mkfs.ext4 takes long time to complete with "kernel: blk: request botched"

Issue

• If a logical volume was created on devices with thin provisioning enabled, the mkfs.ext4 command took a long time to complete, and the following message was recorded in the system log:

kernel: blk: request botched

• When an LV is created on thin provisioning enabled devices, mkfs.ext4 takes a long time to complete. This is seen on hosts with Emulex LPe12002 HBAs when LV has 15 or more underlying mpath devices. When this issue is hit, we see the following messages (in thousands) in syslog:

    kernel: blk: request botched
    kernel: blk: request botched