From patchwork Thu Mar 28 23:31:35 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13609744 Received: from mail-pg1-f178.google.com (mail-pg1-f178.google.com [209.85.215.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C224E136E2F for ; Thu, 28 Mar 2024 23:35:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.178 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711668905; cv=none; b=IJndIs2hvn4Z98QOz7NKqJ2JGp9ejLTSIK2MhE3vWGXkYQHFGdsORJMbsrNpIk5K/OLccQwzSNBVNFAtcemKv9hC4sVqP3UZI9Fzn0CfUWQOva2+1bTDIwumeCgQSUpQGzoJMJAXlYGMHzXnQaGidPsKyukGYWDLGGp7i08UOG8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711668905; c=relaxed/simple; bh=5YqocHr5mxuGOr5Z0D+Jj5Z+RZ0wDYj67RIhWvHLoys=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PwYwKmynCgat1wzI/PORK9Ql2VKwzQ78WZvilkgPztGwQphO/r0h+hcHx5VsT+UVP8+/fP7g0jalS8nmgkxuJxUGYUrzktZpLbiIHo/9vv4KJUqBMm1amEvelxbQ206z9Oi1hEK7CjGWt2F0E7CZhxI8Wb1bTOCzhpKy/WCZNgk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=teIZ5hNL; arc=none smtp.client-ip=209.85.215.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="teIZ5hNL" Received: by mail-pg1-f178.google.com with SMTP id 41be03b00d2f7-5d862e8b163so317588a12.1 for ; Thu, 28 Mar 2024 16:35:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1711668902; x=1712273702; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=dRbXBnmBssLCefthvGjqIke1i8J8DEDsrgn5OvhdPnw=; b=teIZ5hNLpjWL4f2YYNHiFcN1bHOtAivqdcs11h8WICOgDuAm08cZlHHBv2EQH1xF4A 48/6RwBNjoOqLOq/tjBZntr/sd5aQruAFLQbZMX4bU9qikozIxkKfmmifiDySxjoQ4mb pg03reP5RUTG/aCLsEx9tpvwRfETzgVFNTVXBDFhSfHAdbKbEWfq/gK971wWvOXilAN5 KUTmD4bWoSV+V+mfA/q1lShTEFLKfffzvzexqqqarQJKVEema9SzVfvbg8sp68hoKJ3h 3hS/yA4rGMm8LVMXFaapxcC1jlTuNogWSOsyIerH9qF3qbgB45b9TDm7B9A8ZV6Qery8 2xug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1711668902; x=1712273702; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=dRbXBnmBssLCefthvGjqIke1i8J8DEDsrgn5OvhdPnw=; b=OXu/MZi1MF4SBan18DcVOyxL4kQDrvc1y8j+pK44DyCbs7qHQQh8oBbA+Q832ve+VN 8EDoaua4T8K7aDfc6QRjL7Qk/Ye1aOT2fUaVWYrI+9oi+5peGCy6WMXhL3pcjmRLyxfK XB1mEbGo7AL7TAWenL0SihkOSFRTfPWiJqIpimbPrGrpwr+dyf+1tEjhXbIuZfxhFrAG d47N/3XsQBSAjglqhAHjgDxkiUvhpX/bt9i5JHSGwsOGKu+EVmvDdA8llnjnKyYSGt5N z2DYLvOLWfpKoxFixoi2el9I32jnYt4VJrtgXGCJK+wKsXzHUTFHjgfsKufBbVEdQqAB PRtg== X-Gm-Message-State: AOJu0Yxp+5+zPm2R72TCnvpradGxXIqj+NSpx5iSxdakj5fWY1nBJZhA 1LrOfCr6jZliesUyYeRkk83PR5wZlhya6BKYnW2dYr3CSShOy41fAug4xS6qTfsCG3bwjibSLPu x X-Google-Smtp-Source: AGHT+IGnkir1bN5136ABMvARK0KWrUS1v8cnv/2ciEs2ZgD62XmYdr831W5IH0VHpvUGUB6Jfiipeg== X-Received: by 2002:a17:902:c401:b0:1dd:e128:16b1 with SMTP id k1-20020a170902c40100b001dde12816b1mr933529plk.6.1711668902540; Thu, 28 Mar 2024 16:35:02 -0700 (PDT) Received: from localhost.localdomain ([50.234.116.5]) by smtp.gmail.com with ESMTPSA id i6-20020a170902c94600b001e0b3c9fe60sm2216981pla.46.2024.03.28.16.35.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Mar 2024 16:35:00 -0700 (PDT) From: Jens Axboe To: io-uring@vger.kernel.org Cc: hannes@cmpxchg.org, Jens Axboe Subject: [PATCH 08/11] io_uring/kbuf: protect io_buffer_list teardown with a reference Date: Thu, 28 Mar 2024 17:31:35 -0600 Message-ID: <20240328233443.797828-9-axboe@kernel.dk> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240328233443.797828-1-axboe@kernel.dk> References: <20240328233443.797828-1-axboe@kernel.dk> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 No functional changes in this patch, just in preparation for being able to keep the buffer list alive outside of the ctx->uring_lock. Signed-off-by: Jens Axboe --- io_uring/kbuf.c | 15 +++++++++++---- io_uring/kbuf.h | 2 ++ 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index 72c15dde34d3..206f4d352e15 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -62,6 +62,7 @@ static int io_buffer_add_list(struct io_ring_ctx *ctx, * always under the ->uring_lock, but the RCU lookup from mmap does. */ bl->bgid = bgid; + atomic_set(&bl->refs, 1); return xa_err(xa_store(&ctx->io_bl_xa, bgid, bl, GFP_KERNEL)); } @@ -259,6 +260,14 @@ static int __io_remove_buffers(struct io_ring_ctx *ctx, return i; } +static void io_put_bl(struct io_ring_ctx *ctx, struct io_buffer_list *bl) +{ + if (atomic_dec_and_test(&bl->refs)) { + __io_remove_buffers(ctx, bl, -1U); + kfree_rcu(bl, rcu); + } +} + void io_destroy_buffers(struct io_ring_ctx *ctx) { struct io_buffer_list *bl; @@ -268,8 +277,7 @@ void io_destroy_buffers(struct io_ring_ctx *ctx) xa_for_each(&ctx->io_bl_xa, index, bl) { xa_erase(&ctx->io_bl_xa, bl->bgid); - __io_remove_buffers(ctx, bl, -1U); - kfree_rcu(bl, rcu); + io_put_bl(ctx, bl); } /* @@ -671,9 +679,8 @@ int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg) if (!bl->is_buf_ring) return -EINVAL; - __io_remove_buffers(ctx, bl, -1U); xa_erase(&ctx->io_bl_xa, bl->bgid); - kfree_rcu(bl, rcu); + io_put_bl(ctx, bl); return 0; } diff --git a/io_uring/kbuf.h b/io_uring/kbuf.h index fdbb10449513..8b868a1744e2 100644 --- a/io_uring/kbuf.h +++ b/io_uring/kbuf.h @@ -25,6 +25,8 @@ struct io_buffer_list { __u16 head; __u16 mask; + atomic_t refs; + /* ring mapped provided buffers */ __u8 is_buf_ring; /* ring mapped provided buffers, but mmap'ed by application */