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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <inttypes.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <limits.h>
#include <errno.h>
#include "gfs_ondisk.h"
#include "gfs_tool.h"
#define do_lseek(fd, off) \
do { \
if (lseek((fd), (off), SEEK_SET) != (off)) \
die("bad seek: %s on line %d of file %s\n", \
strerror(errno),__LINE__, __FILE__); \
} while (0)
#define do_read(fd, buff, len) \
do { \
if (read((fd), (buff), (len)) != (len)) \
die("bad read: %s on line %d of file %s\n", \
strerror(errno), __LINE__, __FILE__); \
} while (0)
#define do_write(fd, buff, len) \
do { \
if (write((fd), (buff), (len)) != (len)) \
die("bad write: %s on line %d of file %s\n", \
strerror(errno), __LINE__, __FILE__); \
} while (0)
/**
* do_sb - examine/modify a unmounted FS' superblock
* @argc:
* @argv:
*
*/
void
do_sb(int argc, char **argv)
{
char *device, *field, *newval = NULL;
int fd;
unsigned char buf[GFS_BASIC_BLOCK];
char input[256];
struct gfs_sb sb;
if (optind == argc)
die("Usage: gfs_tool sb <device> <field> [newval]\n");
device = argv[optind++];
if (optind == argc)
die("Usage: gfs_tool sb <device> <field> [newval]\n");
field = argv[optind++];
if (optind < argc) {
if (strcmp(field, "all") == 0)
die("can't specify new value for \"all\"\n");
newval = argv[optind++];
}
fd = open(device, (newval) ? O_RDWR : O_RDONLY);
if (fd < 0)
die("can't open %s: %s\n", device, strerror(errno));
if (newval && !override) {
printf("You shouldn't change any of these values if the filesystem is mounted.\n");
printf("\nAre you sure? [y/n] ");
if (fgets(input, 255, stdin) == NULL || input[0] != 'y')
die("aborted\n");
printf("\n");
}
do_lseek(fd, GFS_SB_ADDR * GFS_BASIC_BLOCK);
do_read(fd, buf, GFS_BASIC_BLOCK);
gfs_sb_in(&sb, (char *)buf);
if (sb.sb_header.mh_magic != GFS_MAGIC ||
sb.sb_header.mh_type != GFS_METATYPE_SB)
die("there isn't a GFS filesystem on %s\n", device);
if (strcmp(field, "proto") == 0) {
printf("current lock protocol name = \"%s\"\n",
sb.sb_lockproto);
if (newval) {
if (strlen(newval) >= GFS_LOCKNAME_LEN)
die("new lockproto name is too long\n");
strcpy(sb.sb_lockproto, newval);
printf("new lock protocol name = \"%s\"\n",
sb.sb_lockproto);
}
} else if (strcmp(field, "table") == 0) {
printf("current lock table name = \"%s\"\n",
sb.sb_locktable);
if (newval) {
if (strlen(newval) >= GFS_LOCKNAME_LEN)
die("new locktable name is too long\n");
strcpy(sb.sb_locktable, newval);
printf("new lock table name = \"%s\"\n",
sb.sb_locktable);
}
} else if (strcmp(field, "ondisk") == 0) {
printf("current ondisk format = %u\n",
sb.sb_fs_format);
if (newval) {
sb.sb_fs_format = atoi(newval);
printf("new ondisk format = %u\n",
sb.sb_fs_format);
}
} else if (strcmp(field, "multihost") == 0) {
printf("current multihost format = %u\n",
sb.sb_multihost_format);
if (newval) {
sb.sb_multihost_format = atoi(newval);
printf("new multihost format = %u\n",
sb.sb_multihost_format);
}
} else if (strcmp(field, "all") == 0) {
gfs_sb_print(&sb);
newval = FALSE;
} else
die("unknown field %s\n", field);
if (newval) {
gfs_sb_out(&sb, (char *)buf);
do_lseek(fd, GFS_SB_ADDR * GFS_BASIC_BLOCK);
do_write(fd, buf, GFS_BASIC_BLOCK);
fsync(fd);
printf("Done\n");
}
close(fd);
}

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