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>
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 51b3040..84b8c46 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -48,8 +48,10 @@
return result;
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
list_for_each_entry(dentry, &result->d_inode->i_dentry, d_alias) {
dget_locked(dentry);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
if (toput)
dput(toput);
@@ -58,8 +60,10 @@
return dentry;
}
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
toput = dentry;
}
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
if (toput)