cifs: tune bdi.ra_pages in accordance with the rsize
Tune bdi.ra_pages to be a multiple of the rsize. This prevents the VFS
from asking for pages that require small reads to satisfy.
Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 06dfaac..f70d87d 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3182,6 +3182,22 @@
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 @@
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_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
/*