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authorPaolo Bonzini <pbonzini@redhat.com>2012-11-13 10:34:17 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2012-11-13 10:34:50 +0100
commitc8969eded252058e90e91f12f75f32aceae46ec9 (patch)
tree14e528a0f44ee303a92b714ae6fefaa54ae2886e /nbd.c
parent4057725f35abe00ea371f85c6e27dd25eafd9ddf (diff)
downloadqemu-arm-c8969eded252058e90e91f12f75f32aceae46ec9.tar.gz
nbd: fixes to read-only handling
We do not need BLKROSET if the kernel supports setting flags. Also, always do BLKROSET even for a read-write export, otherwise the read-only state remains "sticky" after the invocation of "qemu-nbd -r". Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'nbd.c')
-rw-r--r--nbd.c25
1 files changed, 12 insertions, 13 deletions
diff --git a/nbd.c b/nbd.c
index cec5a9449b..97a5914e0f 100644
--- a/nbd.c
+++ b/nbd.c
@@ -596,24 +596,23 @@ int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
return -serrno;
}
- if (flags & NBD_FLAG_READ_ONLY) {
- int read_only = 1;
- TRACE("Setting readonly attribute");
-
- if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
+ if (ioctl(fd, NBD_SET_FLAGS, flags) < 0) {
+ if (errno == ENOTTY) {
+ int read_only = (flags & NBD_FLAG_READ_ONLY) != 0;
+ TRACE("Setting readonly attribute");
+
+ if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
+ int serrno = errno;
+ LOG("Failed setting read-only attribute");
+ return -serrno;
+ }
+ } else {
int serrno = errno;
- LOG("Failed setting read-only attribute");
+ LOG("Failed setting flags");
return -serrno;
}
}
- if (ioctl(fd, NBD_SET_FLAGS, flags) < 0
- && errno != ENOTTY) {
- int serrno = errno;
- LOG("Failed setting flags");
- return -serrno;
- }
-
TRACE("Negotiation ended");
return 0;