1/* 2 * linux/fs/ufs/namei.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/namei.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 * from 18 * 19 * linux/fs/minix/namei.c 20 * 21 * Copyright (C) 1991, 1992 Linus Torvalds 22 * 23 * Big-endian to little-endian byte-swapping/bitmaps by 24 * David S. Miller (davem@caip.rutgers.edu), 1995 25 */ 26 27#include <linux/sched.h> 28#include <linux/fs.h> 29#include <linux/ufs_fs.h> 30 31#undef UFS_NAMEI_DEBUG 32 33#ifdef UFS_NAMEI_DEBUG 34#define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x; 35#else 36#define UFSD(x) 37#endif 38 39static inline void ufs_inc_count(struct inode *inode) 40{ 41 inode->i_nlink++; 42 mark_inode_dirty(inode); 43} 44 45static inline void ufs_dec_count(struct inode *inode) 46{ 47 inode->i_nlink--; 48 mark_inode_dirty(inode); 49} 50 51static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode) 52{ 53 int err = ufs_add_link(dentry, inode); 54 if (!err) { 55 d_instantiate(dentry, inode); 56 return 0; 57 } 58 ufs_dec_count(inode); 59 iput(inode); 60 return err; 61} 62 63static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry) 64{ 65 struct inode * inode = NULL; 66 ino_t ino; 67 68 if (dentry->d_name.len > UFS_MAXNAMLEN) 69 return ERR_PTR(-ENAMETOOLONG); 70 71 ino = ufs_inode_by_name(dir, dentry); 72 if (ino) { 73 inode = iget(dir->i_sb, ino); 74 if (!inode) 75 return ERR_PTR(-EACCES); 76 } 77 d_add(dentry, inode); 78 return NULL; 79} 80 81/* 82 * By the time this is called, we already have created 83 * the directory cache entry for the new file, but it 84 * is so far negative - it has no inode. 85 * 86 * If the create succeeds, we fill in the inode information 87 * with d_instantiate(). 88 */ 89static int ufs_create (struct inode * dir, struct dentry * dentry, int mode) 90{ 91 struct inode * inode = ufs_new_inode(dir, mode); 92 int err = PTR_ERR(inode); 93 if (!IS_ERR(inode)) { 94 inode->i_op = &ufs_file_inode_operations; 95 inode->i_fop = &ufs_file_operations; 96 inode->i_mapping->a_ops = &ufs_aops; 97 mark_inode_dirty(inode); 98 err = ufs_add_nondir(dentry, inode); 99 } 100 return err; 101} 102 103static int ufs_mknod (struct inode * dir, struct dentry *dentry, int mode, int rdev) 104{ 105 struct inode * inode = ufs_new_inode(dir, mode); 106 int err = PTR_ERR(inode); 107 if (!IS_ERR(inode)) { 108 init_special_inode(inode, mode, rdev); 109 mark_inode_dirty(inode); 110 err = ufs_add_nondir(dentry, inode); 111 } 112 return err; 113} 114 115static int ufs_symlink (struct inode * dir, struct dentry * dentry, 116 const char * symname) 117{ 118 struct super_block * sb = dir->i_sb; 119 int err = -ENAMETOOLONG; 120 unsigned l = strlen(symname)+1; 121 struct inode * inode; 122 123 if (l > sb->s_blocksize) 124 goto out; 125 126 inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO); 127 err = PTR_ERR(inode); 128 if (IS_ERR(inode)) 129 goto out; 130 131 if (l > sb->u.ufs_sb.s_uspi->s_maxsymlinklen) { 132 /* slow symlink */ 133 inode->i_op = &page_symlink_inode_operations; 134 inode->i_mapping->a_ops = &ufs_aops; 135 err = block_symlink(inode, symname, l); 136 if (err) 137 goto out_fail; 138 } else { 139 /* fast symlink */ 140 inode->i_op = &ufs_fast_symlink_inode_operations; 141 memcpy((char*)&inode->u.ufs_i.i_u1.i_data,symname,l); 142 inode->i_size = l-1; 143 } 144 mark_inode_dirty(inode); 145 146 err = ufs_add_nondir(dentry, inode); 147out: 148 return err; 149 150out_fail: 151 ufs_dec_count(inode); 152 iput(inode); 153 goto out; 154} 155 156static int ufs_link (struct dentry * old_dentry, struct inode * dir, 157 struct dentry *dentry) 158{ 159 struct inode *inode = old_dentry->d_inode; 160 161 if (S_ISDIR(inode->i_mode)) 162 return -EPERM; 163 164 if (inode->i_nlink >= UFS_LINK_MAX) 165 return -EMLINK; 166 167 inode->i_ctime = CURRENT_TIME; 168 ufs_inc_count(inode); 169 atomic_inc(&inode->i_count); 170 171 return ufs_add_nondir(dentry, inode); 172} 173 174static int ufs_mkdir(struct inode * dir, struct dentry * dentry, int mode) 175{ 176 struct inode * inode; 177 int err = -EMLINK; 178 179 if (dir->i_nlink >= UFS_LINK_MAX) 180 goto out; 181 182 ufs_inc_count(dir); 183 184 inode = ufs_new_inode(dir, S_IFDIR|mode); 185 err = PTR_ERR(inode); 186 if (IS_ERR(inode)) 187 goto out_dir; 188 189 inode->i_op = &ufs_dir_inode_operations; 190 inode->i_fop = &ufs_dir_operations; 191 192 ufs_inc_count(inode); 193 194 err = ufs_make_empty(inode, dir); 195 if (err) 196 goto out_fail; 197 198 err = ufs_add_link(dentry, inode); 199 if (err) 200 goto out_fail; 201 202 d_instantiate(dentry, inode); 203out: 204 return err; 205 206out_fail: 207 ufs_dec_count(inode); 208 ufs_dec_count(inode); 209 iput (inode); 210out_dir: 211 ufs_dec_count(dir); 212 goto out; 213} 214 215static int ufs_unlink(struct inode * dir, struct dentry *dentry) 216{ 217 struct inode * inode = dentry->d_inode; 218 struct buffer_head * bh; 219 struct ufs_dir_entry * de; 220 int err = -ENOENT; 221 222 de = ufs_find_entry (dentry, &bh); 223 if (!de) 224 goto out; 225 226 err = ufs_delete_entry (dir, de, bh); 227 if (err) 228 goto out; 229 230 inode->i_ctime = dir->i_ctime; 231 ufs_dec_count(inode); 232 err = 0; 233out: 234 return err; 235} 236 237static int ufs_rmdir (struct inode * dir, struct dentry *dentry) 238{ 239 struct inode * inode = dentry->d_inode; 240 int err= -ENOTEMPTY; 241 242 if (ufs_empty_dir (inode)) { 243 err = ufs_unlink(dir, dentry); 244 if (!err) { 245 inode->i_size = 0; 246 ufs_dec_count(inode); 247 ufs_dec_count(dir); 248 } 249 } 250 return err; 251} 252 253static int ufs_rename (struct inode * old_dir, struct dentry * old_dentry, 254 struct inode * new_dir, struct dentry * new_dentry ) 255{ 256 struct inode *old_inode = old_dentry->d_inode; 257 struct inode *new_inode = new_dentry->d_inode; 258 struct buffer_head *dir_bh = NULL; 259 struct ufs_dir_entry *dir_de = NULL; 260 struct buffer_head *old_bh; 261 struct ufs_dir_entry *old_de; 262 int err = -ENOENT; 263 264 old_de = ufs_find_entry (old_dentry, &old_bh); 265 if (!old_de) 266 goto out; 267 268 if (S_ISDIR(old_inode->i_mode)) { 269 err = -EIO; 270 dir_de = ufs_dotdot(old_inode, &dir_bh); 271 if (!dir_de) 272 goto out_old; 273 } 274 275 if (new_inode) { 276 struct buffer_head *new_bh; 277 struct ufs_dir_entry *new_de; 278 279 err = -ENOTEMPTY; 280 if (dir_de && !ufs_empty_dir (new_inode)) 281 goto out_dir; 282 err = -ENOENT; 283 new_de = ufs_find_entry (new_dentry, &new_bh); 284 if (!new_de) 285 goto out_dir; 286 ufs_inc_count(old_inode); 287 ufs_set_link(new_dir, new_de, new_bh, old_inode); 288 new_inode->i_ctime = CURRENT_TIME; 289 if (dir_de) 290 new_inode->i_nlink--; 291 ufs_dec_count(new_inode); 292 } else { 293 if (dir_de) { 294 err = -EMLINK; 295 if (new_dir->i_nlink >= UFS_LINK_MAX) 296 goto out_dir; 297 } 298 ufs_inc_count(old_inode); 299 err = ufs_add_link(new_dentry, old_inode); 300 if (err) { 301 ufs_dec_count(old_inode); 302 goto out_dir; 303 } 304 if (dir_de) 305 ufs_inc_count(new_dir); 306 } 307 308 ufs_delete_entry (old_dir, old_de, old_bh); 309 310 ufs_dec_count(old_inode); 311 312 if (dir_de) { 313 ufs_set_link(old_inode, dir_de, dir_bh, new_dir); 314 ufs_dec_count(old_dir); 315 } 316 return 0; 317 318out_dir: 319 if (dir_de) 320 brelse(dir_bh); 321out_old: 322 brelse (old_bh); 323out: 324 return err; 325} 326 327struct inode_operations ufs_dir_inode_operations = { 328 create: ufs_create, 329 lookup: ufs_lookup, 330 link: ufs_link, 331 unlink: ufs_unlink, 332 symlink: ufs_symlink, 333 mkdir: ufs_mkdir, 334 rmdir: ufs_rmdir, 335 mknod: ufs_mknod, 336 rename: ufs_rename, 337}; 338