Re: [PATCH] fsstress: add renameat2 support

[kaixuxia <xiakaixu1987@gmail.com>]

According to the comments, after adding this fsstress renameat2 support,
the deadlock between the AGI and AGF with RENAME_WHITEOUT can be reproduced
by using customized parameters(limited to rename_whiteout and creates). If
this patch is okay, I will send the fsstress test patch. 
So, Eryu, Brian, comments? 

On 2019/10/11 15:56, kaixuxia wrote:
> Support the renameat2 syscall in fsstress.
> 
> Signed-off-by: kaixuxia <kaixuxia@tencent.com>
> ---
>  ltp/fsstress.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++-------
>  1 file changed, 79 insertions(+), 11 deletions(-)
> 
> diff --git a/ltp/fsstress.c b/ltp/fsstress.c
> index 51976f5..21529a2 100644
> --- a/ltp/fsstress.c
> +++ b/ltp/fsstress.c
> @@ -44,6 +44,16 @@ io_context_t	io_ctx;
>  #define IOV_MAX 1024
>  #endif
>  
> +#ifndef RENAME_NOREPLACE
> +#define RENAME_NOREPLACE	(1 << 0)	/* Don't overwrite target */
> +#endif
> +#ifndef RENAME_EXCHANGE
> +#define RENAME_EXCHANGE		(1 << 1)	/* Exchange source and dest */
> +#endif
> +#ifndef RENAME_WHITEOUT
> +#define RENAME_WHITEOUT		(1 << 2)	/* Whiteout source */
> +#endif
> +
>  #define FILELEN_MAX		(32*4096)
>  
>  typedef enum {
> @@ -85,6 +95,9 @@ typedef enum {
>  	OP_READV,
>  	OP_REMOVEFATTR,
>  	OP_RENAME,
> +	OP_RNOREPLACE,
> +	OP_REXCHANGE,
> +	OP_RWHITEOUT,
>  	OP_RESVSP,
>  	OP_RMDIR,
>  	OP_SETATTR,
> @@ -203,6 +216,9 @@ void	readlink_f(int, long);
>  void	readv_f(int, long);
>  void	removefattr_f(int, long);
>  void	rename_f(int, long);
> +void    rnoreplace_f(int, long);
> +void    rexchange_f(int, long);
> +void    rwhiteout_f(int, long);
>  void	resvsp_f(int, long);
>  void	rmdir_f(int, long);
>  void	setattr_f(int, long);
> @@ -262,6 +278,9 @@ opdesc_t	ops[] = {
>  	/* remove (delete) extended attribute */
>  	{ OP_REMOVEFATTR, "removefattr", removefattr_f, 1, 1 },
>  	{ OP_RENAME, "rename", rename_f, 2, 1 },
> +	{ OP_RNOREPLACE, "rnoreplace", rnoreplace_f, 2, 1 },
> +	{ OP_REXCHANGE, "rexchange", rexchange_f, 2, 1 },
> +	{ OP_RWHITEOUT, "rwhiteout", rwhiteout_f, 2, 1 },
>  	{ OP_RESVSP, "resvsp", resvsp_f, 1, 1 },
>  	{ OP_RMDIR, "rmdir", rmdir_f, 1, 1 },
>  	/* set attribute flag (FS_IOC_SETFLAGS ioctl) */
> @@ -354,7 +373,7 @@ int	open_path(pathname_t *, int);
>  DIR	*opendir_path(pathname_t *);
>  void	process_freq(char *);
>  int	readlink_path(pathname_t *, char *, size_t);
> -int	rename_path(pathname_t *, pathname_t *);
> +int	rename_path(pathname_t *, pathname_t *, int);
>  int	rmdir_path(pathname_t *);
>  void	separate_pathname(pathname_t *, char *, pathname_t *);
>  void	show_ops(int, char *);
> @@ -1519,7 +1538,7 @@ readlink_path(pathname_t *name, char *lbuf, size_t lbufsiz)
>  }
>  
>  int
> -rename_path(pathname_t *name1, pathname_t *name2)
> +rename_path(pathname_t *name1, pathname_t *name2, int mode)
>  {
>  	char		buf1[NAME_MAX + 1];
>  	char		buf2[NAME_MAX + 1];
> @@ -1528,14 +1547,14 @@ rename_path(pathname_t *name1, pathname_t *name2)
>  	pathname_t	newname2;
>  	int		rval;
>  
> -	rval = rename(name1->path, name2->path);
> +	rval = syscall(__NR_renameat2, AT_FDCWD, name1->path, AT_FDCWD, name2->path, mode);
>  	if (rval >= 0 || errno != ENAMETOOLONG)
>  		return rval;
>  	separate_pathname(name1, buf1, &newname1);
>  	separate_pathname(name2, buf2, &newname2);
>  	if (strcmp(buf1, buf2) == 0) {
>  		if (chdir(buf1) == 0) {
> -			rval = rename_path(&newname1, &newname2);
> +			rval = rename_path(&newname1, &newname2, mode);
>  			assert(chdir("..") == 0);
>  		}
>  	} else {
> @@ -1555,7 +1574,7 @@ rename_path(pathname_t *name1, pathname_t *name2)
>  			append_pathname(&newname2, "../");
>  			append_pathname(&newname2, name2->path);
>  			if (chdir(buf1) == 0) {
> -				rval = rename_path(&newname1, &newname2);
> +				rval = rename_path(&newname1, &newname2, mode);
>  				assert(chdir("..") == 0);
>  			}
>  		} else {
> @@ -1563,7 +1582,7 @@ rename_path(pathname_t *name1, pathname_t *name2)
>  			append_pathname(&newname1, "../");
>  			append_pathname(&newname1, name1->path);
>  			if (chdir(buf2) == 0) {
> -				rval = rename_path(&newname1, &newname2);
> +				rval = rename_path(&newname1, &newname2, mode);
>  				assert(chdir("..") == 0);
>  			}
>  		}
> @@ -4215,8 +4234,18 @@ out:
>  	free_pathname(&f);
>  }
>  
> +struct print_flags renameat2_flags [] = {
> +	{ RENAME_NOREPLACE, "NOREPLACE"},
> +	{ RENAME_EXCHANGE, "EXCHANGE"},
> +	{ RENAME_WHITEOUT, "WHITEOUT"},
> +	{ -1, NULL}
> +};
> +
> +#define translate_renameat2_flags(mode)	\
> +	({translate_flags(mode, "|", renameat2_flags);})
> +
>  void
> -rename_f(int opno, long r)
> +do_renameat2(int opno, long r, int mode)
>  {
>  	fent_t		*dfep;
>  	int		e;
> @@ -4229,6 +4258,7 @@ rename_f(int opno, long r)
>  	int		parid;
>  	int		v;
>  	int		v1;
> +	int		fd;
>  
>  	/* get an existing path for the source of the rename */
>  	init_pathname(&f);
> @@ -4260,7 +4290,21 @@ rename_f(int opno, long r)
>  		free_pathname(&f);
>  		return;
>  	}
> -	e = rename_path(&f, &newf) < 0 ? errno : 0;
> +	/* Both pathnames must exist for the RENAME_EXCHANGE */
> +	if (mode == RENAME_EXCHANGE) {
> +		fd = creat_path(&newf, 0666);
> +		e = fd < 0 ? errno : 0;
> +		check_cwd();
> +		if (fd < 0) {
> +			if (v)
> +				printf("%d/%d: renameat2 - creat %s failed %d\n",
> +					procid, opno, newf.path, e);
> +			free_pathname(&newf);
> +			free_pathname(&f);
> +			return;
> +		}
> +	}
> +	e = rename_path(&f, &newf, mode) < 0 ? errno : 0;
>  	check_cwd();
>  	if (e == 0) {
>  		int xattr_counter = fep->xattr_counter;
> @@ -4273,12 +4317,13 @@ rename_f(int opno, long r)
>  		add_to_flist(flp - flist, id, parid, xattr_counter);
>  	}
>  	if (v) {
> -		printf("%d/%d: rename %s to %s %d\n", procid, opno, f.path,
> +		printf("%d/%d: rename(%s) %s to %s %d\n", procid,
> +			opno, translate_renameat2_flags(mode), f.path,
>  			newf.path, e);
>  		if (e == 0) {
> -			printf("%d/%d: rename del entry: id=%d,parent=%d\n",
> +			printf("%d/%d: rename source entry: id=%d,parent=%d\n",
>  				procid, opno, fep->id, fep->parent);
> -			printf("%d/%d: rename add entry: id=%d,parent=%d\n",
> +			printf("%d/%d: rename target entry: id=%d,parent=%d\n",
>  				procid, opno, id, parid);
>  		}
>  	}
> @@ -4287,6 +4332,29 @@ rename_f(int opno, long r)
>  }
>  
>  void
> +rename_f(int opno, long r)
> +{
> +	do_renameat2(opno, r, 0);
> +}
> +void
> +rnoreplace_f(int opno, long r)
> +{
> +	do_renameat2(opno, r, RENAME_NOREPLACE);
> +}
> +
> +void
> +rexchange_f(int opno, long r)
> +{
> +	do_renameat2(opno, r, RENAME_EXCHANGE);
> +}
> +
> +void
> +rwhiteout_f(int opno, long r)
> +{
> +	do_renameat2(opno, r, RENAME_WHITEOUT);
> +}
> +
> +void
>  resvsp_f(int opno, long r)
>  {
>  	int		e;
> 

-- 
kaixuxia