NFS: Simplify nfs_wb_page()

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

1 files changed, 23 insertions, 97 deletions

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 0b323091b481..53ff70e23993 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -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)