fs: add ksys_rmdir() wrapper; remove in-kernel calls to sys_rmdir()

Using this wrapper allows us to avoid the in-kernel calls to the
sys_rmdir() syscall. The ksys_ prefix denotes that this function is meant
as a drop-in replacement for the syscall. In particular, it uses the same
calling convention as sys_rmdir().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
This commit is contained in:
Dominik Brodowski 2018-03-11 11:34:48 +01:00
parent 6380161ce9
commit f459dffae1
4 changed files with 11 additions and 3 deletions

View File

@ -55,6 +55,7 @@ extern void __init chrdev_init(void);
extern int user_path_mountpoint_at(int, const char __user *, unsigned int, struct path *);
extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
const char *, unsigned int, struct path *);
long do_rmdir(int dfd, const char __user *pathname);
long do_unlinkat(int dfd, struct filename *name);
/*

View File

@ -3872,7 +3872,7 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry)
}
EXPORT_SYMBOL(vfs_rmdir);
static long do_rmdir(int dfd, const char __user *pathname)
long do_rmdir(int dfd, const char __user *pathname)
{
int error = 0;
struct filename *name;

View File

@ -965,4 +965,11 @@ static inline long ksys_unlink(const char __user *pathname)
return do_unlinkat(AT_FDCWD, getname(pathname));
}
extern long do_rmdir(int dfd, const char __user *pathname);
static inline long ksys_rmdir(const char __user *pathname)
{
return do_rmdir(AT_FDCWD, pathname);
}
#endif

View File

@ -317,7 +317,7 @@ static void __init clean_path(char *path, umode_t fmode)
if (!vfs_lstat(path, &st) && (st.mode ^ fmode) & S_IFMT) {
if (S_ISDIR(st.mode))
sys_rmdir(path);
ksys_rmdir(path);
else
ksys_unlink(path);
}
@ -589,7 +589,7 @@ static void __init clean_rootfs(void)
WARN_ON_ONCE(ret);
if (!ret) {
if (S_ISDIR(st.mode))
sys_rmdir(dirp->d_name);
ksys_rmdir(dirp->d_name);
else
ksys_unlink(dirp->d_name);
}