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