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nbd/server: Favor [u]int64_t over off_t

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Although our compile-time environment is set up so that we always
support long files with 64-bit off_t, we have no guarantee whether
off_t is the same type as int64_t.  This requires casts when
printing values, and prevents us from directly using qemu_strtoi64()
(which will be done in the next patch). Let's just flip to uint64_t
where possible, and stick to int64_t for detecting failure of
blk_getlength(); we also keep the assertions added in the previous
patch that the resulting values fit in 63 bits.  The overflow check
in nbd_co_receive_request() was already sane (request->from is
validated to fit in 63 bits, and request->len is 32 bits, so the
addition can't overflow 64 bits), but rewrite it in a form easier
to recognize as a typical overflow check.

Rename the variable 'description' to keep line lengths reasonable.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190117193658.16413-7-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
This commit is contained in:
Eric Blake 2019-01-17 13:36:43 -06:00
parent 7596bbb390
commit 9d26dfcbab
3 changed files with 22 additions and 29 deletions
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29
qemu-nbd.c
View file

@ -176,7 +176,7 @@ static void read_partition(uint8_t *p, struct partition_record *r)
}
static int find_partition(BlockBackend *blk, int partition,
off_t *offset, off_t *size)
uint64_t *offset, uint64_t *size)
{
struct partition_record mbr[4];
uint8_t data[MBR_SIZE];
@ -500,14 +500,14 @@ int main(int argc, char **argv)
{
BlockBackend *blk;
BlockDriverState *bs;
off_t dev_offset = 0;
uint64_t dev_offset = 0;
uint16_t nbdflags = 0;
bool disconnect = false;
const char *bindto = NULL;
const char *port = NULL;
char *sockpath = NULL;
char *device = NULL;
off_t fd_size;
int64_t fd_size;
QemuOpts *sn_opts = NULL;
const char *sn_id_or_name = NULL;
const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:";
@ -665,10 +665,6 @@ int main(int argc, char **argv)
error_report("Invalid offset `%s'", optarg);
exit(EXIT_FAILURE);
}
if (dev_offset < 0) {
error_report("Offset must be positive `%s'", optarg);
exit(EXIT_FAILURE);
}
break;
case 'l':
if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
@ -1005,15 +1001,14 @@ int main(int argc, char **argv)
}
if (dev_offset >= fd_size) {
error_report("Offset (%lld) has to be smaller than the image size "
"(%lld)",
(long long int)dev_offset, (long long int)fd_size);
error_report("Offset (%" PRIu64 ") has to be smaller than the image "
"size (%" PRId64 ")", dev_offset, fd_size);
exit(EXIT_FAILURE);
}
fd_size -= dev_offset;
if (partition != -1) {
off_t limit;
uint64_t limit;
if (dev_offset) {
error_report("Cannot request partition and offset together");
@ -1027,15 +1022,13 @@ int main(int argc, char **argv)
}
/*
* MBR partition limits are (32-bit << 9); this assert lets
* the compiler know that we have two positive values that
* can't overflow 64 bits.
* the compiler know that we can't overflow 64 bits.
*/
assert(dev_offset >= 0 && dev_offset + limit >= dev_offset);
assert(dev_offset + limit >= dev_offset);
if (dev_offset + limit > fd_size) {
error_report("Discovered partition %d at offset %lld size %lld, "
"but size exceeds file length %lld", partition,
(long long int) dev_offset, (long long int) limit,
(long long int) fd_size);
error_report("Discovered partition %d at offset %" PRIu64
" size %" PRIu64 ", but size exceeds file length %"
PRId64, partition, dev_offset, limit, fd_size);
exit(EXIT_FAILURE);
}
fd_size = limit;