Revision d26d45253b78ec0a67003eea25bd08fceaa5b78c authored by Linus Torvalds on 22 January 2013, 18:30:49 UTC, committed by Linus Torvalds on 22 January 2013, 18:30:49 UTC
Pull ftrace fix from Steven Rostedt:
 "Kprobes now uses the function tracer if it can.  That is, if a probe
  is placed on a function mcount/nop location, and the arch supports it,
  instead of adding a breakpoint, kprobes will register a function
  callback as that is much more efficient.

  The function tracer requires to update modules before they run, and
  uses the module notifier to do so.  But if something else in the
  module notifiers registers a kprobe at one of these locations, before
  ftrace can get to it, then the system could fail.

  The function tracer must be initialized early, otherwise module
  notifiers that probe will only work by chance."

* tag 'trace-3.8-rc4-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Be first to run code modification on modules
2 parent s 0944c0a + c1bf08a
Raw File
do_mounts_md.c
/*
 * Many of the syscalls used in this file expect some of the arguments
 * to be __user pointers not __kernel pointers.  To limit the sparse
 * noise, turn off sparse checking for this file.
 */
#ifdef __CHECKER__
#undef __CHECKER__
#warning "Sparse checking disabled for this file"
#endif

#include <linux/delay.h>
#include <linux/raid/md_u.h>
#include <linux/raid/md_p.h>

#include "do_mounts.h"

/*
 * When md (and any require personalities) are compiled into the kernel
 * (not a module), arrays can be assembles are boot time using with AUTODETECT
 * where specially marked partitions are registered with md_autodetect_dev(),
 * and with MD_BOOT where devices to be collected are given on the boot line
 * with md=.....
 * The code for that is here.
 */

#ifdef CONFIG_MD_AUTODETECT
static int __initdata raid_noautodetect;
#else
static int __initdata raid_noautodetect=1;
#endif
static int __initdata raid_autopart;

static struct {
	int minor;
	int partitioned;
	int level;
	int chunk;
	char *device_names;
} md_setup_args[256] __initdata;

static int md_setup_ents __initdata;

/*
 * Parse the command-line parameters given our kernel, but do not
 * actually try to invoke the MD device now; that is handled by
 * md_setup_drive after the low-level disk drivers have initialised.
 *
 * 27/11/1999: Fixed to work correctly with the 2.3 kernel (which
 *             assigns the task of parsing integer arguments to the
 *             invoked program now).  Added ability to initialise all
 *             the MD devices (by specifying multiple "md=" lines)
 *             instead of just one.  -- KTK
 * 18May2000: Added support for persistent-superblock arrays:
 *             md=n,0,factor,fault,device-list   uses RAID0 for device n
 *             md=n,-1,factor,fault,device-list  uses LINEAR for device n
 *             md=n,device-list      reads a RAID superblock from the devices
 *             elements in device-list are read by name_to_kdev_t so can be
 *             a hex number or something like /dev/hda1 /dev/sdb
 * 2001-06-03: Dave Cinege <dcinege@psychosis.com>
 *		Shifted name_to_kdev_t() and related operations to md_set_drive()
 *		for later execution. Rewrote section to make devfs compatible.
 */
static int __init md_setup(char *str)
{
	int minor, level, factor, fault, partitioned = 0;
	char *pername = "";
	char *str1;
	int ent;

	if (*str == 'd') {
		partitioned = 1;
		str++;
	}
	if (get_option(&str, &minor) != 2) {	/* MD Number */
		printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
		return 0;
	}
	str1 = str;
	for (ent=0 ; ent< md_setup_ents ; ent++)
		if (md_setup_args[ent].minor == minor &&
		    md_setup_args[ent].partitioned == partitioned) {
			printk(KERN_WARNING "md: md=%s%d, Specified more than once. "
			       "Replacing previous definition.\n", partitioned?"d":"", minor);
			break;
		}
	if (ent >= ARRAY_SIZE(md_setup_args)) {
		printk(KERN_WARNING "md: md=%s%d - too many md initialisations\n", partitioned?"d":"", minor);
		return 0;
	}
	if (ent >= md_setup_ents)
		md_setup_ents++;
	switch (get_option(&str, &level)) {	/* RAID level */
	case 2: /* could be 0 or -1.. */
		if (level == 0 || level == LEVEL_LINEAR) {
			if (get_option(&str, &factor) != 2 ||	/* Chunk Size */
					get_option(&str, &fault) != 2) {
				printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
				return 0;
			}
			md_setup_args[ent].level = level;
			md_setup_args[ent].chunk = 1 << (factor+12);
			if (level ==  LEVEL_LINEAR)
				pername = "linear";
			else
				pername = "raid0";
			break;
		}
		/* FALL THROUGH */
	case 1: /* the first device is numeric */
		str = str1;
		/* FALL THROUGH */
	case 0:
		md_setup_args[ent].level = LEVEL_NONE;
		pername="super-block";
	}

	printk(KERN_INFO "md: Will configure md%d (%s) from %s, below.\n",
		minor, pername, str);
	md_setup_args[ent].device_names = str;
	md_setup_args[ent].partitioned = partitioned;
	md_setup_args[ent].minor = minor;

	return 1;
}

static void __init md_setup_drive(void)
{
	int minor, i, ent, partitioned;
	dev_t dev;
	dev_t devices[MD_SB_DISKS+1];

	for (ent = 0; ent < md_setup_ents ; ent++) {
		int fd;
		int err = 0;
		char *devname;
		mdu_disk_info_t dinfo;
		char name[16];

		minor = md_setup_args[ent].minor;
		partitioned = md_setup_args[ent].partitioned;
		devname = md_setup_args[ent].device_names;

		sprintf(name, "/dev/md%s%d", partitioned?"_d":"", minor);
		if (partitioned)
			dev = MKDEV(mdp_major, minor << MdpMinorShift);
		else
			dev = MKDEV(MD_MAJOR, minor);
		create_dev(name, dev);
		for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) {
			char *p;
			char comp_name[64];
			u32 rdev;

			p = strchr(devname, ',');
			if (p)
				*p++ = 0;

			dev = name_to_dev_t(devname);
			if (strncmp(devname, "/dev/", 5) == 0)
				devname += 5;
			snprintf(comp_name, 63, "/dev/%s", devname);
			rdev = bstat(comp_name);
			if (rdev)
				dev = new_decode_dev(rdev);
			if (!dev) {
				printk(KERN_WARNING "md: Unknown device name: %s\n", devname);
				break;
			}

			devices[i] = dev;

			devname = p;
		}
		devices[i] = 0;

		if (!i)
			continue;

		printk(KERN_INFO "md: Loading md%s%d: %s\n",
			partitioned ? "_d" : "", minor,
			md_setup_args[ent].device_names);

		fd = sys_open(name, 0, 0);
		if (fd < 0) {
			printk(KERN_ERR "md: open failed - cannot start "
					"array %s\n", name);
			continue;
		}
		if (sys_ioctl(fd, SET_ARRAY_INFO, 0) == -EBUSY) {
			printk(KERN_WARNING
			       "md: Ignoring md=%d, already autodetected. (Use raid=noautodetect)\n",
			       minor);
			sys_close(fd);
			continue;
		}

		if (md_setup_args[ent].level != LEVEL_NONE) {
			/* non-persistent */
			mdu_array_info_t ainfo;
			ainfo.level = md_setup_args[ent].level;
			ainfo.size = 0;
			ainfo.nr_disks =0;
			ainfo.raid_disks =0;
			while (devices[ainfo.raid_disks])
				ainfo.raid_disks++;
			ainfo.md_minor =minor;
			ainfo.not_persistent = 1;

			ainfo.state = (1 << MD_SB_CLEAN);
			ainfo.layout = 0;
			ainfo.chunk_size = md_setup_args[ent].chunk;
			err = sys_ioctl(fd, SET_ARRAY_INFO, (long)&ainfo);
			for (i = 0; !err && i <= MD_SB_DISKS; i++) {
				dev = devices[i];
				if (!dev)
					break;
				dinfo.number = i;
				dinfo.raid_disk = i;
				dinfo.state = (1<<MD_DISK_ACTIVE)|(1<<MD_DISK_SYNC);
				dinfo.major = MAJOR(dev);
				dinfo.minor = MINOR(dev);
				err = sys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo);
			}
		} else {
			/* persistent */
			for (i = 0; i <= MD_SB_DISKS; i++) {
				dev = devices[i];
				if (!dev)
					break;
				dinfo.major = MAJOR(dev);
				dinfo.minor = MINOR(dev);
				sys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo);
			}
		}
		if (!err)
			err = sys_ioctl(fd, RUN_ARRAY, 0);
		if (err)
			printk(KERN_WARNING "md: starting md%d failed\n", minor);
		else {
			/* reread the partition table.
			 * I (neilb) and not sure why this is needed, but I cannot
			 * boot a kernel with devfs compiled in from partitioned md
			 * array without it
			 */
			sys_close(fd);
			fd = sys_open(name, 0, 0);
			sys_ioctl(fd, BLKRRPART, 0);
		}
		sys_close(fd);
	}
}

static int __init raid_setup(char *str)
{
	int len, pos;

	len = strlen(str) + 1;
	pos = 0;

	while (pos < len) {
		char *comma = strchr(str+pos, ',');
		int wlen;
		if (comma)
			wlen = (comma-str)-pos;
		else	wlen = (len-1)-pos;

		if (!strncmp(str, "noautodetect", wlen))
			raid_noautodetect = 1;
		if (!strncmp(str, "autodetect", wlen))
			raid_noautodetect = 0;
		if (strncmp(str, "partitionable", wlen)==0)
			raid_autopart = 1;
		if (strncmp(str, "part", wlen)==0)
			raid_autopart = 1;
		pos += wlen+1;
	}
	return 1;
}

__setup("raid=", raid_setup);
__setup("md=", md_setup);

static void __init autodetect_raid(void)
{
	int fd;

	/*
	 * Since we don't want to detect and use half a raid array, we need to
	 * wait for the known devices to complete their probing
	 */
	printk(KERN_INFO "md: Waiting for all devices to be available before autodetect\n");
	printk(KERN_INFO "md: If you don't use raid, use raid=noautodetect\n");

	wait_for_device_probe();

	fd = sys_open("/dev/md0", 0, 0);
	if (fd >= 0) {
		sys_ioctl(fd, RAID_AUTORUN, raid_autopart);
		sys_close(fd);
	}
}

void __init md_run_setup(void)
{
	create_dev("/dev/md0", MKDEV(MD_MAJOR, 0));

	if (raid_noautodetect)
		printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n");
	else
		autodetect_raid();
	md_setup_drive();
}
back to top