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| author | Philipp Reisner <philipp.reisner@linbit.com> | 2011-01-11 17:42:17 +0100 |
|---|---|---|
| committer | Philipp Reisner <philipp.reisner@linbit.com> | 2011-03-10 11:45:32 +0100 |
| commit | 4a23f2649698272abcd9e0c9a992d65739f32792 (patch) | |
| tree | 3921ce5019d9d72befc48dbf14850c189bce5543 /drivers/block/drbd/drbd_int.h | |
| parent | 2b8a90b55533c66258a1ff0fb27b8cffa95665c4 (diff) | |
| download | lwn-4a23f2649698272abcd9e0c9a992d65739f32792.tar.gz lwn-4a23f2649698272abcd9e0c9a992d65739f32792.zip | |
drbd: Do not full sync if a P_SYNC_UUID packet gets lost
See also commit from 2009-08-15
"drbd_uuid_compare(): Do not full sync in case a P_SYNC_UUID packet gets lost."
We saw cases where the History UUIDs where not as expected. So the
detection of the special case did not trigger. With the sync UUID
no longer being a random number, but deducible from the previous
bitmap UUID, the detection of this special case becomes more
reliable.
The SyncUUID now is the previous bitmap UUID + 0x1000000000000.
Rule 5a:
Cs = H1p & H1p + Offset = Bp
Connection was lost before SyncUUID Packet came through.
Corrent (peer) UUIDs:
Bp = H1p
H1p = H2p
H2p = 0
Become Sync target.
Rule 7a:
Cp = H1s & H1s + Offset = Bs
Connection was lost before SyncUUID Packet came through.
Correct (own) UUIDs:
Bs = H1s
H1s = H2s
H2s = 0
Become Sync source.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Diffstat (limited to 'drivers/block/drbd/drbd_int.h')
| -rw-r--r-- | drivers/block/drbd/drbd_int.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index 84b4575fdf43..3c8eecd9666d 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -97,6 +97,7 @@ extern char usermode_helper[]; #define ID_SYNCER (-1ULL) #define ID_VACANT 0 #define is_syncer_block_id(id) ((id) == ID_SYNCER) +#define UUID_NEW_BM_OFFSET ((u64)0x0001000000000000ULL) struct drbd_conf; |