item_ops.c

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/*
 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
 */

#include <linux/time.h>
#include "reiserfs.h"

// this contains item handlers for old item types: sd, direct,
// indirect, directory

/* and where are the comments? how about saying where we can find an
   explanation of each item handler method? -Hans */

// stat data functions
//
static int sd_bytes_number(struct item_head *ih, int block_size)
{
    return 0;
}

static void sd_decrement_key(struct cpu_key *key)
{
    key->on_disk_key.k_objectid--;
    set_cpu_key_k_type(key, TYPE_ANY);
    set_cpu_key_k_offset(key, (loff_t)(~0ULL >> 1));
}

static int sd_is_left_mergeable(struct reiserfs_key *key, unsigned long bsize)
{
    return 0;
}

static char *print_time(time_t t)
{
    static char timebuf[256];

    sprintf(timebuf, "%ld", t);
    return timebuf;
}

static void sd_print_item(struct item_head *ih, char *item)
{
    printk("\tmode | size | nlinks | first direct | mtime\n");
    if (stat_data_v1(ih)) {
        struct stat_data_v1 *sd = (struct stat_data_v1 *)item;

        printk("\t0%-6o | %6u | %2u | %d | %s\n", sd_v1_mode(sd),
               sd_v1_size(sd), sd_v1_nlink(sd),
               sd_v1_first_direct_byte(sd),
               print_time(sd_v1_mtime(sd)));
    } else {
        struct stat_data *sd = (struct stat_data *)item;

        printk("\t0%-6o | %6Lu | %2u | %d | %s\n", sd_v2_mode(sd),
               (unsigned long long)sd_v2_size(sd), sd_v2_nlink(sd),
               sd_v2_rdev(sd), print_time(sd_v2_mtime(sd)));
    }
}

static void sd_check_item(struct item_head *ih, char *item)
{
    // FIXME: type something here!
}

static int sd_create_vi(struct virtual_node *vn,
            struct virtual_item *vi,
            int is_affected, int insert_size)
{
    vi->vi_index = TYPE_STAT_DATA;
    //vi->vi_type |= VI_TYPE_STAT_DATA;// not needed?
    return 0;
}

static int sd_check_left(struct virtual_item *vi, int free,
             int start_skip, int end_skip)
{
    BUG_ON(start_skip || end_skip);
    return -1;
}

static int sd_check_right(struct virtual_item *vi, int free)
{
    return -1;
}

static int sd_part_size(struct virtual_item *vi, int first, int count)
{
    BUG_ON(count);
    return 0;
}

static int sd_unit_num(struct virtual_item *vi)
{
    return vi->vi_item_len - IH_SIZE;
}

static void sd_print_vi(struct virtual_item *vi)
{
    reiserfs_warning(NULL, "reiserfs-16100",
             "STATDATA, index %d, type 0x%x, %h",
             vi->vi_index, vi->vi_type, vi->vi_ih);
}

static struct item_operations stat_data_ops = {
    .bytes_number = sd_bytes_number,
    .decrement_key = sd_decrement_key,
    .is_left_mergeable = sd_is_left_mergeable,
    .print_item = sd_print_item,
    .check_item = sd_check_item,

    .create_vi = sd_create_vi,
    .check_left = sd_check_left,
    .check_right = sd_check_right,
    .part_size = sd_part_size,
    .unit_num = sd_unit_num,
    .print_vi = sd_print_vi
};

// direct item functions
//
static int direct_bytes_number(struct item_head *ih, int block_size)
{
    return ih_item_len(ih);
}

// FIXME: this should probably switch to indirect as well
static void direct_decrement_key(struct cpu_key *key)
{
    cpu_key_k_offset_dec(key);
    if (cpu_key_k_offset(key) == 0)
        set_cpu_key_k_type(key, TYPE_STAT_DATA);
}

static int direct_is_left_mergeable(struct reiserfs_key *key,
                    unsigned long bsize)
{
    int version = le_key_version(key);
    return ((le_key_k_offset(version, key) & (bsize - 1)) != 1);
}

static void direct_print_item(struct item_head *ih, char *item)
{
    int j = 0;

//    return;
    printk("\"");
    while (j < ih_item_len(ih))
        printk("%c", item[j++]);
    printk("\"\n");
}

static void direct_check_item(struct item_head *ih, char *item)
{
    // FIXME: type something here!
}

static int direct_create_vi(struct virtual_node *vn,
                struct virtual_item *vi,
                int is_affected, int insert_size)
{
    vi->vi_index = TYPE_DIRECT;
    //vi->vi_type |= VI_TYPE_DIRECT;
    return 0;
}

static int direct_check_left(struct virtual_item *vi, int free,
                 int start_skip, int end_skip)
{
    int bytes;

    bytes = free - free % 8;
    return bytes ? : -1;
}

static int direct_check_right(struct virtual_item *vi, int free)
{
    return direct_check_left(vi, free, 0, 0);
}

static int direct_part_size(struct virtual_item *vi, int first, int count)
{
    return count;
}

static int direct_unit_num(struct virtual_item *vi)
{
    return vi->vi_item_len - IH_SIZE;
}

static void direct_print_vi(struct virtual_item *vi)
{
    reiserfs_warning(NULL, "reiserfs-16101",
             "DIRECT, index %d, type 0x%x, %h",
             vi->vi_index, vi->vi_type, vi->vi_ih);
}

static struct item_operations direct_ops = {
    .bytes_number = direct_bytes_number,
    .decrement_key = direct_decrement_key,
    .is_left_mergeable = direct_is_left_mergeable,
    .print_item = direct_print_item,
    .check_item = direct_check_item,

    .create_vi = direct_create_vi,
    .check_left = direct_check_left,
    .check_right = direct_check_right,
    .part_size = direct_part_size,
    .unit_num = direct_unit_num,
    .print_vi = direct_print_vi
};

// indirect item functions
//

static int indirect_bytes_number(struct item_head *ih, int block_size)
{
    return ih_item_len(ih) / UNFM_P_SIZE * block_size;  //- get_ih_free_space (ih);
}

// decrease offset, if it becomes 0, change type to stat data
static void indirect_decrement_key(struct cpu_key *key)
{
    cpu_key_k_offset_dec(key);
    if (cpu_key_k_offset(key) == 0)
        set_cpu_key_k_type(key, TYPE_STAT_DATA);
}

// if it is not first item of the body, then it is mergeable
static int indirect_is_left_mergeable(struct reiserfs_key *key,
                      unsigned long bsize)
{
    int version = le_key_version(key);
    return (le_key_k_offset(version, key) != 1);
}

// printing of indirect item
static void start_new_sequence(__u32 * start, int *len, __u32 new)
{
    *start = new;
    *len = 1;
}

static int sequence_finished(__u32 start, int *len, __u32 new)
{
    if (start == INT_MAX)
        return 1;

    if (start == 0 && new == 0) {
        (*len)++;
        return 0;
    }
    if (start != 0 && (start + *len) == new) {
        (*len)++;
        return 0;
    }
    return 1;
}

static void print_sequence(__u32 start, int len)
{
    if (start == INT_MAX)
        return;

    if (len == 1)
        printk(" %d", start);
    else
        printk(" %d(%d)", start, len);
}

static void indirect_print_item(struct item_head *ih, char *item)
{
    int j;
    __le32 *unp;
    __u32 prev = INT_MAX;
    int num = 0;

    unp = (__le32 *) item;

    if (ih_item_len(ih) % UNFM_P_SIZE)
        reiserfs_warning(NULL, "reiserfs-16102", "invalid item len");

    printk("%d pointers\n[ ", (int)I_UNFM_NUM(ih));
    for (j = 0; j < I_UNFM_NUM(ih); j++) {
        if (sequence_finished(prev, &num, get_block_num(unp, j))) {
            print_sequence(prev, num);
            start_new_sequence(&prev, &num, get_block_num(unp, j));
        }
    }
    print_sequence(prev, num);
    printk("]\n");
}

static void indirect_check_item(struct item_head *ih, char *item)
{
    // FIXME: type something here!
}

static int indirect_create_vi(struct virtual_node *vn,
                  struct virtual_item *vi,
                  int is_affected, int insert_size)
{
    vi->vi_index = TYPE_INDIRECT;
    //vi->vi_type |= VI_TYPE_INDIRECT;
    return 0;
}

static int indirect_check_left(struct virtual_item *vi, int free,
                   int start_skip, int end_skip)
{
    int bytes;

    bytes = free - free % UNFM_P_SIZE;
    return bytes ? : -1;
}

static int indirect_check_right(struct virtual_item *vi, int free)
{
    return indirect_check_left(vi, free, 0, 0);
}

// return size in bytes of 'units' units. If first == 0 - calculate from the head (left), otherwise - from tail (right)
static int indirect_part_size(struct virtual_item *vi, int first, int units)
{
    // unit of indirect item is byte (yet)
    return units;
}

static int indirect_unit_num(struct virtual_item *vi)
{
    // unit of indirect item is byte (yet)
    return vi->vi_item_len - IH_SIZE;
}

static void indirect_print_vi(struct virtual_item *vi)
{
    reiserfs_warning(NULL, "reiserfs-16103",
             "INDIRECT, index %d, type 0x%x, %h",
             vi->vi_index, vi->vi_type, vi->vi_ih);
}

static struct item_operations indirect_ops = {
    .bytes_number = indirect_bytes_number,
    .decrement_key = indirect_decrement_key,
    .is_left_mergeable = indirect_is_left_mergeable,
    .print_item = indirect_print_item,
    .check_item = indirect_check_item,

    .create_vi = indirect_create_vi,
    .check_left = indirect_check_left,
    .check_right = indirect_check_right,
    .part_size = indirect_part_size,
    .unit_num = indirect_unit_num,
    .print_vi = indirect_print_vi
};

// direntry functions
//

static int direntry_bytes_number(struct item_head *ih, int block_size)
{
    reiserfs_warning(NULL, "vs-16090",
             "bytes number is asked for direntry");
    return 0;
}

static void direntry_decrement_key(struct cpu_key *key)
{
    cpu_key_k_offset_dec(key);
    if (cpu_key_k_offset(key) == 0)
        set_cpu_key_k_type(key, TYPE_STAT_DATA);
}

static int direntry_is_left_mergeable(struct reiserfs_key *key,
                      unsigned long bsize)
{
    if (le32_to_cpu(key->u.k_offset_v1.k_offset) == DOT_OFFSET)
        return 0;
    return 1;

}

static void direntry_print_item(struct item_head *ih, char *item)
{
    int i;
    int namelen;
    struct reiserfs_de_head *deh;
    char *name;
    static char namebuf[80];

    printk("\n # %-15s%-30s%-15s%-15s%-15s\n", "Name",
           "Key of pointed object", "Hash", "Gen number", "Status");

    deh = (struct reiserfs_de_head *)item;

    for (i = 0; i < I_ENTRY_COUNT(ih); i++, deh++) {
        namelen =
            (i ? (deh_location(deh - 1)) : ih_item_len(ih)) -
            deh_location(deh);
        name = item + deh_location(deh);
        if (name[namelen - 1] == 0)
            namelen = strlen(name);
        namebuf[0] = '"';
        if (namelen > sizeof(namebuf) - 3) {
            strncpy(namebuf + 1, name, sizeof(namebuf) - 3);
            namebuf[sizeof(namebuf) - 2] = '"';
            namebuf[sizeof(namebuf) - 1] = 0;
        } else {
            memcpy(namebuf + 1, name, namelen);
            namebuf[namelen + 1] = '"';
            namebuf[namelen + 2] = 0;
        }

        printk("%d:  %-15s%-15d%-15d%-15Ld%-15Ld(%s)\n",
               i, namebuf,
               deh_dir_id(deh), deh_objectid(deh),
               GET_HASH_VALUE(deh_offset(deh)),
               GET_GENERATION_NUMBER((deh_offset(deh))),
               (de_hidden(deh)) ? "HIDDEN" : "VISIBLE");
    }
}

static void direntry_check_item(struct item_head *ih, char *item)
{
    int i;
    struct reiserfs_de_head *deh;

    // FIXME: type something here!
    deh = (struct reiserfs_de_head *)item;
    for (i = 0; i < I_ENTRY_COUNT(ih); i++, deh++) {
        ;
    }
}

#define DIRENTRY_VI_FIRST_DIRENTRY_ITEM 1

/*
 * function returns old entry number in directory item in real node
 * using new entry number in virtual item in virtual node */
static inline int old_entry_num(int is_affected, int virtual_entry_num,
                int pos_in_item, int mode)
{
    if (mode == M_INSERT || mode == M_DELETE)
        return virtual_entry_num;

    if (!is_affected)
        /* cut or paste is applied to another item */
        return virtual_entry_num;

    if (virtual_entry_num < pos_in_item)
        return virtual_entry_num;

    if (mode == M_CUT)
        return virtual_entry_num + 1;

    RFALSE(mode != M_PASTE || virtual_entry_num == 0,
           "vs-8015: old_entry_num: mode must be M_PASTE (mode = \'%c\'",
           mode);

    return virtual_entry_num - 1;
}

/* Create an array of sizes of directory entries for virtual
   item. Return space used by an item. FIXME: no control over
   consuming of space used by this item handler */
static int direntry_create_vi(struct virtual_node *vn,
                  struct virtual_item *vi,
                  int is_affected, int insert_size)
{
    struct direntry_uarea *dir_u = vi->vi_uarea;
    int i, j;
    int size = sizeof(struct direntry_uarea);
    struct reiserfs_de_head *deh;

    vi->vi_index = TYPE_DIRENTRY;

    BUG_ON(!(vi->vi_ih) || !vi->vi_item);

    dir_u->flags = 0;
    if (le_ih_k_offset(vi->vi_ih) == DOT_OFFSET)
        dir_u->flags |= DIRENTRY_VI_FIRST_DIRENTRY_ITEM;

    deh = (struct reiserfs_de_head *)(vi->vi_item);

    /* virtual directory item have this amount of entry after */
    dir_u->entry_count = ih_entry_count(vi->vi_ih) +
        ((is_affected) ? ((vn->vn_mode == M_CUT) ? -1 :
                  (vn->vn_mode == M_PASTE ? 1 : 0)) : 0);

    for (i = 0; i < dir_u->entry_count; i++) {
        j = old_entry_num(is_affected, i, vn->vn_pos_in_item,
                  vn->vn_mode);
        dir_u->entry_sizes[i] =
            (j ? deh_location(&(deh[j - 1])) : ih_item_len(vi->vi_ih)) -
            deh_location(&(deh[j])) + DEH_SIZE;
    }

    size += (dir_u->entry_count * sizeof(short));

    /* set size of pasted entry */
    if (is_affected && vn->vn_mode == M_PASTE)
        dir_u->entry_sizes[vn->vn_pos_in_item] = insert_size;

#ifdef CONFIG_REISERFS_CHECK
    /* compare total size of entries with item length */
    {
        int k, l;

        l = 0;
        for (k = 0; k < dir_u->entry_count; k++)
            l += dir_u->entry_sizes[k];

        if (l + IH_SIZE != vi->vi_item_len +
            ((is_affected
              && (vn->vn_mode == M_PASTE
              || vn->vn_mode == M_CUT)) ? insert_size : 0)) {
            reiserfs_panic(NULL, "vs-8025", "(mode==%c, "
                       "insert_size==%d), invalid length of "
                       "directory item",
                       vn->vn_mode, insert_size);
        }
    }
#endif

    return size;

}

//
// return number of entries which may fit into specified amount of
// free space, or -1 if free space is not enough even for 1 entry
//
static int direntry_check_left(struct virtual_item *vi, int free,
                   int start_skip, int end_skip)
{
    int i;
    int entries = 0;
    struct direntry_uarea *dir_u = vi->vi_uarea;

    for (i = start_skip; i < dir_u->entry_count - end_skip; i++) {
        if (dir_u->entry_sizes[i] > free)
            /* i-th entry doesn't fit into the remaining free space */
            break;

        free -= dir_u->entry_sizes[i];
        entries++;
    }

    if (entries == dir_u->entry_count) {
        reiserfs_panic(NULL, "item_ops-1",
                   "free space %d, entry_count %d", free,
                   dir_u->entry_count);
    }

    /* "." and ".." can not be separated from each other */
    if (start_skip == 0 && (dir_u->flags & DIRENTRY_VI_FIRST_DIRENTRY_ITEM)
        && entries < 2)
        entries = 0;

    return entries ? : -1;
}

static int direntry_check_right(struct virtual_item *vi, int free)
{
    int i;
    int entries = 0;
    struct direntry_uarea *dir_u = vi->vi_uarea;

    for (i = dir_u->entry_count - 1; i >= 0; i--) {
        if (dir_u->entry_sizes[i] > free)
            /* i-th entry doesn't fit into the remaining free space */
            break;

        free -= dir_u->entry_sizes[i];
        entries++;
    }
    BUG_ON(entries == dir_u->entry_count);

    /* "." and ".." can not be separated from each other */
    if ((dir_u->flags & DIRENTRY_VI_FIRST_DIRENTRY_ITEM)
        && entries > dir_u->entry_count - 2)
        entries = dir_u->entry_count - 2;

    return entries ? : -1;
}

/* sum of entry sizes between from-th and to-th entries including both edges */
static int direntry_part_size(struct virtual_item *vi, int first, int count)
{
    int i, retval;
    int from, to;
    struct direntry_uarea *dir_u = vi->vi_uarea;

    retval = 0;
    if (first == 0)
        from = 0;
    else
        from = dir_u->entry_count - count;
    to = from + count - 1;

    for (i = from; i <= to; i++)
        retval += dir_u->entry_sizes[i];

    return retval;
}

static int direntry_unit_num(struct virtual_item *vi)
{
    struct direntry_uarea *dir_u = vi->vi_uarea;

    return dir_u->entry_count;
}

static void direntry_print_vi(struct virtual_item *vi)
{
    int i;
    struct direntry_uarea *dir_u = vi->vi_uarea;

    reiserfs_warning(NULL, "reiserfs-16104",
             "DIRENTRY, index %d, type 0x%x, %h, flags 0x%x",
             vi->vi_index, vi->vi_type, vi->vi_ih, dir_u->flags);
    printk("%d entries: ", dir_u->entry_count);
    for (i = 0; i < dir_u->entry_count; i++)
        printk("%d ", dir_u->entry_sizes[i]);
    printk("\n");
}

static struct item_operations direntry_ops = {
    .bytes_number = direntry_bytes_number,
    .decrement_key = direntry_decrement_key,
    .is_left_mergeable = direntry_is_left_mergeable,
    .print_item = direntry_print_item,
    .check_item = direntry_check_item,

    .create_vi = direntry_create_vi,
    .check_left = direntry_check_left,
    .check_right = direntry_check_right,
    .part_size = direntry_part_size,
    .unit_num = direntry_unit_num,
    .print_vi = direntry_print_vi
};

// Error catching functions to catch errors caused by incorrect item types.
//
static int errcatch_bytes_number(struct item_head *ih, int block_size)
{
    reiserfs_warning(NULL, "green-16001",
             "Invalid item type observed, run fsck ASAP");
    return 0;
}

static void errcatch_decrement_key(struct cpu_key *key)
{
    reiserfs_warning(NULL, "green-16002",
             "Invalid item type observed, run fsck ASAP");
}

static int errcatch_is_left_mergeable(struct reiserfs_key *key,
                      unsigned long bsize)
{
    reiserfs_warning(NULL, "green-16003",
             "Invalid item type observed, run fsck ASAP");
    return 0;
}

static void errcatch_print_item(struct item_head *ih, char *item)
{
    reiserfs_warning(NULL, "green-16004",
             "Invalid item type observed, run fsck ASAP");
}

static void errcatch_check_item(struct item_head *ih, char *item)
{
    reiserfs_warning(NULL, "green-16005",
             "Invalid item type observed, run fsck ASAP");
}

static int errcatch_create_vi(struct virtual_node *vn,
                  struct virtual_item *vi,
                  int is_affected, int insert_size)
{
    reiserfs_warning(NULL, "green-16006",
             "Invalid item type observed, run fsck ASAP");
    return 0;       // We might return -1 here as well, but it won't help as create_virtual_node() from where
    // this operation is called from is of return type void.
}

static int errcatch_check_left(struct virtual_item *vi, int free,
                   int start_skip, int end_skip)
{
    reiserfs_warning(NULL, "green-16007",
             "Invalid item type observed, run fsck ASAP");
    return -1;
}

static int errcatch_check_right(struct virtual_item *vi, int free)
{
    reiserfs_warning(NULL, "green-16008",
             "Invalid item type observed, run fsck ASAP");
    return -1;
}

static int errcatch_part_size(struct virtual_item *vi, int first, int count)
{
    reiserfs_warning(NULL, "green-16009",
             "Invalid item type observed, run fsck ASAP");
    return 0;
}

static int errcatch_unit_num(struct virtual_item *vi)
{
    reiserfs_warning(NULL, "green-16010",
             "Invalid item type observed, run fsck ASAP");
    return 0;
}

static void errcatch_print_vi(struct virtual_item *vi)
{
    reiserfs_warning(NULL, "green-16011",
             "Invalid item type observed, run fsck ASAP");
}

static struct item_operations errcatch_ops = {
    errcatch_bytes_number,
    errcatch_decrement_key,
    errcatch_is_left_mergeable,
    errcatch_print_item,
    errcatch_check_item,

    errcatch_create_vi,
    errcatch_check_left,
    errcatch_check_right,
    errcatch_part_size,
    errcatch_unit_num,
    errcatch_print_vi
};

//
//
#if ! (TYPE_STAT_DATA == 0 && TYPE_INDIRECT == 1 && TYPE_DIRECT == 2 && TYPE_DIRENTRY == 3)
#error Item types must use disk-format assigned values.
#endif

struct item_operations *item_ops[TYPE_ANY + 1] = {
    &stat_data_ops,
    &indirect_ops,
    &direct_ops,
    &direntry_ops,
    NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
    &errcatch_ops       /* This is to catch errors with invalid type (15th entry for TYPE_ANY) */
};