c28ba74c67
[ Upstream commit 10157b1fc1a762293381e9145041253420dfc6ad ] When a host is configured with a few LUNs and I/O is running, injecting FC faults repeatedly leads to path recovery problems. The LUNs have 4 paths each and 3 of them come back active after say an FC fault which makes 2 of the paths go down, instead of all 4. This happens after several iterations of continuous FC faults. Reason here is that we're returning an I/O error whenever we're encountering sense code 06/04/0a (LOGICAL UNIT NOT ACCESSIBLE, ASYMMETRIC ACCESS STATE TRANSITION) instead of retrying. [mwilck: The original patch was developed by Rajashekhar M A and Hannes Reinecke. I moved the code to alua_check_sense() as suggested by Mike Christie [1]. Evan Milne had raised the question whether pg->state should be set to transitioning in the UA case [2]. I believe that doing this is correct. SCSI_ACCESS_STATE_TRANSITIONING by itself doesn't cause I/O errors. Our handler schedules an RTPG, which will only result in an I/O error condition if the transitioning timeout expires.] [1] https://lore.kernel.org/all/0bc96e82-fdda-4187-148d-5b34f81d4942@oracle.com/ [2] https://lore.kernel.org/all/CAGtn9r=kicnTDE2o7Gt5Y=yoidHYD7tG8XdMHEBJTBraVEoOCw@mail.gmail.com/ Co-developed-by: Rajashekhar M A <rajs@netapp.com> Co-developed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin Wilck <martin.wilck@suse.com> Link: https://lore.kernel.org/r/20240514140344.19538-1-mwilck@suse.com Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@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.