From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:50069) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TfeIi-0007Zs-A1 for qemu-devel@nongnu.org; Mon, 03 Dec 2012 17:15:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TfeIg-000368-Sc for qemu-devel@nongnu.org; Mon, 03 Dec 2012 17:15:44 -0500 Sender: fluxion From: Michael Roth Date: Mon, 3 Dec 2012 16:08:43 -0600 Message-Id: <1354572547-21271-20-git-send-email-mdroth@linux.vnet.ibm.com> In-Reply-To: <1354572547-21271-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1354572547-21271-1-git-send-email-mdroth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 19/43] nbd: fixes to read-only handling List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-stable@nongnu.org Cc: aliguori@us.ibm.com, qemu-devel@nongnu.org From: Paolo Bonzini 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 (cherry picked from commit c8969eded252058e90e91f12f75f32aceae46ec9) Signed-off-by: Michael Roth --- nbd.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) diff --git a/nbd.c b/nbd.c index 206f75c..19f6cd8 100644 --- a/nbd.c +++ b/nbd.c @@ -399,24 +399,23 @@ 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; -- 1.7.9.5