The patch titled
Subject: lib/test_xarray.c: fix error assumptions on check_xa_multi_store_adv_add()
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
lib-test_xarrayc-fix-error-assumptions-on-check_xa_multi_store_adv_add.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/lib-test_xarrayc-fix-error-assumptions-on-check_xa_multi_store_adv_add.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Subject: lib/test_xarray.c: fix error assumptions on check_xa_multi_store_adv_add()
Date: Tue, 23 Apr 2024 12:22:21 -0700
While testing lib/test_xarray in userspace I've noticed we can fail with:
make -C tools/testing/radix-tree
/tools/testing/radix-tree/xarray
BUG at check_xa_multi_store_adv_add:749
xarray: 0x55905fb21a00x head 0x55905fa1d8e0x flags 0 marks 0 0 0
0: 0x55905fa1d8e0x
xarray: ../../../lib/test_xarray.c:749: check_xa_multi_store_adv_add: Assertion `0' failed.
Aborted
We get a failure with a BUG_ON(), and that is because we actually can
fail due to -ENOMEM, the check in xas_nomem() will fix this for us so
it makes no sense to expect no failure inside the loop. So modify the
check and since this is also useful for instructional purposes clarify
the situation.
The check for XA_BUG_ON(xa, xa_load(xa, index) != p) is already done
at the end of the loop so just remove the bogus on inside the loop.
With this we now pass the test in both kernel and userspace:
In userspace:
/tools/testing/radix-tree/xarray
XArray: 149092856 of 149092856 tests passed
In kernel space:
XArray: 148257077 of 148257077 tests passed
Link: https://lkml.kernel.org/r/20240423192221.301095-3-mcgrof@xxxxxxxxxx
Fixes: a60cc288a1a2 ("test_xarray: add tests for advanced multi-index use")
Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Daniel Gomez <da.gomez@xxxxxxxxxxx>
Cc: Darrick J. Wong <djwong@xxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/test_xarray.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
--- a/lib/test_xarray.c~lib-test_xarrayc-fix-error-assumptions-on-check_xa_multi_store_adv_add
+++ a/lib/test_xarray.c
@@ -744,15 +744,20 @@ static noinline void check_xa_multi_stor
do {
xas_lock_irq(&xas);
-
xas_store(&xas, p);
- XA_BUG_ON(xa, xas_error(&xas));
- XA_BUG_ON(xa, xa_load(xa, index) != p);
-
xas_unlock_irq(&xas);
+ /*
+ * In our selftest case the only failure we can expect is for
+ * there not to be enough memory as we're not mimicking the
+ * entire page cache, so verify that's the only error we can run
+ * into here. The xas_nomem() which follows will ensure to fix
+ * that condition for us so to chug on on the loop.
+ */
+ XA_BUG_ON(xa, xas_error(&xas) && xas_error(&xas) != -ENOMEM);
} while (xas_nomem(&xas, GFP_KERNEL));
XA_BUG_ON(xa, xas_error(&xas));
+ XA_BUG_ON(xa, xa_load(xa, index) != p);
}
/* mimics page_cache_delete() */
_
Patches currently in -mm which might be from mcgrof@xxxxxxxxxx are
tools-fix-userspace-compilation-with-new-test_xarray-changes.patch
lib-test_xarrayc-fix-error-assumptions-on-check_xa_multi_store_adv_add.patch
