fs/ntfs3/namei.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  *
0004  * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
0005  *
0006  */
0007
0008 #include <linux/fs.h>
0009 #include <linux/nls.h>
0010
0011 #include "debug.h"
0012 #include "ntfs.h"
0013 #include "ntfs_fs.h"
0014
0015 /*
0016  * fill_name_de - Format NTFS_DE in @buf.
0017  */
0018 int fill_name_de(struct ntfs_sb_info *sbi, void *buf, const struct qstr *name,
0019          const struct cpu_str *uni)
0020 {
0021     int err;
0022     struct NTFS_DE *e = buf;
0023     u16 data_size;
0024     struct ATTR_FILE_NAME *fname = (struct ATTR_FILE_NAME *)(e + 1);
0025
0026 #ifndef CONFIG_NTFS3_64BIT_CLUSTER
0027     e->ref.high = fname->home.high = 0;
0028 #endif
0029     if (uni) {
0030 #ifdef __BIG_ENDIAN
0031         int ulen = uni->len;
0032         __le16 *uname = fname->name;
0033         const u16 *name_cpu = uni->name;
0034
0035         while (ulen--)
0036             *uname++ = cpu_to_le16(*name_cpu++);
0037 #else
0038         memcpy(fname->name, uni->name, uni->len * sizeof(u16));
0039 #endif
0040         fname->name_len = uni->len;
0041
0042     } else {
0043         /* Convert input string to unicode. */
0044         err = ntfs_nls_to_utf16(sbi, name->name, name->len,
0045                     (struct cpu_str *)&fname->name_len,
0046                     NTFS_NAME_LEN, UTF16_LITTLE_ENDIAN);
0047         if (err < 0)
0048             return err;
0049     }
0050
0051     fname->type = FILE_NAME_POSIX;
0052     data_size = fname_full_size(fname);
0053
0054     e->size = cpu_to_le16(ALIGN(data_size, 8) + sizeof(struct NTFS_DE));
0055     e->key_size = cpu_to_le16(data_size);
0056     e->flags = 0;
0057     e->res = 0;
0058
0059     return 0;
0060 }
0061
0062 /*
0063  * ntfs_lookup - inode_operations::lookup
0064  */
0065 static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
0066                   u32 flags)
0067 {
0068     struct ntfs_inode *ni = ntfs_i(dir);
0069     struct cpu_str *uni = __getname();
0070     struct inode *inode;
0071     int err;
0072
0073     if (!uni)
0074         inode = ERR_PTR(-ENOMEM);
0075     else {
0076         err = ntfs_nls_to_utf16(ni->mi.sbi, dentry->d_name.name,
0077                     dentry->d_name.len, uni, NTFS_NAME_LEN,
0078                     UTF16_HOST_ENDIAN);
0079         if (err < 0)
0080             inode = ERR_PTR(err);
0081         else {
0082             ni_lock(ni);
0083             inode = dir_search_u(dir, uni, NULL);
0084             ni_unlock(ni);
0085         }
0086         __putname(uni);
0087     }
0088
0089     return d_splice_alias(inode, dentry);
0090 }
0091
0092 /*
0093  * ntfs_create - inode_operations::create
0094  */
0095 static int ntfs_create(struct user_namespace *mnt_userns, struct inode *dir,
0096                struct dentry *dentry, umode_t mode, bool excl)
0097 {
0098     struct inode *inode;
0099
0100     inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFREG | mode,
0101                   0, NULL, 0, NULL);
0102
0103     return IS_ERR(inode) ? PTR_ERR(inode) : 0;
0104 }
0105
0106 /*
0107  * ntfs_mknod
0108  *
0109  * inode_operations::mknod
0110  */
0111 static int ntfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
0112               struct dentry *dentry, umode_t mode, dev_t rdev)
0113 {
0114     struct inode *inode;
0115
0116     inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, mode, rdev,
0117                   NULL, 0, NULL);
0118
0119     return IS_ERR(inode) ? PTR_ERR(inode) : 0;
0120 }
0121
0122 /*
0123  * ntfs_link - inode_operations::link
0124  */
0125 static int ntfs_link(struct dentry *ode, struct inode *dir, struct dentry *de)
0126 {
0127     int err;
0128     struct inode *inode = d_inode(ode);
0129     struct ntfs_inode *ni = ntfs_i(inode);
0130
0131     if (S_ISDIR(inode->i_mode))
0132         return -EPERM;
0133
0134     if (inode->i_nlink >= NTFS_LINK_MAX)
0135         return -EMLINK;
0136
0137     ni_lock_dir(ntfs_i(dir));
0138     if (inode != dir)
0139         ni_lock(ni);
0140
0141     inc_nlink(inode);
0142     ihold(inode);
0143
0144     err = ntfs_link_inode(inode, de);
0145
0146     if (!err) {
0147         dir->i_ctime = dir->i_mtime = inode->i_ctime =
0148             current_time(dir);
0149         mark_inode_dirty(inode);
0150         mark_inode_dirty(dir);
0151         d_instantiate(de, inode);
0152     } else {
0153         drop_nlink(inode);
0154         iput(inode);
0155     }
0156
0157     if (inode != dir)
0158         ni_unlock(ni);
0159     ni_unlock(ntfs_i(dir));
0160
0161     return err;
0162 }
0163
0164 /*
0165  * ntfs_unlink - inode_operations::unlink
0166  */
0167 static int ntfs_unlink(struct inode *dir, struct dentry *dentry)
0168 {
0169     struct ntfs_inode *ni = ntfs_i(dir);
0170     int err;
0171
0172     ni_lock_dir(ni);
0173
0174     err = ntfs_unlink_inode(dir, dentry);
0175
0176     ni_unlock(ni);
0177
0178     return err;
0179 }
0180
0181 /*
0182  * ntfs_symlink - inode_operations::symlink
0183  */
0184 static int ntfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
0185             struct dentry *dentry, const char *symname)
0186 {
0187     u32 size = strlen(symname);
0188     struct inode *inode;
0189
0190     inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFLNK | 0777,
0191                   0, symname, size, NULL);
0192
0193     return IS_ERR(inode) ? PTR_ERR(inode) : 0;
0194 }
0195
0196 /*
0197  * ntfs_mkdir- inode_operations::mkdir
0198  */
0199 static int ntfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
0200               struct dentry *dentry, umode_t mode)
0201 {
0202     struct inode *inode;
0203
0204     inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFDIR | mode,
0205                   0, NULL, 0, NULL);
0206
0207     return IS_ERR(inode) ? PTR_ERR(inode) : 0;
0208 }
0209
0210 /*
0211  * ntfs_rmdir - inode_operations::rmdir
0212  */
0213 static int ntfs_rmdir(struct inode *dir, struct dentry *dentry)
0214 {
0215     struct ntfs_inode *ni = ntfs_i(dir);
0216     int err;
0217
0218     ni_lock_dir(ni);
0219
0220     err = ntfs_unlink_inode(dir, dentry);
0221
0222     ni_unlock(ni);
0223
0224     return err;
0225 }
0226
0227 /*
0228  * ntfs_rename - inode_operations::rename
0229  */
0230 static int ntfs_rename(struct user_namespace *mnt_userns, struct inode *dir,
0231                struct dentry *dentry, struct inode *new_dir,
0232                struct dentry *new_dentry, u32 flags)
0233 {
0234     int err;
0235     struct super_block *sb = dir->i_sb;
0236     struct ntfs_sb_info *sbi = sb->s_fs_info;
0237     struct ntfs_inode *dir_ni = ntfs_i(dir);
0238     struct ntfs_inode *new_dir_ni = ntfs_i(new_dir);
0239     struct inode *inode = d_inode(dentry);
0240     struct ntfs_inode *ni = ntfs_i(inode);
0241     struct inode *new_inode = d_inode(new_dentry);
0242     struct NTFS_DE *de, *new_de;
0243     bool is_same, is_bad;
0244     /*
0245      * de       - memory of PATH_MAX bytes:
0246      * [0-1024) - original name (dentry->d_name)
0247      * [1024-2048)  - paired to original name, usually DOS variant of dentry->d_name
0248      * [2048-3072)  - new name (new_dentry->d_name)
0249      */
0250     static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + SIZEOF_RESIDENT < 1024);
0251     static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + sizeof(struct NTFS_DE) <
0252               1024);
0253     static_assert(PATH_MAX >= 4 * 1024);
0254
0255     if (flags & ~RENAME_NOREPLACE)
0256         return -EINVAL;
0257
0258     is_same = dentry->d_name.len == new_dentry->d_name.len &&
0259           !memcmp(dentry->d_name.name, new_dentry->d_name.name,
0260               dentry->d_name.len);
0261
0262     if (is_same && dir == new_dir) {
0263         /* Nothing to do. */
0264         return 0;
0265     }
0266
0267     if (ntfs_is_meta_file(sbi, inode->i_ino)) {
0268         /* Should we print an error? */
0269         return -EINVAL;
0270     }
0271
0272     if (new_inode) {
0273         /* Target name exists. Unlink it. */
0274         dget(new_dentry);
0275         ni_lock_dir(new_dir_ni);
0276         err = ntfs_unlink_inode(new_dir, new_dentry);
0277         ni_unlock(new_dir_ni);
0278         dput(new_dentry);
0279         if (err)
0280             return err;
0281     }
0282
0283     /* Allocate PATH_MAX bytes. */
0284     de = __getname();
0285     if (!de)
0286         return -ENOMEM;
0287
0288     /* Translate dentry->d_name into unicode form. */
0289     err = fill_name_de(sbi, de, &dentry->d_name, NULL);
0290     if (err < 0)
0291         goto out;
0292
0293     if (is_same) {
0294         /* Reuse 'de'. */
0295         new_de = de;
0296     } else {
0297         /* Translate new_dentry->d_name into unicode form. */
0298         new_de = Add2Ptr(de, 2048);
0299         err = fill_name_de(sbi, new_de, &new_dentry->d_name, NULL);
0300         if (err < 0)
0301             goto out;
0302     }
0303
0304     ni_lock_dir(dir_ni);
0305     ni_lock(ni);
0306
0307     is_bad = false;
0308     err = ni_rename(dir_ni, new_dir_ni, ni, de, new_de, &is_bad);
0309     if (is_bad) {
0310         /* Restore after failed rename failed too. */
0311         _ntfs_bad_inode(inode);
0312     } else if (!err) {
0313         inode->i_ctime = dir->i_ctime = dir->i_mtime =
0314             current_time(dir);
0315         mark_inode_dirty(inode);
0316         mark_inode_dirty(dir);
0317         if (dir != new_dir) {
0318             new_dir->i_mtime = new_dir->i_ctime = dir->i_ctime;
0319             mark_inode_dirty(new_dir);
0320         }
0321
0322         if (IS_DIRSYNC(dir))
0323             ntfs_sync_inode(dir);
0324
0325         if (IS_DIRSYNC(new_dir))
0326             ntfs_sync_inode(inode);
0327     }
0328
0329     ni_unlock(ni);
0330     ni_unlock(dir_ni);
0331 out:
0332     __putname(de);
0333     return err;
0334 }
0335
0336 struct dentry *ntfs3_get_parent(struct dentry *child)
0337 {
0338     struct inode *inode = d_inode(child);
0339     struct ntfs_inode *ni = ntfs_i(inode);
0340
0341     struct ATTR_LIST_ENTRY *le = NULL;
0342     struct ATTRIB *attr = NULL;
0343     struct ATTR_FILE_NAME *fname;
0344
0345     while ((attr = ni_find_attr(ni, attr, &le, ATTR_NAME, NULL, 0, NULL,
0346                     NULL))) {
0347         fname = resident_data_ex(attr, SIZEOF_ATTRIBUTE_FILENAME);
0348         if (!fname)
0349             continue;
0350
0351         return d_obtain_alias(
0352             ntfs_iget5(inode->i_sb, &fname->home, NULL));
0353     }
0354
0355     return ERR_PTR(-ENOENT);
0356 }
0357
0358 // clang-format off
0359 const struct inode_operations ntfs_dir_inode_operations = {
0360     .lookup     = ntfs_lookup,
0361     .create     = ntfs_create,
0362     .link       = ntfs_link,
0363     .unlink     = ntfs_unlink,
0364     .symlink    = ntfs_symlink,
0365     .mkdir      = ntfs_mkdir,
0366     .rmdir      = ntfs_rmdir,
0367     .mknod      = ntfs_mknod,
0368     .rename     = ntfs_rename,
0369     .permission = ntfs_permission,
0370     .get_acl    = ntfs_get_acl,
0371     .set_acl    = ntfs_set_acl,
0372     .setattr    = ntfs3_setattr,
0373     .getattr    = ntfs_getattr,
0374     .listxattr  = ntfs_listxattr,
0375     .fiemap     = ntfs_fiemap,
0376 };
0377
0378 const struct inode_operations ntfs_special_inode_operations = {
0379     .setattr    = ntfs3_setattr,
0380     .getattr    = ntfs_getattr,
0381     .listxattr  = ntfs_listxattr,
0382     .get_acl    = ntfs_get_acl,
0383     .set_acl    = ntfs_set_acl,
0384 };
0385 // clang-format on