r279: * Mention -persist in nbd-client manpage

[nbd.git] / nbd-client.c

diff --git a/nbd-client.c b/nbd-client.c
index 02dce78..8771d40 100644 (file)
--- a/nbd-client.c
+++ b/nbd-client.c
@@ -16,7 +16,6 @@
 #include "config.h"
 #include "lfs.h"
 
-#include <asm/page.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
 #include <sys/types.h>
@@ -28,6 +27,7 @@
 #include <fcntl.h>
 #include <syslog.h>
 #include <stdlib.h>
+#include <sys/mount.h>
 
 #ifndef __GNUC__
 #error I need GCC to work
@@ -60,7 +60,7 @@ int opennet(char *name, int port) {
        return sock;
 }
 
-u64 negotiate(int sock, int blocksize) {
+void negotiate(int sock, u64 *rsize64, u32 *flags) {
        u64 magic, size64;
        char buf[256] = "\0\0\0\0\0\0\0\0\0";
 
@@ -97,15 +97,20 @@ u64 negotiate(int sock, int blocksize) {
                printf("size = %lu", (unsigned long)(size64));
 #endif
 
-       if (read(sock, &buf, 128) < 0)
+       if (read(sock, flags, sizeof(*flags)) < 0)
                err("Failed/4: %m\n");
+       *flags = ntohl(*flags);
+
+       if (read(sock, &buf, 124) < 0)
+               err("Failed/5: %m\n");
        printf("\n");
 
-       return size64;
+       *rsize64 = size64;
 }
 
-void setsizes(int nbd, u64 size64, int blocksize) {
+void setsizes(int nbd, u64 size64, int blocksize, u32 flags) {
        unsigned long size;
+       int read_only = (flags & NBD_FLAG_READ_ONLY) ? 1 : 0;
 
 #ifdef NBD_SET_SIZE_BLOCKS
        if (size64/blocksize > (~0UL >> 1))
@@ -130,6 +135,9 @@ void setsizes(int nbd, u64 size64, int blocksize) {
 #endif
 
        ioctl(nbd, NBD_CLEAR_SOCK);
+
+       if (ioctl(nbd, BLKROSET, (unsigned long) &read_only) < 0)
+               err("Unable to set read-only attribute for device");
 }
 
 void finish_sock(int sock, int nbd, int swap) {
@@ -152,7 +160,9 @@ int main(int argc, char *argv[]) {
        char *hostname, *nbddev;
        int swap=0;
        int cont=0;
+       int timeout=0;
        u64 size64;
+       u32 flags;
 
        logging();
 
@@ -213,7 +223,7 @@ int main(int argc, char *argv[]) {
          err("Can not open NBD: %m");
        ++argv; --argc; /* skip device */
 
-       if (argc>2) goto errmsg;
+       if (argc>3) goto errmsg;
        if (argc!=0) {
                if(strncmp(argv[0], "-swap", 5)==0) {
                        swap=1;
@@ -226,10 +236,21 @@ int main(int argc, char *argv[]) {
                        ++argv;--argc;
                }
        }
+       if(argc!=0) {
+               if(strncmp(argv[0], "-timeout", 8)==0) {
+#ifdef NBD_SET_TIMEOUT
+                       timeout=strtol(++argv, NULL, 0);
+                       ++argv;--argc--;
+#else
+                       fprintf(stderr, "This nbd-client does not support -timeout yet; please recompile on a more recent kernel");
+                       exit(EXIT_FAILURE);
+#endif
+               }
+       }
        argv=NULL; argc=0; /* don't use it later suddenly */
 
-       size64 = negotiate(sock, blocksize);
-       setsizes(nbd, size64, blocksize);
+       negotiate(sock, &size64, &flags);
+       setsizes(nbd, size64, blocksize, flags);
        finish_sock(sock, nbd, swap);
 
        /* Go daemon */
@@ -240,6 +261,12 @@ int main(int argc, char *argv[]) {
                exit(0);
 #endif
 
+#ifdef NBD_SET_TIMEOUT
+       if(ioctl(nbd, NBD_SET_TIMEOUT, &timeout)<0) {
+               fprintf(stderr, "Setting timeout failed: %m");
+               exit(EXIT_FAILURE);
+       }
+#endif
        do {
                if (ioctl(nbd, NBD_DO_IT) < 0) {
                        fprintf(stderr, "Kernel call returned: %m");
@@ -249,14 +276,20 @@ int main(int argc, char *argv[]) {
                                cont=0;
                        } else {
                                if(cont) {
+                                       u64 new_size;
+                                       u32 new_flags;
+
                                        fprintf(stderr, " Reconnecting\n");
                                        close(sock); close(nbd);
                                        sock = opennet(hostname, port);
                                        nbd = open(nbddev, O_RDWR);
-                                       if(size64!=negotiate(sock,blocksize)) {
+                                       negotiate(sock, &new_size, &new_flags);
+                                       if (size64 != new_size) {
                                                err("Size of the device changed. Bye");
                                        }
-                                       setsizes(nbd, size64, blocksize);
+                                       setsizes(nbd, size64, blocksize,
+                                                               new_flags);
+
                                        finish_sock(sock,nbd,swap);
                                }
                        }