rbd: define rbd_dev_v2_refresh()

Define a new function rbd_dev_v2_refresh() to update/refresh the
snapshot context for a format version 2 rbd image.  This function
will update anything that is not fixed for the life of an rbd
image--at the moment this is mainly the snapshot context and (for
a base mapping) the size.

Update rbd_refresh_header() so it selects which function to use
based on the image format.

Rename __rbd_refresh_header() to be rbd_dev_v1_refresh()
to be consistent with the naming of its version 2 counterpart.
Similarly rename rbd_refresh_header() to be rbd_dev_refresh().

Unrelated--we use rbd_image_format_valid() here.  Delete the other
use of it, which was primarily put in place to ensure that function
was referenced at the time it was defined.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

1 files changed, 47 insertions, 8 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index b64125d1d7bd..f11b839166ef 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -268,7 +268,8 @@ static void rbd_put_dev(struct rbd_device *rbd_dev)
         put_device(&rbd_dev->dev);
 }
 
-static int rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver);
+static int rbd_dev_refresh(struct rbd_device *rbd_dev, u64 *hver);
+static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev, u64 *hver);
 
 static int rbd_open(struct block_device *bdev, fmode_t mode)
 {
@@ -1304,7 +1305,7 @@ static void rbd_watch_cb(u64 ver, u64 notify_id, u8 opcode, void *data)
         dout("rbd_watch_cb %s notify_id=%llu opcode=%u\n",
                 rbd_dev->header_name, (unsigned long long) notify_id,
                 (unsigned int) opcode);
-        rc = rbd_refresh_header(rbd_dev, &hver);
+        rc = rbd_dev_refresh(rbd_dev, &hver);
         if (rc)
                 pr_warning(RBD_DRV_NAME "%d got notification but failed to "
                            " update snaps: %d\n", rbd_dev->major, rc);
@@ -1732,7 +1733,7 @@ static void rbd_update_mapping_size(struct rbd_device *rbd_dev)
 /*
  * only read the first part of the ondisk header, without the snaps info
  */
-static int __rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver)
+static int rbd_dev_v1_refresh(struct rbd_device *rbd_dev, u64 *hver)
 {
         int ret;
         struct rbd_image_header h;
@@ -1773,12 +1774,16 @@ static int __rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver)
         return ret;
 }
 
-static int rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver)
+static int rbd_dev_refresh(struct rbd_device *rbd_dev, u64 *hver)
 {
         int ret;
 
+        rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
         mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
-        ret = __rbd_refresh_header(rbd_dev, hver);
+        if (rbd_dev->image_format == 1)
+                ret = rbd_dev_v1_refresh(rbd_dev, hver);
+        else
+                ret = rbd_dev_v2_refresh(rbd_dev, hver);
         mutex_unlock(&ctl_mutex);
 
         return ret;
@@ -1938,7 +1943,7 @@ static ssize_t rbd_image_refresh(struct device *dev,
         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
         int ret;
 
-        ret = rbd_refresh_header(rbd_dev, NULL);
+        ret = rbd_dev_refresh(rbd_dev, NULL);
 
         return ret < 0 ? ret : size;
 }
@@ -2402,6 +2407,41 @@ static char *rbd_dev_snap_info(struct rbd_device *rbd_dev, u32 which,
         return ERR_PTR(-EINVAL);
 }
 
+static int rbd_dev_v2_refresh(struct rbd_device *rbd_dev, u64 *hver)
+{
+        int ret;
+        __u8 obj_order;
+
+        down_write(&rbd_dev->header_rwsem);
+
+        /* Grab old order first, to see if it changes */
+
+        obj_order = rbd_dev->header.obj_order,
+        ret = rbd_dev_v2_image_size(rbd_dev);
+        if (ret)
+                goto out;
+        if (rbd_dev->header.obj_order != obj_order) {
+                ret = -EIO;
+                goto out;
+        }
+        rbd_update_mapping_size(rbd_dev);
+
+        ret = rbd_dev_v2_snap_context(rbd_dev, hver);
+        dout("rbd_dev_v2_snap_context returned %d\n", ret);
+        if (ret)
+                goto out;
+        ret = rbd_dev_snaps_update(rbd_dev);
+        dout("rbd_dev_snaps_update returned %d\n", ret);
+        if (ret)
+                goto out;
+        ret = rbd_dev_snaps_register(rbd_dev);
+        dout("rbd_dev_snaps_register returned %d\n", ret);
+out:
+        up_write(&rbd_dev->header_rwsem);
+
+        return ret;
+}
+
 /*
  * Scan the rbd device's current snapshot list and compare it to the
  * newly-received snapshot context.  Remove any existing snapshots
@@ -2564,7 +2604,7 @@ static int rbd_init_watch_dev(struct rbd_device *rbd_dev)
         do {
                 ret = rbd_req_sync_watch(rbd_dev);
                 if (ret == -ERANGE) {
-                        rc = rbd_refresh_header(rbd_dev, NULL);
+                        rc = rbd_dev_refresh(rbd_dev, NULL);
                         if (rc < 0)
                                 return rc;
                 }
@@ -3045,7 +3085,6 @@ static ssize_t rbd_add(struct bus_type *bus,
         rc = rbd_dev_probe(rbd_dev);
         if (rc < 0)
                 goto err_out_client;
-        rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
 
         /* no need to lock here, as rbd_dev is not registered yet */
         rc = rbd_dev_snaps_update(rbd_dev);