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: David Howells <dhowells@redhat.com>
diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index b9f18bf..810b33a 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -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 @@ bool __fscache_maybe_release_page(struct fscache_cookie *cookie,
}
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 @@ bool __fscache_maybe_release_page(struct fscache_cookie *cookie,
}
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 @@ int fscache_wait_for_operation_activation(struct fscache_object *object,
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 @@ static void fscache_write_op(struct fscache_operation *_op)
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 @@ static void fscache_write_op(struct fscache_operation *_op)
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 @@ static void fscache_write_op(struct fscache_operation *_op)
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 @@ static void fscache_write_op(struct fscache_operation *_op)
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 @@ int __fscache_write_page(struct fscache_cookie *cookie,
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;