![Colin Ian King](/assets/img/avatar_default.png)
Don't populate the read-only array 'name' on the stack but instead make it static and constify it. Makes the object code smaller by 35 bytes: Before: text data bss dec hex filename 26304 4444 352 31100 797c drivers/mtd/mtdswap.o After: text data bss dec hex filename 26205 4508 352 31065 7959 drivers/mtd/mtdswap.o (gcc version 7.2.0 x86_64) Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
1570 lines
35 KiB
C
1570 lines
35 KiB
C
/*
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* Swap block device support for MTDs
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* Turns an MTD device into a swap device with block wear leveling
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*
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* Copyright © 2007,2011 Nokia Corporation. All rights reserved.
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*
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* Authors: Jarkko Lavinen <jarkko.lavinen@nokia.com>
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*
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* Based on Richard Purdie's earlier implementation in 2007. Background
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* support and lock-less operation written by Adrian Hunter.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* 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., 51 Franklin St, Fifth Floor, Boston, MA
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* 02110-1301 USA
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/blktrans.h>
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#include <linux/rbtree.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/genhd.h>
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#include <linux/swap.h>
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#include <linux/debugfs.h>
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#include <linux/seq_file.h>
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#include <linux/device.h>
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#include <linux/math64.h>
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#define MTDSWAP_PREFIX "mtdswap"
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/*
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* The number of free eraseblocks when GC should stop
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*/
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#define CLEAN_BLOCK_THRESHOLD 20
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/*
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* Number of free eraseblocks below which GC can also collect low frag
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* blocks.
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*/
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#define LOW_FRAG_GC_THRESHOLD 5
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/*
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* Wear level cost amortization. We want to do wear leveling on the background
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* without disturbing gc too much. This is made by defining max GC frequency.
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* Frequency value 6 means 1/6 of the GC passes will pick an erase block based
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* on the biggest wear difference rather than the biggest dirtiness.
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*
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* The lower freq2 should be chosen so that it makes sure the maximum erase
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* difference will decrease even if a malicious application is deliberately
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* trying to make erase differences large.
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*/
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#define MAX_ERASE_DIFF 4000
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#define COLLECT_NONDIRTY_BASE MAX_ERASE_DIFF
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#define COLLECT_NONDIRTY_FREQ1 6
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#define COLLECT_NONDIRTY_FREQ2 4
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#define PAGE_UNDEF UINT_MAX
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#define BLOCK_UNDEF UINT_MAX
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#define BLOCK_ERROR (UINT_MAX - 1)
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#define BLOCK_MAX (UINT_MAX - 2)
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#define EBLOCK_BAD (1 << 0)
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#define EBLOCK_NOMAGIC (1 << 1)
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#define EBLOCK_BITFLIP (1 << 2)
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#define EBLOCK_FAILED (1 << 3)
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#define EBLOCK_READERR (1 << 4)
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#define EBLOCK_IDX_SHIFT 5
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struct swap_eb {
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struct rb_node rb;
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struct rb_root *root;
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unsigned int flags;
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unsigned int active_count;
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unsigned int erase_count;
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unsigned int pad; /* speeds up pointer decrement */
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};
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#define MTDSWAP_ECNT_MIN(rbroot) (rb_entry(rb_first(rbroot), struct swap_eb, \
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rb)->erase_count)
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#define MTDSWAP_ECNT_MAX(rbroot) (rb_entry(rb_last(rbroot), struct swap_eb, \
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rb)->erase_count)
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struct mtdswap_tree {
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struct rb_root root;
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unsigned int count;
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};
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enum {
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MTDSWAP_CLEAN,
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MTDSWAP_USED,
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MTDSWAP_LOWFRAG,
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MTDSWAP_HIFRAG,
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MTDSWAP_DIRTY,
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MTDSWAP_BITFLIP,
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MTDSWAP_FAILING,
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MTDSWAP_TREE_CNT,
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};
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struct mtdswap_dev {
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struct mtd_blktrans_dev *mbd_dev;
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struct mtd_info *mtd;
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struct device *dev;
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unsigned int *page_data;
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unsigned int *revmap;
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unsigned int eblks;
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unsigned int spare_eblks;
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unsigned int pages_per_eblk;
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unsigned int max_erase_count;
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struct swap_eb *eb_data;
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struct mtdswap_tree trees[MTDSWAP_TREE_CNT];
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unsigned long long sect_read_count;
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unsigned long long sect_write_count;
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unsigned long long mtd_write_count;
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unsigned long long mtd_read_count;
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unsigned long long discard_count;
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unsigned long long discard_page_count;
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unsigned int curr_write_pos;
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struct swap_eb *curr_write;
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char *page_buf;
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char *oob_buf;
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};
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struct mtdswap_oobdata {
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__le16 magic;
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__le32 count;
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} __packed;
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#define MTDSWAP_MAGIC_CLEAN 0x2095
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#define MTDSWAP_MAGIC_DIRTY (MTDSWAP_MAGIC_CLEAN + 1)
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#define MTDSWAP_TYPE_CLEAN 0
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#define MTDSWAP_TYPE_DIRTY 1
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#define MTDSWAP_OOBSIZE sizeof(struct mtdswap_oobdata)
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#define MTDSWAP_ERASE_RETRIES 3 /* Before marking erase block bad */
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#define MTDSWAP_IO_RETRIES 3
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enum {
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MTDSWAP_SCANNED_CLEAN,
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MTDSWAP_SCANNED_DIRTY,
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MTDSWAP_SCANNED_BITFLIP,
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MTDSWAP_SCANNED_BAD,
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};
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/*
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* In the worst case mtdswap_writesect() has allocated the last clean
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* page from the current block and is then pre-empted by the GC
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* thread. The thread can consume a full erase block when moving a
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* block.
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*/
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#define MIN_SPARE_EBLOCKS 2
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#define MIN_ERASE_BLOCKS (MIN_SPARE_EBLOCKS + 1)
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#define TREE_ROOT(d, name) (&d->trees[MTDSWAP_ ## name].root)
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#define TREE_EMPTY(d, name) (TREE_ROOT(d, name)->rb_node == NULL)
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#define TREE_NONEMPTY(d, name) (!TREE_EMPTY(d, name))
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#define TREE_COUNT(d, name) (d->trees[MTDSWAP_ ## name].count)
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#define MTDSWAP_MBD_TO_MTDSWAP(dev) ((struct mtdswap_dev *)dev->priv)
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static char partitions[128] = "";
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module_param_string(partitions, partitions, sizeof(partitions), 0444);
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MODULE_PARM_DESC(partitions, "MTD partition numbers to use as swap "
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"partitions=\"1,3,5\"");
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static unsigned int spare_eblocks = 10;
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module_param(spare_eblocks, uint, 0444);
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MODULE_PARM_DESC(spare_eblocks, "Percentage of spare erase blocks for "
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"garbage collection (default 10%)");
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static bool header; /* false */
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module_param(header, bool, 0444);
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MODULE_PARM_DESC(header,
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"Include builtin swap header (default 0, without header)");
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static int mtdswap_gc(struct mtdswap_dev *d, unsigned int background);
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static loff_t mtdswap_eb_offset(struct mtdswap_dev *d, struct swap_eb *eb)
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{
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return (loff_t)(eb - d->eb_data) * d->mtd->erasesize;
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}
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static void mtdswap_eb_detach(struct mtdswap_dev *d, struct swap_eb *eb)
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{
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unsigned int oldidx;
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struct mtdswap_tree *tp;
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if (eb->root) {
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tp = container_of(eb->root, struct mtdswap_tree, root);
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oldidx = tp - &d->trees[0];
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d->trees[oldidx].count--;
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rb_erase(&eb->rb, eb->root);
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}
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}
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static void __mtdswap_rb_add(struct rb_root *root, struct swap_eb *eb)
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{
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struct rb_node **p, *parent = NULL;
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struct swap_eb *cur;
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p = &root->rb_node;
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while (*p) {
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parent = *p;
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cur = rb_entry(parent, struct swap_eb, rb);
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if (eb->erase_count > cur->erase_count)
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p = &(*p)->rb_right;
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else
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p = &(*p)->rb_left;
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}
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rb_link_node(&eb->rb, parent, p);
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rb_insert_color(&eb->rb, root);
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}
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static void mtdswap_rb_add(struct mtdswap_dev *d, struct swap_eb *eb, int idx)
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{
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struct rb_root *root;
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if (eb->root == &d->trees[idx].root)
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return;
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mtdswap_eb_detach(d, eb);
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root = &d->trees[idx].root;
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__mtdswap_rb_add(root, eb);
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eb->root = root;
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d->trees[idx].count++;
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}
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static struct rb_node *mtdswap_rb_index(struct rb_root *root, unsigned int idx)
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{
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struct rb_node *p;
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unsigned int i;
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p = rb_first(root);
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i = 0;
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while (i < idx && p) {
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p = rb_next(p);
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i++;
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}
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return p;
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}
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static int mtdswap_handle_badblock(struct mtdswap_dev *d, struct swap_eb *eb)
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{
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int ret;
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loff_t offset;
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d->spare_eblks--;
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eb->flags |= EBLOCK_BAD;
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mtdswap_eb_detach(d, eb);
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eb->root = NULL;
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/* badblocks not supported */
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if (!mtd_can_have_bb(d->mtd))
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return 1;
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offset = mtdswap_eb_offset(d, eb);
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dev_warn(d->dev, "Marking bad block at %08llx\n", offset);
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ret = mtd_block_markbad(d->mtd, offset);
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if (ret) {
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dev_warn(d->dev, "Mark block bad failed for block at %08llx "
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"error %d\n", offset, ret);
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return ret;
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}
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return 1;
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}
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static int mtdswap_handle_write_error(struct mtdswap_dev *d, struct swap_eb *eb)
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{
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unsigned int marked = eb->flags & EBLOCK_FAILED;
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struct swap_eb *curr_write = d->curr_write;
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eb->flags |= EBLOCK_FAILED;
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if (curr_write == eb) {
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d->curr_write = NULL;
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if (!marked && d->curr_write_pos != 0) {
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mtdswap_rb_add(d, eb, MTDSWAP_FAILING);
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return 0;
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}
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}
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return mtdswap_handle_badblock(d, eb);
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}
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static int mtdswap_read_oob(struct mtdswap_dev *d, loff_t from,
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struct mtd_oob_ops *ops)
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{
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int ret = mtd_read_oob(d->mtd, from, ops);
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if (mtd_is_bitflip(ret))
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return ret;
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if (ret) {
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dev_warn(d->dev, "Read OOB failed %d for block at %08llx\n",
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ret, from);
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return ret;
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}
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if (ops->oobretlen < ops->ooblen) {
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dev_warn(d->dev, "Read OOB return short read (%zd bytes not "
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"%zd) for block at %08llx\n",
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ops->oobretlen, ops->ooblen, from);
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return -EIO;
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}
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return 0;
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}
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static int mtdswap_read_markers(struct mtdswap_dev *d, struct swap_eb *eb)
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{
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struct mtdswap_oobdata *data, *data2;
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int ret;
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loff_t offset;
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struct mtd_oob_ops ops;
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offset = mtdswap_eb_offset(d, eb);
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/* Check first if the block is bad. */
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if (mtd_can_have_bb(d->mtd) && mtd_block_isbad(d->mtd, offset))
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return MTDSWAP_SCANNED_BAD;
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ops.ooblen = 2 * d->mtd->oobavail;
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ops.oobbuf = d->oob_buf;
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ops.ooboffs = 0;
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ops.datbuf = NULL;
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ops.mode = MTD_OPS_AUTO_OOB;
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ret = mtdswap_read_oob(d, offset, &ops);
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if (ret && !mtd_is_bitflip(ret))
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return ret;
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data = (struct mtdswap_oobdata *)d->oob_buf;
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data2 = (struct mtdswap_oobdata *)
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(d->oob_buf + d->mtd->oobavail);
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if (le16_to_cpu(data->magic) == MTDSWAP_MAGIC_CLEAN) {
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eb->erase_count = le32_to_cpu(data->count);
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if (mtd_is_bitflip(ret))
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ret = MTDSWAP_SCANNED_BITFLIP;
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else {
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if (le16_to_cpu(data2->magic) == MTDSWAP_MAGIC_DIRTY)
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ret = MTDSWAP_SCANNED_DIRTY;
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else
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ret = MTDSWAP_SCANNED_CLEAN;
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}
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} else {
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eb->flags |= EBLOCK_NOMAGIC;
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ret = MTDSWAP_SCANNED_DIRTY;
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}
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return ret;
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}
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static int mtdswap_write_marker(struct mtdswap_dev *d, struct swap_eb *eb,
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u16 marker)
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{
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struct mtdswap_oobdata n;
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int ret;
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loff_t offset;
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struct mtd_oob_ops ops;
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ops.ooboffs = 0;
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ops.oobbuf = (uint8_t *)&n;
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ops.mode = MTD_OPS_AUTO_OOB;
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ops.datbuf = NULL;
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if (marker == MTDSWAP_TYPE_CLEAN) {
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n.magic = cpu_to_le16(MTDSWAP_MAGIC_CLEAN);
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n.count = cpu_to_le32(eb->erase_count);
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ops.ooblen = MTDSWAP_OOBSIZE;
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offset = mtdswap_eb_offset(d, eb);
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} else {
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n.magic = cpu_to_le16(MTDSWAP_MAGIC_DIRTY);
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ops.ooblen = sizeof(n.magic);
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offset = mtdswap_eb_offset(d, eb) + d->mtd->writesize;
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}
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ret = mtd_write_oob(d->mtd, offset, &ops);
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if (ret) {
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dev_warn(d->dev, "Write OOB failed for block at %08llx "
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"error %d\n", offset, ret);
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if (ret == -EIO || mtd_is_eccerr(ret))
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mtdswap_handle_write_error(d, eb);
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return ret;
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}
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if (ops.oobretlen != ops.ooblen) {
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dev_warn(d->dev, "Short OOB write for block at %08llx: "
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"%zd not %zd\n",
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offset, ops.oobretlen, ops.ooblen);
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return ret;
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}
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return 0;
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}
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/*
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* Are there any erase blocks without MAGIC_CLEAN header, presumably
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* because power was cut off after erase but before header write? We
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* need to guestimate the erase count.
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*/
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static void mtdswap_check_counts(struct mtdswap_dev *d)
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{
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struct rb_root hist_root = RB_ROOT;
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struct rb_node *medrb;
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struct swap_eb *eb;
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unsigned int i, cnt, median;
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cnt = 0;
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for (i = 0; i < d->eblks; i++) {
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eb = d->eb_data + i;
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if (eb->flags & (EBLOCK_NOMAGIC | EBLOCK_BAD | EBLOCK_READERR))
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continue;
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__mtdswap_rb_add(&hist_root, eb);
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cnt++;
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}
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if (cnt == 0)
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return;
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medrb = mtdswap_rb_index(&hist_root, cnt / 2);
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median = rb_entry(medrb, struct swap_eb, rb)->erase_count;
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d->max_erase_count = MTDSWAP_ECNT_MAX(&hist_root);
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for (i = 0; i < d->eblks; i++) {
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eb = d->eb_data + i;
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if (eb->flags & (EBLOCK_NOMAGIC | EBLOCK_READERR))
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eb->erase_count = median;
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if (eb->flags & (EBLOCK_NOMAGIC | EBLOCK_BAD | EBLOCK_READERR))
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continue;
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rb_erase(&eb->rb, &hist_root);
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}
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}
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static void mtdswap_scan_eblks(struct mtdswap_dev *d)
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{
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int status;
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unsigned int i, idx;
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struct swap_eb *eb;
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for (i = 0; i < d->eblks; i++) {
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eb = d->eb_data + i;
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status = mtdswap_read_markers(d, eb);
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if (status < 0)
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eb->flags |= EBLOCK_READERR;
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else if (status == MTDSWAP_SCANNED_BAD) {
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eb->flags |= EBLOCK_BAD;
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continue;
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}
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switch (status) {
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case MTDSWAP_SCANNED_CLEAN:
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idx = MTDSWAP_CLEAN;
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break;
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case MTDSWAP_SCANNED_DIRTY:
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case MTDSWAP_SCANNED_BITFLIP:
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idx = MTDSWAP_DIRTY;
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break;
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default:
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idx = MTDSWAP_FAILING;
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}
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|
eb->flags |= (idx << EBLOCK_IDX_SHIFT);
|
|
}
|
|
|
|
mtdswap_check_counts(d);
|
|
|
|
for (i = 0; i < d->eblks; i++) {
|
|
eb = d->eb_data + i;
|
|
|
|
if (eb->flags & EBLOCK_BAD)
|
|
continue;
|
|
|
|
idx = eb->flags >> EBLOCK_IDX_SHIFT;
|
|
mtdswap_rb_add(d, eb, idx);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Place eblk into a tree corresponding to its number of active blocks
|
|
* it contains.
|
|
*/
|
|
static void mtdswap_store_eb(struct mtdswap_dev *d, struct swap_eb *eb)
|
|
{
|
|
unsigned int weight = eb->active_count;
|
|
unsigned int maxweight = d->pages_per_eblk;
|
|
|
|
if (eb == d->curr_write)
|
|
return;
|
|
|
|
if (eb->flags & EBLOCK_BITFLIP)
|
|
mtdswap_rb_add(d, eb, MTDSWAP_BITFLIP);
|
|
else if (eb->flags & (EBLOCK_READERR | EBLOCK_FAILED))
|
|
mtdswap_rb_add(d, eb, MTDSWAP_FAILING);
|
|
if (weight == maxweight)
|
|
mtdswap_rb_add(d, eb, MTDSWAP_USED);
|
|
else if (weight == 0)
|
|
mtdswap_rb_add(d, eb, MTDSWAP_DIRTY);
|
|
else if (weight > (maxweight/2))
|
|
mtdswap_rb_add(d, eb, MTDSWAP_LOWFRAG);
|
|
else
|
|
mtdswap_rb_add(d, eb, MTDSWAP_HIFRAG);
|
|
}
|
|
|
|
|
|
static void mtdswap_erase_callback(struct erase_info *done)
|
|
{
|
|
wait_queue_head_t *wait_q = (wait_queue_head_t *)done->priv;
|
|
wake_up(wait_q);
|
|
}
|
|
|
|
static int mtdswap_erase_block(struct mtdswap_dev *d, struct swap_eb *eb)
|
|
{
|
|
struct mtd_info *mtd = d->mtd;
|
|
struct erase_info erase;
|
|
wait_queue_head_t wq;
|
|
unsigned int retries = 0;
|
|
int ret;
|
|
|
|
eb->erase_count++;
|
|
if (eb->erase_count > d->max_erase_count)
|
|
d->max_erase_count = eb->erase_count;
|
|
|
|
retry:
|
|
init_waitqueue_head(&wq);
|
|
memset(&erase, 0, sizeof(struct erase_info));
|
|
|
|
erase.mtd = mtd;
|
|
erase.callback = mtdswap_erase_callback;
|
|
erase.addr = mtdswap_eb_offset(d, eb);
|
|
erase.len = mtd->erasesize;
|
|
erase.priv = (u_long)&wq;
|
|
|
|
ret = mtd_erase(mtd, &erase);
|
|
if (ret) {
|
|
if (retries++ < MTDSWAP_ERASE_RETRIES) {
|
|
dev_warn(d->dev,
|
|
"erase of erase block %#llx on %s failed",
|
|
erase.addr, mtd->name);
|
|
yield();
|
|
goto retry;
|
|
}
|
|
|
|
dev_err(d->dev, "Cannot erase erase block %#llx on %s\n",
|
|
erase.addr, mtd->name);
|
|
|
|
mtdswap_handle_badblock(d, eb);
|
|
return -EIO;
|
|
}
|
|
|
|
ret = wait_event_interruptible(wq, erase.state == MTD_ERASE_DONE ||
|
|
erase.state == MTD_ERASE_FAILED);
|
|
if (ret) {
|
|
dev_err(d->dev, "Interrupted erase block %#llx erasure on %s\n",
|
|
erase.addr, mtd->name);
|
|
return -EINTR;
|
|
}
|
|
|
|
if (erase.state == MTD_ERASE_FAILED) {
|
|
if (retries++ < MTDSWAP_ERASE_RETRIES) {
|
|
dev_warn(d->dev,
|
|
"erase of erase block %#llx on %s failed",
|
|
erase.addr, mtd->name);
|
|
yield();
|
|
goto retry;
|
|
}
|
|
|
|
mtdswap_handle_badblock(d, eb);
|
|
return -EIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mtdswap_map_free_block(struct mtdswap_dev *d, unsigned int page,
|
|
unsigned int *block)
|
|
{
|
|
int ret;
|
|
struct swap_eb *old_eb = d->curr_write;
|
|
struct rb_root *clean_root;
|
|
struct swap_eb *eb;
|
|
|
|
if (old_eb == NULL || d->curr_write_pos >= d->pages_per_eblk) {
|
|
do {
|
|
if (TREE_EMPTY(d, CLEAN))
|
|
return -ENOSPC;
|
|
|
|
clean_root = TREE_ROOT(d, CLEAN);
|
|
eb = rb_entry(rb_first(clean_root), struct swap_eb, rb);
|
|
rb_erase(&eb->rb, clean_root);
|
|
eb->root = NULL;
|
|
TREE_COUNT(d, CLEAN)--;
|
|
|
|
ret = mtdswap_write_marker(d, eb, MTDSWAP_TYPE_DIRTY);
|
|
} while (ret == -EIO || mtd_is_eccerr(ret));
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
d->curr_write_pos = 0;
|
|
d->curr_write = eb;
|
|
if (old_eb)
|
|
mtdswap_store_eb(d, old_eb);
|
|
}
|
|
|
|
*block = (d->curr_write - d->eb_data) * d->pages_per_eblk +
|
|
d->curr_write_pos;
|
|
|
|
d->curr_write->active_count++;
|
|
d->revmap[*block] = page;
|
|
d->curr_write_pos++;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned int mtdswap_free_page_cnt(struct mtdswap_dev *d)
|
|
{
|
|
return TREE_COUNT(d, CLEAN) * d->pages_per_eblk +
|
|
d->pages_per_eblk - d->curr_write_pos;
|
|
}
|
|
|
|
static unsigned int mtdswap_enough_free_pages(struct mtdswap_dev *d)
|
|
{
|
|
return mtdswap_free_page_cnt(d) > d->pages_per_eblk;
|
|
}
|
|
|
|
static int mtdswap_write_block(struct mtdswap_dev *d, char *buf,
|
|
unsigned int page, unsigned int *bp, int gc_context)
|
|
{
|
|
struct mtd_info *mtd = d->mtd;
|
|
struct swap_eb *eb;
|
|
size_t retlen;
|
|
loff_t writepos;
|
|
int ret;
|
|
|
|
retry:
|
|
if (!gc_context)
|
|
while (!mtdswap_enough_free_pages(d))
|
|
if (mtdswap_gc(d, 0) > 0)
|
|
return -ENOSPC;
|
|
|
|
ret = mtdswap_map_free_block(d, page, bp);
|
|
eb = d->eb_data + (*bp / d->pages_per_eblk);
|
|
|
|
if (ret == -EIO || mtd_is_eccerr(ret)) {
|
|
d->curr_write = NULL;
|
|
eb->active_count--;
|
|
d->revmap[*bp] = PAGE_UNDEF;
|
|
goto retry;
|
|
}
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
writepos = (loff_t)*bp << PAGE_SHIFT;
|
|
ret = mtd_write(mtd, writepos, PAGE_SIZE, &retlen, buf);
|
|
if (ret == -EIO || mtd_is_eccerr(ret)) {
|
|
d->curr_write_pos--;
|
|
eb->active_count--;
|
|
d->revmap[*bp] = PAGE_UNDEF;
|
|
mtdswap_handle_write_error(d, eb);
|
|
goto retry;
|
|
}
|
|
|
|
if (ret < 0) {
|
|
dev_err(d->dev, "Write to MTD device failed: %d (%zd written)",
|
|
ret, retlen);
|
|
goto err;
|
|
}
|
|
|
|
if (retlen != PAGE_SIZE) {
|
|
dev_err(d->dev, "Short write to MTD device: %zd written",
|
|
retlen);
|
|
ret = -EIO;
|
|
goto err;
|
|
}
|
|
|
|
return ret;
|
|
|
|
err:
|
|
d->curr_write_pos--;
|
|
eb->active_count--;
|
|
d->revmap[*bp] = PAGE_UNDEF;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mtdswap_move_block(struct mtdswap_dev *d, unsigned int oldblock,
|
|
unsigned int *newblock)
|
|
{
|
|
struct mtd_info *mtd = d->mtd;
|
|
struct swap_eb *eb, *oldeb;
|
|
int ret;
|
|
size_t retlen;
|
|
unsigned int page, retries;
|
|
loff_t readpos;
|
|
|
|
page = d->revmap[oldblock];
|
|
readpos = (loff_t) oldblock << PAGE_SHIFT;
|
|
retries = 0;
|
|
|
|
retry:
|
|
ret = mtd_read(mtd, readpos, PAGE_SIZE, &retlen, d->page_buf);
|
|
|
|
if (ret < 0 && !mtd_is_bitflip(ret)) {
|
|
oldeb = d->eb_data + oldblock / d->pages_per_eblk;
|
|
oldeb->flags |= EBLOCK_READERR;
|
|
|
|
dev_err(d->dev, "Read Error: %d (block %u)\n", ret,
|
|
oldblock);
|
|
retries++;
|
|
if (retries < MTDSWAP_IO_RETRIES)
|
|
goto retry;
|
|
|
|
goto read_error;
|
|
}
|
|
|
|
if (retlen != PAGE_SIZE) {
|
|
dev_err(d->dev, "Short read: %zd (block %u)\n", retlen,
|
|
oldblock);
|
|
ret = -EIO;
|
|
goto read_error;
|
|
}
|
|
|
|
ret = mtdswap_write_block(d, d->page_buf, page, newblock, 1);
|
|
if (ret < 0) {
|
|
d->page_data[page] = BLOCK_ERROR;
|
|
dev_err(d->dev, "Write error: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
eb = d->eb_data + *newblock / d->pages_per_eblk;
|
|
d->page_data[page] = *newblock;
|
|
d->revmap[oldblock] = PAGE_UNDEF;
|
|
eb = d->eb_data + oldblock / d->pages_per_eblk;
|
|
eb->active_count--;
|
|
|
|
return 0;
|
|
|
|
read_error:
|
|
d->page_data[page] = BLOCK_ERROR;
|
|
d->revmap[oldblock] = PAGE_UNDEF;
|
|
return ret;
|
|
}
|
|
|
|
static int mtdswap_gc_eblock(struct mtdswap_dev *d, struct swap_eb *eb)
|
|
{
|
|
unsigned int i, block, eblk_base, newblock;
|
|
int ret, errcode;
|
|
|
|
errcode = 0;
|
|
eblk_base = (eb - d->eb_data) * d->pages_per_eblk;
|
|
|
|
for (i = 0; i < d->pages_per_eblk; i++) {
|
|
if (d->spare_eblks < MIN_SPARE_EBLOCKS)
|
|
return -ENOSPC;
|
|
|
|
block = eblk_base + i;
|
|
if (d->revmap[block] == PAGE_UNDEF)
|
|
continue;
|
|
|
|
ret = mtdswap_move_block(d, block, &newblock);
|
|
if (ret < 0 && !errcode)
|
|
errcode = ret;
|
|
}
|
|
|
|
return errcode;
|
|
}
|
|
|
|
static int __mtdswap_choose_gc_tree(struct mtdswap_dev *d)
|
|
{
|
|
int idx, stopat;
|
|
|
|
if (TREE_COUNT(d, CLEAN) < LOW_FRAG_GC_THRESHOLD)
|
|
stopat = MTDSWAP_LOWFRAG;
|
|
else
|
|
stopat = MTDSWAP_HIFRAG;
|
|
|
|
for (idx = MTDSWAP_BITFLIP; idx >= stopat; idx--)
|
|
if (d->trees[idx].root.rb_node != NULL)
|
|
return idx;
|
|
|
|
return -1;
|
|
}
|
|
|
|
static int mtdswap_wlfreq(unsigned int maxdiff)
|
|
{
|
|
unsigned int h, x, y, dist, base;
|
|
|
|
/*
|
|
* Calculate linear ramp down from f1 to f2 when maxdiff goes from
|
|
* MAX_ERASE_DIFF to MAX_ERASE_DIFF + COLLECT_NONDIRTY_BASE. Similar
|
|
* to triangle with height f1 - f1 and width COLLECT_NONDIRTY_BASE.
|
|
*/
|
|
|
|
dist = maxdiff - MAX_ERASE_DIFF;
|
|
if (dist > COLLECT_NONDIRTY_BASE)
|
|
dist = COLLECT_NONDIRTY_BASE;
|
|
|
|
/*
|
|
* Modelling the slop as right angular triangle with base
|
|
* COLLECT_NONDIRTY_BASE and height freq1 - freq2. The ratio y/x is
|
|
* equal to the ratio h/base.
|
|
*/
|
|
h = COLLECT_NONDIRTY_FREQ1 - COLLECT_NONDIRTY_FREQ2;
|
|
base = COLLECT_NONDIRTY_BASE;
|
|
|
|
x = dist - base;
|
|
y = (x * h + base / 2) / base;
|
|
|
|
return COLLECT_NONDIRTY_FREQ2 + y;
|
|
}
|
|
|
|
static int mtdswap_choose_wl_tree(struct mtdswap_dev *d)
|
|
{
|
|
static unsigned int pick_cnt;
|
|
unsigned int i, idx = -1, wear, max;
|
|
struct rb_root *root;
|
|
|
|
max = 0;
|
|
for (i = 0; i <= MTDSWAP_DIRTY; i++) {
|
|
root = &d->trees[i].root;
|
|
if (root->rb_node == NULL)
|
|
continue;
|
|
|
|
wear = d->max_erase_count - MTDSWAP_ECNT_MIN(root);
|
|
if (wear > max) {
|
|
max = wear;
|
|
idx = i;
|
|
}
|
|
}
|
|
|
|
if (max > MAX_ERASE_DIFF && pick_cnt >= mtdswap_wlfreq(max) - 1) {
|
|
pick_cnt = 0;
|
|
return idx;
|
|
}
|
|
|
|
pick_cnt++;
|
|
return -1;
|
|
}
|
|
|
|
static int mtdswap_choose_gc_tree(struct mtdswap_dev *d,
|
|
unsigned int background)
|
|
{
|
|
int idx;
|
|
|
|
if (TREE_NONEMPTY(d, FAILING) &&
|
|
(background || (TREE_EMPTY(d, CLEAN) && TREE_EMPTY(d, DIRTY))))
|
|
return MTDSWAP_FAILING;
|
|
|
|
idx = mtdswap_choose_wl_tree(d);
|
|
if (idx >= MTDSWAP_CLEAN)
|
|
return idx;
|
|
|
|
return __mtdswap_choose_gc_tree(d);
|
|
}
|
|
|
|
static struct swap_eb *mtdswap_pick_gc_eblk(struct mtdswap_dev *d,
|
|
unsigned int background)
|
|
{
|
|
struct rb_root *rp = NULL;
|
|
struct swap_eb *eb = NULL;
|
|
int idx;
|
|
|
|
if (background && TREE_COUNT(d, CLEAN) > CLEAN_BLOCK_THRESHOLD &&
|
|
TREE_EMPTY(d, DIRTY) && TREE_EMPTY(d, FAILING))
|
|
return NULL;
|
|
|
|
idx = mtdswap_choose_gc_tree(d, background);
|
|
if (idx < 0)
|
|
return NULL;
|
|
|
|
rp = &d->trees[idx].root;
|
|
eb = rb_entry(rb_first(rp), struct swap_eb, rb);
|
|
|
|
rb_erase(&eb->rb, rp);
|
|
eb->root = NULL;
|
|
d->trees[idx].count--;
|
|
return eb;
|
|
}
|
|
|
|
static unsigned int mtdswap_test_patt(unsigned int i)
|
|
{
|
|
return i % 2 ? 0x55555555 : 0xAAAAAAAA;
|
|
}
|
|
|
|
static unsigned int mtdswap_eblk_passes(struct mtdswap_dev *d,
|
|
struct swap_eb *eb)
|
|
{
|
|
struct mtd_info *mtd = d->mtd;
|
|
unsigned int test, i, j, patt, mtd_pages;
|
|
loff_t base, pos;
|
|
unsigned int *p1 = (unsigned int *)d->page_buf;
|
|
unsigned char *p2 = (unsigned char *)d->oob_buf;
|
|
struct mtd_oob_ops ops;
|
|
int ret;
|
|
|
|
ops.mode = MTD_OPS_AUTO_OOB;
|
|
ops.len = mtd->writesize;
|
|
ops.ooblen = mtd->oobavail;
|
|
ops.ooboffs = 0;
|
|
ops.datbuf = d->page_buf;
|
|
ops.oobbuf = d->oob_buf;
|
|
base = mtdswap_eb_offset(d, eb);
|
|
mtd_pages = d->pages_per_eblk * PAGE_SIZE / mtd->writesize;
|
|
|
|
for (test = 0; test < 2; test++) {
|
|
pos = base;
|
|
for (i = 0; i < mtd_pages; i++) {
|
|
patt = mtdswap_test_patt(test + i);
|
|
memset(d->page_buf, patt, mtd->writesize);
|
|
memset(d->oob_buf, patt, mtd->oobavail);
|
|
ret = mtd_write_oob(mtd, pos, &ops);
|
|
if (ret)
|
|
goto error;
|
|
|
|
pos += mtd->writesize;
|
|
}
|
|
|
|
pos = base;
|
|
for (i = 0; i < mtd_pages; i++) {
|
|
ret = mtd_read_oob(mtd, pos, &ops);
|
|
if (ret)
|
|
goto error;
|
|
|
|
patt = mtdswap_test_patt(test + i);
|
|
for (j = 0; j < mtd->writesize/sizeof(int); j++)
|
|
if (p1[j] != patt)
|
|
goto error;
|
|
|
|
for (j = 0; j < mtd->oobavail; j++)
|
|
if (p2[j] != (unsigned char)patt)
|
|
goto error;
|
|
|
|
pos += mtd->writesize;
|
|
}
|
|
|
|
ret = mtdswap_erase_block(d, eb);
|
|
if (ret)
|
|
goto error;
|
|
}
|
|
|
|
eb->flags &= ~EBLOCK_READERR;
|
|
return 1;
|
|
|
|
error:
|
|
mtdswap_handle_badblock(d, eb);
|
|
return 0;
|
|
}
|
|
|
|
static int mtdswap_gc(struct mtdswap_dev *d, unsigned int background)
|
|
{
|
|
struct swap_eb *eb;
|
|
int ret;
|
|
|
|
if (d->spare_eblks < MIN_SPARE_EBLOCKS)
|
|
return 1;
|
|
|
|
eb = mtdswap_pick_gc_eblk(d, background);
|
|
if (!eb)
|
|
return 1;
|
|
|
|
ret = mtdswap_gc_eblock(d, eb);
|
|
if (ret == -ENOSPC)
|
|
return 1;
|
|
|
|
if (eb->flags & EBLOCK_FAILED) {
|
|
mtdswap_handle_badblock(d, eb);
|
|
return 0;
|
|
}
|
|
|
|
eb->flags &= ~EBLOCK_BITFLIP;
|
|
ret = mtdswap_erase_block(d, eb);
|
|
if ((eb->flags & EBLOCK_READERR) &&
|
|
(ret || !mtdswap_eblk_passes(d, eb)))
|
|
return 0;
|
|
|
|
if (ret == 0)
|
|
ret = mtdswap_write_marker(d, eb, MTDSWAP_TYPE_CLEAN);
|
|
|
|
if (ret == 0)
|
|
mtdswap_rb_add(d, eb, MTDSWAP_CLEAN);
|
|
else if (ret != -EIO && !mtd_is_eccerr(ret))
|
|
mtdswap_rb_add(d, eb, MTDSWAP_DIRTY);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void mtdswap_background(struct mtd_blktrans_dev *dev)
|
|
{
|
|
struct mtdswap_dev *d = MTDSWAP_MBD_TO_MTDSWAP(dev);
|
|
int ret;
|
|
|
|
while (1) {
|
|
ret = mtdswap_gc(d, 1);
|
|
if (ret || mtd_blktrans_cease_background(dev))
|
|
return;
|
|
}
|
|
}
|
|
|
|
static void mtdswap_cleanup(struct mtdswap_dev *d)
|
|
{
|
|
vfree(d->eb_data);
|
|
vfree(d->revmap);
|
|
vfree(d->page_data);
|
|
kfree(d->oob_buf);
|
|
kfree(d->page_buf);
|
|
}
|
|
|
|
static int mtdswap_flush(struct mtd_blktrans_dev *dev)
|
|
{
|
|
struct mtdswap_dev *d = MTDSWAP_MBD_TO_MTDSWAP(dev);
|
|
|
|
mtd_sync(d->mtd);
|
|
return 0;
|
|
}
|
|
|
|
static unsigned int mtdswap_badblocks(struct mtd_info *mtd, uint64_t size)
|
|
{
|
|
loff_t offset;
|
|
unsigned int badcnt;
|
|
|
|
badcnt = 0;
|
|
|
|
if (mtd_can_have_bb(mtd))
|
|
for (offset = 0; offset < size; offset += mtd->erasesize)
|
|
if (mtd_block_isbad(mtd, offset))
|
|
badcnt++;
|
|
|
|
return badcnt;
|
|
}
|
|
|
|
static int mtdswap_writesect(struct mtd_blktrans_dev *dev,
|
|
unsigned long page, char *buf)
|
|
{
|
|
struct mtdswap_dev *d = MTDSWAP_MBD_TO_MTDSWAP(dev);
|
|
unsigned int newblock, mapped;
|
|
struct swap_eb *eb;
|
|
int ret;
|
|
|
|
d->sect_write_count++;
|
|
|
|
if (d->spare_eblks < MIN_SPARE_EBLOCKS)
|
|
return -ENOSPC;
|
|
|
|
if (header) {
|
|
/* Ignore writes to the header page */
|
|
if (unlikely(page == 0))
|
|
return 0;
|
|
|
|
page--;
|
|
}
|
|
|
|
mapped = d->page_data[page];
|
|
if (mapped <= BLOCK_MAX) {
|
|
eb = d->eb_data + (mapped / d->pages_per_eblk);
|
|
eb->active_count--;
|
|
mtdswap_store_eb(d, eb);
|
|
d->page_data[page] = BLOCK_UNDEF;
|
|
d->revmap[mapped] = PAGE_UNDEF;
|
|
}
|
|
|
|
ret = mtdswap_write_block(d, buf, page, &newblock, 0);
|
|
d->mtd_write_count++;
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
eb = d->eb_data + (newblock / d->pages_per_eblk);
|
|
d->page_data[page] = newblock;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Provide a dummy swap header for the kernel */
|
|
static int mtdswap_auto_header(struct mtdswap_dev *d, char *buf)
|
|
{
|
|
union swap_header *hd = (union swap_header *)(buf);
|
|
|
|
memset(buf, 0, PAGE_SIZE - 10);
|
|
|
|
hd->info.version = 1;
|
|
hd->info.last_page = d->mbd_dev->size - 1;
|
|
hd->info.nr_badpages = 0;
|
|
|
|
memcpy(buf + PAGE_SIZE - 10, "SWAPSPACE2", 10);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mtdswap_readsect(struct mtd_blktrans_dev *dev,
|
|
unsigned long page, char *buf)
|
|
{
|
|
struct mtdswap_dev *d = MTDSWAP_MBD_TO_MTDSWAP(dev);
|
|
struct mtd_info *mtd = d->mtd;
|
|
unsigned int realblock, retries;
|
|
loff_t readpos;
|
|
struct swap_eb *eb;
|
|
size_t retlen;
|
|
int ret;
|
|
|
|
d->sect_read_count++;
|
|
|
|
if (header) {
|
|
if (unlikely(page == 0))
|
|
return mtdswap_auto_header(d, buf);
|
|
|
|
page--;
|
|
}
|
|
|
|
realblock = d->page_data[page];
|
|
if (realblock > BLOCK_MAX) {
|
|
memset(buf, 0x0, PAGE_SIZE);
|
|
if (realblock == BLOCK_UNDEF)
|
|
return 0;
|
|
else
|
|
return -EIO;
|
|
}
|
|
|
|
eb = d->eb_data + (realblock / d->pages_per_eblk);
|
|
BUG_ON(d->revmap[realblock] == PAGE_UNDEF);
|
|
|
|
readpos = (loff_t)realblock << PAGE_SHIFT;
|
|
retries = 0;
|
|
|
|
retry:
|
|
ret = mtd_read(mtd, readpos, PAGE_SIZE, &retlen, buf);
|
|
|
|
d->mtd_read_count++;
|
|
if (mtd_is_bitflip(ret)) {
|
|
eb->flags |= EBLOCK_BITFLIP;
|
|
mtdswap_rb_add(d, eb, MTDSWAP_BITFLIP);
|
|
ret = 0;
|
|
}
|
|
|
|
if (ret < 0) {
|
|
dev_err(d->dev, "Read error %d\n", ret);
|
|
eb->flags |= EBLOCK_READERR;
|
|
mtdswap_rb_add(d, eb, MTDSWAP_FAILING);
|
|
retries++;
|
|
if (retries < MTDSWAP_IO_RETRIES)
|
|
goto retry;
|
|
|
|
return ret;
|
|
}
|
|
|
|
if (retlen != PAGE_SIZE) {
|
|
dev_err(d->dev, "Short read %zd\n", retlen);
|
|
return -EIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mtdswap_discard(struct mtd_blktrans_dev *dev, unsigned long first,
|
|
unsigned nr_pages)
|
|
{
|
|
struct mtdswap_dev *d = MTDSWAP_MBD_TO_MTDSWAP(dev);
|
|
unsigned long page;
|
|
struct swap_eb *eb;
|
|
unsigned int mapped;
|
|
|
|
d->discard_count++;
|
|
|
|
for (page = first; page < first + nr_pages; page++) {
|
|
mapped = d->page_data[page];
|
|
if (mapped <= BLOCK_MAX) {
|
|
eb = d->eb_data + (mapped / d->pages_per_eblk);
|
|
eb->active_count--;
|
|
mtdswap_store_eb(d, eb);
|
|
d->page_data[page] = BLOCK_UNDEF;
|
|
d->revmap[mapped] = PAGE_UNDEF;
|
|
d->discard_page_count++;
|
|
} else if (mapped == BLOCK_ERROR) {
|
|
d->page_data[page] = BLOCK_UNDEF;
|
|
d->discard_page_count++;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mtdswap_show(struct seq_file *s, void *data)
|
|
{
|
|
struct mtdswap_dev *d = (struct mtdswap_dev *) s->private;
|
|
unsigned long sum;
|
|
unsigned int count[MTDSWAP_TREE_CNT];
|
|
unsigned int min[MTDSWAP_TREE_CNT];
|
|
unsigned int max[MTDSWAP_TREE_CNT];
|
|
unsigned int i, cw = 0, cwp = 0, cwecount = 0, bb_cnt, mapped, pages;
|
|
uint64_t use_size;
|
|
static const char * const name[] = {
|
|
"clean", "used", "low", "high", "dirty", "bitflip", "failing"
|
|
};
|
|
|
|
mutex_lock(&d->mbd_dev->lock);
|
|
|
|
for (i = 0; i < MTDSWAP_TREE_CNT; i++) {
|
|
struct rb_root *root = &d->trees[i].root;
|
|
|
|
if (root->rb_node) {
|
|
count[i] = d->trees[i].count;
|
|
min[i] = MTDSWAP_ECNT_MIN(root);
|
|
max[i] = MTDSWAP_ECNT_MAX(root);
|
|
} else
|
|
count[i] = 0;
|
|
}
|
|
|
|
if (d->curr_write) {
|
|
cw = 1;
|
|
cwp = d->curr_write_pos;
|
|
cwecount = d->curr_write->erase_count;
|
|
}
|
|
|
|
sum = 0;
|
|
for (i = 0; i < d->eblks; i++)
|
|
sum += d->eb_data[i].erase_count;
|
|
|
|
use_size = (uint64_t)d->eblks * d->mtd->erasesize;
|
|
bb_cnt = mtdswap_badblocks(d->mtd, use_size);
|
|
|
|
mapped = 0;
|
|
pages = d->mbd_dev->size;
|
|
for (i = 0; i < pages; i++)
|
|
if (d->page_data[i] != BLOCK_UNDEF)
|
|
mapped++;
|
|
|
|
mutex_unlock(&d->mbd_dev->lock);
|
|
|
|
for (i = 0; i < MTDSWAP_TREE_CNT; i++) {
|
|
if (!count[i])
|
|
continue;
|
|
|
|
if (min[i] != max[i])
|
|
seq_printf(s, "%s:\t%5d erase blocks, erased min %d, "
|
|
"max %d times\n",
|
|
name[i], count[i], min[i], max[i]);
|
|
else
|
|
seq_printf(s, "%s:\t%5d erase blocks, all erased %d "
|
|
"times\n", name[i], count[i], min[i]);
|
|
}
|
|
|
|
if (bb_cnt)
|
|
seq_printf(s, "bad:\t%5u erase blocks\n", bb_cnt);
|
|
|
|
if (cw)
|
|
seq_printf(s, "current erase block: %u pages used, %u free, "
|
|
"erased %u times\n",
|
|
cwp, d->pages_per_eblk - cwp, cwecount);
|
|
|
|
seq_printf(s, "total erasures: %lu\n", sum);
|
|
|
|
seq_puts(s, "\n");
|
|
|
|
seq_printf(s, "mtdswap_readsect count: %llu\n", d->sect_read_count);
|
|
seq_printf(s, "mtdswap_writesect count: %llu\n", d->sect_write_count);
|
|
seq_printf(s, "mtdswap_discard count: %llu\n", d->discard_count);
|
|
seq_printf(s, "mtd read count: %llu\n", d->mtd_read_count);
|
|
seq_printf(s, "mtd write count: %llu\n", d->mtd_write_count);
|
|
seq_printf(s, "discarded pages count: %llu\n", d->discard_page_count);
|
|
|
|
seq_puts(s, "\n");
|
|
seq_printf(s, "total pages: %u\n", pages);
|
|
seq_printf(s, "pages mapped: %u\n", mapped);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mtdswap_open(struct inode *inode, struct file *file)
|
|
{
|
|
return single_open(file, mtdswap_show, inode->i_private);
|
|
}
|
|
|
|
static const struct file_operations mtdswap_fops = {
|
|
.open = mtdswap_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = single_release,
|
|
};
|
|
|
|
static int mtdswap_add_debugfs(struct mtdswap_dev *d)
|
|
{
|
|
struct dentry *root = d->mtd->dbg.dfs_dir;
|
|
struct dentry *dent;
|
|
|
|
if (!IS_ENABLED(CONFIG_DEBUG_FS))
|
|
return 0;
|
|
|
|
if (IS_ERR_OR_NULL(root))
|
|
return -1;
|
|
|
|
dent = debugfs_create_file("mtdswap_stats", S_IRUSR, root, d,
|
|
&mtdswap_fops);
|
|
if (!dent) {
|
|
dev_err(d->dev, "debugfs_create_file failed\n");
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mtdswap_init(struct mtdswap_dev *d, unsigned int eblocks,
|
|
unsigned int spare_cnt)
|
|
{
|
|
struct mtd_info *mtd = d->mbd_dev->mtd;
|
|
unsigned int i, eblk_bytes, pages, blocks;
|
|
int ret = -ENOMEM;
|
|
|
|
d->mtd = mtd;
|
|
d->eblks = eblocks;
|
|
d->spare_eblks = spare_cnt;
|
|
d->pages_per_eblk = mtd->erasesize >> PAGE_SHIFT;
|
|
|
|
pages = d->mbd_dev->size;
|
|
blocks = eblocks * d->pages_per_eblk;
|
|
|
|
for (i = 0; i < MTDSWAP_TREE_CNT; i++)
|
|
d->trees[i].root = RB_ROOT;
|
|
|
|
d->page_data = vmalloc(sizeof(int)*pages);
|
|
if (!d->page_data)
|
|
goto page_data_fail;
|
|
|
|
d->revmap = vmalloc(sizeof(int)*blocks);
|
|
if (!d->revmap)
|
|
goto revmap_fail;
|
|
|
|
eblk_bytes = sizeof(struct swap_eb)*d->eblks;
|
|
d->eb_data = vzalloc(eblk_bytes);
|
|
if (!d->eb_data)
|
|
goto eb_data_fail;
|
|
|
|
for (i = 0; i < pages; i++)
|
|
d->page_data[i] = BLOCK_UNDEF;
|
|
|
|
for (i = 0; i < blocks; i++)
|
|
d->revmap[i] = PAGE_UNDEF;
|
|
|
|
d->page_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
|
|
if (!d->page_buf)
|
|
goto page_buf_fail;
|
|
|
|
d->oob_buf = kmalloc(2 * mtd->oobavail, GFP_KERNEL);
|
|
if (!d->oob_buf)
|
|
goto oob_buf_fail;
|
|
|
|
mtdswap_scan_eblks(d);
|
|
|
|
return 0;
|
|
|
|
oob_buf_fail:
|
|
kfree(d->page_buf);
|
|
page_buf_fail:
|
|
vfree(d->eb_data);
|
|
eb_data_fail:
|
|
vfree(d->revmap);
|
|
revmap_fail:
|
|
vfree(d->page_data);
|
|
page_data_fail:
|
|
printk(KERN_ERR "%s: init failed (%d)\n", MTDSWAP_PREFIX, ret);
|
|
return ret;
|
|
}
|
|
|
|
static void mtdswap_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
|
|
{
|
|
struct mtdswap_dev *d;
|
|
struct mtd_blktrans_dev *mbd_dev;
|
|
char *parts;
|
|
char *this_opt;
|
|
unsigned long part;
|
|
unsigned int eblocks, eavailable, bad_blocks, spare_cnt;
|
|
uint64_t swap_size, use_size, size_limit;
|
|
int ret;
|
|
|
|
parts = &partitions[0];
|
|
if (!*parts)
|
|
return;
|
|
|
|
while ((this_opt = strsep(&parts, ",")) != NULL) {
|
|
if (kstrtoul(this_opt, 0, &part) < 0)
|
|
return;
|
|
|
|
if (mtd->index == part)
|
|
break;
|
|
}
|
|
|
|
if (mtd->index != part)
|
|
return;
|
|
|
|
if (mtd->erasesize < PAGE_SIZE || mtd->erasesize % PAGE_SIZE) {
|
|
printk(KERN_ERR "%s: Erase size %u not multiple of PAGE_SIZE "
|
|
"%lu\n", MTDSWAP_PREFIX, mtd->erasesize, PAGE_SIZE);
|
|
return;
|
|
}
|
|
|
|
if (PAGE_SIZE % mtd->writesize || mtd->writesize > PAGE_SIZE) {
|
|
printk(KERN_ERR "%s: PAGE_SIZE %lu not multiple of write size"
|
|
" %u\n", MTDSWAP_PREFIX, PAGE_SIZE, mtd->writesize);
|
|
return;
|
|
}
|
|
|
|
if (!mtd->oobsize || mtd->oobavail < MTDSWAP_OOBSIZE) {
|
|
printk(KERN_ERR "%s: Not enough free bytes in OOB, "
|
|
"%d available, %zu needed.\n",
|
|
MTDSWAP_PREFIX, mtd->oobavail, MTDSWAP_OOBSIZE);
|
|
return;
|
|
}
|
|
|
|
if (spare_eblocks > 100)
|
|
spare_eblocks = 100;
|
|
|
|
use_size = mtd->size;
|
|
size_limit = (uint64_t) BLOCK_MAX * PAGE_SIZE;
|
|
|
|
if (mtd->size > size_limit) {
|
|
printk(KERN_WARNING "%s: Device too large. Limiting size to "
|
|
"%llu bytes\n", MTDSWAP_PREFIX, size_limit);
|
|
use_size = size_limit;
|
|
}
|
|
|
|
eblocks = mtd_div_by_eb(use_size, mtd);
|
|
use_size = (uint64_t)eblocks * mtd->erasesize;
|
|
bad_blocks = mtdswap_badblocks(mtd, use_size);
|
|
eavailable = eblocks - bad_blocks;
|
|
|
|
if (eavailable < MIN_ERASE_BLOCKS) {
|
|
printk(KERN_ERR "%s: Not enough erase blocks. %u available, "
|
|
"%d needed\n", MTDSWAP_PREFIX, eavailable,
|
|
MIN_ERASE_BLOCKS);
|
|
return;
|
|
}
|
|
|
|
spare_cnt = div_u64((uint64_t)eavailable * spare_eblocks, 100);
|
|
|
|
if (spare_cnt < MIN_SPARE_EBLOCKS)
|
|
spare_cnt = MIN_SPARE_EBLOCKS;
|
|
|
|
if (spare_cnt > eavailable - 1)
|
|
spare_cnt = eavailable - 1;
|
|
|
|
swap_size = (uint64_t)(eavailable - spare_cnt) * mtd->erasesize +
|
|
(header ? PAGE_SIZE : 0);
|
|
|
|
printk(KERN_INFO "%s: Enabling MTD swap on device %lu, size %llu KB, "
|
|
"%u spare, %u bad blocks\n",
|
|
MTDSWAP_PREFIX, part, swap_size / 1024, spare_cnt, bad_blocks);
|
|
|
|
d = kzalloc(sizeof(struct mtdswap_dev), GFP_KERNEL);
|
|
if (!d)
|
|
return;
|
|
|
|
mbd_dev = kzalloc(sizeof(struct mtd_blktrans_dev), GFP_KERNEL);
|
|
if (!mbd_dev) {
|
|
kfree(d);
|
|
return;
|
|
}
|
|
|
|
d->mbd_dev = mbd_dev;
|
|
mbd_dev->priv = d;
|
|
|
|
mbd_dev->mtd = mtd;
|
|
mbd_dev->devnum = mtd->index;
|
|
mbd_dev->size = swap_size >> PAGE_SHIFT;
|
|
mbd_dev->tr = tr;
|
|
|
|
if (!(mtd->flags & MTD_WRITEABLE))
|
|
mbd_dev->readonly = 1;
|
|
|
|
if (mtdswap_init(d, eblocks, spare_cnt) < 0)
|
|
goto init_failed;
|
|
|
|
if (add_mtd_blktrans_dev(mbd_dev) < 0)
|
|
goto cleanup;
|
|
|
|
d->dev = disk_to_dev(mbd_dev->disk);
|
|
|
|
ret = mtdswap_add_debugfs(d);
|
|
if (ret < 0)
|
|
goto debugfs_failed;
|
|
|
|
return;
|
|
|
|
debugfs_failed:
|
|
del_mtd_blktrans_dev(mbd_dev);
|
|
|
|
cleanup:
|
|
mtdswap_cleanup(d);
|
|
|
|
init_failed:
|
|
kfree(mbd_dev);
|
|
kfree(d);
|
|
}
|
|
|
|
static void mtdswap_remove_dev(struct mtd_blktrans_dev *dev)
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{
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struct mtdswap_dev *d = MTDSWAP_MBD_TO_MTDSWAP(dev);
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|
|
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del_mtd_blktrans_dev(dev);
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|
mtdswap_cleanup(d);
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|
kfree(d);
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|
}
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|
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static struct mtd_blktrans_ops mtdswap_ops = {
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.name = "mtdswap",
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|
.major = 0,
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|
.part_bits = 0,
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|
.blksize = PAGE_SIZE,
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|
.flush = mtdswap_flush,
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|
.readsect = mtdswap_readsect,
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|
.writesect = mtdswap_writesect,
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|
.discard = mtdswap_discard,
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|
.background = mtdswap_background,
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|
.add_mtd = mtdswap_add_mtd,
|
|
.remove_dev = mtdswap_remove_dev,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int __init mtdswap_modinit(void)
|
|
{
|
|
return register_mtd_blktrans(&mtdswap_ops);
|
|
}
|
|
|
|
static void __exit mtdswap_modexit(void)
|
|
{
|
|
deregister_mtd_blktrans(&mtdswap_ops);
|
|
}
|
|
|
|
module_init(mtdswap_modinit);
|
|
module_exit(mtdswap_modexit);
|
|
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Jarkko Lavinen <jarkko.lavinen@nokia.com>");
|
|
MODULE_DESCRIPTION("Block device access to an MTD suitable for using as "
|
|
"swap space");
|