Better validation, and use O_EXCL when opening block device

This commit is contained in:
Kent Overstreet 2012-11-21 15:31:49 -08:00
parent f2a9bace37
commit 133c859a24

View File

@ -6,6 +6,7 @@
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <limits.h>
#include <linux/fs.h>
#include <stdbool.h>
#include <stdint.h>
@ -58,6 +59,30 @@ uint64_t hatoi(const char *s)
return i;
}
unsigned hatoi_validate(const char *s, const char *msg)
{
uint64_t v = hatoi(s);
if (v & (v - 1)) {
printf("%s must be a power of two\n", msg);
exit(EXIT_FAILURE);
}
v /= 512;
if (v > USHRT_MAX) {
printf("%s too large\n", msg);
exit(EXIT_FAILURE);
}
if (!v) {
printf("%s too small\n", msg);
exit(EXIT_FAILURE);
}
return v;
}
char *skip_spaces(const char *str)
{
while (isspace(*str))
@ -154,18 +179,12 @@ void write_sb(char *dev, struct cache_sb *sb)
usage();
}
if ((sb->bucket_size & (sb->bucket_size - 1)) ||
(sb->block_size & (sb->block_size - 1))) {
printf("Block and bucket sizes must be powers of two\n");
exit(EXIT_FAILURE);
}
if (sb->bucket_size < sb->block_size) {
printf("Bad bucket size %i\n", sb->bucket_size);
printf("Bucket size cannot be smaller than block size\n");
exit(EXIT_FAILURE);
}
if ((fd = open(dev, O_RDWR)) == -1) {
if ((fd = open(dev, O_RDWR|O_EXCL)) == -1) {
printf("Can't open dev %s: %s\n", dev, strerror(errno));
exit(EXIT_FAILURE);
}
@ -252,10 +271,10 @@ int main(int argc, char **argv)
sb.version = CACHE_BACKING_DEV;
break;
case 'b':
sb.bucket_size = hatoi(optarg) / 512;
sb.bucket_size = hatoi_validate(optarg, "bucket size");
break;
case 'w':
sb.block_size = hatoi(optarg) / 512;
sb.block_size = hatoi_validate(optarg, "block size");
break;
case 'U':
if (uuid_parse(optarg, sb.uuid)) {