[ewg] Mellanox target workaround in SRP

[Roland Dreier]

 > I think that the patch is specific for srp initiator using Mellanox
 > FMR. It tried to avoid indirect desc with Mellanox FMR having
 > first-byte-offset != 0.  Since the low level implementation of
 > mlx4/mthca_map_phys_fmr() did not create + setup MPT for FMR with
 > first_byte_offset != 0. The corruption can happen with any target.

I don't think this could be right -- right now the workaround only
triggers if the target has a Mellanox OUI, so if what you say is true,
presumably everyone who is using the SRP initiator with mlx4 would be
seeing this problem.

Also, the SRP initiator code that uses ib_fmr_pool_map_phys does not
pass in any non-aligned addresses -- it doesn't try to use any first
byte offset, it just uses the virtual address it passes to the target to
handle the offset.

 - R.