[2/2] fs/fuse kio_pcs: check fuse_conn args

Submitted by Pavel Butsykin on May 17, 2018, 9:40 a.m.

Details

Message ID 20180517094009.32025-3-pbutsykin@virtuozzo.com
State New
Series "kpcs_probe: check fuse_conn args"
Headers show

Commit Message

Pavel Butsykin May 17, 2018, 9:40 a.m.
Allow initialization of kdirect only for vstorage/pstorage.

Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
---
 drivers/block/ploop/dev.c          |  4 ----
 fs/fuse/kio/pcs/pcs_fuse_kdirect.c | 23 +++++++++++++++++------
 include/linux/fs.h                 |  5 +++++
 3 files changed, 22 insertions(+), 10 deletions(-)

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diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
index 0e72656ec8f9..c6094144c7a5 100644
--- a/drivers/block/ploop/dev.c
+++ b/drivers/block/ploop/dev.c
@@ -3880,10 +3880,6 @@  static int ploop_truncate(struct ploop_device * plo, unsigned long arg)
 	return err;
 }
 
-#define IS_PSTORAGE(sb) (sb->s_magic == FUSE_SUPER_MAGIC && \
-			 (!strcmp(sb->s_subtype, "pstorage") || \
-			  !strcmp(sb->s_subtype, "vstorage")))
-
 static int ploop_bd_full(struct backing_dev_info *bdi, long long nr, int root)
 {
 	struct ploop_device *plo      = bdi->congested_data;
diff --git a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
index b8503d55e246..4b9c4a304571 100644
--- a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
+++ b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
@@ -144,13 +144,24 @@  void kpcs_conn_abort(struct fuse_conn *fc)
 }
 
 static int kpcs_probe(struct fuse_conn *fc, char *name)
-
 {
-	printk("%s TODO IMPLEMENT check fuse_conn args here!\n", __FUNCTION__);
-	if (!strncmp(name, kio_pcs_ops.name, FUSE_KIO_NAME))
-		return 1;
+	if (strncmp(name, kio_pcs_ops.name, FUSE_KIO_NAME)) {
+		printk(KERN_ERR "FUSE: kio_pcs: invalid kio_ops name: %s\n", name);
+		return 0;
+	}
 
-	return 0;
+	if (!(fc->flags & FUSE_KDIRECT_IO)) {
+		printk(KERN_ERR "FUSE: kio_pcs: kdirect is not enabled\n");
+		return 0;
+	}
+
+	if (!IS_PSTORAGE(fc->sb)) {
+		printk(KERN_ERR "FUSE: kio_pcs: kdirect is only available for"
+			            "pstorage/vstorage fuse mount\n");
+		return 0;
+	}
+
+	return 1;
 }
 
 
@@ -1202,7 +1213,7 @@  err:
 static struct fuse_kio_ops kio_pcs_ops = {
 	.name		= "pcs",
 	.owner		= THIS_MODULE,
-	.probe		= kpcs_probe, /*TODO: check sb->dev name */
+	.probe		= kpcs_probe,
 
 	.conn_init	= kpcs_conn_init,
 	.conn_fini	= kpcs_conn_fini,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a1dc3521f979..21770550b6c1 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1713,6 +1713,11 @@  struct super_block {
 	struct list_lru		s_inode_lru ____cacheline_aligned_in_smp;
 };
 
+#define IS_PSTORAGE(sb) ((sb)->s_magic == FUSE_SUPER_MAGIC && \
+			 (sb)->s_subtype && \
+			 (!strcmp((sb)->s_subtype, "pstorage") || \
+			  !strcmp((sb)->s_subtype, "vstorage")))
+
 extern const unsigned super_block_wrapper_version;
 struct super_block_wrapper {
 	struct super_block sb;

Comments

Kirill Tkhai May 17, 2018, 10:05 a.m.
Hi, Pasha,

On 17.05.2018 12:40, Pavel Butsykin wrote:
> Allow initialization of kdirect only for vstorage/pstorage.
> 
> Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
> ---
>  drivers/block/ploop/dev.c          |  4 ----
>  fs/fuse/kio/pcs/pcs_fuse_kdirect.c | 23 +++++++++++++++++------
>  include/linux/fs.h                 |  5 +++++
>  3 files changed, 22 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
> index 0e72656ec8f9..c6094144c7a5 100644
> --- a/drivers/block/ploop/dev.c
> +++ b/drivers/block/ploop/dev.c
> @@ -3880,10 +3880,6 @@ static int ploop_truncate(struct ploop_device * plo, unsigned long arg)
>  	return err;
>  }
>  
> -#define IS_PSTORAGE(sb) (sb->s_magic == FUSE_SUPER_MAGIC && \
> -			 (!strcmp(sb->s_subtype, "pstorage") || \
> -			  !strcmp(sb->s_subtype, "vstorage")))
> -
>  static int ploop_bd_full(struct backing_dev_info *bdi, long long nr, int root)
>  {
>  	struct ploop_device *plo      = bdi->congested_data;
> diff --git a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
> index b8503d55e246..4b9c4a304571 100644
> --- a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
> +++ b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
> @@ -144,13 +144,24 @@ void kpcs_conn_abort(struct fuse_conn *fc)
>  }
>  
>  static int kpcs_probe(struct fuse_conn *fc, char *name)
> -
>  {
> -	printk("%s TODO IMPLEMENT check fuse_conn args here!\n", __FUNCTION__);
> -	if (!strncmp(name, kio_pcs_ops.name, FUSE_KIO_NAME))
> -		return 1;
> +	if (strncmp(name, kio_pcs_ops.name, FUSE_KIO_NAME)) {
> +		printk(KERN_ERR "FUSE: kio_pcs: invalid kio_ops name: %s\n", name);

Despite there was printk() without error level modifier (which is not correct),
and printk(KERN_ERR) is better, let's follow the modern Linux kernel style,
which anyway will be requested in case of submitting patches to mainstream.
pr_err() is more likely to use for such the printing (see the rest of pr_* in printk.h).

> +		return 0;
> +	}
>  
> -	return 0;
> +	if (!(fc->flags & FUSE_KDIRECT_IO)) {
> +		printk(KERN_ERR "FUSE: kio_pcs: kdirect is not enabled\n");
> +		return 0;
> +	}

I don't think this is needed, since we already check for this bit in fuse_fill_super()
before call of fuse_kio_get(). But I'm not insist on this.

> +
> +	if (!IS_PSTORAGE(fc->sb)) {
> +		printk(KERN_ERR "FUSE: kio_pcs: kdirect is only available for"
> +			            "pstorage/vstorage fuse mount\n");
> +		return 0;
> +	}
> +
> +	return 1;
>  }
>  
>  
> @@ -1202,7 +1213,7 @@ err:
>  static struct fuse_kio_ops kio_pcs_ops = {
>  	.name		= "pcs",
>  	.owner		= THIS_MODULE,
> -	.probe		= kpcs_probe, /*TODO: check sb->dev name */
> +	.probe		= kpcs_probe,
>  
>  	.conn_init	= kpcs_conn_init,
>  	.conn_fini	= kpcs_conn_fini,
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index a1dc3521f979..21770550b6c1 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1713,6 +1713,11 @@ struct super_block {
>  	struct list_lru		s_inode_lru ____cacheline_aligned_in_smp;
>  };
>  
> +#define IS_PSTORAGE(sb) ((sb)->s_magic == FUSE_SUPER_MAGIC && \
> +			 (sb)->s_subtype && \
> +			 (!strcmp((sb)->s_subtype, "pstorage") || \
> +			  !strcmp((sb)->s_subtype, "vstorage")))
> +
>  extern const unsigned super_block_wrapper_version;
>  struct super_block_wrapper {
>  	struct super_block sb;
> 

Thanks,
Kirill
Pavel Butsykin May 17, 2018, 11:31 a.m.
On 17.05.2018 13:05, Kirill Tkhai wrote:
> Hi, Pasha,
> 
> On 17.05.2018 12:40, Pavel Butsykin wrote:
>> Allow initialization of kdirect only for vstorage/pstorage.
>>
>> Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
>> ---
>>   drivers/block/ploop/dev.c          |  4 ----
>>   fs/fuse/kio/pcs/pcs_fuse_kdirect.c | 23 +++++++++++++++++------
>>   include/linux/fs.h                 |  5 +++++
>>   3 files changed, 22 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
>> index 0e72656ec8f9..c6094144c7a5 100644
>> --- a/drivers/block/ploop/dev.c
>> +++ b/drivers/block/ploop/dev.c
>> @@ -3880,10 +3880,6 @@ static int ploop_truncate(struct ploop_device * plo, unsigned long arg)
>>   	return err;
>>   }
>>   
>> -#define IS_PSTORAGE(sb) (sb->s_magic == FUSE_SUPER_MAGIC && \
>> -			 (!strcmp(sb->s_subtype, "pstorage") || \
>> -			  !strcmp(sb->s_subtype, "vstorage")))
>> -
>>   static int ploop_bd_full(struct backing_dev_info *bdi, long long nr, int root)
>>   {
>>   	struct ploop_device *plo      = bdi->congested_data;
>> diff --git a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
>> index b8503d55e246..4b9c4a304571 100644
>> --- a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
>> +++ b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
>> @@ -144,13 +144,24 @@ void kpcs_conn_abort(struct fuse_conn *fc)
>>   }
>>   
>>   static int kpcs_probe(struct fuse_conn *fc, char *name)
>> -
>>   {
>> -	printk("%s TODO IMPLEMENT check fuse_conn args here!\n", __FUNCTION__);
>> -	if (!strncmp(name, kio_pcs_ops.name, FUSE_KIO_NAME))
>> -		return 1;
>> +	if (strncmp(name, kio_pcs_ops.name, FUSE_KIO_NAME)) {
>> +		printk(KERN_ERR "FUSE: kio_pcs: invalid kio_ops name: %s\n", name);
> 
> Despite there was printk() without error level modifier (which is not correct),
> and printk(KERN_ERR) is better, let's follow the modern Linux kernel style,
> which anyway will be requested in case of submitting patches to mainstream.
> pr_err() is more likely to use for such the printing (see the rest of pr_* in printk.h).
> 

ok, thanks.

>> +		return 0;
>> +	}
>>   
>> -	return 0;
>> +	if (!(fc->flags & FUSE_KDIRECT_IO)) {
>> +		printk(KERN_ERR "FUSE: kio_pcs: kdirect is not enabled\n");
>> +		return 0;
>> +	}
> 
> I don't think this is needed, since we already check for this bit in fuse_fill_super()
> before call of fuse_kio_get(). But I'm not insist on this.
>

And what is the meaning of this check:
"!strncmp(name, kio_pcs_ops.name, FUSE_KIO_NAME)" ?

We also already have this check. I assumed this can protect against
possible mistakes in the future.

>> +
>> +	if (!IS_PSTORAGE(fc->sb)) {
>> +		printk(KERN_ERR "FUSE: kio_pcs: kdirect is only available for"
>> +			            "pstorage/vstorage fuse mount\n");
>> +		return 0;
>> +	}
>> +
>> +	return 1;
>>   }
>>   
>>   
>> @@ -1202,7 +1213,7 @@ err:
>>   static struct fuse_kio_ops kio_pcs_ops = {
>>   	.name		= "pcs",
>>   	.owner		= THIS_MODULE,
>> -	.probe		= kpcs_probe, /*TODO: check sb->dev name */
>> +	.probe		= kpcs_probe,
>>   
>>   	.conn_init	= kpcs_conn_init,
>>   	.conn_fini	= kpcs_conn_fini,
>> diff --git a/include/linux/fs.h b/include/linux/fs.h
>> index a1dc3521f979..21770550b6c1 100644
>> --- a/include/linux/fs.h
>> +++ b/include/linux/fs.h
>> @@ -1713,6 +1713,11 @@ struct super_block {
>>   	struct list_lru		s_inode_lru ____cacheline_aligned_in_smp;
>>   };
>>   
>> +#define IS_PSTORAGE(sb) ((sb)->s_magic == FUSE_SUPER_MAGIC && \
>> +			 (sb)->s_subtype && \
>> +			 (!strcmp((sb)->s_subtype, "pstorage") || \
>> +			  !strcmp((sb)->s_subtype, "vstorage")))
>> +
>>   extern const unsigned super_block_wrapper_version;
>>   struct super_block_wrapper {
>>   	struct super_block sb;
>>
> 
> Thanks,
> Kirill
>
Kirill Tkhai May 17, 2018, 11:44 a.m.
On 17.05.2018 14:31, Pavel Butsykin wrote:
> On 17.05.2018 13:05, Kirill Tkhai wrote:
>> Hi, Pasha,
>>
>> On 17.05.2018 12:40, Pavel Butsykin wrote:
>>> Allow initialization of kdirect only for vstorage/pstorage.
>>>
>>> Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
>>> ---
>>>   drivers/block/ploop/dev.c          |  4 ----
>>>   fs/fuse/kio/pcs/pcs_fuse_kdirect.c | 23 +++++++++++++++++------
>>>   include/linux/fs.h                 |  5 +++++
>>>   3 files changed, 22 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
>>> index 0e72656ec8f9..c6094144c7a5 100644
>>> --- a/drivers/block/ploop/dev.c
>>> +++ b/drivers/block/ploop/dev.c
>>> @@ -3880,10 +3880,6 @@ static int ploop_truncate(struct ploop_device * plo, unsigned long arg)
>>>       return err;
>>>   }
>>>   -#define IS_PSTORAGE(sb) (sb->s_magic == FUSE_SUPER_MAGIC && \
>>> -             (!strcmp(sb->s_subtype, "pstorage") || \
>>> -              !strcmp(sb->s_subtype, "vstorage")))
>>> -
>>>   static int ploop_bd_full(struct backing_dev_info *bdi, long long nr, int root)
>>>   {
>>>       struct ploop_device *plo      = bdi->congested_data;
>>> diff --git a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
>>> index b8503d55e246..4b9c4a304571 100644
>>> --- a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
>>> +++ b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
>>> @@ -144,13 +144,24 @@ void kpcs_conn_abort(struct fuse_conn *fc)
>>>   }
>>>     static int kpcs_probe(struct fuse_conn *fc, char *name)
>>> -
>>>   {
>>> -    printk("%s TODO IMPLEMENT check fuse_conn args here!\n", __FUNCTION__);
>>> -    if (!strncmp(name, kio_pcs_ops.name, FUSE_KIO_NAME))
>>> -        return 1;
>>> +    if (strncmp(name, kio_pcs_ops.name, FUSE_KIO_NAME)) {
>>> +        printk(KERN_ERR "FUSE: kio_pcs: invalid kio_ops name: %s\n", name);
>>
>> Despite there was printk() without error level modifier (which is not correct),
>> and printk(KERN_ERR) is better, let's follow the modern Linux kernel style,
>> which anyway will be requested in case of submitting patches to mainstream.
>> pr_err() is more likely to use for such the printing (see the rest of pr_* in printk.h).
>>
> 
> ok, thanks.
> 
>>> +        return 0;
>>> +    }
>>>   -    return 0;
>>> +    if (!(fc->flags & FUSE_KDIRECT_IO)) {
>>> +        printk(KERN_ERR "FUSE: kio_pcs: kdirect is not enabled\n");
>>> +        return 0;
>>> +    }
>>
>> I don't think this is needed, since we already check for this bit in fuse_fill_super()
>> before call of fuse_kio_get(). But I'm not insist on this.
>>
> 
> And what is the meaning of this check:
> "!strncmp(name, kio_pcs_ops.name, FUSE_KIO_NAME)" ?

FUSE_KIO_NAME looks like a define of string, but it's a size,
and it was confusing for me.

Possible, we can drop this too. Less code is better for the attention.

> We also already have this check. I assumed this can protect against
> possible mistakes in the future.

I think, we fastly find the root cause in case of something is wrong
on mount. Duplications confuse... But I'm not insist on this.

>>> +
>>> +    if (!IS_PSTORAGE(fc->sb)) {
>>> +        printk(KERN_ERR "FUSE: kio_pcs: kdirect is only available for"
>>> +                        "pstorage/vstorage fuse mount\n");
>>> +        return 0;
>>> +    }
>>> +
>>> +    return 1;
>>>   }
>>>     @@ -1202,7 +1213,7 @@ err:
>>>   static struct fuse_kio_ops kio_pcs_ops = {
>>>       .name        = "pcs",
>>>       .owner        = THIS_MODULE,
>>> -    .probe        = kpcs_probe, /*TODO: check sb->dev name */
>>> +    .probe        = kpcs_probe,
>>>         .conn_init    = kpcs_conn_init,
>>>       .conn_fini    = kpcs_conn_fini,
>>> diff --git a/include/linux/fs.h b/include/linux/fs.h
>>> index a1dc3521f979..21770550b6c1 100644
>>> --- a/include/linux/fs.h
>>> +++ b/include/linux/fs.h
>>> @@ -1713,6 +1713,11 @@ struct super_block {
>>>       struct list_lru        s_inode_lru ____cacheline_aligned_in_smp;
>>>   };
>>>   +#define IS_PSTORAGE(sb) ((sb)->s_magic == FUSE_SUPER_MAGIC && \
>>> +             (sb)->s_subtype && \
>>> +             (!strcmp((sb)->s_subtype, "pstorage") || \
>>> +              !strcmp((sb)->s_subtype, "vstorage")))
>>> +
>>>   extern const unsigned super_block_wrapper_version;
>>>   struct super_block_wrapper {
>>>       struct super_block sb;
>>>
>>
>> Thanks,
>> Kirill
>>