From a9c0fda4c08292399e08db0a4b70bc161cd247b9 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 27 Apr 2021 11:57:06 -0400 Subject: [PATCH] dm integrity: don't re-write metadata if discarding same blocks If we discard already discarded blocks we do not need to write discard pattern to the metadata, because it is already there. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm-integrity.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index 6977422454a4..3b54b7f8c9b9 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -1429,8 +1429,10 @@ static int dm_integrity_rw_tag(struct dm_integrity_c *ic, unsigned char *tag, se if (op == TAG_READ) { memcpy(tag, dp, to_copy); } else if (op == TAG_WRITE) { - memcpy(dp, tag, to_copy); - dm_bufio_mark_partial_buffer_dirty(b, *metadata_offset, *metadata_offset + to_copy); + if (memcmp(dp, tag, to_copy)) { + memcpy(dp, tag, to_copy); + dm_bufio_mark_partial_buffer_dirty(b, *metadata_offset, *metadata_offset + to_copy); + } } else { /* e.g.: op == TAG_CMP */ -- GitLab