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 // 45 static int reiserfs_readdir(struct file *filp, void *dirent, filldir_t filldir) 46 { 47 struct inode *inode = filp->f_path.dentry->d_inode; 48 struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */ 49 INITIALIZE_PATH(path_to_entry); 50 struct buffer_head *bh; 51 int item_num, entry_num; 52 const struct reiserfs_key *rkey; 53 struct item_head *ih, tmp_ih; 54 int search_res; 55 char *local_buf; 56 loff_t next_pos; 57 char small_buf[32]; /* avoid kmalloc if we can */ 58 struct reiserfs_dir_entry de; 59 int ret = 0; 60 61 reiserfs_write_lock(inode->i_sb); 62 63 reiserfs_check_lock_depth(inode->i_sb, "readdir"); 64 65 /* form key for search the next directory entry using f_pos field of 66 file structure */ 67 make_cpu_key(&pos_key, inode, 68 (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET, TYPE_DIRENTRY, 69 3); 70 next_pos = cpu_key_k_offset(&pos_key); 71 72 /* reiserfs_warning (inode->i_sb, "reiserfs_readdir 1: f_pos = %Ld", filp->f_pos); */ 73 74 path_to_entry.reada = PATH_READA; 75 while (1) { 76 research: 77 /* search the directory item, containing entry with specified key */ 78 search_res = 79 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry, 80 &de); 81 if (search_res == IO_ERROR) { 82 // FIXME: we could just skip part of directory which could 83 // not be read 84 ret = -EIO; 85 goto out; 86 } 87 entry_num = de.de_entry_num; 88 bh = de.de_bh; 89 item_num = de.de_item_num; 90 ih = de.de_ih; 91 store_ih(&tmp_ih, ih); 92 93 /* we must have found item, that is item of this directory, */ 94 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key), 95 "vs-9000: found item %h does not match to dir we readdir %K", 96 ih, &pos_key); 97 RFALSE(item_num > B_NR_ITEMS(bh) - 1, 98 "vs-9005 item_num == %d, item amount == %d", 99 item_num, B_NR_ITEMS(bh)); 100 101 /* and entry must be not more than number of entries in the item */ 102 RFALSE(I_ENTRY_COUNT(ih) < entry_num, 103 "vs-9010: entry number is too big %d (%d)", 104 entry_num, I_ENTRY_COUNT(ih)); 105 106 if (search_res == POSITION_FOUND 107 || entry_num < I_ENTRY_COUNT(ih)) { 108 /* go through all entries in the directory item beginning from the entry, that has been found */ 109 struct reiserfs_de_head *deh = 110 B_I_DEH(bh, ih) + entry_num; 111 112 for (; entry_num < I_ENTRY_COUNT(ih); 113 entry_num++, deh++) { 114 int d_reclen; 115 char *d_name; 116 off_t d_off; 117 ino_t d_ino; 118 119 if (!de_visible(deh)) 120 /* it is hidden entry */ 121 continue; 122 d_reclen = entry_length(bh, ih, entry_num); 123 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh); 124 125 if (d_reclen <= 0 || 126 d_name + d_reclen > bh->b_data + bh->b_size) { 127 /* There is corrupted data in entry, 128 * We'd better stop here */ 129 pathrelse(&path_to_entry); 130 ret = -EIO; 131 goto out; 132 } 133 134 if (!d_name[d_reclen - 1]) 135 d_reclen = strlen(d_name); 136 137 if (d_reclen > 138 REISERFS_MAX_NAME(inode->i_sb-> 139 s_blocksize)) { 140 /* too big to send back to VFS */ 141 continue; 142 } 143 144 /* Ignore the .reiserfs_priv entry */ 145 if (reiserfs_xattrs(inode->i_sb) && 146 !old_format_only(inode->i_sb) && 147 filp->f_path.dentry == inode->i_sb->s_root && 148 REISERFS_SB(inode->i_sb)->priv_root && 149 REISERFS_SB(inode->i_sb)->priv_root->d_inode 150 && deh_objectid(deh) == 151 le32_to_cpu(INODE_PKEY 152 (REISERFS_SB(inode->i_sb)-> 153 priv_root->d_inode)-> 154 k_objectid)) { 155 continue; 156 } 157 158 d_off = deh_offset(deh); 159 filp->f_pos = d_off; 160 d_ino = deh_objectid(deh); 161 if (d_reclen <= 32) { 162 local_buf = small_buf; 163 } else { 164 local_buf = kmalloc(d_reclen, 165 GFP_NOFS); 166 if (!local_buf) { 167 pathrelse(&path_to_entry); 168 ret = -ENOMEM; 169 goto out; 170 } 171 if (item_moved(&tmp_ih, &path_to_entry)) { 172 kfree(local_buf); 173 goto research; 174 } 175 } 176 // Note, that we copy name to user space via temporary 177 // buffer (local_buf) because filldir will block if 178 // user space buffer is swapped out. At that time 179 // entry can move to somewhere else 180 memcpy(local_buf, d_name, d_reclen); 181 if (filldir 182 (dirent, local_buf, d_reclen, d_off, d_ino, 183 DT_UNKNOWN) < 0) { 184 if (local_buf != small_buf) { 185 kfree(local_buf); 186 } 187 goto end; 188 } 189 if (local_buf != small_buf) { 190 kfree(local_buf); 191 } 192 // next entry should be looked for with such offset 193 next_pos = deh_offset(deh) + 1; 194 195 if (item_moved(&tmp_ih, &path_to_entry)) { 196 goto research; 197 } 198 } /* for */ 199 } 200 201 if (item_num != B_NR_ITEMS(bh) - 1) 202 // end of directory has been reached 203 goto end; 204 205 /* item we went through is last item of node. Using right 206 delimiting key check is it directory end */ 207 rkey = get_rkey(&path_to_entry, inode->i_sb); 208 if (!comp_le_keys(rkey, &MIN_KEY)) { 209 /* set pos_key to key, that is the smallest and greater 210 that key of the last entry in the item */ 211 set_cpu_key_k_offset(&pos_key, next_pos); 212 continue; 213 } 214 215 if (COMP_SHORT_KEYS(rkey, &pos_key)) { 216 // end of directory has been reached 217 goto end; 218 } 219 220 /* directory continues in the right neighboring block */ 221 set_cpu_key_k_offset(&pos_key, 222 le_key_k_offset(KEY_FORMAT_3_5, rkey)); 223 224 } /* while */ 225 226 end: 227 filp->f_pos = next_pos; 228 pathrelse(&path_to_entry); 229 reiserfs_check_path(&path_to_entry); 230 out: 231 reiserfs_write_unlock(inode->i_sb); 232 return ret; 233 } 234 235 /* compose directory item containing "." and ".." entries (entries are 236 not aligned to 4 byte boundary) */ 237 /* the last four params are LE */ 238 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid, 239 __le32 par_dirid, __le32 par_objid) 240 { 241 struct reiserfs_de_head *deh; 242 243 memset(body, 0, EMPTY_DIR_SIZE_V1); 244 deh = (struct reiserfs_de_head *)body; 245 246 /* direntry header of "." */ 247 put_deh_offset(&(deh[0]), DOT_OFFSET); 248 /* these two are from make_le_item_head, and are are LE */ 249 deh[0].deh_dir_id = dirid; 250 deh[0].deh_objectid = objid; 251 deh[0].deh_state = 0; /* Endian safe if 0 */ 252 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen(".")); 253 mark_de_visible(&(deh[0])); 254 255 /* direntry header of ".." */ 256 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET); 257 /* key of ".." for the root directory */ 258 /* these two are from the inode, and are are LE */ 259 deh[1].deh_dir_id = par_dirid; 260 deh[1].deh_objectid = par_objid; 261 deh[1].deh_state = 0; /* Endian safe if 0 */ 262 put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen("..")); 263 mark_de_visible(&(deh[1])); 264 265 /* copy ".." and "." */ 266 memcpy(body + deh_location(&(deh[0])), ".", 1); 267 memcpy(body + deh_location(&(deh[1])), "..", 2); 268 } 269 270 /* compose directory item containing "." and ".." entries */ 271 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid, 272 __le32 par_dirid, __le32 par_objid) 273 { 274 struct reiserfs_de_head *deh; 275 276 memset(body, 0, EMPTY_DIR_SIZE); 277 deh = (struct reiserfs_de_head *)body; 278 279 /* direntry header of "." */ 280 put_deh_offset(&(deh[0]), DOT_OFFSET); 281 /* these two are from make_le_item_head, and are are LE */ 282 deh[0].deh_dir_id = dirid; 283 deh[0].deh_objectid = objid; 284 deh[0].deh_state = 0; /* Endian safe if 0 */ 285 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen("."))); 286 mark_de_visible(&(deh[0])); 287 288 /* direntry header of ".." */ 289 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET); 290 /* key of ".." for the root directory */ 291 /* these two are from the inode, and are are LE */ 292 deh[1].deh_dir_id = par_dirid; 293 deh[1].deh_objectid = par_objid; 294 deh[1].deh_state = 0; /* Endian safe if 0 */ 295 put_deh_location(&(deh[1]), 296 deh_location(&(deh[0])) - ROUND_UP(strlen(".."))); 297 mark_de_visible(&(deh[1])); 298 299 /* copy ".." and "." */ 300 memcpy(body + deh_location(&(deh[0])), ".", 1); 301 memcpy(body + deh_location(&(deh[1])), "..", 2); 302 } 303