On Sun, Jan 12, 2014 at 11:58 PM, S.Çağlar Onur <cag...@10ur.org> wrote:
> Hey there,
>
> On Sun, Jan 12, 2014 at 7:24 PM, Stéphane Graber <stgra...@ubuntu.com> wrote:
>> On Sat, Jan 11, 2014 at 12:14:26AM -0600, Serge Hallyn wrote:
>>> Currently when a container is shut down, lxc walks the set of all
>>> cgroup paths it created, in reverse order, and tries to remove them.
>>> This doesn't suffice if the container has also created new cgroups.
>>>
>>> It'd be impolite to recursively remove all the cgroup paths we created,
>>> since this can include '/lxc' and thereunder all other containers
>>> started since.
>>>
>>> This patch changes container shutdown to only delete the container's own
>>> path, but do so recursively. Note that if we fail during startup,
>>> the container won't have created any cgroup paths so it the old
>>> way works fine.
>>>
>>> Signed-off-by: Serge Hallyn <serge.hal...@ubuntu.com>
>>
>> Acked-by: Stéphane Graber <stgra...@ubuntu.com>
>
> This patch started to cause my add_remove_device_node tests to fail
> (rmdir started to return EBUSY), following seems to solve it but I'm
> not sure whether it's a fix or just a workaround. Any ideas what might
> be triggering that?
Converted my go test to C API and sent to list as I thought having a
test for that won't hurt. On the other hand, I'll be waiting your
answer to submit the other patch that ignores the EBUSY.
> diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
> index 48fef74..80e68fb 100644
> --- a/src/lxc/lxccontainer.c
> +++ b/src/lxc/lxccontainer.c
> @@ -2934,7 +2934,7 @@ static bool add_remove_device_node(struct
> lxc_container *c, const char *src_path
> ERROR("unlink failed");
> goto out;
> }
> - if (rmdir(directory_path) < 0 && errno != ENOTEMPTY) {
> + if (rmdir(directory_path) < 0 && errno != ENOTEMPTY &&
> errno != EBUSY) {
> ERROR("rmdir failed");
> goto out;
> }
>
>
>>> ---
>>> src/lxc/cgroup.c | 101
>>> ++++++++++++++++++++++++++++++++++++++++++++++++-------
>>> 1 file changed, 88 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/src/lxc/cgroup.c b/src/lxc/cgroup.c
>>> index b1196b4..be43c73 100644
>>> --- a/src/lxc/cgroup.c
>>> +++ b/src/lxc/cgroup.c
>>> @@ -68,9 +68,9 @@ static char **subsystems_from_mount_options(const char
>>> *mount_options, char **ke
>>> static void lxc_cgroup_mount_point_free(struct cgroup_mount_point *mp);
>>> static void lxc_cgroup_hierarchy_free(struct cgroup_hierarchy *h);
>>> static bool is_valid_cgroup(const char *name);
>>> -static int create_or_remove_cgroup(bool remove, struct cgroup_mount_point
>>> *mp, const char *path);
>>> +static int create_or_remove_cgroup(bool remove, struct cgroup_mount_point
>>> *mp, const char *path, int recurse);
>>> static int create_cgroup(struct cgroup_mount_point *mp, const char *path);
>>> -static int remove_cgroup(struct cgroup_mount_point *mp, const char *path);
>>> +static int remove_cgroup(struct cgroup_mount_point *mp, const char *path,
>>> bool recurse);
>>> static char *cgroup_to_absolute_path(struct cgroup_mount_point *mp, const
>>> char *path, const char *suffix);
>>> static struct cgroup_process_info *find_info_for_subsystem(struct
>>> cgroup_process_info *info, const char *subsystem);
>>> static int do_cgroup_get(const char *cgroup_path, const char
>>> *sub_filename, char *value, size_t len);
>>> @@ -81,6 +81,75 @@ static int cgroup_recursive_task_count(const char
>>> *cgroup_path);
>>> static int count_lines(const char *fn);
>>> static int handle_cgroup_settings(struct cgroup_mount_point *mp, char
>>> *cgroup_path);
>>>
>>> +static int cgroup_rmdir(char *dirname)
>>> +{
>>> + struct dirent dirent, *direntp;
>>> + int saved_errno = 0;
>>> + DIR *dir;
>>> + int ret, failed=0;
>>> + char pathname[MAXPATHLEN];
>>> +
>>> + dir = opendir(dirname);
>>> + if (!dir) {
>>> + ERROR("%s: failed to open %s", __func__, dirname);
>>> + return -1;
>>> + }
>>> +
>>> + while (!readdir_r(dir, &dirent, &direntp)) {
>>> + struct stat mystat;
>>> + int rc;
>>> +
>>> + if (!direntp)
>>> + break;
>>> +
>>> + if (!strcmp(direntp->d_name, ".") ||
>>> + !strcmp(direntp->d_name, ".."))
>>> + continue;
>>> +
>>> + rc = snprintf(pathname, MAXPATHLEN, "%s/%s", dirname,
>>> direntp->d_name);
>>> + if (rc < 0 || rc >= MAXPATHLEN) {
>>> + ERROR("pathname too long");
>>> + failed=1;
>>> + if (!saved_errno)
>>> + saved_errno = -ENOMEM;
>>> + continue;
>>> + }
>>> + ret = lstat(pathname, &mystat);
>>> + if (ret) {
>>> + SYSERROR("%s: failed to stat %s", __func__, pathname);
>>> + failed=1;
>>> + if (!saved_errno)
>>> + saved_errno = errno;
>>> + continue;
>>> + }
>>> + if (S_ISDIR(mystat.st_mode)) {
>>> + if (cgroup_rmdir(pathname) < 0) {
>>> + if (!saved_errno)
>>> + saved_errno = errno;
>>> + failed=1;
>>> + }
>>> + }
>>> + }
>>> +
>>> + if (rmdir(dirname) < 0) {
>>> + SYSERROR("%s: failed to delete %s", __func__, dirname);
>>> + if (!saved_errno)
>>> + saved_errno = errno;
>>> + failed=1;
>>> + }
>>> +
>>> + ret = closedir(dir);
>>> + if (ret) {
>>> + SYSERROR("%s: failed to close directory %s", __func__,
>>> dirname);
>>> + if (!saved_errno)
>>> + saved_errno = errno;
>>> + failed=1;
>>> + }
>>> +
>>> + errno = saved_errno;
>>> + return failed ? -1 : 0;
>>> +}
>>> +
>>> struct cgroup_meta_data *lxc_cgroup_load_meta()
>>> {
>>> const char *cgroup_use = NULL;
>>> @@ -745,7 +814,7 @@ extern struct cgroup_process_info
>>> *lxc_cgroup_create(const char *name, const cha
>>> * In that case, remove the cgroup from all previous
>>> hierarchies
>>> */
>>> for (j = 0, info_ptr = base_info; j < i && info_ptr; info_ptr
>>> = info_ptr->next, j++) {
>>> - r = remove_cgroup(info_ptr->designated_mount_point,
>>> info_ptr->created_paths[info_ptr->created_paths_count - 1]);
>>> + r = remove_cgroup(info_ptr->designated_mount_point,
>>> info_ptr->created_paths[info_ptr->created_paths_count - 1], false);
>>> if (r < 0)
>>> WARN("could not clean up cgroup we created
>>> when trying to create container");
>>>
>>> free(info_ptr->created_paths[info_ptr->created_paths_count - 1]);
>>> @@ -1039,8 +1108,7 @@ void lxc_cgroup_process_info_free_and_remove(struct
>>> cgroup_process_info *info)
>>> if (!info)
>>> return;
>>> next = info->next;
>>> - for (pp = info->created_paths; pp && *pp; pp++);
>>> - for ((void)(pp && --pp); info->created_paths && pp >=
>>> info->created_paths; --pp) {
>>> + {
>>> struct cgroup_mount_point *mp = info->designated_mount_point;
>>> if (!mp)
>>> mp = lxc_cgroup_find_mount_point(info->hierarchy,
>>> info->cgroup_path, true);
>>> @@ -1049,7 +1117,10 @@ void lxc_cgroup_process_info_free_and_remove(struct
>>> cgroup_process_info *info)
>>> * '/lxc' cgroup in this container but another
>>> container
>>> * is still running (for example)
>>> */
>>> - (void)remove_cgroup(mp, *pp);
>>> + (void)remove_cgroup(mp, info->cgroup_path, true);
>>> + }
>>> + for (pp = info->created_paths; pp && *pp; pp++);
>>> + for ((void)(pp && --pp); info->created_paths && pp >=
>>> info->created_paths; --pp) {
>>> free(*pp);
>>> }
>>> free(info->created_paths);
>>> @@ -1609,7 +1680,7 @@ bool is_valid_cgroup(const char *name)
>>> return strcmp(name, ".") != 0 && strcmp(name, "..") != 0;
>>> }
>>>
>>> -int create_or_remove_cgroup(bool do_remove, struct cgroup_mount_point *mp,
>>> const char *path)
>>> +int create_or_remove_cgroup(bool do_remove, struct cgroup_mount_point *mp,
>>> const char *path, int recurse)
>>> {
>>> int r, saved_errno = 0;
>>> char *buf = cgroup_to_absolute_path(mp, path, NULL);
>>> @@ -1617,9 +1688,13 @@ int create_or_remove_cgroup(bool do_remove, struct
>>> cgroup_mount_point *mp, const
>>> return -1;
>>>
>>> /* create or remove directory */
>>> - r = do_remove ?
>>> - rmdir(buf) :
>>> - mkdir(buf, 0777);
>>> + if (do_remove) {
>>> + if (recurse)
>>> + r = cgroup_rmdir(buf);
>>> + else
>>> + r = rmdir(buf);
>>> + } else
>>> + r = mkdir(buf, 0777);
>>> saved_errno = errno;
>>> free(buf);
>>> errno = saved_errno;
>>> @@ -1628,12 +1703,12 @@ int create_or_remove_cgroup(bool do_remove, struct
>>> cgroup_mount_point *mp, const
>>>
>>> int create_cgroup(struct cgroup_mount_point *mp, const char *path)
>>> {
>>> - return create_or_remove_cgroup(false, mp, path);
>>> + return create_or_remove_cgroup(false, mp, path, false);
>>> }
>>>
>>> -int remove_cgroup(struct cgroup_mount_point *mp, const char *path)
>>> +int remove_cgroup(struct cgroup_mount_point *mp, const char *path, bool
>>> recurse)
>>> {
>>> - return create_or_remove_cgroup(true, mp, path);
>>> + return create_or_remove_cgroup(true, mp, path, recurse);
>>> }
>>>
>>> char *cgroup_to_absolute_path(struct cgroup_mount_point *mp, const char
>>> *path, const char *suffix)
>>> --
>>> 1.8.5.2
>>>
>>> _______________________________________________
>>> lxc-devel mailing list
>>> lxc-devel@lists.linuxcontainers.org
>>> http://lists.linuxcontainers.org/listinfo/lxc-devel
>>
>> --
>> Stéphane Graber
>> Ubuntu developer
>> http://www.ubuntu.com
>>
>> _______________________________________________
>> lxc-devel mailing list
>> lxc-devel@lists.linuxcontainers.org
>> http://lists.linuxcontainers.org/listinfo/lxc-devel
>>
>
>
>
> --
> S.Çağlar Onur <cag...@10ur.org>
--
S.Çağlar Onur <cag...@10ur.org>
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