[Qemu-devel] [PATCH] raw-posix: Detect CDROM via ioctl

[Cole Robinson]

Current CDROM detection is hardcoded based on source file name.
Make this smarter by attempting a CDROM specific ioctl.

This makes '-cdrom /dev/sr0' succeed with no media present.

Signed-off-by: Cole Robinson <address@hidden>
---
 block/raw-posix.c |   18 +++++++++++++++++-
 1 files changed, 17 insertions(+), 1 deletions(-)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index 5a6a22b..3ec58d0 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -1140,9 +1140,25 @@ static int cdrom_open(BlockDriverState *bs, const char 
*filename, int flags)
 
 static int cdrom_probe_device(const char *filename)
 {
+    int fd, ret;
+
     if (strstart(filename, "/dev/cd", NULL))
         return 100;
-    return 0;
+
+    fd = open(filename, O_RDONLY | O_NONBLOCK);
+    if (fd < 0) {
+        return 0;
+    }
+
+    /* Attempt to detect via a CDROM specific ioctl */
+    if (ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT) < 0 && errno == EINVAL) {
+        ret = 0;
+    } else {
+        ret = 100;
+    }
+
+    close(fd);
+    return ret;
 }
 
 static int cdrom_is_inserted(BlockDriverState *bs)
-- 
1.6.6