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https://github.com/brain-hackers/u-boot-brain
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![Joe Hershberger](/assets/img/avatar_default.png)
The unwind code was not reversing operations correctly and was causing a hang on any error condition. Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
1677 lines
44 KiB
C
1677 lines
44 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 unit.
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*
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* This unit is responsible for wear-leveling. It works in terms of physical
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* eraseblocks and erase counters and knows nothing about logical eraseblocks,
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* volumes, etc. From this unit's perspective all physical eraseblocks are of
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* two types - used and free. Used physical eraseblocks are those that were
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* "get" by the 'ubi_wl_get_peb()' function, and free physical eraseblocks are
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* 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 unit 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 unit.
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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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* The 'ubi_wl_get_peb()' function accepts data type hints which help to pick
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* an "optimal" physical eraseblock. For example, when it is known that the
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* physical eraseblock will be "put" soon because it contains short-term data,
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* the WL unit may pick a free physical eraseblock with low erase counter, and
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* so forth.
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*
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* If the WL unit fails to erase a physical eraseblock, it marks it as bad.
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*
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* This unit is also responsible for scrubbing. If a bit-flip is detected in a
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* physical eraseblock, it has to be moved. Technically this is the same as
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* moving it for wear-leveling reasons.
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*
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* As it was said, for the UBI unit all physical eraseblocks are either "free"
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* or "used". Free eraseblock are kept in the @wl->free RB-tree, while used
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* eraseblocks are kept in a set of different RB-trees: @wl->used,
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* @wl->prot.pnum, @wl->prot.aec, and @wl->scrub.
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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 unit and make it more scalable.
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*
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* At the moment this unit does not utilize the sequence number, which was
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* introduced relatively recently. But it would be wise to do this because the
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* 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 unit.
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*
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* FIXME: looks too complex, should be simplified (later).
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*/
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#ifdef UBI_LINUX
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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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#endif
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#include <ubi_uboot.h>
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#include "ubi.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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* How many erase cycles are short term, unknown, and long term physical
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* eraseblocks protected.
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*/
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#define ST_PROTECTION 16
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#define U_PROTECTION 10
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#define LT_PROTECTION 4
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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 unit starts moving data from used physical eraseblocks with
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* low erase counter to free physical eraseblocks with high 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 unit 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 unit does
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* not pick eraseblocks with erase counter greater then 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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/**
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* struct ubi_wl_prot_entry - PEB protection entry.
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* @rb_pnum: link in the @wl->prot.pnum RB-tree
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* @rb_aec: link in the @wl->prot.aec RB-tree
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* @abs_ec: the absolute erase counter value when the protection ends
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* @e: the wear-leveling entry of the physical eraseblock under protection
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*
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* When the WL unit returns a physical eraseblock, the physical eraseblock is
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* protected from being moved for some "time". For this reason, the physical
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* eraseblock is not directly moved from the @wl->free tree to the @wl->used
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* tree. There is one more tree in between where this physical eraseblock is
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* temporarily stored (@wl->prot).
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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; this is
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* especially important in case of "short term" physical eraseblocks.
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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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* absolute erase counter (@wl->abs_ec). When it reaches certain value, the
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* physical eraseblocks are moved from the protection trees (@wl->prot.*) to
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* the @wl->used tree.
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*
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* Protected physical eraseblocks are searched by physical eraseblock number
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* (when they are put) and by the absolute erase counter (to check if it is
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* time to move them to the @wl->used tree). So there are actually 2 RB-trees
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* storing the protected physical eraseblocks: @wl->prot.pnum and
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* @wl->prot.aec. They are referred to as the "protection" trees. The
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* first one is indexed by the physical eraseblock number. The second one is
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* indexed by the absolute erase counter. Both trees store
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* &struct ubi_wl_prot_entry objects.
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*
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* Each physical eraseblock has 2 main states: free and used. The former state
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* corresponds to the @wl->free tree. The latter state is split up on several
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* sub-states:
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* o the WL movement is allowed (@wl->used tree);
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* o the WL movement is temporarily prohibited (@wl->prot.pnum and
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* @wl->prot.aec trees);
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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 trees.
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*/
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struct ubi_wl_prot_entry {
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struct rb_node rb_pnum;
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struct rb_node rb_aec;
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unsigned long long abs_ec;
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struct ubi_wl_entry *e;
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};
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/**
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* struct ubi_work - UBI work description data structure.
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* @list: a link in the list of pending works
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* @func: worker function
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* @priv: private data of the worker function
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*
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* @e: 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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* The @func pointer points to the worker function. If the @cancel argument is
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* not zero, the worker has to free the resources and exit immediately. The
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* worker has to return 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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struct ubi_work {
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struct list_head list;
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int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int cancel);
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/* The below fields are only relevant to erasure works */
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struct ubi_wl_entry *e;
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int torture;
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};
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#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
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static int paranoid_check_ec(struct ubi_device *ubi, int pnum, int ec);
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static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e,
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struct rb_root *root);
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#else
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#define paranoid_check_ec(ubi, pnum, ec) 0
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#define paranoid_check_in_wl_tree(e, root)
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#endif
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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, 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->rb, parent, p);
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rb_insert_color(&e->rb, root);
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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("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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* 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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spin_lock(&ubi->wl_lock);
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while (!ubi->free.rb_node) {
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spin_unlock(&ubi->wl_lock);
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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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spin_lock(&ubi->wl_lock);
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}
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spin_unlock(&ubi->wl_lock);
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return 0;
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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, 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_tree_add - add physical eraseblock to protection trees.
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* @ubi: UBI device description object
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* @e: the physical eraseblock to add
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* @pe: protection entry object to use
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* @abs_ec: absolute erase counter value when this physical eraseblock has
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* to be removed from the protection trees.
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*
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* @wl->lock has to be locked.
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*/
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static void prot_tree_add(struct ubi_device *ubi, struct ubi_wl_entry *e,
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struct ubi_wl_prot_entry *pe, int abs_ec)
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{
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struct rb_node **p, *parent = NULL;
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struct ubi_wl_prot_entry *pe1;
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pe->e = e;
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pe->abs_ec = ubi->abs_ec + abs_ec;
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p = &ubi->prot.pnum.rb_node;
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while (*p) {
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parent = *p;
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pe1 = rb_entry(parent, struct ubi_wl_prot_entry, rb_pnum);
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if (e->pnum < pe1->e->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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rb_link_node(&pe->rb_pnum, parent, p);
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rb_insert_color(&pe->rb_pnum, &ubi->prot.pnum);
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p = &ubi->prot.aec.rb_node;
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parent = NULL;
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while (*p) {
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parent = *p;
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pe1 = rb_entry(parent, struct ubi_wl_prot_entry, rb_aec);
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if (pe->abs_ec < pe1->abs_ec)
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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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rb_link_node(&pe->rb_aec, parent, p);
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rb_insert_color(&pe->rb_aec, &ubi->prot.aec);
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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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* @root: the RB-tree where to look for
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* @max: highest possible 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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* @max and less then @max.
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*/
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static struct ubi_wl_entry *find_wl_entry(struct rb_root *root, int max)
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{
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struct rb_node *p;
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struct ubi_wl_entry *e;
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e = rb_entry(rb_first(root), struct ubi_wl_entry, rb);
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max += e->ec;
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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, 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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e = e1;
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}
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}
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return e;
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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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* @dtype: type of data which will be stored in this physical eraseblock
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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. Might sleep.
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*/
|
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int ubi_wl_get_peb(struct ubi_device *ubi, int dtype)
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{
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int err, protect, medium_ec;
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struct ubi_wl_entry *e, *first, *last;
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struct ubi_wl_prot_entry *pe;
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ubi_assert(dtype == UBI_LONGTERM || dtype == UBI_SHORTTERM ||
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dtype == UBI_UNKNOWN);
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pe = kmalloc(sizeof(struct ubi_wl_prot_entry), GFP_NOFS);
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if (!pe)
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return -ENOMEM;
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retry:
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spin_lock(&ubi->wl_lock);
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if (!ubi->free.rb_node) {
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if (ubi->works_count == 0) {
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ubi_assert(list_empty(&ubi->works));
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ubi_err("no free eraseblocks");
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spin_unlock(&ubi->wl_lock);
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kfree(pe);
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return -ENOSPC;
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}
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spin_unlock(&ubi->wl_lock);
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err = produce_free_peb(ubi);
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if (err < 0) {
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kfree(pe);
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return err;
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}
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goto retry;
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}
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switch (dtype) {
|
|
case UBI_LONGTERM:
|
|
/*
|
|
* For long term data we pick a physical eraseblock
|
|
* with high erase counter. But the highest erase
|
|
* counter we can pick is bounded by the the lowest
|
|
* erase counter plus %WL_FREE_MAX_DIFF.
|
|
*/
|
|
e = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
|
|
protect = LT_PROTECTION;
|
|
break;
|
|
case UBI_UNKNOWN:
|
|
/*
|
|
* For unknown data we pick a physical eraseblock with
|
|
* medium erase counter. But we by no means can pick a
|
|
* physical eraseblock with erase counter greater or
|
|
* equivalent than the lowest erase counter plus
|
|
* %WL_FREE_MAX_DIFF.
|
|
*/
|
|
first = rb_entry(rb_first(&ubi->free),
|
|
struct ubi_wl_entry, rb);
|
|
last = rb_entry(rb_last(&ubi->free),
|
|
struct ubi_wl_entry, rb);
|
|
|
|
if (last->ec - first->ec < WL_FREE_MAX_DIFF)
|
|
e = rb_entry(ubi->free.rb_node,
|
|
struct ubi_wl_entry, rb);
|
|
else {
|
|
medium_ec = (first->ec + WL_FREE_MAX_DIFF)/2;
|
|
e = find_wl_entry(&ubi->free, medium_ec);
|
|
}
|
|
protect = U_PROTECTION;
|
|
break;
|
|
case UBI_SHORTTERM:
|
|
/*
|
|
* For short term data we pick a physical eraseblock
|
|
* with the lowest erase counter as we expect it will
|
|
* be erased soon.
|
|
*/
|
|
e = rb_entry(rb_first(&ubi->free),
|
|
struct ubi_wl_entry, rb);
|
|
protect = ST_PROTECTION;
|
|
break;
|
|
default:
|
|
protect = 0;
|
|
e = NULL;
|
|
BUG();
|
|
}
|
|
|
|
/*
|
|
* Move the physical eraseblock to the protection trees where it will
|
|
* be protected from being moved for some time.
|
|
*/
|
|
paranoid_check_in_wl_tree(e, &ubi->free);
|
|
rb_erase(&e->rb, &ubi->free);
|
|
prot_tree_add(ubi, e, pe, protect);
|
|
|
|
dbg_wl("PEB %d EC %d, protection %d", e->pnum, e->ec, protect);
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
return e->pnum;
|
|
}
|
|
|
|
/**
|
|
* prot_tree_del - remove a physical eraseblock from the protection trees
|
|
* @ubi: UBI device description object
|
|
* @pnum: the physical eraseblock to remove
|
|
*
|
|
* This function returns PEB @pnum from the protection trees and returns zero
|
|
* in case of success and %-ENODEV if the PEB was not found in the protection
|
|
* trees.
|
|
*/
|
|
static int prot_tree_del(struct ubi_device *ubi, int pnum)
|
|
{
|
|
struct rb_node *p;
|
|
struct ubi_wl_prot_entry *pe = NULL;
|
|
|
|
p = ubi->prot.pnum.rb_node;
|
|
while (p) {
|
|
|
|
pe = rb_entry(p, struct ubi_wl_prot_entry, rb_pnum);
|
|
|
|
if (pnum == pe->e->pnum)
|
|
goto found;
|
|
|
|
if (pnum < pe->e->pnum)
|
|
p = p->rb_left;
|
|
else
|
|
p = p->rb_right;
|
|
}
|
|
|
|
return -ENODEV;
|
|
|
|
found:
|
|
ubi_assert(pe->e->pnum == pnum);
|
|
rb_erase(&pe->rb_aec, &ubi->prot.aec);
|
|
rb_erase(&pe->rb_pnum, &ubi->prot.pnum);
|
|
kfree(pe);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* sync_erase - synchronously erase a physical eraseblock.
|
|
* @ubi: UBI device description object
|
|
* @e: the the physical eraseblock to erase
|
|
* @torture: if the physical eraseblock has to be tortured
|
|
*
|
|
* This function returns zero in case of success and a negative error code in
|
|
* case of failure.
|
|
*/
|
|
static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e, int torture)
|
|
{
|
|
int err;
|
|
struct ubi_ec_hdr *ec_hdr;
|
|
unsigned long long ec = e->ec;
|
|
|
|
dbg_wl("erase PEB %d, old EC %llu", e->pnum, ec);
|
|
|
|
err = paranoid_check_ec(ubi, e->pnum, e->ec);
|
|
if (err > 0)
|
|
return -EINVAL;
|
|
|
|
ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
|
|
if (!ec_hdr)
|
|
return -ENOMEM;
|
|
|
|
err = ubi_io_sync_erase(ubi, e->pnum, torture);
|
|
if (err < 0)
|
|
goto out_free;
|
|
|
|
ec += err;
|
|
if (ec > UBI_MAX_ERASECOUNTER) {
|
|
/*
|
|
* Erase counter overflow. Upgrade UBI and use 64-bit
|
|
* erase counters internally.
|
|
*/
|
|
ubi_err("erase counter overflow at PEB %d, EC %llu",
|
|
e->pnum, ec);
|
|
err = -EINVAL;
|
|
goto out_free;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* check_protection_over - check if it is time to stop protecting some
|
|
* physical eraseblocks.
|
|
* @ubi: UBI device description object
|
|
*
|
|
* This function is called after each erase operation, when the absolute erase
|
|
* counter is incremented, to check if some physical eraseblock have not to be
|
|
* protected any longer. These physical eraseblocks are moved from the
|
|
* protection trees to the used tree.
|
|
*/
|
|
static void check_protection_over(struct ubi_device *ubi)
|
|
{
|
|
struct ubi_wl_prot_entry *pe;
|
|
|
|
/*
|
|
* There may be several protected physical eraseblock to remove,
|
|
* process them all.
|
|
*/
|
|
while (1) {
|
|
spin_lock(&ubi->wl_lock);
|
|
if (!ubi->prot.aec.rb_node) {
|
|
spin_unlock(&ubi->wl_lock);
|
|
break;
|
|
}
|
|
|
|
pe = rb_entry(rb_first(&ubi->prot.aec),
|
|
struct ubi_wl_prot_entry, rb_aec);
|
|
|
|
if (pe->abs_ec > ubi->abs_ec) {
|
|
spin_unlock(&ubi->wl_lock);
|
|
break;
|
|
}
|
|
|
|
dbg_wl("PEB %d protection over, abs_ec %llu, PEB abs_ec %llu",
|
|
pe->e->pnum, ubi->abs_ec, pe->abs_ec);
|
|
rb_erase(&pe->rb_aec, &ubi->prot.aec);
|
|
rb_erase(&pe->rb_pnum, &ubi->prot.pnum);
|
|
wl_tree_add(pe->e, &ubi->used);
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
kfree(pe);
|
|
cond_resched();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* schedule_ubi_work - schedule a work.
|
|
* @ubi: UBI device description object
|
|
* @wrk: the work to schedule
|
|
*
|
|
* This function enqueues 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)
|
|
{
|
|
spin_lock(&ubi->wl_lock);
|
|
list_add_tail(&wrk->list, &ubi->works);
|
|
ubi_assert(ubi->works_count >= 0);
|
|
ubi->works_count += 1;
|
|
|
|
/*
|
|
* U-Boot special: We have no bgt_thread in U-Boot!
|
|
* So just call do_work() here directly.
|
|
*/
|
|
do_work(ubi);
|
|
|
|
spin_unlock(&ubi->wl_lock);
|
|
}
|
|
|
|
static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
|
|
int cancel);
|
|
|
|
/**
|
|
* schedule_erase - schedule an erase work.
|
|
* @ubi: UBI device description object
|
|
* @e: the WL entry of the physical eraseblock to erase
|
|
* @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 torture)
|
|
{
|
|
struct ubi_work *wl_wrk;
|
|
|
|
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->torture = torture;
|
|
|
|
schedule_ubi_work(ubi, wl_wrk);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* wear_leveling_worker - wear-leveling worker function.
|
|
* @ubi: UBI device description object
|
|
* @wrk: the work object
|
|
* @cancel: non-zero if the worker has to free memory and exit
|
|
*
|
|
* 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 cancel)
|
|
{
|
|
int err, put = 0, scrubbing = 0, protect = 0;
|
|
struct ubi_wl_prot_entry *uninitialized_var(pe);
|
|
struct ubi_wl_entry *e1, *e2;
|
|
struct ubi_vid_hdr *vid_hdr;
|
|
|
|
kfree(wrk);
|
|
|
|
if (cancel)
|
|
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;
|
|
}
|
|
|
|
if (!ubi->scrub.rb_node) {
|
|
/*
|
|
* 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, rb);
|
|
e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
|
|
|
|
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);
|
|
goto out_cancel;
|
|
}
|
|
paranoid_check_in_wl_tree(e1, &ubi->used);
|
|
rb_erase(&e1->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, rb);
|
|
e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
|
|
paranoid_check_in_wl_tree(e1, &ubi->scrub);
|
|
rb_erase(&e1->rb, &ubi->scrub);
|
|
dbg_wl("scrub PEB %d to PEB %d", e1->pnum, e2->pnum);
|
|
}
|
|
|
|
paranoid_check_in_wl_tree(e2, &ubi->free);
|
|
rb_erase(&e2->rb, &ubi->free);
|
|
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_PEB_FREE) {
|
|
/*
|
|
* 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 did not have
|
|
* chance to write it down because it was preempted.
|
|
* Just re-schedule the work, so that next time it will
|
|
* likely have the VID header in place.
|
|
*/
|
|
dbg_wl("PEB %d has no VID header", e1->pnum);
|
|
goto out_not_moved;
|
|
}
|
|
|
|
ubi_err("error %d while reading VID header from PEB %d",
|
|
err, e1->pnum);
|
|
if (err > 0)
|
|
err = -EIO;
|
|
goto out_error;
|
|
}
|
|
|
|
err = ubi_eba_copy_leb(ubi, e1->pnum, e2->pnum, vid_hdr);
|
|
if (err) {
|
|
|
|
if (err < 0)
|
|
goto out_error;
|
|
if (err == 1)
|
|
goto out_not_moved;
|
|
|
|
/*
|
|
* For some reason the LEB was not moved - it might be because
|
|
* the volume is being deleted. We should prevent this PEB from
|
|
* being selected for wear-levelling movement for some "time",
|
|
* so put it to the protection tree.
|
|
*/
|
|
|
|
dbg_wl("cancelled moving PEB %d", e1->pnum);
|
|
pe = kmalloc(sizeof(struct ubi_wl_prot_entry), GFP_NOFS);
|
|
if (!pe) {
|
|
err = -ENOMEM;
|
|
goto out_error;
|
|
}
|
|
|
|
protect = 1;
|
|
}
|
|
|
|
ubi_free_vid_hdr(ubi, vid_hdr);
|
|
spin_lock(&ubi->wl_lock);
|
|
if (protect)
|
|
prot_tree_add(ubi, e1, pe, protect);
|
|
if (!ubi->move_to_put)
|
|
wl_tree_add(e2, &ubi->used);
|
|
else
|
|
put = 1;
|
|
ubi->move_from = ubi->move_to = NULL;
|
|
ubi->move_to_put = ubi->wl_scheduled = 0;
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
if (put) {
|
|
/*
|
|
* Well, the target PEB was put meanwhile, schedule it for
|
|
* erasure.
|
|
*/
|
|
dbg_wl("PEB %d was put meanwhile, erase", e2->pnum);
|
|
err = schedule_erase(ubi, e2, 0);
|
|
if (err)
|
|
goto out_error;
|
|
}
|
|
|
|
if (!protect) {
|
|
err = schedule_erase(ubi, e1, 0);
|
|
if (err)
|
|
goto out_error;
|
|
}
|
|
|
|
|
|
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
|
|
* be changed, schedule it for erasure.
|
|
*/
|
|
out_not_moved:
|
|
ubi_free_vid_hdr(ubi, vid_hdr);
|
|
spin_lock(&ubi->wl_lock);
|
|
if (scrubbing)
|
|
wl_tree_add(e1, &ubi->scrub);
|
|
else
|
|
wl_tree_add(e1, &ubi->used);
|
|
ubi->move_from = ubi->move_to = NULL;
|
|
ubi->move_to_put = ubi->wl_scheduled = 0;
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
err = schedule_erase(ubi, e2, 0);
|
|
if (err)
|
|
goto out_error;
|
|
|
|
mutex_unlock(&ubi->move_mutex);
|
|
return 0;
|
|
|
|
out_error:
|
|
ubi_err("error %d while moving PEB %d to PEB %d",
|
|
err, e1->pnum, e2->pnum);
|
|
|
|
ubi_free_vid_hdr(ubi, vid_hdr);
|
|
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);
|
|
|
|
kmem_cache_free(ubi_wl_entry_slab, e1);
|
|
kmem_cache_free(ubi_wl_entry_slab, e2);
|
|
ubi_ro_mode(ubi);
|
|
|
|
mutex_unlock(&ubi->move_mutex);
|
|
return err;
|
|
|
|
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
|
|
*
|
|
* 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 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 then
|
|
* %UBI_WL_THRESHOLD.
|
|
*/
|
|
e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, rb);
|
|
e2 = find_wl_entry(&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->func = &wear_leveling_worker;
|
|
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
|
|
* @cancel: non-zero if the worker has to free memory and exit
|
|
*
|
|
* 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 cancel)
|
|
{
|
|
struct ubi_wl_entry *e = wl_wrk->e;
|
|
int pnum = e->pnum, err, need;
|
|
|
|
if (cancel) {
|
|
dbg_wl("cancel erasure of PEB %d EC %d", pnum, e->ec);
|
|
kfree(wl_wrk);
|
|
kmem_cache_free(ubi_wl_entry_slab, e);
|
|
return 0;
|
|
}
|
|
|
|
dbg_wl("erase PEB %d EC %d", pnum, e->ec);
|
|
|
|
err = sync_erase(ubi, e, wl_wrk->torture);
|
|
if (!err) {
|
|
/* Fine, we've erased it successfully */
|
|
kfree(wl_wrk);
|
|
|
|
spin_lock(&ubi->wl_lock);
|
|
ubi->abs_ec += 1;
|
|
wl_tree_add(e, &ubi->free);
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
/*
|
|
* One more erase operation has happened, take care about protected
|
|
* physical eraseblocks.
|
|
*/
|
|
check_protection_over(ubi);
|
|
|
|
/* And take care about wear-leveling */
|
|
err = ensure_wear_leveling(ubi);
|
|
return err;
|
|
}
|
|
|
|
ubi_err("failed to erase PEB %d, error %d", pnum, err);
|
|
kfree(wl_wrk);
|
|
kmem_cache_free(ubi_wl_entry_slab, e);
|
|
|
|
if (err == -EINTR || err == -ENOMEM || err == -EAGAIN ||
|
|
err == -EBUSY) {
|
|
int err1;
|
|
|
|
/* Re-schedule the LEB for erasure */
|
|
err1 = schedule_erase(ubi, e, 0);
|
|
if (err1) {
|
|
err = err1;
|
|
goto out_ro;
|
|
}
|
|
return err;
|
|
} else 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 RO mode.
|
|
*/
|
|
goto out_ro;
|
|
}
|
|
|
|
/* It is %-EIO, the PEB went bad */
|
|
|
|
if (!ubi->bad_allowed) {
|
|
ubi_err("bad physical eraseblock %d detected", pnum);
|
|
goto out_ro;
|
|
}
|
|
|
|
spin_lock(&ubi->volumes_lock);
|
|
need = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs + 1;
|
|
if (need > 0) {
|
|
need = ubi->avail_pebs >= need ? need : ubi->avail_pebs;
|
|
ubi->avail_pebs -= need;
|
|
ubi->rsvd_pebs += need;
|
|
ubi->beb_rsvd_pebs += need;
|
|
if (need > 0)
|
|
ubi_msg("reserve more %d PEBs", need);
|
|
}
|
|
|
|
if (ubi->beb_rsvd_pebs == 0) {
|
|
spin_unlock(&ubi->volumes_lock);
|
|
ubi_err("no reserved physical eraseblocks");
|
|
goto out_ro;
|
|
}
|
|
|
|
spin_unlock(&ubi->volumes_lock);
|
|
ubi_msg("mark PEB %d as bad", pnum);
|
|
|
|
err = ubi_io_mark_bad(ubi, pnum);
|
|
if (err)
|
|
goto out_ro;
|
|
|
|
spin_lock(&ubi->volumes_lock);
|
|
ubi->beb_rsvd_pebs -= 1;
|
|
ubi->bad_peb_count += 1;
|
|
ubi->good_peb_count -= 1;
|
|
ubi_calculate_reserved(ubi);
|
|
if (ubi->beb_rsvd_pebs == 0)
|
|
ubi_warn("last PEB from the reserved pool was used");
|
|
spin_unlock(&ubi->volumes_lock);
|
|
|
|
return err;
|
|
|
|
out_ro:
|
|
ubi_ro_mode(ubi);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ubi_wl_put_peb - return a physical eraseblock to the wear-leveling unit.
|
|
* @ubi: UBI device description object
|
|
* @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 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);
|
|
|
|
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
|
|
* unit already re-mapped the LEB in 'ubi_eba_copy_leb()' but
|
|
* the WL unit 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);
|
|
return 0;
|
|
} else {
|
|
if (in_wl_tree(e, &ubi->used)) {
|
|
paranoid_check_in_wl_tree(e, &ubi->used);
|
|
rb_erase(&e->rb, &ubi->used);
|
|
} else if (in_wl_tree(e, &ubi->scrub)) {
|
|
paranoid_check_in_wl_tree(e, &ubi->scrub);
|
|
rb_erase(&e->rb, &ubi->scrub);
|
|
} else {
|
|
err = prot_tree_del(ubi, e->pnum);
|
|
if (err) {
|
|
ubi_err("PEB %d not found", pnum);
|
|
ubi_ro_mode(ubi);
|
|
spin_unlock(&ubi->wl_lock);
|
|
return err;
|
|
}
|
|
}
|
|
}
|
|
spin_unlock(&ubi->wl_lock);
|
|
|
|
err = schedule_erase(ubi, e, torture);
|
|
if (err) {
|
|
spin_lock(&ubi->wl_lock);
|
|
wl_tree_add(e, &ubi->used);
|
|
spin_unlock(&ubi->wl_lock);
|
|
}
|
|
|
|
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("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)) {
|
|
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)) {
|
|
paranoid_check_in_wl_tree(e, &ubi->used);
|
|
rb_erase(&e->rb, &ubi->used);
|
|
} else {
|
|
int err;
|
|
|
|
err = prot_tree_del(ubi, e->pnum);
|
|
if (err) {
|
|
ubi_err("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);
|
|
}
|
|
|
|
/**
|
|
* ubi_wl_flush - flush all pending works.
|
|
* @ubi: UBI device description object
|
|
*
|
|
* This function returns zero in case of success and a negative error code in
|
|
* case of failure.
|
|
*/
|
|
int ubi_wl_flush(struct ubi_device *ubi)
|
|
{
|
|
int err;
|
|
|
|
/*
|
|
* Erase while the pending works queue is not empty, but not more then
|
|
* the number of currently pending works.
|
|
*/
|
|
dbg_wl("flush (%d pending works)", ubi->works_count);
|
|
while (ubi->works_count) {
|
|
err = do_work(ubi);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Make sure all the works which have been done in parallel are
|
|
* finished.
|
|
*/
|
|
down_write(&ubi->work_sem);
|
|
up_write(&ubi->work_sem);
|
|
|
|
/*
|
|
* And in case last was the WL worker and it cancelled the LEB
|
|
* movement, flush again.
|
|
*/
|
|
while (ubi->works_count) {
|
|
dbg_wl("flush more (%d pending works)", ubi->works_count);
|
|
err = do_work(ubi);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* tree_destroy - destroy an RB-tree.
|
|
* @root: the root of the tree to destroy
|
|
*/
|
|
static void tree_destroy(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, rb);
|
|
|
|
rb = rb_parent(rb);
|
|
if (rb) {
|
|
if (rb->rb_left == &e->rb)
|
|
rb->rb_left = NULL;
|
|
else
|
|
rb->rb_right = NULL;
|
|
}
|
|
|
|
kmem_cache_free(ubi_wl_entry_slab, 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("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) {
|
|
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("%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("%s: %d consecutive failures",
|
|
ubi->bgt_name, WL_MAX_FAILURES);
|
|
ubi_ro_mode(ubi);
|
|
break;
|
|
}
|
|
} else
|
|
failures = 0;
|
|
|
|
cond_resched();
|
|
}
|
|
|
|
dbg_wl("background thread \"%s\" is killed", ubi->bgt_name);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* cancel_pending - cancel all pending works.
|
|
* @ubi: UBI device description object
|
|
*/
|
|
static void cancel_pending(struct ubi_device *ubi)
|
|
{
|
|
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_scan - initialize the wear-leveling unit using scanning
|
|
* information.
|
|
* @ubi: UBI device description object
|
|
* @si: scanning information
|
|
*
|
|
* This function returns zero in case of success, and a negative error code in
|
|
* case of failure.
|
|
*/
|
|
int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
|
|
{
|
|
int err;
|
|
struct rb_node *rb1, *rb2;
|
|
struct ubi_scan_volume *sv;
|
|
struct ubi_scan_leb *seb, *tmp;
|
|
struct ubi_wl_entry *e;
|
|
|
|
|
|
ubi->used = ubi->free = ubi->scrub = RB_ROOT;
|
|
ubi->prot.pnum = ubi->prot.aec = RB_ROOT;
|
|
spin_lock_init(&ubi->wl_lock);
|
|
mutex_init(&ubi->move_mutex);
|
|
init_rwsem(&ubi->work_sem);
|
|
ubi->max_ec = si->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;
|
|
|
|
list_for_each_entry_safe(seb, tmp, &si->erase, u.list) {
|
|
cond_resched();
|
|
|
|
e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
|
|
if (!e)
|
|
goto out_free;
|
|
|
|
e->pnum = seb->pnum;
|
|
e->ec = seb->ec;
|
|
ubi->lookuptbl[e->pnum] = e;
|
|
if (schedule_erase(ubi, e, 0)) {
|
|
kmem_cache_free(ubi_wl_entry_slab, e);
|
|
goto out_free;
|
|
}
|
|
}
|
|
|
|
list_for_each_entry(seb, &si->free, u.list) {
|
|
cond_resched();
|
|
|
|
e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
|
|
if (!e)
|
|
goto out_free;
|
|
|
|
e->pnum = seb->pnum;
|
|
e->ec = seb->ec;
|
|
ubi_assert(e->ec >= 0);
|
|
wl_tree_add(e, &ubi->free);
|
|
ubi->lookuptbl[e->pnum] = e;
|
|
}
|
|
|
|
list_for_each_entry(seb, &si->corr, u.list) {
|
|
cond_resched();
|
|
|
|
e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
|
|
if (!e)
|
|
goto out_free;
|
|
|
|
e->pnum = seb->pnum;
|
|
e->ec = seb->ec;
|
|
ubi->lookuptbl[e->pnum] = e;
|
|
if (schedule_erase(ubi, e, 0)) {
|
|
kmem_cache_free(ubi_wl_entry_slab, e);
|
|
goto out_free;
|
|
}
|
|
}
|
|
|
|
ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
|
|
ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
|
|
cond_resched();
|
|
|
|
e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
|
|
if (!e)
|
|
goto out_free;
|
|
|
|
e->pnum = seb->pnum;
|
|
e->ec = seb->ec;
|
|
ubi->lookuptbl[e->pnum] = e;
|
|
if (!seb->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);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (ubi->avail_pebs < WL_RESERVED_PEBS) {
|
|
ubi_err("no enough physical eraseblocks (%d, need %d)",
|
|
ubi->avail_pebs, WL_RESERVED_PEBS);
|
|
err = -ENOSPC;
|
|
goto out_free;
|
|
}
|
|
ubi->avail_pebs -= WL_RESERVED_PEBS;
|
|
ubi->rsvd_pebs += WL_RESERVED_PEBS;
|
|
|
|
/* Schedule wear-leveling if needed */
|
|
err = ensure_wear_leveling(ubi);
|
|
if (err)
|
|
goto out_free;
|
|
|
|
return 0;
|
|
|
|
out_free:
|
|
cancel_pending(ubi);
|
|
tree_destroy(&ubi->used);
|
|
tree_destroy(&ubi->free);
|
|
tree_destroy(&ubi->scrub);
|
|
kfree(ubi->lookuptbl);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* protection_trees_destroy - destroy the protection RB-trees.
|
|
* @ubi: UBI device description object
|
|
*/
|
|
static void protection_trees_destroy(struct ubi_device *ubi)
|
|
{
|
|
struct rb_node *rb;
|
|
struct ubi_wl_prot_entry *pe;
|
|
|
|
rb = ubi->prot.aec.rb_node;
|
|
while (rb) {
|
|
if (rb->rb_left)
|
|
rb = rb->rb_left;
|
|
else if (rb->rb_right)
|
|
rb = rb->rb_right;
|
|
else {
|
|
pe = rb_entry(rb, struct ubi_wl_prot_entry, rb_aec);
|
|
|
|
rb = rb_parent(rb);
|
|
if (rb) {
|
|
if (rb->rb_left == &pe->rb_aec)
|
|
rb->rb_left = NULL;
|
|
else
|
|
rb->rb_right = NULL;
|
|
}
|
|
|
|
kmem_cache_free(ubi_wl_entry_slab, pe->e);
|
|
kfree(pe);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* ubi_wl_close - close the wear-leveling unit.
|
|
* @ubi: UBI device description object
|
|
*/
|
|
void ubi_wl_close(struct ubi_device *ubi)
|
|
{
|
|
dbg_wl("close the UBI wear-leveling unit");
|
|
|
|
cancel_pending(ubi);
|
|
protection_trees_destroy(ubi);
|
|
tree_destroy(&ubi->used);
|
|
tree_destroy(&ubi->free);
|
|
tree_destroy(&ubi->scrub);
|
|
kfree(ubi->lookuptbl);
|
|
}
|
|
|
|
#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
|
|
|
|
/**
|
|
* paranoid_check_ec - make sure that the erase counter of a physical eraseblock
|
|
* 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, %1 if not, and a negative error code if an error
|
|
* occurred.
|
|
*/
|
|
static int paranoid_check_ec(struct ubi_device *ubi, int pnum, int ec)
|
|
{
|
|
int err;
|
|
long long read_ec;
|
|
struct ubi_ec_hdr *ec_hdr;
|
|
|
|
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) {
|
|
ubi_err("paranoid check failed for PEB %d", pnum);
|
|
ubi_err("read EC is %lld, should be %d", read_ec, ec);
|
|
ubi_dbg_dump_stack();
|
|
err = 1;
|
|
} else
|
|
err = 0;
|
|
|
|
out_free:
|
|
kfree(ec_hdr);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* paranoid_check_in_wl_tree - make sure that a wear-leveling entry is present
|
|
* in a WL RB-tree.
|
|
* @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 %1 if it
|
|
* is not.
|
|
*/
|
|
static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e,
|
|
struct rb_root *root)
|
|
{
|
|
if (in_wl_tree(e, root))
|
|
return 0;
|
|
|
|
ubi_err("paranoid check failed for PEB %d, EC %d, RB-tree %p ",
|
|
e->pnum, e->ec, root);
|
|
ubi_dbg_dump_stack();
|
|
return 1;
|
|
}
|
|
|
|
#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */
|