From: Joe Jin <joe.jin@oracle.com>
Date: Mon, 4 Jun 2012 05:45:02 +0000 (+0800)
Subject: dm-nfs: force random mode for the backend file
X-Git-Tag: v2.6.39-400.9.0~499^2~15
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=8bdd8d54fc0ec89f396062b3c18da6b0f5d904cb;p=users%2Fjedix%2Flinux-maple.git

dm-nfs: force random mode for the backend file

Orabug: 14092678
Without this flag page_cache_sync_readahead() might take some seconds to
complete.
Since dm-nfs used for ovm and as vdisk, random access is expect, so force
set this flag when open the backend file.

Signed-off-by: Joe Jin <joe.jin@oracle.com>
Cc: Adnan Misherfi <adnan.misherfi@oracle.com>
Cc: Kurt C Hackel <kurt.hackel@oracle.com>
Cc: Andrew Thomas <andrew.thomas@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---

diff --git a/drivers/md/dm-nfs.c b/drivers/md/dm-nfs.c
index 2ee7e5ff9179..e03b9948307e 100644
--- a/drivers/md/dm-nfs.c
+++ b/drivers/md/dm-nfs.c
@@ -197,6 +197,9 @@ static int dm_nfs_io_get_file(struct dm_target *ti, uid_t uid)
 	filp = filp_open(nc->path, flags, 0);
 	if (IS_ERR(filp))
 		return PTR_ERR(filp);
+
+	/* Force random reference */
+	filp->f_mode |= FMODE_RANDOM;
 	nc->filp = filp;
 
 	r = _check_file(ti);