On Sun, Sep 03, 2017 at 12:38:29AM +0200, Martin Wilck wrote: > The main part of this series is a cleanup of the udev rules for > multipath and kpartx. More about that further down. > > - patch 01 is an obvious bug fix > - patch 02-08 are fixes for kpartx problems that I encountered > during testing, with related tests. The interesting one here is > 04, which adds the ability to rename partition mappings if the > current name doesn't match the specified scheme. The purpose > is to provide consistent naming of partition mappings across > the OS, even in the presence of other tools such as parted > that may follow different conventions. > - 09-15 are changes to the core code I found necessary for the > udev rules cleanup, most importantly a helper to figure out > quickly whether a given multipath has usable paths > (multipath -U). This replaces the former SUSE-specific tests > for DM_DEPS and DM_TABLE_STATE. > - 16ff are the actual changes to the udev rules. This was motivated > by Ben Marzinski who asked Hannes and me a while ago to remove > the SUSE-isms in the rules files (patch 23), and cleanup mainly > kpartx.rules. > ACK for everything but: [PATCH 16/31] 11-dm-mpath.rules: multipath -U for READY check [PATCH 20/31] 11-dm-mpath.rules: don't set READY->ACTIVATION [PATCH 21/31] 11-dm-mpath.rules: Remember DM_ACTIVATION [PATCH 30/31] kpartx/del-part-nodes.rules: new udev file [PATCH 31/31] kpartx.rules: move symlink code to other files -Ben > More about the udev rules changes: > > Multipath maps are special because they can exist without any > usable members/paths, and users expect them to be at least partly > functional in such situations. Care has to be taken to avoid I/O > on maps that may not be able to process it, and not to loose any > symlinks that might be used by systemd to access the partition. > Partitions on multipath maps have similar semantics, with the added > difficulty that no first-hand information about the parent device > is available. A lot of the existing code was trying to fix these > corner case situations, but sometimes incorrectly or not cleanly. > I have pointed out the issues in the individual commit messages. > One important point is that checking DM_NR_VALID_PATHS>0 is not > in sufficient to affirm that I/O will succeed. That was the reason > for writing the "multipath -U" helper. > > Also, multipath maps receive frequent udev events that don't > matter to upper layers at all. In such cases, further scanning > should be avoided. This is implemented much more cleanly now, > I hope. > > Following the example of the dm core, I split the kpartx rules > up in "early" rules for setting properties and symlinks, and > "late" rules for taking actions such as running kpartx. I believe > that this makes the code better readable. > CAUTION: The new rules files matter for other packages such as dracut. > Distribution package builders have to be careful here. If this patch set > is accepted, respective patches will be send to the dracut maintainers. > > Following Ben's suggestions, a new rules file is added that > is responsible for deleting partition device nodes for multipath > member devices. > > I didn't expect this series to grow so large, but after having > worked and tested for considerable time, this is the first > version that I find ready for serious review. I smoke-tested the > interaction of rules files, multipathd, udev, systemd, and > kpartx quite a bit with failover and 0-paths scenarios, successfully. > > The changes are less drastic than the stats below suggest. > A considerable part just moves functionality out of existing code > into separate functions in order to use it elsewhere. > > Regards, > Martin > > Martin Wilck (31): > libmultipath: fix partition_delimiter config option > kpartx: helper functions for name and uuid generation > kpartx: search partitions by UUID, and rename > test-kpartx: add tests for renaming functionality > kpartx: fix a corner case when renaming partitions > kpartx: fix part deletion without partition table > test-kpartx: test deletion with empty part table > kpartx: only recognize dasd part table on DASD > libmultipath: support MPATH_UDEV_NO_PATHS_FLAG on map creation > libmultipath: add get_udev_device > libmultipath: get_refwwid: use get_udev_device > libmultipath: use const char* in some dm helpers > libmultipath: add DI_NOIO flag for pathinfo > libmultipath: add dm_get_multipath > multipath: implement "check usable paths" (-C/-U) > 11-dm-mpath.rules: multipath -U for READY check > 11-dm-mpath.rules: import more ID_FS_xxx vars from db > 11-dm-mpath.rules: no need to test before IMPORT > 11-dm-mpath.rules: handle new maps with READY==0 > 11-dm-mpath.rules: don't set READY->ACTIVATION > 11-dm-mpath.rules: Remember DM_ACTIVATION > multipath.rules: set ID_FS_TYPE to "mpath_member" > kpartx.rules: don't rely on DM_DEPS and DM_TABLE_STATE > kpartx.rules: respect DM_UDEV_LOW_PRIORITY_FLAG > kpartx.rules: improved logic for by-uuid and by-label links > kpartx.rules: create by-partuuid and by-partlabel symlinks > kpartx.rules: generate type-name links only for multipath devices > kpartx.rules: fix logic for adding partitions > multipath/kpartx rules: avoid superfluous scanning > kpartx/del-part-nodes.rules: new udev file > kpartx.rules: move symlink code to other files > > kpartx/Makefile | 2 + > kpartx/dasd.c | 3 + > kpartx/del-part-nodes.rules | 32 ++++++++ > kpartx/devmapper.c | 194 ++++++++++++++++++++++++++++++++++++++++++-- > kpartx/devmapper.h | 18 +++- > kpartx/dm-parts.rules | 39 +++++++++ > kpartx/kpartx.c | 105 +++++++----------------- > kpartx/kpartx.rules | 58 ++++++------- > kpartx/test-kpartx | 50 ++++++++++++ > libmultipath/config.h | 1 + > libmultipath/configure.c | 58 ++++++++++--- > libmultipath/configure.h | 1 + > libmultipath/devmapper.c | 87 ++++++++++++-------- > libmultipath/devmapper.h | 5 +- > libmultipath/discovery.c | 8 ++ > libmultipath/discovery.h | 2 + > multipath/11-dm-mpath.rules | 76 +++++++++++++---- > multipath/main.c | 90 +++++++++++++++++++- > multipath/multipath.8 | 13 ++- > multipath/multipath.rules | 2 +- > 20 files changed, 659 insertions(+), 185 deletions(-) > create mode 100644 kpartx/del-part-nodes.rules > create mode 100644 kpartx/dm-parts.rules > > -- > 2.14.0 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
