inode.c

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/*
 *  linux/fs/hpfs/inode.c
 *
 *  Mikulas Patocka ([email protected]), 1998-1999
 *
 *  inode VFS functions
 */

#include <linux/slab.h>
#include <linux/user_namespace.h>
#include "hpfs_fn.h"

void hpfs_init_inode(struct inode *i)
{
    struct super_block *sb = i->i_sb;
    struct hpfs_inode_info *hpfs_inode = hpfs_i(i);

    i->i_uid = hpfs_sb(sb)->sb_uid;
    i->i_gid = hpfs_sb(sb)->sb_gid;
    i->i_mode = hpfs_sb(sb)->sb_mode;
    i->i_size = -1;
    i->i_blocks = -1;
    
    hpfs_inode->i_dno = 0;
    hpfs_inode->i_n_secs = 0;
    hpfs_inode->i_file_sec = 0;
    hpfs_inode->i_disk_sec = 0;
    hpfs_inode->i_dpos = 0;
    hpfs_inode->i_dsubdno = 0;
    hpfs_inode->i_ea_mode = 0;
    hpfs_inode->i_ea_uid = 0;
    hpfs_inode->i_ea_gid = 0;
    hpfs_inode->i_ea_size = 0;

    hpfs_inode->i_rddir_off = NULL;
    hpfs_inode->i_dirty = 0;

    i->i_ctime.tv_sec = i->i_ctime.tv_nsec = 0;
    i->i_mtime.tv_sec = i->i_mtime.tv_nsec = 0;
    i->i_atime.tv_sec = i->i_atime.tv_nsec = 0;
}

void hpfs_read_inode(struct inode *i)
{
    struct buffer_head *bh;
    struct fnode *fnode;
    struct super_block *sb = i->i_sb;
    struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
    void *ea;
    int ea_size;

    if (!(fnode = hpfs_map_fnode(sb, i->i_ino, &bh))) {
        /*i->i_mode |= S_IFREG;
        i->i_mode &= ~0111;
        i->i_op = &hpfs_file_iops;
        i->i_fop = &hpfs_file_ops;
        clear_nlink(i);*/
        make_bad_inode(i);
        return;
    }
    if (hpfs_sb(i->i_sb)->sb_eas) {
        if ((ea = hpfs_get_ea(i->i_sb, fnode, "UID", &ea_size))) {
            if (ea_size == 2) {
                i_uid_write(i, le16_to_cpu(*(__le16*)ea));
                hpfs_inode->i_ea_uid = 1;
            }
            kfree(ea);
        }
        if ((ea = hpfs_get_ea(i->i_sb, fnode, "GID", &ea_size))) {
            if (ea_size == 2) {
                i_gid_write(i, le16_to_cpu(*(__le16*)ea));
                hpfs_inode->i_ea_gid = 1;
            }
            kfree(ea);
        }
        if ((ea = hpfs_get_ea(i->i_sb, fnode, "SYMLINK", &ea_size))) {
            kfree(ea);
            i->i_mode = S_IFLNK | 0777;
            i->i_op = &page_symlink_inode_operations;
            i->i_data.a_ops = &hpfs_symlink_aops;
            set_nlink(i, 1);
            i->i_size = ea_size;
            i->i_blocks = 1;
            brelse(bh);
            return;
        }
        if ((ea = hpfs_get_ea(i->i_sb, fnode, "MODE", &ea_size))) {
            int rdev = 0;
            umode_t mode = hpfs_sb(sb)->sb_mode;
            if (ea_size == 2) {
                mode = le16_to_cpu(*(__le16*)ea);
                hpfs_inode->i_ea_mode = 1;
            }
            kfree(ea);
            i->i_mode = mode;
            if (S_ISBLK(mode) || S_ISCHR(mode)) {
                if ((ea = hpfs_get_ea(i->i_sb, fnode, "DEV", &ea_size))) {
                    if (ea_size == 4)
                        rdev = le32_to_cpu(*(__le32*)ea);
                    kfree(ea);
                }
            }
            if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
                brelse(bh);
                set_nlink(i, 1);
                i->i_size = 0;
                i->i_blocks = 1;
                init_special_inode(i, mode,
                    new_decode_dev(rdev));
                return;
            }
        }
    }
    if (fnode_is_dir(fnode)) {
        int n_dnodes, n_subdirs;
        i->i_mode |= S_IFDIR;
        i->i_op = &hpfs_dir_iops;
        i->i_fop = &hpfs_dir_ops;
        hpfs_inode->i_parent_dir = le32_to_cpu(fnode->up);
        hpfs_inode->i_dno = le32_to_cpu(fnode->u.external[0].disk_secno);
        if (hpfs_sb(sb)->sb_chk >= 2) {
            struct buffer_head *bh0;
            if (hpfs_map_fnode(sb, hpfs_inode->i_parent_dir, &bh0)) brelse(bh0);
        }
        n_dnodes = 0; n_subdirs = 0;
        hpfs_count_dnodes(i->i_sb, hpfs_inode->i_dno, &n_dnodes, &n_subdirs, NULL);
        i->i_blocks = 4 * n_dnodes;
        i->i_size = 2048 * n_dnodes;
        set_nlink(i, 2 + n_subdirs);
    } else {
        i->i_mode |= S_IFREG;
        if (!hpfs_inode->i_ea_mode) i->i_mode &= ~0111;
        i->i_op = &hpfs_file_iops;
        i->i_fop = &hpfs_file_ops;
        set_nlink(i, 1);
        i->i_size = le32_to_cpu(fnode->file_size);
        i->i_blocks = ((i->i_size + 511) >> 9) + 1;
        i->i_data.a_ops = &hpfs_aops;
        hpfs_i(i)->mmu_private = i->i_size;
    }
    brelse(bh);
}

static void hpfs_write_inode_ea(struct inode *i, struct fnode *fnode)
{
    struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
    /*if (le32_to_cpu(fnode->acl_size_l) || le16_to_cpu(fnode->acl_size_s)) {
           Some unknown structures like ACL may be in fnode,
           we'd better not overwrite them
        hpfs_error(i->i_sb, "fnode %08x has some unknown HPFS386 stuctures", i->i_ino);
    } else*/ if (hpfs_sb(i->i_sb)->sb_eas >= 2) {
        __le32 ea;
        if (!uid_eq(i->i_uid, hpfs_sb(i->i_sb)->sb_uid) || hpfs_inode->i_ea_uid) {
            ea = cpu_to_le32(i_uid_read(i));
            hpfs_set_ea(i, fnode, "UID", (char*)&ea, 2);
            hpfs_inode->i_ea_uid = 1;
        }
        if (!gid_eq(i->i_gid, hpfs_sb(i->i_sb)->sb_gid) || hpfs_inode->i_ea_gid) {
            ea = cpu_to_le32(i_gid_read(i));
            hpfs_set_ea(i, fnode, "GID", (char *)&ea, 2);
            hpfs_inode->i_ea_gid = 1;
        }
        if (!S_ISLNK(i->i_mode))
            if ((i->i_mode != ((hpfs_sb(i->i_sb)->sb_mode & ~(S_ISDIR(i->i_mode) ? 0 : 0111))
              | (S_ISDIR(i->i_mode) ? S_IFDIR : S_IFREG))
              && i->i_mode != ((hpfs_sb(i->i_sb)->sb_mode & ~(S_ISDIR(i->i_mode) ? 0222 : 0333))
              | (S_ISDIR(i->i_mode) ? S_IFDIR : S_IFREG))) || hpfs_inode->i_ea_mode) {
                ea = cpu_to_le32(i->i_mode);
                /* sick, but legal */
                hpfs_set_ea(i, fnode, "MODE", (char *)&ea, 2);
                hpfs_inode->i_ea_mode = 1;
            }
        if (S_ISBLK(i->i_mode) || S_ISCHR(i->i_mode)) {
            ea = cpu_to_le32(new_encode_dev(i->i_rdev));
            hpfs_set_ea(i, fnode, "DEV", (char *)&ea, 4);
        }
    }
}

void hpfs_write_inode(struct inode *i)
{
    struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
    struct inode *parent;
    if (i->i_ino == hpfs_sb(i->i_sb)->sb_root) return;
    if (hpfs_inode->i_rddir_off && !atomic_read(&i->i_count)) {
        if (*hpfs_inode->i_rddir_off) printk("HPFS: write_inode: some position still there\n");
        kfree(hpfs_inode->i_rddir_off);
        hpfs_inode->i_rddir_off = NULL;
    }
    if (!i->i_nlink) {
        return;
    }
    parent = iget_locked(i->i_sb, hpfs_inode->i_parent_dir);
    if (parent) {
        hpfs_inode->i_dirty = 0;
        if (parent->i_state & I_NEW) {
            hpfs_init_inode(parent);
            hpfs_read_inode(parent);
            unlock_new_inode(parent);
        }
        hpfs_write_inode_nolock(i);
        iput(parent);
    }
}

void hpfs_write_inode_nolock(struct inode *i)
{
    struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
    struct buffer_head *bh;
    struct fnode *fnode;
    struct quad_buffer_head qbh;
    struct hpfs_dirent *de;
    if (i->i_ino == hpfs_sb(i->i_sb)->sb_root) return;
    if (!(fnode = hpfs_map_fnode(i->i_sb, i->i_ino, &bh))) return;
    if (i->i_ino != hpfs_sb(i->i_sb)->sb_root && i->i_nlink) {
        if (!(de = map_fnode_dirent(i->i_sb, i->i_ino, fnode, &qbh))) {
            brelse(bh);
            return;
        }
    } else de = NULL;
    if (S_ISREG(i->i_mode)) {
        fnode->file_size = cpu_to_le32(i->i_size);
        if (de) de->file_size = cpu_to_le32(i->i_size);
    } else if (S_ISDIR(i->i_mode)) {
        fnode->file_size = cpu_to_le32(0);
        if (de) de->file_size = cpu_to_le32(0);
    }
    hpfs_write_inode_ea(i, fnode);
    if (de) {
        de->write_date = cpu_to_le32(gmt_to_local(i->i_sb, i->i_mtime.tv_sec));
        de->read_date = cpu_to_le32(gmt_to_local(i->i_sb, i->i_atime.tv_sec));
        de->creation_date = cpu_to_le32(gmt_to_local(i->i_sb, i->i_ctime.tv_sec));
        de->read_only = !(i->i_mode & 0222);
        de->ea_size = cpu_to_le32(hpfs_inode->i_ea_size);
        hpfs_mark_4buffers_dirty(&qbh);
        hpfs_brelse4(&qbh);
    }
    if (S_ISDIR(i->i_mode)) {
        if ((de = map_dirent(i, hpfs_inode->i_dno, "\001\001", 2, NULL, &qbh))) {
            de->write_date = cpu_to_le32(gmt_to_local(i->i_sb, i->i_mtime.tv_sec));
            de->read_date = cpu_to_le32(gmt_to_local(i->i_sb, i->i_atime.tv_sec));
            de->creation_date = cpu_to_le32(gmt_to_local(i->i_sb, i->i_ctime.tv_sec));
            de->read_only = !(i->i_mode & 0222);
            de->ea_size = cpu_to_le32(/*hpfs_inode->i_ea_size*/0);
            de->file_size = cpu_to_le32(0);
            hpfs_mark_4buffers_dirty(&qbh);
            hpfs_brelse4(&qbh);
        } else
            hpfs_error(i->i_sb,
                "directory %08lx doesn't have '.' entry",
                (unsigned long)i->i_ino);
    }
    mark_buffer_dirty(bh);
    brelse(bh);
}

int hpfs_setattr(struct dentry *dentry, struct iattr *attr)
{
    struct inode *inode = dentry->d_inode;
    int error = -EINVAL;

    hpfs_lock(inode->i_sb);
    if (inode->i_ino == hpfs_sb(inode->i_sb)->sb_root)
        goto out_unlock;
    if ((attr->ia_valid & ATTR_UID) &&
        from_kuid(&init_user_ns, attr->ia_uid) >= 0x10000)
        goto out_unlock;
    if ((attr->ia_valid & ATTR_GID) &&
        from_kgid(&init_user_ns, attr->ia_gid) >= 0x10000)
        goto out_unlock;
    if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size > inode->i_size)
        goto out_unlock;

    error = inode_change_ok(inode, attr);
    if (error)
        goto out_unlock;

    if ((attr->ia_valid & ATTR_SIZE) &&
        attr->ia_size != i_size_read(inode)) {
        error = vmtruncate(inode, attr->ia_size);
        if (error)
            goto out_unlock;
    }

    setattr_copy(inode, attr);

    hpfs_write_inode(inode);

 out_unlock:
    hpfs_unlock(inode->i_sb);
    return error;
}

void hpfs_write_if_changed(struct inode *inode)
{
    struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);

    if (hpfs_inode->i_dirty)
        hpfs_write_inode(inode);
}

void hpfs_evict_inode(struct inode *inode)
{
    truncate_inode_pages(&inode->i_data, 0);
    clear_inode(inode);
    if (!inode->i_nlink) {
        hpfs_lock(inode->i_sb);
        hpfs_remove_fnode(inode->i_sb, inode->i_ino);
        hpfs_unlock(inode->i_sb);
    }
}