[dm-devel] [PATCH 4/4] dm clone metadata: Fix return type of dm_clone_nr_of_hydrated_regions()

Nikos Tsironis ntsironis at arrikto.com
Fri Mar 27 14:01:11 UTC 2020


dm_clone_nr_of_hydrated_regions() returns the number of regions that
have been hydrated so far. In order to do so it employs bitmap_weight().

Until now, the return type of dm_clone_nr_of_hydrated_regions() was
unsigned long.

Because bitmap_weight() returns an int, in case BITS_PER_LONG == 64 and
the return value of bitmap_weight() is 2^31 (the maximum allowed number
of regions for a device), the result is sign extended from 32 bits to 64
bits and an incorrect value is displayed, in the status output of
dm-clone, as the number of hydrated regions.

Fix this by having dm_clone_nr_of_hydrated_regions() return an unsigned
int.

Fixes: 7431b7835f55 ("dm: add clone target")
Cc: stable at vger.kernel.org # v5.4+
Signed-off-by: Nikos Tsironis <ntsironis at arrikto.com>
---
 drivers/md/dm-clone-metadata.c | 2 +-
 drivers/md/dm-clone-metadata.h | 2 +-
 drivers/md/dm-clone-target.c   | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/md/dm-clone-metadata.c b/drivers/md/dm-clone-metadata.c
index 199e7af00858..17712456fa63 100644
--- a/drivers/md/dm-clone-metadata.c
+++ b/drivers/md/dm-clone-metadata.c
@@ -656,7 +656,7 @@ bool dm_clone_is_range_hydrated(struct dm_clone_metadata *cmd,
 	return (bit >= (start + nr_regions));
 }
 
-unsigned long dm_clone_nr_of_hydrated_regions(struct dm_clone_metadata *cmd)
+unsigned int dm_clone_nr_of_hydrated_regions(struct dm_clone_metadata *cmd)
 {
 	return bitmap_weight(cmd->region_map, cmd->nr_regions);
 }
diff --git a/drivers/md/dm-clone-metadata.h b/drivers/md/dm-clone-metadata.h
index 14af1ebd853f..d848b8799c07 100644
--- a/drivers/md/dm-clone-metadata.h
+++ b/drivers/md/dm-clone-metadata.h
@@ -156,7 +156,7 @@ bool dm_clone_is_range_hydrated(struct dm_clone_metadata *cmd,
 /*
  * Returns the number of hydrated regions.
  */
-unsigned long dm_clone_nr_of_hydrated_regions(struct dm_clone_metadata *cmd);
+unsigned int dm_clone_nr_of_hydrated_regions(struct dm_clone_metadata *cmd);
 
 /*
  * Returns the first unhydrated region with region_nr >= @start
diff --git a/drivers/md/dm-clone-target.c b/drivers/md/dm-clone-target.c
index ca5020c58f7c..5ce96ddf1ce1 100644
--- a/drivers/md/dm-clone-target.c
+++ b/drivers/md/dm-clone-target.c
@@ -1473,7 +1473,7 @@ static void clone_status(struct dm_target *ti, status_type_t type,
 			goto error;
 		}
 
-		DMEMIT("%u %llu/%llu %llu %lu/%lu %u ",
+		DMEMIT("%u %llu/%llu %llu %u/%lu %u ",
 		       DM_CLONE_METADATA_BLOCK_SIZE,
 		       (unsigned long long)(nr_metadata_blocks - nr_free_metadata_blocks),
 		       (unsigned long long)nr_metadata_blocks,
-- 
2.11.0





More information about the dm-devel mailing list