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->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
204 inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
205 inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
206 inode->i_ctime.tv_nsec = 0;
207 inode->i_atime.tv_nsec = 0;
208 inode->i_mtime.tv_nsec = 0;
209 inode->i_blocks = 0;
210
211 si = SYSV_I(inode);
212 for (block = 0; block < 10+1+1+1; block++)
213 read3byte(sbi, &raw_inode->i_data[3*block],
214 (u8 *)&si->i_data[block]);
215 brelse(bh);
216 si->i_dir_start_lookup = 0;
217 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
218 sysv_set_inode(inode,
219 old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
220 else
221 sysv_set_inode(inode, 0);
222 unlock_new_inode(inode);
223 return inode;
224
225 bad_inode:
226 iget_failed(inode);
227 return ERR_PTR(-EIO);
228 }
229
__sysv_write_inode(struct inode * inode,int wait)230 static int __sysv_write_inode(struct inode *inode, int wait)
231 {
232 struct super_block * sb = inode->i_sb;
233 struct sysv_sb_info * sbi = SYSV_SB(sb);
234 struct buffer_head * bh;
235 struct sysv_inode * raw_inode;
236 struct sysv_inode_info * si;
237 unsigned int ino, block;
238 int err = 0;
239
240 ino = inode->i_ino;
241 if (!ino || ino > sbi->s_ninodes) {
242 printk("Bad inode number on dev %s: %d is out of range\n",
243 inode->i_sb->s_id, ino);
244 return -EIO;
245 }
246 raw_inode = sysv_raw_inode(sb, ino, &bh);
247 if (!raw_inode) {
248 printk("unable to read i-node block\n");
249 return -EIO;
250 }
251
252 raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
253 raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(i_uid_read(inode)));
254 raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(i_gid_read(inode)));
255 raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
256 raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
257 raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
258 raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
259 raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
260
261 si = SYSV_I(inode);
262 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
263 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
264 for (block = 0; block < 10+1+1+1; block++)
265 write3byte(sbi, (u8 *)&si->i_data[block],
266 &raw_inode->i_data[3*block]);
267 mark_buffer_dirty(bh);
268 if (wait) {
269 sync_dirty_buffer(bh);
270 if (buffer_req(bh) && !buffer_uptodate(bh)) {
271 printk ("IO error syncing sysv inode [%s:%08x]\n",
272 sb->s_id, ino);
273 err = -EIO;
274 }
275 }
276 brelse(bh);
277 return err;
278 }
279
sysv_write_inode(struct inode * inode,struct writeback_control * wbc)280 int sysv_write_inode(struct inode *inode, struct writeback_control *wbc)
281 {
282 return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
283 }
284
sysv_sync_inode(struct inode * inode)285 int sysv_sync_inode(struct inode *inode)
286 {
287 return __sysv_write_inode(inode, 1);
288 }
289
sysv_evict_inode(struct inode * inode)290 static void sysv_evict_inode(struct inode *inode)
291 {
292 truncate_inode_pages_final(&inode->i_data);
293 if (!inode->i_nlink) {
294 inode->i_size = 0;
295 sysv_truncate(inode);
296 }
297 invalidate_inode_buffers(inode);
298 clear_inode(inode);
299 if (!inode->i_nlink)
300 sysv_free_inode(inode);
301 }
302
303 static struct kmem_cache *sysv_inode_cachep;
304
sysv_alloc_inode(struct super_block * sb)305 static struct inode *sysv_alloc_inode(struct super_block *sb)
306 {
307 struct sysv_inode_info *si;
308
309 si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
310 if (!si)
311 return NULL;
312 return &si->vfs_inode;
313 }
314
sysv_free_in_core_inode(struct inode * inode)315 static void sysv_free_in_core_inode(struct inode *inode)
316 {
317 kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
318 }
319
init_once(void * p)320 static void init_once(void *p)
321 {
322 struct sysv_inode_info *si = (struct sysv_inode_info *)p;
323
324 inode_init_once(&si->vfs_inode);
325 }
326
327 const struct super_operations sysv_sops = {
328 .alloc_inode = sysv_alloc_inode,
329 .free_inode = sysv_free_in_core_inode,
330 .write_inode = sysv_write_inode,
331 .evict_inode = sysv_evict_inode,
332 .put_super = sysv_put_super,
333 .sync_fs = sysv_sync_fs,
334 .remount_fs = sysv_remount,
335 .statfs = sysv_statfs,
336 };
337
sysv_init_icache(void)338 int __init sysv_init_icache(void)
339 {
340 sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
341 sizeof(struct sysv_inode_info), 0,
342 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|SLAB_ACCOUNT,
343 init_once);
344 if (!sysv_inode_cachep)
345 return -ENOMEM;
346 return 0;
347 }
348
sysv_destroy_icache(void)349 void sysv_destroy_icache(void)
350 {
351 /*
352 * Make sure all delayed rcu free inodes are flushed before we
353 * destroy cache.
354 */
355 rcu_barrier();
356 kmem_cache_destroy(sysv_inode_cachep);
357 }
358