Commit 9759bd51 authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

fuse: add memory barrier to INIT 



Theoretically we need to order setting of various fields in fc with
fc->initialized.

No known bug reports related to this yet.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
parent 21f62174

fs/fuse/dev.c

+13 −2
Original line number Diff line number Diff line
@@ -131,6 +131,13 @@ static void fuse_req_init_context(struct fuse_req *req) 
	req->in.h.pid = current->pid;

}



void fuse_set_initialized(struct fuse_conn *fc)

{

	/* Make sure stores before this are seen on another CPU */

	smp_wmb();

	fc->initialized = 1;

}



static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)

{

	return !fc->initialized || (for_background && fc->blocked);
@@ -155,6 +162,8 @@ static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages, 
		if (intr)

			goto out;

	}

	/* Matches smp_wmb() in fuse_set_initialized() */

	smp_rmb();



	err = -ENOTCONN;

	if (!fc->connected)
@@ -253,6 +262,8 @@ struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc, 


	atomic_inc(&fc->num_waiting);

	wait_event(fc->blocked_waitq, fc->initialized);

	/* Matches smp_wmb() in fuse_set_initialized() */

	smp_rmb();

	req = fuse_request_alloc(0);

	if (!req)

		req = get_reserved_req(fc, file);
@@ -2163,7 +2174,7 @@ void fuse_abort_conn(struct fuse_conn *fc) 
	if (fc->connected) {

		fc->connected = 0;

		fc->blocked = 0;

		fc->initialized = 1;

		fuse_set_initialized(fc);

		end_io_requests(fc);

		end_queued_requests(fc);

		end_polls(fc);
@@ -2182,7 +2193,7 @@ int fuse_dev_release(struct inode *inode, struct file *file) 
		spin_lock(&fc->lock);

		fc->connected = 0;

		fc->blocked = 0;

		fc->initialized = 1;

		fuse_set_initialized(fc);

		end_queued_requests(fc);

		end_polls(fc);

		wake_up_all(&fc->blocked_waitq);

fs/fuse/fuse_i.h

+2 −0
Original line number Diff line number Diff line
@@ -906,4 +906,6 @@ int fuse_write_inode(struct inode *inode, struct writeback_control *wbc); 
int fuse_do_setattr(struct inode *inode, struct iattr *attr,

		    struct file *file);



void fuse_set_initialized(struct fuse_conn *fc);



#endif /* _FS_FUSE_I_H */

fs/fuse/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -897,7 +897,7 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) 
		fc->max_write = max_t(unsigned, 4096, fc->max_write);

		fc->conn_init = 1;

	}

	fc->initialized = 1;

	fuse_set_initialized(fc);

	wake_up_all(&fc->blocked_waitq);

}