CIFS: Respect O_SYNC and O_DIRECT flags during reconnect

commit 44805b0e62f15e90d233485420e1847133716bdc upstream.

Currently the client translates O_SYNC and O_DIRECT flags
into corresponding SMB create options when openning a file.
The problem is that on reconnect when the file is being
re-opened the client doesn't set those flags and it causes
a server to reject re-open requests because create options
don't match. The latter means that any subsequent system
call against that open file fail until a share is re-mounted.

Fix this by properly setting SMB create options when
re-openning files after reconnects.

Fixes: 1013e760d10e6: ("SMB3: Don't ignore O_SYNC/O_DSYNC and O_DIRECT flags")
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 038a810418d898776a26e17ed75ba59a811da8ef..5daa97d19ad192dab73da47000e7392126487539 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -711,6 +711,13 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
        if (backup_cred(cifs_sb))
                create_options |= CREATE_OPEN_BACKUP_INTENT;
 
+       /* O_SYNC also has bit for O_DSYNC so following check picks up either */
+       if (cfile->f_flags & O_SYNC)
+               create_options |= CREATE_WRITE_THROUGH;
+
+       if (cfile->f_flags & O_DIRECT)
+               create_options |= CREATE_NO_BUFFER;
+
        if (server->ops->get_lease_key)
                server->ops->get_lease_key(inode, &cfile->fid);