FS-Cache: Count the number of initialised operations

Count and display through /proc/fs/fscache/stats the number of initialised
operations.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Steve Dickson <steved@redhat.com>
Acked-by: Jeff Layton <jeff.layton@primarydata.com>

Documentation/filesystems/caching/fscache.txt

@@ -284,8 +284,9 @@ proc files.
 		enq=N	Number of times async ops queued for processing
 		can=N	Number of async ops cancelled
 		rej=N	Number of async ops rejected due to object lookup/create failure
+		ini=N	Number of async ops initialised
 		dfr=N	Number of async ops queued for deferred release
-		rel=N	Number of async ops released
+		rel=N	Number of async ops released (should equal ini=N when idle)
 		gc=N	Number of deferred-release async ops garbage collected
 	CacheOp	alo=N	Number of in-progress alloc_object() cache ops
 		luo=N	Number of in-progress lookup_object() cache ops

fs/fscache/internal.h

@@ -165,6 +165,7 @@ extern atomic_t fscache_n_op_pend;
 extern atomic_t fscache_n_op_run;
 extern atomic_t fscache_n_op_enqueue;
 extern atomic_t fscache_n_op_deferred_release;
+extern atomic_t fscache_n_op_initialised;
 extern atomic_t fscache_n_op_release;
 extern atomic_t fscache_n_op_gc;
 extern atomic_t fscache_n_op_cancelled;

fs/fscache/operation.c

@@ -39,6 +39,7 @@ void fscache_operation_init(struct fscache_operation *op,
 	op->processor = processor;
 	op->release = release;
 	INIT_LIST_HEAD(&op->pend_link);
+	fscache_stat(&fscache_n_op_initialised);
 }
 EXPORT_SYMBOL(fscache_operation_init);
 

fs/fscache/stats.c

@@ -23,6 +23,7 @@ atomic_t fscache_n_op_run;
 atomic_t fscache_n_op_enqueue;
 atomic_t fscache_n_op_requeue;
 atomic_t fscache_n_op_deferred_release;
+atomic_t fscache_n_op_initialised;
 atomic_t fscache_n_op_release;
 atomic_t fscache_n_op_gc;
 atomic_t fscache_n_op_cancelled;
@@ -251,7 +252,8 @@ static int fscache_stats_show(struct seq_file *m, void *v)
 		   atomic_read(&fscache_n_op_enqueue),
 		   atomic_read(&fscache_n_op_cancelled),
 		   atomic_read(&fscache_n_op_rejected));
-	seq_printf(m, "Ops    : dfr=%u rel=%u gc=%u\n",
+	seq_printf(m, "Ops    : ini=%u dfr=%u rel=%u gc=%u\n",
+		   atomic_read(&fscache_n_op_initialised),
 		   atomic_read(&fscache_n_op_deferred_release),
 		   atomic_read(&fscache_n_op_release),
 		   atomic_read(&fscache_n_op_gc));