Pass flags to more DMU write/hold functions

[amotin]

Over the time many of DMU functions got flags argument to control prefetch, caching, etc. Few functions though left without it, even though closer look shown that many of them do not benefit from prefetch due to their access pattern. This patch adds the flags argument to dmu_write(), dmu_buf_hold_array() and dmu_buf_hold_array_by_bonus(), passing DMU_READ_NO_PREFETCH where applicable.

I am going to also pass DMU_UNCACHEDIO to some of them later.

How Has This Been Tested?

Build-tested on FreeBSD. I don't expect any effects visible without precise instrumentation.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Performance enhancement (non-breaking change which improves efficiency)
• Code cleanup (non-breaking change which makes code smaller or more readable)
• Quality assurance (non-breaking change which makes the code more robust against bugs)
• Breaking change (fix or feature that would cause existing functionality to change)
• Library ABI change (libzfs, libzfs_core, libnvpair, libuutil and libzfsbootenv)
• Documentation (a change to man pages or other documentation)

Checklist:

• My code follows the OpenZFS code style requirements.
• I have updated the documentation accordingly.
• I have read the contributing document.
• I have added tests to cover my changes.
• I have run the ZFS Test Suite with this change applied.
• All commit messages are properly formatted and contain Signed-off-by.

[robn]

Seems right. I didn't think very hard about the things changed to DMU_READ_NO_PREFETCH, but they all (?) seem to be not on hot data paths so I suspect fine.