bb813f4c93
This patch adds default module loading and uses it to load the default
block elevator. During boot, it's called right after initramfs or
initrd is made available and right before control is passed to
userland. This ensures that as long as the modules are available in
the usual places in initramfs, initrd or the root filesystem, the
default modules are loaded as soon as possible.
This will replace the on-demand elevator module loading from elevator
init path.
v2: Fixed build breakage when !CONFIG_BLOCK. Reported by kbuild test
robot.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alex Riesen <raa.lkml@gmail.com>
Cc: Fengguang We <fengguang.wu@intel.com>
130 lines
3.2 KiB
C
130 lines
3.2 KiB
C
/*
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* Many of the syscalls used in this file expect some of the arguments
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* to be __user pointers not __kernel pointers. To limit the sparse
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* noise, turn off sparse checking for this file.
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*/
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#ifdef __CHECKER__
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#undef __CHECKER__
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#warning "Sparse checking disabled for this file"
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#endif
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#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/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 <linux/kmod.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 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_linuxrc(struct subprocess_info *info, struct cred *new)
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{
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sys_unshare(CLONE_FS | CLONE_FILES);
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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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sys_setsid();
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return 0;
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}
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static void __init handle_initrd(void)
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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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int error;
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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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sys_chdir("/old");
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/* try loading default modules from initrd */
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load_default_modules();
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/*
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* In case that a resume from disk is carried out by linuxrc or one of
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* its children, we need to tell the freezer not to wait for us.
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*/
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current->flags |= PF_FREEZER_SKIP;
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call_usermodehelper_fns("/linuxrc", argv, envp_init, UMH_WAIT_PROC,
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init_linuxrc, NULL, NULL);
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current->flags &= ~PF_FREEZER_SKIP;
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/* move initrd to rootfs' /old */
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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_chroot("..");
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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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sys_chdir("/");
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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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