[PATCH] xfs: improve xfs_isilocked

Christoph Hellwig
2010-05-27T19:03:11Z

Use rwsem_is_locked to make the assertations for shared locks work.

Signed-off-by: Christoph Hellwig <hch@lst.de>

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