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* fs: WARNING in locks_unlink_lock_ctx (not holding proper lock)
@ 2016-10-07 20:03 Dmitry Vyukov
  2016-10-07 23:26 ` Jeff Layton
  0 siblings, 1 reply; 7+ messages in thread
From: Dmitry Vyukov @ 2016-10-07 20:03 UTC (permalink / raw)
  To: Jeff Layton, Bruce Fields, Al Viro, linux-fsdevel, LKML; +Cc: syzkaller

Hello,

I am hitting lots of the following warnings while running syzkaller
fuzzer. Seems that path does not hold proper lock.

WARNING: CPU: 1 PID: 12090 at fs/locks.c:610 locks_unlink_lock_ctx+0x2c7/0x370
CPU: 1 PID: 12090 Comm: syz-executor Not tainted 4.8.0+ #28
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 ffff880038ba7728 ffffffff82d2b849 ffffffff00000016 fffffbfff10971e8
 ffffffff86e8c000 ffff880038ba7800 ffffffff86f42400 dffffc0000000000
 0000000000000009 ffff880038ba77f0 ffffffff816a229a 0000000041b58ab3
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff82d2b849>] dump_stack+0x12e/0x185 lib/dump_stack.c:51
 [<ffffffff816a229a>] panic+0x1e9/0x3f4 kernel/panic.c:153
 [<ffffffff81354fb9>] __warn+0x1c9/0x1e0 kernel/panic.c:509
 [<ffffffff813551a1>] warn_slowpath_null+0x31/0x40 kernel/panic.c:552
 [<     inline     >] locks_delete_global_locks fs/locks.c:610
 [<ffffffff8193b247>] locks_unlink_lock_ctx+0x2c7/0x370 fs/locks.c:739
 [<ffffffff8193b30f>] locks_delete_lock_ctx+0x1f/0x80 fs/locks.c:751
 [<ffffffff8193d329>] lease_modify+0x229/0x2e0 fs/locks.c:1370
 [<     inline     >] locks_remove_lease fs/locks.c:2528
 [<ffffffff81947408>] locks_remove_file+0x2d8/0x380 fs/locks.c:2551
 [<ffffffff8182eea6>] __fput+0x1a6/0x780 fs/file_table.c:200
 [<ffffffff8182f50a>] ____fput+0x1a/0x20 fs/file_table.c:244
 [<ffffffff813bae68>] task_work_run+0xf8/0x170 kernel/task_work.c:116
 [<     inline     >] exit_task_work include/linux/task_work.h:21
 [<ffffffff81364de4>] do_exit+0x864/0x2ad0 kernel/exit.c:828
 [<ffffffff813671cd>] do_group_exit+0x10d/0x330 kernel/exit.c:931
 [<ffffffff8138a57f>] get_signal+0x62f/0x15e0 kernel/signal.c:2307
 [<ffffffff811cf344>] do_signal+0x84/0x18f0 arch/x86/kernel/signal.c:807
 [<ffffffff8100629b>] exit_to_usermode_loop+0x13b/0x200
arch/x86/entry/common.c:156
 [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
 [<     inline     >] syscall_return_slowpath arch/x86/entry/common.c:259
 [<ffffffff81008a4f>] do_syscall_64+0x49f/0x620 arch/x86/entry/common.c:285

On commit a6930aaee06755d1bdcfd943fbf614e4d92bb0c7 (Oct 5).

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: fs: WARNING in locks_unlink_lock_ctx (not holding proper lock)
  2016-10-07 20:03 fs: WARNING in locks_unlink_lock_ctx (not holding proper lock) Dmitry Vyukov
@ 2016-10-07 23:26 ` Jeff Layton
  2016-10-08  8:12     ` Peter Zijlstra
  0 siblings, 1 reply; 7+ messages in thread
From: Jeff Layton @ 2016-10-07 23:26 UTC (permalink / raw)
  To: Dmitry Vyukov, Bruce Fields, Al Viro, linux-fsdevel, LKML
  Cc: syzkaller, Peter Zijlstra

On Fri, 2016-10-07 at 22:03 +0200, Dmitry Vyukov wrote:
> Hello,
> 
> I am hitting lots of the following warnings while running syzkaller
> fuzzer. Seems that path does not hold proper lock.
> 
> WARNING: CPU: 1 PID: 12090 at fs/locks.c:610 locks_unlink_lock_ctx+0x2c7/0x370
> CPU: 1 PID: 12090 Comm: syz-executor Not tainted 4.8.0+ #28
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>  ffff880038ba7728 ffffffff82d2b849 ffffffff00000016 fffffbfff10971e8
>  ffffffff86e8c000 ffff880038ba7800 ffffffff86f42400 dffffc0000000000
>  0000000000000009 ffff880038ba77f0 ffffffff816a229a 0000000041b58ab3
> Call Trace:
>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>  [<ffffffff82d2b849>] dump_stack+0x12e/0x185 lib/dump_stack.c:51
>  [<ffffffff816a229a>] panic+0x1e9/0x3f4 kernel/panic.c:153
>  [<ffffffff81354fb9>] __warn+0x1c9/0x1e0 kernel/panic.c:509
>  [<ffffffff813551a1>] warn_slowpath_null+0x31/0x40 kernel/panic.c:552
>  [<     inline     >] locks_delete_global_locks fs/locks.c:610
>  [<ffffffff8193b247>] locks_unlink_lock_ctx+0x2c7/0x370 fs/locks.c:739
>  [<ffffffff8193b30f>] locks_delete_lock_ctx+0x1f/0x80 fs/locks.c:751
>  [<ffffffff8193d329>] lease_modify+0x229/0x2e0 fs/locks.c:1370
>  [<     inline     >] locks_remove_lease fs/locks.c:2528
>  [<ffffffff81947408>] locks_remove_file+0x2d8/0x380 fs/locks.c:2551
>  [<ffffffff8182eea6>] __fput+0x1a6/0x780 fs/file_table.c:200
>  [<ffffffff8182f50a>] ____fput+0x1a/0x20 fs/file_table.c:244
>  [<ffffffff813bae68>] task_work_run+0xf8/0x170 kernel/task_work.c:116
>  [<     inline     >] exit_task_work include/linux/task_work.h:21
>  [<ffffffff81364de4>] do_exit+0x864/0x2ad0 kernel/exit.c:828
>  [<ffffffff813671cd>] do_group_exit+0x10d/0x330 kernel/exit.c:931
>  [<ffffffff8138a57f>] get_signal+0x62f/0x15e0 kernel/signal.c:2307
>  [<ffffffff811cf344>] do_signal+0x84/0x18f0 arch/x86/kernel/signal.c:807
>  [<ffffffff8100629b>] exit_to_usermode_loop+0x13b/0x200
> arch/x86/entry/common.c:156
>  [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
>  [<     inline     >] syscall_return_slowpath arch/x86/entry/common.c:259
>  [<ffffffff81008a4f>] do_syscall_64+0x49f/0x620 arch/x86/entry/common.c:285
> 
> On commit a6930aaee06755d1bdcfd943fbf614e4d92bb0c7 (Oct 5).

(cc'ing Peter...)

Well spotted. Yeah, I think you're right. The assertion is this:

    percpu_rwsem_assert_held(&file_rwsem);

I'm guessing this is probably fallout from the lglock to rwsem
conversion (commit aba376607383).

>From a quick glance, I think we probably just need to down_read the
file_rwsem in locks_remove_lease, prior to taking the flc_lock, and
release it just afterward. I do want to go over the code a little more
closely though to make sure other codepaths aren't missing that lock
though.

Thanks,
-- 
Jeff Layton <jlayton@poochiereds.net>

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: fs: WARNING in locks_unlink_lock_ctx (not holding proper lock)
  2016-10-07 23:26 ` Jeff Layton
@ 2016-10-08  8:12     ` Peter Zijlstra
  0 siblings, 0 replies; 7+ messages in thread
From: Peter Zijlstra @ 2016-10-08  8:12 UTC (permalink / raw)
  To: Jeff Layton
  Cc: Dmitry Vyukov, Bruce Fields, Al Viro, linux-fsdevel, LKML, syzkaller

On Fri, Oct 07, 2016 at 07:26:36PM -0400, Jeff Layton wrote:

> Well spotted. Yeah, I think you're right. The assertion is this:
> 
>     percpu_rwsem_assert_held(&file_rwsem);
> 
> I'm guessing this is probably fallout from the lglock to rwsem
> conversion (commit aba376607383).
> 
> From a quick glance, I think we probably just need to down_read the
> file_rwsem in locks_remove_lease, prior to taking the flc_lock, and
> release it just afterward.

Correct on all that.

> I do want to go over the code a little more
> closely though to make sure other codepaths aren't missing that lock
> though.

Urg, sorry for missing these, I went through it again and found the
below to be missing.

---
Subject: fs/locks: Add missing file_sem locks

I overlooked a few code-paths that can lead to
locks_delete_global_locks().

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---

diff --git a/fs/locks.c b/fs/locks.c
index 133fb2543d21..c623490863a9 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1604,6 +1604,7 @@ int fcntl_getlease(struct file *filp)
 
 	ctx = smp_load_acquire(&inode->i_flctx);
 	if (ctx && !list_empty_careful(&ctx->flc_lease)) {
+		percpu_down_read_preempt_disable(&file_rwsem);
 		spin_lock(&ctx->flc_lock);
 		time_out_leases(file_inode(filp), &dispose);
 		list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
@@ -1613,6 +1614,8 @@ int fcntl_getlease(struct file *filp)
 			break;
 		}
 		spin_unlock(&ctx->flc_lock);
+		percpu_up_read_preempt_enable(&file_rwsem);
+
 		locks_dispose_list(&dispose);
 	}
 	return type;
@@ -2522,11 +2525,14 @@ locks_remove_lease(struct file *filp, struct file_lock_context *ctx)
 	if (list_empty(&ctx->flc_lease))
 		return;
 
+	percpu_down_read_preempt_disable(&file_rwsem);
 	spin_lock(&ctx->flc_lock);
 	list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list)
 		if (filp == fl->fl_file)
 			lease_modify(fl, F_UNLCK, &dispose);
 	spin_unlock(&ctx->flc_lock);
+	percpu_up_read_preempt_enable(&file_rwsem);
+
 	locks_dispose_list(&dispose);
 }
 

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: fs: WARNING in locks_unlink_lock_ctx (not holding proper lock)
@ 2016-10-08  8:12     ` Peter Zijlstra
  0 siblings, 0 replies; 7+ messages in thread
From: Peter Zijlstra @ 2016-10-08  8:12 UTC (permalink / raw)
  To: Jeff Layton
  Cc: Dmitry Vyukov, Bruce Fields, Al Viro, linux-fsdevel, LKML, syzkaller

On Fri, Oct 07, 2016 at 07:26:36PM -0400, Jeff Layton wrote:

> Well spotted. Yeah, I think you're right. The assertion is this:
> 
> � � percpu_rwsem_assert_held(&file_rwsem);
> 
> I'm guessing this is probably fallout from the lglock to rwsem
> conversion (commit�aba376607383).
> 
> From a quick glance, I think we probably just need to down_read the
> file_rwsem in locks_remove_lease, prior to taking the flc_lock, and
> release it just afterward.

Correct on all that.

> I do want to go over the code a little more
> closely though to make sure other codepaths aren't missing that lock
> though.

Urg, sorry for missing these, I went through it again and found the
below to be missing.

---
Subject: fs/locks: Add missing file_sem locks

I overlooked a few code-paths that can lead to
locks_delete_global_locks().

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---

diff --git a/fs/locks.c b/fs/locks.c
index 133fb2543d21..c623490863a9 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1604,6 +1604,7 @@ int fcntl_getlease(struct file *filp)
 
 	ctx = smp_load_acquire(&inode->i_flctx);
 	if (ctx && !list_empty_careful(&ctx->flc_lease)) {
+		percpu_down_read_preempt_disable(&file_rwsem);
 		spin_lock(&ctx->flc_lock);
 		time_out_leases(file_inode(filp), &dispose);
 		list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
@@ -1613,6 +1614,8 @@ int fcntl_getlease(struct file *filp)
 			break;
 		}
 		spin_unlock(&ctx->flc_lock);
+		percpu_up_read_preempt_enable(&file_rwsem);
+
 		locks_dispose_list(&dispose);
 	}
 	return type;
@@ -2522,11 +2525,14 @@ locks_remove_lease(struct file *filp, struct file_lock_context *ctx)
 	if (list_empty(&ctx->flc_lease))
 		return;
 
+	percpu_down_read_preempt_disable(&file_rwsem);
 	spin_lock(&ctx->flc_lock);
 	list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list)
 		if (filp == fl->fl_file)
 			lease_modify(fl, F_UNLCK, &dispose);
 	spin_unlock(&ctx->flc_lock);
+	percpu_up_read_preempt_enable(&file_rwsem);
+
 	locks_dispose_list(&dispose);
 }
 

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: fs: WARNING in locks_unlink_lock_ctx (not holding proper lock)
  2016-10-08  8:12     ` Peter Zijlstra
  (?)
@ 2016-10-08 10:47     ` Jeff Layton
  -1 siblings, 0 replies; 7+ messages in thread
From: Jeff Layton @ 2016-10-08 10:47 UTC (permalink / raw)
  To: Peter Zijlstra
  Cc: Dmitry Vyukov, Bruce Fields, Al Viro, linux-fsdevel, LKML, syzkaller

On Sat, 2016-10-08 at 10:12 +0200, Peter Zijlstra wrote:
> On Fri, Oct 07, 2016 at 07:26:36PM -0400, Jeff Layton wrote:
> 
> > 
> > Well spotted. Yeah, I think you're right. The assertion is this:
> > 
> >     percpu_rwsem_assert_held(&file_rwsem);
> > 
> > I'm guessing this is probably fallout from the lglock to rwsem
> > conversion (commit aba376607383).
> > 
> > From a quick glance, I think we probably just need to down_read the
> > file_rwsem in locks_remove_lease, prior to taking the flc_lock, and
> > release it just afterward.
> 
> Correct on all that.
> 
> > 
> > I do want to go over the code a little more
> > closely though to make sure other codepaths aren't missing that lock
> > though.
> 
> Urg, sorry for missing these, I went through it again and found the
> below to be missing.
> 
> ---
> Subject: fs/locks: Add missing file_sem locks
> 
> I overlooked a few code-paths that can lead to
> locks_delete_global_locks().
> 
> Reported-by: Dmitry Vyukov <dvyukov@google.com>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> 
> diff --git a/fs/locks.c b/fs/locks.c
> index 133fb2543d21..c623490863a9 100644
> --- a/fs/locks.c
> +++ b/fs/locks.c
> @@ -1604,6 +1604,7 @@ int fcntl_getlease(struct file *filp)
>  
>  	ctx = smp_load_acquire(&inode->i_flctx);
>  	if (ctx && !list_empty_careful(&ctx->flc_lease)) {
> +		percpu_down_read_preempt_disable(&file_rwsem);
>  		spin_lock(&ctx->flc_lock);
>  		time_out_leases(file_inode(filp), &dispose);
>  		list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
> @@ -1613,6 +1614,8 @@ int fcntl_getlease(struct file *filp)
>  			break;
>  		}
>  		spin_unlock(&ctx->flc_lock);
> +		percpu_up_read_preempt_enable(&file_rwsem);
> +
>  		locks_dispose_list(&dispose);
>  	}
>  	return type;
> @@ -2522,11 +2525,14 @@ locks_remove_lease(struct file *filp, struct file_lock_context *ctx)
>  	if (list_empty(&ctx->flc_lease))
>  		return;
>  
> +	percpu_down_read_preempt_disable(&file_rwsem);
>  	spin_lock(&ctx->flc_lock);
>  	list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list)
>  		if (filp == fl->fl_file)
>  			lease_modify(fl, F_UNLCK, &dispose);
>  	spin_unlock(&ctx->flc_lock);
> +	percpu_up_read_preempt_enable(&file_rwsem);
> +
>  	locks_dispose_list(&dispose);
>  }
>  

Looks correct to me.

Peter, do you need me to pick this patch up or do you plan to get it to
Linus another way?

Thanks, and:

Reviewed-by: Jeff Layton <jlayton@poochiereds.net>

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [tip:locking/urgent] locking, fs/locks: Add missing file_sem locks
  2016-10-08  8:12     ` Peter Zijlstra
  (?)
  (?)
@ 2016-10-18  9:31     ` tip-bot for Peter Zijlstra
  -1 siblings, 0 replies; 7+ messages in thread
From: tip-bot for Peter Zijlstra @ 2016-10-18  9:31 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: tglx, dvyukov, peterz, torvalds, jlayton, bfields, linux-kernel,
	mingo, hpa, syzkaller, viro

Commit-ID:  1c7df9c183278052aedc3dcb9fecb8bf2b24a659
Gitweb:     http://git.kernel.org/tip/1c7df9c183278052aedc3dcb9fecb8bf2b24a659
Author:     Peter Zijlstra <peterz@infradead.org>
AuthorDate: Sat, 8 Oct 2016 10:12:28 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 18 Oct 2016 11:19:05 +0200

locking, fs/locks: Add missing file_sem locks

I overlooked a few code-paths that can lead to
locks_delete_global_locks().

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Jeff Layton <jlayton@poochiereds.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Bruce Fields <bfields@fieldses.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-fsdevel@vger.kernel.org
Cc: syzkaller <syzkaller@googlegroups.com>
Link: http://lkml.kernel.org/r/20161008081228.GF3142@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 fs/locks.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/locks.c b/fs/locks.c
index ce93b41..22c5b4a 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1609,6 +1609,7 @@ int fcntl_getlease(struct file *filp)
 
 	ctx = smp_load_acquire(&inode->i_flctx);
 	if (ctx && !list_empty_careful(&ctx->flc_lease)) {
+		percpu_down_read_preempt_disable(&file_rwsem);
 		spin_lock(&ctx->flc_lock);
 		time_out_leases(inode, &dispose);
 		list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
@@ -1618,6 +1619,8 @@ int fcntl_getlease(struct file *filp)
 			break;
 		}
 		spin_unlock(&ctx->flc_lock);
+		percpu_up_read_preempt_enable(&file_rwsem);
+
 		locks_dispose_list(&dispose);
 	}
 	return type;
@@ -2529,11 +2532,14 @@ locks_remove_lease(struct file *filp, struct file_lock_context *ctx)
 	if (list_empty(&ctx->flc_lease))
 		return;
 
+	percpu_down_read_preempt_disable(&file_rwsem);
 	spin_lock(&ctx->flc_lock);
 	list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list)
 		if (filp == fl->fl_file)
 			lease_modify(fl, F_UNLCK, &dispose);
 	spin_unlock(&ctx->flc_lock);
+	percpu_up_read_preempt_enable(&file_rwsem);
+
 	locks_dispose_list(&dispose);
 }
 

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [tip:locking/urgent] locking, fs/locks: Add missing file_sem locks
  2016-10-08  8:12     ` Peter Zijlstra
                       ` (2 preceding siblings ...)
  (?)
@ 2016-10-18 10:25     ` tip-bot for Peter Zijlstra
  -1 siblings, 0 replies; 7+ messages in thread
From: tip-bot for Peter Zijlstra @ 2016-10-18 10:25 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: torvalds, jlayton, bfields, dvyukov, tglx, viro, linux-kernel,
	peterz, hpa, mingo, syzkaller

Commit-ID:  5f43086bb9224987010460dcf3dee68fbd4f574d
Gitweb:     http://git.kernel.org/tip/5f43086bb9224987010460dcf3dee68fbd4f574d
Author:     Peter Zijlstra <peterz@infradead.org>
AuthorDate: Sat, 8 Oct 2016 10:12:28 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 18 Oct 2016 12:21:28 +0200

locking, fs/locks: Add missing file_sem locks

I overlooked a few code-paths that can lead to
locks_delete_global_locks().

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Jeff Layton <jlayton@poochiereds.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Bruce Fields <bfields@fieldses.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-fsdevel@vger.kernel.org
Cc: syzkaller <syzkaller@googlegroups.com>
Link: http://lkml.kernel.org/r/20161008081228.GF3142@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 fs/locks.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/locks.c b/fs/locks.c
index ce93b41..22c5b4a 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1609,6 +1609,7 @@ int fcntl_getlease(struct file *filp)
 
 	ctx = smp_load_acquire(&inode->i_flctx);
 	if (ctx && !list_empty_careful(&ctx->flc_lease)) {
+		percpu_down_read_preempt_disable(&file_rwsem);
 		spin_lock(&ctx->flc_lock);
 		time_out_leases(inode, &dispose);
 		list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
@@ -1618,6 +1619,8 @@ int fcntl_getlease(struct file *filp)
 			break;
 		}
 		spin_unlock(&ctx->flc_lock);
+		percpu_up_read_preempt_enable(&file_rwsem);
+
 		locks_dispose_list(&dispose);
 	}
 	return type;
@@ -2529,11 +2532,14 @@ locks_remove_lease(struct file *filp, struct file_lock_context *ctx)
 	if (list_empty(&ctx->flc_lease))
 		return;
 
+	percpu_down_read_preempt_disable(&file_rwsem);
 	spin_lock(&ctx->flc_lock);
 	list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, fl_list)
 		if (filp == fl->fl_file)
 			lease_modify(fl, F_UNLCK, &dispose);
 	spin_unlock(&ctx->flc_lock);
+	percpu_up_read_preempt_enable(&file_rwsem);
+
 	locks_dispose_list(&dispose);
 }
 

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2016-10-18 10:26 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-10-07 20:03 fs: WARNING in locks_unlink_lock_ctx (not holding proper lock) Dmitry Vyukov
2016-10-07 23:26 ` Jeff Layton
2016-10-08  8:12   ` Peter Zijlstra
2016-10-08  8:12     ` Peter Zijlstra
2016-10-08 10:47     ` Jeff Layton
2016-10-18  9:31     ` [tip:locking/urgent] locking, fs/locks: Add missing file_sem locks tip-bot for Peter Zijlstra
2016-10-18 10:25     ` tip-bot for Peter Zijlstra

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