[PATCH v3 01/29] pnfs: CB_NOTIFY_DEVICEID

[Benny Halevy <bhalevy@panasas.com>]

From: Marc Eshel <eshel@almaden.ibm.com>

Note: This functionlaity is incomplete as all layout segments referring to
the 'to be removed device id' need to be reaped, and all in flight I/O drained.

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
---
 fs/nfs/callback.h          |   17 ++++++++
 fs/nfs/callback_proc.c     |   51 +++++++++++++++++++++++
 fs/nfs/callback_xdr.c      |   96 +++++++++++++++++++++++++++++++++++++++++++-
 fs/nfs/nfs4filelayout.c    |    1 +
 fs/nfs/nfs4filelayout.h    |    1 +
 fs/nfs/nfs4filelayoutdev.c |   38 +++++++++++++++++-
 fs/nfs/pnfs.h              |    3 +
 7 files changed, 205 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
index 46d93ce..b257383 100644
--- a/fs/nfs/callback.h
+++ b/fs/nfs/callback.h
@@ -167,6 +167,23 @@ extern unsigned nfs4_callback_layoutrecall(
 
 extern void nfs4_check_drain_bc_complete(struct nfs4_session *ses);
 extern void nfs4_cb_take_slot(struct nfs_client *clp);
+
+struct cb_devicenotifyitem {
+	uint32_t		cbd_notify_type;
+	uint32_t		cbd_layout_type;
+	struct nfs4_deviceid	cbd_dev_id;
+	uint32_t		cbd_immediate;
+};
+
+struct cb_devicenotifyargs {
+	int				 ndevs;
+	struct cb_devicenotifyitem	 *devs;
+};
+
+extern __be32 nfs4_callback_devicenotify(
+	struct cb_devicenotifyargs *args,
+	void *dummy, struct cb_process_state *cps);
+
 #endif /* CONFIG_NFS_V4_1 */
 extern int check_gss_callback_principal(struct nfs_client *, struct svc_rqst *);
 extern __be32 nfs4_callback_getattr(struct cb_getattrargs *args,
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 2f41dcce..975c8f2 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -241,6 +241,57 @@ static void pnfs_recall_all_layouts(struct nfs_client *clp)
 	do_callback_layoutrecall(clp, &args);
 }
 
+__be32 nfs4_callback_devicenotify(struct cb_devicenotifyargs *args,
+				  void *dummy, struct cb_process_state *cps)
+{
+	int i;
+	u32 res = 0;
+	struct nfs_client *clp = cps->clp;
+	struct nfs_server *server = NULL;
+
+	dprintk("%s: -->\n", __func__);
+
+	if (!clp) {
+		res = NFS4ERR_OP_NOT_IN_SESSION;
+		goto out;
+	}
+
+	for (i = 0; i < args->ndevs; i++) {
+		struct cb_devicenotifyitem *dev = &args->devs[i];
+
+		if (!server ||
+		    server->pnfs_curr_ld->id != dev->cbd_layout_type) {
+			rcu_read_lock();
+			list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
+				if (server->pnfs_curr_ld &&
+				    server->pnfs_curr_ld->id == dev->cbd_layout_type) {
+					rcu_read_unlock();
+					goto found;
+				}
+			rcu_read_unlock();
+			dprintk("%s: layout type %u not found\n",
+				__func__, dev->cbd_layout_type);
+			continue;
+		}
+
+	found:
+		if (!server->pnfs_curr_ld->delete_deviceid) {
+			res = NFS4ERR_NOTSUPP;
+			break;
+		}
+		if (dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE)
+			dprintk("%s: NOTIFY_DEVICEID4_CHANGE not supported, "
+				"deleting instead\n", __func__);
+		server->pnfs_curr_ld->delete_deviceid(&dev->cbd_dev_id);
+	}
+
+out:
+	kfree(args->devs);
+	dprintk("%s: exit with status = %u\n",
+		__func__, res);
+	return cpu_to_be32(res);
+}
+
 int nfs41_validate_delegation_stateid(struct nfs_delegation *delegation, const nfs4_stateid *stateid)
 {
 	if (delegation == NULL)
diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index 00ecf62..c6c86a7 100644
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -25,6 +25,7 @@
 
 #if defined(CONFIG_NFS_V4_1)
 #define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
+#define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
 #define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
 					4 + 1 + 3)
 #define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
@@ -284,6 +285,93 @@ out:
 	return status;
 }
 
+static
+__be32 decode_devicenotify_args(struct svc_rqst *rqstp,
+				struct xdr_stream *xdr,
+				struct cb_devicenotifyargs *args)
+{
+	__be32 *p;
+	__be32 status = 0;
+	u32 tmp;
+	int n, i;
+	args->ndevs = 0;
+
+	/* Num of device notifications */
+	p = read_buf(xdr, sizeof(uint32_t));
+	if (unlikely(p == NULL)) {
+		status = htonl(NFS4ERR_BADXDR);
+		goto out;
+	}
+	n = ntohl(*p++);
+	if (n <= 0)
+		goto out;
+
+	args->devs = kmalloc(n * sizeof(*args->devs), GFP_KERNEL);
+	if (!args->devs) {
+		status = htonl(NFS4ERR_DELAY);
+		goto out;
+	}
+
+	/* Decode each dev notification */
+	for (i = 0; i < n; i++) {
+		struct cb_devicenotifyitem *dev = &args->devs[i];
+
+		p = read_buf(xdr, (4 * sizeof(uint32_t)) + NFS4_DEVICEID4_SIZE);
+		if (unlikely(p == NULL)) {
+			status = htonl(NFS4ERR_BADXDR);
+			goto err;
+		}
+
+		tmp = ntohl(*p++);	/* bitmap size */
+		if (tmp != 1) {
+			status = htonl(NFS4ERR_INVAL);
+			goto err;
+		}
+		dev->cbd_notify_type = ntohl(*p++);
+		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
+		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
+			status = htonl(NFS4ERR_INVAL);
+			goto err;
+		}
+
+		tmp = ntohl(*p++);	/* opaque size */
+		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
+		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
+		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
+		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
+			status = htonl(NFS4ERR_INVAL);
+			goto err;
+		}
+		dev->cbd_layout_type = ntohl(*p++);
+		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
+		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
+
+		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
+			p = read_buf(xdr, sizeof(uint32_t));
+			if (unlikely(p == NULL)) {
+				status = htonl(NFS4ERR_BADXDR);
+				goto err;
+			}
+			dev->cbd_immediate = ntohl(*p++);
+		} else {
+			dev->cbd_immediate = 0;
+		}
+
+		args->ndevs++;
+
+		dprintk("%s: type %d layout 0x%x immediate %d\n",
+			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
+			dev->cbd_immediate);
+	}
+out:
+	dprintk("%s: status %d ndevs %d\n",
+		__func__, ntohl(status), args->ndevs);
+	return status;
+err:
+	kfree(args->devs);
+	goto out;
+}
+
 static __be32 decode_sessionid(struct xdr_stream *xdr,
 				 struct nfs4_sessionid *sid)
 {
@@ -639,10 +727,10 @@ preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 	case OP_CB_RECALL_ANY:
 	case OP_CB_RECALL_SLOT:
 	case OP_CB_LAYOUTRECALL:
+	case OP_CB_NOTIFY_DEVICEID:
 		*op = &callback_ops[op_nr];
 		break;
 
-	case OP_CB_NOTIFY_DEVICEID:
 	case OP_CB_NOTIFY:
 	case OP_CB_PUSH_DELEG:
 	case OP_CB_RECALLABLE_OBJ_AVAIL:
@@ -849,6 +937,12 @@ static struct callback_op callback_ops[] = {
 			(callback_decode_arg_t)decode_layoutrecall_args,
 		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
 	},
+	[OP_CB_NOTIFY_DEVICEID] = {
+		.process_op = (callback_process_op_t)nfs4_callback_devicenotify,
+		.decode_args =
+			(callback_decode_arg_t)decode_devicenotify_args,
+		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
+	},
 	[OP_CB_SEQUENCE] = {
 		.process_op = (callback_process_op_t)nfs4_callback_sequence,
 		.decode_args = (callback_decode_arg_t)decode_cb_sequence_args,
diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index e6e0c294..2feab7f 100644
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/nfs4filelayout.c
@@ -867,6 +867,7 @@ static struct pnfs_layoutdriver_type filelayout_type = {
 	.commit_pagelist	= filelayout_commit_pagelist,
 	.read_pagelist		= filelayout_read_pagelist,
 	.write_pagelist		= filelayout_write_pagelist,
+	.delete_deviceid	= filelayout_delete_deviceid,
 };
 
 static int __init nfs4filelayout_init(void)
diff --git a/fs/nfs/nfs4filelayout.h b/fs/nfs/nfs4filelayout.h
index 7c44579..8be70ab 100644
--- a/fs/nfs/nfs4filelayout.h
+++ b/fs/nfs/nfs4filelayout.h
@@ -105,5 +105,6 @@ nfs4_fl_find_get_deviceid(struct nfs4_deviceid *dev_id);
 extern void nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
 struct nfs4_file_layout_dsaddr *
 get_device_info(struct inode *inode, struct nfs4_deviceid *dev_id);
+void filelayout_delete_deviceid(struct nfs4_deviceid *);
 
 #endif /* FS_NFS_NFS4FILELAYOUT_H */
diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c
index de5350f..601aaea 100644
--- a/fs/nfs/nfs4filelayoutdev.c
+++ b/fs/nfs/nfs4filelayoutdev.c
@@ -601,7 +601,7 @@ void
 nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
 {
 	if (atomic_dec_and_lock(&dsaddr->ref, &filelayout_deviceid_lock)) {
-		hlist_del_rcu(&dsaddr->node);
+		hlist_del_init_rcu(&dsaddr->node);
 		spin_unlock(&filelayout_deviceid_lock);
 
 		synchronize_rcu();
@@ -631,6 +631,42 @@ fail:
 	return NULL;
 }
 
+static struct nfs4_file_layout_dsaddr *
+nfs4_fl_unhash_deviceid(struct nfs4_deviceid *id)
+{
+	struct nfs4_file_layout_dsaddr *d;
+	struct hlist_node *n;
+	long hash = nfs4_fl_deviceid_hash(id);
+
+	dprintk("%s: hash %ld\n", __func__, hash);
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(d, n, &filelayout_deviceid_cache[hash], node)
+		if (!memcmp(&d->deviceid, id, sizeof(*id)))
+			goto found;
+	rcu_read_unlock();
+	return NULL;
+
+found:
+	rcu_read_unlock();
+	spin_lock(&filelayout_deviceid_lock);
+	hlist_del_init_rcu(&d->node);
+	spin_unlock(&filelayout_deviceid_lock);
+	synchronize_rcu();
+
+	return d;
+}
+
+void
+filelayout_delete_deviceid(struct nfs4_deviceid *id)
+{
+	struct nfs4_file_layout_dsaddr *d;
+
+	d = nfs4_fl_unhash_deviceid(id);
+	/* balance the initial ref taken in decode_and_add_device */
+	if (d && atomic_dec_and_test(&d->ref))
+		nfs4_fl_free_deviceid(d);
+}
+
 /*
  * Want res = (offset - layout->pattern_offset)/ layout->stripe_unit
  * Then: ((res + fsi) % dsaddr->stripe_count)
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index bc48272..4cb0a0d 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -89,6 +89,9 @@ struct pnfs_layoutdriver_type {
 	 */
 	enum pnfs_try_status (*read_pagelist) (struct nfs_read_data *nfs_data);
 	enum pnfs_try_status (*write_pagelist) (struct nfs_write_data *nfs_data, int how);
+
+	/* device notification methods */
+	void (*delete_deviceid)(struct nfs4_deviceid *);
 };
 
 struct pnfs_layout_hdr {
-- 
1.7.3.4