![shengyong](/assets/img/avatar_default.png)
Signed-off-by: Sheng Yong <shengyong1@huawei.com> Signed-off-by: Richard Weinberger <richard@nod.at>
1845 lines
49 KiB
C
1845 lines
49 KiB
C
/*
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* Copyright (c) International Business Machines Corp., 2006
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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* the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* Authors: Artem Bityutskiy (Битюцкий Артём), Thomas Gleixner
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*/
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/*
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* UBI wear-leveling sub-system.
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*
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* This sub-system is responsible for wear-leveling. It works in terms of
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* physical eraseblocks and erase counters and knows nothing about logical
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* eraseblocks, volumes, etc. From this sub-system's perspective all physical
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* eraseblocks are of two types - used and free. Used physical eraseblocks are
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* those that were "get" by the 'ubi_wl_get_peb()' function, and free physical
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* eraseblocks are those that were put by the 'ubi_wl_put_peb()' function.
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*
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* Physical eraseblocks returned by 'ubi_wl_get_peb()' have only erase counter
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* header. The rest of the physical eraseblock contains only %0xFF bytes.
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*
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* When physical eraseblocks are returned to the WL sub-system by means of the
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* 'ubi_wl_put_peb()' function, they are scheduled for erasure. The erasure is
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* done asynchronously in context of the per-UBI device background thread,
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* which is also managed by the WL sub-system.
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*
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* The wear-leveling is ensured by means of moving the contents of used
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* physical eraseblocks with low erase counter to free physical eraseblocks
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* with high erase counter.
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*
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* If the WL sub-system fails to erase a physical eraseblock, it marks it as
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* bad.
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*
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* This sub-system is also responsible for scrubbing. If a bit-flip is detected
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* in a physical eraseblock, it has to be moved. Technically this is the same
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* as moving it for wear-leveling reasons.
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*
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* As it was said, for the UBI sub-system all physical eraseblocks are either
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* "free" or "used". Free eraseblock are kept in the @wl->free RB-tree, while
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* used eraseblocks are kept in @wl->used, @wl->erroneous, or @wl->scrub
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* RB-trees, as well as (temporarily) in the @wl->pq queue.
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*
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* When the WL sub-system returns a physical eraseblock, the physical
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* eraseblock is protected from being moved for some "time". For this reason,
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* the physical eraseblock is not directly moved from the @wl->free tree to the
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* @wl->used tree. There is a protection queue in between where this
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* physical eraseblock is temporarily stored (@wl->pq).
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*
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* All this protection stuff is needed because:
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* o we don't want to move physical eraseblocks just after we have given them
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* to the user; instead, we first want to let users fill them up with data;
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*
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* o there is a chance that the user will put the physical eraseblock very
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* soon, so it makes sense not to move it for some time, but wait.
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*
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* Physical eraseblocks stay protected only for limited time. But the "time" is
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* measured in erase cycles in this case. This is implemented with help of the
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* protection queue. Eraseblocks are put to the tail of this queue when they
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* are returned by the 'ubi_wl_get_peb()', and eraseblocks are removed from the
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* head of the queue on each erase operation (for any eraseblock). So the
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* length of the queue defines how may (global) erase cycles PEBs are protected.
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*
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* To put it differently, each physical eraseblock has 2 main states: free and
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* used. The former state corresponds to the @wl->free tree. The latter state
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* is split up on several sub-states:
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* o the WL movement is allowed (@wl->used tree);
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* o the WL movement is disallowed (@wl->erroneous) because the PEB is
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* erroneous - e.g., there was a read error;
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* o the WL movement is temporarily prohibited (@wl->pq queue);
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* o scrubbing is needed (@wl->scrub tree).
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*
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* Depending on the sub-state, wear-leveling entries of the used physical
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* eraseblocks may be kept in one of those structures.
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*
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* Note, in this implementation, we keep a small in-RAM object for each physical
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* eraseblock. This is surely not a scalable solution. But it appears to be good
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* enough for moderately large flashes and it is simple. In future, one may
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* re-work this sub-system and make it more scalable.
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*
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* At the moment this sub-system does not utilize the sequence number, which
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* was introduced relatively recently. But it would be wise to do this because
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* the sequence number of a logical eraseblock characterizes how old is it. For
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* example, when we move a PEB with low erase counter, and we need to pick the
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* target PEB, we pick a PEB with the highest EC if our PEB is "old" and we
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* pick target PEB with an average EC if our PEB is not very "old". This is a
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* room for future re-works of the WL sub-system.
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*/
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#include <linux/slab.h>
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#include <linux/crc32.h>
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#include <linux/freezer.h>
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#include <linux/kthread.h>
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#include "ubi.h"
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#include "wl.h"
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/* Number of physical eraseblocks reserved for wear-leveling purposes */
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#define WL_RESERVED_PEBS 1
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/*
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* Maximum difference between two erase counters. If this threshold is
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* exceeded, the WL sub-system starts moving data from used physical
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* eraseblocks with low erase counter to free physical eraseblocks with high
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* erase counter.
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*/
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#define UBI_WL_THRESHOLD CONFIG_MTD_UBI_WL_THRESHOLD
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/*
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* When a physical eraseblock is moved, the WL sub-system has to pick the target
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* physical eraseblock to move to. The simplest way would be just to pick the
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* one with the highest erase counter. But in certain workloads this could lead
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* to an unlimited wear of one or few physical eraseblock. Indeed, imagine a
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* situation when the picked physical eraseblock is constantly erased after the
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* data is written to it. So, we have a constant which limits the highest erase
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* counter of the free physical eraseblock to pick. Namely, the WL sub-system
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* does not pick eraseblocks with erase counter greater than the lowest erase
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* counter plus %WL_FREE_MAX_DIFF.
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*/
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#define WL_FREE_MAX_DIFF (2*UBI_WL_THRESHOLD)
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/*
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* Maximum number of consecutive background thread failures which is enough to
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* switch to read-only mode.
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*/
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#define WL_MAX_FAILURES 32
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static int self_check_ec(struct ubi_device *ubi, int pnum, int ec);
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static int self_check_in_wl_tree(const struct ubi_device *ubi,
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struct ubi_wl_entry *e, struct rb_root *root);
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static int self_check_in_pq(const struct ubi_device *ubi,
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struct ubi_wl_entry *e);
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/**
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* wl_tree_add - add a wear-leveling entry to a WL RB-tree.
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* @e: the wear-leveling entry to add
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* @root: the root of the tree
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*
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* Note, we use (erase counter, physical eraseblock number) pairs as keys in
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* the @ubi->used and @ubi->free RB-trees.
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*/
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static void wl_tree_add(struct ubi_wl_entry *e, struct rb_root *root)
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{
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struct rb_node **p, *parent = NULL;
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p = &root->rb_node;
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while (*p) {
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struct ubi_wl_entry *e1;
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parent = *p;
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e1 = rb_entry(parent, struct ubi_wl_entry, u.rb);
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if (e->ec < e1->ec)
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p = &(*p)->rb_left;
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else if (e->ec > e1->ec)
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p = &(*p)->rb_right;
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else {
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ubi_assert(e->pnum != e1->pnum);
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if (e->pnum < e1->pnum)
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p = &(*p)->rb_left;
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else
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p = &(*p)->rb_right;
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}
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}
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rb_link_node(&e->u.rb, parent, p);
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rb_insert_color(&e->u.rb, root);
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}
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/**
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* wl_tree_destroy - destroy a wear-leveling entry.
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* @ubi: UBI device description object
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* @e: the wear-leveling entry to add
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*
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* This function destroys a wear leveling entry and removes
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* the reference from the lookup table.
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*/
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static void wl_entry_destroy(struct ubi_device *ubi, struct ubi_wl_entry *e)
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{
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ubi->lookuptbl[e->pnum] = NULL;
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kmem_cache_free(ubi_wl_entry_slab, e);
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}
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/**
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* do_work - do one pending work.
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* @ubi: UBI device description object
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*
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* This function returns zero in case of success and a negative error code in
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* case of failure.
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*/
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static int do_work(struct ubi_device *ubi)
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{
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int err;
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struct ubi_work *wrk;
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cond_resched();
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/*
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* @ubi->work_sem is used to synchronize with the workers. Workers take
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* it in read mode, so many of them may be doing works at a time. But
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* the queue flush code has to be sure the whole queue of works is
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* done, and it takes the mutex in write mode.
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*/
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down_read(&ubi->work_sem);
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spin_lock(&ubi->wl_lock);
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if (list_empty(&ubi->works)) {
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spin_unlock(&ubi->wl_lock);
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up_read(&ubi->work_sem);
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return 0;
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}
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wrk = list_entry(ubi->works.next, struct ubi_work, list);
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list_del(&wrk->list);
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ubi->works_count -= 1;
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ubi_assert(ubi->works_count >= 0);
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spin_unlock(&ubi->wl_lock);
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/*
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* Call the worker function. Do not touch the work structure
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* after this call as it will have been freed or reused by that
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* time by the worker function.
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*/
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err = wrk->func(ubi, wrk, 0);
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if (err)
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ubi_err(ubi, "work failed with error code %d", err);
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up_read(&ubi->work_sem);
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return err;
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}
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/**
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* in_wl_tree - check if wear-leveling entry is present in a WL RB-tree.
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* @e: the wear-leveling entry to check
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* @root: the root of the tree
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*
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* This function returns non-zero if @e is in the @root RB-tree and zero if it
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* is not.
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*/
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static int in_wl_tree(struct ubi_wl_entry *e, struct rb_root *root)
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{
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struct rb_node *p;
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p = root->rb_node;
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while (p) {
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struct ubi_wl_entry *e1;
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e1 = rb_entry(p, struct ubi_wl_entry, u.rb);
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if (e->pnum == e1->pnum) {
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ubi_assert(e == e1);
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return 1;
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}
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if (e->ec < e1->ec)
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p = p->rb_left;
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else if (e->ec > e1->ec)
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p = p->rb_right;
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else {
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ubi_assert(e->pnum != e1->pnum);
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if (e->pnum < e1->pnum)
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p = p->rb_left;
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else
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p = p->rb_right;
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}
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}
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return 0;
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}
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/**
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* prot_queue_add - add physical eraseblock to the protection queue.
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* @ubi: UBI device description object
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* @e: the physical eraseblock to add
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*
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* This function adds @e to the tail of the protection queue @ubi->pq, where
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* @e will stay for %UBI_PROT_QUEUE_LEN erase operations and will be
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* temporarily protected from the wear-leveling worker. Note, @wl->lock has to
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* be locked.
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*/
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static void prot_queue_add(struct ubi_device *ubi, struct ubi_wl_entry *e)
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{
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int pq_tail = ubi->pq_head - 1;
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if (pq_tail < 0)
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pq_tail = UBI_PROT_QUEUE_LEN - 1;
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ubi_assert(pq_tail >= 0 && pq_tail < UBI_PROT_QUEUE_LEN);
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list_add_tail(&e->u.list, &ubi->pq[pq_tail]);
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dbg_wl("added PEB %d EC %d to the protection queue", e->pnum, e->ec);
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}
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/**
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* find_wl_entry - find wear-leveling entry closest to certain erase counter.
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* @ubi: UBI device description object
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* @root: the RB-tree where to look for
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* @diff: maximum possible difference from the smallest erase counter
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*
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* This function looks for a wear leveling entry with erase counter closest to
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* min + @diff, where min is the smallest erase counter.
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*/
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static struct ubi_wl_entry *find_wl_entry(struct ubi_device *ubi,
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struct rb_root *root, int diff)
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{
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struct rb_node *p;
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struct ubi_wl_entry *e, *prev_e = NULL;
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int max;
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e = rb_entry(rb_first(root), struct ubi_wl_entry, u.rb);
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max = e->ec + diff;
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p = root->rb_node;
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while (p) {
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struct ubi_wl_entry *e1;
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e1 = rb_entry(p, struct ubi_wl_entry, u.rb);
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if (e1->ec >= max)
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p = p->rb_left;
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else {
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p = p->rb_right;
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prev_e = e;
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e = e1;
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}
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}
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/* If no fastmap has been written and this WL entry can be used
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* as anchor PEB, hold it back and return the second best WL entry
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* such that fastmap can use the anchor PEB later. */
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if (prev_e && !ubi->fm_disabled &&
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!ubi->fm && e->pnum < UBI_FM_MAX_START)
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return prev_e;
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return e;
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}
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/**
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* find_mean_wl_entry - find wear-leveling entry with medium erase counter.
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* @ubi: UBI device description object
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* @root: the RB-tree where to look for
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*
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* This function looks for a wear leveling entry with medium erase counter,
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* but not greater or equivalent than the lowest erase counter plus
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* %WL_FREE_MAX_DIFF/2.
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*/
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static struct ubi_wl_entry *find_mean_wl_entry(struct ubi_device *ubi,
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struct rb_root *root)
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{
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struct ubi_wl_entry *e, *first, *last;
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first = rb_entry(rb_first(root), struct ubi_wl_entry, u.rb);
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last = rb_entry(rb_last(root), struct ubi_wl_entry, u.rb);
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if (last->ec - first->ec < WL_FREE_MAX_DIFF) {
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e = rb_entry(root->rb_node, struct ubi_wl_entry, u.rb);
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/* If no fastmap has been written and this WL entry can be used
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* as anchor PEB, hold it back and return the second best
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* WL entry such that fastmap can use the anchor PEB later. */
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e = may_reserve_for_fm(ubi, e, root);
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} else
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e = find_wl_entry(ubi, root, WL_FREE_MAX_DIFF/2);
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return e;
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}
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/**
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* wl_get_wle - get a mean wl entry to be used by ubi_wl_get_peb() or
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* refill_wl_user_pool().
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* @ubi: UBI device description object
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*
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* This function returns a a wear leveling entry in case of success and
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* NULL in case of failure.
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*/
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static struct ubi_wl_entry *wl_get_wle(struct ubi_device *ubi)
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{
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struct ubi_wl_entry *e;
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e = find_mean_wl_entry(ubi, &ubi->free);
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if (!e) {
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ubi_err(ubi, "no free eraseblocks");
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return NULL;
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}
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self_check_in_wl_tree(ubi, e, &ubi->free);
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/*
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* Move the physical eraseblock to the protection queue where it will
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* be protected from being moved for some time.
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*/
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rb_erase(&e->u.rb, &ubi->free);
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ubi->free_count--;
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dbg_wl("PEB %d EC %d", e->pnum, e->ec);
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return e;
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}
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/**
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* prot_queue_del - remove a physical eraseblock from the protection queue.
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* @ubi: UBI device description object
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* @pnum: the physical eraseblock to remove
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*
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* This function deletes PEB @pnum from the protection queue and returns zero
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* in case of success and %-ENODEV if the PEB was not found.
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*/
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static int prot_queue_del(struct ubi_device *ubi, int pnum)
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{
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struct ubi_wl_entry *e;
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e = ubi->lookuptbl[pnum];
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if (!e)
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return -ENODEV;
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if (self_check_in_pq(ubi, e))
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return -ENODEV;
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list_del(&e->u.list);
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dbg_wl("deleted PEB %d from the protection queue", e->pnum);
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return 0;
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}
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/**
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* sync_erase - synchronously erase a physical eraseblock.
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* @ubi: UBI device description object
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* @e: the the physical eraseblock to erase
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* @torture: if the physical eraseblock has to be tortured
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*
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* This function returns zero in case of success and a negative error code in
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* case of failure.
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*/
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static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
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int torture)
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{
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int err;
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struct ubi_ec_hdr *ec_hdr;
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unsigned long long ec = e->ec;
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dbg_wl("erase PEB %d, old EC %llu", e->pnum, ec);
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err = self_check_ec(ubi, e->pnum, e->ec);
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if (err)
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return -EINVAL;
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ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
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if (!ec_hdr)
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return -ENOMEM;
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err = ubi_io_sync_erase(ubi, e->pnum, torture);
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if (err < 0)
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goto out_free;
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ec += err;
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if (ec > UBI_MAX_ERASECOUNTER) {
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/*
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* Erase counter overflow. Upgrade UBI and use 64-bit
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* erase counters internally.
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*/
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ubi_err(ubi, "erase counter overflow at PEB %d, EC %llu",
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e->pnum, ec);
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err = -EINVAL;
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goto out_free;
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}
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|
|
dbg_wl("erased PEB %d, new EC %llu", e->pnum, ec);
|
|
|
|
ec_hdr->ec = cpu_to_be64(ec);
|
|
|
|
err = ubi_io_write_ec_hdr(ubi, e->pnum, ec_hdr);
|
|
if (err)
|
|
goto out_free;
|
|
|
|
e->ec = ec;
|
|
spin_lock(&ubi->wl_lock);
|
|
if (e->ec > ubi->max_ec)
|
|
ubi->max_ec = e->ec;
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
out_free:
|
|
kfree(ec_hdr);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* serve_prot_queue - check if it is time to stop protecting PEBs.
|
|
* @ubi: UBI device description object
|
|
*
|
|
* This function is called after each erase operation and removes PEBs from the
|
|
* tail of the protection queue. These PEBs have been protected for long enough
|
|
* and should be moved to the used tree.
|
|
*/
|
|
static void serve_prot_queue(struct ubi_device *ubi)
|
|
{
|
|
struct ubi_wl_entry *e, *tmp;
|
|
int count;
|
|
|
|
/*
|
|
* There may be several protected physical eraseblock to remove,
|
|
* process them all.
|
|
*/
|
|
repeat:
|
|
count = 0;
|
|
spin_lock(&ubi->wl_lock);
|
|
list_for_each_entry_safe(e, tmp, &ubi->pq[ubi->pq_head], u.list) {
|
|
dbg_wl("PEB %d EC %d protection over, move to used tree",
|
|
e->pnum, e->ec);
|
|
|
|
list_del(&e->u.list);
|
|
wl_tree_add(e, &ubi->used);
|
|
if (count++ > 32) {
|
|
/*
|
|
* Let's be nice and avoid holding the spinlock for
|
|
* too long.
|
|
*/
|
|
spin_unlock(&ubi->wl_lock);
|
|
cond_resched();
|
|
goto repeat;
|
|
}
|
|
}
|
|
|
|
ubi->pq_head += 1;
|
|
if (ubi->pq_head == UBI_PROT_QUEUE_LEN)
|
|
ubi->pq_head = 0;
|
|
ubi_assert(ubi->pq_head >= 0 && ubi->pq_head < UBI_PROT_QUEUE_LEN);
|
|
spin_unlock(&ubi->wl_lock);
|
|
}
|
|
|
|
/**
|
|
* __schedule_ubi_work - schedule a work.
|
|
* @ubi: UBI device description object
|
|
* @wrk: the work to schedule
|
|
*
|
|
* This function adds a work defined by @wrk to the tail of the pending works
|
|
* list. Can only be used if ubi->work_sem is already held in read mode!
|
|
*/
|
|
static void __schedule_ubi_work(struct ubi_device *ubi, struct ubi_work *wrk)
|
|
{
|
|
spin_lock(&ubi->wl_lock);
|
|
list_add_tail(&wrk->list, &ubi->works);
|
|
ubi_assert(ubi->works_count >= 0);
|
|
ubi->works_count += 1;
|
|
if (ubi->thread_enabled && !ubi_dbg_is_bgt_disabled(ubi))
|
|
wake_up_process(ubi->bgt_thread);
|
|
spin_unlock(&ubi->wl_lock);
|
|
}
|
|
|
|
/**
|
|
* schedule_ubi_work - schedule a work.
|
|
* @ubi: UBI device description object
|
|
* @wrk: the work to schedule
|
|
*
|
|
* This function adds a work defined by @wrk to the tail of the pending works
|
|
* list.
|
|
*/
|
|
static void schedule_ubi_work(struct ubi_device *ubi, struct ubi_work *wrk)
|
|
{
|
|
down_read(&ubi->work_sem);
|
|
__schedule_ubi_work(ubi, wrk);
|
|
up_read(&ubi->work_sem);
|
|
}
|
|
|
|
static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
|
|
int shutdown);
|
|
|
|
/**
|
|
* schedule_erase - schedule an erase work.
|
|
* @ubi: UBI device description object
|
|
* @e: the WL entry of the physical eraseblock to erase
|
|
* @vol_id: the volume ID that last used this PEB
|
|
* @lnum: the last used logical eraseblock number for the PEB
|
|
* @torture: if the physical eraseblock has to be tortured
|
|
*
|
|
* This function returns zero in case of success and a %-ENOMEM in case of
|
|
* failure.
|
|
*/
|
|
static int schedule_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
|
|
int vol_id, int lnum, int torture)
|
|
{
|
|
struct ubi_work *wl_wrk;
|
|
|
|
ubi_assert(e);
|
|
|
|
dbg_wl("schedule erasure of PEB %d, EC %d, torture %d",
|
|
e->pnum, e->ec, torture);
|
|
|
|
wl_wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS);
|
|
if (!wl_wrk)
|
|
return -ENOMEM;
|
|
|
|
wl_wrk->func = &erase_worker;
|
|
wl_wrk->e = e;
|
|
wl_wrk->vol_id = vol_id;
|
|
wl_wrk->lnum = lnum;
|
|
wl_wrk->torture = torture;
|
|
|
|
schedule_ubi_work(ubi, wl_wrk);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* do_sync_erase - run the erase worker synchronously.
|
|
* @ubi: UBI device description object
|
|
* @e: the WL entry of the physical eraseblock to erase
|
|
* @vol_id: the volume ID that last used this PEB
|
|
* @lnum: the last used logical eraseblock number for the PEB
|
|
* @torture: if the physical eraseblock has to be tortured
|
|
*
|
|
*/
|
|
static int do_sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
|
|
int vol_id, int lnum, int torture)
|
|
{
|
|
struct ubi_work *wl_wrk;
|
|
|
|
dbg_wl("sync erase of PEB %i", e->pnum);
|
|
|
|
wl_wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS);
|
|
if (!wl_wrk)
|
|
return -ENOMEM;
|
|
|
|
wl_wrk->e = e;
|
|
wl_wrk->vol_id = vol_id;
|
|
wl_wrk->lnum = lnum;
|
|
wl_wrk->torture = torture;
|
|
|
|
return erase_worker(ubi, wl_wrk, 0);
|
|
}
|
|
|
|
/**
|
|
* wear_leveling_worker - wear-leveling worker function.
|
|
* @ubi: UBI device description object
|
|
* @wrk: the work object
|
|
* @shutdown: non-zero if the worker has to free memory and exit
|
|
* because the WL-subsystem is shutting down
|
|
*
|
|
* This function copies a more worn out physical eraseblock to a less worn out
|
|
* one. Returns zero in case of success and a negative error code in case of
|
|
* failure.
|
|
*/
|
|
static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
|
|
int shutdown)
|
|
{
|
|
int err, scrubbing = 0, torture = 0, protect = 0, erroneous = 0;
|
|
int vol_id = -1, lnum = -1;
|
|
#ifdef CONFIG_MTD_UBI_FASTMAP
|
|
int anchor = wrk->anchor;
|
|
#endif
|
|
struct ubi_wl_entry *e1, *e2;
|
|
struct ubi_vid_hdr *vid_hdr;
|
|
|
|
kfree(wrk);
|
|
if (shutdown)
|
|
return 0;
|
|
|
|
vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
|
|
if (!vid_hdr)
|
|
return -ENOMEM;
|
|
|
|
mutex_lock(&ubi->move_mutex);
|
|
spin_lock(&ubi->wl_lock);
|
|
ubi_assert(!ubi->move_from && !ubi->move_to);
|
|
ubi_assert(!ubi->move_to_put);
|
|
|
|
if (!ubi->free.rb_node ||
|
|
(!ubi->used.rb_node && !ubi->scrub.rb_node)) {
|
|
/*
|
|
* No free physical eraseblocks? Well, they must be waiting in
|
|
* the queue to be erased. Cancel movement - it will be
|
|
* triggered again when a free physical eraseblock appears.
|
|
*
|
|
* No used physical eraseblocks? They must be temporarily
|
|
* protected from being moved. They will be moved to the
|
|
* @ubi->used tree later and the wear-leveling will be
|
|
* triggered again.
|
|
*/
|
|
dbg_wl("cancel WL, a list is empty: free %d, used %d",
|
|
!ubi->free.rb_node, !ubi->used.rb_node);
|
|
goto out_cancel;
|
|
}
|
|
|
|
#ifdef CONFIG_MTD_UBI_FASTMAP
|
|
/* Check whether we need to produce an anchor PEB */
|
|
if (!anchor)
|
|
anchor = !anchor_pebs_avalible(&ubi->free);
|
|
|
|
if (anchor) {
|
|
e1 = find_anchor_wl_entry(&ubi->used);
|
|
if (!e1)
|
|
goto out_cancel;
|
|
e2 = get_peb_for_wl(ubi);
|
|
if (!e2)
|
|
goto out_cancel;
|
|
|
|
self_check_in_wl_tree(ubi, e1, &ubi->used);
|
|
rb_erase(&e1->u.rb, &ubi->used);
|
|
dbg_wl("anchor-move PEB %d to PEB %d", e1->pnum, e2->pnum);
|
|
} else if (!ubi->scrub.rb_node) {
|
|
#else
|
|
if (!ubi->scrub.rb_node) {
|
|
#endif
|
|
/*
|
|
* Now pick the least worn-out used physical eraseblock and a
|
|
* highly worn-out free physical eraseblock. If the erase
|
|
* counters differ much enough, start wear-leveling.
|
|
*/
|
|
e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, u.rb);
|
|
e2 = get_peb_for_wl(ubi);
|
|
if (!e2)
|
|
goto out_cancel;
|
|
|
|
if (!(e2->ec - e1->ec >= UBI_WL_THRESHOLD)) {
|
|
dbg_wl("no WL needed: min used EC %d, max free EC %d",
|
|
e1->ec, e2->ec);
|
|
|
|
/* Give the unused PEB back */
|
|
wl_tree_add(e2, &ubi->free);
|
|
ubi->free_count++;
|
|
goto out_cancel;
|
|
}
|
|
self_check_in_wl_tree(ubi, e1, &ubi->used);
|
|
rb_erase(&e1->u.rb, &ubi->used);
|
|
dbg_wl("move PEB %d EC %d to PEB %d EC %d",
|
|
e1->pnum, e1->ec, e2->pnum, e2->ec);
|
|
} else {
|
|
/* Perform scrubbing */
|
|
scrubbing = 1;
|
|
e1 = rb_entry(rb_first(&ubi->scrub), struct ubi_wl_entry, u.rb);
|
|
e2 = get_peb_for_wl(ubi);
|
|
if (!e2)
|
|
goto out_cancel;
|
|
|
|
self_check_in_wl_tree(ubi, e1, &ubi->scrub);
|
|
rb_erase(&e1->u.rb, &ubi->scrub);
|
|
dbg_wl("scrub PEB %d to PEB %d", e1->pnum, e2->pnum);
|
|
}
|
|
|
|
ubi->move_from = e1;
|
|
ubi->move_to = e2;
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
/*
|
|
* Now we are going to copy physical eraseblock @e1->pnum to @e2->pnum.
|
|
* We so far do not know which logical eraseblock our physical
|
|
* eraseblock (@e1) belongs to. We have to read the volume identifier
|
|
* header first.
|
|
*
|
|
* Note, we are protected from this PEB being unmapped and erased. The
|
|
* 'ubi_wl_put_peb()' would wait for moving to be finished if the PEB
|
|
* which is being moved was unmapped.
|
|
*/
|
|
|
|
err = ubi_io_read_vid_hdr(ubi, e1->pnum, vid_hdr, 0);
|
|
if (err && err != UBI_IO_BITFLIPS) {
|
|
if (err == UBI_IO_FF) {
|
|
/*
|
|
* We are trying to move PEB without a VID header. UBI
|
|
* always write VID headers shortly after the PEB was
|
|
* given, so we have a situation when it has not yet
|
|
* had a chance to write it, because it was preempted.
|
|
* So add this PEB to the protection queue so far,
|
|
* because presumably more data will be written there
|
|
* (including the missing VID header), and then we'll
|
|
* move it.
|
|
*/
|
|
dbg_wl("PEB %d has no VID header", e1->pnum);
|
|
protect = 1;
|
|
goto out_not_moved;
|
|
} else if (err == UBI_IO_FF_BITFLIPS) {
|
|
/*
|
|
* The same situation as %UBI_IO_FF, but bit-flips were
|
|
* detected. It is better to schedule this PEB for
|
|
* scrubbing.
|
|
*/
|
|
dbg_wl("PEB %d has no VID header but has bit-flips",
|
|
e1->pnum);
|
|
scrubbing = 1;
|
|
goto out_not_moved;
|
|
}
|
|
|
|
ubi_err(ubi, "error %d while reading VID header from PEB %d",
|
|
err, e1->pnum);
|
|
goto out_error;
|
|
}
|
|
|
|
vol_id = be32_to_cpu(vid_hdr->vol_id);
|
|
lnum = be32_to_cpu(vid_hdr->lnum);
|
|
|
|
err = ubi_eba_copy_leb(ubi, e1->pnum, e2->pnum, vid_hdr);
|
|
if (err) {
|
|
if (err == MOVE_CANCEL_RACE) {
|
|
/*
|
|
* The LEB has not been moved because the volume is
|
|
* being deleted or the PEB has been put meanwhile. We
|
|
* should prevent this PEB from being selected for
|
|
* wear-leveling movement again, so put it to the
|
|
* protection queue.
|
|
*/
|
|
protect = 1;
|
|
goto out_not_moved;
|
|
}
|
|
if (err == MOVE_RETRY) {
|
|
scrubbing = 1;
|
|
goto out_not_moved;
|
|
}
|
|
if (err == MOVE_TARGET_BITFLIPS || err == MOVE_TARGET_WR_ERR ||
|
|
err == MOVE_TARGET_RD_ERR) {
|
|
/*
|
|
* Target PEB had bit-flips or write error - torture it.
|
|
*/
|
|
torture = 1;
|
|
goto out_not_moved;
|
|
}
|
|
|
|
if (err == MOVE_SOURCE_RD_ERR) {
|
|
/*
|
|
* An error happened while reading the source PEB. Do
|
|
* not switch to R/O mode in this case, and give the
|
|
* upper layers a possibility to recover from this,
|
|
* e.g. by unmapping corresponding LEB. Instead, just
|
|
* put this PEB to the @ubi->erroneous list to prevent
|
|
* UBI from trying to move it over and over again.
|
|
*/
|
|
if (ubi->erroneous_peb_count > ubi->max_erroneous) {
|
|
ubi_err(ubi, "too many erroneous eraseblocks (%d)",
|
|
ubi->erroneous_peb_count);
|
|
goto out_error;
|
|
}
|
|
erroneous = 1;
|
|
goto out_not_moved;
|
|
}
|
|
|
|
if (err < 0)
|
|
goto out_error;
|
|
|
|
ubi_assert(0);
|
|
}
|
|
|
|
/* The PEB has been successfully moved */
|
|
if (scrubbing)
|
|
ubi_msg(ubi, "scrubbed PEB %d (LEB %d:%d), data moved to PEB %d",
|
|
e1->pnum, vol_id, lnum, e2->pnum);
|
|
ubi_free_vid_hdr(ubi, vid_hdr);
|
|
|
|
spin_lock(&ubi->wl_lock);
|
|
if (!ubi->move_to_put) {
|
|
wl_tree_add(e2, &ubi->used);
|
|
e2 = NULL;
|
|
}
|
|
ubi->move_from = ubi->move_to = NULL;
|
|
ubi->move_to_put = ubi->wl_scheduled = 0;
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
err = do_sync_erase(ubi, e1, vol_id, lnum, 0);
|
|
if (err) {
|
|
if (e2)
|
|
wl_entry_destroy(ubi, e2);
|
|
goto out_ro;
|
|
}
|
|
|
|
if (e2) {
|
|
/*
|
|
* Well, the target PEB was put meanwhile, schedule it for
|
|
* erasure.
|
|
*/
|
|
dbg_wl("PEB %d (LEB %d:%d) was put meanwhile, erase",
|
|
e2->pnum, vol_id, lnum);
|
|
err = do_sync_erase(ubi, e2, vol_id, lnum, 0);
|
|
if (err)
|
|
goto out_ro;
|
|
}
|
|
|
|
dbg_wl("done");
|
|
mutex_unlock(&ubi->move_mutex);
|
|
return 0;
|
|
|
|
/*
|
|
* For some reasons the LEB was not moved, might be an error, might be
|
|
* something else. @e1 was not changed, so return it back. @e2 might
|
|
* have been changed, schedule it for erasure.
|
|
*/
|
|
out_not_moved:
|
|
if (vol_id != -1)
|
|
dbg_wl("cancel moving PEB %d (LEB %d:%d) to PEB %d (%d)",
|
|
e1->pnum, vol_id, lnum, e2->pnum, err);
|
|
else
|
|
dbg_wl("cancel moving PEB %d to PEB %d (%d)",
|
|
e1->pnum, e2->pnum, err);
|
|
spin_lock(&ubi->wl_lock);
|
|
if (protect)
|
|
prot_queue_add(ubi, e1);
|
|
else if (erroneous) {
|
|
wl_tree_add(e1, &ubi->erroneous);
|
|
ubi->erroneous_peb_count += 1;
|
|
} else if (scrubbing)
|
|
wl_tree_add(e1, &ubi->scrub);
|
|
else
|
|
wl_tree_add(e1, &ubi->used);
|
|
ubi_assert(!ubi->move_to_put);
|
|
ubi->move_from = ubi->move_to = NULL;
|
|
ubi->wl_scheduled = 0;
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
ubi_free_vid_hdr(ubi, vid_hdr);
|
|
err = do_sync_erase(ubi, e2, vol_id, lnum, torture);
|
|
if (err)
|
|
goto out_ro;
|
|
|
|
mutex_unlock(&ubi->move_mutex);
|
|
return 0;
|
|
|
|
out_error:
|
|
if (vol_id != -1)
|
|
ubi_err(ubi, "error %d while moving PEB %d to PEB %d",
|
|
err, e1->pnum, e2->pnum);
|
|
else
|
|
ubi_err(ubi, "error %d while moving PEB %d (LEB %d:%d) to PEB %d",
|
|
err, e1->pnum, vol_id, lnum, e2->pnum);
|
|
spin_lock(&ubi->wl_lock);
|
|
ubi->move_from = ubi->move_to = NULL;
|
|
ubi->move_to_put = ubi->wl_scheduled = 0;
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
ubi_free_vid_hdr(ubi, vid_hdr);
|
|
wl_entry_destroy(ubi, e1);
|
|
wl_entry_destroy(ubi, e2);
|
|
|
|
out_ro:
|
|
ubi_ro_mode(ubi);
|
|
mutex_unlock(&ubi->move_mutex);
|
|
ubi_assert(err != 0);
|
|
return err < 0 ? err : -EIO;
|
|
|
|
out_cancel:
|
|
ubi->wl_scheduled = 0;
|
|
spin_unlock(&ubi->wl_lock);
|
|
mutex_unlock(&ubi->move_mutex);
|
|
ubi_free_vid_hdr(ubi, vid_hdr);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* ensure_wear_leveling - schedule wear-leveling if it is needed.
|
|
* @ubi: UBI device description object
|
|
* @nested: set to non-zero if this function is called from UBI worker
|
|
*
|
|
* This function checks if it is time to start wear-leveling and schedules it
|
|
* if yes. This function returns zero in case of success and a negative error
|
|
* code in case of failure.
|
|
*/
|
|
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);
|
|
if (ubi->wl_scheduled)
|
|
/* Wear-leveling is already in the work queue */
|
|
goto out_unlock;
|
|
|
|
/*
|
|
* If the ubi->scrub tree is not empty, scrubbing is needed, and the
|
|
* the WL worker has to be scheduled anyway.
|
|
*/
|
|
if (!ubi->scrub.rb_node) {
|
|
if (!ubi->used.rb_node || !ubi->free.rb_node)
|
|
/* No physical eraseblocks - no deal */
|
|
goto out_unlock;
|
|
|
|
/*
|
|
* We schedule wear-leveling only if the difference between the
|
|
* lowest erase counter of used physical eraseblocks and a high
|
|
* erase counter of free physical eraseblocks is greater than
|
|
* %UBI_WL_THRESHOLD.
|
|
*/
|
|
e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, u.rb);
|
|
e2 = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
|
|
|
|
if (!(e2->ec - e1->ec >= UBI_WL_THRESHOLD))
|
|
goto out_unlock;
|
|
dbg_wl("schedule wear-leveling");
|
|
} else
|
|
dbg_wl("schedule scrubbing");
|
|
|
|
ubi->wl_scheduled = 1;
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS);
|
|
if (!wrk) {
|
|
err = -ENOMEM;
|
|
goto out_cancel;
|
|
}
|
|
|
|
wrk->anchor = 0;
|
|
wrk->func = &wear_leveling_worker;
|
|
if (nested)
|
|
__schedule_ubi_work(ubi, wrk);
|
|
else
|
|
schedule_ubi_work(ubi, wrk);
|
|
return err;
|
|
|
|
out_cancel:
|
|
spin_lock(&ubi->wl_lock);
|
|
ubi->wl_scheduled = 0;
|
|
out_unlock:
|
|
spin_unlock(&ubi->wl_lock);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* erase_worker - physical eraseblock erase worker function.
|
|
* @ubi: UBI device description object
|
|
* @wl_wrk: the work object
|
|
* @shutdown: non-zero if the worker has to free memory and exit
|
|
* because the WL sub-system is shutting down
|
|
*
|
|
* This function erases a physical eraseblock and perform torture testing if
|
|
* needed. It also takes care about marking the physical eraseblock bad if
|
|
* needed. Returns zero in case of success and a negative error code in case of
|
|
* failure.
|
|
*/
|
|
static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
|
|
int shutdown)
|
|
{
|
|
struct ubi_wl_entry *e = wl_wrk->e;
|
|
int pnum = e->pnum;
|
|
int vol_id = wl_wrk->vol_id;
|
|
int lnum = wl_wrk->lnum;
|
|
int err, available_consumed = 0;
|
|
|
|
if (shutdown) {
|
|
dbg_wl("cancel erasure of PEB %d EC %d", pnum, e->ec);
|
|
kfree(wl_wrk);
|
|
wl_entry_destroy(ubi, e);
|
|
return 0;
|
|
}
|
|
|
|
dbg_wl("erase PEB %d EC %d LEB %d:%d",
|
|
pnum, e->ec, wl_wrk->vol_id, wl_wrk->lnum);
|
|
|
|
err = sync_erase(ubi, e, wl_wrk->torture);
|
|
if (!err) {
|
|
/* Fine, we've erased it successfully */
|
|
kfree(wl_wrk);
|
|
|
|
spin_lock(&ubi->wl_lock);
|
|
wl_tree_add(e, &ubi->free);
|
|
ubi->free_count++;
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
/*
|
|
* One more erase operation has happened, take care about
|
|
* protected physical eraseblocks.
|
|
*/
|
|
serve_prot_queue(ubi);
|
|
|
|
/* And take care about wear-leveling */
|
|
err = ensure_wear_leveling(ubi, 1);
|
|
return err;
|
|
}
|
|
|
|
ubi_err(ubi, "failed to erase PEB %d, error %d", pnum, err);
|
|
kfree(wl_wrk);
|
|
|
|
if (err == -EINTR || err == -ENOMEM || err == -EAGAIN ||
|
|
err == -EBUSY) {
|
|
int err1;
|
|
|
|
/* Re-schedule the LEB for erasure */
|
|
err1 = schedule_erase(ubi, e, vol_id, lnum, 0);
|
|
if (err1) {
|
|
err = err1;
|
|
goto out_ro;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
wl_entry_destroy(ubi, e);
|
|
if (err != -EIO)
|
|
/*
|
|
* If this is not %-EIO, we have no idea what to do. Scheduling
|
|
* this physical eraseblock for erasure again would cause
|
|
* errors again and again. Well, lets switch to R/O mode.
|
|
*/
|
|
goto out_ro;
|
|
|
|
/* It is %-EIO, the PEB went bad */
|
|
|
|
if (!ubi->bad_allowed) {
|
|
ubi_err(ubi, "bad physical eraseblock %d detected", pnum);
|
|
goto out_ro;
|
|
}
|
|
|
|
spin_lock(&ubi->volumes_lock);
|
|
if (ubi->beb_rsvd_pebs == 0) {
|
|
if (ubi->avail_pebs == 0) {
|
|
spin_unlock(&ubi->volumes_lock);
|
|
ubi_err(ubi, "no reserved/available physical eraseblocks");
|
|
goto out_ro;
|
|
}
|
|
ubi->avail_pebs -= 1;
|
|
available_consumed = 1;
|
|
}
|
|
spin_unlock(&ubi->volumes_lock);
|
|
|
|
ubi_msg(ubi, "mark PEB %d as bad", pnum);
|
|
err = ubi_io_mark_bad(ubi, pnum);
|
|
if (err)
|
|
goto out_ro;
|
|
|
|
spin_lock(&ubi->volumes_lock);
|
|
if (ubi->beb_rsvd_pebs > 0) {
|
|
if (available_consumed) {
|
|
/*
|
|
* The amount of reserved PEBs increased since we last
|
|
* checked.
|
|
*/
|
|
ubi->avail_pebs += 1;
|
|
available_consumed = 0;
|
|
}
|
|
ubi->beb_rsvd_pebs -= 1;
|
|
}
|
|
ubi->bad_peb_count += 1;
|
|
ubi->good_peb_count -= 1;
|
|
ubi_calculate_reserved(ubi);
|
|
if (available_consumed)
|
|
ubi_warn(ubi, "no PEBs in the reserved pool, used an available PEB");
|
|
else if (ubi->beb_rsvd_pebs)
|
|
ubi_msg(ubi, "%d PEBs left in the reserve",
|
|
ubi->beb_rsvd_pebs);
|
|
else
|
|
ubi_warn(ubi, "last PEB from the reserve was used");
|
|
spin_unlock(&ubi->volumes_lock);
|
|
|
|
return err;
|
|
|
|
out_ro:
|
|
if (available_consumed) {
|
|
spin_lock(&ubi->volumes_lock);
|
|
ubi->avail_pebs += 1;
|
|
spin_unlock(&ubi->volumes_lock);
|
|
}
|
|
ubi_ro_mode(ubi);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ubi_wl_put_peb - return a PEB to the wear-leveling sub-system.
|
|
* @ubi: UBI device description object
|
|
* @vol_id: the volume ID that last used this PEB
|
|
* @lnum: the last used logical eraseblock number for the PEB
|
|
* @pnum: physical eraseblock to return
|
|
* @torture: if this physical eraseblock has to be tortured
|
|
*
|
|
* This function is called to return physical eraseblock @pnum to the pool of
|
|
* free physical eraseblocks. The @torture flag has to be set if an I/O error
|
|
* occurred to this @pnum and it has to be tested. This function returns zero
|
|
* in case of success, and a negative error code in case of failure.
|
|
*/
|
|
int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
|
|
int pnum, int torture)
|
|
{
|
|
int err;
|
|
struct ubi_wl_entry *e;
|
|
|
|
dbg_wl("PEB %d", pnum);
|
|
ubi_assert(pnum >= 0);
|
|
ubi_assert(pnum < ubi->peb_count);
|
|
|
|
down_read(&ubi->fm_protect);
|
|
|
|
retry:
|
|
spin_lock(&ubi->wl_lock);
|
|
e = ubi->lookuptbl[pnum];
|
|
if (e == ubi->move_from) {
|
|
/*
|
|
* User is putting the physical eraseblock which was selected to
|
|
* be moved. It will be scheduled for erasure in the
|
|
* wear-leveling worker.
|
|
*/
|
|
dbg_wl("PEB %d is being moved, wait", pnum);
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
/* Wait for the WL worker by taking the @ubi->move_mutex */
|
|
mutex_lock(&ubi->move_mutex);
|
|
mutex_unlock(&ubi->move_mutex);
|
|
goto retry;
|
|
} else if (e == ubi->move_to) {
|
|
/*
|
|
* User is putting the physical eraseblock which was selected
|
|
* as the target the data is moved to. It may happen if the EBA
|
|
* sub-system already re-mapped the LEB in 'ubi_eba_copy_leb()'
|
|
* but the WL sub-system has not put the PEB to the "used" tree
|
|
* yet, but it is about to do this. So we just set a flag which
|
|
* will tell the WL worker that the PEB is not needed anymore
|
|
* and should be scheduled for erasure.
|
|
*/
|
|
dbg_wl("PEB %d is the target of data moving", pnum);
|
|
ubi_assert(!ubi->move_to_put);
|
|
ubi->move_to_put = 1;
|
|
spin_unlock(&ubi->wl_lock);
|
|
up_read(&ubi->fm_protect);
|
|
return 0;
|
|
} else {
|
|
if (in_wl_tree(e, &ubi->used)) {
|
|
self_check_in_wl_tree(ubi, e, &ubi->used);
|
|
rb_erase(&e->u.rb, &ubi->used);
|
|
} else if (in_wl_tree(e, &ubi->scrub)) {
|
|
self_check_in_wl_tree(ubi, e, &ubi->scrub);
|
|
rb_erase(&e->u.rb, &ubi->scrub);
|
|
} else if (in_wl_tree(e, &ubi->erroneous)) {
|
|
self_check_in_wl_tree(ubi, e, &ubi->erroneous);
|
|
rb_erase(&e->u.rb, &ubi->erroneous);
|
|
ubi->erroneous_peb_count -= 1;
|
|
ubi_assert(ubi->erroneous_peb_count >= 0);
|
|
/* Erroneous PEBs should be tortured */
|
|
torture = 1;
|
|
} else {
|
|
err = prot_queue_del(ubi, e->pnum);
|
|
if (err) {
|
|
ubi_err(ubi, "PEB %d not found", pnum);
|
|
ubi_ro_mode(ubi);
|
|
spin_unlock(&ubi->wl_lock);
|
|
up_read(&ubi->fm_protect);
|
|
return err;
|
|
}
|
|
}
|
|
}
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
err = schedule_erase(ubi, e, vol_id, lnum, torture);
|
|
if (err) {
|
|
spin_lock(&ubi->wl_lock);
|
|
wl_tree_add(e, &ubi->used);
|
|
spin_unlock(&ubi->wl_lock);
|
|
}
|
|
|
|
up_read(&ubi->fm_protect);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ubi_wl_scrub_peb - schedule a physical eraseblock for scrubbing.
|
|
* @ubi: UBI device description object
|
|
* @pnum: the physical eraseblock to schedule
|
|
*
|
|
* If a bit-flip in a physical eraseblock is detected, this physical eraseblock
|
|
* needs scrubbing. This function schedules a physical eraseblock for
|
|
* scrubbing which is done in background. This function returns zero in case of
|
|
* success and a negative error code in case of failure.
|
|
*/
|
|
int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum)
|
|
{
|
|
struct ubi_wl_entry *e;
|
|
|
|
ubi_msg(ubi, "schedule PEB %d for scrubbing", pnum);
|
|
|
|
retry:
|
|
spin_lock(&ubi->wl_lock);
|
|
e = ubi->lookuptbl[pnum];
|
|
if (e == ubi->move_from || in_wl_tree(e, &ubi->scrub) ||
|
|
in_wl_tree(e, &ubi->erroneous)) {
|
|
spin_unlock(&ubi->wl_lock);
|
|
return 0;
|
|
}
|
|
|
|
if (e == ubi->move_to) {
|
|
/*
|
|
* This physical eraseblock was used to move data to. The data
|
|
* was moved but the PEB was not yet inserted to the proper
|
|
* tree. We should just wait a little and let the WL worker
|
|
* proceed.
|
|
*/
|
|
spin_unlock(&ubi->wl_lock);
|
|
dbg_wl("the PEB %d is not in proper tree, retry", pnum);
|
|
yield();
|
|
goto retry;
|
|
}
|
|
|
|
if (in_wl_tree(e, &ubi->used)) {
|
|
self_check_in_wl_tree(ubi, e, &ubi->used);
|
|
rb_erase(&e->u.rb, &ubi->used);
|
|
} else {
|
|
int err;
|
|
|
|
err = prot_queue_del(ubi, e->pnum);
|
|
if (err) {
|
|
ubi_err(ubi, "PEB %d not found", pnum);
|
|
ubi_ro_mode(ubi);
|
|
spin_unlock(&ubi->wl_lock);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
wl_tree_add(e, &ubi->scrub);
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
/*
|
|
* Technically scrubbing is the same as wear-leveling, so it is done
|
|
* by the WL worker.
|
|
*/
|
|
return ensure_wear_leveling(ubi, 0);
|
|
}
|
|
|
|
/**
|
|
* ubi_wl_flush - flush all pending works.
|
|
* @ubi: UBI device description object
|
|
* @vol_id: the volume id to flush for
|
|
* @lnum: the logical eraseblock number to flush for
|
|
*
|
|
* This function executes all pending works for a particular volume id /
|
|
* logical eraseblock number pair. If either value is set to %UBI_ALL, then it
|
|
* acts as a wildcard for all of the corresponding volume numbers or logical
|
|
* eraseblock numbers. It returns zero in case of success and a negative error
|
|
* code in case of failure.
|
|
*/
|
|
int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum)
|
|
{
|
|
int err = 0;
|
|
int found = 1;
|
|
|
|
/*
|
|
* Erase while the pending works queue is not empty, but not more than
|
|
* the number of currently pending works.
|
|
*/
|
|
dbg_wl("flush pending work for LEB %d:%d (%d pending works)",
|
|
vol_id, lnum, ubi->works_count);
|
|
|
|
while (found) {
|
|
struct ubi_work *wrk, *tmp;
|
|
found = 0;
|
|
|
|
down_read(&ubi->work_sem);
|
|
spin_lock(&ubi->wl_lock);
|
|
list_for_each_entry_safe(wrk, tmp, &ubi->works, list) {
|
|
if ((vol_id == UBI_ALL || wrk->vol_id == vol_id) &&
|
|
(lnum == UBI_ALL || wrk->lnum == lnum)) {
|
|
list_del(&wrk->list);
|
|
ubi->works_count -= 1;
|
|
ubi_assert(ubi->works_count >= 0);
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
err = wrk->func(ubi, wrk, 0);
|
|
if (err) {
|
|
up_read(&ubi->work_sem);
|
|
return err;
|
|
}
|
|
|
|
spin_lock(&ubi->wl_lock);
|
|
found = 1;
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock(&ubi->wl_lock);
|
|
up_read(&ubi->work_sem);
|
|
}
|
|
|
|
/*
|
|
* Make sure all the works which have been done in parallel are
|
|
* finished.
|
|
*/
|
|
down_write(&ubi->work_sem);
|
|
up_write(&ubi->work_sem);
|
|
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* tree_destroy - destroy an RB-tree.
|
|
* @ubi: UBI device description object
|
|
* @root: the root of the tree to destroy
|
|
*/
|
|
static void tree_destroy(struct ubi_device *ubi, struct rb_root *root)
|
|
{
|
|
struct rb_node *rb;
|
|
struct ubi_wl_entry *e;
|
|
|
|
rb = root->rb_node;
|
|
while (rb) {
|
|
if (rb->rb_left)
|
|
rb = rb->rb_left;
|
|
else if (rb->rb_right)
|
|
rb = rb->rb_right;
|
|
else {
|
|
e = rb_entry(rb, struct ubi_wl_entry, u.rb);
|
|
|
|
rb = rb_parent(rb);
|
|
if (rb) {
|
|
if (rb->rb_left == &e->u.rb)
|
|
rb->rb_left = NULL;
|
|
else
|
|
rb->rb_right = NULL;
|
|
}
|
|
|
|
wl_entry_destroy(ubi, e);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* ubi_thread - UBI background thread.
|
|
* @u: the UBI device description object pointer
|
|
*/
|
|
int ubi_thread(void *u)
|
|
{
|
|
int failures = 0;
|
|
struct ubi_device *ubi = u;
|
|
|
|
ubi_msg(ubi, "background thread \"%s\" started, PID %d",
|
|
ubi->bgt_name, task_pid_nr(current));
|
|
|
|
set_freezable();
|
|
for (;;) {
|
|
int err;
|
|
|
|
if (kthread_should_stop())
|
|
break;
|
|
|
|
if (try_to_freeze())
|
|
continue;
|
|
|
|
spin_lock(&ubi->wl_lock);
|
|
if (list_empty(&ubi->works) || ubi->ro_mode ||
|
|
!ubi->thread_enabled || ubi_dbg_is_bgt_disabled(ubi)) {
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
spin_unlock(&ubi->wl_lock);
|
|
schedule();
|
|
continue;
|
|
}
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
err = do_work(ubi);
|
|
if (err) {
|
|
ubi_err(ubi, "%s: work failed with error code %d",
|
|
ubi->bgt_name, err);
|
|
if (failures++ > WL_MAX_FAILURES) {
|
|
/*
|
|
* Too many failures, disable the thread and
|
|
* switch to read-only mode.
|
|
*/
|
|
ubi_msg(ubi, "%s: %d consecutive failures",
|
|
ubi->bgt_name, WL_MAX_FAILURES);
|
|
ubi_ro_mode(ubi);
|
|
ubi->thread_enabled = 0;
|
|
continue;
|
|
}
|
|
} else
|
|
failures = 0;
|
|
|
|
cond_resched();
|
|
}
|
|
|
|
dbg_wl("background thread \"%s\" is killed", ubi->bgt_name);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* shutdown_work - shutdown all pending works.
|
|
* @ubi: UBI device description object
|
|
*/
|
|
static void shutdown_work(struct ubi_device *ubi)
|
|
{
|
|
#ifdef CONFIG_MTD_UBI_FASTMAP
|
|
flush_work(&ubi->fm_work);
|
|
#endif
|
|
while (!list_empty(&ubi->works)) {
|
|
struct ubi_work *wrk;
|
|
|
|
wrk = list_entry(ubi->works.next, struct ubi_work, list);
|
|
list_del(&wrk->list);
|
|
wrk->func(ubi, wrk, 1);
|
|
ubi->works_count -= 1;
|
|
ubi_assert(ubi->works_count >= 0);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* ubi_wl_init - initialize the WL sub-system using attaching information.
|
|
* @ubi: UBI device description object
|
|
* @ai: attaching information
|
|
*
|
|
* This function returns zero in case of success, and a negative error code in
|
|
* case of failure.
|
|
*/
|
|
int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
|
|
{
|
|
int err, i, reserved_pebs, found_pebs = 0;
|
|
struct rb_node *rb1, *rb2;
|
|
struct ubi_ainf_volume *av;
|
|
struct ubi_ainf_peb *aeb, *tmp;
|
|
struct ubi_wl_entry *e;
|
|
|
|
ubi->used = ubi->erroneous = ubi->free = ubi->scrub = RB_ROOT;
|
|
spin_lock_init(&ubi->wl_lock);
|
|
mutex_init(&ubi->move_mutex);
|
|
init_rwsem(&ubi->work_sem);
|
|
ubi->max_ec = ai->max_ec;
|
|
INIT_LIST_HEAD(&ubi->works);
|
|
|
|
sprintf(ubi->bgt_name, UBI_BGT_NAME_PATTERN, ubi->ubi_num);
|
|
|
|
err = -ENOMEM;
|
|
ubi->lookuptbl = kzalloc(ubi->peb_count * sizeof(void *), GFP_KERNEL);
|
|
if (!ubi->lookuptbl)
|
|
return err;
|
|
|
|
for (i = 0; i < UBI_PROT_QUEUE_LEN; i++)
|
|
INIT_LIST_HEAD(&ubi->pq[i]);
|
|
ubi->pq_head = 0;
|
|
|
|
list_for_each_entry_safe(aeb, tmp, &ai->erase, u.list) {
|
|
cond_resched();
|
|
|
|
e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
|
|
if (!e)
|
|
goto out_free;
|
|
|
|
e->pnum = aeb->pnum;
|
|
e->ec = aeb->ec;
|
|
ubi->lookuptbl[e->pnum] = e;
|
|
if (schedule_erase(ubi, e, aeb->vol_id, aeb->lnum, 0)) {
|
|
wl_entry_destroy(ubi, e);
|
|
goto out_free;
|
|
}
|
|
|
|
found_pebs++;
|
|
}
|
|
|
|
ubi->free_count = 0;
|
|
list_for_each_entry(aeb, &ai->free, u.list) {
|
|
cond_resched();
|
|
|
|
e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
|
|
if (!e)
|
|
goto out_free;
|
|
|
|
e->pnum = aeb->pnum;
|
|
e->ec = aeb->ec;
|
|
ubi_assert(e->ec >= 0);
|
|
|
|
wl_tree_add(e, &ubi->free);
|
|
ubi->free_count++;
|
|
|
|
ubi->lookuptbl[e->pnum] = e;
|
|
|
|
found_pebs++;
|
|
}
|
|
|
|
ubi_rb_for_each_entry(rb1, av, &ai->volumes, rb) {
|
|
ubi_rb_for_each_entry(rb2, aeb, &av->root, u.rb) {
|
|
cond_resched();
|
|
|
|
e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
|
|
if (!e)
|
|
goto out_free;
|
|
|
|
e->pnum = aeb->pnum;
|
|
e->ec = aeb->ec;
|
|
ubi->lookuptbl[e->pnum] = e;
|
|
|
|
if (!aeb->scrub) {
|
|
dbg_wl("add PEB %d EC %d to the used tree",
|
|
e->pnum, e->ec);
|
|
wl_tree_add(e, &ubi->used);
|
|
} else {
|
|
dbg_wl("add PEB %d EC %d to the scrub tree",
|
|
e->pnum, e->ec);
|
|
wl_tree_add(e, &ubi->scrub);
|
|
}
|
|
|
|
found_pebs++;
|
|
}
|
|
}
|
|
|
|
dbg_wl("found %i PEBs", found_pebs);
|
|
|
|
if (ubi->fm) {
|
|
ubi_assert(ubi->good_peb_count ==
|
|
found_pebs + ubi->fm->used_blocks);
|
|
|
|
for (i = 0; i < ubi->fm->used_blocks; i++) {
|
|
e = ubi->fm->e[i];
|
|
ubi->lookuptbl[e->pnum] = e;
|
|
}
|
|
}
|
|
else
|
|
ubi_assert(ubi->good_peb_count == found_pebs);
|
|
|
|
reserved_pebs = WL_RESERVED_PEBS;
|
|
ubi_fastmap_init(ubi, &reserved_pebs);
|
|
|
|
if (ubi->avail_pebs < reserved_pebs) {
|
|
ubi_err(ubi, "no enough physical eraseblocks (%d, need %d)",
|
|
ubi->avail_pebs, reserved_pebs);
|
|
if (ubi->corr_peb_count)
|
|
ubi_err(ubi, "%d PEBs are corrupted and not used",
|
|
ubi->corr_peb_count);
|
|
goto out_free;
|
|
}
|
|
ubi->avail_pebs -= reserved_pebs;
|
|
ubi->rsvd_pebs += reserved_pebs;
|
|
|
|
/* Schedule wear-leveling if needed */
|
|
err = ensure_wear_leveling(ubi, 0);
|
|
if (err)
|
|
goto out_free;
|
|
|
|
return 0;
|
|
|
|
out_free:
|
|
shutdown_work(ubi);
|
|
tree_destroy(ubi, &ubi->used);
|
|
tree_destroy(ubi, &ubi->free);
|
|
tree_destroy(ubi, &ubi->scrub);
|
|
kfree(ubi->lookuptbl);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* protection_queue_destroy - destroy the protection queue.
|
|
* @ubi: UBI device description object
|
|
*/
|
|
static void protection_queue_destroy(struct ubi_device *ubi)
|
|
{
|
|
int i;
|
|
struct ubi_wl_entry *e, *tmp;
|
|
|
|
for (i = 0; i < UBI_PROT_QUEUE_LEN; ++i) {
|
|
list_for_each_entry_safe(e, tmp, &ubi->pq[i], u.list) {
|
|
list_del(&e->u.list);
|
|
wl_entry_destroy(ubi, e);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* ubi_wl_close - close the wear-leveling sub-system.
|
|
* @ubi: UBI device description object
|
|
*/
|
|
void ubi_wl_close(struct ubi_device *ubi)
|
|
{
|
|
dbg_wl("close the WL sub-system");
|
|
ubi_fastmap_close(ubi);
|
|
shutdown_work(ubi);
|
|
protection_queue_destroy(ubi);
|
|
tree_destroy(ubi, &ubi->used);
|
|
tree_destroy(ubi, &ubi->erroneous);
|
|
tree_destroy(ubi, &ubi->free);
|
|
tree_destroy(ubi, &ubi->scrub);
|
|
kfree(ubi->lookuptbl);
|
|
}
|
|
|
|
/**
|
|
* self_check_ec - make sure that the erase counter of a PEB is correct.
|
|
* @ubi: UBI device description object
|
|
* @pnum: the physical eraseblock number to check
|
|
* @ec: the erase counter to check
|
|
*
|
|
* This function returns zero if the erase counter of physical eraseblock @pnum
|
|
* is equivalent to @ec, and a negative error code if not or if an error
|
|
* occurred.
|
|
*/
|
|
static int self_check_ec(struct ubi_device *ubi, int pnum, int ec)
|
|
{
|
|
int err;
|
|
long long read_ec;
|
|
struct ubi_ec_hdr *ec_hdr;
|
|
|
|
if (!ubi_dbg_chk_gen(ubi))
|
|
return 0;
|
|
|
|
ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
|
|
if (!ec_hdr)
|
|
return -ENOMEM;
|
|
|
|
err = ubi_io_read_ec_hdr(ubi, pnum, ec_hdr, 0);
|
|
if (err && err != UBI_IO_BITFLIPS) {
|
|
/* The header does not have to exist */
|
|
err = 0;
|
|
goto out_free;
|
|
}
|
|
|
|
read_ec = be64_to_cpu(ec_hdr->ec);
|
|
if (ec != read_ec && read_ec - ec > 1) {
|
|
ubi_err(ubi, "self-check failed for PEB %d", pnum);
|
|
ubi_err(ubi, "read EC is %lld, should be %d", read_ec, ec);
|
|
dump_stack();
|
|
err = 1;
|
|
} else
|
|
err = 0;
|
|
|
|
out_free:
|
|
kfree(ec_hdr);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* self_check_in_wl_tree - check that wear-leveling entry is in WL RB-tree.
|
|
* @ubi: UBI device description object
|
|
* @e: the wear-leveling entry to check
|
|
* @root: the root of the tree
|
|
*
|
|
* This function returns zero if @e is in the @root RB-tree and %-EINVAL if it
|
|
* is not.
|
|
*/
|
|
static int self_check_in_wl_tree(const struct ubi_device *ubi,
|
|
struct ubi_wl_entry *e, struct rb_root *root)
|
|
{
|
|
if (!ubi_dbg_chk_gen(ubi))
|
|
return 0;
|
|
|
|
if (in_wl_tree(e, root))
|
|
return 0;
|
|
|
|
ubi_err(ubi, "self-check failed for PEB %d, EC %d, RB-tree %p ",
|
|
e->pnum, e->ec, root);
|
|
dump_stack();
|
|
return -EINVAL;
|
|
}
|
|
|
|
/**
|
|
* self_check_in_pq - check if wear-leveling entry is in the protection
|
|
* queue.
|
|
* @ubi: UBI device description object
|
|
* @e: the wear-leveling entry to check
|
|
*
|
|
* This function returns zero if @e is in @ubi->pq and %-EINVAL if it is not.
|
|
*/
|
|
static int self_check_in_pq(const struct ubi_device *ubi,
|
|
struct ubi_wl_entry *e)
|
|
{
|
|
struct ubi_wl_entry *p;
|
|
int i;
|
|
|
|
if (!ubi_dbg_chk_gen(ubi))
|
|
return 0;
|
|
|
|
for (i = 0; i < UBI_PROT_QUEUE_LEN; ++i)
|
|
list_for_each_entry(p, &ubi->pq[i], u.list)
|
|
if (p == e)
|
|
return 0;
|
|
|
|
ubi_err(ubi, "self-check failed for PEB %d, EC %d, Protect queue",
|
|
e->pnum, e->ec);
|
|
dump_stack();
|
|
return -EINVAL;
|
|
}
|
|
#ifndef CONFIG_MTD_UBI_FASTMAP
|
|
static struct ubi_wl_entry *get_peb_for_wl(struct ubi_device *ubi)
|
|
{
|
|
struct ubi_wl_entry *e;
|
|
|
|
e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
|
|
self_check_in_wl_tree(ubi, e, &ubi->free);
|
|
ubi->free_count--;
|
|
ubi_assert(ubi->free_count >= 0);
|
|
rb_erase(&e->u.rb, &ubi->free);
|
|
|
|
return e;
|
|
}
|
|
|
|
/**
|
|
* produce_free_peb - produce a free physical eraseblock.
|
|
* @ubi: UBI device description object
|
|
*
|
|
* This function tries to make a free PEB by means of synchronous execution of
|
|
* pending works. This may be needed if, for example the background thread is
|
|
* disabled. Returns zero in case of success and a negative error code in case
|
|
* of failure.
|
|
*/
|
|
static int produce_free_peb(struct ubi_device *ubi)
|
|
{
|
|
int err;
|
|
|
|
while (!ubi->free.rb_node && ubi->works_count) {
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
dbg_wl("do one work synchronously");
|
|
err = do_work(ubi);
|
|
|
|
spin_lock(&ubi->wl_lock);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* 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 err;
|
|
struct ubi_wl_entry *e;
|
|
|
|
retry:
|
|
down_read(&ubi->fm_eba_sem);
|
|
spin_lock(&ubi->wl_lock);
|
|
if (!ubi->free.rb_node) {
|
|
if (ubi->works_count == 0) {
|
|
ubi_err(ubi, "no free eraseblocks");
|
|
ubi_assert(list_empty(&ubi->works));
|
|
spin_unlock(&ubi->wl_lock);
|
|
return -ENOSPC;
|
|
}
|
|
|
|
err = produce_free_peb(ubi);
|
|
if (err < 0) {
|
|
spin_unlock(&ubi->wl_lock);
|
|
return err;
|
|
}
|
|
spin_unlock(&ubi->wl_lock);
|
|
up_read(&ubi->fm_eba_sem);
|
|
goto retry;
|
|
|
|
}
|
|
e = wl_get_wle(ubi);
|
|
prot_queue_add(ubi, e);
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
err = ubi_self_check_all_ff(ubi, e->pnum, ubi->vid_hdr_aloffset,
|
|
ubi->peb_size - ubi->vid_hdr_aloffset);
|
|
if (err) {
|
|
ubi_err(ubi, "new PEB %d does not contain all 0xFF bytes", e->pnum);
|
|
return err;
|
|
}
|
|
|
|
return e->pnum;
|
|
}
|
|
#else
|
|
#include "fastmap-wl.c"
|
|
#endif
|