Previously, sys_link() will fail due to the new path is already existed.
this case ofen appears when we use a concated initrd, below is an
sample:
1) prepare a basic rootfs, it contains a regular files rc.local
lizhijian@:~/yocto-tiny-i386-2016-04-22$ cat etc/rc.local
#!/bin/sh
echo "Running /etc/rc.local..."
yocto-tiny-i386-2016-04-22$ find . | sed 's,^\./,,' | cpio -o -H newc | gzip -n
-9 >../rootfs.cgz
2) create a extra initrd which also includes a etc/rc.local
lizhijian@:~/lkp-x86_64/etc$ echo "append initrd" >rc.local
lizhijian@:~/lkp/lkp-x86_64/etc$ cat rc.local
append initrd
lizhijian@:~/lkp/lkp-x86_64/etc$ ln rc.local rc.local.hardlink
append initrd
lizhijian@:~/lkp/lkp-x86_64/etc$ stat rc.local rc.local.hardlink
File: 'rc.local'
Size: 14 Blocks: 8 IO Block: 4096 regular file
Device: 801h/2049d Inode: 11296086 Links: 2
Access: (0664/-rw-rw-r--) Uid: ( 1002/lizhijian) Gid: ( 1002/lizhijian)
Access: 2018-11-15 16:08:28.654464815 +0800
Modify: 2018-11-15 16:07:57.514903210 +0800
Change: 2018-11-15 16:08:24.180228872 +0800
Birth: -
File: 'rc.local.hardlink'
Size: 14 Blocks: 8 IO Block: 4096 regular file
Device: 801h/2049d Inode: 11296086 Links: 2
Access: (0664/-rw-rw-r--) Uid: ( 1002/lizhijian) Gid: ( 1002/lizhijian)
Access: 2018-11-15 16:08:28.654464815 +0800
Modify: 2018-11-15 16:07:57.514903210 +0800
Change: 2018-11-15 16:08:24.180228872 +0800
Birth: -
lizhijian@:~/lkp/lkp-x86_64$ find . | sed 's,^\./,,' | cpio -o -H newc | gzip
-n -9 >../rc-local.cgz
lizhijian@:~/lkp/lkp-x86_64$ gzip -dc ../rc-local.cgz | cpio -t
.
etc
etc/rc.local.hardlink <<< it will be extracted first at this initrd
etc/rc.local
3) concate 2 initrds and boot
lizhijian@:~/lkp$ cat rootfs.cgz rc-local.cgz >concate-initrd.cgz
lizhijian@:~/lkp$ qemu-system-x86_64 -nographic -enable-kvm -cpu host -smp 1 -m
1024 -kernel ~/lkp/linux/arch/x86/boot/bzImage -append "console=ttyS0
earlyprint=ttyS0 ignore_loglevel" -initrd ./concate-initr.cgz -serial stdio
-nodefaults
In this case, sys_link(2) will fail and return -EEXIST, so we can only
get the rc.local at rootfs.cgz instead of rc-local.cgz
CC: Philip Li <philip...@intel.com>
Signed-off-by: Li Zhijian <lizhij...@cn.fujitsu.com>
---
init/initramfs.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/init/initramfs.c b/init/initramfs.c
index 6405577..381fd4c 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -291,12 +291,16 @@ static int __init do_reset(void)
return 1;
}
+static void __init clean_path(char *path, umode_t fmode);
+
static int __init maybe_link(void)
{
if (nlink >= 2) {
char *old = find_link(major, minor, ino, mode, collected);
- if (old)
+ if (old) {
+ clean_path(collected, 0);
return (ksys_link(old, collected) < 0) ? -1 : 1;
+ }
}
return 0;
}
--
2.7.4
