Re: [PATCH 07/14] xfs: Refactor xfs_isilocked()

Darrick J. Wong
2021-06-17T16:16:52Z

On Tue, Jun 15, 2021 at 11:17:57AM +0200, Jan Kara wrote:
> From: Pavel Reichl <preichl@redhat.com>
>
> 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@redhat.com>
> Suggested-by: Dave Chinner <dchinner@redhat.com>
> Suggested-by: Eric Sandeen <sandeen@redhat.com>
> Suggested-by: Darrick J. Wong <darrick.wong@oracle.com>
> Signed-off-by: Jan Kara <jack@suse.cz>

With the commit message updated,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
> fs/xfs/xfs_inode.c | 34 ++++++++++++++++++++++++++--------
> fs/xfs/xfs_inode.h | 2 +-
> 2 files changed, 27 insertions(+), 9 deletions(-)
>
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index e4c2da4566f1..ffd47217a8fa 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -342,9 +342,29 @@ xfs_ilock_demote(
> }
>
> #if defined(DEBUG) || defined(XFS_WARN)
> -int
> +static inline bool
> +__xfs_rwsem_islocked(
> + struct rw_semaphore *rwsem,
> + bool shared)
> +{
> + if (!debug_locks)
> + return rwsem_is_locked(rwsem);
> +
> + if (!shared)
> + return lockdep_is_held_type(rwsem, 0);
> +
> + /*
> + * We are checking that the lock is held at least in shared
> + * mode but don't care that it might be held exclusively
> + * (i.e. shared | excl). Hence we check if the lock is held
> + * in any mode rather than an explicit shared mode.
> + */
> + return lockdep_is_held_type(rwsem, -1);
> +}
> +
> +bool
> xfs_isilocked(
> - xfs_inode_t *ip,
> + struct xfs_inode *ip,
> uint lock_flags)
> {
> if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) {
> @@ -359,15 +379,13 @@ xfs_isilocked(
> return rwsem_is_locked(&ip->i_mmaplock.mr_lock);
> }
>
> - if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) {
> - if (!(lock_flags & XFS_IOLOCK_SHARED))
> - return !debug_locks ||
> - lockdep_is_held_type(&VFS_I(ip)->i_rwsem, 0);
> - return rwsem_is_locked(&VFS_I(ip)->i_rwsem);
> + if (lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) {
> + return __xfs_rwsem_islocked(&VFS_I(ip)->i_rwsem,
> + (lock_flags & XFS_IOLOCK_SHARED));
> }
>
> ASSERT(0);
> - return 0;
> + return false;
> }
> #endif
>
> diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
> index ca826cfba91c..4659e1568966 100644
> --- a/fs/xfs/xfs_inode.h
> +++ b/fs/xfs/xfs_inode.h
> @@ -410,7 +410,7 @@ void xfs_ilock(xfs_inode_t *, uint);
> int xfs_ilock_nowait(xfs_inode_t *, uint);
> void xfs_iunlock(xfs_inode_t *, uint);
> void xfs_ilock_demote(xfs_inode_t *, uint);
> -int xfs_isilocked(xfs_inode_t *, uint);
> +bool xfs_isilocked(struct xfs_inode *, uint);
> uint xfs_ilock_data_map_shared(struct xfs_inode *);
> uint xfs_ilock_attr_map_shared(struct xfs_inode *);
>
> --
> 2.26.2
>