From b8b1e2db52de61f575981d0c23da785a7c5b4a77 Mon Sep 17 00:00:00 2001
From: Alex Elder <elder@inktank.com>
Date: Tue, 3 Jul 2012 16:01:19 -0500
Subject: [PATCH] rbd: get snapshot name for a v2 image
Define rbd_dev_v2_snap_name() to fetch the name for a particular
snapshot in a format 2 rbd image.
Define rbd_dev_v2_snap_info() to to be a wrapper for getting the
name, size, and features for a particular snapshot, using an
interface that matches the equivalent function for version 1 images.
Define rbd_dev_snap_info() wrapper function and use it to call the
appropriate function for getting the snapshot name, size, and
features, dependent on the rbd image format.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
---
drivers/block/rbd.c | 81 +++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 79 insertions(+), 2 deletions(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index b673a8dc161d0..b51f1c997c1d0 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2319,6 +2319,83 @@ out:
return 0;
}
+static char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev, u32 which)
+{
+ size_t size;
+ void *reply_buf;
+ __le64 snap_id;
+ int ret;
+ void *p;
+ void *end;
+ size_t snap_name_len;
+ char *snap_name;
+
+ size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
+ reply_buf = kmalloc(size, GFP_KERNEL);
+ if (!reply_buf)
+ return ERR_PTR(-ENOMEM);
+
+ snap_id = cpu_to_le64(rbd_dev->header.snapc->snaps[which]);
+ ret = rbd_req_sync_exec(rbd_dev, rbd_dev->header_name,
+ "rbd", "get_snapshot_name",
+ (char *) &snap_id, sizeof (snap_id),
+ reply_buf, size,
+ CEPH_OSD_FLAG_READ, NULL);
+ dout("%s: rbd_req_sync_exec returned %d\n", __func__, ret);
+ if (ret < 0)
+ goto out;
+
+ p = reply_buf;
+ end = (char *) reply_buf + size;
+ snap_name_len = 0;
+ snap_name = ceph_extract_encoded_string(&p, end, &snap_name_len,
+ GFP_KERNEL);
+ if (IS_ERR(snap_name)) {
+ ret = PTR_ERR(snap_name);
+ goto out;
+ } else {
+ dout(" snap_id 0x%016llx snap_name = %s\n",
+ (unsigned long long) le64_to_cpu(snap_id), snap_name);
+ }
+ kfree(reply_buf);
+
+ return snap_name;
+out:
+ kfree(reply_buf);
+
+ return ERR_PTR(ret);
+}
+
+static char *rbd_dev_v2_snap_info(struct rbd_device *rbd_dev, u32 which,
+ u64 *snap_size, u64 *snap_features)
+{
+ __le64 snap_id;
+ u8 order;
+ int ret;
+
+ snap_id = rbd_dev->header.snapc->snaps[which];
+ ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, &order, snap_size);
+ if (ret)
+ return ERR_PTR(ret);
+ ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, snap_features);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return rbd_dev_v2_snap_name(rbd_dev, which);
+}
+
+static char *rbd_dev_snap_info(struct rbd_device *rbd_dev, u32 which,
+ u64 *snap_size, u64 *snap_features)
+{
+ if (rbd_dev->image_format == 1)
+ return rbd_dev_v1_snap_info(rbd_dev, which,
+ snap_size, snap_features);
+ if (rbd_dev->image_format == 2)
+ return rbd_dev_v2_snap_info(rbd_dev, which,
+ snap_size, snap_features);
+ return ERR_PTR(-EINVAL);
+}
+
/*
* Scan the rbd device's current snapshot list and compare it to the
* newly-received snapshot context. Remove any existing snapshots
@@ -2372,8 +2449,8 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev)
continue;
}
- snap_name = rbd_dev_v1_snap_info(rbd_dev, index,
- &snap_size, &snap_features);
+ snap_name = rbd_dev_snap_info(rbd_dev, index,
+ &snap_size, &snap_features);
if (IS_ERR(snap_name))
return PTR_ERR(snap_name);
--
2.30.2