Commit c74dfe97 authored by Trond Myklebust's avatar Trond Myklebust Committed by Anna Schumaker
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NFS: Add mount option 'softreval' 



Add a mount option 'softreval' that allows attribute revalidation 'getattr'
calls to time out, and causes them to fall back to using the cached
attributes.
The use case for this option is for ensuring that we can still (slowly)
traverse paths and use cached information even when the server is down.
Once the server comes back up again, the getattr calls start succeeding,
and the caches will revalidate as usual.

The 'softreval' mount option is automatically enabled if you have
specified 'softerr'.  It can be turned off using the options
'nosoftreval', or 'hard'.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 5c965db8

fs/nfs/fs_context.c

+12 −2
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ enum nfs_param { 
	Opt_sloppy,

	Opt_soft,

	Opt_softerr,

	Opt_softreval,

	Opt_source,

	Opt_tcp,

	Opt_timeo,
@@ -128,6 +129,7 @@ static const struct fs_parameter_spec nfs_param_specs[] = { 
	fsparam_flag  ("sloppy",	Opt_sloppy),

	fsparam_flag  ("soft",		Opt_soft),

	fsparam_flag  ("softerr",	Opt_softerr),

	fsparam_flag  ("softreval",	Opt_softreval),

	fsparam_string("source",	Opt_source),

	fsparam_flag  ("tcp",		Opt_tcp),

	fsparam_u32   ("timeo",		Opt_timeo),
@@ -460,11 +462,19 @@ static int nfs_fs_context_parse_param(struct fs_context *fc, 
		ctx->flags &= ~NFS_MOUNT_SOFTERR;

		break;

	case Opt_softerr:

		ctx->flags |= NFS_MOUNT_SOFTERR;

		ctx->flags |= NFS_MOUNT_SOFTERR | NFS_MOUNT_SOFTREVAL;

		ctx->flags &= ~NFS_MOUNT_SOFT;

		break;

	case Opt_hard:

		ctx->flags &= ~(NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR);

		ctx->flags &= ~(NFS_MOUNT_SOFT |

				NFS_MOUNT_SOFTERR |

				NFS_MOUNT_SOFTREVAL);

		break;

	case Opt_softreval:

		if (result.negated)

			ctx->flags &= ~NFS_MOUNT_SOFTREVAL;

		else

			ctx->flags &= NFS_MOUNT_SOFTREVAL;

		break;

	case Opt_posix:

		if (result.negated)

fs/nfs/inode.c

+7 −1
Original line number Diff line number Diff line
@@ -1156,7 +1156,13 @@ __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode) 
		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) getattr failed, error=%d\n",

			 inode->i_sb->s_id,

			 (unsigned long long)NFS_FILEID(inode), status);

		if (status == -ESTALE) {

		switch (status) {

		case -ETIMEDOUT:

			/* A soft timeout occurred. Use cached information? */

			if (server->flags & NFS_MOUNT_SOFTREVAL)

				status = 0;

			break;

		case -ESTALE:

			nfs_zap_caches(inode);

			if (!S_ISDIR(inode->i_mode))

				set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);

fs/nfs/nfs3proc.c

+6 −1
Original line number Diff line number Diff line
@@ -110,10 +110,15 @@ nfs3_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle, 
		.rpc_resp	= fattr,

	};

	int	status;

	unsigned short task_flags = 0;



	/* Is this is an attribute revalidation, subject to softreval? */

	if (inode && (server->flags & NFS_MOUNT_SOFTREVAL))

		task_flags |= RPC_TASK_TIMEOUT;



	dprintk("NFS call  getattr\n");

	nfs_fattr_init(fattr);

	status = rpc_call_sync(server->client, &msg, 0);

	status = rpc_call_sync(server->client, &msg, task_flags);

	dprintk("NFS reply getattr: %d\n", status);

	return status;

}

fs/nfs/nfs4proc.c

+26 −7
Original line number Diff line number Diff line
@@ -1097,11 +1097,12 @@ static int nfs4_call_sync_custom(struct rpc_task_setup *task_setup) 
	return ret;

}



static int nfs4_call_sync_sequence(struct rpc_clnt *clnt,

static int nfs4_do_call_sync(struct rpc_clnt *clnt,

			     struct nfs_server *server,

			     struct rpc_message *msg,

			     struct nfs4_sequence_args *args,

				   struct nfs4_sequence_res *res)

			     struct nfs4_sequence_res *res,

			     unsigned short task_flags)

{

	struct nfs_client *clp = server->nfs_client;

	struct nfs4_call_sync_data data = {
@@ -1113,12 +1114,23 @@ static int nfs4_call_sync_sequence(struct rpc_clnt *clnt, 
		.rpc_client = clnt,

		.rpc_message = msg,

		.callback_ops = clp->cl_mvops->call_sync_ops,

		.callback_data = &data

		.callback_data = &data,

		.flags = task_flags,

	};



	return nfs4_call_sync_custom(&task_setup);

}



static int nfs4_call_sync_sequence(struct rpc_clnt *clnt,

				   struct nfs_server *server,

				   struct rpc_message *msg,

				   struct nfs4_sequence_args *args,

				   struct nfs4_sequence_res *res)

{

	return nfs4_do_call_sync(clnt, server, msg, args, res, 0);

}





int nfs4_call_sync(struct rpc_clnt *clnt,

		   struct nfs_server *server,

		   struct rpc_message *msg,
@@ -4064,11 +4076,18 @@ static int _nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle, 
		.rpc_argp = &args,

		.rpc_resp = &res,

	};

	unsigned short task_flags = 0;



	/* Is this is an attribute revalidation, subject to softreval? */

	if (inode && (server->flags & NFS_MOUNT_SOFTREVAL))

		task_flags |= RPC_TASK_TIMEOUT;



	nfs4_bitmap_copy_adjust(bitmask, nfs4_bitmask(server, label), inode);



	nfs_fattr_init(fattr);

	return nfs4_call_sync(server->client, server, &msg, &args.seq_args, &res.seq_res, 0);

	nfs4_init_sequence(&args.seq_args, &res.seq_res, 0, 0);

	return nfs4_do_call_sync(server->client, server, &msg,

			&args.seq_args, &res.seq_res, task_flags);

}



int nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,

fs/nfs/proc.c

+6 −1
Original line number Diff line number Diff line
@@ -108,10 +108,15 @@ nfs_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle, 
		.rpc_resp	= fattr,

	};

	int	status;

	unsigned short task_flags = 0;



	/* Is this is an attribute revalidation, subject to softreval? */

	if (inode && (server->flags & NFS_MOUNT_SOFTREVAL))

		task_flags |= RPC_TASK_TIMEOUT;



	dprintk("NFS call  getattr\n");

	nfs_fattr_init(fattr);

	status = rpc_call_sync(server->client, &msg, 0);

	status = rpc_call_sync(server->client, &msg, task_flags);

	dprintk("NFS reply getattr: %d\n", status);

	return status;

}

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