From: NeilBrown <neilb@suse.de>
To: yangerkun <yangerkun@huawei.com>,
sfrench@samba.org, jlayton@kernel.org, neilb@suse.com
Cc: linux-cifs@vger.kernel.org, samba-technical@lists.samba.org,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH] cifs: remove the retry in cifs_poxis_lock_set
Date: Wed, 01 Jul 2020 08:34:26 +1000 [thread overview]
Message-ID: <878sg42nf1.fsf@notabene.neil.brown.name> (raw)
In-Reply-To: <62b291ab-291c-339f-e8e8-ba7b0c4f6670@huawei.com>
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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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next prev parent reply other threads:[~2020-06-30 22:34 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
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 [this message]
2020-07-01 1:24 ` yangerkun
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