nfsd: clean up mounted_on_fileid handling

We only need the inode number for this, not a full rack of attributes.
Rename this function make it take a pointer to a u64 instead of
struct kstat, and change it to just request STATX_INO.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
[ cel: renamed get_mounted_on_ino() ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 09519b4..30d4897 100644 (file)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2769,9 +2769,10 @@ static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *bmval2, u32
 }
 
 
-static int get_parent_attributes(struct svc_export *exp, struct kstat *stat)
+static int nfsd4_get_mounted_on_ino(struct svc_export *exp, u64 *pino)
 {
        struct path path = exp->ex_path;
+       struct kstat stat;
        int err;
 
        path_get(&path);
@@ -2779,8 +2780,10 @@ static int get_parent_attributes(struct svc_export *exp, struct kstat *stat)
                if (path.dentry != path.mnt->mnt_root)
                        break;
        }
-       err = vfs_getattr(&path, stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
+       err = vfs_getattr(&path, &stat, STATX_INO, AT_STATX_SYNC_AS_STAT);
        path_put(&path);
+       if (!err)
+               *pino = stat.ino;
        return err;
 }
 
@@ -3277,22 +3280,21 @@ out_acl:
                *p++ = cpu_to_be32(stat.btime.tv_nsec);
        }
        if (bmval1 & FATTR4_WORD1_MOUNTED_ON_FILEID) {
-               struct kstat parent_stat;
                u64 ino = stat.ino;
 
                p = xdr_reserve_space(xdr, 8);
                if (!p)
                        goto out_resource;
                /*
-                * Get parent's attributes if not ignoring crossmount
-                * and this is the root of a cross-mounted filesystem.
+                * Get ino of mountpoint in parent filesystem, if not ignoring
+                * crossmount and this is the root of a cross-mounted
+                * filesystem.
                 */
                if (ignore_crossmnt == 0 &&
                    dentry == exp->ex_path.mnt->mnt_root) {
-                       err = get_parent_attributes(exp, &parent_stat);
+                       err = nfsd4_get_mounted_on_ino(exp, &ino);
                        if (err)
                                goto out_nfserr;
-                       ino = parent_stat.ino;
                }
                p = xdr_encode_hyper(p, ino);
        }