initramfs: switch initramfs unpacking to struct file based APIs

[ Upstream commit bf6419e4d5 ]

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: Christoph Hellwig <hch@lst.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Stable-dep-of: 4624b346cf ("init: open /initrd.image with O_LARGEFILE")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Christoph Hellwig 2020-07-14 08:56:19 +02:00 committed by Greg Kroah-Hartman
parent 13b2d81505
commit 32e34d96b3
1 changed files with 25 additions and 20 deletions

View File

@ -11,13 +11,14 @@
#include <linux/utime.h>
#include <linux/file.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)
@ -315,7 +316,8 @@ 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)
{
@ -332,16 +334,17 @@ 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);
if (body_len)
ksys_ftruncate(wfd, body_len);
vcollected = kstrdup(collected, GFP_KERNEL);
state = CopyFile;
}
vfs_fchown(wfile, uid, gid);
vfs_fchmod(wfile, mode);
if (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);
@ -363,16 +366,16 @@ 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);
@ -620,21 +623,23 @@ static inline void clean_rootfs(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);
}
#else
static void __init populate_initrd_image(char *err)