From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: [PATCH v3] bus/vdev: replace device list lock by a recursive one Date: Tue, 22 May 2018 13:37:27 +0200 Message-ID: <20180522113727.3116-1-thomas@monjalon.net> References: <2833093.uzJjkH71XI@xps> Cc: matan@mellanox.com, ferruh.yigit@intel.com, anatoly.burakov@intel.com, gaetan.rivet@6wind.com To: dev@dpdk.org Return-path: Received: from out1-smtp.messagingengine.com (out1-smtp.messagingengine.com [66.111.4.25]) by dpdk.org (Postfix) with ESMTP id 0D2062BF2 for ; Tue, 22 May 2018 13:37:34 +0200 (CEST) In-Reply-To: <2833093.uzJjkH71XI@xps> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 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 Signed-off-by: Thomas Monjalon --- 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