Commit 0e79e373 authored by Shiyang Ruan's avatar Shiyang Ruan Committed by Andrew Morton
Browse files

fsdax: dedupe: iter two files at the same time 

The iomap_iter() on a range of one file may loop more than once.  In this
case, the inner dst_iter can update its iomap but the outer src_iter
can't.  This may cause the wrong remapping in filesystem.  Let them called
at the same time.

Link: https://lkml.kernel.org/r/1669908701-93-1-git-send-email-ruansy.fnst@fujitsu.com


Signed-off-by: default avatarShiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent c6f0b395

fs/dax.c

+8 −8
Original line number Diff line number Diff line
@@ -1965,15 +1965,15 @@ int dax_dedupe_file_range_compare(struct inode *src, loff_t srcoff, 
		.len		= len,

		.flags		= IOMAP_DAX,

	};

	int ret;

	int ret, compared = 0;



	while ((ret = iomap_iter(&src_iter, ops)) > 0) {

		while ((ret = iomap_iter(&dst_iter, ops)) > 0) {

			dst_iter.processed = dax_range_compare_iter(&src_iter,

						&dst_iter, len, same);

		}

		if (ret <= 0)

			src_iter.processed = ret;

	while ((ret = iomap_iter(&src_iter, ops)) > 0 &&

	       (ret = iomap_iter(&dst_iter, ops)) > 0) {

		compared = dax_range_compare_iter(&src_iter, &dst_iter, len,

						  same);

		if (compared < 0)

			return ret;

		src_iter.processed = dst_iter.processed = compared;

	}

	return ret;

}