[PATCH v4 1/6] vduse: make domain_lock an rwlock
From: Eugenio Pérez <eperezma@redhat.com>
Date: 2025-09-25 09:13:51
Also in:
lkml
Subsystem:
the rest, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
It will be used in a few more scenarios read-only so make it more scalable. Suggested-by: Xie Yongji <redacted> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Xie Yongji <redacted> Signed-off-by: Eugenio Pérez <eperezma@redhat.com> --- v2: New in v2 --- drivers/vdpa/vdpa_user/vduse_dev.c | 41 +++++++++++++++--------------- 1 file changed, 21 insertions(+), 20 deletions(-)
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index e7bced0b5542..2b6a8958ffe0 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c@@ -14,6 +14,7 @@ #include <linux/cdev.h> #include <linux/device.h> #include <linux/eventfd.h> +#include <linux/rwlock.h> #include <linux/slab.h> #include <linux/wait.h> #include <linux/dma-map-ops.h>
@@ -117,7 +118,7 @@ struct vduse_dev { struct vduse_umem *umem; struct mutex mem_lock; unsigned int bounce_size; - struct mutex domain_lock; + rwlock_t domain_lock; }; struct vduse_dev_msg {
@@ -1176,9 +1177,9 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd, if (entry.start > entry.last) break; - mutex_lock(&dev->domain_lock); + read_lock(&dev->domain_lock); if (!dev->domain) { - mutex_unlock(&dev->domain_lock); + read_unlock(&dev->domain_lock); break; } spin_lock(&dev->domain->iotlb_lock);
@@ -1193,7 +1194,7 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd, entry.perm = map->perm; } spin_unlock(&dev->domain->iotlb_lock); - mutex_unlock(&dev->domain_lock); + read_unlock(&dev->domain_lock); ret = -EINVAL; if (!f) break;
@@ -1346,10 +1347,10 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd, sizeof(umem.reserved))) break; - mutex_lock(&dev->domain_lock); + write_lock(&dev->domain_lock); ret = vduse_dev_reg_umem(dev, umem.iova, umem.uaddr, umem.size); - mutex_unlock(&dev->domain_lock); + write_unlock(&dev->domain_lock); break; } case VDUSE_IOTLB_DEREG_UMEM: {
@@ -1363,10 +1364,10 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd, if (!is_mem_zero((const char *)umem.reserved, sizeof(umem.reserved))) break; - mutex_lock(&dev->domain_lock); + write_lock(&dev->domain_lock); ret = vduse_dev_dereg_umem(dev, umem.iova, umem.size); - mutex_unlock(&dev->domain_lock); + write_unlock(&dev->domain_lock); break; } case VDUSE_IOTLB_GET_INFO: {
@@ -1385,9 +1386,9 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd, sizeof(info.reserved))) break; - mutex_lock(&dev->domain_lock); + read_lock(&dev->domain_lock); if (!dev->domain) { - mutex_unlock(&dev->domain_lock); + read_unlock(&dev->domain_lock); break; } spin_lock(&dev->domain->iotlb_lock);
@@ -1402,7 +1403,7 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd, info.capability |= VDUSE_IOVA_CAP_UMEM; } spin_unlock(&dev->domain->iotlb_lock); - mutex_unlock(&dev->domain_lock); + read_unlock(&dev->domain_lock); if (!map) break;
@@ -1425,10 +1426,10 @@ static int vduse_dev_release(struct inode *inode, struct file *file) { struct vduse_dev *dev = file->private_data; - mutex_lock(&dev->domain_lock); + write_lock(&dev->domain_lock); if (dev->domain) vduse_dev_dereg_umem(dev, 0, dev->domain->bounce_size); - mutex_unlock(&dev->domain_lock); + write_unlock(&dev->domain_lock); spin_lock(&dev->msg_lock); /* Make sure the inflight messages can processed after reconncection */ list_splice_init(&dev->recv_list, &dev->send_list);
@@ -1647,7 +1648,7 @@ static struct vduse_dev *vduse_dev_create(void) mutex_init(&dev->lock); mutex_init(&dev->mem_lock); - mutex_init(&dev->domain_lock); + rwlock_init(&dev->domain_lock); spin_lock_init(&dev->msg_lock); INIT_LIST_HEAD(&dev->send_list); INIT_LIST_HEAD(&dev->recv_list);
@@ -1805,7 +1806,7 @@ static ssize_t bounce_size_store(struct device *device, int ret; ret = -EPERM; - mutex_lock(&dev->domain_lock); + write_lock(&dev->domain_lock); if (dev->domain) goto unlock;
@@ -1821,7 +1822,7 @@ static ssize_t bounce_size_store(struct device *device, dev->bounce_size = bounce_size & PAGE_MASK; ret = count; unlock: - mutex_unlock(&dev->domain_lock); + write_unlock(&dev->domain_lock); return ret; }
@@ -2045,11 +2046,11 @@ static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name, if (ret) return ret; - mutex_lock(&dev->domain_lock); + write_lock(&dev->domain_lock); if (!dev->domain) dev->domain = vduse_domain_create(VDUSE_IOVA_SIZE - 1, dev->bounce_size); - mutex_unlock(&dev->domain_lock); + write_unlock(&dev->domain_lock); if (!dev->domain) { put_device(&dev->vdev->vdpa.dev); return -ENOMEM;
@@ -2059,10 +2060,10 @@ static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name, ret = _vdpa_register_device(&dev->vdev->vdpa, dev->vq_num); if (ret) { put_device(&dev->vdev->vdpa.dev); - mutex_lock(&dev->domain_lock); + write_lock(&dev->domain_lock); vduse_domain_destroy(dev->domain); dev->domain = NULL; - mutex_unlock(&dev->domain_lock); + write_unlock(&dev->domain_lock); return ret; }
--
2.51.0