From 50bed2e2862a8f3a4f7d683d0d27292e71ef18b9 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Thu, 11 Sep 2008 18:35:39 +0200 Subject: [PATCH] sg: disable interrupts inside sg_copy_buffer 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 --- lib/scatterlist.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/scatterlist.c b/lib/scatterlist.c index 876ba6d5b67..8d2688ff135 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -422,9 +422,12 @@ static size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, { unsigned int offset = 0; struct sg_mapping_iter miter; + unsigned long flags; sg_miter_start(&miter, sgl, nents, SG_MITER_ATOMIC); + local_irq_save(flags); + while (sg_miter_next(&miter) && offset < buflen) { unsigned int len; @@ -442,6 +445,7 @@ static size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, sg_miter_stop(&miter); + local_irq_restore(flags); return offset; }