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Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
[mirror_ubuntu-kernels.git] / fs / nilfs2 / segment.c
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 "seglist.h"
43 #include "segbuf.h"
44
45
46 /*
47 * Segment constructor
48 */
49 #define SC_N_INODEVEC 16 /* Size of locally allocated inode vector */
50
51 #define SC_MAX_SEGDELTA 64 /* Upper limit of the number of segments
52 appended in collection retry loop */
53
54 /* Construction mode */
55 enum {
56 SC_LSEG_SR = 1, /* Make a logical segment having a super root */
57 SC_LSEG_DSYNC, /* Flush data blocks of a given file and make
58 a logical segment without a super root */
59 SC_FLUSH_FILE, /* Flush data files, leads to segment writes without
60 creating a checkpoint */
61 SC_FLUSH_DAT, /* Flush DAT file. This also creates segments without
62 a checkpoint */
63 };
64
65 /* Stage numbers of dirty block collection */
66 enum {
67 NILFS_ST_INIT = 0,
68 NILFS_ST_GC, /* Collecting dirty blocks for GC */
69 NILFS_ST_FILE,
70 NILFS_ST_IFILE,
71 NILFS_ST_CPFILE,
72 NILFS_ST_SUFILE,
73 NILFS_ST_DAT,
74 NILFS_ST_SR, /* Super root */
75 NILFS_ST_DSYNC, /* Data sync blocks */
76 NILFS_ST_DONE,
77 };
78
79 /* State flags of collection */
80 #define NILFS_CF_NODE 0x0001 /* Collecting node blocks */
81 #define NILFS_CF_IFILE_STARTED 0x0002 /* IFILE stage has started */
82 #define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED)
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 list_empty(&sci->sc_cleaning_segments) &&
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 void nilfs_segctor_cancel_free_segments(struct nilfs_sc_info *sci,
1009 struct inode *sufile)
1010
1011 {
1012 struct list_head *head = &sci->sc_cleaning_segments;
1013 struct nilfs_segment_entry *ent;
1014 int err;
1015
1016 list_for_each_entry(ent, head, list) {
1017 if (!(ent->flags & NILFS_SLH_FREED))
1018 break;
1019 err = nilfs_sufile_cancel_free(sufile, ent->segnum);
1020 WARN_ON(err); /* do not happen */
1021 ent->flags &= ~NILFS_SLH_FREED;
1022 }
1023 }
1024
1025 static int nilfs_segctor_prepare_free_segments(struct nilfs_sc_info *sci,
1026 struct inode *sufile)
1027 {
1028 struct list_head *head = &sci->sc_cleaning_segments;
1029 struct nilfs_segment_entry *ent;
1030 int err;
1031
1032 list_for_each_entry(ent, head, list) {
1033 err = nilfs_sufile_free(sufile, ent->segnum);
1034 if (unlikely(err))
1035 return err;
1036 ent->flags |= NILFS_SLH_FREED;
1037 }
1038 return 0;
1039 }
1040
1041 static void nilfs_segctor_commit_free_segments(struct nilfs_sc_info *sci)
1042 {
1043 nilfs_dispose_segment_list(&sci->sc_cleaning_segments);
1044 }
1045
1046 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
1047 struct inode *inode,
1048 struct list_head *listp,
1049 int (*collect)(struct nilfs_sc_info *,
1050 struct buffer_head *,
1051 struct inode *))
1052 {
1053 struct buffer_head *bh, *n;
1054 int err = 0;
1055
1056 if (collect) {
1057 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
1058 list_del_init(&bh->b_assoc_buffers);
1059 err = collect(sci, bh, inode);
1060 brelse(bh);
1061 if (unlikely(err))
1062 goto dispose_buffers;
1063 }
1064 return 0;
1065 }
1066
1067 dispose_buffers:
1068 while (!list_empty(listp)) {
1069 bh = list_entry(listp->next, struct buffer_head,
1070 b_assoc_buffers);
1071 list_del_init(&bh->b_assoc_buffers);
1072 brelse(bh);
1073 }
1074 return err;
1075 }
1076
1077 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
1078 {
1079 /* Remaining number of blocks within segment buffer */
1080 return sci->sc_segbuf_nblocks -
1081 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
1082 }
1083
1084 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
1085 struct inode *inode,
1086 struct nilfs_sc_operations *sc_ops)
1087 {
1088 LIST_HEAD(data_buffers);
1089 LIST_HEAD(node_buffers);
1090 int err;
1091
1092 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1093 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1094
1095 n = nilfs_lookup_dirty_data_buffers(
1096 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
1097 if (n > rest) {
1098 err = nilfs_segctor_apply_buffers(
1099 sci, inode, &data_buffers,
1100 sc_ops->collect_data);
1101 BUG_ON(!err); /* always receive -E2BIG or true error */
1102 goto break_or_fail;
1103 }
1104 }
1105 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
1106
1107 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1108 err = nilfs_segctor_apply_buffers(
1109 sci, inode, &data_buffers, sc_ops->collect_data);
1110 if (unlikely(err)) {
1111 /* dispose node list */
1112 nilfs_segctor_apply_buffers(
1113 sci, inode, &node_buffers, NULL);
1114 goto break_or_fail;
1115 }
1116 sci->sc_stage.flags |= NILFS_CF_NODE;
1117 }
1118 /* Collect node */
1119 err = nilfs_segctor_apply_buffers(
1120 sci, inode, &node_buffers, sc_ops->collect_node);
1121 if (unlikely(err))
1122 goto break_or_fail;
1123
1124 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1125 err = nilfs_segctor_apply_buffers(
1126 sci, inode, &node_buffers, sc_ops->collect_bmap);
1127 if (unlikely(err))
1128 goto break_or_fail;
1129
1130 nilfs_segctor_end_finfo(sci, inode);
1131 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1132
1133 break_or_fail:
1134 return err;
1135 }
1136
1137 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1138 struct inode *inode)
1139 {
1140 LIST_HEAD(data_buffers);
1141 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1142 int err;
1143
1144 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1145 sci->sc_dsync_start,
1146 sci->sc_dsync_end);
1147
1148 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1149 nilfs_collect_file_data);
1150 if (!err) {
1151 nilfs_segctor_end_finfo(sci, inode);
1152 BUG_ON(n > rest);
1153 /* always receive -E2BIG or true error if n > rest */
1154 }
1155 return err;
1156 }
1157
1158 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1159 {
1160 struct nilfs_sb_info *sbi = sci->sc_sbi;
1161 struct the_nilfs *nilfs = sbi->s_nilfs;
1162 struct list_head *head;
1163 struct nilfs_inode_info *ii;
1164 int err = 0;
1165
1166 switch (sci->sc_stage.scnt) {
1167 case NILFS_ST_INIT:
1168 /* Pre-processes */
1169 sci->sc_stage.flags = 0;
1170
1171 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1172 sci->sc_nblk_inc = 0;
1173 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1174 if (mode == SC_LSEG_DSYNC) {
1175 sci->sc_stage.scnt = NILFS_ST_DSYNC;
1176 goto dsync_mode;
1177 }
1178 }
1179
1180 sci->sc_stage.dirty_file_ptr = NULL;
1181 sci->sc_stage.gc_inode_ptr = NULL;
1182 if (mode == SC_FLUSH_DAT) {
1183 sci->sc_stage.scnt = NILFS_ST_DAT;
1184 goto dat_stage;
1185 }
1186 sci->sc_stage.scnt++; /* Fall through */
1187 case NILFS_ST_GC:
1188 if (nilfs_doing_gc()) {
1189 head = &sci->sc_gc_inodes;
1190 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1191 head, i_dirty);
1192 list_for_each_entry_continue(ii, head, i_dirty) {
1193 err = nilfs_segctor_scan_file(
1194 sci, &ii->vfs_inode,
1195 &nilfs_sc_file_ops);
1196 if (unlikely(err)) {
1197 sci->sc_stage.gc_inode_ptr = list_entry(
1198 ii->i_dirty.prev,
1199 struct nilfs_inode_info,
1200 i_dirty);
1201 goto break_or_fail;
1202 }
1203 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1204 }
1205 sci->sc_stage.gc_inode_ptr = NULL;
1206 }
1207 sci->sc_stage.scnt++; /* Fall through */
1208 case NILFS_ST_FILE:
1209 head = &sci->sc_dirty_files;
1210 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1211 i_dirty);
1212 list_for_each_entry_continue(ii, head, i_dirty) {
1213 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1214
1215 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1216 &nilfs_sc_file_ops);
1217 if (unlikely(err)) {
1218 sci->sc_stage.dirty_file_ptr =
1219 list_entry(ii->i_dirty.prev,
1220 struct nilfs_inode_info,
1221 i_dirty);
1222 goto break_or_fail;
1223 }
1224 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1225 /* XXX: required ? */
1226 }
1227 sci->sc_stage.dirty_file_ptr = NULL;
1228 if (mode == SC_FLUSH_FILE) {
1229 sci->sc_stage.scnt = NILFS_ST_DONE;
1230 return 0;
1231 }
1232 sci->sc_stage.scnt++;
1233 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1234 /* Fall through */
1235 case NILFS_ST_IFILE:
1236 err = nilfs_segctor_scan_file(sci, sbi->s_ifile,
1237 &nilfs_sc_file_ops);
1238 if (unlikely(err))
1239 break;
1240 sci->sc_stage.scnt++;
1241 /* Creating a checkpoint */
1242 err = nilfs_segctor_create_checkpoint(sci);
1243 if (unlikely(err))
1244 break;
1245 /* Fall through */
1246 case NILFS_ST_CPFILE:
1247 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1248 &nilfs_sc_file_ops);
1249 if (unlikely(err))
1250 break;
1251 sci->sc_stage.scnt++; /* Fall through */
1252 case NILFS_ST_SUFILE:
1253 err = nilfs_segctor_prepare_free_segments(sci,
1254 nilfs->ns_sufile);
1255 if (unlikely(err))
1256 break;
1257 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1258 &nilfs_sc_file_ops);
1259 if (unlikely(err))
1260 break;
1261 sci->sc_stage.scnt++; /* Fall through */
1262 case NILFS_ST_DAT:
1263 dat_stage:
1264 err = nilfs_segctor_scan_file(sci, nilfs_dat_inode(nilfs),
1265 &nilfs_sc_dat_ops);
1266 if (unlikely(err))
1267 break;
1268 if (mode == SC_FLUSH_DAT) {
1269 sci->sc_stage.scnt = NILFS_ST_DONE;
1270 return 0;
1271 }
1272 sci->sc_stage.scnt++; /* Fall through */
1273 case NILFS_ST_SR:
1274 if (mode == SC_LSEG_SR) {
1275 /* Appending a super root */
1276 err = nilfs_segctor_add_super_root(sci);
1277 if (unlikely(err))
1278 break;
1279 }
1280 /* End of a logical segment */
1281 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1282 sci->sc_stage.scnt = NILFS_ST_DONE;
1283 return 0;
1284 case NILFS_ST_DSYNC:
1285 dsync_mode:
1286 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1287 ii = sci->sc_dsync_inode;
1288 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1289 break;
1290
1291 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1292 if (unlikely(err))
1293 break;
1294 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1295 sci->sc_stage.scnt = NILFS_ST_DONE;
1296 return 0;
1297 case NILFS_ST_DONE:
1298 return 0;
1299 default:
1300 BUG();
1301 }
1302
1303 break_or_fail:
1304 return err;
1305 }
1306
1307 static int nilfs_touch_segusage(struct inode *sufile, __u64 segnum)
1308 {
1309 struct buffer_head *bh_su;
1310 struct nilfs_segment_usage *raw_su;
1311 int err;
1312
1313 err = nilfs_sufile_get_segment_usage(sufile, segnum, &raw_su, &bh_su);
1314 if (unlikely(err))
1315 return err;
1316 nilfs_mdt_mark_buffer_dirty(bh_su);
1317 nilfs_mdt_mark_dirty(sufile);
1318 nilfs_sufile_put_segment_usage(sufile, segnum, bh_su);
1319 return 0;
1320 }
1321
1322 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1323 struct the_nilfs *nilfs)
1324 {
1325 struct nilfs_segment_buffer *segbuf, *n;
1326 __u64 nextnum;
1327 int err;
1328
1329 if (list_empty(&sci->sc_segbufs)) {
1330 segbuf = nilfs_segbuf_new(sci->sc_super);
1331 if (unlikely(!segbuf))
1332 return -ENOMEM;
1333 list_add(&segbuf->sb_list, &sci->sc_segbufs);
1334 } else
1335 segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1336
1337 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, nilfs->ns_pseg_offset,
1338 nilfs);
1339
1340 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1341 nilfs_shift_to_next_segment(nilfs);
1342 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1343 }
1344 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1345
1346 err = nilfs_touch_segusage(nilfs->ns_sufile, segbuf->sb_segnum);
1347 if (unlikely(err))
1348 return err;
1349
1350 if (nilfs->ns_segnum == nilfs->ns_nextnum) {
1351 /* Start from the head of a new full segment */
1352 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1353 if (unlikely(err))
1354 return err;
1355 } else
1356 nextnum = nilfs->ns_nextnum;
1357
1358 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1359 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1360
1361 /* truncating segment buffers */
1362 list_for_each_entry_safe_continue(segbuf, n, &sci->sc_segbufs,
1363 sb_list) {
1364 list_del_init(&segbuf->sb_list);
1365 nilfs_segbuf_free(segbuf);
1366 }
1367 return 0;
1368 }
1369
1370 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1371 struct the_nilfs *nilfs, int nadd)
1372 {
1373 struct nilfs_segment_buffer *segbuf, *prev, *n;
1374 struct inode *sufile = nilfs->ns_sufile;
1375 __u64 nextnextnum;
1376 LIST_HEAD(list);
1377 int err, ret, i;
1378
1379 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1380 /*
1381 * Since the segment specified with nextnum might be allocated during
1382 * the previous construction, the buffer including its segusage may
1383 * not be dirty. The following call ensures that the buffer is dirty
1384 * and will pin the buffer on memory until the sufile is written.
1385 */
1386 err = nilfs_touch_segusage(sufile, prev->sb_nextnum);
1387 if (unlikely(err))
1388 return err;
1389
1390 for (i = 0; i < nadd; i++) {
1391 /* extend segment info */
1392 err = -ENOMEM;
1393 segbuf = nilfs_segbuf_new(sci->sc_super);
1394 if (unlikely(!segbuf))
1395 goto failed;
1396
1397 /* map this buffer to region of segment on-disk */
1398 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1399 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1400
1401 /* allocate the next next full segment */
1402 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1403 if (unlikely(err))
1404 goto failed_segbuf;
1405
1406 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1407 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1408
1409 list_add_tail(&segbuf->sb_list, &list);
1410 prev = segbuf;
1411 }
1412 list_splice(&list, sci->sc_segbufs.prev);
1413 return 0;
1414
1415 failed_segbuf:
1416 nilfs_segbuf_free(segbuf);
1417 failed:
1418 list_for_each_entry_safe(segbuf, n, &list, sb_list) {
1419 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1420 WARN_ON(ret); /* never fails */
1421 list_del_init(&segbuf->sb_list);
1422 nilfs_segbuf_free(segbuf);
1423 }
1424 return err;
1425 }
1426
1427 static void nilfs_segctor_free_incomplete_segments(struct nilfs_sc_info *sci,
1428 struct the_nilfs *nilfs)
1429 {
1430 struct nilfs_segment_buffer *segbuf;
1431 int ret, done = 0;
1432
1433 segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1434 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1435 ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
1436 WARN_ON(ret); /* never fails */
1437 }
1438 if (segbuf->sb_io_error) {
1439 /* Case 1: The first segment failed */
1440 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1441 /* Case 1a: Partial segment appended into an existing
1442 segment */
1443 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1444 segbuf->sb_fseg_end);
1445 else /* Case 1b: New full segment */
1446 set_nilfs_discontinued(nilfs);
1447 done++;
1448 }
1449
1450 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1451 ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
1452 WARN_ON(ret); /* never fails */
1453 if (!done && segbuf->sb_io_error) {
1454 if (segbuf->sb_segnum != nilfs->ns_nextnum)
1455 /* Case 2: extended segment (!= next) failed */
1456 nilfs_sufile_set_error(nilfs->ns_sufile,
1457 segbuf->sb_segnum);
1458 done++;
1459 }
1460 }
1461 }
1462
1463 static void nilfs_segctor_clear_segment_buffers(struct nilfs_sc_info *sci)
1464 {
1465 struct nilfs_segment_buffer *segbuf;
1466
1467 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list)
1468 nilfs_segbuf_clear(segbuf);
1469 sci->sc_super_root = NULL;
1470 }
1471
1472 static void nilfs_segctor_destroy_segment_buffers(struct nilfs_sc_info *sci)
1473 {
1474 struct nilfs_segment_buffer *segbuf;
1475
1476 while (!list_empty(&sci->sc_segbufs)) {
1477 segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1478 list_del_init(&segbuf->sb_list);
1479 nilfs_segbuf_free(segbuf);
1480 }
1481 /* sci->sc_curseg = NULL; */
1482 }
1483
1484 static void nilfs_segctor_end_construction(struct nilfs_sc_info *sci,
1485 struct the_nilfs *nilfs, int err)
1486 {
1487 if (unlikely(err)) {
1488 nilfs_segctor_free_incomplete_segments(sci, nilfs);
1489 nilfs_segctor_cancel_free_segments(sci, nilfs->ns_sufile);
1490 }
1491 nilfs_segctor_clear_segment_buffers(sci);
1492 }
1493
1494 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1495 struct inode *sufile)
1496 {
1497 struct nilfs_segment_buffer *segbuf;
1498 struct buffer_head *bh_su;
1499 struct nilfs_segment_usage *raw_su;
1500 unsigned long live_blocks;
1501 int ret;
1502
1503 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1504 ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
1505 &raw_su, &bh_su);
1506 WARN_ON(ret); /* always succeed because bh_su is dirty */
1507 live_blocks = segbuf->sb_sum.nblocks +
1508 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1509 raw_su->su_lastmod = cpu_to_le64(sci->sc_seg_ctime);
1510 raw_su->su_nblocks = cpu_to_le32(live_blocks);
1511 nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum,
1512 bh_su);
1513 }
1514 }
1515
1516 static void nilfs_segctor_cancel_segusage(struct nilfs_sc_info *sci,
1517 struct inode *sufile)
1518 {
1519 struct nilfs_segment_buffer *segbuf;
1520 struct buffer_head *bh_su;
1521 struct nilfs_segment_usage *raw_su;
1522 int ret;
1523
1524 segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1525 ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
1526 &raw_su, &bh_su);
1527 WARN_ON(ret); /* always succeed because bh_su is dirty */
1528 raw_su->su_nblocks = cpu_to_le32(segbuf->sb_pseg_start -
1529 segbuf->sb_fseg_start);
1530 nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum, bh_su);
1531
1532 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1533 ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
1534 &raw_su, &bh_su);
1535 WARN_ON(ret); /* always succeed */
1536 raw_su->su_nblocks = 0;
1537 nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum,
1538 bh_su);
1539 }
1540 }
1541
1542 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1543 struct nilfs_segment_buffer *last,
1544 struct inode *sufile)
1545 {
1546 struct nilfs_segment_buffer *segbuf = last, *n;
1547 int ret;
1548
1549 list_for_each_entry_safe_continue(segbuf, n, &sci->sc_segbufs,
1550 sb_list) {
1551 list_del_init(&segbuf->sb_list);
1552 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1553 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1554 WARN_ON(ret);
1555 nilfs_segbuf_free(segbuf);
1556 }
1557 }
1558
1559
1560 static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1561 struct the_nilfs *nilfs, int mode)
1562 {
1563 struct nilfs_cstage prev_stage = sci->sc_stage;
1564 int err, nadd = 1;
1565
1566 /* Collection retry loop */
1567 for (;;) {
1568 sci->sc_super_root = NULL;
1569 sci->sc_nblk_this_inc = 0;
1570 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1571
1572 err = nilfs_segctor_reset_segment_buffer(sci);
1573 if (unlikely(err))
1574 goto failed;
1575
1576 err = nilfs_segctor_collect_blocks(sci, mode);
1577 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1578 if (!err)
1579 break;
1580
1581 if (unlikely(err != -E2BIG))
1582 goto failed;
1583
1584 /* The current segment is filled up */
1585 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
1586 break;
1587
1588 nilfs_segctor_cancel_free_segments(sci, nilfs->ns_sufile);
1589 nilfs_segctor_clear_segment_buffers(sci);
1590
1591 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1592 if (unlikely(err))
1593 return err;
1594
1595 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1596 sci->sc_stage = prev_stage;
1597 }
1598 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1599 return 0;
1600
1601 failed:
1602 return err;
1603 }
1604
1605 static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1606 struct buffer_head *new_bh)
1607 {
1608 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1609
1610 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1611 /* The caller must release old_bh */
1612 }
1613
1614 static int
1615 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1616 struct nilfs_segment_buffer *segbuf,
1617 int mode)
1618 {
1619 struct inode *inode = NULL;
1620 sector_t blocknr;
1621 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1622 unsigned long nblocks = 0, ndatablk = 0;
1623 struct nilfs_sc_operations *sc_op = NULL;
1624 struct nilfs_segsum_pointer ssp;
1625 struct nilfs_finfo *finfo = NULL;
1626 union nilfs_binfo binfo;
1627 struct buffer_head *bh, *bh_org;
1628 ino_t ino = 0;
1629 int err = 0;
1630
1631 if (!nfinfo)
1632 goto out;
1633
1634 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1635 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1636 ssp.offset = sizeof(struct nilfs_segment_summary);
1637
1638 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1639 if (bh == sci->sc_super_root)
1640 break;
1641 if (!finfo) {
1642 finfo = nilfs_segctor_map_segsum_entry(
1643 sci, &ssp, sizeof(*finfo));
1644 ino = le64_to_cpu(finfo->fi_ino);
1645 nblocks = le32_to_cpu(finfo->fi_nblocks);
1646 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1647
1648 if (buffer_nilfs_node(bh))
1649 inode = NILFS_BTNC_I(bh->b_page->mapping);
1650 else
1651 inode = NILFS_AS_I(bh->b_page->mapping);
1652
1653 if (mode == SC_LSEG_DSYNC)
1654 sc_op = &nilfs_sc_dsync_ops;
1655 else if (ino == NILFS_DAT_INO)
1656 sc_op = &nilfs_sc_dat_ops;
1657 else /* file blocks */
1658 sc_op = &nilfs_sc_file_ops;
1659 }
1660 bh_org = bh;
1661 get_bh(bh_org);
1662 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1663 &binfo);
1664 if (bh != bh_org)
1665 nilfs_list_replace_buffer(bh_org, bh);
1666 brelse(bh_org);
1667 if (unlikely(err))
1668 goto failed_bmap;
1669
1670 if (ndatablk > 0)
1671 sc_op->write_data_binfo(sci, &ssp, &binfo);
1672 else
1673 sc_op->write_node_binfo(sci, &ssp, &binfo);
1674
1675 blocknr++;
1676 if (--nblocks == 0) {
1677 finfo = NULL;
1678 if (--nfinfo == 0)
1679 break;
1680 } else if (ndatablk > 0)
1681 ndatablk--;
1682 }
1683 out:
1684 return 0;
1685
1686 failed_bmap:
1687 err = nilfs_handle_bmap_error(err, __func__, inode, sci->sc_super);
1688 return err;
1689 }
1690
1691 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1692 {
1693 struct nilfs_segment_buffer *segbuf;
1694 int err;
1695
1696 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1697 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1698 if (unlikely(err))
1699 return err;
1700 nilfs_segbuf_fill_in_segsum(segbuf);
1701 }
1702 return 0;
1703 }
1704
1705 static int
1706 nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out)
1707 {
1708 struct page *clone_page;
1709 struct buffer_head *bh, *head, *bh2;
1710 void *kaddr;
1711
1712 bh = head = page_buffers(page);
1713
1714 clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0);
1715 if (unlikely(!clone_page))
1716 return -ENOMEM;
1717
1718 bh2 = page_buffers(clone_page);
1719 kaddr = kmap_atomic(page, KM_USER0);
1720 do {
1721 if (list_empty(&bh->b_assoc_buffers))
1722 continue;
1723 get_bh(bh2);
1724 page_cache_get(clone_page); /* for each bh */
1725 memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size);
1726 bh2->b_blocknr = bh->b_blocknr;
1727 list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers);
1728 list_add_tail(&bh->b_assoc_buffers, out);
1729 } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head);
1730 kunmap_atomic(kaddr, KM_USER0);
1731
1732 if (!TestSetPageWriteback(clone_page))
1733 inc_zone_page_state(clone_page, NR_WRITEBACK);
1734 unlock_page(clone_page);
1735
1736 return 0;
1737 }
1738
1739 static int nilfs_test_page_to_be_frozen(struct page *page)
1740 {
1741 struct address_space *mapping = page->mapping;
1742
1743 if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode))
1744 return 0;
1745
1746 if (page_mapped(page)) {
1747 ClearPageChecked(page);
1748 return 1;
1749 }
1750 return PageChecked(page);
1751 }
1752
1753 static int nilfs_begin_page_io(struct page *page, struct list_head *out)
1754 {
1755 if (!page || PageWriteback(page))
1756 /* For split b-tree node pages, this function may be called
1757 twice. We ignore the 2nd or later calls by this check. */
1758 return 0;
1759
1760 lock_page(page);
1761 clear_page_dirty_for_io(page);
1762 set_page_writeback(page);
1763 unlock_page(page);
1764
1765 if (nilfs_test_page_to_be_frozen(page)) {
1766 int err = nilfs_copy_replace_page_buffers(page, out);
1767 if (unlikely(err))
1768 return err;
1769 }
1770 return 0;
1771 }
1772
1773 static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
1774 struct page **failed_page)
1775 {
1776 struct nilfs_segment_buffer *segbuf;
1777 struct page *bd_page = NULL, *fs_page = NULL;
1778 struct list_head *list = &sci->sc_copied_buffers;
1779 int err;
1780
1781 *failed_page = NULL;
1782 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1783 struct buffer_head *bh;
1784
1785 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1786 b_assoc_buffers) {
1787 if (bh->b_page != bd_page) {
1788 if (bd_page) {
1789 lock_page(bd_page);
1790 clear_page_dirty_for_io(bd_page);
1791 set_page_writeback(bd_page);
1792 unlock_page(bd_page);
1793 }
1794 bd_page = bh->b_page;
1795 }
1796 }
1797
1798 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1799 b_assoc_buffers) {
1800 if (bh == sci->sc_super_root) {
1801 if (bh->b_page != bd_page) {
1802 lock_page(bd_page);
1803 clear_page_dirty_for_io(bd_page);
1804 set_page_writeback(bd_page);
1805 unlock_page(bd_page);
1806 bd_page = bh->b_page;
1807 }
1808 break;
1809 }
1810 if (bh->b_page != fs_page) {
1811 err = nilfs_begin_page_io(fs_page, list);
1812 if (unlikely(err)) {
1813 *failed_page = fs_page;
1814 goto out;
1815 }
1816 fs_page = bh->b_page;
1817 }
1818 }
1819 }
1820 if (bd_page) {
1821 lock_page(bd_page);
1822 clear_page_dirty_for_io(bd_page);
1823 set_page_writeback(bd_page);
1824 unlock_page(bd_page);
1825 }
1826 err = nilfs_begin_page_io(fs_page, list);
1827 if (unlikely(err))
1828 *failed_page = fs_page;
1829 out:
1830 return err;
1831 }
1832
1833 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1834 struct backing_dev_info *bdi)
1835 {
1836 struct nilfs_segment_buffer *segbuf;
1837 struct nilfs_write_info wi;
1838 int err, res;
1839
1840 wi.sb = sci->sc_super;
1841 wi.bh_sr = sci->sc_super_root;
1842 wi.bdi = bdi;
1843
1844 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1845 nilfs_segbuf_prepare_write(segbuf, &wi);
1846 err = nilfs_segbuf_write(segbuf, &wi);
1847
1848 res = nilfs_segbuf_wait(segbuf, &wi);
1849 err = unlikely(err) ? : res;
1850 if (unlikely(err))
1851 return err;
1852 }
1853 return 0;
1854 }
1855
1856 static int nilfs_page_has_uncleared_buffer(struct page *page)
1857 {
1858 struct buffer_head *head, *bh;
1859
1860 head = bh = page_buffers(page);
1861 do {
1862 if (buffer_dirty(bh) && !list_empty(&bh->b_assoc_buffers))
1863 return 1;
1864 bh = bh->b_this_page;
1865 } while (bh != head);
1866 return 0;
1867 }
1868
1869 static void __nilfs_end_page_io(struct page *page, int err)
1870 {
1871 if (!err) {
1872 if (!nilfs_page_buffers_clean(page))
1873 __set_page_dirty_nobuffers(page);
1874 ClearPageError(page);
1875 } else {
1876 __set_page_dirty_nobuffers(page);
1877 SetPageError(page);
1878 }
1879
1880 if (buffer_nilfs_allocated(page_buffers(page))) {
1881 if (TestClearPageWriteback(page))
1882 dec_zone_page_state(page, NR_WRITEBACK);
1883 } else
1884 end_page_writeback(page);
1885 }
1886
1887 static void nilfs_end_page_io(struct page *page, int err)
1888 {
1889 if (!page)
1890 return;
1891
1892 if (buffer_nilfs_node(page_buffers(page)) &&
1893 nilfs_page_has_uncleared_buffer(page))
1894 /* For b-tree node pages, this function may be called twice
1895 or more because they might be split in a segment.
1896 This check assures that cleanup has been done for all
1897 buffers in a split btnode page. */
1898 return;
1899
1900 __nilfs_end_page_io(page, err);
1901 }
1902
1903 static void nilfs_clear_copied_buffers(struct list_head *list, int err)
1904 {
1905 struct buffer_head *bh, *head;
1906 struct page *page;
1907
1908 while (!list_empty(list)) {
1909 bh = list_entry(list->next, struct buffer_head,
1910 b_assoc_buffers);
1911 page = bh->b_page;
1912 page_cache_get(page);
1913 head = bh = page_buffers(page);
1914 do {
1915 if (!list_empty(&bh->b_assoc_buffers)) {
1916 list_del_init(&bh->b_assoc_buffers);
1917 if (!err) {
1918 set_buffer_uptodate(bh);
1919 clear_buffer_dirty(bh);
1920 clear_buffer_nilfs_volatile(bh);
1921 }
1922 brelse(bh); /* for b_assoc_buffers */
1923 }
1924 } while ((bh = bh->b_this_page) != head);
1925
1926 __nilfs_end_page_io(page, err);
1927 page_cache_release(page);
1928 }
1929 }
1930
1931 static void nilfs_segctor_abort_write(struct nilfs_sc_info *sci,
1932 struct page *failed_page, int err)
1933 {
1934 struct nilfs_segment_buffer *segbuf;
1935 struct page *bd_page = NULL, *fs_page = NULL;
1936
1937 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1938 struct buffer_head *bh;
1939
1940 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1941 b_assoc_buffers) {
1942 if (bh->b_page != bd_page) {
1943 if (bd_page)
1944 end_page_writeback(bd_page);
1945 bd_page = bh->b_page;
1946 }
1947 }
1948
1949 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1950 b_assoc_buffers) {
1951 if (bh == sci->sc_super_root) {
1952 if (bh->b_page != bd_page) {
1953 end_page_writeback(bd_page);
1954 bd_page = bh->b_page;
1955 }
1956 break;
1957 }
1958 if (bh->b_page != fs_page) {
1959 nilfs_end_page_io(fs_page, err);
1960 if (unlikely(fs_page == failed_page))
1961 goto done;
1962 fs_page = bh->b_page;
1963 }
1964 }
1965 }
1966 if (bd_page)
1967 end_page_writeback(bd_page);
1968
1969 nilfs_end_page_io(fs_page, err);
1970 done:
1971 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err);
1972 }
1973
1974 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1975 struct nilfs_segment_buffer *segbuf)
1976 {
1977 nilfs->ns_segnum = segbuf->sb_segnum;
1978 nilfs->ns_nextnum = segbuf->sb_nextnum;
1979 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1980 + segbuf->sb_sum.nblocks;
1981 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1982 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1983 }
1984
1985 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1986 {
1987 struct nilfs_segment_buffer *segbuf;
1988 struct page *bd_page = NULL, *fs_page = NULL;
1989 struct nilfs_sb_info *sbi = sci->sc_sbi;
1990 struct the_nilfs *nilfs = sbi->s_nilfs;
1991 int update_sr = (sci->sc_super_root != NULL);
1992
1993 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1994 struct buffer_head *bh;
1995
1996 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1997 b_assoc_buffers) {
1998 set_buffer_uptodate(bh);
1999 clear_buffer_dirty(bh);
2000 if (bh->b_page != bd_page) {
2001 if (bd_page)
2002 end_page_writeback(bd_page);
2003 bd_page = bh->b_page;
2004 }
2005 }
2006 /*
2007 * We assume that the buffers which belong to the same page
2008 * continue over the buffer list.
2009 * Under this assumption, the last BHs of pages is
2010 * identifiable by the discontinuity of bh->b_page
2011 * (page != fs_page).
2012 *
2013 * For B-tree node blocks, however, this assumption is not
2014 * guaranteed. The cleanup code of B-tree node pages needs
2015 * special care.
2016 */
2017 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
2018 b_assoc_buffers) {
2019 set_buffer_uptodate(bh);
2020 clear_buffer_dirty(bh);
2021 clear_buffer_nilfs_volatile(bh);
2022 if (bh == sci->sc_super_root) {
2023 if (bh->b_page != bd_page) {
2024 end_page_writeback(bd_page);
2025 bd_page = bh->b_page;
2026 }
2027 break;
2028 }
2029 if (bh->b_page != fs_page) {
2030 nilfs_end_page_io(fs_page, 0);
2031 fs_page = bh->b_page;
2032 }
2033 }
2034
2035 if (!NILFS_SEG_SIMPLEX(&segbuf->sb_sum)) {
2036 if (NILFS_SEG_LOGBGN(&segbuf->sb_sum)) {
2037 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
2038 sci->sc_lseg_stime = jiffies;
2039 }
2040 if (NILFS_SEG_LOGEND(&segbuf->sb_sum))
2041 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
2042 }
2043 }
2044 /*
2045 * Since pages may continue over multiple segment buffers,
2046 * end of the last page must be checked outside of the loop.
2047 */
2048 if (bd_page)
2049 end_page_writeback(bd_page);
2050
2051 nilfs_end_page_io(fs_page, 0);
2052
2053 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, 0);
2054
2055 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
2056
2057 if (nilfs_doing_gc()) {
2058 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
2059 if (update_sr)
2060 nilfs_commit_gcdat_inode(nilfs);
2061 } else
2062 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
2063
2064 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
2065
2066 segbuf = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
2067 nilfs_set_next_segment(nilfs, segbuf);
2068
2069 if (update_sr) {
2070 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
2071 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
2072 sbi->s_super->s_dirt = 1;
2073
2074 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
2075 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2076 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
2077 } else
2078 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
2079 }
2080
2081 static int nilfs_segctor_check_in_files(struct nilfs_sc_info *sci,
2082 struct nilfs_sb_info *sbi)
2083 {
2084 struct nilfs_inode_info *ii, *n;
2085 __u64 cno = sbi->s_nilfs->ns_cno;
2086
2087 spin_lock(&sbi->s_inode_lock);
2088 retry:
2089 list_for_each_entry_safe(ii, n, &sbi->s_dirty_files, i_dirty) {
2090 if (!ii->i_bh) {
2091 struct buffer_head *ibh;
2092 int err;
2093
2094 spin_unlock(&sbi->s_inode_lock);
2095 err = nilfs_ifile_get_inode_block(
2096 sbi->s_ifile, ii->vfs_inode.i_ino, &ibh);
2097 if (unlikely(err)) {
2098 nilfs_warning(sbi->s_super, __func__,
2099 "failed to get inode block.\n");
2100 return err;
2101 }
2102 nilfs_mdt_mark_buffer_dirty(ibh);
2103 nilfs_mdt_mark_dirty(sbi->s_ifile);
2104 spin_lock(&sbi->s_inode_lock);
2105 if (likely(!ii->i_bh))
2106 ii->i_bh = ibh;
2107 else
2108 brelse(ibh);
2109 goto retry;
2110 }
2111 ii->i_cno = cno;
2112
2113 clear_bit(NILFS_I_QUEUED, &ii->i_state);
2114 set_bit(NILFS_I_BUSY, &ii->i_state);
2115 list_del(&ii->i_dirty);
2116 list_add_tail(&ii->i_dirty, &sci->sc_dirty_files);
2117 }
2118 spin_unlock(&sbi->s_inode_lock);
2119
2120 NILFS_I(sbi->s_ifile)->i_cno = cno;
2121
2122 return 0;
2123 }
2124
2125 static void nilfs_segctor_check_out_files(struct nilfs_sc_info *sci,
2126 struct nilfs_sb_info *sbi)
2127 {
2128 struct nilfs_transaction_info *ti = current->journal_info;
2129 struct nilfs_inode_info *ii, *n;
2130 __u64 cno = sbi->s_nilfs->ns_cno;
2131
2132 spin_lock(&sbi->s_inode_lock);
2133 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
2134 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
2135 test_bit(NILFS_I_DIRTY, &ii->i_state)) {
2136 /* The current checkpoint number (=nilfs->ns_cno) is
2137 changed between check-in and check-out only if the
2138 super root is written out. So, we can update i_cno
2139 for the inodes that remain in the dirty list. */
2140 ii->i_cno = cno;
2141 continue;
2142 }
2143 clear_bit(NILFS_I_BUSY, &ii->i_state);
2144 brelse(ii->i_bh);
2145 ii->i_bh = NULL;
2146 list_del(&ii->i_dirty);
2147 list_add_tail(&ii->i_dirty, &ti->ti_garbage);
2148 }
2149 spin_unlock(&sbi->s_inode_lock);
2150 }
2151
2152 /*
2153 * Main procedure of segment constructor
2154 */
2155 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2156 {
2157 struct nilfs_sb_info *sbi = sci->sc_sbi;
2158 struct the_nilfs *nilfs = sbi->s_nilfs;
2159 struct page *failed_page;
2160 int err, has_sr = 0;
2161
2162 sci->sc_stage.scnt = NILFS_ST_INIT;
2163
2164 err = nilfs_segctor_check_in_files(sci, sbi);
2165 if (unlikely(err))
2166 goto out;
2167
2168 if (nilfs_test_metadata_dirty(sbi))
2169 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2170
2171 if (nilfs_segctor_clean(sci))
2172 goto out;
2173
2174 do {
2175 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2176
2177 err = nilfs_segctor_begin_construction(sci, nilfs);
2178 if (unlikely(err))
2179 goto out;
2180
2181 /* Update time stamp */
2182 sci->sc_seg_ctime = get_seconds();
2183
2184 err = nilfs_segctor_collect(sci, nilfs, mode);
2185 if (unlikely(err))
2186 goto failed;
2187
2188 has_sr = (sci->sc_super_root != NULL);
2189
2190 /* Avoid empty segment */
2191 if (sci->sc_stage.scnt == NILFS_ST_DONE &&
2192 NILFS_SEG_EMPTY(&sci->sc_curseg->sb_sum)) {
2193 nilfs_segctor_end_construction(sci, nilfs, 1);
2194 goto out;
2195 }
2196
2197 err = nilfs_segctor_assign(sci, mode);
2198 if (unlikely(err))
2199 goto failed;
2200
2201 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2202 nilfs_segctor_fill_in_file_bmap(sci, sbi->s_ifile);
2203
2204 if (has_sr) {
2205 err = nilfs_segctor_fill_in_checkpoint(sci);
2206 if (unlikely(err))
2207 goto failed_to_make_up;
2208
2209 nilfs_segctor_fill_in_super_root(sci, nilfs);
2210 }
2211 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2212
2213 /* Write partial segments */
2214 err = nilfs_segctor_prepare_write(sci, &failed_page);
2215 if (unlikely(err))
2216 goto failed_to_write;
2217
2218 nilfs_segctor_fill_in_checksums(sci, nilfs->ns_crc_seed);
2219
2220 err = nilfs_segctor_write(sci, nilfs->ns_bdi);
2221 if (unlikely(err))
2222 goto failed_to_write;
2223
2224 nilfs_segctor_complete_write(sci);
2225
2226 /* Commit segments */
2227 if (has_sr) {
2228 nilfs_segctor_commit_free_segments(sci);
2229 nilfs_segctor_clear_metadata_dirty(sci);
2230 }
2231
2232 nilfs_segctor_end_construction(sci, nilfs, 0);
2233
2234 } while (sci->sc_stage.scnt != NILFS_ST_DONE);
2235
2236 out:
2237 nilfs_segctor_destroy_segment_buffers(sci);
2238 nilfs_segctor_check_out_files(sci, sbi);
2239 return err;
2240
2241 failed_to_write:
2242 nilfs_segctor_abort_write(sci, failed_page, err);
2243 nilfs_segctor_cancel_segusage(sci, nilfs->ns_sufile);
2244
2245 failed_to_make_up:
2246 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2247 nilfs_redirty_inodes(&sci->sc_dirty_files);
2248
2249 failed:
2250 if (nilfs_doing_gc())
2251 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2252 nilfs_segctor_end_construction(sci, nilfs, err);
2253 goto out;
2254 }
2255
2256 /**
2257 * nilfs_secgtor_start_timer - set timer of background write
2258 * @sci: nilfs_sc_info
2259 *
2260 * If the timer has already been set, it ignores the new request.
2261 * This function MUST be called within a section locking the segment
2262 * semaphore.
2263 */
2264 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2265 {
2266 spin_lock(&sci->sc_state_lock);
2267 if (sci->sc_timer && !(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2268 sci->sc_timer->expires = jiffies + sci->sc_interval;
2269 add_timer(sci->sc_timer);
2270 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2271 }
2272 spin_unlock(&sci->sc_state_lock);
2273 }
2274
2275 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2276 {
2277 spin_lock(&sci->sc_state_lock);
2278 if (!(sci->sc_flush_request & (1 << bn))) {
2279 unsigned long prev_req = sci->sc_flush_request;
2280
2281 sci->sc_flush_request |= (1 << bn);
2282 if (!prev_req)
2283 wake_up(&sci->sc_wait_daemon);
2284 }
2285 spin_unlock(&sci->sc_state_lock);
2286 }
2287
2288 /**
2289 * nilfs_flush_segment - trigger a segment construction for resource control
2290 * @sb: super block
2291 * @ino: inode number of the file to be flushed out.
2292 */
2293 void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2294 {
2295 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2296 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2297
2298 if (!sci || nilfs_doing_construction())
2299 return;
2300 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2301 /* assign bit 0 to data files */
2302 }
2303
2304 int nilfs_segctor_add_segments_to_be_freed(struct nilfs_sc_info *sci,
2305 __u64 *segnum, size_t nsegs)
2306 {
2307 struct nilfs_segment_entry *ent;
2308 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
2309 struct inode *sufile = nilfs->ns_sufile;
2310 LIST_HEAD(list);
2311 __u64 *pnum;
2312 size_t i;
2313 int err;
2314
2315 for (pnum = segnum, i = 0; i < nsegs; pnum++, i++) {
2316 ent = nilfs_alloc_segment_entry(*pnum);
2317 if (unlikely(!ent)) {
2318 err = -ENOMEM;
2319 goto failed;
2320 }
2321 list_add_tail(&ent->list, &list);
2322
2323 err = nilfs_open_segment_entry(ent, sufile);
2324 if (unlikely(err))
2325 goto failed;
2326
2327 if (unlikely(!nilfs_segment_usage_dirty(ent->raw_su)))
2328 printk(KERN_WARNING "NILFS: unused segment is "
2329 "requested to be cleaned (segnum=%llu)\n",
2330 (unsigned long long)ent->segnum);
2331 nilfs_close_segment_entry(ent, sufile);
2332 }
2333 list_splice(&list, sci->sc_cleaning_segments.prev);
2334 return 0;
2335
2336 failed:
2337 nilfs_dispose_segment_list(&list);
2338 return err;
2339 }
2340
2341 void nilfs_segctor_clear_segments_to_be_freed(struct nilfs_sc_info *sci)
2342 {
2343 nilfs_dispose_segment_list(&sci->sc_cleaning_segments);
2344 }
2345
2346 struct nilfs_segctor_wait_request {
2347 wait_queue_t wq;
2348 __u32 seq;
2349 int err;
2350 atomic_t done;
2351 };
2352
2353 static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2354 {
2355 struct nilfs_segctor_wait_request wait_req;
2356 int err = 0;
2357
2358 spin_lock(&sci->sc_state_lock);
2359 init_wait(&wait_req.wq);
2360 wait_req.err = 0;
2361 atomic_set(&wait_req.done, 0);
2362 wait_req.seq = ++sci->sc_seq_request;
2363 spin_unlock(&sci->sc_state_lock);
2364
2365 init_waitqueue_entry(&wait_req.wq, current);
2366 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2367 set_current_state(TASK_INTERRUPTIBLE);
2368 wake_up(&sci->sc_wait_daemon);
2369
2370 for (;;) {
2371 if (atomic_read(&wait_req.done)) {
2372 err = wait_req.err;
2373 break;
2374 }
2375 if (!signal_pending(current)) {
2376 schedule();
2377 continue;
2378 }
2379 err = -ERESTARTSYS;
2380 break;
2381 }
2382 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2383 return err;
2384 }
2385
2386 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2387 {
2388 struct nilfs_segctor_wait_request *wrq, *n;
2389 unsigned long flags;
2390
2391 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2392 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2393 wq.task_list) {
2394 if (!atomic_read(&wrq->done) &&
2395 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2396 wrq->err = err;
2397 atomic_set(&wrq->done, 1);
2398 }
2399 if (atomic_read(&wrq->done)) {
2400 wrq->wq.func(&wrq->wq,
2401 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2402 0, NULL);
2403 }
2404 }
2405 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2406 }
2407
2408 /**
2409 * nilfs_construct_segment - construct a logical segment
2410 * @sb: super block
2411 *
2412 * Return Value: On success, 0 is retured. On errors, one of the following
2413 * negative error code is returned.
2414 *
2415 * %-EROFS - Read only filesystem.
2416 *
2417 * %-EIO - I/O error
2418 *
2419 * %-ENOSPC - No space left on device (only in a panic state).
2420 *
2421 * %-ERESTARTSYS - Interrupted.
2422 *
2423 * %-ENOMEM - Insufficient memory available.
2424 */
2425 int nilfs_construct_segment(struct super_block *sb)
2426 {
2427 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2428 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2429 struct nilfs_transaction_info *ti;
2430 int err;
2431
2432 if (!sci)
2433 return -EROFS;
2434
2435 /* A call inside transactions causes a deadlock. */
2436 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2437
2438 err = nilfs_segctor_sync(sci);
2439 return err;
2440 }
2441
2442 /**
2443 * nilfs_construct_dsync_segment - construct a data-only logical segment
2444 * @sb: super block
2445 * @inode: inode whose data blocks should be written out
2446 * @start: start byte offset
2447 * @end: end byte offset (inclusive)
2448 *
2449 * Return Value: On success, 0 is retured. On errors, one of the following
2450 * negative error code is returned.
2451 *
2452 * %-EROFS - Read only filesystem.
2453 *
2454 * %-EIO - I/O error
2455 *
2456 * %-ENOSPC - No space left on device (only in a panic state).
2457 *
2458 * %-ERESTARTSYS - Interrupted.
2459 *
2460 * %-ENOMEM - Insufficient memory available.
2461 */
2462 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2463 loff_t start, loff_t end)
2464 {
2465 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2466 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2467 struct nilfs_inode_info *ii;
2468 struct nilfs_transaction_info ti;
2469 int err = 0;
2470
2471 if (!sci)
2472 return -EROFS;
2473
2474 nilfs_transaction_lock(sbi, &ti, 0);
2475
2476 ii = NILFS_I(inode);
2477 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
2478 nilfs_test_opt(sbi, STRICT_ORDER) ||
2479 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2480 nilfs_discontinued(sbi->s_nilfs)) {
2481 nilfs_transaction_unlock(sbi);
2482 err = nilfs_segctor_sync(sci);
2483 return err;
2484 }
2485
2486 spin_lock(&sbi->s_inode_lock);
2487 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2488 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2489 spin_unlock(&sbi->s_inode_lock);
2490 nilfs_transaction_unlock(sbi);
2491 return 0;
2492 }
2493 spin_unlock(&sbi->s_inode_lock);
2494 sci->sc_dsync_inode = ii;
2495 sci->sc_dsync_start = start;
2496 sci->sc_dsync_end = end;
2497
2498 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2499
2500 nilfs_transaction_unlock(sbi);
2501 return err;
2502 }
2503
2504 struct nilfs_segctor_req {
2505 int mode;
2506 __u32 seq_accepted;
2507 int sc_err; /* construction failure */
2508 int sb_err; /* super block writeback failure */
2509 };
2510
2511 #define FLUSH_FILE_BIT (0x1) /* data file only */
2512 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2513
2514 static void nilfs_segctor_accept(struct nilfs_sc_info *sci,
2515 struct nilfs_segctor_req *req)
2516 {
2517 req->sc_err = req->sb_err = 0;
2518 spin_lock(&sci->sc_state_lock);
2519 req->seq_accepted = sci->sc_seq_request;
2520 spin_unlock(&sci->sc_state_lock);
2521
2522 if (sci->sc_timer)
2523 del_timer_sync(sci->sc_timer);
2524 }
2525
2526 static void nilfs_segctor_notify(struct nilfs_sc_info *sci,
2527 struct nilfs_segctor_req *req)
2528 {
2529 /* Clear requests (even when the construction failed) */
2530 spin_lock(&sci->sc_state_lock);
2531
2532 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2533
2534 if (req->mode == SC_LSEG_SR) {
2535 sci->sc_seq_done = req->seq_accepted;
2536 nilfs_segctor_wakeup(sci, req->sc_err ? : req->sb_err);
2537 sci->sc_flush_request = 0;
2538 } else if (req->mode == SC_FLUSH_FILE)
2539 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2540 else if (req->mode == SC_FLUSH_DAT)
2541 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2542
2543 spin_unlock(&sci->sc_state_lock);
2544 }
2545
2546 static int nilfs_segctor_construct(struct nilfs_sc_info *sci,
2547 struct nilfs_segctor_req *req)
2548 {
2549 struct nilfs_sb_info *sbi = sci->sc_sbi;
2550 struct the_nilfs *nilfs = sbi->s_nilfs;
2551 int err = 0;
2552
2553 if (nilfs_discontinued(nilfs))
2554 req->mode = SC_LSEG_SR;
2555 if (!nilfs_segctor_confirm(sci)) {
2556 err = nilfs_segctor_do_construct(sci, req->mode);
2557 req->sc_err = err;
2558 }
2559 if (likely(!err)) {
2560 if (req->mode != SC_FLUSH_DAT)
2561 atomic_set(&nilfs->ns_ndirtyblks, 0);
2562 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2563 nilfs_discontinued(nilfs)) {
2564 down_write(&nilfs->ns_sem);
2565 req->sb_err = nilfs_commit_super(sbi, 0);
2566 up_write(&nilfs->ns_sem);
2567 }
2568 }
2569 return err;
2570 }
2571
2572 static void nilfs_construction_timeout(unsigned long data)
2573 {
2574 struct task_struct *p = (struct task_struct *)data;
2575 wake_up_process(p);
2576 }
2577
2578 static void
2579 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2580 {
2581 struct nilfs_inode_info *ii, *n;
2582
2583 list_for_each_entry_safe(ii, n, head, i_dirty) {
2584 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2585 continue;
2586 hlist_del_init(&ii->vfs_inode.i_hash);
2587 list_del_init(&ii->i_dirty);
2588 nilfs_clear_gcinode(&ii->vfs_inode);
2589 }
2590 }
2591
2592 int nilfs_clean_segments(struct super_block *sb, void __user *argp)
2593 {
2594 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2595 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2596 struct the_nilfs *nilfs = sbi->s_nilfs;
2597 struct nilfs_transaction_info ti;
2598 struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
2599 int err;
2600
2601 if (unlikely(!sci))
2602 return -EROFS;
2603
2604 nilfs_transaction_lock(sbi, &ti, 1);
2605
2606 err = nilfs_init_gcdat_inode(nilfs);
2607 if (unlikely(err))
2608 goto out_unlock;
2609 err = nilfs_ioctl_prepare_clean_segments(nilfs, argp);
2610 if (unlikely(err))
2611 goto out_unlock;
2612
2613 list_splice_init(&nilfs->ns_gc_inodes, sci->sc_gc_inodes.prev);
2614
2615 for (;;) {
2616 nilfs_segctor_accept(sci, &req);
2617 err = nilfs_segctor_construct(sci, &req);
2618 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2619 nilfs_segctor_notify(sci, &req);
2620
2621 if (likely(!err))
2622 break;
2623
2624 nilfs_warning(sb, __func__,
2625 "segment construction failed. (err=%d)", err);
2626 set_current_state(TASK_INTERRUPTIBLE);
2627 schedule_timeout(sci->sc_interval);
2628 }
2629
2630 out_unlock:
2631 nilfs_clear_gcdat_inode(nilfs);
2632 nilfs_transaction_unlock(sbi);
2633 return err;
2634 }
2635
2636 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2637 {
2638 struct nilfs_sb_info *sbi = sci->sc_sbi;
2639 struct nilfs_transaction_info ti;
2640 struct nilfs_segctor_req req = { .mode = mode };
2641
2642 nilfs_transaction_lock(sbi, &ti, 0);
2643
2644 nilfs_segctor_accept(sci, &req);
2645 nilfs_segctor_construct(sci, &req);
2646 nilfs_segctor_notify(sci, &req);
2647
2648 /*
2649 * Unclosed segment should be retried. We do this using sc_timer.
2650 * Timeout of sc_timer will invoke complete construction which leads
2651 * to close the current logical segment.
2652 */
2653 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2654 nilfs_segctor_start_timer(sci);
2655
2656 nilfs_transaction_unlock(sbi);
2657 }
2658
2659 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2660 {
2661 int mode = 0;
2662 int err;
2663
2664 spin_lock(&sci->sc_state_lock);
2665 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2666 SC_FLUSH_DAT : SC_FLUSH_FILE;
2667 spin_unlock(&sci->sc_state_lock);
2668
2669 if (mode) {
2670 err = nilfs_segctor_do_construct(sci, mode);
2671
2672 spin_lock(&sci->sc_state_lock);
2673 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2674 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2675 spin_unlock(&sci->sc_state_lock);
2676 }
2677 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2678 }
2679
2680 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2681 {
2682 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2683 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2684 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2685 return SC_FLUSH_FILE;
2686 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2687 return SC_FLUSH_DAT;
2688 }
2689 return SC_LSEG_SR;
2690 }
2691
2692 /**
2693 * nilfs_segctor_thread - main loop of the segment constructor thread.
2694 * @arg: pointer to a struct nilfs_sc_info.
2695 *
2696 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2697 * to execute segment constructions.
2698 */
2699 static int nilfs_segctor_thread(void *arg)
2700 {
2701 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2702 struct timer_list timer;
2703 int timeout = 0;
2704
2705 init_timer(&timer);
2706 timer.data = (unsigned long)current;
2707 timer.function = nilfs_construction_timeout;
2708 sci->sc_timer = &timer;
2709
2710 /* start sync. */
2711 sci->sc_task = current;
2712 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2713 printk(KERN_INFO
2714 "segctord starting. Construction interval = %lu seconds, "
2715 "CP frequency < %lu seconds\n",
2716 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2717
2718 spin_lock(&sci->sc_state_lock);
2719 loop:
2720 for (;;) {
2721 int mode;
2722
2723 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2724 goto end_thread;
2725
2726 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2727 mode = SC_LSEG_SR;
2728 else if (!sci->sc_flush_request)
2729 break;
2730 else
2731 mode = nilfs_segctor_flush_mode(sci);
2732
2733 spin_unlock(&sci->sc_state_lock);
2734 nilfs_segctor_thread_construct(sci, mode);
2735 spin_lock(&sci->sc_state_lock);
2736 timeout = 0;
2737 }
2738
2739
2740 if (freezing(current)) {
2741 spin_unlock(&sci->sc_state_lock);
2742 refrigerator();
2743 spin_lock(&sci->sc_state_lock);
2744 } else {
2745 DEFINE_WAIT(wait);
2746 int should_sleep = 1;
2747
2748 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2749 TASK_INTERRUPTIBLE);
2750
2751 if (sci->sc_seq_request != sci->sc_seq_done)
2752 should_sleep = 0;
2753 else if (sci->sc_flush_request)
2754 should_sleep = 0;
2755 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2756 should_sleep = time_before(jiffies,
2757 sci->sc_timer->expires);
2758
2759 if (should_sleep) {
2760 spin_unlock(&sci->sc_state_lock);
2761 schedule();
2762 spin_lock(&sci->sc_state_lock);
2763 }
2764 finish_wait(&sci->sc_wait_daemon, &wait);
2765 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2766 time_after_eq(jiffies, sci->sc_timer->expires));
2767 }
2768 goto loop;
2769
2770 end_thread:
2771 spin_unlock(&sci->sc_state_lock);
2772 del_timer_sync(sci->sc_timer);
2773 sci->sc_timer = NULL;
2774
2775 /* end sync. */
2776 sci->sc_task = NULL;
2777 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2778 return 0;
2779 }
2780
2781 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2782 {
2783 struct task_struct *t;
2784
2785 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2786 if (IS_ERR(t)) {
2787 int err = PTR_ERR(t);
2788
2789 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2790 err);
2791 return err;
2792 }
2793 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2794 return 0;
2795 }
2796
2797 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2798 {
2799 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2800
2801 while (sci->sc_task) {
2802 wake_up(&sci->sc_wait_daemon);
2803 spin_unlock(&sci->sc_state_lock);
2804 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2805 spin_lock(&sci->sc_state_lock);
2806 }
2807 }
2808
2809 static int nilfs_segctor_init(struct nilfs_sc_info *sci)
2810 {
2811 sci->sc_seq_done = sci->sc_seq_request;
2812
2813 return nilfs_segctor_start_thread(sci);
2814 }
2815
2816 /*
2817 * Setup & clean-up functions
2818 */
2819 static struct nilfs_sc_info *nilfs_segctor_new(struct nilfs_sb_info *sbi)
2820 {
2821 struct nilfs_sc_info *sci;
2822
2823 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2824 if (!sci)
2825 return NULL;
2826
2827 sci->sc_sbi = sbi;
2828 sci->sc_super = sbi->s_super;
2829
2830 init_waitqueue_head(&sci->sc_wait_request);
2831 init_waitqueue_head(&sci->sc_wait_daemon);
2832 init_waitqueue_head(&sci->sc_wait_task);
2833 spin_lock_init(&sci->sc_state_lock);
2834 INIT_LIST_HEAD(&sci->sc_dirty_files);
2835 INIT_LIST_HEAD(&sci->sc_segbufs);
2836 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2837 INIT_LIST_HEAD(&sci->sc_cleaning_segments);
2838 INIT_LIST_HEAD(&sci->sc_copied_buffers);
2839
2840 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2841 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2842 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2843
2844 if (sbi->s_interval)
2845 sci->sc_interval = sbi->s_interval;
2846 if (sbi->s_watermark)
2847 sci->sc_watermark = sbi->s_watermark;
2848 return sci;
2849 }
2850
2851 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2852 {
2853 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2854
2855 /* The segctord thread was stopped and its timer was removed.
2856 But some tasks remain. */
2857 do {
2858 struct nilfs_sb_info *sbi = sci->sc_sbi;
2859 struct nilfs_transaction_info ti;
2860 struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
2861
2862 nilfs_transaction_lock(sbi, &ti, 0);
2863 nilfs_segctor_accept(sci, &req);
2864 ret = nilfs_segctor_construct(sci, &req);
2865 nilfs_segctor_notify(sci, &req);
2866 nilfs_transaction_unlock(sbi);
2867
2868 } while (ret && retrycount-- > 0);
2869 }
2870
2871 /**
2872 * nilfs_segctor_destroy - destroy the segment constructor.
2873 * @sci: nilfs_sc_info
2874 *
2875 * nilfs_segctor_destroy() kills the segctord thread and frees
2876 * the nilfs_sc_info struct.
2877 * Caller must hold the segment semaphore.
2878 */
2879 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2880 {
2881 struct nilfs_sb_info *sbi = sci->sc_sbi;
2882 int flag;
2883
2884 up_write(&sbi->s_nilfs->ns_segctor_sem);
2885
2886 spin_lock(&sci->sc_state_lock);
2887 nilfs_segctor_kill_thread(sci);
2888 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2889 || sci->sc_seq_request != sci->sc_seq_done);
2890 spin_unlock(&sci->sc_state_lock);
2891
2892 if (flag || nilfs_segctor_confirm(sci))
2893 nilfs_segctor_write_out(sci);
2894
2895 WARN_ON(!list_empty(&sci->sc_copied_buffers));
2896
2897 if (!list_empty(&sci->sc_dirty_files)) {
2898 nilfs_warning(sbi->s_super, __func__,
2899 "dirty file(s) after the final construction\n");
2900 nilfs_dispose_list(sbi, &sci->sc_dirty_files, 1);
2901 }
2902
2903 if (!list_empty(&sci->sc_cleaning_segments))
2904 nilfs_dispose_segment_list(&sci->sc_cleaning_segments);
2905
2906 WARN_ON(!list_empty(&sci->sc_segbufs));
2907
2908 down_write(&sbi->s_nilfs->ns_segctor_sem);
2909
2910 kfree(sci);
2911 }
2912
2913 /**
2914 * nilfs_attach_segment_constructor - attach a segment constructor
2915 * @sbi: nilfs_sb_info
2916 *
2917 * nilfs_attach_segment_constructor() allocates a struct nilfs_sc_info,
2918 * initilizes it, and starts the segment constructor.
2919 *
2920 * Return Value: On success, 0 is returned. On error, one of the following
2921 * negative error code is returned.
2922 *
2923 * %-ENOMEM - Insufficient memory available.
2924 */
2925 int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi)
2926 {
2927 struct the_nilfs *nilfs = sbi->s_nilfs;
2928 int err;
2929
2930 /* Each field of nilfs_segctor is cleared through the initialization
2931 of super-block info */
2932 sbi->s_sc_info = nilfs_segctor_new(sbi);
2933 if (!sbi->s_sc_info)
2934 return -ENOMEM;
2935
2936 nilfs_attach_writer(nilfs, sbi);
2937 err = nilfs_segctor_init(NILFS_SC(sbi));
2938 if (err) {
2939 nilfs_detach_writer(nilfs, sbi);
2940 kfree(sbi->s_sc_info);
2941 sbi->s_sc_info = NULL;
2942 }
2943 return err;
2944 }
2945
2946 /**
2947 * nilfs_detach_segment_constructor - destroy the segment constructor
2948 * @sbi: nilfs_sb_info
2949 *
2950 * nilfs_detach_segment_constructor() kills the segment constructor daemon,
2951 * frees the struct nilfs_sc_info, and destroy the dirty file list.
2952 */
2953 void nilfs_detach_segment_constructor(struct nilfs_sb_info *sbi)
2954 {
2955 struct the_nilfs *nilfs = sbi->s_nilfs;
2956 LIST_HEAD(garbage_list);
2957
2958 down_write(&nilfs->ns_segctor_sem);
2959 if (NILFS_SC(sbi)) {
2960 nilfs_segctor_destroy(NILFS_SC(sbi));
2961 sbi->s_sc_info = NULL;
2962 }
2963
2964 /* Force to free the list of dirty files */
2965 spin_lock(&sbi->s_inode_lock);
2966 if (!list_empty(&sbi->s_dirty_files)) {
2967 list_splice_init(&sbi->s_dirty_files, &garbage_list);
2968 nilfs_warning(sbi->s_super, __func__,
2969 "Non empty dirty list after the last "
2970 "segment construction\n");
2971 }
2972 spin_unlock(&sbi->s_inode_lock);
2973 up_write(&nilfs->ns_segctor_sem);
2974
2975 nilfs_dispose_list(sbi, &garbage_list, 1);
2976 nilfs_detach_writer(nilfs, sbi);
2977 }
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