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  1. 18 11月, 2016 5 次提交
  3. 27 7月, 2015 1 次提交
  5. 20 11月, 2014 1 次提交
    • M
      zfcp: auto port scan resiliency · 18f87a67
      由 Martin Peschke 提交于 
      This patch improves the Fibre Channel port scan behaviour of the zfcp lldd.
Without it the zfcp device driver may churn up the storage area network by
excessive scanning and scan bursts, particularly in big virtual server
environments, potentially resulting in interference of virtual servers and
reduced availability of storage connectivity.

The two main issues as to the zfcp device drivers automatic port scan in
virtual server environments are frequency and simultaneity.
On the one hand, there is no point in allowing lots of ports scans
in a row. It makes sense, though, to make sure that a scan is conducted
eventually if there has been any indication for potential SAN changes.
On the other hand, lots of virtual servers receiving the same indication
for a SAN change had better not attempt to conduct a scan instantly,
that is, at the same time.

Hence this patch has a two-fold approach for better port scanning:
the introduction of a rate limit to amend frequency issues, and the
introduction of a short random backoff to amend simultaneity issues.
Both approaches boil down to deferred port scans, with delays
comprising parts for both approaches.

The new port scan behaviour is summarised best by:

                                               NEW:    NEW:
                          no_auto_port_rescan  random  rate    flush
                                               backoff limit   =wait

adapter resume/thaw       yes                  yes     no      yes*
adapter online (user)     no                   yes     no      yes*
port rescan (user)        no                   no      no      yes
adapter recovery (user)   yes                  yes     yes     no
adapter recovery (other)  yes                  yes     yes     no
incoming ELS              yes                  yes     yes     no
incoming ELS lost         yes                  yes     yes     no

Implementation is straight-forward by converting an existing worker to
a delayed worker. But care is needed whenever that worker is going to be
flushed (in order to make sure work has been completed), since a flush
operation cancels the timer set up for deferred execution (see * above).

There is a small race window whenever a port scan work starts
running up to the point in time of storing the time stamp for that port
scan. The impact is negligible. Closing that gap isn't trivial, though, and
would the destroy the beauty of a simple work-to-delayed-work conversion.
Signed-off-by: NMartin Peschke <mpeschke@linux.vnet.ibm.com>
Signed-off-by: NSteffen Maier <maier@linux.vnet.ibm.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
      18f87a67
  7. 01 6月, 2013 1 次提交
  9. 24 9月, 2012 1 次提交
    • S
      [SCSI] zfcp: No automatic port_rescan on events · 43f60cbd
      由 Steffen Maier 提交于 
      In FC fabrics with large zones, the automatic port_rescan on incoming ELS
and any adapter recovery can cause quite some traffic at the very same
time, especially if lots of Linux images share an HBA, which is common on
s390. This can cause trouble and failures. Fix this by making such port
rescans dependent on a user configurable module parameter.

The following unconditional automatic port rescans remain as is:
On setting an adapter online and
on manual user-triggered writes to the sysfs attribute port_rescan.
Signed-off-by: NSteffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>
      43f60cbd
  11. 20 7月, 2012 1 次提交
    • H
      s390/comments: unify copyright messages and remove file names · a53c8fab
      由 Heiko Carstens 提交于 
      Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
      a53c8fab
  13. 26 2月, 2011 4 次提交
  15. 22 12月, 2010 2 次提交
  17. 17 9月, 2010 1 次提交
  19. 28 7月, 2010 1 次提交
  21. 03 5月, 2010 1 次提交
  23. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      由 Tejun Heo 提交于 
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

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: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  25. 18 2月, 2010 1 次提交
  27. 09 2月, 2010 1 次提交
  29. 18 1月, 2010 3 次提交
  31. 05 12月, 2009 10 次提交
  33. 22 10月, 2009 1 次提交
    • C
      [SCSI] zfcp: Handle WWPN mismatch in PLOGI payload · 934aeb58
      由 Christof Schmitt 提交于 
      For ports, zfcp gets the DID from the FC nameserver and tries to open
the port. If the open succeeds, zfcp compares the WWPN from the
nameserver with the WWPN in the PLOGI payload. In case of a mismatch,
zfcp assumes that the DID of the port just changed and we opened the
wrong port. This means that zfcp has to forget the DID, lookup the DID
again and retry.

This error case had a problem that zfcp forgets the DID, but never
looks up a new one, stalling the ERP in this case. Fix this by
triggering the DID lookup and properly exit from the ERP. The DID
lookup will trigger a new ERP action.

Also ensure when trying to open the port again with the new DID, first
close the open port, even in the NOESC case.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>
      934aeb58
  35. 05 9月, 2009 4 次提交