arch/powerpc/platforms/cell/spufs/inode.c

   1 /*
   2  * SPU file system
   3  *
   4  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
   5  *
   6  * Author: Arnd Bergmann <arndb@de.ibm.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  */
  22
  23 #include <linux/file.h>
  24 #include <linux/fs.h>
  25 #include <linux/backing-dev.h>
  26 #include <linux/init.h>
  27 #include <linux/ioctl.h>
  28 #include <linux/module.h>
  29 #include <linux/mount.h>
  30 #include <linux/namei.h>
  31 #include <linux/pagemap.h>
  32 #include <linux/poll.h>
  33 #include <linux/slab.h>
  34 #include <linux/parser.h>
  35
  36 #include <asm/prom.h>
  37 #include <asm/semaphore.h>
  38 #include <asm/spu.h>
  39 #include <asm/spu_priv1.h>
  40 #include <asm/uaccess.h>
  41
  42 #include "spufs.h"
  43
  44 static struct kmem_cache *spufs_inode_cache;
  45 char *isolated_loader;
  46
  47 static struct inode *
  48 spufs_alloc_inode(struct super_block *sb)
  49 {
  50         struct spufs_inode_info *ei;
  51
  52         ei = kmem_cache_alloc(spufs_inode_cache, GFP_KERNEL);
  53         if (!ei)
  54                 return NULL;
  55
  56         ei->i_gang = NULL;
  57         ei->i_ctx = NULL;
  58         ei->i_openers = 0;
  59
  60         return &ei->vfs_inode;
  61 }
  62
  63 static void
  64 spufs_destroy_inode(struct inode *inode)
  65 {
  66         kmem_cache_free(spufs_inode_cache, SPUFS_I(inode));
  67 }
  68
  69 static void
  70 spufs_init_once(void *p, struct kmem_cache * cachep, unsigned long flags)
  71 {
  72         struct spufs_inode_info *ei = p;
  73
  74         inode_init_once(&ei->vfs_inode);
  75 }
  76
  77 static struct inode *
  78 spufs_new_inode(struct super_block *sb, int mode)
  79 {
  80         struct inode *inode;
  81
  82         inode = new_inode(sb);
  83         if (!inode)
  84                 goto out;
  85
  86         inode->i_mode = mode;
  87         inode->i_uid = current->fsuid;
  88         inode->i_gid = current->fsgid;
  89         inode->i_blocks = 0;
  90         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
  91 out:
  92         return inode;
  93 }
  94
  95 static int
  96 spufs_setattr(struct dentry *dentry, struct iattr *attr)
  97 {
  98         struct inode *inode = dentry->d_inode;
  99
 100         if ((attr->ia_valid & ATTR_SIZE) &&
 101             (attr->ia_size != inode->i_size))
 102                 return -EINVAL;
 103         return inode_setattr(inode, attr);
 104 }
 105
 106
 107 static int
 108 spufs_new_file(struct super_block *sb, struct dentry *dentry,
 109                 const struct file_operations *fops, int mode,
 110                 struct spu_context *ctx)
 111 {
 112         static struct inode_operations spufs_file_iops = {
 113                 .setattr = spufs_setattr,
 114         };
 115         struct inode *inode;
 116         int ret;
 117
 118         ret = -ENOSPC;
 119         inode = spufs_new_inode(sb, S_IFREG | mode);
 120         if (!inode)
 121                 goto out;
 122
 123         ret = 0;
 124         inode->i_op = &spufs_file_iops;
 125         inode->i_fop = fops;
 126         inode->i_private = SPUFS_I(inode)->i_ctx = get_spu_context(ctx);
 127         d_add(dentry, inode);
 128 out:
 129         return ret;
 130 }
 131
 132 static void
 133 spufs_delete_inode(struct inode *inode)
 134 {
 135         struct spufs_inode_info *ei = SPUFS_I(inode);
 136
 137         if (ei->i_ctx)
 138                 put_spu_context(ei->i_ctx);
 139         if (ei->i_gang)
 140                 put_spu_gang(ei->i_gang);
 141         clear_inode(inode);
 142 }
 143
 144 static void spufs_prune_dir(struct dentry *dir)
 145 {
 146         struct dentry *dentry, *tmp;
 147
 148         mutex_lock(&dir->d_inode->i_mutex);
 149         list_for_each_entry_safe(dentry, tmp, &dir->d_subdirs, d_u.d_child) {
 150                 spin_lock(&dcache_lock);
 151                 spin_lock(&dentry->d_lock);
 152                 if (!(d_unhashed(dentry)) && dentry->d_inode) {
 153                         dget_locked(dentry);
 154                         __d_drop(dentry);
 155                         spin_unlock(&dentry->d_lock);
 156                         simple_unlink(dir->d_inode, dentry);
 157                         spin_unlock(&dcache_lock);
 158                         dput(dentry);
 159                 } else {
 160                         spin_unlock(&dentry->d_lock);
 161                         spin_unlock(&dcache_lock);
 162                 }
 163         }
 164         shrink_dcache_parent(dir);
 165         mutex_unlock(&dir->d_inode->i_mutex);
 166 }
 167
 168 /* Caller must hold parent->i_mutex */
 169 static int spufs_rmdir(struct inode *parent, struct dentry *dir)
 170 {
 171         /* remove all entries */
 172         spufs_prune_dir(dir);
 173
 174         return simple_rmdir(parent, dir);
 175 }
 176
 177 static int spufs_fill_dir(struct dentry *dir, struct tree_descr *files,
 178                           int mode, struct spu_context *ctx)
 179 {
 180         struct dentry *dentry;
 181         int ret;
 182
 183         while (files->name && files->name[0]) {
 184                 ret = -ENOMEM;
 185                 dentry = d_alloc_name(dir, files->name);
 186                 if (!dentry)
 187                         goto out;
 188                 ret = spufs_new_file(dir->d_sb, dentry, files->ops,
 189                                         files->mode & mode, ctx);
 190                 if (ret)
 191                         goto out;
 192                 files++;
 193         }
 194         return 0;
 195 out:
 196         spufs_prune_dir(dir);
 197         return ret;
 198 }
 199
 200 static int spufs_dir_close(struct inode *inode, struct file *file)
 201 {
 202         struct spu_context *ctx;
 203         struct inode *parent;
 204         struct dentry *dir;
 205         int ret;
 206
 207         dir = file->f_path.dentry;
 208         parent = dir->d_parent->d_inode;
 209         ctx = SPUFS_I(dir->d_inode)->i_ctx;
 210
 211         mutex_lock(&parent->i_mutex);
 212         ret = spufs_rmdir(parent, dir);
 213         mutex_unlock(&parent->i_mutex);
 214         WARN_ON(ret);
 215
 216         /* We have to give up the mm_struct */
 217         spu_forget(ctx);
 218
 219         return dcache_dir_close(inode, file);
 220 }
 221
 222 const struct inode_operations spufs_dir_inode_operations = {
 223         .lookup = simple_lookup,
 224 };
 225
 226 const struct file_operations spufs_context_fops = {
 227         .open           = dcache_dir_open,
 228         .release        = spufs_dir_close,
 229         .llseek         = dcache_dir_lseek,
 230         .read           = generic_read_dir,
 231         .readdir        = dcache_readdir,
 232         .fsync          = simple_sync_file,
 233 };
 234 EXPORT_SYMBOL_GPL(spufs_context_fops);
 235
 236 static int
 237 spufs_mkdir(struct inode *dir, struct dentry *dentry, unsigned int flags,
 238                 int mode)
 239 {
 240         int ret;
 241         struct inode *inode;
 242         struct spu_context *ctx;
 243
 244         ret = -ENOSPC;
 245         inode = spufs_new_inode(dir->i_sb, mode | S_IFDIR);
 246         if (!inode)
 247                 goto out;
 248
 249         if (dir->i_mode & S_ISGID) {
 250                 inode->i_gid = dir->i_gid;
 251                 inode->i_mode &= S_ISGID;
 252         }
 253         ctx = alloc_spu_context(SPUFS_I(dir)->i_gang); /* XXX gang */
 254         SPUFS_I(inode)->i_ctx = ctx;
 255         if (!ctx)
 256                 goto out_iput;
 257
 258         ctx->flags = flags;
 259         inode->i_op = &spufs_dir_inode_operations;
 260         inode->i_fop = &simple_dir_operations;
 261         if (flags & SPU_CREATE_NOSCHED)
 262                 ret = spufs_fill_dir(dentry, spufs_dir_nosched_contents,
 263                                          mode, ctx);
 264         else
 265                 ret = spufs_fill_dir(dentry, spufs_dir_contents, mode, ctx);
 266
 267         if (ret)
 268                 goto out_free_ctx;
 269
 270         d_instantiate(dentry, inode);
 271         dget(dentry);
 272         dir->i_nlink++;
 273         dentry->d_inode->i_nlink++;
 274         goto out;
 275
 276 out_free_ctx:
 277         spu_forget(ctx);
 278         put_spu_context(ctx);
 279 out_iput:
 280         iput(inode);
 281 out:
 282         return ret;
 283 }
 284
 285 static int spufs_context_open(struct dentry *dentry, struct vfsmount *mnt)
 286 {
 287         int ret;
 288         struct file *filp;
 289
 290         ret = get_unused_fd();
 291         if (ret < 0) {
 292                 dput(dentry);
 293                 mntput(mnt);
 294                 goto out;
 295         }
 296
 297         filp = dentry_open(dentry, mnt, O_RDONLY);
 298         if (IS_ERR(filp)) {
 299                 put_unused_fd(ret);
 300                 ret = PTR_ERR(filp);
 301                 goto out;
 302         }
 303
 304         filp->f_op = &spufs_context_fops;
 305         fd_install(ret, filp);
 306 out:
 307         return ret;
 308 }
 309
 310 static int spufs_create_context(struct inode *inode,
 311                         struct dentry *dentry,
 312                         struct vfsmount *mnt, int flags, int mode)
 313 {
 314         int ret;
 315
 316         ret = -EPERM;
 317         if ((flags & SPU_CREATE_NOSCHED) &&
 318             !capable(CAP_SYS_NICE))
 319                 goto out_unlock;
 320
 321         ret = -EINVAL;
 322         if ((flags & (SPU_CREATE_NOSCHED | SPU_CREATE_ISOLATE))
 323             == SPU_CREATE_ISOLATE)
 324                 goto out_unlock;
 325
 326         ret = -ENODEV;
 327         if ((flags & SPU_CREATE_ISOLATE) && !isolated_loader)
 328                 goto out_unlock;
 329
 330         ret = spufs_mkdir(inode, dentry, flags, mode & S_IRWXUGO);
 331         if (ret)
 332                 goto out_unlock;
 333
 334         /*
 335          * get references for dget and mntget, will be released
 336          * in error path of *_open().
 337          */
 338         ret = spufs_context_open(dget(dentry), mntget(mnt));
 339         if (ret < 0) {
 340                 WARN_ON(spufs_rmdir(inode, dentry));
 341                 mutex_unlock(&inode->i_mutex);
 342                 spu_forget(SPUFS_I(dentry->d_inode)->i_ctx);
 343                 goto out;
 344         }
 345
 346 out_unlock:
 347         mutex_unlock(&inode->i_mutex);
 348 out:
 349         dput(dentry);
 350         return ret;
 351 }
 352
 353 static int
 354 spufs_mkgang(struct inode *dir, struct dentry *dentry, int mode)
 355 {
 356         int ret;
 357         struct inode *inode;
 358         struct spu_gang *gang;
 359
 360         ret = -ENOSPC;
 361         inode = spufs_new_inode(dir->i_sb, mode | S_IFDIR);
 362         if (!inode)
 363                 goto out;
 364
 365         ret = 0;
 366         if (dir->i_mode & S_ISGID) {
 367                 inode->i_gid = dir->i_gid;
 368                 inode->i_mode &= S_ISGID;
 369         }
 370         gang = alloc_spu_gang();
 371         SPUFS_I(inode)->i_ctx = NULL;
 372         SPUFS_I(inode)->i_gang = gang;
 373         if (!gang)
 374                 goto out_iput;
 375
 376         inode->i_op = &spufs_dir_inode_operations;
 377         inode->i_fop = &simple_dir_operations;
 378
 379         d_instantiate(dentry, inode);
 380         dir->i_nlink++;
 381         dentry->d_inode->i_nlink++;
 382         return ret;
 383
 384 out_iput:
 385         iput(inode);
 386 out:
 387         return ret;
 388 }
 389
 390 static int spufs_gang_open(struct dentry *dentry, struct vfsmount *mnt)
 391 {
 392         int ret;
 393         struct file *filp;
 394
 395         ret = get_unused_fd();
 396         if (ret < 0) {
 397                 dput(dentry);
 398                 mntput(mnt);
 399                 goto out;
 400         }
 401
 402         filp = dentry_open(dentry, mnt, O_RDONLY);
 403         if (IS_ERR(filp)) {
 404                 put_unused_fd(ret);
 405                 ret = PTR_ERR(filp);
 406                 goto out;
 407         }
 408
 409         filp->f_op = &simple_dir_operations;
 410         fd_install(ret, filp);
 411 out:
 412         return ret;
 413 }
 414
 415 static int spufs_create_gang(struct inode *inode,
 416                         struct dentry *dentry,
 417                         struct vfsmount *mnt, int mode)
 418 {
 419         int ret;
 420
 421         ret = spufs_mkgang(inode, dentry, mode & S_IRWXUGO);
 422         if (ret)
 423                 goto out;
 424
 425         /*
 426          * get references for dget and mntget, will be released
 427          * in error path of *_open().
 428          */
 429         ret = spufs_gang_open(dget(dentry), mntget(mnt));
 430         if (ret < 0) {
 431                 int err = simple_rmdir(inode, dentry);
 432                 WARN_ON(err);
 433         }
 434
 435 out:
 436         mutex_unlock(&inode->i_mutex);
 437         dput(dentry);
 438         return ret;
 439 }
 440
 441
 442 static struct file_system_type spufs_type;
 443
 444 long spufs_create(struct nameidata *nd, unsigned int flags, mode_t mode)
 445 {
 446         struct dentry *dentry;
 447         int ret;
 448
 449         ret = -EINVAL;
 450         /* check if we are on spufs */
 451         if (nd->dentry->d_sb->s_type != &spufs_type)
 452                 goto out;
 453
 454         /* don't accept undefined flags */
 455         if (flags & (~SPU_CREATE_FLAG_ALL))
 456                 goto out;
 457
 458         /* only threads can be underneath a gang */
 459         if (nd->dentry != nd->dentry->d_sb->s_root) {
 460                 if ((flags & SPU_CREATE_GANG) ||
 461                     !SPUFS_I(nd->dentry->d_inode)->i_gang)
 462                         goto out;
 463         }
 464
 465         dentry = lookup_create(nd, 1);
 466         ret = PTR_ERR(dentry);
 467         if (IS_ERR(dentry))
 468                 goto out_dir;
 469
 470         ret = -EEXIST;
 471         if (dentry->d_inode)
 472                 goto out_dput;
 473
 474         mode &= ~current->fs->umask;
 475
 476         if (flags & SPU_CREATE_GANG)
 477                 return spufs_create_gang(nd->dentry->d_inode,
 478                                         dentry, nd->mnt, mode);
 479         else
 480                 return spufs_create_context(nd->dentry->d_inode,
 481                                         dentry, nd->mnt, flags, mode);
 482
 483 out_dput:
 484         dput(dentry);
 485 out_dir:
 486         mutex_unlock(&nd->dentry->d_inode->i_mutex);
 487 out:
 488         return ret;
 489 }
 490
 491 /* File system initialization */
 492 enum {
 493         Opt_uid, Opt_gid, Opt_mode, Opt_err,
 494 };
 495
 496 static match_table_t spufs_tokens = {
 497         { Opt_uid,  "uid=%d" },
 498         { Opt_gid,  "gid=%d" },
 499         { Opt_mode, "mode=%o" },
 500         { Opt_err,   NULL  },
 501 };
 502
 503 static int
 504 spufs_parse_options(char *options, struct inode *root)
 505 {
 506         char *p;
 507         substring_t args[MAX_OPT_ARGS];
 508
 509         while ((p = strsep(&options, ",")) != NULL) {
 510                 int token, option;
 511
 512                 if (!*p)
 513                         continue;
 514
 515                 token = match_token(p, spufs_tokens, args);
 516                 switch (token) {
 517                 case Opt_uid:
 518                         if (match_int(&args[0], &option))
 519                                 return 0;
 520                         root->i_uid = option;
 521                         break;
 522                 case Opt_gid:
 523                         if (match_int(&args[0], &option))
 524                                 return 0;
 525                         root->i_gid = option;
 526                         break;
 527                 case Opt_mode:
 528                         if (match_octal(&args[0], &option))
 529                                 return 0;
 530                         root->i_mode = option | S_IFDIR;
 531                         break;
 532                 default:
 533                         return 0;
 534                 }
 535         }
 536         return 1;
 537 }
 538
 539 static void spufs_exit_isolated_loader(void)
 540 {
 541         kfree(isolated_loader);
 542 }
 543
 544 static void
 545 spufs_init_isolated_loader(void)
 546 {
 547         struct device_node *dn;
 548         const char *loader;
 549         int size;
 550
 551         dn = of_find_node_by_path("/spu-isolation");
 552         if (!dn)
 553                 return;
 554
 555         loader = of_get_property(dn, "loader", &size);
 556         if (!loader)
 557                 return;
 558
 559         /* kmalloc should align on a 16 byte boundary..* */
 560         isolated_loader = kmalloc(size, GFP_KERNEL);
 561         if (!isolated_loader)
 562                 return;
 563
 564         memcpy(isolated_loader, loader, size);
 565         printk(KERN_INFO "spufs: SPU isolation mode enabled\n");
 566 }
 567
 568 static int
 569 spufs_create_root(struct super_block *sb, void *data)
 570 {
 571         struct inode *inode;
 572         int ret;
 573
 574         ret = -ENODEV;
 575         if (!spu_management_ops)
 576                 goto out;
 577
 578         ret = -ENOMEM;
 579         inode = spufs_new_inode(sb, S_IFDIR | 0775);
 580         if (!inode)
 581                 goto out;
 582
 583         inode->i_op = &spufs_dir_inode_operations;
 584         inode->i_fop = &simple_dir_operations;
 585         SPUFS_I(inode)->i_ctx = NULL;
 586
 587         ret = -EINVAL;
 588         if (!spufs_parse_options(data, inode))
 589                 goto out_iput;
 590
 591         ret = -ENOMEM;
 592         sb->s_root = d_alloc_root(inode);
 593         if (!sb->s_root)
 594                 goto out_iput;
 595
 596         return 0;
 597 out_iput:
 598         iput(inode);
 599 out:
 600         return ret;
 601 }
 602
 603 static int
 604 spufs_fill_super(struct super_block *sb, void *data, int silent)
 605 {
 606         static struct super_operations s_ops = {
 607                 .alloc_inode = spufs_alloc_inode,
 608                 .destroy_inode = spufs_destroy_inode,
 609                 .statfs = simple_statfs,
 610                 .delete_inode = spufs_delete_inode,
 611                 .drop_inode = generic_delete_inode,
 612         };
 613
 614         sb->s_maxbytes = MAX_LFS_FILESIZE;
 615         sb->s_blocksize = PAGE_CACHE_SIZE;
 616         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 617         sb->s_magic = SPUFS_MAGIC;
 618         sb->s_op = &s_ops;
 619
 620         return spufs_create_root(sb, data);
 621 }
 622
 623 static int
 624 spufs_get_sb(struct file_system_type *fstype, int flags,
 625                 const char *name, void *data, struct vfsmount *mnt)
 626 {
 627         return get_sb_single(fstype, flags, data, spufs_fill_super, mnt);
 628 }
 629
 630 static struct file_system_type spufs_type = {
 631         .owner = THIS_MODULE,
 632         .name = "spufs",
 633         .get_sb = spufs_get_sb,
 634         .kill_sb = kill_litter_super,
 635 };
 636
 637 static int __init spufs_init(void)
 638 {
 639         int ret;
 640
 641         ret = -ENODEV;
 642         if (!spu_management_ops)
 643                 goto out;
 644
 645         ret = -ENOMEM;
 646         spufs_inode_cache = kmem_cache_create("spufs_inode_cache",
 647                         sizeof(struct spufs_inode_info), 0,
 648                         SLAB_HWCACHE_ALIGN, spufs_init_once, NULL);
 649
 650         if (!spufs_inode_cache)
 651                 goto out;
 652         ret = spu_sched_init();
 653         if (ret)
 654                 goto out_cache;
 655         ret = register_filesystem(&spufs_type);
 656         if (ret)
 657                 goto out_sched;
 658         ret = register_spu_syscalls(&spufs_calls);
 659         if (ret)
 660                 goto out_fs;
 661         ret = register_arch_coredump_calls(&spufs_coredump_calls);
 662         if (ret)
 663                 goto out_syscalls;
 664
 665         spufs_init_isolated_loader();
 666
 667         return 0;
 668
 669 out_syscalls:
 670         unregister_spu_syscalls(&spufs_calls);
 671 out_fs:
 672         unregister_filesystem(&spufs_type);
 673 out_sched:
 674         spu_sched_exit();
 675 out_cache:
 676         kmem_cache_destroy(spufs_inode_cache);
 677 out:
 678         return ret;
 679 }
 680 module_init(spufs_init);
 681
 682 static void __exit spufs_exit(void)
 683 {
 684         spu_sched_exit();
 685         spufs_exit_isolated_loader();
 686         unregister_arch_coredump_calls(&spufs_coredump_calls);
 687         unregister_spu_syscalls(&spufs_calls);
 688         unregister_filesystem(&spufs_type);
 689         kmem_cache_destroy(spufs_inode_cache);
 690 }
 691 module_exit(spufs_exit);
 692
 693 MODULE_LICENSE("GPL");
 694 MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
 695