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Linux 4.2.1
[linux/fpc-iii.git] / fs / nilfs2 / segment.c
blobc6abbad9b8e3833d9cbbac60f648e786b600836f
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/bitops.h>
28 #include <linux/bio.h>
29 #include <linux/completion.h>
30 #include <linux/blkdev.h>
31 #include <linux/backing-dev.h>
32 #include <linux/freezer.h>
33 #include <linux/kthread.h>
34 #include <linux/crc32.h>
35 #include <linux/pagevec.h>
36 #include <linux/slab.h>
37 #include "nilfs.h"
38 #include "btnode.h"
39 #include "page.h"
40 #include "segment.h"
41 #include "sufile.h"
42 #include "cpfile.h"
43 #include "ifile.h"
44 #include "segbuf.h"
45
46
47 /*
48 * Segment constructor
49 */
50 #define SC_N_INODEVEC 16 /* Size of locally allocated inode vector */
51
52 #define SC_MAX_SEGDELTA 64 /* Upper limit of the number of segments
53 appended in collection retry loop */
54
55 /* Construction mode */
56 enum {
57 SC_LSEG_SR = 1, /* Make a logical segment having a super root */
58 SC_LSEG_DSYNC, /* Flush data blocks of a given file and make
59 a logical segment without a super root */
60 SC_FLUSH_FILE, /* Flush data files, leads to segment writes without
61 creating a checkpoint */
62 SC_FLUSH_DAT, /* Flush DAT file. This also creates segments without
63 a checkpoint */
64 };
65
66 /* Stage numbers of dirty block collection */
67 enum {
68 NILFS_ST_INIT = 0,
69 NILFS_ST_GC, /* Collecting dirty blocks for GC */
70 NILFS_ST_FILE,
71 NILFS_ST_IFILE,
72 NILFS_ST_CPFILE,
73 NILFS_ST_SUFILE,
74 NILFS_ST_DAT,
75 NILFS_ST_SR, /* Super root */
76 NILFS_ST_DSYNC, /* Data sync blocks */
77 NILFS_ST_DONE,
78 };
79
80 /* State flags of collection */
81 #define NILFS_CF_NODE 0x0001 /* Collecting node blocks */
82 #define NILFS_CF_IFILE_STARTED 0x0002 /* IFILE stage has started */
83 #define NILFS_CF_SUFREED 0x0004 /* segment usages has been freed */
84 #define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED)
85
86 /* Operations depending on the construction mode and file type */
87 struct nilfs_sc_operations {
88 int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *,
89 struct inode *);
90 int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *,
91 struct inode *);
92 int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *,
93 struct inode *);
94 void (*write_data_binfo)(struct nilfs_sc_info *,
95 struct nilfs_segsum_pointer *,
96 union nilfs_binfo *);
97 void (*write_node_binfo)(struct nilfs_sc_info *,
98 struct nilfs_segsum_pointer *,
99 union nilfs_binfo *);
100 };
101
102 /*
103 * Other definitions
104 */
105 static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
106 static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
107 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
108 static void nilfs_dispose_list(struct the_nilfs *, struct list_head *, int);
109
110 #define nilfs_cnt32_gt(a, b) \
111 (typecheck(__u32, a) && typecheck(__u32, b) && \
112 ((__s32)(b) - (__s32)(a) < 0))
113 #define nilfs_cnt32_ge(a, b) \
114 (typecheck(__u32, a) && typecheck(__u32, b) && \
115 ((__s32)(a) - (__s32)(b) >= 0))
116 #define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a)
117 #define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a)
118
119 static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
120 {
121 struct nilfs_transaction_info *cur_ti = current->journal_info;
122 void *save = NULL;
123
124 if (cur_ti) {
125 if (cur_ti->ti_magic == NILFS_TI_MAGIC)
126 return ++cur_ti->ti_count;
127 else {
128 /*
129 * If journal_info field is occupied by other FS,
130 * it is saved and will be restored on
131 * nilfs_transaction_commit().
132 */
133 printk(KERN_WARNING
134 "NILFS warning: journal info from a different "
135 "FS\n");
136 save = current->journal_info;
137 }
138 }
139 if (!ti) {
140 ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
141 if (!ti)
142 return -ENOMEM;
143 ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
144 } else {
145 ti->ti_flags = 0;
146 }
147 ti->ti_count = 0;
148 ti->ti_save = save;
149 ti->ti_magic = NILFS_TI_MAGIC;
150 current->journal_info = ti;
151 return 0;
152 }
153
154 /**
155 * nilfs_transaction_begin - start indivisible file operations.
156 * @sb: super block
157 * @ti: nilfs_transaction_info
158 * @vacancy_check: flags for vacancy rate checks
159 *
160 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
161 * the segment semaphore, to make a segment construction and write tasks
162 * exclusive. The function is used with nilfs_transaction_commit() in pairs.
163 * The region enclosed by these two functions can be nested. To avoid a
164 * deadlock, the semaphore is only acquired or released in the outermost call.
165 *
166 * This function allocates a nilfs_transaction_info struct to keep context
167 * information on it. It is initialized and hooked onto the current task in
168 * the outermost call. If a pre-allocated struct is given to @ti, it is used
169 * instead; otherwise a new struct is assigned from a slab.
170 *
171 * When @vacancy_check flag is set, this function will check the amount of
172 * free space, and will wait for the GC to reclaim disk space if low capacity.
173 *
174 * Return Value: On success, 0 is returned. On error, one of the following
175 * negative error code is returned.
176 *
177 * %-ENOMEM - Insufficient memory available.
178 *
179 * %-ENOSPC - No space left on device
180 */
181 int nilfs_transaction_begin(struct super_block *sb,
182 struct nilfs_transaction_info *ti,
183 int vacancy_check)
184 {
185 struct the_nilfs *nilfs;
186 int ret = nilfs_prepare_segment_lock(ti);
187
188 if (unlikely(ret < 0))
189 return ret;
190 if (ret > 0)
191 return 0;
192
193 sb_start_intwrite(sb);
194
195 nilfs = sb->s_fs_info;
196 down_read(&nilfs->ns_segctor_sem);
197 if (vacancy_check && nilfs_near_disk_full(nilfs)) {
198 up_read(&nilfs->ns_segctor_sem);
199 ret = -ENOSPC;
200 goto failed;
201 }
202 return 0;
203
204 failed:
205 ti = current->journal_info;
206 current->journal_info = ti->ti_save;
207 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
208 kmem_cache_free(nilfs_transaction_cachep, ti);
209 sb_end_intwrite(sb);
210 return ret;
211 }
212
213 /**
214 * nilfs_transaction_commit - commit indivisible file operations.
215 * @sb: super block
216 *
217 * nilfs_transaction_commit() releases the read semaphore which is
218 * acquired by nilfs_transaction_begin(). This is only performed
219 * in outermost call of this function. If a commit flag is set,
220 * nilfs_transaction_commit() sets a timer to start the segment
221 * constructor. If a sync flag is set, it starts construction
222 * directly.
223 */
224 int nilfs_transaction_commit(struct super_block *sb)
225 {
226 struct nilfs_transaction_info *ti = current->journal_info;
227 struct the_nilfs *nilfs = sb->s_fs_info;
228 int err = 0;
229
230 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
231 ti->ti_flags |= NILFS_TI_COMMIT;
232 if (ti->ti_count > 0) {
233 ti->ti_count--;
234 return 0;
235 }
236 if (nilfs->ns_writer) {
237 struct nilfs_sc_info *sci = nilfs->ns_writer;
238
239 if (ti->ti_flags & NILFS_TI_COMMIT)
240 nilfs_segctor_start_timer(sci);
241 if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark)
242 nilfs_segctor_do_flush(sci, 0);
243 }
244 up_read(&nilfs->ns_segctor_sem);
245 current->journal_info = ti->ti_save;
246
247 if (ti->ti_flags & NILFS_TI_SYNC)
248 err = nilfs_construct_segment(sb);
249 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
250 kmem_cache_free(nilfs_transaction_cachep, ti);
251 sb_end_intwrite(sb);
252 return err;
253 }
254
255 void nilfs_transaction_abort(struct super_block *sb)
256 {
257 struct nilfs_transaction_info *ti = current->journal_info;
258 struct the_nilfs *nilfs = sb->s_fs_info;
259
260 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
261 if (ti->ti_count > 0) {
262 ti->ti_count--;
263 return;
264 }
265 up_read(&nilfs->ns_segctor_sem);
266
267 current->journal_info = ti->ti_save;
268 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
269 kmem_cache_free(nilfs_transaction_cachep, ti);
270 sb_end_intwrite(sb);
271 }
272
273 void nilfs_relax_pressure_in_lock(struct super_block *sb)
274 {
275 struct the_nilfs *nilfs = sb->s_fs_info;
276 struct nilfs_sc_info *sci = nilfs->ns_writer;
277
278 if (!sci || !sci->sc_flush_request)
279 return;
280
281 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
282 up_read(&nilfs->ns_segctor_sem);
283
284 down_write(&nilfs->ns_segctor_sem);
285 if (sci->sc_flush_request &&
286 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
287 struct nilfs_transaction_info *ti = current->journal_info;
288
289 ti->ti_flags |= NILFS_TI_WRITER;
290 nilfs_segctor_do_immediate_flush(sci);
291 ti->ti_flags &= ~NILFS_TI_WRITER;
292 }
293 downgrade_write(&nilfs->ns_segctor_sem);
294 }
295
296 static void nilfs_transaction_lock(struct super_block *sb,
297 struct nilfs_transaction_info *ti,
298 int gcflag)
299 {
300 struct nilfs_transaction_info *cur_ti = current->journal_info;
301 struct the_nilfs *nilfs = sb->s_fs_info;
302 struct nilfs_sc_info *sci = nilfs->ns_writer;
303
304 WARN_ON(cur_ti);
305 ti->ti_flags = NILFS_TI_WRITER;
306 ti->ti_count = 0;
307 ti->ti_save = cur_ti;
308 ti->ti_magic = NILFS_TI_MAGIC;
309 current->journal_info = ti;
310
311 for (;;) {
312 down_write(&nilfs->ns_segctor_sem);
313 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags))
314 break;
315
316 nilfs_segctor_do_immediate_flush(sci);
317
318 up_write(&nilfs->ns_segctor_sem);
319 yield();
320 }
321 if (gcflag)
322 ti->ti_flags |= NILFS_TI_GC;
323 }
324
325 static void nilfs_transaction_unlock(struct super_block *sb)
326 {
327 struct nilfs_transaction_info *ti = current->journal_info;
328 struct the_nilfs *nilfs = sb->s_fs_info;
329
330 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
331 BUG_ON(ti->ti_count > 0);
332
333 up_write(&nilfs->ns_segctor_sem);
334 current->journal_info = ti->ti_save;
335 }
336
337 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
338 struct nilfs_segsum_pointer *ssp,
339 unsigned bytes)
340 {
341 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
342 unsigned blocksize = sci->sc_super->s_blocksize;
343 void *p;
344
345 if (unlikely(ssp->offset + bytes > blocksize)) {
346 ssp->offset = 0;
347 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
348 &segbuf->sb_segsum_buffers));
349 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
350 }
351 p = ssp->bh->b_data + ssp->offset;
352 ssp->offset += bytes;
353 return p;
354 }
355
356 /**
357 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
358 * @sci: nilfs_sc_info
359 */
360 static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
361 {
362 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
363 struct buffer_head *sumbh;
364 unsigned sumbytes;
365 unsigned flags = 0;
366 int err;
367
368 if (nilfs_doing_gc())
369 flags = NILFS_SS_GC;
370 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno);
371 if (unlikely(err))
372 return err;
373
374 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
375 sumbytes = segbuf->sb_sum.sumbytes;
376 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
377 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
378 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
379 return 0;
380 }
381
382 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
383 {
384 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
385 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
386 return -E2BIG; /* The current segment is filled up
387 (internal code) */
388 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
389 return nilfs_segctor_reset_segment_buffer(sci);
390 }
391
392 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
393 {
394 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
395 int err;
396
397 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
398 err = nilfs_segctor_feed_segment(sci);
399 if (err)
400 return err;
401 segbuf = sci->sc_curseg;
402 }
403 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root);
404 if (likely(!err))
405 segbuf->sb_sum.flags |= NILFS_SS_SR;
406 return err;
407 }
408
409 /*
410 * Functions for making segment summary and payloads
411 */
412 static int nilfs_segctor_segsum_block_required(
413 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
414 unsigned binfo_size)
415 {
416 unsigned blocksize = sci->sc_super->s_blocksize;
417 /* Size of finfo and binfo is enough small against blocksize */
418
419 return ssp->offset + binfo_size +
420 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
421 blocksize;
422 }
423
424 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
425 struct inode *inode)
426 {
427 sci->sc_curseg->sb_sum.nfinfo++;
428 sci->sc_binfo_ptr = sci->sc_finfo_ptr;
429 nilfs_segctor_map_segsum_entry(
430 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
431
432 if (NILFS_I(inode)->i_root &&
433 !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
434 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
435 /* skip finfo */
436 }
437
438 static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
439 struct inode *inode)
440 {
441 struct nilfs_finfo *finfo;
442 struct nilfs_inode_info *ii;
443 struct nilfs_segment_buffer *segbuf;
444 __u64 cno;
445
446 if (sci->sc_blk_cnt == 0)
447 return;
448
449 ii = NILFS_I(inode);
450
451 if (test_bit(NILFS_I_GCINODE, &ii->i_state))
452 cno = ii->i_cno;
453 else if (NILFS_ROOT_METADATA_FILE(inode->i_ino))
454 cno = 0;
455 else
456 cno = sci->sc_cno;
457
458 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
459 sizeof(*finfo));
460 finfo->fi_ino = cpu_to_le64(inode->i_ino);
461 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
462 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
463 finfo->fi_cno = cpu_to_le64(cno);
464
465 segbuf = sci->sc_curseg;
466 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
467 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
468 sci->sc_finfo_ptr = sci->sc_binfo_ptr;
469 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
470 }
471
472 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
473 struct buffer_head *bh,
474 struct inode *inode,
475 unsigned binfo_size)
476 {
477 struct nilfs_segment_buffer *segbuf;
478 int required, err = 0;
479
480 retry:
481 segbuf = sci->sc_curseg;
482 required = nilfs_segctor_segsum_block_required(
483 sci, &sci->sc_binfo_ptr, binfo_size);
484 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
485 nilfs_segctor_end_finfo(sci, inode);
486 err = nilfs_segctor_feed_segment(sci);
487 if (err)
488 return err;
489 goto retry;
490 }
491 if (unlikely(required)) {
492 err = nilfs_segbuf_extend_segsum(segbuf);
493 if (unlikely(err))
494 goto failed;
495 }
496 if (sci->sc_blk_cnt == 0)
497 nilfs_segctor_begin_finfo(sci, inode);
498
499 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
500 /* Substitution to vblocknr is delayed until update_blocknr() */
501 nilfs_segbuf_add_file_buffer(segbuf, bh);
502 sci->sc_blk_cnt++;
503 failed:
504 return err;
505 }
506
507 /*
508 * Callback functions that enumerate, mark, and collect dirty blocks
509 */
510 static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
511 struct buffer_head *bh, struct inode *inode)
512 {
513 int err;
514
515 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
516 if (err < 0)
517 return err;
518
519 err = nilfs_segctor_add_file_block(sci, bh, inode,
520 sizeof(struct nilfs_binfo_v));
521 if (!err)
522 sci->sc_datablk_cnt++;
523 return err;
524 }
525
526 static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
527 struct buffer_head *bh,
528 struct inode *inode)
529 {
530 return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
531 }
532
533 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
534 struct buffer_head *bh,
535 struct inode *inode)
536 {
537 WARN_ON(!buffer_dirty(bh));
538 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
539 }
540
541 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
542 struct nilfs_segsum_pointer *ssp,
543 union nilfs_binfo *binfo)
544 {
545 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
546 sci, ssp, sizeof(*binfo_v));
547 *binfo_v = binfo->bi_v;
548 }
549
550 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
551 struct nilfs_segsum_pointer *ssp,
552 union nilfs_binfo *binfo)
553 {
554 __le64 *vblocknr = nilfs_segctor_map_segsum_entry(
555 sci, ssp, sizeof(*vblocknr));
556 *vblocknr = binfo->bi_v.bi_vblocknr;
557 }
558
559 static struct nilfs_sc_operations nilfs_sc_file_ops = {
560 .collect_data = nilfs_collect_file_data,
561 .collect_node = nilfs_collect_file_node,
562 .collect_bmap = nilfs_collect_file_bmap,
563 .write_data_binfo = nilfs_write_file_data_binfo,
564 .write_node_binfo = nilfs_write_file_node_binfo,
565 };
566
567 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
568 struct buffer_head *bh, struct inode *inode)
569 {
570 int err;
571
572 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
573 if (err < 0)
574 return err;
575
576 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
577 if (!err)
578 sci->sc_datablk_cnt++;
579 return err;
580 }
581
582 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
583 struct buffer_head *bh, struct inode *inode)
584 {
585 WARN_ON(!buffer_dirty(bh));
586 return nilfs_segctor_add_file_block(sci, bh, inode,
587 sizeof(struct nilfs_binfo_dat));
588 }
589
590 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
591 struct nilfs_segsum_pointer *ssp,
592 union nilfs_binfo *binfo)
593 {
594 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
595 sizeof(*blkoff));
596 *blkoff = binfo->bi_dat.bi_blkoff;
597 }
598
599 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
600 struct nilfs_segsum_pointer *ssp,
601 union nilfs_binfo *binfo)
602 {
603 struct nilfs_binfo_dat *binfo_dat =
604 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
605 *binfo_dat = binfo->bi_dat;
606 }
607
608 static struct nilfs_sc_operations nilfs_sc_dat_ops = {
609 .collect_data = nilfs_collect_dat_data,
610 .collect_node = nilfs_collect_file_node,
611 .collect_bmap = nilfs_collect_dat_bmap,
612 .write_data_binfo = nilfs_write_dat_data_binfo,
613 .write_node_binfo = nilfs_write_dat_node_binfo,
614 };
615
616 static struct nilfs_sc_operations nilfs_sc_dsync_ops = {
617 .collect_data = nilfs_collect_file_data,
618 .collect_node = NULL,
619 .collect_bmap = NULL,
620 .write_data_binfo = nilfs_write_file_data_binfo,
621 .write_node_binfo = NULL,
622 };
623
624 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
625 struct list_head *listp,
626 size_t nlimit,
627 loff_t start, loff_t end)
628 {
629 struct address_space *mapping = inode->i_mapping;
630 struct pagevec pvec;
631 pgoff_t index = 0, last = ULONG_MAX;
632 size_t ndirties = 0;
633 int i;
634
635 if (unlikely(start != 0 || end != LLONG_MAX)) {
636 /*
637 * A valid range is given for sync-ing data pages. The
638 * range is rounded to per-page; extra dirty buffers
639 * may be included if blocksize < pagesize.
640 */
641 index = start >> PAGE_SHIFT;
642 last = end >> PAGE_SHIFT;
643 }
644 pagevec_init(&pvec, 0);
645 repeat:
646 if (unlikely(index > last) ||
647 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
648 min_t(pgoff_t, last - index,
649 PAGEVEC_SIZE - 1) + 1))
650 return ndirties;
651
652 for (i = 0; i < pagevec_count(&pvec); i++) {
653 struct buffer_head *bh, *head;
654 struct page *page = pvec.pages[i];
655
656 if (unlikely(page->index > last))
657 break;
658
659 lock_page(page);
660 if (!page_has_buffers(page))
661 create_empty_buffers(page, 1 << inode->i_blkbits, 0);
662 unlock_page(page);
663
664 bh = head = page_buffers(page);
665 do {
666 if (!buffer_dirty(bh) || buffer_async_write(bh))
667 continue;
668 get_bh(bh);
669 list_add_tail(&bh->b_assoc_buffers, listp);
670 ndirties++;
671 if (unlikely(ndirties >= nlimit)) {
672 pagevec_release(&pvec);
673 cond_resched();
674 return ndirties;
675 }
676 } while (bh = bh->b_this_page, bh != head);
677 }
678 pagevec_release(&pvec);
679 cond_resched();
680 goto repeat;
681 }
682
683 static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
684 struct list_head *listp)
685 {
686 struct nilfs_inode_info *ii = NILFS_I(inode);
687 struct address_space *mapping = &ii->i_btnode_cache;
688 struct pagevec pvec;
689 struct buffer_head *bh, *head;
690 unsigned int i;
691 pgoff_t index = 0;
692
693 pagevec_init(&pvec, 0);
694
695 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
696 PAGEVEC_SIZE)) {
697 for (i = 0; i < pagevec_count(&pvec); i++) {
698 bh = head = page_buffers(pvec.pages[i]);
699 do {
700 if (buffer_dirty(bh) &&
701 !buffer_async_write(bh)) {
702 get_bh(bh);
703 list_add_tail(&bh->b_assoc_buffers,
704 listp);
705 }
706 bh = bh->b_this_page;
707 } while (bh != head);
708 }
709 pagevec_release(&pvec);
710 cond_resched();
711 }
712 }
713
714 static void nilfs_dispose_list(struct the_nilfs *nilfs,
715 struct list_head *head, int force)
716 {
717 struct nilfs_inode_info *ii, *n;
718 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
719 unsigned nv = 0;
720
721 while (!list_empty(head)) {
722 spin_lock(&nilfs->ns_inode_lock);
723 list_for_each_entry_safe(ii, n, head, i_dirty) {
724 list_del_init(&ii->i_dirty);
725 if (force) {
726 if (unlikely(ii->i_bh)) {
727 brelse(ii->i_bh);
728 ii->i_bh = NULL;
729 }
730 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
731 set_bit(NILFS_I_QUEUED, &ii->i_state);
732 list_add_tail(&ii->i_dirty,
733 &nilfs->ns_dirty_files);
734 continue;
735 }
736 ivec[nv++] = ii;
737 if (nv == SC_N_INODEVEC)
738 break;
739 }
740 spin_unlock(&nilfs->ns_inode_lock);
741
742 for (pii = ivec; nv > 0; pii++, nv--)
743 iput(&(*pii)->vfs_inode);
744 }
745 }
746
747 static void nilfs_iput_work_func(struct work_struct *work)
748 {
749 struct nilfs_sc_info *sci = container_of(work, struct nilfs_sc_info,
750 sc_iput_work);
751 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
752
753 nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 0);
754 }
755
756 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
757 struct nilfs_root *root)
758 {
759 int ret = 0;
760
761 if (nilfs_mdt_fetch_dirty(root->ifile))
762 ret++;
763 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
764 ret++;
765 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
766 ret++;
767 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat))
768 ret++;
769 return ret;
770 }
771
772 static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
773 {
774 return list_empty(&sci->sc_dirty_files) &&
775 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
776 sci->sc_nfreesegs == 0 &&
777 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
778 }
779
780 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
781 {
782 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
783 int ret = 0;
784
785 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
786 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
787
788 spin_lock(&nilfs->ns_inode_lock);
789 if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci))
790 ret++;
791
792 spin_unlock(&nilfs->ns_inode_lock);
793 return ret;
794 }
795
796 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
797 {
798 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
799
800 nilfs_mdt_clear_dirty(sci->sc_root->ifile);
801 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
802 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
803 nilfs_mdt_clear_dirty(nilfs->ns_dat);
804 }
805
806 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
807 {
808 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
809 struct buffer_head *bh_cp;
810 struct nilfs_checkpoint *raw_cp;
811 int err;
812
813 /* XXX: this interface will be changed */
814 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
815 &raw_cp, &bh_cp);
816 if (likely(!err)) {
817 /* The following code is duplicated with cpfile. But, it is
818 needed to collect the checkpoint even if it was not newly
819 created */
820 mark_buffer_dirty(bh_cp);
821 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
822 nilfs_cpfile_put_checkpoint(
823 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
824 } else
825 WARN_ON(err == -EINVAL || err == -ENOENT);
826
827 return err;
828 }
829
830 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
831 {
832 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
833 struct buffer_head *bh_cp;
834 struct nilfs_checkpoint *raw_cp;
835 int err;
836
837 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
838 &raw_cp, &bh_cp);
839 if (unlikely(err)) {
840 WARN_ON(err == -EINVAL || err == -ENOENT);
841 goto failed_ibh;
842 }
843 raw_cp->cp_snapshot_list.ssl_next = 0;
844 raw_cp->cp_snapshot_list.ssl_prev = 0;
845 raw_cp->cp_inodes_count =
846 cpu_to_le64(atomic64_read(&sci->sc_root->inodes_count));
847 raw_cp->cp_blocks_count =
848 cpu_to_le64(atomic64_read(&sci->sc_root->blocks_count));
849 raw_cp->cp_nblk_inc =
850 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
851 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
852 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
853
854 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
855 nilfs_checkpoint_clear_minor(raw_cp);
856 else
857 nilfs_checkpoint_set_minor(raw_cp);
858
859 nilfs_write_inode_common(sci->sc_root->ifile,
860 &raw_cp->cp_ifile_inode, 1);
861 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
862 return 0;
863
864 failed_ibh:
865 return err;
866 }
867
868 static void nilfs_fill_in_file_bmap(struct inode *ifile,
869 struct nilfs_inode_info *ii)
870
871 {
872 struct buffer_head *ibh;
873 struct nilfs_inode *raw_inode;
874
875 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
876 ibh = ii->i_bh;
877 BUG_ON(!ibh);
878 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
879 ibh);
880 nilfs_bmap_write(ii->i_bmap, raw_inode);
881 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
882 }
883 }
884
885 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
886 {
887 struct nilfs_inode_info *ii;
888
889 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
890 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
891 set_bit(NILFS_I_COLLECTED, &ii->i_state);
892 }
893 }
894
895 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
896 struct the_nilfs *nilfs)
897 {
898 struct buffer_head *bh_sr;
899 struct nilfs_super_root *raw_sr;
900 unsigned isz, srsz;
901
902 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
903 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
904 isz = nilfs->ns_inode_size;
905 srsz = NILFS_SR_BYTES(isz);
906
907 raw_sr->sr_bytes = cpu_to_le16(srsz);
908 raw_sr->sr_nongc_ctime
909 = cpu_to_le64(nilfs_doing_gc() ?
910 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
911 raw_sr->sr_flags = 0;
912
913 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr +
914 NILFS_SR_DAT_OFFSET(isz), 1);
915 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
916 NILFS_SR_CPFILE_OFFSET(isz), 1);
917 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
918 NILFS_SR_SUFILE_OFFSET(isz), 1);
919 memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz);
920 }
921
922 static void nilfs_redirty_inodes(struct list_head *head)
923 {
924 struct nilfs_inode_info *ii;
925
926 list_for_each_entry(ii, head, i_dirty) {
927 if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
928 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
929 }
930 }
931
932 static void nilfs_drop_collected_inodes(struct list_head *head)
933 {
934 struct nilfs_inode_info *ii;
935
936 list_for_each_entry(ii, head, i_dirty) {
937 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
938 continue;
939
940 clear_bit(NILFS_I_INODE_SYNC, &ii->i_state);
941 set_bit(NILFS_I_UPDATED, &ii->i_state);
942 }
943 }
944
945 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
946 struct inode *inode,
947 struct list_head *listp,
948 int (*collect)(struct nilfs_sc_info *,
949 struct buffer_head *,
950 struct inode *))
951 {
952 struct buffer_head *bh, *n;
953 int err = 0;
954
955 if (collect) {
956 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
957 list_del_init(&bh->b_assoc_buffers);
958 err = collect(sci, bh, inode);
959 brelse(bh);
960 if (unlikely(err))
961 goto dispose_buffers;
962 }
963 return 0;
964 }
965
966 dispose_buffers:
967 while (!list_empty(listp)) {
968 bh = list_first_entry(listp, struct buffer_head,
969 b_assoc_buffers);
970 list_del_init(&bh->b_assoc_buffers);
971 brelse(bh);
972 }
973 return err;
974 }
975
976 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
977 {
978 /* Remaining number of blocks within segment buffer */
979 return sci->sc_segbuf_nblocks -
980 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
981 }
982
983 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
984 struct inode *inode,
985 struct nilfs_sc_operations *sc_ops)
986 {
987 LIST_HEAD(data_buffers);
988 LIST_HEAD(node_buffers);
989 int err;
990
991 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
992 size_t n, rest = nilfs_segctor_buffer_rest(sci);
993
994 n = nilfs_lookup_dirty_data_buffers(
995 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
996 if (n > rest) {
997 err = nilfs_segctor_apply_buffers(
998 sci, inode, &data_buffers,
999 sc_ops->collect_data);
1000 BUG_ON(!err); /* always receive -E2BIG or true error */
1001 goto break_or_fail;
1002 }
1003 }
1004 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
1005
1006 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1007 err = nilfs_segctor_apply_buffers(
1008 sci, inode, &data_buffers, sc_ops->collect_data);
1009 if (unlikely(err)) {
1010 /* dispose node list */
1011 nilfs_segctor_apply_buffers(
1012 sci, inode, &node_buffers, NULL);
1013 goto break_or_fail;
1014 }
1015 sci->sc_stage.flags |= NILFS_CF_NODE;
1016 }
1017 /* Collect node */
1018 err = nilfs_segctor_apply_buffers(
1019 sci, inode, &node_buffers, sc_ops->collect_node);
1020 if (unlikely(err))
1021 goto break_or_fail;
1022
1023 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1024 err = nilfs_segctor_apply_buffers(
1025 sci, inode, &node_buffers, sc_ops->collect_bmap);
1026 if (unlikely(err))
1027 goto break_or_fail;
1028
1029 nilfs_segctor_end_finfo(sci, inode);
1030 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1031
1032 break_or_fail:
1033 return err;
1034 }
1035
1036 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1037 struct inode *inode)
1038 {
1039 LIST_HEAD(data_buffers);
1040 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1041 int err;
1042
1043 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1044 sci->sc_dsync_start,
1045 sci->sc_dsync_end);
1046
1047 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1048 nilfs_collect_file_data);
1049 if (!err) {
1050 nilfs_segctor_end_finfo(sci, inode);
1051 BUG_ON(n > rest);
1052 /* always receive -E2BIG or true error if n > rest */
1053 }
1054 return err;
1055 }
1056
1057 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1058 {
1059 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1060 struct list_head *head;
1061 struct nilfs_inode_info *ii;
1062 size_t ndone;
1063 int err = 0;
1064
1065 switch (sci->sc_stage.scnt) {
1066 case NILFS_ST_INIT:
1067 /* Pre-processes */
1068 sci->sc_stage.flags = 0;
1069
1070 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1071 sci->sc_nblk_inc = 0;
1072 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1073 if (mode == SC_LSEG_DSYNC) {
1074 sci->sc_stage.scnt = NILFS_ST_DSYNC;
1075 goto dsync_mode;
1076 }
1077 }
1078
1079 sci->sc_stage.dirty_file_ptr = NULL;
1080 sci->sc_stage.gc_inode_ptr = NULL;
1081 if (mode == SC_FLUSH_DAT) {
1082 sci->sc_stage.scnt = NILFS_ST_DAT;
1083 goto dat_stage;
1084 }
1085 sci->sc_stage.scnt++; /* Fall through */
1086 case NILFS_ST_GC:
1087 if (nilfs_doing_gc()) {
1088 head = &sci->sc_gc_inodes;
1089 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1090 head, i_dirty);
1091 list_for_each_entry_continue(ii, head, i_dirty) {
1092 err = nilfs_segctor_scan_file(
1093 sci, &ii->vfs_inode,
1094 &nilfs_sc_file_ops);
1095 if (unlikely(err)) {
1096 sci->sc_stage.gc_inode_ptr = list_entry(
1097 ii->i_dirty.prev,
1098 struct nilfs_inode_info,
1099 i_dirty);
1100 goto break_or_fail;
1101 }
1102 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1103 }
1104 sci->sc_stage.gc_inode_ptr = NULL;
1105 }
1106 sci->sc_stage.scnt++; /* Fall through */
1107 case NILFS_ST_FILE:
1108 head = &sci->sc_dirty_files;
1109 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1110 i_dirty);
1111 list_for_each_entry_continue(ii, head, i_dirty) {
1112 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1113
1114 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1115 &nilfs_sc_file_ops);
1116 if (unlikely(err)) {
1117 sci->sc_stage.dirty_file_ptr =
1118 list_entry(ii->i_dirty.prev,
1119 struct nilfs_inode_info,
1120 i_dirty);
1121 goto break_or_fail;
1122 }
1123 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1124 /* XXX: required ? */
1125 }
1126 sci->sc_stage.dirty_file_ptr = NULL;
1127 if (mode == SC_FLUSH_FILE) {
1128 sci->sc_stage.scnt = NILFS_ST_DONE;
1129 return 0;
1130 }
1131 sci->sc_stage.scnt++;
1132 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1133 /* Fall through */
1134 case NILFS_ST_IFILE:
1135 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile,
1136 &nilfs_sc_file_ops);
1137 if (unlikely(err))
1138 break;
1139 sci->sc_stage.scnt++;
1140 /* Creating a checkpoint */
1141 err = nilfs_segctor_create_checkpoint(sci);
1142 if (unlikely(err))
1143 break;
1144 /* Fall through */
1145 case NILFS_ST_CPFILE:
1146 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1147 &nilfs_sc_file_ops);
1148 if (unlikely(err))
1149 break;
1150 sci->sc_stage.scnt++; /* Fall through */
1151 case NILFS_ST_SUFILE:
1152 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1153 sci->sc_nfreesegs, &ndone);
1154 if (unlikely(err)) {
1155 nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1156 sci->sc_freesegs, ndone,
1157 NULL);
1158 break;
1159 }
1160 sci->sc_stage.flags |= NILFS_CF_SUFREED;
1161
1162 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1163 &nilfs_sc_file_ops);
1164 if (unlikely(err))
1165 break;
1166 sci->sc_stage.scnt++; /* Fall through */
1167 case NILFS_ST_DAT:
1168 dat_stage:
1169 err = nilfs_segctor_scan_file(sci, nilfs->ns_dat,
1170 &nilfs_sc_dat_ops);
1171 if (unlikely(err))
1172 break;
1173 if (mode == SC_FLUSH_DAT) {
1174 sci->sc_stage.scnt = NILFS_ST_DONE;
1175 return 0;
1176 }
1177 sci->sc_stage.scnt++; /* Fall through */
1178 case NILFS_ST_SR:
1179 if (mode == SC_LSEG_SR) {
1180 /* Appending a super root */
1181 err = nilfs_segctor_add_super_root(sci);
1182 if (unlikely(err))
1183 break;
1184 }
1185 /* End of a logical segment */
1186 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1187 sci->sc_stage.scnt = NILFS_ST_DONE;
1188 return 0;
1189 case NILFS_ST_DSYNC:
1190 dsync_mode:
1191 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1192 ii = sci->sc_dsync_inode;
1193 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1194 break;
1195
1196 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1197 if (unlikely(err))
1198 break;
1199 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1200 sci->sc_stage.scnt = NILFS_ST_DONE;
1201 return 0;
1202 case NILFS_ST_DONE:
1203 return 0;
1204 default:
1205 BUG();
1206 }
1207
1208 break_or_fail:
1209 return err;
1210 }
1211
1212 /**
1213 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1214 * @sci: nilfs_sc_info
1215 * @nilfs: nilfs object
1216 */
1217 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1218 struct the_nilfs *nilfs)
1219 {
1220 struct nilfs_segment_buffer *segbuf, *prev;
1221 __u64 nextnum;
1222 int err, alloc = 0;
1223
1224 segbuf = nilfs_segbuf_new(sci->sc_super);
1225 if (unlikely(!segbuf))
1226 return -ENOMEM;
1227
1228 if (list_empty(&sci->sc_write_logs)) {
1229 nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1230 nilfs->ns_pseg_offset, nilfs);
1231 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1232 nilfs_shift_to_next_segment(nilfs);
1233 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1234 }
1235
1236 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1237 nextnum = nilfs->ns_nextnum;
1238
1239 if (nilfs->ns_segnum == nilfs->ns_nextnum)
1240 /* Start from the head of a new full segment */
1241 alloc++;
1242 } else {
1243 /* Continue logs */
1244 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1245 nilfs_segbuf_map_cont(segbuf, prev);
1246 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1247 nextnum = prev->sb_nextnum;
1248
1249 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1250 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1251 segbuf->sb_sum.seg_seq++;
1252 alloc++;
1253 }
1254 }
1255
1256 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1257 if (err)
1258 goto failed;
1259
1260 if (alloc) {
1261 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1262 if (err)
1263 goto failed;
1264 }
1265 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1266
1267 BUG_ON(!list_empty(&sci->sc_segbufs));
1268 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1269 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1270 return 0;
1271
1272 failed:
1273 nilfs_segbuf_free(segbuf);
1274 return err;
1275 }
1276
1277 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1278 struct the_nilfs *nilfs, int nadd)
1279 {
1280 struct nilfs_segment_buffer *segbuf, *prev;
1281 struct inode *sufile = nilfs->ns_sufile;
1282 __u64 nextnextnum;
1283 LIST_HEAD(list);
1284 int err, ret, i;
1285
1286 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1287 /*
1288 * Since the segment specified with nextnum might be allocated during
1289 * the previous construction, the buffer including its segusage may
1290 * not be dirty. The following call ensures that the buffer is dirty
1291 * and will pin the buffer on memory until the sufile is written.
1292 */
1293 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1294 if (unlikely(err))
1295 return err;
1296
1297 for (i = 0; i < nadd; i++) {
1298 /* extend segment info */
1299 err = -ENOMEM;
1300 segbuf = nilfs_segbuf_new(sci->sc_super);
1301 if (unlikely(!segbuf))
1302 goto failed;
1303
1304 /* map this buffer to region of segment on-disk */
1305 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1306 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1307
1308 /* allocate the next next full segment */
1309 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1310 if (unlikely(err))
1311 goto failed_segbuf;
1312
1313 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1314 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1315
1316 list_add_tail(&segbuf->sb_list, &list);
1317 prev = segbuf;
1318 }
1319 list_splice_tail(&list, &sci->sc_segbufs);
1320 return 0;
1321
1322 failed_segbuf:
1323 nilfs_segbuf_free(segbuf);
1324 failed:
1325 list_for_each_entry(segbuf, &list, sb_list) {
1326 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1327 WARN_ON(ret); /* never fails */
1328 }
1329 nilfs_destroy_logs(&list);
1330 return err;
1331 }
1332
1333 static void nilfs_free_incomplete_logs(struct list_head *logs,
1334 struct the_nilfs *nilfs)
1335 {
1336 struct nilfs_segment_buffer *segbuf, *prev;
1337 struct inode *sufile = nilfs->ns_sufile;
1338 int ret;
1339
1340 segbuf = NILFS_FIRST_SEGBUF(logs);
1341 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1342 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1343 WARN_ON(ret); /* never fails */
1344 }
1345 if (atomic_read(&segbuf->sb_err)) {
1346 /* Case 1: The first segment failed */
1347 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1348 /* Case 1a: Partial segment appended into an existing
1349 segment */
1350 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1351 segbuf->sb_fseg_end);
1352 else /* Case 1b: New full segment */
1353 set_nilfs_discontinued(nilfs);
1354 }
1355
1356 prev = segbuf;
1357 list_for_each_entry_continue(segbuf, logs, sb_list) {
1358 if (prev->sb_nextnum != segbuf->sb_nextnum) {
1359 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1360 WARN_ON(ret); /* never fails */
1361 }
1362 if (atomic_read(&segbuf->sb_err) &&
1363 segbuf->sb_segnum != nilfs->ns_nextnum)
1364 /* Case 2: extended segment (!= next) failed */
1365 nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1366 prev = segbuf;
1367 }
1368 }
1369
1370 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1371 struct inode *sufile)
1372 {
1373 struct nilfs_segment_buffer *segbuf;
1374 unsigned long live_blocks;
1375 int ret;
1376
1377 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1378 live_blocks = segbuf->sb_sum.nblocks +
1379 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1380 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1381 live_blocks,
1382 sci->sc_seg_ctime);
1383 WARN_ON(ret); /* always succeed because the segusage is dirty */
1384 }
1385 }
1386
1387 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1388 {
1389 struct nilfs_segment_buffer *segbuf;
1390 int ret;
1391
1392 segbuf = NILFS_FIRST_SEGBUF(logs);
1393 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1394 segbuf->sb_pseg_start -
1395 segbuf->sb_fseg_start, 0);
1396 WARN_ON(ret); /* always succeed because the segusage is dirty */
1397
1398 list_for_each_entry_continue(segbuf, logs, sb_list) {
1399 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1400 0, 0);
1401 WARN_ON(ret); /* always succeed */
1402 }
1403 }
1404
1405 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1406 struct nilfs_segment_buffer *last,
1407 struct inode *sufile)
1408 {
1409 struct nilfs_segment_buffer *segbuf = last;
1410 int ret;
1411
1412 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1413 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1414 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1415 WARN_ON(ret);
1416 }
1417 nilfs_truncate_logs(&sci->sc_segbufs, last);
1418 }
1419
1420
1421 static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1422 struct the_nilfs *nilfs, int mode)
1423 {
1424 struct nilfs_cstage prev_stage = sci->sc_stage;
1425 int err, nadd = 1;
1426
1427 /* Collection retry loop */
1428 for (;;) {
1429 sci->sc_nblk_this_inc = 0;
1430 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1431
1432 err = nilfs_segctor_reset_segment_buffer(sci);
1433 if (unlikely(err))
1434 goto failed;
1435
1436 err = nilfs_segctor_collect_blocks(sci, mode);
1437 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1438 if (!err)
1439 break;
1440
1441 if (unlikely(err != -E2BIG))
1442 goto failed;
1443
1444 /* The current segment is filled up */
1445 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
1446 break;
1447
1448 nilfs_clear_logs(&sci->sc_segbufs);
1449
1450 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1451 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1452 sci->sc_freesegs,
1453 sci->sc_nfreesegs,
1454 NULL);
1455 WARN_ON(err); /* do not happen */
1456 sci->sc_stage.flags &= ~NILFS_CF_SUFREED;
1457 }
1458
1459 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1460 if (unlikely(err))
1461 return err;
1462
1463 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1464 sci->sc_stage = prev_stage;
1465 }
1466 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1467 return 0;
1468
1469 failed:
1470 return err;
1471 }
1472
1473 static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1474 struct buffer_head *new_bh)
1475 {
1476 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1477
1478 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1479 /* The caller must release old_bh */
1480 }
1481
1482 static int
1483 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1484 struct nilfs_segment_buffer *segbuf,
1485 int mode)
1486 {
1487 struct inode *inode = NULL;
1488 sector_t blocknr;
1489 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1490 unsigned long nblocks = 0, ndatablk = 0;
1491 struct nilfs_sc_operations *sc_op = NULL;
1492 struct nilfs_segsum_pointer ssp;
1493 struct nilfs_finfo *finfo = NULL;
1494 union nilfs_binfo binfo;
1495 struct buffer_head *bh, *bh_org;
1496 ino_t ino = 0;
1497 int err = 0;
1498
1499 if (!nfinfo)
1500 goto out;
1501
1502 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1503 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1504 ssp.offset = sizeof(struct nilfs_segment_summary);
1505
1506 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1507 if (bh == segbuf->sb_super_root)
1508 break;
1509 if (!finfo) {
1510 finfo = nilfs_segctor_map_segsum_entry(
1511 sci, &ssp, sizeof(*finfo));
1512 ino = le64_to_cpu(finfo->fi_ino);
1513 nblocks = le32_to_cpu(finfo->fi_nblocks);
1514 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1515
1516 inode = bh->b_page->mapping->host;
1517
1518 if (mode == SC_LSEG_DSYNC)
1519 sc_op = &nilfs_sc_dsync_ops;
1520 else if (ino == NILFS_DAT_INO)
1521 sc_op = &nilfs_sc_dat_ops;
1522 else /* file blocks */
1523 sc_op = &nilfs_sc_file_ops;
1524 }
1525 bh_org = bh;
1526 get_bh(bh_org);
1527 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1528 &binfo);
1529 if (bh != bh_org)
1530 nilfs_list_replace_buffer(bh_org, bh);
1531 brelse(bh_org);
1532 if (unlikely(err))
1533 goto failed_bmap;
1534
1535 if (ndatablk > 0)
1536 sc_op->write_data_binfo(sci, &ssp, &binfo);
1537 else
1538 sc_op->write_node_binfo(sci, &ssp, &binfo);
1539
1540 blocknr++;
1541 if (--nblocks == 0) {
1542 finfo = NULL;
1543 if (--nfinfo == 0)
1544 break;
1545 } else if (ndatablk > 0)
1546 ndatablk--;
1547 }
1548 out:
1549 return 0;
1550
1551 failed_bmap:
1552 return err;
1553 }
1554
1555 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1556 {
1557 struct nilfs_segment_buffer *segbuf;
1558 int err;
1559
1560 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1561 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1562 if (unlikely(err))
1563 return err;
1564 nilfs_segbuf_fill_in_segsum(segbuf);
1565 }
1566 return 0;
1567 }
1568
1569 static void nilfs_begin_page_io(struct page *page)
1570 {
1571 if (!page || PageWriteback(page))
1572 /* For split b-tree node pages, this function may be called
1573 twice. We ignore the 2nd or later calls by this check. */
1574 return;
1575
1576 lock_page(page);
1577 clear_page_dirty_for_io(page);
1578 set_page_writeback(page);
1579 unlock_page(page);
1580 }
1581
1582 static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
1583 {
1584 struct nilfs_segment_buffer *segbuf;
1585 struct page *bd_page = NULL, *fs_page = NULL;
1586
1587 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1588 struct buffer_head *bh;
1589
1590 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1591 b_assoc_buffers) {
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 if (bh->b_page != bd_page) {
1692 if (bd_page)
1693 end_page_writeback(bd_page);
1694 bd_page = bh->b_page;
1695 }
1696 }
1697
1698 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1699 b_assoc_buffers) {
1700 clear_buffer_async_write(bh);
1701 if (bh == segbuf->sb_super_root) {
1702 if (bh->b_page != bd_page) {
1703 end_page_writeback(bd_page);
1704 bd_page = bh->b_page;
1705 }
1706 break;
1707 }
1708 if (bh->b_page != fs_page) {
1709 nilfs_end_page_io(fs_page, err);
1710 fs_page = bh->b_page;
1711 }
1712 }
1713 }
1714 if (bd_page)
1715 end_page_writeback(bd_page);
1716
1717 nilfs_end_page_io(fs_page, err);
1718 }
1719
1720 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1721 struct the_nilfs *nilfs, int err)
1722 {
1723 LIST_HEAD(logs);
1724 int ret;
1725
1726 list_splice_tail_init(&sci->sc_write_logs, &logs);
1727 ret = nilfs_wait_on_logs(&logs);
1728 nilfs_abort_logs(&logs, ret ? : err);
1729
1730 list_splice_tail_init(&sci->sc_segbufs, &logs);
1731 nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1732 nilfs_free_incomplete_logs(&logs, nilfs);
1733
1734 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1735 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1736 sci->sc_freesegs,
1737 sci->sc_nfreesegs,
1738 NULL);
1739 WARN_ON(ret); /* do not happen */
1740 }
1741
1742 nilfs_destroy_logs(&logs);
1743 }
1744
1745 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1746 struct nilfs_segment_buffer *segbuf)
1747 {
1748 nilfs->ns_segnum = segbuf->sb_segnum;
1749 nilfs->ns_nextnum = segbuf->sb_nextnum;
1750 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1751 + segbuf->sb_sum.nblocks;
1752 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1753 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1754 }
1755
1756 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1757 {
1758 struct nilfs_segment_buffer *segbuf;
1759 struct page *bd_page = NULL, *fs_page = NULL;
1760 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1761 int update_sr = false;
1762
1763 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1764 struct buffer_head *bh;
1765
1766 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1767 b_assoc_buffers) {
1768 set_buffer_uptodate(bh);
1769 clear_buffer_dirty(bh);
1770 if (bh->b_page != bd_page) {
1771 if (bd_page)
1772 end_page_writeback(bd_page);
1773 bd_page = bh->b_page;
1774 }
1775 }
1776 /*
1777 * We assume that the buffers which belong to the same page
1778 * continue over the buffer list.
1779 * Under this assumption, the last BHs of pages is
1780 * identifiable by the discontinuity of bh->b_page
1781 * (page != fs_page).
1782 *
1783 * For B-tree node blocks, however, this assumption is not
1784 * guaranteed. The cleanup code of B-tree node pages needs
1785 * special care.
1786 */
1787 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1788 b_assoc_buffers) {
1789 const unsigned long set_bits = (1 << BH_Uptodate);
1790 const unsigned long clear_bits =
1791 (1 << BH_Dirty | 1 << BH_Async_Write |
1792 1 << BH_Delay | 1 << BH_NILFS_Volatile |
1793 1 << BH_NILFS_Redirected);
1794
1795 set_mask_bits(&bh->b_state, clear_bits, set_bits);
1796 if (bh == segbuf->sb_super_root) {
1797 if (bh->b_page != bd_page) {
1798 end_page_writeback(bd_page);
1799 bd_page = bh->b_page;
1800 }
1801 update_sr = true;
1802 break;
1803 }
1804 if (bh->b_page != fs_page) {
1805 nilfs_end_page_io(fs_page, 0);
1806 fs_page = bh->b_page;
1807 }
1808 }
1809
1810 if (!nilfs_segbuf_simplex(segbuf)) {
1811 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
1812 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1813 sci->sc_lseg_stime = jiffies;
1814 }
1815 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
1816 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1817 }
1818 }
1819 /*
1820 * Since pages may continue over multiple segment buffers,
1821 * end of the last page must be checked outside of the loop.
1822 */
1823 if (bd_page)
1824 end_page_writeback(bd_page);
1825
1826 nilfs_end_page_io(fs_page, 0);
1827
1828 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1829
1830 if (nilfs_doing_gc())
1831 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1832 else
1833 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1834
1835 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1836
1837 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1838 nilfs_set_next_segment(nilfs, segbuf);
1839
1840 if (update_sr) {
1841 nilfs->ns_flushed_device = 0;
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 during_mount = !(sci->sc_super->s_flags & MS_ACTIVE);
1910 int defer_iput = false;
1911
1912 spin_lock(&nilfs->ns_inode_lock);
1913 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
1914 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
1915 test_bit(NILFS_I_DIRTY, &ii->i_state))
1916 continue;
1917
1918 clear_bit(NILFS_I_BUSY, &ii->i_state);
1919 brelse(ii->i_bh);
1920 ii->i_bh = NULL;
1921 list_del_init(&ii->i_dirty);
1922 if (!ii->vfs_inode.i_nlink || during_mount) {
1923 /*
1924 * Defer calling iput() to avoid deadlocks if
1925 * i_nlink == 0 or mount is not yet finished.
1926 */
1927 list_add_tail(&ii->i_dirty, &sci->sc_iput_queue);
1928 defer_iput = true;
1929 } else {
1930 spin_unlock(&nilfs->ns_inode_lock);
1931 iput(&ii->vfs_inode);
1932 spin_lock(&nilfs->ns_inode_lock);
1933 }
1934 }
1935 spin_unlock(&nilfs->ns_inode_lock);
1936
1937 if (defer_iput)
1938 schedule_work(&sci->sc_iput_work);
1939 }
1940
1941 /*
1942 * Main procedure of segment constructor
1943 */
1944 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
1945 {
1946 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1947 int err;
1948
1949 sci->sc_stage.scnt = NILFS_ST_INIT;
1950 sci->sc_cno = nilfs->ns_cno;
1951
1952 err = nilfs_segctor_collect_dirty_files(sci, nilfs);
1953 if (unlikely(err))
1954 goto out;
1955
1956 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
1957 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1958
1959 if (nilfs_segctor_clean(sci))
1960 goto out;
1961
1962 do {
1963 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
1964
1965 err = nilfs_segctor_begin_construction(sci, nilfs);
1966 if (unlikely(err))
1967 goto out;
1968
1969 /* Update time stamp */
1970 sci->sc_seg_ctime = get_seconds();
1971
1972 err = nilfs_segctor_collect(sci, nilfs, mode);
1973 if (unlikely(err))
1974 goto failed;
1975
1976 /* Avoid empty segment */
1977 if (sci->sc_stage.scnt == NILFS_ST_DONE &&
1978 nilfs_segbuf_empty(sci->sc_curseg)) {
1979 nilfs_segctor_abort_construction(sci, nilfs, 1);
1980 goto out;
1981 }
1982
1983 err = nilfs_segctor_assign(sci, mode);
1984 if (unlikely(err))
1985 goto failed;
1986
1987 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
1988 nilfs_segctor_fill_in_file_bmap(sci);
1989
1990 if (mode == SC_LSEG_SR &&
1991 sci->sc_stage.scnt >= NILFS_ST_CPFILE) {
1992 err = nilfs_segctor_fill_in_checkpoint(sci);
1993 if (unlikely(err))
1994 goto failed_to_write;
1995
1996 nilfs_segctor_fill_in_super_root(sci, nilfs);
1997 }
1998 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
1999
2000 /* Write partial segments */
2001 nilfs_segctor_prepare_write(sci);
2002
2003 nilfs_add_checksums_on_logs(&sci->sc_segbufs,
2004 nilfs->ns_crc_seed);
2005
2006 err = nilfs_segctor_write(sci, nilfs);
2007 if (unlikely(err))
2008 goto failed_to_write;
2009
2010 if (sci->sc_stage.scnt == NILFS_ST_DONE ||
2011 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
2012 /*
2013 * At this point, we avoid double buffering
2014 * for blocksize < pagesize because page dirty
2015 * flag is turned off during write and dirty
2016 * buffers are not properly collected for
2017 * pages crossing over segments.
2018 */
2019 err = nilfs_segctor_wait(sci);
2020 if (err)
2021 goto failed_to_write;
2022 }
2023 } while (sci->sc_stage.scnt != NILFS_ST_DONE);
2024
2025 out:
2026 nilfs_segctor_drop_written_files(sci, nilfs);
2027 return err;
2028
2029 failed_to_write:
2030 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2031 nilfs_redirty_inodes(&sci->sc_dirty_files);
2032
2033 failed:
2034 if (nilfs_doing_gc())
2035 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2036 nilfs_segctor_abort_construction(sci, nilfs, err);
2037 goto out;
2038 }
2039
2040 /**
2041 * nilfs_segctor_start_timer - set timer of background write
2042 * @sci: nilfs_sc_info
2043 *
2044 * If the timer has already been set, it ignores the new request.
2045 * This function MUST be called within a section locking the segment
2046 * semaphore.
2047 */
2048 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2049 {
2050 spin_lock(&sci->sc_state_lock);
2051 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2052 sci->sc_timer.expires = jiffies + sci->sc_interval;
2053 add_timer(&sci->sc_timer);
2054 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2055 }
2056 spin_unlock(&sci->sc_state_lock);
2057 }
2058
2059 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2060 {
2061 spin_lock(&sci->sc_state_lock);
2062 if (!(sci->sc_flush_request & (1 << bn))) {
2063 unsigned long prev_req = sci->sc_flush_request;
2064
2065 sci->sc_flush_request |= (1 << bn);
2066 if (!prev_req)
2067 wake_up(&sci->sc_wait_daemon);
2068 }
2069 spin_unlock(&sci->sc_state_lock);
2070 }
2071
2072 /**
2073 * nilfs_flush_segment - trigger a segment construction for resource control
2074 * @sb: super block
2075 * @ino: inode number of the file to be flushed out.
2076 */
2077 void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2078 {
2079 struct the_nilfs *nilfs = sb->s_fs_info;
2080 struct nilfs_sc_info *sci = nilfs->ns_writer;
2081
2082 if (!sci || nilfs_doing_construction())
2083 return;
2084 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2085 /* assign bit 0 to data files */
2086 }
2087
2088 struct nilfs_segctor_wait_request {
2089 wait_queue_t wq;
2090 __u32 seq;
2091 int err;
2092 atomic_t done;
2093 };
2094
2095 static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2096 {
2097 struct nilfs_segctor_wait_request wait_req;
2098 int err = 0;
2099
2100 spin_lock(&sci->sc_state_lock);
2101 init_wait(&wait_req.wq);
2102 wait_req.err = 0;
2103 atomic_set(&wait_req.done, 0);
2104 wait_req.seq = ++sci->sc_seq_request;
2105 spin_unlock(&sci->sc_state_lock);
2106
2107 init_waitqueue_entry(&wait_req.wq, current);
2108 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2109 set_current_state(TASK_INTERRUPTIBLE);
2110 wake_up(&sci->sc_wait_daemon);
2111
2112 for (;;) {
2113 if (atomic_read(&wait_req.done)) {
2114 err = wait_req.err;
2115 break;
2116 }
2117 if (!signal_pending(current)) {
2118 schedule();
2119 continue;
2120 }
2121 err = -ERESTARTSYS;
2122 break;
2123 }
2124 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2125 return err;
2126 }
2127
2128 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2129 {
2130 struct nilfs_segctor_wait_request *wrq, *n;
2131 unsigned long flags;
2132
2133 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2134 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2135 wq.task_list) {
2136 if (!atomic_read(&wrq->done) &&
2137 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2138 wrq->err = err;
2139 atomic_set(&wrq->done, 1);
2140 }
2141 if (atomic_read(&wrq->done)) {
2142 wrq->wq.func(&wrq->wq,
2143 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2144 0, NULL);
2145 }
2146 }
2147 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2148 }
2149
2150 /**
2151 * nilfs_construct_segment - construct a logical segment
2152 * @sb: super block
2153 *
2154 * Return Value: On success, 0 is retured. On errors, one of the following
2155 * negative error code is returned.
2156 *
2157 * %-EROFS - Read only filesystem.
2158 *
2159 * %-EIO - I/O error
2160 *
2161 * %-ENOSPC - No space left on device (only in a panic state).
2162 *
2163 * %-ERESTARTSYS - Interrupted.
2164 *
2165 * %-ENOMEM - Insufficient memory available.
2166 */
2167 int nilfs_construct_segment(struct super_block *sb)
2168 {
2169 struct the_nilfs *nilfs = sb->s_fs_info;
2170 struct nilfs_sc_info *sci = nilfs->ns_writer;
2171 struct nilfs_transaction_info *ti;
2172 int err;
2173
2174 if (!sci)
2175 return -EROFS;
2176
2177 /* A call inside transactions causes a deadlock. */
2178 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2179
2180 err = nilfs_segctor_sync(sci);
2181 return err;
2182 }
2183
2184 /**
2185 * nilfs_construct_dsync_segment - construct a data-only logical segment
2186 * @sb: super block
2187 * @inode: inode whose data blocks should be written out
2188 * @start: start byte offset
2189 * @end: end byte offset (inclusive)
2190 *
2191 * Return Value: On success, 0 is retured. On errors, one of the following
2192 * negative error code is returned.
2193 *
2194 * %-EROFS - Read only filesystem.
2195 *
2196 * %-EIO - I/O error
2197 *
2198 * %-ENOSPC - No space left on device (only in a panic state).
2199 *
2200 * %-ERESTARTSYS - Interrupted.
2201 *
2202 * %-ENOMEM - Insufficient memory available.
2203 */
2204 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2205 loff_t start, loff_t end)
2206 {
2207 struct the_nilfs *nilfs = sb->s_fs_info;
2208 struct nilfs_sc_info *sci = nilfs->ns_writer;
2209 struct nilfs_inode_info *ii;
2210 struct nilfs_transaction_info ti;
2211 int err = 0;
2212
2213 if (!sci)
2214 return -EROFS;
2215
2216 nilfs_transaction_lock(sb, &ti, 0);
2217
2218 ii = NILFS_I(inode);
2219 if (test_bit(NILFS_I_INODE_SYNC, &ii->i_state) ||
2220 nilfs_test_opt(nilfs, STRICT_ORDER) ||
2221 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2222 nilfs_discontinued(nilfs)) {
2223 nilfs_transaction_unlock(sb);
2224 err = nilfs_segctor_sync(sci);
2225 return err;
2226 }
2227
2228 spin_lock(&nilfs->ns_inode_lock);
2229 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2230 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2231 spin_unlock(&nilfs->ns_inode_lock);
2232 nilfs_transaction_unlock(sb);
2233 return 0;
2234 }
2235 spin_unlock(&nilfs->ns_inode_lock);
2236 sci->sc_dsync_inode = ii;
2237 sci->sc_dsync_start = start;
2238 sci->sc_dsync_end = end;
2239
2240 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2241 if (!err)
2242 nilfs->ns_flushed_device = 0;
2243
2244 nilfs_transaction_unlock(sb);
2245 return err;
2246 }
2247
2248 #define FLUSH_FILE_BIT (0x1) /* data file only */
2249 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2250
2251 /**
2252 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2253 * @sci: segment constructor object
2254 */
2255 static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2256 {
2257 spin_lock(&sci->sc_state_lock);
2258 sci->sc_seq_accepted = sci->sc_seq_request;
2259 spin_unlock(&sci->sc_state_lock);
2260 del_timer_sync(&sci->sc_timer);
2261 }
2262
2263 /**
2264 * nilfs_segctor_notify - notify the result of request to caller threads
2265 * @sci: segment constructor object
2266 * @mode: mode of log forming
2267 * @err: error code to be notified
2268 */
2269 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2270 {
2271 /* Clear requests (even when the construction failed) */
2272 spin_lock(&sci->sc_state_lock);
2273
2274 if (mode == SC_LSEG_SR) {
2275 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2276 sci->sc_seq_done = sci->sc_seq_accepted;
2277 nilfs_segctor_wakeup(sci, err);
2278 sci->sc_flush_request = 0;
2279 } else {
2280 if (mode == SC_FLUSH_FILE)
2281 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2282 else if (mode == SC_FLUSH_DAT)
2283 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2284
2285 /* re-enable timer if checkpoint creation was not done */
2286 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2287 time_before(jiffies, sci->sc_timer.expires))
2288 add_timer(&sci->sc_timer);
2289 }
2290 spin_unlock(&sci->sc_state_lock);
2291 }
2292
2293 /**
2294 * nilfs_segctor_construct - form logs and write them to disk
2295 * @sci: segment constructor object
2296 * @mode: mode of log forming
2297 */
2298 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2299 {
2300 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2301 struct nilfs_super_block **sbp;
2302 int err = 0;
2303
2304 nilfs_segctor_accept(sci);
2305
2306 if (nilfs_discontinued(nilfs))
2307 mode = SC_LSEG_SR;
2308 if (!nilfs_segctor_confirm(sci))
2309 err = nilfs_segctor_do_construct(sci, mode);
2310
2311 if (likely(!err)) {
2312 if (mode != SC_FLUSH_DAT)
2313 atomic_set(&nilfs->ns_ndirtyblks, 0);
2314 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2315 nilfs_discontinued(nilfs)) {
2316 down_write(&nilfs->ns_sem);
2317 err = -EIO;
2318 sbp = nilfs_prepare_super(sci->sc_super,
2319 nilfs_sb_will_flip(nilfs));
2320 if (likely(sbp)) {
2321 nilfs_set_log_cursor(sbp[0], nilfs);
2322 err = nilfs_commit_super(sci->sc_super,
2323 NILFS_SB_COMMIT);
2324 }
2325 up_write(&nilfs->ns_sem);
2326 }
2327 }
2328
2329 nilfs_segctor_notify(sci, mode, err);
2330 return err;
2331 }
2332
2333 static void nilfs_construction_timeout(unsigned long data)
2334 {
2335 struct task_struct *p = (struct task_struct *)data;
2336 wake_up_process(p);
2337 }
2338
2339 static void
2340 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2341 {
2342 struct nilfs_inode_info *ii, *n;
2343
2344 list_for_each_entry_safe(ii, n, head, i_dirty) {
2345 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2346 continue;
2347 list_del_init(&ii->i_dirty);
2348 truncate_inode_pages(&ii->vfs_inode.i_data, 0);
2349 nilfs_btnode_cache_clear(&ii->i_btnode_cache);
2350 iput(&ii->vfs_inode);
2351 }
2352 }
2353
2354 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2355 void **kbufs)
2356 {
2357 struct the_nilfs *nilfs = sb->s_fs_info;
2358 struct nilfs_sc_info *sci = nilfs->ns_writer;
2359 struct nilfs_transaction_info ti;
2360 int err;
2361
2362 if (unlikely(!sci))
2363 return -EROFS;
2364
2365 nilfs_transaction_lock(sb, &ti, 1);
2366
2367 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2368 if (unlikely(err))
2369 goto out_unlock;
2370
2371 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2372 if (unlikely(err)) {
2373 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2374 goto out_unlock;
2375 }
2376
2377 sci->sc_freesegs = kbufs[4];
2378 sci->sc_nfreesegs = argv[4].v_nmembs;
2379 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2380
2381 for (;;) {
2382 err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2383 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2384
2385 if (likely(!err))
2386 break;
2387
2388 nilfs_warning(sb, __func__,
2389 "segment construction failed. (err=%d)", err);
2390 set_current_state(TASK_INTERRUPTIBLE);
2391 schedule_timeout(sci->sc_interval);
2392 }
2393 if (nilfs_test_opt(nilfs, DISCARD)) {
2394 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2395 sci->sc_nfreesegs);
2396 if (ret) {
2397 printk(KERN_WARNING
2398 "NILFS warning: error %d on discard request, "
2399 "turning discards off for the device\n", ret);
2400 nilfs_clear_opt(nilfs, DISCARD);
2401 }
2402 }
2403
2404 out_unlock:
2405 sci->sc_freesegs = NULL;
2406 sci->sc_nfreesegs = 0;
2407 nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2408 nilfs_transaction_unlock(sb);
2409 return err;
2410 }
2411
2412 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2413 {
2414 struct nilfs_transaction_info ti;
2415
2416 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2417 nilfs_segctor_construct(sci, mode);
2418
2419 /*
2420 * Unclosed segment should be retried. We do this using sc_timer.
2421 * Timeout of sc_timer will invoke complete construction which leads
2422 * to close the current logical segment.
2423 */
2424 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2425 nilfs_segctor_start_timer(sci);
2426
2427 nilfs_transaction_unlock(sci->sc_super);
2428 }
2429
2430 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2431 {
2432 int mode = 0;
2433 int err;
2434
2435 spin_lock(&sci->sc_state_lock);
2436 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2437 SC_FLUSH_DAT : SC_FLUSH_FILE;
2438 spin_unlock(&sci->sc_state_lock);
2439
2440 if (mode) {
2441 err = nilfs_segctor_do_construct(sci, mode);
2442
2443 spin_lock(&sci->sc_state_lock);
2444 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2445 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2446 spin_unlock(&sci->sc_state_lock);
2447 }
2448 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2449 }
2450
2451 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2452 {
2453 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2454 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2455 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2456 return SC_FLUSH_FILE;
2457 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2458 return SC_FLUSH_DAT;
2459 }
2460 return SC_LSEG_SR;
2461 }
2462
2463 /**
2464 * nilfs_segctor_thread - main loop of the segment constructor thread.
2465 * @arg: pointer to a struct nilfs_sc_info.
2466 *
2467 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2468 * to execute segment constructions.
2469 */
2470 static int nilfs_segctor_thread(void *arg)
2471 {
2472 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2473 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2474 int timeout = 0;
2475
2476 sci->sc_timer.data = (unsigned long)current;
2477 sci->sc_timer.function = nilfs_construction_timeout;
2478
2479 /* start sync. */
2480 sci->sc_task = current;
2481 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2482 printk(KERN_INFO
2483 "segctord starting. Construction interval = %lu seconds, "
2484 "CP frequency < %lu seconds\n",
2485 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2486
2487 spin_lock(&sci->sc_state_lock);
2488 loop:
2489 for (;;) {
2490 int mode;
2491
2492 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2493 goto end_thread;
2494
2495 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2496 mode = SC_LSEG_SR;
2497 else if (!sci->sc_flush_request)
2498 break;
2499 else
2500 mode = nilfs_segctor_flush_mode(sci);
2501
2502 spin_unlock(&sci->sc_state_lock);
2503 nilfs_segctor_thread_construct(sci, mode);
2504 spin_lock(&sci->sc_state_lock);
2505 timeout = 0;
2506 }
2507
2508
2509 if (freezing(current)) {
2510 spin_unlock(&sci->sc_state_lock);
2511 try_to_freeze();
2512 spin_lock(&sci->sc_state_lock);
2513 } else {
2514 DEFINE_WAIT(wait);
2515 int should_sleep = 1;
2516
2517 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2518 TASK_INTERRUPTIBLE);
2519
2520 if (sci->sc_seq_request != sci->sc_seq_done)
2521 should_sleep = 0;
2522 else if (sci->sc_flush_request)
2523 should_sleep = 0;
2524 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2525 should_sleep = time_before(jiffies,
2526 sci->sc_timer.expires);
2527
2528 if (should_sleep) {
2529 spin_unlock(&sci->sc_state_lock);
2530 schedule();
2531 spin_lock(&sci->sc_state_lock);
2532 }
2533 finish_wait(&sci->sc_wait_daemon, &wait);
2534 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2535 time_after_eq(jiffies, sci->sc_timer.expires));
2536
2537 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2538 set_nilfs_discontinued(nilfs);
2539 }
2540 goto loop;
2541
2542 end_thread:
2543 spin_unlock(&sci->sc_state_lock);
2544
2545 /* end sync. */
2546 sci->sc_task = NULL;
2547 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2548 return 0;
2549 }
2550
2551 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2552 {
2553 struct task_struct *t;
2554
2555 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2556 if (IS_ERR(t)) {
2557 int err = PTR_ERR(t);
2558
2559 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2560 err);
2561 return err;
2562 }
2563 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2564 return 0;
2565 }
2566
2567 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2568 __acquires(&sci->sc_state_lock)
2569 __releases(&sci->sc_state_lock)
2570 {
2571 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2572
2573 while (sci->sc_task) {
2574 wake_up(&sci->sc_wait_daemon);
2575 spin_unlock(&sci->sc_state_lock);
2576 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2577 spin_lock(&sci->sc_state_lock);
2578 }
2579 }
2580
2581 /*
2582 * Setup & clean-up functions
2583 */
2584 static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
2585 struct nilfs_root *root)
2586 {
2587 struct the_nilfs *nilfs = sb->s_fs_info;
2588 struct nilfs_sc_info *sci;
2589
2590 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2591 if (!sci)
2592 return NULL;
2593
2594 sci->sc_super = sb;
2595
2596 nilfs_get_root(root);
2597 sci->sc_root = root;
2598
2599 init_waitqueue_head(&sci->sc_wait_request);
2600 init_waitqueue_head(&sci->sc_wait_daemon);
2601 init_waitqueue_head(&sci->sc_wait_task);
2602 spin_lock_init(&sci->sc_state_lock);
2603 INIT_LIST_HEAD(&sci->sc_dirty_files);
2604 INIT_LIST_HEAD(&sci->sc_segbufs);
2605 INIT_LIST_HEAD(&sci->sc_write_logs);
2606 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2607 INIT_LIST_HEAD(&sci->sc_iput_queue);
2608 INIT_WORK(&sci->sc_iput_work, nilfs_iput_work_func);
2609 init_timer(&sci->sc_timer);
2610
2611 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2612 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2613 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2614
2615 if (nilfs->ns_interval)
2616 sci->sc_interval = HZ * nilfs->ns_interval;
2617 if (nilfs->ns_watermark)
2618 sci->sc_watermark = nilfs->ns_watermark;
2619 return sci;
2620 }
2621
2622 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2623 {
2624 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2625
2626 /* The segctord thread was stopped and its timer was removed.
2627 But some tasks remain. */
2628 do {
2629 struct nilfs_transaction_info ti;
2630
2631 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2632 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2633 nilfs_transaction_unlock(sci->sc_super);
2634
2635 flush_work(&sci->sc_iput_work);
2636
2637 } while (ret && retrycount-- > 0);
2638 }
2639
2640 /**
2641 * nilfs_segctor_destroy - destroy the segment constructor.
2642 * @sci: nilfs_sc_info
2643 *
2644 * nilfs_segctor_destroy() kills the segctord thread and frees
2645 * the nilfs_sc_info struct.
2646 * Caller must hold the segment semaphore.
2647 */
2648 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2649 {
2650 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2651 int flag;
2652
2653 up_write(&nilfs->ns_segctor_sem);
2654
2655 spin_lock(&sci->sc_state_lock);
2656 nilfs_segctor_kill_thread(sci);
2657 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2658 || sci->sc_seq_request != sci->sc_seq_done);
2659 spin_unlock(&sci->sc_state_lock);
2660
2661 if (flush_work(&sci->sc_iput_work))
2662 flag = true;
2663
2664 if (flag || !nilfs_segctor_confirm(sci))
2665 nilfs_segctor_write_out(sci);
2666
2667 if (!list_empty(&sci->sc_dirty_files)) {
2668 nilfs_warning(sci->sc_super, __func__,
2669 "dirty file(s) after the final construction\n");
2670 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
2671 }
2672
2673 if (!list_empty(&sci->sc_iput_queue)) {
2674 nilfs_warning(sci->sc_super, __func__,
2675 "iput queue is not empty\n");
2676 nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 1);
2677 }
2678
2679 WARN_ON(!list_empty(&sci->sc_segbufs));
2680 WARN_ON(!list_empty(&sci->sc_write_logs));
2681
2682 nilfs_put_root(sci->sc_root);
2683
2684 down_write(&nilfs->ns_segctor_sem);
2685
2686 del_timer_sync(&sci->sc_timer);
2687 kfree(sci);
2688 }
2689
2690 /**
2691 * nilfs_attach_log_writer - attach log writer
2692 * @sb: super block instance
2693 * @root: root object of the current filesystem tree
2694 *
2695 * This allocates a log writer object, initializes it, and starts the
2696 * log writer.
2697 *
2698 * Return Value: On success, 0 is returned. On error, one of the following
2699 * negative error code is returned.
2700 *
2701 * %-ENOMEM - Insufficient memory available.
2702 */
2703 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
2704 {
2705 struct the_nilfs *nilfs = sb->s_fs_info;
2706 int err;
2707
2708 if (nilfs->ns_writer) {
2709 /*
2710 * This happens if the filesystem was remounted
2711 * read/write after nilfs_error degenerated it into a
2712 * read-only mount.
2713 */
2714 nilfs_detach_log_writer(sb);
2715 }
2716
2717 nilfs->ns_writer = nilfs_segctor_new(sb, root);
2718 if (!nilfs->ns_writer)
2719 return -ENOMEM;
2720
2721 err = nilfs_segctor_start_thread(nilfs->ns_writer);
2722 if (err) {
2723 kfree(nilfs->ns_writer);
2724 nilfs->ns_writer = NULL;
2725 }
2726 return err;
2727 }
2728
2729 /**
2730 * nilfs_detach_log_writer - destroy log writer
2731 * @sb: super block instance
2732 *
2733 * This kills log writer daemon, frees the log writer object, and
2734 * destroys list of dirty files.
2735 */
2736 void nilfs_detach_log_writer(struct super_block *sb)
2737 {
2738 struct the_nilfs *nilfs = sb->s_fs_info;
2739 LIST_HEAD(garbage_list);
2740
2741 down_write(&nilfs->ns_segctor_sem);
2742 if (nilfs->ns_writer) {
2743 nilfs_segctor_destroy(nilfs->ns_writer);
2744 nilfs->ns_writer = NULL;
2745 }
2746
2747 /* Force to free the list of dirty files */
2748 spin_lock(&nilfs->ns_inode_lock);
2749 if (!list_empty(&nilfs->ns_dirty_files)) {
2750 list_splice_init(&nilfs->ns_dirty_files, &garbage_list);
2751 nilfs_warning(sb, __func__,
2752 "Hit dirty file after stopped log writer\n");
2753 }
2754 spin_unlock(&nilfs->ns_inode_lock);
2755 up_write(&nilfs->ns_segctor_sem);
2756
2757 nilfs_dispose_list(nilfs, &garbage_list, 1);
2758 }
Linux with added FPC-III support