f63955721a
We are not allowed to call pnfs_mark_matching_lsegs_return() without
also holding a reference to the layout header, since doing so could lead
to the reference count going to zero when we call
pnfs_layout_remove_lseg(). This again can lead to a hang when we get to
nfs4_evict_inode() and are unable to clear the layout pointer.
pnfs_layout_return_unused_byserver() is guilty of this behaviour, and
has been seen to trigger the refcount warning prior to a hang.
Fixes: b6d49ecd1081 ("NFSv4: Fix a pNFS layout related use-after-free race when freeing the inode")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.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.