2012-06-27 11:06:39

by Cyrill Gorcunov

[permalink] [raw]
Subject: [rfc 6/7] fs, exportfs: Add export_encode_inode_fh helper

To provide fsnotify object inodes being watched without
binding to alphabetical path we need to encode them with
exportfs help. This patch adds a helper which operates
with plain inodes directly.

This feature is CONFIG_CHECKPOINT_RESTORE only.

Signed-off-by: Cyrill Gorcunov <[email protected]>
CC: Al Viro <[email protected]>
CC: Alexey Dobriyan <[email protected]>
CC: Andrew Morton <[email protected]>
CC: Pavel Emelyanov <[email protected]>
CC: James Bottomley <[email protected]>
---
fs/exportfs/expfs.c | 21 +++++++++++++++++++++
include/linux/exportfs.h | 4 ++++
2 files changed, 25 insertions(+)

Index: linux-2.6.git/fs/exportfs/expfs.c
===================================================================
--- linux-2.6.git.orig/fs/exportfs/expfs.c
+++ linux-2.6.git/fs/exportfs/expfs.c
@@ -302,6 +302,27 @@ out:
return error;
}

+#ifdef CONFIG_CHECKPOINT_RESTORE
+int export_encode_inode_fh(struct inode *inode, struct fid *fid, int *max_len)
+{
+ int len = *max_len;
+ int type = FILEID_INO32_GEN;
+
+ if (len < 2) {
+ *max_len = 2;
+ return 255;
+ }
+
+ len = 2;
+ fid->i32.ino = inode->i_ino;
+ fid->i32.gen = inode->i_generation;
+ *max_len = len;
+
+ return type;
+}
+EXPORT_SYMBOL_GPL(export_encode_inode_fh);
+#endif
+
/**
* export_encode_fh - default export_operations->encode_fh function
* @inode: the object to encode
Index: linux-2.6.git/include/linux/exportfs.h
===================================================================
--- linux-2.6.git.orig/include/linux/exportfs.h
+++ linux-2.6.git/include/linux/exportfs.h
@@ -177,6 +177,10 @@ struct export_operations {
int (*commit_metadata)(struct inode *inode);
};

+#ifdef CONFIG_CHECKPOINT_RESTORE
+extern int export_encode_inode_fh(struct inode *inode, struct fid *fid, int *max_len);
+#endif
+
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,