fsstress: add splice support

Support the splice syscall in fsstress.

Signed-off-by Zorro Lang <[email protected]>

---
 ltp/fsstress.c | 144 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 144 insertions(+)

ltp/fsstress.c +95 -0

index 99a1d733..cdf73026 100644
@@ -85,6 +85,7 @@ typedef enum {
 	OP_RMDIR,
 	OP_SETATTR,
 	OP_SETXATTR,
+	OP_SPLICE,
 	OP_STAT,
 	OP_SYMLINK,
 	OP_SYNC,

@@ -194,6 +195,7 @@ void	resvsp_f(int, long);
 void	rmdir_f(int, long);
 void	setattr_f(int, long);
 void	setxattr_f(int, long);
+void	splice_f(int, long);
 void	stat_f(int, long);
 void	symlink_f(int, long);
 void	sync_f(int, long);

@@ -244,6 +246,7 @@ opdesc_t	ops[] = {
 	{ OP_RMDIR, "rmdir", rmdir_f, 1, 1 },
 	{ OP_SETATTR, "setattr", setattr_f, 0, 1 },
 	{ OP_SETXATTR, "setxattr", setxattr_f, 1, 1 },
+	{ OP_SPLICE, "splice", splice_f, 1, 1 },
 	{ OP_STAT, "stat", stat_f, 1, 0 },
 	{ OP_SYMLINK, "symlink", symlink_f, 2, 1 },
 	{ OP_SYNC, "sync", sync_f, 1, 1 },

@@ -2764,6 +2767,147 @@ setxattr_f(int opno, long r)
 #endif
 }
 
+void
+splice_f(int opno, long r)
+{
+	struct pathname		fpath1;
+	struct pathname		fpath2;
+	struct stat64		stat1;
+	struct stat64		stat2;
+	char			inoinfo1[1024];
+	char			inoinfo2[1024];
+	loff_t			lr;
+	loff_t			off1;
+	loff_t			off2;
+	size_t			len;
+	size_t			total;
+	int			v1;
+	int			v2;
+	int			fd1;
+	int			fd2;
+	size_t			ret;
+	int			e;
+	int			filedes[2];
+
+	/* Load paths */
+	init_pathname(&fpath1);
+	if (!get_fname(FT_REGm, r, &fpath1, NULL, NULL, &v1)) {
+		if (v1)
+			printf("%d/%d: splice 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/%d: splice 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/%d: splice 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/%d: splice 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/%d: splice 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/%d: splice write - fstat64 %s failed %d\n",
+				procid, opno, fpath2.path, errno);
+		goto out_fd2;
+	}
+	inode_info(inoinfo2, sizeof(inoinfo2), &stat2, v2);
+
+	/* Calculate offsets */
+	len = (random() % FILELEN_MAX) + 1;
+	if (len == 0)
+		len = stat1.st_blksize;
+	if (len > stat1.st_size)
+		len = stat1.st_size;
+
+	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;
+
+	if (pipe(filedes) < 0) {

ltp/fsstress.c +17 -0

+			printf(" asked for %lld, copied %lld??\n",
+				(long long)len, (long long)total);
+		printf("\n");
+	}
+
+	close(filedes[0]);
+	close(filedes[1]);
+out_fd2:
+	close(fd2);
+out_fd1:
+	close(fd1);
+out_fpath2:
+	free_pathname(&fpath2);
+out_fpath1:
+	free_pathname(&fpath1);
+}
+
 void
 creat_f(int opno, long r)
 {

Signature · 1 line

2.17.2

Quoted 3 lines · Zorro Lang

Support the splice syscall in fsstress.

Signed-off-by Zorro Lang <[email protected]>

Thanks for adding the new syscall! Some comments inline.

Quoted 128 lines

---
 ltp/fsstress.c | 144 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 144 insertions(+)

ltp/fsstress.c +95 -0

index 99a1d733..cdf73026 100644
@@ -85,6 +85,7 @@ typedef enum {
 	OP_RMDIR,
 	OP_SETATTR,
 	OP_SETXATTR,
+	OP_SPLICE,
 	OP_STAT,
 	OP_SYMLINK,
 	OP_SYNC,

@@ -194,6 +195,7 @@ void	resvsp_f(int, long);
 void	rmdir_f(int, long);
 void	setattr_f(int, long);
 void	setxattr_f(int, long);
+void	splice_f(int, long);
 void	stat_f(int, long);
 void	symlink_f(int, long);
 void	sync_f(int, long);

@@ -244,6 +246,7 @@ opdesc_t	ops[] = {
 	{ OP_RMDIR, "rmdir", rmdir_f, 1, 1 },
 	{ OP_SETATTR, "setattr", setattr_f, 0, 1 },
 	{ OP_SETXATTR, "setxattr", setxattr_f, 1, 1 },
+	{ OP_SPLICE, "splice", splice_f, 1, 1 },
 	{ OP_STAT, "stat", stat_f, 1, 0 },
 	{ OP_SYMLINK, "symlink", symlink_f, 2, 1 },
 	{ OP_SYNC, "sync", sync_f, 1, 1 },

@@ -2764,6 +2767,147 @@ setxattr_f(int opno, long r)
 #endif
 }
 
+void
+splice_f(int opno, long r)
+{
+	struct pathname		fpath1;
+	struct pathname		fpath2;
+	struct stat64		stat1;
+	struct stat64		stat2;
+	char			inoinfo1[1024];
+	char			inoinfo2[1024];
+	loff_t			lr;
+	loff_t			off1;
+	loff_t			off2;
+	size_t			len;
+	size_t			total;
+	int			v1;
+	int			v2;
+	int			fd1;
+	int			fd2;
+	size_t			ret;
+	int			e;
+	int			filedes[2];
+
+	/* Load paths */
+	init_pathname(&fpath1);
+	if (!get_fname(FT_REGm, r, &fpath1, NULL, NULL, &v1)) {
+		if (v1)
+			printf("%d/%d: splice 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/%d: splice 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/%d: splice 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/%d: splice 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/%d: splice 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/%d: splice write - fstat64 %s failed %d\n",
+				procid, opno, fpath2.path, errno);
+		goto out_fd2;
+	}
+	inode_info(inoinfo2, sizeof(inoinfo2), &stat2, v2);
+
+	/* Calculate offsets */
+	len = (random() % FILELEN_MAX) + 1;
+	if (len == 0)
+		len = stat1.st_blksize;
+	if (len > stat1.st_size)
+		len = stat1.st_size;
+
+	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;
+
+	if (pipe(filedes) < 0) {

ltp/fsstress.c setxattr_f(int opno, long r) · line 2871

Quoted 10 lines

ltp/fsstress.c +10 -0

+		if (v1 || v2) {
+			printf("%d/%d: splice - pipe failed %d\n",
+			       procid, opno, errno);
+			goto out_fd2;
+		}
+	}
+
+	while (len > 0) {
+		/* move to pipe buffer */
+		ret = splice(fd1, &off1, filedes[1], NULL, len, 0);

ret is defined as size_t, but splice(2) returns ssize_t, and the return value is casted to size_t and can't be negative.

ltp/fsstress.c setxattr_f(int opno, long r) · line 2874

Quoted 3 lines

ltp/fsstress.c +3 -0

+		if (ret < 0) {
+			break;
+		}

So this will never be true.

ltp/fsstress.c setxattr_f(int opno, long r) · line 2876

Quoted 2 lines

ltp/fsstress.c +2 -0

+		/* move from pipe buffer to dst file */
+		ret = splice(filedes[0], NULL, fd2, &off2, len, 0);

We should splice 'ret' bytes as the length not 'len' here, otherwise we may request to splice more data to fd2 than the pipe actually holds and block on reading the pipe. I can hit fsstress 'hang' occasionally.

Also, off2 is used without being initialized.

ltp/fsstress.c setxattr_f(int opno, long r) · line 2889

Quoted 13 lines

ltp/fsstress.c +13 -0

+		if (ret < 0) {
+			break;
+		}
+                len -= ret;
+                total += ret;
+	}
+
+	e = ret < 0 ? errno : 0;
+	if (v1 || v2) {
+		printf("%d/%d: splice %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);

The values of off1 and off2 have been updated by splice(2) calls, and are not the initial value we requested. And 'len' is always '0' here as it's been adjusted in above while loop as well.

ltp/fsstress.c setxattr_f(int opno, long r) · line 2892

Quoted 3 lines

ltp/fsstress.c +3 -0

+
+		if (ret < 0)
+			printf(" error %d", e);

Always print out errno even if it's 0 (and 'error' can be omitted), as other operations do.

ltp/fsstress.c setxattr_f(int opno, long r) · line 2893

Quoted 1 line

ltp/fsstress.c +1 -0

+		else if (len && ret > len)

Same here, 'len' is 0 and the if can never be true.

Thanks,
Eryu

Quoted 23 lines

ltp/fsstress.c +17 -0

+			printf(" asked for %lld, copied %lld??\n",
+				(long long)len, (long long)total);
+		printf("\n");
+	}
+
+	close(filedes[0]);
+	close(filedes[1]);
+out_fd2:
+	close(fd2);
+out_fd1:
+	close(fd1);
+out_fpath2:
+	free_pathname(&fpath2);
+out_fpath1:
+	free_pathname(&fpath1);
+}
+
 void
 creat_f(int opno, long r)
 {

Signature · 1 line

2.17.2