From 9753c642a53bc4fbdef06d372d389dce7d8cddc2 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sun, 15 Sep 2024 08:53:45 -0600 Subject: [PATCH] io_uring/rsrc: change ubuf->ubuf_end to length tracking If we change it to tracking ubuf->start + ubuf->len, then we can reduce the size of struct io_mapped_ubuf by another 4 bytes, effectively 8 bytes, as a hole is eliminated too. This shrinks io_mapped_ubuf to 32 bytes. Signed-off-by: Jens Axboe --- io_uring/fdinfo.c | 3 +-- io_uring/rsrc.c | 6 +++--- io_uring/rsrc.h | 4 ++-- 3 files changed, 6 insertions(+), 7 deletions(-) diff --git a/io_uring/fdinfo.c b/io_uring/fdinfo.c index d43e1b5fcb36..6b1247664b35 100644 --- a/io_uring/fdinfo.c +++ b/io_uring/fdinfo.c @@ -177,9 +177,8 @@ __cold void io_uring_show_fdinfo(struct seq_file *m, struct file *file) seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs); for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) { struct io_mapped_ubuf *buf = ctx->user_bufs[i]; - unsigned int len = buf->ubuf_end - buf->ubuf; - seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, len); + seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, buf->len); } if (has_lock && !xa_empty(&ctx->personalities)) { unsigned long index; diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c index 2477995e2d65..131bcdda577a 100644 --- a/io_uring/rsrc.c +++ b/io_uring/rsrc.c @@ -38,7 +38,7 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov, static const struct io_mapped_ubuf dummy_ubuf = { /* set invalid range, so io_import_fixed() fails meeting it */ .ubuf = -1UL, - .ubuf_end = 0, + .len = UINT_MAX, }; int __io_account_mem(struct user_struct *user, unsigned long nr_pages) @@ -985,7 +985,7 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov, size = iov->iov_len; /* store original address for later verification */ imu->ubuf = (unsigned long) iov->iov_base; - imu->ubuf_end = imu->ubuf + iov->iov_len; + imu->len = iov->iov_len; imu->nr_bvecs = nr_pages; imu->folio_shift = PAGE_SHIFT; if (coalesced) @@ -1086,7 +1086,7 @@ int io_import_fixed(int ddir, struct iov_iter *iter, if (unlikely(check_add_overflow(buf_addr, (u64)len, &buf_end))) return -EFAULT; /* not inside the mapped region */ - if (unlikely(buf_addr < imu->ubuf || buf_end > imu->ubuf_end)) + if (unlikely(buf_addr < imu->ubuf || buf_end > (imu->ubuf + imu->len))) return -EFAULT; /* diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h index e290d2be3285..8ed588036210 100644 --- a/io_uring/rsrc.h +++ b/io_uring/rsrc.h @@ -42,11 +42,11 @@ struct io_rsrc_node { struct io_mapped_ubuf { u64 ubuf; - u64 ubuf_end; + unsigned int len; unsigned int nr_bvecs; unsigned int folio_shift; - unsigned long acct_pages; refcount_t refs; + unsigned long acct_pages; struct bio_vec bvec[] __counted_by(nr_bvecs); };