btrfs: qgroup: Avoid calling btrfs_free_reserved_data_space in clear_bit_hook

In clear_bit_hook, qgroup reserved data is already handled quite well,
either released by finish_ordered_io or invalidatepage.

So calling btrfs_qgroup_free_data() here is completely meaningless, and
since btrfs_qgroup_free_data() will lock io_tree, so it can't be called
with io_tree lock hold.

This patch will add a new function
btrfs_free_reserved_data_space_noquota() for clear_bit_hook() to cease
the lockdep warning.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

1 files changed, 18 insertions, 10 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index aaaa7746685a..46609607789b 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4066,10 +4066,12 @@ int btrfs_check_data_free_space(struct inode *inode, u64 start, u64 len)
  * Called if we need to clear a data reservation for this inode
  * Normally in a error case.
  *
- * This one will handle the per-indoe data rsv map for accurate reserved
- * space framework.
+ * This one will *NOT* use accurate qgroup reserved space API, just for case
+ * which we can't sleep and is sure it won't affect qgroup reserved space.
+ * Like clear_bit_hook().
  */
-void btrfs_free_reserved_data_space(struct inode *inode, u64 start, u64 len)
+void btrfs_free_reserved_data_space_noquota(struct inode *inode, u64 start,
+					    u64 len)
 {
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_space_info *data_sinfo;
@@ -4079,13 +4081,6 @@ void btrfs_free_reserved_data_space(struct inode *inode, u64 start, u64 len)
 	      round_down(start, root->sectorsize);
 	start = round_down(start, root->sectorsize);
 
-	/*
-	 * Free any reserved qgroup data space first
-	 * As it will alloc memory, we can't do it with data sinfo
-	 * spinlock hold.
-	 */
-	btrfs_qgroup_free_data(inode, start, len);
-
 	data_sinfo = root->fs_info->data_sinfo;
 	spin_lock(&data_sinfo->lock);
 	if (WARN_ON(data_sinfo->bytes_may_use < len))
@@ -4097,6 +4092,19 @@ void btrfs_free_reserved_data_space(struct inode *inode, u64 start, u64 len)
 	spin_unlock(&data_sinfo->lock);
 }
 
+/*
+ * Called if we need to clear a data reservation for this inode
+ * Normally in a error case.
+ *
+ * This one will handle the per-indoe data rsv map for accurate reserved
+ * space framework.
+ */
+void btrfs_free_reserved_data_space(struct inode *inode, u64 start, u64 len)
+{
+	btrfs_free_reserved_data_space_noquota(inode, start, len);
+	btrfs_qgroup_free_data(inode, start, len);
+}
+
 static void force_metadata_allocation(struct btrfs_fs_info *info)
 {
 	struct list_head *head = &info->space_info;