Initial import

1 files changed, 173 insertions, 0 deletions

diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h
new file mode 100644
index 000000000..14ebb288c
--- /dev/null
+++ b/drivers/md/raid1.h
@@ -0,0 +1,173 @@
+#ifndef _RAID1_H
+#define _RAID1_H
+
+struct raid1_info {
+	struct md_rdev	*rdev;
+	sector_t	head_position;
+
+	/* When choose the best device for a read (read_balance())
+	 * we try to keep sequential reads one the same device
+	 */
+	sector_t	next_seq_sect;
+	sector_t	seq_start;
+};
+
+/*
+ * memory pools need a pointer to the mddev, so they can force an unplug
+ * when memory is tight, and a count of the number of drives that the
+ * pool was allocated for, so they know how much to allocate and free.
+ * mddev->raid_disks cannot be used, as it can change while a pool is active
+ * These two datums are stored in a kmalloced struct.
+ * The 'raid_disks' here is twice the raid_disks in r1conf.
+ * This allows space for each 'real' device can have a replacement in the
+ * second half of the array.
+ */
+
+struct pool_info {
+	struct mddev *mddev;
+	int	raid_disks;
+};
+
+struct r1conf {
+	struct mddev		*mddev;
+	struct raid1_info	*mirrors;	/* twice 'raid_disks' to
+						 * allow for replacements.
+						 */
+	int			raid_disks;
+
+	/* During resync, read_balancing is only allowed on the part
+	 * of the array that has been resynced.  'next_resync' tells us
+	 * where that is.
+	 */
+	sector_t		next_resync;
+
+	/* When raid1 starts resync, we divide array into four partitions
+	 * |---------|--------------|---------------------|-------------|
+	 *        next_resync   start_next_window       end_window
+	 * start_next_window = next_resync + NEXT_NORMALIO_DISTANCE
+	 * end_window = start_next_window + NEXT_NORMALIO_DISTANCE
+	 * current_window_requests means the count of normalIO between
+	 *   start_next_window and end_window.
+	 * next_window_requests means the count of normalIO after end_window.
+	 * */
+	sector_t		start_next_window;
+	int			current_window_requests;
+	int			next_window_requests;
+
+	spinlock_t		device_lock;
+
+	/* list of 'struct r1bio' that need to be processed by raid1d,
+	 * whether to retry a read, writeout a resync or recovery
+	 * block, or anything else.
+	 */
+	struct list_head	retry_list;
+
+	/* queue pending writes to be submitted on unplug */
+	struct bio_list		pending_bio_list;
+	int			pending_count;
+
+	/* for use when syncing mirrors:
+	 * We don't allow both normal IO and resync/recovery IO at
+	 * the same time - resync/recovery can only happen when there
+	 * is no other IO.  So when either is active, the other has to wait.
+	 * See more details description in raid1.c near raise_barrier().
+	 */
+	wait_queue_head_t	wait_barrier;
+	spinlock_t		resync_lock;
+	int			nr_pending;
+	int			nr_waiting;
+	int			nr_queued;
+	int			barrier;
+	int			array_frozen;
+
+	/* Set to 1 if a full sync is needed, (fresh device added).
+	 * Cleared when a sync completes.
+	 */
+	int			fullsync;
+
+	/* When the same as mddev->recovery_disabled we don't allow
+	 * recovery to be attempted as we expect a read error.
+	 */
+	int			recovery_disabled;
+
+	/* poolinfo contains information about the content of the
+	 * mempools - it changes when the array grows or shrinks
+	 */
+	struct pool_info	*poolinfo;
+	mempool_t		*r1bio_pool;
+	mempool_t		*r1buf_pool;
+
+	/* temporary buffer to synchronous IO when attempting to repair
+	 * a read error.
+	 */
+	struct page		*tmppage;
+
+	/* When taking over an array from a different personality, we store
+	 * the new thread here until we fully activate the array.
+	 */
+	struct md_thread	*thread;
+};
+
+/*
+ * this is our 'private' RAID1 bio.
+ *
+ * it contains information about what kind of IO operations were started
+ * for this RAID1 operation, and about their status:
+ */
+
+struct r1bio {
+	atomic_t		remaining; /* 'have we finished' count,
+					    * used from IRQ handlers
+					    */
+	atomic_t		behind_remaining; /* number of write-behind ios remaining
+						 * in this BehindIO request
+						 */
+	sector_t		sector;
+	sector_t		start_next_window;
+	int			sectors;
+	unsigned long		state;
+	struct mddev		*mddev;
+	/*
+	 * original bio going to /dev/mdx
+	 */
+	struct bio		*master_bio;
+	/*
+	 * if the IO is in READ direction, then this is where we read
+	 */
+	int			read_disk;
+
+	struct list_head	retry_list;
+	/* Next two are only valid when R1BIO_BehindIO is set */
+	struct bio_vec		*behind_bvecs;
+	int			behind_page_count;
+	/*
+	 * if the IO is in WRITE direction, then multiple bios are used.
+	 * We choose the number when they are allocated.
+	 */
+	struct bio		*bios[0];
+	/* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
+};
+
+/* bits for r1bio.state */
+#define	R1BIO_Uptodate	0
+#define	R1BIO_IsSync	1
+#define	R1BIO_Degraded	2
+#define	R1BIO_BehindIO	3
+/* Set ReadError on bios that experience a readerror so that
+ * raid1d knows what to do with them.
+ */
+#define R1BIO_ReadError 4
+/* For write-behind requests, we call bi_end_io when
+ * the last non-write-behind device completes, providing
+ * any write was successful.  Otherwise we call when
+ * any write-behind write succeeds, otherwise we call
+ * with failure when last write completes (and all failed).
+ * Record that bi_end_io was called with this flag...
+ */
+#define	R1BIO_Returned 6
+/* If a write for this request means we can clear some
+ * known-bad-block records, we set this flag
+ */
+#define	R1BIO_MadeGood 7
+#define	R1BIO_WriteError 8
+#endif