Return-Path: Received: from mail-pa0-f49.google.com ([209.85.220.49]:33593 "EHLO mail-pa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752523AbcERVIH (ORCPT ); Wed, 18 May 2016 17:08:07 -0400 Received: by mail-pa0-f49.google.com with SMTP id xk12so21408009pac.0 for ; Wed, 18 May 2016 14:08:06 -0700 (PDT) From: Tom Haynes To: Trond Myklebust Cc: Linux NFS Mailing list , Anna Schumaker Subject: [PATCH 1/3] nfs/flexfiles: Helper function to detect FF_FLAGS_NO_READ_IO Date: Wed, 18 May 2016 14:07:54 -0700 Message-Id: <1463605676-82483-2-git-send-email-loghyr@primarydata.com> In-Reply-To: <1463605676-82483-1-git-send-email-loghyr@primarydata.com> References: <1463605676-82483-1-git-send-email-loghyr@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: The mds can inform the client not to use the IOMODE_RW layout segment for doing READs. I.e., it is basically a IOMODE_WRITE layout segment. It would do this to not interfere with the WRITEs. Signed-off-by: Tom Haynes --- fs/nfs/flexfilelayout/flexfilelayout.h | 10 +++++++++- fs/nfs/flexfilelayout/flexfilelayoutdev.c | 6 ++++++ 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/fs/nfs/flexfilelayout/flexfilelayout.h b/fs/nfs/flexfilelayout/flexfilelayout.h index 8dabf64..c66c6c1 100644 --- a/fs/nfs/flexfilelayout/flexfilelayout.h +++ b/fs/nfs/flexfilelayout/flexfilelayout.h @@ -10,7 +10,8 @@ #define FS_NFS_NFS4FLEXFILELAYOUT_H #define FF_FLAGS_NO_LAYOUTCOMMIT 1 -#define FF_FLAGS_NO_IO_THRU_MDS 2 +#define FF_FLAGS_NO_IO_THRU_MDS 2 +#define FF_FLAGS_NO_READ_IO 4 #include "../pnfs.h" @@ -155,6 +156,12 @@ ff_layout_no_fallback_to_mds(struct pnfs_layout_segment *lseg) } static inline bool +ff_layout_no_read_on_rw(struct pnfs_layout_segment *lseg) +{ + return FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_READ_IO; +} + +static inline bool ff_layout_test_devid_unavailable(struct nfs4_deviceid_node *node) { return nfs4_test_deviceid_unavailable(node); @@ -194,6 +201,7 @@ struct rpc_cred *ff_layout_get_ds_cred(struct pnfs_layout_segment *lseg, u32 ds_idx, struct rpc_cred *mdscred); bool ff_layout_has_available_ds(struct pnfs_layout_segment *lseg); bool ff_layout_avoid_mds_available_ds(struct pnfs_layout_segment *lseg); +bool ff_layout_avoid_read_on_rw(struct pnfs_layout_segment *lseg); struct file *ff_local_open_fh(struct pnfs_layout_segment *lseg, u32 ds_idx, struct nfs_client *clp, struct rpc_cred *cred, diff --git a/fs/nfs/flexfilelayout/flexfilelayoutdev.c b/fs/nfs/flexfilelayout/flexfilelayoutdev.c index 1a603d4..b90c2bd 100644 --- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c +++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c @@ -623,6 +623,12 @@ bool ff_layout_avoid_mds_available_ds(struct pnfs_layout_segment *lseg) ff_layout_has_available_ds(lseg); } +bool ff_layout_avoid_read_on_rw(struct pnfs_layout_segment *lseg) +{ + return lseg->pls_range.iomode == IOMODE_RW && + ff_layout_no_read_on_rw(lseg); +} + module_param(dataserver_retrans, uint, 0644); MODULE_PARM_DESC(dataserver_retrans, "The number of times the NFSv4.1 client " "retries a request before it attempts further " -- 1.8.3.1