Linux 3.14 compat: rq_for_each_segment in dmu_req_copy

rq_for_each_segment changed from taking bio_vec * to taking bio_vec.
We provide rq_for_each_segment4 which takes both.

Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2124
This commit is contained in:
Chunwei Chen 2014-03-29 20:26:17 +08:00 committed by Brian Behlendorf
parent 22760eebef
commit b761912b34
3 changed files with 56 additions and 8 deletions

View File

@ -1,10 +1,13 @@
dnl #
dnl # 2.6.x API change
dnl #
dnl # 3.14 API change
dnl #
AC_DEFUN([ZFS_AC_KERNEL_RQ_FOR_EACH_SEGMENT], [
AC_MSG_CHECKING([whether rq_for_each_segment() is available])
tmp_flags="$EXTRA_KCFLAGS"
EXTRA_KCFLAGS="${NO_UNUSED_BUT_SET_VARIABLE}"
AC_MSG_CHECKING([whether rq_for_each_segment() wants bio_vec *])
ZFS_LINUX_TRY_COMPILE([
#include <linux/blkdev.h>
],[
@ -16,8 +19,29 @@ AC_DEFUN([ZFS_AC_KERNEL_RQ_FOR_EACH_SEGMENT], [
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_RQ_FOR_EACH_SEGMENT, 1,
[rq_for_each_segment() is available])
AC_DEFINE(HAVE_RQ_FOR_EACH_SEGMENT_BVP, 1,
[rq_for_each_segment() wants bio_vec *])
],[
AC_MSG_RESULT(no)
])
AC_MSG_CHECKING([whether rq_for_each_segment() wants bio_vec])
ZFS_LINUX_TRY_COMPILE([
#include <linux/blkdev.h>
],[
struct bio_vec bv;
struct req_iterator iter;
struct request *req = NULL;
rq_for_each_segment(bv, req, iter) { }
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_RQ_FOR_EACH_SEGMENT, 1,
[rq_for_each_segment() is available])
AC_DEFINE(HAVE_RQ_FOR_EACH_SEGMENT_BV, 1,
[rq_for_each_segment() wants bio_vec])
],[
AC_MSG_RESULT(no)
])
EXTRA_KCFLAGS="$tmp_flags"
])

View File

@ -284,8 +284,32 @@ struct req_iterator {
#define rq_for_each_segment(bvl, _rq, _iter) \
__rq_for_each_bio(_iter.bio, _rq) \
bio_for_each_segment(bvl, _iter.bio, _iter.i)
#define HAVE_RQ_FOR_EACH_SEGMENT_BVP 1
#endif /* HAVE_RQ_FOR_EACH_SEGMENT */
/*
* 3.14 API change
* rq_for_each_segment changed from taking bio_vec * to taking bio_vec.
* We provide rq_for_each_segment4 which takes both.
* You should not modify the fields in @bv and @bvp.
*
* Note: the if-else is just to inject the assignment before the loop body.
*/
#ifdef HAVE_RQ_FOR_EACH_SEGMENT_BVP
#define rq_for_each_segment4(bv, bvp, rq, iter) \
rq_for_each_segment(bvp, rq, iter) \
if ((bv = *bvp), 0) \
; \
else
#else
#define rq_for_each_segment4(bv, bvp, rq, iter) \
rq_for_each_segment(bv, rq, iter) \
if ((bvp = &bv), 0) \
; \
else
#endif
#ifdef HAVE_BIO_BVEC_ITER
#define BIO_BI_SECTOR(bio) (bio)->bi_iter.bi_sector
#define BIO_BI_SIZE(bio) (bio)->bi_iter.bi_size

View File

@ -1011,13 +1011,13 @@ xuio_stat_wbuf_nocopy()
static int
dmu_req_copy(void *arg_buf, int size, struct request *req, size_t req_offset)
{
struct bio_vec *bv;
struct bio_vec bv, *bvp;
struct req_iterator iter;
char *bv_buf;
int tocpy, bv_len, bv_offset;
int offset = 0;
rq_for_each_segment(bv, req, iter) {
rq_for_each_segment4(bv, bvp, req, iter) {
/*
* Fully consumed the passed arg_buf. We use goto here because
* rq_for_each_segment is a double loop
@ -1027,19 +1027,19 @@ dmu_req_copy(void *arg_buf, int size, struct request *req, size_t req_offset)
goto out;
/* Skip already copied bv */
if (req_offset >= bv->bv_len) {
req_offset -= bv->bv_len;
if (req_offset >= bv.bv_len) {
req_offset -= bv.bv_len;
continue;
}
bv_len = bv->bv_len - req_offset;
bv_offset = bv->bv_offset + req_offset;
bv_len = bv.bv_len - req_offset;
bv_offset = bv.bv_offset + req_offset;
req_offset = 0;
tocpy = MIN(bv_len, size - offset);
ASSERT3S(tocpy, >=, 0);
bv_buf = page_address(bv->bv_page) + bv_offset;
bv_buf = page_address(bv.bv_page) + bv_offset;
ASSERT3P(bv_buf, !=, NULL);
if (rq_data_dir(req) == WRITE)