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IPVS: fix netns if reading ip_vs_* procfs entries
[linux-2.6/linux-mips.git] / fs / nilfs2 / segment.c
blobafe4f2183454d49a4be19b902c200b1922ebcc4e
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 the_nilfs *, struct list_head *, int);
108
109 #define nilfs_cnt32_gt(a, b) \
110 (typecheck(__u32, a) && typecheck(__u32, b) && \
111 ((__s32)(b) - (__s32)(a) < 0))
112 #define nilfs_cnt32_ge(a, b) \
113 (typecheck(__u32, a) && typecheck(__u32, b) && \
114 ((__s32)(a) - (__s32)(b) >= 0))
115 #define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a)
116 #define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a)
117
118 static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
119 {
120 struct nilfs_transaction_info *cur_ti = current->journal_info;
121 void *save = NULL;
122
123 if (cur_ti) {
124 if (cur_ti->ti_magic == NILFS_TI_MAGIC)
125 return ++cur_ti->ti_count;
126 else {
127 /*
128 * If journal_info field is occupied by other FS,
129 * it is saved and will be restored on
130 * nilfs_transaction_commit().
131 */
132 printk(KERN_WARNING
133 "NILFS warning: journal info from a different "
134 "FS\n");
135 save = current->journal_info;
136 }
137 }
138 if (!ti) {
139 ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
140 if (!ti)
141 return -ENOMEM;
142 ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
143 } else {
144 ti->ti_flags = 0;
145 }
146 ti->ti_count = 0;
147 ti->ti_save = save;
148 ti->ti_magic = NILFS_TI_MAGIC;
149 current->journal_info = ti;
150 return 0;
151 }
152
153 /**
154 * nilfs_transaction_begin - start indivisible file operations.
155 * @sb: super block
156 * @ti: nilfs_transaction_info
157 * @vacancy_check: flags for vacancy rate checks
158 *
159 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
160 * the segment semaphore, to make a segment construction and write tasks
161 * exclusive. The function is used with nilfs_transaction_commit() in pairs.
162 * The region enclosed by these two functions can be nested. To avoid a
163 * deadlock, the semaphore is only acquired or released in the outermost call.
164 *
165 * This function allocates a nilfs_transaction_info struct to keep context
166 * information on it. It is initialized and hooked onto the current task in
167 * the outermost call. If a pre-allocated struct is given to @ti, it is used
168 * instead; otherwise a new struct is assigned from a slab.
169 *
170 * When @vacancy_check flag is set, this function will check the amount of
171 * free space, and will wait for the GC to reclaim disk space if low capacity.
172 *
173 * Return Value: On success, 0 is returned. On error, one of the following
174 * negative error code is returned.
175 *
176 * %-ENOMEM - Insufficient memory available.
177 *
178 * %-ENOSPC - No space left on device
179 */
180 int nilfs_transaction_begin(struct super_block *sb,
181 struct nilfs_transaction_info *ti,
182 int vacancy_check)
183 {
184 struct the_nilfs *nilfs;
185 int ret = nilfs_prepare_segment_lock(ti);
186
187 if (unlikely(ret < 0))
188 return ret;
189 if (ret > 0)
190 return 0;
191
192 vfs_check_frozen(sb, SB_FREEZE_WRITE);
193
194 nilfs = sb->s_fs_info;
195 down_read(&nilfs->ns_segctor_sem);
196 if (vacancy_check && nilfs_near_disk_full(nilfs)) {
197 up_read(&nilfs->ns_segctor_sem);
198 ret = -ENOSPC;
199 goto failed;
200 }
201 return 0;
202
203 failed:
204 ti = current->journal_info;
205 current->journal_info = ti->ti_save;
206 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
207 kmem_cache_free(nilfs_transaction_cachep, ti);
208 return ret;
209 }
210
211 /**
212 * nilfs_transaction_commit - commit indivisible file operations.
213 * @sb: super block
214 *
215 * nilfs_transaction_commit() releases the read semaphore which is
216 * acquired by nilfs_transaction_begin(). This is only performed
217 * in outermost call of this function. If a commit flag is set,
218 * nilfs_transaction_commit() sets a timer to start the segment
219 * constructor. If a sync flag is set, it starts construction
220 * directly.
221 */
222 int nilfs_transaction_commit(struct super_block *sb)
223 {
224 struct nilfs_transaction_info *ti = current->journal_info;
225 struct the_nilfs *nilfs = sb->s_fs_info;
226 int err = 0;
227
228 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
229 ti->ti_flags |= NILFS_TI_COMMIT;
230 if (ti->ti_count > 0) {
231 ti->ti_count--;
232 return 0;
233 }
234 if (nilfs->ns_writer) {
235 struct nilfs_sc_info *sci = nilfs->ns_writer;
236
237 if (ti->ti_flags & NILFS_TI_COMMIT)
238 nilfs_segctor_start_timer(sci);
239 if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark)
240 nilfs_segctor_do_flush(sci, 0);
241 }
242 up_read(&nilfs->ns_segctor_sem);
243 current->journal_info = ti->ti_save;
244
245 if (ti->ti_flags & NILFS_TI_SYNC)
246 err = nilfs_construct_segment(sb);
247 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
248 kmem_cache_free(nilfs_transaction_cachep, ti);
249 return err;
250 }
251
252 void nilfs_transaction_abort(struct super_block *sb)
253 {
254 struct nilfs_transaction_info *ti = current->journal_info;
255 struct the_nilfs *nilfs = sb->s_fs_info;
256
257 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
258 if (ti->ti_count > 0) {
259 ti->ti_count--;
260 return;
261 }
262 up_read(&nilfs->ns_segctor_sem);
263
264 current->journal_info = ti->ti_save;
265 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
266 kmem_cache_free(nilfs_transaction_cachep, ti);
267 }
268
269 void nilfs_relax_pressure_in_lock(struct super_block *sb)
270 {
271 struct the_nilfs *nilfs = sb->s_fs_info;
272 struct nilfs_sc_info *sci = nilfs->ns_writer;
273
274 if (!sci || !sci->sc_flush_request)
275 return;
276
277 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
278 up_read(&nilfs->ns_segctor_sem);
279
280 down_write(&nilfs->ns_segctor_sem);
281 if (sci->sc_flush_request &&
282 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
283 struct nilfs_transaction_info *ti = current->journal_info;
284
285 ti->ti_flags |= NILFS_TI_WRITER;
286 nilfs_segctor_do_immediate_flush(sci);
287 ti->ti_flags &= ~NILFS_TI_WRITER;
288 }
289 downgrade_write(&nilfs->ns_segctor_sem);
290 }
291
292 static void nilfs_transaction_lock(struct super_block *sb,
293 struct nilfs_transaction_info *ti,
294 int gcflag)
295 {
296 struct nilfs_transaction_info *cur_ti = current->journal_info;
297 struct the_nilfs *nilfs = sb->s_fs_info;
298 struct nilfs_sc_info *sci = nilfs->ns_writer;
299
300 WARN_ON(cur_ti);
301 ti->ti_flags = NILFS_TI_WRITER;
302 ti->ti_count = 0;
303 ti->ti_save = cur_ti;
304 ti->ti_magic = NILFS_TI_MAGIC;
305 INIT_LIST_HEAD(&ti->ti_garbage);
306 current->journal_info = ti;
307
308 for (;;) {
309 down_write(&nilfs->ns_segctor_sem);
310 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags))
311 break;
312
313 nilfs_segctor_do_immediate_flush(sci);
314
315 up_write(&nilfs->ns_segctor_sem);
316 yield();
317 }
318 if (gcflag)
319 ti->ti_flags |= NILFS_TI_GC;
320 }
321
322 static void nilfs_transaction_unlock(struct super_block *sb)
323 {
324 struct nilfs_transaction_info *ti = current->journal_info;
325 struct the_nilfs *nilfs = sb->s_fs_info;
326
327 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
328 BUG_ON(ti->ti_count > 0);
329
330 up_write(&nilfs->ns_segctor_sem);
331 current->journal_info = ti->ti_save;
332 if (!list_empty(&ti->ti_garbage))
333 nilfs_dispose_list(nilfs, &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, sci->sc_cno);
370 if (unlikely(err))
371 return err;
372
373 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
374 sumbytes = segbuf->sb_sum.sumbytes;
375 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
376 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
377 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
378 return 0;
379 }
380
381 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
382 {
383 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
384 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
385 return -E2BIG; /* The current segment is filled up
386 (internal code) */
387 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
388 return nilfs_segctor_reset_segment_buffer(sci);
389 }
390
391 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
392 {
393 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
394 int err;
395
396 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
397 err = nilfs_segctor_feed_segment(sci);
398 if (err)
399 return err;
400 segbuf = sci->sc_curseg;
401 }
402 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root);
403 if (likely(!err))
404 segbuf->sb_sum.flags |= NILFS_SS_SR;
405 return err;
406 }
407
408 /*
409 * Functions for making segment summary and payloads
410 */
411 static int nilfs_segctor_segsum_block_required(
412 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
413 unsigned binfo_size)
414 {
415 unsigned blocksize = sci->sc_super->s_blocksize;
416 /* Size of finfo and binfo is enough small against blocksize */
417
418 return ssp->offset + binfo_size +
419 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
420 blocksize;
421 }
422
423 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
424 struct inode *inode)
425 {
426 sci->sc_curseg->sb_sum.nfinfo++;
427 sci->sc_binfo_ptr = sci->sc_finfo_ptr;
428 nilfs_segctor_map_segsum_entry(
429 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
430
431 if (NILFS_I(inode)->i_root &&
432 !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 __u64 cno;
444
445 if (sci->sc_blk_cnt == 0)
446 return;
447
448 ii = NILFS_I(inode);
449
450 if (test_bit(NILFS_I_GCINODE, &ii->i_state))
451 cno = ii->i_cno;
452 else if (NILFS_ROOT_METADATA_FILE(inode->i_ino))
453 cno = 0;
454 else
455 cno = sci->sc_cno;
456
457 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
458 sizeof(*finfo));
459 finfo->fi_ino = cpu_to_le64(inode->i_ino);
460 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
461 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
462 finfo->fi_cno = cpu_to_le64(cno);
463
464 segbuf = sci->sc_curseg;
465 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
466 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
467 sci->sc_finfo_ptr = sci->sc_binfo_ptr;
468 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
469 }
470
471 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
472 struct buffer_head *bh,
473 struct inode *inode,
474 unsigned binfo_size)
475 {
476 struct nilfs_segment_buffer *segbuf;
477 int required, err = 0;
478
479 retry:
480 segbuf = sci->sc_curseg;
481 required = nilfs_segctor_segsum_block_required(
482 sci, &sci->sc_binfo_ptr, binfo_size);
483 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
484 nilfs_segctor_end_finfo(sci, inode);
485 err = nilfs_segctor_feed_segment(sci);
486 if (err)
487 return err;
488 goto retry;
489 }
490 if (unlikely(required)) {
491 err = nilfs_segbuf_extend_segsum(segbuf);
492 if (unlikely(err))
493 goto failed;
494 }
495 if (sci->sc_blk_cnt == 0)
496 nilfs_segctor_begin_finfo(sci, inode);
497
498 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
499 /* Substitution to vblocknr is delayed until update_blocknr() */
500 nilfs_segbuf_add_file_buffer(segbuf, bh);
501 sci->sc_blk_cnt++;
502 failed:
503 return err;
504 }
505
506 /*
507 * Callback functions that enumerate, mark, and collect dirty blocks
508 */
509 static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
510 struct buffer_head *bh, struct inode *inode)
511 {
512 int err;
513
514 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
515 if (err < 0)
516 return err;
517
518 err = nilfs_segctor_add_file_block(sci, bh, inode,
519 sizeof(struct nilfs_binfo_v));
520 if (!err)
521 sci->sc_datablk_cnt++;
522 return err;
523 }
524
525 static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
526 struct buffer_head *bh,
527 struct inode *inode)
528 {
529 return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
530 }
531
532 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
533 struct buffer_head *bh,
534 struct inode *inode)
535 {
536 WARN_ON(!buffer_dirty(bh));
537 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
538 }
539
540 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
541 struct nilfs_segsum_pointer *ssp,
542 union nilfs_binfo *binfo)
543 {
544 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
545 sci, ssp, sizeof(*binfo_v));
546 *binfo_v = binfo->bi_v;
547 }
548
549 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
550 struct nilfs_segsum_pointer *ssp,
551 union nilfs_binfo *binfo)
552 {
553 __le64 *vblocknr = nilfs_segctor_map_segsum_entry(
554 sci, ssp, sizeof(*vblocknr));
555 *vblocknr = binfo->bi_v.bi_vblocknr;
556 }
557
558 static struct nilfs_sc_operations nilfs_sc_file_ops = {
559 .collect_data = nilfs_collect_file_data,
560 .collect_node = nilfs_collect_file_node,
561 .collect_bmap = nilfs_collect_file_bmap,
562 .write_data_binfo = nilfs_write_file_data_binfo,
563 .write_node_binfo = nilfs_write_file_node_binfo,
564 };
565
566 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
567 struct buffer_head *bh, struct inode *inode)
568 {
569 int err;
570
571 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
572 if (err < 0)
573 return err;
574
575 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
576 if (!err)
577 sci->sc_datablk_cnt++;
578 return err;
579 }
580
581 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
582 struct buffer_head *bh, struct inode *inode)
583 {
584 WARN_ON(!buffer_dirty(bh));
585 return nilfs_segctor_add_file_block(sci, bh, inode,
586 sizeof(struct nilfs_binfo_dat));
587 }
588
589 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
590 struct nilfs_segsum_pointer *ssp,
591 union nilfs_binfo *binfo)
592 {
593 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
594 sizeof(*blkoff));
595 *blkoff = binfo->bi_dat.bi_blkoff;
596 }
597
598 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
599 struct nilfs_segsum_pointer *ssp,
600 union nilfs_binfo *binfo)
601 {
602 struct nilfs_binfo_dat *binfo_dat =
603 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
604 *binfo_dat = binfo->bi_dat;
605 }
606
607 static struct nilfs_sc_operations nilfs_sc_dat_ops = {
608 .collect_data = nilfs_collect_dat_data,
609 .collect_node = nilfs_collect_file_node,
610 .collect_bmap = nilfs_collect_dat_bmap,
611 .write_data_binfo = nilfs_write_dat_data_binfo,
612 .write_node_binfo = nilfs_write_dat_node_binfo,
613 };
614
615 static struct nilfs_sc_operations nilfs_sc_dsync_ops = {
616 .collect_data = nilfs_collect_file_data,
617 .collect_node = NULL,
618 .collect_bmap = NULL,
619 .write_data_binfo = nilfs_write_file_data_binfo,
620 .write_node_binfo = NULL,
621 };
622
623 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
624 struct list_head *listp,
625 size_t nlimit,
626 loff_t start, loff_t end)
627 {
628 struct address_space *mapping = inode->i_mapping;
629 struct pagevec pvec;
630 pgoff_t index = 0, last = ULONG_MAX;
631 size_t ndirties = 0;
632 int i;
633
634 if (unlikely(start != 0 || end != LLONG_MAX)) {
635 /*
636 * A valid range is given for sync-ing data pages. The
637 * range is rounded to per-page; extra dirty buffers
638 * may be included if blocksize < pagesize.
639 */
640 index = start >> PAGE_SHIFT;
641 last = end >> PAGE_SHIFT;
642 }
643 pagevec_init(&pvec, 0);
644 repeat:
645 if (unlikely(index > last) ||
646 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
647 min_t(pgoff_t, last - index,
648 PAGEVEC_SIZE - 1) + 1))
649 return ndirties;
650
651 for (i = 0; i < pagevec_count(&pvec); i++) {
652 struct buffer_head *bh, *head;
653 struct page *page = pvec.pages[i];
654
655 if (unlikely(page->index > last))
656 break;
657
658 if (mapping->host) {
659 lock_page(page);
660 if (!page_has_buffers(page))
661 create_empty_buffers(page,
662 1 << inode->i_blkbits, 0);
663 unlock_page(page);
664 }
665
666 bh = head = page_buffers(page);
667 do {
668 if (!buffer_dirty(bh))
669 continue;
670 get_bh(bh);
671 list_add_tail(&bh->b_assoc_buffers, listp);
672 ndirties++;
673 if (unlikely(ndirties >= nlimit)) {
674 pagevec_release(&pvec);
675 cond_resched();
676 return ndirties;
677 }
678 } while (bh = bh->b_this_page, bh != head);
679 }
680 pagevec_release(&pvec);
681 cond_resched();
682 goto repeat;
683 }
684
685 static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
686 struct list_head *listp)
687 {
688 struct nilfs_inode_info *ii = NILFS_I(inode);
689 struct address_space *mapping = &ii->i_btnode_cache;
690 struct pagevec pvec;
691 struct buffer_head *bh, *head;
692 unsigned int i;
693 pgoff_t index = 0;
694
695 pagevec_init(&pvec, 0);
696
697 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
698 PAGEVEC_SIZE)) {
699 for (i = 0; i < pagevec_count(&pvec); i++) {
700 bh = head = page_buffers(pvec.pages[i]);
701 do {
702 if (buffer_dirty(bh)) {
703 get_bh(bh);
704 list_add_tail(&bh->b_assoc_buffers,
705 listp);
706 }
707 bh = bh->b_this_page;
708 } while (bh != head);
709 }
710 pagevec_release(&pvec);
711 cond_resched();
712 }
713 }
714
715 static void nilfs_dispose_list(struct the_nilfs *nilfs,
716 struct list_head *head, int force)
717 {
718 struct nilfs_inode_info *ii, *n;
719 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
720 unsigned nv = 0;
721
722 while (!list_empty(head)) {
723 spin_lock(&nilfs->ns_inode_lock);
724 list_for_each_entry_safe(ii, n, head, i_dirty) {
725 list_del_init(&ii->i_dirty);
726 if (force) {
727 if (unlikely(ii->i_bh)) {
728 brelse(ii->i_bh);
729 ii->i_bh = NULL;
730 }
731 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
732 set_bit(NILFS_I_QUEUED, &ii->i_state);
733 list_add_tail(&ii->i_dirty,
734 &nilfs->ns_dirty_files);
735 continue;
736 }
737 ivec[nv++] = ii;
738 if (nv == SC_N_INODEVEC)
739 break;
740 }
741 spin_unlock(&nilfs->ns_inode_lock);
742
743 for (pii = ivec; nv > 0; pii++, nv--)
744 iput(&(*pii)->vfs_inode);
745 }
746 }
747
748 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
749 struct nilfs_root *root)
750 {
751 int ret = 0;
752
753 if (nilfs_mdt_fetch_dirty(root->ifile))
754 ret++;
755 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
756 ret++;
757 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
758 ret++;
759 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat))
760 ret++;
761 return ret;
762 }
763
764 static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
765 {
766 return list_empty(&sci->sc_dirty_files) &&
767 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
768 sci->sc_nfreesegs == 0 &&
769 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
770 }
771
772 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
773 {
774 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
775 int ret = 0;
776
777 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
778 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
779
780 spin_lock(&nilfs->ns_inode_lock);
781 if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci))
782 ret++;
783
784 spin_unlock(&nilfs->ns_inode_lock);
785 return ret;
786 }
787
788 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
789 {
790 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
791
792 nilfs_mdt_clear_dirty(sci->sc_root->ifile);
793 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
794 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
795 nilfs_mdt_clear_dirty(nilfs->ns_dat);
796 }
797
798 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
799 {
800 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
801 struct buffer_head *bh_cp;
802 struct nilfs_checkpoint *raw_cp;
803 int err;
804
805 /* XXX: this interface will be changed */
806 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
807 &raw_cp, &bh_cp);
808 if (likely(!err)) {
809 /* The following code is duplicated with cpfile. But, it is
810 needed to collect the checkpoint even if it was not newly
811 created */
812 nilfs_mdt_mark_buffer_dirty(bh_cp);
813 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
814 nilfs_cpfile_put_checkpoint(
815 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
816 } else
817 WARN_ON(err == -EINVAL || err == -ENOENT);
818
819 return err;
820 }
821
822 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
823 {
824 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
825 struct buffer_head *bh_cp;
826 struct nilfs_checkpoint *raw_cp;
827 int err;
828
829 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
830 &raw_cp, &bh_cp);
831 if (unlikely(err)) {
832 WARN_ON(err == -EINVAL || err == -ENOENT);
833 goto failed_ibh;
834 }
835 raw_cp->cp_snapshot_list.ssl_next = 0;
836 raw_cp->cp_snapshot_list.ssl_prev = 0;
837 raw_cp->cp_inodes_count =
838 cpu_to_le64(atomic_read(&sci->sc_root->inodes_count));
839 raw_cp->cp_blocks_count =
840 cpu_to_le64(atomic_read(&sci->sc_root->blocks_count));
841 raw_cp->cp_nblk_inc =
842 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
843 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
844 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
845
846 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
847 nilfs_checkpoint_clear_minor(raw_cp);
848 else
849 nilfs_checkpoint_set_minor(raw_cp);
850
851 nilfs_write_inode_common(sci->sc_root->ifile,
852 &raw_cp->cp_ifile_inode, 1);
853 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
854 return 0;
855
856 failed_ibh:
857 return err;
858 }
859
860 static void nilfs_fill_in_file_bmap(struct inode *ifile,
861 struct nilfs_inode_info *ii)
862
863 {
864 struct buffer_head *ibh;
865 struct nilfs_inode *raw_inode;
866
867 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
868 ibh = ii->i_bh;
869 BUG_ON(!ibh);
870 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
871 ibh);
872 nilfs_bmap_write(ii->i_bmap, raw_inode);
873 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
874 }
875 }
876
877 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
878 {
879 struct nilfs_inode_info *ii;
880
881 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
882 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
883 set_bit(NILFS_I_COLLECTED, &ii->i_state);
884 }
885 }
886
887 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
888 struct the_nilfs *nilfs)
889 {
890 struct buffer_head *bh_sr;
891 struct nilfs_super_root *raw_sr;
892 unsigned isz = nilfs->ns_inode_size;
893
894 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
895 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
896
897 raw_sr->sr_bytes = cpu_to_le16(NILFS_SR_BYTES);
898 raw_sr->sr_nongc_ctime
899 = cpu_to_le64(nilfs_doing_gc() ?
900 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
901 raw_sr->sr_flags = 0;
902
903 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr +
904 NILFS_SR_DAT_OFFSET(isz), 1);
905 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
906 NILFS_SR_CPFILE_OFFSET(isz), 1);
907 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
908 NILFS_SR_SUFILE_OFFSET(isz), 1);
909 }
910
911 static void nilfs_redirty_inodes(struct list_head *head)
912 {
913 struct nilfs_inode_info *ii;
914
915 list_for_each_entry(ii, head, i_dirty) {
916 if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
917 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
918 }
919 }
920
921 static void nilfs_drop_collected_inodes(struct list_head *head)
922 {
923 struct nilfs_inode_info *ii;
924
925 list_for_each_entry(ii, head, i_dirty) {
926 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
927 continue;
928
929 clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
930 set_bit(NILFS_I_UPDATED, &ii->i_state);
931 }
932 }
933
934 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
935 struct inode *inode,
936 struct list_head *listp,
937 int (*collect)(struct nilfs_sc_info *,
938 struct buffer_head *,
939 struct inode *))
940 {
941 struct buffer_head *bh, *n;
942 int err = 0;
943
944 if (collect) {
945 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
946 list_del_init(&bh->b_assoc_buffers);
947 err = collect(sci, bh, inode);
948 brelse(bh);
949 if (unlikely(err))
950 goto dispose_buffers;
951 }
952 return 0;
953 }
954
955 dispose_buffers:
956 while (!list_empty(listp)) {
957 bh = list_entry(listp->next, struct buffer_head,
958 b_assoc_buffers);
959 list_del_init(&bh->b_assoc_buffers);
960 brelse(bh);
961 }
962 return err;
963 }
964
965 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
966 {
967 /* Remaining number of blocks within segment buffer */
968 return sci->sc_segbuf_nblocks -
969 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
970 }
971
972 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
973 struct inode *inode,
974 struct nilfs_sc_operations *sc_ops)
975 {
976 LIST_HEAD(data_buffers);
977 LIST_HEAD(node_buffers);
978 int err;
979
980 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
981 size_t n, rest = nilfs_segctor_buffer_rest(sci);
982
983 n = nilfs_lookup_dirty_data_buffers(
984 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
985 if (n > rest) {
986 err = nilfs_segctor_apply_buffers(
987 sci, inode, &data_buffers,
988 sc_ops->collect_data);
989 BUG_ON(!err); /* always receive -E2BIG or true error */
990 goto break_or_fail;
991 }
992 }
993 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
994
995 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
996 err = nilfs_segctor_apply_buffers(
997 sci, inode, &data_buffers, sc_ops->collect_data);
998 if (unlikely(err)) {
999 /* dispose node list */
1000 nilfs_segctor_apply_buffers(
1001 sci, inode, &node_buffers, NULL);
1002 goto break_or_fail;
1003 }
1004 sci->sc_stage.flags |= NILFS_CF_NODE;
1005 }
1006 /* Collect node */
1007 err = nilfs_segctor_apply_buffers(
1008 sci, inode, &node_buffers, sc_ops->collect_node);
1009 if (unlikely(err))
1010 goto break_or_fail;
1011
1012 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1013 err = nilfs_segctor_apply_buffers(
1014 sci, inode, &node_buffers, sc_ops->collect_bmap);
1015 if (unlikely(err))
1016 goto break_or_fail;
1017
1018 nilfs_segctor_end_finfo(sci, inode);
1019 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1020
1021 break_or_fail:
1022 return err;
1023 }
1024
1025 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1026 struct inode *inode)
1027 {
1028 LIST_HEAD(data_buffers);
1029 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1030 int err;
1031
1032 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1033 sci->sc_dsync_start,
1034 sci->sc_dsync_end);
1035
1036 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1037 nilfs_collect_file_data);
1038 if (!err) {
1039 nilfs_segctor_end_finfo(sci, inode);
1040 BUG_ON(n > rest);
1041 /* always receive -E2BIG or true error if n > rest */
1042 }
1043 return err;
1044 }
1045
1046 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1047 {
1048 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1049 struct list_head *head;
1050 struct nilfs_inode_info *ii;
1051 size_t ndone;
1052 int err = 0;
1053
1054 switch (sci->sc_stage.scnt) {
1055 case NILFS_ST_INIT:
1056 /* Pre-processes */
1057 sci->sc_stage.flags = 0;
1058
1059 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1060 sci->sc_nblk_inc = 0;
1061 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1062 if (mode == SC_LSEG_DSYNC) {
1063 sci->sc_stage.scnt = NILFS_ST_DSYNC;
1064 goto dsync_mode;
1065 }
1066 }
1067
1068 sci->sc_stage.dirty_file_ptr = NULL;
1069 sci->sc_stage.gc_inode_ptr = NULL;
1070 if (mode == SC_FLUSH_DAT) {
1071 sci->sc_stage.scnt = NILFS_ST_DAT;
1072 goto dat_stage;
1073 }
1074 sci->sc_stage.scnt++; /* Fall through */
1075 case NILFS_ST_GC:
1076 if (nilfs_doing_gc()) {
1077 head = &sci->sc_gc_inodes;
1078 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1079 head, i_dirty);
1080 list_for_each_entry_continue(ii, head, i_dirty) {
1081 err = nilfs_segctor_scan_file(
1082 sci, &ii->vfs_inode,
1083 &nilfs_sc_file_ops);
1084 if (unlikely(err)) {
1085 sci->sc_stage.gc_inode_ptr = list_entry(
1086 ii->i_dirty.prev,
1087 struct nilfs_inode_info,
1088 i_dirty);
1089 goto break_or_fail;
1090 }
1091 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1092 }
1093 sci->sc_stage.gc_inode_ptr = NULL;
1094 }
1095 sci->sc_stage.scnt++; /* Fall through */
1096 case NILFS_ST_FILE:
1097 head = &sci->sc_dirty_files;
1098 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1099 i_dirty);
1100 list_for_each_entry_continue(ii, head, i_dirty) {
1101 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1102
1103 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1104 &nilfs_sc_file_ops);
1105 if (unlikely(err)) {
1106 sci->sc_stage.dirty_file_ptr =
1107 list_entry(ii->i_dirty.prev,
1108 struct nilfs_inode_info,
1109 i_dirty);
1110 goto break_or_fail;
1111 }
1112 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1113 /* XXX: required ? */
1114 }
1115 sci->sc_stage.dirty_file_ptr = NULL;
1116 if (mode == SC_FLUSH_FILE) {
1117 sci->sc_stage.scnt = NILFS_ST_DONE;
1118 return 0;
1119 }
1120 sci->sc_stage.scnt++;
1121 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1122 /* Fall through */
1123 case NILFS_ST_IFILE:
1124 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile,
1125 &nilfs_sc_file_ops);
1126 if (unlikely(err))
1127 break;
1128 sci->sc_stage.scnt++;
1129 /* Creating a checkpoint */
1130 err = nilfs_segctor_create_checkpoint(sci);
1131 if (unlikely(err))
1132 break;
1133 /* Fall through */
1134 case NILFS_ST_CPFILE:
1135 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1136 &nilfs_sc_file_ops);
1137 if (unlikely(err))
1138 break;
1139 sci->sc_stage.scnt++; /* Fall through */
1140 case NILFS_ST_SUFILE:
1141 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1142 sci->sc_nfreesegs, &ndone);
1143 if (unlikely(err)) {
1144 nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1145 sci->sc_freesegs, ndone,
1146 NULL);
1147 break;
1148 }
1149 sci->sc_stage.flags |= NILFS_CF_SUFREED;
1150
1151 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1152 &nilfs_sc_file_ops);
1153 if (unlikely(err))
1154 break;
1155 sci->sc_stage.scnt++; /* Fall through */
1156 case NILFS_ST_DAT:
1157 dat_stage:
1158 err = nilfs_segctor_scan_file(sci, nilfs->ns_dat,
1159 &nilfs_sc_dat_ops);
1160 if (unlikely(err))
1161 break;
1162 if (mode == SC_FLUSH_DAT) {
1163 sci->sc_stage.scnt = NILFS_ST_DONE;
1164 return 0;
1165 }
1166 sci->sc_stage.scnt++; /* Fall through */
1167 case NILFS_ST_SR:
1168 if (mode == SC_LSEG_SR) {
1169 /* Appending a super root */
1170 err = nilfs_segctor_add_super_root(sci);
1171 if (unlikely(err))
1172 break;
1173 }
1174 /* End of a logical segment */
1175 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1176 sci->sc_stage.scnt = NILFS_ST_DONE;
1177 return 0;
1178 case NILFS_ST_DSYNC:
1179 dsync_mode:
1180 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1181 ii = sci->sc_dsync_inode;
1182 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1183 break;
1184
1185 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1186 if (unlikely(err))
1187 break;
1188 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1189 sci->sc_stage.scnt = NILFS_ST_DONE;
1190 return 0;
1191 case NILFS_ST_DONE:
1192 return 0;
1193 default:
1194 BUG();
1195 }
1196
1197 break_or_fail:
1198 return err;
1199 }
1200
1201 /**
1202 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1203 * @sci: nilfs_sc_info
1204 * @nilfs: nilfs object
1205 */
1206 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1207 struct the_nilfs *nilfs)
1208 {
1209 struct nilfs_segment_buffer *segbuf, *prev;
1210 __u64 nextnum;
1211 int err, alloc = 0;
1212
1213 segbuf = nilfs_segbuf_new(sci->sc_super);
1214 if (unlikely(!segbuf))
1215 return -ENOMEM;
1216
1217 if (list_empty(&sci->sc_write_logs)) {
1218 nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1219 nilfs->ns_pseg_offset, nilfs);
1220 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1221 nilfs_shift_to_next_segment(nilfs);
1222 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1223 }
1224
1225 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1226 nextnum = nilfs->ns_nextnum;
1227
1228 if (nilfs->ns_segnum == nilfs->ns_nextnum)
1229 /* Start from the head of a new full segment */
1230 alloc++;
1231 } else {
1232 /* Continue logs */
1233 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1234 nilfs_segbuf_map_cont(segbuf, prev);
1235 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1236 nextnum = prev->sb_nextnum;
1237
1238 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1239 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1240 segbuf->sb_sum.seg_seq++;
1241 alloc++;
1242 }
1243 }
1244
1245 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1246 if (err)
1247 goto failed;
1248
1249 if (alloc) {
1250 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1251 if (err)
1252 goto failed;
1253 }
1254 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1255
1256 BUG_ON(!list_empty(&sci->sc_segbufs));
1257 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1258 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1259 return 0;
1260
1261 failed:
1262 nilfs_segbuf_free(segbuf);
1263 return err;
1264 }
1265
1266 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1267 struct the_nilfs *nilfs, int nadd)
1268 {
1269 struct nilfs_segment_buffer *segbuf, *prev;
1270 struct inode *sufile = nilfs->ns_sufile;
1271 __u64 nextnextnum;
1272 LIST_HEAD(list);
1273 int err, ret, i;
1274
1275 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1276 /*
1277 * Since the segment specified with nextnum might be allocated during
1278 * the previous construction, the buffer including its segusage may
1279 * not be dirty. The following call ensures that the buffer is dirty
1280 * and will pin the buffer on memory until the sufile is written.
1281 */
1282 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1283 if (unlikely(err))
1284 return err;
1285
1286 for (i = 0; i < nadd; i++) {
1287 /* extend segment info */
1288 err = -ENOMEM;
1289 segbuf = nilfs_segbuf_new(sci->sc_super);
1290 if (unlikely(!segbuf))
1291 goto failed;
1292
1293 /* map this buffer to region of segment on-disk */
1294 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1295 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1296
1297 /* allocate the next next full segment */
1298 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1299 if (unlikely(err))
1300 goto failed_segbuf;
1301
1302 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1303 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1304
1305 list_add_tail(&segbuf->sb_list, &list);
1306 prev = segbuf;
1307 }
1308 list_splice_tail(&list, &sci->sc_segbufs);
1309 return 0;
1310
1311 failed_segbuf:
1312 nilfs_segbuf_free(segbuf);
1313 failed:
1314 list_for_each_entry(segbuf, &list, sb_list) {
1315 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1316 WARN_ON(ret); /* never fails */
1317 }
1318 nilfs_destroy_logs(&list);
1319 return err;
1320 }
1321
1322 static void nilfs_free_incomplete_logs(struct list_head *logs,
1323 struct the_nilfs *nilfs)
1324 {
1325 struct nilfs_segment_buffer *segbuf, *prev;
1326 struct inode *sufile = nilfs->ns_sufile;
1327 int ret;
1328
1329 segbuf = NILFS_FIRST_SEGBUF(logs);
1330 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1331 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1332 WARN_ON(ret); /* never fails */
1333 }
1334 if (atomic_read(&segbuf->sb_err)) {
1335 /* Case 1: The first segment failed */
1336 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1337 /* Case 1a: Partial segment appended into an existing
1338 segment */
1339 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1340 segbuf->sb_fseg_end);
1341 else /* Case 1b: New full segment */
1342 set_nilfs_discontinued(nilfs);
1343 }
1344
1345 prev = segbuf;
1346 list_for_each_entry_continue(segbuf, logs, sb_list) {
1347 if (prev->sb_nextnum != segbuf->sb_nextnum) {
1348 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1349 WARN_ON(ret); /* never fails */
1350 }
1351 if (atomic_read(&segbuf->sb_err) &&
1352 segbuf->sb_segnum != nilfs->ns_nextnum)
1353 /* Case 2: extended segment (!= next) failed */
1354 nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1355 prev = segbuf;
1356 }
1357 }
1358
1359 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1360 struct inode *sufile)
1361 {
1362 struct nilfs_segment_buffer *segbuf;
1363 unsigned long live_blocks;
1364 int ret;
1365
1366 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1367 live_blocks = segbuf->sb_sum.nblocks +
1368 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1369 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1370 live_blocks,
1371 sci->sc_seg_ctime);
1372 WARN_ON(ret); /* always succeed because the segusage is dirty */
1373 }
1374 }
1375
1376 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1377 {
1378 struct nilfs_segment_buffer *segbuf;
1379 int ret;
1380
1381 segbuf = NILFS_FIRST_SEGBUF(logs);
1382 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1383 segbuf->sb_pseg_start -
1384 segbuf->sb_fseg_start, 0);
1385 WARN_ON(ret); /* always succeed because the segusage is dirty */
1386
1387 list_for_each_entry_continue(segbuf, logs, sb_list) {
1388 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1389 0, 0);
1390 WARN_ON(ret); /* always succeed */
1391 }
1392 }
1393
1394 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1395 struct nilfs_segment_buffer *last,
1396 struct inode *sufile)
1397 {
1398 struct nilfs_segment_buffer *segbuf = last;
1399 int ret;
1400
1401 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1402 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1403 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1404 WARN_ON(ret);
1405 }
1406 nilfs_truncate_logs(&sci->sc_segbufs, last);
1407 }
1408
1409
1410 static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1411 struct the_nilfs *nilfs, int mode)
1412 {
1413 struct nilfs_cstage prev_stage = sci->sc_stage;
1414 int err, nadd = 1;
1415
1416 /* Collection retry loop */
1417 for (;;) {
1418 sci->sc_nblk_this_inc = 0;
1419 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1420
1421 err = nilfs_segctor_reset_segment_buffer(sci);
1422 if (unlikely(err))
1423 goto failed;
1424
1425 err = nilfs_segctor_collect_blocks(sci, mode);
1426 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1427 if (!err)
1428 break;
1429
1430 if (unlikely(err != -E2BIG))
1431 goto failed;
1432
1433 /* The current segment is filled up */
1434 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
1435 break;
1436
1437 nilfs_clear_logs(&sci->sc_segbufs);
1438
1439 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1440 if (unlikely(err))
1441 return err;
1442
1443 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1444 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1445 sci->sc_freesegs,
1446 sci->sc_nfreesegs,
1447 NULL);
1448 WARN_ON(err); /* do not happen */
1449 }
1450 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1451 sci->sc_stage = prev_stage;
1452 }
1453 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1454 return 0;
1455
1456 failed:
1457 return err;
1458 }
1459
1460 static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1461 struct buffer_head *new_bh)
1462 {
1463 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1464
1465 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1466 /* The caller must release old_bh */
1467 }
1468
1469 static int
1470 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1471 struct nilfs_segment_buffer *segbuf,
1472 int mode)
1473 {
1474 struct inode *inode = NULL;
1475 sector_t blocknr;
1476 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1477 unsigned long nblocks = 0, ndatablk = 0;
1478 struct nilfs_sc_operations *sc_op = NULL;
1479 struct nilfs_segsum_pointer ssp;
1480 struct nilfs_finfo *finfo = NULL;
1481 union nilfs_binfo binfo;
1482 struct buffer_head *bh, *bh_org;
1483 ino_t ino = 0;
1484 int err = 0;
1485
1486 if (!nfinfo)
1487 goto out;
1488
1489 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1490 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1491 ssp.offset = sizeof(struct nilfs_segment_summary);
1492
1493 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1494 if (bh == segbuf->sb_super_root)
1495 break;
1496 if (!finfo) {
1497 finfo = nilfs_segctor_map_segsum_entry(
1498 sci, &ssp, sizeof(*finfo));
1499 ino = le64_to_cpu(finfo->fi_ino);
1500 nblocks = le32_to_cpu(finfo->fi_nblocks);
1501 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1502
1503 if (buffer_nilfs_node(bh))
1504 inode = NILFS_BTNC_I(bh->b_page->mapping);
1505 else
1506 inode = NILFS_AS_I(bh->b_page->mapping);
1507
1508 if (mode == SC_LSEG_DSYNC)
1509 sc_op = &nilfs_sc_dsync_ops;
1510 else if (ino == NILFS_DAT_INO)
1511 sc_op = &nilfs_sc_dat_ops;
1512 else /* file blocks */
1513 sc_op = &nilfs_sc_file_ops;
1514 }
1515 bh_org = bh;
1516 get_bh(bh_org);
1517 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1518 &binfo);
1519 if (bh != bh_org)
1520 nilfs_list_replace_buffer(bh_org, bh);
1521 brelse(bh_org);
1522 if (unlikely(err))
1523 goto failed_bmap;
1524
1525 if (ndatablk > 0)
1526 sc_op->write_data_binfo(sci, &ssp, &binfo);
1527 else
1528 sc_op->write_node_binfo(sci, &ssp, &binfo);
1529
1530 blocknr++;
1531 if (--nblocks == 0) {
1532 finfo = NULL;
1533 if (--nfinfo == 0)
1534 break;
1535 } else if (ndatablk > 0)
1536 ndatablk--;
1537 }
1538 out:
1539 return 0;
1540
1541 failed_bmap:
1542 return err;
1543 }
1544
1545 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1546 {
1547 struct nilfs_segment_buffer *segbuf;
1548 int err;
1549
1550 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1551 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1552 if (unlikely(err))
1553 return err;
1554 nilfs_segbuf_fill_in_segsum(segbuf);
1555 }
1556 return 0;
1557 }
1558
1559 static int
1560 nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out)
1561 {
1562 struct page *clone_page;
1563 struct buffer_head *bh, *head, *bh2;
1564 void *kaddr;
1565
1566 bh = head = page_buffers(page);
1567
1568 clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0);
1569 if (unlikely(!clone_page))
1570 return -ENOMEM;
1571
1572 bh2 = page_buffers(clone_page);
1573 kaddr = kmap_atomic(page, KM_USER0);
1574 do {
1575 if (list_empty(&bh->b_assoc_buffers))
1576 continue;
1577 get_bh(bh2);
1578 page_cache_get(clone_page); /* for each bh */
1579 memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size);
1580 bh2->b_blocknr = bh->b_blocknr;
1581 list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers);
1582 list_add_tail(&bh->b_assoc_buffers, out);
1583 } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head);
1584 kunmap_atomic(kaddr, KM_USER0);
1585
1586 if (!TestSetPageWriteback(clone_page))
1587 account_page_writeback(clone_page);
1588 unlock_page(clone_page);
1589
1590 return 0;
1591 }
1592
1593 static int nilfs_test_page_to_be_frozen(struct page *page)
1594 {
1595 struct address_space *mapping = page->mapping;
1596
1597 if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode))
1598 return 0;
1599
1600 if (page_mapped(page)) {
1601 ClearPageChecked(page);
1602 return 1;
1603 }
1604 return PageChecked(page);
1605 }
1606
1607 static int nilfs_begin_page_io(struct page *page, struct list_head *out)
1608 {
1609 if (!page || PageWriteback(page))
1610 /* For split b-tree node pages, this function may be called
1611 twice. We ignore the 2nd or later calls by this check. */
1612 return 0;
1613
1614 lock_page(page);
1615 clear_page_dirty_for_io(page);
1616 set_page_writeback(page);
1617 unlock_page(page);
1618
1619 if (nilfs_test_page_to_be_frozen(page)) {
1620 int err = nilfs_copy_replace_page_buffers(page, out);
1621 if (unlikely(err))
1622 return err;
1623 }
1624 return 0;
1625 }
1626
1627 static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
1628 struct page **failed_page)
1629 {
1630 struct nilfs_segment_buffer *segbuf;
1631 struct page *bd_page = NULL, *fs_page = NULL;
1632 struct list_head *list = &sci->sc_copied_buffers;
1633 int err;
1634
1635 *failed_page = NULL;
1636 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1637 struct buffer_head *bh;
1638
1639 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1640 b_assoc_buffers) {
1641 if (bh->b_page != bd_page) {
1642 if (bd_page) {
1643 lock_page(bd_page);
1644 clear_page_dirty_for_io(bd_page);
1645 set_page_writeback(bd_page);
1646 unlock_page(bd_page);
1647 }
1648 bd_page = bh->b_page;
1649 }
1650 }
1651
1652 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1653 b_assoc_buffers) {
1654 if (bh == segbuf->sb_super_root) {
1655 if (bh->b_page != bd_page) {
1656 lock_page(bd_page);
1657 clear_page_dirty_for_io(bd_page);
1658 set_page_writeback(bd_page);
1659 unlock_page(bd_page);
1660 bd_page = bh->b_page;
1661 }
1662 break;
1663 }
1664 if (bh->b_page != fs_page) {
1665 err = nilfs_begin_page_io(fs_page, list);
1666 if (unlikely(err)) {
1667 *failed_page = fs_page;
1668 goto out;
1669 }
1670 fs_page = bh->b_page;
1671 }
1672 }
1673 }
1674 if (bd_page) {
1675 lock_page(bd_page);
1676 clear_page_dirty_for_io(bd_page);
1677 set_page_writeback(bd_page);
1678 unlock_page(bd_page);
1679 }
1680 err = nilfs_begin_page_io(fs_page, list);
1681 if (unlikely(err))
1682 *failed_page = fs_page;
1683 out:
1684 return err;
1685 }
1686
1687 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1688 struct the_nilfs *nilfs)
1689 {
1690 int ret;
1691
1692 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1693 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1694 return ret;
1695 }
1696
1697 static void __nilfs_end_page_io(struct page *page, int err)
1698 {
1699 if (!err) {
1700 if (!nilfs_page_buffers_clean(page))
1701 __set_page_dirty_nobuffers(page);
1702 ClearPageError(page);
1703 } else {
1704 __set_page_dirty_nobuffers(page);
1705 SetPageError(page);
1706 }
1707
1708 if (buffer_nilfs_allocated(page_buffers(page))) {
1709 if (TestClearPageWriteback(page))
1710 dec_zone_page_state(page, NR_WRITEBACK);
1711 } else
1712 end_page_writeback(page);
1713 }
1714
1715 static void nilfs_end_page_io(struct page *page, int err)
1716 {
1717 if (!page)
1718 return;
1719
1720 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
1721 /*
1722 * For b-tree node pages, this function may be called twice
1723 * or more because they might be split in a segment.
1724 */
1725 if (PageDirty(page)) {
1726 /*
1727 * For pages holding split b-tree node buffers, dirty
1728 * flag on the buffers may be cleared discretely.
1729 * In that case, the page is once redirtied for
1730 * remaining buffers, and it must be cancelled if
1731 * all the buffers get cleaned later.
1732 */
1733 lock_page(page);
1734 if (nilfs_page_buffers_clean(page))
1735 __nilfs_clear_page_dirty(page);
1736 unlock_page(page);
1737 }
1738 return;
1739 }
1740
1741 __nilfs_end_page_io(page, err);
1742 }
1743
1744 static void nilfs_clear_copied_buffers(struct list_head *list, int err)
1745 {
1746 struct buffer_head *bh, *head;
1747 struct page *page;
1748
1749 while (!list_empty(list)) {
1750 bh = list_entry(list->next, struct buffer_head,
1751 b_assoc_buffers);
1752 page = bh->b_page;
1753 page_cache_get(page);
1754 head = bh = page_buffers(page);
1755 do {
1756 if (!list_empty(&bh->b_assoc_buffers)) {
1757 list_del_init(&bh->b_assoc_buffers);
1758 if (!err) {
1759 set_buffer_uptodate(bh);
1760 clear_buffer_dirty(bh);
1761 clear_buffer_delay(bh);
1762 clear_buffer_nilfs_volatile(bh);
1763 }
1764 brelse(bh); /* for b_assoc_buffers */
1765 }
1766 } while ((bh = bh->b_this_page) != head);
1767
1768 __nilfs_end_page_io(page, err);
1769 page_cache_release(page);
1770 }
1771 }
1772
1773 static void nilfs_abort_logs(struct list_head *logs, struct page *failed_page,
1774 int err)
1775 {
1776 struct nilfs_segment_buffer *segbuf;
1777 struct page *bd_page = NULL, *fs_page = NULL;
1778 struct buffer_head *bh;
1779
1780 if (list_empty(logs))
1781 return;
1782
1783 list_for_each_entry(segbuf, logs, sb_list) {
1784 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1785 b_assoc_buffers) {
1786 if (bh->b_page != bd_page) {
1787 if (bd_page)
1788 end_page_writeback(bd_page);
1789 bd_page = bh->b_page;
1790 }
1791 }
1792
1793 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1794 b_assoc_buffers) {
1795 if (bh == segbuf->sb_super_root) {
1796 if (bh->b_page != bd_page) {
1797 end_page_writeback(bd_page);
1798 bd_page = bh->b_page;
1799 }
1800 break;
1801 }
1802 if (bh->b_page != fs_page) {
1803 nilfs_end_page_io(fs_page, err);
1804 if (fs_page && fs_page == failed_page)
1805 return;
1806 fs_page = bh->b_page;
1807 }
1808 }
1809 }
1810 if (bd_page)
1811 end_page_writeback(bd_page);
1812
1813 nilfs_end_page_io(fs_page, err);
1814 }
1815
1816 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1817 struct the_nilfs *nilfs, int err)
1818 {
1819 LIST_HEAD(logs);
1820 int ret;
1821
1822 list_splice_tail_init(&sci->sc_write_logs, &logs);
1823 ret = nilfs_wait_on_logs(&logs);
1824 nilfs_abort_logs(&logs, NULL, ret ? : err);
1825
1826 list_splice_tail_init(&sci->sc_segbufs, &logs);
1827 nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1828 nilfs_free_incomplete_logs(&logs, nilfs);
1829 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err);
1830
1831 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1832 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1833 sci->sc_freesegs,
1834 sci->sc_nfreesegs,
1835 NULL);
1836 WARN_ON(ret); /* do not happen */
1837 }
1838
1839 nilfs_destroy_logs(&logs);
1840 }
1841
1842 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1843 struct nilfs_segment_buffer *segbuf)
1844 {
1845 nilfs->ns_segnum = segbuf->sb_segnum;
1846 nilfs->ns_nextnum = segbuf->sb_nextnum;
1847 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1848 + segbuf->sb_sum.nblocks;
1849 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1850 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1851 }
1852
1853 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1854 {
1855 struct nilfs_segment_buffer *segbuf;
1856 struct page *bd_page = NULL, *fs_page = NULL;
1857 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1858 int update_sr = false;
1859
1860 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1861 struct buffer_head *bh;
1862
1863 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1864 b_assoc_buffers) {
1865 set_buffer_uptodate(bh);
1866 clear_buffer_dirty(bh);
1867 if (bh->b_page != bd_page) {
1868 if (bd_page)
1869 end_page_writeback(bd_page);
1870 bd_page = bh->b_page;
1871 }
1872 }
1873 /*
1874 * We assume that the buffers which belong to the same page
1875 * continue over the buffer list.
1876 * Under this assumption, the last BHs of pages is
1877 * identifiable by the discontinuity of bh->b_page
1878 * (page != fs_page).
1879 *
1880 * For B-tree node blocks, however, this assumption is not
1881 * guaranteed. The cleanup code of B-tree node pages needs
1882 * special care.
1883 */
1884 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1885 b_assoc_buffers) {
1886 set_buffer_uptodate(bh);
1887 clear_buffer_dirty(bh);
1888 clear_buffer_delay(bh);
1889 clear_buffer_nilfs_volatile(bh);
1890 clear_buffer_nilfs_redirected(bh);
1891 if (bh == segbuf->sb_super_root) {
1892 if (bh->b_page != bd_page) {
1893 end_page_writeback(bd_page);
1894 bd_page = bh->b_page;
1895 }
1896 update_sr = true;
1897 break;
1898 }
1899 if (bh->b_page != fs_page) {
1900 nilfs_end_page_io(fs_page, 0);
1901 fs_page = bh->b_page;
1902 }
1903 }
1904
1905 if (!nilfs_segbuf_simplex(segbuf)) {
1906 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
1907 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1908 sci->sc_lseg_stime = jiffies;
1909 }
1910 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
1911 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1912 }
1913 }
1914 /*
1915 * Since pages may continue over multiple segment buffers,
1916 * end of the last page must be checked outside of the loop.
1917 */
1918 if (bd_page)
1919 end_page_writeback(bd_page);
1920
1921 nilfs_end_page_io(fs_page, 0);
1922
1923 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, 0);
1924
1925 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1926
1927 if (nilfs_doing_gc())
1928 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1929 else
1930 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1931
1932 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1933
1934 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1935 nilfs_set_next_segment(nilfs, segbuf);
1936
1937 if (update_sr) {
1938 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
1939 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
1940
1941 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
1942 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1943 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1944 nilfs_segctor_clear_metadata_dirty(sci);
1945 } else
1946 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1947 }
1948
1949 static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
1950 {
1951 int ret;
1952
1953 ret = nilfs_wait_on_logs(&sci->sc_write_logs);
1954 if (!ret) {
1955 nilfs_segctor_complete_write(sci);
1956 nilfs_destroy_logs(&sci->sc_write_logs);
1957 }
1958 return ret;
1959 }
1960
1961 static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci,
1962 struct the_nilfs *nilfs)
1963 {
1964 struct nilfs_inode_info *ii, *n;
1965 struct inode *ifile = sci->sc_root->ifile;
1966
1967 spin_lock(&nilfs->ns_inode_lock);
1968 retry:
1969 list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) {
1970 if (!ii->i_bh) {
1971 struct buffer_head *ibh;
1972 int err;
1973
1974 spin_unlock(&nilfs->ns_inode_lock);
1975 err = nilfs_ifile_get_inode_block(
1976 ifile, ii->vfs_inode.i_ino, &ibh);
1977 if (unlikely(err)) {
1978 nilfs_warning(sci->sc_super, __func__,
1979 "failed to get inode block.\n");
1980 return err;
1981 }
1982 nilfs_mdt_mark_buffer_dirty(ibh);
1983 nilfs_mdt_mark_dirty(ifile);
1984 spin_lock(&nilfs->ns_inode_lock);
1985 if (likely(!ii->i_bh))
1986 ii->i_bh = ibh;
1987 else
1988 brelse(ibh);
1989 goto retry;
1990 }
1991
1992 clear_bit(NILFS_I_QUEUED, &ii->i_state);
1993 set_bit(NILFS_I_BUSY, &ii->i_state);
1994 list_del(&ii->i_dirty);
1995 list_add_tail(&ii->i_dirty, &sci->sc_dirty_files);
1996 }
1997 spin_unlock(&nilfs->ns_inode_lock);
1998
1999 return 0;
2000 }
2001
2002 static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
2003 struct the_nilfs *nilfs)
2004 {
2005 struct nilfs_transaction_info *ti = current->journal_info;
2006 struct nilfs_inode_info *ii, *n;
2007
2008 spin_lock(&nilfs->ns_inode_lock);
2009 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
2010 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
2011 test_bit(NILFS_I_DIRTY, &ii->i_state))
2012 continue;
2013
2014 clear_bit(NILFS_I_BUSY, &ii->i_state);
2015 brelse(ii->i_bh);
2016 ii->i_bh = NULL;
2017 list_del(&ii->i_dirty);
2018 list_add_tail(&ii->i_dirty, &ti->ti_garbage);
2019 }
2020 spin_unlock(&nilfs->ns_inode_lock);
2021 }
2022
2023 /*
2024 * Main procedure of segment constructor
2025 */
2026 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2027 {
2028 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2029 struct page *failed_page;
2030 int err;
2031
2032 sci->sc_stage.scnt = NILFS_ST_INIT;
2033 sci->sc_cno = nilfs->ns_cno;
2034
2035 err = nilfs_segctor_collect_dirty_files(sci, nilfs);
2036 if (unlikely(err))
2037 goto out;
2038
2039 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
2040 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2041
2042 if (nilfs_segctor_clean(sci))
2043 goto out;
2044
2045 do {
2046 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2047
2048 err = nilfs_segctor_begin_construction(sci, nilfs);
2049 if (unlikely(err))
2050 goto out;
2051
2052 /* Update time stamp */
2053 sci->sc_seg_ctime = get_seconds();
2054
2055 err = nilfs_segctor_collect(sci, nilfs, mode);
2056 if (unlikely(err))
2057 goto failed;
2058
2059 /* Avoid empty segment */
2060 if (sci->sc_stage.scnt == NILFS_ST_DONE &&
2061 nilfs_segbuf_empty(sci->sc_curseg)) {
2062 nilfs_segctor_abort_construction(sci, nilfs, 1);
2063 goto out;
2064 }
2065
2066 err = nilfs_segctor_assign(sci, mode);
2067 if (unlikely(err))
2068 goto failed;
2069
2070 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2071 nilfs_segctor_fill_in_file_bmap(sci);
2072
2073 if (mode == SC_LSEG_SR &&
2074 sci->sc_stage.scnt >= NILFS_ST_CPFILE) {
2075 err = nilfs_segctor_fill_in_checkpoint(sci);
2076 if (unlikely(err))
2077 goto failed_to_write;
2078
2079 nilfs_segctor_fill_in_super_root(sci, nilfs);
2080 }
2081 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2082
2083 /* Write partial segments */
2084 err = nilfs_segctor_prepare_write(sci, &failed_page);
2085 if (err) {
2086 nilfs_abort_logs(&sci->sc_segbufs, failed_page, err);
2087 goto failed_to_write;
2088 }
2089
2090 nilfs_add_checksums_on_logs(&sci->sc_segbufs,
2091 nilfs->ns_crc_seed);
2092
2093 err = nilfs_segctor_write(sci, nilfs);
2094 if (unlikely(err))
2095 goto failed_to_write;
2096
2097 if (sci->sc_stage.scnt == NILFS_ST_DONE ||
2098 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
2099 /*
2100 * At this point, we avoid double buffering
2101 * for blocksize < pagesize because page dirty
2102 * flag is turned off during write and dirty
2103 * buffers are not properly collected for
2104 * pages crossing over segments.
2105 */
2106 err = nilfs_segctor_wait(sci);
2107 if (err)
2108 goto failed_to_write;
2109 }
2110 } while (sci->sc_stage.scnt != NILFS_ST_DONE);
2111
2112 out:
2113 nilfs_segctor_drop_written_files(sci, nilfs);
2114 return err;
2115
2116 failed_to_write:
2117 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2118 nilfs_redirty_inodes(&sci->sc_dirty_files);
2119
2120 failed:
2121 if (nilfs_doing_gc())
2122 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2123 nilfs_segctor_abort_construction(sci, nilfs, err);
2124 goto out;
2125 }
2126
2127 /**
2128 * nilfs_segctor_start_timer - set timer of background write
2129 * @sci: nilfs_sc_info
2130 *
2131 * If the timer has already been set, it ignores the new request.
2132 * This function MUST be called within a section locking the segment
2133 * semaphore.
2134 */
2135 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2136 {
2137 spin_lock(&sci->sc_state_lock);
2138 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2139 sci->sc_timer.expires = jiffies + sci->sc_interval;
2140 add_timer(&sci->sc_timer);
2141 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2142 }
2143 spin_unlock(&sci->sc_state_lock);
2144 }
2145
2146 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2147 {
2148 spin_lock(&sci->sc_state_lock);
2149 if (!(sci->sc_flush_request & (1 << bn))) {
2150 unsigned long prev_req = sci->sc_flush_request;
2151
2152 sci->sc_flush_request |= (1 << bn);
2153 if (!prev_req)
2154 wake_up(&sci->sc_wait_daemon);
2155 }
2156 spin_unlock(&sci->sc_state_lock);
2157 }
2158
2159 /**
2160 * nilfs_flush_segment - trigger a segment construction for resource control
2161 * @sb: super block
2162 * @ino: inode number of the file to be flushed out.
2163 */
2164 void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2165 {
2166 struct the_nilfs *nilfs = sb->s_fs_info;
2167 struct nilfs_sc_info *sci = nilfs->ns_writer;
2168
2169 if (!sci || nilfs_doing_construction())
2170 return;
2171 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2172 /* assign bit 0 to data files */
2173 }
2174
2175 struct nilfs_segctor_wait_request {
2176 wait_queue_t wq;
2177 __u32 seq;
2178 int err;
2179 atomic_t done;
2180 };
2181
2182 static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2183 {
2184 struct nilfs_segctor_wait_request wait_req;
2185 int err = 0;
2186
2187 spin_lock(&sci->sc_state_lock);
2188 init_wait(&wait_req.wq);
2189 wait_req.err = 0;
2190 atomic_set(&wait_req.done, 0);
2191 wait_req.seq = ++sci->sc_seq_request;
2192 spin_unlock(&sci->sc_state_lock);
2193
2194 init_waitqueue_entry(&wait_req.wq, current);
2195 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2196 set_current_state(TASK_INTERRUPTIBLE);
2197 wake_up(&sci->sc_wait_daemon);
2198
2199 for (;;) {
2200 if (atomic_read(&wait_req.done)) {
2201 err = wait_req.err;
2202 break;
2203 }
2204 if (!signal_pending(current)) {
2205 schedule();
2206 continue;
2207 }
2208 err = -ERESTARTSYS;
2209 break;
2210 }
2211 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2212 return err;
2213 }
2214
2215 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2216 {
2217 struct nilfs_segctor_wait_request *wrq, *n;
2218 unsigned long flags;
2219
2220 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2221 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2222 wq.task_list) {
2223 if (!atomic_read(&wrq->done) &&
2224 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2225 wrq->err = err;
2226 atomic_set(&wrq->done, 1);
2227 }
2228 if (atomic_read(&wrq->done)) {
2229 wrq->wq.func(&wrq->wq,
2230 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2231 0, NULL);
2232 }
2233 }
2234 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2235 }
2236
2237 /**
2238 * nilfs_construct_segment - construct a logical segment
2239 * @sb: super block
2240 *
2241 * Return Value: On success, 0 is retured. On errors, one of the following
2242 * negative error code is returned.
2243 *
2244 * %-EROFS - Read only filesystem.
2245 *
2246 * %-EIO - I/O error
2247 *
2248 * %-ENOSPC - No space left on device (only in a panic state).
2249 *
2250 * %-ERESTARTSYS - Interrupted.
2251 *
2252 * %-ENOMEM - Insufficient memory available.
2253 */
2254 int nilfs_construct_segment(struct super_block *sb)
2255 {
2256 struct the_nilfs *nilfs = sb->s_fs_info;
2257 struct nilfs_sc_info *sci = nilfs->ns_writer;
2258 struct nilfs_transaction_info *ti;
2259 int err;
2260
2261 if (!sci)
2262 return -EROFS;
2263
2264 /* A call inside transactions causes a deadlock. */
2265 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2266
2267 err = nilfs_segctor_sync(sci);
2268 return err;
2269 }
2270
2271 /**
2272 * nilfs_construct_dsync_segment - construct a data-only logical segment
2273 * @sb: super block
2274 * @inode: inode whose data blocks should be written out
2275 * @start: start byte offset
2276 * @end: end byte offset (inclusive)
2277 *
2278 * Return Value: On success, 0 is retured. On errors, one of the following
2279 * negative error code is returned.
2280 *
2281 * %-EROFS - Read only filesystem.
2282 *
2283 * %-EIO - I/O error
2284 *
2285 * %-ENOSPC - No space left on device (only in a panic state).
2286 *
2287 * %-ERESTARTSYS - Interrupted.
2288 *
2289 * %-ENOMEM - Insufficient memory available.
2290 */
2291 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2292 loff_t start, loff_t end)
2293 {
2294 struct the_nilfs *nilfs = sb->s_fs_info;
2295 struct nilfs_sc_info *sci = nilfs->ns_writer;
2296 struct nilfs_inode_info *ii;
2297 struct nilfs_transaction_info ti;
2298 int err = 0;
2299
2300 if (!sci)
2301 return -EROFS;
2302
2303 nilfs_transaction_lock(sb, &ti, 0);
2304
2305 ii = NILFS_I(inode);
2306 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
2307 nilfs_test_opt(nilfs, STRICT_ORDER) ||
2308 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2309 nilfs_discontinued(nilfs)) {
2310 nilfs_transaction_unlock(sb);
2311 err = nilfs_segctor_sync(sci);
2312 return err;
2313 }
2314
2315 spin_lock(&nilfs->ns_inode_lock);
2316 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2317 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2318 spin_unlock(&nilfs->ns_inode_lock);
2319 nilfs_transaction_unlock(sb);
2320 return 0;
2321 }
2322 spin_unlock(&nilfs->ns_inode_lock);
2323 sci->sc_dsync_inode = ii;
2324 sci->sc_dsync_start = start;
2325 sci->sc_dsync_end = end;
2326
2327 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2328
2329 nilfs_transaction_unlock(sb);
2330 return err;
2331 }
2332
2333 #define FLUSH_FILE_BIT (0x1) /* data file only */
2334 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2335
2336 /**
2337 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2338 * @sci: segment constructor object
2339 */
2340 static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2341 {
2342 spin_lock(&sci->sc_state_lock);
2343 sci->sc_seq_accepted = sci->sc_seq_request;
2344 spin_unlock(&sci->sc_state_lock);
2345 del_timer_sync(&sci->sc_timer);
2346 }
2347
2348 /**
2349 * nilfs_segctor_notify - notify the result of request to caller threads
2350 * @sci: segment constructor object
2351 * @mode: mode of log forming
2352 * @err: error code to be notified
2353 */
2354 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2355 {
2356 /* Clear requests (even when the construction failed) */
2357 spin_lock(&sci->sc_state_lock);
2358
2359 if (mode == SC_LSEG_SR) {
2360 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2361 sci->sc_seq_done = sci->sc_seq_accepted;
2362 nilfs_segctor_wakeup(sci, err);
2363 sci->sc_flush_request = 0;
2364 } else {
2365 if (mode == SC_FLUSH_FILE)
2366 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2367 else if (mode == SC_FLUSH_DAT)
2368 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2369
2370 /* re-enable timer if checkpoint creation was not done */
2371 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2372 time_before(jiffies, sci->sc_timer.expires))
2373 add_timer(&sci->sc_timer);
2374 }
2375 spin_unlock(&sci->sc_state_lock);
2376 }
2377
2378 /**
2379 * nilfs_segctor_construct - form logs and write them to disk
2380 * @sci: segment constructor object
2381 * @mode: mode of log forming
2382 */
2383 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2384 {
2385 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2386 struct nilfs_super_block **sbp;
2387 int err = 0;
2388
2389 nilfs_segctor_accept(sci);
2390
2391 if (nilfs_discontinued(nilfs))
2392 mode = SC_LSEG_SR;
2393 if (!nilfs_segctor_confirm(sci))
2394 err = nilfs_segctor_do_construct(sci, mode);
2395
2396 if (likely(!err)) {
2397 if (mode != SC_FLUSH_DAT)
2398 atomic_set(&nilfs->ns_ndirtyblks, 0);
2399 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2400 nilfs_discontinued(nilfs)) {
2401 down_write(&nilfs->ns_sem);
2402 err = -EIO;
2403 sbp = nilfs_prepare_super(sci->sc_super,
2404 nilfs_sb_will_flip(nilfs));
2405 if (likely(sbp)) {
2406 nilfs_set_log_cursor(sbp[0], nilfs);
2407 err = nilfs_commit_super(sci->sc_super,
2408 NILFS_SB_COMMIT);
2409 }
2410 up_write(&nilfs->ns_sem);
2411 }
2412 }
2413
2414 nilfs_segctor_notify(sci, mode, err);
2415 return err;
2416 }
2417
2418 static void nilfs_construction_timeout(unsigned long data)
2419 {
2420 struct task_struct *p = (struct task_struct *)data;
2421 wake_up_process(p);
2422 }
2423
2424 static void
2425 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2426 {
2427 struct nilfs_inode_info *ii, *n;
2428
2429 list_for_each_entry_safe(ii, n, head, i_dirty) {
2430 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2431 continue;
2432 list_del_init(&ii->i_dirty);
2433 iput(&ii->vfs_inode);
2434 }
2435 }
2436
2437 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2438 void **kbufs)
2439 {
2440 struct the_nilfs *nilfs = sb->s_fs_info;
2441 struct nilfs_sc_info *sci = nilfs->ns_writer;
2442 struct nilfs_transaction_info ti;
2443 int err;
2444
2445 if (unlikely(!sci))
2446 return -EROFS;
2447
2448 nilfs_transaction_lock(sb, &ti, 1);
2449
2450 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2451 if (unlikely(err))
2452 goto out_unlock;
2453
2454 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2455 if (unlikely(err)) {
2456 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2457 goto out_unlock;
2458 }
2459
2460 sci->sc_freesegs = kbufs[4];
2461 sci->sc_nfreesegs = argv[4].v_nmembs;
2462 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2463
2464 for (;;) {
2465 err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2466 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2467
2468 if (likely(!err))
2469 break;
2470
2471 nilfs_warning(sb, __func__,
2472 "segment construction failed. (err=%d)", err);
2473 set_current_state(TASK_INTERRUPTIBLE);
2474 schedule_timeout(sci->sc_interval);
2475 }
2476 if (nilfs_test_opt(nilfs, DISCARD)) {
2477 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2478 sci->sc_nfreesegs);
2479 if (ret) {
2480 printk(KERN_WARNING
2481 "NILFS warning: error %d on discard request, "
2482 "turning discards off for the device\n", ret);
2483 nilfs_clear_opt(nilfs, DISCARD);
2484 }
2485 }
2486
2487 out_unlock:
2488 sci->sc_freesegs = NULL;
2489 sci->sc_nfreesegs = 0;
2490 nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2491 nilfs_transaction_unlock(sb);
2492 return err;
2493 }
2494
2495 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2496 {
2497 struct nilfs_transaction_info ti;
2498
2499 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2500 nilfs_segctor_construct(sci, mode);
2501
2502 /*
2503 * Unclosed segment should be retried. We do this using sc_timer.
2504 * Timeout of sc_timer will invoke complete construction which leads
2505 * to close the current logical segment.
2506 */
2507 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2508 nilfs_segctor_start_timer(sci);
2509
2510 nilfs_transaction_unlock(sci->sc_super);
2511 }
2512
2513 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2514 {
2515 int mode = 0;
2516 int err;
2517
2518 spin_lock(&sci->sc_state_lock);
2519 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2520 SC_FLUSH_DAT : SC_FLUSH_FILE;
2521 spin_unlock(&sci->sc_state_lock);
2522
2523 if (mode) {
2524 err = nilfs_segctor_do_construct(sci, mode);
2525
2526 spin_lock(&sci->sc_state_lock);
2527 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2528 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2529 spin_unlock(&sci->sc_state_lock);
2530 }
2531 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2532 }
2533
2534 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2535 {
2536 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2537 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2538 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2539 return SC_FLUSH_FILE;
2540 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2541 return SC_FLUSH_DAT;
2542 }
2543 return SC_LSEG_SR;
2544 }
2545
2546 /**
2547 * nilfs_segctor_thread - main loop of the segment constructor thread.
2548 * @arg: pointer to a struct nilfs_sc_info.
2549 *
2550 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2551 * to execute segment constructions.
2552 */
2553 static int nilfs_segctor_thread(void *arg)
2554 {
2555 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2556 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2557 int timeout = 0;
2558
2559 sci->sc_timer.data = (unsigned long)current;
2560 sci->sc_timer.function = nilfs_construction_timeout;
2561
2562 /* start sync. */
2563 sci->sc_task = current;
2564 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2565 printk(KERN_INFO
2566 "segctord starting. Construction interval = %lu seconds, "
2567 "CP frequency < %lu seconds\n",
2568 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2569
2570 spin_lock(&sci->sc_state_lock);
2571 loop:
2572 for (;;) {
2573 int mode;
2574
2575 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2576 goto end_thread;
2577
2578 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2579 mode = SC_LSEG_SR;
2580 else if (!sci->sc_flush_request)
2581 break;
2582 else
2583 mode = nilfs_segctor_flush_mode(sci);
2584
2585 spin_unlock(&sci->sc_state_lock);
2586 nilfs_segctor_thread_construct(sci, mode);
2587 spin_lock(&sci->sc_state_lock);
2588 timeout = 0;
2589 }
2590
2591
2592 if (freezing(current)) {
2593 spin_unlock(&sci->sc_state_lock);
2594 refrigerator();
2595 spin_lock(&sci->sc_state_lock);
2596 } else {
2597 DEFINE_WAIT(wait);
2598 int should_sleep = 1;
2599
2600 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2601 TASK_INTERRUPTIBLE);
2602
2603 if (sci->sc_seq_request != sci->sc_seq_done)
2604 should_sleep = 0;
2605 else if (sci->sc_flush_request)
2606 should_sleep = 0;
2607 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2608 should_sleep = time_before(jiffies,
2609 sci->sc_timer.expires);
2610
2611 if (should_sleep) {
2612 spin_unlock(&sci->sc_state_lock);
2613 schedule();
2614 spin_lock(&sci->sc_state_lock);
2615 }
2616 finish_wait(&sci->sc_wait_daemon, &wait);
2617 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2618 time_after_eq(jiffies, sci->sc_timer.expires));
2619
2620 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2621 set_nilfs_discontinued(nilfs);
2622 }
2623 goto loop;
2624
2625 end_thread:
2626 spin_unlock(&sci->sc_state_lock);
2627
2628 /* end sync. */
2629 sci->sc_task = NULL;
2630 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2631 return 0;
2632 }
2633
2634 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2635 {
2636 struct task_struct *t;
2637
2638 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2639 if (IS_ERR(t)) {
2640 int err = PTR_ERR(t);
2641
2642 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2643 err);
2644 return err;
2645 }
2646 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2647 return 0;
2648 }
2649
2650 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2651 __acquires(&sci->sc_state_lock)
2652 __releases(&sci->sc_state_lock)
2653 {
2654 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2655
2656 while (sci->sc_task) {
2657 wake_up(&sci->sc_wait_daemon);
2658 spin_unlock(&sci->sc_state_lock);
2659 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2660 spin_lock(&sci->sc_state_lock);
2661 }
2662 }
2663
2664 /*
2665 * Setup & clean-up functions
2666 */
2667 static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
2668 struct nilfs_root *root)
2669 {
2670 struct the_nilfs *nilfs = sb->s_fs_info;
2671 struct nilfs_sc_info *sci;
2672
2673 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2674 if (!sci)
2675 return NULL;
2676
2677 sci->sc_super = sb;
2678
2679 nilfs_get_root(root);
2680 sci->sc_root = root;
2681
2682 init_waitqueue_head(&sci->sc_wait_request);
2683 init_waitqueue_head(&sci->sc_wait_daemon);
2684 init_waitqueue_head(&sci->sc_wait_task);
2685 spin_lock_init(&sci->sc_state_lock);
2686 INIT_LIST_HEAD(&sci->sc_dirty_files);
2687 INIT_LIST_HEAD(&sci->sc_segbufs);
2688 INIT_LIST_HEAD(&sci->sc_write_logs);
2689 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2690 INIT_LIST_HEAD(&sci->sc_copied_buffers);
2691 init_timer(&sci->sc_timer);
2692
2693 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2694 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2695 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2696
2697 if (nilfs->ns_interval)
2698 sci->sc_interval = nilfs->ns_interval;
2699 if (nilfs->ns_watermark)
2700 sci->sc_watermark = nilfs->ns_watermark;
2701 return sci;
2702 }
2703
2704 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2705 {
2706 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2707
2708 /* The segctord thread was stopped and its timer was removed.
2709 But some tasks remain. */
2710 do {
2711 struct nilfs_transaction_info ti;
2712
2713 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2714 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2715 nilfs_transaction_unlock(sci->sc_super);
2716
2717 } while (ret && retrycount-- > 0);
2718 }
2719
2720 /**
2721 * nilfs_segctor_destroy - destroy the segment constructor.
2722 * @sci: nilfs_sc_info
2723 *
2724 * nilfs_segctor_destroy() kills the segctord thread and frees
2725 * the nilfs_sc_info struct.
2726 * Caller must hold the segment semaphore.
2727 */
2728 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2729 {
2730 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2731 int flag;
2732
2733 up_write(&nilfs->ns_segctor_sem);
2734
2735 spin_lock(&sci->sc_state_lock);
2736 nilfs_segctor_kill_thread(sci);
2737 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2738 || sci->sc_seq_request != sci->sc_seq_done);
2739 spin_unlock(&sci->sc_state_lock);
2740
2741 if (flag || !nilfs_segctor_confirm(sci))
2742 nilfs_segctor_write_out(sci);
2743
2744 WARN_ON(!list_empty(&sci->sc_copied_buffers));
2745
2746 if (!list_empty(&sci->sc_dirty_files)) {
2747 nilfs_warning(sci->sc_super, __func__,
2748 "dirty file(s) after the final construction\n");
2749 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
2750 }
2751
2752 WARN_ON(!list_empty(&sci->sc_segbufs));
2753 WARN_ON(!list_empty(&sci->sc_write_logs));
2754
2755 nilfs_put_root(sci->sc_root);
2756
2757 down_write(&nilfs->ns_segctor_sem);
2758
2759 del_timer_sync(&sci->sc_timer);
2760 kfree(sci);
2761 }
2762
2763 /**
2764 * nilfs_attach_log_writer - attach log writer
2765 * @sb: super block instance
2766 * @root: root object of the current filesystem tree
2767 *
2768 * This allocates a log writer object, initializes it, and starts the
2769 * log writer.
2770 *
2771 * Return Value: On success, 0 is returned. On error, one of the following
2772 * negative error code is returned.
2773 *
2774 * %-ENOMEM - Insufficient memory available.
2775 */
2776 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
2777 {
2778 struct the_nilfs *nilfs = sb->s_fs_info;
2779 int err;
2780
2781 if (nilfs->ns_writer) {
2782 /*
2783 * This happens if the filesystem was remounted
2784 * read/write after nilfs_error degenerated it into a
2785 * read-only mount.
2786 */
2787 nilfs_detach_log_writer(sb);
2788 }
2789
2790 nilfs->ns_writer = nilfs_segctor_new(sb, root);
2791 if (!nilfs->ns_writer)
2792 return -ENOMEM;
2793
2794 err = nilfs_segctor_start_thread(nilfs->ns_writer);
2795 if (err) {
2796 kfree(nilfs->ns_writer);
2797 nilfs->ns_writer = NULL;
2798 }
2799 return err;
2800 }
2801
2802 /**
2803 * nilfs_detach_log_writer - destroy log writer
2804 * @sb: super block instance
2805 *
2806 * This kills log writer daemon, frees the log writer object, and
2807 * destroys list of dirty files.
2808 */
2809 void nilfs_detach_log_writer(struct super_block *sb)
2810 {
2811 struct the_nilfs *nilfs = sb->s_fs_info;
2812 LIST_HEAD(garbage_list);
2813
2814 down_write(&nilfs->ns_segctor_sem);
2815 if (nilfs->ns_writer) {
2816 nilfs_segctor_destroy(nilfs->ns_writer);
2817 nilfs->ns_writer = NULL;
2818 }
2819
2820 /* Force to free the list of dirty files */
2821 spin_lock(&nilfs->ns_inode_lock);
2822 if (!list_empty(&nilfs->ns_dirty_files)) {
2823 list_splice_init(&nilfs->ns_dirty_files, &garbage_list);
2824 nilfs_warning(sb, __func__,
2825 "Hit dirty file after stopped log writer\n");
2826 }
2827 spin_unlock(&nilfs->ns_inode_lock);
2828 up_write(&nilfs->ns_segctor_sem);
2829
2830 nilfs_dispose_list(nilfs, &garbage_list, 1);
2831 }
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