[PATCH 11/12] Add members file support to RGCS

Chandra Seetharaman
2006-04-28T01:37:56Z

11/12 - user_interface_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>

rgcs.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 49 insertions(+)

Index: linux-2617-rc3/kernel/res_group/rgcs.c
===================================================================
--- linux-2617-rc3.orig/kernel/res_group/rgcs.c 2006-04-27 10:18:47.000000000 -0700
+++ linux-2617-rc3/kernel/res_group/rgcs.c 2006-04-27 10:18:47.000000000 -0700
@@ -242,6 +242,43 @@ static ssize_t show_shares(struct resour
return rc;
}

+/*
+ * Given a buffer with a pid in it, add the task with that pid to the
+ * resource group. Ignores entire buffer after the first pid is parsed.
+ */
+static int add_member(struct resource_group *rgroup, const char *str)
+{
+ pid_t pid;
+
+ pid = (pid_t) simple_strtol(str, NULL, 0);
+ if (pid <= 0)
+ return -EINVAL; /* Not a valid pid */
+ return set_res_group(pid, rgroup);
+}
+
+/*
+ * Lists pids of tasks that belong to the given rgroup.
+ */
+static ssize_t show_members(struct resource_group *rgroup, char *buf)
+{
+ ssize_t i, rc = 0, bufsize = PAGE_SIZE;
+ struct task_struct *tsk;
+
+ spin_lock(&rgroup->group_lock);
+ list_for_each_entry(tsk, &rgroup->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(&rgroup->group_lock);
+ return rc;
+}
+
struct rgroup_attribute {
struct configfs_attribute configfs_attr;
ssize_t (*show)(struct resource_group *, char *);
@@ -268,6 +305,17 @@ struct rgroup_attribute shares_attr = {
.store = set_shares
};

+struct rgroup_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 rgcs_subsys;
static struct config_item_type rgcs_item_type;

@@ -417,6 +465,7 @@ static struct configfs_group_operations
static struct configfs_attribute *rgroup_attrs[] = {
&stats_attr.configfs_attr,
&shares_attr.configfs_attr,
+ &members_attr.configfs_attr,
NULL