This is a note to let you know that I've just added the patch titled
io_uring/kbuf: get rid of bl->is_ready
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
io_uring-kbuf-get-rid-of-bl-is_ready.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3b80cff5a4d117c53d38ce805823084eaeffbde6 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@xxxxxxxxx>
Date: Thu, 14 Mar 2024 10:46:40 -0600
Subject: io_uring/kbuf: get rid of bl->is_ready
From: Jens Axboe <axboe@xxxxxxxxx>
commit 3b80cff5a4d117c53d38ce805823084eaeffbde6 upstream.
Now that xarray is being exclusively used for the buffer_list lookup,
this check is no longer needed. Get rid of it and the is_ready member.
Cc: stable@xxxxxxxxxxxxxxx # v6.4+
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
io_uring/kbuf.c | 8 --------
io_uring/kbuf.h | 2 --
2 files changed, 10 deletions(-)
--- a/io_uring/kbuf.c
+++ b/io_uring/kbuf.c
@@ -59,7 +59,6 @@ static int io_buffer_add_list(struct io_
* always under the ->uring_lock, but the RCU lookup from mmap does.
*/
bl->bgid = bgid;
- smp_store_release(&bl->is_ready, 1);
return xa_err(xa_store(&ctx->io_bl_xa, bgid, bl, GFP_KERNEL));
}
@@ -691,13 +690,6 @@ void *io_pbuf_get_address(struct io_ring
if (!bl || !bl->is_mmap)
return NULL;
- /*
- * Ensure the list is fully setup. Only strictly needed for RCU lookup
- * via mmap, and in that case only for the array indexed groups. For
- * the xarray lookups, it's either visible and ready, or not at all.
- */
- if (!smp_load_acquire(&bl->is_ready))
- return NULL;
return bl->buf_ring;
}
--- a/io_uring/kbuf.h
+++ b/io_uring/kbuf.h
@@ -29,8 +29,6 @@ struct io_buffer_list {
__u8 is_mapped;
/* ring mapped provided buffers, but mmap'ed by application */
__u8 is_mmap;
- /* bl is visible from an RCU point of view for lookup */
- __u8 is_ready;
};
struct io_buffer {
Patches currently in stable-queue which might be from axboe@xxxxxxxxx are
queue-6.6/io_uring-use-private-workqueue-for-exit-work.patch
queue-6.6/io_uring-kbuf-protect-io_buffer_list-teardown-with-a-reference.patch
queue-6.6/io_uring-kbuf-hold-io_buffer_list-reference-over-mmap.patch
queue-6.6/io_uring-kbuf-get-rid-of-lower-bgid-lists.patch
queue-6.6/io_uring-kbuf-get-rid-of-bl-is_ready.patch
