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-rw-r--r--fs/super.c148
1 files changed, 44 insertions, 104 deletions
diff --git a/fs/super.c b/fs/super.c
index 2739f57515f8..113c58f19425 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -476,6 +476,17 @@ void generic_shutdown_super(struct super_block *sb)
EXPORT_SYMBOL(generic_shutdown_super);
+bool mount_capable(struct fs_context *fc)
+{
+ struct user_namespace *user_ns = fc->global ? &init_user_ns
+ : fc->user_ns;
+
+ if (!(fc->fs_type->fs_flags & FS_USERNS_MOUNT))
+ return capable(CAP_SYS_ADMIN);
+ else
+ return ns_capable(user_ns, CAP_SYS_ADMIN);
+}
+
/**
* sget_fc - Find or create a superblock
* @fc: Filesystem context.
@@ -503,20 +514,6 @@ struct super_block *sget_fc(struct fs_context *fc,
struct user_namespace *user_ns = fc->global ? &init_user_ns : fc->user_ns;
int err;
- if (!(fc->sb_flags & SB_KERNMOUNT) &&
- fc->purpose != FS_CONTEXT_FOR_SUBMOUNT) {
- /* Don't allow mounting unless the caller has CAP_SYS_ADMIN
- * over the namespace.
- */
- if (!(fc->fs_type->fs_flags & FS_USERNS_MOUNT)) {
- if (!capable(CAP_SYS_ADMIN))
- return ERR_PTR(-EPERM);
- } else {
- if (!ns_capable(fc->user_ns, CAP_SYS_ADMIN))
- return ERR_PTR(-EPERM);
- }
- }
-
retry:
spin_lock(&sb_lock);
if (test) {
@@ -543,6 +540,7 @@ retry:
}
fc->s_fs_info = NULL;
s->s_type = fc->fs_type;
+ s->s_iflags |= fc->s_iflags;
strlcpy(s->s_id, s->s_type->name, sizeof(s->s_id));
list_add_tail(&s->s_list, &super_blocks);
hlist_add_head(&s->s_instances, &s->s_type->fs_supers);
@@ -565,28 +563,31 @@ share_extant_sb:
EXPORT_SYMBOL(sget_fc);
/**
- * sget_userns - find or create a superblock
- * @type: filesystem type superblock should belong to
- * @test: comparison callback
- * @set: setup callback
- * @flags: mount flags
- * @user_ns: User namespace for the super_block
- * @data: argument to each of them
+ * sget - find or create a superblock
+ * @type: filesystem type superblock should belong to
+ * @test: comparison callback
+ * @set: setup callback
+ * @flags: mount flags
+ * @data: argument to each of them
*/
-struct super_block *sget_userns(struct file_system_type *type,
+struct super_block *sget(struct file_system_type *type,
int (*test)(struct super_block *,void *),
int (*set)(struct super_block *,void *),
- int flags, struct user_namespace *user_ns,
+ int flags,
void *data)
{
+ struct user_namespace *user_ns = current_user_ns();
struct super_block *s = NULL;
struct super_block *old;
int err;
- if (!(flags & (SB_KERNMOUNT|SB_SUBMOUNT)) &&
- !(type->fs_flags & FS_USERNS_MOUNT) &&
- !capable(CAP_SYS_ADMIN))
- return ERR_PTR(-EPERM);
+ /* 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) {
@@ -627,39 +628,6 @@ retry:
register_shrinker_prepared(&s->s_shrink);
return s;
}
-
-EXPORT_SYMBOL(sget_userns);
-
-/**
- * sget - find or create a superblock
- * @type: filesystem type superblock should belong to
- * @test: comparison callback
- * @set: setup callback
- * @flags: mount flags
- * @data: argument to each of them
- */
-struct super_block *sget(struct file_system_type *type,
- int (*test)(struct super_block *,void *),
- int (*set)(struct super_block *,void *),
- int flags,
- void *data)
-{
- struct user_namespace *user_ns = current_user_ns();
-
- /* 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;
-
- /* Ensure the requestor has permissions over the target filesystem */
- if (!(flags & (SB_KERNMOUNT|SB_SUBMOUNT)) && !ns_capable(user_ns, CAP_SYS_ADMIN))
- return ERR_PTR(-EPERM);
-
- return sget_userns(type, test, set, flags, user_ns, data);
-}
-
EXPORT_SYMBOL(sget);
void drop_super(struct super_block *sb)
@@ -1147,50 +1115,6 @@ void kill_litter_super(struct super_block *sb)
}
EXPORT_SYMBOL(kill_litter_super);
-static int ns_test_super(struct super_block *sb, void *data)
-{
- return sb->s_fs_info == data;
-}
-
-static int ns_set_super(struct super_block *sb, void *data)
-{
- sb->s_fs_info = data;
- return set_anon_super(sb, NULL);
-}
-
-struct dentry *mount_ns(struct file_system_type *fs_type,
- int flags, void *data, void *ns, struct user_namespace *user_ns,
- int (*fill_super)(struct super_block *, void *, int))
-{
- struct super_block *sb;
-
- /* Don't allow mounting unless the caller has CAP_SYS_ADMIN
- * over the namespace.
- */
- if (!(flags & SB_KERNMOUNT) && !ns_capable(user_ns, CAP_SYS_ADMIN))
- return ERR_PTR(-EPERM);
-
- sb = sget_userns(fs_type, ns_test_super, ns_set_super, flags,
- user_ns, ns);
- if (IS_ERR(sb))
- return ERR_CAST(sb);
-
- if (!sb->s_root) {
- int err;
- err = fill_super(sb, data, flags & SB_SILENT ? 1 : 0);
- if (err) {
- deactivate_locked_super(sb);
- return ERR_PTR(err);
- }
-
- sb->s_flags |= SB_ACTIVE;
- }
-
- return dget(sb->s_root);
-}
-
-EXPORT_SYMBOL(mount_ns);
-
int set_anon_super_fc(struct super_block *sb, struct fs_context *fc)
{
return set_anon_super(sb, NULL);
@@ -1274,6 +1198,22 @@ int vfs_get_super(struct fs_context *fc,
}
EXPORT_SYMBOL(vfs_get_super);
+int get_tree_nodev(struct fs_context *fc,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc))
+{
+ return vfs_get_super(fc, vfs_get_independent_super, fill_super);
+}
+EXPORT_SYMBOL(get_tree_nodev);
+
+int get_tree_single(struct fs_context *fc,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc))
+{
+ return vfs_get_super(fc, vfs_get_single_super, fill_super);
+}
+EXPORT_SYMBOL(get_tree_single);
+
#ifdef CONFIG_BLOCK
static int set_bdev_super(struct super_block *s, void *data)
{