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 } 363