bmap.c

Go to the documentation of this file.

/*
 * bmap.c - NILFS block mapping.
 *
 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Written by Koji Sato <[email protected]>.
 */

#include <linux/fs.h>
#include <linux/string.h>
#include <linux/errno.h>
#include "nilfs.h"
#include "bmap.h"
#include "btree.h"
#include "direct.h"
#include "btnode.h"
#include "mdt.h"
#include "dat.h"
#include "alloc.h"

struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *bmap)
{
    struct the_nilfs *nilfs = bmap->b_inode->i_sb->s_fs_info;

    return nilfs->ns_dat;
}

static int nilfs_bmap_convert_error(struct nilfs_bmap *bmap,
                     const char *fname, int err)
{
    struct inode *inode = bmap->b_inode;

    if (err == -EINVAL) {
        nilfs_error(inode->i_sb, fname,
                "broken bmap (inode number=%lu)\n", inode->i_ino);
        err = -EIO;
    }
    return err;
}

int nilfs_bmap_lookup_at_level(struct nilfs_bmap *bmap, __u64 key, int level,
                   __u64 *ptrp)
{
    sector_t blocknr;
    int ret;

    down_read(&bmap->b_sem);
    ret = bmap->b_ops->bop_lookup(bmap, key, level, ptrp);
    if (ret < 0) {
        ret = nilfs_bmap_convert_error(bmap, __func__, ret);
        goto out;
    }
    if (NILFS_BMAP_USE_VBN(bmap)) {
        ret = nilfs_dat_translate(nilfs_bmap_get_dat(bmap), *ptrp,
                      &blocknr);
        if (!ret)
            *ptrp = blocknr;
    }

 out:
    up_read(&bmap->b_sem);
    return ret;
}

int nilfs_bmap_lookup_contig(struct nilfs_bmap *bmap, __u64 key, __u64 *ptrp,
                 unsigned maxblocks)
{
    int ret;

    down_read(&bmap->b_sem);
    ret = bmap->b_ops->bop_lookup_contig(bmap, key, ptrp, maxblocks);
    up_read(&bmap->b_sem);

    return nilfs_bmap_convert_error(bmap, __func__, ret);
}

static int nilfs_bmap_do_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
{
    __u64 keys[NILFS_BMAP_SMALL_HIGH + 1];
    __u64 ptrs[NILFS_BMAP_SMALL_HIGH + 1];
    int ret, n;

    if (bmap->b_ops->bop_check_insert != NULL) {
        ret = bmap->b_ops->bop_check_insert(bmap, key);
        if (ret > 0) {
            n = bmap->b_ops->bop_gather_data(
                bmap, keys, ptrs, NILFS_BMAP_SMALL_HIGH + 1);
            if (n < 0)
                return n;
            ret = nilfs_btree_convert_and_insert(
                bmap, key, ptr, keys, ptrs, n);
            if (ret == 0)
                bmap->b_u.u_flags |= NILFS_BMAP_LARGE;

            return ret;
        } else if (ret < 0)
            return ret;
    }

    return bmap->b_ops->bop_insert(bmap, key, ptr);
}

int nilfs_bmap_insert(struct nilfs_bmap *bmap,
              unsigned long key,
              unsigned long rec)
{
    int ret;

    down_write(&bmap->b_sem);
    ret = nilfs_bmap_do_insert(bmap, key, rec);
    up_write(&bmap->b_sem);

    return nilfs_bmap_convert_error(bmap, __func__, ret);
}

static int nilfs_bmap_do_delete(struct nilfs_bmap *bmap, __u64 key)
{
    __u64 keys[NILFS_BMAP_LARGE_LOW + 1];
    __u64 ptrs[NILFS_BMAP_LARGE_LOW + 1];
    int ret, n;

    if (bmap->b_ops->bop_check_delete != NULL) {
        ret = bmap->b_ops->bop_check_delete(bmap, key);
        if (ret > 0) {
            n = bmap->b_ops->bop_gather_data(
                bmap, keys, ptrs, NILFS_BMAP_LARGE_LOW + 1);
            if (n < 0)
                return n;
            ret = nilfs_direct_delete_and_convert(
                bmap, key, keys, ptrs, n);
            if (ret == 0)
                bmap->b_u.u_flags &= ~NILFS_BMAP_LARGE;

            return ret;
        } else if (ret < 0)
            return ret;
    }

    return bmap->b_ops->bop_delete(bmap, key);
}

int nilfs_bmap_last_key(struct nilfs_bmap *bmap, unsigned long *key)
{
    __u64 lastkey;
    int ret;

    down_read(&bmap->b_sem);
    ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
    up_read(&bmap->b_sem);

    if (ret < 0)
        ret = nilfs_bmap_convert_error(bmap, __func__, ret);
    else
        *key = lastkey;
    return ret;
}

int nilfs_bmap_delete(struct nilfs_bmap *bmap, unsigned long key)
{
    int ret;

    down_write(&bmap->b_sem);
    ret = nilfs_bmap_do_delete(bmap, key);
    up_write(&bmap->b_sem);

    return nilfs_bmap_convert_error(bmap, __func__, ret);
}

static int nilfs_bmap_do_truncate(struct nilfs_bmap *bmap, unsigned long key)
{
    __u64 lastkey;
    int ret;

    ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
    if (ret < 0) {
        if (ret == -ENOENT)
            ret = 0;
        return ret;
    }

    while (key <= lastkey) {
        ret = nilfs_bmap_do_delete(bmap, lastkey);
        if (ret < 0)
            return ret;
        ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
        if (ret < 0) {
            if (ret == -ENOENT)
                ret = 0;
            return ret;
        }
    }
    return 0;
}

int nilfs_bmap_truncate(struct nilfs_bmap *bmap, unsigned long key)
{
    int ret;

    down_write(&bmap->b_sem);
    ret = nilfs_bmap_do_truncate(bmap, key);
    up_write(&bmap->b_sem);

    return nilfs_bmap_convert_error(bmap, __func__, ret);
}

void nilfs_bmap_clear(struct nilfs_bmap *bmap)
{
    down_write(&bmap->b_sem);
    if (bmap->b_ops->bop_clear != NULL)
        bmap->b_ops->bop_clear(bmap);
    up_write(&bmap->b_sem);
}

int nilfs_bmap_propagate(struct nilfs_bmap *bmap, struct buffer_head *bh)
{
    int ret;

    down_write(&bmap->b_sem);
    ret = bmap->b_ops->bop_propagate(bmap, bh);
    up_write(&bmap->b_sem);

    return nilfs_bmap_convert_error(bmap, __func__, ret);
}

void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *bmap,
                     struct list_head *listp)
{
    if (bmap->b_ops->bop_lookup_dirty_buffers != NULL)
        bmap->b_ops->bop_lookup_dirty_buffers(bmap, listp);
}

int nilfs_bmap_assign(struct nilfs_bmap *bmap,
              struct buffer_head **bh,
              unsigned long blocknr,
              union nilfs_binfo *binfo)
{
    int ret;

    down_write(&bmap->b_sem);
    ret = bmap->b_ops->bop_assign(bmap, bh, blocknr, binfo);
    up_write(&bmap->b_sem);

    return nilfs_bmap_convert_error(bmap, __func__, ret);
}

int nilfs_bmap_mark(struct nilfs_bmap *bmap, __u64 key, int level)
{
    int ret;

    if (bmap->b_ops->bop_mark == NULL)
        return 0;

    down_write(&bmap->b_sem);
    ret = bmap->b_ops->bop_mark(bmap, key, level);
    up_write(&bmap->b_sem);

    return nilfs_bmap_convert_error(bmap, __func__, ret);
}

int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *bmap)
{
    int ret;

    down_write(&bmap->b_sem);
    ret = nilfs_bmap_dirty(bmap);
    nilfs_bmap_clear_dirty(bmap);
    up_write(&bmap->b_sem);
    return ret;
}


/*
 * Internal use only
 */
__u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,
                  const struct buffer_head *bh)
{
    struct buffer_head *pbh;
    __u64 key;

    key = page_index(bh->b_page) << (PAGE_CACHE_SHIFT -
                     bmap->b_inode->i_blkbits);
    for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page)
        key++;

    return key;
}

__u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *bmap, __u64 key)
{
    __s64 diff;

    diff = key - bmap->b_last_allocated_key;
    if ((nilfs_bmap_keydiff_abs(diff) < NILFS_INODE_BMAP_SIZE) &&
        (bmap->b_last_allocated_ptr != NILFS_BMAP_INVALID_PTR) &&
        (bmap->b_last_allocated_ptr + diff > 0))
        return bmap->b_last_allocated_ptr + diff;
    else
        return NILFS_BMAP_INVALID_PTR;
}

#define NILFS_BMAP_GROUP_DIV    8
__u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
{
    struct inode *dat = nilfs_bmap_get_dat(bmap);
    unsigned long entries_per_group = nilfs_palloc_entries_per_group(dat);
    unsigned long group = bmap->b_inode->i_ino / entries_per_group;

    return group * entries_per_group +
        (bmap->b_inode->i_ino % NILFS_BMAP_GROUP_DIV) *
        (entries_per_group / NILFS_BMAP_GROUP_DIV);
}

static struct lock_class_key nilfs_bmap_dat_lock_key;
static struct lock_class_key nilfs_bmap_mdt_lock_key;

int nilfs_bmap_read(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
{
    if (raw_inode == NULL)
        memset(bmap->b_u.u_data, 0, NILFS_BMAP_SIZE);
    else
        memcpy(bmap->b_u.u_data, raw_inode->i_bmap, NILFS_BMAP_SIZE);

    init_rwsem(&bmap->b_sem);
    bmap->b_state = 0;
    bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
    switch (bmap->b_inode->i_ino) {
    case NILFS_DAT_INO:
        bmap->b_ptr_type = NILFS_BMAP_PTR_P;
        bmap->b_last_allocated_key = 0;
        bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
        lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
        break;
    case NILFS_CPFILE_INO:
    case NILFS_SUFILE_INO:
        bmap->b_ptr_type = NILFS_BMAP_PTR_VS;
        bmap->b_last_allocated_key = 0;
        bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
        lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
        break;
    case NILFS_IFILE_INO:
        lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
        /* Fall through */
    default:
        bmap->b_ptr_type = NILFS_BMAP_PTR_VM;
        bmap->b_last_allocated_key = 0;
        bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
        break;
    }

    return (bmap->b_u.u_flags & NILFS_BMAP_LARGE) ?
        nilfs_btree_init(bmap) : nilfs_direct_init(bmap);
}

void nilfs_bmap_write(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
{
    down_write(&bmap->b_sem);
    memcpy(raw_inode->i_bmap, bmap->b_u.u_data,
           NILFS_INODE_BMAP_SIZE * sizeof(__le64));
    if (bmap->b_inode->i_ino == NILFS_DAT_INO)
        bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;

    up_write(&bmap->b_sem);
}

void nilfs_bmap_init_gc(struct nilfs_bmap *bmap)
{
    memset(&bmap->b_u, 0, NILFS_BMAP_SIZE);
    init_rwsem(&bmap->b_sem);
    bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
    bmap->b_ptr_type = NILFS_BMAP_PTR_U;
    bmap->b_last_allocated_key = 0;
    bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
    bmap->b_state = 0;
    nilfs_btree_init_gc(bmap);
}

void nilfs_bmap_save(const struct nilfs_bmap *bmap,
             struct nilfs_bmap_store *store)
{
    memcpy(store->data, bmap->b_u.u_data, sizeof(store->data));
    store->last_allocated_key = bmap->b_last_allocated_key;
    store->last_allocated_ptr = bmap->b_last_allocated_ptr;
    store->state = bmap->b_state;
}

void nilfs_bmap_restore(struct nilfs_bmap *bmap,
            const struct nilfs_bmap_store *store)
{
    memcpy(bmap->b_u.u_data, store->data, sizeof(store->data));
    bmap->b_last_allocated_key = store->last_allocated_key;
    bmap->b_last_allocated_ptr = store->last_allocated_ptr;
    bmap->b_state = store->state;
}