diff options
| author | Jiri Pirko <jiri@nvidia.com> | 2022-07-29 10:10:35 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-08-01 14:14:00 +0300 |
| commit | c2368b19807affd7621f7c4638cd2e17fec13021 (patch) | |
| tree | 38c720776e02ac404d0ac9e53cb64aa581c8f2f9 | |
| parent | 02a7cb2866dd6e3ac7645b594289e1c308b68c4e (diff) | |
| download | linux-c2368b19807affd7621f7c4638cd2e17fec13021.tar.xz | |
net: devlink: introduce "unregistering" mark and use it during devlinks iteration
Add new mark called "unregistering" to be set at the beginning of
devlink_unregister() function. Check this mark during devlinks
iteration in order to prevent getting a reference of devlink which is
being currently unregistered.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/core/devlink.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/net/core/devlink.c b/net/core/devlink.c index c43c96554a3e..6b20196ada1a 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -207,6 +207,7 @@ static const struct nla_policy devlink_selftest_nl_policy[DEVLINK_ATTR_SELFTEST_ static DEFINE_XARRAY_FLAGS(devlinks, XA_FLAGS_ALLOC); #define DEVLINK_REGISTERED XA_MARK_1 +#define DEVLINK_UNREGISTERING XA_MARK_2 /* devlink instances are open to the access from the user space after * devlink_register() call. Such logical barrier allows us to have certain @@ -305,6 +306,14 @@ retry: devlink = xa_find_fn(&devlinks, indexp, ULONG_MAX, DEVLINK_REGISTERED); if (!devlink) goto unlock; + + /* In case devlink_unregister() was already called and "unregistering" + * mark was set, do not allow to get a devlink reference here. + * This prevents live-lock of devlink_unregister() wait for completion. + */ + if (xa_get_mark(&devlinks, *indexp, DEVLINK_UNREGISTERING)) + goto retry; + /* For a possible retry, the xa_find_after() should be always used */ xa_find_fn = xa_find_after; if (!devlink_try_get(devlink)) @@ -9809,11 +9818,13 @@ void devlink_unregister(struct devlink *devlink) ASSERT_DEVLINK_REGISTERED(devlink); /* Make sure that we are in .remove() routine */ + xa_set_mark(&devlinks, devlink->index, DEVLINK_UNREGISTERING); devlink_put(devlink); wait_for_completion(&devlink->comp); devlink_notify_unregister(devlink); xa_clear_mark(&devlinks, devlink->index, DEVLINK_REGISTERED); + xa_clear_mark(&devlinks, devlink->index, DEVLINK_UNREGISTERING); } EXPORT_SYMBOL_GPL(devlink_unregister); |