[ Upstream commit 9b46418c40fe910e6537618f9932a8be78a3dd6c ]
After the copy operation completes the cache is not up-to-date. Truncate
all pages in the interval that has successfully been copied.
Truncating completely copied dirty pages is okay, since the data has been
overwritten anyway. Truncating partially copied dirty pages is not okay;
add a comment for now.
Fixes: 88bc7d5097a1 ("fuse: add support for copy_file_range()")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2c4656dfd994538176db30ce09c02cc0dfc361ae ]
a) Dirty cache needs to be written back not just in the writeback_cache
case, since the dirty pages may come from memory maps.
b) The fuse_writeback_range() helper takes an inclusive interval, so the
end position needs to be pos+len-1 instead of pos+len.
Fixes: 88bc7d5097a1 ("fuse: add support for copy_file_range()")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bb737bbe48bea9854455cb61ea1dc06e92ce586c ]
In virtiofs (unlike in regular fuse) processing of async replies is
serialized. This can result in a deadlock in rare corner cases when
there's a circular dependency between the completion of two or more async
replies.
Such a deadlock can be reproduced with xfstests:generic/503 if TEST_DIR ==
SCRATCH_MNT (which is a misconfiguration):
- Process A is waiting for page lock in worker thread context and blocked
(virtio_fs_requests_done_work()).
- Process B is holding page lock and waiting for pending writes to
finish (fuse_wait_on_page_writeback()).
- Write requests are waiting in virtqueue and can't complete because
worker thread is blocked on page lock (process A).
Fix this by creating a unique work_struct for each async reply that can
block (O_DIRECT read).
Fixes: a62a8ef9d97d ("virtio-fs: add virtiofs filesystem")
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Miklos Szeredi