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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-23 15:48:35 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-23 15:48:35 -0700 |
commit | c2468d32f5a57298b732826af84cdc39745d179c (patch) | |
tree | adcb5668dbe43a173002f23107e3df8d2a1be396 /kernel | |
parent | 549f3a1218ba18fcde11ef0e22b07e6365645788 (diff) | |
parent | 913ffdb54366f94eec65c656cae8c6e00e1ab1b0 (diff) | |
download | linux-stable-c2468d32f5a57298b732826af84cdc39745d179c.tar.gz linux-stable-c2468d32f5a57298b732826af84cdc39745d179c.tar.bz2 linux-stable-c2468d32f5a57298b732826af84cdc39745d179c.zip |
Merge branch 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup changes from Tejun Heo:
"This contains two patches, both of which aren't fixes per-se but I
think it'd be better to fast-track them.
One removes bcache_subsys_id which was added without proper review
through the block tree. Fortunately, bcache cgroup code is
unconditionally disabled, so this was never exposed to userland. The
cgroup subsys_id is removed. Kent will remove the affected (disabled)
code through bcache branch.
The other simplifies task_group_path_from_hierarchy(). The function
doesn't currently have in-kernel users but there are external code and
development going on dependent on the function and making the function
available for 3.11 would make things go smoother"
* 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: replace task_cgroup_path_from_hierarchy() with task_cgroup_path()
cgroup: remove bcache_subsys_id which got added stealthily
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/cgroup.c | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 0e0b20b8c5db..789ec4683db3 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1845,36 +1845,43 @@ out: EXPORT_SYMBOL_GPL(cgroup_path); /** - * task_cgroup_path_from_hierarchy - cgroup path of a task on a hierarchy + * task_cgroup_path - cgroup path of a task in the first cgroup hierarchy * @task: target task - * @hierarchy_id: the hierarchy to look up @task's cgroup from * @buf: the buffer to write the path into * @buflen: the length of the buffer * - * Determine @task's cgroup on the hierarchy specified by @hierarchy_id and - * copy its path into @buf. This function grabs cgroup_mutex and shouldn't - * be used inside locks used by cgroup controller callbacks. + * Determine @task's cgroup on the first (the one with the lowest non-zero + * hierarchy_id) cgroup hierarchy and copy its path into @buf. This + * function grabs cgroup_mutex and shouldn't be used inside locks used by + * cgroup controller callbacks. + * + * Returns 0 on success, fails with -%ENAMETOOLONG if @buflen is too short. */ -int task_cgroup_path_from_hierarchy(struct task_struct *task, int hierarchy_id, - char *buf, size_t buflen) +int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen) { struct cgroupfs_root *root; - struct cgroup *cgrp = NULL; - int ret = -ENOENT; + struct cgroup *cgrp; + int hierarchy_id = 1, ret = 0; + + if (buflen < 2) + return -ENAMETOOLONG; mutex_lock(&cgroup_mutex); - root = idr_find(&cgroup_hierarchy_idr, hierarchy_id); + root = idr_get_next(&cgroup_hierarchy_idr, &hierarchy_id); + if (root) { cgrp = task_cgroup_from_root(task, root); ret = cgroup_path(cgrp, buf, buflen); + } else { + /* if no hierarchy exists, everyone is in "/" */ + memcpy(buf, "/", 2); } mutex_unlock(&cgroup_mutex); - return ret; } -EXPORT_SYMBOL_GPL(task_cgroup_path_from_hierarchy); +EXPORT_SYMBOL_GPL(task_cgroup_path); /* * Control Group taskset |