forked from luck/tmp_suning_uos_patched
899ac10cc0
BLKFLSBUF used to be overloaded for the ramdisk driver to free the whole
ramdisk, which was completely different behavior compared to all other
drivers. But this magic overload got removed in commit ff26956875
("brd: remove support for BLKFLSBUF"), so this call is entirely
pointless now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
146 lines
3.5 KiB
C
146 lines
3.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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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 <uapi/linux/mount.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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phys_addr_t phys_initrd_start __initdata;
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unsigned long phys_initrd_size __initdata;
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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 early_initrdmem(char *p)
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{
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phys_addr_t start;
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unsigned long size;
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char *endp;
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start = memparse(p, &endp);
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if (*endp == ',') {
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size = memparse(endp + 1, NULL);
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phys_initrd_start = start;
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phys_initrd_size = size;
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}
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return 0;
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}
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early_param("initrdmem", early_initrdmem);
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/*
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* This is here as the initrd keyword has been in use since 11/2018
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* on ARM, PowerPC, and MIPS.
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* It should not be; it is reserved for bootloaders.
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*/
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static int __init early_initrd(char *p)
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{
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return early_initrdmem(p);
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}
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early_param("initrd", early_initrd);
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static int init_linuxrc(struct subprocess_info *info, struct cred *new)
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{
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ksys_unshare(CLONE_FS | CLONE_FILES);
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console_on_rootfs();
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/* move initrd over / and chdir/chroot in initrd root */
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ksys_chdir("/root");
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do_mount(".", "/", NULL, MS_MOVE, NULL);
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ksys_chroot(".");
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ksys_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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struct subprocess_info *info;
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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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ksys_mkdir("/old", 0700);
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ksys_chdir("/old");
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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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info = call_usermodehelper_setup("/linuxrc", argv, envp_init,
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GFP_KERNEL, init_linuxrc, NULL, NULL);
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if (!info)
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return;
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call_usermodehelper_exec(info, UMH_WAIT_PROC);
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current->flags &= ~PF_FREEZER_SKIP;
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/* move initrd to rootfs' /old */
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do_mount("..", ".", NULL, MS_MOVE, NULL);
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/* switch root and cwd back to / of rootfs */
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ksys_chroot("..");
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if (new_decode_dev(real_root_dev) == Root_RAM0) {
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ksys_chdir("/old");
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return;
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}
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ksys_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 = do_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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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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ksys_umount("/old", MNT_DETACH);
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}
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}
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bool __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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ksys_unlink("/initrd.image");
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handle_initrd();
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return true;
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}
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}
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ksys_unlink("/initrd.image");
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return false;
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}
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