[PATCH 6.18 559/752] dm-integrity: fix recalculation in bitmap mode

Sasha Levin
2026-02-28T17:56:10Z

From: Mikulas Patocka <mpatocka@redhat.com>

[ Upstream commit 118ba36e446c01e3cd34b3eedabf1d9436525e1d ]

There's a logic quirk in the handling of suspend in the bitmap mode:

This is the sequence of calls if we are reloading a dm-integrity table:
* dm_integrity_ctr reads a superblock with the flag SB_FLAG_DIRTY_BITMAP
set.
* dm_integrity_postsuspend initializes a journal and clears the flag
SB_FLAG_DIRTY_BITMAP.
* dm_integrity_resume sees the superblock with SB_FLAG_DIRTY_BITMAP set -
thus it interprets the journal as if it were a bitmap.

This quirk causes recalculation problem if the user increases the size of
the device in the bitmap mode.

Fix this by reading a fresh copy on the superblock in
dm_integrity_resume. This commit also fixes another logic quirk - the
branch that sets bitmap bits if the device was extended should only be
executed if the flag SB_FLAG_DIRTY_BITMAP is set.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Tested-by: Ondrej Kozina <okozina@redhat.com>
Fixes: 468dfca38b1a ("dm integrity: add a bitmap mode")
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/md/dm-integrity.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index 79d60495454a5..ba52631052503 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -3788,14 +3788,27 @@ static void dm_integrity_resume(struct dm_target *ti)
struct dm_integrity_c *ic = ti->private;
__u64 old_provided_data_sectors = le64_to_cpu(ic->sb->provided_data_sectors);
int r;
+ __le32 flags;

DEBUG_print("resume\n");

ic->wrote_to_journal = false;

+ flags = ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING);
+ r = sync_rw_sb(ic, REQ_OP_READ);
+ if (r)
+ dm_integrity_io_error(ic, "reading superblock", r);
+ if ((ic->sb->flags & flags) != flags) {
+ ic->sb->flags |= flags;
+ r = sync_rw_sb(ic, REQ_OP_WRITE | REQ_FUA);
+ if (unlikely(r))
+ dm_integrity_io_error(ic, "writing superblock", r);
+ }
+
if (ic->provided_data_sectors != old_provided_data_sectors) {
if (ic->provided_data_sectors > old_provided_data_sectors &&
ic->mode == 'B' &&
+ ic->sb->flags & cpu_to_le32(SB_FLAG_DIRTY_BITMAP) &&
ic->sb->log2_blocks_per_bitmap_bit == ic->log2_blocks_per_bitmap_bit) {
rw_journal_sectors(ic, REQ_OP_READ, 0,
ic->n_bitmap_blocks * (BITMAP_BLOCK_SIZE >> SECTOR_SHIFT), NULL);
--
2.51.0