diff mbox series

[5.11,23/44] dm bufio: subtract the number of initial sectors in dm_bufio_get_device_size

Message ID 20210308122719.718755688@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg Kroah-Hartman March 8, 2021, 12:35 p.m. UTC 
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

From: Mikulas Patocka <mpatocka@redhat.com>

commit a14e5ec66a7a66e57b24e2469f9212a78460207e upstream.

dm_bufio_get_device_size returns the device size in blocks. Before
returning the value, we must subtract the nubmer of starting
sectors. The number of starting sectors 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 change has no effect.
However, an upcoming dm-verity-fec fix needs this change.

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

Patch

--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1526,6 +1526,10 @@  EXPORT_SYMBOL_GPL(dm_bufio_get_block_siz
 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