vfs_super.c 6.1 KB

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  1. /*
  2. * linux/fs/9p/vfs_super.c
  3. *
  4. * This file contians superblock ops for 9P2000. It is intended that
  5. * you mount this file system on directories.
  6. *
  7. * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
  8. * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
  9. *
  10. * This program is free software; you can redistribute it and/or modify
  11. * it under the terms of the GNU General Public License version 2
  12. * as published by the Free Software Foundation.
  13. *
  14. * This program is distributed in the hope that it will be useful,
  15. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17. * GNU General Public License for more details.
  18. *
  19. * You should have received a copy of the GNU General Public License
  20. * along with this program; if not, write to:
  21. * Free Software Foundation
  22. * 51 Franklin Street, Fifth Floor
  23. * Boston, MA 02111-1301 USA
  24. *
  25. */
  26. #include <linux/kernel.h>
  27. #include <linux/config.h>
  28. #include <linux/module.h>
  29. #include <linux/errno.h>
  30. #include <linux/fs.h>
  31. #include <linux/file.h>
  32. #include <linux/stat.h>
  33. #include <linux/string.h>
  34. #include <linux/smp_lock.h>
  35. #include <linux/inet.h>
  36. #include <linux/pagemap.h>
  37. #include <linux/seq_file.h>
  38. #include <linux/mount.h>
  39. #include <linux/idr.h>
  40. #include "debug.h"
  41. #include "v9fs.h"
  42. #include "9p.h"
  43. #include "v9fs_vfs.h"
  44. #include "fid.h"
  45. static void v9fs_clear_inode(struct inode *);
  46. static struct super_operations v9fs_super_ops;
  47. /**
  48. * v9fs_clear_inode - release an inode
  49. * @inode: inode to release
  50. *
  51. */
  52. static void v9fs_clear_inode(struct inode *inode)
  53. {
  54. filemap_fdatawrite(inode->i_mapping);
  55. }
  56. /**
  57. * v9fs_set_super - set the superblock
  58. * @s: super block
  59. * @data: file system specific data
  60. *
  61. */
  62. static int v9fs_set_super(struct super_block *s, void *data)
  63. {
  64. s->s_fs_info = data;
  65. return set_anon_super(s, data);
  66. }
  67. /**
  68. * v9fs_fill_super - populate superblock with info
  69. * @sb: superblock
  70. * @v9ses: session information
  71. *
  72. */
  73. static void
  74. v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
  75. int flags)
  76. {
  77. sb->s_maxbytes = MAX_LFS_FILESIZE;
  78. sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
  79. sb->s_blocksize = 1 << sb->s_blocksize_bits;
  80. sb->s_magic = V9FS_MAGIC;
  81. sb->s_op = &v9fs_super_ops;
  82. sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
  83. MS_NOATIME;
  84. }
  85. /**
  86. * v9fs_get_sb - mount a superblock
  87. * @fs_type: file system type
  88. * @flags: mount flags
  89. * @dev_name: device name that was mounted
  90. * @data: mount options
  91. *
  92. */
  93. static struct super_block *v9fs_get_sb(struct file_system_type
  94. *fs_type, int flags,
  95. const char *dev_name, void *data)
  96. {
  97. struct super_block *sb = NULL;
  98. struct v9fs_fcall *fcall = NULL;
  99. struct inode *inode = NULL;
  100. struct dentry *root = NULL;
  101. struct v9fs_session_info *v9ses = NULL;
  102. struct v9fs_fid *root_fid = NULL;
  103. int mode = S_IRWXUGO | S_ISVTX;
  104. uid_t uid = current->fsuid;
  105. gid_t gid = current->fsgid;
  106. int stat_result = 0;
  107. int newfid = 0;
  108. int retval = 0;
  109. dprintk(DEBUG_VFS, " \n");
  110. v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
  111. if (!v9ses)
  112. return ERR_PTR(-ENOMEM);
  113. if ((newfid = v9fs_session_init(v9ses, dev_name, data)) < 0) {
  114. dprintk(DEBUG_ERROR, "problem initiating session\n");
  115. kfree(v9ses);
  116. return ERR_PTR(newfid);
  117. }
  118. sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
  119. v9fs_fill_super(sb, v9ses, flags);
  120. inode = v9fs_get_inode(sb, S_IFDIR | mode);
  121. if (IS_ERR(inode)) {
  122. retval = PTR_ERR(inode);
  123. goto put_back_sb;
  124. }
  125. inode->i_uid = uid;
  126. inode->i_gid = gid;
  127. root = d_alloc_root(inode);
  128. if (!root) {
  129. retval = -ENOMEM;
  130. goto put_back_sb;
  131. }
  132. sb->s_root = root;
  133. stat_result = v9fs_t_stat(v9ses, newfid, &fcall);
  134. if (stat_result < 0) {
  135. dprintk(DEBUG_ERROR, "stat error\n");
  136. v9fs_t_clunk(v9ses, newfid);
  137. } else {
  138. /* Setup the Root Inode */
  139. root_fid = v9fs_fid_create(v9ses, newfid);
  140. if (root_fid == NULL) {
  141. retval = -ENOMEM;
  142. goto put_back_sb;
  143. }
  144. retval = v9fs_fid_insert(root_fid, root);
  145. if (retval < 0) {
  146. kfree(fcall);
  147. goto put_back_sb;
  148. }
  149. root_fid->qid = fcall->params.rstat.stat.qid;
  150. root->d_inode->i_ino =
  151. v9fs_qid2ino(&fcall->params.rstat.stat.qid);
  152. v9fs_stat2inode(&fcall->params.rstat.stat, root->d_inode, sb);
  153. }
  154. kfree(fcall);
  155. if (stat_result < 0) {
  156. retval = stat_result;
  157. goto put_back_sb;
  158. }
  159. return sb;
  160. put_back_sb:
  161. /* deactivate_super calls v9fs_kill_super which will frees the rest */
  162. up_write(&sb->s_umount);
  163. deactivate_super(sb);
  164. return ERR_PTR(retval);
  165. }
  166. /**
  167. * v9fs_kill_super - Kill Superblock
  168. * @s: superblock
  169. *
  170. */
  171. static void v9fs_kill_super(struct super_block *s)
  172. {
  173. struct v9fs_session_info *v9ses = s->s_fs_info;
  174. dprintk(DEBUG_VFS, " %p\n", s);
  175. v9fs_dentry_release(s->s_root); /* clunk root */
  176. kill_anon_super(s);
  177. v9fs_session_close(v9ses);
  178. kfree(v9ses);
  179. dprintk(DEBUG_VFS, "exiting kill_super\n");
  180. }
  181. /**
  182. * v9fs_show_options - Show mount options in /proc/mounts
  183. * @m: seq_file to write to
  184. * @mnt: mount descriptor
  185. *
  186. */
  187. static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt)
  188. {
  189. struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info;
  190. if (v9ses->debug != 0)
  191. seq_printf(m, ",debug=%u", v9ses->debug);
  192. if (v9ses->port != V9FS_PORT)
  193. seq_printf(m, ",port=%u", v9ses->port);
  194. if (v9ses->maxdata != 9000)
  195. seq_printf(m, ",msize=%u", v9ses->maxdata);
  196. if (v9ses->afid != ~0)
  197. seq_printf(m, ",afid=%u", v9ses->afid);
  198. if (v9ses->proto == PROTO_UNIX)
  199. seq_puts(m, ",proto=unix");
  200. if (v9ses->extended == 0)
  201. seq_puts(m, ",noextend");
  202. if (v9ses->nodev == 1)
  203. seq_puts(m, ",nodevmap");
  204. seq_printf(m, ",name=%s", v9ses->name);
  205. seq_printf(m, ",aname=%s", v9ses->remotename);
  206. seq_printf(m, ",uid=%u", v9ses->uid);
  207. seq_printf(m, ",gid=%u", v9ses->gid);
  208. return 0;
  209. }
  210. static void
  211. v9fs_umount_begin(struct super_block *sb)
  212. {
  213. struct v9fs_session_info *v9ses = sb->s_fs_info;
  214. v9fs_session_cancel(v9ses);
  215. }
  216. static struct super_operations v9fs_super_ops = {
  217. .statfs = simple_statfs,
  218. .clear_inode = v9fs_clear_inode,
  219. .show_options = v9fs_show_options,
  220. .umount_begin = v9fs_umount_begin,
  221. };
  222. struct file_system_type v9fs_fs_type = {
  223. .name = "9p",
  224. .get_sb = v9fs_get_sb,
  225. .kill_sb = v9fs_kill_super,
  226. .owner = THIS_MODULE,
  227. };