1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/sysv/inode.c
4 *
5 * minix/inode.c
6 * Copyright (C) 1991, 1992 Linus Torvalds
7 *
8 * xenix/inode.c
9 * Copyright (C) 1992 Doug Evans
10 *
11 * coh/inode.c
12 * Copyright (C) 1993 Pascal Haible, Bruno Haible
13 *
14 * sysv/inode.c
15 * Copyright (C) 1993 Paul B. Monday
16 *
17 * sysv/inode.c
18 * Copyright (C) 1993 Bruno Haible
19 * Copyright (C) 1997, 1998 Krzysztof G. Baranowski
20 *
21 * This file contains code for allocating/freeing inodes and for read/writing
22 * the superblock.
23 */
24
25 #include <linux/highuid.h>
26 #include <linux/slab.h>
27 #include <linux/init.h>
28 #include <linux/buffer_head.h>
29 #include <linux/vfs.h>
30 #include <linux/writeback.h>
31 #include <linux/namei.h>
32 #include <asm/byteorder.h>
33 #include "sysv.h"
34
sysv_sync_fs(struct super_block * sb,int wait)35 static int sysv_sync_fs(struct super_block *sb, int wait)
36 {
37 struct sysv_sb_info *sbi = SYSV_SB(sb);
38 u32 time = (u32)ktime_get_real_seconds(), old_time;
39
40 mutex_lock(&sbi->s_lock);
41
42 /*
43 * If we are going to write out the super block,
44 * then attach current time stamp.
45 * But if the filesystem was marked clean, keep it clean.
46 */
47 old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
48 if (sbi->s_type == FSTYPE_SYSV4) {
49 if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38u - old_time))
50 *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38u - time);
51 *sbi->s_sb_time = cpu_to_fs32(sbi, time);
52 mark_buffer_dirty(sbi->s_bh2);
53 }
54
55 mutex_unlock(&sbi->s_lock);
56
57 return 0;
58 }
59
sysv_remount(struct super_block * sb,int * flags,char * data)60 static int sysv_remount(struct super_block *sb, int *flags, char *data)
61 {
62 struct sysv_sb_info *sbi = SYSV_SB(sb);
63
64 sync_filesystem(sb);
65 if (sbi->s_forced_ro)
66 *flags |= SB_RDONLY;
67 return 0;
68 }
69
sysv_put_super(struct super_block * sb)70 static void sysv_put_super(struct super_block *sb)
71 {
72 struct sysv_sb_info *sbi = SYSV_SB(sb);
73
74 if (!sb_rdonly(sb)) {
75 /* XXX ext2 also updates the state here */
76 mark_buffer_dirty(sbi->s_bh1);
77 if (sbi->s_bh1 != sbi->s_bh2)
78 mark_buffer_dirty(sbi->s_bh2);
79 }
80
81 brelse(sbi->s_bh1);
82 if (sbi->s_bh1 != sbi->s_bh2)
83 brelse(sbi->s_bh2);
84
85 kfree(sbi);
86 }
87
sysv_statfs(struct dentry * dentry,struct kstatfs * buf)88 static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
89 {
90 struct super_block *sb = dentry->d_sb;
91 struct sysv_sb_info *sbi = SYSV_SB(sb);
92 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
93
94 buf->f_type = sb->s_magic;
95 buf->f_bsize = sb->s_blocksize;
96 buf->f_blocks = sbi->s_ndatazones;
97 buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
98 buf->f_files = sbi->s_ninodes;
99 buf->f_ffree = sysv_count_free_inodes(sb);
100 buf->f_namelen = SYSV_NAMELEN;
101 buf->f_fsid = u64_to_fsid(id);
102 return 0;
103 }
104
105 /*
106 * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
107 */
read3byte(struct sysv_sb_info * sbi,unsigned char * from,unsigned char * to)108 static inline void read3byte(struct sysv_sb_info *sbi,
109 unsigned char * from, unsigned char * to)
110 {
111 if (sbi->s_bytesex == BYTESEX_PDP) {
112 to[0] = from[0];
113 to[1] = 0;
114 to[2] = from[1];
115 to[3] = from[2];
116 } else if (sbi->s_bytesex == BYTESEX_LE) {
117 to[0] = from[0];
118 to[1] = from[1];
119 to[2] = from[2];
120 to[3] = 0;
121 } else {
122 to[0] = 0;
123 to[1] = from[0];
124 to[2] = from[1];
125 to[3] = from[2];
126 }
127 }
128
write3byte(struct sysv_sb_info * sbi,unsigned char * from,unsigned char * to)129 static inline void write3byte(struct sysv_sb_info *sbi,
130 unsigned char * from, unsigned char * to)
131 {
132 if (sbi->s_bytesex == BYTESEX_PDP) {
133 to[0] = from[0];
134 to[1] = from[2];
135 to[2] = from[3];
136 } else if (sbi->s_bytesex == BYTESEX_LE) {
137 to[0] = from[0];
138 to[1] = from[1];
139 to[2] = from[2];
140 } else {
141 to[0] = from[1];
142 to[1] = from[2];
143 to[2] = from[3];
144 }
145 }
146
147 static const struct inode_operations sysv_symlink_inode_operations = {
148 .get_link = page_get_link,
149 .getattr = sysv_getattr,
150 };
151
sysv_set_inode(struct inode * inode,dev_t rdev)152 void sysv_set_inode(struct inode *inode, dev_t rdev)
153 {
154 if (S_ISREG(inode->i_mode)) {
155 inode->i_op = &sysv_file_inode_operations;
156 inode->i_fop = &sysv_file_operations;
157 inode->i_mapping->a_ops = &sysv_aops;
158 } else if (S_ISDIR(inode->i_mode)) {
159 inode->i_op = &sysv_dir_inode_operations;
160 inode->i_fop = &sysv_dir_operations;
161 inode->i_mapping->a_ops = &sysv_aops;
162 } else if (S_ISLNK(inode->i_mode)) {
163 inode->i_op = &sysv_symlink_inode_operations;
164 inode_nohighmem(inode);
165 inode->i_mapping->a_ops = &sysv_aops;
166 } else
167 init_special_inode(inode, inode->i_mode, rdev);
168 }
169
sysv_iget(struct super_block * sb,unsigned int ino)170 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
171 {
172 struct sysv_sb_info * sbi = SYSV_SB(sb);
173 struct buffer_head * bh;
174 struct sysv_inode * raw_inode;
175 struct sysv_inode_info * si;
176 struct inode *inode;
177 unsigned int block;
178
179 if (!ino || ino > sbi->s_ninodes) {
180 printk("Bad inode number on dev %s: %d is out of range\n",
181 sb->s_id, ino);
182 return ERR_PTR(-EIO);
183 }
184
185 inode = iget_locked(sb, ino);
186 if (!inode)
187 return ERR_PTR(-ENOMEM);
188 if (!(inode->i_state & I_NEW))
189 return inode;
190
191 raw_inode = sysv_raw_inode(sb, ino, &bh);
192 if (!raw_inode) {
193 printk("Major problem: unable to read inode from dev %s\n",
194 inode->i_sb->s_id);
195 goto bad_inode;
196 }
197 /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
198 inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
199 i_uid_write(inode, (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid));
200 i_gid_write(inode, (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid));
201 set_nlink(inode, fs16_to_cpu(sbi, raw_inode->i_nlink));
202 inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
203 inode_set_atime(inode, fs32_to_cpu(sbi, raw_inode->i_atime), 0);
204 inode_set_mtime(inode, fs32_to_cpu(sbi, raw_inode->i_mtime), 0);
205 inode_set_ctime(inode, fs32_to_cpu(sbi, raw_inode->i_ctime), 0);
206 inode->i_blocks = 0;
207
208 si = SYSV_I(inode);
209 for (block = 0; block < 10+1+1+1; block++)
210 read3byte(sbi, &raw_inode->i_data[3*block],
211 (u8 *)&si->i_data[block]);
212 brelse(bh);
213 si->i_dir_start_lookup = 0;
214 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
215 sysv_set_inode(inode,
216 old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
217 else
218 sysv_set_inode(inode, 0);
219 unlock_new_inode(inode);
220 return inode;
221
222 bad_inode:
223 iget_failed(inode);
224 return ERR_PTR(-EIO);
225 }
226
__sysv_write_inode(struct inode * inode,int wait)227 static int __sysv_write_inode(struct inode *inode, int wait)
228 {
229 struct super_block * sb = inode->i_sb;
230 struct sysv_sb_info * sbi = SYSV_SB(sb);
231 struct buffer_head * bh;
232 struct sysv_inode * raw_inode;
233 struct sysv_inode_info * si;
234 unsigned int ino, block;
235 int err = 0;
236
237 ino = inode->i_ino;
238 if (!ino || ino > sbi->s_ninodes) {
239 printk("Bad inode number on dev %s: %d is out of range\n",
240 inode->i_sb->s_id, ino);
241 return -EIO;
242 }
243 raw_inode = sysv_raw_inode(sb, ino, &bh);
244 if (!raw_inode) {
245 printk("unable to read i-node block\n");
246 return -EIO;
247 }
248
249 raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
250 raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(i_uid_read(inode)));
251 raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(i_gid_read(inode)));
252 raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
253 raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
254 raw_inode->i_atime = cpu_to_fs32(sbi, inode_get_atime_sec(inode));
255 raw_inode->i_mtime = cpu_to_fs32(sbi, inode_get_mtime_sec(inode));
256 raw_inode->i_ctime = cpu_to_fs32(sbi, inode_get_ctime_sec(inode));
257
258 si = SYSV_I(inode);
259 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
260 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
261 for (block = 0; block < 10+1+1+1; block++)
262 write3byte(sbi, (u8 *)&si->i_data[block],
263 &raw_inode->i_data[3*block]);
264 mark_buffer_dirty(bh);
265 if (wait) {
266 sync_dirty_buffer(bh);
267 if (buffer_req(bh) && !buffer_uptodate(bh)) {
268 printk ("IO error syncing sysv inode [%s:%08x]\n",
269 sb->s_id, ino);
270 err = -EIO;
271 }
272 }
273 brelse(bh);
274 return err;
275 }
276
sysv_write_inode(struct inode * inode,struct writeback_control * wbc)277 int sysv_write_inode(struct inode *inode, struct writeback_control *wbc)
278 {
279 return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
280 }
281
sysv_sync_inode(struct inode * inode)282 int sysv_sync_inode(struct inode *inode)
283 {
284 return __sysv_write_inode(inode, 1);
285 }
286
sysv_evict_inode(struct inode * inode)287 static void sysv_evict_inode(struct inode *inode)
288 {
289 truncate_inode_pages_final(&inode->i_data);
290 if (!inode->i_nlink) {
291 inode->i_size = 0;
292 sysv_truncate(inode);
293 }
294 invalidate_inode_buffers(inode);
295 clear_inode(inode);
296 if (!inode->i_nlink)
297 sysv_free_inode(inode);
298 }
299
300 static struct kmem_cache *sysv_inode_cachep;
301
sysv_alloc_inode(struct super_block * sb)302 static struct inode *sysv_alloc_inode(struct super_block *sb)
303 {
304 struct sysv_inode_info *si;
305
306 si = alloc_inode_sb(sb, sysv_inode_cachep, GFP_KERNEL);
307 if (!si)
308 return NULL;
309 return &si->vfs_inode;
310 }
311
sysv_free_in_core_inode(struct inode * inode)312 static void sysv_free_in_core_inode(struct inode *inode)
313 {
314 kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
315 }
316
init_once(void * p)317 static void init_once(void *p)
318 {
319 struct sysv_inode_info *si = (struct sysv_inode_info *)p;
320
321 inode_init_once(&si->vfs_inode);
322 }
323
324 const struct super_operations sysv_sops = {
325 .alloc_inode = sysv_alloc_inode,
326 .free_inode = sysv_free_in_core_inode,
327 .write_inode = sysv_write_inode,
328 .evict_inode = sysv_evict_inode,
329 .put_super = sysv_put_super,
330 .sync_fs = sysv_sync_fs,
331 .remount_fs = sysv_remount,
332 .statfs = sysv_statfs,
333 };
334
sysv_init_icache(void)335 int __init sysv_init_icache(void)
336 {
337 sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
338 sizeof(struct sysv_inode_info), 0,
339 SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT,
340 init_once);
341 if (!sysv_inode_cachep)
342 return -ENOMEM;
343 return 0;
344 }
345
sysv_destroy_icache(void)346 void sysv_destroy_icache(void)
347 {
348 /*
349 * Make sure all delayed rcu free inodes are flushed before we
350 * destroy cache.
351 */
352 rcu_barrier();
353 kmem_cache_destroy(sysv_inode_cachep);
354 }
355