xfs: prevent lockdep false positive in xfs_iget_cache_miss
The inode can't be locked by anyone else as we just created it a few
lines above and it's not been added to any lookup data structure yet.
So use a trylock that must succeed to get around the lockdep warnings.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c
index e2fb621..478e587 100644
--- a/fs/xfs/xfs_iget.c
+++ b/fs/xfs/xfs_iget.c
@@ -246,9 +246,6 @@
goto out_destroy;
}
- if (lock_flags)
- xfs_ilock(ip, lock_flags);
-
/*
* Preload the radix tree so we can insert safely under the
* write spinlock. Note that we cannot sleep inside the preload
@@ -256,7 +253,16 @@
*/
if (radix_tree_preload(GFP_KERNEL)) {
error = EAGAIN;
- goto out_unlock;
+ goto out_destroy;
+ }
+
+ /*
+ * Because the inode hasn't been added to the radix-tree yet it can't
+ * be found by another thread, so we can do the non-sleeping lock here.
+ */
+ if (lock_flags) {
+ if (!xfs_ilock_nowait(ip, lock_flags))
+ BUG();
}
mask = ~(((XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_inodelog)) - 1);
@@ -284,7 +290,6 @@
out_preload_end:
write_unlock(&pag->pag_ici_lock);
radix_tree_preload_end();
-out_unlock:
if (lock_flags)
xfs_iunlock(ip, lock_flags);
out_destroy: