From: Jacob Keller <jacob.e.keller@intel.com>
Date: Thu, 26 Mar 2020 11:37:11 -0700
Subject: devlink: add function to take snapshot while locked
Patch-mainline: v5.7-rc1
Git-commit: cf80faee79f98c0608a86e9006af57a99ffad650
References: jsc#SLE-15171
A future change is going to add a new devlink command to request
a snapshot on demand. This function will want to call the
devlink_region_snapshot_create function while already holding the
devlink instance lock.
Extract the logic of this function into a static function prefixed by
`__` to indicate that it is an internal helper function. Modify the
original function to be implemented in terms of the new locked
function.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/core/devlink.c | 78 +++++++++++++++++++++++++++++++----------------------
1 file changed, 47 insertions(+), 31 deletions(-)
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -3767,6 +3767,52 @@ out_free_msg:
nlmsg_free(msg);
}
+/**
+ * __devlink_region_snapshot_create - create a new snapshot
+ * This will add a new snapshot of a region. The snapshot
+ * will be stored on the region struct and can be accessed
+ * from devlink. This is useful for future analyses of snapshots.
+ * Multiple snapshots can be created on a region.
+ * The @snapshot_id should be obtained using the getter function.
+ *
+ * Must be called only while holding the devlink instance lock.
+ *
+ * @region: devlink region of the snapshot
+ * @data: snapshot data
+ * @snapshot_id: snapshot id to be created
+ */
+static int
+__devlink_region_snapshot_create(struct devlink_region *region,
+ u8 *data, u32 snapshot_id)
+{
+ struct devlink *devlink = region->devlink;
+ struct devlink_snapshot *snapshot;
+
+ lockdep_assert_held(&devlink->lock);
+
+ /* check if region can hold one more snapshot */
+ if (region->cur_snapshots == region->max_snapshots)
+ return -ENOMEM;
+
+ if (devlink_region_snapshot_get_by_id(region, snapshot_id))
+ return -EEXIST;
+
+ snapshot = kzalloc(sizeof(*snapshot), GFP_KERNEL);
+ if (!snapshot)
+ return -ENOMEM;
+
+ snapshot->id = snapshot_id;
+ snapshot->region = region;
+ snapshot->data = data;
+
+ list_add_tail(&snapshot->list, ®ion->snapshot_list);
+
+ region->cur_snapshots++;
+
+ devlink_nl_region_notify(region, snapshot, DEVLINK_CMD_REGION_NEW);
+ return 0;
+}
+
static void devlink_region_snapshot_del(struct devlink_region *region,
struct devlink_snapshot *snapshot)
{
@@ -7731,42 +7777,12 @@ int devlink_region_snapshot_create(struc
u8 *data, u32 snapshot_id)
{
struct devlink *devlink = region->devlink;
- struct devlink_snapshot *snapshot;
int err;
mutex_lock(&devlink->lock);
-
- /* check if region can hold one more snapshot */
- if (region->cur_snapshots == region->max_snapshots) {
- err = -ENOMEM;
- goto unlock;
- }
-
- if (devlink_region_snapshot_get_by_id(region, snapshot_id)) {
- err = -EEXIST;
- goto unlock;
- }
-
- snapshot = kzalloc(sizeof(*snapshot), GFP_KERNEL);
- if (!snapshot) {
- err = -ENOMEM;
- goto unlock;
- }
-
- snapshot->id = snapshot_id;
- snapshot->region = region;
- snapshot->data = data;
-
- list_add_tail(&snapshot->list, ®ion->snapshot_list);
-
- region->cur_snapshots++;
-
- devlink_nl_region_notify(region, snapshot, DEVLINK_CMD_REGION_NEW);
+ err = __devlink_region_snapshot_create(region, data, snapshot_id);
mutex_unlock(&devlink->lock);
- return 0;
-unlock:
- mutex_unlock(&devlink->lock);
return err;
}
EXPORT_SYMBOL_GPL(devlink_region_snapshot_create);