Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Don't specify a resid parameter if we're just going to ignore it. Instead,
let vn_rdwr() check for short reads.

MFC after: 3 days
Sponsored by: EMC / Isilon Storage Division

Remove unnecessary checks for a return value of NULL from M_WAITOK
allocations.

MFC after: 3 days

Free the zlib stream after expanding a compressed CTF section.

Note that this memory would only be leaked once, since CTF info for a kld
file is cached after the first access.

MFC after: 3 days

Remove the support for using non-mpsafe filesystem modules.

In particular, do not lock Giant conditionally when calling into the
filesystem module, remove the VFS_LOCK_GIANT() and related
macros. Stop handling buffers belonging to non-mpsafe filesystems.

The VFS_VERSION is bumped to indicate the interface change which does
not result in the interface signatures changes.

Conducted and reviewed by: attilio
Tested by: pho

Fix found places where uio_resid is truncated to int.

Add the sysctl debug.iosize_max_clamp, enabled by default. Setting the
sysctl to zero allows to perform the SSIZE_MAX-sized i/o requests from
the usermode.

Discussed with: bde, das (previous versions)
MFC after: 1 month

The in-kernel CTF parser caches the result of its first attempt to parse
CTF data from a module. On subsequent attempts to retrieve CTF data for
a module, return an error if there no CTF data.

This fixes a panic if you try to enable fbt probes on a module with CTF
data twice.

Submitted by: Paul Ambrose (ambrosehua AT gmail DOT com)
MFC after: 3 days

Return proper errno when we hit error when doing sanity check.
This fixes dtrace crashes when module is not compiled with CTF
data.

Submitted by: Paul Ambrose ambrosehua at gmail.com
MFC after: 1 week

Add the CTF source file which gets shared with link_elf.c and link_elf_obj.c.