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authorDavid Howells <dhowells@redhat.com>2018-04-04 13:41:27 +0100
committerDavid Howells <dhowells@redhat.com>2018-04-04 13:41:27 +0100
commita18feb55769b705a44c4107786c4045eae2e87b6 (patch)
tree3db7d160e672aa9f16a0437b767b3d3bbb10ecc8 /fs/fscache
parent2c98425720233ae3e135add0c7e869b32913502f (diff)
downloadlinux-a18feb55769b705a44c4107786c4045eae2e87b6.tar.bz2
fscache: Add tracepoints
Add some tracepoints to fscache: (*) fscache_cookie - Tracks a cookie's usage count. (*) fscache_netfs - Logs registration of a network filesystem, including the pointer to the cookie allocated. (*) fscache_acquire - Logs cookie acquisition. (*) fscache_relinquish - Logs cookie relinquishment. (*) fscache_enable - Logs enablement of a cookie. (*) fscache_disable - Logs disablement of a cookie. (*) fscache_osm - Tracks execution of states in the object state machine. and cachefiles: (*) cachefiles_ref - Tracks a cachefiles object's usage count. (*) cachefiles_lookup - Logs result of lookup_one_len(). (*) cachefiles_mkdir - Logs result of vfs_mkdir(). (*) cachefiles_create - Logs result of vfs_create(). (*) cachefiles_unlink - Logs calls to vfs_unlink(). (*) cachefiles_rename - Logs calls to vfs_rename(). (*) cachefiles_mark_active - Logs an object becoming active. (*) cachefiles_wait_active - Logs a wait for an old object to be destroyed. (*) cachefiles_mark_inactive - Logs an object becoming inactive. (*) cachefiles_mark_buried - Logs the burial of an object. Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs/fscache')
-rw-r--r--fs/fscache/cookie.c46
-rw-r--r--fs/fscache/internal.h16
-rw-r--r--fs/fscache/main.c1
-rw-r--r--fs/fscache/netfs.c3
-rw-r--r--fs/fscache/object.c36
5 files changed, 63 insertions, 39 deletions
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index 98d22f495cd8..20bc3341f113 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -101,7 +101,7 @@ struct fscache_cookie *__fscache_acquire_cookie(
*/
atomic_set(&cookie->n_active, 1);
- atomic_inc(&parent->usage);
+ fscache_cookie_get(parent, fscache_cookie_get_acquire_parent);
atomic_inc(&parent->n_children);
cookie->def = def;
@@ -125,6 +125,8 @@ struct fscache_cookie *__fscache_acquire_cookie(
break;
}
+ trace_fscache_acquire(cookie);
+
if (enable) {
/* if the object is an index then we need do nothing more here
* - we create indices on disk when we need them as an index
@@ -134,7 +136,8 @@ struct fscache_cookie *__fscache_acquire_cookie(
set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags);
} else {
atomic_dec(&parent->n_children);
- __fscache_cookie_put(cookie);
+ fscache_cookie_put(cookie,
+ fscache_cookie_put_acquire_nobufs);
fscache_stat(&fscache_n_acquires_nobufs);
_leave(" = NULL");
return NULL;
@@ -159,6 +162,8 @@ void __fscache_enable_cookie(struct fscache_cookie *cookie,
{
_enter("%p", cookie);
+ trace_fscache_enable(cookie);
+
wait_on_bit_lock(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK,
TASK_UNINTERRUPTIBLE);
@@ -318,7 +323,7 @@ static int fscache_alloc_object(struct fscache_cache *cache,
* attached to the cookie */
if (fscache_attach_object(cookie, object) < 0) {
fscache_stat(&fscache_n_cop_put_object);
- cache->ops->put_object(object);
+ cache->ops->put_object(object, fscache_obj_put_attach_fail);
fscache_stat_d(&fscache_n_cop_put_object);
}
@@ -338,7 +343,7 @@ object_already_extant:
error_put:
fscache_stat(&fscache_n_cop_put_object);
- cache->ops->put_object(object);
+ cache->ops->put_object(object, fscache_obj_put_alloc_fail);
fscache_stat_d(&fscache_n_cop_put_object);
error:
_leave(" = %d", ret);
@@ -398,7 +403,7 @@ static int fscache_attach_object(struct fscache_cookie *cookie,
/* attach to the cookie */
object->cookie = cookie;
- atomic_inc(&cookie->usage);
+ fscache_cookie_get(cookie, fscache_cookie_get_attach_object);
hlist_add_head(&object->cookie_link, &cookie->backing_objects);
fscache_objlist_add(object);
@@ -516,6 +521,8 @@ void __fscache_disable_cookie(struct fscache_cookie *cookie, bool invalidate)
_enter("%p,%u", cookie, invalidate);
+ trace_fscache_disable(cookie);
+
ASSERTCMP(atomic_read(&cookie->n_active), >, 0);
if (atomic_read(&cookie->n_children) != 0) {
@@ -601,6 +608,8 @@ void __fscache_relinquish_cookie(struct fscache_cookie *cookie, bool retire)
cookie, cookie->def->name, cookie->netfs_data,
atomic_read(&cookie->n_active), retire);
+ trace_fscache_relinquish(cookie, retire);
+
/* No further netfs-accessing operations on this cookie permitted */
if (test_and_set_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags))
BUG();
@@ -620,35 +629,38 @@ void __fscache_relinquish_cookie(struct fscache_cookie *cookie, bool retire)
/* Dispose of the netfs's link to the cookie */
ASSERTCMP(atomic_read(&cookie->usage), >, 0);
- fscache_cookie_put(cookie);
+ fscache_cookie_put(cookie, fscache_cookie_put_relinquish);
_leave("");
}
EXPORT_SYMBOL(__fscache_relinquish_cookie);
/*
- * destroy a cookie
+ * Drop a reference to a cookie.
*/
-void __fscache_cookie_put(struct fscache_cookie *cookie)
+void fscache_cookie_put(struct fscache_cookie *cookie,
+ enum fscache_cookie_trace where)
{
struct fscache_cookie *parent;
+ int usage;
_enter("%p", cookie);
- for (;;) {
- _debug("FREE COOKIE %p", cookie);
+ do {
+ usage = atomic_dec_return(&cookie->usage);
+ trace_fscache_cookie(cookie, where, usage);
+
+ if (usage > 0)
+ return;
+ BUG_ON(usage < 0);
+
parent = cookie->parent;
BUG_ON(!hlist_empty(&cookie->backing_objects));
kmem_cache_free(fscache_cookie_jar, cookie);
- if (!parent)
- break;
-
cookie = parent;
- BUG_ON(atomic_read(&cookie->usage) <= 0);
- if (!atomic_dec_and_test(&cookie->usage))
- break;
- }
+ where = fscache_cookie_put_parent;
+ } while (cookie);
_leave("");
}
diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h
index 0ff4b49a0037..c27e2db3004e 100644
--- a/fs/fscache/internal.h
+++ b/fs/fscache/internal.h
@@ -29,6 +29,7 @@
#define pr_fmt(fmt) "FS-Cache: " fmt
#include <linux/fscache-cache.h>
+#include <trace/events/fscache.h>
#include <linux/sched.h>
#define FSCACHE_MIN_THREADS 4
@@ -49,7 +50,8 @@ extern struct fscache_cache *fscache_select_cache_for_object(
extern struct kmem_cache *fscache_cookie_jar;
extern void fscache_cookie_init_once(void *);
-extern void __fscache_cookie_put(struct fscache_cookie *);
+extern void fscache_cookie_put(struct fscache_cookie *,
+ enum fscache_cookie_trace);
/*
* fsdef.c
@@ -311,14 +313,12 @@ static inline void fscache_raise_event(struct fscache_object *object,
fscache_enqueue_object(object);
}
-/*
- * drop a reference to a cookie
- */
-static inline void fscache_cookie_put(struct fscache_cookie *cookie)
+static inline void fscache_cookie_get(struct fscache_cookie *cookie,
+ enum fscache_cookie_trace where)
{
- BUG_ON(atomic_read(&cookie->usage) <= 0);
- if (atomic_dec_and_test(&cookie->usage))
- __fscache_cookie_put(cookie);
+ int usage = atomic_inc_return(&cookie->usage);
+
+ trace_fscache_cookie(cookie, where, usage);
}
/*
diff --git a/fs/fscache/main.c b/fs/fscache/main.c
index 249968dcbf5c..7dce110bf17d 100644
--- a/fs/fscache/main.c
+++ b/fs/fscache/main.c
@@ -16,6 +16,7 @@
#include <linux/completion.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
+#define CREATE_TRACE_POINTS
#include "internal.h"
MODULE_DESCRIPTION("FS Cache Manager");
diff --git a/fs/fscache/netfs.c b/fs/fscache/netfs.c
index a8aa00be4444..c816600d1dde 100644
--- a/fs/fscache/netfs.c
+++ b/fs/fscache/netfs.c
@@ -60,7 +60,7 @@ int __fscache_register_netfs(struct fscache_netfs *netfs)
goto already_registered;
}
- atomic_inc(&cookie->parent->usage);
+ fscache_cookie_get(cookie->parent, fscache_cookie_get_register_netfs);
atomic_inc(&cookie->parent->n_children);
netfs->primary_index = cookie;
@@ -68,6 +68,7 @@ int __fscache_register_netfs(struct fscache_netfs *netfs)
ret = 0;
pr_notice("Netfs '%s' registered for caching\n", netfs->name);
+ trace_fscache_netfs(netfs);
already_registered:
up_write(&fscache_addremove_sem);
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index 7a182c87f378..99afe64352a5 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -138,8 +138,10 @@ static const struct fscache_transition fscache_osm_run_oob[] = {
{ 0, NULL }
};
-static int fscache_get_object(struct fscache_object *);
-static void fscache_put_object(struct fscache_object *);
+static int fscache_get_object(struct fscache_object *,
+ enum fscache_obj_ref_trace);
+static void fscache_put_object(struct fscache_object *,
+ enum fscache_obj_ref_trace);
static bool fscache_enqueue_dependents(struct fscache_object *, int);
static void fscache_dequeue_object(struct fscache_object *);
@@ -170,6 +172,7 @@ static void fscache_object_sm_dispatcher(struct fscache_object *object)
const struct fscache_transition *t;
const struct fscache_state *state, *new_state;
unsigned long events, event_mask;
+ bool oob;
int event = -1;
ASSERT(object != NULL);
@@ -188,6 +191,7 @@ restart_masked:
if (events & object->oob_event_mask) {
_debug("{OBJ%x} oob %lx",
object->debug_id, events & object->oob_event_mask);
+ oob = true;
for (t = object->oob_table; t->events; t++) {
if (events & t->events) {
state = t->transit_to;
@@ -199,6 +203,7 @@ restart_masked:
}
}
}
+ oob = false;
/* Wait states are just transition tables */
if (!state->work) {
@@ -207,6 +212,8 @@ restart_masked:
if (events & t->events) {
new_state = t->transit_to;
event = fls(events & t->events) - 1;
+ trace_fscache_osm(object, state,
+ true, false, event);
clear_bit(event, &object->events);
_debug("{OBJ%x} ev %d: %s -> %s",
object->debug_id, event,
@@ -226,6 +233,7 @@ restart_masked:
execute_work_state:
_debug("{OBJ%x} exec %s", object->debug_id, state->name);
+ trace_fscache_osm(object, state, false, oob, event);
new_state = state->work(object, event);
event = -1;
if (new_state == NO_TRANSIT) {
@@ -279,7 +287,7 @@ static void fscache_object_work_func(struct work_struct *work)
start = jiffies;
fscache_object_sm_dispatcher(object);
fscache_hist(fscache_objs_histogram, start);
- fscache_put_object(object);
+ fscache_put_object(object, fscache_obj_put_work);
}
/**
@@ -397,7 +405,7 @@ static const struct fscache_state *fscache_initialise_object(struct fscache_obje
fscache_stat(&fscache_n_cop_grab_object);
success = false;
if (fscache_object_is_live(parent) &&
- object->cache->ops->grab_object(object)) {
+ object->cache->ops->grab_object(object, fscache_obj_get_add_to_deps)) {
list_add(&object->dep_link, &parent->dependents);
success = true;
}
@@ -745,7 +753,7 @@ static const struct fscache_state *fscache_drop_object(struct fscache_object *ob
}
/* this just shifts the object release to the work processor */
- fscache_put_object(object);
+ fscache_put_object(object, fscache_obj_put_drop_obj);
fscache_stat(&fscache_n_object_dead);
_leave("");
@@ -755,12 +763,13 @@ static const struct fscache_state *fscache_drop_object(struct fscache_object *ob
/*
* get a ref on an object
*/
-static int fscache_get_object(struct fscache_object *object)
+static int fscache_get_object(struct fscache_object *object,
+ enum fscache_obj_ref_trace why)
{
int ret;
fscache_stat(&fscache_n_cop_grab_object);
- ret = object->cache->ops->grab_object(object) ? 0 : -EAGAIN;
+ ret = object->cache->ops->grab_object(object, why) ? 0 : -EAGAIN;
fscache_stat_d(&fscache_n_cop_grab_object);
return ret;
}
@@ -768,10 +777,11 @@ static int fscache_get_object(struct fscache_object *object)
/*
* Discard a ref on an object
*/
-static void fscache_put_object(struct fscache_object *object)
+static void fscache_put_object(struct fscache_object *object,
+ enum fscache_obj_ref_trace why)
{
fscache_stat(&fscache_n_cop_put_object);
- object->cache->ops->put_object(object);
+ object->cache->ops->put_object(object, why);
fscache_stat_d(&fscache_n_cop_put_object);
}
@@ -786,7 +796,7 @@ void fscache_object_destroy(struct fscache_object *object)
fscache_objlist_remove(object);
/* We can get rid of the cookie now */
- fscache_cookie_put(object->cookie);
+ fscache_cookie_put(object->cookie, fscache_cookie_put_object);
object->cookie = NULL;
}
EXPORT_SYMBOL(fscache_object_destroy);
@@ -798,7 +808,7 @@ void fscache_enqueue_object(struct fscache_object *object)
{
_enter("{OBJ%x}", object->debug_id);
- if (fscache_get_object(object) >= 0) {
+ if (fscache_get_object(object, fscache_obj_get_queue) >= 0) {
wait_queue_head_t *cong_wq =
&get_cpu_var(fscache_object_cong_wait);
@@ -806,7 +816,7 @@ void fscache_enqueue_object(struct fscache_object *object)
if (fscache_object_congested())
wake_up(cong_wq);
} else
- fscache_put_object(object);
+ fscache_put_object(object, fscache_obj_put_queue);
put_cpu_var(fscache_object_cong_wait);
}
@@ -866,7 +876,7 @@ static bool fscache_enqueue_dependents(struct fscache_object *object, int event)
list_del_init(&dep->dep_link);
fscache_raise_event(dep, event);
- fscache_put_object(dep);
+ fscache_put_object(dep, fscache_obj_put_enq_dep);
if (!list_empty(&object->dependents) && need_resched()) {
ret = false;