NFS: Store pointer to the nfs_page in page->private

This will allow fast lookup of the nfs_page from the struct page instead of
having to search the radix tree.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 33 insertions, 33 deletions

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 310fdeca6250..6df8319de060 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -155,6 +155,29 @@ void nfs_writedata_release(void *wdata)
         nfs_writedata_free(wdata);
 }
 
+static struct nfs_page *nfs_page_find_request_locked(struct page *page)
+{
+        struct nfs_page *req = NULL;
+
+        if (PagePrivate(page)) {
+                req = (struct nfs_page *)page_private(page);
+                if (req != NULL)
+                        atomic_inc(&req->wb_count);
+        }
+        return req;
+}
+
+static struct nfs_page *nfs_page_find_request(struct page *page)
+{
+        struct nfs_page *req = NULL;
+        spinlock_t *req_lock = &NFS_I(page->mapping->host)->req_lock;
+
+        spin_lock(req_lock);
+        req = nfs_page_find_request_locked(page);
+        spin_unlock(req_lock);
+        return req;
+}
+
 /* Adjust the file length if we're writing beyond the end */
 static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
 {
@@ -429,6 +452,7 @@ static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
                         nfsi->change_attr++;
         }
         SetPagePrivate(req->wb_page);
+        set_page_private(req->wb_page, (unsigned long)req);
         nfsi->npages++;
         atomic_inc(&req->wb_count);
         return 0;
@@ -445,6 +469,7 @@ static void nfs_inode_remove_request(struct nfs_page *req)
         BUG_ON (!NFS_WBACK_BUSY(req));
 
         spin_lock(&nfsi->req_lock);
+        set_page_private(req->wb_page, 0);
         ClearPagePrivate(req->wb_page);
         radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index);
         nfsi->npages--;
@@ -459,33 +484,6 @@ static void nfs_inode_remove_request(struct nfs_page *req)
 }
 
 /*
- * Find a request
- */
-static inline struct nfs_page *
-_nfs_find_request(struct inode *inode, unsigned long index)
-{
-        struct nfs_inode *nfsi = NFS_I(inode);
-        struct nfs_page *req;
-
-        req = (struct nfs_page*)radix_tree_lookup(&nfsi->nfs_page_tree, index);
-        if (req)
-                atomic_inc(&req->wb_count);
-        return req;
-}
-
-static struct nfs_page *
-nfs_find_request(struct inode *inode, unsigned long index)
-{
-        struct nfs_page         *req;
-        struct nfs_inode        *nfsi = NFS_I(inode);
-
-        spin_lock(&nfsi->req_lock);
-        req = _nfs_find_request(inode, index);
-        spin_unlock(&nfsi->req_lock);
-        return req;
-}
-
-/*
  * Add a request to the inode's dirty list.
  */
 static void
@@ -699,10 +697,11 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx,
                  * A request for the page we wish to update
                  */
                 spin_lock(&nfsi->req_lock);
-                req = _nfs_find_request(inode, page->index);
+                req = nfs_page_find_request_locked(page);
                 if (req) {
                         if (!nfs_lock_request_dontget(req)) {
                                 int error;
+
                                 spin_unlock(&nfsi->req_lock);
                                 error = nfs_wait_on_request(req);
                                 nfs_release_request(req);
@@ -770,7 +769,6 @@ static struct nfs_page * nfs_update_request(struct nfs_open_context* ctx,
 int nfs_flush_incompatible(struct file *file, struct page *page)
 {
         struct nfs_open_context *ctx = (struct nfs_open_context *)file->private_data;
-        struct inode    *inode = page->mapping->host;
         struct nfs_page *req;
         int             status = 0;
         /*
@@ -781,11 +779,13 @@ int nfs_flush_incompatible(struct file *file, struct page *page)
          * Also do the same if we find a request from an existing
          * dropped page.
          */
-        req = nfs_find_request(inode, page->index);
-        if (req) {
-                if (req->wb_page != page || ctx != req->wb_context)
-                        status = nfs_wb_page(inode, page);
+        req = nfs_page_find_request(page);
+        if (req != NULL) {
+                int do_flush = req->wb_page != page || req->wb_context != ctx;
+
                 nfs_release_request(req);
+                if (do_flush)
+                        status = nfs_wb_page(page->mapping->host, page);
         }
         return (status < 0) ? status : 0;
 }