On Sat, May 06, 2017 at 12:05:49AM +0200, Martin Wilck wrote: > Working on a bug report about kpartx not properly removing > partitions for loop devices, I realized a number of glitches > and improperly handled corner cases in the kpartx code for > deleting partitions. Some mappings are not deleted although > they should be, and others are deleted although that is clearly > wrong. > > This patch series fixes the issues I found. The series starts > with a test program demonstrating the problems. The program > succeeds only after all patches of this series are applied. > > Here is my summary of what I think how kpartx should behave: > > 1) kpartx should delete all mappings it created beforehand. > 2) kpartx should handle partitions on dm devices and other devices > (e.g. loop devices) equally well. > 3) kpartx should only delete "partitions", which are single-target > linear mappings into a block device. Other maps should not be touched. > 4) kpartx should only delete mappings it created itself beforehand. > In particular, it shouldn't delete LVM LVs, even if they are fully > contained in the block device at hand and thus look like partitions > in the first place. (For historical compatibility reasons, allow > such mappings to be deleted with the -f/--force flag). > 5) DM map names may be changed, thus kpartx shouldn't rely on them to > check whether a mapping is a partition of a particular device. It is > legal for a partition of /dev/loop0 to be named "loop0". > > One patch has an obvious libdevmapper equivalent and is therefore > included although this series is otherwise focused only on kpartx. ACK for the set (with the possible exception of "kpartx: avoid ioctl error for loop devices", if we don't need to keep the dm_no_partitions code anymore). -Ben > > Feedback is welcome. > > Martin Wilck (10): > kpartx: test-kpartx: new unit test program > kpartx: avoid ioctl error for loop devices > kpartx: remove is_loop_device > kpartx: dm_remove_partmaps: support non-dm devices > kpartx: dm_devn: return error for non-existent device > kpartx: don't treat multi-linear mappings as partitions > libmultipath: don't treat multi-linear mappings as partitions > kpartx: use partition UUID for non-DM devices > kpartx: use absolute path for regular files > kpartx: find_loop_by_file: use sysfs > > kpartx/devmapper.c | 39 +++++--- > kpartx/devmapper.h | 2 +- > kpartx/kpartx.c | 42 +++++++- > kpartx/lopart.c | 73 ++++++-------- > kpartx/lopart.h | 1 - > kpartx/test-kpartx | 253 +++++++++++++++++++++++++++++++++++++++++++++++ > libmultipath/devmapper.c | 15 +-- > 7 files changed, 356 insertions(+), 69 deletions(-) > create mode 100755 kpartx/test-kpartx > > -- > 2.12.2 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
