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path: root/drivers/block/drbd/drbd_state.c
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Diffstat (limited to 'drivers/block/drbd/drbd_state.c')
-rw-r--r--drivers/block/drbd/drbd_state.c48
1 files changed, 47 insertions, 1 deletions
diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index eea0c4aec978..0813c654c893 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -346,7 +346,7 @@ static enum drbd_role min_role(enum drbd_role role1, enum drbd_role role2)
enum drbd_role conn_highest_role(struct drbd_connection *connection)
{
- enum drbd_role role = R_UNKNOWN;
+ enum drbd_role role = R_SECONDARY;
struct drbd_peer_device *peer_device;
int vnr;
@@ -579,11 +579,14 @@ drbd_req_state(struct drbd_device *device, union drbd_state mask,
unsigned long flags;
union drbd_state os, ns;
enum drbd_state_rv rv;
+ void *buffer = NULL;
init_completion(&done);
if (f & CS_SERIALIZE)
mutex_lock(device->state_mutex);
+ if (f & CS_INHIBIT_MD_IO)
+ buffer = drbd_md_get_buffer(device, __func__);
spin_lock_irqsave(&device->resource->req_lock, flags);
os = drbd_read_state(device);
@@ -636,6 +639,8 @@ drbd_req_state(struct drbd_device *device, union drbd_state mask,
}
abort:
+ if (buffer)
+ drbd_md_put_buffer(device);
if (f & CS_SERIALIZE)
mutex_unlock(device->state_mutex);
@@ -664,6 +669,47 @@ _drbd_request_state(struct drbd_device *device, union drbd_state mask,
return rv;
}
+/*
+ * We grab drbd_md_get_buffer(), because we don't want to "fail" the disk while
+ * there is IO in-flight: the transition into D_FAILED for detach purposes
+ * may get misinterpreted as actual IO error in a confused endio function.
+ *
+ * We wrap it all into wait_event(), to retry in case the drbd_req_state()
+ * returns SS_IN_TRANSIENT_STATE.
+ *
+ * To avoid potential deadlock with e.g. the receiver thread trying to grab
+ * drbd_md_get_buffer() while trying to get out of the "transient state", we
+ * need to grab and release the meta data buffer inside of that wait_event loop.
+ */
+static enum drbd_state_rv
+request_detach(struct drbd_device *device)
+{
+ return drbd_req_state(device, NS(disk, D_FAILED),
+ CS_VERBOSE | CS_ORDERED | CS_INHIBIT_MD_IO);
+}
+
+enum drbd_state_rv
+drbd_request_detach_interruptible(struct drbd_device *device)
+{
+ enum drbd_state_rv rv;
+ int ret;
+
+ drbd_suspend_io(device); /* so no-one is stuck in drbd_al_begin_io */
+ wait_event_interruptible(device->state_wait,
+ (rv = request_detach(device)) != SS_IN_TRANSIENT_STATE);
+ drbd_resume_io(device);
+
+ ret = wait_event_interruptible(device->misc_wait,
+ device->state.disk != D_FAILED);
+
+ if (rv == SS_IS_DISKLESS)
+ rv = SS_NOTHING_TO_DO;
+ if (ret)
+ rv = ERR_INTR;
+
+ return rv;
+}
+
enum drbd_state_rv
_drbd_request_state_holding_state_mutex(struct drbd_device *device, union drbd_state mask,
union drbd_state val, enum chg_state_flags f)