diff --git a/Documentation/networking/netconsole.rst b/Documentation/networking/netconsole.rst index d55c2a22ec7a..94c4680fdf3e 100644 --- a/Documentation/networking/netconsole.rst +++ b/Documentation/networking/netconsole.rst @@ -124,7 +124,7 @@ To remove a target:: The interface exposes these parameters of a netconsole target to userspace: - ============== ================================= ============ + =============== ================================= ============ enabled Is this target currently enabled? (read-write) extended Extended mode enabled (read-write) release Prepend kernel release to message (read-write) @@ -135,7 +135,8 @@ The interface exposes these parameters of a netconsole target to userspace: remote_ip Remote agent's IP address (read-write) local_mac Local interface's MAC address (read-only) remote_mac Remote agent's MAC address (read-write) - ============== ================================= ============ + transmit_errors Number of packet send errors (read-only) + =============== ================================= ============ The "enabled" attribute is also used to control whether the parameters of a target can be updated or not -- you can modify the parameters of only diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index 4ea44a2f48f7..f422a2f666ef 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include @@ -90,6 +91,12 @@ static DEFINE_MUTEX(target_cleanup_list_lock); */ static struct console netconsole_ext; +struct netconsole_target_stats { + u64_stats_t xmit_drop_count; + u64_stats_t enomem_count; + struct u64_stats_sync syncp; +}; + /** * struct netconsole_target - Represents a configured netconsole target. * @list: Links this target into the target_list. @@ -97,6 +104,7 @@ static struct console netconsole_ext; * @userdata_group: Links to the userdata configfs hierarchy * @userdata_complete: Cached, formatted string of append * @userdata_length: String length of userdata_complete + * @stats: Packet send stats for the target. Used for debugging. * @enabled: On / off knob to enable / disable target. * Visible from userspace (read-write). * We maintain a strict 1:1 correspondence between this and @@ -124,6 +132,7 @@ struct netconsole_target { char userdata_complete[MAX_USERDATA_ENTRY_LENGTH * MAX_USERDATA_ITEMS]; size_t userdata_length; #endif + struct netconsole_target_stats stats; bool enabled; bool extended; bool release; @@ -262,6 +271,7 @@ static void netconsole_process_cleanups_core(void) * | remote_ip * | local_mac * | remote_mac + * | transmit_errors * | userdata/ * | / * | value @@ -371,6 +381,21 @@ static ssize_t remote_mac_show(struct config_item *item, char *buf) return sysfs_emit(buf, "%pM\n", to_target(item)->np.remote_mac); } +static ssize_t transmit_errors_show(struct config_item *item, char *buf) +{ + struct netconsole_target *nt = to_target(item); + u64 xmit_drop_count, enomem_count; + unsigned int start; + + do { + start = u64_stats_fetch_begin(&nt->stats.syncp); + xmit_drop_count = u64_stats_read(&nt->stats.xmit_drop_count); + enomem_count = u64_stats_read(&nt->stats.enomem_count); + } while (u64_stats_fetch_retry(&nt->stats.syncp, start)); + + return sysfs_emit(buf, "%llu\n", xmit_drop_count + enomem_count); +} + /* * This one is special -- targets created through the configfs interface * are not enabled (and the corresponding netpoll activated) by default. @@ -842,6 +867,7 @@ CONFIGFS_ATTR(, remote_ip); CONFIGFS_ATTR_RO(, local_mac); CONFIGFS_ATTR(, remote_mac); CONFIGFS_ATTR(, release); +CONFIGFS_ATTR_RO(, transmit_errors); static struct configfs_attribute *netconsole_target_attrs[] = { &attr_enabled, @@ -854,6 +880,7 @@ static struct configfs_attribute *netconsole_target_attrs[] = { &attr_remote_ip, &attr_local_mac, &attr_remote_mac, + &attr_transmit_errors, NULL, }; @@ -1058,6 +1085,33 @@ static struct notifier_block netconsole_netdev_notifier = { .notifier_call = netconsole_netdev_event, }; +/** + * send_udp - Wrapper for netpoll_send_udp that counts errors + * @nt: target to send message to + * @msg: message to send + * @len: length of message + * + * Calls netpoll_send_udp and classifies the return value. If an error + * occurred it increments statistics in nt->stats accordingly. + * Only calls netpoll_send_udp if CONFIG_NETCONSOLE_DYNAMIC is disabled. + */ +static void send_udp(struct netconsole_target *nt, const char *msg, int len) +{ + int result = netpoll_send_udp(&nt->np, msg, len); + + if (IS_ENABLED(CONFIG_NETCONSOLE_DYNAMIC)) { + if (result == NET_XMIT_DROP) { + u64_stats_update_begin(&nt->stats.syncp); + u64_stats_inc(&nt->stats.xmit_drop_count); + u64_stats_update_end(&nt->stats.syncp); + } else if (result == -ENOMEM) { + u64_stats_update_begin(&nt->stats.syncp); + u64_stats_inc(&nt->stats.enomem_count); + u64_stats_update_end(&nt->stats.syncp); + } + } +} + static void send_msg_no_fragmentation(struct netconsole_target *nt, const char *msg, int msg_len, @@ -1085,7 +1139,7 @@ static void send_msg_no_fragmentation(struct netconsole_target *nt, MAX_PRINT_CHUNK - msg_len, "%s", userdata); - netpoll_send_udp(&nt->np, buf, msg_len); + send_udp(nt, buf, msg_len); } static void append_release(char *buf) @@ -1178,7 +1232,7 @@ static void send_fragmented_body(struct netconsole_target *nt, char *buf, this_offset += this_chunk; } - netpoll_send_udp(&nt->np, buf, this_header + this_offset); + send_udp(nt, buf, this_header + this_offset); offset += this_offset; } } @@ -1288,7 +1342,7 @@ static void write_msg(struct console *con, const char *msg, unsigned int len) tmp = msg; for (left = len; left;) { frag = min(left, MAX_PRINT_CHUNK); - netpoll_send_udp(&nt->np, tmp, frag); + send_udp(nt, tmp, frag); tmp += frag; left -= frag; }