crypto: af_alg - Allow to link sgl

Allow to link af_alg sgls.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tadeusz Struk 2015-03-19 12:31:30 -07:00 committed by David S. Miller
parent 0345f93138
commit 66db37391d
2 changed files with 16 additions and 6 deletions

View File

@ -358,8 +358,8 @@ int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
if (WARN_ON(npages == 0))
return -EINVAL;
sg_init_table(sgl->sg, npages);
/* Add one extra for linking */
sg_init_table(sgl->sg, npages + 1);
for (i = 0, len = n; i < npages; i++) {
int plen = min_t(int, len, PAGE_SIZE - off);
@ -369,18 +369,26 @@ int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
off = 0;
len -= plen;
}
sg_mark_end(sgl->sg + npages - 1);
sgl->npages = npages;
return n;
}
EXPORT_SYMBOL_GPL(af_alg_make_sg);
void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new)
{
sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
}
EXPORT_SYMBOL(af_alg_link_sg);
void af_alg_free_sg(struct af_alg_sgl *sgl)
{
int i;
i = 0;
do {
for (i = 0; i < sgl->npages; i++)
put_page(sgl->pages[i]);
} while (!sg_is_last(sgl->sg + (i++)));
}
EXPORT_SYMBOL_GPL(af_alg_free_sg);

View File

@ -58,8 +58,9 @@ struct af_alg_type {
};
struct af_alg_sgl {
struct scatterlist sg[ALG_MAX_PAGES];
struct scatterlist sg[ALG_MAX_PAGES + 1];
struct page *pages[ALG_MAX_PAGES];
unsigned int npages;
};
int af_alg_register_type(const struct af_alg_type *type);
@ -70,6 +71,7 @@ int af_alg_accept(struct sock *sk, struct socket *newsock);
int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len);
void af_alg_free_sg(struct af_alg_sgl *sgl);
void af_alg_link_sg(struct af_alg_sgl *sgl_prev, struct af_alg_sgl *sgl_new);
int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con);