Li Zhijian 7c0950d455 initramfs: clean old path before creating a hardlink ... sys_link() can fail due to the new path already existing. This case ofen occurs when we use a concated initrd, for example: 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 [akpm@linux-foundation.org: move code to avoid forward declaration] Link: http://lkml.kernel.org/r/1542352368-13299-1-git-send-email-lizhijian@cn.fujitsu.com Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Cc: Philip Li <philip.li@intel.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Li Zhijian <zhijianx.li@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2018-11-30 14:56:14 -08:00
..
calibrate.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
do_mounts_initrd.c	init/: remove ineffective sparse disabling	2018-08-22 10:52:49 -07:00
do_mounts_md.c	init/: remove ineffective sparse disabling	2018-08-22 10:52:49 -07:00
do_mounts_rd.c	init/: remove ineffective sparse disabling	2018-08-22 10:52:49 -07:00
do_mounts.c	init/do_mounts.c: add root=PARTLABEL=<name> support	2018-10-31 08:54:13 -07:00
do_mounts.h	fs: add do_mknodat() helper and ksys_mknod() wrapper; remove in-kernel calls to syscall	2018-04-02 20:15:56 +02:00
init_task.c	signal: Don't restart fork when signals come in.	2018-08-09 13:07:01 -05:00
initramfs.c	initramfs: clean old path before creating a hardlink	2018-11-30 14:56:14 -08:00
Kconfig	psi: make disabling/enabling easier for vendor kernels	2018-11-30 14:56:14 -08:00
main.c	memblock: stop using implicit alignment to SMP_CACHE_BYTES	2018-10-31 08:54:16 -07:00
Makefile	Construct init thread stack in the linker script rather than by union	2018-01-09 23:21:02 +00:00
noinitramfs.c	fs: add do_mknodat() helper and ksys_mknod() wrapper; remove in-kernel calls to syscall	2018-04-02 20:15:56 +02:00
version.c	kbuild: Add build salt to the kernel and modules	2018-07-18 01:18:05 +09:00