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, *tmp;
 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         /*
 197          * remove all children from dir. dir->inode is not set so don't
 198          * just simply use spufs_prune_dir() and panic afterwards :)
 199          * dput() looks like it will do the right thing:
 200          * - dec parent's ref counter
 201          * - remove child from parent's child list
 202          * - free child's inode if possible
 203          * - free child
 204          */
 205         list_for_each_entry_safe(dentry, tmp, &dir->d_subdirs, d_u.d_child) {
 206                 dput(dentry);
 207         }
 208
 209         shrink_dcache_parent(dir);
 210         return ret;
 211 }
 212
 213 static int spufs_dir_close(struct inode *inode, struct file *file)
 214 {
 215         struct spu_context *ctx;
 216         struct inode *parent;
 217         struct dentry *dir;
 218         int ret;
 219
 220         dir = file->f_path.dentry;
 221         parent = dir->d_parent->d_inode;
 222         ctx = SPUFS_I(dir->d_inode)->i_ctx;
 223
 224         mutex_lock(&parent->i_mutex);
 225         ret = spufs_rmdir(parent, dir);
 226         mutex_unlock(&parent->i_mutex);
 227         WARN_ON(ret);
 228
 229         /* We have to give up the mm_struct */
 230         spu_forget(ctx);
 231
 232         return dcache_dir_close(inode, file);
 233 }
 234
 235 const struct inode_operations spufs_dir_inode_operations = {
 236         .lookup = simple_lookup,
 237 };
 238
 239 const struct file_operations spufs_context_fops = {
 240         .open           = dcache_dir_open,
 241         .release        = spufs_dir_close,
 242         .llseek         = dcache_dir_lseek,
 243         .read           = generic_read_dir,
 244         .readdir        = dcache_readdir,
 245         .fsync          = simple_sync_file,
 246 };
 247 EXPORT_SYMBOL_GPL(spufs_context_fops);
 248
 249 static int
 250 spufs_mkdir(struct inode *dir, struct dentry *dentry, unsigned int flags,
 251                 int mode)
 252 {
 253         int ret;
 254         struct inode *inode;
 255         struct spu_context *ctx;
 256
 257         ret = -ENOSPC;
 258         inode = spufs_new_inode(dir->i_sb, mode | S_IFDIR);
 259         if (!inode)
 260                 goto out;
 261
 262         if (dir->i_mode & S_ISGID) {
 263                 inode->i_gid = dir->i_gid;
 264                 inode->i_mode &= S_ISGID;
 265         }
 266         ctx = alloc_spu_context(SPUFS_I(dir)->i_gang); /* XXX gang */
 267         SPUFS_I(inode)->i_ctx = ctx;
 268         if (!ctx)
 269                 goto out_iput;
 270
 271         ctx->flags = flags;
 272         inode->i_op = &spufs_dir_inode_operations;
 273         inode->i_fop = &simple_dir_operations;
 274         if (flags & SPU_CREATE_NOSCHED)
 275                 ret = spufs_fill_dir(dentry, spufs_dir_nosched_contents,
 276                                          mode, ctx);
 277         else
 278                 ret = spufs_fill_dir(dentry, spufs_dir_contents, mode, ctx);
 279
 280         if (ret)
 281                 goto out_free_ctx;
 282
 283         d_instantiate(dentry, inode);
 284         dget(dentry);
 285         dir->i_nlink++;
 286         dentry->d_inode->i_nlink++;
 287         goto out;
 288
 289 out_free_ctx:
 290         spu_forget(ctx);
 291         put_spu_context(ctx);
 292 out_iput:
 293         iput(inode);
 294 out:
 295         return ret;
 296 }
 297
 298 static int spufs_context_open(struct dentry *dentry, struct vfsmount *mnt)
 299 {
 300         int ret;
 301         struct file *filp;
 302
 303         ret = get_unused_fd();
 304         if (ret < 0) {
 305                 dput(dentry);
 306                 mntput(mnt);
 307                 goto out;
 308         }
 309
 310         filp = dentry_open(dentry, mnt, O_RDONLY);
 311         if (IS_ERR(filp)) {
 312                 put_unused_fd(ret);
 313                 ret = PTR_ERR(filp);
 314                 goto out;
 315         }
 316
 317         filp->f_op = &spufs_context_fops;
 318         fd_install(ret, filp);
 319 out:
 320         return ret;
 321 }
 322
 323 static int spufs_create_context(struct inode *inode,
 324                         struct dentry *dentry,
 325                         struct vfsmount *mnt, int flags, int mode)
 326 {
 327         int ret;
 328
 329         ret = -EPERM;
 330         if ((flags & SPU_CREATE_NOSCHED) &&
 331             !capable(CAP_SYS_NICE))
 332                 goto out_unlock;
 333
 334         ret = -EINVAL;
 335         if ((flags & (SPU_CREATE_NOSCHED | SPU_CREATE_ISOLATE))
 336             == SPU_CREATE_ISOLATE)
 337                 goto out_unlock;
 338
 339         ret = -ENODEV;
 340         if ((flags & SPU_CREATE_ISOLATE) && !isolated_loader)
 341                 goto out_unlock;
 342
 343         ret = spufs_mkdir(inode, dentry, flags, mode & S_IRWXUGO);
 344         if (ret)
 345                 goto out_unlock;
 346
 347         /*
 348          * get references for dget and mntget, will be released
 349          * in error path of *_open().
 350          */
 351         ret = spufs_context_open(dget(dentry), mntget(mnt));
 352         if (ret < 0) {
 353                 WARN_ON(spufs_rmdir(inode, dentry));
 354                 mutex_unlock(&inode->i_mutex);
 355                 spu_forget(SPUFS_I(dentry->d_inode)->i_ctx);
 356                 goto out;
 357         }
 358
 359 out_unlock:
 360         mutex_unlock(&inode->i_mutex);
 361 out:
 362         dput(dentry);
 363         return ret;
 364 }
 365
 366 static int
 367 spufs_mkgang(struct inode *dir, struct dentry *dentry, int mode)
 368 {
 369         int ret;
 370         struct inode *inode;
 371         struct spu_gang *gang;
 372
 373         ret = -ENOSPC;
 374         inode = spufs_new_inode(dir->i_sb, mode | S_IFDIR);
 375         if (!inode)
 376                 goto out;
 377
 378         ret = 0;
 379         if (dir->i_mode & S_ISGID) {
 380                 inode->i_gid = dir->i_gid;
 381                 inode->i_mode &= S_ISGID;
 382         }
 383         gang = alloc_spu_gang();
 384         SPUFS_I(inode)->i_ctx = NULL;
 385         SPUFS_I(inode)->i_gang = gang;
 386         if (!gang)
 387                 goto out_iput;
 388
 389         inode->i_op = &spufs_dir_inode_operations;
 390         inode->i_fop = &simple_dir_operations;
 391
 392         d_instantiate(dentry, inode);
 393         dir->i_nlink++;
 394         dentry->d_inode->i_nlink++;
 395         return ret;
 396
 397 out_iput:
 398         iput(inode);
 399 out:
 400         return ret;
 401 }
 402
 403 static int spufs_gang_open(struct dentry *dentry, struct vfsmount *mnt)
 404 {
 405         int ret;
 406         struct file *filp;
 407
 408         ret = get_unused_fd();
 409         if (ret < 0) {
 410                 dput(dentry);
 411                 mntput(mnt);
 412                 goto out;
 413         }
 414
 415         filp = dentry_open(dentry, mnt, O_RDONLY);
 416         if (IS_ERR(filp)) {
 417                 put_unused_fd(ret);
 418                 ret = PTR_ERR(filp);
 419                 goto out;
 420         }
 421
 422         filp->f_op = &simple_dir_operations;
 423         fd_install(ret, filp);
 424 out:
 425         return ret;
 426 }
 427
 428 static int spufs_create_gang(struct inode *inode,
 429                         struct dentry *dentry,
 430                         struct vfsmount *mnt, int mode)
 431 {
 432         int ret;
 433
 434         ret = spufs_mkgang(inode, dentry, mode & S_IRWXUGO);
 435         if (ret)
 436                 goto out;
 437
 438         /*
 439          * get references for dget and mntget, will be released
 440          * in error path of *_open().
 441          */
 442         ret = spufs_gang_open(dget(dentry), mntget(mnt));
 443         if (ret < 0) {
 444                 int err = simple_rmdir(inode, dentry);
 445                 WARN_ON(err);
 446         }
 447
 448 out:
 449         mutex_unlock(&inode->i_mutex);
 450         dput(dentry);
 451         return ret;
 452 }
 453
 454
 455 static struct file_system_type spufs_type;
 456
 457 long spufs_create(struct nameidata *nd, unsigned int flags, mode_t mode)
 458 {
 459         struct dentry *dentry;
 460         int ret;
 461
 462         ret = -EINVAL;
 463         /* check if we are on spufs */
 464         if (nd->dentry->d_sb->s_type != &spufs_type)
 465                 goto out;
 466
 467         /* don't accept undefined flags */
 468         if (flags & (~SPU_CREATE_FLAG_ALL))
 469                 goto out;
 470
 471         /* only threads can be underneath a gang */
 472         if (nd->dentry != nd->dentry->d_sb->s_root) {
 473                 if ((flags & SPU_CREATE_GANG) ||
 474                     !SPUFS_I(nd->dentry->d_inode)->i_gang)
 475                         goto out;
 476         }
 477
 478         dentry = lookup_create(nd, 1);
 479         ret = PTR_ERR(dentry);
 480         if (IS_ERR(dentry))
 481                 goto out_dir;
 482
 483         ret = -EEXIST;
 484         if (dentry->d_inode)
 485                 goto out_dput;
 486
 487         mode &= ~current->fs->umask;
 488
 489         if (flags & SPU_CREATE_GANG)
 490                 return spufs_create_gang(nd->dentry->d_inode,
 491                                         dentry, nd->mnt, mode);
 492         else
 493                 return spufs_create_context(nd->dentry->d_inode,
 494                                         dentry, nd->mnt, flags, mode);
 495
 496 out_dput:
 497         dput(dentry);
 498 out_dir:
 499         mutex_unlock(&nd->dentry->d_inode->i_mutex);
 500 out:
 501         return ret;
 502 }
 503
 504 /* File system initialization */
 505 enum {
 506         Opt_uid, Opt_gid, Opt_mode, Opt_err,
 507 };
 508
 509 static match_table_t spufs_tokens = {
 510         { Opt_uid,  "uid=%d" },
 511         { Opt_gid,  "gid=%d" },
 512         { Opt_mode, "mode=%o" },
 513         { Opt_err,   NULL  },
 514 };
 515
 516 static int
 517 spufs_parse_options(char *options, struct inode *root)
 518 {
 519         char *p;
 520         substring_t args[MAX_OPT_ARGS];
 521
 522         while ((p = strsep(&options, ",")) != NULL) {
 523                 int token, option;
 524
 525                 if (!*p)
 526                         continue;
 527
 528                 token = match_token(p, spufs_tokens, args);
 529                 switch (token) {
 530                 case Opt_uid:
 531                         if (match_int(&args[0], &option))
 532                                 return 0;
 533                         root->i_uid = option;
 534                         break;
 535                 case Opt_gid:
 536                         if (match_int(&args[0], &option))
 537                                 return 0;
 538                         root->i_gid = option;
 539                         break;
 540                 case Opt_mode:
 541                         if (match_octal(&args[0], &option))
 542                                 return 0;
 543                         root->i_mode = option | S_IFDIR;
 544                         break;
 545                 default:
 546                         return 0;
 547                 }
 548         }
 549         return 1;
 550 }
 551
 552 static void spufs_exit_isolated_loader(void)
 553 {
 554         kfree(isolated_loader);
 555 }
 556
 557 static void
 558 spufs_init_isolated_loader(void)
 559 {
 560         struct device_node *dn;
 561         const char *loader;
 562         int size;
 563
 564         dn = of_find_node_by_path("/spu-isolation");
 565         if (!dn)
 566                 return;
 567
 568         loader = of_get_property(dn, "loader", &size);
 569         if (!loader)
 570                 return;
 571
 572         /* kmalloc should align on a 16 byte boundary..* */
 573         isolated_loader = kmalloc(size, GFP_KERNEL);
 574         if (!isolated_loader)
 575                 return;
 576
 577         memcpy(isolated_loader, loader, size);
 578         printk(KERN_INFO "spufs: SPU isolation mode enabled\n");
 579 }
 580
 581 static int
 582 spufs_create_root(struct super_block *sb, void *data)
 583 {
 584         struct inode *inode;
 585         int ret;
 586
 587         ret = -ENODEV;
 588         if (!spu_management_ops)
 589                 goto out;
 590
 591         ret = -ENOMEM;
 592         inode = spufs_new_inode(sb, S_IFDIR | 0775);
 593         if (!inode)
 594                 goto out;
 595
 596         inode->i_op = &spufs_dir_inode_operations;
 597         inode->i_fop = &simple_dir_operations;
 598         SPUFS_I(inode)->i_ctx = NULL;
 599
 600         ret = -EINVAL;
 601         if (!spufs_parse_options(data, inode))
 602                 goto out_iput;
 603
 604         ret = -ENOMEM;
 605         sb->s_root = d_alloc_root(inode);
 606         if (!sb->s_root)
 607                 goto out_iput;
 608
 609         return 0;
 610 out_iput:
 611         iput(inode);
 612 out:
 613         return ret;
 614 }
 615
 616 static int
 617 spufs_fill_super(struct super_block *sb, void *data, int silent)
 618 {
 619         static struct super_operations s_ops = {
 620                 .alloc_inode = spufs_alloc_inode,
 621                 .destroy_inode = spufs_destroy_inode,
 622                 .statfs = simple_statfs,
 623                 .delete_inode = spufs_delete_inode,
 624                 .drop_inode = generic_delete_inode,
 625         };
 626
 627         sb->s_maxbytes = MAX_LFS_FILESIZE;
 628         sb->s_blocksize = PAGE_CACHE_SIZE;
 629         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 630         sb->s_magic = SPUFS_MAGIC;
 631         sb->s_op = &s_ops;
 632
 633         return spufs_create_root(sb, data);
 634 }
 635
 636 static int
 637 spufs_get_sb(struct file_system_type *fstype, int flags,
 638                 const char *name, void *data, struct vfsmount *mnt)
 639 {
 640         return get_sb_single(fstype, flags, data, spufs_fill_super, mnt);
 641 }
 642
 643 static struct file_system_type spufs_type = {
 644         .owner = THIS_MODULE,
 645         .name = "spufs",
 646         .get_sb = spufs_get_sb,
 647         .kill_sb = kill_litter_super,
 648 };
 649
 650 static int __init spufs_init(void)
 651 {
 652         int ret;
 653
 654         ret = -ENODEV;
 655         if (!spu_management_ops)
 656                 goto out;
 657
 658         ret = -ENOMEM;
 659         spufs_inode_cache = kmem_cache_create("spufs_inode_cache",
 660                         sizeof(struct spufs_inode_info), 0,
 661                         SLAB_HWCACHE_ALIGN, spufs_init_once, NULL);
 662
 663         if (!spufs_inode_cache)
 664                 goto out;
 665         ret = spu_sched_init();
 666         if (ret)
 667                 goto out_cache;
 668         ret = register_filesystem(&spufs_type);
 669         if (ret)
 670                 goto out_sched;
 671         ret = register_spu_syscalls(&spufs_calls);
 672         if (ret)
 673                 goto out_fs;
 674         ret = register_arch_coredump_calls(&spufs_coredump_calls);
 675         if (ret)
 676                 goto out_syscalls;
 677
 678         spufs_init_isolated_loader();
 679
 680         return 0;
 681
 682 out_syscalls:
 683         unregister_spu_syscalls(&spufs_calls);
 684 out_fs:
 685         unregister_filesystem(&spufs_type);
 686 out_sched:
 687         spu_sched_exit();
 688 out_cache:
 689         kmem_cache_destroy(spufs_inode_cache);
 690 out:
 691         return ret;
 692 }
 693 module_init(spufs_init);
 694
 695 static void __exit spufs_exit(void)
 696 {
 697         spu_sched_exit();
 698         spufs_exit_isolated_loader();
 699         unregister_arch_coredump_calls(&spufs_coredump_calls);
 700         unregister_spu_syscalls(&spufs_calls);
 701         unregister_filesystem(&spufs_type);
 702         kmem_cache_destroy(spufs_inode_cache);
 703 }
 704 module_exit(spufs_exit);
 705
 706 MODULE_LICENSE("GPL");
 707 MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
 708