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-rw-r--r--fs/sysfs/mount.c73
1 files changed, 54 insertions, 19 deletions
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 92682fcc41f6..4cb21b558a85 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -13,34 +13,69 @@
#include <linux/magic.h>
#include <linux/mount.h>
#include <linux/init.h>
+#include <linux/slab.h>
#include <linux/user_namespace.h>
+#include <linux/fs_context.h>
+#include <net/net_namespace.h>
#include "sysfs.h"
static struct kernfs_root *sysfs_root;
struct kernfs_node *sysfs_root_kn;
-static struct dentry *sysfs_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
+static int sysfs_get_tree(struct fs_context *fc)
{
- struct dentry *root;
- void *ns;
- bool new_sb = false;
+ struct kernfs_fs_context *kfc = fc->fs_private;
+ int ret;
- if (!(flags & SB_KERNMOUNT)) {
+ ret = kernfs_get_tree(fc);
+ if (ret)
+ return ret;
+
+ if (kfc->new_sb_created)
+ fc->root->d_sb->s_iflags |= SB_I_USERNS_VISIBLE;
+ return 0;
+}
+
+static void sysfs_fs_context_free(struct fs_context *fc)
+{
+ struct kernfs_fs_context *kfc = fc->fs_private;
+
+ if (kfc->ns_tag)
+ kobj_ns_drop(KOBJ_NS_TYPE_NET, kfc->ns_tag);
+ kernfs_free_fs_context(fc);
+ kfree(kfc);
+}
+
+static const struct fs_context_operations sysfs_fs_context_ops = {
+ .free = sysfs_fs_context_free,
+ .get_tree = sysfs_get_tree,
+};
+
+static int sysfs_init_fs_context(struct fs_context *fc)
+{
+ struct kernfs_fs_context *kfc;
+ struct net *netns;
+
+ if (!(fc->sb_flags & SB_KERNMOUNT)) {
if (!kobj_ns_current_may_mount(KOBJ_NS_TYPE_NET))
- return ERR_PTR(-EPERM);
+ return -EPERM;
}
- ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
- root = kernfs_mount_ns(fs_type, flags, sysfs_root,
- SYSFS_MAGIC, &new_sb, ns);
- if (!new_sb)
- kobj_ns_drop(KOBJ_NS_TYPE_NET, ns);
- else if (!IS_ERR(root))
- root->d_sb->s_iflags |= SB_I_USERNS_VISIBLE;
+ kfc = kzalloc(sizeof(struct kernfs_fs_context), GFP_KERNEL);
+ if (!kfc)
+ return -ENOMEM;
- return root;
+ kfc->ns_tag = netns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
+ kfc->root = sysfs_root;
+ kfc->magic = SYSFS_MAGIC;
+ fc->fs_private = kfc;
+ fc->ops = &sysfs_fs_context_ops;
+ if (fc->user_ns)
+ put_user_ns(fc->user_ns);
+ fc->user_ns = get_user_ns(netns->user_ns);
+ fc->global = true;
+ return 0;
}
static void sysfs_kill_sb(struct super_block *sb)
@@ -52,10 +87,10 @@ static void sysfs_kill_sb(struct super_block *sb)
}
static struct file_system_type sysfs_fs_type = {
- .name = "sysfs",
- .mount = sysfs_mount,
- .kill_sb = sysfs_kill_sb,
- .fs_flags = FS_USERNS_MOUNT,
+ .name = "sysfs",
+ .init_fs_context = sysfs_init_fs_context,
+ .kill_sb = sysfs_kill_sb,
+ .fs_flags = FS_USERNS_MOUNT,
};
int __init sysfs_init(void)