* [PATCH] cifs: remove the retry in cifs_poxis_lock_set
@ 2020-06-24 7:10 yangerkun
2020-06-30 12:24 ` yangerkun
0 siblings, 1 reply; 4+ messages in thread
From: yangerkun @ 2020-06-24 7:10 UTC (permalink / raw)
To: sfrench, jlayton, neilb, neilb; +Cc: linux-cifs, samba-technical, linux-fsdevel
The caller of cifs_posix_lock_set will do retry(like
fcntl_setlk64->do_lock_file_wait) if we will wait for any file_lock.
So the retry in cifs_poxis_lock_set seems duplicated, remove it to
make a cleanup.
Signed-off-by: yangerkun <yangerkun@huawei.com>
---
fs/cifs/file.c | 8 --------
1 file changed, 8 deletions(-)
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 9b0f8f33f832..2c9c24b1805d 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1162,7 +1162,6 @@ cifs_posix_lock_set(struct file *file, struct file_lock *flock)
if ((flock->fl_flags & FL_POSIX) == 0)
return rc;
-try_again:
cifs_down_write(&cinode->lock_sem);
if (!cinode->can_cache_brlcks) {
up_write(&cinode->lock_sem);
@@ -1171,13 +1170,6 @@ cifs_posix_lock_set(struct file *file, struct file_lock *flock)
rc = posix_lock_file(file, flock, NULL);
up_write(&cinode->lock_sem);
- if (rc == FILE_LOCK_DEFERRED) {
- rc = wait_event_interruptible(flock->fl_wait,
- list_empty(&flock->fl_blocked_member));
- if (!rc)
- goto try_again;
- locks_delete_block(flock);
- }
return rc;
}
--
2.25.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] cifs: remove the retry in cifs_poxis_lock_set
2020-06-24 7:10 [PATCH] cifs: remove the retry in cifs_poxis_lock_set yangerkun
@ 2020-06-30 12:24 ` yangerkun
2020-06-30 22:34 ` NeilBrown
0 siblings, 1 reply; 4+ messages in thread
From: yangerkun @ 2020-06-30 12:24 UTC (permalink / raw)
To: sfrench, jlayton, neilb, neilb; +Cc: linux-cifs, samba-technical, linux-fsdevel
Ping...
在 2020/6/24 15:10, yangerkun 写道:
> The caller of cifs_posix_lock_set will do retry(like
> fcntl_setlk64->do_lock_file_wait) if we will wait for any file_lock.
> So the retry in cifs_poxis_lock_set seems duplicated, remove it to
> make a cleanup.
>
> Signed-off-by: yangerkun <yangerkun@huawei.com>
> ---
> fs/cifs/file.c | 8 --------
> 1 file changed, 8 deletions(-)
>
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index 9b0f8f33f832..2c9c24b1805d 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -1162,7 +1162,6 @@ cifs_posix_lock_set(struct file *file, struct file_lock *flock)
> if ((flock->fl_flags & FL_POSIX) == 0)
> return rc;
>
> -try_again:
> cifs_down_write(&cinode->lock_sem);
> if (!cinode->can_cache_brlcks) {
> up_write(&cinode->lock_sem);
> @@ -1171,13 +1170,6 @@ cifs_posix_lock_set(struct file *file, struct file_lock *flock)
>
> rc = posix_lock_file(file, flock, NULL);
> up_write(&cinode->lock_sem);
> - if (rc == FILE_LOCK_DEFERRED) {
> - rc = wait_event_interruptible(flock->fl_wait,
> - list_empty(&flock->fl_blocked_member));
> - if (!rc)
> - goto try_again;
> - locks_delete_block(flock);
> - }
> return rc;
> }
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] cifs: remove the retry in cifs_poxis_lock_set
2020-06-30 12:24 ` yangerkun
@ 2020-06-30 22:34 ` NeilBrown
2020-07-01 1:24 ` yangerkun
0 siblings, 1 reply; 4+ messages in thread
From: NeilBrown @ 2020-06-30 22:34 UTC (permalink / raw)
To: yangerkun, sfrench, jlayton, neilb
Cc: linux-cifs, samba-technical, linux-fsdevel
[-- Attachment #1: Type: text/plain, Size: 1860 bytes --]
On Tue, Jun 30 2020, yangerkun wrote:
> Ping...
>
> 在 2020/6/24 15:10, yangerkun 写道:
>> The caller of cifs_posix_lock_set will do retry(like
>> fcntl_setlk64->do_lock_file_wait) if we will wait for any file_lock.
>> So the retry in cifs_poxis_lock_set seems duplicated, remove it to
>> make a cleanup.
If cifs_posix_try_lock() returns FILE_LOCK_DEFERRED (which it might
after your patch), then cifs_setlk() will check the return value:
if (!rc || rc < 0)
return rc;
These tests will fail (as FILE_LOCK_DEFERRED is 1) and so it will
continue on as though the lock was granted.
So I think your patch is wrong.
However I think your goal is correct. cifs shouldn't be waiting.
No other filesystem waits when it gets FILE_LOCK_DEFERRED.
So maybe try to fix up your patch.
Thanks,
NeilBrown
>>
>> Signed-off-by: yangerkun <yangerkun@huawei.com>
>> ---
>> fs/cifs/file.c | 8 --------
>> 1 file changed, 8 deletions(-)
>>
>> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
>> index 9b0f8f33f832..2c9c24b1805d 100644
>> --- a/fs/cifs/file.c
>> +++ b/fs/cifs/file.c
>> @@ -1162,7 +1162,6 @@ cifs_posix_lock_set(struct file *file, struct file_lock *flock)
>> if ((flock->fl_flags & FL_POSIX) == 0)
>> return rc;
>>
>> -try_again:
>> cifs_down_write(&cinode->lock_sem);
>> if (!cinode->can_cache_brlcks) {
>> up_write(&cinode->lock_sem);
>> @@ -1171,13 +1170,6 @@ cifs_posix_lock_set(struct file *file, struct file_lock *flock)
>>
>> rc = posix_lock_file(file, flock, NULL);
>> up_write(&cinode->lock_sem);
>> - if (rc == FILE_LOCK_DEFERRED) {
>> - rc = wait_event_interruptible(flock->fl_wait,
>> - list_empty(&flock->fl_blocked_member));
>> - if (!rc)
>> - goto try_again;
>> - locks_delete_block(flock);
>> - }
>> return rc;
>> }
>>
>>
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] cifs: remove the retry in cifs_poxis_lock_set
2020-06-30 22:34 ` NeilBrown
@ 2020-07-01 1:24 ` yangerkun
0 siblings, 0 replies; 4+ messages in thread
From: yangerkun @ 2020-07-01 1:24 UTC (permalink / raw)
To: NeilBrown, sfrench, jlayton, neilb
Cc: linux-cifs, samba-technical, linux-fsdevel
在 2020/7/1 6:34, NeilBrown 写道:
> On Tue, Jun 30 2020, yangerkun wrote:
>
>> Ping...
>>
>> 在 2020/6/24 15:10, yangerkun 写道:
>>> The caller of cifs_posix_lock_set will do retry(like
>>> fcntl_setlk64->do_lock_file_wait) if we will wait for any file_lock.
>>> So the retry in cifs_poxis_lock_set seems duplicated, remove it to
>>> make a cleanup.
>
> If cifs_posix_try_lock() returns FILE_LOCK_DEFERRED (which it might
> after your patch), then cifs_setlk() will check the return value:
>
> if (!rc || rc < 0)
> return rc;
>
> These tests will fail (as FILE_LOCK_DEFERRED is 1) and so it will
> continue on as though the lock was granted.
>
> So I think your patch is wrong.
> However I think your goal is correct. cifs shouldn't be waiting.
> No other filesystem waits when it gets FILE_LOCK_DEFERRED.
>
> So maybe try to fix up your patch.
Yes, we should check FILE_LOCK_DEFERRED in cifs_setlk after this patch.
Also we may change 'int rc = 1;' exists in cifs_posix_lock_set since
FILE_LOCK_DEFERRED equals to 1.
I will send a v2 and thanks a lot for your review!
Thanks,
Kun.
> Thanks,
> NeilBrown
>
>
>>>
>>> Signed-off-by: yangerkun <yangerkun@huawei.com>
>>> ---
>>> fs/cifs/file.c | 8 --------
>>> 1 file changed, 8 deletions(-)
>>>
>>> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
>>> index 9b0f8f33f832..2c9c24b1805d 100644
>>> --- a/fs/cifs/file.c
>>> +++ b/fs/cifs/file.c
>>> @@ -1162,7 +1162,6 @@ cifs_posix_lock_set(struct file *file, struct file_lock *flock)
>>> if ((flock->fl_flags & FL_POSIX) == 0)
>>> return rc;
>>>
>>> -try_again:
>>> cifs_down_write(&cinode->lock_sem);
>>> if (!cinode->can_cache_brlcks) {
>>> up_write(&cinode->lock_sem);
>>> @@ -1171,13 +1170,6 @@ cifs_posix_lock_set(struct file *file, struct file_lock *flock)
>>>
>>> rc = posix_lock_file(file, flock, NULL);
>>> up_write(&cinode->lock_sem);
>>> - if (rc == FILE_LOCK_DEFERRED) {
>>> - rc = wait_event_interruptible(flock->fl_wait,
>>> - list_empty(&flock->fl_blocked_member));
>>> - if (!rc)
>>> - goto try_again;
>>> - locks_delete_block(flock);
>>> - }
>>> return rc;
>>> }
>>>
>>>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2020-06-24 7:10 [PATCH] cifs: remove the retry in cifs_poxis_lock_set yangerkun
2020-06-30 12:24 ` yangerkun
2020-06-30 22:34 ` NeilBrown
2020-07-01 1:24 ` yangerkun
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