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