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