Attachment #134173 for bug #194615





	  See <file:Documentation/filesystems/tmpfs.txt> for details.

config EARLYUSERSPACE_ON_TMPFS
	bool "Unpack the early userspace onto tmpfs"
	depends TMPFS
	default y
	help
	  Use this to have your early userspace placed (decompressed)
	  onto tmpfs as opposed ramfs. This will allow you to
	  restrict the size of your root-filesystem and it will also
	  be swappable.
   
	  If unsure, say Y.

config HUGETLBFS
	bool "HugeTLB file system support"
	depends X86 || IA64 || PPC64 || SPARC64 || SUPERH || X86_64 || BROKEN




#include <linux/delay.h>
#include <linux/string.h>
#include <linux/syscalls.h>
#include <asm/uaccess.h>

static __initdata char *message;
static void __init error(char *x)

	return message;
}

/* If we want the rootfs on initramfs so we mount initramfs over the
 * rootfs before we unpack it. The little dance we do by creating a
 * pivot point and moving the root to that is in fact necessary
 * because lookups of "." don't resolve mountpoints.
 */
static inline void __init overmount_rootfs(void)
   {
#ifdef CONFIG_EARLYUSERSPACE_ON_TMPFS
    int init_tmpfs(void);
    int (*initfunc)(void) = init_tmpfs;
    mm_segment_t oldfs;
    char pivot[] = "/pivot";
   
    /* Explicitly go and init the overmount fs early (long-term
     * the need for this will probably go away. */
   
    if (initfunc())
    goto err;
   
    oldfs = get_fs();
    set_fs(KERNEL_DS);
   
    if (sys_mkdir(pivot, 0700) < 0)
    goto err;
    if (sys_mount("tmpfs", pivot, "tmpfs", 0, "size=90%"))
    goto err;
   
    /* Below here errors are unlikely and icky to deal with. */
    sys_chdir(pivot);
    sys_mount(".", "/", NULL, MS_MOVE, NULL);
    sys_chdir(".");
    sys_chroot(".");
    printk(KERN_INFO "Overmounted tmpfs\n");
    goto out;
   
    err:
    printk(KERN_ERR "Overmount error\n");
   
    out:
    set_fs(oldfs);
#endif /* CONFIG_EARLYUSERSPACE_ON_TMPFS */
}

extern char __initramfs_start[], __initramfs_end[];
#ifdef CONFIG_BLK_DEV_INITRD
#include <linux/initrd.h>

			initrd_end - initrd_start, 1);
		if (!err) {
			printk(" it is\n");
#ifdef CONFIG_EARLYUSERSPACE_ON_TMPFS
                        overmount_rootfs();
#endif /* CONFIG_EARLYUSERSPACE_ON_TMPFS */
			unpack_to_rootfs((char *)initrd_start,
				initrd_end - initrd_start, 0);
			free_initrd_mem(initrd_start, initrd_end);

Lines 701-706 Link Here

(-)linux-2.6.14.orig/init/main.c (+5 lines)
701	if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {	701	if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
702	ramdisk_execute_command = NULL;	702	ramdisk_execute_command = NULL;
703	prepare_namespace();	703	prepare_namespace();
		704	#ifdef CONFIG_EARLYUSERSPACE_ON_TMPFS
		705	int init_tmpfs(void);
		706	int (*initfunc)(void) = init_tmpfs;
		707	initfunc();
		708	#endif /* CONFIG_EARLYUSERSPACE_ON_TMPFS */
704	}	709	}
705		710
706	/*	711	/*

Lines 2136-2142 Link Here

(-)linux-2.6.14.orig/mm/shmem.c (-1 / +6 lines)
2136	};	2136	};
2137	static struct vfsmount *shm_mnt;	2137	static struct vfsmount *shm_mnt;
2138		2138
2139	static int __init init_tmpfs(void)	2139	int __init init_tmpfs(void)
2140	{	2140	{
2141	int error;	2141	int error;
2142		2142
Lines 2169-2175 Link Here
2169	shm_mnt = ERR_PTR(error);	2169	shm_mnt = ERR_PTR(error);
2170	return error;	2170	return error;
2171	}	2171	}
		2172	/* Don't do this if we are calling it early explicity */
		2173	#ifndef CONFIG_EARLYUSERSPACE_ON_TMPFS
		2174	/* If CONFIG_EARLYUSERSPACE_ON_TMPFS is set then we will interpose
		2175	* ramfs so this will get called explicitly and early */
2172	module_init(init_tmpfs)	2176	module_init(init_tmpfs)
		2177	#endif /* !CONFIG_EARLYUSERSPACE_ON_TMPFS */
2173		2178
2174	/*	2179	/*
2175	* shmem_file_setup - get an unlinked file living in tmpfs	2180	* shmem_file_setup - get an unlinked file living in tmpfs

Return to bug 194615

Lines 805-810 Link Here

(-)linux-2.6.14.orig/fs/Kconfig (+12 lines)
805		805
806	See <file:Documentation/filesystems/tmpfs.txt> for details.	806	See <file:Documentation/filesystems/tmpfs.txt> for details.
807		807
		808	config EARLYUSERSPACE_ON_TMPFS
		809	bool "Unpack the early userspace onto tmpfs"
		810	depends TMPFS
		811	default y
		812	help
		813	Use this to have your early userspace placed (decompressed)
		814	onto tmpfs as opposed ramfs. This will allow you to
		815	restrict the size of your root-filesystem and it will also
		816	be swappable.
		817
		818	If unsure, say Y.
		819
808	config HUGETLBFS	820	config HUGETLBFS
809	bool "HugeTLB file system support"	821	bool "HugeTLB file system support"
810	depends X86 \|\| IA64 \|\| PPC64 \|\| SPARC64 \|\| SUPERH \|\| X86_64 \|\| BROKEN	822	depends X86 \|\| IA64 \|\| PPC64 \|\| SPARC64 \|\| SUPERH \|\| X86_64 \|\| BROKEN

Lines 6-11 Link Here

(-)linux-2.6.14.orig/init/initramfs.c (+47 lines)
6	#include <linux/delay.h>	6	#include <linux/delay.h>
7	#include <linux/string.h>	7	#include <linux/string.h>
8	#include <linux/syscalls.h>	8	#include <linux/syscalls.h>
		9	#include <asm/uaccess.h>
9		10
10	static __initdata char *message;	11	static __initdata char *message;
11	static void __init error(char *x)	12	static void __init error(char *x)
Lines 463-468 Link Here
463	return message;	464	return message;
464	}	465	}
465		466
		467	/* If we want the rootfs on initramfs so we mount initramfs over the
		468	* rootfs before we unpack it. The little dance we do by creating a
		469	* pivot point and moving the root to that is in fact necessary
		470	* because lookups of "." don't resolve mountpoints.
		471	*/
		472	static inline void __init overmount_rootfs(void)
		473	{
		474	#ifdef CONFIG_EARLYUSERSPACE_ON_TMPFS
		475	int init_tmpfs(void);
		476	int (*initfunc)(void) = init_tmpfs;
		477	mm_segment_t oldfs;
		478	char pivot[] = "/pivot";
		479
		480	/* Explicitly go and init the overmount fs early (long-term
		481	* the need for this will probably go away. */
		482
		483	if (initfunc())
		484	goto err;
		485
		486	oldfs = get_fs();
		487	set_fs(KERNEL_DS);
		488
		489	if (sys_mkdir(pivot, 0700) < 0)
		490	goto err;
		491	if (sys_mount("tmpfs", pivot, "tmpfs", 0, "size=90%"))
		492	goto err;
		493
		494	/* Below here errors are unlikely and icky to deal with. */
		495	sys_chdir(pivot);
		496	sys_mount(".", "/", NULL, MS_MOVE, NULL);
		497	sys_chdir(".");
		498	sys_chroot(".");
		499	printk(KERN_INFO "Overmounted tmpfs\n");
		500	goto out;
		501
		502	err:
		503	printk(KERN_ERR "Overmount error\n");
		504
		505	out:
		506	set_fs(oldfs);
		507	#endif /* CONFIG_EARLYUSERSPACE_ON_TMPFS */
		508	}
		509
466	extern char __initramfs_start[], __initramfs_end[];	510	extern char __initramfs_start[], __initramfs_end[];
467	#ifdef CONFIG_BLK_DEV_INITRD	511	#ifdef CONFIG_BLK_DEV_INITRD
468	#include <linux/initrd.h>	512	#include <linux/initrd.h>
Lines 482-487 Link Here
482	initrd_end - initrd_start, 1);	526	initrd_end - initrd_start, 1);
483	if (!err) {	527	if (!err) {
484	printk(" it is\n");	528	printk(" it is\n");
		529	#ifdef CONFIG_EARLYUSERSPACE_ON_TMPFS
		530	overmount_rootfs();
		531	#endif /* CONFIG_EARLYUSERSPACE_ON_TMPFS */
485	unpack_to_rootfs((char *)initrd_start,	532	unpack_to_rootfs((char *)initrd_start,
486	initrd_end - initrd_start, 0);	533	initrd_end - initrd_start, 0);
487	free_initrd_mem(initrd_start, initrd_end);	534	free_initrd_mem(initrd_start, initrd_end);