1 /* 2 * File operations for Coda. 3 * Original version: (C) 1996 Peter Braam 4 * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University 5 * 6 * Carnegie Mellon encourages users of this code to contribute improvements 7 * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>. 8 */ 9 10 #include <linux/types.h> 11 #include <linux/kernel.h> 12 #include <linux/time.h> 13 #include <linux/file.h> 14 #include <linux/fs.h> 15 #include <linux/stat.h> 16 #include <linux/errno.h> 17 #include <linux/smp_lock.h> 18 #include <linux/string.h> 19 #include <asm/uaccess.h> 20 21 #include <linux/coda.h> 22 #include <linux/coda_linux.h> 23 #include <linux/coda_fs_i.h> 24 #include <linux/coda_psdev.h> 25 26 #include "coda_int.h" 27 28 static ssize_t 29 coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos) 30 { 31 struct coda_file_info *cfi; 32 struct file *host_file; 33 34 cfi = CODA_FTOC(coda_file); 35 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 36 host_file = cfi->cfi_container; 37 38 if (!host_file->f_op || !host_file->f_op->read) 39 return -EINVAL; 40 41 return host_file->f_op->read(host_file, buf, count, ppos); 42 } 43 44 static ssize_t 45 coda_file_splice_read(struct file *coda_file, loff_t *ppos, 46 struct pipe_inode_info *pipe, size_t count, 47 unsigned int flags) 48 { 49 struct coda_file_info *cfi; 50 struct file *host_file; 51 52 cfi = CODA_FTOC(coda_file); 53 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 54 host_file = cfi->cfi_container; 55 56 if (!host_file->f_op || !host_file->f_op->splice_read) 57 return -EINVAL; 58 59 return host_file->f_op->splice_read(host_file, ppos, pipe, count,flags); 60 } 61 62 static ssize_t 63 coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos) 64 { 65 struct inode *host_inode, *coda_inode = coda_file->f_path.dentry->d_inode; 66 struct coda_file_info *cfi; 67 struct file *host_file; 68 ssize_t ret; 69 70 cfi = CODA_FTOC(coda_file); 71 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 72 host_file = cfi->cfi_container; 73 74 if (!host_file->f_op || !host_file->f_op->write) 75 return -EINVAL; 76 77 host_inode = host_file->f_path.dentry->d_inode; 78 mutex_lock(&coda_inode->i_mutex); 79 80 ret = host_file->f_op->write(host_file, buf, count, ppos); 81 82 coda_inode->i_size = host_inode->i_size; 83 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9; 84 coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC; 85 mutex_unlock(&coda_inode->i_mutex); 86 87 return ret; 88 } 89 90 static int 91 coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma) 92 { 93 struct coda_file_info *cfi; 94 struct coda_inode_info *cii; 95 struct file *host_file; 96 struct inode *coda_inode, *host_inode; 97 98 cfi = CODA_FTOC(coda_file); 99 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 100 host_file = cfi->cfi_container; 101 102 if (!host_file->f_op || !host_file->f_op->mmap) 103 return -ENODEV; 104 105 coda_inode = coda_file->f_path.dentry->d_inode; 106 host_inode = host_file->f_path.dentry->d_inode; 107 coda_file->f_mapping = host_file->f_mapping; 108 if (coda_inode->i_mapping == &coda_inode->i_data) 109 coda_inode->i_mapping = host_inode->i_mapping; 110 111 /* only allow additional mmaps as long as userspace isn't changing 112 * the container file on us! */ 113 else if (coda_inode->i_mapping != host_inode->i_mapping) 114 return -EBUSY; 115 116 /* keep track of how often the coda_inode/host_file has been mmapped */ 117 cii = ITOC(coda_inode); 118 cii->c_mapcount++; 119 cfi->cfi_mapcount++; 120 121 return host_file->f_op->mmap(host_file, vma); 122 } 123 124 int coda_open(struct inode *coda_inode, struct file *coda_file) 125 { 126 struct file *host_file = NULL; 127 int error; 128 unsigned short flags = coda_file->f_flags & (~O_EXCL); 129 unsigned short coda_flags = coda_flags_to_cflags(flags); 130 struct coda_file_info *cfi; 131 132 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL); 133 if (!cfi) 134 return -ENOMEM; 135 136 lock_kernel(); 137 138 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, 139 &host_file); 140 if (!host_file) 141 error = -EIO; 142 143 if (error) { 144 kfree(cfi); 145 unlock_kernel(); 146 return error; 147 } 148 149 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC); 150 151 cfi->cfi_magic = CODA_MAGIC; 152 cfi->cfi_mapcount = 0; 153 cfi->cfi_container = host_file; 154 155 BUG_ON(coda_file->private_data != NULL); 156 coda_file->private_data = cfi; 157 158 unlock_kernel(); 159 return 0; 160 } 161 162 int coda_release(struct inode *coda_inode, struct file *coda_file) 163 { 164 unsigned short flags = (coda_file->f_flags) & (~O_EXCL); 165 unsigned short coda_flags = coda_flags_to_cflags(flags); 166 struct coda_file_info *cfi; 167 struct coda_inode_info *cii; 168 struct inode *host_inode; 169 int err = 0; 170 171 lock_kernel(); 172 173 cfi = CODA_FTOC(coda_file); 174 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 175 176 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode), 177 coda_flags, coda_file->f_uid); 178 179 host_inode = cfi->cfi_container->f_path.dentry->d_inode; 180 cii = ITOC(coda_inode); 181 182 /* did we mmap this file? */ 183 if (coda_inode->i_mapping == &host_inode->i_data) { 184 cii->c_mapcount -= cfi->cfi_mapcount; 185 if (!cii->c_mapcount) 186 coda_inode->i_mapping = &coda_inode->i_data; 187 } 188 189 fput(cfi->cfi_container); 190 kfree(coda_file->private_data); 191 coda_file->private_data = NULL; 192 193 unlock_kernel(); 194 195 /* VFS fput ignores the return value from file_operations->release, so 196 * there is no use returning an error here */ 197 return 0; 198 } 199 200 int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync) 201 { 202 struct file *host_file; 203 struct dentry *host_dentry; 204 struct inode *host_inode, *coda_inode = coda_dentry->d_inode; 205 struct coda_file_info *cfi; 206 int err = 0; 207 208 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) || 209 S_ISLNK(coda_inode->i_mode))) 210 return -EINVAL; 211 212 cfi = CODA_FTOC(coda_file); 213 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 214 host_file = cfi->cfi_container; 215 216 if (host_file->f_op && host_file->f_op->fsync) { 217 host_dentry = host_file->f_path.dentry; 218 host_inode = host_dentry->d_inode; 219 mutex_lock(&host_inode->i_mutex); 220 err = host_file->f_op->fsync(host_file, host_dentry, datasync); 221 mutex_unlock(&host_inode->i_mutex); 222 } 223 224 if ( !err && !datasync ) { 225 lock_kernel(); 226 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode)); 227 unlock_kernel(); 228 } 229 230 return err; 231 } 232 233 const struct file_operations coda_file_operations = { 234 .llseek = generic_file_llseek, 235 .read = coda_file_read, 236 .write = coda_file_write, 237 .mmap = coda_file_mmap, 238 .open = coda_open, 239 .release = coda_release, 240 .fsync = coda_fsync, 241 .splice_read = coda_file_splice_read, 242 }; 243 244