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/uaccess.h>
  40
  41 #include "spufs.h"
  42
  43 static struct kmem_cache *spufs_inode_cache;
  44 char *isolated_loader;
  45
  46 static struct inode *
  47 spufs_alloc_inode(struct super_block *sb)
  48 {
  49         struct spufs_inode_info *ei;
  50
  51         ei = kmem_cache_alloc(spufs_inode_cache, GFP_KERNEL);
  52         if (!ei)
  53                 return NULL;
  54
  55         ei->i_gang = NULL;
  56         ei->i_ctx = NULL;
  57         ei->i_openers = 0;
  58
  59         return &ei->vfs_inode;
  60 }
  61
  62 static void
  63 spufs_destroy_inode(struct inode *inode)
  64 {
  65         kmem_cache_free(spufs_inode_cache, SPUFS_I(inode));
  66 }
  67
  68 static void
  69 spufs_init_once(void *p, struct kmem_cache * cachep, unsigned long flags)
  70 {
  71         struct spufs_inode_info *ei = p;
  72
  73         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
  74             SLAB_CTOR_CONSTRUCTOR) {
  75                 inode_init_once(&ei->vfs_inode);
  76         }
  77 }
  78
  79 static struct inode *
  80 spufs_new_inode(struct super_block *sb, int mode)
  81 {
  82         struct inode *inode;
  83
  84         inode = new_inode(sb);
  85         if (!inode)
  86                 goto out;
  87
  88         inode->i_mode = mode;
  89         inode->i_uid = current->fsuid;
  90         inode->i_gid = current->fsgid;
  91         inode->i_blocks = 0;
  92         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
  93 out:
  94         return inode;
  95 }
  96
  97 static int
  98 spufs_setattr(struct dentry *dentry, struct iattr *attr)
  99 {
 100         struct inode *inode = dentry->d_inode;
 101
 102         if ((attr->ia_valid & ATTR_SIZE) &&
 103             (attr->ia_size != inode->i_size))
 104                 return -EINVAL;
 105         return inode_setattr(inode, attr);
 106 }
 107
 108
 109 static int
 110 spufs_new_file(struct super_block *sb, struct dentry *dentry,
 111                 const struct file_operations *fops, int mode,
 112                 struct spu_context *ctx)
 113 {
 114         static struct inode_operations spufs_file_iops = {
 115                 .setattr = spufs_setattr,
 116         };
 117         struct inode *inode;
 118         int ret;
 119
 120         ret = -ENOSPC;
 121         inode = spufs_new_inode(sb, S_IFREG | mode);
 122         if (!inode)
 123                 goto out;
 124
 125         ret = 0;
 126         inode->i_op = &spufs_file_iops;
 127         inode->i_fop = fops;
 128         inode->i_private = SPUFS_I(inode)->i_ctx = get_spu_context(ctx);
 129         d_add(dentry, inode);
 130 out:
 131         return ret;
 132 }
 133
 134 static void
 135 spufs_delete_inode(struct inode *inode)
 136 {
 137         struct spufs_inode_info *ei = SPUFS_I(inode);
 138
 139         if (ei->i_ctx)
 140                 put_spu_context(ei->i_ctx);
 141         if (ei->i_gang)
 142                 put_spu_gang(ei->i_gang);
 143         clear_inode(inode);
 144 }
 145
 146 static void spufs_prune_dir(struct dentry *dir)
 147 {
 148         struct dentry *dentry, *tmp;
 149
 150         mutex_lock(&dir->d_inode->i_mutex);
 151         list_for_each_entry_safe(dentry, tmp, &dir->d_subdirs, d_u.d_child) {
 152                 spin_lock(&dcache_lock);
 153                 spin_lock(&dentry->d_lock);
 154                 if (!(d_unhashed(dentry)) && dentry->d_inode) {
 155                         dget_locked(dentry);
 156                         __d_drop(dentry);
 157                         spin_unlock(&dentry->d_lock);
 158                         simple_unlink(dir->d_inode, dentry);
 159                         spin_unlock(&dcache_lock);
 160                         dput(dentry);
 161                 } else {
 162                         spin_unlock(&dentry->d_lock);
 163                         spin_unlock(&dcache_lock);
 164                 }
 165         }
 166         shrink_dcache_parent(dir);
 167         mutex_unlock(&dir->d_inode->i_mutex);
 168 }
 169
 170 /* Caller must hold parent->i_mutex */
 171 static int spufs_rmdir(struct inode *parent, struct dentry *dir)
 172 {
 173         /* remove all entries */
 174         spufs_prune_dir(dir);
 175
 176         return simple_rmdir(parent, dir);
 177 }
 178
 179 static int spufs_fill_dir(struct dentry *dir, struct tree_descr *files,
 180                           int mode, struct spu_context *ctx)
 181 {
 182         struct dentry *dentry;
 183         int ret;
 184
 185         while (files->name && files->name[0]) {
 186                 ret = -ENOMEM;
 187                 dentry = d_alloc_name(dir, files->name);
 188                 if (!dentry)
 189                         goto out;
 190                 ret = spufs_new_file(dir->d_sb, dentry, files->ops,
 191                                         files->mode & mode, ctx);
 192                 if (ret)
 193                         goto out;
 194                 files++;
 195         }
 196         return 0;
 197 out:
 198         spufs_prune_dir(dir);
 199         return ret;
 200 }
 201
 202 static int spufs_dir_close(struct inode *inode, struct file *file)
 203 {
 204         struct spu_context *ctx;
 205         struct inode *parent;
 206         struct dentry *dir;
 207         int ret;
 208
 209         dir = file->f_path.dentry;
 210         parent = dir->d_parent->d_inode;
 211         ctx = SPUFS_I(dir->d_inode)->i_ctx;
 212
 213         mutex_lock(&parent->i_mutex);
 214         ret = spufs_rmdir(parent, dir);
 215         mutex_unlock(&parent->i_mutex);
 216         WARN_ON(ret);
 217
 218         /* We have to give up the mm_struct */
 219         spu_forget(ctx);
 220
 221         return dcache_dir_close(inode, file);
 222 }
 223
 224 const struct inode_operations spufs_dir_inode_operations = {
 225         .lookup = simple_lookup,
 226 };
 227
 228 const struct file_operations spufs_context_fops = {
 229         .open           = dcache_dir_open,
 230         .release        = spufs_dir_close,
 231         .llseek         = dcache_dir_lseek,
 232         .read           = generic_read_dir,
 233         .readdir        = dcache_readdir,
 234         .fsync          = simple_sync_file,
 235 };
 236 EXPORT_SYMBOL_GPL(spufs_context_fops);
 237
 238 static int
 239 spufs_mkdir(struct inode *dir, struct dentry *dentry, unsigned int flags,
 240                 int mode)
 241 {
 242         int ret;
 243         struct inode *inode;
 244         struct spu_context *ctx;
 245
 246         ret = -ENOSPC;
 247         inode = spufs_new_inode(dir->i_sb, mode | S_IFDIR);
 248         if (!inode)
 249                 goto out;
 250
 251         if (dir->i_mode & S_ISGID) {
 252                 inode->i_gid = dir->i_gid;
 253                 inode->i_mode &= S_ISGID;
 254         }
 255         ctx = alloc_spu_context(SPUFS_I(dir)->i_gang); /* XXX gang */
 256         SPUFS_I(inode)->i_ctx = ctx;
 257         if (!ctx)
 258                 goto out_iput;
 259
 260         ctx->flags = flags;
 261         inode->i_op = &spufs_dir_inode_operations;
 262         inode->i_fop = &simple_dir_operations;
 263         if (flags & SPU_CREATE_NOSCHED)
 264                 ret = spufs_fill_dir(dentry, spufs_dir_nosched_contents,
 265                                          mode, ctx);
 266         else
 267                 ret = spufs_fill_dir(dentry, spufs_dir_contents, mode, ctx);
 268
 269         if (ret)
 270                 goto out_free_ctx;
 271
 272         d_instantiate(dentry, inode);
 273         dget(dentry);
 274         dir->i_nlink++;
 275         dentry->d_inode->i_nlink++;
 276         goto out;
 277
 278 out_free_ctx:
 279         put_spu_context(ctx);
 280 out_iput:
 281         iput(inode);
 282 out:
 283         return ret;
 284 }
 285
 286 static int spufs_context_open(struct dentry *dentry, struct vfsmount *mnt)
 287 {
 288         int ret;
 289         struct file *filp;
 290
 291         ret = get_unused_fd();
 292         if (ret < 0) {
 293                 dput(dentry);
 294                 mntput(mnt);
 295                 goto out;
 296         }
 297
 298         filp = dentry_open(dentry, mnt, O_RDONLY);
 299         if (IS_ERR(filp)) {
 300                 put_unused_fd(ret);
 301                 ret = PTR_ERR(filp);
 302                 goto out;
 303         }
 304
 305         filp->f_op = &spufs_context_fops;
 306         fd_install(ret, filp);
 307 out:
 308         return ret;
 309 }
 310
 311 static int spufs_create_context(struct inode *inode,
 312                         struct dentry *dentry,
 313                         struct vfsmount *mnt, int flags, int mode)
 314 {
 315         int ret;
 316
 317         ret = -EPERM;
 318         if ((flags & SPU_CREATE_NOSCHED) &&
 319             !capable(CAP_SYS_NICE))
 320                 goto out_unlock;
 321
 322         ret = -EINVAL;
 323         if ((flags & (SPU_CREATE_NOSCHED | SPU_CREATE_ISOLATE))
 324             == SPU_CREATE_ISOLATE)
 325                 goto out_unlock;
 326
 327         ret = -ENODEV;
 328         if ((flags & SPU_CREATE_ISOLATE) && !isolated_loader)
 329                 goto out_unlock;
 330
 331         ret = spufs_mkdir(inode, dentry, flags, mode & S_IRWXUGO);
 332         if (ret)
 333                 goto out_unlock;
 334
 335         /*
 336          * get references for dget and mntget, will be released
 337          * in error path of *_open().
 338          */
 339         ret = spufs_context_open(dget(dentry), mntget(mnt));
 340         if (ret < 0) {
 341                 WARN_ON(spufs_rmdir(inode, dentry));
 342                 mutex_unlock(&inode->i_mutex);
 343                 spu_forget(SPUFS_I(dentry->d_inode)->i_ctx);
 344                 goto out;
 345         }
 346
 347 out_unlock:
 348         mutex_unlock(&inode->i_mutex);
 349 out:
 350         dput(dentry);
 351         return ret;
 352 }
 353
 354 static int spufs_rmgang(struct inode *root, struct dentry *dir)
 355 {
 356         /* FIXME: this fails if the dir is not empty,
 357                   which causes a leak of gangs. */
 358         return simple_rmdir(root, dir);
 359 }
 360
 361 static int spufs_gang_close(struct inode *inode, struct file *file)
 362 {
 363         struct inode *parent;
 364         struct dentry *dir;
 365         int ret;
 366
 367         dir = file->f_path.dentry;
 368         parent = dir->d_parent->d_inode;
 369
 370         ret = spufs_rmgang(parent, dir);
 371         WARN_ON(ret);
 372
 373         return dcache_dir_close(inode, file);
 374 }
 375
 376 const struct file_operations spufs_gang_fops = {
 377         .open           = dcache_dir_open,
 378         .release        = spufs_gang_close,
 379         .llseek         = dcache_dir_lseek,
 380         .read           = generic_read_dir,
 381         .readdir        = dcache_readdir,
 382         .fsync          = simple_sync_file,
 383 };
 384
 385 static int
 386 spufs_mkgang(struct inode *dir, struct dentry *dentry, int mode)
 387 {
 388         int ret;
 389         struct inode *inode;
 390         struct spu_gang *gang;
 391
 392         ret = -ENOSPC;
 393         inode = spufs_new_inode(dir->i_sb, mode | S_IFDIR);
 394         if (!inode)
 395                 goto out;
 396
 397         ret = 0;
 398         if (dir->i_mode & S_ISGID) {
 399                 inode->i_gid = dir->i_gid;
 400                 inode->i_mode &= S_ISGID;
 401         }
 402         gang = alloc_spu_gang();
 403         SPUFS_I(inode)->i_ctx = NULL;
 404         SPUFS_I(inode)->i_gang = gang;
 405         if (!gang)
 406                 goto out_iput;
 407
 408         inode->i_op = &spufs_dir_inode_operations;
 409         inode->i_fop = &simple_dir_operations;
 410
 411         d_instantiate(dentry, inode);
 412         dget(dentry);
 413         dir->i_nlink++;
 414         dentry->d_inode->i_nlink++;
 415         return ret;
 416
 417 out_iput:
 418         iput(inode);
 419 out:
 420         return ret;
 421 }
 422
 423 static int spufs_gang_open(struct dentry *dentry, struct vfsmount *mnt)
 424 {
 425         int ret;
 426         struct file *filp;
 427
 428         ret = get_unused_fd();
 429         if (ret < 0) {
 430                 dput(dentry);
 431                 mntput(mnt);
 432                 goto out;
 433         }
 434
 435         filp = dentry_open(dentry, mnt, O_RDONLY);
 436         if (IS_ERR(filp)) {
 437                 put_unused_fd(ret);
 438                 ret = PTR_ERR(filp);
 439                 goto out;
 440         }
 441
 442         filp->f_op = &spufs_gang_fops;
 443         fd_install(ret, filp);
 444 out:
 445         return ret;
 446 }
 447
 448 static int spufs_create_gang(struct inode *inode,
 449                         struct dentry *dentry,
 450                         struct vfsmount *mnt, int mode)
 451 {
 452         int ret;
 453
 454         ret = spufs_mkgang(inode, dentry, mode & S_IRWXUGO);
 455         if (ret)
 456                 goto out;
 457
 458         /*
 459          * get references for dget and mntget, will be released
 460          * in error path of *_open().
 461          */
 462         ret = spufs_gang_open(dget(dentry), mntget(mnt));
 463         if (ret < 0)
 464                 WARN_ON(spufs_rmgang(inode, dentry));
 465
 466 out:
 467         mutex_unlock(&inode->i_mutex);
 468         dput(dentry);
 469         return ret;
 470 }
 471
 472
 473 static struct file_system_type spufs_type;
 474
 475 long spufs_create(struct nameidata *nd, unsigned int flags, mode_t mode)
 476 {
 477         struct dentry *dentry;
 478         int ret;
 479
 480         ret = -EINVAL;
 481         /* check if we are on spufs */
 482         if (nd->dentry->d_sb->s_type != &spufs_type)
 483                 goto out;
 484
 485         /* don't accept undefined flags */
 486         if (flags & (~SPU_CREATE_FLAG_ALL))
 487                 goto out;
 488
 489         /* only threads can be underneath a gang */
 490         if (nd->dentry != nd->dentry->d_sb->s_root) {
 491                 if ((flags & SPU_CREATE_GANG) ||
 492                     !SPUFS_I(nd->dentry->d_inode)->i_gang)
 493                         goto out;
 494         }
 495
 496         dentry = lookup_create(nd, 1);
 497         ret = PTR_ERR(dentry);
 498         if (IS_ERR(dentry))
 499                 goto out_dir;
 500
 501         ret = -EEXIST;
 502         if (dentry->d_inode)
 503                 goto out_dput;
 504
 505         mode &= ~current->fs->umask;
 506
 507         if (flags & SPU_CREATE_GANG)
 508                 return spufs_create_gang(nd->dentry->d_inode,
 509                                         dentry, nd->mnt, mode);
 510         else
 511                 return spufs_create_context(nd->dentry->d_inode,
 512                                         dentry, nd->mnt, flags, mode);
 513
 514 out_dput:
 515         dput(dentry);
 516 out_dir:
 517         mutex_unlock(&nd->dentry->d_inode->i_mutex);
 518 out:
 519         return ret;
 520 }
 521
 522 /* File system initialization */
 523 enum {
 524         Opt_uid, Opt_gid, Opt_err,
 525 };
 526
 527 static match_table_t spufs_tokens = {
 528         { Opt_uid, "uid=%d" },
 529         { Opt_gid, "gid=%d" },
 530         { Opt_err, NULL  },
 531 };
 532
 533 static int
 534 spufs_parse_options(char *options, struct inode *root)
 535 {
 536         char *p;
 537         substring_t args[MAX_OPT_ARGS];
 538
 539         while ((p = strsep(&options, ",")) != NULL) {
 540                 int token, option;
 541
 542                 if (!*p)
 543                         continue;
 544
 545                 token = match_token(p, spufs_tokens, args);
 546                 switch (token) {
 547                 case Opt_uid:
 548                         if (match_int(&args[0], &option))
 549                                 return 0;
 550                         root->i_uid = option;
 551                         break;
 552                 case Opt_gid:
 553                         if (match_int(&args[0], &option))
 554                                 return 0;
 555                         root->i_gid = option;
 556                         break;
 557                 default:
 558                         return 0;
 559                 }
 560         }
 561         return 1;
 562 }
 563
 564 static void
 565 spufs_init_isolated_loader(void)
 566 {
 567         struct device_node *dn;
 568         const char *loader;
 569         int size;
 570
 571         dn = of_find_node_by_path("/spu-isolation");
 572         if (!dn)
 573                 return;
 574
 575         loader = of_get_property(dn, "loader", &size);
 576         if (!loader)
 577                 return;
 578
 579         /* kmalloc should align on a 16 byte boundary..* */
 580         isolated_loader = kmalloc(size, GFP_KERNEL);
 581         if (!isolated_loader)
 582                 return;
 583
 584         memcpy(isolated_loader, loader, size);
 585         printk(KERN_INFO "spufs: SPU isolation mode enabled\n");
 586 }
 587
 588 static int
 589 spufs_create_root(struct super_block *sb, void *data)
 590 {
 591         struct inode *inode;
 592         int ret;
 593
 594         ret = -ENOMEM;
 595         inode = spufs_new_inode(sb, S_IFDIR | 0775);
 596         if (!inode)
 597                 goto out;
 598
 599         inode->i_op = &spufs_dir_inode_operations;
 600         inode->i_fop = &simple_dir_operations;
 601         SPUFS_I(inode)->i_ctx = NULL;
 602
 603         ret = -EINVAL;
 604         if (!spufs_parse_options(data, inode))
 605                 goto out_iput;
 606
 607         ret = -ENOMEM;
 608         sb->s_root = d_alloc_root(inode);
 609         if (!sb->s_root)
 610                 goto out_iput;
 611
 612         return 0;
 613 out_iput:
 614         iput(inode);
 615 out:
 616         return ret;
 617 }
 618
 619 static int
 620 spufs_fill_super(struct super_block *sb, void *data, int silent)
 621 {
 622         static struct super_operations s_ops = {
 623                 .alloc_inode = spufs_alloc_inode,
 624                 .destroy_inode = spufs_destroy_inode,
 625                 .statfs = simple_statfs,
 626                 .delete_inode = spufs_delete_inode,
 627                 .drop_inode = generic_delete_inode,
 628         };
 629
 630         sb->s_maxbytes = MAX_LFS_FILESIZE;
 631         sb->s_blocksize = PAGE_CACHE_SIZE;
 632         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 633         sb->s_magic = SPUFS_MAGIC;
 634         sb->s_op = &s_ops;
 635
 636         return spufs_create_root(sb, data);
 637 }
 638
 639 static int
 640 spufs_get_sb(struct file_system_type *fstype, int flags,
 641                 const char *name, void *data, struct vfsmount *mnt)
 642 {
 643         return get_sb_single(fstype, flags, data, spufs_fill_super, mnt);
 644 }
 645
 646 static struct file_system_type spufs_type = {
 647         .owner = THIS_MODULE,
 648         .name = "spufs",
 649         .get_sb = spufs_get_sb,
 650         .kill_sb = kill_litter_super,
 651 };
 652
 653 static int __init spufs_init(void)
 654 {
 655         int ret;
 656
 657         ret = -ENOMEM;
 658         spufs_inode_cache = kmem_cache_create("spufs_inode_cache",
 659                         sizeof(struct spufs_inode_info), 0,
 660                         SLAB_HWCACHE_ALIGN, spufs_init_once, NULL);
 661
 662         if (!spufs_inode_cache)
 663                 goto out;
 664         ret = spu_sched_init();
 665         if (ret)
 666                 goto out_cache;
 667         ret = register_filesystem(&spufs_type);
 668         if (ret)
 669                 goto out_sched;
 670         ret = register_spu_syscalls(&spufs_calls);
 671         if (ret)
 672                 goto out_fs;
 673         ret = register_arch_coredump_calls(&spufs_coredump_calls);
 674         if (ret)
 675                 goto out_syscalls;
 676
 677         spufs_init_isolated_loader();
 678
 679         return 0;
 680
 681 out_syscalls:
 682         unregister_spu_syscalls(&spufs_calls);
 683 out_fs:
 684         unregister_filesystem(&spufs_type);
 685 out_sched:
 686         spu_sched_exit();
 687 out_cache:
 688         kmem_cache_destroy(spufs_inode_cache);
 689 out:
 690         return ret;
 691 }
 692 module_init(spufs_init);
 693
 694 static void __exit spufs_exit(void)
 695 {
 696         spu_sched_exit();
 697         unregister_arch_coredump_calls(&spufs_coredump_calls);
 698         unregister_spu_syscalls(&spufs_calls);
 699         unregister_filesystem(&spufs_type);
 700         kmem_cache_destroy(spufs_inode_cache);
 701 }
 702 module_exit(spufs_exit);
 703
 704 MODULE_LICENSE("GPL");
 705 MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
 706