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author | Arne Jansen <sensille@gmx.net> | 2012-08-06 14:18:51 -0600 |
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committer | Chris Mason <chris.mason@oracle.com> | 2012-08-28 16:53:32 -0400 |
commit | 1fa11e265fa2562fb713171b6a58e72bb7afd276 (patch) | |
tree | 9b8e80ef9ef0479d270d46b46c4ca7d0106d3ae0 /fs/btrfs/ctree.h | |
parent | 6209526531e70c080f79318ab8f50e26846c40a8 (diff) | |
download | op-kernel-dev-1fa11e265fa2562fb713171b6a58e72bb7afd276.zip op-kernel-dev-1fa11e265fa2562fb713171b6a58e72bb7afd276.tar.gz |
Btrfs: fix deadlock in wait_for_more_refs
Commit a168650c introduced a waiting mechanism to prevent busy waiting in
btrfs_run_delayed_refs. This can deadlock with btrfs_run_ordered_operations,
where a tree_mod_seq is held while waiting for the io to complete, while
the end_io calls btrfs_run_delayed_refs.
This whole mechanism is unnecessary. If not enough runnable refs are
available to satisfy count, just return as count is more like a guideline
than a strict requirement.
In case we have to run all refs, commit transaction makes sure that no
other threads are working in the transaction anymore, so we just assert
here that no refs are blocked.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Diffstat (limited to 'fs/btrfs/ctree.h')
-rw-r--r-- | fs/btrfs/ctree.h | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 3481963..c38734a 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1252,7 +1252,6 @@ struct btrfs_fs_info { atomic_t tree_mod_seq; struct list_head tree_mod_seq_list; struct seq_list tree_mod_seq_elem; - wait_queue_head_t tree_mod_seq_wait; /* this protects tree_mod_log */ rwlock_t tree_mod_log_lock; |