diff options
Diffstat (limited to 'fs/btrfs/file.c')
| -rw-r--r-- | fs/btrfs/file.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 030012e..72df63b 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1928,12 +1928,24 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) if (file->private_data) btrfs_ioctl_trans_end(file); + /* + * We use start here because we will need to wait on the IO to complete + * in btrfs_sync_log, which could require joining a transaction (for + * example checking cross references in the nocow path). If we use join + * here we could get into a situation where we're waiting on IO to + * happen that is blocked on a transaction trying to commit. With start + * we inc the extwriter counter, so we wait for all extwriters to exit + * before we start blocking join'ers. This comment is to keep somebody + * from thinking they are super smart and changing this to + * btrfs_join_transaction *cough*Josef*cough*. + */ trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) { ret = PTR_ERR(trans); mutex_unlock(&inode->i_mutex); goto out; } + trans->sync = true; ret = btrfs_log_dentry_safe(trans, root, dentry); if (ret < 0) { |