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/io.h>
  37 #include <asm/semaphore.h>
  38 #include <asm/spu.h>
  39 #include <asm/uaccess.h>
  40
  41 #include "spufs.h"
  42
  43 static kmem_cache_t *spufs_inode_cache;
  44
  45 static struct inode *
  46 spufs_alloc_inode(struct super_block *sb)
  47 {
  48         struct spufs_inode_info *ei;
  49
  50         ei = kmem_cache_alloc(spufs_inode_cache, SLAB_KERNEL);
  51         if (!ei)
  52                 return NULL;
  53
  54         ei->i_gang = NULL;
  55         ei->i_ctx = NULL;
  56
  57         return &ei->vfs_inode;
  58 }
  59
  60 static void
  61 spufs_destroy_inode(struct inode *inode)
  62 {
  63         kmem_cache_free(spufs_inode_cache, SPUFS_I(inode));
  64 }
  65
  66 static void
  67 spufs_init_once(void *p, kmem_cache_t * cachep, unsigned long flags)
  68 {
  69         struct spufs_inode_info *ei = p;
  70
  71         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
  72             SLAB_CTOR_CONSTRUCTOR) {
  73                 inode_init_once(&ei->vfs_inode);
  74         }
  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_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 struct inode_operations spufs_dir_inode_operations = {
 223         .lookup = simple_lookup,
 224 };
 225
 226 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
 235 static int
 236 spufs_mkdir(struct inode *dir, struct dentry *dentry, unsigned int flags,
 237                 int mode)
 238 {
 239         int ret;
 240         struct inode *inode;
 241         struct spu_context *ctx;
 242
 243         ret = -ENOSPC;
 244         inode = spufs_new_inode(dir->i_sb, mode | S_IFDIR);
 245         if (!inode)
 246                 goto out;
 247
 248         if (dir->i_mode & S_ISGID) {
 249                 inode->i_gid = dir->i_gid;
 250                 inode->i_mode &= S_ISGID;
 251         }
 252         ctx = alloc_spu_context(SPUFS_I(dir)->i_gang); /* XXX gang */
 253         SPUFS_I(inode)->i_ctx = ctx;
 254         if (!ctx)
 255                 goto out_iput;
 256
 257         ctx->flags = flags;
 258
 259         inode->i_op = &spufs_dir_inode_operations;
 260         inode->i_fop = &simple_dir_operations;
 261         ret = spufs_fill_dir(dentry, spufs_dir_contents, mode, ctx);
 262         if (ret)
 263                 goto out_free_ctx;
 264
 265         d_instantiate(dentry, inode);
 266         dget(dentry);
 267         dir->i_nlink++;
 268         dentry->d_inode->i_nlink++;
 269         goto out;
 270
 271 out_free_ctx:
 272         put_spu_context(ctx);
 273 out_iput:
 274         iput(inode);
 275 out:
 276         return ret;
 277 }
 278
 279 static int spufs_context_open(struct dentry *dentry, struct vfsmount *mnt)
 280 {
 281         int ret;
 282         struct file *filp;
 283
 284         ret = get_unused_fd();
 285         if (ret < 0) {
 286                 dput(dentry);
 287                 mntput(mnt);
 288                 goto out;
 289         }
 290
 291         filp = dentry_open(dentry, mnt, O_RDONLY);
 292         if (IS_ERR(filp)) {
 293                 put_unused_fd(ret);
 294                 ret = PTR_ERR(filp);
 295                 goto out;
 296         }
 297
 298         filp->f_op = &spufs_context_fops;
 299         fd_install(ret, filp);
 300 out:
 301         return ret;
 302 }
 303
 304 static int spufs_create_context(struct inode *inode,
 305                         struct dentry *dentry,
 306                         struct vfsmount *mnt, int flags, int mode)
 307 {
 308         int ret;
 309
 310         ret = spufs_mkdir(inode, dentry, flags, mode & S_IRWXUGO);
 311         if (ret)
 312                 goto out_unlock;
 313
 314         /*
 315          * get references for dget and mntget, will be released
 316          * in error path of *_open().
 317          */
 318         ret = spufs_context_open(dget(dentry), mntget(mnt));
 319         if (ret < 0) {
 320                 WARN_ON(spufs_rmdir(inode, dentry));
 321                 mutex_unlock(&inode->i_mutex);
 322                 spu_forget(SPUFS_I(dentry->d_inode)->i_ctx);
 323                 goto out;
 324         }
 325
 326 out_unlock:
 327         mutex_unlock(&inode->i_mutex);
 328 out:
 329         dput(dentry);
 330         return ret;
 331 }
 332
 333 static int spufs_rmgang(struct inode *root, struct dentry *dir)
 334 {
 335         /* FIXME: this fails if the dir is not empty,
 336                   which causes a leak of gangs. */
 337         return simple_rmdir(root, dir);
 338 }
 339
 340 static int spufs_gang_close(struct inode *inode, struct file *file)
 341 {
 342         struct inode *parent;
 343         struct dentry *dir;
 344         int ret;
 345
 346         dir = file->f_dentry;
 347         parent = dir->d_parent->d_inode;
 348
 349         ret = spufs_rmgang(parent, dir);
 350         WARN_ON(ret);
 351
 352         return dcache_dir_close(inode, file);
 353 }
 354
 355 struct file_operations spufs_gang_fops = {
 356         .open           = dcache_dir_open,
 357         .release        = spufs_gang_close,
 358         .llseek         = dcache_dir_lseek,
 359         .read           = generic_read_dir,
 360         .readdir        = dcache_readdir,
 361         .fsync          = simple_sync_file,
 362 };
 363
 364 static int
 365 spufs_mkgang(struct inode *dir, struct dentry *dentry, int mode)
 366 {
 367         int ret;
 368         struct inode *inode;
 369         struct spu_gang *gang;
 370
 371         ret = -ENOSPC;
 372         inode = spufs_new_inode(dir->i_sb, mode | S_IFDIR);
 373         if (!inode)
 374                 goto out;
 375
 376         ret = 0;
 377         if (dir->i_mode & S_ISGID) {
 378                 inode->i_gid = dir->i_gid;
 379                 inode->i_mode &= S_ISGID;
 380         }
 381         gang = alloc_spu_gang();
 382         SPUFS_I(inode)->i_ctx = NULL;
 383         SPUFS_I(inode)->i_gang = gang;
 384         if (!gang)
 385                 goto out_iput;
 386
 387         inode->i_op = &spufs_dir_inode_operations;
 388         inode->i_fop = &simple_dir_operations;
 389
 390         d_instantiate(dentry, inode);
 391         dget(dentry);
 392         dir->i_nlink++;
 393         dentry->d_inode->i_nlink++;
 394         return ret;
 395
 396 out_iput:
 397         iput(inode);
 398 out:
 399         return ret;
 400 }
 401
 402 static int spufs_gang_open(struct dentry *dentry, struct vfsmount *mnt)
 403 {
 404         int ret;
 405         struct file *filp;
 406
 407         ret = get_unused_fd();
 408         if (ret < 0) {
 409                 dput(dentry);
 410                 mntput(mnt);
 411                 goto out;
 412         }
 413
 414         filp = dentry_open(dentry, mnt, O_RDONLY);
 415         if (IS_ERR(filp)) {
 416                 put_unused_fd(ret);
 417                 ret = PTR_ERR(filp);
 418                 goto out;
 419         }
 420
 421         filp->f_op = &spufs_gang_fops;
 422         fd_install(ret, filp);
 423 out:
 424         return ret;
 425 }
 426
 427 static int spufs_create_gang(struct inode *inode,
 428                         struct dentry *dentry,
 429                         struct vfsmount *mnt, int mode)
 430 {
 431         int ret;
 432
 433         ret = spufs_mkgang(inode, dentry, mode & S_IRWXUGO);
 434         if (ret)
 435                 goto out;
 436
 437         /*
 438          * get references for dget and mntget, will be released
 439          * in error path of *_open().
 440          */
 441         ret = spufs_gang_open(dget(dentry), mntget(mnt));
 442         if (ret < 0)
 443                 WARN_ON(spufs_rmgang(inode, dentry));
 444
 445 out:
 446         mutex_unlock(&inode->i_mutex);
 447         dput(dentry);
 448         return ret;
 449 }
 450
 451
 452 static struct file_system_type spufs_type;
 453
 454 long spufs_create(struct nameidata *nd, unsigned int flags, mode_t mode)
 455 {
 456         struct dentry *dentry;
 457         int ret;
 458
 459         ret = -EINVAL;
 460         /* check if we are on spufs */
 461         if (nd->dentry->d_sb->s_type != &spufs_type)
 462                 goto out;
 463
 464         /* don't accept undefined flags */
 465         if (flags & (~SPU_CREATE_FLAG_ALL))
 466                 goto out;
 467
 468         /* only threads can be underneath a gang */
 469         if (nd->dentry != nd->dentry->d_sb->s_root) {
 470                 if ((flags & SPU_CREATE_GANG) ||
 471                     !SPUFS_I(nd->dentry->d_inode)->i_gang)
 472                         goto out;
 473         }
 474
 475         dentry = lookup_create(nd, 1);
 476         ret = PTR_ERR(dentry);
 477         if (IS_ERR(dentry))
 478                 goto out_dir;
 479
 480         ret = -EEXIST;
 481         if (dentry->d_inode)
 482                 goto out_dput;
 483
 484         mode &= ~current->fs->umask;
 485
 486         if (flags & SPU_CREATE_GANG)
 487                 return spufs_create_gang(nd->dentry->d_inode,
 488                                         dentry, nd->mnt, mode);
 489         else
 490                 return spufs_create_context(nd->dentry->d_inode,
 491                                         dentry, nd->mnt, flags, mode);
 492
 493 out_dput:
 494         dput(dentry);
 495 out_dir:
 496         mutex_unlock(&nd->dentry->d_inode->i_mutex);
 497 out:
 498         return ret;
 499 }
 500
 501 /* File system initialization */
 502 enum {
 503         Opt_uid, Opt_gid, Opt_err,
 504 };
 505
 506 static match_table_t spufs_tokens = {
 507         { Opt_uid, "uid=%d" },
 508         { Opt_gid, "gid=%d" },
 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                 default:
 537                         return 0;
 538                 }
 539         }
 540         return 1;
 541 }
 542
 543 static int
 544 spufs_create_root(struct super_block *sb, void *data)
 545 {
 546         struct inode *inode;
 547         int ret;
 548
 549         ret = -ENOMEM;
 550         inode = spufs_new_inode(sb, S_IFDIR | 0775);
 551         if (!inode)
 552                 goto out;
 553
 554         inode->i_op = &spufs_dir_inode_operations;
 555         inode->i_fop = &simple_dir_operations;
 556         SPUFS_I(inode)->i_ctx = NULL;
 557
 558         ret = -EINVAL;
 559         if (!spufs_parse_options(data, inode))
 560                 goto out_iput;
 561
 562         ret = -ENOMEM;
 563         sb->s_root = d_alloc_root(inode);
 564         if (!sb->s_root)
 565                 goto out_iput;
 566
 567         return 0;
 568 out_iput:
 569         iput(inode);
 570 out:
 571         return ret;
 572 }
 573
 574 static int
 575 spufs_fill_super(struct super_block *sb, void *data, int silent)
 576 {
 577         static struct super_operations s_ops = {
 578                 .alloc_inode = spufs_alloc_inode,
 579                 .destroy_inode = spufs_destroy_inode,
 580                 .statfs = simple_statfs,
 581                 .delete_inode = spufs_delete_inode,
 582                 .drop_inode = generic_delete_inode,
 583         };
 584
 585         sb->s_maxbytes = MAX_LFS_FILESIZE;
 586         sb->s_blocksize = PAGE_CACHE_SIZE;
 587         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 588         sb->s_magic = SPUFS_MAGIC;
 589         sb->s_op = &s_ops;
 590
 591         return spufs_create_root(sb, data);
 592 }
 593
 594 static int
 595 spufs_get_sb(struct file_system_type *fstype, int flags,
 596                 const char *name, void *data, struct vfsmount *mnt)
 597 {
 598         return get_sb_single(fstype, flags, data, spufs_fill_super, mnt);
 599 }
 600
 601 static struct file_system_type spufs_type = {
 602         .owner = THIS_MODULE,
 603         .name = "spufs",
 604         .get_sb = spufs_get_sb,
 605         .kill_sb = kill_litter_super,
 606 };
 607
 608 static int __init spufs_init(void)
 609 {
 610         int ret;
 611         ret = -ENOMEM;
 612         spufs_inode_cache = kmem_cache_create("spufs_inode_cache",
 613                         sizeof(struct spufs_inode_info), 0,
 614                         SLAB_HWCACHE_ALIGN, spufs_init_once, NULL);
 615
 616         if (!spufs_inode_cache)
 617                 goto out;
 618         if (spu_sched_init() != 0) {
 619                 kmem_cache_destroy(spufs_inode_cache);
 620                 goto out;
 621         }
 622         ret = register_filesystem(&spufs_type);
 623         if (ret)
 624                 goto out_cache;
 625         ret = register_spu_syscalls(&spufs_calls);
 626         if (ret)
 627                 goto out_fs;
 628         return 0;
 629 out_fs:
 630         unregister_filesystem(&spufs_type);
 631 out_cache:
 632         kmem_cache_destroy(spufs_inode_cache);
 633 out:
 634         return ret;
 635 }
 636 module_init(spufs_init);
 637
 638 static void __exit spufs_exit(void)
 639 {
 640         spu_sched_exit();
 641         unregister_spu_syscalls(&spufs_calls);
 642         unregister_filesystem(&spufs_type);
 643         kmem_cache_destroy(spufs_inode_cache);
 644 }
 645 module_exit(spufs_exit);
 646
 647 MODULE_LICENSE("GPL");
 648 MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
 649