diff mbox series

ceph: add 'noshare' mount option support

Message ID 20201013103112.12132-1-xiubli@redhat.com
State New
Headers show
Series ceph: add 'noshare' mount option support | expand

Commit Message

Xiubo Li Oct. 13, 2020, 10:31 a.m. UTC 
From: Xiubo Li <xiubli@redhat.com>

This will disable different mount points to share superblocks.

URL: https://tracker.ceph.com/issues/46883
Signed-off-by: Xiubo Li <xiubli@redhat.com>
---
 fs/ceph/super.c | 12 ++++++++++++
 fs/ceph/super.h |  1 +
 2 files changed, 13 insertions(+)

Comments

Jeff Layton Oct. 13, 2020, 12:31 p.m. UTC | #1 
On Tue, 2020-10-13 at 18:31 +0800, xiubli@redhat.com wrote:
> From: Xiubo Li <xiubli@redhat.com>

> 

> This will disable different mount points to share superblocks.

> 


Why? What problem does this solve? Don't make us dig through random
tracker bugs to determine this, please. :)

Also, the subject mentions a "noshare" mount option, but the code below
will be expecting sharesb/nosharesb.

> URL: https://tracker.ceph.com/issues/46883

> Signed-off-by: Xiubo Li <xiubli@redhat.com>

> ---

>  fs/ceph/super.c | 12 ++++++++++++

>  fs/ceph/super.h |  1 +

>  2 files changed, 13 insertions(+)

> 

> diff --git a/fs/ceph/super.c b/fs/ceph/super.c

> index 2f530a111b3a..6f283e4d62ee 100644

> --- a/fs/ceph/super.c

> +++ b/fs/ceph/super.c

> @@ -159,6 +159,7 @@ enum {

>  	Opt_quotadf,

>  	Opt_copyfrom,

>  	Opt_wsync,

> +	Opt_sharesb,

>  };

>  

>  enum ceph_recover_session_mode {

> @@ -199,6 +200,7 @@ static const struct fs_parameter_spec ceph_mount_parameters[] = {

>  	fsparam_string	("source",			Opt_source),

>  	fsparam_u32	("wsize",			Opt_wsize),

>  	fsparam_flag_no	("wsync",			Opt_wsync),

> +	fsparam_flag_no	("sharesb",			Opt_sharesb),

>  	{}

>  };

>  

> @@ -455,6 +457,12 @@ static int ceph_parse_mount_param(struct fs_context *fc,

>  		else

>  			fsopt->flags |= CEPH_MOUNT_OPT_ASYNC_DIROPS;

>  		break;

> +	case Opt_sharesb:

> +		if (!result.negated)

> +			fsopt->flags &= ~CEPH_MOUNT_OPT_NO_SHARE_SB;

> +		else

> +			fsopt->flags |= CEPH_MOUNT_OPT_NO_SHARE_SB;

> +		break;

>  	default:

>  		BUG();

>  	}

> @@ -1007,6 +1015,10 @@ static int ceph_compare_super(struct super_block *sb, struct fs_context *fc)

>  

>  	dout("ceph_compare_super %p\n", sb);

>  

> +	if (fsopt->flags & CEPH_MOUNT_OPT_NO_SHARE_SB ||

> +	    other->mount_options->flags & CEPH_MOUNT_OPT_NO_SHARE_SB)

> +		return 0;

> +

>  	if (compare_mount_options(fsopt, opt, other)) {

>  		dout("monitor(s)/mount options don't match\n");

>  		return 0;

> diff --git a/fs/ceph/super.h b/fs/ceph/super.h

> index f097237a5ad3..e877c21196e5 100644

> --- a/fs/ceph/super.h

> +++ b/fs/ceph/super.h

> @@ -44,6 +44,7 @@

>  #define CEPH_MOUNT_OPT_NOQUOTADF       (1<<13) /* no root dir quota in statfs */

>  #define CEPH_MOUNT_OPT_NOCOPYFROM      (1<<14) /* don't use RADOS 'copy-from' op */

>  #define CEPH_MOUNT_OPT_ASYNC_DIROPS    (1<<15) /* allow async directory ops */

> +#define CEPH_MOUNT_OPT_NO_SHARE_SB     (1<<16) /* disable sharing the same superblock */

>  

>  #define CEPH_MOUNT_OPT_DEFAULT			\

>  	(CEPH_MOUNT_OPT_DCACHE |		\


-- 
Jeff Layton <jlayton@kernel.org>
Xiubo Li Oct. 13, 2020, 12:44 p.m. UTC | #2 
On 2020/10/13 20:31, Jeff Layton wrote:
> On Tue, 2020-10-13 at 18:31 +0800, xiubli@redhat.com wrote:
>> From: Xiubo Li <xiubli@redhat.com>
>>
>> This will disable different mount points to share superblocks.
>>
> Why? What problem does this solve? Don't make us dig through random
> tracker bugs to determine this, please. :)

So, should we just mannully trigger to crash the kernel to get the 
coredump ?


> Also, the subject mentions a "noshare" mount option, but the code below
> will be expecting sharesb/nosharesb.
>
>> URL: https://tracker.ceph.com/issues/46883
>> Signed-off-by: Xiubo Li <xiubli@redhat.com>
>> ---
>>   fs/ceph/super.c | 12 ++++++++++++
>>   fs/ceph/super.h |  1 +
>>   2 files changed, 13 insertions(+)
>>
>> diff --git a/fs/ceph/super.c b/fs/ceph/super.c
>> index 2f530a111b3a..6f283e4d62ee 100644
>> --- a/fs/ceph/super.c
>> +++ b/fs/ceph/super.c
>> @@ -159,6 +159,7 @@ enum {
>>   	Opt_quotadf,
>>   	Opt_copyfrom,
>>   	Opt_wsync,
>> +	Opt_sharesb,
>>   };
>>   
>>   enum ceph_recover_session_mode {
>> @@ -199,6 +200,7 @@ static const struct fs_parameter_spec ceph_mount_parameters[] = {
>>   	fsparam_string	("source",			Opt_source),
>>   	fsparam_u32	("wsize",			Opt_wsize),
>>   	fsparam_flag_no	("wsync",			Opt_wsync),
>> +	fsparam_flag_no	("sharesb",			Opt_sharesb),
>>   	{}
>>   };
>>   
>> @@ -455,6 +457,12 @@ static int ceph_parse_mount_param(struct fs_context *fc,
>>   		else
>>   			fsopt->flags |= CEPH_MOUNT_OPT_ASYNC_DIROPS;
>>   		break;
>> +	case Opt_sharesb:
>> +		if (!result.negated)
>> +			fsopt->flags &= ~CEPH_MOUNT_OPT_NO_SHARE_SB;
>> +		else
>> +			fsopt->flags |= CEPH_MOUNT_OPT_NO_SHARE_SB;
>> +		break;
>>   	default:
>>   		BUG();
>>   	}
>> @@ -1007,6 +1015,10 @@ static int ceph_compare_super(struct super_block *sb, struct fs_context *fc)
>>   
>>   	dout("ceph_compare_super %p\n", sb);
>>   
>> +	if (fsopt->flags & CEPH_MOUNT_OPT_NO_SHARE_SB ||
>> +	    other->mount_options->flags & CEPH_MOUNT_OPT_NO_SHARE_SB)
>> +		return 0;
>> +
>>   	if (compare_mount_options(fsopt, opt, other)) {
>>   		dout("monitor(s)/mount options don't match\n");
>>   		return 0;
>> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
>> index f097237a5ad3..e877c21196e5 100644
>> --- a/fs/ceph/super.h
>> +++ b/fs/ceph/super.h
>> @@ -44,6 +44,7 @@
>>   #define CEPH_MOUNT_OPT_NOQUOTADF       (1<<13) /* no root dir quota in statfs */
>>   #define CEPH_MOUNT_OPT_NOCOPYFROM      (1<<14) /* don't use RADOS 'copy-from' op */
>>   #define CEPH_MOUNT_OPT_ASYNC_DIROPS    (1<<15) /* allow async directory ops */
>> +#define CEPH_MOUNT_OPT_NO_SHARE_SB     (1<<16) /* disable sharing the same superblock */
>>   
>>   #define CEPH_MOUNT_OPT_DEFAULT			\
>>   	(CEPH_MOUNT_OPT_DCACHE |		\
Jeff Layton Oct. 13, 2020, 1:41 p.m. UTC | #3 
On Tue, 2020-10-13 at 20:44 +0800, Xiubo Li wrote:
> On 2020/10/13 20:31, Jeff Layton wrote:
> > On Tue, 2020-10-13 at 18:31 +0800, xiubli@redhat.com wrote:
> > > From: Xiubo Li <xiubli@redhat.com>
> > > 
> > > This will disable different mount points to share superblocks.
> > > 
> > Why? What problem does this solve? Don't make us dig through random
> > tracker bugs to determine this, please. :)
> 
> So, should we just mannully trigger to crash the kernel to get the 
> coredump ?
> 

Looking at the tracker ticket, it looks like you want this to work
around some issues with lazy unmounts in tests.  If so, then sure,
forcing a coredump might give you an indication of what happened.

In general though, this sounds like a hacky workaround for the problem
in that tracker. I suggest we don't do this and work toward solving the
real problems that caused the test writers to use lazy umounts in the
first place...

> 
> > Also, the subject mentions a "noshare" mount option, but the code below
> > will be expecting sharesb/nosharesb.
> > 
> > > URL: https://tracker.ceph.com/issues/46883
> > > Signed-off-by: Xiubo Li <xiubli@redhat.com>
> > > ---
> > >   fs/ceph/super.c | 12 ++++++++++++
> > >   fs/ceph/super.h |  1 +
> > >   2 files changed, 13 insertions(+)
> > > 
> > > diff --git a/fs/ceph/super.c b/fs/ceph/super.c
> > > index 2f530a111b3a..6f283e4d62ee 100644
> > > --- a/fs/ceph/super.c
> > > +++ b/fs/ceph/super.c
> > > @@ -159,6 +159,7 @@ enum {
> > >   	Opt_quotadf,
> > >   	Opt_copyfrom,
> > >   	Opt_wsync,
> > > +	Opt_sharesb,
> > >   };
> > >   
> > >   enum ceph_recover_session_mode {
> > > @@ -199,6 +200,7 @@ static const struct fs_parameter_spec ceph_mount_parameters[] = {
> > >   	fsparam_string	("source",			Opt_source),
> > >   	fsparam_u32	("wsize",			Opt_wsize),
> > >   	fsparam_flag_no	("wsync",			Opt_wsync),
> > > +	fsparam_flag_no	("sharesb",			Opt_sharesb),
> > >   	{}
> > >   };
> > >   
> > > @@ -455,6 +457,12 @@ static int ceph_parse_mount_param(struct fs_context *fc,
> > >   		else
> > >   			fsopt->flags |= CEPH_MOUNT_OPT_ASYNC_DIROPS;
> > >   		break;
> > > +	case Opt_sharesb:
> > > +		if (!result.negated)
> > > +			fsopt->flags &= ~CEPH_MOUNT_OPT_NO_SHARE_SB;
> > > +		else
> > > +			fsopt->flags |= CEPH_MOUNT_OPT_NO_SHARE_SB;
> > > +		break;
> > >   	default:
> > >   		BUG();
> > >   	}
> > > @@ -1007,6 +1015,10 @@ static int ceph_compare_super(struct super_block *sb, struct fs_context *fc)
> > >   
> > >   	dout("ceph_compare_super %p\n", sb);
> > >   
> > > +	if (fsopt->flags & CEPH_MOUNT_OPT_NO_SHARE_SB ||
> > > +	    other->mount_options->flags & CEPH_MOUNT_OPT_NO_SHARE_SB)
> > > +		return 0;
> > > +
> > >   	if (compare_mount_options(fsopt, opt, other)) {
> > >   		dout("monitor(s)/mount options don't match\n");
> > >   		return 0;
> > > diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> > > index f097237a5ad3..e877c21196e5 100644
> > > --- a/fs/ceph/super.h
> > > +++ b/fs/ceph/super.h
> > > @@ -44,6 +44,7 @@
> > >   #define CEPH_MOUNT_OPT_NOQUOTADF       (1<<13) /* no root dir quota in statfs */
> > >   #define CEPH_MOUNT_OPT_NOCOPYFROM      (1<<14) /* don't use RADOS 'copy-from' op */
> > >   #define CEPH_MOUNT_OPT_ASYNC_DIROPS    (1<<15) /* allow async directory ops */
> > > +#define CEPH_MOUNT_OPT_NO_SHARE_SB     (1<<16) /* disable sharing the same superblock */
> > >   
> > >   #define CEPH_MOUNT_OPT_DEFAULT			\
> > >   	(CEPH_MOUNT_OPT_DCACHE |		\
> 
>
Xiubo Li Oct. 14, 2020, 10:19 a.m. UTC | #4 
On 2020/10/13 21:41, Jeff Layton wrote:
> On Tue, 2020-10-13 at 20:44 +0800, Xiubo Li wrote:

>> On 2020/10/13 20:31, Jeff Layton wrote:

>>> On Tue, 2020-10-13 at 18:31 +0800, xiubli@redhat.com wrote:

>>>> From: Xiubo Li <xiubli@redhat.com>

>>>>

>>>> This will disable different mount points to share superblocks.

>>>>

>>> Why? What problem does this solve? Don't make us dig through random

>>> tracker bugs to determine this, please. :)

>> So, should we just mannully trigger to crash the kernel to get the

>> coredump ?

>>

> Looking at the tracker ticket, it looks like you want this to work

> around some issues with lazy unmounts in tests.  If so, then sure,

> forcing a coredump might give you an indication of what happened.

>

> In general though, this sounds like a hacky workaround for the problem

> in that tracker. I suggest we don't do this and work toward solving the

> real problems that caused the test writers to use lazy umounts in the

> first place...


Okay, will try this.

Thanks.


>>> Also, the subject mentions a "noshare" mount option, but the code below

>>> will be expecting sharesb/nosharesb.

>>>

>>>> URL: https://tracker.ceph.com/issues/46883

>>>> Signed-off-by: Xiubo Li <xiubli@redhat.com>

>>>> ---

>>>>    fs/ceph/super.c | 12 ++++++++++++

>>>>    fs/ceph/super.h |  1 +

>>>>    2 files changed, 13 insertions(+)

>>>>

>>>> diff --git a/fs/ceph/super.c b/fs/ceph/super.c

>>>> index 2f530a111b3a..6f283e4d62ee 100644

>>>> --- a/fs/ceph/super.c

>>>> +++ b/fs/ceph/super.c

>>>> @@ -159,6 +159,7 @@ enum {

>>>>    	Opt_quotadf,

>>>>    	Opt_copyfrom,

>>>>    	Opt_wsync,

>>>> +	Opt_sharesb,

>>>>    };

>>>>    

>>>>    enum ceph_recover_session_mode {

>>>> @@ -199,6 +200,7 @@ static const struct fs_parameter_spec ceph_mount_parameters[] = {

>>>>    	fsparam_string	("source",			Opt_source),

>>>>    	fsparam_u32	("wsize",			Opt_wsize),

>>>>    	fsparam_flag_no	("wsync",			Opt_wsync),

>>>> +	fsparam_flag_no	("sharesb",			Opt_sharesb),

>>>>    	{}

>>>>    };

>>>>    

>>>> @@ -455,6 +457,12 @@ static int ceph_parse_mount_param(struct fs_context *fc,

>>>>    		else

>>>>    			fsopt->flags |= CEPH_MOUNT_OPT_ASYNC_DIROPS;

>>>>    		break;

>>>> +	case Opt_sharesb:

>>>> +		if (!result.negated)

>>>> +			fsopt->flags &= ~CEPH_MOUNT_OPT_NO_SHARE_SB;

>>>> +		else

>>>> +			fsopt->flags |= CEPH_MOUNT_OPT_NO_SHARE_SB;

>>>> +		break;

>>>>    	default:

>>>>    		BUG();

>>>>    	}

>>>> @@ -1007,6 +1015,10 @@ static int ceph_compare_super(struct super_block *sb, struct fs_context *fc)

>>>>    

>>>>    	dout("ceph_compare_super %p\n", sb);

>>>>    

>>>> +	if (fsopt->flags & CEPH_MOUNT_OPT_NO_SHARE_SB ||

>>>> +	    other->mount_options->flags & CEPH_MOUNT_OPT_NO_SHARE_SB)

>>>> +		return 0;

>>>> +

>>>>    	if (compare_mount_options(fsopt, opt, other)) {

>>>>    		dout("monitor(s)/mount options don't match\n");

>>>>    		return 0;

>>>> diff --git a/fs/ceph/super.h b/fs/ceph/super.h

>>>> index f097237a5ad3..e877c21196e5 100644

>>>> --- a/fs/ceph/super.h

>>>> +++ b/fs/ceph/super.h

>>>> @@ -44,6 +44,7 @@

>>>>    #define CEPH_MOUNT_OPT_NOQUOTADF       (1<<13) /* no root dir quota in statfs */

>>>>    #define CEPH_MOUNT_OPT_NOCOPYFROM      (1<<14) /* don't use RADOS 'copy-from' op */

>>>>    #define CEPH_MOUNT_OPT_ASYNC_DIROPS    (1<<15) /* allow async directory ops */

>>>> +#define CEPH_MOUNT_OPT_NO_SHARE_SB     (1<<16) /* disable sharing the same superblock */

>>>>    

>>>>    #define CEPH_MOUNT_OPT_DEFAULT			\

>>>>    	(CEPH_MOUNT_OPT_DCACHE |		\

>>
diff mbox series

Patch

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 2f530a111b3a..6f283e4d62ee 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -159,6 +159,7 @@  enum {
 	Opt_quotadf,
 	Opt_copyfrom,
 	Opt_wsync,
+	Opt_sharesb,
 };
 
 enum ceph_recover_session_mode {
@@ -199,6 +200,7 @@  static const struct fs_parameter_spec ceph_mount_parameters[] = {
 	fsparam_string	("source",			Opt_source),
 	fsparam_u32	("wsize",			Opt_wsize),
 	fsparam_flag_no	("wsync",			Opt_wsync),
+	fsparam_flag_no	("sharesb",			Opt_sharesb),
 	{}
 };
 
@@ -455,6 +457,12 @@  static int ceph_parse_mount_param(struct fs_context *fc,
 		else
 			fsopt->flags |= CEPH_MOUNT_OPT_ASYNC_DIROPS;
 		break;
+	case Opt_sharesb:
+		if (!result.negated)
+			fsopt->flags &= ~CEPH_MOUNT_OPT_NO_SHARE_SB;
+		else
+			fsopt->flags |= CEPH_MOUNT_OPT_NO_SHARE_SB;
+		break;
 	default:
 		BUG();
 	}
@@ -1007,6 +1015,10 @@  static int ceph_compare_super(struct super_block *sb, struct fs_context *fc)
 
 	dout("ceph_compare_super %p\n", sb);
 
+	if (fsopt->flags & CEPH_MOUNT_OPT_NO_SHARE_SB ||
+	    other->mount_options->flags & CEPH_MOUNT_OPT_NO_SHARE_SB)
+		return 0;
+
 	if (compare_mount_options(fsopt, opt, other)) {
 		dout("monitor(s)/mount options don't match\n");
 		return 0;
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index f097237a5ad3..e877c21196e5 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -44,6 +44,7 @@ 
 #define CEPH_MOUNT_OPT_NOQUOTADF       (1<<13) /* no root dir quota in statfs */
 #define CEPH_MOUNT_OPT_NOCOPYFROM      (1<<14) /* don't use RADOS 'copy-from' op */
 #define CEPH_MOUNT_OPT_ASYNC_DIROPS    (1<<15) /* allow async directory ops */
+#define CEPH_MOUNT_OPT_NO_SHARE_SB     (1<<16) /* disable sharing the same superblock */
 
 #define CEPH_MOUNT_OPT_DEFAULT			\
 	(CEPH_MOUNT_OPT_DCACHE |		\