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 <linux/slab.h> 12 #include <asm/uaccess.h> 13 14 extern const struct reiserfs_key MIN_KEY; 15 16 static int reiserfs_readdir(struct file *, void *, filldir_t); 17 static int reiserfs_dir_fsync(struct file *filp, loff_t start, loff_t end, 18 int datasync); 19 20 const struct file_operations reiserfs_dir_operations = { 21 .llseek = generic_file_llseek, 22 .read = generic_read_dir, 23 .readdir = reiserfs_readdir, 24 .fsync = reiserfs_dir_fsync, 25 .unlocked_ioctl = reiserfs_ioctl, 26 #ifdef CONFIG_COMPAT 27 .compat_ioctl = reiserfs_compat_ioctl, 28 #endif 29 }; 30 31 static int reiserfs_dir_fsync(struct file *filp, loff_t start, loff_t end, 32 int datasync) 33 { 34 struct inode *inode = filp->f_mapping->host; 35 int err; 36 37 err = filemap_write_and_wait_range(inode->i_mapping, start, end); 38 if (err) 39 return err; 40 41 mutex_lock(&inode->i_mutex); 42 reiserfs_write_lock(inode->i_sb); 43 err = reiserfs_commit_for_inode(inode); 44 reiserfs_write_unlock(inode->i_sb); 45 mutex_unlock(&inode->i_mutex); 46 if (err < 0) 47 return err; 48 return 0; 49 } 50 51 #define store_ih(where,what) copy_item_head (where, what) 52 53 static inline bool is_privroot_deh(struct dentry *dir, 54 struct reiserfs_de_head *deh) 55 { 56 struct dentry *privroot = REISERFS_SB(dir->d_sb)->priv_root; 57 return (dir == dir->d_parent && privroot->d_inode && 58 deh->deh_objectid == INODE_PKEY(privroot->d_inode)->k_objectid); 59 } 60 61 int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent, 62 filldir_t filldir, loff_t *pos) 63 { 64 struct inode *inode = dentry->d_inode; 65 struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */ 66 INITIALIZE_PATH(path_to_entry); 67 struct buffer_head *bh; 68 int item_num, entry_num; 69 const struct reiserfs_key *rkey; 70 struct item_head *ih, tmp_ih; 71 int search_res; 72 char *local_buf; 73 loff_t next_pos; 74 char small_buf[32]; /* avoid kmalloc if we can */ 75 struct reiserfs_dir_entry de; 76 int ret = 0; 77 78 reiserfs_write_lock(inode->i_sb); 79 80 reiserfs_check_lock_depth(inode->i_sb, "readdir"); 81 82 /* form key for search the next directory entry using f_pos field of 83 file structure */ 84 make_cpu_key(&pos_key, inode, *pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3); 85 next_pos = cpu_key_k_offset(&pos_key); 86 87 path_to_entry.reada = PATH_READA; 88 while (1) { 89 research: 90 /* search the directory item, containing entry with specified key */ 91 search_res = 92 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry, 93 &de); 94 if (search_res == IO_ERROR) { 95 // FIXME: we could just skip part of directory which could 96 // not be read 97 ret = -EIO; 98 goto out; 99 } 100 entry_num = de.de_entry_num; 101 bh = de.de_bh; 102 item_num = de.de_item_num; 103 ih = de.de_ih; 104 store_ih(&tmp_ih, ih); 105 106 /* we must have found item, that is item of this directory, */ 107 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key), 108 "vs-9000: found item %h does not match to dir we readdir %K", 109 ih, &pos_key); 110 RFALSE(item_num > B_NR_ITEMS(bh) - 1, 111 "vs-9005 item_num == %d, item amount == %d", 112 item_num, B_NR_ITEMS(bh)); 113 114 /* and entry must be not more than number of entries in the item */ 115 RFALSE(I_ENTRY_COUNT(ih) < entry_num, 116 "vs-9010: entry number is too big %d (%d)", 117 entry_num, I_ENTRY_COUNT(ih)); 118 119 if (search_res == POSITION_FOUND 120 || entry_num < I_ENTRY_COUNT(ih)) { 121 /* go through all entries in the directory item beginning from the entry, that has been found */ 122 struct reiserfs_de_head *deh = 123 B_I_DEH(bh, ih) + entry_num; 124 125 for (; entry_num < I_ENTRY_COUNT(ih); 126 entry_num++, deh++) { 127 int d_reclen; 128 char *d_name; 129 off_t d_off; 130 ino_t d_ino; 131 132 if (!de_visible(deh)) 133 /* it is hidden entry */ 134 continue; 135 d_reclen = entry_length(bh, ih, entry_num); 136 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh); 137 138 if (d_reclen <= 0 || 139 d_name + d_reclen > bh->b_data + bh->b_size) { 140 /* There is corrupted data in entry, 141 * We'd better stop here */ 142 pathrelse(&path_to_entry); 143 ret = -EIO; 144 goto out; 145 } 146 147 if (!d_name[d_reclen - 1]) 148 d_reclen = strlen(d_name); 149 150 if (d_reclen > 151 REISERFS_MAX_NAME(inode->i_sb-> 152 s_blocksize)) { 153 /* too big to send back to VFS */ 154 continue; 155 } 156 157 /* Ignore the .reiserfs_priv entry */ 158 if (is_privroot_deh(dentry, deh)) 159 continue; 160 161 d_off = deh_offset(deh); 162 *pos = d_off; 163 d_ino = deh_objectid(deh); 164 if (d_reclen <= 32) { 165 local_buf = small_buf; 166 } else { 167 local_buf = kmalloc(d_reclen, 168 GFP_NOFS); 169 if (!local_buf) { 170 pathrelse(&path_to_entry); 171 ret = -ENOMEM; 172 goto out; 173 } 174 if (item_moved(&tmp_ih, &path_to_entry)) { 175 kfree(local_buf); 176 goto research; 177 } 178 } 179 // Note, that we copy name to user space via temporary 180 // buffer (local_buf) because filldir will block if 181 // user space buffer is swapped out. At that time 182 // entry can move to somewhere else 183 memcpy(local_buf, d_name, d_reclen); 184 185 /* 186 * Since filldir might sleep, we can release 187 * the write lock here for other waiters 188 */ 189 reiserfs_write_unlock(inode->i_sb); 190 if (filldir 191 (dirent, local_buf, d_reclen, d_off, d_ino, 192 DT_UNKNOWN) < 0) { 193 reiserfs_write_lock(inode->i_sb); 194 if (local_buf != small_buf) { 195 kfree(local_buf); 196 } 197 goto end; 198 } 199 reiserfs_write_lock(inode->i_sb); 200 if (local_buf != small_buf) { 201 kfree(local_buf); 202 } 203 // next entry should be looked for with such offset 204 next_pos = deh_offset(deh) + 1; 205 206 if (item_moved(&tmp_ih, &path_to_entry)) { 207 goto research; 208 } 209 } /* for */ 210 } 211 212 if (item_num != B_NR_ITEMS(bh) - 1) 213 // end of directory has been reached 214 goto end; 215 216 /* item we went through is last item of node. Using right 217 delimiting key check is it directory end */ 218 rkey = get_rkey(&path_to_entry, inode->i_sb); 219 if (!comp_le_keys(rkey, &MIN_KEY)) { 220 /* set pos_key to key, that is the smallest and greater 221 that key of the last entry in the item */ 222 set_cpu_key_k_offset(&pos_key, next_pos); 223 continue; 224 } 225 226 if (COMP_SHORT_KEYS(rkey, &pos_key)) { 227 // end of directory has been reached 228 goto end; 229 } 230 231 /* directory continues in the right neighboring block */ 232 set_cpu_key_k_offset(&pos_key, 233 le_key_k_offset(KEY_FORMAT_3_5, rkey)); 234 235 } /* while */ 236 237 end: 238 *pos = next_pos; 239 pathrelse(&path_to_entry); 240 reiserfs_check_path(&path_to_entry); 241 out: 242 reiserfs_write_unlock(inode->i_sb); 243 return ret; 244 } 245 246 static int reiserfs_readdir(struct file *file, void *dirent, filldir_t filldir) 247 { 248 struct dentry *dentry = file->f_path.dentry; 249 return reiserfs_readdir_dentry(dentry, dirent, filldir, &file->f_pos); 250 } 251 252 /* compose directory item containing "." and ".." entries (entries are 253 not aligned to 4 byte boundary) */ 254 /* the last four params are LE */ 255 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid, 256 __le32 par_dirid, __le32 par_objid) 257 { 258 struct reiserfs_de_head *deh; 259 260 memset(body, 0, EMPTY_DIR_SIZE_V1); 261 deh = (struct reiserfs_de_head *)body; 262 263 /* direntry header of "." */ 264 put_deh_offset(&(deh[0]), DOT_OFFSET); 265 /* these two are from make_le_item_head, and are are LE */ 266 deh[0].deh_dir_id = dirid; 267 deh[0].deh_objectid = objid; 268 deh[0].deh_state = 0; /* Endian safe if 0 */ 269 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen(".")); 270 mark_de_visible(&(deh[0])); 271 272 /* direntry header of ".." */ 273 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET); 274 /* key of ".." for the root directory */ 275 /* these two are from the inode, and are are LE */ 276 deh[1].deh_dir_id = par_dirid; 277 deh[1].deh_objectid = par_objid; 278 deh[1].deh_state = 0; /* Endian safe if 0 */ 279 put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen("..")); 280 mark_de_visible(&(deh[1])); 281 282 /* copy ".." and "." */ 283 memcpy(body + deh_location(&(deh[0])), ".", 1); 284 memcpy(body + deh_location(&(deh[1])), "..", 2); 285 } 286 287 /* compose directory item containing "." and ".." entries */ 288 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid, 289 __le32 par_dirid, __le32 par_objid) 290 { 291 struct reiserfs_de_head *deh; 292 293 memset(body, 0, EMPTY_DIR_SIZE); 294 deh = (struct reiserfs_de_head *)body; 295 296 /* direntry header of "." */ 297 put_deh_offset(&(deh[0]), DOT_OFFSET); 298 /* these two are from make_le_item_head, and are are LE */ 299 deh[0].deh_dir_id = dirid; 300 deh[0].deh_objectid = objid; 301 deh[0].deh_state = 0; /* Endian safe if 0 */ 302 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen("."))); 303 mark_de_visible(&(deh[0])); 304 305 /* direntry header of ".." */ 306 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET); 307 /* key of ".." for the root directory */ 308 /* these two are from the inode, and are are LE */ 309 deh[1].deh_dir_id = par_dirid; 310 deh[1].deh_objectid = par_objid; 311 deh[1].deh_state = 0; /* Endian safe if 0 */ 312 put_deh_location(&(deh[1]), 313 deh_location(&(deh[0])) - ROUND_UP(strlen(".."))); 314 mark_de_visible(&(deh[1])); 315 316 /* copy ".." and "." */ 317 memcpy(body + deh_location(&(deh[0])), ".", 1); 318 memcpy(body + deh_location(&(deh[1])), "..", 2); 319 } 320