[PATCH 059/139] umount oops when remove blocklayoutdriver first

3.5.7.7 -stable review patch. If anyone has any objections, please let me know. -- From: fanchaoting commit 5a12cca697aca5dfba42a7d4c3356acc0445a2b0 upstream. now pnfs client uses block layout, maybe we can remove blocklayoutdriver first. if we umount later, it can cause oops

[PATCH 059/139] umount oops when remove blocklayoutdriver first

3.5.7.7 -stable review patch. If anyone has any objections, please let me know. -- From: fanchaoting fanchaot...@cn.fujitsu.com commit 5a12cca697aca5dfba42a7d4c3356acc0445a2b0 upstream. now pnfs client uses block layout, maybe we can remove blocklayoutdriver first. if we