[PATCH v11 2/9] block: Add copy offload support infrastructure

[Maurizio Lombardi]

po 22. 5. 2023 v 13:17 odesílatel Nitesh Shetty <nj.shetty at samsung.com> napsal:
>
> +static int __blkdev_copy_offload(struct block_device *bdev_in, loff_t pos_in,
> +               struct block_device *bdev_out, loff_t pos_out, size_t len,
> +               cio_iodone_t endio, void *private, gfp_t gfp_mask)
> +{
> +       struct cio *cio;
> +       struct copy_ctx *ctx;
> +       struct bio *read_bio, *write_bio;
> +       struct page *token;
> +       sector_t copy_len;
> +       sector_t rem, max_copy_len;
> +
> +       cio = kzalloc(sizeof(struct cio), GFP_KERNEL);
> +       if (!cio)
> +               return -ENOMEM;
> +       atomic_set(&cio->refcount, 0);
> +       cio->waiter = current;
> +       cio->endio = endio;
> +       cio->private = private;
> +
> +       max_copy_len = min(bdev_max_copy_sectors(bdev_in),
> +                       bdev_max_copy_sectors(bdev_out)) << SECTOR_SHIFT;
> +
> +       cio->pos_in = pos_in;
> +       cio->pos_out = pos_out;
> +       /* If there is a error, comp_len will be set to least successfully
> +        * completed copied length
> +        */
> +       cio->comp_len = len;
> +       for (rem = len; rem > 0; rem -= copy_len) {
> +               copy_len = min(rem, max_copy_len);
> +
> +               token = alloc_page(gfp_mask);
> +               if (unlikely(!token))
> +                       goto err_token;

[...]

> +err_token:
> +       cio->comp_len = min_t(sector_t, cio->comp_len, (len - rem));
> +       if (!atomic_read(&cio->refcount))
> +               return -ENOMEM;
> +       /* Wait for submitted IOs to complete */
> +       return blkdev_copy_wait_completion(cio);
> +}

Suppose the first call to "token = alloc_page()" fails (and
cio->refcount == 0), isn't "cio" going to be leaked here?

Maurizio