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