1 files changed, 68 insertions, 0 deletions

diff --git a/fs/nfs/objlayout/objlayout.c b/fs/nfs/objlayout/objlayout.c
index 946526763d38..10e5fca3b7fb 100644
--- a/fs/nfs/objlayout/objlayout.c
+++ b/fs/nfs/objlayout/objlayout.c
@@ -102,3 +102,71 @@ objlayout_free_lseg(struct pnfs_layout_segment *lseg)
         objio_free_lseg(lseg);
 }
 
+/*
+ * Get Device Info API for io engines
+ */
+struct objlayout_deviceinfo {
+        struct page *page;
+        struct pnfs_osd_deviceaddr da; /* This must be last */
+};
+
+/* Initialize and call nfs_getdeviceinfo, then decode and return a
+ * "struct pnfs_osd_deviceaddr *" Eventually objlayout_put_deviceinfo()
+ * should be called.
+ */
+int objlayout_get_deviceinfo(struct pnfs_layout_hdr *pnfslay,
+        struct nfs4_deviceid *d_id, struct pnfs_osd_deviceaddr **deviceaddr,
+        gfp_t gfp_flags)
+{
+        struct objlayout_deviceinfo *odi;
+        struct pnfs_device pd;
+        struct super_block *sb;
+        struct page *page, **pages;
+        u32 *p;
+        int err;
+
+        page = alloc_page(gfp_flags);
+        if (!page)
+                return -ENOMEM;
+
+        pages = &page;
+        pd.pages = pages;
+
+        memcpy(&pd.dev_id, d_id, sizeof(*d_id));
+        pd.layout_type = LAYOUT_OSD2_OBJECTS;
+        pd.pages = &page;
+        pd.pgbase = 0;
+        pd.pglen = PAGE_SIZE;
+        pd.mincount = 0;
+
+        sb = pnfslay->plh_inode->i_sb;
+        err = nfs4_proc_getdeviceinfo(NFS_SERVER(pnfslay->plh_inode), &pd);
+        dprintk("%s nfs_getdeviceinfo returned %d\n", __func__, err);
+        if (err)
+                goto err_out;
+
+        p = page_address(page);
+        odi = kzalloc(sizeof(*odi), gfp_flags);
+        if (!odi) {
+                err = -ENOMEM;
+                goto err_out;
+        }
+        pnfs_osd_xdr_decode_deviceaddr(&odi->da, p);
+        odi->page = page;
+        *deviceaddr = &odi->da;
+        return 0;
+
+err_out:
+        __free_page(page);
+        return err;
+}
+
+void objlayout_put_deviceinfo(struct pnfs_osd_deviceaddr *deviceaddr)
+{
+        struct objlayout_deviceinfo *odi = container_of(deviceaddr,
+                                                struct objlayout_deviceinfo,
+                                                da);
+
+        __free_page(odi->page);
+        kfree(odi);
+}