inode.c 7.3 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * Super block/filesystem wide operations
  4. *
  5. * Copyright (C) 1996 Peter J. Braam <[email protected]> and
  6. * Michael Callahan <[email protected]>
  7. *
  8. * Rewritten for Linux 2.1. Peter Braam <[email protected]>
  9. * Copyright (C) Carnegie Mellon University
  10. */
  11. #include <linux/module.h>
  12. #include <linux/kernel.h>
  13. #include <linux/mm.h>
  14. #include <linux/string.h>
  15. #include <linux/stat.h>
  16. #include <linux/errno.h>
  17. #include <linux/unistd.h>
  18. #include <linux/mutex.h>
  19. #include <linux/spinlock.h>
  20. #include <linux/file.h>
  21. #include <linux/vfs.h>
  22. #include <linux/slab.h>
  23. #include <linux/pid_namespace.h>
  24. #include <linux/uaccess.h>
  25. #include <linux/fs.h>
  26. #include <linux/vmalloc.h>
  27. #include <linux/coda.h>
  28. #include "coda_psdev.h"
  29. #include "coda_linux.h"
  30. #include "coda_cache.h"
  31. #include "coda_int.h"
  32. /* VFS super_block ops */
  33. static void coda_evict_inode(struct inode *);
  34. static void coda_put_super(struct super_block *);
  35. static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
  36. static struct kmem_cache * coda_inode_cachep;
  37. static struct inode *coda_alloc_inode(struct super_block *sb)
  38. {
  39. struct coda_inode_info *ei;
  40. ei = alloc_inode_sb(sb, coda_inode_cachep, GFP_KERNEL);
  41. if (!ei)
  42. return NULL;
  43. memset(&ei->c_fid, 0, sizeof(struct CodaFid));
  44. ei->c_flags = 0;
  45. ei->c_uid = GLOBAL_ROOT_UID;
  46. ei->c_cached_perm = 0;
  47. spin_lock_init(&ei->c_lock);
  48. return &ei->vfs_inode;
  49. }
  50. static void coda_free_inode(struct inode *inode)
  51. {
  52. kmem_cache_free(coda_inode_cachep, ITOC(inode));
  53. }
  54. static void init_once(void *foo)
  55. {
  56. struct coda_inode_info *ei = (struct coda_inode_info *) foo;
  57. inode_init_once(&ei->vfs_inode);
  58. }
  59. int __init coda_init_inodecache(void)
  60. {
  61. coda_inode_cachep = kmem_cache_create("coda_inode_cache",
  62. sizeof(struct coda_inode_info), 0,
  63. SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
  64. SLAB_ACCOUNT, init_once);
  65. if (coda_inode_cachep == NULL)
  66. return -ENOMEM;
  67. return 0;
  68. }
  69. void coda_destroy_inodecache(void)
  70. {
  71. /*
  72. * Make sure all delayed rcu free inodes are flushed before we
  73. * destroy cache.
  74. */
  75. rcu_barrier();
  76. kmem_cache_destroy(coda_inode_cachep);
  77. }
  78. static int coda_remount(struct super_block *sb, int *flags, char *data)
  79. {
  80. sync_filesystem(sb);
  81. *flags |= SB_NOATIME;
  82. return 0;
  83. }
  84. /* exported operations */
  85. static const struct super_operations coda_super_operations =
  86. {
  87. .alloc_inode = coda_alloc_inode,
  88. .free_inode = coda_free_inode,
  89. .evict_inode = coda_evict_inode,
  90. .put_super = coda_put_super,
  91. .statfs = coda_statfs,
  92. .remount_fs = coda_remount,
  93. };
  94. static int get_device_index(struct coda_mount_data *data)
  95. {
  96. struct fd f;
  97. struct inode *inode;
  98. int idx;
  99. if (data == NULL) {
  100. pr_warn("%s: Bad mount data\n", __func__);
  101. return -1;
  102. }
  103. if (data->version != CODA_MOUNT_VERSION) {
  104. pr_warn("%s: Bad mount version\n", __func__);
  105. return -1;
  106. }
  107. f = fdget(data->fd);
  108. if (!f.file)
  109. goto Ebadf;
  110. inode = file_inode(f.file);
  111. if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
  112. fdput(f);
  113. goto Ebadf;
  114. }
  115. idx = iminor(inode);
  116. fdput(f);
  117. if (idx < 0 || idx >= MAX_CODADEVS) {
  118. pr_warn("%s: Bad minor number\n", __func__);
  119. return -1;
  120. }
  121. return idx;
  122. Ebadf:
  123. pr_warn("%s: Bad file\n", __func__);
  124. return -1;
  125. }
  126. static int coda_fill_super(struct super_block *sb, void *data, int silent)
  127. {
  128. struct inode *root = NULL;
  129. struct venus_comm *vc;
  130. struct CodaFid fid;
  131. int error;
  132. int idx;
  133. if (task_active_pid_ns(current) != &init_pid_ns)
  134. return -EINVAL;
  135. idx = get_device_index((struct coda_mount_data *) data);
  136. /* Ignore errors in data, for backward compatibility */
  137. if(idx == -1)
  138. idx = 0;
  139. pr_info("%s: device index: %i\n", __func__, idx);
  140. vc = &coda_comms[idx];
  141. mutex_lock(&vc->vc_mutex);
  142. if (!vc->vc_inuse) {
  143. pr_warn("%s: No pseudo device\n", __func__);
  144. error = -EINVAL;
  145. goto unlock_out;
  146. }
  147. if (vc->vc_sb) {
  148. pr_warn("%s: Device already mounted\n", __func__);
  149. error = -EBUSY;
  150. goto unlock_out;
  151. }
  152. vc->vc_sb = sb;
  153. mutex_unlock(&vc->vc_mutex);
  154. sb->s_fs_info = vc;
  155. sb->s_flags |= SB_NOATIME;
  156. sb->s_blocksize = 4096; /* XXXXX what do we put here?? */
  157. sb->s_blocksize_bits = 12;
  158. sb->s_magic = CODA_SUPER_MAGIC;
  159. sb->s_op = &coda_super_operations;
  160. sb->s_d_op = &coda_dentry_operations;
  161. sb->s_time_gran = 1;
  162. sb->s_time_min = S64_MIN;
  163. sb->s_time_max = S64_MAX;
  164. error = super_setup_bdi(sb);
  165. if (error)
  166. goto error;
  167. /* get root fid from Venus: this needs the root inode */
  168. error = venus_rootfid(sb, &fid);
  169. if ( error ) {
  170. pr_warn("%s: coda_get_rootfid failed with %d\n",
  171. __func__, error);
  172. goto error;
  173. }
  174. pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
  175. /* make root inode */
  176. root = coda_cnode_make(&fid, sb);
  177. if (IS_ERR(root)) {
  178. error = PTR_ERR(root);
  179. pr_warn("Failure of coda_cnode_make for root: error %d\n",
  180. error);
  181. goto error;
  182. }
  183. pr_info("%s: rootinode is %ld dev %s\n",
  184. __func__, root->i_ino, root->i_sb->s_id);
  185. sb->s_root = d_make_root(root);
  186. if (!sb->s_root) {
  187. error = -EINVAL;
  188. goto error;
  189. }
  190. return 0;
  191. error:
  192. mutex_lock(&vc->vc_mutex);
  193. vc->vc_sb = NULL;
  194. sb->s_fs_info = NULL;
  195. unlock_out:
  196. mutex_unlock(&vc->vc_mutex);
  197. return error;
  198. }
  199. static void coda_put_super(struct super_block *sb)
  200. {
  201. struct venus_comm *vcp = coda_vcp(sb);
  202. mutex_lock(&vcp->vc_mutex);
  203. vcp->vc_sb = NULL;
  204. sb->s_fs_info = NULL;
  205. mutex_unlock(&vcp->vc_mutex);
  206. mutex_destroy(&vcp->vc_mutex);
  207. pr_info("Bye bye.\n");
  208. }
  209. static void coda_evict_inode(struct inode *inode)
  210. {
  211. truncate_inode_pages_final(&inode->i_data);
  212. clear_inode(inode);
  213. coda_cache_clear_inode(inode);
  214. }
  215. int coda_getattr(struct user_namespace *mnt_userns, const struct path *path,
  216. struct kstat *stat, u32 request_mask, unsigned int flags)
  217. {
  218. int err = coda_revalidate_inode(d_inode(path->dentry));
  219. if (!err)
  220. generic_fillattr(&init_user_ns, d_inode(path->dentry), stat);
  221. return err;
  222. }
  223. int coda_setattr(struct user_namespace *mnt_userns, struct dentry *de,
  224. struct iattr *iattr)
  225. {
  226. struct inode *inode = d_inode(de);
  227. struct coda_vattr vattr;
  228. int error;
  229. memset(&vattr, 0, sizeof(vattr));
  230. inode->i_ctime = current_time(inode);
  231. coda_iattr_to_vattr(iattr, &vattr);
  232. vattr.va_type = C_VNON; /* cannot set type */
  233. /* Venus is responsible for truncating the container-file!!! */
  234. error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
  235. if (!error) {
  236. coda_vattr_to_iattr(inode, &vattr);
  237. coda_cache_clear_inode(inode);
  238. }
  239. return error;
  240. }
  241. const struct inode_operations coda_file_inode_operations = {
  242. .permission = coda_permission,
  243. .getattr = coda_getattr,
  244. .setattr = coda_setattr,
  245. };
  246. static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
  247. {
  248. int error;
  249. error = venus_statfs(dentry, buf);
  250. if (error) {
  251. /* fake something like AFS does */
  252. buf->f_blocks = 9000000;
  253. buf->f_bfree = 9000000;
  254. buf->f_bavail = 9000000;
  255. buf->f_files = 9000000;
  256. buf->f_ffree = 9000000;
  257. }
  258. /* and fill in the rest */
  259. buf->f_type = CODA_SUPER_MAGIC;
  260. buf->f_bsize = 4096;
  261. buf->f_namelen = CODA_MAXNAMLEN;
  262. return 0;
  263. }
  264. /* init_coda: used by filesystems.c to register coda */
  265. static struct dentry *coda_mount(struct file_system_type *fs_type,
  266. int flags, const char *dev_name, void *data)
  267. {
  268. return mount_nodev(fs_type, flags, data, coda_fill_super);
  269. }
  270. struct file_system_type coda_fs_type = {
  271. .owner = THIS_MODULE,
  272. .name = "coda",
  273. .mount = coda_mount,
  274. .kill_sb = kill_anon_super,
  275. .fs_flags = FS_BINARY_MOUNTDATA,
  276. };
  277. MODULE_ALIAS_FS("coda");