[PATCH 17/23] initramfs: switch initramfs unpacking to struct file based APIs

Christoph Hellwig
2020-07-14T19:10:13Z

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>
---
init/initramfs.c | 42 +++++++++++++++++++++---------------------
1 file changed, 21 insertions(+), 21 deletions(-)

diff --git a/init/initramfs.c b/init/initramfs.c
index d42ec8329cd840..c335920e5ecc2d 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -13,13 +13,13 @@
#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)
{
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, &file->f_pos);

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

-static __initdata int wfd;
+static __initdata struct file *wfile;

static int __init do_name(void)
{
@@ -334,16 +334,16 @@ static int __init do_name(void)
int openflags = O_WRONLY|O_CREAT;
if (ml != 1)
openflags |= O_TRUNC;
- wfd = ksys_open(collected, openflags, mode);
-
- 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;
- }
+ wfile = filp_open(collected, openflags, mode);
+ if (IS_ERR(wfile))
+ return 0;
+
+ 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);
@@ -365,16 +365,16 @@ 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) != 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) != byte_count)
error("write error");
body_len -= byte_count;
eat(byte_count);
@@ -586,21 +586,21 @@ static void __init clean_rootfs(void)
static void __init populate_initrd_image(char *err)
{
ssize_t written;
- int fd;
+ struct file *file;

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);
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 */

--
2.27.0