From: Jiri Slaby <jslaby@suse.cz>
To: stable@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, Jan Kara <jack@suse.cz>,
Derek Basehore <dbasehore@chromium.org>,
Jens Axboe <axboe@kernel.dk>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Jiri Slaby <jslaby@suse.cz>
Subject: [PATCH 3.12 18/50] bdi: avoid oops on device removal
Date: Mon, 5 May 2014 14:43:00 +0200 [thread overview]
Message-ID: <fa48decc1df0ec789d7bb2ea737f823f649a3cc3.1399292849.git.jslaby@suse.cz> (raw)
In-Reply-To: <7d4f4737432af6216e86975e587331b9d8b08063.1399292849.git.jslaby@suse.cz>
In-Reply-To: <cover.1399292849.git.jslaby@suse.cz>
From: Jan Kara <jack@suse.cz>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit 5acda9d12dcf1ad0d9a5a2a7c646de3472fa7555 upstream.
After commit 839a8e8660b6 ("writeback: replace custom worker pool
implementation with unbound workqueue") when device is removed while we
are writing to it we crash in bdi_writeback_workfn() ->
set_worker_desc() because bdi->dev is NULL.
This can happen because even though bdi_unregister() cancels all pending
flushing work, nothing really prevents new ones from being queued from
balance_dirty_pages() or other places.
Fix the problem by clearing BDI_registered bit in bdi_unregister() and
checking it before scheduling of any flushing work.
Fixes: 839a8e8660b6777e7fe4e80af1a048aebe2b5977
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Derek Basehore <dbasehore@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
fs/fs-writeback.c | 23 ++++++++++++++++++-----
include/linux/backing-dev.h | 2 +-
mm/backing-dev.c | 13 +++++++++----
3 files changed, 28 insertions(+), 10 deletions(-)
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 6abd284754e2..5bbec31440a4 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -88,16 +88,29 @@ static inline struct inode *wb_inode(struct list_head *head)
#define CREATE_TRACE_POINTS
#include <trace/events/writeback.h>
+static void bdi_wakeup_thread(struct backing_dev_info *bdi)
+{
+ spin_lock_bh(&bdi->wb_lock);
+ if (test_bit(BDI_registered, &bdi->state))
+ mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0);
+ spin_unlock_bh(&bdi->wb_lock);
+}
+
static void bdi_queue_work(struct backing_dev_info *bdi,
struct wb_writeback_work *work)
{
trace_writeback_queue(bdi, work);
spin_lock_bh(&bdi->wb_lock);
+ if (!test_bit(BDI_registered, &bdi->state)) {
+ if (work->done)
+ complete(work->done);
+ goto out_unlock;
+ }
list_add_tail(&work->list, &bdi->work_list);
- spin_unlock_bh(&bdi->wb_lock);
-
mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0);
+out_unlock:
+ spin_unlock_bh(&bdi->wb_lock);
}
static void
@@ -113,7 +126,7 @@ __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
work = kzalloc(sizeof(*work), GFP_ATOMIC);
if (!work) {
trace_writeback_nowork(bdi);
- mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0);
+ bdi_wakeup_thread(bdi);
return;
}
@@ -160,7 +173,7 @@ void bdi_start_background_writeback(struct backing_dev_info *bdi)
* writeback as soon as there is no other work to do.
*/
trace_writeback_wake_background(bdi);
- mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0);
+ bdi_wakeup_thread(bdi);
}
/*
@@ -1016,7 +1029,7 @@ void bdi_writeback_workfn(struct work_struct *work)
current->flags |= PF_SWAPWRITE;
if (likely(!current_is_workqueue_rescuer() ||
- list_empty(&bdi->bdi_list))) {
+ !test_bit(BDI_registered, &bdi->state))) {
/*
* The normal path. Keep writing back @bdi until its
* work_list is empty. Note that this path is also taken
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 5f66d519a726..a4cf599ecfc8 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -95,7 +95,7 @@ struct backing_dev_info {
unsigned int max_ratio, max_prop_frac;
struct bdi_writeback wb; /* default writeback info for this bdi */
- spinlock_t wb_lock; /* protects work_list */
+ spinlock_t wb_lock; /* protects work_list & wb.dwork scheduling */
struct list_head work_list;
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index fab8401fc54e..09d9591b7708 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -297,7 +297,10 @@ void bdi_wakeup_thread_delayed(struct backing_dev_info *bdi)
unsigned long timeout;
timeout = msecs_to_jiffies(dirty_writeback_interval * 10);
- queue_delayed_work(bdi_wq, &bdi->wb.dwork, timeout);
+ spin_lock_bh(&bdi->wb_lock);
+ if (test_bit(BDI_registered, &bdi->state))
+ queue_delayed_work(bdi_wq, &bdi->wb.dwork, timeout);
+ spin_unlock_bh(&bdi->wb_lock);
}
/*
@@ -310,9 +313,6 @@ static void bdi_remove_from_list(struct backing_dev_info *bdi)
spin_unlock_bh(&bdi_lock);
synchronize_rcu_expedited();
-
- /* bdi_list is now unused, clear it to mark @bdi dying */
- INIT_LIST_HEAD(&bdi->bdi_list);
}
int bdi_register(struct backing_dev_info *bdi, struct device *parent,
@@ -363,6 +363,11 @@ static void bdi_wb_shutdown(struct backing_dev_info *bdi)
*/
bdi_remove_from_list(bdi);
+ /* Make sure nobody queues further work */
+ spin_lock_bh(&bdi->wb_lock);
+ clear_bit(BDI_registered, &bdi->state);
+ spin_unlock_bh(&bdi->wb_lock);
+
/*
* Drain work list and shutdown the delayed_work. At this point,
* @bdi->bdi_list is empty telling bdi_Writeback_workfn() that @bdi
--
1.9.2
next prev parent reply other threads:[~2014-05-05 12:49 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-05 12:28 [PATCH 3.12 00/50] 3.12.19-stable review Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 01/50] openvswitch: fix vport-netdev unregister Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 02/50] brcmsmac: fix deadlock on missing firmware Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 03/50] /dev/mem: handle out-of-bounds read/write Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 04/50] drivers/net: tulip_remove_one needs to call pci_disable_device() Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 05/50] Bluetooth: Add support for Intel Bluetooth device [8087:0a2a] Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 06/50] iommu/amd: Fix PASID format in INVALIDATE_IOTLB_PAGES command Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 07/50] usbatm: Fix dynamic_debug / ratelimited atm_dbg and atm_rldbg macros Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 08/50] printk: pr_debug_ratelimited: check state first to reduce "callbacks suppressed" messages Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 09/50] dcache: restore error on restart in prepend_path Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 10/50] __dentry_path() fixes Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 11/50] i2c: i801: enable Intel BayTrail SMBUS Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 12/50] e1000e: Fix no connectivity when driver loaded with cable out Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 13/50] ACPI / EC: Process rather than discard events in acpi_ec_clear Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 14/50] ARM: 7840/1: LPAE: don't reject mapping /dev/mem above 4GB Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 15/50] x86/quirks: Add workaround for AMD F16h Erratum792 Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 16/50] amd64_edac: Fix logic to determine channel for F15 M30h processors Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 17/50] backing_dev: fix hung task on sync Jiri Slaby
2014-05-05 12:43 ` Jiri Slaby [this message]
2014-05-05 12:43 ` [PATCH 3.12 19/50] virtio_balloon: don't softlockup on huge balloon changes Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 20/50] ipmi: Fix a race restarting the timer Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 21/50] KVM: ioapic: fix assignment of ioapic->rtc_status.pending_eoi (CVE-2014-0155) Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 22/50] net: ipv4: current group_info should be put after using Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 24/50] powerpc/8xx: mfspr SPRN_TBRx in lieu of mftb/mftbu is not supported Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 25/50] ACPI / sleep: remove panic in case hardware has changed after S4 Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 26/50] user namespace: fix incorrect memory barriers Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 27/50] x86: Adjust irq remapping quirk for older revisions of 5500/5520 chipsets Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 28/50] PCI: designware: Fix RC BAR to be single 64-bit non-prefetchable memory BAR Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 29/50] PCI: designware: Fix iATU programming for cfg1, io and mem viewport Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 30/50] ACPI / button: Add ACPI Button event via netlink routine Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 31/50] staging: comedi: 8255_pci: initialize MITE data window Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 32/50] tty: Set correct tty name in 'active' sysfs attribute Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 33/50] tty: Fix low_latency BUG Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 35/50] Bluetooth: Fix removing Long Term Key Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 36/50] xfs: fix directory hash ordering bug Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 37/50] Btrfs: skip submitting barrier for missing device Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 38/50] Btrfs: fix deadlock with nested trans handles Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 39/50] ext4: fix error return from ext4_ext_handle_uninitialized_extents() Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 40/50] ext4: fix partial cluster handling for bigalloc file systems Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 41/50] ext4: fix premature freeing of partial clusters split across leaf blocks Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 42/50] jffs2: Fix segmentation fault found in stress test Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 43/50] jffs2: Fix crash due to truncation of csize Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 44/50] jffs2: avoid soft-lockup in jffs2_reserve_space_gc() Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 45/50] jffs2: remove from wait queue after schedule() Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 46/50] sparc32: fix build failure for arch_jump_label_transform Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 47/50] sparc64: don't treat 64-bit syscall return codes as 32-bit Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 48/50] sparc64: Make sure %pil interrupts are enabled during hypervisor yield Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 49/50] wait: fix reparent_leader() vs EXIT_DEAD->EXIT_ZOMBIE race Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 50/50] exit: call disassociate_ctty() before exit_task_namespaces() Jiri Slaby
2014-05-05 15:45 ` [PATCH 3.12 00/50] 3.12.19-stable review Guenter Roeck
2014-05-06 14:57 ` Shuah Khan
2014-05-09 8:32 ` Jiri Slaby
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