Hi, Once every few runs, we see the DFS tests failing in buildbot. I did some digging into this, and here's my conclusion. Please let me know if you can point out some issue with the root cause or the fix. There is a race condition that exists between cifsd and I/O threads when the tcp connection is broken. The cifsd thread marks the server/session/tcon structures for reconnect, and recreates the socket, and sets 1 credit for this server. This only changes after the next negotiate/session-setup completes, where it can get more credits. During this window, if any ongoing I/O requires more than 1 credit, then it will return with smb3_insufficient_credits (note that slightly earlier in the same code, we identify reconnect with smb3_reconnect_detected, but do nothing about it). The I/O will now leak -EHOSTDOWN or -EAGAIN into userspace. I feel that we should return a special error (-ERESTARTSYS?) when smb3_reconnect_detected, and use this errno to ask the caller to restart the syscall. Ronnie/Pavel/Paulo: Please let me know what you think about this. -- Regards, Shyam
