MFC r248562:
Move the vn_start_write() call in the dounmount() before setting the
MNTK_UNMOUNT flag.
MFC r248563:
Increment the write ref counter for the buffer object before calling
bundirty().
MFC r248968:
Record the correct error in the trace.
MFC r248967:
Strip the unnneeded spaces, mostly at the end of lines.
MFC r248567:
Do not call vnode_pager_setsize() while a NFS node mutex is
locked. vnode_pager_setsize() might sleep waiting for the page after
EOF be unbusied.

Call vnode_pager_setsize() both for the regular and directory vnodes.

MFC r248581:
Initialize the variable to avoid (false) compiler warning about
use of an uninitialized local.
MFC r248815:
Release the v_writecount reference on the vnode in case of error,
before the vnode is vput() in vm_mmap_vnode().
MFC r247832:
Import the likely() compat macro.

MFC r247838:
Correct the r247832.
MFC r247833:
Import the drm_mm_debug_table() function.
MFC r247834:
Import the drm_global references helpers.

MFC r247839 (by dumbbell):
Destroy sx in drm_global_release().
MFC r227293 (by ed):
Mark MALLOC_DEFINEs static that have no corresponding MALLOC_DECLAREs.

This means that their use is restricted to a single C file.
MFC r234177, r234374 (by trasz):
Refactor da(4) to remove one of two code paths used to query capacity
data.
MFC r237478:
Add scsi_extract_sense_ccb() -- wrapper around scsi_extract_sense_len().
It allows to remove number of duplicate checks from several places.
MFC r237689 (by imp):
Add a sysctl to set the cdrom timeout.  Data recovery operations from
a CD or DVD drive with a damaged disc often benefit from a shorter
timeout.  Also, when retries are set to 0, an application is expecting
errors and recovering them so do not print the error into the log.
The number of expected errors can literally be in the hundreds of
thousands which significantly slows data recovery.
MFC r226735 (by pjd):
Simplify disk_alloc().
MFC r226736:
Improve style a bit.
MFC r226737 (by pjd):
Allow upper layers to discover than BIO_DELETE and/or BIO_FLUSH is not
supported by returning EOPNOTSUPP instead of 0 or ENODEV.
MFC r226998, r227004:
Refactor disk disconnection and geom destruction handling sequences.
Do not close/destroy opened consumer directly in case of disconnect. Instead
keep it existing until it will be closed in regular way in response to
upstream provider destruction. Delay geom destruction in the same way.
Previous implementation could destroy consumers still having active
requests and worked only because of global workaround made on GEOM level.
MFC r227015:
Add mutex and two flags to make orphan() call properly asynchronous:
 - delay consumer closing and detaching on orphan() until all I/Os complete;
 - prevent new I/Os submission after orphan() called.
Previous implementation could destroy consumers still having active
requests and worked only because of global workaround made on GEOM level.
MFC r228204:
Close race between geom destruction on g_vfs_close() when softc destroyed
and g_vfs_orphan() call that tries to access softc, intruced at r227015.
MFC r238198 (by trasz):
Fix orphan() methods of several GEOM classes to not assume that there
is an error set on the provider.  With GEOM resizing, class can become
orphaned when it doesn't implement resize() method and the provider size
decreases.