FreeBSD src
Go to file
Kip Macy 62fa227ccd Asynchronously release vnodes to avoid blocking on range locks when calling back in to zfs.
This is based on a fix that went in to opensolaris on March 9th. However, it uses a dedicated
thread instead of a Solaris' taskq to avoid doing a blocking memory allocation with the vnode
interlock held.

This fixes a long-time deadlock in ZFS. This is not, strictly speaking, an LOR. The spa_zio
thread releases a vnode, this calls in to vn_reclaim which in turn needs to acquire range locks
to sync dirty data out to disk. The range locks are already held by a user-level process waiting
on a condition variable that it the process is waiting on a spa_zio thread to signal it on. The
process could not be signalled because the spa_zio thread could not proceed.

The nature of this problem was not apparent due to ZFS locks opting out of witness which meant
that DDB did not know about the locks that were held by ZFS.

Reviewed by:	pjd
MFC after:	7 days
2009-05-07 20:28:06 +00:00
bin Implement ^T support for rm: now it will report the next file it 2009-04-29 18:08:18 +00:00
cddl Switch over to gnu99 compilation on default for userland. 2009-03-14 17:55:16 +00:00
contrib This belongs in //svn.freebsd.org/base/vendor/file/dist now. 2009-05-04 00:42:15 +00:00
crypto Don't leak information via uninitialized space in db(3) records. [09:07] 2009-04-22 14:07:14 +00:00
etc Added (pre|post)(start|stop) jail hooks. These can be used to run 2009-04-28 09:45:32 +00:00
games Too good to pass. 2009-03-06 13:24:54 +00:00
gnu Fix build breakage due to the interplay between r189801 and r189824. 2009-03-14 22:50:03 +00:00
include Revert r190943, since the problem in ports seems to be fixed now. 2009-04-17 14:19:18 +00:00
kerberos5 Add strndup(3) prototype to string.h. 2008-12-08 21:04:24 +00:00
lib Add tcsetsid(3). 2009-05-07 13:49:48 +00:00
libexec Prefer <sys/param.h> to <machine/param.h> for the definition of 2009-04-20 10:35:50 +00:00
release fix various build errors (missing or wrong return types for 2009-04-27 16:57:19 +00:00
rescue Libarchive is sprouting dependencies on libmd and libcrypto. 2009-04-18 06:01:55 +00:00
sbin Do no spam the ifconfig output for the aggregated interface with 'laggdev laggX'. 2009-04-30 14:31:52 +00:00
secure Enable getaudit_addr(2) for sshd again. This will un-break the subject 2008-11-30 15:35:24 +00:00
share Update example with feedback from thompsa@. 2009-05-07 16:31:50 +00:00
sys Asynchronously release vnodes to avoid blocking on range locks when calling back in to zfs. 2009-05-07 20:28:06 +00:00
tools A script for plucking packages and their runtime dependencies for 2009-04-19 18:23:23 +00:00
usr.bin Add my birthday 2009-05-07 15:32:13 +00:00
usr.sbin fix grammar... 2009-05-06 20:07:28 +00:00
COPYRIGHT Bump the odometer of the years. A little early this year for 7.1R. 2008-12-30 04:46:25 +00:00
LOCKS Update LOCKS syntax. 2008-06-05 19:47:58 +00:00
MAINTAINERS Replace anholt with myself as drm maintainer. 2009-03-20 18:51:13 +00:00
Makefile Add a new world named 'mips' to our universe. 2009-04-01 17:11:50 +00:00
Makefile.inc1 Revert c190007 at the request of Ruslan. It was not correct because 2009-04-05 00:24:49 +00:00
ObsoleteFiles.inc usbdevs(8) is not obsoleted, just temporarily disconnected from the build 2009-04-18 22:16:46 +00:00
README Simply running ``make world'' will bomb unless you dig up the 2006-06-07 03:33:48 +00:00
UPDATING Permit buiding kernels with options VIMAGE, restricted to only a single 2009-04-30 13:36:26 +00:00

This is the top level of the FreeBSD source directory.  This file
was last revised on:
$FreeBSD$

For copyright information, please see the file COPYRIGHT in this
directory (additional copyright information also exists for some
sources in this tree - please see the specific source directories for
more information).

The Makefile in this directory supports a number of targets for
building components (or all) of the FreeBSD source tree, the most
commonly used one being ``world'', which rebuilds and installs
everything in the FreeBSD system from the source tree except the
kernel, the kernel-modules and the contents of /etc.  The ``world''
target should only be used in cases where the source tree has not
changed from the currently running version.  See:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html
for more information, including setting make(1) variables.

The ``buildkernel'' and ``installkernel'' targets build and install
the kernel and the modules (see below).  Please see the top of
the Makefile in this directory for more information on the
standard build targets and compile-time flags.

Building a kernel is a somewhat more involved process, documentation
for which can be found at:
   http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html
And in the config(8) man page.
Note: If you want to build and install the kernel with the
``buildkernel'' and ``installkernel'' targets, you might need to build
world before.  More information is available in the handbook.

The sample kernel configuration files reside in the sys/<arch>/conf
sub-directory (assuming that you've installed the kernel sources), the
file named GENERIC being the one used to build your initial installation
kernel.  The file NOTES contains entries and documentation for all possible
devices, not just those commonly used.  It is the successor of the ancient
LINT file, but in contrast to LINT, it is not buildable as a kernel but a
pure reference and documentation file.


Source Roadmap:
---------------
bin		System/user commands.

contrib		Packages contributed by 3rd parties.

crypto		Cryptography stuff (see crypto/README).

etc		Template files for /etc.

games		Amusements.

gnu		Various commands and libraries under the GNU Public License.
		Please see gnu/COPYING* for more information.

include		System include files.

kerberos5	Kerberos5 (Heimdal) package.

lib		System libraries.

libexec		System daemons.

release		Release building Makefile & associated tools.

rescue		Build system for statically linked /rescue utilities.

sbin		System commands.

secure		Cryptographic libraries and commands.

share		Shared resources.

sys		Kernel sources.

tools		Utilities for regression testing and miscellaneous tasks.

usr.bin		User commands.

usr.sbin	System administration commands.


For information on synchronizing your source tree with one or more of
the FreeBSD Project's development branches, please see:

  http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html