On Fri, Feb 14, 2020 at 07:59:39PM +0100, Pavel Reichl wrote:
> Refactor xfs_isilocked() to use newly introduced __xfs_rwsem_islocked().
> __xfs_rwsem_islocked() is a helper function which encapsulates checking
> state of rw_semaphores hold by inode.
>
> Signed-off-by: Pavel Reichl <preichl@xxxxxxxxxx>
> Suggested-by: Dave Chinner <dchinner@xxxxxxxxxx>
> Suggested-by: Eric Sandeen <sandeen@xxxxxxxxxx>
> ---
> fs/xfs/xfs_inode.c | 54 ++++++++++++++++++++++++++++++++--------------
> fs/xfs/xfs_inode.h | 2 +-
> 2 files changed, 39 insertions(+), 17 deletions(-)
>
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index c5077e6326c7..3d28c4790231 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -345,32 +345,54 @@ xfs_ilock_demote(
> }
>
> #if defined(DEBUG) || defined(XFS_WARN)
> -int
> +static inline bool
> +__xfs_rwsem_islocked(
> + struct rw_semaphore *rwsem,
> + bool shared,
> + bool excl)
> +{
> + bool locked = false;
> +
> + if (!rwsem_is_locked(rwsem))
> + return false;
> +
> + if (!debug_locks)
> + return true;
> +
> + if (shared)
> + locked = lockdep_is_held_type(rwsem, 0);
> +
> + if (excl)
> + locked |= lockdep_is_held_type(rwsem, 1);
> +
> + return locked;
This could use some comments explaining the logic, especially why we
need the shared and excl flags, which seems very confusing given that
a lock can be held either shared or exclusive, but not neither and not
both.
