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Linux 2.6.35-rc2
[linux/fpc-iii.git] / fs / nilfs2 / segment.c
blobc9201649cc49f65e92a42cb3cd1fbe6c81e9184d
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 <linux/slab.h>
36 #include "nilfs.h"
37 #include "btnode.h"
38 #include "page.h"
39 #include "segment.h"
40 #include "sufile.h"
41 #include "cpfile.h"
42 #include "ifile.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_SUFREED 0x0004 /* segment usages has been freed */
83 #define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED)
84
85 /* Operations depending on the construction mode and file type */
86 struct nilfs_sc_operations {
87 int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *,
88 struct inode *);
89 int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *,
90 struct inode *);
91 int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *,
92 struct inode *);
93 void (*write_data_binfo)(struct nilfs_sc_info *,
94 struct nilfs_segsum_pointer *,
95 union nilfs_binfo *);
96 void (*write_node_binfo)(struct nilfs_sc_info *,
97 struct nilfs_segsum_pointer *,
98 union nilfs_binfo *);
99 };
100
101 /*
102 * Other definitions
103 */
104 static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
105 static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
106 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
107 static void nilfs_dispose_list(struct nilfs_sb_info *, struct list_head *,
108 int);
109
110 #define nilfs_cnt32_gt(a, b) \
111 (typecheck(__u32, a) && typecheck(__u32, b) && \
112 ((__s32)(b) - (__s32)(a) < 0))
113 #define nilfs_cnt32_ge(a, b) \
114 (typecheck(__u32, a) && typecheck(__u32, b) && \
115 ((__s32)(a) - (__s32)(b) >= 0))
116 #define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a)
117 #define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a)
118
119 static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
120 {
121 struct nilfs_transaction_info *cur_ti = current->journal_info;
122 void *save = NULL;
123
124 if (cur_ti) {
125 if (cur_ti->ti_magic == NILFS_TI_MAGIC)
126 return ++cur_ti->ti_count;
127 else {
128 /*
129 * If journal_info field is occupied by other FS,
130 * it is saved and will be restored on
131 * nilfs_transaction_commit().
132 */
133 printk(KERN_WARNING
134 "NILFS warning: journal info from a different "
135 "FS\n");
136 save = current->journal_info;
137 }
138 }
139 if (!ti) {
140 ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
141 if (!ti)
142 return -ENOMEM;
143 ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
144 } else {
145 ti->ti_flags = 0;
146 }
147 ti->ti_count = 0;
148 ti->ti_save = save;
149 ti->ti_magic = NILFS_TI_MAGIC;
150 current->journal_info = ti;
151 return 0;
152 }
153
154 /**
155 * nilfs_transaction_begin - start indivisible file operations.
156 * @sb: super block
157 * @ti: nilfs_transaction_info
158 * @vacancy_check: flags for vacancy rate checks
159 *
160 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
161 * the segment semaphore, to make a segment construction and write tasks
162 * exclusive. The function is used with nilfs_transaction_commit() in pairs.
163 * The region enclosed by these two functions can be nested. To avoid a
164 * deadlock, the semaphore is only acquired or released in the outermost call.
165 *
166 * This function allocates a nilfs_transaction_info struct to keep context
167 * information on it. It is initialized and hooked onto the current task in
168 * the outermost call. If a pre-allocated struct is given to @ti, it is used
169 * instead; otherwise a new struct is assigned from a slab.
170 *
171 * When @vacancy_check flag is set, this function will check the amount of
172 * free space, and will wait for the GC to reclaim disk space if low capacity.
173 *
174 * Return Value: On success, 0 is returned. On error, one of the following
175 * negative error code is returned.
176 *
177 * %-ENOMEM - Insufficient memory available.
178 *
179 * %-ENOSPC - No space left on device
180 */
181 int nilfs_transaction_begin(struct super_block *sb,
182 struct nilfs_transaction_info *ti,
183 int vacancy_check)
184 {
185 struct nilfs_sb_info *sbi;
186 struct the_nilfs *nilfs;
187 int ret = nilfs_prepare_segment_lock(ti);
188
189 if (unlikely(ret < 0))
190 return ret;
191 if (ret > 0)
192 return 0;
193
194 sbi = NILFS_SB(sb);
195 nilfs = sbi->s_nilfs;
196 down_read(&nilfs->ns_segctor_sem);
197 if (vacancy_check && nilfs_near_disk_full(nilfs)) {
198 up_read(&nilfs->ns_segctor_sem);
199 ret = -ENOSPC;
200 goto failed;
201 }
202 return 0;
203
204 failed:
205 ti = current->journal_info;
206 current->journal_info = ti->ti_save;
207 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
208 kmem_cache_free(nilfs_transaction_cachep, ti);
209 return ret;
210 }
211
212 /**
213 * nilfs_transaction_commit - commit indivisible file operations.
214 * @sb: super block
215 *
216 * nilfs_transaction_commit() releases the read semaphore which is
217 * acquired by nilfs_transaction_begin(). This is only performed
218 * in outermost call of this function. If a commit flag is set,
219 * nilfs_transaction_commit() sets a timer to start the segment
220 * constructor. If a sync flag is set, it starts construction
221 * directly.
222 */
223 int nilfs_transaction_commit(struct super_block *sb)
224 {
225 struct nilfs_transaction_info *ti = current->journal_info;
226 struct nilfs_sb_info *sbi;
227 struct nilfs_sc_info *sci;
228 int err = 0;
229
230 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
231 ti->ti_flags |= NILFS_TI_COMMIT;
232 if (ti->ti_count > 0) {
233 ti->ti_count--;
234 return 0;
235 }
236 sbi = NILFS_SB(sb);
237 sci = NILFS_SC(sbi);
238 if (sci != NULL) {
239 if (ti->ti_flags & NILFS_TI_COMMIT)
240 nilfs_segctor_start_timer(sci);
241 if (atomic_read(&sbi->s_nilfs->ns_ndirtyblks) >
242 sci->sc_watermark)
243 nilfs_segctor_do_flush(sci, 0);
244 }
245 up_read(&sbi->s_nilfs->ns_segctor_sem);
246 current->journal_info = ti->ti_save;
247
248 if (ti->ti_flags & NILFS_TI_SYNC)
249 err = nilfs_construct_segment(sb);
250 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
251 kmem_cache_free(nilfs_transaction_cachep, ti);
252 return err;
253 }
254
255 void nilfs_transaction_abort(struct super_block *sb)
256 {
257 struct nilfs_transaction_info *ti = current->journal_info;
258
259 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
260 if (ti->ti_count > 0) {
261 ti->ti_count--;
262 return;
263 }
264 up_read(&NILFS_SB(sb)->s_nilfs->ns_segctor_sem);
265
266 current->journal_info = ti->ti_save;
267 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
268 kmem_cache_free(nilfs_transaction_cachep, ti);
269 }
270
271 void nilfs_relax_pressure_in_lock(struct super_block *sb)
272 {
273 struct nilfs_sb_info *sbi = NILFS_SB(sb);
274 struct nilfs_sc_info *sci = NILFS_SC(sbi);
275 struct the_nilfs *nilfs = sbi->s_nilfs;
276
277 if (!sci || !sci->sc_flush_request)
278 return;
279
280 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
281 up_read(&nilfs->ns_segctor_sem);
282
283 down_write(&nilfs->ns_segctor_sem);
284 if (sci->sc_flush_request &&
285 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
286 struct nilfs_transaction_info *ti = current->journal_info;
287
288 ti->ti_flags |= NILFS_TI_WRITER;
289 nilfs_segctor_do_immediate_flush(sci);
290 ti->ti_flags &= ~NILFS_TI_WRITER;
291 }
292 downgrade_write(&nilfs->ns_segctor_sem);
293 }
294
295 static void nilfs_transaction_lock(struct nilfs_sb_info *sbi,
296 struct nilfs_transaction_info *ti,
297 int gcflag)
298 {
299 struct nilfs_transaction_info *cur_ti = current->journal_info;
300
301 WARN_ON(cur_ti);
302 ti->ti_flags = NILFS_TI_WRITER;
303 ti->ti_count = 0;
304 ti->ti_save = cur_ti;
305 ti->ti_magic = NILFS_TI_MAGIC;
306 INIT_LIST_HEAD(&ti->ti_garbage);
307 current->journal_info = ti;
308
309 for (;;) {
310 down_write(&sbi->s_nilfs->ns_segctor_sem);
311 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &NILFS_SC(sbi)->sc_flags))
312 break;
313
314 nilfs_segctor_do_immediate_flush(NILFS_SC(sbi));
315
316 up_write(&sbi->s_nilfs->ns_segctor_sem);
317 yield();
318 }
319 if (gcflag)
320 ti->ti_flags |= NILFS_TI_GC;
321 }
322
323 static void nilfs_transaction_unlock(struct nilfs_sb_info *sbi)
324 {
325 struct nilfs_transaction_info *ti = current->journal_info;
326
327 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
328 BUG_ON(ti->ti_count > 0);
329
330 up_write(&sbi->s_nilfs->ns_segctor_sem);
331 current->journal_info = ti->ti_save;
332 if (!list_empty(&ti->ti_garbage))
333 nilfs_dispose_list(sbi, &ti->ti_garbage, 0);
334 }
335
336 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
337 struct nilfs_segsum_pointer *ssp,
338 unsigned bytes)
339 {
340 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
341 unsigned blocksize = sci->sc_super->s_blocksize;
342 void *p;
343
344 if (unlikely(ssp->offset + bytes > blocksize)) {
345 ssp->offset = 0;
346 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
347 &segbuf->sb_segsum_buffers));
348 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
349 }
350 p = ssp->bh->b_data + ssp->offset;
351 ssp->offset += bytes;
352 return p;
353 }
354
355 /**
356 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
357 * @sci: nilfs_sc_info
358 */
359 static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
360 {
361 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
362 struct buffer_head *sumbh;
363 unsigned sumbytes;
364 unsigned flags = 0;
365 int err;
366
367 if (nilfs_doing_gc())
368 flags = NILFS_SS_GC;
369 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime,
370 sci->sc_sbi->s_nilfs->ns_cno);
371 if (unlikely(err))
372 return err;
373
374 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
375 sumbytes = segbuf->sb_sum.sumbytes;
376 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
377 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
378 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
379 return 0;
380 }
381
382 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
383 {
384 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
385 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
386 return -E2BIG; /* The current segment is filled up
387 (internal code) */
388 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
389 return nilfs_segctor_reset_segment_buffer(sci);
390 }
391
392 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
393 {
394 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
395 int err;
396
397 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
398 err = nilfs_segctor_feed_segment(sci);
399 if (err)
400 return err;
401 segbuf = sci->sc_curseg;
402 }
403 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root);
404 if (likely(!err))
405 segbuf->sb_sum.flags |= NILFS_SS_SR;
406 return err;
407 }
408
409 /*
410 * Functions for making segment summary and payloads
411 */
412 static int nilfs_segctor_segsum_block_required(
413 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
414 unsigned binfo_size)
415 {
416 unsigned blocksize = sci->sc_super->s_blocksize;
417 /* Size of finfo and binfo is enough small against blocksize */
418
419 return ssp->offset + binfo_size +
420 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
421 blocksize;
422 }
423
424 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
425 struct inode *inode)
426 {
427 sci->sc_curseg->sb_sum.nfinfo++;
428 sci->sc_binfo_ptr = sci->sc_finfo_ptr;
429 nilfs_segctor_map_segsum_entry(
430 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
431
432 if (inode->i_sb && !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
433 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
434 /* skip finfo */
435 }
436
437 static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
438 struct inode *inode)
439 {
440 struct nilfs_finfo *finfo;
441 struct nilfs_inode_info *ii;
442 struct nilfs_segment_buffer *segbuf;
443
444 if (sci->sc_blk_cnt == 0)
445 return;
446
447 ii = NILFS_I(inode);
448 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
449 sizeof(*finfo));
450 finfo->fi_ino = cpu_to_le64(inode->i_ino);
451 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
452 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
453 finfo->fi_cno = cpu_to_le64(ii->i_cno);
454
455 segbuf = sci->sc_curseg;
456 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
457 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
458 sci->sc_finfo_ptr = sci->sc_binfo_ptr;
459 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
460 }
461
462 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
463 struct buffer_head *bh,
464 struct inode *inode,
465 unsigned binfo_size)
466 {
467 struct nilfs_segment_buffer *segbuf;
468 int required, err = 0;
469
470 retry:
471 segbuf = sci->sc_curseg;
472 required = nilfs_segctor_segsum_block_required(
473 sci, &sci->sc_binfo_ptr, binfo_size);
474 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
475 nilfs_segctor_end_finfo(sci, inode);
476 err = nilfs_segctor_feed_segment(sci);
477 if (err)
478 return err;
479 goto retry;
480 }
481 if (unlikely(required)) {
482 err = nilfs_segbuf_extend_segsum(segbuf);
483 if (unlikely(err))
484 goto failed;
485 }
486 if (sci->sc_blk_cnt == 0)
487 nilfs_segctor_begin_finfo(sci, inode);
488
489 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
490 /* Substitution to vblocknr is delayed until update_blocknr() */
491 nilfs_segbuf_add_file_buffer(segbuf, bh);
492 sci->sc_blk_cnt++;
493 failed:
494 return err;
495 }
496
497 static int nilfs_handle_bmap_error(int err, const char *fname,
498 struct inode *inode, struct super_block *sb)
499 {
500 if (err == -EINVAL) {
501 nilfs_error(sb, fname, "broken bmap (inode=%lu)\n",
502 inode->i_ino);
503 err = -EIO;
504 }
505 return err;
506 }
507
508 /*
509 * Callback functions that enumerate, mark, and collect dirty blocks
510 */
511 static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
512 struct buffer_head *bh, struct inode *inode)
513 {
514 int err;
515
516 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
517 if (unlikely(err < 0))
518 return nilfs_handle_bmap_error(err, __func__, inode,
519 sci->sc_super);
520
521 err = nilfs_segctor_add_file_block(sci, bh, inode,
522 sizeof(struct nilfs_binfo_v));
523 if (!err)
524 sci->sc_datablk_cnt++;
525 return err;
526 }
527
528 static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
529 struct buffer_head *bh,
530 struct inode *inode)
531 {
532 int err;
533
534 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
535 if (unlikely(err < 0))
536 return nilfs_handle_bmap_error(err, __func__, inode,
537 sci->sc_super);
538 return 0;
539 }
540
541 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
542 struct buffer_head *bh,
543 struct inode *inode)
544 {
545 WARN_ON(!buffer_dirty(bh));
546 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
547 }
548
549 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
550 struct nilfs_segsum_pointer *ssp,
551 union nilfs_binfo *binfo)
552 {
553 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
554 sci, ssp, sizeof(*binfo_v));
555 *binfo_v = binfo->bi_v;
556 }
557
558 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
559 struct nilfs_segsum_pointer *ssp,
560 union nilfs_binfo *binfo)
561 {
562 __le64 *vblocknr = nilfs_segctor_map_segsum_entry(
563 sci, ssp, sizeof(*vblocknr));
564 *vblocknr = binfo->bi_v.bi_vblocknr;
565 }
566
567 static struct nilfs_sc_operations nilfs_sc_file_ops = {
568 .collect_data = nilfs_collect_file_data,
569 .collect_node = nilfs_collect_file_node,
570 .collect_bmap = nilfs_collect_file_bmap,
571 .write_data_binfo = nilfs_write_file_data_binfo,
572 .write_node_binfo = nilfs_write_file_node_binfo,
573 };
574
575 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
576 struct buffer_head *bh, struct inode *inode)
577 {
578 int err;
579
580 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
581 if (unlikely(err < 0))
582 return nilfs_handle_bmap_error(err, __func__, inode,
583 sci->sc_super);
584
585 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
586 if (!err)
587 sci->sc_datablk_cnt++;
588 return err;
589 }
590
591 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
592 struct buffer_head *bh, struct inode *inode)
593 {
594 WARN_ON(!buffer_dirty(bh));
595 return nilfs_segctor_add_file_block(sci, bh, inode,
596 sizeof(struct nilfs_binfo_dat));
597 }
598
599 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
600 struct nilfs_segsum_pointer *ssp,
601 union nilfs_binfo *binfo)
602 {
603 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
604 sizeof(*blkoff));
605 *blkoff = binfo->bi_dat.bi_blkoff;
606 }
607
608 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
609 struct nilfs_segsum_pointer *ssp,
610 union nilfs_binfo *binfo)
611 {
612 struct nilfs_binfo_dat *binfo_dat =
613 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
614 *binfo_dat = binfo->bi_dat;
615 }
616
617 static struct nilfs_sc_operations nilfs_sc_dat_ops = {
618 .collect_data = nilfs_collect_dat_data,
619 .collect_node = nilfs_collect_file_node,
620 .collect_bmap = nilfs_collect_dat_bmap,
621 .write_data_binfo = nilfs_write_dat_data_binfo,
622 .write_node_binfo = nilfs_write_dat_node_binfo,
623 };
624
625 static struct nilfs_sc_operations nilfs_sc_dsync_ops = {
626 .collect_data = nilfs_collect_file_data,
627 .collect_node = NULL,
628 .collect_bmap = NULL,
629 .write_data_binfo = nilfs_write_file_data_binfo,
630 .write_node_binfo = NULL,
631 };
632
633 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
634 struct list_head *listp,
635 size_t nlimit,
636 loff_t start, loff_t end)
637 {
638 struct address_space *mapping = inode->i_mapping;
639 struct pagevec pvec;
640 pgoff_t index = 0, last = ULONG_MAX;
641 size_t ndirties = 0;
642 int i;
643
644 if (unlikely(start != 0 || end != LLONG_MAX)) {
645 /*
646 * A valid range is given for sync-ing data pages. The
647 * range is rounded to per-page; extra dirty buffers
648 * may be included if blocksize < pagesize.
649 */
650 index = start >> PAGE_SHIFT;
651 last = end >> PAGE_SHIFT;
652 }
653 pagevec_init(&pvec, 0);
654 repeat:
655 if (unlikely(index > last) ||
656 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
657 min_t(pgoff_t, last - index,
658 PAGEVEC_SIZE - 1) + 1))
659 return ndirties;
660
661 for (i = 0; i < pagevec_count(&pvec); i++) {
662 struct buffer_head *bh, *head;
663 struct page *page = pvec.pages[i];
664
665 if (unlikely(page->index > last))
666 break;
667
668 if (mapping->host) {
669 lock_page(page);
670 if (!page_has_buffers(page))
671 create_empty_buffers(page,
672 1 << inode->i_blkbits, 0);
673 unlock_page(page);
674 }
675
676 bh = head = page_buffers(page);
677 do {
678 if (!buffer_dirty(bh))
679 continue;
680 get_bh(bh);
681 list_add_tail(&bh->b_assoc_buffers, listp);
682 ndirties++;
683 if (unlikely(ndirties >= nlimit)) {
684 pagevec_release(&pvec);
685 cond_resched();
686 return ndirties;
687 }
688 } while (bh = bh->b_this_page, bh != head);
689 }
690 pagevec_release(&pvec);
691 cond_resched();
692 goto repeat;
693 }
694
695 static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
696 struct list_head *listp)
697 {
698 struct nilfs_inode_info *ii = NILFS_I(inode);
699 struct address_space *mapping = &ii->i_btnode_cache;
700 struct pagevec pvec;
701 struct buffer_head *bh, *head;
702 unsigned int i;
703 pgoff_t index = 0;
704
705 pagevec_init(&pvec, 0);
706
707 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
708 PAGEVEC_SIZE)) {
709 for (i = 0; i < pagevec_count(&pvec); i++) {
710 bh = head = page_buffers(pvec.pages[i]);
711 do {
712 if (buffer_dirty(bh)) {
713 get_bh(bh);
714 list_add_tail(&bh->b_assoc_buffers,
715 listp);
716 }
717 bh = bh->b_this_page;
718 } while (bh != head);
719 }
720 pagevec_release(&pvec);
721 cond_resched();
722 }
723 }
724
725 static void nilfs_dispose_list(struct nilfs_sb_info *sbi,
726 struct list_head *head, int force)
727 {
728 struct nilfs_inode_info *ii, *n;
729 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
730 unsigned nv = 0;
731
732 while (!list_empty(head)) {
733 spin_lock(&sbi->s_inode_lock);
734 list_for_each_entry_safe(ii, n, head, i_dirty) {
735 list_del_init(&ii->i_dirty);
736 if (force) {
737 if (unlikely(ii->i_bh)) {
738 brelse(ii->i_bh);
739 ii->i_bh = NULL;
740 }
741 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
742 set_bit(NILFS_I_QUEUED, &ii->i_state);
743 list_add_tail(&ii->i_dirty,
744 &sbi->s_dirty_files);
745 continue;
746 }
747 ivec[nv++] = ii;
748 if (nv == SC_N_INODEVEC)
749 break;
750 }
751 spin_unlock(&sbi->s_inode_lock);
752
753 for (pii = ivec; nv > 0; pii++, nv--)
754 iput(&(*pii)->vfs_inode);
755 }
756 }
757
758 static int nilfs_test_metadata_dirty(struct nilfs_sb_info *sbi)
759 {
760 struct the_nilfs *nilfs = sbi->s_nilfs;
761 int ret = 0;
762
763 if (nilfs_mdt_fetch_dirty(sbi->s_ifile))
764 ret++;
765 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
766 ret++;
767 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
768 ret++;
769 if (ret || nilfs_doing_gc())
770 if (nilfs_mdt_fetch_dirty(nilfs_dat_inode(nilfs)))
771 ret++;
772 return ret;
773 }
774
775 static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
776 {
777 return list_empty(&sci->sc_dirty_files) &&
778 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
779 sci->sc_nfreesegs == 0 &&
780 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
781 }
782
783 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
784 {
785 struct nilfs_sb_info *sbi = sci->sc_sbi;
786 int ret = 0;
787
788 if (nilfs_test_metadata_dirty(sbi))
789 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
790
791 spin_lock(&sbi->s_inode_lock);
792 if (list_empty(&sbi->s_dirty_files) && nilfs_segctor_clean(sci))
793 ret++;
794
795 spin_unlock(&sbi->s_inode_lock);
796 return ret;
797 }
798
799 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
800 {
801 struct nilfs_sb_info *sbi = sci->sc_sbi;
802 struct the_nilfs *nilfs = sbi->s_nilfs;
803
804 nilfs_mdt_clear_dirty(sbi->s_ifile);
805 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
806 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
807 nilfs_mdt_clear_dirty(nilfs_dat_inode(nilfs));
808 }
809
810 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
811 {
812 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
813 struct buffer_head *bh_cp;
814 struct nilfs_checkpoint *raw_cp;
815 int err;
816
817 /* XXX: this interface will be changed */
818 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
819 &raw_cp, &bh_cp);
820 if (likely(!err)) {
821 /* The following code is duplicated with cpfile. But, it is
822 needed to collect the checkpoint even if it was not newly
823 created */
824 nilfs_mdt_mark_buffer_dirty(bh_cp);
825 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
826 nilfs_cpfile_put_checkpoint(
827 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
828 } else
829 WARN_ON(err == -EINVAL || err == -ENOENT);
830
831 return err;
832 }
833
834 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
835 {
836 struct nilfs_sb_info *sbi = sci->sc_sbi;
837 struct the_nilfs *nilfs = sbi->s_nilfs;
838 struct buffer_head *bh_cp;
839 struct nilfs_checkpoint *raw_cp;
840 int err;
841
842 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
843 &raw_cp, &bh_cp);
844 if (unlikely(err)) {
845 WARN_ON(err == -EINVAL || err == -ENOENT);
846 goto failed_ibh;
847 }
848 raw_cp->cp_snapshot_list.ssl_next = 0;
849 raw_cp->cp_snapshot_list.ssl_prev = 0;
850 raw_cp->cp_inodes_count =
851 cpu_to_le64(atomic_read(&sbi->s_inodes_count));
852 raw_cp->cp_blocks_count =
853 cpu_to_le64(atomic_read(&sbi->s_blocks_count));
854 raw_cp->cp_nblk_inc =
855 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
856 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
857 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
858
859 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
860 nilfs_checkpoint_clear_minor(raw_cp);
861 else
862 nilfs_checkpoint_set_minor(raw_cp);
863
864 nilfs_write_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode, 1);
865 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
866 return 0;
867
868 failed_ibh:
869 return err;
870 }
871
872 static void nilfs_fill_in_file_bmap(struct inode *ifile,
873 struct nilfs_inode_info *ii)
874
875 {
876 struct buffer_head *ibh;
877 struct nilfs_inode *raw_inode;
878
879 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
880 ibh = ii->i_bh;
881 BUG_ON(!ibh);
882 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
883 ibh);
884 nilfs_bmap_write(ii->i_bmap, raw_inode);
885 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
886 }
887 }
888
889 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci,
890 struct inode *ifile)
891 {
892 struct nilfs_inode_info *ii;
893
894 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
895 nilfs_fill_in_file_bmap(ifile, ii);
896 set_bit(NILFS_I_COLLECTED, &ii->i_state);
897 }
898 }
899
900 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
901 struct the_nilfs *nilfs)
902 {
903 struct buffer_head *bh_sr;
904 struct nilfs_super_root *raw_sr;
905 unsigned isz = nilfs->ns_inode_size;
906
907 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
908 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
909
910 raw_sr->sr_bytes = cpu_to_le16(NILFS_SR_BYTES);
911 raw_sr->sr_nongc_ctime
912 = cpu_to_le64(nilfs_doing_gc() ?
913 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
914 raw_sr->sr_flags = 0;
915
916 nilfs_write_inode_common(nilfs_dat_inode(nilfs), (void *)raw_sr +
917 NILFS_SR_DAT_OFFSET(isz), 1);
918 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
919 NILFS_SR_CPFILE_OFFSET(isz), 1);
920 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
921 NILFS_SR_SUFILE_OFFSET(isz), 1);
922 }
923
924 static void nilfs_redirty_inodes(struct list_head *head)
925 {
926 struct nilfs_inode_info *ii;
927
928 list_for_each_entry(ii, head, i_dirty) {
929 if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
930 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
931 }
932 }
933
934 static void nilfs_drop_collected_inodes(struct list_head *head)
935 {
936 struct nilfs_inode_info *ii;
937
938 list_for_each_entry(ii, head, i_dirty) {
939 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
940 continue;
941
942 clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
943 set_bit(NILFS_I_UPDATED, &ii->i_state);
944 }
945 }
946
947 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
948 struct inode *inode,
949 struct list_head *listp,
950 int (*collect)(struct nilfs_sc_info *,
951 struct buffer_head *,
952 struct inode *))
953 {
954 struct buffer_head *bh, *n;
955 int err = 0;
956
957 if (collect) {
958 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
959 list_del_init(&bh->b_assoc_buffers);
960 err = collect(sci, bh, inode);
961 brelse(bh);
962 if (unlikely(err))
963 goto dispose_buffers;
964 }
965 return 0;
966 }
967
968 dispose_buffers:
969 while (!list_empty(listp)) {
970 bh = list_entry(listp->next, struct buffer_head,
971 b_assoc_buffers);
972 list_del_init(&bh->b_assoc_buffers);
973 brelse(bh);
974 }
975 return err;
976 }
977
978 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
979 {
980 /* Remaining number of blocks within segment buffer */
981 return sci->sc_segbuf_nblocks -
982 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
983 }
984
985 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
986 struct inode *inode,
987 struct nilfs_sc_operations *sc_ops)
988 {
989 LIST_HEAD(data_buffers);
990 LIST_HEAD(node_buffers);
991 int err;
992
993 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
994 size_t n, rest = nilfs_segctor_buffer_rest(sci);
995
996 n = nilfs_lookup_dirty_data_buffers(
997 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
998 if (n > rest) {
999 err = nilfs_segctor_apply_buffers(
1000 sci, inode, &data_buffers,
1001 sc_ops->collect_data);
1002 BUG_ON(!err); /* always receive -E2BIG or true error */
1003 goto break_or_fail;
1004 }
1005 }
1006 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
1007
1008 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1009 err = nilfs_segctor_apply_buffers(
1010 sci, inode, &data_buffers, sc_ops->collect_data);
1011 if (unlikely(err)) {
1012 /* dispose node list */
1013 nilfs_segctor_apply_buffers(
1014 sci, inode, &node_buffers, NULL);
1015 goto break_or_fail;
1016 }
1017 sci->sc_stage.flags |= NILFS_CF_NODE;
1018 }
1019 /* Collect node */
1020 err = nilfs_segctor_apply_buffers(
1021 sci, inode, &node_buffers, sc_ops->collect_node);
1022 if (unlikely(err))
1023 goto break_or_fail;
1024
1025 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1026 err = nilfs_segctor_apply_buffers(
1027 sci, inode, &node_buffers, sc_ops->collect_bmap);
1028 if (unlikely(err))
1029 goto break_or_fail;
1030
1031 nilfs_segctor_end_finfo(sci, inode);
1032 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1033
1034 break_or_fail:
1035 return err;
1036 }
1037
1038 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1039 struct inode *inode)
1040 {
1041 LIST_HEAD(data_buffers);
1042 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1043 int err;
1044
1045 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1046 sci->sc_dsync_start,
1047 sci->sc_dsync_end);
1048
1049 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1050 nilfs_collect_file_data);
1051 if (!err) {
1052 nilfs_segctor_end_finfo(sci, inode);
1053 BUG_ON(n > rest);
1054 /* always receive -E2BIG or true error if n > rest */
1055 }
1056 return err;
1057 }
1058
1059 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1060 {
1061 struct nilfs_sb_info *sbi = sci->sc_sbi;
1062 struct the_nilfs *nilfs = sbi->s_nilfs;
1063 struct list_head *head;
1064 struct nilfs_inode_info *ii;
1065 size_t ndone;
1066 int err = 0;
1067
1068 switch (sci->sc_stage.scnt) {
1069 case NILFS_ST_INIT:
1070 /* Pre-processes */
1071 sci->sc_stage.flags = 0;
1072
1073 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1074 sci->sc_nblk_inc = 0;
1075 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1076 if (mode == SC_LSEG_DSYNC) {
1077 sci->sc_stage.scnt = NILFS_ST_DSYNC;
1078 goto dsync_mode;
1079 }
1080 }
1081
1082 sci->sc_stage.dirty_file_ptr = NULL;
1083 sci->sc_stage.gc_inode_ptr = NULL;
1084 if (mode == SC_FLUSH_DAT) {
1085 sci->sc_stage.scnt = NILFS_ST_DAT;
1086 goto dat_stage;
1087 }
1088 sci->sc_stage.scnt++; /* Fall through */
1089 case NILFS_ST_GC:
1090 if (nilfs_doing_gc()) {
1091 head = &sci->sc_gc_inodes;
1092 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1093 head, i_dirty);
1094 list_for_each_entry_continue(ii, head, i_dirty) {
1095 err = nilfs_segctor_scan_file(
1096 sci, &ii->vfs_inode,
1097 &nilfs_sc_file_ops);
1098 if (unlikely(err)) {
1099 sci->sc_stage.gc_inode_ptr = list_entry(
1100 ii->i_dirty.prev,
1101 struct nilfs_inode_info,
1102 i_dirty);
1103 goto break_or_fail;
1104 }
1105 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1106 }
1107 sci->sc_stage.gc_inode_ptr = NULL;
1108 }
1109 sci->sc_stage.scnt++; /* Fall through */
1110 case NILFS_ST_FILE:
1111 head = &sci->sc_dirty_files;
1112 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1113 i_dirty);
1114 list_for_each_entry_continue(ii, head, i_dirty) {
1115 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1116
1117 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1118 &nilfs_sc_file_ops);
1119 if (unlikely(err)) {
1120 sci->sc_stage.dirty_file_ptr =
1121 list_entry(ii->i_dirty.prev,
1122 struct nilfs_inode_info,
1123 i_dirty);
1124 goto break_or_fail;
1125 }
1126 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1127 /* XXX: required ? */
1128 }
1129 sci->sc_stage.dirty_file_ptr = NULL;
1130 if (mode == SC_FLUSH_FILE) {
1131 sci->sc_stage.scnt = NILFS_ST_DONE;
1132 return 0;
1133 }
1134 sci->sc_stage.scnt++;
1135 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1136 /* Fall through */
1137 case NILFS_ST_IFILE:
1138 err = nilfs_segctor_scan_file(sci, sbi->s_ifile,
1139 &nilfs_sc_file_ops);
1140 if (unlikely(err))
1141 break;
1142 sci->sc_stage.scnt++;
1143 /* Creating a checkpoint */
1144 err = nilfs_segctor_create_checkpoint(sci);
1145 if (unlikely(err))
1146 break;
1147 /* Fall through */
1148 case NILFS_ST_CPFILE:
1149 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1150 &nilfs_sc_file_ops);
1151 if (unlikely(err))
1152 break;
1153 sci->sc_stage.scnt++; /* Fall through */
1154 case NILFS_ST_SUFILE:
1155 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1156 sci->sc_nfreesegs, &ndone);
1157 if (unlikely(err)) {
1158 nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1159 sci->sc_freesegs, ndone,
1160 NULL);
1161 break;
1162 }
1163 sci->sc_stage.flags |= NILFS_CF_SUFREED;
1164
1165 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1166 &nilfs_sc_file_ops);
1167 if (unlikely(err))
1168 break;
1169 sci->sc_stage.scnt++; /* Fall through */
1170 case NILFS_ST_DAT:
1171 dat_stage:
1172 err = nilfs_segctor_scan_file(sci, nilfs_dat_inode(nilfs),
1173 &nilfs_sc_dat_ops);
1174 if (unlikely(err))
1175 break;
1176 if (mode == SC_FLUSH_DAT) {
1177 sci->sc_stage.scnt = NILFS_ST_DONE;
1178 return 0;
1179 }
1180 sci->sc_stage.scnt++; /* Fall through */
1181 case NILFS_ST_SR:
1182 if (mode == SC_LSEG_SR) {
1183 /* Appending a super root */
1184 err = nilfs_segctor_add_super_root(sci);
1185 if (unlikely(err))
1186 break;
1187 }
1188 /* End of a logical segment */
1189 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1190 sci->sc_stage.scnt = NILFS_ST_DONE;
1191 return 0;
1192 case NILFS_ST_DSYNC:
1193 dsync_mode:
1194 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1195 ii = sci->sc_dsync_inode;
1196 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1197 break;
1198
1199 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1200 if (unlikely(err))
1201 break;
1202 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1203 sci->sc_stage.scnt = NILFS_ST_DONE;
1204 return 0;
1205 case NILFS_ST_DONE:
1206 return 0;
1207 default:
1208 BUG();
1209 }
1210
1211 break_or_fail:
1212 return err;
1213 }
1214
1215 /**
1216 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1217 * @sci: nilfs_sc_info
1218 * @nilfs: nilfs object
1219 */
1220 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1221 struct the_nilfs *nilfs)
1222 {
1223 struct nilfs_segment_buffer *segbuf, *prev;
1224 __u64 nextnum;
1225 int err, alloc = 0;
1226
1227 segbuf = nilfs_segbuf_new(sci->sc_super);
1228 if (unlikely(!segbuf))
1229 return -ENOMEM;
1230
1231 if (list_empty(&sci->sc_write_logs)) {
1232 nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1233 nilfs->ns_pseg_offset, nilfs);
1234 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1235 nilfs_shift_to_next_segment(nilfs);
1236 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1237 }
1238
1239 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1240 nextnum = nilfs->ns_nextnum;
1241
1242 if (nilfs->ns_segnum == nilfs->ns_nextnum)
1243 /* Start from the head of a new full segment */
1244 alloc++;
1245 } else {
1246 /* Continue logs */
1247 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1248 nilfs_segbuf_map_cont(segbuf, prev);
1249 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1250 nextnum = prev->sb_nextnum;
1251
1252 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1253 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1254 segbuf->sb_sum.seg_seq++;
1255 alloc++;
1256 }
1257 }
1258
1259 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1260 if (err)
1261 goto failed;
1262
1263 if (alloc) {
1264 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1265 if (err)
1266 goto failed;
1267 }
1268 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1269
1270 BUG_ON(!list_empty(&sci->sc_segbufs));
1271 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1272 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1273 return 0;
1274
1275 failed:
1276 nilfs_segbuf_free(segbuf);
1277 return err;
1278 }
1279
1280 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1281 struct the_nilfs *nilfs, int nadd)
1282 {
1283 struct nilfs_segment_buffer *segbuf, *prev;
1284 struct inode *sufile = nilfs->ns_sufile;
1285 __u64 nextnextnum;
1286 LIST_HEAD(list);
1287 int err, ret, i;
1288
1289 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1290 /*
1291 * Since the segment specified with nextnum might be allocated during
1292 * the previous construction, the buffer including its segusage may
1293 * not be dirty. The following call ensures that the buffer is dirty
1294 * and will pin the buffer on memory until the sufile is written.
1295 */
1296 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1297 if (unlikely(err))
1298 return err;
1299
1300 for (i = 0; i < nadd; i++) {
1301 /* extend segment info */
1302 err = -ENOMEM;
1303 segbuf = nilfs_segbuf_new(sci->sc_super);
1304 if (unlikely(!segbuf))
1305 goto failed;
1306
1307 /* map this buffer to region of segment on-disk */
1308 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1309 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1310
1311 /* allocate the next next full segment */
1312 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1313 if (unlikely(err))
1314 goto failed_segbuf;
1315
1316 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1317 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1318
1319 list_add_tail(&segbuf->sb_list, &list);
1320 prev = segbuf;
1321 }
1322 list_splice_tail(&list, &sci->sc_segbufs);
1323 return 0;
1324
1325 failed_segbuf:
1326 nilfs_segbuf_free(segbuf);
1327 failed:
1328 list_for_each_entry(segbuf, &list, sb_list) {
1329 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1330 WARN_ON(ret); /* never fails */
1331 }
1332 nilfs_destroy_logs(&list);
1333 return err;
1334 }
1335
1336 static void nilfs_free_incomplete_logs(struct list_head *logs,
1337 struct the_nilfs *nilfs)
1338 {
1339 struct nilfs_segment_buffer *segbuf, *prev;
1340 struct inode *sufile = nilfs->ns_sufile;
1341 int ret;
1342
1343 segbuf = NILFS_FIRST_SEGBUF(logs);
1344 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1345 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1346 WARN_ON(ret); /* never fails */
1347 }
1348 if (atomic_read(&segbuf->sb_err)) {
1349 /* Case 1: The first segment failed */
1350 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1351 /* Case 1a: Partial segment appended into an existing
1352 segment */
1353 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1354 segbuf->sb_fseg_end);
1355 else /* Case 1b: New full segment */
1356 set_nilfs_discontinued(nilfs);
1357 }
1358
1359 prev = segbuf;
1360 list_for_each_entry_continue(segbuf, logs, sb_list) {
1361 if (prev->sb_nextnum != segbuf->sb_nextnum) {
1362 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1363 WARN_ON(ret); /* never fails */
1364 }
1365 if (atomic_read(&segbuf->sb_err) &&
1366 segbuf->sb_segnum != nilfs->ns_nextnum)
1367 /* Case 2: extended segment (!= next) failed */
1368 nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1369 prev = segbuf;
1370 }
1371 }
1372
1373 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1374 struct inode *sufile)
1375 {
1376 struct nilfs_segment_buffer *segbuf;
1377 unsigned long live_blocks;
1378 int ret;
1379
1380 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1381 live_blocks = segbuf->sb_sum.nblocks +
1382 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1383 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1384 live_blocks,
1385 sci->sc_seg_ctime);
1386 WARN_ON(ret); /* always succeed because the segusage is dirty */
1387 }
1388 }
1389
1390 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1391 {
1392 struct nilfs_segment_buffer *segbuf;
1393 int ret;
1394
1395 segbuf = NILFS_FIRST_SEGBUF(logs);
1396 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1397 segbuf->sb_pseg_start -
1398 segbuf->sb_fseg_start, 0);
1399 WARN_ON(ret); /* always succeed because the segusage is dirty */
1400
1401 list_for_each_entry_continue(segbuf, logs, sb_list) {
1402 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1403 0, 0);
1404 WARN_ON(ret); /* always succeed */
1405 }
1406 }
1407
1408 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1409 struct nilfs_segment_buffer *last,
1410 struct inode *sufile)
1411 {
1412 struct nilfs_segment_buffer *segbuf = last;
1413 int ret;
1414
1415 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1416 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1417 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1418 WARN_ON(ret);
1419 }
1420 nilfs_truncate_logs(&sci->sc_segbufs, last);
1421 }
1422
1423
1424 static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1425 struct the_nilfs *nilfs, int mode)
1426 {
1427 struct nilfs_cstage prev_stage = sci->sc_stage;
1428 int err, nadd = 1;
1429
1430 /* Collection retry loop */
1431 for (;;) {
1432 sci->sc_nblk_this_inc = 0;
1433 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1434
1435 err = nilfs_segctor_reset_segment_buffer(sci);
1436 if (unlikely(err))
1437 goto failed;
1438
1439 err = nilfs_segctor_collect_blocks(sci, mode);
1440 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1441 if (!err)
1442 break;
1443
1444 if (unlikely(err != -E2BIG))
1445 goto failed;
1446
1447 /* The current segment is filled up */
1448 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
1449 break;
1450
1451 nilfs_clear_logs(&sci->sc_segbufs);
1452
1453 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1454 if (unlikely(err))
1455 return err;
1456
1457 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1458 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1459 sci->sc_freesegs,
1460 sci->sc_nfreesegs,
1461 NULL);
1462 WARN_ON(err); /* do not happen */
1463 }
1464 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1465 sci->sc_stage = prev_stage;
1466 }
1467 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1468 return 0;
1469
1470 failed:
1471 return err;
1472 }
1473
1474 static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1475 struct buffer_head *new_bh)
1476 {
1477 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1478
1479 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1480 /* The caller must release old_bh */
1481 }
1482
1483 static int
1484 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1485 struct nilfs_segment_buffer *segbuf,
1486 int mode)
1487 {
1488 struct inode *inode = NULL;
1489 sector_t blocknr;
1490 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1491 unsigned long nblocks = 0, ndatablk = 0;
1492 struct nilfs_sc_operations *sc_op = NULL;
1493 struct nilfs_segsum_pointer ssp;
1494 struct nilfs_finfo *finfo = NULL;
1495 union nilfs_binfo binfo;
1496 struct buffer_head *bh, *bh_org;
1497 ino_t ino = 0;
1498 int err = 0;
1499
1500 if (!nfinfo)
1501 goto out;
1502
1503 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1504 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1505 ssp.offset = sizeof(struct nilfs_segment_summary);
1506
1507 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1508 if (bh == segbuf->sb_super_root)
1509 break;
1510 if (!finfo) {
1511 finfo = nilfs_segctor_map_segsum_entry(
1512 sci, &ssp, sizeof(*finfo));
1513 ino = le64_to_cpu(finfo->fi_ino);
1514 nblocks = le32_to_cpu(finfo->fi_nblocks);
1515 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1516
1517 if (buffer_nilfs_node(bh))
1518 inode = NILFS_BTNC_I(bh->b_page->mapping);
1519 else
1520 inode = NILFS_AS_I(bh->b_page->mapping);
1521
1522 if (mode == SC_LSEG_DSYNC)
1523 sc_op = &nilfs_sc_dsync_ops;
1524 else if (ino == NILFS_DAT_INO)
1525 sc_op = &nilfs_sc_dat_ops;
1526 else /* file blocks */
1527 sc_op = &nilfs_sc_file_ops;
1528 }
1529 bh_org = bh;
1530 get_bh(bh_org);
1531 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1532 &binfo);
1533 if (bh != bh_org)
1534 nilfs_list_replace_buffer(bh_org, bh);
1535 brelse(bh_org);
1536 if (unlikely(err))
1537 goto failed_bmap;
1538
1539 if (ndatablk > 0)
1540 sc_op->write_data_binfo(sci, &ssp, &binfo);
1541 else
1542 sc_op->write_node_binfo(sci, &ssp, &binfo);
1543
1544 blocknr++;
1545 if (--nblocks == 0) {
1546 finfo = NULL;
1547 if (--nfinfo == 0)
1548 break;
1549 } else if (ndatablk > 0)
1550 ndatablk--;
1551 }
1552 out:
1553 return 0;
1554
1555 failed_bmap:
1556 err = nilfs_handle_bmap_error(err, __func__, inode, sci->sc_super);
1557 return err;
1558 }
1559
1560 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1561 {
1562 struct nilfs_segment_buffer *segbuf;
1563 int err;
1564
1565 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1566 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1567 if (unlikely(err))
1568 return err;
1569 nilfs_segbuf_fill_in_segsum(segbuf);
1570 }
1571 return 0;
1572 }
1573
1574 static int
1575 nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out)
1576 {
1577 struct page *clone_page;
1578 struct buffer_head *bh, *head, *bh2;
1579 void *kaddr;
1580
1581 bh = head = page_buffers(page);
1582
1583 clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0);
1584 if (unlikely(!clone_page))
1585 return -ENOMEM;
1586
1587 bh2 = page_buffers(clone_page);
1588 kaddr = kmap_atomic(page, KM_USER0);
1589 do {
1590 if (list_empty(&bh->b_assoc_buffers))
1591 continue;
1592 get_bh(bh2);
1593 page_cache_get(clone_page); /* for each bh */
1594 memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size);
1595 bh2->b_blocknr = bh->b_blocknr;
1596 list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers);
1597 list_add_tail(&bh->b_assoc_buffers, out);
1598 } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head);
1599 kunmap_atomic(kaddr, KM_USER0);
1600
1601 if (!TestSetPageWriteback(clone_page))
1602 inc_zone_page_state(clone_page, NR_WRITEBACK);
1603 unlock_page(clone_page);
1604
1605 return 0;
1606 }
1607
1608 static int nilfs_test_page_to_be_frozen(struct page *page)
1609 {
1610 struct address_space *mapping = page->mapping;
1611
1612 if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode))
1613 return 0;
1614
1615 if (page_mapped(page)) {
1616 ClearPageChecked(page);
1617 return 1;
1618 }
1619 return PageChecked(page);
1620 }
1621
1622 static int nilfs_begin_page_io(struct page *page, struct list_head *out)
1623 {
1624 if (!page || PageWriteback(page))
1625 /* For split b-tree node pages, this function may be called
1626 twice. We ignore the 2nd or later calls by this check. */
1627 return 0;
1628
1629 lock_page(page);
1630 clear_page_dirty_for_io(page);
1631 set_page_writeback(page);
1632 unlock_page(page);
1633
1634 if (nilfs_test_page_to_be_frozen(page)) {
1635 int err = nilfs_copy_replace_page_buffers(page, out);
1636 if (unlikely(err))
1637 return err;
1638 }
1639 return 0;
1640 }
1641
1642 static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
1643 struct page **failed_page)
1644 {
1645 struct nilfs_segment_buffer *segbuf;
1646 struct page *bd_page = NULL, *fs_page = NULL;
1647 struct list_head *list = &sci->sc_copied_buffers;
1648 int err;
1649
1650 *failed_page = NULL;
1651 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1652 struct buffer_head *bh;
1653
1654 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1655 b_assoc_buffers) {
1656 if (bh->b_page != bd_page) {
1657 if (bd_page) {
1658 lock_page(bd_page);
1659 clear_page_dirty_for_io(bd_page);
1660 set_page_writeback(bd_page);
1661 unlock_page(bd_page);
1662 }
1663 bd_page = bh->b_page;
1664 }
1665 }
1666
1667 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1668 b_assoc_buffers) {
1669 if (bh == segbuf->sb_super_root) {
1670 if (bh->b_page != bd_page) {
1671 lock_page(bd_page);
1672 clear_page_dirty_for_io(bd_page);
1673 set_page_writeback(bd_page);
1674 unlock_page(bd_page);
1675 bd_page = bh->b_page;
1676 }
1677 break;
1678 }
1679 if (bh->b_page != fs_page) {
1680 err = nilfs_begin_page_io(fs_page, list);
1681 if (unlikely(err)) {
1682 *failed_page = fs_page;
1683 goto out;
1684 }
1685 fs_page = bh->b_page;
1686 }
1687 }
1688 }
1689 if (bd_page) {
1690 lock_page(bd_page);
1691 clear_page_dirty_for_io(bd_page);
1692 set_page_writeback(bd_page);
1693 unlock_page(bd_page);
1694 }
1695 err = nilfs_begin_page_io(fs_page, list);
1696 if (unlikely(err))
1697 *failed_page = fs_page;
1698 out:
1699 return err;
1700 }
1701
1702 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1703 struct the_nilfs *nilfs)
1704 {
1705 int ret;
1706
1707 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1708 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1709 return ret;
1710 }
1711
1712 static void __nilfs_end_page_io(struct page *page, int err)
1713 {
1714 if (!err) {
1715 if (!nilfs_page_buffers_clean(page))
1716 __set_page_dirty_nobuffers(page);
1717 ClearPageError(page);
1718 } else {
1719 __set_page_dirty_nobuffers(page);
1720 SetPageError(page);
1721 }
1722
1723 if (buffer_nilfs_allocated(page_buffers(page))) {
1724 if (TestClearPageWriteback(page))
1725 dec_zone_page_state(page, NR_WRITEBACK);
1726 } else
1727 end_page_writeback(page);
1728 }
1729
1730 static void nilfs_end_page_io(struct page *page, int err)
1731 {
1732 if (!page)
1733 return;
1734
1735 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
1736 /*
1737 * For b-tree node pages, this function may be called twice
1738 * or more because they might be split in a segment.
1739 */
1740 if (PageDirty(page)) {
1741 /*
1742 * For pages holding split b-tree node buffers, dirty
1743 * flag on the buffers may be cleared discretely.
1744 * In that case, the page is once redirtied for
1745 * remaining buffers, and it must be cancelled if
1746 * all the buffers get cleaned later.
1747 */
1748 lock_page(page);
1749 if (nilfs_page_buffers_clean(page))
1750 __nilfs_clear_page_dirty(page);
1751 unlock_page(page);
1752 }
1753 return;
1754 }
1755
1756 __nilfs_end_page_io(page, err);
1757 }
1758
1759 static void nilfs_clear_copied_buffers(struct list_head *list, int err)
1760 {
1761 struct buffer_head *bh, *head;
1762 struct page *page;
1763
1764 while (!list_empty(list)) {
1765 bh = list_entry(list->next, struct buffer_head,
1766 b_assoc_buffers);
1767 page = bh->b_page;
1768 page_cache_get(page);
1769 head = bh = page_buffers(page);
1770 do {
1771 if (!list_empty(&bh->b_assoc_buffers)) {
1772 list_del_init(&bh->b_assoc_buffers);
1773 if (!err) {
1774 set_buffer_uptodate(bh);
1775 clear_buffer_dirty(bh);
1776 clear_buffer_nilfs_volatile(bh);
1777 }
1778 brelse(bh); /* for b_assoc_buffers */
1779 }
1780 } while ((bh = bh->b_this_page) != head);
1781
1782 __nilfs_end_page_io(page, err);
1783 page_cache_release(page);
1784 }
1785 }
1786
1787 static void nilfs_abort_logs(struct list_head *logs, struct page *failed_page,
1788 int err)
1789 {
1790 struct nilfs_segment_buffer *segbuf;
1791 struct page *bd_page = NULL, *fs_page = NULL;
1792 struct buffer_head *bh;
1793
1794 if (list_empty(logs))
1795 return;
1796
1797 list_for_each_entry(segbuf, logs, sb_list) {
1798 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1799 b_assoc_buffers) {
1800 if (bh->b_page != bd_page) {
1801 if (bd_page)
1802 end_page_writeback(bd_page);
1803 bd_page = bh->b_page;
1804 }
1805 }
1806
1807 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1808 b_assoc_buffers) {
1809 if (bh == segbuf->sb_super_root) {
1810 if (bh->b_page != bd_page) {
1811 end_page_writeback(bd_page);
1812 bd_page = bh->b_page;
1813 }
1814 break;
1815 }
1816 if (bh->b_page != fs_page) {
1817 nilfs_end_page_io(fs_page, err);
1818 if (fs_page && fs_page == failed_page)
1819 return;
1820 fs_page = bh->b_page;
1821 }
1822 }
1823 }
1824 if (bd_page)
1825 end_page_writeback(bd_page);
1826
1827 nilfs_end_page_io(fs_page, err);
1828 }
1829
1830 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1831 struct the_nilfs *nilfs, int err)
1832 {
1833 LIST_HEAD(logs);
1834 int ret;
1835
1836 list_splice_tail_init(&sci->sc_write_logs, &logs);
1837 ret = nilfs_wait_on_logs(&logs);
1838 nilfs_abort_logs(&logs, NULL, ret ? : err);
1839
1840 list_splice_tail_init(&sci->sc_segbufs, &logs);
1841 nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1842 nilfs_free_incomplete_logs(&logs, nilfs);
1843 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err);
1844
1845 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1846 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1847 sci->sc_freesegs,
1848 sci->sc_nfreesegs,
1849 NULL);
1850 WARN_ON(ret); /* do not happen */
1851 }
1852
1853 nilfs_destroy_logs(&logs);
1854 }
1855
1856 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1857 struct nilfs_segment_buffer *segbuf)
1858 {
1859 nilfs->ns_segnum = segbuf->sb_segnum;
1860 nilfs->ns_nextnum = segbuf->sb_nextnum;
1861 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1862 + segbuf->sb_sum.nblocks;
1863 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1864 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1865 }
1866
1867 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1868 {
1869 struct nilfs_segment_buffer *segbuf;
1870 struct page *bd_page = NULL, *fs_page = NULL;
1871 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
1872 int update_sr = false;
1873
1874 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1875 struct buffer_head *bh;
1876
1877 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1878 b_assoc_buffers) {
1879 set_buffer_uptodate(bh);
1880 clear_buffer_dirty(bh);
1881 if (bh->b_page != bd_page) {
1882 if (bd_page)
1883 end_page_writeback(bd_page);
1884 bd_page = bh->b_page;
1885 }
1886 }
1887 /*
1888 * We assume that the buffers which belong to the same page
1889 * continue over the buffer list.
1890 * Under this assumption, the last BHs of pages is
1891 * identifiable by the discontinuity of bh->b_page
1892 * (page != fs_page).
1893 *
1894 * For B-tree node blocks, however, this assumption is not
1895 * guaranteed. The cleanup code of B-tree node pages needs
1896 * special care.
1897 */
1898 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1899 b_assoc_buffers) {
1900 set_buffer_uptodate(bh);
1901 clear_buffer_dirty(bh);
1902 clear_buffer_nilfs_volatile(bh);
1903 if (bh == segbuf->sb_super_root) {
1904 if (bh->b_page != bd_page) {
1905 end_page_writeback(bd_page);
1906 bd_page = bh->b_page;
1907 }
1908 update_sr = true;
1909 break;
1910 }
1911 if (bh->b_page != fs_page) {
1912 nilfs_end_page_io(fs_page, 0);
1913 fs_page = bh->b_page;
1914 }
1915 }
1916
1917 if (!NILFS_SEG_SIMPLEX(&segbuf->sb_sum)) {
1918 if (NILFS_SEG_LOGBGN(&segbuf->sb_sum)) {
1919 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1920 sci->sc_lseg_stime = jiffies;
1921 }
1922 if (NILFS_SEG_LOGEND(&segbuf->sb_sum))
1923 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1924 }
1925 }
1926 /*
1927 * Since pages may continue over multiple segment buffers,
1928 * end of the last page must be checked outside of the loop.
1929 */
1930 if (bd_page)
1931 end_page_writeback(bd_page);
1932
1933 nilfs_end_page_io(fs_page, 0);
1934
1935 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, 0);
1936
1937 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1938
1939 if (nilfs_doing_gc()) {
1940 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1941 if (update_sr)
1942 nilfs_commit_gcdat_inode(nilfs);
1943 } else
1944 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1945
1946 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1947
1948 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1949 nilfs_set_next_segment(nilfs, segbuf);
1950
1951 if (update_sr) {
1952 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
1953 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
1954 set_nilfs_sb_dirty(nilfs);
1955
1956 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
1957 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1958 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1959 nilfs_segctor_clear_metadata_dirty(sci);
1960 } else
1961 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1962 }
1963
1964 static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
1965 {
1966 int ret;
1967
1968 ret = nilfs_wait_on_logs(&sci->sc_write_logs);
1969 if (!ret) {
1970 nilfs_segctor_complete_write(sci);
1971 nilfs_destroy_logs(&sci->sc_write_logs);
1972 }
1973 return ret;
1974 }
1975
1976 static int nilfs_segctor_check_in_files(struct nilfs_sc_info *sci,
1977 struct nilfs_sb_info *sbi)
1978 {
1979 struct nilfs_inode_info *ii, *n;
1980 __u64 cno = sbi->s_nilfs->ns_cno;
1981
1982 spin_lock(&sbi->s_inode_lock);
1983 retry:
1984 list_for_each_entry_safe(ii, n, &sbi->s_dirty_files, i_dirty) {
1985 if (!ii->i_bh) {
1986 struct buffer_head *ibh;
1987 int err;
1988
1989 spin_unlock(&sbi->s_inode_lock);
1990 err = nilfs_ifile_get_inode_block(
1991 sbi->s_ifile, ii->vfs_inode.i_ino, &ibh);
1992 if (unlikely(err)) {
1993 nilfs_warning(sbi->s_super, __func__,
1994 "failed to get inode block.\n");
1995 return err;
1996 }
1997 nilfs_mdt_mark_buffer_dirty(ibh);
1998 nilfs_mdt_mark_dirty(sbi->s_ifile);
1999 spin_lock(&sbi->s_inode_lock);
2000 if (likely(!ii->i_bh))
2001 ii->i_bh = ibh;
2002 else
2003 brelse(ibh);
2004 goto retry;
2005 }
2006 ii->i_cno = cno;
2007
2008 clear_bit(NILFS_I_QUEUED, &ii->i_state);
2009 set_bit(NILFS_I_BUSY, &ii->i_state);
2010 list_del(&ii->i_dirty);
2011 list_add_tail(&ii->i_dirty, &sci->sc_dirty_files);
2012 }
2013 spin_unlock(&sbi->s_inode_lock);
2014
2015 NILFS_I(sbi->s_ifile)->i_cno = cno;
2016
2017 return 0;
2018 }
2019
2020 static void nilfs_segctor_check_out_files(struct nilfs_sc_info *sci,
2021 struct nilfs_sb_info *sbi)
2022 {
2023 struct nilfs_transaction_info *ti = current->journal_info;
2024 struct nilfs_inode_info *ii, *n;
2025 __u64 cno = sbi->s_nilfs->ns_cno;
2026
2027 spin_lock(&sbi->s_inode_lock);
2028 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
2029 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
2030 test_bit(NILFS_I_DIRTY, &ii->i_state)) {
2031 /* The current checkpoint number (=nilfs->ns_cno) is
2032 changed between check-in and check-out only if the
2033 super root is written out. So, we can update i_cno
2034 for the inodes that remain in the dirty list. */
2035 ii->i_cno = cno;
2036 continue;
2037 }
2038 clear_bit(NILFS_I_BUSY, &ii->i_state);
2039 brelse(ii->i_bh);
2040 ii->i_bh = NULL;
2041 list_del(&ii->i_dirty);
2042 list_add_tail(&ii->i_dirty, &ti->ti_garbage);
2043 }
2044 spin_unlock(&sbi->s_inode_lock);
2045 }
2046
2047 /*
2048 * Main procedure of segment constructor
2049 */
2050 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2051 {
2052 struct nilfs_sb_info *sbi = sci->sc_sbi;
2053 struct the_nilfs *nilfs = sbi->s_nilfs;
2054 struct page *failed_page;
2055 int err;
2056
2057 sci->sc_stage.scnt = NILFS_ST_INIT;
2058
2059 err = nilfs_segctor_check_in_files(sci, sbi);
2060 if (unlikely(err))
2061 goto out;
2062
2063 if (nilfs_test_metadata_dirty(sbi))
2064 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2065
2066 if (nilfs_segctor_clean(sci))
2067 goto out;
2068
2069 do {
2070 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2071
2072 err = nilfs_segctor_begin_construction(sci, nilfs);
2073 if (unlikely(err))
2074 goto out;
2075
2076 /* Update time stamp */
2077 sci->sc_seg_ctime = get_seconds();
2078
2079 err = nilfs_segctor_collect(sci, nilfs, mode);
2080 if (unlikely(err))
2081 goto failed;
2082
2083 /* Avoid empty segment */
2084 if (sci->sc_stage.scnt == NILFS_ST_DONE &&
2085 NILFS_SEG_EMPTY(&sci->sc_curseg->sb_sum)) {
2086 nilfs_segctor_abort_construction(sci, nilfs, 1);
2087 goto out;
2088 }
2089
2090 err = nilfs_segctor_assign(sci, mode);
2091 if (unlikely(err))
2092 goto failed;
2093
2094 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2095 nilfs_segctor_fill_in_file_bmap(sci, sbi->s_ifile);
2096
2097 if (mode == SC_LSEG_SR &&
2098 sci->sc_stage.scnt >= NILFS_ST_CPFILE) {
2099 err = nilfs_segctor_fill_in_checkpoint(sci);
2100 if (unlikely(err))
2101 goto failed_to_write;
2102
2103 nilfs_segctor_fill_in_super_root(sci, nilfs);
2104 }
2105 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2106
2107 /* Write partial segments */
2108 err = nilfs_segctor_prepare_write(sci, &failed_page);
2109 if (err) {
2110 nilfs_abort_logs(&sci->sc_segbufs, failed_page, err);
2111 goto failed_to_write;
2112 }
2113
2114 nilfs_add_checksums_on_logs(&sci->sc_segbufs,
2115 nilfs->ns_crc_seed);
2116
2117 err = nilfs_segctor_write(sci, nilfs);
2118 if (unlikely(err))
2119 goto failed_to_write;
2120
2121 if (sci->sc_stage.scnt == NILFS_ST_DONE ||
2122 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
2123 /*
2124 * At this point, we avoid double buffering
2125 * for blocksize < pagesize because page dirty
2126 * flag is turned off during write and dirty
2127 * buffers are not properly collected for
2128 * pages crossing over segments.
2129 */
2130 err = nilfs_segctor_wait(sci);
2131 if (err)
2132 goto failed_to_write;
2133 }
2134 } while (sci->sc_stage.scnt != NILFS_ST_DONE);
2135
2136 out:
2137 nilfs_segctor_check_out_files(sci, sbi);
2138 return err;
2139
2140 failed_to_write:
2141 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2142 nilfs_redirty_inodes(&sci->sc_dirty_files);
2143
2144 failed:
2145 if (nilfs_doing_gc())
2146 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2147 nilfs_segctor_abort_construction(sci, nilfs, err);
2148 goto out;
2149 }
2150
2151 /**
2152 * nilfs_segctor_start_timer - set timer of background write
2153 * @sci: nilfs_sc_info
2154 *
2155 * If the timer has already been set, it ignores the new request.
2156 * This function MUST be called within a section locking the segment
2157 * semaphore.
2158 */
2159 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2160 {
2161 spin_lock(&sci->sc_state_lock);
2162 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2163 sci->sc_timer.expires = jiffies + sci->sc_interval;
2164 add_timer(&sci->sc_timer);
2165 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2166 }
2167 spin_unlock(&sci->sc_state_lock);
2168 }
2169
2170 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2171 {
2172 spin_lock(&sci->sc_state_lock);
2173 if (!(sci->sc_flush_request & (1 << bn))) {
2174 unsigned long prev_req = sci->sc_flush_request;
2175
2176 sci->sc_flush_request |= (1 << bn);
2177 if (!prev_req)
2178 wake_up(&sci->sc_wait_daemon);
2179 }
2180 spin_unlock(&sci->sc_state_lock);
2181 }
2182
2183 /**
2184 * nilfs_flush_segment - trigger a segment construction for resource control
2185 * @sb: super block
2186 * @ino: inode number of the file to be flushed out.
2187 */
2188 void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2189 {
2190 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2191 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2192
2193 if (!sci || nilfs_doing_construction())
2194 return;
2195 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2196 /* assign bit 0 to data files */
2197 }
2198
2199 struct nilfs_segctor_wait_request {
2200 wait_queue_t wq;
2201 __u32 seq;
2202 int err;
2203 atomic_t done;
2204 };
2205
2206 static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2207 {
2208 struct nilfs_segctor_wait_request wait_req;
2209 int err = 0;
2210
2211 spin_lock(&sci->sc_state_lock);
2212 init_wait(&wait_req.wq);
2213 wait_req.err = 0;
2214 atomic_set(&wait_req.done, 0);
2215 wait_req.seq = ++sci->sc_seq_request;
2216 spin_unlock(&sci->sc_state_lock);
2217
2218 init_waitqueue_entry(&wait_req.wq, current);
2219 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2220 set_current_state(TASK_INTERRUPTIBLE);
2221 wake_up(&sci->sc_wait_daemon);
2222
2223 for (;;) {
2224 if (atomic_read(&wait_req.done)) {
2225 err = wait_req.err;
2226 break;
2227 }
2228 if (!signal_pending(current)) {
2229 schedule();
2230 continue;
2231 }
2232 err = -ERESTARTSYS;
2233 break;
2234 }
2235 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2236 return err;
2237 }
2238
2239 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2240 {
2241 struct nilfs_segctor_wait_request *wrq, *n;
2242 unsigned long flags;
2243
2244 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2245 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2246 wq.task_list) {
2247 if (!atomic_read(&wrq->done) &&
2248 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2249 wrq->err = err;
2250 atomic_set(&wrq->done, 1);
2251 }
2252 if (atomic_read(&wrq->done)) {
2253 wrq->wq.func(&wrq->wq,
2254 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2255 0, NULL);
2256 }
2257 }
2258 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2259 }
2260
2261 /**
2262 * nilfs_construct_segment - construct a logical segment
2263 * @sb: super block
2264 *
2265 * Return Value: On success, 0 is retured. On errors, one of the following
2266 * negative error code is returned.
2267 *
2268 * %-EROFS - Read only filesystem.
2269 *
2270 * %-EIO - I/O error
2271 *
2272 * %-ENOSPC - No space left on device (only in a panic state).
2273 *
2274 * %-ERESTARTSYS - Interrupted.
2275 *
2276 * %-ENOMEM - Insufficient memory available.
2277 */
2278 int nilfs_construct_segment(struct super_block *sb)
2279 {
2280 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2281 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2282 struct nilfs_transaction_info *ti;
2283 int err;
2284
2285 if (!sci)
2286 return -EROFS;
2287
2288 /* A call inside transactions causes a deadlock. */
2289 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2290
2291 err = nilfs_segctor_sync(sci);
2292 return err;
2293 }
2294
2295 /**
2296 * nilfs_construct_dsync_segment - construct a data-only logical segment
2297 * @sb: super block
2298 * @inode: inode whose data blocks should be written out
2299 * @start: start byte offset
2300 * @end: end byte offset (inclusive)
2301 *
2302 * Return Value: On success, 0 is retured. On errors, one of the following
2303 * negative error code is returned.
2304 *
2305 * %-EROFS - Read only filesystem.
2306 *
2307 * %-EIO - I/O error
2308 *
2309 * %-ENOSPC - No space left on device (only in a panic state).
2310 *
2311 * %-ERESTARTSYS - Interrupted.
2312 *
2313 * %-ENOMEM - Insufficient memory available.
2314 */
2315 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2316 loff_t start, loff_t end)
2317 {
2318 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2319 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2320 struct nilfs_inode_info *ii;
2321 struct nilfs_transaction_info ti;
2322 int err = 0;
2323
2324 if (!sci)
2325 return -EROFS;
2326
2327 nilfs_transaction_lock(sbi, &ti, 0);
2328
2329 ii = NILFS_I(inode);
2330 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
2331 nilfs_test_opt(sbi, STRICT_ORDER) ||
2332 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2333 nilfs_discontinued(sbi->s_nilfs)) {
2334 nilfs_transaction_unlock(sbi);
2335 err = nilfs_segctor_sync(sci);
2336 return err;
2337 }
2338
2339 spin_lock(&sbi->s_inode_lock);
2340 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2341 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2342 spin_unlock(&sbi->s_inode_lock);
2343 nilfs_transaction_unlock(sbi);
2344 return 0;
2345 }
2346 spin_unlock(&sbi->s_inode_lock);
2347 sci->sc_dsync_inode = ii;
2348 sci->sc_dsync_start = start;
2349 sci->sc_dsync_end = end;
2350
2351 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2352
2353 nilfs_transaction_unlock(sbi);
2354 return err;
2355 }
2356
2357 #define FLUSH_FILE_BIT (0x1) /* data file only */
2358 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2359
2360 /**
2361 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2362 * @sci: segment constructor object
2363 */
2364 static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2365 {
2366 spin_lock(&sci->sc_state_lock);
2367 sci->sc_seq_accepted = sci->sc_seq_request;
2368 spin_unlock(&sci->sc_state_lock);
2369 del_timer_sync(&sci->sc_timer);
2370 }
2371
2372 /**
2373 * nilfs_segctor_notify - notify the result of request to caller threads
2374 * @sci: segment constructor object
2375 * @mode: mode of log forming
2376 * @err: error code to be notified
2377 */
2378 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2379 {
2380 /* Clear requests (even when the construction failed) */
2381 spin_lock(&sci->sc_state_lock);
2382
2383 if (mode == SC_LSEG_SR) {
2384 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2385 sci->sc_seq_done = sci->sc_seq_accepted;
2386 nilfs_segctor_wakeup(sci, err);
2387 sci->sc_flush_request = 0;
2388 } else {
2389 if (mode == SC_FLUSH_FILE)
2390 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2391 else if (mode == SC_FLUSH_DAT)
2392 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2393
2394 /* re-enable timer if checkpoint creation was not done */
2395 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2396 time_before(jiffies, sci->sc_timer.expires))
2397 add_timer(&sci->sc_timer);
2398 }
2399 spin_unlock(&sci->sc_state_lock);
2400 }
2401
2402 /**
2403 * nilfs_segctor_construct - form logs and write them to disk
2404 * @sci: segment constructor object
2405 * @mode: mode of log forming
2406 */
2407 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2408 {
2409 struct nilfs_sb_info *sbi = sci->sc_sbi;
2410 struct the_nilfs *nilfs = sbi->s_nilfs;
2411 int err = 0;
2412
2413 nilfs_segctor_accept(sci);
2414
2415 if (nilfs_discontinued(nilfs))
2416 mode = SC_LSEG_SR;
2417 if (!nilfs_segctor_confirm(sci))
2418 err = nilfs_segctor_do_construct(sci, mode);
2419
2420 if (likely(!err)) {
2421 if (mode != SC_FLUSH_DAT)
2422 atomic_set(&nilfs->ns_ndirtyblks, 0);
2423 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2424 nilfs_discontinued(nilfs)) {
2425 down_write(&nilfs->ns_sem);
2426 err = nilfs_commit_super(
2427 sbi, nilfs_altsb_need_update(nilfs));
2428 up_write(&nilfs->ns_sem);
2429 }
2430 }
2431
2432 nilfs_segctor_notify(sci, mode, err);
2433 return err;
2434 }
2435
2436 static void nilfs_construction_timeout(unsigned long data)
2437 {
2438 struct task_struct *p = (struct task_struct *)data;
2439 wake_up_process(p);
2440 }
2441
2442 static void
2443 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2444 {
2445 struct nilfs_inode_info *ii, *n;
2446
2447 list_for_each_entry_safe(ii, n, head, i_dirty) {
2448 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2449 continue;
2450 hlist_del_init(&ii->vfs_inode.i_hash);
2451 list_del_init(&ii->i_dirty);
2452 nilfs_clear_gcinode(&ii->vfs_inode);
2453 }
2454 }
2455
2456 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2457 void **kbufs)
2458 {
2459 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2460 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2461 struct the_nilfs *nilfs = sbi->s_nilfs;
2462 struct nilfs_transaction_info ti;
2463 int err;
2464
2465 if (unlikely(!sci))
2466 return -EROFS;
2467
2468 nilfs_transaction_lock(sbi, &ti, 1);
2469
2470 err = nilfs_init_gcdat_inode(nilfs);
2471 if (unlikely(err))
2472 goto out_unlock;
2473
2474 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2475 if (unlikely(err))
2476 goto out_unlock;
2477
2478 sci->sc_freesegs = kbufs[4];
2479 sci->sc_nfreesegs = argv[4].v_nmembs;
2480 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2481
2482 for (;;) {
2483 err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2484 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2485
2486 if (likely(!err))
2487 break;
2488
2489 nilfs_warning(sb, __func__,
2490 "segment construction failed. (err=%d)", err);
2491 set_current_state(TASK_INTERRUPTIBLE);
2492 schedule_timeout(sci->sc_interval);
2493 }
2494 if (nilfs_test_opt(sbi, DISCARD)) {
2495 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2496 sci->sc_nfreesegs);
2497 if (ret) {
2498 printk(KERN_WARNING
2499 "NILFS warning: error %d on discard request, "
2500 "turning discards off for the device\n", ret);
2501 nilfs_clear_opt(sbi, DISCARD);
2502 }
2503 }
2504
2505 out_unlock:
2506 sci->sc_freesegs = NULL;
2507 sci->sc_nfreesegs = 0;
2508 nilfs_clear_gcdat_inode(nilfs);
2509 nilfs_transaction_unlock(sbi);
2510 return err;
2511 }
2512
2513 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2514 {
2515 struct nilfs_sb_info *sbi = sci->sc_sbi;
2516 struct nilfs_transaction_info ti;
2517
2518 nilfs_transaction_lock(sbi, &ti, 0);
2519 nilfs_segctor_construct(sci, mode);
2520
2521 /*
2522 * Unclosed segment should be retried. We do this using sc_timer.
2523 * Timeout of sc_timer will invoke complete construction which leads
2524 * to close the current logical segment.
2525 */
2526 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2527 nilfs_segctor_start_timer(sci);
2528
2529 nilfs_transaction_unlock(sbi);
2530 }
2531
2532 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2533 {
2534 int mode = 0;
2535 int err;
2536
2537 spin_lock(&sci->sc_state_lock);
2538 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2539 SC_FLUSH_DAT : SC_FLUSH_FILE;
2540 spin_unlock(&sci->sc_state_lock);
2541
2542 if (mode) {
2543 err = nilfs_segctor_do_construct(sci, mode);
2544
2545 spin_lock(&sci->sc_state_lock);
2546 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2547 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2548 spin_unlock(&sci->sc_state_lock);
2549 }
2550 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2551 }
2552
2553 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2554 {
2555 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2556 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2557 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2558 return SC_FLUSH_FILE;
2559 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2560 return SC_FLUSH_DAT;
2561 }
2562 return SC_LSEG_SR;
2563 }
2564
2565 /**
2566 * nilfs_segctor_thread - main loop of the segment constructor thread.
2567 * @arg: pointer to a struct nilfs_sc_info.
2568 *
2569 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2570 * to execute segment constructions.
2571 */
2572 static int nilfs_segctor_thread(void *arg)
2573 {
2574 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2575 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
2576 int timeout = 0;
2577
2578 sci->sc_timer.data = (unsigned long)current;
2579 sci->sc_timer.function = nilfs_construction_timeout;
2580
2581 /* start sync. */
2582 sci->sc_task = current;
2583 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2584 printk(KERN_INFO
2585 "segctord starting. Construction interval = %lu seconds, "
2586 "CP frequency < %lu seconds\n",
2587 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2588
2589 spin_lock(&sci->sc_state_lock);
2590 loop:
2591 for (;;) {
2592 int mode;
2593
2594 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2595 goto end_thread;
2596
2597 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2598 mode = SC_LSEG_SR;
2599 else if (!sci->sc_flush_request)
2600 break;
2601 else
2602 mode = nilfs_segctor_flush_mode(sci);
2603
2604 spin_unlock(&sci->sc_state_lock);
2605 nilfs_segctor_thread_construct(sci, mode);
2606 spin_lock(&sci->sc_state_lock);
2607 timeout = 0;
2608 }
2609
2610
2611 if (freezing(current)) {
2612 spin_unlock(&sci->sc_state_lock);
2613 refrigerator();
2614 spin_lock(&sci->sc_state_lock);
2615 } else {
2616 DEFINE_WAIT(wait);
2617 int should_sleep = 1;
2618
2619 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2620 TASK_INTERRUPTIBLE);
2621
2622 if (sci->sc_seq_request != sci->sc_seq_done)
2623 should_sleep = 0;
2624 else if (sci->sc_flush_request)
2625 should_sleep = 0;
2626 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2627 should_sleep = time_before(jiffies,
2628 sci->sc_timer.expires);
2629
2630 if (should_sleep) {
2631 spin_unlock(&sci->sc_state_lock);
2632 schedule();
2633 spin_lock(&sci->sc_state_lock);
2634 }
2635 finish_wait(&sci->sc_wait_daemon, &wait);
2636 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2637 time_after_eq(jiffies, sci->sc_timer.expires));
2638
2639 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2640 set_nilfs_discontinued(nilfs);
2641 }
2642 goto loop;
2643
2644 end_thread:
2645 spin_unlock(&sci->sc_state_lock);
2646
2647 /* end sync. */
2648 sci->sc_task = NULL;
2649 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2650 return 0;
2651 }
2652
2653 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2654 {
2655 struct task_struct *t;
2656
2657 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2658 if (IS_ERR(t)) {
2659 int err = PTR_ERR(t);
2660
2661 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2662 err);
2663 return err;
2664 }
2665 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2666 return 0;
2667 }
2668
2669 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2670 {
2671 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2672
2673 while (sci->sc_task) {
2674 wake_up(&sci->sc_wait_daemon);
2675 spin_unlock(&sci->sc_state_lock);
2676 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2677 spin_lock(&sci->sc_state_lock);
2678 }
2679 }
2680
2681 /*
2682 * Setup & clean-up functions
2683 */
2684 static struct nilfs_sc_info *nilfs_segctor_new(struct nilfs_sb_info *sbi)
2685 {
2686 struct nilfs_sc_info *sci;
2687
2688 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2689 if (!sci)
2690 return NULL;
2691
2692 sci->sc_sbi = sbi;
2693 sci->sc_super = sbi->s_super;
2694
2695 init_waitqueue_head(&sci->sc_wait_request);
2696 init_waitqueue_head(&sci->sc_wait_daemon);
2697 init_waitqueue_head(&sci->sc_wait_task);
2698 spin_lock_init(&sci->sc_state_lock);
2699 INIT_LIST_HEAD(&sci->sc_dirty_files);
2700 INIT_LIST_HEAD(&sci->sc_segbufs);
2701 INIT_LIST_HEAD(&sci->sc_write_logs);
2702 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2703 INIT_LIST_HEAD(&sci->sc_copied_buffers);
2704 init_timer(&sci->sc_timer);
2705
2706 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2707 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2708 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2709
2710 if (sbi->s_interval)
2711 sci->sc_interval = sbi->s_interval;
2712 if (sbi->s_watermark)
2713 sci->sc_watermark = sbi->s_watermark;
2714 return sci;
2715 }
2716
2717 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2718 {
2719 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2720
2721 /* The segctord thread was stopped and its timer was removed.
2722 But some tasks remain. */
2723 do {
2724 struct nilfs_sb_info *sbi = sci->sc_sbi;
2725 struct nilfs_transaction_info ti;
2726
2727 nilfs_transaction_lock(sbi, &ti, 0);
2728 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2729 nilfs_transaction_unlock(sbi);
2730
2731 } while (ret && retrycount-- > 0);
2732 }
2733
2734 /**
2735 * nilfs_segctor_destroy - destroy the segment constructor.
2736 * @sci: nilfs_sc_info
2737 *
2738 * nilfs_segctor_destroy() kills the segctord thread and frees
2739 * the nilfs_sc_info struct.
2740 * Caller must hold the segment semaphore.
2741 */
2742 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2743 {
2744 struct nilfs_sb_info *sbi = sci->sc_sbi;
2745 int flag;
2746
2747 up_write(&sbi->s_nilfs->ns_segctor_sem);
2748
2749 spin_lock(&sci->sc_state_lock);
2750 nilfs_segctor_kill_thread(sci);
2751 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2752 || sci->sc_seq_request != sci->sc_seq_done);
2753 spin_unlock(&sci->sc_state_lock);
2754
2755 if (flag || !nilfs_segctor_confirm(sci))
2756 nilfs_segctor_write_out(sci);
2757
2758 WARN_ON(!list_empty(&sci->sc_copied_buffers));
2759
2760 if (!list_empty(&sci->sc_dirty_files)) {
2761 nilfs_warning(sbi->s_super, __func__,
2762 "dirty file(s) after the final construction\n");
2763 nilfs_dispose_list(sbi, &sci->sc_dirty_files, 1);
2764 }
2765
2766 WARN_ON(!list_empty(&sci->sc_segbufs));
2767 WARN_ON(!list_empty(&sci->sc_write_logs));
2768
2769 down_write(&sbi->s_nilfs->ns_segctor_sem);
2770
2771 del_timer_sync(&sci->sc_timer);
2772 kfree(sci);
2773 }
2774
2775 /**
2776 * nilfs_attach_segment_constructor - attach a segment constructor
2777 * @sbi: nilfs_sb_info
2778 *
2779 * nilfs_attach_segment_constructor() allocates a struct nilfs_sc_info,
2780 * initializes it, and starts the segment constructor.
2781 *
2782 * Return Value: On success, 0 is returned. On error, one of the following
2783 * negative error code is returned.
2784 *
2785 * %-ENOMEM - Insufficient memory available.
2786 */
2787 int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi)
2788 {
2789 struct the_nilfs *nilfs = sbi->s_nilfs;
2790 int err;
2791
2792 if (NILFS_SC(sbi)) {
2793 /*
2794 * This happens if the filesystem was remounted
2795 * read/write after nilfs_error degenerated it into a
2796 * read-only mount.
2797 */
2798 nilfs_detach_segment_constructor(sbi);
2799 }
2800
2801 sbi->s_sc_info = nilfs_segctor_new(sbi);
2802 if (!sbi->s_sc_info)
2803 return -ENOMEM;
2804
2805 nilfs_attach_writer(nilfs, sbi);
2806 err = nilfs_segctor_start_thread(NILFS_SC(sbi));
2807 if (err) {
2808 nilfs_detach_writer(nilfs, sbi);
2809 kfree(sbi->s_sc_info);
2810 sbi->s_sc_info = NULL;
2811 }
2812 return err;
2813 }
2814
2815 /**
2816 * nilfs_detach_segment_constructor - destroy the segment constructor
2817 * @sbi: nilfs_sb_info
2818 *
2819 * nilfs_detach_segment_constructor() kills the segment constructor daemon,
2820 * frees the struct nilfs_sc_info, and destroy the dirty file list.
2821 */
2822 void nilfs_detach_segment_constructor(struct nilfs_sb_info *sbi)
2823 {
2824 struct the_nilfs *nilfs = sbi->s_nilfs;
2825 LIST_HEAD(garbage_list);
2826
2827 down_write(&nilfs->ns_segctor_sem);
2828 if (NILFS_SC(sbi)) {
2829 nilfs_segctor_destroy(NILFS_SC(sbi));
2830 sbi->s_sc_info = NULL;
2831 }
2832
2833 /* Force to free the list of dirty files */
2834 spin_lock(&sbi->s_inode_lock);
2835 if (!list_empty(&sbi->s_dirty_files)) {
2836 list_splice_init(&sbi->s_dirty_files, &garbage_list);
2837 nilfs_warning(sbi->s_super, __func__,
2838 "Non empty dirty list after the last "
2839 "segment construction\n");
2840 }
2841 spin_unlock(&sbi->s_inode_lock);
2842 up_write(&nilfs->ns_segctor_sem);
2843
2844 nilfs_dispose_list(sbi, &garbage_list, 1);
2845 nilfs_detach_writer(nilfs, sbi);
2846 }
Linux with added FPC-III support