[PATCH 5.4 165/232] dm clone metadata: Fix return type of dm_clone_nr_of_hydrated_regions()

From: Greg Kroah-Hartman
Date: Thu Apr 16 2020 - 11:17:07 EST


From: Nikos Tsironis <ntsironis@xxxxxxxxxxx>

commit 81d5553d1288c2ec0390f02f84d71ca0f0f9f137 upstream.

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@xxxxxxxxxxxxxxx # v5.4+
Signed-off-by: Nikos Tsironis <ntsironis@xxxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
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(-)

--- 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 d
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);
}
--- a/drivers/md/dm-clone-metadata.h
+++ b/drivers/md/dm-clone-metadata.h
@@ -154,7 +154,7 @@ bool dm_clone_is_range_hydrated(struct d
/*
* 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
--- a/drivers/md/dm-clone-target.c
+++ b/drivers/md/dm-clone-target.c
@@ -1455,7 +1455,7 @@ static void clone_status(struct dm_targe
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,