struct blkcg_policy_data *cpd;
cpd = pol->cpd_alloc_fn(GFP_KERNEL);
- if (!cpd) {
- mutex_unlock(&blkcg_pol_mutex);
+ if (!cpd)
goto err_free_cpds;
- }
blkcg->cpd[pol->plid] = cpd;
cpd->blkcg = blkcg;
* kn_to: /n1/n2/n3 [depth=3]
* result: /../..
*
- * return value: length of the string. If greater than buflen,
- * then contents of buf are undefined. On error, -1 is returned.
+ * Returns the length of the full path. If the full length is equal to or
+ * greater than @buflen, @buf contains the truncated path with the trailing
+ * '\0'. On error, -errno is returned.
*/
static int kernfs_path_from_node_locked(struct kernfs_node *kn_to,
struct kernfs_node *kn_from,
{
struct kernfs_node *kn, *common;
const char parent_str[] = "/..";
- size_t depth_from, depth_to, len = 0, nlen = 0;
- char *p;
- int i;
+ size_t depth_from, depth_to, len = 0;
+ int i, j;
if (!kn_from)
kn_from = kernfs_root(kn_to)->kn;
common = kernfs_common_ancestor(kn_from, kn_to);
if (WARN_ON(!common))
- return -1;
+ return -EINVAL;
depth_to = kernfs_depth(common, kn_to);
depth_from = kernfs_depth(common, kn_from);
len < buflen ? buflen - len : 0);
/* Calculate how many bytes we need for the rest */
- for (kn = kn_to; kn != common; kn = kn->parent)
- nlen += strlen(kn->name) + 1;
-
- if (len + nlen >= buflen)
- return len + nlen;
-
- p = buf + len + nlen;
- *p = '\0';
- for (kn = kn_to; kn != common; kn = kn->parent) {
- size_t tmp = strlen(kn->name);
- p -= tmp;
- memcpy(p, kn->name, tmp);
- *(--p) = '/';
+ for (i = depth_to - 1; i >= 0; i--) {
+ for (kn = kn_to, j = 0; j < i; j++)
+ kn = kn->parent;
+ len += strlcpy(buf + len, "/",
+ len < buflen ? buflen - len : 0);
+ len += strlcpy(buf + len, kn->name,
+ len < buflen ? buflen - len : 0);
}
- return len + nlen;
+ return len;
}
/**
return ret;
}
-/**
- * kernfs_path_len - determine the length of the full path of a given node
- * @kn: kernfs_node of interest
- *
- * The returned length doesn't include the space for the terminating '\0'.
- */
-size_t kernfs_path_len(struct kernfs_node *kn)
-{
- size_t len = 0;
- unsigned long flags;
-
- spin_lock_irqsave(&kernfs_rename_lock, flags);
-
- do {
- len += strlen(kn->name) + 1;
- kn = kn->parent;
- } while (kn && kn->parent);
-
- spin_unlock_irqrestore(&kernfs_rename_lock, flags);
-
- return len;
-}
-
/**
* kernfs_path_from_node - build path of node @to relative to @from.
* @from: parent kernfs_node relative to which we need to build the path
* path (which includes '..'s) as needed to reach from @from to @to is
* returned.
*
- * If @buf isn't long enough, the return value will be greater than @buflen
- * and @buf contents are undefined.
+ * Returns the length of the full path. If the full length is equal to or
+ * greater than @buflen, @buf contains the truncated path with the trailing
+ * '\0'. On error, -errno is returned.
*/
int kernfs_path_from_node(struct kernfs_node *to, struct kernfs_node *from,
char *buf, size_t buflen)
}
EXPORT_SYMBOL_GPL(kernfs_path_from_node);
-/**
- * kernfs_path - build full path of a given node
- * @kn: kernfs_node of interest
- * @buf: buffer to copy @kn's name into
- * @buflen: size of @buf
- *
- * Builds and returns the full path of @kn in @buf of @buflen bytes. The
- * path is built from the end of @buf so the returned pointer usually
- * doesn't match @buf. If @buf isn't long enough, @buf is nul terminated
- * and %NULL is returned.
- */
-char *kernfs_path(struct kernfs_node *kn, char *buf, size_t buflen)
-{
- int ret;
-
- ret = kernfs_path_from_node(kn, NULL, buf, buflen);
- if (ret < 0 || ret >= buflen)
- return NULL;
- return buf;
-}
-EXPORT_SYMBOL_GPL(kernfs_path);
-
/**
* pr_cont_kernfs_name - pr_cont name of a kernfs_node
* @kn: kernfs_node of interest
void sysfs_warn_dup(struct kernfs_node *parent, const char *name)
{
- char *buf, *path = NULL;
+ char *buf;
buf = kzalloc(PATH_MAX, GFP_KERNEL);
if (buf)
- path = kernfs_path(parent, buf, PATH_MAX);
+ kernfs_path(parent, buf, PATH_MAX);
WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s/%s'\n",
- path, name);
+ buf, name);
kfree(buf);
}
*/
static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen)
{
- char *p;
-
- p = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
- if (!p) {
- strncpy(buf, "<unavailable>", buflen);
- return -ENAMETOOLONG;
- }
-
- memmove(buf, p, buf + buflen - p);
- return 0;
+ return cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
}
/**
int cgroup_rm_cftypes(struct cftype *cfts);
void cgroup_file_notify(struct cgroup_file *cfile);
-char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen);
+int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen);
int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry);
int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *tsk);
return kernfs_name(cgrp->kn, buf, buflen);
}
-static inline char * __must_check cgroup_path(struct cgroup *cgrp, char *buf,
- size_t buflen)
+static inline int cgroup_path(struct cgroup *cgrp, char *buf, size_t buflen)
{
return kernfs_path(cgrp->kn, buf, buflen);
}
struct user_namespace *user_ns,
struct cgroup_namespace *old_ns);
-char *cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
- struct cgroup_namespace *ns);
+int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
+ struct cgroup_namespace *ns);
#else /* !CONFIG_CGROUPS */
}
int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen);
-size_t kernfs_path_len(struct kernfs_node *kn);
int kernfs_path_from_node(struct kernfs_node *root_kn, struct kernfs_node *kn,
char *buf, size_t buflen);
-char *kernfs_path(struct kernfs_node *kn, char *buf, size_t buflen);
void pr_cont_kernfs_name(struct kernfs_node *kn);
void pr_cont_kernfs_path(struct kernfs_node *kn);
struct kernfs_node *kernfs_get_parent(struct kernfs_node *kn);
static inline int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen)
{ return -ENOSYS; }
-static inline size_t kernfs_path_len(struct kernfs_node *kn)
-{ return 0; }
-
-static inline char *kernfs_path(struct kernfs_node *kn, char *buf,
- size_t buflen)
-{ return NULL; }
+static inline int kernfs_path_from_node(struct kernfs_node *root_kn,
+ struct kernfs_node *kn,
+ char *buf, size_t buflen)
+{ return -ENOSYS; }
static inline void pr_cont_kernfs_name(struct kernfs_node *kn) { }
static inline void pr_cont_kernfs_path(struct kernfs_node *kn) { }
#endif /* CONFIG_KERNFS */
+/**
+ * kernfs_path - build full path of a given node
+ * @kn: kernfs_node of interest
+ * @buf: buffer to copy @kn's name into
+ * @buflen: size of @buf
+ *
+ * Builds and returns the full path of @kn in @buf of @buflen bytes. The
+ * path is built from the end of @buf so the returned pointer usually
+ * doesn't match @buf. If @buf isn't long enough, @buf is nul terminated
+ * and %NULL is returned.
+ */
+static inline int kernfs_path(struct kernfs_node *kn, char *buf, size_t buflen)
+{
+ return kernfs_path_from_node(kn, NULL, buf, buflen);
+}
+
static inline struct kernfs_node *
kernfs_find_and_get(struct kernfs_node *kn, const char *name)
{
--- /dev/null
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM cgroup
+
+#if !defined(_TRACE_CGROUP_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_CGROUP_H
+
+#include <linux/cgroup.h>
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(cgroup_root,
+
+ TP_PROTO(struct cgroup_root *root),
+
+ TP_ARGS(root),
+
+ TP_STRUCT__entry(
+ __field( int, root )
+ __field( u16, ss_mask )
+ __string( name, root->name )
+ ),
+
+ TP_fast_assign(
+ __entry->root = root->hierarchy_id;
+ __entry->ss_mask = root->subsys_mask;
+ __assign_str(name, root->name);
+ ),
+
+ TP_printk("root=%d ss_mask=%#x name=%s",
+ __entry->root, __entry->ss_mask, __get_str(name))
+);
+
+DEFINE_EVENT(cgroup_root, cgroup_setup_root,
+
+ TP_PROTO(struct cgroup_root *root),
+
+ TP_ARGS(root)
+);
+
+DEFINE_EVENT(cgroup_root, cgroup_destroy_root,
+
+ TP_PROTO(struct cgroup_root *root),
+
+ TP_ARGS(root)
+);
+
+DEFINE_EVENT(cgroup_root, cgroup_remount,
+
+ TP_PROTO(struct cgroup_root *root),
+
+ TP_ARGS(root)
+);
+
+DECLARE_EVENT_CLASS(cgroup,
+
+ TP_PROTO(struct cgroup *cgrp),
+
+ TP_ARGS(cgrp),
+
+ TP_STRUCT__entry(
+ __field( int, root )
+ __field( int, id )
+ __field( int, level )
+ __dynamic_array(char, path,
+ cgrp->kn ? cgroup_path(cgrp, NULL, 0) + 1
+ : strlen("(null)"))
+ ),
+
+ TP_fast_assign(
+ __entry->root = cgrp->root->hierarchy_id;
+ __entry->id = cgrp->id;
+ __entry->level = cgrp->level;
+ if (cgrp->kn)
+ cgroup_path(cgrp, __get_dynamic_array(path),
+ __get_dynamic_array_len(path));
+ else
+ __assign_str(path, "(null)");
+ ),
+
+ TP_printk("root=%d id=%d level=%d path=%s",
+ __entry->root, __entry->id, __entry->level, __get_str(path))
+);
+
+DEFINE_EVENT(cgroup, cgroup_mkdir,
+
+ TP_PROTO(struct cgroup *cgroup),
+
+ TP_ARGS(cgroup)
+);
+
+DEFINE_EVENT(cgroup, cgroup_rmdir,
+
+ TP_PROTO(struct cgroup *cgroup),
+
+ TP_ARGS(cgroup)
+);
+
+DEFINE_EVENT(cgroup, cgroup_release,
+
+ TP_PROTO(struct cgroup *cgroup),
+
+ TP_ARGS(cgroup)
+);
+
+DEFINE_EVENT(cgroup, cgroup_rename,
+
+ TP_PROTO(struct cgroup *cgroup),
+
+ TP_ARGS(cgroup)
+);
+
+DECLARE_EVENT_CLASS(cgroup_migrate,
+
+ TP_PROTO(struct cgroup *dst_cgrp, struct task_struct *task, bool threadgroup),
+
+ TP_ARGS(dst_cgrp, task, threadgroup),
+
+ TP_STRUCT__entry(
+ __field( int, dst_root )
+ __field( int, dst_id )
+ __field( int, dst_level )
+ __dynamic_array(char, dst_path,
+ dst_cgrp->kn ? cgroup_path(dst_cgrp, NULL, 0) + 1
+ : strlen("(null)"))
+ __field( int, pid )
+ __string( comm, task->comm )
+ ),
+
+ TP_fast_assign(
+ __entry->dst_root = dst_cgrp->root->hierarchy_id;
+ __entry->dst_id = dst_cgrp->id;
+ __entry->dst_level = dst_cgrp->level;
+ if (dst_cgrp->kn)
+ cgroup_path(dst_cgrp, __get_dynamic_array(dst_path),
+ __get_dynamic_array_len(dst_path));
+ else
+ __assign_str(dst_path, "(null)");
+ __entry->pid = task->pid;
+ __assign_str(comm, task->comm);
+ ),
+
+ TP_printk("dst_root=%d dst_id=%d dst_level=%d dst_path=%s pid=%d comm=%s",
+ __entry->dst_root, __entry->dst_id, __entry->dst_level,
+ __get_str(dst_path), __entry->pid, __get_str(comm))
+);
+
+DEFINE_EVENT(cgroup_migrate, cgroup_attach_task,
+
+ TP_PROTO(struct cgroup *dst_cgrp, struct task_struct *task, bool threadgroup),
+
+ TP_ARGS(dst_cgrp, task, threadgroup)
+);
+
+DEFINE_EVENT(cgroup_migrate, cgroup_transfer_tasks,
+
+ TP_PROTO(struct cgroup *dst_cgrp, struct task_struct *task, bool threadgroup),
+
+ TP_ARGS(dst_cgrp, task, threadgroup)
+);
+
+#endif /* _TRACE_CGROUP_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
#include <linux/file.h>
#include <net/sock.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/cgroup.h>
+
/*
* pidlists linger the following amount before being destroyed. The goal
* is avoiding frequent destruction in the middle of consecutive read calls
struct cgroup *cgrp = &root->cgrp;
struct cgrp_cset_link *link, *tmp_link;
+ trace_cgroup_destroy_root(root);
+
cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
BUG_ON(atomic_read(&root->nr_cgrps));
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);
if (ret)
goto destroy_root;
+ trace_cgroup_setup_root(root);
+
/*
* There must be no failure case after here, since rebinding takes
* care of subsystems' refcounts, which are explicitly dropped in
.fs_flags = FS_USERNS_MOUNT,
};
-static char *cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen,
- struct cgroup_namespace *ns)
+static int cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen,
+ struct cgroup_namespace *ns)
{
struct cgroup *root = cset_cgroup_from_root(ns->root_cset, cgrp->root);
- int ret;
- ret = kernfs_path_from_node(cgrp->kn, root->kn, buf, buflen);
- if (ret < 0 || ret >= buflen)
- return NULL;
- return buf;
+ return kernfs_path_from_node(cgrp->kn, root->kn, buf, buflen);
}
-char *cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
- struct cgroup_namespace *ns)
+int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
+ struct cgroup_namespace *ns)
{
- char *ret;
+ int ret;
mutex_lock(&cgroup_mutex);
spin_lock_irq(&css_set_lock);
*
* Return value is the same as kernfs_path().
*/
-char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
+int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
{
struct cgroup_root *root;
struct cgroup *cgrp;
int hierarchy_id = 1;
- char *path = NULL;
+ int ret;
mutex_lock(&cgroup_mutex);
spin_lock_irq(&css_set_lock);
if (root) {
cgrp = task_cgroup_from_root(task, root);
- path = cgroup_path_ns_locked(cgrp, buf, buflen, &init_cgroup_ns);
+ ret = cgroup_path_ns_locked(cgrp, buf, buflen, &init_cgroup_ns);
} else {
/* if no hierarchy exists, everyone is in "/" */
- if (strlcpy(buf, "/", buflen) < buflen)
- path = buf;
+ ret = strlcpy(buf, "/", buflen);
}
spin_unlock_irq(&css_set_lock);
mutex_unlock(&cgroup_mutex);
- return path;
+ return ret;
}
EXPORT_SYMBOL_GPL(task_cgroup_path);
ret = cgroup_migrate(leader, threadgroup, dst_cgrp->root);
cgroup_migrate_finish(&preloaded_csets);
+
+ if (!ret)
+ trace_cgroup_attach_task(dst_cgrp, leader, threadgroup);
+
return ret;
}
mutex_lock(&cgroup_mutex);
ret = kernfs_rename(kn, new_parent, new_name_str);
+ if (!ret)
+ trace_cgroup_rename(cgrp);
mutex_unlock(&cgroup_mutex);
if (task) {
ret = cgroup_migrate(task, false, to->root);
+ if (!ret)
+ trace_cgroup_transfer_tasks(to, task, false);
put_task_struct(task);
}
} while (task && !ret);
ss->css_released(css);
} else {
/* cgroup release path */
+ trace_cgroup_release(cgrp);
+
cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id);
cgrp->id = -1;
if (ret)
goto out_destroy;
+ trace_cgroup_mkdir(cgrp);
+
/* let's create and online css's */
kernfs_activate(kn);
ret = cgroup_destroy_locked(cgrp);
+ if (!ret)
+ trace_cgroup_rmdir(cgrp);
+
cgroup_kn_unlock(kn);
return ret;
}
int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *tsk)
{
- char *buf, *path;
+ char *buf;
int retval;
struct cgroup_root *root;
* " (deleted)" is appended to the cgroup path.
*/
if (cgroup_on_dfl(cgrp) || !(tsk->flags & PF_EXITING)) {
- path = cgroup_path_ns_locked(cgrp, buf, PATH_MAX,
+ retval = cgroup_path_ns_locked(cgrp, buf, PATH_MAX,
current->nsproxy->cgroup_ns);
- if (!path) {
+ if (retval >= PATH_MAX)
retval = -ENAMETOOLONG;
+ if (retval < 0)
goto out_unlock;
- }
+
+ seq_puts(m, buf);
} else {
- path = "/";
+ seq_puts(m, "/");
}
- seq_puts(m, path);
-
if (cgroup_on_dfl(cgrp) && cgroup_is_dead(cgrp))
seq_puts(m, " (deleted)\n");
else
{
struct cgroup *cgrp =
container_of(work, struct cgroup, release_agent_work);
- char *pathbuf = NULL, *agentbuf = NULL, *path;
+ char *pathbuf = NULL, *agentbuf = NULL;
char *argv[3], *envp[3];
+ int ret;
mutex_lock(&cgroup_mutex);
goto out;
spin_lock_irq(&css_set_lock);
- path = cgroup_path_ns_locked(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns);
+ ret = cgroup_path_ns_locked(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns);
spin_unlock_irq(&css_set_lock);
- if (!path)
+ if (ret < 0 || ret >= PATH_MAX)
goto out;
argv[0] = agentbuf;
- argv[1] = path;
+ argv[1] = pathbuf;
argv[2] = NULL;
/* minimal command environment */
int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *tsk)
{
- char *buf, *p;
+ char *buf;
struct cgroup_subsys_state *css;
int retval;
if (!buf)
goto out;
- retval = -ENAMETOOLONG;
css = task_get_css(tsk, cpuset_cgrp_id);
- p = cgroup_path_ns(css->cgroup, buf, PATH_MAX,
- current->nsproxy->cgroup_ns);
+ retval = cgroup_path_ns(css->cgroup, buf, PATH_MAX,
+ current->nsproxy->cgroup_ns);
css_put(css);
- if (!p)
+ if (retval >= PATH_MAX)
+ retval = -ENAMETOOLONG;
+ if (retval < 0)
goto out_free;
- seq_puts(m, p);
+ seq_puts(m, buf);
seq_putc(m, '\n');
retval = 0;
out_free:
if (autogroup_path(tg, group_path, PATH_MAX))
return group_path;
- return cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
+ cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
+ return group_path;
}
#endif
projects / cascardo / linux.git / commitdiff