[5.10,02/25] gfs2: Flag a withdraw if init_threads() fails

Message ID	20210415144413.242862151@linuxfoundation.org
State	New
Headers	show Return-Path: <stable-owner@kernel.org> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, stable@vger.kernel.org, Alexander Aring <aahringo@redhat.com>, Andrew Price <anprice@redhat.com>, Andreas Gruenbacher <agruenba@redhat.com>, Sasha Levin <sashal@kernel.org> Subject: [PATCH 5.10 02/25] gfs2: Flag a withdraw if init_threads() fails Date: Thu, 15 Apr 2021 16:47:56 +0200 Message-Id: <20210415144413.242862151@linuxfoundation.org> In-Reply-To: <20210415144413.165663182@linuxfoundation.org> References: <20210415144413.165663182@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	None \| expand [5.10,02/25] gfs2: Flag a withdraw if init_threads() fails [5.10,03/25] KVM: arm64: Hide system instruction access to Trace registers [5.10,04/25] KVM: arm64: Disable guest access to trace filter controls [5.10,05/25] drm/imx: imx-ldb: fix out of bounds array access warning [5.10,06/25] gfs2: report "already frozen/thawed" errors [5.10,07/25] ftrace: Check if pages were allocated before calling free_pages() [5.10,08/25] tools/kvm_stat: Add restart delay [5.10,09/25] drm/tegra: dc: Dont set PLL clock to 0Hz [5.10,10/25] gpu: host1x: Use different lock classes for each client [5.10,11/25] XArray: Fix splitting to non-zero orders [5.10,13/25] block: only update parent bi_status when bio fail [5.10,14/25] radix tree test suite: Register the main thread with the RCU library [5.10,15/25] idr test suite: Take RCU read lock in idr_find_test_1 [5.10,16/25] idr test suite: Create anchor before launching throbber [5.10,17/25] null_blk: fix command timeout completion handling [5.10,18/25] io_uring: dont mark S_ISBLK async work as unbounded [5.10,19/25] riscv,entry: fix misaligned base for excp_vect_table [5.10,20/25] block: dont ignore REQ_NOWAIT for direct IO [5.10,21/25] netfilter: x_tables: fix compat match/target pad out-of-bound write [5.10,22/25] perf map: Tighten snprintf() string precision to pass gcc check on some 32-bit arches [5.10,23/25] net: sfp: relax bitrate-derived mode check [5.10,24/25] net: sfp: cope with SFPs that set both LOS normal and LOS inverted [5.10,25/25] xen/events: fix setting irq affinity

Message ID

20210415144413.242862151@linuxfoundation.org

State

New

Headers

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Alexander Aring <aahringo@redhat.com>,
	Andrew Price <anprice@redhat.com>,
	Andreas Gruenbacher <agruenba@redhat.com>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10 02/25] gfs2: Flag a withdraw if init_threads() fails
Date: Thu, 15 Apr 2021 16:47:56 +0200
Message-Id: <20210415144413.242862151@linuxfoundation.org>
In-Reply-To: <20210415144413.165663182@linuxfoundation.org>
References: <20210415144413.165663182@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

Series

None | expand

Commit Message

Greg Kroah-Hartman April 15, 2021, 2:47 p.m. UTC

From: Andrew Price <anprice@redhat.com>

[ Upstream commit 62dd0f98a0e5668424270b47a0c2e973795faba7 ]

Interrupting mount with ^C quickly enough can cause the kthread_run()
calls in gfs2's init_threads() to fail and the error path leads to a
deadlock on the s_umount rwsem. The abridged chain of events is:

  [mount path]
  get_tree_bdev()
    sget_fc()
      alloc_super()
        down_write_nested(&s->s_umount, SINGLE_DEPTH_NESTING); [acquired]
    gfs2_fill_super()
      gfs2_make_fs_rw()
        init_threads()
          kthread_run()
            ( Interrupted )
      [Error path]
      gfs2_gl_hash_clear()
        flush_workqueue(glock_workqueue)
          wait_for_completion()

  [workqueue context]
  glock_work_func()
    run_queue()
      do_xmote()
        freeze_go_sync()
          freeze_super()
            down_write(&sb->s_umount) [deadlock]

In freeze_go_sync() there is a gfs2_withdrawn() check that we can use to
make sure freeze_super() is not called in the error path, so add a
gfs2_withdraw_delayed() call when init_threads() fails.

Ref: https://bugzilla.kernel.org/show_bug.cgi?id=212231

Reported-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/gfs2/super.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index ddd40c96f7a2..0581612dd91e 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -169,8 +169,10 @@  int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 	int error;
 
 	error = init_threads(sdp);
-	if (error)
+	if (error) {
+		gfs2_withdraw_delayed(sdp);
 		return error;
+	}
 
 	j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
 	if (gfs2_withdrawn(sdp)) {

[5.10,02/25] gfs2: Flag a withdraw if init_threads() fails

Commit Message

Patch