r9: Support for changing blocksize.

diff --git a/nbd-client.c b/nbd-client.c
index dd9156c..fcc9680 100644 (file)
--- a/nbd-client.c
+++ b/nbd-client.c
@@ -5,10 +5,10 @@
  *  <pavel@atrey.karlin.mff.cuni.cz>
  *
  * Version 1.0 - 64bit issues should be fixed, now
+ * Version 1.1 - added bs (blocksize) option (Alexey Guzeev, aga@permonline.ru)
+ * Version 1.2 - I added new option '-d' to send the disconnect request
  */
 
-/* I added new option '-d' to send the disconnect request */
-
 #include <asm/page.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
@@ -60,19 +60,27 @@ int main(int argc, char *argv[])
        u64 magic, size64;
        unsigned long size;
        char buf[256] = "\0\0\0\0\0\0\0\0\0";
-       int swap = (argc > 4);
+       int blocksize=1024;
+       char *hostname;
+       int swap=0;
 
        logging();
 
-       if (argc < 2) {
+       if (argc < 3) {
        errmsg:
-               fprintf(stderr, "Usage: host port nbd_device -swap\n");
-               fprintf(stderr, "or     -d nbd_device \n");
+               fprintf(stderr, "Usage: nbd-client [bs=blocksize] host port nbd_device [-swap]\n");
+               fprintf(stderr, "Or   : nbd-client -d nbd_device\n");
+               fprintf(stderr, "Default value for blocksize is 1024 (recommended for ethernet)\n");
+               fprintf(stderr, "Allowed values for blocksize are 512,1024,2048,4096\n"); /* will be checked in kernel :) */
+               fprintf(stderr, "Note, that kernel 2.4.2 and older ones do not work correctly with\n");
+               fprintf(stderr, "blocksizes other than 1024 without patches\n");
                return 1;
        }
 
-       if (strcmp(argv[1],"-d")==0) {
-         nbd = open(argv[2], O_RDWR);
+       ++argv; --argc; /* skip programname */
+       
+       if (strcmp(argv[0], "-d")==0) {
+         nbd = open(argv[1], O_RDWR);
          if (nbd < 0)
                err("Can not open NBD: %m");
          printf("Disconnecting: que, ");
@@ -84,20 +92,38 @@ int main(int argc, char *argv[])
                err("Ioctl failed: %m\n");
          printf("sock, ");
 #else
-         die("Can't disconnect: I was not compiled with disconnect support!\n" );
+         fprintf(stderr, "Can't disconnect: I was not compiled with disconnect support!\n" );
+         exit(1);
 #endif
          if (ioctl(nbd, NBD_CLEAR_SOCK)<0)
                err("Ioctl failed: %m\n");
          printf("done\n");
          return 0;
        }
-       
-       if (argc<4) goto errmsg;
-       port = atoi(argv[2]);
-       sock = opennet(argv[1], port);
-       nbd = open(argv[3], O_RDWR);
+
+       if (strncmp(argv[0], "bs=", 3)==0) {
+         blocksize=atoi(argv[0]+3);
+         ++argv; --argc; /* skip blocksize */
+       }
+
+       if (argc==0) goto errmsg;
+       hostname=argv[0];
+       ++argv; --argc; /* skip hostname */
+
+       if (argc==0) goto errmsg;
+       port = atoi(argv[0]);
+       ++argv; --argc; /* skip port */
+
+       if (argc==0) goto errmsg;
+       sock = opennet(hostname, port);
+       nbd = open(argv[0], O_RDWR);
        if (nbd < 0)
          err("Can not open NBD: %m");
+       ++argv; --argc; /* skip device */
+
+       if (argc>1) goto errmsg;
+       if (argc!=0) swap=1;
+       argv=NULL; argc=0; /* don't use it later suddenly */
 
        printf("Negotiation: ");
        if (read(sock, buf, 8) < 0)
@@ -115,50 +141,47 @@ int main(int argc, char *argv[])
        if (read(sock, &size64, sizeof(size64)) < 0)
                err("Failed/3: %m\n");
        size64 = ntohll(size64);
-       if (size64 > (~0UL >> 1)) {
+
 #ifdef NBD_SET_SIZE_BLOCKS
-               if ((size64 >> 10) > (~0UL >> 1)) {
-                       printf("size = %luMB", (unsigned long)(size64>>20));
-                       err("Exported device is too big for me. Get 64-bit machine :-(\n");
-               } else
-                       printf("size = %luKB", (unsigned long)(size64>>10));
+       if ((size64>>10) > (~0UL >> 1)) {
+               printf("size = %luMB", (unsigned long)(size64>>20));
+               err("Exported device is too big for me. Get 64-bit machine :-(\n");
+       } else
+               printf("size = %luKB", (unsigned long)(size64>>10));
 #else
+       if (size64 > (~0UL >> 1)) {
                printf("size = %luKB", (unsigned long)(size64>>10));
                err("Exported device is too big. Get 64-bit machine or newer kernel :-(\n");
-#endif
        } else
                printf("size = %lu", (unsigned long)(size64));
+#endif
 
        if (read(sock, &buf, 128) < 0)
                err("Failed/4: %m\n");
        printf("\n");
 
-       if (size64 > (~0UL >> 1)) {
 #ifdef NBD_SET_SIZE_BLOCKS
-               if ((size64 >> 10) > (~0UL >> 1))
-               /*
-                * If you really need NBDs larger than 2TB on 32-bit
-                * machines you can use blocksizes larger than 1kB
-                * - FIXME
-                */
-                       err("Device too large.\n");
-               else {
-                       int er;
-
-                       if (ioctl(nbd, NBD_SET_BLKSIZE, 1UL << 10) < 0)
-                               err("Ioctl/1.1a failed: %m\n");
-                       size = (unsigned long)(size64 >> 10);
-                       if ((er = ioctl(nbd, NBD_SET_SIZE_BLOCKS, size)) < 0)
-                               err("Ioctl/1.1b failed: %m\n");
-               }
+       if (size64/blocksize > (~0UL >> 1))
+               err("Device too large.\n");
+       else {
+               int er;
+               if (ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long)blocksize) < 0)
+                       err("Ioctl/1.1a failed: %m\n");
+               size = (unsigned long)(size64/blocksize);
+               if ((er = ioctl(nbd, NBD_SET_SIZE_BLOCKS, size)) < 0)
+                       err("Ioctl/1.1b failed: %m\n");
+fprintf(stderr, "bs=%d, sz=%lu\n", blocksize, size);
+       }
 #else
+       if (size64 > (~0UL >> 1)) {
                err("Device too large.\n");
-#endif
        } else {
                size = (unsigned long)size64;
                if (ioctl(nbd, NBD_SET_SIZE, size) < 0)
                        err("Ioctl/1 failed: %m\n");
        }
+#endif
+
        ioctl(nbd, NBD_CLEAR_SOCK);
        if (ioctl(nbd, NBD_SET_SOCK, sock) < 0)
                err("Ioctl/2 failed: %m\n");