Re: [PATCH 4/4] cifs: make retry logic in read/write path consistent with other paths

[David Howells <dhowells@redhat.com>]

David Howells <dhowells@redhat.com> wrote:

> Better to offload the pause to netfslib if we can.

I would suggest you look at doing it in netfs_retry_writes().  Something like:

 (1) Add a timestamp to netfs_io_request to record either the first op being
     issued or the last op being issued.

 (2) After netfs_retry_writes() finishes waiting for subreqs to quiesce, wait
     for the requisite amount of time since the timestamp recorded in (1)
     before continuing the retry.

 (3) Add a method to netfs_request_ops to allow netfslib to ask the filesystem
     what backoff delay it wants to insert.  This could call
     smb2_should_replay().

Alternatively, set a flag on cifs_io_request indicating backoff is required
and do it in cifs_prepare_write() before waiting for credits if the flag is
set - or maybe in cifs_issue_write() - at which point clear the flag.

David