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/time.h>
  28 #include <linux/stat.h>
  29 #include <linux/string.h>
  30 #include <linux/buffer_head.h>
  31 #include <linux/sched.h>
  32 #include <linux/bitops.h>
  33 #include <asm/byteorder.h>
  34
  35 #include "ufs_fs.h"
  36 #include "ufs.h"
  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_cg_private_info * ucpi;
  61         struct ufs_cylinder_group * ucg;
  62         int is_directory;
  63         unsigned ino, cg, bit;
  64
  65         UFSD("ENTER, ino %lu\n", inode->i_ino);
  66
  67         sb = inode->i_sb;
  68         uspi = UFS_SB(sb)->s_uspi;
  69
  70         ino = inode->i_ino;
  71
  72         mutex_lock(&UFS_SB(sb)->s_lock);
  73
  74         if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) {
  75                 ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino);
  76                 mutex_unlock(&UFS_SB(sb)->s_lock);
  77                 return;
  78         }
  79
  80         cg = ufs_inotocg (ino);
  81         bit = ufs_inotocgoff (ino);
  82         ucpi = ufs_load_cylinder (sb, cg);
  83         if (!ucpi) {
  84                 mutex_unlock(&UFS_SB(sb)->s_lock);
  85                 return;
  86         }
  87         ucg = ubh_get_ucg(UCPI_UBH(ucpi));
  88         if (!ufs_cg_chkmagic(sb, ucg))
  89                 ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number");
  90
  91         ucg->cg_time = cpu_to_fs32(sb, get_seconds());
  92
  93         is_directory = S_ISDIR(inode->i_mode);
  94
  95         if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
  96                 ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino);
  97         else {
  98                 ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
  99                 if (ino < ucpi->c_irotor)
 100                         ucpi->c_irotor = ino;
 101                 fs32_add(sb, &ucg->cg_cs.cs_nifree, 1);
 102                 uspi->cs_total.cs_nifree++;
 103                 fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1);
 104
 105                 if (is_directory) {
 106                         fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1);
 107                         uspi->cs_total.cs_ndir--;
 108                         fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1);
 109                 }
 110         }
 111
 112         ubh_mark_buffer_dirty (USPI_UBH(uspi));
 113         ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
 114         if (sb->s_flags & MS_SYNCHRONOUS)
 115                 ubh_sync_block(UCPI_UBH(ucpi));
 116
 117         ufs_mark_sb_dirty(sb);
 118         mutex_unlock(&UFS_SB(sb)->s_lock);
 119         UFSD("EXIT\n");
 120 }
 121
 122 /*
 123  * Nullify new chunk of inodes,
 124  * BSD people also set ui_gen field of inode
 125  * during nullification, but we not care about
 126  * that because of linux ufs do not support NFS
 127  */
 128 static void ufs2_init_inodes_chunk(struct super_block *sb,
 129                                    struct ufs_cg_private_info *ucpi,
 130                                    struct ufs_cylinder_group *ucg)
 131 {
 132         struct buffer_head *bh;
 133         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 134         sector_t beg = uspi->s_sbbase +
 135                 ufs_inotofsba(ucpi->c_cgx * uspi->s_ipg +
 136                               fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk));
 137         sector_t end = beg + uspi->s_fpb;
 138
 139         UFSD("ENTER cgno %d\n", ucpi->c_cgx);
 140
 141         for (; beg < end; ++beg) {
 142                 bh = sb_getblk(sb, beg);
 143                 lock_buffer(bh);
 144                 memset(bh->b_data, 0, sb->s_blocksize);
 145                 set_buffer_uptodate(bh);
 146                 mark_buffer_dirty(bh);
 147                 unlock_buffer(bh);
 148                 if (sb->s_flags & MS_SYNCHRONOUS)
 149                         sync_dirty_buffer(bh);
 150                 brelse(bh);
 151         }
 152
 153         fs32_add(sb, &ucg->cg_u.cg_u2.cg_initediblk, uspi->s_inopb);
 154         ubh_mark_buffer_dirty(UCPI_UBH(ucpi));
 155         if (sb->s_flags & MS_SYNCHRONOUS)
 156                 ubh_sync_block(UCPI_UBH(ucpi));
 157
 158         UFSD("EXIT\n");
 159 }
 160
 161 /*
 162  * There are two policies for allocating an inode.  If the new inode is
 163  * a directory, then a forward search is made for a block group with both
 164  * free space and a low directory-to-inode ratio; if that fails, then of
 165  * the groups with above-average free space, that group with the fewest
 166  * directories already is chosen.
 167  *
 168  * For other inodes, search forward from the parent directory's block
 169  * group to find a free inode.
 170  */
 171 struct inode *ufs_new_inode(struct inode *dir, umode_t mode)
 172 {
 173         struct super_block * sb;
 174         struct ufs_sb_info * sbi;
 175         struct ufs_sb_private_info * uspi;
 176         struct ufs_cg_private_info * ucpi;
 177         struct ufs_cylinder_group * ucg;
 178         struct inode * inode;
 179         unsigned cg, bit, i, j, start;
 180         struct ufs_inode_info *ufsi;
 181         int err = -ENOSPC;
 182
 183         UFSD("ENTER\n");
 184
 185         /* Cannot create files in a deleted directory */
 186         if (!dir || !dir->i_nlink)
 187                 return ERR_PTR(-EPERM);
 188         sb = dir->i_sb;
 189         inode = new_inode(sb);
 190         if (!inode)
 191                 return ERR_PTR(-ENOMEM);
 192         ufsi = UFS_I(inode);
 193         sbi = UFS_SB(sb);
 194         uspi = sbi->s_uspi;
 195
 196         mutex_lock(&sbi->s_lock);
 197
 198         /*
 199          * Try to place the inode in its parent directory
 200          */
 201         i = ufs_inotocg(dir->i_ino);
 202         if (sbi->fs_cs(i).cs_nifree) {
 203                 cg = i;
 204                 goto cg_found;
 205         }
 206
 207         /*
 208          * Use a quadratic hash to find a group with a free inode
 209          */
 210         for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
 211                 i += j;
 212                 if (i >= uspi->s_ncg)
 213                         i -= uspi->s_ncg;
 214                 if (sbi->fs_cs(i).cs_nifree) {
 215                         cg = i;
 216                         goto cg_found;
 217                 }
 218         }
 219
 220         /*
 221          * That failed: try linear search for a free inode
 222          */
 223         i = ufs_inotocg(dir->i_ino) + 1;
 224         for (j = 2; j < uspi->s_ncg; j++) {
 225                 i++;
 226                 if (i >= uspi->s_ncg)
 227                         i = 0;
 228                 if (sbi->fs_cs(i).cs_nifree) {
 229                         cg = i;
 230                         goto cg_found;
 231                 }
 232         }
 233
 234         goto failed;
 235
 236 cg_found:
 237         ucpi = ufs_load_cylinder (sb, cg);
 238         if (!ucpi) {
 239                 err = -EIO;
 240                 goto failed;
 241         }
 242         ucg = ubh_get_ucg(UCPI_UBH(ucpi));
 243         if (!ufs_cg_chkmagic(sb, ucg))
 244                 ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");
 245
 246         start = ucpi->c_irotor;
 247         bit = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, uspi->s_ipg, start);
 248         if (!(bit < uspi->s_ipg)) {
 249                 bit = ubh_find_first_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, start);
 250                 if (!(bit < start)) {
 251                         ufs_error (sb, "ufs_new_inode",
 252                             "cylinder group %u corrupted - error in inode bitmap\n", cg);
 253                         err = -EIO;
 254                         goto failed;
 255                 }
 256         }
 257         UFSD("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg);
 258         if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
 259                 ubh_setbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
 260         else {
 261                 ufs_panic (sb, "ufs_new_inode", "internal error");
 262                 err = -EIO;
 263                 goto failed;
 264         }
 265
 266         if (uspi->fs_magic == UFS2_MAGIC) {
 267                 u32 initediblk = fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk);
 268
 269                 if (bit + uspi->s_inopb > initediblk &&
 270                     initediblk < fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_niblk))
 271                         ufs2_init_inodes_chunk(sb, ucpi, ucg);
 272         }
 273
 274         fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1);
 275         uspi->cs_total.cs_nifree--;
 276         fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1);
 277
 278         if (S_ISDIR(mode)) {
 279                 fs32_add(sb, &ucg->cg_cs.cs_ndir, 1);
 280                 uspi->cs_total.cs_ndir++;
 281                 fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1);
 282         }
 283         ubh_mark_buffer_dirty (USPI_UBH(uspi));
 284         ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
 285         if (sb->s_flags & MS_SYNCHRONOUS)
 286                 ubh_sync_block(UCPI_UBH(ucpi));
 287         ufs_mark_sb_dirty(sb);
 288
 289         inode->i_ino = cg * uspi->s_ipg + bit;
 290         inode_init_owner(inode, dir, mode);
 291         inode->i_blocks = 0;
 292         inode->i_generation = 0;
 293         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 294         ufsi->i_flags = UFS_I(dir)->i_flags;
 295         ufsi->i_lastfrag = 0;
 296         ufsi->i_shadow = 0;
 297         ufsi->i_osync = 0;
 298         ufsi->i_oeftflag = 0;
 299         ufsi->i_dir_start_lookup = 0;
 300         memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));
 301         if (insert_inode_locked(inode) < 0) {
 302                 err = -EIO;
 303                 goto failed;
 304         }
 305         mark_inode_dirty(inode);
 306
 307         if (uspi->fs_magic == UFS2_MAGIC) {
 308                 struct buffer_head *bh;
 309                 struct ufs2_inode *ufs2_inode;
 310
 311                 /*
 312                  * setup birth date, we do it here because of there is no sense
 313                  * to hold it in struct ufs_inode_info, and lose 64 bit
 314                  */
 315                 bh = sb_bread(sb, uspi->s_sbbase + ufs_inotofsba(inode->i_ino));
 316                 if (!bh) {
 317                         ufs_warning(sb, "ufs_read_inode",
 318                                     "unable to read inode %lu\n",
 319                                     inode->i_ino);
 320                         err = -EIO;
 321                         goto fail_remove_inode;
 322                 }
 323                 lock_buffer(bh);
 324                 ufs2_inode = (struct ufs2_inode *)bh->b_data;
 325                 ufs2_inode += ufs_inotofsbo(inode->i_ino);
 326                 ufs2_inode->ui_birthtime = cpu_to_fs64(sb, CURRENT_TIME.tv_sec);
 327                 ufs2_inode->ui_birthnsec = cpu_to_fs32(sb, CURRENT_TIME.tv_nsec);
 328                 mark_buffer_dirty(bh);
 329                 unlock_buffer(bh);
 330                 if (sb->s_flags & MS_SYNCHRONOUS)
 331                         sync_dirty_buffer(bh);
 332                 brelse(bh);
 333         }
 334         mutex_unlock(&sbi->s_lock);
 335
 336         UFSD("allocating inode %lu\n", inode->i_ino);
 337         UFSD("EXIT\n");
 338         return inode;
 339
 340 fail_remove_inode:
 341         mutex_unlock(&sbi->s_lock);
 342         clear_nlink(inode);
 343         unlock_new_inode(inode);
 344         iput(inode);
 345         UFSD("EXIT (FAILED): err %d\n", err);
 346         return ERR_PTR(err);
 347 failed:
 348         mutex_unlock(&sbi->s_lock);
 349         make_bad_inode(inode);
 350         iput (inode);
 351         UFSD("EXIT (FAILED): err %d\n", err);
 352         return ERR_PTR(err);
 353 }