From 76fca90e9f3abc82114d9d02d8e14e0324a18ca2 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Fri, 9 Dec 2016 16:45:04 +0100 Subject: vfs: default to generic_readlink() If i_op->readlink is NULL, but i_op->get_link is set then vfs_readlink() defaults to calling generic_readlink(). The IOP_DEFAULT_READLINK flag indicates that the above conditions are met and the default action can be taken. Signed-off-by: Miklos Szeredi --- Documentation/filesystems/porting | 4 ++++ Documentation/filesystems/vfs.txt | 9 ++++++--- 2 files changed, 10 insertions(+), 3 deletions(-) (limited to 'Documentation/filesystems') diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index bdd025ceb763..95280079c0b3 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -596,3 +596,7 @@ in your dentry operations instead. [mandatory] ->rename() has an added flags argument. Any flags not handled by the filesystem should result in EINVAL being returned. +-- +[recommended] + ->readlink is optional for symlinks. Don't set, unless filesystem needs + to fake something for readlink(2). diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index b5039a00caaf..038241123ca5 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -451,9 +451,6 @@ otherwise noted. exist; this is checked by the VFS. Unlike plain rename, source and target may be of different type. - readlink: called by the readlink(2) system call. Only required if - you want to support reading symbolic links - get_link: called by the VFS to follow a symbolic link to the inode it points to. Only required if you want to support symbolic links. This method returns the symlink body @@ -468,6 +465,12 @@ otherwise noted. argument. If request can't be handled without leaving RCU mode, have it return ERR_PTR(-ECHILD). + readlink: this is now just an override for use by readlink(2) for the + cases when ->get_link uses nd_jump_link() or object is not in + fact a symlink. Normally filesystems should only implement + ->get_link for symlinks and readlink(2) will automatically use + that. + permission: called by the VFS to check for access rights on a POSIX-like filesystem. -- cgit v1.2.1