From 9ffba8cda917c0158857426f0e74b64d0206aaa9 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 14 Aug 2013 11:33:56 -0400 Subject: Btrfs: fix heavy delalloc related deadlock I added a patch where we started taking the ordered operations mutex when we waited on ordered extents. We need this because we splice the list and process it, so if a flusher came in during this scenario it would think the list was empty and we'd usually get an early ENOSPC. The problem with this is that this lock is used in transaction committing. So we end up with something like this Transaction commit -> wait on writers Delalloc flusher -> run_ordered_operations (holds mutex) ->wait for filemap-flush to do its thing flush task -> cow_file_range ->wait on btrfs_join_transaction because we're commiting some other task -> commit_transaction because we notice trans->transaction->flush is set -> run_ordered_operations (hang on mutex) We need to disentangle the ordered operations flushing from the delalloc flushing, since they are separate things. This solves the deadlock issue I was seeing. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/disk-io.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/btrfs/disk-io.c') diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 572e21eb644c..68391ecf2c59 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2277,6 +2277,7 @@ int open_ctree(struct super_block *sb, mutex_init(&fs_info->ordered_operations_mutex); + mutex_init(&fs_info->ordered_extent_flush_mutex); mutex_init(&fs_info->tree_log_mutex); mutex_init(&fs_info->chunk_mutex); mutex_init(&fs_info->transaction_kthread_mutex); -- cgit v1.2.2