1 /* 2 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README 3 */ 4 5 #include <linux/capability.h> 6 #include <linux/fs.h> 7 #include <linux/reiserfs_fs.h> 8 #include <linux/time.h> 9 #include <asm/uaccess.h> 10 #include <linux/pagemap.h> 11 #include <linux/smp_lock.h> 12 #include <linux/compat.h> 13 14 static int reiserfs_unpack(struct inode *inode, struct file *filp); 15 16 /* 17 ** reiserfs_ioctl - handler for ioctl for inode 18 ** supported commands: 19 ** 1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect 20 ** and prevent packing file (argument arg has to be non-zero) 21 ** 2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION 22 ** 3) That's all for a while ... 23 */ 24 int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, 25 unsigned long arg) 26 { 27 unsigned int flags; 28 29 switch (cmd) { 30 case REISERFS_IOC_UNPACK: 31 if (S_ISREG(inode->i_mode)) { 32 if (arg) 33 return reiserfs_unpack(inode, filp); 34 else 35 return 0; 36 } else 37 return -ENOTTY; 38 /* following two cases are taken from fs/ext2/ioctl.c by Remy 39 Card (card@masi.ibp.fr) */ 40 case REISERFS_IOC_GETFLAGS: 41 if (!reiserfs_attrs(inode->i_sb)) 42 return -ENOTTY; 43 44 flags = REISERFS_I(inode)->i_attrs; 45 i_attrs_to_sd_attrs(inode, (__u16 *) & flags); 46 return put_user(flags, (int __user *)arg); 47 case REISERFS_IOC_SETFLAGS:{ 48 if (!reiserfs_attrs(inode->i_sb)) 49 return -ENOTTY; 50 51 if (IS_RDONLY(inode)) 52 return -EROFS; 53 54 if (!is_owner_or_cap(inode)) 55 return -EPERM; 56 57 if (get_user(flags, (int __user *)arg)) 58 return -EFAULT; 59 60 if (((flags ^ REISERFS_I(inode)-> 61 i_attrs) & (REISERFS_IMMUTABLE_FL | 62 REISERFS_APPEND_FL)) 63 && !capable(CAP_LINUX_IMMUTABLE)) 64 return -EPERM; 65 66 if ((flags & REISERFS_NOTAIL_FL) && 67 S_ISREG(inode->i_mode)) { 68 int result; 69 70 result = reiserfs_unpack(inode, filp); 71 if (result) 72 return result; 73 } 74 sd_attrs_to_i_attrs(flags, inode); 75 REISERFS_I(inode)->i_attrs = flags; 76 inode->i_ctime = CURRENT_TIME_SEC; 77 mark_inode_dirty(inode); 78 return 0; 79 } 80 case REISERFS_IOC_GETVERSION: 81 return put_user(inode->i_generation, (int __user *)arg); 82 case REISERFS_IOC_SETVERSION: 83 if (!is_owner_or_cap(inode)) 84 return -EPERM; 85 if (IS_RDONLY(inode)) 86 return -EROFS; 87 if (get_user(inode->i_generation, (int __user *)arg)) 88 return -EFAULT; 89 inode->i_ctime = CURRENT_TIME_SEC; 90 mark_inode_dirty(inode); 91 return 0; 92 default: 93 return -ENOTTY; 94 } 95 } 96 97 #ifdef CONFIG_COMPAT 98 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd, 99 unsigned long arg) 100 { 101 struct inode *inode = file->f_path.dentry->d_inode; 102 int ret; 103 104 /* These are just misnamed, they actually get/put from/to user an int */ 105 switch (cmd) { 106 case REISERFS_IOC32_UNPACK: 107 cmd = REISERFS_IOC_UNPACK; 108 break; 109 case REISERFS_IOC32_GETFLAGS: 110 cmd = REISERFS_IOC_GETFLAGS; 111 break; 112 case REISERFS_IOC32_SETFLAGS: 113 cmd = REISERFS_IOC_SETFLAGS; 114 break; 115 case REISERFS_IOC32_GETVERSION: 116 cmd = REISERFS_IOC_GETVERSION; 117 break; 118 case REISERFS_IOC32_SETVERSION: 119 cmd = REISERFS_IOC_SETVERSION; 120 break; 121 default: 122 return -ENOIOCTLCMD; 123 } 124 lock_kernel(); 125 ret = reiserfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg)); 126 unlock_kernel(); 127 return ret; 128 } 129 #endif 130 131 /* 132 ** reiserfs_unpack 133 ** Function try to convert tail from direct item into indirect. 134 ** It set up nopack attribute in the REISERFS_I(inode)->nopack 135 */ 136 static int reiserfs_unpack(struct inode *inode, struct file *filp) 137 { 138 int retval = 0; 139 int index; 140 struct page *page; 141 struct address_space *mapping; 142 unsigned long write_from; 143 unsigned long blocksize = inode->i_sb->s_blocksize; 144 145 if (inode->i_size == 0) { 146 REISERFS_I(inode)->i_flags |= i_nopack_mask; 147 return 0; 148 } 149 /* ioctl already done */ 150 if (REISERFS_I(inode)->i_flags & i_nopack_mask) { 151 return 0; 152 } 153 154 /* we need to make sure nobody is changing the file size beneath 155 ** us 156 */ 157 mutex_lock(&inode->i_mutex); 158 reiserfs_write_lock(inode->i_sb); 159 160 write_from = inode->i_size & (blocksize - 1); 161 /* if we are on a block boundary, we are already unpacked. */ 162 if (write_from == 0) { 163 REISERFS_I(inode)->i_flags |= i_nopack_mask; 164 goto out; 165 } 166 167 /* we unpack by finding the page with the tail, and calling 168 ** reiserfs_prepare_write on that page. This will force a 169 ** reiserfs_get_block to unpack the tail for us. 170 */ 171 index = inode->i_size >> PAGE_CACHE_SHIFT; 172 mapping = inode->i_mapping; 173 page = grab_cache_page(mapping, index); 174 retval = -ENOMEM; 175 if (!page) { 176 goto out; 177 } 178 retval = 179 mapping->a_ops->prepare_write(NULL, page, write_from, write_from); 180 if (retval) 181 goto out_unlock; 182 183 /* conversion can change page contents, must flush */ 184 flush_dcache_page(page); 185 retval = 186 mapping->a_ops->commit_write(NULL, page, write_from, write_from); 187 REISERFS_I(inode)->i_flags |= i_nopack_mask; 188 189 out_unlock: 190 unlock_page(page); 191 page_cache_release(page); 192 193 out: 194 mutex_unlock(&inode->i_mutex); 195 reiserfs_write_unlock(inode->i_sb); 196 return retval; 197 } 198