initramfs: factor out a helper to populate the initrd image

This will allow for cleaner code sharing in the caller.

Link: http://lkml.kernel.org/r/20190213174621.29297-5-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Cc: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Steven Price <steven.price@arm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 23 insertions, 17 deletions

diff --git a/init/initramfs.c b/init/initramfs.c
index 5fda9557a134..e3de626dbd98 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -597,6 +597,28 @@ static void __init clean_rootfs(void)
 }
 #endif
 
+#ifdef CONFIG_BLK_DEV_RAM
+static void populate_initrd_image(char *err)
+{
+        ssize_t written;
+        int fd;
+
+        unpack_to_rootfs(__initramfs_start, __initramfs_size);
+
+        printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n",
+                        err);
+        fd = ksys_open("/initrd.image", O_WRONLY | O_CREAT, 0700);
+        if (fd < 0)
+                return;
+
+        written = xwrite(fd, (char *)initrd_start, initrd_end - initrd_start);
+        if (written != initrd_end - initrd_start)
+                pr_err("/initrd.image: incomplete write (%zd != %ld)\n",
+                       written, initrd_end - initrd_start);
+        ksys_close(fd);
+}
+#endif /* CONFIG_BLK_DEV_RAM */
+
 static int __init populate_rootfs(void)
 {
         /* Load the built in initramfs */
@@ -606,7 +628,6 @@ static int __init populate_rootfs(void)
         /* If available load the bootloader supplied initrd */
         if (initrd_start && !IS_ENABLED(CONFIG_INITRAMFS_FORCE)) {
 #ifdef CONFIG_BLK_DEV_RAM
-                int fd;
                 printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
                 err = unpack_to_rootfs((char *)initrd_start,
                         initrd_end - initrd_start);
@@ -614,22 +635,7 @@ static int __init populate_rootfs(void)
                         goto done;
 
                 clean_rootfs();
-                unpack_to_rootfs(__initramfs_start, __initramfs_size);
-
-                printk(KERN_INFO "rootfs image is not initramfs (%s)"
-                                "; looks like an initrd\n", err);
-                fd = ksys_open("/initrd.image",
-                              O_WRONLY|O_CREAT, 0700);
-                if (fd >= 0) {
-                        ssize_t written = xwrite(fd, (char *)initrd_start,
-                                                initrd_end - initrd_start);
-
-                        if (written != initrd_end - initrd_start)
-                                pr_err("/initrd.image: incomplete write (%zd != %ld)\n",
-                                       written, initrd_end - initrd_start);
-
-                        ksys_close(fd);
-                }
+                populate_initrd_image(err);
         done:
                 /* empty statement */;
 #else