found_key);
 }
 
+int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
+                         u64 start_off, struct btrfs_path *path,
+                         struct btrfs_inode_extref **ret_extref,
+                         u64 *found_off)
+{
+       int ret, slot;
+       struct btrfs_key key;
+       struct btrfs_key found_key;
+       struct btrfs_inode_extref *extref;
+       struct extent_buffer *leaf;
+       unsigned long ptr;
+
+       key.objectid = inode_objectid;
+       btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY);
+       key.offset = start_off;
+
+       ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+       if (ret < 0)
+               return ret;
+
+       while (1) {
+               leaf = path->nodes[0];
+               slot = path->slots[0];
+               if (slot >= btrfs_header_nritems(leaf)) {
+                       /*
+                        * If the item at offset is not found,
+                        * btrfs_search_slot will point us to the slot
+                        * where it should be inserted. In our case
+                        * that will be the slot directly before the
+                        * next INODE_REF_KEY_V2 item. In the case
+                        * that we're pointing to the last slot in a
+                        * leaf, we must move one leaf over.
+                        */
+                       ret = btrfs_next_leaf(root, path);
+                       if (ret) {
+                               if (ret >= 1)
+                                       ret = -ENOENT;
+                               break;
+                       }
+                       continue;
+               }
+
+               btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
+               /*
+                * Check that we're still looking at an extended ref key for
+                * this particular objectid. If we have different
+                * objectid or type then there are no more to be found
+                * in the tree and we can exit.
+                */
+               ret = -ENOENT;
+               if (found_key.objectid != inode_objectid)
+                       break;
+               if (btrfs_key_type(&found_key) != BTRFS_INODE_EXTREF_KEY)
+                       break;
+
+               ret = 0;
+               ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+               extref = (struct btrfs_inode_extref *)ptr;
+               *ret_extref = extref;
+               if (found_off)
+                       *found_off = found_key.offset;
+               break;
+       }
+
+       return ret;
+}
+
 /*
  * this iterates to turn a btrfs_inode_ref into a full filesystem path. elements
  * of the path are separated by '/' and the path is guaranteed to be
 
                                        struct btrfs_path *path);
 void free_ipath(struct inode_fs_paths *ipath);
 
+int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
+                         u64 start_off, struct btrfs_path *path,
+                         struct btrfs_inode_extref **ret_extref,
+                         u64 *found_off);
+
 #endif
 
  */
 #define BTRFS_NAME_LEN 255
 
+/*
+ * Theoretical limit is larger, but we keep this down to a sane
+ * value. That should limit greatly the possibility of collisions on
+ * inode ref items.
+ */
+#define BTRFS_LINK_MAX 65535U
+
 /* 32 bytes in various csum fields */
 #define BTRFS_CSUM_SIZE 32
 
  */
 #define BTRFS_FEATURE_INCOMPAT_BIG_METADATA    (1ULL << 5)
 
+#define BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF   (1ULL << 6)
+
 #define BTRFS_FEATURE_COMPAT_SUPP              0ULL
 #define BTRFS_FEATURE_COMPAT_RO_SUPP           0ULL
 #define BTRFS_FEATURE_INCOMPAT_SUPP                    \
         BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL |        \
         BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS |          \
         BTRFS_FEATURE_INCOMPAT_BIG_METADATA |          \
-        BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO)
+        BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO |          \
+        BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
 
 /*
  * A leaf is full of items. offset and size tell us where to find
        /* name goes here */
 } __attribute__ ((__packed__));
 
+struct btrfs_inode_extref {
+       __le64 parent_objectid;
+       __le64 index;
+       __le16 name_len;
+       __u8   name[0];
+       /* name goes here */
+} __attribute__ ((__packed__));
+
 struct btrfs_timespec {
        __le64 sec;
        __le32 nsec;
  */
 #define BTRFS_INODE_ITEM_KEY           1
 #define BTRFS_INODE_REF_KEY            12
+#define BTRFS_INODE_EXTREF_KEY         13
 #define BTRFS_XATTR_ITEM_KEY           24
 #define BTRFS_ORPHAN_ITEM_KEY          48
 /* reserve 2-15 close to the inode for later flexibility */
 BTRFS_SETGET_FUNCS(inode_ref_name_len, struct btrfs_inode_ref, name_len, 16);
 BTRFS_SETGET_FUNCS(inode_ref_index, struct btrfs_inode_ref, index, 64);
 
+/* struct btrfs_inode_extref */
+BTRFS_SETGET_FUNCS(inode_extref_parent, struct btrfs_inode_extref,
+                  parent_objectid, 64);
+BTRFS_SETGET_FUNCS(inode_extref_name_len, struct btrfs_inode_extref,
+                  name_len, 16);
+BTRFS_SETGET_FUNCS(inode_extref_index, struct btrfs_inode_extref, index, 64);
+
 /* struct btrfs_inode_item */
 BTRFS_SETGET_FUNCS(inode_generation, struct btrfs_inode_item, generation, 64);
 BTRFS_SETGET_FUNCS(inode_sequence, struct btrfs_inode_item, sequence, 64);
                           struct btrfs_root *root,
                           const char *name, int name_len,
                           u64 inode_objectid, u64 ref_objectid, u64 *index);
-struct btrfs_inode_ref *
-btrfs_lookup_inode_ref(struct btrfs_trans_handle *trans,
-                       struct btrfs_root *root,
-                       struct btrfs_path *path,
-                       const char *name, int name_len,
-                       u64 inode_objectid, u64 ref_objectid, int mod);
+int btrfs_get_inode_ref_index(struct btrfs_trans_handle *trans,
+                             struct btrfs_root *root,
+                             struct btrfs_path *path,
+                             const char *name, int name_len,
+                             u64 inode_objectid, u64 ref_objectid, int mod,
+                             u64 *ret_index);
 int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root,
                             struct btrfs_path *path, u64 objectid);
                       *root, struct btrfs_path *path,
                       struct btrfs_key *location, int mod);
 
+struct btrfs_inode_extref *
+btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
+                         struct btrfs_root *root,
+                         struct btrfs_path *path,
+                         const char *name, int name_len,
+                         u64 inode_objectid, u64 ref_objectid, int ins_len,
+                         int cow);
+
+int btrfs_find_name_in_ext_backref(struct btrfs_path *path,
+                                  u64 ref_objectid, const char *name,
+                                  int name_len,
+                                  struct btrfs_inode_extref **extref_ret);
+
 /* file-item.c */
 int btrfs_del_csums(struct btrfs_trans_handle *trans,
                    struct btrfs_root *root, u64 bytenr, u64 len);
 
 {
        return crc32c((u32)~1, name, len);
 }
+
+/*
+ * Figure the key offset of an extended inode ref
+ */
+static inline u64 btrfs_extref_hash(u64 parent_objectid, const char *name,
+                                   int len)
+{
+       return (u64) crc32c(parent_objectid, name, len);
+}
+
 #endif
 
 
 #include "ctree.h"
 #include "disk-io.h"
+#include "hash.h"
 #include "transaction.h"
 #include "print-tree.h"
 
        return 0;
 }
 
-struct btrfs_inode_ref *
+int btrfs_find_name_in_ext_backref(struct btrfs_path *path, u64 ref_objectid,
+                                  const char *name, int name_len,
+                                  struct btrfs_inode_extref **extref_ret)
+{
+       struct extent_buffer *leaf;
+       struct btrfs_inode_extref *extref;
+       unsigned long ptr;
+       unsigned long name_ptr;
+       u32 item_size;
+       u32 cur_offset = 0;
+       int ref_name_len;
+
+       leaf = path->nodes[0];
+       item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+       ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+
+       /*
+        * Search all extended backrefs in this item. We're only
+        * looking through any collisions so most of the time this is
+        * just going to compare against one buffer. If all is well,
+        * we'll return success and the inode ref object.
+        */
+       while (cur_offset < item_size) {
+               extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
+               name_ptr = (unsigned long)(&extref->name);
+               ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
+
+               if (ref_name_len == name_len &&
+                   btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
+                   (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) {
+                       if (extref_ret)
+                               *extref_ret = extref;
+                       return 1;
+               }
+
+               cur_offset += ref_name_len + sizeof(*extref);
+       }
+       return 0;
+}
+
+static struct btrfs_inode_ref *
 btrfs_lookup_inode_ref(struct btrfs_trans_handle *trans,
-                       struct btrfs_root *root,
-                       struct btrfs_path *path,
-                       const char *name, int name_len,
-                       u64 inode_objectid, u64 ref_objectid, int mod)
+                      struct btrfs_root *root,
+                      struct btrfs_path *path,
+                      const char *name, int name_len,
+                      u64 inode_objectid, u64 ref_objectid, int ins_len,
+                      int cow)
 {
+       int ret;
        struct btrfs_key key;
        struct btrfs_inode_ref *ref;
-       int ins_len = mod < 0 ? -1 : 0;
-       int cow = mod != 0;
-       int ret;
 
        key.objectid = inode_objectid;
        key.type = BTRFS_INODE_REF_KEY;
        return ref;
 }
 
-int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
+/* Returns NULL if no extref found */
+struct btrfs_inode_extref *
+btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
+                         struct btrfs_root *root,
+                         struct btrfs_path *path,
+                         const char *name, int name_len,
+                         u64 inode_objectid, u64 ref_objectid, int ins_len,
+                         int cow)
+{
+       int ret;
+       struct btrfs_key key;
+       struct btrfs_inode_extref *extref;
+
+       key.objectid = inode_objectid;
+       key.type = BTRFS_INODE_EXTREF_KEY;
+       key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+
+       ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+       if (ret < 0)
+               return ERR_PTR(ret);
+       if (ret > 0)
+               return NULL;
+       if (!btrfs_find_name_in_ext_backref(path, ref_objectid, name, name_len, &extref))
+               return NULL;
+       return extref;
+}
+
+int btrfs_get_inode_ref_index(struct btrfs_trans_handle *trans,
+                             struct btrfs_root *root,
+                             struct btrfs_path *path,
+                             const char *name, int name_len,
+                             u64 inode_objectid, u64 ref_objectid, int mod,
+                             u64 *ret_index)
+{
+       struct btrfs_inode_ref *ref;
+       struct btrfs_inode_extref *extref;
+       int ins_len = mod < 0 ? -1 : 0;
+       int cow = mod != 0;
+
+       ref = btrfs_lookup_inode_ref(trans, root, path, name, name_len,
+                                    inode_objectid, ref_objectid, ins_len,
+                                    cow);
+       if (IS_ERR(ref))
+               return PTR_ERR(ref);
+
+       if (ref != NULL) {
+               *ret_index = btrfs_inode_ref_index(path->nodes[0], ref);
+               return 0;
+       }
+
+       btrfs_release_path(path);
+
+       extref = btrfs_lookup_inode_extref(trans, root, path, name,
+                                          name_len, inode_objectid,
+                                          ref_objectid, ins_len, cow);
+       if (IS_ERR(extref))
+               return PTR_ERR(extref);
+
+       if (extref) {
+               *ret_index = btrfs_inode_extref_index(path->nodes[0], extref);
+               return 0;
+       }
+
+       return -ENOENT;
+}
+
+int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           const char *name, int name_len,
                           u64 inode_objectid, u64 ref_objectid, u64 *index)
+{
+       struct btrfs_path *path;
+       struct btrfs_key key;
+       struct btrfs_inode_extref *extref;
+       struct extent_buffer *leaf;
+       int ret;
+       int del_len = name_len + sizeof(*extref);
+       unsigned long ptr;
+       unsigned long item_start;
+       u32 item_size;
+
+       key.objectid = inode_objectid;
+       btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY);
+       key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       path->leave_spinning = 1;
+
+       ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+       if (ret > 0)
+               ret = -ENOENT;
+       if (ret < 0)
+               goto out;
+
+       /*
+        * Sanity check - did we find the right item for this name?
+        * This should always succeed so error here will make the FS
+        * readonly.
+        */
+       if (!btrfs_find_name_in_ext_backref(path, ref_objectid,
+                                           name, name_len, &extref)) {
+               btrfs_std_error(root->fs_info, -ENOENT);
+               ret = -EROFS;
+               goto out;
+       }
+
+       leaf = path->nodes[0];
+       item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+       if (index)
+               *index = btrfs_inode_extref_index(leaf, extref);
+
+       if (del_len == item_size) {
+               /*
+                * Common case only one ref in the item, remove the
+                * whole item.
+                */
+               ret = btrfs_del_item(trans, root, path);
+               goto out;
+       }
+
+       ptr = (unsigned long)extref;
+       item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
+
+       memmove_extent_buffer(leaf, ptr, ptr + del_len,
+                             item_size - (ptr + del_len - item_start));
+
+       btrfs_truncate_item(trans, root, path, item_size - del_len, 1);
+
+out:
+       btrfs_free_path(path);
+
+       return ret;
+}
+
+int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
+                       struct btrfs_root *root,
+                       const char *name, int name_len,
+                       u64 inode_objectid, u64 ref_objectid, u64 *index)
 {
        struct btrfs_path *path;
        struct btrfs_key key;
        u32 item_size;
        u32 sub_item_len;
        int ret;
+       int search_ext_refs = 0;
        int del_len = name_len + sizeof(*ref);
 
        key.objectid = inode_objectid;
        ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
        if (ret > 0) {
                ret = -ENOENT;
+               search_ext_refs = 1;
                goto out;
        } else if (ret < 0) {
                goto out;
        }
        if (!find_name_in_backref(path, name, name_len, &ref)) {
                ret = -ENOENT;
+               search_ext_refs = 1;
                goto out;
        }
        leaf = path->nodes[0];
        item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
        memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
                              item_size - (ptr + sub_item_len - item_start));
-       btrfs_truncate_item(trans, root, path,
-                                 item_size - sub_item_len, 1);
+       btrfs_truncate_item(trans, root, path, item_size - sub_item_len, 1);
+out:
+       btrfs_free_path(path);
+
+       if (search_ext_refs) {
+               /*
+                * No refs were found, or we could not find the
+                * name in our ref array. Find and remove the extended
+                * inode ref then.
+                */
+               return btrfs_del_inode_extref(trans, root, name, name_len,
+                                             inode_objectid, ref_objectid, index);
+       }
+
+       return ret;
+}
+
+/*
+ * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
+ *
+ * The caller must have checked against BTRFS_LINK_MAX already.
+ */
+static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
+                                    struct btrfs_root *root,
+                                    const char *name, int name_len,
+                                    u64 inode_objectid, u64 ref_objectid, u64 index)
+{
+       struct btrfs_inode_extref *extref;
+       int ret;
+       int ins_len = name_len + sizeof(*extref);
+       unsigned long ptr;
+       struct btrfs_path *path;
+       struct btrfs_key key;
+       struct extent_buffer *leaf;
+       struct btrfs_item *item;
+
+       key.objectid = inode_objectid;
+       key.type = BTRFS_INODE_EXTREF_KEY;
+       key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       path->leave_spinning = 1;
+       ret = btrfs_insert_empty_item(trans, root, path, &key,
+                                     ins_len);
+       if (ret == -EEXIST) {
+               if (btrfs_find_name_in_ext_backref(path, ref_objectid,
+                                                  name, name_len, NULL))
+                       goto out;
+
+               btrfs_extend_item(trans, root, path, ins_len);
+               ret = 0;
+       }
+       if (ret < 0)
+               goto out;
+
+       leaf = path->nodes[0];
+       item = btrfs_item_nr(leaf, path->slots[0]);
+       ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
+       ptr += btrfs_item_size(leaf, item) - ins_len;
+       extref = (struct btrfs_inode_extref *)ptr;
+
+       btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
+       btrfs_set_inode_extref_index(path->nodes[0], extref, index);
+       btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
+
+       ptr = (unsigned long)&extref->name;
+       write_extent_buffer(path->nodes[0], name, ptr, name_len);
+       btrfs_mark_buffer_dirty(path->nodes[0]);
+
 out:
        btrfs_free_path(path);
        return ret;
 
 out:
        btrfs_free_path(path);
+
+       if (ret == -EMLINK) {
+               struct btrfs_super_block *disk_super = root->fs_info->super_copy;
+               /* We ran out of space in the ref array. Need to
+                * add an extended ref. */
+               if (btrfs_super_incompat_flags(disk_super)
+                   & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
+                       ret = btrfs_insert_inode_extref(trans, root, name,
+                                                       name_len,
+                                                       inode_objectid,
+                                                       ref_objectid, index);
+       }
+
        return ret;
 }
 
 
        struct btrfs_trans_handle *trans;
        struct btrfs_root *root = BTRFS_I(dir)->root;
        struct btrfs_path *path;
-       struct btrfs_inode_ref *ref;
        struct btrfs_dir_item *di;
        struct inode *inode = dentry->d_inode;
        u64 index;
        }
        btrfs_release_path(path);
 
-       ref = btrfs_lookup_inode_ref(trans, root, path,
-                               dentry->d_name.name, dentry->d_name.len,
-                               ino, dir_ino, 0);
-       if (IS_ERR(ref)) {
-               err = PTR_ERR(ref);
+       ret = btrfs_get_inode_ref_index(trans, root, path, dentry->d_name.name,
+                                       dentry->d_name.len, ino, dir_ino, 0,
+                                       &index);
+       if (ret) {
+               err = ret;
                goto out;
        }
-       BUG_ON(!ref); /* Logic error */
+
        if (check_path_shared(root, path))
                goto out;
-       index = btrfs_inode_ref_index(path->nodes[0], ref);
+
        btrfs_release_path(path);
 
        /*
        btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
        key[0].offset = 0;
 
+       /*
+        * Start new inodes with an inode_ref. This is slightly more
+        * efficient for small numbers of hard links since they will
+        * be packed into one item. Extended refs will kick in if we
+        * add more hard links than can fit in the ref item.
+        */
        key[1].objectid = objectid;
        btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
        key[1].offset = ref_objectid;
        if (root->objectid != BTRFS_I(inode)->root->objectid)
                return -EXDEV;
 
-       if (inode->i_nlink == ~0U)
+       if (inode->i_nlink >= BTRFS_LINK_MAX)
                return -EMLINK;
 
        err = btrfs_set_inode_index(dir, &index);
 
 #include "disk-io.h"
 #include "locking.h"
 #include "print-tree.h"
+#include "backref.h"
 #include "compat.h"
 #include "tree-log.h"
+#include "hash.h"
 
 /* magic values for the inode_only field in btrfs_log_inode:
  *
  */
 static noinline int backref_in_log(struct btrfs_root *log,
                                   struct btrfs_key *key,
+                                  u64 ref_objectid,
                                   char *name, int namelen)
 {
        struct btrfs_path *path;
        if (ret != 0)
                goto out;
 
-       item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
        ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
+
+       if (key->type == BTRFS_INODE_EXTREF_KEY) {
+               if (btrfs_find_name_in_ext_backref(path, ref_objectid,
+                                                  name, namelen, NULL))
+                       match = 1;
+
+               goto out;
+       }
+
+       item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
        ptr_end = ptr + item_size;
        while (ptr < ptr_end) {
                ref = (struct btrfs_inode_ref *)ptr;
                                  struct btrfs_path *path,
                                  struct btrfs_root *log_root,
                                  struct inode *dir, struct inode *inode,
-                                 struct btrfs_key *key,
                                  struct extent_buffer *eb,
-                                 struct btrfs_inode_ref *ref,
-                                 char *name, int namelen, int *search_done)
+                                 u64 inode_objectid, u64 parent_objectid,
+                                 u64 ref_index, char *name, int namelen,
+                                 int *search_done)
 {
        int ret;
+       char *victim_name;
+       int victim_name_len;
+       struct extent_buffer *leaf;
        struct btrfs_dir_item *di;
+       struct btrfs_key search_key;
+       struct btrfs_inode_extref *extref;
 
-       ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+again:
+       /* Search old style refs */
+       search_key.objectid = inode_objectid;
+       search_key.type = BTRFS_INODE_REF_KEY;
+       search_key.offset = parent_objectid;
+       ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
        if (ret == 0) {
-               char *victim_name;
-               int victim_name_len;
                struct btrfs_inode_ref *victim_ref;
                unsigned long ptr;
                unsigned long ptr_end;
-               struct extent_buffer *leaf = path->nodes[0];
+
+               leaf = path->nodes[0];
 
                /* are we trying to overwrite a back ref for the root directory
                 * if so, just jump out, we're done
                 */
-               if (key->objectid == key->offset)
+               if (search_key.objectid == search_key.offset)
                        return 1;
 
                /* check all the names in this back reference to see
                                           (unsigned long)(victim_ref + 1),
                                           victim_name_len);
 
-                       if (!backref_in_log(log_root, key, victim_name,
+                       if (!backref_in_log(log_root, &search_key,
+                                           parent_objectid,
+                                           victim_name,
                                            victim_name_len)) {
                                btrfs_inc_nlink(inode);
                                btrfs_release_path(path);
                                ret = btrfs_unlink_inode(trans, root, dir,
                                                         inode, victim_name,
                                                         victim_name_len);
+                               BUG_ON(ret);
                                btrfs_run_delayed_items(trans, root);
+                               kfree(victim_name);
+                               *search_done = 1;
+                               goto again;
                        }
                        kfree(victim_name);
+
                        ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
                }
                BUG_ON(ret);
        }
        btrfs_release_path(path);
 
+       /* Same search but for extended refs */
+       extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen,
+                                          inode_objectid, parent_objectid, 0,
+                                          0);
+       if (!IS_ERR_OR_NULL(extref)) {
+               u32 item_size;
+               u32 cur_offset = 0;
+               unsigned long base;
+               struct inode *victim_parent;
+
+               leaf = path->nodes[0];
+
+               item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+               base = btrfs_item_ptr_offset(leaf, path->slots[0]);
+
+               while (cur_offset < item_size) {
+                       extref = (struct btrfs_inode_extref *)base + cur_offset;
+
+                       victim_name_len = btrfs_inode_extref_name_len(leaf, extref);
+
+                       if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
+                               goto next;
+
+                       victim_name = kmalloc(victim_name_len, GFP_NOFS);
+                       read_extent_buffer(leaf, victim_name, (unsigned long)&extref->name,
+                                          victim_name_len);
+
+                       search_key.objectid = inode_objectid;
+                       search_key.type = BTRFS_INODE_EXTREF_KEY;
+                       search_key.offset = btrfs_extref_hash(parent_objectid,
+                                                             victim_name,
+                                                             victim_name_len);
+                       ret = 0;
+                       if (!backref_in_log(log_root, &search_key,
+                                           parent_objectid, victim_name,
+                                           victim_name_len)) {
+                               ret = -ENOENT;
+                               victim_parent = read_one_inode(root,
+                                                              parent_objectid);
+                               if (victim_parent) {
+                                       btrfs_inc_nlink(inode);
+                                       btrfs_release_path(path);
+
+                                       ret = btrfs_unlink_inode(trans, root,
+                                                                victim_parent,
+                                                                inode,
+                                                                victim_name,
+                                                                victim_name_len);
+                                       btrfs_run_delayed_items(trans, root);
+                               }
+                               BUG_ON(ret);
+                               iput(victim_parent);
+                               kfree(victim_name);
+                               *search_done = 1;
+                               goto again;
+                       }
+                       kfree(victim_name);
+                       BUG_ON(ret);
+next:
+                       cur_offset += victim_name_len + sizeof(*extref);
+               }
+               *search_done = 1;
+       }
+       btrfs_release_path(path);
+
        /* look for a conflicting sequence number */
        di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
-                                        btrfs_inode_ref_index(eb, ref),
-                                        name, namelen, 0);
+                                        ref_index, name, namelen, 0);
        if (di && !IS_ERR(di)) {
                ret = drop_one_dir_item(trans, root, path, dir, di);
                BUG_ON(ret);
        return 0;
 }
 
+static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
+                            u32 *namelen, char **name, u64 *index,
+                            u64 *parent_objectid)
+{
+       struct btrfs_inode_extref *extref;
+
+       extref = (struct btrfs_inode_extref *)ref_ptr;
+
+       *namelen = btrfs_inode_extref_name_len(eb, extref);
+       *name = kmalloc(*namelen, GFP_NOFS);
+       if (*name == NULL)
+               return -ENOMEM;
+
+       read_extent_buffer(eb, *name, (unsigned long)&extref->name,
+                          *namelen);
+
+       *index = btrfs_inode_extref_index(eb, extref);
+       if (parent_objectid)
+               *parent_objectid = btrfs_inode_extref_parent(eb, extref);
+
+       return 0;
+}
+
+static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
+                         u32 *namelen, char **name, u64 *index)
+{
+       struct btrfs_inode_ref *ref;
+
+       ref = (struct btrfs_inode_ref *)ref_ptr;
+
+       *namelen = btrfs_inode_ref_name_len(eb, ref);
+       *name = kmalloc(*namelen, GFP_NOFS);
+       if (*name == NULL)
+               return -ENOMEM;
+
+       read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen);
+
+       *index = btrfs_inode_ref_index(eb, ref);
+
+       return 0;
+}
+
 /*
  * replay one inode back reference item found in the log tree.
  * eb, slot and key refer to the buffer and key found in the log tree.
                                  struct extent_buffer *eb, int slot,
                                  struct btrfs_key *key)
 {
-       struct btrfs_inode_ref *ref;
        struct inode *dir;
        struct inode *inode;
        unsigned long ref_ptr;
        int namelen;
        int ret;
        int search_done = 0;
+       int log_ref_ver = 0;
+       u64 parent_objectid;
+       u64 inode_objectid;
+       u64 ref_index;
+       int ref_struct_size;
+
+       ref_ptr = btrfs_item_ptr_offset(eb, slot);
+       ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
+
+       if (key->type == BTRFS_INODE_EXTREF_KEY) {
+               struct btrfs_inode_extref *r;
+
+               ref_struct_size = sizeof(struct btrfs_inode_extref);
+               log_ref_ver = 1;
+               r = (struct btrfs_inode_extref *)ref_ptr;
+               parent_objectid = btrfs_inode_extref_parent(eb, r);
+       } else {
+               ref_struct_size = sizeof(struct btrfs_inode_ref);
+               parent_objectid = key->offset;
+       }
+       inode_objectid = key->objectid;
 
        /*
         * it is possible that we didn't log all the parent directories
         * copy the back ref in.  The link count fixup code will take
         * care of the rest
         */
-       dir = read_one_inode(root, key->offset);
+       dir = read_one_inode(root, parent_objectid);
        if (!dir)
                return -ENOENT;
 
-       inode = read_one_inode(root, key->objectid);
+       inode = read_one_inode(root, inode_objectid);
        if (!inode) {
                iput(dir);
                return -EIO;
        }
 
-       ref_ptr = btrfs_item_ptr_offset(eb, slot);
-       ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
-
        while (ref_ptr < ref_end) {
-               ref = (struct btrfs_inode_ref *)ref_ptr;
-
-               namelen = btrfs_inode_ref_name_len(eb, ref);
-               name = kmalloc(namelen, GFP_NOFS);
-               BUG_ON(!name);
-
-               read_extent_buffer(eb, name, (unsigned long)(ref + 1), namelen);
+               if (log_ref_ver) {
+                       ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
+                                               &ref_index, &parent_objectid);
+                       /*
+                        * parent object can change from one array
+                        * item to another.
+                        */
+                       if (!dir)
+                               dir = read_one_inode(root, parent_objectid);
+                       if (!dir)
+                               return -ENOENT;
+               } else {
+                       ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
+                                            &ref_index);
+               }
+               if (ret)
+                       return ret;
 
                /* if we already have a perfect match, we're done */
                if (!inode_in_dir(root, path, btrfs_ino(dir), btrfs_ino(inode),
-                                 btrfs_inode_ref_index(eb, ref),
-                                 name, namelen)) {
+                                 ref_index, name, namelen)) {
                        /*
                         * look for a conflicting back reference in the
                         * metadata. if we find one we have to unlink that name
 
                        if (!search_done) {
                                ret = __add_inode_ref(trans, root, path, log,
-                                                     dir, inode, key, eb, ref,
-                                                     name, namelen,
+                                                     dir, inode, eb,
+                                                     inode_objectid,
+                                                     parent_objectid,
+                                                     ref_index, name, namelen,
                                                      &search_done);
                                if (ret == 1)
                                        goto out;
 
                        /* insert our name */
                        ret = btrfs_add_link(trans, dir, inode, name, namelen,
-                                            0, btrfs_inode_ref_index(eb, ref));
+                                            0, ref_index);
                        BUG_ON(ret);
 
                        btrfs_update_inode(trans, root, inode);
                }
 
-               ref_ptr = (unsigned long)(ref + 1) + namelen;
+               ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen;
                kfree(name);
+               if (log_ref_ver) {
+                       iput(dir);
+                       dir = NULL;
+               }
        }
 
        /* finally write the back reference in the inode */
        return ret;
 }
 
+static int count_inode_extrefs(struct btrfs_root *root,
+                              struct inode *inode, struct btrfs_path *path)
+{
+       int ret = 0;
+       int name_len;
+       unsigned int nlink = 0;
+       u32 item_size;
+       u32 cur_offset = 0;
+       u64 inode_objectid = btrfs_ino(inode);
+       u64 offset = 0;
+       unsigned long ptr;
+       struct btrfs_inode_extref *extref;
+       struct extent_buffer *leaf;
 
-/*
- * There are a few corners where the link count of the file can't
- * be properly maintained during replay.  So, instead of adding
- * lots of complexity to the log code, we just scan the backrefs
- * for any file that has been through replay.
- *
- * The scan will update the link count on the inode to reflect the
- * number of back refs found.  If it goes down to zero, the iput
- * will free the inode.
- */
-static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
-                                          struct btrfs_root *root,
-                                          struct inode *inode)
+       while (1) {
+               ret = btrfs_find_one_extref(root, inode_objectid, offset, path,
+                                           &extref, &offset);
+               if (ret)
+                       break;
+
+               leaf = path->nodes[0];
+               item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+               ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+
+               while (cur_offset < item_size) {
+                       extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
+                       name_len = btrfs_inode_extref_name_len(leaf, extref);
+
+                       nlink++;
+
+                       cur_offset += name_len + sizeof(*extref);
+               }
+
+               offset++;
+               btrfs_release_path(path);
+       }
+       btrfs_release_path(path);
+
+       if (ret < 0)
+               return ret;
+       return nlink;
+}
+
+static int count_inode_refs(struct btrfs_root *root,
+                              struct inode *inode, struct btrfs_path *path)
 {
-       struct btrfs_path *path;
        int ret;
        struct btrfs_key key;
-       u64 nlink = 0;
+       unsigned int nlink = 0;
        unsigned long ptr;
        unsigned long ptr_end;
        int name_len;
        key.type = BTRFS_INODE_REF_KEY;
        key.offset = (u64)-1;
 
-       path = btrfs_alloc_path();
-       if (!path)
-               return -ENOMEM;
-
        while (1) {
                ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
                if (ret < 0)
                btrfs_release_path(path);
        }
        btrfs_release_path(path);
+
+       return nlink;
+}
+
+/*
+ * There are a few corners where the link count of the file can't
+ * be properly maintained during replay.  So, instead of adding
+ * lots of complexity to the log code, we just scan the backrefs
+ * for any file that has been through replay.
+ *
+ * The scan will update the link count on the inode to reflect the
+ * number of back refs found.  If it goes down to zero, the iput
+ * will free the inode.
+ */
+static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
+                                          struct btrfs_root *root,
+                                          struct inode *inode)
+{
+       struct btrfs_path *path;
+       int ret;
+       u64 nlink = 0;
+       u64 ino = btrfs_ino(inode);
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       ret = count_inode_refs(root, inode, path);
+       if (ret < 0)
+               goto out;
+
+       nlink = ret;
+
+       ret = count_inode_extrefs(root, inode, path);
+       if (ret == -ENOENT)
+               ret = 0;
+
+       if (ret < 0)
+               goto out;
+
+       nlink += ret;
+
+       ret = 0;
+
        if (nlink != inode->i_nlink) {
                set_nlink(inode, nlink);
                btrfs_update_inode(trans, root, inode);
                ret = insert_orphan_item(trans, root, ino);
                BUG_ON(ret);
        }
-       btrfs_free_path(path);
 
-       return 0;
+out:
+       btrfs_free_path(path);
+       return ret;
 }
 
 static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
                        ret = add_inode_ref(wc->trans, root, log, path,
                                            eb, i, &key);
                        BUG_ON(ret && ret != -ENOENT);
+               } else if (key.type == BTRFS_INODE_EXTREF_KEY) {
+                       ret = add_inode_ref(wc->trans, root, log, path,
+                                           eb, i, &key);
+                       BUG_ON(ret && ret != -ENOENT);
                } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
                        ret = replay_one_extent(wc->trans, root, path,
                                                eb, i, &key);