initramfs: add option to preserve mtime from initramfs cpio images

[safe/jmp/linux-2.6] / init / initramfs.c

diff --git a/init/initramfs.c b/init/initramfs.c
index 644fc01..4f5ba75 100644 (file)
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -6,6 +6,7 @@
 #include <linux/delay.h>
 #include <linux/string.h>
 #include <linux/syscalls.h>
+#include <linux/utime.h>
 
 static __initdata char *message;
 static void __init error(char *x)
@@ -72,6 +73,49 @@ static void __init free_hash(void)
        }
 }
 
+static long __init do_utime(char __user *filename, time_t mtime)
+{
+       struct timespec t[2];
+
+       t[0].tv_sec = mtime;
+       t[0].tv_nsec = 0;
+       t[1].tv_sec = mtime;
+       t[1].tv_nsec = 0;
+
+       return do_utimes(AT_FDCWD, filename, t, AT_SYMLINK_NOFOLLOW);
+}
+
+static __initdata LIST_HEAD(dir_list);
+struct dir_entry {
+       struct list_head list;
+       char *name;
+       time_t mtime;
+};
+
+static void __init dir_add(const char *name, time_t mtime)
+{
+       struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL);
+       if (!de)
+               panic("can't allocate dir_entry buffer");
+       INIT_LIST_HEAD(&de->list);
+       de->name = kstrdup(name, GFP_KERNEL);
+       de->mtime = mtime;
+       list_add(&de->list, &dir_list);
+}
+
+static void __init dir_utime(void)
+{
+       struct dir_entry *de, *tmp;
+       list_for_each_entry_safe(de, tmp, &dir_list, list) {
+               list_del(&de->list);
+               do_utime(de->name, de->mtime);
+               kfree(de->name);
+               kfree(de);
+       }
+}
+
+static __initdata time_t mtime;
+
 /* cpio header parsing */
 
 static __initdata unsigned long ino, major, minor, nlink;
@@ -97,6 +141,7 @@ static void __init parse_header(char *s)
        uid = parsed[2];
        gid = parsed[3];
        nlink = parsed[4];
+       mtime = parsed[5];
        body_len = parsed[6];
        major = parsed[7];
        minor = parsed[8];
@@ -130,6 +175,7 @@ static inline void __init eat(unsigned n)
        count -= n;
 }
 
+static __initdata char *vcollected;
 static __initdata char *collected;
 static __initdata int remains;
 static __initdata char *collect;
@@ -271,6 +317,7 @@ static int __init do_name(void)
                        if (wfd >= 0) {
                                sys_fchown(wfd, uid, gid);
                                sys_fchmod(wfd, mode);
+                               vcollected = kstrdup(collected, GFP_KERNEL);
                                state = CopyFile;
                        }
                }
@@ -278,12 +325,14 @@ static int __init do_name(void)
                sys_mkdir(collected, mode);
                sys_chown(collected, uid, gid);
                sys_chmod(collected, mode);
+               dir_add(collected, mtime);
        } else if (S_ISBLK(mode) || S_ISCHR(mode) ||
                   S_ISFIFO(mode) || S_ISSOCK(mode)) {
                if (maybe_link() == 0) {
                        sys_mknod(collected, mode, rdev);
                        sys_chown(collected, uid, gid);
                        sys_chmod(collected, mode);
+                       do_utime(collected, mtime);
                }
        }
        return 0;
@@ -294,6 +343,8 @@ static int __init do_copy(void)
        if (count >= body_len) {
                sys_write(wfd, victim, body_len);
                sys_close(wfd);
+               do_utime(vcollected, mtime);
+               kfree(vcollected);
                eat(body_len);
                state = SkipIt;
                return 0;
@@ -311,6 +362,7 @@ static int __init do_symlink(void)
        clean_path(collected, 0);
        sys_symlink(collected + N_ALIGN(name_len), collected);
        sys_lchown(collected, uid, gid);
+       do_utime(collected, mtime);
        state = SkipIt;
        next_state = Reset;
        return 0;
@@ -466,6 +518,7 @@ static char * __init unpack_to_rootfs(char *buf, unsigned len, int check_only)
                buf += inptr;
                len -= inptr;
        }
+       dir_utime();
        kfree(window);
        kfree(name_buf);
        kfree(symlink_buf);