* [PATCH] xfs: cancel tx on xfs_defer_finish() error during xattr set/remove
@ 2018-01-16 19:45 Brian Foster
2018-01-16 22:51 ` Darrick J. Wong
0 siblings, 1 reply; 2+ messages in thread
From: Brian Foster @ 2018-01-16 19:45 UTC (permalink / raw
To: linux-xfs; +Cc: Chris Dunlop
Chris Dunlop reports a problem where an xattr operation fails,
reports the following error to syslog and hangs during unmount:
================================================
[ BUG: lock held when returning to user space! ]
...
------------------------------------------------
<PID> is leaving the kernel with locks still held!
1 lock held by <PID>:
#0: (sb_internal){......}, at: [<ffffffffa07692a3>] xfs_trans_alloc+0xe3/0x130 [xfs]
The failure/shutdown occurs during deferred ops processing which
leads to an error return from xfs_defer_finish() via
xfs_attr_leaf_addname(). While the root cause of the failure is
unknown corruption, the cause of the subsequent BUG above and
unmount hang is failure to cancel the transaction before returning
to userspace.
The transaction is not cancelled because the out_defer_cancel error
handling paths in the xfs_attr_[leaf|node]_[add|remove]name()
functions clear args.trans without releasing the transaction. The
callers therefore lose the reference to the transaction and fail to
cancel it.
Since xfs_attr_[set|remove]() always cancel args.trans when != NULL
and xfs_defer_finish()->...->xfs_trans_roll() should always return
with a valid transaction, update the leaf/node xattr functions to
not reset args.trans in the error path responsible for cancelling
deferred ops.
Reported-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Brian Foster <bfoster@redhat.com>
---
fs/xfs/libxfs/xfs_attr.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index a76914db72ef..ce4a34a2751d 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -717,7 +717,6 @@ xfs_attr_leaf_addname(xfs_da_args_t *args)
return error;
out_defer_cancel:
xfs_defer_cancel(args->dfops);
- args->trans = NULL;
return error;
}
@@ -770,7 +769,6 @@ xfs_attr_leaf_removename(xfs_da_args_t *args)
return 0;
out_defer_cancel:
xfs_defer_cancel(args->dfops);
- args->trans = NULL;
return error;
}
@@ -1045,7 +1043,6 @@ xfs_attr_node_addname(xfs_da_args_t *args)
return retval;
out_defer_cancel:
xfs_defer_cancel(args->dfops);
- args->trans = NULL;
goto out;
}
@@ -1186,7 +1183,6 @@ xfs_attr_node_removename(xfs_da_args_t *args)
return error;
out_defer_cancel:
xfs_defer_cancel(args->dfops);
- args->trans = NULL;
goto out;
}
--
2.13.6
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] xfs: cancel tx on xfs_defer_finish() error during xattr set/remove
2018-01-16 19:45 [PATCH] xfs: cancel tx on xfs_defer_finish() error during xattr set/remove Brian Foster
@ 2018-01-16 22:51 ` Darrick J. Wong
0 siblings, 0 replies; 2+ messages in thread
From: Darrick J. Wong @ 2018-01-16 22:51 UTC (permalink / raw
To: Brian Foster; +Cc: linux-xfs, Chris Dunlop
On Tue, Jan 16, 2018 at 02:45:37PM -0500, Brian Foster wrote:
> Chris Dunlop reports a problem where an xattr operation fails,
> reports the following error to syslog and hangs during unmount:
>
> ================================================
> [ BUG: lock held when returning to user space! ]
> ...
> ------------------------------------------------
> <PID> is leaving the kernel with locks still held!
> 1 lock held by <PID>:
> #0: (sb_internal){......}, at: [<ffffffffa07692a3>] xfs_trans_alloc+0xe3/0x130 [xfs]
>
> The failure/shutdown occurs during deferred ops processing which
> leads to an error return from xfs_defer_finish() via
> xfs_attr_leaf_addname(). While the root cause of the failure is
> unknown corruption, the cause of the subsequent BUG above and
> unmount hang is failure to cancel the transaction before returning
> to userspace.
>
> The transaction is not cancelled because the out_defer_cancel error
> handling paths in the xfs_attr_[leaf|node]_[add|remove]name()
> functions clear args.trans without releasing the transaction. The
> callers therefore lose the reference to the transaction and fail to
> cancel it.
>
> Since xfs_attr_[set|remove]() always cancel args.trans when != NULL
> and xfs_defer_finish()->...->xfs_trans_roll() should always return
> with a valid transaction, update the leaf/node xattr functions to
> not reset args.trans in the error path responsible for cancelling
> deferred ops.
>
> Reported-by: Chris Dunlop <chris@onthe.net.au>
> Signed-off-by: Brian Foster <bfoster@redhat.com>
Looks ok, will test...
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> fs/xfs/libxfs/xfs_attr.c | 4 ----
> 1 file changed, 4 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
> index a76914db72ef..ce4a34a2751d 100644
> --- a/fs/xfs/libxfs/xfs_attr.c
> +++ b/fs/xfs/libxfs/xfs_attr.c
> @@ -717,7 +717,6 @@ xfs_attr_leaf_addname(xfs_da_args_t *args)
> return error;
> out_defer_cancel:
> xfs_defer_cancel(args->dfops);
> - args->trans = NULL;
> return error;
> }
>
> @@ -770,7 +769,6 @@ xfs_attr_leaf_removename(xfs_da_args_t *args)
> return 0;
> out_defer_cancel:
> xfs_defer_cancel(args->dfops);
> - args->trans = NULL;
> return error;
> }
>
> @@ -1045,7 +1043,6 @@ xfs_attr_node_addname(xfs_da_args_t *args)
> return retval;
> out_defer_cancel:
> xfs_defer_cancel(args->dfops);
> - args->trans = NULL;
> goto out;
> }
>
> @@ -1186,7 +1183,6 @@ xfs_attr_node_removename(xfs_da_args_t *args)
> return error;
> out_defer_cancel:
> xfs_defer_cancel(args->dfops);
> - args->trans = NULL;
> goto out;
> }
>
> --
> 2.13.6
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2018-01-16 22:51 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2018-01-16 19:45 [PATCH] xfs: cancel tx on xfs_defer_finish() error during xattr set/remove Brian Foster
2018-01-16 22:51 ` Darrick J. Wong
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.