* [PATCH 1/2] generic/517: expect truthful dedupe progress
2026-08-05 7:18 [PATCH 0/2] fstests: expect and test truthful FIDEDUPERANGE progress Matthias Goergens
@ 2026-08-05 7:18 ` Matthias Goergens
2026-08-11 8:36 ` Zorro Lang
2026-08-05 7:18 ` [PATCH 2/2] generic: test FIDEDUPERANGE result reporting Matthias Goergens
1 sibling, 1 reply; 4+ messages in thread
From: Matthias Goergens @ 2026-08-05 7:18 UTC (permalink / raw)
To: fstests; +Cc: Matthias Goergens, Zorro Lang
The VFS currently reports the requested FIDEDUPERANGE length even when it
shortens the operation to avoid sharing a partial EOF block into the middle
of the destination. Once the kernel reports its actual progress, the first
dedupe in this test reports 131072 of 131172 bytes. xfs_io then retries the
100-byte remainder, which cannot make progress and returns -EINVAL. The
separate 100-byte request returns the same error.
Update the golden output for those truthful results. This is the output
change that caused commit 4a57a8400075 ("vf/remap: return the amount of
bytes actually deduplicated") to be reverted. The paired kernel series that
determines the new output is linked from the cover letter.
The updated test passes on btrfs and XFS with the paired kernel changes.
Signed-off-by: Matthias Goergens <matthias.goergens@gmail.com>
---
tests/generic/517 | 6 ++++++
tests/generic/517.out | 6 +++---
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/tests/generic/517 b/tests/generic/517
index 3f7027a8..ab5d17e7 100755
--- a/tests/generic/517
+++ b/tests/generic/517
@@ -11,6 +11,12 @@
. ./common/preamble
_begin_fstest auto quick dedupe clone
+# The dedupe amounts this test records are only correct once the kernel
+# reports the number of bytes it actually deduplicated rather than the number
+# requested. Both dedupe calls below target a range that does not reach the
+# destination's EOF, so generic_remap_check_len() shortens them under
+# REMAP_FILE_CAN_SHORTEN.
+
# Import common functions.
. ./common/filter
. ./common/reflink
diff --git a/tests/generic/517.out b/tests/generic/517.out
index b9b63207..6ba753d8 100644
--- a/tests/generic/517.out
+++ b/tests/generic/517.out
@@ -13,7 +13,8 @@ File content before first deduplication:
*
0786528 ae ae ae ae
0786532
-deduped 131172/131172 bytes at offset 65536
+XFS_IOC_FILE_EXTENT_SAME: Invalid argument
+deduped 131072/131172 bytes at offset 65536
XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
File content after first deduplication and before unmounting:
0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
@@ -33,8 +34,7 @@ File content after first unmount:
0786532
wrote 100/100 bytes at offset 0
XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-deduped 100/100 bytes at offset 655360
-XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+XFS_IOC_FILE_EXTENT_SAME: Invalid argument
File content after second deduplication:
0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
*
--
2.55.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 2/2] generic: test FIDEDUPERANGE result reporting
2026-08-05 7:18 [PATCH 0/2] fstests: expect and test truthful FIDEDUPERANGE progress Matthias Goergens
2026-08-05 7:18 ` [PATCH 1/2] generic/517: expect truthful dedupe progress Matthias Goergens
@ 2026-08-05 7:18 ` Matthias Goergens
1 sibling, 0 replies; 4+ messages in thread
From: Matthias Goergens @ 2026-08-05 7:18 UTC (permalink / raw)
To: fstests; +Cc: Matthias Goergens, Zorro Lang
xfs_io retries shortened dedupe operations, so its output cannot verify one
raw multi-destination ioctl or distinguish an explicit zero-length request
from a nonzero request shortened to zero.
Add a small FIDEDUPERANGE helper that reports each destination's raw
bytes_deduped and status fields. Use it in generic/806 to check an explicit
zero-length success, a request that is shortened for an interior destination
but remains full-length at EOF, and a sub-block request that returns -EINVAL
for the interior destination while succeeding at EOF.
Compute the request lengths from the filesystem block size so the expected
semantics do not assume 4K blocks. The paired kernel series is linked from
the cover letter.
The test passes on btrfs and XFS with the paired kernel changes.
Signed-off-by: Matthias Goergens <matthias.goergens@gmail.com>
---
src/Makefile | 2 +-
src/fideduperange.c | 138 ++++++++++++++++++++++++++++++++++++++++++
tests/generic/806 | 83 +++++++++++++++++++++++++
tests/generic/806.out | 4 ++
4 files changed, 226 insertions(+), 1 deletion(-)
create mode 100644 src/fideduperange.c
create mode 100755 tests/generic/806
create mode 100644 tests/generic/806.out
diff --git a/src/Makefile b/src/Makefile
index 76cf50c3..e686fe27 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -25,7 +25,7 @@ TARGETS = dirstress fill fill2 getpagesize holes lstat64 \
LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
preallo_rw_pattern_writer ftrunc trunc fs_perms testx looptest \
- locktest unwritten_mmap bulkstat_unlink_test deduperace \
+ locktest unwritten_mmap bulkstat_unlink_test deduperace fideduperange \
bulkstat_unlink_test_modified t_dir_offset t_futimens t_immutable \
stale_handle pwrite_mmap_blocked t_dir_offset2 seek_sanity_test \
seek_copy_test t_readdir_1 t_readdir_2 fsync-tester nsexec cloner \
diff --git a/src/fideduperange.c b/src/fideduperange.c
new file mode 100644
index 00000000..24813de8
--- /dev/null
+++ b/src/fideduperange.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Issue a raw FIDEDUPERANGE ioctl and report each destination's result.
+ */
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <linux/fs.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+#ifndef FIDEDUPERANGE
+/* These definitions must match the kernel UAPI. */
+#define FILE_DEDUPE_RANGE_SAME 0
+#define FILE_DEDUPE_RANGE_DIFFERS 1
+
+struct file_dedupe_range_info {
+ __s64 dest_fd;
+ __u64 dest_offset;
+ __u64 bytes_deduped;
+ __s32 status;
+ __u32 reserved;
+};
+
+struct file_dedupe_range {
+ __u64 src_offset;
+ __u64 src_length;
+ __u16 dest_count;
+ __u16 reserved1;
+ __u32 reserved2;
+ struct file_dedupe_range_info info[0];
+};
+
+#define FIDEDUPERANGE _IOWR(0x94, 54, struct file_dedupe_range)
+#endif
+
+static void
+usage(const char *progname)
+{
+ fprintf(stderr,
+ "Usage: %s src src_offset length dest dest_offset "
+ "[dest dest_offset ...]\n",
+ progname);
+ exit(EXIT_FAILURE);
+}
+
+static uint64_t
+parse_u64(const char *arg, const char *name)
+{
+ char *end;
+ unsigned long long value;
+
+ errno = 0;
+ value = strtoull(arg, &end, 0);
+ if (errno || end == arg || *end != '\0') {
+ fprintf(stderr, "Invalid %s: %s\n", name, arg);
+ exit(EXIT_FAILURE);
+ }
+
+ return value;
+}
+
+int
+main(int argc, char **argv)
+{
+ struct file_dedupe_range *range;
+ size_t range_size;
+ unsigned int dest_count;
+ unsigned int i;
+ int src_fd;
+ int ret;
+
+ if (argc < 6 || (argc - 4) % 2 != 0)
+ usage(argv[0]);
+
+ dest_count = (argc - 4) / 2;
+ if (dest_count > UINT16_MAX) {
+ fprintf(stderr, "Too many destinations: %u\n", dest_count);
+ return EXIT_FAILURE;
+ }
+
+ range_size = sizeof(*range) +
+ dest_count * sizeof(struct file_dedupe_range_info);
+ range = calloc(1, range_size);
+ if (!range) {
+ perror("calloc");
+ return EXIT_FAILURE;
+ }
+
+ src_fd = open(argv[1], O_RDONLY);
+ if (src_fd < 0) {
+ perror(argv[1]);
+ free(range);
+ return EXIT_FAILURE;
+ }
+
+ range->src_offset = parse_u64(argv[2], "source offset");
+ range->src_length = parse_u64(argv[3], "length");
+ range->dest_count = dest_count;
+
+ for (i = 0; i < dest_count; i++) {
+ const char *dest_path = argv[4 + i * 2];
+
+ range->info[i].dest_fd = open(dest_path, O_RDWR);
+ if (range->info[i].dest_fd < 0) {
+ perror(dest_path);
+ ret = EXIT_FAILURE;
+ goto close_destinations;
+ }
+ range->info[i].dest_offset =
+ parse_u64(argv[5 + i * 2], "destination offset");
+ }
+
+ if (ioctl(src_fd, FIDEDUPERANGE, range) < 0) {
+ perror("FIDEDUPERANGE");
+ ret = EXIT_FAILURE;
+ goto close_destinations;
+ }
+
+ for (i = 0; i < dest_count; i++)
+ printf("destination %u: bytes=%" PRIu64 " status=%d\n", i,
+ (uint64_t)range->info[i].bytes_deduped,
+ range->info[i].status);
+ ret = EXIT_SUCCESS;
+
+close_destinations:
+ while (i > 0) {
+ i--;
+ close(range->info[i].dest_fd);
+ }
+ close(src_fd);
+ free(range);
+ return ret;
+}
diff --git a/tests/generic/806 b/tests/generic/806
new file mode 100755
index 00000000..98254b79
--- /dev/null
+++ b/tests/generic/806
@@ -0,0 +1,83 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2026 Matthias Goergens. All Rights Reserved.
+#
+# FS QA Test No. 806
+#
+# Check FIDEDUPERANGE result reporting for zero-length requests and for a
+# multi-destination request where the VFS shortens only some destinations.
+#
+. ./common/preamble
+_begin_fstest auto quick dedupe clone
+
+. ./common/reflink
+
+_require_scratch_dedupe
+_require_test_program "fideduperange"
+
+_scratch_mkfs >>$seqres.full 2>&1
+_scratch_mount
+
+block_size=$(_get_block_size "$SCRATCH_MNT")
+short_length=$((2 * block_size))
+full_length=$((short_length + 100))
+
+src=$SCRATCH_MNT/src
+src_short=$SCRATCH_MNT/src-short
+dest_interior=$SCRATCH_MNT/dest-interior
+dest_eof=$SCRATCH_MNT/dest-eof
+dest_short_eof=$SCRATCH_MNT/dest-short-eof
+
+$XFS_IO_PROG -f -c "pwrite -S 0x6b 0 $full_length" "$src" \
+ >>$seqres.full 2>&1
+$XFS_IO_PROG -f -c "pwrite -S 0x6b 0 100" "$src_short" \
+ >>$seqres.full 2>&1
+$XFS_IO_PROG -f -c "pwrite -S 0x6b 0 $((full_length + block_size))" \
+ "$dest_interior" >>$seqres.full 2>&1
+$XFS_IO_PROG -f -c "pwrite -S 0x6b 0 $full_length" "$dest_eof" \
+ >>$seqres.full 2>&1
+$XFS_IO_PROG -f -c "pwrite -S 0x6b 0 100" "$dest_short_eof" \
+ >>$seqres.full 2>&1
+
+check_results()
+{
+ local description="$1"
+ local expected="$2"
+ shift 2
+ local result
+ local ret
+
+ result=$($here/src/fideduperange "$@" 2>&1)
+ ret=$?
+ {
+ echo "$description"
+ echo "$result"
+ } >>$seqres.full
+
+ if [ $ret -ne 0 ]; then
+ _fail "$description: ioctl helper failed"
+ fi
+ if [ "$result" != "$expected" ]; then
+ _fail "$description: unexpected ioctl result"
+ fi
+
+ echo "$description"
+}
+
+expected="destination 0: bytes=0 status=0"
+check_results "zero length: 0 bytes, SAME" "$expected" \
+ "$src" 0 0 "$dest_interior" 0
+
+expected="destination 0: bytes=$short_length status=0
+destination 1: bytes=$full_length status=0"
+check_results "mixed partial request: shortened, full" "$expected" \
+ "$src" 0 "$full_length" "$dest_interior" 0 "$dest_eof" 0
+
+expected="destination 0: bytes=0 status=-22
+destination 1: bytes=100 status=0"
+check_results "mixed sub-block request: EINVAL, full" "$expected" \
+ "$src_short" 0 100 "$dest_interior" 0 "$dest_short_eof" 0
+
+# success, all done
+status=0
+exit
diff --git a/tests/generic/806.out b/tests/generic/806.out
new file mode 100644
index 00000000..d7226e34
--- /dev/null
+++ b/tests/generic/806.out
@@ -0,0 +1,4 @@
+QA output created by 806
+zero length: 0 bytes, SAME
+mixed partial request: shortened, full
+mixed sub-block request: EINVAL, full
--
2.55.0
^ permalink raw reply related [flat|nested] 4+ messages in thread