nfsd: add SCSI layout support
authorChristoph Hellwig <hch@lst.de>
Fri, 4 Mar 2016 19:46:17 +0000 (20:46 +0100)
committerJ. Bruce Fields <bfields@redhat.com>
Fri, 18 Mar 2016 15:42:53 +0000 (11:42 -0400)
This is a simple extension to the block layout driver to use SCSI
persistent reservations for access control and fencing, as well as
SCSI VPD pages for device identification.

For this we need to pass the nfs4_client to the proc_getdeviceinfo method
to generate the reservation key, and add a new fence_client method
to allow for fence actions in the layout driver.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Documentation/filesystems/nfs/pnfs-scsi-server.txt [new file with mode: 0644]
fs/nfsd/Kconfig
fs/nfsd/Makefile
fs/nfsd/blocklayout.c
fs/nfsd/blocklayoutxdr.c
fs/nfsd/blocklayoutxdr.h
fs/nfsd/nfs4layouts.c
fs/nfsd/nfs4proc.c
fs/nfsd/pnfs.h
fs/xfs/Makefile
fs/xfs/xfs_pnfs.h

diff --git a/Documentation/filesystems/nfs/pnfs-scsi-server.txt b/Documentation/filesystems/nfs/pnfs-scsi-server.txt
new file mode 100644 (file)
index 0000000..5bef726
--- /dev/null
@@ -0,0 +1,23 @@
+
+pNFS SCSI layout server user guide
+==================================
+
+This document describes support for pNFS SCSI layouts in the Linux NFS server.
+With pNFS SCSI layouts, the NFS server acts as Metadata Server (MDS) for pNFS,
+which in addition to handling all the metadata access to the NFS export,
+also hands out layouts to the clients so that they can directly access the
+underlying SCSI LUNs that are shared with the client.
+
+To use pNFS SCSI layouts with with the Linux NFS server, the exported file
+system needs to support the pNFS SCSI layouts (currently just XFS), and the
+file system must sit on a SCSI LUN that is accessible to the clients in
+addition to the MDS.  As of now the file system needs to sit directly on the
+exported LUN, striping or concatenation of LUNs on the MDS and clients
+is not supported yet.
+
+On a server built with CONFIG_NFSD_SCSI, the pNFS SCSI volume support is
+automatically enabled if the file system is exported using the "pnfs"
+option and the underlying SCSI device support persistent reservations.
+On the client make sure the kernel has the CONFIG_PNFS_BLOCK option
+enabled, and the file system is mounted using the NFSv4.1 protocol
+version (mount -o vers=4.1).
index eb70d91b255b4a180df16cd071fcf04f72ed8ec2..a30a31316e68411f5d500f241c1f8f9b86518d5f 100644 (file)
@@ -98,6 +98,19 @@ config NFSD_BLOCKLAYOUT
 
          If unsure, say N.
 
+config NFSD_SCSILAYOUT
+       bool "NFSv4.1 server support for pNFS SCSI layouts"
+       depends on NFSD_V4
+       select NFSD_PNFS
+       help
+         This option enables support for the exporting pNFS SCSI layouts
+         in the kernel's NFS server. The pNFS SCSI layout enables NFS
+         clients to directly perform I/O to SCSI devices accesible to both
+         the server and the clients.  See draft-ietf-nfsv4-scsi-layout for
+         more details.
+
+         If unsure, say N.
+
 config NFSD_V4_SECURITY_LABEL
        bool "Provide Security Label support for NFSv4 server"
        depends on NFSD_V4 && SECURITY
index 679cdc6efee819bec16a84aca3ac5fbb3c40ed92..3ae5f3c77e28b15b532e25668a86403446dc4425 100644 (file)
@@ -19,3 +19,4 @@ nfsd-$(CONFIG_NFSD_V4)        += nfs4proc.o nfs4xdr.o nfs4state.o nfs4idmap.o \
                           nfs4acl.o nfs4callback.o nfs4recover.o
 nfsd-$(CONFIG_NFSD_PNFS) += nfs4layouts.o
 nfsd-$(CONFIG_NFSD_BLOCKLAYOUT) += blocklayout.o blocklayoutxdr.o
+nfsd-$(CONFIG_NFSD_SCSILAYOUT) += blocklayout.o blocklayoutxdr.o
index f00fa918e0f635678cd9780e37da8a63b5fc977f..e55b5242614da7a9d209db34e8c0f6519cf69446 100644 (file)
@@ -1,11 +1,14 @@
 /*
- * Copyright (c) 2014 Christoph Hellwig.
+ * Copyright (c) 2014-2016 Christoph Hellwig.
  */
 #include <linux/exportfs.h>
 #include <linux/genhd.h>
 #include <linux/slab.h>
+#include <linux/pr.h>
 
 #include <linux/nfsd/debug.h>
+#include <scsi/scsi_proto.h>
+#include <scsi/scsi_common.h>
 
 #include "blocklayoutxdr.h"
 #include "pnfs.h"
@@ -159,6 +162,7 @@ nfsd4_block_get_device_info_simple(struct super_block *sb,
 
 static __be32
 nfsd4_block_proc_getdeviceinfo(struct super_block *sb,
+               struct nfs4_client *clp,
                struct nfsd4_getdeviceinfo *gdp)
 {
        if (sb->s_bdev != sb->s_bdev->bd_contains)
@@ -200,3 +204,205 @@ const struct nfsd4_layout_ops bl_layout_ops = {
        .proc_layoutcommit      = nfsd4_block_proc_layoutcommit,
 };
 #endif /* CONFIG_NFSD_BLOCKLAYOUT */
+
+#ifdef CONFIG_NFSD_SCSILAYOUT
+static int nfsd4_scsi_identify_device(struct block_device *bdev,
+               struct pnfs_block_volume *b)
+{
+       struct request_queue *q = bdev->bd_disk->queue;
+       struct request *rq;
+       size_t bufflen = 252, len, id_len;
+       u8 *buf, *d, type, assoc;
+       int error;
+
+       buf = kzalloc(bufflen, GFP_KERNEL);
+       if (!buf)
+               return -ENOMEM;
+
+       rq = blk_get_request(q, READ, GFP_KERNEL);
+       if (IS_ERR(rq)) {
+               error = -ENOMEM;
+               goto out_free_buf;
+       }
+       blk_rq_set_block_pc(rq);
+
+       error = blk_rq_map_kern(q, rq, buf, bufflen, GFP_KERNEL);
+       if (error)
+               goto out_put_request;
+
+       rq->cmd[0] = INQUIRY;
+       rq->cmd[1] = 1;
+       rq->cmd[2] = 0x83;
+       rq->cmd[3] = bufflen >> 8;
+       rq->cmd[4] = bufflen & 0xff;
+       rq->cmd_len = COMMAND_SIZE(INQUIRY);
+
+       error = blk_execute_rq(rq->q, NULL, rq, 1);
+       if (error) {
+               pr_err("pNFS: INQUIRY 0x83 failed with: %x\n",
+                       rq->errors);
+               goto out_put_request;
+       }
+
+       len = (buf[2] << 8) + buf[3] + 4;
+       if (len > bufflen) {
+               pr_err("pNFS: INQUIRY 0x83 response invalid (len = %zd)\n",
+                       len);
+               goto out_put_request;
+       }
+
+       d = buf + 4;
+       for (d = buf + 4; d < buf + len; d += id_len + 4) {
+               id_len = d[3];
+               type = d[1] & 0xf;
+               assoc = (d[1] >> 4) & 0x3;
+
+               /*
+                * We only care about a EUI-64 and NAA designator types
+                * with LU association.
+                */
+               if (assoc != 0x00)
+                       continue;
+               if (type != 0x02 && type != 0x03)
+                       continue;
+               if (id_len != 8 && id_len != 12 && id_len != 16)
+                       continue;
+
+               b->scsi.code_set = PS_CODE_SET_BINARY;
+               b->scsi.designator_type = type == 0x02 ?
+                       PS_DESIGNATOR_EUI64 : PS_DESIGNATOR_NAA;
+               b->scsi.designator_len = id_len;
+               memcpy(b->scsi.designator, d + 4, id_len);
+
+               /*
+                * If we found a 8 or 12 byte descriptor continue on to
+                * see if a 16 byte one is available.  If we find a
+                * 16 byte descriptor we're done.
+                */
+               if (id_len == 16)
+                       break;
+       }
+
+out_put_request:
+       blk_put_request(rq);
+out_free_buf:
+       kfree(buf);
+       return error;
+}
+
+#define NFSD_MDS_PR_KEY                0x0100000000000000
+
+/*
+ * We use the client ID as a unique key for the reservations.
+ * This allows us to easily fence a client when recalls fail.
+ */
+static u64 nfsd4_scsi_pr_key(struct nfs4_client *clp)
+{
+       return ((u64)clp->cl_clientid.cl_boot << 32) | clp->cl_clientid.cl_id;
+}
+
+static int
+nfsd4_block_get_device_info_scsi(struct super_block *sb,
+               struct nfs4_client *clp,
+               struct nfsd4_getdeviceinfo *gdp)
+{
+       struct pnfs_block_deviceaddr *dev;
+       struct pnfs_block_volume *b;
+       const struct pr_ops *ops;
+       int error;
+
+       dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
+                     sizeof(struct pnfs_block_volume), GFP_KERNEL);
+       if (!dev)
+               return -ENOMEM;
+       gdp->gd_device = dev;
+
+       dev->nr_volumes = 1;
+       b = &dev->volumes[0];
+
+       b->type = PNFS_BLOCK_VOLUME_SCSI;
+       b->scsi.pr_key = nfsd4_scsi_pr_key(clp);
+
+       error = nfsd4_scsi_identify_device(sb->s_bdev, b);
+       if (error)
+               return error;
+
+       ops = sb->s_bdev->bd_disk->fops->pr_ops;
+       if (!ops) {
+               pr_err("pNFS: device %s does not support PRs.\n",
+                       sb->s_id);
+               return -EINVAL;
+       }
+
+       error = ops->pr_register(sb->s_bdev, 0, NFSD_MDS_PR_KEY, true);
+       if (error) {
+               pr_err("pNFS: failed to register key for device %s.\n",
+                       sb->s_id);
+               return -EINVAL;
+       }
+
+       error = ops->pr_reserve(sb->s_bdev, NFSD_MDS_PR_KEY,
+                       PR_EXCLUSIVE_ACCESS_REG_ONLY, 0);
+       if (error) {
+               pr_err("pNFS: failed to reserve device %s.\n",
+                       sb->s_id);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static __be32
+nfsd4_scsi_proc_getdeviceinfo(struct super_block *sb,
+               struct nfs4_client *clp,
+               struct nfsd4_getdeviceinfo *gdp)
+{
+       if (sb->s_bdev != sb->s_bdev->bd_contains)
+               return nfserr_inval;
+       return nfserrno(nfsd4_block_get_device_info_scsi(sb, clp, gdp));
+}
+static __be32
+nfsd4_scsi_proc_layoutcommit(struct inode *inode,
+               struct nfsd4_layoutcommit *lcp)
+{
+       struct iomap *iomaps;
+       int nr_iomaps;
+
+       nr_iomaps = nfsd4_scsi_decode_layoutupdate(lcp->lc_up_layout,
+                       lcp->lc_up_len, &iomaps, 1 << inode->i_blkbits);
+       if (nr_iomaps < 0)
+               return nfserrno(nr_iomaps);
+
+       return nfsd4_block_commit_blocks(inode, lcp, iomaps, nr_iomaps);
+}
+
+static void
+nfsd4_scsi_fence_client(struct nfs4_layout_stateid *ls)
+{
+       struct nfs4_client *clp = ls->ls_stid.sc_client;
+       struct block_device *bdev = ls->ls_file->f_path.mnt->mnt_sb->s_bdev;
+
+       bdev->bd_disk->fops->pr_ops->pr_preempt(bdev, NFSD_MDS_PR_KEY,
+                       nfsd4_scsi_pr_key(clp), 0, true);
+}
+
+const struct nfsd4_layout_ops scsi_layout_ops = {
+       /*
+        * Pretend that we send notification to the client.  This is a blatant
+        * lie to force recent Linux clients to cache our device IDs.
+        * We rarely ever change the device ID, so the harm of leaking deviceids
+        * for a while isn't too bad.  Unfortunately RFC5661 is a complete mess
+        * in this regard, but I filed errata 4119 for this a while ago, and
+        * hopefully the Linux client will eventually start caching deviceids
+        * without this again.
+        */
+       .notify_types           =
+                       NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
+       .proc_getdeviceinfo     = nfsd4_scsi_proc_getdeviceinfo,
+       .encode_getdeviceinfo   = nfsd4_block_encode_getdeviceinfo,
+       .proc_layoutget         = nfsd4_block_proc_layoutget,
+       .encode_layoutget       = nfsd4_block_encode_layoutget,
+       .proc_layoutcommit      = nfsd4_scsi_proc_layoutcommit,
+       .fence_client           = nfsd4_scsi_fence_client,
+};
+#endif /* CONFIG_NFSD_SCSILAYOUT */
index 6d834dc9bbc826bf8b711fb4adfaf58c82ae5c48..ca1883668810145b279ad54cce08b94ba639ae4e 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 Christoph Hellwig.
+ * Copyright (c) 2014-2016 Christoph Hellwig.
  */
 #include <linux/sunrpc/svc.h>
 #include <linux/exportfs.h>
@@ -53,6 +53,18 @@ nfsd4_block_encode_volume(struct xdr_stream *xdr, struct pnfs_block_volume *b)
                p = xdr_encode_hyper(p, b->simple.offset);
                p = xdr_encode_opaque(p, b->simple.sig, b->simple.sig_len);
                break;
+       case PNFS_BLOCK_VOLUME_SCSI:
+               len = 4 + 4 + 4 + 4 + b->scsi.designator_len + 8;
+               p = xdr_reserve_space(xdr, len);
+               if (!p)
+                       return -ETOOSMALL;
+
+               *p++ = cpu_to_be32(b->type);
+               *p++ = cpu_to_be32(b->scsi.code_set);
+               *p++ = cpu_to_be32(b->scsi.designator_type);
+               p = xdr_encode_opaque(p, b->scsi.designator, b->scsi.designator_len);
+               p = xdr_encode_hyper(p, b->scsi.pr_key);
+               break;
        default:
                return -ENOTSUPP;
        }
@@ -155,3 +167,54 @@ fail:
        kfree(iomaps);
        return -EINVAL;
 }
+
+int
+nfsd4_scsi_decode_layoutupdate(__be32 *p, u32 len, struct iomap **iomapp,
+               u32 block_size)
+{
+       struct iomap *iomaps;
+       u32 nr_iomaps, expected, i;
+
+       if (len < sizeof(u32)) {
+               dprintk("%s: extent array too small: %u\n", __func__, len);
+               return -EINVAL;
+       }
+
+       nr_iomaps = be32_to_cpup(p++);
+       expected = sizeof(__be32) + nr_iomaps * PNFS_SCSI_RANGE_SIZE;
+       if (len != expected) {
+               dprintk("%s: extent array size mismatch: %u/%u\n",
+                       __func__, len, expected);
+               return -EINVAL;
+       }
+
+       iomaps = kcalloc(nr_iomaps, sizeof(*iomaps), GFP_KERNEL);
+       if (!iomaps) {
+               dprintk("%s: failed to allocate extent array\n", __func__);
+               return -ENOMEM;
+       }
+
+       for (i = 0; i < nr_iomaps; i++) {
+               u64 val;
+
+               p = xdr_decode_hyper(p, &val);
+               if (val & (block_size - 1)) {
+                       dprintk("%s: unaligned offset 0x%llx\n", __func__, val);
+                       goto fail;
+               }
+               iomaps[i].offset = val;
+
+               p = xdr_decode_hyper(p, &val);
+               if (val & (block_size - 1)) {
+                       dprintk("%s: unaligned length 0x%llx\n", __func__, val);
+                       goto fail;
+               }
+               iomaps[i].length = val;
+       }
+
+       *iomapp = iomaps;
+       return nr_iomaps;
+fail:
+       kfree(iomaps);
+       return -EINVAL;
+}
index 6de925fe84991d09081dce75db8c8cd4ba12dded..397bc7563a4927c9673e5715bbb79e0cd1c6006b 100644 (file)
@@ -15,6 +15,11 @@ struct pnfs_block_extent {
        enum pnfs_block_extent_state    es;
 };
 
+struct pnfs_block_range {
+       u64                             foff;
+       u64                             len;
+};
+
 /*
  * Random upper cap for the uuid length to avoid unbounded allocation.
  * Not actually limited by the protocol.
@@ -29,6 +34,13 @@ struct pnfs_block_volume {
                        u32             sig_len;
                        u8              sig[PNFS_BLOCK_UUID_LEN];
                } simple;
+               struct {
+                       enum scsi_code_set              code_set;
+                       enum scsi_designator_type       designator_type;
+                       int                             designator_len;
+                       u8                              designator[256];
+                       u64                             pr_key;
+               } scsi;
        };
 };
 
@@ -43,5 +55,7 @@ __be32 nfsd4_block_encode_layoutget(struct xdr_stream *xdr,
                struct nfsd4_layoutget *lgp);
 int nfsd4_block_decode_layoutupdate(__be32 *p, u32 len, struct iomap **iomapp,
                u32 block_size);
+int nfsd4_scsi_decode_layoutupdate(__be32 *p, u32 len, struct iomap **iomapp,
+               u32 block_size);
 
 #endif /* _NFSD_BLOCKLAYOUTXDR_H */
index 4e4def77ebc7350d5f333f76050da939f85ffe52..825c7bc8d789716749138583953c26e630294a93 100644 (file)
@@ -1,6 +1,7 @@
 /*
  * Copyright (c) 2014 Christoph Hellwig.
  */
+#include <linux/blkdev.h>
 #include <linux/kmod.h>
 #include <linux/file.h>
 #include <linux/jhash.h>
@@ -29,6 +30,9 @@ const struct nfsd4_layout_ops *nfsd4_layout_ops[LAYOUT_TYPE_MAX] =  {
 #ifdef CONFIG_NFSD_BLOCKLAYOUT
        [LAYOUT_BLOCK_VOLUME]   = &bl_layout_ops,
 #endif
+#ifdef CONFIG_NFSD_SCSILAYOUT
+       [LAYOUT_SCSI]           = &scsi_layout_ops,
+#endif
 };
 
 /* pNFS device ID to export fsid mapping */
@@ -123,12 +127,24 @@ void nfsd4_setup_layout_type(struct svc_export *exp)
        if (!(exp->ex_flags & NFSEXP_PNFS))
                return;
 
+       /*
+        * Check if the file system supports exporting a block-like layout.
+        * If the block device supports reservations prefer the SCSI layout,
+        * otherwise advertise the block layout.
+        */
 #ifdef CONFIG_NFSD_BLOCKLAYOUT
        if (sb->s_export_op->get_uuid &&
            sb->s_export_op->map_blocks &&
            sb->s_export_op->commit_blocks)
                exp->ex_layout_type = LAYOUT_BLOCK_VOLUME;
 #endif
+#ifdef CONFIG_NFSD_SCSILAYOUT
+       /* overwrite block layout selection if needed */
+       if (sb->s_export_op->map_blocks &&
+           sb->s_export_op->commit_blocks &&
+           sb->s_bdev && sb->s_bdev->bd_disk->fops->pr_ops)
+               exp->ex_layout_type = LAYOUT_SCSI;
+#endif
 }
 
 static void
@@ -594,8 +610,6 @@ nfsd4_cb_layout_fail(struct nfs4_layout_stateid *ls)
 
        rpc_ntop((struct sockaddr *)&clp->cl_addr, addr_str, sizeof(addr_str));
 
-       trace_layout_recall_fail(&ls->ls_stid.sc_stateid);
-
        printk(KERN_WARNING
                "nfsd: client %s failed to respond to layout recall. "
                "  Fencing..\n", addr_str);
@@ -630,6 +644,7 @@ nfsd4_cb_layout_done(struct nfsd4_callback *cb, struct rpc_task *task)
                container_of(cb, struct nfs4_layout_stateid, ls_recall);
        struct nfsd_net *nn;
        ktime_t now, cutoff;
+       const struct nfsd4_layout_ops *ops;
        LIST_HEAD(reaplist);
 
 
@@ -665,7 +680,13 @@ nfsd4_cb_layout_done(struct nfsd4_callback *cb, struct rpc_task *task)
                /*
                 * Unknown error or non-responding client, we'll need to fence.
                 */
-               nfsd4_cb_layout_fail(ls);
+               trace_layout_recall_fail(&ls->ls_stid.sc_stateid);
+
+               ops = nfsd4_layout_ops[ls->ls_layout_type];
+               if (ops->fence_client)
+                       ops->fence_client(ls);
+               else
+                       nfsd4_cb_layout_fail(ls);
                return -1;
        }
 }
index 40b912407d5149288de1fd01e02c925be11acd76..de1ff1d98bb188a5661893f25e67926b70f7182f 100644 (file)
@@ -1268,8 +1268,10 @@ nfsd4_getdeviceinfo(struct svc_rqst *rqstp,
                goto out;
 
        nfserr = nfs_ok;
-       if (gdp->gd_maxcount != 0)
-               nfserr = ops->proc_getdeviceinfo(exp->ex_path.mnt->mnt_sb, gdp);
+       if (gdp->gd_maxcount != 0) {
+               nfserr = ops->proc_getdeviceinfo(exp->ex_path.mnt->mnt_sb,
+                                       cstate->session->se_client, gdp);
+       }
 
        gdp->gd_notify_types &= ops->notify_types;
 out:
index ff50bfa1f76fb742af46d52c19fcedf3367d3ded..7d073b9b1553041d32910ef41de7883a90af3b37 100644 (file)
@@ -21,6 +21,7 @@ struct nfsd4_layout_ops {
        u32             notify_types;
 
        __be32 (*proc_getdeviceinfo)(struct super_block *sb,
+                       struct nfs4_client *clp,
                        struct nfsd4_getdeviceinfo *gdevp);
        __be32 (*encode_getdeviceinfo)(struct xdr_stream *xdr,
                        struct nfsd4_getdeviceinfo *gdevp);
@@ -32,12 +33,17 @@ struct nfsd4_layout_ops {
 
        __be32 (*proc_layoutcommit)(struct inode *inode,
                        struct nfsd4_layoutcommit *lcp);
+
+       void (*fence_client)(struct nfs4_layout_stateid *ls);
 };
 
 extern const struct nfsd4_layout_ops *nfsd4_layout_ops[];
 #ifdef CONFIG_NFSD_BLOCKLAYOUT
 extern const struct nfsd4_layout_ops bl_layout_ops;
 #endif
+#ifdef CONFIG_NFSD_SCSILAYOUT
+extern const struct nfsd4_layout_ops scsi_layout_ops;
+#endif
 
 __be32 nfsd4_preprocess_layout_stateid(struct svc_rqst *rqstp,
                struct nfsd4_compound_state *cstate, stateid_t *stateid,
index d68b62a765920ae527637a556fa6b58e40cfea37..3542d94fddce5ca4a45e33e08a25fc894b2264eb 100644 (file)
@@ -122,3 +122,4 @@ xfs-$(CONFIG_XFS_POSIX_ACL) += xfs_acl.o
 xfs-$(CONFIG_SYSCTL)           += xfs_sysctl.o
 xfs-$(CONFIG_COMPAT)           += xfs_ioctl32.o
 xfs-$(CONFIG_NFSD_BLOCKLAYOUT) += xfs_pnfs.o
+xfs-$(CONFIG_NFSD_SCSILAYOUT)  += xfs_pnfs.o
index d85529ca299e5fa34da076daea58007ad472a21b..93f74853961b1cce598f5b83e96e622457ae173e 100644 (file)
@@ -1,7 +1,7 @@
 #ifndef _XFS_PNFS_H
 #define _XFS_PNFS_H 1
 
-#ifdef CONFIG_NFSD_BLOCKLAYOUT
+#if defined(CONFIG_NFSD_BLOCKLAYOUT) || defined(CONFIG_NFSD_SCSILAYOUT)
 int xfs_fs_get_uuid(struct super_block *sb, u8 *buf, u32 *len, u64 *offset);
 int xfs_fs_map_blocks(struct inode *inode, loff_t offset, u64 length,
                struct iomap *iomap, bool write, u32 *device_generation);
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