[PATCH] xfs: improve xfs_isilocked

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

Use rwsem_is_locked to make the assertations for shared locks work.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>

Index: xfs/fs/xfs/xfs_iget.c
===================================================================
--- xfs.orig/fs/xfs/xfs_iget.c  2010-05-25 11:40:59.216005587 +0200
+++ xfs/fs/xfs/xfs_iget.c       2010-05-27 20:59:09.244004330 +0200
@@ -740,30 +738,24 @@ xfs_ilock_demote(
 }
 
 #ifdef DEBUG
-/*
- * Debug-only routine, without additional rw_semaphore APIs, we can
- * now only answer requests regarding whether we hold the lock for write
- * (reader state is outside our visibility, we only track writer state).
- *
- * Note: this means !xfs_isilocked would give false positives, so don't do 
that.
- */
 int
 xfs_isilocked(
        xfs_inode_t             *ip,
        uint                    lock_flags)
 {
-       if ((lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) ==
-                       XFS_ILOCK_EXCL) {
-               if (!ip->i_lock.mr_writer)
-                       return 0;
+       if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) {
+               if (!(lock_flags & XFS_ILOCK_SHARED))
+                       return !!ip->i_lock.mr_writer;
+               return rwsem_is_locked(&ip->i_lock.mr_lock);
        }
 
-       if ((lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) ==
-                       XFS_IOLOCK_EXCL) {
-               if (!ip->i_iolock.mr_writer)
-                       return 0;
+       if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) {
+               if (!(lock_flags & XFS_IOLOCK_SHARED))
+                       return !!ip->i_iolock.mr_writer;
+               return rwsem_is_locked(&ip->i_iolock.mr_lock);
        }
 
-       return 1;
+       ASSERT(0);
+       return 0;
 }
 #endif