1 /* 2 * linux/fs/ext2/ioctl.c 3 * 4 * Copyright (C) 1993, 1994, 1995 5 * Remy Card (card@masi.ibp.fr) 6 * Laboratoire MASI - Institut Blaise Pascal 7 * Universite Pierre et Marie Curie (Paris VI) 8 */ 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 <linux/smp_lock.h> 17 #include <asm/current.h> 18 #include <asm/uaccess.h> 19 20 21 long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 22 { 23 struct inode *inode = filp->f_dentry->d_inode; 24 struct ext2_inode_info *ei = EXT2_I(inode); 25 unsigned int flags; 26 unsigned short rsv_window_size; 27 int ret; 28 29 ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg); 30 31 switch (cmd) { 32 case EXT2_IOC_GETFLAGS: 33 ext2_get_inode_flags(ei); 34 flags = ei->i_flags & EXT2_FL_USER_VISIBLE; 35 return put_user(flags, (int __user *) arg); 36 case EXT2_IOC_SETFLAGS: { 37 unsigned int oldflags; 38 39 ret = mnt_want_write(filp->f_path.mnt); 40 if (ret) 41 return ret; 42 43 if (!is_owner_or_cap(inode)) { 44 ret = -EACCES; 45 goto setflags_out; 46 } 47 48 if (get_user(flags, (int __user *) arg)) { 49 ret = -EFAULT; 50 goto setflags_out; 51 } 52 53 if (!S_ISDIR(inode->i_mode)) 54 flags &= ~EXT2_DIRSYNC_FL; 55 56 mutex_lock(&inode->i_mutex); 57 /* Is it quota file? Do not allow user to mess with it */ 58 if (IS_NOQUOTA(inode)) { 59 mutex_unlock(&inode->i_mutex); 60 ret = -EPERM; 61 goto setflags_out; 62 } 63 oldflags = ei->i_flags; 64 65 /* 66 * The IMMUTABLE and APPEND_ONLY flags can only be changed by 67 * the relevant capability. 68 * 69 * This test looks nicer. Thanks to Pauline Middelink 70 */ 71 if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) { 72 if (!capable(CAP_LINUX_IMMUTABLE)) { 73 mutex_unlock(&inode->i_mutex); 74 ret = -EPERM; 75 goto setflags_out; 76 } 77 } 78 79 flags = flags & EXT2_FL_USER_MODIFIABLE; 80 flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE; 81 ei->i_flags = flags; 82 mutex_unlock(&inode->i_mutex); 83 84 ext2_set_inode_flags(inode); 85 inode->i_ctime = CURRENT_TIME_SEC; 86 mark_inode_dirty(inode); 87 setflags_out: 88 mnt_drop_write(filp->f_path.mnt); 89 return ret; 90 } 91 case EXT2_IOC_GETVERSION: 92 return put_user(inode->i_generation, (int __user *) arg); 93 case EXT2_IOC_SETVERSION: 94 if (!is_owner_or_cap(inode)) 95 return -EPERM; 96 ret = mnt_want_write(filp->f_path.mnt); 97 if (ret) 98 return ret; 99 if (get_user(inode->i_generation, (int __user *) arg)) { 100 ret = -EFAULT; 101 } else { 102 inode->i_ctime = CURRENT_TIME_SEC; 103 mark_inode_dirty(inode); 104 } 105 mnt_drop_write(filp->f_path.mnt); 106 return ret; 107 case EXT2_IOC_GETRSVSZ: 108 if (test_opt(inode->i_sb, RESERVATION) 109 && S_ISREG(inode->i_mode) 110 && ei->i_block_alloc_info) { 111 rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size; 112 return put_user(rsv_window_size, (int __user *)arg); 113 } 114 return -ENOTTY; 115 case EXT2_IOC_SETRSVSZ: { 116 117 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode)) 118 return -ENOTTY; 119 120 if (!is_owner_or_cap(inode)) 121 return -EACCES; 122 123 if (get_user(rsv_window_size, (int __user *)arg)) 124 return -EFAULT; 125 126 ret = mnt_want_write(filp->f_path.mnt); 127 if (ret) 128 return ret; 129 130 if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS) 131 rsv_window_size = EXT2_MAX_RESERVE_BLOCKS; 132 133 /* 134 * need to allocate reservation structure for this inode 135 * before set the window size 136 */ 137 /* 138 * XXX What lock should protect the rsv_goal_size? 139 * Accessed in ext2_get_block only. ext3 uses i_truncate. 140 */ 141 mutex_lock(&ei->truncate_mutex); 142 if (!ei->i_block_alloc_info) 143 ext2_init_block_alloc_info(inode); 144 145 if (ei->i_block_alloc_info){ 146 struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node; 147 rsv->rsv_goal_size = rsv_window_size; 148 } 149 mutex_unlock(&ei->truncate_mutex); 150 mnt_drop_write(filp->f_path.mnt); 151 return 0; 152 } 153 default: 154 return -ENOTTY; 155 } 156 } 157 158 #ifdef CONFIG_COMPAT 159 long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 160 { 161 /* These are just misnamed, they actually get/put from/to user an int */ 162 switch (cmd) { 163 case EXT2_IOC32_GETFLAGS: 164 cmd = EXT2_IOC_GETFLAGS; 165 break; 166 case EXT2_IOC32_SETFLAGS: 167 cmd = EXT2_IOC_SETFLAGS; 168 break; 169 case EXT2_IOC32_GETVERSION: 170 cmd = EXT2_IOC_GETVERSION; 171 break; 172 case EXT2_IOC32_SETVERSION: 173 cmd = EXT2_IOC_SETVERSION; 174 break; 175 default: 176 return -ENOIOCTLCMD; 177 } 178 return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg)); 179 } 180 #endif 181