From: FUJITA Tomonori Date: Fri, 12 Sep 2008 16:16:45 +0000 (+0900) Subject: sg: disable interrupts inside sg_copy_buffer X-Git-Tag: v2.6.26.6~46 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e568b3605f6f6ad1e9cbe37231cf5b578ff16d4b;p=thirdparty%2Fkernel%2Fstable.git sg: disable interrupts inside sg_copy_buffer This is the backport of the upstream commit 50bed2e2862a8f3a4f7d683d0d27292e71ef18b9 The callers of sg_copy_buffer must disable interrupts before calling it (since it uses kmap_atomic). Some callers use it on interrupt-disabled code but some need to take the trouble to disable interrupts just for this. No wonder they forget about it and we hit a bug like: http://bugzilla.kernel.org/show_bug.cgi?id=11529 James said that it might be better to disable interrupts inside the function rather than risk the callers getting it wrong. Signed-off-by: FUJITA Tomonori Signed-off-by: Jens Axboe Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman --- diff --git a/lib/scatterlist.c b/lib/scatterlist.c index b80c21100d783..8c11004ac347c 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -312,8 +312,9 @@ static size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, struct scatterlist *sg; size_t buf_off = 0; int i; + unsigned long flags; - WARN_ON(!irqs_disabled()); + local_irq_save(flags); for_each_sg(sgl, sg, nents, i) { struct page *page; @@ -358,6 +359,8 @@ static size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, break; } + local_irq_restore(flags); + return buf_off; }