Date: Sat, 12 Sep 2009 16:22:37 GMT From: Tim Bishop <tim@bishnet.net> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/138764: ZFS panic: "panic: dirtying snapshot!" Message-ID: <200909121622.n8CGMb7j085963@www.freebsd.org> Resent-Message-ID: <200909121630.n8CGU7pv080408@freefall.freebsd.org>
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>Number: 138764
>Category: kern
>Synopsis: ZFS panic: "panic: dirtying snapshot!"
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Sat Sep 12 16:30:07 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator: Tim Bishop
>Release: 8-STABLE (post BETA4)
>Organization:
>Environment:
FreeBSD aberfal.kent.ac.uk 8.0-BETA4 FreeBSD 8.0-BETA4 #23: Fri Sep 11 18:33:19 BST 2009 tdb@aberfal.kent.ac.uk:/usr/obj/usr/src/sys/ABERFAL i386
>Description:
I'm running with a ZFS root file system using GPT partitioning and gptzfsboot. I then started using ZFS snapshots by using the sysutils/freebsd-snapshot port. This port basically just runs "zfs snapshot" and does some housekeeping.
The first snapshot went fine (when the machine was quiet). The second (when the machine was doing a portupgrade) caused a panic. All I have on the console is:
panic: dirtying snapshot
I traced this down to:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dataset.c:1104
void
dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
{
dsl_pool_t *dp;
if (ds == NULL) /* this is the meta-objset */
return;
ASSERT(ds->ds_user_ptr != NULL);
if (ds->ds_phys->ds_next_snap_obj != 0)
panic("dirtying snapshot!");
dp = ds->ds_dir->dd_pool;
if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) {
/* up the hold count until we can be written out */
dmu_buf_add_ref(ds->ds_dbuf, ds);
}
}
I'm not sure what this means though.
Sadly I have no debugging enabled and no crash dump.
>How-To-Repeat:
Hard to say. Run ZFS root and do snapshots when the machine is busy? I've only seen it once.
>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted:
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