From: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Date: Wed, 8 Dec 2021 17:09:53 +0000 (-0800)
Subject: libblkid/src/probe: check for ENOMEDIUM from ioctl(CDROM_LAST_WRITTEN)
X-Git-Tag: v2.38-rc1~97
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c80b3f3200486d8f11a56afa9bb2c27b9cc4ffe3;p=thirdparty%2Futil-linux.git

libblkid/src/probe: check for ENOMEDIUM from ioctl(CDROM_LAST_WRITTEN)

The CD device on Azure VMs returns CDS_DISC_OK from CDROM_DRIVE_STATUS even
when no disc is present. In that case an ENOMEDIUM from CDROM_LAST_WRITTEN
follows. Catch that and return error to prevent probing which results in
hundreds of "unaligned transfer" warnings in the kernel logbuffer.

Signed-off-by: Jeremi Piotrowski <jpiotrowski@microsoft.com>
---

diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c
index 3685ea5e13..513649916d 100644
--- a/libblkid/src/probe.c
+++ b/libblkid/src/probe.c
@@ -994,8 +994,12 @@ int blkid_probe_set_device(blkid_probe pr, int fd,
 		}
 
 # ifdef CDROM_LAST_WRITTEN
-		if (ioctl(fd, CDROM_LAST_WRITTEN, &last_written) == 0)
+		if (ioctl(fd, CDROM_LAST_WRITTEN, &last_written) == 0) {
 			pr->flags |= BLKID_FL_CDROM_DEV;
+		} else {
+			if (errno == ENOMEDIUM)
+				goto err;
+		}
 # endif
 
 		if (pr->flags & BLKID_FL_CDROM_DEV) {