diff mbox series

[1/2] dm-bufio: subtract the number of initial sectors in dm_bufio_get_device_size

Message ID 20210223202121.898736-1-gmazyland@gmail.com (mailing list archive)
State Accepted, archived
Delegated to: Mike Snitzer
Headers show
Series [1/2] dm-bufio: subtract the number of initial sectors in dm_bufio_get_device_size | expand

Commit Message

Milan Broz Feb. 23, 2021, 8:21 p.m. UTC 
From: Mikulas Patocka <mpatocka@redhat.com>

dm_bufio_get_device_size returns returns the device size in blocks. Before
returning the value, we must subtract the nubmer of starting sectors. The
number of starting sectos may not be divisible by block size.

Note that currently, no target is using dm_bufio_set_sector_offset and
dm_bufio_get_device_size simultaneously, so this patch has no effect.
However, an upcoming patch that fixes dm-verity-fec needs this change.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Milan Broz <gmazyland@gmail.com>
Cc: stable@vger.kernel.org
---
 drivers/md/dm-bufio.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index fce4cbf9529d..50f3e673729c 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1526,6 +1526,10 @@  EXPORT_SYMBOL_GPL(dm_bufio_get_block_size);
 sector_t dm_bufio_get_device_size(struct dm_bufio_client *c)
 {
 	sector_t s = i_size_read(c->bdev->bd_inode) >> SECTOR_SHIFT;
+	if (s >= c->start)
+		s -= c->start;
+	else
+		s = 0;
 	if (likely(c->sectors_per_block_bits >= 0))
 		s >>= c->sectors_per_block_bits;
 	else