pstore: Avoid recursive spinlocks in the oops_in_progress case

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>

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 6c23eab..a40da07 100644 (file)
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -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);