list_bl: don't use bit locks for PREEMPT_RT or lockdep
hash-bl nests spinlocks inside the bit locks. This causes problems
for CONFIG_PREEMPT_RT which converts spin locks to sleeping locks,
and we're not allowed to sleep while holding a spinning lock.
Further, lockdep does not support bit locks, so we lose lockdep
coverage of the inode hash table with the hash-bl conversion.
To enable these configs to work, add an external per-chain spinlock
to the hlist_bl_head() and add helpers to use this instead of the
bit spinlock when preempt_rt or lockdep are enabled.
This converts all users of hlist-bl to use the external spinlock in
these situations, so we also gain lockdep coverage of things like
the dentry cache hash table with this change.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
2 files changed
