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linux/fs/hpfs/inode.c
Christian Brauner 549c729771
fs: make helpers idmap mount aware 
Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:20 +01:00

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// 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;
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;
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 && !atomic_read(&i->i_count)) {
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 (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 user_namespace *mnt_userns, 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(&init_user_ns, 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(&init_user_ns, 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);
}
}
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