1 files changed, 34 insertions, 3 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 5026c44a98e1..8edb7d049565 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1067,11 +1067,14 @@ static bool nfs_mapping_need_revalidate_inode(struct inode *inode)
 }
 
 /**
- * nfs_revalidate_mapping - Revalidate the pagecache
+ * __nfs_revalidate_mapping - Revalidate the pagecache
  * @inode - pointer to host inode
  * @mapping - pointer to mapping
+ * @may_lock - take inode->i_mutex?
  */
-int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
+static int __nfs_revalidate_mapping(struct inode *inode,
+                struct address_space *mapping,
+                bool may_lock)
 {
         struct nfs_inode *nfsi = NFS_I(inode);
         unsigned long *bitlock = &nfsi->flags;
@@ -1120,7 +1123,12 @@ int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
         nfsi->cache_validity &= ~NFS_INO_INVALID_DATA;
         spin_unlock(&inode->i_lock);
         trace_nfs_invalidate_mapping_enter(inode);
-        ret = nfs_invalidate_mapping(inode, mapping);
+        if (may_lock) {
+                mutex_lock(&inode->i_mutex);
+                ret = nfs_invalidate_mapping(inode, mapping);
+                mutex_unlock(&inode->i_mutex);
+        } else
+                ret = nfs_invalidate_mapping(inode, mapping);
         trace_nfs_invalidate_mapping_exit(inode, ret);
 
         clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
@@ -1130,6 +1138,29 @@ out:
         return ret;
 }
 
+/**
+ * nfs_revalidate_mapping - Revalidate the pagecache
+ * @inode - pointer to host inode
+ * @mapping - pointer to mapping
+ */
+int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
+{
+        return __nfs_revalidate_mapping(inode, mapping, false);
+}
+
+/**
+ * nfs_revalidate_mapping_protected - Revalidate the pagecache
+ * @inode - pointer to host inode
+ * @mapping - pointer to mapping
+ *
+ * Differs from nfs_revalidate_mapping() in that it grabs the inode->i_mutex
+ * while invalidating the mapping.
+ */
+int nfs_revalidate_mapping_protected(struct inode *inode, struct address_space *mapping)
+{
+        return __nfs_revalidate_mapping(inode, mapping, true);
+}
+
 static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 {
         struct nfs_inode *nfsi = NFS_I(inode);