From: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> To: Linux Containers <containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org> Cc: Miklos Szeredi <miklos-sUDqSbJrdHQHWmgEVkV9KA@public.gmane.org>, Andy Lutomirski <luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org>, James Bottomley <James.Bottomley-d9PhHud1JfjCXq6kfMZ53/egYHeGw8Jk@public.gmane.org>, Seth Forshee <seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Djalal Harouni <tixxdz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Subject: [PATCH review 13/13] userns: Remove the now unnecessary FS_USERNS_DEV_MOUNT flag Date: Mon, 20 Jun 2016 12:21:30 -0500 [thread overview] Message-ID: <20160620172130.15712-13-ebiederm@xmission.com> (raw) In-Reply-To: <20160620172130.15712-1-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> Now that SB_I_NODEV controls the nodev behavior devpts can just clear this flag during mount. Simplifying the code and making it easier to audit how the code works. While still preserving the invariant that s_iflags is only modified during mount. Signed-off-by: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> --- fs/devpts/inode.c | 3 ++- fs/super.c | 3 +-- include/linux/fs.h | 1 - 3 files changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c index 37c134a132c7..d116453b0276 100644 --- a/fs/devpts/inode.c +++ b/fs/devpts/inode.c @@ -396,6 +396,7 @@ devpts_fill_super(struct super_block *s, void *data, int silent) { struct inode *inode; + s->s_iflags &= ~SB_I_NODEV; s->s_blocksize = 1024; s->s_blocksize_bits = 10; s->s_magic = DEVPTS_SUPER_MAGIC; @@ -480,7 +481,7 @@ static struct file_system_type devpts_fs_type = { .name = "devpts", .mount = devpts_mount, .kill_sb = devpts_kill_sb, - .fs_flags = FS_USERNS_MOUNT | FS_USERNS_DEV_MOUNT, + .fs_flags = FS_USERNS_MOUNT, }; /* diff --git a/fs/super.c b/fs/super.c index 25cdceed2ad3..37813bf479cf 100644 --- a/fs/super.c +++ b/fs/super.c @@ -206,8 +206,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags, init_waitqueue_head(&s->s_writers.wait_unfrozen); s->s_bdi = &noop_backing_dev_info; s->s_flags = flags; - if ((s->s_user_ns != &init_user_ns) && - !(type->fs_flags & FS_USERNS_DEV_MOUNT)) + if (s->s_user_ns != &init_user_ns) s->s_iflags |= SB_I_NODEV; INIT_HLIST_NODE(&s->s_instances); INIT_HLIST_BL_HEAD(&s->s_anon); diff --git a/include/linux/fs.h b/include/linux/fs.h index e05983170d23..375e37f42cdf 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2022,7 +2022,6 @@ struct file_system_type { #define FS_BINARY_MOUNTDATA 2 #define FS_HAS_SUBTYPE 4 #define FS_USERNS_MOUNT 8 /* Can be mounted by userns root */ -#define FS_USERNS_DEV_MOUNT 16 /* A userns mount does not imply MNT_NODEV */ #define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() during rename() internally. */ struct dentry *(*mount) (struct file_system_type *, int, const char *, void *); -- 2.8.3
WARNING: multiple messages have this Message-ID (diff)
From: "Eric W. Biederman" <ebiederm@xmission.com> To: Linux Containers <containers@lists.linux-foundation.org> Cc: linux-fsdevel@vger.kernel.org, Miklos Szeredi <miklos@szeredi.hu>, James Bottomley <James.Bottomley@HansenPartnership.com>, Djalal Harouni <tixxdz@gmail.com>, Seth Forshee <seth.forshee@canonical.com>, "Serge E. Hallyn" <serge@hallyn.com>, Andy Lutomirski <luto@amacapital.net> Subject: [PATCH review 13/13] userns: Remove the now unnecessary FS_USERNS_DEV_MOUNT flag Date: Mon, 20 Jun 2016 12:21:30 -0500 [thread overview] Message-ID: <20160620172130.15712-13-ebiederm@xmission.com> (raw) In-Reply-To: <20160620172130.15712-1-ebiederm@xmission.com> Now that SB_I_NODEV controls the nodev behavior devpts can just clear this flag during mount. Simplifying the code and making it easier to audit how the code works. While still preserving the invariant that s_iflags is only modified during mount. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> --- fs/devpts/inode.c | 3 ++- fs/super.c | 3 +-- include/linux/fs.h | 1 - 3 files changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c index 37c134a132c7..d116453b0276 100644 --- a/fs/devpts/inode.c +++ b/fs/devpts/inode.c @@ -396,6 +396,7 @@ devpts_fill_super(struct super_block *s, void *data, int silent) { struct inode *inode; + s->s_iflags &= ~SB_I_NODEV; s->s_blocksize = 1024; s->s_blocksize_bits = 10; s->s_magic = DEVPTS_SUPER_MAGIC; @@ -480,7 +481,7 @@ static struct file_system_type devpts_fs_type = { .name = "devpts", .mount = devpts_mount, .kill_sb = devpts_kill_sb, - .fs_flags = FS_USERNS_MOUNT | FS_USERNS_DEV_MOUNT, + .fs_flags = FS_USERNS_MOUNT, }; /* diff --git a/fs/super.c b/fs/super.c index 25cdceed2ad3..37813bf479cf 100644 --- a/fs/super.c +++ b/fs/super.c @@ -206,8 +206,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags, init_waitqueue_head(&s->s_writers.wait_unfrozen); s->s_bdi = &noop_backing_dev_info; s->s_flags = flags; - if ((s->s_user_ns != &init_user_ns) && - !(type->fs_flags & FS_USERNS_DEV_MOUNT)) + if (s->s_user_ns != &init_user_ns) s->s_iflags |= SB_I_NODEV; INIT_HLIST_NODE(&s->s_instances); INIT_HLIST_BL_HEAD(&s->s_anon); diff --git a/include/linux/fs.h b/include/linux/fs.h index e05983170d23..375e37f42cdf 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2022,7 +2022,6 @@ struct file_system_type { #define FS_BINARY_MOUNTDATA 2 #define FS_HAS_SUBTYPE 4 #define FS_USERNS_MOUNT 8 /* Can be mounted by userns root */ -#define FS_USERNS_DEV_MOUNT 16 /* A userns mount does not imply MNT_NODEV */ #define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() during rename() internally. */ struct dentry *(*mount) (struct file_system_type *, int, const char *, void *); -- 2.8.3
next prev parent reply other threads:[~2016-06-20 17:21 UTC|newest] Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-06-20 17:09 [PATCH review 0/13] Adding a userns owner to struct super_block Eric W. Biederman 2016-06-20 17:09 ` Eric W. Biederman [not found] ` <87fus77pns.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org> 2016-06-20 17:21 ` [PATCH review 01/13] mnt: Account for MS_RDONLY in fs_fully_visible Eric W. Biederman 2016-06-20 17:21 ` Eric W. Biederman [not found] ` <20160620172130.15712-1-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> 2016-06-20 17:21 ` [PATCH review 02/13] mnt: Refactor fs_fully_visible into mount_too_revealing Eric W. Biederman 2016-06-20 17:21 ` Eric W. Biederman [not found] ` <20160620172130.15712-2-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> 2016-06-20 22:53 ` Andy Lutomirski 2016-06-20 22:53 ` Andy Lutomirski [not found] ` <CALCETrXv2aeP38AmUaRVMC+O-oeWKwDcy8fPfsOCu1f8mncZEA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2016-06-21 18:54 ` Eric W. Biederman 2016-06-21 18:54 ` Eric W. Biederman [not found] ` <874m8m4bky.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org> 2016-06-23 21:23 ` Djalal Harouni 2016-06-23 21:23 ` Djalal Harouni 2016-06-24 6:56 ` Serge E. Hallyn 2016-06-24 6:56 ` Serge E. Hallyn 2016-06-22 19:40 ` Seth Forshee 2016-06-22 19:40 ` Seth Forshee 2016-06-20 17:21 ` [PATCH review 03/13] ipc: Initialize ipc_namespace->user_ns early Eric W. Biederman 2016-06-20 17:21 ` Eric W. Biederman [not found] ` <20160620172130.15712-3-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> 2016-06-24 14:34 ` Djalal Harouni 2016-06-24 14:34 ` Djalal Harouni 2016-06-20 17:21 ` [PATCH review 04/13] vfs: Pass data, ns, and ns->userns to mount_ns Eric W. Biederman 2016-06-20 17:21 ` Eric W. Biederman 2016-06-20 17:21 ` [PATCH review 05/13] proc: Convert proc_mount to use mount_ns Eric W. Biederman 2016-06-20 17:21 ` Eric W. Biederman [not found] ` <20160620172130.15712-5-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> 2016-06-23 11:50 ` Djalal Harouni 2016-06-23 11:50 ` Djalal Harouni 2016-06-20 17:21 ` [PATCH review 06/13] fs: Add user namespace member to struct super_block Eric W. Biederman 2016-06-20 17:21 ` Eric W. Biederman 2016-06-20 17:21 ` [PATCH review 07/13] mnt: Move the FS_USERNS_MOUNT check into sget_userns Eric W. Biederman 2016-06-20 17:21 ` Eric W. Biederman [not found] ` <20160620172130.15712-7-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> 2016-06-22 19:43 ` Seth Forshee 2016-06-22 19:43 ` Seth Forshee 2016-06-20 17:21 ` [PATCH review 08/13] kernfs: The cgroup filesystem also benefits from SB_I_NOEXEC Eric W. Biederman 2016-06-20 17:21 ` Eric W. Biederman 2016-06-20 17:21 ` [PATCH review 09/13] ipc/mqueue: The mqueue filesystem should never contain executables Eric W. Biederman 2016-06-20 17:21 ` Eric W. Biederman 2016-06-20 17:21 ` [PATCH review 10/13] vfs: Generalize filesystem nodev handling Eric W. Biederman 2016-06-20 17:21 ` Eric W. Biederman [not found] ` <20160620172130.15712-10-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> 2016-06-20 22:57 ` Andy Lutomirski 2016-06-20 22:57 ` Andy Lutomirski [not found] ` <CALCETrUWsnRgjyRyb+_0u0PYubx9gg=hUAso=073yjJY+m205g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2016-06-21 19:09 ` Eric W. Biederman 2016-06-21 19:09 ` Eric W. Biederman 2016-06-20 17:21 ` [PATCH review 11/13] mnt: Simplify mount_too_revealing Eric W. Biederman 2016-06-20 17:21 ` Eric W. Biederman [not found] ` <20160620172130.15712-11-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> 2016-06-22 19:48 ` Seth Forshee 2016-06-22 19:48 ` Seth Forshee 2016-06-20 17:21 ` [PATCH review 12/13] userns: Remove implicit MNT_NODEV fragility Eric W. Biederman 2016-06-20 17:21 ` Eric W. Biederman 2016-06-22 19:49 ` Seth Forshee [not found] ` <20160620172130.15712-12-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> 2016-06-20 22:58 ` Andy Lutomirski 2016-06-20 22:58 ` Andy Lutomirski 2016-06-22 19:49 ` Seth Forshee 2016-06-20 17:21 ` Eric W. Biederman [this message] 2016-06-20 17:21 ` [PATCH review 13/13] userns: Remove the now unnecessary FS_USERNS_DEV_MOUNT flag Eric W. Biederman 2016-06-22 19:50 ` Seth Forshee [not found] ` <20160620172130.15712-13-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> 2016-06-22 19:50 ` Seth Forshee
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