1 files changed, 32 insertions, 4 deletions

diff --git a/init/initramfs.c b/init/initramfs.c
index a8497fab1c3d..4f276b6a167b 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -19,6 +19,29 @@
 #include <linux/syscalls.h>
 #include <linux/utime.h>
 
+static ssize_t __init xwrite(int fd, const char *p, size_t count)
+{
+        ssize_t out = 0;
+
+        /* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */
+        while (count) {
+                ssize_t rv = sys_write(fd, p, count);
+
+                if (rv < 0) {
+                        if (rv == -EINTR || rv == -EAGAIN)
+                                continue;
+                        return out ? out : rv;
+                } else if (rv == 0)
+                        break;
+
+                p += rv;
+                out += rv;
+                count -= rv;
+        }
+
+        return out;
+}
+
 static __initdata char *message;
 static void __init error(char *x)
 {
@@ -346,7 +369,7 @@ static int __init do_name(void)
 static int __init do_copy(void)
 {
         if (count >= body_len) {
-                sys_write(wfd, victim, body_len);
+                xwrite(wfd, victim, body_len);
                 sys_close(wfd);
                 do_utime(vcollected, mtime);
                 kfree(vcollected);
@@ -354,7 +377,7 @@ static int __init do_copy(void)
                 state = SkipIt;
                 return 0;
         } else {
-                sys_write(wfd, victim, count);
+                xwrite(wfd, victim, count);
                 body_len -= count;
                 eat(count);
                 return 1;
@@ -603,8 +626,13 @@ static int __init populate_rootfs(void)
                 fd = sys_open("/initrd.image",
                               O_WRONLY|O_CREAT, 0700);
                 if (fd >= 0) {
-                        sys_write(fd, (char *)initrd_start,
-                                        initrd_end - initrd_start);
+                        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);
+
                         sys_close(fd);
                         free_initrd();
                 }