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freebsd-nq/sbin/mdconfig/mdconfig.c
Christian S.J. Peron c313f09bfb When using files as backing stores for devices, and the user has requested the 
device be created read+write, check to see if the backing store is read only
through the use of the access(2) system call. If this check fails returning
EACCES, EPERM or EROFS then gracefully downgrade the access to read only. Also
print a warning message to stderr, informing the user that the access mode
they requested is not available.

This behavior used to be handled by md(4) but was changed in revision 1.154

Discussed with:	pjd, phk, Dario Freni <saturnero at freesbie dot org>
Reviewed by:	phk
2005-08-30 16:45:32 +00:00

366 lines
9.2 KiB
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/*
* ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
* ----------------------------------------------------------------------------
*
* $FreeBSD$
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <inttypes.h>
#include <libutil.h>
#include <string.h>
#include <err.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/module.h>
#include <sys/linker.h>
#include <sys/mdioctl.h>
#include <sys/stat.h>
int list(const int);
void mdmaybeload(void);
int query(const int, const int);
void usage(void);
struct md_ioctl mdio;
enum {UNSET, ATTACH, DETACH, LIST} action = UNSET;
int nflag;
void
usage()
{
fprintf(stderr,
"usage: mdconfig -a -t type [-n] [-o [no]option] ... [-f file]\n"
" [-s size] [-S sectorsize] [-u unit]\n"
" [-x sectors/track] [-y heads/cyl]\n"
" mdconfig -d -u unit\n"
" mdconfig -l [-n] [-u unit]\n");
fprintf(stderr, "\t\ttype = {malloc, preload, vnode, swap}\n");
fprintf(stderr, "\t\toption = {cluster, compress, reserve}\n");
fprintf(stderr, "\t\tsize = %%d (512 byte blocks), %%db (B),\n");
fprintf(stderr, "\t\t %%dk (kB), %%dm (MB), %%dg (GB) or\n");
fprintf(stderr, "\t\t %%dt (TB)\n");
exit(1);
}
int
main(int argc, char **argv)
{
int ch, fd, i;
char *p;
int cmdline = 0;
bzero(&mdio, sizeof(mdio));
mdio.md_file = malloc(PATH_MAX);
if (mdio.md_file == NULL)
err(1, "could not allocate memory");
bzero(mdio.md_file, PATH_MAX);
for (;;) {
ch = getopt(argc, argv, "ab:df:lno:s:S:t:u:x:y:");
if (ch == -1)
break;
switch (ch) {
case 'a':
if (cmdline != 0)
usage();
action = ATTACH;
cmdline = 1;
break;
case 'd':
if (cmdline != 0)
usage();
action = DETACH;
mdio.md_options = MD_AUTOUNIT;
cmdline = 3;
break;
case 'l':
if (cmdline != 0)
usage();
action = LIST;
mdio.md_options = MD_AUTOUNIT;
cmdline = 3;
break;
case 'n':
nflag = 1;
break;
case 't':
if (cmdline != 1)
usage();
if (!strcmp(optarg, "malloc")) {
mdio.md_type = MD_MALLOC;
mdio.md_options = MD_AUTOUNIT | MD_COMPRESS;
} else if (!strcmp(optarg, "preload")) {
mdio.md_type = MD_PRELOAD;
mdio.md_options = 0;
} else if (!strcmp(optarg, "vnode")) {
mdio.md_type = MD_VNODE;
mdio.md_options = MD_CLUSTER | MD_AUTOUNIT | MD_COMPRESS;
} else if (!strcmp(optarg, "swap")) {
mdio.md_type = MD_SWAP;
mdio.md_options = MD_CLUSTER | MD_AUTOUNIT | MD_COMPRESS;
} else {
usage();
}
cmdline=2;
break;
case 'f':
if (cmdline != 1 && cmdline != 2)
usage();
if (cmdline == 1) {
/* Imply ``-t vnode'' */
mdio.md_type = MD_VNODE;
mdio.md_options = MD_CLUSTER | MD_AUTOUNIT | MD_COMPRESS;
cmdline = 2;
}
if (realpath(optarg, mdio.md_file) == NULL) {
err(1, "could not find full path for %s",
optarg);
}
fd = open(mdio.md_file, O_RDONLY);
if (fd < 0)
err(1, "could not open %s", optarg);
else if (mdio.md_mediasize == 0) {
struct stat sb;
if (fstat(fd, &sb) == -1)
err(1, "could not stat %s", optarg);
mdio.md_mediasize = sb.st_size;
}
close(fd);
break;
case 'o':
if (cmdline != 2)
usage();
if (!strcmp(optarg, "async"))
mdio.md_options |= MD_ASYNC;
else if (!strcmp(optarg, "noasync"))
mdio.md_options &= ~MD_ASYNC;
else if (!strcmp(optarg, "cluster"))
mdio.md_options |= MD_CLUSTER;
else if (!strcmp(optarg, "nocluster"))
mdio.md_options &= ~MD_CLUSTER;
else if (!strcmp(optarg, "compress"))
mdio.md_options |= MD_COMPRESS;
else if (!strcmp(optarg, "nocompress"))
mdio.md_options &= ~MD_COMPRESS;
else if (!strcmp(optarg, "force"))
mdio.md_options |= MD_FORCE;
else if (!strcmp(optarg, "noforce"))
mdio.md_options &= ~MD_FORCE;
else if (!strcmp(optarg, "readonly"))
mdio.md_options |= MD_READONLY;
else if (!strcmp(optarg, "noreadonly"))
mdio.md_options &= ~MD_READONLY;
else if (!strcmp(optarg, "reserve"))
mdio.md_options |= MD_RESERVE;
else if (!strcmp(optarg, "noreserve"))
mdio.md_options &= ~MD_RESERVE;
else
errx(1, "Unknown option: %s.", optarg);
break;
case 'S':
if (cmdline != 2)
usage();
mdio.md_sectorsize = strtoul(optarg, &p, 0);
break;
case 's':
if (cmdline != 2)
usage();
mdio.md_mediasize = (off_t)strtoumax(optarg, &p, 0);
if (p == NULL || *p == '\0')
mdio.md_mediasize *= DEV_BSIZE;
else if (*p == 'b' || *p == 'B')
; /* do nothing */
else if (*p == 'k' || *p == 'K')
mdio.md_mediasize <<= 10;
else if (*p == 'm' || *p == 'M')
mdio.md_mediasize <<= 20;
else if (*p == 'g' || *p == 'G')
mdio.md_mediasize <<= 30;
else if (*p == 't' || *p == 'T') {
mdio.md_mediasize <<= 30;
mdio.md_mediasize <<= 10;
} else
errx(1, "Unknown suffix on -s argument");
break;
case 'u':
if (cmdline != 2 && cmdline != 3)
usage();
if (!strncmp(optarg, "/dev/", 5))
optarg += 5;
if (!strncmp(optarg, MD_NAME, sizeof(MD_NAME) - 1))
optarg += sizeof(MD_NAME) - 1;
mdio.md_unit = strtoul(optarg, &p, 0);
if (mdio.md_unit == (unsigned)ULONG_MAX || *p != '\0')
errx(1, "bad unit: %s", optarg);
mdio.md_options &= ~MD_AUTOUNIT;
break;
case 'x':
if (cmdline != 2)
usage();
mdio.md_fwsectors = strtoul(optarg, &p, 0);
break;
case 'y':
if (cmdline != 2)
usage();
mdio.md_fwheads = strtoul(optarg, &p, 0);
break;
default:
usage();
}
}
mdio.md_version = MDIOVERSION;
mdmaybeload();
fd = open("/dev/" MDCTL_NAME, O_RDWR, 0);
if (fd < 0)
err(1, "open(/dev/%s)", MDCTL_NAME);
if (cmdline == 2
&& (mdio.md_type == MD_MALLOC || mdio.md_type == MD_SWAP))
if (mdio.md_mediasize == 0)
errx(1, "must specify -s for -t malloc or -t swap");
if (cmdline == 2 && mdio.md_type == MD_VNODE)
if (mdio.md_file[0] == '\0')
errx(1, "must specify -f for -t vnode");
if (mdio.md_type == MD_VNODE &&
(mdio.md_options & MD_READONLY) == 0) {
if (access(mdio.md_file, W_OK) < 0 &&
(errno == EACCES || errno == EPERM || errno == EROFS)) {
fprintf(stderr,
"WARNING: opening backing store: %s readonly\n",
mdio.md_file);
mdio.md_options |= MD_READONLY;
}
}
if (action == LIST) {
if (mdio.md_options & MD_AUTOUNIT)
list(fd);
else
query(fd, mdio.md_unit);
} else if (action == ATTACH) {
if (cmdline < 2)
usage();
i = ioctl(fd, MDIOCATTACH, &mdio);
if (i < 0)
err(1, "ioctl(/dev/%s)", MDCTL_NAME);
if (mdio.md_options & MD_AUTOUNIT)
printf("%s%d\n", nflag ? "" : MD_NAME, mdio.md_unit);
} else if (action == DETACH) {
if (mdio.md_options & MD_AUTOUNIT)
usage();
i = ioctl(fd, MDIOCDETACH, &mdio);
if (i < 0)
err(1, "ioctl(/dev/%s)", MDCTL_NAME);
} else
usage();
close (fd);
return (0);
}
int
list(const int fd)
{
int unit;
if (ioctl(fd, MDIOCLIST, &mdio) < 0)
err(1, "ioctl(/dev/%s)", MDCTL_NAME);
for (unit = 0; unit < mdio.md_pad[0] && unit < MDNPAD - 1; unit++) {
printf("%s%s%d", unit > 0 ? " " : "",
nflag ? "" : MD_NAME, mdio.md_pad[unit + 1]);
}
if (mdio.md_pad[0] - unit > 0)
printf(" ... %d more", mdio.md_pad[0] - unit);
if (unit > 0)
printf("\n");
return (0);
}
static void
prthumanval(int64_t bytes)
{
char buf[6];
humanize_number(buf, sizeof(buf) - (bytes < 0 ? 0 : 1),
bytes, "", HN_AUTOSCALE, HN_B | HN_NOSPACE | HN_DECIMAL);
(void)printf("%6s", buf);
}
int
query(const int fd, const int unit)
{
mdio.md_version = MDIOVERSION;
mdio.md_unit = unit;
if (ioctl(fd, MDIOCQUERY, &mdio) < 0)
err(1, "ioctl(/dev/%s)", MDCTL_NAME);
(void)printf("%s%d\t", MD_NAME, mdio.md_unit);
switch (mdio.md_type) {
case MD_MALLOC:
(void)printf("malloc");
break;
case MD_PRELOAD:
(void)printf("preload");
break;
case MD_SWAP:
(void)printf("swap");
break;
case MD_VNODE:
(void)printf("vnode");
break;
}
printf("\t");
prthumanval(mdio.md_mediasize);
if (mdio.md_type == MD_VNODE)
printf("\t%s", mdio.md_file);
printf("\n");
return (0);
}
void
mdmaybeload(void)
{
struct module_stat mstat;
int fileid, modid;
const char *name;
char *cp;
name = MD_MODNAME;
/* scan files in kernel */
mstat.version = sizeof(struct module_stat);
for (fileid = kldnext(0); fileid > 0; fileid = kldnext(fileid)) {
/* scan modules in file */
for (modid = kldfirstmod(fileid); modid > 0;
modid = modfnext(modid)) {
if (modstat(modid, &mstat) < 0)
continue;
/* strip bus name if present */
if ((cp = strchr(mstat.name, '/')) != NULL) {
cp++;
} else {
cp = mstat.name;
}
/* already loaded? */
if (!strcmp(name, cp))
return;
}
}
/* not present, we should try to load it */
kldload(name);
}
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