On Fri, Aug 23, 2019 at 09:00:22AM +0800, Ian Kent wrote:
> Add the fs_context_operations method .free that performs fs
> context cleanup on context release.
>
> Signed-off-by: Ian Kent <raven@xxxxxxxxxx>
> ---
> fs/xfs/xfs_super.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index aae0098fecab..9976163dc537 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -2129,10 +2129,32 @@ static const struct super_operations xfs_super_operations = {
> .free_cached_objects = xfs_fs_free_cached_objects,
> };
>
> +static void xfs_fc_free(struct fs_context *fc)
> +{
> + struct xfs_fs_context *ctx = fc->fs_private;
> + struct xfs_mount *mp = fc->s_fs_info;
> +
> + if (mp) {
> + /*
> + * If an error occurs before ownership the xfs_mount
> + * info struct is passed to xfs by the VFS (by assigning
> + * it to sb->s_fs_info and clearing the corresponding
> + * fs_context field, which is done before calling fill
> + * super via .get_tree()) there may be some strings to
> + * cleanup.
> + */
The code looks straightforward but I find the comment confusing. How can
the VFS pass ownership of the xfs_mount if it's an XFS private data
structure?
> + kfree(mp->m_logname);
> + kfree(mp->m_rtname);
> + kfree(mp);
> + }
> + kfree(ctx);
Also, should we at least reassign associated fc pointers to NULL if we
have multiple places to free things like ctx or mp?
Brian
> +}
> +
> static const struct fs_context_operations xfs_context_ops = {
> .parse_param = xfs_parse_param,
> .get_tree = xfs_get_tree,
> .reconfigure = xfs_reconfigure,
> + .free = xfs_fc_free,
> };
>
> static struct file_system_type xfs_fs_type = {
>
