fs: scale inode alias list

Add a new lock, dcache_inode_lock, to protect the inode's i_dentry list
from concurrent modification. d_alias is also protected by d_lock.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c
index 35e5f5a9ef59..c31b5c647ac7 100644
--- a/fs/ocfs2/dcache.c
+++ b/fs/ocfs2/dcache.c
@@ -170,7 +170,7 @@ struct dentry *ocfs2_find_local_alias(struct inode *inode,
         struct dentry *dentry = NULL;
 
         spin_lock(&dcache_lock);
-
+        spin_lock(&dcache_inode_lock);
         list_for_each(p, &inode->i_dentry) {
                 dentry = list_entry(p, struct dentry, d_alias);
 
@@ -188,6 +188,7 @@ struct dentry *ocfs2_find_local_alias(struct inode *inode,
                 dentry = NULL;
         }
 
+        spin_unlock(&dcache_inode_lock);
         spin_unlock(&dcache_lock);
 
         return dentry;