cgroup: move v1 mount functions to kernel/cgroup/cgroup-v1.c
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@kernel.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
This commit is contained in:
Tejun Heo
parent
fa069904dd
commit
1592c9b223
|
|
@ -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 mutex cgroup_mutex;
|
||||
extern spinlock_t css_set_lock;
|
||||
extern struct cgroup_subsys *cgroup_subsys[];
|
||||
|
|
@ -66,7 +76,13 @@ 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);
|
||||
|
|
@ -86,18 +102,24 @@ 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 */
|
||||
|
|
|
|||
|
|
@ -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)
|
||||
{
|
||||
|
|
@ -800,7 +802,7 @@ out_free:
|
|||
/*
|
||||
* cgroup_rename - Only allow simple rename of directories in place.
|
||||
*/
|
||||
int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
|
||||
static int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
|
||||
const char *new_name_str)
|
||||
{
|
||||
struct cgroup *cgrp = kn->priv;
|
||||
|
|
@ -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)
|
||||
{
|
||||
/*
|
||||
|
|
|
|||
|
|
@ -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>
|
||||
|
|
@ -1078,7 +1076,7 @@ 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);
|
||||
|
|
@ -1232,7 +1230,6 @@ 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,
|
||||
|
|
@ -1540,7 +1537,7 @@ 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,
|
||||
int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
|
||||
struct kernfs_root *kf_root)
|
||||
{
|
||||
int len = 0;
|
||||
|
|
@ -1567,232 +1564,6 @@ 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");
|
||||
|
|
@ -1877,8 +1648,7 @@ 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;
|
||||
|
||||
|
|
@ -1897,7 +1667,7 @@ 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;
|
||||
|
|
@ -1994,9 +1764,8 @@ out:
|
|||
return ret;
|
||||
}
|
||||
|
||||
static struct dentry *cgroup_do_mount(struct file_system_type *fs_type,
|
||||
int flags, struct cgroup_root *root,
|
||||
unsigned long magic,
|
||||
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;
|
||||
|
|
@ -2031,155 +1800,6 @@ 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)
|
||||
|
|
@ -4587,8 +4207,7 @@ out_destroy:
|
|||
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;
|
||||
|
|
@ -4800,7 +4419,7 @@ 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;
|
||||
|
|
@ -4818,15 +4437,6 @@ 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,
|
||||
|
|
|
|||
Loading…
Reference in New Issue