From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f172.google.com ([209.85.192.172]:32837 "EHLO mail-pf0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753811AbcEYObp (ORCPT ); Wed, 25 May 2016 10:31:45 -0400 Received: by mail-pf0-f172.google.com with SMTP id b124so19147970pfb.0 for ; Wed, 25 May 2016 07:31:45 -0700 (PDT) From: Tom Haynes To: Trond Myklebust Cc: Linux NFS Mailing list , Anna Schumaker Subject: [V2 1/3] nfs/flexfiles: Helper function to detect FF_FLAGS_NO_READ_IO Date: Wed, 25 May 2016 07:31:12 -0700 Message-Id: <1464186674-104401-2-git-send-email-loghyr@primarydata.com> In-Reply-To: <1464186674-104401-1-git-send-email-loghyr@primarydata.com> References: <1464186674-104401-1-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 | 11 ++++++++++- fs/nfs/flexfilelayout/flexfilelayoutdev.c | 6 ++++++ 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/fs/nfs/flexfilelayout/flexfilelayout.h b/fs/nfs/flexfilelayout/flexfilelayout.h index b540581..1bcdb15 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" @@ -153,6 +154,12 @@ 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); @@ -192,4 +199,6 @@ 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); + #endif /* FS_NFS_NFS4FLEXFILELAYOUT_H */ diff --git a/fs/nfs/flexfilelayout/flexfilelayoutdev.c b/fs/nfs/flexfilelayout/flexfilelayoutdev.c index 35d84d0..0aa36be 100644 --- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c +++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c @@ -557,6 +557,12 @@ 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