NFS: Remove BUG_ON() calls from the generic writeback code

...and ensure that we set the return value for nfs_page_async_flush()
to zero! (Reported-by: Dros Adamson)

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

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 9347ab7c9574fa3b2468a54449d85d366aaf6b61..f5bc8e11713ba82f8861b9727e5ade4aedbe68ac 100644 (file)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -239,21 +239,18 @@ int nfs_congestion_kb;
 #define NFS_CONGESTION_OFF_THRESH      \
        (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))
 
-static int nfs_set_page_writeback(struct page *page)
+static void nfs_set_page_writeback(struct page *page)
 {
+       struct nfs_server *nfss = NFS_SERVER(page_file_mapping(page)->host);
        int ret = test_set_page_writeback(page);
 
-       if (!ret) {
-               struct inode *inode = page_file_mapping(page)->host;
-               struct nfs_server *nfss = NFS_SERVER(inode);
+       WARN_ON_ONCE(ret != 0);
 
-               if (atomic_long_inc_return(&nfss->writeback) >
-                               NFS_CONGESTION_ON_THRESH) {
-                       set_bdi_congested(&nfss->backing_dev_info,
-                                               BLK_RW_ASYNC);
-               }
+       if (atomic_long_inc_return(&nfss->writeback) >
+                       NFS_CONGESTION_ON_THRESH) {
+               set_bdi_congested(&nfss->backing_dev_info,
+                                       BLK_RW_ASYNC);
        }
-       return ret;
 }
 
 static void nfs_end_page_writeback(struct page *page)
@@ -315,10 +312,10 @@ static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
        if (IS_ERR(req))
                goto out;
 
-       ret = nfs_set_page_writeback(page);
-       BUG_ON(ret != 0);
-       BUG_ON(test_bit(PG_CLEAN, &req->wb_flags));
+       nfs_set_page_writeback(page);
+       WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags));
 
+       ret = 0;
        if (!nfs_pageio_add_request(pgio, req)) {
                nfs_redirty_request(req);
                ret = pgio->pg_error;
@@ -451,8 +448,6 @@ static void nfs_inode_remove_request(struct nfs_page *req)
        struct inode *inode = req->wb_context->dentry->d_inode;
        struct nfs_inode *nfsi = NFS_I(inode);
 
-       BUG_ON (!NFS_WBACK_BUSY(req));
-
        spin_lock(&inode->i_lock);
        if (likely(!PageSwapCache(req->wb_page))) {
                set_page_private(req->wb_page, 0);
@@ -1727,7 +1722,6 @@ int nfs_wb_page_cancel(struct inode *inode, struct page *page)
        struct nfs_page *req;
        int ret = 0;
 
-       BUG_ON(!PageLocked(page));
        for (;;) {
                wait_on_page_writeback(page);
                req = nfs_page_find_request(page);