2 files changed, 26 insertions(+)
fs/bio.c | 24 ++++++++++++++++++++++++
include/linux/bio.h | 2 ++
Helper function to find the sector offset in a bio given bvec index
and page offset.
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
---
diff -r 550d61001baa -r 318fa71e735d fs/bio.c
--- a/fs/bio.c Sat Jun 07 00:45:14 2008 -0400
+++ b/fs/bio.c Sat Jun 07 00:45:14 2008 -0400
@@ -1232,6 +1232,30 @@
return bp;
}
+sector_t bio_sector_offset(struct bio *bio, unsigned short index, unsigned int offset)
+{
+ struct bio_vec *bv;
+ unsigned int sector_sz = bio->bi_bdev->bd_disk->queue->hardsect_size;
+ sector_t sectors;
+ int i;
+
+ sectors = 0;
+
+ BUG_ON(index >= bio->bi_vcnt);
+
+ bio_for_each_segment(bv, bio, i) {
+ if (i == index) {
+ if (offset > bv->bv_offset)
+ sectors += (offset - bv->bv_offset) / sector_sz;
+ return sectors;
+ }
+
+ sectors += bv->bv_len / sector_sz;
+ }
+
+ BUG();
+}
+EXPORT_SYMBOL(bio_sector_offset);
/*
* create memory pools for biovec's in a bio_set.
diff -r 550d61001baa -r 318fa71e735d include/linux/bio.h
--- a/include/linux/bio.h Sat Jun 07 00:45:14 2008 -0400
+++ b/include/linux/bio.h Sat Jun 07 00:45:14 2008 -0400
@@ -315,6 +315,8 @@
extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
unsigned int, unsigned int);
extern int bio_get_nr_vecs(struct block_device *);
+extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
+
extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
unsigned long, unsigned int, int);
struct sg_iovec;
--
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