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 | |
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, n: *sbi->s_sb_time); |
48 | if (sbi->s_type == FSTYPE_SYSV4) { |
49 | if (*sbi->s_sb_state == cpu_to_fs32(sbi, n: 0x7c269d38u - old_time)) |
50 | *sbi->s_sb_state = cpu_to_fs32(sbi, n: 0x7c269d38u - time); |
51 | *sbi->s_sb_time = cpu_to_fs32(sbi, n: time); |
52 | mark_buffer_dirty(bh: sbi->s_bh2); |
53 | } |
54 | |
55 | mutex_unlock(lock: &sbi->s_lock); |
56 | |
57 | return 0; |
58 | } |
59 | |
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 | |
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(bh: sbi->s_bh1); |
77 | if (sbi->s_bh1 != sbi->s_bh2) |
78 | mark_buffer_dirty(bh: sbi->s_bh2); |
79 | } |
80 | |
81 | brelse(bh: sbi->s_bh1); |
82 | if (sbi->s_bh1 != sbi->s_bh2) |
83 | brelse(bh: sbi->s_bh2); |
84 | |
85 | kfree(objp: sbi); |
86 | } |
87 | |
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(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(v: id); |
102 | return 0; |
103 | } |
104 | |
105 | /* |
106 | * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32 |
107 | */ |
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 | |
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 | |
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 | |
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(error: -EIO); |
183 | } |
184 | |
185 | inode = iget_locked(sb, ino); |
186 | if (!inode) |
187 | return ERR_PTR(error: -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, n: raw_inode->i_mode); |
199 | i_uid_write(inode, uid: (uid_t)fs16_to_cpu(sbi, n: raw_inode->i_uid)); |
200 | i_gid_write(inode, gid: (gid_t)fs16_to_cpu(sbi, n: raw_inode->i_gid)); |
201 | set_nlink(inode, nlink: fs16_to_cpu(sbi, n: raw_inode->i_nlink)); |
202 | inode->i_size = fs32_to_cpu(sbi, n: raw_inode->i_size); |
203 | inode_set_atime(inode, sec: fs32_to_cpu(sbi, n: raw_inode->i_atime), nsec: 0); |
204 | inode_set_mtime(inode, sec: fs32_to_cpu(sbi, n: raw_inode->i_mtime), nsec: 0); |
205 | inode_set_ctime(inode, sec: fs32_to_cpu(sbi, n: raw_inode->i_ctime), nsec: 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, from: &raw_inode->i_data[3*block], |
211 | to: (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 | rdev: old_decode_dev(val: fs32_to_cpu(sbi, n: si->i_data[0]))); |
217 | else |
218 | sysv_set_inode(inode, rdev: 0); |
219 | unlock_new_inode(inode); |
220 | return inode; |
221 | |
222 | bad_inode: |
223 | iget_failed(inode); |
224 | return ERR_PTR(error: -EIO); |
225 | } |
226 | |
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, n: 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, n: inode->i_nlink); |
253 | raw_inode->i_size = cpu_to_fs32(sbi, n: inode->i_size); |
254 | raw_inode->i_atime = cpu_to_fs32(sbi, n: inode_get_atime_sec(inode)); |
255 | raw_inode->i_mtime = cpu_to_fs32(sbi, n: inode_get_mtime_sec(inode)); |
256 | raw_inode->i_ctime = cpu_to_fs32(sbi, n: 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, n: old_encode_dev(dev: inode->i_rdev)); |
261 | for (block = 0; block < 10+1+1+1; block++) |
262 | write3byte(sbi, from: (u8 *)&si->i_data[block], |
263 | to: &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 | |
277 | int sysv_write_inode(struct inode *inode, struct writeback_control *wbc) |
278 | { |
279 | return __sysv_write_inode(inode, wait: wbc->sync_mode == WB_SYNC_ALL); |
280 | } |
281 | |
282 | int sysv_sync_inode(struct inode *inode) |
283 | { |
284 | return __sysv_write_inode(inode, wait: 1); |
285 | } |
286 | |
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 | |
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, cache: sysv_inode_cachep, GFP_KERNEL); |
307 | if (!si) |
308 | return NULL; |
309 | return &si->vfs_inode; |
310 | } |
311 | |
312 | static void sysv_free_in_core_inode(struct inode *inode) |
313 | { |
314 | kmem_cache_free(s: sysv_inode_cachep, objp: SYSV_I(inode)); |
315 | } |
316 | |
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 | |
335 | int __init sysv_init_icache(void) |
336 | { |
337 | sysv_inode_cachep = kmem_cache_create(name: "sysv_inode_cache" , |
338 | size: sizeof(struct sysv_inode_info), align: 0, |
339 | SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|SLAB_ACCOUNT, |
340 | ctor: init_once); |
341 | if (!sysv_inode_cachep) |
342 | return -ENOMEM; |
343 | return 0; |
344 | } |
345 | |
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(s: sysv_inode_cachep); |
354 | } |
355 | |