[PATCH 15/17] md: raid10: avoid direct access to bvec table in fix_recovery_read_error

Ming Lei
2017-02-16T11:47:07Z

The cost is 128bytes(8*16) stack space in kernel thread context, and just
use the bio helper to retrieve pages from bio.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
drivers/md/raid10.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 69fe2a3cef89..c7d2f73565d9 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2184,6 +2184,11 @@ static void fix_recovery_read_error(struct r10bio *r10_bio)
int idx = 0;
int dr = r10_bio->devs[0].devnum;
int dw = r10_bio->devs[1].devnum;
+ struct bio_vec *bvl;
+ struct page *pages[RESYNC_PAGES];
+
+ bio_for_each_segment_all(bvl, bio, idx)
+ pages[idx] = bvl->bv_page;

while (sectors) {
int s = sectors;
@@ -2199,7 +2204,7 @@ static void fix_recovery_read_error(struct r10bio *r10_bio)
ok = sync_page_io(rdev,
addr,
s << 9,
- bio->bi_io_vec[idx].bv_page,
+ pages[idx],
REQ_OP_READ, 0, false);
if (ok) {
rdev = conf->mirrors[dw].rdev;
@@ -2207,7 +2212,7 @@ static void fix_recovery_read_error(struct r10bio *r10_bio)
ok = sync_page_io(rdev,
addr,
s << 9,
- bio->bi_io_vec[idx].bv_page,
+ pages[idx],
REQ_OP_WRITE, 0, false);
if (!ok) {
set_bit(WriteErrorSeen, &rdev->flags);
--
2.7.4