MFC r327996: geom_disk / scsi_da: deny opening write-protected disks for writing

Ths change consists of two parts.

geom_disk: deny opening a disk for writing if it's marked as
write-protected. A new disk(9) flag is added to mark write protected
disks. A possible alternative could be to add another parameter to d_open,
so that the open mode could be passed to it and the disk drivers could
make the decision internally, but the flag required less churn.

scsi_da: add a new phase of disk probing to query the all pages mode
sense page. We can determine if the disk is write protected using bit 7
of the device specific field in the mode parameter header returned by
MODE SENSE.

PR: 224037

MFC r311971: Report random flash storage as non-rotating to GEOM_DISK.

While doing it, introduce respective constants in geom_disk.h.

MFC r256956:
Improve ZFS N-way mirror read performance by using load and locality
information.

MFC r260713:
Fix ZFS mirror code for handling multiple DVA's

Also make the addition of the d_rotation_rate binary compatible. This allows
storage drivers compiled for 10.0 to work by preserving the ABI for disks.

Approved by: re (gjb)
Sponsored by: Multiplay

MFC Alexander Motin's GEOM direct dispatch work:

r256603:
Introduce new function devstat_end_transaction_bio_bt(), adding new argument
to specify present time. Use this function to move binuptime() out of lock,
substantially reducing lock congestion when slow timecounter is used.

r256606:
Move g_io_deliver() out of the lock, as required for direct dispatch.
Move g_destroy_bio() out too to reduce lock scope even more.

r256607:
Fix passing uninitialized bio_resid argument to g_trace().

r256610:
Add unmapped I/O support to GEOM RAID.

r256830:
Restore BIO_UNMAPPED and BIO_TRANSIENT_MAPPING in biodonne() when unmapping
temporary mapped buffer. That fixes double unmap if biodone() called twice
for the same BIO (but with different done methods).

r256880:
Merge GEOM direct dispatch changes from the projects/camlock branch.

When safety requirements are met, it allows to avoid passing I/O requests
to GEOM g_up/g_down thread, executing them directly in the caller context.
That allows to avoid CPU bottlenecks in g_up/g_down threads, plus avoid
several context switches per I/O.

r259247:
Fix bug introduced at r256607. We have to recalculate bp_resid here since
sizes of original and completed requests may differ due to end of media.

Testing of the stable/10 merge was done by Netflix, but all of the credit
goes to Alexander and iX Systems.

Submitted by: mav
Sponsored by: iX Systems

MFC r256956:
Improve ZFS N-way mirror read performance by using load and locality
information.

MFC r260713:
Fix ZFS mirror code for handling multiple DVA's

Also make the addition of the d_rotation_rate binary compatible. This allows
storage drivers compiled for 10.0 to work by preserving the ABI for disks.

Approved by: re (gjb)
Sponsored by: Multiplay

MFC Alexander Motin's GEOM direct dispatch work:

r256603:
Introduce new function devstat_end_transaction_bio_bt(), adding new argument
to specify present time. Use this function to move binuptime() out of lock,
substantially reducing lock congestion when slow timecounter is used.

r256606:
Move g_io_deliver() out of the lock, as required for direct dispatch.
Move g_destroy_bio() out too to reduce lock scope even more.

r256607:
Fix passing uninitialized bio_resid argument to g_trace().

r256610:
Add unmapped I/O support to GEOM RAID.

r256830:
Restore BIO_UNMAPPED and BIO_TRANSIENT_MAPPING in biodonne() when unmapping
temporary mapped buffer. That fixes double unmap if biodone() called twice
for the same BIO (but with different done methods).

r256880:
Merge GEOM direct dispatch changes from the projects/camlock branch.

When safety requirements are met, it allows to avoid passing I/O requests
to GEOM g_up/g_down thread, executing them directly in the caller context.
That allows to avoid CPU bottlenecks in g_up/g_down threads, plus avoid
several context switches per I/O.

r259247:
Fix bug introduced at r256607. We have to recalculate bp_resid here since
sizes of original and completed requests may differ due to end of media.

Testing of the stable/10 merge was done by Netflix, but all of the credit
goes to Alexander and iX Systems.

Submitted by: mav
Sponsored by: iX Systems