afs: Overhaul volume and server record caching and fileserver rotation

The current code assumes that volumes and servers are per-cell and are
never shared, but this is not enforced, and, indeed, public cells do exist
that are aliases of each other.  Further, an organisation can, say, set up
a public cell and a private cell with overlapping, but not identical, sets
of servers.  The difference is purely in the database attached to the VL
servers.

The current code will malfunction if it sees a server in two cells as it
assumes global address -> server record mappings and that each server is in
just one cell.

Further, each server may have multiple addresses - and may have addresses
of different families (IPv4 and IPv6, say).

To this end, the following structural changes are made:

 (1) Server record management is overhauled:

     (a) Server records are made independent of cell.  The namespace keeps
     	 track of them, volume records have lists of them and each vnode
     	 has a server on which its callback interest currently resides.

     (b) The cell record no longer keeps a list of servers known to be in
     	 that cell.

     (c) The server records are now kept in a flat list because there's no
     	 single address to sort on.

     (d) Server records are now keyed by their UUID within the namespace.

     (e) The addresses for a server are obtained with the VL.GetAddrsU
     	 rather than with VL.GetEntryByName, using the server's UUID as a
     	 parameter.

     (f) Cached server records are garbage collected after a period of
     	 non-use and are counted out of existence before purging is allowed
     	 to complete.  This protects the work functions against rmmod.

     (g) The servers list is now in /proc/fs/afs/servers.

 (2) Volume record management is overhauled:

     (a) An RCU-replaceable server list is introduced.  This tracks both
     	 servers and their coresponding callback interests.

     (b) The superblock is now keyed on cell record and numeric volume ID.

     (c) The volume record is now tied to the superblock which mounts it,
     	 and is activated when mounted and deactivated when unmounted.
     	 This makes it easier to handle the cache cookie without causing a
     	 double-use in fscache.

     (d) The volume record is loaded from the VLDB using VL.GetEntryByNameU
     	 to get the server UUID list.

     (e) The volume name is updated if it is seen to have changed when the
     	 volume is updated (the update is keyed on the volume ID).

 (3) The vlocation record is got rid of and VLDB records are no longer
     cached.  Sufficient information is stored in the volume record, though
     an update to a volume record is now no longer shared between related
     volumes (volumes come in bundles of three: R/W, R/O and backup).

and the following procedural changes are made:

 (1) The fileserver cursor introduced previously is now fleshed out and
     used to iterate over fileservers and their addresses.

 (2) Volume status is checked during iteration, and the server list is
     replaced if a change is detected.

 (3) Server status is checked during iteration, and the address list is
     replaced if a change is detected.

 (4) The abort code is saved into the address list cursor and -ECONNABORTED
     returned in afs_make_call() if a remote abort happened rather than
     translating the abort into an error message.  This allows actions to
     be taken depending on the abort code more easily.

     (a) If a VMOVED abort is seen then this is handled by rechecking the
     	 volume and restarting the iteration.

     (b) If a VBUSY, VRESTARTING or VSALVAGING abort is seen then this is
         handled by sleeping for a short period and retrying and/or trying
         other servers that might serve that volume.  A message is also
         displayed once until the condition has cleared.

     (c) If a VOFFLINE abort is seen, then this is handled as VBUSY for the
     	 moment.

     (d) If a VNOVOL abort is seen, the volume is rechecked in the VLDB to
     	 see if it has been deleted; if not, the fileserver is probably
     	 indicating that the volume couldn't be attached and needs
     	 salvaging.

     (e) If statfs() sees one of these aborts, it does not sleep, but
     	 rather returns an error, so as not to block the umount program.

 (5) The fileserver iteration functions in vnode.c are now merged into
     their callers and more heavily macroised around the cursor.  vnode.c
     is removed.

 (6) Operations on a particular vnode are serialised on that vnode because
     the server will lock that vnode whilst it operates on it, so a second
     op sent will just have to wait.

 (7) Fileservers are probed with FS.GetCapabilities before being used.
     This is where service upgrade will be done.

 (8) A callback interest on a fileserver is set up before an FS operation
     is performed and passed through to afs_make_call() so that it can be
     set on the vnode if the operation returns a callback.  The callback
     interest is passed through to afs_iget() also so that it can be set
     there too.

In general, record updating is done on an as-needed basis when we try to
access servers, volumes or vnodes rather than offloading it to work items
and special threads.

Notes:

 (1) Pre AFS-3.4 servers are no longer supported, though this can be added
     back if necessary (AFS-3.4 was released in 1998).

 (2) VBUSY is retried forever for the moment at intervals of 1s.

 (3) /proc/fs/afs/<cell>/servers no longer exists.

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

1 files changed, 206 insertions, 141 deletions

diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 6614d0a..72ff367 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -22,9 +22,9 @@
  */
 static u8 afs_discard_buffer[64];
 
-static inline void afs_use_fs_server(struct afs_call *call, struct afs_server *server)
+static inline void afs_use_fs_server(struct afs_call *call, struct afs_cb_interest *cbi)
 {
-	call->server = afs_get_server(server);
+	call->cbi = afs_get_cb_interest(cbi);
 }
 
 /*
@@ -56,7 +56,8 @@ static void xdr_decode_AFSFetchStatus(const __be32 **_bp,
 	kuid_t owner;
 	kgid_t group;
 
-	write_seqlock(&vnode->cb_lock);
+	if (vnode)
+		write_seqlock(&vnode->cb_lock);
 
 #define EXTRACT(DST)				\
 	do {					\
@@ -141,7 +142,8 @@ static void xdr_decode_AFSFetchStatus(const __be32 **_bp,
 		status->data_version = data_version;
 	}
 
-	write_sequnlock(&vnode->cb_lock);
+	if (vnode)
+		write_sequnlock(&vnode->cb_lock);
 }
 
 /*
@@ -151,22 +153,29 @@ static void xdr_decode_AFSCallBack(struct afs_call *call,
 				   struct afs_vnode *vnode,
 				   const __be32 **_bp)
 {
+	struct afs_cb_interest *old, *cbi = call->cbi;
 	const __be32 *bp = *_bp;
 	u32 cb_expiry;
 
 	write_seqlock(&vnode->cb_lock);
 
-	if (call->cb_break == (vnode->cb_break + call->server->cb_s_break)) {
+	if (call->cb_break == (vnode->cb_break + cbi->server->cb_s_break)) {
 		vnode->cb_version	= ntohl(*bp++);
 		cb_expiry		= ntohl(*bp++);
 		vnode->cb_type		= ntohl(*bp++);
 		vnode->cb_expires_at	= cb_expiry + ktime_get_real_seconds();
+		old = vnode->cb_interest;
+		if (old != call->cbi) {
+			vnode->cb_interest = cbi;
+			cbi = old;
+		}
 		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
 	} else {
 		bp += 3;
 	}
 
 	write_sequnlock(&vnode->cb_lock);
+	call->cbi = cbi;
 	*_bp = bp;
 }
 
@@ -297,24 +306,23 @@ static const struct afs_call_type afs_RXFSFetchStatus = {
 /*
  * fetch the status information for a file
  */
-int afs_fs_fetch_file_status(struct afs_fs_cursor *fc,
-			     struct key *key,
-			     struct afs_vnode *vnode,
-			     struct afs_volsync *volsync,
-			     bool async)
+int afs_fs_fetch_file_status(struct afs_fs_cursor *fc, struct afs_volsync *volsync)
 {
+	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	__be32 *bp;
 
 	_enter(",%x,{%x:%u},,",
-	       key_serial(key), vnode->fid.vid, vnode->fid.vnode);
+	       key_serial(fc->key), vnode->fid.vid, vnode->fid.vnode);
 
 	call = afs_alloc_flat_call(net, &afs_RXFSFetchStatus, 16, (21 + 3 + 6) * 4);
-	if (!call)
+	if (!call) {
+		fc->ac.error = -ENOMEM;
 		return -ENOMEM;
+	}
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = vnode;
 	call->reply[1] = volsync;
 
@@ -325,9 +333,9 @@ int afs_fs_fetch_file_status(struct afs_fs_cursor *fc,
 	bp[2] = htonl(vnode->fid.vnode);
 	bp[3] = htonl(vnode->fid.unique);
 
-	call->cb_break = vnode->cb_break + fc->server->cb_s_break;
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	call->cb_break = fc->cb_break;
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
@@ -502,12 +510,9 @@ static const struct afs_call_type afs_RXFSFetchData64 = {
 /*
  * fetch data from a very large file
  */
-static int afs_fs_fetch_data64(struct afs_fs_cursor *fc,
-			       struct key *key,
-			       struct afs_vnode *vnode,
-			       struct afs_read *req,
-			       bool async)
+static int afs_fs_fetch_data64(struct afs_fs_cursor *fc, struct afs_read *req)
 {
+	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	__be32 *bp;
@@ -518,7 +523,7 @@ static int afs_fs_fetch_data64(struct afs_fs_cursor *fc,
 	if (!call)
 		return -ENOMEM;
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = vnode;
 	call->reply[1] = NULL; /* volsync */
 	call->reply[2] = req;
@@ -536,20 +541,17 @@ static int afs_fs_fetch_data64(struct afs_fs_cursor *fc,
 	bp[7] = htonl(lower_32_bits(req->len));
 
 	atomic_inc(&req->usage);
-	call->cb_break = vnode->cb_break + fc->server->cb_s_break;
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	call->cb_break = fc->cb_break;
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
  * fetch data from a file
  */
-int afs_fs_fetch_data(struct afs_fs_cursor *fc,
-		      struct key *key,
-		      struct afs_vnode *vnode,
-		      struct afs_read *req,
-		      bool async)
+int afs_fs_fetch_data(struct afs_fs_cursor *fc, struct afs_read *req)
 {
+	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	__be32 *bp;
@@ -557,7 +559,7 @@ int afs_fs_fetch_data(struct afs_fs_cursor *fc,
 	if (upper_32_bits(req->pos) ||
 	    upper_32_bits(req->len) ||
 	    upper_32_bits(req->pos + req->len))
-		return afs_fs_fetch_data64(fc, key, vnode, req, async);
+		return afs_fs_fetch_data64(fc, req);
 
 	_enter("");
 
@@ -565,7 +567,7 @@ int afs_fs_fetch_data(struct afs_fs_cursor *fc,
 	if (!call)
 		return -ENOMEM;
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = vnode;
 	call->reply[1] = NULL; /* volsync */
 	call->reply[2] = req;
@@ -581,9 +583,9 @@ int afs_fs_fetch_data(struct afs_fs_cursor *fc,
 	bp[5] = htonl(lower_32_bits(req->len));
 
 	atomic_inc(&req->usage);
-	call->cb_break = vnode->cb_break + fc->server->cb_s_break;
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	call->cb_break = fc->cb_break;
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
@@ -626,15 +628,13 @@ static const struct afs_call_type afs_RXFSCreateXXXX = {
  * create a file or make a directory
  */
 int afs_fs_create(struct afs_fs_cursor *fc,
-		  struct key *key,
-		  struct afs_vnode *vnode,
 		  const char *name,
 		  umode_t mode,
 		  struct afs_fid *newfid,
 		  struct afs_file_status *newstatus,
-		  struct afs_callback *newcb,
-		  bool async)
+		  struct afs_callback *newcb)
 {
+	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	size_t namesz, reqsz, padsz;
@@ -651,7 +651,7 @@ int afs_fs_create(struct afs_fs_cursor *fc,
 	if (!call)
 		return -ENOMEM;
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = vnode;
 	call->reply[1] = newfid;
 	call->reply[2] = newstatus;
@@ -677,8 +677,8 @@ int afs_fs_create(struct afs_fs_cursor *fc,
 	*bp++ = htonl(mode & S_IALLUGO); /* unix mode */
 	*bp++ = 0; /* segment size */
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
@@ -717,13 +717,9 @@ static const struct afs_call_type afs_RXFSRemoveXXXX = {
 /*
  * remove a file or directory
  */
-int afs_fs_remove(struct afs_fs_cursor *fc,
-		  struct key *key,
-		  struct afs_vnode *vnode,
-		  const char *name,
-		  bool isdir,
-		  bool async)
+int afs_fs_remove(struct afs_fs_cursor *fc, const char *name, bool isdir)
 {
+	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	size_t namesz, reqsz, padsz;
@@ -739,7 +735,7 @@ int afs_fs_remove(struct afs_fs_cursor *fc,
 	if (!call)
 		return -ENOMEM;
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = vnode;
 
 	/* marshall the parameters */
@@ -756,8 +752,8 @@ int afs_fs_remove(struct afs_fs_cursor *fc,
 		bp = (void *) bp + padsz;
 	}
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
@@ -797,13 +793,10 @@ static const struct afs_call_type afs_RXFSLink = {
 /*
  * make a hard link
  */
-int afs_fs_link(struct afs_fs_cursor *fc,
-		struct key *key,
-		struct afs_vnode *dvnode,
-		struct afs_vnode *vnode,
-		const char *name,
-		bool async)
+int afs_fs_link(struct afs_fs_cursor *fc, struct afs_vnode *vnode,
+		const char *name)
 {
+	struct afs_vnode *dvnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	size_t namesz, reqsz, padsz;
@@ -819,7 +812,7 @@ int afs_fs_link(struct afs_fs_cursor *fc,
 	if (!call)
 		return -ENOMEM;
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = dvnode;
 	call->reply[1] = vnode;
 
@@ -840,8 +833,8 @@ int afs_fs_link(struct afs_fs_cursor *fc,
 	*bp++ = htonl(vnode->fid.vnode);
 	*bp++ = htonl(vnode->fid.unique);
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
@@ -883,14 +876,12 @@ static const struct afs_call_type afs_RXFSSymlink = {
  * create a symbolic link
  */
 int afs_fs_symlink(struct afs_fs_cursor *fc,
-		   struct key *key,
-		   struct afs_vnode *vnode,
 		   const char *name,
 		   const char *contents,
 		   struct afs_fid *newfid,
-		   struct afs_file_status *newstatus,
-		   bool async)
+		   struct afs_file_status *newstatus)
 {
+	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	size_t namesz, reqsz, padsz, c_namesz, c_padsz;
@@ -911,7 +902,7 @@ int afs_fs_symlink(struct afs_fs_cursor *fc,
 	if (!call)
 		return -ENOMEM;
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = vnode;
 	call->reply[1] = newfid;
 	call->reply[2] = newstatus;
@@ -943,8 +934,8 @@ int afs_fs_symlink(struct afs_fs_cursor *fc,
 	*bp++ = htonl(S_IRWXUGO); /* unix mode */
 	*bp++ = 0; /* segment size */
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
@@ -987,13 +978,11 @@ static const struct afs_call_type afs_RXFSRename = {
  * create a symbolic link
  */
 int afs_fs_rename(struct afs_fs_cursor *fc,
-		  struct key *key,
-		  struct afs_vnode *orig_dvnode,
 		  const char *orig_name,
 		  struct afs_vnode *new_dvnode,
-		  const char *new_name,
-		  bool async)
+		  const char *new_name)
 {
+	struct afs_vnode *orig_dvnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(orig_dvnode);
 	size_t reqsz, o_namesz, o_padsz, n_namesz, n_padsz;
@@ -1016,7 +1005,7 @@ int afs_fs_rename(struct afs_fs_cursor *fc,
 	if (!call)
 		return -ENOMEM;
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = orig_dvnode;
 	call->reply[1] = new_dvnode;
 
@@ -1045,8 +1034,8 @@ int afs_fs_rename(struct afs_fs_cursor *fc,
 		bp = (void *) bp + n_padsz;
 	}
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
@@ -1098,8 +1087,7 @@ static int afs_fs_store_data64(struct afs_fs_cursor *fc,
 			       struct afs_writeback *wb,
 			       pgoff_t first, pgoff_t last,
 			       unsigned offset, unsigned to,
-			       loff_t size, loff_t pos, loff_t i_size,
-			       bool async)
+			       loff_t size, loff_t pos, loff_t i_size)
 {
 	struct afs_vnode *vnode = wb->vnode;
 	struct afs_call *call;
@@ -1147,8 +1135,7 @@ static int afs_fs_store_data64(struct afs_fs_cursor *fc,
 	*bp++ = htonl(i_size >> 32);
 	*bp++ = htonl((u32) i_size);
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
@@ -1156,8 +1143,7 @@ static int afs_fs_store_data64(struct afs_fs_cursor *fc,
  */
 int afs_fs_store_data(struct afs_fs_cursor *fc, struct afs_writeback *wb,
 		      pgoff_t first, pgoff_t last,
-		      unsigned offset, unsigned to,
-		      bool async)
+		      unsigned offset, unsigned to)
 {
 	struct afs_vnode *vnode = wb->vnode;
 	struct afs_call *call;
@@ -1184,7 +1170,7 @@ int afs_fs_store_data(struct afs_fs_cursor *fc, struct afs_writeback *wb,
 
 	if (pos >> 32 || i_size >> 32 || size >> 32 || (pos + size) >> 32)
 		return afs_fs_store_data64(fc, wb, first, last, offset, to,
-					   size, pos, i_size, async);
+					   size, pos, i_size);
 
 	call = afs_alloc_flat_call(net, &afs_RXFSStoreData,
 				   (4 + 6 + 3) * 4,
@@ -1221,8 +1207,8 @@ int afs_fs_store_data(struct afs_fs_cursor *fc, struct afs_writeback *wb,
 	*bp++ = htonl(size);
 	*bp++ = htonl(i_size);
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
@@ -1279,16 +1265,15 @@ static const struct afs_call_type afs_RXFSStoreData64_as_Status = {
  * set the attributes on a very large file, using FS.StoreData rather than
  * FS.StoreStatus so as to alter the file size also
  */
-static int afs_fs_setattr_size64(struct afs_fs_cursor *fc, struct key *key,
-				 struct afs_vnode *vnode, struct iattr *attr,
-				 bool async)
+static int afs_fs_setattr_size64(struct afs_fs_cursor *fc, struct iattr *attr)
 {
+	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	__be32 *bp;
 
 	_enter(",%x,{%x:%u},,",
-	       key_serial(key), vnode->fid.vid, vnode->fid.vnode);
+	       key_serial(fc->key), vnode->fid.vid, vnode->fid.vnode);
 
 	ASSERT(attr->ia_valid & ATTR_SIZE);
 
@@ -1298,7 +1283,7 @@ static int afs_fs_setattr_size64(struct afs_fs_cursor *fc, struct key *key,
 	if (!call)
 		return -ENOMEM;
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = vnode;
 	call->store_version = vnode->status.data_version + 1;
 	call->operation_ID = FSSTOREDATA;
@@ -1319,28 +1304,27 @@ static int afs_fs_setattr_size64(struct afs_fs_cursor *fc, struct key *key,
 	*bp++ = htonl(attr->ia_size >> 32);	/* new file length */
 	*bp++ = htonl((u32) attr->ia_size);
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
  * set the attributes on a file, using FS.StoreData rather than FS.StoreStatus
  * so as to alter the file size also
  */
-static int afs_fs_setattr_size(struct afs_fs_cursor *fc, struct key *key,
-			       struct afs_vnode *vnode, struct iattr *attr,
-			       bool async)
+static int afs_fs_setattr_size(struct afs_fs_cursor *fc, struct iattr *attr)
 {
+	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	__be32 *bp;
 
 	_enter(",%x,{%x:%u},,",
-	       key_serial(key), vnode->fid.vid, vnode->fid.vnode);
+	       key_serial(fc->key), vnode->fid.vid, vnode->fid.vnode);
 
 	ASSERT(attr->ia_valid & ATTR_SIZE);
 	if (attr->ia_size >> 32)
-		return afs_fs_setattr_size64(fc, key, vnode, attr, async);
+		return afs_fs_setattr_size64(fc, attr);
 
 	call = afs_alloc_flat_call(net, &afs_RXFSStoreData_as_Status,
 				   (4 + 6 + 3) * 4,
@@ -1348,7 +1332,7 @@ static int afs_fs_setattr_size(struct afs_fs_cursor *fc, struct key *key,
 	if (!call)
 		return -ENOMEM;
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = vnode;
 	call->store_version = vnode->status.data_version + 1;
 	call->operation_ID = FSSTOREDATA;
@@ -1366,27 +1350,26 @@ static int afs_fs_setattr_size(struct afs_fs_cursor *fc, struct key *key,
 	*bp++ = 0;				/* size of write */
 	*bp++ = htonl(attr->ia_size);		/* new file length */
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
  * set the attributes on a file, using FS.StoreData if there's a change in file
  * size, and FS.StoreStatus otherwise
  */
-int afs_fs_setattr(struct afs_fs_cursor *fc, struct key *key,
-		   struct afs_vnode *vnode, struct iattr *attr,
-		   bool async)
+int afs_fs_setattr(struct afs_fs_cursor *fc, struct iattr *attr)
 {
+	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	__be32 *bp;
 
 	if (attr->ia_valid & ATTR_SIZE)
-		return afs_fs_setattr_size(fc, key, vnode, attr, async);
+		return afs_fs_setattr_size(fc, attr);
 
 	_enter(",%x,{%x:%u},,",
-	       key_serial(key), vnode->fid.vid, vnode->fid.vnode);
+	       key_serial(fc->key), vnode->fid.vid, vnode->fid.vnode);
 
 	call = afs_alloc_flat_call(net, &afs_RXFSStoreStatus,
 				   (4 + 6) * 4,
@@ -1394,7 +1377,7 @@ int afs_fs_setattr(struct afs_fs_cursor *fc, struct key *key,
 	if (!call)
 		return -ENOMEM;
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = vnode;
 	call->operation_ID = FSSTORESTATUS;
 
@@ -1407,8 +1390,8 @@ int afs_fs_setattr(struct afs_fs_cursor *fc, struct key *key,
 
 	xdr_encode_AFS_StoreStatus(&bp, attr);
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
@@ -1606,11 +1589,9 @@ static const struct afs_call_type afs_RXFSGetVolumeStatus = {
  * fetch the status of a volume
  */
 int afs_fs_get_volume_status(struct afs_fs_cursor *fc,
-			     struct key *key,
-			     struct afs_vnode *vnode,
-			     struct afs_volume_status *vs,
-			     bool async)
+			     struct afs_volume_status *vs)
 {
+	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	__be32 *bp;
@@ -1628,7 +1609,7 @@ int afs_fs_get_volume_status(struct afs_fs_cursor *fc,
 		return -ENOMEM;
 	}
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = vnode;
 	call->reply[1] = vs;
 	call->reply[2] = tmpbuf;
@@ -1638,8 +1619,8 @@ int afs_fs_get_volume_status(struct afs_fs_cursor *fc,
 	bp[0] = htonl(FSGETVOLUMESTATUS);
 	bp[1] = htonl(vnode->fid.vid);
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
@@ -1692,14 +1673,11 @@ static const struct afs_call_type afs_RXFSReleaseLock = {
 };
 
 /*
- * get a lock on a file
+ * Set a lock on a file
  */
-int afs_fs_set_lock(struct afs_fs_cursor *fc,
-		    struct key *key,
-		    struct afs_vnode *vnode,
-		    afs_lock_type_t type,
-		    bool async)
+int afs_fs_set_lock(struct afs_fs_cursor *fc, afs_lock_type_t type)
 {
+	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	__be32 *bp;
@@ -1710,7 +1688,7 @@ int afs_fs_set_lock(struct afs_fs_cursor *fc,
 	if (!call)
 		return -ENOMEM;
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = vnode;
 
 	/* marshall the parameters */
@@ -1721,18 +1699,16 @@ int afs_fs_set_lock(struct afs_fs_cursor *fc,
 	*bp++ = htonl(vnode->fid.unique);
 	*bp++ = htonl(type);
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
  * extend a lock on a file
  */
-int afs_fs_extend_lock(struct afs_fs_cursor *fc,
-		       struct key *key,
-		       struct afs_vnode *vnode,
-		       bool async)
+int afs_fs_extend_lock(struct afs_fs_cursor *fc)
 {
+	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	__be32 *bp;
@@ -1743,7 +1719,7 @@ int afs_fs_extend_lock(struct afs_fs_cursor *fc,
 	if (!call)
 		return -ENOMEM;
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = vnode;
 
 	/* marshall the parameters */
@@ -1753,18 +1729,16 @@ int afs_fs_extend_lock(struct afs_fs_cursor *fc,
 	*bp++ = htonl(vnode->fid.vnode);
 	*bp++ = htonl(vnode->fid.unique);
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
  * release a lock on a file
  */
-int afs_fs_release_lock(struct afs_fs_cursor *fc,
-			struct key *key,
-			struct afs_vnode *vnode,
-			bool async)
+int afs_fs_release_lock(struct afs_fs_cursor *fc)
 {
+	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
 	__be32 *bp;
@@ -1775,7 +1749,7 @@ int afs_fs_release_lock(struct afs_fs_cursor *fc,
 	if (!call)
 		return -ENOMEM;
 
-	call->key = key;
+	call->key = fc->key;
 	call->reply[0] = vnode;
 
 	/* marshall the parameters */
@@ -1785,8 +1759,8 @@ int afs_fs_release_lock(struct afs_fs_cursor *fc,
 	*bp++ = htonl(vnode->fid.vnode);
 	*bp++ = htonl(vnode->fid.unique);
 
-	afs_use_fs_server(call, fc->server);
-	return afs_make_call(&fc->ac, call, GFP_NOFS, async);
+	afs_use_fs_server(call, fc->cbi);
+	return afs_make_call(&fc->ac, call, GFP_NOFS, false);
 }
 
 /*
@@ -1809,17 +1783,17 @@ static const struct afs_call_type afs_RXFSGiveUpAllCallBacks = {
 /*
  * Flush all the callbacks we have on a server.
  */
-int afs_fs_give_up_all_callbacks(struct afs_server *server,
+int afs_fs_give_up_all_callbacks(struct afs_net *net,
+				 struct afs_server *server,
 				 struct afs_addr_cursor *ac,
-				 struct key *key,
-				 bool async)
+				 struct key *key)
 {
 	struct afs_call *call;
 	__be32 *bp;
 
 	_enter("");
 
-	call = afs_alloc_flat_call(server->net, &afs_RXFSGiveUpAllCallBacks, 2 * 4, 0);
+	call = afs_alloc_flat_call(net, &afs_RXFSGiveUpAllCallBacks, 1 * 4, 0);
 	if (!call)
 		return -ENOMEM;
 
@@ -1830,5 +1804,96 @@ int afs_fs_give_up_all_callbacks(struct afs_server *server,
 	*bp++ = htonl(FSGIVEUPALLCALLBACKS);
 
 	/* Can't take a ref on server */
-	return afs_make_call(ac, call, GFP_NOFS, async);
+	return afs_make_call(ac, call, GFP_NOFS, false);
+}
+
+/*
+ * Deliver reply data to an FS.GetCapabilities operation.
+ */
+static int afs_deliver_fs_get_capabilities(struct afs_call *call)
+{
+	u32 count;
+	int ret;
+
+	_enter("{%u,%zu/%u}", call->unmarshall, call->offset, call->count);
+
+again:
+	switch (call->unmarshall) {
+	case 0:
+		call->offset = 0;
+		call->unmarshall++;
+
+		/* Extract the capabilities word count */
+	case 1:
+		ret = afs_extract_data(call, &call->tmp,
+				       1 * sizeof(__be32),
+				       true);
+		if (ret < 0)
+			return ret;
+
+		count = ntohl(call->tmp);
+
+		call->count = count;
+		call->count2 = count;
+		call->offset = 0;
+		call->unmarshall++;
+
+		/* Extract capabilities words */
+	case 2:
+		count = min(call->count, 16U);
+		ret = afs_extract_data(call, call->buffer,
+				       count * sizeof(__be32),
+				       call->count > 16);
+		if (ret < 0)
+			return ret;
+
+		/* TODO: Examine capabilities */
+
+		call->count -= count;
+		if (call->count > 0)
+			goto again;
+		call->offset = 0;
+		call->unmarshall++;
+		break;
+	}
+
+	_leave(" = 0 [done]");
+	return 0;
+}
+
+/*
+ * FS.GetCapabilities operation type
+ */
+static const struct afs_call_type afs_RXFSGetCapabilities = {
+	.name		= "FS.GetCapabilities",
+	.deliver	= afs_deliver_fs_get_capabilities,
+	.destructor	= afs_flat_call_destructor,
+};
+
+/*
+ * Probe a fileserver for the capabilities that it supports.  This can
+ * return up to 196 words.
+ */
+int afs_fs_get_capabilities(struct afs_net *net,
+			    struct afs_server *server,
+			    struct afs_addr_cursor *ac,
+			    struct key *key)
+{
+	struct afs_call *call;
+	__be32 *bp;
+
+	_enter("");
+
+	call = afs_alloc_flat_call(net, &afs_RXFSGetCapabilities, 1 * 4, 16 * 4);
+	if (!call)
+		return -ENOMEM;
+
+	call->key = key;
+
+	/* marshall the parameters */
+	bp = call->request;
+	*bp++ = htonl(FSGETCAPABILITIES);
+
+	/* Can't take a ref on server */
+	return afs_make_call(ac, call, GFP_NOFS, false);
 }