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/slab.h>
  26 #include <linux/capability.h>   /* capable() */
  27 #include <linux/uaccess.h>      /* copy_from_user(), copy_to_user() */
  28 #include <linux/vmalloc.h>
  29 #include <linux/mount.h>        /* mnt_want_write(), mnt_drop_write() */
  30 #include <linux/nilfs2_fs.h>
  31 #include "nilfs.h"
  32 #include "segment.h"
  33 #include "bmap.h"
  34 #include "cpfile.h"
  35 #include "sufile.h"
  36 #include "dat.h"
  37
  38
  39 static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
  40                                  struct nilfs_argv *argv, int dir,
  41                                  ssize_t (*dofunc)(struct the_nilfs *,
  42                                                    __u64 *, int,
  43                                                    void *, size_t, size_t))
  44 {
  45         void *buf;
  46         void __user *base = (void __user *)(unsigned long)argv->v_base;
  47         size_t maxmembs, total, n;
  48         ssize_t nr;
  49         int ret, i;
  50         __u64 pos, ppos;
  51
  52         if (argv->v_nmembs == 0)
  53                 return 0;
  54
  55         if (argv->v_size > PAGE_SIZE)
  56                 return -EINVAL;
  57
  58         buf = (void *)__get_free_pages(GFP_NOFS, 0);
  59         if (unlikely(!buf))
  60                 return -ENOMEM;
  61         maxmembs = PAGE_SIZE / argv->v_size;
  62
  63         ret = 0;
  64         total = 0;
  65         pos = argv->v_index;
  66         for (i = 0; i < argv->v_nmembs; i += n) {
  67                 n = (argv->v_nmembs - i < maxmembs) ?
  68                         argv->v_nmembs - i : maxmembs;
  69                 if ((dir & _IOC_WRITE) &&
  70                     copy_from_user(buf, base + argv->v_size * i,
  71                                    argv->v_size * n)) {
  72                         ret = -EFAULT;
  73                         break;
  74                 }
  75                 ppos = pos;
  76                 nr = dofunc(nilfs, &pos, argv->v_flags, buf, argv->v_size,
  77                                n);
  78                 if (nr < 0) {
  79                         ret = nr;
  80                         break;
  81                 }
  82                 if ((dir & _IOC_READ) &&
  83                     copy_to_user(base + argv->v_size * i, buf,
  84                                  argv->v_size * nr)) {
  85                         ret = -EFAULT;
  86                         break;
  87                 }
  88                 total += nr;
  89                 if ((size_t)nr < n)
  90                         break;
  91                 if (pos == ppos)
  92                         pos += n;
  93         }
  94         argv->v_nmembs = total;
  95
  96         free_pages((unsigned long)buf, 0);
  97         return ret;
  98 }
  99
 100 static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
 101                                      unsigned int cmd, void __user *argp)
 102 {
 103         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 104         struct inode *cpfile = nilfs->ns_cpfile;
 105         struct nilfs_transaction_info ti;
 106         struct nilfs_cpmode cpmode;
 107         int ret;
 108
 109         if (!capable(CAP_SYS_ADMIN))
 110                 return -EPERM;
 111
 112         ret = mnt_want_write(filp->f_path.mnt);
 113         if (ret)
 114                 return ret;
 115
 116         ret = -EFAULT;
 117         if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
 118                 goto out;
 119
 120         down_read(&inode->i_sb->s_umount);
 121
 122         nilfs_transaction_begin(inode->i_sb, &ti, 0);
 123         ret = nilfs_cpfile_change_cpmode(
 124                 cpfile, cpmode.cm_cno, cpmode.cm_mode);
 125         if (unlikely(ret < 0))
 126                 nilfs_transaction_abort(inode->i_sb);
 127         else
 128                 nilfs_transaction_commit(inode->i_sb); /* never fails */
 129
 130         up_read(&inode->i_sb->s_umount);
 131 out:
 132         mnt_drop_write(filp->f_path.mnt);
 133         return ret;
 134 }
 135
 136 static int
 137 nilfs_ioctl_delete_checkpoint(struct inode *inode, struct file *filp,
 138                               unsigned int cmd, void __user *argp)
 139 {
 140         struct inode *cpfile = NILFS_SB(inode->i_sb)->s_nilfs->ns_cpfile;
 141         struct nilfs_transaction_info ti;
 142         __u64 cno;
 143         int ret;
 144
 145         if (!capable(CAP_SYS_ADMIN))
 146                 return -EPERM;
 147
 148         ret = mnt_want_write(filp->f_path.mnt);
 149         if (ret)
 150                 return ret;
 151
 152         ret = -EFAULT;
 153         if (copy_from_user(&cno, argp, sizeof(cno)))
 154                 goto out;
 155
 156         nilfs_transaction_begin(inode->i_sb, &ti, 0);
 157         ret = nilfs_cpfile_delete_checkpoint(cpfile, cno);
 158         if (unlikely(ret < 0))
 159                 nilfs_transaction_abort(inode->i_sb);
 160         else
 161                 nilfs_transaction_commit(inode->i_sb); /* never fails */
 162 out:
 163         mnt_drop_write(filp->f_path.mnt);
 164         return ret;
 165 }
 166
 167 static ssize_t
 168 nilfs_ioctl_do_get_cpinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
 169                           void *buf, size_t size, size_t nmembs)
 170 {
 171         int ret;
 172
 173         down_read(&nilfs->ns_segctor_sem);
 174         ret = nilfs_cpfile_get_cpinfo(nilfs->ns_cpfile, posp, flags, buf,
 175                                       size, nmembs);
 176         up_read(&nilfs->ns_segctor_sem);
 177         return ret;
 178 }
 179
 180 static int nilfs_ioctl_get_cpstat(struct inode *inode, struct file *filp,
 181                                   unsigned int cmd, void __user *argp)
 182 {
 183         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 184         struct nilfs_cpstat cpstat;
 185         int ret;
 186
 187         down_read(&nilfs->ns_segctor_sem);
 188         ret = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
 189         up_read(&nilfs->ns_segctor_sem);
 190         if (ret < 0)
 191                 return ret;
 192
 193         if (copy_to_user(argp, &cpstat, sizeof(cpstat)))
 194                 ret = -EFAULT;
 195         return ret;
 196 }
 197
 198 static ssize_t
 199 nilfs_ioctl_do_get_suinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
 200                           void *buf, size_t size, size_t nmembs)
 201 {
 202         int ret;
 203
 204         down_read(&nilfs->ns_segctor_sem);
 205         ret = nilfs_sufile_get_suinfo(nilfs->ns_sufile, *posp, buf, size,
 206                                       nmembs);
 207         up_read(&nilfs->ns_segctor_sem);
 208         return ret;
 209 }
 210
 211 static int nilfs_ioctl_get_sustat(struct inode *inode, struct file *filp,
 212                                   unsigned int cmd, void __user *argp)
 213 {
 214         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 215         struct nilfs_sustat sustat;
 216         int ret;
 217
 218         down_read(&nilfs->ns_segctor_sem);
 219         ret = nilfs_sufile_get_stat(nilfs->ns_sufile, &sustat);
 220         up_read(&nilfs->ns_segctor_sem);
 221         if (ret < 0)
 222                 return ret;
 223
 224         if (copy_to_user(argp, &sustat, sizeof(sustat)))
 225                 ret = -EFAULT;
 226         return ret;
 227 }
 228
 229 static ssize_t
 230 nilfs_ioctl_do_get_vinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
 231                          void *buf, size_t size, size_t nmembs)
 232 {
 233         int ret;
 234
 235         down_read(&nilfs->ns_segctor_sem);
 236         ret = nilfs_dat_get_vinfo(nilfs_dat_inode(nilfs), buf, size, nmembs);
 237         up_read(&nilfs->ns_segctor_sem);
 238         return ret;
 239 }
 240
 241 static ssize_t
 242 nilfs_ioctl_do_get_bdescs(struct the_nilfs *nilfs, __u64 *posp, int flags,
 243                           void *buf, size_t size, size_t nmembs)
 244 {
 245         struct inode *dat = nilfs_dat_inode(nilfs);
 246         struct nilfs_bmap *bmap = NILFS_I(dat)->i_bmap;
 247         struct nilfs_bdesc *bdescs = buf;
 248         int ret, i;
 249
 250         down_read(&nilfs->ns_segctor_sem);
 251         for (i = 0; i < nmembs; i++) {
 252                 ret = nilfs_bmap_lookup_at_level(bmap,
 253                                                  bdescs[i].bd_offset,
 254                                                  bdescs[i].bd_level + 1,
 255                                                  &bdescs[i].bd_blocknr);
 256                 if (ret < 0) {
 257                         if (ret != -ENOENT) {
 258                                 up_read(&nilfs->ns_segctor_sem);
 259                                 return ret;
 260                         }
 261                         bdescs[i].bd_blocknr = 0;
 262                 }
 263         }
 264         up_read(&nilfs->ns_segctor_sem);
 265         return nmembs;
 266 }
 267
 268 static int nilfs_ioctl_get_bdescs(struct inode *inode, struct file *filp,
 269                                   unsigned int cmd, void __user *argp)
 270 {
 271         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 272         struct nilfs_argv argv;
 273         int ret;
 274
 275         if (copy_from_user(&argv, argp, sizeof(argv)))
 276                 return -EFAULT;
 277
 278         if (argv.v_size != sizeof(struct nilfs_bdesc))
 279                 return -EINVAL;
 280
 281         ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd),
 282                                     nilfs_ioctl_do_get_bdescs);
 283         if (ret < 0)
 284                 return ret;
 285
 286         if (copy_to_user(argp, &argv, sizeof(argv)))
 287                 ret = -EFAULT;
 288         return ret;
 289 }
 290
 291 static int nilfs_ioctl_move_inode_block(struct inode *inode,
 292                                         struct nilfs_vdesc *vdesc,
 293                                         struct list_head *buffers)
 294 {
 295         struct buffer_head *bh;
 296         int ret;
 297
 298         if (vdesc->vd_flags == 0)
 299                 ret = nilfs_gccache_submit_read_data(
 300                         inode, vdesc->vd_offset, vdesc->vd_blocknr,
 301                         vdesc->vd_vblocknr, &bh);
 302         else
 303                 ret = nilfs_gccache_submit_read_node(
 304                         inode, vdesc->vd_blocknr, vdesc->vd_vblocknr, &bh);
 305
 306         if (unlikely(ret < 0)) {
 307                 if (ret == -ENOENT)
 308                         printk(KERN_CRIT
 309                                "%s: invalid virtual block address (%s): "
 310                                "ino=%llu, cno=%llu, offset=%llu, "
 311                                "blocknr=%llu, vblocknr=%llu\n",
 312                                __func__, vdesc->vd_flags ? "node" : "data",
 313                                (unsigned long long)vdesc->vd_ino,
 314                                (unsigned long long)vdesc->vd_cno,
 315                                (unsigned long long)vdesc->vd_offset,
 316                                (unsigned long long)vdesc->vd_blocknr,
 317                                (unsigned long long)vdesc->vd_vblocknr);
 318                 return ret;
 319         }
 320         if (unlikely(!list_empty(&bh->b_assoc_buffers))) {
 321                 printk(KERN_CRIT "%s: conflicting %s buffer: ino=%llu, "
 322                        "cno=%llu, offset=%llu, blocknr=%llu, vblocknr=%llu\n",
 323                        __func__, vdesc->vd_flags ? "node" : "data",
 324                        (unsigned long long)vdesc->vd_ino,
 325                        (unsigned long long)vdesc->vd_cno,
 326                        (unsigned long long)vdesc->vd_offset,
 327                        (unsigned long long)vdesc->vd_blocknr,
 328                        (unsigned long long)vdesc->vd_vblocknr);
 329                 brelse(bh);
 330                 return -EEXIST;
 331         }
 332         list_add_tail(&bh->b_assoc_buffers, buffers);
 333         return 0;
 334 }
 335
 336 static int nilfs_ioctl_move_blocks(struct super_block *sb,
 337                                    struct nilfs_argv *argv, void *buf)
 338 {
 339         size_t nmembs = argv->v_nmembs;
 340         struct the_nilfs *nilfs = NILFS_SB(sb)->s_nilfs;
 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_iget_for_gc(sb, ino, cno);
 353                 if (IS_ERR(inode)) {
 354                         ret = PTR_ERR(inode);
 355                         goto failed;
 356                 }
 357                 if (list_empty(&NILFS_I(inode)->i_dirty)) {
 358                         /*
 359                          * Add the inode to GC inode list. Garbage Collection
 360                          * is serialized and no two processes manipulate the
 361                          * list simultaneously.
 362                          */
 363                         igrab(inode);
 364                         list_add(&NILFS_I(inode)->i_dirty,
 365                                  &nilfs->ns_gc_inodes);
 366                 }
 367
 368                 do {
 369                         ret = nilfs_ioctl_move_inode_block(inode, vdesc,
 370                                                            &buffers);
 371                         if (unlikely(ret < 0)) {
 372                                 iput(inode);
 373                                 goto failed;
 374                         }
 375                         vdesc++;
 376                 } while (++i < nmembs &&
 377                          vdesc->vd_ino == ino && vdesc->vd_cno == cno);
 378
 379                 iput(inode); /* The inode still remains in GC inode list */
 380         }
 381
 382         list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
 383                 ret = nilfs_gccache_wait_and_mark_dirty(bh);
 384                 if (unlikely(ret < 0)) {
 385                         WARN_ON(ret == -EEXIST);
 386                         goto failed;
 387                 }
 388                 list_del_init(&bh->b_assoc_buffers);
 389                 brelse(bh);
 390         }
 391         return nmembs;
 392
 393  failed:
 394         list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
 395                 list_del_init(&bh->b_assoc_buffers);
 396                 brelse(bh);
 397         }
 398         return ret;
 399 }
 400
 401 static int nilfs_ioctl_delete_checkpoints(struct the_nilfs *nilfs,
 402                                           struct nilfs_argv *argv, void *buf)
 403 {
 404         size_t nmembs = argv->v_nmembs;
 405         struct inode *cpfile = nilfs->ns_cpfile;
 406         struct nilfs_period *periods = buf;
 407         int ret, i;
 408
 409         for (i = 0; i < nmembs; i++) {
 410                 ret = nilfs_cpfile_delete_checkpoints(
 411                         cpfile, periods[i].p_start, periods[i].p_end);
 412                 if (ret < 0)
 413                         return ret;
 414         }
 415         return nmembs;
 416 }
 417
 418 static int nilfs_ioctl_free_vblocknrs(struct the_nilfs *nilfs,
 419                                       struct nilfs_argv *argv, void *buf)
 420 {
 421         size_t nmembs = argv->v_nmembs;
 422         int ret;
 423
 424         ret = nilfs_dat_freev(nilfs_dat_inode(nilfs), buf, nmembs);
 425
 426         return (ret < 0) ? ret : nmembs;
 427 }
 428
 429 static int nilfs_ioctl_mark_blocks_dirty(struct the_nilfs *nilfs,
 430                                          struct nilfs_argv *argv, void *buf)
 431 {
 432         size_t nmembs = argv->v_nmembs;
 433         struct inode *dat = nilfs_dat_inode(nilfs);
 434         struct nilfs_bmap *bmap = NILFS_I(dat)->i_bmap;
 435         struct nilfs_bdesc *bdescs = buf;
 436         int ret, i;
 437
 438         for (i = 0; i < nmembs; i++) {
 439                 /* XXX: use macro or inline func to check liveness */
 440                 ret = nilfs_bmap_lookup_at_level(bmap,
 441                                                  bdescs[i].bd_offset,
 442                                                  bdescs[i].bd_level + 1,
 443                                                  &bdescs[i].bd_blocknr);
 444                 if (ret < 0) {
 445                         if (ret != -ENOENT)
 446                                 return ret;
 447                         bdescs[i].bd_blocknr = 0;
 448                 }
 449                 if (bdescs[i].bd_blocknr != bdescs[i].bd_oblocknr)
 450                         /* skip dead block */
 451                         continue;
 452                 if (bdescs[i].bd_level == 0) {
 453                         ret = nilfs_mdt_mark_block_dirty(dat,
 454                                                          bdescs[i].bd_offset);
 455                         if (ret < 0) {
 456                                 WARN_ON(ret == -ENOENT);
 457                                 return ret;
 458                         }
 459                 } else {
 460                         ret = nilfs_bmap_mark(bmap, bdescs[i].bd_offset,
 461                                               bdescs[i].bd_level);
 462                         if (ret < 0) {
 463                                 WARN_ON(ret == -ENOENT);
 464                                 return ret;
 465                         }
 466                 }
 467         }
 468         return nmembs;
 469 }
 470
 471 int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *nilfs,
 472                                        struct nilfs_argv *argv, void **kbufs)
 473 {
 474         const char *msg;
 475         int ret;
 476
 477         ret = nilfs_ioctl_delete_checkpoints(nilfs, &argv[1], kbufs[1]);
 478         if (ret < 0) {
 479                 /*
 480                  * can safely abort because checkpoints can be removed
 481                  * independently.
 482                  */
 483                 msg = "cannot delete checkpoints";
 484                 goto failed;
 485         }
 486         ret = nilfs_ioctl_free_vblocknrs(nilfs, &argv[2], kbufs[2]);
 487         if (ret < 0) {
 488                 /*
 489                  * can safely abort because DAT file is updated atomically
 490                  * using a copy-on-write technique.
 491                  */
 492                 msg = "cannot delete virtual blocks from DAT file";
 493                 goto failed;
 494         }
 495         ret = nilfs_ioctl_mark_blocks_dirty(nilfs, &argv[3], kbufs[3]);
 496         if (ret < 0) {
 497                 /*
 498                  * can safely abort because the operation is nondestructive.
 499                  */
 500                 msg = "cannot mark copying blocks dirty";
 501                 goto failed;
 502         }
 503         return 0;
 504
 505  failed:
 506         printk(KERN_ERR "NILFS: GC failed during preparation: %s: err=%d\n",
 507                msg, ret);
 508         return ret;
 509 }
 510
 511 static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
 512                                       unsigned int cmd, void __user *argp)
 513 {
 514         struct nilfs_argv argv[5];
 515         static const size_t argsz[5] = {
 516                 sizeof(struct nilfs_vdesc),
 517                 sizeof(struct nilfs_period),
 518                 sizeof(__u64),
 519                 sizeof(struct nilfs_bdesc),
 520                 sizeof(__u64),
 521         };
 522         void __user *base;
 523         void *kbufs[5];
 524         struct the_nilfs *nilfs;
 525         size_t len, nsegs;
 526         int n, ret;
 527
 528         if (!capable(CAP_SYS_ADMIN))
 529                 return -EPERM;
 530
 531         ret = mnt_want_write(filp->f_path.mnt);
 532         if (ret)
 533                 return ret;
 534
 535         ret = -EFAULT;
 536         if (copy_from_user(argv, argp, sizeof(argv)))
 537                 goto out;
 538
 539         ret = -EINVAL;
 540         nsegs = argv[4].v_nmembs;
 541         if (argv[4].v_size != argsz[4])
 542                 goto out;
 543
 544         /*
 545          * argv[4] points to segment numbers this ioctl cleans.  We
 546          * use kmalloc() for its buffer because memory used for the
 547          * segment numbers is enough small.
 548          */
 549         kbufs[4] = memdup_user((void __user *)(unsigned long)argv[4].v_base,
 550                                nsegs * sizeof(__u64));
 551         if (IS_ERR(kbufs[4])) {
 552                 ret = PTR_ERR(kbufs[4]);
 553                 goto out;
 554         }
 555         nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 556
 557         for (n = 0; n < 4; n++) {
 558                 ret = -EINVAL;
 559                 if (argv[n].v_size != argsz[n])
 560                         goto out_free;
 561
 562                 if (argv[n].v_nmembs > nsegs * nilfs->ns_blocks_per_segment)
 563                         goto out_free;
 564
 565                 len = argv[n].v_size * argv[n].v_nmembs;
 566                 base = (void __user *)(unsigned long)argv[n].v_base;
 567                 if (len == 0) {
 568                         kbufs[n] = NULL;
 569                         continue;
 570                 }
 571
 572                 kbufs[n] = vmalloc(len);
 573                 if (!kbufs[n]) {
 574                         ret = -ENOMEM;
 575                         goto out_free;
 576                 }
 577                 if (copy_from_user(kbufs[n], base, len)) {
 578                         ret = -EFAULT;
 579                         vfree(kbufs[n]);
 580                         goto out_free;
 581                 }
 582         }
 583
 584         /*
 585          * nilfs_ioctl_move_blocks() will call nilfs_iget_for_gc(),
 586          * which will operates an inode list without blocking.
 587          * To protect the list from concurrent operations,
 588          * nilfs_ioctl_move_blocks should be atomic operation.
 589          */
 590         if (test_and_set_bit(THE_NILFS_GC_RUNNING, &nilfs->ns_flags)) {
 591                 ret = -EBUSY;
 592                 goto out_free;
 593         }
 594
 595         vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
 596
 597         ret = nilfs_ioctl_move_blocks(inode->i_sb, &argv[0], kbufs[0]);
 598         if (ret < 0)
 599                 printk(KERN_ERR "NILFS: GC failed during preparation: "
 600                         "cannot read source blocks: err=%d\n", ret);
 601         else
 602                 ret = nilfs_clean_segments(inode->i_sb, argv, kbufs);
 603
 604         nilfs_remove_all_gcinodes(nilfs);
 605         clear_nilfs_gc_running(nilfs);
 606
 607 out_free:
 608         while (--n >= 0)
 609                 vfree(kbufs[n]);
 610         kfree(kbufs[4]);
 611 out:
 612         mnt_drop_write(filp->f_path.mnt);
 613         return ret;
 614 }
 615
 616 static int nilfs_ioctl_sync(struct inode *inode, struct file *filp,
 617                             unsigned int cmd, void __user *argp)
 618 {
 619         __u64 cno;
 620         int ret;
 621         struct the_nilfs *nilfs;
 622
 623         ret = nilfs_construct_segment(inode->i_sb);
 624         if (ret < 0)
 625                 return ret;
 626
 627         if (argp != NULL) {
 628                 nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 629                 down_read(&nilfs->ns_segctor_sem);
 630                 cno = nilfs->ns_cno - 1;
 631                 up_read(&nilfs->ns_segctor_sem);
 632                 if (copy_to_user(argp, &cno, sizeof(cno)))
 633                         return -EFAULT;
 634         }
 635         return 0;
 636 }
 637
 638 static int nilfs_ioctl_get_info(struct inode *inode, struct file *filp,
 639                                 unsigned int cmd, void __user *argp,
 640                                 size_t membsz,
 641                                 ssize_t (*dofunc)(struct the_nilfs *,
 642                                                   __u64 *, int,
 643                                                   void *, size_t, size_t))
 644
 645 {
 646         struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 647         struct nilfs_argv argv;
 648         int ret;
 649
 650         if (copy_from_user(&argv, argp, sizeof(argv)))
 651                 return -EFAULT;
 652
 653         if (argv.v_size < membsz)
 654                 return -EINVAL;
 655
 656         ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd), dofunc);
 657         if (ret < 0)
 658                 return ret;
 659
 660         if (copy_to_user(argp, &argv, sizeof(argv)))
 661                 ret = -EFAULT;
 662         return ret;
 663 }
 664
 665 long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 666 {
 667         struct inode *inode = filp->f_dentry->d_inode;
 668         void __user *argp = (void __user *)arg;
 669
 670         switch (cmd) {
 671         case NILFS_IOCTL_CHANGE_CPMODE:
 672                 return nilfs_ioctl_change_cpmode(inode, filp, cmd, argp);
 673         case NILFS_IOCTL_DELETE_CHECKPOINT:
 674                 return nilfs_ioctl_delete_checkpoint(inode, filp, cmd, argp);
 675         case NILFS_IOCTL_GET_CPINFO:
 676                 return nilfs_ioctl_get_info(inode, filp, cmd, argp,
 677                                             sizeof(struct nilfs_cpinfo),
 678                                             nilfs_ioctl_do_get_cpinfo);
 679         case NILFS_IOCTL_GET_CPSTAT:
 680                 return nilfs_ioctl_get_cpstat(inode, filp, cmd, argp);
 681         case NILFS_IOCTL_GET_SUINFO:
 682                 return nilfs_ioctl_get_info(inode, filp, cmd, argp,
 683                                             sizeof(struct nilfs_suinfo),
 684                                             nilfs_ioctl_do_get_suinfo);
 685         case NILFS_IOCTL_GET_SUSTAT:
 686                 return nilfs_ioctl_get_sustat(inode, filp, cmd, argp);
 687         case NILFS_IOCTL_GET_VINFO:
 688                 return nilfs_ioctl_get_info(inode, filp, cmd, argp,
 689                                             sizeof(struct nilfs_vinfo),
 690                                             nilfs_ioctl_do_get_vinfo);
 691         case NILFS_IOCTL_GET_BDESCS:
 692                 return nilfs_ioctl_get_bdescs(inode, filp, cmd, argp);
 693         case NILFS_IOCTL_CLEAN_SEGMENTS:
 694                 return nilfs_ioctl_clean_segments(inode, filp, cmd, argp);
 695         case NILFS_IOCTL_SYNC:
 696                 return nilfs_ioctl_sync(inode, filp, cmd, argp);
 697         default:
 698                 return -ENOTTY;
 699         }
 700 }