diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-fs-virtiofs | 11 | ||||
| -rw-r--r-- | fs/fuse/virtio_fs.c | 112 |
2 files changed, 101 insertions, 22 deletions
diff --git a/Documentation/ABI/testing/sysfs-fs-virtiofs b/Documentation/ABI/testing/sysfs-fs-virtiofs new file mode 100644 index 000000000000..4839dbce997e --- /dev/null +++ b/Documentation/ABI/testing/sysfs-fs-virtiofs @@ -0,0 +1,11 @@ +What: /sys/fs/virtiofs/<n>/tag +Date: Feb 2024 +Contact: virtio-fs@lists.linux.dev +Description: + [RO] The mount "tag" that can be used to mount this filesystem. + +What: /sys/fs/virtiofs/<n>/device +Date: Feb 2024 +Contact: virtio-fs@lists.linux.dev +Description: + Symlink to the virtio device that exports this filesystem. diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c index d84dacbdce2c..99b6113bbd13 100644 --- a/fs/fuse/virtio_fs.c +++ b/fs/fuse/virtio_fs.c @@ -31,6 +31,9 @@ static DEFINE_MUTEX(virtio_fs_mutex); static LIST_HEAD(virtio_fs_instances); +/* The /sys/fs/virtio_fs/ kset */ +static struct kset *virtio_fs_kset; + enum { VQ_HIPRIO, VQ_REQUEST @@ -55,7 +58,7 @@ struct virtio_fs_vq { /* A virtio-fs device instance */ struct virtio_fs { - struct kref refcount; + struct kobject kobj; struct list_head list; /* on virtio_fs_instances */ char *tag; struct virtio_fs_vq *vqs; @@ -161,18 +164,40 @@ static inline void dec_in_flight_req(struct virtio_fs_vq *fsvq) complete(&fsvq->in_flight_zero); } -static void release_virtio_fs_obj(struct kref *ref) +static ssize_t tag_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + struct virtio_fs *fs = container_of(kobj, struct virtio_fs, kobj); + + return sysfs_emit(buf, fs->tag); +} + +static struct kobj_attribute virtio_fs_tag_attr = __ATTR_RO(tag); + +static struct attribute *virtio_fs_attrs[] = { + &virtio_fs_tag_attr.attr, + NULL +}; +ATTRIBUTE_GROUPS(virtio_fs); + +static void virtio_fs_ktype_release(struct kobject *kobj) { - struct virtio_fs *vfs = container_of(ref, struct virtio_fs, refcount); + struct virtio_fs *vfs = container_of(kobj, struct virtio_fs, kobj); kfree(vfs->vqs); kfree(vfs); } +static const struct kobj_type virtio_fs_ktype = { + .release = virtio_fs_ktype_release, + .sysfs_ops = &kobj_sysfs_ops, + .default_groups = virtio_fs_groups, +}; + /* Make sure virtiofs_mutex is held */ static void virtio_fs_put(struct virtio_fs *fs) { - kref_put(&fs->refcount, release_virtio_fs_obj); + kobject_put(&fs->kobj); } static void virtio_fs_fiq_release(struct fuse_iqueue *fiq) @@ -243,25 +268,44 @@ static void virtio_fs_start_all_queues(struct virtio_fs *fs) } /* Add a new instance to the list or return -EEXIST if tag name exists*/ -static int virtio_fs_add_instance(struct virtio_fs *fs) +static int virtio_fs_add_instance(struct virtio_device *vdev, + struct virtio_fs *fs) { struct virtio_fs *fs2; - bool duplicate = false; + int ret; mutex_lock(&virtio_fs_mutex); list_for_each_entry(fs2, &virtio_fs_instances, list) { - if (strcmp(fs->tag, fs2->tag) == 0) - duplicate = true; + if (strcmp(fs->tag, fs2->tag) == 0) { + mutex_unlock(&virtio_fs_mutex); + return -EEXIST; + } + } + + /* Use the virtio_device's index as a unique identifier, there is no + * need to allocate our own identifiers because the virtio_fs instance + * is only visible to userspace as long as the underlying virtio_device + * exists. + */ + fs->kobj.kset = virtio_fs_kset; + ret = kobject_add(&fs->kobj, NULL, "%d", vdev->index); + if (ret < 0) { + mutex_unlock(&virtio_fs_mutex); + return ret; + } + + ret = sysfs_create_link(&fs->kobj, &vdev->dev.kobj, "device"); + if (ret < 0) { + kobject_del(&fs->kobj); + mutex_unlock(&virtio_fs_mutex); + return ret; } - if (!duplicate) - list_add_tail(&fs->list, &virtio_fs_instances); + list_add_tail(&fs->list, &virtio_fs_instances); mutex_unlock(&virtio_fs_mutex); - if (duplicate) - return -EEXIST; return 0; } @@ -274,7 +318,7 @@ static struct virtio_fs *virtio_fs_find_instance(const char *tag) list_for_each_entry(fs, &virtio_fs_instances, list) { if (strcmp(fs->tag, tag) == 0) { - kref_get(&fs->refcount); + kobject_get(&fs->kobj); goto found; } } @@ -875,7 +919,7 @@ static int virtio_fs_probe(struct virtio_device *vdev) fs = kzalloc(sizeof(*fs), GFP_KERNEL); if (!fs) return -ENOMEM; - kref_init(&fs->refcount); + kobject_init(&fs->kobj, &virtio_fs_ktype); vdev->priv = fs; ret = virtio_fs_read_tag(vdev, fs); @@ -897,7 +941,7 @@ static int virtio_fs_probe(struct virtio_device *vdev) */ virtio_device_ready(vdev); - ret = virtio_fs_add_instance(fs); + ret = virtio_fs_add_instance(vdev, fs); if (ret < 0) goto out_vqs; @@ -906,11 +950,10 @@ static int virtio_fs_probe(struct virtio_device *vdev) out_vqs: virtio_reset_device(vdev); virtio_fs_cleanup_vqs(vdev); - kfree(fs->vqs); out: vdev->priv = NULL; - kfree(fs); + kobject_put(&fs->kobj); return ret; } @@ -934,6 +977,8 @@ static void virtio_fs_remove(struct virtio_device *vdev) mutex_lock(&virtio_fs_mutex); /* This device is going away. No one should get new reference */ list_del_init(&fs->list); + sysfs_remove_link(&fs->kobj, "device"); + kobject_del(&fs->kobj); virtio_fs_stop_all_queues(fs); virtio_fs_drain_all_queues_locked(fs); virtio_reset_device(vdev); @@ -1520,21 +1565,43 @@ static struct file_system_type virtio_fs_type = { .kill_sb = virtio_kill_sb, }; +static int __init virtio_fs_sysfs_init(void) +{ + virtio_fs_kset = kset_create_and_add("virtiofs", NULL, fs_kobj); + if (!virtio_fs_kset) + return -ENOMEM; + return 0; +} + +static void __exit virtio_fs_sysfs_exit(void) +{ + kset_unregister(virtio_fs_kset); + virtio_fs_kset = NULL; +} + static int __init virtio_fs_init(void) { int ret; - ret = register_virtio_driver(&virtio_fs_driver); + ret = virtio_fs_sysfs_init(); if (ret < 0) return ret; + ret = register_virtio_driver(&virtio_fs_driver); + if (ret < 0) + goto sysfs_exit; + ret = register_filesystem(&virtio_fs_type); - if (ret < 0) { - unregister_virtio_driver(&virtio_fs_driver); - return ret; - } + if (ret < 0) + goto unregister_virtio_driver; return 0; + +unregister_virtio_driver: + unregister_virtio_driver(&virtio_fs_driver); +sysfs_exit: + virtio_fs_sysfs_exit(); + return ret; } module_init(virtio_fs_init); @@ -1542,6 +1609,7 @@ static void __exit virtio_fs_exit(void) { unregister_filesystem(&virtio_fs_type); unregister_virtio_driver(&virtio_fs_driver); + virtio_fs_sysfs_exit(); } module_exit(virtio_fs_exit); |