fs/ntfs3/namei.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *
   4  * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
   5  *
   6  */
   7
   8 #include <linux/fs.h>
   9 #include <linux/nls.h>
  10
  11 #include "debug.h"
  12 #include "ntfs.h"
  13 #include "ntfs_fs.h"
  14
  15 /*
  16  * fill_name_de - Format NTFS_DE in @buf.
  17  */
  18 int fill_name_de(struct ntfs_sb_info *sbi, void *buf, const struct qstr *name,
  19                  const struct cpu_str *uni)
  20 {
  21         int err;
  22         struct NTFS_DE *e = buf;
  23         u16 data_size;
  24         struct ATTR_FILE_NAME *fname = (struct ATTR_FILE_NAME *)(e + 1);
  25
  26 #ifndef CONFIG_NTFS3_64BIT_CLUSTER
  27         e->ref.high = fname->home.high = 0;
  28 #endif
  29         if (uni) {
  30 #ifdef __BIG_ENDIAN
  31                 int ulen = uni->len;
  32                 __le16 *uname = fname->name;
  33                 const u16 *name_cpu = uni->name;
  34
  35                 while (ulen--)
  36                         *uname++ = cpu_to_le16(*name_cpu++);
  37 #else
  38                 memcpy(fname->name, uni->name, uni->len * sizeof(u16));
  39 #endif
  40                 fname->name_len = uni->len;
  41
  42         } else {
  43                 /* Convert input string to unicode. */
  44                 err = ntfs_nls_to_utf16(sbi, name->name, name->len,
  45                                         (struct cpu_str *)&fname->name_len,
  46                                         NTFS_NAME_LEN, UTF16_LITTLE_ENDIAN);
  47                 if (err < 0)
  48                         return err;
  49         }
  50
  51         fname->type = FILE_NAME_POSIX;
  52         data_size = fname_full_size(fname);
  53
  54         e->size = cpu_to_le16(ALIGN(data_size, 8) + sizeof(struct NTFS_DE));
  55         e->key_size = cpu_to_le16(data_size);
  56         e->flags = 0;
  57         e->res = 0;
  58
  59         return 0;
  60 }
  61
  62 /*
  63  * ntfs_lookup - inode_operations::lookup
  64  */
  65 static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
  66                                   u32 flags)
  67 {
  68         struct ntfs_inode *ni = ntfs_i(dir);
  69         struct cpu_str *uni = __getname();
  70         struct inode *inode;
  71         int err;
  72
  73         if (!uni)
  74                 inode = ERR_PTR(-ENOMEM);
  75         else {
  76                 err = ntfs_nls_to_utf16(ni->mi.sbi, dentry->d_name.name,
  77                                         dentry->d_name.len, uni, NTFS_NAME_LEN,
  78                                         UTF16_HOST_ENDIAN);
  79                 if (err < 0)
  80                         inode = ERR_PTR(err);
  81                 else {
  82                         ni_lock(ni);
  83                         inode = dir_search_u(dir, uni, NULL);
  84                         ni_unlock(ni);
  85                 }
  86                 __putname(uni);
  87         }
  88
  89         return d_splice_alias(inode, dentry);
  90 }
  91
  92 /*
  93  * ntfs_create - inode_operations::create
  94  */
  95 static int ntfs_create(struct user_namespace *mnt_userns, struct inode *dir,
  96                        struct dentry *dentry, umode_t mode, bool excl)
  97 {
  98         struct inode *inode;
  99
 100         inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFREG | mode,
 101                                   0, NULL, 0, NULL);
 102
 103         return IS_ERR(inode) ? PTR_ERR(inode) : 0;
 104 }
 105
 106 /*
 107  * ntfs_mknod
 108  *
 109  * inode_operations::mknod
 110  */
 111 static int ntfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 112                       struct dentry *dentry, umode_t mode, dev_t rdev)
 113 {
 114         struct inode *inode;
 115
 116         inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, mode, rdev,
 117                                   NULL, 0, NULL);
 118
 119         return IS_ERR(inode) ? PTR_ERR(inode) : 0;
 120 }
 121
 122 /*
 123  * ntfs_link - inode_operations::link
 124  */
 125 static int ntfs_link(struct dentry *ode, struct inode *dir, struct dentry *de)
 126 {
 127         int err;
 128         struct inode *inode = d_inode(ode);
 129         struct ntfs_inode *ni = ntfs_i(inode);
 130
 131         if (S_ISDIR(inode->i_mode))
 132                 return -EPERM;
 133
 134         if (inode->i_nlink >= NTFS_LINK_MAX)
 135                 return -EMLINK;
 136
 137         ni_lock_dir(ntfs_i(dir));
 138         if (inode != dir)
 139                 ni_lock(ni);
 140
 141         inc_nlink(inode);
 142         ihold(inode);
 143
 144         err = ntfs_link_inode(inode, de);
 145
 146         if (!err) {
 147                 dir->i_ctime = dir->i_mtime = inode->i_ctime =
 148                         current_time(dir);
 149                 mark_inode_dirty(inode);
 150                 mark_inode_dirty(dir);
 151                 d_instantiate(de, inode);
 152         } else {
 153                 drop_nlink(inode);
 154                 iput(inode);
 155         }
 156
 157         if (inode != dir)
 158                 ni_unlock(ni);
 159         ni_unlock(ntfs_i(dir));
 160
 161         return err;
 162 }
 163
 164 /*
 165  * ntfs_unlink - inode_operations::unlink
 166  */
 167 static int ntfs_unlink(struct inode *dir, struct dentry *dentry)
 168 {
 169         struct ntfs_inode *ni = ntfs_i(dir);
 170         int err;
 171
 172         ni_lock_dir(ni);
 173
 174         err = ntfs_unlink_inode(dir, dentry);
 175
 176         ni_unlock(ni);
 177
 178         return err;
 179 }
 180
 181 /*
 182  * ntfs_symlink - inode_operations::symlink
 183  */
 184 static int ntfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 185                         struct dentry *dentry, const char *symname)
 186 {
 187         u32 size = strlen(symname);
 188         struct inode *inode;
 189
 190         inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFLNK | 0777,
 191                                   0, symname, size, NULL);
 192
 193         return IS_ERR(inode) ? PTR_ERR(inode) : 0;
 194 }
 195
 196 /*
 197  * ntfs_mkdir- inode_operations::mkdir
 198  */
 199 static int ntfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 200                       struct dentry *dentry, umode_t mode)
 201 {
 202         struct inode *inode;
 203
 204         inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFDIR | mode,
 205                                   0, NULL, 0, NULL);
 206
 207         return IS_ERR(inode) ? PTR_ERR(inode) : 0;
 208 }
 209
 210 /*
 211  * ntfs_rmdir - inode_operations::rmdir
 212  */
 213 static int ntfs_rmdir(struct inode *dir, struct dentry *dentry)
 214 {
 215         struct ntfs_inode *ni = ntfs_i(dir);
 216         int err;
 217
 218         ni_lock_dir(ni);
 219
 220         err = ntfs_unlink_inode(dir, dentry);
 221
 222         ni_unlock(ni);
 223
 224         return err;
 225 }
 226
 227 /*
 228  * ntfs_rename - inode_operations::rename
 229  */
 230 static int ntfs_rename(struct user_namespace *mnt_userns, struct inode *dir,
 231                        struct dentry *dentry, struct inode *new_dir,
 232                        struct dentry *new_dentry, u32 flags)
 233 {
 234         int err;
 235         struct super_block *sb = dir->i_sb;
 236         struct ntfs_sb_info *sbi = sb->s_fs_info;
 237         struct ntfs_inode *dir_ni = ntfs_i(dir);
 238         struct ntfs_inode *new_dir_ni = ntfs_i(new_dir);
 239         struct inode *inode = d_inode(dentry);
 240         struct ntfs_inode *ni = ntfs_i(inode);
 241         struct inode *new_inode = d_inode(new_dentry);
 242         struct NTFS_DE *de, *new_de;
 243         bool is_same, is_bad;
 244         /*
 245          * de           - memory of PATH_MAX bytes:
 246          * [0-1024)     - original name (dentry->d_name)
 247          * [1024-2048)  - paired to original name, usually DOS variant of dentry->d_name
 248          * [2048-3072)  - new name (new_dentry->d_name)
 249          */
 250         static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + SIZEOF_RESIDENT < 1024);
 251         static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + sizeof(struct NTFS_DE) <
 252                       1024);
 253         static_assert(PATH_MAX >= 4 * 1024);
 254
 255         if (flags & ~RENAME_NOREPLACE)
 256                 return -EINVAL;
 257
 258         is_same = dentry->d_name.len == new_dentry->d_name.len &&
 259                   !memcmp(dentry->d_name.name, new_dentry->d_name.name,
 260                           dentry->d_name.len);
 261
 262         if (is_same && dir == new_dir) {
 263                 /* Nothing to do. */
 264                 return 0;
 265         }
 266
 267         if (ntfs_is_meta_file(sbi, inode->i_ino)) {
 268                 /* Should we print an error? */
 269                 return -EINVAL;
 270         }
 271
 272         if (new_inode) {
 273                 /* Target name exists. Unlink it. */
 274                 dget(new_dentry);
 275                 ni_lock_dir(new_dir_ni);
 276                 err = ntfs_unlink_inode(new_dir, new_dentry);
 277                 ni_unlock(new_dir_ni);
 278                 dput(new_dentry);
 279                 if (err)
 280                         return err;
 281         }
 282
 283         /* Allocate PATH_MAX bytes. */
 284         de = __getname();
 285         if (!de)
 286                 return -ENOMEM;
 287
 288         /* Translate dentry->d_name into unicode form. */
 289         err = fill_name_de(sbi, de, &dentry->d_name, NULL);
 290         if (err < 0)
 291                 goto out;
 292
 293         if (is_same) {
 294                 /* Reuse 'de'. */
 295                 new_de = de;
 296         } else {
 297                 /* Translate new_dentry->d_name into unicode form. */
 298                 new_de = Add2Ptr(de, 2048);
 299                 err = fill_name_de(sbi, new_de, &new_dentry->d_name, NULL);
 300                 if (err < 0)
 301                         goto out;
 302         }
 303
 304         ni_lock_dir(dir_ni);
 305         ni_lock(ni);
 306
 307         is_bad = false;
 308         err = ni_rename(dir_ni, new_dir_ni, ni, de, new_de, &is_bad);
 309         if (is_bad) {
 310                 /* Restore after failed rename failed too. */
 311                 _ntfs_bad_inode(inode);
 312         } else if (!err) {
 313                 inode->i_ctime = dir->i_ctime = dir->i_mtime =
 314                         current_time(dir);
 315                 mark_inode_dirty(inode);
 316                 mark_inode_dirty(dir);
 317                 if (dir != new_dir) {
 318                         new_dir->i_mtime = new_dir->i_ctime = dir->i_ctime;
 319                         mark_inode_dirty(new_dir);
 320                 }
 321
 322                 if (IS_DIRSYNC(dir))
 323                         ntfs_sync_inode(dir);
 324
 325                 if (IS_DIRSYNC(new_dir))
 326                         ntfs_sync_inode(inode);
 327         }
 328
 329         ni_unlock(ni);
 330         ni_unlock(dir_ni);
 331 out:
 332         __putname(de);
 333         return err;
 334 }
 335
 336 struct dentry *ntfs3_get_parent(struct dentry *child)
 337 {
 338         struct inode *inode = d_inode(child);
 339         struct ntfs_inode *ni = ntfs_i(inode);
 340
 341         struct ATTR_LIST_ENTRY *le = NULL;
 342         struct ATTRIB *attr = NULL;
 343         struct ATTR_FILE_NAME *fname;
 344
 345         while ((attr = ni_find_attr(ni, attr, &le, ATTR_NAME, NULL, 0, NULL,
 346                                     NULL))) {
 347                 fname = resident_data_ex(attr, SIZEOF_ATTRIBUTE_FILENAME);
 348                 if (!fname)
 349                         continue;
 350
 351                 return d_obtain_alias(
 352                         ntfs_iget5(inode->i_sb, &fname->home, NULL));
 353         }
 354
 355         return ERR_PTR(-ENOENT);
 356 }
 357
 358 // clang-format off
 359 const struct inode_operations ntfs_dir_inode_operations = {
 360         .lookup         = ntfs_lookup,
 361         .create         = ntfs_create,
 362         .link           = ntfs_link,
 363         .unlink         = ntfs_unlink,
 364         .symlink        = ntfs_symlink,
 365         .mkdir          = ntfs_mkdir,
 366         .rmdir          = ntfs_rmdir,
 367         .mknod          = ntfs_mknod,
 368         .rename         = ntfs_rename,
 369         .permission     = ntfs_permission,
 370         .get_inode_acl  = ntfs_get_acl,
 371         .set_acl        = ntfs_set_acl,
 372         .setattr        = ntfs3_setattr,
 373         .getattr        = ntfs_getattr,
 374         .listxattr      = ntfs_listxattr,
 375         .fiemap         = ntfs_fiemap,
 376 };
 377
 378 const struct inode_operations ntfs_special_inode_operations = {
 379         .setattr        = ntfs3_setattr,
 380         .getattr        = ntfs_getattr,
 381         .listxattr      = ntfs_listxattr,
 382         .get_inode_acl  = ntfs_get_acl,
 383         .set_acl        = ntfs_set_acl,
 384 };
 385 // clang-format on