[PATCH] CIFS: fix cifs_user_read oops when null SMB response on forcedirectio mount

[deliverable/linux.git] / fs / cifs / file.c

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 77c990f0cb981706c55dcd936958c654d8f543e5..675bd25682979fc8a87bdb082da0bc3ec37d0ce9 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1190,7 +1190,6 @@ retry:
                                        /* BB what if continued retry is
                                           requested via mount flags? */
                                        set_bit(AS_EIO, &mapping->flags);
-                                       SetPageError(page);
                                } else {
                                        cifs_stats_bytes_written(cifs_sb->tcon,
                                                                 bytes_written);
@@ -1198,6 +1197,13 @@ retry:
                        }
                        for (i = 0; i < n_iov; i++) {
                                page = pvec.pages[first + i];
+                               /* Should we also set page error on
+                               success rc but too little data written? */
+                               /* BB investigate retry logic on temporary
+                               server crash cases and how recovery works
+                               when page marked as error */ 
+                               if(rc)
+                                       SetPageError(page);
                                kunmap(page);
                                unlock_page(page);
                                page_cache_release(page);
@@ -1436,13 +1442,15 @@ ssize_t cifs_user_read(struct file *file, char __user *read_data,
                                         &bytes_read, &smb_read_data,
                                         &buf_type);
                        pSMBr = (struct smb_com_read_rsp *)smb_read_data;
-                       if (copy_to_user(current_offset, 
-                                        smb_read_data + 4 /* RFC1001 hdr */
-                                        + le16_to_cpu(pSMBr->DataOffset), 
-                                        bytes_read)) {
-                               rc = -EFAULT;
-                       }
                        if (smb_read_data) {
+                               if (copy_to_user(current_offset,
+                                               smb_read_data +
+                                               4 /* RFC1001 length field */ +
+                                               le16_to_cpu(pSMBr->DataOffset),
+                                               bytes_read)) {
+                                       rc = -EFAULT;
+                               }
+
                                if(buf_type == CIFS_SMALL_BUFFER)
                                        cifs_small_buf_release(smb_read_data);
                                else if(buf_type == CIFS_LARGE_BUFFER)