SMB3: Work around mount failure when using SMB3 dialect to Macs

[karo-tx-linux.git] / fs / cifs / smb2pdu.c

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 02da648041fcd58d6e37431a60d596a5bfd4ca06..0fd63f0bc4408e77b8b81fa9bd46c3fa8dcc752e 100644 (file)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -632,8 +632,12 @@ int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon)
        }
 
        if (rsplen != sizeof(struct validate_negotiate_info_rsp)) {
-               cifs_dbg(VFS, "invalid size of protocol negotiate response\n");
-               return -EIO;
+               cifs_dbg(VFS, "invalid protocol negotiate response size: %d\n",
+                        rsplen);
+
+               /* relax check since Mac returns max bufsize allowed on ioctl */
+               if (rsplen > CIFSMaxBufSize)
+                       return -EIO;
        }
 
        /* check validate negotiate info response matches what we got earlier */
@@ -1853,8 +1857,12 @@ SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
         * than one credit. Windows typically sets this smaller, but for some
         * ioctls it may be useful to allow server to send more. No point
         * limiting what the server can send as long as fits in one credit
+        * Unfortunately - we can not handle more than CIFS_MAX_MSG_SIZE
+        * (by default, note that it can be overridden to make max larger)
+        * in responses (except for read responses which can be bigger.
+        * We may want to bump this limit up
         */
-       req->MaxOutputResponse = cpu_to_le32(0xFF00); /* < 64K uses 1 credit */
+       req->MaxOutputResponse = cpu_to_le32(CIFSMaxBufSize);
 
        if (is_fsctl)
                req->Flags = cpu_to_le32(SMB2_0_IOCTL_IS_FSCTL);