1 files changed, 61 insertions, 23 deletions

diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index abd9a84f4e88a..571437dcb2528 100644
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -23,36 +23,55 @@
 /*
  * 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;
 		}
 	}
@@ -72,13 +91,16 @@ again:
 		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 +110,14 @@ 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;
 }
 
@@ -171,13 +196,24 @@ static void afs_break_one_callback(struct afs_server *server,
 		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);
+		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);
+			}
 		}
 	}
 
@@ -195,6 +231,8 @@ 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,