fs/nilfs2/ioctl.c

   1 /*
   2  * ioctl.c - NILFS ioctl operations.
   3  *
   4  * Copyright (C) 2007, 2008 Nippon Telegraph and Telephone Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  * Written by Koji Sato <koji@osrg.net>.
  21  */
  22
  23 #include <linux/fs.h>
  24 #include <linux/wait.h>
  25 #include <linux/smp_lock.h>     /* lock_kernel(), unlock_kernel() */
  26 #include <linux/slab.h>
  27 #include <linux/capability.h>   /* capable() */
  28 #include <linux/uaccess.h>      /* copy_from_user(), copy_to_user() */
  29 #include <linux/vmalloc.h>
  30 #include <linux/mount.h>        /* mnt_want_write(), mnt_drop_write() */
  31 #include <linux/nilfs2_fs.h>
  32 #include "nilfs.h"
  33 #include "segment.h"
  34 #include "bmap.h"
  35 #include "cpfile.h"
  36 #include "sufile.h"
  37 #include "dat.h"
  38
  39
  40 static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
  41                                  struct nilfs_argv *argv, int dir,
  42                                  ssize_t (*dofunc)(struct the_nilfs *,
  43                                                    __u64 *, int,
  44                                                    void *, size_t, size_t))
  45 {
  46         void *buf;
  47         void __user *base = (void __user *)(unsigned long)argv->v_base;
  48         size_t maxmembs, total, n;
  49         ssize_t nr;
  50         int ret, i;
  51         __u64 pos, ppos;
  52
  53         if (argv->v_nmembs == 0)
  54                 return 0;
  55
  56         if (argv->v_size > PAGE_SIZE)
  57                 return -EINVAL;
  58
  59         buf = (void *)__get_free_pages(GFP_NOFS, 0);
  60         if (unlikely(!buf))
  61                 return -ENOMEM;
  62         maxmembs = PAGE_SIZE / argv->v_size;
  63
  64         ret = 0;
  65         total = 0;
  66         pos = argv->v_index;
  67         for (i = 0; i < argv->v_nmembs; i += n) {
  68                 n = (argv->v_nmembs - i < maxmembs) ?
  69                         argv->v_nmembs - i : maxmembs;
  70                 if ((dir & _IOC_WRITE) &&
  71                     copy_from_user(buf, base + argv->v_size * i,
  72                                    argv->v_size * n)) {
  73                         ret = -EFAULT;
  74                         break;
  75                 }
  76                 ppos = pos;
  77                 nr = dofunc(nilfs, &pos, argv->v_flags, buf, argv->v_size,
  78                                n);
  79                 if (nr < 0) {
  80                         ret = nr;
  81                         break;
  82                 }
  83                 if ((dir & _IOC_READ) &&
  84                     copy_to_user(base + argv->v_size * i, buf,
  85                                  argv->v_size * nr)) {
  86                         ret = -EFAULT;
  87                         break;
  88                 }
  89                 total += nr;
  90                 if ((size_t)nr < n)
  91                         break;
  92                 if (pos == ppos)
  93                         pos += n;
  94         }
  95         argv->v_nmembs = total;
  96
  97         free_pages((unsigned long)buf, 0);
  98         return ret;
  99 }
 100
 101 static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
 102                                      unsigned int cmd, void __user *argp)
 103 {
 104         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 105         struct inode *cpfile = nilfs->ns_cpfile;
 106         struct nilfs_transaction_info ti;
 107         struct nilfs_cpmode cpmode;
 108         int ret;
 109
 110         if (!capable(CAP_SYS_ADMIN))
 111                 return -EPERM;
 112
 113         ret = mnt_want_write(filp->f_path.mnt);
 114         if (ret)
 115                 return ret;
 116
 117         ret = -EFAULT;
 118         if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
 119                 goto out;
 120
 121         mutex_lock(&nilfs->ns_mount_mutex);
 122
 123         nilfs_transaction_begin(inode->i_sb, &ti, 0);
 124         ret = nilfs_cpfile_change_cpmode(
 125                 cpfile, cpmode.cm_cno, cpmode.cm_mode);
 126         if (unlikely(ret < 0))
 127                 nilfs_transaction_abort(inode->i_sb);
 128         else
 129                 nilfs_transaction_commit(inode->i_sb); /* never fails */
 130
 131         mutex_unlock(&nilfs->ns_mount_mutex);
 132 out:
 133         mnt_drop_write(filp->f_path.mnt);
 134         return ret;
 135 }
 136
 137 static int
 138 nilfs_ioctl_delete_checkpoint(struct inode *inode, struct file *filp,
 139                               unsigned int cmd, void __user *argp)
 140 {
 141         struct inode *cpfile = NILFS_SB(inode->i_sb)->s_nilfs->ns_cpfile;
 142         struct nilfs_transaction_info ti;
 143         __u64 cno;
 144         int ret;
 145
 146         if (!capable(CAP_SYS_ADMIN))
 147                 return -EPERM;
 148
 149         ret = mnt_want_write(filp->f_path.mnt);
 150         if (ret)
 151                 return ret;
 152
 153         ret = -EFAULT;
 154         if (copy_from_user(&cno, argp, sizeof(cno)))
 155                 goto out;
 156
 157         nilfs_transaction_begin(inode->i_sb, &ti, 0);
 158         ret = nilfs_cpfile_delete_checkpoint(cpfile, cno);
 159         if (unlikely(ret < 0))
 160                 nilfs_transaction_abort(inode->i_sb);
 161         else
 162                 nilfs_transaction_commit(inode->i_sb); /* never fails */
 163 out:
 164         mnt_drop_write(filp->f_path.mnt);
 165         return ret;
 166 }
 167
 168 static ssize_t
 169 nilfs_ioctl_do_get_cpinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
 170                           void *buf, size_t size, size_t nmembs)
 171 {
 172         int ret;
 173
 174         down_read(&nilfs->ns_segctor_sem);
 175         ret = nilfs_cpfile_get_cpinfo(nilfs->ns_cpfile, posp, flags, buf,
 176                                       size, nmembs);
 177         up_read(&nilfs->ns_segctor_sem);
 178         return ret;
 179 }
 180
 181 static int nilfs_ioctl_get_cpstat(struct inode *inode, struct file *filp,
 182                                   unsigned int cmd, void __user *argp)
 183 {
 184         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 185         struct nilfs_cpstat cpstat;
 186         int ret;
 187
 188         down_read(&nilfs->ns_segctor_sem);
 189         ret = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
 190         up_read(&nilfs->ns_segctor_sem);
 191         if (ret < 0)
 192                 return ret;
 193
 194         if (copy_to_user(argp, &cpstat, sizeof(cpstat)))
 195                 ret = -EFAULT;
 196         return ret;
 197 }
 198
 199 static ssize_t
 200 nilfs_ioctl_do_get_suinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
 201                           void *buf, size_t size, size_t nmembs)
 202 {
 203         int ret;
 204
 205         down_read(&nilfs->ns_segctor_sem);
 206         ret = nilfs_sufile_get_suinfo(nilfs->ns_sufile, *posp, buf, size,
 207                                       nmembs);
 208         up_read(&nilfs->ns_segctor_sem);
 209         return ret;
 210 }
 211
 212 static int nilfs_ioctl_get_sustat(struct inode *inode, struct file *filp,
 213                                   unsigned int cmd, void __user *argp)
 214 {
 215         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 216         struct nilfs_sustat sustat;
 217         int ret;
 218
 219         down_read(&nilfs->ns_segctor_sem);
 220         ret = nilfs_sufile_get_stat(nilfs->ns_sufile, &sustat);
 221         up_read(&nilfs->ns_segctor_sem);
 222         if (ret < 0)
 223                 return ret;
 224
 225         if (copy_to_user(argp, &sustat, sizeof(sustat)))
 226                 ret = -EFAULT;
 227         return ret;
 228 }
 229
 230 static ssize_t
 231 nilfs_ioctl_do_get_vinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
 232                          void *buf, size_t size, size_t nmembs)
 233 {
 234         int ret;
 235
 236         down_read(&nilfs->ns_segctor_sem);
 237         ret = nilfs_dat_get_vinfo(nilfs_dat_inode(nilfs), buf, size, nmembs);
 238         up_read(&nilfs->ns_segctor_sem);
 239         return ret;
 240 }
 241
 242 static ssize_t
 243 nilfs_ioctl_do_get_bdescs(struct the_nilfs *nilfs, __u64 *posp, int flags,
 244                           void *buf, size_t size, size_t nmembs)
 245 {
 246         struct inode *dat = nilfs_dat_inode(nilfs);
 247         struct nilfs_bmap *bmap = NILFS_I(dat)->i_bmap;
 248         struct nilfs_bdesc *bdescs = buf;
 249         int ret, i;
 250
 251         down_read(&nilfs->ns_segctor_sem);
 252         for (i = 0; i < nmembs; i++) {
 253                 ret = nilfs_bmap_lookup_at_level(bmap,
 254                                                  bdescs[i].bd_offset,
 255                                                  bdescs[i].bd_level + 1,
 256                                                  &bdescs[i].bd_blocknr);
 257                 if (ret < 0) {
 258                         if (ret != -ENOENT) {
 259                                 up_read(&nilfs->ns_segctor_sem);
 260                                 return ret;
 261                         }
 262                         bdescs[i].bd_blocknr = 0;
 263                 }
 264         }
 265         up_read(&nilfs->ns_segctor_sem);
 266         return nmembs;
 267 }
 268
 269 static int nilfs_ioctl_get_bdescs(struct inode *inode, struct file *filp,
 270                                   unsigned int cmd, void __user *argp)
 271 {
 272         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 273         struct nilfs_argv argv;
 274         int ret;
 275
 276         if (copy_from_user(&argv, argp, sizeof(argv)))
 277                 return -EFAULT;
 278
 279         if (argv.v_size != sizeof(struct nilfs_bdesc))
 280                 return -EINVAL;
 281
 282         ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd),
 283                                     nilfs_ioctl_do_get_bdescs);
 284         if (ret < 0)
 285                 return ret;
 286
 287         if (copy_to_user(argp, &argv, sizeof(argv)))
 288                 ret = -EFAULT;
 289         return ret;
 290 }
 291
 292 static int nilfs_ioctl_move_inode_block(struct inode *inode,
 293                                         struct nilfs_vdesc *vdesc,
 294                                         struct list_head *buffers)
 295 {
 296         struct buffer_head *bh;
 297         int ret;
 298
 299         if (vdesc->vd_flags == 0)
 300                 ret = nilfs_gccache_submit_read_data(
 301                         inode, vdesc->vd_offset, vdesc->vd_blocknr,
 302                         vdesc->vd_vblocknr, &bh);
 303         else
 304                 ret = nilfs_gccache_submit_read_node(
 305                         inode, vdesc->vd_blocknr, vdesc->vd_vblocknr, &bh);
 306
 307         if (unlikely(ret < 0)) {
 308                 if (ret == -ENOENT)
 309                         printk(KERN_CRIT
 310                                "%s: invalid virtual block address (%s): "
 311                                "ino=%llu, cno=%llu, offset=%llu, "
 312                                "blocknr=%llu, vblocknr=%llu\n",
 313                                __func__, vdesc->vd_flags ? "node" : "data",
 314                                (unsigned long long)vdesc->vd_ino,
 315                                (unsigned long long)vdesc->vd_cno,
 316                                (unsigned long long)vdesc->vd_offset,
 317                                (unsigned long long)vdesc->vd_blocknr,
 318                                (unsigned long long)vdesc->vd_vblocknr);
 319                 return ret;
 320         }
 321         if (unlikely(!list_empty(&bh->b_assoc_buffers))) {
 322                 printk(KERN_CRIT "%s: conflicting %s buffer: ino=%llu, "
 323                        "cno=%llu, offset=%llu, blocknr=%llu, vblocknr=%llu\n",
 324                        __func__, vdesc->vd_flags ? "node" : "data",
 325                        (unsigned long long)vdesc->vd_ino,
 326                        (unsigned long long)vdesc->vd_cno,
 327                        (unsigned long long)vdesc->vd_offset,
 328                        (unsigned long long)vdesc->vd_blocknr,
 329                        (unsigned long long)vdesc->vd_vblocknr);
 330                 brelse(bh);
 331                 return -EEXIST;
 332         }
 333         list_add_tail(&bh->b_assoc_buffers, buffers);
 334         return 0;
 335 }
 336
 337 static int nilfs_ioctl_move_blocks(struct the_nilfs *nilfs,
 338                                    struct nilfs_argv *argv, void *buf)
 339 {
 340         size_t nmembs = argv->v_nmembs;
 341         struct inode *inode;
 342         struct nilfs_vdesc *vdesc;
 343         struct buffer_head *bh, *n;
 344         LIST_HEAD(buffers);
 345         ino_t ino;
 346         __u64 cno;
 347         int i, ret;
 348
 349         for (i = 0, vdesc = buf; i < nmembs; ) {
 350                 ino = vdesc->vd_ino;
 351                 cno = vdesc->vd_cno;
 352                 inode = nilfs_gc_iget(nilfs, ino, cno);
 353                 if (unlikely(inode == NULL)) {
 354                         ret = -ENOMEM;
 355                         goto failed;
 356                 }
 357                 do {
 358                         ret = nilfs_ioctl_move_inode_block(inode, vdesc,
 359                                                            &buffers);
 360                         if (unlikely(ret < 0))
 361                                 goto failed;
 362                         vdesc++;
 363                 } while (++i < nmembs &&
 364                          vdesc->vd_ino == ino && vdesc->vd_cno == cno);
 365         }
 366
 367         list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
 368                 ret = nilfs_gccache_wait_and_mark_dirty(bh);
 369                 if (unlikely(ret < 0)) {
 370                         WARN_ON(ret == -EEXIST);
 371                         goto failed;
 372                 }
 373                 list_del_init(&bh->b_assoc_buffers);
 374                 brelse(bh);
 375         }
 376         return nmembs;
 377
 378  failed:
 379         list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
 380                 list_del_init(&bh->b_assoc_buffers);
 381                 brelse(bh);
 382         }
 383         return ret;
 384 }
 385
 386 static int nilfs_ioctl_delete_checkpoints(struct the_nilfs *nilfs,
 387                                           struct nilfs_argv *argv, void *buf)
 388 {
 389         size_t nmembs = argv->v_nmembs;
 390         struct inode *cpfile = nilfs->ns_cpfile;
 391         struct nilfs_period *periods = buf;
 392         int ret, i;
 393
 394         for (i = 0; i < nmembs; i++) {
 395                 ret = nilfs_cpfile_delete_checkpoints(
 396                         cpfile, periods[i].p_start, periods[i].p_end);
 397                 if (ret < 0)
 398                         return ret;
 399         }
 400         return nmembs;
 401 }
 402
 403 static int nilfs_ioctl_free_vblocknrs(struct the_nilfs *nilfs,
 404                                       struct nilfs_argv *argv, void *buf)
 405 {
 406         size_t nmembs = argv->v_nmembs;
 407         int ret;
 408
 409         ret = nilfs_dat_freev(nilfs_dat_inode(nilfs), buf, nmembs);
 410
 411         return (ret < 0) ? ret : nmembs;
 412 }
 413
 414 static int nilfs_ioctl_mark_blocks_dirty(struct the_nilfs *nilfs,
 415                                          struct nilfs_argv *argv, void *buf)
 416 {
 417         size_t nmembs = argv->v_nmembs;
 418         struct inode *dat = nilfs_dat_inode(nilfs);
 419         struct nilfs_bmap *bmap = NILFS_I(dat)->i_bmap;
 420         struct nilfs_bdesc *bdescs = buf;
 421         int ret, i;
 422
 423         for (i = 0; i < nmembs; i++) {
 424                 /* XXX: use macro or inline func to check liveness */
 425                 ret = nilfs_bmap_lookup_at_level(bmap,
 426                                                  bdescs[i].bd_offset,
 427                                                  bdescs[i].bd_level + 1,
 428                                                  &bdescs[i].bd_blocknr);
 429                 if (ret < 0) {
 430                         if (ret != -ENOENT)
 431                                 return ret;
 432                         bdescs[i].bd_blocknr = 0;
 433                 }
 434                 if (bdescs[i].bd_blocknr != bdescs[i].bd_oblocknr)
 435                         /* skip dead block */
 436                         continue;
 437                 if (bdescs[i].bd_level == 0) {
 438                         ret = nilfs_mdt_mark_block_dirty(dat,
 439                                                          bdescs[i].bd_offset);
 440                         if (ret < 0) {
 441                                 WARN_ON(ret == -ENOENT);
 442                                 return ret;
 443                         }
 444                 } else {
 445                         ret = nilfs_bmap_mark(bmap, bdescs[i].bd_offset,
 446                                               bdescs[i].bd_level);
 447                         if (ret < 0) {
 448                                 WARN_ON(ret == -ENOENT);
 449                                 return ret;
 450                         }
 451                 }
 452         }
 453         return nmembs;
 454 }
 455
 456 int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *nilfs,
 457                                        struct nilfs_argv *argv, void **kbufs)
 458 {
 459         const char *msg;
 460         int ret;
 461
 462         ret = nilfs_ioctl_delete_checkpoints(nilfs, &argv[1], kbufs[1]);
 463         if (ret < 0) {
 464                 /*
 465                  * can safely abort because checkpoints can be removed
 466                  * independently.
 467                  */
 468                 msg = "cannot delete checkpoints";
 469                 goto failed;
 470         }
 471         ret = nilfs_ioctl_free_vblocknrs(nilfs, &argv[2], kbufs[2]);
 472         if (ret < 0) {
 473                 /*
 474                  * can safely abort because DAT file is updated atomically
 475                  * using a copy-on-write technique.
 476                  */
 477                 msg = "cannot delete virtual blocks from DAT file";
 478                 goto failed;
 479         }
 480         ret = nilfs_ioctl_mark_blocks_dirty(nilfs, &argv[3], kbufs[3]);
 481         if (ret < 0) {
 482                 /*
 483                  * can safely abort because the operation is nondestructive.
 484                  */
 485                 msg = "cannot mark copying blocks dirty";
 486                 goto failed;
 487         }
 488         return 0;
 489
 490  failed:
 491         printk(KERN_ERR "NILFS: GC failed during preparation: %s: err=%d\n",
 492                msg, ret);
 493         return ret;
 494 }
 495
 496 static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
 497                                       unsigned int cmd, void __user *argp)
 498 {
 499         struct nilfs_argv argv[5];
 500         static const size_t argsz[5] = {
 501                 sizeof(struct nilfs_vdesc),
 502                 sizeof(struct nilfs_period),
 503                 sizeof(__u64),
 504                 sizeof(struct nilfs_bdesc),
 505                 sizeof(__u64),
 506         };
 507         void __user *base;
 508         void *kbufs[5];
 509         struct the_nilfs *nilfs;
 510         size_t len, nsegs;
 511         int n, ret;
 512
 513         if (!capable(CAP_SYS_ADMIN))
 514                 return -EPERM;
 515
 516         ret = mnt_want_write(filp->f_path.mnt);
 517         if (ret)
 518                 return ret;
 519
 520         ret = -EFAULT;
 521         if (copy_from_user(argv, argp, sizeof(argv)))
 522                 goto out;
 523
 524         ret = -EINVAL;
 525         nsegs = argv[4].v_nmembs;
 526         if (argv[4].v_size != argsz[4])
 527                 goto out;
 528
 529         /*
 530          * argv[4] points to segment numbers this ioctl cleans.  We
 531          * use kmalloc() for its buffer because memory used for the
 532          * segment numbers is enough small.
 533          */
 534         kbufs[4] = memdup_user((void __user *)(unsigned long)argv[4].v_base,
 535                                nsegs * sizeof(__u64));
 536         if (IS_ERR(kbufs[4])) {
 537                 ret = PTR_ERR(kbufs[4]);
 538                 goto out;
 539         }
 540         nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 541
 542         for (n = 0; n < 4; n++) {
 543                 ret = -EINVAL;
 544                 if (argv[n].v_size != argsz[n])
 545                         goto out_free;
 546
 547                 if (argv[n].v_nmembs > nsegs * nilfs->ns_blocks_per_segment)
 548                         goto out_free;
 549
 550                 len = argv[n].v_size * argv[n].v_nmembs;
 551                 base = (void __user *)(unsigned long)argv[n].v_base;
 552                 if (len == 0) {
 553                         kbufs[n] = NULL;
 554                         continue;
 555                 }
 556
 557                 kbufs[n] = vmalloc(len);
 558                 if (!kbufs[n]) {
 559                         ret = -ENOMEM;
 560                         goto out_free;
 561                 }
 562                 if (copy_from_user(kbufs[n], base, len)) {
 563                         ret = -EFAULT;
 564                         vfree(kbufs[n]);
 565                         goto out_free;
 566                 }
 567         }
 568
 569         /*
 570          * nilfs_ioctl_move_blocks() will call nilfs_gc_iget(),
 571          * which will operates an inode list without blocking.
 572          * To protect the list from concurrent operations,
 573          * nilfs_ioctl_move_blocks should be atomic operation.
 574          */
 575         if (test_and_set_bit(THE_NILFS_GC_RUNNING, &nilfs->ns_flags)) {
 576                 ret = -EBUSY;
 577                 goto out_free;
 578         }
 579
 580         ret = nilfs_ioctl_move_blocks(nilfs, &argv[0], kbufs[0]);
 581         if (ret < 0)
 582                 printk(KERN_ERR "NILFS: GC failed during preparation: "
 583                         "cannot read source blocks: err=%d\n", ret);
 584         else
 585                 ret = nilfs_clean_segments(inode->i_sb, argv, kbufs);
 586
 587         if (ret < 0)
 588                 nilfs_remove_all_gcinode(nilfs);
 589         clear_nilfs_gc_running(nilfs);
 590
 591 out_free:
 592         while (--n >= 0)
 593                 vfree(kbufs[n]);
 594         kfree(kbufs[4]);
 595 out:
 596         mnt_drop_write(filp->f_path.mnt);
 597         return ret;
 598 }
 599
 600 static int nilfs_ioctl_sync(struct inode *inode, struct file *filp,
 601                             unsigned int cmd, void __user *argp)
 602 {
 603         __u64 cno;
 604         int ret;
 605         struct the_nilfs *nilfs;
 606
 607         ret = nilfs_construct_segment(inode->i_sb);
 608         if (ret < 0)
 609                 return ret;
 610
 611         if (argp != NULL) {
 612                 nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 613                 down_read(&nilfs->ns_segctor_sem);
 614                 cno = nilfs->ns_cno - 1;
 615                 up_read(&nilfs->ns_segctor_sem);
 616                 if (copy_to_user(argp, &cno, sizeof(cno)))
 617                         return -EFAULT;
 618         }
 619         return 0;
 620 }
 621
 622 static int nilfs_ioctl_get_info(struct inode *inode, struct file *filp,
 623                                 unsigned int cmd, void __user *argp,
 624                                 size_t membsz,
 625                                 ssize_t (*dofunc)(struct the_nilfs *,
 626                                                   __u64 *, int,
 627                                                   void *, size_t, size_t))
 628
 629 {
 630         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 631         struct nilfs_argv argv;
 632         int ret;
 633
 634         if (copy_from_user(&argv, argp, sizeof(argv)))
 635                 return -EFAULT;
 636
 637         if (argv.v_size < membsz)
 638                 return -EINVAL;
 639
 640         ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd), dofunc);
 641         if (ret < 0)
 642                 return ret;
 643
 644         if (copy_to_user(argp, &argv, sizeof(argv)))
 645                 ret = -EFAULT;
 646         return ret;
 647 }
 648
 649 long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 650 {
 651         struct inode *inode = filp->f_dentry->d_inode;
 652         void __user *argp = (void * __user *)arg;
 653
 654         switch (cmd) {
 655         case NILFS_IOCTL_CHANGE_CPMODE:
 656                 return nilfs_ioctl_change_cpmode(inode, filp, cmd, argp);
 657         case NILFS_IOCTL_DELETE_CHECKPOINT:
 658                 return nilfs_ioctl_delete_checkpoint(inode, filp, cmd, argp);
 659         case NILFS_IOCTL_GET_CPINFO:
 660                 return nilfs_ioctl_get_info(inode, filp, cmd, argp,
 661                                             sizeof(struct nilfs_cpinfo),
 662                                             nilfs_ioctl_do_get_cpinfo);
 663         case NILFS_IOCTL_GET_CPSTAT:
 664                 return nilfs_ioctl_get_cpstat(inode, filp, cmd, argp);
 665         case NILFS_IOCTL_GET_SUINFO:
 666                 return nilfs_ioctl_get_info(inode, filp, cmd, argp,
 667                                             sizeof(struct nilfs_suinfo),
 668                                             nilfs_ioctl_do_get_suinfo);
 669         case NILFS_IOCTL_GET_SUSTAT:
 670                 return nilfs_ioctl_get_sustat(inode, filp, cmd, argp);
 671         case NILFS_IOCTL_GET_VINFO:
 672                 return nilfs_ioctl_get_info(inode, filp, cmd, argp,
 673                                             sizeof(struct nilfs_vinfo),
 674                                             nilfs_ioctl_do_get_vinfo);
 675         case NILFS_IOCTL_GET_BDESCS:
 676                 return nilfs_ioctl_get_bdescs(inode, filp, cmd, argp);
 677         case NILFS_IOCTL_CLEAN_SEGMENTS:
 678                 return nilfs_ioctl_clean_segments(inode, filp, cmd, argp);
 679         case NILFS_IOCTL_SYNC:
 680                 return nilfs_ioctl_sync(inode, filp, cmd, argp);
 681         default:
 682                 return -ENOTTY;
 683         }
 684 }