Merge pull request #392 from truenas/NAS-141170

NAS-141170 / 25.10.4 / Revert "Add handling for STATX_CHANGE_COOKIE (#343)"

Author: yocalebo

module/os/linux/zfs/zfs_vnops_os.c

@@ -2613,19 +2613,8 @@ zfs_setattr(znode_t *zp, vattr_t *vap, int flags, cred_t *cr, zidmap_t *mnt_ns)
 	if (fuid_dirtied)
 		zfs_fuid_sync(zfsvfs, tx);
 
-	if (mask != 0) {
+	if (mask != 0)
 		zfs_log_setattr(zilog, tx, TX_SETATTR, zp, vap, mask, fuidp);
-		/*
-		 * Ensure that the z_seq is always incremented on setattr
-		 * operation. This is required for change accounting for
-		 * NFS clients.
-		 *
-		 * ATTR_MODE already increments via zfs_acl_chmod_setattr.
-		 * ATTR_SIZE already increments via zfs_freesp.
-		 */
-		if (!(mask & (ATTR_MODE | ATTR_SIZE)))
-			zp->z_seq++;
-	}
 
 	mutex_exit(&zp->z_lock);
 	if (mask & (ATTR_UID|ATTR_GID|ATTR_MODE))

module/os/linux/zfs/zpl_inode.c

@@ -506,32 +506,6 @@ zpl_getattr_impl(const struct path *path, struct kstat *stat, u32 request_mask,
 	}
 #endif
 
-#ifdef STATX_CHANGE_COOKIE
-	if (request_mask & STATX_CHANGE_COOKIE) {
-		/*
-		 * knfsd uses the STATX_CHANGE_COOKIE to surface to clients
-		 * change_info4 data, which is used to implement NFS client
-		 * name caching (see RFC 8881 Section 10.8). This number
-		 * should always increase with changes and should not be
-		 * reused. We cannot simply present ctime here because
-		 * ZFS uses a coarse timer to set them, which may cause
-		 * clients to fail to detect changes and invalidate cache.
-		 *
-		 * ZFS always increments znode z_seq number, but this is
-		 * uint_t and so we mask in ctime to upper bits.
-		 *
-		 * STATX_ATTR_CHANGE_MONOTONIC is advertised
-		 * to prevent knfsd from generating the change cookie
-		 * based on ctime. C.f. nfsd4_change_attribute in
-		 * fs/nfsd/nfsfh.c.
-		 */
-		stat->change_cookie =
-		    ((u64)stat->ctime.tv_sec << 32) | zp->z_seq;
-		stat->attributes |= STATX_ATTR_CHANGE_MONOTONIC;
-		stat->result_mask |= STATX_CHANGE_COOKIE;
-	}
-#endif
-
 #ifdef STATX_DIOALIGN
 	if (request_mask & STATX_DIOALIGN) {
 		uint64_t align;