segbuf;
502 int required, err = 0;
503
504 retry:
505 segbuf = sci->sc_curseg;
506 required = nilfs_segctor_segsum_block_required(
507 sci, &sci->sc_binfo_ptr, binfo_size);
508 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
509 nilfs_segctor_end_finfo(sci, inode);
510 err = nilfs_segctor_feed_segment(sci);
511 if (err)
512 return err;
513 goto retry;
514 }
515 if (unlikely(required)) {
516 err = nilfs_segbuf_extend_segsum(segbuf);
517 if (unlikely(err))
518 goto failed;
519 }
520 if (sci->sc_blk_cnt == 0)
521 nilfs_segctor_begin_finfo(sci, inode);
522
523 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
524 /* Substitution to vblocknr is delayed until update_blocknr() */
525 nilfs_segbuf_add_file_buffer(segbuf, bh);
526 sci->sc_blk_cnt++;
527 failed:
528 return err;
529 }
530
531 static int nilfs_handle_bmap_error(int err, const char *fname,
532 struct inode *inode, struct super_block *sb)
533 {
534 if (err == -EINVAL) {
535 nilfs_error(sb, fname, "broken bmap (inode=%lu)\n",
536 inode->i_ino);
537 err = -EIO;
538 }
539 return err;
540 }
541
542 /*
543 * Callback functions that enumerate, mark, and collect dirty blocks
544 */
545 static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
546 struct buffer_head *bh, struct inode *inode)
547 {
548 int err;
549
550 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
551 if (unlikely(err < 0))
552 return nilfs_handle_bmap_error(err, __func__, inode,
553 sci->sc_super);
554
555 err = nilfs_segctor_add_file_block(sci, bh, inode,
556 sizeof(struct nilfs_binfo_v));
557 if (!err)
558 sci->sc_datablk_cnt++;
559 return err;
560 }
561
562 static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
563 struct buffer_head *bh,
564 struct inode *inode)
565 {
566 int err;
567
568 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
569 if (unlikely(err < 0))
570 return nilfs_handle_bmap_error(err, __func__, inode,
571 sci->sc_super);
572 return 0;
573 }
574
575 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
576 struct buffer_head *bh,
577 struct inode *inode)
578 {
579 WARN_ON(!buffer_dirty(bh));
580 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
581 }
582
583 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
584 struct nilfs_segsum_pointer *ssp,
585 union nilfs_binfo *binfo)
586 {
587 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
588 sci, ssp, sizeof(*binfo_v));
589 *binfo_v = binfo->bi_v;
590 }
591
592 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
593 struct nilfs_segsum_pointer *ssp,
594 union nilfs_binfo *binfo)
595 {
596 __le64 *vblocknr = nilfs_segctor_map_segsum_entry(
597 sci, ssp, sizeof(*vblocknr));
598 *vblocknr = binfo->bi_v.bi_vblocknr;
599 }
600
601 struct nilfs_sc_operations nilfs_sc_file_ops = {
602 .collect_data = nilfs_collect_file_data,
603 .collect_node = nilfs_collect_file_node,
604 .collect_bmap = nilfs_collect_file_bmap,
605 .write_data_binfo = nilfs_write_file_data_binfo,
606 .write_node_binfo = nilfs_write_file_node_binfo,
607 };
608
609 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
610 struct buffer_head *bh, struct inode *inode)
611 {
612 int err;
613
614 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
615 if (unlikely(err < 0))
616 return nilfs_handle_bmap_error(err, __func__, inode,
617 sci->sc_super);
618
619 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
620 if (!err)
621 sci->sc_datablk_cnt++;
622 return err;
623 }
624
625 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
626 struct buffer_head *bh, struct inode *inode)
627 {
628 WARN_ON(!buffer_dirty(bh));
629 return nilfs_segctor_add_file_block(sci, bh, inode,
630 sizeof(struct nilfs_binfo_dat));
631 }
632
633 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
634 struct nilfs_segsum_pointer *ssp,
635 union nilfs_binfo *binfo)
636 {
637 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
638 sizeof(*blkoff));
639 *blkoff = binfo->bi_dat.bi_blkoff;
640 }
641
642 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
643 struct nilfs_segsum_pointer *ssp,
644 union nilfs_binfo *binfo)
645 {
646 struct nilfs_binfo_dat *binfo_dat =
647 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
648 *binfo_dat = binfo->bi_dat;
649 }
650
651 struct nilfs_sc_operations nilfs_sc_dat_ops = {
652 .collect_data = nilfs_collect_dat_data,
653 .collect_node = nilfs_collect_file_node,
654 .collect_bmap = nilfs_collect_dat_bmap,
655 .write_data_binfo = nilfs_write_dat_data_binfo,
656 .write_node_binfo = nilfs_write_dat_node_binfo,
657 };
658
659 struct nilfs_sc_operations nilfs_sc_dsync_ops = {
660 .collect_data = nilfs_collect_file_data,
661 .collect_node = NULL,
662 .collect_bmap = NULL,
663 .write_data_binfo = nilfs_write_file_data_binfo,
664 .write_node_binfo = NULL,
665 };
666
667 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
668 struct list_head *listp,
669 size_t nlimit,
670 loff_t start, loff_t end)
671 {
672 struct address_space *mapping = inode->i_mapping;
673 struct pagevec pvec;
674 pgoff_t index = 0, last = ULONG_MAX;
675 size_t ndirties = 0;
676 int i;
677
678 if (unlikely(start != 0 || end != LLONG_MAX)) {
679 /*
680 * A valid range is given for sync-ing data pages. The
681 * range is rounded to per-page; extra dirty buffers
682 * may be included if blocksize < pagesize.
683 */
684 index = start >> PAGE_SHIFT;
685 last = end >> PAGE_SHIFT;
686 }
687 pagevec_init(&pvec, 0);
688 repeat:
689 if (unlikely(index > last) ||
690 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
691 min_t(pgoff_t, last - index,
692 PAGEVEC_SIZE - 1) + 1))
693 return ndirties;
694
695 for (i = 0; i < pagevec_count(&pvec); i++) {
696 struct buffer_head *bh, *head;
697 struct page *page = pvec.pages[i];
698
699 if (unlikely(page->index > last))
700 break;
701
702 if (mapping->host) {
703 lock_page(page);
704 if (!page_has_buffers(page))
705 create_empty_buffers(page,
706 1 << inode->i_blkbits, 0);
707 unlock_page(page);
708 }
709
710 bh = head = page_buffers(page);
711 do {
712 if (!buffer_dirty(bh))
713 continue;
714 get_bh(bh);
715 list_add_tail(&bh->b_assoc_buffers, listp);
716 ndirties++;
717 if (unlikely(ndirties >= nlimit)) {
718 pagevec_release(&pvec);
719 cond_resched();
720 return ndirties;
721 }
722 } while (bh = bh->b_this_page, bh != head);
723 }
724 pagevec_release(&pvec);
725 cond_resched();
726 goto repeat;
727 }
728
729 static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
730 struct list_head *listp)
731 {
732 struct nilfs_inode_info *ii = NILFS_I(inode);
733 struct address_space *mapping = &ii->i_btnode_cache;
734 struct pagevec pvec;
735 struct buffer_head *bh, *head;
736 unsigned int i;
737 pgoff_t index = 0;
738
739 pagevec_init(&pvec, 0);
740
741 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
742 PAGEVEC_SIZE)) {
743 for (i = 0; i < pagevec_count(&pvec); i++) {
744 bh = head = page_buffers(pvec.pages[i]);
745 do {
746 if (buffer_dirty(bh)) {
747 get_bh(bh);
748 list_add_tail(&bh->b_assoc_buffers,
749 listp);
750 }
751 bh = bh->b_this_page;
752 } while (bh != head);
753 }
754 pagevec_release(&pvec);
755 cond_resched();
756 }
757 }
758
759 static void nilfs_dispose_list(struct nilfs_sb_info *sbi,
760 struct list_head *head, int force)
761 {
762 struct nilfs_inode_info *ii, *n;
763 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
764 unsigned nv = 0;
765
766 while (!list_empty(head)) {
767 spin_lock(&sbi->s_inode_lock);
768 list_for_each_entry_safe(ii, n, head, i_dirty) {
769 list_del_init(&ii->i_dirty);
770 if (force) {
771 if (unlikely(ii->i_bh)) {
772 brelse(ii->i_bh);
773 ii->i_bh = NULL;
774 }
775 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
776 set_bit(NILFS_I_QUEUED, &ii->i_state);
777 list_add_tail(&ii->i_dirty,
778 &sbi->s_dirty_files);
779 continue;
780 }
781 ivec[nv++] = ii;
782 if (nv == SC_N_INODEVEC)
783 break;
784 }
785 spin_unlock(&sbi->s_inode_lock);
786
787 for (pii = ivec; nv > 0; pii++, nv--)
788 iput(&(*pii)->vfs_inode);
789 }
790 }
791
792 static int nilfs_test_metadata_dirty(struct nilfs_sb_info *sbi)
793 {
794 struct the_nilfs *nilfs = sbi->s_nilfs;
795 int ret = 0;
796
797 if (nilfs_mdt_fetch_dirty(sbi->s_ifile))
798 ret++;
799 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
800 ret++;
801 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
802 ret++;
803 if (ret || nilfs_doing_gc())
804 if (nilfs_mdt_fetch_dirty(nilfs_dat_inode(nilfs)))
805 ret++;
806 return ret;
807 }
808
809 static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
810 {
811 return list_empty(&sci->sc_dirty_files) &&
812 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
813 sci->sc_nfreesegs == 0 &&
814 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
815 }
816
817 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
818 {
819 struct nilfs_sb_info *sbi = sci->sc_sbi;
820 int ret = 0;
821
822 if (nilfs_test_metadata_dirty(sbi))
823 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
824
825 spin_lock(&sbi->s_inode_lock);
826 if (list_empty(&sbi->s_dirty_files) && nilfs_segctor_clean(sci))
827 ret++;
828
829 spin_unlock(&sbi->s_inode_lock);
830 return ret;
831 }
832
833 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
834 {
835 struct nilfs_sb_info *sbi = sci->sc_sbi;
836 struct the_nilfs *nilfs = sbi->s_nilfs;
837
838 nilfs_mdt_clear_dirty(sbi->s_ifile);
839 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
840 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
841 nilfs_mdt_clear_dirty(nilfs_dat_inode(nilfs));
842 }
843
844 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
845 {
846 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
847 struct buffer_head *bh_cp;
848 struct nilfs_checkpoint *raw_cp;
849 int err;
850
851 /* XXX: this interface will be changed */
852 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
853 &raw_cp, &bh_cp);
854 if (likely(!err)) {
855 /* The following code is duplicated with cpfile. But, it is
856 needed to collect the checkpoint even if it was not newly
857 created */
858 nilfs_mdt_mark_buffer_dirty(bh_cp);
859 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
860 nilfs_cpfile_put_checkpoint(
861 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
862 } else
863 WARN_ON(err == -EINVAL || err == -ENOENT);
864
865 return err;
866 }
867
868 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
869 {
870 struct nilfs_sb_info *sbi = sci->sc_sbi;
871 struct the_nilfs *nilfs = sbi->s_nilfs;
872 struct buffer_head *bh_cp;
873 struct nilfs_checkpoint *raw_cp;
874 int err;
875
876 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
877 &raw_cp, &bh_cp);
878 if (unlikely(err)) {
879 WARN_ON(err == -EINVAL || err == -ENOENT);
880 goto failed_ibh;
881 }
882 raw_cp->cp_snapshot_list.ssl_next = 0;
883 raw_cp->cp_snapshot_list.ssl_prev = 0;
884 raw_cp->cp_inodes_count =
885 cpu_to_le64(atomic_read(&sbi->s_inodes_count));
886 raw_cp->cp_blocks_count =
887 cpu_to_le64(atomic_read(&sbi->s_blocks_count));
888 raw_cp->cp_nblk_inc =
889 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
890 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
891 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
892
893 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
894 nilfs_checkpoint_clear_minor(raw_cp);
895 else
896 nilfs_checkpoint_set_minor(raw_cp);
897
898 nilfs_write_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode, 1);
899 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
900 return 0;
901
902 failed_ibh:
903 return err;
904 }
905
906 static void nilfs_fill_in_file_bmap(struct inode *ifile,
907 struct nilfs_inode_info *ii)
908
909 {
910 struct buffer_head *ibh;
911 struct nilfs_inode *raw_inode;
912
913 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
914 ibh = ii->i_bh;
915 BUG_ON(!ibh);
916 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
917 ibh);
918 nilfs_bmap_write(ii->i_bmap, raw_inode);
919 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
920 }
921 }
922
923 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci,
924 struct inode *ifile)
925 {
926 struct nilfs_inode_info *ii;
927
928 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
929 nilfs_fill_in_file_bmap(ifile, ii);
930 set_bit(NILFS_I_COLLECTED, &ii->i_state);
931 }
932 }
933
934 /*
935 * CRC calculation routines
936 */
937 static void nilfs_fill_in_super_root_crc(struct buffer_head *bh_sr, u32 seed)
938 {
939 struct nilfs_super_root *raw_sr =
940 (struct nilfs_super_root *)bh_sr->b_data;
941 u32 crc;
942
943 crc = crc32_le(seed,
944 (unsigned char *)raw_sr + sizeof(raw_sr->sr_sum),
945 NILFS_SR_BYTES - sizeof(raw_sr->sr_sum));
946 raw_sr->sr_sum = cpu_to_le32(crc);
947 }
948
949 static void nilfs_segctor_fill_in_checksums(struct nilfs_sc_info *sci,
950 u32 seed)
951 {
952 struct nilfs_segment_buffer *segbuf;
953
954 if (sci->sc_super_root)
955 nilfs_fill_in_super_root_crc(sci->sc_super_root, seed);
956
957 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
958 nilfs_segbuf_fill_in_segsum_crc(segbuf, seed);
959 nilfs_segbuf_fill_in_data_crc(segbuf, seed);
960 }
961 }
962
963 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
964 struct the_nilfs *nilfs)
965 {
966 struct buffer_head *bh_sr = sci->sc_super_root;
967 struct nilfs_super_root *raw_sr =
968 (struct nilfs_super_root *)bh_sr->b_data;
969 unsigned isz = nilfs->ns_inode_size;
970
971 raw_sr->sr_bytes = cpu_to_le16(NILFS_SR_BYTES);
972 raw_sr->sr_nongc_ctime
973 = cpu_to_le64(nilfs_doing_gc() ?
974 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
975 raw_sr->sr_flags = 0;
976
977 nilfs_mdt_write_inode_direct(
978 nilfs_dat_inode(nilfs), bh_sr, NILFS_SR_DAT_OFFSET(isz));
979 nilfs_mdt_write_inode_direct(
980 nilfs->ns_cpfile, bh_sr, NILFS_SR_CPFILE_OFFSET(isz));
981 nilfs_mdt_write_inode_direct(
982 nilfs->ns_sufile, bh_sr, NILFS_SR_SUFILE_OFFSET(isz));
983 }
984
985 static void nilfs_redirty_inodes(struct list_head *head)
986 {
987 struct nilfs_inode_info *ii;
988
989 list_for_each_entry(ii, head, i_dirty) {
990 if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
991 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
992 }
993 }
994
995 static void nilfs_drop_collected_inodes(struct list_head *head)
996 {
997 struct nilfs_inode_info *ii;
998
999 list_for_each_entry(ii, head, i_dirty) {
1000 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
1001 continue;
1002
1003 clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
1004 set_bit(NILFS_I_UPDATED, &ii->i_state);
1005 }
1006 }
1007
1008 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
1009 struct inode *inode,
1010 struct list_head *listp,
1011 int (*collect)(struct nilfs_sc_info *,
1012 struct buffer_head *,
1013 struct inode *))
1014 {
1015 struct buffer_head *bh, *n;
1016 int err = 0;
1017
1018 if (collect) {
1019 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
1020 list_del_init(&bh->b_assoc_buffers);
1021 err = collect(sci, bh, inode);
1022 brelse(bh);
1023 if (unlikely(err))
1024 goto dispose_buffers;
1025 }
1026 return 0;
1027 }
1028
1029 dispose_buffers:
1030 while (!list_empty(listp)) {
1031 bh = list_entry(listp->next, struct buffer_head,
1032 b_assoc_buffers);
1033 list_del_init(&bh->b_assoc_buffers);
1034 brelse(bh);
1035 }
1036 return err;
1037 }
1038
1039 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
1040 {
1041 /* Remaining number of blocks within segment buffer */
1042 return sci->sc_segbuf_nblocks -
1043 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
1044 }
1045
1046 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
1047 struct inode *inode,
1048 struct nilfs_sc_operations *sc_ops)
1049 {
1050 LIST_HEAD(data_buffers);
1051 LIST_HEAD(node_buffers);
1052 int err;
1053
1054 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1055 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1056
1057 n = nilfs_lookup_dirty_data_buffers(
1058 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
1059 if (n > rest) {
1060 err = nilfs_segctor_apply_buffers(
1061 sci, inode, &data_buffers,
1062 sc_ops->collect_data);
1063 BUG_ON(!err); /* always receive -E2BIG or true error */
1064 goto break_or_fail;
1065 }
1066 }
1067 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
1068
1069 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1070 err = nilfs_segctor_apply_buffers(
1071 sci, inode, &data_buffers, sc_ops->collect_data);
1072 if (unlikely(err)) {
1073 /* dispose node list */
1074 nilfs_segctor_apply_buffers(
1075 sci, inode, &node_buffers, NULL);
1076 goto break_or_fail;
1077 }
1078 sci->sc_stage.flags |= NILFS_CF_NODE;
1079 }
1080 /* Collect node */
1081 err = nilfs_segctor_apply_buffers(
1082 sci, inode, &node_buffers, sc_ops->collect_node);
1083 if (unlikely(err))
1084 goto break_or_fail;
1085
1086 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1087 err = nilfs_segctor_apply_buffers(
1088 sci, inode, &node_buffers, sc_ops->collect_bmap);
1089 if (unlikely(err))
1090 goto break_or_fail;
1091
1092 nilfs_segctor_end_finfo(sci, inode);
1093 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1094
1095 break_or_fail:
1096 return err;
1097 }
1098
1099 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1100 struct inode *inode)
1101 {
1102 LIST_HEAD(data_buffers);
1103 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1104 int err;
1105
1106 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1107 sci->sc_dsync_start,
1108 sci->sc_dsync_end);
1109
1110 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1111 nilfs_collect_file_data);
1112 if (!err) {
1113 nilfs_segctor_end_finfo(sci, inode);
1114 BUG_ON(n > rest);
1115 /* always receive -E2BIG or true error if n > rest */
1116 }
1117 return err;
1118 }
1119
1120 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1121 {
1122 struct nilfs_sb_info *sbi = sci->sc_sbi;
1123 struct the_nilfs *nilfs = sbi->s_nilfs;
1124 struct list_head *head;
1125 struct nilfs_inode_info *ii;
1126 size_t ndone;
1127 int err = 0;
1128
1129 switch (sci->sc_stage.scnt) {
1130 case NILFS_ST_INIT:
1131 /* Pre-processes */
1132 sci->sc_stage.flags = 0;
1133
1134 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1135 sci->sc_nblk_inc = 0;
1136 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1137 if (mode == SC_LSEG_DSYNC) {
1138 sci->sc_stage.scnt = NILFS_ST_DSYNC;
1139 goto dsync_mode;
1140 }
1141 }
1142
1143 sci->sc_stage.dirty_file_ptr = NULL;
1144 sci->sc_stage.gc_inode_ptr = NULL;
1145 if (mode == SC_FLUSH_DAT) {
1146 sci->sc_stage.scnt = NILFS_ST_DAT;
1147 goto dat_stage;
1148 }
1149 sci->sc_stage.scnt++; /* Fall through */
1150 case NILFS_ST_GC:
1151 if (nilfs_doing_gc()) {
1152 head = &sci->sc_gc_inodes;
1153 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1154 head, i_dirty);
1155 list_for_each_entry_continue(ii, head, i_dirty) {
1156 err = nilfs_segctor_scan_file(
1157 sci, &ii->vfs_inode,
1158 &nilfs_sc_file_ops);
1159 if (unlikely(err)) {
1160 sci->sc_stage.gc_inode_ptr = list_entry(
1161 ii->i_dirty.prev,
1162 struct nilfs_inode_info,
1163 i_dirty);
1164 goto break_or_fail;
1165 }
1166 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1167 }
1168 sci->sc_stage.gc_inode_ptr = NULL;
1169 }
1170 sci->sc_stage.scnt++; /* Fall through */
1171 case NILFS_ST_FILE:
1172 head = &sci->sc_dirty_files;
1173 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1174 i_dirty);
1175 list_for_each_entry_continue(ii, head, i_dirty) {
1176 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1177
1178 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1179 &nilfs_sc_file_ops);
1180 if (unlikely(err)) {
1181 sci->sc_stage.dirty_file_ptr =
1182 list_entry(ii->i_dirty.prev,
1183 struct nilfs_inode_info,
1184 i_dirty);
1185 goto break_or_fail;
1186 }
1187 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1188 /* XXX: required ? */
1189 }
1190 sci->sc_stage.dirty_file_ptr = NULL;
1191 if (mode == SC_FLUSH_FILE) {
1192 sci->sc_stage.scnt = NILFS_ST_DONE;
1193 return 0;
1194 }
1195 sci->sc_stage.scnt++;
1196 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1197 /* Fall through */
1198 case NILFS_ST_IFILE:
1199 err = nilfs_segctor_scan_file(sci, sbi->s_ifile,
1200 &nilfs_sc_file_ops);
1201 if (unlikely(err))
1202 break;
1203 sci->sc_stage.scnt++;
1204 /* Creating a checkpoint */
1205 err = nilfs_segctor_create_checkpoint(sci);
1206 if (unlikely(err))
1207 break;
1208 /* Fall through */
1209 case NILFS_ST_CPFILE:
1210 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1211 &nilfs_sc_file_ops);
1212 if (unlikely(err))
1213 break;
1214 sci->sc_stage.scnt++; /* Fall through */
1215 case NILFS_ST_SUFILE:
1216 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1217 sci->sc_nfreesegs, &ndone);
1218 if (unlikely(err)) {
1219 nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1220 sci->sc_freesegs, ndone,
1221 NULL);
1222 break;
1223 }
1224 sci->sc_stage.flags |= NILFS_CF_SUFREED;
1225
1226 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1227 &nilfs_sc_file_ops);
1228 if (unlikely(err))
1229 break;
1230 sci->sc_stage.scnt++; /* Fall through */
1231 case NILFS_ST_DAT:
1232 dat_stage:
1233 err = nilfs_segctor_scan_file(sci, nilfs_dat_inode(nilfs),
1234 &nilfs_sc_dat_ops);
1235 if (unlikely(err))
1236 break;
1237 if (mode == SC_FLUSH_DAT) {
1238 sci->sc_stage.scnt = NILFS_ST_DONE;
1239 return 0;
1240 }
1241 sci->sc_stage.scnt++; /* Fall through */
1242 case NILFS_ST_SR:
1243 if (mode == SC_LSEG_SR) {
1244 /* Appending a super root */
1245 err = nilfs_segctor_add_super_root(sci);
1246 if (unlikely(err))
1247 break;
1248 }
1249 /* End of a logical segment */
1250 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1251 sci->sc_stage.scnt = NILFS_ST_DONE;
1252 return 0;
1253 case NILFS_ST_DSYNC:
1254 dsync_mode:
1255 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1256 ii = sci->sc_dsync_inode;
1257 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1258 break;
1259
1260 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1261 if (unlikely(err))
1262 break;
1263 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1264 sci->sc_stage.scnt = NILFS_ST_DONE;
1265 return 0;
1266 case NILFS_ST_DONE:
1267 return 0;
1268 default:
1269 BUG();
1270 }
1271
1272 break_or_fail:
1273 return err;
1274 }
1275
1276 static int nilfs_touch_segusage(struct inode *sufile, __u64 segnum)
1277 {
1278 struct buffer_head *bh_su;
1279 struct nilfs_segment_usage *raw_su;
1280 int err;
1281
1282 err = nilfs_sufile_get_segment_usage(sufile, segnum, &raw_su, &bh_su);
1283 if (unlikely(err))
1284 return err;
1285 nilfs_mdt_mark_buffer_dirty(bh_su);
1286 nilfs_mdt_mark_dirty(sufile);
1287 nilfs_sufile_put_segment_usage(sufile, segnum, bh_su);
1288 return 0;
1289 }
1290
1291 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1292 struct the_nilfs *nilfs)
1293 {
1294 struct nilfs_segment_buffer *segbuf, *n;
1295 __u64 nextnum;
1296 int err;
1297
1298 if (list_empty(&sci->sc_segbufs)) {
1299 segbuf = nilfs_segbuf_new(sci->sc_super);
1300 if (unlikely(!segbuf))
1301 return -ENOMEM;
1302 list_add(&segbuf->sb_list, &sci->sc_segbufs);
1303 } else
1304 segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1305
1306 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, nilfs->ns_pseg_offset,
1307 nilfs);
1308
1309 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1310 nilfs_shift_to_next_segment(nilfs);
1311 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1312 }
1313 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1314
1315 err = nilfs_touch_segusage(nilfs->ns_sufile, segbuf->sb_segnum);
1316 if (unlikely(err))
1317 return err;
1318
1319 if (nilfs->ns_segnum == nilfs->ns_nextnum) {
1320 /* Start from the head of a new full segment */
1321 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1322 if (unlikely(err))
1323 return err;
1324 } else
1325 nextnum = nilfs->ns_nextnum;
1326
1327 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1328 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1329
1330 /* truncating segment buffers */
1331 list_for_each_entry_safe_continue(segbuf, n, &sci->sc_segbufs,
1332 sb_list) {
1333 list_del_init(&segbuf->sb_list);
1334 nilfs_segbuf_free(segbuf);
1335 }
1336 return 0;
1337 }
1338
1339 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1340 struct the_nilfs *nilfs, int nadd)
1341 {
1342 struct nilfs_segment_buffer *segbuf, *prev, *n;
1343 struct inode *sufile = nilfs->ns_sufile;
1344 __u64 nextnextnum;
1345 LIST_HEAD(list);
1346 int err, ret, i;
1347
1348 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1349 /*
1350 * Since the segment specified with nextnum might be allocated during
1351 * the previous construction, the buffer including its segusage may
1352 * not be dirty. The following call ensures that the buffer is dirty
1353 * and will pin the buffer on memory until the sufile is written.
1354 */
1355 err = nilfs_touch_segusage(sufile, prev->sb_nextnum);
1356 if (unlikely(err))
1357 return err;
1358
1359 for (i = 0; i < nadd; i++) {
1360 /* extend segment info */
1361 err = -ENOMEM;
1362 segbuf = nilfs_segbuf_new(sci->sc_super);
1363 if (unlikely(!segbuf))
1364 goto failed;
1365
1366 /* map this buffer to region of segment on-disk */
1367 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1368 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1369
1370 /* allocate the next next full segment */
1371 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1372 if (unlikely(err))
1373 goto failed_segbuf;
1374
1375 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1376 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1377
1378 list_add_tail(&segbuf->sb_list, &list);
1379 prev = segbuf;
1380 }
1381 list_splice(&list, sci->sc_segbufs.prev);
1382 return 0;
1383
1384 failed_segbuf:
1385 nilfs_segbuf_free(segbuf);
1386 failed:
1387 list_for_each_entry_safe(segbuf, n, &list, sb_list) {
1388 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1389 WARN_ON(ret); /* never fails */
1390 list_del_init(&segbuf->sb_list);
1391 nilfs_segbuf_free(segbuf);
1392 }
1393 return err;
1394 }
1395
1396 static void nilfs_segctor_free_incomplete_segments(struct nilfs_sc_info *sci,
1397 struct the_nilfs *nilfs)
1398 {
1399 struct nilfs_segment_buffer *segbuf;
1400 int ret, done = 0;
1401
1402 segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1403 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1404 ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
1405 WARN_ON(ret); /* never fails */
1406 }
1407 if (segbuf->sb_io_error) {
1408 /* Case 1: The first segment failed */
1409 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1410 /* Case 1a: Partial segment appended into an existing
1411 segment */
1412 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1413 segbuf->sb_fseg_end);
1414 else /* Case 1b: New full segment */
1415 set_nilfs_discontinued(nilfs);
1416 done++;
1417 }
1418
1419 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1420 ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
1421 WARN_ON(ret); /* never fails */
1422 if (!done && segbuf->sb_io_error) {
1423 if (segbuf->sb_segnum != nilfs->ns_nextnum)
1424 /* Case 2: extended segment (!= next) failed */
1425 nilfs_sufile_set_error(nilfs->ns_sufile,
1426 segbuf->sb_segnum);
1427 done++;
1428 }
1429 }
1430 }
1431
1432 static void nilfs_segctor_clear_segment_buffers(struct nilfs_sc_info *sci)
1433 {
1434 struct nilfs_segment_buffer *segbuf;
1435
1436 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list)
1437 nilfs_segbuf_clear(segbuf);
1438 sci->sc_super_root = NULL;
1439 }
1440
1441 static void nilfs_segctor_destroy_segment_buffers(struct nilfs_sc_info *sci)
1442 {
1443 struct nilfs_segment_buffer *segbuf;
1444
1445 while (!list_empty(&sci->sc_segbufs)) {
1446 segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1447 list_del_init(&segbuf->sb_list);
1448 nilfs_segbuf_free(segbuf);
1449 }
1450 /* sci->sc_curseg = NULL; */
1451 }
1452
1453 static void nilfs_segctor_end_construction(struct nilfs_sc_info *sci,
1454 struct the_nilfs *nilfs, int err)
1455 {
1456 if (unlikely(err)) {
1457 nilfs_segctor_free_incomplete_segments(sci, nilfs);
1458 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1459 int ret;
1460
1461 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1462 sci->sc_freesegs,
1463 sci->sc_nfreesegs,
1464 NULL);
1465 WARN_ON(ret); /* do not happen */
1466 }
1467 }
1468 nilfs_segctor_clear_segment_buffers(sci);
1469 }
1470
1471 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1472 struct inode *sufile)
1473 {
1474 struct nilfs_segment_buffer *segbuf;
1475 struct buffer_head *bh_su;
1476 struct nilfs_segment_usage *raw_su;
1477 unsigned long live_blocks;
1478 int ret;
1479
1480 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1481 ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
1482 &raw_su, &bh_su);
1483 WARN_ON(ret); /* always succeed because bh_su is dirty */
1484 live_blocks = segbuf->sb_sum.nblocks +
1485 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1486 raw_su->su_lastmod = cpu_to_le64(sci->sc_seg_ctime);
1487 raw_su->su_nblocks = cpu_to_le32(live_blocks);
1488 nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum,
1489 bh_su);
1490 }
1491 }
1492
1493 static void nilfs_segctor_cancel_segusage(struct nilfs_sc_info *sci,
1494 struct inode *sufile)
1495 {
1496 struct nilfs_segment_buffer *segbuf;
1497 struct buffer_head *bh_su;
1498 struct nilfs_segment_usage *raw_su;
1499 int ret;
1500
1501 segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1502 ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
1503 &raw_su, &bh_su);
1504 WARN_ON(ret); /* always succeed because bh_su is dirty */
1505 raw_su->su_nblocks = cpu_to_le32(segbuf->sb_pseg_start -
1506 segbuf->sb_fseg_start);
1507 nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum, bh_su);
1508
1509 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1510 ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
1511 &raw_su, &bh_su);
1512 WARN_ON(ret); /* always succeed */
1513 raw_su->su_nblocks = 0;
1514 nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum,
1515 bh_su);
1516 }
1517 }
1518
1519 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1520 struct nilfs_segment_buffer *last,
1521 struct inode *sufile)
1522 {
1523 struct nilfs_segment_buffer *segbuf = last, *n;
1524 int ret;
1525
1526 list_for_each_entry_safe_continue(segbuf, n, &sci->sc_segbufs,
1527 sb_list) {
1528 list_del_init(&segbuf->sb_list);
1529 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1530 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1531 WARN_ON(ret);
1532 nilfs_segbuf_free(segbuf);
1533 }
1534 }
1535
1536
1537 static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1538 struct the_nilfs *nilfs, int mode)
1539 {
1540 struct nilfs_cstage prev_stage = sci->sc_stage;
1541 int err, nadd = 1;
1542
1543 /* Collection retry loop */
1544 for (;;) {
1545 sci->sc_super_root = NULL;
1546 sci->sc_nblk_this_inc = 0;
1547 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1548
1549 err = nilfs_segctor_reset_segment_buffer(sci);
1550 if (unlikely(err))
1551 goto failed;
1552
1553 err = nilfs_segctor_collect_blocks(sci, mode);
1554 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1555 if (!err)
1556 break;
1557
1558 if (unlikely(err != -E2BIG))
1559 goto failed;
1560
1561 /* The current segment is filled up */
1562 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
1563 break;
1564
1565 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1566 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1567 sci->sc_freesegs,
1568 sci->sc_nfreesegs,
1569 NULL);
1570 WARN_ON(err); /* do not happen */
1571 }
1572 nilfs_segctor_clear_segment_buffers(sci);
1573
1574 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1575 if (unlikely(err))
1576 return err;
1577
1578 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1579 sci->sc_stage = prev_stage;
1580 }
1581 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1582 return 0;
1583
1584 failed:
1585 return err;
1586 }
1587
1588 static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1589 struct buffer_head *new_bh)
1590 {
1591 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1592
1593 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1594 /* The caller must release old_bh */
1595 }
1596
1597 static int
1598 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1599 struct nilfs_segment_buffer *segbuf,
1600 int mode)
1601 {
1602 struct inode *inode = NULL;
1603 sector_t blocknr;
1604 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1605 unsigned long nblocks = 0, ndatablk = 0;
1606 struct nilfs_sc_operations *sc_op = NULL;
1607 struct nilfs_segsum_pointer ssp;
1608 struct nilfs_finfo *finfo = NULL;
1609 union nilfs_binfo binfo;
1610 struct buffer_head *bh, *bh_org;
1611 ino_t ino = 0;
1612 int err = 0;
1613
1614 if (!nfinfo)
1615 goto out;
1616
1617 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1618 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1619 ssp.offset = sizeof(struct nilfs_segment_summary);
1620
1621 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1622 if (bh == sci->sc_super_root)
1623 break;
1624 if (!finfo) {
1625 finfo = nilfs_segctor_map_segsum_entry(
1626 sci, &ssp, sizeof(*finfo));
1627 ino = le64_to_cpu(finfo->fi_ino);
1628 nblocks = le32_to_cpu(finfo->fi_nblocks);
1629 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1630
1631 if (buffer_nilfs_node(bh))
1632 inode = NILFS_BTNC_I(bh->b_page->mapping);
1633 else
1634 inode = NILFS_AS_I(bh->b_page->mapping);
1635
1636 if (mode == SC_LSEG_DSYNC)
1637 sc_op = &nilfs_sc_dsync_ops;
1638 else if (ino == NILFS_DAT_INO)
1639 sc_op = &nilfs_sc_dat_ops;
1640 else /* file blocks */
1641 sc_op = &nilfs_sc_file_ops;
1642 }
1643 bh_org = bh;
1644 get_bh(bh_org);
1645 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1646 &binfo);
1647 if (bh != bh_org)
1648 nilfs_list_replace_buffer(bh_org, bh);
1649 brelse(bh_org);
1650 if (unlikely(err))
1651 goto failed_bmap;
1652
1653 if (ndatablk > 0)
1654 sc_op->write_data_binfo(sci, &ssp, &binfo);
1655 else
1656 sc_op->write_node_binfo(sci, &ssp, &binfo);
1657
1658 blocknr++;
1659 if (--nblocks == 0) {
1660 finfo = NULL;
1661 if (--nfinfo == 0)
1662 break;
1663 } else if (ndatablk > 0)
1664 ndatablk--;
1665 }
1666 out:
1667 return 0;
1668
1669 failed_bmap:
1670 err = nilfs_handle_bmap_error(err, __func__, inode, sci->sc_super);
1671 return err;
1672 }
1673
1674 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1675 {
1676 struct nilfs_segment_buffer *segbuf;
1677 int err;
1678
1679 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1680 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1681 if (unlikely(err))
1682 return err;
1683 nilfs_segbuf_fill_in_segsum(segbuf);
1684 }
1685 return 0;
1686 }
1687
1688 static int
1689 nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out)
1690 {
1691 struct page *clone_page;
1692 struct buffer_head *bh, *head, *bh2;
1693 void *kaddr;
1694
1695 bh = head = page_buffers(page);
1696
1697 clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0);
1698 if (unlikely(!clone_page))
1699 return -ENOMEM;
1700
1701 bh2 = page_buffers(clone_page);
1702 kaddr = kmap_atomic(page, KM_USER0);
1703 do {
1704 if (list_empty(&bh->b_assoc_buffers))
1705 continue;
1706 get_bh(bh2);
1707 page_cache_get(clone_page); /* for each bh */
1708 memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size);
1709 bh2->b_blocknr = bh->b_blocknr;
1710 list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers);
1711 list_add_tail(&bh->b_assoc_buffers, out);
1712 } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head);
1713 kunmap_atomic(kaddr, KM_USER0);
1714
1715 if (!TestSetPageWriteback(clone_page))
1716 inc_zone_page_state(clone_page, NR_WRITEBACK);
1717 unlock_page(clone_page);
1718
1719 return 0;
1720 }
1721
1722 static int nilfs_test_page_to_be_frozen(struct page *page)
1723 {
1724 struct address_space *mapping = page->mapping;
1725
1726 if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode))
1727 return 0;
1728
1729 if (page_mapped(page)) {
1730 ClearPageChecked(page);
1731 return 1;
1732 }
1733 return PageChecked(page);
1734 }
1735
1736 static int nilfs_begin_page_io(struct page *page, struct list_head *out)
1737 {
1738 if (!page || PageWriteback(page))
1739 /* For split b-tree node pages, this function may be called
1740 twice. We ignore the 2nd or later calls by this check. */
1741 return 0;
1742
1743 lock_page(page);
1744 clear_page_dirty_for_io(page);
1745 set_page_writeback(page);
1746 unlock_page(page);
1747
1748 if (nilfs_test_page_to_be_frozen(page)) {
1749 int err = nilfs_copy_replace_page_buffers(page, out);
1750 if (unlikely(err))
1751 return err;
1752 }
1753 return 0;
1754 }
1755
1756 static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
1757 struct page **failed_page)
1758 {
1759 struct nilfs_segment_buffer *segbuf;
1760 struct page *bd_page = NULL, *fs_page = NULL;
1761 struct list_head *list = &sci->sc_copied_buffers;
1762 int err;
1763
1764 *failed_page = NULL;
1765 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1766 struct buffer_head *bh;
1767
1768 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1769 b_assoc_buffers) {
1770 if (bh->b_page != bd_page) {
1771 if (bd_page) {
1772 lock_page(bd_page);
1773 clear_page_dirty_for_io(bd_page);
1774 set_page_writeback(bd_page);
1775 unlock_page(bd_page);
1776 }
1777 bd_page = bh->b_page;
1778 }
1779 }
1780
1781 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1782 b_assoc_buffers) {
1783 if (bh == sci->sc_super_root) {
1784 if (bh->b_page != bd_page) {
1785 lock_page(bd_page);
1786 clear_page_dirty_for_io(bd_page);
1787 set_page_writeback(bd_page);
1788 unlock_page(bd_page);
1789 bd_page = bh->b_page;
1790 }
1791 break;
1792 }
1793 if (bh->b_page != fs_page) {
1794 err = nilfs_begin_page_io(fs_page, list);
1795 if (unlikely(err)) {
1796 *failed_page = fs_page;
1797 goto out;
1798 }
1799 fs_page = bh->b_page;
1800 }
1801 }
1802 }
1803 if (bd_page) {
1804 lock_page(bd_page);
1805 clear_page_dirty_for_io(bd_page);
1806 set_page_writeback(bd_page);
1807 unlock_page(bd_page);
1808 }
1809 err = nilfs_begin_page_io(fs_page, list);
1810 if (unlikely(err))
1811 *failed_page = fs_page;
1812 out:
1813 return err;
1814 }
1815
1816 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1817 struct backing_dev_info *bdi)
1818 {
1819 struct nilfs_segment_buffer *segbuf;
1820 struct nilfs_write_info wi;
1821 int err, res;
1822
1823 wi.sb = sci->sc_super;
1824 wi.bh_sr = sci->sc_super_root;
1825 wi.bdi = bdi;
1826
1827 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1828 nilfs_segbuf_prepare_write(segbuf, &wi);
1829 err = nilfs_segbuf_write(segbuf, &wi);
1830
1831 res = nilfs_segbuf_wait(segbuf, &wi);
1832 err = err ? : res;
1833 if (err)
1834 return err;
1835 }
1836 return 0;
1837 }
1838
1839 static void __nilfs_end_page_io(struct page *page, int err)
1840 {
1841 if (!err) {
1842 if (!nilfs_page_buffers_clean(page))
1843 __set_page_dirty_nobuffers(page);
1844 ClearPageError(page);
1845 } else {
1846 __set_page_dirty_nobuffers(page);
1847 SetPageError(page);
1848 }
1849
1850 if (buffer_nilfs_allocated(page_buffers(page))) {
1851 if (TestClearPageWriteback(page))
1852 dec_zone_page_state(page, NR_WRITEBACK);
1853 } else
1854 end_page_writeback(page);
1855 }
1856
1857 static void nilfs_end_page_io(struct page *page, int err)
1858 {
1859 if (!page)
1860 return;
1861
1862 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page))
1863 /*
1864 * For b-tree node pages, this function may be called twice
1865 * or more because they might be split in a segment.
1866 */
1867 return;
1868
1869 __nilfs_end_page_io(page, err);
1870 }
1871
1872 static void nilfs_clear_copied_buffers(struct list_head *list, int err)
1873 {
1874 struct buffer_head *bh, *head;
1875 struct page *page;
1876
1877 while (!list_empty(list)) {
1878 bh = list_entry(list->next, struct buffer_head,
1879 b_assoc_buffers);
1880 page = bh->b_page;
1881 page_cache_get(page);
1882 head = bh = page_buffers(page);
1883 do {
1884 if (!list_empty(&bh->b_assoc_buffers)) {
1885 list_del_init(&bh->b_assoc_buffers);
1886 if (!err) {
1887 set_buffer_uptodate(bh);
1888 clear_buffer_dirty(bh);
1889 clear_buffer_nilfs_volatile(bh);
1890 }
1891 brelse(bh); /* for b_assoc_buffers */
1892 }
1893 } while ((bh = bh->b_this_page) != head);
1894
1895 __nilfs_end_page_io(page, err);
1896 page_cache_release(page);
1897 }
1898 }
1899
1900 static void nilfs_segctor_abort_write(struct nilfs_sc_info *sci,
1901 struct page *failed_page, int err)
1902 {
1903 struct nilfs_segment_buffer *segbuf;
1904 struct page *bd_page = NULL, *fs_page = NULL;
1905
1906 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1907 struct buffer_head *bh;
1908
1909 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1910 b_assoc_buffers) {
1911 if (bh->b_page != bd_page) {
1912 if (bd_page)
1913 end_page_writeback(bd_page);
1914 bd_page = bh->b_page;
1915 }
1916 }
1917
1918 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1919 b_assoc_buffers) {
1920 if (bh == sci->sc_super_root) {
1921 if (bh->b_page != bd_page) {
1922 end_page_writeback(bd_page);
1923 bd_page = bh->b_page;
1924 }
1925 break;
1926 }
1927 if (bh->b_page != fs_page) {
1928 nilfs_end_page_io(fs_page, err);
1929 if (fs_page && fs_page == failed_page)
1930 goto done;
1931 fs_page = bh->b_page;
1932 }
1933 }
1934 }
1935 if (bd_page)
1936 end_page_writeback(bd_page);
1937
1938 nilfs_end_page_io(fs_page, err);
1939 done:
1940 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err);
1941 }
1942
1943 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1944 struct nilfs_segment_buffer *segbuf)
1945 {
1946 nilfs->ns_segnum = segbuf->sb_segnum;
1947 nilfs->ns_nextnum = segbuf->sb_nextnum;
1948 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1949 + segbuf->sb_sum.nblocks;
1950 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1951 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1952 }
1953
1954 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1955 {
1956 struct nilfs_segment_buffer *segbuf;
1957 struct page *bd_page = NULL, *fs_page = NULL;
1958 struct nilfs_sb_info *sbi = sci->sc_sbi;
1959 struct the_nilfs *nilfs = sbi->s_nilfs;
1960 int update_sr = (sci->sc_super_root != NULL);
1961
1962 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1963 struct buffer_head *bh;
1964
1965 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1966 b_assoc_buffers) {
1967 set_buffer_uptodate(bh);
1968 clear_buffer_dirty(bh);
1969 if (bh->b_page != bd_page) {
1970 if (bd_page)
1971 end_page_writeback(bd_page);
1972 bd_page = bh->b_page;
1973 }
1974 }
1975 /*
1976 * We assume that the buffers which belong to the same page
1977 * continue over the buffer list.
1978 * Under this assumption, the last BHs of pages is
1979 * identifiable by the discontinuity of bh->b_page
1980 * (page != fs_page).
1981 *
1982 * For B-tree node blocks, however, this assumption is not
1983 * guaranteed. The cleanup code of B-tree node pages needs
1984 * special care.
1985 */
1986 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1987 b_assoc_buffers) {
1988 set_buffer_uptodate(bh);
1989 clear_buffer_dirty(bh);
1990 clear_buffer_nilfs_volatile(bh);
1991 if (bh == sci->sc_super_root) {
1992 if (bh->b_page != bd_page) {
1993 end_page_writeback(bd_page);
1994 bd_page = bh->b_page;
1995 }
1996 break;
1997 }
1998 if (bh->b_page != fs_page) {
1999 nilfs_end_page_io(fs_page, 0);
2000 fs_page = bh->b_page;
2001 }
2002 }
2003
2004 if (!NILFS_SEG_SIMPLEX(&segbuf->sb_sum)) {
2005 if (NILFS_SEG_LOGBGN(&segbuf->sb_sum)) {
2006 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
2007 sci->sc_lseg_stime = jiffies;
2008 }
2009 if (NILFS_SEG_LOGEND(&segbuf->sb_sum))
2010 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
2011 }
2012 }
2013 /*
2014 * Since pages may continue over multiple segment buffers,
2015 * end of the last page must be checked outside of the loop.
2016 */
2017 if (bd_page)
2018 end_page_writeback(bd_page);
2019
2020 nilfs_end_page_io(fs_page, 0);
2021
2022 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, 0);
2023
2024 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
2025
2026 if (nilfs_doing_gc()) {
2027 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
2028 if (update_sr)
2029 nilfs_commit_gcdat_inode(nilfs);
2030 } else
2031 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
2032
2033 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
2034
2035 segbuf = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
2036 nilfs_set_next_segment(nilfs, segbuf);
2037
2038 if (update_sr) {
2039 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
2040 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
2041 sbi->s_super->s_dirt = 1;
2042
2043 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
2044 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2045 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
2046 } else
2047 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
2048 }
2049
2050 static int nilfs_segctor_check_in_files(struct nilfs_sc_info *sci,
2051 struct nilfs_sb_info *sbi)
2052 {
2053 struct nilfs_inode_info *ii, *n;
2054 __u64 cno = sbi->s_nilfs->ns_cno;
2055
2056 spin_lock(&sbi->s_inode_lock);
2057 retry:
2058 list_for_each_entry_safe(ii, n, &sbi->s_dirty_files, i_dirty) {
2059 if (!ii->i_bh) {
2060 struct buffer_head *ibh;
2061 int err;
2062
2063 spin_unlock(&sbi->s_inode_lock);
2064 err = nilfs_ifile_get_inode_block(
2065 sbi->s_ifile, ii->vfs_inode.i_ino, &ibh);
2066 if (unlikely(err)) {
2067 nilfs_warning(sbi->s_super, __func__,
2068 "failed to get inode block.\n");
2069 return err;
2070 }
2071 nilfs_mdt_mark_buffer_dirty(ibh);
2072 nilfs_mdt_mark_dirty(sbi->s_ifile);
2073 spin_lock(&sbi->s_inode_lock);
2074 if (likely(!ii->i_bh))
2075 ii->i_bh = ibh;
2076 else
2077 brelse(ibh);
2078 goto retry;
2079 }
2080 ii->i_cno = cno;
2081
2082 clear_bit(NILFS_I_QUEUED, &ii->i_state);
2083 set_bit(NILFS_I_BUSY, &ii->i_state);
2084 list_del(&ii->i_dirty);
2085 list_add_tail(&ii->i_dirty, &sci->sc_dirty_files);
2086 }
2087 spin_unlock(&sbi->s_inode_lock);
2088
2089 NILFS_I(sbi->s_ifile)->i_cno = cno;
2090
2091 return 0;
2092 }
2093
2094 static void nilfs_segctor_check_out_files(struct nilfs_sc_info *sci,
2095 struct nilfs_sb_info *sbi)
2096 {
2097 struct nilfs_transaction_info *ti = current->journal_info;
2098 struct nilfs_inode_info *ii, *n;
2099 __u64 cno = sbi->s_nilfs->ns_cno;
2100
2101 spin_lock(&sbi->s_inode_lock);
2102 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
2103 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
2104 test_bit(NILFS_I_DIRTY, &ii->i_state)) {
2105 /* The current checkpoint number (=nilfs->ns_cno) is
2106 changed between check-in and check-out only if the
2107 super root is written out. So, we can update i_cno
2108 for the inodes that remain in the dirty list. */
2109 ii->i_cno = cno;
2110 continue;
2111 }
2112 clear_bit(NILFS_I_BUSY, &ii->i_state);
2113 brelse(ii->i_bh);
2114 ii->i_bh = NULL;
2115 list_del(&ii->i_dirty);
2116 list_add_tail(&ii->i_dirty, &ti->ti_garbage);
2117 }
2118 spin_unlock(&sbi->s_inode_lock);
2119 }
2120
2121 /*
2122 * Main procedure of segment constructor
2123 */
2124 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2125 {
2126 struct nilfs_sb_info *sbi = sci->sc_sbi;
2127 struct the_nilfs *nilfs = sbi->s_nilfs;
2128 struct page *failed_page;
2129 int err, has_sr = 0;
2130
2131 sci->sc_stage.scnt = NILFS_ST_INIT;
2132
2133 err = nilfs_segctor_check_in_files(sci, sbi);
2134 if (unlikely(err))
2135 goto out;
2136
2137 if (nilfs_test_metadata_dirty(sbi))
2138 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2139
2140 if (nilfs_segctor_clean(sci))
2141 goto out;
2142
2143 do {
2144 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2145
2146 err = nilfs_segctor_begin_construction(sci, nilfs);
2147 if (unlikely(err))
2148 goto out;
2149
2150 /* Update time stamp */
2151 sci->sc_seg_ctime = get_seconds();
2152
2153 err = nilfs_segctor_collect(sci, nilfs, mode);
2154 if (unlikely(err))
2155 goto failed;
2156
2157 has_sr = (sci->sc_super_root != NULL);
2158
2159 /* Avoid empty segment */
2160 if (sci->sc_stage.scnt == NILFS_ST_DONE &&
2161 NILFS_SEG_EMPTY(&sci->sc_curseg->sb_sum)) {
2162 nilfs_segctor_end_construction(sci, nilfs, 1);
2163 goto out;
2164 }
2165
2166 err = nilfs_segctor_assign(sci, mode);
2167 if (unlikely(err))
2168 goto failed;
2169
2170 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2171 nilfs_segctor_fill_in_file_bmap(sci, sbi->s_ifile);
2172
2173 if (has_sr) {
2174 err = nilfs_segctor_fill_in_checkpoint(sci);
2175 if (unlikely(err))
2176 goto failed_to_make_up;
2177
2178 nilfs_segctor_fill_in_super_root(sci, nilfs);
2179 }
2180 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2181
2182 /* Write partial segments */
2183 err = nilfs_segctor_prepare_write(sci, &failed_page);
2184 if (unlikely(err))
2185 goto failed_to_write;
2186
2187 nilfs_segctor_fill_in_checksums(sci, nilfs->ns_crc_seed);
2188
2189 err = nilfs_segctor_write(sci, nilfs->ns_bdi);
2190 if (unlikely(err))
2191 goto failed_to_write;
2192
2193 nilfs_segctor_complete_write(sci);
2194
2195 /* Commit segments */
2196 if (has_sr)
2197 nilfs_segctor_clear_metadata_dirty(sci);
2198
2199 nilfs_segctor_end_construction(sci, nilfs, 0);
2200
2201 } while (sci->sc_stage.scnt != NILFS_ST_DONE);
2202
2203 out:
2204 nilfs_segctor_destroy_segment_buffers(sci);
2205 nilfs_segctor_check_out_files(sci, sbi);
2206 return err;
2207
2208 failed_to_write:
2209 nilfs_segctor_abort_write(sci, failed_page, err);
2210 nilfs_segctor_cancel_segusage(sci, nilfs->ns_sufile);
2211
2212 failed_to_make_up:
2213 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2214 nilfs_redirty_inodes(&sci->sc_dirty_files);
2215
2216 failed:
2217 if (nilfs_doing_gc())
2218 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2219 nilfs_segctor_end_construction(sci, nilfs, err);
2220 goto out;
2221 }
2222
2223 /**
2224 * nilfs_secgtor_start_timer - set timer of background write
2225 * @sci: nilfs_sc_info
2226 *
2227 * If the timer has already been set, it ignores the new request.
2228 * This function MUST be called within a section locking the segment
2229 * semaphore.
2230 */
2231 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2232 {
2233 spin_lock(&sci->sc_state_lock);
2234 if (sci->sc_timer && !(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2235 sci->sc_timer->expires = jiffies + sci->sc_interval;
2236 add_timer(sci->sc_timer);
2237 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2238 }
2239 spin_unlock(&sci->sc_state_lock);
2240 }
2241
2242 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2243 {
2244 spin_lock(&sci->sc_state_lock);
2245 if (!(sci->sc_flush_request & (1 << bn))) {
2246 unsigned long prev_req = sci->sc_flush_request;
2247
2248 sci->sc_flush_request |= (1 << bn);
2249 if (!prev_req)
2250 wake_up(&sci->sc_wait_daemon);
2251 }
2252 spin_unlock(&sci->sc_state_lock);
2253 }
2254
2255 /**
2256 * nilfs_flush_segment - trigger a segment construction for resource control
2257 * @sb: super block
2258 * @ino: inode number of the file to be flushed out.
2259 */
2260 void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2261 {
2262 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2263 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2264
2265 if (!sci || nilfs_doing_construction())
2266 return;
2267 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2268 /* assign bit 0 to data files */
2269 }
2270
2271 struct nilfs_segctor_wait_request {
2272 wait_queue_t wq;
2273 __u32 seq;
2274 int err;
2275 atomic_t done;
2276 };
2277
2278 static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2279 {
2280 struct nilfs_segctor_wait_request wait_req;
2281 int err = 0;
2282
2283 spin_lock(&sci->sc_state_lock);
2284 init_wait(&wait_req.wq);
2285 wait_req.err = 0;
2286 atomic_set(&wait_req.done, 0);
2287 wait_req.seq = ++sci->sc_seq_request;
2288 spin_unlock(&sci->sc_state_lock);
2289
2290 init_waitqueue_entry(&wait_req.wq, current);
2291 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2292 set_current_state(TASK_INTERRUPTIBLE);
2293 wake_up(&sci->sc_wait_daemon);
2294
2295 for (;;) {
2296 if (atomic_read(&wait_req.done)) {
2297 err = wait_req.err;
2298 break;
2299 }
2300 if (!signal_pending(current)) {
2301 schedule();
2302 continue;
2303 }
2304 err = -ERESTARTSYS;
2305 break;
2306 }
2307 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2308 return err;
2309 }
2310
2311 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2312 {
2313 struct nilfs_segctor_wait_request *wrq, *n;
2314 unsigned long flags;
2315
2316 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2317 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2318 wq.task_list) {
2319 if (!atomic_read(&wrq->done) &&
2320 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2321 wrq->err = err;
2322 atomic_set(&wrq->done, 1);
2323 }
2324 if (atomic_read(&wrq->done)) {
2325 wrq->wq.func(&wrq->wq,
2326 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2327 0, NULL);
2328 }
2329 }
2330 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2331 }
2332
2333 /**
2334 * nilfs_construct_segment - construct a logical segment
2335 * @sb: super block
2336 *
2337 * Return Value: On success, 0 is retured. On errors, one of the following
2338 * negative error code is returned.
2339 *
2340 * %-EROFS - Read only filesystem.
2341 *
2342 * %-EIO - I/O error
2343 *
2344 * %-ENOSPC - No space left on device (only in a panic state).
2345 *
2346 * %-ERESTARTSYS - Interrupted.
2347 *
2348 * %-ENOMEM - Insufficient memory available.
2349 */
2350 int nilfs_construct_segment(struct super_block *sb)
2351 {
2352 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2353 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2354 struct nilfs_transaction_info *ti;
2355 int err;
2356
2357 if (!sci)
2358 return -EROFS;
2359
2360 /* A call inside transactions causes a deadlock. */
2361 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2362
2363 err = nilfs_segctor_sync(sci);
2364 return err;
2365 }
2366
2367 /**
2368 * nilfs_construct_dsync_segment - construct a data-only logical segment
2369 * @sb: super block
2370 * @inode: inode whose data blocks should be written out
2371 * @start: start byte offset
2372 * @end: end byte offset (inclusive)
2373 *
2374 * Return Value: On success, 0 is retured. On errors, one of the following
2375 * negative error code is returned.
2376 *
2377 * %-EROFS - Read only filesystem.
2378 *
2379 * %-EIO - I/O error
2380 *
2381 * %-ENOSPC - No space left on device (only in a panic state).
2382 *
2383 * %-ERESTARTSYS - Interrupted.
2384 *
2385 * %-ENOMEM - Insufficient memory available.
2386 */
2387 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2388 loff_t start, loff_t end)
2389 {
2390 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2391 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2392 struct nilfs_inode_info *ii;
2393 struct nilfs_transaction_info ti;
2394 int err = 0;
2395
2396 if (!sci)
2397 return -EROFS;
2398
2399 nilfs_transaction_lock(sbi, &ti, 0);
2400
2401 ii = NILFS_I(inode);
2402 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
2403 nilfs_test_opt(sbi, STRICT_ORDER) ||
2404 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2405 nilfs_discontinued(sbi->s_nilfs)) {
2406 nilfs_transaction_unlock(sbi);
2407 err = nilfs_segctor_sync(sci);
2408 return err;
2409 }
2410
2411 spin_lock(&sbi->s_inode_lock);
2412 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2413 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2414 spin_unlock(&sbi->s_inode_lock);
2415 nilfs_transaction_unlock(sbi);
2416 return 0;
2417 }
2418 spin_unlock(&sbi->s_inode_lock);
2419 sci->sc_dsync_inode = ii;
2420 sci->sc_dsync_start = start;
2421 sci->sc_dsync_end = end;
2422
2423 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2424
2425 nilfs_transaction_unlock(sbi);
2426 return err;
2427 }
2428
2429 struct nilfs_segctor_req {
2430 int mode;
2431 __u32 seq_accepted;
2432 int sc_err; /* construction failure */
2433 int sb_err; /* super block writeback failure */
2434 };
2435
2436 #define FLUSH_FILE_BIT (0x1) /* data file only */
2437 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2438
2439 static void nilfs_segctor_accept(struct nilfs_sc_info *sci,
2440 struct nilfs_segctor_req *req)
2441 {
2442 req->sc_err = req->sb_err = 0;
2443 spin_lock(&sci->sc_state_lock);
2444 req->seq_accepted = sci->sc_seq_request;
2445 spin_unlock(&sci->sc_state_lock);
2446
2447 if (sci->sc_timer)
2448 del_timer_sync(sci->sc_timer);
2449 }
2450
2451 static void nilfs_segctor_notify(struct nilfs_sc_info *sci,
2452 struct nilfs_segctor_req *req)
2453 {
2454 /* Clear requests (even when the construction failed) */
2455 spin_lock(&sci->sc_state_lock);
2456
2457 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2458
2459 if (req->mode == SC_LSEG_SR) {
2460 sci->sc_seq_done = req->seq_accepted;
2461 nilfs_segctor_wakeup(sci, req->sc_err ? : req->sb_err);
2462 sci->sc_flush_request = 0;
2463 } else if (req->mode == SC_FLUSH_FILE)
2464 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2465 else if (req->mode == SC_FLUSH_DAT)
2466 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2467
2468 spin_unlock(&sci->sc_state_lock);
2469 }
2470
2471 static int nilfs_segctor_construct(struct nilfs_sc_info *sci,
2472 struct nilfs_segctor_req *req)
2473 {
2474 struct nilfs_sb_info *sbi = sci->sc_sbi;
2475 struct the_nilfs *nilfs = sbi->s_nilfs;
2476 int err = 0;
2477
2478 if (nilfs_discontinued(nilfs))
2479 req->mode = SC_LSEG_SR;
2480 if (!nilfs_segctor_confirm(sci)) {
2481 err = nilfs_segctor_do_construct(sci, req->mode);
2482 req->sc_err = err;
2483 }
2484 if (likely(!err)) {
2485 if (req->mode != SC_FLUSH_DAT)
2486 atomic_set(&nilfs->ns_ndirtyblks, 0);
2487 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2488 nilfs_discontinued(nilfs)) {
2489 down_write(&nilfs->ns_sem);
2490 req->sb_err = nilfs_commit_super(sbi, 0);
2491 up_write(&nilfs->ns_sem);
2492 }
2493 }
2494 return err;
2495 }
2496
2497 static void nilfs_construction_timeout(unsigned long data)
2498 {
2499 struct task_struct *p = (struct task_struct *)data;
2500 wake_up_process(p);
2501 }
2502
2503 static void
2504 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2505 {
2506 struct nilfs_inode_info *ii, *n;
2507
2508 list_for_each_entry_safe(ii, n, head, i_dirty) {
2509 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2510 continue;
2511 hlist_del_init(&ii->vfs_inode.i_hash);
2512 list_del_init(&ii->i_dirty);
2513 nilfs_clear_gcinode(&ii->vfs_inode);
2514 }
2515 }
2516
2517 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2518 void **kbufs)
2519 {
2520 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2521 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2522 struct the_nilfs *nilfs = sbi->s_nilfs;
2523 struct nilfs_transaction_info ti;
2524 struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
2525 int err;
2526
2527 if (unlikely(!sci))
2528 return -EROFS;
2529
2530 nilfs_transaction_lock(sbi, &ti, 1);
2531
2532 err = nilfs_init_gcdat_inode(nilfs);
2533 if (unlikely(err))
2534 goto out_unlock;
2535
2536 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2537 if (unlikely(err))
2538 goto out_unlock;
2539
2540 sci->sc_freesegs = kbufs[4];
2541 sci->sc_nfreesegs = argv[4].v_nmembs;
2542 list_splice_init(&nilfs->ns_gc_inodes, sci->sc_gc_inodes.prev);
2543
2544 for (;;) {
2545 nilfs_segctor_accept(sci, &req);
2546 err = nilfs_segctor_construct(sci, &req);
2547 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2548 nilfs_segctor_notify(sci, &req);
2549
2550 if (likely(!err))
2551 break;
2552
2553 nilfs_warning(sb, __func__,
2554 "segment construction failed. (err=%d)", err);
2555 set_current_state(TASK_INTERRUPTIBLE);
2556 schedule_timeout(sci->sc_interval);
2557 }
2558
2559 out_unlock:
2560 sci->sc_freesegs = NULL;
2561 sci->sc_nfreesegs = 0;
2562 nilfs_clear_gcdat_inode(nilfs);
2563 nilfs_transaction_unlock(sbi);
2564 return err;
2565 }
2566
2567 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2568 {
2569 struct nilfs_sb_info *sbi = sci->sc_sbi;
2570 struct nilfs_transaction_info ti;
2571 struct nilfs_segctor_req req = { .mode = mode };
2572
2573 nilfs_transaction_lock(sbi, &ti, 0);
2574
2575 nilfs_segctor_accept(sci, &req);
2576 nilfs_segctor_construct(sci, &req);
2577 nilfs_segctor_notify(sci, &req);
2578
2579 /*
2580 * Unclosed segment should be retried. We do this using sc_timer.
2581 * Timeout of sc_timer will invoke complete construction which leads
2582 * to close the current logical segment.
2583 */
2584 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2585 nilfs_segctor_start_timer(sci);
2586
2587 nilfs_transaction_unlock(sbi);
2588 }
2589
2590 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2591 {
2592 int mode = 0;
2593 int err;
2594
2595 spin_lock(&sci->sc_state_lock);
2596 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2597 SC_FLUSH_DAT : SC_FLUSH_FILE;
2598 spin_unlock(&sci->sc_state_lock);
2599
2600 if (mode) {
2601 err = nilfs_segctor_do_construct(sci, mode);
2602
2603 spin_lock(&sci->sc_state_lock);
2604 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2605 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2606 spin_unlock(&sci->sc_state_lock);
2607 }
2608 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2609 }
2610
2611 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2612 {
2613 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2614 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2615 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2616 return SC_FLUSH_FILE;
2617 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2618 return SC_FLUSH_DAT;
2619 }
2620 return SC_LSEG_SR;
2621 }
2622
2623 /**
2624 * nilfs_segctor_thread - main loop of the segment constructor thread.
2625 * @arg: pointer to a struct nilfs_sc_info.
2626 *
2627 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2628 * to execute segment constructions.
2629 */
2630 static int nilfs_segctor_thread(void *arg)
2631 {
2632 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2633 struct timer_list timer;
2634 int timeout = 0;
2635
2636 init_timer(&timer);
2637 timer.data = (unsigned long)current;
2638 timer.function = nilfs_construction_timeout;
2639 sci->sc_timer = &timer;
2640
2641 /* start sync. */
2642 sci->sc_task = current;
2643 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2644 printk(KERN_INFO
2645 "segctord starting. Construction interval = %lu seconds, "
2646 "CP frequency < %lu seconds\n",
2647 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2648
2649 spin_lock(&sci->sc_state_lock);
2650 loop:
2651 for (;;) {
2652 int mode;
2653
2654 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2655 goto end_thread;
2656
2657 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2658 mode = SC_LSEG_SR;
2659 else if (!sci->sc_flush_request)
2660 break;
2661 else
2662 mode = nilfs_segctor_flush_mode(sci);
2663
2664 spin_unlock(&sci->sc_state_lock);
2665 nilfs_segctor_thread_construct(sci, mode);
2666 spin_lock(&sci->sc_state_lock);
2667 timeout = 0;
2668 }
2669
2670
2671 if (freezing(current)) {
2672 spin_unlock(&sci->sc_state_lock);
2673 refrigerator();
2674 spin_lock(&sci->sc_state_lock);
2675 } else {
2676 DEFINE_WAIT(wait);
2677 int should_sleep = 1;
2678
2679 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2680 TASK_INTERRUPTIBLE);
2681
2682 if (sci->sc_seq_request != sci->sc_seq_done)
2683 should_sleep = 0;
2684 else if (sci->sc_flush_request)
2685 should_sleep = 0;
2686 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2687 should_sleep = time_before(jiffies,
2688 sci->sc_timer->expires);
2689
2690 if (should_sleep) {
2691 spin_unlock(&sci->sc_state_lock);
2692 schedule();
2693 spin_lock(&sci->sc_state_lock);
2694 }
2695 finish_wait(&sci->sc_wait_daemon, &wait);
2696 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2697 time_after_eq(jiffies, sci->sc_timer->expires));
2698 }
2699 goto loop;
2700
2701 end_thread:
2702 spin_unlock(&sci->sc_state_lock);
2703 del_timer_sync(sci->sc_timer);
2704 sci->sc_timer = NULL;
2705
2706 /* end sync. */
2707 sci->sc_task = NULL;
2708 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2709 return 0;
2710 }
2711
2712 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2713 {
2714 struct task_struct *t;
2715
2716 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2717 if (IS_ERR(t)) {
2718 int err = PTR_ERR(t);
2719
2720 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2721 err);
2722 return err;
2723 }
2724 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2725 return 0;
2726 }
2727
2728 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2729 {
2730 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2731
2732 while (sci->sc_task) {
2733 wake_up(&sci->sc_wait_daemon);
2734 spin_unlock(&sci->sc_state_lock);
2735 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2736 spin_lock(&sci->sc_state_lock);
2737 }
2738 }
2739
2740 static int nilfs_segctor_init(struct nilfs_sc_info *sci)
2741 {
2742 sci->sc_seq_done = sci->sc_seq_request;
2743
2744 return nilfs_segctor_start_thread(sci);
2745 }
2746
2747 /*
2748 * Setup & clean-up functions
2749 */
2750 static struct nilfs_sc_info *nilfs_segctor_new(struct nilfs_sb_info *sbi)
2751 {
2752 struct nilfs_sc_info *sci;
2753
2754 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2755 if (!sci)
2756 return NULL;
2757
2758 sci->sc_sbi = sbi;
2759 sci->sc_super = sbi->s_super;
2760
2761 init_waitqueue_head(&sci->sc_wait_request);
2762 init_waitqueue_head(&sci->sc_wait_daemon);
2763 init_waitqueue_head(&sci->sc_wait_task);
2764 spin_lock_init(&sci->sc_state_lock);
2765 INIT_LIST_HEAD(&sci->sc_dirty_files);
2766 INIT_LIST_HEAD(&sci->sc_segbufs);
2767 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2768 INIT_LIST_HEAD(&sci->sc_copied_buffers);
2769
2770 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2771 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2772 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2773
2774 if (sbi->s_interval)
2775 sci->sc_interval = sbi->s_interval;
2776 if (sbi->s_watermark)
2777 sci->sc_watermark = sbi->s_watermark;
2778 return sci;
2779 }
2780
2781 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2782 {
2783 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2784
2785 /* The segctord thread was stopped and its timer was removed.
2786 But some tasks remain. */
2787 do {
2788 struct nilfs_sb_info *sbi = sci->sc_sbi;
2789 struct nilfs_transaction_info ti;
2790 struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
2791
2792 nilfs_transaction_lock(sbi, &ti, 0);
2793 nilfs_segctor_accept(sci, &req);
2794 ret = nilfs_segctor_construct(sci, &req);
2795 nilfs_segctor_notify(sci, &req);
2796 nilfs_transaction_unlock(sbi);
2797
2798 } while (ret && retrycount-- > 0);
2799 }
2800
2801 /**
2802 * nilfs_segctor_destroy - destroy the segment constructor.
2803 * @sci: nilfs_sc_info
2804 *
2805 * nilfs_segctor_destroy() kills the segctord thread and frees
2806 * the nilfs_sc_info struct.
2807 * Caller must hold the segment semaphore.
2808 */
2809 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2810 {
2811 struct nilfs_sb_info *sbi = sci->sc_sbi;
2812 int flag;
2813
2814 up_write(&sbi->s_nilfs->ns_segctor_sem);
2815
2816 spin_lock(&sci->sc_state_lock);
2817 nilfs_segctor_kill_thread(sci);
2818 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2819 || sci->sc_seq_request != sci->sc_seq_done);
2820 spin_unlock(&sci->sc_state_lock);
2821
2822 if (flag || nilfs_segctor_confirm(sci))
2823 nilfs_segctor_write_out(sci);
2824
2825 WARN_ON(!list_empty(&sci->sc_copied_buffers));
2826
2827 if (!list_empty(&sci->sc_dirty_files)) {
2828 nilfs_warning(sbi->s_super, __func__,
2829 "dirty file(s) after the final construction\n");
2830 nilfs_dispose_list(sbi, &sci->sc_dirty_files, 1);
2831 }
2832
2833 WARN_ON(!list_empty(&sci->sc_segbufs));
2834
2835 down_write(&sbi->s_nilfs->ns_segctor_sem);
2836
2837 kfree(sci);
2838 }
2839
2840 /**
2841 * nilfs_attach_segment_constructor - attach a segment constructor
2842 * @sbi: nilfs_sb_info
2843 *
2844 * nilfs_attach_segment_constructor() allocates a struct nilfs_sc_info,
2845 * initilizes it, and starts the segment constructor.
2846 *
2847 * Return Value: On success, 0 is returned. On error, one of the following
2848 * negative error code is returned.
2849 *
2850 * %-ENOMEM - Insufficient memory available.
2851 */
2852 int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi)
2853 {
2854 struct the_nilfs *nilfs = sbi->s_nilfs;
2855 int err;
2856
2857 /* Each field of nilfs_segctor is cleared through the initialization
2858 of super-block info */
2859 sbi->s_sc_info = nilfs_segctor_new(sbi);
2860 if (!sbi->s_sc_info)
2861 return -ENOMEM;
2862
2863 nilfs_attach_writer(nilfs, sbi);
2864 err = nilfs_segctor_init(NILFS_SC(sbi));
2865 if (err) {
2866 nilfs_detach_writer(nilfs, sbi);
2867 kfree(sbi->s_sc_info);
2868 sbi->s_sc_info = NULL;
2869 }
2870 return err;
2871 }
2872
2873 /**
2874 * nilfs_detach_segment_constructor - destroy the segment constructor
2875 * @sbi: nilfs_sb_info
2876 *
2877 * nilfs_detach_segment_constructor() kills the segment constructor daemon,
2878 * frees the struct nilfs_sc_info, and destroy the dirty file list.
2879 */
2880 void nilfs_detach_segment_constructor(struct nilfs_sb_info *sbi)
2881 {
2882 struct the_nilfs *nilfs = sbi->s_nilfs;
2883 LIST_HEAD(garbage_list);
2884
2885 down_write(&nilfs->ns_segctor_sem);
2886 if (NILFS_SC(sbi)) {
2887 nilfs_segctor_destroy(NILFS_SC(sbi));
2888 sbi->s_sc_info = NULL;
2889 }
2890
2891 /* Force to free the list of dirty files */
2892 spin_lock(&sbi->s_inode_lock);
2893 if (!list_empty(&sbi->s_dirty_files)) {
2894 list_splice_init(&sbi->s_dirty_files, &garbage_list);
2895 nilfs_warning(sbi->s_super, __func__,
2896 "Non empty dirty list after the last "
2897 "segment construction\n");
2898 }
2899 spin_unlock(&sbi->s_inode_lock);
2900 up_write(&nilfs->ns_segctor_sem);
2901
2902 nilfs_dispose_list(sbi, &garbage_list, 1);
2903 nilfs_detach_writer(nilfs, sbi);
2904 }
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