lib: Ensure we don't find bind mounts for device target

There's comment here that `--source` somehow avoids bind mounts, but that appears not to be the case in my testing. I think we just happened to be lucky before now with the `--first` picking the value we wanted. Instead of using `--first` and hoping for the best, parse the mounts and skip ones which are bind mounts explicitly. Signed-off-by: Colin Walters <[email protected]> Reviewed-by: Lichen Liu <[email protected]>
rhkdump · Aug 23, 2024 · 3f9dbcc · 3f9dbcc
1 parent 51d58ee
commit 3f9dbcc
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diff --git a/kdump-lib-initramfs.sh b/kdump-lib-initramfs.sh
@@ -102,8 +102,19 @@ get_fs_type_from_target()
 
 get_mntpoint_from_target()
 {
-	# --source is applied to ensure non-bind mount is returned
-	get_mount_info TARGET source "$1" -f
+	# omit sources that are bind mounts i.e. they contain a [/path/to/subpath].
+	findmnt -k --pairs -o SOURCE,TARGET "$1" | while read -r _source _target; do
+		_source="${_source#SOURCE=\"}"
+		_source="${_source%%\"}"
+
+		_target="${_target#*TARGET=\"}"
+		_target="${_target%%\"}"
+
+		if ! expr "X$_source" : 'X.*\[' > /dev/null; then
+			echo "$_target"
+			break
+		fi
+	done
 }
 
 is_ssh_dump_target()

diff --git a/kdump-lib.sh b/kdump-lib.sh
@@ -221,7 +221,7 @@ get_bind_mount_source()
 
 	_fsroot=${_src#"${_src_nofsroot}"[}
 	_fsroot=${_fsroot%]}
-	_mnt=$(get_mount_info TARGET source "$_src_nofsroot" -f)
+	_mnt=$(get_mntpoint_from_target "$_src_nofsroot")
 
 	# for btrfs, _fsroot will also contain the subvol value as well, strip it
 	if [[ $_fstype == btrfs ]]; then