[CIFS] Allow local filesize for file that is open for write to be updated
from server when mount forcedirectio.
Allowing update of file size with non forcedirectio mounts should be
allowed in the fiture but requires carefully writing out the
last page in the local file if it is a partial page in order to
avoid corruption and careful serialization
Thanks to Maximiliano Curia who suggested similar changes and provided
a testcase.
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index c249b62..670ec1e 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1835,10 +1835,20 @@
open_file = find_writable_file(cifsInode);
if(open_file) {
+ struct cifs_sb_info *cifs_sb;
+
/* there is not actually a write pending so let
this handle go free and allow it to
be closable if needed */
atomic_dec(&open_file->wrtPending);
+
+ cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
+ if ( cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO ) {
+ /* since no page cache to corrupt on directio
+ we can change size safely */
+ return 1;
+ }
+
return 0;
} else
return 1;