locking support for CAM
r256826:
Fix several target mode SIMs to not blindly clear ccb_h.flags field of
ATIO CCBs. Not all CCB flags there belong to them.
r256836:
Remove hard limit on number of BIOs handled with one ATA TRIM request.
r256843:
Merge CAM locking changes from the projects/camlock branch to radically
reduce lock congestion and improve SMP scalability of the SCSI/ATA stack,
preparing the ground for the coming next GEOM direct dispatch support.
r256888:
Unconditionally acquire periph reference on CCB allocation failure.
r256895:
Fix memory and references leak due to unfreed path.
r256960:
Move CAM_UNQUEUED_INDEX setting to the last moment and under the periph lock.
This fixes race condition with cam_periph_ccbwait(), causing use-after-free.
r256975:
Minor (mostly cosmetical) addition to r256960.
r257054:
Some microoptimizations for da and ada drivers:
- Replace ordered_tag_count counter with single flag;
- From da remove outstanding_cmds counter, duplicating pending_ccbs list;
- From da_softc remove unused links field.
r257482:
Fix lock recursion, triggered by `smartctl -a /dev/adaX`.
r257501:
Make getenv_*() functions and respectively TUNABLE_*_FETCH() macros not
allocate memory and so not require sleepable environment. getenv() has
already used on-stack temporary storage, so just use it more rationally.
getenv_string() receives buffer as argument, so don't need another one.
r257914:
Some CAM locks polishing:
- Fix LOR and possible lock recursion when handling high-power commands.
Introduce new lock to protect left power quota and list of frozen devices.
- Correct locking around xpt periph creation.
- Remove seems never used XPT_FLAG_OPEN xpt periph flag.
Again, Netflix assisted with testing the merge, but all of the credit goes
to Alexander and iX Systems.
Submitted by: mav
Sponsored by: iX Systems