lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ocfs2/dlm: Remove BUG_ON from migration in the rare case of a down node

Browse Source 
For migration, we are waiting for DLM_LOCK_RES_MIGRATING flag to be set
before sending DLM_MIG_LOCKRES_MSG message to the target. We are using
dlm_migration_can_proceed() for that purpose.  However, if the node is
down, dlm_migration_can_proceed() will also return "go ahead".  In this
rare case, the DLM_LOCK_RES_MIGRATING flag might not be set yet. Remove
the BUG_ON() that trips over this condition.

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
This commit is contained in:
Wengang Wang
2010-07-14 22:38:21 +08:00
committed by Joel Becker
parent f5e27b6ddf
commit a39953dd95
1 changed files with 14 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
fs/ocfs2/dlm/dlmmaster.c
View File

@@ -2808,14 +2808,8 @@ again:
mlog(0, "trying again...\n"); mlog(0, "trying again...\n");
goto again; goto again;
} }
/* now that we are sure the MIGRATING state is there, drop
* the unneded state which blocked threads trying to DIRTY */
spin_lock(&res->spinlock);
BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY));
BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING));
res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY;
spin_unlock(&res->spinlock);
ret = 0;
/* did the target go down or die? */ /* did the target go down or die? */
spin_lock(&dlm->spinlock); spin_lock(&dlm->spinlock);
if (!test_bit(target, dlm->domain_map)) { if (!test_bit(target, dlm->domain_map)) {
@@ -2825,10 +2819,22 @@ again:
} }
spin_unlock(&dlm->spinlock); spin_unlock(&dlm->spinlock);
/*
* if target is down, we need to clear DLM_LOCK_RES_BLOCK_DIRTY for
* another try; otherwise, we are sure the MIGRATING state is there,
* drop the unneded state which blocked threads trying to DIRTY
*/
spin_lock(&res->spinlock);
BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY));
res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY;
if (!ret)
BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING));
spin_unlock(&res->spinlock);
/* /*
* at this point: * at this point:
* *
* o the DLM_LOCK_RES_MIGRATING flag is set * o the DLM_LOCK_RES_MIGRATING flag is set if target not down
* o there are no pending asts on this lockres * o there are no pending asts on this lockres
* o all processes trying to reserve an ast on this * o all processes trying to reserve an ast on this
* lockres must wait for the MIGRATING flag to clear * lockres must wait for the MIGRATING flag to clear