From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 5 Dec 2012 11:08:29 +0000 (+0100)
Subject: target/file: Fix 32-bit highmem breakage for SGL -> iovec mapping
X-Git-Tag: v3.2.36~66
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1506cb20191c0b33ae0c6cedac7a0ebf4fee3cf7;p=pandora-kernel.git

target/file: Fix 32-bit highmem breakage for SGL -> iovec mapping

commit 40ff2c3b3da35dd3a00ac6722056a59b4b3f2caf upstream.

This patch changes vectored file I/O to use kmap + kunmap when mapping
incoming SGL memory -> struct iovec in order to properly support 32-bit
highmem configurations.  This is because an extra bounce buffer may be
required when processing scatterlist pages allocated with GFP_KERNEL.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
[bwh: Backported to 3.2: use task->task_sg{,_nents} for iteration]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

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