CIFS: Make cifs_push_locks send as many locks at once as possible

that reduces a traffic and increases a performance.
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>

fs/cifs/file.c

@@ -829,6 +829,11 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
 	struct cifsLockInfo *li, *tmp;
 	struct cifs_tcon *tcon;
 	struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
+	unsigned int num, max_num;
+	LOCKING_ANDX_RANGE *buf, *cur;
+	int types[] = {LOCKING_ANDX_LARGE_FILES,
+		       LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
+	int i;
 
 	xid = GetXid();
 	tcon = tlink_tcon(cfile->tlink);
@@ -840,17 +845,49 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
 		return rc;
 	}
 
+	max_num = (tcon->ses->server->maxBuf - sizeof(struct smb_hdr)) /
+		  sizeof(LOCKING_ANDX_RANGE);
+	buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
+	if (!buf) {
+		mutex_unlock(&cinode->lock_mutex);
+		FreeXid(xid);
+		return rc;
+	}
+
+	for (i = 0; i < 2; i++) {
+		cur = buf;
+		num = 0;
 		list_for_each_entry_safe(li, tmp, &cinode->llist, llist) {
-		stored_rc = CIFSSMBLock(xid, tcon, cfile->netfid,
-					li->pid, li->length, li->offset,
-					0, 1, li->type, 0, 0);
+			if (li->type != types[i])
+				continue;
+			cur->Pid = cpu_to_le16(li->pid);
+			cur->LengthLow = cpu_to_le32((u32)li->length);
+			cur->LengthHigh = cpu_to_le32((u32)(li->length>>32));
+			cur->OffsetLow = cpu_to_le32((u32)li->offset);
+			cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32));
+			if (++num == max_num) {
+				stored_rc = cifs_lockv(xid, tcon, cfile->netfid,
+						       li->type, 0, num, buf);
+				if (stored_rc)
+					rc = stored_rc;
+				cur = buf;
+				num = 0;
+			} else
+				cur++;
+		}
+
+		if (num) {
+			stored_rc = cifs_lockv(xid, tcon, cfile->netfid,
+					       types[i], 0, num, buf);
 			if (stored_rc)
 				rc = stored_rc;
 		}
+	}
 
 	cinode->can_cache_brlcks = false;
 	mutex_unlock(&cinode->lock_mutex);
 
+	kfree(buf);
 	FreeXid(xid);
 	return rc;
 }