Now that the v1 mount code is split into separate functions, move them
to kernel/cgroup/cgroup-v1.c along with the mount option handling
code. As this puts all v1-only kernfs_syscall_ops in cgroup-v1.c,
move cgroup1_kf_syscall_ops to cgroup-v1.c too.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
kernel/cgroup/cgroup-internal.h | 28 ++-
kernel/cgroup/cgroup-v1.c | 381 ++++++++++++++++++++++++++++++++++++-
kernel/cgroup/cgroup.c | 410 +---------------------------------------
3 files changed, 413 insertions(+), 406 deletions(-)
diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h
index 7b8182e..3d431b6 100644
--- a/kernel/cgroup/cgroup-internal.h
+++ b/kernel/cgroup/cgroup-internal.h
@@ -26,6 +26,16 @@ struct cgrp_cset_link {
struct list_head cgrp_link;
};
+struct cgroup_sb_opts {
+ u16 subsys_mask;
+ unsigned int flags;
+ char *release_agent;
+ bool cpuset_clone_children;
+ char *name;
+ /* User explicitly requested empty subsystem */
+ bool none;
+};
+
extern struct cgroup_subsys *cgroup_subsys[];
extern struct list_head cgroup_roots;
extern struct file_system_type cgroup_fs_type;
@@ -64,7 +74,13 @@ void cgroup_kn_unlock(struct kernfs_node *kn);
int cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen,
struct cgroup_namespace *ns);
+void cgroup_free_root(struct cgroup_root *root);
+void init_cgroup_root(struct cgroup_root *root, struct cgroup_sb_opts *opts);
+int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask);
int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask);
+struct dentry *cgroup_do_mount(struct file_system_type *fs_type, int flags,
+ struct cgroup_root *root, unsigned long magic,
+ struct cgroup_namespace *ns);
bool cgroup_may_migrate_to(struct cgroup *dst_cgrp);
void cgroup_migrate_finish(struct list_head *preloaded_csets);
@@ -84,18 +100,24 @@ ssize_t cgroup_procs_write(struct kernfs_open_file *of, char *buf, size_t nbytes
void cgroup_lock_and_drain_offline(struct cgroup *cgrp);
+int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode);
+int cgroup_rmdir(struct kernfs_node *kn);
+int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
+ struct kernfs_root *kf_root);
+
/*
* cgroup-v1.c
*/
-extern spinlock_t release_agent_path_lock;
extern struct cftype cgroup_legacy_base_files[];
extern const struct file_operations proc_cgroupstats_operations;
+extern struct kernfs_syscall_ops cgroup1_kf_syscall_ops;
bool cgroup_ssid_no_v1(int ssid);
void cgroup_pidlist_destroy_all(struct cgroup *cgrp);
-int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
- const char *new_name_str);
void cgroup_release_agent(struct work_struct *work);
void check_for_release(struct cgroup *cgrp);
+struct dentry *cgroup1_mount(struct file_system_type *fs_type, int flags,
+ void *data, unsigned long magic,
+ struct cgroup_namespace *ns);
#endif /* __CGROUP_INTERNAL_H */
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 0b2c24f..ae240c0 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -1,7 +1,9 @@
#include "cgroup-internal.h"
+#include <linux/ctype.h>
#include <linux/kmod.h>
#include <linux/sort.h>
+#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
@@ -32,7 +34,7 @@ static struct workqueue_struct *cgroup_pidlist_destroy_wq;
* Protects cgroup_subsys->release_agent_path. Modifying it also requires
* cgroup_mutex. Reading requires either cgroup_mutex or this spinlock.
*/
-DEFINE_SPINLOCK(release_agent_path_lock);
+static DEFINE_SPINLOCK(release_agent_path_lock);
bool cgroup_ssid_no_v1(int ssid)
{
@@ -800,8 +802,8 @@ void cgroup_release_agent(struct work_struct *work)
/*
* cgroup_rename - Only allow simple rename of directories in place.
*/
-int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
- const char *new_name_str)
+static int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
+ const char *new_name_str)
{
struct cgroup *cgrp = kn->priv;
int ret;
@@ -832,6 +834,379 @@ int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
return ret;
}
+static int cgroup1_show_options(struct seq_file *seq, struct kernfs_root *kf_root)
+{
+ struct cgroup_root *root = cgroup_root_from_kf(kf_root);
+ struct cgroup_subsys *ss;
+ int ssid;
+
+ for_each_subsys(ss, ssid)
+ if (root->subsys_mask & (1 << ssid))
+ seq_show_option(seq, ss->legacy_name, NULL);
+ if (root->flags & CGRP_ROOT_NOPREFIX)
+ seq_puts(seq, ",noprefix");
+ if (root->flags & CGRP_ROOT_XATTR)
+ seq_puts(seq, ",xattr");
+
+ spin_lock(&release_agent_path_lock);
+ if (strlen(root->release_agent_path))
+ seq_show_option(seq, "release_agent",
+ root->release_agent_path);
+ spin_unlock(&release_agent_path_lock);
+
+ if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags))
+ seq_puts(seq, ",clone_children");
+ if (strlen(root->name))
+ seq_show_option(seq, "name", root->name);
+ return 0;
+}
+
+static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
+{
+ char *token, *o = data;
+ bool all_ss = false, one_ss = false;
+ u16 mask = U16_MAX;
+ struct cgroup_subsys *ss;
+ int nr_opts = 0;
+ int i;
+
+#ifdef CONFIG_CPUSETS
+ mask = ~((u16)1 << cpuset_cgrp_id);
+#endif
+
+ memset(opts, 0, sizeof(*opts));
+
+ while ((token = strsep(&o, ",")) != NULL) {
+ nr_opts++;
+
+ if (!*token)
+ return -EINVAL;
+ if (!strcmp(token, "none")) {
+ /* Explicitly have no subsystems */
+ opts->none = true;
+ continue;
+ }
+ if (!strcmp(token, "all")) {
+ /* Mutually exclusive option 'all' + subsystem name */
+ if (one_ss)
+ return -EINVAL;
+ all_ss = true;
+ continue;
+ }
+ if (!strcmp(token, "noprefix")) {
+ opts->flags |= CGRP_ROOT_NOPREFIX;
+ continue;
+ }
+ if (!strcmp(token, "clone_children")) {
+ opts->cpuset_clone_children = true;
+ continue;
+ }
+ if (!strcmp(token, "xattr")) {
+ opts->flags |= CGRP_ROOT_XATTR;
+ continue;
+ }
+ if (!strncmp(token, "release_agent=", 14)) {
+ /* Specifying two release agents is forbidden */
+ if (opts->release_agent)
+ return -EINVAL;
+ opts->release_agent =
+ kstrndup(token + 14, PATH_MAX - 1, GFP_KERNEL);
+ if (!opts->release_agent)
+ return -ENOMEM;
+ continue;
+ }
+ if (!strncmp(token, "name=", 5)) {
+ const char *name = token + 5;
+ /* Can't specify an empty name */
+ if (!strlen(name))
+ return -EINVAL;
+ /* Must match [\w.-]+ */
+ for (i = 0; i < strlen(name); i++) {
+ char c = name[i];
+ if (isalnum(c))
+ continue;
+ if ((c == '.') || (c == '-') || (c == '_'))
+ continue;
+ return -EINVAL;
+ }
+ /* Specifying two names is forbidden */
+ if (opts->name)
+ return -EINVAL;
+ opts->name = kstrndup(name,
+ MAX_CGROUP_ROOT_NAMELEN - 1,
+ GFP_KERNEL);
+ if (!opts->name)
+ return -ENOMEM;
+
+ continue;
+ }
+
+ for_each_subsys(ss, i) {
+ if (strcmp(token, ss->legacy_name))
+ continue;
+ if (!cgroup_ssid_enabled(i))
+ continue;
+ if (cgroup_ssid_no_v1(i))
+ continue;
+
+ /* Mutually exclusive option 'all' + subsystem name */
+ if (all_ss)
+ return -EINVAL;
+ opts->subsys_mask |= (1 << i);
+ one_ss = true;
+
+ break;
+ }
+ if (i == CGROUP_SUBSYS_COUNT)
+ return -ENOENT;
+ }
+
+ /*
+ * If the 'all' option was specified select all the subsystems,
+ * otherwise if 'none', 'name=' and a subsystem name options were
+ * not specified, let's default to 'all'
+ */
+ if (all_ss || (!one_ss && !opts->none && !opts->name))
+ for_each_subsys(ss, i)
+ if (cgroup_ssid_enabled(i) && !cgroup_ssid_no_v1(i))
+ opts->subsys_mask |= (1 << i);
+
+ /*
+ * We either have to specify by name or by subsystems. (So all
+ * empty hierarchies must have a name).
+ */
+ if (!opts->subsys_mask && !opts->name)
+ return -EINVAL;
+
+ /*
+ * Option noprefix was introduced just for backward compatibility
+ * with the old cpuset, so we allow noprefix only if mounting just
+ * the cpuset subsystem.
+ */
+ if ((opts->flags & CGRP_ROOT_NOPREFIX) && (opts->subsys_mask & mask))
+ return -EINVAL;
+
+ /* Can't specify "none" and some subsystems */
+ if (opts->subsys_mask && opts->none)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int cgroup1_remount(struct kernfs_root *kf_root, int *flags, char *data)
+{
+ int ret = 0;
+ struct cgroup_root *root = cgroup_root_from_kf(kf_root);
+ struct cgroup_sb_opts opts;
+ u16 added_mask, removed_mask;
+
+ cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
+
+ /* See what subsystems are wanted */
+ ret = parse_cgroupfs_options(data, &opts);
+ if (ret)
+ goto out_unlock;
+
+ if (opts.subsys_mask != root->subsys_mask || opts.release_agent)
+ pr_warn("option changes via remount are deprecated (pid=%d comm=%s)\n",
+ task_tgid_nr(current), current->comm);
+
+ added_mask = opts.subsys_mask & ~root->subsys_mask;
+ removed_mask = root->subsys_mask & ~opts.subsys_mask;
+
+ /* Don't allow flags or name to change at remount */
+ if ((opts.flags ^ root->flags) ||
+ (opts.name && strcmp(opts.name, root->name))) {
+ pr_err("option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"\n",
+ opts.flags, opts.name ?: "", root->flags, root->name);
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ /* remounting is not allowed for populated hierarchies */
+ if (!list_empty(&root->cgrp.self.children)) {
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+
+ ret = rebind_subsystems(root, added_mask);
+ if (ret)
+ goto out_unlock;
+
+ WARN_ON(rebind_subsystems(&cgrp_dfl_root, removed_mask));
+
+ if (opts.release_agent) {
+ spin_lock(&release_agent_path_lock);
+ strcpy(root->release_agent_path, opts.release_agent);
+ spin_unlock(&release_agent_path_lock);
+ }
+
+ trace_cgroup_remount(root);
+
+ out_unlock:
+ kfree(opts.release_agent);
+ kfree(opts.name);
+ mutex_unlock(&cgroup_mutex);
+ return ret;
+}
+
+struct kernfs_syscall_ops cgroup1_kf_syscall_ops = {
+ .rename = cgroup1_rename,
+ .show_options = cgroup1_show_options,
+ .remount_fs = cgroup1_remount,
+ .mkdir = cgroup_mkdir,
+ .rmdir = cgroup_rmdir,
+ .show_path = cgroup_show_path,
+};
+
+struct dentry *cgroup1_mount(struct file_system_type *fs_type, int flags,
+ void *data, unsigned long magic,
+ struct cgroup_namespace *ns)
+{
+ struct super_block *pinned_sb = NULL;
+ struct cgroup_sb_opts opts;
+ struct cgroup_root *root;
+ struct cgroup_subsys *ss;
+ struct dentry *dentry;
+ int i, ret;
+
+ cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
+
+ /* First find the desired set of subsystems */
+ ret = parse_cgroupfs_options(data, &opts);
+ if (ret)
+ goto out_unlock;
+
+ /*
+ * Destruction of cgroup root is asynchronous, so subsystems may
+ * still be dying after the previous unmount. Let's drain the
+ * dying subsystems. We just need to ensure that the ones
+ * unmounted previously finish dying and don't care about new ones
+ * starting. Testing ref liveliness is good enough.
+ */
+ for_each_subsys(ss, i) {
+ if (!(opts.subsys_mask & (1 << i)) ||
+ ss->root == &cgrp_dfl_root)
+ continue;
+
+ if (!percpu_ref_tryget_live(&ss->root->cgrp.self.refcnt)) {
+ mutex_unlock(&cgroup_mutex);
+ msleep(10);
+ ret = restart_syscall();
+ goto out_free;
+ }
+ cgroup_put(&ss->root->cgrp);
+ }
+
+ for_each_root(root) {
+ bool name_match = false;
+
+ if (root == &cgrp_dfl_root)
+ continue;
+
+ /*
+ * If we asked for a name then it must match. Also, if
+ * name matches but sybsys_mask doesn't, we should fail.
+ * Remember whether name matched.
+ */
+ if (opts.name) {
+ if (strcmp(opts.name, root->name))
+ continue;
+ name_match = true;
+ }
+
+ /*
+ * If we asked for subsystems (or explicitly for no
+ * subsystems) then they must match.
+ */
+ if ((opts.subsys_mask || opts.none) &&
+ (opts.subsys_mask != root->subsys_mask)) {
+ if (!name_match)
+ continue;
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+
+ if (root->flags ^ opts.flags)
+ pr_warn("new mount options do not match the existing superblock, will be ignored\n");
+
+ /*
+ * We want to reuse @root whose lifetime is governed by its
+ * ->cgrp. Let's check whether @root is alive and keep it
+ * that way. As cgroup_kill_sb() can happen anytime, we
+ * want to block it by pinning the sb so that @root doesn't
+ * get killed before mount is complete.
+ *
+ * With the sb pinned, tryget_live can reliably indicate
+ * whether @root can be reused. If it's being killed,
+ * drain it. We can use wait_queue for the wait but this
+ * path is super cold. Let's just sleep a bit and retry.
+ */
+ pinned_sb = kernfs_pin_sb(root->kf_root, NULL);
+ if (IS_ERR(pinned_sb) ||
+ !percpu_ref_tryget_live(&root->cgrp.self.refcnt)) {
+ mutex_unlock(&cgroup_mutex);
+ if (!IS_ERR_OR_NULL(pinned_sb))
+ deactivate_super(pinned_sb);
+ msleep(10);
+ ret = restart_syscall();
+ goto out_free;
+ }
+
+ ret = 0;
+ goto out_unlock;
+ }
+
+ /*
+ * No such thing, create a new one. name= matching without subsys
+ * specification is allowed for already existing hierarchies but we
+ * can't create new one without subsys specification.
+ */
+ if (!opts.subsys_mask && !opts.none) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ /* Hierarchies may only be created in the initial cgroup namespace. */
+ if (ns != &init_cgroup_ns) {
+ ret = -EPERM;
+ goto out_unlock;
+ }
+
+ root = kzalloc(sizeof(*root), GFP_KERNEL);
+ if (!root) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+
+ init_cgroup_root(root, &opts);
+
+ ret = cgroup_setup_root(root, opts.subsys_mask);
+ if (ret)
+ cgroup_free_root(root);
+
+out_unlock:
+ mutex_unlock(&cgroup_mutex);
+out_free:
+ kfree(opts.release_agent);
+ kfree(opts.name);
+
+ if (ret)
+ return ERR_PTR(ret);
+
+ dentry = cgroup_do_mount(&cgroup_fs_type, flags, root,
+ CGROUP_SUPER_MAGIC, ns);
+
+ /*
+ * If @pinned_sb, we're reusing an existing root and holding an
+ * extra ref on its sb. Mount is complete. Put the extra ref.
+ */
+ if (pinned_sb)
+ deactivate_super(pinned_sb);
+
+ return dentry;
+}
+
static int __init cgroup1_wq_init(void)
{
/*
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index f1b71fb..ae25f14 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -31,7 +31,6 @@
#include "cgroup-internal.h"
#include <linux/cred.h>
-#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/init_task.h>
#include <linux/kernel.h>
@@ -49,7 +48,6 @@
#include <linux/hashtable.h>
#include <linux/idr.h>
#include <linux/kthread.h>
-#include <linux/delay.h>
#include <linux/atomic.h>
#include <linux/cpuset.h>
#include <linux/proc_ns.h>
@@ -1080,7 +1078,7 @@ static void cgroup_exit_root_id(struct cgroup_root *root)
idr_remove(&cgroup_hierarchy_idr, root->hierarchy_id);
}
-static void cgroup_free_root(struct cgroup_root *root)
+void cgroup_free_root(struct cgroup_root *root)
{
if (root) {
idr_destroy(&root->cgroup_idr);
@@ -1234,7 +1232,6 @@ struct cgroup *task_cgroup_from_root(struct task_struct *task,
* update of a tasks cgroup pointer by cgroup_attach_task()
*/
-static struct kernfs_syscall_ops cgroup1_kf_syscall_ops;
static struct kernfs_syscall_ops cgroup_kf_syscall_ops;
static char *cgroup_file_name(struct cgroup *cgrp, const struct cftype *cft,
@@ -1542,8 +1539,8 @@ int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask)
return 0;
}
-static int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
- struct kernfs_root *kf_root)
+int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
+ struct kernfs_root *kf_root)
{
int len = 0;
char *buf = NULL;
@@ -1569,232 +1566,6 @@ static int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
return len;
}
-static int cgroup1_show_options(struct seq_file *seq, struct kernfs_root *kf_root)
-{
- struct cgroup_root *root = cgroup_root_from_kf(kf_root);
- struct cgroup_subsys *ss;
- int ssid;
-
- for_each_subsys(ss, ssid)
- if (root->subsys_mask & (1 << ssid))
- seq_show_option(seq, ss->legacy_name, NULL);
- if (root->flags & CGRP_ROOT_NOPREFIX)
- seq_puts(seq, ",noprefix");
- if (root->flags & CGRP_ROOT_XATTR)
- seq_puts(seq, ",xattr");
-
- spin_lock(&release_agent_path_lock);
- if (strlen(root->release_agent_path))
- seq_show_option(seq, "release_agent",
- root->release_agent_path);
- spin_unlock(&release_agent_path_lock);
-
- if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags))
- seq_puts(seq, ",clone_children");
- if (strlen(root->name))
- seq_show_option(seq, "name", root->name);
- return 0;
-}
-
-struct cgroup_sb_opts {
- u16 subsys_mask;
- unsigned int flags;
- char *release_agent;
- bool cpuset_clone_children;
- char *name;
- /* User explicitly requested empty subsystem */
- bool none;
-};
-
-static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
-{
- char *token, *o = data;
- bool all_ss = false, one_ss = false;
- u16 mask = U16_MAX;
- struct cgroup_subsys *ss;
- int nr_opts = 0;
- int i;
-
-#ifdef CONFIG_CPUSETS
- mask = ~((u16)1 << cpuset_cgrp_id);
-#endif
-
- memset(opts, 0, sizeof(*opts));
-
- while ((token = strsep(&o, ",")) != NULL) {
- nr_opts++;
-
- if (!*token)
- return -EINVAL;
- if (!strcmp(token, "none")) {
- /* Explicitly have no subsystems */
- opts->none = true;
- continue;
- }
- if (!strcmp(token, "all")) {
- /* Mutually exclusive option 'all' + subsystem name */
- if (one_ss)
- return -EINVAL;
- all_ss = true;
- continue;
- }
- if (!strcmp(token, "noprefix")) {
- opts->flags |= CGRP_ROOT_NOPREFIX;
- continue;
- }
- if (!strcmp(token, "clone_children")) {
- opts->cpuset_clone_children = true;
- continue;
- }
- if (!strcmp(token, "xattr")) {
- opts->flags |= CGRP_ROOT_XATTR;
- continue;
- }
- if (!strncmp(token, "release_agent=", 14)) {
- /* Specifying two release agents is forbidden */
- if (opts->release_agent)
- return -EINVAL;
- opts->release_agent =
- kstrndup(token + 14, PATH_MAX - 1, GFP_KERNEL);
- if (!opts->release_agent)
- return -ENOMEM;
- continue;
- }
- if (!strncmp(token, "name=", 5)) {
- const char *name = token + 5;
- /* Can't specify an empty name */
- if (!strlen(name))
- return -EINVAL;
- /* Must match [\w.-]+ */
- for (i = 0; i < strlen(name); i++) {
- char c = name[i];
- if (isalnum(c))
- continue;
- if ((c == '.') || (c == '-') || (c == '_'))
- continue;
- return -EINVAL;
- }
- /* Specifying two names is forbidden */
- if (opts->name)
- return -EINVAL;
- opts->name = kstrndup(name,
- MAX_CGROUP_ROOT_NAMELEN - 1,
- GFP_KERNEL);
- if (!opts->name)
- return -ENOMEM;
-
- continue;
- }
-
- for_each_subsys(ss, i) {
- if (strcmp(token, ss->legacy_name))
- continue;
- if (!cgroup_ssid_enabled(i))
- continue;
- if (cgroup_ssid_no_v1(i))
- continue;
-
- /* Mutually exclusive option 'all' + subsystem name */
- if (all_ss)
- return -EINVAL;
- opts->subsys_mask |= (1 << i);
- one_ss = true;
-
- break;
- }
- if (i == CGROUP_SUBSYS_COUNT)
- return -ENOENT;
- }
-
- /*
- * If the 'all' option was specified select all the subsystems,
- * otherwise if 'none', 'name=' and a subsystem name options were
- * not specified, let's default to 'all'
- */
- if (all_ss || (!one_ss && !opts->none && !opts->name))
- for_each_subsys(ss, i)
- if (cgroup_ssid_enabled(i) && !cgroup_ssid_no_v1(i))
- opts->subsys_mask |= (1 << i);
-
- /*
- * We either have to specify by name or by subsystems. (So all
- * empty hierarchies must have a name).
- */
- if (!opts->subsys_mask && !opts->name)
- return -EINVAL;
-
- /*
- * Option noprefix was introduced just for backward compatibility
- * with the old cpuset, so we allow noprefix only if mounting just
- * the cpuset subsystem.
- */
- if ((opts->flags & CGRP_ROOT_NOPREFIX) && (opts->subsys_mask & mask))
- return -EINVAL;
-
- /* Can't specify "none" and some subsystems */
- if (opts->subsys_mask && opts->none)
- return -EINVAL;
-
- return 0;
-}
-
-static int cgroup1_remount(struct kernfs_root *kf_root, int *flags, char *data)
-{
- int ret = 0;
- struct cgroup_root *root = cgroup_root_from_kf(kf_root);
- struct cgroup_sb_opts opts;
- u16 added_mask, removed_mask;
-
- cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
-
- /* See what subsystems are wanted */
- ret = parse_cgroupfs_options(data, &opts);
- if (ret)
- goto out_unlock;
-
- if (opts.subsys_mask != root->subsys_mask || opts.release_agent)
- pr_warn("option changes via remount are deprecated (pid=%d comm=%s)\n",
- task_tgid_nr(current), current->comm);
-
- added_mask = opts.subsys_mask & ~root->subsys_mask;
- removed_mask = root->subsys_mask & ~opts.subsys_mask;
-
- /* Don't allow flags or name to change at remount */
- if ((opts.flags ^ root->flags) ||
- (opts.name && strcmp(opts.name, root->name))) {
- pr_err("option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"\n",
- opts.flags, opts.name ?: "", root->flags, root->name);
- ret = -EINVAL;
- goto out_unlock;
- }
-
- /* remounting is not allowed for populated hierarchies */
- if (!list_empty(&root->cgrp.self.children)) {
- ret = -EBUSY;
- goto out_unlock;
- }
-
- ret = rebind_subsystems(root, added_mask);
- if (ret)
- goto out_unlock;
-
- WARN_ON(rebind_subsystems(&cgrp_dfl_root, removed_mask));
-
- if (opts.release_agent) {
- spin_lock(&release_agent_path_lock);
- strcpy(root->release_agent_path, opts.release_agent);
- spin_unlock(&release_agent_path_lock);
- }
-
- trace_cgroup_remount(root);
-
- out_unlock:
- kfree(opts.release_agent);
- kfree(opts.name);
- mutex_unlock(&cgroup_mutex);
- return ret;
-}
-
static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data)
{
pr_err("remount is not allowed\n");
@@ -1879,8 +1650,7 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp)
INIT_WORK(&cgrp->release_agent_work, cgroup_release_agent);
}
-static void init_cgroup_root(struct cgroup_root *root,
- struct cgroup_sb_opts *opts)
+void init_cgroup_root(struct cgroup_root *root, struct cgroup_sb_opts *opts)
{
struct cgroup *cgrp = &root->cgrp;
@@ -1899,7 +1669,7 @@ static void init_cgroup_root(struct cgroup_root *root,
set_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags);
}
-static int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
+int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
{
LIST_HEAD(tmp_links);
struct cgroup *root_cgrp = &root->cgrp;
@@ -1996,10 +1766,9 @@ static int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
return ret;
}
-static struct dentry *cgroup_do_mount(struct file_system_type *fs_type,
- int flags, struct cgroup_root *root,
- unsigned long magic,
- struct cgroup_namespace *ns)
+struct dentry *cgroup_do_mount(struct file_system_type *fs_type, int flags,
+ struct cgroup_root *root, unsigned long magic,
+ struct cgroup_namespace *ns)
{
struct dentry *dentry;
bool new_sb;
@@ -2033,155 +1802,6 @@ static struct dentry *cgroup_do_mount(struct file_system_type *fs_type,
return dentry;
}
-static struct dentry *cgroup1_mount(struct file_system_type *fs_type,
- int flags, void *data,
- unsigned long magic,
- struct cgroup_namespace *ns)
-{
- struct super_block *pinned_sb = NULL;
- struct cgroup_sb_opts opts;
- struct cgroup_root *root;
- struct cgroup_subsys *ss;
- struct dentry *dentry;
- int i, ret;
-
- cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
-
- /* First find the desired set of subsystems */
- ret = parse_cgroupfs_options(data, &opts);
- if (ret)
- goto out_unlock;
-
- /*
- * Destruction of cgroup root is asynchronous, so subsystems may
- * still be dying after the previous unmount. Let's drain the
- * dying subsystems. We just need to ensure that the ones
- * unmounted previously finish dying and don't care about new ones
- * starting. Testing ref liveliness is good enough.
- */
- for_each_subsys(ss, i) {
- if (!(opts.subsys_mask & (1 << i)) ||
- ss->root == &cgrp_dfl_root)
- continue;
-
- if (!percpu_ref_tryget_live(&ss->root->cgrp.self.refcnt)) {
- mutex_unlock(&cgroup_mutex);
- msleep(10);
- ret = restart_syscall();
- goto out_free;
- }
- cgroup_put(&ss->root->cgrp);
- }
-
- for_each_root(root) {
- bool name_match = false;
-
- if (root == &cgrp_dfl_root)
- continue;
-
- /*
- * If we asked for a name then it must match. Also, if
- * name matches but sybsys_mask doesn't, we should fail.
- * Remember whether name matched.
- */
- if (opts.name) {
- if (strcmp(opts.name, root->name))
- continue;
- name_match = true;
- }
-
- /*
- * If we asked for subsystems (or explicitly for no
- * subsystems) then they must match.
- */
- if ((opts.subsys_mask || opts.none) &&
- (opts.subsys_mask != root->subsys_mask)) {
- if (!name_match)
- continue;
- ret = -EBUSY;
- goto out_unlock;
- }
-
- if (root->flags ^ opts.flags)
- pr_warn("new mount options do not match the existing superblock, will be ignored\n");
-
- /*
- * We want to reuse @root whose lifetime is governed by its
- * ->cgrp. Let's check whether @root is alive and keep it
- * that way. As cgroup_kill_sb() can happen anytime, we
- * want to block it by pinning the sb so that @root doesn't
- * get killed before mount is complete.
- *
- * With the sb pinned, tryget_live can reliably indicate
- * whether @root can be reused. If it's being killed,
- * drain it. We can use wait_queue for the wait but this
- * path is super cold. Let's just sleep a bit and retry.
- */
- pinned_sb = kernfs_pin_sb(root->kf_root, NULL);
- if (IS_ERR(pinned_sb) ||
- !percpu_ref_tryget_live(&root->cgrp.self.refcnt)) {
- mutex_unlock(&cgroup_mutex);
- if (!IS_ERR_OR_NULL(pinned_sb))
- deactivate_super(pinned_sb);
- msleep(10);
- ret = restart_syscall();
- goto out_free;
- }
-
- ret = 0;
- goto out_unlock;
- }
-
- /*
- * No such thing, create a new one. name= matching without subsys
- * specification is allowed for already existing hierarchies but we
- * can't create new one without subsys specification.
- */
- if (!opts.subsys_mask && !opts.none) {
- ret = -EINVAL;
- goto out_unlock;
- }
-
- /* Hierarchies may only be created in the initial cgroup namespace. */
- if (ns != &init_cgroup_ns) {
- ret = -EPERM;
- goto out_unlock;
- }
-
- root = kzalloc(sizeof(*root), GFP_KERNEL);
- if (!root) {
- ret = -ENOMEM;
- goto out_unlock;
- }
-
- init_cgroup_root(root, &opts);
-
- ret = cgroup_setup_root(root, opts.subsys_mask);
- if (ret)
- cgroup_free_root(root);
-
-out_unlock:
- mutex_unlock(&cgroup_mutex);
-out_free:
- kfree(opts.release_agent);
- kfree(opts.name);
-
- if (ret)
- return ERR_PTR(ret);
-
- dentry = cgroup_do_mount(&cgroup_fs_type, flags, root,
- CGROUP_SUPER_MAGIC, ns);
-
- /*
- * If @pinned_sb, we're reusing an existing root and holding an
- * extra ref on its sb. Mount is complete. Put the extra ref.
- */
- if (pinned_sb)
- deactivate_super(pinned_sb);
-
- return dentry;
-}
-
static struct dentry *cgroup_mount(struct file_system_type *fs_type,
int flags, const char *unused_dev_name,
void *data)
@@ -4589,8 +4209,7 @@ static struct cgroup *cgroup_create(struct cgroup *parent)
return ERR_PTR(ret);
}
-static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
- umode_t mode)
+int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode)
{
struct cgroup *parent, *cgrp;
struct kernfs_node *kn;
@@ -4802,7 +4421,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
return 0;
};
-static int cgroup_rmdir(struct kernfs_node *kn)
+int cgroup_rmdir(struct kernfs_node *kn)
{
struct cgroup *cgrp;
int ret = 0;
@@ -4820,15 +4439,6 @@ static int cgroup_rmdir(struct kernfs_node *kn)
return ret;
}
-static struct kernfs_syscall_ops cgroup1_kf_syscall_ops = {
- .remount_fs = cgroup1_remount,
- .show_options = cgroup1_show_options,
- .rename = cgroup1_rename,
- .mkdir = cgroup_mkdir,
- .rmdir = cgroup_rmdir,
- .show_path = cgroup_show_path,
-};
-
static struct kernfs_syscall_ops cgroup_kf_syscall_ops = {
.remount_fs = cgroup_remount,
.mkdir = cgroup_mkdir,
--
2.9.3
--
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