[Qemu-devel] [PATCH 2/3] qemu-nbd: Extend read-only option to nbd device file

[Ryota Ozaki <ozaki.ryota@gmail.com>]

This patch allows to operate on nbd device file
without write permission for the file if read-only
option is specified.

Signed-off-by: Ryota Ozaki <ozaki.ryota@gmail.com>
---
 qemu-nbd.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/qemu-nbd.c b/qemu-nbd.c
index 00b8896..7ef409f 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -162,7 +162,7 @@ static int find_partition(BlockDriverState *bs, int partition,
     return -1;
 }
 
-static void show_parts(const char *device)
+static void show_parts(const char *device, bool readonly)
 {
     if (fork() == 0) {
         int nbd;
@@ -172,7 +172,7 @@ static void show_parts(const char *device)
          * but remember to load the module with max_part != 0 :
          *     modprobe nbd max_part=63
          */
-        nbd = open(device, O_RDWR);
+        nbd = open(device, readonly ? O_RDONLY : O_RDWR);
         if (nbd != -1) {
               close(nbd);
         }
@@ -322,7 +322,7 @@ int main(int argc, char **argv)
     }
 
     if (disconnect) {
-        fd = open(argv[optind], O_RDWR);
+        fd = open(argv[optind], readonly ? O_RDONLY : O_RDWR);
         if (fd == -1) {
             errx(EXIT_FAILURE, "Cannot open %s", argv[optind]);
         }
@@ -392,7 +392,7 @@ int main(int argc, char **argv)
                 }
             } while (sock == -1);
 
-            fd = open(device, O_RDWR);
+            fd = open(device, readonly ? O_RDONLY : O_RDWR);
             if (fd == -1) {
                 ret = 1;
                 goto out;
@@ -415,7 +415,7 @@ int main(int argc, char **argv)
 
 	    /* update partition table */
 
-            show_parts(device);
+            show_parts(device, readonly);
 
             nbd_client(fd, sock);
             close(fd);
-- 
1.6.5.2