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.val[0] = (u32)id;
102 buf->f_fsid.val[1] = (u32)(id >> 32);
103 return 0;
104 }
105
106 /*
107 * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
108 */
read3byte(struct sysv_sb_info * sbi,unsigned char * from,unsigned char * to)109 static inline void read3byte(struct sysv_sb_info *sbi,
110 unsigned char * from, unsigned char * to)
111 {
112 if (sbi->s_bytesex == BYTESEX_PDP) {
113 to[0] = from[0];
114 to[1] = 0;
115 to[2] = from[1];
116 to[3] = from[2];
117 } else if (sbi->s_bytesex == BYTESEX_LE) {
118 to[0] = from[0];
119 to[1] = from[1];
120 to[2] = from[2];
121 to[3] = 0;
122 } else {
123 to[0] = 0;
124 to[1] = from[0];
125 to[2] = from[1];
126 to[3] = from[2];
127 }
128 }
129
write3byte(struct sysv_sb_info * sbi,unsigned char * from,unsigned char * to)130 static inline void write3byte(struct sysv_sb_info *sbi,
131 unsigned char * from, unsigned char * to)
132 {
133 if (sbi->s_bytesex == BYTESEX_PDP) {
134 to[0] = from[0];
135 to[1] = from[2];
136 to[2] = from[3];
137 } else if (sbi->s_bytesex == BYTESEX_LE) {
138 to[0] = from[0];
139 to[1] = from[1];
140 to[2] = from[2];
141 } else {
142 to[0] = from[1];
143 to[1] = from[2];
144 to[2] = from[3];
145 }
146 }
147
148 static const struct inode_operations sysv_symlink_inode_operations = {
149 .get_link = page_get_link,
150 .getattr = sysv_getattr,
151 };
152
sysv_set_inode(struct inode * inode,dev_t rdev)153 void sysv_set_inode(struct inode *inode, dev_t rdev)
154 {
155 if (S_ISREG(inode->i_mode)) {
156 inode->i_op = &sysv_file_inode_operations;
157 inode->i_fop = &sysv_file_operations;
158 inode->i_mapping->a_ops = &sysv_aops;
159 } else if (S_ISDIR(inode->i_mode)) {
160 inode->i_op = &sysv_dir_inode_operations;
161 inode->i_fop = &sysv_dir_operations;
162 inode->i_mapping->a_ops = &sysv_aops;
163 } else if (S_ISLNK(inode->i_mode)) {
164 inode->i_op = &sysv_symlink_inode_operations;
165 inode_nohighmem(inode);
166 inode->i_mapping->a_ops = &sysv_aops;
167 } else
168 init_special_inode(inode, inode->i_mode, rdev);
169 }
170
sysv_iget(struct super_block * sb,unsigned int ino)171 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
172 {
173 struct sysv_sb_info * sbi = SYSV_SB(sb);
174 struct buffer_head * bh;
175 struct sysv_inode * raw_inode;
176 struct sysv_inode_info * si;
177 struct inode *inode;
178 unsigned int block;
179
180 if (!ino || ino > sbi->s_ninodes) {
181 printk("Bad inode number on dev %s: %d is out of range\n",
182 sb->s_id, ino);
183 return ERR_PTR(-EIO);
184 }
185
186 inode = iget_locked(sb, ino);
187 if (!inode)
188 return ERR_PTR(-ENOMEM);
189 if (!(inode->i_state & I_NEW))
190 return inode;
191
192 raw_inode = sysv_raw_inode(sb, ino, &bh);
193 if (!raw_inode) {
194 printk("Major problem: unable to read inode from dev %s\n",
195 inode->i_sb->s_id);
196 goto bad_inode;
197 }
198 /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
199 inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
200 i_uid_write(inode, (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid));
201 i_gid_write(inode, (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid));
202 set_nlink(inode, fs16_to_cpu(sbi, raw_inode->i_nlink));
203 inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
204 inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
205 inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
206 inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
207 inode->i_ctime.tv_nsec = 0;
208 inode->i_atime.tv_nsec = 0;
209 inode->i_mtime.tv_nsec = 0;
210 inode->i_blocks = 0;
211
212 si = SYSV_I(inode);
213 for (block = 0; block < 10+1+1+1; block++)
214 read3byte(sbi, &raw_inode->i_data[3*block],
215 (u8 *)&si->i_data[block]);
216 brelse(bh);
217 si->i_dir_start_lookup = 0;
218 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
219 sysv_set_inode(inode,
220 old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
221 else
222 sysv_set_inode(inode, 0);
223 unlock_new_inode(inode);
224 return inode;
225
226 bad_inode:
227 iget_failed(inode);
228 return ERR_PTR(-EIO);
229 }
230
__sysv_write_inode(struct inode * inode,int wait)231 static int __sysv_write_inode(struct inode *inode, int wait)
232 {
233 struct super_block * sb = inode->i_sb;
234 struct sysv_sb_info * sbi = SYSV_SB(sb);
235 struct buffer_head * bh;
236 struct sysv_inode * raw_inode;
237 struct sysv_inode_info * si;
238 unsigned int ino, block;
239 int err = 0;
240
241 ino = inode->i_ino;
242 if (!ino || ino > sbi->s_ninodes) {
243 printk("Bad inode number on dev %s: %d is out of range\n",
244 inode->i_sb->s_id, ino);
245 return -EIO;
246 }
247 raw_inode = sysv_raw_inode(sb, ino, &bh);
248 if (!raw_inode) {
249 printk("unable to read i-node block\n");
250 return -EIO;
251 }
252
253 raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
254 raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(i_uid_read(inode)));
255 raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(i_gid_read(inode)));
256 raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
257 raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
258 raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
259 raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
260 raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
261
262 si = SYSV_I(inode);
263 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
264 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
265 for (block = 0; block < 10+1+1+1; block++)
266 write3byte(sbi, (u8 *)&si->i_data[block],
267 &raw_inode->i_data[3*block]);
268 mark_buffer_dirty(bh);
269 if (wait) {
270 sync_dirty_buffer(bh);
271 if (buffer_req(bh) && !buffer_uptodate(bh)) {
272 printk ("IO error syncing sysv inode [%s:%08x]\n",
273 sb->s_id, ino);
274 err = -EIO;
275 }
276 }
277 brelse(bh);
278 return err;
279 }
280
sysv_write_inode(struct inode * inode,struct writeback_control * wbc)281 int sysv_write_inode(struct inode *inode, struct writeback_control *wbc)
282 {
283 return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
284 }
285
sysv_sync_inode(struct inode * inode)286 int sysv_sync_inode(struct inode *inode)
287 {
288 return __sysv_write_inode(inode, 1);
289 }
290
sysv_evict_inode(struct inode * inode)291 static void sysv_evict_inode(struct inode *inode)
292 {
293 truncate_inode_pages_final(&inode->i_data);
294 if (!inode->i_nlink) {
295 inode->i_size = 0;
296 sysv_truncate(inode);
297 }
298 invalidate_inode_buffers(inode);
299 clear_inode(inode);
300 if (!inode->i_nlink)
301 sysv_free_inode(inode);
302 }
303
304 static struct kmem_cache *sysv_inode_cachep;
305
sysv_alloc_inode(struct super_block * sb)306 static struct inode *sysv_alloc_inode(struct super_block *sb)
307 {
308 struct sysv_inode_info *si;
309
310 si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
311 if (!si)
312 return NULL;
313 return &si->vfs_inode;
314 }
315
sysv_i_callback(struct rcu_head * head)316 static void sysv_i_callback(struct rcu_head *head)
317 {
318 struct inode *inode = container_of(head, struct inode, i_rcu);
319 kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
320 }
321
sysv_destroy_inode(struct inode * inode)322 static void sysv_destroy_inode(struct inode *inode)
323 {
324 call_rcu(&inode->i_rcu, sysv_i_callback);
325 }
326
init_once(void * p)327 static void init_once(void *p)
328 {
329 struct sysv_inode_info *si = (struct sysv_inode_info *)p;
330
331 inode_init_once(&si->vfs_inode);
332 }
333
334 const struct super_operations sysv_sops = {
335 .alloc_inode = sysv_alloc_inode,
336 .destroy_inode = sysv_destroy_inode,
337 .write_inode = sysv_write_inode,
338 .evict_inode = sysv_evict_inode,
339 .put_super = sysv_put_super,
340 .sync_fs = sysv_sync_fs,
341 .remount_fs = sysv_remount,
342 .statfs = sysv_statfs,
343 };
344
sysv_init_icache(void)345 int __init sysv_init_icache(void)
346 {
347 sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
348 sizeof(struct sysv_inode_info), 0,
349 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|SLAB_ACCOUNT,
350 init_once);
351 if (!sysv_inode_cachep)
352 return -ENOMEM;
353 return 0;
354 }
355
sysv_destroy_icache(void)356 void sysv_destroy_icache(void)
357 {
358 /*
359 * Make sure all delayed rcu free inodes are flushed before we
360 * destroy cache.
361 */
362 rcu_barrier();
363 kmem_cache_destroy(sysv_inode_cachep);
364 }
365