bus/vdev: replace device list lock by a recursive one

A device like failsafe can manage sub-devices.
When removing such device, it removes its sub-devices
and try to take the same vdev_device_list_lock.
It was causing a deadlock because the lock was not recursive.

Fixes: 35f462839b69 ("bus/vdev: add lock on device list")

Suggested-by: Anatoly Burakov <anatoly.burakov@intel.com>
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Tested-by: Matan Azrad <matan@mellanox.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
index 099b9ff..6139dd5 100644 (file)
--- a/drivers/bus/vdev/vdev.c
+++ b/drivers/bus/vdev/vdev.c
@@ -36,7 +36,9 @@ TAILQ_HEAD(vdev_device_list, rte_vdev_device);
 
 static struct vdev_device_list vdev_device_list =
        TAILQ_HEAD_INITIALIZER(vdev_device_list);
-static rte_spinlock_t vdev_device_list_lock = RTE_SPINLOCK_INITIALIZER;
+/* The lock needs to be recursive because a vdev can manage another vdev. */
+static rte_spinlock_recursive_t vdev_device_list_lock =
+       RTE_SPINLOCK_RECURSIVE_INITIALIZER;
 
 struct vdev_driver_list vdev_driver_list =
        TAILQ_HEAD_INITIALIZER(vdev_driver_list);
@@ -249,7 +251,7 @@ rte_vdev_init(const char *name, const char *args)
        struct rte_devargs *devargs;
        int ret;
 
-       rte_spinlock_lock(&vdev_device_list_lock);
+       rte_spinlock_recursive_lock(&vdev_device_list_lock);
        ret = insert_vdev(name, args, &dev);
        if (ret == 0) {
                ret = vdev_probe_all_drivers(dev);
@@ -263,7 +265,7 @@ rte_vdev_init(const char *name, const char *args)
                        free(dev);
                }
        }
-       rte_spinlock_unlock(&vdev_device_list_lock);
+       rte_spinlock_recursive_unlock(&vdev_device_list_lock);
        return ret;
 }
 
@@ -293,7 +295,7 @@ rte_vdev_uninit(const char *name)
        if (name == NULL)
                return -EINVAL;
 
-       rte_spinlock_lock(&vdev_device_list_lock);
+       rte_spinlock_recursive_lock(&vdev_device_list_lock);
 
        dev = find_vdev(name);
        if (!dev) {
@@ -311,7 +313,7 @@ rte_vdev_uninit(const char *name)
        free(dev);
 
 unlock:
-       rte_spinlock_unlock(&vdev_device_list_lock);
+       rte_spinlock_recursive_unlock(&vdev_device_list_lock);
        return ret;
 }
 
@@ -355,7 +357,7 @@ vdev_action(const struct rte_mp_msg *mp_msg, const void *peer)
                ou->num = 1;
                num = 0;
 
-               rte_spinlock_lock(&vdev_device_list_lock);
+               rte_spinlock_recursive_lock(&vdev_device_list_lock);
                TAILQ_FOREACH(dev, &vdev_device_list, next) {
                        devname = rte_vdev_device_name(dev);
                        if (strlen(devname) == 0) {
@@ -369,7 +371,7 @@ vdev_action(const struct rte_mp_msg *mp_msg, const void *peer)
                                         devname, strerror(rte_errno));
                        num++;
                }
-               rte_spinlock_unlock(&vdev_device_list_lock);
+               rte_spinlock_recursive_unlock(&vdev_device_list_lock);
 
                ou->type = VDEV_SCAN_REP;
                ou->num = num;
@@ -445,10 +447,10 @@ vdev_scan(void)
                if (!dev)
                        return -1;
 
-               rte_spinlock_lock(&vdev_device_list_lock);
+               rte_spinlock_recursive_lock(&vdev_device_list_lock);
 
                if (find_vdev(devargs->name)) {
-                       rte_spinlock_unlock(&vdev_device_list_lock);
+                       rte_spinlock_recursive_unlock(&vdev_device_list_lock);
                        free(dev);
                        continue;
                }
@@ -459,7 +461,7 @@ vdev_scan(void)
 
                TAILQ_INSERT_TAIL(&vdev_device_list, dev, next);
 
-               rte_spinlock_unlock(&vdev_device_list_lock);
+               rte_spinlock_recursive_unlock(&vdev_device_list_lock);
        }
 
        return 0;
@@ -498,7 +500,7 @@ vdev_find_device(const struct rte_device *start, rte_dev_cmp_t cmp,
        const struct rte_vdev_device *vstart;
        struct rte_vdev_device *dev;
 
-       rte_spinlock_lock(&vdev_device_list_lock);
+       rte_spinlock_recursive_lock(&vdev_device_list_lock);
        if (start != NULL) {
                vstart = RTE_DEV_TO_VDEV_CONST(start);
                dev = TAILQ_NEXT(vstart, next);
@@ -510,7 +512,7 @@ vdev_find_device(const struct rte_device *start, rte_dev_cmp_t cmp,
                        break;
                dev = TAILQ_NEXT(dev, next);
        }
-       rte_spinlock_unlock(&vdev_device_list_lock);
+       rte_spinlock_recursive_unlock(&vdev_device_list_lock);
 
        return dev ? &dev->device : NULL;
 }