[PATCH 7/7] fsstress: update for FIEXCHANGE_RANGE

From: "Darrick J. Wong" <djwong@kernel.org>
To: djwong@kernel.org, zlang@redhat.com
Cc: linux-xfs@vger.kernel.org, fstests@vger.kernel.org, guan@eryu.me
Subject: [PATCH 7/7] fsstress: update for FIEXCHANGE_RANGE
Date: Tue, 28 Feb 2023 18:59:43 -0800	[thread overview]
Message-ID: <167763958362.3796922.2350291536547146358.stgit@magnolia> (raw)
In-Reply-To: <167763954409.3796922.11086772690906428270.stgit@magnolia>

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 },
 }, *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(

