diff options
Diffstat (limited to 'fs/debugfs')
| -rw-r--r-- | fs/debugfs/inode.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 1e30f74a9527..7fd4ec4bb214 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -248,6 +248,42 @@ static struct file_system_type debug_fs_type = { }; MODULE_ALIAS_FS("debugfs"); +/** + * debugfs_lookup() - look up an existing debugfs file + * @name: a pointer to a string containing the name of the file to look up. + * @parent: a pointer to the parent dentry of the file. + * + * This function will return a pointer to a dentry if it succeeds. If the file + * doesn't exist or an error occurs, %NULL will be returned. The returned + * dentry must be passed to dput() when it is no longer needed. + * + * If debugfs is not enabled in the kernel, the value -%ENODEV will be + * returned. + */ +struct dentry *debugfs_lookup(const char *name, struct dentry *parent) +{ + struct dentry *dentry; + + if (IS_ERR(parent)) + return NULL; + + if (!parent) + parent = debugfs_mount->mnt_root; + + inode_lock(d_inode(parent)); + dentry = lookup_one_len(name, parent, strlen(name)); + inode_unlock(d_inode(parent)); + + if (IS_ERR(dentry)) + return NULL; + if (!d_really_is_positive(dentry)) { + dput(dentry); + return NULL; + } + return dentry; +} +EXPORT_SYMBOL_GPL(debugfs_lookup); + static struct dentry *start_creating(const char *name, struct dentry *parent) { struct dentry *dentry; |