From: Keith Busch Date: Mon, 10 Mar 2025 18:48:25 +0000 (-0700) Subject: Revert "io_uring/rsrc: simplify the bvec iter count calculation" X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=334f795ff8fc061db448d205a252880a19d7c045;p=users%2Fwilly%2Flinux.git Revert "io_uring/rsrc: simplify the bvec iter count calculation" This reverts commit 2a51c327d4a4a2eb62d67f4ea13a17efd0f25c5c. The kernel registered bvecs do use the iov_iter_advance() API, so we can't rely on this simplification anymore. Fixes: 27cb27b6d5ea40 ("io_uring: add support for kernel registered bvecs") Reported-by: Caleb Sander Mateos Signed-off-by: Keith Busch Reviewed-by: Caleb Sander Mateos Link: https://lore.kernel.org/r/20250310184825.569371-1-kbusch@meta.com Signed-off-by: Jens Axboe --- diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c index 5dd1e0827559..5fff6ba2b7c0 100644 --- a/io_uring/rsrc.c +++ b/io_uring/rsrc.c @@ -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); } }