[PATCH] nfs: local_lock: handle async processing of F_SETLK with FL_SLEEP

[PATCH] nfs: local_lock: handle async processing of F_SETLK with FL_SLEEP

[Vasily Averin]

nfsd and lockd use F_SETLK cmd with the FL_SLEEP flag set to request
asynchronous processing of blocking locks.

Currently nfs mounted with 'local_lock' option use locks_lock_file_wait()
function blocked on such requests.

To handle such requests properly, non-blocking posix_file_lock()
function should be used instead.

https://bugzilla.kernel.org/show_bug.cgi?id=215383
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
---
 fs/nfs/file.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 24e7dccce355..c9c974ee2f43 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -769,9 +769,11 @@ do_setlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
 	 */
 	if (!is_local)
 		status = NFS_PROTO(inode)->lock(filp, cmd, fl);
+	else if ((fl->fl_flags && FL_SLEEP) && IS_SETLK(cmd))
+		status = posix_lock_file(filp, fl, NULL);
 	else
 		status = locks_lock_file_wait(filp, fl);
-	if (status < 0)
+	if (status)
 		goto out;
 
 	/*
-- 
2.25.1

Re: [PATCH] nfs: local_lock: handle async processing of F_SETLK with FL_SLEEP

[kernel test robot]

Hi Vasily,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on trondmy-nfs/linux-next]
[also build test WARNING on v5.16-rc7 next-20211224]
[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]

url:    https://github.com/0day-ci/linux/commits/Vasily-Averin/nfs-local_lock-handle-async-processing-of-F_SETLK-with-FL_SLEEP/20211227-184705
base:   git://git.linux-nfs.org/projects/trondmy/linux-nfs.git linux-next
config: i386-randconfig-r034-20211227 (https://download.01.org/0day-ci/archive/20211227/202112272042.Xlz50x0x-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 511726c64d3b6cca66f7c54d457d586aa3129f67)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/00e7edbaaa914f1b049ab8a652c5a91483f4141d
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Vasily-Averin/nfs-local_lock-handle-async-processing-of-F_SETLK-with-FL_SLEEP/20211227-184705
        git checkout 00e7edbaaa914f1b049ab8a652c5a91483f4141d
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash fs/nfs/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> fs/nfs/file.c:772:25: warning: use of logical '&&' with constant operand [-Wconstant-logical-operand]
           else if ((fl->fl_flags && FL_SLEEP) && IS_SETLK(cmd))
                                  ^  ~~~~~~~~
   fs/nfs/file.c:772:25: note: use '&' for a bitwise operation
           else if ((fl->fl_flags && FL_SLEEP) && IS_SETLK(cmd))
                                  ^~
                                  &
   fs/nfs/file.c:772:25: note: remove constant to silence this warning
           else if ((fl->fl_flags && FL_SLEEP) && IS_SETLK(cmd))
                                 ~^~~~~~~~~~~
   1 warning generated.


vim +772 fs/nfs/file.c

   751	
   752	static int
   753	do_setlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
   754	{
   755		struct inode *inode = filp->f_mapping->host;
   756		int status;
   757	
   758		/*
   759		 * Flush all pending writes before doing anything
   760		 * with locks..
   761		 */
   762		status = nfs_sync_mapping(filp->f_mapping);
   763		if (status != 0)
   764			goto out;
   765	
   766		/*
   767		 * Use local locking if mounted with "-onolock" or with appropriate
   768		 * "-olocal_lock="
   769		 */
   770		if (!is_local)
   771			status = NFS_PROTO(inode)->lock(filp, cmd, fl);
 > 772		else if ((fl->fl_flags && FL_SLEEP) && IS_SETLK(cmd))
   773			status = posix_lock_file(filp, fl, NULL);
   774		else
   775			status = locks_lock_file_wait(filp, fl);
   776		if (status)
   777			goto out;
   778	
   779		/*
   780		 * Invalidate cache to prevent missing any changes.  If
   781		 * the file is mapped, clear the page cache as well so
   782		 * those mappings will be loaded.
   783		 *
   784		 * This makes locking act as a cache coherency point.
   785		 */
   786		nfs_sync_mapping(filp->f_mapping);
   787		if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ)) {
   788			nfs_zap_caches(inode);
   789			if (mapping_mapped(filp->f_mapping))
   790				nfs_revalidate_mapping(inode, filp->f_mapping);
   791		}
   792	out:
   793		return status;
   794	}
   795	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[PATCH v2] nfs: local_lock: handle async processing of F_SETLK with FL_SLEEP

[Vasily Averin]

nfsd and lockd use F_SETLK cmd with the FL_SLEEP flag set to request
asynchronous processing of blocking locks.

Currently nfs mounted with 'local_lock' option use locks_lock_file_wait()
function blocked on such requests.

To handle such requests properly, non-blocking posix_file_lock()
function should be used instead.

https://bugzilla.kernel.org/show_bug.cgi?id=215383
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
---
v2: fixed 'fl_flags && FL_SLEEP' => 'fl_flags & FL_SLEEP'
---
 fs/nfs/file.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 24e7dccce355..38e1821cff5d 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -769,9 +769,11 @@ do_setlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
 	 */
 	if (!is_local)
 		status = NFS_PROTO(inode)->lock(filp, cmd, fl);
+	else if ((fl->fl_flags & FL_SLEEP) && IS_SETLK(cmd))
+		status = posix_lock_file(filp, fl, NULL);
 	else
 		status = locks_lock_file_wait(filp, fl);
-	if (status < 0)
+	if (status)
 		goto out;
 
 	/*
-- 
2.25.1

Re: [PATCH v2] nfs: local_lock: handle async processing of F_SETLK with FL_SLEEP

[Vasily Averin]

Patch is wrong,
I missed that FL_FLOCK are handled here too.

On 27.12.2021 18:50, Vasily Averin wrote:
> nfsd and lockd use F_SETLK cmd with the FL_SLEEP flag set to request
> asynchronous processing of blocking locks.
> 
> Currently nfs mounted with 'local_lock' option use locks_lock_file_wait()
> function blocked on such requests.
> 
> To handle such requests properly, non-blocking posix_file_lock()
> function should be used instead.
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=215383
> Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
> ---
> v2: fixed 'fl_flags && FL_SLEEP' => 'fl_flags & FL_SLEEP'
> ---
>  fs/nfs/file.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/nfs/file.c b/fs/nfs/file.c
> index 24e7dccce355..38e1821cff5d 100644
> --- a/fs/nfs/file.c
> +++ b/fs/nfs/file.c
> @@ -769,9 +769,11 @@ do_setlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
>  	 */
>  	if (!is_local)
>  		status = NFS_PROTO(inode)->lock(filp, cmd, fl);
> +	else if ((fl->fl_flags & FL_SLEEP) && IS_SETLK(cmd))
> +		status = posix_lock_file(filp, fl, NULL);
>  	else
>  		status = locks_lock_file_wait(filp, fl);
> -	if (status < 0)
> +	if (status)
>  		goto out;
>  
>  	/*
> 

Re: [PATCH] nfs: local_lock: handle async processing of F_SETLK with FL_SLEEP

[Dan Carpenter]

Hi Vasily,

url:    https://github.com/0day-ci/linux/commits/Vasily-Averin/nfs-local_lock-handle-async-processing-of-F_SETLK-with-FL_SLEEP/20211227-184705
base:   git://git.linux-nfs.org/projects/trondmy/linux-nfs.git linux-next
config: i386-randconfig-m021-20211227 (https://download.01.org/0day-ci/archive/20211228/202112281211.SsWl4cfI-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

smatch warnings:
fs/nfs/file.c:772 do_setlk() warn: should this be a bitwise op?

vim +772 fs/nfs/file.c

5eebde23223aeb Suresh Jayaraman 2010-09-23  752  static int
5eebde23223aeb Suresh Jayaraman 2010-09-23  753  do_setlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
^1da177e4c3f41 Linus Torvalds   2005-04-16  754  {
^1da177e4c3f41 Linus Torvalds   2005-04-16  755  	struct inode *inode = filp->f_mapping->host;
^1da177e4c3f41 Linus Torvalds   2005-04-16  756  	int status;
^1da177e4c3f41 Linus Torvalds   2005-04-16  757  
^1da177e4c3f41 Linus Torvalds   2005-04-16  758  	/*
^1da177e4c3f41 Linus Torvalds   2005-04-16  759  	 * Flush all pending writes before doing anything
^1da177e4c3f41 Linus Torvalds   2005-04-16  760  	 * with locks..
^1da177e4c3f41 Linus Torvalds   2005-04-16  761  	 */
29884df0d89c1d Trond Myklebust  2005-12-13  762  	status = nfs_sync_mapping(filp->f_mapping);
29884df0d89c1d Trond Myklebust  2005-12-13  763  	if (status != 0)
^1da177e4c3f41 Linus Torvalds   2005-04-16  764  		goto out;
^1da177e4c3f41 Linus Torvalds   2005-04-16  765  
5eebde23223aeb Suresh Jayaraman 2010-09-23  766  	/*
5eebde23223aeb Suresh Jayaraman 2010-09-23  767  	 * Use local locking if mounted with "-onolock" or with appropriate
5eebde23223aeb Suresh Jayaraman 2010-09-23  768  	 * "-olocal_lock="
5eebde23223aeb Suresh Jayaraman 2010-09-23  769  	 */
5eebde23223aeb Suresh Jayaraman 2010-09-23  770  	if (!is_local)
^1da177e4c3f41 Linus Torvalds   2005-04-16  771  		status = NFS_PROTO(inode)->lock(filp, cmd, fl);
00e7edbaaa914f Vasily Averin    2021-12-27 @772  	else if ((fl->fl_flags && FL_SLEEP) && IS_SETLK(cmd))
                                                                               ^
&& vs &

00e7edbaaa914f Vasily Averin    2021-12-27  773  		status = posix_lock_file(filp, fl, NULL);
c4d7c402b788b7 Trond Myklebust  2008-04-01  774  	else
75575ddf29cbbf Jeff Layton      2016-09-17  775  		status = locks_lock_file_wait(filp, fl);
00e7edbaaa914f Vasily Averin    2021-12-27  776  	if (status)
^1da177e4c3f41 Linus Torvalds   2005-04-16  777  		goto out;
6b96724e507fec Ricardo Labiaga  2010-10-12  778  
^1da177e4c3f41 Linus Torvalds   2005-04-16  779  	/*
779eafab06036f NeilBrown        2017-08-18  780  	 * Invalidate cache to prevent missing any changes.  If
779eafab06036f NeilBrown        2017-08-18  781  	 * the file is mapped, clear the page cache as well so
779eafab06036f NeilBrown        2017-08-18  782  	 * those mappings will be loaded.
6b96724e507fec Ricardo Labiaga  2010-10-12  783  	 *
^1da177e4c3f41 Linus Torvalds   2005-04-16  784  	 * This makes locking act as a cache coherency point.
^1da177e4c3f41 Linus Torvalds   2005-04-16  785  	 */
29884df0d89c1d Trond Myklebust  2005-12-13  786  	nfs_sync_mapping(filp->f_mapping);
779eafab06036f NeilBrown        2017-08-18  787  	if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ)) {
442ce0499c0535 NeilBrown        2017-07-24  788  		nfs_zap_caches(inode);
779eafab06036f NeilBrown        2017-08-18  789  		if (mapping_mapped(filp->f_mapping))
779eafab06036f NeilBrown        2017-08-18  790  			nfs_revalidate_mapping(inode, filp->f_mapping);
779eafab06036f NeilBrown        2017-08-18  791  	}
^1da177e4c3f41 Linus Torvalds   2005-04-16  792  out:
^1da177e4c3f41 Linus Torvalds   2005-04-16  793  	return status;
^1da177e4c3f41 Linus Torvalds   2005-04-16  794  }

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org