From: Jens Axboe <[email protected]>
To: [email protected]
Cc: Jens Axboe <[email protected]>
Subject: [PATCH 2/3] io_uring/rsrc: add reference count to struct io_mapped_ubuf
Date: Wed, 11 Sep 2024 14:03:53 -0600 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
Currently there's a single ring owner of a mapped buffer, and hence the
reference count will always be 1 when it's torn down and freed. However,
in preparation for being able to link io_mapped_ubuf to different spots,
add a reference count to manage the lifetime of it.
Signed-off-by: Jens Axboe <[email protected]>
---
io_uring/rsrc.c | 3 +++
io_uring/rsrc.h | 1 +
2 files changed, 4 insertions(+)
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index d42114845fac..28f98de3c304 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -116,6 +116,8 @@ static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf **slo
*slot = NULL;
if (imu != &dummy_ubuf) {
+ if (!refcount_dec_and_test(&imu->refs))
+ return;
for (i = 0; i < imu->nr_bvecs; i++)
unpin_user_page(imu->bvec[i].bv_page);
if (imu->acct_pages)
@@ -990,6 +992,7 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
imu->folio_shift = data.folio_shift;
imu->folio_mask = ~((1UL << data.folio_shift) - 1);
}
+ refcount_set(&imu->refs, 1);
off = (unsigned long) iov->iov_base & ~imu->folio_mask;
*pimu = imu;
ret = 0;
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 3d0dda3556e6..98a253172c27 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -47,6 +47,7 @@ struct io_mapped_ubuf {
unsigned int folio_shift;
unsigned long acct_pages;
unsigned long folio_mask;
+ refcount_t refs;
struct bio_vec bvec[] __counted_by(nr_bvecs);
};
--
2.45.2
next prev parent reply other threads:[~2024-09-11 20:07 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-11 20:03 [PATCHSET 0/3] Provide more efficient buffer registration Jens Axboe
2024-09-11 20:03 ` [PATCH 1/3] io_uring/rsrc: clear 'slot' entry upfront Jens Axboe
2024-09-11 20:03 ` Jens Axboe [this message]
2024-09-11 20:03 ` [PATCH 3/3] io_uring: add IORING_REGISTER_COPY_BUFFERS method Jens Axboe
2024-09-11 20:13 ` [PATCHSET 0/3] Provide more efficient buffer registration Jens Axboe
-- strict thread matches above, loose matches on Subject: below --
2024-09-11 20:29 [PATCHSET v2 " Jens Axboe
2024-09-11 20:29 ` [PATCH 2/3] io_uring/rsrc: add reference count to struct io_mapped_ubuf Jens Axboe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
[email protected] \
[email protected] \
[email protected] \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox