1 /* 2 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README 3 */ 4 5 #include <linux/string.h> 6 #include <linux/errno.h> 7 #include <linux/fs.h> 8 #include <linux/reiserfs_fs.h> 9 #include <linux/stat.h> 10 #include <linux/buffer_head.h> 11 #include <asm/uaccess.h> 12 13 extern const struct reiserfs_key MIN_KEY; 14 15 static int reiserfs_readdir(struct file *, void *, filldir_t); 16 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry, 17 int datasync); 18 19 const struct file_operations reiserfs_dir_operations = { 20 .read = generic_read_dir, 21 .readdir = reiserfs_readdir, 22 .fsync = reiserfs_dir_fsync, 23 .ioctl = reiserfs_ioctl, 24 #ifdef CONFIG_COMPAT 25 .compat_ioctl = reiserfs_compat_ioctl, 26 #endif 27 }; 28 29 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry, 30 int datasync) 31 { 32 struct inode *inode = dentry->d_inode; 33 int err; 34 reiserfs_write_lock(inode->i_sb); 35 err = reiserfs_commit_for_inode(inode); 36 reiserfs_write_unlock(inode->i_sb); 37 if (err < 0) 38 return err; 39 return 0; 40 } 41 42 #define store_ih(where,what) copy_item_head (where, what) 43 44 static inline bool is_privroot_deh(struct dentry *dir, 45 struct reiserfs_de_head *deh) 46 { 47 int ret = 0; 48 #ifdef CONFIG_REISERFS_FS_XATTR 49 struct dentry *privroot = REISERFS_SB(dir->d_sb)->priv_root; 50 ret = (dir == dir->d_parent && privroot->d_inode && 51 deh->deh_objectid == INODE_PKEY(privroot->d_inode)->k_objectid); 52 #endif 53 return ret; 54 } 55 56 int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent, 57 filldir_t filldir, loff_t *pos) 58 { 59 struct inode *inode = dentry->d_inode; 60 struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */ 61 INITIALIZE_PATH(path_to_entry); 62 struct buffer_head *bh; 63 int item_num, entry_num; 64 const struct reiserfs_key *rkey; 65 struct item_head *ih, tmp_ih; 66 int search_res; 67 char *local_buf; 68 loff_t next_pos; 69 char small_buf[32]; /* avoid kmalloc if we can */ 70 struct reiserfs_dir_entry de; 71 int ret = 0; 72 73 reiserfs_write_lock(inode->i_sb); 74 75 reiserfs_check_lock_depth(inode->i_sb, "readdir"); 76 77 /* form key for search the next directory entry using f_pos field of 78 file structure */ 79 make_cpu_key(&pos_key, inode, *pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3); 80 next_pos = cpu_key_k_offset(&pos_key); 81 82 path_to_entry.reada = PATH_READA; 83 while (1) { 84 research: 85 /* search the directory item, containing entry with specified key */ 86 search_res = 87 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry, 88 &de); 89 if (search_res == IO_ERROR) { 90 // FIXME: we could just skip part of directory which could 91 // not be read 92 ret = -EIO; 93 goto out; 94 } 95 entry_num = de.de_entry_num; 96 bh = de.de_bh; 97 item_num = de.de_item_num; 98 ih = de.de_ih; 99 store_ih(&tmp_ih, ih); 100 101 /* we must have found item, that is item of this directory, */ 102 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key), 103 "vs-9000: found item %h does not match to dir we readdir %K", 104 ih, &pos_key); 105 RFALSE(item_num > B_NR_ITEMS(bh) - 1, 106 "vs-9005 item_num == %d, item amount == %d", 107 item_num, B_NR_ITEMS(bh)); 108 109 /* and entry must be not more than number of entries in the item */ 110 RFALSE(I_ENTRY_COUNT(ih) < entry_num, 111 "vs-9010: entry number is too big %d (%d)", 112 entry_num, I_ENTRY_COUNT(ih)); 113 114 if (search_res == POSITION_FOUND 115 || entry_num < I_ENTRY_COUNT(ih)) { 116 /* go through all entries in the directory item beginning from the entry, that has been found */ 117 struct reiserfs_de_head *deh = 118 B_I_DEH(bh, ih) + entry_num; 119 120 for (; entry_num < I_ENTRY_COUNT(ih); 121 entry_num++, deh++) { 122 int d_reclen; 123 char *d_name; 124 off_t d_off; 125 ino_t d_ino; 126 127 if (!de_visible(deh)) 128 /* it is hidden entry */ 129 continue; 130 d_reclen = entry_length(bh, ih, entry_num); 131 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh); 132 133 if (d_reclen <= 0 || 134 d_name + d_reclen > bh->b_data + bh->b_size) { 135 /* There is corrupted data in entry, 136 * We'd better stop here */ 137 pathrelse(&path_to_entry); 138 ret = -EIO; 139 goto out; 140 } 141 142 if (!d_name[d_reclen - 1]) 143 d_reclen = strlen(d_name); 144 145 if (d_reclen > 146 REISERFS_MAX_NAME(inode->i_sb-> 147 s_blocksize)) { 148 /* too big to send back to VFS */ 149 continue; 150 } 151 152 /* Ignore the .reiserfs_priv entry */ 153 if (is_privroot_deh(dentry, deh)) 154 continue; 155 156 d_off = deh_offset(deh); 157 *pos = d_off; 158 d_ino = deh_objectid(deh); 159 if (d_reclen <= 32) { 160 local_buf = small_buf; 161 } else { 162 local_buf = kmalloc(d_reclen, 163 GFP_NOFS); 164 if (!local_buf) { 165 pathrelse(&path_to_entry); 166 ret = -ENOMEM; 167 goto out; 168 } 169 if (item_moved(&tmp_ih, &path_to_entry)) { 170 kfree(local_buf); 171 goto research; 172 } 173 } 174 // Note, that we copy name to user space via temporary 175 // buffer (local_buf) because filldir will block if 176 // user space buffer is swapped out. At that time 177 // entry can move to somewhere else 178 memcpy(local_buf, d_name, d_reclen); 179 if (filldir 180 (dirent, local_buf, d_reclen, d_off, d_ino, 181 DT_UNKNOWN) < 0) { 182 if (local_buf != small_buf) { 183 kfree(local_buf); 184 } 185 goto end; 186 } 187 if (local_buf != small_buf) { 188 kfree(local_buf); 189 } 190 // next entry should be looked for with such offset 191 next_pos = deh_offset(deh) + 1; 192 193 if (item_moved(&tmp_ih, &path_to_entry)) { 194 goto research; 195 } 196 } /* for */ 197 } 198 199 if (item_num != B_NR_ITEMS(bh) - 1) 200 // end of directory has been reached 201 goto end; 202 203 /* item we went through is last item of node. Using right 204 delimiting key check is it directory end */ 205 rkey = get_rkey(&path_to_entry, inode->i_sb); 206 if (!comp_le_keys(rkey, &MIN_KEY)) { 207 /* set pos_key to key, that is the smallest and greater 208 that key of the last entry in the item */ 209 set_cpu_key_k_offset(&pos_key, next_pos); 210 continue; 211 } 212 213 if (COMP_SHORT_KEYS(rkey, &pos_key)) { 214 // end of directory has been reached 215 goto end; 216 } 217 218 /* directory continues in the right neighboring block */ 219 set_cpu_key_k_offset(&pos_key, 220 le_key_k_offset(KEY_FORMAT_3_5, rkey)); 221 222 } /* while */ 223 224 end: 225 *pos = next_pos; 226 pathrelse(&path_to_entry); 227 reiserfs_check_path(&path_to_entry); 228 out: 229 reiserfs_write_unlock(inode->i_sb); 230 return ret; 231 } 232 233 static int reiserfs_readdir(struct file *file, void *dirent, filldir_t filldir) 234 { 235 struct dentry *dentry = file->f_path.dentry; 236 return reiserfs_readdir_dentry(dentry, dirent, filldir, &file->f_pos); 237 } 238 239 /* compose directory item containing "." and ".." entries (entries are 240 not aligned to 4 byte boundary) */ 241 /* the last four params are LE */ 242 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid, 243 __le32 par_dirid, __le32 par_objid) 244 { 245 struct reiserfs_de_head *deh; 246 247 memset(body, 0, EMPTY_DIR_SIZE_V1); 248 deh = (struct reiserfs_de_head *)body; 249 250 /* direntry header of "." */ 251 put_deh_offset(&(deh[0]), DOT_OFFSET); 252 /* these two are from make_le_item_head, and are are LE */ 253 deh[0].deh_dir_id = dirid; 254 deh[0].deh_objectid = objid; 255 deh[0].deh_state = 0; /* Endian safe if 0 */ 256 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen(".")); 257 mark_de_visible(&(deh[0])); 258 259 /* direntry header of ".." */ 260 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET); 261 /* key of ".." for the root directory */ 262 /* these two are from the inode, and are are LE */ 263 deh[1].deh_dir_id = par_dirid; 264 deh[1].deh_objectid = par_objid; 265 deh[1].deh_state = 0; /* Endian safe if 0 */ 266 put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen("..")); 267 mark_de_visible(&(deh[1])); 268 269 /* copy ".." and "." */ 270 memcpy(body + deh_location(&(deh[0])), ".", 1); 271 memcpy(body + deh_location(&(deh[1])), "..", 2); 272 } 273 274 /* compose directory item containing "." and ".." entries */ 275 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid, 276 __le32 par_dirid, __le32 par_objid) 277 { 278 struct reiserfs_de_head *deh; 279 280 memset(body, 0, EMPTY_DIR_SIZE); 281 deh = (struct reiserfs_de_head *)body; 282 283 /* direntry header of "." */ 284 put_deh_offset(&(deh[0]), DOT_OFFSET); 285 /* these two are from make_le_item_head, and are are LE */ 286 deh[0].deh_dir_id = dirid; 287 deh[0].deh_objectid = objid; 288 deh[0].deh_state = 0; /* Endian safe if 0 */ 289 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen("."))); 290 mark_de_visible(&(deh[0])); 291 292 /* direntry header of ".." */ 293 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET); 294 /* key of ".." for the root directory */ 295 /* these two are from the inode, and are are LE */ 296 deh[1].deh_dir_id = par_dirid; 297 deh[1].deh_objectid = par_objid; 298 deh[1].deh_state = 0; /* Endian safe if 0 */ 299 put_deh_location(&(deh[1]), 300 deh_location(&(deh[0])) - ROUND_UP(strlen(".."))); 301 mark_de_visible(&(deh[1])); 302 303 /* copy ".." and "." */ 304 memcpy(body + deh_location(&(deh[0])), ".", 1); 305 memcpy(body + deh_location(&(deh[1])), "..", 2); 306 } 307