From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9A517211A05; Wed, 25 Mar 2026 09:06:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774429585; cv=none; b=S/BiS1TXupxlalNNs1axY1yMUh/PFxpB4BgcQ0sYQt8NhqMzonhia/qkONPEzX6A1gUBWZr1FkQ1brPOy3mztHpp5ztckfMWMX7Vrkbce5KuUR8sE6rGGVn6hvtyPSkkboRV10JwwlEe0uEuRlYCYPJsBshWeX9I2YgjauF+oSE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774429585; c=relaxed/simple; bh=TGeHJllmZaOU480qUtXeb/jUm42/azepnhJdaLl9P5A=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=F9h5GRnOS7N2DXbJ51rWO67AuAs8sqG8R4t4HJtTAFq7Cm+yrcwI2Jb80u4tHsUt43GrrrhlqY2LZvLkCpbAvd8P+2+y35TQhhRfimLv4Gk0hLp1WPbb9n97SFr0/TEOuNcWUevxpVX/rXoY49NbCXV3JKd1yZTtWUMLUE2WcLc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=B/pXGWqx; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="B/pXGWqx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F5A1C4CEF7; Wed, 25 Mar 2026 09:06:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774429585; bh=TGeHJllmZaOU480qUtXeb/jUm42/azepnhJdaLl9P5A=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=B/pXGWqxkc77H/QNjcNN4hXFs+1yWtOO/K6ZlFDqfhgwHp4yHtUXBY1gINF1N/v7H Swoeh/4pl25iEnor6XcK93/xaSpBQCXea/x0tJWaU2vmaO0gQrTCNvrvDCRgFprVKV 1KqlwKP+22aqYID5Rc4LF4kA7w+kAFXYTzDiwCQpdMmDJrHF9HDz+HIU9m1OkF3LTb /jwCEhab+UIAPA9vKX7zWI8lclKZJMoZ3e82DcRkAVWva3ZfDqkkW0tKKWs9g8wCY/ xPGCmHA6G5g4E8Zs8WC6hluY2t54Kvjz8OpvZWbU1RkOlOvI5O2Nk6MOymHovUB97F cRXNnffbCU5+g== Message-ID: Date: Wed, 25 Mar 2026 10:06:15 +0100 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 09/21] fs: afs: revert mmap_prepare() change Content-Language: en-US To: "Lorenzo Stoakes (Oracle)" , Andrew Morton Cc: Jonathan Corbet , Clemens Ladisch , Arnd Bergmann , Greg Kroah-Hartman , "K . Y . Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Long Li , Alexander Shishkin , Maxime Coquelin , Alexandre Torgue , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Bodo Stroesser , "Martin K . Petersen" , David Howells , Marc Dionne , Alexander Viro , Christian Brauner , Jan Kara , David Hildenbrand , "Liam R . Howlett" , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Pedro Falcato , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-mtd@lists.infradead.org, linux-staging@lists.linux.dev, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-afs@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Ryan Roberts References: <08804c94e39d9102a3a8fbd12385e8aa079ba1d3.1774045440.git.ljs@kernel.org> From: "Vlastimil Babka (SUSE)" In-Reply-To: <08804c94e39d9102a3a8fbd12385e8aa079ba1d3.1774045440.git.ljs@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/20/26 23:39, Lorenzo Stoakes (Oracle) wrote: > Partially reverts commit 9d5403b1036c ("fs: convert most other > generic_file_*mmap() users to .mmap_prepare()"). > > This is because the .mmap invocation establishes a refcount, but > .mmap_prepare is called at a point where a merge or an allocation failure > might happen after the call, which would leak the refcount increment. > > Functionality is being added to permit the use of .mmap_prepare in this > case, but in the interim, we need to fix this. > > Fixes: 9d5403b1036c ("fs: convert most other generic_file_*mmap() users to .mmap_prepare()") > Cc: > Signed-off-by: Lorenzo Stoakes (Oracle) Acked-by: Vlastimil Babka (SUSE) > --- > fs/afs/file.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/fs/afs/file.c b/fs/afs/file.c > index f609366fd2ac..74d04af51ff4 100644 > --- a/fs/afs/file.c > +++ b/fs/afs/file.c > @@ -19,7 +19,7 @@ > #include > #include "internal.h" > > -static int afs_file_mmap_prepare(struct vm_area_desc *desc); > +static int afs_file_mmap(struct file *file, struct vm_area_struct *vma); > > static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter); > static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos, > @@ -35,7 +35,7 @@ const struct file_operations afs_file_operations = { > .llseek = generic_file_llseek, > .read_iter = afs_file_read_iter, > .write_iter = netfs_file_write_iter, > - .mmap_prepare = afs_file_mmap_prepare, > + .mmap = afs_file_mmap, > .splice_read = afs_file_splice_read, > .splice_write = iter_file_splice_write, > .fsync = afs_fsync, > @@ -492,16 +492,16 @@ static void afs_drop_open_mmap(struct afs_vnode *vnode) > /* > * Handle setting up a memory mapping on an AFS file. > */ > -static int afs_file_mmap_prepare(struct vm_area_desc *desc) > +static int afs_file_mmap(struct file *file, struct vm_area_struct *vma) > { > - struct afs_vnode *vnode = AFS_FS_I(file_inode(desc->file)); > + struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); > int ret; > > afs_add_open_mmap(vnode); > > - ret = generic_file_mmap_prepare(desc); > + ret = generic_file_mmap(file, vma); > if (ret == 0) > - desc->vm_ops = &afs_vm_ops; > + vma->vm_ops = &afs_vm_ops; > else > afs_drop_open_mmap(vnode); > return ret;