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_UBH); 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_UBH); 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 } 301