CVS commit: src/sys/miscfs/specfs

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

Module Name:    src
Committed By:   riastradh
Date:           Mon Mar 28 12:37:01 UTC 2022

Modified Files:
        src/sys/miscfs/specfs: spec_vnops.c

Log Message:
specfs: Take an I/O reference in spec_node_setmountedfs.

This is not quite correct.  We _should_ require the caller to hold a
vnode lock around spec_node_getmountedfs, and an exclusive vnode lock
around spec_node_setmountedfs, so that it is only necessary to check
whether revoke has already happened, not hold an I/O reference.

Unfortunately, various callers in various file systems don't follow
this sensible rule.  So let's at least make sure the vnode can't be
revoked in spec_node_setmountedfs, while we're in bdev_ioctl, and
leave a comment explaining what the sorry state of affairs is and how
to fix it later.


To generate a diff of this commit:
cvs rdiff -u -r1.202 -r1.203 src/sys/miscfs/specfs/spec_vnops.c

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