1 /* $OpenBSD: mpathvar.h,v 1.3 2011/07/11 01:02:48 dlg Exp $ */ 2 3 /* 4 * Copyright (c) 2010 David Gwynne <dlg@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #ifndef _SYS_SCSI_MPATH_H_ 20 #define _SYS_SCSI_MPATH_H_ 21 22 struct mpath_dev; 23 struct mpath_group; 24 25 struct mpath_ops { 26 char op_name[16]; 27 int (*op_checksense)(struct scsi_xfer *); 28 int (*op_online)(struct scsi_link *); 29 int (*op_offline)(struct scsi_link *); 30 int op_schedule; 31 }; 32 33 #define MPATH_ROUNDROBIN 0 /* use all active paths */ 34 #define MPATH_NEXT MPATH_ROUNDROBIN 35 #define MPATH_MRU 1 /* use most recently used path */ 36 37 struct mpath_path { 38 /* the path driver must set these */ 39 struct scsi_xshandler p_xsh; 40 struct scsi_link *p_link; 41 int p_gid; 42 43 /* the follwoing are private to mpath.c */ 44 TAILQ_ENTRY(mpath_path) p_entry; 45 struct mpath_dev *p_dev; 46 int p_state; 47 }; 48 49 int mpath_path_probe(struct scsi_link *); 50 int mpath_path_attach(struct mpath_path *, 51 const struct mpath_ops *); 52 void mpath_path_state(struct mpath_path *, int); 53 int mpath_path_detach(struct mpath_path *); 54 55 void mpath_start(struct mpath_path *, struct scsi_xfer *); 56 57 struct device *mpath_bootdv(struct device *); 58 59 #endif /* _SYS_SCSI_MPATH_H_ */ 60