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>

1 files changed, 10 insertions, 1 deletions

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 3c0767d5a55f..a78556514a87 100644
--- 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);