Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull second set of btrfs updates from Chris Mason:
 "The most important changes here are from Josef, fixing a btrfs
  regression in 3.14 that can cause corruptions in the extent allocation
  tree when snapshots are in use.

  Josef also fixed some deadlocks in send/recv and other assorted races
  when balance is running"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (23 commits)
  Btrfs: fix compile warnings on on avr32 platform
  btrfs: allow mounting btrfs subvolumes with different ro/rw options
  btrfs: export global block reserve size as space_info
  btrfs: fix crash in remount(thread_pool=) case
  Btrfs: abort the transaction when we don't find our extent ref
  Btrfs: fix EINVAL checks in btrfs_clone
  Btrfs: fix unlock in __start_delalloc_inodes()
  Btrfs: scrub raid56 stripes in the right way
  Btrfs: don't compress for a small write
  Btrfs: more efficient io tree navigation on wait_extent_bit
  Btrfs: send, build path string only once in send_hole
  btrfs: filter invalid arg for btrfs resize
  Btrfs: send, fix data corruption due to incorrect hole detection
  Btrfs: kmalloc() doesn't return an ERR_PTR
  Btrfs: fix snapshot vs nocow writting
  btrfs: Change the expanding write sequence to fix snapshot related bug.
  btrfs: make device scan less noisy
  btrfs: fix lockdep warning with reclaim lock inversion
  Btrfs: hold the commit_root_sem when getting the commit root during send
  Btrfs: remove transaction from send
  ...

1 files changed, 27 insertions, 6 deletions

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index aad7201ad11b..10db21fa0926 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -330,7 +330,10 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
                 goto out;
         }
 
-        root_level = btrfs_old_root_level(root, time_seq);
+        if (path->search_commit_root)
+                root_level = btrfs_header_level(root->commit_root);
+        else
+                root_level = btrfs_old_root_level(root, time_seq);
 
         if (root_level + 1 == level) {
                 srcu_read_unlock(&fs_info->subvol_srcu, index);
@@ -1099,9 +1102,9 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
  *
  * returns 0 on success, < 0 on error.
  */
-int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
-                                struct btrfs_fs_info *fs_info, u64 bytenr,
-                                u64 time_seq, struct ulist **roots)
+static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans,
+                                  struct btrfs_fs_info *fs_info, u64 bytenr,
+                                  u64 time_seq, struct ulist **roots)
 {
         struct ulist *tmp;
         struct ulist_node *node = NULL;
@@ -1137,6 +1140,20 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
         return 0;
 }
 
+int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
+                         struct btrfs_fs_info *fs_info, u64 bytenr,
+                         u64 time_seq, struct ulist **roots)
+{
+        int ret;
+
+        if (!trans)
+                down_read(&fs_info->commit_root_sem);
+        ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots);
+        if (!trans)
+                up_read(&fs_info->commit_root_sem);
+        return ret;
+}
+
 /*
  * this makes the path point to (inum INODE_ITEM ioff)
  */
@@ -1516,6 +1533,8 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
                 if (IS_ERR(trans))
                         return PTR_ERR(trans);
                 btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
+        } else {
+                down_read(&fs_info->commit_root_sem);
         }
 
         ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid,
@@ -1526,8 +1545,8 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
 
         ULIST_ITER_INIT(&ref_uiter);
         while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) {
-                ret = btrfs_find_all_roots(trans, fs_info, ref_node->val,
-                                           tree_mod_seq_elem.seq, &roots);
+                ret = __btrfs_find_all_roots(trans, fs_info, ref_node->val,
+                                             tree_mod_seq_elem.seq, &roots);
                 if (ret)
                         break;
                 ULIST_ITER_INIT(&root_uiter);
@@ -1549,6 +1568,8 @@ out:
         if (!search_commit_root) {
                 btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
                 btrfs_end_transaction(trans, fs_info->extent_root);
+        } else {
+                up_read(&fs_info->commit_root_sem);
         }
 
         return ret;