From a50527b19c62c808a7fca022816fff88a50b948d Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 2 Dec 2011 09:17:02 +0800 Subject: fs: Make write(2) interruptible by a fatal signal Currently write(2) to a file is not interruptible by any signal. Sometimes this is desirable, e.g. when you want to quickly kill a process hogging your disk. Also, with commit 499d05ecf990 ("mm: Make task in balance_dirty_pages() killable"), it's necessary to abort the current write accordingly to avoid it quickly dirtying lots more pages at unthrottled rate. This patch makes write interruptible by SIGKILL. We do not allow write to be interruptible by any other signal because that has larger potential of screwing some badly written applications. Reported-by: Kazuya Mio Tested-by: Kazuya Mio Acked-by: Matthew Wilcox Signed-off-by: Jan Kara Signed-off-by: Wu Fengguang --- mm/filemap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/filemap.c b/mm/filemap.c index c0018f2d50e0..c106d3b3cc64 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2407,7 +2407,6 @@ static ssize_t generic_perform_write(struct file *file, iov_iter_count(i)); again: - /* * Bring in the user page that we will copy from _first_. * Otherwise there's a nasty deadlock on copying from the @@ -2463,7 +2462,10 @@ again: written += copied; balance_dirty_pages_ratelimited(mapping); - + if (fatal_signal_pending(current)) { + status = -EINTR; + break; + } } while (iov_iter_count(i)); return written ? written : status; -- cgit v1.2.1