From: Eduard - Gabriel Munteanu This moves the pipe waiting code from tracing_read_pipe() into tracing_wait_pipe(), which is useful to implement other fops, like splice_read. Signed-off-by: Eduard - Gabriel Munteanu Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 69 +++++++++++++++++++++++++++++--------------------- 1 files changed, 40 insertions(+), 29 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 9e29fdb..11fde0a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2388,37 +2388,15 @@ tracing_poll_pipe(struct file *filp, poll_table *poll_table) } } -/* - * Consumer reader. - */ -static ssize_t -tracing_read_pipe(struct file *filp, char __user *ubuf, - size_t cnt, loff_t *ppos) +/* Must be called with trace_types_lock mutex held. */ +static int tracing_wait_pipe(struct file *filp) { struct trace_iterator *iter = filp->private_data; - ssize_t sret; - - /* return any leftover data */ - sret = trace_seq_to_user(&iter->seq, ubuf, cnt); - if (sret != -EBUSY) - return sret; - - trace_seq_reset(&iter->seq); - mutex_lock(&trace_types_lock); - if (iter->trace->read) { - sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); - if (sret) - goto out; - } - -waitagain: - sret = 0; while (trace_empty(iter)) { if ((filp->f_flags & O_NONBLOCK)) { - sret = -EAGAIN; - goto out; + return -EAGAIN; } /* @@ -2443,12 +2421,11 @@ waitagain: iter->tr->waiter = NULL; if (signal_pending(current)) { - sret = -EINTR; - goto out; + return -EINTR; } if (iter->trace != current_trace) - goto out; + return 0; /* * We block until we read something and tracing is disabled. @@ -2465,9 +2442,43 @@ waitagain: continue; } + return 1; +} + +/* + * Consumer reader. + */ +static ssize_t +tracing_read_pipe(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + struct trace_iterator *iter = filp->private_data; + ssize_t sret; + + /* return any leftover data */ + sret = trace_seq_to_user(&iter->seq, ubuf, cnt); + if (sret != -EBUSY) + return sret; + + trace_seq_reset(&iter->seq); + + mutex_lock(&trace_types_lock); + if (iter->trace->read) { + sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); + if (sret) + goto out; + } + +waitagain: + sret = tracing_wait_pipe(filp); + if (sret <= 0) + goto out; + /* stop when tracing is finished */ - if (trace_empty(iter)) + if (trace_empty(iter)) { + sret = 0; goto out; + } if (cnt >= PAGE_SIZE) cnt = PAGE_SIZE - 1; -- 1.5.6.5 -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/