From: Ben Slusky <sluskyb@paranoiacs.org>
Contains the bio indexing fixes that are already in the -mm patch, plus some
similarly trivial fixes in the block-backed code. Basically the loop driver
assumes that all bio's have allocated pages starting at index 0 in the
bio_vec. In practice this assumption works but there's no reason why it
should, and recycling bio's will ruin it completely anyway.
drivers/block/loop.c | 26 ++++++++++++--------------
1 files changed, 12 insertions(+), 14 deletions(-)
diff -puN drivers/block/loop.c~loop-bio-index-fix drivers/block/loop.c
--- 25/drivers/block/loop.c~loop-bio-index-fix 2003-12-29 22:31:35.000000000 -0800
+++ 25-akpm/drivers/block/loop.c 2003-12-29 22:31:35.000000000 -0800
@@ -247,12 +247,10 @@ fail:
static int
lo_send(struct loop_device *lo, struct bio *bio, int bsize, loff_t pos)
{
- unsigned vecnr;
- int ret = 0;
-
- for (vecnr = 0; vecnr < bio->bi_vcnt; vecnr++) {
- struct bio_vec *bvec = &bio->bi_io_vec[vecnr];
+ struct bio_vec *bvec;
+ int i, ret = 0;
+ bio_for_each_segment(bvec, bio, i) {
ret = do_lo_send(lo, bvec, bsize, pos);
if (ret < 0)
break;
@@ -318,12 +316,10 @@ do_lo_receive(struct loop_device *lo,
static int
lo_receive(struct loop_device *lo, struct bio *bio, int bsize, loff_t pos)
{
- unsigned vecnr;
- int ret = 0;
-
- for (vecnr = 0; vecnr < bio->bi_vcnt; vecnr++) {
- struct bio_vec *bvec = &bio->bi_io_vec[vecnr];
+ struct bio_vec *bvec;
+ int i, ret = 0;
+ bio_for_each_segment(bvec, bio, i) {
ret = do_lo_receive(lo, bvec, bsize, pos);
if (ret < 0)
break;
@@ -353,10 +349,11 @@ static void loop_put_buffer(struct bio *
* check bi_end_io, may just be a remapped bio
*/
if (bio && bio->bi_end_io == loop_end_io_transfer) {
+ struct bio_vec *bv;
int i;
- for (i = 0; i < bio->bi_vcnt; i++)
- __free_page(bio->bi_io_vec[i].bv_page);
+ bio_for_each_segment(bv, bio, i)
+ __free_page(bv->bv_page);
bio_put(bio);
}
@@ -437,7 +434,7 @@ static struct bio *loop_copy_bio(struct
/*
* iterate iovec list and alloc pages
*/
- __bio_for_each_segment(bv, rbh, i, 0) {
+ bio_for_each_segment(bv, rbh, i) {
struct bio_vec *bbv = &bio->bi_io_vec[i];
bbv->bv_page = alloc_page(__GFP_NOWARN|__GFP_HIGHMEM);
@@ -448,6 +445,7 @@ static struct bio *loop_copy_bio(struct
bbv->bv_offset = bv->bv_offset;
}
+ bio->bi_idx = rbh->bi_idx;
bio->bi_vcnt = rbh->bi_vcnt;
bio->bi_size = rbh->bi_size;
@@ -502,7 +500,7 @@ static int loop_transfer_bio(struct loop
IV = from_bio->bi_sector + (lo->lo_offset >> 9);
- __bio_for_each_segment(from_bvec, from_bio, i, 0) {
+ bio_for_each_segment(from_bvec, from_bio, i) {
to_bvec = &to_bio->bi_io_vec[i];
kmap(from_bvec->bv_page);
_