[dpdk-dev] [PATCH v3] bus/vdev: replace device list lock by a recursive one
Thomas Monjalon
thomas at monjalon.net
Tue May 22 13:37:27 CEST 2018
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 at intel.com>
Signed-off-by: Thomas Monjalon <thomas at monjalon.net>
---
v3: try recursive lock
WARNING: not yet tested!
---
drivers/bus/vdev/vdev.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)
diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
index 099b9ff85..6139dd551 100644
--- 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;
}
--
2.16.2
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