33336c1805
When qgroups are enabled, during data reservation, we allocate the ulist_nodes that track the exact reserved extents with GFP_ATOMIC unconditionally. This is unnecessary, and we can follow the model already employed by the struct extent_state we preallocate in the non qgroups case, which should reduce the risk of allocation failures with GFP_ATOMIC. Add a prealloc node to struct ulist which ulist_add will grab when it is present, and try to allocate it before taking the tree lock while we can still take advantage of a less strict gfp mask. The lifetime of that node belongs to the new prealloc field, until it is used, at which point it belongs to the ulist linked list. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.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 reStructuredText 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.