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_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         clear_inode (inode);
  98
  99         if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
 100                 ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino);
 101         else {
 102                 ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
 103                 if (ino < ucpi->c_irotor)
 104                         ucpi->c_irotor = ino;
 105                 fs32_add(sb, &ucg->cg_cs.cs_nifree, 1);
 106                 uspi->cs_total.cs_nifree++;
 107                 fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1);
 108
 109                 if (is_directory) {
 110                         fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1);
 111                         uspi->cs_total.cs_ndir--;
 112                         fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1);
 113                 }
 114         }
 115
 116         ubh_mark_buffer_dirty (USPI_UBH(uspi));
 117         ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
 118         if (sb->s_flags & MS_SYNCHRONOUS) {
 119                 ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
 120                 ubh_wait_on_buffer (UCPI_UBH(ucpi));
 121         }
 122
 123         sb->s_dirt = 1;
 124         unlock_super (sb);
 125         UFSD("EXIT\n");
 126 }
 127
 128 /*
 129  * Nullify new chunk of inodes,
 130  * BSD people also set ui_gen field of inode
 131  * during nullification, but we not care about
 132  * that because of linux ufs do not support NFS
 133  */
 134 static void ufs2_init_inodes_chunk(struct super_block *sb,
 135                                    struct ufs_cg_private_info *ucpi,
 136                                    struct ufs_cylinder_group *ucg)
 137 {
 138         struct buffer_head *bh;
 139         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 140         sector_t beg = uspi->s_sbbase +
 141                 ufs_inotofsba(ucpi->c_cgx * uspi->s_ipg +
 142                               fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk));
 143         sector_t end = beg + uspi->s_fpb;
 144
 145         UFSD("ENTER cgno %d\n", ucpi->c_cgx);
 146
 147         for (; beg < end; ++beg) {
 148                 bh = sb_getblk(sb, beg);
 149                 lock_buffer(bh);
 150                 memset(bh->b_data, 0, sb->s_blocksize);
 151                 set_buffer_uptodate(bh);
 152                 mark_buffer_dirty(bh);
 153                 unlock_buffer(bh);
 154                 if (sb->s_flags & MS_SYNCHRONOUS)
 155                         sync_dirty_buffer(bh);
 156                 brelse(bh);
 157         }
 158
 159         fs32_add(sb, &ucg->cg_u.cg_u2.cg_initediblk, uspi->s_inopb);
 160         ubh_mark_buffer_dirty(UCPI_UBH(ucpi));
 161         if (sb->s_flags & MS_SYNCHRONOUS) {
 162                 ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
 163                 ubh_wait_on_buffer(UCPI_UBH(ucpi));
 164         }
 165
 166         UFSD("EXIT\n");
 167 }
 168
 169 /*
 170  * There are two policies for allocating an inode.  If the new inode is
 171  * a directory, then a forward search is made for a block group with both
 172  * free space and a low directory-to-inode ratio; if that fails, then of
 173  * the groups with above-average free space, that group with the fewest
 174  * directories already is chosen.
 175  *
 176  * For other inodes, search forward from the parent directory's block
 177  * group to find a free inode.
 178  */
 179 struct inode * ufs_new_inode(struct inode * dir, int mode)
 180 {
 181         struct super_block * sb;
 182         struct ufs_sb_info * sbi;
 183         struct ufs_sb_private_info * uspi;
 184         struct ufs_super_block_first * usb1;
 185         struct ufs_cg_private_info * ucpi;
 186         struct ufs_cylinder_group * ucg;
 187         struct inode * inode;
 188         unsigned cg, bit, i, j, start;
 189         struct ufs_inode_info *ufsi;
 190         int err = -ENOSPC;
 191
 192         UFSD("ENTER\n");
 193
 194         /* Cannot create files in a deleted directory */
 195         if (!dir || !dir->i_nlink)
 196                 return ERR_PTR(-EPERM);
 197         sb = dir->i_sb;
 198         inode = new_inode(sb);
 199         if (!inode)
 200                 return ERR_PTR(-ENOMEM);
 201         ufsi = UFS_I(inode);
 202         sbi = UFS_SB(sb);
 203         uspi = sbi->s_uspi;
 204         usb1 = ubh_get_usb_first(uspi);
 205
 206         lock_super (sb);
 207
 208         /*
 209          * Try to place the inode in its parent directory
 210          */
 211         i = ufs_inotocg(dir->i_ino);
 212         if (sbi->fs_cs(i).cs_nifree) {
 213                 cg = i;
 214                 goto cg_found;
 215         }
 216
 217         /*
 218          * Use a quadratic hash to find a group with a free inode
 219          */
 220         for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
 221                 i += j;
 222                 if (i >= uspi->s_ncg)
 223                         i -= uspi->s_ncg;
 224                 if (sbi->fs_cs(i).cs_nifree) {
 225                         cg = i;
 226                         goto cg_found;
 227                 }
 228         }
 229
 230         /*
 231          * That failed: try linear search for a free inode
 232          */
 233         i = ufs_inotocg(dir->i_ino) + 1;
 234         for (j = 2; j < uspi->s_ncg; j++) {
 235                 i++;
 236                 if (i >= uspi->s_ncg)
 237                         i = 0;
 238                 if (sbi->fs_cs(i).cs_nifree) {
 239                         cg = i;
 240                         goto cg_found;
 241                 }
 242         }
 243
 244         goto failed;
 245
 246 cg_found:
 247         ucpi = ufs_load_cylinder (sb, cg);
 248         if (!ucpi) {
 249                 err = -EIO;
 250                 goto failed;
 251         }
 252         ucg = ubh_get_ucg(UCPI_UBH(ucpi));
 253         if (!ufs_cg_chkmagic(sb, ucg))
 254                 ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");
 255
 256         start = ucpi->c_irotor;
 257         bit = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, uspi->s_ipg, start);
 258         if (!(bit < uspi->s_ipg)) {
 259                 bit = ubh_find_first_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, start);
 260                 if (!(bit < start)) {
 261                         ufs_error (sb, "ufs_new_inode",
 262                             "cylinder group %u corrupted - error in inode bitmap\n", cg);
 263                         err = -EIO;
 264                         goto failed;
 265                 }
 266         }
 267         UFSD("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg);
 268         if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
 269                 ubh_setbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
 270         else {
 271                 ufs_panic (sb, "ufs_new_inode", "internal error");
 272                 err = -EIO;
 273                 goto failed;
 274         }
 275
 276         if (uspi->fs_magic == UFS2_MAGIC) {
 277                 u32 initediblk = fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk);
 278
 279                 if (bit + uspi->s_inopb > initediblk &&
 280                     initediblk < fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_niblk))
 281                         ufs2_init_inodes_chunk(sb, ucpi, ucg);
 282         }
 283
 284         fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1);
 285         uspi->cs_total.cs_nifree--;
 286         fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1);
 287
 288         if (S_ISDIR(mode)) {
 289                 fs32_add(sb, &ucg->cg_cs.cs_ndir, 1);
 290                 uspi->cs_total.cs_ndir++;
 291                 fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1);
 292         }
 293         ubh_mark_buffer_dirty (USPI_UBH(uspi));
 294         ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
 295         if (sb->s_flags & MS_SYNCHRONOUS) {
 296                 ubh_ll_rw_block(SWRITE, UCPI_UBH(ucpi));
 297                 ubh_wait_on_buffer (UCPI_UBH(ucpi));
 298         }
 299         sb->s_dirt = 1;
 300
 301         inode->i_ino = cg * uspi->s_ipg + bit;
 302         inode_init_owner(inode, dir, mode);
 303         inode->i_blocks = 0;
 304         inode->i_generation = 0;
 305         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 306         ufsi->i_flags = UFS_I(dir)->i_flags;
 307         ufsi->i_lastfrag = 0;
 308         ufsi->i_shadow = 0;
 309         ufsi->i_osync = 0;
 310         ufsi->i_oeftflag = 0;
 311         ufsi->i_dir_start_lookup = 0;
 312         memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));
 313         insert_inode_hash(inode);
 314         mark_inode_dirty(inode);
 315
 316         if (uspi->fs_magic == UFS2_MAGIC) {
 317                 struct buffer_head *bh;
 318                 struct ufs2_inode *ufs2_inode;
 319
 320                 /*
 321                  * setup birth date, we do it here because of there is no sense
 322                  * to hold it in struct ufs_inode_info, and lose 64 bit
 323                  */
 324                 bh = sb_bread(sb, uspi->s_sbbase + ufs_inotofsba(inode->i_ino));
 325                 if (!bh) {
 326                         ufs_warning(sb, "ufs_read_inode",
 327                                     "unable to read inode %lu\n",
 328                                     inode->i_ino);
 329                         err = -EIO;
 330                         goto fail_remove_inode;
 331                 }
 332                 lock_buffer(bh);
 333                 ufs2_inode = (struct ufs2_inode *)bh->b_data;
 334                 ufs2_inode += ufs_inotofsbo(inode->i_ino);
 335                 ufs2_inode->ui_birthtime = cpu_to_fs64(sb, CURRENT_TIME.tv_sec);
 336                 ufs2_inode->ui_birthnsec = cpu_to_fs32(sb, CURRENT_TIME.tv_nsec);
 337                 mark_buffer_dirty(bh);
 338                 unlock_buffer(bh);
 339                 if (sb->s_flags & MS_SYNCHRONOUS)
 340                         sync_dirty_buffer(bh);
 341                 brelse(bh);
 342         }
 343
 344         unlock_super (sb);
 345
 346         UFSD("allocating inode %lu\n", inode->i_ino);
 347         UFSD("EXIT\n");
 348         return inode;
 349
 350 fail_remove_inode:
 351         unlock_super(sb);
 352         inode->i_nlink = 0;
 353         iput(inode);
 354         UFSD("EXIT (FAILED): err %d\n", err);
 355         return ERR_PTR(err);
 356 failed:
 357         unlock_super (sb);
 358         make_bad_inode(inode);
 359         iput (inode);
 360         UFSD("EXIT (FAILED): err %d\n", err);
 361         return ERR_PTR(err);
 362 }