1 files changed, 61 insertions, 23 deletions

diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index abd9a84f4e88..571437dcb252 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,