Illumos #3006

[zfs.git] / module / zfs / zfs_debug.c

diff --git a/module/zfs/zfs_debug.c b/module/zfs/zfs_debug.c
index d0f411a..ad611ac 100644 (file)
--- a/module/zfs/zfs_debug.c
+++ b/module/zfs/zfs_debug.c
@@ -20,76 +20,65 @@
  */
 /*
  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012 by Delphix. All rights reserved.
  */
 
 #include <sys/zfs_context.h>
 
-list_t zfs_dbgmsgs;
-int zfs_dbgmsg_size;
-kmutex_t zfs_dbgmsgs_lock;
-int zfs_dbgmsg_maxsize = 1<<20; /* 1MB */
+/*
+ * Enable various debugging features.
+ */
+int zfs_flags = 0;
+
+/*
+ * zfs_recover can be set to nonzero to attempt to recover from
+ * otherwise-fatal errors, typically caused by on-disk corruption.  When
+ * set, calls to zfs_panic_recover() will turn into warning messages.
+ */
+int zfs_recover = 0;
 
-void
-zfs_dbgmsg_init(void)
-{
-       list_create(&zfs_dbgmsgs, sizeof (zfs_dbgmsg_t),
-           offsetof(zfs_dbgmsg_t, zdm_node));
-       mutex_init(&zfs_dbgmsgs_lock, NULL, MUTEX_DEFAULT, NULL);
-}
 
 void
-zfs_dbgmsg_fini(void)
+zfs_panic_recover(const char *fmt, ...)
 {
-       zfs_dbgmsg_t *zdm;
+       va_list adx;
 
-       while ((zdm = list_remove_head(&zfs_dbgmsgs)) != NULL) {
-               int size = sizeof (zfs_dbgmsg_t) + strlen(zdm->zdm_msg);
-               kmem_free(zdm, size);
-               zfs_dbgmsg_size -= size;
-       }
-       mutex_destroy(&zfs_dbgmsgs_lock);
-       ASSERT3U(zfs_dbgmsg_size, ==, 0);
+       va_start(adx, fmt);
+       vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx);
+       va_end(adx);
 }
 
 /*
- * Print these messages by running:
- *     echo ::zfs_dbgmsg | mdb -k
- *
- * Monitor these messages by running:
- *     dtrace -q -n 'zfs-dbgmsg{printf("%s\n", stringof(arg0))}'
+ * Debug logging is enabled by default for production kernel builds.
+ * The overhead for this is negligible and the logs can be valuable when
+ * debugging.  For non-production user space builds all debugging except
+ * logging is enabled since performance is no longer a concern.
  */
 void
-zfs_dbgmsg(const char *fmt, ...)
+zfs_dbgmsg_init(void)
 {
-       int size;
-       va_list adx;
-       zfs_dbgmsg_t *zdm;
-
-       va_start(adx, fmt);
-       size = vsnprintf(NULL, 0, fmt, adx);
-       va_end(adx);
+       if (zfs_flags == 0) {
+#if defined(_KERNEL)
+               zfs_flags = ZFS_DEBUG_DPRINTF;
+               spl_debug_set_mask(spl_debug_get_mask() | SD_DPRINTF);
+               spl_debug_set_subsys(spl_debug_get_subsys() | SS_USER1);
+#else
+               zfs_flags = ~ZFS_DEBUG_DPRINTF;
+#endif /* _KERNEL */
+       }
+}
 
-       /*
-        * There is one byte of string in sizeof (zfs_dbgmsg_t), used
-        * for the terminating null.
-        */
-       zdm = kmem_alloc(sizeof (zfs_dbgmsg_t) + size, KM_SLEEP);
-       zdm->zdm_timestamp = gethrestime_sec();
+void
+zfs_dbgmsg_fini(void)
+{
+       return;
+}
 
-       va_start(adx, fmt);
-       (void) vsnprintf(zdm->zdm_msg, size + 1, fmt, adx);
-       va_end(adx);
 
-       DTRACE_PROBE1(zfs__dbgmsg, char *, zdm->zdm_msg);
+#if defined(_KERNEL)
+module_param(zfs_flags, int, 0644);
+MODULE_PARM_DESC(zfs_flags, "Set additional debugging flags");
 
-       mutex_enter(&zfs_dbgmsgs_lock);
-       list_insert_tail(&zfs_dbgmsgs, zdm);
-       zfs_dbgmsg_size += sizeof (zfs_dbgmsg_t) + size;
-       while (zfs_dbgmsg_size > zfs_dbgmsg_maxsize) {
-               zdm = list_remove_head(&zfs_dbgmsgs);
-               size = sizeof (zfs_dbgmsg_t) + strlen(zdm->zdm_msg);
-               kmem_free(zdm, size);
-               zfs_dbgmsg_size -= size;
-       }
-       mutex_exit(&zfs_dbgmsgs_lock);
-}
+module_param(zfs_recover, int, 0644);
+MODULE_PARM_DESC(zfs_recover, "Set to attempt to recover from fatal errors");
+#endif /* _KERNEL */