ioctl.c 4.1 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * linux/fs/ext2/ioctl.c
  4. *
  5. * Copyright (C) 1993, 1994, 1995
  6. * Remy Card (card@masi.ibp.fr)
  7. * Laboratoire MASI - Institut Blaise Pascal
  8. * Universite Pierre et Marie Curie (Paris VI)
  9. */
  10. #include "ext2.h"
  11. #include <linux/capability.h>
  12. #include <linux/time.h>
  13. #include <linux/sched.h>
  14. #include <linux/compat.h>
  15. #include <linux/mount.h>
  16. #include <asm/current.h>
  17. #include <linux/uaccess.h>
  18. long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  19. {
  20. struct inode *inode = file_inode(filp);
  21. struct ext2_inode_info *ei = EXT2_I(inode);
  22. unsigned int flags;
  23. unsigned short rsv_window_size;
  24. int ret;
  25. ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  26. switch (cmd) {
  27. case EXT2_IOC_GETFLAGS:
  28. flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
  29. return put_user(flags, (int __user *) arg);
  30. case EXT2_IOC_SETFLAGS: {
  31. unsigned int oldflags;
  32. ret = mnt_want_write_file(filp);
  33. if (ret)
  34. return ret;
  35. if (!inode_owner_or_capable(inode)) {
  36. ret = -EACCES;
  37. goto setflags_out;
  38. }
  39. if (get_user(flags, (int __user *) arg)) {
  40. ret = -EFAULT;
  41. goto setflags_out;
  42. }
  43. flags = ext2_mask_flags(inode->i_mode, flags);
  44. inode_lock(inode);
  45. /* Is it quota file? Do not allow user to mess with it */
  46. if (IS_NOQUOTA(inode)) {
  47. inode_unlock(inode);
  48. ret = -EPERM;
  49. goto setflags_out;
  50. }
  51. oldflags = ei->i_flags;
  52. ret = vfs_ioc_setflags_prepare(inode, oldflags, flags);
  53. if (ret) {
  54. inode_unlock(inode);
  55. goto setflags_out;
  56. }
  57. flags = flags & EXT2_FL_USER_MODIFIABLE;
  58. flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
  59. ei->i_flags = flags;
  60. ext2_set_inode_flags(inode);
  61. inode->i_ctime = current_time(inode);
  62. inode_unlock(inode);
  63. mark_inode_dirty(inode);
  64. setflags_out:
  65. mnt_drop_write_file(filp);
  66. return ret;
  67. }
  68. case EXT2_IOC_GETVERSION:
  69. return put_user(inode->i_generation, (int __user *) arg);
  70. case EXT2_IOC_SETVERSION: {
  71. __u32 generation;
  72. if (!inode_owner_or_capable(inode))
  73. return -EPERM;
  74. ret = mnt_want_write_file(filp);
  75. if (ret)
  76. return ret;
  77. if (get_user(generation, (int __user *) arg)) {
  78. ret = -EFAULT;
  79. goto setversion_out;
  80. }
  81. inode_lock(inode);
  82. inode->i_ctime = current_time(inode);
  83. inode->i_generation = generation;
  84. inode_unlock(inode);
  85. mark_inode_dirty(inode);
  86. setversion_out:
  87. mnt_drop_write_file(filp);
  88. return ret;
  89. }
  90. case EXT2_IOC_GETRSVSZ:
  91. if (test_opt(inode->i_sb, RESERVATION)
  92. && S_ISREG(inode->i_mode)
  93. && ei->i_block_alloc_info) {
  94. rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
  95. return put_user(rsv_window_size, (int __user *)arg);
  96. }
  97. return -ENOTTY;
  98. case EXT2_IOC_SETRSVSZ: {
  99. if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
  100. return -ENOTTY;
  101. if (!inode_owner_or_capable(inode))
  102. return -EACCES;
  103. if (get_user(rsv_window_size, (int __user *)arg))
  104. return -EFAULT;
  105. ret = mnt_want_write_file(filp);
  106. if (ret)
  107. return ret;
  108. if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
  109. rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
  110. /*
  111. * need to allocate reservation structure for this inode
  112. * before set the window size
  113. */
  114. /*
  115. * XXX What lock should protect the rsv_goal_size?
  116. * Accessed in ext2_get_block only. ext3 uses i_truncate.
  117. */
  118. mutex_lock(&ei->truncate_mutex);
  119. if (!ei->i_block_alloc_info)
  120. ext2_init_block_alloc_info(inode);
  121. if (ei->i_block_alloc_info){
  122. struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
  123. rsv->rsv_goal_size = rsv_window_size;
  124. } else {
  125. ret = -ENOMEM;
  126. }
  127. mutex_unlock(&ei->truncate_mutex);
  128. mnt_drop_write_file(filp);
  129. return ret;
  130. }
  131. default:
  132. return -ENOTTY;
  133. }
  134. }
  135. #ifdef CONFIG_COMPAT
  136. long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  137. {
  138. /* These are just misnamed, they actually get/put from/to user an int */
  139. switch (cmd) {
  140. case EXT2_IOC32_GETFLAGS:
  141. cmd = EXT2_IOC_GETFLAGS;
  142. break;
  143. case EXT2_IOC32_SETFLAGS:
  144. cmd = EXT2_IOC_SETFLAGS;
  145. break;
  146. case EXT2_IOC32_GETVERSION:
  147. cmd = EXT2_IOC_GETVERSION;
  148. break;
  149. case EXT2_IOC32_SETVERSION:
  150. cmd = EXT2_IOC_SETVERSION;
  151. break;
  152. default:
  153. return -ENOIOCTLCMD;
  154. }
  155. return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
  156. }
  157. #endif