Re: [PATCH 7/7] fsstress: update for FIEXCHANGE_RANGE

["Darrick J. Wong" <djwong@kernel.org>]

On Thu, Mar 02, 2023 at 05:42:06PM +0800, Zorro Lang wrote:
> On Tue, Feb 28, 2023 at 06:59:43PM -0800, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@kernel.org>
> > 
> > Teach this stress tool to be able to use the file content exchange
> > ioctl.
> > 
> > Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> > ---
> >  ltp/fsstress.c |  168 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 168 insertions(+)
> > 
> > 
> > diff --git a/ltp/fsstress.c b/ltp/fsstress.c
> > index 10608fb554..0fba3d92a0 100644
> > --- a/ltp/fsstress.c
> > +++ b/ltp/fsstress.c
> > @@ -143,6 +143,7 @@ typedef enum {
> >  	OP_URING_WRITE,
> >  	OP_WRITE,
> >  	OP_WRITEV,
> > +	OP_XCHGRANGE,
> >  	OP_LAST
> >  } opty_t;
> >  
> > @@ -272,6 +273,8 @@ void	uring_read_f(opnum_t, long);
> >  void	uring_write_f(opnum_t, long);
> >  void	write_f(opnum_t, long);
> >  void	writev_f(opnum_t, long);
> > +void	xchgrange_f(opnum_t, long);
> > +
> >  char	*xattr_flag_to_string(int);
> >  
> >  struct opdesc	ops[OP_LAST]	= {
> > @@ -340,6 +343,7 @@ struct opdesc	ops[OP_LAST]	= {
> >  	[OP_URING_WRITE]   = {"uring_write",   uring_write_f,	1, 1 },
> >  	[OP_WRITE]	   = {"write",	       write_f,		4, 1 },
> >  	[OP_WRITEV]	   = {"writev",	       writev_f,	4, 1 },
> > +	[OP_XCHGRANGE]	   = {"xchgrange",     xchgrange_f,	4, 1 },
> 
> Do you think this is a common operation which should use same frequency (4)
> with read/write operations? I'd like to reduce the default freq=4 to 2 or 1
> when I merge it. what do you think?

Sounds fine to me, I copy-pasted the 4 from the line above.  :)

--D

> Thanks,
> Zorro
> 
> >  }, *ops_end;
> >  
> >  flist_t	flist[FT_nft] = {
> > @@ -2494,6 +2498,170 @@ chown_f(opnum_t opno, long r)
> >  	free_pathname(&f);
> >  }
> >  
> > +/* exchange some arbitrary range of f1 to f2...fn. */
> > +void
> > +xchgrange_f(
> > +	opnum_t			opno,
> > +	long			r)
> > +{
> > +#ifdef FIEXCHANGE_RANGE
> > +	struct file_xchg_range	fxr = { 0 };
> > +	static __u64		swap_flags = 0;
> > +	struct pathname		fpath1;
> > +	struct pathname		fpath2;
> > +	struct stat64		stat1;
> > +	struct stat64		stat2;
> > +	char			inoinfo1[1024];
> > +	char			inoinfo2[1024];
> > +	off64_t			lr;
> > +	off64_t			off1;
> > +	off64_t			off2;
> > +	off64_t			max_off2;
> > +	size_t			len;
> > +	int			v1;
> > +	int			v2;
> > +	int			fd1;
> > +	int			fd2;
> > +	int			ret;
> > +	int			tries = 0;
> > +	int			e;
> > +
> > +	/* Load paths */
> > +	init_pathname(&fpath1);
> > +	if (!get_fname(FT_REGm, r, &fpath1, NULL, NULL, &v1)) {
> > +		if (v1)
> > +			printf("%d/%lld: xchgrange read - no filename\n",
> > +				procid, opno);
> > +		goto out_fpath1;
> > +	}
> > +
> > +	init_pathname(&fpath2);
> > +	if (!get_fname(FT_REGm, random(), &fpath2, NULL, NULL, &v2)) {
> > +		if (v2)
> > +			printf("%d/%lld: xchgrange write - no filename\n",
> > +				procid, opno);
> > +		goto out_fpath2;
> > +	}
> > +
> > +	/* Open files */
> > +	fd1 = open_path(&fpath1, O_RDONLY);
> > +	e = fd1 < 0 ? errno : 0;
> > +	check_cwd();
> > +	if (fd1 < 0) {
> > +		if (v1)
> > +			printf("%d/%lld: xchgrange read - open %s failed %d\n",
> > +				procid, opno, fpath1.path, e);
> > +		goto out_fpath2;
> > +	}
> > +
> > +	fd2 = open_path(&fpath2, O_WRONLY);
> > +	e = fd2 < 0 ? errno : 0;
> > +	check_cwd();
> > +	if (fd2 < 0) {
> > +		if (v2)
> > +			printf("%d/%lld: xchgrange write - open %s failed %d\n",
> > +				procid, opno, fpath2.path, e);
> > +		goto out_fd1;
> > +	}
> > +
> > +	/* Get file stats */
> > +	if (fstat64(fd1, &stat1) < 0) {
> > +		if (v1)
> > +			printf("%d/%lld: xchgrange read - fstat64 %s failed %d\n",
> > +				procid, opno, fpath1.path, errno);
> > +		goto out_fd2;
> > +	}
> > +	inode_info(inoinfo1, sizeof(inoinfo1), &stat1, v1);
> > +
> > +	if (fstat64(fd2, &stat2) < 0) {
> > +		if (v2)
> > +			printf("%d/%lld: xchgrange write - fstat64 %s failed %d\n",
> > +				procid, opno, fpath2.path, errno);
> > +		goto out_fd2;
> > +	}
> > +	inode_info(inoinfo2, sizeof(inoinfo2), &stat2, v2);
> > +
> > +	if (stat1.st_size < (stat1.st_blksize * 2) ||
> > +	    stat2.st_size < (stat2.st_blksize * 2)) {
> > +		if (v2)
> > +			printf("%d/%lld: xchgrange - files are too small\n",
> > +				procid, opno);
> > +		goto out_fd2;
> > +	}
> > +
> > +	/* Never let us swap more than 1/4 of the files. */
> > +	len = (random() % FILELEN_MAX) + 1;
> > +	if (len > stat1.st_size / 4)
> > +		len = stat1.st_size / 4;
> > +	if (len > stat2.st_size / 4)
> > +		len = stat2.st_size / 4;
> > +	len = rounddown_64(len, stat1.st_blksize);
> > +	if (len == 0)
> > +		len = stat1.st_blksize;
> > +
> > +	/* Calculate offsets */
> > +	lr = ((int64_t)random() << 32) + random();
> > +	if (stat1.st_size == len)
> > +		off1 = 0;
> > +	else
> > +		off1 = (off64_t)(lr % MIN(stat1.st_size - len, MAXFSIZE));
> > +	off1 %= maxfsize;
> > +	off1 = rounddown_64(off1, stat1.st_blksize);
> > +
> > +	/*
> > +	 * If srcfile == destfile, randomly generate destination ranges
> > +	 * until we find one that doesn't overlap the source range.
> > +	 */
> > +	max_off2 = MIN(stat2.st_size  - len, MAXFSIZE);
> > +	do {
> > +		lr = ((int64_t)random() << 32) + random();
> > +		if (stat2.st_size == len)
> > +			off2 = 0;
> > +		else
> > +			off2 = (off64_t)(lr % max_off2);
> > +		off2 %= maxfsize;
> > +		off2 = rounddown_64(off2, stat2.st_blksize);
> > +	} while (stat1.st_ino == stat2.st_ino &&
> > +		 llabs(off2 - off1) < len &&
> > +		 tries++ < 10);
> > +
> > +	/* Swap data blocks */
> > +	fxr.file1_fd = fd1;
> > +	fxr.file1_offset = off1;
> > +	fxr.length = len;
> > +	fxr.file2_offset = off2;
> > +	fxr.flags = swap_flags;
> > +
> > +retry:
> > +	ret = ioctl(fd2, FIEXCHANGE_RANGE, &fxr);
> > +	e = ret < 0 ? errno : 0;
> > +	if (e == EOPNOTSUPP && !(swap_flags & FILE_XCHG_RANGE_NONATOMIC)) {
> > +		swap_flags = FILE_XCHG_RANGE_NONATOMIC;
> > +		fxr.flags |= swap_flags;
> > +		goto retry;
> > +	}
> > +	if (v1 || v2) {
> > +		printf("%d/%lld: xchgrange %s%s [%lld,%lld] -> %s%s [%lld,%lld]",
> > +			procid, opno,
> > +			fpath1.path, inoinfo1, (long long)off1, (long long)len,
> > +			fpath2.path, inoinfo2, (long long)off2, (long long)len);
> > +
> > +		if (ret < 0)
> > +			printf(" error %d", e);
> > +		printf("\n");
> > +	}
> > +
> > +out_fd2:
> > +	close(fd2);
> > +out_fd1:
> > +	close(fd1);
> > +out_fpath2:
> > +	free_pathname(&fpath2);
> > +out_fpath1:
> > +	free_pathname(&fpath1);
> > +#endif
> > +}
> > +
> >  /* reflink some arbitrary range of f1 to f2. */
> >  void
> >  clonerange_f(
> > 
>