nfsd: shrink st_access_bmap and st_deny_bmap

We never use anything above bit #3, so an unsigned long for each is
wasteful. Shrink them to a char each, and add some WARN_ON_ONCE calls if
we try to set or clear bits that would go outside those sizes.

Note too that because atomic bitops work on unsigned longs, we have to
abandon their use here. That shouldn't be a problem though since we
don't really care about the atomicity in this code anyway. Using them
was just a convenient way to flip bits.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 9f1159d..72aee4b 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -406,8 +406,8 @@ struct nfs4_ol_stateid {
 	struct list_head              st_locks;
 	struct nfs4_stateowner      * st_stateowner;
 	struct nfs4_file            * st_file;
-	unsigned long                 st_access_bmap;
-	unsigned long                 st_deny_bmap;
+	unsigned char                 st_access_bmap;
+	unsigned char                 st_deny_bmap;
 	struct nfs4_ol_stateid         * st_openstp;
 };