Re: [PATCH v5 06/10] xfs: add XFS_IOC_FREE_EOFBLOCKS ioctl

Brian Foster
2012-10-18T12:13:35Z

[-- Attachment #1: Type: text/plain, Size: 2192 bytes --]

On 10/17/2012 06:40 PM, Ben Myers wrote:
> Hi Fellas,
>
> On Tue, Oct 16, 2012 at 12:39:01PM +1100, Dave Chinner wrote:
>> On Tue, Oct 16, 2012 at 10:49:02AM +1100, Dave Chinner wrote:
>>> On Mon, Oct 15, 2012 at 05:46:26PM -0500, Ben Myers wrote:
>>>> Hey Brian,
>>>>
...
>>>> I do think it is preferable to have a test case go in with the code where
>>>> possible. Since you don't mind waiting a bit, that seems to be the way to go.
>>>> The other option could be to look for a volunteer to work on the test. ;)
>>>
>>> FWIW, given the background cleanup code can be trivially verified to
>>> work (open, apend, close, repeat, wait 5 minutes) and is the
>>> functionality that is needed in mainline, having something to test
>>> the ioctls should not stop the patchset from being merged.
>
> Can we be assured that we'll get an xfstest for it eventually?
>

Absolutely. Getting a command into xfs_io to support such a test is now
the top of my todo list with regard to XFS. :)

> I think we can pull this in if Brian is willing post his test code. Initially
> it needn't be posted as an xfstest, that's fine. As it stands today it appears
> that Brian is the only one to ever use the ioctl and there is no way for anyone
> else to test it. Not an ideal situation.
>

The impetus for this work was some prototype quota work for the gluster
distributed filesystem. Beyond testing via that, I just had a very
simple/stupid program with the command and data structure bits
copy/pasted in to open a file and invoke an xfsctl() with hardcoded
parameters. I don't consider it post-worthy or very useful, but attached
nonetheless since I have a couple things to deal with before I get a
chance to play with xfs_io.

> I think this is a reasonable request. Usually it's Christoph who asks for a
> test case. ;)
>

Agree.

Brian

>> i.e.:
>>
>> $ for i in `seq 0 512`; do
>>> xfs_io -f -c "pwrite $((i * 4096)) 4096" /mnt/scratch/foo
>>> done
>> $ stat -c %b /mnt/scratch/foo
>> 8192
>> $ sync; stat -c %b /mnt/scratch/foo
>> 8192
>> $ sleep 30; stat -c %b /mnt/scratch/foo
>> 8192
>> $ sleep 300; stat -c %b /mnt/scratch/foo
>> 4104
>>
>> It works. ;)
>
> Nice!
>
> Regards,
> Ben
>

[-- Attachment #2: free_eofblocks.c --]
[-- Type: text/x-csrc, Size: 1483 bytes --]

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <xfs/xfs.h>

#include <sys/quota.h>
#ifndef PRJQUOTA
#define PRJQUOTA 2
#endif

/*
* Speculative preallocation trimming.
*/
#define XFS_EOFBLOCKS_VERSION 1
struct xfs_eofblocks {
__s32 eof_version;
__u32 eof_flags;
__u32 eof_q_id;
__u32 eof_q_type;
__u32 eof_min_file_size;
unsigned char pad[12];
};

/* eof_flags values */
#define XFS_EOF_FLAGS_SYNC 0x01 /* sync/wait mode scan */
#define XFS_EOF_FLAGS_QUOTA 0x02 /* filter by quota id */
#define XFS_EOF_FLAGS_MINFILESIZE 0x04 /* filter by min file size */

#define XFS_IOC_FREE_EOFBLOCKS _IOR ('X', 58, struct xfs_eofblocks)

int main(int argc, char *argv[])
{
int ret, fd;
struct xfs_eofblocks eofb;

fd = open(argv[1], O_RDONLY);
if (fd < 0) {
perror("open");
return -1;
}

memset(&eofb, 0, sizeof(struct xfs_eofblocks));

eofb.eof_version = XFS_EOFBLOCKS_VERSION;
eofb.eof_flags |= XFS_EOF_FLAGS_SYNC;
//eofb.eof_flags |= XFS_EOF_FLAGS_QUOTA;
//eofb.eof_q_id = 42;
//eofb.eof_q_type = PRJQUOTA;
eofb.eof_flags |= XFS_EOF_FLAGS_MINFILESIZE;
eofb.eof_min_file_size = 1024 * 1024 * 101;
ret = xfsctl(NULL, fd, XFS_IOC_FREE_EOFBLOCKS, &eofb);
if (ret < 0)
perror("xfsctl");

if (close(fd) < 0)
perror("close");

return 0;
}

[-- Attachment #3: Type: text/plain, Size: 121 bytes --]