1 // SPDX-License-Identifier: GPL-2.0
3 * linux/fs/sysv/namei.c
6 * Copyright (C) 1991, 1992 Linus Torvalds
9 * Copyright (C) 1993 Pascal Haible, Bruno Haible
12 * Copyright (C) 1993 Bruno Haible
13 * Copyright (C) 1997, 1998 Krzysztof G. Baranowski
16 #include <linux/pagemap.h>
19 static int add_nondir(struct dentry
*dentry
, struct inode
*inode
)
21 int err
= sysv_add_link(dentry
, inode
);
23 d_instantiate(dentry
, inode
);
26 inode_dec_link_count(inode
);
31 static struct dentry
*sysv_lookup(struct inode
* dir
, struct dentry
* dentry
, unsigned int flags
)
33 struct inode
* inode
= NULL
;
36 if (dentry
->d_name
.len
> SYSV_NAMELEN
)
37 return ERR_PTR(-ENAMETOOLONG
);
38 ino
= sysv_inode_by_name(dentry
);
40 inode
= sysv_iget(dir
->i_sb
, ino
);
41 return d_splice_alias(inode
, dentry
);
44 static int sysv_mknod(struct user_namespace
*mnt_userns
, struct inode
*dir
,
45 struct dentry
*dentry
, umode_t mode
, dev_t rdev
)
50 if (!old_valid_dev(rdev
))
53 inode
= sysv_new_inode(dir
, mode
);
57 sysv_set_inode(inode
, rdev
);
58 mark_inode_dirty(inode
);
59 err
= add_nondir(dentry
, inode
);
64 static int sysv_create(struct user_namespace
*mnt_userns
, struct inode
*dir
,
65 struct dentry
*dentry
, umode_t mode
, bool excl
)
67 return sysv_mknod(&init_user_ns
, dir
, dentry
, mode
, 0);
70 static int sysv_symlink(struct user_namespace
*mnt_userns
, struct inode
*dir
,
71 struct dentry
*dentry
, const char *symname
)
73 int err
= -ENAMETOOLONG
;
74 int l
= strlen(symname
)+1;
77 if (l
> dir
->i_sb
->s_blocksize
)
80 inode
= sysv_new_inode(dir
, S_IFLNK
|0777);
85 sysv_set_inode(inode
, 0);
86 err
= page_symlink(inode
, symname
, l
);
90 mark_inode_dirty(inode
);
91 err
= add_nondir(dentry
, inode
);
96 inode_dec_link_count(inode
);
101 static int sysv_link(struct dentry
* old_dentry
, struct inode
* dir
,
102 struct dentry
* dentry
)
104 struct inode
*inode
= d_inode(old_dentry
);
106 inode
->i_ctime
= current_time(inode
);
107 inode_inc_link_count(inode
);
110 return add_nondir(dentry
, inode
);
113 static int sysv_mkdir(struct user_namespace
*mnt_userns
, struct inode
*dir
,
114 struct dentry
*dentry
, umode_t mode
)
116 struct inode
* inode
;
119 inode_inc_link_count(dir
);
121 inode
= sysv_new_inode(dir
, S_IFDIR
|mode
);
122 err
= PTR_ERR(inode
);
126 sysv_set_inode(inode
, 0);
128 inode_inc_link_count(inode
);
130 err
= sysv_make_empty(inode
, dir
);
134 err
= sysv_add_link(dentry
, inode
);
138 d_instantiate(dentry
, inode
);
143 inode_dec_link_count(inode
);
144 inode_dec_link_count(inode
);
147 inode_dec_link_count(dir
);
151 static int sysv_unlink(struct inode
* dir
, struct dentry
* dentry
)
153 struct inode
* inode
= d_inode(dentry
);
155 struct sysv_dir_entry
* de
;
158 de
= sysv_find_entry(dentry
, &page
);
162 err
= sysv_delete_entry (de
, page
);
166 inode
->i_ctime
= dir
->i_ctime
;
167 inode_dec_link_count(inode
);
172 static int sysv_rmdir(struct inode
* dir
, struct dentry
* dentry
)
174 struct inode
*inode
= d_inode(dentry
);
175 int err
= -ENOTEMPTY
;
177 if (sysv_empty_dir(inode
)) {
178 err
= sysv_unlink(dir
, dentry
);
181 inode_dec_link_count(inode
);
182 inode_dec_link_count(dir
);
189 * Anybody can rename anything with this: the permission checks are left to the
190 * higher-level routines.
192 static int sysv_rename(struct user_namespace
*mnt_userns
, struct inode
*old_dir
,
193 struct dentry
*old_dentry
, struct inode
*new_dir
,
194 struct dentry
*new_dentry
, unsigned int flags
)
196 struct inode
* old_inode
= d_inode(old_dentry
);
197 struct inode
* new_inode
= d_inode(new_dentry
);
198 struct page
* dir_page
= NULL
;
199 struct sysv_dir_entry
* dir_de
= NULL
;
200 struct page
* old_page
;
201 struct sysv_dir_entry
* old_de
;
204 if (flags
& ~RENAME_NOREPLACE
)
207 old_de
= sysv_find_entry(old_dentry
, &old_page
);
211 if (S_ISDIR(old_inode
->i_mode
)) {
213 dir_de
= sysv_dotdot(old_inode
, &dir_page
);
219 struct page
* new_page
;
220 struct sysv_dir_entry
* new_de
;
223 if (dir_de
&& !sysv_empty_dir(new_inode
))
227 new_de
= sysv_find_entry(new_dentry
, &new_page
);
230 sysv_set_link(new_de
, new_page
, old_inode
);
231 new_inode
->i_ctime
= current_time(new_inode
);
233 drop_nlink(new_inode
);
234 inode_dec_link_count(new_inode
);
236 err
= sysv_add_link(new_dentry
, old_inode
);
240 inode_inc_link_count(new_dir
);
243 sysv_delete_entry(old_de
, old_page
);
244 mark_inode_dirty(old_inode
);
247 sysv_set_link(dir_de
, dir_page
, new_dir
);
248 inode_dec_link_count(old_dir
);
265 * directories can handle most operations...
267 const struct inode_operations sysv_dir_inode_operations
= {
268 .create
= sysv_create
,
269 .lookup
= sysv_lookup
,
271 .unlink
= sysv_unlink
,
272 .symlink
= sysv_symlink
,
276 .rename
= sysv_rename
,
277 .getattr
= sysv_getattr
,