[RFC PATCH 72/76] afs: Invoke fscache_resize_cookie() when handling ATTR_SIZE for setattr

[David Howells]

Invoke fscache_resize_cookie() to adjust the size of the backing cache
object when setattr is called with ATTR_SIZE.  This discards any data that
then lies beyond the revised EOF and frees up space.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

 fs/afs/inode.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 51e55bfadb54..c639de101065 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -847,6 +847,9 @@ static void afs_setattr_edit_file(struct afs_operation *op)
 
 		if (size < i_size)
 			truncate_pagecache(inode, size);
+		if (size != i_size)
+			fscache_resize_cookie(afs_vnode_cache(vp->vnode),
+					      vp->scb.status.size);
 	}
 }
 
@@ -889,6 +892,8 @@ int afs_setattr(struct dentry *dentry, struct iattr *attr)
 			attr->ia_valid &= ~ATTR_SIZE;
 	}
 
+	fscache_use_cookie(afs_vnode_cache(vnode), true);
+
 	/* flush any dirty data outstanding on a regular file */
 	if (S_ISREG(vnode->vfs_inode.i_mode))
 		filemap_write_and_wait(vnode->vfs_inode.i_mapping);
@@ -919,6 +924,7 @@ int afs_setattr(struct dentry *dentry, struct iattr *attr)
 
 out_unlock:
 	up_write(&vnode->validate_lock);
+	fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
 	_leave(" = %d", ret);
 	return ret;
 }