pnfs: factor GETDEVICEINFO implementations

Add support to the common pNFS core to issue GETDEVICEINFO calls on
a device ID cache miss.  The code is taken from the well debugged
file layout implementation and calls out to the layoutdriver through
a new alloc_deviceid_node method.  The calling conventions for
nfs4_find_get_deviceid are changed so that all information needed to
send a GETDEVICEINFO request is passed to the common code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

8 files changed, 182 insertions, 312 deletions

diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c
index 163cad1d412..abc5056999d 100644
--- a/fs/nfs/filelayout/filelayout.c
+++ b/fs/nfs/filelayout/filelayout.c
@@ -649,18 +649,15 @@ filelayout_check_layout(struct pnfs_layout_hdr *lo,
 	}
 
 	/* find and reference the deviceid */
-	d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode)->pnfs_curr_ld,
-				   NFS_SERVER(lo->plh_inode)->nfs_client, id);
-	if (d == NULL) {
-		dsaddr = filelayout_get_device_info(lo->plh_inode, id,
-				lo->plh_lc_cred, gfp_flags);
-		if (dsaddr == NULL)
-			goto out;
-	} else
-		dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
+	d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), id,
+			lo->plh_lc_cred, gfp_flags);
+	if (d == NULL)
+		goto out;
+
+	dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
 	/* Found deviceid is unavailable */
 	if (filelayout_test_devid_unavailable(&dsaddr->id_node))
-			goto out_put;
+		goto out_put;
 
 	fl->dsaddr = dsaddr;
 
@@ -1371,6 +1368,17 @@ out:
 	cinfo->ds->ncommitting = 0;
 	return PNFS_ATTEMPTED;
 }
+static struct nfs4_deviceid_node *
+filelayout_alloc_deviceid_node(struct nfs_server *server,
+		struct pnfs_device *pdev, gfp_t gfp_flags)
+{
+	struct nfs4_file_layout_dsaddr *dsaddr;
+
+	dsaddr = nfs4_fl_alloc_deviceid_node(server, pdev, gfp_flags);
+	if (!dsaddr)
+		return NULL;
+	return &dsaddr->id_node;
+}
 
 static void
 filelayout_free_deveiceid_node(struct nfs4_deviceid_node *d)
@@ -1423,6 +1431,7 @@ static struct pnfs_layoutdriver_type filelayout_type = {
 	.commit_pagelist	= filelayout_commit_pagelist,
 	.read_pagelist		= filelayout_read_pagelist,
 	.write_pagelist		= filelayout_write_pagelist,
+	.alloc_deviceid_node	= filelayout_alloc_deviceid_node,
 	.free_deviceid_node	= filelayout_free_deveiceid_node,
 };
 
diff --git a/fs/nfs/filelayout/filelayout.h b/fs/nfs/filelayout/filelayout.h
index ffbddf2219e..7c9f800c49d 100644
--- a/fs/nfs/filelayout/filelayout.h
+++ b/fs/nfs/filelayout/filelayout.h
@@ -147,10 +147,11 @@ u32 nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset);
 u32 nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j);
 struct nfs4_pnfs_ds *nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg,
 					u32 ds_idx);
+
+extern struct nfs4_file_layout_dsaddr *
+nfs4_fl_alloc_deviceid_node(struct nfs_server *server,
+	struct pnfs_device *pdev, gfp_t gfp_flags);
 extern void nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
 extern void nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
-struct nfs4_file_layout_dsaddr *
-filelayout_get_device_info(struct inode *inode, struct nfs4_deviceid *dev_id,
-		struct rpc_cred *cred, gfp_t gfp_flags);
 
 #endif /* FS_NFS_NFS4FILELAYOUT_H */
diff --git a/fs/nfs/filelayout/filelayoutdev.c b/fs/nfs/filelayout/filelayoutdev.c
index 8540516f4d7..9bb806a76d9 100644
--- a/fs/nfs/filelayout/filelayoutdev.c
+++ b/fs/nfs/filelayout/filelayoutdev.c
@@ -484,8 +484,9 @@ out_err:
 }
 
 /* Decode opaque device data and return the result */
-static struct nfs4_file_layout_dsaddr*
-decode_device(struct inode *ino, struct pnfs_device *pdev, gfp_t gfp_flags)
+struct nfs4_file_layout_dsaddr *
+nfs4_fl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
+		gfp_t gfp_flags)
 {
 	int i;
 	u32 cnt, num;
@@ -570,10 +571,7 @@ decode_device(struct inode *ino, struct pnfs_device *pdev, gfp_t gfp_flags)
 	dsaddr->stripe_indices = stripe_indices;
 	stripe_indices = NULL;
 	dsaddr->ds_num = num;
-	nfs4_init_deviceid_node(&dsaddr->id_node,
-				NFS_SERVER(ino)->pnfs_curr_ld,
-				NFS_SERVER(ino)->nfs_client,
-				&pdev->dev_id);
+	nfs4_init_deviceid_node(&dsaddr->id_node, server, &pdev->dev_id);
 
 	INIT_LIST_HEAD(&dsaddrs);
 
@@ -587,7 +585,7 @@ decode_device(struct inode *ino, struct pnfs_device *pdev, gfp_t gfp_flags)
 
 		mp_count = be32_to_cpup(p); /* multipath count */
 		for (j = 0; j < mp_count; j++) {
-			da = decode_ds_addr(NFS_SERVER(ino)->nfs_client->cl_net,
+			da = decode_ds_addr(server->nfs_client->cl_net,
 					    &stream, gfp_flags);
 			if (da)
 				list_add_tail(&da->da_node, &dsaddrs);
@@ -637,102 +635,6 @@ out_err:
 	return NULL;
 }
 
-/*
- * Decode the opaque device specified in 'dev' and add it to the cache of
- * available devices.
- */
-static struct nfs4_file_layout_dsaddr *
-decode_and_add_device(struct inode *inode, struct pnfs_device *dev, gfp_t gfp_flags)
-{
-	struct nfs4_deviceid_node *d;
-	struct nfs4_file_layout_dsaddr *n, *new;
-
-	new = decode_device(inode, dev, gfp_flags);
-	if (!new) {
-		printk(KERN_WARNING "NFS: %s: Could not decode or add device\n",
-			__func__);
-		return NULL;
-	}
-
-	d = nfs4_insert_deviceid_node(&new->id_node);
-	n = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
-	if (n != new) {
-		nfs4_fl_free_deviceid(new);
-		return n;
-	}
-
-	return new;
-}
-
-/*
- * Retrieve the information for dev_id, add it to the list
- * of available devices, and return it.
- */
-struct nfs4_file_layout_dsaddr *
-filelayout_get_device_info(struct inode *inode,
-		struct nfs4_deviceid *dev_id,
-		struct rpc_cred *cred,
-		gfp_t gfp_flags)
-{
-	struct pnfs_device *pdev = NULL;
-	u32 max_resp_sz;
-	int max_pages;
-	struct page **pages = NULL;
-	struct nfs4_file_layout_dsaddr *dsaddr = NULL;
-	int rc, i;
-	struct nfs_server *server = NFS_SERVER(inode);
-
-	/*
-	 * Use the session max response size as the basis for setting
-	 * GETDEVICEINFO's maxcount
-	 */
-	max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
-	max_pages = nfs_page_array_len(0, max_resp_sz);
-	dprintk("%s inode %p max_resp_sz %u max_pages %d\n",
-		__func__, inode, max_resp_sz, max_pages);
-
-	pdev = kzalloc(sizeof(struct pnfs_device), gfp_flags);
-	if (pdev == NULL)
-		return NULL;
-
-	pages = kcalloc(max_pages, sizeof(struct page *), gfp_flags);
-	if (pages == NULL) {
-		kfree(pdev);
-		return NULL;
-	}
-	for (i = 0; i < max_pages; i++) {
-		pages[i] = alloc_page(gfp_flags);
-		if (!pages[i])
-			goto out_free;
-	}
-
-	memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id));
-	pdev->layout_type = LAYOUT_NFSV4_1_FILES;
-	pdev->pages = pages;
-	pdev->pgbase = 0;
-	pdev->pglen = max_resp_sz;
-	pdev->mincount = 0;
-	pdev->maxcount = max_resp_sz - nfs41_maxgetdevinfo_overhead;
-
-	rc = nfs4_proc_getdeviceinfo(server, pdev, cred);
-	dprintk("%s getdevice info returns %d\n", __func__, rc);
-	if (rc)
-		goto out_free;
-
-	/*
-	 * Found new device, need to decode it and then add it to the
-	 * list of known devices for this mountpoint.
-	 */
-	dsaddr = decode_and_add_device(inode, pdev, gfp_flags);
-out_free:
-	for (i = 0; i < max_pages; i++)
-		__free_page(pages[i]);
-	kfree(pages);
-	kfree(pdev);
-	dprintk("<-- %s dsaddr %p\n", __func__, dsaddr);
-	return dsaddr;
-}
-
 void
 nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
 {
diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c
index ae05278b376..c502f640209 100644
--- a/fs/nfs/objlayout/objio_osd.c
+++ b/fs/nfs/objlayout/objio_osd.c
@@ -60,52 +60,6 @@ objio_free_deviceid_node(struct nfs4_deviceid_node *d)
 	kfree(de);
 }
 
-static struct objio_dev_ent *_dev_list_find(const struct nfs_server *nfss,
-	const struct nfs4_deviceid *d_id)
-{
-	struct nfs4_deviceid_node *d;
-	struct objio_dev_ent *de;
-
-	d = nfs4_find_get_deviceid(nfss->pnfs_curr_ld, nfss->nfs_client, d_id);
-	if (!d)
-		return NULL;
-
-	de = container_of(d, struct objio_dev_ent, id_node);
-	return de;
-}
-
-static struct objio_dev_ent *
-_dev_list_add(const struct nfs_server *nfss,
-	const struct nfs4_deviceid *d_id, struct osd_dev *od,
-	gfp_t gfp_flags)
-{
-	struct nfs4_deviceid_node *d;
-	struct objio_dev_ent *de = kzalloc(sizeof(*de), gfp_flags);
-	struct objio_dev_ent *n;
-
-	if (!de) {
-		dprintk("%s: -ENOMEM od=%p\n", __func__, od);
-		return NULL;
-	}
-
-	dprintk("%s: Adding od=%p\n", __func__, od);
-	nfs4_init_deviceid_node(&de->id_node,
-				nfss->pnfs_curr_ld,
-				nfss->nfs_client,
-				d_id);
-	de->od.od = od;
-
-	d = nfs4_insert_deviceid_node(&de->id_node);
-	n = container_of(d, struct objio_dev_ent, id_node);
-	if (n != de) {
-		dprintk("%s: Race with other n->od=%p\n", __func__, n->od.od);
-		objio_free_deviceid_node(&de->id_node);
-		de = n;
-	}
-
-	return de;
-}
-
 struct objio_segment {
 	struct pnfs_layout_segment lseg;
 
@@ -130,29 +84,24 @@ struct objio_state {
 
 /* Send and wait for a get_device_info of devices in the layout,
    then look them up with the osd_initiator library */
-static int objio_devices_lookup(struct pnfs_layout_hdr *pnfslay,
-	struct objio_segment *objio_seg, unsigned c, struct nfs4_deviceid *d_id,
-	gfp_t gfp_flags)
+struct nfs4_deviceid_node *
+objio_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
+			gfp_t gfp_flags)
 {
 	struct pnfs_osd_deviceaddr *deviceaddr;
-	struct objio_dev_ent *ode;
+	struct objio_dev_ent *ode = NULL;
 	struct osd_dev *od;
 	struct osd_dev_info odi;
 	bool retry_flag = true;
+	u32 *p;
 	int err;
 
-	ode = _dev_list_find(NFS_SERVER(pnfslay->plh_inode), d_id);
-	if (ode) {
-		objio_seg->oc.ods[c] = &ode->od; /* must use container_of */
-		return 0;
-	}
+	deviceaddr = kzalloc(sizeof(*deviceaddr), gfp_flags);
+	if (!deviceaddr)
+		return NULL;
 
-	err = objlayout_get_deviceinfo(pnfslay, d_id, &deviceaddr, gfp_flags);
-	if (unlikely(err)) {
-		dprintk("%s: objlayout_get_deviceinfo dev(%llx:%llx) =>%d\n",
-			__func__, _DEVID_LO(d_id), _DEVID_HI(d_id), err);
-		return err;
-	}
+	p = page_address(pdev->pages[0]);
+	pnfs_osd_xdr_decode_deviceaddr(deviceaddr, p);
 
 	odi.systemid_len = deviceaddr->oda_systemid.len;
 	if (odi.systemid_len > sizeof(odi.systemid)) {
@@ -188,14 +137,24 @@ retry_lookup:
 		goto out;
 	}
 
-	ode = _dev_list_add(NFS_SERVER(pnfslay->plh_inode), d_id, od,
-			    gfp_flags);
-	objio_seg->oc.ods[c] = &ode->od; /* must use container_of */
 	dprintk("Adding new dev_id(%llx:%llx)\n",
-		_DEVID_LO(d_id), _DEVID_HI(d_id));
+		_DEVID_LO(&pdev->dev_id), _DEVID_HI(&pdev->dev_id));
+
+	ode = kzalloc(sizeof(*ode), gfp_flags);
+	if (!ode) {
+		dprintk("%s: -ENOMEM od=%p\n", __func__, od);
+		goto out;
+	}
+
+	nfs4_init_deviceid_node(&ode->id_node, server, &pdev->dev_id);
+	kfree(deviceaddr);
+
+	ode->od.od = od;
+	return &ode->id_node;
+
 out:
-	objlayout_put_deviceinfo(deviceaddr);
-	return err;
+	kfree(deviceaddr);
+	return NULL;
 }
 
 static void copy_single_comp(struct ore_components *oc, unsigned c,
@@ -254,6 +213,7 @@ int objio_alloc_lseg(struct pnfs_layout_segment **outp,
 	struct xdr_stream *xdr,
 	gfp_t gfp_flags)
 {
+	struct nfs_server *server = NFS_SERVER(pnfslay->plh_inode);
 	struct objio_segment *objio_seg;
 	struct pnfs_osd_xdr_decode_layout_iter iter;
 	struct pnfs_osd_layout layout;
@@ -283,13 +243,21 @@ int objio_alloc_lseg(struct pnfs_layout_segment **outp,
 	objio_seg->oc.first_dev = layout.olo_comps_index;
 	cur_comp = 0;
 	while (pnfs_osd_xdr_decode_layout_comp(&src_comp, &iter, xdr, &err)) {
+		struct nfs4_deviceid_node *d;
+		struct objio_dev_ent *ode;
+
 		copy_single_comp(&objio_seg->oc, cur_comp, &src_comp);
-		err = objio_devices_lookup(pnfslay, objio_seg, cur_comp,
-					   &src_comp.oc_object_id.oid_device_id,
-					   gfp_flags);
-		if (err)
+
+		d = nfs4_find_get_deviceid(server,
+				&src_comp.oc_object_id.oid_device_id,
+				pnfslay->plh_lc_cred, gfp_flags);
+		if (!d) {
+			err = -ENXIO;
 			goto err;
-		++cur_comp;
+		}
+
+		ode = container_of(d, struct objio_dev_ent, id_node);
+		objio_seg->oc.ods[cur_comp++] = &ode->od;
 	}
 	/* pnfs_osd_xdr_decode_layout_comp returns false on error */
 	if (unlikely(err))
@@ -653,6 +621,7 @@ static struct pnfs_layoutdriver_type objlayout_type = {
 	.flags                   = PNFS_LAYOUTRET_ON_SETATTR |
 				   PNFS_LAYOUTRET_ON_ERROR,
 
+	.max_deviceinfo_size	 = PAGE_SIZE,
 	.owner		       	 = THIS_MODULE,
 	.alloc_layout_hdr        = objlayout_alloc_layout_hdr,
 	.free_layout_hdr         = objlayout_free_layout_hdr,
diff --git a/fs/nfs/objlayout/objlayout.c b/fs/nfs/objlayout/objlayout.c
index 697a16d11fa..c89357c7a91 100644
--- a/fs/nfs/objlayout/objlayout.c
+++ b/fs/nfs/objlayout/objlayout.c
@@ -574,76 +574,6 @@ loop_done:
 	dprintk("%s: Return\n", __func__);
 }
 
-
-/*
- * 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 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;
-	pd.maxcount = PAGE_SIZE;
-
-	err = nfs4_proc_getdeviceinfo(NFS_SERVER(pnfslay->plh_inode), &pd,
-			pnfslay->plh_lc_cred);
-	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);
-}
-
 enum {
 	OBJLAYOUT_MAX_URI_LEN = 256, OBJLAYOUT_MAX_OSDNAME_LEN = 64,
 	OBJLAYOUT_MAX_SYSID_HEX_LEN = OSD_SYSTEMID_LEN * 2 + 1,
diff --git a/fs/nfs/objlayout/objlayout.h b/fs/nfs/objlayout/objlayout.h
index fd13f1d2f13..3a0828d5733 100644
--- a/fs/nfs/objlayout/objlayout.h
+++ b/fs/nfs/objlayout/objlayout.h
@@ -149,11 +149,6 @@ extern void objlayout_read_done(struct objlayout_io_res *oir,
 extern void objlayout_write_done(struct objlayout_io_res *oir,
 				 ssize_t status, bool sync);
 
-extern int objlayout_get_deviceinfo(struct pnfs_layout_hdr *pnfslay,
-	struct nfs4_deviceid *d_id, struct pnfs_osd_deviceaddr **deviceaddr,
-	gfp_t gfp_flags);
-extern void objlayout_put_deviceinfo(struct pnfs_osd_deviceaddr *deviceaddr);
-
 /*
  * exported generic objects function vectors
  */
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 2c249422593..ce89ae364bb 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -84,6 +84,7 @@ struct pnfs_layoutdriver_type {
 	const char *name;
 	struct module *owner;
 	unsigned flags;
+	unsigned max_deviceinfo_size;
 
 	int (*set_layoutdriver) (struct nfs_server *, const struct nfs_fh *);
 	int (*clear_layoutdriver) (struct nfs_server *);
@@ -126,6 +127,9 @@ struct pnfs_layoutdriver_type {
 	enum pnfs_try_status (*write_pagelist)(struct nfs_pgio_header *, int);
 
 	void (*free_deviceid_node) (struct nfs4_deviceid_node *);
+	struct nfs4_deviceid_node * (*alloc_deviceid_node)
+			(struct nfs_server *server, struct pnfs_device *pdev,
+			gfp_t gfp_flags);
 
 	void (*encode_layoutreturn) (struct pnfs_layout_hdr *layoutid,
 				     struct xdr_stream *xdr,
@@ -261,11 +265,12 @@ struct nfs4_deviceid_node {
 	atomic_t			ref;
 };
 
-struct nfs4_deviceid_node *nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *);
+struct nfs4_deviceid_node *
+nfs4_find_get_deviceid(struct nfs_server *server,
+		const struct nfs4_deviceid *id, struct rpc_cred *cred,
+		gfp_t gfp_mask);
 void nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *);
-void nfs4_init_deviceid_node(struct nfs4_deviceid_node *,
-			     const struct pnfs_layoutdriver_type *,
-			     const struct nfs_client *,
+void nfs4_init_deviceid_node(struct nfs4_deviceid_node *, struct nfs_server *,
 			     const struct nfs4_deviceid *);
 struct nfs4_deviceid_node *nfs4_insert_deviceid_node(struct nfs4_deviceid_node *);
 bool nfs4_put_deviceid_node(struct nfs4_deviceid_node *);
diff --git a/fs/nfs/pnfs_dev.c b/fs/nfs/pnfs_dev.c
index 6da209bd940..791f8b3c4cf 100644
--- a/fs/nfs/pnfs_dev.c
+++ b/fs/nfs/pnfs_dev.c
@@ -29,6 +29,9 @@
  */
 
 #include <linux/export.h>
+#include <linux/nfs_fs.h>
+#include "nfs4session.h"
+#include "internal.h"
 #include "pnfs.h"
 
 #define NFSDBG_FACILITY		NFSDBG_PNFS
@@ -89,6 +92,74 @@ _lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
 	return NULL;
 }
 
+static struct nfs4_deviceid_node *
+nfs4_get_device_info(struct nfs_server *server,
+		const struct nfs4_deviceid *dev_id,
+		struct rpc_cred *cred, gfp_t gfp_flags)
+{
+	struct nfs4_deviceid_node *d = NULL;
+	struct pnfs_device *pdev = NULL;
+	struct page **pages = NULL;
+	u32 max_resp_sz;
+	int max_pages;
+	int rc, i;
+
+	/*
+	 * Use the session max response size as the basis for setting
+	 * GETDEVICEINFO's maxcount
+	 */
+	max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
+	if (server->pnfs_curr_ld->max_deviceinfo_size &&
+	    server->pnfs_curr_ld->max_deviceinfo_size < max_resp_sz)
+		max_resp_sz = server->pnfs_curr_ld->max_deviceinfo_size;
+	max_pages = nfs_page_array_len(0, max_resp_sz);
+	dprintk("%s: server %p max_resp_sz %u max_pages %d\n",
+		__func__, server, max_resp_sz, max_pages);
+
+	pdev = kzalloc(sizeof(*pdev), gfp_flags);
+	if (!pdev)
+		return NULL;
+
+	pages = kcalloc(max_pages, sizeof(struct page *), gfp_flags);
+	if (!pages)
+		goto out_free_pdev;
+
+	for (i = 0; i < max_pages; i++) {
+		pages[i] = alloc_page(gfp_flags);
+		if (!pages[i])
+			goto out_free_pages;
+	}
+
+	memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id));
+	pdev->layout_type = server->pnfs_curr_ld->id;
+	pdev->pages = pages;
+	pdev->pgbase = 0;
+	pdev->pglen = max_resp_sz;
+	pdev->mincount = 0;
+	pdev->maxcount = max_resp_sz - nfs41_maxgetdevinfo_overhead;
+
+	rc = nfs4_proc_getdeviceinfo(server, pdev, cred);
+	dprintk("%s getdevice info returns %d\n", __func__, rc);
+	if (rc)
+		goto out_free_pages;
+
+	/*
+	 * Found new device, need to decode it and then add it to the
+	 * list of known devices for this mountpoint.
+	 */
+	d = server->pnfs_curr_ld->alloc_deviceid_node(server, pdev,
+			gfp_flags);
+
+out_free_pages:
+	for (i = 0; i < max_pages; i++)
+		__free_page(pages[i]);
+	kfree(pages);
+out_free_pdev:
+	kfree(pdev);
+	dprintk("<-- %s d %p\n", __func__, d);
+	return d;
+}
+
 /*
  * Lookup a deviceid in cache and get a reference count on it if found
  *
@@ -96,14 +167,14 @@ _lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
  * @id deviceid to look up
  */
 static struct nfs4_deviceid_node *
-_find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
-		   const struct nfs_client *clp, const struct nfs4_deviceid *id,
-		   long hash)
+__nfs4_find_get_deviceid(struct nfs_server *server,
+		const struct nfs4_deviceid *id, long hash)
 {
 	struct nfs4_deviceid_node *d;
 
 	rcu_read_lock();
-	d = _lookup_deviceid(ld, clp, id, hash);
+	d = _lookup_deviceid(server->pnfs_curr_ld, server->nfs_client, id,
+			hash);
 	if (d != NULL)
 		atomic_inc(&d->ref);
 	rcu_read_unlock();
@@ -111,10 +182,33 @@ _find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
 }
 
 struct nfs4_deviceid_node *
-nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
-		       const struct nfs_client *clp, const struct nfs4_deviceid *id)
+nfs4_find_get_deviceid(struct nfs_server *server,
+		const struct nfs4_deviceid *id, struct rpc_cred *cred,
+		gfp_t gfp_mask)
 {
-	return _find_get_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
+	long hash = nfs4_deviceid_hash(id);
+	struct nfs4_deviceid_node *d, *new;
+
+	d = __nfs4_find_get_deviceid(server, id, hash);
+	if (d)
+		return d;
+
+	new = nfs4_get_device_info(server, id, cred, gfp_mask);
+	if (!new)
+		return new;
+
+	spin_lock(&nfs4_deviceid_lock);
+	d = __nfs4_find_get_deviceid(server, id, hash);
+	if (d) {
+		spin_unlock(&nfs4_deviceid_lock);
+		server->pnfs_curr_ld->free_deviceid_node(new);
+		return d;
+	}
+	hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
+	atomic_inc(&new->ref);
+	spin_unlock(&nfs4_deviceid_lock);
+
+	return new;
 }
 EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
 
@@ -151,15 +245,13 @@ nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
 EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);
 
 void
-nfs4_init_deviceid_node(struct nfs4_deviceid_node *d,
-			const struct pnfs_layoutdriver_type *ld,
-			const struct nfs_client *nfs_client,
+nfs4_init_deviceid_node(struct nfs4_deviceid_node *d, struct nfs_server *server,
 			const struct nfs4_deviceid *id)
 {
 	INIT_HLIST_NODE(&d->node);
 	INIT_HLIST_NODE(&d->tmpnode);
-	d->ld = ld;
-	d->nfs_client = nfs_client;
+	d->ld = server->pnfs_curr_ld;
+	d->nfs_client = server->nfs_client;
 	d->flags = 0;
 	d->deviceid = *id;
 	atomic_set(&d->ref, 1);
@@ -167,39 +259,6 @@ nfs4_init_deviceid_node(struct nfs4_deviceid_node *d,
 EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
 
 /*
- * Uniquely initialize and insert a deviceid node into cache
- *
- * @new new deviceid node
- *      Note that the caller must set up the following members:
- *        new->ld
- *        new->nfs_client
- *        new->deviceid
- *
- * @ret the inserted node, if none found, otherwise, the found entry.
- */
-struct nfs4_deviceid_node *
-nfs4_insert_deviceid_node(struct nfs4_deviceid_node *new)
-{
-	struct nfs4_deviceid_node *d;
-	long hash;
-
-	spin_lock(&nfs4_deviceid_lock);
-	hash = nfs4_deviceid_hash(&new->deviceid);
-	d = _find_get_deviceid(new->ld, new->nfs_client, &new->deviceid, hash);
-	if (d) {
-		spin_unlock(&nfs4_deviceid_lock);
-		return d;
-	}
-
-	hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
-	spin_unlock(&nfs4_deviceid_lock);
-	atomic_inc(&new->ref);
-
-	return new;
-}
-EXPORT_SYMBOL_GPL(nfs4_insert_deviceid_node);
-
-/*
  * Dereference a deviceid node and delete it when its reference count drops
  * to zero.
  *