copy_data currently loops over bio's in a list, but the
caller also does the same looping, sometimes with extra work.
So remove the loop from copy_data.
Signed-off-by: Neil Brown <neilb@xxxxxxxxxxxxxxx>
### Diffstat output
./drivers/md/raid5.c | 72 ++++++++++++++++++++++-------------------------
./drivers/md/raid6main.c | 65 ++++++++++++++++++++----------------------
2 files changed, 65 insertions(+), 72 deletions(-)
diff ./drivers/md/raid5.c~current~ ./drivers/md/raid5.c
--- ./drivers/md/raid5.c~current~ 2005-02-07 13:31:05.000000000 +1100
+++ ./drivers/md/raid5.c 2005-02-07 13:34:09.000000000 +1100
@@ -613,11 +613,10 @@ static sector_t compute_blocknr(struct s
/*
- * Copy data between a page in the stripe cache, and one or more bion
- * The page could align with the middle of the bio, or there could be
- * several bion, each with several bio_vecs, which cover part of the page
- * Multiple bion are linked together on bi_next. There may be extras
- * at the end of this list. We ignore them.
+ * Copy data between a page in the stripe cache, and a bio.
+ * There are no alignment or size guarantees between the page or the
+ * bio except that there is some overlap.
+ * All iovecs in the bio must be considered.
*/
static void copy_data(int frombio, struct bio *bio,
struct page *page,
@@ -626,41 +625,38 @@ static void copy_data(int frombio, struc
char *pa = page_address(page);
struct bio_vec *bvl;
int i;
+ int page_offset;
- for (;bio && bio->bi_sector < sector+STRIPE_SECTORS;
- bio = r5_next_bio(bio, sector) ) {
- int page_offset;
- if (bio->bi_sector >= sector)
- page_offset = (signed)(bio->bi_sector - sector) * 512;
- else
- page_offset = (signed)(sector - bio->bi_sector) * -512;
- bio_for_each_segment(bvl, bio, i) {
- int len = bio_iovec_idx(bio,i)->bv_len;
- int clen;
- int b_offset = 0;
-
- if (page_offset < 0) {
- b_offset = -page_offset;
- page_offset += b_offset;
- len -= b_offset;
- }
-
- if (len > 0 && page_offset + len > STRIPE_SIZE)
- clen = STRIPE_SIZE - page_offset;
- else clen = len;
+ if (bio->bi_sector >= sector)
+ page_offset = (signed)(bio->bi_sector - sector) * 512;
+ else
+ page_offset = (signed)(sector - bio->bi_sector) * -512;
+ bio_for_each_segment(bvl, bio, i) {
+ int len = bio_iovec_idx(bio,i)->bv_len;
+ int clen;
+ int b_offset = 0;
+
+ if (page_offset < 0) {
+ b_offset = -page_offset;
+ page_offset += b_offset;
+ len -= b_offset;
+ }
+
+ if (len > 0 && page_offset + len > STRIPE_SIZE)
+ clen = STRIPE_SIZE - page_offset;
+ else clen = len;
- if (clen > 0) {
- char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
- if (frombio)
- memcpy(pa+page_offset, ba+b_offset, clen);
- else
- memcpy(ba+b_offset, pa+page_offset, clen);
- __bio_kunmap_atomic(ba, KM_USER0);
- }
- if (clen < len) /* hit end of page */
- break;
- page_offset += len;
- }
+ if (clen > 0) {
+ char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
+ if (frombio)
+ memcpy(pa+page_offset, ba+b_offset, clen);
+ else
+ memcpy(ba+b_offset, pa+page_offset, clen);
+ __bio_kunmap_atomic(ba, KM_USER0);
+ }
+ if (clen < len) /* hit end of page */
+ break;
+ page_offset += len;
}
}
diff ./drivers/md/raid6main.c~current~ ./drivers/md/raid6main.c
--- ./drivers/md/raid6main.c~current~ 2005-02-07 13:31:05.000000000 +1100
+++ ./drivers/md/raid6main.c 2005-02-07 13:34:09.000000000 +1100
@@ -670,41 +670,38 @@ static void copy_data(int frombio, struc
char *pa = page_address(page);
struct bio_vec *bvl;
int i;
+ int page_offset;
- for (;bio && bio->bi_sector < sector+STRIPE_SECTORS;
- bio = r5_next_bio(bio, sector) ) {
- int page_offset;
- if (bio->bi_sector >= sector)
- page_offset = (signed)(bio->bi_sector - sector) * 512;
- else
- page_offset = (signed)(sector - bio->bi_sector) * -512;
- bio_for_each_segment(bvl, bio, i) {
- int len = bio_iovec_idx(bio,i)->bv_len;
- int clen;
- int b_offset = 0;
-
- if (page_offset < 0) {
- b_offset = -page_offset;
- page_offset += b_offset;
- len -= b_offset;
- }
-
- if (len > 0 && page_offset + len > STRIPE_SIZE)
- clen = STRIPE_SIZE - page_offset;
- else clen = len;
-
- if (clen > 0) {
- char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
- if (frombio)
- memcpy(pa+page_offset, ba+b_offset, clen);
- else
- memcpy(ba+b_offset, pa+page_offset, clen);
- __bio_kunmap_atomic(ba, KM_USER0);
- }
- if (clen < len) /* hit end of page */
- break;
- page_offset += len;
- }
+ if (bio->bi_sector >= sector)
+ page_offset = (signed)(bio->bi_sector - sector) * 512;
+ else
+ page_offset = (signed)(sector - bio->bi_sector) * -512;
+ bio_for_each_segment(bvl, bio, i) {
+ int len = bio_iovec_idx(bio,i)->bv_len;
+ int clen;
+ int b_offset = 0;
+
+ if (page_offset < 0) {
+ b_offset = -page_offset;
+ page_offset += b_offset;
+ len -= b_offset;
+ }
+
+ if (len > 0 && page_offset + len > STRIPE_SIZE)
+ clen = STRIPE_SIZE - page_offset;
+ else clen = len;
+
+ if (clen > 0) {
+ char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
+ if (frombio)
+ memcpy(pa+page_offset, ba+b_offset, clen);
+ else
+ memcpy(ba+b_offset, pa+page_offset, clen);
+ __bio_kunmap_atomic(ba, KM_USER0);
+ }
+ if (clen < len) /* hit end of page */
+ break;
+ page_offset += len;
}
}
-
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