| From | Luis Henriques <> | Subject | [PATCH 3.16.y-ckt 084/254] fs: make cont_expand_zero interruptible | Date | Tue, 25 Nov 2014 10:37:14 +0000 |
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3.16.7-ckt2 -stable review patch. If anyone has any objections, please let me know.
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From: Mikulas Patocka <mpatocka@redhat.com>
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 <mpatocka@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- fs/buffer.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/fs/buffer.c b/fs/buffer.c index 19a78d074e0d..4752094053f9 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2328,6 +2328,11 @@ 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 */ -- 2.1.0
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