242f9dcb8b
Right now SCSI and others do their own command timeout handling. Move those bits to the block layer. Instead of having a timer per command, we try to be a bit more clever and simply have one per-queue. This avoids the overhead of having to tear down and setup a timer for each command, so it will result in a lot less timer fiddling. Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
121 lines
3.9 KiB
C
121 lines
3.9 KiB
C
/*
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* Transport specific attributes.
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*
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* Copyright (c) 2003 Silicon Graphics, Inc. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#ifndef SCSI_TRANSPORT_H
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#define SCSI_TRANSPORT_H
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#include <linux/transport_class.h>
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#include <linux/blkdev.h>
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#include <scsi/scsi_host.h>
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#include <scsi/scsi_device.h>
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struct scsi_transport_template {
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/* the attribute containers */
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struct transport_container host_attrs;
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struct transport_container target_attrs;
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struct transport_container device_attrs;
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/*
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* If set, called from sysfs and legacy procfs rescanning code.
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*/
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int (*user_scan)(struct Scsi_Host *, uint, uint, uint);
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/* The size of the specific transport attribute structure (a
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* space of this size will be left at the end of the
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* scsi_* structure */
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int device_size;
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int device_private_offset;
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int target_size;
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int target_private_offset;
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int host_size;
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/* no private offset for the host; there's an alternative mechanism */
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/*
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* True if the transport wants to use a host-based work-queue
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*/
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unsigned int create_work_queue : 1;
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/*
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* Allows a transport to override the default error handler.
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*/
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void (* eh_strategy_handler)(struct Scsi_Host *);
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/*
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* This is an optional routine that allows the transport to become
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* involved when a scsi io timer fires. The return value tells the
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* timer routine how to finish the io timeout handling:
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* EH_HANDLED: I fixed the error, please complete the command
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* EH_RESET_TIMER: I need more time, reset the timer and
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* begin counting again
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* EH_NOT_HANDLED Begin normal error recovery
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*/
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enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
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/*
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* Used as callback for the completion of i_t_nexus request
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* for target drivers.
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*/
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int (* it_nexus_response)(struct Scsi_Host *, u64, int);
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/*
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* Used as callback for the completion of task management
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* request for target drivers.
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*/
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int (* tsk_mgmt_response)(struct Scsi_Host *, u64, u64, int);
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};
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#define transport_class_to_shost(tc) \
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dev_to_shost((tc)->parent)
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/* Private area maintenance. The driver requested allocations come
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* directly after the transport class allocations (if any). The idea
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* is that you *must* call these only once. The code assumes that the
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* initial values are the ones the transport specific code requires */
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static inline void
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scsi_transport_reserve_target(struct scsi_transport_template * t, int space)
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{
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BUG_ON(t->target_private_offset != 0);
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t->target_private_offset = ALIGN(t->target_size, sizeof(void *));
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t->target_size = t->target_private_offset + space;
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}
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static inline void
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scsi_transport_reserve_device(struct scsi_transport_template * t, int space)
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{
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BUG_ON(t->device_private_offset != 0);
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t->device_private_offset = ALIGN(t->device_size, sizeof(void *));
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t->device_size = t->device_private_offset + space;
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}
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static inline void *
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scsi_transport_target_data(struct scsi_target *starget)
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{
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struct Scsi_Host *shost = dev_to_shost(&starget->dev);
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return (u8 *)starget->starget_data
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+ shost->transportt->target_private_offset;
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}
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static inline void *
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scsi_transport_device_data(struct scsi_device *sdev)
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{
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struct Scsi_Host *shost = sdev->host;
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return (u8 *)sdev->sdev_data
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+ shost->transportt->device_private_offset;
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}
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#endif /* SCSI_TRANSPORT_H */
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