xfs: Refactor xfs_isilocked()

Introduce a new __xfs_rwsem_islocked predicate to encapsulate checking
the state of a rw_semaphore, then refactor xfs_isilocked to use it.

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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index a835ceb..359e2cd 100644 (file)
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -343,9 +343,29 @@ 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)) {
@@ -360,15 +380,13 @@ 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 4b6703d..4b5202a 100644 (file)
--- 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 *);