diff options
Diffstat (limited to 'drivers/net/netconsole.c')
| -rw-r--r-- | drivers/net/netconsole.c | 67 |
1 files changed, 58 insertions, 9 deletions
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index 4289ccd3e41b..21077aff061c 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -86,10 +86,10 @@ static DEFINE_SPINLOCK(target_list_lock); static DEFINE_MUTEX(target_cleanup_list_lock); /* - * Console driver for extended netconsoles. Registered on the first use to - * avoid unnecessarily enabling ext message formatting. + * Console driver for netconsoles. Register only consoles that have + * an associated target of the same type. */ -static struct console netconsole_ext; +static struct console netconsole_ext, netconsole; struct netconsole_target_stats { u64_stats_t xmit_drop_count; @@ -97,6 +97,11 @@ struct netconsole_target_stats { struct u64_stats_sync syncp; }; +enum console_type { + CONS_BASIC = BIT(0), + CONS_EXTENDED = BIT(1), +}; + /* Features enabled in sysdata. Contrary to userdata, this data is populated by * the kernel. The fields are designed as bitwise flags, allowing multiple * features to be set in sysdata_fields. @@ -455,6 +460,33 @@ static ssize_t sysdata_release_enabled_show(struct config_item *item, return sysfs_emit(buf, "%d\n", release_enabled); } +/* Iterate in the list of target, and make sure we don't have any console + * register without targets of the same type + */ +static void unregister_netcons_consoles(void) +{ + struct netconsole_target *nt; + u32 console_type_needed = 0; + unsigned long flags; + + spin_lock_irqsave(&target_list_lock, flags); + list_for_each_entry(nt, &target_list, list) { + if (nt->extended) + console_type_needed |= CONS_EXTENDED; + else + console_type_needed |= CONS_BASIC; + } + spin_unlock_irqrestore(&target_list_lock, flags); + + if (!(console_type_needed & CONS_EXTENDED) && + console_is_registered(&netconsole_ext)) + unregister_console(&netconsole_ext); + + if (!(console_type_needed & CONS_BASIC) && + console_is_registered(&netconsole)) + unregister_console(&netconsole); +} + /* * This one is special -- targets created through the configfs interface * are not enabled (and the corresponding netpoll activated) by default. @@ -488,8 +520,18 @@ static ssize_t enabled_store(struct config_item *item, goto out_unlock; } - if (nt->extended && !console_is_registered(&netconsole_ext)) + if (nt->extended && !console_is_registered(&netconsole_ext)) { + netconsole_ext.flags |= CON_ENABLED; register_console(&netconsole_ext); + } + + /* User might be enabling the basic format target for the very + * first time, make sure the console is registered. + */ + if (!nt->extended && !console_is_registered(&netconsole)) { + netconsole.flags |= CON_ENABLED; + register_console(&netconsole); + } /* * Skip netpoll_parse_options() -- all the attributes are @@ -517,6 +559,10 @@ static ssize_t enabled_store(struct config_item *item, list_move(&nt->list, &target_cleanup_list); spin_unlock_irqrestore(&target_list_lock, flags); mutex_unlock(&target_cleanup_list_lock); + /* Unregister consoles, whose the last target of that type got + * disabled. + */ + unregister_netcons_consoles(); } ret = strnlen(buf, count); @@ -1691,8 +1737,8 @@ static int __init init_netconsole(void) { int err; struct netconsole_target *nt, *tmp; + u32 console_type_needed = 0; unsigned int count = 0; - bool extended = false; unsigned long flags; char *target_config; char *input = config; @@ -1708,9 +1754,10 @@ static int __init init_netconsole(void) } /* Dump existing printks when we register */ if (nt->extended) { - extended = true; + console_type_needed |= CONS_EXTENDED; netconsole_ext.flags |= CON_PRINTBUFFER; } else { + console_type_needed |= CONS_BASIC; netconsole.flags |= CON_PRINTBUFFER; } @@ -1729,9 +1776,10 @@ static int __init init_netconsole(void) if (err) goto undonotifier; - if (extended) + if (console_type_needed & CONS_EXTENDED) register_console(&netconsole_ext); - register_console(&netconsole); + if (console_type_needed & CONS_BASIC) + register_console(&netconsole); pr_info("network logging started\n"); return err; @@ -1761,7 +1809,8 @@ static void __exit cleanup_netconsole(void) if (console_is_registered(&netconsole_ext)) unregister_console(&netconsole_ext); - unregister_console(&netconsole); + if (console_is_registered(&netconsole)) + unregister_console(&netconsole); dynamic_netconsole_exit(); unregister_netdevice_notifier(&netconsole_netdev_notifier); |