linux-kernel - [PATCH 45/52] virtio: Free fuse devices on umount

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Message-Id: <20181210171318.16998-46-vgoyal@redhat.com>
Date:   Mon, 10 Dec 2018 12:13:11 -0500
From:   Vivek Goyal <vgoyal@...hat.com>
To:     linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org
Cc:     vgoyal@...hat.com, miklos@...redi.hu, stefanha@...hat.com,
        dgilbert@...hat.com, sweil@...hat.com, swhiteho@...hat.com
Subject: [PATCH 45/52] virtio: Free fuse devices on umount

From: "Dr. David Alan Gilbert" <dgilbert@...hat.com>

When unmounting the fs close all the fuse devices.
This includes making sure the daemon gets a FUSE_DESTROY to
tell it.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@...hat.com>
---
 fs/fuse/fuse_i.h    |  1 +
 fs/fuse/inode.c     |  3 ++-
 fs/fuse/virtio_fs.c | 13 ++++++++++++-
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 7b2db87c6ead..30c7b4b56200 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -85,6 +85,7 @@ struct fuse_mount_data {
 	unsigned default_permissions:1;
 	unsigned allow_other:1;
 	unsigned dax:1;
+	unsigned destroy:1;
 	unsigned max_read;
 	unsigned blksize;
 
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 178ac3171564..4d2d623e607f 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1263,7 +1263,7 @@ int fuse_fill_super_common(struct super_block *sb,
 		goto err_put_root;
 	__set_bit(FR_BACKGROUND, &init_req->flags);
 
-	if (is_bdev) {
+	if (mount_data->destroy) {
 		fc->destroy_req = fuse_request_alloc(0);
 		if (!fc->destroy_req)
 			goto err_free_init_req;
@@ -1339,6 +1339,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 	d.fiq_ops = &fuse_dev_fiq_ops;
 	d.fiq_priv = NULL;
 	d.fudptr = &file->private_data;
+	d.destroy = is_bdev;
 	err = fuse_fill_super_common(sb, &d);
 
 err_fput:
diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index f436f5b3f85c..c71bc47395b4 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -1128,6 +1128,7 @@ static int virtio_fs_fill_super(struct super_block *sb, void *data,
 	d.fiq_ops = &virtio_fs_fiq_ops;
 	d.fiq_priv = fs;
 	d.fudptr = (void **)&fs->vqs[2].fud;
+	d.destroy = true; /* Send destroy request on unmount */
 	err = fuse_fill_super_common(sb, &d);
 
 	if (err < 0)
@@ -1160,6 +1161,16 @@ static int virtio_fs_fill_super(struct super_block *sb, void *data,
 	return err;
 }
 
+static void virtio_kill_sb(struct super_block *sb)
+{
+	struct fuse_conn *fc = get_fuse_conn_super(sb);
+	fuse_kill_sb_anon(sb);
+	if (fc) {
+		struct virtio_fs *vfs = fc->iq.priv;
+		virtio_fs_free_devs(vfs);
+	}
+}
+
 static struct dentry *virtio_fs_mount(struct file_system_type *fs_type,
 				      int flags, const char *dev_name,
 				      void *raw_data)
@@ -1171,7 +1182,7 @@ static struct file_system_type virtio_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= KBUILD_MODNAME,
 	.mount		= virtio_fs_mount,
-	.kill_sb	= fuse_kill_sb_anon,
+	.kill_sb	= virtio_kill_sb,
 };
 
 static int __init virtio_fs_init(void)
-- 
2.13.6