Re: [PATCH] quota: propagate error from __dquot_initialize

From: Jan Kara
Date: Tue Nov 21 2017 - 08:18:45 EST


On Fri 17-11-17 10:07:53, Chao Yu wrote:
> In commit 6184fc0b8dd7 ("quota: Propagate error from ->acquire_dquot()"),
> we have propagated error from __dquot_initialize to caller, but we forgot
> to handle such error in add_dquot_ref(), so, currently, during quota
> accounting information initialization flow, if we failed for some of
> inodes, we just ignore such error, and do account for others, which is
> not a good implementation.
>
> In this patch, we choose to let user be aware of such error, so after
> turning on quota successfully, we can make sure all inodes disk usage
> can be accounted, which will be more reasonable.

Thanks for the patch! One comment below:

> @@ -2371,10 +2377,18 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
> dqopt->flags |= dquot_state_flag(flags, type);
> spin_unlock(&dq_state_lock);
>
> - add_dquot_ref(sb, type);
> + error = add_dquot_ref(sb, type);
> + if (error)
> + goto out_dquot_flags;
>
> return 0;
> -
> +out_dquot_flags:
> + spin_lock(&dq_data_lock);
> + dqopt->info[type].dqi_flags &= ~DQF_SYS_FILE;
> + spin_unlock(&dq_data_lock);
> + spin_lock(&dq_state_lock);
> + dqopt->flags &= ~(dquot_state_flag(flags, type));
> + spin_unlock(&dq_state_lock);
> out_file_init:
> dqopt->files[type] = NULL;
> iput(inode);

This bail out path is not correct. You have to go through full quota off at
this point (dquot_disable() function) as some inodes had already quotas
initialized and can be using them...

Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR