pnfs: allow non page aligned pnfs layout segments

Remove alignment checks that would revert to MDS and change pg_test
to return the max ammount left in the segment (or other pg_test call)
up to size of passed request, or 0 if no space is left.

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 10 insertions, 15 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 6ef108b1d85f..ce46a417e500 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1388,11 +1388,6 @@ pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *r
 
         WARN_ON_ONCE(pgio->pg_lseg != NULL);
 
-        if (req->wb_offset != req->wb_pgbase) {
-                nfs_pageio_reset_read_mds(pgio);
-                return;
-        }
-
         if (pgio->pg_dreq == NULL)
                 rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
         else
@@ -1417,11 +1412,6 @@ pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
 {
         WARN_ON_ONCE(pgio->pg_lseg != NULL);
 
-        if (req->wb_offset != req->wb_pgbase) {
-                nfs_pageio_reset_write_mds(pgio);
-                return;
-        }
-
         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
                                            req->wb_context,
                                            req_offset(req),
@@ -1443,9 +1433,9 @@ pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
                      struct nfs_page *req)
 {
         unsigned int size;
+        u64 end;
 
         size = nfs_generic_pg_test(pgio, prev, req);
-
         if (!size)
                 return 0;
 
@@ -1463,11 +1453,16 @@ pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
          * first byte that lies outside the pnfs_layout_range. FIXME?
          *
          */
-        if (req_offset(req) >= end_offset(pgio->pg_lseg->pls_range.offset,
-                                         pgio->pg_lseg->pls_range.length))
-                return 0;
+        if (pgio->pg_lseg) {
+                end = end_offset(pgio->pg_lseg->pls_range.offset,
+                                 pgio->pg_lseg->pls_range.length);
+                WARN_ON_ONCE(req_offset(req) > end);
+                if (req_offset(req) >= end)
+                        return 0;
+                size = min((unsigned int)(end - req_offset(req)), size);
+        }
 
-        return min(size, req->wb_bytes);
+        return size;
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);