CVS commit: src/sys/dev/dkwedge

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Fri Apr 21 18:31:00 UTC 2023

Modified Files:
        src/sys/dev/dkwedge: dk.c

Log Message:
dk(4): Set .d_cfdriver and .d_devtounit to plug open/detach race.

This way, opening dkN or rdkN will wait if attach or detach is still
in progress, and vdevgone will wake up such pending opens and make
them fail.  So it is no longer possible for a wedge to be detached
after dkopen has already started using it.

For now, we use a custom .d_devtounit function that looks up the
autoconf unit number via the dkwedges array, which conceivably may
use an independent unit numbering system -- nothing guarantees they
match up.  (In practice they will mostly match up, but concurrent
wedge creation could lead to different numbering.)  Eventually this
should be changed so the two numbering systems match, which would let
us delete the new dkunit function and just use dev_minor_unit like
many other drivers can.


To generate a diff of this commit:
cvs rdiff -u -r1.143 -r1.144 src/sys/dev/dkwedge/dk.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.