On Mon, 2025-12-15 at 15:29 -0500, Benjamin Marzinski wrote:
> When libmpathpersist notifies multipathd that a key has been
> registered,
> cli_setprstatus() calls pr_register_active_paths() with a flag to let
> it
> know that the paths are likely already registered, and it can skip
> re-registering them, as long as the number of active paths matches
> the
> number of registered keys. This shortcut can fail, causing multipathd
> to
> not register needed paths, if either a path becomes usable and
> another
> becomes unusable while libmpathpersist is running or if there already
> were registered keys for I_T Nexus's that don't correspond to path
> devices.
>
> To make this shortcut work in cases like that, this commit adds a new
> multipathd command "setprstatus map <map> pathlist <pathlist>", where
> <pathlist> is a quoted, whitespace separated list of scsi path
> devices.
> libmpathpersist will send out the list of paths it registered the key
> on. pr_register_active_paths() will skip calling
> mpath_pr_event_handle()
> for paths on that list.
>
> In order to deal with the possiblity of a preempt occuring while
> libmpathpersist was running, the code still needs to check that it
> has
> the expected number of keys.
>
> Fixes: f7d6cd17 ("multipathd: Fix race while registering PR key")
> Signed-off-by: Benjamin Marzinski <[email protected]>
Reviewed-by: Martin Wilck <[email protected]>
Git clang-format applied a few minor changes, and I needed to add
a spelling exception. I'll apply to my queue branch with these changes.
