drbd: device->ldev is not guaranteed on an D_ATTACHING disk
Some parts of the code assumed that get_ldev_if_state(device, D_ATTACHING)
is sufficient to access the ldev member of the device object. That was
wrong. ldev may not be there or might be freed at any time if the device
has a disk state of D_ATTACHING.
bm_rw()
Documented that drbd_bm_read() is only called from drbd_adm_attach.
drbd_bm_write() is only called when a reference is held, and it is
documented that a caller has to hold a reference before calling
drbd_bm_write()
drbd_bm_write_page()
Use get_ldev() instead of get_ldev_if_state(device, D_ATTACHING)
drbd_bmio_set_n_write()
No longer use get_ldev_if_state(device, D_ATTACHING). All callers
hold a reference to ldev now.
drbd_bmio_clear_n_write()
All callers where holding a reference of ldev anyways. Remove the
misleading get_ldev_if_state(device, D_ATTACHING)
drbd_reconsider_max_bio_size()
Removed the get_ldev_if_state(device, D_ATTACHING). All callers
now pass a struct drbd_backing_dev* when they have a proper
reference, or a NULL pointer.
Before this fix, the receiver could trigger a NULL pointer
deref when in drbd_reconsider_max_bio_size()
drbd_bump_write_ordering()
Used get_ldev_if_state(device, D_ATTACHING) with the wrong assumption.
Remove it, and allow the caller to pass in a struct drbd_backing_dev*
when the caller knows that accessing this bdev is safe.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index 3dbe9bd..20ec890 100644
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -245,7 +245,7 @@
D_DISKLESS,
D_ATTACHING, /* In the process of reading the meta-data */
D_FAILED, /* Becomes D_DISKLESS as soon as we told it the peer */
- /* when >= D_FAILED it is legal to access mdev->bc */
+ /* when >= D_FAILED it is legal to access mdev->ldev */
D_NEGOTIATING, /* Late attaching state, we need to talk to the peer */
D_INCONSISTENT,
D_OUTDATED,