nfs: only remove page from mapping if launder_page fails

Instead of dropping pages when write fails, only do it when
we get fatal failure in launder_page write back.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 93e236429c5d785a1711d643d0b4676dfe4396cf..f188dd071dfcfb9fc3b3e05053aaed172b69e217 100644 (file)
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -545,7 +545,7 @@ static int nfs_launder_page(struct page *page)
                inode->i_ino, (long long)page_offset(page));
 
        nfs_fscache_wait_on_page_write(nfsi, page);
-       return nfs_wb_page(inode, page);
+       return nfs_wb_launder_page(inode, page);
 }
 
 static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file,

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 9dafb08ddae533981f149ecebfd83d5f01625cb2..4d254232d7283d8dfde0d793f2c33103c0c4c182 100644 (file)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -559,7 +559,8 @@ static void nfs_write_error_remove_page(struct nfs_page *req)
  * May return an error if the user signalled nfs_wait_on_request().
  */
 static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
-                               struct page *page, bool nonblock)
+                               struct page *page, bool nonblock,
+                               bool launder)
 {
        struct nfs_page *req;
        int ret = 0;
@@ -578,17 +579,19 @@ static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
        if (!nfs_pageio_add_request(pgio, req)) {
                ret = pgio->pg_error;
                /*
-                * Remove the problematic req upon fatal errors,
-                * while other dirty pages can still be around
-                * until they get flushed.
+                * Remove the problematic req upon fatal errors
+                * in launder case, while other dirty pages can
+                * still be around until they get flushed.
                 */
                if (nfs_error_is_fatal(ret)) {
                        nfs_context_set_write_error(req->wb_context, ret);
-                       nfs_write_error_remove_page(req);
-               } else {
-                       nfs_redirty_request(req);
-                       ret = -EAGAIN;
+                       if (launder) {
+                               nfs_write_error_remove_page(req);
+                               goto out;
+                       }
                }
+               nfs_redirty_request(req);
+               ret = -EAGAIN;
        } else
                nfs_add_stats(page_file_mapping(page)->host,
                                NFSIOS_WRITEPAGES, 1);
@@ -596,12 +599,14 @@ out:
        return ret;
 }
 
-static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio)
+static int nfs_do_writepage(struct page *page, struct writeback_control *wbc,
+                           struct nfs_pageio_descriptor *pgio, bool launder)
 {
        int ret;
 
        nfs_pageio_cond_complete(pgio, page_file_index(page));
-       ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE);
+       ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE,
+                                  launder);
        if (ret == -EAGAIN) {
                redirty_page_for_writepage(wbc, page);
                ret = 0;
@@ -612,7 +617,9 @@ static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, st
 /*
  * Write an mmapped page to the server.
  */
-static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc)
+static int nfs_writepage_locked(struct page *page,
+                               struct writeback_control *wbc,
+                               bool launder)
 {
        struct nfs_pageio_descriptor pgio;
        struct inode *inode = page_file_mapping(page)->host;
@@ -621,7 +628,7 @@ static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc
        nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
        nfs_pageio_init_write(&pgio, inode, wb_priority(wbc),
                                false, &nfs_async_write_completion_ops);
-       err = nfs_do_writepage(page, wbc, &pgio);
+       err = nfs_do_writepage(page, wbc, &pgio, launder);
        nfs_pageio_complete(&pgio);
        if (err < 0)
                return err;
@@ -634,7 +641,7 @@ int nfs_writepage(struct page *page, struct writeback_control *wbc)
 {
        int ret;
 
-       ret = nfs_writepage_locked(page, wbc);
+       ret = nfs_writepage_locked(page, wbc, false);
        unlock_page(page);
        return ret;
 }
@@ -643,7 +650,7 @@ static int nfs_writepages_callback(struct page *page, struct writeback_control *
 {
        int ret;
 
-       ret = nfs_do_writepage(page, wbc, data);
+       ret = nfs_do_writepage(page, wbc, data, false);
        unlock_page(page);
        return ret;
 }
@@ -1931,7 +1938,7 @@ int nfs_wb_page_cancel(struct inode *inode, struct page *page)
 /*
  * Write back all requests on one page - we do this before reading it.
  */
-int nfs_wb_page(struct inode *inode, struct page *page)
+int nfs_wb_single_page(struct inode *inode, struct page *page, bool launder)
 {
        loff_t range_start = page_file_offset(page);
        loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1);
@@ -1948,7 +1955,7 @@ int nfs_wb_page(struct inode *inode, struct page *page)
        for (;;) {
                wait_on_page_writeback(page);
                if (clear_page_dirty_for_io(page)) {
-                       ret = nfs_writepage_locked(page, &wbc);
+                       ret = nfs_writepage_locked(page, &wbc, launder);
                        if (ret < 0)
                                goto out_error;
                        continue;

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index c0e961474a527058c8d1ac2aa72070c9b15e3db5..b88fc46cfbb8186698b1baca6fb5090634515c73 100644 (file)
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -517,12 +517,24 @@ extern int  nfs_updatepage(struct file *, struct page *, unsigned int, unsigned
  */
 extern int nfs_sync_inode(struct inode *inode);
 extern int nfs_wb_all(struct inode *inode);
-extern int nfs_wb_page(struct inode *inode, struct page* page);
+extern int nfs_wb_single_page(struct inode *inode, struct page *page, bool launder);
 extern int nfs_wb_page_cancel(struct inode *inode, struct page* page);
 extern int  nfs_commit_inode(struct inode *, int);
 extern struct nfs_commit_data *nfs_commitdata_alloc(void);
 extern void nfs_commit_free(struct nfs_commit_data *data);
 
+static inline int
+nfs_wb_launder_page(struct inode *inode, struct page *page)
+{
+       return nfs_wb_single_page(inode, page, true);
+}
+
+static inline int
+nfs_wb_page(struct inode *inode, struct page *page)
+{
+       return nfs_wb_single_page(inode, page, false);
+}
+
 static inline int
 nfs_have_writebacks(struct inode *inode)
 {