Commit b77fc08e authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Vlastimil Babka
Browse files

mempool: add error injection support 



Add a call to should_fail_ex that forces mempool to actually allocate
from the pool to stress the mempool implementation when enabled through
debugfs.  By default should_fail{,_ex} prints a very verbose stack trace
that clutters the kernel log, slows down execution and triggers the
kernel bug detection in xfstests.  Pass FAULT_NOWARN and print a
single-line message notating the caller instead so that full tests
can be run with fault injection.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Link: https://patch.msgid.link/20251113084022.1255121-5-hch@lst.de


Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
parent 5c829783

mm/mempool.c

+18 −3
Original line number Diff line number Diff line
@@ -9,7 +9,7 @@ 
 *  started by Ingo Molnar, Copyright (C) 2001

 *  debugging by David Rientjes, Copyright (C) 2015

 */



#include <linux/fault-inject.h>

#include <linux/mm.h>

#include <linux/slab.h>

#include <linux/highmem.h>
@@ -20,6 +20,15 @@ 
#include <linux/writeback.h>

#include "slab.h"



static DECLARE_FAULT_ATTR(fail_mempool_alloc);



static int __init mempool_faul_inject_init(void)

{

	return PTR_ERR_OR_ZERO(fault_create_debugfs_attr("fail_mempool_alloc",

			NULL, &fail_mempool_alloc));

}

late_initcall(mempool_faul_inject_init);



#ifdef CONFIG_SLUB_DEBUG_ON

static void poison_error(mempool_t *pool, void *element, size_t size,

			 size_t byte)
@@ -404,9 +413,15 @@ void *mempool_alloc_noprof(mempool_t *pool, gfp_t gfp_mask) 
	gfp_temp = gfp_mask & ~(__GFP_DIRECT_RECLAIM|__GFP_IO);



repeat_alloc:



	if (should_fail_ex(&fail_mempool_alloc, 1, FAULT_NOWARN)) {

		pr_info("forcing mempool usage for %pS\n",

				(void *)_RET_IP_);

		element = NULL;

	} else {

		element = pool->alloc(gfp_temp, pool->pool_data);

	if (likely(element != NULL))

	}



	if (likely(element))

		return element;



	spin_lock_irqsave(&pool->lock, flags);