1 files changed, 154 insertions, 40 deletions

diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index abd9a84f4e88..5f261fbf2182 100644
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -21,64 +21,136 @@
 #include "internal.h"
 
 /*
+ * Create volume and callback interests on a server.
+ */
+static struct afs_cb_interest *afs_create_interest(struct afs_server *server,
+						   struct afs_vnode *vnode)
+{
+	struct afs_vol_interest *new_vi, *vi;
+	struct afs_cb_interest *new;
+	struct hlist_node **pp;
+
+	new_vi = kzalloc(sizeof(struct afs_vol_interest), GFP_KERNEL);
+	if (!new_vi)
+		return NULL;
+
+	new = kzalloc(sizeof(struct afs_cb_interest), GFP_KERNEL);
+	if (!new) {
+		kfree(new_vi);
+		return NULL;
+	}
+
+	new_vi->usage = 1;
+	new_vi->vid = vnode->volume->vid;
+	INIT_HLIST_NODE(&new_vi->srv_link);
+	INIT_HLIST_HEAD(&new_vi->cb_interests);
+
+	refcount_set(&new->usage, 1);
+	new->sb = vnode->vfs_inode.i_sb;
+	new->vid = vnode->volume->vid;
+	new->server = afs_get_server(server);
+	INIT_HLIST_NODE(&new->cb_vlink);
+
+	write_lock(&server->cb_break_lock);
+
+	for (pp = &server->cb_volumes.first; *pp; pp = &(*pp)->next) {
+		vi = hlist_entry(*pp, struct afs_vol_interest, srv_link);
+		if (vi->vid < new_vi->vid)
+			continue;
+		if (vi->vid > new_vi->vid)
+			break;
+		vi->usage++;
+		goto found_vi;
+	}
+
+	new_vi->srv_link.pprev = pp;
+	new_vi->srv_link.next = *pp;
+	if (*pp)
+		(*pp)->pprev = &new_vi->srv_link.next;
+	*pp = &new_vi->srv_link;
+	vi = new_vi;
+	new_vi = NULL;
+found_vi:
+
+	new->vol_interest = vi;
+	hlist_add_head(&new->cb_vlink, &vi->cb_interests);
+
+	write_unlock(&server->cb_break_lock);
+	kfree(new_vi);
+	return new;
+}
+
+/*
  * Set up an interest-in-callbacks record for a volume on a server and
  * register it with the server.
- * - Called with volume->server_sem held.
+ * - Called with vnode->io_lock held.
  */
 int afs_register_server_cb_interest(struct afs_vnode *vnode,
-				    struct afs_server_entry *entry)
+				    struct afs_server_list *slist,
+				    unsigned int index)
 {
-	struct afs_cb_interest *cbi = entry->cb_interest, *vcbi, *new, *x;
+	struct afs_server_entry *entry = &slist->servers[index];
+	struct afs_cb_interest *cbi, *vcbi, *new, *old;
 	struct afs_server *server = entry->server;
 
 again:
+	if (vnode->cb_interest &&
+	    likely(vnode->cb_interest == entry->cb_interest))
+		return 0;
+
+	read_lock(&slist->lock);
+	cbi = afs_get_cb_interest(entry->cb_interest);
+	read_unlock(&slist->lock);
+
 	vcbi = vnode->cb_interest;
 	if (vcbi) {
-		if (vcbi == cbi)
+		if (vcbi == cbi) {
+			afs_put_cb_interest(afs_v2net(vnode), cbi);
 			return 0;
+		}
 
+		/* Use a new interest in the server list for the same server
+		 * rather than an old one that's still attached to a vnode.
+		 */
 		if (cbi && vcbi->server == cbi->server) {
 			write_seqlock(&vnode->cb_lock);
-			vnode->cb_interest = afs_get_cb_interest(cbi);
+			old = vnode->cb_interest;
+			vnode->cb_interest = cbi;
 			write_sequnlock(&vnode->cb_lock);
-			afs_put_cb_interest(afs_v2net(vnode), cbi);
+			afs_put_cb_interest(afs_v2net(vnode), old);
 			return 0;
 		}
 
+		/* Re-use the one attached to the vnode. */
 		if (!cbi && vcbi->server == server) {
-			afs_get_cb_interest(vcbi);
-			x = cmpxchg(&entry->cb_interest, cbi, vcbi);
-			if (x != cbi) {
-				cbi = x;
-				afs_put_cb_interest(afs_v2net(vnode), vcbi);
+			write_lock(&slist->lock);
+			if (entry->cb_interest) {
+				write_unlock(&slist->lock);
+				afs_put_cb_interest(afs_v2net(vnode), cbi);
 				goto again;
 			}
+
+			entry->cb_interest = cbi;
+			write_unlock(&slist->lock);
 			return 0;
 		}
 	}
 
 	if (!cbi) {
-		new = kzalloc(sizeof(struct afs_cb_interest), GFP_KERNEL);
+		new = afs_create_interest(server, vnode);
 		if (!new)
 			return -ENOMEM;
 
-		refcount_set(&new->usage, 1);
-		new->sb = vnode->vfs_inode.i_sb;
-		new->vid = vnode->volume->vid;
-		new->server = afs_get_server(server);
-		INIT_LIST_HEAD(&new->cb_link);
-
-		write_lock(&server->cb_break_lock);
-		list_add_tail(&new->cb_link, &server->cb_interests);
-		write_unlock(&server->cb_break_lock);
-
-		x = cmpxchg(&entry->cb_interest, cbi, new);
-		if (x == cbi) {
+		write_lock(&slist->lock);
+		if (!entry->cb_interest) {
+			entry->cb_interest = afs_get_cb_interest(new);
 			cbi = new;
+			new = NULL;
 		} else {
-			cbi = x;
-			afs_put_cb_interest(afs_v2net(vnode), new);
+			cbi = afs_get_cb_interest(entry->cb_interest);
 		}
+		write_unlock(&slist->lock);
+		afs_put_cb_interest(afs_v2net(vnode), new);
 	}
 
 	ASSERT(cbi);
@@ -88,11 +160,14 @@ again:
 	 */
 	write_seqlock(&vnode->cb_lock);
 
-	vnode->cb_interest = afs_get_cb_interest(cbi);
+	old = vnode->cb_interest;
+	vnode->cb_interest = cbi;
 	vnode->cb_s_break = cbi->server->cb_s_break;
+	vnode->cb_v_break = vnode->volume->cb_v_break;
 	clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
 
 	write_sequnlock(&vnode->cb_lock);
+	afs_put_cb_interest(afs_v2net(vnode), old);
 	return 0;
 }
 
@@ -101,11 +176,22 @@ again:
  */
 void afs_put_cb_interest(struct afs_net *net, struct afs_cb_interest *cbi)
 {
+	struct afs_vol_interest *vi;
+
 	if (cbi && refcount_dec_and_test(&cbi->usage)) {
-		if (!list_empty(&cbi->cb_link)) {
+		if (!hlist_unhashed(&cbi->cb_vlink)) {
 			write_lock(&cbi->server->cb_break_lock);
-			list_del_init(&cbi->cb_link);
+
+			hlist_del_init(&cbi->cb_vlink);
+			vi = cbi->vol_interest;
+			cbi->vol_interest = NULL;
+			if (--vi->usage == 0)
+				hlist_del(&vi->srv_link);
+			else
+				vi = NULL;
+
 			write_unlock(&cbi->server->cb_break_lock);
+			kfree(vi);
 			afs_put_server(net, cbi->server);
 		}
 		kfree(cbi);
@@ -157,30 +243,56 @@ void afs_break_callback(struct afs_vnode *vnode)
 static void afs_break_one_callback(struct afs_server *server,
 				   struct afs_fid *fid)
 {
+	struct afs_vol_interest *vi;
 	struct afs_cb_interest *cbi;
 	struct afs_iget_data data;
 	struct afs_vnode *vnode;
 	struct inode *inode;
 
 	read_lock(&server->cb_break_lock);
+	hlist_for_each_entry(vi, &server->cb_volumes, srv_link) {
+		if (vi->vid < fid->vid)
+			continue;
+		if (vi->vid > fid->vid) {
+			vi = NULL;
+			break;
+		}
+		//atomic_inc(&vi->usage);
+		break;
+	}
+
+	/* TODO: Find all matching volumes if we couldn't match the server and
+	 * break them anyway.
+	 */
+	if (!vi)
+		goto out;
 
 	/* Step through all interested superblocks.  There may be more than one
 	 * because of cell aliasing.
 	 */
-	list_for_each_entry(cbi, &server->cb_interests, cb_link) {
-		if (cbi->vid != fid->vid)
-			continue;
-
-		data.volume = NULL;
-		data.fid = *fid;
-		inode = ilookup5_nowait(cbi->sb, fid->vnode, afs_iget5_test, &data);
-		if (inode) {
-			vnode = AFS_FS_I(inode);
-			afs_break_callback(vnode);
-			iput(inode);
+	hlist_for_each_entry(cbi, &vi->cb_interests, cb_vlink) {
+		if (fid->vnode == 0 && fid->unique == 0) {
+			/* The callback break applies to an entire volume. */
+			struct afs_super_info *as = AFS_FS_S(cbi->sb);
+			struct afs_volume *volume = as->volume;
+
+			write_lock(&volume->cb_break_lock);
+			volume->cb_v_break++;
+			write_unlock(&volume->cb_break_lock);
+		} else {
+			data.volume = NULL;
+			data.fid = *fid;
+			inode = ilookup5_nowait(cbi->sb, fid->vnode,
+						afs_iget5_test, &data);
+			if (inode) {
+				vnode = AFS_FS_I(inode);
+				afs_break_callback(vnode);
+				iput(inode);
+			}
 		}
 	}
 
+out:
 	read_unlock(&server->cb_break_lock);
 }
 
@@ -195,6 +307,8 @@ void afs_break_callbacks(struct afs_server *server, size_t count,
 	ASSERT(server != NULL);
 	ASSERTCMP(count, <=, AFSCBMAX);
 
+	/* TODO: Sort the callback break list by volume ID */
+
 	for (; count > 0; callbacks++, count--) {
 		_debug("- Fid { vl=%08x n=%u u=%u }  CB { v=%u x=%u t=%u }",
 		       callbacks->fid.vid,