pstore: Avoid recursive spinlocks in the oops_in_progress case
authorChuansheng Liu <chuansheng.liu@intel.com>
Mon, 17 Sep 2012 17:43:44 +0000 (01:43 +0800)
committerAnton Vorontsov <anton.vorontsov@linaro.org>
Fri, 21 Sep 2012 00:04:50 +0000 (17:04 -0700)
Like 8250 driver, when pstore is registered as a console,
to avoid recursive spinlocks when panic happening, change the
spin_lock_irqsave to spin_trylock_irqsave when oops_in_progress
is true.

Signed-off-by: liu chuansheng <chuansheng.liu@intel.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
fs/pstore/platform.c

index 6c23eab..a40da07 100644 (file)
@@ -164,7 +164,13 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c)
 
                if (c > psinfo->bufsize)
                        c = psinfo->bufsize;
 
                if (c > psinfo->bufsize)
                        c = psinfo->bufsize;
-               spin_lock_irqsave(&psinfo->buf_lock, flags);
+
+               if (oops_in_progress) {
+                       if (!spin_trylock_irqsave(&psinfo->buf_lock, flags))
+                               break;
+               } else {
+                       spin_lock_irqsave(&psinfo->buf_lock, flags);
+               }
                memcpy(psinfo->buf, s, c);
                psinfo->write(PSTORE_TYPE_CONSOLE, 0, NULL, 0, c, psinfo);
                spin_unlock_irqrestore(&psinfo->buf_lock, flags);
                memcpy(psinfo->buf, s, c);
                psinfo->write(PSTORE_TYPE_CONSOLE, 0, NULL, 0, c, psinfo);
                spin_unlock_irqrestore(&psinfo->buf_lock, flags);