9p: implement optional loose read cache
[linux-2.6.git] / fs / 9p / vfs_inode.c
1 /*
2  *  linux/fs/9p/vfs_inode.c
3  *
4  * This file contains vfs inode ops for the 9P2000 protocol.
5  *
6  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
7  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License version 2
11  *  as published by the Free Software Foundation.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to:
20  *  Free Software Foundation
21  *  51 Franklin Street, Fifth Floor
22  *  Boston, MA  02111-1301  USA
23  *
24  */
25
26 #include <linux/module.h>
27 #include <linux/errno.h>
28 #include <linux/fs.h>
29 #include <linux/file.h>
30 #include <linux/pagemap.h>
31 #include <linux/stat.h>
32 #include <linux/string.h>
33 #include <linux/smp_lock.h>
34 #include <linux/inet.h>
35 #include <linux/namei.h>
36 #include <linux/idr.h>
37
38 #include "debug.h"
39 #include "v9fs.h"
40 #include "9p.h"
41 #include "v9fs_vfs.h"
42 #include "fid.h"
43
44 static const struct inode_operations v9fs_dir_inode_operations;
45 static const struct inode_operations v9fs_dir_inode_operations_ext;
46 static const struct inode_operations v9fs_file_inode_operations;
47 static const struct inode_operations v9fs_symlink_inode_operations;
48
49 /**
50  * unixmode2p9mode - convert unix mode bits to plan 9
51  * @v9ses: v9fs session information
52  * @mode: mode to convert
53  *
54  */
55
56 static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
57 {
58         int res;
59         res = mode & 0777;
60         if (S_ISDIR(mode))
61                 res |= V9FS_DMDIR;
62         if (v9ses->extended) {
63                 if (S_ISLNK(mode))
64                         res |= V9FS_DMSYMLINK;
65                 if (v9ses->nodev == 0) {
66                         if (S_ISSOCK(mode))
67                                 res |= V9FS_DMSOCKET;
68                         if (S_ISFIFO(mode))
69                                 res |= V9FS_DMNAMEDPIPE;
70                         if (S_ISBLK(mode))
71                                 res |= V9FS_DMDEVICE;
72                         if (S_ISCHR(mode))
73                                 res |= V9FS_DMDEVICE;
74                 }
75
76                 if ((mode & S_ISUID) == S_ISUID)
77                         res |= V9FS_DMSETUID;
78                 if ((mode & S_ISGID) == S_ISGID)
79                         res |= V9FS_DMSETGID;
80                 if ((mode & V9FS_DMLINK))
81                         res |= V9FS_DMLINK;
82         }
83
84         return res;
85 }
86
87 /**
88  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
89  * @v9ses: v9fs session information
90  * @mode: mode to convert
91  *
92  */
93
94 static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
95 {
96         int res;
97
98         res = mode & 0777;
99
100         if ((mode & V9FS_DMDIR) == V9FS_DMDIR)
101                 res |= S_IFDIR;
102         else if ((mode & V9FS_DMSYMLINK) && (v9ses->extended))
103                 res |= S_IFLNK;
104         else if ((mode & V9FS_DMSOCKET) && (v9ses->extended)
105                  && (v9ses->nodev == 0))
106                 res |= S_IFSOCK;
107         else if ((mode & V9FS_DMNAMEDPIPE) && (v9ses->extended)
108                  && (v9ses->nodev == 0))
109                 res |= S_IFIFO;
110         else if ((mode & V9FS_DMDEVICE) && (v9ses->extended)
111                  && (v9ses->nodev == 0))
112                 res |= S_IFBLK;
113         else
114                 res |= S_IFREG;
115
116         if (v9ses->extended) {
117                 if ((mode & V9FS_DMSETUID) == V9FS_DMSETUID)
118                         res |= S_ISUID;
119
120                 if ((mode & V9FS_DMSETGID) == V9FS_DMSETGID)
121                         res |= S_ISGID;
122         }
123
124         return res;
125 }
126
127 int v9fs_uflags2omode(int uflags)
128 {
129         int ret;
130
131         ret = 0;
132         switch (uflags&3) {
133         default:
134         case O_RDONLY:
135                 ret = V9FS_OREAD;
136                 break;
137
138         case O_WRONLY:
139                 ret = V9FS_OWRITE;
140                 break;
141
142         case O_RDWR:
143                 ret = V9FS_ORDWR;
144                 break;
145         }
146
147         if (uflags & O_EXCL)
148                 ret |= V9FS_OEXCL;
149
150         if (uflags & O_TRUNC)
151                 ret |= V9FS_OTRUNC;
152
153         if (uflags & O_APPEND)
154                 ret |= V9FS_OAPPEND;
155
156         return ret;
157 }
158
159 /**
160  * v9fs_blank_wstat - helper function to setup a 9P stat structure
161  * @v9ses: 9P session info (for determining extended mode)
162  * @wstat: structure to initialize
163  *
164  */
165
166 static void
167 v9fs_blank_wstat(struct v9fs_wstat *wstat)
168 {
169         wstat->type = ~0;
170         wstat->dev = ~0;
171         wstat->qid.type = ~0;
172         wstat->qid.version = ~0;
173         *((long long *)&wstat->qid.path) = ~0;
174         wstat->mode = ~0;
175         wstat->atime = ~0;
176         wstat->mtime = ~0;
177         wstat->length = ~0;
178         wstat->name = NULL;
179         wstat->uid = NULL;
180         wstat->gid = NULL;
181         wstat->muid = NULL;
182         wstat->n_uid = ~0;
183         wstat->n_gid = ~0;
184         wstat->n_muid = ~0;
185         wstat->extension = NULL;
186 }
187
188 /**
189  * v9fs_get_inode - helper function to setup an inode
190  * @sb: superblock
191  * @mode: mode to setup inode with
192  *
193  */
194
195 struct inode *v9fs_get_inode(struct super_block *sb, int mode)
196 {
197         struct inode *inode;
198         struct v9fs_session_info *v9ses = sb->s_fs_info;
199
200         dprintk(DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
201
202         inode = new_inode(sb);
203         if (inode) {
204                 inode->i_mode = mode;
205                 inode->i_uid = current->fsuid;
206                 inode->i_gid = current->fsgid;
207                 inode->i_blocks = 0;
208                 inode->i_rdev = 0;
209                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
210                 inode->i_mapping->a_ops = &v9fs_addr_operations;
211
212                 switch (mode & S_IFMT) {
213                 case S_IFIFO:
214                 case S_IFBLK:
215                 case S_IFCHR:
216                 case S_IFSOCK:
217                         if(!v9ses->extended) {
218                                 dprintk(DEBUG_ERROR, "special files without extended mode\n");
219                                 return ERR_PTR(-EINVAL);
220                         }
221                         init_special_inode(inode, inode->i_mode,
222                                            inode->i_rdev);
223                         break;
224                 case S_IFREG:
225                         inode->i_op = &v9fs_file_inode_operations;
226                         inode->i_fop = &v9fs_file_operations;
227                         break;
228                 case S_IFLNK:
229                         if(!v9ses->extended) {
230                                 dprintk(DEBUG_ERROR, "extended modes used w/o 9P2000.u\n");
231                                 return ERR_PTR(-EINVAL);
232                         }
233                         inode->i_op = &v9fs_symlink_inode_operations;
234                         break;
235                 case S_IFDIR:
236                         inc_nlink(inode);
237                         if(v9ses->extended)
238                                 inode->i_op = &v9fs_dir_inode_operations_ext;
239                         else
240                                 inode->i_op = &v9fs_dir_inode_operations;
241                         inode->i_fop = &v9fs_dir_operations;
242                         break;
243                 default:
244                         dprintk(DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
245                                 mode, mode & S_IFMT);
246                         return ERR_PTR(-EINVAL);
247                 }
248         } else {
249                 eprintk(KERN_WARNING, "Problem allocating inode\n");
250                 return ERR_PTR(-ENOMEM);
251         }
252         return inode;
253 }
254
255 static int
256 v9fs_create(struct v9fs_session_info *v9ses, u32 pfid, char *name, u32 perm,
257         u8 mode, char *extension, u32 *fidp, struct v9fs_qid *qid, u32 *iounit)
258 {
259         int fid;
260         int err;
261         struct v9fs_fcall *fcall;
262
263         fid = v9fs_get_idpool(&v9ses->fidpool);
264         if (fid < 0) {
265                 eprintk(KERN_WARNING, "no free fids available\n");
266                 return -ENOSPC;
267         }
268
269         err = v9fs_t_walk(v9ses, pfid, fid, NULL, &fcall);
270         if (err < 0) {
271                 PRINT_FCALL_ERROR("clone error", fcall);
272                 if (fcall && fcall->id == RWALK)
273                         goto clunk_fid;
274                 else
275                         goto put_fid;
276         }
277         kfree(fcall);
278
279         err = v9fs_t_create(v9ses, fid, name, perm, mode, extension, &fcall);
280         if (err < 0) {
281                 PRINT_FCALL_ERROR("create fails", fcall);
282                 goto clunk_fid;
283         }
284
285         if (iounit)
286                 *iounit = fcall->params.rcreate.iounit;
287
288         if (qid)
289                 *qid = fcall->params.rcreate.qid;
290
291         if (fidp)
292                 *fidp = fid;
293
294         kfree(fcall);
295         return 0;
296
297 clunk_fid:
298         v9fs_t_clunk(v9ses, fid);
299         fid = V9FS_NOFID;
300
301 put_fid:
302         if (fid != V9FS_NOFID)
303                 v9fs_put_idpool(fid, &v9ses->fidpool);
304
305         kfree(fcall);
306         return err;
307 }
308
309 static struct v9fs_fid*
310 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
311 {
312         int err;
313         int nfid;
314         struct v9fs_fid *ret;
315         struct v9fs_fcall *fcall;
316
317         nfid = v9fs_get_idpool(&v9ses->fidpool);
318         if (nfid < 0) {
319                 eprintk(KERN_WARNING, "no free fids available\n");
320                 return ERR_PTR(-ENOSPC);
321         }
322
323         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
324                 &fcall);
325
326         if (err < 0) {
327                 if (fcall && fcall->id == RWALK)
328                         goto clunk_fid;
329
330                 PRINT_FCALL_ERROR("walk error", fcall);
331                 v9fs_put_idpool(nfid, &v9ses->fidpool);
332                 goto error;
333         }
334
335         kfree(fcall);
336         fcall = NULL;
337         ret = v9fs_fid_create(v9ses, nfid);
338         if (!ret) {
339                 err = -ENOMEM;
340                 goto clunk_fid;
341         }
342
343         err = v9fs_fid_insert(ret, dentry);
344         if (err < 0) {
345                 v9fs_fid_destroy(ret);
346                 goto clunk_fid;
347         }
348
349         return ret;
350
351 clunk_fid:
352         v9fs_t_clunk(v9ses, nfid);
353
354 error:
355         kfree(fcall);
356         return ERR_PTR(err);
357 }
358
359 static struct inode *
360 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, u32 fid,
361         struct super_block *sb)
362 {
363         int err, umode;
364         struct inode *ret;
365         struct v9fs_fcall *fcall;
366
367         ret = NULL;
368         err = v9fs_t_stat(v9ses, fid, &fcall);
369         if (err) {
370                 PRINT_FCALL_ERROR("stat error", fcall);
371                 goto error;
372         }
373
374         umode = p9mode2unixmode(v9ses, fcall->params.rstat.stat.mode);
375         ret = v9fs_get_inode(sb, umode);
376         if (IS_ERR(ret)) {
377                 err = PTR_ERR(ret);
378                 ret = NULL;
379                 goto error;
380         }
381
382         v9fs_stat2inode(&fcall->params.rstat.stat, ret, sb);
383         kfree(fcall);
384         return ret;
385
386 error:
387         kfree(fcall);
388         if (ret)
389                 iput(ret);
390
391         return ERR_PTR(err);
392 }
393
394 /**
395  * v9fs_remove - helper function to remove files and directories
396  * @dir: directory inode that is being deleted
397  * @file:  dentry that is being deleted
398  * @rmdir: removing a directory
399  *
400  */
401
402 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
403 {
404         struct v9fs_fcall *fcall = NULL;
405         struct super_block *sb = NULL;
406         struct v9fs_session_info *v9ses = NULL;
407         struct v9fs_fid *v9fid = NULL;
408         struct inode *file_inode = NULL;
409         int fid = -1;
410         int result = 0;
411
412         dprintk(DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
413                 rmdir);
414
415         file_inode = file->d_inode;
416         sb = file_inode->i_sb;
417         v9ses = v9fs_inode2v9ses(file_inode);
418         v9fid = v9fs_fid_lookup(file);
419         if(IS_ERR(v9fid))
420                 return PTR_ERR(v9fid);
421
422         fid = v9fid->fid;
423         if (fid < 0) {
424                 dprintk(DEBUG_ERROR, "inode #%lu, no fid!\n",
425                         file_inode->i_ino);
426                 return -EBADF;
427         }
428
429         result = v9fs_t_remove(v9ses, fid, &fcall);
430         if (result < 0) {
431                 PRINT_FCALL_ERROR("remove fails", fcall);
432                 goto Error;
433         }
434
435         v9fs_put_idpool(fid, &v9ses->fidpool);
436         v9fs_fid_destroy(v9fid);
437
438 Error:
439         kfree(fcall);
440         return result;
441 }
442
443 static int
444 v9fs_open_created(struct inode *inode, struct file *file)
445 {
446         return 0;
447 }
448
449 /**
450  * v9fs_vfs_create - VFS hook to create files
451  * @inode: directory inode that is being deleted
452  * @dentry:  dentry that is being deleted
453  * @mode: create permissions
454  * @nd: path information
455  *
456  */
457
458 static int
459 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
460                 struct nameidata *nd)
461 {
462         int err;
463         u32 fid, perm, iounit;
464         int flags;
465         struct v9fs_session_info *v9ses;
466         struct v9fs_fid *dfid, *vfid, *ffid;
467         struct inode *inode;
468         struct v9fs_qid qid;
469         struct file *filp;
470
471         inode = NULL;
472         vfid = NULL;
473         v9ses = v9fs_inode2v9ses(dir);
474         dfid = v9fs_fid_clone(dentry->d_parent);
475         if(IS_ERR(dfid)) {
476                 err = PTR_ERR(dfid);
477                 goto error;
478         }
479
480         perm = unixmode2p9mode(v9ses, mode);
481         if (nd && nd->flags & LOOKUP_OPEN)
482                 flags = nd->intent.open.flags - 1;
483         else
484                 flags = O_RDWR;
485
486         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
487                 perm, v9fs_uflags2omode(flags), NULL, &fid, &qid, &iounit);
488
489         if (err)
490                 goto clunk_dfid;
491
492         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
493         v9fs_fid_clunk(v9ses, dfid);
494         if (IS_ERR(vfid)) {
495                 err = PTR_ERR(vfid);
496                 vfid = NULL;
497                 goto error;
498         }
499
500         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
501         if (IS_ERR(inode)) {
502                 err = PTR_ERR(inode);
503                 inode = NULL;
504                 goto error;
505         }
506
507         if(v9ses->cache)
508                 dentry->d_op = &v9fs_cached_dentry_operations;
509         else
510                 dentry->d_op = &v9fs_dentry_operations;
511         d_instantiate(dentry, inode);
512
513         if (nd && nd->flags & LOOKUP_OPEN) {
514                 ffid = v9fs_fid_create(v9ses, fid);
515                 if (!ffid)
516                         return -ENOMEM;
517
518                 filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
519                 if (IS_ERR(filp)) {
520                         v9fs_fid_destroy(ffid);
521                         return PTR_ERR(filp);
522                 }
523
524                 ffid->rdir_pos = 0;
525                 ffid->rdir_fcall = NULL;
526                 ffid->fidopen = 1;
527                 ffid->iounit = iounit;
528                 ffid->filp = filp;
529                 filp->private_data = ffid;
530         }
531
532         return 0;
533
534 clunk_dfid:
535         v9fs_fid_clunk(v9ses, dfid);
536
537 error:
538         if (vfid)
539                 v9fs_fid_destroy(vfid);
540
541         return err;
542 }
543
544 /**
545  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
546  * @inode:  inode that is being unlinked
547  * @dentry: dentry that is being unlinked
548  * @mode: mode for new directory
549  *
550  */
551
552 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
553 {
554         int err;
555         u32 fid, perm;
556         struct v9fs_session_info *v9ses;
557         struct v9fs_fid *dfid, *vfid;
558         struct inode *inode;
559
560         inode = NULL;
561         vfid = NULL;
562         v9ses = v9fs_inode2v9ses(dir);
563         dfid = v9fs_fid_clone(dentry->d_parent);
564         if(IS_ERR(dfid)) {
565                 err = PTR_ERR(dfid);
566                 goto error;
567         }
568
569         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
570
571         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
572                 perm, V9FS_OREAD, NULL, &fid, NULL, NULL);
573
574         if (err) {
575                 dprintk(DEBUG_ERROR, "create error %d\n", err);
576                 goto clean_up_dfid;
577         }
578
579         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
580         if (IS_ERR(vfid)) {
581                 err = PTR_ERR(vfid);
582                 vfid = NULL;
583                 goto clean_up_dfid;
584         }
585
586         v9fs_fid_clunk(v9ses, dfid);
587         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
588         if (IS_ERR(inode)) {
589                 err = PTR_ERR(inode);
590                 inode = NULL;
591                 v9fs_fid_destroy(vfid);
592                 goto error;
593         }
594
595         if(v9ses->cache)
596                 dentry->d_op = &v9fs_cached_dentry_operations;
597         else
598                 dentry->d_op = &v9fs_dentry_operations;
599         d_instantiate(dentry, inode);
600         return 0;
601
602 clean_up_dfid:
603         v9fs_fid_clunk(v9ses, dfid);
604
605 error:
606         return err;
607 }
608
609 /**
610  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
611  * @dir:  inode that is being walked from
612  * @dentry: dentry that is being walked to?
613  * @nameidata: path data
614  *
615  */
616
617 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
618                                       struct nameidata *nameidata)
619 {
620         struct super_block *sb;
621         struct v9fs_session_info *v9ses;
622         struct v9fs_fid *dirfid;
623         struct v9fs_fid *fid;
624         struct inode *inode;
625         struct v9fs_fcall *fcall = NULL;
626         int dirfidnum = -1;
627         int newfid = -1;
628         int result = 0;
629
630         dprintk(DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
631                 dir, dentry->d_name.name, dentry, nameidata);
632
633         sb = dir->i_sb;
634         v9ses = v9fs_inode2v9ses(dir);
635         dirfid = v9fs_fid_lookup(dentry->d_parent);
636
637         if(IS_ERR(dirfid))
638                 return ERR_PTR(PTR_ERR(dirfid));
639
640         dirfidnum = dirfid->fid;
641
642         newfid = v9fs_get_idpool(&v9ses->fidpool);
643         if (newfid < 0) {
644                 eprintk(KERN_WARNING, "newfid fails!\n");
645                 result = -ENOSPC;
646                 goto Release_Dirfid;
647         }
648
649         result = v9fs_t_walk(v9ses, dirfidnum, newfid,
650                 (char *)dentry->d_name.name, &fcall);
651
652         up(&dirfid->lock);
653
654         if (result < 0) {
655                 if (fcall && fcall->id == RWALK)
656                         v9fs_t_clunk(v9ses, newfid);
657                 else
658                         v9fs_put_idpool(newfid, &v9ses->fidpool);
659
660                 if (result == -ENOENT) {
661                         d_add(dentry, NULL);
662                         dprintk(DEBUG_VFS,
663                                 "Return negative dentry %p count %d\n",
664                                 dentry, atomic_read(&dentry->d_count));
665                         kfree(fcall);
666                         return NULL;
667                 }
668                 dprintk(DEBUG_ERROR, "walk error:%d\n", result);
669                 goto FreeFcall;
670         }
671         kfree(fcall);
672
673         result = v9fs_t_stat(v9ses, newfid, &fcall);
674         if (result < 0) {
675                 dprintk(DEBUG_ERROR, "stat error\n");
676                 goto FreeFcall;
677         }
678
679         inode = v9fs_get_inode(sb, p9mode2unixmode(v9ses,
680                 fcall->params.rstat.stat.mode));
681
682         if (IS_ERR(inode) && (PTR_ERR(inode) == -ENOSPC)) {
683                 eprintk(KERN_WARNING, "inode alloc failes, returns %ld\n",
684                         PTR_ERR(inode));
685
686                 result = -ENOSPC;
687                 goto FreeFcall;
688         }
689
690         inode->i_ino = v9fs_qid2ino(&fcall->params.rstat.stat.qid);
691
692         fid = v9fs_fid_create(v9ses, newfid);
693         if (fid == NULL) {
694                 dprintk(DEBUG_ERROR, "couldn't insert\n");
695                 result = -ENOMEM;
696                 goto FreeFcall;
697         }
698
699         result = v9fs_fid_insert(fid, dentry);
700         if (result < 0)
701                 goto FreeFcall;
702
703         fid->qid = fcall->params.rstat.stat.qid;
704         v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb);
705         if((fid->qid.version)&&(v9ses->cache))
706                 dentry->d_op = &v9fs_cached_dentry_operations;
707         else
708                 dentry->d_op = &v9fs_dentry_operations;
709
710         d_add(dentry, inode);
711         kfree(fcall);
712
713         return NULL;
714
715 Release_Dirfid:
716         up(&dirfid->lock);
717
718 FreeFcall:
719         kfree(fcall);
720
721         return ERR_PTR(result);
722 }
723
724 /**
725  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
726  * @i:  inode that is being unlinked
727  * @d: dentry that is being unlinked
728  *
729  */
730
731 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
732 {
733         return v9fs_remove(i, d, 0);
734 }
735
736 /**
737  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
738  * @i:  inode that is being unlinked
739  * @d: dentry that is being unlinked
740  *
741  */
742
743 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
744 {
745         return v9fs_remove(i, d, 1);
746 }
747
748 /**
749  * v9fs_vfs_rename - VFS hook to rename an inode
750  * @old_dir:  old dir inode
751  * @old_dentry: old dentry
752  * @new_dir: new dir inode
753  * @new_dentry: new dentry
754  *
755  */
756
757 static int
758 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
759                 struct inode *new_dir, struct dentry *new_dentry)
760 {
761         struct inode *old_inode = old_dentry->d_inode;
762         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(old_inode);
763         struct v9fs_fid *oldfid = v9fs_fid_lookup(old_dentry);
764         struct v9fs_fid *olddirfid;
765         struct v9fs_fid *newdirfid;
766         struct v9fs_wstat wstat;
767         struct v9fs_fcall *fcall = NULL;
768         int fid = -1;
769         int olddirfidnum = -1;
770         int newdirfidnum = -1;
771         int retval = 0;
772
773         dprintk(DEBUG_VFS, "\n");
774
775         if(IS_ERR(oldfid))
776                 return PTR_ERR(oldfid);
777
778         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
779         if(IS_ERR(olddirfid)) {
780                 retval = PTR_ERR(olddirfid);
781                 goto Release_lock;
782         }
783
784         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
785         if(IS_ERR(newdirfid)) {
786                 retval = PTR_ERR(newdirfid);
787                 goto Clunk_olddir;
788         }
789
790         /* 9P can only handle file rename in the same directory */
791         if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
792                 dprintk(DEBUG_ERROR, "old dir and new dir are different\n");
793                 retval = -EXDEV;
794                 goto Clunk_newdir;
795         }
796
797         fid = oldfid->fid;
798         olddirfidnum = olddirfid->fid;
799         newdirfidnum = newdirfid->fid;
800
801         if (fid < 0) {
802                 dprintk(DEBUG_ERROR, "no fid for old file #%lu\n",
803                         old_inode->i_ino);
804                 retval = -EBADF;
805                 goto Clunk_newdir;
806         }
807
808         v9fs_blank_wstat(&wstat);
809         wstat.muid = v9ses->name;
810         wstat.name = (char *) new_dentry->d_name.name;
811
812         retval = v9fs_t_wstat(v9ses, fid, &wstat, &fcall);
813
814         if (retval < 0)
815                 PRINT_FCALL_ERROR("wstat error", fcall);
816
817         kfree(fcall);
818
819 Clunk_newdir:
820         v9fs_fid_clunk(v9ses, newdirfid);
821
822 Clunk_olddir:
823         v9fs_fid_clunk(v9ses, olddirfid);
824
825 Release_lock:
826         up(&oldfid->lock);
827
828         return retval;
829 }
830
831 /**
832  * v9fs_vfs_getattr - retrieve file metadata
833  * @mnt - mount information
834  * @dentry - file to get attributes on
835  * @stat - metadata structure to populate
836  *
837  */
838
839 static int
840 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
841                  struct kstat *stat)
842 {
843         struct v9fs_fcall *fcall = NULL;
844         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
845         struct v9fs_fid *fid = v9fs_fid_clone(dentry);
846         int err = -EPERM;
847
848         dprintk(DEBUG_VFS, "dentry: %p\n", dentry);
849         if(IS_ERR(fid))
850                 return PTR_ERR(fid);
851
852         err = v9fs_t_stat(v9ses, fid->fid, &fcall);
853
854         if (err < 0)
855                 dprintk(DEBUG_ERROR, "stat error\n");
856         else {
857                 v9fs_stat2inode(&fcall->params.rstat.stat, dentry->d_inode,
858                                   dentry->d_inode->i_sb);
859                 generic_fillattr(dentry->d_inode, stat);
860         }
861
862         kfree(fcall);
863         v9fs_fid_clunk(v9ses, fid);
864         return err;
865 }
866
867 /**
868  * v9fs_vfs_setattr - set file metadata
869  * @dentry: file whose metadata to set
870  * @iattr: metadata assignment structure
871  *
872  */
873
874 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
875 {
876         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
877         struct v9fs_fid *fid = v9fs_fid_clone(dentry);
878         struct v9fs_fcall *fcall = NULL;
879         struct v9fs_wstat wstat;
880         int res = -EPERM;
881
882         dprintk(DEBUG_VFS, "\n");
883         if(IS_ERR(fid))
884                 return PTR_ERR(fid);
885
886         v9fs_blank_wstat(&wstat);
887         if (iattr->ia_valid & ATTR_MODE)
888                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
889
890         if (iattr->ia_valid & ATTR_MTIME)
891                 wstat.mtime = iattr->ia_mtime.tv_sec;
892
893         if (iattr->ia_valid & ATTR_ATIME)
894                 wstat.atime = iattr->ia_atime.tv_sec;
895
896         if (iattr->ia_valid & ATTR_SIZE)
897                 wstat.length = iattr->ia_size;
898
899         if (v9ses->extended) {
900                 if (iattr->ia_valid & ATTR_UID)
901                         wstat.n_uid = iattr->ia_uid;
902
903                 if (iattr->ia_valid & ATTR_GID)
904                         wstat.n_gid = iattr->ia_gid;
905         }
906
907         res = v9fs_t_wstat(v9ses, fid->fid, &wstat, &fcall);
908
909         if (res < 0)
910                 PRINT_FCALL_ERROR("wstat error", fcall);
911
912         kfree(fcall);
913         if (res >= 0)
914                 res = inode_setattr(dentry->d_inode, iattr);
915
916         v9fs_fid_clunk(v9ses, fid);
917         return res;
918 }
919
920 /**
921  * v9fs_stat2inode - populate an inode structure with mistat info
922  * @stat: Plan 9 metadata (mistat) structure
923  * @inode: inode to populate
924  * @sb: superblock of filesystem
925  *
926  */
927
928 void
929 v9fs_stat2inode(struct v9fs_stat *stat, struct inode *inode,
930         struct super_block *sb)
931 {
932         int n;
933         char ext[32];
934         struct v9fs_session_info *v9ses = sb->s_fs_info;
935
936         inode->i_nlink = 1;
937
938         inode->i_atime.tv_sec = stat->atime;
939         inode->i_mtime.tv_sec = stat->mtime;
940         inode->i_ctime.tv_sec = stat->mtime;
941
942         inode->i_uid = v9ses->uid;
943         inode->i_gid = v9ses->gid;
944
945         if (v9ses->extended) {
946                 inode->i_uid = stat->n_uid;
947                 inode->i_gid = stat->n_gid;
948         }
949
950         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
951         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
952                 char type = 0;
953                 int major = -1;
954                 int minor = -1;
955
956                 n = stat->extension.len;
957                 if (n > sizeof(ext)-1)
958                         n = sizeof(ext)-1;
959                 memmove(ext, stat->extension.str, n);
960                 ext[n] = 0;
961                 sscanf(ext, "%c %u %u", &type, &major, &minor);
962                 switch (type) {
963                 case 'c':
964                         inode->i_mode &= ~S_IFBLK;
965                         inode->i_mode |= S_IFCHR;
966                         break;
967                 case 'b':
968                         break;
969                 default:
970                         dprintk(DEBUG_ERROR, "Unknown special type %c (%.*s)\n",
971                                 type, stat->extension.len, stat->extension.str);
972                 };
973                 inode->i_rdev = MKDEV(major, minor);
974         } else
975                 inode->i_rdev = 0;
976
977         inode->i_size = stat->length;
978
979         inode->i_blocks =
980             (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
981 }
982
983 /**
984  * v9fs_qid2ino - convert qid into inode number
985  * @qid: qid to hash
986  *
987  * BUG: potential for inode number collisions?
988  */
989
990 ino_t v9fs_qid2ino(struct v9fs_qid *qid)
991 {
992         u64 path = qid->path + 2;
993         ino_t i = 0;
994
995         if (sizeof(ino_t) == sizeof(path))
996                 memcpy(&i, &path, sizeof(ino_t));
997         else
998                 i = (ino_t) (path ^ (path >> 32));
999
1000         return i;
1001 }
1002
1003 /**
1004  * v9fs_readlink - read a symlink's location (internal version)
1005  * @dentry: dentry for symlink
1006  * @buffer: buffer to load symlink location into
1007  * @buflen: length of buffer
1008  *
1009  */
1010
1011 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1012 {
1013         int retval = -EPERM;
1014
1015         struct v9fs_fcall *fcall = NULL;
1016         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
1017         struct v9fs_fid *fid = v9fs_fid_clone(dentry);
1018
1019         if(IS_ERR(fid))
1020                 return PTR_ERR(fid);
1021
1022         if (!v9ses->extended) {
1023                 retval = -EBADF;
1024                 dprintk(DEBUG_ERROR, "not extended\n");
1025                 goto ClunkFid;
1026         }
1027
1028         dprintk(DEBUG_VFS, " %s\n", dentry->d_name.name);
1029         retval = v9fs_t_stat(v9ses, fid->fid, &fcall);
1030
1031         if (retval < 0) {
1032                 dprintk(DEBUG_ERROR, "stat error\n");
1033                 goto FreeFcall;
1034         }
1035
1036         if (!fcall) {
1037                 retval = -EIO;
1038                 goto ClunkFid;
1039         }
1040
1041         if (!(fcall->params.rstat.stat.mode & V9FS_DMSYMLINK)) {
1042                 retval = -EINVAL;
1043                 goto FreeFcall;
1044         }
1045
1046         /* copy extension buffer into buffer */
1047         if (fcall->params.rstat.stat.extension.len < buflen)
1048                 buflen = fcall->params.rstat.stat.extension.len + 1;
1049
1050         memmove(buffer, fcall->params.rstat.stat.extension.str, buflen - 1);
1051         buffer[buflen-1] = 0;
1052
1053         dprintk(DEBUG_ERROR, "%s -> %.*s (%s)\n", dentry->d_name.name, fcall->params.rstat.stat.extension.len,
1054                 fcall->params.rstat.stat.extension.str, buffer);
1055         retval = buflen;
1056
1057 FreeFcall:
1058         kfree(fcall);
1059
1060 ClunkFid:
1061         v9fs_fid_clunk(v9ses, fid);
1062
1063         return retval;
1064 }
1065
1066 /**
1067  * v9fs_vfs_readlink - read a symlink's location
1068  * @dentry: dentry for symlink
1069  * @buf: buffer to load symlink location into
1070  * @buflen: length of buffer
1071  *
1072  */
1073
1074 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
1075                              int buflen)
1076 {
1077         int retval;
1078         int ret;
1079         char *link = __getname();
1080
1081         if (unlikely(!link))
1082                 return -ENOMEM;
1083
1084         if (buflen > PATH_MAX)
1085                 buflen = PATH_MAX;
1086
1087         dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
1088
1089         retval = v9fs_readlink(dentry, link, buflen);
1090
1091         if (retval > 0) {
1092                 if ((ret = copy_to_user(buffer, link, retval)) != 0) {
1093                         dprintk(DEBUG_ERROR, "problem copying to user: %d\n",
1094                                 ret);
1095                         retval = ret;
1096                 }
1097         }
1098
1099         __putname(link);
1100         return retval;
1101 }
1102
1103 /**
1104  * v9fs_vfs_follow_link - follow a symlink path
1105  * @dentry: dentry for symlink
1106  * @nd: nameidata
1107  *
1108  */
1109
1110 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1111 {
1112         int len = 0;
1113         char *link = __getname();
1114
1115         dprintk(DEBUG_VFS, "%s n", dentry->d_name.name);
1116
1117         if (!link)
1118                 link = ERR_PTR(-ENOMEM);
1119         else {
1120                 len = v9fs_readlink(dentry, link, PATH_MAX);
1121
1122                 if (len < 0) {
1123                         __putname(link);
1124                         link = ERR_PTR(len);
1125                 } else
1126                         link[len] = 0;
1127         }
1128         nd_set_link(nd, link);
1129
1130         return NULL;
1131 }
1132
1133 /**
1134  * v9fs_vfs_put_link - release a symlink path
1135  * @dentry: dentry for symlink
1136  * @nd: nameidata
1137  *
1138  */
1139
1140 static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1141 {
1142         char *s = nd_get_link(nd);
1143
1144         dprintk(DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1145         if (!IS_ERR(s))
1146                 __putname(s);
1147 }
1148
1149 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1150         int mode, const char *extension)
1151 {
1152         int err;
1153         u32 fid, perm;
1154         struct v9fs_session_info *v9ses;
1155         struct v9fs_fid *dfid, *vfid = NULL;
1156         struct inode *inode = NULL;
1157
1158         v9ses = v9fs_inode2v9ses(dir);
1159         if (!v9ses->extended) {
1160                 dprintk(DEBUG_ERROR, "not extended\n");
1161                 return -EPERM;
1162         }
1163
1164         dfid = v9fs_fid_clone(dentry->d_parent);
1165         if(IS_ERR(dfid)) {
1166                 err = PTR_ERR(dfid);
1167                 goto error;
1168         }
1169
1170         perm = unixmode2p9mode(v9ses, mode);
1171
1172         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
1173                 perm, V9FS_OREAD, (char *) extension, &fid, NULL, NULL);
1174
1175         if (err)
1176                 goto clunk_dfid;
1177
1178         err = v9fs_t_clunk(v9ses, fid);
1179         if (err)
1180                 goto clunk_dfid;
1181
1182         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
1183         if (IS_ERR(vfid)) {
1184                 err = PTR_ERR(vfid);
1185                 vfid = NULL;
1186                 goto clunk_dfid;
1187         }
1188
1189         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
1190         if (IS_ERR(inode)) {
1191                 err = PTR_ERR(inode);
1192                 inode = NULL;
1193                 goto free_vfid;
1194         }
1195
1196         if(v9ses->cache)
1197                 dentry->d_op = &v9fs_cached_dentry_operations;
1198         else
1199                 dentry->d_op = &v9fs_dentry_operations;
1200         d_instantiate(dentry, inode);
1201         return 0;
1202
1203 free_vfid:
1204         v9fs_fid_destroy(vfid);
1205
1206 clunk_dfid:
1207         v9fs_fid_clunk(v9ses, dfid);
1208
1209 error:
1210         return err;
1211
1212 }
1213
1214 /**
1215  * v9fs_vfs_symlink - helper function to create symlinks
1216  * @dir: directory inode containing symlink
1217  * @dentry: dentry for symlink
1218  * @symname: symlink data
1219  *
1220  * See 9P2000.u RFC for more information
1221  *
1222  */
1223
1224 static int
1225 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1226 {
1227         dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1228                 symname);
1229
1230         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1231 }
1232
1233 /**
1234  * v9fs_vfs_link - create a hardlink
1235  * @old_dentry: dentry for file to link to
1236  * @dir: inode destination for new link
1237  * @dentry: dentry for link
1238  *
1239  */
1240
1241 /* XXX - lots of code dup'd from symlink and creates,
1242  * figure out a better reuse strategy
1243  */
1244
1245 static int
1246 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1247               struct dentry *dentry)
1248 {
1249         int retval;
1250         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1251         struct v9fs_fid *oldfid;
1252         char *name;
1253
1254         dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1255                 old_dentry->d_name.name);
1256
1257         oldfid = v9fs_fid_clone(old_dentry);
1258         if(IS_ERR(oldfid))
1259                 return PTR_ERR(oldfid);
1260
1261         name = __getname();
1262         if (unlikely(!name)) {
1263                 retval = -ENOMEM;
1264                 goto clunk_fid;
1265         }
1266
1267         sprintf(name, "%d\n", oldfid->fid);
1268         retval = v9fs_vfs_mkspecial(dir, dentry, V9FS_DMLINK, name);
1269         __putname(name);
1270
1271 clunk_fid:
1272         v9fs_fid_clunk(v9ses, oldfid);
1273         return retval;
1274 }
1275
1276 /**
1277  * v9fs_vfs_mknod - create a special file
1278  * @dir: inode destination for new link
1279  * @dentry: dentry for file
1280  * @mode: mode for creation
1281  * @dev_t: device associated with special file
1282  *
1283  */
1284
1285 static int
1286 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1287 {
1288         int retval;
1289         char *name;
1290
1291         dprintk(DEBUG_VFS, " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1292                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1293
1294         if (!new_valid_dev(rdev))
1295                 return -EINVAL;
1296
1297         name = __getname();
1298         if (!name)
1299                 return -ENOMEM;
1300         /* build extension */
1301         if (S_ISBLK(mode))
1302                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1303         else if (S_ISCHR(mode))
1304                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1305         else if (S_ISFIFO(mode))
1306                 *name = 0;
1307         else {
1308                 __putname(name);
1309                 return -EINVAL;
1310         }
1311
1312         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1313         __putname(name);
1314
1315         return retval;
1316 }
1317
1318 static const struct inode_operations v9fs_dir_inode_operations_ext = {
1319         .create = v9fs_vfs_create,
1320         .lookup = v9fs_vfs_lookup,
1321         .symlink = v9fs_vfs_symlink,
1322         .link = v9fs_vfs_link,
1323         .unlink = v9fs_vfs_unlink,
1324         .mkdir = v9fs_vfs_mkdir,
1325         .rmdir = v9fs_vfs_rmdir,
1326         .mknod = v9fs_vfs_mknod,
1327         .rename = v9fs_vfs_rename,
1328         .readlink = v9fs_vfs_readlink,
1329         .getattr = v9fs_vfs_getattr,
1330         .setattr = v9fs_vfs_setattr,
1331 };
1332
1333 static const struct inode_operations v9fs_dir_inode_operations = {
1334         .create = v9fs_vfs_create,
1335         .lookup = v9fs_vfs_lookup,
1336         .unlink = v9fs_vfs_unlink,
1337         .mkdir = v9fs_vfs_mkdir,
1338         .rmdir = v9fs_vfs_rmdir,
1339         .mknod = v9fs_vfs_mknod,
1340         .rename = v9fs_vfs_rename,
1341         .getattr = v9fs_vfs_getattr,
1342         .setattr = v9fs_vfs_setattr,
1343 };
1344
1345 static const struct inode_operations v9fs_file_inode_operations = {
1346         .getattr = v9fs_vfs_getattr,
1347         .setattr = v9fs_vfs_setattr,
1348 };
1349
1350 static const struct inode_operations v9fs_symlink_inode_operations = {
1351         .readlink = v9fs_vfs_readlink,
1352         .follow_link = v9fs_vfs_follow_link,
1353         .put_link = v9fs_vfs_put_link,
1354         .getattr = v9fs_vfs_getattr,
1355         .setattr = v9fs_vfs_setattr,
1356 };