pnfs: lookup new lseg at lseg boundary

Before mirroring support was added, the pageio descriptor's pg_lseg was
set to null when an RPC was sent. Because of this, pg_init was called
at lseg boundaries with pg_lseg = NULL, and it could be set to the new
lseg.

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index c7be9b997f5e..9304984bde80 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1788,10 +1788,16 @@ pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
                 seg_end = end_offset(pgio->pg_lseg->pls_range.offset,
                                      pgio->pg_lseg->pls_range.length);
                 req_start = req_offset(req);
-                WARN_ON_ONCE(req_start > seg_end);
+                WARN_ON_ONCE(req_start >= seg_end);
                 /* start of request is past the last byte of this segment */
-                if (req_start >= seg_end)
+                if (req_start >= seg_end) {
+                        /* reference the new lseg */
+                        if (pgio->pg_ops->pg_cleanup)
+                                pgio->pg_ops->pg_cleanup(pgio);
+                        if (pgio->pg_ops->pg_init)
+                                pgio->pg_ops->pg_init(pgio, req);
                         return 0;
+                }
 
                 /* adjust 'size' iff there are fewer bytes left in the
                  * segment than what nfs_generic_pg_test returned */