1 files changed, 76 insertions, 171 deletions

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index d63d964a0392..53ff70e23993 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -438,6 +438,7 @@ nfs_mark_request_commit(struct nfs_page *req)
         radix_tree_tag_set(&nfsi->nfs_page_tree,
                         req->wb_index,
                         NFS_PAGE_TAG_COMMIT);
+        nfsi->ncommit++;
         spin_unlock(&inode->i_lock);
         inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
         inc_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_RECLAIMABLE);
@@ -501,57 +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;
-}
-
-static void nfs_cancel_commit_list(struct list_head *head)
-{
-        struct nfs_page *req;
-
-        while(!list_empty(head)) {
-                req = nfs_list_entry(head->next);
-                nfs_list_remove_request(req);
-                nfs_clear_request_commit(req);
-                nfs_inode_remove_request(req);
-                nfs_unlock_request(req);
-        }
-}
-
 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
 static int
 nfs_need_commit(struct nfs_inode *nfsi)
@@ -573,11 +523,17 @@ static int
 nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, unsigned int npages)
 {
         struct nfs_inode *nfsi = NFS_I(inode);
+        int ret;
 
         if (!nfs_need_commit(nfsi))
                 return 0;
 
-        return nfs_scan_list(nfsi, dst, idx_start, npages, NFS_PAGE_TAG_COMMIT);
+        ret = nfs_scan_list(nfsi, dst, idx_start, npages, NFS_PAGE_TAG_COMMIT);
+        if (ret > 0)
+                nfsi->ncommit -= ret;
+        if (nfs_need_commit(NFS_I(inode)))
+                __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
+        return ret;
 }
 #else
 static inline int nfs_need_commit(struct nfs_inode *nfsi)
@@ -642,9 +598,10 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
                 spin_lock(&inode->i_lock);
         }
 
-        if (nfs_clear_request_commit(req))
-                radix_tree_tag_clear(&NFS_I(inode)->nfs_page_tree,
-                                req->wb_index, NFS_PAGE_TAG_COMMIT);
+        if (nfs_clear_request_commit(req) &&
+                        radix_tree_tag_clear(&NFS_I(inode)->nfs_page_tree,
+                                req->wb_index, NFS_PAGE_TAG_COMMIT) != NULL)
+                NFS_I(inode)->ncommit--;
 
         /* Okay, the request matches. Update the region */
         if (offset < req->wb_offset) {
@@ -1391,7 +1348,7 @@ static const struct rpc_call_ops nfs_commit_ops = {
         .rpc_release = nfs_commit_release,
 };
 
-int nfs_commit_inode(struct inode *inode, int how)
+static int nfs_commit_inode(struct inode *inode, int how)
 {
         LIST_HEAD(head);
         int res;
@@ -1406,92 +1363,51 @@ int nfs_commit_inode(struct inode *inode, int how)
         }
         return res;
 }
-#else
-static inline int nfs_commit_list(struct inode *inode, struct list_head *head, int how)
-{
-        return 0;
-}
-#endif
 
-long nfs_sync_mapping_wait(struct address_space *mapping, struct writeback_control *wbc, int how)
+static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc)
 {
-        struct inode *inode = mapping->host;
-        pgoff_t idx_start, idx_end;
-        unsigned int npages = 0;
-        LIST_HEAD(head);
-        int nocommit = how & FLUSH_NOCOMMIT;
-        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;
+        struct nfs_inode *nfsi = NFS_I(inode);
+        int flags = FLUSH_SYNC;
+        int ret = 0;
+
+        /* Don't commit yet if this is a non-blocking flush and there are
+         * lots of outstanding writes for this mapping.
+         */
+        if (wbc->sync_mode == WB_SYNC_NONE &&
+            nfsi->ncommit <= (nfsi->npages >> 1))
+                goto out_mark_dirty;
+
+        if (wbc->nonblocking || wbc->for_background)
+                flags = 0;
+        ret = nfs_commit_inode(inode, flags);
+        if (ret >= 0) {
+                if (wbc->sync_mode == WB_SYNC_NONE) {
+                        if (ret < wbc->nr_to_write)
+                                wbc->nr_to_write -= ret;
+                        else
+                                wbc->nr_to_write = 0;
                 }
+                return 0;
         }
-        how &= ~FLUSH_NOCOMMIT;
-        spin_lock(&inode->i_lock);
-        do {
-                ret = nfs_wait_on_requests_locked(inode, idx_start, npages);
-                if (ret != 0)
-                        continue;
-                if (nocommit)
-                        break;
-                pages = nfs_scan_commit(inode, &head, idx_start, npages);
-                if (pages == 0)
-                        break;
-                if (how & FLUSH_INVALIDATE) {
-                        spin_unlock(&inode->i_lock);
-                        nfs_cancel_commit_list(&head);
-                        ret = pages;
-                        spin_lock(&inode->i_lock);
-                        continue;
-                }
-                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);
+out_mark_dirty:
+        __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
         return ret;
 }
-
-static int __nfs_write_mapping(struct address_space *mapping, struct writeback_control *wbc, int how)
+#else
+static int nfs_commit_inode(struct inode *inode, int how)
 {
-        int ret;
-
-        ret = nfs_writepages(mapping, wbc);
-        if (ret < 0)
-                goto out;
-        ret = nfs_sync_mapping_wait(mapping, wbc, how);
-        if (ret < 0)
-                goto out;
         return 0;
-out:
-        __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
-        return ret;
 }
 
-/* Two pass sync: first using WB_SYNC_NONE, then WB_SYNC_ALL */
-static int nfs_write_mapping(struct address_space *mapping, int how)
+static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc)
 {
-        struct writeback_control wbc = {
-                .bdi = mapping->backing_dev_info,
-                .sync_mode = WB_SYNC_ALL,
-                .nr_to_write = LONG_MAX,
-                .range_start = 0,
-                .range_end = LLONG_MAX,
-        };
+        return 0;
+}
+#endif
 
-        return __nfs_write_mapping(mapping, &wbc, how);
+int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+        return nfs_commit_unstable_pages(inode, wbc);
 }
 
 /*
@@ -1499,37 +1415,26 @@ static int nfs_write_mapping(struct address_space *mapping, int how)
  */
 int nfs_wb_all(struct inode *inode)
 {
-        return nfs_write_mapping(inode->i_mapping, 0);
-}
+        struct writeback_control wbc = {
+                .sync_mode = WB_SYNC_ALL,
+                .nr_to_write = LONG_MAX,
+                .range_start = 0,
+                .range_end = LLONG_MAX,
+        };
 
-int nfs_wb_nocommit(struct inode *inode)
-{
-        return nfs_write_mapping(inode->i_mapping, FLUSH_NOCOMMIT);
+        return sync_inode(inode, &wbc);
 }
 
 int nfs_wb_page_cancel(struct inode *inode, struct page *page)
 {
         struct nfs_page *req;
-        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,
-                .range_start = range_start,
-                .range_end = range_end,
-        };
         int ret = 0;
 
         BUG_ON(!PageLocked(page));
         for (;;) {
                 req = nfs_page_find_request(page);
                 if (req == NULL)
-                        goto out;
-                if (test_bit(PG_CLEAN, &req->wb_flags)) {
-                        nfs_release_request(req);
                         break;
-                }
                 if (nfs_lock_request_dontget(req)) {
                         nfs_inode_remove_request(req);
                         /*
@@ -1543,54 +1448,54 @@ int nfs_wb_page_cancel(struct inode *inode, struct page *page)
                 ret = nfs_wait_on_request(req);
                 nfs_release_request(req);
                 if (ret < 0)
-                        goto out;
+                        break;
         }
-        if (!PagePrivate(page))
-                return 0;
-        ret = nfs_sync_mapping_wait(page->mapping, &wbc, FLUSH_INVALIDATE);
-out:
         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)