Btrfs: adjust the write_lock_level as we unlock

[sagit-ice-cold/kernel_xiaomi_msm8998.git] / fs / btrfs / ctree.c

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 8af24da..270655d 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1395,7 +1395,8 @@ static noinline int reada_for_balance(struct btrfs_root *root,
  * if lowest_unlock is 1, level 0 won't be unlocked
  */
 static noinline void unlock_up(struct btrfs_path *path, int level,
-                              int lowest_unlock)
+                              int lowest_unlock, int min_write_lock_level,
+                              int *write_lock_level)
 {
        int i;
        int skip_level = level;
@@ -1427,6 +1428,11 @@ static noinline void unlock_up(struct btrfs_path *path, int level,
                if (i >= lowest_unlock && i > skip_level && path->locks[i]) {
                        btrfs_tree_unlock_rw(t, path->locks[i]);
                        path->locks[i] = 0;
+                       if (write_lock_level &&
+                           i > min_write_lock_level &&
+                           i <= *write_lock_level) {
+                               *write_lock_level = i - 1;
+                       }
                }
        }
 }
@@ -1650,6 +1656,7 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
        /* everything at write_lock_level or lower must be write locked */
        int write_lock_level = 0;
        u8 lowest_level = 0;
+       int min_write_lock_level;
 
        lowest_level = p->lowest_level;
        WARN_ON(lowest_level && ins_len > 0);
@@ -1677,6 +1684,8 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
        if (cow && (p->keep_locks || p->lowest_level))
                write_lock_level = BTRFS_MAX_LEVEL;
 
+       min_write_lock_level = write_lock_level;
+
 again:
        /*
         * we try very hard to do read locks on the root
@@ -1808,7 +1817,8 @@ cow_done:
                                goto again;
                        }
 
-                       unlock_up(p, level, lowest_unlock);
+                       unlock_up(p, level, lowest_unlock,
+                                 min_write_lock_level, &write_lock_level);
 
                        if (level == lowest_level) {
                                if (dec)
@@ -1870,7 +1880,8 @@ cow_done:
                                }
                        }
                        if (!p->search_for_split)
-                               unlock_up(p, level, lowest_unlock);
+                               unlock_up(p, level, lowest_unlock,
+                                         min_write_lock_level, &write_lock_level);
                        goto done;
                }
        }
@@ -4108,7 +4119,7 @@ find_next_key:
                path->slots[level] = slot;
                if (level == path->lowest_level) {
                        ret = 0;
-                       unlock_up(path, level, 1);
+                       unlock_up(path, level, 1, 0, NULL);
                        goto out;
                }
                btrfs_set_path_blocking(path);
@@ -4119,7 +4130,7 @@ find_next_key:
 
                path->locks[level - 1] = BTRFS_READ_LOCK;
                path->nodes[level - 1] = cur;
-               unlock_up(path, level, 1);
+               unlock_up(path, level, 1, 0, NULL);
                btrfs_clear_path_blocking(path, NULL, 0);
        }
 out:
@@ -4355,7 +4366,7 @@ again:
        }
        ret = 0;
 done:
-       unlock_up(path, 0, 1);
+       unlock_up(path, 0, 1, 0, NULL);
        path->leave_spinning = old_spinning;
        if (!old_spinning)
                btrfs_set_path_blocking(path);