NFS: Fix the return value in nfs_page_mkwrite()

[linux-2.6-omap-h63xx.git] / fs / nfs / file.c

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 0abf3f331f56c6a20249a00bd4719cb1cd3b9112..5a97bcfe03e5e0d25b78d8122a6695f8d1c66acc 100644 (file)
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -35,6 +35,7 @@
 #include "delegation.h"
 #include "internal.h"
 #include "iostat.h"
+#include "fscache.h"
 
 #define NFSDBG_FACILITY                NFSDBG_FILE
 
@@ -409,6 +410,13 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
        return copied;
 }
 
+/*
+ * Partially or wholly invalidate a page
+ * - Release the private state associated with a page if undergoing complete
+ *   page invalidation
+ * - Called if either PG_private or PG_fscache is set on the page
+ * - Caller holds page lock
+ */
 static void nfs_invalidate_page(struct page *page, unsigned long offset)
 {
        dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %lu)\n", page, offset);
@@ -417,23 +425,43 @@ static void nfs_invalidate_page(struct page *page, unsigned long offset)
                return;
        /* Cancel any unstarted writes on this page */
        nfs_wb_page_cancel(page->mapping->host, page);
+
+       nfs_fscache_invalidate_page(page, page->mapping->host);
 }
 
+/*
+ * Attempt to release the private state associated with a page
+ * - Called if either PG_private or PG_fscache is set on the page
+ * - Caller holds page lock
+ * - Return true (may release page) or false (may not)
+ */
 static int nfs_release_page(struct page *page, gfp_t gfp)
 {
        dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);
 
        /* If PagePrivate() is set, then the page is not freeable */
-       return 0;
+       if (PagePrivate(page))
+               return 0;
+       return nfs_fscache_release_page(page, gfp);
 }
 
+/*
+ * Attempt to clear the private state associated with a page when an error
+ * occurs that requires the cached contents of an inode to be written back or
+ * destroyed
+ * - Called if either PG_private or fscache is set on the page
+ * - Caller holds page lock
+ * - Return 0 if successful, -error otherwise
+ */
 static int nfs_launder_page(struct page *page)
 {
        struct inode *inode = page->mapping->host;
+       struct nfs_inode *nfsi = NFS_I(inode);
 
        dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n",
                inode->i_ino, (long long)page_offset(page));
 
+       nfs_fscache_wait_on_page_write(nfsi, page);
        return nfs_wb_page(inode, page);
 }
 
@@ -451,6 +479,11 @@ const struct address_space_operations nfs_file_aops = {
        .launder_page = nfs_launder_page,
 };
 
+/*
+ * Notification that a PTE pointing to an NFS page is about to be made
+ * writable, implying that someone is about to modify the page through a
+ * shared-writable mapping
+ */
 static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
        struct page *page = vmf->page;
@@ -465,6 +498,9 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
                filp->f_mapping->host->i_ino,
                (long long)page_offset(page));
 
+       /* make sure the cache has finished storing the page */
+       nfs_fscache_wait_on_page_write(NFS_I(dentry->d_inode), page);
+
        lock_page(page);
        mapping = page->mapping;
        if (mapping != dentry->d_inode->i_mapping)
@@ -480,8 +516,6 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
                goto out_unlock;
 
        ret = nfs_updatepage(filp, page, 0, pagelen);
-       if (ret == 0)
-               ret = pagelen;
 out_unlock:
        unlock_page(page);
        if (ret)