From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.burntcomma.com (mail2.burntcomma.com [217.169.27.34]) (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 2E1CD257423 for ; Thu, 16 Apr 2026 17:44:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.169.27.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776361453; cv=none; b=n8DU+AG2IoE5t0Jx7ms9s35YuYse12aloKwZA+kaIR6JdL/+WMZ72Oq/CrJeYfDZdSiCMZ+k498uJIDIEhkuoUh3XxIx+iKcrdpPj19YwT94nFlsY5LjoEokX/nZjkEwE28K0obvvB1YibZmRirrcXmWifmW3XcWNUuCDVmuj1M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776361453; c=relaxed/simple; bh=UQpG4pknwQhQ8/jo0nMaduj9Yro6Cm8OBKcwC2bkgIg=; h=From:To:Cc:Subject:Date:Message-ID:Mime-Version; b=R2s0JxleVd3OsatqfYcNGo18lPCxrgcQ5tkWru+xrebDX23wL5lxmYtZ6aQylW2k9Cjp+LzwtTRNMPAPFczdG4CtuqePyrKTNtz7o9C/GGV4GrIoGSAuehaR/SI/+EJspXi/uSXrra0CtXMfWsaVhbQfQlfvrGTs8yA3kDTxTO4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=harmstone.com; spf=pass smtp.mailfrom=harmstone.com; dkim=pass (1024-bit key) header.d=harmstone.com header.i=@harmstone.com header.b=Pn93DSgj; arc=none smtp.client-ip=217.169.27.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=harmstone.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=harmstone.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=harmstone.com header.i=@harmstone.com header.b="Pn93DSgj" Received: from beren (beren.burntcomma.com [IPv6:2a02:8012:8cf0:0:ce28:aaff:fe0d:6db2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by mail.burntcomma.com (Postfix) with ESMTPSA id B574531E3D3; Thu, 16 Apr 2026 18:44:00 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=harmstone.com; s=mail; t=1776361440; bh=xOW12QrhSrdisluGnGznJDyD4lUTjXxHQgiOVrLvCkM=; h=From:To:Cc:Subject:Date; b=Pn93DSgjyrksgpeNhX/+0qEsDVfL0vEgZIf8C/UYO5vCzBYkKjx4TumArHzTgQPhm yie+zzJG1UI7HzaiPxfL5xRE9CyVkK4ZszB0yXc5XHRk5a5GgpJfIXk0UznmFOnbkX s15SkR69oEY3JbUplORnTnI/qdmHcTyDo7sTNT30= From: Mark Harmstone To: linux-btrfs@vger.kernel.org Cc: Mark Harmstone Subject: [PATCH] btrfs: fix double-decrement of bytes_may_use in submit_one_async_extent() Date: Thu, 16 Apr 2026 18:43:51 +0100 Message-ID: <20260416174359.262120-1-mark@harmstone.com> Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: 8bit submit_one_async_extent() calls btrfs_reserve_extent(), which decrements bytes_may_use. If the call btrfs_create_io_em() fails, we jump to out_free_reserve, which calls extent_clear_unlock_delalloc(). Because we're specifying EXTENT_DO_ACCOUNTING, i.e. EXTENT_CLEAR_META_RESV | EXTENT_CLEAR_DATA_RESV, this decreases bytes_may_use again. This can lead to problems later on, as an initial write can fail only for the writeback to silently ENOSPC. Fix this by replacing EXTENT_DO_ACCOUNTING with EXTENT_CLEAR_META_RESV. This parallels a4fe134fc1d8, which is the same fix in cow_one_range(). Fixes: 151a41bc46df ("Btrfs: fix what bits we clear when erroring out from delalloc") Signed-off-by: Mark Harmstone --- fs/btrfs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 36bbf2297a9987..abedaeb45189a2 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1204,7 +1204,7 @@ static void submit_one_async_extent(struct async_chunk *async_chunk, NULL, &cached, EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW | - EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING, + EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV, PAGE_UNLOCK | PAGE_START_WRITEBACK | PAGE_END_WRITEBACK); if (async_extent->cb) -- 2.52.0