srp_remote_ports

Field	Value
Subsystem	SCSI RDMA Protocol transport, remote-port side; the SRP transport attributes are selected as `SCSI_SRP_ATTRS` (fetched `srp-Kconfig`: `INFINIBAND_SRP` “select SCSI_SRP_ATTRS”); implementation file not in cached tree
Config gate	`CONFIG_SCSI_SRP_ATTRS` – verified indirectly via the fetched drivers/infiniband/ulp/srp Kconfig, where `config INFINIBAND_SRP` (depends on SCSI && INFINIBAND_ADDR_TRANS) selects it
ABI documentation	`Documentation/ABI/stable/sysfs-transport-srp`
Since	2.6.24 (`port_id`, `roles`); 3.7 (`delete`); 3.13 (`dev_loss_tmo`, `fast_io_fail_tmo`, `reconnect_delay`, `state`)
Live (5.10.134 host)	class absent: no `srp_remote_ports` row in the cached live enumeration of 46 classes
Ledger ID	SYSC-srp_remote_ports

What it represents

One directory port-<h>:<n> per remote SRP target port that an SRP initiator (ib_srp) has encountered. The class holds the transport-layer view of that remote port: identity (port_id, roles), connection health (state), and the error-recovery timers that decide how fast I/O fails and how fast the target is reconnected or dropped. This is the SRP analogue of the FC remote-port class; the initiator-side control (login) lives in /sys/class/infiniband_srp instead.

Relationship to the device model

Remote ports sit between the ib_srp initiator (srp-<hca>-<port> devices under infiniband_srp) and the SCSI hosts they create: each port-<h>:<n> drives SCSI hosts whose connection parameters (dgid, ioc_guid, req_lim, …) are exposed under /sys/class/scsi_host and documented in the same stable ABI file. LUNs imported through the port appear in the usual SCSI/block trees; delete is the documented way to tear that whole import down.

Attributes

Attribute	R/W	Unit/format	Conditional?	Source
`port-<h>:<n>/port_id`	RO	16-byte local SRP port identifier in hexadecimal, colon-separated	always	ABI stable `sysfs-transport-srp`
`port-<h>:<n>/roles`	RO	“SRP Initiator” or “SRP Target”	always	ABI stable `sysfs-transport-srp`
`port-<h>:<n>/state`	RO	running, blocked, fail-fast, or lost	always	ABI stable `sysfs-transport-srp`
`port-<h>:<n>/delete`	WO	write instructs disconnect and removal of all imported LUNs	always	ABI stable `sysfs-transport-srp`
`port-<h>:<n>/dev_loss_tmo`	W	seconds before target removal after transport error; 0 = immediate; “off” disables	always	ABI stable `sysfs-transport-srp`
`port-<h>:<n>/fast_io_fail_tmo`	W	seconds before I/O is failed after transport error; 0 = immediate; “off” disables	always	ABI stable `sysfs-transport-srp`
`port-<h>:<n>/reconnect_delay`	W	seconds between reconnect attempts; “off” disables time-based reconnecting	always	ABI stable `sysfs-transport-srp`

Safety and writes

Reads are safe. The three timers are multipath-critical: dev_loss_tmo and fast_io_fail_tmo shape SCSI error handling, and the state machine (blocked -> fail-fast -> lost) is exactly what multipath tools watch. delete is the destructive one – it disconnects from the target and removes every LUN imported from it, so writing it on an in-use path will take file systems down. The ABI text describes writes to the timers but does not state their readability (not verified).

References

Documentation/ABI/stable/sysfs-transport-srp (cached copy; seven What: entries)
ABI doc online
Fetched srp-Kconfig (drivers/infiniband/ulp/srp Kconfig, select SCSI_SRP_ATTRS)
Companion pages: infiniband_srp, scsi_host
sysfs overview, ledger
Ledger row SYSC-srp_remote_ports