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
  23 #include <linux/fs.h>
  24 #include <linux/ufs_fs.h>
  25 #include <linux/time.h>
  26 #include <linux/stat.h>
  27 #include <linux/string.h>
  28 #include <linux/quotaops.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/sched.h>
  31 #include <linux/bitops.h>
  32 #include <asm/byteorder.h>
  33
  34 #include "swab.h"
  35 #include "util.h"
  36
  37 #undef UFS_IALLOC_DEBUG
  38
  39 #ifdef UFS_IALLOC_DEBUG
  40 #define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x;
  41 #else
  42 #define UFSD(x)
  43 #endif
  44
  45 /*
  46  * NOTE! When we get the inode, we're the only people
  47  * that have access to it, and as such there are no
  48  * race conditions we have to worry about. The inode
  49  * is not on the hash-lists, and it cannot be reached
  50  * through the filesystem because the directory entry
  51  * has been deleted earlier.
  52  *
  53  * HOWEVER: we must make sure that we get no aliases,
  54  * which means that we have to call "clear_inode()"
  55  * _before_ we mark the inode not in use in the inode
  56  * bitmaps. Otherwise a newly created file might use
  57  * the same inode number (not actually the same pointer
  58  * though), and then we'd have two inodes sharing the
  59  * same inode number and space on the harddisk.
  60  */
  61 void ufs_free_inode (struct inode * inode)
  62 {
  63         struct super_block * sb;
  64         struct ufs_sb_private_info * uspi;
  65         struct ufs_super_block_first * usb1;
  66         struct ufs_cg_private_info * ucpi;
  67         struct ufs_cylinder_group * ucg;
  68         int is_directory;
  69         unsigned ino, cg, bit;
  70
  71         UFSD(("ENTER, ino %lu\n", inode->i_ino))
  72
  73         sb = inode->i_sb;
  74         uspi = UFS_SB(sb)->s_uspi;
  75         usb1 = ubh_get_usb_first(uspi);
  76
  77         ino = inode->i_ino;
  78
  79         lock_super (sb);
  80
  81         if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) {
  82                 ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino);
  83                 unlock_super (sb);
  84                 return;
  85         }
  86
  87         cg = ufs_inotocg (ino);
  88         bit = ufs_inotocgoff (ino);
  89         ucpi = ufs_load_cylinder (sb, cg);
  90         if (!ucpi) {
  91                 unlock_super (sb);
  92                 return;
  93         }
  94         ucg = ubh_get_ucg(UCPI_UBH);
  95         if (!ufs_cg_chkmagic(sb, ucg))
  96                 ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number");
  97
  98         ucg->cg_time = cpu_to_fs32(sb, get_seconds());
  99
 100         is_directory = S_ISDIR(inode->i_mode);
 101
 102         DQUOT_FREE_INODE(inode);
 103         DQUOT_DROP(inode);
 104
 105         clear_inode (inode);
 106
 107         if (ubh_isclr (UCPI_UBH, ucpi->c_iusedoff, bit))
 108                 ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino);
 109         else {
 110                 ubh_clrbit (UCPI_UBH, ucpi->c_iusedoff, bit);
 111                 if (ino < ucpi->c_irotor)
 112                         ucpi->c_irotor = ino;
 113                 fs32_add(sb, &ucg->cg_cs.cs_nifree, 1);
 114                 fs32_add(sb, &usb1->fs_cstotal.cs_nifree, 1);
 115                 fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1);
 116
 117                 if (is_directory) {
 118                         fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1);
 119                         fs32_sub(sb, &usb1->fs_cstotal.cs_ndir, 1);
 120                         fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1);
 121                 }
 122         }
 123
 124         ubh_mark_buffer_dirty (USPI_UBH);
 125         ubh_mark_buffer_dirty (UCPI_UBH);
 126         if (sb->s_flags & MS_SYNCHRONOUS) {
 127                 ubh_ll_rw_block (SWRITE, 1, (struct ufs_buffer_head **) &ucpi);
 128                 ubh_wait_on_buffer (UCPI_UBH);
 129         }
 130
 131         sb->s_dirt = 1;
 132         unlock_super (sb);
 133         UFSD(("EXIT\n"))
 134 }
 135
 136 /*
 137  * There are two policies for allocating an inode.  If the new inode is
 138  * a directory, then a forward search is made for a block group with both
 139  * free space and a low directory-to-inode ratio; if that fails, then of
 140  * the groups with above-average free space, that group with the fewest
 141  * directories already is chosen.
 142  *
 143  * For other inodes, search forward from the parent directory's block
 144  * group to find a free inode.
 145  */
 146 struct inode * ufs_new_inode(struct inode * dir, int mode)
 147 {
 148         struct super_block * sb;
 149         struct ufs_sb_info * sbi;
 150         struct ufs_sb_private_info * uspi;
 151         struct ufs_super_block_first * usb1;
 152         struct ufs_cg_private_info * ucpi;
 153         struct ufs_cylinder_group * ucg;
 154         struct inode * inode;
 155         unsigned cg, bit, i, j, start;
 156         struct ufs_inode_info *ufsi;
 157
 158         UFSD(("ENTER\n"))
 159
 160         /* Cannot create files in a deleted directory */
 161         if (!dir || !dir->i_nlink)
 162                 return ERR_PTR(-EPERM);
 163         sb = dir->i_sb;
 164         inode = new_inode(sb);
 165         if (!inode)
 166                 return ERR_PTR(-ENOMEM);
 167         ufsi = UFS_I(inode);
 168         sbi = UFS_SB(sb);
 169         uspi = sbi->s_uspi;
 170         usb1 = ubh_get_usb_first(uspi);
 171
 172         lock_super (sb);
 173
 174         /*
 175          * Try to place the inode in its parent directory
 176          */
 177         i = ufs_inotocg(dir->i_ino);
 178         if (sbi->fs_cs(i).cs_nifree) {
 179                 cg = i;
 180                 goto cg_found;
 181         }
 182
 183         /*
 184          * Use a quadratic hash to find a group with a free inode
 185          */
 186         for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
 187                 i += j;
 188                 if (i >= uspi->s_ncg)
 189                         i -= uspi->s_ncg;
 190                 if (sbi->fs_cs(i).cs_nifree) {
 191                         cg = i;
 192                         goto cg_found;
 193                 }
 194         }
 195
 196         /*
 197          * That failed: try linear search for a free inode
 198          */
 199         i = ufs_inotocg(dir->i_ino) + 1;
 200         for (j = 2; j < uspi->s_ncg; j++) {
 201                 i++;
 202                 if (i >= uspi->s_ncg)
 203                         i = 0;
 204                 if (sbi->fs_cs(i).cs_nifree) {
 205                         cg = i;
 206                         goto cg_found;
 207                 }
 208         }
 209
 210         goto failed;
 211
 212 cg_found:
 213         ucpi = ufs_load_cylinder (sb, cg);
 214         if (!ucpi)
 215                 goto failed;
 216         ucg = ubh_get_ucg(UCPI_UBH);
 217         if (!ufs_cg_chkmagic(sb, ucg))
 218                 ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");
 219
 220         start = ucpi->c_irotor;
 221         bit = ubh_find_next_zero_bit (UCPI_UBH, ucpi->c_iusedoff, uspi->s_ipg, start);
 222         if (!(bit < uspi->s_ipg)) {
 223                 bit = ubh_find_first_zero_bit (UCPI_UBH, ucpi->c_iusedoff, start);
 224                 if (!(bit < start)) {
 225                         ufs_error (sb, "ufs_new_inode",
 226                             "cylinder group %u corrupted - error in inode bitmap\n", cg);
 227                         goto failed;
 228                 }
 229         }
 230         UFSD(("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg))
 231         if (ubh_isclr (UCPI_UBH, ucpi->c_iusedoff, bit))
 232                 ubh_setbit (UCPI_UBH, ucpi->c_iusedoff, bit);
 233         else {
 234                 ufs_panic (sb, "ufs_new_inode", "internal error");
 235                 goto failed;
 236         }
 237
 238         fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1);
 239         fs32_sub(sb, &usb1->fs_cstotal.cs_nifree, 1);
 240         fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1);
 241
 242         if (S_ISDIR(mode)) {
 243                 fs32_add(sb, &ucg->cg_cs.cs_ndir, 1);
 244                 fs32_add(sb, &usb1->fs_cstotal.cs_ndir, 1);
 245                 fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1);
 246         }
 247
 248         ubh_mark_buffer_dirty (USPI_UBH);
 249         ubh_mark_buffer_dirty (UCPI_UBH);
 250         if (sb->s_flags & MS_SYNCHRONOUS) {
 251                 ubh_ll_rw_block (SWRITE, 1, (struct ufs_buffer_head **) &ucpi);
 252                 ubh_wait_on_buffer (UCPI_UBH);
 253         }
 254         sb->s_dirt = 1;
 255
 256         inode->i_mode = mode;
 257         inode->i_uid = current->fsuid;
 258         if (dir->i_mode & S_ISGID) {
 259                 inode->i_gid = dir->i_gid;
 260                 if (S_ISDIR(mode))
 261                         inode->i_mode |= S_ISGID;
 262         } else
 263                 inode->i_gid = current->fsgid;
 264
 265         inode->i_ino = cg * uspi->s_ipg + bit;
 266         inode->i_blksize = PAGE_SIZE;   /* This is the optimal IO size (for stat), not the fs block size */
 267         inode->i_blocks = 0;
 268         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 269         ufsi->i_flags = UFS_I(dir)->i_flags;
 270         ufsi->i_lastfrag = 0;
 271         ufsi->i_gen = 0;
 272         ufsi->i_shadow = 0;
 273         ufsi->i_osync = 0;
 274         ufsi->i_oeftflag = 0;
 275         memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));
 276
 277         insert_inode_hash(inode);
 278         mark_inode_dirty(inode);
 279
 280         unlock_super (sb);
 281
 282         if (DQUOT_ALLOC_INODE(inode)) {
 283                 DQUOT_DROP(inode);
 284                 inode->i_flags |= S_NOQUOTA;
 285                 inode->i_nlink = 0;
 286                 iput(inode);
 287                 return ERR_PTR(-EDQUOT);
 288         }
 289
 290         UFSD(("allocating inode %lu\n", inode->i_ino))
 291         UFSD(("EXIT\n"))
 292         return inode;
 293
 294 failed:
 295         unlock_super (sb);
 296         make_bad_inode(inode);
 297         iput (inode);
 298         UFSD(("EXIT (FAILED)\n"))
 299         return ERR_PTR(-ENOSPC);
 300 }