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| author |   Ido Schimmel <idosch@mellanox.com> | 2019-08-06 16:19:52 +0300 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-08-06 12:37:56 -0700 |
| commit | dbf896b70d4a4bdbd10aec060af42d7c70e6a88d (patch) | |
| tree | b28f66c37244f9557c70da8dff351c94f6b75512 /net/core/drop_monitor.c | |
| parent | drop_monitor: Use correct error code (diff) | |
| download | linux-dev-dbf896b70d4a4bdbd10aec060af42d7c70e6a88d.tar.xz linux-dev-dbf896b70d4a4bdbd10aec060af42d7c70e6a88d.zip | |
drop_monitor: Rename and document scope of mutex
The 'trace_state_mutex' does not only protect the global 'trace_state'
variable, but also the global 'hw_stats_list'.
Subsequent patches are going add more operations from user space to
drop_monitor and these all need to be mutually exclusive.
Rename 'trace_state_mutex' to the more fitting 'net_dm_mutex' name and
document its scope.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/drop_monitor.c')
| -rw-r--r-- | net/core/drop_monitor.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index dcb4d2aeb2a8..000ec8b66d1e 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -43,7 +43,13 @@ * netlink alerts */ static int trace_state = TRACE_OFF; -static DEFINE_MUTEX(trace_state_mutex); + +/* net_dm_mutex + * + * An overall lock guarding every operation coming from userspace. + * It also guards the global 'hw_stats_list' list. + */ +static DEFINE_MUTEX(net_dm_mutex); struct per_cpu_dm_data { spinlock_t lock; @@ -241,7 +247,7 @@ static int set_all_monitor_traces(int state) struct dm_hw_stat_delta *new_stat = NULL; struct dm_hw_stat_delta *temp; - mutex_lock(&trace_state_mutex); + mutex_lock(&net_dm_mutex); if (state == trace_state) { rc = -EAGAIN; @@ -289,7 +295,7 @@ static int set_all_monitor_traces(int state) rc = -EINPROGRESS; out_unlock: - mutex_unlock(&trace_state_mutex); + mutex_unlock(&net_dm_mutex); return rc; } @@ -330,12 +336,12 @@ static int dropmon_net_event(struct notifier_block *ev_block, new_stat->dev = dev; new_stat->last_rx = jiffies; - mutex_lock(&trace_state_mutex); + mutex_lock(&net_dm_mutex); list_add_rcu(&new_stat->list, &hw_stats_list); - mutex_unlock(&trace_state_mutex); + mutex_unlock(&net_dm_mutex); break; case NETDEV_UNREGISTER: - mutex_lock(&trace_state_mutex); + mutex_lock(&net_dm_mutex); list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) { if (new_stat->dev == dev) { new_stat->dev = NULL; @@ -346,7 +352,7 @@ static int dropmon_net_event(struct notifier_block *ev_block, } } } - mutex_unlock(&trace_state_mutex); + mutex_unlock(&net_dm_mutex); break; } out: |