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agp: fix arbitrary kernel memory writes
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / nilfs2 / segment.c
blobddce17b31eb4f5610f7f91b5212c29e33b44836a
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 "segbuf.h"
43
44
45 /*
46 * Segment constructor
47 */
48 #define SC_N_INODEVEC 16 /* Size of locally allocated inode vector */
49
50 #define SC_MAX_SEGDELTA 64 /* Upper limit of the number of segments
51 appended in collection retry loop */
52
53 /* Construction mode */
54 enum {
55 SC_LSEG_SR = 1, /* Make a logical segment having a super root */
56 SC_LSEG_DSYNC, /* Flush data blocks of a given file and make
57 a logical segment without a super root */
58 SC_FLUSH_FILE, /* Flush data files, leads to segment writes without
59 creating a checkpoint */
60 SC_FLUSH_DAT, /* Flush DAT file. This also creates segments without
61 a checkpoint */
62 };
63
64 /* Stage numbers of dirty block collection */
65 enum {
66 NILFS_ST_INIT = 0,
67 NILFS_ST_GC, /* Collecting dirty blocks for GC */
68 NILFS_ST_FILE,
69 NILFS_ST_IFILE,
70 NILFS_ST_CPFILE,
71 NILFS_ST_SUFILE,
72 NILFS_ST_DAT,
73 NILFS_ST_SR, /* Super root */
74 NILFS_ST_DSYNC, /* Data sync blocks */
75 NILFS_ST_DONE,
76 };
77
78 /* State flags of collection */
79 #define NILFS_CF_NODE 0x0001 /* Collecting node blocks */
80 #define NILFS_CF_IFILE_STARTED 0x0002 /* IFILE stage has started */
81 #define NILFS_CF_SUFREED 0x0004 /* segment usages has been freed */
82 #define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED)
83
84 /* Operations depending on the construction mode and file type */
85 struct nilfs_sc_operations {
86 int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *,
87 struct inode *);
88 int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *,
89 struct inode *);
90 int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *,
91 struct inode *);
92 void (*write_data_binfo)(struct nilfs_sc_info *,
93 struct nilfs_segsum_pointer *,
94 union nilfs_binfo *);
95 void (*write_node_binfo)(struct nilfs_sc_info *,
96 struct nilfs_segsum_pointer *,
97 union nilfs_binfo *);
98 };
99
100 /*
101 * Other definitions
102 */
103 static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
104 static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
105 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
106 static void nilfs_dispose_list(struct nilfs_sb_info *, struct list_head *,
107 int);
108
109 #define nilfs_cnt32_gt(a, b) \
110 (typecheck(__u32, a) && typecheck(__u32, b) && \
111 ((__s32)(b) - (__s32)(a) < 0))
112 #define nilfs_cnt32_ge(a, b) \
113 (typecheck(__u32, a) && typecheck(__u32, b) && \
114 ((__s32)(a) - (__s32)(b) >= 0))
115 #define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a)
116 #define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a)
117
118 /*
119 * Transaction
120 */
121 static struct kmem_cache *nilfs_transaction_cachep;
122
123 /**
124 * nilfs_init_transaction_cache - create a cache for nilfs_transaction_info
125 *
126 * nilfs_init_transaction_cache() creates a slab cache for the struct
127 * nilfs_transaction_info.
128 *
129 * Return Value: On success, it returns 0. On error, one of the following
130 * negative error code is returned.
131 *
132 * %-ENOMEM - Insufficient memory available.
133 */
134 int nilfs_init_transaction_cache(void)
135 {
136 nilfs_transaction_cachep =
137 kmem_cache_create("nilfs2_transaction_cache",
138 sizeof(struct nilfs_transaction_info),
139 0, SLAB_RECLAIM_ACCOUNT, NULL);
140 return (nilfs_transaction_cachep == NULL) ? -ENOMEM : 0;
141 }
142
143 /**
144 * nilfs_detroy_transaction_cache - destroy the cache for transaction info
145 *
146 * nilfs_destroy_transaction_cache() frees the slab cache for the struct
147 * nilfs_transaction_info.
148 */
149 void nilfs_destroy_transaction_cache(void)
150 {
151 kmem_cache_destroy(nilfs_transaction_cachep);
152 }
153
154 static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
155 {
156 struct nilfs_transaction_info *cur_ti = current->journal_info;
157 void *save = NULL;
158
159 if (cur_ti) {
160 if (cur_ti->ti_magic == NILFS_TI_MAGIC)
161 return ++cur_ti->ti_count;
162 else {
163 /*
164 * If journal_info field is occupied by other FS,
165 * it is saved and will be restored on
166 * nilfs_transaction_commit().
167 */
168 printk(KERN_WARNING
169 "NILFS warning: journal info from a different "
170 "FS\n");
171 save = current->journal_info;
172 }
173 }
174 if (!ti) {
175 ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
176 if (!ti)
177 return -ENOMEM;
178 ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
179 } else {
180 ti->ti_flags = 0;
181 }
182 ti->ti_count = 0;
183 ti->ti_save = save;
184 ti->ti_magic = NILFS_TI_MAGIC;
185 current->journal_info = ti;
186 return 0;
187 }
188
189 /**
190 * nilfs_transaction_begin - start indivisible file operations.
191 * @sb: super block
192 * @ti: nilfs_transaction_info
193 * @vacancy_check: flags for vacancy rate checks
194 *
195 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
196 * the segment semaphore, to make a segment construction and write tasks
197 * exclusive. The function is used with nilfs_transaction_commit() in pairs.
198 * The region enclosed by these two functions can be nested. To avoid a
199 * deadlock, the semaphore is only acquired or released in the outermost call.
200 *
201 * This function allocates a nilfs_transaction_info struct to keep context
202 * information on it. It is initialized and hooked onto the current task in
203 * the outermost call. If a pre-allocated struct is given to @ti, it is used
204 * instead; othewise a new struct is assigned from a slab.
205 *
206 * When @vacancy_check flag is set, this function will check the amount of
207 * free space, and will wait for the GC to reclaim disk space if low capacity.
208 *
209 * Return Value: On success, 0 is returned. On error, one of the following
210 * negative error code is returned.
211 *
212 * %-ENOMEM - Insufficient memory available.
213 *
214 * %-ENOSPC - No space left on device
215 */
216 int nilfs_transaction_begin(struct super_block *sb,
217 struct nilfs_transaction_info *ti,
218 int vacancy_check)
219 {
220 struct nilfs_sb_info *sbi;
221 struct the_nilfs *nilfs;
222 int ret = nilfs_prepare_segment_lock(ti);
223
224 if (unlikely(ret < 0))
225 return ret;
226 if (ret > 0)
227 return 0;
228
229 sbi = NILFS_SB(sb);
230 nilfs = sbi->s_nilfs;
231 down_read(&nilfs->ns_segctor_sem);
232 if (vacancy_check && nilfs_near_disk_full(nilfs)) {
233 up_read(&nilfs->ns_segctor_sem);
234 ret = -ENOSPC;
235 goto failed;
236 }
237 return 0;
238
239 failed:
240 ti = current->journal_info;
241 current->journal_info = ti->ti_save;
242 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
243 kmem_cache_free(nilfs_transaction_cachep, ti);
244 return ret;
245 }
246
247 /**
248 * nilfs_transaction_commit - commit indivisible file operations.
249 * @sb: super block
250 *
251 * nilfs_transaction_commit() releases the read semaphore which is
252 * acquired by nilfs_transaction_begin(). This is only performed
253 * in outermost call of this function. If a commit flag is set,
254 * nilfs_transaction_commit() sets a timer to start the segment
255 * constructor. If a sync flag is set, it starts construction
256 * directly.
257 */
258 int nilfs_transaction_commit(struct super_block *sb)
259 {
260 struct nilfs_transaction_info *ti = current->journal_info;
261 struct nilfs_sb_info *sbi;
262 struct nilfs_sc_info *sci;
263 int err = 0;
264
265 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
266 ti->ti_flags |= NILFS_TI_COMMIT;
267 if (ti->ti_count > 0) {
268 ti->ti_count--;
269 return 0;
270 }
271 sbi = NILFS_SB(sb);
272 sci = NILFS_SC(sbi);
273 if (sci != NULL) {
274 if (ti->ti_flags & NILFS_TI_COMMIT)
275 nilfs_segctor_start_timer(sci);
276 if (atomic_read(&sbi->s_nilfs->ns_ndirtyblks) >
277 sci->sc_watermark)
278 nilfs_segctor_do_flush(sci, 0);
279 }
280 up_read(&sbi->s_nilfs->ns_segctor_sem);
281 current->journal_info = ti->ti_save;
282
283 if (ti->ti_flags & NILFS_TI_SYNC)
284 err = nilfs_construct_segment(sb);
285 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
286 kmem_cache_free(nilfs_transaction_cachep, ti);
287 return err;
288 }
289
290 void nilfs_transaction_abort(struct super_block *sb)
291 {
292 struct nilfs_transaction_info *ti = current->journal_info;
293
294 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
295 if (ti->ti_count > 0) {
296 ti->ti_count--;
297 return;
298 }
299 up_read(&NILFS_SB(sb)->s_nilfs->ns_segctor_sem);
300
301 current->journal_info = ti->ti_save;
302 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
303 kmem_cache_free(nilfs_transaction_cachep, ti);
304 }
305
306 void nilfs_relax_pressure_in_lock(struct super_block *sb)
307 {
308 struct nilfs_sb_info *sbi = NILFS_SB(sb);
309 struct nilfs_sc_info *sci = NILFS_SC(sbi);
310 struct the_nilfs *nilfs = sbi->s_nilfs;
311
312 if (!sci || !sci->sc_flush_request)
313 return;
314
315 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
316 up_read(&nilfs->ns_segctor_sem);
317
318 down_write(&nilfs->ns_segctor_sem);
319 if (sci->sc_flush_request &&
320 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
321 struct nilfs_transaction_info *ti = current->journal_info;
322
323 ti->ti_flags |= NILFS_TI_WRITER;
324 nilfs_segctor_do_immediate_flush(sci);
325 ti->ti_flags &= ~NILFS_TI_WRITER;
326 }
327 downgrade_write(&nilfs->ns_segctor_sem);
328 }
329
330 static void nilfs_transaction_lock(struct nilfs_sb_info *sbi,
331 struct nilfs_transaction_info *ti,
332 int gcflag)
333 {
334 struct nilfs_transaction_info *cur_ti = current->journal_info;
335
336 WARN_ON(cur_ti);
337 ti->ti_flags = NILFS_TI_WRITER;
338 ti->ti_count = 0;
339 ti->ti_save = cur_ti;
340 ti->ti_magic = NILFS_TI_MAGIC;
341 INIT_LIST_HEAD(&ti->ti_garbage);
342 current->journal_info = ti;
343
344 for (;;) {
345 down_write(&sbi->s_nilfs->ns_segctor_sem);
346 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &NILFS_SC(sbi)->sc_flags))
347 break;
348
349 nilfs_segctor_do_immediate_flush(NILFS_SC(sbi));
350
351 up_write(&sbi->s_nilfs->ns_segctor_sem);
352 yield();
353 }
354 if (gcflag)
355 ti->ti_flags |= NILFS_TI_GC;
356 }
357
358 static void nilfs_transaction_unlock(struct nilfs_sb_info *sbi)
359 {
360 struct nilfs_transaction_info *ti = current->journal_info;
361
362 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
363 BUG_ON(ti->ti_count > 0);
364
365 up_write(&sbi->s_nilfs->ns_segctor_sem);
366 current->journal_info = ti->ti_save;
367 if (!list_empty(&ti->ti_garbage))
368 nilfs_dispose_list(sbi, &ti->ti_garbage, 0);
369 }
370
371 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
372 struct nilfs_segsum_pointer *ssp,
373 unsigned bytes)
374 {
375 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
376 unsigned blocksize = sci->sc_super->s_blocksize;
377 void *p;
378
379 if (unlikely(ssp->offset + bytes > blocksize)) {
380 ssp->offset = 0;
381 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
382 &segbuf->sb_segsum_buffers));
383 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
384 }
385 p = ssp->bh->b_data + ssp->offset;
386 ssp->offset += bytes;
387 return p;
388 }
389
390 /**
391 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
392 * @sci: nilfs_sc_info
393 */
394 static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
395 {
396 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
397 struct buffer_head *sumbh;
398 unsigned sumbytes;
399 unsigned flags = 0;
400 int err;
401
402 if (nilfs_doing_gc())
403 flags = NILFS_SS_GC;
404 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime);
405 if (unlikely(err))
406 return err;
407
408 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
409 sumbytes = segbuf->sb_sum.sumbytes;
410 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
411 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
412 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
413 return 0;
414 }
415
416 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
417 {
418 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
419 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
420 return -E2BIG; /* The current segment is filled up
421 (internal code) */
422 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
423 return nilfs_segctor_reset_segment_buffer(sci);
424 }
425
426 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
427 {
428 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
429 int err;
430
431 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
432 err = nilfs_segctor_feed_segment(sci);
433 if (err)
434 return err;
435 segbuf = sci->sc_curseg;
436 }
437 err = nilfs_segbuf_extend_payload(segbuf, &sci->sc_super_root);
438 if (likely(!err))
439 segbuf->sb_sum.flags |= NILFS_SS_SR;
440 return err;
441 }
442
443 /*
444 * Functions for making segment summary and payloads
445 */
446 static int nilfs_segctor_segsum_block_required(
447 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
448 unsigned binfo_size)
449 {
450 unsigned blocksize = sci->sc_super->s_blocksize;
451 /* Size of finfo and binfo is enough small against blocksize */
452
453 return ssp->offset + binfo_size +
454 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
455 blocksize;
456 }
457
458 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
459 struct inode *inode)
460 {
461 sci->sc_curseg->sb_sum.nfinfo++;
462 sci->sc_binfo_ptr = sci->sc_finfo_ptr;
463 nilfs_segctor_map_segsum_entry(
464 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
465
466 if (inode->i_sb && !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
467 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
468 /* skip finfo */
469 }
470
471 static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
472 struct inode *inode)
473 {
474 struct nilfs_finfo *finfo;
475 struct nilfs_inode_info *ii;
476 struct nilfs_segment_buffer *segbuf;
477
478 if (sci->sc_blk_cnt == 0)
479 return;
480
481 ii = NILFS_I(inode);
482 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
483 sizeof(*finfo));
484 finfo->fi_ino = cpu_to_le64(inode->i_ino);
485 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
486 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
487 finfo->fi_cno = cpu_to_le64(ii->i_cno);
488
489 segbuf = sci->sc_curseg;
490 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
491 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
492 sci->sc_finfo_ptr = sci->sc_binfo_ptr;
493 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
494 }
495
496 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
497 struct buffer_head *bh,
498 struct inode *inode,
499 unsigned binfo_size)
500 {
501 struct nilfs_segment_buffer *segbuf;
502 int required, err = 0;
503
504 retry:
505 segbuf = sci->sc_curseg;
506 required = nilfs_segctor_segsum_block_required(
507 sci, &sci->sc_binfo_ptr, binfo_size);
508 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
509 nilfs_segctor_end_finfo(sci, inode);
510 err = nilfs_segctor_feed_segment(sci);
511 if (err)
512 return err;
513 goto retry;
514 }
515 if (unlikely(required)) {
516 err = nilfs_segbuf_extend_segsum(segbuf);
517 if (unlikely(err))
518 goto failed;
519 }
520 if (sci->sc_blk_cnt == 0)
521 nilfs_segctor_begin_finfo(sci, inode);
522
523 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
524 /* Substitution to vblocknr is delayed until update_blocknr() */
525 nilfs_segbuf_add_file_buffer(segbuf, bh);
526 sci->sc_blk_cnt++;
527 failed:
528 return err;
529 }
530
531 static int nilfs_handle_bmap_error(int err, const char *fname,
532 struct inode *inode, struct super_block *sb)
533 {
534 if (err == -EINVAL) {
535 nilfs_error(sb, fname, "broken bmap (inode=%lu)\n",
536 inode->i_ino);
537 err = -EIO;
538 }
539 return err;
540 }
541
542 /*
543 * Callback functions that enumerate, mark, and collect dirty blocks
544 */
545 static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
546 struct buffer_head *bh, struct inode *inode)
547 {
548 int err;
549
550 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
551 if (unlikely(err < 0))
552 return nilfs_handle_bmap_error(err, __func__, inode,
553 sci->sc_super);
554
555 err = nilfs_segctor_add_file_block(sci, bh, inode,
556 sizeof(struct nilfs_binfo_v));
557 if (!err)
558 sci->sc_datablk_cnt++;
559 return err;
560 }
561
562 static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
563 struct buffer_head *bh,
564 struct inode *inode)
565 {
566 int err;
567
568 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
569 if (unlikely(err < 0))
570 return nilfs_handle_bmap_error(err, __func__, inode,
571 sci->sc_super);
572 return 0;
573 }
574
575 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
576 struct buffer_head *bh,
577 struct inode *inode)
578 {
579 WARN_ON(!buffer_dirty(bh));
580 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
581 }
582
583 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
584 struct nilfs_segsum_pointer *ssp,
585 union nilfs_binfo *binfo)
586 {
587 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
588 sci, ssp, sizeof(*binfo_v));
589 *binfo_v = binfo->bi_v;
590 }
591
592 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
593 struct nilfs_segsum_pointer *ssp,
594 union nilfs_binfo *binfo)
595 {
596 __le64 *vblocknr = nilfs_segctor_map_segsum_entry(
597 sci, ssp, sizeof(*vblocknr));
598 *vblocknr = binfo->bi_v.bi_vblocknr;
599 }
600
601 struct nilfs_sc_operations nilfs_sc_file_ops = {
602 .collect_data = nilfs_collect_file_data,
603 .collect_node = nilfs_collect_file_node,
604 .collect_bmap = nilfs_collect_file_bmap,
605 .write_data_binfo = nilfs_write_file_data_binfo,
606 .write_node_binfo = nilfs_write_file_node_binfo,
607 };
608
609 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
610 struct buffer_head *bh, struct inode *inode)
611 {
612 int err;
613
614 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
615 if (unlikely(err < 0))
616 return nilfs_handle_bmap_error(err, __func__, inode,
617 sci->sc_super);
618
619 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
620 if (!err)
621 sci->sc_datablk_cnt++;
622 return err;
623 }
624
625 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
626 struct buffer_head *bh, struct inode *inode)
627 {
628 WARN_ON(!buffer_dirty(bh));
629 return nilfs_segctor_add_file_block(sci, bh, inode,
630 sizeof(struct nilfs_binfo_dat));
631 }
632
633 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
634 struct nilfs_segsum_pointer *ssp,
635 union nilfs_binfo *binfo)
636 {
637 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
638 sizeof(*blkoff));
639 *blkoff = binfo->bi_dat.bi_blkoff;
640 }
641
642 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
643 struct nilfs_segsum_pointer *ssp,
644 union nilfs_binfo *binfo)
645 {
646 struct nilfs_binfo_dat *binfo_dat =
647 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
648 *binfo_dat = binfo->bi_dat;
649 }
650
651 struct nilfs_sc_operations nilfs_sc_dat_ops = {
652 .collect_data = nilfs_collect_dat_data,
653 .collect_node = nilfs_collect_file_node,
654 .collect_bmap = nilfs_collect_dat_bmap,
655 .write_data_binfo = nilfs_write_dat_data_binfo,
656 .write_node_binfo = nilfs_write_dat_node_binfo,
657 };
658
659 struct nilfs_sc_operations nilfs_sc_dsync_ops = {
660 .collect_data = nilfs_collect_file_data,
661 .collect_node = NULL,
662 .collect_bmap = NULL,
663 .write_data_binfo = nilfs_write_file_data_binfo,
664 .write_node_binfo = NULL,
665 };
666
667 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
668 struct list_head *listp,
669 size_t nlimit,
670 loff_t start, loff_t end)
671 {
672 struct address_space *mapping = inode->i_mapping;
673 struct pagevec pvec;
674 pgoff_t index = 0, last = ULONG_MAX;
675 size_t ndirties = 0;
676 int i;
677
678 if (unlikely(start != 0 || end != LLONG_MAX)) {
679 /*
680 * A valid range is given for sync-ing data pages. The
681 * range is rounded to per-page; extra dirty buffers
682 * may be included if blocksize < pagesize.
683 */
684 index = start >> PAGE_SHIFT;
685 last = end >> PAGE_SHIFT;
686 }
687 pagevec_init(&pvec, 0);
688 repeat:
689 if (unlikely(index > last) ||
690 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
691 min_t(pgoff_t, last - index,
692 PAGEVEC_SIZE - 1) + 1))
693 return ndirties;
694
695 for (i = 0; i < pagevec_count(&pvec); i++) {
696 struct buffer_head *bh, *head;
697 struct page *page = pvec.pages[i];
698
699 if (unlikely(page->index > last))
700 break;
701
702 if (mapping->host) {
703 lock_page(page);
704 if (!page_has_buffers(page))
705 create_empty_buffers(page,
706 1 << inode->i_blkbits, 0);
707 unlock_page(page);
708 }
709
710 bh = head = page_buffers(page);
711 do {
712 if (!buffer_dirty(bh))
713 continue;
714 get_bh(bh);
715 list_add_tail(&bh->b_assoc_buffers, listp);
716 ndirties++;
717 if (unlikely(ndirties >= nlimit)) {
718 pagevec_release(&pvec);
719 cond_resched();
720 return ndirties;
721 }
722 } while (bh = bh->b_this_page, bh != head);
723 }
724 pagevec_release(&pvec);
725 cond_resched();
726 goto repeat;
727 }
728
729 static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
730 struct list_head *listp)
731 {
732 struct nilfs_inode_info *ii = NILFS_I(inode);
733 struct address_space *mapping = &ii->i_btnode_cache;
734 struct pagevec pvec;
735 struct buffer_head *bh, *head;
736 unsigned int i;
737 pgoff_t index = 0;
738
739 pagevec_init(&pvec, 0);
740
741 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
742 PAGEVEC_SIZE)) {
743 for (i = 0; i < pagevec_count(&pvec); i++) {
744 bh = head = page_buffers(pvec.pages[i]);
745 do {
746 if (buffer_dirty(bh)) {
747 get_bh(bh);
748 list_add_tail(&bh->b_assoc_buffers,
749 listp);
750 }
751 bh = bh->b_this_page;
752 } while (bh != head);
753 }
754 pagevec_release(&pvec);
755 cond_resched();
756 }
757 }
758
759 static void nilfs_dispose_list(struct nilfs_sb_info *sbi,
760 struct list_head *head, int force)
761 {
762 struct nilfs_inode_info *ii, *n;
763 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
764 unsigned nv = 0;
765
766 while (!list_empty(head)) {
767 spin_lock(&sbi->s_inode_lock);
768 list_for_each_entry_safe(ii, n, head, i_dirty) {
769 list_del_init(&ii->i_dirty);
770 if (force) {
771 if (unlikely(ii->i_bh)) {
772 brelse(ii->i_bh);
773 ii->i_bh = NULL;
774 }
775 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
776 set_bit(NILFS_I_QUEUED, &ii->i_state);
777 list_add_tail(&ii->i_dirty,
778 &sbi->s_dirty_files);
779 continue;
780 }
781 ivec[nv++] = ii;
782 if (nv == SC_N_INODEVEC)
783 break;
784 }
785 spin_unlock(&sbi->s_inode_lock);
786
787 for (pii = ivec; nv > 0; pii++, nv--)
788 iput(&(*pii)->vfs_inode);
789 }
790 }
791
792 static int nilfs_test_metadata_dirty(struct nilfs_sb_info *sbi)
793 {
794 struct the_nilfs *nilfs = sbi->s_nilfs;
795 int ret = 0;
796
797 if (nilfs_mdt_fetch_dirty(sbi->s_ifile))
798 ret++;
799 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
800 ret++;
801 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
802 ret++;
803 if (ret || nilfs_doing_gc())
804 if (nilfs_mdt_fetch_dirty(nilfs_dat_inode(nilfs)))
805 ret++;
806 return ret;
807 }
808
809 static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
810 {
811 return list_empty(&sci->sc_dirty_files) &&
812 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
813 sci->sc_nfreesegs == 0 &&
814 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
815 }
816
817 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
818 {
819 struct nilfs_sb_info *sbi = sci->sc_sbi;
820 int ret = 0;
821
822 if (nilfs_test_metadata_dirty(sbi))
823 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
824
825 spin_lock(&sbi->s_inode_lock);
826 if (list_empty(&sbi->s_dirty_files) && nilfs_segctor_clean(sci))
827 ret++;
828
829 spin_unlock(&sbi->s_inode_lock);
830 return ret;
831 }
832
833 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
834 {
835 struct nilfs_sb_info *sbi = sci->sc_sbi;
836 struct the_nilfs *nilfs = sbi->s_nilfs;
837
838 nilfs_mdt_clear_dirty(sbi->s_ifile);
839 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
840 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
841 nilfs_mdt_clear_dirty(nilfs_dat_inode(nilfs));
842 }
843
844 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
845 {
846 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
847 struct buffer_head *bh_cp;
848 struct nilfs_checkpoint *raw_cp;
849 int err;
850
851 /* XXX: this interface will be changed */
852 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
853 &raw_cp, &bh_cp);
854 if (likely(!err)) {
855 /* The following code is duplicated with cpfile. But, it is
856 needed to collect the checkpoint even if it was not newly
857 created */
858 nilfs_mdt_mark_buffer_dirty(bh_cp);
859 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
860 nilfs_cpfile_put_checkpoint(
861 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
862 } else
863 WARN_ON(err == -EINVAL || err == -ENOENT);
864
865 return err;
866 }
867
868 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
869 {
870 struct nilfs_sb_info *sbi = sci->sc_sbi;
871 struct the_nilfs *nilfs = sbi->s_nilfs;
872 struct buffer_head *bh_cp;
873 struct nilfs_checkpoint *raw_cp;
874 int err;
875
876 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
877 &raw_cp, &bh_cp);
878 if (unlikely(err)) {
879 WARN_ON(err == -EINVAL || err == -ENOENT);
880 goto failed_ibh;
881 }
882 raw_cp->cp_snapshot_list.ssl_next = 0;
883 raw_cp->cp_snapshot_list.ssl_prev = 0;
884 raw_cp->cp_inodes_count =
885 cpu_to_le64(atomic_read(&sbi->s_inodes_count));
886 raw_cp->cp_blocks_count =
887 cpu_to_le64(atomic_read(&sbi->s_blocks_count));
888 raw_cp->cp_nblk_inc =
889 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
890 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
891 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
892
893 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
894 nilfs_checkpoint_clear_minor(raw_cp);
895 else
896 nilfs_checkpoint_set_minor(raw_cp);
897
898 nilfs_write_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode, 1);
899 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
900 return 0;
901
902 failed_ibh:
903 return err;
904 }
905
906 static void nilfs_fill_in_file_bmap(struct inode *ifile,
907 struct nilfs_inode_info *ii)
908
909 {
910 struct buffer_head *ibh;
911 struct nilfs_inode *raw_inode;
912
913 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
914 ibh = ii->i_bh;
915 BUG_ON(!ibh);
916 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
917 ibh);
918 nilfs_bmap_write(ii->i_bmap, raw_inode);
919 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
920 }
921 }
922
923 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci,
924 struct inode *ifile)
925 {
926 struct nilfs_inode_info *ii;
927
928 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
929 nilfs_fill_in_file_bmap(ifile, ii);
930 set_bit(NILFS_I_COLLECTED, &ii->i_state);
931 }
932 }
933
934 /*
935 * CRC calculation routines
936 */
937 static void nilfs_fill_in_super_root_crc(struct buffer_head *bh_sr, u32 seed)
938 {
939 struct nilfs_super_root *raw_sr =
940 (struct nilfs_super_root *)bh_sr->b_data;
941 u32 crc;
942
943 crc = crc32_le(seed,
944 (unsigned char *)raw_sr + sizeof(raw_sr->sr_sum),
945 NILFS_SR_BYTES - sizeof(raw_sr->sr_sum));
946 raw_sr->sr_sum = cpu_to_le32(crc);
947 }
948
949 static void nilfs_segctor_fill_in_checksums(struct nilfs_sc_info *sci,
950 u32 seed)
951 {
952 struct nilfs_segment_buffer *segbuf;
953
954 if (sci->sc_super_root)
955 nilfs_fill_in_super_root_crc(sci->sc_super_root, seed);
956
957 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
958 nilfs_segbuf_fill_in_segsum_crc(segbuf, seed);
959 nilfs_segbuf_fill_in_data_crc(segbuf, seed);
960 }
961 }
962
963 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
964 struct the_nilfs *nilfs)
965 {
966 struct buffer_head *bh_sr = sci->sc_super_root;
967 struct nilfs_super_root *raw_sr =
968 (struct nilfs_super_root *)bh_sr->b_data;
969 unsigned isz = nilfs->ns_inode_size;
970
971 raw_sr->sr_bytes = cpu_to_le16(NILFS_SR_BYTES);
972 raw_sr->sr_nongc_ctime
973 = cpu_to_le64(nilfs_doing_gc() ?
974 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
975 raw_sr->sr_flags = 0;
976
977 nilfs_write_inode_common(nilfs_dat_inode(nilfs), (void *)raw_sr +
978 NILFS_SR_DAT_OFFSET(isz), 1);
979 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
980 NILFS_SR_CPFILE_OFFSET(isz), 1);
981 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
982 NILFS_SR_SUFILE_OFFSET(isz), 1);
983 }
984
985 static void nilfs_redirty_inodes(struct list_head *head)
986 {
987 struct nilfs_inode_info *ii;
988
989 list_for_each_entry(ii, head, i_dirty) {
990 if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
991 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
992 }
993 }
994
995 static void nilfs_drop_collected_inodes(struct list_head *head)
996 {
997 struct nilfs_inode_info *ii;
998
999 list_for_each_entry(ii, head, i_dirty) {
1000 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
1001 continue;
1002
1003 clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
1004 set_bit(NILFS_I_UPDATED, &ii->i_state);
1005 }
1006 }
1007
1008 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
1009 struct inode *inode,
1010 struct list_head *listp,
1011 int (*collect)(struct nilfs_sc_info *,
1012 struct buffer_head *,
1013 struct inode *))
1014 {
1015 struct buffer_head *bh, *n;
1016 int err = 0;
1017
1018 if (collect) {
1019 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
1020 list_del_init(&bh->b_assoc_buffers);
1021 err = collect(sci, bh, inode);
1022 brelse(bh);
1023 if (unlikely(err))
1024 goto dispose_buffers;
1025 }
1026 return 0;
1027 }
1028
1029 dispose_buffers:
1030 while (!list_empty(listp)) {
1031 bh = list_entry(listp->next, struct buffer_head,
1032 b_assoc_buffers);
1033 list_del_init(&bh->b_assoc_buffers);
1034 brelse(bh);
1035 }
1036 return err;
1037 }
1038
1039 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
1040 {
1041 /* Remaining number of blocks within segment buffer */
1042 return sci->sc_segbuf_nblocks -
1043 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
1044 }
1045
1046 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
1047 struct inode *inode,
1048 struct nilfs_sc_operations *sc_ops)
1049 {
1050 LIST_HEAD(data_buffers);
1051 LIST_HEAD(node_buffers);
1052 int err;
1053
1054 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1055 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1056
1057 n = nilfs_lookup_dirty_data_buffers(
1058 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
1059 if (n > rest) {
1060 err = nilfs_segctor_apply_buffers(
1061 sci, inode, &data_buffers,
1062 sc_ops->collect_data);
1063 BUG_ON(!err); /* always receive -E2BIG or true error */
1064 goto break_or_fail;
1065 }
1066 }
1067 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
1068
1069 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1070 err = nilfs_segctor_apply_buffers(
1071 sci, inode, &data_buffers, sc_ops->collect_data);
1072 if (unlikely(err)) {
1073 /* dispose node list */
1074 nilfs_segctor_apply_buffers(
1075 sci, inode, &node_buffers, NULL);
1076 goto break_or_fail;
1077 }
1078 sci->sc_stage.flags |= NILFS_CF_NODE;
1079 }
1080 /* Collect node */
1081 err = nilfs_segctor_apply_buffers(
1082 sci, inode, &node_buffers, sc_ops->collect_node);
1083 if (unlikely(err))
1084 goto break_or_fail;
1085
1086 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1087 err = nilfs_segctor_apply_buffers(
1088 sci, inode, &node_buffers, sc_ops->collect_bmap);
1089 if (unlikely(err))
1090 goto break_or_fail;
1091
1092 nilfs_segctor_end_finfo(sci, inode);
1093 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1094
1095 break_or_fail:
1096 return err;
1097 }
1098
1099 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1100 struct inode *inode)
1101 {
1102 LIST_HEAD(data_buffers);
1103 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1104 int err;
1105
1106 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1107 sci->sc_dsync_start,
1108 sci->sc_dsync_end);
1109
1110 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1111 nilfs_collect_file_data);
1112 if (!err) {
1113 nilfs_segctor_end_finfo(sci, inode);
1114 BUG_ON(n > rest);
1115 /* always receive -E2BIG or true error if n > rest */
1116 }
1117 return err;
1118 }
1119
1120 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1121 {
1122 struct nilfs_sb_info *sbi = sci->sc_sbi;
1123 struct the_nilfs *nilfs = sbi->s_nilfs;
1124 struct list_head *head;
1125 struct nilfs_inode_info *ii;
1126 size_t ndone;
1127 int err = 0;
1128
1129 switch (sci->sc_stage.scnt) {
1130 case NILFS_ST_INIT:
1131 /* Pre-processes */
1132 sci->sc_stage.flags = 0;
1133
1134 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1135 sci->sc_nblk_inc = 0;
1136 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1137 if (mode == SC_LSEG_DSYNC) {
1138 sci->sc_stage.scnt = NILFS_ST_DSYNC;
1139 goto dsync_mode;
1140 }
1141 }
1142
1143 sci->sc_stage.dirty_file_ptr = NULL;
1144 sci->sc_stage.gc_inode_ptr = NULL;
1145 if (mode == SC_FLUSH_DAT) {
1146 sci->sc_stage.scnt = NILFS_ST_DAT;
1147 goto dat_stage;
1148 }
1149 sci->sc_stage.scnt++; /* Fall through */
1150 case NILFS_ST_GC:
1151 if (nilfs_doing_gc()) {
1152 head = &sci->sc_gc_inodes;
1153 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1154 head, i_dirty);
1155 list_for_each_entry_continue(ii, head, i_dirty) {
1156 err = nilfs_segctor_scan_file(
1157 sci, &ii->vfs_inode,
1158 &nilfs_sc_file_ops);
1159 if (unlikely(err)) {
1160 sci->sc_stage.gc_inode_ptr = list_entry(
1161 ii->i_dirty.prev,
1162 struct nilfs_inode_info,
1163 i_dirty);
1164 goto break_or_fail;
1165 }
1166 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1167 }
1168 sci->sc_stage.gc_inode_ptr = NULL;
1169 }
1170 sci->sc_stage.scnt++; /* Fall through */
1171 case NILFS_ST_FILE:
1172 head = &sci->sc_dirty_files;
1173 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1174 i_dirty);
1175 list_for_each_entry_continue(ii, head, i_dirty) {
1176 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1177
1178 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1179 &nilfs_sc_file_ops);
1180 if (unlikely(err)) {
1181 sci->sc_stage.dirty_file_ptr =
1182 list_entry(ii->i_dirty.prev,
1183 struct nilfs_inode_info,
1184 i_dirty);
1185 goto break_or_fail;
1186 }
1187 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1188 /* XXX: required ? */
1189 }
1190 sci->sc_stage.dirty_file_ptr = NULL;
1191 if (mode == SC_FLUSH_FILE) {
1192 sci->sc_stage.scnt = NILFS_ST_DONE;
1193 return 0;
1194 }
1195 sci->sc_stage.scnt++;
1196 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1197 /* Fall through */
1198 case NILFS_ST_IFILE:
1199 err = nilfs_segctor_scan_file(sci, sbi->s_ifile,
1200 &nilfs_sc_file_ops);
1201 if (unlikely(err))
1202 break;
1203 sci->sc_stage.scnt++;
1204 /* Creating a checkpoint */
1205 err = nilfs_segctor_create_checkpoint(sci);
1206 if (unlikely(err))
1207 break;
1208 /* Fall through */
1209 case NILFS_ST_CPFILE:
1210 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1211 &nilfs_sc_file_ops);
1212 if (unlikely(err))
1213 break;
1214 sci->sc_stage.scnt++; /* Fall through */
1215 case NILFS_ST_SUFILE:
1216 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1217 sci->sc_nfreesegs, &ndone);
1218 if (unlikely(err)) {
1219 nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1220 sci->sc_freesegs, ndone,
1221 NULL);
1222 break;
1223 }
1224 sci->sc_stage.flags |= NILFS_CF_SUFREED;
1225
1226 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1227 &nilfs_sc_file_ops);
1228 if (unlikely(err))
1229 break;
1230 sci->sc_stage.scnt++; /* Fall through */
1231 case NILFS_ST_DAT:
1232 dat_stage:
1233 err = nilfs_segctor_scan_file(sci, nilfs_dat_inode(nilfs),
1234 &nilfs_sc_dat_ops);
1235 if (unlikely(err))
1236 break;
1237 if (mode == SC_FLUSH_DAT) {
1238 sci->sc_stage.scnt = NILFS_ST_DONE;
1239 return 0;
1240 }
1241 sci->sc_stage.scnt++; /* Fall through */
1242 case NILFS_ST_SR:
1243 if (mode == SC_LSEG_SR) {
1244 /* Appending a super root */
1245 err = nilfs_segctor_add_super_root(sci);
1246 if (unlikely(err))
1247 break;
1248 }
1249 /* End of a logical segment */
1250 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1251 sci->sc_stage.scnt = NILFS_ST_DONE;
1252 return 0;
1253 case NILFS_ST_DSYNC:
1254 dsync_mode:
1255 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1256 ii = sci->sc_dsync_inode;
1257 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1258 break;
1259
1260 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1261 if (unlikely(err))
1262 break;
1263 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1264 sci->sc_stage.scnt = NILFS_ST_DONE;
1265 return 0;
1266 case NILFS_ST_DONE:
1267 return 0;
1268 default:
1269 BUG();
1270 }
1271
1272 break_or_fail:
1273 return err;
1274 }
1275
1276 /**
1277 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1278 * @sci: nilfs_sc_info
1279 * @nilfs: nilfs object
1280 */
1281 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1282 struct the_nilfs *nilfs)
1283 {
1284 struct nilfs_segment_buffer *segbuf, *prev;
1285 __u64 nextnum;
1286 int err, alloc = 0;
1287
1288 segbuf = nilfs_segbuf_new(sci->sc_super);
1289 if (unlikely(!segbuf))
1290 return -ENOMEM;
1291
1292 if (list_empty(&sci->sc_write_logs)) {
1293 nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1294 nilfs->ns_pseg_offset, nilfs);
1295 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1296 nilfs_shift_to_next_segment(nilfs);
1297 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1298 }
1299
1300 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1301 nextnum = nilfs->ns_nextnum;
1302
1303 if (nilfs->ns_segnum == nilfs->ns_nextnum)
1304 /* Start from the head of a new full segment */
1305 alloc++;
1306 } else {
1307 /* Continue logs */
1308 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1309 nilfs_segbuf_map_cont(segbuf, prev);
1310 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1311 nextnum = prev->sb_nextnum;
1312
1313 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1314 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1315 segbuf->sb_sum.seg_seq++;
1316 alloc++;
1317 }
1318 }
1319
1320 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1321 if (err)
1322 goto failed;
1323
1324 if (alloc) {
1325 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1326 if (err)
1327 goto failed;
1328 }
1329 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1330
1331 BUG_ON(!list_empty(&sci->sc_segbufs));
1332 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1333 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1334 return 0;
1335
1336 failed:
1337 nilfs_segbuf_free(segbuf);
1338 return err;
1339 }
1340
1341 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1342 struct the_nilfs *nilfs, int nadd)
1343 {
1344 struct nilfs_segment_buffer *segbuf, *prev;
1345 struct inode *sufile = nilfs->ns_sufile;
1346 __u64 nextnextnum;
1347 LIST_HEAD(list);
1348 int err, ret, i;
1349
1350 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1351 /*
1352 * Since the segment specified with nextnum might be allocated during
1353 * the previous construction, the buffer including its segusage may
1354 * not be dirty. The following call ensures that the buffer is dirty
1355 * and will pin the buffer on memory until the sufile is written.
1356 */
1357 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1358 if (unlikely(err))
1359 return err;
1360
1361 for (i = 0; i < nadd; i++) {
1362 /* extend segment info */
1363 err = -ENOMEM;
1364 segbuf = nilfs_segbuf_new(sci->sc_super);
1365 if (unlikely(!segbuf))
1366 goto failed;
1367
1368 /* map this buffer to region of segment on-disk */
1369 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1370 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1371
1372 /* allocate the next next full segment */
1373 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1374 if (unlikely(err))
1375 goto failed_segbuf;
1376
1377 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1378 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1379
1380 list_add_tail(&segbuf->sb_list, &list);
1381 prev = segbuf;
1382 }
1383 list_splice_tail(&list, &sci->sc_segbufs);
1384 return 0;
1385
1386 failed_segbuf:
1387 nilfs_segbuf_free(segbuf);
1388 failed:
1389 list_for_each_entry(segbuf, &list, sb_list) {
1390 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1391 WARN_ON(ret); /* never fails */
1392 }
1393 nilfs_destroy_logs(&list);
1394 return err;
1395 }
1396
1397 static void nilfs_free_incomplete_logs(struct list_head *logs,
1398 struct the_nilfs *nilfs)
1399 {
1400 struct nilfs_segment_buffer *segbuf, *prev;
1401 struct inode *sufile = nilfs->ns_sufile;
1402 int ret;
1403
1404 segbuf = NILFS_FIRST_SEGBUF(logs);
1405 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1406 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1407 WARN_ON(ret); /* never fails */
1408 }
1409 if (atomic_read(&segbuf->sb_err)) {
1410 /* Case 1: The first segment failed */
1411 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1412 /* Case 1a: Partial segment appended into an existing
1413 segment */
1414 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1415 segbuf->sb_fseg_end);
1416 else /* Case 1b: New full segment */
1417 set_nilfs_discontinued(nilfs);
1418 }
1419
1420 prev = segbuf;
1421 list_for_each_entry_continue(segbuf, logs, sb_list) {
1422 if (prev->sb_nextnum != segbuf->sb_nextnum) {
1423 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1424 WARN_ON(ret); /* never fails */
1425 }
1426 if (atomic_read(&segbuf->sb_err) &&
1427 segbuf->sb_segnum != nilfs->ns_nextnum)
1428 /* Case 2: extended segment (!= next) failed */
1429 nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1430 prev = segbuf;
1431 }
1432 }
1433
1434 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1435 struct inode *sufile)
1436 {
1437 struct nilfs_segment_buffer *segbuf;
1438 unsigned long live_blocks;
1439 int ret;
1440
1441 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1442 live_blocks = segbuf->sb_sum.nblocks +
1443 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1444 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1445 live_blocks,
1446 sci->sc_seg_ctime);
1447 WARN_ON(ret); /* always succeed because the segusage is dirty */
1448 }
1449 }
1450
1451 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1452 {
1453 struct nilfs_segment_buffer *segbuf;
1454 int ret;
1455
1456 segbuf = NILFS_FIRST_SEGBUF(logs);
1457 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1458 segbuf->sb_pseg_start -
1459 segbuf->sb_fseg_start, 0);
1460 WARN_ON(ret); /* always succeed because the segusage is dirty */
1461
1462 list_for_each_entry_continue(segbuf, logs, sb_list) {
1463 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1464 0, 0);
1465 WARN_ON(ret); /* always succeed */
1466 }
1467 }
1468
1469 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1470 struct nilfs_segment_buffer *last,
1471 struct inode *sufile)
1472 {
1473 struct nilfs_segment_buffer *segbuf = last;
1474 int ret;
1475
1476 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1477 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1478 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1479 WARN_ON(ret);
1480 }
1481 nilfs_truncate_logs(&sci->sc_segbufs, last);
1482 }
1483
1484
1485 static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1486 struct the_nilfs *nilfs, int mode)
1487 {
1488 struct nilfs_cstage prev_stage = sci->sc_stage;
1489 int err, nadd = 1;
1490
1491 /* Collection retry loop */
1492 for (;;) {
1493 sci->sc_super_root = NULL;
1494 sci->sc_nblk_this_inc = 0;
1495 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1496
1497 err = nilfs_segctor_reset_segment_buffer(sci);
1498 if (unlikely(err))
1499 goto failed;
1500
1501 err = nilfs_segctor_collect_blocks(sci, mode);
1502 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1503 if (!err)
1504 break;
1505
1506 if (unlikely(err != -E2BIG))
1507 goto failed;
1508
1509 /* The current segment is filled up */
1510 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
1511 break;
1512
1513 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1514 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1515 sci->sc_freesegs,
1516 sci->sc_nfreesegs,
1517 NULL);
1518 WARN_ON(err); /* do not happen */
1519 }
1520 nilfs_clear_logs(&sci->sc_segbufs);
1521
1522 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1523 if (unlikely(err))
1524 return err;
1525
1526 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1527 sci->sc_stage = prev_stage;
1528 }
1529 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1530 return 0;
1531
1532 failed:
1533 return err;
1534 }
1535
1536 static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1537 struct buffer_head *new_bh)
1538 {
1539 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1540
1541 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1542 /* The caller must release old_bh */
1543 }
1544
1545 static int
1546 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1547 struct nilfs_segment_buffer *segbuf,
1548 int mode)
1549 {
1550 struct inode *inode = NULL;
1551 sector_t blocknr;
1552 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1553 unsigned long nblocks = 0, ndatablk = 0;
1554 struct nilfs_sc_operations *sc_op = NULL;
1555 struct nilfs_segsum_pointer ssp;
1556 struct nilfs_finfo *finfo = NULL;
1557 union nilfs_binfo binfo;
1558 struct buffer_head *bh, *bh_org;
1559 ino_t ino = 0;
1560 int err = 0;
1561
1562 if (!nfinfo)
1563 goto out;
1564
1565 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1566 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1567 ssp.offset = sizeof(struct nilfs_segment_summary);
1568
1569 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1570 if (bh == sci->sc_super_root)
1571 break;
1572 if (!finfo) {
1573 finfo = nilfs_segctor_map_segsum_entry(
1574 sci, &ssp, sizeof(*finfo));
1575 ino = le64_to_cpu(finfo->fi_ino);
1576 nblocks = le32_to_cpu(finfo->fi_nblocks);
1577 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1578
1579 if (buffer_nilfs_node(bh))
1580 inode = NILFS_BTNC_I(bh->b_page->mapping);
1581 else
1582 inode = NILFS_AS_I(bh->b_page->mapping);
1583
1584 if (mode == SC_LSEG_DSYNC)
1585 sc_op = &nilfs_sc_dsync_ops;
1586 else if (ino == NILFS_DAT_INO)
1587 sc_op = &nilfs_sc_dat_ops;
1588 else /* file blocks */
1589 sc_op = &nilfs_sc_file_ops;
1590 }
1591 bh_org = bh;
1592 get_bh(bh_org);
1593 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1594 &binfo);
1595 if (bh != bh_org)
1596 nilfs_list_replace_buffer(bh_org, bh);
1597 brelse(bh_org);
1598 if (unlikely(err))
1599 goto failed_bmap;
1600
1601 if (ndatablk > 0)
1602 sc_op->write_data_binfo(sci, &ssp, &binfo);
1603 else
1604 sc_op->write_node_binfo(sci, &ssp, &binfo);
1605
1606 blocknr++;
1607 if (--nblocks == 0) {
1608 finfo = NULL;
1609 if (--nfinfo == 0)
1610 break;
1611 } else if (ndatablk > 0)
1612 ndatablk--;
1613 }
1614 out:
1615 return 0;
1616
1617 failed_bmap:
1618 err = nilfs_handle_bmap_error(err, __func__, inode, sci->sc_super);
1619 return err;
1620 }
1621
1622 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1623 {
1624 struct nilfs_segment_buffer *segbuf;
1625 int err;
1626
1627 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1628 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1629 if (unlikely(err))
1630 return err;
1631 nilfs_segbuf_fill_in_segsum(segbuf);
1632 }
1633 return 0;
1634 }
1635
1636 static int
1637 nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out)
1638 {
1639 struct page *clone_page;
1640 struct buffer_head *bh, *head, *bh2;
1641 void *kaddr;
1642
1643 bh = head = page_buffers(page);
1644
1645 clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0);
1646 if (unlikely(!clone_page))
1647 return -ENOMEM;
1648
1649 bh2 = page_buffers(clone_page);
1650 kaddr = kmap_atomic(page, KM_USER0);
1651 do {
1652 if (list_empty(&bh->b_assoc_buffers))
1653 continue;
1654 get_bh(bh2);
1655 page_cache_get(clone_page); /* for each bh */
1656 memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size);
1657 bh2->b_blocknr = bh->b_blocknr;
1658 list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers);
1659 list_add_tail(&bh->b_assoc_buffers, out);
1660 } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head);
1661 kunmap_atomic(kaddr, KM_USER0);
1662
1663 if (!TestSetPageWriteback(clone_page))
1664 inc_zone_page_state(clone_page, NR_WRITEBACK);
1665 unlock_page(clone_page);
1666
1667 return 0;
1668 }
1669
1670 static int nilfs_test_page_to_be_frozen(struct page *page)
1671 {
1672 struct address_space *mapping = page->mapping;
1673
1674 if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode))
1675 return 0;
1676
1677 if (page_mapped(page)) {
1678 ClearPageChecked(page);
1679 return 1;
1680 }
1681 return PageChecked(page);
1682 }
1683
1684 static int nilfs_begin_page_io(struct page *page, struct list_head *out)
1685 {
1686 if (!page || PageWriteback(page))
1687 /* For split b-tree node pages, this function may be called
1688 twice. We ignore the 2nd or later calls by this check. */
1689 return 0;
1690
1691 lock_page(page);
1692 clear_page_dirty_for_io(page);
1693 set_page_writeback(page);
1694 unlock_page(page);
1695
1696 if (nilfs_test_page_to_be_frozen(page)) {
1697 int err = nilfs_copy_replace_page_buffers(page, out);
1698 if (unlikely(err))
1699 return err;
1700 }
1701 return 0;
1702 }
1703
1704 static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
1705 struct page **failed_page)
1706 {
1707 struct nilfs_segment_buffer *segbuf;
1708 struct page *bd_page = NULL, *fs_page = NULL;
1709 struct list_head *list = &sci->sc_copied_buffers;
1710 int err;
1711
1712 *failed_page = NULL;
1713 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1714 struct buffer_head *bh;
1715
1716 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1717 b_assoc_buffers) {
1718 if (bh->b_page != bd_page) {
1719 if (bd_page) {
1720 lock_page(bd_page);
1721 clear_page_dirty_for_io(bd_page);
1722 set_page_writeback(bd_page);
1723 unlock_page(bd_page);
1724 }
1725 bd_page = bh->b_page;
1726 }
1727 }
1728
1729 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1730 b_assoc_buffers) {
1731 if (bh == sci->sc_super_root) {
1732 if (bh->b_page != bd_page) {
1733 lock_page(bd_page);
1734 clear_page_dirty_for_io(bd_page);
1735 set_page_writeback(bd_page);
1736 unlock_page(bd_page);
1737 bd_page = bh->b_page;
1738 }
1739 break;
1740 }
1741 if (bh->b_page != fs_page) {
1742 err = nilfs_begin_page_io(fs_page, list);
1743 if (unlikely(err)) {
1744 *failed_page = fs_page;
1745 goto out;
1746 }
1747 fs_page = bh->b_page;
1748 }
1749 }
1750 }
1751 if (bd_page) {
1752 lock_page(bd_page);
1753 clear_page_dirty_for_io(bd_page);
1754 set_page_writeback(bd_page);
1755 unlock_page(bd_page);
1756 }
1757 err = nilfs_begin_page_io(fs_page, list);
1758 if (unlikely(err))
1759 *failed_page = fs_page;
1760 out:
1761 return err;
1762 }
1763
1764 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1765 struct the_nilfs *nilfs)
1766 {
1767 struct nilfs_segment_buffer *segbuf;
1768 int ret = 0;
1769
1770 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1771 ret = nilfs_segbuf_write(segbuf, nilfs);
1772 if (ret)
1773 break;
1774 }
1775 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1776 return ret;
1777 }
1778
1779 static void __nilfs_end_page_io(struct page *page, int err)
1780 {
1781 if (!err) {
1782 if (!nilfs_page_buffers_clean(page))
1783 __set_page_dirty_nobuffers(page);
1784 ClearPageError(page);
1785 } else {
1786 __set_page_dirty_nobuffers(page);
1787 SetPageError(page);
1788 }
1789
1790 if (buffer_nilfs_allocated(page_buffers(page))) {
1791 if (TestClearPageWriteback(page))
1792 dec_zone_page_state(page, NR_WRITEBACK);
1793 } else
1794 end_page_writeback(page);
1795 }
1796
1797 static void nilfs_end_page_io(struct page *page, int err)
1798 {
1799 if (!page)
1800 return;
1801
1802 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
1803 /*
1804 * For b-tree node pages, this function may be called twice
1805 * or more because they might be split in a segment.
1806 */
1807 if (PageDirty(page)) {
1808 /*
1809 * For pages holding split b-tree node buffers, dirty
1810 * flag on the buffers may be cleared discretely.
1811 * In that case, the page is once redirtied for
1812 * remaining buffers, and it must be cancelled if
1813 * all the buffers get cleaned later.
1814 */
1815 lock_page(page);
1816 if (nilfs_page_buffers_clean(page))
1817 __nilfs_clear_page_dirty(page);
1818 unlock_page(page);
1819 }
1820 return;
1821 }
1822
1823 __nilfs_end_page_io(page, err);
1824 }
1825
1826 static void nilfs_clear_copied_buffers(struct list_head *list, int err)
1827 {
1828 struct buffer_head *bh, *head;
1829 struct page *page;
1830
1831 while (!list_empty(list)) {
1832 bh = list_entry(list->next, struct buffer_head,
1833 b_assoc_buffers);
1834 page = bh->b_page;
1835 page_cache_get(page);
1836 head = bh = page_buffers(page);
1837 do {
1838 if (!list_empty(&bh->b_assoc_buffers)) {
1839 list_del_init(&bh->b_assoc_buffers);
1840 if (!err) {
1841 set_buffer_uptodate(bh);
1842 clear_buffer_dirty(bh);
1843 clear_buffer_nilfs_volatile(bh);
1844 }
1845 brelse(bh); /* for b_assoc_buffers */
1846 }
1847 } while ((bh = bh->b_this_page) != head);
1848
1849 __nilfs_end_page_io(page, err);
1850 page_cache_release(page);
1851 }
1852 }
1853
1854 static void nilfs_abort_logs(struct list_head *logs, struct page *failed_page,
1855 struct buffer_head *bh_sr, int err)
1856 {
1857 struct nilfs_segment_buffer *segbuf;
1858 struct page *bd_page = NULL, *fs_page = NULL;
1859 struct buffer_head *bh;
1860
1861 if (list_empty(logs))
1862 return;
1863
1864 list_for_each_entry(segbuf, logs, sb_list) {
1865 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1866 b_assoc_buffers) {
1867 if (bh->b_page != bd_page) {
1868 if (bd_page)
1869 end_page_writeback(bd_page);
1870 bd_page = bh->b_page;
1871 }
1872 }
1873
1874 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1875 b_assoc_buffers) {
1876 if (bh == bh_sr) {
1877 if (bh->b_page != bd_page) {
1878 end_page_writeback(bd_page);
1879 bd_page = bh->b_page;
1880 }
1881 break;
1882 }
1883 if (bh->b_page != fs_page) {
1884 nilfs_end_page_io(fs_page, err);
1885 if (fs_page && fs_page == failed_page)
1886 return;
1887 fs_page = bh->b_page;
1888 }
1889 }
1890 }
1891 if (bd_page)
1892 end_page_writeback(bd_page);
1893
1894 nilfs_end_page_io(fs_page, err);
1895 }
1896
1897 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1898 struct the_nilfs *nilfs, int err)
1899 {
1900 LIST_HEAD(logs);
1901 int ret;
1902
1903 list_splice_tail_init(&sci->sc_write_logs, &logs);
1904 ret = nilfs_wait_on_logs(&logs);
1905 nilfs_abort_logs(&logs, NULL, sci->sc_super_root, ret ? : err);
1906
1907 list_splice_tail_init(&sci->sc_segbufs, &logs);
1908 nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1909 nilfs_free_incomplete_logs(&logs, nilfs);
1910 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err);
1911
1912 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1913 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1914 sci->sc_freesegs,
1915 sci->sc_nfreesegs,
1916 NULL);
1917 WARN_ON(ret); /* do not happen */
1918 }
1919
1920 nilfs_destroy_logs(&logs);
1921 sci->sc_super_root = NULL;
1922 }
1923
1924 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1925 struct nilfs_segment_buffer *segbuf)
1926 {
1927 nilfs->ns_segnum = segbuf->sb_segnum;
1928 nilfs->ns_nextnum = segbuf->sb_nextnum;
1929 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1930 + segbuf->sb_sum.nblocks;
1931 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1932 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1933 }
1934
1935 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1936 {
1937 struct nilfs_segment_buffer *segbuf;
1938 struct page *bd_page = NULL, *fs_page = NULL;
1939 struct nilfs_sb_info *sbi = sci->sc_sbi;
1940 struct the_nilfs *nilfs = sbi->s_nilfs;
1941 int update_sr = (sci->sc_super_root != NULL);
1942
1943 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1944 struct buffer_head *bh;
1945
1946 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1947 b_assoc_buffers) {
1948 set_buffer_uptodate(bh);
1949 clear_buffer_dirty(bh);
1950 if (bh->b_page != bd_page) {
1951 if (bd_page)
1952 end_page_writeback(bd_page);
1953 bd_page = bh->b_page;
1954 }
1955 }
1956 /*
1957 * We assume that the buffers which belong to the same page
1958 * continue over the buffer list.
1959 * Under this assumption, the last BHs of pages is
1960 * identifiable by the discontinuity of bh->b_page
1961 * (page != fs_page).
1962 *
1963 * For B-tree node blocks, however, this assumption is not
1964 * guaranteed. The cleanup code of B-tree node pages needs
1965 * special care.
1966 */
1967 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1968 b_assoc_buffers) {
1969 set_buffer_uptodate(bh);
1970 clear_buffer_dirty(bh);
1971 clear_buffer_nilfs_volatile(bh);
1972 if (bh == sci->sc_super_root) {
1973 if (bh->b_page != bd_page) {
1974 end_page_writeback(bd_page);
1975 bd_page = bh->b_page;
1976 }
1977 break;
1978 }
1979 if (bh->b_page != fs_page) {
1980 nilfs_end_page_io(fs_page, 0);
1981 fs_page = bh->b_page;
1982 }
1983 }
1984
1985 if (!NILFS_SEG_SIMPLEX(&segbuf->sb_sum)) {
1986 if (NILFS_SEG_LOGBGN(&segbuf->sb_sum)) {
1987 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1988 sci->sc_lseg_stime = jiffies;
1989 }
1990 if (NILFS_SEG_LOGEND(&segbuf->sb_sum))
1991 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1992 }
1993 }
1994 /*
1995 * Since pages may continue over multiple segment buffers,
1996 * end of the last page must be checked outside of the loop.
1997 */
1998 if (bd_page)
1999 end_page_writeback(bd_page);
2000
2001 nilfs_end_page_io(fs_page, 0);
2002
2003 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, 0);
2004
2005 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
2006
2007 if (nilfs_doing_gc()) {
2008 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
2009 if (update_sr)
2010 nilfs_commit_gcdat_inode(nilfs);
2011 } else
2012 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
2013
2014 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
2015
2016 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
2017 nilfs_set_next_segment(nilfs, segbuf);
2018
2019 if (update_sr) {
2020 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
2021 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
2022 sbi->s_super->s_dirt = 1;
2023
2024 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
2025 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2026 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
2027 nilfs_segctor_clear_metadata_dirty(sci);
2028 } else
2029 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
2030 }
2031
2032 static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
2033 {
2034 int ret;
2035
2036 ret = nilfs_wait_on_logs(&sci->sc_write_logs);
2037 if (!ret) {
2038 nilfs_segctor_complete_write(sci);
2039 nilfs_destroy_logs(&sci->sc_write_logs);
2040 }
2041 return ret;
2042 }
2043
2044 static int nilfs_segctor_check_in_files(struct nilfs_sc_info *sci,
2045 struct nilfs_sb_info *sbi)
2046 {
2047 struct nilfs_inode_info *ii, *n;
2048 __u64 cno = sbi->s_nilfs->ns_cno;
2049
2050 spin_lock(&sbi->s_inode_lock);
2051 retry:
2052 list_for_each_entry_safe(ii, n, &sbi->s_dirty_files, i_dirty) {
2053 if (!ii->i_bh) {
2054 struct buffer_head *ibh;
2055 int err;
2056
2057 spin_unlock(&sbi->s_inode_lock);
2058 err = nilfs_ifile_get_inode_block(
2059 sbi->s_ifile, ii->vfs_inode.i_ino, &ibh);
2060 if (unlikely(err)) {
2061 nilfs_warning(sbi->s_super, __func__,
2062 "failed to get inode block.\n");
2063 return err;
2064 }
2065 nilfs_mdt_mark_buffer_dirty(ibh);
2066 nilfs_mdt_mark_dirty(sbi->s_ifile);
2067 spin_lock(&sbi->s_inode_lock);
2068 if (likely(!ii->i_bh))
2069 ii->i_bh = ibh;
2070 else
2071 brelse(ibh);
2072 goto retry;
2073 }
2074 ii->i_cno = cno;
2075
2076 clear_bit(NILFS_I_QUEUED, &ii->i_state);
2077 set_bit(NILFS_I_BUSY, &ii->i_state);
2078 list_del(&ii->i_dirty);
2079 list_add_tail(&ii->i_dirty, &sci->sc_dirty_files);
2080 }
2081 spin_unlock(&sbi->s_inode_lock);
2082
2083 NILFS_I(sbi->s_ifile)->i_cno = cno;
2084
2085 return 0;
2086 }
2087
2088 static void nilfs_segctor_check_out_files(struct nilfs_sc_info *sci,
2089 struct nilfs_sb_info *sbi)
2090 {
2091 struct nilfs_transaction_info *ti = current->journal_info;
2092 struct nilfs_inode_info *ii, *n;
2093 __u64 cno = sbi->s_nilfs->ns_cno;
2094
2095 spin_lock(&sbi->s_inode_lock);
2096 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
2097 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
2098 test_bit(NILFS_I_DIRTY, &ii->i_state)) {
2099 /* The current checkpoint number (=nilfs->ns_cno) is
2100 changed between check-in and check-out only if the
2101 super root is written out. So, we can update i_cno
2102 for the inodes that remain in the dirty list. */
2103 ii->i_cno = cno;
2104 continue;
2105 }
2106 clear_bit(NILFS_I_BUSY, &ii->i_state);
2107 brelse(ii->i_bh);
2108 ii->i_bh = NULL;
2109 list_del(&ii->i_dirty);
2110 list_add_tail(&ii->i_dirty, &ti->ti_garbage);
2111 }
2112 spin_unlock(&sbi->s_inode_lock);
2113 }
2114
2115 /*
2116 * Main procedure of segment constructor
2117 */
2118 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2119 {
2120 struct nilfs_sb_info *sbi = sci->sc_sbi;
2121 struct the_nilfs *nilfs = sbi->s_nilfs;
2122 struct page *failed_page;
2123 int err, has_sr = 0;
2124
2125 sci->sc_stage.scnt = NILFS_ST_INIT;
2126
2127 err = nilfs_segctor_check_in_files(sci, sbi);
2128 if (unlikely(err))
2129 goto out;
2130
2131 if (nilfs_test_metadata_dirty(sbi))
2132 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2133
2134 if (nilfs_segctor_clean(sci))
2135 goto out;
2136
2137 do {
2138 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2139
2140 err = nilfs_segctor_begin_construction(sci, nilfs);
2141 if (unlikely(err))
2142 goto out;
2143
2144 /* Update time stamp */
2145 sci->sc_seg_ctime = get_seconds();
2146
2147 err = nilfs_segctor_collect(sci, nilfs, mode);
2148 if (unlikely(err))
2149 goto failed;
2150
2151 has_sr = (sci->sc_super_root != NULL);
2152
2153 /* Avoid empty segment */
2154 if (sci->sc_stage.scnt == NILFS_ST_DONE &&
2155 NILFS_SEG_EMPTY(&sci->sc_curseg->sb_sum)) {
2156 nilfs_segctor_abort_construction(sci, nilfs, 1);
2157 goto out;
2158 }
2159
2160 err = nilfs_segctor_assign(sci, mode);
2161 if (unlikely(err))
2162 goto failed;
2163
2164 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2165 nilfs_segctor_fill_in_file_bmap(sci, sbi->s_ifile);
2166
2167 if (has_sr) {
2168 err = nilfs_segctor_fill_in_checkpoint(sci);
2169 if (unlikely(err))
2170 goto failed_to_write;
2171
2172 nilfs_segctor_fill_in_super_root(sci, nilfs);
2173 }
2174 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2175
2176 /* Write partial segments */
2177 err = nilfs_segctor_prepare_write(sci, &failed_page);
2178 if (err) {
2179 nilfs_abort_logs(&sci->sc_segbufs, failed_page,
2180 sci->sc_super_root, err);
2181 goto failed_to_write;
2182 }
2183 nilfs_segctor_fill_in_checksums(sci, nilfs->ns_crc_seed);
2184
2185 err = nilfs_segctor_write(sci, nilfs);
2186 if (unlikely(err))
2187 goto failed_to_write;
2188
2189 if (sci->sc_stage.scnt == NILFS_ST_DONE ||
2190 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
2191 /*
2192 * At this point, we avoid double buffering
2193 * for blocksize < pagesize because page dirty
2194 * flag is turned off during write and dirty
2195 * buffers are not properly collected for
2196 * pages crossing over segments.
2197 */
2198 err = nilfs_segctor_wait(sci);
2199 if (err)
2200 goto failed_to_write;
2201 }
2202 } while (sci->sc_stage.scnt != NILFS_ST_DONE);
2203
2204 sci->sc_super_root = NULL;
2205
2206 out:
2207 nilfs_segctor_check_out_files(sci, sbi);
2208 return err;
2209
2210 failed_to_write:
2211 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2212 nilfs_redirty_inodes(&sci->sc_dirty_files);
2213
2214 failed:
2215 if (nilfs_doing_gc())
2216 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2217 nilfs_segctor_abort_construction(sci, nilfs, err);
2218 goto out;
2219 }
2220
2221 /**
2222 * nilfs_secgtor_start_timer - set timer of background write
2223 * @sci: nilfs_sc_info
2224 *
2225 * If the timer has already been set, it ignores the new request.
2226 * This function MUST be called within a section locking the segment
2227 * semaphore.
2228 */
2229 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2230 {
2231 spin_lock(&sci->sc_state_lock);
2232 if (sci->sc_timer && !(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2233 sci->sc_timer->expires = jiffies + sci->sc_interval;
2234 add_timer(sci->sc_timer);
2235 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2236 }
2237 spin_unlock(&sci->sc_state_lock);
2238 }
2239
2240 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2241 {
2242 spin_lock(&sci->sc_state_lock);
2243 if (!(sci->sc_flush_request & (1 << bn))) {
2244 unsigned long prev_req = sci->sc_flush_request;
2245
2246 sci->sc_flush_request |= (1 << bn);
2247 if (!prev_req)
2248 wake_up(&sci->sc_wait_daemon);
2249 }
2250 spin_unlock(&sci->sc_state_lock);
2251 }
2252
2253 /**
2254 * nilfs_flush_segment - trigger a segment construction for resource control
2255 * @sb: super block
2256 * @ino: inode number of the file to be flushed out.
2257 */
2258 void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2259 {
2260 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2261 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2262
2263 if (!sci || nilfs_doing_construction())
2264 return;
2265 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2266 /* assign bit 0 to data files */
2267 }
2268
2269 struct nilfs_segctor_wait_request {
2270 wait_queue_t wq;
2271 __u32 seq;
2272 int err;
2273 atomic_t done;
2274 };
2275
2276 static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2277 {
2278 struct nilfs_segctor_wait_request wait_req;
2279 int err = 0;
2280
2281 spin_lock(&sci->sc_state_lock);
2282 init_wait(&wait_req.wq);
2283 wait_req.err = 0;
2284 atomic_set(&wait_req.done, 0);
2285 wait_req.seq = ++sci->sc_seq_request;
2286 spin_unlock(&sci->sc_state_lock);
2287
2288 init_waitqueue_entry(&wait_req.wq, current);
2289 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2290 set_current_state(TASK_INTERRUPTIBLE);
2291 wake_up(&sci->sc_wait_daemon);
2292
2293 for (;;) {
2294 if (atomic_read(&wait_req.done)) {
2295 err = wait_req.err;
2296 break;
2297 }
2298 if (!signal_pending(current)) {
2299 schedule();
2300 continue;
2301 }
2302 err = -ERESTARTSYS;
2303 break;
2304 }
2305 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2306 return err;
2307 }
2308
2309 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2310 {
2311 struct nilfs_segctor_wait_request *wrq, *n;
2312 unsigned long flags;
2313
2314 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2315 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2316 wq.task_list) {
2317 if (!atomic_read(&wrq->done) &&
2318 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2319 wrq->err = err;
2320 atomic_set(&wrq->done, 1);
2321 }
2322 if (atomic_read(&wrq->done)) {
2323 wrq->wq.func(&wrq->wq,
2324 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2325 0, NULL);
2326 }
2327 }
2328 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2329 }
2330
2331 /**
2332 * nilfs_construct_segment - construct a logical segment
2333 * @sb: super block
2334 *
2335 * Return Value: On success, 0 is retured. On errors, one of the following
2336 * negative error code is returned.
2337 *
2338 * %-EROFS - Read only filesystem.
2339 *
2340 * %-EIO - I/O error
2341 *
2342 * %-ENOSPC - No space left on device (only in a panic state).
2343 *
2344 * %-ERESTARTSYS - Interrupted.
2345 *
2346 * %-ENOMEM - Insufficient memory available.
2347 */
2348 int nilfs_construct_segment(struct super_block *sb)
2349 {
2350 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2351 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2352 struct nilfs_transaction_info *ti;
2353 int err;
2354
2355 if (!sci)
2356 return -EROFS;
2357
2358 /* A call inside transactions causes a deadlock. */
2359 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2360
2361 err = nilfs_segctor_sync(sci);
2362 return err;
2363 }
2364
2365 /**
2366 * nilfs_construct_dsync_segment - construct a data-only logical segment
2367 * @sb: super block
2368 * @inode: inode whose data blocks should be written out
2369 * @start: start byte offset
2370 * @end: end byte offset (inclusive)
2371 *
2372 * Return Value: On success, 0 is retured. On errors, one of the following
2373 * negative error code is returned.
2374 *
2375 * %-EROFS - Read only filesystem.
2376 *
2377 * %-EIO - I/O error
2378 *
2379 * %-ENOSPC - No space left on device (only in a panic state).
2380 *
2381 * %-ERESTARTSYS - Interrupted.
2382 *
2383 * %-ENOMEM - Insufficient memory available.
2384 */
2385 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2386 loff_t start, loff_t end)
2387 {
2388 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2389 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2390 struct nilfs_inode_info *ii;
2391 struct nilfs_transaction_info ti;
2392 int err = 0;
2393
2394 if (!sci)
2395 return -EROFS;
2396
2397 nilfs_transaction_lock(sbi, &ti, 0);
2398
2399 ii = NILFS_I(inode);
2400 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
2401 nilfs_test_opt(sbi, STRICT_ORDER) ||
2402 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2403 nilfs_discontinued(sbi->s_nilfs)) {
2404 nilfs_transaction_unlock(sbi);
2405 err = nilfs_segctor_sync(sci);
2406 return err;
2407 }
2408
2409 spin_lock(&sbi->s_inode_lock);
2410 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2411 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2412 spin_unlock(&sbi->s_inode_lock);
2413 nilfs_transaction_unlock(sbi);
2414 return 0;
2415 }
2416 spin_unlock(&sbi->s_inode_lock);
2417 sci->sc_dsync_inode = ii;
2418 sci->sc_dsync_start = start;
2419 sci->sc_dsync_end = end;
2420
2421 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2422
2423 nilfs_transaction_unlock(sbi);
2424 return err;
2425 }
2426
2427 struct nilfs_segctor_req {
2428 int mode;
2429 __u32 seq_accepted;
2430 int sc_err; /* construction failure */
2431 int sb_err; /* super block writeback failure */
2432 };
2433
2434 #define FLUSH_FILE_BIT (0x1) /* data file only */
2435 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2436
2437 static void nilfs_segctor_accept(struct nilfs_sc_info *sci,
2438 struct nilfs_segctor_req *req)
2439 {
2440 req->sc_err = req->sb_err = 0;
2441 spin_lock(&sci->sc_state_lock);
2442 req->seq_accepted = sci->sc_seq_request;
2443 spin_unlock(&sci->sc_state_lock);
2444
2445 if (sci->sc_timer)
2446 del_timer_sync(sci->sc_timer);
2447 }
2448
2449 static void nilfs_segctor_notify(struct nilfs_sc_info *sci,
2450 struct nilfs_segctor_req *req)
2451 {
2452 /* Clear requests (even when the construction failed) */
2453 spin_lock(&sci->sc_state_lock);
2454
2455 if (req->mode == SC_LSEG_SR) {
2456 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2457 sci->sc_seq_done = req->seq_accepted;
2458 nilfs_segctor_wakeup(sci, req->sc_err ? : req->sb_err);
2459 sci->sc_flush_request = 0;
2460 } else {
2461 if (req->mode == SC_FLUSH_FILE)
2462 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2463 else if (req->mode == SC_FLUSH_DAT)
2464 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2465
2466 /* re-enable timer if checkpoint creation was not done */
2467 if (sci->sc_timer && (sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2468 time_before(jiffies, sci->sc_timer->expires))
2469 add_timer(sci->sc_timer);
2470 }
2471 spin_unlock(&sci->sc_state_lock);
2472 }
2473
2474 static int nilfs_segctor_construct(struct nilfs_sc_info *sci,
2475 struct nilfs_segctor_req *req)
2476 {
2477 struct nilfs_sb_info *sbi = sci->sc_sbi;
2478 struct the_nilfs *nilfs = sbi->s_nilfs;
2479 int err = 0;
2480
2481 if (nilfs_discontinued(nilfs))
2482 req->mode = SC_LSEG_SR;
2483 if (!nilfs_segctor_confirm(sci)) {
2484 err = nilfs_segctor_do_construct(sci, req->mode);
2485 req->sc_err = err;
2486 }
2487 if (likely(!err)) {
2488 if (req->mode != SC_FLUSH_DAT)
2489 atomic_set(&nilfs->ns_ndirtyblks, 0);
2490 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2491 nilfs_discontinued(nilfs)) {
2492 down_write(&nilfs->ns_sem);
2493 req->sb_err = nilfs_commit_super(sbi,
2494 nilfs_altsb_need_update(nilfs));
2495 up_write(&nilfs->ns_sem);
2496 }
2497 }
2498 return err;
2499 }
2500
2501 static void nilfs_construction_timeout(unsigned long data)
2502 {
2503 struct task_struct *p = (struct task_struct *)data;
2504 wake_up_process(p);
2505 }
2506
2507 static void
2508 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2509 {
2510 struct nilfs_inode_info *ii, *n;
2511
2512 list_for_each_entry_safe(ii, n, head, i_dirty) {
2513 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2514 continue;
2515 hlist_del_init(&ii->vfs_inode.i_hash);
2516 list_del_init(&ii->i_dirty);
2517 nilfs_clear_gcinode(&ii->vfs_inode);
2518 }
2519 }
2520
2521 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2522 void **kbufs)
2523 {
2524 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2525 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2526 struct the_nilfs *nilfs = sbi->s_nilfs;
2527 struct nilfs_transaction_info ti;
2528 struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
2529 int err;
2530
2531 if (unlikely(!sci))
2532 return -EROFS;
2533
2534 nilfs_transaction_lock(sbi, &ti, 1);
2535
2536 err = nilfs_init_gcdat_inode(nilfs);
2537 if (unlikely(err))
2538 goto out_unlock;
2539
2540 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2541 if (unlikely(err))
2542 goto out_unlock;
2543
2544 sci->sc_freesegs = kbufs[4];
2545 sci->sc_nfreesegs = argv[4].v_nmembs;
2546 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2547
2548 for (;;) {
2549 nilfs_segctor_accept(sci, &req);
2550 err = nilfs_segctor_construct(sci, &req);
2551 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2552 nilfs_segctor_notify(sci, &req);
2553
2554 if (likely(!err))
2555 break;
2556
2557 nilfs_warning(sb, __func__,
2558 "segment construction failed. (err=%d)", err);
2559 set_current_state(TASK_INTERRUPTIBLE);
2560 schedule_timeout(sci->sc_interval);
2561 }
2562
2563 out_unlock:
2564 sci->sc_freesegs = NULL;
2565 sci->sc_nfreesegs = 0;
2566 nilfs_clear_gcdat_inode(nilfs);
2567 nilfs_transaction_unlock(sbi);
2568 return err;
2569 }
2570
2571 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2572 {
2573 struct nilfs_sb_info *sbi = sci->sc_sbi;
2574 struct nilfs_transaction_info ti;
2575 struct nilfs_segctor_req req = { .mode = mode };
2576
2577 nilfs_transaction_lock(sbi, &ti, 0);
2578
2579 nilfs_segctor_accept(sci, &req);
2580 nilfs_segctor_construct(sci, &req);
2581 nilfs_segctor_notify(sci, &req);
2582
2583 /*
2584 * Unclosed segment should be retried. We do this using sc_timer.
2585 * Timeout of sc_timer will invoke complete construction which leads
2586 * to close the current logical segment.
2587 */
2588 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2589 nilfs_segctor_start_timer(sci);
2590
2591 nilfs_transaction_unlock(sbi);
2592 }
2593
2594 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2595 {
2596 int mode = 0;
2597 int err;
2598
2599 spin_lock(&sci->sc_state_lock);
2600 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2601 SC_FLUSH_DAT : SC_FLUSH_FILE;
2602 spin_unlock(&sci->sc_state_lock);
2603
2604 if (mode) {
2605 err = nilfs_segctor_do_construct(sci, mode);
2606
2607 spin_lock(&sci->sc_state_lock);
2608 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2609 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2610 spin_unlock(&sci->sc_state_lock);
2611 }
2612 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2613 }
2614
2615 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2616 {
2617 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2618 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2619 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2620 return SC_FLUSH_FILE;
2621 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2622 return SC_FLUSH_DAT;
2623 }
2624 return SC_LSEG_SR;
2625 }
2626
2627 /**
2628 * nilfs_segctor_thread - main loop of the segment constructor thread.
2629 * @arg: pointer to a struct nilfs_sc_info.
2630 *
2631 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2632 * to execute segment constructions.
2633 */
2634 static int nilfs_segctor_thread(void *arg)
2635 {
2636 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2637 struct timer_list timer;
2638 int timeout = 0;
2639
2640 init_timer(&timer);
2641 timer.data = (unsigned long)current;
2642 timer.function = nilfs_construction_timeout;
2643 sci->sc_timer = &timer;
2644
2645 /* start sync. */
2646 sci->sc_task = current;
2647 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2648 printk(KERN_INFO
2649 "segctord starting. Construction interval = %lu seconds, "
2650 "CP frequency < %lu seconds\n",
2651 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2652
2653 spin_lock(&sci->sc_state_lock);
2654 loop:
2655 for (;;) {
2656 int mode;
2657
2658 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2659 goto end_thread;
2660
2661 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2662 mode = SC_LSEG_SR;
2663 else if (!sci->sc_flush_request)
2664 break;
2665 else
2666 mode = nilfs_segctor_flush_mode(sci);
2667
2668 spin_unlock(&sci->sc_state_lock);
2669 nilfs_segctor_thread_construct(sci, mode);
2670 spin_lock(&sci->sc_state_lock);
2671 timeout = 0;
2672 }
2673
2674
2675 if (freezing(current)) {
2676 spin_unlock(&sci->sc_state_lock);
2677 refrigerator();
2678 spin_lock(&sci->sc_state_lock);
2679 } else {
2680 DEFINE_WAIT(wait);
2681 int should_sleep = 1;
2682 struct the_nilfs *nilfs;
2683
2684 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2685 TASK_INTERRUPTIBLE);
2686
2687 if (sci->sc_seq_request != sci->sc_seq_done)
2688 should_sleep = 0;
2689 else if (sci->sc_flush_request)
2690 should_sleep = 0;
2691 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2692 should_sleep = time_before(jiffies,
2693 sci->sc_timer->expires);
2694
2695 if (should_sleep) {
2696 spin_unlock(&sci->sc_state_lock);
2697 schedule();
2698 spin_lock(&sci->sc_state_lock);
2699 }
2700 finish_wait(&sci->sc_wait_daemon, &wait);
2701 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2702 time_after_eq(jiffies, sci->sc_timer->expires));
2703 nilfs = sci->sc_sbi->s_nilfs;
2704 if (sci->sc_super->s_dirt && nilfs_sb_need_update(nilfs))
2705 set_nilfs_discontinued(nilfs);
2706 }
2707 goto loop;
2708
2709 end_thread:
2710 spin_unlock(&sci->sc_state_lock);
2711 del_timer_sync(sci->sc_timer);
2712 sci->sc_timer = NULL;
2713
2714 /* end sync. */
2715 sci->sc_task = NULL;
2716 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2717 return 0;
2718 }
2719
2720 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2721 {
2722 struct task_struct *t;
2723
2724 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2725 if (IS_ERR(t)) {
2726 int err = PTR_ERR(t);
2727
2728 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2729 err);
2730 return err;
2731 }
2732 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2733 return 0;
2734 }
2735
2736 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2737 {
2738 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2739
2740 while (sci->sc_task) {
2741 wake_up(&sci->sc_wait_daemon);
2742 spin_unlock(&sci->sc_state_lock);
2743 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2744 spin_lock(&sci->sc_state_lock);
2745 }
2746 }
2747
2748 static int nilfs_segctor_init(struct nilfs_sc_info *sci)
2749 {
2750 sci->sc_seq_done = sci->sc_seq_request;
2751
2752 return nilfs_segctor_start_thread(sci);
2753 }
2754
2755 /*
2756 * Setup & clean-up functions
2757 */
2758 static struct nilfs_sc_info *nilfs_segctor_new(struct nilfs_sb_info *sbi)
2759 {
2760 struct nilfs_sc_info *sci;
2761
2762 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2763 if (!sci)
2764 return NULL;
2765
2766 sci->sc_sbi = sbi;
2767 sci->sc_super = sbi->s_super;
2768
2769 init_waitqueue_head(&sci->sc_wait_request);
2770 init_waitqueue_head(&sci->sc_wait_daemon);
2771 init_waitqueue_head(&sci->sc_wait_task);
2772 spin_lock_init(&sci->sc_state_lock);
2773 INIT_LIST_HEAD(&sci->sc_dirty_files);
2774 INIT_LIST_HEAD(&sci->sc_segbufs);
2775 INIT_LIST_HEAD(&sci->sc_write_logs);
2776 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2777 INIT_LIST_HEAD(&sci->sc_copied_buffers);
2778
2779 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2780 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2781 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2782
2783 if (sbi->s_interval)
2784 sci->sc_interval = sbi->s_interval;
2785 if (sbi->s_watermark)
2786 sci->sc_watermark = sbi->s_watermark;
2787 return sci;
2788 }
2789
2790 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2791 {
2792 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2793
2794 /* The segctord thread was stopped and its timer was removed.
2795 But some tasks remain. */
2796 do {
2797 struct nilfs_sb_info *sbi = sci->sc_sbi;
2798 struct nilfs_transaction_info ti;
2799 struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
2800
2801 nilfs_transaction_lock(sbi, &ti, 0);
2802 nilfs_segctor_accept(sci, &req);
2803 ret = nilfs_segctor_construct(sci, &req);
2804 nilfs_segctor_notify(sci, &req);
2805 nilfs_transaction_unlock(sbi);
2806
2807 } while (ret && retrycount-- > 0);
2808 }
2809
2810 /**
2811 * nilfs_segctor_destroy - destroy the segment constructor.
2812 * @sci: nilfs_sc_info
2813 *
2814 * nilfs_segctor_destroy() kills the segctord thread and frees
2815 * the nilfs_sc_info struct.
2816 * Caller must hold the segment semaphore.
2817 */
2818 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2819 {
2820 struct nilfs_sb_info *sbi = sci->sc_sbi;
2821 int flag;
2822
2823 up_write(&sbi->s_nilfs->ns_segctor_sem);
2824
2825 spin_lock(&sci->sc_state_lock);
2826 nilfs_segctor_kill_thread(sci);
2827 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2828 || sci->sc_seq_request != sci->sc_seq_done);
2829 spin_unlock(&sci->sc_state_lock);
2830
2831 if (flag || !nilfs_segctor_confirm(sci))
2832 nilfs_segctor_write_out(sci);
2833
2834 WARN_ON(!list_empty(&sci->sc_copied_buffers));
2835
2836 if (!list_empty(&sci->sc_dirty_files)) {
2837 nilfs_warning(sbi->s_super, __func__,
2838 "dirty file(s) after the final construction\n");
2839 nilfs_dispose_list(sbi, &sci->sc_dirty_files, 1);
2840 }
2841
2842 WARN_ON(!list_empty(&sci->sc_segbufs));
2843 WARN_ON(!list_empty(&sci->sc_write_logs));
2844
2845 down_write(&sbi->s_nilfs->ns_segctor_sem);
2846
2847 kfree(sci);
2848 }
2849
2850 /**
2851 * nilfs_attach_segment_constructor - attach a segment constructor
2852 * @sbi: nilfs_sb_info
2853 *
2854 * nilfs_attach_segment_constructor() allocates a struct nilfs_sc_info,
2855 * initilizes it, and starts the segment constructor.
2856 *
2857 * Return Value: On success, 0 is returned. On error, one of the following
2858 * negative error code is returned.
2859 *
2860 * %-ENOMEM - Insufficient memory available.
2861 */
2862 int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi)
2863 {
2864 struct the_nilfs *nilfs = sbi->s_nilfs;
2865 int err;
2866
2867 /* Each field of nilfs_segctor is cleared through the initialization
2868 of super-block info */
2869 sbi->s_sc_info = nilfs_segctor_new(sbi);
2870 if (!sbi->s_sc_info)
2871 return -ENOMEM;
2872
2873 nilfs_attach_writer(nilfs, sbi);
2874 err = nilfs_segctor_init(NILFS_SC(sbi));
2875 if (err) {
2876 nilfs_detach_writer(nilfs, sbi);
2877 kfree(sbi->s_sc_info);
2878 sbi->s_sc_info = NULL;
2879 }
2880 return err;
2881 }
2882
2883 /**
2884 * nilfs_detach_segment_constructor - destroy the segment constructor
2885 * @sbi: nilfs_sb_info
2886 *
2887 * nilfs_detach_segment_constructor() kills the segment constructor daemon,
2888 * frees the struct nilfs_sc_info, and destroy the dirty file list.
2889 */
2890 void nilfs_detach_segment_constructor(struct nilfs_sb_info *sbi)
2891 {
2892 struct the_nilfs *nilfs = sbi->s_nilfs;
2893 LIST_HEAD(garbage_list);
2894
2895 down_write(&nilfs->ns_segctor_sem);
2896 if (NILFS_SC(sbi)) {
2897 nilfs_segctor_destroy(NILFS_SC(sbi));
2898 sbi->s_sc_info = NULL;
2899 }
2900
2901 /* Force to free the list of dirty files */
2902 spin_lock(&sbi->s_inode_lock);
2903 if (!list_empty(&sbi->s_dirty_files)) {
2904 list_splice_init(&sbi->s_dirty_files, &garbage_list);
2905 nilfs_warning(sbi->s_super, __func__,
2906 "Non empty dirty list after the last "
2907 "segment construction\n");
2908 }
2909 spin_unlock(&sbi->s_inode_lock);
2910 up_write(&nilfs->ns_segctor_sem);
2911
2912 nilfs_dispose_list(sbi, &garbage_list, 1);
2913 nilfs_detach_writer(nilfs, sbi);
2914 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree