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[karo-tx-linux.git] / fs / nilfs2 / sufile.c
1 /*
2  * sufile.c - NILFS segment usage file.
3  *
4  * Copyright (C) 2006-2008 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  * Written by Koji Sato.
17  * Revised by Ryusuke Konishi.
18  */
19
20 #include <linux/kernel.h>
21 #include <linux/fs.h>
22 #include <linux/string.h>
23 #include <linux/buffer_head.h>
24 #include <linux/errno.h>
25 #include "mdt.h"
26 #include "sufile.h"
27
28 #include <trace/events/nilfs2.h>
29
30 /**
31  * struct nilfs_sufile_info - on-memory private data of sufile
32  * @mi: on-memory private data of metadata file
33  * @ncleansegs: number of clean segments
34  * @allocmin: lower limit of allocatable segment range
35  * @allocmax: upper limit of allocatable segment range
36  */
37 struct nilfs_sufile_info {
38         struct nilfs_mdt_info mi;
39         unsigned long ncleansegs;/* number of clean segments */
40         __u64 allocmin;         /* lower limit of allocatable segment range */
41         __u64 allocmax;         /* upper limit of allocatable segment range */
42 };
43
44 static inline struct nilfs_sufile_info *NILFS_SUI(struct inode *sufile)
45 {
46         return (struct nilfs_sufile_info *)NILFS_MDT(sufile);
47 }
48
49 static inline unsigned long
50 nilfs_sufile_segment_usages_per_block(const struct inode *sufile)
51 {
52         return NILFS_MDT(sufile)->mi_entries_per_block;
53 }
54
55 static unsigned long
56 nilfs_sufile_get_blkoff(const struct inode *sufile, __u64 segnum)
57 {
58         __u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
59
60         do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
61         return (unsigned long)t;
62 }
63
64 static unsigned long
65 nilfs_sufile_get_offset(const struct inode *sufile, __u64 segnum)
66 {
67         __u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
68
69         return do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
70 }
71
72 static unsigned long
73 nilfs_sufile_segment_usages_in_block(const struct inode *sufile, __u64 curr,
74                                      __u64 max)
75 {
76         return min_t(unsigned long,
77                      nilfs_sufile_segment_usages_per_block(sufile) -
78                      nilfs_sufile_get_offset(sufile, curr),
79                      max - curr + 1);
80 }
81
82 static struct nilfs_segment_usage *
83 nilfs_sufile_block_get_segment_usage(const struct inode *sufile, __u64 segnum,
84                                      struct buffer_head *bh, void *kaddr)
85 {
86         return kaddr + bh_offset(bh) +
87                 nilfs_sufile_get_offset(sufile, segnum) *
88                 NILFS_MDT(sufile)->mi_entry_size;
89 }
90
91 static inline int nilfs_sufile_get_header_block(struct inode *sufile,
92                                                 struct buffer_head **bhp)
93 {
94         return nilfs_mdt_get_block(sufile, 0, 0, NULL, bhp);
95 }
96
97 static inline int
98 nilfs_sufile_get_segment_usage_block(struct inode *sufile, __u64 segnum,
99                                      int create, struct buffer_head **bhp)
100 {
101         return nilfs_mdt_get_block(sufile,
102                                    nilfs_sufile_get_blkoff(sufile, segnum),
103                                    create, NULL, bhp);
104 }
105
106 static int nilfs_sufile_delete_segment_usage_block(struct inode *sufile,
107                                                    __u64 segnum)
108 {
109         return nilfs_mdt_delete_block(sufile,
110                                       nilfs_sufile_get_blkoff(sufile, segnum));
111 }
112
113 static void nilfs_sufile_mod_counter(struct buffer_head *header_bh,
114                                      u64 ncleanadd, u64 ndirtyadd)
115 {
116         struct nilfs_sufile_header *header;
117         void *kaddr;
118
119         kaddr = kmap_atomic(header_bh->b_page);
120         header = kaddr + bh_offset(header_bh);
121         le64_add_cpu(&header->sh_ncleansegs, ncleanadd);
122         le64_add_cpu(&header->sh_ndirtysegs, ndirtyadd);
123         kunmap_atomic(kaddr);
124
125         mark_buffer_dirty(header_bh);
126 }
127
128 /**
129  * nilfs_sufile_get_ncleansegs - return the number of clean segments
130  * @sufile: inode of segment usage file
131  */
132 unsigned long nilfs_sufile_get_ncleansegs(struct inode *sufile)
133 {
134         return NILFS_SUI(sufile)->ncleansegs;
135 }
136
137 /**
138  * nilfs_sufile_updatev - modify multiple segment usages at a time
139  * @sufile: inode of segment usage file
140  * @segnumv: array of segment numbers
141  * @nsegs: size of @segnumv array
142  * @create: creation flag
143  * @ndone: place to store number of modified segments on @segnumv
144  * @dofunc: primitive operation for the update
145  *
146  * Description: nilfs_sufile_updatev() repeatedly calls @dofunc
147  * against the given array of segments.  The @dofunc is called with
148  * buffers of a header block and the sufile block in which the target
149  * segment usage entry is contained.  If @ndone is given, the number
150  * of successfully modified segments from the head is stored in the
151  * place @ndone points to.
152  *
153  * Return Value: On success, zero is returned.  On error, one of the
154  * following negative error codes is returned.
155  *
156  * %-EIO - I/O error.
157  *
158  * %-ENOMEM - Insufficient amount of memory available.
159  *
160  * %-ENOENT - Given segment usage is in hole block (may be returned if
161  *            @create is zero)
162  *
163  * %-EINVAL - Invalid segment usage number
164  */
165 int nilfs_sufile_updatev(struct inode *sufile, __u64 *segnumv, size_t nsegs,
166                          int create, size_t *ndone,
167                          void (*dofunc)(struct inode *, __u64,
168                                         struct buffer_head *,
169                                         struct buffer_head *))
170 {
171         struct buffer_head *header_bh, *bh;
172         unsigned long blkoff, prev_blkoff;
173         __u64 *seg;
174         size_t nerr = 0, n = 0;
175         int ret = 0;
176
177         if (unlikely(nsegs == 0))
178                 goto out;
179
180         down_write(&NILFS_MDT(sufile)->mi_sem);
181         for (seg = segnumv; seg < segnumv + nsegs; seg++) {
182                 if (unlikely(*seg >= nilfs_sufile_get_nsegments(sufile))) {
183                         nilfs_msg(sufile->i_sb, KERN_WARNING,
184                                   "%s: invalid segment number: %llu",
185                                   __func__, (unsigned long long)*seg);
186                         nerr++;
187                 }
188         }
189         if (nerr > 0) {
190                 ret = -EINVAL;
191                 goto out_sem;
192         }
193
194         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
195         if (ret < 0)
196                 goto out_sem;
197
198         seg = segnumv;
199         blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
200         ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
201         if (ret < 0)
202                 goto out_header;
203
204         for (;;) {
205                 dofunc(sufile, *seg, header_bh, bh);
206
207                 if (++seg >= segnumv + nsegs)
208                         break;
209                 prev_blkoff = blkoff;
210                 blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
211                 if (blkoff == prev_blkoff)
212                         continue;
213
214                 /* get different block */
215                 brelse(bh);
216                 ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
217                 if (unlikely(ret < 0))
218                         goto out_header;
219         }
220         brelse(bh);
221
222  out_header:
223         n = seg - segnumv;
224         brelse(header_bh);
225  out_sem:
226         up_write(&NILFS_MDT(sufile)->mi_sem);
227  out:
228         if (ndone)
229                 *ndone = n;
230         return ret;
231 }
232
233 int nilfs_sufile_update(struct inode *sufile, __u64 segnum, int create,
234                         void (*dofunc)(struct inode *, __u64,
235                                        struct buffer_head *,
236                                        struct buffer_head *))
237 {
238         struct buffer_head *header_bh, *bh;
239         int ret;
240
241         if (unlikely(segnum >= nilfs_sufile_get_nsegments(sufile))) {
242                 nilfs_msg(sufile->i_sb, KERN_WARNING,
243                           "%s: invalid segment number: %llu",
244                           __func__, (unsigned long long)segnum);
245                 return -EINVAL;
246         }
247         down_write(&NILFS_MDT(sufile)->mi_sem);
248
249         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
250         if (ret < 0)
251                 goto out_sem;
252
253         ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, create, &bh);
254         if (!ret) {
255                 dofunc(sufile, segnum, header_bh, bh);
256                 brelse(bh);
257         }
258         brelse(header_bh);
259
260  out_sem:
261         up_write(&NILFS_MDT(sufile)->mi_sem);
262         return ret;
263 }
264
265 /**
266  * nilfs_sufile_set_alloc_range - limit range of segment to be allocated
267  * @sufile: inode of segment usage file
268  * @start: minimum segment number of allocatable region (inclusive)
269  * @end: maximum segment number of allocatable region (inclusive)
270  *
271  * Return Value: On success, 0 is returned.  On error, one of the
272  * following negative error codes is returned.
273  *
274  * %-ERANGE - invalid segment region
275  */
276 int nilfs_sufile_set_alloc_range(struct inode *sufile, __u64 start, __u64 end)
277 {
278         struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
279         __u64 nsegs;
280         int ret = -ERANGE;
281
282         down_write(&NILFS_MDT(sufile)->mi_sem);
283         nsegs = nilfs_sufile_get_nsegments(sufile);
284
285         if (start <= end && end < nsegs) {
286                 sui->allocmin = start;
287                 sui->allocmax = end;
288                 ret = 0;
289         }
290         up_write(&NILFS_MDT(sufile)->mi_sem);
291         return ret;
292 }
293
294 /**
295  * nilfs_sufile_alloc - allocate a segment
296  * @sufile: inode of segment usage file
297  * @segnump: pointer to segment number
298  *
299  * Description: nilfs_sufile_alloc() allocates a clean segment.
300  *
301  * Return Value: On success, 0 is returned and the segment number of the
302  * allocated segment is stored in the place pointed by @segnump. On error, one
303  * of the following negative error codes is returned.
304  *
305  * %-EIO - I/O error.
306  *
307  * %-ENOMEM - Insufficient amount of memory available.
308  *
309  * %-ENOSPC - No clean segment left.
310  */
311 int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
312 {
313         struct buffer_head *header_bh, *su_bh;
314         struct nilfs_sufile_header *header;
315         struct nilfs_segment_usage *su;
316         struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
317         size_t susz = NILFS_MDT(sufile)->mi_entry_size;
318         __u64 segnum, maxsegnum, last_alloc;
319         void *kaddr;
320         unsigned long nsegments, nsus, cnt;
321         int ret, j;
322
323         down_write(&NILFS_MDT(sufile)->mi_sem);
324
325         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
326         if (ret < 0)
327                 goto out_sem;
328         kaddr = kmap_atomic(header_bh->b_page);
329         header = kaddr + bh_offset(header_bh);
330         last_alloc = le64_to_cpu(header->sh_last_alloc);
331         kunmap_atomic(kaddr);
332
333         nsegments = nilfs_sufile_get_nsegments(sufile);
334         maxsegnum = sui->allocmax;
335         segnum = last_alloc + 1;
336         if (segnum < sui->allocmin || segnum > sui->allocmax)
337                 segnum = sui->allocmin;
338
339         for (cnt = 0; cnt < nsegments; cnt += nsus) {
340                 if (segnum > maxsegnum) {
341                         if (cnt < sui->allocmax - sui->allocmin + 1) {
342                                 /*
343                                  * wrap around in the limited region.
344                                  * if allocation started from
345                                  * sui->allocmin, this never happens.
346                                  */
347                                 segnum = sui->allocmin;
348                                 maxsegnum = last_alloc;
349                         } else if (segnum > sui->allocmin &&
350                                    sui->allocmax + 1 < nsegments) {
351                                 segnum = sui->allocmax + 1;
352                                 maxsegnum = nsegments - 1;
353                         } else if (sui->allocmin > 0)  {
354                                 segnum = 0;
355                                 maxsegnum = sui->allocmin - 1;
356                         } else {
357                                 break; /* never happens */
358                         }
359                 }
360                 trace_nilfs2_segment_usage_check(sufile, segnum, cnt);
361                 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
362                                                            &su_bh);
363                 if (ret < 0)
364                         goto out_header;
365                 kaddr = kmap_atomic(su_bh->b_page);
366                 su = nilfs_sufile_block_get_segment_usage(
367                         sufile, segnum, su_bh, kaddr);
368
369                 nsus = nilfs_sufile_segment_usages_in_block(
370                         sufile, segnum, maxsegnum);
371                 for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) {
372                         if (!nilfs_segment_usage_clean(su))
373                                 continue;
374                         /* found a clean segment */
375                         nilfs_segment_usage_set_dirty(su);
376                         kunmap_atomic(kaddr);
377
378                         kaddr = kmap_atomic(header_bh->b_page);
379                         header = kaddr + bh_offset(header_bh);
380                         le64_add_cpu(&header->sh_ncleansegs, -1);
381                         le64_add_cpu(&header->sh_ndirtysegs, 1);
382                         header->sh_last_alloc = cpu_to_le64(segnum);
383                         kunmap_atomic(kaddr);
384
385                         sui->ncleansegs--;
386                         mark_buffer_dirty(header_bh);
387                         mark_buffer_dirty(su_bh);
388                         nilfs_mdt_mark_dirty(sufile);
389                         brelse(su_bh);
390                         *segnump = segnum;
391
392                         trace_nilfs2_segment_usage_allocated(sufile, segnum);
393
394                         goto out_header;
395                 }
396
397                 kunmap_atomic(kaddr);
398                 brelse(su_bh);
399         }
400
401         /* no segments left */
402         ret = -ENOSPC;
403
404  out_header:
405         brelse(header_bh);
406
407  out_sem:
408         up_write(&NILFS_MDT(sufile)->mi_sem);
409         return ret;
410 }
411
412 void nilfs_sufile_do_cancel_free(struct inode *sufile, __u64 segnum,
413                                  struct buffer_head *header_bh,
414                                  struct buffer_head *su_bh)
415 {
416         struct nilfs_segment_usage *su;
417         void *kaddr;
418
419         kaddr = kmap_atomic(su_bh->b_page);
420         su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
421         if (unlikely(!nilfs_segment_usage_clean(su))) {
422                 nilfs_msg(sufile->i_sb, KERN_WARNING,
423                           "%s: segment %llu must be clean", __func__,
424                           (unsigned long long)segnum);
425                 kunmap_atomic(kaddr);
426                 return;
427         }
428         nilfs_segment_usage_set_dirty(su);
429         kunmap_atomic(kaddr);
430
431         nilfs_sufile_mod_counter(header_bh, -1, 1);
432         NILFS_SUI(sufile)->ncleansegs--;
433
434         mark_buffer_dirty(su_bh);
435         nilfs_mdt_mark_dirty(sufile);
436 }
437
438 void nilfs_sufile_do_scrap(struct inode *sufile, __u64 segnum,
439                            struct buffer_head *header_bh,
440                            struct buffer_head *su_bh)
441 {
442         struct nilfs_segment_usage *su;
443         void *kaddr;
444         int clean, dirty;
445
446         kaddr = kmap_atomic(su_bh->b_page);
447         su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
448         if (su->su_flags == cpu_to_le32(BIT(NILFS_SEGMENT_USAGE_DIRTY)) &&
449             su->su_nblocks == cpu_to_le32(0)) {
450                 kunmap_atomic(kaddr);
451                 return;
452         }
453         clean = nilfs_segment_usage_clean(su);
454         dirty = nilfs_segment_usage_dirty(su);
455
456         /* make the segment garbage */
457         su->su_lastmod = cpu_to_le64(0);
458         su->su_nblocks = cpu_to_le32(0);
459         su->su_flags = cpu_to_le32(BIT(NILFS_SEGMENT_USAGE_DIRTY));
460         kunmap_atomic(kaddr);
461
462         nilfs_sufile_mod_counter(header_bh, clean ? (u64)-1 : 0, dirty ? 0 : 1);
463         NILFS_SUI(sufile)->ncleansegs -= clean;
464
465         mark_buffer_dirty(su_bh);
466         nilfs_mdt_mark_dirty(sufile);
467 }
468
469 void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
470                           struct buffer_head *header_bh,
471                           struct buffer_head *su_bh)
472 {
473         struct nilfs_segment_usage *su;
474         void *kaddr;
475         int sudirty;
476
477         kaddr = kmap_atomic(su_bh->b_page);
478         su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
479         if (nilfs_segment_usage_clean(su)) {
480                 nilfs_msg(sufile->i_sb, KERN_WARNING,
481                           "%s: segment %llu is already clean",
482                           __func__, (unsigned long long)segnum);
483                 kunmap_atomic(kaddr);
484                 return;
485         }
486         WARN_ON(nilfs_segment_usage_error(su));
487         WARN_ON(!nilfs_segment_usage_dirty(su));
488
489         sudirty = nilfs_segment_usage_dirty(su);
490         nilfs_segment_usage_set_clean(su);
491         kunmap_atomic(kaddr);
492         mark_buffer_dirty(su_bh);
493
494         nilfs_sufile_mod_counter(header_bh, 1, sudirty ? (u64)-1 : 0);
495         NILFS_SUI(sufile)->ncleansegs++;
496
497         nilfs_mdt_mark_dirty(sufile);
498
499         trace_nilfs2_segment_usage_freed(sufile, segnum);
500 }
501
502 /**
503  * nilfs_sufile_mark_dirty - mark the buffer having a segment usage dirty
504  * @sufile: inode of segment usage file
505  * @segnum: segment number
506  */
507 int nilfs_sufile_mark_dirty(struct inode *sufile, __u64 segnum)
508 {
509         struct buffer_head *bh;
510         int ret;
511
512         ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
513         if (!ret) {
514                 mark_buffer_dirty(bh);
515                 nilfs_mdt_mark_dirty(sufile);
516                 brelse(bh);
517         }
518         return ret;
519 }
520
521 /**
522  * nilfs_sufile_set_segment_usage - set usage of a segment
523  * @sufile: inode of segment usage file
524  * @segnum: segment number
525  * @nblocks: number of live blocks in the segment
526  * @modtime: modification time (option)
527  */
528 int nilfs_sufile_set_segment_usage(struct inode *sufile, __u64 segnum,
529                                    unsigned long nblocks, time_t modtime)
530 {
531         struct buffer_head *bh;
532         struct nilfs_segment_usage *su;
533         void *kaddr;
534         int ret;
535
536         down_write(&NILFS_MDT(sufile)->mi_sem);
537         ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
538         if (ret < 0)
539                 goto out_sem;
540
541         kaddr = kmap_atomic(bh->b_page);
542         su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
543         WARN_ON(nilfs_segment_usage_error(su));
544         if (modtime)
545                 su->su_lastmod = cpu_to_le64(modtime);
546         su->su_nblocks = cpu_to_le32(nblocks);
547         kunmap_atomic(kaddr);
548
549         mark_buffer_dirty(bh);
550         nilfs_mdt_mark_dirty(sufile);
551         brelse(bh);
552
553  out_sem:
554         up_write(&NILFS_MDT(sufile)->mi_sem);
555         return ret;
556 }
557
558 /**
559  * nilfs_sufile_get_stat - get segment usage statistics
560  * @sufile: inode of segment usage file
561  * @stat: pointer to a structure of segment usage statistics
562  *
563  * Description: nilfs_sufile_get_stat() returns information about segment
564  * usage.
565  *
566  * Return Value: On success, 0 is returned, and segment usage information is
567  * stored in the place pointed by @stat. On error, one of the following
568  * negative error codes is returned.
569  *
570  * %-EIO - I/O error.
571  *
572  * %-ENOMEM - Insufficient amount of memory available.
573  */
574 int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
575 {
576         struct buffer_head *header_bh;
577         struct nilfs_sufile_header *header;
578         struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
579         void *kaddr;
580         int ret;
581
582         down_read(&NILFS_MDT(sufile)->mi_sem);
583
584         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
585         if (ret < 0)
586                 goto out_sem;
587
588         kaddr = kmap_atomic(header_bh->b_page);
589         header = kaddr + bh_offset(header_bh);
590         sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile);
591         sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs);
592         sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs);
593         sustat->ss_ctime = nilfs->ns_ctime;
594         sustat->ss_nongc_ctime = nilfs->ns_nongc_ctime;
595         spin_lock(&nilfs->ns_last_segment_lock);
596         sustat->ss_prot_seq = nilfs->ns_prot_seq;
597         spin_unlock(&nilfs->ns_last_segment_lock);
598         kunmap_atomic(kaddr);
599         brelse(header_bh);
600
601  out_sem:
602         up_read(&NILFS_MDT(sufile)->mi_sem);
603         return ret;
604 }
605
606 void nilfs_sufile_do_set_error(struct inode *sufile, __u64 segnum,
607                                struct buffer_head *header_bh,
608                                struct buffer_head *su_bh)
609 {
610         struct nilfs_segment_usage *su;
611         void *kaddr;
612         int suclean;
613
614         kaddr = kmap_atomic(su_bh->b_page);
615         su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
616         if (nilfs_segment_usage_error(su)) {
617                 kunmap_atomic(kaddr);
618                 return;
619         }
620         suclean = nilfs_segment_usage_clean(su);
621         nilfs_segment_usage_set_error(su);
622         kunmap_atomic(kaddr);
623
624         if (suclean) {
625                 nilfs_sufile_mod_counter(header_bh, -1, 0);
626                 NILFS_SUI(sufile)->ncleansegs--;
627         }
628         mark_buffer_dirty(su_bh);
629         nilfs_mdt_mark_dirty(sufile);
630 }
631
632 /**
633   * nilfs_sufile_truncate_range - truncate range of segment array
634   * @sufile: inode of segment usage file
635   * @start: start segment number (inclusive)
636   * @end: end segment number (inclusive)
637   *
638   * Return Value: On success, 0 is returned.  On error, one of the
639   * following negative error codes is returned.
640   *
641   * %-EIO - I/O error.
642   *
643   * %-ENOMEM - Insufficient amount of memory available.
644   *
645   * %-EINVAL - Invalid number of segments specified
646   *
647   * %-EBUSY - Dirty or active segments are present in the range
648   */
649 static int nilfs_sufile_truncate_range(struct inode *sufile,
650                                        __u64 start, __u64 end)
651 {
652         struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
653         struct buffer_head *header_bh;
654         struct buffer_head *su_bh;
655         struct nilfs_segment_usage *su, *su2;
656         size_t susz = NILFS_MDT(sufile)->mi_entry_size;
657         unsigned long segusages_per_block;
658         unsigned long nsegs, ncleaned;
659         __u64 segnum;
660         void *kaddr;
661         ssize_t n, nc;
662         int ret;
663         int j;
664
665         nsegs = nilfs_sufile_get_nsegments(sufile);
666
667         ret = -EINVAL;
668         if (start > end || start >= nsegs)
669                 goto out;
670
671         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
672         if (ret < 0)
673                 goto out;
674
675         segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
676         ncleaned = 0;
677
678         for (segnum = start; segnum <= end; segnum += n) {
679                 n = min_t(unsigned long,
680                           segusages_per_block -
681                                   nilfs_sufile_get_offset(sufile, segnum),
682                           end - segnum + 1);
683                 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
684                                                            &su_bh);
685                 if (ret < 0) {
686                         if (ret != -ENOENT)
687                                 goto out_header;
688                         /* hole */
689                         continue;
690                 }
691                 kaddr = kmap_atomic(su_bh->b_page);
692                 su = nilfs_sufile_block_get_segment_usage(
693                         sufile, segnum, su_bh, kaddr);
694                 su2 = su;
695                 for (j = 0; j < n; j++, su = (void *)su + susz) {
696                         if ((le32_to_cpu(su->su_flags) &
697                              ~BIT(NILFS_SEGMENT_USAGE_ERROR)) ||
698                             nilfs_segment_is_active(nilfs, segnum + j)) {
699                                 ret = -EBUSY;
700                                 kunmap_atomic(kaddr);
701                                 brelse(su_bh);
702                                 goto out_header;
703                         }
704                 }
705                 nc = 0;
706                 for (su = su2, j = 0; j < n; j++, su = (void *)su + susz) {
707                         if (nilfs_segment_usage_error(su)) {
708                                 nilfs_segment_usage_set_clean(su);
709                                 nc++;
710                         }
711                 }
712                 kunmap_atomic(kaddr);
713                 if (nc > 0) {
714                         mark_buffer_dirty(su_bh);
715                         ncleaned += nc;
716                 }
717                 brelse(su_bh);
718
719                 if (n == segusages_per_block) {
720                         /* make hole */
721                         nilfs_sufile_delete_segment_usage_block(sufile, segnum);
722                 }
723         }
724         ret = 0;
725
726 out_header:
727         if (ncleaned > 0) {
728                 NILFS_SUI(sufile)->ncleansegs += ncleaned;
729                 nilfs_sufile_mod_counter(header_bh, ncleaned, 0);
730                 nilfs_mdt_mark_dirty(sufile);
731         }
732         brelse(header_bh);
733 out:
734         return ret;
735 }
736
737 /**
738  * nilfs_sufile_resize - resize segment array
739  * @sufile: inode of segment usage file
740  * @newnsegs: new number of segments
741  *
742  * Return Value: On success, 0 is returned.  On error, one of the
743  * following negative error codes is returned.
744  *
745  * %-EIO - I/O error.
746  *
747  * %-ENOMEM - Insufficient amount of memory available.
748  *
749  * %-ENOSPC - Enough free space is not left for shrinking
750  *
751  * %-EBUSY - Dirty or active segments exist in the region to be truncated
752  */
753 int nilfs_sufile_resize(struct inode *sufile, __u64 newnsegs)
754 {
755         struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
756         struct buffer_head *header_bh;
757         struct nilfs_sufile_header *header;
758         struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
759         void *kaddr;
760         unsigned long nsegs, nrsvsegs;
761         int ret = 0;
762
763         down_write(&NILFS_MDT(sufile)->mi_sem);
764
765         nsegs = nilfs_sufile_get_nsegments(sufile);
766         if (nsegs == newnsegs)
767                 goto out;
768
769         ret = -ENOSPC;
770         nrsvsegs = nilfs_nrsvsegs(nilfs, newnsegs);
771         if (newnsegs < nsegs && nsegs - newnsegs + nrsvsegs > sui->ncleansegs)
772                 goto out;
773
774         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
775         if (ret < 0)
776                 goto out;
777
778         if (newnsegs > nsegs) {
779                 sui->ncleansegs += newnsegs - nsegs;
780         } else /* newnsegs < nsegs */ {
781                 ret = nilfs_sufile_truncate_range(sufile, newnsegs, nsegs - 1);
782                 if (ret < 0)
783                         goto out_header;
784
785                 sui->ncleansegs -= nsegs - newnsegs;
786         }
787
788         kaddr = kmap_atomic(header_bh->b_page);
789         header = kaddr + bh_offset(header_bh);
790         header->sh_ncleansegs = cpu_to_le64(sui->ncleansegs);
791         kunmap_atomic(kaddr);
792
793         mark_buffer_dirty(header_bh);
794         nilfs_mdt_mark_dirty(sufile);
795         nilfs_set_nsegments(nilfs, newnsegs);
796
797 out_header:
798         brelse(header_bh);
799 out:
800         up_write(&NILFS_MDT(sufile)->mi_sem);
801         return ret;
802 }
803
804 /**
805  * nilfs_sufile_get_suinfo -
806  * @sufile: inode of segment usage file
807  * @segnum: segment number to start looking
808  * @buf: array of suinfo
809  * @sisz: byte size of suinfo
810  * @nsi: size of suinfo array
811  *
812  * Description:
813  *
814  * Return Value: On success, 0 is returned and .... On error, one of the
815  * following negative error codes is returned.
816  *
817  * %-EIO - I/O error.
818  *
819  * %-ENOMEM - Insufficient amount of memory available.
820  */
821 ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum, void *buf,
822                                 unsigned int sisz, size_t nsi)
823 {
824         struct buffer_head *su_bh;
825         struct nilfs_segment_usage *su;
826         struct nilfs_suinfo *si = buf;
827         size_t susz = NILFS_MDT(sufile)->mi_entry_size;
828         struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
829         void *kaddr;
830         unsigned long nsegs, segusages_per_block;
831         ssize_t n;
832         int ret, i, j;
833
834         down_read(&NILFS_MDT(sufile)->mi_sem);
835
836         segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
837         nsegs = min_t(unsigned long,
838                       nilfs_sufile_get_nsegments(sufile) - segnum,
839                       nsi);
840         for (i = 0; i < nsegs; i += n, segnum += n) {
841                 n = min_t(unsigned long,
842                           segusages_per_block -
843                                   nilfs_sufile_get_offset(sufile, segnum),
844                           nsegs - i);
845                 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
846                                                            &su_bh);
847                 if (ret < 0) {
848                         if (ret != -ENOENT)
849                                 goto out;
850                         /* hole */
851                         memset(si, 0, sisz * n);
852                         si = (void *)si + sisz * n;
853                         continue;
854                 }
855
856                 kaddr = kmap_atomic(su_bh->b_page);
857                 su = nilfs_sufile_block_get_segment_usage(
858                         sufile, segnum, su_bh, kaddr);
859                 for (j = 0; j < n;
860                      j++, su = (void *)su + susz, si = (void *)si + sisz) {
861                         si->sui_lastmod = le64_to_cpu(su->su_lastmod);
862                         si->sui_nblocks = le32_to_cpu(su->su_nblocks);
863                         si->sui_flags = le32_to_cpu(su->su_flags) &
864                                 ~BIT(NILFS_SEGMENT_USAGE_ACTIVE);
865                         if (nilfs_segment_is_active(nilfs, segnum + j))
866                                 si->sui_flags |=
867                                         BIT(NILFS_SEGMENT_USAGE_ACTIVE);
868                 }
869                 kunmap_atomic(kaddr);
870                 brelse(su_bh);
871         }
872         ret = nsegs;
873
874  out:
875         up_read(&NILFS_MDT(sufile)->mi_sem);
876         return ret;
877 }
878
879 /**
880  * nilfs_sufile_set_suinfo - sets segment usage info
881  * @sufile: inode of segment usage file
882  * @buf: array of suinfo_update
883  * @supsz: byte size of suinfo_update
884  * @nsup: size of suinfo_update array
885  *
886  * Description: Takes an array of nilfs_suinfo_update structs and updates
887  * segment usage accordingly. Only the fields indicated by the sup_flags
888  * are updated.
889  *
890  * Return Value: On success, 0 is returned. On error, one of the
891  * following negative error codes is returned.
892  *
893  * %-EIO - I/O error.
894  *
895  * %-ENOMEM - Insufficient amount of memory available.
896  *
897  * %-EINVAL - Invalid values in input (segment number, flags or nblocks)
898  */
899 ssize_t nilfs_sufile_set_suinfo(struct inode *sufile, void *buf,
900                                 unsigned int supsz, size_t nsup)
901 {
902         struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
903         struct buffer_head *header_bh, *bh;
904         struct nilfs_suinfo_update *sup, *supend = buf + supsz * nsup;
905         struct nilfs_segment_usage *su;
906         void *kaddr;
907         unsigned long blkoff, prev_blkoff;
908         int cleansi, cleansu, dirtysi, dirtysu;
909         long ncleaned = 0, ndirtied = 0;
910         int ret = 0;
911
912         if (unlikely(nsup == 0))
913                 return ret;
914
915         for (sup = buf; sup < supend; sup = (void *)sup + supsz) {
916                 if (sup->sup_segnum >= nilfs->ns_nsegments
917                         || (sup->sup_flags &
918                                 (~0UL << __NR_NILFS_SUINFO_UPDATE_FIELDS))
919                         || (nilfs_suinfo_update_nblocks(sup) &&
920                                 sup->sup_sui.sui_nblocks >
921                                 nilfs->ns_blocks_per_segment))
922                         return -EINVAL;
923         }
924
925         down_write(&NILFS_MDT(sufile)->mi_sem);
926
927         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
928         if (ret < 0)
929                 goto out_sem;
930
931         sup = buf;
932         blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
933         ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
934         if (ret < 0)
935                 goto out_header;
936
937         for (;;) {
938                 kaddr = kmap_atomic(bh->b_page);
939                 su = nilfs_sufile_block_get_segment_usage(
940                         sufile, sup->sup_segnum, bh, kaddr);
941
942                 if (nilfs_suinfo_update_lastmod(sup))
943                         su->su_lastmod = cpu_to_le64(sup->sup_sui.sui_lastmod);
944
945                 if (nilfs_suinfo_update_nblocks(sup))
946                         su->su_nblocks = cpu_to_le32(sup->sup_sui.sui_nblocks);
947
948                 if (nilfs_suinfo_update_flags(sup)) {
949                         /*
950                          * Active flag is a virtual flag projected by running
951                          * nilfs kernel code - drop it not to write it to
952                          * disk.
953                          */
954                         sup->sup_sui.sui_flags &=
955                                         ~BIT(NILFS_SEGMENT_USAGE_ACTIVE);
956
957                         cleansi = nilfs_suinfo_clean(&sup->sup_sui);
958                         cleansu = nilfs_segment_usage_clean(su);
959                         dirtysi = nilfs_suinfo_dirty(&sup->sup_sui);
960                         dirtysu = nilfs_segment_usage_dirty(su);
961
962                         if (cleansi && !cleansu)
963                                 ++ncleaned;
964                         else if (!cleansi && cleansu)
965                                 --ncleaned;
966
967                         if (dirtysi && !dirtysu)
968                                 ++ndirtied;
969                         else if (!dirtysi && dirtysu)
970                                 --ndirtied;
971
972                         su->su_flags = cpu_to_le32(sup->sup_sui.sui_flags);
973                 }
974
975                 kunmap_atomic(kaddr);
976
977                 sup = (void *)sup + supsz;
978                 if (sup >= supend)
979                         break;
980
981                 prev_blkoff = blkoff;
982                 blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
983                 if (blkoff == prev_blkoff)
984                         continue;
985
986                 /* get different block */
987                 mark_buffer_dirty(bh);
988                 put_bh(bh);
989                 ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
990                 if (unlikely(ret < 0))
991                         goto out_mark;
992         }
993         mark_buffer_dirty(bh);
994         put_bh(bh);
995
996  out_mark:
997         if (ncleaned || ndirtied) {
998                 nilfs_sufile_mod_counter(header_bh, (u64)ncleaned,
999                                 (u64)ndirtied);
1000                 NILFS_SUI(sufile)->ncleansegs += ncleaned;
1001         }
1002         nilfs_mdt_mark_dirty(sufile);
1003  out_header:
1004         put_bh(header_bh);
1005  out_sem:
1006         up_write(&NILFS_MDT(sufile)->mi_sem);
1007         return ret;
1008 }
1009
1010 /**
1011  * nilfs_sufile_trim_fs() - trim ioctl handle function
1012  * @sufile: inode of segment usage file
1013  * @range: fstrim_range structure
1014  *
1015  * start:       First Byte to trim
1016  * len:         number of Bytes to trim from start
1017  * minlen:      minimum extent length in Bytes
1018  *
1019  * Decription: nilfs_sufile_trim_fs goes through all segments containing bytes
1020  * from start to start+len. start is rounded up to the next block boundary
1021  * and start+len is rounded down. For each clean segment blkdev_issue_discard
1022  * function is invoked.
1023  *
1024  * Return Value: On success, 0 is returned or negative error code, otherwise.
1025  */
1026 int nilfs_sufile_trim_fs(struct inode *sufile, struct fstrim_range *range)
1027 {
1028         struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
1029         struct buffer_head *su_bh;
1030         struct nilfs_segment_usage *su;
1031         void *kaddr;
1032         size_t n, i, susz = NILFS_MDT(sufile)->mi_entry_size;
1033         sector_t seg_start, seg_end, start_block, end_block;
1034         sector_t start = 0, nblocks = 0;
1035         u64 segnum, segnum_end, minlen, len, max_blocks, ndiscarded = 0;
1036         int ret = 0;
1037         unsigned int sects_per_block;
1038
1039         sects_per_block = (1 << nilfs->ns_blocksize_bits) /
1040                         bdev_logical_block_size(nilfs->ns_bdev);
1041         len = range->len >> nilfs->ns_blocksize_bits;
1042         minlen = range->minlen >> nilfs->ns_blocksize_bits;
1043         max_blocks = ((u64)nilfs->ns_nsegments * nilfs->ns_blocks_per_segment);
1044
1045         if (!len || range->start >= max_blocks << nilfs->ns_blocksize_bits)
1046                 return -EINVAL;
1047
1048         start_block = (range->start + nilfs->ns_blocksize - 1) >>
1049                         nilfs->ns_blocksize_bits;
1050
1051         /*
1052          * range->len can be very large (actually, it is set to
1053          * ULLONG_MAX by default) - truncate upper end of the range
1054          * carefully so as not to overflow.
1055          */
1056         if (max_blocks - start_block < len)
1057                 end_block = max_blocks - 1;
1058         else
1059                 end_block = start_block + len - 1;
1060
1061         segnum = nilfs_get_segnum_of_block(nilfs, start_block);
1062         segnum_end = nilfs_get_segnum_of_block(nilfs, end_block);
1063
1064         down_read(&NILFS_MDT(sufile)->mi_sem);
1065
1066         while (segnum <= segnum_end) {
1067                 n = nilfs_sufile_segment_usages_in_block(sufile, segnum,
1068                                 segnum_end);
1069
1070                 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
1071                                                            &su_bh);
1072                 if (ret < 0) {
1073                         if (ret != -ENOENT)
1074                                 goto out_sem;
1075                         /* hole */
1076                         segnum += n;
1077                         continue;
1078                 }
1079
1080                 kaddr = kmap_atomic(su_bh->b_page);
1081                 su = nilfs_sufile_block_get_segment_usage(sufile, segnum,
1082                                 su_bh, kaddr);
1083                 for (i = 0; i < n; ++i, ++segnum, su = (void *)su + susz) {
1084                         if (!nilfs_segment_usage_clean(su))
1085                                 continue;
1086
1087                         nilfs_get_segment_range(nilfs, segnum, &seg_start,
1088                                                 &seg_end);
1089
1090                         if (!nblocks) {
1091                                 /* start new extent */
1092                                 start = seg_start;
1093                                 nblocks = seg_end - seg_start + 1;
1094                                 continue;
1095                         }
1096
1097                         if (start + nblocks == seg_start) {
1098                                 /* add to previous extent */
1099                                 nblocks += seg_end - seg_start + 1;
1100                                 continue;
1101                         }
1102
1103                         /* discard previous extent */
1104                         if (start < start_block) {
1105                                 nblocks -= start_block - start;
1106                                 start = start_block;
1107                         }
1108
1109                         if (nblocks >= minlen) {
1110                                 kunmap_atomic(kaddr);
1111
1112                                 ret = blkdev_issue_discard(nilfs->ns_bdev,
1113                                                 start * sects_per_block,
1114                                                 nblocks * sects_per_block,
1115                                                 GFP_NOFS, 0);
1116                                 if (ret < 0) {
1117                                         put_bh(su_bh);
1118                                         goto out_sem;
1119                                 }
1120
1121                                 ndiscarded += nblocks;
1122                                 kaddr = kmap_atomic(su_bh->b_page);
1123                                 su = nilfs_sufile_block_get_segment_usage(
1124                                         sufile, segnum, su_bh, kaddr);
1125                         }
1126
1127                         /* start new extent */
1128                         start = seg_start;
1129                         nblocks = seg_end - seg_start + 1;
1130                 }
1131                 kunmap_atomic(kaddr);
1132                 put_bh(su_bh);
1133         }
1134
1135
1136         if (nblocks) {
1137                 /* discard last extent */
1138                 if (start < start_block) {
1139                         nblocks -= start_block - start;
1140                         start = start_block;
1141                 }
1142                 if (start + nblocks > end_block + 1)
1143                         nblocks = end_block - start + 1;
1144
1145                 if (nblocks >= minlen) {
1146                         ret = blkdev_issue_discard(nilfs->ns_bdev,
1147                                         start * sects_per_block,
1148                                         nblocks * sects_per_block,
1149                                         GFP_NOFS, 0);
1150                         if (!ret)
1151                                 ndiscarded += nblocks;
1152                 }
1153         }
1154
1155 out_sem:
1156         up_read(&NILFS_MDT(sufile)->mi_sem);
1157
1158         range->len = ndiscarded << nilfs->ns_blocksize_bits;
1159         return ret;
1160 }
1161
1162 /**
1163  * nilfs_sufile_read - read or get sufile inode
1164  * @sb: super block instance
1165  * @susize: size of a segment usage entry
1166  * @raw_inode: on-disk sufile inode
1167  * @inodep: buffer to store the inode
1168  */
1169 int nilfs_sufile_read(struct super_block *sb, size_t susize,
1170                       struct nilfs_inode *raw_inode, struct inode **inodep)
1171 {
1172         struct inode *sufile;
1173         struct nilfs_sufile_info *sui;
1174         struct buffer_head *header_bh;
1175         struct nilfs_sufile_header *header;
1176         void *kaddr;
1177         int err;
1178
1179         if (susize > sb->s_blocksize) {
1180                 nilfs_msg(sb, KERN_ERR,
1181                           "too large segment usage size: %zu bytes", susize);
1182                 return -EINVAL;
1183         } else if (susize < NILFS_MIN_SEGMENT_USAGE_SIZE) {
1184                 nilfs_msg(sb, KERN_ERR,
1185                           "too small segment usage size: %zu bytes", susize);
1186                 return -EINVAL;
1187         }
1188
1189         sufile = nilfs_iget_locked(sb, NULL, NILFS_SUFILE_INO);
1190         if (unlikely(!sufile))
1191                 return -ENOMEM;
1192         if (!(sufile->i_state & I_NEW))
1193                 goto out;
1194
1195         err = nilfs_mdt_init(sufile, NILFS_MDT_GFP, sizeof(*sui));
1196         if (err)
1197                 goto failed;
1198
1199         nilfs_mdt_set_entry_size(sufile, susize,
1200                                  sizeof(struct nilfs_sufile_header));
1201
1202         err = nilfs_read_inode_common(sufile, raw_inode);
1203         if (err)
1204                 goto failed;
1205
1206         err = nilfs_sufile_get_header_block(sufile, &header_bh);
1207         if (err)
1208                 goto failed;
1209
1210         sui = NILFS_SUI(sufile);
1211         kaddr = kmap_atomic(header_bh->b_page);
1212         header = kaddr + bh_offset(header_bh);
1213         sui->ncleansegs = le64_to_cpu(header->sh_ncleansegs);
1214         kunmap_atomic(kaddr);
1215         brelse(header_bh);
1216
1217         sui->allocmax = nilfs_sufile_get_nsegments(sufile) - 1;
1218         sui->allocmin = 0;
1219
1220         unlock_new_inode(sufile);
1221  out:
1222         *inodep = sufile;
1223         return 0;
1224  failed:
1225         iget_failed(sufile);
1226         return err;
1227 }