lesderid
/
buse
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Fixed a bug in buse.c where I was mistakenly relying on read and write syscalls 

to complete an entire request in one call.
This commit is contained in:
Adam Cozzette 2011-11-17 11:17:53 -08:00
parent 28eb460f25
commit b6722defc5
1 changed files with 40 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
buse.c
View File

@ -32,12 +32,42 @@ u_int64_t ntohll(u_int64_t a) {
#endif
#define htonll ntohll
static int read_all(int fd, void *buf, size_t count)
{
int bytes_read;
while (count > 0) {
bytes_read = read(fd, buf, count);
assert(bytes_read > 0);
buf = (char *)buf + bytes_read;
count -= bytes_read;
}
assert(count == 0);
return 0;
}
static int write_all(int fd, const void *buf, size_t count)
{
int bytes_written;
while (count > 0) {
bytes_written = write(fd, buf, count);
assert(bytes_written > 0);
buf = (char *)buf + bytes_written;
count -= bytes_written;
}
assert(count == 0);
return 0;
}
int buse_main(int argc, char *argv[], const struct buse_operations *aop, void *userdata)
{
int sp[2];
int nbd, sk, err, tmp_fd;
u_int64_t from;
u_int32_t len, bytes_read, bytes_written;
u_int32_t len, bytes_read;
char *dev_file;
struct nbd_request request;
struct nbd_reply reply;
@ -45,8 +75,8 @@ int buse_main(int argc, char *argv[], const struct buse_operations *aop, void *u
(void) userdata;
assert(argc == 2);
dev_file = argv[1];
assert(argc == 3);
dev_file = argv[2];
assert(!socketpair(AF_UNIX, SOCK_STREAM, 0, sp));
@ -64,6 +94,8 @@ int buse_main(int argc, char *argv[], const struct buse_operations *aop, void *u
assert(ioctl(nbd, NBD_SET_SOCK, sk) != -1);
err = ioctl(nbd, NBD_DO_IT);
fprintf(stderr, "nbd device terminated with code %d\n", err);
if (err == -1)
fprintf(stderr, "%s\n", strerror(errno));
assert(ioctl(nbd, NBD_CLEAR_QUE) != -1);
assert(ioctl(nbd, NBD_CLEAR_SOCK) != -1);
@ -105,23 +137,21 @@ int buse_main(int argc, char *argv[], const struct buse_operations *aop, void *u
chunk = malloc(len + sizeof(struct nbd_reply));
aop->read((char *)chunk + sizeof(struct nbd_reply), len, from);
memcpy(chunk, &reply, sizeof(struct nbd_reply));
bytes_written = write(sk, chunk, len + sizeof(struct nbd_reply));
assert(bytes_written == len + sizeof(struct nbd_reply));
write_all(sk, chunk, len + sizeof(struct nbd_reply));
free(chunk);
break;
case NBD_CMD_WRITE:
fprintf(stderr, "Request for write of size %d\n", len);
chunk = malloc(len);
bytes_read = read(sk, chunk, len);
assert(bytes_read == len);
read_all(sk, chunk, len);
aop->write(chunk, len, from);
free(chunk);
bytes_written = write(sk, &reply, sizeof(struct nbd_reply));
assert(bytes_written == sizeof(struct nbd_reply));
write_all(sk, &reply, sizeof(struct nbd_reply));
break;
case NBD_CMD_DISC:
/* Handle a disconnect request. */
aop->disc();
break;
return 0;
case NBD_CMD_FLUSH:
aop->flush();
break;