libfs: allow to specify s_d_flags

Make it possible for pseudo filesystems to specify default dentry flags.

Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-1-2e6f823ebdc0@kernel.org
Tested-by: syzbot@syzkaller.appspotmail.com
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/libfs.c b/fs/libfs.c
index ce8c496a6940ac4727e845ac57d8e2645d2ab36f..4bb4d8a313e7c6615669b6cdc9d45354c17b716b 100644 (file)
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -680,6 +680,7 @@ static int pseudo_fs_fill_super(struct super_block *s, struct fs_context *fc)
        s->s_export_op = ctx->eops;
        s->s_xattr = ctx->xattr;
        s->s_time_gran = 1;
+       s->s_d_flags |= ctx->s_d_flags;
        root = new_inode(s);
        if (!root)
                return -ENOMEM;

diff --git a/include/linux/pseudo_fs.h b/include/linux/pseudo_fs.h
index 2503f7625d65e7b1fbe9e64d5abf06cd8f017b5f..a651e60d94107e94de18bec6953c3824f0da26c5 100644 (file)
--- a/include/linux/pseudo_fs.h
+++ b/include/linux/pseudo_fs.h
@@ -9,6 +9,7 @@ struct pseudo_fs_context {
        const struct xattr_handler * const *xattr;
        const struct dentry_operations *dops;
        unsigned long magic;
+       unsigned int s_d_flags;
 };
 
 struct pseudo_fs_context *init_pseudo(struct fs_context *fc,