fsstress: add splice support

Support the splice syscall in fsstress.

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

---
 ltp/fsstress.c | 173 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 173 insertions(+)

ltp/fsstress.c +90 -0

index 99a1d733..c04feb78 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 +2767,176 @@ 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, off2;
+	size_t			len;
+	loff_t			offset1, offset2;
+	size_t			length;
+	size_t			total;
+	int			v1;
+	int			v2;
+	int			fd1;
+	int			fd2;
+	ssize_t			ret1 = 0, ret2 = 0;
+	size_t			bytes;
+	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();

ltp/fsstress.c +71 -0

+
+	/*
+	 * Due to len, off1 and off2 will be changed later, so record the
+	 * original number at here
+	 */
+	length = len;
+	offset1 = off1;
+	offset2 = off2;
+
+	/* Pipe initialize */
+	if (pipe(filedes) < 0) {
+		if (v1 || v2) {
+			printf("%d/%d: splice - pipe failed %d\n",
+				procid, opno, errno);
+			goto out_fd2;
+		}
+	}
+
+	bytes = 0;
+	total = 0;
+	while (len > 0) {
+		/* move to pipe buffer */
+		ret1 = splice(fd1, &off1, filedes[1], NULL, len, 0);
+		if (ret1 < 0) {
+			break;
+		}
+		bytes = ret1;
+
+		/* move from pipe buffer to dst file */
+		while (bytes > 0) {
+			ret2 = splice(filedes[0], NULL, fd2, &off2, bytes, 0);
+			if (ret2 < 0) {
+				break;
+			}
+			bytes -= ret2;
+		}
+		if (ret2 < 0)
+			break;
+
+		len -= ret1;
+		total += ret1;
+	}
+
+	if (ret1 < 0 || ret2 < 0)
+		e = errno;
+	else
+		e = 0;
+	if (v1 || v2) {
+		printf("%d/%d: splice %s%s [%lld,%lld] -> %s%s [%lld,%lld] %d",
+			procid, opno,
+			fpath1.path, inoinfo1, (long long)offset1, (long long)length,
+			fpath2.path, inoinfo2, (long long)offset2, (long long)length, e);
+
+		if (length && length > total)
+			printf(" asked for %lld, spliced %lld??\n",
+				(long long)length, (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 126 lines · Zorro Lang

Support the splice syscall in fsstress.

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

---
 ltp/fsstress.c | 173 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 173 insertions(+)

ltp/fsstress.c +90 -0

index 99a1d733..c04feb78 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 +2767,176 @@ 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, off2;
+	size_t			len;
+	loff_t			offset1, offset2;
+	size_t			length;
+	size_t			total;
+	int			v1;
+	int			v2;
+	int			fd1;
+	int			fd2;
+	ssize_t			ret1 = 0, ret2 = 0;
+	size_t			bytes;
+	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();

ltp/fsstress.c setxattr_f(int opno, long r) · line 2866

Quoted 10 lines

ltp/fsstress.c +10 -0

+	if (stat1.st_size == len)
+		off1 = 0;
+	else
+		off1 = (off64_t)(lr % MIN(stat1.st_size - len, MAXFSIZE));
+	off1 %= maxfsize;
+
+	/*
+	 * splice can overlap write, so the offset of the target file can be
+	 * any number (< maxfsize)
+	 */

Er... sorry I've been offline for a couple of weeks due to illness and so was not able to comment on this patch until now, but I've had a problem with my overnight fstests runs:

ltp/fsstress.c setxattr_f(int opno, long r) · line 2867

Quoted 1 line

ltp/fsstress.c +1 -0

+	lr = ((int64_t)random() << 32) + random();

This generates a pseudorandom 64-bit candidate offset for the destination file where we'll land the splice data...

ltp/fsstress.c setxattr_f(int opno, long r) · line 2868

Quoted 1 line

ltp/fsstress.c +1 -0

+	off2 = (off64_t)(lr % maxfsize);

...and this caps the offset at maxfsize (which is 2^63- 1 on x64), which
effectively means that the data will appear at a very high file offset, which creates large (sparse) files very quickly.

Contrast this to other functions like clonerange_f, which add an additional clamp of 1024 blocks past the current dest file EOF:

max_off2 = MIN(stat2.st_size + (1024ULL * stat2.st_blksize), MAXFSIZE);

 do {
	lr = ((int64_t)random() << 32) + random();
	off2 = (off64_t)(lr % max_off2);
	off2 %= maxfsize;
	...

}

or truncate_f, which clamps to both 1MB past EOF and MAXFSIZE:

lr = ((int64_t)random() << 32) + random();
off = (off64_t)(lr % MIN(stb.st_size + (1024 * 1024), MAXFSIZE)); off %= maxfsize;

IOWs, I think we try to grow the fsstress file sizes fairly slowly so that gigantic files don't suddenly jump out of the bushes:

0/487: splice d3/d9/f2c[6319385 1 0 0 176 1395200] [860317,88612] -> d3/d9/dd/d1c/d21/f4b[1111 1 0 0 0 1408811] [8492675175361853476,88612] 0

Yikes, it wrote 88,612 bytes of data at offset 8,492,675,175,361,853,476!

This causes shared/009 to take forever to run, because it runs fsstress to generate some files, and then uses md5sum to ensure that duperemove doesn't corrupt files. Unfortunately it takes a very long time to read an entire 8500 petabyte file.

--D

Quoted 77 lines

ltp/fsstress.c +71 -0

+
+	/*
+	 * Due to len, off1 and off2 will be changed later, so record the
+	 * original number at here
+	 */
+	length = len;
+	offset1 = off1;
+	offset2 = off2;
+
+	/* Pipe initialize */
+	if (pipe(filedes) < 0) {
+		if (v1 || v2) {
+			printf("%d/%d: splice - pipe failed %d\n",
+				procid, opno, errno);
+			goto out_fd2;
+		}
+	}
+
+	bytes = 0;
+	total = 0;
+	while (len > 0) {
+		/* move to pipe buffer */
+		ret1 = splice(fd1, &off1, filedes[1], NULL, len, 0);
+		if (ret1 < 0) {
+			break;
+		}
+		bytes = ret1;
+
+		/* move from pipe buffer to dst file */
+		while (bytes > 0) {
+			ret2 = splice(filedes[0], NULL, fd2, &off2, bytes, 0);
+			if (ret2 < 0) {
+				break;
+			}
+			bytes -= ret2;
+		}
+		if (ret2 < 0)
+			break;
+
+		len -= ret1;
+		total += ret1;
+	}
+
+	if (ret1 < 0 || ret2 < 0)
+		e = errno;
+	else
+		e = 0;
+	if (v1 || v2) {
+		printf("%d/%d: splice %s%s [%lld,%lld] -> %s%s [%lld,%lld] %d",
+			procid, opno,
+			fpath1.path, inoinfo1, (long long)offset1, (long long)length,
+			fpath2.path, inoinfo2, (long long)offset2, (long long)length, e);
+
+		if (length && length > total)
+			printf(" asked for %lld, spliced %lld??\n",
+				(long long)length, (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