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Diffstat (limited to 'fs/btrfs/qgroup.c')
-rw-r--r--fs/btrfs/qgroup.c32
1 files changed, 29 insertions, 3 deletions
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 2f708f2c4e67..f8a3c1b0a15a 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2614,6 +2614,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
int ret = 0;
int i;
u64 *i_qgroups;
+ bool committing = false;
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *quota_root;
struct btrfs_qgroup *srcgroup;
@@ -2621,7 +2622,25 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
u32 level_size = 0;
u64 nums;
- mutex_lock(&fs_info->qgroup_ioctl_lock);
+ /*
+ * There are only two callers of this function.
+ *
+ * One in create_subvol() in the ioctl context, which needs to hold
+ * the qgroup_ioctl_lock.
+ *
+ * The other one in create_pending_snapshot() where no other qgroup
+ * code can modify the fs as they all need to either start a new trans
+ * or hold a trans handler, thus we don't need to hold
+ * qgroup_ioctl_lock.
+ * This would avoid long and complex lock chain and make lockdep happy.
+ */
+ spin_lock(&fs_info->trans_lock);
+ if (trans->transaction->state == TRANS_STATE_COMMIT_DOING)
+ committing = true;
+ spin_unlock(&fs_info->trans_lock);
+
+ if (!committing)
+ mutex_lock(&fs_info->qgroup_ioctl_lock);
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
goto out;
@@ -2785,7 +2804,8 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
unlock:
spin_unlock(&fs_info->qgroup_lock);
out:
- mutex_unlock(&fs_info->qgroup_ioctl_lock);
+ if (!committing)
+ mutex_unlock(&fs_info->qgroup_ioctl_lock);
return ret;
}
@@ -3830,7 +3850,13 @@ int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans,
subvol_slot);
block->last_snapshot = last_snapshot;
block->level = level;
- if (bg->flags & BTRFS_BLOCK_GROUP_DATA)
+
+ /*
+ * If we have bg == NULL, we're called from btrfs_recover_relocation(),
+ * no one else can modify tree blocks thus we qgroup will not change
+ * no matter the value of trace_leaf.
+ */
+ if (bg && bg->flags & BTRFS_BLOCK_GROUP_DATA)
block->trace_leaf = true;
else
block->trace_leaf = false;