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                 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->u.generic_ip = 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 static int spufs_rmdir(struct inode *root, struct dentry *dir_dentry)
 161 {
 162         struct spu_context *ctx;
 163
 164         /* remove all entries */
 165         mutex_lock(&root->i_mutex);
 166         spufs_prune_dir(dir_dentry);
 167         mutex_unlock(&root->i_mutex);
 168
 169         /* We have to give up the mm_struct */
 170         ctx = SPUFS_I(dir_dentry->d_inode)->i_ctx;
 171         spu_forget(ctx);
 172
 173         /* XXX Do we need to hold i_mutex here ? */
 174         return simple_rmdir(root, dir_dentry);
 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 inode *dir;
 203         struct dentry *dentry;
 204         int ret;
 205
 206         dentry = file->f_dentry;
 207         dir = dentry->d_parent->d_inode;
 208
 209         ret = spufs_rmdir(dir, dentry);
 210         WARN_ON(ret);
 211
 212         return dcache_dir_close(inode, file);
 213 }
 214
 215 struct inode_operations spufs_dir_inode_operations = {
 216         .lookup = simple_lookup,
 217 };
 218
 219 struct file_operations spufs_context_fops = {
 220         .open           = dcache_dir_open,
 221         .release        = spufs_dir_close,
 222         .llseek         = dcache_dir_lseek,
 223         .read           = generic_read_dir,
 224         .readdir        = dcache_readdir,
 225         .fsync          = simple_sync_file,
 226 };
 227
 228 static int
 229 spufs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 230 {
 231         int ret;
 232         struct inode *inode;
 233         struct spu_context *ctx;
 234
 235         ret = -ENOSPC;
 236         inode = spufs_new_inode(dir->i_sb, mode | S_IFDIR);
 237         if (!inode)
 238                 goto out;
 239
 240         if (dir->i_mode & S_ISGID) {
 241                 inode->i_gid = dir->i_gid;
 242                 inode->i_mode &= S_ISGID;
 243         }
 244         ctx = alloc_spu_context();
 245         SPUFS_I(inode)->i_ctx = ctx;
 246         if (!ctx)
 247                 goto out_iput;
 248
 249         inode->i_op = &spufs_dir_inode_operations;
 250         inode->i_fop = &simple_dir_operations;
 251         ret = spufs_fill_dir(dentry, spufs_dir_contents, mode, ctx);
 252         if (ret)
 253                 goto out_free_ctx;
 254
 255         d_instantiate(dentry, inode);
 256         dget(dentry);
 257         dir->i_nlink++;
 258         dentry->d_inode->i_nlink++;
 259         goto out;
 260
 261 out_free_ctx:
 262         put_spu_context(ctx);
 263 out_iput:
 264         iput(inode);
 265 out:
 266         return ret;
 267 }
 268
 269 static int spufs_context_open(struct dentry *dentry, struct vfsmount *mnt)
 270 {
 271         int ret;
 272         struct file *filp;
 273
 274         ret = get_unused_fd();
 275         if (ret < 0) {
 276                 dput(dentry);
 277                 mntput(mnt);
 278                 goto out;
 279         }
 280
 281         filp = dentry_open(dentry, mnt, O_RDONLY);
 282         if (IS_ERR(filp)) {
 283                 put_unused_fd(ret);
 284                 ret = PTR_ERR(filp);
 285                 goto out;
 286         }
 287
 288         filp->f_op = &spufs_context_fops;
 289         fd_install(ret, filp);
 290 out:
 291         return ret;
 292 }
 293
 294 static struct file_system_type spufs_type;
 295
 296 long spufs_create_thread(struct nameidata *nd,
 297                          unsigned int flags, mode_t mode)
 298 {
 299         struct dentry *dentry;
 300         int ret;
 301
 302         /* need to be at the root of spufs */
 303         ret = -EINVAL;
 304         if (nd->dentry->d_sb->s_type != &spufs_type ||
 305             nd->dentry != nd->dentry->d_sb->s_root)
 306                 goto out;
 307
 308         dentry = lookup_create(nd, 1);
 309         ret = PTR_ERR(dentry);
 310         if (IS_ERR(dentry))
 311                 goto out_dir;
 312
 313         ret = -EEXIST;
 314         if (dentry->d_inode)
 315                 goto out_dput;
 316
 317         mode &= ~current->fs->umask;
 318         ret = spufs_mkdir(nd->dentry->d_inode, dentry, mode & S_IRWXUGO);
 319         if (ret)
 320                 goto out_dput;
 321
 322         /*
 323          * get references for dget and mntget, will be released
 324          * in error path of *_open().
 325          */
 326         ret = spufs_context_open(dget(dentry), mntget(nd->mnt));
 327         if (ret < 0)
 328                 spufs_rmdir(nd->dentry->d_inode, dentry);
 329
 330 out_dput:
 331         dput(dentry);
 332 out_dir:
 333         mutex_unlock(&nd->dentry->d_inode->i_mutex);
 334 out:
 335         return ret;
 336 }
 337
 338 /* File system initialization */
 339 enum {
 340         Opt_uid, Opt_gid, Opt_err,
 341 };
 342
 343 static match_table_t spufs_tokens = {
 344         { Opt_uid, "uid=%d" },
 345         { Opt_gid, "gid=%d" },
 346         { Opt_err, NULL  },
 347 };
 348
 349 static int
 350 spufs_parse_options(char *options, struct inode *root)
 351 {
 352         char *p;
 353         substring_t args[MAX_OPT_ARGS];
 354
 355         while ((p = strsep(&options, ",")) != NULL) {
 356                 int token, option;
 357
 358                 if (!*p)
 359                         continue;
 360
 361                 token = match_token(p, spufs_tokens, args);
 362                 switch (token) {
 363                 case Opt_uid:
 364                         if (match_int(&args[0], &option))
 365                                 return 0;
 366                         root->i_uid = option;
 367                         break;
 368                 case Opt_gid:
 369                         if (match_int(&args[0], &option))
 370                                 return 0;
 371                         root->i_gid = option;
 372                         break;
 373                 default:
 374                         return 0;
 375                 }
 376         }
 377         return 1;
 378 }
 379
 380 static int
 381 spufs_create_root(struct super_block *sb, void *data)
 382 {
 383         struct inode *inode;
 384         int ret;
 385
 386         ret = -ENOMEM;
 387         inode = spufs_new_inode(sb, S_IFDIR | 0775);
 388         if (!inode)
 389                 goto out;
 390
 391         inode->i_op = &spufs_dir_inode_operations;
 392         inode->i_fop = &simple_dir_operations;
 393         SPUFS_I(inode)->i_ctx = NULL;
 394
 395         ret = -EINVAL;
 396         if (!spufs_parse_options(data, inode))
 397                 goto out_iput;
 398
 399         ret = -ENOMEM;
 400         sb->s_root = d_alloc_root(inode);
 401         if (!sb->s_root)
 402                 goto out_iput;
 403
 404         return 0;
 405 out_iput:
 406         iput(inode);
 407 out:
 408         return ret;
 409 }
 410
 411 static int
 412 spufs_fill_super(struct super_block *sb, void *data, int silent)
 413 {
 414         static struct super_operations s_ops = {
 415                 .alloc_inode = spufs_alloc_inode,
 416                 .destroy_inode = spufs_destroy_inode,
 417                 .statfs = simple_statfs,
 418                 .delete_inode = spufs_delete_inode,
 419                 .drop_inode = generic_delete_inode,
 420         };
 421
 422         sb->s_maxbytes = MAX_LFS_FILESIZE;
 423         sb->s_blocksize = PAGE_CACHE_SIZE;
 424         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 425         sb->s_magic = SPUFS_MAGIC;
 426         sb->s_op = &s_ops;
 427
 428         return spufs_create_root(sb, data);
 429 }
 430
 431 static struct super_block *
 432 spufs_get_sb(struct file_system_type *fstype, int flags,
 433                 const char *name, void *data)
 434 {
 435         return get_sb_single(fstype, flags, data, spufs_fill_super);
 436 }
 437
 438 static struct file_system_type spufs_type = {
 439         .owner = THIS_MODULE,
 440         .name = "spufs",
 441         .get_sb = spufs_get_sb,
 442         .kill_sb = kill_litter_super,
 443 };
 444
 445 static int spufs_init(void)
 446 {
 447         int ret;
 448         ret = -ENOMEM;
 449         spufs_inode_cache = kmem_cache_create("spufs_inode_cache",
 450                         sizeof(struct spufs_inode_info), 0,
 451                         SLAB_HWCACHE_ALIGN, spufs_init_once, NULL);
 452
 453         if (!spufs_inode_cache)
 454                 goto out;
 455         if (spu_sched_init() != 0) {
 456                 kmem_cache_destroy(spufs_inode_cache);
 457                 goto out;
 458         }
 459         ret = register_filesystem(&spufs_type);
 460         if (ret)
 461                 goto out_cache;
 462         ret = register_spu_syscalls(&spufs_calls);
 463         if (ret)
 464                 goto out_fs;
 465         return 0;
 466 out_fs:
 467         unregister_filesystem(&spufs_type);
 468 out_cache:
 469         kmem_cache_destroy(spufs_inode_cache);
 470 out:
 471         return ret;
 472 }
 473 module_init(spufs_init);
 474
 475 static void spufs_exit(void)
 476 {
 477         spu_sched_exit();
 478         unregister_spu_syscalls(&spufs_calls);
 479         unregister_filesystem(&spufs_type);
 480         kmem_cache_destroy(spufs_inode_cache);
 481 }
 482 module_exit(spufs_exit);
 483
 484 MODULE_LICENSE("GPL");
 485 MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
 486