afs: Fix key leak in afs_release() and afs_evict_inode()

Fix afs_release() to go through the cleanup part of the function if
FMODE_WRITE is set rather than exiting through vfs_fsync() (which skips the
cleanup).  The cleanup involves discarding the refs on the key used for
file ops and the writeback key record.

Also fix afs_evict_inode() to clean up any left over wb keys attached to
the inode/vnode when it is removed.

Fixes: 5a8132761609 ("afs: Do better accretion of small writes on newly created content")
Signed-off-by: David Howells <dhowells@redhat.com>

2 files changed, 5 insertions, 3 deletions

diff --git a/fs/afs/file.c b/fs/afs/file.c
index e8d6619890a9..b0a43e250a9b 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -170,11 +170,12 @@ int afs_release(struct inode *inode, struct file *file)
 {
         struct afs_vnode *vnode = AFS_FS_I(inode);
         struct afs_file *af = file->private_data;
+        int ret = 0;
 
         _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode);
 
         if ((file->f_mode & FMODE_WRITE))
-                return vfs_fsync(file, 0);
+                ret = vfs_fsync(file, 0);
 
         file->private_data = NULL;
         if (af->wb)
@@ -182,8 +183,8 @@ int afs_release(struct inode *inode, struct file *file)
         key_put(af->key);
         kfree(af);
         afs_prune_wb_keys(vnode);
-        _leave(" = 0");
-        return 0;
+        _leave(" = %d", ret);
+        return ret;
 }
 
 /*
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index c4652b42d545..f30aa5eacd39 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -573,6 +573,7 @@ void afs_evict_inode(struct inode *inode)
         }
 #endif
 
+        afs_prune_wb_keys(vnode);
         afs_put_permits(rcu_access_pointer(vnode->permit_cache));
         key_put(vnode->silly_key);
         vnode->silly_key = NULL;