Linux 2.6.31-rc6
[linux-2.6] / fs / nilfs2 / ioctl.c
1 /*
2  * ioctl.c - NILFS ioctl operations.
3  *
4  * Copyright (C) 2007, 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 Koji Sato <koji@osrg.net>.
21  */
22
23 #include <linux/fs.h>
24 #include <linux/wait.h>
25 #include <linux/smp_lock.h>     /* lock_kernel(), unlock_kernel() */
26 #include <linux/capability.h>   /* capable() */
27 #include <linux/uaccess.h>      /* copy_from_user(), copy_to_user() */
28 #include <linux/vmalloc.h>
29 #include <linux/nilfs2_fs.h>
30 #include "nilfs.h"
31 #include "segment.h"
32 #include "bmap.h"
33 #include "cpfile.h"
34 #include "sufile.h"
35 #include "dat.h"
36
37
38 static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
39                                  struct nilfs_argv *argv, int dir,
40                                  ssize_t (*dofunc)(struct the_nilfs *,
41                                                    __u64 *, int,
42                                                    void *, size_t, size_t))
43 {
44         void *buf;
45         void __user *base = (void __user *)(unsigned long)argv->v_base;
46         size_t maxmembs, total, n;
47         ssize_t nr;
48         int ret, i;
49         __u64 pos, ppos;
50
51         if (argv->v_nmembs == 0)
52                 return 0;
53
54         if (argv->v_size > PAGE_SIZE)
55                 return -EINVAL;
56
57         buf = (void *)__get_free_pages(GFP_NOFS, 0);
58         if (unlikely(!buf))
59                 return -ENOMEM;
60         maxmembs = PAGE_SIZE / argv->v_size;
61
62         ret = 0;
63         total = 0;
64         pos = argv->v_index;
65         for (i = 0; i < argv->v_nmembs; i += n) {
66                 n = (argv->v_nmembs - i < maxmembs) ?
67                         argv->v_nmembs - i : maxmembs;
68                 if ((dir & _IOC_WRITE) &&
69                     copy_from_user(buf, base + argv->v_size * i,
70                                    argv->v_size * n)) {
71                         ret = -EFAULT;
72                         break;
73                 }
74                 ppos = pos;
75                 nr = dofunc(nilfs, &pos, argv->v_flags, buf, argv->v_size,
76                                n);
77                 if (nr < 0) {
78                         ret = nr;
79                         break;
80                 }
81                 if ((dir & _IOC_READ) &&
82                     copy_to_user(base + argv->v_size * i, buf,
83                                  argv->v_size * nr)) {
84                         ret = -EFAULT;
85                         break;
86                 }
87                 total += nr;
88                 if ((size_t)nr < n)
89                         break;
90                 if (pos == ppos)
91                         pos += n;
92         }
93         argv->v_nmembs = total;
94
95         free_pages((unsigned long)buf, 0);
96         return ret;
97 }
98
99 static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
100                                      unsigned int cmd, void __user *argp)
101 {
102         struct inode *cpfile = NILFS_SB(inode->i_sb)->s_nilfs->ns_cpfile;
103         struct nilfs_transaction_info ti;
104         struct nilfs_cpmode cpmode;
105         int ret;
106
107         if (!capable(CAP_SYS_ADMIN))
108                 return -EPERM;
109         if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
110                 return -EFAULT;
111
112         nilfs_transaction_begin(inode->i_sb, &ti, 0);
113         ret = nilfs_cpfile_change_cpmode(
114                 cpfile, cpmode.cm_cno, cpmode.cm_mode);
115         if (unlikely(ret < 0)) {
116                 nilfs_transaction_abort(inode->i_sb);
117                 return ret;
118         }
119         nilfs_transaction_commit(inode->i_sb); /* never fails */
120         return ret;
121 }
122
123 static int
124 nilfs_ioctl_delete_checkpoint(struct inode *inode, struct file *filp,
125                               unsigned int cmd, void __user *argp)
126 {
127         struct inode *cpfile = NILFS_SB(inode->i_sb)->s_nilfs->ns_cpfile;
128         struct nilfs_transaction_info ti;
129         __u64 cno;
130         int ret;
131
132         if (!capable(CAP_SYS_ADMIN))
133                 return -EPERM;
134         if (copy_from_user(&cno, argp, sizeof(cno)))
135                 return -EFAULT;
136
137         nilfs_transaction_begin(inode->i_sb, &ti, 0);
138         ret = nilfs_cpfile_delete_checkpoint(cpfile, cno);
139         if (unlikely(ret < 0)) {
140                 nilfs_transaction_abort(inode->i_sb);
141                 return ret;
142         }
143         nilfs_transaction_commit(inode->i_sb); /* never fails */
144         return ret;
145 }
146
147 static ssize_t
148 nilfs_ioctl_do_get_cpinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
149                           void *buf, size_t size, size_t nmembs)
150 {
151         int ret;
152
153         down_read(&nilfs->ns_segctor_sem);
154         ret = nilfs_cpfile_get_cpinfo(nilfs->ns_cpfile, posp, flags, buf,
155                                       size, nmembs);
156         up_read(&nilfs->ns_segctor_sem);
157         return ret;
158 }
159
160 static int nilfs_ioctl_get_cpstat(struct inode *inode, struct file *filp,
161                                   unsigned int cmd, void __user *argp)
162 {
163         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
164         struct nilfs_cpstat cpstat;
165         int ret;
166
167         down_read(&nilfs->ns_segctor_sem);
168         ret = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
169         up_read(&nilfs->ns_segctor_sem);
170         if (ret < 0)
171                 return ret;
172
173         if (copy_to_user(argp, &cpstat, sizeof(cpstat)))
174                 ret = -EFAULT;
175         return ret;
176 }
177
178 static ssize_t
179 nilfs_ioctl_do_get_suinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
180                           void *buf, size_t size, size_t nmembs)
181 {
182         int ret;
183
184         down_read(&nilfs->ns_segctor_sem);
185         ret = nilfs_sufile_get_suinfo(nilfs->ns_sufile, *posp, buf, size,
186                                       nmembs);
187         up_read(&nilfs->ns_segctor_sem);
188         return ret;
189 }
190
191 static int nilfs_ioctl_get_sustat(struct inode *inode, struct file *filp,
192                                   unsigned int cmd, void __user *argp)
193 {
194         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
195         struct nilfs_sustat sustat;
196         int ret;
197
198         down_read(&nilfs->ns_segctor_sem);
199         ret = nilfs_sufile_get_stat(nilfs->ns_sufile, &sustat);
200         up_read(&nilfs->ns_segctor_sem);
201         if (ret < 0)
202                 return ret;
203
204         if (copy_to_user(argp, &sustat, sizeof(sustat)))
205                 ret = -EFAULT;
206         return ret;
207 }
208
209 static ssize_t
210 nilfs_ioctl_do_get_vinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
211                          void *buf, size_t size, size_t nmembs)
212 {
213         int ret;
214
215         down_read(&nilfs->ns_segctor_sem);
216         ret = nilfs_dat_get_vinfo(nilfs_dat_inode(nilfs), buf, size, nmembs);
217         up_read(&nilfs->ns_segctor_sem);
218         return ret;
219 }
220
221 static ssize_t
222 nilfs_ioctl_do_get_bdescs(struct the_nilfs *nilfs, __u64 *posp, int flags,
223                           void *buf, size_t size, size_t nmembs)
224 {
225         struct inode *dat = nilfs_dat_inode(nilfs);
226         struct nilfs_bmap *bmap = NILFS_I(dat)->i_bmap;
227         struct nilfs_bdesc *bdescs = buf;
228         int ret, i;
229
230         down_read(&nilfs->ns_segctor_sem);
231         for (i = 0; i < nmembs; i++) {
232                 ret = nilfs_bmap_lookup_at_level(bmap,
233                                                  bdescs[i].bd_offset,
234                                                  bdescs[i].bd_level + 1,
235                                                  &bdescs[i].bd_blocknr);
236                 if (ret < 0) {
237                         if (ret != -ENOENT) {
238                                 up_read(&nilfs->ns_segctor_sem);
239                                 return ret;
240                         }
241                         bdescs[i].bd_blocknr = 0;
242                 }
243         }
244         up_read(&nilfs->ns_segctor_sem);
245         return nmembs;
246 }
247
248 static int nilfs_ioctl_get_bdescs(struct inode *inode, struct file *filp,
249                                   unsigned int cmd, void __user *argp)
250 {
251         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
252         struct nilfs_argv argv;
253         int ret;
254
255         if (copy_from_user(&argv, argp, sizeof(argv)))
256                 return -EFAULT;
257
258         if (argv.v_size != sizeof(struct nilfs_bdesc))
259                 return -EINVAL;
260
261         ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd),
262                                     nilfs_ioctl_do_get_bdescs);
263         if (ret < 0)
264                 return ret;
265
266         if (copy_to_user(argp, &argv, sizeof(argv)))
267                 ret = -EFAULT;
268         return ret;
269 }
270
271 static int nilfs_ioctl_move_inode_block(struct inode *inode,
272                                         struct nilfs_vdesc *vdesc,
273                                         struct list_head *buffers)
274 {
275         struct buffer_head *bh;
276         int ret;
277
278         if (vdesc->vd_flags == 0)
279                 ret = nilfs_gccache_submit_read_data(
280                         inode, vdesc->vd_offset, vdesc->vd_blocknr,
281                         vdesc->vd_vblocknr, &bh);
282         else
283                 ret = nilfs_gccache_submit_read_node(
284                         inode, vdesc->vd_blocknr, vdesc->vd_vblocknr, &bh);
285
286         if (unlikely(ret < 0)) {
287                 if (ret == -ENOENT)
288                         printk(KERN_CRIT
289                                "%s: invalid virtual block address (%s): "
290                                "ino=%llu, cno=%llu, offset=%llu, "
291                                "blocknr=%llu, vblocknr=%llu\n",
292                                __func__, vdesc->vd_flags ? "node" : "data",
293                                (unsigned long long)vdesc->vd_ino,
294                                (unsigned long long)vdesc->vd_cno,
295                                (unsigned long long)vdesc->vd_offset,
296                                (unsigned long long)vdesc->vd_blocknr,
297                                (unsigned long long)vdesc->vd_vblocknr);
298                 return ret;
299         }
300         bh->b_private = vdesc;
301         list_add_tail(&bh->b_assoc_buffers, buffers);
302         return 0;
303 }
304
305 static int nilfs_ioctl_move_blocks(struct the_nilfs *nilfs,
306                                    struct nilfs_argv *argv, void *buf)
307 {
308         size_t nmembs = argv->v_nmembs;
309         struct inode *inode;
310         struct nilfs_vdesc *vdesc;
311         struct buffer_head *bh, *n;
312         LIST_HEAD(buffers);
313         ino_t ino;
314         __u64 cno;
315         int i, ret;
316
317         for (i = 0, vdesc = buf; i < nmembs; ) {
318                 ino = vdesc->vd_ino;
319                 cno = vdesc->vd_cno;
320                 inode = nilfs_gc_iget(nilfs, ino, cno);
321                 if (unlikely(inode == NULL)) {
322                         ret = -ENOMEM;
323                         goto failed;
324                 }
325                 do {
326                         ret = nilfs_ioctl_move_inode_block(inode, vdesc,
327                                                            &buffers);
328                         if (unlikely(ret < 0))
329                                 goto failed;
330                         vdesc++;
331                 } while (++i < nmembs &&
332                          vdesc->vd_ino == ino && vdesc->vd_cno == cno);
333         }
334
335         list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
336                 ret = nilfs_gccache_wait_and_mark_dirty(bh);
337                 if (unlikely(ret < 0)) {
338                         if (ret == -EEXIST) {
339                                 vdesc = bh->b_private;
340                                 printk(KERN_CRIT
341                                        "%s: conflicting %s buffer: "
342                                        "ino=%llu, cno=%llu, offset=%llu, "
343                                        "blocknr=%llu, vblocknr=%llu\n",
344                                        __func__,
345                                        vdesc->vd_flags ? "node" : "data",
346                                        (unsigned long long)vdesc->vd_ino,
347                                        (unsigned long long)vdesc->vd_cno,
348                                        (unsigned long long)vdesc->vd_offset,
349                                        (unsigned long long)vdesc->vd_blocknr,
350                                        (unsigned long long)vdesc->vd_vblocknr);
351                         }
352                         goto failed;
353                 }
354                 list_del_init(&bh->b_assoc_buffers);
355                 bh->b_private = NULL;
356                 brelse(bh);
357         }
358         return nmembs;
359
360  failed:
361         list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
362                 list_del_init(&bh->b_assoc_buffers);
363                 bh->b_private = NULL;
364                 brelse(bh);
365         }
366         return ret;
367 }
368
369 static int nilfs_ioctl_delete_checkpoints(struct the_nilfs *nilfs,
370                                           struct nilfs_argv *argv, void *buf)
371 {
372         size_t nmembs = argv->v_nmembs;
373         struct inode *cpfile = nilfs->ns_cpfile;
374         struct nilfs_period *periods = buf;
375         int ret, i;
376
377         for (i = 0; i < nmembs; i++) {
378                 ret = nilfs_cpfile_delete_checkpoints(
379                         cpfile, periods[i].p_start, periods[i].p_end);
380                 if (ret < 0)
381                         return ret;
382         }
383         return nmembs;
384 }
385
386 static int nilfs_ioctl_free_vblocknrs(struct the_nilfs *nilfs,
387                                       struct nilfs_argv *argv, void *buf)
388 {
389         size_t nmembs = argv->v_nmembs;
390         int ret;
391
392         ret = nilfs_dat_freev(nilfs_dat_inode(nilfs), buf, nmembs);
393
394         return (ret < 0) ? ret : nmembs;
395 }
396
397 static int nilfs_ioctl_mark_blocks_dirty(struct the_nilfs *nilfs,
398                                          struct nilfs_argv *argv, void *buf)
399 {
400         size_t nmembs = argv->v_nmembs;
401         struct inode *dat = nilfs_dat_inode(nilfs);
402         struct nilfs_bmap *bmap = NILFS_I(dat)->i_bmap;
403         struct nilfs_bdesc *bdescs = buf;
404         int ret, i;
405
406         for (i = 0; i < nmembs; i++) {
407                 /* XXX: use macro or inline func to check liveness */
408                 ret = nilfs_bmap_lookup_at_level(bmap,
409                                                  bdescs[i].bd_offset,
410                                                  bdescs[i].bd_level + 1,
411                                                  &bdescs[i].bd_blocknr);
412                 if (ret < 0) {
413                         if (ret != -ENOENT)
414                                 return ret;
415                         bdescs[i].bd_blocknr = 0;
416                 }
417                 if (bdescs[i].bd_blocknr != bdescs[i].bd_oblocknr)
418                         /* skip dead block */
419                         continue;
420                 if (bdescs[i].bd_level == 0) {
421                         ret = nilfs_mdt_mark_block_dirty(dat,
422                                                          bdescs[i].bd_offset);
423                         if (ret < 0) {
424                                 WARN_ON(ret == -ENOENT);
425                                 return ret;
426                         }
427                 } else {
428                         ret = nilfs_bmap_mark(bmap, bdescs[i].bd_offset,
429                                               bdescs[i].bd_level);
430                         if (ret < 0) {
431                                 WARN_ON(ret == -ENOENT);
432                                 return ret;
433                         }
434                 }
435         }
436         return nmembs;
437 }
438
439 int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *nilfs,
440                                        struct nilfs_argv *argv, void **kbufs)
441 {
442         const char *msg;
443         int ret;
444
445         ret = nilfs_ioctl_move_blocks(nilfs, &argv[0], kbufs[0]);
446         if (ret < 0) {
447                 msg = "cannot read source blocks";
448                 goto failed;
449         }
450
451         ret = nilfs_ioctl_delete_checkpoints(nilfs, &argv[1], kbufs[1]);
452         if (ret < 0) {
453                 /*
454                  * can safely abort because checkpoints can be removed
455                  * independently.
456                  */
457                 msg = "cannot delete checkpoints";
458                 goto failed;
459         }
460         ret = nilfs_ioctl_free_vblocknrs(nilfs, &argv[2], kbufs[2]);
461         if (ret < 0) {
462                 /*
463                  * can safely abort because DAT file is updated atomically
464                  * using a copy-on-write technique.
465                  */
466                 msg = "cannot delete virtual blocks from DAT file";
467                 goto failed;
468         }
469         ret = nilfs_ioctl_mark_blocks_dirty(nilfs, &argv[3], kbufs[3]);
470         if (ret < 0) {
471                 /*
472                  * can safely abort because the operation is nondestructive.
473                  */
474                 msg = "cannot mark copying blocks dirty";
475                 goto failed;
476         }
477         return 0;
478
479  failed:
480         nilfs_remove_all_gcinode(nilfs);
481         printk(KERN_ERR "NILFS: GC failed during preparation: %s: err=%d\n",
482                msg, ret);
483         return ret;
484 }
485
486 static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
487                                       unsigned int cmd, void __user *argp)
488 {
489         struct nilfs_argv argv[5];
490         const static size_t argsz[5] = {
491                 sizeof(struct nilfs_vdesc),
492                 sizeof(struct nilfs_period),
493                 sizeof(__u64),
494                 sizeof(struct nilfs_bdesc),
495                 sizeof(__u64),
496         };
497         void __user *base;
498         void *kbufs[5];
499         struct the_nilfs *nilfs;
500         size_t len, nsegs;
501         int n, ret;
502
503         if (!capable(CAP_SYS_ADMIN))
504                 return -EPERM;
505
506         if (copy_from_user(argv, argp, sizeof(argv)))
507                 return -EFAULT;
508
509         nsegs = argv[4].v_nmembs;
510         if (argv[4].v_size != argsz[4])
511                 return -EINVAL;
512         /*
513          * argv[4] points to segment numbers this ioctl cleans.  We
514          * use kmalloc() for its buffer because memory used for the
515          * segment numbers is enough small.
516          */
517         kbufs[4] = memdup_user((void __user *)(unsigned long)argv[4].v_base,
518                                nsegs * sizeof(__u64));
519         if (IS_ERR(kbufs[4]))
520                 return PTR_ERR(kbufs[4]);
521
522         nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
523
524         for (n = 0; n < 4; n++) {
525                 ret = -EINVAL;
526                 if (argv[n].v_size != argsz[n])
527                         goto out_free;
528
529                 if (argv[n].v_nmembs > nsegs * nilfs->ns_blocks_per_segment)
530                         goto out_free;
531
532                 len = argv[n].v_size * argv[n].v_nmembs;
533                 base = (void __user *)(unsigned long)argv[n].v_base;
534                 if (len == 0) {
535                         kbufs[n] = NULL;
536                         continue;
537                 }
538
539                 kbufs[n] = vmalloc(len);
540                 if (!kbufs[n]) {
541                         ret = -ENOMEM;
542                         goto out_free;
543                 }
544                 if (copy_from_user(kbufs[n], base, len)) {
545                         ret = -EFAULT;
546                         vfree(kbufs[n]);
547                         goto out_free;
548                 }
549         }
550
551         ret = nilfs_clean_segments(inode->i_sb, argv, kbufs);
552
553  out_free:
554         while (--n >= 0)
555                 vfree(kbufs[n]);
556         kfree(kbufs[4]);
557         return ret;
558 }
559
560 static int nilfs_ioctl_sync(struct inode *inode, struct file *filp,
561                             unsigned int cmd, void __user *argp)
562 {
563         __u64 cno;
564         int ret;
565
566         ret = nilfs_construct_segment(inode->i_sb);
567         if (ret < 0)
568                 return ret;
569
570         if (argp != NULL) {
571                 cno = NILFS_SB(inode->i_sb)->s_nilfs->ns_cno - 1;
572                 if (copy_to_user(argp, &cno, sizeof(cno)))
573                         return -EFAULT;
574         }
575         return 0;
576 }
577
578 static int nilfs_ioctl_get_info(struct inode *inode, struct file *filp,
579                                 unsigned int cmd, void __user *argp,
580                                 size_t membsz,
581                                 ssize_t (*dofunc)(struct the_nilfs *,
582                                                   __u64 *, int,
583                                                   void *, size_t, size_t))
584
585 {
586         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
587         struct nilfs_argv argv;
588         int ret;
589
590         if (copy_from_user(&argv, argp, sizeof(argv)))
591                 return -EFAULT;
592
593         if (argv.v_size < membsz)
594                 return -EINVAL;
595
596         ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd), dofunc);
597         if (ret < 0)
598                 return ret;
599
600         if (copy_to_user(argp, &argv, sizeof(argv)))
601                 ret = -EFAULT;
602         return ret;
603 }
604
605 long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
606 {
607         struct inode *inode = filp->f_dentry->d_inode;
608         void __user *argp = (void * __user *)arg;
609
610         switch (cmd) {
611         case NILFS_IOCTL_CHANGE_CPMODE:
612                 return nilfs_ioctl_change_cpmode(inode, filp, cmd, argp);
613         case NILFS_IOCTL_DELETE_CHECKPOINT:
614                 return nilfs_ioctl_delete_checkpoint(inode, filp, cmd, argp);
615         case NILFS_IOCTL_GET_CPINFO:
616                 return nilfs_ioctl_get_info(inode, filp, cmd, argp,
617                                             sizeof(struct nilfs_cpinfo),
618                                             nilfs_ioctl_do_get_cpinfo);
619         case NILFS_IOCTL_GET_CPSTAT:
620                 return nilfs_ioctl_get_cpstat(inode, filp, cmd, argp);
621         case NILFS_IOCTL_GET_SUINFO:
622                 return nilfs_ioctl_get_info(inode, filp, cmd, argp,
623                                             sizeof(struct nilfs_suinfo),
624                                             nilfs_ioctl_do_get_suinfo);
625         case NILFS_IOCTL_GET_SUSTAT:
626                 return nilfs_ioctl_get_sustat(inode, filp, cmd, argp);
627         case NILFS_IOCTL_GET_VINFO:
628                 return nilfs_ioctl_get_info(inode, filp, cmd, argp,
629                                             sizeof(struct nilfs_vinfo),
630                                             nilfs_ioctl_do_get_vinfo);
631         case NILFS_IOCTL_GET_BDESCS:
632                 return nilfs_ioctl_get_bdescs(inode, filp, cmd, argp);
633         case NILFS_IOCTL_CLEAN_SEGMENTS:
634                 return nilfs_ioctl_clean_segments(inode, filp, cmd, argp);
635         case NILFS_IOCTL_SYNC:
636                 return nilfs_ioctl_sync(inode, filp, cmd, argp);
637         default:
638                 return -ENOTTY;
639         }
640 }