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         return &ei->vfs_inode;
  54 }
  55
  56 static void
  57 spufs_destroy_inode(struct inode *inode)
  58 {
  59         kmem_cache_free(spufs_inode_cache, SPUFS_I(inode));
  60 }
  61
  62 static void
  63 spufs_init_once(void *p, kmem_cache_t * cachep, unsigned long flags)
  64 {
  65         struct spufs_inode_info *ei = p;
  66
  67         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
  68             SLAB_CTOR_CONSTRUCTOR) {
  69                 inode_init_once(&ei->vfs_inode);
  70         }
  71 }
  72
  73 static struct inode *
  74 spufs_new_inode(struct super_block *sb, int mode)
  75 {
  76         struct inode *inode;
  77
  78         inode = new_inode(sb);
  79         if (!inode)
  80                 goto out;
  81
  82         inode->i_mode = mode;
  83         inode->i_uid = current->fsuid;
  84         inode->i_gid = current->fsgid;
  85         inode->i_blksize = PAGE_CACHE_SIZE;
  86         inode->i_blocks = 0;
  87         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
  88 out:
  89         return inode;
  90 }
  91
  92 static int
  93 spufs_setattr(struct dentry *dentry, struct iattr *attr)
  94 {
  95         struct inode *inode = dentry->d_inode;
  96
  97         if ((attr->ia_valid & ATTR_SIZE) &&
  98             (attr->ia_size != inode->i_size))
  99                 return -EINVAL;
 100         return inode_setattr(inode, attr);
 101 }
 102
 103
 104 static int
 105 spufs_new_file(struct super_block *sb, struct dentry *dentry,
 106                 const struct file_operations *fops, int mode,
 107                 struct spu_context *ctx)
 108 {
 109         static struct inode_operations spufs_file_iops = {
 110                 .setattr = spufs_setattr,
 111         };
 112         struct inode *inode;
 113         int ret;
 114
 115         ret = -ENOSPC;
 116         inode = spufs_new_inode(sb, S_IFREG | mode);
 117         if (!inode)
 118                 goto out;
 119
 120         ret = 0;
 121         inode->i_op = &spufs_file_iops;
 122         inode->i_fop = fops;
 123         inode->i_private = SPUFS_I(inode)->i_ctx = get_spu_context(ctx);
 124         d_add(dentry, inode);
 125 out:
 126         return ret;
 127 }
 128
 129 static void
 130 spufs_delete_inode(struct inode *inode)
 131 {
 132         if (SPUFS_I(inode)->i_ctx)
 133                 put_spu_context(SPUFS_I(inode)->i_ctx);
 134         clear_inode(inode);
 135 }
 136
 137 static void spufs_prune_dir(struct dentry *dir)
 138 {
 139         struct dentry *dentry, *tmp;
 140         mutex_lock(&dir->d_inode->i_mutex);
 141         list_for_each_entry_safe(dentry, tmp, &dir->d_subdirs, d_u.d_child) {
 142                 spin_lock(&dcache_lock);
 143                 spin_lock(&dentry->d_lock);
 144                 if (!(d_unhashed(dentry)) && dentry->d_inode) {
 145                         dget_locked(dentry);
 146                         __d_drop(dentry);
 147                         spin_unlock(&dentry->d_lock);
 148                         simple_unlink(dir->d_inode, dentry);
 149                         spin_unlock(&dcache_lock);
 150                         dput(dentry);
 151                 } else {
 152                         spin_unlock(&dentry->d_lock);
 153                         spin_unlock(&dcache_lock);
 154                 }
 155         }
 156         shrink_dcache_parent(dir);
 157         mutex_unlock(&dir->d_inode->i_mutex);
 158 }
 159
 160 /* Caller must hold root->i_mutex */
 161 static int spufs_rmdir(struct inode *root, struct dentry *dir_dentry)
 162 {
 163         /* remove all entries */
 164         spufs_prune_dir(dir_dentry);
 165
 166         return simple_rmdir(root, dir_dentry);
 167 }
 168
 169 static int spufs_fill_dir(struct dentry *dir, struct tree_descr *files,
 170                           int mode, struct spu_context *ctx)
 171 {
 172         struct dentry *dentry;
 173         int ret;
 174
 175         while (files->name && files->name[0]) {
 176                 ret = -ENOMEM;
 177                 dentry = d_alloc_name(dir, files->name);
 178                 if (!dentry)
 179                         goto out;
 180                 ret = spufs_new_file(dir->d_sb, dentry, files->ops,
 181                                         files->mode & mode, ctx);
 182                 if (ret)
 183                         goto out;
 184                 files++;
 185         }
 186         return 0;
 187 out:
 188         spufs_prune_dir(dir);
 189         return ret;
 190 }
 191
 192 static int spufs_dir_close(struct inode *inode, struct file *file)
 193 {
 194         struct spu_context *ctx;
 195         struct inode *dir;
 196         struct dentry *dentry;
 197         int ret;
 198
 199         dentry = file->f_dentry;
 200         dir = dentry->d_parent->d_inode;
 201         ctx = SPUFS_I(dentry->d_inode)->i_ctx;
 202
 203         mutex_lock(&dir->i_mutex);
 204         ret = spufs_rmdir(dir, dentry);
 205         mutex_unlock(&dir->i_mutex);
 206         WARN_ON(ret);
 207
 208         /* We have to give up the mm_struct */
 209         spu_forget(ctx);
 210
 211         return dcache_dir_close(inode, file);
 212 }
 213
 214 struct inode_operations spufs_dir_inode_operations = {
 215         .lookup = simple_lookup,
 216 };
 217
 218 struct file_operations spufs_context_fops = {
 219         .open           = dcache_dir_open,
 220         .release        = spufs_dir_close,
 221         .llseek         = dcache_dir_lseek,
 222         .read           = generic_read_dir,
 223         .readdir        = dcache_readdir,
 224         .fsync          = simple_sync_file,
 225 };
 226
 227 static int
 228 spufs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 229 {
 230         int ret;
 231         struct inode *inode;
 232         struct spu_context *ctx;
 233
 234         ret = -ENOSPC;
 235         inode = spufs_new_inode(dir->i_sb, mode | S_IFDIR);
 236         if (!inode)
 237                 goto out;
 238
 239         if (dir->i_mode & S_ISGID) {
 240                 inode->i_gid = dir->i_gid;
 241                 inode->i_mode &= S_ISGID;
 242         }
 243         ctx = alloc_spu_context();
 244         SPUFS_I(inode)->i_ctx = ctx;
 245         if (!ctx)
 246                 goto out_iput;
 247
 248         inode->i_op = &spufs_dir_inode_operations;
 249         inode->i_fop = &simple_dir_operations;
 250         ret = spufs_fill_dir(dentry, spufs_dir_contents, mode, ctx);
 251         if (ret)
 252                 goto out_free_ctx;
 253
 254         d_instantiate(dentry, inode);
 255         dget(dentry);
 256         dir->i_nlink++;
 257         dentry->d_inode->i_nlink++;
 258         goto out;
 259
 260 out_free_ctx:
 261         put_spu_context(ctx);
 262 out_iput:
 263         iput(inode);
 264 out:
 265         return ret;
 266 }
 267
 268 static int spufs_context_open(struct dentry *dentry, struct vfsmount *mnt)
 269 {
 270         int ret;
 271         struct file *filp;
 272
 273         ret = get_unused_fd();
 274         if (ret < 0) {
 275                 dput(dentry);
 276                 mntput(mnt);
 277                 goto out;
 278         }
 279
 280         filp = dentry_open(dentry, mnt, O_RDONLY);
 281         if (IS_ERR(filp)) {
 282                 put_unused_fd(ret);
 283                 ret = PTR_ERR(filp);
 284                 goto out;
 285         }
 286
 287         filp->f_op = &spufs_context_fops;
 288         fd_install(ret, filp);
 289 out:
 290         return ret;
 291 }
 292
 293 static struct file_system_type spufs_type;
 294
 295 long spufs_create_thread(struct nameidata *nd,
 296                          unsigned int flags, mode_t mode)
 297 {
 298         struct dentry *dentry;
 299         int ret;
 300
 301         /* need to be at the root of spufs */
 302         ret = -EINVAL;
 303         if (nd->dentry->d_sb->s_type != &spufs_type ||
 304             nd->dentry != nd->dentry->d_sb->s_root)
 305                 goto out;
 306
 307         /* all flags are reserved */
 308         if (flags)
 309                 goto out;
 310
 311         dentry = lookup_create(nd, 1);
 312         ret = PTR_ERR(dentry);
 313         if (IS_ERR(dentry))
 314                 goto out_dir;
 315
 316         ret = -EEXIST;
 317         if (dentry->d_inode)
 318                 goto out_dput;
 319
 320         mode &= ~current->fs->umask;
 321         ret = spufs_mkdir(nd->dentry->d_inode, dentry, mode & S_IRWXUGO);
 322         if (ret)
 323                 goto out_dput;
 324
 325         /*
 326          * get references for dget and mntget, will be released
 327          * in error path of *_open().
 328          */
 329         ret = spufs_context_open(dget(dentry), mntget(nd->mnt));
 330         if (ret < 0) {
 331                 WARN_ON(spufs_rmdir(nd->dentry->d_inode, dentry));
 332                 mutex_unlock(&nd->dentry->d_inode->i_mutex);
 333                 spu_forget(SPUFS_I(dentry->d_inode)->i_ctx);
 334                 dput(dentry);
 335                 goto out;
 336         }
 337
 338 out_dput:
 339         dput(dentry);
 340 out_dir:
 341         mutex_unlock(&nd->dentry->d_inode->i_mutex);
 342 out:
 343         return ret;
 344 }
 345
 346 /* File system initialization */
 347 enum {
 348         Opt_uid, Opt_gid, Opt_err,
 349 };
 350
 351 static match_table_t spufs_tokens = {
 352         { Opt_uid, "uid=%d" },
 353         { Opt_gid, "gid=%d" },
 354         { Opt_err, NULL  },
 355 };
 356
 357 static int
 358 spufs_parse_options(char *options, struct inode *root)
 359 {
 360         char *p;
 361         substring_t args[MAX_OPT_ARGS];
 362
 363         while ((p = strsep(&options, ",")) != NULL) {
 364                 int token, option;
 365
 366                 if (!*p)
 367                         continue;
 368
 369                 token = match_token(p, spufs_tokens, args);
 370                 switch (token) {
 371                 case Opt_uid:
 372                         if (match_int(&args[0], &option))
 373                                 return 0;
 374                         root->i_uid = option;
 375                         break;
 376                 case Opt_gid:
 377                         if (match_int(&args[0], &option))
 378                                 return 0;
 379                         root->i_gid = option;
 380                         break;
 381                 default:
 382                         return 0;
 383                 }
 384         }
 385         return 1;
 386 }
 387
 388 static int
 389 spufs_create_root(struct super_block *sb, void *data)
 390 {
 391         struct inode *inode;
 392         int ret;
 393
 394         ret = -ENOMEM;
 395         inode = spufs_new_inode(sb, S_IFDIR | 0775);
 396         if (!inode)
 397                 goto out;
 398
 399         inode->i_op = &spufs_dir_inode_operations;
 400         inode->i_fop = &simple_dir_operations;
 401         SPUFS_I(inode)->i_ctx = NULL;
 402
 403         ret = -EINVAL;
 404         if (!spufs_parse_options(data, inode))
 405                 goto out_iput;
 406
 407         ret = -ENOMEM;
 408         sb->s_root = d_alloc_root(inode);
 409         if (!sb->s_root)
 410                 goto out_iput;
 411
 412         return 0;
 413 out_iput:
 414         iput(inode);
 415 out:
 416         return ret;
 417 }
 418
 419 static int
 420 spufs_fill_super(struct super_block *sb, void *data, int silent)
 421 {
 422         static struct super_operations s_ops = {
 423                 .alloc_inode = spufs_alloc_inode,
 424                 .destroy_inode = spufs_destroy_inode,
 425                 .statfs = simple_statfs,
 426                 .delete_inode = spufs_delete_inode,
 427                 .drop_inode = generic_delete_inode,
 428         };
 429
 430         sb->s_maxbytes = MAX_LFS_FILESIZE;
 431         sb->s_blocksize = PAGE_CACHE_SIZE;
 432         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 433         sb->s_magic = SPUFS_MAGIC;
 434         sb->s_op = &s_ops;
 435
 436         return spufs_create_root(sb, data);
 437 }
 438
 439 static int
 440 spufs_get_sb(struct file_system_type *fstype, int flags,
 441                 const char *name, void *data, struct vfsmount *mnt)
 442 {
 443         return get_sb_single(fstype, flags, data, spufs_fill_super, mnt);
 444 }
 445
 446 static struct file_system_type spufs_type = {
 447         .owner = THIS_MODULE,
 448         .name = "spufs",
 449         .get_sb = spufs_get_sb,
 450         .kill_sb = kill_litter_super,
 451 };
 452
 453 static int __init spufs_init(void)
 454 {
 455         int ret;
 456         ret = -ENOMEM;
 457         spufs_inode_cache = kmem_cache_create("spufs_inode_cache",
 458                         sizeof(struct spufs_inode_info), 0,
 459                         SLAB_HWCACHE_ALIGN, spufs_init_once, NULL);
 460
 461         if (!spufs_inode_cache)
 462                 goto out;
 463         if (spu_sched_init() != 0) {
 464                 kmem_cache_destroy(spufs_inode_cache);
 465                 goto out;
 466         }
 467         ret = register_filesystem(&spufs_type);
 468         if (ret)
 469                 goto out_cache;
 470         ret = register_spu_syscalls(&spufs_calls);
 471         if (ret)
 472                 goto out_fs;
 473         return 0;
 474 out_fs:
 475         unregister_filesystem(&spufs_type);
 476 out_cache:
 477         kmem_cache_destroy(spufs_inode_cache);
 478 out:
 479         return ret;
 480 }
 481 module_init(spufs_init);
 482
 483 static void __exit spufs_exit(void)
 484 {
 485         spu_sched_exit();
 486         unregister_spu_syscalls(&spufs_calls);
 487         unregister_filesystem(&spufs_type);
 488         kmem_cache_destroy(spufs_inode_cache);
 489 }
 490 module_exit(spufs_exit);
 491
 492 MODULE_LICENSE("GPL");
 493 MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
 494