From 154ecc793ec12c624740c3fc4a03ddb49372efef Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@redhat.com>
Date: Wed, 19 Oct 2011 15:30:35 -0400
Subject: [PATCH] --- yaml --- r: 269975 b: refs/heads/master c:
 66bfaadc3da74fecb4ba8b03f6b81d5f58b031fa h: refs/heads/master i:   269973:
 77ef0895eccaa0986f22f4b30788a11fd2eeabe0   269971:
 63c2679ebc2cc17220964ea751c8c979aef4f2ca   269967:
 99a3f43222b13fe05dfbdf6ef75fe3a51f516953 v: v3

---
 [refs]                  |  2 +-
 trunk/fs/cifs/connect.c | 21 +++++++++++++++++++--
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index cdb706a53a73..1b0e48ee66f3 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5eba8ab3606621f7e175ae9f521d71f3ac534f82
+refs/heads/master: 66bfaadc3da74fecb4ba8b03f6b81d5f58b031fa
diff --git a/trunk/fs/cifs/connect.c b/trunk/fs/cifs/connect.c
index 06dfaacfea5d..f70d87d6ba61 100644
--- a/trunk/fs/cifs/connect.c
+++ b/trunk/fs/cifs/connect.c
@@ -3182,6 +3182,22 @@ cifs_get_volume_info(char *mount_data, const char *devname)
 	return volume_info;
 }
 
+/* make sure ra_pages is a multiple of rsize */
+static inline unsigned int
+cifs_ra_pages(struct cifs_sb_info *cifs_sb)
+{
+	unsigned int reads;
+	unsigned int rsize_pages = cifs_sb->rsize / PAGE_CACHE_SIZE;
+
+	if (rsize_pages >= default_backing_dev_info.ra_pages)
+		return default_backing_dev_info.ra_pages;
+	else if (rsize_pages == 0)
+		return rsize_pages;
+
+	reads = default_backing_dev_info.ra_pages / rsize_pages;
+	return reads * rsize_pages;
+}
+
 int
 cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *volume_info)
 {
@@ -3200,8 +3216,6 @@ cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *volume_info)
 	if (rc)
 		return rc;
 
-	cifs_sb->bdi.ra_pages = default_backing_dev_info.ra_pages;
-
 #ifdef CONFIG_CIFS_DFS_UPCALL
 try_mount_again:
 	/* cleanup activities if we're chasing a referral */
@@ -3269,6 +3283,9 @@ cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *volume_info)
 	cifs_sb->wsize = cifs_negotiate_wsize(tcon, volume_info);
 	cifs_sb->rsize = cifs_negotiate_rsize(tcon, volume_info);
 
+	/* tune readahead according to rsize */
+	cifs_sb->bdi.ra_pages = cifs_ra_pages(cifs_sb);
+
 remote_path_check:
 #ifdef CONFIG_CIFS_DFS_UPCALL
 	/*