diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index 822b7db634ee..e49b77283924 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -4,6 +4,7 @@ #include #include +#include #include #define MSR_IA32_L3_QOS_CFG 0xc81 @@ -40,6 +41,21 @@ #define RMID_VAL_ERROR BIT_ULL(63) #define RMID_VAL_UNAVAIL BIT_ULL(62) + +struct rdt_fs_context { + struct kernfs_fs_context kfc; + bool enable_cdpl2; + bool enable_cdpl3; + bool enable_mba_mbps; +}; + +static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc) +{ + struct kernfs_fs_context *kfc = fc->fs_private; + + return container_of(kfc, struct rdt_fs_context, kfc); +} + DECLARE_STATIC_KEY_FALSE(rdt_enable_key); /** diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 8388adf241b2..399601eda8e4 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -32,6 +33,7 @@ #include #include #include +#include #include @@ -1858,46 +1860,6 @@ static void cdp_disable_all(void) cdpl2_disable(); } -static int parse_rdtgroupfs_options(char *data) -{ - char *token, *o = data; - int ret = 0; - - while ((token = strsep(&o, ",")) != NULL) { - if (!*token) { - ret = -EINVAL; - goto out; - } - - if (!strcmp(token, "cdp")) { - ret = cdpl3_enable(); - if (ret) - goto out; - } else if (!strcmp(token, "cdpl2")) { - ret = cdpl2_enable(); - if (ret) - goto out; - } else if (!strcmp(token, "mba_MBps")) { - if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) - ret = set_mba_sc(true); - else - ret = -EINVAL; - if (ret) - goto out; - } else { - ret = -EINVAL; - goto out; - } - } - - return 0; - -out: - pr_err("Invalid mount option \"%s\"\n", token); - - return ret; -} - /* * We don't allow rdtgroup directories to be created anywhere * except the root directory. Thus when looking for the rdtgroup @@ -1969,13 +1931,27 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn, struct rdtgroup *prgrp, struct kernfs_node **mon_data_kn); -static struct dentry *rdt_mount(struct file_system_type *fs_type, - int flags, const char *unused_dev_name, - void *data) +static int rdt_enable_ctx(struct rdt_fs_context *ctx) { + int ret = 0; + + if (ctx->enable_cdpl2) + ret = cdpl2_enable(); + + if (!ret && ctx->enable_cdpl3) + ret = cdpl3_enable(); + + if (!ret && ctx->enable_mba_mbps) + ret = set_mba_sc(true); + + return ret; +} + +static int rdt_get_tree(struct fs_context *fc) +{ + struct rdt_fs_context *ctx = rdt_fc2context(fc); struct rdt_domain *dom; struct rdt_resource *r; - struct dentry *dentry; int ret; cpus_read_lock(); @@ -1984,53 +1960,42 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type, * resctrl file system can only be mounted once. */ if (static_branch_unlikely(&rdt_enable_key)) { - dentry = ERR_PTR(-EBUSY); + ret = -EBUSY; goto out; } - ret = parse_rdtgroupfs_options(data); - if (ret) { - dentry = ERR_PTR(ret); + ret = rdt_enable_ctx(ctx); + if (ret < 0) goto out_cdp; - } closid_init(); ret = rdtgroup_create_info_dir(rdtgroup_default.kn); - if (ret) { - dentry = ERR_PTR(ret); - goto out_cdp; - } + if (ret < 0) + goto out_mba; if (rdt_mon_capable) { ret = mongroup_create_dir(rdtgroup_default.kn, NULL, "mon_groups", &kn_mongrp); - if (ret) { - dentry = ERR_PTR(ret); + if (ret < 0) goto out_info; - } kernfs_get(kn_mongrp); ret = mkdir_mondata_all(rdtgroup_default.kn, &rdtgroup_default, &kn_mondata); - if (ret) { - dentry = ERR_PTR(ret); + if (ret < 0) goto out_mongrp; - } kernfs_get(kn_mondata); rdtgroup_default.mon.mon_data_kn = kn_mondata; } ret = rdt_pseudo_lock_init(); - if (ret) { - dentry = ERR_PTR(ret); + if (ret) goto out_mondata; - } - dentry = kernfs_mount(fs_type, flags, rdt_root, - RDTGROUP_SUPER_MAGIC, NULL); - if (IS_ERR(dentry)) + ret = kernfs_get_tree(fc); + if (ret < 0) goto out_psl; if (rdt_alloc_capable) @@ -2059,14 +2024,95 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type, kernfs_remove(kn_mongrp); out_info: kernfs_remove(kn_info); +out_mba: + if (ctx->enable_mba_mbps) + set_mba_sc(false); out_cdp: cdp_disable_all(); out: rdt_last_cmd_clear(); mutex_unlock(&rdtgroup_mutex); cpus_read_unlock(); + return ret; +} - return dentry; +enum rdt_param { + Opt_cdp, + Opt_cdpl2, + Opt_mba_mpbs, + nr__rdt_params +}; + +static const struct fs_parameter_spec rdt_param_specs[] = { + fsparam_flag("cdp", Opt_cdp), + fsparam_flag("cdpl2", Opt_cdpl2), + fsparam_flag("mba_mpbs", Opt_mba_mpbs), + {} +}; + +static const struct fs_parameter_description rdt_fs_parameters = { + .name = "rdt", + .specs = rdt_param_specs, +}; + +static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param) +{ + struct rdt_fs_context *ctx = rdt_fc2context(fc); + struct fs_parse_result result; + int opt; + + opt = fs_parse(fc, &rdt_fs_parameters, param, &result); + if (opt < 0) + return opt; + + switch (opt) { + case Opt_cdp: + ctx->enable_cdpl3 = true; + return 0; + case Opt_cdpl2: + ctx->enable_cdpl2 = true; + return 0; + case Opt_mba_mpbs: + if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) + return -EINVAL; + ctx->enable_mba_mbps = true; + return 0; + } + + return -EINVAL; +} + +static void rdt_fs_context_free(struct fs_context *fc) +{ + struct rdt_fs_context *ctx = rdt_fc2context(fc); + + kernfs_free_fs_context(fc); + kfree(ctx); +} + +static const struct fs_context_operations rdt_fs_context_ops = { + .free = rdt_fs_context_free, + .parse_param = rdt_parse_param, + .get_tree = rdt_get_tree, +}; + +static int rdt_init_fs_context(struct fs_context *fc) +{ + struct rdt_fs_context *ctx; + + ctx = kzalloc(sizeof(struct rdt_fs_context), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + + ctx->kfc.root = rdt_root; + ctx->kfc.magic = RDTGROUP_SUPER_MAGIC; + fc->fs_private = &ctx->kfc; + fc->ops = &rdt_fs_context_ops; + if (fc->user_ns) + put_user_ns(fc->user_ns); + fc->user_ns = get_user_ns(&init_user_ns); + fc->global = true; + return 0; } static int reset_all_ctrls(struct rdt_resource *r) @@ -2239,9 +2285,10 @@ static void rdt_kill_sb(struct super_block *sb) } static struct file_system_type rdt_fs_type = { - .name = "resctrl", - .mount = rdt_mount, - .kill_sb = rdt_kill_sb, + .name = "resctrl", + .init_fs_context = rdt_init_fs_context, + .parameters = &rdt_fs_parameters, + .kill_sb = rdt_kill_sb, }; static int mon_addfile(struct kernfs_node *parent_kn, const char *name, 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 #include +#include 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 #include #include +#include #include +#include +#include #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) diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 44acb4c3659c..822a64e65b41 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -25,7 +25,9 @@ struct seq_file; struct vm_area_struct; struct super_block; struct file_system_type; +struct fs_context; +struct kernfs_fs_context; struct kernfs_open_node; struct kernfs_iattrs; @@ -167,7 +169,6 @@ struct kernfs_node { * kernfs_node parameter. */ struct kernfs_syscall_ops { - int (*remount_fs)(struct kernfs_root *root, int *flags, char *data); int (*show_options)(struct seq_file *sf, struct kernfs_root *root); int (*mkdir)(struct kernfs_node *parent, const char *name, @@ -268,6 +269,18 @@ struct kernfs_ops { #endif }; +/* + * The kernfs superblock creation/mount parameter context. + */ +struct kernfs_fs_context { + struct kernfs_root *root; /* Root of the hierarchy being mounted */ + void *ns_tag; /* Namespace tag of the mount (or NULL) */ + unsigned long magic; /* File system specific magic number */ + + /* The following are set/used by kernfs_mount() */ + bool new_sb_created; /* Set to T if we allocated a new sb */ +}; + #ifdef CONFIG_KERNFS static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn) @@ -353,9 +366,8 @@ int kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr); void kernfs_notify(struct kernfs_node *kn); const void *kernfs_super_ns(struct super_block *sb); -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); +void kernfs_free_fs_context(struct fs_context *fc); void kernfs_kill_sb(struct super_block *sb); void kernfs_init(void); @@ -458,11 +470,10 @@ static inline void kernfs_notify(struct kernfs_node *kn) { } static inline const void *kernfs_super_ns(struct super_block *sb) { return NULL; } -static inline 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) -{ return ERR_PTR(-ENOSYS); } +static inline int kernfs_get_tree(struct fs_context *fc) +{ return -ENOSYS; } + +static inline void kernfs_free_fs_context(struct fs_context *fc) { } static inline void kernfs_kill_sb(struct super_block *sb) { } @@ -545,13 +556,4 @@ static inline int kernfs_rename(struct kernfs_node *kn, return kernfs_rename_ns(kn, new_parent, new_name, NULL); } -static inline struct dentry * -kernfs_mount(struct file_system_type *fs_type, int flags, - struct kernfs_root *root, unsigned long magic, - bool *new_sb_created) -{ - return kernfs_mount_ns(fs_type, flags, root, - magic, new_sb_created, NULL); -} - #endif /* __LINUX_KERNFS_H */ diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h index 37cf709b7a0e..30e39f3932ad 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -41,6 +41,7 @@ extern void __init enable_debug_cgroup(void); * The cgroup filesystem superblock creation/mount context. */ struct cgroup_fs_context { + struct kernfs_fs_context kfc; struct cgroup_root *root; struct cgroup_namespace *ns; unsigned int flags; /* CGRP_ROOT_* flags */ @@ -56,7 +57,9 @@ struct cgroup_fs_context { static inline struct cgroup_fs_context *cgroup_fc2context(struct fs_context *fc) { - return fc->fs_private; + struct kernfs_fs_context *kfc = fc->fs_private; + + return container_of(kfc, struct cgroup_fs_context, kfc); } /* diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 0c6bef234a7c..747e5b17f9da 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2039,18 +2039,14 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) int cgroup_do_get_tree(struct fs_context *fc) { struct cgroup_fs_context *ctx = cgroup_fc2context(fc); - bool new_sb = false; - unsigned long magic; - int ret = 0; + int ret; + ctx->kfc.root = ctx->root->kf_root; if (fc->fs_type == &cgroup2_fs_type) - magic = CGROUP2_SUPER_MAGIC; + ctx->kfc.magic = CGROUP2_SUPER_MAGIC; else - magic = CGROUP_SUPER_MAGIC; - fc->root = kernfs_mount(fc->fs_type, fc->sb_flags, ctx->root->kf_root, - magic, &new_sb); - if (IS_ERR(fc->root)) - ret = PTR_ERR(fc->root); + ctx->kfc.magic = CGROUP_SUPER_MAGIC; + ret = kernfs_get_tree(fc); /* * In non-init cgroup namespace, instead of root cgroup's dentry, @@ -2078,7 +2074,7 @@ int cgroup_do_get_tree(struct fs_context *fc) } } - if (!new_sb) + if (!ctx->kfc.new_sb_created) cgroup_put(&ctx->root->cgrp); return ret; @@ -2094,19 +2090,15 @@ static void cgroup_fs_context_free(struct fs_context *fc) kfree(ctx->name); kfree(ctx->release_agent); put_cgroup_ns(ctx->ns); + kernfs_free_fs_context(fc); kfree(ctx); } static int cgroup_get_tree(struct fs_context *fc) { - struct cgroup_namespace *ns = current->nsproxy->cgroup_ns; struct cgroup_fs_context *ctx = cgroup_fc2context(fc); int ret; - /* Check if the caller has permission to mount. */ - if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN)) - return -EPERM; - cgrp_dfl_visible = true; cgroup_get_live(&cgrp_dfl_root.cgrp); ctx->root = &cgrp_dfl_root; @@ -2132,7 +2124,8 @@ static const struct fs_context_operations cgroup1_fs_context_ops = { }; /* - * Initialise the cgroup filesystem creation/reconfiguration context. + * Initialise the cgroup filesystem creation/reconfiguration context. Notably, + * we select the namespace we're going to use. */ static int cgroup_init_fs_context(struct fs_context *fc) { @@ -2151,11 +2144,15 @@ static int cgroup_init_fs_context(struct fs_context *fc) ctx->ns = current->nsproxy->cgroup_ns; get_cgroup_ns(ctx->ns); - fc->fs_private = ctx; + fc->fs_private = &ctx->kfc; if (fc->fs_type == &cgroup2_fs_type) fc->ops = &cgroup_fs_context_ops; else fc->ops = &cgroup1_fs_context_ops; + if (fc->user_ns) + put_user_ns(fc->user_ns); + fc->user_ns = get_user_ns(ctx->ns->user_ns); + fc->global = true; return 0; }