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author | James Smart <James.Smart@Emulex.Com> | 2006-03-13 08:28:57 -0500 |
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committer | James Bottomley <jejb@mulgrave.il.steeleye.com> | 2006-03-13 08:58:58 -0600 |
commit | c829c394165f981d49f05a9be228404d7a9398d4 (patch) | |
tree | 649ca326052a4a35d31f150f274347ca9d38c678 /drivers/scsi/scsi_transport_fc.c | |
parent | ce313db240862d809c736c5b1dfc759817fc7ca9 (diff) | |
download | kernel_samsung_espresso10-c829c394165f981d49f05a9be228404d7a9398d4.zip kernel_samsung_espresso10-c829c394165f981d49f05a9be228404d7a9398d4.tar.gz kernel_samsung_espresso10-c829c394165f981d49f05a9be228404d7a9398d4.tar.bz2 |
[SCSI] FC transport : Avoid device offline cases by stalling aborts until device unblocked
This moves the eh_timed_out functionality from the scsi_host_template
to the transport_template. Given that this is now a transport function,
the EH_RESET_TIMER case no longer caps the timer reschedulings. The
transport guarantees that this is not an infinite condition.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'drivers/scsi/scsi_transport_fc.c')
-rw-r--r-- | drivers/scsi/scsi_transport_fc.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c index 56012b2..3c3baa9 100644 --- a/drivers/scsi/scsi_transport_fc.c +++ b/drivers/scsi/scsi_transport_fc.c @@ -31,6 +31,7 @@ #include <scsi/scsi_host.h> #include <scsi/scsi_transport.h> #include <scsi/scsi_transport_fc.h> +#include <scsi/scsi_cmnd.h> #include "scsi_priv.h" /* @@ -1090,6 +1091,40 @@ static int fc_rport_match(struct attribute_container *cont, } +/** + * fc_timed_out - FC Transport I/O timeout intercept handler + * + * @scmd: The SCSI command which timed out + * + * 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. + * + * 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. + * + * Notes: + * This routine assumes no locks are held on entry. + **/ +static enum scsi_eh_timer_return +fc_timed_out(struct scsi_cmnd *scmd) +{ + struct fc_rport *rport = starget_to_rport(scsi_target(scmd->device)); + + if (rport->port_state == FC_PORTSTATE_BLOCKED) + return EH_RESET_TIMER; + + return EH_NOT_HANDLED; +} + /* * Must be called with shost->host_lock held */ @@ -1146,6 +1181,8 @@ fc_attach_transport(struct fc_function_template *ft) /* Transport uses the shost workq for scsi scanning */ i->t.create_work_queue = 1; + i->t.eh_timed_out = fc_timed_out; + i->t.user_scan = fc_user_scan; /* |