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