From: Michal Suchanek <msuchanek@suse.de>
Date: Mon, 4 Nov 2019 20:23:15 +0000 (+0100)
Subject: libblkid: open device in nonblock mode.
X-Git-Tag: v2.35-rc1~72
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=39f5af25982d8b0244000e92a9d0e0e6557d0e17;p=thirdparty%2Futil-linux.git

libblkid: open device in nonblock mode.

When autoclose is set (kernel default but many distributions reverse the
setting) opening a CD-rom device causes the tray to close.

The function of blkid is to report the current state of the device and
not to change it. Hence it should use O_NONBLOCK when opening the
device to avoid closing a CD-rom tray.

blkid is used liberally in scripts so it can potentially interfere with
the user operating the CD-rom hardware.

[kzak@redhat.com: add O_NONBLOCK also to:
                  - wipefs
                  - blkid_new_probe_from_filename()
                  - blkid_evaluate_tag()]

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/libblkid/src/evaluate.c b/libblkid/src/evaluate.c
index 51e5b058db..8ba8bd5f37 100644
--- a/libblkid/src/evaluate.c
+++ b/libblkid/src/evaluate.c
@@ -70,7 +70,7 @@ static int verify_tag(const char *devname, const char *name, const char *value)
 	blkid_probe_enable_partitions(pr, TRUE);
 	blkid_probe_set_partitions_flags(pr, BLKID_PARTS_ENTRY_DETAILS);
 
-	fd = open(devname, O_RDONLY|O_CLOEXEC);
+	fd = open(devname, O_RDONLY|O_CLOEXEC|O_NONBLOCK);
 	if (fd < 0) {
 		errsv = errno;
 		goto done;
diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c
index 790168c16c..f6dd5573d5 100644
--- a/libblkid/src/probe.c
+++ b/libblkid/src/probe.c
@@ -203,7 +203,7 @@ blkid_probe blkid_new_probe_from_filename(const char *filename)
 	int fd;
 	blkid_probe pr = NULL;
 
-	fd = open(filename, O_RDONLY|O_CLOEXEC);
+	fd = open(filename, O_RDONLY|O_CLOEXEC|O_NONBLOCK);
 	if (fd < 0)
 		return NULL;
 
diff --git a/libblkid/src/verify.c b/libblkid/src/verify.c
index a78c9f8f2a..4bda3fd40c 100644
--- a/libblkid/src/verify.c
+++ b/libblkid/src/verify.c
@@ -126,7 +126,7 @@ blkid_dev blkid_verify(blkid_cache cache, blkid_dev dev)
 		}
 	}
 
-	fd = open(dev->bid_name, O_RDONLY|O_CLOEXEC);
+	fd = open(dev->bid_name, O_RDONLY|O_CLOEXEC|O_NONBLOCK);
 	if (fd < 0) {
 		DBG(PROBE, ul_debug("blkid_verify: error %m (%d) while "
 					"opening %s", errno,
diff --git a/misc-utils/blkid.c b/misc-utils/blkid.c
index f2583d2b88..0df9f6b6f2 100644
--- a/misc-utils/blkid.c
+++ b/misc-utils/blkid.c
@@ -499,7 +499,7 @@ static int lowprobe_device(blkid_probe pr, const char *devname,
 	int rc = 0;
 	static int first = 1;
 
-	fd = open(devname, O_RDONLY|O_CLOEXEC);
+	fd = open(devname, O_RDONLY|O_CLOEXEC|O_NONBLOCK);
 	if (fd < 0) {
 		warn(_("error: %s"), devname);
 		return BLKID_EXIT_NOTFOUND;
diff --git a/misc-utils/wipefs.c b/misc-utils/wipefs.c
index be728279bd..313ddc36e5 100644
--- a/misc-utils/wipefs.c
+++ b/misc-utils/wipefs.c
@@ -386,7 +386,7 @@ new_probe(const char *devname, int mode)
 		return NULL;
 
 	if (mode) {
-		int fd = open(devname, mode);
+		int fd = open(devname, mode | O_NONBLOCK);
 		if (fd < 0)
 			goto error;