[PATCH v4 0/2] generic: new test to check nlink returned by fstat()

[PATCH v4 0/2] generic: new test to check nlink returned by fstat()

[ChenXiaoSong]

From: ChenXiaoSong <chenxiaosong@kylinos.cn>

v3->v4:
  - Patch#01: only add generic/002 to the "hardlink" group.
  - Patch#02: use `_fail` and `_exit`.

v3: https://lore.kernel.org/linux-cifs/20260724031210.332153-1-chenxiaosong@chenxiaosong.com/

ChenXiaoSong (2):
  generic/002: add test to hardlink group
  generic: new test to check nlink returned by fstat()

 tests/generic/002     |  2 +-
 tests/generic/798     | 59 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/798.out |  2 ++
 3 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100755 tests/generic/798
 create mode 100644 tests/generic/798.out

-- 
2.43.0

[PATCH v4 1/2] generic/002: add test to hardlink group

[ChenXiaoSong]

From: ChenXiaoSong <chenxiaosong@kylinos.cn>

The test creates and removes hard links, so add it to the hardlink
group.

Suggested-by: Zorro Lang <zlang@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
---
 tests/generic/002 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/generic/002 b/tests/generic/002
index 6df57a7a..a0773e22 100755
--- a/tests/generic/002
+++ b/tests/generic/002
@@ -7,7 +7,7 @@
 # simple inode link count test for a regular file
 #
 . ./common/preamble
-_begin_fstest metadata udf auto quick
+_begin_fstest metadata udf auto quick hardlink
 
 # Import common functions.
 . ./common/filter
-- 
2.43.0

[PATCH v4 2/2] generic: new test to check nlink returned by fstat()

[ChenXiaoSong]

From: ChenXiaoSong <chenxiaosong@kylinos.cn>

Add a test to verify that fstat(2) returns the expected
st_nlink value as hardlinks are created and removed.

Regression test for kernel commit:
9dd1964ac59d ("smb/client: fix incorrect nlink returned by fstat()")

Suggested-by: Zorro Lang <zlang@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
---
 tests/generic/798     | 59 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/798.out |  2 ++
 2 files changed, 61 insertions(+)
 create mode 100755 tests/generic/798
 create mode 100644 tests/generic/798.out

diff --git a/tests/generic/798 b/tests/generic/798
new file mode 100755
index 00000000..e48a69a1
--- /dev/null
+++ b/tests/generic/798
@@ -0,0 +1,59 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2026 KylinSoft Co., Ltd. All rights reserved.
+# Author(s): ChenXiaoSong <chenxiaosong@kylinos.cn>
+#
+# FS QA Test 798
+#
+# Check that fstat(2) returns the correct hard link count for a regular file.
+#
+#  from
+#  tests/generic/002
+#  Copyright (c) 2000-2001 Silicon Graphics, Inc.  All Rights Reserved.
+#
+. ./common/preamble
+_begin_fstest metadata auto quick hardlink
+
+_cleanup()
+{
+	cd /
+	rm -rf "$tmp".* "$testdir"
+}
+
+_require_test
+_require_hardlinks
+
+_fixed_by_fs_commit cifs 9dd1964ac59d \
+	"smb/client: fix incorrect nlink returned by fstat()"
+
+_get_nlink()
+{
+	# This calls `fstat()`, see `stat_f()` in xfsprogs-dev.git io/stat.c:
+	# https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git/tree/io/stat.c
+	$XFS_IO_PROG -c 'stat -r' "$1" |
+		sed -n 's/^stat\.nlink = //p'
+}
+
+testdir=$TEST_DIR/$seq
+rm -rf "$testdir"
+mkdir "$testdir"
+
+touch "$testdir/tmp.1"
+for ((l = 2; l <= 20; l++)); do
+	ln "$testdir/tmp.1" "$testdir/tmp.$l"
+	nlink=$(_get_nlink "$testdir/tmp.1")
+	if [ "$nlink" != "$l" ]; then
+		_fail "Expected nlink $l after creating link $testdir/tmp.$l, got ${nlink:-nothing}"
+	fi
+done
+
+for ((l = 20; l >= 1; l--)); do
+	nlink=$(_get_nlink "$testdir/tmp.1")
+	if [ "$nlink" != "$l" ]; then
+		_fail "Expected nlink $l before removing link $testdir/tmp.$l, got ${nlink:-nothing}"
+	fi
+	rm -f "$testdir/tmp.$l"
+done
+
+echo "Silence is golden"
+_exit 0
diff --git a/tests/generic/798.out b/tests/generic/798.out
new file mode 100644
index 00000000..216d6e93
--- /dev/null
+++ b/tests/generic/798.out
@@ -0,0 +1,2 @@
+QA output created by 798
+Silence is golden
-- 
2.43.0

Re: [PATCH v4 2/2] generic: new test to check nlink returned by fstat()

[Zorro Lang]

On Thu, Jul 30, 2026 at 02:12:38AM +0000, ChenXiaoSong wrote:
> From: ChenXiaoSong <chenxiaosong@kylinos.cn>
> 
> Add a test to verify that fstat(2) returns the expected
> st_nlink value as hardlinks are created and removed.
> 
> Regression test for kernel commit:
> 9dd1964ac59d ("smb/client: fix incorrect nlink returned by fstat()")
> 
> Suggested-by: Zorro Lang <zlang@kernel.org>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
> ---

This version is good to me now,

Reviewed-by: Zorro Lang <zlang@kernel.org>

(Please To/CC fstests@vger.kernel.org)

>  tests/generic/798     | 59 +++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/798.out |  2 ++
>  2 files changed, 61 insertions(+)
>  create mode 100755 tests/generic/798
>  create mode 100644 tests/generic/798.out
> 
> diff --git a/tests/generic/798 b/tests/generic/798
> new file mode 100755
> index 00000000..e48a69a1
> --- /dev/null
> +++ b/tests/generic/798
> @@ -0,0 +1,59 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2026 KylinSoft Co., Ltd. All rights reserved.
> +# Author(s): ChenXiaoSong <chenxiaosong@kylinos.cn>
> +#
> +# FS QA Test 798
> +#
> +# Check that fstat(2) returns the correct hard link count for a regular file.
> +#
> +#  from
> +#  tests/generic/002
> +#  Copyright (c) 2000-2001 Silicon Graphics, Inc.  All Rights Reserved.
> +#
> +. ./common/preamble
> +_begin_fstest metadata auto quick hardlink
> +
> +_cleanup()
> +{
> +	cd /
> +	rm -rf "$tmp".* "$testdir"
> +}
> +
> +_require_test
> +_require_hardlinks
> +
> +_fixed_by_fs_commit cifs 9dd1964ac59d \
> +	"smb/client: fix incorrect nlink returned by fstat()"
> +
> +_get_nlink()
> +{
> +	# This calls `fstat()`, see `stat_f()` in xfsprogs-dev.git io/stat.c:
> +	# https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git/tree/io/stat.c
> +	$XFS_IO_PROG -c 'stat -r' "$1" |
> +		sed -n 's/^stat\.nlink = //p'
> +}
> +
> +testdir=$TEST_DIR/$seq
> +rm -rf "$testdir"
> +mkdir "$testdir"
> +
> +touch "$testdir/tmp.1"
> +for ((l = 2; l <= 20; l++)); do
> +	ln "$testdir/tmp.1" "$testdir/tmp.$l"
> +	nlink=$(_get_nlink "$testdir/tmp.1")
> +	if [ "$nlink" != "$l" ]; then
> +		_fail "Expected nlink $l after creating link $testdir/tmp.$l, got ${nlink:-nothing}"
> +	fi
> +done
> +
> +for ((l = 20; l >= 1; l--)); do
> +	nlink=$(_get_nlink "$testdir/tmp.1")
> +	if [ "$nlink" != "$l" ]; then
> +		_fail "Expected nlink $l before removing link $testdir/tmp.$l, got ${nlink:-nothing}"
> +	fi
> +	rm -f "$testdir/tmp.$l"
> +done
> +
> +echo "Silence is golden"
> +_exit 0
> diff --git a/tests/generic/798.out b/tests/generic/798.out
> new file mode 100644
> index 00000000..216d6e93
> --- /dev/null
> +++ b/tests/generic/798.out
> @@ -0,0 +1,2 @@
> +QA output created by 798
> +Silence is golden
> -- 
> 2.43.0
> 

Re: [PATCH v4 1/2] generic/002: add test to hardlink group

[Zorro Lang]

On Thu, Jul 30, 2026 at 02:12:37AM +0000, ChenXiaoSong wrote:
> From: ChenXiaoSong <chenxiaosong@kylinos.cn>
> 
> The test creates and removes hard links, so add it to the hardlink
> group.
> 
> Suggested-by: Zorro Lang <zlang@kernel.org>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
> ---

So you‘ve given up on re-writing this old case :)
Anyway, this's good to me.

Reviewed-by: Zorro Lang <zlang@kernel.org>

(Please CC fstests list)

>  tests/generic/002 | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tests/generic/002 b/tests/generic/002
> index 6df57a7a..a0773e22 100755
> --- a/tests/generic/002
> +++ b/tests/generic/002
> @@ -7,7 +7,7 @@
>  # simple inode link count test for a regular file
>  #
>  . ./common/preamble
> -_begin_fstest metadata udf auto quick
> +_begin_fstest metadata udf auto quick hardlink
>  
>  # Import common functions.
>  . ./common/filter
> -- 
> 2.43.0
>