From: Christian Brauner <brauner@kernel.org>
To: linux-fsdevel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org,
Alexander Viro <viro@zeniv.linux.org.uk>,
Jens Axboe <axboe@kernel.dk>, Jan Kara <jack@suse.cz>,
Tejun Heo <tj@kernel.org>, Jann Horn <jannh@google.com>,
Christian Brauner <brauner@kernel.org>
Subject: [PATCH RFC v2 21/23] nullfs: make nullfs multi-instance
Date: Fri, 06 Mar 2026 00:30:24 +0100 [thread overview]
Message-ID: <20260306-work-kthread-nullfs-v2-21-ad1b4bed7d3e@kernel.org> (raw)
In-Reply-To: <20260306-work-kthread-nullfs-v2-0-ad1b4bed7d3e@kernel.org>
Allow multiple instances of nullfs to be created. Right now we're only
going to use it for kernel-internal purposes but ultimately we can allow
userspace to use it too to e.g., safely overmount stuff.
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
fs/nullfs.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/fs/nullfs.c b/fs/nullfs.c
index fdbd3e5d3d71..88ba4f3fc3a2 100644
--- a/fs/nullfs.c
+++ b/fs/nullfs.c
@@ -40,14 +40,9 @@ static int nullfs_fs_fill_super(struct super_block *s, struct fs_context *fc)
return 0;
}
-/*
- * For now this is a single global instance. If needed we can make it
- * mountable by userspace at which point we will need to make it
- * multi-instance.
- */
static int nullfs_fs_get_tree(struct fs_context *fc)
{
- return get_tree_single(fc, nullfs_fs_fill_super);
+ return get_tree_nodev(fc, nullfs_fs_fill_super);
}
static const struct fs_context_operations nullfs_fs_context_ops = {
--
2.47.3
next prev parent reply other threads:[~2026-03-05 23:31 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-05 23:30 [PATCH RFC v2 00/23] fs,kthread: start all kthreads in nullfs Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 01/23] fs: notice when init abandons fs sharing Christian Brauner
2026-03-10 16:03 ` Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 02/23] fs: add scoped_with_init_fs() Christian Brauner
2026-03-09 15:19 ` Jann Horn
2026-03-10 11:30 ` Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 03/23] rnbd: use scoped_with_init_fs() for block device open Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 04/23] crypto: ccp: use scoped_with_init_fs() for SEV file access Christian Brauner
2026-03-09 15:37 ` Jann Horn
2026-03-10 11:33 ` Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 05/23] scsi: target: use scoped_with_init_fs() for ALUA metadata Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 06/23] scsi: target: use scoped_with_init_fs() for APTPL metadata Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 07/23] btrfs: use scoped_with_init_fs() for update_dev_time() Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 08/23] coredump: use scoped_with_init_fs() for coredump path resolution Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 09/23] fs: use scoped_with_init_fs() for kernel_read_file_from_path_initns() Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 10/23] ksmbd: use scoped_with_init_fs() for share path resolution Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 11/23] ksmbd: use scoped_with_init_fs() for filesystem info path lookup Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 12/23] ksmbd: use scoped_with_init_fs() for VFS path operations Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 13/23] initramfs: use scoped_with_init_fs() for rootfs unpacking Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 14/23] af_unix: use scoped_with_init_fs() for coredump socket lookup Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 15/23] fs: add real_fs to track task's actual fs_struct Christian Brauner
2026-03-07 0:51 ` Askar Safin
2026-03-09 15:14 ` Jann Horn
2026-03-10 11:29 ` Christian Brauner
2026-03-10 16:05 ` Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 16/23] fs: make userspace_init_fs a dynamically-initialized pointer Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 17/23] fs: stop sharing fs_struct between init_task and pid 1 Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 18/23] fs: add umh argument to struct kernel_clone_args Christian Brauner
2026-03-09 16:06 ` Jann Horn
2026-03-10 11:58 ` Christian Brauner
2026-03-05 23:30 ` [PATCH RFC v2 19/23] fs: add kthread_mntns() Christian Brauner
2026-03-07 2:04 ` Askar Safin
2026-03-05 23:30 ` [PATCH RFC v2 20/23] devtmpfs: create private mount namespace Christian Brauner
2026-03-05 23:30 ` Christian Brauner [this message]
2026-03-05 23:30 ` [PATCH RFC v2 22/23] fs: start all kthreads in nullfs Christian Brauner
2026-03-07 22:17 ` Askar Safin
2026-03-05 23:30 ` [PATCH RFC v2 23/23] fs: stop rewriting kthread fs structs Christian Brauner
2026-03-07 2:19 ` [PATCH RFC v2 00/23] fs,kthread: start all kthreads in nullfs Askar Safin
2026-03-09 16:50 ` Jann Horn
2026-03-10 12:54 ` Christian Brauner
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