From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794345933; b=A/45OMHOa5C/lcG1/yWwShwjWEqGKQjrHM/gn1FA7v1TOtN35Q5oEaIn4tcRT+HSXUdz QiL06J8N5ADD468Ozbfs2Qky4PvhIlaPeu0IjoDSF/NXNjAbJ4IZ5tqjZ3tQ4LatBaRJD 9b52hQ4L3maG+J2ntyigLRAzZbVDK7D+Q/MKBXpOATpSBwMXQjk3vIL8bThbf1rMlptIf tCTIbgcYvcT57mucr6yKsumIuKCMxkJTlz8f1WWfVeGqbvHKfKq1PKUlpAxnD/nK2qonN /SH4CPsXH+Q24d3KP5wdR6PDDpqjW2yPWNDimC0MTJ+0M9dsrR/Da4EWX9tEaaDDvaw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794345933; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=s4mPlhc58dz/KEgQEibMDKI2tMxaZT0mY/4r1a+31ts=; b=d1XsSueeePmjiZx0UVRNufNnkZKA56GKrg6AagISeImgwfnfl8HJj0SR+KxcF+JfyPLO 0fedBPiZOvw9dmFUmNqXrmnrFba15ktcpOVBCGfO3/2/fPZC6g8RzgI19A8OkfgDLKLo5 u/mqlKbyurXg0SUibtw8rsFd4N6vNhQR6kGeL8xC+GZpQN5dTK1WcmfZnQI32uTTc9rCr Iongn/t2XMAbHXaljRh+nll/Il8eWLN0Lxk5KAcJgkI85TNr6qdGqXFkkAJFCyphz6R39 423/PC7FyehcetvRvciYyPlqH6R05eI6cF4hwSezdMwkMLuGEDfcKS1pbUIvlJtYXDQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fKOWAYgJ; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DE398606A330 for ; Tue, 10 Nov 2026 21:25:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fKOWAYgJ Received: by smtp.kernel.org (Postfix) with ESMTPSA id DAA5F1F008A1; Tue, 10 Nov 2026 21:25:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794345932; bh=s4mPlhc58dz/KEgQEibMDKI2tMxaZT0mY/4r1a+31ts=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fKOWAYgJcWu0yVQv5Y/RlwEMP/2APg+FmtSsS+EgBTUodEV+MdJZEeAlQz2U0eknZ fF5Dt+DPZkn0fzZDMQC7NYS81VFdnUPdmbqrFdxMwJkeGnY4YXNkwibacqKgJOCu7A UtkmBInadT/439jitEyad2suzz1Flyy5rAreaZVk8pAxxVJ7tgOurtALkiZvEC5dlc /8fsgDxe9R7Uvlx/dg9vaYxL4BpgBJm65uVpog70MgRMeFkCQJdzdz3gWCFKyhvaGj eAwt2dmUVZJ6vrf9yukHSQwHF5efNePW0u+LM18QUUTApuz7j+rKnlnsK39ueMYi7x Lu0Ryp7yTFYcA== From: Sasha Levin To: stable@vger.kernel.org Cc: Tal Zussman , Christoph Hellwig , Jan Kara , Christoph Hellwig , Jens Axboe , Sasha Levin Subject: [PATCH 6.12.y 1/2] block: introduce bio_in_atomic() Date: Tue, 10 Nov 2026 16:25:29 -0500 Message-ID: <20261110212248.3885710-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261107052219-failed-6.12-a605d5d71a6d@kernel.org> References: <20261107052219-failed-6.12-a605d5d71a6d@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Tal Zussman [ Upstream commit 8ed0831b5263e1aa48d99063795a1f20e4e69b50 ] Move the atomic context detection logic from erofs's z_erofs_in_atomic() into the block layer as bio_in_atomic(). This helper returns true when the current context is unsafe for sleeping bio completion handlers (e.g., hard/soft IRQ, preempt-disabled). The logic was originally added to erofs in commit c99fab6e80b7 ("erofs: fix atomic context detection when !CONFIG_DEBUG_LOCK_ALLOC"). A subsequent patch will use it in the block layer's bio completion infrastructure, so move it to include/linux/bio.h where both subsystems can share it. Convert erofs to call the new bio_in_atomic() directly. Suggested-by: Christoph Hellwig Signed-off-by: Tal Zussman Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Link: https://patch.msgid.link/20260730-blk-dontcache-v7-1-3e8e6850068d@columbia.edu Signed-off-by: Jens Axboe Stable-dep-of: a605d5d71a6d ("f2fs: fix to use bio_in_atomic() in f2fs_read_end_io()") Signed-off-by: Sasha Levin --- fs/erofs/zdata.c | 11 +---------- include/linux/bio.h | 15 +++++++++++++++ 2 files changed, 16 insertions(+), 10 deletions(-) diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index 08720efbb1a17..10b9aa2c28541 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -1386,15 +1386,6 @@ static void z_erofs_decompressqueue_kthread_work(struct kthread_work *work) } #endif -/* Use (kthread_)work in atomic contexts to minimize scheduling overhead */ -static inline bool z_erofs_in_atomic(void) -{ - if (IS_ENABLED(CONFIG_PREEMPTION) && rcu_preempt_depth()) - return true; - if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) - return true; - return !preemptible(); -} static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io, int bios) @@ -1411,7 +1402,7 @@ static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io, if (atomic_add_return(bios, &io->pending_bios)) return; - if (z_erofs_in_atomic()) { + if (bio_in_atomic()) { /* See `sync_decompress` in sysfs-fs-erofs for more details */ if (sbi->sync_decompress == EROFS_SYNC_DECOMPRESS_AUTO) sbi->sync_decompress = EROFS_SYNC_DECOMPRESS_FORCE_ON; diff --git a/include/linux/bio.h b/include/linux/bio.h index d4f58a2d15b69..104a68749ab1e 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -377,6 +377,21 @@ static inline struct bio *bio_alloc(struct block_device *bdev, void submit_bio(struct bio *bio); +/** + * bio_in_atomic - check if the current context is unsafe for bio completion + * + * Return: %true in atomic contexts (e.g. hard/soft IRQ, preempt-disabled); + * %false when a bio can be safely completed in the current context. + */ +static inline bool bio_in_atomic(void) +{ + if (IS_ENABLED(CONFIG_PREEMPTION) && rcu_preempt_depth()) + return true; + if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) + return true; + return !preemptible(); +} + extern void bio_endio(struct bio *); static inline void bio_io_error(struct bio *bio) -- 2.53.0