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nilfs2: segment constructor
[net-next-2.6.git] / fs / nilfs2 / segment.c
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9ff05123
RK		 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 "nilfs.h"
36#include "btnode.h"
37#include "page.h"
38#include "segment.h"
39#include "sufile.h"
40#include "cpfile.h"
41#include "ifile.h"
42#include "seglist.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 */
55enum {
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 */
66enum {
67 NILFS_ST_INIT = 0,
68 NILFS_ST_GC, /* Collecting dirty blocks for GC */
69 NILFS_ST_FILE,
70 NILFS_ST_SKETCH,
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_HISTORY_MASK (NILFS_CF_IFILE_STARTED)
84
85/* Operations depending on the construction mode and file type */
86struct 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 */
104static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
105static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
106static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
107static void nilfs_dispose_list(struct nilfs_sb_info *, struct list_head *,
108 int);
109
110#define nilfs_cnt32_gt(a, b) \
111 (typecheck(__u32, a) && typecheck(__u32, b) && \
112 ((__s32)(b) - (__s32)(a) < 0))
113#define nilfs_cnt32_ge(a, b) \
114 (typecheck(__u32, a) && typecheck(__u32, b) && \
115 ((__s32)(a) - (__s32)(b) >= 0))
116#define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a)
117#define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a)
118
119/*
120 * Transaction
121 */
122static struct kmem_cache *nilfs_transaction_cachep;
123
124/**
125 * nilfs_init_transaction_cache - create a cache for nilfs_transaction_info
126 *
127 * nilfs_init_transaction_cache() creates a slab cache for the struct
128 * nilfs_transaction_info.
129 *
130 * Return Value: On success, it returns 0. On error, one of the following
131 * negative error code is returned.
132 *
133 * %-ENOMEM - Insufficient memory available.
134 */
135int nilfs_init_transaction_cache(void)
136{
137 nilfs_transaction_cachep =
138 kmem_cache_create("nilfs2_transaction_cache",
139 sizeof(struct nilfs_transaction_info),
140 0, SLAB_RECLAIM_ACCOUNT, NULL);
141 return (nilfs_transaction_cachep == NULL) ? -ENOMEM : 0;
142}
143
144/**
145 * nilfs_detroy_transaction_cache - destroy the cache for transaction info
146 *
147 * nilfs_destroy_transaction_cache() frees the slab cache for the struct
148 * nilfs_transaction_info.
149 */
150void nilfs_destroy_transaction_cache(void)
151{
152 kmem_cache_destroy(nilfs_transaction_cachep);
153}
154
155static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
156{
157 struct nilfs_transaction_info *cur_ti = current->journal_info;
158 void *save = NULL;
159
160 if (cur_ti) {
161 if (cur_ti->ti_magic == NILFS_TI_MAGIC)
162 return ++cur_ti->ti_count;
163 else {
164 /*
165 * If journal_info field is occupied by other FS,
166 * we save it and restore on nilfs_transaction_end().
167 * But this should never happen.
168 */
169 printk(KERN_WARNING
170 "NILFS warning: journal info from a different "
171 "FS\n");
172 save = current->journal_info;
173 }
174 }
175 if (!ti) {
176 ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
177 if (!ti)
178 return -ENOMEM;
179 ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
180 } else {
181 ti->ti_flags = 0;
182 }
183 ti->ti_count = 0;
184 ti->ti_save = save;
185 ti->ti_magic = NILFS_TI_MAGIC;
186 current->journal_info = ti;
187 return 0;
188}
189
190/**
191 * nilfs_transaction_begin - start indivisible file operations.
192 * @sb: super block
193 * @ti: nilfs_transaction_info
194 * @vacancy_check: flags for vacancy rate checks
195 *
196 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
197 * the segment semaphore, to make a segment construction and write tasks
198 * exclusive. The function is used with nilfs_transaction_end() in pairs.
199 * The region enclosed by these two functions can be nested. To avoid a
200 * deadlock, the semaphore is only acquired or released in the outermost call.
201 *
202 * This function allocates a nilfs_transaction_info struct to keep context
203 * information on it. It is initialized and hooked onto the current task in
204 * the outermost call. If a pre-allocated struct is given to @ti, it is used
205 * instead; othewise a new struct is assigned from a slab.
206 *
207 * When @vacancy_check flag is set, this function will check the amount of
208 * free space, and will wait for the GC to reclaim disk space if low capacity.
209 *
210 * Return Value: On success, 0 is returned. On error, one of the following
211 * negative error code is returned.
212 *
213 * %-ENOMEM - Insufficient memory available.
214 *
215 * %-ERESTARTSYS - Interrupted
216 *
217 * %-ENOSPC - No space left on device
218 */
219int nilfs_transaction_begin(struct super_block *sb,
220 struct nilfs_transaction_info *ti,
221 int vacancy_check)
222{
223 struct nilfs_sb_info *sbi;
224 struct the_nilfs *nilfs;
225 int ret = nilfs_prepare_segment_lock(ti);
226
227 if (unlikely(ret < 0))
228 return ret;
229 if (ret > 0)
230 return 0;
231
232 sbi = NILFS_SB(sb);
233 nilfs = sbi->s_nilfs;
234 down_read(&nilfs->ns_segctor_sem);
235 if (vacancy_check && nilfs_near_disk_full(nilfs)) {
236 up_read(&nilfs->ns_segctor_sem);
237 ret = -ENOSPC;
238 goto failed;
239 }
240 return 0;
241
242 failed:
243 ti = current->journal_info;
244 current->journal_info = ti->ti_save;
245 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
246 kmem_cache_free(nilfs_transaction_cachep, ti);
247 return ret;
248}
249
250/**
251 * nilfs_transaction_end - end indivisible file operations.
252 * @sb: super block
253 * @commit: commit flag (0 for no change)
254 *
255 * nilfs_transaction_end() releases the read semaphore which is
256 * acquired by nilfs_transaction_begin(). Its releasing is only done
257 * in outermost call of this function. If the nilfs_transaction_info
258 * was allocated dynamically, it is given back to a slab cache.
259 */
260int nilfs_transaction_end(struct super_block *sb, int commit)
261{
262 struct nilfs_transaction_info *ti = current->journal_info;
263 struct nilfs_sb_info *sbi;
264 struct nilfs_sc_info *sci;
265 int err = 0;
266
267 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
268
269 if (commit)
270 ti->ti_flags |= NILFS_TI_COMMIT;
271 if (ti->ti_count > 0) {
272 ti->ti_count--;
273 return 0;
274 }
275 sbi = NILFS_SB(sb);
276 sci = NILFS_SC(sbi);
277 if (sci != NULL) {
278 if (ti->ti_flags & NILFS_TI_COMMIT)
279 nilfs_segctor_start_timer(sci);
280 if (atomic_read(&sbi->s_nilfs->ns_ndirtyblks) >
281 sci->sc_watermark)
282 nilfs_segctor_do_flush(sci, 0);
283 }
284 up_read(&sbi->s_nilfs->ns_segctor_sem);
285 current->journal_info = ti->ti_save;
286
287 if (ti->ti_flags & NILFS_TI_SYNC)
288 err = nilfs_construct_segment(sb);
289 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
290 kmem_cache_free(nilfs_transaction_cachep, ti);
291 return err;
292}
293
294void nilfs_relax_pressure_in_lock(struct super_block *sb)
295{
296 struct nilfs_sb_info *sbi = NILFS_SB(sb);
297 struct nilfs_sc_info *sci = NILFS_SC(sbi);
298 struct the_nilfs *nilfs = sbi->s_nilfs;
299
300 if (!sci || !sci->sc_flush_request)
301 return;
302
303 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
304 up_read(&nilfs->ns_segctor_sem);
305
306 down_write(&nilfs->ns_segctor_sem);
307 if (sci->sc_flush_request &&
308 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
309 struct nilfs_transaction_info *ti = current->journal_info;
310
311 ti->ti_flags |= NILFS_TI_WRITER;
312 nilfs_segctor_do_immediate_flush(sci);
313 ti->ti_flags &= ~NILFS_TI_WRITER;
314 }
315 downgrade_write(&nilfs->ns_segctor_sem);
316}
317
318static void nilfs_transaction_lock(struct nilfs_sb_info *sbi,
319 struct nilfs_transaction_info *ti,
320 int gcflag)
321{
322 struct nilfs_transaction_info *cur_ti = current->journal_info;
323
324 BUG_ON(cur_ti);
325 BUG_ON(!ti);
326 ti->ti_flags = NILFS_TI_WRITER;
327 ti->ti_count = 0;
328 ti->ti_save = cur_ti;
329 ti->ti_magic = NILFS_TI_MAGIC;
330 INIT_LIST_HEAD(&ti->ti_garbage);
331 current->journal_info = ti;
332
333 for (;;) {
334 down_write(&sbi->s_nilfs->ns_segctor_sem);
335 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &NILFS_SC(sbi)->sc_flags))
336 break;
337
338 nilfs_segctor_do_immediate_flush(NILFS_SC(sbi));
339
340 up_write(&sbi->s_nilfs->ns_segctor_sem);
341 yield();
342 }
343 if (gcflag)
344 ti->ti_flags |= NILFS_TI_GC;
345}
346
347static void nilfs_transaction_unlock(struct nilfs_sb_info *sbi)
348{
349 struct nilfs_transaction_info *ti = current->journal_info;
350
351 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
352 BUG_ON(ti->ti_count > 0);
353
354 up_write(&sbi->s_nilfs->ns_segctor_sem);
355 current->journal_info = ti->ti_save;
356 if (!list_empty(&ti->ti_garbage))
357 nilfs_dispose_list(sbi, &ti->ti_garbage, 0);
358}
359
360static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
361 struct nilfs_segsum_pointer *ssp,
362 unsigned bytes)
363{
364 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
365 unsigned blocksize = sci->sc_super->s_blocksize;
366 void *p;
367
368 if (unlikely(ssp->offset + bytes > blocksize)) {
369 ssp->offset = 0;
370 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
371 &segbuf->sb_segsum_buffers));
372 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
373 }
374 p = ssp->bh->b_data + ssp->offset;
375 ssp->offset += bytes;
376 return p;
377}
378
379/**
380 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
381 * @sci: nilfs_sc_info
382 */
383static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
384{
385 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
386 struct buffer_head *sumbh;
387 unsigned sumbytes;
388 unsigned flags = 0;
389 int err;
390
391 if (nilfs_doing_gc())
392 flags = NILFS_SS_GC;
393 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime);
394 if (unlikely(err))
395 return err;
396
397 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
398 sumbytes = segbuf->sb_sum.sumbytes;
399 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
400 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
401 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
402 return 0;
403}
404
405static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
406{
407 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
408 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
409 return -E2BIG; /* The current segment is filled up
410 (internal code) */
411 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
412 return nilfs_segctor_reset_segment_buffer(sci);
413}
414
415static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
416{
417 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
418 int err;
419
420 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
421 err = nilfs_segctor_feed_segment(sci);
422 if (err)
423 return err;
424 segbuf = sci->sc_curseg;
425 }
426 err = nilfs_segbuf_extend_payload(segbuf, &sci->sc_super_root);
427 if (likely(!err))
428 segbuf->sb_sum.flags |= NILFS_SS_SR;
429 return err;
430}
431
432/*
433 * Functions for making segment summary and payloads
434 */
435static int nilfs_segctor_segsum_block_required(
436 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
437 unsigned binfo_size)
438{
439 unsigned blocksize = sci->sc_super->s_blocksize;
440 /* Size of finfo and binfo is enough small against blocksize */
441
442 return ssp->offset + binfo_size +
443 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
444 blocksize;
445}
446
447static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
448 struct inode *inode)
449{
450 sci->sc_curseg->sb_sum.nfinfo++;
451 sci->sc_binfo_ptr = sci->sc_finfo_ptr;
452 nilfs_segctor_map_segsum_entry(
453 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
454 /* skip finfo */
455}
456
457static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
458 struct inode *inode)
459{
460 struct nilfs_finfo *finfo;
461 struct nilfs_inode_info *ii;
462 struct nilfs_segment_buffer *segbuf;
463
464 if (sci->sc_blk_cnt == 0)
465 return;
466
467 ii = NILFS_I(inode);
468 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
469 sizeof(*finfo));
470 finfo->fi_ino = cpu_to_le64(inode->i_ino);
471 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
472 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
473 finfo->fi_cno = cpu_to_le64(ii->i_cno);
474
475 segbuf = sci->sc_curseg;
476 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
477 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
478 sci->sc_finfo_ptr = sci->sc_binfo_ptr;
479 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
480}
481
482static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
483 struct buffer_head *bh,
484 struct inode *inode,
485 unsigned binfo_size)
486{
487 struct nilfs_segment_buffer *segbuf;
488 int required, err = 0;
489
490 retry:
491 segbuf = sci->sc_curseg;
492 required = nilfs_segctor_segsum_block_required(
493 sci, &sci->sc_binfo_ptr, binfo_size);
494 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
495 nilfs_segctor_end_finfo(sci, inode);
496 err = nilfs_segctor_feed_segment(sci);
497 if (err)
498 return err;
499 goto retry;
500 }
501 if (unlikely(required)) {
502 err = nilfs_segbuf_extend_segsum(segbuf);
503 if (unlikely(err))
504 goto failed;
505 }
506 if (sci->sc_blk_cnt == 0)
507 nilfs_segctor_begin_finfo(sci, inode);
508
509 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
510 /* Substitution to vblocknr is delayed until update_blocknr() */
511 nilfs_segbuf_add_file_buffer(segbuf, bh);
512 sci->sc_blk_cnt++;
513 failed:
514 return err;
515}
516
517static int nilfs_handle_bmap_error(int err, const char *fname,
518 struct inode *inode, struct super_block *sb)
519{
520 if (err == -EINVAL) {
521 nilfs_error(sb, fname, "broken bmap (inode=%lu)\n",
522 inode->i_ino);
523 err = -EIO;
524 }
525 return err;
526}
527
528/*
529 * Callback functions that enumerate, mark, and collect dirty blocks
530 */
531static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
532 struct buffer_head *bh, struct inode *inode)
533{
534 int err;
535
536 /* BUG_ON(!buffer_dirty(bh)); */
537 /* excluded by scan_dirty_data_buffers() */
538 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
539 if (unlikely(err < 0))
540 return nilfs_handle_bmap_error(err, __func__, inode,
541 sci->sc_super);
542
543 err = nilfs_segctor_add_file_block(sci, bh, inode,
544 sizeof(struct nilfs_binfo_v));
545 if (!err)
546 sci->sc_datablk_cnt++;
547 return err;
548}
549
550static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
551 struct buffer_head *bh,
552 struct inode *inode)
553{
554 int err;
555
556 /* BUG_ON(!buffer_dirty(bh)); */
557 /* excluded by scan_dirty_node_buffers() */
558 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
559 if (unlikely(err < 0))
560 return nilfs_handle_bmap_error(err, __func__, inode,
561 sci->sc_super);
562 return 0;
563}
564
565static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
566 struct buffer_head *bh,
567 struct inode *inode)
568{
569 BUG_ON(!buffer_dirty(bh));
570 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
571}
572
573static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
574 struct nilfs_segsum_pointer *ssp,
575 union nilfs_binfo *binfo)
576{
577 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
578 sci, ssp, sizeof(*binfo_v));
579 *binfo_v = binfo->bi_v;
580}
581
582static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
583 struct nilfs_segsum_pointer *ssp,
584 union nilfs_binfo *binfo)
585{
586 __le64 *vblocknr = nilfs_segctor_map_segsum_entry(
587 sci, ssp, sizeof(*vblocknr));
588 *vblocknr = binfo->bi_v.bi_vblocknr;
589}
590
591struct nilfs_sc_operations nilfs_sc_file_ops = {
592 .collect_data = nilfs_collect_file_data,
593 .collect_node = nilfs_collect_file_node,
594 .collect_bmap = nilfs_collect_file_bmap,
595 .write_data_binfo = nilfs_write_file_data_binfo,
596 .write_node_binfo = nilfs_write_file_node_binfo,
597};
598
599static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
600 struct buffer_head *bh, struct inode *inode)
601{
602 int err;
603
604 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
605 if (unlikely(err < 0))
606 return nilfs_handle_bmap_error(err, __func__, inode,
607 sci->sc_super);
608
609 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
610 if (!err)
611 sci->sc_datablk_cnt++;
612 return err;
613}
614
615static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
616 struct buffer_head *bh, struct inode *inode)
617{
618 BUG_ON(!buffer_dirty(bh));
619 return nilfs_segctor_add_file_block(sci, bh, inode,
620 sizeof(struct nilfs_binfo_dat));
621}
622
623static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
624 struct nilfs_segsum_pointer *ssp,
625 union nilfs_binfo *binfo)
626{
627 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
628 sizeof(*blkoff));
629 *blkoff = binfo->bi_dat.bi_blkoff;
630}
631
632static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
633 struct nilfs_segsum_pointer *ssp,
634 union nilfs_binfo *binfo)
635{
636 struct nilfs_binfo_dat *binfo_dat =
637 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
638 *binfo_dat = binfo->bi_dat;
639}
640
641struct nilfs_sc_operations nilfs_sc_dat_ops = {
642 .collect_data = nilfs_collect_dat_data,
643 .collect_node = nilfs_collect_file_node,
644 .collect_bmap = nilfs_collect_dat_bmap,
645 .write_data_binfo = nilfs_write_dat_data_binfo,
646 .write_node_binfo = nilfs_write_dat_node_binfo,
647};
648
649struct nilfs_sc_operations nilfs_sc_dsync_ops = {
650 .collect_data = nilfs_collect_file_data,
651 .collect_node = NULL,
652 .collect_bmap = NULL,
653 .write_data_binfo = nilfs_write_file_data_binfo,
654 .write_node_binfo = NULL,
655};
656
657static int nilfs_lookup_dirty_data_buffers(struct inode *inode,
658 struct list_head *listp,
659 struct nilfs_sc_info *sci)
660{
661 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
662 struct address_space *mapping = inode->i_mapping;
663 struct pagevec pvec;
664 unsigned i, ndirties = 0, nlimit;
665 pgoff_t index = 0;
666 int err = 0;
667
668 nlimit = sci->sc_segbuf_nblocks -
669 (sci->sc_nblk_this_inc + segbuf->sb_sum.nblocks);
670 pagevec_init(&pvec, 0);
671 repeat:
672 if (!pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
673 PAGEVEC_SIZE))
674 return 0;
675
676 for (i = 0; i < pagevec_count(&pvec); i++) {
677 struct buffer_head *bh, *head;
678 struct page *page = pvec.pages[i];
679
680 if (mapping->host) {
681 lock_page(page);
682 if (!page_has_buffers(page))
683 create_empty_buffers(page,
684 1 << inode->i_blkbits, 0);
685 unlock_page(page);
686 }
687
688 bh = head = page_buffers(page);
689 do {
690 if (buffer_dirty(bh)) {
691 if (ndirties > nlimit) {
692 err = -E2BIG;
693 break;
694 }
695 get_bh(bh);
696 list_add_tail(&bh->b_assoc_buffers, listp);
697 ndirties++;
698 }
699 bh = bh->b_this_page;
700 } while (bh != head);
701 }
702 pagevec_release(&pvec);
703 cond_resched();
704
705 if (!err)
706 goto repeat;
707 return err;
708}
709
710static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
711 struct list_head *listp)
712{
713 struct nilfs_inode_info *ii = NILFS_I(inode);
714 struct address_space *mapping = &ii->i_btnode_cache;
715 struct pagevec pvec;
716 struct buffer_head *bh, *head;
717 unsigned int i;
718 pgoff_t index = 0;
719
720 pagevec_init(&pvec, 0);
721
722 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
723 PAGEVEC_SIZE)) {
724 for (i = 0; i < pagevec_count(&pvec); i++) {
725 bh = head = page_buffers(pvec.pages[i]);
726 do {
727 if (buffer_dirty(bh)) {
728 get_bh(bh);
729 list_add_tail(&bh->b_assoc_buffers,
730 listp);
731 }
732 bh = bh->b_this_page;
733 } while (bh != head);
734 }
735 pagevec_release(&pvec);
736 cond_resched();
737 }
738}
739
740static void nilfs_dispose_list(struct nilfs_sb_info *sbi,
741 struct list_head *head, int force)
742{
743 struct nilfs_inode_info *ii, *n;
744 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
745 unsigned nv = 0;
746
747 while (!list_empty(head)) {
748 spin_lock(&sbi->s_inode_lock);
749 list_for_each_entry_safe(ii, n, head, i_dirty) {
750 list_del_init(&ii->i_dirty);
751 if (force) {
752 if (unlikely(ii->i_bh)) {
753 brelse(ii->i_bh);
754 ii->i_bh = NULL;
755 }
756 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
757 set_bit(NILFS_I_QUEUED, &ii->i_state);
758 list_add_tail(&ii->i_dirty,
759 &sbi->s_dirty_files);
760 continue;
761 }
762 ivec[nv++] = ii;
763 if (nv == SC_N_INODEVEC)
764 break;
765 }
766 spin_unlock(&sbi->s_inode_lock);
767
768 for (pii = ivec; nv > 0; pii++, nv--)
769 iput(&(*pii)->vfs_inode);
770 }
771}
772
773static int nilfs_test_metadata_dirty(struct nilfs_sb_info *sbi)
774{
775 struct the_nilfs *nilfs = sbi->s_nilfs;
776 int ret = 0;
777
778 if (nilfs_mdt_fetch_dirty(sbi->s_ifile))
779 ret++;
780 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
781 ret++;
782 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
783 ret++;
784 if (ret || nilfs_doing_gc())
785 if (nilfs_mdt_fetch_dirty(nilfs_dat_inode(nilfs)))
786 ret++;
787 return ret;
788}
789
790static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
791{
792 return list_empty(&sci->sc_dirty_files) &&
793 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
794 list_empty(&sci->sc_cleaning_segments) &&
795 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
796}
797
798static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
799{
800 struct nilfs_sb_info *sbi = sci->sc_sbi;
801 int ret = 0;
802
803 if (nilfs_test_metadata_dirty(sbi))
804 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
805
806 spin_lock(&sbi->s_inode_lock);
807 if (list_empty(&sbi->s_dirty_files) && nilfs_segctor_clean(sci))
808 ret++;
809
810 spin_unlock(&sbi->s_inode_lock);
811 return ret;
812}
813
814static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
815{
816 struct nilfs_sb_info *sbi = sci->sc_sbi;
817 struct the_nilfs *nilfs = sbi->s_nilfs;
818
819 nilfs_mdt_clear_dirty(sbi->s_ifile);
820 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
821 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
822 nilfs_mdt_clear_dirty(nilfs_dat_inode(nilfs));
823}
824
825static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
826{
827 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
828 struct buffer_head *bh_cp;
829 struct nilfs_checkpoint *raw_cp;
830 int err;
831
832 /* XXX: this interface will be changed */
833 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
834 &raw_cp, &bh_cp);
835 if (likely(!err)) {
836 /* The following code is duplicated with cpfile. But, it is
837 needed to collect the checkpoint even if it was not newly
838 created */
839 nilfs_mdt_mark_buffer_dirty(bh_cp);
840 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
841 nilfs_cpfile_put_checkpoint(
842 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
843 } else {
844 BUG_ON(err == -EINVAL || err == -ENOENT);
845 }
846 return err;
847}
848
849static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
850{
851 struct nilfs_sb_info *sbi = sci->sc_sbi;
852 struct the_nilfs *nilfs = sbi->s_nilfs;
853 struct buffer_head *bh_cp;
854 struct nilfs_checkpoint *raw_cp;
855 int err;
856
857 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
858 &raw_cp, &bh_cp);
859 if (unlikely(err)) {
860 BUG_ON(err == -EINVAL || err == -ENOENT);
861 goto failed_ibh;
862 }
863 raw_cp->cp_snapshot_list.ssl_next = 0;
864 raw_cp->cp_snapshot_list.ssl_prev = 0;
865 raw_cp->cp_inodes_count =
866 cpu_to_le64(atomic_read(&sbi->s_inodes_count));
867 raw_cp->cp_blocks_count =
868 cpu_to_le64(atomic_read(&sbi->s_blocks_count));
869 raw_cp->cp_nblk_inc =
870 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
871 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
872 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
873 if (sci->sc_sketch_inode && i_size_read(sci->sc_sketch_inode) > 0)
874 nilfs_checkpoint_set_sketch(raw_cp);
875 nilfs_write_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode, 1);
876 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
877 return 0;
878
879 failed_ibh:
880 return err;
881}
882
883static void nilfs_fill_in_file_bmap(struct inode *ifile,
884 struct nilfs_inode_info *ii)
885
886{
887 struct buffer_head *ibh;
888 struct nilfs_inode *raw_inode;
889
890 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
891 ibh = ii->i_bh;
892 BUG_ON(!ibh);
893 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
894 ibh);
895 nilfs_bmap_write(ii->i_bmap, raw_inode);
896 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
897 }
898}
899
900static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci,
901 struct inode *ifile)
902{
903 struct nilfs_inode_info *ii;
904
905 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
906 nilfs_fill_in_file_bmap(ifile, ii);
907 set_bit(NILFS_I_COLLECTED, &ii->i_state);
908 }
909 if (sci->sc_sketch_inode) {
910 ii = NILFS_I(sci->sc_sketch_inode);
911 if (test_bit(NILFS_I_DIRTY, &ii->i_state))
912 nilfs_fill_in_file_bmap(ifile, ii);
913 }
914}
915
916/*
917 * CRC calculation routines
918 */
919static void nilfs_fill_in_super_root_crc(struct buffer_head *bh_sr, u32 seed)
920{
921 struct nilfs_super_root *raw_sr =
922 (struct nilfs_super_root *)bh_sr->b_data;
923 u32 crc;
924
925 BUG_ON(NILFS_SR_BYTES > bh_sr->b_size);
926 crc = crc32_le(seed,
927 (unsigned char *)raw_sr + sizeof(raw_sr->sr_sum),
928 NILFS_SR_BYTES - sizeof(raw_sr->sr_sum));
929 raw_sr->sr_sum = cpu_to_le32(crc);
930}
931
932static void nilfs_segctor_fill_in_checksums(struct nilfs_sc_info *sci,
933 u32 seed)
934{
935 struct nilfs_segment_buffer *segbuf;
936
937 if (sci->sc_super_root)
938 nilfs_fill_in_super_root_crc(sci->sc_super_root, seed);
939
940 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
941 nilfs_segbuf_fill_in_segsum_crc(segbuf, seed);
942 nilfs_segbuf_fill_in_data_crc(segbuf, seed);
943 }
944}
945
946static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
947 struct the_nilfs *nilfs)
948{
949 struct buffer_head *bh_sr = sci->sc_super_root;
950 struct nilfs_super_root *raw_sr =
951 (struct nilfs_super_root *)bh_sr->b_data;
952 unsigned isz = nilfs->ns_inode_size;
953
954 raw_sr->sr_bytes = cpu_to_le16(NILFS_SR_BYTES);
955 raw_sr->sr_nongc_ctime
956 = cpu_to_le64(nilfs_doing_gc() ?
957 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
958 raw_sr->sr_flags = 0;
959
960 nilfs_mdt_write_inode_direct(
961 nilfs_dat_inode(nilfs), bh_sr, NILFS_SR_DAT_OFFSET(isz));
962 nilfs_mdt_write_inode_direct(
963 nilfs->ns_cpfile, bh_sr, NILFS_SR_CPFILE_OFFSET(isz));
964 nilfs_mdt_write_inode_direct(
965 nilfs->ns_sufile, bh_sr, NILFS_SR_SUFILE_OFFSET(isz));
966}
967
968static void nilfs_redirty_inodes(struct list_head *head)
969{
970 struct nilfs_inode_info *ii;
971
972 list_for_each_entry(ii, head, i_dirty) {
973 if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
974 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
975 }
976}
977
978static void nilfs_drop_collected_inodes(struct list_head *head)
979{
980 struct nilfs_inode_info *ii;
981
982 list_for_each_entry(ii, head, i_dirty) {
983 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
984 continue;
985
986 clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
987 set_bit(NILFS_I_UPDATED, &ii->i_state);
988 }
989}
990
991static void nilfs_segctor_cancel_free_segments(struct nilfs_sc_info *sci,
992 struct inode *sufile)
993
994{
995 struct list_head *head = &sci->sc_cleaning_segments;
996 struct nilfs_segment_entry *ent;
997 int err;
998
999 list_for_each_entry(ent, head, list) {
1000 if (!(ent->flags & NILFS_SLH_FREED))
1001 break;
1002 err = nilfs_sufile_cancel_free(sufile, ent->segnum);
1003 BUG_ON(err);
1004
1005 ent->flags &= ~NILFS_SLH_FREED;
1006 }
1007}
1008
1009static int nilfs_segctor_prepare_free_segments(struct nilfs_sc_info *sci,
1010 struct inode *sufile)
1011{
1012 struct list_head *head = &sci->sc_cleaning_segments;
1013 struct nilfs_segment_entry *ent;
1014 int err;
1015
1016 list_for_each_entry(ent, head, list) {
1017 err = nilfs_sufile_free(sufile, ent->segnum);
1018 if (unlikely(err))
1019 return err;
1020 ent->flags |= NILFS_SLH_FREED;
1021 }
1022 return 0;
1023}
1024
1025static void nilfs_segctor_commit_free_segments(struct nilfs_sc_info *sci)
1026{
1027 nilfs_dispose_segment_list(&sci->sc_cleaning_segments);
1028}
1029
1030static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
1031 struct inode *inode,
1032 struct list_head *listp,
1033 int (*collect)(struct nilfs_sc_info *,
1034 struct buffer_head *,
1035 struct inode *))
1036{
1037 struct buffer_head *bh, *n;
1038 int err = 0;
1039
1040 if (collect) {
1041 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
1042 list_del_init(&bh->b_assoc_buffers);
1043 err = collect(sci, bh, inode);
1044 brelse(bh);
1045 if (unlikely(err))
1046 goto dispose_buffers;
1047 }
1048 return 0;
1049 }
1050
1051 dispose_buffers:
1052 while (!list_empty(listp)) {
1053 bh = list_entry(listp->next, struct buffer_head,
1054 b_assoc_buffers);
1055 list_del_init(&bh->b_assoc_buffers);
1056 brelse(bh);
1057 }
1058 return err;
1059}
1060
1061static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
1062 struct inode *inode,
1063 struct nilfs_sc_operations *sc_ops)
1064{
1065 LIST_HEAD(data_buffers);
1066 LIST_HEAD(node_buffers);
1067 int err, err2;
1068
1069 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1070 err = nilfs_lookup_dirty_data_buffers(inode, &data_buffers,
1071 sci);
1072 if (err) {
1073 err2 = nilfs_segctor_apply_buffers(
1074 sci, inode, &data_buffers,
1075 err == -E2BIG ? sc_ops->collect_data : NULL);
1076 if (err == -E2BIG)
1077 err = err2;
1078 goto break_or_fail;
1079 }
1080 }
1081 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
1082
1083 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1084 err = nilfs_segctor_apply_buffers(
1085 sci, inode, &data_buffers, sc_ops->collect_data);
1086 if (unlikely(err)) {
1087 /* dispose node list */
1088 nilfs_segctor_apply_buffers(
1089 sci, inode, &node_buffers, NULL);
1090 goto break_or_fail;
1091 }
1092 sci->sc_stage.flags |= NILFS_CF_NODE;
1093 }
1094 /* Collect node */
1095 err = nilfs_segctor_apply_buffers(
1096 sci, inode, &node_buffers, sc_ops->collect_node);
1097 if (unlikely(err))
1098 goto break_or_fail;
1099
1100 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1101 err = nilfs_segctor_apply_buffers(
1102 sci, inode, &node_buffers, sc_ops->collect_bmap);
1103 if (unlikely(err))
1104 goto break_or_fail;
1105
1106 nilfs_segctor_end_finfo(sci, inode);
1107 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1108
1109 break_or_fail:
1110 return err;
1111}
1112
1113static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1114 struct inode *inode)
1115{
1116 LIST_HEAD(data_buffers);
1117 int err, err2;
1118
1119 err = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, sci);
1120 err2 = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1121 (!err || err == -E2BIG) ?
1122 nilfs_collect_file_data : NULL);
1123 if (err == -E2BIG)
1124 err = err2;
1125 if (!err)
1126 nilfs_segctor_end_finfo(sci, inode);
1127 return err;
1128}
1129
1130static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1131{
1132 struct nilfs_sb_info *sbi = sci->sc_sbi;
1133 struct the_nilfs *nilfs = sbi->s_nilfs;
1134 struct list_head *head;
1135 struct nilfs_inode_info *ii;
1136 int err = 0;
1137
1138 switch (sci->sc_stage.scnt) {
1139 case NILFS_ST_INIT:
1140 /* Pre-processes */
1141 sci->sc_stage.flags = 0;
1142
1143 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1144 sci->sc_nblk_inc = 0;
1145 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1146 if (mode == SC_LSEG_DSYNC) {
1147 sci->sc_stage.scnt = NILFS_ST_DSYNC;
1148 goto dsync_mode;
1149 }
1150 }
1151
1152 sci->sc_stage.dirty_file_ptr = NULL;
1153 sci->sc_stage.gc_inode_ptr = NULL;
1154 if (mode == SC_FLUSH_DAT) {
1155 sci->sc_stage.scnt = NILFS_ST_DAT;
1156 goto dat_stage;
1157 }
1158 sci->sc_stage.scnt++; /* Fall through */
1159 case NILFS_ST_GC:
1160 if (nilfs_doing_gc()) {
1161 head = &sci->sc_gc_inodes;
1162 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1163 head, i_dirty);
1164 list_for_each_entry_continue(ii, head, i_dirty) {
1165 err = nilfs_segctor_scan_file(
1166 sci, &ii->vfs_inode,
1167 &nilfs_sc_file_ops);
1168 if (unlikely(err)) {
1169 sci->sc_stage.gc_inode_ptr = list_entry(
1170 ii->i_dirty.prev,
1171 struct nilfs_inode_info,
1172 i_dirty);
1173 goto break_or_fail;
1174 }
1175 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1176 }
1177 sci->sc_stage.gc_inode_ptr = NULL;
1178 }
1179 sci->sc_stage.scnt++; /* Fall through */
1180 case NILFS_ST_FILE:
1181 head = &sci->sc_dirty_files;
1182 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1183 i_dirty);
1184 list_for_each_entry_continue(ii, head, i_dirty) {
1185 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1186
1187 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1188 &nilfs_sc_file_ops);
1189 if (unlikely(err)) {
1190 sci->sc_stage.dirty_file_ptr =
1191 list_entry(ii->i_dirty.prev,
1192 struct nilfs_inode_info,
1193 i_dirty);
1194 goto break_or_fail;
1195 }
1196 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1197 /* XXX: required ? */
1198 }
1199 sci->sc_stage.dirty_file_ptr = NULL;
1200 if (mode == SC_FLUSH_FILE) {
1201 sci->sc_stage.scnt = NILFS_ST_DONE;
1202 return 0;
1203 }
1204 sci->sc_stage.scnt++; /* Fall through */
1205 case NILFS_ST_SKETCH:
1206 if (mode == SC_LSEG_SR && sci->sc_sketch_inode) {
1207 ii = NILFS_I(sci->sc_sketch_inode);
1208 if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
1209 sci->sc_sketch_inode->i_ctime.tv_sec
1210 = sci->sc_seg_ctime;
1211 sci->sc_sketch_inode->i_mtime.tv_sec
1212 = sci->sc_seg_ctime;
1213 err = nilfs_mark_inode_dirty(
1214 sci->sc_sketch_inode);
1215 if (unlikely(err))
1216 goto break_or_fail;
1217 }
1218 err = nilfs_segctor_scan_file(sci,
1219 sci->sc_sketch_inode,
1220 &nilfs_sc_file_ops);
1221 if (unlikely(err))
1222 goto break_or_fail;
1223 }
1224 sci->sc_stage.scnt++;
1225 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1226 /* Fall through */
1227 case NILFS_ST_IFILE:
1228 err = nilfs_segctor_scan_file(sci, sbi->s_ifile,
1229 &nilfs_sc_file_ops);
1230 if (unlikely(err))
1231 break;
1232 sci->sc_stage.scnt++;
1233 /* Creating a checkpoint */
1234 err = nilfs_segctor_create_checkpoint(sci);
1235 if (unlikely(err))
1236 break;
1237 /* Fall through */
1238 case NILFS_ST_CPFILE:
1239 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1240 &nilfs_sc_file_ops);
1241 if (unlikely(err))
1242 break;
1243 sci->sc_stage.scnt++; /* Fall through */
1244 case NILFS_ST_SUFILE:
1245 err = nilfs_segctor_prepare_free_segments(sci,
1246 nilfs->ns_sufile);
1247 if (unlikely(err))
1248 break;
1249 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1250 &nilfs_sc_file_ops);
1251 if (unlikely(err))
1252 break;
1253 sci->sc_stage.scnt++; /* Fall through */
1254 case NILFS_ST_DAT:
1255 dat_stage:
1256 err = nilfs_segctor_scan_file(sci, nilfs_dat_inode(nilfs),
1257 &nilfs_sc_dat_ops);
1258 if (unlikely(err))
1259 break;
1260 if (mode == SC_FLUSH_DAT) {
1261 sci->sc_stage.scnt = NILFS_ST_DONE;
1262 return 0;
1263 }
1264 sci->sc_stage.scnt++; /* Fall through */
1265 case NILFS_ST_SR:
1266 if (mode == SC_LSEG_SR) {
1267 /* Appending a super root */
1268 err = nilfs_segctor_add_super_root(sci);
1269 if (unlikely(err))
1270 break;
1271 }
1272 /* End of a logical segment */
1273 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1274 sci->sc_stage.scnt = NILFS_ST_DONE;
1275 return 0;
1276 case NILFS_ST_DSYNC:
1277 dsync_mode:
1278 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1279 ii = sci->sc_stage.dirty_file_ptr;
1280 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1281 break;
1282
1283 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1284 if (unlikely(err))
1285 break;
1286 sci->sc_stage.dirty_file_ptr = NULL;
1287 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1288 sci->sc_stage.scnt = NILFS_ST_DONE;
1289 return 0;
1290 case NILFS_ST_DONE:
1291 return 0;
1292 default:
1293 BUG();
1294 }
1295
1296 break_or_fail:
1297 return err;
1298}
1299
1300static int nilfs_segctor_terminate_segment(struct nilfs_sc_info *sci,
1301 struct nilfs_segment_buffer *segbuf,
1302 struct inode *sufile)
1303{
1304 struct nilfs_segment_entry *ent = segbuf->sb_segent;
1305 int err;
1306
1307 err = nilfs_open_segment_entry(ent, sufile);
1308 if (unlikely(err))
1309 return err;
1310 nilfs_mdt_mark_buffer_dirty(ent->bh_su);
1311 nilfs_mdt_mark_dirty(sufile);
1312 nilfs_close_segment_entry(ent, sufile);
1313
1314 list_add_tail(&ent->list, &sci->sc_active_segments);
1315 segbuf->sb_segent = NULL;
1316 return 0;
1317}
1318
1319static int nilfs_touch_segusage(struct inode *sufile, __u64 segnum)
1320{
1321 struct buffer_head *bh_su;
1322 struct nilfs_segment_usage *raw_su;
1323 int err;
1324
1325 err = nilfs_sufile_get_segment_usage(sufile, segnum, &raw_su, &bh_su);
1326 if (unlikely(err))
1327 return err;
1328 nilfs_mdt_mark_buffer_dirty(bh_su);
1329 nilfs_mdt_mark_dirty(sufile);
1330 nilfs_sufile_put_segment_usage(sufile, segnum, bh_su);
1331 return 0;
1332}
1333
1334static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1335 struct the_nilfs *nilfs)
1336{
1337 struct nilfs_segment_buffer *segbuf, *n;
1338 struct inode *sufile = nilfs->ns_sufile;
1339 __u64 nextnum;
1340 int err;
1341
1342 if (list_empty(&sci->sc_segbufs)) {
1343 segbuf = nilfs_segbuf_new(sci->sc_super);
1344 if (unlikely(!segbuf))
1345 return -ENOMEM;
1346 list_add(&segbuf->sb_list, &sci->sc_segbufs);
1347 } else
1348 segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1349
1350 err = nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1351 nilfs->ns_pseg_offset, nilfs);
1352 if (unlikely(err))
1353 return err;
1354
1355 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1356 err = nilfs_segctor_terminate_segment(sci, segbuf, sufile);
1357 if (unlikely(err))
1358 return err;
1359
1360 nilfs_shift_to_next_segment(nilfs);
1361 err = nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1362 }
1363 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1364
1365 err = nilfs_touch_segusage(sufile, segbuf->sb_segnum);
1366 if (unlikely(err))
1367 return err;
1368
1369 if (nilfs->ns_segnum == nilfs->ns_nextnum) {
1370 /* Start from the head of a new full segment */
1371 err = nilfs_sufile_alloc(sufile, &nextnum);
1372 if (unlikely(err))
1373 return err;
1374 } else
1375 nextnum = nilfs->ns_nextnum;
1376
1377 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1378 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1379
1380 /* truncating segment buffers */
1381 list_for_each_entry_safe_continue(segbuf, n, &sci->sc_segbufs,
1382 sb_list) {
1383 list_del_init(&segbuf->sb_list);
1384 nilfs_segbuf_free(segbuf);
1385 }
1386 return err;
1387}
1388
1389static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1390 struct the_nilfs *nilfs, int nadd)
1391{
1392 struct nilfs_segment_buffer *segbuf, *prev, *n;
1393 struct inode *sufile = nilfs->ns_sufile;
1394 __u64 nextnextnum;
1395 LIST_HEAD(list);
1396 int err, ret, i;
1397
1398 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1399 /*
1400 * Since the segment specified with nextnum might be allocated during
1401 * the previous construction, the buffer including its segusage may
1402 * not be dirty. The following call ensures that the buffer is dirty
1403 * and will pin the buffer on memory until the sufile is written.
1404 */
1405 err = nilfs_touch_segusage(sufile, prev->sb_nextnum);
1406 if (unlikely(err))
1407 return err;
1408
1409 for (i = 0; i < nadd; i++) {
1410 /* extend segment info */
1411 err = -ENOMEM;
1412 segbuf = nilfs_segbuf_new(sci->sc_super);
1413 if (unlikely(!segbuf))
1414 goto failed;
1415
1416 /* map this buffer to region of segment on-disk */
1417 err = nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1418 if (unlikely(err))
1419 goto failed_segbuf;
1420
1421 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1422
1423 /* allocate the next next full segment */
1424 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1425 if (unlikely(err))
1426 goto failed_segbuf;
1427
1428 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1429 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1430
1431 list_add_tail(&segbuf->sb_list, &list);
1432 prev = segbuf;
1433 }
1434 list_splice(&list, sci->sc_segbufs.prev);
1435 return 0;
1436
1437 failed_segbuf:
1438 nilfs_segbuf_free(segbuf);
1439 failed:
1440 list_for_each_entry_safe(segbuf, n, &list, sb_list) {
1441 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1442 BUG_ON(ret);
1443 list_del_init(&segbuf->sb_list);
1444 nilfs_segbuf_free(segbuf);
1445 }
1446 return err;
1447}
1448
1449static void nilfs_segctor_free_incomplete_segments(struct nilfs_sc_info *sci,
1450 struct the_nilfs *nilfs)
1451{
1452 struct nilfs_segment_buffer *segbuf;
1453 int ret, done = 0;
1454
1455 segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1456 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1457 ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
1458 BUG_ON(ret);
1459 }
1460 if (segbuf->sb_io_error) {
1461 /* Case 1: The first segment failed */
1462 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1463 /* Case 1a: Partial segment appended into an existing
1464 segment */
1465 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1466 segbuf->sb_fseg_end);
1467 else /* Case 1b: New full segment */
1468 set_nilfs_discontinued(nilfs);
1469 done++;
1470 }
1471
1472 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1473 ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
1474 BUG_ON(ret);
1475 if (!done && segbuf->sb_io_error) {
1476 if (segbuf->sb_segnum != nilfs->ns_nextnum)
1477 /* Case 2: extended segment (!= next) failed */
1478 nilfs_sufile_set_error(nilfs->ns_sufile,
1479 segbuf->sb_segnum);
1480 done++;
1481 }
1482 }
1483}
1484
1485static void nilfs_segctor_clear_segment_buffers(struct nilfs_sc_info *sci)
1486{
1487 struct nilfs_segment_buffer *segbuf;
1488
1489 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list)
1490 nilfs_segbuf_clear(segbuf);
1491 sci->sc_super_root = NULL;
1492}
1493
1494static void nilfs_segctor_destroy_segment_buffers(struct nilfs_sc_info *sci)
1495{
1496 struct nilfs_segment_buffer *segbuf;
1497
1498 while (!list_empty(&sci->sc_segbufs)) {
1499 segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1500 list_del_init(&segbuf->sb_list);
1501 nilfs_segbuf_free(segbuf);
1502 }
1503 /* sci->sc_curseg = NULL; */
1504}
1505
1506static void nilfs_segctor_end_construction(struct nilfs_sc_info *sci,
1507 struct the_nilfs *nilfs, int err)
1508{
1509 if (unlikely(err)) {
1510 nilfs_segctor_free_incomplete_segments(sci, nilfs);
1511 nilfs_segctor_cancel_free_segments(sci, nilfs->ns_sufile);
1512 }
1513 nilfs_segctor_clear_segment_buffers(sci);
1514}
1515
1516static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1517 struct inode *sufile)
1518{
1519 struct nilfs_segment_buffer *segbuf;
1520 struct buffer_head *bh_su;
1521 struct nilfs_segment_usage *raw_su;
1522 unsigned long live_blocks;
1523 int ret;
1524
1525 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1526 ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
1527 &raw_su, &bh_su);
1528 BUG_ON(ret); /* always succeed because bh_su is dirty */
1529 live_blocks = segbuf->sb_sum.nblocks +
1530 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1531 raw_su->su_lastmod = cpu_to_le64(sci->sc_seg_ctime);
1532 raw_su->su_nblocks = cpu_to_le32(live_blocks);
1533 nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum,
1534 bh_su);
1535 }
1536}
1537
1538static void nilfs_segctor_cancel_segusage(struct nilfs_sc_info *sci,
1539 struct inode *sufile)
1540{
1541 struct nilfs_segment_buffer *segbuf;
1542 struct buffer_head *bh_su;
1543 struct nilfs_segment_usage *raw_su;
1544 int ret;
1545
1546 segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1547 ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
1548 &raw_su, &bh_su);
1549 BUG_ON(ret); /* always succeed because bh_su is dirty */
1550 raw_su->su_nblocks = cpu_to_le32(segbuf->sb_pseg_start -
1551 segbuf->sb_fseg_start);
1552 nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum, bh_su);
1553
1554 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1555 ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
1556 &raw_su, &bh_su);
1557 BUG_ON(ret); /* always succeed */
1558 raw_su->su_nblocks = 0;
1559 nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum,
1560 bh_su);
1561 }
1562}
1563
1564static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1565 struct nilfs_segment_buffer *last,
1566 struct inode *sufile)
1567{
1568 struct nilfs_segment_buffer *segbuf = last, *n;
1569 int ret;
1570
1571 list_for_each_entry_safe_continue(segbuf, n, &sci->sc_segbufs,
1572 sb_list) {
1573 list_del_init(&segbuf->sb_list);
1574 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1575 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1576 BUG_ON(ret);
1577 nilfs_segbuf_free(segbuf);
1578 }
1579}
1580
1581
1582static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1583 struct the_nilfs *nilfs, int mode)
1584{
1585 struct nilfs_cstage prev_stage = sci->sc_stage;
1586 int err, nadd = 1;
1587
1588 /* Collection retry loop */
1589 for (;;) {
1590 sci->sc_super_root = NULL;
1591 sci->sc_nblk_this_inc = 0;
1592 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1593
1594 err = nilfs_segctor_reset_segment_buffer(sci);
1595 if (unlikely(err))
1596 goto failed;
1597
1598 err = nilfs_segctor_collect_blocks(sci, mode);
1599 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1600 if (!err)
1601 break;
1602
1603 if (unlikely(err != -E2BIG))
1604 goto failed;
1605
1606 /* The current segment is filled up */
1607 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
1608 break;
1609
1610 nilfs_segctor_cancel_free_segments(sci, nilfs->ns_sufile);
1611 nilfs_segctor_clear_segment_buffers(sci);
1612
1613 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1614 if (unlikely(err))
1615 return err;
1616
1617 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1618 sci->sc_stage = prev_stage;
1619 }
1620 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1621 return 0;
1622
1623 failed:
1624 return err;
1625}
1626
1627static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1628 struct buffer_head *new_bh)
1629{
1630 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1631
1632 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1633 /* The caller must release old_bh */
1634}
1635
1636static int
1637nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1638 struct nilfs_segment_buffer *segbuf,
1639 int mode)
1640{
1641 struct inode *inode = NULL;
1642 sector_t blocknr;
1643 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1644 unsigned long nblocks = 0, ndatablk = 0;
1645 struct nilfs_sc_operations *sc_op = NULL;
1646 struct nilfs_segsum_pointer ssp;
1647 struct nilfs_finfo *finfo = NULL;
1648 union nilfs_binfo binfo;
1649 struct buffer_head *bh, *bh_org;
1650 ino_t ino = 0;
1651 int err = 0;
1652
1653 if (!nfinfo)
1654 goto out;
1655
1656 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1657 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1658 ssp.offset = sizeof(struct nilfs_segment_summary);
1659
1660 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1661 if (bh == sci->sc_super_root)
1662 break;
1663 if (!finfo) {
1664 finfo = nilfs_segctor_map_segsum_entry(
1665 sci, &ssp, sizeof(*finfo));
1666 ino = le64_to_cpu(finfo->fi_ino);
1667 nblocks = le32_to_cpu(finfo->fi_nblocks);
1668 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1669
1670 if (buffer_nilfs_node(bh))
1671 inode = NILFS_BTNC_I(bh->b_page->mapping);
1672 else
1673 inode = NILFS_AS_I(bh->b_page->mapping);
1674
1675 if (mode == SC_LSEG_DSYNC)
1676 sc_op = &nilfs_sc_dsync_ops;
1677 else if (ino == NILFS_DAT_INO)
1678 sc_op = &nilfs_sc_dat_ops;
1679 else /* file blocks */
1680 sc_op = &nilfs_sc_file_ops;
1681 }
1682 bh_org = bh;
1683 get_bh(bh_org);
1684 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1685 &binfo);
1686 if (bh != bh_org)
1687 nilfs_list_replace_buffer(bh_org, bh);
1688 brelse(bh_org);
1689 if (unlikely(err))
1690 goto failed_bmap;
1691
1692 if (ndatablk > 0)
1693 sc_op->write_data_binfo(sci, &ssp, &binfo);
1694 else
1695 sc_op->write_node_binfo(sci, &ssp, &binfo);
1696
1697 blocknr++;
1698 if (--nblocks == 0) {
1699 finfo = NULL;
1700 if (--nfinfo == 0)
1701 break;
1702 } else if (ndatablk > 0)
1703 ndatablk--;
1704 }
1705 out:
1706 return 0;
1707
1708 failed_bmap:
1709 err = nilfs_handle_bmap_error(err, __func__, inode, sci->sc_super);
1710 return err;
1711}
1712
1713static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1714{
1715 struct nilfs_segment_buffer *segbuf;
1716 int err;
1717
1718 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1719 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1720 if (unlikely(err))
1721 return err;
1722 nilfs_segbuf_fill_in_segsum(segbuf);
1723 }
1724 return 0;
1725}
1726
1727static int
1728nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out)
1729{
1730 struct page *clone_page;
1731 struct buffer_head *bh, *head, *bh2;
1732 void *kaddr;
1733
1734 bh = head = page_buffers(page);
1735
1736 clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0);
1737 if (unlikely(!clone_page))
1738 return -ENOMEM;
1739
1740 bh2 = page_buffers(clone_page);
1741 kaddr = kmap_atomic(page, KM_USER0);
1742 do {
1743 if (list_empty(&bh->b_assoc_buffers))
1744 continue;
1745 get_bh(bh2);
1746 page_cache_get(clone_page); /* for each bh */
1747 memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size);
1748 bh2->b_blocknr = bh->b_blocknr;
1749 list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers);
1750 list_add_tail(&bh->b_assoc_buffers, out);
1751 } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head);
1752 kunmap_atomic(kaddr, KM_USER0);
1753
1754 if (!TestSetPageWriteback(clone_page))
1755 inc_zone_page_state(clone_page, NR_WRITEBACK);
1756 unlock_page(clone_page);
1757
1758 return 0;
1759}
1760
1761static int nilfs_test_page_to_be_frozen(struct page *page)
1762{
1763 struct address_space *mapping = page->mapping;
1764
1765 if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode))
1766 return 0;
1767
1768 if (page_mapped(page)) {
1769 ClearPageChecked(page);
1770 return 1;
1771 }
1772 return PageChecked(page);
1773}
1774
1775static int nilfs_begin_page_io(struct page *page, struct list_head *out)
1776{
1777 if (!page || PageWriteback(page))
1778 /* For split b-tree node pages, this function may be called
1779 twice. We ignore the 2nd or later calls by this check. */
1780 return 0;
1781
1782 lock_page(page);
1783 clear_page_dirty_for_io(page);
1784 set_page_writeback(page);
1785 unlock_page(page);
1786
1787 if (nilfs_test_page_to_be_frozen(page)) {
1788 int err = nilfs_copy_replace_page_buffers(page, out);
1789 if (unlikely(err))
1790 return err;
1791 }
1792 return 0;
1793}
1794
1795static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
1796 struct page **failed_page)
1797{
1798 struct nilfs_segment_buffer *segbuf;
1799 struct page *bd_page = NULL, *fs_page = NULL;
1800 struct list_head *list = &sci->sc_copied_buffers;
1801 int err;
1802
1803 *failed_page = NULL;
1804 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1805 struct buffer_head *bh;
1806
1807 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1808 b_assoc_buffers) {
1809 if (bh->b_page != bd_page) {
1810 if (bd_page) {
1811 lock_page(bd_page);
1812 clear_page_dirty_for_io(bd_page);
1813 set_page_writeback(bd_page);
1814 unlock_page(bd_page);
1815 }
1816 bd_page = bh->b_page;
1817 }
1818 }
1819
1820 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1821 b_assoc_buffers) {
1822 if (bh == sci->sc_super_root) {
1823 if (bh->b_page != bd_page) {
1824 lock_page(bd_page);
1825 clear_page_dirty_for_io(bd_page);
1826 set_page_writeback(bd_page);
1827 unlock_page(bd_page);
1828 bd_page = bh->b_page;
1829 }
1830 break;
1831 }
1832 if (bh->b_page != fs_page) {
1833 err = nilfs_begin_page_io(fs_page, list);
1834 if (unlikely(err)) {
1835 *failed_page = fs_page;
1836 goto out;
1837 }
1838 fs_page = bh->b_page;
1839 }
1840 }
1841 }
1842 if (bd_page) {
1843 lock_page(bd_page);
1844 clear_page_dirty_for_io(bd_page);
1845 set_page_writeback(bd_page);
1846 unlock_page(bd_page);
1847 }
1848 err = nilfs_begin_page_io(fs_page, list);
1849 if (unlikely(err))
1850 *failed_page = fs_page;
1851 out:
1852 return err;
1853}
1854
1855static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1856 struct backing_dev_info *bdi)
1857{
1858 struct nilfs_segment_buffer *segbuf;
1859 struct nilfs_write_info wi;
1860 int err, res;
1861
1862 wi.sb = sci->sc_super;
1863 wi.bh_sr = sci->sc_super_root;
1864 wi.bdi = bdi;
1865
1866 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1867 nilfs_segbuf_prepare_write(segbuf, &wi);
1868 err = nilfs_segbuf_write(segbuf, &wi);
1869
1870 res = nilfs_segbuf_wait(segbuf, &wi);
1871 err = unlikely(err) ? : res;
1872 if (unlikely(err))
1873 return err;
1874 }
1875 return 0;
1876}
1877
1878static int nilfs_page_has_uncleared_buffer(struct page *page)
1879{
1880 struct buffer_head *head, *bh;
1881
1882 head = bh = page_buffers(page);
1883 do {
1884 if (buffer_dirty(bh) && !list_empty(&bh->b_assoc_buffers))
1885 return 1;
1886 bh = bh->b_this_page;
1887 } while (bh != head);
1888 return 0;
1889}
1890
1891static void __nilfs_end_page_io(struct page *page, int err)
1892{
1893 /* BUG_ON(err > 0); */
1894 if (!err) {
1895 if (!nilfs_page_buffers_clean(page))
1896 __set_page_dirty_nobuffers(page);
1897 ClearPageError(page);
1898 } else {
1899 __set_page_dirty_nobuffers(page);
1900 SetPageError(page);
1901 }
1902
1903 if (buffer_nilfs_allocated(page_buffers(page))) {
1904 if (TestClearPageWriteback(page))
1905 dec_zone_page_state(page, NR_WRITEBACK);
1906 } else
1907 end_page_writeback(page);
1908}
1909
1910static void nilfs_end_page_io(struct page *page, int err)
1911{
1912 if (!page)
1913 return;
1914
1915 if (buffer_nilfs_node(page_buffers(page)) &&
1916 nilfs_page_has_uncleared_buffer(page))
1917 /* For b-tree node pages, this function may be called twice
1918 or more because they might be split in a segment.
1919 This check assures that cleanup has been done for all
1920 buffers in a split btnode page. */
1921 return;
1922
1923 __nilfs_end_page_io(page, err);
1924}
1925
1926static void nilfs_clear_copied_buffers(struct list_head *list, int err)
1927{
1928 struct buffer_head *bh, *head;
1929 struct page *page;
1930
1931 while (!list_empty(list)) {
1932 bh = list_entry(list->next, struct buffer_head,
1933 b_assoc_buffers);
1934 page = bh->b_page;
1935 page_cache_get(page);
1936 head = bh = page_buffers(page);
1937 do {
1938 if (!list_empty(&bh->b_assoc_buffers)) {
1939 list_del_init(&bh->b_assoc_buffers);
1940 if (!err) {
1941 set_buffer_uptodate(bh);
1942 clear_buffer_dirty(bh);
1943 clear_buffer_nilfs_volatile(bh);
1944 }
1945 brelse(bh); /* for b_assoc_buffers */
1946 }
1947 } while ((bh = bh->b_this_page) != head);
1948
1949 __nilfs_end_page_io(page, err);
1950 page_cache_release(page);
1951 }
1952}
1953
1954static void nilfs_segctor_abort_write(struct nilfs_sc_info *sci,
1955 struct page *failed_page, int err)
1956{
1957 struct nilfs_segment_buffer *segbuf;
1958 struct page *bd_page = NULL, *fs_page = NULL;
1959
1960 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1961 struct buffer_head *bh;
1962
1963 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1964 b_assoc_buffers) {
1965 if (bh->b_page != bd_page) {
1966 if (bd_page)
1967 end_page_writeback(bd_page);
1968 bd_page = bh->b_page;
1969 }
1970 }
1971
1972 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1973 b_assoc_buffers) {
1974 if (bh == sci->sc_super_root) {
1975 if (bh->b_page != bd_page) {
1976 end_page_writeback(bd_page);
1977 bd_page = bh->b_page;
1978 }
1979 break;
1980 }
1981 if (bh->b_page != fs_page) {
1982 nilfs_end_page_io(fs_page, err);
1983 if (unlikely(fs_page == failed_page))
1984 goto done;
1985 fs_page = bh->b_page;
1986 }
1987 }
1988 }
1989 if (bd_page)
1990 end_page_writeback(bd_page);
1991
1992 nilfs_end_page_io(fs_page, err);
1993 done:
1994 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err);
1995}
1996
1997static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1998 struct nilfs_segment_buffer *segbuf)
1999{
2000 nilfs->ns_segnum = segbuf->sb_segnum;
2001 nilfs->ns_nextnum = segbuf->sb_nextnum;
2002 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
2003 + segbuf->sb_sum.nblocks;
2004 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
2005 nilfs->ns_ctime = segbuf->sb_sum.ctime;
2006}
2007
2008static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
2009{
2010 struct nilfs_segment_buffer *segbuf;
2011 struct page *bd_page = NULL, *fs_page = NULL;
2012 struct nilfs_sb_info *sbi = sci->sc_sbi;
2013 struct the_nilfs *nilfs = sbi->s_nilfs;
2014 int update_sr = (sci->sc_super_root != NULL);
2015
2016 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
2017 struct buffer_head *bh;
2018
2019 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
2020 b_assoc_buffers) {
2021 set_buffer_uptodate(bh);
2022 clear_buffer_dirty(bh);
2023 if (bh->b_page != bd_page) {
2024 if (bd_page)
2025 end_page_writeback(bd_page);
2026 bd_page = bh->b_page;
2027 }
2028 }
2029 /*
2030 * We assume that the buffers which belong to the same page
2031 * continue over the buffer list.
2032 * Under this assumption, the last BHs of pages is
2033 * identifiable by the discontinuity of bh->b_page
2034 * (page != fs_page).
2035 *
2036 * For B-tree node blocks, however, this assumption is not
2037 * guaranteed. The cleanup code of B-tree node pages needs
2038 * special care.
2039 */
2040 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
2041 b_assoc_buffers) {
2042 set_buffer_uptodate(bh);
2043 clear_buffer_dirty(bh);
2044 clear_buffer_nilfs_volatile(bh);
2045 if (bh == sci->sc_super_root) {
2046 if (bh->b_page != bd_page) {
2047 end_page_writeback(bd_page);
2048 bd_page = bh->b_page;
2049 }
2050 break;
2051 }
2052 if (bh->b_page != fs_page) {
2053 nilfs_end_page_io(fs_page, 0);
2054 fs_page = bh->b_page;
2055 }
2056 }
2057
2058 if (!NILFS_SEG_SIMPLEX(&segbuf->sb_sum)) {
2059 if (NILFS_SEG_LOGBGN(&segbuf->sb_sum)) {
2060 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
2061 sci->sc_lseg_stime = jiffies;
2062 }
2063 if (NILFS_SEG_LOGEND(&segbuf->sb_sum))
2064 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
2065 }
2066 }
2067 /*
2068 * Since pages may continue over multiple segment buffers,
2069 * end of the last page must be checked outside of the loop.
2070 */
2071 if (bd_page)
2072 end_page_writeback(bd_page);
2073
2074 nilfs_end_page_io(fs_page, 0);
2075
2076 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, 0);
2077
2078 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
2079
2080 if (nilfs_doing_gc()) {
2081 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
2082 if (update_sr)
2083 nilfs_commit_gcdat_inode(nilfs);
2084 } else {
2085 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
2086 set_nilfs_cond_nongc_write(nilfs);
2087 wake_up(&nilfs->ns_cleanerd_wq);
2088 }
2089
2090 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
2091
2092 segbuf = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
2093 nilfs_set_next_segment(nilfs, segbuf);
2094
2095 if (update_sr) {
2096 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
2097 segbuf->sb_sum.seg_seq, nilfs->ns_cno);
2098
2099 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2100 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
2101 } else
2102 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
2103}
2104
2105static int nilfs_segctor_check_in_files(struct nilfs_sc_info *sci,
2106 struct nilfs_sb_info *sbi)
2107{
2108 struct nilfs_inode_info *ii, *n;
2109 __u64 cno = sbi->s_nilfs->ns_cno;
2110
2111 spin_lock(&sbi->s_inode_lock);
2112 retry:
2113 list_for_each_entry_safe(ii, n, &sbi->s_dirty_files, i_dirty) {
2114 if (!ii->i_bh) {
2115 struct buffer_head *ibh;
2116 int err;
2117
2118 spin_unlock(&sbi->s_inode_lock);
2119 err = nilfs_ifile_get_inode_block(
2120 sbi->s_ifile, ii->vfs_inode.i_ino, &ibh);
2121 if (unlikely(err)) {
2122 nilfs_warning(sbi->s_super, __func__,
2123 "failed to get inode block.\n");
2124 return err;
2125 }
2126 nilfs_mdt_mark_buffer_dirty(ibh);
2127 nilfs_mdt_mark_dirty(sbi->s_ifile);
2128 spin_lock(&sbi->s_inode_lock);
2129 if (likely(!ii->i_bh))
2130 ii->i_bh = ibh;
2131 else
2132 brelse(ibh);
2133 goto retry;
2134 }
2135 ii->i_cno = cno;
2136
2137 clear_bit(NILFS_I_QUEUED, &ii->i_state);
2138 set_bit(NILFS_I_BUSY, &ii->i_state);
2139 list_del(&ii->i_dirty);
2140 list_add_tail(&ii->i_dirty, &sci->sc_dirty_files);
2141 }
2142 spin_unlock(&sbi->s_inode_lock);
2143
2144 NILFS_I(sbi->s_ifile)->i_cno = cno;
2145
2146 return 0;
2147}
2148
2149static void nilfs_segctor_check_out_files(struct nilfs_sc_info *sci,
2150 struct nilfs_sb_info *sbi)
2151{
2152 struct nilfs_transaction_info *ti = current->journal_info;
2153 struct nilfs_inode_info *ii, *n;
2154 __u64 cno = sbi->s_nilfs->ns_cno;
2155
2156 spin_lock(&sbi->s_inode_lock);
2157 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
2158 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
2159 test_bit(NILFS_I_DIRTY, &ii->i_state)) {
2160 /* The current checkpoint number (=nilfs->ns_cno) is
2161 changed between check-in and check-out only if the
2162 super root is written out. So, we can update i_cno
2163 for the inodes that remain in the dirty list. */
2164 ii->i_cno = cno;
2165 continue;
2166 }
2167 clear_bit(NILFS_I_BUSY, &ii->i_state);
2168 brelse(ii->i_bh);
2169 ii->i_bh = NULL;
2170 list_del(&ii->i_dirty);
2171 list_add_tail(&ii->i_dirty, &ti->ti_garbage);
2172 }
2173 spin_unlock(&sbi->s_inode_lock);
2174}
2175
2176/*
2177 * Nasty routines to manipulate active flags on sufile.
2178 * These would be removed in a future release.
2179 */
2180static void nilfs_segctor_reactivate_segments(struct nilfs_sc_info *sci,
2181 struct the_nilfs *nilfs)
2182{
2183 struct nilfs_segment_buffer *segbuf, *last;
2184 struct nilfs_segment_entry *ent, *n;
2185 struct inode *sufile = nilfs->ns_sufile;
2186 struct list_head *head;
2187
2188 last = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
2189 nilfs_for_each_segbuf_before(segbuf, last, &sci->sc_segbufs) {
2190 ent = segbuf->sb_segent;
2191 if (!ent)
2192 break; /* ignore unmapped segments (should check it?)*/
2193 nilfs_segment_usage_set_active(ent->raw_su);
2194 nilfs_close_segment_entry(ent, sufile);
2195 }
2196
2197 head = &sci->sc_active_segments;
2198 list_for_each_entry_safe(ent, n, head, list) {
2199 nilfs_segment_usage_set_active(ent->raw_su);
2200 nilfs_close_segment_entry(ent, sufile);
2201 }
2202
2203 down_write(&nilfs->ns_sem);
2204 head = &nilfs->ns_used_segments;
2205 list_for_each_entry(ent, head, list) {
2206 nilfs_segment_usage_set_volatile_active(ent->raw_su);
2207 }
2208 up_write(&nilfs->ns_sem);
2209}
2210
2211static int nilfs_segctor_deactivate_segments(struct nilfs_sc_info *sci,
2212 struct the_nilfs *nilfs)
2213{
2214 struct nilfs_segment_buffer *segbuf, *last;
2215 struct nilfs_segment_entry *ent;
2216 struct inode *sufile = nilfs->ns_sufile;
2217 struct list_head *head;
2218 int err;
2219
2220 last = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
2221 nilfs_for_each_segbuf_before(segbuf, last, &sci->sc_segbufs) {
2222 /*
2223 * Deactivate ongoing full segments. The last segment is kept
2224 * active because it is a start point of recovery, and is not
2225 * relocatable until the super block points to a newer
2226 * checkpoint.
2227 */
2228 ent = segbuf->sb_segent;
2229 if (!ent)
2230 break; /* ignore unmapped segments (should check it?)*/
2231 err = nilfs_open_segment_entry(ent, sufile);
2232 if (unlikely(err))
2233 goto failed;
2234 nilfs_segment_usage_clear_active(ent->raw_su);
2235 BUG_ON(!buffer_dirty(ent->bh_su));
2236 }
2237
2238 head = &sci->sc_active_segments;
2239 list_for_each_entry(ent, head, list) {
2240 err = nilfs_open_segment_entry(ent, sufile);
2241 if (unlikely(err))
2242 goto failed;
2243 nilfs_segment_usage_clear_active(ent->raw_su);
2244 BUG_ON(!buffer_dirty(ent->bh_su));
2245 }
2246
2247 down_write(&nilfs->ns_sem);
2248 head = &nilfs->ns_used_segments;
2249 list_for_each_entry(ent, head, list) {
2250 /* clear volatile active for segments of older generations */
2251 nilfs_segment_usage_clear_volatile_active(ent->raw_su);
2252 }
2253 up_write(&nilfs->ns_sem);
2254 return 0;
2255
2256 failed:
2257 nilfs_segctor_reactivate_segments(sci, nilfs);
2258 return err;
2259}
2260
2261static void nilfs_segctor_bead_completed_segments(struct nilfs_sc_info *sci)
2262{
2263 struct nilfs_segment_buffer *segbuf, *last;
2264 struct nilfs_segment_entry *ent;
2265
2266 /* move each segbuf->sb_segent to the list of used active segments */
2267 last = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
2268 nilfs_for_each_segbuf_before(segbuf, last, &sci->sc_segbufs) {
2269 ent = segbuf->sb_segent;
2270 if (!ent)
2271 break; /* ignore unmapped segments (should check it?)*/
2272 list_add_tail(&ent->list, &sci->sc_active_segments);
2273 segbuf->sb_segent = NULL;
2274 }
2275}
2276
2277static void
2278__nilfs_segctor_commit_deactivate_segments(struct nilfs_sc_info *sci,
2279 struct the_nilfs *nilfs)
2280
2281{
2282 struct nilfs_segment_entry *ent;
2283
2284 list_splice_init(&sci->sc_active_segments,
2285 nilfs->ns_used_segments.prev);
2286
2287 list_for_each_entry(ent, &nilfs->ns_used_segments, list) {
2288 nilfs_segment_usage_set_volatile_active(ent->raw_su);
2289 /* These segments are kept open */
2290 }
2291}
2292
2293/*
2294 * Main procedure of segment constructor
2295 */
2296static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2297{
2298 struct nilfs_sb_info *sbi = sci->sc_sbi;
2299 struct the_nilfs *nilfs = sbi->s_nilfs;
2300 struct page *failed_page;
2301 int err, has_sr = 0;
2302
2303 sci->sc_stage.scnt = NILFS_ST_INIT;
2304
2305 err = nilfs_segctor_check_in_files(sci, sbi);
2306 if (unlikely(err))
2307 goto out;
2308
2309 if (nilfs_test_metadata_dirty(sbi))
2310 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2311
2312 if (nilfs_segctor_clean(sci))
2313 goto out;
2314
2315 do {
2316 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2317
2318 err = nilfs_segctor_begin_construction(sci, nilfs);
2319 if (unlikely(err))
2320 goto out;
2321
2322 /* Update time stamp */
2323 sci->sc_seg_ctime = get_seconds();
2324
2325 err = nilfs_segctor_collect(sci, nilfs, mode);
2326 if (unlikely(err))
2327 goto failed;
2328
2329 has_sr = (sci->sc_super_root != NULL);
2330
2331 /* Avoid empty segment */
2332 if (sci->sc_stage.scnt == NILFS_ST_DONE &&
2333 NILFS_SEG_EMPTY(&sci->sc_curseg->sb_sum)) {
2334 BUG_ON(mode == SC_LSEG_SR);
2335 nilfs_segctor_end_construction(sci, nilfs, 1);
2336 goto out;
2337 }
2338
2339 err = nilfs_segctor_assign(sci, mode);
2340 if (unlikely(err))
2341 goto failed;
2342
2343 if (has_sr) {
2344 err = nilfs_segctor_deactivate_segments(sci, nilfs);
2345 if (unlikely(err))
2346 goto failed;
2347 }
2348 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2349 nilfs_segctor_fill_in_file_bmap(sci, sbi->s_ifile);
2350
2351 if (has_sr) {
2352 err = nilfs_segctor_fill_in_checkpoint(sci);
2353 if (unlikely(err))
2354 goto failed_to_make_up;
2355
2356 nilfs_segctor_fill_in_super_root(sci, nilfs);
2357 }
2358 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2359
2360 /* Write partial segments */
2361 err = nilfs_segctor_prepare_write(sci, &failed_page);
2362 if (unlikely(err))
2363 goto failed_to_write;
2364
2365 nilfs_segctor_fill_in_checksums(sci, nilfs->ns_crc_seed);
2366
2367 err = nilfs_segctor_write(sci, nilfs->ns_bdi);
2368 if (unlikely(err))
2369 goto failed_to_write;
2370
2371 nilfs_segctor_complete_write(sci);
2372
2373 /* Commit segments */
2374 nilfs_segctor_bead_completed_segments(sci);
2375 if (has_sr) {
2376 down_write(&nilfs->ns_sem);
2377 nilfs_update_last_segment(sbi, 1);
2378 __nilfs_segctor_commit_deactivate_segments(sci, nilfs);
2379 up_write(&nilfs->ns_sem);
2380 nilfs_segctor_commit_free_segments(sci);
2381 nilfs_segctor_clear_metadata_dirty(sci);
2382 }
2383
2384 nilfs_segctor_end_construction(sci, nilfs, 0);
2385
2386 } while (sci->sc_stage.scnt != NILFS_ST_DONE);
2387
2388 /* Clearing sketch data */
2389 if (has_sr && sci->sc_sketch_inode) {
2390 if (i_size_read(sci->sc_sketch_inode) == 0)
2391 clear_bit(NILFS_I_DIRTY,
2392 &NILFS_I(sci->sc_sketch_inode)->i_state);
2393 i_size_write(sci->sc_sketch_inode, 0);
2394 }
2395 out:
2396 nilfs_segctor_destroy_segment_buffers(sci);
2397 nilfs_segctor_check_out_files(sci, sbi);
2398 return err;
2399
2400 failed_to_write:
2401 nilfs_segctor_abort_write(sci, failed_page, err);
2402 nilfs_segctor_cancel_segusage(sci, nilfs->ns_sufile);
2403
2404 failed_to_make_up:
2405 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2406 nilfs_redirty_inodes(&sci->sc_dirty_files);
2407 if (has_sr)
2408 nilfs_segctor_reactivate_segments(sci, nilfs);
2409
2410 failed:
2411 if (nilfs_doing_gc())
2412 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2413 nilfs_segctor_end_construction(sci, nilfs, err);
2414 goto out;
2415}
2416
2417/**
2418 * nilfs_secgtor_start_timer - set timer of background write
2419 * @sci: nilfs_sc_info
2420 *
2421 * If the timer has already been set, it ignores the new request.
2422 * This function MUST be called within a section locking the segment
2423 * semaphore.
2424 */
2425static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2426{
2427 spin_lock(&sci->sc_state_lock);
2428 if (sci->sc_timer && !(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2429 sci->sc_timer->expires = jiffies + sci->sc_interval;
2430 add_timer(sci->sc_timer);
2431 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2432 }
2433 spin_unlock(&sci->sc_state_lock);
2434}
2435
2436static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2437{
2438 spin_lock(&sci->sc_state_lock);
2439 if (!(sci->sc_flush_request & (1 << bn))) {
2440 unsigned long prev_req = sci->sc_flush_request;
2441
2442 sci->sc_flush_request |= (1 << bn);
2443 if (!prev_req)
2444 wake_up(&sci->sc_wait_daemon);
2445 }
2446 spin_unlock(&sci->sc_state_lock);
2447}
2448
2449/**
2450 * nilfs_flush_segment - trigger a segment construction for resource control
2451 * @sb: super block
2452 * @ino: inode number of the file to be flushed out.
2453 */
2454void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2455{
2456 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2457 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2458
2459 if (!sci || nilfs_doing_construction())
2460 return;
2461 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2462 /* assign bit 0 to data files */
2463}
2464
2465int nilfs_segctor_add_segments_to_be_freed(struct nilfs_sc_info *sci,
2466 __u64 *segnum, size_t nsegs)
2467{
2468 struct nilfs_segment_entry *ent;
2469 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
2470 struct inode *sufile = nilfs->ns_sufile;
2471 LIST_HEAD(list);
2472 __u64 *pnum;
2473 const char *flag_name;
2474 size_t i;
2475 int err, err2 = 0;
2476
2477 for (pnum = segnum, i = 0; i < nsegs; pnum++, i++) {
2478 ent = nilfs_alloc_segment_entry(*pnum);
2479 if (unlikely(!ent)) {
2480 err = -ENOMEM;
2481 goto failed;
2482 }
2483 list_add_tail(&ent->list, &list);
2484
2485 err = nilfs_open_segment_entry(ent, sufile);
2486 if (unlikely(err))
2487 goto failed;
2488
2489 if (unlikely(le32_to_cpu(ent->raw_su->su_flags) !=
2490 (1UL << NILFS_SEGMENT_USAGE_DIRTY))) {
2491 if (nilfs_segment_usage_clean(ent->raw_su))
2492 flag_name = "clean";
2493 else if (nilfs_segment_usage_active(ent->raw_su))
2494 flag_name = "active";
2495 else if (nilfs_segment_usage_volatile_active(
2496 ent->raw_su))
2497 flag_name = "volatile active";
2498 else if (!nilfs_segment_usage_dirty(ent->raw_su))
2499 flag_name = "non-dirty";
2500 else
2501 flag_name = "erroneous";
2502
2503 printk(KERN_ERR
2504 "NILFS: %s segment is requested to be cleaned "
2505 "(segnum=%llu)\n",
2506 flag_name, (unsigned long long)ent->segnum);
2507 err2 = -EINVAL;
2508 }
2509 nilfs_close_segment_entry(ent, sufile);
2510 }
2511 if (unlikely(err2)) {
2512 err = err2;
2513 goto failed;
2514 }
2515 list_splice(&list, sci->sc_cleaning_segments.prev);
2516 return 0;
2517
2518 failed:
2519 nilfs_dispose_segment_list(&list);
2520 return err;
2521}
2522
2523void nilfs_segctor_clear_segments_to_be_freed(struct nilfs_sc_info *sci)
2524{
2525 nilfs_dispose_segment_list(&sci->sc_cleaning_segments);
2526}
2527
2528struct nilfs_segctor_wait_request {
2529 wait_queue_t wq;
2530 __u32 seq;
2531 int err;
2532 atomic_t done;
2533};
2534
2535static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2536{
2537 struct nilfs_segctor_wait_request wait_req;
2538 int err = 0;
2539
2540 spin_lock(&sci->sc_state_lock);
2541 init_wait(&wait_req.wq);
2542 wait_req.err = 0;
2543 atomic_set(&wait_req.done, 0);
2544 wait_req.seq = ++sci->sc_seq_request;
2545 spin_unlock(&sci->sc_state_lock);
2546
2547 init_waitqueue_entry(&wait_req.wq, current);
2548 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2549 set_current_state(TASK_INTERRUPTIBLE);
2550 wake_up(&sci->sc_wait_daemon);
2551
2552 for (;;) {
2553 if (atomic_read(&wait_req.done)) {
2554 err = wait_req.err;
2555 break;
2556 }
2557 if (!signal_pending(current)) {
2558 schedule();
2559 continue;
2560 }
2561 err = -ERESTARTSYS;
2562 break;
2563 }
2564 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2565 return err;
2566}
2567
2568static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2569{
2570 struct nilfs_segctor_wait_request *wrq, *n;
2571 unsigned long flags;
2572
2573 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2574 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2575 wq.task_list) {
2576 if (!atomic_read(&wrq->done) &&
2577 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2578 wrq->err = err;
2579 atomic_set(&wrq->done, 1);
2580 }
2581 if (atomic_read(&wrq->done)) {
2582 wrq->wq.func(&wrq->wq,
2583 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2584 0, NULL);
2585 }
2586 }
2587 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2588}
2589
2590/**
2591 * nilfs_construct_segment - construct a logical segment
2592 * @sb: super block
2593 *
2594 * Return Value: On success, 0 is retured. On errors, one of the following
2595 * negative error code is returned.
2596 *
2597 * %-EROFS - Read only filesystem.
2598 *
2599 * %-EIO - I/O error
2600 *
2601 * %-ENOSPC - No space left on device (only in a panic state).
2602 *
2603 * %-ERESTARTSYS - Interrupted.
2604 *
2605 * %-ENOMEM - Insufficient memory available.
2606 */
2607int nilfs_construct_segment(struct super_block *sb)
2608{
2609 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2610 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2611 struct nilfs_transaction_info *ti;
2612 int err;
2613
2614 if (!sci)
2615 return -EROFS;
2616
2617 /* A call inside transactions causes a deadlock. */
2618 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2619
2620 err = nilfs_segctor_sync(sci);
2621 return err;
2622}
2623
2624/**
2625 * nilfs_construct_dsync_segment - construct a data-only logical segment
2626 * @sb: super block
2627 * @inode: the inode whose data blocks should be written out
2628 *
2629 * Return Value: On success, 0 is retured. On errors, one of the following
2630 * negative error code is returned.
2631 *
2632 * %-EROFS - Read only filesystem.
2633 *
2634 * %-EIO - I/O error
2635 *
2636 * %-ENOSPC - No space left on device (only in a panic state).
2637 *
2638 * %-ERESTARTSYS - Interrupted.
2639 *
2640 * %-ENOMEM - Insufficient memory available.
2641 */
2642int nilfs_construct_dsync_segment(struct super_block *sb,
2643 struct inode *inode)
2644{
2645 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2646 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2647 struct nilfs_inode_info *ii;
2648 struct nilfs_transaction_info ti;
2649 int err = 0;
2650
2651 if (!sci)
2652 return -EROFS;
2653
2654 nilfs_transaction_lock(sbi, &ti, 0);
2655
2656 ii = NILFS_I(inode);
2657 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
2658 nilfs_test_opt(sbi, STRICT_ORDER) ||
2659 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2660 nilfs_discontinued(sbi->s_nilfs)) {
2661 nilfs_transaction_unlock(sbi);
2662 err = nilfs_segctor_sync(sci);
2663 return err;
2664 }
2665
2666 spin_lock(&sbi->s_inode_lock);
2667 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2668 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2669 spin_unlock(&sbi->s_inode_lock);
2670 nilfs_transaction_unlock(sbi);
2671 return 0;
2672 }
2673 spin_unlock(&sbi->s_inode_lock);
2674 sci->sc_stage.dirty_file_ptr = ii;
2675
2676 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2677
2678 nilfs_transaction_unlock(sbi);
2679 return err;
2680}
2681
2682struct nilfs_segctor_req {
2683 int mode;
2684 __u32 seq_accepted;
2685 int sc_err; /* construction failure */
2686 int sb_err; /* super block writeback failure */
2687};
2688
2689#define FLUSH_FILE_BIT (0x1) /* data file only */
2690#define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2691
2692static void nilfs_segctor_accept(struct nilfs_sc_info *sci,
2693 struct nilfs_segctor_req *req)
2694{
2695 BUG_ON(!sci);
2696
2697 req->sc_err = req->sb_err = 0;
2698 spin_lock(&sci->sc_state_lock);
2699 req->seq_accepted = sci->sc_seq_request;
2700 spin_unlock(&sci->sc_state_lock);
2701
2702 if (sci->sc_timer)
2703 del_timer_sync(sci->sc_timer);
2704}
2705
2706static void nilfs_segctor_notify(struct nilfs_sc_info *sci,
2707 struct nilfs_segctor_req *req)
2708{
2709 /* Clear requests (even when the construction failed) */
2710 spin_lock(&sci->sc_state_lock);
2711
2712 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2713
2714 if (req->mode == SC_LSEG_SR) {
2715 sci->sc_seq_done = req->seq_accepted;
2716 nilfs_segctor_wakeup(sci, req->sc_err ? : req->sb_err);
2717 sci->sc_flush_request = 0;
2718 } else if (req->mode == SC_FLUSH_FILE)
2719 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2720 else if (req->mode == SC_FLUSH_DAT)
2721 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2722
2723 spin_unlock(&sci->sc_state_lock);
2724}
2725
2726static int nilfs_segctor_construct(struct nilfs_sc_info *sci,
2727 struct nilfs_segctor_req *req)
2728{
2729 struct nilfs_sb_info *sbi = sci->sc_sbi;
2730 struct the_nilfs *nilfs = sbi->s_nilfs;
2731 int err = 0;
2732
2733 if (nilfs_discontinued(nilfs))
2734 req->mode = SC_LSEG_SR;
2735 if (!nilfs_segctor_confirm(sci)) {
2736 err = nilfs_segctor_do_construct(sci, req->mode);
2737 req->sc_err = err;
2738 }
2739 if (likely(!err)) {
2740 if (req->mode != SC_FLUSH_DAT)
2741 atomic_set(&nilfs->ns_ndirtyblks, 0);
2742 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2743 nilfs_discontinued(nilfs)) {
2744 down_write(&nilfs->ns_sem);
2745 req->sb_err = nilfs_commit_super(sbi);
2746 up_write(&nilfs->ns_sem);
2747 }
2748 }
2749 return err;
2750}
2751
2752static void nilfs_construction_timeout(unsigned long data)
2753{
2754 struct task_struct *p = (struct task_struct *)data;
2755 wake_up_process(p);
2756}
2757
2758static void
2759nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2760{
2761 struct nilfs_inode_info *ii, *n;
2762
2763 list_for_each_entry_safe(ii, n, head, i_dirty) {
2764 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2765 continue;
2766 hlist_del_init(&ii->vfs_inode.i_hash);
2767 list_del_init(&ii->i_dirty);
2768 nilfs_clear_gcinode(&ii->vfs_inode);
2769 }
2770}
2771
2772int nilfs_clean_segments(struct super_block *sb, void __user *argp)
2773{
2774 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2775 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2776 struct the_nilfs *nilfs = sbi->s_nilfs;
2777 struct nilfs_transaction_info ti;
2778 struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
2779 int err;
2780
2781 if (unlikely(!sci))
2782 return -EROFS;
2783
2784 nilfs_transaction_lock(sbi, &ti, 1);
2785
2786 err = nilfs_init_gcdat_inode(nilfs);
2787 if (unlikely(err))
2788 goto out_unlock;
2789 err = nilfs_ioctl_prepare_clean_segments(nilfs, argp);
2790 if (unlikely(err))
2791 goto out_unlock;
2792
2793 list_splice_init(&nilfs->ns_gc_inodes, sci->sc_gc_inodes.prev);
2794
2795 for (;;) {
2796 nilfs_segctor_accept(sci, &req);
2797 err = nilfs_segctor_construct(sci, &req);
2798 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2799 nilfs_segctor_notify(sci, &req);
2800
2801 if (likely(!err))
2802 break;
2803
2804 nilfs_warning(sb, __func__,
2805 "segment construction failed. (err=%d)", err);
2806 set_current_state(TASK_INTERRUPTIBLE);
2807 schedule_timeout(sci->sc_interval);
2808 }
2809
2810 out_unlock:
2811 nilfs_clear_gcdat_inode(nilfs);
2812 nilfs_transaction_unlock(sbi);
2813 return err;
2814}
2815
2816static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2817{
2818 struct nilfs_sb_info *sbi = sci->sc_sbi;
2819 struct nilfs_transaction_info ti;
2820 struct nilfs_segctor_req req = { .mode = mode };
2821
2822 nilfs_transaction_lock(sbi, &ti, 0);
2823
2824 nilfs_segctor_accept(sci, &req);
2825 nilfs_segctor_construct(sci, &req);
2826 nilfs_segctor_notify(sci, &req);
2827
2828 /*
2829 * Unclosed segment should be retried. We do this using sc_timer.
2830 * Timeout of sc_timer will invoke complete construction which leads
2831 * to close the current logical segment.
2832 */
2833 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2834 nilfs_segctor_start_timer(sci);
2835
2836 nilfs_transaction_unlock(sbi);
2837}
2838
2839static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2840{
2841 int mode = 0;
2842 int err;
2843
2844 spin_lock(&sci->sc_state_lock);
2845 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2846 SC_FLUSH_DAT : SC_FLUSH_FILE;
2847 spin_unlock(&sci->sc_state_lock);
2848
2849 if (mode) {
2850 err = nilfs_segctor_do_construct(sci, mode);
2851
2852 spin_lock(&sci->sc_state_lock);
2853 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2854 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2855 spin_unlock(&sci->sc_state_lock);
2856 }
2857 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2858}
2859
2860static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2861{
2862 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2863 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2864 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2865 return SC_FLUSH_FILE;
2866 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2867 return SC_FLUSH_DAT;
2868 }
2869 return SC_LSEG_SR;
2870}
2871
2872/**
2873 * nilfs_segctor_thread - main loop of the segment constructor thread.
2874 * @arg: pointer to a struct nilfs_sc_info.
2875 *
2876 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2877 * to execute segment constructions.
2878 */
2879static int nilfs_segctor_thread(void *arg)
2880{
2881 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2882 struct timer_list timer;
2883 int timeout = 0;
2884
2885 init_timer(&timer);
2886 timer.data = (unsigned long)current;
2887 timer.function = nilfs_construction_timeout;
2888 sci->sc_timer = &timer;
2889
2890 /* start sync. */
2891 sci->sc_task = current;
2892 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2893 printk(KERN_INFO
2894 "segctord starting. Construction interval = %lu seconds, "
2895 "CP frequency < %lu seconds\n",
2896 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2897
2898 spin_lock(&sci->sc_state_lock);
2899 loop:
2900 for (;;) {
2901 int mode;
2902
2903 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2904 goto end_thread;
2905
2906 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2907 mode = SC_LSEG_SR;
2908 else if (!sci->sc_flush_request)
2909 break;
2910 else
2911 mode = nilfs_segctor_flush_mode(sci);
2912
2913 spin_unlock(&sci->sc_state_lock);
2914 nilfs_segctor_thread_construct(sci, mode);
2915 spin_lock(&sci->sc_state_lock);
2916 timeout = 0;
2917 }
2918
2919
2920 if (freezing(current)) {
2921 spin_unlock(&sci->sc_state_lock);
2922 refrigerator();
2923 spin_lock(&sci->sc_state_lock);
2924 } else {
2925 DEFINE_WAIT(wait);
2926 int should_sleep = 1;
2927
2928 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2929 TASK_INTERRUPTIBLE);
2930
2931 if (sci->sc_seq_request != sci->sc_seq_done)
2932 should_sleep = 0;
2933 else if (sci->sc_flush_request)
2934 should_sleep = 0;
2935 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2936 should_sleep = time_before(jiffies,
2937 sci->sc_timer->expires);
2938
2939 if (should_sleep) {
2940 spin_unlock(&sci->sc_state_lock);
2941 schedule();
2942 spin_lock(&sci->sc_state_lock);
2943 }
2944 finish_wait(&sci->sc_wait_daemon, &wait);
2945 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2946 time_after_eq(jiffies, sci->sc_timer->expires));
2947 }
2948 goto loop;
2949
2950 end_thread:
2951 spin_unlock(&sci->sc_state_lock);
2952 del_timer_sync(sci->sc_timer);
2953 sci->sc_timer = NULL;
2954
2955 /* end sync. */
2956 sci->sc_task = NULL;
2957 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2958 return 0;
2959}
2960
2961static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2962{
2963 struct task_struct *t;
2964
2965 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2966 if (IS_ERR(t)) {
2967 int err = PTR_ERR(t);
2968
2969 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2970 err);
2971 return err;
2972 }
2973 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2974 return 0;
2975}
2976
2977static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2978{
2979 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2980
2981 while (sci->sc_task) {
2982 wake_up(&sci->sc_wait_daemon);
2983 spin_unlock(&sci->sc_state_lock);
2984 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2985 spin_lock(&sci->sc_state_lock);
2986 }
2987}
2988
2989static int nilfs_segctor_init(struct nilfs_sc_info *sci,
2990 struct nilfs_recovery_info *ri)
2991{
2992 int err;
2993 struct inode *inode = nilfs_iget(sci->sc_super, NILFS_SKETCH_INO);
2994
2995 sci->sc_sketch_inode = IS_ERR(inode) ? NULL : inode;
2996 if (sci->sc_sketch_inode)
2997 i_size_write(sci->sc_sketch_inode, 0);
2998
2999 sci->sc_seq_done = sci->sc_seq_request;
3000 if (ri)
3001 list_splice_init(&ri->ri_used_segments,
3002 sci->sc_active_segments.prev);
3003
3004 err = nilfs_segctor_start_thread(sci);
3005 if (err) {
3006 if (ri)
3007 list_splice_init(&sci->sc_active_segments,
3008 ri->ri_used_segments.prev);
3009 if (sci->sc_sketch_inode) {
3010 iput(sci->sc_sketch_inode);
3011 sci->sc_sketch_inode = NULL;
3012 }
3013 }
3014 return err;
3015}
3016
3017/*
3018 * Setup & clean-up functions
3019 */
3020static struct nilfs_sc_info *nilfs_segctor_new(struct nilfs_sb_info *sbi)
3021{
3022 struct nilfs_sc_info *sci;
3023
3024 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
3025 if (!sci)
3026 return NULL;
3027
3028 sci->sc_sbi = sbi;
3029 sci->sc_super = sbi->s_super;
3030
3031 init_waitqueue_head(&sci->sc_wait_request);
3032 init_waitqueue_head(&sci->sc_wait_daemon);
3033 init_waitqueue_head(&sci->sc_wait_task);
3034 spin_lock_init(&sci->sc_state_lock);
3035 INIT_LIST_HEAD(&sci->sc_dirty_files);
3036 INIT_LIST_HEAD(&sci->sc_segbufs);
3037 INIT_LIST_HEAD(&sci->sc_gc_inodes);
3038 INIT_LIST_HEAD(&sci->sc_active_segments);
3039 INIT_LIST_HEAD(&sci->sc_cleaning_segments);
3040 INIT_LIST_HEAD(&sci->sc_copied_buffers);
3041
3042 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
3043 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
3044 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
3045
3046 if (sbi->s_interval)
3047 sci->sc_interval = sbi->s_interval;
3048 if (sbi->s_watermark)
3049 sci->sc_watermark = sbi->s_watermark;
3050 return sci;
3051}
3052
3053static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
3054{
3055 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
3056
3057 /* The segctord thread was stopped and its timer was removed.
3058 But some tasks remain. */
3059 do {
3060 struct nilfs_sb_info *sbi = sci->sc_sbi;
3061 struct nilfs_transaction_info ti;
3062 struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
3063
3064 nilfs_transaction_lock(sbi, &ti, 0);
3065 nilfs_segctor_accept(sci, &req);
3066 ret = nilfs_segctor_construct(sci, &req);
3067 nilfs_segctor_notify(sci, &req);
3068 nilfs_transaction_unlock(sbi);
3069
3070 } while (ret && retrycount-- > 0);
3071}
3072
3073/**
3074 * nilfs_segctor_destroy - destroy the segment constructor.
3075 * @sci: nilfs_sc_info
3076 *
3077 * nilfs_segctor_destroy() kills the segctord thread and frees
3078 * the nilfs_sc_info struct.
3079 * Caller must hold the segment semaphore.
3080 */
3081static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
3082{
3083 struct nilfs_sb_info *sbi = sci->sc_sbi;
3084 int flag;
3085
3086 up_write(&sbi->s_nilfs->ns_segctor_sem);
3087
3088 spin_lock(&sci->sc_state_lock);
3089 nilfs_segctor_kill_thread(sci);
3090 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
3091 || sci->sc_seq_request != sci->sc_seq_done);
3092 spin_unlock(&sci->sc_state_lock);
3093
3094 if (flag || nilfs_segctor_confirm(sci))
3095 nilfs_segctor_write_out(sci);
3096
3097 BUG_ON(!list_empty(&sci->sc_copied_buffers));
3098
3099 if (!list_empty(&sci->sc_dirty_files)) {
3100 nilfs_warning(sbi->s_super, __func__,
3101 "dirty file(s) after the final construction\n");
3102 nilfs_dispose_list(sbi, &sci->sc_dirty_files, 1);
3103 }
3104 if (!list_empty(&sci->sc_active_segments))
3105 nilfs_dispose_segment_list(&sci->sc_active_segments);
3106
3107 if (!list_empty(&sci->sc_cleaning_segments))
3108 nilfs_dispose_segment_list(&sci->sc_cleaning_segments);
3109
3110 BUG_ON(!list_empty(&sci->sc_segbufs));
3111
3112 if (sci->sc_sketch_inode) {
3113 iput(sci->sc_sketch_inode);
3114 sci->sc_sketch_inode = NULL;
3115 }
3116 down_write(&sbi->s_nilfs->ns_segctor_sem);
3117
3118 kfree(sci);
3119}
3120
3121/**
3122 * nilfs_attach_segment_constructor - attach a segment constructor
3123 * @sbi: nilfs_sb_info
3124 * @ri: nilfs_recovery_info
3125 *
3126 * nilfs_attach_segment_constructor() allocates a struct nilfs_sc_info,
3127 * initilizes it, and starts the segment constructor.
3128 *
3129 * Return Value: On success, 0 is returned. On error, one of the following
3130 * negative error code is returned.
3131 *
3132 * %-ENOMEM - Insufficient memory available.
3133 */
3134int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi,
3135 struct nilfs_recovery_info *ri)
3136{
3137 struct the_nilfs *nilfs = sbi->s_nilfs;
3138 int err;
3139
3140 /* Each field of nilfs_segctor is cleared through the initialization
3141 of super-block info */
3142 sbi->s_sc_info = nilfs_segctor_new(sbi);
3143 if (!sbi->s_sc_info)
3144 return -ENOMEM;
3145
3146 nilfs_attach_writer(nilfs, sbi);
3147 err = nilfs_segctor_init(NILFS_SC(sbi), ri);
3148 if (err) {
3149 nilfs_detach_writer(nilfs, sbi);
3150 kfree(sbi->s_sc_info);
3151 sbi->s_sc_info = NULL;
3152 }
3153 return err;
3154}
3155
3156/**
3157 * nilfs_detach_segment_constructor - destroy the segment constructor
3158 * @sbi: nilfs_sb_info
3159 *
3160 * nilfs_detach_segment_constructor() kills the segment constructor daemon,
3161 * frees the struct nilfs_sc_info, and destroy the dirty file list.
3162 */
3163void nilfs_detach_segment_constructor(struct nilfs_sb_info *sbi)
3164{
3165 struct the_nilfs *nilfs = sbi->s_nilfs;
3166 LIST_HEAD(garbage_list);
3167
3168 down_write(&nilfs->ns_segctor_sem);
3169 if (NILFS_SC(sbi)) {
3170 nilfs_segctor_destroy(NILFS_SC(sbi));
3171 sbi->s_sc_info = NULL;
3172 }
3173
3174 /* Force to free the list of dirty files */
3175 spin_lock(&sbi->s_inode_lock);
3176 if (!list_empty(&sbi->s_dirty_files)) {
3177 list_splice_init(&sbi->s_dirty_files, &garbage_list);
3178 nilfs_warning(sbi->s_super, __func__,
3179 "Non empty dirty list after the last "
3180 "segment construction\n");
3181 }
3182 spin_unlock(&sbi->s_inode_lock);
3183 up_write(&nilfs->ns_segctor_sem);
3184
3185 nilfs_dispose_list(sbi, &garbage_list, 1);
3186 nilfs_detach_writer(nilfs, sbi);
3187}
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