[GIT PULL] Discard regression fix for 4.3

Hi Linus, This is a fix for a discard performance issues on a particular NVMe device. I originally thought this regression was introduced prior to this merge window and wanted to just make it part of the 4.4 merge window patches and mark it stable, but it has in fact been introduced in this

[GIT PULL] Discard regression fix for 4.3

Hi Linus, This is a fix for a discard performance issues on a particular NVMe device. I originally thought this regression was introduced prior to this merge window and wanted to just make it part of the 4.4 merge window patches and mark it stable, but it has in fact been introduced in this