liblp: Handle invalid alignment offsets correctly.
When stacking devices with dm-linear, it is possible to get a -1
alignment offset. In this case we should set alignment_offset to 0
rather than fail later trying to divide -1 by the sector size.
Bug: 134536978
Test: manual test
Change-Id: I3862fdda69531a3b230b7316707469a49ba871d6
diff --git a/fs_mgr/liblp/partition_opener.cpp b/fs_mgr/liblp/partition_opener.cpp
index 3b12213..cc4a882 100644
--- a/fs_mgr/liblp/partition_opener.cpp
+++ b/fs_mgr/liblp/partition_opener.cpp
@@ -64,6 +64,12 @@
PERROR << __PRETTY_FUNCTION__ << "BLKALIGNOFF failed on " << block_device;
return false;
}
+ // The kernel can return -1 here when misaligned devices are stacked (i.e.
+ // device-mapper).
+ if (alignment_offset == -1) {
+ alignment_offset = 0;
+ }
+
int logical_block_size;
if (ioctl(fd, BLKSSZGET, &logical_block_size) < 0) {
PERROR << __PRETTY_FUNCTION__ << "BLKSSZGET failed on " << block_device;