Add a simple helper to stat/lstat with a kernel space file name and
switch the early init code over to it.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 drivers/md/md-autodetect.c |  2 +-
 fs/stat.c                  | 32 ++++++++++++++++++++++----------
 include/linux/fs.h         |  1 +
 init/initramfs.c           |  3 ++-
 4 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/drivers/md/md-autodetect.c b/drivers/md/md-autodetect.c
index 14b6e86814c061..5bd52ec05ed821 100644
--- a/drivers/md/md-autodetect.c
+++ b/drivers/md/md-autodetect.c
@@ -151,7 +151,7 @@ static void __init md_setup_drive(struct md_setup_args 
*args)
                if (strncmp(devname, "/dev/", 5) == 0)
                        devname += 5;
                snprintf(comp_name, 63, "/dev/%s", devname);
-               if (vfs_stat(comp_name, &stat) == 0 && S_ISBLK(stat.mode))
+               if (kern_stat(comp_name, &stat, 0) == 0 && S_ISBLK(stat.mode))
                        dev = new_decode_dev(stat.rdev);
                if (!dev) {
                        pr_warn("md: Unknown device name: %s\n", devname);
diff --git a/fs/stat.c b/fs/stat.c
index dacecdda2e7967..3c976b92db00ca 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -151,7 +151,7 @@ int vfs_fstat(int fd, struct kstat *stat)
 /**
  * vfs_statx - Get basic and extra attributes by filename
  * @dfd: A file descriptor representing the base dir for a relative filename
- * @filename: The name of the file of interest
+ * @name: The name of the file of interest
  * @flags: Flags to control the query
  * @stat: The result structure to fill in.
  * @request_mask: STATX_xxx flags indicating what the caller wants
@@ -163,16 +163,16 @@ int vfs_fstat(int fd, struct kstat *stat)
  *
  * 0 will be returned on success, and a -ve error code if unsuccessful.
  */
-static int vfs_statx(int dfd, const char __user *filename, int flags,
+static int vfs_statx(int dfd, struct filename *name, int flags,
              struct kstat *stat, u32 request_mask)
 {
        struct path path;
        unsigned lookup_flags = 0;
-       int error;
+       int error = -EINVAL;
 
        if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
                      AT_STATX_SYNC_TYPE))
-               return -EINVAL;
+               goto out_putname;
 
        if (!(flags & AT_SYMLINK_NOFOLLOW))
                lookup_flags |= LOOKUP_FOLLOW;
@@ -182,9 +182,9 @@ static int vfs_statx(int dfd, const char __user *filename, 
int flags,
                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)
-               goto out;
+               return error;
 
        error = vfs_getattr(&path, stat, request_mask, flags);
        stat->mnt_id = real_mount(path.mnt)->mnt_id;
@@ -197,15 +197,25 @@ static int vfs_statx(int dfd, const char __user 
*filename, int flags,
                lookup_flags |= LOOKUP_REVAL;
                goto retry;
        }
-out:
+out_putname:
+       if (!IS_ERR(name))
+               putname(name);
        return error;
 }
 
+int __init kern_stat(const char *filename, struct kstat *stat, int flags)
+{
+       return vfs_statx(AT_FDCWD, getname_kernel(filename),
+                        flags | AT_NO_AUTOMOUNT, stat, STATX_BASIC_STATS);
+}
+
 int vfs_fstatat(int dfd, const char __user *filename,
                              struct kstat *stat, int flags)
 {
-       return vfs_statx(dfd, filename, flags | AT_NO_AUTOMOUNT,
-                        stat, STATX_BASIC_STATS);
+       int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
+
+       return vfs_statx(dfd, getname_flags(filename, lookup_flags, NULL),
+                        flags | AT_NO_AUTOMOUNT, stat, STATX_BASIC_STATS);
 }
 
 #ifdef __ARCH_WANT_OLD_STAT
@@ -569,6 +579,7 @@ cp_statx(const struct kstat *stat, struct statx __user 
*buffer)
 int do_statx(int dfd, const char __user *filename, unsigned flags,
             unsigned int mask, struct statx __user *buffer)
 {
+       int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
        struct kstat stat;
        int error;
 
@@ -577,7 +588,8 @@ int do_statx(int dfd, const char __user *filename, unsigned 
flags,
        if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
                return -EINVAL;
 
-       error = vfs_statx(dfd, filename, flags, &stat, mask);
+       error = vfs_statx(dfd, getname_flags(filename, lookup_flags, NULL),
+                         flags, &stat, mask);
        if (error)
                return error;
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0e0cd6a988bb38..d1f8edb39cf969 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3671,5 +3671,6 @@ int __init kern_link(const char *oldname, const char 
*newname);
 int __init kern_symlink(const char *oldname, const char *newname);
 int kern_unlink(const char *pathname);
 int __init kern_rmdir(const char *pathname);
+int __init kern_stat(const char *filename, struct kstat *stat, int flags);
 
 #endif /* _LINUX_FS_H */
diff --git a/init/initramfs.c b/init/initramfs.c
index d72594298133a7..6c605f23900fa1 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -296,7 +296,8 @@ static void __init clean_path(char *path, umode_t fmode)
 {
        struct kstat st;
 
-       if (!vfs_lstat(path, &st) && (st.mode ^ fmode) & S_IFMT) {
+       if (kern_stat(path, &st, AT_SYMLINK_NOFOLLOW) &&
+           (st.mode ^ fmode) & S_IFMT) {
                if (S_ISDIR(st.mode))
                        kern_rmdir(path);
                else
-- 
2.27.0

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