* buse.c: Fixed a bug in read op.

buse.c

@@ -61,23 +61,17 @@ static int write_all(int fd, char* buf, size_t count)
   return 0;
 }
 
-int buse_main(int argc, char *argv[], const struct buse_operations *aop, void *userdata)
+int buse_main(const char* dev_file, const struct buse_operations *aop, void *userdata)
 {
   int sp[2];
   int nbd, sk, err, tmp_fd;
   u_int64_t from;
   u_int32_t len;
   ssize_t bytes_read;
-  char *dev_file;
   struct nbd_request request;
   struct nbd_reply reply;
   void *chunk;
 
-  (void) userdata;
-
-  assert(argc == 2);
-  dev_file = argv[1];
-
   assert(!socketpair(AF_UNIX, SOCK_STREAM, 0, sp));
 
   nbd = open(dev_file, O_RDWR);
@@ -139,32 +133,32 @@ int buse_main(int argc, char *argv[], const struct buse_operations *aop, void *u
        * and writes.
        */
     case NBD_CMD_READ:
-      /* fprintf(stderr, "Request for read of size %d\n", len); */
+      fprintf(stderr, "Request for read of size %d\n", len);
-      chunk = malloc(len + sizeof(struct nbd_reply));
+      chunk = malloc(len);
-      reply.error = aop->read((char *)chunk + sizeof(struct nbd_reply), len, from);
+      reply.error = aop->read(chunk, len, from, userdata);
       write_all(sk, (char*)&reply, sizeof(struct nbd_reply));
       if(reply.error == 0)
 	write_all(sk, (char*)chunk, len);
       free(chunk);
       break;
     case NBD_CMD_WRITE:
-      /* fprintf(stderr, "Request for write of size %d\n", len); */
+      fprintf(stderr, "Request for write of size %d\n", len);
       chunk = malloc(len);
       read_all(sk, chunk, len);
-      reply.error = aop->write(chunk, len, from);
+      reply.error = aop->write(chunk, len, from, userdata);
       free(chunk);
       write_all(sk, (char*)&reply, sizeof(struct nbd_reply));
       break;
     case NBD_CMD_DISC:
       /* Handle a disconnect request. */
-      aop->disc();
+      aop->disc(userdata);
       return 0;
     case NBD_CMD_FLUSH:
-      reply.error = aop->flush();
+      reply.error = aop->flush(userdata);
       write_all(sk, (char*)&reply, sizeof(struct nbd_reply));
       break;
     case NBD_CMD_TRIM:
-      reply.error = aop->trim(from, len);
+      reply.error = aop->trim(from, len, userdata);
       write_all(sk, (char*)&reply, sizeof(struct nbd_reply));
       break;
     default:

buse.h

@@ -64,17 +64,16 @@ struct nbd_reply {
   };
 
   struct buse_operations {
-    int (*read)(void *buf, u_int32_t len, u_int64_t offset);
+    int (*read)(void *buf, u_int32_t len, u_int64_t offset, void *userdata);
-    int (*write)(const void *buf, u_int32_t len, u_int64_t offset);
+    int (*write)(const void *buf, u_int32_t len, u_int64_t offset, void *userdata);
-    void (*disc)();
+    void (*disc)(void *userdata);
-    int (*flush)();
+    int (*flush)(void *userdata);
-    int (*trim)(u_int64_t from, u_int32_t len);
+    int (*trim)(u_int64_t from, u_int32_t len, void *userdata);
 
     u_int64_t size;
   };
 
-int buse_main(int argc, char *argv[], const struct buse_operations *bop,
+  int buse_main(const char* dev_file, const struct buse_operations *bop, void *userdata);
-        void *userdata);
 
 #ifdef __cplusplus
 }

busexmp.c

@@ -6,32 +6,32 @@
 
 static void *data;
 
-static int xmp_read(void *buf, u_int32_t len, u_int64_t offset)
+static int xmp_read(void *buf, u_int32_t len, u_int64_t offset, void *userdata)
 {
   fprintf(stderr, "R - %lu, %u\n", offset, len);
   memcpy(buf, (char *)data + offset, len);
   return 0;
 }
 
-static int xmp_write(const void *buf, u_int32_t len, u_int64_t offset)
+static int xmp_write(const void *buf, u_int32_t len, u_int64_t offset, void *userdata)
 {
   fprintf(stderr, "W - %lu, %u\n", offset, len);
   memcpy((char *)data + offset, buf, len);
   return 0;
 }
 
-static void xmp_disc()
+static void xmp_disc(void *userdata)
 {
   fprintf(stderr, "Received a disconnect request.\n");
 }
 
-static int xmp_flush()
+static int xmp_flush(void *userdata)
 {
   fprintf(stderr, "Received a flush request.\n");
   return 0;
 }
 
-static int xmp_trim(u_int64_t from, u_int32_t len){
+static int xmp_trim(u_int64_t from, u_int32_t len, void *userdata){
   fprintf(stderr, "T - %lu, %u\n", from, len);
   return 0;
 }
@@ -50,5 +50,5 @@ int main(int argc, char *argv[])
 {
   data = malloc(aop.size);
 
-  return buse_main(argc, argv, &aop, NULL);
+  return buse_main(argv[1], &aop, NULL);
 }

loopback.c

@@ -18,7 +18,7 @@ static void usage(void)
     fprintf(stderr, "Usage: loopback <phyical device> <virtual device>\n");
 }
 
-static int loopback_read(void *buf, u_int32_t len, u_int64_t offset)
+static int loopback_read(void *buf, u_int32_t len, u_int64_t offset, void *userdata)
 {
     int bytes_read;
 
@@ -33,7 +33,7 @@ static int loopback_read(void *buf, u_int32_t len, u_int64_t offset)
     return 0;
 }
 
-static int loopback_write(const void *buf, u_int32_t len, u_int64_t offset)
+static int loopback_write(const void *buf, u_int32_t len, u_int64_t offset, void *userdata)
 {
     int bytes_written;
 
@@ -78,7 +78,7 @@ int main(int argc, char *argv[])
     fprintf(stderr, "The size of this device is %ld bytes.\n", size);
     bop.size = size;
 
-    buse_main(argc, argv, &bop, NULL);
+    buse_main(argv[1], &bop, NULL);
 
     return 0;
 }