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