Revert "io_uring/rsrc: simplify the bvec iter count calculation"

This reverts commit 2a51c327d4.

The kernel registered bvecs do use the iov_iter_advance() API, so we
can't rely on this simplification anymore.

Fixes: 27cb27b6d5 ("io_uring: add support for kernel registered bvecs")
Reported-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Link: https://lore.kernel.org/r/20250310184825.569371-1-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Keith Busch 2025-03-10 11:48:25 -07:00 committed by Jens Axboe
parent 390174c91d
commit 334f795ff8

View File

@ -1024,7 +1024,7 @@ static int io_import_fixed(int ddir, struct iov_iter *iter,
* and advance us to the beginning.
*/
offset = buf_addr - imu->ubuf;
iov_iter_bvec(iter, ddir, imu->bvec, imu->nr_bvecs, len);
iov_iter_bvec(iter, ddir, imu->bvec, imu->nr_bvecs, offset + len);
if (offset) {
/*
@ -1051,6 +1051,7 @@ static int io_import_fixed(int ddir, struct iov_iter *iter,
* to use the slow iter advance.
*/
if (offset < bvec->bv_len) {
iter->count -= offset;
iter->iov_offset = offset;
} else if (imu->is_kbuf) {
iov_iter_advance(iter, offset);
@ -1063,6 +1064,7 @@ static int io_import_fixed(int ddir, struct iov_iter *iter,
iter->bvec += seg_skip;
iter->nr_segs -= seg_skip;
iter->count -= bvec->bv_len + offset;
iter->iov_offset = offset & ((1UL << imu->folio_shift) - 1);
}
}