NFS: Simplify O_DIRECT page referencing

The O_DIRECT code shouldn't need to hold 2 references to each page. The
reference held by the struct nfs_page should suffice.

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

1 files changed, 6 insertions, 16 deletions

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index af02bde7741e..78d1ead8bc30 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -268,10 +268,9 @@ static void nfs_direct_read_completion(struct nfs_pgio_header *hdr)
                         }
                         bytes += req->wb_bytes;
                         nfs_list_remove_request(req);
-                        nfs_direct_readpage_release(req);
                         if (!PageCompound(page))
                                 set_page_dirty(page);
-                        page_cache_release(page);
+                        nfs_direct_readpage_release(req);
                 }
         } else {
                 while (!list_empty(&hdr->pages)) {
@@ -281,7 +280,6 @@ static void nfs_direct_read_completion(struct nfs_pgio_header *hdr)
                                 if (!PageCompound(req->wb_page))
                                         set_page_dirty(req->wb_page);
                         bytes += req->wb_bytes;
-                        page_cache_release(req->wb_page);
                         nfs_list_remove_request(req);
                         nfs_direct_readpage_release(req);
                 }
@@ -375,8 +373,6 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
                                                  pagevec[i],
                                                  pgbase, req_len);
                         if (IS_ERR(req)) {
-                                nfs_direct_release_pages(pagevec + i,
-                                                         npages - i);
                                 result = PTR_ERR(req);
                                 break;
                         }
@@ -385,8 +381,6 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
                         if (!nfs_pageio_add_request(desc, req)) {
                                 result = desc->pg_error;
                                 nfs_release_request(req);
-                                nfs_direct_release_pages(pagevec + i,
-                                                         npages - i);
                                 break;
                         }
                         pgbase = 0;
@@ -396,6 +390,8 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
                         pos += req_len;
                         count -= req_len;
                 }
+                /* The nfs_page now hold references to these pages */
+                nfs_direct_release_pages(pagevec, npages);
         } while (count != 0 && result >= 0);
 
         kfree(pagevec);
@@ -509,7 +505,6 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
         nfs_pageio_complete(&desc);
 
         while (!list_empty(&failed)) {
-                page_cache_release(req->wb_page);
                 nfs_release_request(req);
                 nfs_unlock_request(req);
         }
@@ -542,10 +537,8 @@ static void nfs_direct_commit_complete(struct nfs_commit_data *data)
                 if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES) {
                         /* Note the rewrite will go through mds */
                         nfs_mark_request_commit(req, NULL, &cinfo);
-                } else {
-                        page_cache_release(req->wb_page);
+                } else
                         nfs_release_request(req);
-                }
                 nfs_unlock_request(req);
         }
 
@@ -678,8 +671,6 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *d
                                                  pagevec[i],
                                                  pgbase, req_len);
                         if (IS_ERR(req)) {
-                                nfs_direct_release_pages(pagevec + i,
-                                                         npages - i);
                                 result = PTR_ERR(req);
                                 break;
                         }
@@ -690,8 +681,6 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *d
                                 result = desc->pg_error;
                                 nfs_unlock_request(req);
                                 nfs_release_request(req);
-                                nfs_direct_release_pages(pagevec + i,
-                                                         npages - i);
                                 break;
                         }
                         pgbase = 0;
@@ -701,6 +690,8 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *d
                         pos += req_len;
                         count -= req_len;
                 }
+                /* The nfs_page now hold references to these pages */
+                nfs_direct_release_pages(pagevec, npages);
         } while (count != 0 && result >= 0);
 
         kfree(pagevec);
@@ -763,7 +754,6 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
                         nfs_mark_request_commit(req, hdr->lseg, &cinfo);
                         break;
                 default:
-                        page_cache_release(req->wb_page);
                         nfs_release_request(req);
                 }
                 nfs_unlock_request(req);