MFS10 r273767 / MFC r273638:
Revert somewhat hackish geom_disk optimization, committed as part of r256880,
and the following r273143 commit, supposed to workaround introduced issue by
quite innocent-looking change.

While there is no clear understanding why, but r273143 is accused in data
corruption in some environments with high I/O load. I personally don't see
any problem in that commit, and possibly it is just a trigger to some other
bug somewhere, but better safe then sorry for now.

Requested by: scottl@
Approved by: re (kib@)

MFS10 r273272 (r273143 in head):
Remove setting BIO_DONE flag for BIOs that have done() method.

This fixes use-after-free, caused by geom_disk, completing same BIO twice
to save extra allocation, and getting BIO_DONE set after the first.

Approved by: re (hrs)

MFS10 r273767 / MFC r273638:
Revert somewhat hackish geom_disk optimization, committed as part of r256880,
and the following r273143 commit, supposed to workaround introduced issue by
quite innocent-looking change.

While there is no clear understanding why, but r273143 is accused in data
corruption in some environments with high I/O load. I personally don't see
any problem in that commit, and possibly it is just a trigger to some other
bug somewhere, but better safe then sorry for now.

Requested by: scottl@
Approved by: re (kib@)

MFS10 r273272 (r273143 in head):
Remove setting BIO_DONE flag for BIOs that have done() method.

This fixes use-after-free, caused by geom_disk, completing same BIO twice
to save extra allocation, and getting BIO_DONE set after the first.

Approved by: re (hrs)