Commit 043b3e22 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by David S. Miller

devlink: let kernel allocate region snapshot id

Currently users have to choose a free snapshot id before
calling DEVLINK_CMD_REGION_NEW. This is potentially racy
and inconvenient.

Make the DEVLINK_ATTR_REGION_SNAPSHOT_ID optional and try
to allocate id automatically. Send a message back to the
caller with the snapshot info.

Example use:
$ devlink region new netdevsim/netdevsim1/dummy
netdevsim/netdevsim1/dummy: snapshot 1

$ id=$(devlink -j region new netdevsim/netdevsim1/dummy | \
       jq '.[][][][]')
$ devlink region dump netdevsim/netdevsim1/dummy snapshot $id
[...]
$ devlink region del netdevsim/netdevsim1/dummy snapshot $id

v4:
 - inline the notification code
v3:
 - send the notification only once snapshot creation completed.
v2:
 - don't wrap the line containing extack;
 - add a few sentences to the docs.
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Reviewed-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent dd86fec7
...@@ -23,7 +23,9 @@ states, but see also :doc:`devlink-health` ...@@ -23,7 +23,9 @@ states, but see also :doc:`devlink-health`
Regions may optionally support capturing a snapshot on demand via the Regions may optionally support capturing a snapshot on demand via the
``DEVLINK_CMD_REGION_NEW`` netlink message. A driver wishing to allow ``DEVLINK_CMD_REGION_NEW`` netlink message. A driver wishing to allow
requested snapshots must implement the ``.snapshot`` callback for the region requested snapshots must implement the ``.snapshot`` callback for the region
in its ``devlink_region_ops`` structure. in its ``devlink_region_ops`` structure. If snapshot id is not set in
the ``DEVLINK_CMD_REGION_NEW`` request kernel will allocate one and send
the snapshot information to user space.
example usage example usage
------------- -------------
...@@ -45,7 +47,8 @@ example usage ...@@ -45,7 +47,8 @@ example usage
$ devlink region del pci/0000:00:05.0/cr-space snapshot 1 $ devlink region del pci/0000:00:05.0/cr-space snapshot 1
# Request an immediate snapshot, if supported by the region # Request an immediate snapshot, if supported by the region
$ devlink region new pci/0000:00:05.0/cr-space snapshot 5 $ devlink region new pci/0000:00:05.0/cr-space
pci/0000:00:05.0/cr-space: snapshot 5
# Dump a snapshot: # Dump a snapshot:
$ devlink region dump pci/0000:00:05.0/fw-health snapshot 1 $ devlink region dump pci/0000:00:05.0/fw-health snapshot 1
......
...@@ -4086,6 +4086,8 @@ static int ...@@ -4086,6 +4086,8 @@ static int
devlink_nl_cmd_region_new(struct sk_buff *skb, struct genl_info *info) devlink_nl_cmd_region_new(struct sk_buff *skb, struct genl_info *info)
{ {
struct devlink *devlink = info->user_ptr[0]; struct devlink *devlink = info->user_ptr[0];
struct devlink_snapshot *snapshot;
struct nlattr *snapshot_id_attr;
struct devlink_region *region; struct devlink_region *region;
const char *region_name; const char *region_name;
u32 snapshot_id; u32 snapshot_id;
...@@ -4097,11 +4099,6 @@ devlink_nl_cmd_region_new(struct sk_buff *skb, struct genl_info *info) ...@@ -4097,11 +4099,6 @@ devlink_nl_cmd_region_new(struct sk_buff *skb, struct genl_info *info)
return -EINVAL; return -EINVAL;
} }
if (!info->attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID]) {
NL_SET_ERR_MSG_MOD(info->extack, "No snapshot id provided");
return -EINVAL;
}
region_name = nla_data(info->attrs[DEVLINK_ATTR_REGION_NAME]); region_name = nla_data(info->attrs[DEVLINK_ATTR_REGION_NAME]);
region = devlink_region_get_by_name(devlink, region_name); region = devlink_region_get_by_name(devlink, region_name);
if (!region) { if (!region) {
...@@ -4119,7 +4116,9 @@ devlink_nl_cmd_region_new(struct sk_buff *skb, struct genl_info *info) ...@@ -4119,7 +4116,9 @@ devlink_nl_cmd_region_new(struct sk_buff *skb, struct genl_info *info)
return -ENOSPC; return -ENOSPC;
} }
snapshot_id = nla_get_u32(info->attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID]); snapshot_id_attr = info->attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID];
if (snapshot_id_attr) {
snapshot_id = nla_get_u32(snapshot_id_attr);
if (devlink_region_snapshot_get_by_id(region, snapshot_id)) { if (devlink_region_snapshot_get_by_id(region, snapshot_id)) {
NL_SET_ERR_MSG_MOD(info->extack, "The requested snapshot id is already in use"); NL_SET_ERR_MSG_MOD(info->extack, "The requested snapshot id is already in use");
...@@ -4129,6 +4128,13 @@ devlink_nl_cmd_region_new(struct sk_buff *skb, struct genl_info *info) ...@@ -4129,6 +4128,13 @@ devlink_nl_cmd_region_new(struct sk_buff *skb, struct genl_info *info)
err = __devlink_snapshot_id_insert(devlink, snapshot_id); err = __devlink_snapshot_id_insert(devlink, snapshot_id);
if (err) if (err)
return err; return err;
} else {
err = __devlink_region_snapshot_id_get(devlink, &snapshot_id);
if (err) {
NL_SET_ERR_MSG_MOD(info->extack, "Failed to allocate a new snapshot id");
return err;
}
}
err = region->ops->snapshot(devlink, info->extack, &data); err = region->ops->snapshot(devlink, info->extack, &data);
if (err) if (err)
...@@ -4138,6 +4144,27 @@ devlink_nl_cmd_region_new(struct sk_buff *skb, struct genl_info *info) ...@@ -4138,6 +4144,27 @@ devlink_nl_cmd_region_new(struct sk_buff *skb, struct genl_info *info)
if (err) if (err)
goto err_snapshot_create; goto err_snapshot_create;
if (!snapshot_id_attr) {
struct sk_buff *msg;
snapshot = devlink_region_snapshot_get_by_id(region,
snapshot_id);
if (WARN_ON(!snapshot))
return -EINVAL;
msg = devlink_nl_region_notify_build(region, snapshot,
DEVLINK_CMD_REGION_NEW,
info->snd_portid,
info->snd_seq);
err = PTR_ERR_OR_ZERO(msg);
if (err)
goto err_notify;
err = genlmsg_reply(msg, info);
if (err)
goto err_notify;
}
return 0; return 0;
err_snapshot_create: err_snapshot_create:
...@@ -4145,6 +4172,10 @@ devlink_nl_cmd_region_new(struct sk_buff *skb, struct genl_info *info) ...@@ -4145,6 +4172,10 @@ devlink_nl_cmd_region_new(struct sk_buff *skb, struct genl_info *info)
err_snapshot_capture: err_snapshot_capture:
__devlink_snapshot_id_decrement(devlink, snapshot_id); __devlink_snapshot_id_decrement(devlink, snapshot_id);
return err; return err;
err_notify:
devlink_region_snapshot_del(region, snapshot);
return err;
} }
static int devlink_nl_cmd_region_read_chunk_fill(struct sk_buff *msg, static int devlink_nl_cmd_region_read_chunk_fill(struct sk_buff *msg,
......
...@@ -151,6 +151,19 @@ regions_test() ...@@ -151,6 +151,19 @@ regions_test()
check_region_snapshot_count dummy post-second-delete 2 check_region_snapshot_count dummy post-second-delete 2
sid=$(devlink -j region new $DL_HANDLE/dummy | jq '.[][][][]')
check_err $? "Failed to create a new snapshot with id allocated by the kernel"
check_region_snapshot_count dummy post-first-request 3
devlink region dump $DL_HANDLE/dummy snapshot $sid >> /dev/null
check_err $? "Failed to dump a snapshot with id allocated by the kernel"
devlink region del $DL_HANDLE/dummy snapshot $sid
check_err $? "Failed to delete snapshot with id allocated by the kernel"
check_region_snapshot_count dummy post-first-request 2
log_test "regions test" log_test "regions test"
} }
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment