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| author | Benjamin Block <bblock@linux.ibm.com> | 2019-10-25 19:12:44 +0300 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2019-10-29 05:16:14 +0300 |
| commit | 7e418833e68948cb9ed15262889173b7db2960cb (patch) | |
| tree | 7a61e483bb7f76d6564a9fbfe6e18d6707af8133 /drivers/s390/scsi/zfcp_def.h | |
| parent | 92953c6e0aa77d4febcca6dd691e8192910c8a28 (diff) | |
| download | linux-7e418833e68948cb9ed15262889173b7db2960cb.tar.xz | |
scsi: zfcp: diagnostics buffer caching and use for exchange port data
The FCP channel exposes two central interfaces to receive information about
the local FCP-Adapter/-Port: Exchange Port and Exchange Config Data. Using
these commands can negatively impact the adapter if we allow them to be
sent at a very high rate.
The later parts of this patchset will introduce new user-interfaces to
receive more diagnostics from the adapter. To prevent any negative impact
from using those, this patch adds a simple caching-mechanism that will
prevent a malicious/faulty userspace-application from generating an
abnormal high amount of Exchange Port/Config Data traffic.
Relevant diagnostic data that is received via Exchange Config/Port Data is
cached in buffers associated with the corresponding adapter-struct. Each
buffer is associated with a timestamp that signals how old the data is,
and, added via a following patch in this series, lets userspace-interfaces
determine when the data is too old and needs to be updated.
Buffer-updates are made during the normal response path of the
corresponding command. With this patch only the output of the Exchange Port
Data command is captured.
Link: https://lore.kernel.org/r/054ca020ce0a53dc0d9176428bea373898944e6a.1572018130.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/s390/scsi/zfcp_def.h')
| -rw-r--r-- | drivers/s390/scsi/zfcp_def.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h index f5acdb67442e..8cc0eefe4ccc 100644 --- a/drivers/s390/scsi/zfcp_def.h +++ b/drivers/s390/scsi/zfcp_def.h @@ -4,7 +4,7 @@ * * Global definitions for the zfcp device driver. * - * Copyright IBM Corp. 2002, 2017 + * Copyright IBM Corp. 2002, 2018 */ #ifndef ZFCP_DEF_H @@ -198,6 +198,7 @@ struct zfcp_adapter { struct device_dma_parameters dma_parms; struct zfcp_fc_events events; unsigned long next_port_scan; + struct zfcp_diag_adapter *diagnostics; }; struct zfcp_port { |