From ed93ec3907f063268ced18728d0653f6199d100c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 3 Mar 2009 14:48:35 -0500 Subject: [PATCH] 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 Reported-by: Alexander Beregalov Reviewed-by: Eric Sandeen Reviewed-by: Felix Blyakher Signed-off-by: Felix Blyakher --- fs/xfs/xfs_iget.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c index e2fb6210d4c5..478e587087fe 100644 --- a/fs/xfs/xfs_iget.c +++ b/fs/xfs/xfs_iget.c @@ -246,9 +246,6 @@ xfs_iget_cache_miss( 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 @@ xfs_iget_cache_miss( */ 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 @@ xfs_iget_cache_miss( 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: