erase.c

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/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2007 Red Hat, Inc.
 * Copyright © 2004-2010 David Woodhouse <[email protected]>
 *
 * Created by David Woodhouse <[email protected]>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/compiler.h>
#include <linux/crc32.h>
#include <linux/sched.h>
#include <linux/pagemap.h>
#include "nodelist.h"

struct erase_priv_struct {
    struct jffs2_eraseblock *jeb;
    struct jffs2_sb_info *c;
};

#ifndef __ECOS
static void jffs2_erase_callback(struct erase_info *);
#endif
static void jffs2_erase_failed(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, uint32_t bad_offset);
static void jffs2_erase_succeeded(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
static void jffs2_mark_erased_block(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);

static void jffs2_erase_block(struct jffs2_sb_info *c,
                  struct jffs2_eraseblock *jeb)
{
    int ret;
    uint32_t bad_offset;
#ifdef __ECOS
       ret = jffs2_flash_erase(c, jeb);
       if (!ret) {
           jffs2_erase_succeeded(c, jeb);
           return;
       }
       bad_offset = jeb->offset;
#else /* Linux */
    struct erase_info *instr;

    jffs2_dbg(1, "%s(): erase block %#08x (range %#08x-%#08x)\n",
          __func__,
          jeb->offset, jeb->offset, jeb->offset + c->sector_size);
    instr = kmalloc(sizeof(struct erase_info) + sizeof(struct erase_priv_struct), GFP_KERNEL);
    if (!instr) {
        pr_warn("kmalloc for struct erase_info in jffs2_erase_block failed. Refiling block for later\n");
        mutex_lock(&c->erase_free_sem);
        spin_lock(&c->erase_completion_lock);
        list_move(&jeb->list, &c->erase_pending_list);
        c->erasing_size -= c->sector_size;
        c->dirty_size += c->sector_size;
        jeb->dirty_size = c->sector_size;
        spin_unlock(&c->erase_completion_lock);
        mutex_unlock(&c->erase_free_sem);
        return;
    }

    memset(instr, 0, sizeof(*instr));

    instr->mtd = c->mtd;
    instr->addr = jeb->offset;
    instr->len = c->sector_size;
    instr->callback = jffs2_erase_callback;
    instr->priv = (unsigned long)(&instr[1]);

    ((struct erase_priv_struct *)instr->priv)->jeb = jeb;
    ((struct erase_priv_struct *)instr->priv)->c = c;

    ret = mtd_erase(c->mtd, instr);
    if (!ret)
        return;

    bad_offset = instr->fail_addr;
    kfree(instr);
#endif /* __ECOS */

    if (ret == -ENOMEM || ret == -EAGAIN) {
        /* Erase failed immediately. Refile it on the list */
        jffs2_dbg(1, "Erase at 0x%08x failed: %d. Refiling on erase_pending_list\n",
              jeb->offset, ret);
        mutex_lock(&c->erase_free_sem);
        spin_lock(&c->erase_completion_lock);
        list_move(&jeb->list, &c->erase_pending_list);
        c->erasing_size -= c->sector_size;
        c->dirty_size += c->sector_size;
        jeb->dirty_size = c->sector_size;
        spin_unlock(&c->erase_completion_lock);
        mutex_unlock(&c->erase_free_sem);
        return;
    }

    if (ret == -EROFS)
        pr_warn("Erase at 0x%08x failed immediately: -EROFS. Is the sector locked?\n",
            jeb->offset);
    else
        pr_warn("Erase at 0x%08x failed immediately: errno %d\n",
            jeb->offset, ret);

    jffs2_erase_failed(c, jeb, bad_offset);
}

int jffs2_erase_pending_blocks(struct jffs2_sb_info *c, int count)
{
    struct jffs2_eraseblock *jeb;
    int work_done = 0;

    mutex_lock(&c->erase_free_sem);

    spin_lock(&c->erase_completion_lock);

    while (!list_empty(&c->erase_complete_list) ||
           !list_empty(&c->erase_pending_list)) {

        if (!list_empty(&c->erase_complete_list)) {
            jeb = list_entry(c->erase_complete_list.next, struct jffs2_eraseblock, list);
            list_move(&jeb->list, &c->erase_checking_list);
            spin_unlock(&c->erase_completion_lock);
            mutex_unlock(&c->erase_free_sem);
            jffs2_mark_erased_block(c, jeb);

            work_done++;
            if (!--count) {
                jffs2_dbg(1, "Count reached. jffs2_erase_pending_blocks leaving\n");
                goto done;
            }

        } else if (!list_empty(&c->erase_pending_list)) {
            jeb = list_entry(c->erase_pending_list.next, struct jffs2_eraseblock, list);
            jffs2_dbg(1, "Starting erase of pending block 0x%08x\n",
                  jeb->offset);
            list_del(&jeb->list);
            c->erasing_size += c->sector_size;
            c->wasted_size -= jeb->wasted_size;
            c->free_size -= jeb->free_size;
            c->used_size -= jeb->used_size;
            c->dirty_size -= jeb->dirty_size;
            jeb->wasted_size = jeb->used_size = jeb->dirty_size = jeb->free_size = 0;
            jffs2_free_jeb_node_refs(c, jeb);
            list_add(&jeb->list, &c->erasing_list);
            spin_unlock(&c->erase_completion_lock);
            mutex_unlock(&c->erase_free_sem);

            jffs2_erase_block(c, jeb);

        } else {
            BUG();
        }

        /* Be nice */
        cond_resched();
        mutex_lock(&c->erase_free_sem);
        spin_lock(&c->erase_completion_lock);
    }

    spin_unlock(&c->erase_completion_lock);
    mutex_unlock(&c->erase_free_sem);
 done:
    jffs2_dbg(1, "jffs2_erase_pending_blocks completed\n");
    return work_done;
}

static void jffs2_erase_succeeded(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
{
    jffs2_dbg(1, "Erase completed successfully at 0x%08x\n", jeb->offset);
    mutex_lock(&c->erase_free_sem);
    spin_lock(&c->erase_completion_lock);
    list_move_tail(&jeb->list, &c->erase_complete_list);
    /* Wake the GC thread to mark them clean */
    jffs2_garbage_collect_trigger(c);
    spin_unlock(&c->erase_completion_lock);
    mutex_unlock(&c->erase_free_sem);
    wake_up(&c->erase_wait);
}

static void jffs2_erase_failed(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, uint32_t bad_offset)
{
    /* For NAND, if the failure did not occur at the device level for a
       specific physical page, don't bother updating the bad block table. */
    if (jffs2_cleanmarker_oob(c) && (bad_offset != (uint32_t)MTD_FAIL_ADDR_UNKNOWN)) {
        /* We had a device-level failure to erase.  Let's see if we've
           failed too many times. */
        if (!jffs2_write_nand_badblock(c, jeb, bad_offset)) {
            /* We'd like to give this block another try. */
            mutex_lock(&c->erase_free_sem);
            spin_lock(&c->erase_completion_lock);
            list_move(&jeb->list, &c->erase_pending_list);
            c->erasing_size -= c->sector_size;
            c->dirty_size += c->sector_size;
            jeb->dirty_size = c->sector_size;
            spin_unlock(&c->erase_completion_lock);
            mutex_unlock(&c->erase_free_sem);
            return;
        }
    }

    mutex_lock(&c->erase_free_sem);
    spin_lock(&c->erase_completion_lock);
    c->erasing_size -= c->sector_size;
    c->bad_size += c->sector_size;
    list_move(&jeb->list, &c->bad_list);
    c->nr_erasing_blocks--;
    spin_unlock(&c->erase_completion_lock);
    mutex_unlock(&c->erase_free_sem);
    wake_up(&c->erase_wait);
}

#ifndef __ECOS
static void jffs2_erase_callback(struct erase_info *instr)
{
    struct erase_priv_struct *priv = (void *)instr->priv;

    if(instr->state != MTD_ERASE_DONE) {
        pr_warn("Erase at 0x%08llx finished, but state != MTD_ERASE_DONE. State is 0x%x instead.\n",
            (unsigned long long)instr->addr, instr->state);
        jffs2_erase_failed(priv->c, priv->jeb, instr->fail_addr);
    } else {
        jffs2_erase_succeeded(priv->c, priv->jeb);
    }
    kfree(instr);
}
#endif /* !__ECOS */

/* Hmmm. Maybe we should accept the extra space it takes and make
   this a standard doubly-linked list? */
static inline void jffs2_remove_node_refs_from_ino_list(struct jffs2_sb_info *c,
            struct jffs2_raw_node_ref *ref, struct jffs2_eraseblock *jeb)
{
    struct jffs2_inode_cache *ic = NULL;
    struct jffs2_raw_node_ref **prev;

    prev = &ref->next_in_ino;

    /* Walk the inode's list once, removing any nodes from this eraseblock */
    while (1) {
        if (!(*prev)->next_in_ino) {
            /* We're looking at the jffs2_inode_cache, which is
               at the end of the linked list. Stash it and continue
               from the beginning of the list */
            ic = (struct jffs2_inode_cache *)(*prev);
            prev = &ic->nodes;
            continue;
        }

        if (SECTOR_ADDR((*prev)->flash_offset) == jeb->offset) {
            /* It's in the block we're erasing */
            struct jffs2_raw_node_ref *this;

            this = *prev;
            *prev = this->next_in_ino;
            this->next_in_ino = NULL;

            if (this == ref)
                break;

            continue;
        }
        /* Not to be deleted. Skip */
        prev = &((*prev)->next_in_ino);
    }

    /* PARANOIA */
    if (!ic) {
        JFFS2_WARNING("inode_cache/xattr_datum/xattr_ref"
                  " not found in remove_node_refs()!!\n");
        return;
    }

    jffs2_dbg(1, "Removed nodes in range 0x%08x-0x%08x from ino #%u\n",
          jeb->offset, jeb->offset + c->sector_size, ic->ino);

    D2({
        int i=0;
        struct jffs2_raw_node_ref *this;
        printk(KERN_DEBUG "After remove_node_refs_from_ino_list: \n");

        this = ic->nodes;

        printk(KERN_DEBUG);
        while(this) {
            pr_cont("0x%08x(%d)->",
                   ref_offset(this), ref_flags(this));
            if (++i == 5) {
                printk(KERN_DEBUG);
                i=0;
            }
            this = this->next_in_ino;
        }
        pr_cont("\n");
    });

    switch (ic->class) {
#ifdef CONFIG_JFFS2_FS_XATTR
        case RAWNODE_CLASS_XATTR_DATUM:
            jffs2_release_xattr_datum(c, (struct jffs2_xattr_datum *)ic);
            break;
        case RAWNODE_CLASS_XATTR_REF:
            jffs2_release_xattr_ref(c, (struct jffs2_xattr_ref *)ic);
            break;
#endif
        default:
            if (ic->nodes == (void *)ic && ic->pino_nlink == 0)
                jffs2_del_ino_cache(c, ic);
    }
}

void jffs2_free_jeb_node_refs(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
{
    struct jffs2_raw_node_ref *block, *ref;
    jffs2_dbg(1, "Freeing all node refs for eraseblock offset 0x%08x\n",
          jeb->offset);

    block = ref = jeb->first_node;

    while (ref) {
        if (ref->flash_offset == REF_LINK_NODE) {
            ref = ref->next_in_ino;
            jffs2_free_refblock(block);
            block = ref;
            continue;
        }
        if (ref->flash_offset != REF_EMPTY_NODE && ref->next_in_ino)
            jffs2_remove_node_refs_from_ino_list(c, ref, jeb);
        /* else it was a non-inode node or already removed, so don't bother */

        ref++;
    }
    jeb->first_node = jeb->last_node = NULL;
}

static int jffs2_block_check_erase(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, uint32_t *bad_offset)
{
    void *ebuf;
    uint32_t ofs;
    size_t retlen;
    int ret;
    unsigned long *wordebuf;

    ret = mtd_point(c->mtd, jeb->offset, c->sector_size, &retlen,
            &ebuf, NULL);
    if (ret != -EOPNOTSUPP) {
        if (ret) {
            jffs2_dbg(1, "MTD point failed %d\n", ret);
            goto do_flash_read;
        }
        if (retlen < c->sector_size) {
            /* Don't muck about if it won't let us point to the whole erase sector */
            jffs2_dbg(1, "MTD point returned len too short: 0x%zx\n",
                  retlen);
            mtd_unpoint(c->mtd, jeb->offset, retlen);
            goto do_flash_read;
        }
        wordebuf = ebuf-sizeof(*wordebuf);
        retlen /= sizeof(*wordebuf);
        do {
           if (*++wordebuf != ~0)
               break;
        } while(--retlen);
        mtd_unpoint(c->mtd, jeb->offset, c->sector_size);
        if (retlen) {
            pr_warn("Newly-erased block contained word 0x%lx at offset 0x%08tx\n",
                *wordebuf,
                jeb->offset +
                c->sector_size-retlen * sizeof(*wordebuf));
            return -EIO;
        }
        return 0;
    }
 do_flash_read:
    ebuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
    if (!ebuf) {
        pr_warn("Failed to allocate page buffer for verifying erase at 0x%08x. Refiling\n",
            jeb->offset);
        return -EAGAIN;
    }

    jffs2_dbg(1, "Verifying erase at 0x%08x\n", jeb->offset);

    for (ofs = jeb->offset; ofs < jeb->offset + c->sector_size; ) {
        uint32_t readlen = min((uint32_t)PAGE_SIZE, jeb->offset + c->sector_size - ofs);
        int i;

        *bad_offset = ofs;

        ret = mtd_read(c->mtd, ofs, readlen, &retlen, ebuf);
        if (ret) {
            pr_warn("Read of newly-erased block at 0x%08x failed: %d. Putting on bad_list\n",
                ofs, ret);
            ret = -EIO;
            goto fail;
        }
        if (retlen != readlen) {
            pr_warn("Short read from newly-erased block at 0x%08x. Wanted %d, got %zd\n",
                ofs, readlen, retlen);
            ret = -EIO;
            goto fail;
        }
        for (i=0; i<readlen; i += sizeof(unsigned long)) {
            /* It's OK. We know it's properly aligned */
            unsigned long *datum = ebuf + i;
            if (*datum + 1) {
                *bad_offset += i;
                pr_warn("Newly-erased block contained word 0x%lx at offset 0x%08x\n",
                    *datum, *bad_offset);
                ret = -EIO;
                goto fail;
            }
        }
        ofs += readlen;
        cond_resched();
    }
    ret = 0;
fail:
    kfree(ebuf);
    return ret;
}

static void jffs2_mark_erased_block(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
{
    size_t retlen;
    int ret;
    uint32_t uninitialized_var(bad_offset);

    switch (jffs2_block_check_erase(c, jeb, &bad_offset)) {
    case -EAGAIN:   goto refile;
    case -EIO:  goto filebad;
    }

    /* Write the erase complete marker */
    jffs2_dbg(1, "Writing erased marker to block at 0x%08x\n", jeb->offset);
    bad_offset = jeb->offset;

    /* Cleanmarker in oob area or no cleanmarker at all ? */
    if (jffs2_cleanmarker_oob(c) || c->cleanmarker_size == 0) {

        if (jffs2_cleanmarker_oob(c)) {
            if (jffs2_write_nand_cleanmarker(c, jeb))
                goto filebad;
        }
    } else {

        struct kvec vecs[1];
        struct jffs2_unknown_node marker = {
            .magic =    cpu_to_je16(JFFS2_MAGIC_BITMASK),
            .nodetype = cpu_to_je16(JFFS2_NODETYPE_CLEANMARKER),
            .totlen =   cpu_to_je32(c->cleanmarker_size)
        };

        jffs2_prealloc_raw_node_refs(c, jeb, 1);

        marker.hdr_crc = cpu_to_je32(crc32(0, &marker, sizeof(struct jffs2_unknown_node)-4));

        vecs[0].iov_base = (unsigned char *) &marker;
        vecs[0].iov_len = sizeof(marker);
        ret = jffs2_flash_direct_writev(c, vecs, 1, jeb->offset, &retlen);

        if (ret || retlen != sizeof(marker)) {
            if (ret)
                pr_warn("Write clean marker to block at 0x%08x failed: %d\n",
                       jeb->offset, ret);
            else
                pr_warn("Short write to newly-erased block at 0x%08x: Wanted %zd, got %zd\n",
                       jeb->offset, sizeof(marker), retlen);

            goto filebad;
        }
    }
    /* Everything else got zeroed before the erase */
    jeb->free_size = c->sector_size;

    mutex_lock(&c->erase_free_sem);
    spin_lock(&c->erase_completion_lock);

    c->erasing_size -= c->sector_size;
    c->free_size += c->sector_size;

    /* Account for cleanmarker now, if it's in-band */
    if (c->cleanmarker_size && !jffs2_cleanmarker_oob(c))
        jffs2_link_node_ref(c, jeb, jeb->offset | REF_NORMAL, c->cleanmarker_size, NULL);

    list_move_tail(&jeb->list, &c->free_list);
    c->nr_erasing_blocks--;
    c->nr_free_blocks++;

    jffs2_dbg_acct_sanity_check_nolock(c, jeb);
    jffs2_dbg_acct_paranoia_check_nolock(c, jeb);

    spin_unlock(&c->erase_completion_lock);
    mutex_unlock(&c->erase_free_sem);
    wake_up(&c->erase_wait);
    return;

filebad:
    jffs2_erase_failed(c, jeb, bad_offset);
    return;

refile:
    /* Stick it back on the list from whence it came and come back later */
    mutex_lock(&c->erase_free_sem);
    spin_lock(&c->erase_completion_lock);
    jffs2_garbage_collect_trigger(c);
    list_move(&jeb->list, &c->erase_complete_list);
    spin_unlock(&c->erase_completion_lock);
    mutex_unlock(&c->erase_free_sem);
    return;
}