release/src-rt-6.x/linux/linux-2.6/fs/ufs/ialloc.c

   1 /*
   2  *  linux/fs/ufs/ialloc.c
   3  *
   4  * Copyright (c) 1998
   5  * Daniel Pirkl <daniel.pirkl@email.cz>
   6  * Charles University, Faculty of Mathematics and Physics
   7  *
   8  *  from
   9  *
  10  *  linux/fs/ext2/ialloc.c
  11  *
  12  * Copyright (C) 1992, 1993, 1994, 1995
  13  * Remy Card (card@masi.ibp.fr)
  14  * Laboratoire MASI - Institut Blaise Pascal
  15  * Universite Pierre et Marie Curie (Paris VI)
  16  *
  17  *  BSD ufs-inspired inode and directory allocation by
  18  *  Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
  19  *  Big-endian to little-endian byte-swapping/bitmaps by
  20  *        David S. Miller (davem@caip.rutgers.edu), 1995
  21  *
  22  * UFS2 write support added by
  23  * Evgeniy Dushistov <dushistov@mail.ru>, 2007
  24  */
  25
  26 #include <linux/fs.h>
  27 #include <linux/ufs_fs.h>
  28 #include <linux/time.h>
  29 #include <linux/stat.h>
  30 #include <linux/string.h>
  31 #include <linux/quotaops.h>
  32 #include <linux/buffer_head.h>
  33 #include <linux/sched.h>
  34 #include <linux/bitops.h>
  35 #include <asm/byteorder.h>
  36
  37 #include "swab.h"
  38 #include "util.h"
  39
  40 /*
  41  * NOTE! When we get the inode, we're the only people
  42  * that have access to it, and as such there are no
  43  * race conditions we have to worry about. The inode
  44  * is not on the hash-lists, and it cannot be reached
  45  * through the filesystem because the directory entry
  46  * has been deleted earlier.
  47  *
  48  * HOWEVER: we must make sure that we get no aliases,
  49  * which means that we have to call "clear_inode()"
  50  * _before_ we mark the inode not in use in the inode
  51  * bitmaps. Otherwise a newly created file might use
  52  * the same inode number (not actually the same pointer
  53  * though), and then we'd have two inodes sharing the
  54  * same inode number and space on the harddisk.
  55  */
  56 void ufs_free_inode (struct inode * inode)
  57 {
  58         struct super_block * sb;
  59         struct ufs_sb_private_info * uspi;
  60         struct ufs_super_block_first * usb1;
  61         struct ufs_cg_private_info * ucpi;
  62         struct ufs_cylinder_group * ucg;
  63         int is_directory;
  64         unsigned ino, cg, bit;
  65
  66         UFSD("ENTER, ino %lu\n", inode->i_ino);
  67
  68         sb = inode->i_sb;
  69         uspi = UFS_SB(sb)->s_uspi;
  70         usb1 = ubh_get_usb_first(uspi);
  71
  72         ino = inode->i_ino;
  73
  74         lock_super (sb);
  75
  76         if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) {
  77                 ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino);
  78                 unlock_super (sb);
  79                 return;
  80         }
  81
  82         cg = ufs_inotocg (ino);
  83         bit = ufs_inotocgoff (ino);
  84         ucpi = ufs_load_cylinder (sb, cg);
  85         if (!ucpi) {
  86                 unlock_super (sb);
  87                 return;
  88         }
  89         ucg = ubh_get_ucg(UCPI_UBH(ucpi));
  90         if (!ufs_cg_chkmagic(sb, ucg))
  91                 ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number");
  92
  93         ucg->cg_time = cpu_to_fs32(sb, get_seconds());
  94
  95         is_directory = S_ISDIR(inode->i_mode);
  96
  97         DQUOT_FREE_INODE(inode);
  98         DQUOT_DROP(inode);
  99
 100         clear_inode (inode);
 101
 102         if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
 103                 ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino);
 104         else {
 105                 ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
 106                 if (ino < ucpi->c_irotor)
 107                         ucpi->c_irotor = ino;
 108                 fs32_add(sb, &ucg->cg_cs.cs_nifree, 1);
 109                 uspi->cs_total.cs_nifree++;
 110                 fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1);
 111
 112                 if (is_directory) {
 113                         fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1);
 114                         uspi->cs_total.cs_ndir--;
 115                         fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1);
 116                 }
 117         }
 118
 119         ubh_mark_buffer_dirty (USPI_UBH(uspi));
 120         ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
 121         if (sb->s_flags & MS_SYNCHRONOUS) {
 122                 ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
 123                 ubh_wait_on_buffer (UCPI_UBH(ucpi));
 124         }
 125
 126         sb->s_dirt = 1;
 127         unlock_super (sb);
 128         UFSD("EXIT\n");
 129 }
 130
 131 /*
 132  * Nullify new chunk of inodes,
 133  * BSD people also set ui_gen field of inode
 134  * during nullification, but we not care about
 135  * that because of linux ufs do not support NFS
 136  */
 137 static void ufs2_init_inodes_chunk(struct super_block *sb,
 138                                    struct ufs_cg_private_info *ucpi,
 139                                    struct ufs_cylinder_group *ucg)
 140 {
 141         struct buffer_head *bh;
 142         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 143         sector_t beg = uspi->s_sbbase +
 144                 ufs_inotofsba(ucpi->c_cgx * uspi->s_ipg +
 145                               fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk));
 146         sector_t end = beg + uspi->s_fpb;
 147
 148         UFSD("ENTER cgno %d\n", ucpi->c_cgx);
 149
 150         for (; beg < end; ++beg) {
 151                 bh = sb_getblk(sb, beg);
 152                 lock_buffer(bh);
 153                 memset(bh->b_data, 0, sb->s_blocksize);
 154                 set_buffer_uptodate(bh);
 155                 mark_buffer_dirty(bh);
 156                 unlock_buffer(bh);
 157                 if (sb->s_flags & MS_SYNCHRONOUS)
 158                         sync_dirty_buffer(bh);
 159                 brelse(bh);
 160         }
 161
 162         fs32_add(sb, &ucg->cg_u.cg_u2.cg_initediblk, uspi->s_inopb);
 163         ubh_mark_buffer_dirty(UCPI_UBH(ucpi));
 164         if (sb->s_flags & MS_SYNCHRONOUS) {
 165                 ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
 166                 ubh_wait_on_buffer(UCPI_UBH(ucpi));
 167         }
 168
 169         UFSD("EXIT\n");
 170 }
 171
 172 /*
 173  * There are two policies for allocating an inode.  If the new inode is
 174  * a directory, then a forward search is made for a block group with both
 175  * free space and a low directory-to-inode ratio; if that fails, then of
 176  * the groups with above-average free space, that group with the fewest
 177  * directories already is chosen.
 178  *
 179  * For other inodes, search forward from the parent directory's block
 180  * group to find a free inode.
 181  */
 182 struct inode * ufs_new_inode(struct inode * dir, int mode)
 183 {
 184         struct super_block * sb;
 185         struct ufs_sb_info * sbi;
 186         struct ufs_sb_private_info * uspi;
 187         struct ufs_super_block_first * usb1;
 188         struct ufs_cg_private_info * ucpi;
 189         struct ufs_cylinder_group * ucg;
 190         struct inode * inode;
 191         unsigned cg, bit, i, j, start;
 192         struct ufs_inode_info *ufsi;
 193         int err = -ENOSPC;
 194
 195         UFSD("ENTER\n");
 196
 197         /* Cannot create files in a deleted directory */
 198         if (!dir || !dir->i_nlink)
 199                 return ERR_PTR(-EPERM);
 200         sb = dir->i_sb;
 201         inode = new_inode(sb);
 202         if (!inode)
 203                 return ERR_PTR(-ENOMEM);
 204         ufsi = UFS_I(inode);
 205         sbi = UFS_SB(sb);
 206         uspi = sbi->s_uspi;
 207         usb1 = ubh_get_usb_first(uspi);
 208
 209         lock_super (sb);
 210
 211         /*
 212          * Try to place the inode in its parent directory
 213          */
 214         i = ufs_inotocg(dir->i_ino);
 215         if (sbi->fs_cs(i).cs_nifree) {
 216                 cg = i;
 217                 goto cg_found;
 218         }
 219
 220         /*
 221          * Use a quadratic hash to find a group with a free inode
 222          */
 223         for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
 224                 i += j;
 225                 if (i >= uspi->s_ncg)
 226                         i -= uspi->s_ncg;
 227                 if (sbi->fs_cs(i).cs_nifree) {
 228                         cg = i;
 229                         goto cg_found;
 230                 }
 231         }
 232
 233         /*
 234          * That failed: try linear search for a free inode
 235          */
 236         i = ufs_inotocg(dir->i_ino) + 1;
 237         for (j = 2; j < uspi->s_ncg; j++) {
 238                 i++;
 239                 if (i >= uspi->s_ncg)
 240                         i = 0;
 241                 if (sbi->fs_cs(i).cs_nifree) {
 242                         cg = i;
 243                         goto cg_found;
 244                 }
 245         }
 246
 247         goto failed;
 248
 249 cg_found:
 250         ucpi = ufs_load_cylinder (sb, cg);
 251         if (!ucpi) {
 252                 err = -EIO;
 253                 goto failed;
 254         }
 255         ucg = ubh_get_ucg(UCPI_UBH(ucpi));
 256         if (!ufs_cg_chkmagic(sb, ucg))
 257                 ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");
 258
 259         start = ucpi->c_irotor;
 260         bit = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, uspi->s_ipg, start);
 261         if (!(bit < uspi->s_ipg)) {
 262                 bit = ubh_find_first_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, start);
 263                 if (!(bit < start)) {
 264                         ufs_error (sb, "ufs_new_inode",
 265                             "cylinder group %u corrupted - error in inode bitmap\n", cg);
 266                         err = -EIO;
 267                         goto failed;
 268                 }
 269         }
 270         UFSD("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg);
 271         if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
 272                 ubh_setbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
 273         else {
 274                 ufs_panic (sb, "ufs_new_inode", "internal error");
 275                 err = -EIO;
 276                 goto failed;
 277         }
 278
 279         if (uspi->fs_magic == UFS2_MAGIC) {
 280                 u32 initediblk = fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk);
 281
 282                 if (bit + uspi->s_inopb > initediblk &&
 283                     initediblk < fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_niblk))
 284                         ufs2_init_inodes_chunk(sb, ucpi, ucg);
 285         }
 286
 287         fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1);
 288         uspi->cs_total.cs_nifree--;
 289         fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1);
 290
 291         if (S_ISDIR(mode)) {
 292                 fs32_add(sb, &ucg->cg_cs.cs_ndir, 1);
 293                 uspi->cs_total.cs_ndir++;
 294                 fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1);
 295         }
 296         ubh_mark_buffer_dirty (USPI_UBH(uspi));
 297         ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
 298         if (sb->s_flags & MS_SYNCHRONOUS) {
 299                 ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
 300                 ubh_wait_on_buffer (UCPI_UBH(ucpi));
 301         }
 302         sb->s_dirt = 1;
 303
 304         inode->i_ino = cg * uspi->s_ipg + bit;
 305         inode->i_mode = mode;
 306         inode->i_uid = current->fsuid;
 307         if (dir->i_mode & S_ISGID) {
 308                 inode->i_gid = dir->i_gid;
 309                 if (S_ISDIR(mode))
 310                         inode->i_mode |= S_ISGID;
 311         } else
 312                 inode->i_gid = current->fsgid;
 313
 314         inode->i_blocks = 0;
 315         inode->i_generation = 0;
 316         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 317         ufsi->i_flags = UFS_I(dir)->i_flags;
 318         ufsi->i_lastfrag = 0;
 319         ufsi->i_shadow = 0;
 320         ufsi->i_osync = 0;
 321         ufsi->i_oeftflag = 0;
 322         ufsi->i_dir_start_lookup = 0;
 323         memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));
 324         insert_inode_hash(inode);
 325         mark_inode_dirty(inode);
 326
 327         if (uspi->fs_magic == UFS2_MAGIC) {
 328                 struct buffer_head *bh;
 329                 struct ufs2_inode *ufs2_inode;
 330
 331                 /*
 332                  * setup birth date, we do it here because of there is no sense
 333                  * to hold it in struct ufs_inode_info, and lose 64 bit
 334                  */
 335                 bh = sb_bread(sb, uspi->s_sbbase + ufs_inotofsba(inode->i_ino));
 336                 if (!bh) {
 337                         ufs_warning(sb, "ufs_read_inode",
 338                                     "unable to read inode %lu\n",
 339                                     inode->i_ino);
 340                         err = -EIO;
 341                         goto fail_remove_inode;
 342                 }
 343                 lock_buffer(bh);
 344                 ufs2_inode = (struct ufs2_inode *)bh->b_data;
 345                 ufs2_inode += ufs_inotofsbo(inode->i_ino);
 346                 ufs2_inode->ui_birthtime = cpu_to_fs64(sb, CURRENT_TIME.tv_sec);
 347                 ufs2_inode->ui_birthnsec = cpu_to_fs32(sb, CURRENT_TIME.tv_nsec);
 348                 mark_buffer_dirty(bh);
 349                 unlock_buffer(bh);
 350                 if (sb->s_flags & MS_SYNCHRONOUS)
 351                         sync_dirty_buffer(bh);
 352                 brelse(bh);
 353         }
 354
 355         unlock_super (sb);
 356
 357         if (DQUOT_ALLOC_INODE(inode)) {
 358                 DQUOT_DROP(inode);
 359                 err = -EDQUOT;
 360                 goto fail_without_unlock;
 361         }
 362
 363         UFSD("allocating inode %lu\n", inode->i_ino);
 364         UFSD("EXIT\n");
 365         return inode;
 366
 367 fail_remove_inode:
 368         unlock_super(sb);
 369 fail_without_unlock:
 370         inode->i_flags |= S_NOQUOTA;
 371         inode->i_nlink = 0;
 372         iput(inode);
 373         UFSD("EXIT (FAILED): err %d\n", err);
 374         return ERR_PTR(err);
 375 failed:
 376         unlock_super (sb);
 377         make_bad_inode(inode);
 378         iput (inode);
 379         UFSD("EXIT (FAILED): err %d\n", err);
 380         return ERR_PTR(err);
 381 }