From: Stanislav Brabec Date: Thu, 12 Jan 2017 14:45:27 +0000 (+0100) Subject: libmount: fix mount -oloop=/dev/loopX regression X-Git-Tag: v2.30-rc1~302 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3789806db21dea8e009ceea8f6158bc778151afe;p=thirdparty%2Futil-linux.git libmount: fix mount -oloop=/dev/loopX regression If mount option "loop" is used with an argument, it should be respected. Commit 8efad715 introduced a regression. Even with an argument, overlaying loop device is searched and argument is ignored. It could have unexpected side effects. If argument is set, never allocate a new loop device. How to reproduce: mkdir -p cdrom mkisofs -o cdrom.iso cdrom/ 2>/dev/null losetup /dev/loop0 cdrom.iso strace mount -t auto -o ro,loop=/dev/loop1 cdrom.iso /mnt 2>&1 | grep ^mount cat /proc/self/mountinfo | grep /mnt umount /mnt losetup -d /dev/loop0 mount("/dev/loop0", "/mnt", "iso9660", MS_MGC_VAL|MS_RDONLY, NULL) = 0 327 60 7:0 / /mnt ro,relatime shared:241 - iso9660 /dev/loop0 ro losetup: /dev/loop0: detach failed: No such device or address Signed-off-by: Stanislav Brabec --- diff --git a/libmount/src/context_loopdev.c b/libmount/src/context_loopdev.c index 8ef183107e..18eb2cc56c 100644 --- a/libmount/src/context_loopdev.c +++ b/libmount/src/context_loopdev.c @@ -259,7 +259,12 @@ int mnt_context_setup_loopdev(struct libmnt_context *cxt) goto done; } rc = 0; - goto success; + /* loop= used with argument. Conflict will occur. */ + if (loopval) { + rc = -MNT_ERR_LOOPOVERLAP; + goto done; + } else + goto success; } default: /* error */ goto done;