Re: [PATCH 2/2] dax: assert that i_rwsem is held exclusive for writes
From: Jan Kara <jack@suse.cz>
Date: 2017-01-11 09:02:58
Also in:
linux-fsdevel, nvdimm
On Tue 10-01-17 16:48:08, Christoph Hellwig wrote:
Make sure all callers follow the same locking protocol, given that DAX transparantly replaced the normal buffered I/O path. Signed-off-by: Christoph Hellwig <hch@lst.de>
Looks good. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Probably also for Ted since it depends on the ext4 fix... Honza
quoted hunk ↗ jump to hunk
--- fs/dax.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)diff --git a/fs/dax.c b/fs/dax.c index 5c74f60..04734da 100644 --- a/fs/dax.c +++ b/fs/dax.c@@ -1061,8 +1061,12 @@ dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, loff_t pos = iocb->ki_pos, ret = 0, done = 0; unsigned flags = 0; - if (iov_iter_rw(iter) == WRITE) + if (iov_iter_rw(iter) == WRITE) { + lockdep_assert_held_exclusive(&inode->i_rwsem); flags |= IOMAP_WRITE; + } else { + lockdep_assert_held(&inode->i_rwsem); + } while (iov_iter_count(iter)) { ret = iomap_apply(inode, pos, iov_iter_count(iter), flags, ops,-- 2.1.4
-- Jan Kara [off-list ref] SUSE Labs, CR