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>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 8e253a3..683885b 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3523,16 +3523,29 @@
return status;
}
-static inline void nfs4_file_downgrade(struct nfs4_ol_stateid *stp, unsigned int to_access)
+static inline void nfs4_stateid_downgrade_bit(struct nfs4_ol_stateid *stp, u32 access)
{
- int i;
+ if (!test_bit(access, &stp->st_access_bmap))
+ return;
+ nfs4_file_put_access(stp->st_file, nfs4_access_to_omode(access));
+ __clear_bit(access, &stp->st_access_bmap);
+}
- for (i = 1; i < 4; i++) {
- if (test_bit(i, &stp->st_access_bmap)
- && ((i & to_access) != i)) {
- nfs4_file_put_access(stp->st_file, nfs4_access_to_omode(i));
- __clear_bit(i, &stp->st_access_bmap);
- }
+static inline void nfs4_stateid_downgrade(struct nfs4_ol_stateid *stp, u32 to_access)
+{
+ switch (to_access) {
+ case NFS4_SHARE_ACCESS_READ:
+ nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_WRITE);
+ nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_BOTH);
+ break;
+ case NFS4_SHARE_ACCESS_WRITE:
+ nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_READ);
+ nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_BOTH);
+ break;
+ case NFS4_SHARE_ACCESS_BOTH:
+ break;
+ default:
+ BUG();
}
}
@@ -3578,7 +3591,7 @@
stp->st_deny_bmap, od->od_share_deny);
goto out;
}
- nfs4_file_downgrade(stp, od->od_share_access);
+ nfs4_stateid_downgrade(stp, od->od_share_access);
reset_union_bmap_deny(od->od_share_deny, &stp->st_deny_bmap);