Revision 9dfb3b8d655022760ca68af11821f1c63aa547c3 authored by Matthew Wilcox (Oracle) on 30 July 2022, 04:25:18 UTC, committed by Andrew Morton on 28 August 2022, 21:02:43 UTC
If we allocate a new page, we need to make sure that our folio matches
that new page.

If we do end up in this code path, we store the wrong page in the shmem
inode's page cache, and I would rather imagine that data corruption
ensues.

This will be solved by changing shmem_replace_page() to
shmem_replace_folio(), but this is the minimal fix.

Link: https://lkml.kernel.org/r/20220730042518.1264767-1-willy@infradead.org
Fixes: da08e9b79323 ("mm/shmem: convert shmem_swapin_page() to shmem_swapin_folio()")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
1 parent ab74ef7
Raw File
percpu_freelist.h
/* SPDX-License-Identifier: GPL-2.0-only */
/* Copyright (c) 2016 Facebook
 */
#ifndef __PERCPU_FREELIST_H__
#define __PERCPU_FREELIST_H__
#include <linux/spinlock.h>
#include <linux/percpu.h>

struct pcpu_freelist_head {
	struct pcpu_freelist_node *first;
	raw_spinlock_t lock;
};

struct pcpu_freelist {
	struct pcpu_freelist_head __percpu *freelist;
	struct pcpu_freelist_head extralist;
};

struct pcpu_freelist_node {
	struct pcpu_freelist_node *next;
};

/* pcpu_freelist_* do spin_lock_irqsave. */
void pcpu_freelist_push(struct pcpu_freelist *, struct pcpu_freelist_node *);
struct pcpu_freelist_node *pcpu_freelist_pop(struct pcpu_freelist *);
/* __pcpu_freelist_* do spin_lock only. caller must disable irqs. */
void __pcpu_freelist_push(struct pcpu_freelist *, struct pcpu_freelist_node *);
struct pcpu_freelist_node *__pcpu_freelist_pop(struct pcpu_freelist *);
void pcpu_freelist_populate(struct pcpu_freelist *s, void *buf, u32 elem_size,
			    u32 nr_elems);
int pcpu_freelist_init(struct pcpu_freelist *);
void pcpu_freelist_destroy(struct pcpu_freelist *s);
#endif
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