Hello Christophe, (this set is based on 1cb704b2 plus those recent patches that have been positively reviewed, see https://github.com/openSUSE/multipath-tools/commits/upstream-queue). This patch set implements a new, improved path detection logic based on the previous discussions in the dm-devel threads "Multipath path classification revisited" and "RFC: multipath path classification", as well as Ben's review of v2 of this series. Up to 08/20, this series is the same as v2. Patch 11/20ff are substantially changed from v2. I left out the log level changes I'd included in the v2 series, they will be submitted as a separate series later. The ideas of this patch set are: 1. Avoid boot failures due to "blocked" devices, in particular setting SYSTEMD_READY=0 for path devices while multipathd can't setup maps for some reason. To this end, a means to indicate mapping failure has been added in patch 9-10. This was not in the RFC series. In contrast the v2 series, failure is not considered permanent; multipath and multipathd retry to setup the map under normal operations. Only "multipath -u/-c" checks and honors the failed flag always. 2. Try to be as consistent as possible between udev rule processing (multipath -u) and multipathd. Patch 1-4 contain the necessary logic fixes. That alone doesn't fully avoid inconsistencies because udev rule processing and multipathd processing occur at different points in time. Therefore, Logic to retrigger uevents if multipathd detects inconsistencies has been added in patch 5 and 6. 3. Disallow combinations of options that are dangerous or inconsistent, and generally simplify configuration. This is done by merging "find_multipaths", "multipath -i", and "multipathd -n" into a multi-value "find_multipaths" option in patch 7. This was not in the RFC series. 4. Try to a achieve "it just works" autodetection, I've called it "smart". This requires waiting for siblings, which necessarily inflicts a certain delay on initial set-up (boot). To meet the criticism raised on the RFC series, I've tried to minimize these delays, in particular for the common "local SATA root" case. This is implemented in patch 11-20, implementation details have changed wrt the RFC series. 5. Don't break compatibility with default setups of major distros. The semantics of "find_multipaths yes" and "find_multipaths no" was preserved for backwards compatibility (see commit message of patch 7 for details). A side effect of this patch set is that the user visible output of "multipath -u" and "multipath -c" has been changed to udev-friendly KEY="value" format. Also, with v5 of the set, the exit status of "multipath -u" is 0 even if the path is not a multipath member, in order to make udev happy. Changes v4->v5: - rebased on top of latest reviewed patches, see above - numbering v4->v5: 17->20, 18->18, 19->21, 20->22 - whitespace and other style fixes in 05/22, 06/22, 07/22, 09/22, 15/22, 16/22, 18/22 (checkpatch.pl; I took the freedom to keep Ben's reviewed-by tags). - 07/22: fixed error I made in v4 while rebasing to latest upstream - 15/22: fixed a compilation warning regarding "const" - 16/22: symbolic return code in find_multipaths_check_timeout (Ben) - 16/22: add udev rule to remove timeout marker on remove uevent (Ben) - 17/22: NEW, make "multipath -u" logic a bit simpler to read - 19/22: NEW, avoid returning "maybe" or "yes" after "no" (Ben) - 20/22: by virtue of 19/22, the O_EXCL test is never run after a device has been been released to systemd. This was Ben's main concern for v4. Only 16, 17, 19, 20 are lacking Reviewed-by: tags now. This series is also available here: https://github.com/mwilck/multipath-tools/commits/path-detection-v5 A broken-out version showing the FIX patches v4->v5 is here: https://github.com/mwilck/multipath-tools/commits/path-detection-v4_v5 Changes v3->v4: - Rebased onto latest upstream, commit 1cb704b - 07/20: changed macro names to ignore_wwids_on, ignore_new_devs_on to avoid ambiguity with variable names Changes v2->v3: Almost all of these are direct or indirect outcomes of Ben Marzinski's review of the v2 series. Kudos to Ben for the excellent review! - 09/20: use symbolic return codes for the helper functions for map failure - 09/20: use pthread_once() for path initialization - 11/20: added one more common code path invocation I'd forgotten in v2. - 13/20 "multipath -u: treat failed wwids as invalid" replaces v2 11/20 "don't try to setup failed wwids again" (we do try now, just not in "multipath -u"). - 16/20 and 19-20/20 change the way the udev rules communicate with multipath -u. In contrast to v2, we directly calculate the expiry time in "multipath -u" itself now, saving several callouts in the udev rules. Moreover, we remember the timeouts as timestamps under /dev/shm, allowing to pass this information across pivot-root. - 17/20 introduces a test if a path is busy, addressing Ben's valid concern that a file system mounted on a path device in the initrd might be unmounted because rules setting SYSTEMD_READY=0 on the device, permanently or temporarily. - 18/20 is an new addition, a speed-up for some cases where multipath -u would otherwise need to scan all paths and dm maps. - In 20/20, added the code path to multipath.rules for cancelling a running systemd timer and thus avoiding a spurious "add" event. - dropped v2 18/20-20/20. Patch 1-8 and 12, 14, 15, 19 are identical or only minimally modified wrt their counterparts in v2 (numbering changed from 11 on, though). Changes RFC->v2 not described above: - 03/17 "should_multipath: keep existing maps": don't check for empty pathvec; rather check if the mapping actually exists in device-mapper (Ben Marzinski) Regards, Martin Benjamin Marzinski (1): libmultipath: trigger change uevent on new device creation Martin Wilck (21): Revert "multipath: ignore -i if find_multipaths is set" Revert "multipathd: imply -n if find_multipaths is set" libmultipath: should_multipath: keep existing maps multipath -u -i: respect entries in WWIDs file libmultipath: trigger path uevent only when necessary libmultipath: change find_multipaths option to multi-value libmultipath: use const char* in open_file() libmultipath: functions to indicate mapping failure in /dev/shm libmultipath: indicate wwid failure in dm_addmap_create() multipath -u: common code path for result message multipath -u: change output to environment/key format multipath -u: treat failed wwids as invalid multipath -u: add DM_MULTIPATH_DEVICE_PATH=2 for "maybe" libmultipath: implement find_multipaths_timeout multipath -u : set FIND_MULTIPATHS_WAIT_UNTIL from /dev/shm multipath -u: cleanup logic multipath -u: quick check if path is multipathed multipath -u: don't grab devices already passed to system multipath -u: test if path is busy libmultipath: enable find_multipaths "smart" multipath.rules: find_multipaths "smart" logic libmultipath/config.h | 3 +- libmultipath/configure.c | 70 ++++++++++- libmultipath/configure.h | 1 + libmultipath/defaults.h | 5 +- libmultipath/devmapper.c | 9 +- libmultipath/dict.c | 55 ++++++++- libmultipath/file.c | 8 +- libmultipath/file.h | 3 +- libmultipath/propsel.c | 25 ++++ libmultipath/propsel.h | 1 + libmultipath/structs.h | 28 +++++ libmultipath/sysfs.c | 66 ++++++++++ libmultipath/sysfs.h | 2 + libmultipath/wwids.c | 128 ++++++++++++++++++- libmultipath/wwids.h | 13 +- multipath/main.c | 297 ++++++++++++++++++++++++++++++++++++++++----- multipath/multipath.8 | 9 +- multipath/multipath.conf.5 | 79 ++++++++---- multipath/multipath.rules | 70 ++++++++++- multipathd/main.c | 15 +-- multipathd/multipathd.8 | 8 +- 21 files changed, 802 insertions(+), 93 deletions(-) -- 2.16.1 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
