nfs: call nfs_can_coalesce_requests for every req

Call nfs_can_coalesce_requests for every request, even the first one.
This is needed for future patches to give pg_test a way to inform
add_request to reduce the size of the request.

Now @prev can be null in nfs_can_coalesce_requests and pg_test functions.

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

diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index ba9a9aadf6c8056803f2e9c4106e1c339a695c1c..9319427e43e34ebc3b209d7efb998e9732c4f456 100644 (file)
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/nfs4filelayout.c
@@ -929,6 +929,9 @@ filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
            !nfs_generic_pg_test(pgio, prev, req))
                return 0;
 
+       if (!prev)
+               return req->wb_bytes;
+
        p_stripe = (u64)req_offset(prev);
        r_stripe = (u64)req_offset(req);
        stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 82233431880dc25a5794c7b8cdb561f2cb715b1b..f343f49ff596b71875331ef0a4723a31719dd882 100644 (file)
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -292,6 +292,8 @@ nfs_wait_on_request(struct nfs_page *req)
 size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
                           struct nfs_page *prev, struct nfs_page *req)
 {
+       if (!prev)
+               return req->wb_bytes;
        /*
         * FIXME: ideally we should be able to coalesce all requests
         * that are not block boundary aligned, but currently this
@@ -761,17 +763,20 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
 {
        size_t size;
 
-       if (!nfs_match_open_context(req->wb_context, prev->wb_context))
-               return false;
-       if (req->wb_context->dentry->d_inode->i_flock != NULL &&
-           !nfs_match_lock_context(req->wb_lock_context, prev->wb_lock_context))
-               return false;
-       if (req->wb_pgbase != 0)
-               return false;
-       if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
-               return false;
-       if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
-               return false;
+       if (prev) {
+               if (!nfs_match_open_context(req->wb_context, prev->wb_context))
+                       return false;
+               if (req->wb_context->dentry->d_inode->i_flock != NULL &&
+                   !nfs_match_lock_context(req->wb_lock_context,
+                                           prev->wb_lock_context))
+                       return false;
+               if (req->wb_pgbase != 0)
+                       return false;
+               if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
+                       return false;
+               if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
+                       return false;
+       }
        size = pgio->pg_ops->pg_test(pgio, prev, req);
        WARN_ON_ONCE(size && size != req->wb_bytes);
        return size > 0;
@@ -788,17 +793,16 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
 static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
                                     struct nfs_page *req)
 {
+       struct nfs_page *prev = NULL;
        if (desc->pg_count != 0) {
-               struct nfs_page *prev;
-
                prev = nfs_list_entry(desc->pg_list.prev);
-               if (!nfs_can_coalesce_requests(prev, req, desc))
-                       return 0;
        } else {
                if (desc->pg_ops->pg_init)
                        desc->pg_ops->pg_init(desc, req);
                desc->pg_base = req->wb_pgbase;
        }
+       if (!nfs_can_coalesce_requests(prev, req, desc))
+               return 0;
        nfs_list_remove_request(req);
        nfs_list_add_request(req, &desc->pg_list);
        desc->pg_count += req->wb_bytes;