From patchwork Mon Jun 14 09:44:24 2010
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Subject: [2/5,block] : Add BSG qemu_open() in block/raw.c:raw_open()
From: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
X-Patchwork-Id: 55512
Message-Id: <1276508664-3043-1-git-send-email-nab@linux-iscsi.org>
To: Gerd Hoffmann <kraxel@redhat.com>, Kevin Wolf <kwolf@redhat.com>,
 FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: kvm-devel <kvm@vger.kernel.org>, qemu-devel <qemu-devel@nongnu.org>,
 Nicholas Bellinger <nab@linux-iscsi.org>,
 Hannes Reinecke <hare@suse.de>, Christoph Hellwig <hch@lst.de>,
 Paul Brook <paul@codesourcery.com>
Date: Mon, 14 Jun 2010 02:44:24 -0700

From: Nicholas Bellinger <nab@linux-iscsi.org>

This patch adds a BSG specific qemu_open() call in block/raw.c:raw_open() that
saves the opened file descriptor for BSG AIO into BlockDriverState->fd.

It also adds the reverse close() call to block/raw.c:raw_close()

Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>

---
block/raw.c |   20 ++++++++++++++++++++
 1 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/block/raw.c b/block/raw.c
index 4406b8c..7820c78 100644
--- a/block/raw.c
+++ b/block/raw.c
@@ -5,7 +5,25 @@
 
 static int raw_open(BlockDriverState *bs, int flags)
 {
+    int fd, ret;
+
     bs->sg = bs->file->sg;
+    /*
+     * scsi-generic and other raw types do not call qemu_open()
+      */
+    if (bs->sg != BDS_BSG)
+        return 0;
+    /*
+     * Obtain a file descriptor for the underlying BSG device for AIO w/ iovecs
+     */
+    fd = qemu_open(bs->filename, flags, 0644);
+    if (fd < 0) {
+        ret = -errno;
+        if (ret == -EROFS)
+            ret = -EACCES;
+        return ret;
+    }
+    bs->fd = fd;
     return 0;
 }
 
@@ -37,6 +55,8 @@ static BlockDriverAIOCB *raw_aio_writev(BlockDriverState *bs,
 
 static void raw_close(BlockDriverState *bs)
 {
+    if (bs->fd > 0)
+        close(bs->fd);
 }
 
 static void raw_flush(BlockDriverState *bs)