afs: Add an address list concept

Add an RCU replaceable address list structure to hold a list of server
addresses.  The list also holds the

To this end:

 (1) A cell's VL server address list can be loaded directly via insmod or
     echo to /proc/fs/afs/cells or dynamically from a DNS query for AFSDB
     or SRV records.

 (2) Anyone wanting to use a cell's VL server address must wait until the
     cell record comes online and has tried to obtain some addresses.

 (3) An FS server's address list, for the moment, has a single entry that
     is the key to the server list.  This will change in the future when a
     server is instead keyed on its UUID and the VL.GetAddrsU operation is
     used.

 (4) An 'address cursor' concept is introduced to handle iteration through
     the address list.  This is passed to the afs_make_call() as, in the
     future, stuff (such as abort code) that doesn't outlast the call will
     be returned in it.

In the future, we might want to annotate the list with information about
how each address fares.  We might then want to propagate such annotations
over address list replacement.

Whilst we're at it, we allow IPv6 addresses to be specified in
colon-delimited lists by enclosing them in square brackets.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 147 insertions, 245 deletions

diff --git a/fs/afs/vnode.c b/fs/afs/vnode.c
index 622e1100099b..9c7333eb01c2 100644
--- a/fs/afs/vnode.c
+++ b/fs/afs/vnode.c
@@ -44,30 +44,26 @@ static void afs_vnode_deleted_remotely(struct afs_vnode *vnode)
 void afs_vnode_finalise_status_update(struct afs_vnode *vnode,
 				      struct afs_server *server)
 {
-	struct afs_server *oldserver = NULL;
-
-	_enter("%p,%p", vnode, server);
-
 	spin_lock(&vnode->lock);
 	vnode->update_cnt--;
 	ASSERTCMP(vnode->update_cnt, >=, 0);
 	spin_unlock(&vnode->lock);
 
 	wake_up_all(&vnode->update_waitq);
-	afs_put_server(afs_v2net(vnode), oldserver);
 	_leave("");
 }
 
 /*
  * finish off updating the recorded status of a file after an operation failed
  */
-static void afs_vnode_status_update_failed(struct afs_vnode *vnode, int ret)
+static void afs_vnode_status_update_failed(struct afs_fs_cursor *fc,
+					   struct afs_vnode *vnode)
 {
-	_enter("{%x:%u},%d", vnode->fid.vid, vnode->fid.vnode, ret);
+	_enter("{%x:%u},%d", vnode->fid.vid, vnode->fid.vnode, fc->ac.error);
 
 	spin_lock(&vnode->lock);
 
-	if (ret == -ENOENT) {
+	if (fc->ac.error == -ENOENT) {
 		/* the file was deleted on the server */
 		_debug("got NOENT from server - marking file deleted");
 		afs_vnode_deleted_remotely(vnode);
@@ -90,9 +86,8 @@ static void afs_vnode_status_update_failed(struct afs_vnode *vnode, int ret)
  */
 int afs_vnode_fetch_status(struct afs_vnode *vnode, struct key *key, bool force)
 {
-	struct afs_server *server;
+	struct afs_fs_cursor fc;
 	unsigned int cb_break = 0;
-	int ret;
 
 	DECLARE_WAITQUEUE(myself, current);
 
@@ -172,43 +167,37 @@ get_anyway:
 
 	/* merge AFS status fetches and clear outstanding callback on this
 	 * vnode */
+	afs_init_fs_cursor(&fc, vnode);
 	do {
 		/* pick a server to query */
-		server = afs_volume_pick_fileserver(vnode);
-		if (IS_ERR(server))
+		if (!afs_volume_pick_fileserver(&fc, vnode))
 			goto no_server;
 
-		_debug("USING SERVER: %p{%pIS}",
-		       server, &server->addr.transport);
-
-		ret = afs_fs_fetch_file_status(server, key, vnode, NULL,
-					       false);
+		fc.ac.error = afs_fs_fetch_file_status(&fc, key, vnode, NULL, false);
 
-	} while (!afs_volume_release_fileserver(vnode, server, ret));
+	} while (afs_iterate_fs_cursor(&fc, vnode));
 
 	/* adjust the flags */
-	if (ret == 0) {
+	if (fc.ac.error == 0) {
 		_debug("adjust");
 		afs_cache_permit(vnode, key, cb_break);
-		afs_vnode_finalise_status_update(vnode, server);
-		afs_put_server(afs_v2net(vnode), server);
+		afs_vnode_finalise_status_update(vnode, fc.server);
 	} else {
-		_debug("failed [%d]", ret);
-		afs_vnode_status_update_failed(vnode, ret);
+		_debug("failed [%d]", fc.ac.error);
+		afs_vnode_status_update_failed(&fc, vnode);
 	}
 
+out:
+	afs_end_fs_cursor(&fc, afs_v2net(vnode));
 	ASSERTCMP(vnode->update_cnt, >=, 0);
-
-	_leave(" = %d [cnt %d]", ret, vnode->update_cnt);
-	return ret;
+	_leave(" = %d [cnt %d]", fc.ac.error, vnode->update_cnt);
+	return fc.ac.error;
 
 no_server:
 	spin_lock(&vnode->lock);
 	vnode->update_cnt--;
-	ASSERTCMP(vnode->update_cnt, >=, 0);
 	spin_unlock(&vnode->lock);
-	_leave(" = %ld [cnt %d]", PTR_ERR(server), vnode->update_cnt);
-	return PTR_ERR(server);
+	goto out;
 }
 
 /*
@@ -218,8 +207,7 @@ no_server:
 int afs_vnode_fetch_data(struct afs_vnode *vnode, struct key *key,
 			 struct afs_read *desc)
 {
-	struct afs_server *server;
-	int ret;
+	struct afs_fs_cursor fc;
 
 	_enter("%s{%x:%u.%u},%x,,,",
 	       vnode->volume->vlocation->vldb.name,
@@ -235,36 +223,31 @@ int afs_vnode_fetch_data(struct afs_vnode *vnode, struct key *key,
 
 	/* merge in AFS status fetches and clear outstanding callback on this
 	 * vnode */
+	afs_init_fs_cursor(&fc, vnode);
 	do {
 		/* pick a server to query */
-		server = afs_volume_pick_fileserver(vnode);
-		if (IS_ERR(server))
+		if (!afs_volume_pick_fileserver(&fc, vnode))
 			goto no_server;
 
-		_debug("USING SERVER: %pIS\n", &server->addr.transport);
-
-		ret = afs_fs_fetch_data(server, key, vnode, desc,
-					false);
+		fc.ac.error = afs_fs_fetch_data(&fc, key, vnode, desc, false);
 
-	} while (!afs_volume_release_fileserver(vnode, server, ret));
+	} while (afs_iterate_fs_cursor(&fc, vnode));
 
 	/* adjust the flags */
-	if (ret == 0) {
-		afs_vnode_finalise_status_update(vnode, server);
-		afs_put_server(afs_v2net(vnode), server);
-	} else {
-		afs_vnode_status_update_failed(vnode, ret);
-	}
+	if (fc.ac.error == 0)
+		afs_vnode_finalise_status_update(vnode, fc.server);
+	else
+		afs_vnode_status_update_failed(&fc, vnode);
 
-	_leave(" = %d", ret);
-	return ret;
+out:
+	return afs_end_fs_cursor(&fc, afs_v2net(vnode));
 
 no_server:
 	spin_lock(&vnode->lock);
 	vnode->update_cnt--;
 	ASSERTCMP(vnode->update_cnt, >=, 0);
 	spin_unlock(&vnode->lock);
-	return PTR_ERR(server);
+	goto out;
 }
 
 /*
@@ -275,8 +258,7 @@ int afs_vnode_create(struct afs_vnode *vnode, struct key *key,
 		     struct afs_file_status *newstatus,
 		     struct afs_callback *newcb, struct afs_server **_server)
 {
-	struct afs_server *server;
-	int ret;
+	struct afs_fs_cursor fc;
 
 	_enter("%s{%x:%u.%u},%x,%s,,",
 	       vnode->volume->vlocation->vldb.name,
@@ -291,38 +273,36 @@ int afs_vnode_create(struct afs_vnode *vnode, struct key *key,
 	vnode->update_cnt++;
 	spin_unlock(&vnode->lock);
 
+	afs_init_fs_cursor(&fc, vnode);
 	do {
 		/* pick a server to query */
-		server = afs_volume_pick_fileserver(vnode);
-		if (IS_ERR(server))
+		if (!afs_volume_pick_fileserver(&fc, vnode))
 			goto no_server;
 
-		_debug("USING SERVER: %pIS\n", &server->addr.transport);
-
-		ret = afs_fs_create(server, key, vnode, name, mode, newfid,
-				    newstatus, newcb, false);
+		fc.ac.error = afs_fs_create(&fc, key, vnode, name, mode, newfid,
+					    newstatus, newcb, false);
 
-	} while (!afs_volume_release_fileserver(vnode, server, ret));
+	} while (afs_iterate_fs_cursor(&fc, vnode));
 
 	/* adjust the flags */
-	if (ret == 0) {
-		afs_vnode_finalise_status_update(vnode, server);
-		*_server = server;
+	if (fc.ac.error == 0) {
+		afs_vnode_finalise_status_update(vnode, fc.server);
+		*_server = fc.server;
+		fc.server = NULL;
 	} else {
-		afs_vnode_status_update_failed(vnode, ret);
+		afs_vnode_status_update_failed(&fc, vnode);
 		*_server = NULL;
 	}
 
-	_leave(" = %d [cnt %d]", ret, vnode->update_cnt);
-	return ret;
+out:
+	return afs_end_fs_cursor(&fc, afs_v2net(vnode));
 
 no_server:
 	spin_lock(&vnode->lock);
 	vnode->update_cnt--;
 	ASSERTCMP(vnode->update_cnt, >=, 0);
 	spin_unlock(&vnode->lock);
-	_leave(" = %ld [cnt %d]", PTR_ERR(server), vnode->update_cnt);
-	return PTR_ERR(server);
+	goto out;
 }
 
 /*
@@ -331,8 +311,7 @@ no_server:
 int afs_vnode_remove(struct afs_vnode *vnode, struct key *key, const char *name,
 		     bool isdir)
 {
-	struct afs_server *server;
-	int ret;
+	struct afs_fs_cursor fc;
 
 	_enter("%s{%x:%u.%u},%x,%s",
 	       vnode->volume->vlocation->vldb.name,
@@ -347,37 +326,31 @@ int afs_vnode_remove(struct afs_vnode *vnode, struct key *key, const char *name,
 	vnode->update_cnt++;
 	spin_unlock(&vnode->lock);
 
+	afs_init_fs_cursor(&fc, vnode);
 	do {
 		/* pick a server to query */
-		server = afs_volume_pick_fileserver(vnode);
-		if (IS_ERR(server))
+		if (!afs_volume_pick_fileserver(&fc, vnode))
 			goto no_server;
 
-		_debug("USING SERVER: %pIS\n", &server->addr.transport);
-
-		ret = afs_fs_remove(server, key, vnode, name, isdir,
-				    false);
+		fc.ac.error = afs_fs_remove(&fc, key, vnode, name, isdir, false);
 
-	} while (!afs_volume_release_fileserver(vnode, server, ret));
+	} while (afs_iterate_fs_cursor(&fc, vnode));
 
 	/* adjust the flags */
-	if (ret == 0) {
-		afs_vnode_finalise_status_update(vnode, server);
-		afs_put_server(afs_v2net(vnode), server);
-	} else {
-		afs_vnode_status_update_failed(vnode, ret);
-	}
+	if (fc.ac.error == 0)
+		afs_vnode_finalise_status_update(vnode, fc.server);
+	else
+		afs_vnode_status_update_failed(&fc, vnode);
 
-	_leave(" = %d [cnt %d]", ret, vnode->update_cnt);
-	return ret;
+out:
+	return afs_end_fs_cursor(&fc, afs_v2net(vnode));
 
 no_server:
 	spin_lock(&vnode->lock);
 	vnode->update_cnt--;
 	ASSERTCMP(vnode->update_cnt, >=, 0);
 	spin_unlock(&vnode->lock);
-	_leave(" = %ld [cnt %d]", PTR_ERR(server), vnode->update_cnt);
-	return PTR_ERR(server);
+	goto out;
 }
 
 /*
@@ -386,8 +359,7 @@ no_server:
 int afs_vnode_link(struct afs_vnode *dvnode, struct afs_vnode *vnode,
 			  struct key *key, const char *name)
 {
-	struct afs_server *server;
-	int ret;
+	struct afs_fs_cursor fc;
 
 	_enter("%s{%x:%u.%u},%s{%x:%u.%u},%x,%s",
 	       dvnode->volume->vlocation->vldb.name,
@@ -409,31 +381,27 @@ int afs_vnode_link(struct afs_vnode *dvnode, struct afs_vnode *vnode,
 	dvnode->update_cnt++;
 	spin_unlock(&dvnode->lock);
 
+	afs_init_fs_cursor(&fc, vnode);
 	do {
 		/* pick a server to query */
-		server = afs_volume_pick_fileserver(dvnode);
-		if (IS_ERR(server))
+		if (!afs_volume_pick_fileserver(&fc, dvnode))
 			goto no_server;
 
-		_debug("USING SERVER: %pIS\n", &server->addr.transport);
+		fc.ac.error = afs_fs_link(&fc, key, dvnode, vnode, name, false);
 
-		ret = afs_fs_link(server, key, dvnode, vnode, name,
-				  false);
-
-	} while (!afs_volume_release_fileserver(dvnode, server, ret));
+	} while (afs_iterate_fs_cursor(&fc, dvnode));
 
 	/* adjust the flags */
-	if (ret == 0) {
-		afs_vnode_finalise_status_update(vnode, server);
-		afs_vnode_finalise_status_update(dvnode, server);
-		afs_put_server(afs_v2net(dvnode), server);
+	if (fc.ac.error == 0) {
+		afs_vnode_finalise_status_update(vnode, fc.server);
+		afs_vnode_finalise_status_update(dvnode, fc.server);
 	} else {
-		afs_vnode_status_update_failed(vnode, ret);
-		afs_vnode_status_update_failed(dvnode, ret);
+		afs_vnode_status_update_failed(&fc, vnode);
+		afs_vnode_status_update_failed(&fc, dvnode);
 	}
 
-	_leave(" = %d [cnt %d]", ret, vnode->update_cnt);
-	return ret;
+out:
+	return afs_end_fs_cursor(&fc, afs_v2net(vnode));
 
 no_server:
 	spin_lock(&vnode->lock);
@@ -444,8 +412,7 @@ no_server:
 	dvnode->update_cnt--;
 	ASSERTCMP(dvnode->update_cnt, >=, 0);
 	spin_unlock(&dvnode->lock);
-	_leave(" = %ld [cnt %d]", PTR_ERR(server), vnode->update_cnt);
-	return PTR_ERR(server);
+	goto out;
 }
 
 /*
@@ -457,8 +424,7 @@ int afs_vnode_symlink(struct afs_vnode *vnode, struct key *key,
 		      struct afs_file_status *newstatus,
 		      struct afs_server **_server)
 {
-	struct afs_server *server;
-	int ret;
+	struct afs_fs_cursor fc;
 
 	_enter("%s{%x:%u.%u},%x,%s,%s,,,",
 	       vnode->volume->vlocation->vldb.name,
@@ -473,38 +439,37 @@ int afs_vnode_symlink(struct afs_vnode *vnode, struct key *key,
 	vnode->update_cnt++;
 	spin_unlock(&vnode->lock);
 
+	afs_init_fs_cursor(&fc, vnode);
 	do {
 		/* pick a server to query */
-		server = afs_volume_pick_fileserver(vnode);
-		if (IS_ERR(server))
+		if (!afs_volume_pick_fileserver(&fc, vnode))
 			goto no_server;
 
-		_debug("USING SERVER: %pIS\n", &server->addr.transport);
+		fc.ac.error = afs_fs_symlink(&fc, key, vnode, name, content,
+					     newfid, newstatus, false);
 
-		ret = afs_fs_symlink(server, key, vnode, name, content,
-				     newfid, newstatus, false);
-
-	} while (!afs_volume_release_fileserver(vnode, server, ret));
+	} while (afs_iterate_fs_cursor(&fc, vnode));
 
 	/* adjust the flags */
-	if (ret == 0) {
-		afs_vnode_finalise_status_update(vnode, server);
-		*_server = server;
+	if (fc.ac.error == 0) {
+		afs_vnode_finalise_status_update(vnode, fc.server);
+		*_server = fc.server;
+		fc.server = NULL;
 	} else {
-		afs_vnode_status_update_failed(vnode, ret);
+		afs_vnode_status_update_failed(&fc, vnode);
 		*_server = NULL;
 	}
 
-	_leave(" = %d [cnt %d]", ret, vnode->update_cnt);
-	return ret;
+out:
+	return afs_end_fs_cursor(&fc, afs_v2net(vnode));
 
 no_server:
 	spin_lock(&vnode->lock);
 	vnode->update_cnt--;
 	ASSERTCMP(vnode->update_cnt, >=, 0);
 	spin_unlock(&vnode->lock);
-	_leave(" = %ld [cnt %d]", PTR_ERR(server), vnode->update_cnt);
-	return PTR_ERR(server);
+	*_server = NULL;
+	goto out;
 }
 
 /*
@@ -516,8 +481,7 @@ int afs_vnode_rename(struct afs_vnode *orig_dvnode,
 		     const char *orig_name,
 		     const char *new_name)
 {
-	struct afs_server *server;
-	int ret;
+	struct afs_fs_cursor fc;
 
 	_enter("%s{%x:%u.%u},%s{%u,%u,%u},%x,%s,%s",
 	       orig_dvnode->volume->vlocation->vldb.name,
@@ -543,33 +507,30 @@ int afs_vnode_rename(struct afs_vnode *orig_dvnode,
 		spin_unlock(&new_dvnode->lock);
 	}
 
+	afs_init_fs_cursor(&fc, orig_dvnode);
 	do {
 		/* pick a server to query */
-		server = afs_volume_pick_fileserver(orig_dvnode);
-		if (IS_ERR(server))
+		if (!afs_volume_pick_fileserver(&fc, orig_dvnode))
 			goto no_server;
 
-		_debug("USING SERVER: %pIS\n", &server->addr.transport);
-
-		ret = afs_fs_rename(server, key, orig_dvnode, orig_name,
-				    new_dvnode, new_name, false);
+		fc.ac.error = afs_fs_rename(&fc, key, orig_dvnode, orig_name,
+					    new_dvnode, new_name, false);
 
-	} while (!afs_volume_release_fileserver(orig_dvnode, server, ret));
+	} while (afs_iterate_fs_cursor(&fc, orig_dvnode));
 
 	/* adjust the flags */
-	if (ret == 0) {
-		afs_vnode_finalise_status_update(orig_dvnode, server);
+	if (fc.ac.error == 0) {
+		afs_vnode_finalise_status_update(orig_dvnode, fc.server);
 		if (new_dvnode != orig_dvnode)
-			afs_vnode_finalise_status_update(new_dvnode, server);
-		afs_put_server(afs_v2net(orig_dvnode), server);
+			afs_vnode_finalise_status_update(new_dvnode, fc.server);
 	} else {
-		afs_vnode_status_update_failed(orig_dvnode, ret);
+		afs_vnode_status_update_failed(&fc, orig_dvnode);
 		if (new_dvnode != orig_dvnode)
-			afs_vnode_status_update_failed(new_dvnode, ret);
+			afs_vnode_status_update_failed(&fc, new_dvnode);
 	}
 
-	_leave(" = %d [cnt %d]", ret, orig_dvnode->update_cnt);
-	return ret;
+out:
+	return afs_end_fs_cursor(&fc, afs_v2net(orig_dvnode));
 
 no_server:
 	spin_lock(&orig_dvnode->lock);
@@ -582,8 +543,7 @@ no_server:
 		ASSERTCMP(new_dvnode->update_cnt, >=, 0);
 		spin_unlock(&new_dvnode->lock);
 	}
-	_leave(" = %ld [cnt %d]", PTR_ERR(server), orig_dvnode->update_cnt);
-	return PTR_ERR(server);
+	goto out;
 }
 
 /*
@@ -592,9 +552,8 @@ no_server:
 int afs_vnode_store_data(struct afs_writeback *wb, pgoff_t first, pgoff_t last,
 			 unsigned offset, unsigned to)
 {
-	struct afs_server *server;
+	struct afs_fs_cursor fc;
 	struct afs_vnode *vnode = wb->vnode;
-	int ret;
 
 	_enter("%s{%x:%u.%u},%x,%lx,%lx,%x,%x",
 	       vnode->volume->vlocation->vldb.name,
@@ -609,36 +568,33 @@ int afs_vnode_store_data(struct afs_writeback *wb, pgoff_t first, pgoff_t last,
 	vnode->update_cnt++;
 	spin_unlock(&vnode->lock);
 
+	afs_init_fs_cursor(&fc, vnode);
 	do {
 		/* pick a server to query */
-		server = afs_volume_pick_fileserver(vnode);
-		if (IS_ERR(server))
+		if (!afs_volume_pick_fileserver(&fc, vnode))
 			goto no_server;
 
-		_debug("USING SERVER: %pIS\n", &server->addr.transport);
-
-		ret = afs_fs_store_data(server, wb, first, last, offset, to,
-					false);
+		fc.ac.error = afs_fs_store_data(&fc, wb, first, last, offset, to,
+						false);
 
-	} while (!afs_volume_release_fileserver(vnode, server, ret));
+	} while (afs_iterate_fs_cursor(&fc, vnode));
 
 	/* adjust the flags */
-	if (ret == 0) {
-		afs_vnode_finalise_status_update(vnode, server);
-		afs_put_server(afs_v2net(vnode), server);
+	if (fc.ac.error == 0) {
+		afs_vnode_finalise_status_update(vnode, fc.server);
 	} else {
-		afs_vnode_status_update_failed(vnode, ret);
+		afs_vnode_status_update_failed(&fc, vnode);
 	}
 
-	_leave(" = %d", ret);
-	return ret;
+out:
+	return afs_end_fs_cursor(&fc, afs_v2net(vnode));
 
 no_server:
 	spin_lock(&vnode->lock);
 	vnode->update_cnt--;
 	ASSERTCMP(vnode->update_cnt, >=, 0);
 	spin_unlock(&vnode->lock);
-	return PTR_ERR(server);
+	goto out;
 }
 
 /*
@@ -647,8 +603,7 @@ no_server:
 int afs_vnode_setattr(struct afs_vnode *vnode, struct key *key,
 		      struct iattr *attr)
 {
-	struct afs_server *server;
-	int ret;
+	struct afs_fs_cursor fc;
 
 	_enter("%s{%x:%u.%u},%x",
 	       vnode->volume->vlocation->vldb.name,
@@ -662,35 +617,32 @@ int afs_vnode_setattr(struct afs_vnode *vnode, struct key *key,
 	vnode->update_cnt++;
 	spin_unlock(&vnode->lock);
 
+	afs_init_fs_cursor(&fc, vnode);
 	do {
 		/* pick a server to query */
-		server = afs_volume_pick_fileserver(vnode);
-		if (IS_ERR(server))
+		if (!afs_volume_pick_fileserver(&fc, vnode))
 			goto no_server;
 
-		_debug("USING SERVER: %pIS\n", &server->addr.transport);
-
-		ret = afs_fs_setattr(server, key, vnode, attr, false);
+		fc.ac.error = afs_fs_setattr(&fc, key, vnode, attr, false);
 
-	} while (!afs_volume_release_fileserver(vnode, server, ret));
+	} while (afs_iterate_fs_cursor(&fc, vnode));
 
 	/* adjust the flags */
-	if (ret == 0) {
-		afs_vnode_finalise_status_update(vnode, server);
-		afs_put_server(afs_v2net(vnode), server);
+	if (fc.ac.error == 0) {
+		afs_vnode_finalise_status_update(vnode, fc.server);
 	} else {
-		afs_vnode_status_update_failed(vnode, ret);
+		afs_vnode_status_update_failed(&fc, vnode);
 	}
 
-	_leave(" = %d", ret);
-	return ret;
+out:
+	return afs_end_fs_cursor(&fc, afs_v2net(vnode));
 
 no_server:
 	spin_lock(&vnode->lock);
 	vnode->update_cnt--;
 	ASSERTCMP(vnode->update_cnt, >=, 0);
 	spin_unlock(&vnode->lock);
-	return PTR_ERR(server);
+	goto out;
 }
 
 /*
@@ -699,8 +651,7 @@ no_server:
 int afs_vnode_get_volume_status(struct afs_vnode *vnode, struct key *key,
 				struct afs_volume_status *vs)
 {
-	struct afs_server *server;
-	int ret;
+	struct afs_fs_cursor fc;
 
 	_enter("%s{%x:%u.%u},%x,",
 	       vnode->volume->vlocation->vldb.name,
@@ -709,27 +660,17 @@ int afs_vnode_get_volume_status(struct afs_vnode *vnode, struct key *key,
 	       vnode->fid.unique,
 	       key_serial(key));
 
+	afs_init_fs_cursor(&fc, vnode);
 	do {
 		/* pick a server to query */
-		server = afs_volume_pick_fileserver(vnode);
-		if (IS_ERR(server))
-			goto no_server;
-
-		_debug("USING SERVER: %pIS\n", &server->addr.transport);
+		if (!afs_volume_pick_fileserver(&fc, vnode))
+			break;
 
-		ret = afs_fs_get_volume_status(server, key, vnode, vs, false);
+		fc.ac.error = afs_fs_get_volume_status(&fc, key, vnode, vs, false);
 
-	} while (!afs_volume_release_fileserver(vnode, server, ret));
+	} while (afs_iterate_fs_cursor(&fc, vnode));
 
-	/* adjust the flags */
-	if (ret == 0)
-		afs_put_server(afs_v2net(vnode), server);
-
-	_leave(" = %d", ret);
-	return ret;
-
-no_server:
-	return PTR_ERR(server);
+	return afs_end_fs_cursor(&fc, afs_v2net(vnode));
 }
 
 /*
@@ -738,8 +679,7 @@ no_server:
 int afs_vnode_set_lock(struct afs_vnode *vnode, struct key *key,
 		       afs_lock_type_t type)
 {
-	struct afs_server *server;
-	int ret;
+	struct afs_fs_cursor fc;
 
 	_enter("%s{%x:%u.%u},%x,%u",
 	       vnode->volume->vlocation->vldb.name,
@@ -748,27 +688,17 @@ int afs_vnode_set_lock(struct afs_vnode *vnode, struct key *key,
 	       vnode->fid.unique,
 	       key_serial(key), type);
 
+	afs_init_fs_cursor(&fc, vnode);
 	do {
 		/* pick a server to query */
-		server = afs_volume_pick_fileserver(vnode);
-		if (IS_ERR(server))
-			goto no_server;
+		if (!afs_volume_pick_fileserver(&fc, vnode))
+			break;
 
-		_debug("USING SERVER: %pIS\n", &server->addr.transport);
+		fc.ac.error = afs_fs_set_lock(&fc, key, vnode, type, false);
 
-		ret = afs_fs_set_lock(server, key, vnode, type, false);
+	} while (afs_iterate_fs_cursor(&fc, vnode));
 
-	} while (!afs_volume_release_fileserver(vnode, server, ret));
-
-	/* adjust the flags */
-	if (ret == 0)
-		afs_put_server(afs_v2net(vnode), server);
-
-	_leave(" = %d", ret);
-	return ret;
-
-no_server:
-	return PTR_ERR(server);
+	return afs_end_fs_cursor(&fc, afs_v2net(vnode));
 }
 
 /*
@@ -776,7 +706,7 @@ no_server:
  */
 int afs_vnode_extend_lock(struct afs_vnode *vnode, struct key *key)
 {
-	struct afs_server *server;
+	struct afs_fs_cursor fc;
 	int ret;
 
 	_enter("%s{%x:%u.%u},%x",
@@ -786,27 +716,13 @@ int afs_vnode_extend_lock(struct afs_vnode *vnode, struct key *key)
 	       vnode->fid.unique,
 	       key_serial(key));
 
-	do {
-		/* pick a server to query */
-		server = afs_volume_pick_fileserver(vnode);
-		if (IS_ERR(server))
-			goto no_server;
-
-		_debug("USING SERVER: %pIS\n", &server->addr.transport);
+	ret = afs_set_fs_cursor(&fc, vnode);
+	if (ret < 0)
+		return ret;
 
-		ret = afs_fs_extend_lock(server, key, vnode, false);
+	fc.ac.error = afs_fs_extend_lock(&fc, key, vnode, false);
 
-	} while (!afs_volume_release_fileserver(vnode, server, ret));
-
-	/* adjust the flags */
-	if (ret == 0)
-		afs_put_server(afs_v2net(vnode), server);
-
-	_leave(" = %d", ret);
-	return ret;
-
-no_server:
-	return PTR_ERR(server);
+	return afs_end_fs_cursor(&fc, afs_v2net(vnode));
 }
 
 /*
@@ -814,7 +730,7 @@ no_server:
  */
 int afs_vnode_release_lock(struct afs_vnode *vnode, struct key *key)
 {
-	struct afs_server *server;
+	struct afs_fs_cursor fc;
 	int ret;
 
 	_enter("%s{%x:%u.%u},%x",
@@ -824,25 +740,11 @@ int afs_vnode_release_lock(struct afs_vnode *vnode, struct key *key)
 	       vnode->fid.unique,
 	       key_serial(key));
 
-	do {
-		/* pick a server to query */
-		server = afs_volume_pick_fileserver(vnode);
-		if (IS_ERR(server))
-			goto no_server;
-
-		_debug("USING SERVER: %pIS\n", &server->addr.transport);
+	ret = afs_set_fs_cursor(&fc, vnode);
+	if (ret < 0)
+		return ret;
 
-		ret = afs_fs_release_lock(server, key, vnode, false);
+	fc.ac.error = afs_fs_release_lock(&fc, key, vnode, false);
 
-	} while (!afs_volume_release_fileserver(vnode, server, ret));
-
-	/* adjust the flags */
-	if (ret == 0)
-		afs_put_server(afs_v2net(vnode), server);
-
-	_leave(" = %d", ret);
-	return ret;
-
-no_server:
-	return PTR_ERR(server);
+	return afs_end_fs_cursor(&fc, afs_v2net(vnode));
 }