[PATCH 1/2] cgroup: Check for ret during cgroup1_base_files cft addition

[PATCH 1/2] cgroup: Check for ret during cgroup1_base_files cft addition

[Kamalesh Babulal]

There is no check for possible failure while populating
cgroup1_base_files cft in css_populate_dir(), like its cgroup v2 counter
parts cgroup_{base,psi}_files.  In case of failure, the cgroup might not
be set up right.  Add ret value check to return on failure.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
---
 kernel/cgroup/cgroup.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 1fb7f562289d..a6b1ea324b0e 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1731,8 +1731,10 @@ static int css_populate_dir(struct cgroup_subsys_state *css)
 					return ret;
 			}
 		} else {
-			cgroup_addrm_files(css, cgrp,
-					   cgroup1_base_files, true);
+			ret  =  cgroup_addrm_files(css, cgrp,
+						   cgroup1_base_files, true);
+			if  (ret  < 0)
+				return ret;
 		}
 	} else {
 		list_for_each_entry(cfts, &css->ss->cfts, node) {

base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d
-- 
2.41.0

[PATCH 2/2] cgroup: Avoid extra dereference in css_populate_dir()

[Kamalesh Babulal]

Use css directly instead of dereferencing it from &cgroup->self, while
adding the cgroup v2 cft base and psi files in css_populate_dir(). Both
points to the same css, when css->ss is NULL, this avoids extra deferences
and makes code consistent in usage across the function.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
---
 kernel/cgroup/cgroup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index a6b1ea324b0e..f8ff85033e5a 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1719,13 +1719,13 @@ static int css_populate_dir(struct cgroup_subsys_state *css)
 
 	if (!css->ss) {
 		if (cgroup_on_dfl(cgrp)) {
-			ret = cgroup_addrm_files(&cgrp->self, cgrp,
+			ret = cgroup_addrm_files(css, cgrp,
 						 cgroup_base_files, true);
 			if (ret < 0)
 				return ret;
 
 			if (cgroup_psi_enabled()) {
-				ret = cgroup_addrm_files(&cgrp->self, cgrp,
+				ret = cgroup_addrm_files(css, cgrp,
 							 cgroup_psi_files, true);
 				if (ret < 0)
 					return ret;
-- 
2.41.0

Re: [PATCH 1/2] cgroup: Check for ret during cgroup1_base_files cft addition

[Tejun Heo]

On Tue, Sep 12, 2023 at 12:34:34PM +0530, Kamalesh Babulal wrote:
> There is no check for possible failure while populating
> cgroup1_base_files cft in css_populate_dir(), like its cgroup v2 counter
> parts cgroup_{base,psi}_files.  In case of failure, the cgroup might not
> be set up right.  Add ret value check to return on failure.
> 
> Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>

Applied to cgroup/for-6.7 with double spaces removed.

Thanks.

-- 
tejun

Re: [PATCH 2/2] cgroup: Avoid extra dereference in css_populate_dir()

[Tejun Heo]

On Tue, Sep 12, 2023 at 12:34:35PM +0530, Kamalesh Babulal wrote:
> Use css directly instead of dereferencing it from &cgroup->self, while
> adding the cgroup v2 cft base and psi files in css_populate_dir(). Both
> points to the same css, when css->ss is NULL, this avoids extra deferences
> and makes code consistent in usage across the function.
> 
> Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>

Applied to cgroup/for-6.7.

Thanks.

-- 
tejun