Commit bf6419e4 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

initramfs: switch initramfs unpacking to struct file based APIs 



There is no good reason to mess with file descriptors from in-kernel
code, switch the initramfs unpacking to struct file based write
instead.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b2a74d5f

init/initramfs.c

+26 −21
Original line number Diff line number Diff line
@@ -13,13 +13,14 @@ 
#include <linux/memblock.h>

#include <linux/namei.h>



static ssize_t __init xwrite(int fd, const char *p, size_t count)

static ssize_t __init xwrite(struct file *file, const char *p, size_t count,

		loff_t *pos)

{

	ssize_t out = 0;



	/* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */

	while (count) {

		ssize_t rv = ksys_write(fd, p, count);

		ssize_t rv = kernel_write(file, p, count, pos);



		if (rv < 0) {

			if (rv == -EINTR || rv == -EAGAIN)
@@ -317,7 +318,8 @@ static int __init maybe_link(void) 
	return 0;

}



static __initdata int wfd;

static __initdata struct file *wfile;

static __initdata loff_t wfile_pos;



static int __init do_name(void)

{
@@ -334,17 +336,18 @@ static int __init do_name(void) 
			int openflags = O_WRONLY|O_CREAT;

			if (ml != 1)

				openflags |= O_TRUNC;

			wfd = ksys_open(collected, openflags, mode);

			wfile = filp_open(collected, openflags, mode);

			if (IS_ERR(wfile))

				return 0;

			wfile_pos = 0;



			if (wfd >= 0) {

				ksys_fchown(wfd, uid, gid);

				ksys_fchmod(wfd, mode);

			vfs_fchown(wfile, uid, gid);

			vfs_fchmod(wfile, mode);

			if (body_len)

					ksys_ftruncate(wfd, body_len);

				vfs_truncate(&wfile->f_path, body_len);

			vcollected = kstrdup(collected, GFP_KERNEL);

			state = CopyFile;

		}

		}

	} else if (S_ISDIR(mode)) {

		ksys_mkdir(collected, mode);

		ksys_chown(collected, uid, gid);
@@ -365,16 +368,16 @@ static int __init do_name(void) 
static int __init do_copy(void)

{

	if (byte_count >= body_len) {

		if (xwrite(wfd, victim, body_len) != body_len)

		if (xwrite(wfile, victim, body_len, &wfile_pos) != body_len)

			error("write error");

		ksys_close(wfd);

		fput(wfile);

		do_utime(vcollected, mtime);

		kfree(vcollected);

		eat(body_len);

		state = SkipIt;

		return 0;

	} else {

		if (xwrite(wfd, victim, byte_count) != byte_count)

		if (xwrite(wfile, victim, byte_count, &wfile_pos) != byte_count)

			error("write error");

		body_len -= byte_count;

		eat(byte_count);
@@ -576,21 +579,23 @@ static inline bool kexec_free_initrd(void) 
static void __init populate_initrd_image(char *err)

{

	ssize_t written;

	int fd;

	struct file *file;

	loff_t pos = 0;



	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)

	file = filp_open("/initrd.image", O_WRONLY | O_CREAT, 0700);

	if (IS_ERR(file))

		return;



	written = xwrite(fd, (char *)initrd_start, initrd_end - initrd_start);

	written = xwrite(file, (char *)initrd_start, initrd_end - initrd_start,

			&pos);

	if (written != initrd_end - initrd_start)

		pr_err("/initrd.image: incomplete write (%zd != %ld)\n",

		       written, initrd_end - initrd_start);

	ksys_close(fd);

	fput(file);

}

#endif /* CONFIG_BLK_DEV_RAM */