150dfb6c83
By default, we set the passthru request allocation flag such that it returns the error in the following code path and we fail the I/O when BLK_MQ_REQ_NOWAIT is used for request allocation :- nvme_alloc_request() blk_mq_alloc_request() blk_mq_queue_enter() if (flag & BLK_MQ_REQ_NOWAIT) return -EBUSY; <-- return if busy. On some controllers using BLK_MQ_REQ_NOWAIT ends up in I/O error where the controller is perfectly healthy and not in a degraded state. Block layer request allocation does allow us to wait instead of immediately returning the error when we BLK_MQ_REQ_NOWAIT flag is not used. This has shown to fix the I/O error problem reported under heavy random write workload. Remove the BLK_MQ_REQ_NOWAIT parameter for passthru request allocation which resolves this issue. Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
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.