From f5adbfee72282bb1f456d52b04adacd4fe6ac502 Mon Sep 17 00:00:00 2001 From: Eran Ben Elisha Date: Thu, 12 Nov 2015 19:35:29 +0200 Subject: [PATCH] net/mlx4_core: Fix sleeping while holding spinlock at rem_slave_counters When cleaning slave's counter resources, we hold a spinlock that protects the slave's counters list. As part of the clean, we call __mlx4_clear_if_stat which calls mlx4_alloc_cmd_mailbox which is a sleepable function. In order to fix this issue, hold the spinlock, and copy all counter indices into a temporary array, and release the spinlock. Afterwards, iterate over this array and free every counter. Repeat this scenario until the original list is empty (a new counter might have been added while releasing the counters from the temporary array). Fixes: b72ca7e96acf ("net/mlx4_core: Reset counters data when freed") Reported-by: Moni Shoua Tested-by: Moni Shoua Signed-off-by: Jack Morgenstein Signed-off-by: Eran Ben Elisha Signed-off-by: Or Gerlitz Signed-off-by: David S. Miller --- .../ethernet/mellanox/mlx4/resource_tracker.c | 39 +++++++++++++------ 1 file changed, 27 insertions(+), 12 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c index 9813d34f3e5b..6fec3e993d02 100644 --- a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c +++ b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c @@ -4952,26 +4952,41 @@ static void rem_slave_counters(struct mlx4_dev *dev, int slave) struct res_counter *counter; struct res_counter *tmp; int err; - int index; + int *counters_arr = NULL; + int i, j; err = move_all_busy(dev, slave, RES_COUNTER); if (err) mlx4_warn(dev, "rem_slave_counters: Could not move all counters - too busy for slave %d\n", slave); - spin_lock_irq(mlx4_tlock(dev)); - list_for_each_entry_safe(counter, tmp, counter_list, com.list) { - if (counter->com.owner == slave) { - index = counter->com.res_id; - rb_erase(&counter->com.node, - &tracker->res_tree[RES_COUNTER]); - list_del(&counter->com.list); - kfree(counter); - __mlx4_counter_free(dev, index); + counters_arr = kmalloc_array(dev->caps.max_counters, + sizeof(*counters_arr), GFP_KERNEL); + if (!counters_arr) + return; + + do { + i = 0; + j = 0; + spin_lock_irq(mlx4_tlock(dev)); + list_for_each_entry_safe(counter, tmp, counter_list, com.list) { + if (counter->com.owner == slave) { + counters_arr[i++] = counter->com.res_id; + rb_erase(&counter->com.node, + &tracker->res_tree[RES_COUNTER]); + list_del(&counter->com.list); + kfree(counter); + } + } + spin_unlock_irq(mlx4_tlock(dev)); + + while (j < i) { + __mlx4_counter_free(dev, counters_arr[j++]); mlx4_release_resource(dev, slave, RES_COUNTER, 1, 0); } - } - spin_unlock_irq(mlx4_tlock(dev)); + } while (i); + + kfree(counters_arr); } static void rem_slave_xrcdns(struct mlx4_dev *dev, int slave)