inode.c 9.1 KB

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