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![Christian Brauner](/assets/img/avatar_default.png)
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>
318 lines
8.9 KiB
C
318 lines
8.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/hpfs/inode.c
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*
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* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
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*
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* inode VFS functions
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*/
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#include <linux/slab.h>
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#include <linux/user_namespace.h>
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#include "hpfs_fn.h"
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void hpfs_init_inode(struct inode *i)
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{
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struct super_block *sb = i->i_sb;
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struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
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i->i_uid = hpfs_sb(sb)->sb_uid;
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i->i_gid = hpfs_sb(sb)->sb_gid;
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i->i_mode = hpfs_sb(sb)->sb_mode;
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i->i_size = -1;
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i->i_blocks = -1;
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hpfs_inode->i_dno = 0;
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hpfs_inode->i_n_secs = 0;
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hpfs_inode->i_file_sec = 0;
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hpfs_inode->i_disk_sec = 0;
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hpfs_inode->i_dpos = 0;
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hpfs_inode->i_dsubdno = 0;
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hpfs_inode->i_ea_mode = 0;
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hpfs_inode->i_ea_uid = 0;
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hpfs_inode->i_ea_gid = 0;
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hpfs_inode->i_ea_size = 0;
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hpfs_inode->i_rddir_off = NULL;
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hpfs_inode->i_dirty = 0;
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i->i_ctime.tv_sec = i->i_ctime.tv_nsec = 0;
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i->i_mtime.tv_sec = i->i_mtime.tv_nsec = 0;
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i->i_atime.tv_sec = i->i_atime.tv_nsec = 0;
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}
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void hpfs_read_inode(struct inode *i)
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{
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struct buffer_head *bh;
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struct fnode *fnode;
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struct super_block *sb = i->i_sb;
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struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
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void *ea;
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int ea_size;
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if (!(fnode = hpfs_map_fnode(sb, i->i_ino, &bh))) {
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/*i->i_mode |= S_IFREG;
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i->i_mode &= ~0111;
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i->i_op = &hpfs_file_iops;
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i->i_fop = &hpfs_file_ops;
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clear_nlink(i);*/
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make_bad_inode(i);
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return;
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}
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if (hpfs_sb(i->i_sb)->sb_eas) {
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if ((ea = hpfs_get_ea(i->i_sb, fnode, "UID", &ea_size))) {
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if (ea_size == 2) {
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i_uid_write(i, le16_to_cpu(*(__le16*)ea));
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hpfs_inode->i_ea_uid = 1;
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}
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kfree(ea);
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}
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if ((ea = hpfs_get_ea(i->i_sb, fnode, "GID", &ea_size))) {
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if (ea_size == 2) {
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i_gid_write(i, le16_to_cpu(*(__le16*)ea));
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hpfs_inode->i_ea_gid = 1;
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}
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kfree(ea);
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}
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if ((ea = hpfs_get_ea(i->i_sb, fnode, "SYMLINK", &ea_size))) {
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kfree(ea);
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i->i_mode = S_IFLNK | 0777;
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i->i_op = &page_symlink_inode_operations;
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inode_nohighmem(i);
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i->i_data.a_ops = &hpfs_symlink_aops;
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set_nlink(i, 1);
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i->i_size = ea_size;
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i->i_blocks = 1;
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brelse(bh);
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return;
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}
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if ((ea = hpfs_get_ea(i->i_sb, fnode, "MODE", &ea_size))) {
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int rdev = 0;
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umode_t mode = hpfs_sb(sb)->sb_mode;
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if (ea_size == 2) {
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mode = le16_to_cpu(*(__le16*)ea);
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hpfs_inode->i_ea_mode = 1;
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}
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kfree(ea);
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i->i_mode = mode;
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if (S_ISBLK(mode) || S_ISCHR(mode)) {
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if ((ea = hpfs_get_ea(i->i_sb, fnode, "DEV", &ea_size))) {
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if (ea_size == 4)
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rdev = le32_to_cpu(*(__le32*)ea);
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kfree(ea);
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}
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}
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if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
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brelse(bh);
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set_nlink(i, 1);
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i->i_size = 0;
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i->i_blocks = 1;
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init_special_inode(i, mode,
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new_decode_dev(rdev));
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return;
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}
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}
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}
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if (fnode_is_dir(fnode)) {
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int n_dnodes, n_subdirs;
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i->i_mode |= S_IFDIR;
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i->i_op = &hpfs_dir_iops;
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i->i_fop = &hpfs_dir_ops;
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hpfs_inode->i_parent_dir = le32_to_cpu(fnode->up);
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hpfs_inode->i_dno = le32_to_cpu(fnode->u.external[0].disk_secno);
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if (hpfs_sb(sb)->sb_chk >= 2) {
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struct buffer_head *bh0;
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if (hpfs_map_fnode(sb, hpfs_inode->i_parent_dir, &bh0)) brelse(bh0);
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}
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n_dnodes = 0; n_subdirs = 0;
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hpfs_count_dnodes(i->i_sb, hpfs_inode->i_dno, &n_dnodes, &n_subdirs, NULL);
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i->i_blocks = 4 * n_dnodes;
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i->i_size = 2048 * n_dnodes;
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set_nlink(i, 2 + n_subdirs);
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} else {
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i->i_mode |= S_IFREG;
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if (!hpfs_inode->i_ea_mode) i->i_mode &= ~0111;
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i->i_op = &hpfs_file_iops;
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i->i_fop = &hpfs_file_ops;
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set_nlink(i, 1);
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i->i_size = le32_to_cpu(fnode->file_size);
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i->i_blocks = ((i->i_size + 511) >> 9) + 1;
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i->i_data.a_ops = &hpfs_aops;
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hpfs_i(i)->mmu_private = i->i_size;
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}
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brelse(bh);
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}
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static void hpfs_write_inode_ea(struct inode *i, struct fnode *fnode)
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{
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struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
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/*if (le32_to_cpu(fnode->acl_size_l) || le16_to_cpu(fnode->acl_size_s)) {
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Some unknown structures like ACL may be in fnode,
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we'd better not overwrite them
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hpfs_error(i->i_sb, "fnode %08x has some unknown HPFS386 structures", i->i_ino);
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} else*/ if (hpfs_sb(i->i_sb)->sb_eas >= 2) {
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__le32 ea;
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if (!uid_eq(i->i_uid, hpfs_sb(i->i_sb)->sb_uid) || hpfs_inode->i_ea_uid) {
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ea = cpu_to_le32(i_uid_read(i));
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hpfs_set_ea(i, fnode, "UID", (char*)&ea, 2);
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hpfs_inode->i_ea_uid = 1;
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}
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if (!gid_eq(i->i_gid, hpfs_sb(i->i_sb)->sb_gid) || hpfs_inode->i_ea_gid) {
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ea = cpu_to_le32(i_gid_read(i));
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hpfs_set_ea(i, fnode, "GID", (char *)&ea, 2);
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hpfs_inode->i_ea_gid = 1;
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}
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if (!S_ISLNK(i->i_mode))
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if ((i->i_mode != ((hpfs_sb(i->i_sb)->sb_mode & ~(S_ISDIR(i->i_mode) ? 0 : 0111))
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| (S_ISDIR(i->i_mode) ? S_IFDIR : S_IFREG))
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&& i->i_mode != ((hpfs_sb(i->i_sb)->sb_mode & ~(S_ISDIR(i->i_mode) ? 0222 : 0333))
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| (S_ISDIR(i->i_mode) ? S_IFDIR : S_IFREG))) || hpfs_inode->i_ea_mode) {
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ea = cpu_to_le32(i->i_mode);
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/* sick, but legal */
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hpfs_set_ea(i, fnode, "MODE", (char *)&ea, 2);
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hpfs_inode->i_ea_mode = 1;
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}
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if (S_ISBLK(i->i_mode) || S_ISCHR(i->i_mode)) {
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ea = cpu_to_le32(new_encode_dev(i->i_rdev));
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hpfs_set_ea(i, fnode, "DEV", (char *)&ea, 4);
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}
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}
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}
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void hpfs_write_inode(struct inode *i)
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{
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struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
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struct inode *parent;
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if (i->i_ino == hpfs_sb(i->i_sb)->sb_root) return;
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if (hpfs_inode->i_rddir_off && !atomic_read(&i->i_count)) {
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if (*hpfs_inode->i_rddir_off)
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pr_err("write_inode: some position still there\n");
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kfree(hpfs_inode->i_rddir_off);
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hpfs_inode->i_rddir_off = NULL;
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}
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if (!i->i_nlink) {
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return;
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}
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parent = iget_locked(i->i_sb, hpfs_inode->i_parent_dir);
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if (parent) {
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hpfs_inode->i_dirty = 0;
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if (parent->i_state & I_NEW) {
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hpfs_init_inode(parent);
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hpfs_read_inode(parent);
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unlock_new_inode(parent);
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}
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hpfs_write_inode_nolock(i);
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iput(parent);
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}
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}
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void hpfs_write_inode_nolock(struct inode *i)
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{
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struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
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struct buffer_head *bh;
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struct fnode *fnode;
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struct quad_buffer_head qbh;
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struct hpfs_dirent *de;
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if (i->i_ino == hpfs_sb(i->i_sb)->sb_root) return;
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if (!(fnode = hpfs_map_fnode(i->i_sb, i->i_ino, &bh))) return;
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if (i->i_ino != hpfs_sb(i->i_sb)->sb_root && i->i_nlink) {
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if (!(de = map_fnode_dirent(i->i_sb, i->i_ino, fnode, &qbh))) {
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brelse(bh);
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return;
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}
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} else de = NULL;
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if (S_ISREG(i->i_mode)) {
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fnode->file_size = cpu_to_le32(i->i_size);
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if (de) de->file_size = cpu_to_le32(i->i_size);
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} else if (S_ISDIR(i->i_mode)) {
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fnode->file_size = cpu_to_le32(0);
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if (de) de->file_size = cpu_to_le32(0);
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}
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hpfs_write_inode_ea(i, fnode);
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if (de) {
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de->write_date = cpu_to_le32(gmt_to_local(i->i_sb, i->i_mtime.tv_sec));
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de->read_date = cpu_to_le32(gmt_to_local(i->i_sb, i->i_atime.tv_sec));
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de->creation_date = cpu_to_le32(gmt_to_local(i->i_sb, i->i_ctime.tv_sec));
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de->read_only = !(i->i_mode & 0222);
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de->ea_size = cpu_to_le32(hpfs_inode->i_ea_size);
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hpfs_mark_4buffers_dirty(&qbh);
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hpfs_brelse4(&qbh);
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}
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if (S_ISDIR(i->i_mode)) {
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if ((de = map_dirent(i, hpfs_inode->i_dno, "\001\001", 2, NULL, &qbh))) {
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de->write_date = cpu_to_le32(gmt_to_local(i->i_sb, i->i_mtime.tv_sec));
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de->read_date = cpu_to_le32(gmt_to_local(i->i_sb, i->i_atime.tv_sec));
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de->creation_date = cpu_to_le32(gmt_to_local(i->i_sb, i->i_ctime.tv_sec));
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de->read_only = !(i->i_mode & 0222);
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de->ea_size = cpu_to_le32(/*hpfs_inode->i_ea_size*/0);
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de->file_size = cpu_to_le32(0);
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hpfs_mark_4buffers_dirty(&qbh);
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hpfs_brelse4(&qbh);
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} else
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hpfs_error(i->i_sb,
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"directory %08lx doesn't have '.' entry",
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(unsigned long)i->i_ino);
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}
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mark_buffer_dirty(bh);
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brelse(bh);
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}
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int hpfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
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struct iattr *attr)
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{
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struct inode *inode = d_inode(dentry);
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int error = -EINVAL;
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hpfs_lock(inode->i_sb);
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if (inode->i_ino == hpfs_sb(inode->i_sb)->sb_root)
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goto out_unlock;
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if ((attr->ia_valid & ATTR_UID) &&
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from_kuid(&init_user_ns, attr->ia_uid) >= 0x10000)
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goto out_unlock;
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if ((attr->ia_valid & ATTR_GID) &&
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from_kgid(&init_user_ns, attr->ia_gid) >= 0x10000)
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goto out_unlock;
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if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size > inode->i_size)
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goto out_unlock;
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error = setattr_prepare(&init_user_ns, dentry, attr);
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if (error)
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goto out_unlock;
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if ((attr->ia_valid & ATTR_SIZE) &&
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attr->ia_size != i_size_read(inode)) {
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error = inode_newsize_ok(inode, attr->ia_size);
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if (error)
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goto out_unlock;
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truncate_setsize(inode, attr->ia_size);
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hpfs_truncate(inode);
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}
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setattr_copy(&init_user_ns, inode, attr);
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hpfs_write_inode(inode);
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out_unlock:
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hpfs_unlock(inode->i_sb);
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return error;
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}
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void hpfs_write_if_changed(struct inode *inode)
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{
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struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
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if (hpfs_inode->i_dirty)
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hpfs_write_inode(inode);
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}
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void hpfs_evict_inode(struct inode *inode)
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{
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truncate_inode_pages_final(&inode->i_data);
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clear_inode(inode);
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if (!inode->i_nlink) {
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hpfs_lock(inode->i_sb);
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hpfs_remove_fnode(inode->i_sb, inode->i_ino);
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hpfs_unlock(inode->i_sb);
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}
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}
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