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