cgroup/bfq: revert bfq.weight symlink change

There's some discussion on how to do this the best, and Tejun prefers
that BFQ just create the file itself instead of having cgroups support
a symlink feature.

Hence revert commit 54b7b868e826 and 19e9da9e86c4 for 5.2, and this
can be done properly for 5.3.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 4 insertions, 29 deletions

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 155048b0eca2..426a0026225c 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1460,8 +1460,8 @@ struct cgroup *task_cgroup_from_root(struct task_struct *task,
 
 static struct kernfs_syscall_ops cgroup_kf_syscall_ops;
 
-static char *cgroup_fill_name(struct cgroup *cgrp, const struct cftype *cft,
-			      char *buf, bool write_link_name)
+static char *cgroup_file_name(struct cgroup *cgrp, const struct cftype *cft,
+			      char *buf)
 {
 	struct cgroup_subsys *ss = cft->ss;
 
@@ -1471,26 +1471,13 @@ static char *cgroup_fill_name(struct cgroup *cgrp, const struct cftype *cft,
 
 		snprintf(buf, CGROUP_FILE_NAME_MAX, "%s%s.%s",
 			 dbg, cgroup_on_dfl(cgrp) ? ss->name : ss->legacy_name,
-			 write_link_name ? cft->link_name : cft->name);
+			 cft->name);
 	} else {
-		strscpy(buf, write_link_name ? cft->link_name : cft->name,
-			CGROUP_FILE_NAME_MAX);
+		strscpy(buf, cft->name, CGROUP_FILE_NAME_MAX);
 	}
 	return buf;
 }
 
-static char *cgroup_file_name(struct cgroup *cgrp, const struct cftype *cft,
-			      char *buf)
-{
-	return cgroup_fill_name(cgrp, cft, buf, false);
-}
-
-static char *cgroup_link_name(struct cgroup *cgrp, const struct cftype *cft,
-			      char *buf)
-{
-	return cgroup_fill_name(cgrp, cft, buf, true);
-}
-
 /**
  * cgroup_file_mode - deduce file mode of a control file
  * @cft: the control file in question
@@ -1649,9 +1636,6 @@ static void cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft)
 	}
 
 	kernfs_remove_by_name(cgrp->kn, cgroup_file_name(cgrp, cft, name));
-	if (cft->flags & CFTYPE_SYMLINKED)
-		kernfs_remove_by_name(cgrp->kn,
-				      cgroup_link_name(cgrp, cft, name));
 }
 
 /**
@@ -3837,7 +3821,6 @@ static int cgroup_add_file(struct cgroup_subsys_state *css, struct cgroup *cgrp,
 {
 	char name[CGROUP_FILE_NAME_MAX];
 	struct kernfs_node *kn;
-	struct kernfs_node *kn_link;
 	struct lock_class_key *key = NULL;
 	int ret;
 
@@ -3868,14 +3851,6 @@ static int cgroup_add_file(struct cgroup_subsys_state *css, struct cgroup *cgrp,
 		spin_unlock_irq(&cgroup_file_kn_lock);
 	}
 
-	if (cft->flags & CFTYPE_SYMLINKED) {
-		kn_link = kernfs_create_link(cgrp->kn,
-					     cgroup_link_name(cgrp, cft, name),
-					     kn);
-		if (IS_ERR(kn_link))
-			return PTR_ERR(kn_link);
-	}
-
 	return 0;
 }