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staging: brcm80211: remove of type definition osldma_t
[zen-stable.git] / fs / nilfs2 / segment.c
blob55ebae5c7f39f58d4065850b9fabebb66a93b0cf
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 vfs_check_frozen(sb, SB_FREEZE_WRITE);
195
196 sbi = NILFS_SB(sb);
197 nilfs = sbi->s_nilfs;
198 down_read(&nilfs->ns_segctor_sem);
199 if (vacancy_check && nilfs_near_disk_full(nilfs)) {
200 up_read(&nilfs->ns_segctor_sem);
201 ret = -ENOSPC;
202 goto failed;
203 }
204 return 0;
205
206 failed:
207 ti = current->journal_info;
208 current->journal_info = ti->ti_save;
209 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
210 kmem_cache_free(nilfs_transaction_cachep, ti);
211 return ret;
212 }
213
214 /**
215 * nilfs_transaction_commit - commit indivisible file operations.
216 * @sb: super block
217 *
218 * nilfs_transaction_commit() releases the read semaphore which is
219 * acquired by nilfs_transaction_begin(). This is only performed
220 * in outermost call of this function. If a commit flag is set,
221 * nilfs_transaction_commit() sets a timer to start the segment
222 * constructor. If a sync flag is set, it starts construction
223 * directly.
224 */
225 int nilfs_transaction_commit(struct super_block *sb)
226 {
227 struct nilfs_transaction_info *ti = current->journal_info;
228 struct nilfs_sb_info *sbi;
229 struct nilfs_sc_info *sci;
230 int err = 0;
231
232 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
233 ti->ti_flags |= NILFS_TI_COMMIT;
234 if (ti->ti_count > 0) {
235 ti->ti_count--;
236 return 0;
237 }
238 sbi = NILFS_SB(sb);
239 sci = NILFS_SC(sbi);
240 if (sci != NULL) {
241 if (ti->ti_flags & NILFS_TI_COMMIT)
242 nilfs_segctor_start_timer(sci);
243 if (atomic_read(&sbi->s_nilfs->ns_ndirtyblks) >
244 sci->sc_watermark)
245 nilfs_segctor_do_flush(sci, 0);
246 }
247 up_read(&sbi->s_nilfs->ns_segctor_sem);
248 current->journal_info = ti->ti_save;
249
250 if (ti->ti_flags & NILFS_TI_SYNC)
251 err = nilfs_construct_segment(sb);
252 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
253 kmem_cache_free(nilfs_transaction_cachep, ti);
254 return err;
255 }
256
257 void nilfs_transaction_abort(struct super_block *sb)
258 {
259 struct nilfs_transaction_info *ti = current->journal_info;
260
261 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
262 if (ti->ti_count > 0) {
263 ti->ti_count--;
264 return;
265 }
266 up_read(&NILFS_SB(sb)->s_nilfs->ns_segctor_sem);
267
268 current->journal_info = ti->ti_save;
269 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
270 kmem_cache_free(nilfs_transaction_cachep, ti);
271 }
272
273 void nilfs_relax_pressure_in_lock(struct super_block *sb)
274 {
275 struct nilfs_sb_info *sbi = NILFS_SB(sb);
276 struct nilfs_sc_info *sci = NILFS_SC(sbi);
277 struct the_nilfs *nilfs = sbi->s_nilfs;
278
279 if (!sci || !sci->sc_flush_request)
280 return;
281
282 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
283 up_read(&nilfs->ns_segctor_sem);
284
285 down_write(&nilfs->ns_segctor_sem);
286 if (sci->sc_flush_request &&
287 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
288 struct nilfs_transaction_info *ti = current->journal_info;
289
290 ti->ti_flags |= NILFS_TI_WRITER;
291 nilfs_segctor_do_immediate_flush(sci);
292 ti->ti_flags &= ~NILFS_TI_WRITER;
293 }
294 downgrade_write(&nilfs->ns_segctor_sem);
295 }
296
297 static void nilfs_transaction_lock(struct nilfs_sb_info *sbi,
298 struct nilfs_transaction_info *ti,
299 int gcflag)
300 {
301 struct nilfs_transaction_info *cur_ti = current->journal_info;
302
303 WARN_ON(cur_ti);
304 ti->ti_flags = NILFS_TI_WRITER;
305 ti->ti_count = 0;
306 ti->ti_save = cur_ti;
307 ti->ti_magic = NILFS_TI_MAGIC;
308 INIT_LIST_HEAD(&ti->ti_garbage);
309 current->journal_info = ti;
310
311 for (;;) {
312 down_write(&sbi->s_nilfs->ns_segctor_sem);
313 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &NILFS_SC(sbi)->sc_flags))
314 break;
315
316 nilfs_segctor_do_immediate_flush(NILFS_SC(sbi));
317
318 up_write(&sbi->s_nilfs->ns_segctor_sem);
319 yield();
320 }
321 if (gcflag)
322 ti->ti_flags |= NILFS_TI_GC;
323 }
324
325 static void nilfs_transaction_unlock(struct nilfs_sb_info *sbi)
326 {
327 struct nilfs_transaction_info *ti = current->journal_info;
328
329 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
330 BUG_ON(ti->ti_count > 0);
331
332 up_write(&sbi->s_nilfs->ns_segctor_sem);
333 current->journal_info = ti->ti_save;
334 if (!list_empty(&ti->ti_garbage))
335 nilfs_dispose_list(sbi, &ti->ti_garbage, 0);
336 }
337
338 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
339 struct nilfs_segsum_pointer *ssp,
340 unsigned bytes)
341 {
342 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
343 unsigned blocksize = sci->sc_super->s_blocksize;
344 void *p;
345
346 if (unlikely(ssp->offset + bytes > blocksize)) {
347 ssp->offset = 0;
348 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
349 &segbuf->sb_segsum_buffers));
350 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
351 }
352 p = ssp->bh->b_data + ssp->offset;
353 ssp->offset += bytes;
354 return p;
355 }
356
357 /**
358 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
359 * @sci: nilfs_sc_info
360 */
361 static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
362 {
363 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
364 struct buffer_head *sumbh;
365 unsigned sumbytes;
366 unsigned flags = 0;
367 int err;
368
369 if (nilfs_doing_gc())
370 flags = NILFS_SS_GC;
371 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno);
372 if (unlikely(err))
373 return err;
374
375 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
376 sumbytes = segbuf->sb_sum.sumbytes;
377 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
378 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
379 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
380 return 0;
381 }
382
383 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
384 {
385 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
386 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
387 return -E2BIG; /* The current segment is filled up
388 (internal code) */
389 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
390 return nilfs_segctor_reset_segment_buffer(sci);
391 }
392
393 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
394 {
395 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
396 int err;
397
398 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
399 err = nilfs_segctor_feed_segment(sci);
400 if (err)
401 return err;
402 segbuf = sci->sc_curseg;
403 }
404 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root);
405 if (likely(!err))
406 segbuf->sb_sum.flags |= NILFS_SS_SR;
407 return err;
408 }
409
410 /*
411 * Functions for making segment summary and payloads
412 */
413 static int nilfs_segctor_segsum_block_required(
414 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
415 unsigned binfo_size)
416 {
417 unsigned blocksize = sci->sc_super->s_blocksize;
418 /* Size of finfo and binfo is enough small against blocksize */
419
420 return ssp->offset + binfo_size +
421 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
422 blocksize;
423 }
424
425 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
426 struct inode *inode)
427 {
428 sci->sc_curseg->sb_sum.nfinfo++;
429 sci->sc_binfo_ptr = sci->sc_finfo_ptr;
430 nilfs_segctor_map_segsum_entry(
431 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
432
433 if (inode->i_sb && !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
434 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
435 /* skip finfo */
436 }
437
438 static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
439 struct inode *inode)
440 {
441 struct nilfs_finfo *finfo;
442 struct nilfs_inode_info *ii;
443 struct nilfs_segment_buffer *segbuf;
444 __u64 cno;
445
446 if (sci->sc_blk_cnt == 0)
447 return;
448
449 ii = NILFS_I(inode);
450
451 if (test_bit(NILFS_I_GCINODE, &ii->i_state))
452 cno = ii->i_cno;
453 else if (NILFS_ROOT_METADATA_FILE(inode->i_ino))
454 cno = 0;
455 else
456 cno = sci->sc_cno;
457
458 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
459 sizeof(*finfo));
460 finfo->fi_ino = cpu_to_le64(inode->i_ino);
461 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
462 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
463 finfo->fi_cno = cpu_to_le64(cno);
464
465 segbuf = sci->sc_curseg;
466 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
467 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
468 sci->sc_finfo_ptr = sci->sc_binfo_ptr;
469 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
470 }
471
472 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
473 struct buffer_head *bh,
474 struct inode *inode,
475 unsigned binfo_size)
476 {
477 struct nilfs_segment_buffer *segbuf;
478 int required, err = 0;
479
480 retry:
481 segbuf = sci->sc_curseg;
482 required = nilfs_segctor_segsum_block_required(
483 sci, &sci->sc_binfo_ptr, binfo_size);
484 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
485 nilfs_segctor_end_finfo(sci, inode);
486 err = nilfs_segctor_feed_segment(sci);
487 if (err)
488 return err;
489 goto retry;
490 }
491 if (unlikely(required)) {
492 err = nilfs_segbuf_extend_segsum(segbuf);
493 if (unlikely(err))
494 goto failed;
495 }
496 if (sci->sc_blk_cnt == 0)
497 nilfs_segctor_begin_finfo(sci, inode);
498
499 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
500 /* Substitution to vblocknr is delayed until update_blocknr() */
501 nilfs_segbuf_add_file_buffer(segbuf, bh);
502 sci->sc_blk_cnt++;
503 failed:
504 return err;
505 }
506
507 /*
508 * Callback functions that enumerate, mark, and collect dirty blocks
509 */
510 static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
511 struct buffer_head *bh, struct inode *inode)
512 {
513 int err;
514
515 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
516 if (err < 0)
517 return err;
518
519 err = nilfs_segctor_add_file_block(sci, bh, inode,
520 sizeof(struct nilfs_binfo_v));
521 if (!err)
522 sci->sc_datablk_cnt++;
523 return err;
524 }
525
526 static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
527 struct buffer_head *bh,
528 struct inode *inode)
529 {
530 return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
531 }
532
533 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
534 struct buffer_head *bh,
535 struct inode *inode)
536 {
537 WARN_ON(!buffer_dirty(bh));
538 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
539 }
540
541 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
542 struct nilfs_segsum_pointer *ssp,
543 union nilfs_binfo *binfo)
544 {
545 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
546 sci, ssp, sizeof(*binfo_v));
547 *binfo_v = binfo->bi_v;
548 }
549
550 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
551 struct nilfs_segsum_pointer *ssp,
552 union nilfs_binfo *binfo)
553 {
554 __le64 *vblocknr = nilfs_segctor_map_segsum_entry(
555 sci, ssp, sizeof(*vblocknr));
556 *vblocknr = binfo->bi_v.bi_vblocknr;
557 }
558
559 static struct nilfs_sc_operations nilfs_sc_file_ops = {
560 .collect_data = nilfs_collect_file_data,
561 .collect_node = nilfs_collect_file_node,
562 .collect_bmap = nilfs_collect_file_bmap,
563 .write_data_binfo = nilfs_write_file_data_binfo,
564 .write_node_binfo = nilfs_write_file_node_binfo,
565 };
566
567 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
568 struct buffer_head *bh, struct inode *inode)
569 {
570 int err;
571
572 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
573 if (err < 0)
574 return err;
575
576 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
577 if (!err)
578 sci->sc_datablk_cnt++;
579 return err;
580 }
581
582 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
583 struct buffer_head *bh, struct inode *inode)
584 {
585 WARN_ON(!buffer_dirty(bh));
586 return nilfs_segctor_add_file_block(sci, bh, inode,
587 sizeof(struct nilfs_binfo_dat));
588 }
589
590 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
591 struct nilfs_segsum_pointer *ssp,
592 union nilfs_binfo *binfo)
593 {
594 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
595 sizeof(*blkoff));
596 *blkoff = binfo->bi_dat.bi_blkoff;
597 }
598
599 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
600 struct nilfs_segsum_pointer *ssp,
601 union nilfs_binfo *binfo)
602 {
603 struct nilfs_binfo_dat *binfo_dat =
604 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
605 *binfo_dat = binfo->bi_dat;
606 }
607
608 static struct nilfs_sc_operations nilfs_sc_dat_ops = {
609 .collect_data = nilfs_collect_dat_data,
610 .collect_node = nilfs_collect_file_node,
611 .collect_bmap = nilfs_collect_dat_bmap,
612 .write_data_binfo = nilfs_write_dat_data_binfo,
613 .write_node_binfo = nilfs_write_dat_node_binfo,
614 };
615
616 static struct nilfs_sc_operations nilfs_sc_dsync_ops = {
617 .collect_data = nilfs_collect_file_data,
618 .collect_node = NULL,
619 .collect_bmap = NULL,
620 .write_data_binfo = nilfs_write_file_data_binfo,
621 .write_node_binfo = NULL,
622 };
623
624 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
625 struct list_head *listp,
626 size_t nlimit,
627 loff_t start, loff_t end)
628 {
629 struct address_space *mapping = inode->i_mapping;
630 struct pagevec pvec;
631 pgoff_t index = 0, last = ULONG_MAX;
632 size_t ndirties = 0;
633 int i;
634
635 if (unlikely(start != 0 || end != LLONG_MAX)) {
636 /*
637 * A valid range is given for sync-ing data pages. The
638 * range is rounded to per-page; extra dirty buffers
639 * may be included if blocksize < pagesize.
640 */
641 index = start >> PAGE_SHIFT;
642 last = end >> PAGE_SHIFT;
643 }
644 pagevec_init(&pvec, 0);
645 repeat:
646 if (unlikely(index > last) ||
647 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
648 min_t(pgoff_t, last - index,
649 PAGEVEC_SIZE - 1) + 1))
650 return ndirties;
651
652 for (i = 0; i < pagevec_count(&pvec); i++) {
653 struct buffer_head *bh, *head;
654 struct page *page = pvec.pages[i];
655
656 if (unlikely(page->index > last))
657 break;
658
659 if (mapping->host) {
660 lock_page(page);
661 if (!page_has_buffers(page))
662 create_empty_buffers(page,
663 1 << inode->i_blkbits, 0);
664 unlock_page(page);
665 }
666
667 bh = head = page_buffers(page);
668 do {
669 if (!buffer_dirty(bh))
670 continue;
671 get_bh(bh);
672 list_add_tail(&bh->b_assoc_buffers, listp);
673 ndirties++;
674 if (unlikely(ndirties >= nlimit)) {
675 pagevec_release(&pvec);
676 cond_resched();
677 return ndirties;
678 }
679 } while (bh = bh->b_this_page, bh != head);
680 }
681 pagevec_release(&pvec);
682 cond_resched();
683 goto repeat;
684 }
685
686 static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
687 struct list_head *listp)
688 {
689 struct nilfs_inode_info *ii = NILFS_I(inode);
690 struct address_space *mapping = &ii->i_btnode_cache;
691 struct pagevec pvec;
692 struct buffer_head *bh, *head;
693 unsigned int i;
694 pgoff_t index = 0;
695
696 pagevec_init(&pvec, 0);
697
698 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
699 PAGEVEC_SIZE)) {
700 for (i = 0; i < pagevec_count(&pvec); i++) {
701 bh = head = page_buffers(pvec.pages[i]);
702 do {
703 if (buffer_dirty(bh)) {
704 get_bh(bh);
705 list_add_tail(&bh->b_assoc_buffers,
706 listp);
707 }
708 bh = bh->b_this_page;
709 } while (bh != head);
710 }
711 pagevec_release(&pvec);
712 cond_resched();
713 }
714 }
715
716 static void nilfs_dispose_list(struct nilfs_sb_info *sbi,
717 struct list_head *head, int force)
718 {
719 struct nilfs_inode_info *ii, *n;
720 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
721 unsigned nv = 0;
722
723 while (!list_empty(head)) {
724 spin_lock(&sbi->s_inode_lock);
725 list_for_each_entry_safe(ii, n, head, i_dirty) {
726 list_del_init(&ii->i_dirty);
727 if (force) {
728 if (unlikely(ii->i_bh)) {
729 brelse(ii->i_bh);
730 ii->i_bh = NULL;
731 }
732 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
733 set_bit(NILFS_I_QUEUED, &ii->i_state);
734 list_add_tail(&ii->i_dirty,
735 &sbi->s_dirty_files);
736 continue;
737 }
738 ivec[nv++] = ii;
739 if (nv == SC_N_INODEVEC)
740 break;
741 }
742 spin_unlock(&sbi->s_inode_lock);
743
744 for (pii = ivec; nv > 0; pii++, nv--)
745 iput(&(*pii)->vfs_inode);
746 }
747 }
748
749 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
750 struct nilfs_root *root)
751 {
752 int ret = 0;
753
754 if (nilfs_mdt_fetch_dirty(root->ifile))
755 ret++;
756 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
757 ret++;
758 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
759 ret++;
760 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat))
761 ret++;
762 return ret;
763 }
764
765 static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
766 {
767 return list_empty(&sci->sc_dirty_files) &&
768 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
769 sci->sc_nfreesegs == 0 &&
770 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
771 }
772
773 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
774 {
775 struct nilfs_sb_info *sbi = sci->sc_sbi;
776 int ret = 0;
777
778 if (nilfs_test_metadata_dirty(sbi->s_nilfs, sci->sc_root))
779 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
780
781 spin_lock(&sbi->s_inode_lock);
782 if (list_empty(&sbi->s_dirty_files) && nilfs_segctor_clean(sci))
783 ret++;
784
785 spin_unlock(&sbi->s_inode_lock);
786 return ret;
787 }
788
789 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
790 {
791 struct nilfs_sb_info *sbi = sci->sc_sbi;
792 struct the_nilfs *nilfs = sbi->s_nilfs;
793
794 nilfs_mdt_clear_dirty(sci->sc_root->ifile);
795 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
796 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
797 nilfs_mdt_clear_dirty(nilfs->ns_dat);
798 }
799
800 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
801 {
802 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
803 struct buffer_head *bh_cp;
804 struct nilfs_checkpoint *raw_cp;
805 int err;
806
807 /* XXX: this interface will be changed */
808 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
809 &raw_cp, &bh_cp);
810 if (likely(!err)) {
811 /* The following code is duplicated with cpfile. But, it is
812 needed to collect the checkpoint even if it was not newly
813 created */
814 nilfs_mdt_mark_buffer_dirty(bh_cp);
815 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
816 nilfs_cpfile_put_checkpoint(
817 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
818 } else
819 WARN_ON(err == -EINVAL || err == -ENOENT);
820
821 return err;
822 }
823
824 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
825 {
826 struct nilfs_sb_info *sbi = sci->sc_sbi;
827 struct the_nilfs *nilfs = sbi->s_nilfs;
828 struct buffer_head *bh_cp;
829 struct nilfs_checkpoint *raw_cp;
830 int err;
831
832 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
833 &raw_cp, &bh_cp);
834 if (unlikely(err)) {
835 WARN_ON(err == -EINVAL || err == -ENOENT);
836 goto failed_ibh;
837 }
838 raw_cp->cp_snapshot_list.ssl_next = 0;
839 raw_cp->cp_snapshot_list.ssl_prev = 0;
840 raw_cp->cp_inodes_count =
841 cpu_to_le64(atomic_read(&sci->sc_root->inodes_count));
842 raw_cp->cp_blocks_count =
843 cpu_to_le64(atomic_read(&sci->sc_root->blocks_count));
844 raw_cp->cp_nblk_inc =
845 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
846 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
847 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
848
849 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
850 nilfs_checkpoint_clear_minor(raw_cp);
851 else
852 nilfs_checkpoint_set_minor(raw_cp);
853
854 nilfs_write_inode_common(sci->sc_root->ifile,
855 &raw_cp->cp_ifile_inode, 1);
856 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
857 return 0;
858
859 failed_ibh:
860 return err;
861 }
862
863 static void nilfs_fill_in_file_bmap(struct inode *ifile,
864 struct nilfs_inode_info *ii)
865
866 {
867 struct buffer_head *ibh;
868 struct nilfs_inode *raw_inode;
869
870 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
871 ibh = ii->i_bh;
872 BUG_ON(!ibh);
873 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
874 ibh);
875 nilfs_bmap_write(ii->i_bmap, raw_inode);
876 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
877 }
878 }
879
880 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
881 {
882 struct nilfs_inode_info *ii;
883
884 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
885 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
886 set_bit(NILFS_I_COLLECTED, &ii->i_state);
887 }
888 }
889
890 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
891 struct the_nilfs *nilfs)
892 {
893 struct buffer_head *bh_sr;
894 struct nilfs_super_root *raw_sr;
895 unsigned isz = nilfs->ns_inode_size;
896
897 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
898 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
899
900 raw_sr->sr_bytes = cpu_to_le16(NILFS_SR_BYTES);
901 raw_sr->sr_nongc_ctime
902 = cpu_to_le64(nilfs_doing_gc() ?
903 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
904 raw_sr->sr_flags = 0;
905
906 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr +
907 NILFS_SR_DAT_OFFSET(isz), 1);
908 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
909 NILFS_SR_CPFILE_OFFSET(isz), 1);
910 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
911 NILFS_SR_SUFILE_OFFSET(isz), 1);
912 }
913
914 static void nilfs_redirty_inodes(struct list_head *head)
915 {
916 struct nilfs_inode_info *ii;
917
918 list_for_each_entry(ii, head, i_dirty) {
919 if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
920 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
921 }
922 }
923
924 static void nilfs_drop_collected_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_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
930 continue;
931
932 clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
933 set_bit(NILFS_I_UPDATED, &ii->i_state);
934 }
935 }
936
937 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
938 struct inode *inode,
939 struct list_head *listp,
940 int (*collect)(struct nilfs_sc_info *,
941 struct buffer_head *,
942 struct inode *))
943 {
944 struct buffer_head *bh, *n;
945 int err = 0;
946
947 if (collect) {
948 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
949 list_del_init(&bh->b_assoc_buffers);
950 err = collect(sci, bh, inode);
951 brelse(bh);
952 if (unlikely(err))
953 goto dispose_buffers;
954 }
955 return 0;
956 }
957
958 dispose_buffers:
959 while (!list_empty(listp)) {
960 bh = list_entry(listp->next, struct buffer_head,
961 b_assoc_buffers);
962 list_del_init(&bh->b_assoc_buffers);
963 brelse(bh);
964 }
965 return err;
966 }
967
968 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
969 {
970 /* Remaining number of blocks within segment buffer */
971 return sci->sc_segbuf_nblocks -
972 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
973 }
974
975 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
976 struct inode *inode,
977 struct nilfs_sc_operations *sc_ops)
978 {
979 LIST_HEAD(data_buffers);
980 LIST_HEAD(node_buffers);
981 int err;
982
983 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
984 size_t n, rest = nilfs_segctor_buffer_rest(sci);
985
986 n = nilfs_lookup_dirty_data_buffers(
987 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
988 if (n > rest) {
989 err = nilfs_segctor_apply_buffers(
990 sci, inode, &data_buffers,
991 sc_ops->collect_data);
992 BUG_ON(!err); /* always receive -E2BIG or true error */
993 goto break_or_fail;
994 }
995 }
996 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
997
998 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
999 err = nilfs_segctor_apply_buffers(
1000 sci, inode, &data_buffers, sc_ops->collect_data);
1001 if (unlikely(err)) {
1002 /* dispose node list */
1003 nilfs_segctor_apply_buffers(
1004 sci, inode, &node_buffers, NULL);
1005 goto break_or_fail;
1006 }
1007 sci->sc_stage.flags |= NILFS_CF_NODE;
1008 }
1009 /* Collect node */
1010 err = nilfs_segctor_apply_buffers(
1011 sci, inode, &node_buffers, sc_ops->collect_node);
1012 if (unlikely(err))
1013 goto break_or_fail;
1014
1015 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1016 err = nilfs_segctor_apply_buffers(
1017 sci, inode, &node_buffers, sc_ops->collect_bmap);
1018 if (unlikely(err))
1019 goto break_or_fail;
1020
1021 nilfs_segctor_end_finfo(sci, inode);
1022 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1023
1024 break_or_fail:
1025 return err;
1026 }
1027
1028 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1029 struct inode *inode)
1030 {
1031 LIST_HEAD(data_buffers);
1032 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1033 int err;
1034
1035 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1036 sci->sc_dsync_start,
1037 sci->sc_dsync_end);
1038
1039 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1040 nilfs_collect_file_data);
1041 if (!err) {
1042 nilfs_segctor_end_finfo(sci, inode);
1043 BUG_ON(n > rest);
1044 /* always receive -E2BIG or true error if n > rest */
1045 }
1046 return err;
1047 }
1048
1049 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1050 {
1051 struct nilfs_sb_info *sbi = sci->sc_sbi;
1052 struct the_nilfs *nilfs = sbi->s_nilfs;
1053 struct list_head *head;
1054 struct nilfs_inode_info *ii;
1055 size_t ndone;
1056 int err = 0;
1057
1058 switch (sci->sc_stage.scnt) {
1059 case NILFS_ST_INIT:
1060 /* Pre-processes */
1061 sci->sc_stage.flags = 0;
1062
1063 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1064 sci->sc_nblk_inc = 0;
1065 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1066 if (mode == SC_LSEG_DSYNC) {
1067 sci->sc_stage.scnt = NILFS_ST_DSYNC;
1068 goto dsync_mode;
1069 }
1070 }
1071
1072 sci->sc_stage.dirty_file_ptr = NULL;
1073 sci->sc_stage.gc_inode_ptr = NULL;
1074 if (mode == SC_FLUSH_DAT) {
1075 sci->sc_stage.scnt = NILFS_ST_DAT;
1076 goto dat_stage;
1077 }
1078 sci->sc_stage.scnt++; /* Fall through */
1079 case NILFS_ST_GC:
1080 if (nilfs_doing_gc()) {
1081 head = &sci->sc_gc_inodes;
1082 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1083 head, i_dirty);
1084 list_for_each_entry_continue(ii, head, i_dirty) {
1085 err = nilfs_segctor_scan_file(
1086 sci, &ii->vfs_inode,
1087 &nilfs_sc_file_ops);
1088 if (unlikely(err)) {
1089 sci->sc_stage.gc_inode_ptr = list_entry(
1090 ii->i_dirty.prev,
1091 struct nilfs_inode_info,
1092 i_dirty);
1093 goto break_or_fail;
1094 }
1095 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1096 }
1097 sci->sc_stage.gc_inode_ptr = NULL;
1098 }
1099 sci->sc_stage.scnt++; /* Fall through */
1100 case NILFS_ST_FILE:
1101 head = &sci->sc_dirty_files;
1102 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1103 i_dirty);
1104 list_for_each_entry_continue(ii, head, i_dirty) {
1105 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1106
1107 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1108 &nilfs_sc_file_ops);
1109 if (unlikely(err)) {
1110 sci->sc_stage.dirty_file_ptr =
1111 list_entry(ii->i_dirty.prev,
1112 struct nilfs_inode_info,
1113 i_dirty);
1114 goto break_or_fail;
1115 }
1116 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1117 /* XXX: required ? */
1118 }
1119 sci->sc_stage.dirty_file_ptr = NULL;
1120 if (mode == SC_FLUSH_FILE) {
1121 sci->sc_stage.scnt = NILFS_ST_DONE;
1122 return 0;
1123 }
1124 sci->sc_stage.scnt++;
1125 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1126 /* Fall through */
1127 case NILFS_ST_IFILE:
1128 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile,
1129 &nilfs_sc_file_ops);
1130 if (unlikely(err))
1131 break;
1132 sci->sc_stage.scnt++;
1133 /* Creating a checkpoint */
1134 err = nilfs_segctor_create_checkpoint(sci);
1135 if (unlikely(err))
1136 break;
1137 /* Fall through */
1138 case NILFS_ST_CPFILE:
1139 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1140 &nilfs_sc_file_ops);
1141 if (unlikely(err))
1142 break;
1143 sci->sc_stage.scnt++; /* Fall through */
1144 case NILFS_ST_SUFILE:
1145 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1146 sci->sc_nfreesegs, &ndone);
1147 if (unlikely(err)) {
1148 nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1149 sci->sc_freesegs, ndone,
1150 NULL);
1151 break;
1152 }
1153 sci->sc_stage.flags |= NILFS_CF_SUFREED;
1154
1155 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1156 &nilfs_sc_file_ops);
1157 if (unlikely(err))
1158 break;
1159 sci->sc_stage.scnt++; /* Fall through */
1160 case NILFS_ST_DAT:
1161 dat_stage:
1162 err = nilfs_segctor_scan_file(sci, nilfs->ns_dat,
1163 &nilfs_sc_dat_ops);
1164 if (unlikely(err))
1165 break;
1166 if (mode == SC_FLUSH_DAT) {
1167 sci->sc_stage.scnt = NILFS_ST_DONE;
1168 return 0;
1169 }
1170 sci->sc_stage.scnt++; /* Fall through */
1171 case NILFS_ST_SR:
1172 if (mode == SC_LSEG_SR) {
1173 /* Appending a super root */
1174 err = nilfs_segctor_add_super_root(sci);
1175 if (unlikely(err))
1176 break;
1177 }
1178 /* End of a logical segment */
1179 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1180 sci->sc_stage.scnt = NILFS_ST_DONE;
1181 return 0;
1182 case NILFS_ST_DSYNC:
1183 dsync_mode:
1184 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1185 ii = sci->sc_dsync_inode;
1186 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1187 break;
1188
1189 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1190 if (unlikely(err))
1191 break;
1192 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1193 sci->sc_stage.scnt = NILFS_ST_DONE;
1194 return 0;
1195 case NILFS_ST_DONE:
1196 return 0;
1197 default:
1198 BUG();
1199 }
1200
1201 break_or_fail:
1202 return err;
1203 }
1204
1205 /**
1206 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1207 * @sci: nilfs_sc_info
1208 * @nilfs: nilfs object
1209 */
1210 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1211 struct the_nilfs *nilfs)
1212 {
1213 struct nilfs_segment_buffer *segbuf, *prev;
1214 __u64 nextnum;
1215 int err, alloc = 0;
1216
1217 segbuf = nilfs_segbuf_new(sci->sc_super);
1218 if (unlikely(!segbuf))
1219 return -ENOMEM;
1220
1221 if (list_empty(&sci->sc_write_logs)) {
1222 nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1223 nilfs->ns_pseg_offset, nilfs);
1224 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1225 nilfs_shift_to_next_segment(nilfs);
1226 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1227 }
1228
1229 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1230 nextnum = nilfs->ns_nextnum;
1231
1232 if (nilfs->ns_segnum == nilfs->ns_nextnum)
1233 /* Start from the head of a new full segment */
1234 alloc++;
1235 } else {
1236 /* Continue logs */
1237 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1238 nilfs_segbuf_map_cont(segbuf, prev);
1239 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1240 nextnum = prev->sb_nextnum;
1241
1242 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1243 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1244 segbuf->sb_sum.seg_seq++;
1245 alloc++;
1246 }
1247 }
1248
1249 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1250 if (err)
1251 goto failed;
1252
1253 if (alloc) {
1254 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1255 if (err)
1256 goto failed;
1257 }
1258 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1259
1260 BUG_ON(!list_empty(&sci->sc_segbufs));
1261 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1262 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1263 return 0;
1264
1265 failed:
1266 nilfs_segbuf_free(segbuf);
1267 return err;
1268 }
1269
1270 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1271 struct the_nilfs *nilfs, int nadd)
1272 {
1273 struct nilfs_segment_buffer *segbuf, *prev;
1274 struct inode *sufile = nilfs->ns_sufile;
1275 __u64 nextnextnum;
1276 LIST_HEAD(list);
1277 int err, ret, i;
1278
1279 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1280 /*
1281 * Since the segment specified with nextnum might be allocated during
1282 * the previous construction, the buffer including its segusage may
1283 * not be dirty. The following call ensures that the buffer is dirty
1284 * and will pin the buffer on memory until the sufile is written.
1285 */
1286 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1287 if (unlikely(err))
1288 return err;
1289
1290 for (i = 0; i < nadd; i++) {
1291 /* extend segment info */
1292 err = -ENOMEM;
1293 segbuf = nilfs_segbuf_new(sci->sc_super);
1294 if (unlikely(!segbuf))
1295 goto failed;
1296
1297 /* map this buffer to region of segment on-disk */
1298 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1299 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1300
1301 /* allocate the next next full segment */
1302 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1303 if (unlikely(err))
1304 goto failed_segbuf;
1305
1306 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1307 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1308
1309 list_add_tail(&segbuf->sb_list, &list);
1310 prev = segbuf;
1311 }
1312 list_splice_tail(&list, &sci->sc_segbufs);
1313 return 0;
1314
1315 failed_segbuf:
1316 nilfs_segbuf_free(segbuf);
1317 failed:
1318 list_for_each_entry(segbuf, &list, sb_list) {
1319 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1320 WARN_ON(ret); /* never fails */
1321 }
1322 nilfs_destroy_logs(&list);
1323 return err;
1324 }
1325
1326 static void nilfs_free_incomplete_logs(struct list_head *logs,
1327 struct the_nilfs *nilfs)
1328 {
1329 struct nilfs_segment_buffer *segbuf, *prev;
1330 struct inode *sufile = nilfs->ns_sufile;
1331 int ret;
1332
1333 segbuf = NILFS_FIRST_SEGBUF(logs);
1334 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1335 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1336 WARN_ON(ret); /* never fails */
1337 }
1338 if (atomic_read(&segbuf->sb_err)) {
1339 /* Case 1: The first segment failed */
1340 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1341 /* Case 1a: Partial segment appended into an existing
1342 segment */
1343 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1344 segbuf->sb_fseg_end);
1345 else /* Case 1b: New full segment */
1346 set_nilfs_discontinued(nilfs);
1347 }
1348
1349 prev = segbuf;
1350 list_for_each_entry_continue(segbuf, logs, sb_list) {
1351 if (prev->sb_nextnum != segbuf->sb_nextnum) {
1352 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1353 WARN_ON(ret); /* never fails */
1354 }
1355 if (atomic_read(&segbuf->sb_err) &&
1356 segbuf->sb_segnum != nilfs->ns_nextnum)
1357 /* Case 2: extended segment (!= next) failed */
1358 nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1359 prev = segbuf;
1360 }
1361 }
1362
1363 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1364 struct inode *sufile)
1365 {
1366 struct nilfs_segment_buffer *segbuf;
1367 unsigned long live_blocks;
1368 int ret;
1369
1370 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1371 live_blocks = segbuf->sb_sum.nblocks +
1372 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1373 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1374 live_blocks,
1375 sci->sc_seg_ctime);
1376 WARN_ON(ret); /* always succeed because the segusage is dirty */
1377 }
1378 }
1379
1380 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1381 {
1382 struct nilfs_segment_buffer *segbuf;
1383 int ret;
1384
1385 segbuf = NILFS_FIRST_SEGBUF(logs);
1386 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1387 segbuf->sb_pseg_start -
1388 segbuf->sb_fseg_start, 0);
1389 WARN_ON(ret); /* always succeed because the segusage is dirty */
1390
1391 list_for_each_entry_continue(segbuf, logs, sb_list) {
1392 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1393 0, 0);
1394 WARN_ON(ret); /* always succeed */
1395 }
1396 }
1397
1398 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1399 struct nilfs_segment_buffer *last,
1400 struct inode *sufile)
1401 {
1402 struct nilfs_segment_buffer *segbuf = last;
1403 int ret;
1404
1405 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1406 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1407 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1408 WARN_ON(ret);
1409 }
1410 nilfs_truncate_logs(&sci->sc_segbufs, last);
1411 }
1412
1413
1414 static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1415 struct the_nilfs *nilfs, int mode)
1416 {
1417 struct nilfs_cstage prev_stage = sci->sc_stage;
1418 int err, nadd = 1;
1419
1420 /* Collection retry loop */
1421 for (;;) {
1422 sci->sc_nblk_this_inc = 0;
1423 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1424
1425 err = nilfs_segctor_reset_segment_buffer(sci);
1426 if (unlikely(err))
1427 goto failed;
1428
1429 err = nilfs_segctor_collect_blocks(sci, mode);
1430 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1431 if (!err)
1432 break;
1433
1434 if (unlikely(err != -E2BIG))
1435 goto failed;
1436
1437 /* The current segment is filled up */
1438 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
1439 break;
1440
1441 nilfs_clear_logs(&sci->sc_segbufs);
1442
1443 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1444 if (unlikely(err))
1445 return err;
1446
1447 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1448 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1449 sci->sc_freesegs,
1450 sci->sc_nfreesegs,
1451 NULL);
1452 WARN_ON(err); /* do not happen */
1453 }
1454 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1455 sci->sc_stage = prev_stage;
1456 }
1457 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1458 return 0;
1459
1460 failed:
1461 return err;
1462 }
1463
1464 static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1465 struct buffer_head *new_bh)
1466 {
1467 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1468
1469 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1470 /* The caller must release old_bh */
1471 }
1472
1473 static int
1474 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1475 struct nilfs_segment_buffer *segbuf,
1476 int mode)
1477 {
1478 struct inode *inode = NULL;
1479 sector_t blocknr;
1480 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1481 unsigned long nblocks = 0, ndatablk = 0;
1482 struct nilfs_sc_operations *sc_op = NULL;
1483 struct nilfs_segsum_pointer ssp;
1484 struct nilfs_finfo *finfo = NULL;
1485 union nilfs_binfo binfo;
1486 struct buffer_head *bh, *bh_org;
1487 ino_t ino = 0;
1488 int err = 0;
1489
1490 if (!nfinfo)
1491 goto out;
1492
1493 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1494 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1495 ssp.offset = sizeof(struct nilfs_segment_summary);
1496
1497 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1498 if (bh == segbuf->sb_super_root)
1499 break;
1500 if (!finfo) {
1501 finfo = nilfs_segctor_map_segsum_entry(
1502 sci, &ssp, sizeof(*finfo));
1503 ino = le64_to_cpu(finfo->fi_ino);
1504 nblocks = le32_to_cpu(finfo->fi_nblocks);
1505 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1506
1507 if (buffer_nilfs_node(bh))
1508 inode = NILFS_BTNC_I(bh->b_page->mapping);
1509 else
1510 inode = NILFS_AS_I(bh->b_page->mapping);
1511
1512 if (mode == SC_LSEG_DSYNC)
1513 sc_op = &nilfs_sc_dsync_ops;
1514 else if (ino == NILFS_DAT_INO)
1515 sc_op = &nilfs_sc_dat_ops;
1516 else /* file blocks */
1517 sc_op = &nilfs_sc_file_ops;
1518 }
1519 bh_org = bh;
1520 get_bh(bh_org);
1521 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1522 &binfo);
1523 if (bh != bh_org)
1524 nilfs_list_replace_buffer(bh_org, bh);
1525 brelse(bh_org);
1526 if (unlikely(err))
1527 goto failed_bmap;
1528
1529 if (ndatablk > 0)
1530 sc_op->write_data_binfo(sci, &ssp, &binfo);
1531 else
1532 sc_op->write_node_binfo(sci, &ssp, &binfo);
1533
1534 blocknr++;
1535 if (--nblocks == 0) {
1536 finfo = NULL;
1537 if (--nfinfo == 0)
1538 break;
1539 } else if (ndatablk > 0)
1540 ndatablk--;
1541 }
1542 out:
1543 return 0;
1544
1545 failed_bmap:
1546 return err;
1547 }
1548
1549 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1550 {
1551 struct nilfs_segment_buffer *segbuf;
1552 int err;
1553
1554 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1555 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1556 if (unlikely(err))
1557 return err;
1558 nilfs_segbuf_fill_in_segsum(segbuf);
1559 }
1560 return 0;
1561 }
1562
1563 static int
1564 nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out)
1565 {
1566 struct page *clone_page;
1567 struct buffer_head *bh, *head, *bh2;
1568 void *kaddr;
1569
1570 bh = head = page_buffers(page);
1571
1572 clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0);
1573 if (unlikely(!clone_page))
1574 return -ENOMEM;
1575
1576 bh2 = page_buffers(clone_page);
1577 kaddr = kmap_atomic(page, KM_USER0);
1578 do {
1579 if (list_empty(&bh->b_assoc_buffers))
1580 continue;
1581 get_bh(bh2);
1582 page_cache_get(clone_page); /* for each bh */
1583 memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size);
1584 bh2->b_blocknr = bh->b_blocknr;
1585 list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers);
1586 list_add_tail(&bh->b_assoc_buffers, out);
1587 } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head);
1588 kunmap_atomic(kaddr, KM_USER0);
1589
1590 if (!TestSetPageWriteback(clone_page))
1591 account_page_writeback(clone_page);
1592 unlock_page(clone_page);
1593
1594 return 0;
1595 }
1596
1597 static int nilfs_test_page_to_be_frozen(struct page *page)
1598 {
1599 struct address_space *mapping = page->mapping;
1600
1601 if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode))
1602 return 0;
1603
1604 if (page_mapped(page)) {
1605 ClearPageChecked(page);
1606 return 1;
1607 }
1608 return PageChecked(page);
1609 }
1610
1611 static int nilfs_begin_page_io(struct page *page, struct list_head *out)
1612 {
1613 if (!page || PageWriteback(page))
1614 /* For split b-tree node pages, this function may be called
1615 twice. We ignore the 2nd or later calls by this check. */
1616 return 0;
1617
1618 lock_page(page);
1619 clear_page_dirty_for_io(page);
1620 set_page_writeback(page);
1621 unlock_page(page);
1622
1623 if (nilfs_test_page_to_be_frozen(page)) {
1624 int err = nilfs_copy_replace_page_buffers(page, out);
1625 if (unlikely(err))
1626 return err;
1627 }
1628 return 0;
1629 }
1630
1631 static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
1632 struct page **failed_page)
1633 {
1634 struct nilfs_segment_buffer *segbuf;
1635 struct page *bd_page = NULL, *fs_page = NULL;
1636 struct list_head *list = &sci->sc_copied_buffers;
1637 int err;
1638
1639 *failed_page = NULL;
1640 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1641 struct buffer_head *bh;
1642
1643 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1644 b_assoc_buffers) {
1645 if (bh->b_page != bd_page) {
1646 if (bd_page) {
1647 lock_page(bd_page);
1648 clear_page_dirty_for_io(bd_page);
1649 set_page_writeback(bd_page);
1650 unlock_page(bd_page);
1651 }
1652 bd_page = bh->b_page;
1653 }
1654 }
1655
1656 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1657 b_assoc_buffers) {
1658 if (bh == segbuf->sb_super_root) {
1659 if (bh->b_page != bd_page) {
1660 lock_page(bd_page);
1661 clear_page_dirty_for_io(bd_page);
1662 set_page_writeback(bd_page);
1663 unlock_page(bd_page);
1664 bd_page = bh->b_page;
1665 }
1666 break;
1667 }
1668 if (bh->b_page != fs_page) {
1669 err = nilfs_begin_page_io(fs_page, list);
1670 if (unlikely(err)) {
1671 *failed_page = fs_page;
1672 goto out;
1673 }
1674 fs_page = bh->b_page;
1675 }
1676 }
1677 }
1678 if (bd_page) {
1679 lock_page(bd_page);
1680 clear_page_dirty_for_io(bd_page);
1681 set_page_writeback(bd_page);
1682 unlock_page(bd_page);
1683 }
1684 err = nilfs_begin_page_io(fs_page, list);
1685 if (unlikely(err))
1686 *failed_page = fs_page;
1687 out:
1688 return err;
1689 }
1690
1691 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1692 struct the_nilfs *nilfs)
1693 {
1694 int ret;
1695
1696 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1697 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1698 return ret;
1699 }
1700
1701 static void __nilfs_end_page_io(struct page *page, int err)
1702 {
1703 if (!err) {
1704 if (!nilfs_page_buffers_clean(page))
1705 __set_page_dirty_nobuffers(page);
1706 ClearPageError(page);
1707 } else {
1708 __set_page_dirty_nobuffers(page);
1709 SetPageError(page);
1710 }
1711
1712 if (buffer_nilfs_allocated(page_buffers(page))) {
1713 if (TestClearPageWriteback(page))
1714 dec_zone_page_state(page, NR_WRITEBACK);
1715 } else
1716 end_page_writeback(page);
1717 }
1718
1719 static void nilfs_end_page_io(struct page *page, int err)
1720 {
1721 if (!page)
1722 return;
1723
1724 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
1725 /*
1726 * For b-tree node pages, this function may be called twice
1727 * or more because they might be split in a segment.
1728 */
1729 if (PageDirty(page)) {
1730 /*
1731 * For pages holding split b-tree node buffers, dirty
1732 * flag on the buffers may be cleared discretely.
1733 * In that case, the page is once redirtied for
1734 * remaining buffers, and it must be cancelled if
1735 * all the buffers get cleaned later.
1736 */
1737 lock_page(page);
1738 if (nilfs_page_buffers_clean(page))
1739 __nilfs_clear_page_dirty(page);
1740 unlock_page(page);
1741 }
1742 return;
1743 }
1744
1745 __nilfs_end_page_io(page, err);
1746 }
1747
1748 static void nilfs_clear_copied_buffers(struct list_head *list, int err)
1749 {
1750 struct buffer_head *bh, *head;
1751 struct page *page;
1752
1753 while (!list_empty(list)) {
1754 bh = list_entry(list->next, struct buffer_head,
1755 b_assoc_buffers);
1756 page = bh->b_page;
1757 page_cache_get(page);
1758 head = bh = page_buffers(page);
1759 do {
1760 if (!list_empty(&bh->b_assoc_buffers)) {
1761 list_del_init(&bh->b_assoc_buffers);
1762 if (!err) {
1763 set_buffer_uptodate(bh);
1764 clear_buffer_dirty(bh);
1765 clear_buffer_delay(bh);
1766 clear_buffer_nilfs_volatile(bh);
1767 }
1768 brelse(bh); /* for b_assoc_buffers */
1769 }
1770 } while ((bh = bh->b_this_page) != head);
1771
1772 __nilfs_end_page_io(page, err);
1773 page_cache_release(page);
1774 }
1775 }
1776
1777 static void nilfs_abort_logs(struct list_head *logs, struct page *failed_page,
1778 int err)
1779 {
1780 struct nilfs_segment_buffer *segbuf;
1781 struct page *bd_page = NULL, *fs_page = NULL;
1782 struct buffer_head *bh;
1783
1784 if (list_empty(logs))
1785 return;
1786
1787 list_for_each_entry(segbuf, logs, sb_list) {
1788 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1789 b_assoc_buffers) {
1790 if (bh->b_page != bd_page) {
1791 if (bd_page)
1792 end_page_writeback(bd_page);
1793 bd_page = bh->b_page;
1794 }
1795 }
1796
1797 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1798 b_assoc_buffers) {
1799 if (bh == segbuf->sb_super_root) {
1800 if (bh->b_page != bd_page) {
1801 end_page_writeback(bd_page);
1802 bd_page = bh->b_page;
1803 }
1804 break;
1805 }
1806 if (bh->b_page != fs_page) {
1807 nilfs_end_page_io(fs_page, err);
1808 if (fs_page && fs_page == failed_page)
1809 return;
1810 fs_page = bh->b_page;
1811 }
1812 }
1813 }
1814 if (bd_page)
1815 end_page_writeback(bd_page);
1816
1817 nilfs_end_page_io(fs_page, err);
1818 }
1819
1820 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1821 struct the_nilfs *nilfs, int err)
1822 {
1823 LIST_HEAD(logs);
1824 int ret;
1825
1826 list_splice_tail_init(&sci->sc_write_logs, &logs);
1827 ret = nilfs_wait_on_logs(&logs);
1828 nilfs_abort_logs(&logs, NULL, ret ? : err);
1829
1830 list_splice_tail_init(&sci->sc_segbufs, &logs);
1831 nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1832 nilfs_free_incomplete_logs(&logs, nilfs);
1833 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err);
1834
1835 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1836 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1837 sci->sc_freesegs,
1838 sci->sc_nfreesegs,
1839 NULL);
1840 WARN_ON(ret); /* do not happen */
1841 }
1842
1843 nilfs_destroy_logs(&logs);
1844 }
1845
1846 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1847 struct nilfs_segment_buffer *segbuf)
1848 {
1849 nilfs->ns_segnum = segbuf->sb_segnum;
1850 nilfs->ns_nextnum = segbuf->sb_nextnum;
1851 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1852 + segbuf->sb_sum.nblocks;
1853 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1854 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1855 }
1856
1857 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1858 {
1859 struct nilfs_segment_buffer *segbuf;
1860 struct page *bd_page = NULL, *fs_page = NULL;
1861 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
1862 int update_sr = false;
1863
1864 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1865 struct buffer_head *bh;
1866
1867 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1868 b_assoc_buffers) {
1869 set_buffer_uptodate(bh);
1870 clear_buffer_dirty(bh);
1871 if (bh->b_page != bd_page) {
1872 if (bd_page)
1873 end_page_writeback(bd_page);
1874 bd_page = bh->b_page;
1875 }
1876 }
1877 /*
1878 * We assume that the buffers which belong to the same page
1879 * continue over the buffer list.
1880 * Under this assumption, the last BHs of pages is
1881 * identifiable by the discontinuity of bh->b_page
1882 * (page != fs_page).
1883 *
1884 * For B-tree node blocks, however, this assumption is not
1885 * guaranteed. The cleanup code of B-tree node pages needs
1886 * special care.
1887 */
1888 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1889 b_assoc_buffers) {
1890 set_buffer_uptodate(bh);
1891 clear_buffer_dirty(bh);
1892 clear_buffer_delay(bh);
1893 clear_buffer_nilfs_volatile(bh);
1894 clear_buffer_nilfs_redirected(bh);
1895 if (bh == segbuf->sb_super_root) {
1896 if (bh->b_page != bd_page) {
1897 end_page_writeback(bd_page);
1898 bd_page = bh->b_page;
1899 }
1900 update_sr = true;
1901 break;
1902 }
1903 if (bh->b_page != fs_page) {
1904 nilfs_end_page_io(fs_page, 0);
1905 fs_page = bh->b_page;
1906 }
1907 }
1908
1909 if (!nilfs_segbuf_simplex(segbuf)) {
1910 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
1911 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1912 sci->sc_lseg_stime = jiffies;
1913 }
1914 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
1915 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1916 }
1917 }
1918 /*
1919 * Since pages may continue over multiple segment buffers,
1920 * end of the last page must be checked outside of the loop.
1921 */
1922 if (bd_page)
1923 end_page_writeback(bd_page);
1924
1925 nilfs_end_page_io(fs_page, 0);
1926
1927 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, 0);
1928
1929 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1930
1931 if (nilfs_doing_gc())
1932 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1933 else
1934 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1935
1936 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1937
1938 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1939 nilfs_set_next_segment(nilfs, segbuf);
1940
1941 if (update_sr) {
1942 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
1943 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
1944
1945 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
1946 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1947 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1948 nilfs_segctor_clear_metadata_dirty(sci);
1949 } else
1950 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1951 }
1952
1953 static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
1954 {
1955 int ret;
1956
1957 ret = nilfs_wait_on_logs(&sci->sc_write_logs);
1958 if (!ret) {
1959 nilfs_segctor_complete_write(sci);
1960 nilfs_destroy_logs(&sci->sc_write_logs);
1961 }
1962 return ret;
1963 }
1964
1965 static int nilfs_segctor_check_in_files(struct nilfs_sc_info *sci,
1966 struct nilfs_sb_info *sbi)
1967 {
1968 struct nilfs_inode_info *ii, *n;
1969 struct inode *ifile = sci->sc_root->ifile;
1970
1971 spin_lock(&sbi->s_inode_lock);
1972 retry:
1973 list_for_each_entry_safe(ii, n, &sbi->s_dirty_files, i_dirty) {
1974 if (!ii->i_bh) {
1975 struct buffer_head *ibh;
1976 int err;
1977
1978 spin_unlock(&sbi->s_inode_lock);
1979 err = nilfs_ifile_get_inode_block(
1980 ifile, ii->vfs_inode.i_ino, &ibh);
1981 if (unlikely(err)) {
1982 nilfs_warning(sbi->s_super, __func__,
1983 "failed to get inode block.\n");
1984 return err;
1985 }
1986 nilfs_mdt_mark_buffer_dirty(ibh);
1987 nilfs_mdt_mark_dirty(ifile);
1988 spin_lock(&sbi->s_inode_lock);
1989 if (likely(!ii->i_bh))
1990 ii->i_bh = ibh;
1991 else
1992 brelse(ibh);
1993 goto retry;
1994 }
1995
1996 clear_bit(NILFS_I_QUEUED, &ii->i_state);
1997 set_bit(NILFS_I_BUSY, &ii->i_state);
1998 list_del(&ii->i_dirty);
1999 list_add_tail(&ii->i_dirty, &sci->sc_dirty_files);
2000 }
2001 spin_unlock(&sbi->s_inode_lock);
2002
2003 return 0;
2004 }
2005
2006 static void nilfs_segctor_check_out_files(struct nilfs_sc_info *sci,
2007 struct nilfs_sb_info *sbi)
2008 {
2009 struct nilfs_transaction_info *ti = current->journal_info;
2010 struct nilfs_inode_info *ii, *n;
2011
2012 spin_lock(&sbi->s_inode_lock);
2013 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
2014 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
2015 test_bit(NILFS_I_DIRTY, &ii->i_state))
2016 continue;
2017
2018 clear_bit(NILFS_I_BUSY, &ii->i_state);
2019 brelse(ii->i_bh);
2020 ii->i_bh = NULL;
2021 list_del(&ii->i_dirty);
2022 list_add_tail(&ii->i_dirty, &ti->ti_garbage);
2023 }
2024 spin_unlock(&sbi->s_inode_lock);
2025 }
2026
2027 /*
2028 * Main procedure of segment constructor
2029 */
2030 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2031 {
2032 struct nilfs_sb_info *sbi = sci->sc_sbi;
2033 struct the_nilfs *nilfs = sbi->s_nilfs;
2034 struct page *failed_page;
2035 int err;
2036
2037 sci->sc_stage.scnt = NILFS_ST_INIT;
2038 sci->sc_cno = nilfs->ns_cno;
2039
2040 err = nilfs_segctor_check_in_files(sci, sbi);
2041 if (unlikely(err))
2042 goto out;
2043
2044 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
2045 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2046
2047 if (nilfs_segctor_clean(sci))
2048 goto out;
2049
2050 do {
2051 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2052
2053 err = nilfs_segctor_begin_construction(sci, nilfs);
2054 if (unlikely(err))
2055 goto out;
2056
2057 /* Update time stamp */
2058 sci->sc_seg_ctime = get_seconds();
2059
2060 err = nilfs_segctor_collect(sci, nilfs, mode);
2061 if (unlikely(err))
2062 goto failed;
2063
2064 /* Avoid empty segment */
2065 if (sci->sc_stage.scnt == NILFS_ST_DONE &&
2066 nilfs_segbuf_empty(sci->sc_curseg)) {
2067 nilfs_segctor_abort_construction(sci, nilfs, 1);
2068 goto out;
2069 }
2070
2071 err = nilfs_segctor_assign(sci, mode);
2072 if (unlikely(err))
2073 goto failed;
2074
2075 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2076 nilfs_segctor_fill_in_file_bmap(sci);
2077
2078 if (mode == SC_LSEG_SR &&
2079 sci->sc_stage.scnt >= NILFS_ST_CPFILE) {
2080 err = nilfs_segctor_fill_in_checkpoint(sci);
2081 if (unlikely(err))
2082 goto failed_to_write;
2083
2084 nilfs_segctor_fill_in_super_root(sci, nilfs);
2085 }
2086 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2087
2088 /* Write partial segments */
2089 err = nilfs_segctor_prepare_write(sci, &failed_page);
2090 if (err) {
2091 nilfs_abort_logs(&sci->sc_segbufs, failed_page, err);
2092 goto failed_to_write;
2093 }
2094
2095 nilfs_add_checksums_on_logs(&sci->sc_segbufs,
2096 nilfs->ns_crc_seed);
2097
2098 err = nilfs_segctor_write(sci, nilfs);
2099 if (unlikely(err))
2100 goto failed_to_write;
2101
2102 if (sci->sc_stage.scnt == NILFS_ST_DONE ||
2103 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
2104 /*
2105 * At this point, we avoid double buffering
2106 * for blocksize < pagesize because page dirty
2107 * flag is turned off during write and dirty
2108 * buffers are not properly collected for
2109 * pages crossing over segments.
2110 */
2111 err = nilfs_segctor_wait(sci);
2112 if (err)
2113 goto failed_to_write;
2114 }
2115 } while (sci->sc_stage.scnt != NILFS_ST_DONE);
2116
2117 out:
2118 nilfs_segctor_check_out_files(sci, sbi);
2119 return err;
2120
2121 failed_to_write:
2122 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2123 nilfs_redirty_inodes(&sci->sc_dirty_files);
2124
2125 failed:
2126 if (nilfs_doing_gc())
2127 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2128 nilfs_segctor_abort_construction(sci, nilfs, err);
2129 goto out;
2130 }
2131
2132 /**
2133 * nilfs_segctor_start_timer - set timer of background write
2134 * @sci: nilfs_sc_info
2135 *
2136 * If the timer has already been set, it ignores the new request.
2137 * This function MUST be called within a section locking the segment
2138 * semaphore.
2139 */
2140 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2141 {
2142 spin_lock(&sci->sc_state_lock);
2143 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2144 sci->sc_timer.expires = jiffies + sci->sc_interval;
2145 add_timer(&sci->sc_timer);
2146 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2147 }
2148 spin_unlock(&sci->sc_state_lock);
2149 }
2150
2151 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2152 {
2153 spin_lock(&sci->sc_state_lock);
2154 if (!(sci->sc_flush_request & (1 << bn))) {
2155 unsigned long prev_req = sci->sc_flush_request;
2156
2157 sci->sc_flush_request |= (1 << bn);
2158 if (!prev_req)
2159 wake_up(&sci->sc_wait_daemon);
2160 }
2161 spin_unlock(&sci->sc_state_lock);
2162 }
2163
2164 /**
2165 * nilfs_flush_segment - trigger a segment construction for resource control
2166 * @sb: super block
2167 * @ino: inode number of the file to be flushed out.
2168 */
2169 void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2170 {
2171 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2172 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2173
2174 if (!sci || nilfs_doing_construction())
2175 return;
2176 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2177 /* assign bit 0 to data files */
2178 }
2179
2180 struct nilfs_segctor_wait_request {
2181 wait_queue_t wq;
2182 __u32 seq;
2183 int err;
2184 atomic_t done;
2185 };
2186
2187 static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2188 {
2189 struct nilfs_segctor_wait_request wait_req;
2190 int err = 0;
2191
2192 spin_lock(&sci->sc_state_lock);
2193 init_wait(&wait_req.wq);
2194 wait_req.err = 0;
2195 atomic_set(&wait_req.done, 0);
2196 wait_req.seq = ++sci->sc_seq_request;
2197 spin_unlock(&sci->sc_state_lock);
2198
2199 init_waitqueue_entry(&wait_req.wq, current);
2200 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2201 set_current_state(TASK_INTERRUPTIBLE);
2202 wake_up(&sci->sc_wait_daemon);
2203
2204 for (;;) {
2205 if (atomic_read(&wait_req.done)) {
2206 err = wait_req.err;
2207 break;
2208 }
2209 if (!signal_pending(current)) {
2210 schedule();
2211 continue;
2212 }
2213 err = -ERESTARTSYS;
2214 break;
2215 }
2216 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2217 return err;
2218 }
2219
2220 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2221 {
2222 struct nilfs_segctor_wait_request *wrq, *n;
2223 unsigned long flags;
2224
2225 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2226 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2227 wq.task_list) {
2228 if (!atomic_read(&wrq->done) &&
2229 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2230 wrq->err = err;
2231 atomic_set(&wrq->done, 1);
2232 }
2233 if (atomic_read(&wrq->done)) {
2234 wrq->wq.func(&wrq->wq,
2235 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2236 0, NULL);
2237 }
2238 }
2239 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2240 }
2241
2242 /**
2243 * nilfs_construct_segment - construct a logical segment
2244 * @sb: super block
2245 *
2246 * Return Value: On success, 0 is retured. On errors, one of the following
2247 * negative error code is returned.
2248 *
2249 * %-EROFS - Read only filesystem.
2250 *
2251 * %-EIO - I/O error
2252 *
2253 * %-ENOSPC - No space left on device (only in a panic state).
2254 *
2255 * %-ERESTARTSYS - Interrupted.
2256 *
2257 * %-ENOMEM - Insufficient memory available.
2258 */
2259 int nilfs_construct_segment(struct super_block *sb)
2260 {
2261 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2262 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2263 struct nilfs_transaction_info *ti;
2264 int err;
2265
2266 if (!sci)
2267 return -EROFS;
2268
2269 /* A call inside transactions causes a deadlock. */
2270 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2271
2272 err = nilfs_segctor_sync(sci);
2273 return err;
2274 }
2275
2276 /**
2277 * nilfs_construct_dsync_segment - construct a data-only logical segment
2278 * @sb: super block
2279 * @inode: inode whose data blocks should be written out
2280 * @start: start byte offset
2281 * @end: end byte offset (inclusive)
2282 *
2283 * Return Value: On success, 0 is retured. On errors, one of the following
2284 * negative error code is returned.
2285 *
2286 * %-EROFS - Read only filesystem.
2287 *
2288 * %-EIO - I/O error
2289 *
2290 * %-ENOSPC - No space left on device (only in a panic state).
2291 *
2292 * %-ERESTARTSYS - Interrupted.
2293 *
2294 * %-ENOMEM - Insufficient memory available.
2295 */
2296 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2297 loff_t start, loff_t end)
2298 {
2299 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2300 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2301 struct nilfs_inode_info *ii;
2302 struct nilfs_transaction_info ti;
2303 int err = 0;
2304
2305 if (!sci)
2306 return -EROFS;
2307
2308 nilfs_transaction_lock(sbi, &ti, 0);
2309
2310 ii = NILFS_I(inode);
2311 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
2312 nilfs_test_opt(sbi, STRICT_ORDER) ||
2313 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2314 nilfs_discontinued(sbi->s_nilfs)) {
2315 nilfs_transaction_unlock(sbi);
2316 err = nilfs_segctor_sync(sci);
2317 return err;
2318 }
2319
2320 spin_lock(&sbi->s_inode_lock);
2321 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2322 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2323 spin_unlock(&sbi->s_inode_lock);
2324 nilfs_transaction_unlock(sbi);
2325 return 0;
2326 }
2327 spin_unlock(&sbi->s_inode_lock);
2328 sci->sc_dsync_inode = ii;
2329 sci->sc_dsync_start = start;
2330 sci->sc_dsync_end = end;
2331
2332 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2333
2334 nilfs_transaction_unlock(sbi);
2335 return err;
2336 }
2337
2338 #define FLUSH_FILE_BIT (0x1) /* data file only */
2339 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2340
2341 /**
2342 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2343 * @sci: segment constructor object
2344 */
2345 static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2346 {
2347 spin_lock(&sci->sc_state_lock);
2348 sci->sc_seq_accepted = sci->sc_seq_request;
2349 spin_unlock(&sci->sc_state_lock);
2350 del_timer_sync(&sci->sc_timer);
2351 }
2352
2353 /**
2354 * nilfs_segctor_notify - notify the result of request to caller threads
2355 * @sci: segment constructor object
2356 * @mode: mode of log forming
2357 * @err: error code to be notified
2358 */
2359 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2360 {
2361 /* Clear requests (even when the construction failed) */
2362 spin_lock(&sci->sc_state_lock);
2363
2364 if (mode == SC_LSEG_SR) {
2365 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2366 sci->sc_seq_done = sci->sc_seq_accepted;
2367 nilfs_segctor_wakeup(sci, err);
2368 sci->sc_flush_request = 0;
2369 } else {
2370 if (mode == SC_FLUSH_FILE)
2371 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2372 else if (mode == SC_FLUSH_DAT)
2373 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2374
2375 /* re-enable timer if checkpoint creation was not done */
2376 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2377 time_before(jiffies, sci->sc_timer.expires))
2378 add_timer(&sci->sc_timer);
2379 }
2380 spin_unlock(&sci->sc_state_lock);
2381 }
2382
2383 /**
2384 * nilfs_segctor_construct - form logs and write them to disk
2385 * @sci: segment constructor object
2386 * @mode: mode of log forming
2387 */
2388 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2389 {
2390 struct nilfs_sb_info *sbi = sci->sc_sbi;
2391 struct the_nilfs *nilfs = sbi->s_nilfs;
2392 struct nilfs_super_block **sbp;
2393 int err = 0;
2394
2395 nilfs_segctor_accept(sci);
2396
2397 if (nilfs_discontinued(nilfs))
2398 mode = SC_LSEG_SR;
2399 if (!nilfs_segctor_confirm(sci))
2400 err = nilfs_segctor_do_construct(sci, mode);
2401
2402 if (likely(!err)) {
2403 if (mode != SC_FLUSH_DAT)
2404 atomic_set(&nilfs->ns_ndirtyblks, 0);
2405 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2406 nilfs_discontinued(nilfs)) {
2407 down_write(&nilfs->ns_sem);
2408 err = -EIO;
2409 sbp = nilfs_prepare_super(sbi,
2410 nilfs_sb_will_flip(nilfs));
2411 if (likely(sbp)) {
2412 nilfs_set_log_cursor(sbp[0], nilfs);
2413 err = nilfs_commit_super(sbi, NILFS_SB_COMMIT);
2414 }
2415 up_write(&nilfs->ns_sem);
2416 }
2417 }
2418
2419 nilfs_segctor_notify(sci, mode, err);
2420 return err;
2421 }
2422
2423 static void nilfs_construction_timeout(unsigned long data)
2424 {
2425 struct task_struct *p = (struct task_struct *)data;
2426 wake_up_process(p);
2427 }
2428
2429 static void
2430 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2431 {
2432 struct nilfs_inode_info *ii, *n;
2433
2434 list_for_each_entry_safe(ii, n, head, i_dirty) {
2435 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2436 continue;
2437 list_del_init(&ii->i_dirty);
2438 iput(&ii->vfs_inode);
2439 }
2440 }
2441
2442 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2443 void **kbufs)
2444 {
2445 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2446 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2447 struct the_nilfs *nilfs = sbi->s_nilfs;
2448 struct nilfs_transaction_info ti;
2449 int err;
2450
2451 if (unlikely(!sci))
2452 return -EROFS;
2453
2454 nilfs_transaction_lock(sbi, &ti, 1);
2455
2456 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2457 if (unlikely(err))
2458 goto out_unlock;
2459
2460 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2461 if (unlikely(err)) {
2462 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2463 goto out_unlock;
2464 }
2465
2466 sci->sc_freesegs = kbufs[4];
2467 sci->sc_nfreesegs = argv[4].v_nmembs;
2468 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2469
2470 for (;;) {
2471 err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2472 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2473
2474 if (likely(!err))
2475 break;
2476
2477 nilfs_warning(sb, __func__,
2478 "segment construction failed. (err=%d)", err);
2479 set_current_state(TASK_INTERRUPTIBLE);
2480 schedule_timeout(sci->sc_interval);
2481 }
2482 if (nilfs_test_opt(sbi, DISCARD)) {
2483 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2484 sci->sc_nfreesegs);
2485 if (ret) {
2486 printk(KERN_WARNING
2487 "NILFS warning: error %d on discard request, "
2488 "turning discards off for the device\n", ret);
2489 nilfs_clear_opt(sbi, DISCARD);
2490 }
2491 }
2492
2493 out_unlock:
2494 sci->sc_freesegs = NULL;
2495 sci->sc_nfreesegs = 0;
2496 nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2497 nilfs_transaction_unlock(sbi);
2498 return err;
2499 }
2500
2501 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2502 {
2503 struct nilfs_sb_info *sbi = sci->sc_sbi;
2504 struct nilfs_transaction_info ti;
2505
2506 nilfs_transaction_lock(sbi, &ti, 0);
2507 nilfs_segctor_construct(sci, mode);
2508
2509 /*
2510 * Unclosed segment should be retried. We do this using sc_timer.
2511 * Timeout of sc_timer will invoke complete construction which leads
2512 * to close the current logical segment.
2513 */
2514 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2515 nilfs_segctor_start_timer(sci);
2516
2517 nilfs_transaction_unlock(sbi);
2518 }
2519
2520 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2521 {
2522 int mode = 0;
2523 int err;
2524
2525 spin_lock(&sci->sc_state_lock);
2526 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2527 SC_FLUSH_DAT : SC_FLUSH_FILE;
2528 spin_unlock(&sci->sc_state_lock);
2529
2530 if (mode) {
2531 err = nilfs_segctor_do_construct(sci, mode);
2532
2533 spin_lock(&sci->sc_state_lock);
2534 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2535 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2536 spin_unlock(&sci->sc_state_lock);
2537 }
2538 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2539 }
2540
2541 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2542 {
2543 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2544 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2545 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2546 return SC_FLUSH_FILE;
2547 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2548 return SC_FLUSH_DAT;
2549 }
2550 return SC_LSEG_SR;
2551 }
2552
2553 /**
2554 * nilfs_segctor_thread - main loop of the segment constructor thread.
2555 * @arg: pointer to a struct nilfs_sc_info.
2556 *
2557 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2558 * to execute segment constructions.
2559 */
2560 static int nilfs_segctor_thread(void *arg)
2561 {
2562 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2563 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
2564 int timeout = 0;
2565
2566 sci->sc_timer.data = (unsigned long)current;
2567 sci->sc_timer.function = nilfs_construction_timeout;
2568
2569 /* start sync. */
2570 sci->sc_task = current;
2571 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2572 printk(KERN_INFO
2573 "segctord starting. Construction interval = %lu seconds, "
2574 "CP frequency < %lu seconds\n",
2575 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2576
2577 spin_lock(&sci->sc_state_lock);
2578 loop:
2579 for (;;) {
2580 int mode;
2581
2582 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2583 goto end_thread;
2584
2585 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2586 mode = SC_LSEG_SR;
2587 else if (!sci->sc_flush_request)
2588 break;
2589 else
2590 mode = nilfs_segctor_flush_mode(sci);
2591
2592 spin_unlock(&sci->sc_state_lock);
2593 nilfs_segctor_thread_construct(sci, mode);
2594 spin_lock(&sci->sc_state_lock);
2595 timeout = 0;
2596 }
2597
2598
2599 if (freezing(current)) {
2600 spin_unlock(&sci->sc_state_lock);
2601 refrigerator();
2602 spin_lock(&sci->sc_state_lock);
2603 } else {
2604 DEFINE_WAIT(wait);
2605 int should_sleep = 1;
2606
2607 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2608 TASK_INTERRUPTIBLE);
2609
2610 if (sci->sc_seq_request != sci->sc_seq_done)
2611 should_sleep = 0;
2612 else if (sci->sc_flush_request)
2613 should_sleep = 0;
2614 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2615 should_sleep = time_before(jiffies,
2616 sci->sc_timer.expires);
2617
2618 if (should_sleep) {
2619 spin_unlock(&sci->sc_state_lock);
2620 schedule();
2621 spin_lock(&sci->sc_state_lock);
2622 }
2623 finish_wait(&sci->sc_wait_daemon, &wait);
2624 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2625 time_after_eq(jiffies, sci->sc_timer.expires));
2626
2627 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2628 set_nilfs_discontinued(nilfs);
2629 }
2630 goto loop;
2631
2632 end_thread:
2633 spin_unlock(&sci->sc_state_lock);
2634
2635 /* end sync. */
2636 sci->sc_task = NULL;
2637 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2638 return 0;
2639 }
2640
2641 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2642 {
2643 struct task_struct *t;
2644
2645 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2646 if (IS_ERR(t)) {
2647 int err = PTR_ERR(t);
2648
2649 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2650 err);
2651 return err;
2652 }
2653 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2654 return 0;
2655 }
2656
2657 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2658 __acquires(&sci->sc_state_lock)
2659 __releases(&sci->sc_state_lock)
2660 {
2661 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2662
2663 while (sci->sc_task) {
2664 wake_up(&sci->sc_wait_daemon);
2665 spin_unlock(&sci->sc_state_lock);
2666 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2667 spin_lock(&sci->sc_state_lock);
2668 }
2669 }
2670
2671 /*
2672 * Setup & clean-up functions
2673 */
2674 static struct nilfs_sc_info *nilfs_segctor_new(struct nilfs_sb_info *sbi,
2675 struct nilfs_root *root)
2676 {
2677 struct nilfs_sc_info *sci;
2678
2679 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2680 if (!sci)
2681 return NULL;
2682
2683 sci->sc_sbi = sbi;
2684 sci->sc_super = sbi->s_super;
2685
2686 nilfs_get_root(root);
2687 sci->sc_root = root;
2688
2689 init_waitqueue_head(&sci->sc_wait_request);
2690 init_waitqueue_head(&sci->sc_wait_daemon);
2691 init_waitqueue_head(&sci->sc_wait_task);
2692 spin_lock_init(&sci->sc_state_lock);
2693 INIT_LIST_HEAD(&sci->sc_dirty_files);
2694 INIT_LIST_HEAD(&sci->sc_segbufs);
2695 INIT_LIST_HEAD(&sci->sc_write_logs);
2696 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2697 INIT_LIST_HEAD(&sci->sc_copied_buffers);
2698 init_timer(&sci->sc_timer);
2699
2700 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2701 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2702 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2703
2704 if (sbi->s_interval)
2705 sci->sc_interval = sbi->s_interval;
2706 if (sbi->s_watermark)
2707 sci->sc_watermark = sbi->s_watermark;
2708 return sci;
2709 }
2710
2711 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2712 {
2713 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2714
2715 /* The segctord thread was stopped and its timer was removed.
2716 But some tasks remain. */
2717 do {
2718 struct nilfs_sb_info *sbi = sci->sc_sbi;
2719 struct nilfs_transaction_info ti;
2720
2721 nilfs_transaction_lock(sbi, &ti, 0);
2722 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2723 nilfs_transaction_unlock(sbi);
2724
2725 } while (ret && retrycount-- > 0);
2726 }
2727
2728 /**
2729 * nilfs_segctor_destroy - destroy the segment constructor.
2730 * @sci: nilfs_sc_info
2731 *
2732 * nilfs_segctor_destroy() kills the segctord thread and frees
2733 * the nilfs_sc_info struct.
2734 * Caller must hold the segment semaphore.
2735 */
2736 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2737 {
2738 struct nilfs_sb_info *sbi = sci->sc_sbi;
2739 int flag;
2740
2741 up_write(&sbi->s_nilfs->ns_segctor_sem);
2742
2743 spin_lock(&sci->sc_state_lock);
2744 nilfs_segctor_kill_thread(sci);
2745 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2746 || sci->sc_seq_request != sci->sc_seq_done);
2747 spin_unlock(&sci->sc_state_lock);
2748
2749 if (flag || !nilfs_segctor_confirm(sci))
2750 nilfs_segctor_write_out(sci);
2751
2752 WARN_ON(!list_empty(&sci->sc_copied_buffers));
2753
2754 if (!list_empty(&sci->sc_dirty_files)) {
2755 nilfs_warning(sbi->s_super, __func__,
2756 "dirty file(s) after the final construction\n");
2757 nilfs_dispose_list(sbi, &sci->sc_dirty_files, 1);
2758 }
2759
2760 WARN_ON(!list_empty(&sci->sc_segbufs));
2761 WARN_ON(!list_empty(&sci->sc_write_logs));
2762
2763 nilfs_put_root(sci->sc_root);
2764
2765 down_write(&sbi->s_nilfs->ns_segctor_sem);
2766
2767 del_timer_sync(&sci->sc_timer);
2768 kfree(sci);
2769 }
2770
2771 /**
2772 * nilfs_attach_segment_constructor - attach a segment constructor
2773 * @sbi: nilfs_sb_info
2774 * @root: root object of the current filesystem tree
2775 *
2776 * nilfs_attach_segment_constructor() allocates a struct nilfs_sc_info,
2777 * initializes it, and starts the segment constructor.
2778 *
2779 * Return Value: On success, 0 is returned. On error, one of the following
2780 * negative error code is returned.
2781 *
2782 * %-ENOMEM - Insufficient memory available.
2783 */
2784 int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi,
2785 struct nilfs_root *root)
2786 {
2787 int err;
2788
2789 if (NILFS_SC(sbi)) {
2790 /*
2791 * This happens if the filesystem was remounted
2792 * read/write after nilfs_error degenerated it into a
2793 * read-only mount.
2794 */
2795 nilfs_detach_segment_constructor(sbi);
2796 }
2797
2798 sbi->s_sc_info = nilfs_segctor_new(sbi, root);
2799 if (!sbi->s_sc_info)
2800 return -ENOMEM;
2801
2802 err = nilfs_segctor_start_thread(NILFS_SC(sbi));
2803 if (err) {
2804 kfree(sbi->s_sc_info);
2805 sbi->s_sc_info = NULL;
2806 }
2807 return err;
2808 }
2809
2810 /**
2811 * nilfs_detach_segment_constructor - destroy the segment constructor
2812 * @sbi: nilfs_sb_info
2813 *
2814 * nilfs_detach_segment_constructor() kills the segment constructor daemon,
2815 * frees the struct nilfs_sc_info, and destroy the dirty file list.
2816 */
2817 void nilfs_detach_segment_constructor(struct nilfs_sb_info *sbi)
2818 {
2819 struct the_nilfs *nilfs = sbi->s_nilfs;
2820 LIST_HEAD(garbage_list);
2821
2822 down_write(&nilfs->ns_segctor_sem);
2823 if (NILFS_SC(sbi)) {
2824 nilfs_segctor_destroy(NILFS_SC(sbi));
2825 sbi->s_sc_info = NULL;
2826 }
2827
2828 /* Force to free the list of dirty files */
2829 spin_lock(&sbi->s_inode_lock);
2830 if (!list_empty(&sbi->s_dirty_files)) {
2831 list_splice_init(&sbi->s_dirty_files, &garbage_list);
2832 nilfs_warning(sbi->s_super, __func__,
2833 "Non empty dirty list after the last "
2834 "segment construction\n");
2835 }
2836 spin_unlock(&sbi->s_inode_lock);
2837 up_write(&nilfs->ns_segctor_sem);
2838
2839 nilfs_dispose_list(sbi, &garbage_list, 1);
2840 }