K 10
svn:author
V 3
alc
K 8
svn:date
V 27
2005-07-20T19:06:06.000000Z
K 7
svn:log
V 631
Eliminate inconsistency in the setting of the B_DONE flag.  Specifically,
make the b_iodone callback responsible for setting it if it is needed.
Previously, it was set unconditionally by bufdone() without holding
whichever lock is shared by the b_iodone callback and the corresponding
top-half function.  Consequently, in a race, the top-half function could
conclude that operation was done before the b_iodone callback finished.
See, for example, aio_physwakeup() and aio_fphysio().

Note: I don't believe that the other, more widely-used b_iodone callbacks
are affected.

Discussed with: jeff
Reviewed by: phk
MFC after: 2 weeks

END