Messages in this thread Patch in this message | | | Date | Mon, 6 Oct 2008 17:38:33 -0700 | From | Greg KH <> | Subject | [patch 26/71] sg: disable interrupts inside sg_copy_buffer |
| |
2.6.26-stable review patch. If anyone has any objections, please let us know.
------------------ From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
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 <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- lib/scatterlist.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -312,8 +312,9 @@ static size_t sg_copy_buffer(struct scat 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 scat break; } + local_irq_restore(flags); + return buf_off; } --
| |