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