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