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Groups > linux.kernel > #1533822 > unrolled thread

[PATCH] fuse: freezing abort when use wait_event_killable{,_exclusive}().

Started bycuilifei <cuilifei@xiaomi.com>
First post2016-12-01 06:50 +0100
Last post2016-12-02 19:50 +0100
Articles 3 — 2 participants

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  [PATCH] fuse: freezing abort when use wait_event_killable{,_exclusive}(). cuilifei <cuilifei@xiaomi.com> - 2016-12-01 06:50 +0100
    Re: [PATCH] fuse: freezing abort when use  wait_event_killable{,_exclusive}(). kbuild test robot <lkp@intel.com> - 2016-12-02 17:20 +0100
    Re: [PATCH] fuse: freezing abort when use  wait_event_killable{,_exclusive}(). kbuild test robot <lkp@intel.com> - 2016-12-02 19:50 +0100

#1533822 — [PATCH] fuse: freezing abort when use wait_event_killable{,_exclusive}().

Fromcuilifei <cuilifei@xiaomi.com>
Date2016-12-01 06:50 +0100
Subject[PATCH] fuse: freezing abort when use wait_event_killable{,_exclusive}().
Message-ID<sJspQ-84b-7@gated-at.bofh.it>
Freezing process can abort when a client is waiting uninterruptibly
for a response. Add new macro wait_fatal_freezable to try to fix it.

Signed-off-by: cuilifei <cuilifei@xiaomi.com>
---
 fs/fuse/dev.c | 47 +++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 43 insertions(+), 4 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 70ea57c..40aea7d 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -23,6 +23,24 @@
 MODULE_ALIAS_MISCDEV(FUSE_MINOR);
 MODULE_ALIAS("devname:fuse");
 
+#define wait_fatal_freezable(wq, condition, exclusive)			\
+({									\
+	int __ret = 0;							\
+	do {								\
+		if (exclusive)						\
+			__ret = wait_event_interruptible_exclusive(wq,	\
+							condition);	\
+		else							\
+			__ret = wait_event_interruptible(wq,		\
+							condition);	\
+		if (!__ret || fatal_signal_pending(current))		\
+			break;						\
+		if (!freezing(current))					\
+			continue;					\
+	} while (try_to_freeze());					\
+	__ret;								\
+})
+
 static struct kmem_cache *fuse_req_cachep;
 
 static struct fuse_dev *fuse_get_dev(struct file *file)
@@ -99,6 +117,19 @@ void fuse_request_free(struct fuse_req *req)
 	kmem_cache_free(fuse_req_cachep, req);
 }
 
+static void block_sigs(sigset_t *oldset)
+{
+	sigset_t mask;
+
+	siginitsetinv(&mask, sigmask(SIGKILL));
+	sigprocmask(SIG_BLOCK, &mask, oldset);
+}
+
+static void restore_sigs(sigset_t *oldset)
+{
+	sigprocmask(SIG_SETMASK, oldset, NULL);
+}
+
 void __fuse_get_request(struct fuse_req *req)
 {
 	atomic_inc(&req->count);
@@ -134,13 +165,18 @@ static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
 				       bool for_background)
 {
 	struct fuse_req *req;
+	sigset_t oldset;
+	int intr;
 	int err;
 	atomic_inc(&fc->num_waiting);
 
 	if (fuse_block_alloc(fc, for_background)) {
 		err = -EINTR;
-		if (wait_event_killable_exclusive(fc->blocked_waitq,
-				!fuse_block_alloc(fc, for_background)))
+		block_sigs(&oldset);
+		intr = wait_fatal_freezable(fc->blocked_waitq,
+				!fuse_block_alloc(fc, for_background), true);
+		restore_sigs(&oldset);
+		if (intr)
 			goto out;
 	}
 	/* Matches smp_wmb() in fuse_set_initialized() */
@@ -427,9 +463,12 @@ static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
 	}
 
 	if (!test_bit(FR_FORCE, &req->flags)) {
+		sigset_t oldset;
 		/* Only fatal signals may interrupt this */
-		err = wait_event_killable(req->waitq,
-					test_bit(FR_FINISHED, &req->flags));
+		block_sigs(&oldset);
+		err = wait_fatal_freezable(req->waitq,
+				test_bit(FR_FINISHED, &req->flags), false);
+		restore_sigs(&oldset);
 		if (!err)
 			return;
 
-- 
1.9.1

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#1535055 — Re: [PATCH] fuse: freezing abort when use wait_event_killable{,_exclusive}().

Fromkbuild test robot <lkp@intel.com>
Date2016-12-02 17:20 +0100
SubjectRe: [PATCH] fuse: freezing abort when use wait_event_killable{,_exclusive}().
Message-ID<sJYJ3-69N-13@gated-at.bofh.it>
In reply to#1533822

[Multipart message — attachments visible in raw view] — view raw

Hi cuilifei,

[auto build test WARNING on fuse/for-next]
[also build test WARNING on v4.9-rc7 next-20161202]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/cuilifei/fuse-freezing-abort-when-use-wait_event_killable-_exclusive/20161202-234345
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git for-next
config: x86_64-randconfig-x013-201648 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All warnings (new ones prefixed by >>):

   In file included from include/uapi/linux/stddef.h:1:0,
                    from include/linux/stddef.h:4,
                    from include/uapi/linux/posix_types.h:4,
                    from include/uapi/linux/types.h:13,
                    from include/linux/types.h:5,
                    from include/uapi/linux/fuse.h:121,
                    from fs/fuse/fuse_i.h:12,
                    from fs/fuse/dev.c:9:
   fs/fuse/dev.c: In function '__fuse_get_req':
   fs/fuse/dev.c:38:8: error: implicit declaration of function 'freezing' [-Werror=implicit-function-declaration]
      if (!freezing(current))     \
           ^
   include/linux/compiler.h:149:30: note: in definition of macro '__trace_if'
     if (__builtin_constant_p(!!(cond)) ? !!(cond) :   \
                                 ^~~~
>> fs/fuse/dev.c:38:3: note: in expansion of macro 'if'
      if (!freezing(current))     \
      ^~
   fs/fuse/dev.c:176:10: note: in expansion of macro 'wait_fatal_freezable'
      intr = wait_fatal_freezable(fc->blocked_waitq,
             ^~~~~~~~~~~~~~~~~~~~
   fs/fuse/dev.c:40:11: error: implicit declaration of function 'try_to_freeze' [-Werror=implicit-function-declaration]
     } while (try_to_freeze());     \
              ^
   fs/fuse/dev.c:176:10: note: in expansion of macro 'wait_fatal_freezable'
      intr = wait_fatal_freezable(fc->blocked_waitq,
             ^~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors

vim +/if +38 fs/fuse/dev.c

     3	  Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
     4	
     5	  This program can be distributed under the terms of the GNU GPL.
     6	  See the file COPYING.
     7	*/
     8	
   > 9	#include "fuse_i.h"
    10	
    11	#include <linux/init.h>
    12	#include <linux/module.h>
    13	#include <linux/poll.h>
    14	#include <linux/uio.h>
    15	#include <linux/miscdevice.h>
    16	#include <linux/pagemap.h>
    17	#include <linux/file.h>
    18	#include <linux/slab.h>
    19	#include <linux/pipe_fs_i.h>
    20	#include <linux/swap.h>
    21	#include <linux/splice.h>
    22	
    23	MODULE_ALIAS_MISCDEV(FUSE_MINOR);
    24	MODULE_ALIAS("devname:fuse");
    25	
    26	#define wait_fatal_freezable(wq, condition, exclusive)			\
    27	({									\
    28		int __ret = 0;							\
    29		do {								\
    30			if (exclusive)						\
    31				__ret = wait_event_interruptible_exclusive(wq,	\
    32								condition);	\
    33			else							\
    34				__ret = wait_event_interruptible(wq,		\
    35								condition);	\
    36			if (!__ret || fatal_signal_pending(current))		\
    37				break;						\
  > 38			if (!freezing(current))					\
    39				continue;					\
    40		} while (try_to_freeze());					\
    41		__ret;								\

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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#1535123 — Re: [PATCH] fuse: freezing abort when use wait_event_killable{,_exclusive}().

Fromkbuild test robot <lkp@intel.com>
Date2016-12-02 19:50 +0100
SubjectRe: [PATCH] fuse: freezing abort when use wait_event_killable{,_exclusive}().
Message-ID<sK14d-7tU-11@gated-at.bofh.it>
In reply to#1533822

[Multipart message — attachments visible in raw view] — view raw

Hi cuilifei,

[auto build test ERROR on fuse/for-next]
[also build test ERROR on v4.9-rc7 next-20161202]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/cuilifei/fuse-freezing-abort-when-use-wait_event_killable-_exclusive/20161202-234345
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git for-next
config: x86_64-kexec (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

   fs/fuse/dev.c: In function '__fuse_get_req':
>> fs/fuse/dev.c:38:8: error: implicit declaration of function 'freezing' [-Werror=implicit-function-declaration]
      if (!freezing(current))     \
           ^
   fs/fuse/dev.c:176:10: note: in expansion of macro 'wait_fatal_freezable'
      intr = wait_fatal_freezable(fc->blocked_waitq,
             ^~~~~~~~~~~~~~~~~~~~
>> fs/fuse/dev.c:40:11: error: implicit declaration of function 'try_to_freeze' [-Werror=implicit-function-declaration]
     } while (try_to_freeze());     \
              ^
   fs/fuse/dev.c:176:10: note: in expansion of macro 'wait_fatal_freezable'
      intr = wait_fatal_freezable(fc->blocked_waitq,
             ^~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors

vim +/freezing +38 fs/fuse/dev.c

    32								condition);	\
    33			else							\
    34				__ret = wait_event_interruptible(wq,		\
    35								condition);	\
    36			if (!__ret || fatal_signal_pending(current))		\
    37				break;						\
  > 38			if (!freezing(current))					\
    39				continue;					\
  > 40		} while (try_to_freeze());					\
    41		__ret;								\
    42	})
    43	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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