[dm-devel] [PATCH v2 0/8] multipath-tools: no_path_retry/queue_if_no_path logic

[Benjamin Marzinski]

On Tue, Jun 20, 2017 at 01:46:06PM +0200, Martin Wilck wrote:
> This patch set attempts to sanitize the logic used for consistently handling
> options that can be set both via the "features" string and explicit multipath.conf
> options. This is most prominently "no_path_retry" vs. "queue_if_no_path", but also
> "retain_attached_hw_handler" vs. the feature of the same name.
> 
> The logic this patch set follows is:
>  - If "no_path_retry" is set to any value, "queue_if_no_path" is ignored
>    (this is the case nowadays for almost all "real" storage arrays, thanks to hwtable).
>  - Otherwise, if "queue_if_no_path" is set, treat it like "no_path_retry queue".
> 
> ... likewise for "retain_attached_hw_handler".
> 
> In the long run, we should get rid of the "features" settings duplicating
> configuration options altogether; the patch set prepares this by printing
> warning messages.
> 
> The logic is implemented in the new function reconcile_features_with_options,
> which is called from both select_features() and merge_hwe(). In setup_map(),
> we need to call select_features() after select_no_path_retry() to make this work.
> The actual feature setting for device-mapper is made in assemble_map(), the
> patch set also fixes the logic there.
> 
> The patch set documents the behavior in the man page, and adds some more
> man page fixes.
> 
> Finally, by skipping superfluous default initializations in load_config(), the
> log messages for the respective config settings become more appropriate.
> 
> Review and comments are highly welcome.

ACK for the set

-Ben

> 
> Changes wrt v1:
>   - Suggestions from Ben Marzinski:
>     * Made sure "multipathd show config" still works (1/8).
>     * Fixed logging for default setting of "max_sectors" (1/8)
>     * Consistent internal treatment of mp->features (3/8, 4/8)
>     * Fixed whitespace error (6/8)
>     * Added deprecated warnings (8/8)
>   - Made sure the same logic is used in propsel.c and config.c by
>     calling the same function (3/8, 4/8)
>   - Added deprecated warnings (8/8)
> 
> Martin Wilck (8):
>   libmultipath: load_config: skip setting unnecessary defaults
>   libmultipath: add/remove_feature: use const char* for feature
>   libmultipath: clarify option conflicts for "features"
>   libmultipath: merge_hwe: fix queue_if_no_path logic
>   libmultipath: assemble_map: fix queue_if_no_path logic
>   multipath.conf.5: document no_path_retry vs. queue_if_no_path
>   multipath.conf.5: Remove ??? and other minor fixes
>   libmultipath: add deprecated warning for some features settings
> 
>  libmultipath/config.c      | 36 +++++++--------------
>  libmultipath/configure.c   |  4 +--
>  libmultipath/dict.c        | 11 ++++---
>  libmultipath/dmparser.c    |  5 ++-
>  libmultipath/propsel.c     | 79 +++++++++++++++++++++++++++++++++++++---------
>  libmultipath/propsel.h     |  3 ++
>  libmultipath/structs.c     | 30 ++++++++++--------
>  libmultipath/structs.h     |  4 +--
>  multipath/multipath.conf.5 | 52 ++++++++++++++++--------------
>  9 files changed, 136 insertions(+), 88 deletions(-)
> 
> -- 
> 2.13.1