NFS: nfs_set_page_writeback no longer needs to reference the page

We now hold a reference to the nfs_page across the calls to
nfs_set_page_writeback and nfs_end_page_writeback, and that
means we already have a reference to the struct page.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index fd36b31..8382329 100644 (file)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -230,7 +230,6 @@ static int nfs_set_page_writeback(struct page *page)
                struct inode *inode = page->mapping->host;
                struct nfs_server *nfss = NFS_SERVER(inode);
 
-               page_cache_get(page);
                if (atomic_long_inc_return(&nfss->writeback) >
                                NFS_CONGESTION_ON_THRESH) {
                        set_bdi_congested(&nfss->backing_dev_info,
@@ -246,7 +245,6 @@ static void nfs_end_page_writeback(struct page *page)
        struct nfs_server *nfss = NFS_SERVER(inode);
 
        end_page_writeback(page);
-       page_cache_release(page);
        if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
                clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC);
 }
@@ -607,13 +605,12 @@ static void nfs_write_completion(struct nfs_pgio_header *hdr)
        nfs_init_cinfo_from_inode(&cinfo, hdr->inode);
        while (!list_empty(&hdr->pages)) {
                struct nfs_page *req = nfs_list_entry(hdr->pages.next);
-               struct page *page = req->wb_page;
 
                bytes += req->wb_bytes;
                nfs_list_remove_request(req);
                if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) &&
                    (hdr->good_bytes < bytes)) {
-                       nfs_set_pageerror(page);
+                       nfs_set_pageerror(req->wb_page);
                        nfs_context_set_write_error(req->wb_context, hdr->error);
                        goto remove_req;
                }
@@ -629,7 +626,7 @@ remove_req:
                nfs_inode_remove_request(req);
 next:
                nfs_unlock_request_dont_release(req);
-               nfs_end_page_writeback(page);
+               nfs_end_page_writeback(req->wb_page);
                nfs_release_request(req);
        }
 out:
@@ -1040,11 +1037,9 @@ static int nfs_do_multiple_writes(struct list_head *head,
  */
 static void nfs_redirty_request(struct nfs_page *req)
 {
-       struct page *page = req->wb_page;
-
        nfs_mark_request_dirty(req);
        nfs_unlock_request_dont_release(req);
-       nfs_end_page_writeback(page);
+       nfs_end_page_writeback(req->wb_page);
        nfs_release_request(req);
 }