[mirror_ubuntu-artful-kernel.git] / fs / ufs / inode.c

/*
 *  linux/fs/ufs/inode.c
 *
 * Copyright (C) 1998
 * Daniel Pirkl <daniel.pirkl@email.cz>
 * Charles University, Faculty of Mathematics and Physics
 *
 *  from
 *
 *  linux/fs/ext2/inode.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/fs/minix/inode.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  Goal-directed block allocation by Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
 *  Big-endian to little-endian byte-swapping/bitmaps by
 *        David S. Miller (davem@caip.rutgers.edu), 1995
 */

#include <linux/uaccess.h>

#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/buffer_head.h>
#include <linux/writeback.h>

#include "ufs_fs.h"
#include "ufs.h"
#include "swab.h"
#include "util.h"

static int ufs_block_to_path(struct inode *inode, sector_t i_block, unsigned offsets[4])
{
        struct ufs_sb_private_info *uspi = UFS_SB(inode->i_sb)->s_uspi;
        int ptrs = uspi->s_apb;
        int ptrs_bits = uspi->s_apbshift;
        const long direct_blocks = UFS_NDADDR,
                indirect_blocks = ptrs,
                double_blocks = (1 << (ptrs_bits * 2));
        int n = 0;


        UFSD("ptrs=uspi->s_apb = %d,double_blocks=%ld \n",ptrs,double_blocks);
        if (i_block < direct_blocks) {
                offsets[n++] = i_block;
        } else if ((i_block -= direct_blocks) < indirect_blocks) {
                offsets[n++] = UFS_IND_BLOCK;
                offsets[n++] = i_block;
        } else if ((i_block -= indirect_blocks) < double_blocks) {
                offsets[n++] = UFS_DIND_BLOCK;
                offsets[n++] = i_block >> ptrs_bits;
                offsets[n++] = i_block & (ptrs - 1);
        } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
                offsets[n++] = UFS_TIND_BLOCK;
                offsets[n++] = i_block >> (ptrs_bits * 2);
                offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
                offsets[n++] = i_block & (ptrs - 1);
        } else {
                ufs_warning(inode->i_sb, "ufs_block_to_path", "block > big");
        }
        return n;
}

typedef struct {
        void    *p;
        union {
                __fs32  key32;
                __fs64  key64;
        };
        struct buffer_head *bh;
} Indirect;

static inline int grow_chain32(struct ufs_inode_info *ufsi,
                               struct buffer_head *bh, __fs32 *v,
                               Indirect *from, Indirect *to)
{
        Indirect *p;
        unsigned seq;
        to->bh = bh;
        do {
                seq = read_seqbegin(&ufsi->meta_lock);
                to->key32 = *(__fs32 *)(to->p = v);
                for (p = from; p <= to && p->key32 == *(__fs32 *)p->p; p++)
                        ;
        } while (read_seqretry(&ufsi->meta_lock, seq));
        return (p > to);
}

static inline int grow_chain64(struct ufs_inode_info *ufsi,
                               struct buffer_head *bh, __fs64 *v,
                               Indirect *from, Indirect *to)
{
        Indirect *p;
        unsigned seq;
        to->bh = bh;
        do {
                seq = read_seqbegin(&ufsi->meta_lock);
                to->key64 = *(__fs64 *)(to->p = v);
                for (p = from; p <= to && p->key64 == *(__fs64 *)p->p; p++)
                        ;
        } while (read_seqretry(&ufsi->meta_lock, seq));
        return (p > to);
}

/*
 * Returns the location of the fragment from
 * the beginning of the filesystem.
 */

static u64 ufs_frag_map(struct inode *inode, unsigned offsets[4], int depth)
{
        struct ufs_inode_info *ufsi = UFS_I(inode);
        struct super_block *sb = inode->i_sb;
        struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
        u64 mask = (u64) uspi->s_apbmask>>uspi->s_fpbshift;
        int shift = uspi->s_apbshift-uspi->s_fpbshift;
        Indirect chain[4], *q = chain;
        unsigned *p;
        unsigned flags = UFS_SB(sb)->s_flags;
        u64 res = 0;

        UFSD(": uspi->s_fpbshift = %d ,uspi->s_apbmask = %x, mask=%llx\n",
                uspi->s_fpbshift, uspi->s_apbmask,
                (unsigned long long)mask);

        if (depth == 0)
                goto no_block;

again:
        p = offsets;

        if ((flags & UFS_TYPE_MASK) == UFS_TYPE_UFS2)
                goto ufs2;

        if (!grow_chain32(ufsi, NULL, &ufsi->i_u1.i_data[*p++], chain, q))
                goto changed;
        if (!q->key32)
                goto no_block;
        while (--depth) {
                __fs32 *ptr;
                struct buffer_head *bh;
                unsigned n = *p++;

                bh = sb_bread(sb, uspi->s_sbbase +
                                  fs32_to_cpu(sb, q->key32) + (n>>shift));
                if (!bh)
                        goto no_block;
                ptr = (__fs32 *)bh->b_data + (n & mask);
                if (!grow_chain32(ufsi, bh, ptr, chain, ++q))
                        goto changed;
                if (!q->key32)
                        goto no_block;
        }
        res = fs32_to_cpu(sb, q->key32);
        goto found;

ufs2:
        if (!grow_chain64(ufsi, NULL, &ufsi->i_u1.u2_i_data[*p++], chain, q))
                goto changed;
        if (!q->key64)
                goto no_block;

        while (--depth) {
                __fs64 *ptr;
                struct buffer_head *bh;
                unsigned n = *p++;

                bh = sb_bread(sb, uspi->s_sbbase +
                                  fs64_to_cpu(sb, q->key64) + (n>>shift));
                if (!bh)
                        goto no_block;
                ptr = (__fs64 *)bh->b_data + (n & mask);
                if (!grow_chain64(ufsi, bh, ptr, chain, ++q))
                        goto changed;
                if (!q->key64)
                        goto no_block;
        }
        res = fs64_to_cpu(sb, q->key64);
found:
        res += uspi->s_sbbase;
no_block:
        while (q > chain) {
                brelse(q->bh);
                q--;
        }
        return res;

changed:
        while (q > chain) {
                brelse(q->bh);
                q--;
        }
        goto again;
}

/*
 * Unpacking tails: we have a file with partial final block and
 * we had been asked to extend it.  If the fragment being written
 * is within the same block, we need to extend the tail just to cover
 * that fragment.  Otherwise the tail is extended to full block.
 *
 * Note that we might need to create a _new_ tail, but that will
 * be handled elsewhere; this is strictly for resizing old
 * ones.
 */
static bool
ufs_extend_tail(struct inode *inode, u64 writes_to,
                  int *err, struct page *locked_page)
{
        struct ufs_inode_info *ufsi = UFS_I(inode);
        struct super_block *sb = inode->i_sb;
        struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
        unsigned lastfrag = ufsi->i_lastfrag;   /* it's a short file, so unsigned is enough */
        unsigned block = ufs_fragstoblks(lastfrag);
        unsigned new_size;
        void *p;
        u64 tmp;

        if (writes_to < (lastfrag | uspi->s_fpbmask))
                new_size = (writes_to & uspi->s_fpbmask) + 1;
        else
                new_size = uspi->s_fpb;

        p = ufs_get_direct_data_ptr(uspi, ufsi, block);
        tmp = ufs_new_fragments(inode, p, lastfrag, ufs_data_ptr_to_cpu(sb, p),
                                new_size - (lastfrag & uspi->s_fpbmask), err,
                                locked_page);
        return tmp != 0;
}

/**
 * ufs_inode_getfrag() - allocate new fragment(s)
 * @inode: pointer to inode
 * @index: number of block pointer within the inode's array.
 * @new_fragment: number of new allocated fragment(s)
 * @err: we set it if something wrong
 * @new: we set it if we allocate new block
 * @locked_page: for ufs_new_fragments()
 */
static u64
ufs_inode_getfrag(struct inode *inode, unsigned index,
                  sector_t new_fragment, int *err,
                  int *new, struct page *locked_page)
{
        struct ufs_inode_info *ufsi = UFS_I(inode);
        struct super_block *sb = inode->i_sb;
        struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
        u64 tmp, goal, lastfrag;
        unsigned nfrags = uspi->s_fpb;
        void *p;

        /* TODO : to be done for write support
        if ( (flags & UFS_TYPE_MASK) == UFS_TYPE_UFS2)
             goto ufs2;
         */

        p = ufs_get_direct_data_ptr(uspi, ufsi, index);
        tmp = ufs_data_ptr_to_cpu(sb, p);
        if (tmp)
                goto out;

        lastfrag = ufsi->i_lastfrag;

        /* will that be a new tail? */
        if (new_fragment < UFS_NDIR_FRAGMENT && new_fragment >= lastfrag)
                nfrags = (new_fragment & uspi->s_fpbmask) + 1;

        goal = 0;
        if (index) {
                goal = ufs_data_ptr_to_cpu(sb,
                                 ufs_get_direct_data_ptr(uspi, ufsi, index - 1));
                if (goal)
                        goal += uspi->s_fpb;
        }
        tmp = ufs_new_fragments(inode, p, ufs_blknum(new_fragment),
                                goal, nfrags, err, locked_page);

        if (!tmp) {
                *err = -ENOSPC;
                return 0;
        }

        if (new)
                *new = 1;
        inode->i_ctime = current_time(inode);
        if (IS_SYNC(inode))
                ufs_sync_inode (inode);
        mark_inode_dirty(inode);
out:
        return tmp + uspi->s_sbbase;

     /* This part : To be implemented ....
        Required only for writing, not required for READ-ONLY.
ufs2:

        u2_block = ufs_fragstoblks(fragment);
        u2_blockoff = ufs_fragnum(fragment);
        p = ufsi->i_u1.u2_i_data + block;
        goal = 0;

repeat2:
        tmp = fs32_to_cpu(sb, *p);
        lastfrag = ufsi->i_lastfrag;

     */
}

/**
 * ufs_inode_getblock() - allocate new block
 * @inode: pointer to inode
 * @ind_block: block number of the indirect block
 * @index: number of pointer within the indirect block
 * @new_fragment: number of new allocated fragment
 *  (block will hold this fragment and also uspi->s_fpb-1)
 * @err: see ufs_inode_getfrag()
 * @new: see ufs_inode_getfrag()
 * @locked_page: see ufs_inode_getfrag()
 */
static u64
ufs_inode_getblock(struct inode *inode, u64 ind_block,
                  unsigned index, sector_t new_fragment, int *err,
                  int *new, struct page *locked_page)
{
        struct super_block *sb = inode->i_sb;
        struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
        int shift = uspi->s_apbshift - uspi->s_fpbshift;
        u64 tmp = 0, goal;
        struct buffer_head *bh;
        void *p;

        if (!ind_block)
                return 0;

        bh = sb_bread(sb, ind_block + (index >> shift));
        if (unlikely(!bh)) {
                *err = -EIO;
                return 0;
        }

        index &= uspi->s_apbmask >> uspi->s_fpbshift;
        if (uspi->fs_magic == UFS2_MAGIC)
                p = (__fs64 *)bh->b_data + index;
        else
                p = (__fs32 *)bh->b_data + index;

        tmp = ufs_data_ptr_to_cpu(sb, p);
        if (tmp)
                goto out;

        if (index && (uspi->fs_magic == UFS2_MAGIC ?
                      (tmp = fs64_to_cpu(sb, ((__fs64 *)bh->b_data)[index-1])) :
                      (tmp = fs32_to_cpu(sb, ((__fs32 *)bh->b_data)[index-1]))))
                goal = tmp + uspi->s_fpb;
        else
                goal = bh->b_blocknr + uspi->s_fpb;
        tmp = ufs_new_fragments(inode, p, ufs_blknum(new_fragment), goal,
                                uspi->s_fpb, err, locked_page);
        if (!tmp)
                goto out;

        if (new)
                *new = 1;

        mark_buffer_dirty(bh);
        if (IS_SYNC(inode))
                sync_dirty_buffer(bh);
        inode->i_ctime = current_time(inode);
        mark_inode_dirty(inode);
out:
        brelse (bh);
        UFSD("EXIT\n");
        if (tmp)
                tmp += uspi->s_sbbase;
        return tmp;
}

/**
 * ufs_getfrag_block() - `get_block_t' function, interface between UFS and
 * readpage, writepage and so on
 */

static int ufs_getfrag_block(struct inode *inode, sector_t fragment, struct buffer_head *bh_result, int create)
{
        struct super_block *sb = inode->i_sb;
        struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
        int err = 0, new = 0;
        unsigned offsets[4];
        int depth = ufs_block_to_path(inode, fragment >> uspi->s_fpbshift, offsets);
        u64 phys64 = 0;
        unsigned frag = fragment & uspi->s_fpbmask;

        if (!create) {
                phys64 = ufs_frag_map(inode, offsets, depth);
                if (phys64)
                        map_bh(bh_result, sb, phys64 + frag);
                return 0;
        }

        /* This code entered only while writing ....? */

        mutex_lock(&UFS_I(inode)->truncate_mutex);

        UFSD("ENTER, ino %lu, fragment %llu\n", inode->i_ino, (unsigned long long)fragment);
        if (unlikely(!depth)) {
                ufs_warning(sb, "ufs_get_block", "block > big");
                err = -EIO;
                goto out;
        }

        if (UFS_I(inode)->i_lastfrag < UFS_NDIR_FRAGMENT) {
                unsigned lastfrag = UFS_I(inode)->i_lastfrag;
                unsigned tailfrags = lastfrag & uspi->s_fpbmask;
                if (tailfrags && fragment >= lastfrag) {
                        if (!ufs_extend_tail(inode, fragment,
                                             &err, bh_result->b_page))
                                goto out;
                }
        }

        if (depth == 1) {
                phys64 = ufs_inode_getfrag(inode, offsets[0], fragment,
                                           &err, &new, bh_result->b_page);
        } else {
                int i;
                phys64 = ufs_inode_getfrag(inode, offsets[0], fragment,
                                           &err, NULL, NULL);
                for (i = 1; i < depth - 1; i++)
                        phys64 = ufs_inode_getblock(inode, phys64, offsets[i],
                                                fragment, &err, NULL, NULL);
                phys64 = ufs_inode_getblock(inode, phys64, offsets[depth - 1],
                                        fragment, &err, &new, bh_result->b_page);
        }
out:
        if (phys64) {
                phys64 += frag;
                map_bh(bh_result, sb, phys64);
                if (new)
                        set_buffer_new(bh_result);
        }
        mutex_unlock(&UFS_I(inode)->truncate_mutex);
        return err;
}

static int ufs_writepage(struct page *page, struct writeback_control *wbc)
{
        return block_write_full_page(page,ufs_getfrag_block,wbc);
}

static int ufs_readpage(struct file *file, struct page *page)
{
        return block_read_full_page(page,ufs_getfrag_block);
}

int ufs_prepare_chunk(struct page *page, loff_t pos, unsigned len)
{
        return __block_write_begin(page, pos, len, ufs_getfrag_block);
}

static void ufs_truncate_blocks(struct inode *);

static void ufs_write_failed(struct address_space *mapping, loff_t to)
{
        struct inode *inode = mapping->host;

        if (to > inode->i_size) {
                truncate_pagecache(inode, inode->i_size);
                ufs_truncate_blocks(inode);
        }
}

static int ufs_write_begin(struct file *file, struct address_space *mapping,
                        loff_t pos, unsigned len, unsigned flags,
                        struct page **pagep, void **fsdata)
{
        int ret;

        ret = block_write_begin(mapping, pos, len, flags, pagep,
                                ufs_getfrag_block);
        if (unlikely(ret))
                ufs_write_failed(mapping, pos + len);

        return ret;
}

static int ufs_write_end(struct file *file, struct address_space *mapping,
                        loff_t pos, unsigned len, unsigned copied,
                        struct page *page, void *fsdata)
{
        int ret;

        ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
        if (ret < len)
                ufs_write_failed(mapping, pos + len);
        return ret;
}

static sector_t ufs_bmap(struct address_space *mapping, sector_t block)
{
        return generic_block_bmap(mapping,block,ufs_getfrag_block);
}

const struct address_space_operations ufs_aops = {
        .readpage = ufs_readpage,
        .writepage = ufs_writepage,
        .write_begin = ufs_write_begin,
        .write_end = ufs_write_end,
        .bmap = ufs_bmap
};

static void ufs_set_inode_ops(struct inode *inode)
{
        if (S_ISREG(inode->i_mode)) {
                inode->i_op = &ufs_file_inode_operations;
                inode->i_fop = &ufs_file_operations;
                inode->i_mapping->a_ops = &ufs_aops;
        } else if (S_ISDIR(inode->i_mode)) {
                inode->i_op = &ufs_dir_inode_operations;
                inode->i_fop = &ufs_dir_operations;
                inode->i_mapping->a_ops = &ufs_aops;
        } else if (S_ISLNK(inode->i_mode)) {
                if (!inode->i_blocks) {
                        inode->i_link = (char *)UFS_I(inode)->i_u1.i_symlink;
                        inode->i_op = &simple_symlink_inode_operations;
                } else {
                        inode->i_mapping->a_ops = &ufs_aops;
                        inode->i_op = &page_symlink_inode_operations;
                        inode_nohighmem(inode);
                }
        } else
                init_special_inode(inode, inode->i_mode,
                                   ufs_get_inode_dev(inode->i_sb, UFS_I(inode)));
}

static int ufs1_read_inode(struct inode *inode, struct ufs_inode *ufs_inode)
{
        struct ufs_inode_info *ufsi = UFS_I(inode);
        struct super_block *sb = inode->i_sb;
        umode_t mode;

        /*
         * Copy data to the in-core inode.
         */
        inode->i_mode = mode = fs16_to_cpu(sb, ufs_inode->ui_mode);
        set_nlink(inode, fs16_to_cpu(sb, ufs_inode->ui_nlink));
        if (inode->i_nlink == 0) {
                ufs_error (sb, "ufs_read_inode", "inode %lu has zero nlink\n", inode->i_ino);
                return -1;
        }

        /*
         * Linux now has 32-bit uid and gid, so we can support EFT.
         */
        i_uid_write(inode, ufs_get_inode_uid(sb, ufs_inode));
        i_gid_write(inode, ufs_get_inode_gid(sb, ufs_inode));

        inode->i_size = fs64_to_cpu(sb, ufs_inode->ui_size);
        inode->i_atime.tv_sec = fs32_to_cpu(sb, ufs_inode->ui_atime.tv_sec);
        inode->i_ctime.tv_sec = fs32_to_cpu(sb, ufs_inode->ui_ctime.tv_sec);
        inode->i_mtime.tv_sec = fs32_to_cpu(sb, ufs_inode->ui_mtime.tv_sec);
        inode->i_mtime.tv_nsec = 0;
        inode->i_atime.tv_nsec = 0;
        inode->i_ctime.tv_nsec = 0;
        inode->i_blocks = fs32_to_cpu(sb, ufs_inode->ui_blocks);
        inode->i_generation = fs32_to_cpu(sb, ufs_inode->ui_gen);
        ufsi->i_flags = fs32_to_cpu(sb, ufs_inode->ui_flags);
        ufsi->i_shadow = fs32_to_cpu(sb, ufs_inode->ui_u3.ui_sun.ui_shadow);
        ufsi->i_oeftflag = fs32_to_cpu(sb, ufs_inode->ui_u3.ui_sun.ui_oeftflag);


        if (S_ISCHR(mode) || S_ISBLK(mode) || inode->i_blocks) {
                memcpy(ufsi->i_u1.i_data, &ufs_inode->ui_u2.ui_addr,
                       sizeof(ufs_inode->ui_u2.ui_addr));
        } else {
                memcpy(ufsi->i_u1.i_symlink, ufs_inode->ui_u2.ui_symlink,
                       sizeof(ufs_inode->ui_u2.ui_symlink) - 1);
                ufsi->i_u1.i_symlink[sizeof(ufs_inode->ui_u2.ui_symlink) - 1] = 0;
        }
        return 0;
}

static int ufs2_read_inode(struct inode *inode, struct ufs2_inode *ufs2_inode)
{
        struct ufs_inode_info *ufsi = UFS_I(inode);
        struct super_block *sb = inode->i_sb;
        umode_t mode;

        UFSD("Reading ufs2 inode, ino %lu\n", inode->i_ino);
        /*
         * Copy data to the in-core inode.
         */
        inode->i_mode = mode = fs16_to_cpu(sb, ufs2_inode->ui_mode);
        set_nlink(inode, fs16_to_cpu(sb, ufs2_inode->ui_nlink));
        if (inode->i_nlink == 0) {
                ufs_error (sb, "ufs_read_inode", "inode %lu has zero nlink\n", inode->i_ino);
                return -1;
        }

        /*
         * Linux now has 32-bit uid and gid, so we can support EFT.
         */
        i_uid_write(inode, fs32_to_cpu(sb, ufs2_inode->ui_uid));
        i_gid_write(inode, fs32_to_cpu(sb, ufs2_inode->ui_gid));

        inode->i_size = fs64_to_cpu(sb, ufs2_inode->ui_size);
        inode->i_atime.tv_sec = fs64_to_cpu(sb, ufs2_inode->ui_atime);
        inode->i_ctime.tv_sec = fs64_to_cpu(sb, ufs2_inode->ui_ctime);
        inode->i_mtime.tv_sec = fs64_to_cpu(sb, ufs2_inode->ui_mtime);
        inode->i_atime.tv_nsec = fs32_to_cpu(sb, ufs2_inode->ui_atimensec);
        inode->i_ctime.tv_nsec = fs32_to_cpu(sb, ufs2_inode->ui_ctimensec);
        inode->i_mtime.tv_nsec = fs32_to_cpu(sb, ufs2_inode->ui_mtimensec);
        inode->i_blocks = fs64_to_cpu(sb, ufs2_inode->ui_blocks);
        inode->i_generation = fs32_to_cpu(sb, ufs2_inode->ui_gen);
        ufsi->i_flags = fs32_to_cpu(sb, ufs2_inode->ui_flags);
        /*
        ufsi->i_shadow = fs32_to_cpu(sb, ufs_inode->ui_u3.ui_sun.ui_shadow);
        ufsi->i_oeftflag = fs32_to_cpu(sb, ufs_inode->ui_u3.ui_sun.ui_oeftflag);
        */

        if (S_ISCHR(mode) || S_ISBLK(mode) || inode->i_blocks) {
                memcpy(ufsi->i_u1.u2_i_data, &ufs2_inode->ui_u2.ui_addr,
                       sizeof(ufs2_inode->ui_u2.ui_addr));
        } else {
                memcpy(ufsi->i_u1.i_symlink, ufs2_inode->ui_u2.ui_symlink,
                       sizeof(ufs2_inode->ui_u2.ui_symlink) - 1);
                ufsi->i_u1.i_symlink[sizeof(ufs2_inode->ui_u2.ui_symlink) - 1] = 0;
        }
        return 0;
}

struct inode *ufs_iget(struct super_block *sb, unsigned long ino)
{
        struct ufs_inode_info *ufsi;
        struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
        struct buffer_head * bh;
        struct inode *inode;
        int err;

        UFSD("ENTER, ino %lu\n", ino);

        if (ino < UFS_ROOTINO || ino > (uspi->s_ncg * uspi->s_ipg)) {
                ufs_warning(sb, "ufs_read_inode", "bad inode number (%lu)\n",
                            ino);
                return ERR_PTR(-EIO);
        }

        inode = iget_locked(sb, ino);
        if (!inode)
                return ERR_PTR(-ENOMEM);
        if (!(inode->i_state & I_NEW))
                return inode;

        ufsi = UFS_I(inode);

        bh = sb_bread(sb, uspi->s_sbbase + ufs_inotofsba(inode->i_ino));
        if (!bh) {
                ufs_warning(sb, "ufs_read_inode", "unable to read inode %lu\n",
                            inode->i_ino);
                goto bad_inode;
        }
        if ((UFS_SB(sb)->s_flags & UFS_TYPE_MASK) == UFS_TYPE_UFS2) {
                struct ufs2_inode *ufs2_inode = (struct ufs2_inode *)bh->b_data;

                err = ufs2_read_inode(inode,
                                      ufs2_inode + ufs_inotofsbo(inode->i_ino));
        } else {
                struct ufs_inode *ufs_inode = (struct ufs_inode *)bh->b_data;

                err = ufs1_read_inode(inode,
                                      ufs_inode + ufs_inotofsbo(inode->i_ino));
        }

        if (err)
                goto bad_inode;
        inode->i_version++;
        ufsi->i_lastfrag =
                (inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift;
        ufsi->i_dir_start_lookup = 0;
        ufsi->i_osync = 0;

        ufs_set_inode_ops(inode);

        brelse(bh);

        UFSD("EXIT\n");
        unlock_new_inode(inode);
        return inode;

bad_inode:
        iget_failed(inode);
        return ERR_PTR(-EIO);
}

static void ufs1_update_inode(struct inode *inode, struct ufs_inode *ufs_inode)
{
        struct super_block *sb = inode->i_sb;
        struct ufs_inode_info *ufsi = UFS_I(inode);

        ufs_inode->ui_mode = cpu_to_fs16(sb, inode->i_mode);
        ufs_inode->ui_nlink = cpu_to_fs16(sb, inode->i_nlink);

        ufs_set_inode_uid(sb, ufs_inode, i_uid_read(inode));
        ufs_set_inode_gid(sb, ufs_inode, i_gid_read(inode));

        ufs_inode->ui_size = cpu_to_fs64(sb, inode->i_size);
        ufs_inode->ui_atime.tv_sec = cpu_to_fs32(sb, inode->i_atime.tv_sec);
        ufs_inode->ui_atime.tv_usec = 0;
        ufs_inode->ui_ctime.tv_sec = cpu_to_fs32(sb, inode->i_ctime.tv_sec);
        ufs_inode->ui_ctime.tv_usec = 0;
        ufs_inode->ui_mtime.tv_sec = cpu_to_fs32(sb, inode->i_mtime.tv_sec);
        ufs_inode->ui_mtime.tv_usec = 0;
        ufs_inode->ui_blocks = cpu_to_fs32(sb, inode->i_blocks);
        ufs_inode->ui_flags = cpu_to_fs32(sb, ufsi->i_flags);
        ufs_inode->ui_gen = cpu_to_fs32(sb, inode->i_generation);

        if ((UFS_SB(sb)->s_flags & UFS_UID_MASK) == UFS_UID_EFT) {
                ufs_inode->ui_u3.ui_sun.ui_shadow = cpu_to_fs32(sb, ufsi->i_shadow);
                ufs_inode->ui_u3.ui_sun.ui_oeftflag = cpu_to_fs32(sb, ufsi->i_oeftflag);
        }

        if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
                /* ufs_inode->ui_u2.ui_addr.ui_db[0] = cpu_to_fs32(sb, inode->i_rdev); */
                ufs_inode->ui_u2.ui_addr.ui_db[0] = ufsi->i_u1.i_data[0];
        } else if (inode->i_blocks) {
                memcpy(&ufs_inode->ui_u2.ui_addr, ufsi->i_u1.i_data,
                       sizeof(ufs_inode->ui_u2.ui_addr));
        }
        else {
                memcpy(&ufs_inode->ui_u2.ui_symlink, ufsi->i_u1.i_symlink,
                       sizeof(ufs_inode->ui_u2.ui_symlink));
        }

        if (!inode->i_nlink)
                memset (ufs_inode, 0, sizeof(struct ufs_inode));
}

static void ufs2_update_inode(struct inode *inode, struct ufs2_inode *ufs_inode)
{
        struct super_block *sb = inode->i_sb;
        struct ufs_inode_info *ufsi = UFS_I(inode);

        UFSD("ENTER\n");
        ufs_inode->ui_mode = cpu_to_fs16(sb, inode->i_mode);
        ufs_inode->ui_nlink = cpu_to_fs16(sb, inode->i_nlink);

        ufs_inode->ui_uid = cpu_to_fs32(sb, i_uid_read(inode));
        ufs_inode->ui_gid = cpu_to_fs32(sb, i_gid_read(inode));

        ufs_inode->ui_size = cpu_to_fs64(sb, inode->i_size);
        ufs_inode->ui_atime = cpu_to_fs64(sb, inode->i_atime.tv_sec);
        ufs_inode->ui_atimensec = cpu_to_fs32(sb, inode->i_atime.tv_nsec);
        ufs_inode->ui_ctime = cpu_to_fs64(sb, inode->i_ctime.tv_sec);
        ufs_inode->ui_ctimensec = cpu_to_fs32(sb, inode->i_ctime.tv_nsec);
        ufs_inode->ui_mtime = cpu_to_fs64(sb, inode->i_mtime.tv_sec);
        ufs_inode->ui_mtimensec = cpu_to_fs32(sb, inode->i_mtime.tv_nsec);

        ufs_inode->ui_blocks = cpu_to_fs64(sb, inode->i_blocks);
        ufs_inode->ui_flags = cpu_to_fs32(sb, ufsi->i_flags);
        ufs_inode->ui_gen = cpu_to_fs32(sb, inode->i_generation);

        if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
                /* ufs_inode->ui_u2.ui_addr.ui_db[0] = cpu_to_fs32(sb, inode->i_rdev); */
                ufs_inode->ui_u2.ui_addr.ui_db[0] = ufsi->i_u1.u2_i_data[0];
        } else if (inode->i_blocks) {
                memcpy(&ufs_inode->ui_u2.ui_addr, ufsi->i_u1.u2_i_data,
                       sizeof(ufs_inode->ui_u2.ui_addr));
        } else {
                memcpy(&ufs_inode->ui_u2.ui_symlink, ufsi->i_u1.i_symlink,
                       sizeof(ufs_inode->ui_u2.ui_symlink));
        }

        if (!inode->i_nlink)
                memset (ufs_inode, 0, sizeof(struct ufs2_inode));
        UFSD("EXIT\n");
}

static int ufs_update_inode(struct inode * inode, int do_sync)
{
        struct super_block *sb = inode->i_sb;
        struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
        struct buffer_head * bh;

        UFSD("ENTER, ino %lu\n", inode->i_ino);

        if (inode->i_ino < UFS_ROOTINO ||
            inode->i_ino > (uspi->s_ncg * uspi->s_ipg)) {
                ufs_warning (sb, "ufs_read_inode", "bad inode number (%lu)\n", inode->i_ino);
                return -1;
        }

        bh = sb_bread(sb, ufs_inotofsba(inode->i_ino));
        if (!bh) {
                ufs_warning (sb, "ufs_read_inode", "unable to read inode %lu\n", inode->i_ino);
                return -1;
        }
        if (uspi->fs_magic == UFS2_MAGIC) {
                struct ufs2_inode *ufs2_inode = (struct ufs2_inode *)bh->b_data;

                ufs2_update_inode(inode,
                                  ufs2_inode + ufs_inotofsbo(inode->i_ino));
        } else {
                struct ufs_inode *ufs_inode = (struct ufs_inode *) bh->b_data;

                ufs1_update_inode(inode, ufs_inode + ufs_inotofsbo(inode->i_ino));
        }

        mark_buffer_dirty(bh);
        if (do_sync)
                sync_dirty_buffer(bh);
        brelse (bh);

        UFSD("EXIT\n");
        return 0;
}

int ufs_write_inode(struct inode *inode, struct writeback_control *wbc)
{
        return ufs_update_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
}

int ufs_sync_inode (struct inode *inode)
{
        return ufs_update_inode (inode, 1);
}

void ufs_evict_inode(struct inode * inode)
{
        int want_delete = 0;

        if (!inode->i_nlink && !is_bad_inode(inode))
                want_delete = 1;

        truncate_inode_pages_final(&inode->i_data);
        if (want_delete) {
                inode->i_size = 0;
                if (inode->i_blocks)
                        ufs_truncate_blocks(inode);
        }

        invalidate_inode_buffers(inode);
        clear_inode(inode);

        if (want_delete)
                ufs_free_inode(inode);
}

struct to_free {
        struct inode *inode;
        u64 to;
        unsigned count;
};

static inline void free_data(struct to_free *ctx, u64 from, unsigned count)
{
        if (ctx->count && ctx->to != from) {
                ufs_free_blocks(ctx->inode, ctx->to - ctx->count, ctx->count);
                ctx->count = 0;
        }
        ctx->count += count;
        ctx->to = from + count;
}

#define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
#define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)

static void ufs_trunc_direct(struct inode *inode)
{
        struct ufs_inode_info *ufsi = UFS_I(inode);
        struct super_block * sb;
        struct ufs_sb_private_info * uspi;
        void *p;
        u64 frag1, frag2, frag3, frag4, block1, block2;
        struct to_free ctx = {.inode = inode};
        unsigned i, tmp;

        UFSD("ENTER: ino %lu\n", inode->i_ino);

        sb = inode->i_sb;
        uspi = UFS_SB(sb)->s_uspi;

        frag1 = DIRECT_FRAGMENT;
        frag4 = min_t(u64, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag);
        frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 | uspi->s_fpbmask) + 1) : frag1);
        frag3 = frag4 & ~uspi->s_fpbmask;
        block1 = block2 = 0;
        if (frag2 > frag3) {
                frag2 = frag4;
                frag3 = frag4 = 0;
        } else if (frag2 < frag3) {
                block1 = ufs_fragstoblks (frag2);
                block2 = ufs_fragstoblks (frag3);
        }

        UFSD("ino %lu, frag1 %llu, frag2 %llu, block1 %llu, block2 %llu,"
             " frag3 %llu, frag4 %llu\n", inode->i_ino,
             (unsigned long long)frag1, (unsigned long long)frag2,
             (unsigned long long)block1, (unsigned long long)block2,
             (unsigned long long)frag3, (unsigned long long)frag4);

        if (frag1 >= frag2)
                goto next1;

        /*
         * Free first free fragments
         */
        p = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag1));
        tmp = ufs_data_ptr_to_cpu(sb, p);
        if (!tmp )
                ufs_panic (sb, "ufs_trunc_direct", "internal error");
        frag2 -= frag1;
        frag1 = ufs_fragnum (frag1);

        ufs_free_fragments(inode, tmp + frag1, frag2);

next1:
        /*
         * Free whole blocks
         */
        for (i = block1 ; i < block2; i++) {
                p = ufs_get_direct_data_ptr(uspi, ufsi, i);
                tmp = ufs_data_ptr_to_cpu(sb, p);
                if (!tmp)
                        continue;
                write_seqlock(&ufsi->meta_lock);
                ufs_data_ptr_clear(uspi, p);
                write_sequnlock(&ufsi->meta_lock);

                free_data(&ctx, tmp, uspi->s_fpb);
        }

        free_data(&ctx, 0, 0);

        if (frag3 >= frag4)
                goto next3;

        /*
         * Free last free fragments
         */
        p = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag3));
        tmp = ufs_data_ptr_to_cpu(sb, p);
        if (!tmp )
                ufs_panic(sb, "ufs_truncate_direct", "internal error");
        frag4 = ufs_fragnum (frag4);
        write_seqlock(&ufsi->meta_lock);
        ufs_data_ptr_clear(uspi, p);
        write_sequnlock(&ufsi->meta_lock);

        ufs_free_fragments (inode, tmp, frag4);
 next3:

        UFSD("EXIT: ino %lu\n", inode->i_ino);
}

static void free_full_branch(struct inode *inode, u64 ind_block, int depth)
{
        struct super_block *sb = inode->i_sb;
        struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
        struct ufs_buffer_head *ubh = ubh_bread(sb, ind_block, uspi->s_bsize);
        unsigned i;

        if (!ubh)
                return;

        if (--depth) {
                for (i = 0; i < uspi->s_apb; i++) {
                        void *p = ubh_get_data_ptr(uspi, ubh, i);
                        u64 block = ufs_data_ptr_to_cpu(sb, p);
                        if (block)
                                free_full_branch(inode, block, depth);
                }
        } else {
                struct to_free ctx = {.inode = inode};

                for (i = 0; i < uspi->s_apb; i++) {
                        void *p = ubh_get_data_ptr(uspi, ubh, i);
                        u64 block = ufs_data_ptr_to_cpu(sb, p);
                        if (block)
                                free_data(&ctx, block, uspi->s_fpb);
                }
                free_data(&ctx, 0, 0);
        }

        ubh_bforget(ubh);
        ufs_free_blocks(inode, ind_block, uspi->s_fpb);
}

static void free_branch_tail(struct inode *inode, unsigned from, struct ufs_buffer_head *ubh, int depth)
{
        struct super_block *sb = inode->i_sb;
        struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
        unsigned i;

        if (--depth) {
                for (i = from; i < uspi->s_apb ; i++) {
                        void *p = ubh_get_data_ptr(uspi, ubh, i);
                        u64 block = ufs_data_ptr_to_cpu(sb, p);
                        if (block) {
                                write_seqlock(&UFS_I(inode)->meta_lock);
                                ufs_data_ptr_clear(uspi, p);
                                write_sequnlock(&UFS_I(inode)->meta_lock);
                                ubh_mark_buffer_dirty(ubh);
                                free_full_branch(inode, block, depth);
                        }
                }
        } else {
                struct to_free ctx = {.inode = inode};

                for (i = from; i < uspi->s_apb; i++) {
                        void *p = ubh_get_data_ptr(uspi, ubh, i);
                        u64 block = ufs_data_ptr_to_cpu(sb, p);
                        if (block) {
                                write_seqlock(&UFS_I(inode)->meta_lock);
                                ufs_data_ptr_clear(uspi, p);
                                write_sequnlock(&UFS_I(inode)->meta_lock);
                                ubh_mark_buffer_dirty(ubh);
                                free_data(&ctx, block, uspi->s_fpb);
                        }
                }
                free_data(&ctx, 0, 0);
        }
        if (IS_SYNC(inode) && ubh_buffer_dirty(ubh))
                ubh_sync_block(ubh);
        ubh_brelse(ubh);
}

static int ufs_alloc_lastblock(struct inode *inode, loff_t size)
{
        int err = 0;
        struct super_block *sb = inode->i_sb;
        struct address_space *mapping = inode->i_mapping;
        struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
        unsigned i, end;
        sector_t lastfrag;
        struct page *lastpage;
        struct buffer_head *bh;
        u64 phys64;

        lastfrag = (size + uspi->s_fsize - 1) >> uspi->s_fshift;

        if (!lastfrag)
                goto out;

        lastfrag--;

        lastpage = ufs_get_locked_page(mapping, lastfrag >>
                                       (PAGE_SHIFT - inode->i_blkbits));
       if (IS_ERR(lastpage)) {
               err = -EIO;
               goto out;
       }

       end = lastfrag & ((1 << (PAGE_SHIFT - inode->i_blkbits)) - 1);
       bh = page_buffers(lastpage);
       for (i = 0; i < end; ++i)
               bh = bh->b_this_page;


       err = ufs_getfrag_block(inode, lastfrag, bh, 1);

       if (unlikely(err))
               goto out_unlock;

       if (buffer_new(bh)) {
               clear_buffer_new(bh);
               clean_bdev_bh_alias(bh);
               /*
                * we do not zeroize fragment, because of
                * if it maped to hole, it already contains zeroes
                */
               set_buffer_uptodate(bh);
               mark_buffer_dirty(bh);
               set_page_dirty(lastpage);
       }

       if (lastfrag >= UFS_IND_FRAGMENT) {
               end = uspi->s_fpb - ufs_fragnum(lastfrag) - 1;
               phys64 = bh->b_blocknr + 1;
               for (i = 0; i < end; ++i) {
                       bh = sb_getblk(sb, i + phys64);
                       lock_buffer(bh);
                       memset(bh->b_data, 0, sb->s_blocksize);
                       set_buffer_uptodate(bh);
                       mark_buffer_dirty(bh);
                       unlock_buffer(bh);
                       sync_dirty_buffer(bh);
                       brelse(bh);
               }
       }
out_unlock:
       ufs_put_locked_page(lastpage);
out:
       return err;
}

static void __ufs_truncate_blocks(struct inode *inode)
{
        struct ufs_inode_info *ufsi = UFS_I(inode);
        struct super_block *sb = inode->i_sb;
        struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
        unsigned offsets[4];
        int depth = ufs_block_to_path(inode, DIRECT_BLOCK, offsets);
        int depth2;
        unsigned i;
        struct ufs_buffer_head *ubh[3];
        void *p;
        u64 block;

        if (!depth)
                return;

        /* find the last non-zero in offsets[] */
        for (depth2 = depth - 1; depth2; depth2--)
                if (offsets[depth2])
                        break;

        mutex_lock(&ufsi->truncate_mutex);
        if (depth == 1) {
                ufs_trunc_direct(inode);
                offsets[0] = UFS_IND_BLOCK;
        } else {
                /* get the blocks that should be partially emptied */
                p = ufs_get_direct_data_ptr(uspi, ufsi, offsets[0]);
                for (i = 0; i < depth2; i++) {
                        offsets[i]++;   /* next branch is fully freed */
                        block = ufs_data_ptr_to_cpu(sb, p);
                        if (!block)
                                break;
                        ubh[i] = ubh_bread(sb, block, uspi->s_bsize);
                        if (!ubh[i]) {
                                write_seqlock(&ufsi->meta_lock);
                                ufs_data_ptr_clear(uspi, p);
                                write_sequnlock(&ufsi->meta_lock);
                                break;
                        }
                        p = ubh_get_data_ptr(uspi, ubh[i], offsets[i + 1]);
                }
                while (i--)
                        free_branch_tail(inode, offsets[i + 1], ubh[i], depth - i - 1);
        }
        for (i = offsets[0]; i <= UFS_TIND_BLOCK; i++) {
                p = ufs_get_direct_data_ptr(uspi, ufsi, i);
                block = ufs_data_ptr_to_cpu(sb, p);
                if (block) {
                        write_seqlock(&ufsi->meta_lock);
                        ufs_data_ptr_clear(uspi, p);
                        write_sequnlock(&ufsi->meta_lock);
                        free_full_branch(inode, block, i - UFS_IND_BLOCK + 1);
                }
        }
        ufsi->i_lastfrag = DIRECT_FRAGMENT;
        mark_inode_dirty(inode);
        mutex_unlock(&ufsi->truncate_mutex);
}

static int ufs_truncate(struct inode *inode, loff_t size)
{
        int err = 0;

        UFSD("ENTER: ino %lu, i_size: %llu, old_i_size: %llu\n",
             inode->i_ino, (unsigned long long)size,
             (unsigned long long)i_size_read(inode));

        if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
              S_ISLNK(inode->i_mode)))
                return -EINVAL;
        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
                return -EPERM;

        err = ufs_alloc_lastblock(inode, size);

        if (err)
                goto out;

        block_truncate_page(inode->i_mapping, size, ufs_getfrag_block);

        truncate_setsize(inode, size);

        __ufs_truncate_blocks(inode);
        inode->i_mtime = inode->i_ctime = current_time(inode);
        mark_inode_dirty(inode);
out:
        UFSD("EXIT: err %d\n", err);
        return err;
}

static void ufs_truncate_blocks(struct inode *inode)
{
        if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
              S_ISLNK(inode->i_mode)))
                return;
        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
                return;
        __ufs_truncate_blocks(inode);
}

int ufs_setattr(struct dentry *dentry, struct iattr *attr)
{
        struct inode *inode = d_inode(dentry);
        unsigned int ia_valid = attr->ia_valid;
        int error;

        error = setattr_prepare(dentry, attr);
        if (error)
                return error;

        if (ia_valid & ATTR_SIZE && attr->ia_size != inode->i_size) {
                error = ufs_truncate(inode, attr->ia_size);
                if (error)
                        return error;
        }

        setattr_copy(inode, attr);
        mark_inode_dirty(inode);
        return 0;
}

const struct inode_operations ufs_file_inode_operations = {
        .setattr = ufs_setattr,
};