From nobody Tue Dec 16 14:55:38 2025 Received: from out30-119.freemail.mail.aliyun.com (out30-119.freemail.mail.aliyun.com [115.124.30.119]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 66187153569; Thu, 30 May 2024 09:22:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.119 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717060940; cv=none; b=YAAf9+iCZIdsA1Pn2wcwUy9DN/WXDryNjFzTWRXFSCgtU6z0RRlD7Ao88svcM3kgXhGfj2t2B0lpNacV1zjdfC9/Wac1530seTgvdzD8vOsuOcwYLBGsSXaZNExZwsYwgJ3DKtgOVR9A5CAr+Wcl+Ox3qpVEUwhIaF5HSvy+QiY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717060940; c=relaxed/simple; bh=+zmJTiEoepzzsi7E0uJSLhN2mlDIWTQJnSX1CLeHCew=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=IVSrXSvfMvUfjknNC8tUurtnXu54Sztr6NEa4E8EChA9K67U99n5xbusl0XfB3w/KL4ftHxEE53J+m5cJacRZoB/ooyc/cq+XOS84zVLm1gvkTmGJ4VD9D6KLWpEDGoIvP7rhL6aiLGcpdSp6Fkq86g/cPpyB0xForVt7X1H4JI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=T4QUN0Kd; arc=none smtp.client-ip=115.124.30.119 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="T4QUN0Kd" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1717060930; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=LAV4iRoaUKQi+wmPNV5IZ7VOkrMEu/ZXWD6411daKG0=; b=T4QUN0Kd4pGWqUMnLyQ1uSaUUCBbFeJaBGCsmaaaXXjcQTKDZmD7l5g3BhzM0frlz52aqDzuL88G3kY5MOy9eqn9pV76Tn16LhOfLnVZ/DrchZOLjaRJXhJ7WfLdHas6ieTVp0XWIAZpfNembHQn9qe8d1S+szoI0wpqe+agtFc= X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033068173054;MF=hsiangkao@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0W7WbjN._1717060927; Received: from x31i01179.sqa.na131.tbsite.net(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0W7WbjN._1717060927) by smtp.aliyun-inc.com; Thu, 30 May 2024 17:22:09 +0800 From: Gao Xiang To: stable@vger.kernel.org, Greg Kroah-Hartman Cc: linux-erofs@lists.ozlabs.org, Baokun Li , LKML , Gao Xiang , Sandeep Dhavale Subject: [PATCH 6.8.y] erofs: avoid allocating DEFLATE streams before mounting Date: Thu, 30 May 2024 17:22:00 +0800 Message-Id: <20240530092201.16873-2-hsiangkao@linux.alibaba.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240530092201.16873-1-hsiangkao@linux.alibaba.com> References: <20240530092201.16873-1-hsiangkao@linux.alibaba.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" commit 80eb4f62056d6ae709bdd0636ab96ce660f494b2 upstream. Currently, each DEFLATE stream takes one 32 KiB permanent internal window buffer even if there is no running instance which uses DEFLATE algorithm. It's unexpected and wasteful on embedded devices with limited resources and servers with hundreds of CPU cores if DEFLATE is enabled but unused. Fixes: ffa09b3bd024 ("erofs: DEFLATE compression support") Cc: # 6.6+ Reviewed-by: Sandeep Dhavale Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20240520090106.2898681-1-hsiangkao@linux.al= ibaba.com --- fs/erofs/decompressor_deflate.c | 55 +++++++++++++++++---------------- 1 file changed, 29 insertions(+), 26 deletions(-) diff --git a/fs/erofs/decompressor_deflate.c b/fs/erofs/decompressor_deflat= e.c index b98872058abe..26350c5b040e 100644 --- a/fs/erofs/decompressor_deflate.c +++ b/fs/erofs/decompressor_deflate.c @@ -46,39 +46,15 @@ int __init z_erofs_deflate_init(void) /* by default, use # of possible CPUs instead */ if (!z_erofs_deflate_nstrms) z_erofs_deflate_nstrms =3D num_possible_cpus(); - - for (; z_erofs_deflate_avail_strms < z_erofs_deflate_nstrms; - ++z_erofs_deflate_avail_strms) { - struct z_erofs_deflate *strm; - - strm =3D kzalloc(sizeof(*strm), GFP_KERNEL); - if (!strm) - goto out_failed; - - /* XXX: in-kernel zlib cannot shrink windowbits currently */ - strm->z.workspace =3D vmalloc(zlib_inflate_workspacesize()); - if (!strm->z.workspace) { - kfree(strm); - goto out_failed; - } - - spin_lock(&z_erofs_deflate_lock); - strm->next =3D z_erofs_deflate_head; - z_erofs_deflate_head =3D strm; - spin_unlock(&z_erofs_deflate_lock); - } return 0; - -out_failed: - erofs_err(NULL, "failed to allocate zlib workspace"); - z_erofs_deflate_exit(); - return -ENOMEM; } =20 int z_erofs_load_deflate_config(struct super_block *sb, struct erofs_super_block *dsb, void *data, int size) { struct z_erofs_deflate_cfgs *dfl =3D data; + static DEFINE_MUTEX(deflate_resize_mutex); + static bool inited; =20 if (!dfl || size < sizeof(struct z_erofs_deflate_cfgs)) { erofs_err(sb, "invalid deflate cfgs, size=3D%u", size); @@ -89,9 +65,36 @@ int z_erofs_load_deflate_config(struct super_block *sb, erofs_err(sb, "unsupported windowbits %u", dfl->windowbits); return -EOPNOTSUPP; } + mutex_lock(&deflate_resize_mutex); + if (!inited) { + for (; z_erofs_deflate_avail_strms < z_erofs_deflate_nstrms; + ++z_erofs_deflate_avail_strms) { + struct z_erofs_deflate *strm; + + strm =3D kzalloc(sizeof(*strm), GFP_KERNEL); + if (!strm) + goto failed; + /* XXX: in-kernel zlib cannot customize windowbits */ + strm->z.workspace =3D vmalloc(zlib_inflate_workspacesize()); + if (!strm->z.workspace) { + kfree(strm); + goto failed; + } =20 + spin_lock(&z_erofs_deflate_lock); + strm->next =3D z_erofs_deflate_head; + z_erofs_deflate_head =3D strm; + spin_unlock(&z_erofs_deflate_lock); + } + inited =3D true; + } + mutex_unlock(&deflate_resize_mutex); erofs_info(sb, "EXPERIMENTAL DEFLATE feature in use. Use at your own risk= !"); return 0; +failed: + mutex_unlock(&deflate_resize_mutex); + z_erofs_deflate_exit(); + return -ENOMEM; } =20 int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq, --=20 2.39.3