/sys/class/fc_remote_ports
| Field | Value |
|---|---|
| Subsystem | Fibre Channel SCSI transport class, remote-port side (FPIN statistics view); implementation file not in cached tree |
| Config gate | not verifiable from the cached tree: the ABI entries name no Kconfig symbol and no FC transport Kconfig is cached (not verified) |
| ABI documentation | Documentation/ABI/testing/sysfs-class-fc_remote_ports |
| Since | not stated in the ABI entries (dated July 2020) |
| Live (5.10.134 host) | class absent: no fc_remote_ports row in the cached live enumeration of 46 classes |
| Ledger ID | SYSC-fc_remote_ports |
What it represents
One directory rport-X:Y-Z per remote Fibre Channel port discovered by an FC host: the SCSI transport’s representation of target-side FC ports (and, in general, remote FC entities the LLDD reports). The cached ABI documentation covers only the FPIN statistics group added in July 2020: three counters per remote port for fabric performance impact notification (FPIN) events – congestion notification, link integrity errors, and delivery-related errors – recorded by the F_Port/Nx_Port. The X:Y-Z name components (scsi host, channel, target id) follow the SCSI remote-port naming used across transport classes. The full per-rport attribute set of the FC transport is not in the cached tree and is not listed here.
Relationship to the device model
Remote ports belong to an fc_host (hostX under /sys/class/fc_host, same hostX namespace as /sys/class/scsi_host); SCSI targets and LUNs hang off them in the SCSI device tree. The statistics group mirrors the per-host one in sysfs-class-fc_host, so host-side and port-side FPIN counters can be compared. Traffic tagging for these ports is administered via the fc class singleton (fc_udev_device/appid_store).
Attributes
All documented attributes are read-only counters.
| Attribute | R/W | Unit/format | Conditional? | Source |
|---|---|---|---|---|
rport-X:Y-Z/statistics/fpin_cn_yyy | RO | count of congestion notification FPIN events | FPIN-capable drivers | ABI testing sysfs-class-fc_remote_ports |
rport-X:Y-Z/statistics/fpin_li_yyy | RO | count of link integrity error FPIN events | FPIN-capable drivers | ABI testing sysfs-class-fc_remote_ports |
rport-X:Y-Z/statistics/fpin_dn_yyy | RO | count of delivery-related error FPIN events | FPIN-capable drivers | ABI testing sysfs-class-fc_remote_ports |
Safety and writes
Reads are safe; no writes are documented. Port-level FPIN counters localize a fabric problem to one target path: fpin_li spikes point at the physical path to that port, fpin_cn at congestion the fabric reports for it. Per the ABI description block, events are “reported using fabric performance impact notification (FPIN) event”, so presence of the files depends on driver/fabric FPIN support; absence on older or non-FPIN LLDDs is expected.
References
Documentation/ABI/testing/sysfs-class-fc_remote_ports(cached copy; three What: entries)- ABI doc online
- Companion pages: fc_host, fc, srp_remote_ports
- sysfs overview, ledger
- Ledger row SYSC-fc_remote_ports