u-boot/drivers/mtd/ubi/fastmap-wl.c
Martin Townsend 2d2d306f79 ubi: Ensure no fastmap flush after uif_close
On detach UBI attempts to update fastmap after closing user interfaces
but at this point UBI volumes have already been free()'ed and fastmap
can no longer access these data structures.

Signed-off-by: Martin Townsend <mtownsend1973@gmail.com>
Cc: hs@denx.de
Cc: kmpark@infradead.org
Cc: richard@sigma-star.at
2018-02-06 07:05:57 +01:00

367 lines
8.3 KiB
C

/*
* Copyright (c) 2012 Linutronix GmbH
* Copyright (c) 2014 sigma star gmbh
* Author: Richard Weinberger <richard@nod.at>
*
* SPDX-License-Identifier: GPL-2.0+
*
*/
/**
* update_fastmap_work_fn - calls ubi_update_fastmap from a work queue
* @wrk: the work description object
*/
#ifndef __UBOOT__
static void update_fastmap_work_fn(struct work_struct *wrk)
#else
void update_fastmap_work_fn(struct ubi_device *ubi)
#endif
{
#ifndef __UBOOT__
struct ubi_device *ubi = container_of(wrk, struct ubi_device, fm_work);
#endif
ubi_update_fastmap(ubi);
spin_lock(&ubi->wl_lock);
ubi->fm_work_scheduled = 0;
spin_unlock(&ubi->wl_lock);
}
/**
* find_anchor_wl_entry - find wear-leveling entry to used as anchor PEB.
* @root: the RB-tree where to look for
*/
static struct ubi_wl_entry *find_anchor_wl_entry(struct rb_root *root)
{
struct rb_node *p;
struct ubi_wl_entry *e, *victim = NULL;
int max_ec = UBI_MAX_ERASECOUNTER;
ubi_rb_for_each_entry(p, e, root, u.rb) {
if (e->pnum < UBI_FM_MAX_START && e->ec < max_ec) {
victim = e;
max_ec = e->ec;
}
}
return victim;
}
/**
* return_unused_pool_pebs - returns unused PEB to the free tree.
* @ubi: UBI device description object
* @pool: fastmap pool description object
*/
static void return_unused_pool_pebs(struct ubi_device *ubi,
struct ubi_fm_pool *pool)
{
int i;
struct ubi_wl_entry *e;
for (i = pool->used; i < pool->size; i++) {
e = ubi->lookuptbl[pool->pebs[i]];
wl_tree_add(e, &ubi->free);
ubi->free_count++;
}
}
static int anchor_pebs_avalible(struct rb_root *root)
{
struct rb_node *p;
struct ubi_wl_entry *e;
ubi_rb_for_each_entry(p, e, root, u.rb)
if (e->pnum < UBI_FM_MAX_START)
return 1;
return 0;
}
/**
* ubi_wl_get_fm_peb - find a physical erase block with a given maximal number.
* @ubi: UBI device description object
* @anchor: This PEB will be used as anchor PEB by fastmap
*
* The function returns a physical erase block with a given maximal number
* and removes it from the wl subsystem.
* Must be called with wl_lock held!
*/
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))
goto out;
if (anchor)
e = find_anchor_wl_entry(&ubi->free);
else
e = find_mean_wl_entry(ubi, &ubi->free);
if (!e)
goto out;
self_check_in_wl_tree(ubi, e, &ubi->free);
/* remove it from the free list,
* the wl subsystem does no longer know this erase block */
rb_erase(&e->u.rb, &ubi->free);
ubi->free_count--;
out:
return e;
}
/**
* ubi_refill_pools - refills all fastmap PEB pools.
* @ubi: UBI device description object
*/
void ubi_refill_pools(struct ubi_device *ubi)
{
struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool;
struct ubi_fm_pool *pool = &ubi->fm_pool;
struct ubi_wl_entry *e;
int enough;
spin_lock(&ubi->wl_lock);
return_unused_pool_pebs(ubi, wl_pool);
return_unused_pool_pebs(ubi, pool);
wl_pool->size = 0;
pool->size = 0;
for (;;) {
enough = 0;
if (pool->size < pool->max_size) {
if (!ubi->free.rb_node)
break;
e = wl_get_wle(ubi);
if (!e)
break;
pool->pebs[pool->size] = e->pnum;
pool->size++;
} else
enough++;
if (wl_pool->size < wl_pool->max_size) {
if (!ubi->free.rb_node ||
(ubi->free_count - ubi->beb_rsvd_pebs < 5))
break;
e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
self_check_in_wl_tree(ubi, e, &ubi->free);
rb_erase(&e->u.rb, &ubi->free);
ubi->free_count--;
wl_pool->pebs[wl_pool->size] = e->pnum;
wl_pool->size++;
} else
enough++;
if (enough == 2)
break;
}
wl_pool->used = 0;
pool->used = 0;
spin_unlock(&ubi->wl_lock);
}
/**
* ubi_wl_get_peb - get a physical eraseblock.
* @ubi: UBI device description object
*
* This function returns a physical eraseblock in case of success and a
* negative error code in case of failure.
* Returns with ubi->fm_eba_sem held in read mode!
*/
int ubi_wl_get_peb(struct ubi_device *ubi)
{
int ret, retried = 0;
struct ubi_fm_pool *pool = &ubi->fm_pool;
struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool;
again:
down_read(&ubi->fm_eba_sem);
spin_lock(&ubi->wl_lock);
/* We check here also for the WL pool because at this point we can
* refill the WL pool synchronous. */
if (pool->used == pool->size || wl_pool->used == wl_pool->size) {
spin_unlock(&ubi->wl_lock);
up_read(&ubi->fm_eba_sem);
ret = ubi_update_fastmap(ubi);
if (ret) {
ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
down_read(&ubi->fm_eba_sem);
return -ENOSPC;
}
down_read(&ubi->fm_eba_sem);
spin_lock(&ubi->wl_lock);
}
if (pool->used == pool->size) {
spin_unlock(&ubi->wl_lock);
if (retried) {
ubi_err(ubi, "Unable to get a free PEB from user WL pool");
ret = -ENOSPC;
goto out;
}
retried = 1;
up_read(&ubi->fm_eba_sem);
goto again;
}
ubi_assert(pool->used < pool->size);
ret = pool->pebs[pool->used++];
prot_queue_add(ubi, ubi->lookuptbl[ret]);
spin_unlock(&ubi->wl_lock);
out:
return ret;
}
/* get_peb_for_wl - returns a PEB to be used internally by the WL sub-system.
*
* @ubi: UBI device description object
*/
static struct ubi_wl_entry *get_peb_for_wl(struct ubi_device *ubi)
{
struct ubi_fm_pool *pool = &ubi->fm_wl_pool;
int pnum;
if (pool->used == pool->size) {
#ifndef __UBOOT__
/* We cannot update the fastmap here because this
* function is called in atomic context.
* Let's fail here and refill/update it as soon as possible. */
if (!ubi->fm_work_scheduled) {
ubi->fm_work_scheduled = 1;
schedule_work(&ubi->fm_work);
}
return NULL;
#else
/*
* No work queues in U-Boot, we must do this immediately
*/
update_fastmap_work_fn(ubi);
#endif
}
pnum = pool->pebs[pool->used++];
return ubi->lookuptbl[pnum];
}
/**
* ubi_ensure_anchor_pebs - schedule wear-leveling to produce an anchor PEB.
* @ubi: UBI device description object
*/
int ubi_ensure_anchor_pebs(struct ubi_device *ubi)
{
struct ubi_work *wrk;
spin_lock(&ubi->wl_lock);
if (ubi->wl_scheduled) {
spin_unlock(&ubi->wl_lock);
return 0;
}
ubi->wl_scheduled = 1;
spin_unlock(&ubi->wl_lock);
wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS);
if (!wrk) {
spin_lock(&ubi->wl_lock);
ubi->wl_scheduled = 0;
spin_unlock(&ubi->wl_lock);
return -ENOMEM;
}
wrk->anchor = 1;
wrk->func = &wear_leveling_worker;
schedule_ubi_work(ubi, wrk);
return 0;
}
/**
* ubi_wl_put_fm_peb - returns a PEB used in a fastmap to the wear-leveling
* sub-system.
* see: ubi_wl_put_peb()
*
* @ubi: UBI device description object
* @fm_e: physical eraseblock to return
* @lnum: the last used logical eraseblock number for the PEB
* @torture: if this physical eraseblock has to be tortured
*/
int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *fm_e,
int lnum, int torture)
{
struct ubi_wl_entry *e;
int vol_id, pnum = fm_e->pnum;
dbg_wl("PEB %d", pnum);
ubi_assert(pnum >= 0);
ubi_assert(pnum < ubi->peb_count);
spin_lock(&ubi->wl_lock);
e = ubi->lookuptbl[pnum];
/* This can happen if we recovered from a fastmap the very
* first time and writing now a new one. In this case the wl system
* has never seen any PEB used by the original fastmap.
*/
if (!e) {
e = fm_e;
ubi_assert(e->ec >= 0);
ubi->lookuptbl[pnum] = e;
}
spin_unlock(&ubi->wl_lock);
vol_id = lnum ? UBI_FM_DATA_VOLUME_ID : UBI_FM_SB_VOLUME_ID;
return schedule_erase(ubi, e, vol_id, lnum, torture);
}
/**
* ubi_is_erase_work - checks whether a work is erase work.
* @wrk: The work object to be checked
*/
int ubi_is_erase_work(struct ubi_work *wrk)
{
return wrk->func == erase_worker;
}
static void ubi_fastmap_close(struct ubi_device *ubi)
{
int i;
return_unused_pool_pebs(ubi, &ubi->fm_pool);
return_unused_pool_pebs(ubi, &ubi->fm_wl_pool);
if (ubi->fm) {
for (i = 0; i < ubi->fm->used_blocks; i++)
kfree(ubi->fm->e[i]);
}
kfree(ubi->fm);
}
/**
* may_reserve_for_fm - tests whether a PEB shall be reserved for fastmap.
* See find_mean_wl_entry()
*
* @ubi: UBI device description object
* @e: physical eraseblock to return
* @root: RB tree to test against.
*/
static struct ubi_wl_entry *may_reserve_for_fm(struct ubi_device *ubi,
struct ubi_wl_entry *e,
struct rb_root *root) {
if (e && !ubi->fm_disabled && !ubi->fm &&
e->pnum < UBI_FM_MAX_START)
e = rb_entry(rb_next(root->rb_node),
struct ubi_wl_entry, u.rb);
return e;
}