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 #include "coda_int.h" 28 29 /* if CODA_STORE fails with EOPNOTSUPP, venus clearly doesn't support 30 * CODA_STORE/CODA_RELEASE and we fall back on using the CODA_CLOSE upcall */ 31 static int use_coda_close; 32 33 static ssize_t 34 coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos) 35 { 36 struct coda_file_info *cfi; 37 struct file *host_file; 38 39 cfi = CODA_FTOC(coda_file); 40 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 41 host_file = cfi->cfi_container; 42 43 if (!host_file->f_op || !host_file->f_op->read) 44 return -EINVAL; 45 46 return host_file->f_op->read(host_file, buf, count, ppos); 47 } 48 49 static ssize_t 50 coda_file_sendfile(struct file *coda_file, loff_t *ppos, size_t count, 51 read_actor_t actor, void *target) 52 { 53 struct coda_file_info *cfi; 54 struct file *host_file; 55 56 cfi = CODA_FTOC(coda_file); 57 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 58 host_file = cfi->cfi_container; 59 60 if (!host_file->f_op || !host_file->f_op->sendfile) 61 return -EINVAL; 62 63 return host_file->f_op->sendfile(host_file, ppos, count, actor, target); 64 } 65 66 static ssize_t 67 coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos) 68 { 69 struct inode *host_inode, *coda_inode = coda_file->f_dentry->d_inode; 70 struct coda_file_info *cfi; 71 struct file *host_file; 72 ssize_t ret; 73 74 cfi = CODA_FTOC(coda_file); 75 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 76 host_file = cfi->cfi_container; 77 78 if (!host_file->f_op || !host_file->f_op->write) 79 return -EINVAL; 80 81 host_inode = host_file->f_dentry->d_inode; 82 mutex_lock(&coda_inode->i_mutex); 83 84 ret = host_file->f_op->write(host_file, buf, count, ppos); 85 86 coda_inode->i_size = host_inode->i_size; 87 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9; 88 coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC; 89 mutex_unlock(&coda_inode->i_mutex); 90 91 return ret; 92 } 93 94 static int 95 coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma) 96 { 97 struct coda_file_info *cfi; 98 struct coda_inode_info *cii; 99 struct file *host_file; 100 struct inode *coda_inode, *host_inode; 101 102 cfi = CODA_FTOC(coda_file); 103 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 104 host_file = cfi->cfi_container; 105 106 if (!host_file->f_op || !host_file->f_op->mmap) 107 return -ENODEV; 108 109 coda_inode = coda_file->f_dentry->d_inode; 110 host_inode = host_file->f_dentry->d_inode; 111 coda_file->f_mapping = host_file->f_mapping; 112 if (coda_inode->i_mapping == &coda_inode->i_data) 113 coda_inode->i_mapping = host_inode->i_mapping; 114 115 /* only allow additional mmaps as long as userspace isn't changing 116 * the container file on us! */ 117 else if (coda_inode->i_mapping != host_inode->i_mapping) 118 return -EBUSY; 119 120 /* keep track of how often the coda_inode/host_file has been mmapped */ 121 cii = ITOC(coda_inode); 122 cii->c_mapcount++; 123 cfi->cfi_mapcount++; 124 125 return host_file->f_op->mmap(host_file, vma); 126 } 127 128 int coda_open(struct inode *coda_inode, struct file *coda_file) 129 { 130 struct file *host_file = NULL; 131 int error; 132 unsigned short flags = coda_file->f_flags & (~O_EXCL); 133 unsigned short coda_flags = coda_flags_to_cflags(flags); 134 struct coda_file_info *cfi; 135 136 coda_vfs_stat.open++; 137 138 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL); 139 if (!cfi) { 140 unlock_kernel(); 141 return -ENOMEM; 142 } 143 144 lock_kernel(); 145 146 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, 147 &host_file); 148 if (error || !host_file) { 149 kfree(cfi); 150 unlock_kernel(); 151 return error; 152 } 153 154 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC); 155 156 cfi->cfi_magic = CODA_MAGIC; 157 cfi->cfi_mapcount = 0; 158 cfi->cfi_container = host_file; 159 160 BUG_ON(coda_file->private_data != NULL); 161 coda_file->private_data = cfi; 162 163 unlock_kernel(); 164 return 0; 165 } 166 167 int coda_flush(struct file *coda_file) 168 { 169 unsigned short flags = coda_file->f_flags & ~O_EXCL; 170 unsigned short coda_flags = coda_flags_to_cflags(flags); 171 struct coda_file_info *cfi; 172 struct inode *coda_inode; 173 int err = 0, fcnt; 174 175 lock_kernel(); 176 177 coda_vfs_stat.flush++; 178 179 /* last close semantics */ 180 fcnt = file_count(coda_file); 181 if (fcnt > 1) 182 goto out; 183 184 /* No need to make an upcall when we have not made any modifications 185 * to the file */ 186 if ((coda_file->f_flags & O_ACCMODE) == O_RDONLY) 187 goto out; 188 189 if (use_coda_close) 190 goto out; 191 192 cfi = CODA_FTOC(coda_file); 193 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 194 195 coda_inode = coda_file->f_dentry->d_inode; 196 197 err = venus_store(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, 198 coda_file->f_uid); 199 200 if (err == -EOPNOTSUPP) { 201 use_coda_close = 1; 202 err = 0; 203 } 204 205 out: 206 unlock_kernel(); 207 return err; 208 } 209 210 int coda_release(struct inode *coda_inode, struct file *coda_file) 211 { 212 unsigned short flags = (coda_file->f_flags) & (~O_EXCL); 213 unsigned short coda_flags = coda_flags_to_cflags(flags); 214 struct coda_file_info *cfi; 215 struct coda_inode_info *cii; 216 struct inode *host_inode; 217 int err = 0; 218 219 lock_kernel(); 220 coda_vfs_stat.release++; 221 222 if (!use_coda_close) { 223 err = venus_release(coda_inode->i_sb, coda_i2f(coda_inode), 224 coda_flags); 225 if (err == -EOPNOTSUPP) { 226 use_coda_close = 1; 227 err = 0; 228 } 229 } 230 231 cfi = CODA_FTOC(coda_file); 232 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 233 234 if (use_coda_close) 235 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode), 236 coda_flags, coda_file->f_uid); 237 238 host_inode = cfi->cfi_container->f_dentry->d_inode; 239 cii = ITOC(coda_inode); 240 241 /* did we mmap this file? */ 242 if (coda_inode->i_mapping == &host_inode->i_data) { 243 cii->c_mapcount -= cfi->cfi_mapcount; 244 if (!cii->c_mapcount) 245 coda_inode->i_mapping = &coda_inode->i_data; 246 } 247 248 fput(cfi->cfi_container); 249 kfree(coda_file->private_data); 250 coda_file->private_data = NULL; 251 252 unlock_kernel(); 253 return err; 254 } 255 256 int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync) 257 { 258 struct file *host_file; 259 struct dentry *host_dentry; 260 struct inode *host_inode, *coda_inode = coda_dentry->d_inode; 261 struct coda_file_info *cfi; 262 int err = 0; 263 264 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) || 265 S_ISLNK(coda_inode->i_mode))) 266 return -EINVAL; 267 268 cfi = CODA_FTOC(coda_file); 269 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); 270 host_file = cfi->cfi_container; 271 272 coda_vfs_stat.fsync++; 273 274 if (host_file->f_op && host_file->f_op->fsync) { 275 host_dentry = host_file->f_dentry; 276 host_inode = host_dentry->d_inode; 277 mutex_lock(&host_inode->i_mutex); 278 err = host_file->f_op->fsync(host_file, host_dentry, datasync); 279 mutex_unlock(&host_inode->i_mutex); 280 } 281 282 if ( !err && !datasync ) { 283 lock_kernel(); 284 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode)); 285 unlock_kernel(); 286 } 287 288 return err; 289 } 290 291 const struct file_operations coda_file_operations = { 292 .llseek = generic_file_llseek, 293 .read = coda_file_read, 294 .write = coda_file_write, 295 .mmap = coda_file_mmap, 296 .open = coda_open, 297 .flush = coda_flush, 298 .release = coda_release, 299 .fsync = coda_fsync, 300 .sendfile = coda_file_sendfile, 301 }; 302 303