afs: Overhaul cell database management

Overhaul the way that the in-kernel AFS client keeps track of cells in the
following manner:

 (1) Cells are now held in an rbtree to make walking them quicker and RCU
     managed (though this is probably overkill).

 (2) Cells now have a manager work item that:

     (A) Looks after fetching and refreshing the VL server list.

     (B) Manages cell record lifetime, including initialising and
     	 destruction.

     (B) Manages cell record caching whereby threads are kept around for a
     	 certain time after last use and then destroyed.

     (C) Manages the FS-Cache index cookie for a cell.  It is not permitted
     	 for a cookie to be in use twice, so we have to be careful to not
     	 allow a new cell record to exist at the same time as an old record
     	 of the same name.

 (3) Each AFS network namespace is given a manager work item that manages
     the cells within it, maintaining a single timer to prod cells into
     updating their DNS records.

     This uses the reduce_timer() facility to make the timer expire at the
     soonest timed event that needs happening.

 (4) When a module is being unloaded, cells and cell managers are now
     counted out using dec_after_work() to make sure the module text is
     pinned until after the data structures have been cleaned up.

 (5) Each cell's VL server list is now protected by a seqlock rather than a
     semaphore.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/afs/xattr.c b/fs/afs/xattr.c
index 2830e4f48d85..e58e00ee9747 100644
--- a/fs/afs/xattr.c
+++ b/fs/afs/xattr.c
@@ -45,7 +45,7 @@ static int afs_xattr_get_cell(const struct xattr_handler *handler,
 	struct afs_cell *cell = vnode->volume->cell;
 	size_t namelen;
 
-	namelen = strlen(cell->name);
+	namelen = cell->name_len;
 	if (size == 0)
 		return namelen;
 	if (namelen > size)