drbd: Track the reasons to suspend IO in dedicated state bits

There are three ways to get IO suspended:

 * Loss of any access to data
 * Fence-peer-handler running
 * User requested to suspend IO

Track those in different bits, so that one condition clearing its
state bit does not interfere with the other two conditions.

Only when the user resumes IO he overrules all three bits.

The fact is hidden from the user, he sees only a single suspend
bit.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index 89718a39791e..5e72a5d3d48f 100644
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -232,13 +232,17 @@ union drbd_state {
                 unsigned conn:5 ;   /* 17/32     cstates */
                 unsigned disk:4 ;   /* 8/16      from D_DISKLESS to D_UP_TO_DATE */
                 unsigned pdsk:4 ;   /* 8/16      from D_DISKLESS to D_UP_TO_DATE */
-                unsigned susp:1 ;   /* 2/2       IO suspended  no/yes */
+                unsigned susp:1 ;   /* 2/2       IO suspended no/yes (by user) */
                 unsigned aftr_isp:1 ; /* isp .. imposed sync pause */
                 unsigned peer_isp:1 ;
                 unsigned user_isp:1 ;
-                unsigned _pad:11;   /* 0         unused */
+                unsigned susp_nod:1 ; /* IO suspended because no data */
+                unsigned susp_fen:1 ; /* IO suspended because fence peer handler runs*/
+                unsigned _pad:9;   /* 0  unused */
 #elif defined(__BIG_ENDIAN_BITFIELD)
-                unsigned _pad:11;   /* 0         unused */
+                unsigned _pad:9;
+                unsigned susp_fen:1 ;
+                unsigned susp_nod:1 ;
                 unsigned user_isp:1 ;
                 unsigned peer_isp:1 ;
                 unsigned aftr_isp:1 ; /* isp .. imposed sync pause */