dm log: ensure log bitmap fits on log device

Check that the log bitmap will fit within the log device.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 40ed70df6736..737961f275c1 100644
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -457,6 +457,14 @@ static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
                  */
                 buf_size = dm_round_up((LOG_OFFSET << SECTOR_SHIFT) +
                                        bitset_size, ti->limits.hardsect_size);
+
+                if (buf_size > dev->bdev->bd_inode->i_size) {
+                        DMWARN("log device %s too small: need %llu bytes",
+                                dev->name, (unsigned long long)buf_size);
+                        kfree(lc);
+                        return -EINVAL;
+                }
+
                 lc->header_location.count = buf_size >> SECTOR_SHIFT;
 
                 lc->io_req.mem.type = DM_IO_VMA;