afs: Adjust the fileserver rotation algorithm to reprobe/retry more quickly (8409f67b) · Commits · 戴 / test

fs/afs/fs_probe.c

+47 −0

Original line number	Diff line number	Diff line
		@@ -338,6 +338,18 @@ static void afs_dispatch_fs_probe(struct afs_net net, struct afs_server server
		afs_put_server(net, server, afs_server_trace_put_probe);
		}

		/*
		* Probe a server immediately without waiting for its due time to come
		* round. This is used when all of the addresses have been tried.
		*/
		void afs_probe_fileserver(struct afs_net net, struct afs_server server)
		{
		write_seqlock(&net->fs_lock);
		if (!list_empty(&server->probe_link))
		return afs_dispatch_fs_probe(net, server, true);
		write_sequnlock(&net->fs_lock);
		}

		/*
		* Probe dispatcher to regularly dispatch probes to keep NAT alive.
		*/
		@@ -411,3 +423,38 @@ again:
		_leave(" [quiesce]");
		}
		}

		/*
		* Wait for a probe on a particular fileserver to complete for 2s.
		*/
		int afs_wait_for_one_fs_probe(struct afs_server *server, bool is_intr)
		{
		struct wait_queue_entry wait;
		unsigned long timo = 2 * HZ;

		if (atomic_read(&server->probe_outstanding) == 0)
		goto dont_wait;

		init_wait_entry(&wait, 0);
		for (;;) {
		prepare_to_wait_event(&server->probe_wq, &wait,
		is_intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
		if (timo == 0 \|\|
		server->probe.responded \|\|
		atomic_read(&server->probe_outstanding) == 0 \|\|
		(is_intr && signal_pending(current)))
		break;
		timo = schedule_timeout(timo);
		}

		finish_wait(&server->probe_wq, &wait);

		dont_wait:
		if (server->probe.responded)
		return 0;
		if (is_intr && signal_pending(current))
		return -ERESTARTSYS;
		if (timo == 0)
		return -ETIME;
		return -EDESTADDRREQ;
		}

+14 −10

Original line number	Diff line number	Diff line
		@@ -836,6 +836,8 @@ struct afs_operation {
		#define AFS_OPERATION_DOWNGRADE 0x0080 /* Set to retry with downgraded opcode */
		#define AFS_OPERATION_LOCK_0 0x0100 /* Set if have io_lock on file[0] */
		#define AFS_OPERATION_LOCK_1 0x0200 /* Set if have io_lock on file[1] */
		#define AFS_OPERATION_TRIED_ALL 0x0400 /* Set if we've tried all the fileservers */
		#define AFS_OPERATION_RETRY_SERVER 0x0800 /* Set if we should retry the current server */
		};

		/*
		@@ -1055,7 +1057,9 @@ static inline void afs_op_set_fid(struct afs_operation *op, unsigned int n,
		extern void afs_fileserver_probe_result(struct afs_call *);
		extern void afs_fs_probe_fileserver(struct afs_net , struct afs_server , struct key *, bool);
		extern int afs_wait_for_fs_probes(struct afs_server_list *, unsigned long);
		extern void afs_probe_fileserver(struct afs_net , struct afs_server );
		extern void afs_fs_probe_dispatcher(struct work_struct *);
		extern int afs_wait_for_one_fs_probe(struct afs_server *, bool);

		/*
		* inode.c

+27 −2

Original line number	Diff line number	Diff line
		@@ -369,6 +369,7 @@ selected_server:

		_debug("USING SERVER: %pU", &server->uuid);

		op->flags \|= AFS_OPERATION_RETRY_SERVER;
		op->server = server;
		if (vnode->cb_server != server) {
		vnode->cb_server = server;
		@@ -383,6 +384,7 @@ selected_server:
		afs_get_addrlist(alist);
		read_unlock(&server->fs_lock);

		retry_server:
		memset(&op->ac, 0, sizeof(op->ac));

		if (!op->ac.alist)
		@@ -398,13 +400,36 @@ iterate_address:
		* address on which it will respond to us.
		*/
		if (!afs_iterate_addresses(&op->ac))
		goto next_server;
		goto out_of_addresses;

		_debug("address [%u] %u/%u", op->index, op->ac.index, op->ac.alist->nr_addrs);
		_debug("address [%u] %u/%u %pISp",
		op->index, op->ac.index, op->ac.alist->nr_addrs,
		&op->ac.alist->addrs[op->ac.index].transport);

		_leave(" = t");
		return true;

		out_of_addresses:
		/* We've now had a failure to respond on all of a server's addresses -
		* immediately probe them again and consider retrying the server.
		*/
		afs_probe_fileserver(op->net, op->server);
		if (op->flags & AFS_OPERATION_RETRY_SERVER) {
		alist = op->ac.alist;
		error = afs_wait_for_one_fs_probe(
		op->server, !(op->flags & AFS_OPERATION_UNINTR));
		switch (error) {
		case 0:
		op->flags &= ~AFS_OPERATION_RETRY_SERVER;
		goto retry_server;
		case -ERESTARTSYS:
		goto failed_set_error;
		case -ETIME:
		case -EDESTADDRREQ:
		goto next_server;
		}
		}

		next_server:
		_debug("next");
		afs_end_cursor(&op->ac);