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-rw-r--r--fs/exportfs/expfs.c179
-rw-r--r--fs/nfsd/export.c8
-rw-r--r--include/linux/exportfs.h41
3 files changed, 3 insertions, 225 deletions
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 99294a23cd54..e68f0279f4b0 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -13,19 +13,6 @@ static int get_name(struct dentry *dentry, char *name,
13 struct dentry *child); 13 struct dentry *child);
14 14
15 15
16static struct dentry *exportfs_get_dentry(struct super_block *sb, void *obj)
17{
18 struct dentry *result = ERR_PTR(-ESTALE);
19
20 if (sb->s_export_op->get_dentry) {
21 result = sb->s_export_op->get_dentry(sb, obj);
22 if (!result)
23 result = ERR_PTR(-ESTALE);
24 }
25
26 return result;
27}
28
29static int exportfs_get_name(struct dentry *dir, char *name, 16static int exportfs_get_name(struct dentry *dir, char *name,
30 struct dentry *child) 17 struct dentry *child)
31{ 18{
@@ -214,125 +201,6 @@ reconnect_path(struct super_block *sb, struct dentry *target_dir)
214 return 0; 201 return 0;
215} 202}
216 203
217/**
218 * find_exported_dentry - helper routine to implement export_operations->decode_fh
219 * @sb: The &super_block identifying the filesystem
220 * @obj: An opaque identifier of the object to be found - passed to
221 * get_inode
222 * @parent: An optional opqaue identifier of the parent of the object.
223 * @acceptable: A function used to test possible &dentries to see if they are
224 * acceptable
225 * @context: A parameter to @acceptable so that it knows on what basis to
226 * judge.
227 *
228 * find_exported_dentry is the central helper routine to enable file systems
229 * to provide the decode_fh() export_operation. It's main task is to take
230 * an &inode, find or create an appropriate &dentry structure, and possibly
231 * splice this into the dcache in the correct place.
232 *
233 * The decode_fh() operation provided by the filesystem should call
234 * find_exported_dentry() with the same parameters that it received except
235 * that instead of the file handle fragment, pointers to opaque identifiers
236 * for the object and optionally its parent are passed. The default decode_fh
237 * routine passes one pointer to the start of the filehandle fragment, and
238 * one 8 bytes into the fragment. It is expected that most filesystems will
239 * take this approach, though the offset to the parent identifier may well be
240 * different.
241 *
242 * find_exported_dentry() will call get_dentry to get an dentry pointer from
243 * the file system. If any &dentry in the d_alias list is acceptable, it will
244 * be returned. Otherwise find_exported_dentry() will attempt to splice a new
245 * &dentry into the dcache using get_name() and get_parent() to find the
246 * appropriate place.
247 */
248
249struct dentry *
250find_exported_dentry(struct super_block *sb, void *obj, void *parent,
251 int (*acceptable)(void *context, struct dentry *de),
252 void *context)
253{
254 struct dentry *result, *alias;
255 int err = -ESTALE;
256
257 /*
258 * Attempt to find the inode.
259 */
260 result = exportfs_get_dentry(sb, obj);
261 if (IS_ERR(result))
262 return result;
263
264 if (S_ISDIR(result->d_inode->i_mode)) {
265 if (!(result->d_flags & DCACHE_DISCONNECTED)) {
266 if (acceptable(context, result))
267 return result;
268 err = -EACCES;
269 goto err_result;
270 }
271
272 err = reconnect_path(sb, result);
273 if (err)
274 goto err_result;
275 } else {
276 struct dentry *target_dir, *nresult;
277 char nbuf[NAME_MAX+1];
278
279 alias = find_acceptable_alias(result, acceptable, context);
280 if (alias)
281 return alias;
282
283 if (parent == NULL)
284 goto err_result;
285
286 target_dir = exportfs_get_dentry(sb,parent);
287 if (IS_ERR(target_dir)) {
288 err = PTR_ERR(target_dir);
289 goto err_result;
290 }
291
292 err = reconnect_path(sb, target_dir);
293 if (err) {
294 dput(target_dir);
295 goto err_result;
296 }
297
298 /*
299 * As we weren't after a directory, have one more step to go.
300 */
301 err = exportfs_get_name(target_dir, nbuf, result);
302 if (!err) {
303 mutex_lock(&target_dir->d_inode->i_mutex);
304 nresult = lookup_one_len(nbuf, target_dir,
305 strlen(nbuf));
306 mutex_unlock(&target_dir->d_inode->i_mutex);
307 if (!IS_ERR(nresult)) {
308 if (nresult->d_inode) {
309 dput(result);
310 result = nresult;
311 } else
312 dput(nresult);
313 }
314 }
315 dput(target_dir);
316 }
317
318 alias = find_acceptable_alias(result, acceptable, context);
319 if (alias)
320 return alias;
321
322 /* drat - I just cannot find anything acceptable */
323 dput(result);
324 /* It might be justifiable to return ESTALE here,
325 * but the filehandle at-least looks reasonable good
326 * and it may just be a permission problem, so returning
327 * -EACCESS is safer
328 */
329 return ERR_PTR(-EACCES);
330
331 err_result:
332 dput(result);
333 return ERR_PTR(err);
334}
335
336struct getdents_callback { 204struct getdents_callback {
337 char *name; /* name that was found. It already points to a 205 char *name; /* name that was found. It already points to a
338 buffer NAME_MAX+1 is size */ 206 buffer NAME_MAX+1 is size */
@@ -462,38 +330,6 @@ static int export_encode_fh(struct dentry *dentry, struct fid *fid,
462 return type; 330 return type;
463} 331}
464 332
465
466/**
467 * export_decode_fh - default export_operations->decode_fh function
468 * @sb: The superblock
469 * @fh: pointer to the file handle fragment
470 * @fh_len: length of file handle fragment
471 * @acceptable: function for testing acceptability of dentrys
472 * @context: context for @acceptable
473 *
474 * This is the default decode_fh() function.
475 * a fileid_type of 1 indicates that the filehandlefragment
476 * just contains an object identifier understood by get_dentry.
477 * a fileid_type of 2 says that there is also a directory
478 * identifier 8 bytes in to the filehandlefragement.
479 */
480static struct dentry *export_decode_fh(struct super_block *sb, __u32 *fh, int fh_len,
481 int fileid_type,
482 int (*acceptable)(void *context, struct dentry *de),
483 void *context)
484{
485 __u32 parent[2];
486 parent[0] = parent[1] = 0;
487 if (fh_len < 2 || fileid_type > 2)
488 return NULL;
489 if (fileid_type == 2) {
490 if (fh_len > 2) parent[0] = fh[2];
491 if (fh_len > 3) parent[1] = fh[3];
492 }
493 return find_exported_dentry(sb, fh, parent,
494 acceptable, context);
495}
496
497int exportfs_encode_fh(struct dentry *dentry, struct fid *fid, int *max_len, 333int exportfs_encode_fh(struct dentry *dentry, struct fid *fid, int *max_len,
498 int connectable) 334 int connectable)
499{ 335{
@@ -518,19 +354,6 @@ struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
518 int err; 354 int err;
519 355
520 /* 356 /*
521 * Old way of doing things. Will go away soon.
522 */
523 if (!nop->fh_to_dentry) {
524 if (nop->decode_fh) {
525 return nop->decode_fh(mnt->mnt_sb, fid->raw, fh_len,
526 fileid_type, acceptable, context);
527 } else {
528 return export_decode_fh(mnt->mnt_sb, fid->raw, fh_len,
529 fileid_type, acceptable, context);
530 }
531 }
532
533 /*
534 * Try to get any dentry for the given file handle from the filesystem. 357 * Try to get any dentry for the given file handle from the filesystem.
535 */ 358 */
536 result = nop->fh_to_dentry(mnt->mnt_sb, fid, fh_len, fileid_type); 359 result = nop->fh_to_dentry(mnt->mnt_sb, fid, fh_len, fileid_type);
@@ -652,6 +475,4 @@ struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
652} 475}
653EXPORT_SYMBOL_GPL(exportfs_decode_fh); 476EXPORT_SYMBOL_GPL(exportfs_decode_fh);
654 477
655EXPORT_SYMBOL(find_exported_dentry);
656
657MODULE_LICENSE("GPL"); 478MODULE_LICENSE("GPL");
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 04b266729802..66d0aeb32a47 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -386,15 +386,13 @@ static int check_export(struct inode *inode, int flags, unsigned char *uuid)
386 dprintk("exp_export: export of non-dev fs without fsid\n"); 386 dprintk("exp_export: export of non-dev fs without fsid\n");
387 return -EINVAL; 387 return -EINVAL;
388 } 388 }
389 if (!inode->i_sb->s_export_op) { 389
390 if (!inode->i_sb->s_export_op ||
391 !inode->i_sb->s_export_op->fh_to_dentry) {
390 dprintk("exp_export: export of invalid fs type.\n"); 392 dprintk("exp_export: export of invalid fs type.\n");
391 return -EINVAL; 393 return -EINVAL;
392 } 394 }
393 395
394 /* Ok, we can export it */;
395 if (!inode->i_sb->s_export_op->find_exported_dentry)
396 inode->i_sb->s_export_op->find_exported_dentry =
397 find_exported_dentry;
398 return 0; 396 return 0;
399 397
400} 398}
diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h
index b44f6b6871c8..0b4a771b4903 100644
--- a/include/linux/exportfs.h
+++ b/include/linux/exportfs.h
@@ -54,8 +54,6 @@ struct fid {
54 * @get_name: find the name for a given inode in a given directory 54 * @get_name: find the name for a given inode in a given directory
55 * @get_parent: find the parent of a given directory 55 * @get_parent: find the parent of a given directory
56 * @get_dentry: find a dentry for the inode given a file handle sub-fragment 56 * @get_dentry: find a dentry for the inode given a file handle sub-fragment
57 * @find_exported_dentry:
58 * set by the exporting module to a standard helper function.
59 * 57 *
60 * Description: 58 * Description:
61 * The export_operations structure provides a means for nfsd to communicate 59 * The export_operations structure provides a means for nfsd to communicate
@@ -82,16 +80,6 @@ struct fid {
82 * looking for the next. As soon as an acceptable one is found, it should 80 * looking for the next. As soon as an acceptable one is found, it should
83 * be returned. 81 * be returned.
84 * 82 *
85 * decode_fh:
86 * @decode_fh is given a &struct super_block (@sb), a file handle fragment
87 * (@fh, @fh_len) and an acceptability testing function (@acceptable,
88 * @context). It should return a &struct dentry which refers to the same
89 * file that the file handle fragment refers to, and which passes the
90 * acceptability test. If it cannot, it should return a %NULL pointer if
91 * the file was found but no acceptable &dentries were available, or a
92 * %ERR_PTR error code indicating why it couldn't be found (e.g. %ENOENT or
93 * %ENOMEM).
94 *
95 * encode_fh: 83 * encode_fh:
96 * @encode_fh should store in the file handle fragment @fh (using at most 84 * @encode_fh should store in the file handle fragment @fh (using at most
97 * @max_len bytes) information that can be used by @decode_fh to recover the 85 * @max_len bytes) information that can be used by @decode_fh to recover the
@@ -129,30 +117,12 @@ struct fid {
129 * is also a directory. In the event that it cannot be found, or storage 117 * is also a directory. In the event that it cannot be found, or storage
130 * space cannot be allocated, a %ERR_PTR should be returned. 118 * space cannot be allocated, a %ERR_PTR should be returned.
131 * 119 *
132 * get_dentry:
133 * Given a &super_block (@sb) and a pointer to a file-system specific inode
134 * identifier, possibly an inode number, (@inump) get_dentry() should find
135 * the identified inode and return a dentry for that inode. Any suitable
136 * dentry can be returned including, if necessary, a new dentry created with
137 * d_alloc_root. The caller can then find any other extant dentrys by
138 * following the d_alias links. If a new dentry was created using
139 * d_alloc_root, DCACHE_NFSD_DISCONNECTED should be set, and the dentry
140 * should be d_rehash()ed.
141 *
142 * If the inode cannot be found, either a %NULL pointer or an %ERR_PTR code
143 * can be returned. The @inump will be whatever was passed to
144 * nfsd_find_fh_dentry() in either the @obj or @parent parameters.
145 *
146 * Locking rules: 120 * Locking rules:
147 * get_parent is called with child->d_inode->i_mutex down 121 * get_parent is called with child->d_inode->i_mutex down
148 * get_name is not (which is possibly inconsistent) 122 * get_name is not (which is possibly inconsistent)
149 */ 123 */
150 124
151struct export_operations { 125struct export_operations {
152 struct dentry *(*decode_fh)(struct super_block *sb, __u32 *fh,
153 int fh_len, int fh_type,
154 int (*acceptable)(void *context, struct dentry *de),
155 void *context);
156 int (*encode_fh)(struct dentry *de, __u32 *fh, int *max_len, 126 int (*encode_fh)(struct dentry *de, __u32 *fh, int *max_len,
157 int connectable); 127 int connectable);
158 struct dentry * (*fh_to_dentry)(struct super_block *sb, struct fid *fid, 128 struct dentry * (*fh_to_dentry)(struct super_block *sb, struct fid *fid,
@@ -162,19 +132,8 @@ struct export_operations {
162 int (*get_name)(struct dentry *parent, char *name, 132 int (*get_name)(struct dentry *parent, char *name,
163 struct dentry *child); 133 struct dentry *child);
164 struct dentry * (*get_parent)(struct dentry *child); 134 struct dentry * (*get_parent)(struct dentry *child);
165 struct dentry * (*get_dentry)(struct super_block *sb, void *inump);
166
167 /* This is set by the exporting module to a standard helper */
168 struct dentry * (*find_exported_dentry)(
169 struct super_block *sb, void *obj, void *parent,
170 int (*acceptable)(void *context, struct dentry *de),
171 void *context);
172}; 135};
173 136
174extern struct dentry *find_exported_dentry(struct super_block *sb, void *obj,
175 void *parent, int (*acceptable)(void *context, struct dentry *de),
176 void *context);
177
178extern int exportfs_encode_fh(struct dentry *dentry, struct fid *fid, 137extern int exportfs_encode_fh(struct dentry *dentry, struct fid *fid,
179 int *max_len, int connectable); 138 int *max_len, int connectable);
180extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid, 139extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,