Commit 2b838687 authored Jun 09, 2009 by Linus Torvalds

Make /dev/zero reads interruptible by signals

This helps with bad latencies for large reads from /dev/zero, but might
conceivably break some application that "knows" that a read of /dev/zero
cannot return early. So do this early in the merge window to give us
maximal test coverage, even if the patch is totally trivial.

Obviously, no well-behaved application should ever depend on the read
being uninterruptible, but hey, bugs happen.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 07a2039b

drivers/char/mem.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -694,9 +694,8 @@ static ssize_t read_zero(struct file * file, char __user * buf,
		written += chunk - unwritten;
		if (unwritten)
		break;
		/* Consider changing this to just 'signal_pending()' with lots of testing */
		if (fatal_signal_pending(current))
		return written ? written : -EINTR;
		if (signal_pending(current))
		return written ? written : -ERESTARTSYS;
		buf += chunk;
		count -= chunk;
		cond_resched();

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