[LTP] [PATCH] refluxfs: Check kernel reflink support before mount

[LTP] [PATCH] refluxfs: Check kernel reflink support before mount

[Martin Doucha]

On some systems, mkfs.xfs can format XFS partition with reflink support
but the kernel then cannot mount it. Check for kernel reflink support
in setup() before mount.

Signed-off-by: Martin Doucha <mdoucha@suse.cz>
---
 testcases/cve/refluxfs.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/testcases/cve/refluxfs.c b/testcases/cve/refluxfs.c
index e41f35c53..277d56bb7 100644
--- a/testcases/cve/refluxfs.c
+++ b/testcases/cve/refluxfs.c
@@ -38,6 +38,7 @@
  */
 
 #include <pwd.h>
+#include <sys/mount.h>
 
 #include "tst_test.h"
 #include "tst_safe_prw.h"
@@ -94,6 +95,15 @@ static void setup(void)
 	int probe_fd, probe_dio_fd;
 	struct stat sb;
 
+	SAFE_MKDIR(MNTPOINT, 0755);
+	TEST(mount(tst_device->dev, MNTPOINT, tst_device->fs_type, 0, NULL));
+
+	if (TST_RET == -1 && TST_ERR == EOPNOTSUPP)
+		tst_brk(TCONF, "Kernel does not support XFS reflinks");
+
+	if (TST_RET)
+		tst_brk(TBROK | TTERRNO, "Mount failed");
+
 	SAFE_STAT(MNTPOINT, &sb);
 	blksize = sb.st_blksize;
 
@@ -197,6 +207,11 @@ static void cleanup(void)
 	free(tbuf);
 	free(wbuf);
 	free(rbuf);
+
+	SAFE_SETEUID(0);
+
+	if (tst_is_mounted(MNTPOINT))
+		SAFE_UMOUNT(MNTPOINT);
 }
 
 static struct tst_test test = {
@@ -205,8 +220,7 @@ static struct tst_test test = {
 	.cleanup = cleanup,
 	.runtime = 180,
 	.needs_root = 1,
-	.mount_device = 1,
-	.mntpoint = MNTPOINT,
+	.format_device = 1,
 	.filesystems = (struct tst_fs []) {
 		{
 			.type = "xfs",
-- 
2.54.0


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Re: [LTP] [PATCH] refluxfs: Check kernel reflink support before mount

[Cyril Hrubis]

Hi!
> +	if (TST_RET == -1 && TST_ERR == EOPNOTSUPP)
> +		tst_brk(TCONF, "Kernel does not support XFS reflinks");

Wouldn't it make more sense to add the check for EOPNOTSUPP into the
tst_test.c library?

-- 
Cyril Hrubis
chrubis@suse.cz

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Re: [LTP] refluxfs: Check kernel reflink support before mount

[linuxtestproject.agent]

Hi Martin,

On Aug 12, 2026, Martin Doucha wrote:
> refluxfs: Check kernel reflink support before mount

Verdict - Reviewed

---
Note:

The agent can sometimes produce false positives although often its
findings are genuine. If you find issues with the review, please
comment this email or ignore the suggestions.

Regards,
LTP AI Reviewer

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