From: Christoph Hellwig <hch@lst.de>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: linux-kernel@vger.kernel.org, virtio-fs@redhat.com,
viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org,
Christoph Hellwig <hch@lst.de>
Subject: Re: [Virtio-fs] [PATCH 3/2] fs: simplify get_filesystem_list / get_all_fs_names
Date: Wed, 30 Jun 2021 07:36:01 +0200 [thread overview]
Message-ID: <20210630053601.GA29241@lst.de> (raw)
In-Reply-To: <20210629205048.GE5231@redhat.com>
On Tue, Jun 29, 2021 at 04:50:48PM -0400, Vivek Goyal wrote:
> May be we should modify mount_block_root() code so that it does not
> require that extra "\0". Possibly zero initialize page and that should
> make sure list_bdev_fs_names() does not have to worry about it.
>
> It is possible that a page gets full from the list of filesystems, and
> last byte on page is terminating null. In that case just zeroing page
> will not help. We can keep track of some sort of end pointer and make
> sure we are not searching beyond that for valid filesystem types.
>
> end = page + PAGE_SIZE - 1;
>
> mount_block_root()
> {
> for (p = fs_names; p < end && *p; p += strlen(p)+1) {
> }
> }
Maybe. To honest I'd prefer to not even touch this unrelated code given
how full of landmines it is :)
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>,
Christoph Hellwig <hch@lst.de>,
viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org,
virtio-fs@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: [Virtio-fs] [PATCH 3/2] fs: simplify get_filesystem_list / get_all_fs_names
Date: Wed, 30 Jun 2021 07:36:01 +0200 [thread overview]
Message-ID: <20210630053601.GA29241@lst.de> (raw)
In-Reply-To: <20210629205048.GE5231@redhat.com>
On Tue, Jun 29, 2021 at 04:50:48PM -0400, Vivek Goyal wrote:
> May be we should modify mount_block_root() code so that it does not
> require that extra "\0". Possibly zero initialize page and that should
> make sure list_bdev_fs_names() does not have to worry about it.
>
> It is possible that a page gets full from the list of filesystems, and
> last byte on page is terminating null. In that case just zeroing page
> will not help. We can keep track of some sort of end pointer and make
> sure we are not searching beyond that for valid filesystem types.
>
> end = page + PAGE_SIZE - 1;
>
> mount_block_root()
> {
> for (p = fs_names; p < end && *p; p += strlen(p)+1) {
> }
> }
Maybe. To honest I'd prefer to not even touch this unrelated code given
how full of landmines it is :)
next prev parent reply other threads:[~2021-06-30 5:36 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-21 6:26 [Virtio-fs] support booting of arbitrary non-blockdevice file systems v2 Christoph Hellwig
2021-06-21 6:26 ` Christoph Hellwig
2021-06-21 6:26 ` [Virtio-fs] [PATCH 1/2] init: split get_fs_names Christoph Hellwig
2021-06-21 6:26 ` Christoph Hellwig
2021-06-21 14:46 ` [Virtio-fs] " Al Viro
2021-06-21 14:46 ` Al Viro
2021-06-21 14:51 ` [Virtio-fs] " Al Viro
2021-06-21 14:51 ` Al Viro
2021-06-21 14:53 ` [Virtio-fs] " Christoph Hellwig
2021-06-21 14:53 ` Christoph Hellwig
2021-06-21 14:59 ` [Virtio-fs] " Al Viro
2021-06-21 14:59 ` Al Viro
2021-06-21 15:09 ` [Virtio-fs] " Matthew Wilcox
2021-06-21 15:09 ` Matthew Wilcox
2021-06-21 15:22 ` [Virtio-fs] " Christoph Hellwig
2021-06-21 15:22 ` Christoph Hellwig
2021-06-21 6:26 ` [Virtio-fs] [PATCH 2/2] init: allow mounting arbitrary non-blockdevice filesystems as root Christoph Hellwig
2021-06-21 6:26 ` Christoph Hellwig
2021-06-21 13:31 ` [Virtio-fs] support booting of arbitrary non-blockdevice file systems v2 Stefan Hajnoczi
2021-06-21 13:31 ` Stefan Hajnoczi
2021-06-21 14:35 ` Vivek Goyal
2021-06-21 14:35 ` Vivek Goyal
2021-06-22 8:12 ` [Virtio-fs] [PATCH 3/2] fs: simplify get_filesystem_list / get_all_fs_names Christoph Hellwig
2021-06-22 8:12 ` Christoph Hellwig
2021-06-22 8:36 ` [Virtio-fs] " Stefan Hajnoczi
2021-06-22 8:36 ` Stefan Hajnoczi
2021-06-29 20:50 ` Vivek Goyal
2021-06-29 20:50 ` Vivek Goyal
2021-06-30 5:36 ` Christoph Hellwig [this message]
2021-06-30 5:36 ` Christoph Hellwig
2021-06-30 17:33 ` Vivek Goyal
2021-06-30 17:33 ` Vivek Goyal
2021-07-07 21:04 ` Vivek Goyal
2021-07-07 21:04 ` Vivek Goyal
2021-07-07 21:06 ` Vivek Goyal
2021-07-07 21:06 ` Vivek Goyal
2021-07-08 12:59 ` Vivek Goyal
2021-07-08 12:59 ` Vivek Goyal
2021-07-12 18:21 ` Vivek Goyal
2021-07-12 18:21 ` Vivek Goyal
2021-07-13 5:40 ` Christoph Hellwig
2021-07-13 5:40 ` Christoph Hellwig
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