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Merge branch 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied...
[GitHub/mt8127/android_kernel_alcatel_ttab.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 "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_write_inode_common(nilfs_dat_inode(nilfs), (void *)raw_sr +
978 NILFS_SR_DAT_OFFSET(isz), 1);
979 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
980 NILFS_SR_CPFILE_OFFSET(isz), 1);
981 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
982 NILFS_SR_SUFILE_OFFSET(isz), 1);
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 /**
1277 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1278 * @sci: nilfs_sc_info
1279 * @nilfs: nilfs object
1280 */
1281 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1282 struct the_nilfs *nilfs)
1283 {
1284 struct nilfs_segment_buffer *segbuf, *prev;
1285 __u64 nextnum;
1286 int err, alloc = 0;
1287
1288 segbuf = nilfs_segbuf_new(sci->sc_super);
1289 if (unlikely(!segbuf))
1290 return -ENOMEM;
1291
1292 if (list_empty(&sci->sc_write_logs)) {
1293 nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1294 nilfs->ns_pseg_offset, nilfs);
1295 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1296 nilfs_shift_to_next_segment(nilfs);
1297 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1298 }
1299
1300 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1301 nextnum = nilfs->ns_nextnum;
1302
1303 if (nilfs->ns_segnum == nilfs->ns_nextnum)
1304 /* Start from the head of a new full segment */
1305 alloc++;
1306 } else {
1307 /* Continue logs */
1308 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1309 nilfs_segbuf_map_cont(segbuf, prev);
1310 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1311 nextnum = prev->sb_nextnum;
1312
1313 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1314 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1315 segbuf->sb_sum.seg_seq++;
1316 alloc++;
1317 }
1318 }
1319
1320 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1321 if (err)
1322 goto failed;
1323
1324 if (alloc) {
1325 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1326 if (err)
1327 goto failed;
1328 }
1329 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1330
1331 BUG_ON(!list_empty(&sci->sc_segbufs));
1332 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1333 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1334 return 0;
1335
1336 failed:
1337 nilfs_segbuf_free(segbuf);
1338 return err;
1339 }
1340
1341 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1342 struct the_nilfs *nilfs, int nadd)
1343 {
1344 struct nilfs_segment_buffer *segbuf, *prev;
1345 struct inode *sufile = nilfs->ns_sufile;
1346 __u64 nextnextnum;
1347 LIST_HEAD(list);
1348 int err, ret, i;
1349
1350 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1351 /*
1352 * Since the segment specified with nextnum might be allocated during
1353 * the previous construction, the buffer including its segusage may
1354 * not be dirty. The following call ensures that the buffer is dirty
1355 * and will pin the buffer on memory until the sufile is written.
1356 */
1357 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1358 if (unlikely(err))
1359 return err;
1360
1361 for (i = 0; i < nadd; i++) {
1362 /* extend segment info */
1363 err = -ENOMEM;
1364 segbuf = nilfs_segbuf_new(sci->sc_super);
1365 if (unlikely(!segbuf))
1366 goto failed;
1367
1368 /* map this buffer to region of segment on-disk */
1369 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1370 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1371
1372 /* allocate the next next full segment */
1373 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1374 if (unlikely(err))
1375 goto failed_segbuf;
1376
1377 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1378 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1379
1380 list_add_tail(&segbuf->sb_list, &list);
1381 prev = segbuf;
1382 }
1383 list_splice_tail(&list, &sci->sc_segbufs);
1384 return 0;
1385
1386 failed_segbuf:
1387 nilfs_segbuf_free(segbuf);
1388 failed:
1389 list_for_each_entry(segbuf, &list, sb_list) {
1390 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1391 WARN_ON(ret); /* never fails */
1392 }
1393 nilfs_destroy_logs(&list);
1394 return err;
1395 }
1396
1397 static void nilfs_free_incomplete_logs(struct list_head *logs,
1398 struct the_nilfs *nilfs)
1399 {
1400 struct nilfs_segment_buffer *segbuf, *prev;
1401 struct inode *sufile = nilfs->ns_sufile;
1402 int ret;
1403
1404 segbuf = NILFS_FIRST_SEGBUF(logs);
1405 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1406 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1407 WARN_ON(ret); /* never fails */
1408 }
1409 if (atomic_read(&segbuf->sb_err)) {
1410 /* Case 1: The first segment failed */
1411 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1412 /* Case 1a: Partial segment appended into an existing
1413 segment */
1414 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1415 segbuf->sb_fseg_end);
1416 else /* Case 1b: New full segment */
1417 set_nilfs_discontinued(nilfs);
1418 }
1419
1420 prev = segbuf;
1421 list_for_each_entry_continue(segbuf, logs, sb_list) {
1422 if (prev->sb_nextnum != segbuf->sb_nextnum) {
1423 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1424 WARN_ON(ret); /* never fails */
1425 }
1426 if (atomic_read(&segbuf->sb_err) &&
1427 segbuf->sb_segnum != nilfs->ns_nextnum)
1428 /* Case 2: extended segment (!= next) failed */
1429 nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1430 prev = segbuf;
1431 }
1432 }
1433
1434 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1435 struct inode *sufile)
1436 {
1437 struct nilfs_segment_buffer *segbuf;
1438 unsigned long live_blocks;
1439 int ret;
1440
1441 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1442 live_blocks = segbuf->sb_sum.nblocks +
1443 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1444 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1445 live_blocks,
1446 sci->sc_seg_ctime);
1447 WARN_ON(ret); /* always succeed because the segusage is dirty */
1448 }
1449 }
1450
1451 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1452 {
1453 struct nilfs_segment_buffer *segbuf;
1454 int ret;
1455
1456 segbuf = NILFS_FIRST_SEGBUF(logs);
1457 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1458 segbuf->sb_pseg_start -
1459 segbuf->sb_fseg_start, 0);
1460 WARN_ON(ret); /* always succeed because the segusage is dirty */
1461
1462 list_for_each_entry_continue(segbuf, logs, sb_list) {
1463 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1464 0, 0);
1465 WARN_ON(ret); /* always succeed */
1466 }
1467 }
1468
1469 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1470 struct nilfs_segment_buffer *last,
1471 struct inode *sufile)
1472 {
1473 struct nilfs_segment_buffer *segbuf = last;
1474 int ret;
1475
1476 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1477 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1478 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1479 WARN_ON(ret);
1480 }
1481 nilfs_truncate_logs(&sci->sc_segbufs, last);
1482 }
1483
1484
1485 static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1486 struct the_nilfs *nilfs, int mode)
1487 {
1488 struct nilfs_cstage prev_stage = sci->sc_stage;
1489 int err, nadd = 1;
1490
1491 /* Collection retry loop */
1492 for (;;) {
1493 sci->sc_super_root = NULL;
1494 sci->sc_nblk_this_inc = 0;
1495 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1496
1497 err = nilfs_segctor_reset_segment_buffer(sci);
1498 if (unlikely(err))
1499 goto failed;
1500
1501 err = nilfs_segctor_collect_blocks(sci, mode);
1502 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1503 if (!err)
1504 break;
1505
1506 if (unlikely(err != -E2BIG))
1507 goto failed;
1508
1509 /* The current segment is filled up */
1510 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
1511 break;
1512
1513 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1514 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1515 sci->sc_freesegs,
1516 sci->sc_nfreesegs,
1517 NULL);
1518 WARN_ON(err); /* do not happen */
1519 }
1520 nilfs_clear_logs(&sci->sc_segbufs);
1521
1522 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1523 if (unlikely(err))
1524 return err;
1525
1526 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1527 sci->sc_stage = prev_stage;
1528 }
1529 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1530 return 0;
1531
1532 failed:
1533 return err;
1534 }
1535
1536 static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1537 struct buffer_head *new_bh)
1538 {
1539 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1540
1541 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1542 /* The caller must release old_bh */
1543 }
1544
1545 static int
1546 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1547 struct nilfs_segment_buffer *segbuf,
1548 int mode)
1549 {
1550 struct inode *inode = NULL;
1551 sector_t blocknr;
1552 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1553 unsigned long nblocks = 0, ndatablk = 0;
1554 struct nilfs_sc_operations *sc_op = NULL;
1555 struct nilfs_segsum_pointer ssp;
1556 struct nilfs_finfo *finfo = NULL;
1557 union nilfs_binfo binfo;
1558 struct buffer_head *bh, *bh_org;
1559 ino_t ino = 0;
1560 int err = 0;
1561
1562 if (!nfinfo)
1563 goto out;
1564
1565 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1566 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1567 ssp.offset = sizeof(struct nilfs_segment_summary);
1568
1569 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1570 if (bh == sci->sc_super_root)
1571 break;
1572 if (!finfo) {
1573 finfo = nilfs_segctor_map_segsum_entry(
1574 sci, &ssp, sizeof(*finfo));
1575 ino = le64_to_cpu(finfo->fi_ino);
1576 nblocks = le32_to_cpu(finfo->fi_nblocks);
1577 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1578
1579 if (buffer_nilfs_node(bh))
1580 inode = NILFS_BTNC_I(bh->b_page->mapping);
1581 else
1582 inode = NILFS_AS_I(bh->b_page->mapping);
1583
1584 if (mode == SC_LSEG_DSYNC)
1585 sc_op = &nilfs_sc_dsync_ops;
1586 else if (ino == NILFS_DAT_INO)
1587 sc_op = &nilfs_sc_dat_ops;
1588 else /* file blocks */
1589 sc_op = &nilfs_sc_file_ops;
1590 }
1591 bh_org = bh;
1592 get_bh(bh_org);
1593 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1594 &binfo);
1595 if (bh != bh_org)
1596 nilfs_list_replace_buffer(bh_org, bh);
1597 brelse(bh_org);
1598 if (unlikely(err))
1599 goto failed_bmap;
1600
1601 if (ndatablk > 0)
1602 sc_op->write_data_binfo(sci, &ssp, &binfo);
1603 else
1604 sc_op->write_node_binfo(sci, &ssp, &binfo);
1605
1606 blocknr++;
1607 if (--nblocks == 0) {
1608 finfo = NULL;
1609 if (--nfinfo == 0)
1610 break;
1611 } else if (ndatablk > 0)
1612 ndatablk--;
1613 }
1614 out:
1615 return 0;
1616
1617 failed_bmap:
1618 err = nilfs_handle_bmap_error(err, __func__, inode, sci->sc_super);
1619 return err;
1620 }
1621
1622 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1623 {
1624 struct nilfs_segment_buffer *segbuf;
1625 int err;
1626
1627 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1628 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1629 if (unlikely(err))
1630 return err;
1631 nilfs_segbuf_fill_in_segsum(segbuf);
1632 }
1633 return 0;
1634 }
1635
1636 static int
1637 nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out)
1638 {
1639 struct page *clone_page;
1640 struct buffer_head *bh, *head, *bh2;
1641 void *kaddr;
1642
1643 bh = head = page_buffers(page);
1644
1645 clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0);
1646 if (unlikely(!clone_page))
1647 return -ENOMEM;
1648
1649 bh2 = page_buffers(clone_page);
1650 kaddr = kmap_atomic(page, KM_USER0);
1651 do {
1652 if (list_empty(&bh->b_assoc_buffers))
1653 continue;
1654 get_bh(bh2);
1655 page_cache_get(clone_page); /* for each bh */
1656 memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size);
1657 bh2->b_blocknr = bh->b_blocknr;
1658 list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers);
1659 list_add_tail(&bh->b_assoc_buffers, out);
1660 } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head);
1661 kunmap_atomic(kaddr, KM_USER0);
1662
1663 if (!TestSetPageWriteback(clone_page))
1664 inc_zone_page_state(clone_page, NR_WRITEBACK);
1665 unlock_page(clone_page);
1666
1667 return 0;
1668 }
1669
1670 static int nilfs_test_page_to_be_frozen(struct page *page)
1671 {
1672 struct address_space *mapping = page->mapping;
1673
1674 if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode))
1675 return 0;
1676
1677 if (page_mapped(page)) {
1678 ClearPageChecked(page);
1679 return 1;
1680 }
1681 return PageChecked(page);
1682 }
1683
1684 static int nilfs_begin_page_io(struct page *page, struct list_head *out)
1685 {
1686 if (!page || PageWriteback(page))
1687 /* For split b-tree node pages, this function may be called
1688 twice. We ignore the 2nd or later calls by this check. */
1689 return 0;
1690
1691 lock_page(page);
1692 clear_page_dirty_for_io(page);
1693 set_page_writeback(page);
1694 unlock_page(page);
1695
1696 if (nilfs_test_page_to_be_frozen(page)) {
1697 int err = nilfs_copy_replace_page_buffers(page, out);
1698 if (unlikely(err))
1699 return err;
1700 }
1701 return 0;
1702 }
1703
1704 static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
1705 struct page **failed_page)
1706 {
1707 struct nilfs_segment_buffer *segbuf;
1708 struct page *bd_page = NULL, *fs_page = NULL;
1709 struct list_head *list = &sci->sc_copied_buffers;
1710 int err;
1711
1712 *failed_page = NULL;
1713 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1714 struct buffer_head *bh;
1715
1716 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1717 b_assoc_buffers) {
1718 if (bh->b_page != bd_page) {
1719 if (bd_page) {
1720 lock_page(bd_page);
1721 clear_page_dirty_for_io(bd_page);
1722 set_page_writeback(bd_page);
1723 unlock_page(bd_page);
1724 }
1725 bd_page = bh->b_page;
1726 }
1727 }
1728
1729 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1730 b_assoc_buffers) {
1731 if (bh == sci->sc_super_root) {
1732 if (bh->b_page != bd_page) {
1733 lock_page(bd_page);
1734 clear_page_dirty_for_io(bd_page);
1735 set_page_writeback(bd_page);
1736 unlock_page(bd_page);
1737 bd_page = bh->b_page;
1738 }
1739 break;
1740 }
1741 if (bh->b_page != fs_page) {
1742 err = nilfs_begin_page_io(fs_page, list);
1743 if (unlikely(err)) {
1744 *failed_page = fs_page;
1745 goto out;
1746 }
1747 fs_page = bh->b_page;
1748 }
1749 }
1750 }
1751 if (bd_page) {
1752 lock_page(bd_page);
1753 clear_page_dirty_for_io(bd_page);
1754 set_page_writeback(bd_page);
1755 unlock_page(bd_page);
1756 }
1757 err = nilfs_begin_page_io(fs_page, list);
1758 if (unlikely(err))
1759 *failed_page = fs_page;
1760 out:
1761 return err;
1762 }
1763
1764 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1765 struct the_nilfs *nilfs)
1766 {
1767 int ret;
1768
1769 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1770 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1771 return ret;
1772 }
1773
1774 static void __nilfs_end_page_io(struct page *page, int err)
1775 {
1776 if (!err) {
1777 if (!nilfs_page_buffers_clean(page))
1778 __set_page_dirty_nobuffers(page);
1779 ClearPageError(page);
1780 } else {
1781 __set_page_dirty_nobuffers(page);
1782 SetPageError(page);
1783 }
1784
1785 if (buffer_nilfs_allocated(page_buffers(page))) {
1786 if (TestClearPageWriteback(page))
1787 dec_zone_page_state(page, NR_WRITEBACK);
1788 } else
1789 end_page_writeback(page);
1790 }
1791
1792 static void nilfs_end_page_io(struct page *page, int err)
1793 {
1794 if (!page)
1795 return;
1796
1797 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
1798 /*
1799 * For b-tree node pages, this function may be called twice
1800 * or more because they might be split in a segment.
1801 */
1802 if (PageDirty(page)) {
1803 /*
1804 * For pages holding split b-tree node buffers, dirty
1805 * flag on the buffers may be cleared discretely.
1806 * In that case, the page is once redirtied for
1807 * remaining buffers, and it must be cancelled if
1808 * all the buffers get cleaned later.
1809 */
1810 lock_page(page);
1811 if (nilfs_page_buffers_clean(page))
1812 __nilfs_clear_page_dirty(page);
1813 unlock_page(page);
1814 }
1815 return;
1816 }
1817
1818 __nilfs_end_page_io(page, err);
1819 }
1820
1821 static void nilfs_clear_copied_buffers(struct list_head *list, int err)
1822 {
1823 struct buffer_head *bh, *head;
1824 struct page *page;
1825
1826 while (!list_empty(list)) {
1827 bh = list_entry(list->next, struct buffer_head,
1828 b_assoc_buffers);
1829 page = bh->b_page;
1830 page_cache_get(page);
1831 head = bh = page_buffers(page);
1832 do {
1833 if (!list_empty(&bh->b_assoc_buffers)) {
1834 list_del_init(&bh->b_assoc_buffers);
1835 if (!err) {
1836 set_buffer_uptodate(bh);
1837 clear_buffer_dirty(bh);
1838 clear_buffer_nilfs_volatile(bh);
1839 }
1840 brelse(bh); /* for b_assoc_buffers */
1841 }
1842 } while ((bh = bh->b_this_page) != head);
1843
1844 __nilfs_end_page_io(page, err);
1845 page_cache_release(page);
1846 }
1847 }
1848
1849 static void nilfs_abort_logs(struct list_head *logs, struct page *failed_page,
1850 struct buffer_head *bh_sr, int err)
1851 {
1852 struct nilfs_segment_buffer *segbuf;
1853 struct page *bd_page = NULL, *fs_page = NULL;
1854 struct buffer_head *bh;
1855
1856 if (list_empty(logs))
1857 return;
1858
1859 list_for_each_entry(segbuf, logs, sb_list) {
1860 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1861 b_assoc_buffers) {
1862 if (bh->b_page != bd_page) {
1863 if (bd_page)
1864 end_page_writeback(bd_page);
1865 bd_page = bh->b_page;
1866 }
1867 }
1868
1869 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1870 b_assoc_buffers) {
1871 if (bh == bh_sr) {
1872 if (bh->b_page != bd_page) {
1873 end_page_writeback(bd_page);
1874 bd_page = bh->b_page;
1875 }
1876 break;
1877 }
1878 if (bh->b_page != fs_page) {
1879 nilfs_end_page_io(fs_page, err);
1880 if (fs_page && fs_page == failed_page)
1881 return;
1882 fs_page = bh->b_page;
1883 }
1884 }
1885 }
1886 if (bd_page)
1887 end_page_writeback(bd_page);
1888
1889 nilfs_end_page_io(fs_page, err);
1890 }
1891
1892 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1893 struct the_nilfs *nilfs, int err)
1894 {
1895 LIST_HEAD(logs);
1896 int ret;
1897
1898 list_splice_tail_init(&sci->sc_write_logs, &logs);
1899 ret = nilfs_wait_on_logs(&logs);
1900 if (ret)
1901 nilfs_abort_logs(&logs, NULL, sci->sc_super_root, ret);
1902
1903 list_splice_tail_init(&sci->sc_segbufs, &logs);
1904 nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1905 nilfs_free_incomplete_logs(&logs, nilfs);
1906 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err);
1907
1908 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1909 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1910 sci->sc_freesegs,
1911 sci->sc_nfreesegs,
1912 NULL);
1913 WARN_ON(ret); /* do not happen */
1914 }
1915
1916 nilfs_destroy_logs(&logs);
1917 sci->sc_super_root = NULL;
1918 }
1919
1920 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1921 struct nilfs_segment_buffer *segbuf)
1922 {
1923 nilfs->ns_segnum = segbuf->sb_segnum;
1924 nilfs->ns_nextnum = segbuf->sb_nextnum;
1925 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1926 + segbuf->sb_sum.nblocks;
1927 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1928 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1929 }
1930
1931 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1932 {
1933 struct nilfs_segment_buffer *segbuf;
1934 struct page *bd_page = NULL, *fs_page = NULL;
1935 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
1936 int update_sr = (sci->sc_super_root != NULL);
1937
1938 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1939 struct buffer_head *bh;
1940
1941 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1942 b_assoc_buffers) {
1943 set_buffer_uptodate(bh);
1944 clear_buffer_dirty(bh);
1945 if (bh->b_page != bd_page) {
1946 if (bd_page)
1947 end_page_writeback(bd_page);
1948 bd_page = bh->b_page;
1949 }
1950 }
1951 /*
1952 * We assume that the buffers which belong to the same page
1953 * continue over the buffer list.
1954 * Under this assumption, the last BHs of pages is
1955 * identifiable by the discontinuity of bh->b_page
1956 * (page != fs_page).
1957 *
1958 * For B-tree node blocks, however, this assumption is not
1959 * guaranteed. The cleanup code of B-tree node pages needs
1960 * special care.
1961 */
1962 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1963 b_assoc_buffers) {
1964 set_buffer_uptodate(bh);
1965 clear_buffer_dirty(bh);
1966 clear_buffer_nilfs_volatile(bh);
1967 if (bh == sci->sc_super_root) {
1968 if (bh->b_page != bd_page) {
1969 end_page_writeback(bd_page);
1970 bd_page = bh->b_page;
1971 }
1972 break;
1973 }
1974 if (bh->b_page != fs_page) {
1975 nilfs_end_page_io(fs_page, 0);
1976 fs_page = bh->b_page;
1977 }
1978 }
1979
1980 if (!NILFS_SEG_SIMPLEX(&segbuf->sb_sum)) {
1981 if (NILFS_SEG_LOGBGN(&segbuf->sb_sum)) {
1982 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1983 sci->sc_lseg_stime = jiffies;
1984 }
1985 if (NILFS_SEG_LOGEND(&segbuf->sb_sum))
1986 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1987 }
1988 }
1989 /*
1990 * Since pages may continue over multiple segment buffers,
1991 * end of the last page must be checked outside of the loop.
1992 */
1993 if (bd_page)
1994 end_page_writeback(bd_page);
1995
1996 nilfs_end_page_io(fs_page, 0);
1997
1998 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, 0);
1999
2000 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
2001
2002 if (nilfs_doing_gc()) {
2003 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
2004 if (update_sr)
2005 nilfs_commit_gcdat_inode(nilfs);
2006 } else
2007 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
2008
2009 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
2010
2011 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
2012 nilfs_set_next_segment(nilfs, segbuf);
2013
2014 if (update_sr) {
2015 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
2016 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
2017 set_nilfs_sb_dirty(nilfs);
2018
2019 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
2020 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2021 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
2022 nilfs_segctor_clear_metadata_dirty(sci);
2023 } else
2024 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
2025 }
2026
2027 static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
2028 {
2029 int ret;
2030
2031 ret = nilfs_wait_on_logs(&sci->sc_write_logs);
2032 if (!ret) {
2033 nilfs_segctor_complete_write(sci);
2034 nilfs_destroy_logs(&sci->sc_write_logs);
2035 }
2036 return ret;
2037 }
2038
2039 static int nilfs_segctor_check_in_files(struct nilfs_sc_info *sci,
2040 struct nilfs_sb_info *sbi)
2041 {
2042 struct nilfs_inode_info *ii, *n;
2043 __u64 cno = sbi->s_nilfs->ns_cno;
2044
2045 spin_lock(&sbi->s_inode_lock);
2046 retry:
2047 list_for_each_entry_safe(ii, n, &sbi->s_dirty_files, i_dirty) {
2048 if (!ii->i_bh) {
2049 struct buffer_head *ibh;
2050 int err;
2051
2052 spin_unlock(&sbi->s_inode_lock);
2053 err = nilfs_ifile_get_inode_block(
2054 sbi->s_ifile, ii->vfs_inode.i_ino, &ibh);
2055 if (unlikely(err)) {
2056 nilfs_warning(sbi->s_super, __func__,
2057 "failed to get inode block.\n");
2058 return err;
2059 }
2060 nilfs_mdt_mark_buffer_dirty(ibh);
2061 nilfs_mdt_mark_dirty(sbi->s_ifile);
2062 spin_lock(&sbi->s_inode_lock);
2063 if (likely(!ii->i_bh))
2064 ii->i_bh = ibh;
2065 else
2066 brelse(ibh);
2067 goto retry;
2068 }
2069 ii->i_cno = cno;
2070
2071 clear_bit(NILFS_I_QUEUED, &ii->i_state);
2072 set_bit(NILFS_I_BUSY, &ii->i_state);
2073 list_del(&ii->i_dirty);
2074 list_add_tail(&ii->i_dirty, &sci->sc_dirty_files);
2075 }
2076 spin_unlock(&sbi->s_inode_lock);
2077
2078 NILFS_I(sbi->s_ifile)->i_cno = cno;
2079
2080 return 0;
2081 }
2082
2083 static void nilfs_segctor_check_out_files(struct nilfs_sc_info *sci,
2084 struct nilfs_sb_info *sbi)
2085 {
2086 struct nilfs_transaction_info *ti = current->journal_info;
2087 struct nilfs_inode_info *ii, *n;
2088 __u64 cno = sbi->s_nilfs->ns_cno;
2089
2090 spin_lock(&sbi->s_inode_lock);
2091 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
2092 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
2093 test_bit(NILFS_I_DIRTY, &ii->i_state)) {
2094 /* The current checkpoint number (=nilfs->ns_cno) is
2095 changed between check-in and check-out only if the
2096 super root is written out. So, we can update i_cno
2097 for the inodes that remain in the dirty list. */
2098 ii->i_cno = cno;
2099 continue;
2100 }
2101 clear_bit(NILFS_I_BUSY, &ii->i_state);
2102 brelse(ii->i_bh);
2103 ii->i_bh = NULL;
2104 list_del(&ii->i_dirty);
2105 list_add_tail(&ii->i_dirty, &ti->ti_garbage);
2106 }
2107 spin_unlock(&sbi->s_inode_lock);
2108 }
2109
2110 /*
2111 * Main procedure of segment constructor
2112 */
2113 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2114 {
2115 struct nilfs_sb_info *sbi = sci->sc_sbi;
2116 struct the_nilfs *nilfs = sbi->s_nilfs;
2117 struct page *failed_page;
2118 int err, has_sr = 0;
2119
2120 sci->sc_stage.scnt = NILFS_ST_INIT;
2121
2122 err = nilfs_segctor_check_in_files(sci, sbi);
2123 if (unlikely(err))
2124 goto out;
2125
2126 if (nilfs_test_metadata_dirty(sbi))
2127 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2128
2129 if (nilfs_segctor_clean(sci))
2130 goto out;
2131
2132 do {
2133 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2134
2135 err = nilfs_segctor_begin_construction(sci, nilfs);
2136 if (unlikely(err))
2137 goto out;
2138
2139 /* Update time stamp */
2140 sci->sc_seg_ctime = get_seconds();
2141
2142 err = nilfs_segctor_collect(sci, nilfs, mode);
2143 if (unlikely(err))
2144 goto failed;
2145
2146 has_sr = (sci->sc_super_root != NULL);
2147
2148 /* Avoid empty segment */
2149 if (sci->sc_stage.scnt == NILFS_ST_DONE &&
2150 NILFS_SEG_EMPTY(&sci->sc_curseg->sb_sum)) {
2151 nilfs_segctor_abort_construction(sci, nilfs, 1);
2152 goto out;
2153 }
2154
2155 err = nilfs_segctor_assign(sci, mode);
2156 if (unlikely(err))
2157 goto failed;
2158
2159 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2160 nilfs_segctor_fill_in_file_bmap(sci, sbi->s_ifile);
2161
2162 if (has_sr) {
2163 err = nilfs_segctor_fill_in_checkpoint(sci);
2164 if (unlikely(err))
2165 goto failed_to_write;
2166
2167 nilfs_segctor_fill_in_super_root(sci, nilfs);
2168 }
2169 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2170
2171 /* Write partial segments */
2172 err = nilfs_segctor_prepare_write(sci, &failed_page);
2173 if (err) {
2174 nilfs_abort_logs(&sci->sc_segbufs, failed_page,
2175 sci->sc_super_root, err);
2176 goto failed_to_write;
2177 }
2178 nilfs_segctor_fill_in_checksums(sci, nilfs->ns_crc_seed);
2179
2180 err = nilfs_segctor_write(sci, nilfs);
2181 if (unlikely(err))
2182 goto failed_to_write;
2183
2184 if (sci->sc_stage.scnt == NILFS_ST_DONE ||
2185 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
2186 /*
2187 * At this point, we avoid double buffering
2188 * for blocksize < pagesize because page dirty
2189 * flag is turned off during write and dirty
2190 * buffers are not properly collected for
2191 * pages crossing over segments.
2192 */
2193 err = nilfs_segctor_wait(sci);
2194 if (err)
2195 goto failed_to_write;
2196 }
2197 } while (sci->sc_stage.scnt != NILFS_ST_DONE);
2198
2199 sci->sc_super_root = NULL;
2200
2201 out:
2202 nilfs_segctor_check_out_files(sci, sbi);
2203 return err;
2204
2205 failed_to_write:
2206 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2207 nilfs_redirty_inodes(&sci->sc_dirty_files);
2208
2209 failed:
2210 if (nilfs_doing_gc())
2211 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2212 nilfs_segctor_abort_construction(sci, nilfs, err);
2213 goto out;
2214 }
2215
2216 /**
2217 * nilfs_secgtor_start_timer - set timer of background write
2218 * @sci: nilfs_sc_info
2219 *
2220 * If the timer has already been set, it ignores the new request.
2221 * This function MUST be called within a section locking the segment
2222 * semaphore.
2223 */
2224 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2225 {
2226 spin_lock(&sci->sc_state_lock);
2227 if (sci->sc_timer && !(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2228 sci->sc_timer->expires = jiffies + sci->sc_interval;
2229 add_timer(sci->sc_timer);
2230 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2231 }
2232 spin_unlock(&sci->sc_state_lock);
2233 }
2234
2235 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2236 {
2237 spin_lock(&sci->sc_state_lock);
2238 if (!(sci->sc_flush_request & (1 << bn))) {
2239 unsigned long prev_req = sci->sc_flush_request;
2240
2241 sci->sc_flush_request |= (1 << bn);
2242 if (!prev_req)
2243 wake_up(&sci->sc_wait_daemon);
2244 }
2245 spin_unlock(&sci->sc_state_lock);
2246 }
2247
2248 /**
2249 * nilfs_flush_segment - trigger a segment construction for resource control
2250 * @sb: super block
2251 * @ino: inode number of the file to be flushed out.
2252 */
2253 void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2254 {
2255 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2256 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2257
2258 if (!sci || nilfs_doing_construction())
2259 return;
2260 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2261 /* assign bit 0 to data files */
2262 }
2263
2264 struct nilfs_segctor_wait_request {
2265 wait_queue_t wq;
2266 __u32 seq;
2267 int err;
2268 atomic_t done;
2269 };
2270
2271 static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2272 {
2273 struct nilfs_segctor_wait_request wait_req;
2274 int err = 0;
2275
2276 spin_lock(&sci->sc_state_lock);
2277 init_wait(&wait_req.wq);
2278 wait_req.err = 0;
2279 atomic_set(&wait_req.done, 0);
2280 wait_req.seq = ++sci->sc_seq_request;
2281 spin_unlock(&sci->sc_state_lock);
2282
2283 init_waitqueue_entry(&wait_req.wq, current);
2284 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2285 set_current_state(TASK_INTERRUPTIBLE);
2286 wake_up(&sci->sc_wait_daemon);
2287
2288 for (;;) {
2289 if (atomic_read(&wait_req.done)) {
2290 err = wait_req.err;
2291 break;
2292 }
2293 if (!signal_pending(current)) {
2294 schedule();
2295 continue;
2296 }
2297 err = -ERESTARTSYS;
2298 break;
2299 }
2300 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2301 return err;
2302 }
2303
2304 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2305 {
2306 struct nilfs_segctor_wait_request *wrq, *n;
2307 unsigned long flags;
2308
2309 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2310 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2311 wq.task_list) {
2312 if (!atomic_read(&wrq->done) &&
2313 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2314 wrq->err = err;
2315 atomic_set(&wrq->done, 1);
2316 }
2317 if (atomic_read(&wrq->done)) {
2318 wrq->wq.func(&wrq->wq,
2319 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2320 0, NULL);
2321 }
2322 }
2323 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2324 }
2325
2326 /**
2327 * nilfs_construct_segment - construct a logical segment
2328 * @sb: super block
2329 *
2330 * Return Value: On success, 0 is retured. On errors, one of the following
2331 * negative error code is returned.
2332 *
2333 * %-EROFS - Read only filesystem.
2334 *
2335 * %-EIO - I/O error
2336 *
2337 * %-ENOSPC - No space left on device (only in a panic state).
2338 *
2339 * %-ERESTARTSYS - Interrupted.
2340 *
2341 * %-ENOMEM - Insufficient memory available.
2342 */
2343 int nilfs_construct_segment(struct super_block *sb)
2344 {
2345 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2346 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2347 struct nilfs_transaction_info *ti;
2348 int err;
2349
2350 if (!sci)
2351 return -EROFS;
2352
2353 /* A call inside transactions causes a deadlock. */
2354 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2355
2356 err = nilfs_segctor_sync(sci);
2357 return err;
2358 }
2359
2360 /**
2361 * nilfs_construct_dsync_segment - construct a data-only logical segment
2362 * @sb: super block
2363 * @inode: inode whose data blocks should be written out
2364 * @start: start byte offset
2365 * @end: end byte offset (inclusive)
2366 *
2367 * Return Value: On success, 0 is retured. On errors, one of the following
2368 * negative error code is returned.
2369 *
2370 * %-EROFS - Read only filesystem.
2371 *
2372 * %-EIO - I/O error
2373 *
2374 * %-ENOSPC - No space left on device (only in a panic state).
2375 *
2376 * %-ERESTARTSYS - Interrupted.
2377 *
2378 * %-ENOMEM - Insufficient memory available.
2379 */
2380 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2381 loff_t start, loff_t end)
2382 {
2383 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2384 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2385 struct nilfs_inode_info *ii;
2386 struct nilfs_transaction_info ti;
2387 int err = 0;
2388
2389 if (!sci)
2390 return -EROFS;
2391
2392 nilfs_transaction_lock(sbi, &ti, 0);
2393
2394 ii = NILFS_I(inode);
2395 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
2396 nilfs_test_opt(sbi, STRICT_ORDER) ||
2397 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2398 nilfs_discontinued(sbi->s_nilfs)) {
2399 nilfs_transaction_unlock(sbi);
2400 err = nilfs_segctor_sync(sci);
2401 return err;
2402 }
2403
2404 spin_lock(&sbi->s_inode_lock);
2405 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2406 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2407 spin_unlock(&sbi->s_inode_lock);
2408 nilfs_transaction_unlock(sbi);
2409 return 0;
2410 }
2411 spin_unlock(&sbi->s_inode_lock);
2412 sci->sc_dsync_inode = ii;
2413 sci->sc_dsync_start = start;
2414 sci->sc_dsync_end = end;
2415
2416 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2417
2418 nilfs_transaction_unlock(sbi);
2419 return err;
2420 }
2421
2422 #define FLUSH_FILE_BIT (0x1) /* data file only */
2423 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2424
2425 /**
2426 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2427 * @sci: segment constructor object
2428 */
2429 static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2430 {
2431 spin_lock(&sci->sc_state_lock);
2432 sci->sc_seq_accepted = sci->sc_seq_request;
2433 spin_unlock(&sci->sc_state_lock);
2434
2435 if (sci->sc_timer)
2436 del_timer_sync(sci->sc_timer);
2437 }
2438
2439 /**
2440 * nilfs_segctor_notify - notify the result of request to caller threads
2441 * @sci: segment constructor object
2442 * @mode: mode of log forming
2443 * @err: error code to be notified
2444 */
2445 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2446 {
2447 /* Clear requests (even when the construction failed) */
2448 spin_lock(&sci->sc_state_lock);
2449
2450 if (mode == SC_LSEG_SR) {
2451 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2452 sci->sc_seq_done = sci->sc_seq_accepted;
2453 nilfs_segctor_wakeup(sci, err);
2454 sci->sc_flush_request = 0;
2455 } else {
2456 if (mode == SC_FLUSH_FILE)
2457 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2458 else if (mode == SC_FLUSH_DAT)
2459 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2460
2461 /* re-enable timer if checkpoint creation was not done */
2462 if (sci->sc_timer && (sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2463 time_before(jiffies, sci->sc_timer->expires))
2464 add_timer(sci->sc_timer);
2465 }
2466 spin_unlock(&sci->sc_state_lock);
2467 }
2468
2469 /**
2470 * nilfs_segctor_construct - form logs and write them to disk
2471 * @sci: segment constructor object
2472 * @mode: mode of log forming
2473 */
2474 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2475 {
2476 struct nilfs_sb_info *sbi = sci->sc_sbi;
2477 struct the_nilfs *nilfs = sbi->s_nilfs;
2478 int err = 0;
2479
2480 nilfs_segctor_accept(sci);
2481
2482 if (nilfs_discontinued(nilfs))
2483 mode = SC_LSEG_SR;
2484 if (!nilfs_segctor_confirm(sci))
2485 err = nilfs_segctor_do_construct(sci, mode);
2486
2487 if (likely(!err)) {
2488 if (mode != SC_FLUSH_DAT)
2489 atomic_set(&nilfs->ns_ndirtyblks, 0);
2490 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2491 nilfs_discontinued(nilfs)) {
2492 down_write(&nilfs->ns_sem);
2493 err = nilfs_commit_super(
2494 sbi, nilfs_altsb_need_update(nilfs));
2495 up_write(&nilfs->ns_sem);
2496 }
2497 }
2498
2499 nilfs_segctor_notify(sci, mode, err);
2500 return err;
2501 }
2502
2503 static void nilfs_construction_timeout(unsigned long data)
2504 {
2505 struct task_struct *p = (struct task_struct *)data;
2506 wake_up_process(p);
2507 }
2508
2509 static void
2510 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2511 {
2512 struct nilfs_inode_info *ii, *n;
2513
2514 list_for_each_entry_safe(ii, n, head, i_dirty) {
2515 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2516 continue;
2517 hlist_del_init(&ii->vfs_inode.i_hash);
2518 list_del_init(&ii->i_dirty);
2519 nilfs_clear_gcinode(&ii->vfs_inode);
2520 }
2521 }
2522
2523 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2524 void **kbufs)
2525 {
2526 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2527 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2528 struct the_nilfs *nilfs = sbi->s_nilfs;
2529 struct nilfs_transaction_info ti;
2530 int err;
2531
2532 if (unlikely(!sci))
2533 return -EROFS;
2534
2535 nilfs_transaction_lock(sbi, &ti, 1);
2536
2537 err = nilfs_init_gcdat_inode(nilfs);
2538 if (unlikely(err))
2539 goto out_unlock;
2540
2541 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2542 if (unlikely(err))
2543 goto out_unlock;
2544
2545 sci->sc_freesegs = kbufs[4];
2546 sci->sc_nfreesegs = argv[4].v_nmembs;
2547 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2548
2549 for (;;) {
2550 err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2551 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2552
2553 if (likely(!err))
2554 break;
2555
2556 nilfs_warning(sb, __func__,
2557 "segment construction failed. (err=%d)", err);
2558 set_current_state(TASK_INTERRUPTIBLE);
2559 schedule_timeout(sci->sc_interval);
2560 }
2561 if (nilfs_test_opt(sbi, DISCARD)) {
2562 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2563 sci->sc_nfreesegs);
2564 if (ret) {
2565 printk(KERN_WARNING
2566 "NILFS warning: error %d on discard request, "
2567 "turning discards off for the device\n", ret);
2568 nilfs_clear_opt(sbi, DISCARD);
2569 }
2570 }
2571
2572 out_unlock:
2573 sci->sc_freesegs = NULL;
2574 sci->sc_nfreesegs = 0;
2575 nilfs_clear_gcdat_inode(nilfs);
2576 nilfs_transaction_unlock(sbi);
2577 return err;
2578 }
2579
2580 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2581 {
2582 struct nilfs_sb_info *sbi = sci->sc_sbi;
2583 struct nilfs_transaction_info ti;
2584
2585 nilfs_transaction_lock(sbi, &ti, 0);
2586 nilfs_segctor_construct(sci, mode);
2587
2588 /*
2589 * Unclosed segment should be retried. We do this using sc_timer.
2590 * Timeout of sc_timer will invoke complete construction which leads
2591 * to close the current logical segment.
2592 */
2593 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2594 nilfs_segctor_start_timer(sci);
2595
2596 nilfs_transaction_unlock(sbi);
2597 }
2598
2599 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2600 {
2601 int mode = 0;
2602 int err;
2603
2604 spin_lock(&sci->sc_state_lock);
2605 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2606 SC_FLUSH_DAT : SC_FLUSH_FILE;
2607 spin_unlock(&sci->sc_state_lock);
2608
2609 if (mode) {
2610 err = nilfs_segctor_do_construct(sci, mode);
2611
2612 spin_lock(&sci->sc_state_lock);
2613 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2614 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2615 spin_unlock(&sci->sc_state_lock);
2616 }
2617 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2618 }
2619
2620 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2621 {
2622 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2623 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2624 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2625 return SC_FLUSH_FILE;
2626 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2627 return SC_FLUSH_DAT;
2628 }
2629 return SC_LSEG_SR;
2630 }
2631
2632 /**
2633 * nilfs_segctor_thread - main loop of the segment constructor thread.
2634 * @arg: pointer to a struct nilfs_sc_info.
2635 *
2636 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2637 * to execute segment constructions.
2638 */
2639 static int nilfs_segctor_thread(void *arg)
2640 {
2641 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2642 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
2643 struct timer_list timer;
2644 int timeout = 0;
2645
2646 init_timer(&timer);
2647 timer.data = (unsigned long)current;
2648 timer.function = nilfs_construction_timeout;
2649 sci->sc_timer = &timer;
2650
2651 /* start sync. */
2652 sci->sc_task = current;
2653 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2654 printk(KERN_INFO
2655 "segctord starting. Construction interval = %lu seconds, "
2656 "CP frequency < %lu seconds\n",
2657 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2658
2659 spin_lock(&sci->sc_state_lock);
2660 loop:
2661 for (;;) {
2662 int mode;
2663
2664 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2665 goto end_thread;
2666
2667 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2668 mode = SC_LSEG_SR;
2669 else if (!sci->sc_flush_request)
2670 break;
2671 else
2672 mode = nilfs_segctor_flush_mode(sci);
2673
2674 spin_unlock(&sci->sc_state_lock);
2675 nilfs_segctor_thread_construct(sci, mode);
2676 spin_lock(&sci->sc_state_lock);
2677 timeout = 0;
2678 }
2679
2680
2681 if (freezing(current)) {
2682 spin_unlock(&sci->sc_state_lock);
2683 refrigerator();
2684 spin_lock(&sci->sc_state_lock);
2685 } else {
2686 DEFINE_WAIT(wait);
2687 int should_sleep = 1;
2688
2689 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2690 TASK_INTERRUPTIBLE);
2691
2692 if (sci->sc_seq_request != sci->sc_seq_done)
2693 should_sleep = 0;
2694 else if (sci->sc_flush_request)
2695 should_sleep = 0;
2696 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2697 should_sleep = time_before(jiffies,
2698 sci->sc_timer->expires);
2699
2700 if (should_sleep) {
2701 spin_unlock(&sci->sc_state_lock);
2702 schedule();
2703 spin_lock(&sci->sc_state_lock);
2704 }
2705 finish_wait(&sci->sc_wait_daemon, &wait);
2706 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2707 time_after_eq(jiffies, sci->sc_timer->expires));
2708
2709 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2710 set_nilfs_discontinued(nilfs);
2711 }
2712 goto loop;
2713
2714 end_thread:
2715 spin_unlock(&sci->sc_state_lock);
2716 del_timer_sync(sci->sc_timer);
2717 sci->sc_timer = NULL;
2718
2719 /* end sync. */
2720 sci->sc_task = NULL;
2721 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2722 return 0;
2723 }
2724
2725 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2726 {
2727 struct task_struct *t;
2728
2729 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2730 if (IS_ERR(t)) {
2731 int err = PTR_ERR(t);
2732
2733 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2734 err);
2735 return err;
2736 }
2737 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2738 return 0;
2739 }
2740
2741 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2742 {
2743 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2744
2745 while (sci->sc_task) {
2746 wake_up(&sci->sc_wait_daemon);
2747 spin_unlock(&sci->sc_state_lock);
2748 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2749 spin_lock(&sci->sc_state_lock);
2750 }
2751 }
2752
2753 static int nilfs_segctor_init(struct nilfs_sc_info *sci)
2754 {
2755 sci->sc_seq_done = sci->sc_seq_request;
2756
2757 return nilfs_segctor_start_thread(sci);
2758 }
2759
2760 /*
2761 * Setup & clean-up functions
2762 */
2763 static struct nilfs_sc_info *nilfs_segctor_new(struct nilfs_sb_info *sbi)
2764 {
2765 struct nilfs_sc_info *sci;
2766
2767 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2768 if (!sci)
2769 return NULL;
2770
2771 sci->sc_sbi = sbi;
2772 sci->sc_super = sbi->s_super;
2773
2774 init_waitqueue_head(&sci->sc_wait_request);
2775 init_waitqueue_head(&sci->sc_wait_daemon);
2776 init_waitqueue_head(&sci->sc_wait_task);
2777 spin_lock_init(&sci->sc_state_lock);
2778 INIT_LIST_HEAD(&sci->sc_dirty_files);
2779 INIT_LIST_HEAD(&sci->sc_segbufs);
2780 INIT_LIST_HEAD(&sci->sc_write_logs);
2781 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2782 INIT_LIST_HEAD(&sci->sc_copied_buffers);
2783
2784 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2785 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2786 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2787
2788 if (sbi->s_interval)
2789 sci->sc_interval = sbi->s_interval;
2790 if (sbi->s_watermark)
2791 sci->sc_watermark = sbi->s_watermark;
2792 return sci;
2793 }
2794
2795 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2796 {
2797 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2798
2799 /* The segctord thread was stopped and its timer was removed.
2800 But some tasks remain. */
2801 do {
2802 struct nilfs_sb_info *sbi = sci->sc_sbi;
2803 struct nilfs_transaction_info ti;
2804
2805 nilfs_transaction_lock(sbi, &ti, 0);
2806 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2807 nilfs_transaction_unlock(sbi);
2808
2809 } while (ret && retrycount-- > 0);
2810 }
2811
2812 /**
2813 * nilfs_segctor_destroy - destroy the segment constructor.
2814 * @sci: nilfs_sc_info
2815 *
2816 * nilfs_segctor_destroy() kills the segctord thread and frees
2817 * the nilfs_sc_info struct.
2818 * Caller must hold the segment semaphore.
2819 */
2820 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2821 {
2822 struct nilfs_sb_info *sbi = sci->sc_sbi;
2823 int flag;
2824
2825 up_write(&sbi->s_nilfs->ns_segctor_sem);
2826
2827 spin_lock(&sci->sc_state_lock);
2828 nilfs_segctor_kill_thread(sci);
2829 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2830 || sci->sc_seq_request != sci->sc_seq_done);
2831 spin_unlock(&sci->sc_state_lock);
2832
2833 if (flag || !nilfs_segctor_confirm(sci))
2834 nilfs_segctor_write_out(sci);
2835
2836 WARN_ON(!list_empty(&sci->sc_copied_buffers));
2837
2838 if (!list_empty(&sci->sc_dirty_files)) {
2839 nilfs_warning(sbi->s_super, __func__,
2840 "dirty file(s) after the final construction\n");
2841 nilfs_dispose_list(sbi, &sci->sc_dirty_files, 1);
2842 }
2843
2844 WARN_ON(!list_empty(&sci->sc_segbufs));
2845 WARN_ON(!list_empty(&sci->sc_write_logs));
2846
2847 down_write(&sbi->s_nilfs->ns_segctor_sem);
2848
2849 kfree(sci);
2850 }
2851
2852 /**
2853 * nilfs_attach_segment_constructor - attach a segment constructor
2854 * @sbi: nilfs_sb_info
2855 *
2856 * nilfs_attach_segment_constructor() allocates a struct nilfs_sc_info,
2857 * initilizes it, and starts the segment constructor.
2858 *
2859 * Return Value: On success, 0 is returned. On error, one of the following
2860 * negative error code is returned.
2861 *
2862 * %-ENOMEM - Insufficient memory available.
2863 */
2864 int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi)
2865 {
2866 struct the_nilfs *nilfs = sbi->s_nilfs;
2867 int err;
2868
2869 if (NILFS_SC(sbi)) {
2870 /*
2871 * This happens if the filesystem was remounted
2872 * read/write after nilfs_error degenerated it into a
2873 * read-only mount.
2874 */
2875 nilfs_detach_segment_constructor(sbi);
2876 }
2877
2878 sbi->s_sc_info = nilfs_segctor_new(sbi);
2879 if (!sbi->s_sc_info)
2880 return -ENOMEM;
2881
2882 nilfs_attach_writer(nilfs, sbi);
2883 err = nilfs_segctor_init(NILFS_SC(sbi));
2884 if (err) {
2885 nilfs_detach_writer(nilfs, sbi);
2886 kfree(sbi->s_sc_info);
2887 sbi->s_sc_info = NULL;
2888 }
2889 return err;
2890 }
2891
2892 /**
2893 * nilfs_detach_segment_constructor - destroy the segment constructor
2894 * @sbi: nilfs_sb_info
2895 *
2896 * nilfs_detach_segment_constructor() kills the segment constructor daemon,
2897 * frees the struct nilfs_sc_info, and destroy the dirty file list.
2898 */
2899 void nilfs_detach_segment_constructor(struct nilfs_sb_info *sbi)
2900 {
2901 struct the_nilfs *nilfs = sbi->s_nilfs;
2902 LIST_HEAD(garbage_list);
2903
2904 down_write(&nilfs->ns_segctor_sem);
2905 if (NILFS_SC(sbi)) {
2906 nilfs_segctor_destroy(NILFS_SC(sbi));
2907 sbi->s_sc_info = NULL;
2908 }
2909
2910 /* Force to free the list of dirty files */
2911 spin_lock(&sbi->s_inode_lock);
2912 if (!list_empty(&sbi->s_dirty_files)) {
2913 list_splice_init(&sbi->s_dirty_files, &garbage_list);
2914 nilfs_warning(sbi->s_super, __func__,
2915 "Non empty dirty list after the last "
2916 "segment construction\n");
2917 }
2918 spin_unlock(&sbi->s_inode_lock);
2919 up_write(&nilfs->ns_segctor_sem);
2920
2921 nilfs_dispose_list(sbi, &garbage_list, 1);
2922 nilfs_detach_writer(nilfs, sbi);
2923 }
kernel source for telekom puls (alcatel/mediatek)