afs: Fix order-1 allocation in afs_do_lookup()

afs_do_lookup() will do an order-1 allocation to allocate status records if
there are more than 39 vnodes to stat.

Fix this by allocating an array of {status,callback} records for each vnode
we want to examine using vmalloc() if larger than a page.

This not only gets rid of the order-1 allocation, but makes it easier to
grow beyond 50 records for YFS servers.  It also allows us to move to
{status,callback} tuples for other calls too and makes it easier to lock
across the application of the status and the callback to the vnode.

Fixes: 5cf9dd55a0ec ("afs: Prospectively look up extra files when doing a single lookup")
Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/afs/afs.h b/fs/afs/afs.h
index 74913c707bba..8fa0dffff1cc 100644
--- a/fs/afs/afs.h
+++ b/fs/afs/afs.h
@@ -147,6 +147,12 @@ struct afs_file_status {
 	u32			abort_code;	/* Abort if bulk-fetching this failed */
 };
 
+struct afs_status_cb {
+	struct afs_file_status	status;
+	struct afs_callback	callback;
+	bool			have_cb;	/* True if cb record was retrieved */
+};
+
 /*
  * AFS file status change request
  */