linux/fs/ufs/ialloc.c
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   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 */
  56void 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        mutex_lock(&UFS_SB(sb)->s_lock);
  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                mutex_unlock(&UFS_SB(sb)->s_lock);
  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                mutex_unlock(&UFS_SB(sb)->s_lock);
  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        if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
  98                ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino);
  99        else {
 100                ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
 101                if (ino < ucpi->c_irotor)
 102                        ucpi->c_irotor = ino;
 103                fs32_add(sb, &ucg->cg_cs.cs_nifree, 1);
 104                uspi->cs_total.cs_nifree++;
 105                fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1);
 106
 107                if (is_directory) {
 108                        fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1);
 109                        uspi->cs_total.cs_ndir--;
 110                        fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1);
 111                }
 112        }
 113
 114        ubh_mark_buffer_dirty (USPI_UBH(uspi));
 115        ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
 116        if (sb->s_flags & MS_SYNCHRONOUS)
 117                ubh_sync_block(UCPI_UBH(ucpi));
 118        
 119        ufs_mark_sb_dirty(sb);
 120        mutex_unlock(&UFS_SB(sb)->s_lock);
 121        UFSD("EXIT\n");
 122}
 123
 124/*
 125 * Nullify new chunk of inodes,
 126 * BSD people also set ui_gen field of inode
 127 * during nullification, but we not care about
 128 * that because of linux ufs do not support NFS
 129 */
 130static void ufs2_init_inodes_chunk(struct super_block *sb,
 131                                   struct ufs_cg_private_info *ucpi,
 132                                   struct ufs_cylinder_group *ucg)
 133{
 134        struct buffer_head *bh;
 135        struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 136        sector_t beg = uspi->s_sbbase +
 137                ufs_inotofsba(ucpi->c_cgx * uspi->s_ipg +
 138                              fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk));
 139        sector_t end = beg + uspi->s_fpb;
 140
 141        UFSD("ENTER cgno %d\n", ucpi->c_cgx);
 142
 143        for (; beg < end; ++beg) {
 144                bh = sb_getblk(sb, beg);
 145                lock_buffer(bh);
 146                memset(bh->b_data, 0, sb->s_blocksize);
 147                set_buffer_uptodate(bh);
 148                mark_buffer_dirty(bh);
 149                unlock_buffer(bh);
 150                if (sb->s_flags & MS_SYNCHRONOUS)
 151                        sync_dirty_buffer(bh);
 152                brelse(bh);
 153        }
 154
 155        fs32_add(sb, &ucg->cg_u.cg_u2.cg_initediblk, uspi->s_inopb);
 156        ubh_mark_buffer_dirty(UCPI_UBH(ucpi));
 157        if (sb->s_flags & MS_SYNCHRONOUS)
 158                ubh_sync_block(UCPI_UBH(ucpi));
 159
 160        UFSD("EXIT\n");
 161}
 162
 163/*
 164 * There are two policies for allocating an inode.  If the new inode is
 165 * a directory, then a forward search is made for a block group with both
 166 * free space and a low directory-to-inode ratio; if that fails, then of
 167 * the groups with above-average free space, that group with the fewest
 168 * directories already is chosen.
 169 *
 170 * For other inodes, search forward from the parent directory's block
 171 * group to find a free inode.
 172 */
 173struct inode *ufs_new_inode(struct inode *dir, umode_t mode)
 174{
 175        struct super_block * sb;
 176        struct ufs_sb_info * sbi;
 177        struct ufs_sb_private_info * uspi;
 178        struct ufs_super_block_first * usb1;
 179        struct ufs_cg_private_info * ucpi;
 180        struct ufs_cylinder_group * ucg;
 181        struct inode * inode;
 182        unsigned cg, bit, i, j, start;
 183        struct ufs_inode_info *ufsi;
 184        int err = -ENOSPC;
 185
 186        UFSD("ENTER\n");
 187        
 188        /* Cannot create files in a deleted directory */
 189        if (!dir || !dir->i_nlink)
 190                return ERR_PTR(-EPERM);
 191        sb = dir->i_sb;
 192        inode = new_inode(sb);
 193        if (!inode)
 194                return ERR_PTR(-ENOMEM);
 195        ufsi = UFS_I(inode);
 196        sbi = UFS_SB(sb);
 197        uspi = sbi->s_uspi;
 198        usb1 = ubh_get_usb_first(uspi);
 199
 200        mutex_lock(&sbi->s_lock);
 201
 202        /*
 203         * Try to place the inode in its parent directory
 204         */
 205        i = ufs_inotocg(dir->i_ino);
 206        if (sbi->fs_cs(i).cs_nifree) {
 207                cg = i;
 208                goto cg_found;
 209        }
 210
 211        /*
 212         * Use a quadratic hash to find a group with a free inode
 213         */
 214        for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
 215                i += j;
 216                if (i >= uspi->s_ncg)
 217                        i -= uspi->s_ncg;
 218                if (sbi->fs_cs(i).cs_nifree) {
 219                        cg = i;
 220                        goto cg_found;
 221                }
 222        }
 223
 224        /*
 225         * That failed: try linear search for a free inode
 226         */
 227        i = ufs_inotocg(dir->i_ino) + 1;
 228        for (j = 2; j < uspi->s_ncg; j++) {
 229                i++;
 230                if (i >= uspi->s_ncg)
 231                        i = 0;
 232                if (sbi->fs_cs(i).cs_nifree) {
 233                        cg = i;
 234                        goto cg_found;
 235                }
 236        }
 237
 238        goto failed;
 239
 240cg_found:
 241        ucpi = ufs_load_cylinder (sb, cg);
 242        if (!ucpi) {
 243                err = -EIO;
 244                goto failed;
 245        }
 246        ucg = ubh_get_ucg(UCPI_UBH(ucpi));
 247        if (!ufs_cg_chkmagic(sb, ucg)) 
 248                ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");
 249
 250        start = ucpi->c_irotor;
 251        bit = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, uspi->s_ipg, start);
 252        if (!(bit < uspi->s_ipg)) {
 253                bit = ubh_find_first_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, start);
 254                if (!(bit < start)) {
 255                        ufs_error (sb, "ufs_new_inode",
 256                            "cylinder group %u corrupted - error in inode bitmap\n", cg);
 257                        err = -EIO;
 258                        goto failed;
 259                }
 260        }
 261        UFSD("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg);
 262        if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
 263                ubh_setbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
 264        else {
 265                ufs_panic (sb, "ufs_new_inode", "internal error");
 266                err = -EIO;
 267                goto failed;
 268        }
 269
 270        if (uspi->fs_magic == UFS2_MAGIC) {
 271                u32 initediblk = fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk);
 272
 273                if (bit + uspi->s_inopb > initediblk &&
 274                    initediblk < fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_niblk))
 275                        ufs2_init_inodes_chunk(sb, ucpi, ucg);
 276        }
 277
 278        fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1);
 279        uspi->cs_total.cs_nifree--;
 280        fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1);
 281        
 282        if (S_ISDIR(mode)) {
 283                fs32_add(sb, &ucg->cg_cs.cs_ndir, 1);
 284                uspi->cs_total.cs_ndir++;
 285                fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1);
 286        }
 287        ubh_mark_buffer_dirty (USPI_UBH(uspi));
 288        ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
 289        if (sb->s_flags & MS_SYNCHRONOUS)
 290                ubh_sync_block(UCPI_UBH(ucpi));
 291        ufs_mark_sb_dirty(sb);
 292
 293        inode->i_ino = cg * uspi->s_ipg + bit;
 294        inode_init_owner(inode, dir, mode);
 295        inode->i_blocks = 0;
 296        inode->i_generation = 0;
 297        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 298        ufsi->i_flags = UFS_I(dir)->i_flags;
 299        ufsi->i_lastfrag = 0;
 300        ufsi->i_shadow = 0;
 301        ufsi->i_osync = 0;
 302        ufsi->i_oeftflag = 0;
 303        ufsi->i_dir_start_lookup = 0;
 304        memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));
 305        insert_inode_hash(inode);
 306        mark_inode_dirty(inode);
 307
 308        if (uspi->fs_magic == UFS2_MAGIC) {
 309                struct buffer_head *bh;
 310                struct ufs2_inode *ufs2_inode;
 311
 312                /*
 313                 * setup birth date, we do it here because of there is no sense
 314                 * to hold it in struct ufs_inode_info, and lose 64 bit
 315                 */
 316                bh = sb_bread(sb, uspi->s_sbbase + ufs_inotofsba(inode->i_ino));
 317                if (!bh) {
 318                        ufs_warning(sb, "ufs_read_inode",
 319                                    "unable to read inode %lu\n",
 320                                    inode->i_ino);
 321                        err = -EIO;
 322                        goto fail_remove_inode;
 323                }
 324                lock_buffer(bh);
 325                ufs2_inode = (struct ufs2_inode *)bh->b_data;
 326                ufs2_inode += ufs_inotofsbo(inode->i_ino);
 327                ufs2_inode->ui_birthtime = cpu_to_fs64(sb, CURRENT_TIME.tv_sec);
 328                ufs2_inode->ui_birthnsec = cpu_to_fs32(sb, CURRENT_TIME.tv_nsec);
 329                mark_buffer_dirty(bh);
 330                unlock_buffer(bh);
 331                if (sb->s_flags & MS_SYNCHRONOUS)
 332                        sync_dirty_buffer(bh);
 333                brelse(bh);
 334        }
 335
 336        mutex_unlock(&sbi->s_lock);
 337
 338        UFSD("allocating inode %lu\n", inode->i_ino);
 339        UFSD("EXIT\n");
 340        return inode;
 341
 342fail_remove_inode:
 343        mutex_unlock(&sbi->s_lock);
 344        clear_nlink(inode);
 345        iput(inode);
 346        UFSD("EXIT (FAILED): err %d\n", err);
 347        return ERR_PTR(err);
 348failed:
 349        mutex_unlock(&sbi->s_lock);
 350        make_bad_inode(inode);
 351        iput (inode);
 352        UFSD("EXIT (FAILED): err %d\n", err);
 353        return ERR_PTR(err);
 354}
 355
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