CIFS: Optimize readpages in a short read case on reconnects

by marking pages with a data from a partially received response up-to-date.
This is suitable for non-signed connections.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 8 insertions, 3 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 5d2501df8f6b..12b64e02eee1 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -3281,25 +3281,30 @@ int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
 static void
 cifs_readv_complete(struct work_struct *work)
 {
-        unsigned int i;
+        unsigned int i, got_bytes;
         struct cifs_readdata *rdata = container_of(work,
                                                 struct cifs_readdata, work);
 
+        got_bytes = rdata->got_bytes;
         for (i = 0; i < rdata->nr_pages; i++) {
                 struct page *page = rdata->pages[i];
 
                 lru_cache_add_file(page);
 
-                if (rdata->result == 0) {
+                if (rdata->result == 0 ||
+                    (rdata->result == -EAGAIN && got_bytes)) {
                         flush_dcache_page(page);
                         SetPageUptodate(page);
                 }
 
                 unlock_page(page);
 
-                if (rdata->result == 0)
+                if (rdata->result == 0 ||
+                    (rdata->result == -EAGAIN && got_bytes))
                         cifs_readpage_to_fscache(rdata->mapping->host, page);
 
+                got_bytes -= min_t(unsigned int, PAGE_CACHE_SIZE, got_bytes);
+
                 page_cache_release(page);
                 rdata->pages[i] = NULL;
         }