ioctl.c 4.9 KB

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  1. /*
  2. * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
  3. */
  4. #include <linux/capability.h>
  5. #include <linux/fs.h>
  6. #include <linux/reiserfs_fs.h>
  7. #include <linux/time.h>
  8. #include <asm/uaccess.h>
  9. #include <linux/pagemap.h>
  10. #include <linux/smp_lock.h>
  11. #include <linux/compat.h>
  12. static int reiserfs_unpack(struct inode *inode, struct file *filp);
  13. /*
  14. ** reiserfs_ioctl - handler for ioctl for inode
  15. ** supported commands:
  16. ** 1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
  17. ** and prevent packing file (argument arg has to be non-zero)
  18. ** 2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
  19. ** 3) That's all for a while ...
  20. */
  21. int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
  22. unsigned long arg)
  23. {
  24. unsigned int flags;
  25. switch (cmd) {
  26. case REISERFS_IOC_UNPACK:
  27. if (S_ISREG(inode->i_mode)) {
  28. if (arg)
  29. return reiserfs_unpack(inode, filp);
  30. else
  31. return 0;
  32. } else
  33. return -ENOTTY;
  34. /* following two cases are taken from fs/ext2/ioctl.c by Remy
  35. Card (card@masi.ibp.fr) */
  36. case REISERFS_IOC_GETFLAGS:
  37. if (!reiserfs_attrs(inode->i_sb))
  38. return -ENOTTY;
  39. flags = REISERFS_I(inode)->i_attrs;
  40. i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
  41. return put_user(flags, (int __user *)arg);
  42. case REISERFS_IOC_SETFLAGS:{
  43. if (!reiserfs_attrs(inode->i_sb))
  44. return -ENOTTY;
  45. if (IS_RDONLY(inode))
  46. return -EROFS;
  47. if ((current->fsuid != inode->i_uid)
  48. && !capable(CAP_FOWNER))
  49. return -EPERM;
  50. if (get_user(flags, (int __user *)arg))
  51. return -EFAULT;
  52. if (((flags ^ REISERFS_I(inode)->
  53. i_attrs) & (REISERFS_IMMUTABLE_FL |
  54. REISERFS_APPEND_FL))
  55. && !capable(CAP_LINUX_IMMUTABLE))
  56. return -EPERM;
  57. if ((flags & REISERFS_NOTAIL_FL) &&
  58. S_ISREG(inode->i_mode)) {
  59. int result;
  60. result = reiserfs_unpack(inode, filp);
  61. if (result)
  62. return result;
  63. }
  64. sd_attrs_to_i_attrs(flags, inode);
  65. REISERFS_I(inode)->i_attrs = flags;
  66. inode->i_ctime = CURRENT_TIME_SEC;
  67. mark_inode_dirty(inode);
  68. return 0;
  69. }
  70. case REISERFS_IOC_GETVERSION:
  71. return put_user(inode->i_generation, (int __user *)arg);
  72. case REISERFS_IOC_SETVERSION:
  73. if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  74. return -EPERM;
  75. if (IS_RDONLY(inode))
  76. return -EROFS;
  77. if (get_user(inode->i_generation, (int __user *)arg))
  78. return -EFAULT;
  79. inode->i_ctime = CURRENT_TIME_SEC;
  80. mark_inode_dirty(inode);
  81. return 0;
  82. default:
  83. return -ENOTTY;
  84. }
  85. }
  86. #ifdef CONFIG_COMPAT
  87. long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
  88. unsigned long arg)
  89. {
  90. struct inode *inode = file->f_path.dentry->d_inode;
  91. int ret;
  92. /* These are just misnamed, they actually get/put from/to user an int */
  93. switch (cmd) {
  94. case REISERFS_IOC32_UNPACK:
  95. cmd = REISERFS_IOC_UNPACK;
  96. break;
  97. case REISERFS_IOC32_GETFLAGS:
  98. cmd = REISERFS_IOC_GETFLAGS;
  99. break;
  100. case REISERFS_IOC32_SETFLAGS:
  101. cmd = REISERFS_IOC_SETFLAGS;
  102. break;
  103. case REISERFS_IOC32_GETVERSION:
  104. cmd = REISERFS_IOC_GETVERSION;
  105. break;
  106. case REISERFS_IOC32_SETVERSION:
  107. cmd = REISERFS_IOC_SETVERSION;
  108. break;
  109. default:
  110. return -ENOIOCTLCMD;
  111. }
  112. lock_kernel();
  113. ret = reiserfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
  114. unlock_kernel();
  115. return ret;
  116. }
  117. #endif
  118. /*
  119. ** reiserfs_unpack
  120. ** Function try to convert tail from direct item into indirect.
  121. ** It set up nopack attribute in the REISERFS_I(inode)->nopack
  122. */
  123. static int reiserfs_unpack(struct inode *inode, struct file *filp)
  124. {
  125. int retval = 0;
  126. int index;
  127. struct page *page;
  128. struct address_space *mapping;
  129. unsigned long write_from;
  130. unsigned long blocksize = inode->i_sb->s_blocksize;
  131. if (inode->i_size == 0) {
  132. REISERFS_I(inode)->i_flags |= i_nopack_mask;
  133. return 0;
  134. }
  135. /* ioctl already done */
  136. if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
  137. return 0;
  138. }
  139. /* we need to make sure nobody is changing the file size beneath
  140. ** us
  141. */
  142. mutex_lock(&inode->i_mutex);
  143. reiserfs_write_lock(inode->i_sb);
  144. write_from = inode->i_size & (blocksize - 1);
  145. /* if we are on a block boundary, we are already unpacked. */
  146. if (write_from == 0) {
  147. REISERFS_I(inode)->i_flags |= i_nopack_mask;
  148. goto out;
  149. }
  150. /* we unpack by finding the page with the tail, and calling
  151. ** reiserfs_prepare_write on that page. This will force a
  152. ** reiserfs_get_block to unpack the tail for us.
  153. */
  154. index = inode->i_size >> PAGE_CACHE_SHIFT;
  155. mapping = inode->i_mapping;
  156. page = grab_cache_page(mapping, index);
  157. retval = -ENOMEM;
  158. if (!page) {
  159. goto out;
  160. }
  161. retval =
  162. mapping->a_ops->prepare_write(NULL, page, write_from, write_from);
  163. if (retval)
  164. goto out_unlock;
  165. /* conversion can change page contents, must flush */
  166. flush_dcache_page(page);
  167. retval =
  168. mapping->a_ops->commit_write(NULL, page, write_from, write_from);
  169. REISERFS_I(inode)->i_flags |= i_nopack_mask;
  170. out_unlock:
  171. unlock_page(page);
  172. page_cache_release(page);
  173. out:
  174. mutex_unlock(&inode->i_mutex);
  175. reiserfs_write_unlock(inode->i_sb);
  176. return retval;
  177. }