diff options
| author | Nikolay Borisov <nborisov@suse.com> | 2018-02-08 18:25:18 +0200 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2018-03-26 15:09:34 +0200 |
| commit | 45ae2c1841c31c90077cf427c09ea0e83e381026 (patch) | |
| tree | aad724668ba992f9e3128796be555a78081898c7 /fs/btrfs/extent-tree.c | |
| parent | bf6d7d4900c0d0c15dcd1baa1b65e6519bf4abef (diff) | |
btrfs: Document consistency of transaction->io_bgs list
The reason why io_bgs can be modified without holding any lock is
non-obvious. Document it and reference that documentation from the
respective call sites.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/extent-tree.c')
| -rw-r--r-- | fs/btrfs/extent-tree.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 7b4d6789cc66..9a677860f64d 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3741,8 +3741,9 @@ again: should_put = 0; /* - * the cache_write_mutex is protecting - * the io_list + * The cache_write_mutex is protecting the + * io_list, also refer to the definition of + * btrfs_transaction::io_bgs for more details */ list_add_tail(&cache->io_list, io); } else { @@ -3934,6 +3935,10 @@ int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans, } spin_unlock(&cur_trans->dirty_bgs_lock); + /* + * Refer to the definition of io_bgs member for details why it's safe + * to use it without any locking + */ while (!list_empty(io)) { cache = list_first_entry(io, struct btrfs_block_group_cache, io_list); |