AFS: fix a couple of problems with unlinking AFS files

Fix a couple of problems with unlinking AFS files.

 (1) The parent directory wasn't being updated properly between unlink() and
     the following lookup().

     It seems that, for some reason, invalidate_remote_inode() wasn't
     discarding the directory contents correctly, so this patch calls
     invalidate_inode_pages2() instead on non-regular files.

 (2) afs_vnode_deleted_remotely() should handle vnodes that don't have a
     source server recorded without oopsing.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 31 insertions, 17 deletions

diff --git a/fs/afs/file.c b/fs/afs/file.c
index 3e25795e5a42..9c0e721d9fc2 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -236,7 +236,7 @@ static void afs_invalidatepage(struct page *page, unsigned long offset)
 {
         int ret = 1;
 
-        kenter("{%lu},%lu", page->index, offset);
+        _enter("{%lu},%lu", page->index, offset);
 
         BUG_ON(!PageLocked(page));
 
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 515a5d12d8fb..47f5fed7195d 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -209,11 +209,15 @@ bad_inode:
  */
 void afs_zap_data(struct afs_vnode *vnode)
 {
-        _enter("zap data {%x:%u}", vnode->fid.vid, vnode->fid.vnode);
+        _enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode);
 
         /* nuke all the non-dirty pages that aren't locked, mapped or being
-         * written back */
-        invalidate_remote_inode(&vnode->vfs_inode);
+         * written back in a regular file and completely discard the pages in a
+         * directory or symlink */
+        if (S_ISREG(vnode->vfs_inode.i_mode))
+                invalidate_remote_inode(&vnode->vfs_inode);
+        else
+                invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
 }
 
 /*
diff --git a/fs/afs/super.c b/fs/afs/super.c
index d24be334b608..422f532b9b62 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -488,6 +488,7 @@ static struct inode *afs_alloc_inode(struct super_block *sb)
         vnode->flags            = 1 << AFS_VNODE_UNSET;
         vnode->cb_promised      = false;
 
+        _leave(" = %p", &vnode->vfs_inode);
         return &vnode->vfs_inode;
 }
 
@@ -498,7 +499,7 @@ static void afs_destroy_inode(struct inode *inode)
 {
         struct afs_vnode *vnode = AFS_FS_I(inode);
 
-        _enter("{%lu}", inode->i_ino);
+        _enter("%p{%x:%u}", inode, vnode->fid.vid, vnode->fid.vnode);
 
         _debug("DESTROY INODE %p", inode);
 
diff --git a/fs/afs/vnode.c b/fs/afs/vnode.c
index ec814660209f..bea8bd9e7b2a 100644
--- a/fs/afs/vnode.c
+++ b/fs/afs/vnode.c
@@ -175,24 +175,33 @@ static void afs_vnode_deleted_remotely(struct afs_vnode *vnode)
 {
         struct afs_server *server;
 
+        _enter("{%p}", vnode->server);
+
         set_bit(AFS_VNODE_DELETED, &vnode->flags);
 
         server = vnode->server;
-        if (vnode->cb_promised) {
-                spin_lock(&server->cb_lock);
+        if (server) {
                 if (vnode->cb_promised) {
-                        rb_erase(&vnode->cb_promise, &server->cb_promises);
-                        vnode->cb_promised = false;
+                        spin_lock(&server->cb_lock);
+                        if (vnode->cb_promised) {
+                                rb_erase(&vnode->cb_promise,
+                                         &server->cb_promises);
+                                vnode->cb_promised = false;
+                        }
+                        spin_unlock(&server->cb_lock);
                 }
-                spin_unlock(&server->cb_lock);
-        }
 
-        spin_lock(&vnode->server->fs_lock);
-        rb_erase(&vnode->server_rb, &vnode->server->fs_vnodes);
-        spin_unlock(&vnode->server->fs_lock);
+                spin_lock(&server->fs_lock);
+                rb_erase(&vnode->server_rb, &server->fs_vnodes);
+                spin_unlock(&server->fs_lock);
 
-        vnode->server = NULL;
-        afs_put_server(server);
+                vnode->server = NULL;
+                afs_put_server(server);
+        } else {
+                ASSERT(!vnode->cb_promised);
+        }
+
+        _leave("");
 }
 
 /*
@@ -225,7 +234,7 @@ void afs_vnode_finalise_status_update(struct afs_vnode *vnode,
  */
 static void afs_vnode_status_update_failed(struct afs_vnode *vnode, int ret)
 {
-        _enter("%p,%d", vnode, ret);
+        _enter("{%x:%u},%d", vnode->fid.vid, vnode->fid.vnode, ret);
 
         spin_lock(&vnode->lock);