'\" t
.\"     Title: fc_eh_timed_out
.\"    Author: 
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: September 2017
.\"    Manual: SCSI mid layer
.\"    Source: Kernel Hackers Manual 4.12.13
.\"  Language: English
.\"
.TH "FC_EH_TIMED_OUT" "9" "September 2017" "Kernel Hackers Manual 4\&.12\&" "SCSI mid layer"
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.SH "NAME"
fc_eh_timed_out \- FC Transport I/O timeout intercept handler
.SH "SYNOPSIS"
.HP \w'enum\ blk_eh_timer_return\ fc_eh_timed_out('u
.BI "enum blk_eh_timer_return fc_eh_timed_out(struct\ scsi_cmnd\ *\ " "scmd" ");"
.SH "ARGUMENTS"
.PP
\fIstruct scsi_cmnd * scmd\fR
.RS 4
The SCSI command which timed out
.RE
.SH "DESCRIPTION"
.PP
This routine protects against error handlers getting invoked while a rport is in a blocked state, typically due to a temporarily loss of connectivity\&. If the error handlers are allowed to proceed, requests to abort i/o, reset the target, etc will likely fail as there is no way to communicate with the device to perform the requested function\&. These failures may result in the midlayer taking the device offline, requiring manual intervention to restore operation\&.
.PP
This routine, called whenever an i/o times out, validates the state of the underlying rport\&. If the rport is blocked, it returns EH_RESET_TIMER, which will continue to reschedule the timeout\&. Eventually, either the device will return, or devloss_tmo will fire, and when the timeout then fires, it will be handled normally\&. If the rport is not blocked, normal error handling continues\&.
.SH "NOTES"
.PP
This routine assumes no locks are held on entry\&.
.SH "AUTHORS"
.PP
\fBJames Bottomley\fR <\&James.Bottomley@hansenpartnership.com\&>
.RS 4
Author.
.RE
.PP
\fBRob Landley\fR <\&rob@landley.net\&>
.RS 4
Author.
.RE
.SH "COPYRIGHT"
.br