On Mon, May 15, 2017 at 05:37:10PM +0200, Martin Wilck wrote: ACK for the set -Ben > 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 (08/12) although this series is otherwise focused only on kpartx. > Patch 04/12 would also have a libdevmapper equivalent, but I haven't > included it because it would conflict with Ben's previously posted > patch "libmultipath: fix partition detection". > > The patches are based on Christophe's tree; Christophe, if you prefer, > I can rebase them on top of Ben's late submissions. > > Feedback is welcome. > > Changes wrt v1: > - Test program (01/12): improved cleanup, and used "kpartx -s" rather than waiting. > - At Ben's suggestion, removed "no_partitions" support rather than fixing it. > - Previous 04/12 split into two patches (04+05/12), improving and separating > out the part that would similarly apply to libmultipath (see above). > - New UUID format in patch 09/12 since the previous one wasn't well-received; > the "-kpartx-" part was superfluous, as partition UUIDs start with "part%s-" anyway. > - Added the trivial fix 12/12. > > Martin Wilck (12): > kpartx: test-kpartx: new unit test program > kpartx: remove "no_partitions" support > kpartx: remove is_loop_device > kpartx: relax and improve UUID check in dm_compare_uuid > 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: include sys/sysmacros.h > > kpartx/devmapper.c | 80 ++++++--------- > kpartx/devmapper.h | 2 +- > kpartx/kpartx.c | 50 ++++++++-- > kpartx/lopart.c | 75 ++++++-------- > kpartx/lopart.h | 1 - > kpartx/sysmacros.h | 9 -- > kpartx/test-kpartx | 254 +++++++++++++++++++++++++++++++++++++++++++++++ > libmultipath/devmapper.c | 15 +-- > 8 files changed, 371 insertions(+), 115 deletions(-) > delete mode 100644 kpartx/sysmacros.h > create mode 100755 kpartx/test-kpartx > > -- > 2.12.2 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
