btrfs: cleanup btrfs_rm_device() promote fs_devices pointer

[sfrench/cifs-2.6.git] / fs / afs / callback.c

diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index abd9a84f4e88a6dbded5eb02aa75e46a239a4c56..571437dcb252842578b92a6f3b5b60a574703b94 100644 (file)
--- 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,