On Wed, Aug 29, 2018 at 12:10 PM Javier González <javier@xxxxxxxxxxx> wrote:
>
> The lightnvm subsystem provides helpers to retrieve chunk metadata,
> where the target needs to provide a buffer to store the metadata. An
> implicit assumption is that this buffer is contiguous and can be used to
> retrieve the data from the device. If the device exposes too many
> chunks, then kmalloc might fail, thus failing instance creation.
>
> This patch removes this assumption by implementing an internal buffer in
> the lightnvm subsystem to retrieve chunk metadata. Targets can then
> use virtual memory allocations. Since this is a target API change, adapt
> pblk accordingly.
>
> Signed-off-by: Javier González <javier@xxxxxxxxxxxx>
> ---
> drivers/lightnvm/pblk-core.c | 4 ++--
> drivers/lightnvm/pblk-init.c | 2 +-
> drivers/nvme/host/lightnvm.c | 23 +++++++++++++++--------
> 3 files changed, 18 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
> index fdcbeb920c9e..a311cc29afd8 100644
> --- a/drivers/lightnvm/pblk-core.c
> +++ b/drivers/lightnvm/pblk-core.c
> @@ -120,7 +120,7 @@ static void pblk_end_io_erase(struct nvm_rq *rqd)
> /*
> * Get information for all chunks from the device.
> *
> - * The caller is responsible for freeing the returned structure
> + * The caller is responsible for freeing (vmalloc) the returned structure
> */
> struct nvm_chk_meta *pblk_get_chunk_meta(struct pblk *pblk)
> {
> @@ -134,7 +134,7 @@ struct nvm_chk_meta *pblk_get_chunk_meta(struct pblk *pblk)
> ppa.ppa = 0;
>
> len = geo->all_chunks * sizeof(*meta);
> - meta = kzalloc(len, GFP_KERNEL);
> + meta = vzalloc(len);
> if (!meta)
> return ERR_PTR(-ENOMEM);
>
> diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
> index e0db6de137d6..a99854439224 100644
> --- a/drivers/lightnvm/pblk-init.c
> +++ b/drivers/lightnvm/pblk-init.c
> @@ -983,7 +983,7 @@ static int pblk_lines_init(struct pblk *pblk)
>
> pblk_set_provision(pblk, nr_free_chks);
>
> - kfree(chunk_meta);
> + vfree(chunk_meta);
> return 0;
>
> fail_free_lines:
> diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
> index 2c96e7fcdcac..5bfa354c5dd5 100644
> --- a/drivers/nvme/host/lightnvm.c
> +++ b/drivers/nvme/host/lightnvm.c
> @@ -579,7 +579,7 @@ static int nvme_nvm_get_chk_meta(struct nvm_dev *ndev,
> struct nvm_geo *geo = &ndev->geo;
> struct nvme_ns *ns = ndev->q->queuedata;
> struct nvme_ctrl *ctrl = ns->ctrl;
> - struct nvme_nvm_chk_meta *dev_meta = (struct nvme_nvm_chk_meta *)meta;
> + struct nvme_nvm_chk_meta *dev_meta, *dev_meta_off;
> struct ppa_addr ppa;
> size_t left = nchks * sizeof(struct nvme_nvm_chk_meta);
> size_t log_pos, offset, len;
> @@ -591,6 +591,10 @@ static int nvme_nvm_get_chk_meta(struct nvm_dev *ndev,
> */
> max_len = min_t(unsigned int, ctrl->max_hw_sectors << 9, 256 * 1024);
>
> + dev_meta = kmalloc(max_len, GFP_KERNEL);
> + if (!dev_meta)
> + return -ENOMEM;
We should free the memory after using it. Pardon the late review, I
just now discovered the memory leak during testing.
> +
> /* Normalize lba address space to obtain log offset */
> ppa.ppa = slba;
> ppa = dev_to_generic_addr(ndev, ppa);
> @@ -604,6 +608,9 @@ static int nvme_nvm_get_chk_meta(struct nvm_dev *ndev,
> while (left) {
> len = min_t(unsigned int, left, max_len);
>
> + memset(dev_meta, 0, max_len);
> + dev_meta_off = dev_meta;
> +
> ret = nvme_get_log_ext(ctrl, ns, NVME_NVM_LOG_REPORT_CHUNK,
> dev_meta, len, offset);
> if (ret) {
> @@ -612,15 +619,15 @@ static int nvme_nvm_get_chk_meta(struct nvm_dev *ndev,
> }
>
> for (i = 0; i < len; i += sizeof(struct nvme_nvm_chk_meta)) {
> - meta->state = dev_meta->state;
> - meta->type = dev_meta->type;
> - meta->wi = dev_meta->wi;
> - meta->slba = le64_to_cpu(dev_meta->slba);
> - meta->cnlb = le64_to_cpu(dev_meta->cnlb);
> - meta->wp = le64_to_cpu(dev_meta->wp);
> + meta->state = dev_meta_off->state;
> + meta->type = dev_meta_off->type;
> + meta->wi = dev_meta_off->wi;
> + meta->slba = le64_to_cpu(dev_meta_off->slba);
> + meta->cnlb = le64_to_cpu(dev_meta_off->cnlb);
> + meta->wp = le64_to_cpu(dev_meta_off->wp);
>
> meta++;
> - dev_meta++;
> + dev_meta_off++;
> }
>
> offset += len;
> --
> 2.7.4
>
