mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-08 08:02:59 -04:00
9571f829f3
It was reported that the "generic/250" test in xfstests (which uses the dm-error target) demonstrates a regression where the kernel crashes in bioset_exit(). Since commitcfc97abcbe("dm: conditionally enable BIOSET_PERCPU_CACHE for dm_io bioset") the bioset_init() for the dm_io bioset will setup the bioset's per-cpu alloc cache if all devices have QUEUE_FLAG_POLL set. But there was an bug where a target that doesn't have any data devices (and that doesn't even set the .iterate_devices dm target callback) will incorrectly return true from dm_table_supports_poll(). Fix this by updating dm_table_supports_poll() to follow dm-table.c's well-worn pattern for testing that _all_ targets in a DM table do in fact have underlying devices that set QUEUE_FLAG_POLL. NOTE: An additional block fix is still needed so that bio_alloc_cache_destroy() clears the bioset's ->cache member. Otherwise, a DM device's table reload that transitions the DM device's bioset from using a per-cpu alloc cache to _not_ using one will result in bioset_exit() crashing in bio_alloc_cache_destroy() because dm's dm_io bioset ("io_bs") was left with a stale ->cache member. Fixes:cfc97abcbe("dm: conditionally enable BIOSET_PERCPU_CACHE for dm_io bioset") Reported-by: Matthew Wilcox <willy@infradead.org> Reported-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Mike Snitzer <snitzer@kernel.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.
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.