nfsd4: clean up downgrading code

In response to some review comments, get rid of the somewhat obscure
for-loop with bitops, and improve a comment.

Reported-by: Steve Dickson <steved@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 13f6f9f5ceec..22b065a55ea0 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -403,9 +403,11 @@ struct nfs4_file {
         /* One each for O_RDONLY, O_WRONLY, O_RDWR: */
         struct file *           fi_fds[3];
         /*
-         * Each open or lock stateid contributes 1 to either
-         * fi_access[O_RDONLY], fi_access[O_WRONLY], or both, depending
-         * on open or lock mode:
+         * Each open or lock stateid contributes 0-4 to the counts
+         * below depending on which bits are set in st_access_bitmap:
+         *     1 to fi_access[O_RDONLY] if NFS4_SHARE_ACCES_READ is set
+         *   + 1 to fi_access[O_WRONLY] if NFS4_SHARE_ACCESS_WRITE is set
+         *   + 1 to both of the above if NFS4_SHARE_ACCESS_BOTH is set.
          */
         atomic_t                fi_access[2];
         struct file             *fi_deleg_file;