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Linux/fs/9p/vfs_inode.c

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  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  *  linux/fs/9p/vfs_inode.c
  4  *
  5  * This file contains vfs inode ops for the 9P2000 protocol.
  6  *
  7  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
  8  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
  9  */
 10 
 11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 12 
 13 #include <linux/module.h>
 14 #include <linux/errno.h>
 15 #include <linux/fs.h>
 16 #include <linux/file.h>
 17 #include <linux/pagemap.h>
 18 #include <linux/stat.h>
 19 #include <linux/string.h>
 20 #include <linux/inet.h>
 21 #include <linux/namei.h>
 22 #include <linux/idr.h>
 23 #include <linux/sched.h>
 24 #include <linux/slab.h>
 25 #include <linux/xattr.h>
 26 #include <linux/posix_acl.h>
 27 #include <net/9p/9p.h>
 28 #include <net/9p/client.h>
 29 
 30 #include "v9fs.h"
 31 #include "v9fs_vfs.h"
 32 #include "fid.h"
 33 #include "cache.h"
 34 #include "xattr.h"
 35 #include "acl.h"
 36 
 37 static const struct inode_operations v9fs_dir_inode_operations;
 38 static const struct inode_operations v9fs_dir_inode_operations_dotu;
 39 static const struct inode_operations v9fs_file_inode_operations;
 40 static const struct inode_operations v9fs_symlink_inode_operations;
 41 
 42 /**
 43  * unixmode2p9mode - convert unix mode bits to plan 9
 44  * @v9ses: v9fs session information
 45  * @mode: mode to convert
 46  *
 47  */
 48 
 49 static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
 50 {
 51         int res;
 52         res = mode & 0777;
 53         if (S_ISDIR(mode))
 54                 res |= P9_DMDIR;
 55         if (v9fs_proto_dotu(v9ses)) {
 56                 if (v9ses->nodev == 0) {
 57                         if (S_ISSOCK(mode))
 58                                 res |= P9_DMSOCKET;
 59                         if (S_ISFIFO(mode))
 60                                 res |= P9_DMNAMEDPIPE;
 61                         if (S_ISBLK(mode))
 62                                 res |= P9_DMDEVICE;
 63                         if (S_ISCHR(mode))
 64                                 res |= P9_DMDEVICE;
 65                 }
 66 
 67                 if ((mode & S_ISUID) == S_ISUID)
 68                         res |= P9_DMSETUID;
 69                 if ((mode & S_ISGID) == S_ISGID)
 70                         res |= P9_DMSETGID;
 71                 if ((mode & S_ISVTX) == S_ISVTX)
 72                         res |= P9_DMSETVTX;
 73         }
 74         return res;
 75 }
 76 
 77 /**
 78  * p9mode2perm- convert plan9 mode bits to unix permission bits
 79  * @v9ses: v9fs session information
 80  * @stat: p9_wstat from which mode need to be derived
 81  *
 82  */
 83 static int p9mode2perm(struct v9fs_session_info *v9ses,
 84                        struct p9_wstat *stat)
 85 {
 86         int res;
 87         int mode = stat->mode;
 88 
 89         res = mode & S_IALLUGO;
 90         if (v9fs_proto_dotu(v9ses)) {
 91                 if ((mode & P9_DMSETUID) == P9_DMSETUID)
 92                         res |= S_ISUID;
 93 
 94                 if ((mode & P9_DMSETGID) == P9_DMSETGID)
 95                         res |= S_ISGID;
 96 
 97                 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
 98                         res |= S_ISVTX;
 99         }
100         return res;
101 }
102 
103 /**
104  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
105  * @v9ses: v9fs session information
106  * @stat: p9_wstat from which mode need to be derived
107  * @rdev: major number, minor number in case of device files.
108  *
109  */
110 static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
111                                struct p9_wstat *stat, dev_t *rdev)
112 {
113         int res;
114         u32 mode = stat->mode;
115 
116         *rdev = 0;
117         res = p9mode2perm(v9ses, stat);
118 
119         if ((mode & P9_DMDIR) == P9_DMDIR)
120                 res |= S_IFDIR;
121         else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
122                 res |= S_IFLNK;
123         else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
124                  && (v9ses->nodev == 0))
125                 res |= S_IFSOCK;
126         else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
127                  && (v9ses->nodev == 0))
128                 res |= S_IFIFO;
129         else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
130                  && (v9ses->nodev == 0)) {
131                 char type = 0, ext[32];
132                 int major = -1, minor = -1;
133 
134                 strlcpy(ext, stat->extension, sizeof(ext));
135                 sscanf(ext, "%c %i %i", &type, &major, &minor);
136                 switch (type) {
137                 case 'c':
138                         res |= S_IFCHR;
139                         break;
140                 case 'b':
141                         res |= S_IFBLK;
142                         break;
143                 default:
144                         p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
145                                  type, stat->extension);
146                 };
147                 *rdev = MKDEV(major, minor);
148         } else
149                 res |= S_IFREG;
150 
151         return res;
152 }
153 
154 /**
155  * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
156  * @uflags: flags to convert
157  * @extended: if .u extensions are active
158  */
159 
160 int v9fs_uflags2omode(int uflags, int extended)
161 {
162         int ret;
163 
164         ret = 0;
165         switch (uflags&3) {
166         default:
167         case O_RDONLY:
168                 ret = P9_OREAD;
169                 break;
170 
171         case O_WRONLY:
172                 ret = P9_OWRITE;
173                 break;
174 
175         case O_RDWR:
176                 ret = P9_ORDWR;
177                 break;
178         }
179 
180         if (extended) {
181                 if (uflags & O_EXCL)
182                         ret |= P9_OEXCL;
183 
184                 if (uflags & O_APPEND)
185                         ret |= P9_OAPPEND;
186         }
187 
188         return ret;
189 }
190 
191 /**
192  * v9fs_blank_wstat - helper function to setup a 9P stat structure
193  * @wstat: structure to initialize
194  *
195  */
196 
197 void
198 v9fs_blank_wstat(struct p9_wstat *wstat)
199 {
200         wstat->type = ~0;
201         wstat->dev = ~0;
202         wstat->qid.type = ~0;
203         wstat->qid.version = ~0;
204         *((long long *)&wstat->qid.path) = ~0;
205         wstat->mode = ~0;
206         wstat->atime = ~0;
207         wstat->mtime = ~0;
208         wstat->length = ~0;
209         wstat->name = NULL;
210         wstat->uid = NULL;
211         wstat->gid = NULL;
212         wstat->muid = NULL;
213         wstat->n_uid = INVALID_UID;
214         wstat->n_gid = INVALID_GID;
215         wstat->n_muid = INVALID_UID;
216         wstat->extension = NULL;
217 }
218 
219 /**
220  * v9fs_alloc_inode - helper function to allocate an inode
221  *
222  */
223 struct inode *v9fs_alloc_inode(struct super_block *sb)
224 {
225         struct v9fs_inode *v9inode;
226         v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
227                                                         GFP_KERNEL);
228         if (!v9inode)
229                 return NULL;
230 #ifdef CONFIG_9P_FSCACHE
231         v9inode->fscache = NULL;
232         mutex_init(&v9inode->fscache_lock);
233 #endif
234         v9inode->writeback_fid = NULL;
235         v9inode->cache_validity = 0;
236         mutex_init(&v9inode->v_mutex);
237         return &v9inode->vfs_inode;
238 }
239 
240 /**
241  * v9fs_free_inode - destroy an inode
242  *
243  */
244 
245 void v9fs_free_inode(struct inode *inode)
246 {
247         kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
248 }
249 
250 int v9fs_init_inode(struct v9fs_session_info *v9ses,
251                     struct inode *inode, umode_t mode, dev_t rdev)
252 {
253         int err = 0;
254 
255         inode_init_owner(inode, NULL, mode);
256         inode->i_blocks = 0;
257         inode->i_rdev = rdev;
258         inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
259         inode->i_mapping->a_ops = &v9fs_addr_operations;
260 
261         switch (mode & S_IFMT) {
262         case S_IFIFO:
263         case S_IFBLK:
264         case S_IFCHR:
265         case S_IFSOCK:
266                 if (v9fs_proto_dotl(v9ses)) {
267                         inode->i_op = &v9fs_file_inode_operations_dotl;
268                 } else if (v9fs_proto_dotu(v9ses)) {
269                         inode->i_op = &v9fs_file_inode_operations;
270                 } else {
271                         p9_debug(P9_DEBUG_ERROR,
272                                  "special files without extended mode\n");
273                         err = -EINVAL;
274                         goto error;
275                 }
276                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
277                 break;
278         case S_IFREG:
279                 if (v9fs_proto_dotl(v9ses)) {
280                         inode->i_op = &v9fs_file_inode_operations_dotl;
281                         if (v9ses->cache == CACHE_LOOSE ||
282                             v9ses->cache == CACHE_FSCACHE)
283                                 inode->i_fop =
284                                         &v9fs_cached_file_operations_dotl;
285                         else if (v9ses->cache == CACHE_MMAP)
286                                 inode->i_fop = &v9fs_mmap_file_operations_dotl;
287                         else
288                                 inode->i_fop = &v9fs_file_operations_dotl;
289                 } else {
290                         inode->i_op = &v9fs_file_inode_operations;
291                         if (v9ses->cache == CACHE_LOOSE ||
292                             v9ses->cache == CACHE_FSCACHE)
293                                 inode->i_fop =
294                                         &v9fs_cached_file_operations;
295                         else if (v9ses->cache == CACHE_MMAP)
296                                 inode->i_fop = &v9fs_mmap_file_operations;
297                         else
298                                 inode->i_fop = &v9fs_file_operations;
299                 }
300 
301                 break;
302         case S_IFLNK:
303                 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
304                         p9_debug(P9_DEBUG_ERROR,
305                                  "extended modes used with legacy protocol\n");
306                         err = -EINVAL;
307                         goto error;
308                 }
309 
310                 if (v9fs_proto_dotl(v9ses))
311                         inode->i_op = &v9fs_symlink_inode_operations_dotl;
312                 else
313                         inode->i_op = &v9fs_symlink_inode_operations;
314 
315                 break;
316         case S_IFDIR:
317                 inc_nlink(inode);
318                 if (v9fs_proto_dotl(v9ses))
319                         inode->i_op = &v9fs_dir_inode_operations_dotl;
320                 else if (v9fs_proto_dotu(v9ses))
321                         inode->i_op = &v9fs_dir_inode_operations_dotu;
322                 else
323                         inode->i_op = &v9fs_dir_inode_operations;
324 
325                 if (v9fs_proto_dotl(v9ses))
326                         inode->i_fop = &v9fs_dir_operations_dotl;
327                 else
328                         inode->i_fop = &v9fs_dir_operations;
329 
330                 break;
331         default:
332                 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
333                          mode, mode & S_IFMT);
334                 err = -EINVAL;
335                 goto error;
336         }
337 error:
338         return err;
339 
340 }
341 
342 /**
343  * v9fs_get_inode - helper function to setup an inode
344  * @sb: superblock
345  * @mode: mode to setup inode with
346  *
347  */
348 
349 struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
350 {
351         int err;
352         struct inode *inode;
353         struct v9fs_session_info *v9ses = sb->s_fs_info;
354 
355         p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
356 
357         inode = new_inode(sb);
358         if (!inode) {
359                 pr_warn("%s (%d): Problem allocating inode\n",
360                         __func__, task_pid_nr(current));
361                 return ERR_PTR(-ENOMEM);
362         }
363         err = v9fs_init_inode(v9ses, inode, mode, rdev);
364         if (err) {
365                 iput(inode);
366                 return ERR_PTR(err);
367         }
368         return inode;
369 }
370 
371 /*
372 static struct v9fs_fid*
373 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
374 {
375         int err;
376         int nfid;
377         struct v9fs_fid *ret;
378         struct v9fs_fcall *fcall;
379 
380         nfid = v9fs_get_idpool(&v9ses->fidpool);
381         if (nfid < 0) {
382                 eprintk(KERN_WARNING, "no free fids available\n");
383                 return ERR_PTR(-ENOSPC);
384         }
385 
386         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
387                 &fcall);
388 
389         if (err < 0) {
390                 if (fcall && fcall->id == RWALK)
391                         goto clunk_fid;
392 
393                 PRINT_FCALL_ERROR("walk error", fcall);
394                 v9fs_put_idpool(nfid, &v9ses->fidpool);
395                 goto error;
396         }
397 
398         kfree(fcall);
399         fcall = NULL;
400         ret = v9fs_fid_create(v9ses, nfid);
401         if (!ret) {
402                 err = -ENOMEM;
403                 goto clunk_fid;
404         }
405 
406         err = v9fs_fid_insert(ret, dentry);
407         if (err < 0) {
408                 v9fs_fid_destroy(ret);
409                 goto clunk_fid;
410         }
411 
412         return ret;
413 
414 clunk_fid:
415         v9fs_t_clunk(v9ses, nfid);
416 
417 error:
418         kfree(fcall);
419         return ERR_PTR(err);
420 }
421 */
422 
423 
424 /**
425  * v9fs_clear_inode - release an inode
426  * @inode: inode to release
427  *
428  */
429 void v9fs_evict_inode(struct inode *inode)
430 {
431         struct v9fs_inode *v9inode = V9FS_I(inode);
432 
433         truncate_inode_pages_final(&inode->i_data);
434         clear_inode(inode);
435         filemap_fdatawrite(&inode->i_data);
436 
437         v9fs_cache_inode_put_cookie(inode);
438         /* clunk the fid stashed in writeback_fid */
439         if (v9inode->writeback_fid) {
440                 p9_client_clunk(v9inode->writeback_fid);
441                 v9inode->writeback_fid = NULL;
442         }
443 }
444 
445 static int v9fs_test_inode(struct inode *inode, void *data)
446 {
447         int umode;
448         dev_t rdev;
449         struct v9fs_inode *v9inode = V9FS_I(inode);
450         struct p9_wstat *st = (struct p9_wstat *)data;
451         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
452 
453         umode = p9mode2unixmode(v9ses, st, &rdev);
454         /* don't match inode of different type */
455         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
456                 return 0;
457 
458         /* compare qid details */
459         if (memcmp(&v9inode->qid.version,
460                    &st->qid.version, sizeof(v9inode->qid.version)))
461                 return 0;
462 
463         if (v9inode->qid.type != st->qid.type)
464                 return 0;
465 
466         if (v9inode->qid.path != st->qid.path)
467                 return 0;
468         return 1;
469 }
470 
471 static int v9fs_test_new_inode(struct inode *inode, void *data)
472 {
473         return 0;
474 }
475 
476 static int v9fs_set_inode(struct inode *inode,  void *data)
477 {
478         struct v9fs_inode *v9inode = V9FS_I(inode);
479         struct p9_wstat *st = (struct p9_wstat *)data;
480 
481         memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
482         return 0;
483 }
484 
485 static struct inode *v9fs_qid_iget(struct super_block *sb,
486                                    struct p9_qid *qid,
487                                    struct p9_wstat *st,
488                                    int new)
489 {
490         dev_t rdev;
491         int retval;
492         umode_t umode;
493         unsigned long i_ino;
494         struct inode *inode;
495         struct v9fs_session_info *v9ses = sb->s_fs_info;
496         int (*test)(struct inode *, void *);
497 
498         if (new)
499                 test = v9fs_test_new_inode;
500         else
501                 test = v9fs_test_inode;
502 
503         i_ino = v9fs_qid2ino(qid);
504         inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
505         if (!inode)
506                 return ERR_PTR(-ENOMEM);
507         if (!(inode->i_state & I_NEW))
508                 return inode;
509         /*
510          * initialize the inode with the stat info
511          * FIXME!! we may need support for stale inodes
512          * later.
513          */
514         inode->i_ino = i_ino;
515         umode = p9mode2unixmode(v9ses, st, &rdev);
516         retval = v9fs_init_inode(v9ses, inode, umode, rdev);
517         if (retval)
518                 goto error;
519 
520         v9fs_stat2inode(st, inode, sb, 0);
521         v9fs_cache_inode_get_cookie(inode);
522         unlock_new_inode(inode);
523         return inode;
524 error:
525         iget_failed(inode);
526         return ERR_PTR(retval);
527 
528 }
529 
530 struct inode *
531 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
532                     struct super_block *sb, int new)
533 {
534         struct p9_wstat *st;
535         struct inode *inode = NULL;
536 
537         st = p9_client_stat(fid);
538         if (IS_ERR(st))
539                 return ERR_CAST(st);
540 
541         inode = v9fs_qid_iget(sb, &st->qid, st, new);
542         p9stat_free(st);
543         kfree(st);
544         return inode;
545 }
546 
547 /**
548  * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
549  * plan 9 AT flag.
550  * @flags: flags to convert
551  */
552 static int v9fs_at_to_dotl_flags(int flags)
553 {
554         int rflags = 0;
555         if (flags & AT_REMOVEDIR)
556                 rflags |= P9_DOTL_AT_REMOVEDIR;
557         return rflags;
558 }
559 
560 /**
561  * v9fs_dec_count - helper functon to drop i_nlink.
562  *
563  * If a directory had nlink <= 2 (including . and ..), then we should not drop
564  * the link count, which indicates the underlying exported fs doesn't maintain
565  * nlink accurately. e.g.
566  * - overlayfs sets nlink to 1 for merged dir
567  * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
568  *   than EXT4_LINK_MAX (65000) links.
569  *
570  * @inode: inode whose nlink is being dropped
571  */
572 static void v9fs_dec_count(struct inode *inode)
573 {
574         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
575                 drop_nlink(inode);
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                         v9fs_dec_count(dir);
622                 } else
623                         v9fs_dec_count(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         const unsigned 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 = 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         const unsigned 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         /*
806          * Make sure we don't use a wrong inode due to parallel
807          * unlink. For cached mode create calls request for new
808          * inode. But with cache disabled, lookup should do this.
809          */
810         name = dentry->d_name.name;
811         fid = p9_client_walk(dfid, 1, &name, 1);
812         if (fid == ERR_PTR(-ENOENT))
813                 inode = NULL;
814         else if (IS_ERR(fid))
815                 inode = ERR_CAST(fid);
816         else if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
817                 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
818         else
819                 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
820         /*
821          * If we had a rename on the server and a parallel lookup
822          * for the new name, then make sure we instantiate with
823          * the new name. ie look up for a/b, while on server somebody
824          * moved b under k and client parallely did a lookup for
825          * k/b.
826          */
827         res = d_splice_alias(inode, dentry);
828         if (!IS_ERR(fid)) {
829                 if (!res)
830                         v9fs_fid_add(dentry, fid);
831                 else if (!IS_ERR(res))
832                         v9fs_fid_add(res, fid);
833                 else
834                         p9_client_clunk(fid);
835         }
836         return res;
837 }
838 
839 static int
840 v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
841                      struct file *file, unsigned flags, umode_t mode)
842 {
843         int err;
844         u32 perm;
845         struct v9fs_inode *v9inode;
846         struct v9fs_session_info *v9ses;
847         struct p9_fid *fid, *inode_fid;
848         struct dentry *res = NULL;
849 
850         if (d_in_lookup(dentry)) {
851                 res = v9fs_vfs_lookup(dir, dentry, 0);
852                 if (IS_ERR(res))
853                         return PTR_ERR(res);
854 
855                 if (res)
856                         dentry = res;
857         }
858 
859         /* Only creates */
860         if (!(flags & O_CREAT) || d_really_is_positive(dentry))
861                 return finish_no_open(file, res);
862 
863         err = 0;
864 
865         v9ses = v9fs_inode2v9ses(dir);
866         perm = unixmode2p9mode(v9ses, mode);
867         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
868                                 v9fs_uflags2omode(flags,
869                                                 v9fs_proto_dotu(v9ses)));
870         if (IS_ERR(fid)) {
871                 err = PTR_ERR(fid);
872                 fid = NULL;
873                 goto error;
874         }
875 
876         v9fs_invalidate_inode_attr(dir);
877         v9inode = V9FS_I(d_inode(dentry));
878         mutex_lock(&v9inode->v_mutex);
879         if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
880             !v9inode->writeback_fid &&
881             ((flags & O_ACCMODE) != O_RDONLY)) {
882                 /*
883                  * clone a fid and add it to writeback_fid
884                  * we do it during open time instead of
885                  * page dirty time via write_begin/page_mkwrite
886                  * because we want write after unlink usecase
887                  * to work.
888                  */
889                 inode_fid = v9fs_writeback_fid(dentry);
890                 if (IS_ERR(inode_fid)) {
891                         err = PTR_ERR(inode_fid);
892                         mutex_unlock(&v9inode->v_mutex);
893                         goto error;
894                 }
895                 v9inode->writeback_fid = (void *) inode_fid;
896         }
897         mutex_unlock(&v9inode->v_mutex);
898         err = finish_open(file, dentry, generic_file_open);
899         if (err)
900                 goto error;
901 
902         file->private_data = fid;
903         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
904                 v9fs_cache_inode_set_cookie(d_inode(dentry), file);
905 
906         file->f_mode |= FMODE_CREATED;
907 out:
908         dput(res);
909         return err;
910 
911 error:
912         if (fid)
913                 p9_client_clunk(fid);
914         goto out;
915 }
916 
917 /**
918  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
919  * @i:  inode that is being unlinked
920  * @d: dentry that is being unlinked
921  *
922  */
923 
924 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
925 {
926         return v9fs_remove(i, d, 0);
927 }
928 
929 /**
930  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
931  * @i:  inode that is being unlinked
932  * @d: dentry that is being unlinked
933  *
934  */
935 
936 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
937 {
938         return v9fs_remove(i, d, AT_REMOVEDIR);
939 }
940 
941 /**
942  * v9fs_vfs_rename - VFS hook to rename an inode
943  * @old_dir:  old dir inode
944  * @old_dentry: old dentry
945  * @new_dir: new dir inode
946  * @new_dentry: new dentry
947  *
948  */
949 
950 int
951 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
952                 struct inode *new_dir, struct dentry *new_dentry,
953                 unsigned int flags)
954 {
955         int retval;
956         struct inode *old_inode;
957         struct inode *new_inode;
958         struct v9fs_session_info *v9ses;
959         struct p9_fid *oldfid;
960         struct p9_fid *olddirfid;
961         struct p9_fid *newdirfid;
962         struct p9_wstat wstat;
963 
964         if (flags)
965                 return -EINVAL;
966 
967         p9_debug(P9_DEBUG_VFS, "\n");
968         retval = 0;
969         old_inode = d_inode(old_dentry);
970         new_inode = d_inode(new_dentry);
971         v9ses = v9fs_inode2v9ses(old_inode);
972         oldfid = v9fs_fid_lookup(old_dentry);
973         if (IS_ERR(oldfid))
974                 return PTR_ERR(oldfid);
975 
976         olddirfid = clone_fid(v9fs_parent_fid(old_dentry));
977         if (IS_ERR(olddirfid)) {
978                 retval = PTR_ERR(olddirfid);
979                 goto done;
980         }
981 
982         newdirfid = clone_fid(v9fs_parent_fid(new_dentry));
983         if (IS_ERR(newdirfid)) {
984                 retval = PTR_ERR(newdirfid);
985                 goto clunk_olddir;
986         }
987 
988         down_write(&v9ses->rename_sem);
989         if (v9fs_proto_dotl(v9ses)) {
990                 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
991                                             newdirfid, new_dentry->d_name.name);
992                 if (retval == -EOPNOTSUPP)
993                         retval = p9_client_rename(oldfid, newdirfid,
994                                                   new_dentry->d_name.name);
995                 if (retval != -EOPNOTSUPP)
996                         goto clunk_newdir;
997         }
998         if (old_dentry->d_parent != new_dentry->d_parent) {
999                 /*
1000                  * 9P .u can only handle file rename in the same directory
1001                  */
1002 
1003                 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
1004                 retval = -EXDEV;
1005                 goto clunk_newdir;
1006         }
1007         v9fs_blank_wstat(&wstat);
1008         wstat.muid = v9ses->uname;
1009         wstat.name = new_dentry->d_name.name;
1010         retval = p9_client_wstat(oldfid, &wstat);
1011 
1012 clunk_newdir:
1013         if (!retval) {
1014                 if (new_inode) {
1015                         if (S_ISDIR(new_inode->i_mode))
1016                                 clear_nlink(new_inode);
1017                         else
1018                                 v9fs_dec_count(new_inode);
1019                 }
1020                 if (S_ISDIR(old_inode->i_mode)) {
1021                         if (!new_inode)
1022                                 inc_nlink(new_dir);
1023                         v9fs_dec_count(old_dir);
1024                 }
1025                 v9fs_invalidate_inode_attr(old_inode);
1026                 v9fs_invalidate_inode_attr(old_dir);
1027                 v9fs_invalidate_inode_attr(new_dir);
1028 
1029                 /* successful rename */
1030                 d_move(old_dentry, new_dentry);
1031         }
1032         up_write(&v9ses->rename_sem);
1033         p9_client_clunk(newdirfid);
1034 
1035 clunk_olddir:
1036         p9_client_clunk(olddirfid);
1037 
1038 done:
1039         return retval;
1040 }
1041 
1042 /**
1043  * v9fs_vfs_getattr - retrieve file metadata
1044  * @path: Object to query
1045  * @stat: metadata structure to populate
1046  * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
1047  * @flags: AT_STATX_xxx setting
1048  *
1049  */
1050 
1051 static int
1052 v9fs_vfs_getattr(const struct path *path, struct kstat *stat,
1053                  u32 request_mask, unsigned int flags)
1054 {
1055         struct dentry *dentry = path->dentry;
1056         struct v9fs_session_info *v9ses;
1057         struct p9_fid *fid;
1058         struct p9_wstat *st;
1059 
1060         p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1061         v9ses = v9fs_dentry2v9ses(dentry);
1062         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1063                 generic_fillattr(d_inode(dentry), stat);
1064                 return 0;
1065         }
1066         fid = v9fs_fid_lookup(dentry);
1067         if (IS_ERR(fid))
1068                 return PTR_ERR(fid);
1069 
1070         st = p9_client_stat(fid);
1071         if (IS_ERR(st))
1072                 return PTR_ERR(st);
1073 
1074         v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0);
1075         generic_fillattr(d_inode(dentry), stat);
1076 
1077         p9stat_free(st);
1078         kfree(st);
1079         return 0;
1080 }
1081 
1082 /**
1083  * v9fs_vfs_setattr - set file metadata
1084  * @dentry: file whose metadata to set
1085  * @iattr: metadata assignment structure
1086  *
1087  */
1088 
1089 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1090 {
1091         int retval;
1092         struct v9fs_session_info *v9ses;
1093         struct p9_fid *fid;
1094         struct p9_wstat wstat;
1095 
1096         p9_debug(P9_DEBUG_VFS, "\n");
1097         retval = setattr_prepare(dentry, iattr);
1098         if (retval)
1099                 return retval;
1100 
1101         retval = -EPERM;
1102         v9ses = v9fs_dentry2v9ses(dentry);
1103         fid = v9fs_fid_lookup(dentry);
1104         if(IS_ERR(fid))
1105                 return PTR_ERR(fid);
1106 
1107         v9fs_blank_wstat(&wstat);
1108         if (iattr->ia_valid & ATTR_MODE)
1109                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1110 
1111         if (iattr->ia_valid & ATTR_MTIME)
1112                 wstat.mtime = iattr->ia_mtime.tv_sec;
1113 
1114         if (iattr->ia_valid & ATTR_ATIME)
1115                 wstat.atime = iattr->ia_atime.tv_sec;
1116 
1117         if (iattr->ia_valid & ATTR_SIZE)
1118                 wstat.length = iattr->ia_size;
1119 
1120         if (v9fs_proto_dotu(v9ses)) {
1121                 if (iattr->ia_valid & ATTR_UID)
1122                         wstat.n_uid = iattr->ia_uid;
1123 
1124                 if (iattr->ia_valid & ATTR_GID)
1125                         wstat.n_gid = iattr->ia_gid;
1126         }
1127 
1128         /* Write all dirty data */
1129         if (d_is_reg(dentry))
1130                 filemap_write_and_wait(d_inode(dentry)->i_mapping);
1131 
1132         retval = p9_client_wstat(fid, &wstat);
1133         if (retval < 0)
1134                 return retval;
1135 
1136         if ((iattr->ia_valid & ATTR_SIZE) &&
1137             iattr->ia_size != i_size_read(d_inode(dentry)))
1138                 truncate_setsize(d_inode(dentry), iattr->ia_size);
1139 
1140         v9fs_invalidate_inode_attr(d_inode(dentry));
1141 
1142         setattr_copy(d_inode(dentry), iattr);
1143         mark_inode_dirty(d_inode(dentry));
1144         return 0;
1145 }
1146 
1147 /**
1148  * v9fs_stat2inode - populate an inode structure with mistat info
1149  * @stat: Plan 9 metadata (mistat) structure
1150  * @inode: inode to populate
1151  * @sb: superblock of filesystem
1152  * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
1153  *
1154  */
1155 
1156 void
1157 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1158                  struct super_block *sb, unsigned int flags)
1159 {
1160         umode_t mode;
1161         char ext[32];
1162         char tag_name[14];
1163         unsigned int i_nlink;
1164         struct v9fs_session_info *v9ses = sb->s_fs_info;
1165         struct v9fs_inode *v9inode = V9FS_I(inode);
1166 
1167         set_nlink(inode, 1);
1168 
1169         inode->i_atime.tv_sec = stat->atime;
1170         inode->i_mtime.tv_sec = stat->mtime;
1171         inode->i_ctime.tv_sec = stat->mtime;
1172 
1173         inode->i_uid = v9ses->dfltuid;
1174         inode->i_gid = v9ses->dfltgid;
1175 
1176         if (v9fs_proto_dotu(v9ses)) {
1177                 inode->i_uid = stat->n_uid;
1178                 inode->i_gid = stat->n_gid;
1179         }
1180         if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1181                 if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1182                         /*
1183                          * Hadlink support got added later to
1184                          * to the .u extension. So there can be
1185                          * server out there that doesn't support
1186                          * this even with .u extension. So check
1187                          * for non NULL stat->extension
1188                          */
1189                         strlcpy(ext, stat->extension, sizeof(ext));
1190                         /* HARDLINKCOUNT %u */
1191                         sscanf(ext, "%13s %u", tag_name, &i_nlink);
1192                         if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1193                                 set_nlink(inode, i_nlink);
1194                 }
1195         }
1196         mode = p9mode2perm(v9ses, stat);
1197         mode |= inode->i_mode & ~S_IALLUGO;
1198         inode->i_mode = mode;
1199 
1200         if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1201                 v9fs_i_size_write(inode, stat->length);
1202         /* not real number of blocks, but 512 byte ones ... */
1203         inode->i_blocks = (stat->length + 512 - 1) >> 9;
1204         v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1205 }
1206 
1207 /**
1208  * v9fs_qid2ino - convert qid into inode number
1209  * @qid: qid to hash
1210  *
1211  * BUG: potential for inode number collisions?
1212  */
1213 
1214 ino_t v9fs_qid2ino(struct p9_qid *qid)
1215 {
1216         u64 path = qid->path + 2;
1217         ino_t i = 0;
1218 
1219         if (sizeof(ino_t) == sizeof(path))
1220                 memcpy(&i, &path, sizeof(ino_t));
1221         else
1222                 i = (ino_t) (path ^ (path >> 32));
1223 
1224         return i;
1225 }
1226 
1227 /**
1228  * v9fs_vfs_get_link - follow a symlink path
1229  * @dentry: dentry for symlink
1230  * @inode: inode for symlink
1231  * @done: delayed call for when we are done with the return value
1232  */
1233 
1234 static const char *v9fs_vfs_get_link(struct dentry *dentry,
1235                                      struct inode *inode,
1236                                      struct delayed_call *done)
1237 {
1238         struct v9fs_session_info *v9ses;
1239         struct p9_fid *fid;
1240         struct p9_wstat *st;
1241         char *res;
1242 
1243         if (!dentry)
1244                 return ERR_PTR(-ECHILD);
1245 
1246         v9ses = v9fs_dentry2v9ses(dentry);
1247         fid = v9fs_fid_lookup(dentry);
1248         p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1249 
1250         if (IS_ERR(fid))
1251                 return ERR_CAST(fid);
1252 
1253         if (!v9fs_proto_dotu(v9ses))
1254                 return ERR_PTR(-EBADF);
1255 
1256         st = p9_client_stat(fid);
1257         if (IS_ERR(st))
1258                 return ERR_CAST(st);
1259 
1260         if (!(st->mode & P9_DMSYMLINK)) {
1261                 p9stat_free(st);
1262                 kfree(st);
1263                 return ERR_PTR(-EINVAL);
1264         }
1265         res = st->extension;
1266         st->extension = NULL;
1267         if (strlen(res) >= PATH_MAX)
1268                 res[PATH_MAX - 1] = '\0';
1269 
1270         p9stat_free(st);
1271         kfree(st);
1272         set_delayed_call(done, kfree_link, res);
1273         return res;
1274 }
1275 
1276 /**
1277  * v9fs_vfs_mkspecial - create a special file
1278  * @dir: inode to create special file in
1279  * @dentry: dentry to create
1280  * @perm: mode to create special file
1281  * @extension: 9p2000.u format extension string representing special file
1282  *
1283  */
1284 
1285 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1286         u32 perm, const char *extension)
1287 {
1288         struct p9_fid *fid;
1289         struct v9fs_session_info *v9ses;
1290 
1291         v9ses = v9fs_inode2v9ses(dir);
1292         if (!v9fs_proto_dotu(v9ses)) {
1293                 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1294                 return -EPERM;
1295         }
1296 
1297         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1298                                                                 P9_OREAD);
1299         if (IS_ERR(fid))
1300                 return PTR_ERR(fid);
1301 
1302         v9fs_invalidate_inode_attr(dir);
1303         p9_client_clunk(fid);
1304         return 0;
1305 }
1306 
1307 /**
1308  * v9fs_vfs_symlink - helper function to create symlinks
1309  * @dir: directory inode containing symlink
1310  * @dentry: dentry for symlink
1311  * @symname: symlink data
1312  *
1313  * See Also: 9P2000.u RFC for more information
1314  *
1315  */
1316 
1317 static int
1318 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1319 {
1320         p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1321                  dir->i_ino, dentry, symname);
1322 
1323         return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1324 }
1325 
1326 #define U32_MAX_DIGITS 10
1327 
1328 /**
1329  * v9fs_vfs_link - create a hardlink
1330  * @old_dentry: dentry for file to link to
1331  * @dir: inode destination for new link
1332  * @dentry: dentry for link
1333  *
1334  */
1335 
1336 static int
1337 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1338               struct dentry *dentry)
1339 {
1340         int retval;
1341         char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1342         struct p9_fid *oldfid;
1343 
1344         p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1345                  dir->i_ino, dentry, old_dentry);
1346 
1347         oldfid = v9fs_fid_clone(old_dentry);
1348         if (IS_ERR(oldfid))
1349                 return PTR_ERR(oldfid);
1350 
1351         sprintf(name, "%d\n", oldfid->fid);
1352         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1353         if (!retval) {
1354                 v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1355                 v9fs_invalidate_inode_attr(dir);
1356         }
1357         p9_client_clunk(oldfid);
1358         return retval;
1359 }
1360 
1361 /**
1362  * v9fs_vfs_mknod - create a special file
1363  * @dir: inode destination for new link
1364  * @dentry: dentry for file
1365  * @mode: mode for creation
1366  * @rdev: device associated with special file
1367  *
1368  */
1369 
1370 static int
1371 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1372 {
1373         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1374         int retval;
1375         char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1376         u32 perm;
1377 
1378         p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n",
1379                  dir->i_ino, dentry, mode,
1380                  MAJOR(rdev), MINOR(rdev));
1381 
1382         /* build extension */
1383         if (S_ISBLK(mode))
1384                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1385         else if (S_ISCHR(mode))
1386                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1387         else
1388                 *name = 0;
1389 
1390         perm = unixmode2p9mode(v9ses, mode);
1391         retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1392 
1393         return retval;
1394 }
1395 
1396 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1397 {
1398         int umode;
1399         dev_t rdev;
1400         struct p9_wstat *st;
1401         struct v9fs_session_info *v9ses;
1402         unsigned int flags;
1403 
1404         v9ses = v9fs_inode2v9ses(inode);
1405         st = p9_client_stat(fid);
1406         if (IS_ERR(st))
1407                 return PTR_ERR(st);
1408         /*
1409          * Don't update inode if the file type is different
1410          */
1411         umode = p9mode2unixmode(v9ses, st, &rdev);
1412         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1413                 goto out;
1414 
1415         /*
1416          * We don't want to refresh inode->i_size,
1417          * because we may have cached data
1418          */
1419         flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
1420                 V9FS_STAT2INODE_KEEP_ISIZE : 0;
1421         v9fs_stat2inode(st, inode, inode->i_sb, flags);
1422 out:
1423         p9stat_free(st);
1424         kfree(st);
1425         return 0;
1426 }
1427 
1428 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1429         .create = v9fs_vfs_create,
1430         .lookup = v9fs_vfs_lookup,
1431         .atomic_open = v9fs_vfs_atomic_open,
1432         .symlink = v9fs_vfs_symlink,
1433         .link = v9fs_vfs_link,
1434         .unlink = v9fs_vfs_unlink,
1435         .mkdir = v9fs_vfs_mkdir,
1436         .rmdir = v9fs_vfs_rmdir,
1437         .mknod = v9fs_vfs_mknod,
1438         .rename = v9fs_vfs_rename,
1439         .getattr = v9fs_vfs_getattr,
1440         .setattr = v9fs_vfs_setattr,
1441 };
1442 
1443 static const struct inode_operations v9fs_dir_inode_operations = {
1444         .create = v9fs_vfs_create,
1445         .lookup = v9fs_vfs_lookup,
1446         .atomic_open = v9fs_vfs_atomic_open,
1447         .unlink = v9fs_vfs_unlink,
1448         .mkdir = v9fs_vfs_mkdir,
1449         .rmdir = v9fs_vfs_rmdir,
1450         .mknod = v9fs_vfs_mknod,
1451         .rename = v9fs_vfs_rename,
1452         .getattr = v9fs_vfs_getattr,
1453         .setattr = v9fs_vfs_setattr,
1454 };
1455 
1456 static const struct inode_operations v9fs_file_inode_operations = {
1457         .getattr = v9fs_vfs_getattr,
1458         .setattr = v9fs_vfs_setattr,
1459 };
1460 
1461 static const struct inode_operations v9fs_symlink_inode_operations = {
1462         .get_link = v9fs_vfs_get_link,
1463         .getattr = v9fs_vfs_getattr,
1464         .setattr = v9fs_vfs_setattr,
1465 };
1466 
1467 

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