Unverified Commit 357a18d0 authored by Jia Zhu's avatar Jia Zhu Committed by Christian Brauner
Browse files

cachefiles: introduce object ondemand state 



Previously, @ondemand_id field was used not only to identify ondemand
state of the object, but also to represent the index of the xarray.
This commit introduces @state field to decouple the role of @ondemand_id
and adds helpers to access it.

Signed-off-by: default avatarJia Zhu <zhujia.zj@bytedance.com>
Link: https://lore.kernel.org/r/20231120041422.75170-2-zhujia.zj@bytedance.com


Reviewed-by: default avatarJingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent b85ea95d

fs/cachefiles/internal.h

+21 −0
Original line number Diff line number Diff line
@@ -44,6 +44,11 @@ struct cachefiles_volume { 
	struct dentry			*fanout[256];	/* Fanout subdirs */

};



enum cachefiles_object_state {

	CACHEFILES_ONDEMAND_OBJSTATE_CLOSE, /* Anonymous fd closed by daemon or initial state */

	CACHEFILES_ONDEMAND_OBJSTATE_OPEN, /* Anonymous fd associated with object is available */

};



/*

 * Backing file state.

 */
@@ -62,6 +67,7 @@ struct cachefiles_object { 
#define CACHEFILES_OBJECT_USING_TMPFILE	0		/* Have an unlinked tmpfile */

#ifdef CONFIG_CACHEFILES_ONDEMAND

	int				ondemand_id;

	enum cachefiles_object_state	state;

#endif

};
@@ -296,6 +302,21 @@ 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);



#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; \

}												\

												\

static inline void								\

cachefiles_ondemand_set_object_##_state(struct cachefiles_object *object) \

{												\

	object->state = CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \

}



CACHEFILES_OBJECT_STATE_FUNCS(open, OPEN);

CACHEFILES_OBJECT_STATE_FUNCS(close, CLOSE);

#else

static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,

					char __user *_buffer, size_t buflen)

fs/cachefiles/ondemand.c

+9 −12
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ static int cachefiles_ondemand_fd_release(struct inode *inode, 


	xa_lock(&cache->reqs);

	object->ondemand_id = CACHEFILES_ONDEMAND_ID_CLOSED;

	cachefiles_ondemand_set_object_close(object);



	/*

	 * Flush all pending READ requests since their completion depends on
@@ -176,6 +177,8 @@ int cachefiles_ondemand_copen(struct cachefiles_cache *cache, char *args) 
		set_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags);

	trace_cachefiles_ondemand_copen(req->object, id, size);



	cachefiles_ondemand_set_object_open(req->object);



out:

	complete(&req->done);

	return ret;
@@ -363,7 +366,8 @@ static int cachefiles_ondemand_send_req(struct cachefiles_object *object, 
		/* coupled with the barrier in cachefiles_flush_reqs() */

		smp_mb();



		if (opcode != CACHEFILES_OP_OPEN && object->ondemand_id <= 0) {

		if (opcode != CACHEFILES_OP_OPEN &&

			!cachefiles_ondemand_object_is_open(object)) {

			WARN_ON_ONCE(object->ondemand_id == 0);

			xas_unlock(&xas);

			ret = -EIO;
@@ -430,18 +434,11 @@ static int cachefiles_ondemand_init_close_req(struct cachefiles_req *req, 
					      void *private)

{

	struct cachefiles_object *object = req->object;

	int object_id = object->ondemand_id;



	/*

	 * It's possible that object id is still 0 if the cookie looking up

	 * phase failed before OPEN request has ever been sent. Also avoid

	 * sending CLOSE request for CACHEFILES_ONDEMAND_ID_CLOSED, which means

	 * anon_fd has already been closed.

	 */

	if (object_id <= 0)

	if (!cachefiles_ondemand_object_is_open(object))

		return -ENOENT;



	req->msg.object_id = object_id;

	req->msg.object_id = object->ondemand_id;

	trace_cachefiles_ondemand_close(object, &req->msg);

	return 0;

}
@@ -460,7 +457,7 @@ static int cachefiles_ondemand_init_read_req(struct cachefiles_req *req, 
	int object_id = object->ondemand_id;



	/* Stop enqueuing requests when daemon has closed anon_fd. */

	if (object_id <= 0) {

	if (!cachefiles_ondemand_object_is_open(object)) {

		WARN_ON_ONCE(object_id == 0);

		pr_info_once("READ: anonymous fd closed prematurely.\n");

		return -EIO;
@@ -485,7 +482,7 @@ int cachefiles_ondemand_init_object(struct cachefiles_object *object) 
	 * creating a new tmpfile as the cache file. Reuse the previously

	 * allocated object ID if any.

	 */

	if (object->ondemand_id > 0)

	if (cachefiles_ondemand_object_is_open(object))

		return 0;



	volume_key_size = volume->key[0] + 1;