nfsd: clarify readdir/mountpoint-crossing code
The code here is difficult to understand; attempt to clarify somewhat by
pulling out one of the more mystifying conditionals into a separate
function.
While we're here, also add lease_time to the list of attributes that we
don't really need to cross a mountpoint to fetch.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Peter Staubach <staubach@redhat.com>
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 0e6a179..1ba7ad9 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1867,6 +1867,15 @@
goto out;
}
+static inline int attributes_need_mount(u32 *bmval)
+{
+ if (bmval[0] & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_LEASE_TIME))
+ return 1;
+ if (bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID)
+ return 1;
+ return 0;
+}
+
static __be32
nfsd4_encode_dirent_fattr(struct nfsd4_readdir *cd,
const char *name, int namlen, __be32 *p, int *buflen)
@@ -1888,9 +1897,7 @@
* we will not follow the cross mount and will fill the attribtutes
* directly from the mountpoint dentry.
*/
- if (d_mountpoint(dentry) &&
- (cd->rd_bmval[0] & ~FATTR4_WORD0_RDATTR_ERROR) == 0 &&
- (cd->rd_bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID) == 0)
+ if (d_mountpoint(dentry) && !attributes_need_mount(cd->rd_bmval))
ignore_crossmnt = 1;
else if (d_mountpoint(dentry)) {
int err;