Commit 01cbf385 authored by Trond Myklebust's avatar Trond Myklebust Committed by Chuck Lever
Browse files

nfsd: Set PF_LOCAL_THROTTLE on local filesystems only 



Don't set PF_LOCAL_THROTTLE on remote filesystems like NFS, since they
aren't expected to ever be subject to double buffering.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 2e19d10c

fs/nfs/export.c

+2 −1
Original line number Diff line number Diff line
@@ -171,5 +171,6 @@ const struct export_operations nfs_export_ops = { 
	.encode_fh = nfs_encode_fh,

	.fh_to_dentry = nfs_fh_to_dentry,

	.get_parent = nfs_get_parent,

	.flags = EXPORT_OP_NOWCC|EXPORT_OP_NOSUBTREECHK|EXPORT_OP_CLOSE_BEFORE_UNLINK,

	.flags = EXPORT_OP_NOWCC|EXPORT_OP_NOSUBTREECHK|

		EXPORT_OP_CLOSE_BEFORE_UNLINK|EXPORT_OP_REMOTE_FS,

};

fs/nfsd/vfs.c

+11 −2
Original line number Diff line number Diff line
@@ -978,18 +978,25 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, 
				__be32 *verf)

{

	struct file		*file = nf->nf_file;

	struct super_block	*sb = file_inode(file)->i_sb;

	struct svc_export	*exp;

	struct iov_iter		iter;

	__be32			nfserr;

	int			host_err;

	int			use_wgather;

	loff_t			pos = offset;

	unsigned long		exp_op_flags = 0;

	unsigned int		pflags = current->flags;

	rwf_t			flags = 0;

	bool			restore_flags = false;



	trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);



	if (test_bit(RQ_LOCAL, &rqstp->rq_flags))

	if (sb->s_export_op)

		exp_op_flags = sb->s_export_op->flags;



	if (test_bit(RQ_LOCAL, &rqstp->rq_flags) &&

	    !(exp_op_flags & EXPORT_OP_REMOTE_FS)) {

		/*

		 * We want throttling in balance_dirty_pages()

		 * and shrink_inactive_list() to only consider
@@ -998,6 +1005,8 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, 
		 * the client's dirty pages or its congested queue.

		 */

		current->flags |= PF_LOCAL_THROTTLE;

		restore_flags = true;

	}



	exp = fhp->fh_export;

	use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
@@ -1049,7 +1058,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, 
		trace_nfsd_write_err(rqstp, fhp, offset, host_err);

		nfserr = nfserrno(host_err);

	}

	if (test_bit(RQ_LOCAL, &rqstp->rq_flags))

	if (restore_flags)

		current_restore_flags(pflags, PF_LOCAL_THROTTLE);

	return nfserr;

}

include/linux/exportfs.h

+1 −0
Original line number Diff line number Diff line
@@ -216,6 +216,7 @@ struct export_operations { 
#define	EXPORT_OP_NOWCC			(0x1) /* don't collect v3 wcc data */

#define	EXPORT_OP_NOSUBTREECHK		(0x2) /* no subtree checking */

#define	EXPORT_OP_CLOSE_BEFORE_UNLINK	(0x4) /* close files before unlink */

#define EXPORT_OP_REMOTE_FS		(0x8) /* Filesystem is remote */

	unsigned long	flags;

};