fs: make cont_expand_zero interruptible
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 <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/buffer.c b/fs/buffer.c
index 3588a80..c8a1c01 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2318,6 +2318,11 @@
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 */