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John Baldwin 5aefb4cbbf Close a race in NFS lookup processing that could result in stale name cache
entries on one client when a directory was renamed on another client.  The
root cause for the stale entry being trusted is that each per-vnode nfsnode
structure has a single 'n_ctime' timestamp used to validate positive name
cache entries.  However, if there are multiple entries for a single vnode,
they all share a single timestamp.  To fix this, extend the name cache
to allow filesystems to optionally store a timestamp value in each name
cache entry.  The NFS clients now fetch the timestamp associated with
each name cache entry and use that to validate cache hits instead of the
timestamps previously stored in the nfsnode.  Another part of the fix is
that the NFS clients now use timestamps from the post-op attributes of
RPCs when adding name cache entries rather than pulling the timestamps out
of the file's attribute cache.  The latter is subject to races with other
lookups updating the attribute cache concurrently.  Some more details:
- Add a variant of nfsm_postop_attr() to the old NFS client that can return
  a vattr structure with a copy of the post-op attributes.
- Handle lookups of "." as a special case in the NFS clients since the name
  cache does not store name cache entries for ".", so we cannot get a
  useful timestamp.  It didn't really make much sense to recheck the
  attributes on the the directory to validate the namecache hit for "."
  anyway.
- ABI compat shims for the name cache routines are present in this commit
  so that it is safe to MFC.

MFC after:	2 weeks
2012-01-20 20:02:01 +00:00
bin Remove unused variables. 2012-01-17 22:17:10 +00:00
cddl Add missing file permission to open(O_CREAT) call. This doesn't really matter 2012-01-04 07:25:10 +00:00
contrib Pull in r148240 from upstream llvm trunk: 2012-01-20 19:18:11 +00:00
crypto Fix a problem whereby a corrupt DNS record can cause named to crash. [11:06] 2011-12-23 15:00:37 +00:00
etc /etc/netstart: remove invocation of dhclient 2012-01-20 17:25:15 +00:00
games Reencode morse.c to UTF-8. This does not make it Unicode aware. 2012-01-15 13:23:01 +00:00
gnu Don't include <sys/timeb.h>. 2012-01-08 12:38:41 +00:00
include Only use the static assertion when __generic is available. 2012-01-17 20:22:10 +00:00
kerberos5 Don't support OpenLDAP during lib32 build. 2011-12-06 12:03:01 +00:00
lib Conditionalize the __floatunsisf and __floatunsidf functions, added in 2012-01-20 14:44:21 +00:00
libexec Remove unneeded dtv variable. 2012-01-17 21:55:20 +00:00
release Add support for the Em command. This restores a missing 'not' in the 2012-01-19 17:29:54 +00:00
rescue -lreadline is not required anymore. 2011-11-29 03:27:09 +00:00
sbin Don't print the nmount(2) provided error message if it is empty. 2012-01-20 12:59:12 +00:00
secure Force linker error when created shared library contains a relocation 2011-12-06 11:28:17 +00:00
share Reflect tunable name change made in r230337. 2012-01-19 20:31:29 +00:00
sys Close a race in NFS lookup processing that could result in stale name cache 2012-01-20 20:02:01 +00:00
tools These tests check whether the compiler evaluates floating-point 2012-01-20 06:57:21 +00:00
usr.bin Map foreign architecture names to FreeBSD naming convention. 2012-01-20 18:55:56 +00:00
usr.sbin Fix warning when compiling with gcc46: 2012-01-20 01:39:26 +00:00
COPYRIGHT Happy 2012 to FreeBSD users in Samoa. 2011-12-31 04:38:04 +00:00
LOCKS Update LOCKS syntax. 2008-06-05 19:47:58 +00:00
MAINTAINERS Farewall, sysinstall! You served us well for many years, but 10.0 is one 2011-10-03 15:13:09 +00:00
Makefile Replace 'chflags' with 'file flags' in a comment, since 'chflags' 2011-11-20 20:05:47 +00:00
Makefile.inc1 Restore functionality to pack several kernels into release. All 2012-01-15 08:36:25 +00:00
Makefile.mips Retire TARGET_ABI. 2011-01-07 20:26:33 +00:00
ObsoleteFiles.inc Remove wtmpcvt(1). 2012-01-13 15:40:49 +00:00
README Add the cddl/ directory. 2010-11-14 11:32:56 +00:00
UPDATING For the mass rc.d changes, add a command line to make the update easier 2012-01-14 23:19:10 +00:00

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

cddl		Various commands and libraries under the Common Development
		and Distribution License.

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.

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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.

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usr.sbin	System administration commands.


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