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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /* dir.c: AFS filesystem directory handling
  2  *
  3  * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
  4  * Written by David Howells (dhowells@redhat.com)
  5  *
  6  * This program is free software; you can redistribute it and/or
  7  * modify it under the terms of the GNU General Public License
  8  * as published by the Free Software Foundation; either version
  9  * 2 of the License, or (at your option) any later version.
 10  */
 11 
 12 #include <linux/kernel.h>
 13 #include <linux/module.h>
 14 #include <linux/init.h>
 15 #include <linux/slab.h>
 16 #include <linux/fs.h>
 17 #include <linux/pagemap.h>
 18 #include <linux/ctype.h>
 19 #include <linux/sched.h>
 20 #include "internal.h"
 21 
 22 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 23                                  struct nameidata *nd);
 24 static int afs_dir_open(struct inode *inode, struct file *file);
 25 static int afs_readdir(struct file *file, void *dirent, filldir_t filldir);
 26 static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd);
 27 static int afs_d_delete(struct dentry *dentry);
 28 static void afs_d_release(struct dentry *dentry);
 29 static int afs_lookup_filldir(void *_cookie, const char *name, int nlen,
 30                                   loff_t fpos, u64 ino, unsigned dtype);
 31 static int afs_create(struct inode *dir, struct dentry *dentry, int mode,
 32                       struct nameidata *nd);
 33 static int afs_mkdir(struct inode *dir, struct dentry *dentry, int mode);
 34 static int afs_rmdir(struct inode *dir, struct dentry *dentry);
 35 static int afs_unlink(struct inode *dir, struct dentry *dentry);
 36 static int afs_link(struct dentry *from, struct inode *dir,
 37                     struct dentry *dentry);
 38 static int afs_symlink(struct inode *dir, struct dentry *dentry,
 39                        const char *content);
 40 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
 41                       struct inode *new_dir, struct dentry *new_dentry);
 42 
 43 const struct file_operations afs_dir_file_operations = {
 44         .open           = afs_dir_open,
 45         .release        = afs_release,
 46         .readdir        = afs_readdir,
 47         .lock           = afs_lock,
 48 };
 49 
 50 const struct inode_operations afs_dir_inode_operations = {
 51         .create         = afs_create,
 52         .lookup         = afs_lookup,
 53         .link           = afs_link,
 54         .unlink         = afs_unlink,
 55         .symlink        = afs_symlink,
 56         .mkdir          = afs_mkdir,
 57         .rmdir          = afs_rmdir,
 58         .rename         = afs_rename,
 59         .permission     = afs_permission,
 60         .getattr        = afs_getattr,
 61         .setattr        = afs_setattr,
 62 };
 63 
 64 static struct dentry_operations afs_fs_dentry_operations = {
 65         .d_revalidate   = afs_d_revalidate,
 66         .d_delete       = afs_d_delete,
 67         .d_release      = afs_d_release,
 68 };
 69 
 70 #define AFS_DIR_HASHTBL_SIZE    128
 71 #define AFS_DIR_DIRENT_SIZE     32
 72 #define AFS_DIRENT_PER_BLOCK    64
 73 
 74 union afs_dirent {
 75         struct {
 76                 uint8_t         valid;
 77                 uint8_t         unused[1];
 78                 __be16          hash_next;
 79                 __be32          vnode;
 80                 __be32          unique;
 81                 uint8_t         name[16];
 82                 uint8_t         overflow[4];    /* if any char of the name (inc
 83                                                  * NUL) reaches here, consume
 84                                                  * the next dirent too */
 85         } u;
 86         uint8_t extended_name[32];
 87 };
 88 
 89 /* AFS directory page header (one at the beginning of every 2048-byte chunk) */
 90 struct afs_dir_pagehdr {
 91         __be16          npages;
 92         __be16          magic;
 93 #define AFS_DIR_MAGIC htons(1234)
 94         uint8_t         nentries;
 95         uint8_t         bitmap[8];
 96         uint8_t         pad[19];
 97 };
 98 
 99 /* directory block layout */
100 union afs_dir_block {
101 
102         struct afs_dir_pagehdr pagehdr;
103 
104         struct {
105                 struct afs_dir_pagehdr  pagehdr;
106                 uint8_t                 alloc_ctrs[128];
107                 /* dir hash table */
108                 uint16_t                hashtable[AFS_DIR_HASHTBL_SIZE];
109         } hdr;
110 
111         union afs_dirent dirents[AFS_DIRENT_PER_BLOCK];
112 };
113 
114 /* layout on a linux VM page */
115 struct afs_dir_page {
116         union afs_dir_block blocks[PAGE_SIZE / sizeof(union afs_dir_block)];
117 };
118 
119 struct afs_lookup_cookie {
120         struct afs_fid  fid;
121         const char      *name;
122         size_t          nlen;
123         int             found;
124 };
125 
126 /*
127  * check that a directory page is valid
128  */
129 static inline void afs_dir_check_page(struct inode *dir, struct page *page)
130 {
131         struct afs_dir_page *dbuf;
132         loff_t latter;
133         int tmp, qty;
134 
135 #if 0
136         /* check the page count */
137         qty = desc.size / sizeof(dbuf->blocks[0]);
138         if (qty == 0)
139                 goto error;
140 
141         if (page->index == 0 && qty != ntohs(dbuf->blocks[0].pagehdr.npages)) {
142                 printk("kAFS: %s(%lu): wrong number of dir blocks %d!=%hu\n",
143                        __FUNCTION__, dir->i_ino, qty,
144                        ntohs(dbuf->blocks[0].pagehdr.npages));
145                 goto error;
146         }
147 #endif
148 
149         /* determine how many magic numbers there should be in this page */
150         latter = dir->i_size - page_offset(page);
151         if (latter >= PAGE_SIZE)
152                 qty = PAGE_SIZE;
153         else
154                 qty = latter;
155         qty /= sizeof(union afs_dir_block);
156 
157         /* check them */
158         dbuf = page_address(page);
159         for (tmp = 0; tmp < qty; tmp++) {
160                 if (dbuf->blocks[tmp].pagehdr.magic != AFS_DIR_MAGIC) {
161                         printk("kAFS: %s(%lu): bad magic %d/%d is %04hx\n",
162                                __FUNCTION__, dir->i_ino, tmp, qty,
163                                ntohs(dbuf->blocks[tmp].pagehdr.magic));
164                         goto error;
165                 }
166         }
167 
168         SetPageChecked(page);
169         return;
170 
171 error:
172         SetPageChecked(page);
173         SetPageError(page);
174 }
175 
176 /*
177  * discard a page cached in the pagecache
178  */
179 static inline void afs_dir_put_page(struct page *page)
180 {
181         kunmap(page);
182         page_cache_release(page);
183 }
184 
185 /*
186  * get a page into the pagecache
187  */
188 static struct page *afs_dir_get_page(struct inode *dir, unsigned long index,
189                                      struct key *key)
190 {
191         struct page *page;
192         struct file file = {
193                 .private_data = key,
194         };
195 
196         _enter("{%lu},%lu", dir->i_ino, index);
197 
198         page = read_mapping_page(dir->i_mapping, index, &file);
199         if (!IS_ERR(page)) {
200                 kmap(page);
201                 if (!PageChecked(page))
202                         afs_dir_check_page(dir, page);
203                 if (PageError(page))
204                         goto fail;
205         }
206         return page;
207 
208 fail:
209         afs_dir_put_page(page);
210         _leave(" = -EIO");
211         return ERR_PTR(-EIO);
212 }
213 
214 /*
215  * open an AFS directory file
216  */
217 static int afs_dir_open(struct inode *inode, struct file *file)
218 {
219         _enter("{%lu}", inode->i_ino);
220 
221         BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
222         BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
223 
224         if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(inode)->flags))
225                 return -ENOENT;
226 
227         return afs_open(inode, file);
228 }
229 
230 /*
231  * deal with one block in an AFS directory
232  */
233 static int afs_dir_iterate_block(unsigned *fpos,
234                                  union afs_dir_block *block,
235                                  unsigned blkoff,
236                                  void *cookie,
237                                  filldir_t filldir)
238 {
239         union afs_dirent *dire;
240         unsigned offset, next, curr;
241         size_t nlen;
242         int tmp, ret;
243 
244         _enter("%u,%x,%p,,",*fpos,blkoff,block);
245 
246         curr = (*fpos - blkoff) / sizeof(union afs_dirent);
247 
248         /* walk through the block, an entry at a time */
249         for (offset = AFS_DIRENT_PER_BLOCK - block->pagehdr.nentries;
250              offset < AFS_DIRENT_PER_BLOCK;
251              offset = next
252              ) {
253                 next = offset + 1;
254 
255                 /* skip entries marked unused in the bitmap */
256                 if (!(block->pagehdr.bitmap[offset / 8] &
257                       (1 << (offset % 8)))) {
258                         _debug("ENT[%Zu.%u]: unused",
259                                blkoff / sizeof(union afs_dir_block), offset);
260                         if (offset >= curr)
261                                 *fpos = blkoff +
262                                         next * sizeof(union afs_dirent);
263                         continue;
264                 }
265 
266                 /* got a valid entry */
267                 dire = &block->dirents[offset];
268                 nlen = strnlen(dire->u.name,
269                                sizeof(*block) -
270                                offset * sizeof(union afs_dirent));
271 
272                 _debug("ENT[%Zu.%u]: %s %Zu \"%s\"",
273                        blkoff / sizeof(union afs_dir_block), offset,
274                        (offset < curr ? "skip" : "fill"),
275                        nlen, dire->u.name);
276 
277                 /* work out where the next possible entry is */
278                 for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_dirent)) {
279                         if (next >= AFS_DIRENT_PER_BLOCK) {
280                                 _debug("ENT[%Zu.%u]:"
281                                        " %u travelled beyond end dir block"
282                                        " (len %u/%Zu)",
283                                        blkoff / sizeof(union afs_dir_block),
284                                        offset, next, tmp, nlen);
285                                 return -EIO;
286                         }
287                         if (!(block->pagehdr.bitmap[next / 8] &
288                               (1 << (next % 8)))) {
289                                 _debug("ENT[%Zu.%u]:"
290                                        " %u unmarked extension (len %u/%Zu)",
291                                        blkoff / sizeof(union afs_dir_block),
292                                        offset, next, tmp, nlen);
293                                 return -EIO;
294                         }
295 
296                         _debug("ENT[%Zu.%u]: ext %u/%Zu",
297                                blkoff / sizeof(union afs_dir_block),
298                                next, tmp, nlen);
299                         next++;
300                 }
301 
302                 /* skip if starts before the current position */
303                 if (offset < curr)
304                         continue;
305 
306                 /* found the next entry */
307                 ret = filldir(cookie,
308                               dire->u.name,
309                               nlen,
310                               blkoff + offset * sizeof(union afs_dirent),
311                               ntohl(dire->u.vnode),
312                               filldir == afs_lookup_filldir ?
313                               ntohl(dire->u.unique) : DT_UNKNOWN);
314                 if (ret < 0) {
315                         _leave(" = 0 [full]");
316                         return 0;
317                 }
318 
319                 *fpos = blkoff + next * sizeof(union afs_dirent);
320         }
321 
322         _leave(" = 1 [more]");
323         return 1;
324 }
325 
326 /*
327  * iterate through the data blob that lists the contents of an AFS directory
328  */
329 static int afs_dir_iterate(struct inode *dir, unsigned *fpos, void *cookie,
330                            filldir_t filldir, struct key *key)
331 {
332         union afs_dir_block *dblock;
333         struct afs_dir_page *dbuf;
334         struct page *page;
335         unsigned blkoff, limit;
336         int ret;
337 
338         _enter("{%lu},%u,,", dir->i_ino, *fpos);
339 
340         if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dir)->flags)) {
341                 _leave(" = -ESTALE");
342                 return -ESTALE;
343         }
344 
345         /* round the file position up to the next entry boundary */
346         *fpos += sizeof(union afs_dirent) - 1;
347         *fpos &= ~(sizeof(union afs_dirent) - 1);
348 
349         /* walk through the blocks in sequence */
350         ret = 0;
351         while (*fpos < dir->i_size) {
352                 blkoff = *fpos & ~(sizeof(union afs_dir_block) - 1);
353 
354                 /* fetch the appropriate page from the directory */
355                 page = afs_dir_get_page(dir, blkoff / PAGE_SIZE, key);
356                 if (IS_ERR(page)) {
357                         ret = PTR_ERR(page);
358                         break;
359                 }
360 
361                 limit = blkoff & ~(PAGE_SIZE - 1);
362 
363                 dbuf = page_address(page);
364 
365                 /* deal with the individual blocks stashed on this page */
366                 do {
367                         dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
368                                                sizeof(union afs_dir_block)];
369                         ret = afs_dir_iterate_block(fpos, dblock, blkoff,
370                                                     cookie, filldir);
371                         if (ret != 1) {
372                                 afs_dir_put_page(page);
373                                 goto out;
374                         }
375 
376                         blkoff += sizeof(union afs_dir_block);
377 
378                 } while (*fpos < dir->i_size && blkoff < limit);
379 
380                 afs_dir_put_page(page);
381                 ret = 0;
382         }
383 
384 out:
385         _leave(" = %d", ret);
386         return ret;
387 }
388 
389 /*
390  * read an AFS directory
391  */
392 static int afs_readdir(struct file *file, void *cookie, filldir_t filldir)
393 {
394         unsigned fpos;
395         int ret;
396 
397         _enter("{%Ld,{%lu}}",
398                file->f_pos, file->f_path.dentry->d_inode->i_ino);
399 
400         ASSERT(file->private_data != NULL);
401 
402         fpos = file->f_pos;
403         ret = afs_dir_iterate(file->f_path.dentry->d_inode, &fpos,
404                               cookie, filldir, file->private_data);
405         file->f_pos = fpos;
406 
407         _leave(" = %d", ret);
408         return ret;
409 }
410 
411 /*
412  * search the directory for a name
413  * - if afs_dir_iterate_block() spots this function, it'll pass the FID
414  *   uniquifier through dtype
415  */
416 static int afs_lookup_filldir(void *_cookie, const char *name, int nlen,
417                               loff_t fpos, u64 ino, unsigned dtype)
418 {
419         struct afs_lookup_cookie *cookie = _cookie;
420 
421         _enter("{%s,%Zu},%s,%u,,%llu,%u",
422                cookie->name, cookie->nlen, name, nlen,
423                (unsigned long long) ino, dtype);
424 
425         /* insanity checks first */
426         BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
427         BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
428 
429         if (cookie->nlen != nlen || memcmp(cookie->name, name, nlen) != 0) {
430                 _leave(" = 0 [no]");
431                 return 0;
432         }
433 
434         cookie->fid.vnode = ino;
435         cookie->fid.unique = dtype;
436         cookie->found = 1;
437 
438         _leave(" = -1 [found]");
439         return -1;
440 }
441 
442 /*
443  * do a lookup in a directory
444  * - just returns the FID the dentry name maps to if found
445  */
446 static int afs_do_lookup(struct inode *dir, struct dentry *dentry,
447                          struct afs_fid *fid, struct key *key)
448 {
449         struct afs_lookup_cookie cookie;
450         struct afs_super_info *as;
451         unsigned fpos;
452         int ret;
453 
454         _enter("{%lu},%p{%s},", dir->i_ino, dentry, dentry->d_name.name);
455 
456         as = dir->i_sb->s_fs_info;
457 
458         /* search the directory */
459         cookie.name     = dentry->d_name.name;
460         cookie.nlen     = dentry->d_name.len;
461         cookie.fid.vid  = as->volume->vid;
462         cookie.found    = 0;
463 
464         fpos = 0;
465         ret = afs_dir_iterate(dir, &fpos, &cookie, afs_lookup_filldir,
466                               key);
467         if (ret < 0) {
468                 _leave(" = %d [iter]", ret);
469                 return ret;
470         }
471 
472         ret = -ENOENT;
473         if (!cookie.found) {
474                 _leave(" = -ENOENT [not found]");
475                 return -ENOENT;
476         }
477 
478         *fid = cookie.fid;
479         _leave(" = 0 { vn=%u u=%u }", fid->vnode, fid->unique);
480         return 0;
481 }
482 
483 /*
484  * look up an entry in a directory
485  */
486 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
487                                  struct nameidata *nd)
488 {
489         struct afs_vnode *vnode;
490         struct afs_fid fid;
491         struct inode *inode;
492         struct key *key;
493         int ret;
494 
495         vnode = AFS_FS_I(dir);
496 
497         _enter("{%x:%u},%p{%s},",
498                vnode->fid.vid, vnode->fid.vnode, dentry, dentry->d_name.name);
499 
500         ASSERTCMP(dentry->d_inode, ==, NULL);
501 
502         if (dentry->d_name.len >= AFSNAMEMAX) {
503                 _leave(" = -ENAMETOOLONG");
504                 return ERR_PTR(-ENAMETOOLONG);
505         }
506 
507         if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
508                 _leave(" = -ESTALE");
509                 return ERR_PTR(-ESTALE);
510         }
511 
512         key = afs_request_key(vnode->volume->cell);
513         if (IS_ERR(key)) {
514                 _leave(" = %ld [key]", PTR_ERR(key));
515                 return ERR_CAST(key);
516         }
517 
518         ret = afs_validate(vnode, key);
519         if (ret < 0) {
520                 key_put(key);
521                 _leave(" = %d [val]", ret);
522                 return ERR_PTR(ret);
523         }
524 
525         ret = afs_do_lookup(dir, dentry, &fid, key);
526         if (ret < 0) {
527                 key_put(key);
528                 if (ret == -ENOENT) {
529                         d_add(dentry, NULL);
530                         _leave(" = NULL [negative]");
531                         return NULL;
532                 }
533                 _leave(" = %d [do]", ret);
534                 return ERR_PTR(ret);
535         }
536         dentry->d_fsdata = (void *)(unsigned long) vnode->status.data_version;
537 
538         /* instantiate the dentry */
539         inode = afs_iget(dir->i_sb, key, &fid, NULL, NULL);
540         key_put(key);
541         if (IS_ERR(inode)) {
542                 _leave(" = %ld", PTR_ERR(inode));
543                 return ERR_CAST(inode);
544         }
545 
546         dentry->d_op = &afs_fs_dentry_operations;
547 
548         d_add(dentry, inode);
549         _leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%llu }",
550                fid.vnode,
551                fid.unique,
552                dentry->d_inode->i_ino,
553                (unsigned long long)dentry->d_inode->i_version);
554 
555         return NULL;
556 }
557 
558 /*
559  * check that a dentry lookup hit has found a valid entry
560  * - NOTE! the hit can be a negative hit too, so we can't assume we have an
561  *   inode
562  */
563 static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
564 {
565         struct afs_vnode *vnode, *dir;
566         struct afs_fid fid;
567         struct dentry *parent;
568         struct key *key;
569         void *dir_version;
570         int ret;
571 
572         vnode = AFS_FS_I(dentry->d_inode);
573 
574         if (dentry->d_inode)
575                 _enter("{v={%x:%u} n=%s fl=%lx},",
576                        vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name,
577                        vnode->flags);
578         else
579                 _enter("{neg n=%s}", dentry->d_name.name);
580 
581         key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell);
582         if (IS_ERR(key))
583                 key = NULL;
584 
585         /* lock down the parent dentry so we can peer at it */
586         parent = dget_parent(dentry);
587         if (!parent->d_inode)
588                 goto out_bad;
589 
590         dir = AFS_FS_I(parent->d_inode);
591 
592         /* validate the parent directory */
593         if (test_bit(AFS_VNODE_MODIFIED, &dir->flags))
594                 afs_validate(dir, key);
595 
596         if (test_bit(AFS_VNODE_DELETED, &dir->flags)) {
597                 _debug("%s: parent dir deleted", dentry->d_name.name);
598                 goto out_bad;
599         }
600 
601         dir_version = (void *) (unsigned long) dir->status.data_version;
602         if (dentry->d_fsdata == dir_version)
603                 goto out_valid; /* the dir contents are unchanged */
604 
605         _debug("dir modified");
606 
607         /* search the directory for this vnode */
608         ret = afs_do_lookup(&dir->vfs_inode, dentry, &fid, key);
609         switch (ret) {
610         case 0:
611                 /* the filename maps to something */
612                 if (!dentry->d_inode)
613                         goto out_bad;
614                 if (is_bad_inode(dentry->d_inode)) {
615                         printk("kAFS: afs_d_revalidate: %s/%s has bad inode\n",
616                                parent->d_name.name, dentry->d_name.name);
617                         goto out_bad;
618                 }
619 
620                 /* if the vnode ID has changed, then the dirent points to a
621                  * different file */
622                 if (fid.vnode != vnode->fid.vnode) {
623                         _debug("%s: dirent changed [%u != %u]",
624                                dentry->d_name.name, fid.vnode,
625                                vnode->fid.vnode);
626                         goto not_found;
627                 }
628 
629                 /* if the vnode ID uniqifier has changed, then the file has
630                  * been deleted and replaced, and the original vnode ID has
631                  * been reused */
632                 if (fid.unique != vnode->fid.unique) {
633                         _debug("%s: file deleted (uq %u -> %u I:%llu)",
634                                dentry->d_name.name, fid.unique,
635                                vnode->fid.unique,
636                                (unsigned long long)dentry->d_inode->i_version);
637                         spin_lock(&vnode->lock);
638                         set_bit(AFS_VNODE_DELETED, &vnode->flags);
639                         spin_unlock(&vnode->lock);
640                         goto not_found;
641                 }
642                 goto out_valid;
643 
644         case -ENOENT:
645                 /* the filename is unknown */
646                 _debug("%s: dirent not found", dentry->d_name.name);
647                 if (dentry->d_inode)
648                         goto not_found;
649                 goto out_valid;
650 
651         default:
652                 _debug("failed to iterate dir %s: %d",
653                        parent->d_name.name, ret);
654                 goto out_bad;
655         }
656 
657 out_valid:
658         dentry->d_fsdata = dir_version;
659 out_skip:
660         dput(parent);
661         key_put(key);
662         _leave(" = 1 [valid]");
663         return 1;
664 
665         /* the dirent, if it exists, now points to a different vnode */
666 not_found:
667         spin_lock(&dentry->d_lock);
668         dentry->d_flags |= DCACHE_NFSFS_RENAMED;
669         spin_unlock(&dentry->d_lock);
670 
671 out_bad:
672         if (dentry->d_inode) {
673                 /* don't unhash if we have submounts */
674                 if (have_submounts(dentry))
675                         goto out_skip;
676         }
677 
678         _debug("dropping dentry %s/%s",
679                parent->d_name.name, dentry->d_name.name);
680         shrink_dcache_parent(dentry);
681         d_drop(dentry);
682         dput(parent);
683         key_put(key);
684 
685         _leave(" = 0 [bad]");
686         return 0;
687 }
688 
689 /*
690  * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
691  * sleep)
692  * - called from dput() when d_count is going to 0.
693  * - return 1 to request dentry be unhashed, 0 otherwise
694  */
695 static int afs_d_delete(struct dentry *dentry)
696 {
697         _enter("%s", dentry->d_name.name);
698 
699         if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
700                 goto zap;
701 
702         if (dentry->d_inode &&
703             test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dentry->d_inode)->flags))
704                         goto zap;
705 
706         _leave(" = 0 [keep]");
707         return 0;
708 
709 zap:
710         _leave(" = 1 [zap]");
711         return 1;
712 }
713 
714 /*
715  * handle dentry release
716  */
717 static void afs_d_release(struct dentry *dentry)
718 {
719         _enter("%s", dentry->d_name.name);
720 }
721 
722 /*
723  * create a directory on an AFS filesystem
724  */
725 static int afs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
726 {
727         struct afs_file_status status;
728         struct afs_callback cb;
729         struct afs_server *server;
730         struct afs_vnode *dvnode, *vnode;
731         struct afs_fid fid;
732         struct inode *inode;
733         struct key *key;
734         int ret;
735 
736         dvnode = AFS_FS_I(dir);
737 
738         _enter("{%x:%u},{%s},%o",
739                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
740 
741         ret = -ENAMETOOLONG;
742         if (dentry->d_name.len >= AFSNAMEMAX)
743                 goto error;
744 
745         key = afs_request_key(dvnode->volume->cell);
746         if (IS_ERR(key)) {
747                 ret = PTR_ERR(key);
748                 goto error;
749         }
750 
751         mode |= S_IFDIR;
752         ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
753                                mode, &fid, &status, &cb, &server);
754         if (ret < 0)
755                 goto mkdir_error;
756 
757         inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
758         if (IS_ERR(inode)) {
759                 /* ENOMEM at a really inconvenient time - just abandon the new
760                  * directory on the server */
761                 ret = PTR_ERR(inode);
762                 goto iget_error;
763         }
764 
765         /* apply the status report we've got for the new vnode */
766         vnode = AFS_FS_I(inode);
767         spin_lock(&vnode->lock);
768         vnode->update_cnt++;
769         spin_unlock(&vnode->lock);
770         afs_vnode_finalise_status_update(vnode, server);
771         afs_put_server(server);
772 
773         d_instantiate(dentry, inode);
774         if (d_unhashed(dentry)) {
775                 _debug("not hashed");
776                 d_rehash(dentry);
777         }
778         key_put(key);
779         _leave(" = 0");
780         return 0;
781 
782 iget_error:
783         afs_put_server(server);
784 mkdir_error:
785         key_put(key);
786 error:
787         d_drop(dentry);
788         _leave(" = %d", ret);
789         return ret;
790 }
791 
792 /*
793  * remove a directory from an AFS filesystem
794  */
795 static int afs_rmdir(struct inode *dir, struct dentry *dentry)
796 {
797         struct afs_vnode *dvnode, *vnode;
798         struct key *key;
799         int ret;
800 
801         dvnode = AFS_FS_I(dir);
802 
803         _enter("{%x:%u},{%s}",
804                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
805 
806         ret = -ENAMETOOLONG;
807         if (dentry->d_name.len >= AFSNAMEMAX)
808                 goto error;
809 
810         key = afs_request_key(dvnode->volume->cell);
811         if (IS_ERR(key)) {
812                 ret = PTR_ERR(key);
813                 goto error;
814         }
815 
816         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, true);
817         if (ret < 0)
818                 goto rmdir_error;
819 
820         if (dentry->d_inode) {
821                 vnode = AFS_FS_I(dentry->d_inode);
822                 clear_nlink(&vnode->vfs_inode);
823                 set_bit(AFS_VNODE_DELETED, &vnode->flags);
824                 afs_discard_callback_on_delete(vnode);
825         }
826 
827         key_put(key);
828         _leave(" = 0");
829         return 0;
830 
831 rmdir_error:
832         key_put(key);
833 error:
834         _leave(" = %d", ret);
835         return ret;
836 }
837 
838 /*
839  * remove a file from an AFS filesystem
840  */
841 static int afs_unlink(struct inode *dir, struct dentry *dentry)
842 {
843         struct afs_vnode *dvnode, *vnode;
844         struct key *key;
845         int ret;
846 
847         dvnode = AFS_FS_I(dir);
848 
849         _enter("{%x:%u},{%s}",
850                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
851 
852         ret = -ENAMETOOLONG;
853         if (dentry->d_name.len >= AFSNAMEMAX)
854                 goto error;
855 
856         key = afs_request_key(dvnode->volume->cell);
857         if (IS_ERR(key)) {
858                 ret = PTR_ERR(key);
859                 goto error;
860         }
861 
862         if (dentry->d_inode) {
863                 vnode = AFS_FS_I(dentry->d_inode);
864 
865                 /* make sure we have a callback promise on the victim */
866                 ret = afs_validate(vnode, key);
867                 if (ret < 0)
868                         goto error;
869         }
870 
871         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, false);
872         if (ret < 0)
873                 goto remove_error;
874 
875         if (dentry->d_inode) {
876                 /* if the file wasn't deleted due to excess hard links, the
877                  * fileserver will break the callback promise on the file - if
878                  * it had one - before it returns to us, and if it was deleted,
879                  * it won't
880                  *
881                  * however, if we didn't have a callback promise outstanding,
882                  * or it was outstanding on a different server, then it won't
883                  * break it either...
884                  */
885                 vnode = AFS_FS_I(dentry->d_inode);
886                 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
887                         _debug("AFS_VNODE_DELETED");
888                 if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags))
889                         _debug("AFS_VNODE_CB_BROKEN");
890                 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
891                 ret = afs_validate(vnode, key);
892                 _debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret);
893         }
894 
895         key_put(key);
896         _leave(" = 0");
897         return 0;
898 
899 remove_error:
900         key_put(key);
901 error:
902         _leave(" = %d", ret);
903         return ret;
904 }
905 
906 /*
907  * create a regular file on an AFS filesystem
908  */
909 static int afs_create(struct inode *dir, struct dentry *dentry, int mode,
910                       struct nameidata *nd)
911 {
912         struct afs_file_status status;
913         struct afs_callback cb;
914         struct afs_server *server;
915         struct afs_vnode *dvnode, *vnode;
916         struct afs_fid fid;
917         struct inode *inode;
918         struct key *key;
919         int ret;
920 
921         dvnode = AFS_FS_I(dir);
922 
923         _enter("{%x:%u},{%s},%o,",
924                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
925 
926         ret = -ENAMETOOLONG;
927         if (dentry->d_name.len >= AFSNAMEMAX)
928                 goto error;
929 
930         key = afs_request_key(dvnode->volume->cell);
931         if (IS_ERR(key)) {
932                 ret = PTR_ERR(key);
933                 goto error;
934         }
935 
936         mode |= S_IFREG;
937         ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
938                                mode, &fid, &status, &cb, &server);
939         if (ret < 0)
940                 goto create_error;
941 
942         inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
943         if (IS_ERR(inode)) {
944                 /* ENOMEM at a really inconvenient time - just abandon the new
945                  * directory on the server */
946                 ret = PTR_ERR(inode);
947                 goto iget_error;
948         }
949 
950         /* apply the status report we've got for the new vnode */
951         vnode = AFS_FS_I(inode);
952         spin_lock(&vnode->lock);
953         vnode->update_cnt++;
954         spin_unlock(&vnode->lock);
955         afs_vnode_finalise_status_update(vnode, server);
956         afs_put_server(server);
957 
958         d_instantiate(dentry, inode);
959         if (d_unhashed(dentry)) {
960                 _debug("not hashed");
961                 d_rehash(dentry);
962         }
963         key_put(key);
964         _leave(" = 0");
965         return 0;
966 
967 iget_error:
968         afs_put_server(server);
969 create_error:
970         key_put(key);
971 error:
972         d_drop(dentry);
973         _leave(" = %d", ret);
974         return ret;
975 }
976 
977 /*
978  * create a hard link between files in an AFS filesystem
979  */
980 static int afs_link(struct dentry *from, struct inode *dir,
981                     struct dentry *dentry)
982 {
983         struct afs_vnode *dvnode, *vnode;
984         struct key *key;
985         int ret;
986 
987         vnode = AFS_FS_I(from->d_inode);
988         dvnode = AFS_FS_I(dir);
989 
990         _enter("{%x:%u},{%x:%u},{%s}",
991                vnode->fid.vid, vnode->fid.vnode,
992                dvnode->fid.vid, dvnode->fid.vnode,
993                dentry->d_name.name);
994 
995         ret = -ENAMETOOLONG;
996         if (dentry->d_name.len >= AFSNAMEMAX)
997                 goto error;
998 
999         key = afs_request_key(dvnode->volume->cell);
1000         if (IS_ERR(key)) {
1001                 ret = PTR_ERR(key);
1002                 goto error;
1003         }
1004 
1005         ret = afs_vnode_link(dvnode, vnode, key, dentry->d_name.name);
1006         if (ret < 0)
1007                 goto link_error;
1008 
1009         atomic_inc(&vnode->vfs_inode.i_count);
1010         d_instantiate(dentry, &vnode->vfs_inode);
1011         key_put(key);
1012         _leave(" = 0");
1013         return 0;
1014 
1015 link_error:
1016         key_put(key);
1017 error:
1018         d_drop(dentry);
1019         _leave(" = %d", ret);
1020         return ret;
1021 }
1022 
1023 /*
1024  * create a symlink in an AFS filesystem
1025  */
1026 static int afs_symlink(struct inode *dir, struct dentry *dentry,
1027                        const char *content)
1028 {
1029         struct afs_file_status status;
1030         struct afs_server *server;
1031         struct afs_vnode *dvnode, *vnode;
1032         struct afs_fid fid;
1033         struct inode *inode;
1034         struct key *key;
1035         int ret;
1036 
1037         dvnode = AFS_FS_I(dir);
1038 
1039         _enter("{%x:%u},{%s},%s",
1040                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name,
1041                content);
1042 
1043         ret = -ENAMETOOLONG;
1044         if (dentry->d_name.len >= AFSNAMEMAX)
1045                 goto error;
1046 
1047         ret = -EINVAL;
1048         if (strlen(content) >= AFSPATHMAX)
1049                 goto error;
1050 
1051         key = afs_request_key(dvnode->volume->cell);
1052         if (IS_ERR(key)) {
1053                 ret = PTR_ERR(key);
1054                 goto error;
1055         }
1056 
1057         ret = afs_vnode_symlink(dvnode, key, dentry->d_name.name, content,
1058                                 &fid, &status, &server);
1059         if (ret < 0)
1060                 goto create_error;
1061 
1062         inode = afs_iget(dir->i_sb, key, &fid, &status, NULL);
1063         if (IS_ERR(inode)) {
1064                 /* ENOMEM at a really inconvenient time - just abandon the new
1065                  * directory on the server */
1066                 ret = PTR_ERR(inode);
1067                 goto iget_error;
1068         }
1069 
1070         /* apply the status report we've got for the new vnode */
1071         vnode = AFS_FS_I(inode);
1072         spin_lock(&vnode->lock);
1073         vnode->update_cnt++;
1074         spin_unlock(&vnode->lock);
1075         afs_vnode_finalise_status_update(vnode, server);
1076         afs_put_server(server);
1077 
1078         d_instantiate(dentry, inode);
1079         if (d_unhashed(dentry)) {
1080                 _debug("not hashed");
1081                 d_rehash(dentry);
1082         }
1083         key_put(key);
1084         _leave(" = 0");
1085         return 0;
1086 
1087 iget_error:
1088         afs_put_server(server);
1089 create_error:
1090         key_put(key);
1091 error:
1092         d_drop(dentry);
1093         _leave(" = %d", ret);
1094         return ret;
1095 }
1096 
1097 /*
1098  * rename a file in an AFS filesystem and/or move it between directories
1099  */
1100 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
1101                       struct inode *new_dir, struct dentry *new_dentry)
1102 {
1103         struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
1104         struct key *key;
1105         int ret;
1106 
1107         vnode = AFS_FS_I(old_dentry->d_inode);
1108         orig_dvnode = AFS_FS_I(old_dir);
1109         new_dvnode = AFS_FS_I(new_dir);
1110 
1111         _enter("{%x:%u},{%x:%u},{%x:%u},{%s}",
1112                orig_dvnode->fid.vid, orig_dvnode->fid.vnode,
1113                vnode->fid.vid, vnode->fid.vnode,
1114                new_dvnode->fid.vid, new_dvnode->fid.vnode,
1115                new_dentry->d_name.name);
1116 
1117         ret = -ENAMETOOLONG;
1118         if (new_dentry->d_name.len >= AFSNAMEMAX)
1119                 goto error;
1120 
1121         key = afs_request_key(orig_dvnode->volume->cell);
1122         if (IS_ERR(key)) {
1123                 ret = PTR_ERR(key);
1124                 goto error;
1125         }
1126 
1127         ret = afs_vnode_rename(orig_dvnode, new_dvnode, key,
1128                                old_dentry->d_name.name,
1129                                new_dentry->d_name.name);
1130         if (ret < 0)
1131                 goto rename_error;
1132         key_put(key);
1133         _leave(" = 0");
1134         return 0;
1135 
1136 rename_error:
1137         key_put(key);
1138 error:
1139         d_drop(new_dentry);
1140         _leave(" = %d", ret);
1141         return ret;
1142 }
1143 
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