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Linux/fs/9p/vfs_inode.c

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  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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 27 
 28 #include <linux/module.h>
 29 #include <linux/errno.h>
 30 #include <linux/fs.h>
 31 #include <linux/file.h>
 32 #include <linux/pagemap.h>
 33 #include <linux/stat.h>
 34 #include <linux/string.h>
 35 #include <linux/inet.h>
 36 #include <linux/namei.h>
 37 #include <linux/idr.h>
 38 #include <linux/sched.h>
 39 #include <linux/slab.h>
 40 #include <linux/xattr.h>
 41 #include <linux/posix_acl.h>
 42 #include <net/9p/9p.h>
 43 #include <net/9p/client.h>
 44 
 45 #include "v9fs.h"
 46 #include "v9fs_vfs.h"
 47 #include "fid.h"
 48 #include "cache.h"
 49 #include "xattr.h"
 50 #include "acl.h"
 51 
 52 static const struct inode_operations v9fs_dir_inode_operations;
 53 static const struct inode_operations v9fs_dir_inode_operations_dotu;
 54 static const struct inode_operations v9fs_file_inode_operations;
 55 static const struct inode_operations v9fs_symlink_inode_operations;
 56 
 57 /**
 58  * unixmode2p9mode - convert unix mode bits to plan 9
 59  * @v9ses: v9fs session information
 60  * @mode: mode to convert
 61  *
 62  */
 63 
 64 static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
 65 {
 66         int res;
 67         res = mode & 0777;
 68         if (S_ISDIR(mode))
 69                 res |= P9_DMDIR;
 70         if (v9fs_proto_dotu(v9ses)) {
 71                 if (v9ses->nodev == 0) {
 72                         if (S_ISSOCK(mode))
 73                                 res |= P9_DMSOCKET;
 74                         if (S_ISFIFO(mode))
 75                                 res |= P9_DMNAMEDPIPE;
 76                         if (S_ISBLK(mode))
 77                                 res |= P9_DMDEVICE;
 78                         if (S_ISCHR(mode))
 79                                 res |= P9_DMDEVICE;
 80                 }
 81 
 82                 if ((mode & S_ISUID) == S_ISUID)
 83                         res |= P9_DMSETUID;
 84                 if ((mode & S_ISGID) == S_ISGID)
 85                         res |= P9_DMSETGID;
 86                 if ((mode & S_ISVTX) == S_ISVTX)
 87                         res |= P9_DMSETVTX;
 88         }
 89         return res;
 90 }
 91 
 92 /**
 93  * p9mode2perm- convert plan9 mode bits to unix permission bits
 94  * @v9ses: v9fs session information
 95  * @stat: p9_wstat from which mode need to be derived
 96  *
 97  */
 98 static int p9mode2perm(struct v9fs_session_info *v9ses,
 99                        struct p9_wstat *stat)
100 {
101         int res;
102         int mode = stat->mode;
103 
104         res = mode & S_IALLUGO;
105         if (v9fs_proto_dotu(v9ses)) {
106                 if ((mode & P9_DMSETUID) == P9_DMSETUID)
107                         res |= S_ISUID;
108 
109                 if ((mode & P9_DMSETGID) == P9_DMSETGID)
110                         res |= S_ISGID;
111 
112                 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
113                         res |= S_ISVTX;
114         }
115         return res;
116 }
117 
118 /**
119  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
120  * @v9ses: v9fs session information
121  * @stat: p9_wstat from which mode need to be derived
122  * @rdev: major number, minor number in case of device files.
123  *
124  */
125 static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
126                                struct p9_wstat *stat, dev_t *rdev)
127 {
128         int res;
129         u32 mode = stat->mode;
130 
131         *rdev = 0;
132         res = p9mode2perm(v9ses, stat);
133 
134         if ((mode & P9_DMDIR) == P9_DMDIR)
135                 res |= S_IFDIR;
136         else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
137                 res |= S_IFLNK;
138         else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
139                  && (v9ses->nodev == 0))
140                 res |= S_IFSOCK;
141         else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
142                  && (v9ses->nodev == 0))
143                 res |= S_IFIFO;
144         else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
145                  && (v9ses->nodev == 0)) {
146                 char type = 0, ext[32];
147                 int major = -1, minor = -1;
148 
149                 strlcpy(ext, stat->extension, sizeof(ext));
150                 sscanf(ext, "%c %i %i", &type, &major, &minor);
151                 switch (type) {
152                 case 'c':
153                         res |= S_IFCHR;
154                         break;
155                 case 'b':
156                         res |= S_IFBLK;
157                         break;
158                 default:
159                         p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
160                                  type, stat->extension);
161                 };
162                 *rdev = MKDEV(major, minor);
163         } else
164                 res |= S_IFREG;
165 
166         return res;
167 }
168 
169 /**
170  * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
171  * @uflags: flags to convert
172  * @extended: if .u extensions are active
173  */
174 
175 int v9fs_uflags2omode(int uflags, int extended)
176 {
177         int ret;
178 
179         ret = 0;
180         switch (uflags&3) {
181         default:
182         case O_RDONLY:
183                 ret = P9_OREAD;
184                 break;
185 
186         case O_WRONLY:
187                 ret = P9_OWRITE;
188                 break;
189 
190         case O_RDWR:
191                 ret = P9_ORDWR;
192                 break;
193         }
194 
195         if (extended) {
196                 if (uflags & O_EXCL)
197                         ret |= P9_OEXCL;
198 
199                 if (uflags & O_APPEND)
200                         ret |= P9_OAPPEND;
201         }
202 
203         return ret;
204 }
205 
206 /**
207  * v9fs_blank_wstat - helper function to setup a 9P stat structure
208  * @wstat: structure to initialize
209  *
210  */
211 
212 void
213 v9fs_blank_wstat(struct p9_wstat *wstat)
214 {
215         wstat->type = ~0;
216         wstat->dev = ~0;
217         wstat->qid.type = ~0;
218         wstat->qid.version = ~0;
219         *((long long *)&wstat->qid.path) = ~0;
220         wstat->mode = ~0;
221         wstat->atime = ~0;
222         wstat->mtime = ~0;
223         wstat->length = ~0;
224         wstat->name = NULL;
225         wstat->uid = NULL;
226         wstat->gid = NULL;
227         wstat->muid = NULL;
228         wstat->n_uid = INVALID_UID;
229         wstat->n_gid = INVALID_GID;
230         wstat->n_muid = INVALID_UID;
231         wstat->extension = NULL;
232 }
233 
234 /**
235  * v9fs_alloc_inode - helper function to allocate an inode
236  *
237  */
238 struct inode *v9fs_alloc_inode(struct super_block *sb)
239 {
240         struct v9fs_inode *v9inode;
241         v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
242                                                         GFP_KERNEL);
243         if (!v9inode)
244                 return NULL;
245 #ifdef CONFIG_9P_FSCACHE
246         v9inode->fscache = NULL;
247         mutex_init(&v9inode->fscache_lock);
248 #endif
249         v9inode->writeback_fid = NULL;
250         v9inode->cache_validity = 0;
251         mutex_init(&v9inode->v_mutex);
252         return &v9inode->vfs_inode;
253 }
254 
255 /**
256  * v9fs_destroy_inode - destroy an inode
257  *
258  */
259 
260 static void v9fs_i_callback(struct rcu_head *head)
261 {
262         struct inode *inode = container_of(head, struct inode, i_rcu);
263         kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
264 }
265 
266 void v9fs_destroy_inode(struct inode *inode)
267 {
268         call_rcu(&inode->i_rcu, v9fs_i_callback);
269 }
270 
271 int v9fs_init_inode(struct v9fs_session_info *v9ses,
272                     struct inode *inode, umode_t mode, dev_t rdev)
273 {
274         int err = 0;
275 
276         inode_init_owner(inode, NULL, mode);
277         inode->i_blocks = 0;
278         inode->i_rdev = rdev;
279         inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
280         inode->i_mapping->a_ops = &v9fs_addr_operations;
281 
282         switch (mode & S_IFMT) {
283         case S_IFIFO:
284         case S_IFBLK:
285         case S_IFCHR:
286         case S_IFSOCK:
287                 if (v9fs_proto_dotl(v9ses)) {
288                         inode->i_op = &v9fs_file_inode_operations_dotl;
289                 } else if (v9fs_proto_dotu(v9ses)) {
290                         inode->i_op = &v9fs_file_inode_operations;
291                 } else {
292                         p9_debug(P9_DEBUG_ERROR,
293                                  "special files without extended mode\n");
294                         err = -EINVAL;
295                         goto error;
296                 }
297                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
298                 break;
299         case S_IFREG:
300                 if (v9fs_proto_dotl(v9ses)) {
301                         inode->i_op = &v9fs_file_inode_operations_dotl;
302                         if (v9ses->cache == CACHE_LOOSE ||
303                             v9ses->cache == CACHE_FSCACHE)
304                                 inode->i_fop =
305                                         &v9fs_cached_file_operations_dotl;
306                         else if (v9ses->cache == CACHE_MMAP)
307                                 inode->i_fop = &v9fs_mmap_file_operations_dotl;
308                         else
309                                 inode->i_fop = &v9fs_file_operations_dotl;
310                 } else {
311                         inode->i_op = &v9fs_file_inode_operations;
312                         if (v9ses->cache == CACHE_LOOSE ||
313                             v9ses->cache == CACHE_FSCACHE)
314                                 inode->i_fop =
315                                         &v9fs_cached_file_operations;
316                         else if (v9ses->cache == CACHE_MMAP)
317                                 inode->i_fop = &v9fs_mmap_file_operations;
318                         else
319                                 inode->i_fop = &v9fs_file_operations;
320                 }
321 
322                 break;
323         case S_IFLNK:
324                 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
325                         p9_debug(P9_DEBUG_ERROR,
326                                  "extended modes used with legacy protocol\n");
327                         err = -EINVAL;
328                         goto error;
329                 }
330 
331                 if (v9fs_proto_dotl(v9ses))
332                         inode->i_op = &v9fs_symlink_inode_operations_dotl;
333                 else
334                         inode->i_op = &v9fs_symlink_inode_operations;
335 
336                 break;
337         case S_IFDIR:
338                 inc_nlink(inode);
339                 if (v9fs_proto_dotl(v9ses))
340                         inode->i_op = &v9fs_dir_inode_operations_dotl;
341                 else if (v9fs_proto_dotu(v9ses))
342                         inode->i_op = &v9fs_dir_inode_operations_dotu;
343                 else
344                         inode->i_op = &v9fs_dir_inode_operations;
345 
346                 if (v9fs_proto_dotl(v9ses))
347                         inode->i_fop = &v9fs_dir_operations_dotl;
348                 else
349                         inode->i_fop = &v9fs_dir_operations;
350 
351                 break;
352         default:
353                 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
354                          mode, mode & S_IFMT);
355                 err = -EINVAL;
356                 goto error;
357         }
358 error:
359         return err;
360 
361 }
362 
363 /**
364  * v9fs_get_inode - helper function to setup an inode
365  * @sb: superblock
366  * @mode: mode to setup inode with
367  *
368  */
369 
370 struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
371 {
372         int err;
373         struct inode *inode;
374         struct v9fs_session_info *v9ses = sb->s_fs_info;
375 
376         p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
377 
378         inode = new_inode(sb);
379         if (!inode) {
380                 pr_warn("%s (%d): Problem allocating inode\n",
381                         __func__, task_pid_nr(current));
382                 return ERR_PTR(-ENOMEM);
383         }
384         err = v9fs_init_inode(v9ses, inode, mode, rdev);
385         if (err) {
386                 iput(inode);
387                 return ERR_PTR(err);
388         }
389         return inode;
390 }
391 
392 /*
393 static struct v9fs_fid*
394 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
395 {
396         int err;
397         int nfid;
398         struct v9fs_fid *ret;
399         struct v9fs_fcall *fcall;
400 
401         nfid = v9fs_get_idpool(&v9ses->fidpool);
402         if (nfid < 0) {
403                 eprintk(KERN_WARNING, "no free fids available\n");
404                 return ERR_PTR(-ENOSPC);
405         }
406 
407         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
408                 &fcall);
409 
410         if (err < 0) {
411                 if (fcall && fcall->id == RWALK)
412                         goto clunk_fid;
413 
414                 PRINT_FCALL_ERROR("walk error", fcall);
415                 v9fs_put_idpool(nfid, &v9ses->fidpool);
416                 goto error;
417         }
418 
419         kfree(fcall);
420         fcall = NULL;
421         ret = v9fs_fid_create(v9ses, nfid);
422         if (!ret) {
423                 err = -ENOMEM;
424                 goto clunk_fid;
425         }
426 
427         err = v9fs_fid_insert(ret, dentry);
428         if (err < 0) {
429                 v9fs_fid_destroy(ret);
430                 goto clunk_fid;
431         }
432 
433         return ret;
434 
435 clunk_fid:
436         v9fs_t_clunk(v9ses, nfid);
437 
438 error:
439         kfree(fcall);
440         return ERR_PTR(err);
441 }
442 */
443 
444 
445 /**
446  * v9fs_clear_inode - release an inode
447  * @inode: inode to release
448  *
449  */
450 void v9fs_evict_inode(struct inode *inode)
451 {
452         struct v9fs_inode *v9inode = V9FS_I(inode);
453 
454         truncate_inode_pages_final(&inode->i_data);
455         clear_inode(inode);
456         filemap_fdatawrite(&inode->i_data);
457 
458         v9fs_cache_inode_put_cookie(inode);
459         /* clunk the fid stashed in writeback_fid */
460         if (v9inode->writeback_fid) {
461                 p9_client_clunk(v9inode->writeback_fid);
462                 v9inode->writeback_fid = NULL;
463         }
464 }
465 
466 static int v9fs_test_inode(struct inode *inode, void *data)
467 {
468         int umode;
469         dev_t rdev;
470         struct v9fs_inode *v9inode = V9FS_I(inode);
471         struct p9_wstat *st = (struct p9_wstat *)data;
472         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
473 
474         umode = p9mode2unixmode(v9ses, st, &rdev);
475         /* don't match inode of different type */
476         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
477                 return 0;
478 
479         /* compare qid details */
480         if (memcmp(&v9inode->qid.version,
481                    &st->qid.version, sizeof(v9inode->qid.version)))
482                 return 0;
483 
484         if (v9inode->qid.type != st->qid.type)
485                 return 0;
486         return 1;
487 }
488 
489 static int v9fs_test_new_inode(struct inode *inode, void *data)
490 {
491         return 0;
492 }
493 
494 static int v9fs_set_inode(struct inode *inode,  void *data)
495 {
496         struct v9fs_inode *v9inode = V9FS_I(inode);
497         struct p9_wstat *st = (struct p9_wstat *)data;
498 
499         memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
500         return 0;
501 }
502 
503 static struct inode *v9fs_qid_iget(struct super_block *sb,
504                                    struct p9_qid *qid,
505                                    struct p9_wstat *st,
506                                    int new)
507 {
508         dev_t rdev;
509         int retval;
510         umode_t umode;
511         unsigned long i_ino;
512         struct inode *inode;
513         struct v9fs_session_info *v9ses = sb->s_fs_info;
514         int (*test)(struct inode *, void *);
515 
516         if (new)
517                 test = v9fs_test_new_inode;
518         else
519                 test = v9fs_test_inode;
520 
521         i_ino = v9fs_qid2ino(qid);
522         inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
523         if (!inode)
524                 return ERR_PTR(-ENOMEM);
525         if (!(inode->i_state & I_NEW))
526                 return inode;
527         /*
528          * initialize the inode with the stat info
529          * FIXME!! we may need support for stale inodes
530          * later.
531          */
532         inode->i_ino = i_ino;
533         umode = p9mode2unixmode(v9ses, st, &rdev);
534         retval = v9fs_init_inode(v9ses, inode, umode, rdev);
535         if (retval)
536                 goto error;
537 
538         v9fs_stat2inode(st, inode, sb);
539         v9fs_cache_inode_get_cookie(inode);
540         unlock_new_inode(inode);
541         return inode;
542 error:
543         iget_failed(inode);
544         return ERR_PTR(retval);
545 
546 }
547 
548 struct inode *
549 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
550                     struct super_block *sb, int new)
551 {
552         struct p9_wstat *st;
553         struct inode *inode = NULL;
554 
555         st = p9_client_stat(fid);
556         if (IS_ERR(st))
557                 return ERR_CAST(st);
558 
559         inode = v9fs_qid_iget(sb, &st->qid, st, new);
560         p9stat_free(st);
561         kfree(st);
562         return inode;
563 }
564 
565 /**
566  * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
567  * plan 9 AT flag.
568  * @flags: flags to convert
569  */
570 static int v9fs_at_to_dotl_flags(int flags)
571 {
572         int rflags = 0;
573         if (flags & AT_REMOVEDIR)
574                 rflags |= P9_DOTL_AT_REMOVEDIR;
575         return rflags;
576 }
577 
578 /**
579  * v9fs_remove - helper function to remove files and directories
580  * @dir: directory inode that is being deleted
581  * @dentry:  dentry that is being deleted
582  * @flags: removing a directory
583  *
584  */
585 
586 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
587 {
588         struct inode *inode;
589         int retval = -EOPNOTSUPP;
590         struct p9_fid *v9fid, *dfid;
591         struct v9fs_session_info *v9ses;
592 
593         p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
594                  dir, dentry, flags);
595 
596         v9ses = v9fs_inode2v9ses(dir);
597         inode = d_inode(dentry);
598         dfid = v9fs_parent_fid(dentry);
599         if (IS_ERR(dfid)) {
600                 retval = PTR_ERR(dfid);
601                 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
602                 return retval;
603         }
604         if (v9fs_proto_dotl(v9ses))
605                 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
606                                             v9fs_at_to_dotl_flags(flags));
607         if (retval == -EOPNOTSUPP) {
608                 /* Try the one based on path */
609                 v9fid = v9fs_fid_clone(dentry);
610                 if (IS_ERR(v9fid))
611                         return PTR_ERR(v9fid);
612                 retval = p9_client_remove(v9fid);
613         }
614         if (!retval) {
615                 /*
616                  * directories on unlink should have zero
617                  * link count
618                  */
619                 if (flags & AT_REMOVEDIR) {
620                         clear_nlink(inode);
621                         drop_nlink(dir);
622                 } else
623                         drop_nlink(inode);
624 
625                 v9fs_invalidate_inode_attr(inode);
626                 v9fs_invalidate_inode_attr(dir);
627         }
628         return retval;
629 }
630 
631 /**
632  * v9fs_create - Create a file
633  * @v9ses: session information
634  * @dir: directory that dentry is being created in
635  * @dentry:  dentry that is being created
636  * @extension: 9p2000.u extension string to support devices, etc.
637  * @perm: create permissions
638  * @mode: open mode
639  *
640  */
641 static struct p9_fid *
642 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
643                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
644 {
645         int err;
646         char *name;
647         struct p9_fid *dfid, *ofid, *fid;
648         struct inode *inode;
649 
650         p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
651 
652         err = 0;
653         ofid = NULL;
654         fid = NULL;
655         name = (char *) dentry->d_name.name;
656         dfid = v9fs_parent_fid(dentry);
657         if (IS_ERR(dfid)) {
658                 err = PTR_ERR(dfid);
659                 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
660                 return ERR_PTR(err);
661         }
662 
663         /* clone a fid to use for creation */
664         ofid = clone_fid(dfid);
665         if (IS_ERR(ofid)) {
666                 err = PTR_ERR(ofid);
667                 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
668                 return ERR_PTR(err);
669         }
670 
671         err = p9_client_fcreate(ofid, name, perm, mode, extension);
672         if (err < 0) {
673                 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
674                 goto error;
675         }
676 
677         if (!(perm & P9_DMLINK)) {
678                 /* now walk from the parent so we can get unopened fid */
679                 fid = p9_client_walk(dfid, 1, &name, 1);
680                 if (IS_ERR(fid)) {
681                         err = PTR_ERR(fid);
682                         p9_debug(P9_DEBUG_VFS,
683                                    "p9_client_walk failed %d\n", err);
684                         fid = NULL;
685                         goto error;
686                 }
687                 /*
688                  * instantiate inode and assign the unopened fid to the dentry
689                  */
690                 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
691                 if (IS_ERR(inode)) {
692                         err = PTR_ERR(inode);
693                         p9_debug(P9_DEBUG_VFS,
694                                    "inode creation failed %d\n", err);
695                         goto error;
696                 }
697                 v9fs_fid_add(dentry, fid);
698                 d_instantiate(dentry, inode);
699         }
700         return ofid;
701 error:
702         if (ofid)
703                 p9_client_clunk(ofid);
704 
705         if (fid)
706                 p9_client_clunk(fid);
707 
708         return ERR_PTR(err);
709 }
710 
711 /**
712  * v9fs_vfs_create - VFS hook to create a regular file
713  *
714  * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
715  * for mknod(2).
716  *
717  * @dir: directory inode that is being created
718  * @dentry:  dentry that is being deleted
719  * @mode: create permissions
720  *
721  */
722 
723 static int
724 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
725                 bool excl)
726 {
727         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
728         u32 perm = unixmode2p9mode(v9ses, mode);
729         struct p9_fid *fid;
730 
731         /* P9_OEXCL? */
732         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
733         if (IS_ERR(fid))
734                 return PTR_ERR(fid);
735 
736         v9fs_invalidate_inode_attr(dir);
737         p9_client_clunk(fid);
738 
739         return 0;
740 }
741 
742 /**
743  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
744  * @dir:  inode that is being unlinked
745  * @dentry: dentry that is being unlinked
746  * @mode: mode for new directory
747  *
748  */
749 
750 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
751 {
752         int err;
753         u32 perm;
754         struct p9_fid *fid;
755         struct v9fs_session_info *v9ses;
756 
757         p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
758         err = 0;
759         v9ses = v9fs_inode2v9ses(dir);
760         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
761         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
762         if (IS_ERR(fid)) {
763                 err = PTR_ERR(fid);
764                 fid = NULL;
765         } else {
766                 inc_nlink(dir);
767                 v9fs_invalidate_inode_attr(dir);
768         }
769 
770         if (fid)
771                 p9_client_clunk(fid);
772 
773         return err;
774 }
775 
776 /**
777  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
778  * @dir:  inode that is being walked from
779  * @dentry: dentry that is being walked to?
780  * @flags: lookup flags (unused)
781  *
782  */
783 
784 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
785                                       unsigned int flags)
786 {
787         struct dentry *res;
788         struct v9fs_session_info *v9ses;
789         struct p9_fid *dfid, *fid;
790         struct inode *inode;
791         char *name;
792 
793         p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
794                  dir, dentry, dentry, flags);
795 
796         if (dentry->d_name.len > NAME_MAX)
797                 return ERR_PTR(-ENAMETOOLONG);
798 
799         v9ses = v9fs_inode2v9ses(dir);
800         /* We can walk d_parent because we hold the dir->i_mutex */
801         dfid = v9fs_parent_fid(dentry);
802         if (IS_ERR(dfid))
803                 return ERR_CAST(dfid);
804 
805         name = (char *) dentry->d_name.name;
806         fid = p9_client_walk(dfid, 1, &name, 1);
807         if (IS_ERR(fid)) {
808                 if (fid == ERR_PTR(-ENOENT)) {
809                         d_add(dentry, NULL);
810                         return NULL;
811                 }
812                 return ERR_CAST(fid);
813         }
814         /*
815          * Make sure we don't use a wrong inode due to parallel
816          * unlink. For cached mode create calls request for new
817          * inode. But with cache disabled, lookup should do this.
818          */
819         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
820                 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
821         else
822                 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
823         if (IS_ERR(inode)) {
824                 p9_client_clunk(fid);
825                 return ERR_CAST(inode);
826         }
827         /*
828          * If we had a rename on the server and a parallel lookup
829          * for the new name, then make sure we instantiate with
830          * the new name. ie look up for a/b, while on server somebody
831          * moved b under k and client parallely did a lookup for
832          * k/b.
833          */
834         res = d_splice_alias(inode, dentry);
835         if (!res)
836                 v9fs_fid_add(dentry, fid);
837         else if (!IS_ERR(res))
838                 v9fs_fid_add(res, fid);
839         else
840                 p9_client_clunk(fid);
841         return res;
842 }
843 
844 static int
845 v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
846                      struct file *file, unsigned flags, umode_t mode,
847                      int *opened)
848 {
849         int err;
850         u32 perm;
851         struct v9fs_inode *v9inode;
852         struct v9fs_session_info *v9ses;
853         struct p9_fid *fid, *inode_fid;
854         struct dentry *res = NULL;
855 
856         if (d_in_lookup(dentry)) {
857                 res = v9fs_vfs_lookup(dir, dentry, 0);
858                 if (IS_ERR(res))
859                         return PTR_ERR(res);
860 
861                 if (res)
862                         dentry = res;
863         }
864 
865         /* Only creates */
866         if (!(flags & O_CREAT) || d_really_is_positive(dentry))
867                 return finish_no_open(file, res);
868 
869         err = 0;
870 
871         v9ses = v9fs_inode2v9ses(dir);
872         perm = unixmode2p9mode(v9ses, mode);
873         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
874                                 v9fs_uflags2omode(flags,
875                                                 v9fs_proto_dotu(v9ses)));
876         if (IS_ERR(fid)) {
877                 err = PTR_ERR(fid);
878                 fid = NULL;
879                 goto error;
880         }
881 
882         v9fs_invalidate_inode_attr(dir);
883         v9inode = V9FS_I(d_inode(dentry));
884         mutex_lock(&v9inode->v_mutex);
885         if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
886             !v9inode->writeback_fid &&
887             ((flags & O_ACCMODE) != O_RDONLY)) {
888                 /*
889                  * clone a fid and add it to writeback_fid
890                  * we do it during open time instead of
891                  * page dirty time via write_begin/page_mkwrite
892                  * because we want write after unlink usecase
893                  * to work.
894                  */
895                 inode_fid = v9fs_writeback_fid(dentry);
896                 if (IS_ERR(inode_fid)) {
897                         err = PTR_ERR(inode_fid);
898                         mutex_unlock(&v9inode->v_mutex);
899                         goto error;
900                 }
901                 v9inode->writeback_fid = (void *) inode_fid;
902         }
903         mutex_unlock(&v9inode->v_mutex);
904         err = finish_open(file, dentry, generic_file_open, opened);
905         if (err)
906                 goto error;
907 
908         file->private_data = fid;
909         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
910                 v9fs_cache_inode_set_cookie(d_inode(dentry), file);
911 
912         *opened |= FILE_CREATED;
913 out:
914         dput(res);
915         return err;
916 
917 error:
918         if (fid)
919                 p9_client_clunk(fid);
920         goto out;
921 }
922 
923 /**
924  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
925  * @i:  inode that is being unlinked
926  * @d: dentry that is being unlinked
927  *
928  */
929 
930 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
931 {
932         return v9fs_remove(i, d, 0);
933 }
934 
935 /**
936  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
937  * @i:  inode that is being unlinked
938  * @d: dentry that is being unlinked
939  *
940  */
941 
942 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
943 {
944         return v9fs_remove(i, d, AT_REMOVEDIR);
945 }
946 
947 /**
948  * v9fs_vfs_rename - VFS hook to rename an inode
949  * @old_dir:  old dir inode
950  * @old_dentry: old dentry
951  * @new_dir: new dir inode
952  * @new_dentry: new dentry
953  *
954  */
955 
956 int
957 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
958                 struct inode *new_dir, struct dentry *new_dentry,
959                 unsigned int flags)
960 {
961         int retval;
962         struct inode *old_inode;
963         struct inode *new_inode;
964         struct v9fs_session_info *v9ses;
965         struct p9_fid *oldfid;
966         struct p9_fid *olddirfid;
967         struct p9_fid *newdirfid;
968         struct p9_wstat wstat;
969 
970         if (flags)
971                 return -EINVAL;
972 
973         p9_debug(P9_DEBUG_VFS, "\n");
974         retval = 0;
975         old_inode = d_inode(old_dentry);
976         new_inode = d_inode(new_dentry);
977         v9ses = v9fs_inode2v9ses(old_inode);
978         oldfid = v9fs_fid_lookup(old_dentry);
979         if (IS_ERR(oldfid))
980                 return PTR_ERR(oldfid);
981 
982         olddirfid = clone_fid(v9fs_parent_fid(old_dentry));
983         if (IS_ERR(olddirfid)) {
984                 retval = PTR_ERR(olddirfid);
985                 goto done;
986         }
987 
988         newdirfid = clone_fid(v9fs_parent_fid(new_dentry));
989         if (IS_ERR(newdirfid)) {
990                 retval = PTR_ERR(newdirfid);
991                 goto clunk_olddir;
992         }
993 
994         down_write(&v9ses->rename_sem);
995         if (v9fs_proto_dotl(v9ses)) {
996                 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
997                                             newdirfid, new_dentry->d_name.name);
998                 if (retval == -EOPNOTSUPP)
999                         retval = p9_client_rename(oldfid, newdirfid,
1000                                                   new_dentry->d_name.name);
1001                 if (retval != -EOPNOTSUPP)
1002                         goto clunk_newdir;
1003         }
1004         if (old_dentry->d_parent != new_dentry->d_parent) {
1005                 /*
1006                  * 9P .u can only handle file rename in the same directory
1007                  */
1008 
1009                 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
1010                 retval = -EXDEV;
1011                 goto clunk_newdir;
1012         }
1013         v9fs_blank_wstat(&wstat);
1014         wstat.muid = v9ses->uname;
1015         wstat.name = (char *) new_dentry->d_name.name;
1016         retval = p9_client_wstat(oldfid, &wstat);
1017 
1018 clunk_newdir:
1019         if (!retval) {
1020                 if (new_inode) {
1021                         if (S_ISDIR(new_inode->i_mode))
1022                                 clear_nlink(new_inode);
1023                         else
1024                                 drop_nlink(new_inode);
1025                 }
1026                 if (S_ISDIR(old_inode->i_mode)) {
1027                         if (!new_inode)
1028                                 inc_nlink(new_dir);
1029                         drop_nlink(old_dir);
1030                 }
1031                 v9fs_invalidate_inode_attr(old_inode);
1032                 v9fs_invalidate_inode_attr(old_dir);
1033                 v9fs_invalidate_inode_attr(new_dir);
1034 
1035                 /* successful rename */
1036                 d_move(old_dentry, new_dentry);
1037         }
1038         up_write(&v9ses->rename_sem);
1039         p9_client_clunk(newdirfid);
1040 
1041 clunk_olddir:
1042         p9_client_clunk(olddirfid);
1043 
1044 done:
1045         return retval;
1046 }
1047 
1048 /**
1049  * v9fs_vfs_getattr - retrieve file metadata
1050  * @mnt: mount information
1051  * @dentry: file to get attributes on
1052  * @stat: metadata structure to populate
1053  *
1054  */
1055 
1056 static int
1057 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1058                  struct kstat *stat)
1059 {
1060         struct v9fs_session_info *v9ses;
1061         struct p9_fid *fid;
1062         struct p9_wstat *st;
1063 
1064         p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1065         v9ses = v9fs_dentry2v9ses(dentry);
1066         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1067                 generic_fillattr(d_inode(dentry), stat);
1068                 return 0;
1069         }
1070         fid = v9fs_fid_lookup(dentry);
1071         if (IS_ERR(fid))
1072                 return PTR_ERR(fid);
1073 
1074         st = p9_client_stat(fid);
1075         if (IS_ERR(st))
1076                 return PTR_ERR(st);
1077 
1078         v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb);
1079         generic_fillattr(d_inode(dentry), stat);
1080 
1081         p9stat_free(st);
1082         kfree(st);
1083         return 0;
1084 }
1085 
1086 /**
1087  * v9fs_vfs_setattr - set file metadata
1088  * @dentry: file whose metadata to set
1089  * @iattr: metadata assignment structure
1090  *
1091  */
1092 
1093 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1094 {
1095         int retval;
1096         struct v9fs_session_info *v9ses;
1097         struct p9_fid *fid;
1098         struct p9_wstat wstat;
1099 
1100         p9_debug(P9_DEBUG_VFS, "\n");
1101         retval = setattr_prepare(dentry, iattr);
1102         if (retval)
1103                 return retval;
1104 
1105         retval = -EPERM;
1106         v9ses = v9fs_dentry2v9ses(dentry);
1107         fid = v9fs_fid_lookup(dentry);
1108         if(IS_ERR(fid))
1109                 return PTR_ERR(fid);
1110 
1111         v9fs_blank_wstat(&wstat);
1112         if (iattr->ia_valid & ATTR_MODE)
1113                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1114 
1115         if (iattr->ia_valid & ATTR_MTIME)
1116                 wstat.mtime = iattr->ia_mtime.tv_sec;
1117 
1118         if (iattr->ia_valid & ATTR_ATIME)
1119                 wstat.atime = iattr->ia_atime.tv_sec;
1120 
1121         if (iattr->ia_valid & ATTR_SIZE)
1122                 wstat.length = iattr->ia_size;
1123 
1124         if (v9fs_proto_dotu(v9ses)) {
1125                 if (iattr->ia_valid & ATTR_UID)
1126                         wstat.n_uid = iattr->ia_uid;
1127 
1128                 if (iattr->ia_valid & ATTR_GID)
1129                         wstat.n_gid = iattr->ia_gid;
1130         }
1131 
1132         /* Write all dirty data */
1133         if (d_is_reg(dentry))
1134                 filemap_write_and_wait(d_inode(dentry)->i_mapping);
1135 
1136         retval = p9_client_wstat(fid, &wstat);
1137         if (retval < 0)
1138                 return retval;
1139 
1140         if ((iattr->ia_valid & ATTR_SIZE) &&
1141             iattr->ia_size != i_size_read(d_inode(dentry)))
1142                 truncate_setsize(d_inode(dentry), iattr->ia_size);
1143 
1144         v9fs_invalidate_inode_attr(d_inode(dentry));
1145 
1146         setattr_copy(d_inode(dentry), iattr);
1147         mark_inode_dirty(d_inode(dentry));
1148         return 0;
1149 }
1150 
1151 /**
1152  * v9fs_stat2inode - populate an inode structure with mistat info
1153  * @stat: Plan 9 metadata (mistat) structure
1154  * @inode: inode to populate
1155  * @sb: superblock of filesystem
1156  *
1157  */
1158 
1159 void
1160 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1161         struct super_block *sb)
1162 {
1163         umode_t mode;
1164         char ext[32];
1165         char tag_name[14];
1166         unsigned int i_nlink;
1167         struct v9fs_session_info *v9ses = sb->s_fs_info;
1168         struct v9fs_inode *v9inode = V9FS_I(inode);
1169 
1170         set_nlink(inode, 1);
1171 
1172         inode->i_atime.tv_sec = stat->atime;
1173         inode->i_mtime.tv_sec = stat->mtime;
1174         inode->i_ctime.tv_sec = stat->mtime;
1175 
1176         inode->i_uid = v9ses->dfltuid;
1177         inode->i_gid = v9ses->dfltgid;
1178 
1179         if (v9fs_proto_dotu(v9ses)) {
1180                 inode->i_uid = stat->n_uid;
1181                 inode->i_gid = stat->n_gid;
1182         }
1183         if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1184                 if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1185                         /*
1186                          * Hadlink support got added later to
1187                          * to the .u extension. So there can be
1188                          * server out there that doesn't support
1189                          * this even with .u extension. So check
1190                          * for non NULL stat->extension
1191                          */
1192                         strlcpy(ext, stat->extension, sizeof(ext));
1193                         /* HARDLINKCOUNT %u */
1194                         sscanf(ext, "%13s %u", tag_name, &i_nlink);
1195                         if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1196                                 set_nlink(inode, i_nlink);
1197                 }
1198         }
1199         mode = p9mode2perm(v9ses, stat);
1200         mode |= inode->i_mode & ~S_IALLUGO;
1201         inode->i_mode = mode;
1202         i_size_write(inode, stat->length);
1203 
1204         /* not real number of blocks, but 512 byte ones ... */
1205         inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1206         v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1207 }
1208 
1209 /**
1210  * v9fs_qid2ino - convert qid into inode number
1211  * @qid: qid to hash
1212  *
1213  * BUG: potential for inode number collisions?
1214  */
1215 
1216 ino_t v9fs_qid2ino(struct p9_qid *qid)
1217 {
1218         u64 path = qid->path + 2;
1219         ino_t i = 0;
1220 
1221         if (sizeof(ino_t) == sizeof(path))
1222                 memcpy(&i, &path, sizeof(ino_t));
1223         else
1224                 i = (ino_t) (path ^ (path >> 32));
1225 
1226         return i;
1227 }
1228 
1229 /**
1230  * v9fs_vfs_get_link - follow a symlink path
1231  * @dentry: dentry for symlink
1232  * @inode: inode for symlink
1233  * @done: delayed call for when we are done with the return value
1234  */
1235 
1236 static const char *v9fs_vfs_get_link(struct dentry *dentry,
1237                                      struct inode *inode,
1238                                      struct delayed_call *done)
1239 {
1240         struct v9fs_session_info *v9ses;
1241         struct p9_fid *fid;
1242         struct p9_wstat *st;
1243         char *res;
1244 
1245         if (!dentry)
1246                 return ERR_PTR(-ECHILD);
1247 
1248         v9ses = v9fs_dentry2v9ses(dentry);
1249         fid = v9fs_fid_lookup(dentry);
1250         p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1251 
1252         if (IS_ERR(fid))
1253                 return ERR_CAST(fid);
1254 
1255         if (!v9fs_proto_dotu(v9ses))
1256                 return ERR_PTR(-EBADF);
1257 
1258         st = p9_client_stat(fid);
1259         if (IS_ERR(st))
1260                 return ERR_CAST(st);
1261 
1262         if (!(st->mode & P9_DMSYMLINK)) {
1263                 p9stat_free(st);
1264                 kfree(st);
1265                 return ERR_PTR(-EINVAL);
1266         }
1267         res = st->extension;
1268         st->extension = NULL;
1269         if (strlen(res) >= PATH_MAX)
1270                 res[PATH_MAX - 1] = '\0';
1271 
1272         p9stat_free(st);
1273         kfree(st);
1274         set_delayed_call(done, kfree_link, res);
1275         return res;
1276 }
1277 
1278 /**
1279  * v9fs_vfs_mkspecial - create a special file
1280  * @dir: inode to create special file in
1281  * @dentry: dentry to create
1282  * @perm: mode to create special file
1283  * @extension: 9p2000.u format extension string representing special file
1284  *
1285  */
1286 
1287 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1288         u32 perm, const char *extension)
1289 {
1290         struct p9_fid *fid;
1291         struct v9fs_session_info *v9ses;
1292 
1293         v9ses = v9fs_inode2v9ses(dir);
1294         if (!v9fs_proto_dotu(v9ses)) {
1295                 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1296                 return -EPERM;
1297         }
1298 
1299         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1300                                                                 P9_OREAD);
1301         if (IS_ERR(fid))
1302                 return PTR_ERR(fid);
1303 
1304         v9fs_invalidate_inode_attr(dir);
1305         p9_client_clunk(fid);
1306         return 0;
1307 }
1308 
1309 /**
1310  * v9fs_vfs_symlink - helper function to create symlinks
1311  * @dir: directory inode containing symlink
1312  * @dentry: dentry for symlink
1313  * @symname: symlink data
1314  *
1315  * See Also: 9P2000.u RFC for more information
1316  *
1317  */
1318 
1319 static int
1320 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1321 {
1322         p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1323                  dir->i_ino, dentry, symname);
1324 
1325         return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1326 }
1327 
1328 #define U32_MAX_DIGITS 10
1329 
1330 /**
1331  * v9fs_vfs_link - create a hardlink
1332  * @old_dentry: dentry for file to link to
1333  * @dir: inode destination for new link
1334  * @dentry: dentry for link
1335  *
1336  */
1337 
1338 static int
1339 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1340               struct dentry *dentry)
1341 {
1342         int retval;
1343         char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1344         struct p9_fid *oldfid;
1345 
1346         p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1347                  dir->i_ino, dentry, old_dentry);
1348 
1349         oldfid = v9fs_fid_clone(old_dentry);
1350         if (IS_ERR(oldfid))
1351                 return PTR_ERR(oldfid);
1352 
1353         sprintf(name, "%d\n", oldfid->fid);
1354         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1355         if (!retval) {
1356                 v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1357                 v9fs_invalidate_inode_attr(dir);
1358         }
1359         p9_client_clunk(oldfid);
1360         return retval;
1361 }
1362 
1363 /**
1364  * v9fs_vfs_mknod - create a special file
1365  * @dir: inode destination for new link
1366  * @dentry: dentry for file
1367  * @mode: mode for creation
1368  * @rdev: device associated with special file
1369  *
1370  */
1371 
1372 static int
1373 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1374 {
1375         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1376         int retval;
1377         char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1378         u32 perm;
1379 
1380         p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n",
1381                  dir->i_ino, dentry, mode,
1382                  MAJOR(rdev), MINOR(rdev));
1383 
1384         /* build extension */
1385         if (S_ISBLK(mode))
1386                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1387         else if (S_ISCHR(mode))
1388                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1389         else
1390                 *name = 0;
1391 
1392         perm = unixmode2p9mode(v9ses, mode);
1393         retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1394 
1395         return retval;
1396 }
1397 
1398 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1399 {
1400         int umode;
1401         dev_t rdev;
1402         loff_t i_size;
1403         struct p9_wstat *st;
1404         struct v9fs_session_info *v9ses;
1405 
1406         v9ses = v9fs_inode2v9ses(inode);
1407         st = p9_client_stat(fid);
1408         if (IS_ERR(st))
1409                 return PTR_ERR(st);
1410         /*
1411          * Don't update inode if the file type is different
1412          */
1413         umode = p9mode2unixmode(v9ses, st, &rdev);
1414         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1415                 goto out;
1416 
1417         spin_lock(&inode->i_lock);
1418         /*
1419          * We don't want to refresh inode->i_size,
1420          * because we may have cached data
1421          */
1422         i_size = inode->i_size;
1423         v9fs_stat2inode(st, inode, inode->i_sb);
1424         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
1425                 inode->i_size = i_size;
1426         spin_unlock(&inode->i_lock);
1427 out:
1428         p9stat_free(st);
1429         kfree(st);
1430         return 0;
1431 }
1432 
1433 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1434         .create = v9fs_vfs_create,
1435         .lookup = v9fs_vfs_lookup,
1436         .atomic_open = v9fs_vfs_atomic_open,
1437         .symlink = v9fs_vfs_symlink,
1438         .link = v9fs_vfs_link,
1439         .unlink = v9fs_vfs_unlink,
1440         .mkdir = v9fs_vfs_mkdir,
1441         .rmdir = v9fs_vfs_rmdir,
1442         .mknod = v9fs_vfs_mknod,
1443         .rename = v9fs_vfs_rename,
1444         .getattr = v9fs_vfs_getattr,
1445         .setattr = v9fs_vfs_setattr,
1446 };
1447 
1448 static const struct inode_operations v9fs_dir_inode_operations = {
1449         .create = v9fs_vfs_create,
1450         .lookup = v9fs_vfs_lookup,
1451         .atomic_open = v9fs_vfs_atomic_open,
1452         .unlink = v9fs_vfs_unlink,
1453         .mkdir = v9fs_vfs_mkdir,
1454         .rmdir = v9fs_vfs_rmdir,
1455         .mknod = v9fs_vfs_mknod,
1456         .rename = v9fs_vfs_rename,
1457         .getattr = v9fs_vfs_getattr,
1458         .setattr = v9fs_vfs_setattr,
1459 };
1460 
1461 static const struct inode_operations v9fs_file_inode_operations = {
1462         .getattr = v9fs_vfs_getattr,
1463         .setattr = v9fs_vfs_setattr,
1464 };
1465 
1466 static const struct inode_operations v9fs_symlink_inode_operations = {
1467         .get_link = v9fs_vfs_get_link,
1468         .getattr = v9fs_vfs_getattr,
1469         .setattr = v9fs_vfs_setattr,
1470 };
1471 
1472 

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