module_param_named(update_ms, pstore_update_ms, int, 0600);
MODULE_PARM_DESC(update_ms, "milliseconds before pstore updates its content "
"(default is -1, which means runtime updates are disabled; "
- "enabling this option is not safe, it may lead to further "
+ "enabling this option may not be safe; it may lead to further "
"corruption on Oopses)");
/* Names should be in the same order as the enum pstore_type_id */
static DECLARE_WORK(pstore_work, pstore_dowork);
/*
- * pstore_lock just protects "psinfo" during
- * calls to pstore_register()
+ * psinfo_lock protects "psinfo" during calls to
+ * pstore_register(), pstore_unregister(), and
+ * the filesystem mount/unmount routines.
*/
-static DEFINE_SPINLOCK(pstore_lock);
+static DEFINE_MUTEX(psinfo_lock);
struct pstore_info *psinfo;
static char *backend;
+module_param(backend, charp, 0444);
+MODULE_PARM_DESC(backend, "specific backend to use");
+
static char *compress =
#ifdef CONFIG_PSTORE_COMPRESS_DEFAULT
CONFIG_PSTORE_COMPRESS_DEFAULT;
#else
NULL;
#endif
+module_param(compress, charp, 0444);
+MODULE_PARM_DESC(compress, "compression to use");
/* Compression parameters */
static struct crypto_comp *tfm;
}
EXPORT_SYMBOL_GPL(pstore_name_to_type);
-static const char *get_reason_str(enum kmsg_dump_reason reason)
+static void pstore_timer_kick(void)
{
- switch (reason) {
- case KMSG_DUMP_PANIC:
- return "Panic";
- case KMSG_DUMP_OOPS:
- return "Oops";
- case KMSG_DUMP_EMERG:
- return "Emergency";
- case KMSG_DUMP_RESTART:
- return "Restart";
- case KMSG_DUMP_HALT:
- return "Halt";
- case KMSG_DUMP_POWEROFF:
- return "Poweroff";
- default:
- return "Unknown";
- }
+ if (pstore_update_ms < 0)
+ return;
+
+ mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms));
}
/*
unsigned int part = 1;
int ret;
- why = get_reason_str(reason);
+ why = kmsg_dump_reason_str(reason);
if (down_trylock(&psinfo->buf_lock)) {
/* Failed to acquire lock: give up if we cannot wait. */
}
ret = psinfo->write(&record);
- if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted())
+ if (ret == 0 && reason == KMSG_DUMP_OOPS) {
pstore_new_entry = 1;
+ pstore_timer_kick();
+ }
total += record.size;
part++;
}
static struct console pstore_console = {
- .name = "pstore",
.write = pstore_console_write,
- .flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME,
.index = -1,
};
static void pstore_register_console(void)
{
+ /* Show which backend is going to get console writes. */
+ strscpy(pstore_console.name, psinfo->name,
+ sizeof(pstore_console.name));
+ /*
+ * Always initialize flags here since prior unregister_console()
+ * calls may have changed settings (specifically CON_ENABLED).
+ */
+ pstore_console.flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME;
register_console(&pstore_console);
}
*/
int pstore_register(struct pstore_info *psi)
{
- struct module *owner = psi->owner;
-
if (backend && strcmp(backend, psi->name)) {
pr_warn("ignoring unexpected backend '%s'\n", psi->name);
return -EPERM;
return -EINVAL;
}
- spin_lock(&pstore_lock);
+ mutex_lock(&psinfo_lock);
if (psinfo) {
pr_warn("backend '%s' already loaded: ignoring '%s'\n",
psinfo->name, psi->name);
- spin_unlock(&pstore_lock);
+ mutex_unlock(&psinfo_lock);
return -EBUSY;
}
psinfo = psi;
mutex_init(&psinfo->read_mutex);
sema_init(&psinfo->buf_lock, 1);
- spin_unlock(&pstore_lock);
-
- if (owner && !try_module_get(owner)) {
- psinfo = NULL;
- return -EINVAL;
- }
if (psi->flags & PSTORE_FLAGS_DMESG)
allocate_buf_for_compression();
- if (pstore_is_mounted())
- pstore_get_records(0);
+ pstore_get_records(0);
- if (psi->flags & PSTORE_FLAGS_DMESG)
+ if (psi->flags & PSTORE_FLAGS_DMESG) {
+ pstore_dumper.max_reason = psinfo->max_reason;
pstore_register_kmsg();
+ }
if (psi->flags & PSTORE_FLAGS_CONSOLE)
pstore_register_console();
if (psi->flags & PSTORE_FLAGS_FTRACE)
pstore_register_pmsg();
/* Start watching for new records, if desired. */
- if (pstore_update_ms >= 0) {
- pstore_timer.expires = jiffies +
- msecs_to_jiffies(pstore_update_ms);
- add_timer(&pstore_timer);
- }
+ pstore_timer_kick();
/*
* Update the module parameter backend, so it is visible
* through /sys/module/pstore/parameters/backend
*/
- backend = psi->name;
+ backend = kstrdup(psi->name, GFP_KERNEL);
pr_info("Registered %s as persistent store backend\n", psi->name);
- module_put(owner);
-
+ mutex_unlock(&psinfo_lock);
return 0;
}
EXPORT_SYMBOL_GPL(pstore_register);
void pstore_unregister(struct pstore_info *psi)
{
- /* Stop timer and make sure all work has finished. */
- pstore_update_ms = -1;
- del_timer_sync(&pstore_timer);
- flush_work(&pstore_work);
+ /* It's okay to unregister nothing. */
+ if (!psi)
+ return;
+
+ mutex_lock(&psinfo_lock);
+
+ /* Only one backend can be registered at a time. */
+ if (WARN_ON(psi != psinfo)) {
+ mutex_unlock(&psinfo_lock);
+ return;
+ }
+ /* Unregister all callbacks. */
if (psi->flags & PSTORE_FLAGS_PMSG)
pstore_unregister_pmsg();
if (psi->flags & PSTORE_FLAGS_FTRACE)
if (psi->flags & PSTORE_FLAGS_DMESG)
pstore_unregister_kmsg();
+ /* Stop timer and make sure all work has finished. */
+ del_timer_sync(&pstore_timer);
+ flush_work(&pstore_work);
+
+ /* Remove all backend records from filesystem tree. */
+ pstore_put_backend_records(psi);
+
free_buf_for_compression();
psinfo = NULL;
+ kfree(backend);
backend = NULL;
+ mutex_unlock(&psinfo_lock);
}
EXPORT_SYMBOL_GPL(pstore_unregister);
schedule_work(&pstore_work);
}
- if (pstore_update_ms >= 0)
- mod_timer(&pstore_timer,
- jiffies + msecs_to_jiffies(pstore_update_ms));
+ pstore_timer_kick();
}
static void __init pstore_choose_compression(void)
}
module_exit(pstore_exit)
-module_param(compress, charp, 0444);
-MODULE_PARM_DESC(compress, "Pstore compression to use");
-
-module_param(backend, charp, 0444);
-MODULE_PARM_DESC(backend, "Pstore backend to use");
-
MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>");
MODULE_LICENSE("GPL");
projects / linux-2.6-microblaze.git / blobdiff