d082dc1562
The existing code to carve up the sg list expected an sg element-per-page
which can be very incorrect with iommu's remapping multiple memory pages
to fewer bus addresses. To hit this error required a large io payload
(greater than 256k) and a system that maps on a per-page basis. It's
possible that large ios could get by fine if the system condensed the
sgl list into the first 64 elements.
This patch corrects the sg list handling by specifically walking the
sg list element by element and attempting to divide the transfer up
on a per-sg element boundary. While doing so, it still tries to keep
sequences under 256k, but will exceed that rule if a single sg element
is larger than 256k.
Fixes: 48fa362b6c3f ("nvmet-fc: simplify sg list handling")
Cc: <stable@vger.kernel.org> # 4.14
Signed-off-by: James Smart <james.smart@broadcom.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.
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.