[PATCH 03/15] block: bio-integrity: modify bio_integrity_add_page()

Jinyoung CHOI
2023-05-03T10:06:52Z

Considering the constraints of hardware, the physically continuous pages
were to be composed of one bio_vec.

Previously, bio_vec was created separately for each page entering the
parameter.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>

Fixes: 783b94bd9250 ("nvme-pci: do not build a scatterlist to map metadata")
Signed-off-by: Jinyoung Choi <j-young.choi@samsung.com>
---
block/bio-integrity.c | 41 +++++++++++++++++++++++++++--------------
1 file changed, 27 insertions(+), 14 deletions(-)

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index 06b6a2c178d2..74cf9933c285 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -176,25 +176,45 @@ static bool bip_try_merge_hw_seg(struct request_queue *q,
* @len: number of bytes of integrity metadata in page
* @offset: start offset within page
*
- * Description: Attach a page containing integrity metadata to bio.
+ * Add a page containing integrity metadata to a bio while respecting
+ * the hardware max_sectors, max_segment and gap limitations.
*/
int bio_integrity_add_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int offset)
{
+ struct request_queue *q = bdev_get_queue(bio->bi_bdev);
struct bio_integrity_payload *bip = bio_integrity(bio);

- if (bip->bip_vcnt >= bip->bip_max_vcnt) {
+ if (((bip->bip_iter.bi_size + len) >> 9) > queue_max_hw_sectors(q))
+ return 0;
+
+ if (bip->bip_vcnt > 0) {
+ struct bio_vec *bv;
+ bool same_page = false;
+
+ if (bip_try_merge_hw_seg(q, bip, page, len, offset, &same_page))
+ return len;
+
+ /*
+ * If the queue doesn't support SG gaps and adding this segment
+ * would create a gap, disallow it.
+ */
+ bv = &bip->bip_vec[bip->bip_vcnt - 1];
+ if (bvec_gap_to_prev(&q->limits, bv, offset))
+ return 0;
+ }
+
+ if (bip_full(bip, len)) {
printk(KERN_ERR "%s: bip_vec full\n", __func__);
return 0;
}

- if (bip->bip_vcnt &&
- bvec_gap_to_prev(&bdev_get_queue(bio->bi_bdev)->limits,
- &bip->bip_vec[bip->bip_vcnt - 1], offset))
+ if (bip->bip_vcnt >= queue_max_integrity_segments(q))
return 0;

bvec_set_page(&bip->bip_vec[bip->bip_vcnt], page, len, offset);
bip->bip_vcnt++;
+ bip->bip_iter.bi_size += len;

return len;
}
@@ -307,7 +327,6 @@ bool bio_integrity_prep(struct bio *bio)
}

bip->bip_flags |= BIP_BLOCK_INTEGRITY;
- bip->bip_iter.bi_size = len;
bip_set_seed(bip, bio->bi_iter.bi_sector);

if (bi->flags & BLK_INTEGRITY_IP_CHECKSUM)
@@ -316,7 +335,6 @@ bool bio_integrity_prep(struct bio *bio)
/* Map it */
offset = offset_in_page(buf);
for (i = 0 ; i < nr_pages ; i++) {
- int ret;
bytes = PAGE_SIZE - offset;

if (len <= 0)
@@ -325,18 +343,13 @@ bool bio_integrity_prep(struct bio *bio)
if (bytes > len)
bytes = len;

- ret = bio_integrity_add_page(bio, virt_to_page(buf),
- bytes, offset);
-
- if (ret == 0) {
+ if (bio_integrity_add_page(bio, virt_to_page(buf),
+ bytes, offset) < bytes) {
printk(KERN_ERR "could not attach integrity payload\n");
status = BLK_STS_RESOURCE;
goto err_end_io;
}

- if (ret < bytes)
- break;
-
buf += bytes;
len -= bytes;
offset = 0;
--
2.34.1