diff mbox series

[V5,2/5] cachefiles: extract ondemand info field from cachefiles_object

Message ID 20230329140155.53272-3-zhujia.zj@bytedance.com
State New
Headers
Series Introduce daemon failover mechanism to recover from crashing |

Commit Message

Jia Zhu March 29, 2023, 2:01 p.m. UTC 
  We'll introduce a @work_struct field for @object in subsequent patches,
it will enlarge the size of @object.
As the result of that, this commit extracts ondemand info field from
@object.

Signed-off-by: Jia Zhu <zhujia.zj@bytedance.com>
---
 fs/cachefiles/interface.c |  7 ++++++-
 fs/cachefiles/internal.h  | 26 ++++++++++++++++++++++----
 fs/cachefiles/ondemand.c  | 34 ++++++++++++++++++++++++++++------
 3 files changed, 56 insertions(+), 11 deletions(-)

Comments

David Howells April 14, 2023, 1:51 p.m. UTC | #1 
Jia Zhu <zhujia.zj@bytedance.com> wrote:

>  #define CACHEFILES_OBJECT_STATE_FUNCS(_state, _STATE)	\
>  static inline bool								\
>  cachefiles_ondemand_object_is_##_state(const struct cachefiles_object *object) \
>  {												\
> -	return object->state == CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
> +	return object->ondemand->state == CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
>  }												\
>  												\
>  static inline void								\
>  cachefiles_ondemand_set_object_##_state(struct cachefiles_object *object) \
>  {												\
> -	object->state = CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
> +	object->ondemand->state = CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
>  }

I wonder if those need barriers - smp_load_acquire() and smp_store_release().

David
Jia Zhu April 14, 2023, 3:45 p.m. UTC | #2 
在 2023/4/14 21:51, David Howells 写道:
> Jia Zhu <zhujia.zj@bytedance.com> wrote:
> 
>>   #define CACHEFILES_OBJECT_STATE_FUNCS(_state, _STATE)	\
>>   static inline bool								\
>>   cachefiles_ondemand_object_is_##_state(const struct cachefiles_object *object) \
>>   {												\
>> -	return object->state == CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
>> +	return object->ondemand->state == CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
>>   }												\
>>   												\
>>   static inline void								\
>>   cachefiles_ondemand_set_object_##_state(struct cachefiles_object *object) \
>>   {												\
>> -	object->state = CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
>> +	object->ondemand->state = CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
>>   }
> 
> I wonder if those need barriers - smp_load_acquire() and smp_store_release().
> 
> David

There are three object states: OPEN, CLOSE, REOPENING.

Here is no logic in the code such like: A has to watching and waiting
for B's status change.

And so far I haven't constructed a scenario requires barrier pairs. Thus
I didn't add barriers here.

Jia
>
diff mbox series

Patch

diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index 40052bdb33655..35ba2117a6f65 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -31,6 +31,11 @@  struct cachefiles_object *cachefiles_alloc_object(struct fscache_cookie *cookie)
 	if (!object)
 		return NULL;
 
+	if (cachefiles_ondemand_init_obj_info(object, volume)) {
+		kmem_cache_free(cachefiles_object_jar, object);
+		return NULL;
+	}
+
 	refcount_set(&object->ref, 1);
 
 	spin_lock_init(&object->lock);
@@ -88,7 +93,7 @@  void cachefiles_put_object(struct cachefiles_object *object,
 		ASSERTCMP(object->file, ==, NULL);
 
 		kfree(object->d_name);
-
+		cachefiles_ondemand_deinit_obj_info(object);
 		cache = object->volume->cache->cache;
 		fscache_put_cookie(object->cookie, fscache_cookie_put_object);
 		object->cookie = NULL;
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index 00beedeaec183..b0fe76964bc0d 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -49,6 +49,12 @@  enum cachefiles_object_state {
 	CACHEFILES_ONDEMAND_OBJSTATE_OPEN, /* Anonymous fd associated with object is available */
 };
 
+struct cachefiles_ondemand_info {
+	int				ondemand_id;
+	enum cachefiles_object_state	state;
+	struct cachefiles_object	*object;
+};
+
 /*
  * Backing file state.
  */
@@ -66,8 +72,7 @@  struct cachefiles_object {
 	unsigned long			flags;
 #define CACHEFILES_OBJECT_USING_TMPFILE	0		/* Have an unlinked tmpfile */
 #ifdef CONFIG_CACHEFILES_ONDEMAND
-	int				ondemand_id;
-	enum cachefiles_object_state	state;
+	struct cachefiles_ondemand_info	*ondemand;
 #endif
 };
 
@@ -302,17 +307,21 @@  extern void cachefiles_ondemand_clean_object(struct cachefiles_object *object);
 extern int cachefiles_ondemand_read(struct cachefiles_object *object,
 				    loff_t pos, size_t len);
 
+extern int cachefiles_ondemand_init_obj_info(struct cachefiles_object *obj,
+					struct cachefiles_volume *volume);
+extern void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *obj);
+
 #define CACHEFILES_OBJECT_STATE_FUNCS(_state, _STATE)	\
 static inline bool								\
 cachefiles_ondemand_object_is_##_state(const struct cachefiles_object *object) \
 {												\
-	return object->state == CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
+	return object->ondemand->state == CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
 }												\
 												\
 static inline void								\
 cachefiles_ondemand_set_object_##_state(struct cachefiles_object *object) \
 {												\
-	object->state = CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
+	object->ondemand->state = CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
 }
 
 CACHEFILES_OBJECT_STATE_FUNCS(open, OPEN);
@@ -338,6 +347,15 @@  static inline int cachefiles_ondemand_read(struct cachefiles_object *object,
 {
 	return -EOPNOTSUPP;
 }
+
+static inline int cachefiles_ondemand_init_obj_info(struct cachefiles_object *obj,
+						struct cachefiles_volume *volume)
+{
+	return 0;
+}
+static inline void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *obj)
+{
+}
 #endif
 
 /*
diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c
index 90456b8a4b3e0..deb7e3007aa1d 100644
--- a/fs/cachefiles/ondemand.c
+++ b/fs/cachefiles/ondemand.c
@@ -9,12 +9,13 @@  static int cachefiles_ondemand_fd_release(struct inode *inode,
 {
 	struct cachefiles_object *object = file->private_data;
 	struct cachefiles_cache *cache = object->volume->cache;
-	int object_id = object->ondemand_id;
+	struct cachefiles_ondemand_info *info = object->ondemand;
+	int object_id = info->ondemand_id;
 	struct cachefiles_req *req;
 	XA_STATE(xas, &cache->reqs, 0);
 
 	xa_lock(&cache->reqs);
-	object->ondemand_id = CACHEFILES_ONDEMAND_ID_CLOSED;
+	info->ondemand_id = CACHEFILES_ONDEMAND_ID_CLOSED;
 	cachefiles_ondemand_set_object_close(object);
 
 	/*
@@ -222,7 +223,7 @@  static int cachefiles_ondemand_get_fd(struct cachefiles_req *req)
 	load = (void *)req->msg.data;
 	load->fd = fd;
 	req->msg.object_id = object_id;
-	object->ondemand_id = object_id;
+	object->ondemand->ondemand_id = object_id;
 
 	cachefiles_get_unbind_pincount(cache);
 	trace_cachefiles_ondemand_open(object, &req->msg, load);
@@ -368,7 +369,7 @@  static int cachefiles_ondemand_send_req(struct cachefiles_object *object,
 
 		if (opcode != CACHEFILES_OP_OPEN &&
 			!cachefiles_ondemand_object_is_open(object)) {
-			WARN_ON_ONCE(object->ondemand_id == 0);
+			WARN_ON_ONCE(object->ondemand->ondemand_id == 0);
 			xas_unlock(&xas);
 			ret = -EIO;
 			goto out;
@@ -438,7 +439,7 @@  static int cachefiles_ondemand_init_close_req(struct cachefiles_req *req,
 	if (!cachefiles_ondemand_object_is_open(object))
 		return -ENOENT;
 
-	req->msg.object_id = object->ondemand_id;
+	req->msg.object_id = object->ondemand->ondemand_id;
 	trace_cachefiles_ondemand_close(object, &req->msg);
 	return 0;
 }
@@ -454,7 +455,7 @@  static int cachefiles_ondemand_init_read_req(struct cachefiles_req *req,
 	struct cachefiles_object *object = req->object;
 	struct cachefiles_read *load = (void *)req->msg.data;
 	struct cachefiles_read_ctx *read_ctx = private;
-	int object_id = object->ondemand_id;
+	int object_id = object->ondemand->ondemand_id;
 
 	/* Stop enqueuing requests when daemon has closed anon_fd. */
 	if (!cachefiles_ondemand_object_is_open(object)) {
@@ -500,6 +501,27 @@  void cachefiles_ondemand_clean_object(struct cachefiles_object *object)
 			cachefiles_ondemand_init_close_req, NULL);
 }
 
+int cachefiles_ondemand_init_obj_info(struct cachefiles_object *object,
+				struct cachefiles_volume *volume)
+{
+	if (!cachefiles_in_ondemand_mode(volume->cache))
+		return 0;
+
+	object->ondemand = kzalloc(sizeof(struct cachefiles_ondemand_info),
+					GFP_KERNEL);
+	if (!object->ondemand)
+		return -ENOMEM;
+
+	object->ondemand->object = object;
+	return 0;
+}
+
+void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *object)
+{
+	kfree(object->ondemand);
+	object->ondemand = NULL;
+}
+
 int cachefiles_ondemand_read(struct cachefiles_object *object,
 			     loff_t pos, size_t len)
 {