From: The pNFS Team <linux-nfs@xxxxxxxxxxxxxxx>
Signed-off-by: Andy Adamson <andros@xxxxxxxxxxxxxx>
Signed-off-by: Dean Hildebrand <dhildeb@xxxxxxxxxx>
Signed-off-by: Oleg Drokin <green@xxxxxxxxxxxxxx>
Signed-off-by: Tao Guo <guotao@xxxxxxxxxxxx>
Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
Signed-off-by: Fred Isaman <iisaman@xxxxxxxxxx>
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
---
fs/nfs/nfs4filelayout.c | 28 ++++++++++++++++++++++++++++
1 files changed, 28 insertions(+), 0 deletions(-)
diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index 23f930c..8b1c4ad 100644
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/nfs4filelayout.c
@@ -252,6 +252,33 @@ filelayout_free_lseg(struct pnfs_layout_segment *lseg)
_filelayout_free_lseg(fl);
}
+/*
+ * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
+ *
+ * return 1 : coalesce page
+ * return 0 : don't coalesce page
+ *
+ * By the time this is called, we know req->wb_lseg == prev->wb_lseg
+ */
+int
+filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
+ struct nfs_page *req)
+{
+ u64 p_stripe, r_stripe;
+ u32 stripe_unit;
+
+ if (!req->wb_lseg)
+ return 1;
+ p_stripe = (u64)prev->wb_index << PAGE_CACHE_SHIFT;
+ r_stripe = (u64)req->wb_index << PAGE_CACHE_SHIFT;
+ stripe_unit = FILELAYOUT_LSEG(req->wb_lseg)->stripe_unit;
+
+ do_div(p_stripe, stripe_unit);
+ do_div(r_stripe, stripe_unit);
+
+ return (p_stripe == r_stripe);
+}
+
static struct pnfs_layoutdriver_type filelayout_type = {
.id = LAYOUT_NFSV4_1_FILES,
.name = "LAYOUT_NFSV4_1_FILES",
@@ -260,6 +287,7 @@ static struct pnfs_layoutdriver_type filelayout_type = {
.clear_layoutdriver = filelayout_clear_layoutdriver,
.alloc_lseg = filelayout_alloc_lseg,
.free_lseg = filelayout_free_lseg,
+ .pg_test = filelayout_pg_test,
};
static int __init nfs4filelayout_init(void)
--
1.6.6
--
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