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| author | Sage Weil <sage@inktank.com> | 2012-08-30 16:26:15 -0600 |
|---|---|---|
| committer | Chris Mason <chris.mason@fusionio.com> | 2012-10-01 15:19:07 -0400 |
| commit | 6fc4e3548598d10a5e947797a09cbc1b257a22ab (patch) | |
| tree | ad7e5727ef08cebffa0bc1c36af05c363f851218 /fs/btrfs/transaction.c | |
| parent | 2aaa66558172b017f36bf38ae69372813dedee9d (diff) | |
| download | lwn-6fc4e3548598d10a5e947797a09cbc1b257a22ab.tar.gz lwn-6fc4e3548598d10a5e947797a09cbc1b257a22ab.zip | |
Btrfs: pass lockdep rwsem metadata to async commit transaction
The freeze rwsem is taken by sb_start_intwrite() and dropped during the
commit_ or end_transaction(). In the async case, that happens in a worker
thread. Tell lockdep the calling thread is releasing ownership of the
rwsem and the async thread is picking it up.
XFS plays the same trick in fs/xfs/xfs_aops.c.
Signed-off-by: Sage Weil <sage@inktank.com>
Diffstat (limited to 'fs/btrfs/transaction.c')
| -rw-r--r-- | fs/btrfs/transaction.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 27c26004e050..730c94590c9f 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1229,6 +1229,14 @@ static void do_async_commit(struct work_struct *work) struct btrfs_async_commit *ac = container_of(work, struct btrfs_async_commit, work.work); + /* + * We've got freeze protection passed with the transaction. + * Tell lockdep about it. + */ + rwsem_acquire_read( + &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1], + 0, 1, _THIS_IP_); + btrfs_commit_transaction(ac->newtrans, ac->root); kfree(ac); } @@ -1258,6 +1266,14 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans, atomic_inc(&cur_trans->use_count); btrfs_end_transaction(trans, root); + + /* + * Tell lockdep we've released the freeze rwsem, since the + * async commit thread will be the one to unlock it. + */ + rwsem_release(&root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1], + 1, _THIS_IP_); + schedule_delayed_work(&ac->work, 0); /* wait for transaction to start and unblock */ |