Commit f34d3606 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 

Pull cgroup updates from Tejun Heo:

 - tracepoints for basic cgroup management operations added

 - kernfs and cgroup path formatting functions updated to behave in the
   style of strlcpy()

 - non-critical bug fixes

* 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  blkcg: Unlock blkcg_pol_mutex only once when cpd == NULL
  cgroup: fix error handling regressions in proc_cgroup_show() and cgroup_release_agent()
  cpuset: fix error handling regression in proc_cpuset_show()
  cgroup: add tracepoints for basic operations
  cgroup: make cgroup_path() and friends behave in the style of strlcpy()
  kernfs: remove kernfs_path_len()
  kernfs: make kernfs_path*() behave in the style of strlcpy()
  kernfs: add dummy implementation of kernfs_path_from_node()
parents b6daa51b bbb427e3

block/blk-cgroup.c

+1 −3
Original line number Diff line number Diff line
@@ -1340,10 +1340,8 @@ int blkcg_policy_register(struct blkcg_policy *pol) 
			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;

fs/kernfs/dir.c

+17 −67
Original line number Diff line number Diff line
@@ -110,8 +110,9 @@ static struct kernfs_node *kernfs_common_ancestor(struct kernfs_node *a, 
 * 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,
@@ -119,9 +120,8 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to, 
{

	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;
@@ -131,7 +131,7 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to, 


	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);
@@ -144,22 +144,16 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to, 
			       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;

}



/**
@@ -185,29 +179,6 @@ int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen) 
	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
@@ -220,8 +191,9 @@ size_t kernfs_path_len(struct kernfs_node *kn) 
 * 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)
@@ -236,28 +208,6 @@ int kernfs_path_from_node(struct kernfs_node *to, struct kernfs_node *from, 
}

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

fs/sysfs/dir.c

+3 −3
Original line number Diff line number Diff line
@@ -21,14 +21,14 @@ DEFINE_SPINLOCK(sysfs_symlink_target_lock); 


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);

}

include/linux/blk-cgroup.h

+1 −10
Original line number Diff line number Diff line
@@ -343,16 +343,7 @@ static inline struct blkcg *cpd_to_blkcg(struct blkcg_policy_data *cpd) 
 */

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);

}



/**

include/linux/cgroup.h

+4 −5
Original line number Diff line number Diff line
@@ -97,7 +97,7 @@ int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); 
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);
@@ -555,8 +555,7 @@ static inline int cgroup_name(struct cgroup *cgrp, char *buf, size_t buflen) 
	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);

}
@@ -658,7 +657,7 @@ struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, 
					struct user_namespace *user_ns,

					struct cgroup_namespace *old_ns);



char *cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,

int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,

		   struct cgroup_namespace *ns);



#else /* !CONFIG_CGROUPS */

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