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Linux 3.12.5
[linux/fpc-iii.git] / fs / nilfs2 / segment.c
blob9f6b486b6c01a0e6711ca5930e78474d0739e35e
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 INIT_LIST_HEAD(&ti->ti_garbage);
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 if (!list_empty(&ti->ti_garbage))
336 nilfs_dispose_list(nilfs, &ti->ti_garbage, 0);
337 }
338
339 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
340 struct nilfs_segsum_pointer *ssp,
341 unsigned bytes)
342 {
343 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
344 unsigned blocksize = sci->sc_super->s_blocksize;
345 void *p;
346
347 if (unlikely(ssp->offset + bytes > blocksize)) {
348 ssp->offset = 0;
349 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
350 &segbuf->sb_segsum_buffers));
351 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
352 }
353 p = ssp->bh->b_data + ssp->offset;
354 ssp->offset += bytes;
355 return p;
356 }
357
358 /**
359 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
360 * @sci: nilfs_sc_info
361 */
362 static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
363 {
364 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
365 struct buffer_head *sumbh;
366 unsigned sumbytes;
367 unsigned flags = 0;
368 int err;
369
370 if (nilfs_doing_gc())
371 flags = NILFS_SS_GC;
372 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno);
373 if (unlikely(err))
374 return err;
375
376 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
377 sumbytes = segbuf->sb_sum.sumbytes;
378 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
379 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
380 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
381 return 0;
382 }
383
384 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
385 {
386 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
387 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
388 return -E2BIG; /* The current segment is filled up
389 (internal code) */
390 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
391 return nilfs_segctor_reset_segment_buffer(sci);
392 }
393
394 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
395 {
396 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
397 int err;
398
399 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
400 err = nilfs_segctor_feed_segment(sci);
401 if (err)
402 return err;
403 segbuf = sci->sc_curseg;
404 }
405 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root);
406 if (likely(!err))
407 segbuf->sb_sum.flags |= NILFS_SS_SR;
408 return err;
409 }
410
411 /*
412 * Functions for making segment summary and payloads
413 */
414 static int nilfs_segctor_segsum_block_required(
415 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
416 unsigned binfo_size)
417 {
418 unsigned blocksize = sci->sc_super->s_blocksize;
419 /* Size of finfo and binfo is enough small against blocksize */
420
421 return ssp->offset + binfo_size +
422 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
423 blocksize;
424 }
425
426 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
427 struct inode *inode)
428 {
429 sci->sc_curseg->sb_sum.nfinfo++;
430 sci->sc_binfo_ptr = sci->sc_finfo_ptr;
431 nilfs_segctor_map_segsum_entry(
432 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
433
434 if (NILFS_I(inode)->i_root &&
435 !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
436 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
437 /* skip finfo */
438 }
439
440 static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
441 struct inode *inode)
442 {
443 struct nilfs_finfo *finfo;
444 struct nilfs_inode_info *ii;
445 struct nilfs_segment_buffer *segbuf;
446 __u64 cno;
447
448 if (sci->sc_blk_cnt == 0)
449 return;
450
451 ii = NILFS_I(inode);
452
453 if (test_bit(NILFS_I_GCINODE, &ii->i_state))
454 cno = ii->i_cno;
455 else if (NILFS_ROOT_METADATA_FILE(inode->i_ino))
456 cno = 0;
457 else
458 cno = sci->sc_cno;
459
460 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
461 sizeof(*finfo));
462 finfo->fi_ino = cpu_to_le64(inode->i_ino);
463 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
464 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
465 finfo->fi_cno = cpu_to_le64(cno);
466
467 segbuf = sci->sc_curseg;
468 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
469 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
470 sci->sc_finfo_ptr = sci->sc_binfo_ptr;
471 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
472 }
473
474 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
475 struct buffer_head *bh,
476 struct inode *inode,
477 unsigned binfo_size)
478 {
479 struct nilfs_segment_buffer *segbuf;
480 int required, err = 0;
481
482 retry:
483 segbuf = sci->sc_curseg;
484 required = nilfs_segctor_segsum_block_required(
485 sci, &sci->sc_binfo_ptr, binfo_size);
486 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
487 nilfs_segctor_end_finfo(sci, inode);
488 err = nilfs_segctor_feed_segment(sci);
489 if (err)
490 return err;
491 goto retry;
492 }
493 if (unlikely(required)) {
494 err = nilfs_segbuf_extend_segsum(segbuf);
495 if (unlikely(err))
496 goto failed;
497 }
498 if (sci->sc_blk_cnt == 0)
499 nilfs_segctor_begin_finfo(sci, inode);
500
501 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
502 /* Substitution to vblocknr is delayed until update_blocknr() */
503 nilfs_segbuf_add_file_buffer(segbuf, bh);
504 sci->sc_blk_cnt++;
505 failed:
506 return err;
507 }
508
509 /*
510 * Callback functions that enumerate, mark, and collect dirty blocks
511 */
512 static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
513 struct buffer_head *bh, struct inode *inode)
514 {
515 int err;
516
517 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
518 if (err < 0)
519 return err;
520
521 err = nilfs_segctor_add_file_block(sci, bh, inode,
522 sizeof(struct nilfs_binfo_v));
523 if (!err)
524 sci->sc_datablk_cnt++;
525 return err;
526 }
527
528 static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
529 struct buffer_head *bh,
530 struct inode *inode)
531 {
532 return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
533 }
534
535 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
536 struct buffer_head *bh,
537 struct inode *inode)
538 {
539 WARN_ON(!buffer_dirty(bh));
540 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
541 }
542
543 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
544 struct nilfs_segsum_pointer *ssp,
545 union nilfs_binfo *binfo)
546 {
547 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
548 sci, ssp, sizeof(*binfo_v));
549 *binfo_v = binfo->bi_v;
550 }
551
552 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
553 struct nilfs_segsum_pointer *ssp,
554 union nilfs_binfo *binfo)
555 {
556 __le64 *vblocknr = nilfs_segctor_map_segsum_entry(
557 sci, ssp, sizeof(*vblocknr));
558 *vblocknr = binfo->bi_v.bi_vblocknr;
559 }
560
561 static struct nilfs_sc_operations nilfs_sc_file_ops = {
562 .collect_data = nilfs_collect_file_data,
563 .collect_node = nilfs_collect_file_node,
564 .collect_bmap = nilfs_collect_file_bmap,
565 .write_data_binfo = nilfs_write_file_data_binfo,
566 .write_node_binfo = nilfs_write_file_node_binfo,
567 };
568
569 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
570 struct buffer_head *bh, struct inode *inode)
571 {
572 int err;
573
574 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
575 if (err < 0)
576 return err;
577
578 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
579 if (!err)
580 sci->sc_datablk_cnt++;
581 return err;
582 }
583
584 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
585 struct buffer_head *bh, struct inode *inode)
586 {
587 WARN_ON(!buffer_dirty(bh));
588 return nilfs_segctor_add_file_block(sci, bh, inode,
589 sizeof(struct nilfs_binfo_dat));
590 }
591
592 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
593 struct nilfs_segsum_pointer *ssp,
594 union nilfs_binfo *binfo)
595 {
596 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
597 sizeof(*blkoff));
598 *blkoff = binfo->bi_dat.bi_blkoff;
599 }
600
601 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
602 struct nilfs_segsum_pointer *ssp,
603 union nilfs_binfo *binfo)
604 {
605 struct nilfs_binfo_dat *binfo_dat =
606 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
607 *binfo_dat = binfo->bi_dat;
608 }
609
610 static struct nilfs_sc_operations nilfs_sc_dat_ops = {
611 .collect_data = nilfs_collect_dat_data,
612 .collect_node = nilfs_collect_file_node,
613 .collect_bmap = nilfs_collect_dat_bmap,
614 .write_data_binfo = nilfs_write_dat_data_binfo,
615 .write_node_binfo = nilfs_write_dat_node_binfo,
616 };
617
618 static struct nilfs_sc_operations nilfs_sc_dsync_ops = {
619 .collect_data = nilfs_collect_file_data,
620 .collect_node = NULL,
621 .collect_bmap = NULL,
622 .write_data_binfo = nilfs_write_file_data_binfo,
623 .write_node_binfo = NULL,
624 };
625
626 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
627 struct list_head *listp,
628 size_t nlimit,
629 loff_t start, loff_t end)
630 {
631 struct address_space *mapping = inode->i_mapping;
632 struct pagevec pvec;
633 pgoff_t index = 0, last = ULONG_MAX;
634 size_t ndirties = 0;
635 int i;
636
637 if (unlikely(start != 0 || end != LLONG_MAX)) {
638 /*
639 * A valid range is given for sync-ing data pages. The
640 * range is rounded to per-page; extra dirty buffers
641 * may be included if blocksize < pagesize.
642 */
643 index = start >> PAGE_SHIFT;
644 last = end >> PAGE_SHIFT;
645 }
646 pagevec_init(&pvec, 0);
647 repeat:
648 if (unlikely(index > last) ||
649 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
650 min_t(pgoff_t, last - index,
651 PAGEVEC_SIZE - 1) + 1))
652 return ndirties;
653
654 for (i = 0; i < pagevec_count(&pvec); i++) {
655 struct buffer_head *bh, *head;
656 struct page *page = pvec.pages[i];
657
658 if (unlikely(page->index > last))
659 break;
660
661 lock_page(page);
662 if (!page_has_buffers(page))
663 create_empty_buffers(page, 1 << inode->i_blkbits, 0);
664 unlock_page(page);
665
666 bh = head = page_buffers(page);
667 do {
668 if (!buffer_dirty(bh) || buffer_async_write(bh))
669 continue;
670 get_bh(bh);
671 list_add_tail(&bh->b_assoc_buffers, listp);
672 ndirties++;
673 if (unlikely(ndirties >= nlimit)) {
674 pagevec_release(&pvec);
675 cond_resched();
676 return ndirties;
677 }
678 } while (bh = bh->b_this_page, bh != head);
679 }
680 pagevec_release(&pvec);
681 cond_resched();
682 goto repeat;
683 }
684
685 static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
686 struct list_head *listp)
687 {
688 struct nilfs_inode_info *ii = NILFS_I(inode);
689 struct address_space *mapping = &ii->i_btnode_cache;
690 struct pagevec pvec;
691 struct buffer_head *bh, *head;
692 unsigned int i;
693 pgoff_t index = 0;
694
695 pagevec_init(&pvec, 0);
696
697 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
698 PAGEVEC_SIZE)) {
699 for (i = 0; i < pagevec_count(&pvec); i++) {
700 bh = head = page_buffers(pvec.pages[i]);
701 do {
702 if (buffer_dirty(bh) &&
703 !buffer_async_write(bh)) {
704 get_bh(bh);
705 list_add_tail(&bh->b_assoc_buffers,
706 listp);
707 }
708 bh = bh->b_this_page;
709 } while (bh != head);
710 }
711 pagevec_release(&pvec);
712 cond_resched();
713 }
714 }
715
716 static void nilfs_dispose_list(struct the_nilfs *nilfs,
717 struct list_head *head, int force)
718 {
719 struct nilfs_inode_info *ii, *n;
720 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
721 unsigned nv = 0;
722
723 while (!list_empty(head)) {
724 spin_lock(&nilfs->ns_inode_lock);
725 list_for_each_entry_safe(ii, n, head, i_dirty) {
726 list_del_init(&ii->i_dirty);
727 if (force) {
728 if (unlikely(ii->i_bh)) {
729 brelse(ii->i_bh);
730 ii->i_bh = NULL;
731 }
732 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
733 set_bit(NILFS_I_QUEUED, &ii->i_state);
734 list_add_tail(&ii->i_dirty,
735 &nilfs->ns_dirty_files);
736 continue;
737 }
738 ivec[nv++] = ii;
739 if (nv == SC_N_INODEVEC)
740 break;
741 }
742 spin_unlock(&nilfs->ns_inode_lock);
743
744 for (pii = ivec; nv > 0; pii++, nv--)
745 iput(&(*pii)->vfs_inode);
746 }
747 }
748
749 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
750 struct nilfs_root *root)
751 {
752 int ret = 0;
753
754 if (nilfs_mdt_fetch_dirty(root->ifile))
755 ret++;
756 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
757 ret++;
758 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
759 ret++;
760 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat))
761 ret++;
762 return ret;
763 }
764
765 static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
766 {
767 return list_empty(&sci->sc_dirty_files) &&
768 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
769 sci->sc_nfreesegs == 0 &&
770 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
771 }
772
773 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
774 {
775 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
776 int ret = 0;
777
778 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
779 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
780
781 spin_lock(&nilfs->ns_inode_lock);
782 if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci))
783 ret++;
784
785 spin_unlock(&nilfs->ns_inode_lock);
786 return ret;
787 }
788
789 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
790 {
791 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
792
793 nilfs_mdt_clear_dirty(sci->sc_root->ifile);
794 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
795 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
796 nilfs_mdt_clear_dirty(nilfs->ns_dat);
797 }
798
799 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
800 {
801 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
802 struct buffer_head *bh_cp;
803 struct nilfs_checkpoint *raw_cp;
804 int err;
805
806 /* XXX: this interface will be changed */
807 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
808 &raw_cp, &bh_cp);
809 if (likely(!err)) {
810 /* The following code is duplicated with cpfile. But, it is
811 needed to collect the checkpoint even if it was not newly
812 created */
813 mark_buffer_dirty(bh_cp);
814 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
815 nilfs_cpfile_put_checkpoint(
816 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
817 } else
818 WARN_ON(err == -EINVAL || err == -ENOENT);
819
820 return err;
821 }
822
823 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
824 {
825 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
826 struct buffer_head *bh_cp;
827 struct nilfs_checkpoint *raw_cp;
828 int err;
829
830 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
831 &raw_cp, &bh_cp);
832 if (unlikely(err)) {
833 WARN_ON(err == -EINVAL || err == -ENOENT);
834 goto failed_ibh;
835 }
836 raw_cp->cp_snapshot_list.ssl_next = 0;
837 raw_cp->cp_snapshot_list.ssl_prev = 0;
838 raw_cp->cp_inodes_count =
839 cpu_to_le64(atomic64_read(&sci->sc_root->inodes_count));
840 raw_cp->cp_blocks_count =
841 cpu_to_le64(atomic64_read(&sci->sc_root->blocks_count));
842 raw_cp->cp_nblk_inc =
843 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
844 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
845 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
846
847 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
848 nilfs_checkpoint_clear_minor(raw_cp);
849 else
850 nilfs_checkpoint_set_minor(raw_cp);
851
852 nilfs_write_inode_common(sci->sc_root->ifile,
853 &raw_cp->cp_ifile_inode, 1);
854 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
855 return 0;
856
857 failed_ibh:
858 return err;
859 }
860
861 static void nilfs_fill_in_file_bmap(struct inode *ifile,
862 struct nilfs_inode_info *ii)
863
864 {
865 struct buffer_head *ibh;
866 struct nilfs_inode *raw_inode;
867
868 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
869 ibh = ii->i_bh;
870 BUG_ON(!ibh);
871 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
872 ibh);
873 nilfs_bmap_write(ii->i_bmap, raw_inode);
874 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
875 }
876 }
877
878 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
879 {
880 struct nilfs_inode_info *ii;
881
882 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
883 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
884 set_bit(NILFS_I_COLLECTED, &ii->i_state);
885 }
886 }
887
888 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
889 struct the_nilfs *nilfs)
890 {
891 struct buffer_head *bh_sr;
892 struct nilfs_super_root *raw_sr;
893 unsigned isz, srsz;
894
895 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
896 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
897 isz = nilfs->ns_inode_size;
898 srsz = NILFS_SR_BYTES(isz);
899
900 raw_sr->sr_bytes = cpu_to_le16(srsz);
901 raw_sr->sr_nongc_ctime
902 = cpu_to_le64(nilfs_doing_gc() ?
903 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
904 raw_sr->sr_flags = 0;
905
906 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr +
907 NILFS_SR_DAT_OFFSET(isz), 1);
908 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
909 NILFS_SR_CPFILE_OFFSET(isz), 1);
910 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
911 NILFS_SR_SUFILE_OFFSET(isz), 1);
912 memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz);
913 }
914
915 static void nilfs_redirty_inodes(struct list_head *head)
916 {
917 struct nilfs_inode_info *ii;
918
919 list_for_each_entry(ii, head, i_dirty) {
920 if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
921 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
922 }
923 }
924
925 static void nilfs_drop_collected_inodes(struct list_head *head)
926 {
927 struct nilfs_inode_info *ii;
928
929 list_for_each_entry(ii, head, i_dirty) {
930 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
931 continue;
932
933 clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
934 set_bit(NILFS_I_UPDATED, &ii->i_state);
935 }
936 }
937
938 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
939 struct inode *inode,
940 struct list_head *listp,
941 int (*collect)(struct nilfs_sc_info *,
942 struct buffer_head *,
943 struct inode *))
944 {
945 struct buffer_head *bh, *n;
946 int err = 0;
947
948 if (collect) {
949 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
950 list_del_init(&bh->b_assoc_buffers);
951 err = collect(sci, bh, inode);
952 brelse(bh);
953 if (unlikely(err))
954 goto dispose_buffers;
955 }
956 return 0;
957 }
958
959 dispose_buffers:
960 while (!list_empty(listp)) {
961 bh = list_first_entry(listp, struct buffer_head,
962 b_assoc_buffers);
963 list_del_init(&bh->b_assoc_buffers);
964 brelse(bh);
965 }
966 return err;
967 }
968
969 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
970 {
971 /* Remaining number of blocks within segment buffer */
972 return sci->sc_segbuf_nblocks -
973 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
974 }
975
976 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
977 struct inode *inode,
978 struct nilfs_sc_operations *sc_ops)
979 {
980 LIST_HEAD(data_buffers);
981 LIST_HEAD(node_buffers);
982 int err;
983
984 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
985 size_t n, rest = nilfs_segctor_buffer_rest(sci);
986
987 n = nilfs_lookup_dirty_data_buffers(
988 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
989 if (n > rest) {
990 err = nilfs_segctor_apply_buffers(
991 sci, inode, &data_buffers,
992 sc_ops->collect_data);
993 BUG_ON(!err); /* always receive -E2BIG or true error */
994 goto break_or_fail;
995 }
996 }
997 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
998
999 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1000 err = nilfs_segctor_apply_buffers(
1001 sci, inode, &data_buffers, sc_ops->collect_data);
1002 if (unlikely(err)) {
1003 /* dispose node list */
1004 nilfs_segctor_apply_buffers(
1005 sci, inode, &node_buffers, NULL);
1006 goto break_or_fail;
1007 }
1008 sci->sc_stage.flags |= NILFS_CF_NODE;
1009 }
1010 /* Collect node */
1011 err = nilfs_segctor_apply_buffers(
1012 sci, inode, &node_buffers, sc_ops->collect_node);
1013 if (unlikely(err))
1014 goto break_or_fail;
1015
1016 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1017 err = nilfs_segctor_apply_buffers(
1018 sci, inode, &node_buffers, sc_ops->collect_bmap);
1019 if (unlikely(err))
1020 goto break_or_fail;
1021
1022 nilfs_segctor_end_finfo(sci, inode);
1023 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1024
1025 break_or_fail:
1026 return err;
1027 }
1028
1029 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1030 struct inode *inode)
1031 {
1032 LIST_HEAD(data_buffers);
1033 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1034 int err;
1035
1036 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1037 sci->sc_dsync_start,
1038 sci->sc_dsync_end);
1039
1040 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1041 nilfs_collect_file_data);
1042 if (!err) {
1043 nilfs_segctor_end_finfo(sci, inode);
1044 BUG_ON(n > rest);
1045 /* always receive -E2BIG or true error if n > rest */
1046 }
1047 return err;
1048 }
1049
1050 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1051 {
1052 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1053 struct list_head *head;
1054 struct nilfs_inode_info *ii;
1055 size_t ndone;
1056 int err = 0;
1057
1058 switch (sci->sc_stage.scnt) {
1059 case NILFS_ST_INIT:
1060 /* Pre-processes */
1061 sci->sc_stage.flags = 0;
1062
1063 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1064 sci->sc_nblk_inc = 0;
1065 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1066 if (mode == SC_LSEG_DSYNC) {
1067 sci->sc_stage.scnt = NILFS_ST_DSYNC;
1068 goto dsync_mode;
1069 }
1070 }
1071
1072 sci->sc_stage.dirty_file_ptr = NULL;
1073 sci->sc_stage.gc_inode_ptr = NULL;
1074 if (mode == SC_FLUSH_DAT) {
1075 sci->sc_stage.scnt = NILFS_ST_DAT;
1076 goto dat_stage;
1077 }
1078 sci->sc_stage.scnt++; /* Fall through */
1079 case NILFS_ST_GC:
1080 if (nilfs_doing_gc()) {
1081 head = &sci->sc_gc_inodes;
1082 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1083 head, i_dirty);
1084 list_for_each_entry_continue(ii, head, i_dirty) {
1085 err = nilfs_segctor_scan_file(
1086 sci, &ii->vfs_inode,
1087 &nilfs_sc_file_ops);
1088 if (unlikely(err)) {
1089 sci->sc_stage.gc_inode_ptr = list_entry(
1090 ii->i_dirty.prev,
1091 struct nilfs_inode_info,
1092 i_dirty);
1093 goto break_or_fail;
1094 }
1095 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1096 }
1097 sci->sc_stage.gc_inode_ptr = NULL;
1098 }
1099 sci->sc_stage.scnt++; /* Fall through */
1100 case NILFS_ST_FILE:
1101 head = &sci->sc_dirty_files;
1102 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1103 i_dirty);
1104 list_for_each_entry_continue(ii, head, i_dirty) {
1105 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1106
1107 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1108 &nilfs_sc_file_ops);
1109 if (unlikely(err)) {
1110 sci->sc_stage.dirty_file_ptr =
1111 list_entry(ii->i_dirty.prev,
1112 struct nilfs_inode_info,
1113 i_dirty);
1114 goto break_or_fail;
1115 }
1116 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1117 /* XXX: required ? */
1118 }
1119 sci->sc_stage.dirty_file_ptr = NULL;
1120 if (mode == SC_FLUSH_FILE) {
1121 sci->sc_stage.scnt = NILFS_ST_DONE;
1122 return 0;
1123 }
1124 sci->sc_stage.scnt++;
1125 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1126 /* Fall through */
1127 case NILFS_ST_IFILE:
1128 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile,
1129 &nilfs_sc_file_ops);
1130 if (unlikely(err))
1131 break;
1132 sci->sc_stage.scnt++;
1133 /* Creating a checkpoint */
1134 err = nilfs_segctor_create_checkpoint(sci);
1135 if (unlikely(err))
1136 break;
1137 /* Fall through */
1138 case NILFS_ST_CPFILE:
1139 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1140 &nilfs_sc_file_ops);
1141 if (unlikely(err))
1142 break;
1143 sci->sc_stage.scnt++; /* Fall through */
1144 case NILFS_ST_SUFILE:
1145 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1146 sci->sc_nfreesegs, &ndone);
1147 if (unlikely(err)) {
1148 nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1149 sci->sc_freesegs, ndone,
1150 NULL);
1151 break;
1152 }
1153 sci->sc_stage.flags |= NILFS_CF_SUFREED;
1154
1155 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1156 &nilfs_sc_file_ops);
1157 if (unlikely(err))
1158 break;
1159 sci->sc_stage.scnt++; /* Fall through */
1160 case NILFS_ST_DAT:
1161 dat_stage:
1162 err = nilfs_segctor_scan_file(sci, nilfs->ns_dat,
1163 &nilfs_sc_dat_ops);
1164 if (unlikely(err))
1165 break;
1166 if (mode == SC_FLUSH_DAT) {
1167 sci->sc_stage.scnt = NILFS_ST_DONE;
1168 return 0;
1169 }
1170 sci->sc_stage.scnt++; /* Fall through */
1171 case NILFS_ST_SR:
1172 if (mode == SC_LSEG_SR) {
1173 /* Appending a super root */
1174 err = nilfs_segctor_add_super_root(sci);
1175 if (unlikely(err))
1176 break;
1177 }
1178 /* End of a logical segment */
1179 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1180 sci->sc_stage.scnt = NILFS_ST_DONE;
1181 return 0;
1182 case NILFS_ST_DSYNC:
1183 dsync_mode:
1184 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1185 ii = sci->sc_dsync_inode;
1186 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1187 break;
1188
1189 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1190 if (unlikely(err))
1191 break;
1192 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1193 sci->sc_stage.scnt = NILFS_ST_DONE;
1194 return 0;
1195 case NILFS_ST_DONE:
1196 return 0;
1197 default:
1198 BUG();
1199 }
1200
1201 break_or_fail:
1202 return err;
1203 }
1204
1205 /**
1206 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1207 * @sci: nilfs_sc_info
1208 * @nilfs: nilfs object
1209 */
1210 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1211 struct the_nilfs *nilfs)
1212 {
1213 struct nilfs_segment_buffer *segbuf, *prev;
1214 __u64 nextnum;
1215 int err, alloc = 0;
1216
1217 segbuf = nilfs_segbuf_new(sci->sc_super);
1218 if (unlikely(!segbuf))
1219 return -ENOMEM;
1220
1221 if (list_empty(&sci->sc_write_logs)) {
1222 nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1223 nilfs->ns_pseg_offset, nilfs);
1224 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1225 nilfs_shift_to_next_segment(nilfs);
1226 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1227 }
1228
1229 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1230 nextnum = nilfs->ns_nextnum;
1231
1232 if (nilfs->ns_segnum == nilfs->ns_nextnum)
1233 /* Start from the head of a new full segment */
1234 alloc++;
1235 } else {
1236 /* Continue logs */
1237 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1238 nilfs_segbuf_map_cont(segbuf, prev);
1239 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1240 nextnum = prev->sb_nextnum;
1241
1242 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1243 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1244 segbuf->sb_sum.seg_seq++;
1245 alloc++;
1246 }
1247 }
1248
1249 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1250 if (err)
1251 goto failed;
1252
1253 if (alloc) {
1254 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1255 if (err)
1256 goto failed;
1257 }
1258 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1259
1260 BUG_ON(!list_empty(&sci->sc_segbufs));
1261 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1262 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1263 return 0;
1264
1265 failed:
1266 nilfs_segbuf_free(segbuf);
1267 return err;
1268 }
1269
1270 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1271 struct the_nilfs *nilfs, int nadd)
1272 {
1273 struct nilfs_segment_buffer *segbuf, *prev;
1274 struct inode *sufile = nilfs->ns_sufile;
1275 __u64 nextnextnum;
1276 LIST_HEAD(list);
1277 int err, ret, i;
1278
1279 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1280 /*
1281 * Since the segment specified with nextnum might be allocated during
1282 * the previous construction, the buffer including its segusage may
1283 * not be dirty. The following call ensures that the buffer is dirty
1284 * and will pin the buffer on memory until the sufile is written.
1285 */
1286 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1287 if (unlikely(err))
1288 return err;
1289
1290 for (i = 0; i < nadd; i++) {
1291 /* extend segment info */
1292 err = -ENOMEM;
1293 segbuf = nilfs_segbuf_new(sci->sc_super);
1294 if (unlikely(!segbuf))
1295 goto failed;
1296
1297 /* map this buffer to region of segment on-disk */
1298 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1299 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1300
1301 /* allocate the next next full segment */
1302 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1303 if (unlikely(err))
1304 goto failed_segbuf;
1305
1306 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1307 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1308
1309 list_add_tail(&segbuf->sb_list, &list);
1310 prev = segbuf;
1311 }
1312 list_splice_tail(&list, &sci->sc_segbufs);
1313 return 0;
1314
1315 failed_segbuf:
1316 nilfs_segbuf_free(segbuf);
1317 failed:
1318 list_for_each_entry(segbuf, &list, sb_list) {
1319 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1320 WARN_ON(ret); /* never fails */
1321 }
1322 nilfs_destroy_logs(&list);
1323 return err;
1324 }
1325
1326 static void nilfs_free_incomplete_logs(struct list_head *logs,
1327 struct the_nilfs *nilfs)
1328 {
1329 struct nilfs_segment_buffer *segbuf, *prev;
1330 struct inode *sufile = nilfs->ns_sufile;
1331 int ret;
1332
1333 segbuf = NILFS_FIRST_SEGBUF(logs);
1334 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1335 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1336 WARN_ON(ret); /* never fails */
1337 }
1338 if (atomic_read(&segbuf->sb_err)) {
1339 /* Case 1: The first segment failed */
1340 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1341 /* Case 1a: Partial segment appended into an existing
1342 segment */
1343 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1344 segbuf->sb_fseg_end);
1345 else /* Case 1b: New full segment */
1346 set_nilfs_discontinued(nilfs);
1347 }
1348
1349 prev = segbuf;
1350 list_for_each_entry_continue(segbuf, logs, sb_list) {
1351 if (prev->sb_nextnum != segbuf->sb_nextnum) {
1352 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1353 WARN_ON(ret); /* never fails */
1354 }
1355 if (atomic_read(&segbuf->sb_err) &&
1356 segbuf->sb_segnum != nilfs->ns_nextnum)
1357 /* Case 2: extended segment (!= next) failed */
1358 nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1359 prev = segbuf;
1360 }
1361 }
1362
1363 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1364 struct inode *sufile)
1365 {
1366 struct nilfs_segment_buffer *segbuf;
1367 unsigned long live_blocks;
1368 int ret;
1369
1370 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1371 live_blocks = segbuf->sb_sum.nblocks +
1372 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1373 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1374 live_blocks,
1375 sci->sc_seg_ctime);
1376 WARN_ON(ret); /* always succeed because the segusage is dirty */
1377 }
1378 }
1379
1380 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1381 {
1382 struct nilfs_segment_buffer *segbuf;
1383 int ret;
1384
1385 segbuf = NILFS_FIRST_SEGBUF(logs);
1386 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1387 segbuf->sb_pseg_start -
1388 segbuf->sb_fseg_start, 0);
1389 WARN_ON(ret); /* always succeed because the segusage is dirty */
1390
1391 list_for_each_entry_continue(segbuf, logs, sb_list) {
1392 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1393 0, 0);
1394 WARN_ON(ret); /* always succeed */
1395 }
1396 }
1397
1398 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1399 struct nilfs_segment_buffer *last,
1400 struct inode *sufile)
1401 {
1402 struct nilfs_segment_buffer *segbuf = last;
1403 int ret;
1404
1405 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1406 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1407 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1408 WARN_ON(ret);
1409 }
1410 nilfs_truncate_logs(&sci->sc_segbufs, last);
1411 }
1412
1413
1414 static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1415 struct the_nilfs *nilfs, int mode)
1416 {
1417 struct nilfs_cstage prev_stage = sci->sc_stage;
1418 int err, nadd = 1;
1419
1420 /* Collection retry loop */
1421 for (;;) {
1422 sci->sc_nblk_this_inc = 0;
1423 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1424
1425 err = nilfs_segctor_reset_segment_buffer(sci);
1426 if (unlikely(err))
1427 goto failed;
1428
1429 err = nilfs_segctor_collect_blocks(sci, mode);
1430 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1431 if (!err)
1432 break;
1433
1434 if (unlikely(err != -E2BIG))
1435 goto failed;
1436
1437 /* The current segment is filled up */
1438 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
1439 break;
1440
1441 nilfs_clear_logs(&sci->sc_segbufs);
1442
1443 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1444 if (unlikely(err))
1445 return err;
1446
1447 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1448 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1449 sci->sc_freesegs,
1450 sci->sc_nfreesegs,
1451 NULL);
1452 WARN_ON(err); /* do not happen */
1453 }
1454 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1455 sci->sc_stage = prev_stage;
1456 }
1457 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1458 return 0;
1459
1460 failed:
1461 return err;
1462 }
1463
1464 static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1465 struct buffer_head *new_bh)
1466 {
1467 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1468
1469 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1470 /* The caller must release old_bh */
1471 }
1472
1473 static int
1474 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1475 struct nilfs_segment_buffer *segbuf,
1476 int mode)
1477 {
1478 struct inode *inode = NULL;
1479 sector_t blocknr;
1480 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1481 unsigned long nblocks = 0, ndatablk = 0;
1482 struct nilfs_sc_operations *sc_op = NULL;
1483 struct nilfs_segsum_pointer ssp;
1484 struct nilfs_finfo *finfo = NULL;
1485 union nilfs_binfo binfo;
1486 struct buffer_head *bh, *bh_org;
1487 ino_t ino = 0;
1488 int err = 0;
1489
1490 if (!nfinfo)
1491 goto out;
1492
1493 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1494 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1495 ssp.offset = sizeof(struct nilfs_segment_summary);
1496
1497 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1498 if (bh == segbuf->sb_super_root)
1499 break;
1500 if (!finfo) {
1501 finfo = nilfs_segctor_map_segsum_entry(
1502 sci, &ssp, sizeof(*finfo));
1503 ino = le64_to_cpu(finfo->fi_ino);
1504 nblocks = le32_to_cpu(finfo->fi_nblocks);
1505 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1506
1507 inode = bh->b_page->mapping->host;
1508
1509 if (mode == SC_LSEG_DSYNC)
1510 sc_op = &nilfs_sc_dsync_ops;
1511 else if (ino == NILFS_DAT_INO)
1512 sc_op = &nilfs_sc_dat_ops;
1513 else /* file blocks */
1514 sc_op = &nilfs_sc_file_ops;
1515 }
1516 bh_org = bh;
1517 get_bh(bh_org);
1518 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1519 &binfo);
1520 if (bh != bh_org)
1521 nilfs_list_replace_buffer(bh_org, bh);
1522 brelse(bh_org);
1523 if (unlikely(err))
1524 goto failed_bmap;
1525
1526 if (ndatablk > 0)
1527 sc_op->write_data_binfo(sci, &ssp, &binfo);
1528 else
1529 sc_op->write_node_binfo(sci, &ssp, &binfo);
1530
1531 blocknr++;
1532 if (--nblocks == 0) {
1533 finfo = NULL;
1534 if (--nfinfo == 0)
1535 break;
1536 } else if (ndatablk > 0)
1537 ndatablk--;
1538 }
1539 out:
1540 return 0;
1541
1542 failed_bmap:
1543 return err;
1544 }
1545
1546 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1547 {
1548 struct nilfs_segment_buffer *segbuf;
1549 int err;
1550
1551 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1552 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1553 if (unlikely(err))
1554 return err;
1555 nilfs_segbuf_fill_in_segsum(segbuf);
1556 }
1557 return 0;
1558 }
1559
1560 static void nilfs_begin_page_io(struct page *page)
1561 {
1562 if (!page || PageWriteback(page))
1563 /* For split b-tree node pages, this function may be called
1564 twice. We ignore the 2nd or later calls by this check. */
1565 return;
1566
1567 lock_page(page);
1568 clear_page_dirty_for_io(page);
1569 set_page_writeback(page);
1570 unlock_page(page);
1571 }
1572
1573 static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
1574 {
1575 struct nilfs_segment_buffer *segbuf;
1576 struct page *bd_page = NULL, *fs_page = NULL;
1577
1578 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1579 struct buffer_head *bh;
1580
1581 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1582 b_assoc_buffers) {
1583 set_buffer_async_write(bh);
1584 if (bh->b_page != bd_page) {
1585 if (bd_page) {
1586 lock_page(bd_page);
1587 clear_page_dirty_for_io(bd_page);
1588 set_page_writeback(bd_page);
1589 unlock_page(bd_page);
1590 }
1591 bd_page = bh->b_page;
1592 }
1593 }
1594
1595 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1596 b_assoc_buffers) {
1597 set_buffer_async_write(bh);
1598 if (bh == segbuf->sb_super_root) {
1599 if (bh->b_page != bd_page) {
1600 lock_page(bd_page);
1601 clear_page_dirty_for_io(bd_page);
1602 set_page_writeback(bd_page);
1603 unlock_page(bd_page);
1604 bd_page = bh->b_page;
1605 }
1606 break;
1607 }
1608 if (bh->b_page != fs_page) {
1609 nilfs_begin_page_io(fs_page);
1610 fs_page = bh->b_page;
1611 }
1612 }
1613 }
1614 if (bd_page) {
1615 lock_page(bd_page);
1616 clear_page_dirty_for_io(bd_page);
1617 set_page_writeback(bd_page);
1618 unlock_page(bd_page);
1619 }
1620 nilfs_begin_page_io(fs_page);
1621 }
1622
1623 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1624 struct the_nilfs *nilfs)
1625 {
1626 int ret;
1627
1628 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1629 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1630 return ret;
1631 }
1632
1633 static void nilfs_end_page_io(struct page *page, int err)
1634 {
1635 if (!page)
1636 return;
1637
1638 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
1639 /*
1640 * For b-tree node pages, this function may be called twice
1641 * or more because they might be split in a segment.
1642 */
1643 if (PageDirty(page)) {
1644 /*
1645 * For pages holding split b-tree node buffers, dirty
1646 * flag on the buffers may be cleared discretely.
1647 * In that case, the page is once redirtied for
1648 * remaining buffers, and it must be cancelled if
1649 * all the buffers get cleaned later.
1650 */
1651 lock_page(page);
1652 if (nilfs_page_buffers_clean(page))
1653 __nilfs_clear_page_dirty(page);
1654 unlock_page(page);
1655 }
1656 return;
1657 }
1658
1659 if (!err) {
1660 if (!nilfs_page_buffers_clean(page))
1661 __set_page_dirty_nobuffers(page);
1662 ClearPageError(page);
1663 } else {
1664 __set_page_dirty_nobuffers(page);
1665 SetPageError(page);
1666 }
1667
1668 end_page_writeback(page);
1669 }
1670
1671 static void nilfs_abort_logs(struct list_head *logs, int err)
1672 {
1673 struct nilfs_segment_buffer *segbuf;
1674 struct page *bd_page = NULL, *fs_page = NULL;
1675 struct buffer_head *bh;
1676
1677 if (list_empty(logs))
1678 return;
1679
1680 list_for_each_entry(segbuf, logs, sb_list) {
1681 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1682 b_assoc_buffers) {
1683 clear_buffer_async_write(bh);
1684 if (bh->b_page != bd_page) {
1685 if (bd_page)
1686 end_page_writeback(bd_page);
1687 bd_page = bh->b_page;
1688 }
1689 }
1690
1691 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1692 b_assoc_buffers) {
1693 clear_buffer_async_write(bh);
1694 if (bh == segbuf->sb_super_root) {
1695 if (bh->b_page != bd_page) {
1696 end_page_writeback(bd_page);
1697 bd_page = bh->b_page;
1698 }
1699 break;
1700 }
1701 if (bh->b_page != fs_page) {
1702 nilfs_end_page_io(fs_page, err);
1703 fs_page = bh->b_page;
1704 }
1705 }
1706 }
1707 if (bd_page)
1708 end_page_writeback(bd_page);
1709
1710 nilfs_end_page_io(fs_page, err);
1711 }
1712
1713 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1714 struct the_nilfs *nilfs, int err)
1715 {
1716 LIST_HEAD(logs);
1717 int ret;
1718
1719 list_splice_tail_init(&sci->sc_write_logs, &logs);
1720 ret = nilfs_wait_on_logs(&logs);
1721 nilfs_abort_logs(&logs, ret ? : err);
1722
1723 list_splice_tail_init(&sci->sc_segbufs, &logs);
1724 nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1725 nilfs_free_incomplete_logs(&logs, nilfs);
1726
1727 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1728 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1729 sci->sc_freesegs,
1730 sci->sc_nfreesegs,
1731 NULL);
1732 WARN_ON(ret); /* do not happen */
1733 }
1734
1735 nilfs_destroy_logs(&logs);
1736 }
1737
1738 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1739 struct nilfs_segment_buffer *segbuf)
1740 {
1741 nilfs->ns_segnum = segbuf->sb_segnum;
1742 nilfs->ns_nextnum = segbuf->sb_nextnum;
1743 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1744 + segbuf->sb_sum.nblocks;
1745 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1746 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1747 }
1748
1749 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1750 {
1751 struct nilfs_segment_buffer *segbuf;
1752 struct page *bd_page = NULL, *fs_page = NULL;
1753 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1754 int update_sr = false;
1755
1756 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1757 struct buffer_head *bh;
1758
1759 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1760 b_assoc_buffers) {
1761 set_buffer_uptodate(bh);
1762 clear_buffer_dirty(bh);
1763 clear_buffer_async_write(bh);
1764 if (bh->b_page != bd_page) {
1765 if (bd_page)
1766 end_page_writeback(bd_page);
1767 bd_page = bh->b_page;
1768 }
1769 }
1770 /*
1771 * We assume that the buffers which belong to the same page
1772 * continue over the buffer list.
1773 * Under this assumption, the last BHs of pages is
1774 * identifiable by the discontinuity of bh->b_page
1775 * (page != fs_page).
1776 *
1777 * For B-tree node blocks, however, this assumption is not
1778 * guaranteed. The cleanup code of B-tree node pages needs
1779 * special care.
1780 */
1781 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1782 b_assoc_buffers) {
1783 set_buffer_uptodate(bh);
1784 clear_buffer_dirty(bh);
1785 clear_buffer_async_write(bh);
1786 clear_buffer_delay(bh);
1787 clear_buffer_nilfs_volatile(bh);
1788 clear_buffer_nilfs_redirected(bh);
1789 if (bh == segbuf->sb_super_root) {
1790 if (bh->b_page != bd_page) {
1791 end_page_writeback(bd_page);
1792 bd_page = bh->b_page;
1793 }
1794 update_sr = true;
1795 break;
1796 }
1797 if (bh->b_page != fs_page) {
1798 nilfs_end_page_io(fs_page, 0);
1799 fs_page = bh->b_page;
1800 }
1801 }
1802
1803 if (!nilfs_segbuf_simplex(segbuf)) {
1804 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
1805 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1806 sci->sc_lseg_stime = jiffies;
1807 }
1808 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
1809 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1810 }
1811 }
1812 /*
1813 * Since pages may continue over multiple segment buffers,
1814 * end of the last page must be checked outside of the loop.
1815 */
1816 if (bd_page)
1817 end_page_writeback(bd_page);
1818
1819 nilfs_end_page_io(fs_page, 0);
1820
1821 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1822
1823 if (nilfs_doing_gc())
1824 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1825 else
1826 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1827
1828 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1829
1830 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1831 nilfs_set_next_segment(nilfs, segbuf);
1832
1833 if (update_sr) {
1834 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
1835 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
1836
1837 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
1838 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1839 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1840 nilfs_segctor_clear_metadata_dirty(sci);
1841 } else
1842 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1843 }
1844
1845 static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
1846 {
1847 int ret;
1848
1849 ret = nilfs_wait_on_logs(&sci->sc_write_logs);
1850 if (!ret) {
1851 nilfs_segctor_complete_write(sci);
1852 nilfs_destroy_logs(&sci->sc_write_logs);
1853 }
1854 return ret;
1855 }
1856
1857 static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci,
1858 struct the_nilfs *nilfs)
1859 {
1860 struct nilfs_inode_info *ii, *n;
1861 struct inode *ifile = sci->sc_root->ifile;
1862
1863 spin_lock(&nilfs->ns_inode_lock);
1864 retry:
1865 list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) {
1866 if (!ii->i_bh) {
1867 struct buffer_head *ibh;
1868 int err;
1869
1870 spin_unlock(&nilfs->ns_inode_lock);
1871 err = nilfs_ifile_get_inode_block(
1872 ifile, ii->vfs_inode.i_ino, &ibh);
1873 if (unlikely(err)) {
1874 nilfs_warning(sci->sc_super, __func__,
1875 "failed to get inode block.\n");
1876 return err;
1877 }
1878 mark_buffer_dirty(ibh);
1879 nilfs_mdt_mark_dirty(ifile);
1880 spin_lock(&nilfs->ns_inode_lock);
1881 if (likely(!ii->i_bh))
1882 ii->i_bh = ibh;
1883 else
1884 brelse(ibh);
1885 goto retry;
1886 }
1887
1888 clear_bit(NILFS_I_QUEUED, &ii->i_state);
1889 set_bit(NILFS_I_BUSY, &ii->i_state);
1890 list_move_tail(&ii->i_dirty, &sci->sc_dirty_files);
1891 }
1892 spin_unlock(&nilfs->ns_inode_lock);
1893
1894 return 0;
1895 }
1896
1897 static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
1898 struct the_nilfs *nilfs)
1899 {
1900 struct nilfs_transaction_info *ti = current->journal_info;
1901 struct nilfs_inode_info *ii, *n;
1902
1903 spin_lock(&nilfs->ns_inode_lock);
1904 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
1905 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
1906 test_bit(NILFS_I_DIRTY, &ii->i_state))
1907 continue;
1908
1909 clear_bit(NILFS_I_BUSY, &ii->i_state);
1910 brelse(ii->i_bh);
1911 ii->i_bh = NULL;
1912 list_move_tail(&ii->i_dirty, &ti->ti_garbage);
1913 }
1914 spin_unlock(&nilfs->ns_inode_lock);
1915 }
1916
1917 /*
1918 * Main procedure of segment constructor
1919 */
1920 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
1921 {
1922 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1923 int err;
1924
1925 sci->sc_stage.scnt = NILFS_ST_INIT;
1926 sci->sc_cno = nilfs->ns_cno;
1927
1928 err = nilfs_segctor_collect_dirty_files(sci, nilfs);
1929 if (unlikely(err))
1930 goto out;
1931
1932 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
1933 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1934
1935 if (nilfs_segctor_clean(sci))
1936 goto out;
1937
1938 do {
1939 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
1940
1941 err = nilfs_segctor_begin_construction(sci, nilfs);
1942 if (unlikely(err))
1943 goto out;
1944
1945 /* Update time stamp */
1946 sci->sc_seg_ctime = get_seconds();
1947
1948 err = nilfs_segctor_collect(sci, nilfs, mode);
1949 if (unlikely(err))
1950 goto failed;
1951
1952 /* Avoid empty segment */
1953 if (sci->sc_stage.scnt == NILFS_ST_DONE &&
1954 nilfs_segbuf_empty(sci->sc_curseg)) {
1955 nilfs_segctor_abort_construction(sci, nilfs, 1);
1956 goto out;
1957 }
1958
1959 err = nilfs_segctor_assign(sci, mode);
1960 if (unlikely(err))
1961 goto failed;
1962
1963 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
1964 nilfs_segctor_fill_in_file_bmap(sci);
1965
1966 if (mode == SC_LSEG_SR &&
1967 sci->sc_stage.scnt >= NILFS_ST_CPFILE) {
1968 err = nilfs_segctor_fill_in_checkpoint(sci);
1969 if (unlikely(err))
1970 goto failed_to_write;
1971
1972 nilfs_segctor_fill_in_super_root(sci, nilfs);
1973 }
1974 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
1975
1976 /* Write partial segments */
1977 nilfs_segctor_prepare_write(sci);
1978
1979 nilfs_add_checksums_on_logs(&sci->sc_segbufs,
1980 nilfs->ns_crc_seed);
1981
1982 err = nilfs_segctor_write(sci, nilfs);
1983 if (unlikely(err))
1984 goto failed_to_write;
1985
1986 if (sci->sc_stage.scnt == NILFS_ST_DONE ||
1987 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
1988 /*
1989 * At this point, we avoid double buffering
1990 * for blocksize < pagesize because page dirty
1991 * flag is turned off during write and dirty
1992 * buffers are not properly collected for
1993 * pages crossing over segments.
1994 */
1995 err = nilfs_segctor_wait(sci);
1996 if (err)
1997 goto failed_to_write;
1998 }
1999 } while (sci->sc_stage.scnt != NILFS_ST_DONE);
2000
2001 out:
2002 nilfs_segctor_drop_written_files(sci, nilfs);
2003 return err;
2004
2005 failed_to_write:
2006 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2007 nilfs_redirty_inodes(&sci->sc_dirty_files);
2008
2009 failed:
2010 if (nilfs_doing_gc())
2011 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2012 nilfs_segctor_abort_construction(sci, nilfs, err);
2013 goto out;
2014 }
2015
2016 /**
2017 * nilfs_segctor_start_timer - set timer of background write
2018 * @sci: nilfs_sc_info
2019 *
2020 * If the timer has already been set, it ignores the new request.
2021 * This function MUST be called within a section locking the segment
2022 * semaphore.
2023 */
2024 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2025 {
2026 spin_lock(&sci->sc_state_lock);
2027 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2028 sci->sc_timer.expires = jiffies + sci->sc_interval;
2029 add_timer(&sci->sc_timer);
2030 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2031 }
2032 spin_unlock(&sci->sc_state_lock);
2033 }
2034
2035 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2036 {
2037 spin_lock(&sci->sc_state_lock);
2038 if (!(sci->sc_flush_request & (1 << bn))) {
2039 unsigned long prev_req = sci->sc_flush_request;
2040
2041 sci->sc_flush_request |= (1 << bn);
2042 if (!prev_req)
2043 wake_up(&sci->sc_wait_daemon);
2044 }
2045 spin_unlock(&sci->sc_state_lock);
2046 }
2047
2048 /**
2049 * nilfs_flush_segment - trigger a segment construction for resource control
2050 * @sb: super block
2051 * @ino: inode number of the file to be flushed out.
2052 */
2053 void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2054 {
2055 struct the_nilfs *nilfs = sb->s_fs_info;
2056 struct nilfs_sc_info *sci = nilfs->ns_writer;
2057
2058 if (!sci || nilfs_doing_construction())
2059 return;
2060 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2061 /* assign bit 0 to data files */
2062 }
2063
2064 struct nilfs_segctor_wait_request {
2065 wait_queue_t wq;
2066 __u32 seq;
2067 int err;
2068 atomic_t done;
2069 };
2070
2071 static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2072 {
2073 struct nilfs_segctor_wait_request wait_req;
2074 int err = 0;
2075
2076 spin_lock(&sci->sc_state_lock);
2077 init_wait(&wait_req.wq);
2078 wait_req.err = 0;
2079 atomic_set(&wait_req.done, 0);
2080 wait_req.seq = ++sci->sc_seq_request;
2081 spin_unlock(&sci->sc_state_lock);
2082
2083 init_waitqueue_entry(&wait_req.wq, current);
2084 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2085 set_current_state(TASK_INTERRUPTIBLE);
2086 wake_up(&sci->sc_wait_daemon);
2087
2088 for (;;) {
2089 if (atomic_read(&wait_req.done)) {
2090 err = wait_req.err;
2091 break;
2092 }
2093 if (!signal_pending(current)) {
2094 schedule();
2095 continue;
2096 }
2097 err = -ERESTARTSYS;
2098 break;
2099 }
2100 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2101 return err;
2102 }
2103
2104 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2105 {
2106 struct nilfs_segctor_wait_request *wrq, *n;
2107 unsigned long flags;
2108
2109 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2110 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2111 wq.task_list) {
2112 if (!atomic_read(&wrq->done) &&
2113 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2114 wrq->err = err;
2115 atomic_set(&wrq->done, 1);
2116 }
2117 if (atomic_read(&wrq->done)) {
2118 wrq->wq.func(&wrq->wq,
2119 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2120 0, NULL);
2121 }
2122 }
2123 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2124 }
2125
2126 /**
2127 * nilfs_construct_segment - construct a logical segment
2128 * @sb: super block
2129 *
2130 * Return Value: On success, 0 is retured. On errors, one of the following
2131 * negative error code is returned.
2132 *
2133 * %-EROFS - Read only filesystem.
2134 *
2135 * %-EIO - I/O error
2136 *
2137 * %-ENOSPC - No space left on device (only in a panic state).
2138 *
2139 * %-ERESTARTSYS - Interrupted.
2140 *
2141 * %-ENOMEM - Insufficient memory available.
2142 */
2143 int nilfs_construct_segment(struct super_block *sb)
2144 {
2145 struct the_nilfs *nilfs = sb->s_fs_info;
2146 struct nilfs_sc_info *sci = nilfs->ns_writer;
2147 struct nilfs_transaction_info *ti;
2148 int err;
2149
2150 if (!sci)
2151 return -EROFS;
2152
2153 /* A call inside transactions causes a deadlock. */
2154 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2155
2156 err = nilfs_segctor_sync(sci);
2157 return err;
2158 }
2159
2160 /**
2161 * nilfs_construct_dsync_segment - construct a data-only logical segment
2162 * @sb: super block
2163 * @inode: inode whose data blocks should be written out
2164 * @start: start byte offset
2165 * @end: end byte offset (inclusive)
2166 *
2167 * Return Value: On success, 0 is retured. On errors, one of the following
2168 * negative error code is returned.
2169 *
2170 * %-EROFS - Read only filesystem.
2171 *
2172 * %-EIO - I/O error
2173 *
2174 * %-ENOSPC - No space left on device (only in a panic state).
2175 *
2176 * %-ERESTARTSYS - Interrupted.
2177 *
2178 * %-ENOMEM - Insufficient memory available.
2179 */
2180 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2181 loff_t start, loff_t end)
2182 {
2183 struct the_nilfs *nilfs = sb->s_fs_info;
2184 struct nilfs_sc_info *sci = nilfs->ns_writer;
2185 struct nilfs_inode_info *ii;
2186 struct nilfs_transaction_info ti;
2187 int err = 0;
2188
2189 if (!sci)
2190 return -EROFS;
2191
2192 nilfs_transaction_lock(sb, &ti, 0);
2193
2194 ii = NILFS_I(inode);
2195 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
2196 nilfs_test_opt(nilfs, STRICT_ORDER) ||
2197 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2198 nilfs_discontinued(nilfs)) {
2199 nilfs_transaction_unlock(sb);
2200 err = nilfs_segctor_sync(sci);
2201 return err;
2202 }
2203
2204 spin_lock(&nilfs->ns_inode_lock);
2205 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2206 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2207 spin_unlock(&nilfs->ns_inode_lock);
2208 nilfs_transaction_unlock(sb);
2209 return 0;
2210 }
2211 spin_unlock(&nilfs->ns_inode_lock);
2212 sci->sc_dsync_inode = ii;
2213 sci->sc_dsync_start = start;
2214 sci->sc_dsync_end = end;
2215
2216 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2217
2218 nilfs_transaction_unlock(sb);
2219 return err;
2220 }
2221
2222 #define FLUSH_FILE_BIT (0x1) /* data file only */
2223 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2224
2225 /**
2226 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2227 * @sci: segment constructor object
2228 */
2229 static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2230 {
2231 spin_lock(&sci->sc_state_lock);
2232 sci->sc_seq_accepted = sci->sc_seq_request;
2233 spin_unlock(&sci->sc_state_lock);
2234 del_timer_sync(&sci->sc_timer);
2235 }
2236
2237 /**
2238 * nilfs_segctor_notify - notify the result of request to caller threads
2239 * @sci: segment constructor object
2240 * @mode: mode of log forming
2241 * @err: error code to be notified
2242 */
2243 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2244 {
2245 /* Clear requests (even when the construction failed) */
2246 spin_lock(&sci->sc_state_lock);
2247
2248 if (mode == SC_LSEG_SR) {
2249 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2250 sci->sc_seq_done = sci->sc_seq_accepted;
2251 nilfs_segctor_wakeup(sci, err);
2252 sci->sc_flush_request = 0;
2253 } else {
2254 if (mode == SC_FLUSH_FILE)
2255 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2256 else if (mode == SC_FLUSH_DAT)
2257 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2258
2259 /* re-enable timer if checkpoint creation was not done */
2260 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2261 time_before(jiffies, sci->sc_timer.expires))
2262 add_timer(&sci->sc_timer);
2263 }
2264 spin_unlock(&sci->sc_state_lock);
2265 }
2266
2267 /**
2268 * nilfs_segctor_construct - form logs and write them to disk
2269 * @sci: segment constructor object
2270 * @mode: mode of log forming
2271 */
2272 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2273 {
2274 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2275 struct nilfs_super_block **sbp;
2276 int err = 0;
2277
2278 nilfs_segctor_accept(sci);
2279
2280 if (nilfs_discontinued(nilfs))
2281 mode = SC_LSEG_SR;
2282 if (!nilfs_segctor_confirm(sci))
2283 err = nilfs_segctor_do_construct(sci, mode);
2284
2285 if (likely(!err)) {
2286 if (mode != SC_FLUSH_DAT)
2287 atomic_set(&nilfs->ns_ndirtyblks, 0);
2288 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2289 nilfs_discontinued(nilfs)) {
2290 down_write(&nilfs->ns_sem);
2291 err = -EIO;
2292 sbp = nilfs_prepare_super(sci->sc_super,
2293 nilfs_sb_will_flip(nilfs));
2294 if (likely(sbp)) {
2295 nilfs_set_log_cursor(sbp[0], nilfs);
2296 err = nilfs_commit_super(sci->sc_super,
2297 NILFS_SB_COMMIT);
2298 }
2299 up_write(&nilfs->ns_sem);
2300 }
2301 }
2302
2303 nilfs_segctor_notify(sci, mode, err);
2304 return err;
2305 }
2306
2307 static void nilfs_construction_timeout(unsigned long data)
2308 {
2309 struct task_struct *p = (struct task_struct *)data;
2310 wake_up_process(p);
2311 }
2312
2313 static void
2314 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2315 {
2316 struct nilfs_inode_info *ii, *n;
2317
2318 list_for_each_entry_safe(ii, n, head, i_dirty) {
2319 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2320 continue;
2321 list_del_init(&ii->i_dirty);
2322 truncate_inode_pages(&ii->vfs_inode.i_data, 0);
2323 nilfs_btnode_cache_clear(&ii->i_btnode_cache);
2324 iput(&ii->vfs_inode);
2325 }
2326 }
2327
2328 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2329 void **kbufs)
2330 {
2331 struct the_nilfs *nilfs = sb->s_fs_info;
2332 struct nilfs_sc_info *sci = nilfs->ns_writer;
2333 struct nilfs_transaction_info ti;
2334 int err;
2335
2336 if (unlikely(!sci))
2337 return -EROFS;
2338
2339 nilfs_transaction_lock(sb, &ti, 1);
2340
2341 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2342 if (unlikely(err))
2343 goto out_unlock;
2344
2345 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2346 if (unlikely(err)) {
2347 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2348 goto out_unlock;
2349 }
2350
2351 sci->sc_freesegs = kbufs[4];
2352 sci->sc_nfreesegs = argv[4].v_nmembs;
2353 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2354
2355 for (;;) {
2356 err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2357 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2358
2359 if (likely(!err))
2360 break;
2361
2362 nilfs_warning(sb, __func__,
2363 "segment construction failed. (err=%d)", err);
2364 set_current_state(TASK_INTERRUPTIBLE);
2365 schedule_timeout(sci->sc_interval);
2366 }
2367 if (nilfs_test_opt(nilfs, DISCARD)) {
2368 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2369 sci->sc_nfreesegs);
2370 if (ret) {
2371 printk(KERN_WARNING
2372 "NILFS warning: error %d on discard request, "
2373 "turning discards off for the device\n", ret);
2374 nilfs_clear_opt(nilfs, DISCARD);
2375 }
2376 }
2377
2378 out_unlock:
2379 sci->sc_freesegs = NULL;
2380 sci->sc_nfreesegs = 0;
2381 nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2382 nilfs_transaction_unlock(sb);
2383 return err;
2384 }
2385
2386 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2387 {
2388 struct nilfs_transaction_info ti;
2389
2390 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2391 nilfs_segctor_construct(sci, mode);
2392
2393 /*
2394 * Unclosed segment should be retried. We do this using sc_timer.
2395 * Timeout of sc_timer will invoke complete construction which leads
2396 * to close the current logical segment.
2397 */
2398 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2399 nilfs_segctor_start_timer(sci);
2400
2401 nilfs_transaction_unlock(sci->sc_super);
2402 }
2403
2404 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2405 {
2406 int mode = 0;
2407 int err;
2408
2409 spin_lock(&sci->sc_state_lock);
2410 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2411 SC_FLUSH_DAT : SC_FLUSH_FILE;
2412 spin_unlock(&sci->sc_state_lock);
2413
2414 if (mode) {
2415 err = nilfs_segctor_do_construct(sci, mode);
2416
2417 spin_lock(&sci->sc_state_lock);
2418 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2419 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2420 spin_unlock(&sci->sc_state_lock);
2421 }
2422 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2423 }
2424
2425 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2426 {
2427 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2428 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2429 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2430 return SC_FLUSH_FILE;
2431 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2432 return SC_FLUSH_DAT;
2433 }
2434 return SC_LSEG_SR;
2435 }
2436
2437 /**
2438 * nilfs_segctor_thread - main loop of the segment constructor thread.
2439 * @arg: pointer to a struct nilfs_sc_info.
2440 *
2441 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2442 * to execute segment constructions.
2443 */
2444 static int nilfs_segctor_thread(void *arg)
2445 {
2446 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2447 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2448 int timeout = 0;
2449
2450 sci->sc_timer.data = (unsigned long)current;
2451 sci->sc_timer.function = nilfs_construction_timeout;
2452
2453 /* start sync. */
2454 sci->sc_task = current;
2455 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2456 printk(KERN_INFO
2457 "segctord starting. Construction interval = %lu seconds, "
2458 "CP frequency < %lu seconds\n",
2459 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2460
2461 spin_lock(&sci->sc_state_lock);
2462 loop:
2463 for (;;) {
2464 int mode;
2465
2466 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2467 goto end_thread;
2468
2469 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2470 mode = SC_LSEG_SR;
2471 else if (!sci->sc_flush_request)
2472 break;
2473 else
2474 mode = nilfs_segctor_flush_mode(sci);
2475
2476 spin_unlock(&sci->sc_state_lock);
2477 nilfs_segctor_thread_construct(sci, mode);
2478 spin_lock(&sci->sc_state_lock);
2479 timeout = 0;
2480 }
2481
2482
2483 if (freezing(current)) {
2484 spin_unlock(&sci->sc_state_lock);
2485 try_to_freeze();
2486 spin_lock(&sci->sc_state_lock);
2487 } else {
2488 DEFINE_WAIT(wait);
2489 int should_sleep = 1;
2490
2491 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2492 TASK_INTERRUPTIBLE);
2493
2494 if (sci->sc_seq_request != sci->sc_seq_done)
2495 should_sleep = 0;
2496 else if (sci->sc_flush_request)
2497 should_sleep = 0;
2498 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2499 should_sleep = time_before(jiffies,
2500 sci->sc_timer.expires);
2501
2502 if (should_sleep) {
2503 spin_unlock(&sci->sc_state_lock);
2504 schedule();
2505 spin_lock(&sci->sc_state_lock);
2506 }
2507 finish_wait(&sci->sc_wait_daemon, &wait);
2508 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2509 time_after_eq(jiffies, sci->sc_timer.expires));
2510
2511 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2512 set_nilfs_discontinued(nilfs);
2513 }
2514 goto loop;
2515
2516 end_thread:
2517 spin_unlock(&sci->sc_state_lock);
2518
2519 /* end sync. */
2520 sci->sc_task = NULL;
2521 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2522 return 0;
2523 }
2524
2525 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2526 {
2527 struct task_struct *t;
2528
2529 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2530 if (IS_ERR(t)) {
2531 int err = PTR_ERR(t);
2532
2533 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2534 err);
2535 return err;
2536 }
2537 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2538 return 0;
2539 }
2540
2541 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2542 __acquires(&sci->sc_state_lock)
2543 __releases(&sci->sc_state_lock)
2544 {
2545 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2546
2547 while (sci->sc_task) {
2548 wake_up(&sci->sc_wait_daemon);
2549 spin_unlock(&sci->sc_state_lock);
2550 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2551 spin_lock(&sci->sc_state_lock);
2552 }
2553 }
2554
2555 /*
2556 * Setup & clean-up functions
2557 */
2558 static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
2559 struct nilfs_root *root)
2560 {
2561 struct the_nilfs *nilfs = sb->s_fs_info;
2562 struct nilfs_sc_info *sci;
2563
2564 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2565 if (!sci)
2566 return NULL;
2567
2568 sci->sc_super = sb;
2569
2570 nilfs_get_root(root);
2571 sci->sc_root = root;
2572
2573 init_waitqueue_head(&sci->sc_wait_request);
2574 init_waitqueue_head(&sci->sc_wait_daemon);
2575 init_waitqueue_head(&sci->sc_wait_task);
2576 spin_lock_init(&sci->sc_state_lock);
2577 INIT_LIST_HEAD(&sci->sc_dirty_files);
2578 INIT_LIST_HEAD(&sci->sc_segbufs);
2579 INIT_LIST_HEAD(&sci->sc_write_logs);
2580 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2581 init_timer(&sci->sc_timer);
2582
2583 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2584 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2585 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2586
2587 if (nilfs->ns_interval)
2588 sci->sc_interval = HZ * nilfs->ns_interval;
2589 if (nilfs->ns_watermark)
2590 sci->sc_watermark = nilfs->ns_watermark;
2591 return sci;
2592 }
2593
2594 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2595 {
2596 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2597
2598 /* The segctord thread was stopped and its timer was removed.
2599 But some tasks remain. */
2600 do {
2601 struct nilfs_transaction_info ti;
2602
2603 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2604 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2605 nilfs_transaction_unlock(sci->sc_super);
2606
2607 } while (ret && retrycount-- > 0);
2608 }
2609
2610 /**
2611 * nilfs_segctor_destroy - destroy the segment constructor.
2612 * @sci: nilfs_sc_info
2613 *
2614 * nilfs_segctor_destroy() kills the segctord thread and frees
2615 * the nilfs_sc_info struct.
2616 * Caller must hold the segment semaphore.
2617 */
2618 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2619 {
2620 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2621 int flag;
2622
2623 up_write(&nilfs->ns_segctor_sem);
2624
2625 spin_lock(&sci->sc_state_lock);
2626 nilfs_segctor_kill_thread(sci);
2627 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2628 || sci->sc_seq_request != sci->sc_seq_done);
2629 spin_unlock(&sci->sc_state_lock);
2630
2631 if (flag || !nilfs_segctor_confirm(sci))
2632 nilfs_segctor_write_out(sci);
2633
2634 if (!list_empty(&sci->sc_dirty_files)) {
2635 nilfs_warning(sci->sc_super, __func__,
2636 "dirty file(s) after the final construction\n");
2637 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
2638 }
2639
2640 WARN_ON(!list_empty(&sci->sc_segbufs));
2641 WARN_ON(!list_empty(&sci->sc_write_logs));
2642
2643 nilfs_put_root(sci->sc_root);
2644
2645 down_write(&nilfs->ns_segctor_sem);
2646
2647 del_timer_sync(&sci->sc_timer);
2648 kfree(sci);
2649 }
2650
2651 /**
2652 * nilfs_attach_log_writer - attach log writer
2653 * @sb: super block instance
2654 * @root: root object of the current filesystem tree
2655 *
2656 * This allocates a log writer object, initializes it, and starts the
2657 * log writer.
2658 *
2659 * Return Value: On success, 0 is returned. On error, one of the following
2660 * negative error code is returned.
2661 *
2662 * %-ENOMEM - Insufficient memory available.
2663 */
2664 int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
2665 {
2666 struct the_nilfs *nilfs = sb->s_fs_info;
2667 int err;
2668
2669 if (nilfs->ns_writer) {
2670 /*
2671 * This happens if the filesystem was remounted
2672 * read/write after nilfs_error degenerated it into a
2673 * read-only mount.
2674 */
2675 nilfs_detach_log_writer(sb);
2676 }
2677
2678 nilfs->ns_writer = nilfs_segctor_new(sb, root);
2679 if (!nilfs->ns_writer)
2680 return -ENOMEM;
2681
2682 err = nilfs_segctor_start_thread(nilfs->ns_writer);
2683 if (err) {
2684 kfree(nilfs->ns_writer);
2685 nilfs->ns_writer = NULL;
2686 }
2687 return err;
2688 }
2689
2690 /**
2691 * nilfs_detach_log_writer - destroy log writer
2692 * @sb: super block instance
2693 *
2694 * This kills log writer daemon, frees the log writer object, and
2695 * destroys list of dirty files.
2696 */
2697 void nilfs_detach_log_writer(struct super_block *sb)
2698 {
2699 struct the_nilfs *nilfs = sb->s_fs_info;
2700 LIST_HEAD(garbage_list);
2701
2702 down_write(&nilfs->ns_segctor_sem);
2703 if (nilfs->ns_writer) {
2704 nilfs_segctor_destroy(nilfs->ns_writer);
2705 nilfs->ns_writer = NULL;
2706 }
2707
2708 /* Force to free the list of dirty files */
2709 spin_lock(&nilfs->ns_inode_lock);
2710 if (!list_empty(&nilfs->ns_dirty_files)) {
2711 list_splice_init(&nilfs->ns_dirty_files, &garbage_list);
2712 nilfs_warning(sb, __func__,
2713 "Hit dirty file after stopped log writer\n");
2714 }
2715 spin_unlock(&nilfs->ns_inode_lock);
2716 up_write(&nilfs->ns_segctor_sem);
2717
2718 nilfs_dispose_list(nilfs, &garbage_list, 1);
2719 }
Linux with added FPC-III support