selftests/mount_setattr: increase tmpfs size for idmapped mount tests

The mount_setattr_idmapped fixture mounts a 2 MB tmpfs at /mnt and then
creates a 2 GB sparse ext4 image at /mnt/C/ext4.img. While ftruncate()
succeeds (sparse file), mkfs.ext4 needs to write actual metadata blocks
(inode tables, journal, bitmaps) which easily exceeds the 2 MB tmpfs
limit, causing ENOSPC and failing the fixture setup for all
mount_setattr_idmapped tests.

This was introduced by commit d37d4720c3e7 ("selftests/mount_settattr:
ensure that ext4 filesystem can be created") which increased the image
size from 2 MB to 2 GB but didn't adjust the tmpfs size.

Bump the tmpfs size to 256 MB which is sufficient for the ext4 metadata.

Fixes: d37d4720c3e7 ("selftests/mount_settattr: ensure that ext4 filesystem can be created")
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/tools/testing/selftests/mount_setattr/mount_setattr_test.c b/tools/testing/selftests/mount_setattr/mount_setattr_test.c
index 7aec3ae82a4466877c14c9a731e1a557a8dfcefb..c6dafb3cc11639d7c07c524d5c72723b164e713e 100644 (file)
--- a/tools/testing/selftests/mount_setattr/mount_setattr_test.c
+++ b/tools/testing/selftests/mount_setattr/mount_setattr_test.c
@@ -1020,7 +1020,7 @@ FIXTURE_SETUP(mount_setattr_idmapped)
                        "size=100000,mode=700"), 0);
 
        ASSERT_EQ(mount("testing", "/mnt", "tmpfs", MS_NOATIME | MS_NODEV,
-                       "size=2m,mode=700"), 0);
+                       "size=256m,mode=700"), 0);
 
        ASSERT_EQ(mkdir("/mnt/A", 0777), 0);