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authorLinus Torvalds <torvalds@linux-foundation.org>2015-06-23 15:55:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-23 15:55:44 -0700
commitacd53127c4adbd34570b221e7ea1f7fc94aea923 (patch)
tree5e24adc30e91db14bc47ef4287319f38eb1b2108 /Documentation
parentf9d1b5a31ab02208e29631756630739175cdaa02 (diff)
parentc8806b6c9e824f47726f2a9b7fbbe7ebf19306fa (diff)
downloadop-kernel-dev-acd53127c4adbd34570b221e7ea1f7fc94aea923.zip
op-kernel-dev-acd53127c4adbd34570b221e7ea1f7fc94aea923.tar.gz
Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI updates from James Bottomley: "This is the usual grab bag of driver updates (lpfc, hpsa, megaraid_sas, cxgbi, be2iscsi) plus an assortment of minor updates. There is also one new driver: the Cisco snic. The advansys driver has been rewritten to get rid of the warning about converting it to the DMA API, the tape statistics patch got in and finally, there's a resuffle of SCSI header files to separate more cleanly initiator from target mode (and better share the common definitions)" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (156 commits) snic: driver for Cisco SCSI HBA qla2xxx: Fix indentation qla2xxx: Comment out unreachable code fusion: remove dead MTRR code advansys: fix compilation errors and warnings when CONFIG_PCI is not set mptsas: fix depth param in scsi_track_queue_full megaraid: fix irq setup process regression lpfc: Update version to 10.7.0.0 for upstream patch set. lpfc: Fix to drop PLOGIs from fabric node till LOGO processing completes lpfc: Fix scsi task management error message. lpfc: Fix cq_id masking problem. lpfc: Fix scsi prep dma buf error. lpfc: Add support for using block multi-queue lpfc: Devices are not discovered during takeaway/giveback testing lpfc: Fix vport deletion failure. lpfc: Check for active portpeerbeacon. lpfc: Update driver version for upstream patch set 10.6.0.1. lpfc: Change buffer pool empty message to miscellaneous category lpfc: Fix incorrect log message reported for empty FCF record. lpfc: Fix rport leak. ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/sysfs-class-scsi_tape109
-rw-r--r--Documentation/scsi/st.txt59
-rwxr-xr-xDocumentation/target/tcm_mod_builder.py7
3 files changed, 170 insertions, 5 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-scsi_tape b/Documentation/ABI/testing/sysfs-class-scsi_tape
new file mode 100644
index 0000000..9be398b
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-scsi_tape
@@ -0,0 +1,109 @@
+What: /sys/class/scsi_tape/*/stats/in_flight
+Date: Apr 2015
+KernelVersion: 4.2
+Contact: Shane Seymour <shane.seymour@hp.com>
+Description:
+ Show the number of I/Os currently in-flight between the st
+ module and the SCSI mid-layer.
+Users:
+
+
+What: /sys/class/scsi_tape/*/stats/io_ns
+Date: Apr 2015
+KernelVersion: 4.2
+Contact: Shane Seymour <shane.seymour@hp.com>
+Description:
+ Shows the total amount of time spent waiting for all I/O
+ to and from the tape drive to complete. This includes all
+ reads, writes, and other SCSI commands issued to the tape
+ drive. An example of other SCSI commands would be tape
+ movement such as a rewind when a rewind tape device is
+ closed. This item is measured in nanoseconds.
+
+ To determine the amount of time spent waiting for other I/O
+ to complete subtract read_ns and write_ns from this value.
+Users:
+
+
+What: /sys/class/scsi_tape/*/stats/other_cnt
+Date: Apr 2015
+KernelVersion: 4.2
+Contact: Shane Seymour <shane.seymour@hp.com>
+Description:
+ The number of I/O requests issued to the tape drive other
+ than SCSI read/write requests.
+Users:
+
+
+What: /sys/class/scsi_tape/*/stats/read_byte_cnt
+Date: Apr 2015
+KernelVersion: 4.2
+Contact: Shane Seymour <shane.seymour@hp.com>
+Description:
+ Shows the total number of bytes requested from the tape drive.
+ This value is presented in bytes because tape drives support
+ variable length block sizes.
+Users:
+
+
+What: /sys/class/scsi_tape/*/stats/read_cnt
+Date: Apr 2015
+KernelVersion: 4.2
+Contact: Shane Seymour <shane.seymour@hp.com>
+Description:
+ Shows the total number of read requests issued to the tape
+ drive.
+Users:
+
+
+What: /sys/class/scsi_tape/*/stats/read_ns
+Date: Apr 2015
+KernelVersion: 4.2
+Contact: Shane Seymour <shane.seymour@hp.com>
+Description:
+ Shows the total amount of time in nanoseconds waiting for
+ read I/O requests to complete.
+Users:
+
+
+What: /sys/class/scsi_tape/*/stats/write_byte_cnt
+Date: Apr 2015
+KernelVersion: 4.2
+Contact: Shane Seymour <shane.seymour@hp.com>
+Description:
+ Shows the total number of bytes written to the tape drive.
+ This value is presented in bytes because tape drives support
+ variable length block sizes.
+Users:
+
+
+What: /sys/class/scsi_tape/*/stats/write_cnt
+Date: Apr 2015
+KernelVersion: 4.2
+Contact: Shane Seymour <shane.seymour@hp.com>
+Description:
+ Shows the total number of write requests issued to the tape
+ drive.
+Users:
+
+
+What: /sys/class/scsi_tape/*/stats/write_ms
+Date: Apr 2015
+KernelVersion: 4.2
+Contact: Shane Seymour <shane.seymour@hp.com>
+Description:
+ Shows the total amount of time in nanoseconds waiting for
+ write I/O requests to complete.
+Users:
+
+
+What: /sys/class/scsi_tape/*/stats/resid_cnt
+Date: Apr 2015
+KernelVersion: 4.2
+Contact: Shane Seymour <shane.seymour@hp.com>
+Description:
+ Shows the number of times we found that a residual >0
+ was found when the SCSI midlayer indicated that there was
+ an error. For reads this may be a case of someone issuing
+ reads greater than the block size.
+Users:
diff --git a/Documentation/scsi/st.txt b/Documentation/scsi/st.txt
index 0d5bdb1..f29fa55 100644
--- a/Documentation/scsi/st.txt
+++ b/Documentation/scsi/st.txt
@@ -151,6 +151,65 @@ A link named 'tape' is made from the SCSI device directory to the class
directory corresponding to the mode 0 auto-rewind device (e.g., st0).
+SYSFS AND STATISTICS FOR TAPE DEVICES
+
+The st driver maintains statistics for tape drives inside the sysfs filesystem.
+The following method can be used to locate the statistics that are
+available (assuming that sysfs is mounted at /sys):
+
+1. Use opendir(3) on the directory /sys/class/scsi_tape
+2. Use readdir(3) to read the directory contents
+3. Use regcomp(3)/regexec(3) to match directory entries to the extended
+ regular expression "^st[0-9]+$"
+4. Access the statistics from the /sys/class/scsi_tape/<match>/stats
+ directory (where <match> is a directory entry from /sys/class/scsi_tape
+ that matched the extended regular expression)
+
+The reason for using this approach is that all the character devices
+pointing to the same tape drive use the same statistics. That means
+that st0 would have the same statistics as nst0.
+
+The directory contains the following statistics files:
+
+1. in_flight - The number of I/Os currently outstanding to this device.
+2. io_ns - The amount of time spent waiting (in nanoseconds) for all I/O
+ to complete (including read and write). This includes tape movement
+ commands such as seeking between file or set marks and implicit tape
+ movement such as when rewind on close tape devices are used.
+3. other_cnt - The number of I/Os issued to the tape drive other than read or
+ write commands. The time taken to complete these commands uses the
+ following calculation io_ms-read_ms-write_ms.
+4. read_byte_cnt - The number of bytes read from the tape drive.
+5. read_cnt - The number of read requests issued to the tape drive.
+6. read_ns - The amount of time (in nanoseconds) spent waiting for read
+ requests to complete.
+7. write_byte_cnt - The number of bytes written to the tape drive.
+8. write_cnt - The number of write requests issued to the tape drive.
+9. write_ns - The amount of time (in nanoseconds) spent waiting for write
+ requests to complete.
+10. resid_cnt - The number of times during a read or write we found
+ the residual amount to be non-zero. This should mean that a program
+ is issuing a read larger thean the block size on tape. For write
+ not all data made it to tape.
+
+Note: The in_flight value is incremented when an I/O starts the I/O
+itself is not added to the statistics until it completes.
+
+The total of read_cnt, write_cnt, and other_cnt may not total to the same
+value as iodone_cnt at the device level. The tape statistics only count
+I/O issued via the st module.
+
+When read the statistics may not be temporally consistent while I/O is in
+progress. The individual values are read and written to atomically however
+when reading them back via sysfs they may be in the process of being
+updated when starting an I/O or when it is completed.
+
+The value shown in in_flight is incremented before any statstics are
+updated and decremented when an I/O completes after updating statistics.
+The value of in_flight is 0 when there are no I/Os outstanding that are
+issued by the st driver. Tape statistics do not take into account any
+I/O performed via the sg device.
+
BSD AND SYS V SEMANTICS
The user can choose between these two behaviours of the tape driver by
diff --git a/Documentation/target/tcm_mod_builder.py b/Documentation/target/tcm_mod_builder.py
index 2ba71ce..6085e1f 100755
--- a/Documentation/target/tcm_mod_builder.py
+++ b/Documentation/target/tcm_mod_builder.py
@@ -503,11 +503,8 @@ def tcm_mod_dump_fabric_ops(proto_ident, fabric_mod_dir_var, fabric_mod_name):
buf += "#include <linux/string.h>\n"
buf += "#include <linux/ctype.h>\n"
buf += "#include <asm/unaligned.h>\n"
- buf += "#include <scsi/scsi.h>\n"
- buf += "#include <scsi/scsi_host.h>\n"
- buf += "#include <scsi/scsi_device.h>\n"
- buf += "#include <scsi/scsi_cmnd.h>\n"
- buf += "#include <scsi/libfc.h>\n\n"
+ buf += "#include <scsi/scsi_common.h>\n"
+ buf += "#include <scsi/scsi_proto.h>\n"
buf += "#include <target/target_core_base.h>\n"
buf += "#include <target/target_core_fabric.h>\n"
buf += "#include <target/target_core_configfs.h>\n\n"
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