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initramfs: support initrd that is bigger than 2GiB 

When initrd (compressed or not) is used, kernel report data corrupted with
/dev/ram0.

The root cause:
During initramfs checking, if it is initrd, it will be transferred to
/initrd.image with sys_write.
sys_write only support 2G-4K write, so if the initrd ram is more than
that, /initrd.image will not complete at all.

Add local xwrite to loop calling sys_write to workaround the problem.

Also need to use xwrite in write_buffer() to handle:
image is uncompressed cpio and there is one big file (>2G) in it.
   unpack_to_rootfs ===> write_buffer ===> actions[]/do_copy

At the same time, we don't need to worry about sys_read/sys_write in
do_mounts_rd.c::crd_load.  As decompressor will have fill/flush and local
buffer that is smaller than 2G.

Test with uncompressed initrd, and compressed ones with gz, bz2, lzma,xz,
lzop.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: "Daniel M. Weeks" <dan@danweeks.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Yinghai Lu 2014-08-08 14:23:12 -07:00 committed by Linus Torvalds
parent 4d4b866aee
commit 3874743991
1 changed files with 32 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
init/initramfs.c
View File

@ -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();
}