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| author | Pavel Emelyanov <xemul@openvz.org> | 2008-06-06 09:46:26 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-06-06 22:29:11 +0400 |
| commit | cc9cb219aac24ffc711566c8f372c2b3a3bf840f (patch) | |
| tree | efa678227596922a00b2a7744c33707041c78316 /security/device_cgroup.c | |
| parent | b66862f7663332aa1ecb3ebda4086360ddb8befc (diff) | |
| download | linux-cc9cb219aac24ffc711566c8f372c2b3a3bf840f.tar.xz | |
devscgroup: relax task to dev_cgroup conversion
Two functions, that need to get a device_cgroup from a task (they are
devcgroup_inode_permission and devcgroup_inode_mknod) make it in a strange
way:
They get a css_set from task, then a subsys_state from css_set, then a
cgroup from the state and then a subsys_state again from the cgroup.
Besides, the devices_subsys_id is read from memory, whilst there's a
enum-ed constant for it.
Optimize this part a bit:
1. Get the subsys_stats form the task and be done - no 2 extra
dereferences,
2. Use the device_subsys_id constant, not the value from memory
(i.e. one less dereference).
Found while preparing 2.6.26 OpenVZ port.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'security/device_cgroup.c')
| -rw-r--r-- | security/device_cgroup.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/security/device_cgroup.c b/security/device_cgroup.c index 15f2f8003ba3..f9941a769738 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -506,7 +506,6 @@ struct cgroup_subsys devices_subsys = { int devcgroup_inode_permission(struct inode *inode, int mask) { - struct cgroup *cgroup; struct dev_cgroup *dev_cgroup; struct dev_whitelist_item *wh; @@ -515,8 +514,8 @@ int devcgroup_inode_permission(struct inode *inode, int mask) return 0; if (!S_ISBLK(inode->i_mode) && !S_ISCHR(inode->i_mode)) return 0; - cgroup = task_cgroup(current, devices_subsys.subsys_id); - dev_cgroup = cgroup_to_devcgroup(cgroup); + dev_cgroup = css_to_devcgroup(task_subsys_state(current, + devices_subsys_id)); if (!dev_cgroup) return 0; @@ -547,12 +546,11 @@ acc_check: int devcgroup_inode_mknod(int mode, dev_t dev) { - struct cgroup *cgroup; struct dev_cgroup *dev_cgroup; struct dev_whitelist_item *wh; - cgroup = task_cgroup(current, devices_subsys.subsys_id); - dev_cgroup = cgroup_to_devcgroup(cgroup); + dev_cgroup = css_to_devcgroup(task_subsys_state(current, + devices_subsys_id)); if (!dev_cgroup) return 0; |