libfs: support RENAME_NOREPLACE in simple_rename()

This is trivial to do:

 - add flags argument to simple_rename()
 - check if flags doesn't have any other than RENAME_NOREPLACE
 - assign simple_rename() to .rename2 instead of .rename

Filesystems converted:

hugetlbfs, ramfs, bpf.

Debugfs uses simple_rename() to implement debugfs_rename(), which is for
debugfs instances to rename files internally, not for userspace filesystem
access.  For this case pass zero flags to simple_rename().

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 72361ba..5ac27c9 100644 (file)
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -748,7 +748,7 @@ struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
        old_name = fsnotify_oldname_init(old_dentry->d_name.name);
 
        error = simple_rename(d_inode(old_dir), old_dentry, d_inode(new_dir),
-               dentry);
+                             dentry, 0);
        if (error) {
                fsnotify_oldname_free(old_name);
                goto exit;

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 4ea71eb..50cd747 100644 (file)
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -988,7 +988,7 @@ static const struct inode_operations hugetlbfs_dir_inode_operations = {
        .mkdir          = hugetlbfs_mkdir,
        .rmdir          = simple_rmdir,
        .mknod          = hugetlbfs_mknod,
-       .rename         = simple_rename,
+       .rename2        = simple_rename,
        .setattr        = hugetlbfs_setattr,
 };
 

diff --git a/fs/libfs.c b/fs/libfs.c
index 74dc8b9..4758353 100644 (file)
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -349,11 +349,15 @@ int simple_rmdir(struct inode *dir, struct dentry *dentry)
 EXPORT_SYMBOL(simple_rmdir);
 
 int simple_rename(struct inode *old_dir, struct dentry *old_dentry,
-               struct inode *new_dir, struct dentry *new_dentry)
+                 struct inode *new_dir, struct dentry *new_dentry,
+                 unsigned int flags)
 {
        struct inode *inode = d_inode(old_dentry);
        int they_are_dirs = d_is_dir(old_dentry);
 
+       if (flags & ~RENAME_NOREPLACE)
+               return -EINVAL;
+
        if (!simple_empty(new_dentry))
                return -ENOTEMPTY;
 

diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index 1ab6e6c..c2aa068 100644 (file)
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -146,7 +146,7 @@ static const struct inode_operations ramfs_dir_inode_operations = {
        .mkdir          = ramfs_mkdir,
        .rmdir          = simple_rmdir,
        .mknod          = ramfs_mknod,
-       .rename         = simple_rename,
+       .rename2        = simple_rename,
 };
 
 static const struct super_operations ramfs_ops = {

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 901e25d..2bd6754 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2950,7 +2950,8 @@ extern int simple_open(struct inode *inode, struct file *file);
 extern int simple_link(struct dentry *, struct inode *, struct dentry *);
 extern int simple_unlink(struct inode *, struct dentry *);
 extern int simple_rmdir(struct inode *, struct dentry *);
-extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
+extern int simple_rename(struct inode *, struct dentry *,
+                        struct inode *, struct dentry *, unsigned int);
 extern int noop_fsync(struct file *, loff_t, loff_t, int);
 extern int simple_empty(struct dentry *);
 extern int simple_readpage(struct file *file, struct page *page);

diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index 5967b87..c92fd89 100644 (file)
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -189,7 +189,7 @@ static const struct inode_operations bpf_dir_iops = {
        .mknod          = bpf_mkobj,
        .mkdir          = bpf_mkdir,
        .rmdir          = simple_rmdir,
-       .rename         = simple_rename,
+       .rename2        = simple_rename,
        .link           = simple_link,
        .unlink         = simple_unlink,
 };