block: Remove bi_idx hacks

Now that drivers have been converted to the new bvec_iter primitives,
there's no need to trim the bvec before we submit it; and we can't trim
it once we start sharing bvecs.

It used to be that passing a partially completed bio (i.e. one with
nonzero bi_idx) to generic_make_request() was a dangerous thing -
various drivers would choke on such things. But with immutable biovecs
and our new bio splitting that shares the biovecs, submitting partially
completed bios has to work (and should work, now that all the drivers
have been completed to the new primitives)

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>

1 files changed, 0 insertions, 23 deletions

diff --git a/fs/bio.c b/fs/bio.c
index 9cff939b1bc6..e6dfa06773ac 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -1822,11 +1822,7 @@ void bio_trim(struct bio *bio, int offset, int size)
 {
         /* 'bio' is a cloned bio which we need to trim to match
          * the given offset and size.
-         * This requires adjusting bi_sector, bi_size, and bi_io_vec
          */
-        int i;
-        struct bio_vec *bvec;
-        int sofar = 0;
 
         size <<= 9;
         if (offset == 0 && size == bio->bi_iter.bi_size)
@@ -1837,25 +1833,6 @@ void bio_trim(struct bio *bio, int offset, int size)
         bio_advance(bio, offset << 9);
 
         bio->bi_iter.bi_size = size;
-
-        /* avoid any complications with bi_idx being non-zero*/
-        if (bio->bi_iter.bi_idx) {
-                memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_iter.bi_idx,
-                        (bio->bi_vcnt - bio->bi_iter.bi_idx) *
-                        sizeof(struct bio_vec));
-                bio->bi_vcnt -= bio->bi_iter.bi_idx;
-                bio->bi_iter.bi_idx = 0;
-        }
-        /* Make sure vcnt and last bv are not too big */
-        bio_for_each_segment_all(bvec, bio, i) {
-                if (sofar + bvec->bv_len > size)
-                        bvec->bv_len = size - sofar;
-                if (bvec->bv_len == 0) {
-                        bio->bi_vcnt = i;
-                        break;
-                }
-                sofar += bvec->bv_len;
-        }
 }
 EXPORT_SYMBOL_GPL(bio_trim);