NFS: Simplify nfs_wb_page()
Trond Myklebust [Sat, 20 Feb 2010 01:03:28 +0000 (17:03 -0800)]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/write.c
include/linux/nfs_fs.h

index 0b32309..53ff70e 100644 (file)
@@ -502,44 +502,6 @@ int nfs_reschedule_unstable_write(struct nfs_page *req)
 }
 #endif
 
-/*
- * Wait for a request to complete.
- *
- * Interruptible by fatal signals only.
- */
-static int nfs_wait_on_requests_locked(struct inode *inode, pgoff_t idx_start, unsigned int npages)
-{
-       struct nfs_inode *nfsi = NFS_I(inode);
-       struct nfs_page *req;
-       pgoff_t idx_end, next;
-       unsigned int            res = 0;
-       int                     error;
-
-       if (npages == 0)
-               idx_end = ~0;
-       else
-               idx_end = idx_start + npages - 1;
-
-       next = idx_start;
-       while (radix_tree_gang_lookup_tag(&nfsi->nfs_page_tree, (void **)&req, next, 1, NFS_PAGE_TAG_LOCKED)) {
-               if (req->wb_index > idx_end)
-                       break;
-
-               next = req->wb_index + 1;
-               BUG_ON(!NFS_WBACK_BUSY(req));
-
-               kref_get(&req->wb_kref);
-               spin_unlock(&inode->i_lock);
-               error = nfs_wait_on_request(req);
-               nfs_release_request(req);
-               spin_lock(&inode->i_lock);
-               if (error < 0)
-                       return error;
-               res++;
-       }
-       return res;
-}
-
 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
 static int
 nfs_need_commit(struct nfs_inode *nfsi)
@@ -1432,7 +1394,7 @@ out_mark_dirty:
        return ret;
 }
 #else
-static inline int nfs_commit_list(struct inode *inode, struct list_head *head, int how)
+static int nfs_commit_inode(struct inode *inode, int how)
 {
        return 0;
 }
@@ -1448,46 +1410,6 @@ int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
        return nfs_commit_unstable_pages(inode, wbc);
 }
 
-long nfs_sync_mapping_wait(struct address_space *mapping, struct writeback_control *wbc, int how)
-{
-       struct inode *inode = mapping->host;
-       pgoff_t idx_start, idx_end;
-       unsigned int npages = 0;
-       LIST_HEAD(head);
-       long pages, ret;
-
-       /* FIXME */
-       if (wbc->range_cyclic)
-               idx_start = 0;
-       else {
-               idx_start = wbc->range_start >> PAGE_CACHE_SHIFT;
-               idx_end = wbc->range_end >> PAGE_CACHE_SHIFT;
-               if (idx_end > idx_start) {
-                       pgoff_t l_npages = 1 + idx_end - idx_start;
-                       npages = l_npages;
-                       if (sizeof(npages) != sizeof(l_npages) &&
-                                       (pgoff_t)npages != l_npages)
-                               npages = 0;
-               }
-       }
-       spin_lock(&inode->i_lock);
-       do {
-               ret = nfs_wait_on_requests_locked(inode, idx_start, npages);
-               if (ret != 0)
-                       continue;
-               pages = nfs_scan_commit(inode, &head, idx_start, npages);
-               if (pages == 0)
-                       break;
-               pages += nfs_scan_commit(inode, &head, 0, 0);
-               spin_unlock(&inode->i_lock);
-               ret = nfs_commit_list(inode, &head, how);
-               spin_lock(&inode->i_lock);
-
-       } while (ret >= 0);
-       spin_unlock(&inode->i_lock);
-       return ret;
-}
-
 /*
  * flush the inode to disk.
  */
@@ -1531,45 +1453,49 @@ int nfs_wb_page_cancel(struct inode *inode, struct page *page)
        return ret;
 }
 
-static int nfs_wb_page_priority(struct inode *inode, struct page *page,
-                               int how)
+/*
+ * Write back all requests on one page - we do this before reading it.
+ */
+int nfs_wb_page(struct inode *inode, struct page *page)
 {
        loff_t range_start = page_offset(page);
        loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
        struct writeback_control wbc = {
-               .bdi = page->mapping->backing_dev_info,
                .sync_mode = WB_SYNC_ALL,
-               .nr_to_write = LONG_MAX,
+               .nr_to_write = 0,
                .range_start = range_start,
                .range_end = range_end,
        };
+       struct nfs_page *req;
+       int need_commit;
        int ret;
 
-       do {
+       while(PagePrivate(page)) {
                if (clear_page_dirty_for_io(page)) {
                        ret = nfs_writepage_locked(page, &wbc);
                        if (ret < 0)
                                goto out_error;
-               } else if (!PagePrivate(page))
+               }
+               req = nfs_find_and_lock_request(page);
+               if (!req)
                        break;
-               ret = nfs_sync_mapping_wait(page->mapping, &wbc, how);
-               if (ret < 0)
+               if (IS_ERR(req)) {
+                       ret = PTR_ERR(req);
                        goto out_error;
-       } while (PagePrivate(page));
+               }
+               need_commit = test_bit(PG_CLEAN, &req->wb_flags);
+               nfs_clear_page_tag_locked(req);
+               if (need_commit) {
+                       ret = nfs_commit_inode(inode, FLUSH_SYNC);
+                       if (ret < 0)
+                               goto out_error;
+               }
+       }
        return 0;
 out_error:
-       __mark_inode_dirty(inode, I_DIRTY_PAGES);
        return ret;
 }
 
-/*
- * Write back all requests on one page - we do this before reading it.
- */
-int nfs_wb_page(struct inode *inode, struct page* page)
-{
-       return nfs_wb_page_priority(inode, page, FLUSH_STABLE);
-}
-
 #ifdef CONFIG_MIGRATION
 int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
                struct page *page)
index 93f439e..b789d85 100644 (file)
@@ -475,7 +475,6 @@ extern int nfs_writeback_done(struct rpc_task *, struct nfs_write_data *);
  * Try to write back everything synchronously (but check the
  * return value!)
  */
-extern long nfs_sync_mapping_wait(struct address_space *, struct writeback_control *, int);
 extern int nfs_wb_all(struct inode *inode);
 extern int nfs_wb_page(struct inode *inode, struct page* page);
 extern int nfs_wb_page_cancel(struct inode *inode, struct page* page);