#define dummytop (&rootnode.top_cgroup)
/* This flag indicates whether tasks in the fork and exit paths should
- * take callback_mutex and check for fork/exit handlers to call. This
- * avoids us having to do extra work in the fork/exit path if none of the
- * subsystems need to be called.
+ * check for fork/exit handlers to call. This avoids us having to do
+ * extra work in the fork/exit path if none of the subsystems need to
+ * be called.
*/
static int need_forkexit_callback;
-/* bits in struct cgroup flags field */
-enum {
- /* Control Group is dead */
- CGRP_REMOVED,
- /* Control Group has previously had a child cgroup or a task,
- * but no longer (only if CGRP_NOTIFY_ON_RELEASE is set) */
- CGRP_RELEASABLE,
- /* Control Group requires release notifications to userspace */
- CGRP_NOTIFY_ON_RELEASE,
-};
-
/* convenient tests for these bits */
inline int cgroup_is_removed(const struct cgroup *cgrp)
{
* template: location in which to build the desired set of subsystem
* state objects for the new cgroup group
*/
-
static struct css_set *find_existing_css_set(
struct css_set *oldcg,
struct cgroup *cgrp,
/* Built the set of subsystem state objects that we want to
* see in the new css_set */
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
- if (root->subsys_bits & (1ull << i)) {
+ if (root->subsys_bits & (1UL << i)) {
/* Subsystem is in this hierarchy. So we want
* the subsystem state from the new
* cgroup */
* and chains them on tmp through their cgrp_link_list fields. Returns 0 on
* success or a negative error
*/
-
static int allocate_cg_links(int count, struct list_head *tmp)
{
struct cg_cgroup_link *link;
* substituted into the appropriate hierarchy. Must be called with
* cgroup_mutex held
*/
-
static struct css_set *find_css_set(
struct css_set *oldcg, struct cgroup *cgrp)
{
/* Link this cgroup group into the list */
list_add(&res->list, &init_css_set.list);
css_set_count++;
- INIT_LIST_HEAD(&res->tasks);
write_unlock(&css_set_lock);
return res;
* critical pieces of code here. The exception occurs on cgroup_exit(),
* when a task in a notify_on_release cgroup exits. Then cgroup_mutex
* is taken, and if the cgroup count is zero, a usermode call made
- * to /sbin/cgroup_release_agent with the name of the cgroup (path
- * relative to the root of cgroup file system) as the argument.
+ * to the release agent with the name of the cgroup (path relative to
+ * the root of cgroup file system) as the argument.
*
* A cgroup can only be deleted if both its 'count' of using tasks
* is zero, and its list of 'children' cgroups is empty. Since all
*
* The need for this exception arises from the action of
* cgroup_attach_task(), which overwrites one tasks cgroup pointer with
- * another. It does so using cgroup_mutexe, however there are
+ * another. It does so using cgroup_mutex, however there are
* several performance critical places that need to reference
* task->cgroup without the expense of grabbing a system global
* mutex. Therefore except as noted below, when dereferencing or, as
* cgroup_lock - lock out any changes to cgroup structures
*
*/
-
void cgroup_lock(void)
{
mutex_lock(&cgroup_mutex);
*
* Undo the lock taken in a previous cgroup_lock() call.
*/
-
void cgroup_unlock(void)
{
mutex_unlock(&cgroup_mutex);
* Call subsys's pre_destroy handler.
* This is called before css refcnt check.
*/
-
static void cgroup_call_pre_destroy(struct cgroup *cgrp)
{
struct cgroup_subsys *ss;
return;
}
-
static void cgroup_diput(struct dentry *dentry, struct inode *inode)
{
/* is dentry a directory ? if so, kfree() associated cgroup */
added_bits = final_bits & ~root->actual_subsys_bits;
/* Check that any added subsystems are currently free */
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
- unsigned long long bit = 1ull << i;
+ unsigned long bit = 1UL << i;
struct cgroup_subsys *ss = subsys[i];
if (!(bit & added_bits))
continue;
if (!*token)
return -EINVAL;
if (!strcmp(token, "all")) {
- opts->subsys_bits = (1 << CGROUP_SUBSYS_COUNT) - 1;
+ /* Add all non-disabled subsystems */
+ int i;
+ opts->subsys_bits = 0;
+ for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
+ struct cgroup_subsys *ss = subsys[i];
+ if (!ss->disabled)
+ opts->subsys_bits |= 1ul << i;
+ }
} else if (!strcmp(token, "noprefix")) {
set_bit(ROOT_NOPREFIX, &opts->flags);
} else if (!strncmp(token, "release_agent=", 14)) {
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
ss = subsys[i];
if (!strcmp(token, ss->name)) {
- set_bit(i, &opts->subsys_bits);
+ if (!ss->disabled)
+ set_bit(i, &opts->subsys_bits);
break;
}
}
if (!inode)
return -ENOMEM;
- inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
inode->i_op = &cgroup_dir_inode_operations;
/* directories start off with i_nlink == 2 (for "." entry) */
}
root = kzalloc(sizeof(*root), GFP_KERNEL);
- if (!root)
+ if (!root) {
+ if (opts.release_agent)
+ kfree(opts.release_agent);
return -ENOMEM;
+ }
init_cgroup_root(root);
root->subsys_bits = opts.subsys_bits;
return dentry->d_fsdata;
}
-/*
- * Called with cgroup_mutex held. Writes path of cgroup into buf.
+/**
+ * cgroup_path - generate the path of a cgroup
+ * @cgrp: the cgroup in question
+ * @buf: the buffer to write the path into
+ * @buflen: the length of the buffer
+ *
+ * Called with cgroup_mutex held. Writes path of cgroup into buf.
* Returns 0 on success, -errno on error.
*/
int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen)
*subsys_id = test_ss->subsys_id;
}
-/*
- * Attach task 'tsk' to cgroup 'cgrp'
+/**
+ * cgroup_attach_task - attach task 'tsk' to cgroup 'cgrp'
+ * @cgrp: the cgroup the task is attaching to
+ * @tsk: the task to be attached
*
- * Call holding cgroup_mutex. May take task_lock of
- * the task 'pid' during call.
+ * Call holding cgroup_mutex. May take task_lock of
+ * the task 'tsk' during call.
*/
int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
{
}
/* The various types of files and directories in a cgroup file system */
-
enum cgroup_filetype {
FILE_ROOT,
FILE_DIR,
FILE_TASKLIST,
FILE_NOTIFY_ON_RELEASE,
- FILE_RELEASABLE,
FILE_RELEASE_AGENT,
};
-static ssize_t cgroup_write_uint(struct cgroup *cgrp, struct cftype *cft,
- struct file *file,
- const char __user *userbuf,
- size_t nbytes, loff_t *unused_ppos)
+static ssize_t cgroup_write_X64(struct cgroup *cgrp, struct cftype *cft,
+ struct file *file,
+ const char __user *userbuf,
+ size_t nbytes, loff_t *unused_ppos)
{
char buffer[64];
int retval = 0;
- u64 val;
char *end;
if (!nbytes)
return -EFAULT;
buffer[nbytes] = 0; /* nul-terminate */
-
- /* strip newline if necessary */
- if (nbytes && (buffer[nbytes-1] == '\n'))
- buffer[nbytes-1] = 0;
- val = simple_strtoull(buffer, &end, 0);
- if (*end)
- return -EINVAL;
-
- /* Pass to subsystem */
- retval = cft->write_uint(cgrp, cft, val);
+ strstrip(buffer);
+ if (cft->write_u64) {
+ u64 val = simple_strtoull(buffer, &end, 0);
+ if (*end)
+ return -EINVAL;
+ retval = cft->write_u64(cgrp, cft, val);
+ } else {
+ s64 val = simple_strtoll(buffer, &end, 0);
+ if (*end)
+ return -EINVAL;
+ retval = cft->write_s64(cgrp, cft, val);
+ }
if (!retval)
retval = nbytes;
return retval;
return -ENODEV;
if (cft->write)
return cft->write(cgrp, cft, file, buf, nbytes, ppos);
- if (cft->write_uint)
- return cgroup_write_uint(cgrp, cft, file, buf, nbytes, ppos);
+ if (cft->write_u64 || cft->write_s64)
+ return cgroup_write_X64(cgrp, cft, file, buf, nbytes, ppos);
+ if (cft->trigger) {
+ int ret = cft->trigger(cgrp, (unsigned int)cft->private);
+ return ret ? ret : nbytes;
+ }
return -EINVAL;
}
-static ssize_t cgroup_read_uint(struct cgroup *cgrp, struct cftype *cft,
- struct file *file,
- char __user *buf, size_t nbytes,
- loff_t *ppos)
+static ssize_t cgroup_read_u64(struct cgroup *cgrp, struct cftype *cft,
+ struct file *file,
+ char __user *buf, size_t nbytes,
+ loff_t *ppos)
{
char tmp[64];
- u64 val = cft->read_uint(cgrp, cft);
+ u64 val = cft->read_u64(cgrp, cft);
int len = sprintf(tmp, "%llu\n", (unsigned long long) val);
return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
}
+static ssize_t cgroup_read_s64(struct cgroup *cgrp, struct cftype *cft,
+ struct file *file,
+ char __user *buf, size_t nbytes,
+ loff_t *ppos)
+{
+ char tmp[64];
+ s64 val = cft->read_s64(cgrp, cft);
+ int len = sprintf(tmp, "%lld\n", (long long) val);
+
+ return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
+}
+
static ssize_t cgroup_common_file_read(struct cgroup *cgrp,
struct cftype *cft,
struct file *file,
if (cft->read)
return cft->read(cgrp, cft, file, buf, nbytes, ppos);
- if (cft->read_uint)
- return cgroup_read_uint(cgrp, cft, file, buf, nbytes, ppos);
+ if (cft->read_u64)
+ return cgroup_read_u64(cgrp, cft, file, buf, nbytes, ppos);
+ if (cft->read_s64)
+ return cgroup_read_s64(cgrp, cft, file, buf, nbytes, ppos);
return -EINVAL;
}
+/*
+ * seqfile ops/methods for returning structured data. Currently just
+ * supports string->u64 maps, but can be extended in future.
+ */
+
+struct cgroup_seqfile_state {
+ struct cftype *cft;
+ struct cgroup *cgroup;
+};
+
+static int cgroup_map_add(struct cgroup_map_cb *cb, const char *key, u64 value)
+{
+ struct seq_file *sf = cb->state;
+ return seq_printf(sf, "%s %llu\n", key, (unsigned long long)value);
+}
+
+static int cgroup_seqfile_show(struct seq_file *m, void *arg)
+{
+ struct cgroup_seqfile_state *state = m->private;
+ struct cftype *cft = state->cft;
+ struct cgroup_map_cb cb = {
+ .fill = cgroup_map_add,
+ .state = m,
+ };
+ return cft->read_map(state->cgroup, cft, &cb);
+}
+
+int cgroup_seqfile_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq = file->private_data;
+ kfree(seq->private);
+ return single_release(inode, file);
+}
+
+static struct file_operations cgroup_seqfile_operations = {
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = cgroup_seqfile_release,
+};
+
static int cgroup_file_open(struct inode *inode, struct file *file)
{
int err;
cft = __d_cft(file->f_dentry);
if (!cft)
return -ENODEV;
- if (cft->open)
+ if (cft->read_map) {
+ struct cgroup_seqfile_state *state =
+ kzalloc(sizeof(*state), GFP_USER);
+ if (!state)
+ return -ENOMEM;
+ state->cft = cft;
+ state->cgroup = __d_cgrp(file->f_dentry->d_parent);
+ file->f_op = &cgroup_seqfile_operations;
+ err = single_open(file, cgroup_seqfile_show, state);
+ if (err < 0)
+ kfree(state);
+ } else if (cft->open)
err = cft->open(inode, file);
else
err = 0;
}
/*
- * cgroup_create_dir - create a directory for an object.
- * cgrp: the cgroup we create the directory for.
- * It must have a valid ->parent field
- * And we are going to fill its ->dentry field.
- * dentry: dentry of the new cgroup
- * mode: mode to set on new directory.
+ * cgroup_create_dir - create a directory for an object.
+ * @cgrp: the cgroup we create the directory for. It must have a valid
+ * ->parent field. And we are going to fill its ->dentry field.
+ * @dentry: dentry of the new cgroup
+ * @mode: mode to set on new directory.
*/
static int cgroup_create_dir(struct cgroup *cgrp, struct dentry *dentry,
int mode)
return 0;
}
-/* Count the number of tasks in a cgroup. */
-
+/**
+ * cgroup_task_count - count the number of tasks in a cgroup.
+ * @cgrp: the cgroup in question
+ *
+ * Return the number of tasks in the cgroup.
+ */
int cgroup_task_count(const struct cgroup *cgrp)
{
int count = 0;
* The tasklist_lock is not held here, as do_each_thread() and
* while_each_thread() are protected by RCU.
*/
-void cgroup_enable_task_cg_lists(void)
+static void cgroup_enable_task_cg_lists(void)
{
struct task_struct *p, *g;
write_lock(&css_set_lock);
use_task_css_set_links = 1;
do_each_thread(g, p) {
task_lock(p);
- if (list_empty(&p->cg_list))
+ /*
+ * We should check if the process is exiting, otherwise
+ * it will race with cgroup_exit() in that the list
+ * entry won't be deleted though the process has exited.
+ */
+ if (!(p->flags & PF_EXITING) && list_empty(&p->cg_list))
list_add(&p->cg_list, &p->cgroups->tasks);
task_unlock(p);
} while_each_thread(g, p);
if (heap->size) {
for (i = 0; i < heap->size; i++) {
- struct task_struct *p = heap->ptrs[i];
+ struct task_struct *q = heap->ptrs[i];
if (i == 0) {
- latest_time = p->start_time;
- latest_task = p;
+ latest_time = q->start_time;
+ latest_task = q;
}
/* Process the task per the caller's callback */
- scan->process_task(p, scan);
- put_task_struct(p);
+ scan->process_task(q, scan);
+ put_task_struct(q);
}
/*
* If we had to process any tasks at all, scan again
}
/**
- * Build and fill cgroupstats so that taskstats can export it to user
- * space.
- *
+ * cgroupstats_build - build and fill cgroupstats
* @stats: cgroupstats to fill information into
* @dentry: A dentry entry belonging to the cgroup for which stats have
* been requested.
+ *
+ * Build and fill cgroupstats so that taskstats can export it to user
+ * space.
*/
int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
{
kfree(pidarray);
} else {
- ctr->buf = 0;
+ ctr->buf = NULL;
ctr->bufsz = 0;
}
file->private_data = ctr;
return notify_on_release(cgrp);
}
-static u64 cgroup_read_releasable(struct cgroup *cgrp, struct cftype *cft)
-{
- return test_bit(CGRP_RELEASABLE, &cgrp->flags);
-}
-
/*
* for the common functions, 'private' gives the type of file
*/
{
.name = "notify_on_release",
- .read_uint = cgroup_read_notify_on_release,
+ .read_u64 = cgroup_read_notify_on_release,
.write = cgroup_common_file_write,
.private = FILE_NOTIFY_ON_RELEASE,
},
-
- {
- .name = "releasable",
- .read_uint = cgroup_read_releasable,
- .private = FILE_RELEASABLE,
- }
};
static struct cftype cft_release_agent = {
}
/*
- * cgroup_create - create a cgroup
- * parent: cgroup that will be parent of the new cgroup.
- * name: name of the new cgroup. Will be strcpy'ed.
- * mode: mode to set on new inode
+ * cgroup_create - create a cgroup
+ * @parent: cgroup that will be parent of the new cgroup
+ * @dentry: dentry of the new cgroup
+ * @mode: mode to set on new inode
*
- * Must be called with the mutex on the parent inode held
+ * Must be called with the mutex on the parent inode held
*/
-
static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
int mode)
{
mutex_lock(&cgroup_mutex);
- cgrp->flags = 0;
INIT_LIST_HEAD(&cgrp->sibling);
INIT_LIST_HEAD(&cgrp->children);
INIT_LIST_HEAD(&cgrp->css_sets);
cgrp->root = parent->root;
cgrp->top_cgroup = parent->top_cgroup;
+ if (notify_on_release(parent))
+ set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
+
for_each_subsys(root, ss) {
struct cgroup_subsys_state *css = ss->create(ss, cgrp);
if (IS_ERR(css)) {
parent = cgrp->parent;
root = cgrp->root;
sb = root->sb;
+
/*
- * Call pre_destroy handlers of subsys
+ * Call pre_destroy handlers of subsys. Notify subsystems
+ * that rmdir() request comes.
*/
cgroup_call_pre_destroy(cgrp);
- /*
- * Notify subsyses that rmdir() request comes.
- */
if (cgroup_has_css_refs(cgrp)) {
mutex_unlock(&cgroup_mutex);
return 0;
}
-static void cgroup_init_subsys(struct cgroup_subsys *ss)
+static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
{
struct cgroup_subsys_state *css;
struct list_head *l;
}
/**
- * cgroup_init_early - initialize cgroups at system boot, and
- * initialize any subsystems that request early init.
+ * cgroup_init_early - cgroup initialization at system boot
+ *
+ * Initialize cgroups at system boot, and initialize any
+ * subsystems that request early init.
*/
int __init cgroup_init_early(void)
{
}
/**
- * cgroup_init - register cgroup filesystem and /proc file, and
- * initialize any subsystems that didn't request early init.
+ * cgroup_init - cgroup initialization
+ *
+ * Register cgroup filesystem and /proc file, and initialize
+ * any subsystems that didn't request early init.
*/
int __init cgroup_init(void)
{
int err;
int i;
- struct proc_dir_entry *entry;
err = bdi_init(&cgroup_backing_dev_info);
if (err)
if (err < 0)
goto out;
- entry = create_proc_entry("cgroups", 0, NULL);
- if (entry)
- entry->proc_fops = &proc_cgroupstats_operations;
+ proc_create("cgroups", 0, NULL, &proc_cgroupstats_operations);
out:
if (err)
/* Skip this hierarchy if it has no active subsystems */
if (!root->actual_subsys_bits)
continue;
+ seq_printf(m, "%lu:", root->subsys_bits);
for_each_subsys(root, ss)
seq_printf(m, "%s%s", count++ ? "," : "", ss->name);
seq_putc(m, ':');
{
int i;
- seq_puts(m, "#subsys_name\thierarchy\tnum_cgroups\n");
+ seq_puts(m, "#subsys_name\thierarchy\tnum_cgroups\tenabled\n");
mutex_lock(&cgroup_mutex);
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
struct cgroup_subsys *ss = subsys[i];
- seq_printf(m, "%s\t%lu\t%d\n",
+ seq_printf(m, "%s\t%lu\t%d\t%d\n",
ss->name, ss->root->subsys_bits,
- ss->root->number_of_cgroups);
+ ss->root->number_of_cgroups, !ss->disabled);
}
mutex_unlock(&cgroup_mutex);
return 0;
static int cgroupstats_open(struct inode *inode, struct file *file)
{
- return single_open(file, proc_cgroupstats_show, 0);
+ return single_open(file, proc_cgroupstats_show, NULL);
}
static struct file_operations proc_cgroupstats_operations = {
/**
* cgroup_fork - attach newly forked task to its parents cgroup.
- * @tsk: pointer to task_struct of forking parent process.
+ * @child: pointer to task_struct of forking parent process.
*
* Description: A task inherits its parent's cgroup at fork().
*
}
/**
- * cgroup_fork_callbacks - called on a new task very soon before
- * adding it to the tasklist. No need to take any locks since no-one
- * can be operating on this task
+ * cgroup_fork_callbacks - run fork callbacks
+ * @child: the new task
+ *
+ * Called on a new task very soon before adding it to the
+ * tasklist. No need to take any locks since no-one can
+ * be operating on this task.
*/
void cgroup_fork_callbacks(struct task_struct *child)
{
}
/**
- * cgroup_post_fork - called on a new task after adding it to the
- * task list. Adds the task to the list running through its css_set
- * if necessary. Has to be after the task is visible on the task list
- * in case we race with the first call to cgroup_iter_start() - to
- * guarantee that the new task ends up on its list. */
+ * cgroup_post_fork - called on a new task after adding it to the task list
+ * @child: the task in question
+ *
+ * Adds the task to the list running through its css_set if necessary.
+ * Has to be after the task is visible on the task list in case we race
+ * with the first call to cgroup_iter_start() - to guarantee that the
+ * new task ends up on its list.
+ */
void cgroup_post_fork(struct task_struct *child)
{
if (use_task_css_set_links) {
/**
* cgroup_exit - detach cgroup from exiting task
* @tsk: pointer to task_struct of exiting process
+ * @run_callback: run exit callbacks?
*
* Description: Detach cgroup from @tsk and release it.
*
* top_cgroup isn't going away, and either task has PF_EXITING set,
* which wards off any cgroup_attach_task() attempts, or task is a failed
* fork, never visible to cgroup_attach_task.
- *
*/
void cgroup_exit(struct task_struct *tsk, int run_callbacks)
{
}
/**
- * cgroup_clone - duplicate the current cgroup in the hierarchy
- * that the given subsystem is attached to, and move this task into
- * the new child
+ * cgroup_clone - clone the cgroup the given subsystem is attached to
+ * @tsk: the task to be moved
+ * @subsys: the given subsystem
+ *
+ * Duplicate the current cgroup in the hierarchy that the given
+ * subsystem is attached to, and move this task into the new
+ * child.
*/
int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys)
{
return ret;
}
-/*
- * See if "cgrp" is a descendant of the current task's cgroup in
- * the appropriate hierarchy
+/**
+ * cgroup_is_descendant - see if @cgrp is a descendant of current task's cgrp
+ * @cgrp: the cgroup in question
+ *
+ * See if @cgrp is a descendant of the current task's cgroup in
+ * the appropriate hierarchy.
*
* If we are sending in dummytop, then presumably we are creating
* the top cgroup in the subsystem.
* release agent task. We don't bother to wait because the caller of
* this routine has no use for the exit status of the release agent
* task, so no sense holding our caller up for that.
- *
*/
-
static void cgroup_release_agent(struct work_struct *work)
{
BUG_ON(work != &release_agent_work);
spin_unlock(&release_list_lock);
mutex_unlock(&cgroup_mutex);
}
+
+static int __init cgroup_disable(char *str)
+{
+ int i;
+ char *token;
+
+ while ((token = strsep(&str, ",")) != NULL) {
+ if (!*token)
+ continue;
+
+ for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
+ struct cgroup_subsys *ss = subsys[i];
+
+ if (!strcmp(token, ss->name)) {
+ ss->disabled = 1;
+ printk(KERN_INFO "Disabling %s control group"
+ " subsystem\n", ss->name);
+ break;
+ }
+ }
+ }
+ return 1;
+}
+__setup("cgroup_disable=", cgroup_disable);
projects / linux-2.6 / blobdiff