NFSv4.1: coelesce across layout stripes
Add a pg_test layout driver hook which is used to avoid coelescing I/O across
layout stripes.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index e1164e3..9b9a65c 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -226,6 +226,7 @@
desc->pg_doio = doio;
desc->pg_ioflags = io_flags;
desc->pg_error = 0;
+ desc->pg_lseg = NULL;
}
/**
@@ -240,7 +241,8 @@
* Return 'true' if this is the case, else return 'false'.
*/
static int nfs_can_coalesce_requests(struct nfs_page *prev,
- struct nfs_page *req)
+ struct nfs_page *req,
+ struct nfs_pageio_descriptor *pgio)
{
if (req->wb_context->cred != prev->wb_context->cred)
return 0;
@@ -254,6 +256,12 @@
return 0;
if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
return 0;
+ /*
+ * Non-whole file layouts need to check that req is inside of
+ * pgio->pg_lseg.
+ */
+ if (pgio->pg_test && !pgio->pg_test(pgio, prev, req))
+ return 0;
return 1;
}
@@ -286,7 +294,7 @@
if (newlen > desc->pg_bsize)
return 0;
prev = nfs_list_entry(desc->pg_list.prev);
- if (!nfs_can_coalesce_requests(prev, req))
+ if (!nfs_can_coalesce_requests(prev, req, desc))
return 0;
} else
desc->pg_base = req->wb_pgbase;