initramfs: support initrd that is bigger than 2GiB (38747439) · Commits · 戴 / test

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>

init/initramfs.c

+32 −4

Original line number	Diff line number	Diff line
		@@ -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,
		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();
		}

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