Michael Holzheu | 24bbb1f | 2006-06-23 02:05:06 -0700 | [diff] [blame] | 1 | /* |
Michael Holzheu | f19bfb2 | 2006-09-20 15:58:44 +0200 | [diff] [blame] | 2 | * arch/s390/hypfs/inode.c |
Michael Holzheu | 24bbb1f | 2006-06-23 02:05:06 -0700 | [diff] [blame] | 3 | * Hypervisor filesystem for Linux on s390. |
| 4 | * |
| 5 | * Copyright (C) IBM Corp. 2006 |
| 6 | * Author(s): Michael Holzheu <holzheu@de.ibm.com> |
| 7 | */ |
| 8 | |
| 9 | #include <linux/types.h> |
| 10 | #include <linux/errno.h> |
| 11 | #include <linux/fs.h> |
| 12 | #include <linux/namei.h> |
| 13 | #include <linux/vfs.h> |
| 14 | #include <linux/pagemap.h> |
| 15 | #include <linux/gfp.h> |
| 16 | #include <linux/time.h> |
| 17 | #include <linux/parser.h> |
| 18 | #include <linux/sysfs.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <asm/ebcdic.h> |
| 21 | #include "hypfs.h" |
| 22 | #include "hypfs_diag.h" |
| 23 | |
| 24 | #define HYPFS_MAGIC 0x687970 /* ASCII 'hyp' */ |
| 25 | #define TMP_SIZE 64 /* size of temporary buffers */ |
| 26 | |
| 27 | static struct dentry *hypfs_create_update_file(struct super_block *sb, |
| 28 | struct dentry *dir); |
| 29 | |
| 30 | struct hypfs_sb_info { |
| 31 | uid_t uid; /* uid used for files and dirs */ |
| 32 | gid_t gid; /* gid used for files and dirs */ |
| 33 | struct dentry *update_file; /* file to trigger update */ |
| 34 | time_t last_update; /* last update time in secs since 1970 */ |
| 35 | struct mutex lock; /* lock to protect update process */ |
| 36 | }; |
| 37 | |
| 38 | static struct file_operations hypfs_file_ops; |
| 39 | static struct file_system_type hypfs_type; |
| 40 | static struct super_operations hypfs_s_ops; |
| 41 | |
| 42 | /* start of list of all dentries, which have to be deleted on update */ |
| 43 | static struct dentry *hypfs_last_dentry; |
| 44 | |
| 45 | static void hypfs_update_update(struct super_block *sb) |
| 46 | { |
| 47 | struct hypfs_sb_info *sb_info = sb->s_fs_info; |
| 48 | struct inode *inode = sb_info->update_file->d_inode; |
| 49 | |
| 50 | sb_info->last_update = get_seconds(); |
| 51 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| 52 | } |
| 53 | |
| 54 | /* directory tree removal functions */ |
| 55 | |
| 56 | static void hypfs_add_dentry(struct dentry *dentry) |
| 57 | { |
| 58 | dentry->d_fsdata = hypfs_last_dentry; |
| 59 | hypfs_last_dentry = dentry; |
| 60 | } |
| 61 | |
| 62 | static void hypfs_remove(struct dentry *dentry) |
| 63 | { |
| 64 | struct dentry *parent; |
| 65 | |
| 66 | parent = dentry->d_parent; |
| 67 | if (S_ISDIR(dentry->d_inode->i_mode)) |
| 68 | simple_rmdir(parent->d_inode, dentry); |
| 69 | else |
| 70 | simple_unlink(parent->d_inode, dentry); |
| 71 | d_delete(dentry); |
| 72 | dput(dentry); |
| 73 | } |
| 74 | |
| 75 | static void hypfs_delete_tree(struct dentry *root) |
| 76 | { |
| 77 | while (hypfs_last_dentry) { |
| 78 | struct dentry *next_dentry; |
| 79 | next_dentry = hypfs_last_dentry->d_fsdata; |
| 80 | hypfs_remove(hypfs_last_dentry); |
| 81 | hypfs_last_dentry = next_dentry; |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | static struct inode *hypfs_make_inode(struct super_block *sb, int mode) |
| 86 | { |
| 87 | struct inode *ret = new_inode(sb); |
| 88 | |
| 89 | if (ret) { |
| 90 | struct hypfs_sb_info *hypfs_info = sb->s_fs_info; |
| 91 | ret->i_mode = mode; |
| 92 | ret->i_uid = hypfs_info->uid; |
| 93 | ret->i_gid = hypfs_info->gid; |
Michael Holzheu | 24bbb1f | 2006-06-23 02:05:06 -0700 | [diff] [blame] | 94 | ret->i_blocks = 0; |
| 95 | ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME; |
| 96 | if (mode & S_IFDIR) |
| 97 | ret->i_nlink = 2; |
| 98 | else |
| 99 | ret->i_nlink = 1; |
| 100 | } |
| 101 | return ret; |
| 102 | } |
| 103 | |
| 104 | static void hypfs_drop_inode(struct inode *inode) |
| 105 | { |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 106 | kfree(inode->i_private); |
Michael Holzheu | 24bbb1f | 2006-06-23 02:05:06 -0700 | [diff] [blame] | 107 | generic_delete_inode(inode); |
| 108 | } |
| 109 | |
| 110 | static int hypfs_open(struct inode *inode, struct file *filp) |
| 111 | { |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 112 | char *data = filp->f_dentry->d_inode->i_private; |
Michael Holzheu | 24bbb1f | 2006-06-23 02:05:06 -0700 | [diff] [blame] | 113 | struct hypfs_sb_info *fs_info; |
| 114 | |
| 115 | if (filp->f_mode & FMODE_WRITE) { |
| 116 | if (!(inode->i_mode & S_IWUGO)) |
| 117 | return -EACCES; |
| 118 | } |
| 119 | if (filp->f_mode & FMODE_READ) { |
| 120 | if (!(inode->i_mode & S_IRUGO)) |
| 121 | return -EACCES; |
| 122 | } |
| 123 | |
| 124 | fs_info = inode->i_sb->s_fs_info; |
| 125 | if(data) { |
| 126 | mutex_lock(&fs_info->lock); |
| 127 | filp->private_data = kstrdup(data, GFP_KERNEL); |
| 128 | if (!filp->private_data) { |
| 129 | mutex_unlock(&fs_info->lock); |
| 130 | return -ENOMEM; |
| 131 | } |
| 132 | mutex_unlock(&fs_info->lock); |
| 133 | } |
| 134 | return 0; |
| 135 | } |
| 136 | |
Badari Pulavarty | 027445c | 2006-09-30 23:28:46 -0700 | [diff] [blame] | 137 | static ssize_t hypfs_aio_read(struct kiocb *iocb, const struct iovec *iov, |
| 138 | unsigned long nr_segs, loff_t offset) |
Michael Holzheu | 24bbb1f | 2006-06-23 02:05:06 -0700 | [diff] [blame] | 139 | { |
| 140 | char *data; |
| 141 | size_t len; |
| 142 | struct file *filp = iocb->ki_filp; |
Badari Pulavarty | 027445c | 2006-09-30 23:28:46 -0700 | [diff] [blame] | 143 | /* XXX: temporary */ |
| 144 | char __user *buf = iov[0].iov_base; |
| 145 | size_t count = iov[0].iov_len; |
| 146 | |
| 147 | if (nr_segs != 1) { |
| 148 | count = -EINVAL; |
| 149 | goto out; |
| 150 | } |
Michael Holzheu | 24bbb1f | 2006-06-23 02:05:06 -0700 | [diff] [blame] | 151 | |
| 152 | data = filp->private_data; |
| 153 | len = strlen(data); |
| 154 | if (offset > len) { |
| 155 | count = 0; |
| 156 | goto out; |
| 157 | } |
| 158 | if (count > len - offset) |
| 159 | count = len - offset; |
| 160 | if (copy_to_user(buf, data + offset, count)) { |
| 161 | count = -EFAULT; |
| 162 | goto out; |
| 163 | } |
| 164 | iocb->ki_pos += count; |
| 165 | file_accessed(filp); |
| 166 | out: |
| 167 | return count; |
| 168 | } |
Badari Pulavarty | 027445c | 2006-09-30 23:28:46 -0700 | [diff] [blame] | 169 | static ssize_t hypfs_aio_write(struct kiocb *iocb, const struct iovec *iov, |
| 170 | unsigned long nr_segs, loff_t offset) |
Michael Holzheu | 24bbb1f | 2006-06-23 02:05:06 -0700 | [diff] [blame] | 171 | { |
| 172 | int rc; |
| 173 | struct super_block *sb; |
| 174 | struct hypfs_sb_info *fs_info; |
Badari Pulavarty | 027445c | 2006-09-30 23:28:46 -0700 | [diff] [blame] | 175 | size_t count = iov_length(iov, nr_segs); |
Michael Holzheu | 24bbb1f | 2006-06-23 02:05:06 -0700 | [diff] [blame] | 176 | |
| 177 | sb = iocb->ki_filp->f_dentry->d_inode->i_sb; |
| 178 | fs_info = sb->s_fs_info; |
| 179 | /* |
| 180 | * Currently we only allow one update per second for two reasons: |
| 181 | * 1. diag 204 is VERY expensive |
| 182 | * 2. If several processes do updates in parallel and then read the |
| 183 | * hypfs data, the likelihood of collisions is reduced, if we restrict |
| 184 | * the minimum update interval. A collision occurs, if during the |
| 185 | * data gathering of one process another process triggers an update |
| 186 | * If the first process wants to ensure consistent data, it has |
| 187 | * to restart data collection in this case. |
| 188 | */ |
| 189 | mutex_lock(&fs_info->lock); |
| 190 | if (fs_info->last_update == get_seconds()) { |
| 191 | rc = -EBUSY; |
| 192 | goto out; |
| 193 | } |
| 194 | hypfs_delete_tree(sb->s_root); |
| 195 | rc = hypfs_diag_create_files(sb, sb->s_root); |
| 196 | if (rc) { |
| 197 | printk(KERN_ERR "hypfs: Update failed\n"); |
| 198 | hypfs_delete_tree(sb->s_root); |
| 199 | goto out; |
| 200 | } |
| 201 | hypfs_update_update(sb); |
| 202 | rc = count; |
| 203 | out: |
| 204 | mutex_unlock(&fs_info->lock); |
| 205 | return rc; |
| 206 | } |
| 207 | |
| 208 | static int hypfs_release(struct inode *inode, struct file *filp) |
| 209 | { |
| 210 | kfree(filp->private_data); |
| 211 | return 0; |
| 212 | } |
| 213 | |
| 214 | enum { opt_uid, opt_gid, opt_err }; |
| 215 | |
| 216 | static match_table_t hypfs_tokens = { |
| 217 | {opt_uid, "uid=%u"}, |
| 218 | {opt_gid, "gid=%u"}, |
| 219 | {opt_err, NULL} |
| 220 | }; |
| 221 | |
| 222 | static int hypfs_parse_options(char *options, struct super_block *sb) |
| 223 | { |
| 224 | char *str; |
| 225 | substring_t args[MAX_OPT_ARGS]; |
| 226 | |
| 227 | if (!options) |
| 228 | return 0; |
| 229 | while ((str = strsep(&options, ",")) != NULL) { |
| 230 | int token, option; |
| 231 | struct hypfs_sb_info *hypfs_info = sb->s_fs_info; |
| 232 | |
| 233 | if (!*str) |
| 234 | continue; |
| 235 | token = match_token(str, hypfs_tokens, args); |
| 236 | switch (token) { |
| 237 | case opt_uid: |
| 238 | if (match_int(&args[0], &option)) |
| 239 | return -EINVAL; |
| 240 | hypfs_info->uid = option; |
| 241 | break; |
| 242 | case opt_gid: |
| 243 | if (match_int(&args[0], &option)) |
| 244 | return -EINVAL; |
| 245 | hypfs_info->gid = option; |
| 246 | break; |
| 247 | case opt_err: |
| 248 | default: |
| 249 | printk(KERN_ERR "hypfs: Unrecognized mount option " |
| 250 | "\"%s\" or missing value\n", str); |
| 251 | return -EINVAL; |
| 252 | } |
| 253 | } |
| 254 | return 0; |
| 255 | } |
| 256 | |
| 257 | static int hypfs_fill_super(struct super_block *sb, void *data, int silent) |
| 258 | { |
| 259 | struct inode *root_inode; |
| 260 | struct dentry *root_dentry; |
| 261 | int rc = 0; |
| 262 | struct hypfs_sb_info *sbi; |
| 263 | |
| 264 | sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL); |
| 265 | if (!sbi) |
| 266 | return -ENOMEM; |
| 267 | mutex_init(&sbi->lock); |
| 268 | sbi->uid = current->uid; |
| 269 | sbi->gid = current->gid; |
| 270 | sb->s_fs_info = sbi; |
| 271 | sb->s_blocksize = PAGE_CACHE_SIZE; |
| 272 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
| 273 | sb->s_magic = HYPFS_MAGIC; |
| 274 | sb->s_op = &hypfs_s_ops; |
| 275 | if (hypfs_parse_options(data, sb)) { |
| 276 | rc = -EINVAL; |
| 277 | goto err_alloc; |
| 278 | } |
| 279 | root_inode = hypfs_make_inode(sb, S_IFDIR | 0755); |
| 280 | if (!root_inode) { |
| 281 | rc = -ENOMEM; |
| 282 | goto err_alloc; |
| 283 | } |
| 284 | root_inode->i_op = &simple_dir_inode_operations; |
| 285 | root_inode->i_fop = &simple_dir_operations; |
| 286 | root_dentry = d_alloc_root(root_inode); |
| 287 | if (!root_dentry) { |
| 288 | iput(root_inode); |
| 289 | rc = -ENOMEM; |
| 290 | goto err_alloc; |
| 291 | } |
| 292 | rc = hypfs_diag_create_files(sb, root_dentry); |
| 293 | if (rc) |
| 294 | goto err_tree; |
| 295 | sbi->update_file = hypfs_create_update_file(sb, root_dentry); |
| 296 | if (IS_ERR(sbi->update_file)) { |
| 297 | rc = PTR_ERR(sbi->update_file); |
| 298 | goto err_tree; |
| 299 | } |
| 300 | hypfs_update_update(sb); |
| 301 | sb->s_root = root_dentry; |
| 302 | return 0; |
| 303 | |
| 304 | err_tree: |
| 305 | hypfs_delete_tree(root_dentry); |
| 306 | d_genocide(root_dentry); |
| 307 | dput(root_dentry); |
| 308 | err_alloc: |
| 309 | kfree(sbi); |
| 310 | return rc; |
| 311 | } |
| 312 | |
Andrew Morton | a5cf4b9 | 2006-06-23 04:01:35 -0700 | [diff] [blame] | 313 | static int hypfs_get_super(struct file_system_type *fst, int flags, |
| 314 | const char *devname, void *data, struct vfsmount *mnt) |
Michael Holzheu | 24bbb1f | 2006-06-23 02:05:06 -0700 | [diff] [blame] | 315 | { |
Andrew Morton | a5cf4b9 | 2006-06-23 04:01:35 -0700 | [diff] [blame] | 316 | return get_sb_single(fst, flags, data, hypfs_fill_super, mnt); |
Michael Holzheu | 24bbb1f | 2006-06-23 02:05:06 -0700 | [diff] [blame] | 317 | } |
| 318 | |
| 319 | static void hypfs_kill_super(struct super_block *sb) |
| 320 | { |
| 321 | struct hypfs_sb_info *sb_info = sb->s_fs_info; |
| 322 | |
Michael Holzheu | 388c571 | 2006-09-20 16:00:04 +0200 | [diff] [blame] | 323 | if (sb->s_root) { |
| 324 | hypfs_delete_tree(sb->s_root); |
| 325 | hypfs_remove(sb_info->update_file); |
| 326 | kfree(sb->s_fs_info); |
| 327 | sb->s_fs_info = NULL; |
| 328 | } |
Michael Holzheu | 24bbb1f | 2006-06-23 02:05:06 -0700 | [diff] [blame] | 329 | kill_litter_super(sb); |
| 330 | } |
| 331 | |
| 332 | static struct dentry *hypfs_create_file(struct super_block *sb, |
| 333 | struct dentry *parent, const char *name, |
| 334 | char *data, mode_t mode) |
| 335 | { |
| 336 | struct dentry *dentry; |
| 337 | struct inode *inode; |
| 338 | struct qstr qname; |
| 339 | |
| 340 | qname.name = name; |
| 341 | qname.len = strlen(name); |
| 342 | qname.hash = full_name_hash(name, qname.len); |
| 343 | dentry = lookup_one_len(name, parent, strlen(name)); |
| 344 | if (IS_ERR(dentry)) |
| 345 | return ERR_PTR(-ENOMEM); |
| 346 | inode = hypfs_make_inode(sb, mode); |
| 347 | if (!inode) { |
| 348 | dput(dentry); |
| 349 | return ERR_PTR(-ENOMEM); |
| 350 | } |
| 351 | if (mode & S_IFREG) { |
| 352 | inode->i_fop = &hypfs_file_ops; |
| 353 | if (data) |
| 354 | inode->i_size = strlen(data); |
| 355 | else |
| 356 | inode->i_size = 0; |
| 357 | } else if (mode & S_IFDIR) { |
| 358 | inode->i_op = &simple_dir_inode_operations; |
| 359 | inode->i_fop = &simple_dir_operations; |
| 360 | parent->d_inode->i_nlink++; |
| 361 | } else |
| 362 | BUG(); |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 363 | inode->i_private = data; |
Michael Holzheu | 24bbb1f | 2006-06-23 02:05:06 -0700 | [diff] [blame] | 364 | d_instantiate(dentry, inode); |
| 365 | dget(dentry); |
| 366 | return dentry; |
| 367 | } |
| 368 | |
| 369 | struct dentry *hypfs_mkdir(struct super_block *sb, struct dentry *parent, |
| 370 | const char *name) |
| 371 | { |
| 372 | struct dentry *dentry; |
| 373 | |
| 374 | dentry = hypfs_create_file(sb, parent, name, NULL, S_IFDIR | DIR_MODE); |
| 375 | if (IS_ERR(dentry)) |
| 376 | return dentry; |
| 377 | hypfs_add_dentry(dentry); |
| 378 | parent->d_inode->i_nlink++; |
| 379 | return dentry; |
| 380 | } |
| 381 | |
| 382 | static struct dentry *hypfs_create_update_file(struct super_block *sb, |
| 383 | struct dentry *dir) |
| 384 | { |
| 385 | struct dentry *dentry; |
| 386 | |
| 387 | dentry = hypfs_create_file(sb, dir, "update", NULL, |
| 388 | S_IFREG | UPDATE_FILE_MODE); |
| 389 | /* |
| 390 | * We do not put the update file on the 'delete' list with |
| 391 | * hypfs_add_dentry(), since it should not be removed when the tree |
| 392 | * is updated. |
| 393 | */ |
| 394 | return dentry; |
| 395 | } |
| 396 | |
| 397 | struct dentry *hypfs_create_u64(struct super_block *sb, struct dentry *dir, |
| 398 | const char *name, __u64 value) |
| 399 | { |
| 400 | char *buffer; |
| 401 | char tmp[TMP_SIZE]; |
| 402 | struct dentry *dentry; |
| 403 | |
| 404 | snprintf(tmp, TMP_SIZE, "%lld\n", (unsigned long long int)value); |
| 405 | buffer = kstrdup(tmp, GFP_KERNEL); |
| 406 | if (!buffer) |
| 407 | return ERR_PTR(-ENOMEM); |
| 408 | dentry = |
| 409 | hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE); |
| 410 | if (IS_ERR(dentry)) { |
| 411 | kfree(buffer); |
| 412 | return ERR_PTR(-ENOMEM); |
| 413 | } |
| 414 | hypfs_add_dentry(dentry); |
| 415 | return dentry; |
| 416 | } |
| 417 | |
| 418 | struct dentry *hypfs_create_str(struct super_block *sb, struct dentry *dir, |
| 419 | const char *name, char *string) |
| 420 | { |
| 421 | char *buffer; |
| 422 | struct dentry *dentry; |
| 423 | |
| 424 | buffer = kmalloc(strlen(string) + 2, GFP_KERNEL); |
| 425 | if (!buffer) |
| 426 | return ERR_PTR(-ENOMEM); |
| 427 | sprintf(buffer, "%s\n", string); |
| 428 | dentry = |
| 429 | hypfs_create_file(sb, dir, name, buffer, S_IFREG | REG_FILE_MODE); |
| 430 | if (IS_ERR(dentry)) { |
| 431 | kfree(buffer); |
| 432 | return ERR_PTR(-ENOMEM); |
| 433 | } |
| 434 | hypfs_add_dentry(dentry); |
| 435 | return dentry; |
| 436 | } |
| 437 | |
| 438 | static struct file_operations hypfs_file_ops = { |
| 439 | .open = hypfs_open, |
| 440 | .release = hypfs_release, |
| 441 | .read = do_sync_read, |
| 442 | .write = do_sync_write, |
| 443 | .aio_read = hypfs_aio_read, |
| 444 | .aio_write = hypfs_aio_write, |
| 445 | }; |
| 446 | |
| 447 | static struct file_system_type hypfs_type = { |
| 448 | .owner = THIS_MODULE, |
| 449 | .name = "s390_hypfs", |
| 450 | .get_sb = hypfs_get_super, |
| 451 | .kill_sb = hypfs_kill_super |
| 452 | }; |
| 453 | |
| 454 | static struct super_operations hypfs_s_ops = { |
| 455 | .statfs = simple_statfs, |
| 456 | .drop_inode = hypfs_drop_inode, |
| 457 | }; |
| 458 | |
| 459 | static decl_subsys(s390, NULL, NULL); |
| 460 | |
| 461 | static int __init hypfs_init(void) |
| 462 | { |
| 463 | int rc; |
| 464 | |
| 465 | if (MACHINE_IS_VM) |
| 466 | return -ENODATA; |
| 467 | if (hypfs_diag_init()) { |
| 468 | rc = -ENODATA; |
| 469 | goto fail_diag; |
| 470 | } |
| 471 | kset_set_kset_s(&s390_subsys, hypervisor_subsys); |
| 472 | rc = subsystem_register(&s390_subsys); |
| 473 | if (rc) |
| 474 | goto fail_sysfs; |
| 475 | rc = register_filesystem(&hypfs_type); |
| 476 | if (rc) |
| 477 | goto fail_filesystem; |
| 478 | return 0; |
| 479 | |
| 480 | fail_filesystem: |
| 481 | subsystem_unregister(&s390_subsys); |
| 482 | fail_sysfs: |
| 483 | hypfs_diag_exit(); |
| 484 | fail_diag: |
| 485 | printk(KERN_ERR "hypfs: Initialization failed with rc = %i.\n", rc); |
| 486 | return rc; |
| 487 | } |
| 488 | |
| 489 | static void __exit hypfs_exit(void) |
| 490 | { |
| 491 | hypfs_diag_exit(); |
| 492 | unregister_filesystem(&hypfs_type); |
| 493 | subsystem_unregister(&s390_subsys); |
| 494 | } |
| 495 | |
| 496 | module_init(hypfs_init) |
| 497 | module_exit(hypfs_exit) |
| 498 | |
| 499 | MODULE_LICENSE("GPL"); |
| 500 | MODULE_AUTHOR("Michael Holzheu <holzheu@de.ibm.com>"); |
| 501 | MODULE_DESCRIPTION("s390 Hypervisor Filesystem"); |