Commit 08c2e3d0 authored by David Howells's avatar David Howells
Browse files

fscache: Add more tracepoints 



Add more tracepoints to fscache, including:

 (*) fscache_page - Tracks netfs pages known to fscache.

 (*) fscache_check_page - Tracks the netfs querying whether a page is
     pending storage.

 (*) fscache_wake_cookie - Tracks cookies being woken up after a page
     completes/aborts storage in the cache.

 (*) fscache_op - Tracks operations being initialised.

 (*) fscache_wrote_page - Tracks return of the backend write_page op.

 (*) fscache_gang_lookup - Tracks lookup of pages to be stored in the write
     operation.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
parent a18feb55

fs/fscache/cookie.c

+2 −1
Original line number Diff line number Diff line
@@ -691,10 +691,11 @@ int __fscache_check_consistency(struct fscache_cookie *cookie) 
	if (!op)

		return -ENOMEM;



	fscache_operation_init(op, NULL, NULL, NULL);

	fscache_operation_init(cookie, op, NULL, NULL, NULL);

	op->flags = FSCACHE_OP_MYTHREAD |

		(1 << FSCACHE_OP_WAITING) |

		(1 << FSCACHE_OP_UNUSE_COOKIE);

	trace_fscache_page_op(cookie, NULL, op, fscache_page_op_check_consistency);



	spin_lock(&cookie->lock);

fs/fscache/object.c

+2 −1
Original line number Diff line number Diff line
@@ -982,11 +982,12 @@ static const struct fscache_state *_fscache_invalidate_object(struct fscache_obj 
	if (!op)

		goto nomem;



	fscache_operation_init(op, object->cache->ops->invalidate_object,

	fscache_operation_init(cookie, op, object->cache->ops->invalidate_object,

			       NULL, NULL);

	op->flags = FSCACHE_OP_ASYNC |

		(1 << FSCACHE_OP_EXCLUSIVE) |

		(1 << FSCACHE_OP_UNUSE_COOKIE);

	trace_fscache_page_op(cookie, NULL, op, fscache_page_op_invalidate);



	spin_lock(&cookie->lock);

	if (fscache_submit_exclusive_op(object, op) < 0)

fs/fscache/operation.c

+25 −1
Original line number Diff line number Diff line
@@ -32,7 +32,8 @@ static void fscache_operation_dummy_cancel(struct fscache_operation *op) 
 * Do basic initialisation of an operation.  The caller must still set flags,

 * object and processor if needed.

 */

void fscache_operation_init(struct fscache_operation *op,

void fscache_operation_init(struct fscache_cookie *cookie,

			    struct fscache_operation *op,

			    fscache_operation_processor_t processor,

			    fscache_operation_cancel_t cancel,

			    fscache_operation_release_t release)
@@ -46,6 +47,7 @@ void fscache_operation_init(struct fscache_operation *op, 
	op->release = release;

	INIT_LIST_HEAD(&op->pend_link);

	fscache_stat(&fscache_n_op_initialised);

	trace_fscache_op(cookie, op, fscache_op_init);

}

EXPORT_SYMBOL(fscache_operation_init);
@@ -59,6 +61,8 @@ EXPORT_SYMBOL(fscache_operation_init); 
 */

void fscache_enqueue_operation(struct fscache_operation *op)

{

	struct fscache_cookie *cookie = op->object->cookie;

	

	_enter("{OBJ%x OP%x,%u}",

	       op->object->debug_id, op->debug_id, atomic_read(&op->usage));
@@ -71,12 +75,14 @@ void fscache_enqueue_operation(struct fscache_operation *op) 
	fscache_stat(&fscache_n_op_enqueue);

	switch (op->flags & FSCACHE_OP_TYPE) {

	case FSCACHE_OP_ASYNC:

		trace_fscache_op(cookie, op, fscache_op_enqueue_async);

		_debug("queue async");

		atomic_inc(&op->usage);

		if (!queue_work(fscache_op_wq, &op->work))

			fscache_put_operation(op);

		break;

	case FSCACHE_OP_MYTHREAD:

		trace_fscache_op(cookie, op, fscache_op_enqueue_mythread);

		_debug("queue for caller's attention");

		break;

	default:
@@ -101,6 +107,8 @@ static void fscache_run_op(struct fscache_object *object, 
		wake_up_bit(&op->flags, FSCACHE_OP_WAITING);

	if (op->processor)

		fscache_enqueue_operation(op);

	else

		trace_fscache_op(object->cookie, op, fscache_op_run);

	fscache_stat(&fscache_n_op_run);

}
@@ -155,6 +163,8 @@ int fscache_submit_exclusive_op(struct fscache_object *object, 


	_enter("{OBJ%x OP%x},", object->debug_id, op->debug_id);



	trace_fscache_op(object->cookie, op, fscache_op_submit_ex);



	ASSERTCMP(op->state, ==, FSCACHE_OP_ST_INITIALISED);

	ASSERTCMP(atomic_read(&op->usage), >, 0);
@@ -240,6 +250,8 @@ int fscache_submit_op(struct fscache_object *object, 
	_enter("{OBJ%x OP%x},{%u}",

	       object->debug_id, op->debug_id, atomic_read(&op->usage));



	trace_fscache_op(object->cookie, op, fscache_op_submit);



	ASSERTCMP(op->state, ==, FSCACHE_OP_ST_INITIALISED);

	ASSERTCMP(atomic_read(&op->usage), >, 0);
@@ -357,6 +369,8 @@ int fscache_cancel_op(struct fscache_operation *op, 


	_enter("OBJ%x OP%x}", op->object->debug_id, op->debug_id);



	trace_fscache_op(object->cookie, op, fscache_op_cancel);



	ASSERTCMP(op->state, >=, FSCACHE_OP_ST_PENDING);

	ASSERTCMP(op->state, !=, FSCACHE_OP_ST_CANCELLED);

	ASSERTCMP(atomic_read(&op->usage), >, 0);
@@ -419,6 +433,8 @@ void fscache_cancel_all_ops(struct fscache_object *object) 
		fscache_stat(&fscache_n_op_cancelled);

		list_del_init(&op->pend_link);



		trace_fscache_op(object->cookie, op, fscache_op_cancel_all);



		ASSERTCMP(op->state, ==, FSCACHE_OP_ST_PENDING);

		op->cancel(op);

		op->state = FSCACHE_OP_ST_CANCELLED;
@@ -454,9 +470,11 @@ void fscache_op_complete(struct fscache_operation *op, bool cancelled) 
	spin_lock(&object->lock);



	if (!cancelled) {

		trace_fscache_op(object->cookie, op, fscache_op_completed);

		op->state = FSCACHE_OP_ST_COMPLETE;

	} else {

		op->cancel(op);

		trace_fscache_op(object->cookie, op, fscache_op_cancelled);

		op->state = FSCACHE_OP_ST_CANCELLED;

	}
@@ -488,6 +506,8 @@ void fscache_put_operation(struct fscache_operation *op) 
	if (!atomic_dec_and_test(&op->usage))

		return;



	trace_fscache_op(op->object->cookie, op, fscache_op_put);



	_debug("PUT OP");

	ASSERTIFCMP(op->state != FSCACHE_OP_ST_INITIALISED &&

		    op->state != FSCACHE_OP_ST_COMPLETE,
@@ -563,6 +583,8 @@ void fscache_operation_gc(struct work_struct *work) 
		spin_unlock(&cache->op_gc_list_lock);



		object = op->object;

		trace_fscache_op(object->cookie, op, fscache_op_gc);



		spin_lock(&object->lock);



		_debug("GC DEFERRED REL OBJ%x OP%x",
@@ -601,6 +623,8 @@ void fscache_op_work_func(struct work_struct *work) 
	_enter("{OBJ%x OP%x,%d}",

	       op->object->debug_id, op->debug_id, atomic_read(&op->usage));



	trace_fscache_op(op->object->cookie, op, fscache_op_work);



	ASSERT(op->processor != NULL);

	start = jiffies;

	op->processor(op);

fs/fscache/page.c

+47 −4
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ bool __fscache_check_page_write(struct fscache_cookie *cookie, struct page *page 
	rcu_read_lock();

	val = radix_tree_lookup(&cookie->stores, page->index);

	rcu_read_unlock();

	trace_fscache_check_page(cookie, page, val, 0);



	return val != NULL;

}
@@ -39,6 +40,8 @@ void __fscache_wait_on_page_write(struct fscache_cookie *cookie, struct page *pa 
{

	wait_queue_head_t *wq = bit_waitqueue(&cookie->flags, 0);



	trace_fscache_page(cookie, page, fscache_page_write_wait);



	wait_event(*wq, !__fscache_check_page_write(cookie, page));

}

EXPORT_SYMBOL(__fscache_wait_on_page_write);
@@ -69,6 +72,8 @@ bool __fscache_maybe_release_page(struct fscache_cookie *cookie, 


	_enter("%p,%p,%x", cookie, page, gfp);



	trace_fscache_page(cookie, page, fscache_page_maybe_release);



try_again:

	rcu_read_lock();

	val = radix_tree_lookup(&cookie->stores, page->index);
@@ -101,6 +106,7 @@ try_again: 
	}



	xpage = radix_tree_delete(&cookie->stores, page->index);

	trace_fscache_page(cookie, page, fscache_page_radix_delete);

	spin_unlock(&cookie->stores_lock);



	if (xpage) {
@@ -112,6 +118,7 @@ try_again: 
	}



	wake_up_bit(&cookie->flags, 0);

	trace_fscache_wake_cookie(cookie);

	if (xpage)

		put_page(xpage);

	__fscache_uncache_page(cookie, page);
@@ -144,7 +151,7 @@ static void fscache_end_page_write(struct fscache_object *object, 
				   struct page *page)

{

	struct fscache_cookie *cookie;

	struct page *xpage = NULL;

	struct page *xpage = NULL, *val;



	spin_lock(&object->lock);

	cookie = object->cookie;
@@ -154,13 +161,24 @@ static void fscache_end_page_write(struct fscache_object *object, 
		spin_lock(&cookie->stores_lock);

		radix_tree_tag_clear(&cookie->stores, page->index,

				     FSCACHE_COOKIE_STORING_TAG);

		trace_fscache_page(cookie, page, fscache_page_radix_clear_store);

		if (!radix_tree_tag_get(&cookie->stores, page->index,

					FSCACHE_COOKIE_PENDING_TAG)) {

			fscache_stat(&fscache_n_store_radix_deletes);

			xpage = radix_tree_delete(&cookie->stores, page->index);

			trace_fscache_page(cookie, page, fscache_page_radix_delete);

			trace_fscache_page(cookie, page, fscache_page_write_end);



			val = radix_tree_lookup(&cookie->stores, page->index);

			trace_fscache_check_page(cookie, page, val, 1);

		} else {

			trace_fscache_page(cookie, page, fscache_page_write_end_pend);

		}

		spin_unlock(&cookie->stores_lock);

		wake_up_bit(&cookie->flags, 0);

		trace_fscache_wake_cookie(cookie);

	} else {

		trace_fscache_page(cookie, page, fscache_page_write_end_noc);

	}

	spin_unlock(&object->lock);

	if (xpage)
@@ -215,7 +233,8 @@ int __fscache_attr_changed(struct fscache_cookie *cookie) 
		return -ENOMEM;

	}



	fscache_operation_init(op, fscache_attr_changed_op, NULL, NULL);

	fscache_operation_init(cookie, op, fscache_attr_changed_op, NULL, NULL);

	trace_fscache_page_op(cookie, NULL, op, fscache_page_op_attr_changed);

	op->flags = FSCACHE_OP_ASYNC |

		(1 << FSCACHE_OP_EXCLUSIVE) |

		(1 << FSCACHE_OP_UNUSE_COOKIE);
@@ -299,7 +318,7 @@ static struct fscache_retrieval *fscache_alloc_retrieval( 
		return NULL;

	}



	fscache_operation_init(&op->op, NULL,

	fscache_operation_init(cookie, &op->op, NULL,

			       fscache_do_cancel_retrieval,

			       fscache_release_retrieval_op);

	op->op.flags	= FSCACHE_OP_MYTHREAD |
@@ -370,6 +389,7 @@ int fscache_wait_for_operation_activation(struct fscache_object *object, 
		fscache_stat(stat_op_waits);

	if (wait_on_bit(&op->flags, FSCACHE_OP_WAITING,

			TASK_INTERRUPTIBLE) != 0) {

		trace_fscache_op(object->cookie, op, fscache_op_signal);

		ret = fscache_cancel_op(op, false);

		if (ret == 0)

			return -ERESTARTSYS;
@@ -391,6 +411,7 @@ check_if_dead: 
	if (unlikely(fscache_object_is_dying(object) ||

		     fscache_cache_is_broken(object))) {

		enum fscache_operation_state state = op->state;

		trace_fscache_op(object->cookie, op, fscache_op_signal);

		fscache_cancel_op(op, true);

		if (stat_object_dead)

			fscache_stat(stat_object_dead);
@@ -445,6 +466,7 @@ int __fscache_read_or_alloc_page(struct fscache_cookie *cookie, 
		return -ENOMEM;

	}

	atomic_set(&op->n_pages, 1);

	trace_fscache_page_op(cookie, page, &op->op, fscache_page_op_retr_one);



	spin_lock(&cookie->lock);
@@ -573,6 +595,7 @@ int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie, 
	if (!op)

		return -ENOMEM;

	atomic_set(&op->n_pages, *nr_pages);

	trace_fscache_page_op(cookie, NULL, &op->op, fscache_page_op_retr_multi);



	spin_lock(&cookie->lock);
@@ -684,6 +707,7 @@ int __fscache_alloc_page(struct fscache_cookie *cookie, 
	if (!op)

		return -ENOMEM;

	atomic_set(&op->n_pages, 1);

	trace_fscache_page_op(cookie, page, &op->op, fscache_page_op_alloc_one);



	spin_lock(&cookie->lock);
@@ -813,9 +837,11 @@ again: 
	fscache_stat(&fscache_n_store_calls);



	/* find a page to store */

	results[0] = NULL;

	page = NULL;

	n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, 1,

				       FSCACHE_COOKIE_PENDING_TAG);

	trace_fscache_gang_lookup(cookie, &op->op, results, n, op->store_limit);

	if (n != 1)

		goto superseded;

	page = results[0];
@@ -825,6 +851,7 @@ again: 
			   FSCACHE_COOKIE_STORING_TAG);

	radix_tree_tag_clear(&cookie->stores, page->index,

			     FSCACHE_COOKIE_PENDING_TAG);

	trace_fscache_page(cookie, page, fscache_page_radix_pend2store);



	spin_unlock(&cookie->stores_lock);

	spin_unlock(&object->lock);
@@ -836,6 +863,7 @@ again: 
	fscache_stat(&fscache_n_cop_write_page);

	ret = object->cache->ops->write_page(op, page);

	fscache_stat_d(&fscache_n_cop_write_page);

	trace_fscache_wrote_page(cookie, page, &op->op, ret);

	fscache_end_page_write(object, page);

	if (ret < 0) {

		fscache_abort_object(object);
@@ -849,6 +877,7 @@ again: 


discard_page:

	fscache_stat(&fscache_n_store_pages_over_limit);

	trace_fscache_wrote_page(cookie, page, &op->op, -ENOBUFS);

	fscache_end_page_write(object, page);

	goto again;
@@ -887,6 +916,8 @@ void fscache_invalidate_writes(struct fscache_cookie *cookie) 
		for (i = n - 1; i >= 0; i--) {

			page = results[i];

			radix_tree_delete(&cookie->stores, page->index);

			trace_fscache_page(cookie, page, fscache_page_radix_delete);

			trace_fscache_page(cookie, page, fscache_page_inval);

		}



		spin_unlock(&cookie->stores_lock);
@@ -896,6 +927,7 @@ void fscache_invalidate_writes(struct fscache_cookie *cookie) 
	}



	wake_up_bit(&cookie->flags, 0);

	trace_fscache_wake_cookie(cookie);



	_leave("");

}
@@ -954,7 +986,7 @@ int __fscache_write_page(struct fscache_cookie *cookie, 
	if (!op)

		goto nomem;



	fscache_operation_init(&op->op, fscache_write_op, NULL,

	fscache_operation_init(cookie, &op->op, fscache_write_op, NULL,

			       fscache_release_write_op);

	op->op.flags = FSCACHE_OP_ASYNC |

		(1 << FSCACHE_OP_WAITING) |
@@ -964,6 +996,8 @@ int __fscache_write_page(struct fscache_cookie *cookie, 
	if (ret < 0)

		goto nomem_free;



	trace_fscache_page_op(cookie, page, &op->op, fscache_page_op_write_one);



	ret = -ENOBUFS;

	spin_lock(&cookie->lock);
@@ -975,6 +1009,8 @@ int __fscache_write_page(struct fscache_cookie *cookie, 
	if (test_bit(FSCACHE_IOERROR, &object->cache->flags))

		goto nobufs;



	trace_fscache_page(cookie, page, fscache_page_write);



	/* add the page to the pending-storage radix tree on the backing

	 * object */

	spin_lock(&object->lock);
@@ -990,8 +1026,10 @@ int __fscache_write_page(struct fscache_cookie *cookie, 
		goto nobufs_unlock_obj;

	}



	trace_fscache_page(cookie, page, fscache_page_radix_insert);

	radix_tree_tag_set(&cookie->stores, page->index,

			   FSCACHE_COOKIE_PENDING_TAG);

	trace_fscache_page(cookie, page, fscache_page_radix_set_pend);

	get_page(page);



	/* we only want one writer at a time, but we do need to queue new
@@ -1034,6 +1072,7 @@ already_pending: 
submit_failed:

	spin_lock(&cookie->stores_lock);

	radix_tree_delete(&cookie->stores, page->index);

	trace_fscache_page(cookie, page, fscache_page_radix_delete);

	spin_unlock(&cookie->stores_lock);

	wake_cookie = __fscache_unuse_cookie(cookie);

	put_page(page);
@@ -1080,6 +1119,8 @@ void __fscache_uncache_page(struct fscache_cookie *cookie, struct page *page) 
	if (!PageFsCache(page))

		goto done;



	trace_fscache_page(cookie, page, fscache_page_uncache);



	/* get the object */

	spin_lock(&cookie->lock);
@@ -1128,6 +1169,8 @@ void fscache_mark_page_cached(struct fscache_retrieval *op, struct page *page) 
	atomic_inc(&fscache_n_marks);

#endif



	trace_fscache_page(cookie, page, fscache_page_cached);



	_debug("- mark %p{%lx}", page, page->index);

	if (TestSetPageFsCache(page)) {

		static bool once_only;

include/linux/fscache-cache.h

+2 −1
Original line number Diff line number Diff line
@@ -135,7 +135,8 @@ extern void fscache_op_work_func(struct work_struct *work); 
extern void fscache_enqueue_operation(struct fscache_operation *);

extern void fscache_op_complete(struct fscache_operation *, bool);

extern void fscache_put_operation(struct fscache_operation *);

extern void fscache_operation_init(struct fscache_operation *,

extern void fscache_operation_init(struct fscache_cookie *,

				   struct fscache_operation *,

				   fscache_operation_processor_t,

				   fscache_operation_cancel_t,

				   fscache_operation_release_t);

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