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_cg_private_info * ucpi; 61 struct ufs_cylinder_group * ucg; 62 int is_directory; 63 unsigned ino, cg, bit; 64 65 UFSD("ENTER, ino %lu\n", inode->i_ino); 66 67 sb = inode->i_sb; 68 uspi = UFS_SB(sb)->s_uspi; 69 70 ino = inode->i_ino; 71 72 lock_ufs(sb); 73 74 if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) { 75 ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino); 76 unlock_ufs(sb); 77 return; 78 } 79 80 cg = ufs_inotocg (ino); 81 bit = ufs_inotocgoff (ino); 82 ucpi = ufs_load_cylinder (sb, cg); 83 if (!ucpi) { 84 unlock_ufs(sb); 85 return; 86 } 87 ucg = ubh_get_ucg(UCPI_UBH(ucpi)); 88 if (!ufs_cg_chkmagic(sb, ucg)) 89 ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number"); 90 91 ucg->cg_time = cpu_to_fs32(sb, get_seconds()); 92 93 is_directory = S_ISDIR(inode->i_mode); 94 95 if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit)) 96 ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino); 97 else { 98 ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit); 99 if (ino < ucpi->c_irotor) 100 ucpi->c_irotor = ino; 101 fs32_add(sb, &ucg->cg_cs.cs_nifree, 1); 102 uspi->cs_total.cs_nifree++; 103 fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1); 104 105 if (is_directory) { 106 fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1); 107 uspi->cs_total.cs_ndir--; 108 fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1); 109 } 110 } 111 112 ubh_mark_buffer_dirty (USPI_UBH(uspi)); 113 ubh_mark_buffer_dirty (UCPI_UBH(ucpi)); 114 if (sb->s_flags & MS_SYNCHRONOUS) 115 ubh_sync_block(UCPI_UBH(ucpi)); 116 117 ufs_mark_sb_dirty(sb); 118 unlock_ufs(sb); 119 UFSD("EXIT\n"); 120 } 121 122 /* 123 * Nullify new chunk of inodes, 124 * BSD people also set ui_gen field of inode 125 * during nullification, but we not care about 126 * that because of linux ufs do not support NFS 127 */ 128 static void ufs2_init_inodes_chunk(struct super_block *sb, 129 struct ufs_cg_private_info *ucpi, 130 struct ufs_cylinder_group *ucg) 131 { 132 struct buffer_head *bh; 133 struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi; 134 sector_t beg = uspi->s_sbbase + 135 ufs_inotofsba(ucpi->c_cgx * uspi->s_ipg + 136 fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk)); 137 sector_t end = beg + uspi->s_fpb; 138 139 UFSD("ENTER cgno %d\n", ucpi->c_cgx); 140 141 for (; beg < end; ++beg) { 142 bh = sb_getblk(sb, beg); 143 lock_buffer(bh); 144 memset(bh->b_data, 0, sb->s_blocksize); 145 set_buffer_uptodate(bh); 146 mark_buffer_dirty(bh); 147 unlock_buffer(bh); 148 if (sb->s_flags & MS_SYNCHRONOUS) 149 sync_dirty_buffer(bh); 150 brelse(bh); 151 } 152 153 fs32_add(sb, &ucg->cg_u.cg_u2.cg_initediblk, uspi->s_inopb); 154 ubh_mark_buffer_dirty(UCPI_UBH(ucpi)); 155 if (sb->s_flags & MS_SYNCHRONOUS) 156 ubh_sync_block(UCPI_UBH(ucpi)); 157 158 UFSD("EXIT\n"); 159 } 160 161 /* 162 * There are two policies for allocating an inode. If the new inode is 163 * a directory, then a forward search is made for a block group with both 164 * free space and a low directory-to-inode ratio; if that fails, then of 165 * the groups with above-average free space, that group with the fewest 166 * directories already is chosen. 167 * 168 * For other inodes, search forward from the parent directory's block 169 * group to find a free inode. 170 */ 171 struct inode *ufs_new_inode(struct inode *dir, umode_t mode) 172 { 173 struct super_block * sb; 174 struct ufs_sb_info * sbi; 175 struct ufs_sb_private_info * uspi; 176 struct ufs_cg_private_info * ucpi; 177 struct ufs_cylinder_group * ucg; 178 struct inode * inode; 179 unsigned cg, bit, i, j, start; 180 struct ufs_inode_info *ufsi; 181 int err = -ENOSPC; 182 183 UFSD("ENTER\n"); 184 185 /* Cannot create files in a deleted directory */ 186 if (!dir || !dir->i_nlink) 187 return ERR_PTR(-EPERM); 188 sb = dir->i_sb; 189 inode = new_inode(sb); 190 if (!inode) 191 return ERR_PTR(-ENOMEM); 192 ufsi = UFS_I(inode); 193 sbi = UFS_SB(sb); 194 uspi = sbi->s_uspi; 195 196 lock_ufs(sb); 197 198 /* 199 * Try to place the inode in its parent directory 200 */ 201 i = ufs_inotocg(dir->i_ino); 202 if (sbi->fs_cs(i).cs_nifree) { 203 cg = i; 204 goto cg_found; 205 } 206 207 /* 208 * Use a quadratic hash to find a group with a free inode 209 */ 210 for ( j = 1; j < uspi->s_ncg; j <<= 1 ) { 211 i += j; 212 if (i >= uspi->s_ncg) 213 i -= uspi->s_ncg; 214 if (sbi->fs_cs(i).cs_nifree) { 215 cg = i; 216 goto cg_found; 217 } 218 } 219 220 /* 221 * That failed: try linear search for a free inode 222 */ 223 i = ufs_inotocg(dir->i_ino) + 1; 224 for (j = 2; j < uspi->s_ncg; j++) { 225 i++; 226 if (i >= uspi->s_ncg) 227 i = 0; 228 if (sbi->fs_cs(i).cs_nifree) { 229 cg = i; 230 goto cg_found; 231 } 232 } 233 234 goto failed; 235 236 cg_found: 237 ucpi = ufs_load_cylinder (sb, cg); 238 if (!ucpi) { 239 err = -EIO; 240 goto failed; 241 } 242 ucg = ubh_get_ucg(UCPI_UBH(ucpi)); 243 if (!ufs_cg_chkmagic(sb, ucg)) 244 ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number"); 245 246 start = ucpi->c_irotor; 247 bit = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, uspi->s_ipg, start); 248 if (!(bit < uspi->s_ipg)) { 249 bit = ubh_find_first_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, start); 250 if (!(bit < start)) { 251 ufs_error (sb, "ufs_new_inode", 252 "cylinder group %u corrupted - error in inode bitmap\n", cg); 253 err = -EIO; 254 goto failed; 255 } 256 } 257 UFSD("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg); 258 if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit)) 259 ubh_setbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit); 260 else { 261 ufs_panic (sb, "ufs_new_inode", "internal error"); 262 err = -EIO; 263 goto failed; 264 } 265 266 if (uspi->fs_magic == UFS2_MAGIC) { 267 u32 initediblk = fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk); 268 269 if (bit + uspi->s_inopb > initediblk && 270 initediblk < fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_niblk)) 271 ufs2_init_inodes_chunk(sb, ucpi, ucg); 272 } 273 274 fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1); 275 uspi->cs_total.cs_nifree--; 276 fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1); 277 278 if (S_ISDIR(mode)) { 279 fs32_add(sb, &ucg->cg_cs.cs_ndir, 1); 280 uspi->cs_total.cs_ndir++; 281 fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1); 282 } 283 ubh_mark_buffer_dirty (USPI_UBH(uspi)); 284 ubh_mark_buffer_dirty (UCPI_UBH(ucpi)); 285 if (sb->s_flags & MS_SYNCHRONOUS) 286 ubh_sync_block(UCPI_UBH(ucpi)); 287 ufs_mark_sb_dirty(sb); 288 289 inode->i_ino = cg * uspi->s_ipg + bit; 290 inode_init_owner(inode, dir, mode); 291 inode->i_blocks = 0; 292 inode->i_generation = 0; 293 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC; 294 ufsi->i_flags = UFS_I(dir)->i_flags; 295 ufsi->i_lastfrag = 0; 296 ufsi->i_shadow = 0; 297 ufsi->i_osync = 0; 298 ufsi->i_oeftflag = 0; 299 ufsi->i_dir_start_lookup = 0; 300 memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1)); 301 if (insert_inode_locked(inode) < 0) { 302 err = -EIO; 303 goto failed; 304 } 305 mark_inode_dirty(inode); 306 307 if (uspi->fs_magic == UFS2_MAGIC) { 308 struct buffer_head *bh; 309 struct ufs2_inode *ufs2_inode; 310 311 /* 312 * setup birth date, we do it here because of there is no sense 313 * to hold it in struct ufs_inode_info, and lose 64 bit 314 */ 315 bh = sb_bread(sb, uspi->s_sbbase + ufs_inotofsba(inode->i_ino)); 316 if (!bh) { 317 ufs_warning(sb, "ufs_read_inode", 318 "unable to read inode %lu\n", 319 inode->i_ino); 320 err = -EIO; 321 goto fail_remove_inode; 322 } 323 lock_buffer(bh); 324 ufs2_inode = (struct ufs2_inode *)bh->b_data; 325 ufs2_inode += ufs_inotofsbo(inode->i_ino); 326 ufs2_inode->ui_birthtime = cpu_to_fs64(sb, CURRENT_TIME.tv_sec); 327 ufs2_inode->ui_birthnsec = cpu_to_fs32(sb, CURRENT_TIME.tv_nsec); 328 mark_buffer_dirty(bh); 329 unlock_buffer(bh); 330 if (sb->s_flags & MS_SYNCHRONOUS) 331 sync_dirty_buffer(bh); 332 brelse(bh); 333 } 334 unlock_ufs(sb); 335 336 UFSD("allocating inode %lu\n", inode->i_ino); 337 UFSD("EXIT\n"); 338 return inode; 339 340 fail_remove_inode: 341 unlock_ufs(sb); 342 clear_nlink(inode); 343 unlock_new_inode(inode); 344 iput(inode); 345 UFSD("EXIT (FAILED): err %d\n", err); 346 return ERR_PTR(err); 347 failed: 348 unlock_ufs(sb); 349 make_bad_inode(inode); 350 iput (inode); 351 UFSD("EXIT (FAILED): err %d\n", err); 352 return ERR_PTR(err); 353 } 354