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Steffen Maier 975171b446 scsi: zfcp: fix capping of unsuccessful GPN_FT SAN response trace records
v4.9 commit aceeffbb59 ("zfcp: trace full payload of all SAN records
(req,resp,iels)") fixed trace data loss of 2.6.38 commit 2c55b750a8
("[SCSI] zfcp: Redesign of the debug tracing for SAN records.")
necessary for problem determination, e.g. to see the
currently active zone set during automatic port scan.

While it already saves space by not dumping any empty residual entries
of the large successful GPN_FT response (4 pages), there are seldom cases
where the GPN_FT response is unsuccessful and likely does not have
FC_NS_FID_LAST set in fp_flags so we did not cap the trace record.
We typically see such case for an initiator WWPN, which is not in any zone.

Cap unsuccessful responses to at least the actual basic CT_IU response
plus whatever fits the SAN trace record built-in "payload" buffer
just in case there's trailing information
of which we would at least see the existence and its beginning.

In order not to erroneously cap successful responses, we need to swap
calling the trace function and setting the CT / ELS status to success (0).

Example trace record pair formatted with zfcpdbf:

Timestamp      : ...
Area           : SAN
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1
Tag            : fssct_1
Request ID     : 0x<request_id>
Destination ID : 0x00fffffc
SAN req short  : 01000000 fc020000 01720ffc 00000000
                 00000008
SAN req length : 20
|
Timestamp      : ...
Area           : SAN
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 2
Tag            : fsscth2
Request ID     : 0x<request_id>
Destination ID : 0x00fffffc
SAN resp short : 01000000 fc020000 80010000 00090700
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
SAN resp length: 16384
San resp info  : 01000000 fc020000 80010000 00090700
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]
                 00000000 00000000 00000000 00000000 [trailing info]

The fix saves all but one of the previously associated 64 PAYload trace
record chunks of size 256 bytes each.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: aceeffbb59 ("zfcp: trace full payload of all SAN records (req,resp,iels)")
Fixes: 2c55b750a8 ("[SCSI] zfcp: Redesign of the debug tracing for SAN records.")
Cc: <stable@vger.kernel.org> #2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-08-10 19:36:55 -04:00
arch Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-08-06 11:52:01 -07:00
block blk-mq: map queues to all present CPUs 2017-07-24 10:01:31 -06:00
certs modsign: add markers to endif-statements in certs/Makefile 2017-07-14 11:01:37 +10:00
crypto crypto: authencesn - Fix digest_null crash 2017-07-18 17:01:11 +08:00
Documentation media fixes for v4.13-rc2 2017-08-05 14:09:26 -07:00
drivers scsi: zfcp: fix capping of unsuccessful GPN_FT SAN response trace records 2017-08-10 19:36:55 -04:00
firmware firmware/Makefile: force recompilation if makefile changes 2017-05-08 17:15:10 -07:00
fs A large number of ext4 bug fixes and cleanups for v4.13 2017-08-06 12:31:17 -07:00
include scsi: fc: start decoupling fc_block_scsi_eh from scsi_cmnd 2017-08-07 14:04:02 -04:00
init random: do not ignore early device randomness 2017-07-12 16:26:00 -07:00
ipc ipc: add missing container_of()s for randstruct 2017-08-02 17:16:12 -07:00
kernel Fix compat_sys_sigpending breakage 2017-08-06 11:48:27 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-07-31 22:36:42 -07:00
mm mm: take memory hotplug lock within numa_zonelist_order_handler() 2017-08-02 17:16:11 -07:00
net A bunch of fixes and follow-ups for -rc1 Luminous patches: issues with 2017-08-04 10:15:11 -07:00
samples samples/bpf: fix bpf tunnel cleanup 2017-07-31 22:02:47 -07:00
scripts DeviceTree fixes for 4.13: 2017-07-28 17:21:41 -07:00
security Now that IPC and other changes have landed, enable manual markings for 2017-07-19 08:55:18 -07:00
sound ASoC: Fixes for v4.13 2017-08-02 17:11:45 +02:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-07-31 22:36:42 -07:00
usr ramfs: clarify help text that compression applies to ramfs as well as legacy ramdisk. 2017-07-06 16:24:30 -07:00
virt KVM/ARM Fixes for v4.13-rc4 2017-08-03 17:59:58 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap power supply and reset changes for the v4.12 series (part 2) 2017-05-12 12:02:21 -07:00
COPYING
CREDITS avr32: remove support for AVR32 architecture 2017-05-01 09:27:15 +02:00
Kbuild kbuild: Consolidate header generation from ASM offset information 2017-04-13 05:43:37 +09:00
Kconfig
MAINTAINERS MAINTAINERS: Add myself to S390 ZFCP DRIVER as a co-maintainer 2017-08-07 14:04:03 -04:00
Makefile Linux 4.13-rc4 2017-08-06 18:44:49 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.