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 <axboe@xxxxxxxxx>
---
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);
};
--
2.45.2
