pnfs-obj: pg_test check for max_io_size

Implement pg_test vector to test for max IO sizes. We calculate
a max_io_size member only once, and cache it in lseg so to not
do so on every page insert.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
[simplify logic]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>

1 files changed, 18 insertions, 1 deletions

diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c
index 3b10d09e5210..9cf208df1f25 100644
--- a/fs/nfs/objlayout/objio_osd.c
+++ b/fs/nfs/objlayout/objio_osd.c
@@ -128,6 +128,8 @@ struct objio_segment {
         u64 group_depth;
         unsigned group_count;
 
+        unsigned max_io_size;
+
         unsigned comps_index;
         unsigned num_comps;
         /* variable length */
@@ -365,6 +367,11 @@ int objio_alloc_lseg(struct pnfs_layout_segment **outp,
                 objio_seg->group_count = 1;
         }
 
+        /* Cache this calculation it will hit for every page */
+        objio_seg->max_io_size = (BIO_MAX_PAGES_KMALLOC * PAGE_SIZE -
+                                  objio_seg->stripe_unit) *
+                                 objio_seg->group_width;
+
         *outp = &objio_seg->lseg;
         return 0;
 
@@ -988,6 +995,16 @@ ssize_t objio_write_pagelist(struct objlayout_io_state *ol_state, bool stable)
         return _write_exec(ios);
 }
 
+static bool objio_pg_test(struct nfs_pageio_descriptor *pgio,
+                          struct nfs_page *prev, struct nfs_page *req)
+{
+        if (!pnfs_generic_pg_test(pgio, prev, req))
+                return false;
+
+        return pgio->pg_count + req->wb_bytes <=
+                        OBJIO_LSEG(pgio->pg_lseg)->max_io_size;
+}
+
 static struct pnfs_layoutdriver_type objlayout_type = {
         .id = LAYOUT_OSD2_OBJECTS,
         .name = "LAYOUT_OSD2_OBJECTS",
@@ -1001,7 +1018,7 @@ static struct pnfs_layoutdriver_type objlayout_type = {
 
         .read_pagelist           = objlayout_read_pagelist,
         .write_pagelist          = objlayout_write_pagelist,
-        .pg_test                 = pnfs_generic_pg_test,
+        .pg_test                 = objio_pg_test,
 
         .free_deviceid_node      = objio_free_deviceid_node,