7ffb6a7ec6
The recent nocow locking rework introduced a deadlock in the data move path: the new nocow locking scheme uses a hash table with a fixed size array for chaining, meaning on hash collision we may have to wait for other locks to be released before we can lock a bucket. And since the data move path needs to submit writes from the same thread that's taking nocow locks and submitting reads, this introduces a deadlock. This shouldn't happen often in practice, but since the data move path can keep large numbers of IOs in flight simultaneously, it's something we have to handle. This patch makes move_ctxt_wait_event() available to bch2_data_update_init() and uses it when appropriate, which is our normal solution to this kind of thing. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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.