vfs_super.c 6.4 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/module.h>
  28. #include <linux/errno.h>
  29. #include <linux/fs.h>
  30. #include <linux/file.h>
  31. #include <linux/stat.h>
  32. #include <linux/string.h>
  33. #include <linux/smp_lock.h>
  34. #include <linux/inet.h>
  35. #include <linux/pagemap.h>
  36. #include <linux/seq_file.h>
  37. #include <linux/mount.h>
  38. #include <linux/idr.h>
  39. #include "debug.h"
  40. #include "v9fs.h"
  41. #include "9p.h"
  42. #include "v9fs_vfs.h"
  43. #include "fid.h"
  44. static void v9fs_clear_inode(struct inode *);
  45. static const struct super_operations v9fs_super_ops;
  46. /**
  47. * v9fs_clear_inode - release an inode
  48. * @inode: inode to release
  49. *
  50. */
  51. static void v9fs_clear_inode(struct inode *inode)
  52. {
  53. filemap_fdatawrite(inode->i_mapping);
  54. }
  55. /**
  56. * v9fs_set_super - set the superblock
  57. * @s: super block
  58. * @data: file system specific data
  59. *
  60. */
  61. static int v9fs_set_super(struct super_block *s, void *data)
  62. {
  63. s->s_fs_info = data;
  64. return set_anon_super(s, data);
  65. }
  66. /**
  67. * v9fs_fill_super - populate superblock with info
  68. * @sb: superblock
  69. * @v9ses: session information
  70. *
  71. */
  72. static void
  73. v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
  74. int flags)
  75. {
  76. sb->s_maxbytes = MAX_LFS_FILESIZE;
  77. sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
  78. sb->s_blocksize = 1 << sb->s_blocksize_bits;
  79. sb->s_magic = V9FS_MAGIC;
  80. sb->s_op = &v9fs_super_ops;
  81. sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
  82. MS_NOATIME;
  83. }
  84. /**
  85. * v9fs_get_sb - mount a superblock
  86. * @fs_type: file system type
  87. * @flags: mount flags
  88. * @dev_name: device name that was mounted
  89. * @data: mount options
  90. * @mnt: mountpoint record to be instantiated
  91. *
  92. */
  93. static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
  94. const char *dev_name, void *data,
  95. struct vfsmount *mnt)
  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 -ENOMEM;
  113. if ((newfid = v9fs_session_init(v9ses, dev_name, data)) < 0) {
  114. dprintk(DEBUG_ERROR, "problem initiating session\n");
  115. retval = newfid;
  116. goto out_free_session;
  117. }
  118. sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
  119. if (IS_ERR(sb)) {
  120. retval = PTR_ERR(sb);
  121. goto out_close_session;
  122. }
  123. v9fs_fill_super(sb, v9ses, flags);
  124. inode = v9fs_get_inode(sb, S_IFDIR | mode);
  125. if (IS_ERR(inode)) {
  126. retval = PTR_ERR(inode);
  127. goto put_back_sb;
  128. }
  129. inode->i_uid = uid;
  130. inode->i_gid = gid;
  131. root = d_alloc_root(inode);
  132. if (!root) {
  133. retval = -ENOMEM;
  134. goto put_back_sb;
  135. }
  136. sb->s_root = root;
  137. stat_result = v9fs_t_stat(v9ses, newfid, &fcall);
  138. if (stat_result < 0) {
  139. dprintk(DEBUG_ERROR, "stat error\n");
  140. v9fs_t_clunk(v9ses, newfid);
  141. } else {
  142. /* Setup the Root Inode */
  143. root_fid = v9fs_fid_create(v9ses, newfid);
  144. if (root_fid == NULL) {
  145. retval = -ENOMEM;
  146. goto put_back_sb;
  147. }
  148. retval = v9fs_fid_insert(root_fid, root);
  149. if (retval < 0) {
  150. kfree(fcall);
  151. goto put_back_sb;
  152. }
  153. root_fid->qid = fcall->params.rstat.stat.qid;
  154. root->d_inode->i_ino =
  155. v9fs_qid2ino(&fcall->params.rstat.stat.qid);
  156. v9fs_stat2inode(&fcall->params.rstat.stat, root->d_inode, sb);
  157. }
  158. kfree(fcall);
  159. if (stat_result < 0) {
  160. retval = stat_result;
  161. goto put_back_sb;
  162. }
  163. return simple_set_mnt(mnt, sb);
  164. out_close_session:
  165. v9fs_session_close(v9ses);
  166. out_free_session:
  167. kfree(v9ses);
  168. return retval;
  169. put_back_sb:
  170. /* deactivate_super calls v9fs_kill_super which will frees the rest */
  171. up_write(&sb->s_umount);
  172. deactivate_super(sb);
  173. return retval;
  174. }
  175. /**
  176. * v9fs_kill_super - Kill Superblock
  177. * @s: superblock
  178. *
  179. */
  180. static void v9fs_kill_super(struct super_block *s)
  181. {
  182. struct v9fs_session_info *v9ses = s->s_fs_info;
  183. dprintk(DEBUG_VFS, " %p\n", s);
  184. v9fs_dentry_release(s->s_root); /* clunk root */
  185. kill_anon_super(s);
  186. v9fs_session_close(v9ses);
  187. kfree(v9ses);
  188. dprintk(DEBUG_VFS, "exiting kill_super\n");
  189. }
  190. /**
  191. * v9fs_show_options - Show mount options in /proc/mounts
  192. * @m: seq_file to write to
  193. * @mnt: mount descriptor
  194. *
  195. */
  196. static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt)
  197. {
  198. struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info;
  199. if (v9ses->debug != 0)
  200. seq_printf(m, ",debug=%u", v9ses->debug);
  201. if (v9ses->port != V9FS_PORT)
  202. seq_printf(m, ",port=%u", v9ses->port);
  203. if (v9ses->maxdata != 9000)
  204. seq_printf(m, ",msize=%u", v9ses->maxdata);
  205. if (v9ses->afid != ~0)
  206. seq_printf(m, ",afid=%u", v9ses->afid);
  207. if (v9ses->proto == PROTO_UNIX)
  208. seq_puts(m, ",proto=unix");
  209. if (v9ses->extended == 0)
  210. seq_puts(m, ",noextend");
  211. if (v9ses->nodev == 1)
  212. seq_puts(m, ",nodevmap");
  213. seq_printf(m, ",name=%s", v9ses->name);
  214. seq_printf(m, ",aname=%s", v9ses->remotename);
  215. seq_printf(m, ",uid=%u", v9ses->uid);
  216. seq_printf(m, ",gid=%u", v9ses->gid);
  217. return 0;
  218. }
  219. static void
  220. v9fs_umount_begin(struct vfsmount *vfsmnt, int flags)
  221. {
  222. struct v9fs_session_info *v9ses = vfsmnt->mnt_sb->s_fs_info;
  223. if (flags & MNT_FORCE)
  224. v9fs_session_cancel(v9ses);
  225. }
  226. static const struct super_operations v9fs_super_ops = {
  227. .statfs = simple_statfs,
  228. .clear_inode = v9fs_clear_inode,
  229. .show_options = v9fs_show_options,
  230. .umount_begin = v9fs_umount_begin,
  231. };
  232. struct file_system_type v9fs_fs_type = {
  233. .name = "9p",
  234. .get_sb = v9fs_get_sb,
  235. .kill_sb = v9fs_kill_super,
  236. .owner = THIS_MODULE,
  237. };