DRBD: internal_data_structures

The big "struct drbd_conf". It actually describes one DRBD device.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

drivers/block/drbd/drbd_wrappers.h

+#include <linux/ctype.h>
+#include <linux/mm.h>
+
+
+/* see get_sb_bdev and bd_claim */
+extern char *drbd_sec_holder;
+
+static inline sector_t drbd_get_hardsect(struct block_device *bdev)
+{
+	return bdev->bd_disk->queue->hardsect_size;
+}
+
+/* sets the number of 512 byte sectors of our virtual device */
+static inline void drbd_set_my_capacity(struct drbd_conf *mdev,
+					sector_t size)
+{
+	/* set_capacity(mdev->this_bdev->bd_disk, size); */
+	set_capacity(mdev->vdisk, size);
+	mdev->this_bdev->bd_inode->i_size = (loff_t)size << 9;
+}
+
+#define drbd_bio_uptodate(bio) bio_flagged(bio, BIO_UPTODATE)
+
+static inline int drbd_bio_has_active_page(struct bio *bio)
+{
+	struct bio_vec *bvec;
+	int i;
+
+	__bio_for_each_segment(bvec, bio, i, 0) {
+		if (page_count(bvec->bv_page) > 1)
+			return 1;
+	}
+
+	return 0;
+}
+
+/* bi_end_io handlers */
+extern void drbd_md_io_complete(struct bio *bio, int error);
+extern void drbd_endio_read_sec(struct bio *bio, int error);
+extern void drbd_endio_write_sec(struct bio *bio, int error);
+extern void drbd_endio_pri(struct bio *bio, int error);
+
+/* how to get to the kobj of a gendisk.
+ * see also upstream commits
+ * edfaa7c36574f1bf09c65ad602412db9da5f96bf
+ * ed9e1982347b36573cd622ee5f4e2a7ccd79b3fd
+ * 548b10eb2959c96cef6fc29fc96e0931eeb53bc5
+ */
+#ifndef dev_to_disk
+# define disk_to_kobj(disk) (&(disk)->kobj)
+#else
+# ifndef disk_to_dev
+#  define disk_to_dev(disk) (&(disk)->dev)
+# endif
+# define disk_to_kobj(disk) (&disk_to_dev(disk)->kobj)
+#endif
+static inline void drbd_kobject_uevent(struct drbd_conf *mdev)
+{
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,10)
+#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,15)
+	kobject_uevent(disk_to_kobj(mdev->vdisk), KOBJ_CHANGE, NULL);
+#else
+	kobject_uevent(disk_to_kobj(mdev->vdisk), KOBJ_CHANGE);
+	/* rhel4 / sles9 and older don't have this at all,
+	 * which means user space (udev) won't get events about possible changes of
+	 * corresponding resource + disk names after the initial drbd minor creation.
+	 */
+#endif
+#endif
+}
+
+
+/*
+ * used to submit our private bio
+ */
+static inline void drbd_generic_make_request(struct drbd_conf *mdev,
+					     int fault_type, struct bio *bio)
+{
+	__release(local);
+	if (!bio->bi_bdev) {
+		printk(KERN_ERR "drbd%d: drbd_generic_make_request: "
+				"bio->bi_bdev == NULL\n",
+		       mdev_to_minor(mdev));
+		dump_stack();
+		bio_endio(bio, -ENODEV);
+		return;
+	}
+
+	if (FAULT_ACTIVE(mdev, fault_type))
+		bio_endio(bio, -EIO);
+	else
+		generic_make_request(bio);
+}
+
+static inline void drbd_plug_device(struct drbd_conf *mdev)
+{
+	struct request_queue *q;
+	q = bdev_get_queue(mdev->this_bdev);
+
+	spin_lock_irq(q->queue_lock);
+
+/* XXX the check on !blk_queue_plugged is redundant,
+ * implicitly checked in blk_plug_device */
+
+	if (!blk_queue_plugged(q)) {
+		blk_plug_device(q);
+		del_timer(&q->unplug_timer);
+		/* unplugging should not happen automatically... */
+	}
+	spin_unlock_irq(q->queue_lock);
+}
+
+#ifndef __CHECKER__
+# undef __cond_lock
+# define __cond_lock(x,c) (c)
+#endif
+