initramfs: use vfs_stat/lstat directly

sys_newlstat is a system call implementation that is meant for user
space, and that copies kernel-internal data structure to the user
format, which is not needed for in-kernel users.

Further, as we rearrange the system call implementation so we can extend
it with 64-bit time_t, the prototype for sys_newlstat changes.

This changes the initramfs code to use vfs_lstat directly, to get it out
of the way of the time_t changes, and make it slightly more efficient in
the process.  Along the same lines we also replace sys_stat and
sys_stat64 with vfs_stat.

Link: http://lkml.kernel.org/r/20170314214932.4052842-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/init/do_mounts.h b/init/do_mounts.h
index 067af1d9e8b620bfac146dae57d0a0f690b33475..282d65bfd6741e51c7f341c9c4fda65a492936c6 100644 (file)
--- a/init/do_mounts.h
+++ b/init/do_mounts.h
@@ -19,29 +19,15 @@ static inline int create_dev(char *name, dev_t dev)
        return sys_mknod(name, S_IFBLK|0600, new_encode_dev(dev));
 }
 
-#if BITS_PER_LONG == 32
 static inline u32 bstat(char *name)
 {
-       struct stat64 stat;
-       if (sys_stat64(name, &stat) != 0)
+       struct kstat stat;
+       if (vfs_stat(name, &stat) != 0)
                return 0;
-       if (!S_ISBLK(stat.st_mode))
+       if (!S_ISBLK(stat.mode))
                return 0;
-       if (stat.st_rdev != (u32)stat.st_rdev)
-               return 0;
-       return stat.st_rdev;
-}
-#else
-static inline u32 bstat(char *name)
-{
-       struct stat stat;
-       if (sys_newstat(name, &stat) != 0)
-               return 0;
-       if (!S_ISBLK(stat.st_mode))
-               return 0;
-       return stat.st_rdev;
+       return stat.rdev;
 }
-#endif
 
 #ifdef CONFIG_BLK_DEV_RAM
 

diff --git a/init/initramfs.c b/init/initramfs.c
index 9d180273ee8c010fde086f9efc4a50730a47e824..8a532050043f5f804f06ddbf980e54965c9055de 100644 (file)
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -312,10 +312,10 @@ static int __init maybe_link(void)
 
 static void __init clean_path(char *path, umode_t fmode)
 {
-       struct stat st;
+       struct kstat st;
 
-       if (!sys_newlstat(path, &st) && (st.st_mode ^ fmode) & S_IFMT) {
-               if (S_ISDIR(st.st_mode))
+       if (!vfs_lstat(path, &st) && (st.mode ^ fmode) & S_IFMT) {
+               if (S_ISDIR(st.mode))
                        sys_rmdir(path);
                else
                        sys_unlink(path);
@@ -581,13 +581,13 @@ static void __init clean_rootfs(void)
        num = sys_getdents64(fd, dirp, BUF_SIZE);
        while (num > 0) {
                while (num > 0) {
-                       struct stat st;
+                       struct kstat st;
                        int ret;
 
-                       ret = sys_newlstat(dirp->d_name, &st);
+                       ret = vfs_lstat(dirp->d_name, &st);
                        WARN_ON_ONCE(ret);
                        if (!ret) {
-                               if (S_ISDIR(st.st_mode))
+                               if (S_ISDIR(st.mode))
                                        sys_rmdir(dirp->d_name);
                                else
                                        sys_unlink(dirp->d_name);