patch-2.4.10 linux/include/linux/raid/multipath.h

• Lines: 88
• Date: Fri Sep 14 14:22:18 2001
• Orig file: v2.4.9/linux/include/linux/raid/multipath.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.9/linux/include/linux/raid/multipath.h linux/include/linux/raid/multipath.h
@@ -0,0 +1,87 @@
+#ifndef _MULTIPATH_H
+#define _MULTIPATH_H
+
+#include <linux/raid/md.h>
+
+struct multipath_info {
+	int		number;
+	int		raid_disk;
+	kdev_t		dev;
+	int		sect_limit;
+	int		head_position;
+
+	/*
+	 * State bits:
+	 */
+	int		operational;
+	int		write_only;
+	int		spare;
+
+	int		used_slot;
+};
+
+struct multipath_private_data {
+	mddev_t			*mddev;
+	struct multipath_info	multipaths[MD_SB_DISKS];
+	int			nr_disks;
+	int			raid_disks;
+	int			working_disks;
+	mdk_thread_t		*thread;
+	struct multipath_info	*spare;
+	md_spinlock_t		device_lock;
+
+	/* buffer pool */
+	/* buffer_heads that we have pre-allocated have b_pprev -> &freebh
+	 * and are linked into a stack using b_next
+	 * multipath_bh that are pre-allocated have MPBH_PreAlloc set.
+	 * All these variable are protected by device_lock
+	 */
+	struct buffer_head	*freebh;
+	int			freebh_cnt;	/* how many are on the list */
+	struct multipath_bh	*freer1;
+	struct multipath_bh	*freebuf; 	/* each bh_req has a page allocated */
+	md_wait_queue_head_t	wait_buffer;
+
+	/* for use when syncing multipaths: */
+	unsigned long	start_active, start_ready,
+		start_pending, start_future;
+	int	cnt_done, cnt_active, cnt_ready,
+		cnt_pending, cnt_future;
+	int	phase;
+	int	window;
+	md_wait_queue_head_t	wait_done;
+	md_wait_queue_head_t	wait_ready;
+	md_spinlock_t		segment_lock;
+};
+
+typedef struct multipath_private_data multipath_conf_t;
+
+/*
+ * this is the only point in the RAID code where we violate
+ * C type safety. mddev->private is an 'opaque' pointer.
+ */
+#define mddev_to_conf(mddev) ((multipath_conf_t *) mddev->private)
+
+/*
+ * this is our 'private' 'collective' MULTIPATH buffer head.
+ * it contains information about what kind of IO operations were started
+ * for this MULTIPATH operation, and about their status:
+ */
+
+struct multipath_bh {
+	atomic_t		remaining; /* 'have we finished' count,
+					    * used from IRQ handlers
+					    */
+	int			cmd;
+	unsigned long		state;
+	mddev_t			*mddev;
+	struct buffer_head	*master_bh;
+	struct buffer_head	*multipath_bh_list;
+	struct buffer_head	bh_req;
+	struct multipath_bh	*next_r1;	/* next for retry or in free list */
+};
+/* bits for multipath_bh.state */
+#define	MPBH_Uptodate	1
+#define	MPBH_SyncPhase	2
+#define	MPBH_PreAlloc	3	/* this was pre-allocated, add to free list */
+#endif