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 #include <linux/coda_proc.h> 26 27 /* if CODA_STORE fails with EOPNOTSUPP, venus clearly doesn't support 28 * CODA_STORE/CODA_RELEASE and we fall back on using the CODA_CLOSE upcall */ 29 static int use_coda_close; 30 31 static ssize_t 32 coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos) 33 { 34 struct coda_file_info *cfi; 35 struct file *host_file; 36 37 cfi = CODA_FTOC(coda_file); 38 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 39 host_file = cfi->cfi_container; 40 41 if (!host_file->f_op || !host_file->f_op->read) 42 return -EINVAL; 43 44 return host_file->f_op->read(host_file, buf, count, ppos); 45 } 46 47 static ssize_t 48 coda_file_sendfile(struct file *coda_file, loff_t *ppos, size_t count, 49 read_actor_t actor, void *target) 50 { 51 struct coda_file_info *cfi; 52 struct file *host_file; 53 54 cfi = CODA_FTOC(coda_file); 55 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 56 host_file = cfi->cfi_container; 57 58 if (!host_file->f_op || !host_file->f_op->sendfile) 59 return -EINVAL; 60 61 return host_file->f_op->sendfile(host_file, ppos, count, actor, target); 62 } 63 64 static ssize_t 65 coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos) 66 { 67 struct inode *host_inode, *coda_inode = coda_file->f_dentry->d_inode; 68 struct coda_file_info *cfi; 69 struct file *host_file; 70 ssize_t ret; 71 72 cfi = CODA_FTOC(coda_file); 73 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 74 host_file = cfi->cfi_container; 75 76 if (!host_file->f_op || !host_file->f_op->write) 77 return -EINVAL; 78 79 host_inode = host_file->f_dentry->d_inode; 80 down(&coda_inode->i_sem); 81 82 ret = host_file->f_op->write(host_file, buf, count, ppos); 83 84 coda_inode->i_size = host_inode->i_size; 85 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9; 86 coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC; 87 up(&coda_inode->i_sem); 88 89 return ret; 90 } 91 92 static int 93 coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma) 94 { 95 struct coda_file_info *cfi; 96 struct coda_inode_info *cii; 97 struct file *host_file; 98 struct inode *coda_inode, *host_inode; 99 100 cfi = CODA_FTOC(coda_file); 101 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 102 host_file = cfi->cfi_container; 103 104 if (!host_file->f_op || !host_file->f_op->mmap) 105 return -ENODEV; 106 107 coda_inode = coda_file->f_dentry->d_inode; 108 host_inode = host_file->f_dentry->d_inode; 109 coda_file->f_mapping = host_file->f_mapping; 110 if (coda_inode->i_mapping == &coda_inode->i_data) 111 coda_inode->i_mapping = host_inode->i_mapping; 112 113 /* only allow additional mmaps as long as userspace isn't changing 114 * the container file on us! */ 115 else if (coda_inode->i_mapping != host_inode->i_mapping) 116 return -EBUSY; 117 118 /* keep track of how often the coda_inode/host_file has been mmapped */ 119 cii = ITOC(coda_inode); 120 cii->c_mapcount++; 121 cfi->cfi_mapcount++; 122 123 return host_file->f_op->mmap(host_file, vma); 124 } 125 126 int coda_open(struct inode *coda_inode, struct file *coda_file) 127 { 128 struct file *host_file = NULL; 129 int error; 130 unsigned short flags = coda_file->f_flags & (~O_EXCL); 131 unsigned short coda_flags = coda_flags_to_cflags(flags); 132 struct coda_file_info *cfi; 133 134 coda_vfs_stat.open++; 135 136 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL); 137 if (!cfi) { 138 unlock_kernel(); 139 return -ENOMEM; 140 } 141 142 lock_kernel(); 143 144 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, 145 &host_file); 146 if (error || !host_file) { 147 kfree(cfi); 148 unlock_kernel(); 149 return error; 150 } 151 152 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC); 153 154 cfi->cfi_magic = CODA_MAGIC; 155 cfi->cfi_mapcount = 0; 156 cfi->cfi_container = host_file; 157 158 BUG_ON(coda_file->private_data != NULL); 159 coda_file->private_data = cfi; 160 161 unlock_kernel(); 162 return 0; 163 } 164 165 int coda_flush(struct file *coda_file) 166 { 167 unsigned short flags = coda_file->f_flags & ~O_EXCL; 168 unsigned short coda_flags = coda_flags_to_cflags(flags); 169 struct coda_file_info *cfi; 170 struct inode *coda_inode; 171 int err = 0, fcnt; 172 173 lock_kernel(); 174 175 coda_vfs_stat.flush++; 176 177 /* last close semantics */ 178 fcnt = file_count(coda_file); 179 if (fcnt > 1) 180 goto out; 181 182 /* No need to make an upcall when we have not made any modifications 183 * to the file */ 184 if ((coda_file->f_flags & O_ACCMODE) == O_RDONLY) 185 goto out; 186 187 if (use_coda_close) 188 goto out; 189 190 cfi = CODA_FTOC(coda_file); 191 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 192 193 coda_inode = coda_file->f_dentry->d_inode; 194 195 err = venus_store(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, 196 coda_file->f_uid); 197 198 if (err == -EOPNOTSUPP) { 199 use_coda_close = 1; 200 err = 0; 201 } 202 203 out: 204 unlock_kernel(); 205 return err; 206 } 207 208 int coda_release(struct inode *coda_inode, struct file *coda_file) 209 { 210 unsigned short flags = (coda_file->f_flags) & (~O_EXCL); 211 unsigned short coda_flags = coda_flags_to_cflags(flags); 212 struct coda_file_info *cfi; 213 struct coda_inode_info *cii; 214 struct inode *host_inode; 215 int err = 0; 216 217 lock_kernel(); 218 coda_vfs_stat.release++; 219 220 if (!use_coda_close) { 221 err = venus_release(coda_inode->i_sb, coda_i2f(coda_inode), 222 coda_flags); 223 if (err == -EOPNOTSUPP) { 224 use_coda_close = 1; 225 err = 0; 226 } 227 } 228 229 cfi = CODA_FTOC(coda_file); 230 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 231 232 if (use_coda_close) 233 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode), 234 coda_flags, coda_file->f_uid); 235 236 host_inode = cfi->cfi_container->f_dentry->d_inode; 237 cii = ITOC(coda_inode); 238 239 /* did we mmap this file? */ 240 if (coda_inode->i_mapping == &host_inode->i_data) { 241 cii->c_mapcount -= cfi->cfi_mapcount; 242 if (!cii->c_mapcount) 243 coda_inode->i_mapping = &coda_inode->i_data; 244 } 245 246 fput(cfi->cfi_container); 247 kfree(coda_file->private_data); 248 coda_file->private_data = NULL; 249 250 unlock_kernel(); 251 return err; 252 } 253 254 int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync) 255 { 256 struct file *host_file; 257 struct dentry *host_dentry; 258 struct inode *host_inode, *coda_inode = coda_dentry->d_inode; 259 struct coda_file_info *cfi; 260 int err = 0; 261 262 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) || 263 S_ISLNK(coda_inode->i_mode))) 264 return -EINVAL; 265 266 cfi = CODA_FTOC(coda_file); 267 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 268 host_file = cfi->cfi_container; 269 270 coda_vfs_stat.fsync++; 271 272 if (host_file->f_op && host_file->f_op->fsync) { 273 host_dentry = host_file->f_dentry; 274 host_inode = host_dentry->d_inode; 275 down(&host_inode->i_sem); 276 err = host_file->f_op->fsync(host_file, host_dentry, datasync); 277 up(&host_inode->i_sem); 278 } 279 280 if ( !err && !datasync ) { 281 lock_kernel(); 282 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode)); 283 unlock_kernel(); 284 } 285 286 return err; 287 } 288 289 struct file_operations coda_file_operations = { 290 .llseek = generic_file_llseek, 291 .read = coda_file_read, 292 .write = coda_file_write, 293 .mmap = coda_file_mmap, 294 .open = coda_open, 295 .flush = coda_flush, 296 .release = coda_release, 297 .fsync = coda_fsync, 298 .sendfile = coda_file_sendfile, 299 }; 300 301