Update copyright and license information.

[fs/lustre-release.git] / lustre / include / linux / obd_snap_support.h

diff --git a/lustre/include/linux/obd_snap_support.h b/lustre/include/linux/obd_snap_support.h
index 3fc8b42..e7dd012 100644 (file)
--- a/lustre/include/linux/obd_snap_support.h
+++ b/lustre/include/linux/obd_snap_support.h
@@ -1,5 +1,63 @@
 #ifndef __OBD_SNAP_SUPP_H
 #define __OBD_SNAP_SUPP_H
+/*
+ * Copyright (C) 2001  Cluster File Systems, Inc.
+ *
+ * This code is issued under the GNU General Public License.
+ * See the file COPYING in this distribution
+ */
+
+/* What we use to point to IDs in the obdmd data for snapshots.  If we use
+ * obd_id (8 bytes) instead of ino_t (4 bytes), we halve the number of
+ * available snapshot slots (14 in 56 bytes vs. 7 in 56 bytes until we
+ * increase the size of OBD_OBDMDSZ).
+ */
+typedef ino_t  snap_id;
+
+/* maximum number of snapshot tables we maintain in the kernel */
+#define SNAP_MAX_TABLES 8
+
+/* maximum number of snapshots per device 
+   must fit in "o_obdmd" area of struct obdo */
+#define SNAP_MAX ((OBD_OBDMDSZ - sizeof(uint32_t))/sizeof(snap_id))
+
+struct snap_md {
+       uint32_t m_magic;
+       snap_id  m_ids[SNAP_MAX];       /* id of snaps; slot 0 has current id */
+};
+
+
+/* if time is 0 this designates the "current" snapshot, i.e.
+   the head of the tree 
+*/
+struct snap {
+       time_t time;
+       int index;
+};
+
+/* snap ioctl data for attach: current always in first slot of this array */
+struct snap_obd_data {
+       int          snap_dev;  /* which device contains the data */
+       unsigned int snap_index;/* which snapshot is ours */
+       unsigned int snap_table;/* which table do we use */
+};
+
+
+/* snap ioctl data for table fiddling */
+struct snap_table_data {
+       int             tblcmd_no;      /* which table */
+       unsigned int    tblcmd_count;   /* how many snaps */
+       struct snap     tblcmd_snaps[SNAP_MAX]; /* sorted times! */
+};
+
+
+struct snap_table {
+       spinlock_t          tbl_lock;
+       unsigned int tbl_count; /* how many snapshots exist in this table*/
+       int tbl_used;  /* bitmap of snaps in use by a device */
+       time_t tbl_times[SNAP_MAX];
+       int tbl_index[SNAP_MAX];
+};
 
 struct snap_iterdata {
        struct obd_conn *conn;
@@ -11,10 +69,17 @@ struct snap_iterdata {
        time_t prevtime;
 };
 
-
 inline struct obd_conn *child_conn(struct obd_conn *conn);
-int snap_deleteino(objid id, void *data);
-int snap_restoreino(objid id, void *data);
+int snap_deleteobj(obd_id id, obd_gr group, void *data);
+int snap_restoreobj(obd_id id, obd_gr group, void *data);
+int snap_printobj(obd_id id, obd_gr group, void *data);
 int snap_iocontrol(int cmd, struct obd_conn *conn, int len, void *karg, void *uarg);
 
+/* In the future, this function may have to deal with offsets into the obdmd.
+ * Currently, we assume we have the whole obdmd struct.
+ */
+static __inline__ struct snap_md *snap_obdmd(struct obdo *oa)
+{
+       return ((struct snap_md *)(&oa->o_obdmd));
+}
 #endif