xen-blkback: check the number of iovecs before allocating a bios

With the introduction of indirect segments we can receive requests
with a number of segments bigger than the maximum number of allowed
iovecs in a bios, so make sure that blkback doesn't try to allocate a
bios with more iovecs than BIO_MAX_PAGES

Signed-off-by: Roger Pau Monné <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
This commit is contained in:
Roger Pau Monne 2013-06-22 09:59:17 +02:00 • committed by Konrad Rzeszutek Wilk
commit 1e0f7a21b2

View file

@ -1247,7 +1247,8 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
seg[i].nsec << 9,
seg[i].offset) == 0)) {
bio = bio_alloc(GFP_KERNEL, nseg-i);
int nr_iovecs = min_t(int, (nseg-i), BIO_MAX_PAGES);
bio = bio_alloc(GFP_KERNEL, nr_iovecs);
if (unlikely(bio == NULL))
goto fail_put_bio;