diff mbox series

[v4,3/7] btrfs: Add a lockdep annotation for the num_extwriters wait event

Message ID 20220725221150.3959022-4-iangelak@fb.com (mailing list archive)
State New, archived
Headers show
Series btrfs: Annotate wait events with lockdep | expand

Commit Message

Ioannis Angelakopoulos July 25, 2022, 10:11 p.m. UTC 
Similarly to the num_writers wait event in fs/btrfs/transaction.c add a
lockdep annotation for the num_extwriters wait event.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Ioannis Angelakopoulos <iangelak@fb.com>
---
 fs/btrfs/ctree.h       |  1 +
 fs/btrfs/disk-io.c     |  1 +
 fs/btrfs/transaction.c | 13 +++++++++++++
 3 files changed, 15 insertions(+)
diff mbox series

Patch

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0825d30a4273..883e6e725b8f 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1096,6 +1096,7 @@  struct btrfs_fs_info {
 	struct btrfs_commit_stats commit_stats;
 
 	struct lockdep_map btrfs_trans_num_writers_map;
+	struct lockdep_map btrfs_trans_num_extwriters_map;
 
 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 	spinlock_t ref_verify_lock;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 38831c730d61..43330a92e7ae 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3075,6 +3075,7 @@  void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
 	seqlock_init(&fs_info->profiles_lock);
 
 	btrfs_lockdep_init_map(fs_info, btrfs_trans_num_writers);
+	btrfs_lockdep_init_map(fs_info, btrfs_trans_num_extwriters);
 
 	INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
 	INIT_LIST_HEAD(&fs_info->space_info);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index d8287ec890bc..c9751a05c029 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -314,6 +314,7 @@  static noinline int join_transaction(struct btrfs_fs_info *fs_info,
 		extwriter_counter_inc(cur_trans, type);
 		spin_unlock(&fs_info->trans_lock);
 		btrfs_lockdep_acquire(fs_info, btrfs_trans_num_writers);
+		btrfs_lockdep_acquire(fs_info, btrfs_trans_num_extwriters);
 		return 0;
 	}
 	spin_unlock(&fs_info->trans_lock);
@@ -336,6 +337,7 @@  static noinline int join_transaction(struct btrfs_fs_info *fs_info,
 		return -ENOMEM;
 
 	btrfs_lockdep_acquire(fs_info, btrfs_trans_num_writers);
+	btrfs_lockdep_acquire(fs_info, btrfs_trans_num_extwriters);
 
 	spin_lock(&fs_info->trans_lock);
 	if (fs_info->running_transaction) {
@@ -343,11 +345,13 @@  static noinline int join_transaction(struct btrfs_fs_info *fs_info,
 		 * someone started a transaction after we unlocked.  Make sure
 		 * to redo the checks above
 		 */
+		btrfs_lockdep_release(fs_info, btrfs_trans_num_extwriters);
 		btrfs_lockdep_release(fs_info, btrfs_trans_num_writers);
 		kfree(cur_trans);
 		goto loop;
 	} else if (BTRFS_FS_ERROR(fs_info)) {
 		spin_unlock(&fs_info->trans_lock);
+		btrfs_lockdep_release(fs_info, btrfs_trans_num_extwriters);
 		btrfs_lockdep_release(fs_info, btrfs_trans_num_writers);
 		kfree(cur_trans);
 		return -EROFS;
@@ -1028,6 +1032,7 @@  static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
 
 	cond_wake_up(&cur_trans->writer_wait);
 
+	btrfs_lockdep_release(info, btrfs_trans_num_extwriters);
 	btrfs_lockdep_release(info, btrfs_trans_num_writers);
 
 	btrfs_put_transaction(cur_trans);
@@ -2270,6 +2275,13 @@  int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
 	if (ret)
 		goto lockdep_release;
 
+	/*
+	 * The thread has started/joined the transaction thus it holds the lockdep
+	 * map as a reader. It has to release it before acquiring the lockdep map
+	 * as a writer.
+	 */
+	btrfs_lockdep_release(fs_info, btrfs_trans_num_extwriters);
+	btrfs_might_wait_for_event(fs_info, btrfs_trans_num_extwriters);
 	wait_event(cur_trans->writer_wait,
 		   extwriter_counter_read(cur_trans) == 0);
 
@@ -2540,6 +2552,7 @@  int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
 
 	return ret;
 lockdep_release:
+	btrfs_lockdep_release(fs_info, btrfs_trans_num_extwriters);
 	btrfs_lockdep_release(fs_info, btrfs_trans_num_writers);
 	goto cleanup_transaction;
 }