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ubi: fastmap: Check wl_pool for free peb before wear leveling

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UBI fetches free peb from wl_pool during wear leveling, so UBI should
check wl_pool's empty status before wear leveling. Otherwise, UBI will
miss wear leveling chances when free pebs are run out.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
Zhihao Cheng 2022-05-10 20:31:25 +08:00 committed by Richard Weinberger
parent d09e9a2bdd
commit 14072ee33d
3 changed files with 66 additions and 2 deletions
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52
drivers/mtd/ubi/fastmap-wl.c
View file

@ -275,6 +275,58 @@ out:
return ret;
}
/**
* next_peb_for_wl - returns next PEB to be used internally by the
* WL sub-system.
*
* @ubi: UBI device description object
*/
static struct ubi_wl_entry *next_peb_for_wl(struct ubi_device *ubi)
{
struct ubi_fm_pool *pool = &ubi->fm_wl_pool;
int pnum;
if (pool->used == pool->size)
return NULL;
pnum = pool->pebs[pool->used];
return ubi->lookuptbl[pnum];
}
/**
* need_wear_leveling - checks whether to trigger a wear leveling work.
* UBI fetches free PEB from wl_pool, we check free PEBs from both 'wl_pool'
* and 'ubi->free', because free PEB in 'ubi->free' tree maybe moved into
* 'wl_pool' by ubi_refill_pools().
*
* @ubi: UBI device description object
*/
static bool need_wear_leveling(struct ubi_device *ubi)
{
int ec;
struct ubi_wl_entry *e;
if (!ubi->used.rb_node)
return false;
e = next_peb_for_wl(ubi);
if (!e) {
if (!ubi->free.rb_node)
return false;
e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
ec = e->ec;
} else {
ec = e->ec;
if (ubi->free.rb_node) {
e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
ec = max(ec, e->ec);
}
}
e = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, u.rb);
return ec - e->ec >= UBI_WL_THRESHOLD;
}
/* get_peb_for_wl - returns a PEB to be used internally by the WL sub-system.
*
* @ubi: UBI device description object

14
drivers/mtd/ubi/wl.c
View file

@ -670,7 +670,11 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
ubi_assert(!ubi->move_from && !ubi->move_to);
ubi_assert(!ubi->move_to_put);
#ifdef CONFIG_MTD_UBI_FASTMAP
if (!next_peb_for_wl(ubi) ||
#else
if (!ubi->free.rb_node ||
#endif
(!ubi->used.rb_node && !ubi->scrub.rb_node)) {
/*
* No free physical eraseblocks? Well, they must be waiting in
@ -1003,8 +1007,6 @@ out_cancel:
static int ensure_wear_leveling(struct ubi_device *ubi, int nested)
{
int err = 0;
struct ubi_wl_entry *e1;
struct ubi_wl_entry *e2;
struct ubi_work *wrk;
spin_lock(&ubi->wl_lock);
@ -1017,6 +1019,13 @@ static int ensure_wear_leveling(struct ubi_device *ubi, int nested)
* the WL worker has to be scheduled anyway.
*/
if (!ubi->scrub.rb_node) {
#ifdef CONFIG_MTD_UBI_FASTMAP
if (!need_wear_leveling(ubi))
goto out_unlock;
#else
struct ubi_wl_entry *e1;
struct ubi_wl_entry *e2;
if (!ubi->used.rb_node || !ubi->free.rb_node)
/* No physical eraseblocks - no deal */
goto out_unlock;
@ -1032,6 +1041,7 @@ static int ensure_wear_leveling(struct ubi_device *ubi, int nested)
if (!(e2->ec - e1->ec >= UBI_WL_THRESHOLD))
goto out_unlock;
#endif
dbg_wl("schedule wear-leveling");
} else
dbg_wl("schedule scrubbing");

2
drivers/mtd/ubi/wl.h
View file

@ -5,6 +5,8 @@
static void update_fastmap_work_fn(struct work_struct *wrk);
static struct ubi_wl_entry *find_anchor_wl_entry(struct rb_root *root);
static struct ubi_wl_entry *get_peb_for_wl(struct ubi_device *ubi);
static struct ubi_wl_entry *next_peb_for_wl(struct ubi_device *ubi);
static bool need_wear_leveling(struct ubi_device *ubi);
static void ubi_fastmap_close(struct ubi_device *ubi);
static inline void ubi_fastmap_init(struct ubi_device *ubi, int *count)
{