[PATCH v3 27/28] css_set_fork(): switch to CLASS(fd_raw, ...)

Al Viro
2024-11-02T05:08:32Z

reference acquired there by fget_raw() is not stashed anywhere -
we could as well borrow instead.

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
kernel/cgroup/cgroup.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 8305a67ea8d9..02acc2540c46 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -6476,7 +6476,6 @@ static int cgroup_css_set_fork(struct kernel_clone_args *kargs)
struct cgroup *dst_cgrp = NULL;
struct css_set *cset;
struct super_block *sb;
- struct file *f;

if (kargs->flags & CLONE_INTO_CGROUP)
cgroup_lock();
@@ -6493,14 +6492,14 @@ static int cgroup_css_set_fork(struct kernel_clone_args *kargs)
return 0;
}

- f = fget_raw(kargs->cgroup);
- if (!f) {
+ CLASS(fd_raw, f)(kargs->cgroup);
+ if (fd_empty(f)) {
ret = -EBADF;
goto err;
}
- sb = f->f_path.dentry->d_sb;
+ sb = fd_file(f)->f_path.dentry->d_sb;

- dst_cgrp = cgroup_get_from_file(f);
+ dst_cgrp = cgroup_get_from_file(fd_file(f));
if (IS_ERR(dst_cgrp)) {
ret = PTR_ERR(dst_cgrp);
dst_cgrp = NULL;
@@ -6548,15 +6547,12 @@ static int cgroup_css_set_fork(struct kernel_clone_args *kargs)
}

put_css_set(cset);
- fput(f);
kargs->cgrp = dst_cgrp;
return ret;

err:
cgroup_threadgroup_change_end(current);
cgroup_unlock();
- if (f)
- fput(f);
if (dst_cgrp)
cgroup_put(dst_cgrp);
put_css_set(cset);
--
2.39.5