linux-toradex.git/fs/lockd/clntproc.c, branch v3.2.55

LOCKD: Ensure that nlmclnt_block resets block->b_status after a server reboot

2013-05-13T14:02:22+00:00

commit 1dfd89af8697a299e7982ae740d4695ecd917eef upstream.

After a server reboot, the reclaimer thread will recover all the existing
locks. For locks that are blocked, however, it will change the value
of block->b_status to nlm_lck_denied_grace_period in order to signal that
they need to wake up and resend the original blocking lock request.

Due to a bug, however, the block->b_status never gets reset after the
blocked locks have been woken up, and so the process goes into an
infinite loop of resends until the blocked lock is satisfied.

Reported-by: Marc Eshel 
Signed-off-by: Trond Myklebust 
Signed-off-by: Ben Hutchings

NLM: Ensure that we resend all pending blocking locks after a reclaim

2013-03-06T03:24:05+00:00

commit 666b3d803a511fbc9bc5e5ea8ce66010cf03ea13 upstream.

Currently, nlmclnt_lock will break out of the for(;;) loop when
the reclaimer wakes up the blocking lock thread by setting
nlm_lck_denied_grace_period. This causes the lock request to fail
with an ENOLCK error.
The intention was always to ensure that we resend the lock request
after the grace period has expired.

Reported-by: Wangyuan Zhang 
Signed-off-by: Trond Myklebust 
Signed-off-by: Ben Hutchings

lockd: properly convert be32 values in debug messages

2011-07-12T17:40:26+00:00

lockd: server returns status 50331648
it's quite hard to understand that number in this message is 3 in big endian

Signed-off-by: Vasily Averin 
Signed-off-by: Trond Myklebust

NLM: Don't hang forever on NLM unlock requests

2011-06-15T15:24:27+00:00

If the NLM daemon is killed on the NFS server, we can currently end up
hanging forever on an 'unlock' request, instead of aborting. Basically,
if the rpcbind request fails, or the server keeps returning garbage, we
really want to quit instead of retrying.

Tested-by: Vasily Averin 
Signed-off-by: Trond Myklebust 
Cc: stable@kernel.org

lockd: Create client-side nlm_host cache

2010-12-16T17:37:26+00:00

NFS clients don't need the garbage collection processing that is
performed on nlm_host structures.  The client picks up an nlm_host at
mount time and holds a reference to it until the file system is
unmounted.

Servers, on the other hand, don't have a precise way to tell when an
nlm_host is no longer being used, so zero refcount nlm_host entries
are left to expire in the cache after a time.

Basically there's nothing holding a reference to an nlm_host between
individual server-side NLM requests, but we can't afford the expense
of recreating them for every new NLM request from a client.  The
nlm_host cache adds some lifetime hysteresis to entries in the cache
so the next time a particular nlm_host is needed, it's likely to be
discovered by a lookup rather than created from whole cloth.

With the new implementation, client nlm_host cache items are no longer
garbage collected, and are destroyed directly by a new release
function specialized for client entries, nlmclnt_release_host().  They
are cached in their own data structure, and have their own lookup
logic, simplified and specialized for client nlm_host entries.

However, the client nlm_host cache still shares reboot recovery logic
with the server nlm_host cache.  The NSM "peer rebooted" downcall for
clients and servers still come through the same RPC call.  This is a
legacy formal API that would be difficult to alter, and besides, the
user space NSM implementation can't tell the difference between peers
that are clients or servers.

For this reason, the client cache continues to share the
nlm_host_mutex (and reboot recovery logic) with the server cache.

Signed-off-by: Chuck Lever 
Signed-off-by: Trond Myklebust

lockd: Split nlm_release_call()

2010-12-16T17:37:26+00:00

The nlm_release_call() function is invoked from both the server and
the client side.  We're about to introduce a distinct server- and
client-side nlm_release_host(), so nlm_release_call() must first be
split into a client-side and a server-side version.

Signed-off-by: Chuck Lever 
Signed-off-by: Trond Myklebust

BKL: remove extraneous #include

2010-11-17T16:59:32+00:00

The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Linus Torvalds

lockd: Remove BKL from the client

2010-09-22T13:50:35+00:00

This patch removes all calls to lock_kernel() from the client.  This patch
should be applied after the "fs/lock.c prepare for BKL removal" patch submitted
by Arnd Bergmann on September 18.

Signed-off-by: Bryan Schumaker 
Signed-off-by: Trond Myklebust

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32+00:00

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo 
Guess-its-ok-by: Christoph Lameter 
Cc: Ingo Molnar 
Cc: Lee Schermerhorn

const: make file_lock_operations const

2009-09-22T14:17:25+00:00

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds