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/quotaops.h>
  31 #include <linux/buffer_head.h>
  32 #include <linux/sched.h>
  33 #include <linux/bitops.h>
  34 #include <asm/byteorder.h>
  35
  36 #include "ufs_fs.h"
  37 #include "ufs.h"
  38 #include "swab.h"
  39 #include "util.h"
  40
  41 /*
  42  * NOTE! When we get the inode, we're the only people
  43  * that have access to it, and as such there are no
  44  * race conditions we have to worry about. The inode
  45  * is not on the hash-lists, and it cannot be reached
  46  * through the filesystem because the directory entry
  47  * has been deleted earlier.
  48  *
  49  * HOWEVER: we must make sure that we get no aliases,
  50  * which means that we have to call "clear_inode()"
  51  * _before_ we mark the inode not in use in the inode
  52  * bitmaps. Otherwise a newly created file might use
  53  * the same inode number (not actually the same pointer
  54  * though), and then we'd have two inodes sharing the
  55  * same inode number and space on the harddisk.
  56  */
  57 void ufs_free_inode (struct inode * inode)
  58 {
  59         struct super_block * sb;
  60         struct ufs_sb_private_info * uspi;
  61         struct ufs_super_block_first * usb1;
  62         struct ufs_cg_private_info * ucpi;
  63         struct ufs_cylinder_group * ucg;
  64         int is_directory;
  65         unsigned ino, cg, bit;
  66
  67         UFSD("ENTER, ino %lu\n", inode->i_ino);
  68
  69         sb = inode->i_sb;
  70         uspi = UFS_SB(sb)->s_uspi;
  71         usb1 = ubh_get_usb_first(uspi);
  72
  73         ino = inode->i_ino;
  74
  75         lock_super (sb);
  76
  77         if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) {
  78                 ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino);
  79                 unlock_super (sb);
  80                 return;
  81         }
  82
  83         cg = ufs_inotocg (ino);
  84         bit = ufs_inotocgoff (ino);
  85         ucpi = ufs_load_cylinder (sb, cg);
  86         if (!ucpi) {
  87                 unlock_super (sb);
  88                 return;
  89         }
  90         ucg = ubh_get_ucg(UCPI_UBH(ucpi));
  91         if (!ufs_cg_chkmagic(sb, ucg))
  92                 ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number");
  93
  94         ucg->cg_time = cpu_to_fs32(sb, get_seconds());
  95
  96         is_directory = S_ISDIR(inode->i_mode);
  97
  98         dquot_free_inode(inode);
  99         dquot_drop(inode);
 100
 101         clear_inode (inode);
 102
 103         if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
 104                 ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino);
 105         else {
 106                 ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
 107                 if (ino < ucpi->c_irotor)
 108                         ucpi->c_irotor = ino;
 109                 fs32_add(sb, &ucg->cg_cs.cs_nifree, 1);
 110                 uspi->cs_total.cs_nifree++;
 111                 fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1);
 112
 113                 if (is_directory) {
 114                         fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1);
 115                         uspi->cs_total.cs_ndir--;
 116                         fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1);
 117                 }
 118         }
 119
 120         ubh_mark_buffer_dirty (USPI_UBH(uspi));
 121         ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
 122         if (sb->s_flags & MS_SYNCHRONOUS) {
 123                 ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
 124                 ubh_wait_on_buffer (UCPI_UBH(ucpi));
 125         }
 126
 127         sb->s_dirt = 1;
 128         unlock_super (sb);
 129         UFSD("EXIT\n");
 130 }
 131
 132 /*
 133  * Nullify new chunk of inodes,
 134  * BSD people also set ui_gen field of inode
 135  * during nullification, but we not care about
 136  * that because of linux ufs do not support NFS
 137  */
 138 static void ufs2_init_inodes_chunk(struct super_block *sb,
 139                                    struct ufs_cg_private_info *ucpi,
 140                                    struct ufs_cylinder_group *ucg)
 141 {
 142         struct buffer_head *bh;
 143         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 144         sector_t beg = uspi->s_sbbase +
 145                 ufs_inotofsba(ucpi->c_cgx * uspi->s_ipg +
 146                               fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk));
 147         sector_t end = beg + uspi->s_fpb;
 148
 149         UFSD("ENTER cgno %d\n", ucpi->c_cgx);
 150
 151         for (; beg < end; ++beg) {
 152                 bh = sb_getblk(sb, beg);
 153                 lock_buffer(bh);
 154                 memset(bh->b_data, 0, sb->s_blocksize);
 155                 set_buffer_uptodate(bh);
 156                 mark_buffer_dirty(bh);
 157                 unlock_buffer(bh);
 158                 if (sb->s_flags & MS_SYNCHRONOUS)
 159                         sync_dirty_buffer(bh);
 160                 brelse(bh);
 161         }
 162
 163         fs32_add(sb, &ucg->cg_u.cg_u2.cg_initediblk, uspi->s_inopb);
 164         ubh_mark_buffer_dirty(UCPI_UBH(ucpi));
 165         if (sb->s_flags & MS_SYNCHRONOUS) {
 166                 ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
 167                 ubh_wait_on_buffer(UCPI_UBH(ucpi));
 168         }
 169
 170         UFSD("EXIT\n");
 171 }
 172
 173 /*
 174  * There are two policies for allocating an inode.  If the new inode is
 175  * a directory, then a forward search is made for a block group with both
 176  * free space and a low directory-to-inode ratio; if that fails, then of
 177  * the groups with above-average free space, that group with the fewest
 178  * directories already is chosen.
 179  *
 180  * For other inodes, search forward from the parent directory's block
 181  * group to find a free inode.
 182  */
 183 struct inode * ufs_new_inode(struct inode * dir, int mode)
 184 {
 185         struct super_block * sb;
 186         struct ufs_sb_info * sbi;
 187         struct ufs_sb_private_info * uspi;
 188         struct ufs_super_block_first * usb1;
 189         struct ufs_cg_private_info * ucpi;
 190         struct ufs_cylinder_group * ucg;
 191         struct inode * inode;
 192         unsigned cg, bit, i, j, start;
 193         struct ufs_inode_info *ufsi;
 194         int err = -ENOSPC;
 195
 196         UFSD("ENTER\n");
 197
 198         /* Cannot create files in a deleted directory */
 199         if (!dir || !dir->i_nlink)
 200                 return ERR_PTR(-EPERM);
 201         sb = dir->i_sb;
 202         inode = new_inode(sb);
 203         if (!inode)
 204                 return ERR_PTR(-ENOMEM);
 205         ufsi = UFS_I(inode);
 206         sbi = UFS_SB(sb);
 207         uspi = sbi->s_uspi;
 208         usb1 = ubh_get_usb_first(uspi);
 209
 210         lock_super (sb);
 211
 212         /*
 213          * Try to place the inode in its parent directory
 214          */
 215         i = ufs_inotocg(dir->i_ino);
 216         if (sbi->fs_cs(i).cs_nifree) {
 217                 cg = i;
 218                 goto cg_found;
 219         }
 220
 221         /*
 222          * Use a quadratic hash to find a group with a free inode
 223          */
 224         for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
 225                 i += j;
 226                 if (i >= uspi->s_ncg)
 227                         i -= uspi->s_ncg;
 228                 if (sbi->fs_cs(i).cs_nifree) {
 229                         cg = i;
 230                         goto cg_found;
 231                 }
 232         }
 233
 234         /*
 235          * That failed: try linear search for a free inode
 236          */
 237         i = ufs_inotocg(dir->i_ino) + 1;
 238         for (j = 2; j < uspi->s_ncg; j++) {
 239                 i++;
 240                 if (i >= uspi->s_ncg)
 241                         i = 0;
 242                 if (sbi->fs_cs(i).cs_nifree) {
 243                         cg = i;
 244                         goto cg_found;
 245                 }
 246         }
 247
 248         goto failed;
 249
 250 cg_found:
 251         ucpi = ufs_load_cylinder (sb, cg);
 252         if (!ucpi) {
 253                 err = -EIO;
 254                 goto failed;
 255         }
 256         ucg = ubh_get_ucg(UCPI_UBH(ucpi));
 257         if (!ufs_cg_chkmagic(sb, ucg))
 258                 ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");
 259
 260         start = ucpi->c_irotor;
 261         bit = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, uspi->s_ipg, start);
 262         if (!(bit < uspi->s_ipg)) {
 263                 bit = ubh_find_first_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, start);
 264                 if (!(bit < start)) {
 265                         ufs_error (sb, "ufs_new_inode",
 266                             "cylinder group %u corrupted - error in inode bitmap\n", cg);
 267                         err = -EIO;
 268                         goto failed;
 269                 }
 270         }
 271         UFSD("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg);
 272         if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
 273                 ubh_setbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
 274         else {
 275                 ufs_panic (sb, "ufs_new_inode", "internal error");
 276                 err = -EIO;
 277                 goto failed;
 278         }
 279
 280         if (uspi->fs_magic == UFS2_MAGIC) {
 281                 u32 initediblk = fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk);
 282
 283                 if (bit + uspi->s_inopb > initediblk &&
 284                     initediblk < fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_niblk))
 285                         ufs2_init_inodes_chunk(sb, ucpi, ucg);
 286         }
 287
 288         fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1);
 289         uspi->cs_total.cs_nifree--;
 290         fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1);
 291
 292         if (S_ISDIR(mode)) {
 293                 fs32_add(sb, &ucg->cg_cs.cs_ndir, 1);
 294                 uspi->cs_total.cs_ndir++;
 295                 fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1);
 296         }
 297         ubh_mark_buffer_dirty (USPI_UBH(uspi));
 298         ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
 299         if (sb->s_flags & MS_SYNCHRONOUS) {
 300                 ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
 301                 ubh_wait_on_buffer (UCPI_UBH(ucpi));
 302         }
 303         sb->s_dirt = 1;
 304
 305         inode->i_ino = cg * uspi->s_ipg + bit;
 306         inode->i_mode = mode;
 307         inode->i_uid = current_fsuid();
 308         if (dir->i_mode & S_ISGID) {
 309                 inode->i_gid = dir->i_gid;
 310                 if (S_ISDIR(mode))
 311                         inode->i_mode |= S_ISGID;
 312         } else
 313                 inode->i_gid = current_fsgid();
 314
 315         inode->i_blocks = 0;
 316         inode->i_generation = 0;
 317         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 318         ufsi->i_flags = UFS_I(dir)->i_flags;
 319         ufsi->i_lastfrag = 0;
 320         ufsi->i_shadow = 0;
 321         ufsi->i_osync = 0;
 322         ufsi->i_oeftflag = 0;
 323         ufsi->i_dir_start_lookup = 0;
 324         memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));
 325         insert_inode_hash(inode);
 326         mark_inode_dirty(inode);
 327
 328         if (uspi->fs_magic == UFS2_MAGIC) {
 329                 struct buffer_head *bh;
 330                 struct ufs2_inode *ufs2_inode;
 331
 332                 /*
 333                  * setup birth date, we do it here because of there is no sense
 334                  * to hold it in struct ufs_inode_info, and lose 64 bit
 335                  */
 336                 bh = sb_bread(sb, uspi->s_sbbase + ufs_inotofsba(inode->i_ino));
 337                 if (!bh) {
 338                         ufs_warning(sb, "ufs_read_inode",
 339                                     "unable to read inode %lu\n",
 340                                     inode->i_ino);
 341                         err = -EIO;
 342                         goto fail_remove_inode;
 343                 }
 344                 lock_buffer(bh);
 345                 ufs2_inode = (struct ufs2_inode *)bh->b_data;
 346                 ufs2_inode += ufs_inotofsbo(inode->i_ino);
 347                 ufs2_inode->ui_birthtime = cpu_to_fs64(sb, CURRENT_TIME.tv_sec);
 348                 ufs2_inode->ui_birthnsec = cpu_to_fs32(sb, CURRENT_TIME.tv_nsec);
 349                 mark_buffer_dirty(bh);
 350                 unlock_buffer(bh);
 351                 if (sb->s_flags & MS_SYNCHRONOUS)
 352                         sync_dirty_buffer(bh);
 353                 brelse(bh);
 354         }
 355
 356         unlock_super (sb);
 357
 358         dquot_initialize(inode);
 359         err = dquot_alloc_inode(inode);
 360         if (err) {
 361                 dquot_drop(inode);
 362                 goto fail_without_unlock;
 363         }
 364
 365         UFSD("allocating inode %lu\n", inode->i_ino);
 366         UFSD("EXIT\n");
 367         return inode;
 368
 369 fail_remove_inode:
 370         unlock_super(sb);
 371 fail_without_unlock:
 372         inode->i_flags |= S_NOQUOTA;
 373         inode->i_nlink = 0;
 374         iput(inode);
 375         UFSD("EXIT (FAILED): err %d\n", err);
 376         return ERR_PTR(err);
 377 failed:
 378         unlock_super (sb);
 379         make_bad_inode(inode);
 380         iput (inode);
 381         UFSD("EXIT (FAILED): err %d\n", err);
 382         return ERR_PTR(err);
 383 }