The NULL return of 'd_splice_alias' dosen't mean error.
Signed-off-by: Wu Bo <[email protected]>
---
fs/f2fs/namei.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 77a71276ecb1..e5a3e39ce90c 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -577,7 +577,7 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
#endif
new = d_splice_alias(inode, dentry);
err = PTR_ERR_OR_ZERO(new);
- trace_f2fs_lookup_end(dir, dentry, ino, !new ? -ENOENT : err);
+ trace_f2fs_lookup_end(dir, new ? new : dentry, ino, err);
return new;
out_iput:
iput(inode);
--
2.35.3
On 05/24, Wu Bo wrote:
> The NULL return of 'd_splice_alias' dosen't mean error.
>
> Signed-off-by: Wu Bo <[email protected]>
> ---
> fs/f2fs/namei.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
> index 77a71276ecb1..e5a3e39ce90c 100644
> --- a/fs/f2fs/namei.c
> +++ b/fs/f2fs/namei.c
> @@ -577,7 +577,7 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
> #endif
> new = d_splice_alias(inode, dentry);
> err = PTR_ERR_OR_ZERO(new);
> - trace_f2fs_lookup_end(dir, dentry, ino, !new ? -ENOENT : err);
> + trace_f2fs_lookup_end(dir, new ? new : dentry, ino, err);
Shouldn't give an error pointer to the dentry field.
How about just giving the err?
- err = PTR_ERR_OR_ZERO(new);
- trace_f2fs_lookup_end(dir, dentry, ino, !new ? -ENOENT : err);
+ trace_f2fs_lookup_end(dir, dentry, ino, PTR_ERR_OR_ZERO(new));
> return new;
> out_iput:
> iput(inode);
> --
> 2.35.3
On 2023/5/27 1:21, Jaegeuk Kim wrote:
> On 05/24, Wu Bo wrote:
>> The NULL return of 'd_splice_alias' dosen't mean error.
>>
>> Signed-off-by: Wu Bo <[email protected]>
>> ---
>> fs/f2fs/namei.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
>> index 77a71276ecb1..e5a3e39ce90c 100644
>> --- a/fs/f2fs/namei.c
>> +++ b/fs/f2fs/namei.c
>> @@ -577,7 +577,7 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
>> #endif
>> new = c(inode, dentry);
>> err = PTR_ERR_OR_ZERO(new);
>> - trace_f2fs_lookup_end(dir, dentry, ino, !new ? -ENOENT : err);
>> + trace_f2fs_lookup_end(dir, new ? new : dentry, ino, err);
>
> Shouldn't give an error pointer to the dentry field.
>
> How about just giving the err?
>
> - err = PTR_ERR_OR_ZERO(new);
> - trace_f2fs_lookup_end(dir, dentry, ino, !new ? -ENOENT : err);
> + trace_f2fs_lookup_end(dir, dentry, ino, PTR_ERR_OR_ZERO(new));
static inline int __must_check PTR_ERR_OR_ZERO(__force const void *ptr)
{
if (IS_ERR(ptr))
return PTR_ERR(ptr);
else
return 0;
}
For below two cases, PTR_ERR_OR_ZERO(new) will return zero:
a) f2fs_lookup found existed dentry
b) f2fs_lookup didn't find existed dentry (-ENOENT case)
So in below commit, I passed -ENOENT to tracepoint for case b), so we can
distinguish result of f2fs_lookup in tracepoint, actually, -ENOENT is expected
value when we create a new file/directory.
Commit 84597b1f9b05 ("f2fs: fix wrong value of tracepoint parameter")
>
>
>> return new;
>> out_iput:
>> iput(inode);
>> --
>> 2.35.3
On Sat, May 27, 2023 at 09:01:41AM +0800, Chao Yu wrote:
> On 2023/5/27 1:21, Jaegeuk Kim wrote:
> > On 05/24, Wu Bo wrote:
> > > The NULL return of 'd_splice_alias' dosen't mean error.
> > >
> > > Signed-off-by: Wu Bo <[email protected]>
> > > ---
> > > fs/f2fs/namei.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
> > > index 77a71276ecb1..e5a3e39ce90c 100644
> > > --- a/fs/f2fs/namei.c
> > > +++ b/fs/f2fs/namei.c
> > > @@ -577,7 +577,7 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
> > > #endif
> > > new = c(inode, dentry);
> > > err = PTR_ERR_OR_ZERO(new);
> > > - trace_f2fs_lookup_end(dir, dentry, ino, !new ? -ENOENT : err);
> > > + trace_f2fs_lookup_end(dir, new ? new : dentry, ino, err);
> >
> > Shouldn't give an error pointer to the dentry field.
> >
> > How about just giving the err?
> >
> > - err = PTR_ERR_OR_ZERO(new);
> > - trace_f2fs_lookup_end(dir, dentry, ino, !new ? -ENOENT : err);
> > + trace_f2fs_lookup_end(dir, dentry, ino, PTR_ERR_OR_ZERO(new));
>
> static inline int __must_check PTR_ERR_OR_ZERO(__force const void *ptr)
> {
> if (IS_ERR(ptr))
> return PTR_ERR(ptr);
> else
> return 0;
> }
>
> For below two cases, PTR_ERR_OR_ZERO(new) will return zero:
> a) f2fs_lookup found existed dentry
> b) f2fs_lookup didn't find existed dentry (-ENOENT case)
>
> So in below commit, I passed -ENOENT to tracepoint for case b), so we can
> distinguish result of f2fs_lookup in tracepoint, actually, -ENOENT is expected
> value when we create a new file/directory.
>
> Commit 84597b1f9b05 ("f2fs: fix wrong value of tracepoint parameter")
I can see this commit is try to distinguish the dentry not existed case.
But a normal case which dentry is exactly found will also go through
'd_splice_alias', and its return is also NULL. This makes the tracepoint always
print 'err:-2' like the following:
ls-11676 [004] .... 329281.943118: f2fs_lookup_end: dev = (254,39), pino = 4451, name:Alarms, ino:7093, err:-2
ls-11676 [004] .... 329281.943145: f2fs_lookup_end: dev = (254,39), pino = 4451, name:Notifications, ino:7094, err:-2
ls-11676 [004] .... 329281.943172: f2fs_lookup_end: dev = (254,39), pino = 4451, name:Pictures, ino:7095, err:-2
Even these lookup are acctually successful, this is a bit strange.
>
> >
> >
> > > return new;
> > > out_iput:
> > > iput(inode);
> > > --
> > > 2.35.3
>
>
> _______________________________________________
> Linux-f2fs-devel mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
On 2023/5/29 12:13, Wu Bo wrote:
> On Sat, May 27, 2023 at 09:01:41AM +0800, Chao Yu wrote:
>> On 2023/5/27 1:21, Jaegeuk Kim wrote:
>>> On 05/24, Wu Bo wrote:
>>>> The NULL return of 'd_splice_alias' dosen't mean error.
>>>>
>>>> Signed-off-by: Wu Bo <[email protected]>
>>>> ---
>>>> fs/f2fs/namei.c | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
>>>> index 77a71276ecb1..e5a3e39ce90c 100644
>>>> --- a/fs/f2fs/namei.c
>>>> +++ b/fs/f2fs/namei.c
>>>> @@ -577,7 +577,7 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
>>>> #endif
>>>> new = c(inode, dentry);
>>>> err = PTR_ERR_OR_ZERO(new);
>>>> - trace_f2fs_lookup_end(dir, dentry, ino, !new ? -ENOENT : err);
>>>> + trace_f2fs_lookup_end(dir, new ? new : dentry, ino, err);
>>>
>>> Shouldn't give an error pointer to the dentry field.
>>>
>>> How about just giving the err?
>>>
>>> - err = PTR_ERR_OR_ZERO(new);
>>> - trace_f2fs_lookup_end(dir, dentry, ino, !new ? -ENOENT : err);
>>> + trace_f2fs_lookup_end(dir, dentry, ino, PTR_ERR_OR_ZERO(new));
>>
>> static inline int __must_check PTR_ERR_OR_ZERO(__force const void *ptr)
>> {
>> if (IS_ERR(ptr))
>> return PTR_ERR(ptr);
>> else
>> return 0;
>> }
>>
>> For below two cases, PTR_ERR_OR_ZERO(new) will return zero:
>> a) f2fs_lookup found existed dentry
>> b) f2fs_lookup didn't find existed dentry (-ENOENT case)
>>
>> So in below commit, I passed -ENOENT to tracepoint for case b), so we can
>> distinguish result of f2fs_lookup in tracepoint, actually, -ENOENT is expected
>> value when we create a new file/directory.
>>
>> Commit 84597b1f9b05 ("f2fs: fix wrong value of tracepoint parameter")
> I can see this commit is try to distinguish the dentry not existed case.
> But a normal case which dentry is exactly found will also go through
> 'd_splice_alias', and its return is also NULL. This makes the tracepoint always
> print 'err:-2' like the following:
> ls-11676 [004] .... 329281.943118: f2fs_lookup_end: dev = (254,39), pino = 4451, name:Alarms, ino:7093, err:-2
> ls-11676 [004] .... 329281.943145: f2fs_lookup_end: dev = (254,39), pino = 4451, name:Notifications, ino:7094, err:-2
> ls-11676 [004] .... 329281.943172: f2fs_lookup_end: dev = (254,39), pino = 4451, name:Pictures, ino:7095, err:-2
> Even these lookup are acctually successful, this is a bit strange.
Ah, I misunderstand return value's meaning of .lookup.
So, how about this? it only update err if d_splice_alias() returns a negative
value?
if (IS_ERR(new))
err = PTR_ERR(new);
trace_f2fs_lookup_end(dir, new ? new : dentry, ino, err);
Thanks,
>>
>>>
>>>
>>>> return new;
>>>> out_iput:
>>>> iput(inode);
>>>> --
>>>> 2.35.3
>>
>>
>> _______________________________________________
>> Linux-f2fs-devel mailing list
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
On 2023/5/29 18:18, Chao Yu wrote:
> On 2023/5/29 12:13, Wu Bo wrote:
>> On Sat, May 27, 2023 at 09:01:41AM +0800, Chao Yu wrote:
>>> On 2023/5/27 1:21, Jaegeuk Kim wrote:
>>>> On 05/24, Wu Bo wrote:
>>>>> The NULL return of 'd_splice_alias' dosen't mean error.
>>>>>
>>>>> Signed-off-by: Wu Bo <[email protected]>
>>>>> ---
>>>>> fs/f2fs/namei.c | 2 +-
>>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
>>>>> index 77a71276ecb1..e5a3e39ce90c 100644
>>>>> --- a/fs/f2fs/namei.c
>>>>> +++ b/fs/f2fs/namei.c
>>>>> @@ -577,7 +577,7 @@ static struct dentry *f2fs_lookup(struct inode
>>>>> *dir, struct dentry *dentry,
>>>>> #endif
>>>>> new = c(inode, dentry);
>>>>> err = PTR_ERR_OR_ZERO(new);
>>>>> - trace_f2fs_lookup_end(dir, dentry, ino, !new ? -ENOENT : err);
>>>>> + trace_f2fs_lookup_end(dir, new ? new : dentry, ino, err);
>>>>
>>>> Shouldn't give an error pointer to the dentry field.
>>>>
>>>> How about just giving the err?
>>>>
>>>> - err = PTR_ERR_OR_ZERO(new);
>>>> - trace_f2fs_lookup_end(dir, dentry, ino, !new ? -ENOENT : err);
>>>> + trace_f2fs_lookup_end(dir, dentry, ino, PTR_ERR_OR_ZERO(new));
>>>
>>> static inline int __must_check PTR_ERR_OR_ZERO(__force const void *ptr)
>>> {
>>> if (IS_ERR(ptr))
>>> return PTR_ERR(ptr);
>>> else
>>> return 0;
>>> }
>>>
>>> For below two cases, PTR_ERR_OR_ZERO(new) will return zero:
>>> a) f2fs_lookup found existed dentry
>>> b) f2fs_lookup didn't find existed dentry (-ENOENT case)
>>>
>>> So in below commit, I passed -ENOENT to tracepoint for case b), so
>>> we can
>>> distinguish result of f2fs_lookup in tracepoint, actually, -ENOENT
>>> is expected
>>> value when we create a new file/directory.
>>>
>>> Commit 84597b1f9b05 ("f2fs: fix wrong value of tracepoint parameter")
>> I can see this commit is try to distinguish the dentry not existed case.
>> But a normal case which dentry is exactly found will also go through
>> 'd_splice_alias', and its return is also NULL. This makes the
>> tracepoint always
>> print 'err:-2' like the following:
>> ls-11676 [004] .... 329281.943118: f2fs_lookup_end: dev =
>> (254,39), pino = 4451, name:Alarms, ino:7093, err:-2
>> ls-11676 [004] .... 329281.943145: f2fs_lookup_end: dev =
>> (254,39), pino = 4451, name:Notifications, ino:7094, err:-2
>> ls-11676 [004] .... 329281.943172: f2fs_lookup_end: dev =
>> (254,39), pino = 4451, name:Pictures, ino:7095, err:-2
>> Even these lookup are acctually successful, this is a bit strange.
>
> Ah, I misunderstand return value's meaning of .lookup.
>
> So, how about this? it only update err if d_splice_alias() returns a
> negative
> value?
>
> if (IS_ERR(new))
> err = PTR_ERR(new);
> trace_f2fs_lookup_end(dir, new ? new : dentry, ino, err);
>
> Thanks,
>
Yes, this will be better.
>>>
>>>>
>>>>
>>>>> return new;
>>>>> out_iput:
>>>>> iput(inode);
>>>>> --
>>>>> 2.35.3
>>>
>>>
>>> _______________________________________________
>>> Linux-f2fs-devel mailing list
>>> [email protected]
>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel