mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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019ad4a0a6
Commit 8314418629 (Freezer: make kernel
threads nonfreezable by default) breaks freezing when attempting to resume
from an initrd, because the init (which is freezeable) spins while waiting
for another thread to run /linuxrc, but doesn't check whether it has been
told to enter the refrigerator. The original patch replaced a call to
try_to_freeze() with a call to yield(). I believe a simple reversion is
wrong because if !CONFIG_PM_SLEEP, try_to_freeze() is a noop. It should
still yield.
Signed-off-by: Nigel Cunningham <nigel@nigel.suspend2.net>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
124 lines
3.0 KiB
C
124 lines
3.0 KiB
C
#include <linux/unistd.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/minix_fs.h>
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#include <linux/ext2_fs.h>
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#include <linux/romfs_fs.h>
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#include <linux/initrd.h>
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#include <linux/sched.h>
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#include <linux/freezer.h>
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#include "do_mounts.h"
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unsigned long initrd_start, initrd_end;
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int initrd_below_start_ok;
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unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
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static int __initdata old_fd, root_fd;
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static int __initdata mount_initrd = 1;
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static int __init no_initrd(char *str)
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{
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mount_initrd = 0;
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return 1;
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}
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__setup("noinitrd", no_initrd);
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static int __init do_linuxrc(void * shell)
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{
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static char *argv[] = { "linuxrc", NULL, };
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extern char * envp_init[];
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sys_close(old_fd);sys_close(root_fd);
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sys_close(0);sys_close(1);sys_close(2);
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sys_setsid();
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(void) sys_open("/dev/console",O_RDWR,0);
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(void) sys_dup(0);
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(void) sys_dup(0);
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return kernel_execve(shell, argv, envp_init);
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}
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static void __init handle_initrd(void)
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{
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int error;
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int pid;
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real_root_dev = new_encode_dev(ROOT_DEV);
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create_dev("/dev/root.old", Root_RAM0);
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/* mount initrd on rootfs' /root */
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mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
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sys_mkdir("/old", 0700);
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root_fd = sys_open("/", 0, 0);
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old_fd = sys_open("/old", 0, 0);
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/* move initrd over / and chdir/chroot in initrd root */
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sys_chdir("/root");
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sys_mount(".", "/", NULL, MS_MOVE, NULL);
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sys_chroot(".");
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pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
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if (pid > 0)
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while (pid != sys_wait4(-1, NULL, 0, NULL)) {
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try_to_freeze();
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yield();
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}
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/* move initrd to rootfs' /old */
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sys_fchdir(old_fd);
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sys_mount("/", ".", NULL, MS_MOVE, NULL);
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/* switch root and cwd back to / of rootfs */
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sys_fchdir(root_fd);
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sys_chroot(".");
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sys_close(old_fd);
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sys_close(root_fd);
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if (new_decode_dev(real_root_dev) == Root_RAM0) {
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sys_chdir("/old");
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return;
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}
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ROOT_DEV = new_decode_dev(real_root_dev);
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mount_root();
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printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
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error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
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if (!error)
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printk("okay\n");
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else {
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int fd = sys_open("/dev/root.old", O_RDWR, 0);
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if (error == -ENOENT)
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printk("/initrd does not exist. Ignored.\n");
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else
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printk("failed\n");
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printk(KERN_NOTICE "Unmounting old root\n");
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sys_umount("/old", MNT_DETACH);
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printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
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if (fd < 0) {
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error = fd;
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} else {
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error = sys_ioctl(fd, BLKFLSBUF, 0);
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sys_close(fd);
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}
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printk(!error ? "okay\n" : "failed\n");
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}
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}
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int __init initrd_load(void)
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{
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if (mount_initrd) {
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create_dev("/dev/ram", Root_RAM0);
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/*
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* Load the initrd data into /dev/ram0. Execute it as initrd
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* unless /dev/ram0 is supposed to be our actual root device,
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* in that case the ram disk is just set up here, and gets
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* mounted in the normal path.
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*/
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if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
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sys_unlink("/initrd.image");
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handle_initrd();
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return 1;
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}
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}
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sys_unlink("/initrd.image");
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return 0;
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}
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