The patch titled
cgroups: allow subsys to set default mode of its own file
has been removed from the -mm tree. Its filename was
cgroup-allow-subsys-to-set-default-mode-of-its-own-file.patch
This patch was dropped because an updated version will be merged
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: cgroups: allow subsys to set default mode of its own file
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
cgroup's subsys has "readonly" files, but default permission is always
rw-r--r--. This allows to create r--r--r-- file to subsys.
(The user can do chmod on this read-only file. But this behavior is not
different from current pseudo file systems as /proc.)
Reason:
When I wrote tools for maintaining cgroups, I couldn't find which file was
a writable interface via cgroup file systems. (finally, I did dirty
approach.)
IMHO, showing "this file is read-only" in explicit way is useful for
user-land (tools). In other story, a file whose name sounds read-only may
have "trigger" operation and support reseting. In this case, "writable"
is informative.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Acked-by: Li Zefan <lizf@xxxxxxxxxxxxx>
Acked-by: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
Cc: Paul Menage <menage@xxxxxxxxxx>
Cc: Dhaval Giani <dhaval@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/cgroup.h | 2 ++
kernel/cgroup.c | 5 ++++-
2 files changed, 6 insertions(+), 1 deletion(-)
diff -puN include/linux/cgroup.h~cgroup-allow-subsys-to-set-default-mode-of-its-own-file include/linux/cgroup.h
--- a/include/linux/cgroup.h~cgroup-allow-subsys-to-set-default-mode-of-its-own-file
+++ a/include/linux/cgroup.h
@@ -245,6 +245,8 @@ struct cftype {
* subsystem, followed by a period */
char name[MAX_CFTYPE_NAME];
int private;
+ /* if not 0, mode is set to mode, otherwise 0644 */
+ int mode;
/*
* If non-zero, defines the maximum length of string that can
diff -puN kernel/cgroup.c~cgroup-allow-subsys-to-set-default-mode-of-its-own-file kernel/cgroup.c
--- a/kernel/cgroup.c~cgroup-allow-subsys-to-set-default-mode-of-its-own-file
+++ a/kernel/cgroup.c
@@ -1706,7 +1706,10 @@ int cgroup_add_file(struct cgroup *cgrp,
BUG_ON(!mutex_is_locked(&dir->d_inode->i_mutex));
dentry = lookup_one_len(name, dir, strlen(name));
if (!IS_ERR(dentry)) {
- error = cgroup_create_file(dentry, 0644 | S_IFREG,
+ int mode = 0644;
+ if (cft->mode)
+ mode = cft->mode;
+ error = cgroup_create_file(dentry, mode | S_IFREG,
cgrp->root->sb);
if (!error)
dentry->d_fsdata = (void *)cft;
_
Patches currently in -mm which might be from kamezawa.hiroyu@xxxxxxxxxxxxxx are
linux-next.patch
proc-pid-maps-dont-show-pgoff-of-pure-anon-vmas.patch
proc-pid-maps-dont-show-pgoff-of-pure-anon-vmas-checkpatch-fixes.patch
mm-introduce-for_each_populated_zone-macro.patch
mm-introduce-for_each_populated_zone-macro-cleanup.patch
vmscan-respect-higher-order-in-zone_reclaim.patch
cgroup-allow-subsys-to-set-default-mode-of-its-own-file.patch
cgroup-memcg-show-correct-file-mode.patch
cgroup-css-id-support.patch
cgroup-fix-frequent-ebusy-at-rmdir.patch
cgroups-more-documentation-for-remount-and-release_agent.patch
memcg-use-css-id.patch
memcg-hierarchical-stat.patch
memcg-fix-shrinking-memory-to-return-ebusy-by-fixing-retry-algorithm.patch
memcg-fix-oom-killer-under-memcg.patch
memcg-fix-oom-killer-under-memcg-fix2.patch
memcg-fix-oom-killer-under-memcg-fix.patch
memcg-show-memcg-information-during-oom.patch
memcg-show-memcg-information-during-oom-fix2.patch
memcg-show-memcg-information-during-oom-fix.patch
memcg-show-memcg-information-during-oom-fix-fix.patch
memcg-show-memcg-information-during-oom-fix-fix-checkpatch-fixes.patch
memcg-remove-mem_cgroup_calc_mapped_ratio-take2.patch
memcg-remove-mem_cgroup_reclaim_imbalance-remnants.patch
use-css-id-in-swap_cgroup-for-saving-memory-v4.patch
cgroups-add-data-field-to-struct-cgroup_scanner.patch
cpuset-rewrite-update_tasks_nodemask.patch
cpuset-avoid-changing-cpusets-mems-when-errno-returned.patch
cpuset-remove-struct-cpuset_hotplug_scanner.patch
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