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         put_spu_context(ctx);
 278 out_iput:
 279         iput(inode);
 280 out:
 281         return ret;
 282 }
 283
 284 static int spufs_context_open(struct dentry *dentry, struct vfsmount *mnt)
 285 {
 286         int ret;
 287         struct file *filp;
 288
 289         ret = get_unused_fd();
 290         if (ret < 0) {
 291                 dput(dentry);
 292                 mntput(mnt);
 293                 goto out;
 294         }
 295
 296         filp = dentry_open(dentry, mnt, O_RDONLY);
 297         if (IS_ERR(filp)) {
 298                 put_unused_fd(ret);
 299                 ret = PTR_ERR(filp);
 300                 goto out;
 301         }
 302
 303         filp->f_op = &spufs_context_fops;
 304         fd_install(ret, filp);
 305 out:
 306         return ret;
 307 }
 308
 309 static int spufs_create_context(struct inode *inode,
 310                         struct dentry *dentry,
 311                         struct vfsmount *mnt, int flags, int mode)
 312 {
 313         int ret;
 314
 315         ret = -EPERM;
 316         if ((flags & SPU_CREATE_NOSCHED) &&
 317             !capable(CAP_SYS_NICE))
 318                 goto out_unlock;
 319
 320         ret = -EINVAL;
 321         if ((flags & (SPU_CREATE_NOSCHED | SPU_CREATE_ISOLATE))
 322             == SPU_CREATE_ISOLATE)
 323                 goto out_unlock;
 324
 325         ret = -ENODEV;
 326         if ((flags & SPU_CREATE_ISOLATE) && !isolated_loader)
 327                 goto out_unlock;
 328
 329         ret = spufs_mkdir(inode, dentry, flags, mode & S_IRWXUGO);
 330         if (ret)
 331                 goto out_unlock;
 332
 333         /*
 334          * get references for dget and mntget, will be released
 335          * in error path of *_open().
 336          */
 337         ret = spufs_context_open(dget(dentry), mntget(mnt));
 338         if (ret < 0) {
 339                 WARN_ON(spufs_rmdir(inode, dentry));
 340                 mutex_unlock(&inode->i_mutex);
 341                 spu_forget(SPUFS_I(dentry->d_inode)->i_ctx);
 342                 goto out;
 343         }
 344
 345 out_unlock:
 346         mutex_unlock(&inode->i_mutex);
 347 out:
 348         dput(dentry);
 349         return ret;
 350 }
 351
 352 static int spufs_rmgang(struct inode *root, struct dentry *dir)
 353 {
 354         /* FIXME: this fails if the dir is not empty,
 355                   which causes a leak of gangs. */
 356         return simple_rmdir(root, dir);
 357 }
 358
 359 static int spufs_gang_close(struct inode *inode, struct file *file)
 360 {
 361         struct inode *parent;
 362         struct dentry *dir;
 363         int ret;
 364
 365         dir = file->f_path.dentry;
 366         parent = dir->d_parent->d_inode;
 367
 368         ret = spufs_rmgang(parent, dir);
 369         WARN_ON(ret);
 370
 371         return dcache_dir_close(inode, file);
 372 }
 373
 374 const struct file_operations spufs_gang_fops = {
 375         .open           = dcache_dir_open,
 376         .release        = spufs_gang_close,
 377         .llseek         = dcache_dir_lseek,
 378         .read           = generic_read_dir,
 379         .readdir        = dcache_readdir,
 380         .fsync          = simple_sync_file,
 381 };
 382
 383 static int
 384 spufs_mkgang(struct inode *dir, struct dentry *dentry, int mode)
 385 {
 386         int ret;
 387         struct inode *inode;
 388         struct spu_gang *gang;
 389
 390         ret = -ENOSPC;
 391         inode = spufs_new_inode(dir->i_sb, mode | S_IFDIR);
 392         if (!inode)
 393                 goto out;
 394
 395         ret = 0;
 396         if (dir->i_mode & S_ISGID) {
 397                 inode->i_gid = dir->i_gid;
 398                 inode->i_mode &= S_ISGID;
 399         }
 400         gang = alloc_spu_gang();
 401         SPUFS_I(inode)->i_ctx = NULL;
 402         SPUFS_I(inode)->i_gang = gang;
 403         if (!gang)
 404                 goto out_iput;
 405
 406         inode->i_op = &spufs_dir_inode_operations;
 407         inode->i_fop = &simple_dir_operations;
 408
 409         d_instantiate(dentry, inode);
 410         dget(dentry);
 411         dir->i_nlink++;
 412         dentry->d_inode->i_nlink++;
 413         return ret;
 414
 415 out_iput:
 416         iput(inode);
 417 out:
 418         return ret;
 419 }
 420
 421 static int spufs_gang_open(struct dentry *dentry, struct vfsmount *mnt)
 422 {
 423         int ret;
 424         struct file *filp;
 425
 426         ret = get_unused_fd();
 427         if (ret < 0) {
 428                 dput(dentry);
 429                 mntput(mnt);
 430                 goto out;
 431         }
 432
 433         filp = dentry_open(dentry, mnt, O_RDONLY);
 434         if (IS_ERR(filp)) {
 435                 put_unused_fd(ret);
 436                 ret = PTR_ERR(filp);
 437                 goto out;
 438         }
 439
 440         filp->f_op = &spufs_gang_fops;
 441         fd_install(ret, filp);
 442 out:
 443         return ret;
 444 }
 445
 446 static int spufs_create_gang(struct inode *inode,
 447                         struct dentry *dentry,
 448                         struct vfsmount *mnt, int mode)
 449 {
 450         int ret;
 451
 452         ret = spufs_mkgang(inode, dentry, mode & S_IRWXUGO);
 453         if (ret)
 454                 goto out;
 455
 456         /*
 457          * get references for dget and mntget, will be released
 458          * in error path of *_open().
 459          */
 460         ret = spufs_gang_open(dget(dentry), mntget(mnt));
 461         if (ret < 0)
 462                 WARN_ON(spufs_rmgang(inode, dentry));
 463
 464 out:
 465         mutex_unlock(&inode->i_mutex);
 466         dput(dentry);
 467         return ret;
 468 }
 469
 470
 471 static struct file_system_type spufs_type;
 472
 473 long spufs_create(struct nameidata *nd, unsigned int flags, mode_t mode)
 474 {
 475         struct dentry *dentry;
 476         int ret;
 477
 478         ret = -EINVAL;
 479         /* check if we are on spufs */
 480         if (nd->dentry->d_sb->s_type != &spufs_type)
 481                 goto out;
 482
 483         /* don't accept undefined flags */
 484         if (flags & (~SPU_CREATE_FLAG_ALL))
 485                 goto out;
 486
 487         /* only threads can be underneath a gang */
 488         if (nd->dentry != nd->dentry->d_sb->s_root) {
 489                 if ((flags & SPU_CREATE_GANG) ||
 490                     !SPUFS_I(nd->dentry->d_inode)->i_gang)
 491                         goto out;
 492         }
 493
 494         dentry = lookup_create(nd, 1);
 495         ret = PTR_ERR(dentry);
 496         if (IS_ERR(dentry))
 497                 goto out_dir;
 498
 499         ret = -EEXIST;
 500         if (dentry->d_inode)
 501                 goto out_dput;
 502
 503         mode &= ~current->fs->umask;
 504
 505         if (flags & SPU_CREATE_GANG)
 506                 return spufs_create_gang(nd->dentry->d_inode,
 507                                         dentry, nd->mnt, mode);
 508         else
 509                 return spufs_create_context(nd->dentry->d_inode,
 510                                         dentry, nd->mnt, flags, mode);
 511
 512 out_dput:
 513         dput(dentry);
 514 out_dir:
 515         mutex_unlock(&nd->dentry->d_inode->i_mutex);
 516 out:
 517         return ret;
 518 }
 519
 520 /* File system initialization */
 521 enum {
 522         Opt_uid, Opt_gid, Opt_mode, Opt_err,
 523 };
 524
 525 static match_table_t spufs_tokens = {
 526         { Opt_uid,  "uid=%d" },
 527         { Opt_gid,  "gid=%d" },
 528         { Opt_mode, "mode=%o" },
 529         { Opt_err,   NULL  },
 530 };
 531
 532 static int
 533 spufs_parse_options(char *options, struct inode *root)
 534 {
 535         char *p;
 536         substring_t args[MAX_OPT_ARGS];
 537
 538         while ((p = strsep(&options, ",")) != NULL) {
 539                 int token, option;
 540
 541                 if (!*p)
 542                         continue;
 543
 544                 token = match_token(p, spufs_tokens, args);
 545                 switch (token) {
 546                 case Opt_uid:
 547                         if (match_int(&args[0], &option))
 548                                 return 0;
 549                         root->i_uid = option;
 550                         break;
 551                 case Opt_gid:
 552                         if (match_int(&args[0], &option))
 553                                 return 0;
 554                         root->i_gid = option;
 555                         break;
 556                 case Opt_mode:
 557                         if (match_octal(&args[0], &option))
 558                                 return 0;
 559                         root->i_mode = option | S_IFDIR;
 560                         break;
 561                 default:
 562                         return 0;
 563                 }
 564         }
 565         return 1;
 566 }
 567
 568 static void spufs_exit_isolated_loader(void)
 569 {
 570         kfree(isolated_loader);
 571 }
 572
 573 static void
 574 spufs_init_isolated_loader(void)
 575 {
 576         struct device_node *dn;
 577         const char *loader;
 578         int size;
 579
 580         dn = of_find_node_by_path("/spu-isolation");
 581         if (!dn)
 582                 return;
 583
 584         loader = of_get_property(dn, "loader", &size);
 585         if (!loader)
 586                 return;
 587
 588         /* kmalloc should align on a 16 byte boundary..* */
 589         isolated_loader = kmalloc(size, GFP_KERNEL);
 590         if (!isolated_loader)
 591                 return;
 592
 593         memcpy(isolated_loader, loader, size);
 594         printk(KERN_INFO "spufs: SPU isolation mode enabled\n");
 595 }
 596
 597 static int
 598 spufs_create_root(struct super_block *sb, void *data)
 599 {
 600         struct inode *inode;
 601         int ret;
 602
 603         ret = -ENOMEM;
 604         inode = spufs_new_inode(sb, S_IFDIR | 0775);
 605         if (!inode)
 606                 goto out;
 607
 608         inode->i_op = &spufs_dir_inode_operations;
 609         inode->i_fop = &simple_dir_operations;
 610         SPUFS_I(inode)->i_ctx = NULL;
 611
 612         ret = -EINVAL;
 613         if (!spufs_parse_options(data, inode))
 614                 goto out_iput;
 615
 616         ret = -ENOMEM;
 617         sb->s_root = d_alloc_root(inode);
 618         if (!sb->s_root)
 619                 goto out_iput;
 620
 621         return 0;
 622 out_iput:
 623         iput(inode);
 624 out:
 625         return ret;
 626 }
 627
 628 static int
 629 spufs_fill_super(struct super_block *sb, void *data, int silent)
 630 {
 631         static struct super_operations s_ops = {
 632                 .alloc_inode = spufs_alloc_inode,
 633                 .destroy_inode = spufs_destroy_inode,
 634                 .statfs = simple_statfs,
 635                 .delete_inode = spufs_delete_inode,
 636                 .drop_inode = generic_delete_inode,
 637         };
 638
 639         sb->s_maxbytes = MAX_LFS_FILESIZE;
 640         sb->s_blocksize = PAGE_CACHE_SIZE;
 641         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 642         sb->s_magic = SPUFS_MAGIC;
 643         sb->s_op = &s_ops;
 644
 645         return spufs_create_root(sb, data);
 646 }
 647
 648 static int
 649 spufs_get_sb(struct file_system_type *fstype, int flags,
 650                 const char *name, void *data, struct vfsmount *mnt)
 651 {
 652         return get_sb_single(fstype, flags, data, spufs_fill_super, mnt);
 653 }
 654
 655 static struct file_system_type spufs_type = {
 656         .owner = THIS_MODULE,
 657         .name = "spufs",
 658         .get_sb = spufs_get_sb,
 659         .kill_sb = kill_litter_super,
 660 };
 661
 662 static int __init spufs_init(void)
 663 {
 664         int ret;
 665
 666         ret = -ENODEV;
 667         if (!spu_management_ops)
 668                 goto out;
 669
 670         ret = -ENOMEM;
 671         spufs_inode_cache = kmem_cache_create("spufs_inode_cache",
 672                         sizeof(struct spufs_inode_info), 0,
 673                         SLAB_HWCACHE_ALIGN, spufs_init_once, NULL);
 674
 675         if (!spufs_inode_cache)
 676                 goto out;
 677         ret = spu_sched_init();
 678         if (ret)
 679                 goto out_cache;
 680         ret = register_filesystem(&spufs_type);
 681         if (ret)
 682                 goto out_sched;
 683         ret = register_spu_syscalls(&spufs_calls);
 684         if (ret)
 685                 goto out_fs;
 686         ret = register_arch_coredump_calls(&spufs_coredump_calls);
 687         if (ret)
 688                 goto out_syscalls;
 689
 690         spufs_init_isolated_loader();
 691
 692         return 0;
 693
 694 out_syscalls:
 695         unregister_spu_syscalls(&spufs_calls);
 696 out_fs:
 697         unregister_filesystem(&spufs_type);
 698 out_sched:
 699         spu_sched_exit();
 700 out_cache:
 701         kmem_cache_destroy(spufs_inode_cache);
 702 out:
 703         return ret;
 704 }
 705 module_init(spufs_init);
 706
 707 static void __exit spufs_exit(void)
 708 {
 709         spu_sched_exit();
 710         spufs_exit_isolated_loader();
 711         unregister_arch_coredump_calls(&spufs_coredump_calls);
 712         unregister_spu_syscalls(&spufs_calls);
 713         unregister_filesystem(&spufs_type);
 714         kmem_cache_destroy(spufs_inode_cache);
 715 }
 716 module_exit(spufs_exit);
 717
 718 MODULE_LICENSE("GPL");
 719 MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
 720