sysctl: Add sysctl_print_dir and use it in get_subdir

When there are errors it is very nice to know the full sysctl path.
Add a simple function that computes the sysctl path and prints it
out.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 3c0767d5a55faa85ef7be816adcc3cefb56a8ccd..a78556514a873118fbf17b85f19c73139bdcf380 100644 (file)
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -53,6 +53,13 @@ static DEFINE_SPINLOCK(sysctl_lock);
 
 static void drop_sysctl_table(struct ctl_table_header *header);
 
+static void sysctl_print_dir(struct ctl_dir *dir)
+{
+       if (dir->header.parent)
+               sysctl_print_dir(dir->header.parent);
+       printk(KERN_CONT "%s/", dir->header.ctl_table[0].procname);
+}
+
 static int namecmp(const char *name1, int len1, const char *name2, int len2)
 {
        int minlen;
@@ -822,7 +829,9 @@ found:
        subdir->header.nreg++;
 failed:
        if (unlikely(IS_ERR(subdir))) {
-               printk(KERN_ERR "sysctl could not get directory: %*.*s %ld\n",
+               printk(KERN_ERR "sysctl could not get directory: ");
+               sysctl_print_dir(dir);
+               printk(KERN_CONT "/%*.*s %ld\n",
                        namelen, namelen, name, PTR_ERR(subdir));
        }
        drop_sysctl_table(&dir->header);