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1/*
2 * segment.c - NILFS segment constructor.
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
21 *
22 */
23
24#include <linux/pagemap.h>
25#include <linux/buffer_head.h>
26#include <linux/writeback.h>
27#include <linux/bio.h>
28#include <linux/completion.h>
29#include <linux/blkdev.h>
30#include <linux/backing-dev.h>
31#include <linux/freezer.h>
32#include <linux/kthread.h>
33#include <linux/crc32.h>
34#include <linux/pagevec.h>
35#include <linux/slab.h>
36#include "nilfs.h"
37#include "btnode.h"
38#include "page.h"
39#include "segment.h"
40#include "sufile.h"
41#include "cpfile.h"
42#include "ifile.h"
43#include "segbuf.h"
44
45
46/*
47 * Segment constructor
48 */
49#define SC_N_INODEVEC 16 /* Size of locally allocated inode vector */
50
51#define SC_MAX_SEGDELTA 64 /* Upper limit of the number of segments
52 appended in collection retry loop */
53
54/* Construction mode */
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_IFILE,
71 NILFS_ST_CPFILE,
72 NILFS_ST_SUFILE,
73 NILFS_ST_DAT,
74 NILFS_ST_SR, /* Super root */
75 NILFS_ST_DSYNC, /* Data sync blocks */
76 NILFS_ST_DONE,
77};
78
79/* State flags of collection */
80#define NILFS_CF_NODE 0x0001 /* Collecting node blocks */
81#define NILFS_CF_IFILE_STARTED 0x0002 /* IFILE stage has started */
82#define NILFS_CF_SUFREED 0x0004 /* segment usages has been freed */
83#define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED)
84
85/* Operations depending on the construction mode and file type */
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 the_nilfs *, struct list_head *, int);
108
109#define nilfs_cnt32_gt(a, b) \
110 (typecheck(__u32, a) && typecheck(__u32, b) && \
111 ((__s32)(b) - (__s32)(a) < 0))
112#define nilfs_cnt32_ge(a, b) \
113 (typecheck(__u32, a) && typecheck(__u32, b) && \
114 ((__s32)(a) - (__s32)(b) >= 0))
115#define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a)
116#define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a)
117
118static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
119{
120 struct nilfs_transaction_info *cur_ti = current->journal_info;
121 void *save = NULL;
122
123 if (cur_ti) {
124 if (cur_ti->ti_magic == NILFS_TI_MAGIC)
125 return ++cur_ti->ti_count;
126 else {
127 /*
128 * If journal_info field is occupied by other FS,
129 * it is saved and will be restored on
130 * nilfs_transaction_commit().
131 */
132 printk(KERN_WARNING
133 "NILFS warning: journal info from a different "
134 "FS\n");
135 save = current->journal_info;
136 }
137 }
138 if (!ti) {
139 ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
140 if (!ti)
141 return -ENOMEM;
142 ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
143 } else {
144 ti->ti_flags = 0;
145 }
146 ti->ti_count = 0;
147 ti->ti_save = save;
148 ti->ti_magic = NILFS_TI_MAGIC;
149 current->journal_info = ti;
150 return 0;
151}
152
153/**
154 * nilfs_transaction_begin - start indivisible file operations.
155 * @sb: super block
156 * @ti: nilfs_transaction_info
157 * @vacancy_check: flags for vacancy rate checks
158 *
159 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
160 * the segment semaphore, to make a segment construction and write tasks
161 * exclusive. The function is used with nilfs_transaction_commit() in pairs.
162 * The region enclosed by these two functions can be nested. To avoid a
163 * deadlock, the semaphore is only acquired or released in the outermost call.
164 *
165 * This function allocates a nilfs_transaction_info struct to keep context
166 * information on it. It is initialized and hooked onto the current task in
167 * the outermost call. If a pre-allocated struct is given to @ti, it is used
168 * instead; otherwise a new struct is assigned from a slab.
169 *
170 * When @vacancy_check flag is set, this function will check the amount of
171 * free space, and will wait for the GC to reclaim disk space if low capacity.
172 *
173 * Return Value: On success, 0 is returned. On error, one of the following
174 * negative error code is returned.
175 *
176 * %-ENOMEM - Insufficient memory available.
177 *
178 * %-ENOSPC - No space left on device
179 */
180int nilfs_transaction_begin(struct super_block *sb,
181 struct nilfs_transaction_info *ti,
182 int vacancy_check)
183{
184 struct the_nilfs *nilfs;
185 int ret = nilfs_prepare_segment_lock(ti);
186
187 if (unlikely(ret < 0))
188 return ret;
189 if (ret > 0)
190 return 0;
191
192 vfs_check_frozen(sb, SB_FREEZE_WRITE);
193
194 nilfs = sb->s_fs_info;
195 down_read(&nilfs->ns_segctor_sem);
196 if (vacancy_check && nilfs_near_disk_full(nilfs)) {
197 up_read(&nilfs->ns_segctor_sem);
198 ret = -ENOSPC;
199 goto failed;
200 }
201 return 0;
202
203 failed:
204 ti = current->journal_info;
205 current->journal_info = ti->ti_save;
206 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
207 kmem_cache_free(nilfs_transaction_cachep, ti);
208 return ret;
209}
210
211/**
212 * nilfs_transaction_commit - commit indivisible file operations.
213 * @sb: super block
214 *
215 * nilfs_transaction_commit() releases the read semaphore which is
216 * acquired by nilfs_transaction_begin(). This is only performed
217 * in outermost call of this function. If a commit flag is set,
218 * nilfs_transaction_commit() sets a timer to start the segment
219 * constructor. If a sync flag is set, it starts construction
220 * directly.
221 */
222int nilfs_transaction_commit(struct super_block *sb)
223{
224 struct nilfs_transaction_info *ti = current->journal_info;
225 struct the_nilfs *nilfs = sb->s_fs_info;
226 int err = 0;
227
228 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
229 ti->ti_flags |= NILFS_TI_COMMIT;
230 if (ti->ti_count > 0) {
231 ti->ti_count--;
232 return 0;
233 }
234 if (nilfs->ns_writer) {
235 struct nilfs_sc_info *sci = nilfs->ns_writer;
236
237 if (ti->ti_flags & NILFS_TI_COMMIT)
238 nilfs_segctor_start_timer(sci);
239 if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark)
240 nilfs_segctor_do_flush(sci, 0);
241 }
242 up_read(&nilfs->ns_segctor_sem);
243 current->journal_info = ti->ti_save;
244
245 if (ti->ti_flags & NILFS_TI_SYNC)
246 err = nilfs_construct_segment(sb);
247 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
248 kmem_cache_free(nilfs_transaction_cachep, ti);
249 return err;
250}
251
252void nilfs_transaction_abort(struct super_block *sb)
253{
254 struct nilfs_transaction_info *ti = current->journal_info;
255 struct the_nilfs *nilfs = sb->s_fs_info;
256
257 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
258 if (ti->ti_count > 0) {
259 ti->ti_count--;
260 return;
261 }
262 up_read(&nilfs->ns_segctor_sem);
263
264 current->journal_info = ti->ti_save;
265 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
266 kmem_cache_free(nilfs_transaction_cachep, ti);
267}
268
269void nilfs_relax_pressure_in_lock(struct super_block *sb)
270{
271 struct the_nilfs *nilfs = sb->s_fs_info;
272 struct nilfs_sc_info *sci = nilfs->ns_writer;
273
274 if (!sci || !sci->sc_flush_request)
275 return;
276
277 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
278 up_read(&nilfs->ns_segctor_sem);
279
280 down_write(&nilfs->ns_segctor_sem);
281 if (sci->sc_flush_request &&
282 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
283 struct nilfs_transaction_info *ti = current->journal_info;
284
285 ti->ti_flags |= NILFS_TI_WRITER;
286 nilfs_segctor_do_immediate_flush(sci);
287 ti->ti_flags &= ~NILFS_TI_WRITER;
288 }
289 downgrade_write(&nilfs->ns_segctor_sem);
290}
291
292static void nilfs_transaction_lock(struct super_block *sb,
293 struct nilfs_transaction_info *ti,
294 int gcflag)
295{
296 struct nilfs_transaction_info *cur_ti = current->journal_info;
297 struct the_nilfs *nilfs = sb->s_fs_info;
298 struct nilfs_sc_info *sci = nilfs->ns_writer;
299
300 WARN_ON(cur_ti);
301 ti->ti_flags = NILFS_TI_WRITER;
302 ti->ti_count = 0;
303 ti->ti_save = cur_ti;
304 ti->ti_magic = NILFS_TI_MAGIC;
305 INIT_LIST_HEAD(&ti->ti_garbage);
306 current->journal_info = ti;
307
308 for (;;) {
309 down_write(&nilfs->ns_segctor_sem);
310 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags))
311 break;
312
313 nilfs_segctor_do_immediate_flush(sci);
314
315 up_write(&nilfs->ns_segctor_sem);
316 yield();
317 }
318 if (gcflag)
319 ti->ti_flags |= NILFS_TI_GC;
320}
321
322static void nilfs_transaction_unlock(struct super_block *sb)
323{
324 struct nilfs_transaction_info *ti = current->journal_info;
325 struct the_nilfs *nilfs = sb->s_fs_info;
326
327 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
328 BUG_ON(ti->ti_count > 0);
329
330 up_write(&nilfs->ns_segctor_sem);
331 current->journal_info = ti->ti_save;
332 if (!list_empty(&ti->ti_garbage))
333 nilfs_dispose_list(nilfs, &ti->ti_garbage, 0);
334}
335
336static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
337 struct nilfs_segsum_pointer *ssp,
338 unsigned bytes)
339{
340 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
341 unsigned blocksize = sci->sc_super->s_blocksize;
342 void *p;
343
344 if (unlikely(ssp->offset + bytes > blocksize)) {
345 ssp->offset = 0;
346 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
347 &segbuf->sb_segsum_buffers));
348 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
349 }
350 p = ssp->bh->b_data + ssp->offset;
351 ssp->offset += bytes;
352 return p;
353}
354
355/**
356 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
357 * @sci: nilfs_sc_info
358 */
359static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
360{
361 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
362 struct buffer_head *sumbh;
363 unsigned sumbytes;
364 unsigned flags = 0;
365 int err;
366
367 if (nilfs_doing_gc())
368 flags = NILFS_SS_GC;
369 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno);
370 if (unlikely(err))
371 return err;
372
373 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
374 sumbytes = segbuf->sb_sum.sumbytes;
375 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
376 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
377 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
378 return 0;
379}
380
381static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
382{
383 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
384 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
385 return -E2BIG; /* The current segment is filled up
386 (internal code) */
387 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
388 return nilfs_segctor_reset_segment_buffer(sci);
389}
390
391static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
392{
393 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
394 int err;
395
396 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
397 err = nilfs_segctor_feed_segment(sci);
398 if (err)
399 return err;
400 segbuf = sci->sc_curseg;
401 }
402 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root);
403 if (likely(!err))
404 segbuf->sb_sum.flags |= NILFS_SS_SR;
405 return err;
406}
407
408/*
409 * Functions for making segment summary and payloads
410 */
411static int nilfs_segctor_segsum_block_required(
412 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
413 unsigned binfo_size)
414{
415 unsigned blocksize = sci->sc_super->s_blocksize;
416 /* Size of finfo and binfo is enough small against blocksize */
417
418 return ssp->offset + binfo_size +
419 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
420 blocksize;
421}
422
423static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
424 struct inode *inode)
425{
426 sci->sc_curseg->sb_sum.nfinfo++;
427 sci->sc_binfo_ptr = sci->sc_finfo_ptr;
428 nilfs_segctor_map_segsum_entry(
429 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
430
431 if (NILFS_I(inode)->i_root &&
432 !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
433 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
434 /* skip finfo */
435}
436
437static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
438 struct inode *inode)
439{
440 struct nilfs_finfo *finfo;
441 struct nilfs_inode_info *ii;
442 struct nilfs_segment_buffer *segbuf;
443 __u64 cno;
444
445 if (sci->sc_blk_cnt == 0)
446 return;
447
448 ii = NILFS_I(inode);
449
450 if (test_bit(NILFS_I_GCINODE, &ii->i_state))
451 cno = ii->i_cno;
452 else if (NILFS_ROOT_METADATA_FILE(inode->i_ino))
453 cno = 0;
454 else
455 cno = sci->sc_cno;
456
457 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
458 sizeof(*finfo));
459 finfo->fi_ino = cpu_to_le64(inode->i_ino);
460 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
461 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
462 finfo->fi_cno = cpu_to_le64(cno);
463
464 segbuf = sci->sc_curseg;
465 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
466 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
467 sci->sc_finfo_ptr = sci->sc_binfo_ptr;
468 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
469}
470
471static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
472 struct buffer_head *bh,
473 struct inode *inode,
474 unsigned binfo_size)
475{
476 struct nilfs_segment_buffer *segbuf;
477 int required, err = 0;
478
479 retry:
480 segbuf = sci->sc_curseg;
481 required = nilfs_segctor_segsum_block_required(
482 sci, &sci->sc_binfo_ptr, binfo_size);
483 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
484 nilfs_segctor_end_finfo(sci, inode);
485 err = nilfs_segctor_feed_segment(sci);
486 if (err)
487 return err;
488 goto retry;
489 }
490 if (unlikely(required)) {
491 err = nilfs_segbuf_extend_segsum(segbuf);
492 if (unlikely(err))
493 goto failed;
494 }
495 if (sci->sc_blk_cnt == 0)
496 nilfs_segctor_begin_finfo(sci, inode);
497
498 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
499 /* Substitution to vblocknr is delayed until update_blocknr() */
500 nilfs_segbuf_add_file_buffer(segbuf, bh);
501 sci->sc_blk_cnt++;
502 failed:
503 return err;
504}
505
506/*
507 * Callback functions that enumerate, mark, and collect dirty blocks
508 */
509static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
510 struct buffer_head *bh, struct inode *inode)
511{
512 int err;
513
514 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
515 if (err < 0)
516 return err;
517
518 err = nilfs_segctor_add_file_block(sci, bh, inode,
519 sizeof(struct nilfs_binfo_v));
520 if (!err)
521 sci->sc_datablk_cnt++;
522 return err;
523}
524
525static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
526 struct buffer_head *bh,
527 struct inode *inode)
528{
529 return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
530}
531
532static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
533 struct buffer_head *bh,
534 struct inode *inode)
535{
536 WARN_ON(!buffer_dirty(bh));
537 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
538}
539
540static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
541 struct nilfs_segsum_pointer *ssp,
542 union nilfs_binfo *binfo)
543{
544 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
545 sci, ssp, sizeof(*binfo_v));
546 *binfo_v = binfo->bi_v;
547}
548
549static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
550 struct nilfs_segsum_pointer *ssp,
551 union nilfs_binfo *binfo)
552{
553 __le64 *vblocknr = nilfs_segctor_map_segsum_entry(
554 sci, ssp, sizeof(*vblocknr));
555 *vblocknr = binfo->bi_v.bi_vblocknr;
556}
557
558static struct nilfs_sc_operations nilfs_sc_file_ops = {
559 .collect_data = nilfs_collect_file_data,
560 .collect_node = nilfs_collect_file_node,
561 .collect_bmap = nilfs_collect_file_bmap,
562 .write_data_binfo = nilfs_write_file_data_binfo,
563 .write_node_binfo = nilfs_write_file_node_binfo,
564};
565
566static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
567 struct buffer_head *bh, struct inode *inode)
568{
569 int err;
570
571 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
572 if (err < 0)
573 return err;
574
575 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
576 if (!err)
577 sci->sc_datablk_cnt++;
578 return err;
579}
580
581static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
582 struct buffer_head *bh, struct inode *inode)
583{
584 WARN_ON(!buffer_dirty(bh));
585 return nilfs_segctor_add_file_block(sci, bh, inode,
586 sizeof(struct nilfs_binfo_dat));
587}
588
589static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
590 struct nilfs_segsum_pointer *ssp,
591 union nilfs_binfo *binfo)
592{
593 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
594 sizeof(*blkoff));
595 *blkoff = binfo->bi_dat.bi_blkoff;
596}
597
598static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
599 struct nilfs_segsum_pointer *ssp,
600 union nilfs_binfo *binfo)
601{
602 struct nilfs_binfo_dat *binfo_dat =
603 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
604 *binfo_dat = binfo->bi_dat;
605}
606
607static struct nilfs_sc_operations nilfs_sc_dat_ops = {
608 .collect_data = nilfs_collect_dat_data,
609 .collect_node = nilfs_collect_file_node,
610 .collect_bmap = nilfs_collect_dat_bmap,
611 .write_data_binfo = nilfs_write_dat_data_binfo,
612 .write_node_binfo = nilfs_write_dat_node_binfo,
613};
614
615static struct nilfs_sc_operations nilfs_sc_dsync_ops = {
616 .collect_data = nilfs_collect_file_data,
617 .collect_node = NULL,
618 .collect_bmap = NULL,
619 .write_data_binfo = nilfs_write_file_data_binfo,
620 .write_node_binfo = NULL,
621};
622
623static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
624 struct list_head *listp,
625 size_t nlimit,
626 loff_t start, loff_t end)
627{
628 struct address_space *mapping = inode->i_mapping;
629 struct pagevec pvec;
630 pgoff_t index = 0, last = ULONG_MAX;
631 size_t ndirties = 0;
632 int i;
633
634 if (unlikely(start != 0 || end != LLONG_MAX)) {
635 /*
636 * A valid range is given for sync-ing data pages. The
637 * range is rounded to per-page; extra dirty buffers
638 * may be included if blocksize < pagesize.
639 */
640 index = start >> PAGE_SHIFT;
641 last = end >> PAGE_SHIFT;
642 }
643 pagevec_init(&pvec, 0);
644 repeat:
645 if (unlikely(index > last) ||
646 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
647 min_t(pgoff_t, last - index,
648 PAGEVEC_SIZE - 1) + 1))
649 return ndirties;
650
651 for (i = 0; i < pagevec_count(&pvec); i++) {
652 struct buffer_head *bh, *head;
653 struct page *page = pvec.pages[i];
654
655 if (unlikely(page->index > last))
656 break;
657
658 lock_page(page);
659 if (!page_has_buffers(page))
660 create_empty_buffers(page, 1 << inode->i_blkbits, 0);
661 unlock_page(page);
662
663 bh = head = page_buffers(page);
664 do {
665 if (!buffer_dirty(bh))
666 continue;
667 get_bh(bh);
668 list_add_tail(&bh->b_assoc_buffers, listp);
669 ndirties++;
670 if (unlikely(ndirties >= nlimit)) {
671 pagevec_release(&pvec);
672 cond_resched();
673 return ndirties;
674 }
675 } while (bh = bh->b_this_page, bh != head);
676 }
677 pagevec_release(&pvec);
678 cond_resched();
679 goto repeat;
680}
681
682static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
683 struct list_head *listp)
684{
685 struct nilfs_inode_info *ii = NILFS_I(inode);
686 struct address_space *mapping = &ii->i_btnode_cache;
687 struct pagevec pvec;
688 struct buffer_head *bh, *head;
689 unsigned int i;
690 pgoff_t index = 0;
691
692 pagevec_init(&pvec, 0);
693
694 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
695 PAGEVEC_SIZE)) {
696 for (i = 0; i < pagevec_count(&pvec); i++) {
697 bh = head = page_buffers(pvec.pages[i]);
698 do {
699 if (buffer_dirty(bh)) {
700 get_bh(bh);
701 list_add_tail(&bh->b_assoc_buffers,
702 listp);
703 }
704 bh = bh->b_this_page;
705 } while (bh != head);
706 }
707 pagevec_release(&pvec);
708 cond_resched();
709 }
710}
711
712static void nilfs_dispose_list(struct the_nilfs *nilfs,
713 struct list_head *head, int force)
714{
715 struct nilfs_inode_info *ii, *n;
716 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
717 unsigned nv = 0;
718
719 while (!list_empty(head)) {
720 spin_lock(&nilfs->ns_inode_lock);
721 list_for_each_entry_safe(ii, n, head, i_dirty) {
722 list_del_init(&ii->i_dirty);
723 if (force) {
724 if (unlikely(ii->i_bh)) {
725 brelse(ii->i_bh);
726 ii->i_bh = NULL;
727 }
728 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
729 set_bit(NILFS_I_QUEUED, &ii->i_state);
730 list_add_tail(&ii->i_dirty,
731 &nilfs->ns_dirty_files);
732 continue;
733 }
734 ivec[nv++] = ii;
735 if (nv == SC_N_INODEVEC)
736 break;
737 }
738 spin_unlock(&nilfs->ns_inode_lock);
739
740 for (pii = ivec; nv > 0; pii++, nv--)
741 iput(&(*pii)->vfs_inode);
742 }
743}
744
745static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
746 struct nilfs_root *root)
747{
748 int ret = 0;
749
750 if (nilfs_mdt_fetch_dirty(root->ifile))
751 ret++;
752 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
753 ret++;
754 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
755 ret++;
756 if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat))
757 ret++;
758 return ret;
759}
760
761static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
762{
763 return list_empty(&sci->sc_dirty_files) &&
764 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
765 sci->sc_nfreesegs == 0 &&
766 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
767}
768
769static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
770{
771 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
772 int ret = 0;
773
774 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
775 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
776
777 spin_lock(&nilfs->ns_inode_lock);
778 if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci))
779 ret++;
780
781 spin_unlock(&nilfs->ns_inode_lock);
782 return ret;
783}
784
785static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
786{
787 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
788
789 nilfs_mdt_clear_dirty(sci->sc_root->ifile);
790 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
791 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
792 nilfs_mdt_clear_dirty(nilfs->ns_dat);
793}
794
795static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
796{
797 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
798 struct buffer_head *bh_cp;
799 struct nilfs_checkpoint *raw_cp;
800 int err;
801
802 /* XXX: this interface will be changed */
803 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
804 &raw_cp, &bh_cp);
805 if (likely(!err)) {
806 /* The following code is duplicated with cpfile. But, it is
807 needed to collect the checkpoint even if it was not newly
808 created */
809 mark_buffer_dirty(bh_cp);
810 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
811 nilfs_cpfile_put_checkpoint(
812 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
813 } else
814 WARN_ON(err == -EINVAL || err == -ENOENT);
815
816 return err;
817}
818
819static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
820{
821 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
822 struct buffer_head *bh_cp;
823 struct nilfs_checkpoint *raw_cp;
824 int err;
825
826 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
827 &raw_cp, &bh_cp);
828 if (unlikely(err)) {
829 WARN_ON(err == -EINVAL || err == -ENOENT);
830 goto failed_ibh;
831 }
832 raw_cp->cp_snapshot_list.ssl_next = 0;
833 raw_cp->cp_snapshot_list.ssl_prev = 0;
834 raw_cp->cp_inodes_count =
835 cpu_to_le64(atomic_read(&sci->sc_root->inodes_count));
836 raw_cp->cp_blocks_count =
837 cpu_to_le64(atomic_read(&sci->sc_root->blocks_count));
838 raw_cp->cp_nblk_inc =
839 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
840 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
841 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
842
843 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
844 nilfs_checkpoint_clear_minor(raw_cp);
845 else
846 nilfs_checkpoint_set_minor(raw_cp);
847
848 nilfs_write_inode_common(sci->sc_root->ifile,
849 &raw_cp->cp_ifile_inode, 1);
850 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
851 return 0;
852
853 failed_ibh:
854 return err;
855}
856
857static void nilfs_fill_in_file_bmap(struct inode *ifile,
858 struct nilfs_inode_info *ii)
859
860{
861 struct buffer_head *ibh;
862 struct nilfs_inode *raw_inode;
863
864 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
865 ibh = ii->i_bh;
866 BUG_ON(!ibh);
867 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
868 ibh);
869 nilfs_bmap_write(ii->i_bmap, raw_inode);
870 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
871 }
872}
873
874static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
875{
876 struct nilfs_inode_info *ii;
877
878 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
879 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
880 set_bit(NILFS_I_COLLECTED, &ii->i_state);
881 }
882}
883
884static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
885 struct the_nilfs *nilfs)
886{
887 struct buffer_head *bh_sr;
888 struct nilfs_super_root *raw_sr;
889 unsigned isz, srsz;
890
891 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
892 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
893 isz = nilfs->ns_inode_size;
894 srsz = NILFS_SR_BYTES(isz);
895
896 raw_sr->sr_bytes = cpu_to_le16(srsz);
897 raw_sr->sr_nongc_ctime
898 = cpu_to_le64(nilfs_doing_gc() ?
899 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
900 raw_sr->sr_flags = 0;
901
902 nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr +
903 NILFS_SR_DAT_OFFSET(isz), 1);
904 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
905 NILFS_SR_CPFILE_OFFSET(isz), 1);
906 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
907 NILFS_SR_SUFILE_OFFSET(isz), 1);
908 memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz);
909}
910
911static void nilfs_redirty_inodes(struct list_head *head)
912{
913 struct nilfs_inode_info *ii;
914
915 list_for_each_entry(ii, head, i_dirty) {
916 if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
917 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
918 }
919}
920
921static void nilfs_drop_collected_inodes(struct list_head *head)
922{
923 struct nilfs_inode_info *ii;
924
925 list_for_each_entry(ii, head, i_dirty) {
926 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
927 continue;
928
929 clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
930 set_bit(NILFS_I_UPDATED, &ii->i_state);
931 }
932}
933
934static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
935 struct inode *inode,
936 struct list_head *listp,
937 int (*collect)(struct nilfs_sc_info *,
938 struct buffer_head *,
939 struct inode *))
940{
941 struct buffer_head *bh, *n;
942 int err = 0;
943
944 if (collect) {
945 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
946 list_del_init(&bh->b_assoc_buffers);
947 err = collect(sci, bh, inode);
948 brelse(bh);
949 if (unlikely(err))
950 goto dispose_buffers;
951 }
952 return 0;
953 }
954
955 dispose_buffers:
956 while (!list_empty(listp)) {
957 bh = list_first_entry(listp, struct buffer_head,
958 b_assoc_buffers);
959 list_del_init(&bh->b_assoc_buffers);
960 brelse(bh);
961 }
962 return err;
963}
964
965static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
966{
967 /* Remaining number of blocks within segment buffer */
968 return sci->sc_segbuf_nblocks -
969 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
970}
971
972static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
973 struct inode *inode,
974 struct nilfs_sc_operations *sc_ops)
975{
976 LIST_HEAD(data_buffers);
977 LIST_HEAD(node_buffers);
978 int err;
979
980 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
981 size_t n, rest = nilfs_segctor_buffer_rest(sci);
982
983 n = nilfs_lookup_dirty_data_buffers(
984 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
985 if (n > rest) {
986 err = nilfs_segctor_apply_buffers(
987 sci, inode, &data_buffers,
988 sc_ops->collect_data);
989 BUG_ON(!err); /* always receive -E2BIG or true error */
990 goto break_or_fail;
991 }
992 }
993 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
994
995 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
996 err = nilfs_segctor_apply_buffers(
997 sci, inode, &data_buffers, sc_ops->collect_data);
998 if (unlikely(err)) {
999 /* dispose node list */
1000 nilfs_segctor_apply_buffers(
1001 sci, inode, &node_buffers, NULL);
1002 goto break_or_fail;
1003 }
1004 sci->sc_stage.flags |= NILFS_CF_NODE;
1005 }
1006 /* Collect node */
1007 err = nilfs_segctor_apply_buffers(
1008 sci, inode, &node_buffers, sc_ops->collect_node);
1009 if (unlikely(err))
1010 goto break_or_fail;
1011
1012 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1013 err = nilfs_segctor_apply_buffers(
1014 sci, inode, &node_buffers, sc_ops->collect_bmap);
1015 if (unlikely(err))
1016 goto break_or_fail;
1017
1018 nilfs_segctor_end_finfo(sci, inode);
1019 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1020
1021 break_or_fail:
1022 return err;
1023}
1024
1025static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1026 struct inode *inode)
1027{
1028 LIST_HEAD(data_buffers);
1029 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1030 int err;
1031
1032 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1033 sci->sc_dsync_start,
1034 sci->sc_dsync_end);
1035
1036 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1037 nilfs_collect_file_data);
1038 if (!err) {
1039 nilfs_segctor_end_finfo(sci, inode);
1040 BUG_ON(n > rest);
1041 /* always receive -E2BIG or true error if n > rest */
1042 }
1043 return err;
1044}
1045
1046static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1047{
1048 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1049 struct list_head *head;
1050 struct nilfs_inode_info *ii;
1051 size_t ndone;
1052 int err = 0;
1053
1054 switch (sci->sc_stage.scnt) {
1055 case NILFS_ST_INIT:
1056 /* Pre-processes */
1057 sci->sc_stage.flags = 0;
1058
1059 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1060 sci->sc_nblk_inc = 0;
1061 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1062 if (mode == SC_LSEG_DSYNC) {
1063 sci->sc_stage.scnt = NILFS_ST_DSYNC;
1064 goto dsync_mode;
1065 }
1066 }
1067
1068 sci->sc_stage.dirty_file_ptr = NULL;
1069 sci->sc_stage.gc_inode_ptr = NULL;
1070 if (mode == SC_FLUSH_DAT) {
1071 sci->sc_stage.scnt = NILFS_ST_DAT;
1072 goto dat_stage;
1073 }
1074 sci->sc_stage.scnt++; /* Fall through */
1075 case NILFS_ST_GC:
1076 if (nilfs_doing_gc()) {
1077 head = &sci->sc_gc_inodes;
1078 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1079 head, i_dirty);
1080 list_for_each_entry_continue(ii, head, i_dirty) {
1081 err = nilfs_segctor_scan_file(
1082 sci, &ii->vfs_inode,
1083 &nilfs_sc_file_ops);
1084 if (unlikely(err)) {
1085 sci->sc_stage.gc_inode_ptr = list_entry(
1086 ii->i_dirty.prev,
1087 struct nilfs_inode_info,
1088 i_dirty);
1089 goto break_or_fail;
1090 }
1091 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1092 }
1093 sci->sc_stage.gc_inode_ptr = NULL;
1094 }
1095 sci->sc_stage.scnt++; /* Fall through */
1096 case NILFS_ST_FILE:
1097 head = &sci->sc_dirty_files;
1098 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1099 i_dirty);
1100 list_for_each_entry_continue(ii, head, i_dirty) {
1101 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1102
1103 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1104 &nilfs_sc_file_ops);
1105 if (unlikely(err)) {
1106 sci->sc_stage.dirty_file_ptr =
1107 list_entry(ii->i_dirty.prev,
1108 struct nilfs_inode_info,
1109 i_dirty);
1110 goto break_or_fail;
1111 }
1112 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1113 /* XXX: required ? */
1114 }
1115 sci->sc_stage.dirty_file_ptr = NULL;
1116 if (mode == SC_FLUSH_FILE) {
1117 sci->sc_stage.scnt = NILFS_ST_DONE;
1118 return 0;
1119 }
1120 sci->sc_stage.scnt++;
1121 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1122 /* Fall through */
1123 case NILFS_ST_IFILE:
1124 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile,
1125 &nilfs_sc_file_ops);
1126 if (unlikely(err))
1127 break;
1128 sci->sc_stage.scnt++;
1129 /* Creating a checkpoint */
1130 err = nilfs_segctor_create_checkpoint(sci);
1131 if (unlikely(err))
1132 break;
1133 /* Fall through */
1134 case NILFS_ST_CPFILE:
1135 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1136 &nilfs_sc_file_ops);
1137 if (unlikely(err))
1138 break;
1139 sci->sc_stage.scnt++; /* Fall through */
1140 case NILFS_ST_SUFILE:
1141 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1142 sci->sc_nfreesegs, &ndone);
1143 if (unlikely(err)) {
1144 nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1145 sci->sc_freesegs, ndone,
1146 NULL);
1147 break;
1148 }
1149 sci->sc_stage.flags |= NILFS_CF_SUFREED;
1150
1151 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1152 &nilfs_sc_file_ops);
1153 if (unlikely(err))
1154 break;
1155 sci->sc_stage.scnt++; /* Fall through */
1156 case NILFS_ST_DAT:
1157 dat_stage:
1158 err = nilfs_segctor_scan_file(sci, nilfs->ns_dat,
1159 &nilfs_sc_dat_ops);
1160 if (unlikely(err))
1161 break;
1162 if (mode == SC_FLUSH_DAT) {
1163 sci->sc_stage.scnt = NILFS_ST_DONE;
1164 return 0;
1165 }
1166 sci->sc_stage.scnt++; /* Fall through */
1167 case NILFS_ST_SR:
1168 if (mode == SC_LSEG_SR) {
1169 /* Appending a super root */
1170 err = nilfs_segctor_add_super_root(sci);
1171 if (unlikely(err))
1172 break;
1173 }
1174 /* End of a logical segment */
1175 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1176 sci->sc_stage.scnt = NILFS_ST_DONE;
1177 return 0;
1178 case NILFS_ST_DSYNC:
1179 dsync_mode:
1180 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1181 ii = sci->sc_dsync_inode;
1182 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1183 break;
1184
1185 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1186 if (unlikely(err))
1187 break;
1188 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1189 sci->sc_stage.scnt = NILFS_ST_DONE;
1190 return 0;
1191 case NILFS_ST_DONE:
1192 return 0;
1193 default:
1194 BUG();
1195 }
1196
1197 break_or_fail:
1198 return err;
1199}
1200
1201/**
1202 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1203 * @sci: nilfs_sc_info
1204 * @nilfs: nilfs object
1205 */
1206static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1207 struct the_nilfs *nilfs)
1208{
1209 struct nilfs_segment_buffer *segbuf, *prev;
1210 __u64 nextnum;
1211 int err, alloc = 0;
1212
1213 segbuf = nilfs_segbuf_new(sci->sc_super);
1214 if (unlikely(!segbuf))
1215 return -ENOMEM;
1216
1217 if (list_empty(&sci->sc_write_logs)) {
1218 nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1219 nilfs->ns_pseg_offset, nilfs);
1220 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1221 nilfs_shift_to_next_segment(nilfs);
1222 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1223 }
1224
1225 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1226 nextnum = nilfs->ns_nextnum;
1227
1228 if (nilfs->ns_segnum == nilfs->ns_nextnum)
1229 /* Start from the head of a new full segment */
1230 alloc++;
1231 } else {
1232 /* Continue logs */
1233 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1234 nilfs_segbuf_map_cont(segbuf, prev);
1235 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1236 nextnum = prev->sb_nextnum;
1237
1238 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1239 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1240 segbuf->sb_sum.seg_seq++;
1241 alloc++;
1242 }
1243 }
1244
1245 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1246 if (err)
1247 goto failed;
1248
1249 if (alloc) {
1250 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1251 if (err)
1252 goto failed;
1253 }
1254 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1255
1256 BUG_ON(!list_empty(&sci->sc_segbufs));
1257 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1258 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1259 return 0;
1260
1261 failed:
1262 nilfs_segbuf_free(segbuf);
1263 return err;
1264}
1265
1266static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1267 struct the_nilfs *nilfs, int nadd)
1268{
1269 struct nilfs_segment_buffer *segbuf, *prev;
1270 struct inode *sufile = nilfs->ns_sufile;
1271 __u64 nextnextnum;
1272 LIST_HEAD(list);
1273 int err, ret, i;
1274
1275 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1276 /*
1277 * Since the segment specified with nextnum might be allocated during
1278 * the previous construction, the buffer including its segusage may
1279 * not be dirty. The following call ensures that the buffer is dirty
1280 * and will pin the buffer on memory until the sufile is written.
1281 */
1282 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1283 if (unlikely(err))
1284 return err;
1285
1286 for (i = 0; i < nadd; i++) {
1287 /* extend segment info */
1288 err = -ENOMEM;
1289 segbuf = nilfs_segbuf_new(sci->sc_super);
1290 if (unlikely(!segbuf))
1291 goto failed;
1292
1293 /* map this buffer to region of segment on-disk */
1294 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1295 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1296
1297 /* allocate the next next full segment */
1298 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1299 if (unlikely(err))
1300 goto failed_segbuf;
1301
1302 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1303 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1304
1305 list_add_tail(&segbuf->sb_list, &list);
1306 prev = segbuf;
1307 }
1308 list_splice_tail(&list, &sci->sc_segbufs);
1309 return 0;
1310
1311 failed_segbuf:
1312 nilfs_segbuf_free(segbuf);
1313 failed:
1314 list_for_each_entry(segbuf, &list, sb_list) {
1315 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1316 WARN_ON(ret); /* never fails */
1317 }
1318 nilfs_destroy_logs(&list);
1319 return err;
1320}
1321
1322static void nilfs_free_incomplete_logs(struct list_head *logs,
1323 struct the_nilfs *nilfs)
1324{
1325 struct nilfs_segment_buffer *segbuf, *prev;
1326 struct inode *sufile = nilfs->ns_sufile;
1327 int ret;
1328
1329 segbuf = NILFS_FIRST_SEGBUF(logs);
1330 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1331 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1332 WARN_ON(ret); /* never fails */
1333 }
1334 if (atomic_read(&segbuf->sb_err)) {
1335 /* Case 1: The first segment failed */
1336 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1337 /* Case 1a: Partial segment appended into an existing
1338 segment */
1339 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1340 segbuf->sb_fseg_end);
1341 else /* Case 1b: New full segment */
1342 set_nilfs_discontinued(nilfs);
1343 }
1344
1345 prev = segbuf;
1346 list_for_each_entry_continue(segbuf, logs, sb_list) {
1347 if (prev->sb_nextnum != segbuf->sb_nextnum) {
1348 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1349 WARN_ON(ret); /* never fails */
1350 }
1351 if (atomic_read(&segbuf->sb_err) &&
1352 segbuf->sb_segnum != nilfs->ns_nextnum)
1353 /* Case 2: extended segment (!= next) failed */
1354 nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1355 prev = segbuf;
1356 }
1357}
1358
1359static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1360 struct inode *sufile)
1361{
1362 struct nilfs_segment_buffer *segbuf;
1363 unsigned long live_blocks;
1364 int ret;
1365
1366 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1367 live_blocks = segbuf->sb_sum.nblocks +
1368 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1369 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1370 live_blocks,
1371 sci->sc_seg_ctime);
1372 WARN_ON(ret); /* always succeed because the segusage is dirty */
1373 }
1374}
1375
1376static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1377{
1378 struct nilfs_segment_buffer *segbuf;
1379 int ret;
1380
1381 segbuf = NILFS_FIRST_SEGBUF(logs);
1382 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1383 segbuf->sb_pseg_start -
1384 segbuf->sb_fseg_start, 0);
1385 WARN_ON(ret); /* always succeed because the segusage is dirty */
1386
1387 list_for_each_entry_continue(segbuf, logs, sb_list) {
1388 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1389 0, 0);
1390 WARN_ON(ret); /* always succeed */
1391 }
1392}
1393
1394static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1395 struct nilfs_segment_buffer *last,
1396 struct inode *sufile)
1397{
1398 struct nilfs_segment_buffer *segbuf = last;
1399 int ret;
1400
1401 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1402 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1403 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1404 WARN_ON(ret);
1405 }
1406 nilfs_truncate_logs(&sci->sc_segbufs, last);
1407}
1408
1409
1410static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1411 struct the_nilfs *nilfs, int mode)
1412{
1413 struct nilfs_cstage prev_stage = sci->sc_stage;
1414 int err, nadd = 1;
1415
1416 /* Collection retry loop */
1417 for (;;) {
1418 sci->sc_nblk_this_inc = 0;
1419 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1420
1421 err = nilfs_segctor_reset_segment_buffer(sci);
1422 if (unlikely(err))
1423 goto failed;
1424
1425 err = nilfs_segctor_collect_blocks(sci, mode);
1426 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1427 if (!err)
1428 break;
1429
1430 if (unlikely(err != -E2BIG))
1431 goto failed;
1432
1433 /* The current segment is filled up */
1434 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
1435 break;
1436
1437 nilfs_clear_logs(&sci->sc_segbufs);
1438
1439 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1440 if (unlikely(err))
1441 return err;
1442
1443 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1444 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1445 sci->sc_freesegs,
1446 sci->sc_nfreesegs,
1447 NULL);
1448 WARN_ON(err); /* do not happen */
1449 }
1450 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1451 sci->sc_stage = prev_stage;
1452 }
1453 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1454 return 0;
1455
1456 failed:
1457 return err;
1458}
1459
1460static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1461 struct buffer_head *new_bh)
1462{
1463 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1464
1465 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1466 /* The caller must release old_bh */
1467}
1468
1469static int
1470nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1471 struct nilfs_segment_buffer *segbuf,
1472 int mode)
1473{
1474 struct inode *inode = NULL;
1475 sector_t blocknr;
1476 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1477 unsigned long nblocks = 0, ndatablk = 0;
1478 struct nilfs_sc_operations *sc_op = NULL;
1479 struct nilfs_segsum_pointer ssp;
1480 struct nilfs_finfo *finfo = NULL;
1481 union nilfs_binfo binfo;
1482 struct buffer_head *bh, *bh_org;
1483 ino_t ino = 0;
1484 int err = 0;
1485
1486 if (!nfinfo)
1487 goto out;
1488
1489 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1490 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1491 ssp.offset = sizeof(struct nilfs_segment_summary);
1492
1493 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1494 if (bh == segbuf->sb_super_root)
1495 break;
1496 if (!finfo) {
1497 finfo = nilfs_segctor_map_segsum_entry(
1498 sci, &ssp, sizeof(*finfo));
1499 ino = le64_to_cpu(finfo->fi_ino);
1500 nblocks = le32_to_cpu(finfo->fi_nblocks);
1501 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1502
1503 inode = bh->b_page->mapping->host;
1504
1505 if (mode == SC_LSEG_DSYNC)
1506 sc_op = &nilfs_sc_dsync_ops;
1507 else if (ino == NILFS_DAT_INO)
1508 sc_op = &nilfs_sc_dat_ops;
1509 else /* file blocks */
1510 sc_op = &nilfs_sc_file_ops;
1511 }
1512 bh_org = bh;
1513 get_bh(bh_org);
1514 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1515 &binfo);
1516 if (bh != bh_org)
1517 nilfs_list_replace_buffer(bh_org, bh);
1518 brelse(bh_org);
1519 if (unlikely(err))
1520 goto failed_bmap;
1521
1522 if (ndatablk > 0)
1523 sc_op->write_data_binfo(sci, &ssp, &binfo);
1524 else
1525 sc_op->write_node_binfo(sci, &ssp, &binfo);
1526
1527 blocknr++;
1528 if (--nblocks == 0) {
1529 finfo = NULL;
1530 if (--nfinfo == 0)
1531 break;
1532 } else if (ndatablk > 0)
1533 ndatablk--;
1534 }
1535 out:
1536 return 0;
1537
1538 failed_bmap:
1539 return err;
1540}
1541
1542static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1543{
1544 struct nilfs_segment_buffer *segbuf;
1545 int err;
1546
1547 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1548 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1549 if (unlikely(err))
1550 return err;
1551 nilfs_segbuf_fill_in_segsum(segbuf);
1552 }
1553 return 0;
1554}
1555
1556static void nilfs_begin_page_io(struct page *page)
1557{
1558 if (!page || PageWriteback(page))
1559 /* For split b-tree node pages, this function may be called
1560 twice. We ignore the 2nd or later calls by this check. */
1561 return;
1562
1563 lock_page(page);
1564 clear_page_dirty_for_io(page);
1565 set_page_writeback(page);
1566 unlock_page(page);
1567}
1568
1569static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
1570{
1571 struct nilfs_segment_buffer *segbuf;
1572 struct page *bd_page = NULL, *fs_page = NULL;
1573
1574 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1575 struct buffer_head *bh;
1576
1577 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1578 b_assoc_buffers) {
1579 if (bh->b_page != bd_page) {
1580 if (bd_page) {
1581 lock_page(bd_page);
1582 clear_page_dirty_for_io(bd_page);
1583 set_page_writeback(bd_page);
1584 unlock_page(bd_page);
1585 }
1586 bd_page = bh->b_page;
1587 }
1588 }
1589
1590 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1591 b_assoc_buffers) {
1592 if (bh == segbuf->sb_super_root) {
1593 if (bh->b_page != bd_page) {
1594 lock_page(bd_page);
1595 clear_page_dirty_for_io(bd_page);
1596 set_page_writeback(bd_page);
1597 unlock_page(bd_page);
1598 bd_page = bh->b_page;
1599 }
1600 break;
1601 }
1602 if (bh->b_page != fs_page) {
1603 nilfs_begin_page_io(fs_page);
1604 fs_page = bh->b_page;
1605 }
1606 }
1607 }
1608 if (bd_page) {
1609 lock_page(bd_page);
1610 clear_page_dirty_for_io(bd_page);
1611 set_page_writeback(bd_page);
1612 unlock_page(bd_page);
1613 }
1614 nilfs_begin_page_io(fs_page);
1615}
1616
1617static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1618 struct the_nilfs *nilfs)
1619{
1620 int ret;
1621
1622 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1623 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1624 return ret;
1625}
1626
1627static void nilfs_end_page_io(struct page *page, int err)
1628{
1629 if (!page)
1630 return;
1631
1632 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
1633 /*
1634 * For b-tree node pages, this function may be called twice
1635 * or more because they might be split in a segment.
1636 */
1637 if (PageDirty(page)) {
1638 /*
1639 * For pages holding split b-tree node buffers, dirty
1640 * flag on the buffers may be cleared discretely.
1641 * In that case, the page is once redirtied for
1642 * remaining buffers, and it must be cancelled if
1643 * all the buffers get cleaned later.
1644 */
1645 lock_page(page);
1646 if (nilfs_page_buffers_clean(page))
1647 __nilfs_clear_page_dirty(page);
1648 unlock_page(page);
1649 }
1650 return;
1651 }
1652
1653 if (!err) {
1654 if (!nilfs_page_buffers_clean(page))
1655 __set_page_dirty_nobuffers(page);
1656 ClearPageError(page);
1657 } else {
1658 __set_page_dirty_nobuffers(page);
1659 SetPageError(page);
1660 }
1661
1662 end_page_writeback(page);
1663}
1664
1665static void nilfs_abort_logs(struct list_head *logs, int err)
1666{
1667 struct nilfs_segment_buffer *segbuf;
1668 struct page *bd_page = NULL, *fs_page = NULL;
1669 struct buffer_head *bh;
1670
1671 if (list_empty(logs))
1672 return;
1673
1674 list_for_each_entry(segbuf, logs, sb_list) {
1675 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1676 b_assoc_buffers) {
1677 if (bh->b_page != bd_page) {
1678 if (bd_page)
1679 end_page_writeback(bd_page);
1680 bd_page = bh->b_page;
1681 }
1682 }
1683
1684 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1685 b_assoc_buffers) {
1686 if (bh == segbuf->sb_super_root) {
1687 if (bh->b_page != bd_page) {
1688 end_page_writeback(bd_page);
1689 bd_page = bh->b_page;
1690 }
1691 break;
1692 }
1693 if (bh->b_page != fs_page) {
1694 nilfs_end_page_io(fs_page, err);
1695 fs_page = bh->b_page;
1696 }
1697 }
1698 }
1699 if (bd_page)
1700 end_page_writeback(bd_page);
1701
1702 nilfs_end_page_io(fs_page, err);
1703}
1704
1705static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1706 struct the_nilfs *nilfs, int err)
1707{
1708 LIST_HEAD(logs);
1709 int ret;
1710
1711 list_splice_tail_init(&sci->sc_write_logs, &logs);
1712 ret = nilfs_wait_on_logs(&logs);
1713 nilfs_abort_logs(&logs, ret ? : err);
1714
1715 list_splice_tail_init(&sci->sc_segbufs, &logs);
1716 nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1717 nilfs_free_incomplete_logs(&logs, nilfs);
1718
1719 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1720 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1721 sci->sc_freesegs,
1722 sci->sc_nfreesegs,
1723 NULL);
1724 WARN_ON(ret); /* do not happen */
1725 }
1726
1727 nilfs_destroy_logs(&logs);
1728}
1729
1730static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1731 struct nilfs_segment_buffer *segbuf)
1732{
1733 nilfs->ns_segnum = segbuf->sb_segnum;
1734 nilfs->ns_nextnum = segbuf->sb_nextnum;
1735 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1736 + segbuf->sb_sum.nblocks;
1737 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1738 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1739}
1740
1741static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1742{
1743 struct nilfs_segment_buffer *segbuf;
1744 struct page *bd_page = NULL, *fs_page = NULL;
1745 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1746 int update_sr = false;
1747
1748 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1749 struct buffer_head *bh;
1750
1751 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1752 b_assoc_buffers) {
1753 set_buffer_uptodate(bh);
1754 clear_buffer_dirty(bh);
1755 if (bh->b_page != bd_page) {
1756 if (bd_page)
1757 end_page_writeback(bd_page);
1758 bd_page = bh->b_page;
1759 }
1760 }
1761 /*
1762 * We assume that the buffers which belong to the same page
1763 * continue over the buffer list.
1764 * Under this assumption, the last BHs of pages is
1765 * identifiable by the discontinuity of bh->b_page
1766 * (page != fs_page).
1767 *
1768 * For B-tree node blocks, however, this assumption is not
1769 * guaranteed. The cleanup code of B-tree node pages needs
1770 * special care.
1771 */
1772 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1773 b_assoc_buffers) {
1774 set_buffer_uptodate(bh);
1775 clear_buffer_dirty(bh);
1776 clear_buffer_delay(bh);
1777 clear_buffer_nilfs_volatile(bh);
1778 clear_buffer_nilfs_redirected(bh);
1779 if (bh == segbuf->sb_super_root) {
1780 if (bh->b_page != bd_page) {
1781 end_page_writeback(bd_page);
1782 bd_page = bh->b_page;
1783 }
1784 update_sr = true;
1785 break;
1786 }
1787 if (bh->b_page != fs_page) {
1788 nilfs_end_page_io(fs_page, 0);
1789 fs_page = bh->b_page;
1790 }
1791 }
1792
1793 if (!nilfs_segbuf_simplex(segbuf)) {
1794 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
1795 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1796 sci->sc_lseg_stime = jiffies;
1797 }
1798 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
1799 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1800 }
1801 }
1802 /*
1803 * Since pages may continue over multiple segment buffers,
1804 * end of the last page must be checked outside of the loop.
1805 */
1806 if (bd_page)
1807 end_page_writeback(bd_page);
1808
1809 nilfs_end_page_io(fs_page, 0);
1810
1811 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1812
1813 if (nilfs_doing_gc())
1814 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1815 else
1816 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1817
1818 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1819
1820 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1821 nilfs_set_next_segment(nilfs, segbuf);
1822
1823 if (update_sr) {
1824 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
1825 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
1826
1827 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
1828 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1829 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1830 nilfs_segctor_clear_metadata_dirty(sci);
1831 } else
1832 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1833}
1834
1835static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
1836{
1837 int ret;
1838
1839 ret = nilfs_wait_on_logs(&sci->sc_write_logs);
1840 if (!ret) {
1841 nilfs_segctor_complete_write(sci);
1842 nilfs_destroy_logs(&sci->sc_write_logs);
1843 }
1844 return ret;
1845}
1846
1847static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci,
1848 struct the_nilfs *nilfs)
1849{
1850 struct nilfs_inode_info *ii, *n;
1851 struct inode *ifile = sci->sc_root->ifile;
1852
1853 spin_lock(&nilfs->ns_inode_lock);
1854 retry:
1855 list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) {
1856 if (!ii->i_bh) {
1857 struct buffer_head *ibh;
1858 int err;
1859
1860 spin_unlock(&nilfs->ns_inode_lock);
1861 err = nilfs_ifile_get_inode_block(
1862 ifile, ii->vfs_inode.i_ino, &ibh);
1863 if (unlikely(err)) {
1864 nilfs_warning(sci->sc_super, __func__,
1865 "failed to get inode block.\n");
1866 return err;
1867 }
1868 mark_buffer_dirty(ibh);
1869 nilfs_mdt_mark_dirty(ifile);
1870 spin_lock(&nilfs->ns_inode_lock);
1871 if (likely(!ii->i_bh))
1872 ii->i_bh = ibh;
1873 else
1874 brelse(ibh);
1875 goto retry;
1876 }
1877
1878 clear_bit(NILFS_I_QUEUED, &ii->i_state);
1879 set_bit(NILFS_I_BUSY, &ii->i_state);
1880 list_move_tail(&ii->i_dirty, &sci->sc_dirty_files);
1881 }
1882 spin_unlock(&nilfs->ns_inode_lock);
1883
1884 return 0;
1885}
1886
1887static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
1888 struct the_nilfs *nilfs)
1889{
1890 struct nilfs_transaction_info *ti = current->journal_info;
1891 struct nilfs_inode_info *ii, *n;
1892
1893 spin_lock(&nilfs->ns_inode_lock);
1894 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
1895 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
1896 test_bit(NILFS_I_DIRTY, &ii->i_state))
1897 continue;
1898
1899 clear_bit(NILFS_I_BUSY, &ii->i_state);
1900 brelse(ii->i_bh);
1901 ii->i_bh = NULL;
1902 list_move_tail(&ii->i_dirty, &ti->ti_garbage);
1903 }
1904 spin_unlock(&nilfs->ns_inode_lock);
1905}
1906
1907/*
1908 * Main procedure of segment constructor
1909 */
1910static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
1911{
1912 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1913 int err;
1914
1915 sci->sc_stage.scnt = NILFS_ST_INIT;
1916 sci->sc_cno = nilfs->ns_cno;
1917
1918 err = nilfs_segctor_collect_dirty_files(sci, nilfs);
1919 if (unlikely(err))
1920 goto out;
1921
1922 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
1923 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1924
1925 if (nilfs_segctor_clean(sci))
1926 goto out;
1927
1928 do {
1929 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
1930
1931 err = nilfs_segctor_begin_construction(sci, nilfs);
1932 if (unlikely(err))
1933 goto out;
1934
1935 /* Update time stamp */
1936 sci->sc_seg_ctime = get_seconds();
1937
1938 err = nilfs_segctor_collect(sci, nilfs, mode);
1939 if (unlikely(err))
1940 goto failed;
1941
1942 /* Avoid empty segment */
1943 if (sci->sc_stage.scnt == NILFS_ST_DONE &&
1944 nilfs_segbuf_empty(sci->sc_curseg)) {
1945 nilfs_segctor_abort_construction(sci, nilfs, 1);
1946 goto out;
1947 }
1948
1949 err = nilfs_segctor_assign(sci, mode);
1950 if (unlikely(err))
1951 goto failed;
1952
1953 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
1954 nilfs_segctor_fill_in_file_bmap(sci);
1955
1956 if (mode == SC_LSEG_SR &&
1957 sci->sc_stage.scnt >= NILFS_ST_CPFILE) {
1958 err = nilfs_segctor_fill_in_checkpoint(sci);
1959 if (unlikely(err))
1960 goto failed_to_write;
1961
1962 nilfs_segctor_fill_in_super_root(sci, nilfs);
1963 }
1964 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
1965
1966 /* Write partial segments */
1967 nilfs_segctor_prepare_write(sci);
1968
1969 nilfs_add_checksums_on_logs(&sci->sc_segbufs,
1970 nilfs->ns_crc_seed);
1971
1972 err = nilfs_segctor_write(sci, nilfs);
1973 if (unlikely(err))
1974 goto failed_to_write;
1975
1976 if (sci->sc_stage.scnt == NILFS_ST_DONE ||
1977 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
1978 /*
1979 * At this point, we avoid double buffering
1980 * for blocksize < pagesize because page dirty
1981 * flag is turned off during write and dirty
1982 * buffers are not properly collected for
1983 * pages crossing over segments.
1984 */
1985 err = nilfs_segctor_wait(sci);
1986 if (err)
1987 goto failed_to_write;
1988 }
1989 } while (sci->sc_stage.scnt != NILFS_ST_DONE);
1990
1991 out:
1992 nilfs_segctor_drop_written_files(sci, nilfs);
1993 return err;
1994
1995 failed_to_write:
1996 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
1997 nilfs_redirty_inodes(&sci->sc_dirty_files);
1998
1999 failed:
2000 if (nilfs_doing_gc())
2001 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2002 nilfs_segctor_abort_construction(sci, nilfs, err);
2003 goto out;
2004}
2005
2006/**
2007 * nilfs_segctor_start_timer - set timer of background write
2008 * @sci: nilfs_sc_info
2009 *
2010 * If the timer has already been set, it ignores the new request.
2011 * This function MUST be called within a section locking the segment
2012 * semaphore.
2013 */
2014static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2015{
2016 spin_lock(&sci->sc_state_lock);
2017 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2018 sci->sc_timer.expires = jiffies + sci->sc_interval;
2019 add_timer(&sci->sc_timer);
2020 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2021 }
2022 spin_unlock(&sci->sc_state_lock);
2023}
2024
2025static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2026{
2027 spin_lock(&sci->sc_state_lock);
2028 if (!(sci->sc_flush_request & (1 << bn))) {
2029 unsigned long prev_req = sci->sc_flush_request;
2030
2031 sci->sc_flush_request |= (1 << bn);
2032 if (!prev_req)
2033 wake_up(&sci->sc_wait_daemon);
2034 }
2035 spin_unlock(&sci->sc_state_lock);
2036}
2037
2038/**
2039 * nilfs_flush_segment - trigger a segment construction for resource control
2040 * @sb: super block
2041 * @ino: inode number of the file to be flushed out.
2042 */
2043void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2044{
2045 struct the_nilfs *nilfs = sb->s_fs_info;
2046 struct nilfs_sc_info *sci = nilfs->ns_writer;
2047
2048 if (!sci || nilfs_doing_construction())
2049 return;
2050 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2051 /* assign bit 0 to data files */
2052}
2053
2054struct nilfs_segctor_wait_request {
2055 wait_queue_t wq;
2056 __u32 seq;
2057 int err;
2058 atomic_t done;
2059};
2060
2061static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2062{
2063 struct nilfs_segctor_wait_request wait_req;
2064 int err = 0;
2065
2066 spin_lock(&sci->sc_state_lock);
2067 init_wait(&wait_req.wq);
2068 wait_req.err = 0;
2069 atomic_set(&wait_req.done, 0);
2070 wait_req.seq = ++sci->sc_seq_request;
2071 spin_unlock(&sci->sc_state_lock);
2072
2073 init_waitqueue_entry(&wait_req.wq, current);
2074 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2075 set_current_state(TASK_INTERRUPTIBLE);
2076 wake_up(&sci->sc_wait_daemon);
2077
2078 for (;;) {
2079 if (atomic_read(&wait_req.done)) {
2080 err = wait_req.err;
2081 break;
2082 }
2083 if (!signal_pending(current)) {
2084 schedule();
2085 continue;
2086 }
2087 err = -ERESTARTSYS;
2088 break;
2089 }
2090 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2091 return err;
2092}
2093
2094static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2095{
2096 struct nilfs_segctor_wait_request *wrq, *n;
2097 unsigned long flags;
2098
2099 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2100 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2101 wq.task_list) {
2102 if (!atomic_read(&wrq->done) &&
2103 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2104 wrq->err = err;
2105 atomic_set(&wrq->done, 1);
2106 }
2107 if (atomic_read(&wrq->done)) {
2108 wrq->wq.func(&wrq->wq,
2109 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2110 0, NULL);
2111 }
2112 }
2113 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2114}
2115
2116/**
2117 * nilfs_construct_segment - construct a logical segment
2118 * @sb: super block
2119 *
2120 * Return Value: On success, 0 is retured. On errors, one of the following
2121 * negative error code is returned.
2122 *
2123 * %-EROFS - Read only filesystem.
2124 *
2125 * %-EIO - I/O error
2126 *
2127 * %-ENOSPC - No space left on device (only in a panic state).
2128 *
2129 * %-ERESTARTSYS - Interrupted.
2130 *
2131 * %-ENOMEM - Insufficient memory available.
2132 */
2133int nilfs_construct_segment(struct super_block *sb)
2134{
2135 struct the_nilfs *nilfs = sb->s_fs_info;
2136 struct nilfs_sc_info *sci = nilfs->ns_writer;
2137 struct nilfs_transaction_info *ti;
2138 int err;
2139
2140 if (!sci)
2141 return -EROFS;
2142
2143 /* A call inside transactions causes a deadlock. */
2144 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2145
2146 err = nilfs_segctor_sync(sci);
2147 return err;
2148}
2149
2150/**
2151 * nilfs_construct_dsync_segment - construct a data-only logical segment
2152 * @sb: super block
2153 * @inode: inode whose data blocks should be written out
2154 * @start: start byte offset
2155 * @end: end byte offset (inclusive)
2156 *
2157 * Return Value: On success, 0 is retured. On errors, one of the following
2158 * negative error code is returned.
2159 *
2160 * %-EROFS - Read only filesystem.
2161 *
2162 * %-EIO - I/O error
2163 *
2164 * %-ENOSPC - No space left on device (only in a panic state).
2165 *
2166 * %-ERESTARTSYS - Interrupted.
2167 *
2168 * %-ENOMEM - Insufficient memory available.
2169 */
2170int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2171 loff_t start, loff_t end)
2172{
2173 struct the_nilfs *nilfs = sb->s_fs_info;
2174 struct nilfs_sc_info *sci = nilfs->ns_writer;
2175 struct nilfs_inode_info *ii;
2176 struct nilfs_transaction_info ti;
2177 int err = 0;
2178
2179 if (!sci)
2180 return -EROFS;
2181
2182 nilfs_transaction_lock(sb, &ti, 0);
2183
2184 ii = NILFS_I(inode);
2185 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
2186 nilfs_test_opt(nilfs, STRICT_ORDER) ||
2187 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2188 nilfs_discontinued(nilfs)) {
2189 nilfs_transaction_unlock(sb);
2190 err = nilfs_segctor_sync(sci);
2191 return err;
2192 }
2193
2194 spin_lock(&nilfs->ns_inode_lock);
2195 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2196 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2197 spin_unlock(&nilfs->ns_inode_lock);
2198 nilfs_transaction_unlock(sb);
2199 return 0;
2200 }
2201 spin_unlock(&nilfs->ns_inode_lock);
2202 sci->sc_dsync_inode = ii;
2203 sci->sc_dsync_start = start;
2204 sci->sc_dsync_end = end;
2205
2206 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2207
2208 nilfs_transaction_unlock(sb);
2209 return err;
2210}
2211
2212#define FLUSH_FILE_BIT (0x1) /* data file only */
2213#define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2214
2215/**
2216 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2217 * @sci: segment constructor object
2218 */
2219static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2220{
2221 spin_lock(&sci->sc_state_lock);
2222 sci->sc_seq_accepted = sci->sc_seq_request;
2223 spin_unlock(&sci->sc_state_lock);
2224 del_timer_sync(&sci->sc_timer);
2225}
2226
2227/**
2228 * nilfs_segctor_notify - notify the result of request to caller threads
2229 * @sci: segment constructor object
2230 * @mode: mode of log forming
2231 * @err: error code to be notified
2232 */
2233static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2234{
2235 /* Clear requests (even when the construction failed) */
2236 spin_lock(&sci->sc_state_lock);
2237
2238 if (mode == SC_LSEG_SR) {
2239 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2240 sci->sc_seq_done = sci->sc_seq_accepted;
2241 nilfs_segctor_wakeup(sci, err);
2242 sci->sc_flush_request = 0;
2243 } else {
2244 if (mode == SC_FLUSH_FILE)
2245 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2246 else if (mode == SC_FLUSH_DAT)
2247 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2248
2249 /* re-enable timer if checkpoint creation was not done */
2250 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2251 time_before(jiffies, sci->sc_timer.expires))
2252 add_timer(&sci->sc_timer);
2253 }
2254 spin_unlock(&sci->sc_state_lock);
2255}
2256
2257/**
2258 * nilfs_segctor_construct - form logs and write them to disk
2259 * @sci: segment constructor object
2260 * @mode: mode of log forming
2261 */
2262static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2263{
2264 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2265 struct nilfs_super_block **sbp;
2266 int err = 0;
2267
2268 nilfs_segctor_accept(sci);
2269
2270 if (nilfs_discontinued(nilfs))
2271 mode = SC_LSEG_SR;
2272 if (!nilfs_segctor_confirm(sci))
2273 err = nilfs_segctor_do_construct(sci, mode);
2274
2275 if (likely(!err)) {
2276 if (mode != SC_FLUSH_DAT)
2277 atomic_set(&nilfs->ns_ndirtyblks, 0);
2278 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2279 nilfs_discontinued(nilfs)) {
2280 down_write(&nilfs->ns_sem);
2281 err = -EIO;
2282 sbp = nilfs_prepare_super(sci->sc_super,
2283 nilfs_sb_will_flip(nilfs));
2284 if (likely(sbp)) {
2285 nilfs_set_log_cursor(sbp[0], nilfs);
2286 err = nilfs_commit_super(sci->sc_super,
2287 NILFS_SB_COMMIT);
2288 }
2289 up_write(&nilfs->ns_sem);
2290 }
2291 }
2292
2293 nilfs_segctor_notify(sci, mode, err);
2294 return err;
2295}
2296
2297static void nilfs_construction_timeout(unsigned long data)
2298{
2299 struct task_struct *p = (struct task_struct *)data;
2300 wake_up_process(p);
2301}
2302
2303static void
2304nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2305{
2306 struct nilfs_inode_info *ii, *n;
2307
2308 list_for_each_entry_safe(ii, n, head, i_dirty) {
2309 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2310 continue;
2311 list_del_init(&ii->i_dirty);
2312 truncate_inode_pages(&ii->vfs_inode.i_data, 0);
2313 nilfs_btnode_cache_clear(&ii->i_btnode_cache);
2314 iput(&ii->vfs_inode);
2315 }
2316}
2317
2318int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2319 void **kbufs)
2320{
2321 struct the_nilfs *nilfs = sb->s_fs_info;
2322 struct nilfs_sc_info *sci = nilfs->ns_writer;
2323 struct nilfs_transaction_info ti;
2324 int err;
2325
2326 if (unlikely(!sci))
2327 return -EROFS;
2328
2329 nilfs_transaction_lock(sb, &ti, 1);
2330
2331 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2332 if (unlikely(err))
2333 goto out_unlock;
2334
2335 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2336 if (unlikely(err)) {
2337 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2338 goto out_unlock;
2339 }
2340
2341 sci->sc_freesegs = kbufs[4];
2342 sci->sc_nfreesegs = argv[4].v_nmembs;
2343 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2344
2345 for (;;) {
2346 err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2347 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2348
2349 if (likely(!err))
2350 break;
2351
2352 nilfs_warning(sb, __func__,
2353 "segment construction failed. (err=%d)", err);
2354 set_current_state(TASK_INTERRUPTIBLE);
2355 schedule_timeout(sci->sc_interval);
2356 }
2357 if (nilfs_test_opt(nilfs, DISCARD)) {
2358 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2359 sci->sc_nfreesegs);
2360 if (ret) {
2361 printk(KERN_WARNING
2362 "NILFS warning: error %d on discard request, "
2363 "turning discards off for the device\n", ret);
2364 nilfs_clear_opt(nilfs, DISCARD);
2365 }
2366 }
2367
2368 out_unlock:
2369 sci->sc_freesegs = NULL;
2370 sci->sc_nfreesegs = 0;
2371 nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2372 nilfs_transaction_unlock(sb);
2373 return err;
2374}
2375
2376static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2377{
2378 struct nilfs_transaction_info ti;
2379
2380 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2381 nilfs_segctor_construct(sci, mode);
2382
2383 /*
2384 * Unclosed segment should be retried. We do this using sc_timer.
2385 * Timeout of sc_timer will invoke complete construction which leads
2386 * to close the current logical segment.
2387 */
2388 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2389 nilfs_segctor_start_timer(sci);
2390
2391 nilfs_transaction_unlock(sci->sc_super);
2392}
2393
2394static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2395{
2396 int mode = 0;
2397 int err;
2398
2399 spin_lock(&sci->sc_state_lock);
2400 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2401 SC_FLUSH_DAT : SC_FLUSH_FILE;
2402 spin_unlock(&sci->sc_state_lock);
2403
2404 if (mode) {
2405 err = nilfs_segctor_do_construct(sci, mode);
2406
2407 spin_lock(&sci->sc_state_lock);
2408 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2409 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2410 spin_unlock(&sci->sc_state_lock);
2411 }
2412 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2413}
2414
2415static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2416{
2417 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2418 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2419 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2420 return SC_FLUSH_FILE;
2421 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2422 return SC_FLUSH_DAT;
2423 }
2424 return SC_LSEG_SR;
2425}
2426
2427/**
2428 * nilfs_segctor_thread - main loop of the segment constructor thread.
2429 * @arg: pointer to a struct nilfs_sc_info.
2430 *
2431 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2432 * to execute segment constructions.
2433 */
2434static int nilfs_segctor_thread(void *arg)
2435{
2436 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2437 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2438 int timeout = 0;
2439
2440 sci->sc_timer.data = (unsigned long)current;
2441 sci->sc_timer.function = nilfs_construction_timeout;
2442
2443 /* start sync. */
2444 sci->sc_task = current;
2445 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2446 printk(KERN_INFO
2447 "segctord starting. Construction interval = %lu seconds, "
2448 "CP frequency < %lu seconds\n",
2449 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2450
2451 spin_lock(&sci->sc_state_lock);
2452 loop:
2453 for (;;) {
2454 int mode;
2455
2456 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2457 goto end_thread;
2458
2459 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2460 mode = SC_LSEG_SR;
2461 else if (!sci->sc_flush_request)
2462 break;
2463 else
2464 mode = nilfs_segctor_flush_mode(sci);
2465
2466 spin_unlock(&sci->sc_state_lock);
2467 nilfs_segctor_thread_construct(sci, mode);
2468 spin_lock(&sci->sc_state_lock);
2469 timeout = 0;
2470 }
2471
2472
2473 if (freezing(current)) {
2474 spin_unlock(&sci->sc_state_lock);
2475 try_to_freeze();
2476 spin_lock(&sci->sc_state_lock);
2477 } else {
2478 DEFINE_WAIT(wait);
2479 int should_sleep = 1;
2480
2481 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2482 TASK_INTERRUPTIBLE);
2483
2484 if (sci->sc_seq_request != sci->sc_seq_done)
2485 should_sleep = 0;
2486 else if (sci->sc_flush_request)
2487 should_sleep = 0;
2488 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2489 should_sleep = time_before(jiffies,
2490 sci->sc_timer.expires);
2491
2492 if (should_sleep) {
2493 spin_unlock(&sci->sc_state_lock);
2494 schedule();
2495 spin_lock(&sci->sc_state_lock);
2496 }
2497 finish_wait(&sci->sc_wait_daemon, &wait);
2498 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2499 time_after_eq(jiffies, sci->sc_timer.expires));
2500
2501 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2502 set_nilfs_discontinued(nilfs);
2503 }
2504 goto loop;
2505
2506 end_thread:
2507 spin_unlock(&sci->sc_state_lock);
2508
2509 /* end sync. */
2510 sci->sc_task = NULL;
2511 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2512 return 0;
2513}
2514
2515static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2516{
2517 struct task_struct *t;
2518
2519 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2520 if (IS_ERR(t)) {
2521 int err = PTR_ERR(t);
2522
2523 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2524 err);
2525 return err;
2526 }
2527 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2528 return 0;
2529}
2530
2531static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2532 __acquires(&sci->sc_state_lock)
2533 __releases(&sci->sc_state_lock)
2534{
2535 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2536
2537 while (sci->sc_task) {
2538 wake_up(&sci->sc_wait_daemon);
2539 spin_unlock(&sci->sc_state_lock);
2540 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2541 spin_lock(&sci->sc_state_lock);
2542 }
2543}
2544
2545/*
2546 * Setup & clean-up functions
2547 */
2548static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
2549 struct nilfs_root *root)
2550{
2551 struct the_nilfs *nilfs = sb->s_fs_info;
2552 struct nilfs_sc_info *sci;
2553
2554 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2555 if (!sci)
2556 return NULL;
2557
2558 sci->sc_super = sb;
2559
2560 nilfs_get_root(root);
2561 sci->sc_root = root;
2562
2563 init_waitqueue_head(&sci->sc_wait_request);
2564 init_waitqueue_head(&sci->sc_wait_daemon);
2565 init_waitqueue_head(&sci->sc_wait_task);
2566 spin_lock_init(&sci->sc_state_lock);
2567 INIT_LIST_HEAD(&sci->sc_dirty_files);
2568 INIT_LIST_HEAD(&sci->sc_segbufs);
2569 INIT_LIST_HEAD(&sci->sc_write_logs);
2570 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2571 init_timer(&sci->sc_timer);
2572
2573 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2574 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2575 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2576
2577 if (nilfs->ns_interval)
2578 sci->sc_interval = HZ * nilfs->ns_interval;
2579 if (nilfs->ns_watermark)
2580 sci->sc_watermark = nilfs->ns_watermark;
2581 return sci;
2582}
2583
2584static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2585{
2586 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2587
2588 /* The segctord thread was stopped and its timer was removed.
2589 But some tasks remain. */
2590 do {
2591 struct nilfs_transaction_info ti;
2592
2593 nilfs_transaction_lock(sci->sc_super, &ti, 0);
2594 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2595 nilfs_transaction_unlock(sci->sc_super);
2596
2597 } while (ret && retrycount-- > 0);
2598}
2599
2600/**
2601 * nilfs_segctor_destroy - destroy the segment constructor.
2602 * @sci: nilfs_sc_info
2603 *
2604 * nilfs_segctor_destroy() kills the segctord thread and frees
2605 * the nilfs_sc_info struct.
2606 * Caller must hold the segment semaphore.
2607 */
2608static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2609{
2610 struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2611 int flag;
2612
2613 up_write(&nilfs->ns_segctor_sem);
2614
2615 spin_lock(&sci->sc_state_lock);
2616 nilfs_segctor_kill_thread(sci);
2617 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2618 || sci->sc_seq_request != sci->sc_seq_done);
2619 spin_unlock(&sci->sc_state_lock);
2620
2621 if (flag || !nilfs_segctor_confirm(sci))
2622 nilfs_segctor_write_out(sci);
2623
2624 if (!list_empty(&sci->sc_dirty_files)) {
2625 nilfs_warning(sci->sc_super, __func__,
2626 "dirty file(s) after the final construction\n");
2627 nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
2628 }
2629
2630 WARN_ON(!list_empty(&sci->sc_segbufs));
2631 WARN_ON(!list_empty(&sci->sc_write_logs));
2632
2633 nilfs_put_root(sci->sc_root);
2634
2635 down_write(&nilfs->ns_segctor_sem);
2636
2637 del_timer_sync(&sci->sc_timer);
2638 kfree(sci);
2639}
2640
2641/**
2642 * nilfs_attach_log_writer - attach log writer
2643 * @sb: super block instance
2644 * @root: root object of the current filesystem tree
2645 *
2646 * This allocates a log writer object, initializes it, and starts the
2647 * log writer.
2648 *
2649 * Return Value: On success, 0 is returned. On error, one of the following
2650 * negative error code is returned.
2651 *
2652 * %-ENOMEM - Insufficient memory available.
2653 */
2654int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
2655{
2656 struct the_nilfs *nilfs = sb->s_fs_info;
2657 int err;
2658
2659 if (nilfs->ns_writer) {
2660 /*
2661 * This happens if the filesystem was remounted
2662 * read/write after nilfs_error degenerated it into a
2663 * read-only mount.
2664 */
2665 nilfs_detach_log_writer(sb);
2666 }
2667
2668 nilfs->ns_writer = nilfs_segctor_new(sb, root);
2669 if (!nilfs->ns_writer)
2670 return -ENOMEM;
2671
2672 err = nilfs_segctor_start_thread(nilfs->ns_writer);
2673 if (err) {
2674 kfree(nilfs->ns_writer);
2675 nilfs->ns_writer = NULL;
2676 }
2677 return err;
2678}
2679
2680/**
2681 * nilfs_detach_log_writer - destroy log writer
2682 * @sb: super block instance
2683 *
2684 * This kills log writer daemon, frees the log writer object, and
2685 * destroys list of dirty files.
2686 */
2687void nilfs_detach_log_writer(struct super_block *sb)
2688{
2689 struct the_nilfs *nilfs = sb->s_fs_info;
2690 LIST_HEAD(garbage_list);
2691
2692 down_write(&nilfs->ns_segctor_sem);
2693 if (nilfs->ns_writer) {
2694 nilfs_segctor_destroy(nilfs->ns_writer);
2695 nilfs->ns_writer = NULL;
2696 }
2697
2698 /* Force to free the list of dirty files */
2699 spin_lock(&nilfs->ns_inode_lock);
2700 if (!list_empty(&nilfs->ns_dirty_files)) {
2701 list_splice_init(&nilfs->ns_dirty_files, &garbage_list);
2702 nilfs_warning(sb, __func__,
2703 "Hit dirty file after stopped log writer\n");
2704 }
2705 spin_unlock(&nilfs->ns_inode_lock);
2706 up_write(&nilfs->ns_segctor_sem);
2707
2708 nilfs_dispose_list(nilfs, &garbage_list, 1);
2709}