struct dentry *child);
-static struct dentry *exportfs_get_dentry(struct super_block *sb, void *obj)
-{
- struct dentry *result = ERR_PTR(-ESTALE);
-
- if (sb->s_export_op->get_dentry) {
- result = sb->s_export_op->get_dentry(sb, obj);
- if (!result)
- result = ERR_PTR(-ESTALE);
- }
-
- return result;
-}
-
static int exportfs_get_name(struct dentry *dir, char *name,
struct dentry *child)
{
return 0;
}
-/**
- * find_exported_dentry - helper routine to implement export_operations->decode_fh
- * @sb: The &super_block identifying the filesystem
- * @obj: An opaque identifier of the object to be found - passed to
- * get_inode
- * @parent: An optional opqaue identifier of the parent of the object.
- * @acceptable: A function used to test possible &dentries to see if they are
- * acceptable
- * @context: A parameter to @acceptable so that it knows on what basis to
- * judge.
- *
- * find_exported_dentry is the central helper routine to enable file systems
- * to provide the decode_fh() export_operation. It's main task is to take
- * an &inode, find or create an appropriate &dentry structure, and possibly
- * splice this into the dcache in the correct place.
- *
- * The decode_fh() operation provided by the filesystem should call
- * find_exported_dentry() with the same parameters that it received except
- * that instead of the file handle fragment, pointers to opaque identifiers
- * for the object and optionally its parent are passed. The default decode_fh
- * routine passes one pointer to the start of the filehandle fragment, and
- * one 8 bytes into the fragment. It is expected that most filesystems will
- * take this approach, though the offset to the parent identifier may well be
- * different.
- *
- * find_exported_dentry() will call get_dentry to get an dentry pointer from
- * the file system. If any &dentry in the d_alias list is acceptable, it will
- * be returned. Otherwise find_exported_dentry() will attempt to splice a new
- * &dentry into the dcache using get_name() and get_parent() to find the
- * appropriate place.
- */
-
-struct dentry *
-find_exported_dentry(struct super_block *sb, void *obj, void *parent,
- int (*acceptable)(void *context, struct dentry *de),
- void *context)
-{
- struct dentry *result, *alias;
- int err = -ESTALE;
-
- /*
- * Attempt to find the inode.
- */
- result = exportfs_get_dentry(sb, obj);
- if (IS_ERR(result))
- return result;
-
- if (S_ISDIR(result->d_inode->i_mode)) {
- if (!(result->d_flags & DCACHE_DISCONNECTED)) {
- if (acceptable(context, result))
- return result;
- err = -EACCES;
- goto err_result;
- }
-
- err = reconnect_path(sb, result);
- if (err)
- goto err_result;
- } else {
- struct dentry *target_dir, *nresult;
- char nbuf[NAME_MAX+1];
-
- alias = find_acceptable_alias(result, acceptable, context);
- if (alias)
- return alias;
-
- if (parent == NULL)
- goto err_result;
-
- target_dir = exportfs_get_dentry(sb,parent);
- if (IS_ERR(target_dir)) {
- err = PTR_ERR(target_dir);
- goto err_result;
- }
-
- err = reconnect_path(sb, target_dir);
- if (err) {
- dput(target_dir);
- goto err_result;
- }
-
- /*
- * As we weren't after a directory, have one more step to go.
- */
- err = exportfs_get_name(target_dir, nbuf, result);
- if (!err) {
- mutex_lock(&target_dir->d_inode->i_mutex);
- nresult = lookup_one_len(nbuf, target_dir,
- strlen(nbuf));
- mutex_unlock(&target_dir->d_inode->i_mutex);
- if (!IS_ERR(nresult)) {
- if (nresult->d_inode) {
- dput(result);
- result = nresult;
- } else
- dput(nresult);
- }
- }
- dput(target_dir);
- }
-
- alias = find_acceptable_alias(result, acceptable, context);
- if (alias)
- return alias;
-
- /* drat - I just cannot find anything acceptable */
- dput(result);
- /* It might be justifiable to return ESTALE here,
- * but the filehandle at-least looks reasonable good
- * and it may just be a permission problem, so returning
- * -EACCESS is safer
- */
- return ERR_PTR(-EACCES);
-
- err_result:
- dput(result);
- return ERR_PTR(err);
-}
-
struct getdents_callback {
char *name; /* name that was found. It already points to a
buffer NAME_MAX+1 is size */
return type;
}
-
-/**
- * export_decode_fh - default export_operations->decode_fh function
- * @sb: The superblock
- * @fh: pointer to the file handle fragment
- * @fh_len: length of file handle fragment
- * @acceptable: function for testing acceptability of dentrys
- * @context: context for @acceptable
- *
- * This is the default decode_fh() function.
- * a fileid_type of 1 indicates that the filehandlefragment
- * just contains an object identifier understood by get_dentry.
- * a fileid_type of 2 says that there is also a directory
- * identifier 8 bytes in to the filehandlefragement.
- */
-static struct dentry *export_decode_fh(struct super_block *sb, __u32 *fh, int fh_len,
- int fileid_type,
- int (*acceptable)(void *context, struct dentry *de),
- void *context)
-{
- __u32 parent[2];
- parent[0] = parent[1] = 0;
- if (fh_len < 2 || fileid_type > 2)
- return NULL;
- if (fileid_type == 2) {
- if (fh_len > 2) parent[0] = fh[2];
- if (fh_len > 3) parent[1] = fh[3];
- }
- return find_exported_dentry(sb, fh, parent,
- acceptable, context);
-}
-
int exportfs_encode_fh(struct dentry *dentry, struct fid *fid, int *max_len,
int connectable)
{
struct dentry *result, *alias;
int err;
- /*
- * Old way of doing things. Will go away soon.
- */
- if (!nop->fh_to_dentry) {
- if (nop->decode_fh) {
- return nop->decode_fh(mnt->mnt_sb, fid->raw, fh_len,
- fileid_type, acceptable, context);
- } else {
- return export_decode_fh(mnt->mnt_sb, fid->raw, fh_len,
- fileid_type, acceptable, context);
- }
- }
-
/*
* Try to get any dentry for the given file handle from the filesystem.
*/
}
EXPORT_SYMBOL_GPL(exportfs_decode_fh);
-EXPORT_SYMBOL(find_exported_dentry);
-
MODULE_LICENSE("GPL");
* @get_name: find the name for a given inode in a given directory
* @get_parent: find the parent of a given directory
* @get_dentry: find a dentry for the inode given a file handle sub-fragment
- * @find_exported_dentry:
- * set by the exporting module to a standard helper function.
*
* Description:
* The export_operations structure provides a means for nfsd to communicate
* looking for the next. As soon as an acceptable one is found, it should
* be returned.
*
- * decode_fh:
- * @decode_fh is given a &struct super_block (@sb), a file handle fragment
- * (@fh, @fh_len) and an acceptability testing function (@acceptable,
- * @context). It should return a &struct dentry which refers to the same
- * file that the file handle fragment refers to, and which passes the
- * acceptability test. If it cannot, it should return a %NULL pointer if
- * the file was found but no acceptable &dentries were available, or a
- * %ERR_PTR error code indicating why it couldn't be found (e.g. %ENOENT or
- * %ENOMEM).
- *
* encode_fh:
* @encode_fh should store in the file handle fragment @fh (using at most
* @max_len bytes) information that can be used by @decode_fh to recover the
* is also a directory. In the event that it cannot be found, or storage
* space cannot be allocated, a %ERR_PTR should be returned.
*
- * get_dentry:
- * Given a &super_block (@sb) and a pointer to a file-system specific inode
- * identifier, possibly an inode number, (@inump) get_dentry() should find
- * the identified inode and return a dentry for that inode. Any suitable
- * dentry can be returned including, if necessary, a new dentry created with
- * d_alloc_root. The caller can then find any other extant dentrys by
- * following the d_alias links. If a new dentry was created using
- * d_alloc_root, DCACHE_NFSD_DISCONNECTED should be set, and the dentry
- * should be d_rehash()ed.
- *
- * If the inode cannot be found, either a %NULL pointer or an %ERR_PTR code
- * can be returned. The @inump will be whatever was passed to
- * nfsd_find_fh_dentry() in either the @obj or @parent parameters.
- *
* Locking rules:
* get_parent is called with child->d_inode->i_mutex down
* get_name is not (which is possibly inconsistent)
*/
struct export_operations {
- struct dentry *(*decode_fh)(struct super_block *sb, __u32 *fh,
- int fh_len, int fh_type,
- int (*acceptable)(void *context, struct dentry *de),
- void *context);
int (*encode_fh)(struct dentry *de, __u32 *fh, int *max_len,
int connectable);
struct dentry * (*fh_to_dentry)(struct super_block *sb, struct fid *fid,
int (*get_name)(struct dentry *parent, char *name,
struct dentry *child);
struct dentry * (*get_parent)(struct dentry *child);
- struct dentry * (*get_dentry)(struct super_block *sb, void *inump);
-
- /* This is set by the exporting module to a standard helper */
- struct dentry * (*find_exported_dentry)(
- struct super_block *sb, void *obj, void *parent,
- int (*acceptable)(void *context, struct dentry *de),
- void *context);
};
-extern struct dentry *find_exported_dentry(struct super_block *sb, void *obj,
- void *parent, int (*acceptable)(void *context, struct dentry *de),
- void *context);
-
extern int exportfs_encode_fh(struct dentry *dentry, struct fid *fid,
int *max_len, int connectable);
extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
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