Re: [PATCH 03/18] xfs: don't treat all radix_tree_insert errors as -EEXIST

["Darrick J. Wong" <djwong@kernel.org>]

On Mon, Nov 10, 2025 at 02:22:55PM +0100, Christoph Hellwig wrote:
> Return other errors to the caller instead.  Note that there really
> shouldn't be any other errors because the entry is preallocated, but
> if there were, we'd better return them instead of retrying forever.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Good defensive strategy ;)
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
>  fs/xfs/xfs_dquot.c | 31 ++++++++++++++++++-------------
>  1 file changed, 18 insertions(+), 13 deletions(-)
> 
> diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
> index 0bd8022e47b4..79e14ee1d7a0 100644
> --- a/fs/xfs/xfs_dquot.c
> +++ b/fs/xfs/xfs_dquot.c
> @@ -860,7 +860,6 @@ xfs_qm_dqget_cache_insert(
>  	mutex_lock(&qi->qi_tree_lock);
>  	error = radix_tree_insert(tree, id, dqp);
>  	if (unlikely(error)) {
> -		/* Duplicate found!  Caller must try again. */
>  		trace_xfs_dqget_dup(dqp);
>  		goto out_unlock;
>  	}
> @@ -935,13 +934,16 @@ xfs_qm_dqget(
>  
>  	error = xfs_qm_dqget_cache_insert(mp, qi, tree, id, dqp);
>  	if (error) {
> -		/*
> -		 * Duplicate found. Just throw away the new dquot and start
> -		 * over.
> -		 */
>  		xfs_qm_dqdestroy(dqp);
> -		XFS_STATS_INC(mp, xs_qm_dquot_dups);
> -		goto restart;
> +		if (error == -EEXIST) {
> +			/*
> +			 * Duplicate found. Just throw away the new dquot and
> +			 * start over.
> +			 */
> +			XFS_STATS_INC(mp, xs_qm_dquot_dups);
> +			goto restart;
> +		}
> +		return error;
>  	}
>  
>  	trace_xfs_dqget_miss(dqp);
> @@ -1060,13 +1062,16 @@ xfs_qm_dqget_inode(
>  
>  	error = xfs_qm_dqget_cache_insert(mp, qi, tree, id, dqp);
>  	if (error) {
> -		/*
> -		 * Duplicate found. Just throw away the new dquot and start
> -		 * over.
> -		 */
>  		xfs_qm_dqdestroy(dqp);
> -		XFS_STATS_INC(mp, xs_qm_dquot_dups);
> -		goto restart;
> +		if (error == -EEXIST) {
> +			/*
> +			 * Duplicate found. Just throw away the new dquot and
> +			 * start over.
> +			 */
> +			XFS_STATS_INC(mp, xs_qm_dquot_dups);
> +			goto restart;
> +		}
> +		return error;
>  	}
>  
>  dqret:
> -- 
> 2.47.3
> 
>