[Libguestfs] [PATCH v8 1/6] daemon: Changing the way that we detect if a device contains partitions.

Instead of using part_to_dev to find such devices we open the device's directory under /sys/block/<dev_name> and look for entries starting with <dev_name>, eg. /sys/block/sda/sda1. --- daemon/listfs.ml | 41 ++++++++++++++++++++++------------------- 1 file changed, 22 insertions(+), 19 deletions(-) diff --git a/daemon/listfs.ml b/daemon/listfs.ml index 56ebadeda..eced55bce 100644 --- a/daemon/listfs.ml +++ b/daemon/listfs.ml @@ -24,31 +24,15 @@ let rec list_filesystems () = let has_lvm2 = Optgroups.lvm2_available () in let has_ldm = Optgroups.ldm_available () in + (* Devices. *) let devices = Devsparts.list_devices () in - let partitions = Devsparts.list_partitions () in - let mds = Md.list_md_devices () in - - (* Look to see if any devices directly contain filesystems - * (RHBZ#590167). However vfs-type will fail to tell us anything - * useful about devices which just contain partitions, so we also - * get the list of partitions and exclude the corresponding devices - * by using part-to-dev. - *) - let devices_containing_partitions = List.fold_left ( - fun set part -> - StringSet.add (Devsparts.part_to_dev part) set - ) StringSet.empty partitions in - let devices = List.filter ( - fun dev -> - not (StringSet.mem dev devices_containing_partitions) - ) devices in - - (* Use vfs-type to check for filesystems on devices. *) + let devices = List.filter is_not_partitioned_device devices in let ret = List.filter_map check_with_vfs_type devices in (* Use vfs-type to check for filesystems on partitions, but * ignore MBR partition type 42 used by LDM. *) + let partitions = Devsparts.list_partitions () in let ret = ret @ List.filter_map ( @@ -60,6 +44,7 @@ let rec list_filesystems () = ) partitions in (* Use vfs-type to check for filesystems on md devices. *) + let mds = Md.list_md_devices () in let ret = ret @ List.filter_map check_with_vfs_type mds in (* LVM. *) @@ -85,6 +70,24 @@ let rec list_filesystems () = List.flatten ret +(* Look to see if device can directly contain filesystem (RHBZ#590167). + * Partitioned devices cannot contain filesystem, so we will exclude + * such devices. + *) +and is_not_partitioned_device device = + assert (String.is_prefix device "/dev/"); + let dev_name = String.sub device 5 (String.length device - 5) in + let dev_dir = "/sys/block/" ^ dev_name in + + (* Open the device's directory under /sys/block/<dev_name> and + * look for entries starting with <dev_name>, eg. /sys/block/sda/sda1 + *) + let is_device_partition file = String.is_prefix file dev_name in + let files = Array.to_list (Sys.readdir dev_dir) in + let has_partition = List.exists is_device_partition files in + + not has_partition + (* Use vfs-type to check for a filesystem of some sort of [device]. * Returns [Some [device, vfs_type; ...]] if found (there may be * multiple devices found in the case of btrfs), else [None] if nothing -- 2.17.0