[PATCH 3.16.y-ckt 079/180] dm snapshot: fix hung bios when copy error occurs

3.16.7-ckt24 -stable review patch. If anyone has any objections, please let me know. ---8< From: Mikulas Patocka commit 385277bfb57faac44e92497104ba542cdd82d5fe upstream. When there is an error copying a chunk dm-snapshot can

[PATCH 3.16.y-ckt 079/180] dm snapshot: fix hung bios when copy error occurs

3.16.7-ckt24 -stable review patch. If anyone has any objections, please let me know. ---8< From: Mikulas Patocka commit 385277bfb57faac44e92497104ba542cdd82d5fe upstream. When there is an error copying a chunk