anode.c

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/*
 *  linux/fs/hpfs/anode.c
 *
 *  Mikulas Patocka ([email protected]), 1998-1999
 *
 *  handling HPFS anode tree that contains file allocation info
 */

#include "hpfs_fn.h"

/* Find a sector in allocation tree */

secno hpfs_bplus_lookup(struct super_block *s, struct inode *inode,
           struct bplus_header *btree, unsigned sec,
           struct buffer_head *bh)
{
    anode_secno a = -1;
    struct anode *anode;
    int i;
    int c1, c2 = 0;
    go_down:
    if (hpfs_sb(s)->sb_chk) if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_bplus_lookup")) return -1;
    if (bp_internal(btree)) {
        for (i = 0; i < btree->n_used_nodes; i++)
            if (le32_to_cpu(btree->u.internal[i].file_secno) > sec) {
                a = le32_to_cpu(btree->u.internal[i].down);
                brelse(bh);
                if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
                btree = &anode->btree;
                goto go_down;
            }
        hpfs_error(s, "sector %08x not found in internal anode %08x", sec, a);
        brelse(bh);
        return -1;
    }
    for (i = 0; i < btree->n_used_nodes; i++)
        if (le32_to_cpu(btree->u.external[i].file_secno) <= sec &&
            le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > sec) {
            a = le32_to_cpu(btree->u.external[i].disk_secno) + sec - le32_to_cpu(btree->u.external[i].file_secno);
            if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, a, 1, "data")) {
                brelse(bh);
                return -1;
            }
            if (inode) {
                struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
                hpfs_inode->i_file_sec = le32_to_cpu(btree->u.external[i].file_secno);
                hpfs_inode->i_disk_sec = le32_to_cpu(btree->u.external[i].disk_secno);
                hpfs_inode->i_n_secs = le32_to_cpu(btree->u.external[i].length);
            }
            brelse(bh);
            return a;
        }
    hpfs_error(s, "sector %08x not found in external anode %08x", sec, a);
    brelse(bh);
    return -1;
}

/* Add a sector to tree */

secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsigned fsecno)
{
    struct bplus_header *btree;
    struct anode *anode = NULL, *ranode = NULL;
    struct fnode *fnode;
    anode_secno a, na = -1, ra, up = -1;
    secno se;
    struct buffer_head *bh, *bh1, *bh2;
    int n;
    unsigned fs;
    int c1, c2 = 0;
    if (fnod) {
        if (!(fnode = hpfs_map_fnode(s, node, &bh))) return -1;
        btree = &fnode->btree;
    } else {
        if (!(anode = hpfs_map_anode(s, node, &bh))) return -1;
        btree = &anode->btree;
    }
    a = node;
    go_down:
    if ((n = btree->n_used_nodes - 1) < -!!fnod) {
        hpfs_error(s, "anode %08x has no entries", a);
        brelse(bh);
        return -1;
    }
    if (bp_internal(btree)) {
        a = le32_to_cpu(btree->u.internal[n].down);
        btree->u.internal[n].file_secno = cpu_to_le32(-1);
        mark_buffer_dirty(bh);
        brelse(bh);
        if (hpfs_sb(s)->sb_chk)
            if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_add_sector_to_btree #1")) return -1;
        if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
        btree = &anode->btree;
        goto go_down;
    }
    if (n >= 0) {
        if (le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length) != fsecno) {
            hpfs_error(s, "allocated size %08x, trying to add sector %08x, %cnode %08x",
                le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length), fsecno,
                fnod?'f':'a', node);
            brelse(bh);
            return -1;
        }
        if (hpfs_alloc_if_possible(s, se = le32_to_cpu(btree->u.external[n].disk_secno) + le32_to_cpu(btree->u.external[n].length))) {
            le32_add_cpu(&btree->u.external[n].length, 1);
            mark_buffer_dirty(bh);
            brelse(bh);
            return se;
        }
    } else {
        if (fsecno) {
            hpfs_error(s, "empty file %08x, trying to add sector %08x", node, fsecno);
            brelse(bh);
            return -1;
        }
        se = !fnod ? node : (node + 16384) & ~16383;
    }   
    if (!(se = hpfs_alloc_sector(s, se, 1, fsecno*ALLOC_M>ALLOC_FWD_MAX ? ALLOC_FWD_MAX : fsecno*ALLOC_M<ALLOC_FWD_MIN ? ALLOC_FWD_MIN : fsecno*ALLOC_M))) {
        brelse(bh);
        return -1;
    }
    fs = n < 0 ? 0 : le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length);
    if (!btree->n_free_nodes) {
        up = a != node ? le32_to_cpu(anode->up) : -1;
        if (!(anode = hpfs_alloc_anode(s, a, &na, &bh1))) {
            brelse(bh);
            hpfs_free_sectors(s, se, 1);
            return -1;
        }
        if (a == node && fnod) {
            anode->up = cpu_to_le32(node);
            anode->btree.flags |= BP_fnode_parent;
            anode->btree.n_used_nodes = btree->n_used_nodes;
            anode->btree.first_free = btree->first_free;
            anode->btree.n_free_nodes = 40 - anode->btree.n_used_nodes;
            memcpy(&anode->u, &btree->u, btree->n_used_nodes * 12);
            btree->flags |= BP_internal;
            btree->n_free_nodes = 11;
            btree->n_used_nodes = 1;
            btree->first_free = cpu_to_le16((char *)&(btree->u.internal[1]) - (char *)btree);
            btree->u.internal[0].file_secno = cpu_to_le32(-1);
            btree->u.internal[0].down = cpu_to_le32(na);
            mark_buffer_dirty(bh);
        } else if (!(ranode = hpfs_alloc_anode(s, /*a*/0, &ra, &bh2))) {
            brelse(bh);
            brelse(bh1);
            hpfs_free_sectors(s, se, 1);
            hpfs_free_sectors(s, na, 1);
            return -1;
        }
        brelse(bh);
        bh = bh1;
        btree = &anode->btree;
    }
    btree->n_free_nodes--; n = btree->n_used_nodes++;
    le16_add_cpu(&btree->first_free, 12);
    btree->u.external[n].disk_secno = cpu_to_le32(se);
    btree->u.external[n].file_secno = cpu_to_le32(fs);
    btree->u.external[n].length = cpu_to_le32(1);
    mark_buffer_dirty(bh);
    brelse(bh);
    if ((a == node && fnod) || na == -1) return se;
    c2 = 0;
    while (up != (anode_secno)-1) {
        struct anode *new_anode;
        if (hpfs_sb(s)->sb_chk)
            if (hpfs_stop_cycles(s, up, &c1, &c2, "hpfs_add_sector_to_btree #2")) return -1;
        if (up != node || !fnod) {
            if (!(anode = hpfs_map_anode(s, up, &bh))) return -1;
            btree = &anode->btree;
        } else {
            if (!(fnode = hpfs_map_fnode(s, up, &bh))) return -1;
            btree = &fnode->btree;
        }
        if (btree->n_free_nodes) {
            btree->n_free_nodes--; n = btree->n_used_nodes++;
            le16_add_cpu(&btree->first_free, 8);
            btree->u.internal[n].file_secno = cpu_to_le32(-1);
            btree->u.internal[n].down = cpu_to_le32(na);
            btree->u.internal[n-1].file_secno = cpu_to_le32(fs);
            mark_buffer_dirty(bh);
            brelse(bh);
            brelse(bh2);
            hpfs_free_sectors(s, ra, 1);
            if ((anode = hpfs_map_anode(s, na, &bh))) {
                anode->up = cpu_to_le32(up);
                if (up == node && fnod)
                    anode->btree.flags |= BP_fnode_parent;
                else
                    anode->btree.flags &= ~BP_fnode_parent;
                mark_buffer_dirty(bh);
                brelse(bh);
            }
            return se;
        }
        up = up != node ? le32_to_cpu(anode->up) : -1;
        btree->u.internal[btree->n_used_nodes - 1].file_secno = cpu_to_le32(/*fs*/-1);
        mark_buffer_dirty(bh);
        brelse(bh);
        a = na;
        if ((new_anode = hpfs_alloc_anode(s, a, &na, &bh))) {
            anode = new_anode;
            /*anode->up = cpu_to_le32(up != -1 ? up : ra);*/
            anode->btree.flags |= BP_internal;
            anode->btree.n_used_nodes = 1;
            anode->btree.n_free_nodes = 59;
            anode->btree.first_free = cpu_to_le16(16);
            anode->btree.u.internal[0].down = cpu_to_le32(a);
            anode->btree.u.internal[0].file_secno = cpu_to_le32(-1);
            mark_buffer_dirty(bh);
            brelse(bh);
            if ((anode = hpfs_map_anode(s, a, &bh))) {
                anode->up = cpu_to_le32(na);
                mark_buffer_dirty(bh);
                brelse(bh);
            }
        } else na = a;
    }
    if ((anode = hpfs_map_anode(s, na, &bh))) {
        anode->up = cpu_to_le32(node);
        if (fnod)
            anode->btree.flags |= BP_fnode_parent;
        mark_buffer_dirty(bh);
        brelse(bh);
    }
    if (!fnod) {
        if (!(anode = hpfs_map_anode(s, node, &bh))) {
            brelse(bh2);
            return -1;
        }
        btree = &anode->btree;
    } else {
        if (!(fnode = hpfs_map_fnode(s, node, &bh))) {
            brelse(bh2);
            return -1;
        }
        btree = &fnode->btree;
    }
    ranode->up = cpu_to_le32(node);
    memcpy(&ranode->btree, btree, le16_to_cpu(btree->first_free));
    if (fnod)
        ranode->btree.flags |= BP_fnode_parent;
    ranode->btree.n_free_nodes = (bp_internal(&ranode->btree) ? 60 : 40) - ranode->btree.n_used_nodes;
    if (bp_internal(&ranode->btree)) for (n = 0; n < ranode->btree.n_used_nodes; n++) {
        struct anode *unode;
        if ((unode = hpfs_map_anode(s, le32_to_cpu(ranode->u.internal[n].down), &bh1))) {
            unode->up = cpu_to_le32(ra);
            unode->btree.flags &= ~BP_fnode_parent;
            mark_buffer_dirty(bh1);
            brelse(bh1);
        }
    }
    btree->flags |= BP_internal;
    btree->n_free_nodes = fnod ? 10 : 58;
    btree->n_used_nodes = 2;
    btree->first_free = cpu_to_le16((char *)&btree->u.internal[2] - (char *)btree);
    btree->u.internal[0].file_secno = cpu_to_le32(fs);
    btree->u.internal[0].down = cpu_to_le32(ra);
    btree->u.internal[1].file_secno = cpu_to_le32(-1);
    btree->u.internal[1].down = cpu_to_le32(na);
    mark_buffer_dirty(bh);
    brelse(bh);
    mark_buffer_dirty(bh2);
    brelse(bh2);
    return se;
}

/*
 * Remove allocation tree. Recursion would look much nicer but
 * I want to avoid it because it can cause stack overflow.
 */

void hpfs_remove_btree(struct super_block *s, struct bplus_header *btree)
{
    struct bplus_header *btree1 = btree;
    struct anode *anode = NULL;
    anode_secno ano = 0, oano;
    struct buffer_head *bh;
    int level = 0;
    int pos = 0;
    int i;
    int c1, c2 = 0;
    int d1, d2;
    go_down:
    d2 = 0;
    while (bp_internal(btree1)) {
        ano = le32_to_cpu(btree1->u.internal[pos].down);
        if (level) brelse(bh);
        if (hpfs_sb(s)->sb_chk)
            if (hpfs_stop_cycles(s, ano, &d1, &d2, "hpfs_remove_btree #1"))
                return;
        if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
        btree1 = &anode->btree;
        level++;
        pos = 0;
    }
    for (i = 0; i < btree1->n_used_nodes; i++)
        hpfs_free_sectors(s, le32_to_cpu(btree1->u.external[i].disk_secno), le32_to_cpu(btree1->u.external[i].length));
    go_up:
    if (!level) return;
    brelse(bh);
    if (hpfs_sb(s)->sb_chk)
        if (hpfs_stop_cycles(s, ano, &c1, &c2, "hpfs_remove_btree #2")) return;
    hpfs_free_sectors(s, ano, 1);
    oano = ano;
    ano = le32_to_cpu(anode->up);
    if (--level) {
        if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
        btree1 = &anode->btree;
    } else btree1 = btree;
    for (i = 0; i < btree1->n_used_nodes; i++) {
        if (le32_to_cpu(btree1->u.internal[i].down) == oano) {
            if ((pos = i + 1) < btree1->n_used_nodes)
                goto go_down;
            else
                goto go_up;
        }
    }
    hpfs_error(s,
           "reference to anode %08x not found in anode %08x "
           "(probably bad up pointer)",
           oano, level ? ano : -1);
    if (level)
        brelse(bh);
}

/* Just a wrapper around hpfs_bplus_lookup .. used for reading eas */

static secno anode_lookup(struct super_block *s, anode_secno a, unsigned sec)
{
    struct anode *anode;
    struct buffer_head *bh;
    if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
    return hpfs_bplus_lookup(s, NULL, &anode->btree, sec, bh);
}

int hpfs_ea_read(struct super_block *s, secno a, int ano, unsigned pos,
        unsigned len, char *buf)
{
    struct buffer_head *bh;
    char *data;
    secno sec;
    unsigned l;
    while (len) {
        if (ano) {
            if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
                return -1;
        } else sec = a + (pos >> 9);
        if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #1")) return -1;
        if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
            return -1;
        l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
        memcpy(buf, data + (pos & 0x1ff), l);
        brelse(bh);
        buf += l; pos += l; len -= l;
    }
    return 0;
}

int hpfs_ea_write(struct super_block *s, secno a, int ano, unsigned pos,
         unsigned len, const char *buf)
{
    struct buffer_head *bh;
    char *data;
    secno sec;
    unsigned l;
    while (len) {
        if (ano) {
            if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
                return -1;
        } else sec = a + (pos >> 9);
        if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #2")) return -1;
        if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
            return -1;
        l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
        memcpy(data + (pos & 0x1ff), buf, l);
        mark_buffer_dirty(bh);
        brelse(bh);
        buf += l; pos += l; len -= l;
    }
    return 0;
}

void hpfs_ea_remove(struct super_block *s, secno a, int ano, unsigned len)
{
    struct anode *anode;
    struct buffer_head *bh;
    if (ano) {
        if (!(anode = hpfs_map_anode(s, a, &bh))) return;
        hpfs_remove_btree(s, &anode->btree);
        brelse(bh);
        hpfs_free_sectors(s, a, 1);
    } else hpfs_free_sectors(s, a, (len + 511) >> 9);
}

/* Truncate allocation tree. Doesn't join anodes - I hope it doesn't matter */

void hpfs_truncate_btree(struct super_block *s, secno f, int fno, unsigned secs)
{
    struct fnode *fnode;
    struct anode *anode;
    struct buffer_head *bh;
    struct bplus_header *btree;
    anode_secno node = f;
    int i, j, nodes;
    int c1, c2 = 0;
    if (fno) {
        if (!(fnode = hpfs_map_fnode(s, f, &bh))) return;
        btree = &fnode->btree;
    } else {
        if (!(anode = hpfs_map_anode(s, f, &bh))) return;
        btree = &anode->btree;
    }
    if (!secs) {
        hpfs_remove_btree(s, btree);
        if (fno) {
            btree->n_free_nodes = 8;
            btree->n_used_nodes = 0;
            btree->first_free = cpu_to_le16(8);
            btree->flags &= ~BP_internal;
            mark_buffer_dirty(bh);
        } else hpfs_free_sectors(s, f, 1);
        brelse(bh);
        return;
    }
    while (bp_internal(btree)) {
        nodes = btree->n_used_nodes + btree->n_free_nodes;
        for (i = 0; i < btree->n_used_nodes; i++)
            if (le32_to_cpu(btree->u.internal[i].file_secno) >= secs) goto f;
        brelse(bh);
        hpfs_error(s, "internal btree %08x doesn't end with -1", node);
        return;
        f:
        for (j = i + 1; j < btree->n_used_nodes; j++)
            hpfs_ea_remove(s, le32_to_cpu(btree->u.internal[j].down), 1, 0);
        btree->n_used_nodes = i + 1;
        btree->n_free_nodes = nodes - btree->n_used_nodes;
        btree->first_free = cpu_to_le16(8 + 8 * btree->n_used_nodes);
        mark_buffer_dirty(bh);
        if (btree->u.internal[i].file_secno == cpu_to_le32(secs)) {
            brelse(bh);
            return;
        }
        node = le32_to_cpu(btree->u.internal[i].down);
        brelse(bh);
        if (hpfs_sb(s)->sb_chk)
            if (hpfs_stop_cycles(s, node, &c1, &c2, "hpfs_truncate_btree"))
                return;
        if (!(anode = hpfs_map_anode(s, node, &bh))) return;
        btree = &anode->btree;
    }   
    nodes = btree->n_used_nodes + btree->n_free_nodes;
    for (i = 0; i < btree->n_used_nodes; i++)
        if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) >= secs) goto ff;
    brelse(bh);
    return;
    ff:
    if (secs <= le32_to_cpu(btree->u.external[i].file_secno)) {
        hpfs_error(s, "there is an allocation error in file %08x, sector %08x", f, secs);
        if (i) i--;
    }
    else if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > secs) {
        hpfs_free_sectors(s, le32_to_cpu(btree->u.external[i].disk_secno) + secs -
            le32_to_cpu(btree->u.external[i].file_secno), le32_to_cpu(btree->u.external[i].length)
            - secs + le32_to_cpu(btree->u.external[i].file_secno)); /* I hope gcc optimizes this :-) */
        btree->u.external[i].length = cpu_to_le32(secs - le32_to_cpu(btree->u.external[i].file_secno));
    }
    for (j = i + 1; j < btree->n_used_nodes; j++)
        hpfs_free_sectors(s, le32_to_cpu(btree->u.external[j].disk_secno), le32_to_cpu(btree->u.external[j].length));
    btree->n_used_nodes = i + 1;
    btree->n_free_nodes = nodes - btree->n_used_nodes;
    btree->first_free = cpu_to_le16(8 + 12 * btree->n_used_nodes);
    mark_buffer_dirty(bh);
    brelse(bh);
}

/* Remove file or directory and it's eas - note that directory must
   be empty when this is called. */

void hpfs_remove_fnode(struct super_block *s, fnode_secno fno)
{
    struct buffer_head *bh;
    struct fnode *fnode;
    struct extended_attribute *ea;
    struct extended_attribute *ea_end;
    if (!(fnode = hpfs_map_fnode(s, fno, &bh))) return;
    if (!fnode_is_dir(fnode)) hpfs_remove_btree(s, &fnode->btree);
    else hpfs_remove_dtree(s, le32_to_cpu(fnode->u.external[0].disk_secno));
    ea_end = fnode_end_ea(fnode);
    for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
        if (ea_indirect(ea))
            hpfs_ea_remove(s, ea_sec(ea), ea_in_anode(ea), ea_len(ea));
    hpfs_ea_ext_remove(s, le32_to_cpu(fnode->ea_secno), fnode_in_anode(fnode), le32_to_cpu(fnode->ea_size_l));
    brelse(bh);
    hpfs_free_sectors(s, fno, 1);
}