From: Mikulas Patocka Date: Sun, 27 Jul 2014 17:00:41 +0000 (-0400) Subject: fs: make cont_expand_zero interruptible X-Git-Tag: submit/tizen/20160422.055611~1^2~99^2~11^2~304 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9c5f9dcad8be822dd4ebe7f9640b0c8af2c57122;p=sdk%2Femulator%2Femulator-kernel.git fs: make cont_expand_zero interruptible commit c2ca0fcd202863b14bd041a7fece2e789926c225 upstream. This patch makes it possible to kill a process looping in cont_expand_zero. A process may spend a lot of time in this function, so it is desirable to be able to kill it. It happened to me that I wanted to copy a piece data from the disk to a file. By mistake, I used the "seek" parameter to dd instead of "skip". Due to the "seek" parameter, dd attempted to extend the file and became stuck doing so - the only possibility was to reset the machine or wait many hours until the filesystem runs out of space and cont_expand_zero fails. We need this patch to be able to terminate the process. Signed-off-by: Mikulas Patocka Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/buffer.c b/fs/buffer.c index 71e2d0ed8530..2e0a9e12089b 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2313,6 +2313,11 @@ static int cont_expand_zero(struct file *file, struct address_space *mapping, err = 0; balance_dirty_pages_ratelimited(mapping); + + if (unlikely(fatal_signal_pending(current))) { + err = -EINTR; + goto out; + } } /* page covers the boundary, find the boundary offset */