5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ilya Dryomov <idryomov@xxxxxxxxx>
commit c10311776f0a8ddea2276df96e255625b07045a8 upstream.
Unlike header read-in, parent info read-in is already decoupled in
get_parent_info(), but it's buried in rbd_dev_v2_parent_info() along
with the processing logic.
Separate the initial read-in and update read-in logic into
rbd_dev_setup_parent() and rbd_dev_update_parent() respectively and
have rbd_dev_v2_parent_info() just populate struct parent_image_info
(i.e. what get_parent_info() did). Some existing QoI issues, like
flatten of a standalone clone being disregarded on refresh, remain.
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Reviewed-by: Dongsheng Yang <dongsheng.yang@xxxxxxxxxxxx>
[idryomov@xxxxxxxxx: backport to 5.4: context]
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/block/rbd.c | 142 +++++++++++++++++++++++++-------------------
1 file changed, 80 insertions(+), 62 deletions(-)
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 17d802effdc41..e86dca49fae71 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -5762,6 +5762,14 @@ struct parent_image_info {
u64 overlap;
};
+static void rbd_parent_info_cleanup(struct parent_image_info *pii)
+{
+ kfree(pii->pool_ns);
+ kfree(pii->image_id);
+
+ memset(pii, 0, sizeof(*pii));
+}
+
/*
* The caller is responsible for @pii.
*/
@@ -5831,6 +5839,9 @@ static int __get_parent_info(struct rbd_device *rbd_dev,
if (pii->has_overlap)
ceph_decode_64_safe(&p, end, pii->overlap, e_inval);
+ dout("%s pool_id %llu pool_ns %s image_id %s snap_id %llu has_overlap %d overlap %llu\n",
+ __func__, pii->pool_id, pii->pool_ns, pii->image_id, pii->snap_id,
+ pii->has_overlap, pii->overlap);
return 0;
e_inval:
@@ -5869,14 +5880,17 @@ static int __get_parent_info_legacy(struct rbd_device *rbd_dev,
pii->has_overlap = true;
ceph_decode_64_safe(&p, end, pii->overlap, e_inval);
+ dout("%s pool_id %llu pool_ns %s image_id %s snap_id %llu has_overlap %d overlap %llu\n",
+ __func__, pii->pool_id, pii->pool_ns, pii->image_id, pii->snap_id,
+ pii->has_overlap, pii->overlap);
return 0;
e_inval:
return -EINVAL;
}
-static int get_parent_info(struct rbd_device *rbd_dev,
- struct parent_image_info *pii)
+static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev,
+ struct parent_image_info *pii)
{
struct page *req_page, *reply_page;
void *p;
@@ -5904,7 +5918,7 @@ static int get_parent_info(struct rbd_device *rbd_dev,
return ret;
}
-static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
+static int rbd_dev_setup_parent(struct rbd_device *rbd_dev)
{
struct rbd_spec *parent_spec;
struct parent_image_info pii = { 0 };
@@ -5914,37 +5928,12 @@ static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
if (!parent_spec)
return -ENOMEM;
- ret = get_parent_info(rbd_dev, &pii);
+ ret = rbd_dev_v2_parent_info(rbd_dev, &pii);
if (ret)
goto out_err;
- dout("%s pool_id %llu pool_ns %s image_id %s snap_id %llu has_overlap %d overlap %llu\n",
- __func__, pii.pool_id, pii.pool_ns, pii.image_id, pii.snap_id,
- pii.has_overlap, pii.overlap);
-
- if (pii.pool_id == CEPH_NOPOOL || !pii.has_overlap) {
- /*
- * Either the parent never existed, or we have
- * record of it but the image got flattened so it no
- * longer has a parent. When the parent of a
- * layered image disappears we immediately set the
- * overlap to 0. The effect of this is that all new
- * requests will be treated as if the image had no
- * parent.
- *
- * If !pii.has_overlap, the parent image spec is not
- * applicable. It's there to avoid duplication in each
- * snapshot record.
- */
- if (rbd_dev->parent_overlap) {
- rbd_dev->parent_overlap = 0;
- rbd_dev_parent_put(rbd_dev);
- pr_info("%s: clone image has been flattened\n",
- rbd_dev->disk->disk_name);
- }
-
+ if (pii.pool_id == CEPH_NOPOOL || !pii.has_overlap)
goto out; /* No parent? No problem. */
- }
/* The ceph file layout needs to fit pool id in 32 bits */
@@ -5956,46 +5945,34 @@ static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
}
/*
- * The parent won't change (except when the clone is
- * flattened, already handled that). So we only need to
- * record the parent spec we have not already done so.
+ * The parent won't change except when the clone is flattened,
+ * so we only need to record the parent image spec once.
*/
- if (!rbd_dev->parent_spec) {
- parent_spec->pool_id = pii.pool_id;
- if (pii.pool_ns && *pii.pool_ns) {
- parent_spec->pool_ns = pii.pool_ns;
- pii.pool_ns = NULL;
- }
- parent_spec->image_id = pii.image_id;
- pii.image_id = NULL;
- parent_spec->snap_id = pii.snap_id;
-
- rbd_dev->parent_spec = parent_spec;
- parent_spec = NULL; /* rbd_dev now owns this */
+ parent_spec->pool_id = pii.pool_id;
+ if (pii.pool_ns && *pii.pool_ns) {
+ parent_spec->pool_ns = pii.pool_ns;
+ pii.pool_ns = NULL;
}
+ parent_spec->image_id = pii.image_id;
+ pii.image_id = NULL;
+ parent_spec->snap_id = pii.snap_id;
+
+ rbd_assert(!rbd_dev->parent_spec);
+ rbd_dev->parent_spec = parent_spec;
+ parent_spec = NULL; /* rbd_dev now owns this */
/*
- * We always update the parent overlap. If it's zero we issue
- * a warning, as we will proceed as if there was no parent.
+ * Record the parent overlap. If it's zero, issue a warning as
+ * we will proceed as if there is no parent.
*/
- if (!pii.overlap) {
- if (parent_spec) {
- /* refresh, careful to warn just once */
- if (rbd_dev->parent_overlap)
- rbd_warn(rbd_dev,
- "clone now standalone (overlap became 0)");
- } else {
- /* initial probe */
- rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
- }
- }
+ if (!pii.overlap)
+ rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
rbd_dev->parent_overlap = pii.overlap;
out:
ret = 0;
out_err:
- kfree(pii.pool_ns);
- kfree(pii.image_id);
+ rbd_parent_info_cleanup(&pii);
rbd_spec_put(parent_spec);
return ret;
}
@@ -6992,7 +6969,7 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
}
if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
- ret = rbd_dev_v2_parent_info(rbd_dev);
+ ret = rbd_dev_setup_parent(rbd_dev);
if (ret)
goto err_out_probe;
}
@@ -7041,9 +7018,47 @@ static void rbd_dev_update_header(struct rbd_device *rbd_dev,
}
}
+static void rbd_dev_update_parent(struct rbd_device *rbd_dev,
+ struct parent_image_info *pii)
+{
+ if (pii->pool_id == CEPH_NOPOOL || !pii->has_overlap) {
+ /*
+ * Either the parent never existed, or we have
+ * record of it but the image got flattened so it no
+ * longer has a parent. When the parent of a
+ * layered image disappears we immediately set the
+ * overlap to 0. The effect of this is that all new
+ * requests will be treated as if the image had no
+ * parent.
+ *
+ * If !pii.has_overlap, the parent image spec is not
+ * applicable. It's there to avoid duplication in each
+ * snapshot record.
+ */
+ if (rbd_dev->parent_overlap) {
+ rbd_dev->parent_overlap = 0;
+ rbd_dev_parent_put(rbd_dev);
+ pr_info("%s: clone has been flattened\n",
+ rbd_dev->disk->disk_name);
+ }
+ } else {
+ rbd_assert(rbd_dev->parent_spec);
+
+ /*
+ * Update the parent overlap. If it became zero, issue
+ * a warning as we will proceed as if there is no parent.
+ */
+ if (!pii->overlap && rbd_dev->parent_overlap)
+ rbd_warn(rbd_dev,
+ "clone has become standalone (overlap 0)");
+ rbd_dev->parent_overlap = pii->overlap;
+ }
+}
+
static int rbd_dev_refresh(struct rbd_device *rbd_dev)
{
struct rbd_image_header header = { 0 };
+ struct parent_image_info pii = { 0 };
u64 mapping_size;
int ret;
@@ -7059,12 +7074,14 @@ static int rbd_dev_refresh(struct rbd_device *rbd_dev)
* mapped image getting flattened.
*/
if (rbd_dev->parent) {
- ret = rbd_dev_v2_parent_info(rbd_dev);
+ ret = rbd_dev_v2_parent_info(rbd_dev, &pii);
if (ret)
goto out;
}
rbd_dev_update_header(rbd_dev, &header);
+ if (rbd_dev->parent)
+ rbd_dev_update_parent(rbd_dev, &pii);
if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
rbd_dev->mapping.size = rbd_dev->header.image_size;
@@ -7078,6 +7095,7 @@ static int rbd_dev_refresh(struct rbd_device *rbd_dev)
if (!ret && mapping_size != rbd_dev->mapping.size)
rbd_dev_update_size(rbd_dev);
+ rbd_parent_info_cleanup(&pii);
rbd_image_header_cleanup(&header);
return ret;
}
--
2.40.1
