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Commit cc080e9e authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

fuse: introduce per-instance fuse_dev structure 



Allow fuse device clones to refer to be distinguished.  This patch just
adds the infrastructure by associating a separate "struct fuse_dev" with
each clone.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
Reviewed-by: default avatarAshish Samant <ashish.samant@oracle.com>
parent 00c570f4

fs/fuse/cuse.c

+11 −3
Original line number Diff line number Diff line
@@ -489,6 +489,7 @@ static void cuse_fc_release(struct fuse_conn *fc) 
 */

static int cuse_channel_open(struct inode *inode, struct file *file)

{

	struct fuse_dev *fud;

	struct cuse_conn *cc;

	int rc;
@@ -499,16 +500,22 @@ static int cuse_channel_open(struct inode *inode, struct file *file) 


	fuse_conn_init(&cc->fc);



	fud = fuse_dev_alloc(&cc->fc);

	if (!fud) {

		kfree(cc);

		return -ENOMEM;

	}



	INIT_LIST_HEAD(&cc->list);

	cc->fc.release = cuse_fc_release;



	cc->fc.initialized = 1;

	rc = cuse_send_init(cc);

	if (rc) {

		fuse_conn_put(&cc->fc);

		fuse_dev_free(fud);

		return rc;

	}

	file->private_data = &cc->fc;	/* channel owns base reference to cc */

	file->private_data = fud;



	return 0;

}
@@ -526,7 +533,8 @@ static int cuse_channel_open(struct inode *inode, struct file *file) 
 */

static int cuse_channel_release(struct inode *inode, struct file *file)

{

	struct cuse_conn *cc = fc_to_cc(file->private_data);

	struct fuse_dev *fud = file->private_data;

	struct cuse_conn *cc = fc_to_cc(fud->fc);

	int rc;



	/* remove from the conntbl, no more access from this point on */

fs/fuse/dev.c

+42 −28
Original line number Diff line number Diff line
@@ -25,13 +25,13 @@ MODULE_ALIAS("devname:fuse"); 


static struct kmem_cache *fuse_req_cachep;



static struct fuse_conn *fuse_get_conn(struct file *file)

static struct fuse_dev *fuse_get_dev(struct file *file)

{

	/*

	 * Lockless access is OK, because file->private data is set

	 * once during mount and is valid until the file is released.

	 */

	return file->private_data;

	return ACCESS_ONCE(file->private_data);

}



static void fuse_request_init(struct fuse_req *req, struct page **pages,
@@ -1348,8 +1348,9 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to) 
{

	struct fuse_copy_state cs;

	struct file *file = iocb->ki_filp;

	struct fuse_conn *fc = fuse_get_conn(file);

	if (!fc)

	struct fuse_dev *fud = fuse_get_dev(file);



	if (!fud)

		return -EPERM;



	if (!iter_is_iovec(to))
@@ -1357,7 +1358,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to) 


	fuse_copy_init(&cs, 1, to);



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

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

}



static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
@@ -1369,8 +1370,9 @@ static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos, 
	int do_wakeup = 0;

	struct pipe_buffer *bufs;

	struct fuse_copy_state cs;

	struct fuse_conn *fc = fuse_get_conn(in);

	if (!fc)

	struct fuse_dev *fud = fuse_get_dev(in);



	if (!fud)

		return -EPERM;



	bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
@@ -1380,7 +1382,7 @@ static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos, 
	fuse_copy_init(&cs, 1, NULL);

	cs.pipebufs = bufs;

	cs.pipe = pipe;

	ret = fuse_dev_do_read(fc, in, &cs, len);

	ret = fuse_dev_do_read(fud->fc, in, &cs, len);

	if (ret < 0)

		goto out;
@@ -1954,8 +1956,9 @@ static ssize_t fuse_dev_do_write(struct fuse_conn *fc, 
static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from)

{

	struct fuse_copy_state cs;

	struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);

	if (!fc)

	struct fuse_dev *fud = fuse_get_dev(iocb->ki_filp);



	if (!fud)

		return -EPERM;



	if (!iter_is_iovec(from))
@@ -1963,7 +1966,7 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from) 


	fuse_copy_init(&cs, 0, from);



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

	return fuse_dev_do_write(fud->fc, &cs, iov_iter_count(from));

}



static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
@@ -1974,12 +1977,12 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe, 
	unsigned idx;

	struct pipe_buffer *bufs;

	struct fuse_copy_state cs;

	struct fuse_conn *fc;

	struct fuse_dev *fud;

	size_t rem;

	ssize_t ret;



	fc = fuse_get_conn(out);

	if (!fc)

	fud = fuse_get_dev(out);

	if (!fud)

		return -EPERM;



	bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
@@ -2034,7 +2037,7 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe, 
	if (flags & SPLICE_F_MOVE)

		cs.move_pages = 1;



	ret = fuse_dev_do_write(fc, &cs, len);

	ret = fuse_dev_do_write(fud->fc, &cs, len);



	for (idx = 0; idx < nbuf; idx++) {

		struct pipe_buffer *buf = &bufs[idx];
@@ -2049,11 +2052,12 @@ static unsigned fuse_dev_poll(struct file *file, poll_table *wait) 
{

	unsigned mask = POLLOUT | POLLWRNORM;

	struct fuse_iqueue *fiq;

	struct fuse_conn *fc = fuse_get_conn(file);

	if (!fc)

	struct fuse_dev *fud = fuse_get_dev(file);



	if (!fud)

		return POLLERR;



	fiq = &fc->iq;

	fiq = &fud->fc->iq;

	poll_wait(file, &fiq->waitq, wait);



	spin_lock(&fiq->waitq.lock);
@@ -2175,12 +2179,15 @@ EXPORT_SYMBOL_GPL(fuse_abort_conn); 


int fuse_dev_release(struct inode *inode, struct file *file)

{

	struct fuse_conn *fc = fuse_get_conn(file);

	if (fc) {

	struct fuse_dev *fud = fuse_get_dev(file);



	if (fud) {

		struct fuse_conn *fc = fud->fc;



		WARN_ON(!list_empty(&fc->pq.io));

		WARN_ON(fc->iq.fasync != NULL);

		fuse_abort_conn(fc);

		fuse_conn_put(fc);

		fuse_dev_free(fud);

	}



	return 0;
@@ -2189,20 +2196,27 @@ EXPORT_SYMBOL_GPL(fuse_dev_release); 


static int fuse_dev_fasync(int fd, struct file *file, int on)

{

	struct fuse_conn *fc = fuse_get_conn(file);

	if (!fc)

	struct fuse_dev *fud = fuse_get_dev(file);



	if (!fud)

		return -EPERM;



	/* No locking - fasync_helper does its own locking */

	return fasync_helper(fd, file, on, &fc->iq.fasync);

	return fasync_helper(fd, file, on, &fud->fc->iq.fasync);

}



static int fuse_device_clone(struct fuse_conn *fc, struct file *new)

{

	struct fuse_dev *fud;



	if (new->private_data)

		return -EINVAL;



	new->private_data = fuse_conn_get(fc);

	fud = fuse_dev_alloc(fc);

	if (!fud)

		return -ENOMEM;



	new->private_data = fud;



	return 0;

}
@@ -2221,11 +2235,11 @@ static long fuse_dev_ioctl(struct file *file, unsigned int cmd, 


			err = -EINVAL;

			if (old) {

				struct fuse_conn *fc = fuse_get_conn(old);

				struct fuse_dev *fud = fuse_get_dev(old);



				if (fc) {

				if (fud) {

					mutex_lock(&fuse_mutex);

					err = fuse_device_clone(fc, file);

					err = fuse_device_clone(fud->fc, file);

					mutex_unlock(&fuse_mutex);

				}

				fput(old);

fs/fuse/fuse_i.h

+17 −0
Original line number Diff line number Diff line
@@ -417,6 +417,17 @@ struct fuse_pqueue { 
	struct list_head io;

};



/**

 * Fuse device instance

 */

struct fuse_dev {

	/** Fuse connection for this device */

	struct fuse_conn *fc;



	/** list entry on fc->devices */

	struct list_head entry;

};



/**

 * A Fuse connection.

 *
@@ -629,6 +640,9 @@ struct fuse_conn { 


	/** Read/write semaphore to hold when accessing sb. */

	struct rw_semaphore killsb;



	/** List of device instances belonging to this connection */

	struct list_head devices;

};



static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
@@ -841,6 +855,9 @@ void fuse_conn_init(struct fuse_conn *fc); 
 */

void fuse_conn_put(struct fuse_conn *fc);



struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc);

void fuse_dev_free(struct fuse_dev *fud);



/**

 * Add connection to control filesystem

 */

fs/fuse/inode.c

+44 −3
Original line number Diff line number Diff line
@@ -598,6 +598,7 @@ void fuse_conn_init(struct fuse_conn *fc) 
	fuse_pqueue_init(&fc->pq);

	INIT_LIST_HEAD(&fc->bg_queue);

	INIT_LIST_HEAD(&fc->entry);

	INIT_LIST_HEAD(&fc->devices);

	atomic_set(&fc->num_waiting, 0);

	fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;

	fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
@@ -945,6 +946,7 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req) 


static void fuse_free_conn(struct fuse_conn *fc)

{

	WARN_ON(!list_empty(&fc->devices));

	kfree_rcu(fc, rcu);

}
@@ -990,8 +992,41 @@ static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) 
	return 0;

}



struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc)

{

	struct fuse_dev *fud;



	fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);

	if (fud) {

		fud->fc = fuse_conn_get(fc);



		spin_lock(&fc->lock);

		list_add_tail(&fud->entry, &fc->devices);

		spin_unlock(&fc->lock);

	}



	return fud;

}

EXPORT_SYMBOL_GPL(fuse_dev_alloc);



void fuse_dev_free(struct fuse_dev *fud)

{

	struct fuse_conn *fc = fud->fc;



	if (fc) {

		spin_lock(&fc->lock);

		list_del(&fud->entry);

		spin_unlock(&fc->lock);



		fuse_conn_put(fc);

	}

	kfree(fud);

}

EXPORT_SYMBOL_GPL(fuse_dev_free);



static int fuse_fill_super(struct super_block *sb, void *data, int silent)

{

	struct fuse_dev *fud;

	struct fuse_conn *fc;

	struct inode *root;

	struct fuse_mount_data d;
@@ -1043,11 +1078,15 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) 
	fuse_conn_init(fc);

	fc->release = fuse_free_conn;



	fud = fuse_dev_alloc(fc);

	if (!fud)

		goto err_put_conn;



	fc->dev = sb->s_dev;

	fc->sb = sb;

	err = fuse_bdi_init(fc, sb);

	if (err)

		goto err_put_conn;

		goto err_dev_free;



	sb->s_bdi = &fc->bdi;
@@ -1068,7 +1107,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) 
	root = fuse_get_root_inode(sb, d.rootmode);

	root_dentry = d_make_root(root);

	if (!root_dentry)

		goto err_put_conn;

		goto err_dev_free;

	/* only now - we want root dentry with NULL ->d_op */

	sb->s_d_op = &fuse_dentry_operations;
@@ -1094,7 +1133,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) 


	list_add_tail(&fc->entry, &fuse_conn_list);

	sb->s_root = root_dentry;

	file->private_data = fuse_conn_get(fc);

	file->private_data = fud;

	mutex_unlock(&fuse_mutex);

	/*

	 * atomic_dec_and_test() in fput() provides the necessary
@@ -1113,6 +1152,8 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) 
	fuse_request_free(init_req);

 err_put_root:

	dput(root_dentry);

 err_dev_free:

	fuse_dev_free(fud);

 err_put_conn:

	fuse_bdi_destroy(fc);

	fuse_conn_put(fc);