diff options
Diffstat (limited to 'fs/libfs.c')
| -rw-r--r-- | fs/libfs.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/fs/libfs.c b/fs/libfs.c index 8117b24b929d..38950cce135b 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -1311,6 +1311,47 @@ ssize_t simple_attr_write_signed(struct file *file, const char __user *buf, EXPORT_SYMBOL_GPL(simple_attr_write_signed); /** + * generic_encode_ino32_fh - generic export_operations->encode_fh function + * @inode: the object to encode + * @fh: where to store the file handle fragment + * @max_len: maximum length to store there (in 4 byte units) + * @parent: parent directory inode, if wanted + * + * This generic encode_fh function assumes that the 32 inode number + * is suitable for locating an inode, and that the generation number + * can be used to check that it is still valid. It places them in the + * filehandle fragment where export_decode_fh expects to find them. + */ +int generic_encode_ino32_fh(struct inode *inode, __u32 *fh, int *max_len, + struct inode *parent) +{ + struct fid *fid = (void *)fh; + int len = *max_len; + int type = FILEID_INO32_GEN; + + if (parent && (len < 4)) { + *max_len = 4; + return FILEID_INVALID; + } else if (len < 2) { + *max_len = 2; + return FILEID_INVALID; + } + + len = 2; + fid->i32.ino = inode->i_ino; + fid->i32.gen = inode->i_generation; + if (parent) { + fid->i32.parent_ino = parent->i_ino; + fid->i32.parent_gen = parent->i_generation; + len = 4; + type = FILEID_INO32_GEN_PARENT; + } + *max_len = len; + return type; +} +EXPORT_SYMBOL_GPL(generic_encode_ino32_fh); + +/** * generic_fh_to_dentry - generic helper for the fh_to_dentry export operation * @sb: filesystem to do the file handle conversion on * @fid: file handle to convert |