Not all filesystems will necessarily be able to support relinking an
orphan inode back into the filesystem. Some offlist feedback suggested
that instead of overloading .link that relinking should be a separate
file operation for this reason.
Since .relink is a superset of .link make the VFS call .relink where
possible and .link otherwise.
The next commit will change ext3/4 to enable this operation.
Signed-off-by: Matt Helsley <matthltc@xxxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Cc: linux-ext4@xxxxxxxxxxxxxxx
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/namei.c | 5 ++++-
include/linux/fs.h | 1 +
2 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 4ff7ca5..b6b7359 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2430,7 +2430,10 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de
return error;
mutex_lock(&inode->i_mutex);
- error = dir->i_op->link(old_dentry, dir, new_dentry);
+ if (dir->i_op->relink)
+ error = dir->i_op->relink(old_dentry, dir, new_dentry);
+ else
+ error = dir->i_op->link(old_dentry, dir, new_dentry);
mutex_unlock(&inode->i_mutex);
if (!error)
fsnotify_link(dir, inode, new_dentry);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3d8bf75..af1cb0e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1562,6 +1562,7 @@ struct inode_operations {
int (*create) (struct inode *,struct dentry *,int, struct nameidata *);
struct dentry * (*lookup) (struct inode *,struct dentry *, struct nameidata *);
int (*link) (struct dentry *,struct inode *,struct dentry *);
+ int (*relink) (struct dentry *,struct inode *,struct dentry *);
int (*unlink) (struct inode *,struct dentry *);
int (*symlink) (struct inode *,struct dentry *,const char *);
int (*mkdir) (struct inode *,struct dentry *,int);
--
1.6.3.3
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