From 76c31f239ea221a6c84bd26141262a43bfe8b7f4 Mon Sep 17 00:00:00 2001 From: Vitaly Mayatskikh Date: Sun, 28 Sep 2008 23:24:33 +0000 Subject: [PATCH] powerpc: Honor O_NONBLOCK flag when reading RTAS log rtas_log_read() doesn't check file flags for O_NONBLOCK and blocks non-blocking readers of /proc/ppc64/rtas/error_log when there is no data available. This fixes it. Also rtas_log_read() returns now with ENODATA to prevent suspending of process in wait_event_interruptible() when logging facility was switched off and log is already empty. Signed-off-by: Vitaly Mayatskikh Acked-by: David Howells Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/platforms/pseries/rtasd.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/platforms/pseries/rtasd.c b/arch/powerpc/platforms/pseries/rtasd.c index c9ffd8c225f..f4e55be2eea 100644 --- a/arch/powerpc/platforms/pseries/rtasd.c +++ b/arch/powerpc/platforms/pseries/rtasd.c @@ -295,19 +295,29 @@ static ssize_t rtas_log_read(struct file * file, char __user * buf, if (!tmp) return -ENOMEM; - spin_lock_irqsave(&rtasd_log_lock, s); /* if it's 0, then we know we got the last one (the one in NVRAM) */ - if (rtas_log_size == 0 && logging_enabled) - nvram_clear_error_log(); - spin_unlock_irqrestore(&rtasd_log_lock, s); + while (rtas_log_size == 0) { + if (file->f_flags & O_NONBLOCK) { + spin_unlock_irqrestore(&rtasd_log_lock, s); + error = -EAGAIN; + goto out; + } + if (!logging_enabled) { + spin_unlock_irqrestore(&rtasd_log_lock, s); + error = -ENODATA; + goto out; + } + nvram_clear_error_log(); - error = wait_event_interruptible(rtas_log_wait, rtas_log_size); - if (error) - goto out; + spin_unlock_irqrestore(&rtasd_log_lock, s); + error = wait_event_interruptible(rtas_log_wait, rtas_log_size); + if (error) + goto out; + spin_lock_irqsave(&rtasd_log_lock, s); + } - spin_lock_irqsave(&rtasd_log_lock, s); offset = rtas_error_log_buffer_max * (rtas_log_start & LOG_NUMBER_MASK); memcpy(tmp, &rtas_log_buf[offset], count); -- 2.20.1