Commit 8d2594d7 authored by Zhihao Cheng's avatar Zhihao Cheng
Browse files

ubi: fastmap: Use free pebs reserved for bad block handling 

mainline inclusion
from mainline-v6.7-rc1
commit 8ff4e620ac93a5d332735e4f5a4ff31d80682b9a
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9195H
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8ff4e620ac93a5d332735e4f5a4ff31d80682b9a

-------------------------------------------------

If new bad PEBs occur, UBI firstly consumes ubi->beb_rsvd_pebs, and then
ubi->avail_pebs, finally UBI becomes read-only if above two items are 0,
which means that the amount of PEBs for user volumes is not effected.
Besides, UBI reserves count of free PBEs is ubi->beb_rsvd_pebs while
filling wl pool or getting free PEBs, but ubi->avail_pebs is not reserved.
So ubi->beb_rsvd_pebs and ubi->avail_pebs have nothing to do with the
usage of free PEBs, UBI can use all free PEBs.

Commit 78d6d497 ("UBI: Move fastmap specific functions out of wl.c")
has removed beb_rsvd_pebs checking while filling pool. Now, don't reserve
ubi->beb_rsvd_pebs while filling wl_pool. This will fill more PEBs in pool
and also reduce fastmap updating frequency.

Also remove beb_rsvd_pebs checking in ubi_wl_get_fm_peb.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217787


Signed-off-by: default avatarZhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent 7fe802fa

drivers/mtd/ubi/fastmap-wl.c

+5 −11
Original line number Diff line number Diff line
@@ -76,7 +76,7 @@ struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor) 
{

	struct ubi_wl_entry *e = NULL;



	if (!ubi->free.rb_node || (ubi->free_count - ubi->beb_rsvd_pebs < 1))

	if (!ubi->free.rb_node)

		goto out;



	if (anchor)
@@ -100,28 +100,22 @@ struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor) 
/*

 * has_enough_free_count - whether ubi has enough free pebs to fill fm pools

 * @ubi: UBI device description object

 * @is_wl_pool: whether UBI is filling wear leveling pool

 *

 * This helper function checks whether there are enough free pebs (deducted

 * by fastmap pebs) to fill fm_pool and fm_wl_pool, above rule works after

 * there is at least one of free pebs is filled into fm_wl_pool.

 * For wear leveling pool, UBI should also reserve free pebs for bad pebs

 * handling, because there maybe no enough free pebs for user volumes after

 * producing new bad pebs.

 */

static bool has_enough_free_count(struct ubi_device *ubi, bool is_wl_pool)

static bool has_enough_free_count(struct ubi_device *ubi)

{

	int fm_used = 0;	// fastmap non anchor pebs.

	int beb_rsvd_pebs;



	if (!ubi->free.rb_node)

		return false;



	beb_rsvd_pebs = is_wl_pool ? ubi->beb_rsvd_pebs : 0;

	if (ubi->fm_wl_pool.size > 0 && !(ubi->ro_mode || ubi->fm_disabled))

		fm_used = ubi->fm_size / ubi->leb_size - 1;



	return ubi->free_count - beb_rsvd_pebs > fm_used;

	return ubi->free_count > fm_used;

}



/**
@@ -159,7 +153,7 @@ void ubi_refill_pools(struct ubi_device *ubi) 
	for (;;) {

		enough = 0;

		if (pool->size < pool->max_size) {

			if (!has_enough_free_count(ubi, false))

			if (!has_enough_free_count(ubi))

				break;



			e = wl_get_wle(ubi);
@@ -172,7 +166,7 @@ void ubi_refill_pools(struct ubi_device *ubi) 
			enough++;



		if (wl_pool->size < wl_pool->max_size) {

			if (!has_enough_free_count(ubi, true))

			if (!has_enough_free_count(ubi))

				break;



			e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);