Commit 2dbf6e0d authored by Al Viro's avatar Al Viro
Browse files

kill vfs_submount() 



The last remaining user of vfs_submount() (tracefs) is easy to convert
to fs_context_for_submount(); do that and bury that thing, along with
SB_SUBMOUNT

Reviewed-by: default avatarJan Kara <jack@suse.cz>
Acked-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 006ff749

fs/namespace.c

+0 −15
Original line number Diff line number Diff line
@@ -1329,21 +1329,6 @@ struct vfsmount *vfs_kern_mount(struct file_system_type *type, 
}

EXPORT_SYMBOL_GPL(vfs_kern_mount);



struct vfsmount *

vfs_submount(const struct dentry *mountpoint, struct file_system_type *type,

	     const char *name, void *data)

{

	/* Until it is worked out how to pass the user namespace

	 * through from the parent mount to the submount don't support

	 * unprivileged mounts with submounts.

	 */

	if (mountpoint->d_sb->s_user_ns != &init_user_ns)

		return ERR_PTR(-EPERM);



	return vfs_kern_mount(type, SB_SUBMOUNT, name, data);

}

EXPORT_SYMBOL_GPL(vfs_submount);



static struct mount *clone_mnt(struct mount *old, struct dentry *root,

					int flag)

{

fs/super.c

+1 −8
Original line number Diff line number Diff line
@@ -823,13 +823,6 @@ struct super_block *sget(struct file_system_type *type, 
	struct super_block *old;

	int err;



	/* We don't yet pass the user namespace of the parent

	 * mount through to here so always use &init_user_ns

	 * until that changes.

	 */

	if (flags & SB_SUBMOUNT)

		user_ns = &init_user_ns;



retry:

	spin_lock(&sb_lock);

	if (test) {
@@ -849,7 +842,7 @@ struct super_block *sget(struct file_system_type *type, 
	}

	if (!s) {

		spin_unlock(&sb_lock);

		s = alloc_super(type, (flags & ~SB_SUBMOUNT), user_ns);

		s = alloc_super(type, flags, user_ns);

		if (!s)

			return ERR_PTR(-ENOMEM);

		goto retry;

include/linux/fs.h

+0 −1
Original line number Diff line number Diff line
@@ -1240,7 +1240,6 @@ extern int send_sigurg(struct file *file); 
/* These sb flags are internal to the kernel */

#define SB_DEAD         BIT(21)

#define SB_DYING        BIT(24)

#define SB_SUBMOUNT     BIT(26)

#define SB_FORCE        BIT(27)

#define SB_NOSEC        BIT(28)

#define SB_BORN         BIT(29)

include/linux/mount.h

+0 −3
Original line number Diff line number Diff line
@@ -98,9 +98,6 @@ extern struct vfsmount *vfs_create_mount(struct fs_context *fc); 
extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,

				      int flags, const char *name,

				      void *data);

extern struct vfsmount *vfs_submount(const struct dentry *mountpoint,

				     struct file_system_type *type,

				     const char *name, void *data);



extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list);

extern void mark_mounts_for_expiry(struct list_head *mounts);

kernel/trace/trace.c

+16 −3
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ 
#include <linux/workqueue.h>

#include <linux/sort.h>

#include <linux/io.h> /* vmap_page_range() */

#include <linux/fs_context.h>



#include <asm/setup.h> /* COMMAND_LINE_SIZE */
@@ -10075,6 +10076,8 @@ static struct vfsmount *trace_automount(struct dentry *mntpt, void *ingore) 
{

	struct vfsmount *mnt;

	struct file_system_type *type;

	struct fs_context *fc;

	int ret;



	/*

	 * To maintain backward compatibility for tools that mount
@@ -10084,10 +10087,20 @@ static struct vfsmount *trace_automount(struct dentry *mntpt, void *ingore) 
	type = get_fs_type("tracefs");

	if (!type)

		return NULL;

	mnt = vfs_submount(mntpt, type, "tracefs", NULL);



	fc = fs_context_for_submount(type, mntpt);

	put_filesystem(type);

	if (IS_ERR(mnt))

		return NULL;

	if (IS_ERR(fc))

		return ERR_CAST(fc);



	ret = vfs_parse_fs_string(fc, "source",

				  "tracefs", strlen("tracefs"));

	if (!ret)

		mnt = fc_mount(fc);

	else

		mnt = ERR_PTR(ret);



	put_fs_context(fc);

	return mnt;

}