From 0e79e3736d54bb8efbc9fb29cc3b54a132783565 Mon Sep 17 00:00:00 2001 From: Shiyang Ruan Date: Thu, 1 Dec 2022 15:31:41 +0000 Subject: 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: Shiyang Ruan Reviewed-by: Darrick J. Wong Cc: Alistair Popple Cc: Dan Williams Cc: Dave Chinner Cc: Jason Gunthorpe Cc: John Hubbard Signed-off-by: Andrew Morton --- fs/dax.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'fs') diff --git a/fs/dax.c b/fs/dax.c index fa547ce41add..8fb928cd9dce 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -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; } -- cgit