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Merge tag 'v3.10.69' into update
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / nilfs2 / segment.c
1 /*
2 * segment.c - NILFS segment constructor.
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
21 *
22 */
23
24 #include <linux/pagemap.h>
25 #include <linux/buffer_head.h>
26 #include <linux/writeback.h>
27 #include <linux/bio.h>
28 #include <linux/completion.h>
29 #include <linux/blkdev.h>
30 #include <linux/backing-dev.h>
31 #include <linux/freezer.h>
32 #include <linux/kthread.h>
33 #include <linux/crc32.h>
34 #include <linux/pagevec.h>
35 #include <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 sb_start_intwrite(sb);
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 sb_end_intwrite(sb);
209 return ret;
210 }
211
212 /**
213 * nilfs_transaction_commit - commit indivisible file operations.
214 * @sb: super block
215 *
216 * nilfs_transaction_commit() releases the read semaphore which is
217 * acquired by nilfs_transaction_begin(). This is only performed
218 * in outermost call of this function. If a commit flag is set,
219 * nilfs_transaction_commit() sets a timer to start the segment
220 * constructor. If a sync flag is set, it starts construction
221 * directly.
222 */
223 int nilfs_transaction_commit(struct super_block *sb)
224 {
225 struct nilfs_transaction_info *ti = current->journal_info;
226 struct the_nilfs *nilfs = sb->s_fs_info;
227 int err = 0;
228
229 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
230 ti->ti_flags |= NILFS_TI_COMMIT;
231 if (ti->ti_count > 0) {
232 ti->ti_count--;
233 return 0;
234 }
235 if (nilfs->ns_writer) {
236 struct nilfs_sc_info *sci = nilfs->ns_writer;
237
238 if (ti->ti_flags & NILFS_TI_COMMIT)
239 nilfs_segctor_start_timer(sci);
240 if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark)
241 nilfs_segctor_do_flush(sci, 0);
242 }
243 up_read(&nilfs->ns_segctor_sem);
244 current->journal_info = ti->ti_save;
245
246 if (ti->ti_flags & NILFS_TI_SYNC)
247 err = nilfs_construct_segment(sb);
248 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
249 kmem_cache_free(nilfs_transaction_cachep, ti);
250 sb_end_intwrite(sb);
251 return err;
252 }
253
254 void nilfs_transaction_abort(struct super_block *sb)
255 {
256 struct nilfs_transaction_info *ti = current->journal_info;
257 struct the_nilfs *nilfs = sb->s_fs_info;
258
259 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
260 if (ti->ti_count > 0) {
261 ti->ti_count--;
262 return;
263 }
264 up_read(&nilfs->ns_segctor_sem);
265
266 current->journal_info = ti->ti_save;
267 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
268 kmem_cache_free(nilfs_transaction_cachep, ti);
269 sb_end_intwrite(sb);
270 }
271
272 void nilfs_relax_pressure_in_lock(struct super_block *sb)
273 {
274 struct the_nilfs *nilfs = sb->s_fs_info;
275 struct nilfs_sc_info *sci = nilfs->ns_writer;
276
277 if (!sci || !sci->sc_flush_request)
278 return;
279
280 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
281 up_read(&nilfs->ns_segctor_sem);
282
283 down_write(&nilfs->ns_segctor_sem);
284 if (sci->sc_flush_request &&
285 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
286 struct nilfs_transaction_info *ti = current->journal_info;
287
288 ti->ti_flags |= NILFS_TI_WRITER;
289 nilfs_segctor_do_immediate_flush(sci);
290 ti->ti_flags &= ~NILFS_TI_WRITER;
291 }
292 downgrade_write(&nilfs->ns_segctor_sem);
293 }
294
295 static void nilfs_transaction_lock(struct super_block *sb,
296 struct nilfs_transaction_info *ti,
297 int gcflag)
298 {
299 struct nilfs_transaction_info *cur_ti = current->journal_info;
300 struct the_nilfs *nilfs = sb->s_fs_info;
301 struct nilfs_sc_info *sci = nilfs->ns_writer;
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 current->journal_info = ti;
309
310 for (;;) {
311 down_write(&nilfs->ns_segctor_sem);
312 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags))
313 break;
314
315 nilfs_segctor_do_immediate_flush(sci);
316
317 up_write(&nilfs->ns_segctor_sem);
318 yield();
319 }
320 if (gcflag)
321 ti->ti_flags |= NILFS_TI_GC;
322 }
323
324 static void nilfs_transaction_unlock(struct super_block *sb)
325 {
326 struct nilfs_transaction_info *ti = current->journal_info;
327 struct the_nilfs *nilfs = sb->s_fs_info;
328
329 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
330 BUG_ON(ti->ti_count > 0);
331
332 up_write(&nilfs->ns_segctor_sem);
333 current->journal_info = ti->ti_save;
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 lock_page(page);
659 if (!page_has_buffers(page))
660 create_empty_buffers(page, 1 << inode->i_blkbits, 0);
661 unlock_page(page);
662
663 bh = head = page_buffers(page);
664 do {
665 if (!buffer_dirty(bh) || buffer_async_write(bh))
666 continue;
667 get_bh(bh);
668 list_add_tail(&bh->b_assoc_buffers, listp);
669 ndirties++;
670 if (unlikely(ndirties >= nlimit)) {
671 pagevec_release(&pvec);
672 cond_resched();
673 return ndirties;
674 }
675 } while (bh = bh->b_this_page, bh != head);
676 }
677 pagevec_release(&pvec);
678 cond_resched();
679 goto repeat;
680 }
681
682 static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
683 struct list_head *listp)
684 {
685 struct nilfs_inode_info *ii = NILFS_I(inode);
686 struct address_space *mapping = &ii->i_btnode_cache;
687 struct pagevec pvec;
688 struct buffer_head *bh, *head;
689 unsigned int i;
690 pgoff_t index = 0;
691
692 pagevec_init(&pvec, 0);
693
694 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
695 PAGEVEC_SIZE)) {
696 for (i = 0; i < pagevec_count(&pvec); i++) {
697 bh = head = page_buffers(pvec.pages[i]);
698 do {
699 if (buffer_dirty(bh) &&
700 !buffer_async_write(bh)) {
701 get_bh(bh);
702 list_add_tail(&bh->b_assoc_buffers,
703 listp);
704 }
705 bh = bh->b_this_page;
706 } while (bh != head);
707 }
708 pagevec_release(&pvec);
709 cond_resched();
710 }
711 }
712
713 static void nilfs_dispose_list(struct the_nilfs *nilfs,
714 struct list_head *head, int force)
715 {
716 struct nilfs_inode_info *ii, *n;
717 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
718 unsigned nv = 0;
719
720 while (!list_empty(head)) {
721 spin_lock(&nilfs->ns_inode_lock);
722 list_for_each_entry_safe(ii, n, head, i_dirty) {
723 list_del_init(&ii->i_dirty);
724 if (force) {
725 if (unlikely(ii->i_bh)) {
726 brelse(ii->i_bh);
727 ii->i_bh = NULL;
728 }
729 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
730 set_bit(NILFS_I_QUEUED, &ii->i_state);
731 list_add_tail(&ii->i_dirty,
732 &nilfs->ns_dirty_files);
733 continue;
734 }
735 ivec[nv++] = ii;
736 if (nv == SC_N_INODEVEC)
737 break;
738 }
739 spin_unlock(&nilfs->ns_inode_lock);
740
741 for (pii = ivec; nv > 0; pii++, nv--)
742 iput(&(*pii)->vfs_inode);
743 }
744 }
745
746 static void nilfs_iput_work_func(struct work_struct *work)
747 {
748 struct nilfs_sc_info *sci = container_of(work, struct nilfs_sc_info,
749 sc_iput_work);
750 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
751
752 nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 0);
753 }
754
755 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
756 struct nilfs_root *root)
757 {
758 int ret = 0;
759
760 if (nilfs_mdt_fetch_dirty(root->ifile))
761 ret++;
762 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
763 ret++;
764 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
765 ret++;
766 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat))
767 ret++;
768 return ret;
769 }
770
771 static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
772 {
773 return list_empty(&sci->sc_dirty_files) &&
774 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
775 sci->sc_nfreesegs == 0 &&
776 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
777 }
778
779 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
780 {
781 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
782 int ret = 0;
783
784 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
785 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
786
787 spin_lock(&nilfs->ns_inode_lock);
788 if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci))
789 ret++;
790
791 spin_unlock(&nilfs->ns_inode_lock);
792 return ret;
793 }
794
795 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
796 {
797 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
798
799 nilfs_mdt_clear_dirty(sci->sc_root->ifile);
800 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
801 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
802 nilfs_mdt_clear_dirty(nilfs->ns_dat);
803 }
804
805 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
806 {
807 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
808 struct buffer_head *bh_cp;
809 struct nilfs_checkpoint *raw_cp;
810 int err;
811
812 /* XXX: this interface will be changed */
813 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
814 &raw_cp, &bh_cp);
815 if (likely(!err)) {
816 /* The following code is duplicated with cpfile. But, it is
817 needed to collect the checkpoint even if it was not newly
818 created */
819 mark_buffer_dirty(bh_cp);
820 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
821 nilfs_cpfile_put_checkpoint(
822 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
823 } else
824 WARN_ON(err == -EINVAL || err == -ENOENT);
825
826 return err;
827 }
828
829 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
830 {
831 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
832 struct buffer_head *bh_cp;
833 struct nilfs_checkpoint *raw_cp;
834 int err;
835
836 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
837 &raw_cp, &bh_cp);
838 if (unlikely(err)) {
839 WARN_ON(err == -EINVAL || err == -ENOENT);
840 goto failed_ibh;
841 }
842 raw_cp->cp_snapshot_list.ssl_next = 0;
843 raw_cp->cp_snapshot_list.ssl_prev = 0;
844 raw_cp->cp_inodes_count =
845 cpu_to_le64(atomic_read(&sci->sc_root->inodes_count));
846 raw_cp->cp_blocks_count =
847 cpu_to_le64(atomic_read(&sci->sc_root->blocks_count));
848 raw_cp->cp_nblk_inc =
849 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
850 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
851 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
852
853 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
854 nilfs_checkpoint_clear_minor(raw_cp);
855 else
856 nilfs_checkpoint_set_minor(raw_cp);
857
858 nilfs_write_inode_common(sci->sc_root->ifile,
859 &raw_cp->cp_ifile_inode, 1);
860 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
861 return 0;
862
863 failed_ibh:
864 return err;
865 }
866
867 static void nilfs_fill_in_file_bmap(struct inode *ifile,
868 struct nilfs_inode_info *ii)
869
870 {
871 struct buffer_head *ibh;
872 struct nilfs_inode *raw_inode;
873
874 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
875 ibh = ii->i_bh;
876 BUG_ON(!ibh);
877 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
878 ibh);
879 nilfs_bmap_write(ii->i_bmap, raw_inode);
880 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
881 }
882 }
883
884 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
885 {
886 struct nilfs_inode_info *ii;
887
888 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
889 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
890 set_bit(NILFS_I_COLLECTED, &ii->i_state);
891 }
892 }
893
894 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
895 struct the_nilfs *nilfs)
896 {
897 struct buffer_head *bh_sr;
898 struct nilfs_super_root *raw_sr;
899 unsigned isz, srsz;
900
901 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
902 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
903 isz = nilfs->ns_inode_size;
904 srsz = NILFS_SR_BYTES(isz);
905
906 raw_sr->sr_bytes = cpu_to_le16(srsz);
907 raw_sr->sr_nongc_ctime
908 = cpu_to_le64(nilfs_doing_gc() ?
909 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
910 raw_sr->sr_flags = 0;
911
912 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr +
913 NILFS_SR_DAT_OFFSET(isz), 1);
914 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
915 NILFS_SR_CPFILE_OFFSET(isz), 1);
916 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
917 NILFS_SR_SUFILE_OFFSET(isz), 1);
918 memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz);
919 }
920
921 static void nilfs_redirty_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_bit(NILFS_I_COLLECTED, &ii->i_state))
927 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
928 }
929 }
930
931 static void nilfs_drop_collected_inodes(struct list_head *head)
932 {
933 struct nilfs_inode_info *ii;
934
935 list_for_each_entry(ii, head, i_dirty) {
936 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
937 continue;
938
939 clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
940 set_bit(NILFS_I_UPDATED, &ii->i_state);
941 }
942 }
943
944 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
945 struct inode *inode,
946 struct list_head *listp,
947 int (*collect)(struct nilfs_sc_info *,
948 struct buffer_head *,
949 struct inode *))
950 {
951 struct buffer_head *bh, *n;
952 int err = 0;
953
954 if (collect) {
955 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
956 list_del_init(&bh->b_assoc_buffers);
957 err = collect(sci, bh, inode);
958 brelse(bh);
959 if (unlikely(err))
960 goto dispose_buffers;
961 }
962 return 0;
963 }
964
965 dispose_buffers:
966 while (!list_empty(listp)) {
967 bh = list_first_entry(listp, struct buffer_head,
968 b_assoc_buffers);
969 list_del_init(&bh->b_assoc_buffers);
970 brelse(bh);
971 }
972 return err;
973 }
974
975 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
976 {
977 /* Remaining number of blocks within segment buffer */
978 return sci->sc_segbuf_nblocks -
979 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
980 }
981
982 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
983 struct inode *inode,
984 struct nilfs_sc_operations *sc_ops)
985 {
986 LIST_HEAD(data_buffers);
987 LIST_HEAD(node_buffers);
988 int err;
989
990 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
991 size_t n, rest = nilfs_segctor_buffer_rest(sci);
992
993 n = nilfs_lookup_dirty_data_buffers(
994 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
995 if (n > rest) {
996 err = nilfs_segctor_apply_buffers(
997 sci, inode, &data_buffers,
998 sc_ops->collect_data);
999 BUG_ON(!err); /* always receive -E2BIG or true error */
1000 goto break_or_fail;
1001 }
1002 }
1003 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
1004
1005 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1006 err = nilfs_segctor_apply_buffers(
1007 sci, inode, &data_buffers, sc_ops->collect_data);
1008 if (unlikely(err)) {
1009 /* dispose node list */
1010 nilfs_segctor_apply_buffers(
1011 sci, inode, &node_buffers, NULL);
1012 goto break_or_fail;
1013 }
1014 sci->sc_stage.flags |= NILFS_CF_NODE;
1015 }
1016 /* Collect node */
1017 err = nilfs_segctor_apply_buffers(
1018 sci, inode, &node_buffers, sc_ops->collect_node);
1019 if (unlikely(err))
1020 goto break_or_fail;
1021
1022 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1023 err = nilfs_segctor_apply_buffers(
1024 sci, inode, &node_buffers, sc_ops->collect_bmap);
1025 if (unlikely(err))
1026 goto break_or_fail;
1027
1028 nilfs_segctor_end_finfo(sci, inode);
1029 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1030
1031 break_or_fail:
1032 return err;
1033 }
1034
1035 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1036 struct inode *inode)
1037 {
1038 LIST_HEAD(data_buffers);
1039 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1040 int err;
1041
1042 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1043 sci->sc_dsync_start,
1044 sci->sc_dsync_end);
1045
1046 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1047 nilfs_collect_file_data);
1048 if (!err) {
1049 nilfs_segctor_end_finfo(sci, inode);
1050 BUG_ON(n > rest);
1051 /* always receive -E2BIG or true error if n > rest */
1052 }
1053 return err;
1054 }
1055
1056 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1057 {
1058 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1059 struct list_head *head;
1060 struct nilfs_inode_info *ii;
1061 size_t ndone;
1062 int err = 0;
1063
1064 switch (sci->sc_stage.scnt) {
1065 case NILFS_ST_INIT:
1066 /* Pre-processes */
1067 sci->sc_stage.flags = 0;
1068
1069 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1070 sci->sc_nblk_inc = 0;
1071 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1072 if (mode == SC_LSEG_DSYNC) {
1073 sci->sc_stage.scnt = NILFS_ST_DSYNC;
1074 goto dsync_mode;
1075 }
1076 }
1077
1078 sci->sc_stage.dirty_file_ptr = NULL;
1079 sci->sc_stage.gc_inode_ptr = NULL;
1080 if (mode == SC_FLUSH_DAT) {
1081 sci->sc_stage.scnt = NILFS_ST_DAT;
1082 goto dat_stage;
1083 }
1084 sci->sc_stage.scnt++; /* Fall through */
1085 case NILFS_ST_GC:
1086 if (nilfs_doing_gc()) {
1087 head = &sci->sc_gc_inodes;
1088 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1089 head, i_dirty);
1090 list_for_each_entry_continue(ii, head, i_dirty) {
1091 err = nilfs_segctor_scan_file(
1092 sci, &ii->vfs_inode,
1093 &nilfs_sc_file_ops);
1094 if (unlikely(err)) {
1095 sci->sc_stage.gc_inode_ptr = list_entry(
1096 ii->i_dirty.prev,
1097 struct nilfs_inode_info,
1098 i_dirty);
1099 goto break_or_fail;
1100 }
1101 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1102 }
1103 sci->sc_stage.gc_inode_ptr = NULL;
1104 }
1105 sci->sc_stage.scnt++; /* Fall through */
1106 case NILFS_ST_FILE:
1107 head = &sci->sc_dirty_files;
1108 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1109 i_dirty);
1110 list_for_each_entry_continue(ii, head, i_dirty) {
1111 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1112
1113 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1114 &nilfs_sc_file_ops);
1115 if (unlikely(err)) {
1116 sci->sc_stage.dirty_file_ptr =
1117 list_entry(ii->i_dirty.prev,
1118 struct nilfs_inode_info,
1119 i_dirty);
1120 goto break_or_fail;
1121 }
1122 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1123 /* XXX: required ? */
1124 }
1125 sci->sc_stage.dirty_file_ptr = NULL;
1126 if (mode == SC_FLUSH_FILE) {
1127 sci->sc_stage.scnt = NILFS_ST_DONE;
1128 return 0;
1129 }
1130 sci->sc_stage.scnt++;
1131 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1132 /* Fall through */
1133 case NILFS_ST_IFILE:
1134 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile,
1135 &nilfs_sc_file_ops);
1136 if (unlikely(err))
1137 break;
1138 sci->sc_stage.scnt++;
1139 /* Creating a checkpoint */
1140 err = nilfs_segctor_create_checkpoint(sci);
1141 if (unlikely(err))
1142 break;
1143 /* Fall through */
1144 case NILFS_ST_CPFILE:
1145 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1146 &nilfs_sc_file_ops);
1147 if (unlikely(err))
1148 break;
1149 sci->sc_stage.scnt++; /* Fall through */
1150 case NILFS_ST_SUFILE:
1151 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1152 sci->sc_nfreesegs, &ndone);
1153 if (unlikely(err)) {
1154 nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1155 sci->sc_freesegs, ndone,
1156 NULL);
1157 break;
1158 }
1159 sci->sc_stage.flags |= NILFS_CF_SUFREED;
1160
1161 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1162 &nilfs_sc_file_ops);
1163 if (unlikely(err))
1164 break;
1165 sci->sc_stage.scnt++; /* Fall through */
1166 case NILFS_ST_DAT:
1167 dat_stage:
1168 err = nilfs_segctor_scan_file(sci, nilfs->ns_dat,
1169 &nilfs_sc_dat_ops);
1170 if (unlikely(err))
1171 break;
1172 if (mode == SC_FLUSH_DAT) {
1173 sci->sc_stage.scnt = NILFS_ST_DONE;
1174 return 0;
1175 }
1176 sci->sc_stage.scnt++; /* Fall through */
1177 case NILFS_ST_SR:
1178 if (mode == SC_LSEG_SR) {
1179 /* Appending a super root */
1180 err = nilfs_segctor_add_super_root(sci);
1181 if (unlikely(err))
1182 break;
1183 }
1184 /* End of a logical segment */
1185 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1186 sci->sc_stage.scnt = NILFS_ST_DONE;
1187 return 0;
1188 case NILFS_ST_DSYNC:
1189 dsync_mode:
1190 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1191 ii = sci->sc_dsync_inode;
1192 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1193 break;
1194
1195 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1196 if (unlikely(err))
1197 break;
1198 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1199 sci->sc_stage.scnt = NILFS_ST_DONE;
1200 return 0;
1201 case NILFS_ST_DONE:
1202 return 0;
1203 default:
1204 BUG();
1205 }
1206
1207 break_or_fail:
1208 return err;
1209 }
1210
1211 /**
1212 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1213 * @sci: nilfs_sc_info
1214 * @nilfs: nilfs object
1215 */
1216 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1217 struct the_nilfs *nilfs)
1218 {
1219 struct nilfs_segment_buffer *segbuf, *prev;
1220 __u64 nextnum;
1221 int err, alloc = 0;
1222
1223 segbuf = nilfs_segbuf_new(sci->sc_super);
1224 if (unlikely(!segbuf))
1225 return -ENOMEM;
1226
1227 if (list_empty(&sci->sc_write_logs)) {
1228 nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1229 nilfs->ns_pseg_offset, nilfs);
1230 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1231 nilfs_shift_to_next_segment(nilfs);
1232 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1233 }
1234
1235 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1236 nextnum = nilfs->ns_nextnum;
1237
1238 if (nilfs->ns_segnum == nilfs->ns_nextnum)
1239 /* Start from the head of a new full segment */
1240 alloc++;
1241 } else {
1242 /* Continue logs */
1243 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1244 nilfs_segbuf_map_cont(segbuf, prev);
1245 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1246 nextnum = prev->sb_nextnum;
1247
1248 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1249 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1250 segbuf->sb_sum.seg_seq++;
1251 alloc++;
1252 }
1253 }
1254
1255 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1256 if (err)
1257 goto failed;
1258
1259 if (alloc) {
1260 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1261 if (err)
1262 goto failed;
1263 }
1264 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1265
1266 BUG_ON(!list_empty(&sci->sc_segbufs));
1267 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1268 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1269 return 0;
1270
1271 failed:
1272 nilfs_segbuf_free(segbuf);
1273 return err;
1274 }
1275
1276 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1277 struct the_nilfs *nilfs, int nadd)
1278 {
1279 struct nilfs_segment_buffer *segbuf, *prev;
1280 struct inode *sufile = nilfs->ns_sufile;
1281 __u64 nextnextnum;
1282 LIST_HEAD(list);
1283 int err, ret, i;
1284
1285 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1286 /*
1287 * Since the segment specified with nextnum might be allocated during
1288 * the previous construction, the buffer including its segusage may
1289 * not be dirty. The following call ensures that the buffer is dirty
1290 * and will pin the buffer on memory until the sufile is written.
1291 */
1292 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1293 if (unlikely(err))
1294 return err;
1295
1296 for (i = 0; i < nadd; i++) {
1297 /* extend segment info */
1298 err = -ENOMEM;
1299 segbuf = nilfs_segbuf_new(sci->sc_super);
1300 if (unlikely(!segbuf))
1301 goto failed;
1302
1303 /* map this buffer to region of segment on-disk */
1304 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1305 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1306
1307 /* allocate the next next full segment */
1308 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1309 if (unlikely(err))
1310 goto failed_segbuf;
1311
1312 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1313 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1314
1315 list_add_tail(&segbuf->sb_list, &list);
1316 prev = segbuf;
1317 }
1318 list_splice_tail(&list, &sci->sc_segbufs);
1319 return 0;
1320
1321 failed_segbuf:
1322 nilfs_segbuf_free(segbuf);
1323 failed:
1324 list_for_each_entry(segbuf, &list, sb_list) {
1325 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1326 WARN_ON(ret); /* never fails */
1327 }
1328 nilfs_destroy_logs(&list);
1329 return err;
1330 }
1331
1332 static void nilfs_free_incomplete_logs(struct list_head *logs,
1333 struct the_nilfs *nilfs)
1334 {
1335 struct nilfs_segment_buffer *segbuf, *prev;
1336 struct inode *sufile = nilfs->ns_sufile;
1337 int ret;
1338
1339 segbuf = NILFS_FIRST_SEGBUF(logs);
1340 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1341 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1342 WARN_ON(ret); /* never fails */
1343 }
1344 if (atomic_read(&segbuf->sb_err)) {
1345 /* Case 1: The first segment failed */
1346 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1347 /* Case 1a: Partial segment appended into an existing
1348 segment */
1349 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1350 segbuf->sb_fseg_end);
1351 else /* Case 1b: New full segment */
1352 set_nilfs_discontinued(nilfs);
1353 }
1354
1355 prev = segbuf;
1356 list_for_each_entry_continue(segbuf, logs, sb_list) {
1357 if (prev->sb_nextnum != segbuf->sb_nextnum) {
1358 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1359 WARN_ON(ret); /* never fails */
1360 }
1361 if (atomic_read(&segbuf->sb_err) &&
1362 segbuf->sb_segnum != nilfs->ns_nextnum)
1363 /* Case 2: extended segment (!= next) failed */
1364 nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1365 prev = segbuf;
1366 }
1367 }
1368
1369 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1370 struct inode *sufile)
1371 {
1372 struct nilfs_segment_buffer *segbuf;
1373 unsigned long live_blocks;
1374 int ret;
1375
1376 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1377 live_blocks = segbuf->sb_sum.nblocks +
1378 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1379 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1380 live_blocks,
1381 sci->sc_seg_ctime);
1382 WARN_ON(ret); /* always succeed because the segusage is dirty */
1383 }
1384 }
1385
1386 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1387 {
1388 struct nilfs_segment_buffer *segbuf;
1389 int ret;
1390
1391 segbuf = NILFS_FIRST_SEGBUF(logs);
1392 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1393 segbuf->sb_pseg_start -
1394 segbuf->sb_fseg_start, 0);
1395 WARN_ON(ret); /* always succeed because the segusage is dirty */
1396
1397 list_for_each_entry_continue(segbuf, logs, sb_list) {
1398 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1399 0, 0);
1400 WARN_ON(ret); /* always succeed */
1401 }
1402 }
1403
1404 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1405 struct nilfs_segment_buffer *last,
1406 struct inode *sufile)
1407 {
1408 struct nilfs_segment_buffer *segbuf = last;
1409 int ret;
1410
1411 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1412 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1413 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1414 WARN_ON(ret);
1415 }
1416 nilfs_truncate_logs(&sci->sc_segbufs, last);
1417 }
1418
1419
1420 static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1421 struct the_nilfs *nilfs, int mode)
1422 {
1423 struct nilfs_cstage prev_stage = sci->sc_stage;
1424 int err, nadd = 1;
1425
1426 /* Collection retry loop */
1427 for (;;) {
1428 sci->sc_nblk_this_inc = 0;
1429 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1430
1431 err = nilfs_segctor_reset_segment_buffer(sci);
1432 if (unlikely(err))
1433 goto failed;
1434
1435 err = nilfs_segctor_collect_blocks(sci, mode);
1436 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1437 if (!err)
1438 break;
1439
1440 if (unlikely(err != -E2BIG))
1441 goto failed;
1442
1443 /* The current segment is filled up */
1444 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
1445 break;
1446
1447 nilfs_clear_logs(&sci->sc_segbufs);
1448
1449 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1450 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1451 sci->sc_freesegs,
1452 sci->sc_nfreesegs,
1453 NULL);
1454 WARN_ON(err); /* do not happen */
1455 sci->sc_stage.flags &= ~NILFS_CF_SUFREED;
1456 }
1457
1458 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1459 if (unlikely(err))
1460 return err;
1461
1462 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1463 sci->sc_stage = prev_stage;
1464 }
1465 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1466 return 0;
1467
1468 failed:
1469 return err;
1470 }
1471
1472 static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1473 struct buffer_head *new_bh)
1474 {
1475 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1476
1477 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1478 /* The caller must release old_bh */
1479 }
1480
1481 static int
1482 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1483 struct nilfs_segment_buffer *segbuf,
1484 int mode)
1485 {
1486 struct inode *inode = NULL;
1487 sector_t blocknr;
1488 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1489 unsigned long nblocks = 0, ndatablk = 0;
1490 struct nilfs_sc_operations *sc_op = NULL;
1491 struct nilfs_segsum_pointer ssp;
1492 struct nilfs_finfo *finfo = NULL;
1493 union nilfs_binfo binfo;
1494 struct buffer_head *bh, *bh_org;
1495 ino_t ino = 0;
1496 int err = 0;
1497
1498 if (!nfinfo)
1499 goto out;
1500
1501 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1502 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1503 ssp.offset = sizeof(struct nilfs_segment_summary);
1504
1505 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1506 if (bh == segbuf->sb_super_root)
1507 break;
1508 if (!finfo) {
1509 finfo = nilfs_segctor_map_segsum_entry(
1510 sci, &ssp, sizeof(*finfo));
1511 ino = le64_to_cpu(finfo->fi_ino);
1512 nblocks = le32_to_cpu(finfo->fi_nblocks);
1513 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1514
1515 inode = bh->b_page->mapping->host;
1516
1517 if (mode == SC_LSEG_DSYNC)
1518 sc_op = &nilfs_sc_dsync_ops;
1519 else if (ino == NILFS_DAT_INO)
1520 sc_op = &nilfs_sc_dat_ops;
1521 else /* file blocks */
1522 sc_op = &nilfs_sc_file_ops;
1523 }
1524 bh_org = bh;
1525 get_bh(bh_org);
1526 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1527 &binfo);
1528 if (bh != bh_org)
1529 nilfs_list_replace_buffer(bh_org, bh);
1530 brelse(bh_org);
1531 if (unlikely(err))
1532 goto failed_bmap;
1533
1534 if (ndatablk > 0)
1535 sc_op->write_data_binfo(sci, &ssp, &binfo);
1536 else
1537 sc_op->write_node_binfo(sci, &ssp, &binfo);
1538
1539 blocknr++;
1540 if (--nblocks == 0) {
1541 finfo = NULL;
1542 if (--nfinfo == 0)
1543 break;
1544 } else if (ndatablk > 0)
1545 ndatablk--;
1546 }
1547 out:
1548 return 0;
1549
1550 failed_bmap:
1551 return err;
1552 }
1553
1554 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1555 {
1556 struct nilfs_segment_buffer *segbuf;
1557 int err;
1558
1559 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1560 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1561 if (unlikely(err))
1562 return err;
1563 nilfs_segbuf_fill_in_segsum(segbuf);
1564 }
1565 return 0;
1566 }
1567
1568 static void nilfs_begin_page_io(struct page *page)
1569 {
1570 if (!page || PageWriteback(page))
1571 /* For split b-tree node pages, this function may be called
1572 twice. We ignore the 2nd or later calls by this check. */
1573 return;
1574
1575 lock_page(page);
1576 clear_page_dirty_for_io(page);
1577 set_page_writeback(page);
1578 unlock_page(page);
1579 }
1580
1581 static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
1582 {
1583 struct nilfs_segment_buffer *segbuf;
1584 struct page *bd_page = NULL, *fs_page = NULL;
1585
1586 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1587 struct buffer_head *bh;
1588
1589 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1590 b_assoc_buffers) {
1591 set_buffer_async_write(bh);
1592 if (bh->b_page != bd_page) {
1593 if (bd_page) {
1594 lock_page(bd_page);
1595 clear_page_dirty_for_io(bd_page);
1596 set_page_writeback(bd_page);
1597 unlock_page(bd_page);
1598 }
1599 bd_page = bh->b_page;
1600 }
1601 }
1602
1603 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1604 b_assoc_buffers) {
1605 set_buffer_async_write(bh);
1606 if (bh == segbuf->sb_super_root) {
1607 if (bh->b_page != bd_page) {
1608 lock_page(bd_page);
1609 clear_page_dirty_for_io(bd_page);
1610 set_page_writeback(bd_page);
1611 unlock_page(bd_page);
1612 bd_page = bh->b_page;
1613 }
1614 break;
1615 }
1616 if (bh->b_page != fs_page) {
1617 nilfs_begin_page_io(fs_page);
1618 fs_page = bh->b_page;
1619 }
1620 }
1621 }
1622 if (bd_page) {
1623 lock_page(bd_page);
1624 clear_page_dirty_for_io(bd_page);
1625 set_page_writeback(bd_page);
1626 unlock_page(bd_page);
1627 }
1628 nilfs_begin_page_io(fs_page);
1629 }
1630
1631 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1632 struct the_nilfs *nilfs)
1633 {
1634 int ret;
1635
1636 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1637 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1638 return ret;
1639 }
1640
1641 static void nilfs_end_page_io(struct page *page, int err)
1642 {
1643 if (!page)
1644 return;
1645
1646 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
1647 /*
1648 * For b-tree node pages, this function may be called twice
1649 * or more because they might be split in a segment.
1650 */
1651 if (PageDirty(page)) {
1652 /*
1653 * For pages holding split b-tree node buffers, dirty
1654 * flag on the buffers may be cleared discretely.
1655 * In that case, the page is once redirtied for
1656 * remaining buffers, and it must be cancelled if
1657 * all the buffers get cleaned later.
1658 */
1659 lock_page(page);
1660 if (nilfs_page_buffers_clean(page))
1661 __nilfs_clear_page_dirty(page);
1662 unlock_page(page);
1663 }
1664 return;
1665 }
1666
1667 if (!err) {
1668 if (!nilfs_page_buffers_clean(page))
1669 __set_page_dirty_nobuffers(page);
1670 ClearPageError(page);
1671 } else {
1672 __set_page_dirty_nobuffers(page);
1673 SetPageError(page);
1674 }
1675
1676 end_page_writeback(page);
1677 }
1678
1679 static void nilfs_abort_logs(struct list_head *logs, int err)
1680 {
1681 struct nilfs_segment_buffer *segbuf;
1682 struct page *bd_page = NULL, *fs_page = NULL;
1683 struct buffer_head *bh;
1684
1685 if (list_empty(logs))
1686 return;
1687
1688 list_for_each_entry(segbuf, logs, sb_list) {
1689 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1690 b_assoc_buffers) {
1691 clear_buffer_async_write(bh);
1692 if (bh->b_page != bd_page) {
1693 if (bd_page)
1694 end_page_writeback(bd_page);
1695 bd_page = bh->b_page;
1696 }
1697 }
1698
1699 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1700 b_assoc_buffers) {
1701 clear_buffer_async_write(bh);
1702 if (bh == segbuf->sb_super_root) {
1703 if (bh->b_page != bd_page) {
1704 end_page_writeback(bd_page);
1705 bd_page = bh->b_page;
1706 }
1707 break;
1708 }
1709 if (bh->b_page != fs_page) {
1710 nilfs_end_page_io(fs_page, err);
1711 fs_page = bh->b_page;
1712 }
1713 }
1714 }
1715 if (bd_page)
1716 end_page_writeback(bd_page);
1717
1718 nilfs_end_page_io(fs_page, err);
1719 }
1720
1721 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1722 struct the_nilfs *nilfs, int err)
1723 {
1724 LIST_HEAD(logs);
1725 int ret;
1726
1727 list_splice_tail_init(&sci->sc_write_logs, &logs);
1728 ret = nilfs_wait_on_logs(&logs);
1729 nilfs_abort_logs(&logs, ret ? : err);
1730
1731 list_splice_tail_init(&sci->sc_segbufs, &logs);
1732 nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1733 nilfs_free_incomplete_logs(&logs, nilfs);
1734
1735 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1736 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1737 sci->sc_freesegs,
1738 sci->sc_nfreesegs,
1739 NULL);
1740 WARN_ON(ret); /* do not happen */
1741 }
1742
1743 nilfs_destroy_logs(&logs);
1744 }
1745
1746 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1747 struct nilfs_segment_buffer *segbuf)
1748 {
1749 nilfs->ns_segnum = segbuf->sb_segnum;
1750 nilfs->ns_nextnum = segbuf->sb_nextnum;
1751 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1752 + segbuf->sb_sum.nblocks;
1753 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1754 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1755 }
1756
1757 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1758 {
1759 struct nilfs_segment_buffer *segbuf;
1760 struct page *bd_page = NULL, *fs_page = NULL;
1761 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1762 int update_sr = false;
1763
1764 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1765 struct buffer_head *bh;
1766
1767 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1768 b_assoc_buffers) {
1769 set_buffer_uptodate(bh);
1770 clear_buffer_dirty(bh);
1771 clear_buffer_async_write(bh);
1772 if (bh->b_page != bd_page) {
1773 if (bd_page)
1774 end_page_writeback(bd_page);
1775 bd_page = bh->b_page;
1776 }
1777 }
1778 /*
1779 * We assume that the buffers which belong to the same page
1780 * continue over the buffer list.
1781 * Under this assumption, the last BHs of pages is
1782 * identifiable by the discontinuity of bh->b_page
1783 * (page != fs_page).
1784 *
1785 * For B-tree node blocks, however, this assumption is not
1786 * guaranteed. The cleanup code of B-tree node pages needs
1787 * special care.
1788 */
1789 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1790 b_assoc_buffers) {
1791 set_buffer_uptodate(bh);
1792 clear_buffer_dirty(bh);
1793 clear_buffer_async_write(bh);
1794 clear_buffer_delay(bh);
1795 clear_buffer_nilfs_volatile(bh);
1796 clear_buffer_nilfs_redirected(bh);
1797 if (bh == segbuf->sb_super_root) {
1798 if (bh->b_page != bd_page) {
1799 end_page_writeback(bd_page);
1800 bd_page = bh->b_page;
1801 }
1802 update_sr = true;
1803 break;
1804 }
1805 if (bh->b_page != fs_page) {
1806 nilfs_end_page_io(fs_page, 0);
1807 fs_page = bh->b_page;
1808 }
1809 }
1810
1811 if (!nilfs_segbuf_simplex(segbuf)) {
1812 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
1813 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1814 sci->sc_lseg_stime = jiffies;
1815 }
1816 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
1817 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1818 }
1819 }
1820 /*
1821 * Since pages may continue over multiple segment buffers,
1822 * end of the last page must be checked outside of the loop.
1823 */
1824 if (bd_page)
1825 end_page_writeback(bd_page);
1826
1827 nilfs_end_page_io(fs_page, 0);
1828
1829 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1830
1831 if (nilfs_doing_gc())
1832 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1833 else
1834 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1835
1836 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1837
1838 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1839 nilfs_set_next_segment(nilfs, segbuf);
1840
1841 if (update_sr) {
1842 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
1843 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
1844
1845 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
1846 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1847 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1848 nilfs_segctor_clear_metadata_dirty(sci);
1849 } else
1850 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1851 }
1852
1853 static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
1854 {
1855 int ret;
1856
1857 ret = nilfs_wait_on_logs(&sci->sc_write_logs);
1858 if (!ret) {
1859 nilfs_segctor_complete_write(sci);
1860 nilfs_destroy_logs(&sci->sc_write_logs);
1861 }
1862 return ret;
1863 }
1864
1865 static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci,
1866 struct the_nilfs *nilfs)
1867 {
1868 struct nilfs_inode_info *ii, *n;
1869 struct inode *ifile = sci->sc_root->ifile;
1870
1871 spin_lock(&nilfs->ns_inode_lock);
1872 retry:
1873 list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) {
1874 if (!ii->i_bh) {
1875 struct buffer_head *ibh;
1876 int err;
1877
1878 spin_unlock(&nilfs->ns_inode_lock);
1879 err = nilfs_ifile_get_inode_block(
1880 ifile, ii->vfs_inode.i_ino, &ibh);
1881 if (unlikely(err)) {
1882 nilfs_warning(sci->sc_super, __func__,
1883 "failed to get inode block.\n");
1884 return err;
1885 }
1886 mark_buffer_dirty(ibh);
1887 nilfs_mdt_mark_dirty(ifile);
1888 spin_lock(&nilfs->ns_inode_lock);
1889 if (likely(!ii->i_bh))
1890 ii->i_bh = ibh;
1891 else
1892 brelse(ibh);
1893 goto retry;
1894 }
1895
1896 clear_bit(NILFS_I_QUEUED, &ii->i_state);
1897 set_bit(NILFS_I_BUSY, &ii->i_state);
1898 list_move_tail(&ii->i_dirty, &sci->sc_dirty_files);
1899 }
1900 spin_unlock(&nilfs->ns_inode_lock);
1901
1902 return 0;
1903 }
1904
1905 static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
1906 struct the_nilfs *nilfs)
1907 {
1908 struct nilfs_inode_info *ii, *n;
1909 int defer_iput = false;
1910
1911 spin_lock(&nilfs->ns_inode_lock);
1912 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
1913 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
1914 test_bit(NILFS_I_DIRTY, &ii->i_state))
1915 continue;
1916
1917 clear_bit(NILFS_I_BUSY, &ii->i_state);
1918 brelse(ii->i_bh);
1919 ii->i_bh = NULL;
1920 list_del_init(&ii->i_dirty);
1921 if (!ii->vfs_inode.i_nlink) {
1922 /*
1923 * Defer calling iput() to avoid a deadlock
1924 * over I_SYNC flag for inodes with i_nlink == 0
1925 */
1926 list_add_tail(&ii->i_dirty, &sci->sc_iput_queue);
1927 defer_iput = true;
1928 } else {
1929 spin_unlock(&nilfs->ns_inode_lock);
1930 iput(&ii->vfs_inode);
1931 spin_lock(&nilfs->ns_inode_lock);
1932 }
1933 }
1934 spin_unlock(&nilfs->ns_inode_lock);
1935
1936 if (defer_iput)
1937 schedule_work(&sci->sc_iput_work);
1938 }
1939
1940 /*
1941 * Main procedure of segment constructor
1942 */
1943 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
1944 {
1945 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1946 int err;
1947
1948 sci->sc_stage.scnt = NILFS_ST_INIT;
1949 sci->sc_cno = nilfs->ns_cno;
1950
1951 err = nilfs_segctor_collect_dirty_files(sci, nilfs);
1952 if (unlikely(err))
1953 goto out;
1954
1955 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
1956 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1957
1958 if (nilfs_segctor_clean(sci))
1959 goto out;
1960
1961 do {
1962 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
1963
1964 err = nilfs_segctor_begin_construction(sci, nilfs);
1965 if (unlikely(err))
1966 goto out;
1967
1968 /* Update time stamp */
1969 sci->sc_seg_ctime = get_seconds();
1970
1971 err = nilfs_segctor_collect(sci, nilfs, mode);
1972 if (unlikely(err))
1973 goto failed;
1974
1975 /* Avoid empty segment */
1976 if (sci->sc_stage.scnt == NILFS_ST_DONE &&
1977 nilfs_segbuf_empty(sci->sc_curseg)) {
1978 nilfs_segctor_abort_construction(sci, nilfs, 1);
1979 goto out;
1980 }
1981
1982 err = nilfs_segctor_assign(sci, mode);
1983 if (unlikely(err))
1984 goto failed;
1985
1986 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
1987 nilfs_segctor_fill_in_file_bmap(sci);
1988
1989 if (mode == SC_LSEG_SR &&
1990 sci->sc_stage.scnt >= NILFS_ST_CPFILE) {
1991 err = nilfs_segctor_fill_in_checkpoint(sci);
1992 if (unlikely(err))
1993 goto failed_to_write;
1994
1995 nilfs_segctor_fill_in_super_root(sci, nilfs);
1996 }
1997 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
1998
1999 /* Write partial segments */
2000 nilfs_segctor_prepare_write(sci);
2001
2002 nilfs_add_checksums_on_logs(&sci->sc_segbufs,
2003 nilfs->ns_crc_seed);
2004
2005 err = nilfs_segctor_write(sci, nilfs);
2006 if (unlikely(err))
2007 goto failed_to_write;
2008
2009 if (sci->sc_stage.scnt == NILFS_ST_DONE ||
2010 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
2011 /*
2012 * At this point, we avoid double buffering
2013 * for blocksize < pagesize because page dirty
2014 * flag is turned off during write and dirty
2015 * buffers are not properly collected for
2016 * pages crossing over segments.
2017 */
2018 err = nilfs_segctor_wait(sci);
2019 if (err)
2020 goto failed_to_write;
2021 }
2022 } while (sci->sc_stage.scnt != NILFS_ST_DONE);
2023
2024 out:
2025 nilfs_segctor_drop_written_files(sci, nilfs);
2026 return err;
2027
2028 failed_to_write:
2029 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2030 nilfs_redirty_inodes(&sci->sc_dirty_files);
2031
2032 failed:
2033 if (nilfs_doing_gc())
2034 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2035 nilfs_segctor_abort_construction(sci, nilfs, err);
2036 goto out;
2037 }
2038
2039 /**
2040 * nilfs_segctor_start_timer - set timer of background write
2041 * @sci: nilfs_sc_info
2042 *
2043 * If the timer has already been set, it ignores the new request.
2044 * This function MUST be called within a section locking the segment
2045 * semaphore.
2046 */
2047 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2048 {
2049 spin_lock(&sci->sc_state_lock);
2050 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2051 sci->sc_timer.expires = jiffies + sci->sc_interval;
2052 add_timer(&sci->sc_timer);
2053 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2054 }
2055 spin_unlock(&sci->sc_state_lock);
2056 }
2057
2058 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2059 {
2060 spin_lock(&sci->sc_state_lock);
2061 if (!(sci->sc_flush_request & (1 << bn))) {
2062 unsigned long prev_req = sci->sc_flush_request;
2063
2064 sci->sc_flush_request |= (1 << bn);
2065 if (!prev_req)
2066 wake_up(&sci->sc_wait_daemon);
2067 }
2068 spin_unlock(&sci->sc_state_lock);
2069 }
2070
2071 /**
2072 * nilfs_flush_segment - trigger a segment construction for resource control
2073 * @sb: super block
2074 * @ino: inode number of the file to be flushed out.
2075 */
2076 void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2077 {
2078 struct the_nilfs *nilfs = sb->s_fs_info;
2079 struct nilfs_sc_info *sci = nilfs->ns_writer;
2080
2081 if (!sci || nilfs_doing_construction())
2082 return;
2083 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2084 /* assign bit 0 to data files */
2085 }
2086
2087 struct nilfs_segctor_wait_request {
2088 wait_queue_t wq;
2089 __u32 seq;
2090 int err;
2091 atomic_t done;
2092 };
2093
2094 static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2095 {
2096 struct nilfs_segctor_wait_request wait_req;
2097 int err = 0;
2098
2099 spin_lock(&sci->sc_state_lock);
2100 init_wait(&wait_req.wq);
2101 wait_req.err = 0;
2102 atomic_set(&wait_req.done, 0);
2103 wait_req.seq = ++sci->sc_seq_request;
2104 spin_unlock(&sci->sc_state_lock);
2105
2106 init_waitqueue_entry(&wait_req.wq, current);
2107 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2108 set_current_state(TASK_INTERRUPTIBLE);
2109 wake_up(&sci->sc_wait_daemon);
2110
2111 for (;;) {
2112 if (atomic_read(&wait_req.done)) {
2113 err = wait_req.err;
2114 break;
2115 }
2116 if (!signal_pending(current)) {
2117 schedule();
2118 continue;
2119 }
2120 err = -ERESTARTSYS;
2121 break;
2122 }
2123 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2124 return err;
2125 }
2126
2127 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2128 {
2129 struct nilfs_segctor_wait_request *wrq, *n;
2130 unsigned long flags;
2131
2132 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2133 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2134 wq.task_list) {
2135 if (!atomic_read(&wrq->done) &&
2136 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2137 wrq->err = err;
2138 atomic_set(&wrq->done, 1);
2139 }
2140 if (atomic_read(&wrq->done)) {
2141 wrq->wq.func(&wrq->wq,
2142 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2143 0, NULL);
2144 }
2145 }
2146 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2147 }
2148
2149 /**
2150 * nilfs_construct_segment - construct a logical segment
2151 * @sb: super block
2152 *
2153 * Return Value: On success, 0 is retured. On errors, one of the following
2154 * negative error code is returned.
2155 *
2156 * %-EROFS - Read only filesystem.
2157 *
2158 * %-EIO - I/O error
2159 *
2160 * %-ENOSPC - No space left on device (only in a panic state).
2161 *
2162 * %-ERESTARTSYS - Interrupted.
2163 *
2164 * %-ENOMEM - Insufficient memory available.
2165 */
2166 int nilfs_construct_segment(struct super_block *sb)
2167 {
2168 struct the_nilfs *nilfs = sb->s_fs_info;
2169 struct nilfs_sc_info *sci = nilfs->ns_writer;
2170 struct nilfs_transaction_info *ti;
2171 int err;
2172
2173 if (!sci)
2174 return -EROFS;
2175
2176 /* A call inside transactions causes a deadlock. */
2177 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2178
2179 err = nilfs_segctor_sync(sci);
2180 return err;
2181 }
2182
2183 /**
2184 * nilfs_construct_dsync_segment - construct a data-only logical segment
2185 * @sb: super block
2186 * @inode: inode whose data blocks should be written out
2187 * @start: start byte offset
2188 * @end: end byte offset (inclusive)
2189 *
2190 * Return Value: On success, 0 is retured. On errors, one of the following
2191 * negative error code is returned.
2192 *
2193 * %-EROFS - Read only filesystem.
2194 *
2195 * %-EIO - I/O error
2196 *
2197 * %-ENOSPC - No space left on device (only in a panic state).
2198 *
2199 * %-ERESTARTSYS - Interrupted.
2200 *
2201 * %-ENOMEM - Insufficient memory available.
2202 */
2203 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2204 loff_t start, loff_t end)
2205 {
2206 struct the_nilfs *nilfs = sb->s_fs_info;
2207 struct nilfs_sc_info *sci = nilfs->ns_writer;
2208 struct nilfs_inode_info *ii;
2209 struct nilfs_transaction_info ti;
2210 int err = 0;
2211
2212 if (!sci)
2213 return -EROFS;
2214
2215 nilfs_transaction_lock(sb, &ti, 0);
2216
2217 ii = NILFS_I(inode);
2218 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
2219 nilfs_test_opt(nilfs, STRICT_ORDER) ||
2220 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2221 nilfs_discontinued(nilfs)) {
2222 nilfs_transaction_unlock(sb);
2223 err = nilfs_segctor_sync(sci);
2224 return err;
2225 }
2226
2227 spin_lock(&nilfs->ns_inode_lock);
2228 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2229 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2230 spin_unlock(&nilfs->ns_inode_lock);
2231 nilfs_transaction_unlock(sb);
2232 return 0;
2233 }
2234 spin_unlock(&nilfs->ns_inode_lock);
2235 sci->sc_dsync_inode = ii;
2236 sci->sc_dsync_start = start;
2237 sci->sc_dsync_end = end;
2238
2239 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2240
2241 nilfs_transaction_unlock(sb);
2242 return err;
2243 }
2244
2245 #define FLUSH_FILE_BIT (0x1) /* data file only */
2246 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2247
2248 /**
2249 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2250 * @sci: segment constructor object
2251 */
2252 static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2253 {
2254 spin_lock(&sci->sc_state_lock);
2255 sci->sc_seq_accepted = sci->sc_seq_request;
2256 spin_unlock(&sci->sc_state_lock);
2257 del_timer_sync(&sci->sc_timer);
2258 }
2259
2260 /**
2261 * nilfs_segctor_notify - notify the result of request to caller threads
2262 * @sci: segment constructor object
2263 * @mode: mode of log forming
2264 * @err: error code to be notified
2265 */
2266 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2267 {
2268 /* Clear requests (even when the construction failed) */
2269 spin_lock(&sci->sc_state_lock);
2270
2271 if (mode == SC_LSEG_SR) {
2272 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2273 sci->sc_seq_done = sci->sc_seq_accepted;
2274 nilfs_segctor_wakeup(sci, err);
2275 sci->sc_flush_request = 0;
2276 } else {
2277 if (mode == SC_FLUSH_FILE)
2278 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2279 else if (mode == SC_FLUSH_DAT)
2280 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2281
2282 /* re-enable timer if checkpoint creation was not done */
2283 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2284 time_before(jiffies, sci->sc_timer.expires))
2285 add_timer(&sci->sc_timer);
2286 }
2287 spin_unlock(&sci->sc_state_lock);
2288 }
2289
2290 /**
2291 * nilfs_segctor_construct - form logs and write them to disk
2292 * @sci: segment constructor object
2293 * @mode: mode of log forming
2294 */
2295 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2296 {
2297 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2298 struct nilfs_super_block **sbp;
2299 int err = 0;
2300
2301 nilfs_segctor_accept(sci);
2302
2303 if (nilfs_discontinued(nilfs))
2304 mode = SC_LSEG_SR;
2305 if (!nilfs_segctor_confirm(sci))
2306 err = nilfs_segctor_do_construct(sci, mode);
2307
2308 if (likely(!err)) {
2309 if (mode != SC_FLUSH_DAT)
2310 atomic_set(&nilfs->ns_ndirtyblks, 0);
2311 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2312 nilfs_discontinued(nilfs)) {
2313 down_write(&nilfs->ns_sem);
2314 err = -EIO;
2315 sbp = nilfs_prepare_super(sci->sc_super,
2316 nilfs_sb_will_flip(nilfs));
2317 if (likely(sbp)) {
2318 nilfs_set_log_cursor(sbp[0], nilfs);
2319 err = nilfs_commit_super(sci->sc_super,
2320 NILFS_SB_COMMIT);
2321 }
2322 up_write(&nilfs->ns_sem);
2323 }
2324 }
2325
2326 nilfs_segctor_notify(sci, mode, err);
2327 return err;
2328 }
2329
2330 static void nilfs_construction_timeout(unsigned long data)
2331 {
2332 struct task_struct *p = (struct task_struct *)data;
2333 wake_up_process(p);
2334 }
2335
2336 static void
2337 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2338 {
2339 struct nilfs_inode_info *ii, *n;
2340
2341 list_for_each_entry_safe(ii, n, head, i_dirty) {
2342 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2343 continue;
2344 list_del_init(&ii->i_dirty);
2345 truncate_inode_pages(&ii->vfs_inode.i_data, 0);
2346 nilfs_btnode_cache_clear(&ii->i_btnode_cache);
2347 iput(&ii->vfs_inode);
2348 }
2349 }
2350
2351 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2352 void **kbufs)
2353 {
2354 struct the_nilfs *nilfs = sb->s_fs_info;
2355 struct nilfs_sc_info *sci = nilfs->ns_writer;
2356 struct nilfs_transaction_info ti;
2357 int err;
2358
2359 if (unlikely(!sci))
2360 return -EROFS;
2361
2362 nilfs_transaction_lock(sb, &ti, 1);
2363
2364 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2365 if (unlikely(err))
2366 goto out_unlock;
2367
2368 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2369 if (unlikely(err)) {
2370 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2371 goto out_unlock;
2372 }
2373
2374 sci->sc_freesegs = kbufs[4];
2375 sci->sc_nfreesegs = argv[4].v_nmembs;
2376 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2377
2378 for (;;) {
2379 err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2380 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2381
2382 if (likely(!err))
2383 break;
2384
2385 nilfs_warning(sb, __func__,
2386 "segment construction failed. (err=%d)", err);
2387 set_current_state(TASK_INTERRUPTIBLE);
2388 schedule_timeout(sci->sc_interval);
2389 }
2390 if (nilfs_test_opt(nilfs, DISCARD)) {
2391 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2392 sci->sc_nfreesegs);
2393 if (ret) {
2394 printk(KERN_WARNING
2395 "NILFS warning: error %d on discard request, "
2396 "turning discards off for the device\n", ret);
2397 nilfs_clear_opt(nilfs, DISCARD);
2398 }
2399 }
2400
2401 out_unlock:
2402 sci->sc_freesegs = NULL;
2403 sci->sc_nfreesegs = 0;
2404 nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2405 nilfs_transaction_unlock(sb);
2406 return err;
2407 }
2408
2409 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2410 {
2411 struct nilfs_transaction_info ti;
2412
2413 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2414 nilfs_segctor_construct(sci, mode);
2415
2416 /*
2417 * Unclosed segment should be retried. We do this using sc_timer.
2418 * Timeout of sc_timer will invoke complete construction which leads
2419 * to close the current logical segment.
2420 */
2421 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2422 nilfs_segctor_start_timer(sci);
2423
2424 nilfs_transaction_unlock(sci->sc_super);
2425 }
2426
2427 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2428 {
2429 int mode = 0;
2430 int err;
2431
2432 spin_lock(&sci->sc_state_lock);
2433 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2434 SC_FLUSH_DAT : SC_FLUSH_FILE;
2435 spin_unlock(&sci->sc_state_lock);
2436
2437 if (mode) {
2438 err = nilfs_segctor_do_construct(sci, mode);
2439
2440 spin_lock(&sci->sc_state_lock);
2441 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2442 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2443 spin_unlock(&sci->sc_state_lock);
2444 }
2445 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2446 }
2447
2448 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2449 {
2450 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2451 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2452 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2453 return SC_FLUSH_FILE;
2454 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2455 return SC_FLUSH_DAT;
2456 }
2457 return SC_LSEG_SR;
2458 }
2459
2460 /**
2461 * nilfs_segctor_thread - main loop of the segment constructor thread.
2462 * @arg: pointer to a struct nilfs_sc_info.
2463 *
2464 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2465 * to execute segment constructions.
2466 */
2467 static int nilfs_segctor_thread(void *arg)
2468 {
2469 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2470 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2471 int timeout = 0;
2472
2473 set_freezable();
2474
2475 sci->sc_timer.data = (unsigned long)current;
2476 sci->sc_timer.function = nilfs_construction_timeout;
2477
2478 /* start sync. */
2479 sci->sc_task = current;
2480 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2481 printk(KERN_INFO
2482 "segctord starting. Construction interval = %lu seconds, "
2483 "CP frequency < %lu seconds\n",
2484 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2485
2486 spin_lock(&sci->sc_state_lock);
2487 loop:
2488 for (;;) {
2489 int mode;
2490
2491 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2492 goto end_thread;
2493
2494 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2495 mode = SC_LSEG_SR;
2496 else if (!sci->sc_flush_request)
2497 break;
2498 else
2499 mode = nilfs_segctor_flush_mode(sci);
2500
2501 spin_unlock(&sci->sc_state_lock);
2502 nilfs_segctor_thread_construct(sci, mode);
2503 spin_lock(&sci->sc_state_lock);
2504 timeout = 0;
2505 }
2506
2507
2508 if (freezing(current)) {
2509 spin_unlock(&sci->sc_state_lock);
2510 try_to_freeze();
2511 spin_lock(&sci->sc_state_lock);
2512 } else {
2513 DEFINE_WAIT(wait);
2514 int should_sleep = 1;
2515
2516 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2517 TASK_INTERRUPTIBLE);
2518
2519 if (sci->sc_seq_request != sci->sc_seq_done)
2520 should_sleep = 0;
2521 else if (sci->sc_flush_request)
2522 should_sleep = 0;
2523 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2524 should_sleep = time_before(jiffies,
2525 sci->sc_timer.expires);
2526
2527 if (should_sleep) {
2528 spin_unlock(&sci->sc_state_lock);
2529 schedule();
2530 spin_lock(&sci->sc_state_lock);
2531 }
2532 finish_wait(&sci->sc_wait_daemon, &wait);
2533 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2534 time_after_eq(jiffies, sci->sc_timer.expires));
2535
2536 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2537 set_nilfs_discontinued(nilfs);
2538 }
2539 goto loop;
2540
2541 end_thread:
2542 spin_unlock(&sci->sc_state_lock);
2543
2544 /* end sync. */
2545 sci->sc_task = NULL;
2546 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2547 return 0;
2548 }
2549
2550 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2551 {
2552 struct task_struct *t;
2553
2554 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2555 if (IS_ERR(t)) {
2556 int err = PTR_ERR(t);
2557
2558 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2559 err);
2560 return err;
2561 }
2562 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2563 return 0;
2564 }
2565
2566 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2567 __acquires(&sci->sc_state_lock)
2568 __releases(&sci->sc_state_lock)
2569 {
2570 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2571
2572 while (sci->sc_task) {
2573 wake_up(&sci->sc_wait_daemon);
2574 spin_unlock(&sci->sc_state_lock);
2575 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2576 spin_lock(&sci->sc_state_lock);
2577 }
2578 }
2579
2580 /*
2581 * Setup & clean-up functions
2582 */
2583 static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
2584 struct nilfs_root *root)
2585 {
2586 struct the_nilfs *nilfs = sb->s_fs_info;
2587 struct nilfs_sc_info *sci;
2588
2589 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2590 if (!sci)
2591 return NULL;
2592
2593 sci->sc_super = sb;
2594
2595 nilfs_get_root(root);
2596 sci->sc_root = root;
2597
2598 init_waitqueue_head(&sci->sc_wait_request);
2599 init_waitqueue_head(&sci->sc_wait_daemon);
2600 init_waitqueue_head(&sci->sc_wait_task);
2601 spin_lock_init(&sci->sc_state_lock);
2602 INIT_LIST_HEAD(&sci->sc_dirty_files);
2603 INIT_LIST_HEAD(&sci->sc_segbufs);
2604 INIT_LIST_HEAD(&sci->sc_write_logs);
2605 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2606 INIT_LIST_HEAD(&sci->sc_iput_queue);
2607 INIT_WORK(&sci->sc_iput_work, nilfs_iput_work_func);
2608 init_timer(&sci->sc_timer);
2609
2610 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2611 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2612 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2613
2614 if (nilfs->ns_interval)
2615 sci->sc_interval = HZ * nilfs->ns_interval;
2616 if (nilfs->ns_watermark)
2617 sci->sc_watermark = nilfs->ns_watermark;
2618 return sci;
2619 }
2620
2621 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2622 {
2623 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2624
2625 /* The segctord thread was stopped and its timer was removed.
2626 But some tasks remain. */
2627 do {
2628 struct nilfs_transaction_info ti;
2629
2630 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2631 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2632 nilfs_transaction_unlock(sci->sc_super);
2633
2634 flush_work(&sci->sc_iput_work);
2635
2636 } while (ret && retrycount-- > 0);
2637 }
2638
2639 /**
2640 * nilfs_segctor_destroy - destroy the segment constructor.
2641 * @sci: nilfs_sc_info
2642 *
2643 * nilfs_segctor_destroy() kills the segctord thread and frees
2644 * the nilfs_sc_info struct.
2645 * Caller must hold the segment semaphore.
2646 */
2647 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2648 {
2649 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2650 int flag;
2651
2652 up_write(&nilfs->ns_segctor_sem);
2653
2654 spin_lock(&sci->sc_state_lock);
2655 nilfs_segctor_kill_thread(sci);
2656 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2657 || sci->sc_seq_request != sci->sc_seq_done);
2658 spin_unlock(&sci->sc_state_lock);
2659
2660 if (flush_work(&sci->sc_iput_work))
2661 flag = true;
2662
2663 if (flag || !nilfs_segctor_confirm(sci))
2664 nilfs_segctor_write_out(sci);
2665
2666 if (!list_empty(&sci->sc_dirty_files)) {
2667 nilfs_warning(sci->sc_super, __func__,
2668 "dirty file(s) after the final construction\n");
2669 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
2670 }
2671
2672 if (!list_empty(&sci->sc_iput_queue)) {
2673 nilfs_warning(sci->sc_super, __func__,
2674 "iput queue is not empty\n");
2675 nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 1);
2676 }
2677
2678 WARN_ON(!list_empty(&sci->sc_segbufs));
2679 WARN_ON(!list_empty(&sci->sc_write_logs));
2680
2681 nilfs_put_root(sci->sc_root);
2682
2683 down_write(&nilfs->ns_segctor_sem);
2684
2685 del_timer_sync(&sci->sc_timer);
2686 kfree(sci);
2687 }
2688
2689 /**
2690 * nilfs_attach_log_writer - attach log writer
2691 * @sb: super block instance
2692 * @root: root object of the current filesystem tree
2693 *
2694 * This allocates a log writer object, initializes it, and starts the
2695 * log writer.
2696 *
2697 * Return Value: On success, 0 is returned. On error, one of the following
2698 * negative error code is returned.
2699 *
2700 * %-ENOMEM - Insufficient memory available.
2701 */
2702 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
2703 {
2704 struct the_nilfs *nilfs = sb->s_fs_info;
2705 int err;
2706
2707 if (nilfs->ns_writer) {
2708 /*
2709 * This happens if the filesystem was remounted
2710 * read/write after nilfs_error degenerated it into a
2711 * read-only mount.
2712 */
2713 nilfs_detach_log_writer(sb);
2714 }
2715
2716 nilfs->ns_writer = nilfs_segctor_new(sb, root);
2717 if (!nilfs->ns_writer)
2718 return -ENOMEM;
2719
2720 err = nilfs_segctor_start_thread(nilfs->ns_writer);
2721 if (err) {
2722 kfree(nilfs->ns_writer);
2723 nilfs->ns_writer = NULL;
2724 }
2725 return err;
2726 }
2727
2728 /**
2729 * nilfs_detach_log_writer - destroy log writer
2730 * @sb: super block instance
2731 *
2732 * This kills log writer daemon, frees the log writer object, and
2733 * destroys list of dirty files.
2734 */
2735 void nilfs_detach_log_writer(struct super_block *sb)
2736 {
2737 struct the_nilfs *nilfs = sb->s_fs_info;
2738 LIST_HEAD(garbage_list);
2739
2740 down_write(&nilfs->ns_segctor_sem);
2741 if (nilfs->ns_writer) {
2742 nilfs_segctor_destroy(nilfs->ns_writer);
2743 nilfs->ns_writer = NULL;
2744 }
2745
2746 /* Force to free the list of dirty files */
2747 spin_lock(&nilfs->ns_inode_lock);
2748 if (!list_empty(&nilfs->ns_dirty_files)) {
2749 list_splice_init(&nilfs->ns_dirty_files, &garbage_list);
2750 nilfs_warning(sb, __func__,
2751 "Hit dirty file after stopped log writer\n");
2752 }
2753 spin_unlock(&nilfs->ns_inode_lock);
2754 up_write(&nilfs->ns_segctor_sem);
2755
2756 nilfs_dispose_list(nilfs, &garbage_list, 1);
2757 }
kernel source for telekom puls (alcatel/mediatek)