055ed193b1
The pools hashtable can be implemented using the rhashtable implementation in lib. This has the benefit that lookups are lock-free. We need to use kfree_rcu() to free a pool so that a lookup racing with a deletion will not access freed memory. rhashtable has no combined lookup-and-delete interface, but as the lookup is lockless and the chains are short, this brings little cost. Even if a lookup finds a pool, we must be prepared for the delete to fail to find it, as we might race with another thread doing a delete. We use atomic_inc_not_zero() after finding a pool in the hash table and if that fails, we must have raced with a deletion, so we treat the lookup as a failure. Use hashlen_string() rather than a hand-crafted hash function. Note that the pool_name, and the search key, are guaranteed to be nul terminated. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.