kern_subr.c

来自「基于组件方式开发操作系统的OSKIT源代码」· C语言 代码 · 共 1,141 行 · 第 1/2 页

doexechooks(p)
	struct proc *p;
{
	struct exechook_desc *edp;

	for (edp = LIST_FIRST(&exechook_list);
	     edp != NULL;
	     edp = LIST_NEXT(edp, ehk_list)) {
		(*edp->ehk_fn)(p, edp->ehk_arg);
	}
}

/*
 * Determine the root device and, if instructed to, the root file system.
 */

#include "md.h"
#if NMD == 0
#undef MEMORY_DISK_HOOKS
#endif

#ifdef MEMORY_DISK_HOOKS
static struct device fakemdrootdev[NMD];
#endif

#include "raid.h"
#if NRAID == 1
#define BOOT_FROM_RAID_HOOKS 1
#endif

#ifdef BOOT_FROM_RAID_HOOKS
extern int numraid;
extern struct device *raidrootdev;
#endif

void
setroot(bootdv, bootpartition)
	struct device *bootdv;
	int bootpartition;
{
	struct device *dv;
	int len;
#ifdef MEMORY_DISK_HOOKS
	int i;
#endif
	dev_t nrootdev;
	dev_t ndumpdev = NODEV;
	char buf[128];
	const char *rootdevname;
	const char *dumpdevname;
	struct device *rootdv = NULL;		/* XXX gcc -Wuninitialized */
	struct device *dumpdv = NULL;
	struct ifnet *ifp;
	const char *deffsname;
	struct vfsops *vops;
	extern int (*mountroot) __P((void));

#ifdef MEMORY_DISK_HOOKS
	for (i = 0; i < NMD; i++) {
		fakemdrootdev[i].dv_class  = DV_DISK;
		fakemdrootdev[i].dv_cfdata = NULL;
		fakemdrootdev[i].dv_unit   = i;
		fakemdrootdev[i].dv_parent = NULL;
		sprintf(fakemdrootdev[i].dv_xname, "md%d", i);
	}
#endif /* MEMORY_DISK_HOOKS */

#ifdef MEMORY_DISK_IS_ROOT
	bootdv = &fakemdrootdev[0];
	bootpartition = 0;
#endif

	/*
	 * If NFS is specified as the file system, and we found
	 * a DV_DISK boot device (or no boot device at all), then
	 * find a reasonable network interface for "rootspec".
	 */
	vops = vfs_getopsbyname("nfs");
	if (vops != NULL && vops->vfs_mountroot == mountroot &&
	    rootspec == NULL &&
	    (bootdv == NULL || bootdv->dv_class != DV_IFNET)) {
		for (ifp = ifnet.tqh_first; ifp != NULL;
		    ifp = ifp->if_list.tqe_next)
			if ((ifp->if_flags &
			     (IFF_LOOPBACK|IFF_POINTOPOINT)) == 0)
				break;
		if (ifp == NULL) {
			/*
			 * Can't find a suitable interface; ask the
			 * user.
			 */
			boothowto |= RB_ASKNAME;
		} else {
			/*
			 * Have a suitable interface; behave as if
			 * the user specified this interface.
			 */
			rootspec = (const char *)ifp->if_xname;
		}
	}

	/*
	 * If wildcarded root and we the boot device wasn't determined,
	 * ask the user.
	 */
	if (rootspec == NULL && bootdv == NULL)
		boothowto |= RB_ASKNAME;

 top:
	if (boothowto & RB_ASKNAME) {
		struct device *defdumpdv;

		for (;;) {
			printf("root device");
			if (bootdv != NULL) {
				printf(" (default %s", bootdv->dv_xname);
				if (bootdv->dv_class == DV_DISK)
					printf("%c", bootpartition + 'a');
				printf(")");
			}
			printf(": ");
			len = cngetsn(buf, sizeof(buf));
			if (len == 0 && bootdv != NULL) {
				strcpy(buf, bootdv->dv_xname);
				len = strlen(buf);
			}
			if (len > 0 && buf[len - 1] == '*') {
				buf[--len] = '\0';
				dv = getdisk(buf, len, 1, &nrootdev, 0);
				if (dv != NULL) {
					rootdv = dv;
					break;
				}
			}
			dv = getdisk(buf, len, bootpartition, &nrootdev, 0);
			if (dv != NULL) {
				rootdv = dv;
				break;
			}
		}

		/*
		 * Set up the default dump device.  If root is on
		 * a network device, there is no default dump
		 * device, since we don't support dumps to the
		 * network.
		 */
		if (rootdv->dv_class == DV_IFNET)
			defdumpdv = NULL;
		else
			defdumpdv = rootdv;

		for (;;) {
			printf("dump device");
			if (defdumpdv != NULL) {
				/*
				 * Note, we know it's a disk if we get here.
				 */
				printf(" (default %sb)", defdumpdv->dv_xname);
			}
			printf(": ");
			len = cngetsn(buf, sizeof(buf));
			if (len == 0) {
				if (defdumpdv != NULL) {
					ndumpdev = MAKEDISKDEV(major(nrootdev),
					    DISKUNIT(nrootdev), 1);
				}
				dumpdv = defdumpdv;
				break;
			}
			if (len == 4 && strcmp(buf, "none") == 0) {
				dumpdv = NULL;
				break;
			}
			dv = getdisk(buf, len, 1, &ndumpdev, 1);
			if (dv != NULL) {
				dumpdv = dv;
				break;
			}
		}

		rootdev = nrootdev;
		dumpdev = ndumpdev;

		for (vops = LIST_FIRST(&vfs_list); vops != NULL;
		     vops = LIST_NEXT(vops, vfs_list)) {
			if (vops->vfs_mountroot != NULL &&
			    vops->vfs_mountroot == mountroot)
			break;
		}

		if (vops == NULL) {
			mountroot = NULL;
			deffsname = "generic";
		} else
			deffsname = vops->vfs_name;

		for (;;) {
			printf("file system (default %s): ", deffsname);
			len = cngetsn(buf, sizeof(buf));
			if (len == 0)
				break;
			if (len == 4 && strcmp(buf, "halt") == 0)
				cpu_reboot(RB_HALT, NULL);
			else if (len == 7 && strcmp(buf, "generic") == 0) {
				mountroot = NULL;
				break;
			}
			vops = vfs_getopsbyname(buf);
			if (vops == NULL || vops->vfs_mountroot == NULL) {
				printf("use one of: generic");
				for (vops = LIST_FIRST(&vfs_list);
				     vops != NULL;
				     vops = LIST_NEXT(vops, vfs_list)) {
					if (vops->vfs_mountroot != NULL)
						printf(" %s", vops->vfs_name);
				}
				printf(" halt\n");
			} else {
				mountroot = vops->vfs_mountroot;
				break;
			}
		}

	} else if (rootspec == NULL) {
		int majdev;

		/*
		 * Wildcarded root; use the boot device.
		 */
		rootdv = bootdv;

		majdev = findblkmajor(bootdv->dv_xname);
		if (majdev >= 0) {
			/*
			 * Root is on a disk.  `bootpartition' is root.
			 */
			rootdev = MAKEDISKDEV(majdev, bootdv->dv_unit,
			    bootpartition);
		}
	} else {

		/*
		 * `root on <dev> ...'
		 */

		/*
		 * If it's a network interface, we can bail out
		 * early.
		 */
		dv = finddevice(rootspec);
		if (dv != NULL && dv->dv_class == DV_IFNET) {
			rootdv = dv;
			goto haveroot;
		}

		rootdevname = findblkname(major(rootdev));
		if (rootdevname == NULL) {
			printf("unknown device major 0x%x\n", rootdev);
			boothowto |= RB_ASKNAME;
			goto top;
		}
		memset(buf, 0, sizeof(buf));
		sprintf(buf, "%s%d", rootdevname, DISKUNIT(rootdev));

		rootdv = finddevice(buf);
		if (rootdv == NULL) {
			printf("device %s (0x%x) not configured\n",
			    buf, rootdev);
			boothowto |= RB_ASKNAME;
			goto top;
		}
	}

 haveroot:

	root_device = rootdv;

	switch (rootdv->dv_class) {
	case DV_IFNET:
		printf("root on %s", rootdv->dv_xname);
		break;

	case DV_DISK:
		printf("root on %s%c", rootdv->dv_xname,
		    DISKPART(rootdev) + 'a');
		break;

	default:
		printf("can't determine root device\n");
		boothowto |= RB_ASKNAME;
		goto top;
	}

	/*
	 * Now configure the dump device.
	 *
	 * If we haven't figured out the dump device, do so, with
	 * the following rules:
	 *
	 *	(a) We already know dumpdv in the RB_ASKNAME case.
	 *
	 *	(b) If dumpspec is set, try to use it.  If the device
	 *	    is not available, punt.
	 *
	 *	(c) If dumpspec is not set, the dump device is
	 *	    wildcarded or unspecified.  If the root device
	 *	    is DV_IFNET, punt.  Otherwise, use partition b
	 *	    of the root device.
	 */

	if (boothowto & RB_ASKNAME) {		/* (a) */
		if (dumpdv == NULL)
			goto nodumpdev;
	} else if (dumpspec != NULL) {		/* (b) */
		if (strcmp(dumpspec, "none") == 0 || dumpdev == NODEV) {
			/*
			 * Operator doesn't want a dump device.
			 * Or looks like they tried to pick a network
			 * device.  Oops.
			 */
			goto nodumpdev;
		}

		dumpdevname = findblkname(major(dumpdev));
		if (dumpdevname == NULL)
			goto nodumpdev;
		memset(buf, 0, sizeof(buf));
		sprintf(buf, "%s%d", dumpdevname, DISKUNIT(dumpdev));

		dumpdv = finddevice(buf);
		if (dumpdv == NULL) {
			/*
			 * Device not configured.
			 */
			goto nodumpdev;
		}
	} else {				/* (c) */
		if (rootdv->dv_class == DV_IFNET)
			goto nodumpdev;
		else {
			dumpdv = rootdv;
			dumpdev = MAKEDISKDEV(major(rootdev),
			    dumpdv->dv_unit, 1);
		}
	}

	printf(" dumps on %s%c\n", dumpdv->dv_xname, DISKPART(dumpdev) + 'a');
	return;

 nodumpdev:
	dumpdev = NODEV;
	printf("\n");
}

static int
findblkmajor(name)
	const char *name;
{
	int i;

	for (i = 0; dev_name2blk[i].d_name != NULL; i++)
		if (strncmp(name, dev_name2blk[i].d_name,
		    strlen(dev_name2blk[i].d_name)) == 0)
			return (dev_name2blk[i].d_maj);
	return (-1);
}

const char *
findblkname(maj)
	int maj;
{
	int i;

	for (i = 0; dev_name2blk[i].d_name != NULL; i++)
		if (dev_name2blk[i].d_maj == maj)
			return (dev_name2blk[i].d_name);
	return (NULL);
}

static struct device *
finddevice(name)
	const char *name;
{
	struct device *dv;
#ifdef BOOT_FROM_RAID_HOOKS
	int j;

	for (j = 0; j < numraid; j++) {
		if (strcmp(name, raidrootdev[j].dv_xname) == 0) {
			dv = &raidrootdev[j];
			return (dv);
		}
	}
#endif

	for (dv = TAILQ_FIRST(&alldevs); dv != NULL;
	    dv = TAILQ_NEXT(dv, dv_list))
		if (strcmp(dv->dv_xname, name) == 0)
			break;
	return (dv);
}

static struct device *
getdisk(str, len, defpart, devp, isdump)
	char *str;
	int len, defpart;
	dev_t *devp;
	int isdump;
{
	struct device	*dv;
#ifdef MEMORY_DISK_HOOKS
	int		i;
#endif
#ifdef BOOT_FROM_RAID_HOOKS
	int 		j;
#endif

	if ((dv = parsedisk(str, len, defpart, devp)) == NULL) {
		printf("use one of:");
#ifdef MEMORY_DISK_HOOKS
		if (isdump == 0)
			for (i = 0; i < NMD; i++)
				printf(" %s[a-%c]", fakemdrootdev[i].dv_xname,
				    'a' + MAXPARTITIONS - 1);
#endif
#ifdef BOOT_FROM_RAID_HOOKS
		if (isdump == 0)
			for (j = 0; j < numraid; j++)
				printf(" %s[a-%c]", raidrootdev[j].dv_xname,
				    'a' + MAXPARTITIONS - 1);
#endif
		for (dv = alldevs.tqh_first; dv != NULL;
		    dv = dv->dv_list.tqe_next) {
			if (dv->dv_class == DV_DISK)
				printf(" %s[a-%c]", dv->dv_xname,
				    'a' + MAXPARTITIONS - 1);
			if (isdump == 0 && dv->dv_class == DV_IFNET)
				printf(" %s", dv->dv_xname);
		}
		if (isdump)
			printf(" none");
		printf(" halt\n");
	}
	return (dv);
}

static struct device *
parsedisk(str, len, defpart, devp)
	char *str;
	int len, defpart;
	dev_t *devp;
{
	struct device *dv;
	char *cp, c;
	int majdev, part;
#ifdef MEMORY_DISK_HOOKS
	int i;
#endif
	if (len == 0)
		return (NULL);

	if (len == 4 && strcmp(str, "halt") == 0)
		cpu_reboot(RB_HALT, NULL);

	cp = str + len - 1;
	c = *cp;
	if (c >= 'a' && c <= ('a' + MAXPARTITIONS - 1)) {
		part = c - 'a';
		*cp = '\0';
	} else
		part = defpart;

#ifdef MEMORY_DISK_HOOKS
	for (i = 0; i < NMD; i++)
		if (strcmp(str, fakemdrootdev[i].dv_xname) == 0) {
			dv = &fakemdrootdev[i];
			goto gotdisk;
		}
#endif

	dv = finddevice(str);
	if (dv != NULL) {
		if (dv->dv_class == DV_DISK) {
#ifdef MEMORY_DISK_HOOKS
 gotdisk:
#endif
			majdev = findblkmajor(dv->dv_xname);
			if (majdev < 0)
				panic("parsedisk");
			*devp = MAKEDISKDEV(majdev, dv->dv_unit, part);
		}

		if (dv->dv_class == DV_IFNET)
			*devp = NODEV;
	}

	*cp = c;
	return (dv);
}

/*
 * snprintf() `bytes' into `buf', reformatting it so that the number,
 * plus a possible `x' + suffix extension) fits into len bytes (including
 * the terminating NUL).
 * Returns the number of bytes stored in buf, or -1 if there was a problem.
 * E.g, given a len of 9 and a suffix of `B':
 *	bytes		result
 *	-----		------
 *	99999		`99999 B'
 *	100000		`97 KB'
 *	66715648	`65152 KB'
 *	252215296	`240 MB'
 */
int
humanize_number(buf, len, bytes, suffix, divisor)
	char		*buf;
	size_t		 len;
	u_int64_t	 bytes;
	const char	*suffix;
	int 		divisor;
{
		/* prefixes are: (none), Kilo, Mega, Giga, Tera, Peta, Exa */
	static const char prefixes[] = " KMGTPE";

	int		i, r;
	u_int64_t	max;
	size_t		suffixlen;

	if (buf == NULL || suffix == NULL)
		return (-1);
	if (len > 0)
		buf[0] = '\0';
	suffixlen = strlen(suffix);
			/* check if enough room for `x y' + suffix + `\0' */
	if (len < 4 + suffixlen)
		return (-1);

	max = 1;
	for (i = 0; i < len - suffixlen - 3; i++)
		max *= 10;
	for (i = 0; bytes >= max && i < sizeof(prefixes); i++)
		bytes /= divisor;

	r = snprintf(buf, len, "%qu%s%c%s", (unsigned long long)bytes,
	    i == 0 ? "" : " ", prefixes[i], suffix);

	return (r);
}

int
format_bytes(buf, len, bytes)
	char		*buf;
	size_t		 len;
	u_int64_t	 bytes;
{
	int	rv;
	size_t	nlen;

	rv = humanize_number(buf, len, bytes, "B", 1024);
	if (rv != -1) {
			/* nuke the trailing ` B' if it exists */
		nlen = strlen(buf) - 2;
		if (strcmp(&buf[nlen], " B") == 0)
			buf[nlen] = '\0';
	}
	return (rv);
}
#endif /*OSKIT*/