dbc626597c
Currently device_supports_dax() just checks to see if the QUEUE_FLAG_DAX
flag is set on the device's request queue to decide whether or not the
device supports filesystem DAX. Really we should be using
bdev_dax_supported() like filesystems do at mount time. This performs
other tests like checking to make sure the dax_direct_access() path works.
We also explicitly clear QUEUE_FLAG_DAX on the DM device's request queue if
any of the underlying devices do not support DAX. This makes the handling
of QUEUE_FLAG_DAX consistent with the setting/clearing of most other flags
in dm_table_set_restrictions().
Now that bdev_dax_supported() explicitly checks for QUEUE_FLAG_DAX, this
will ensure that filesystems built upon DM devices will only be able to
mount with DAX if all underlying devices also support DAX.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Fixes: commit 545ed20e6df6 ("dm: add infrastructure for DAX support")
Cc: stable@vger.kernel.org
Acked-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.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.
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.