kevin/linux
1
Fork 0
Code

XArray: add cmpxchg order test

Browse Source 
XArray multi-index entries do not keep track of the order stored once the
entry is being marked as used with cmpxchg (conditionally replaced with
NULL).  Add a test to check the order is actually lost.  The test also
verifies the order and entries for all the tied indexes before and after
the NULL replacement with xa_cmpxchg.

Add another entry at 1 << order that keeps the node around and the order
information for the NULL-entry after xa_cmpxchg.

Link: https://lkml.kernel.org/r/20240131225125.1370598-3-mcgrof@kernel.org
Signed-off-by: Daniel Gomez <da.gomez@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Daniel Gomez 2024-01-31 14:51:25 -08:00 committed by Andrew Morton
parent a60cc288a1
commit e777ae44e3
1 changed files with 54 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
lib/test_xarray.c
View File

@ -423,6 +423,59 @@ static noinline void check_cmpxchg(struct xarray *xa)
XA_BUG_ON(xa, !xa_empty(xa));
}
static noinline void check_cmpxchg_order(struct xarray *xa)
{
#ifdef CONFIG_XARRAY_MULTI
void *FIVE = xa_mk_value(5);
unsigned int i, order = 3;
XA_BUG_ON(xa, xa_store_order(xa, 0, order, FIVE, GFP_KERNEL));
/* Check entry FIVE has the order saved */
XA_BUG_ON(xa, xa_get_order(xa, xa_to_value(FIVE)) != order);
/* Check all the tied indexes have the same entry and order */
for (i = 0; i < (1 << order); i++) {
XA_BUG_ON(xa, xa_load(xa, i) != FIVE);
XA_BUG_ON(xa, xa_get_order(xa, i) != order);
}
/* Ensure that nothing is stored at index '1 << order' */
XA_BUG_ON(xa, xa_load(xa, 1 << order) != NULL);
/*
* Additionally, keep the node information and the order at
* '1 << order'
*/
XA_BUG_ON(xa, xa_store_order(xa, 1 << order, order, FIVE, GFP_KERNEL));
for (i = (1 << order); i < (1 << order) + (1 << order) - 1; i++) {
XA_BUG_ON(xa, xa_load(xa, i) != FIVE);
XA_BUG_ON(xa, xa_get_order(xa, i) != order);
}
/* Conditionally replace FIVE entry at index '0' with NULL */
XA_BUG_ON(xa, xa_cmpxchg(xa, 0, FIVE, NULL, GFP_KERNEL) != FIVE);
/* Verify the order is lost at FIVE (and old) entries */
XA_BUG_ON(xa, xa_get_order(xa, xa_to_value(FIVE)) != 0);
/* Verify the order and entries are lost in all the tied indexes */
for (i = 0; i < (1 << order); i++) {
XA_BUG_ON(xa, xa_load(xa, i) != NULL);
XA_BUG_ON(xa, xa_get_order(xa, i) != 0);
}
/* Verify node and order are kept at '1 << order' */
for (i = (1 << order); i < (1 << order) + (1 << order) - 1; i++) {
XA_BUG_ON(xa, xa_load(xa, i) != FIVE);
XA_BUG_ON(xa, xa_get_order(xa, i) != order);
}
xa_store_order(xa, 0, BITS_PER_LONG - 1, NULL, GFP_KERNEL);
XA_BUG_ON(xa, !xa_empty(xa));
#endif
}
static noinline void check_reserve(struct xarray *xa)
{
void *entry;
@ -1976,6 +2029,7 @@ static int xarray_checks(void)
check_xas_erase(&array);
check_insert(&array);
check_cmpxchg(&array);
check_cmpxchg_order(&array);
check_reserve(&array);
check_reserve(&xa0);
check_multi_store(&array);