[PATCH v1 13/25] pnfsblock: call and parse getdevicelist

[Jim Rees <rees@umich.edu>]

From: Fred Isaman <iisaman@citi.umich.edu>

Call GETDEVICELIST during mount, then call and parse GETDEVICEINFO
for each device returned.

[pnfsblock: get rid of deprecated xdr macros]
Signed-off-by: Jim Rees <rees@umich.edu>
[pnfsblock: fix pnfs_deviceid references]
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
[pnfsblock: fix print format warnings for sector_t and size_t]
[pnfs-block: #include <linux/vmalloc.h>]
[pnfsblock: no PNFS_NFS_SERVER]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[pnfsblock: fix bug determining size of striped volume]
[pnfsblock: fix oops when using multiple devices]
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Benny Halevy <benny@tonian.com>
---
 fs/nfs/blocklayout/blocklayout.c |  156 +++++++++++++++++++++++++++++++++++++-
 fs/nfs/blocklayout/blocklayout.h |   53 +++++++++++++-
 2 files changed, 207 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index fce66a9..01d85cf 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -33,6 +33,7 @@
 #include <linux/init.h>
 #include <linux/mount.h>
 #include <linux/namei.h>
+#include <linux/vmalloc.h>
 
 #include "blocklayout.h"
 
@@ -163,17 +164,170 @@ bl_cleanup_layoutcommit(struct pnfs_layout_hdr *lo,
 {
 }
 
+static void free_blk_mountid(struct block_mount_id *mid)
+{
+	if (mid) {
+		struct pnfs_block_dev *dev;
+		spin_lock(&mid->bm_lock);
+		while (!list_empty(&mid->bm_devlist)) {
+			dev = list_first_entry(&mid->bm_devlist,
+					       struct pnfs_block_dev,
+					       bm_node);
+			list_del(&dev->bm_node);
+			free_block_dev(dev);
+		}
+		spin_unlock(&mid->bm_lock);
+		kfree(mid);
+	}
+}
+
+/* This is mostly copied from the filelayout's get_device_info function.
+ * It seems much of this should be at the generic pnfs level.
+ */
+static struct pnfs_block_dev *
+nfs4_blk_get_deviceinfo(struct nfs_server *server, const struct nfs_fh *fh,
+			struct nfs4_deviceid *d_id,
+			struct list_head *sdlist)
+{
+	struct pnfs_device *dev;
+	struct pnfs_block_dev *rv = NULL;
+	u32 max_resp_sz;
+	int max_pages;
+	struct page **pages = NULL;
+	int i, rc;
+
+	/*
+	 * 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 = max_resp_sz >> PAGE_SHIFT;
+	dprintk("%s max_resp_sz %u max_pages %d\n",
+		__func__, max_resp_sz, max_pages);
+
+	dev = kmalloc(sizeof(*dev), GFP_NOFS);
+	if (!dev) {
+		dprintk("%s kmalloc failed\n", __func__);
+		return NULL;
+	}
+
+	pages = kzalloc(max_pages * sizeof(struct page *), GFP_NOFS);
+	if (pages == NULL) {
+		kfree(dev);
+		return NULL;
+	}
+	for (i = 0; i < max_pages; i++) {
+		pages[i] = alloc_page(GFP_NOFS);
+		if (!pages[i])
+			goto out_free;
+	}
+
+	/* set dev->area */
+	dev->area = vmap(pages, max_pages, VM_MAP, PAGE_KERNEL);
+	if (!dev->area)
+		goto out_free;
+
+	memcpy(&dev->dev_id, d_id, sizeof(*d_id));
+	dev->layout_type = LAYOUT_BLOCK_VOLUME;
+	dev->pages = pages;
+	dev->pgbase = 0;
+	dev->pglen = PAGE_SIZE * max_pages;
+	dev->mincount = 0;
+
+	dprintk("%s: dev_id: %s\n", __func__, dev->dev_id.data);
+	rc = nfs4_proc_getdeviceinfo(server, dev);
+	dprintk("%s getdevice info returns %d\n", __func__, rc);
+	if (rc)
+		goto out_free;
+
+	rv = nfs4_blk_decode_device(server, dev, sdlist);
+ out_free:
+	if (dev->area != NULL)
+		vunmap(dev->area);
+	for (i = 0; i < max_pages; i++)
+		__free_page(pages[i]);
+	kfree(pages);
+	kfree(dev);
+	return rv;
+}
+
 static int
 bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
 {
+	struct block_mount_id *b_mt_id = NULL;
+	struct pnfs_mount_type *mtype = NULL;
+	struct pnfs_devicelist *dlist = NULL;
+	struct pnfs_block_dev *bdev;
+	LIST_HEAD(block_disklist);
+	int status = 0, i;
+
 	dprintk("%s enter\n", __func__);
-	return 0;
+
+	if (server->pnfs_blksize == 0) {
+		dprintk("%s Server did not return blksize\n", __func__);
+		return -EINVAL;
+	}
+	b_mt_id = kzalloc(sizeof(struct block_mount_id), GFP_NOFS);
+	if (!b_mt_id) {
+		status = -ENOMEM;
+		goto out_error;
+	}
+	/* Initialize nfs4 block layout mount id */
+	spin_lock_init(&b_mt_id->bm_lock);
+	INIT_LIST_HEAD(&b_mt_id->bm_devlist);
+
+	dlist = kmalloc(sizeof(struct pnfs_devicelist), GFP_NOFS);
+	if (!dlist) {
+		status = -ENOMEM;
+		goto out_error;
+	}
+	dlist->eof = 0;
+	while (!dlist->eof) {
+		status = nfs4_proc_getdevicelist(server, fh, dlist);
+		if (status)
+			goto out_error;
+		dprintk("%s GETDEVICELIST numdevs=%i, eof=%i\n",
+			__func__, dlist->num_devs, dlist->eof);
+		/* For each device returned in dlist, call GETDEVICEINFO, and
+		 * decode the opaque topology encoding to create a flat
+		 * volume topology, matching VOLUME_SIMPLE disk signatures
+		 * to disks in the visible block disk list.
+		 * Construct an LVM meta device from the flat volume topology.
+		 */
+		for (i = 0; i < dlist->num_devs; i++) {
+			bdev = nfs4_blk_get_deviceinfo(server, fh,
+						     &dlist->dev_id[i],
+						     &block_disklist);
+			if (!bdev) {
+				status = -ENODEV;
+				goto out_error;
+			}
+			spin_lock(&b_mt_id->bm_lock);
+			list_add(&bdev->bm_node, &b_mt_id->bm_devlist);
+			spin_unlock(&b_mt_id->bm_lock);
+		}
+	}
+	dprintk("%s SUCCESS\n", __func__);
+	server->pnfs_ld_data = b_mt_id;
+
+ out_return:
+	kfree(dlist);
+	return status;
+
+ out_error:
+	free_blk_mountid(b_mt_id);
+	kfree(mtype);
+	goto out_return;
 }
 
 static int
 bl_clear_layoutdriver(struct nfs_server *server)
 {
+	struct block_mount_id *b_mt_id = server->pnfs_ld_data;
+
 	dprintk("%s enter\n", __func__);
+	free_blk_mountid(b_mt_id);
+	dprintk("%s RETURNS\n", __func__);
 	return 0;
 }
 
diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h
index d2d564a..ee402c7 100644
--- a/fs/nfs/blocklayout/blocklayout.h
+++ b/fs/nfs/blocklayout/blocklayout.h
@@ -38,12 +38,60 @@
 
 #include "../pnfs.h"
 
+struct block_mount_id {
+	spinlock_t			bm_lock;    /* protects list */
+	struct list_head		bm_devlist; /* holds pnfs_block_dev */
+};
+
 struct pnfs_block_dev {
 	struct list_head		bm_node;
 	struct nfs4_deviceid		bm_mdevid;    /* associated devid */
 	struct block_device		*bm_mdev;     /* meta device itself */
 };
 
+/* holds visible disks that can be matched against VOLUME_SIMPLE signatures */
+struct visible_block_device {
+	struct list_head	vi_node;
+	struct block_device	*vi_bdev;
+	int			vi_mapped;
+	int			vi_put_done;
+};
+
+enum blk_vol_type {
+	PNFS_BLOCK_VOLUME_SIMPLE   = 0,	/* maps to a single LU */
+	PNFS_BLOCK_VOLUME_SLICE    = 1,	/* slice of another volume */
+	PNFS_BLOCK_VOLUME_CONCAT   = 2,	/* concatenation of multiple volumes */
+	PNFS_BLOCK_VOLUME_STRIPE   = 3	/* striped across multiple volumes */
+};
+
+/* All disk offset/lengths are stored in 512-byte sectors */
+struct pnfs_blk_volume {
+	uint32_t		bv_type;
+	sector_t		bv_size;
+	struct pnfs_blk_volume	**bv_vols;
+	int			bv_vol_n;
+	union {
+		dev_t			bv_dev;
+		sector_t		bv_stripe_unit;
+		sector_t		bv_offset;
+	};
+};
+
+/* Since components need not be aligned, cannot use sector_t */
+struct pnfs_blk_sig_comp {
+	int64_t		bs_offset;  /* In bytes */
+	uint32_t	bs_length;  /* In bytes */
+	char		*bs_string;
+};
+
+/* Maximum number of signatures components in a simple volume */
+# define PNFS_BLOCK_MAX_SIG_COMP 16
+
+struct pnfs_blk_sig {
+	int				si_num_comps;
+	struct pnfs_blk_sig_comp	si_comps[PNFS_BLOCK_MAX_SIG_COMP];
+};
+
 enum exstate4 {
 	PNFS_BLOCK_READWRITE_DATA	= 0,
 	PNFS_BLOCK_READ_DATA		= 1,
@@ -99,7 +147,10 @@ struct pnfs_block_layout {
 	sector_t		bl_blocksize;  /* Server blocksize in sectors */
 };
 
-static inline struct pnfs_block_layout *BLK_LO2EXT(struct pnfs_layout_hdr *lo)
+#define BLK_ID(lo) ((struct block_mount_id *)(NFS_SERVER(lo->plh_inode)->pnfs_ld_data))
+
+static inline struct pnfs_block_layout *
+BLK_LO2EXT(struct pnfs_layout_hdr *lo)
 {
 	return container_of(lo, struct pnfs_block_layout, bl_layout);
 }
-- 
1.7.4.1