afs: afs_write_end() should change i_size under the right lock

[ Upstream commit 1f32ef79897052ef7d3d154610d8d6af95abde83 ]

Fix afs_write_end() to change i_size under vnode->cb_lock rather than
->wb_lock so that it doesn't race with afs_vnode_commit_status() and
afs_getattr().

The ->wb_lock is only meant to guard access to ->wb_keys which isn't
accessed by that piece of code.

Fixes: 4343d00872 ("afs: Get rid of the afs_writeback record")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
David Howells 2020-06-12 23:58:51 +01:00 committed by Greg Kroah-Hartman
parent 08de5907c0
commit 2788511b09

View file

@ -188,11 +188,11 @@ int afs_write_end(struct file *file, struct address_space *mapping,
i_size = i_size_read(&vnode->vfs_inode);
if (maybe_i_size > i_size) {
spin_lock(&vnode->wb_lock);
write_seqlock(&vnode->cb_lock);
i_size = i_size_read(&vnode->vfs_inode);
if (maybe_i_size > i_size)
i_size_write(&vnode->vfs_inode, maybe_i_size);
spin_unlock(&vnode->wb_lock);
write_sequnlock(&vnode->cb_lock);
}
if (!PageUptodate(page)) {