[RFC] [PATCH 11/12] Add members file support to RCFS

sekharan
2006-04-21T02:27:58Z

11/12 - ckrm_configfs_rcfs_members

Adds attr_store and attr_show support for members file.
--

Signed-Off-By: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-Off-By: Shailabh Nagar <nagar@watson.ibm.com>
Signed-Off-By: Matt Helsley <matthltc@us.ibm.com>

kernel/ckrm/ckrm_rcfs.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 49 insertions(+)

Index: linux2617-rc2/kernel/ckrm/ckrm_rcfs.c
===================================================================
--- linux2617-rc2.orig/kernel/ckrm/ckrm_rcfs.c
+++ linux2617-rc2/kernel/ckrm/ckrm_rcfs.c
@@ -244,6 +244,43 @@ static ssize_t show_shares(struct ckrm_c
return rc;
}

+/*
+ * Given a buffer with a pid in it, add the task with that pid to the class.
+ * Ignores entire buffer after the first pid is parsed.
+ */
+static int add_member(struct ckrm_class *class, const char *str)
+{
+ pid_t pid;
+
+ pid = (pid_t) simple_strtol(str, NULL, 0);
+ if (pid <= 0)
+ return -EINVAL; /* Not a valid pid */
+ return ckrm_setclass(pid, class);
+}
+
+/*
+ * Lists pids of tasks that belong to the given class.
+ */
+static ssize_t show_members(struct ckrm_class *class, char *buf)
+{
+ ssize_t i, rc = 0, bufsize = PAGE_SIZE;
+ struct task_struct *tsk;
+
+ spin_lock(&class->class_lock);
+ list_for_each_entry(tsk, &class->task_list, member_list) {
+ if (bufsize <= 0) {
+ rc = -ENOSPC;
+ break;
+ }
+ if (!tsk->pid) /* Ignore swappers */
+ continue;
+ i = snprintf(buf, bufsize, "%ld\n", (long)tsk->pid);
+ buf += i; rc += i; bufsize -= i;
+ }
+ spin_unlock(&class->class_lock);
+ return rc;
+}
+
struct class_attribute {
struct configfs_attribute configfs_attr;
ssize_t (*show)(struct ckrm_class *, char *);
@@ -270,6 +307,17 @@ struct class_attribute shares_attr = {
.store = set_shares
};

+struct class_attribute members_attr = {
+ .configfs_attr = {
+ .ca_name = "members",
+ .ca_owner = THIS_MODULE,
+ .ca_mode = S_IRUGO | S_IWUSR
+ },
+ .show = show_members,
+ .store = add_member
+};
+
+
static struct configfs_subsystem rcfs_subsys;
static struct config_item_type rcfs_class_type;

@@ -415,6 +463,7 @@ static struct configfs_group_operations
static struct configfs_attribute *class_attrs[] = {
&stats_attr.configfs_attr,
&shares_attr.configfs_attr,
+ &members_attr.configfs_attr,
NULL
};