644c9f40cf
If a write delegation isn't available, the Linux NFS client uses a zero-stateid when performing a SETATTR. NFSv4.0 provides no mechanism for an NFS server to match such a request to a particular client. It recalls all delegations for that file, even delegations held by the client issuing the request. If that client happens to hold a read delegation, the server will recall it immediately, resulting in an NFS4ERR_DELAY/CB_RECALL/ DELEGRETURN sequence. Optimize out this pipeline bubble by having the client return any delegations it may hold on a file before it issues a SETATTR(zero-stateid) on that file. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.