1 files changed, 35 insertions, 2 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index f594dac436a7..f7e4a88d5d92 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1074,6 +1074,8 @@ static int readdir_search_pagecache(struct nfs_readdir_descriptor *desc)
 	return res;
 }
 
+#define NFS_READDIR_CACHE_MISS_THRESHOLD (16UL)
+
 /*
  * Once we've found the start of the dirent within a page: fill 'er up...
  */
@@ -1083,6 +1085,7 @@ static void nfs_do_filldir(struct nfs_readdir_descriptor *desc,
 	struct file	*file = desc->file;
 	struct nfs_cache_array *array;
 	unsigned int i;
+	bool first_emit = !desc->dir_cookie;
 
 	array = kmap_local_page(desc->page);
 	for (i = desc->cache_entry_index; i < array->size; i++) {
@@ -1106,6 +1109,10 @@ static void nfs_do_filldir(struct nfs_readdir_descriptor *desc,
 			desc->ctx->pos = desc->dir_cookie;
 		else
 			desc->ctx->pos++;
+		if (first_emit && i > NFS_READDIR_CACHE_MISS_THRESHOLD + 1) {
+			desc->eob = true;
+			break;
+		}
 	}
 	if (array->page_is_eof)
 		desc->eof = !desc->eob;
@@ -1187,8 +1194,6 @@ out:
 	return status;
 }
 
-#define NFS_READDIR_CACHE_MISS_THRESHOLD (16UL)
-
 static bool nfs_readdir_handle_cache_misses(struct inode *inode,
 					    struct nfs_readdir_descriptor *desc,
 					    unsigned int cache_misses,
@@ -2948,9 +2953,30 @@ static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, co
 	return NULL;
 }
 
+static u64 nfs_access_login_time(const struct task_struct *task,
+				 const struct cred *cred)
+{
+	const struct task_struct *parent;
+	const struct cred *pcred;
+	u64 ret;
+
+	rcu_read_lock();
+	for (;;) {
+		parent = rcu_dereference(task->real_parent);
+		pcred = rcu_dereference(parent->cred);
+		if (parent == task || cred_fscmp(pcred, cred) != 0)
+			break;
+		task = parent;
+	}
+	ret = task->start_time;
+	rcu_read_unlock();
+	return ret;
+}
+
 static int nfs_access_get_cached_locked(struct inode *inode, const struct cred *cred, u32 *mask, bool may_block)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
+	u64 login_time = nfs_access_login_time(current, cred);
 	struct nfs_access_entry *cache;
 	bool retry = true;
 	int err;
@@ -2978,6 +3004,9 @@ static int nfs_access_get_cached_locked(struct inode *inode, const struct cred *
 		spin_lock(&inode->i_lock);
 		retry = false;
 	}
+	err = -ENOENT;
+	if ((s64)(login_time - cache->timestamp) > 0)
+		goto out;
 	*mask = cache->mask;
 	list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
 	err = 0;
@@ -2996,6 +3025,7 @@ static int nfs_access_get_cached_rcu(struct inode *inode, const struct cred *cre
 	 * but do it without locking.
 	 */
 	struct nfs_inode *nfsi = NFS_I(inode);
+	u64 login_time = nfs_access_login_time(current, cred);
 	struct nfs_access_entry *cache;
 	int err = -ECHILD;
 	struct list_head *lh;
@@ -3010,6 +3040,8 @@ static int nfs_access_get_cached_rcu(struct inode *inode, const struct cred *cre
 		cache = NULL;
 	if (cache == NULL)
 		goto out;
+	if ((s64)(login_time - cache->timestamp) > 0)
+		goto out;
 	if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS))
 		goto out;
 	*mask = cache->mask;
@@ -3057,6 +3089,7 @@ static void nfs_access_add_rbtree(struct inode *inode,
 		else
 			goto found;
 	}
+	set->timestamp = ktime_get_ns();
 	rb_link_node(&set->rb_node, parent, p);
 	rb_insert_color(&set->rb_node, root_node);
 	list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);