The quilt patch titled
Subject: frontswap: invoke ops->init for online swap device in frontswap_register_ops
has been removed from the -mm tree. Its filename was
frontswap-invoke-ops-init-for-online-swap-device-in-frontswap_register_ops.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
From: Liu Shixin <liushixin2@xxxxxxxxxx>
Subject: frontswap: invoke ops->init for online swap device in frontswap_register_ops
Date: Sat, 27 Aug 2022 18:45:57 +0800
Since we are supported to delay zswap initializaton, we need to invoke
ops->init for the swap device which is already online when register
backend.
This patch is a revert of f328c1d16e4c ("frontswap: simplify
frontswap_register_ops") and 633423a09cb5 ("mm: mark swap_lock and
swap_active_head static").
Link: https://lkml.kernel.org/r/20220827104600.1813214-3-liushixin2@xxxxxxxxxx
Signed-off-by: Liu Shixin <liushixin2@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Dan Streetman <ddstreet@xxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Seth Jennings <sjenning@xxxxxxxxxx>
Cc: Vitaly Wool <vitaly.wool@xxxxxxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/swapfile.h | 2 +
mm/frontswap.c | 47 +++++++++++++++++++++++++++++++++++++
mm/swapfile.c | 4 +--
3 files changed, 51 insertions(+), 2 deletions(-)
--- a/include/linux/swapfile.h~frontswap-invoke-ops-init-for-online-swap-device-in-frontswap_register_ops
+++ a/include/linux/swapfile.h
@@ -6,6 +6,8 @@
* these were static in swapfile.c but frontswap.c needs them and we don't
* want to expose them to the dozens of source files that include swap.h
*/
+extern spinlock_t swap_lock;
+extern struct plist_head swap_active_head;
extern struct swap_info_struct *swap_info[];
extern unsigned long generic_max_swapfile_size(void);
/* Maximum swapfile size supported for the arch (not inclusive). */
--- a/mm/frontswap.c~frontswap-invoke-ops-init-for-online-swap-device-in-frontswap_register_ops
+++ a/mm/frontswap.c
@@ -96,11 +96,58 @@ static inline void inc_frontswap_invalid
*/
int frontswap_register_ops(const struct frontswap_ops *ops)
{
+ DECLARE_BITMAP(a, MAX_SWAPFILES);
+ DECLARE_BITMAP(b, MAX_SWAPFILES);
+ struct swap_info_struct *si;
+ unsigned int i;
+
if (frontswap_ops)
return -EINVAL;
+ bitmap_zero(a, MAX_SWAPFILES);
+ bitmap_zero(b, MAX_SWAPFILES);
+
+ spin_lock(&swap_lock);
+ plist_for_each_entry(si, &swap_active_head, list) {
+ if (!WARN_ON(!si->frontswap_map))
+ __set_bit(si->type, a);
+ }
+ spin_unlock(&swap_lock);
+
+ /* the new ops needs to know the currently active swap devices */
+ for_each_set_bit(i, a, MAX_SWAPFILES) {
+ pr_err("init frontswap_ops\n");
+ ops->init(i);
+ }
+
frontswap_ops = ops;
static_branch_inc(&frontswap_enabled_key);
+
+ spin_lock(&swap_lock);
+ plist_for_each_entry(si, &swap_active_head, list) {
+ if (si->frontswap_map)
+ __set_bit(si->type, b);
+ }
+ spin_unlock(&swap_lock);
+
+ /*
+ * On the very unlikely chance that a swap device was added or
+ * removed between setting the "a" list bits and the ops init
+ * calls, we re-check and do init or invalidate for any changed
+ * bits.
+ */
+ if (unlikely(!bitmap_equal(a, b, MAX_SWAPFILES))) {
+ for (i = 0; i < MAX_SWAPFILES; i++) {
+ if (!test_bit(i, a) && test_bit(i, b)) {
+ pr_err("init frontswap_ops re\n");
+ ops->init(i);
+ } else if (test_bit(i, a) && !test_bit(i, b)) {
+ pr_err("inval frontswap_ops re\n");
+ ops->invalidate_area(i);
+ }
+ }
+ }
+
return 0;
}
--- a/mm/swapfile.c~frontswap-invoke-ops-init-for-online-swap-device-in-frontswap_register_ops
+++ a/mm/swapfile.c
@@ -51,7 +51,7 @@ static bool swap_count_continued(struct
unsigned char);
static void free_swap_count_continuations(struct swap_info_struct *);
-static DEFINE_SPINLOCK(swap_lock);
+DEFINE_SPINLOCK(swap_lock);
static unsigned int nr_swapfiles;
atomic_long_t nr_swap_pages;
/*
@@ -77,7 +77,7 @@ static const char Unused_offset[] = "Unu
* all active swap_info_structs
* protected with swap_lock, and ordered by priority.
*/
-static PLIST_HEAD(swap_active_head);
+PLIST_HEAD(swap_active_head);
/*
* all available (active, not full) swap_info_structs
_
Patches currently in -mm which might be from liushixin2@xxxxxxxxxx are
mm-zswap-replace-zswap_init_started-failed-with-zswap_init_state.patch
mm-zswap-delay-the-initializaton-of-zswap-until-the-first-enablement.patch
mm-zswap-skip-confusing-print-info.patch
