cachefiles: Implement object lifecycle funcs

Implement allocate, get, see and put functions for the cachefiles_object struct. The members of the struct we're going to need are also added. Additionally, implement a lifecycle tracepoint.

David Howells committed 4 years ago

Commit df98e871 parent 13871ba5 files · +197 −2Browse files

Unified · Split

5 files

fs/cachefiles/interface.c +86 −0
fs/cachefiles/internal.h +33 −2
fs/cachefiles/main.c +16 −0
include/trace/events/cachefiles.h +58 −0
include/trace/events/fscache.h +4 −0

fs/cachefiles/interface.c+86−0

@@ -13,6 +13,92 @@ · 12 unmodified lines
13	13	#include <trace/events/fscache.h>
14	14	#include "internal.h"
15	15
	16	+static atomic_t cachefiles_object_debug_id;
	17	+
	18	+/*
	19	+ * Allocate a cache object record.
	20	+ */
	21	+static
	22	+struct cachefiles_object cachefiles_alloc_object(struct fscache_cookie cookie)
	23	+{
	24	+ struct fscache_volume *vcookie = cookie->volume;
	25	+ struct cachefiles_volume *volume = vcookie->cache_priv;
	26	+ struct cachefiles_object *object;
	27	+
	28	+ _enter("{%s},%x,", vcookie->key, cookie->debug_id);
	29	+
	30	+ object = kmem_cache_zalloc(cachefiles_object_jar, GFP_KERNEL);
	31	+ if (!object)
	32	+ return NULL;
	33	+
	34	+ refcount_set(&object->ref, 1);
	35	+
	36	+ spin_lock_init(&object->lock);
	37	+ INIT_LIST_HEAD(&object->cache_link);
	38	+ object->volume = volume;
	39	+ object->debug_id = atomic_inc_return(&cachefiles_object_debug_id);
	40	+ object->cookie = fscache_get_cookie(cookie, fscache_cookie_get_attach_object);
	41	+
	42	+ fscache_count_object(vcookie->cache);
	43	+ trace_cachefiles_ref(object->debug_id, cookie->debug_id, 1,
	44	+ cachefiles_obj_new);
	45	+ return object;
	46	+}
	47	+
	48	+/*
	49	+ * Note that an object has been seen.
	50	+ */
	51	+void cachefiles_see_object(struct cachefiles_object *object,
	52	+ enum cachefiles_obj_ref_trace why)
	53	+{
	54	+ trace_cachefiles_ref(object->debug_id, object->cookie->debug_id,
	55	+ refcount_read(&object->ref), why);
	56	+}
	57	+
	58	+/*
	59	+ * Increment the usage count on an object;
	60	+ */
	61	+struct cachefiles_object cachefiles_grab_object(struct cachefiles_object object,
	62	+ enum cachefiles_obj_ref_trace why)
	63	+{
	64	+ int r;
	65	+
	66	+ __refcount_inc(&object->ref, &r);
	67	+ trace_cachefiles_ref(object->debug_id, object->cookie->debug_id, r, why);
	68	+ return object;
	69	+}
	70	+
	71	+/*
	72	+ * dispose of a reference to an object
	73	+ */
	74	+void cachefiles_put_object(struct cachefiles_object *object,
	75	+ enum cachefiles_obj_ref_trace why)
	76	+{
	77	+ unsigned int object_debug_id = object->debug_id;
	78	+ unsigned int cookie_debug_id = object->cookie->debug_id;
	79	+ struct fscache_cache *cache;
	80	+ bool done;
	81	+ int r;
	82	+
	83	+ done = __refcount_dec_and_test(&object->ref, &r);
	84	+ trace_cachefiles_ref(object_debug_id, cookie_debug_id, r, why);
	85	+ if (done) {
	86	+ _debug("- kill object OBJ%x", object_debug_id);
	87	+
	88	+ ASSERTCMP(object->file, ==, NULL);
	89	+
	90	+ kfree(object->d_name);
	91	+
	92	+ cache = object->volume->cache->cache;
	93	+ fscache_put_cookie(object->cookie, fscache_cookie_put_object);
	94	+ object->cookie = NULL;
	95	+ kmem_cache_free(cachefiles_object_jar, object);
	96	+ fscache_uncount_object(cache);
	97	+ }
	98	+
	99	+ _leave("");
	100	+}
	101	+
16	102	const struct fscache_cache_ops cachefiles_cache_ops = {
17	103	.name = "cachefiles",
18	104	.acquire_volume = cachefiles_acquire_volume,

fs/cachefiles/internal.h+33−2

@@ -19,6 +19,16 @@ · 18 unmodified lines
19	19	struct cachefiles_cache;
20	20	struct cachefiles_object;
21	21
	22	+enum cachefiles_content {
	23	+ /* These values are saved on disk */
	24	+ CACHEFILES_CONTENT_NO_DATA = 0, /* No content stored */
	25	+ CACHEFILES_CONTENT_SINGLE = 1, /* Content is monolithic, all is present */
	26	+ CACHEFILES_CONTENT_ALL = 2, /* Content is all present, no map */
	27	+ CACHEFILES_CONTENT_BACKFS_MAP = 3, /* Content is piecemeal, mapped through backing fs */
	28	+ CACHEFILES_CONTENT_DIRTY = 4, /* Content is dirty (only seen on disk) */
	29	+ nr__cachefiles_content
	30	+};
	31	+
22	32	/*
23	33	* Cached volume representation.
24	34	*/
@@ -31,10 +41,20 @@ struct cachefiles_volume { · 6 unmodified lines
31	41	};
32	42
33	43	/*
34		− * Data file records.
	44	+ * Backing file state.
35	45	*/
36	46	struct cachefiles_object {
37		− int debug_id; /* debugging ID */
	47	+ struct fscache_cookie cookie; / Netfs data storage object cookie */
	48	+ struct cachefiles_volume volume; / Cache volume that holds this object */
	49	+ struct list_head cache_link; /* Link in cache->_list /
	50	+ struct file file; / The file representing this object */
	51	+ char d_name; / Backing file name */
	52	+ int debug_id;
	53	+ spinlock_t lock;
	54	+ refcount_t ref;
	55	+ u8 d_name_len; /* Length of filename */
	56	+ enum cachefiles_content content_info:8; /* Info about content presence */
	57	+ unsigned long flags;
38	58	};
39	59
40	60	/*
@@ -146,6 +166,17 @@ static inline int cachefiles_inject_remove_error(void) · 105 unmodified lines
146	166	* interface.c
147	167	*/
148	168	extern const struct fscache_cache_ops cachefiles_cache_ops;
	169	+extern void cachefiles_see_object(struct cachefiles_object *object,
	170	+ enum cachefiles_obj_ref_trace why);
	171	+extern struct cachefiles_object cachefiles_grab_object(struct cachefiles_object object,
	172	+ enum cachefiles_obj_ref_trace why);
	173	+extern void cachefiles_put_object(struct cachefiles_object *object,
	174	+ enum cachefiles_obj_ref_trace why);
	175	+
	176	+/*
	177	+ * main.c
	178	+ */
	179	+extern struct kmem_cache *cachefiles_object_jar;
149	180
150	181	/*
151	182	* namei.c

fs/cachefiles/main.c+16−0

@@ -31,6 +31,8 @@ MODULE_DESCRIPTION("Mounted-filesystem based cache"); · 30 unmodified lines
31	31	MODULE_AUTHOR("Red Hat, Inc.");
32	32	MODULE_LICENSE("GPL");
33	33
	34	+struct kmem_cache *cachefiles_object_jar;
	35	+
34	36	static struct miscdevice cachefiles_dev = {
35	37	.minor = MISC_DYNAMIC_MINOR,
36	38	.name = "cachefiles",
@@ -51,9 +53,22 @@ static int __init cachefiles_init(void) · 14 unmodified lines
51	53	if (ret < 0)
52	54	goto error_dev;
53	55
	56	+ /* create an object jar */
	57	+ ret = -ENOMEM;
	58	+ cachefiles_object_jar =
	59	+ kmem_cache_create("cachefiles_object_jar",
	60	+ sizeof(struct cachefiles_object),
	61	+ 0, SLAB_HWCACHE_ALIGN, NULL);
	62	+ if (!cachefiles_object_jar) {
	63	+ pr_notice("Failed to allocate an object jar\n");
	64	+ goto error_object_jar;
	65	+ }
	66	+
54	67	pr_info("Loaded\n");
55	68	return 0;
56	69
	70	+error_object_jar:
	71	+ misc_deregister(&cachefiles_dev);
57	72	error_dev:
58	73	cachefiles_unregister_error_injection();
59	74	error_einj:
@@ -70,6 +85,7 @@ static void __exit cachefiles_exit(void) · 10 unmodified lines
70	85	{
71	86	pr_info("Unloading\n");
72	87
	88	+ kmem_cache_destroy(cachefiles_object_jar);
73	89	misc_deregister(&cachefiles_dev);
74	90	cachefiles_unregister_error_injection();
75	91	}

include/trace/events/cachefiles.h+58−0

@@ -18,6 +18,21 @@ · 17 unmodified lines
18	18	#ifndef __CACHEFILES_DECLARE_TRACE_ENUMS_ONCE_ONLY
19	19	#define __CACHEFILES_DECLARE_TRACE_ENUMS_ONCE_ONLY
20	20
	21	+enum cachefiles_obj_ref_trace {
	22	+ cachefiles_obj_get_ioreq,
	23	+ cachefiles_obj_new,
	24	+ cachefiles_obj_put_alloc_fail,
	25	+ cachefiles_obj_put_detach,
	26	+ cachefiles_obj_put_ioreq,
	27	+ cachefiles_obj_see_clean_commit,
	28	+ cachefiles_obj_see_clean_delete,
	29	+ cachefiles_obj_see_clean_drop_tmp,
	30	+ cachefiles_obj_see_lookup_cookie,
	31	+ cachefiles_obj_see_lookup_failed,
	32	+ cachefiles_obj_see_withdraw_cookie,
	33	+ cachefiles_obj_see_withdrawal,
	34	+};
	35	+
21	36	enum fscache_why_object_killed {
22	37	FSCACHE_OBJECT_IS_STALE,
23	38	FSCACHE_OBJECT_IS_WEIRD,
@@ -66,6 +81,20 @@ enum cachefiles_error_trace { · 42 unmodified lines
66	81	EM(FSCACHE_OBJECT_WAS_RETIRED, "was_retired") \
67	82	E_(FSCACHE_OBJECT_WAS_CULLED, "was_culled")
68	83
	84	+#define cachefiles_obj_ref_traces \
	85	+ EM(cachefiles_obj_get_ioreq, "GET ioreq") \
	86	+ EM(cachefiles_obj_new, "NEW obj") \
	87	+ EM(cachefiles_obj_put_alloc_fail, "PUT alloc_fail") \
	88	+ EM(cachefiles_obj_put_detach, "PUT detach") \
	89	+ EM(cachefiles_obj_put_ioreq, "PUT ioreq") \
	90	+ EM(cachefiles_obj_see_clean_commit, "SEE clean_commit") \
	91	+ EM(cachefiles_obj_see_clean_delete, "SEE clean_delete") \
	92	+ EM(cachefiles_obj_see_clean_drop_tmp, "SEE clean_drop_tmp") \
	93	+ EM(cachefiles_obj_see_lookup_cookie, "SEE lookup_cookie") \
	94	+ EM(cachefiles_obj_see_lookup_failed, "SEE lookup_failed") \
	95	+ EM(cachefiles_obj_see_withdraw_cookie, "SEE withdraw_cookie") \
	96	+ E_(cachefiles_obj_see_withdrawal, "SEE withdrawal")
	97	+
69	98	#define cachefiles_trunc_traces \
70	99	EM(cachefiles_trunc_dio_adjust, "DIOADJ") \
71	100	EM(cachefiles_trunc_expand_tmpfile, "EXPTMP") \
@@ -100,6 +129,7 @@ enum cachefiles_error_trace { · 28 unmodified lines
100	129	#define E_(a, b) TRACE_DEFINE_ENUM(a);
101	130
102	131	cachefiles_obj_kill_traces;
	132	+cachefiles_obj_ref_traces;
103	133	cachefiles_trunc_traces;
104	134	cachefiles_error_traces;
105	135
@@ -113,6 +143,34 @@ cachefiles_error_traces; · 7 unmodified lines
113	143	#define E_(a, b) { a, b }
114	144
115	145
	146	+TRACE_EVENT(cachefiles_ref,
	147	+ TP_PROTO(unsigned int object_debug_id,
	148	+ unsigned int cookie_debug_id,
	149	+ int usage,
	150	+ enum cachefiles_obj_ref_trace why),
	151	+
	152	+ TP_ARGS(object_debug_id, cookie_debug_id, usage, why),
	153	+
	154	+ /* Note that obj may be NULL */
	155	+ TP_STRUCT__entry(
	156	+ __field(unsigned int, obj )
	157	+ __field(unsigned int, cookie )
	158	+ __field(enum cachefiles_obj_ref_trace, why )
	159	+ __field(int, usage )
	160	+ ),
	161	+
	162	+ TP_fast_assign(
	163	+ __entry->obj = object_debug_id;
	164	+ __entry->cookie = cookie_debug_id;
	165	+ __entry->usage = usage;
	166	+ __entry->why = why;
	167	+ ),
	168	+
	169	+ TP_printk("c=%08x o=%08x u=%d %s",
	170	+ __entry->cookie, __entry->obj, __entry->usage,
	171	+ __print_symbolic(__entry->why, cachefiles_obj_ref_traces))
	172	+ );
	173	+
116	174	TRACE_EVENT(cachefiles_lookup,
117	175	TP_PROTO(struct cachefiles_object *obj,
118	176	struct dentry *de),

include/trace/events/fscache.h+4−0

@@ -49,6 +49,7 @@ enum fscache_volume_trace { · 48 unmodified lines
49	49	enum fscache_cookie_trace {
50	50	fscache_cookie_collision,
51	51	fscache_cookie_discard,
	52	+ fscache_cookie_get_attach_object,
52	53	fscache_cookie_get_end_access,
53	54	fscache_cookie_get_hash_collision,
54	55	fscache_cookie_get_inval_work,
@@ -57,6 +58,7 @@ enum fscache_cookie_trace { · 2 unmodified lines
57	58	fscache_cookie_new_acquire,
58	59	fscache_cookie_put_hash_collision,
59	60	fscache_cookie_put_lru,
	61	+ fscache_cookie_put_object,
60	62	fscache_cookie_put_over_queued,
61	63	fscache_cookie_put_relinquish,
62	64	fscache_cookie_put_withdrawn,
@@ -122,6 +124,7 @@ enum fscache_access_trace { · 59 unmodified lines
122	124	#define fscache_cookie_traces \
123	125	EM(fscache_cookie_collision, "COLLIDE") \
124	126	EM(fscache_cookie_discard, "DISCARD ") \
	127	+ EM(fscache_cookie_get_attach_object, "GET attch") \
125	128	EM(fscache_cookie_get_hash_collision, "GET hcoll") \
126	129	EM(fscache_cookie_get_end_access, "GQ endac") \
127	130	EM(fscache_cookie_get_inval_work, "GQ inval") \
@@ -130,6 +133,7 @@ enum fscache_access_trace { · 2 unmodified lines
130	133	EM(fscache_cookie_new_acquire, "NEW acq ") \
131	134	EM(fscache_cookie_put_hash_collision, "PUT hcoll") \
132	135	EM(fscache_cookie_put_lru, "PUT lru ") \
	136	+ EM(fscache_cookie_put_object, "PUT obj ") \
133	137	EM(fscache_cookie_put_over_queued, "PQ overq") \
134	138	EM(fscache_cookie_put_relinquish, "PUT relnq") \
135	139	EM(fscache_cookie_put_withdrawn, "PUT wthdn") \

cachefiles: Implement object lifecycle funcs

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