Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 63825b4e authored by Kirill Tkhai's avatar Kirill Tkhai Committed by Miklos Szeredi
Browse files

fuse: do not take fc->lock in fuse_request_send_background() 



Currently, we take fc->lock there only to check for fc->connected.
But this flag is changed only on connection abort, which is very
rare operation.

So allow checking fc->connected under just fc->bg_lock and use this lock
(as well as fc->lock) when resetting fc->connected.

Signed-off-by: default avatarKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent ae2dffa3

fs/fuse/dev.c

+24 −24
Original line number Diff line number Diff line
@@ -581,21 +581,18 @@ ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args) 
	return ret;

}



/*

 * Called under fc->lock

 *

 * fc->connected must have been checked previously

 */

void fuse_request_send_background_nocheck(struct fuse_conn *fc,

					  struct fuse_req *req)

bool fuse_request_queue_background(struct fuse_conn *fc, struct fuse_req *req)

{

	BUG_ON(!test_bit(FR_BACKGROUND, &req->flags));

	bool queued = false;



	WARN_ON(!test_bit(FR_BACKGROUND, &req->flags));

	if (!test_bit(FR_WAITING, &req->flags)) {

		__set_bit(FR_WAITING, &req->flags);

		atomic_inc(&fc->num_waiting);

	}

	__set_bit(FR_ISREPLY, &req->flags);

	spin_lock(&fc->bg_lock);

	if (likely(fc->connected)) {

		fc->num_background++;

		if (fc->num_background == fc->max_background)

			fc->blocked = 1;
@@ -605,18 +602,17 @@ void fuse_request_send_background_nocheck(struct fuse_conn *fc, 
		}

		list_add_tail(&req->list, &fc->bg_queue);

		flush_bg_queue(fc);

		queued = true;

	}

	spin_unlock(&fc->bg_lock);



	return queued;

}



void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)

{

	BUG_ON(!req->end);

	spin_lock(&fc->lock);

	if (fc->connected) {

		fuse_request_send_background_nocheck(fc, req);

		spin_unlock(&fc->lock);

	} else {

		spin_unlock(&fc->lock);

	WARN_ON(!req->end);

	if (!fuse_request_queue_background(fc, req)) {

		req->out.h.error = -ENOTCONN;

		req->end(fc, req);

		fuse_put_request(fc, req);
@@ -2119,7 +2115,11 @@ void fuse_abort_conn(struct fuse_conn *fc, bool is_abort) 
		struct fuse_req *req, *next;

		LIST_HEAD(to_end);



		/* Background queuing checks fc->connected under bg_lock */

		spin_lock(&fc->bg_lock);

		fc->connected = 0;

		spin_unlock(&fc->bg_lock);



		fc->aborted = is_abort;

		fuse_set_initialized(fc);

		list_for_each_entry(fud, &fc->devices, entry) {

fs/fuse/file.c

+3 −1
Original line number Diff line number Diff line
@@ -1487,6 +1487,7 @@ __acquires(fc->lock) 
	struct fuse_inode *fi = get_fuse_inode(req->inode);

	struct fuse_write_in *inarg = &req->misc.write.in;

	__u64 data_size = req->num_pages * PAGE_SIZE;

	bool queued;



	if (!fc->connected)

		goto out_free;
@@ -1502,7 +1503,8 @@ __acquires(fc->lock) 


	req->in.args[1].size = inarg->size;

	fi->writectr++;

	fuse_request_send_background_nocheck(fc, req);

	queued = fuse_request_queue_background(fc, req);

	WARN_ON(!queued);

	return;



 out_free:

fs/fuse/fuse_i.h

+1 −3
Original line number Diff line number Diff line
@@ -863,9 +863,7 @@ ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args); 
 * Send a request in the background

 */

void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);



void fuse_request_send_background_nocheck(struct fuse_conn *fc,

					  struct fuse_req *req);

bool fuse_request_queue_background(struct fuse_conn *fc, struct fuse_req *req);



/* Abort all requests */

void fuse_abort_conn(struct fuse_conn *fc, bool is_abort);