From: Karel Zak <kzak@redhat.com>
Date: Wed, 9 Mar 2022 10:13:26 +0000 (+0100)
Subject: losetup: fix --direct-io
X-Git-Tag: v2.38-rc3~20
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5b3bb7da681abfcbbbd2cf75f23ab527ce5c8d51;p=thirdparty%2Futil-linux.git

losetup: fix --direct-io

losetup checks for empty lo_flags when A_CREATE (action) is not
requested, otherwise it prints

	"the options %s are allowed during loop device setup only"

error message. We need to cleanup lo_flags when alone --direct-io
requested.

Fix also typo in man page, "losetup --direct-io" is the same as
"losetup --direct-io=on".

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/sys-utils/losetup.8.adoc b/sys-utils/losetup.8.adoc
index 075d079fd1..0dc58fe65b 100644
--- a/sys-utils/losetup.8.adoc
+++ b/sys-utils/losetup.8.adoc
@@ -90,7 +90,7 @@ Force the kernel to scan the partition table on a newly created loop device. Not
 Set up a read-only loop device.
 
 *--direct-io*[**=on**|*off*]::
-Enable or disable direct I/O for the backing file. The optional argument can be either *on* or *off*. If the argument is omitted, it defaults to *off*.
+Enable or disable direct I/O for the backing file. The optional argument can be either *on* or *off*. If the optional argument is omitted, it defaults to *on*.
 
 *-v*, *--verbose*::
 Verbose mode.
diff --git a/sys-utils/losetup.c b/sys-utils/losetup.c
index 1d81b117ac..29bb785ab0 100644
--- a/sys-utils/losetup.c
+++ b/sys-utils/losetup.c
@@ -796,12 +796,14 @@ int main(int argc, char **argv)
 		 * OR
 		 * losetup {--direct-io[=off]|--logical-blocksize=size}... <device>
 		 */
-		if (!(set_dio || set_blocksize))
-			act = A_SHOW_ONE;
-		if (set_dio)
+		if (set_dio) {
 			act = A_SET_DIRECT_IO;
-		if (set_blocksize)
+			lo_flags &= ~LO_FLAGS_DIRECT_IO;
+		} else if (set_blocksize)
 			act = A_SET_BLOCKSIZE;
+		else
+			act = A_SHOW_ONE;
+
 		if (!is_loopdev(argv[optind]) ||
 		    loopcxt_set_device(&lc, argv[optind]))
 			err(EXIT_FAILURE, _("%s: failed to use device"),