From: Andreas Dilger <adilger@dilger.ca>
To: Antoine Tenart <antoine.tenart@bootlin.com>
Cc: Ext4 Developers List <linux-ext4@vger.kernel.org>,
tytso@mit.edu, matthew.weber@rockwellcollins.com,
thomas.petazzoni@bootlin.com
Subject: Re: [PATCH] create_inode: set xattrs to the root directory as well
Date: Fri, 17 Jul 2020 01:46:37 -0600 [thread overview]
Message-ID: <7234E28B-C60F-4AB0-BCD9-4018B1A10B8D@dilger.ca> (raw)
In-Reply-To: <20200701153404.1647002-1-antoine.tenart@bootlin.com>
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On Jul 1, 2020, at 9:34 AM, Antoine Tenart <antoine.tenart@bootlin.com> wrote:
>
> __populate_fs do copy the xattrs for all files and directories, but the
> root directory is skipped and as a result its extended attributes aren't
> set. This is an issue when using mkfs to build a full system image that
> can be used with SElinux in enforcing mode without making any runtime
> fix at first boot.
>
> This patch adds logic to set the root directory's extended attributes.
>
> Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
> ---
> misc/create_inode.c | 24 +++++++++++++++++++++++-
> 1 file changed, 23 insertions(+), 1 deletion(-)
>
> diff --git a/misc/create_inode.c b/misc/create_inode.c
> index e8d1df6b55a5..0a6e4dc23d16 100644
> --- a/misc/create_inode.c
> +++ b/misc/create_inode.c
> @@ -820,7 +820,29 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
>
> for (i = 0; i < num_dents; free(dent[i]), i++) {
> name = dent[i]->d_name;
> - if ((!strcmp(name, ".")) || (!strcmp(name, "..")))
> + if (!strcmp(name, ".")) {
(style) despite what was previously in the code, I think it is clearer
to write "if (strcmp(name, ".") == 0)", because it doesn't read like
"if not string compare" since that incorrectly seems like the strings
are *not* matching.
> + retval = ext2fs_namei(fs, root, parent_ino, ".", &ino);
> + if (retval) {
> + com_err(name, retval, 0);
> + goto out;
> + }
> +
> + /*
> + * Take special care for the root directory, to copy its
> + * extended attributes.
> + */
> + if (ino == root) {
Rather than checking this for every directory, it would be more efficient
to copy the root xattrs only at the start of the copy in populate_fs2(),
before the tree walk has started. Something like:
file_info.path_len = 0;
file_info.path_max_len = 255;
file_info.path = calloc(file_info.path_max_len, 1);
+ retval = set_inode_xattr(fs, parent_ino, source_dir);
+ if (retval) {
+ com_err(__func__, retval,
+ _("while copying xattrs on root directory"));
+ goto out;
+ }
+
retval = __populate_fs(fs, parent_ino, source_dir, root, &hdlinks,
&file_info, fs_callbacks);
That is an even less code added, which is always good.
Cheers, Andreas
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next prev parent reply other threads:[~2020-07-17 7:46 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-01 15:34 [PATCH] create_inode: set xattrs to the root directory as well Antoine Tenart
2020-07-17 7:29 ` Antoine Tenart
2020-07-17 7:46 ` Andreas Dilger [this message]
2020-07-17 8:24 ` Antoine Tenart
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