CIFS: Fix wsize usage in writepages

If a server change maximum buffer size for write (wsize) requests
on reconnect we can fail on repeating with a big size buffer on
-EAGAIN error in writepages. Fix this by checking wsize all the
time before repeating request in writepages.

Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 0064d38fdb76b4cf039d6b5014f9bb00bc7ebc53..ff4a9c3fe4215468289f88b275eba80ad89aee57 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2009,19 +2009,17 @@ wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
                        (loff_t)PAGE_CACHE_SIZE);
        wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) + wdata->tailsz;
 
-       do {
-               if (wdata->cfile != NULL)
-                       cifsFileInfo_put(wdata->cfile);
-               wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
-               if (!wdata->cfile) {
-                       cifs_dbg(VFS, "No writable handles for inode\n");
-                       rc = -EBADF;
-                       break;
-               }
+       if (wdata->cfile != NULL)
+               cifsFileInfo_put(wdata->cfile);
+       wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
+       if (!wdata->cfile) {
+               cifs_dbg(VFS, "No writable handles for inode\n");
+               rc = -EBADF;
+       } else {
                wdata->pid = wdata->cfile->pid;
                server = tlink_tcon(wdata->cfile->tlink)->ses->server;
                rc = server->ops->async_writev(wdata, cifs_writedata_release);
-       } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
+       }
 
        for (i = 0; i < nr_pages; ++i)
                unlock_page(wdata->pages[i]);
@@ -2058,7 +2056,7 @@ static int cifs_writepages(struct address_space *mapping,
 retry:
        while (!done && index <= end) {
                unsigned int i, nr_pages, found_pages;
-               pgoff_t next = 0, tofind;
+               pgoff_t next = 0, tofind, saved_index = index;
 
                tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
                                end - index) + 1;
@@ -2102,6 +2100,11 @@ retry:
                }
                kref_put(&wdata->refcount, cifs_writedata_release);
 
+               if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
+                       index = saved_index;
+                       continue;
+               }
+
                wbc->nr_to_write -= nr_pages;
                if (wbc->nr_to_write <= 0)
                        done = true;