root/fs/hpfs/inode.c
// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/hpfs/inode.c
 *
 *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 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;

        inode_set_ctime(i, 0, 0);
        inode_set_mtime(i, 0, 0);
        inode_set_atime(i, 0, 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;
                        inode_nohighmem(i);
                        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 structures", 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 && !icount_read(i)) {
                if (*hpfs_inode->i_rddir_off)
                        pr_err("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 (inode_state_read_once(parent) & 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, inode_get_mtime_sec(i)));
                de->read_date = cpu_to_le32(gmt_to_local(i->i_sb, inode_get_atime_sec(i)));
                de->creation_date = cpu_to_le32(gmt_to_local(i->i_sb, inode_get_ctime_sec(i)));
                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, inode_get_mtime_sec(i)));
                        de->read_date = cpu_to_le32(gmt_to_local(i->i_sb, inode_get_atime_sec(i)));
                        de->creation_date = cpu_to_le32(gmt_to_local(i->i_sb, inode_get_ctime_sec(i)));
                        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 mnt_idmap *idmap, struct dentry *dentry,
                 struct iattr *attr)
{
        struct inode *inode = d_inode(dentry);
        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 = setattr_prepare(&nop_mnt_idmap, dentry, attr);
        if (error)
                goto out_unlock;

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

                truncate_setsize(inode, attr->ia_size);
                hpfs_truncate(inode);
        }

        setattr_copy(&nop_mnt_idmap, 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_final(&inode->i_data);
        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);
        }
}