FS-Cache: Add use of /proc and presentation of statistics

Make FS-Cache create its /proc interface and present various statistical
information through it.  Also provide the functions for updating this
information.

These features are enabled by:

	CONFIG_FSCACHE_PROC
	CONFIG_FSCACHE_STATS
	CONFIG_FSCACHE_HISTOGRAM

The /proc directory for FS-Cache is also exported so that caching modules can
add their own statistics there too.

The FS-Cache module is loadable at this point, and the statistics files can be
examined by userspace:

	cat /proc/fs/fscache/stats
	cat /proc/fs/fscache/histogram

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/fs/fscache/main.c b/fs/fscache/main.c
index 76f7c69079c0..7c734b7fb18e 100644
--- a/fs/fscache/main.c
+++ b/fs/fscache/main.c
@@ -52,9 +52,15 @@ static int __init fscache_init(void)
         if (ret < 0)
                 goto error_slow_work;
 
+        ret = fscache_proc_init();
+        if (ret < 0)
+                goto error_proc;
+
         printk(KERN_NOTICE "FS-Cache: Loaded\n");
         return 0;
 
+error_proc:
+        slow_work_unregister_user();
 error_slow_work:
         return ret;
 }
@@ -68,6 +74,7 @@ static void __exit fscache_exit(void)
 {
         _enter("");
 
+        fscache_proc_cleanup();
         slow_work_unregister_user();
         printk(KERN_NOTICE "FS-Cache: Unloaded\n");
 }