Messages in this thread | | | Subject | Re: [PATCH] initramfs: clean old path before creating a hardlink | From | Li Zhijian <> | Date | Thu, 22 Nov 2018 09:55:22 +0800 |
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ping
This patch is to fix initrd cannot be extracted properly in some cases.
Thanks
On 11/16/2018 03:12 PM, Li Zhijian wrote: > 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.li@intel.com> > Signed-off-by: Li Zhijian <lizhijian@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; > }
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