[PATCH 3.16 102/132] GFS2: Fix rgrp end rounding problem for bsize < page size

[Ben Hutchings]

3.16.74-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Bob Peterson <rpeterso@xxxxxxxxxx>

commit 31dddd9eb9ebae9a2a9b502750e9e481d752180a upstream.

This patch fixes a bug introduced by commit 7005c3e. That patch
tries to map a vm range for resource groups, but the calculation
breaks down when the block size is less than the page size.

Signed-off-by: Bob Peterson <rpeterso@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 fs/gfs2/rgrp.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -926,8 +926,9 @@ static int read_rindex_entry(struct gfs2
 		goto fail;
 
 	rgd->rd_gl->gl_object = rgd;
-	rgd->rd_gl->gl_vm.start = rgd->rd_addr * bsize;
-	rgd->rd_gl->gl_vm.end = rgd->rd_gl->gl_vm.start + (rgd->rd_length * bsize) - 1;
+	rgd->rd_gl->gl_vm.start = (rgd->rd_addr * bsize) & PAGE_CACHE_MASK;
+	rgd->rd_gl->gl_vm.end = PAGE_CACHE_ALIGN((rgd->rd_addr +
+						  rgd->rd_length) * bsize) - 1;
 	rgd->rd_rgl = (struct gfs2_rgrp_lvb *)rgd->rd_gl->gl_lksb.sb_lvbptr;
 	rgd->rd_flags &= ~GFS2_RDF_UPTODATE;
 	if (rgd->rd_data > sdp->sd_max_rg_data)