NVMe: Meta-data support in NVME_IOCTL_SUBMIT_IO

This adds support for namespaces with separate meta-data formats in the
submit io ioctl. The meta-data buffer has to be a contiguous, so such
a buffer is allocated and the mapped user pages are copied to/from this
buffer for write/read commands.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 4151a3d..5a3f223 100644 (file)
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -1240,13 +1240,19 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
        struct nvme_queue *nvmeq;
        struct nvme_user_io io;
        struct nvme_command c;
-       unsigned length;
-       int status;
-       struct nvme_iod *iod;
+       unsigned length, meta_len;
+       int status, i;
+       struct nvme_iod *iod, *meta_iod = NULL;
+       dma_addr_t meta_dma_addr;
+       void *meta, *uninitialized_var(meta_mem);
 
        if (copy_from_user(&io, uio, sizeof(io)))
                return -EFAULT;
        length = (io.nblocks + 1) << ns->lba_shift;
+       meta_len = (io.nblocks + 1) * ns->ms;
+
+       if (meta_len && ((io.metadata & 3) || !io.metadata))
+               return -EINVAL;
 
        switch (io.opcode) {
        case nvme_cmd_write:
@@ -1272,7 +1278,38 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
        c.rw.reftag = cpu_to_le32(io.reftag);
        c.rw.apptag = cpu_to_le16(io.apptag);
        c.rw.appmask = cpu_to_le16(io.appmask);
-       /* XXX: metadata */
+
+       if (meta_len) {
+               meta_iod = nvme_map_user_pages(dev, io.opcode & 1, io.metadata, meta_len);
+               if (IS_ERR(meta_iod)) {
+                       status = PTR_ERR(meta_iod);
+                       meta_iod = NULL;
+                       goto unmap;
+               }
+
+               meta_mem = dma_alloc_coherent(&dev->pci_dev->dev, meta_len,
+                                               &meta_dma_addr, GFP_KERNEL);
+               if (!meta_mem) {
+                       status = -ENOMEM;
+                       goto unmap;
+               }
+
+               if (io.opcode & 1) {
+                       int meta_offset = 0;
+
+                       for (i = 0; i < meta_iod->nents; i++) {
+                               meta = kmap_atomic(sg_page(&meta_iod->sg[i])) +
+                                               meta_iod->sg[i].offset;
+                               memcpy(meta_mem + meta_offset, meta,
+                                               meta_iod->sg[i].length);
+                               kunmap_atomic(meta);
+                               meta_offset += meta_iod->sg[i].length;
+                       }
+               }
+
+               c.rw.metadata = cpu_to_le64(meta_dma_addr);
+       }
+
        length = nvme_setup_prps(dev, &c.common, iod, length, GFP_KERNEL);
 
        nvmeq = get_nvmeq(dev);
@@ -1288,8 +1325,33 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
        else
                status = nvme_submit_sync_cmd(nvmeq, &c, NULL, NVME_IO_TIMEOUT);
 
+       if (meta_len) {
+               if (status == NVME_SC_SUCCESS && !(io.opcode & 1)) {
+                       int meta_offset = 0;
+
+                       for (i = 0; i < meta_iod->nents; i++) {
+                               meta = kmap_atomic(sg_page(&meta_iod->sg[i])) +
+                                               meta_iod->sg[i].offset;
+                               memcpy(meta, meta_mem + meta_offset,
+                                               meta_iod->sg[i].length);
+                               kunmap_atomic(meta);
+                               meta_offset += meta_iod->sg[i].length;
+                       }
+               }
+
+               dma_free_coherent(&dev->pci_dev->dev, meta_len, meta_mem,
+                                                               meta_dma_addr);
+       }
+
+ unmap:
        nvme_unmap_user_pages(dev, io.opcode & 1, iod);
        nvme_free_iod(dev, iod);
+
+       if (meta_iod) {
+               nvme_unmap_user_pages(dev, io.opcode & 1, meta_iod);
+               nvme_free_iod(dev, meta_iod);
+       }
+
        return status;
 }
 
@@ -1486,6 +1548,7 @@ static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int nsid,
        ns->disk = disk;
        lbaf = id->flbas & 0xf;
        ns->lba_shift = id->lbaf[lbaf].ds;
+       ns->ms = le16_to_cpu(id->lbaf[lbaf].ms);
        blk_queue_logical_block_size(ns->queue, 1 << ns->lba_shift);
        if (dev->max_hw_sectors)
                blk_queue_max_hw_sectors(ns->queue, dev->max_hw_sectors);

diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index af29b0e..971ef08 100644 (file)
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -552,6 +552,7 @@ struct nvme_ns {
 
        int ns_id;
        int lba_shift;
+       int ms;
        u64 mode_select_num_blocks;
        u32 mode_select_block_len;
 };