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Subject[PATCH 12/24] fs: add a kern_utimes helper
Date
Add a simple helper to set timestamps with a kernel space name and use it
in the early init code instead of relying on the implicit
set_fs(KERNEL_DS) there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/utimes.c | 19 ++++++++++++++-----
include/linux/fs.h | 1 +
init/initramfs.c | 2 +-
3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/fs/utimes.c b/fs/utimes.c
index fd3cc42262241f..f4d7f9a73e115a 100644
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -7,6 +7,7 @@
#include <linux/uaccess.h>
#include <linux/compat.h>
#include <asm/unistd.h>
+#include "internal.h"

static bool nsec_valid(long nsec)
{
@@ -75,14 +76,15 @@ int vfs_utimes(const struct path *path, struct timespec64 *times)
return error;
}

-static int do_utimes_path(int dfd, const char __user *filename,
+static int do_utimes_path(int dfd, struct filename *name,
struct timespec64 *times, int flags)
{
struct path path;
int lookup_flags = 0, error;

+ error = -EINVAL;
if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH))
- return -EINVAL;
+ goto out_putname;

if (!(flags & AT_SYMLINK_NOFOLLOW))
lookup_flags |= LOOKUP_FOLLOW;
@@ -90,7 +92,7 @@ static int do_utimes_path(int dfd, const char __user *filename,
lookup_flags |= LOOKUP_EMPTY;

retry:
- error = user_path_at(dfd, filename, lookup_flags, &path);
+ error = filename_lookup(dfd, name, lookup_flags, &path, NULL);
if (error)
return error;

@@ -100,10 +102,17 @@ static int do_utimes_path(int dfd, const char __user *filename,
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
-
+out_putname:
+ if (!IS_ERR(name))
+ putname(name);
return error;
}

+int __init kern_utimes(const char *filename, struct timespec64 *tv, int flags)
+{
+ return do_utimes_path(AT_FDCWD, getname_kernel(filename), tv, flags);
+}
+
static int do_utimes_fd(int fd, struct timespec64 *times, int flags)
{
struct fd f;
@@ -140,7 +149,7 @@ long do_utimes(int dfd, const char __user *filename, struct timespec64 *times,
{
if (filename == NULL && dfd != AT_FDCWD)
return do_utimes_fd(dfd, times, flags);
- return do_utimes_path(dfd, filename, times, flags);
+ return do_utimes_path(dfd, getname(filename), times, flags);
}

SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index ca034126cb0e4d..7472ff0b7062d9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3676,5 +3676,6 @@ int kern_chroot(const char *filename);
int __init kern_access(const char *filename, int mode);
int __init kern_chown(const char *filename, uid_t user, gid_t group, int flag);
int __init kern_chmod(const char *filename, umode_t mode);
+int __init kern_utimes(const char *filename, struct timespec64 *tv, int flags);

#endif /* _LINUX_FS_H */
diff --git a/init/initramfs.c b/init/initramfs.c
index 2c2d4480d495e8..de850d4c6da200 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -110,7 +110,7 @@ static long __init do_utime(char *filename, time64_t mtime)
t[1].tv_sec = mtime;
t[1].tv_nsec = 0;

- return do_utimes(AT_FDCWD, filename, t, AT_SYMLINK_NOFOLLOW);
+ return kern_utimes(filename, t, 0);
}

static __initdata LIST_HEAD(dir_list);
--
2.27.0
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