diff options
Diffstat (limited to 'fs')
-rw-r--r-- | fs/kernfs/kernfs-internal.h | 1 | ||||
-rw-r--r-- | fs/kernfs/mount.c | 89 | ||||
-rw-r--r-- | fs/sysfs/mount.c | 73 |
3 files changed, 92 insertions, 71 deletions
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h index 3d83b114bb08..379e3a9eb1ec 100644 --- a/fs/kernfs/kernfs-internal.h +++ b/fs/kernfs/kernfs-internal.h @@ -17,6 +17,7 @@ #include <linux/xattr.h> #include <linux/kernfs.h> +#include <linux/fs_context.h> struct kernfs_iattrs { struct iattr ia_iattr; diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index 4d303047a4f8..36376cc5c9c2 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -22,16 +22,6 @@ struct kmem_cache *kernfs_node_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; } /** 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) |