Commit dc00809a authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

fuse: use per req lock for lock/unlock_request() 



Reuse req->waitq.lock for protecting FR_ABORTED and FR_LOCKED flags.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
Reviewed-by: default avatarAshish Samant <ashish.samant@oracle.com>
parent 825d6d33

fs/fuse/dev.c

+20 −22
Original line number Diff line number Diff line
@@ -656,16 +656,16 @@ void fuse_force_forget(struct file *file, u64 nodeid) 
 * anything that could cause a page-fault.  If the request was already

 * aborted bail out.

 */

static int lock_request(struct fuse_conn *fc, struct fuse_req *req)

static int lock_request(struct fuse_req *req)

{

	int err = 0;

	if (req) {

		spin_lock(&fc->lock);

		spin_lock(&req->waitq.lock);

		if (test_bit(FR_ABORTED, &req->flags))

			err = -ENOENT;

		else

			set_bit(FR_LOCKED, &req->flags);

		spin_unlock(&fc->lock);

		spin_unlock(&req->waitq.lock);

	}

	return err;

}
@@ -674,22 +674,21 @@ static int lock_request(struct fuse_conn *fc, struct fuse_req *req) 
 * Unlock request.  If it was aborted while locked, caller is responsible

 * for unlocking and ending the request.

 */

static int unlock_request(struct fuse_conn *fc, struct fuse_req *req)

static int unlock_request(struct fuse_req *req)

{

	int err = 0;

	if (req) {

		spin_lock(&fc->lock);

		spin_lock(&req->waitq.lock);

		if (test_bit(FR_ABORTED, &req->flags))

			err = -ENOENT;

		else

			clear_bit(FR_LOCKED, &req->flags);

		spin_unlock(&fc->lock);

		spin_unlock(&req->waitq.lock);

	}

	return err;

}



struct fuse_copy_state {

	struct fuse_conn *fc;

	int write;

	struct fuse_req *req;

	struct iov_iter *iter;
@@ -703,13 +702,10 @@ struct fuse_copy_state { 
	unsigned move_pages:1;

};



static void fuse_copy_init(struct fuse_copy_state *cs,

			   struct fuse_conn *fc,

			   int write,

static void fuse_copy_init(struct fuse_copy_state *cs, int write,

			   struct iov_iter *iter)

{

	memset(cs, 0, sizeof(*cs));

	cs->fc = fc;

	cs->write = write;

	cs->iter = iter;

}
@@ -742,7 +738,7 @@ static int fuse_copy_fill(struct fuse_copy_state *cs) 
	struct page *page;

	int err;



	err = unlock_request(cs->fc, cs->req);

	err = unlock_request(cs->req);

	if (err)

		return err;
@@ -794,7 +790,7 @@ static int fuse_copy_fill(struct fuse_copy_state *cs) 
		iov_iter_advance(cs->iter, err);

	}



	return lock_request(cs->fc, cs->req);

	return lock_request(cs->req);

}



/* Do as much copy to/from userspace buffer as we can */
@@ -845,7 +841,7 @@ static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep) 
	struct page *newpage;

	struct pipe_buffer *buf = cs->pipebufs;



	err = unlock_request(cs->fc, cs->req);

	err = unlock_request(cs->req);

	if (err)

		return err;
@@ -902,12 +898,12 @@ static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep) 
		lru_cache_add_file(newpage);



	err = 0;

	spin_lock(&cs->fc->lock);

	spin_lock(&cs->req->waitq.lock);

	if (test_bit(FR_ABORTED, &cs->req->flags))

		err = -ENOENT;

	else

		*pagep = newpage;

	spin_unlock(&cs->fc->lock);

	spin_unlock(&cs->req->waitq.lock);



	if (err) {

		unlock_page(newpage);
@@ -927,7 +923,7 @@ static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep) 
	cs->pg = buf->page;

	cs->offset = buf->offset;



	err = lock_request(cs->fc, cs->req);

	err = lock_request(cs->req);

	if (err)

		return err;
@@ -943,7 +939,7 @@ static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page, 
	if (cs->nr_segs == cs->pipe->buffers)

		return -EIO;



	err = unlock_request(cs->fc, cs->req);

	err = unlock_request(cs->req);

	if (err)

		return err;
@@ -1358,7 +1354,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to) 
	if (!iter_is_iovec(to))

		return -EINVAL;



	fuse_copy_init(&cs, fc, 1, to);

	fuse_copy_init(&cs, 1, to);



	return fuse_dev_do_read(fc, file, &cs, iov_iter_count(to));

}
@@ -1380,7 +1376,7 @@ static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos, 
	if (!bufs)

		return -ENOMEM;



	fuse_copy_init(&cs, fc, 1, NULL);

	fuse_copy_init(&cs, 1, NULL);

	cs.pipebufs = bufs;

	cs.pipe = pipe;

	ret = fuse_dev_do_read(fc, in, &cs, len);
@@ -1958,7 +1954,7 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from) 
	if (!iter_is_iovec(from))

		return -EINVAL;



	fuse_copy_init(&cs, fc, 0, from);

	fuse_copy_init(&cs, 0, from);



	return fuse_dev_do_write(fc, &cs, iov_iter_count(from));

}
@@ -2023,7 +2019,7 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe, 
	}

	pipe_unlock(pipe);



	fuse_copy_init(&cs, fc, 0, NULL);

	fuse_copy_init(&cs, 0, NULL);

	cs.pipebufs = bufs;

	cs.nr_segs = nbuf;

	cs.pipe = pipe;
@@ -2098,9 +2094,11 @@ __acquires(fc->lock) 


	list_for_each_entry_safe(req, next, &fc->io, list) {

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

		spin_lock(&req->waitq.lock);

		set_bit(FR_ABORTED, &req->flags);

		if (!test_bit(FR_LOCKED, &req->flags))

			list_move(&req->list, &to_end);

		spin_unlock(&req->waitq.lock);

	}

	while (!list_empty(&to_end)) {

		req = list_first_entry(&to_end, struct fuse_req, list);

fs/fuse/fuse_i.h

+4 −0
Original line number Diff line number Diff line
@@ -289,6 +289,10 @@ enum fuse_req_flag { 


/**

 * A request to the client

 *

 * .waitq.lock protects the following fields:

 *   - FR_ABORTED

 *   - FR_LOCKED (may also be modified under fc->lock, tested under both)

 */

struct fuse_req {

	/** This can be on either pending processing or io lists in