diff options
Diffstat (limited to 'fs/kernfs/mount.c')
| -rw-r--r-- | fs/kernfs/mount.c | 119 |
1 files changed, 37 insertions, 82 deletions
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index f3ac352699cf..9a4646eecb71 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -22,16 +22,6 @@ struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache; -static int kernfs_sop_remount_fs(struct super_block *sb, int *flags, char *data) -{ - struct kernfs_root *root = kernfs_info(sb)->root; - struct kernfs_syscall_ops *scops = root->syscall_ops; - - if (scops && scops->remount_fs) - return scops->remount_fs(root, flags, data); - return 0; -} - static int kernfs_sop_show_options(struct seq_file *sf, struct dentry *dentry) { struct kernfs_root *root = kernfs_root(kernfs_dentry_node(dentry)); @@ -60,7 +50,6 @@ const struct super_operations kernfs_sops = { .drop_inode = generic_delete_inode, .evict_inode = kernfs_evict_inode, - .remount_fs = kernfs_sop_remount_fs, .show_options = kernfs_sop_show_options, .show_path = kernfs_sop_show_path, }; @@ -222,7 +211,7 @@ struct dentry *kernfs_node_dentry(struct kernfs_node *kn, } while (true); } -static int kernfs_fill_super(struct super_block *sb, unsigned long magic) +static int kernfs_fill_super(struct super_block *sb, struct kernfs_fs_context *kfc) { struct kernfs_super_info *info = kernfs_info(sb); struct inode *inode; @@ -233,7 +222,7 @@ static int kernfs_fill_super(struct super_block *sb, unsigned long magic) sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV; sb->s_blocksize = PAGE_SIZE; sb->s_blocksize_bits = PAGE_SHIFT; - sb->s_magic = magic; + sb->s_magic = kfc->magic; sb->s_op = &kernfs_sops; sb->s_xattr = kernfs_xattr_handlers; if (info->root->flags & KERNFS_ROOT_SUPPORT_EXPORTOP) @@ -263,21 +252,20 @@ static int kernfs_fill_super(struct super_block *sb, unsigned long magic) return 0; } -static int kernfs_test_super(struct super_block *sb, void *data) +static int kernfs_test_super(struct super_block *sb, struct fs_context *fc) { struct kernfs_super_info *sb_info = kernfs_info(sb); - struct kernfs_super_info *info = data; + struct kernfs_super_info *info = fc->s_fs_info; return sb_info->root == info->root && sb_info->ns == info->ns; } -static int kernfs_set_super(struct super_block *sb, void *data) +static int kernfs_set_super(struct super_block *sb, struct fs_context *fc) { - int error; - error = set_anon_super(sb, data); - if (!error) - sb->s_fs_info = data; - return error; + struct kernfs_fs_context *kfc = fc->fs_private; + + kfc->ns_tag = NULL; + return set_anon_super_fc(sb, fc); } /** @@ -294,63 +282,60 @@ const void *kernfs_super_ns(struct super_block *sb) } /** - * kernfs_mount_ns - kernfs mount helper - * @fs_type: file_system_type of the fs being mounted - * @flags: mount flags specified for the mount - * @root: kernfs_root of the hierarchy being mounted - * @magic: file system specific magic number - * @new_sb_created: tell the caller if we allocated a new superblock - * @ns: optional namespace tag of the mount + * kernfs_get_tree - kernfs filesystem access/retrieval helper + * @fc: The filesystem context. * - * This is to be called from each kernfs user's file_system_type->mount() - * implementation, which should pass through the specified @fs_type and - * @flags, and specify the hierarchy and namespace tag to mount via @root - * and @ns, respectively. - * - * The return value can be passed to the vfs layer verbatim. + * This is to be called from each kernfs user's fs_context->ops->get_tree() + * implementation, which should set the specified ->@fs_type and ->@flags, and + * specify the hierarchy and namespace tag to mount via ->@root and ->@ns, + * respectively. */ -struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags, - struct kernfs_root *root, unsigned long magic, - bool *new_sb_created, const void *ns) +int kernfs_get_tree(struct fs_context *fc) { + struct kernfs_fs_context *kfc = fc->fs_private; struct super_block *sb; struct kernfs_super_info *info; int error; info = kzalloc(sizeof(*info), GFP_KERNEL); if (!info) - return ERR_PTR(-ENOMEM); + return -ENOMEM; - info->root = root; - info->ns = ns; + info->root = kfc->root; + info->ns = kfc->ns_tag; INIT_LIST_HEAD(&info->node); - sb = sget_userns(fs_type, kernfs_test_super, kernfs_set_super, flags, - &init_user_ns, info); - if (IS_ERR(sb) || sb->s_fs_info != info) - kfree(info); + fc->s_fs_info = info; + sb = sget_fc(fc, kernfs_test_super, kernfs_set_super); if (IS_ERR(sb)) - return ERR_CAST(sb); - - if (new_sb_created) - *new_sb_created = !sb->s_root; + return PTR_ERR(sb); if (!sb->s_root) { struct kernfs_super_info *info = kernfs_info(sb); - error = kernfs_fill_super(sb, magic); + kfc->new_sb_created = true; + + error = kernfs_fill_super(sb, kfc); if (error) { deactivate_locked_super(sb); - return ERR_PTR(error); + return error; } sb->s_flags |= SB_ACTIVE; mutex_lock(&kernfs_mutex); - list_add(&info->node, &root->supers); + list_add(&info->node, &info->root->supers); mutex_unlock(&kernfs_mutex); } - return dget(sb->s_root); + fc->root = dget(sb->s_root); + return 0; +} + +void kernfs_free_fs_context(struct fs_context *fc) +{ + /* Note that we don't deal with kfc->ns_tag here. */ + kfree(fc->s_fs_info); + fc->s_fs_info = NULL; } /** @@ -377,36 +362,6 @@ void kernfs_kill_sb(struct super_block *sb) kfree(info); } -/** - * kernfs_pin_sb: try to pin the superblock associated with a kernfs_root - * @kernfs_root: the kernfs_root in question - * @ns: the namespace tag - * - * Pin the superblock so the superblock won't be destroyed in subsequent - * operations. This can be used to block ->kill_sb() which may be useful - * for kernfs users which dynamically manage superblocks. - * - * Returns NULL if there's no superblock associated to this kernfs_root, or - * -EINVAL if the superblock is being freed. - */ -struct super_block *kernfs_pin_sb(struct kernfs_root *root, const void *ns) -{ - struct kernfs_super_info *info; - struct super_block *sb = NULL; - - mutex_lock(&kernfs_mutex); - list_for_each_entry(info, &root->supers, node) { - if (info->ns == ns) { - sb = info->sb; - if (!atomic_inc_not_zero(&info->sb->s_active)) - sb = ERR_PTR(-EINVAL); - break; - } - } - mutex_unlock(&kernfs_mutex); - return sb; -} - void __init kernfs_init(void) { |