1 files changed, 45 insertions, 2 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index caa26ab5ed68..540e3b43c688 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4016,12 +4016,19 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
         struct btrfs_root *sub_root = root;
         struct btrfs_key location;
         int index;
-        int ret;
+        int ret = 0;
 
         if (dentry->d_name.len > BTRFS_NAME_LEN)
                 return ERR_PTR(-ENAMETOOLONG);
 
-        ret = btrfs_inode_by_name(dir, dentry, &location);
+        if (unlikely(d_need_lookup(dentry))) {
+                memcpy(&location, dentry->d_fsdata, sizeof(struct btrfs_key));
+                kfree(dentry->d_fsdata);
+                dentry->d_fsdata = NULL;
+                d_clear_need_lookup(dentry);
+        } else {
+                ret = btrfs_inode_by_name(dir, dentry, &location);
+        }
 
         if (ret < 0)
                 return ERR_PTR(ret);
@@ -4076,6 +4083,12 @@ static int btrfs_dentry_delete(const struct dentry *dentry)
         return 0;
 }
 
+static void btrfs_dentry_release(struct dentry *dentry)
+{
+        if (dentry->d_fsdata)
+                kfree(dentry->d_fsdata);
+}
+
 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
                                    struct nameidata *nd)
 {
@@ -4098,6 +4111,7 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
         struct btrfs_path *path;
         struct list_head ins_list;
         struct list_head del_list;
+        struct qstr q;
         int ret;
         struct extent_buffer *leaf;
         int slot;
@@ -4187,6 +4201,7 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 
                 while (di_cur < di_total) {
                         struct btrfs_key location;
+                        struct dentry *tmp;
 
                         if (verify_dir_item(root, leaf, di))
                                 break;
@@ -4207,6 +4222,33 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
                         d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
                         btrfs_dir_item_key_to_cpu(leaf, di, &location);
 
+                        q.name = name_ptr;
+                        q.len = name_len;
+                        q.hash = full_name_hash(q.name, q.len);
+                        tmp = d_lookup(filp->f_dentry, &q);
+                        if (!tmp) {
+                                struct btrfs_key *newkey;
+
+                                newkey = kzalloc(sizeof(struct btrfs_key),
+                                                 GFP_NOFS);
+                                if (!newkey)
+                                        goto no_dentry;
+                                tmp = d_alloc(filp->f_dentry, &q);
+                                if (!tmp) {
+                                        kfree(newkey);
+                                        dput(tmp);
+                                        goto no_dentry;
+                                }
+                                memcpy(newkey, &location,
+                                       sizeof(struct btrfs_key));
+                                tmp->d_fsdata = newkey;
+                                tmp->d_flags |= DCACHE_NEED_LOOKUP;
+                                d_rehash(tmp);
+                                dput(tmp);
+                        } else {
+                                dput(tmp);
+                        }
+no_dentry:
                         /* is this a reference to our own snapshot? If so
                          * skip it
                          */
@@ -7452,4 +7494,5 @@ static const struct inode_operations btrfs_symlink_inode_operations = {
 
 const struct dentry_operations btrfs_dentry_operations = {
         .d_delete       = btrfs_dentry_delete,
+        .d_release      = btrfs_dentry_release,
 };