diff mbox series

[v5,2/2] fuse: add default_request_timeout and max_request_timeout sysctls

Message ID 20240826203234.4079338-3-joannelkoong@gmail.com (mailing list archive)
State New
Headers show
Series fuse: add timeout option for requests | expand

Commit Message

Joanne Koong Aug. 26, 2024, 8:32 p.m. UTC
Introduce two new sysctls, "default_request_timeout" and
"max_request_timeout". These control how long (in seconds) a server can
take to reply to a request. If the server does not reply by the timeout,
then the connection will be aborted.

"default_request_timeout" sets the default timeout if no timeout is
specified by the fuse server on mount. 0 (default) indicates no default
timeout should be enforced. If the server did set a timeout, then
default_request_timeout will be ignored.

"max_request_timeout" sets the upper bound on how long the server may
take to reply to a request. 0 (default) indicates no maximum timeout. If
the max_request_timeout is set and the fuse server attempts to set a
timeout greater than max_request_timeout, the system will default to
max_request_timeout. Similarly, if default_request_timeout is greater
than max_request_timeout, the system will default to
max_request_timeout. If the server does not request a timeout and
default_request_timeout is set to 0 but max_request_timeout is set, then
the timeout will be max_request_timeout.

$ sysctl -a | grep fuse
fs.fuse.default_request_timeout = 0
fs.fuse.max_request_timeout = 0

$ echo 0x100000000 | sudo tee /proc/sys/fs/fuse/default_request_timeout
tee: /proc/sys/fs/fuse/default_request_timeout: Invalid argument

$ echo 0xFFFFFFFF | sudo tee /proc/sys/fs/fuse/default_request_timeout
0xFFFFFFFF

$ sysctl -a | grep fuse
fs.fuse.default_request_timeout = 4294967295
fs.fuse.max_request_timeout = 0

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Bernd Schubert <bschubert@ddn.com>
---
 Documentation/admin-guide/sysctl/fs.rst | 31 ++++++++++++++++++
 fs/fuse/Makefile                        |  2 +-
 fs/fuse/fuse_i.h                        | 16 ++++++++++
 fs/fuse/inode.c                         | 19 ++++++++++-
 fs/fuse/sysctl.c                        | 42 +++++++++++++++++++++++++
 5 files changed, 108 insertions(+), 2 deletions(-)
 create mode 100644 fs/fuse/sysctl.c

Comments

kernel test robot Aug. 27, 2024, 9:51 p.m. UTC | #1
Hi Joanne,

kernel test robot noticed the following build errors:

[auto build test ERROR on mszeredi-fuse/for-next]
[also build test ERROR on linus/master v6.11-rc5 next-20240827]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Joanne-Koong/fuse-add-optional-kernel-enforced-timeout-for-requests/20240827-043354
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git for-next
patch link:    https://lore.kernel.org/r/20240826203234.4079338-3-joannelkoong%40gmail.com
patch subject: [PATCH v5 2/2] fuse: add default_request_timeout and max_request_timeout sysctls
config: arc-randconfig-002-20240827 (https://download.01.org/0day-ci/archive/20240828/202408280419.yuu33o7t-lkp@intel.com/config)
compiler: arceb-elf-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240828/202408280419.yuu33o7t-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202408280419.yuu33o7t-lkp@intel.com/

All errors (new ones prefixed by >>):

>> fs/fuse/sysctl.c:30:5: error: redefinition of 'fuse_sysctl_register'
      30 | int fuse_sysctl_register(void)
         |     ^~~~~~~~~~~~~~~~~~~~
   In file included from fs/fuse/sysctl.c:9:
   fs/fuse/fuse_i.h:1495:19: note: previous definition of 'fuse_sysctl_register' with type 'int(void)'
    1495 | static inline int fuse_sysctl_register(void) { return 0; }
         |                   ^~~~~~~~~~~~~~~~~~~~
>> fs/fuse/sysctl.c:38:6: error: redefinition of 'fuse_sysctl_unregister'
      38 | void fuse_sysctl_unregister(void)
         |      ^~~~~~~~~~~~~~~~~~~~~~
   fs/fuse/fuse_i.h:1496:20: note: previous definition of 'fuse_sysctl_unregister' with type 'void(void)'
    1496 | static inline void fuse_sysctl_unregister(void) { return; }
         |                    ^~~~~~~~~~~~~~~~~~~~~~


vim +/fuse_sysctl_register +30 fs/fuse/sysctl.c

    29	
  > 30	int fuse_sysctl_register(void)
    31	{
    32		fuse_table_header = register_sysctl("fs/fuse", fuse_sysctl_table);
    33		if (!fuse_table_header)
    34			return -ENOMEM;
    35		return 0;
    36	}
    37	
  > 38	void fuse_sysctl_unregister(void)
Joanne Koong Aug. 28, 2024, 3:51 p.m. UTC | #2
On Tue, Aug 27, 2024 at 2:52 PM kernel test robot <lkp@intel.com> wrote:
>
> Hi Joanne,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on mszeredi-fuse/for-next]
> [also build test ERROR on linus/master v6.11-rc5 next-20240827]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url:    https://github.com/intel-lab-lkp/linux/commits/Joanne-Koong/fuse-add-optional-kernel-enforced-timeout-for-requests/20240827-043354
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git for-next
> patch link:    https://lore.kernel.org/r/20240826203234.4079338-3-joannelkoong%40gmail.com
> patch subject: [PATCH v5 2/2] fuse: add default_request_timeout and max_request_timeout sysctls
> config: arc-randconfig-002-20240827 (https://download.01.org/0day-ci/archive/20240828/202408280419.yuu33o7t-lkp@intel.com/config)
> compiler: arceb-elf-gcc (GCC) 13.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240828/202408280419.yuu33o7t-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202408280419.yuu33o7t-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
> >> fs/fuse/sysctl.c:30:5: error: redefinition of 'fuse_sysctl_register'
>       30 | int fuse_sysctl_register(void)
>          |     ^~~~~~~~~~~~~~~~~~~~
>    In file included from fs/fuse/sysctl.c:9:
>    fs/fuse/fuse_i.h:1495:19: note: previous definition of 'fuse_sysctl_register' with type 'int(void)'
>     1495 | static inline int fuse_sysctl_register(void) { return 0; }
>          |                   ^~~~~~~~~~~~~~~~~~~~
> >> fs/fuse/sysctl.c:38:6: error: redefinition of 'fuse_sysctl_unregister'
>       38 | void fuse_sysctl_unregister(void)
>          |      ^~~~~~~~~~~~~~~~~~~~~~
>    fs/fuse/fuse_i.h:1496:20: note: previous definition of 'fuse_sysctl_unregister' with type 'void(void)'
>     1496 | static inline void fuse_sysctl_unregister(void) { return; }
>          |                    ^~~~~~~~~~~~~~~~~~~~~~
>

I see. In the Makefile, the sysctl.o needs to be gated by CONFIG_SYSCTL
eg
fuse-$(CONFIG_SYSCTL) += sysctl.o

I'll wait a bit to see if there are more comments on this patchset
before submitting v6.

>
> vim +/fuse_sysctl_register +30 fs/fuse/sysctl.c
>
>     29
>   > 30  int fuse_sysctl_register(void)
>     31  {
>     32          fuse_table_header = register_sysctl("fs/fuse", fuse_sysctl_table);
>     33          if (!fuse_table_header)
>     34                  return -ENOMEM;
>     35          return 0;
>     36  }
>     37
>   > 38  void fuse_sysctl_unregister(void)
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
Yafang Shao Aug. 29, 2024, 3:58 a.m. UTC | #3
On Wed, Aug 28, 2024 at 11:51 PM Joanne Koong <joannelkoong@gmail.com> wrote:
>
> On Tue, Aug 27, 2024 at 2:52 PM kernel test robot <lkp@intel.com> wrote:
> >
> > Hi Joanne,
> >
> > kernel test robot noticed the following build errors:
> >
> > [auto build test ERROR on mszeredi-fuse/for-next]
> > [also build test ERROR on linus/master v6.11-rc5 next-20240827]
> > [If your patch is applied to the wrong git tree, kindly drop us a note.
> > And when submitting patch, we suggest to use '--base' as documented in
> > https://git-scm.com/docs/git-format-patch#_base_tree_information]
> >
> > url:    https://github.com/intel-lab-lkp/linux/commits/Joanne-Koong/fuse-add-optional-kernel-enforced-timeout-for-requests/20240827-043354
> > base:   https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git for-next
> > patch link:    https://lore.kernel.org/r/20240826203234.4079338-3-joannelkoong%40gmail.com
> > patch subject: [PATCH v5 2/2] fuse: add default_request_timeout and max_request_timeout sysctls
> > config: arc-randconfig-002-20240827 (https://download.01.org/0day-ci/archive/20240828/202408280419.yuu33o7t-lkp@intel.com/config)
> > compiler: arceb-elf-gcc (GCC) 13.2.0
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240828/202408280419.yuu33o7t-lkp@intel.com/reproduce)
> >
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202408280419.yuu33o7t-lkp@intel.com/
> >
> > All errors (new ones prefixed by >>):
> >
> > >> fs/fuse/sysctl.c:30:5: error: redefinition of 'fuse_sysctl_register'
> >       30 | int fuse_sysctl_register(void)
> >          |     ^~~~~~~~~~~~~~~~~~~~
> >    In file included from fs/fuse/sysctl.c:9:
> >    fs/fuse/fuse_i.h:1495:19: note: previous definition of 'fuse_sysctl_register' with type 'int(void)'
> >     1495 | static inline int fuse_sysctl_register(void) { return 0; }
> >          |                   ^~~~~~~~~~~~~~~~~~~~
> > >> fs/fuse/sysctl.c:38:6: error: redefinition of 'fuse_sysctl_unregister'
> >       38 | void fuse_sysctl_unregister(void)
> >          |      ^~~~~~~~~~~~~~~~~~~~~~
> >    fs/fuse/fuse_i.h:1496:20: note: previous definition of 'fuse_sysctl_unregister' with type 'void(void)'
> >     1496 | static inline void fuse_sysctl_unregister(void) { return; }
> >          |                    ^~~~~~~~~~~~~~~~~~~~~~
> >
>
> I see. In the Makefile, the sysctl.o needs to be gated by CONFIG_SYSCTL
> eg
> fuse-$(CONFIG_SYSCTL) += sysctl.o
>
> I'll wait a bit to see if there are more comments on this patchset
> before submitting v6.

Hello Joanne,

I noticed a change in behavior between versions v5 and v4 during my
hellofuse test.

- Setup:
  1. Set fs.fuse.default_request_timeout to 10.
  2. Start the hellofuse daemon, with FUSE mounted on /tmp/fuse/.
  3. Run `cat /tmp/fuse/hello` and kill it within 10 seconds to
trigger a Timer expired event.
  4. Run `cat /tmp/fuse/hello` again.

- v4:
  After the Timer expired event occurs, running `cat /tmp/fuse/hello`
again is successful.

- v5:
  Running `cat /tmp/fuse/hello` fails with the error: "Transport
endpoint is not connected."

I believe this behavior in v5 is unintended, correct?

--
Regards



Yafang
Jingbo Xu Aug. 29, 2024, 6:38 a.m. UTC | #4
Hi, Yafang,

On 8/29/24 11:58 AM, Yafang Shao wrote:
> On Wed, Aug 28, 2024 at 11:51 PM Joanne Koong <joannelkoong@gmail.com> wrote:
>>
>> On Tue, Aug 27, 2024 at 2:52 PM kernel test robot <lkp@intel.com> wrote:
>>>
>>> Hi Joanne,
>>>
>>> kernel test robot noticed the following build errors:
>>>
>>> [auto build test ERROR on mszeredi-fuse/for-next]
>>> [also build test ERROR on linus/master v6.11-rc5 next-20240827]
>>> [If your patch is applied to the wrong git tree, kindly drop us a note.
>>> And when submitting patch, we suggest to use '--base' as documented in
>>> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>>>
>>> url:    https://github.com/intel-lab-lkp/linux/commits/Joanne-Koong/fuse-add-optional-kernel-enforced-timeout-for-requests/20240827-043354
>>> base:   https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git for-next
>>> patch link:    https://lore.kernel.org/r/20240826203234.4079338-3-joannelkoong%40gmail.com
>>> patch subject: [PATCH v5 2/2] fuse: add default_request_timeout and max_request_timeout sysctls
>>> config: arc-randconfig-002-20240827 (https://download.01.org/0day-ci/archive/20240828/202408280419.yuu33o7t-lkp@intel.com/config)
>>> compiler: arceb-elf-gcc (GCC) 13.2.0
>>> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240828/202408280419.yuu33o7t-lkp@intel.com/reproduce)
>>>
>>> If you fix the issue in a separate patch/commit (i.e. not just a new version of
>>> the same patch/commit), kindly add following tags
>>> | Reported-by: kernel test robot <lkp@intel.com>
>>> | Closes: https://lore.kernel.org/oe-kbuild-all/202408280419.yuu33o7t-lkp@intel.com/
>>>
>>> All errors (new ones prefixed by >>):
>>>
>>>>> fs/fuse/sysctl.c:30:5: error: redefinition of 'fuse_sysctl_register'
>>>       30 | int fuse_sysctl_register(void)
>>>          |     ^~~~~~~~~~~~~~~~~~~~
>>>    In file included from fs/fuse/sysctl.c:9:
>>>    fs/fuse/fuse_i.h:1495:19: note: previous definition of 'fuse_sysctl_register' with type 'int(void)'
>>>     1495 | static inline int fuse_sysctl_register(void) { return 0; }
>>>          |                   ^~~~~~~~~~~~~~~~~~~~
>>>>> fs/fuse/sysctl.c:38:6: error: redefinition of 'fuse_sysctl_unregister'
>>>       38 | void fuse_sysctl_unregister(void)
>>>          |      ^~~~~~~~~~~~~~~~~~~~~~
>>>    fs/fuse/fuse_i.h:1496:20: note: previous definition of 'fuse_sysctl_unregister' with type 'void(void)'
>>>     1496 | static inline void fuse_sysctl_unregister(void) { return; }
>>>          |                    ^~~~~~~~~~~~~~~~~~~~~~
>>>
>>
>> I see. In the Makefile, the sysctl.o needs to be gated by CONFIG_SYSCTL
>> eg
>> fuse-$(CONFIG_SYSCTL) += sysctl.o
>>
>> I'll wait a bit to see if there are more comments on this patchset
>> before submitting v6.
> 
> Hello Joanne,
> 
> I noticed a change in behavior between versions v5 and v4 during my
> hellofuse test.
> 
> - Setup:
>   1. Set fs.fuse.default_request_timeout to 10.
>   2. Start the hellofuse daemon, with FUSE mounted on /tmp/fuse/.
>   3. Run `cat /tmp/fuse/hello` and kill it within 10 seconds to
> trigger a Timer expired event.
>   4. Run `cat /tmp/fuse/hello` again.
> 
> - v4:
>   After the Timer expired event occurs, running `cat /tmp/fuse/hello`
> again is successful.
> 
> - v5:
>   Running `cat /tmp/fuse/hello` fails with the error: "Transport
> endpoint is not connected."
> 
> I believe this behavior in v5 is unintended, correct?
> 

I think v5 has changed the per-request timeout to per-connection timeout
according to Miklos's suggestion.  That is, once timedout, the whole
connection will be aborted.
Yafang Shao Aug. 29, 2024, 8:05 a.m. UTC | #5
On Thu, Aug 29, 2024 at 2:38 PM Jingbo Xu <jefflexu@linux.alibaba.com> wrote:
>
> Hi, Yafang,
>
> On 8/29/24 11:58 AM, Yafang Shao wrote:
> > On Wed, Aug 28, 2024 at 11:51 PM Joanne Koong <joannelkoong@gmail.com> wrote:
> >>
> >> On Tue, Aug 27, 2024 at 2:52 PM kernel test robot <lkp@intel.com> wrote:
> >>>
> >>> Hi Joanne,
> >>>
> >>> kernel test robot noticed the following build errors:
> >>>
> >>> [auto build test ERROR on mszeredi-fuse/for-next]
> >>> [also build test ERROR on linus/master v6.11-rc5 next-20240827]
> >>> [If your patch is applied to the wrong git tree, kindly drop us a note.
> >>> And when submitting patch, we suggest to use '--base' as documented in
> >>> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> >>>
> >>> url:    https://github.com/intel-lab-lkp/linux/commits/Joanne-Koong/fuse-add-optional-kernel-enforced-timeout-for-requests/20240827-043354
> >>> base:   https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git for-next
> >>> patch link:    https://lore.kernel.org/r/20240826203234.4079338-3-joannelkoong%40gmail.com
> >>> patch subject: [PATCH v5 2/2] fuse: add default_request_timeout and max_request_timeout sysctls
> >>> config: arc-randconfig-002-20240827 (https://download.01.org/0day-ci/archive/20240828/202408280419.yuu33o7t-lkp@intel.com/config)
> >>> compiler: arceb-elf-gcc (GCC) 13.2.0
> >>> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240828/202408280419.yuu33o7t-lkp@intel.com/reproduce)
> >>>
> >>> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> >>> the same patch/commit), kindly add following tags
> >>> | Reported-by: kernel test robot <lkp@intel.com>
> >>> | Closes: https://lore.kernel.org/oe-kbuild-all/202408280419.yuu33o7t-lkp@intel.com/
> >>>
> >>> All errors (new ones prefixed by >>):
> >>>
> >>>>> fs/fuse/sysctl.c:30:5: error: redefinition of 'fuse_sysctl_register'
> >>>       30 | int fuse_sysctl_register(void)
> >>>          |     ^~~~~~~~~~~~~~~~~~~~
> >>>    In file included from fs/fuse/sysctl.c:9:
> >>>    fs/fuse/fuse_i.h:1495:19: note: previous definition of 'fuse_sysctl_register' with type 'int(void)'
> >>>     1495 | static inline int fuse_sysctl_register(void) { return 0; }
> >>>          |                   ^~~~~~~~~~~~~~~~~~~~
> >>>>> fs/fuse/sysctl.c:38:6: error: redefinition of 'fuse_sysctl_unregister'
> >>>       38 | void fuse_sysctl_unregister(void)
> >>>          |      ^~~~~~~~~~~~~~~~~~~~~~
> >>>    fs/fuse/fuse_i.h:1496:20: note: previous definition of 'fuse_sysctl_unregister' with type 'void(void)'
> >>>     1496 | static inline void fuse_sysctl_unregister(void) { return; }
> >>>          |                    ^~~~~~~~~~~~~~~~~~~~~~
> >>>
> >>
> >> I see. In the Makefile, the sysctl.o needs to be gated by CONFIG_SYSCTL
> >> eg
> >> fuse-$(CONFIG_SYSCTL) += sysctl.o
> >>
> >> I'll wait a bit to see if there are more comments on this patchset
> >> before submitting v6.
> >
> > Hello Joanne,
> >
> > I noticed a change in behavior between versions v5 and v4 during my
> > hellofuse test.
> >
> > - Setup:
> >   1. Set fs.fuse.default_request_timeout to 10.
> >   2. Start the hellofuse daemon, with FUSE mounted on /tmp/fuse/.
> >   3. Run `cat /tmp/fuse/hello` and kill it within 10 seconds to
> > trigger a Timer expired event.
> >   4. Run `cat /tmp/fuse/hello` again.
> >
> > - v4:
> >   After the Timer expired event occurs, running `cat /tmp/fuse/hello`
> > again is successful.
> >
> > - v5:
> >   Running `cat /tmp/fuse/hello` fails with the error: "Transport
> > endpoint is not connected."
> >
> > I believe this behavior in v5 is unintended, correct?
> >
>
> I think v5 has changed the per-request timeout to per-connection timeout
> according to Miklos's suggestion.  That is, once timedout, the whole
> connection will be aborted.

Understood. Thanks for your explanation.
diff mbox series

Patch

diff --git a/Documentation/admin-guide/sysctl/fs.rst b/Documentation/admin-guide/sysctl/fs.rst
index 47499a1742bd..3d5a2b5cbba0 100644
--- a/Documentation/admin-guide/sysctl/fs.rst
+++ b/Documentation/admin-guide/sysctl/fs.rst
@@ -332,3 +332,34 @@  Each "watch" costs roughly 90 bytes on a 32-bit kernel, and roughly 160 bytes
 on a 64-bit one.
 The current default value for ``max_user_watches`` is 4% of the
 available low memory, divided by the "watch" cost in bytes.
+
+5. /proc/sys/fs/fuse - Configuration options for FUSE filesystems
+=====================================================================
+
+This directory contains the following configuration options for FUSE
+filesystems:
+
+``/proc/sys/fs/fuse/default_request_timeout`` is a read/write file for
+setting/getting the default timeout (in seconds) for a fuse server to
+reply to a kernel-issued request in the event where the server did not
+specify a timeout at mount. If the server set a timeout,
+then default_request_timeout will be ignored.  The default
+"default_request_timeout" is set to 0. 0 indicates a no-op (eg
+requests will not have a default request timeout set if no timeout was
+specified by the server).
+
+``/proc/sys/fs/fuse/max_request_timeout`` is a read/write file for
+setting/getting the maximum timeout (in seconds) for a fuse server to
+reply to a kernel-issued request. A value greater than 0 automatically opts
+the server into a timeout that will be at most "max_request_timeout", even if
+the server did not specify a timeout and default_request_timeout is set to 0.
+If max_request_timeout is greater than 0 and the server set a timeout greater
+than max_request_timeout or default_request_timeout is set to greater than
+max_request_timeout, the system will use max_request_timeout as the timeout.
+0 indicates a no-op (eg requests will not have an upper bound on the timeout
+and if the server did not request a timeout and default_request_timeout was not
+set, there will be no timeout).
+
+Please note that for the timeout options, if the server does not respond to
+the request by the time the timeout elapses, then the connection to the fuse
+server will be aborted.
diff --git a/fs/fuse/Makefile b/fs/fuse/Makefile
index 6e0228c6d0cb..cd4ef3e08ebf 100644
--- a/fs/fuse/Makefile
+++ b/fs/fuse/Makefile
@@ -7,7 +7,7 @@  obj-$(CONFIG_FUSE_FS) += fuse.o
 obj-$(CONFIG_CUSE) += cuse.o
 obj-$(CONFIG_VIRTIO_FS) += virtiofs.o
 
-fuse-y := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o ioctl.o
+fuse-y := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o ioctl.o sysctl.o
 fuse-y += iomode.o
 fuse-$(CONFIG_FUSE_DAX) += dax.o
 fuse-$(CONFIG_FUSE_PASSTHROUGH) += passthrough.o
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 97dacafa4289..04daf366735d 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -47,6 +47,14 @@ 
 /** Number of dentries for each connection in the control filesystem */
 #define FUSE_CTL_NUM_DENTRIES 5
 
+/*
+ * Default timeout (in seconds) for the server to reply to a request
+ * if no timeout was specified on mount
+ */
+extern u32 fuse_default_req_timeout;
+/** Max timeout (in seconds) for the server to reply to a request */
+extern u32 fuse_max_req_timeout;
+
 /** List of active connections */
 extern struct list_head fuse_conn_list;
 
@@ -1480,4 +1488,12 @@  ssize_t fuse_passthrough_splice_write(struct pipe_inode_info *pipe,
 				      size_t len, unsigned int flags);
 ssize_t fuse_passthrough_mmap(struct file *file, struct vm_area_struct *vma);
 
+#ifdef CONFIG_SYSCTL
+int fuse_sysctl_register(void);
+void fuse_sysctl_unregister(void);
+#else
+static inline int fuse_sysctl_register(void) { return 0; }
+static inline void fuse_sysctl_unregister(void) { return; }
+#endif /* CONFIG_SYSCTL */
+
 #endif /* _FS_FUSE_I_H */
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 9e69006fc026..cf333448f2d3 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -35,6 +35,10 @@  DEFINE_MUTEX(fuse_mutex);
 
 static int set_global_limit(const char *val, const struct kernel_param *kp);
 
+/* default is no timeout */
+u32 fuse_default_req_timeout = 0;
+u32 fuse_max_req_timeout = 0;
+
 unsigned max_user_bgreq;
 module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
 		  &max_user_bgreq, 0644);
@@ -1678,6 +1682,7 @@  int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx)
 	struct fuse_conn *fc = fm->fc;
 	struct inode *root;
 	struct dentry *root_dentry;
+	u32 req_timeout;
 	int err;
 
 	err = -EINVAL;
@@ -1730,10 +1735,16 @@  int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx)
 	fc->group_id = ctx->group_id;
 	fc->legacy_opts_show = ctx->legacy_opts_show;
 	fc->max_read = max_t(unsigned int, 4096, ctx->max_read);
-	fc->req_timeout = ctx->req_timeout * HZ;
 	fc->destroy = ctx->destroy;
 	fc->no_control = ctx->no_control;
 	fc->no_force_umount = ctx->no_force_umount;
+	req_timeout = ctx->req_timeout ?: fuse_default_req_timeout;
+	if (!fuse_max_req_timeout)
+		fc->req_timeout = req_timeout * HZ;
+	else if (!req_timeout)
+		fc->req_timeout = fuse_max_req_timeout * HZ;
+	else
+		fc->req_timeout = min(req_timeout, fuse_max_req_timeout) * HZ;
 
 	err = -ENOMEM;
 	root = fuse_get_root_inode(sb, ctx->rootmode);
@@ -2046,8 +2057,14 @@  static int __init fuse_fs_init(void)
 	if (err)
 		goto out3;
 
+	err = fuse_sysctl_register();
+	if (err)
+		goto out4;
+
 	return 0;
 
+ out4:
+	unregister_filesystem(&fuse_fs_type);
  out3:
 	unregister_fuseblk();
  out2:
diff --git a/fs/fuse/sysctl.c b/fs/fuse/sysctl.c
new file mode 100644
index 000000000000..c87bb0ecbfa9
--- /dev/null
+++ b/fs/fuse/sysctl.c
@@ -0,0 +1,42 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+* linux/fs/fuse/fuse_sysctl.c
+*
+* Sysctl interface to fuse parameters
+*/
+#include <linux/sysctl.h>
+
+#include "fuse_i.h"
+
+static struct ctl_table_header *fuse_table_header;
+
+static struct ctl_table fuse_sysctl_table[] = {
+	{
+		.procname	= "default_request_timeout",
+		.data		= &fuse_default_req_timeout,
+		.maxlen		= sizeof(fuse_default_req_timeout),
+		.mode		= 0644,
+		.proc_handler	= proc_douintvec,
+	},
+	{
+		.procname	= "max_request_timeout",
+		.data		= &fuse_max_req_timeout,
+		.maxlen		= sizeof(fuse_max_req_timeout),
+		.mode		= 0644,
+		.proc_handler	= proc_douintvec,
+	},
+};
+
+int fuse_sysctl_register(void)
+{
+	fuse_table_header = register_sysctl("fs/fuse", fuse_sysctl_table);
+	if (!fuse_table_header)
+		return -ENOMEM;
+	return 0;
+}
+
+void fuse_sysctl_unregister(void)
+{
+	unregister_sysctl_table(fuse_table_header);
+	fuse_table_header = NULL;
+}