From: Olaf Kirch <[email protected]>
Subject: Add register_sysctl_table_path function
There are a number of modules that register a sysctl table
somewhere deeply nested in the sysctl hierarchy, such as
fs/nfs, fs/xfs, dev/cdrom, etc.
They all specify several dummy ctl_tables for the path name.
This patch implements register_sysctl_table_path that takes
an additional path name, and makes up dummy sysctl nodes
for each component.
Signed-off-by: Olaf Kirch <[email protected]>
include/linux/sysctl.h | 10 ++++++
kernel/sysctl.c | 79 +++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 87 insertions(+), 2 deletions(-)
Index: linux-2.6.18/include/linux/sysctl.h
===================================================================
--- linux-2.6.18.orig/include/linux/sysctl.h
+++ linux-2.6.18/include/linux/sysctl.h
@@ -1006,8 +1006,18 @@ struct ctl_table_header
struct completion *unregistering;
};
+/* struct ctl_path describes where in the hierarchy a table is added */
+struct ctl_path
+{
+ int ctl_name;
+ const char *procname;
+ mode_t mode;
+};
+
struct ctl_table_header * register_sysctl_table(ctl_table * table,
int insert_at_head);
+struct ctl_table_header * register_sysctl_table_path(ctl_table *table,
+ struct ctl_path *path);
void unregister_sysctl_table(struct ctl_table_header * table);
#else /* __KERNEL__ */
Index: linux-2.6.18/kernel/sysctl.c
===================================================================
--- linux-2.6.18.orig/kernel/sysctl.c
+++ linux-2.6.18/kernel/sysctl.c
@@ -135,6 +135,7 @@ static int parse_table(int __user *, int
ctl_table *, void **);
static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos);
+static void __insert_sysctl_table(struct ctl_table_header *, int);
static ctl_table root_table[];
static struct ctl_table_header root_table_header =
@@ -1353,6 +1354,74 @@ struct ctl_table_header *register_sysctl
if (!tmp)
return NULL;
tmp->ctl_table = table;
+ __insert_sysctl_table(tmp, insert_at_head);
+ return tmp;
+}
+
+/**
+ * register_sysctl_table_path - register a systl table below a given node
+ * @npath: The number of entries in the path array.
+ * @path: An array of ctl_path items. We assume that the procname strings
+ * are valid for the lifetime of the registration.
+ * @table: the table structure to register
+ *
+ * This works like register_sysctl_table except that the table isn't
+ * registered at the sysctl root, but at the specified location in the
+ * sysctl hierarchy
+ */
+struct ctl_table_header *register_sysctl_table_path(ctl_table *table,
+ struct ctl_path *path)
+{
+ struct ctl_table_header *header;
+ struct ctl_table *new, **prevp;
+ unsigned int n, npath;
+
+ /* Count the path components. If the path is empty,
+ * fall back to the normal register_sysctl_table() */
+ for (npath = 0; path[npath].procname; ++npath)
+ ;
+
+ if (npath == 0)
+ return register_sysctl_table(table, 0);
+
+ /* For each path component, allocate a 2-element ctl_table array.
+ * The first array element will be filled with the sysctl entry
+ * for this, the second will be the sentinel (ctl_name == 0).
+ *
+ * We allocate everything in one go so that we don't have to
+ * worry about freeing additional memory in unregister_sysctl_table.
+ */
+ header = kzalloc(sizeof(struct ctl_table_header)
+ + 2 * npath * sizeof(struct ctl_table), GFP_KERNEL);
+ if (!header)
+ return NULL;
+ new = (struct ctl_table *) (header + 1);
+
+ /* Now connect the dots */
+ prevp = &header->ctl_table;
+ for (n = 0; n < npath; ++n, ++path) {
+ /* Copy the procname */
+ new->procname = path->procname;
+ new->ctl_name = path->ctl_name;
+ new->mode = path->mode;
+
+ *prevp = new;
+ prevp = &new->child;
+
+ new += 2;
+ }
+
+ *prevp = table;
+ __insert_sysctl_table(header, 0);
+ return header;
+}
+
+/*
+ * Insert ctl_table_header into hierarchy
+ */
+void __insert_sysctl_table(struct ctl_table_header * tmp,
+ int insert_at_head)
+{
INIT_LIST_HEAD(&tmp->ctl_entry);
tmp->used = 0;
tmp->unregistering = NULL;
@@ -1363,9 +1432,8 @@ struct ctl_table_header *register_sysctl
list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
spin_unlock(&sysctl_lock);
#ifdef CONFIG_PROC_FS
- register_proc_table(table, proc_sys_root, tmp);
+ register_proc_table(tmp->ctl_table, proc_sys_root, tmp);
#endif
- return tmp;
}
/**
@@ -2493,6 +2561,12 @@ struct ctl_table_header * register_sysct
return NULL;
}
+struct ctl_table_header * register_sysctl_table_path(ctl_table * table,
+ struct ctl_path * path)
+{
+ return NULL;
+}
+
void unregister_sysctl_table(struct ctl_table_header * table)
{
}
@@ -2512,6 +2586,7 @@ EXPORT_SYMBOL(proc_dostring);
EXPORT_SYMBOL(proc_doulongvec_minmax);
EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
EXPORT_SYMBOL(register_sysctl_table);
+EXPORT_SYMBOL(register_sysctl_table_path);
EXPORT_SYMBOL(sysctl_intvec);
EXPORT_SYMBOL(sysctl_jiffies);
EXPORT_SYMBOL(sysctl_ms_jiffies);
-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys -- and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
NFS maillist - [email protected]
https://lists.sourceforge.net/lists/listinfo/nfs