[PATCH v2 1/2] fsstress: add splice support

[Zorro Lang <zlang@redhat.com>]

Support the splice syscall in fsstress.

Signed-off-by: Zorro Lang <zlang@redhat.com>
---

Hi,

Thanks Eryu reviewed my v1 patch, this patch has below changes:
1) Set random off2 properly.
2) Improve splice read and write logic (in while loop).
3) Bring in length, offset1 and offset2 for proper output at the end.
4) Judge the return value (ret1 and ret2) properly.

Thanks,
Zorro

 ltp/fsstress.c | 171 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 171 insertions(+)

diff --git a/ltp/fsstress.c b/ltp/fsstress.c
index 99a1d733..e477d0ef 100644
--- a/ltp/fsstress.c
+++ b/ltp/fsstress.c
@@ -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 +2767,174 @@ 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 = MIN(stat1.st_blksize, stat2.st_blksize);
+	if (len > MIN(stat1.st_size, stat2.st_size))
+		len = MIN(stat1.st_size, stat2.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 (stat2.st_size == len)
+		off2 = 0;
+	else
+		off2 = (off64_t)(lr % MIN(stat2.st_size - len, MAXFSIZE));
+	off2 %= maxfsize;
+
+	/*
+	 * 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;
+		}
+		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]",
+			procid, opno,
+			fpath1.path, inoinfo1, (long long)offset1, (long long)length,
+			fpath2.path, inoinfo2, (long long)offset2, (long long)length);
+
+		if (ret1 < 0 || ret2 < 0)
+			printf(" error %d", e);
+		else 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)
 {
-- 
2.17.2