901b894af5
When we fail to send a FSF request in 'zfcp_fsf_req_send()' when calling
'zfcp_qdio_send()' we try to remove the request object from our internal
hash table again to prevent keeping a stale memory reference. This removal
might still - very much theoretically - fail.
To store some evidence of when this happens add a new trace record for
this case; tag: 'fsrsrmf'.
We reuse the 'ZFCP_DBF_HBA_RES' trace ID for this, but mark all fields
other then the request ID with ~0, to make fairly obvious that these are
invalid values. This faking has to be done because we don't have a valid
request object at this point, and can not safely access any of the memory
of the old object - we just failed to find it in our hash table, so it
might be gone already.
Here is an example of a decoded trace record:
Timestamp : 2023-02-17-13:09:12:748140
Area : HBA
Subarea : 1
Level : -
Exception : 000003ff7ff500c2
CPU ID : 0011
Caller : 0x0
Record ID : 1
Tag : fsrsrmf
Request ID : 0x0000000080126ab6
Request status : 0xffffffff
FSF cmnd : 0xffffffff
FSF sequence no: 0xffffffff
FSF issued : 2042-09-18-01:53:47:370495
FSF stat : 0xffffffff
FSF stat qual : ffffffff ffffffff ffffffff ffffffff
Prot stat : 0xffffffff
Prot stat qual : ffffffff ffffffff ffffffff ffffffff
Port handle : 0xffffffff
LUN handle : 0xffffffff
This provides at least some basic evidence that this event happened, and
what object was affected.
Link: https://lore.kernel.org/r/99b8246b2d71b63fa4f9c56333e2037502f7f5af.1677000450.git.bblock@linux.ibm.com
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
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.