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413 lines
9.6 KiB
413 lines
9.6 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (c) 2012 Linutronix GmbH |
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* Copyright (c) 2014 sigma star gmbh |
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* Author: Richard Weinberger <[email protected]> |
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*/ |
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/** |
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* update_fastmap_work_fn - calls ubi_update_fastmap from a work queue |
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* @wrk: the work description object |
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*/ |
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static void update_fastmap_work_fn(struct work_struct *wrk) |
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{ |
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struct ubi_device *ubi = container_of(wrk, struct ubi_device, fm_work); |
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ubi_update_fastmap(ubi); |
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spin_lock(&ubi->wl_lock); |
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ubi->fm_work_scheduled = 0; |
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spin_unlock(&ubi->wl_lock); |
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} |
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/** |
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* find_anchor_wl_entry - find wear-leveling entry to used as anchor PEB. |
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* @root: the RB-tree where to look for |
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*/ |
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static struct ubi_wl_entry *find_anchor_wl_entry(struct rb_root *root) |
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{ |
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struct rb_node *p; |
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struct ubi_wl_entry *e, *victim = NULL; |
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int max_ec = UBI_MAX_ERASECOUNTER; |
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ubi_rb_for_each_entry(p, e, root, u.rb) { |
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if (e->pnum < UBI_FM_MAX_START && e->ec < max_ec) { |
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victim = e; |
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max_ec = e->ec; |
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} |
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} |
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return victim; |
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} |
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static inline void return_unused_peb(struct ubi_device *ubi, |
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struct ubi_wl_entry *e) |
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{ |
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wl_tree_add(e, &ubi->free); |
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ubi->free_count++; |
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} |
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/** |
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* return_unused_pool_pebs - returns unused PEB to the free tree. |
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* @ubi: UBI device description object |
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* @pool: fastmap pool description object |
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*/ |
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static void return_unused_pool_pebs(struct ubi_device *ubi, |
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struct ubi_fm_pool *pool) |
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{ |
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int i; |
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struct ubi_wl_entry *e; |
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for (i = pool->used; i < pool->size; i++) { |
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e = ubi->lookuptbl[pool->pebs[i]]; |
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return_unused_peb(ubi, e); |
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} |
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} |
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/** |
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* ubi_wl_get_fm_peb - find a physical erase block with a given maximal number. |
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* @ubi: UBI device description object |
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* @anchor: This PEB will be used as anchor PEB by fastmap |
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* |
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* The function returns a physical erase block with a given maximal number |
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* and removes it from the wl subsystem. |
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* Must be called with wl_lock held! |
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*/ |
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struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor) |
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{ |
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struct ubi_wl_entry *e = NULL; |
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if (!ubi->free.rb_node || (ubi->free_count - ubi->beb_rsvd_pebs < 1)) |
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goto out; |
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if (anchor) |
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e = find_anchor_wl_entry(&ubi->free); |
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else |
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e = find_mean_wl_entry(ubi, &ubi->free); |
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if (!e) |
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goto out; |
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self_check_in_wl_tree(ubi, e, &ubi->free); |
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/* remove it from the free list, |
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* the wl subsystem does no longer know this erase block */ |
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rb_erase(&e->u.rb, &ubi->free); |
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ubi->free_count--; |
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out: |
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return e; |
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} |
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/** |
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* ubi_refill_pools - refills all fastmap PEB pools. |
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* @ubi: UBI device description object |
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*/ |
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void ubi_refill_pools(struct ubi_device *ubi) |
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{ |
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struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool; |
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struct ubi_fm_pool *pool = &ubi->fm_pool; |
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struct ubi_wl_entry *e; |
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int enough; |
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spin_lock(&ubi->wl_lock); |
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return_unused_pool_pebs(ubi, wl_pool); |
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return_unused_pool_pebs(ubi, pool); |
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wl_pool->size = 0; |
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pool->size = 0; |
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if (ubi->fm_anchor) { |
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wl_tree_add(ubi->fm_anchor, &ubi->free); |
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ubi->free_count++; |
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} |
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if (ubi->fm_next_anchor) { |
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wl_tree_add(ubi->fm_next_anchor, &ubi->free); |
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ubi->free_count++; |
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} |
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/* All available PEBs are in ubi->free, now is the time to get |
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* the best anchor PEBs. |
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*/ |
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ubi->fm_anchor = ubi_wl_get_fm_peb(ubi, 1); |
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ubi->fm_next_anchor = ubi_wl_get_fm_peb(ubi, 1); |
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for (;;) { |
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enough = 0; |
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if (pool->size < pool->max_size) { |
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if (!ubi->free.rb_node) |
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break; |
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e = wl_get_wle(ubi); |
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if (!e) |
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break; |
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pool->pebs[pool->size] = e->pnum; |
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pool->size++; |
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} else |
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enough++; |
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if (wl_pool->size < wl_pool->max_size) { |
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if (!ubi->free.rb_node || |
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(ubi->free_count - ubi->beb_rsvd_pebs < 5)) |
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break; |
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e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF); |
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self_check_in_wl_tree(ubi, e, &ubi->free); |
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rb_erase(&e->u.rb, &ubi->free); |
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ubi->free_count--; |
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wl_pool->pebs[wl_pool->size] = e->pnum; |
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wl_pool->size++; |
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} else |
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enough++; |
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if (enough == 2) |
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break; |
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} |
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wl_pool->used = 0; |
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pool->used = 0; |
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spin_unlock(&ubi->wl_lock); |
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} |
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/** |
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* produce_free_peb - produce a free physical eraseblock. |
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* @ubi: UBI device description object |
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* |
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* This function tries to make a free PEB by means of synchronous execution of |
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* pending works. This may be needed if, for example the background thread is |
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* disabled. Returns zero in case of success and a negative error code in case |
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* of failure. |
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*/ |
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static int produce_free_peb(struct ubi_device *ubi) |
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{ |
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int err; |
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while (!ubi->free.rb_node && ubi->works_count) { |
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dbg_wl("do one work synchronously"); |
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err = do_work(ubi); |
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if (err) |
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return err; |
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} |
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return 0; |
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} |
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/** |
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* ubi_wl_get_peb - get a physical eraseblock. |
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* @ubi: UBI device description object |
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* |
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* This function returns a physical eraseblock in case of success and a |
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* negative error code in case of failure. |
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* Returns with ubi->fm_eba_sem held in read mode! |
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*/ |
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int ubi_wl_get_peb(struct ubi_device *ubi) |
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{ |
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int ret, attempts = 0; |
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struct ubi_fm_pool *pool = &ubi->fm_pool; |
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struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool; |
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again: |
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down_read(&ubi->fm_eba_sem); |
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spin_lock(&ubi->wl_lock); |
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/* We check here also for the WL pool because at this point we can |
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* refill the WL pool synchronous. */ |
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if (pool->used == pool->size || wl_pool->used == wl_pool->size) { |
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spin_unlock(&ubi->wl_lock); |
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up_read(&ubi->fm_eba_sem); |
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ret = ubi_update_fastmap(ubi); |
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if (ret) { |
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ubi_msg(ubi, "Unable to write a new fastmap: %i", ret); |
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down_read(&ubi->fm_eba_sem); |
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return -ENOSPC; |
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} |
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down_read(&ubi->fm_eba_sem); |
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spin_lock(&ubi->wl_lock); |
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} |
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if (pool->used == pool->size) { |
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spin_unlock(&ubi->wl_lock); |
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attempts++; |
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if (attempts == 10) { |
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ubi_err(ubi, "Unable to get a free PEB from user WL pool"); |
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ret = -ENOSPC; |
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goto out; |
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} |
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up_read(&ubi->fm_eba_sem); |
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ret = produce_free_peb(ubi); |
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if (ret < 0) { |
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down_read(&ubi->fm_eba_sem); |
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goto out; |
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} |
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goto again; |
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} |
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ubi_assert(pool->used < pool->size); |
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ret = pool->pebs[pool->used++]; |
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prot_queue_add(ubi, ubi->lookuptbl[ret]); |
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spin_unlock(&ubi->wl_lock); |
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out: |
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return ret; |
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} |
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/* get_peb_for_wl - returns a PEB to be used internally by the WL sub-system. |
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* |
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* @ubi: UBI device description object |
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*/ |
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static struct ubi_wl_entry *get_peb_for_wl(struct ubi_device *ubi) |
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{ |
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struct ubi_fm_pool *pool = &ubi->fm_wl_pool; |
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int pnum; |
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ubi_assert(rwsem_is_locked(&ubi->fm_eba_sem)); |
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if (pool->used == pool->size) { |
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/* We cannot update the fastmap here because this |
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* function is called in atomic context. |
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* Let's fail here and refill/update it as soon as possible. */ |
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if (!ubi->fm_work_scheduled) { |
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ubi->fm_work_scheduled = 1; |
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schedule_work(&ubi->fm_work); |
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} |
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return NULL; |
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} |
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pnum = pool->pebs[pool->used++]; |
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return ubi->lookuptbl[pnum]; |
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} |
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/** |
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* ubi_ensure_anchor_pebs - schedule wear-leveling to produce an anchor PEB. |
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* @ubi: UBI device description object |
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*/ |
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int ubi_ensure_anchor_pebs(struct ubi_device *ubi) |
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{ |
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struct ubi_work *wrk; |
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spin_lock(&ubi->wl_lock); |
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/* Do we have a next anchor? */ |
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if (!ubi->fm_next_anchor) { |
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ubi->fm_next_anchor = ubi_wl_get_fm_peb(ubi, 1); |
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if (!ubi->fm_next_anchor) |
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/* Tell wear leveling to produce a new anchor PEB */ |
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ubi->fm_do_produce_anchor = 1; |
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} |
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/* Do wear leveling to get a new anchor PEB or check the |
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* existing next anchor candidate. |
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*/ |
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if (ubi->wl_scheduled) { |
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spin_unlock(&ubi->wl_lock); |
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return 0; |
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} |
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ubi->wl_scheduled = 1; |
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spin_unlock(&ubi->wl_lock); |
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wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS); |
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if (!wrk) { |
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spin_lock(&ubi->wl_lock); |
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ubi->wl_scheduled = 0; |
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spin_unlock(&ubi->wl_lock); |
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return -ENOMEM; |
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} |
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wrk->func = &wear_leveling_worker; |
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__schedule_ubi_work(ubi, wrk); |
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return 0; |
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} |
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/** |
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* ubi_wl_put_fm_peb - returns a PEB used in a fastmap to the wear-leveling |
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* sub-system. |
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* see: ubi_wl_put_peb() |
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* |
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* @ubi: UBI device description object |
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* @fm_e: physical eraseblock to return |
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* @lnum: the last used logical eraseblock number for the PEB |
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* @torture: if this physical eraseblock has to be tortured |
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*/ |
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int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *fm_e, |
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int lnum, int torture) |
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{ |
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struct ubi_wl_entry *e; |
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int vol_id, pnum = fm_e->pnum; |
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dbg_wl("PEB %d", pnum); |
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ubi_assert(pnum >= 0); |
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ubi_assert(pnum < ubi->peb_count); |
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spin_lock(&ubi->wl_lock); |
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e = ubi->lookuptbl[pnum]; |
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/* This can happen if we recovered from a fastmap the very |
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* first time and writing now a new one. In this case the wl system |
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* has never seen any PEB used by the original fastmap. |
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*/ |
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if (!e) { |
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e = fm_e; |
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ubi_assert(e->ec >= 0); |
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ubi->lookuptbl[pnum] = e; |
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} |
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spin_unlock(&ubi->wl_lock); |
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vol_id = lnum ? UBI_FM_DATA_VOLUME_ID : UBI_FM_SB_VOLUME_ID; |
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return schedule_erase(ubi, e, vol_id, lnum, torture, true); |
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} |
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/** |
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* ubi_is_erase_work - checks whether a work is erase work. |
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* @wrk: The work object to be checked |
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*/ |
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int ubi_is_erase_work(struct ubi_work *wrk) |
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{ |
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return wrk->func == erase_worker; |
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} |
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static void ubi_fastmap_close(struct ubi_device *ubi) |
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{ |
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int i; |
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return_unused_pool_pebs(ubi, &ubi->fm_pool); |
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return_unused_pool_pebs(ubi, &ubi->fm_wl_pool); |
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if (ubi->fm_anchor) { |
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return_unused_peb(ubi, ubi->fm_anchor); |
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ubi->fm_anchor = NULL; |
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} |
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if (ubi->fm_next_anchor) { |
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return_unused_peb(ubi, ubi->fm_next_anchor); |
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ubi->fm_next_anchor = NULL; |
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} |
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if (ubi->fm) { |
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for (i = 0; i < ubi->fm->used_blocks; i++) |
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kfree(ubi->fm->e[i]); |
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} |
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kfree(ubi->fm); |
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} |
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/** |
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* may_reserve_for_fm - tests whether a PEB shall be reserved for fastmap. |
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* See find_mean_wl_entry() |
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* |
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* @ubi: UBI device description object |
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* @e: physical eraseblock to return |
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* @root: RB tree to test against. |
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*/ |
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static struct ubi_wl_entry *may_reserve_for_fm(struct ubi_device *ubi, |
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struct ubi_wl_entry *e, |
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struct rb_root *root) { |
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if (e && !ubi->fm_disabled && !ubi->fm && |
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e->pnum < UBI_FM_MAX_START) |
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e = rb_entry(rb_next(root->rb_node), |
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struct ubi_wl_entry, u.rb); |
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return e; |
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}
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