[Qemu-devel] [PATCH V3 1/2] Update ioctl order in nbd_init to detect -EBUSY

[Chunyan Liu <cyliu@suse.com>]

Remove NBD_CLEAR_SOCK from nbd_init and adjust NBD_SET_SOCK ioctl before other
ioctl(s) in nbd_init so that it can detect -EBUSY properly.
 
Signed-off-by: Chunyan Liu <cyliu@suse.com>
---
 nbd.c |   27 +++++++++------------------
 1 files changed, 9 insertions(+), 18 deletions(-)

diff --git a/nbd.c b/nbd.c
index e6c931c..4184614 100644
--- a/nbd.c
+++ b/nbd.c
@@ -348,6 +348,15 @@ int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
 #ifdef __linux__
 int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
 {
+    TRACE("Setting NBD socket");
+
+    if (ioctl(fd, NBD_SET_SOCK, csock) == -1) {
+        int serrno = errno;
+        LOG("Failed to set NBD socket");
+        errno = serrno;
+        return -1;
+    }
+
     TRACE("Setting block size to %lu", (unsigned long)blocksize);
 
     if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) {
@@ -386,24 +395,6 @@ int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
         return -1;
     }
 
-    TRACE("Clearing NBD socket");
-
-    if (ioctl(fd, NBD_CLEAR_SOCK) == -1) {
-        int serrno = errno;
-        LOG("Failed clearing NBD socket");
-        errno = serrno;
-        return -1;
-    }
-
-    TRACE("Setting NBD socket");
-
-    if (ioctl(fd, NBD_SET_SOCK, csock) == -1) {
-        int serrno = errno;
-        LOG("Failed to set NBD socket");
-        errno = serrno;
-        return -1;
-    }
-
     TRACE("Negotiation ended");
 
     return 0;
-- 
1.7.3.4