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 "reiserfs.h" 9 #include <linux/stat.h> 10 #include <linux/buffer_head.h> 11 #include <linux/slab.h> 12 #include <linux/uaccess.h> 13 14 extern const struct reiserfs_key MIN_KEY; 15 16 static int reiserfs_readdir(struct file *, struct dir_context *); 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 .iterate = 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 inode *dir, struct reiserfs_de_head *deh) 54 { 55 struct dentry *privroot = REISERFS_SB(dir->i_sb)->priv_root; 56 return (d_really_is_positive(privroot) && 57 deh->deh_objectid == INODE_PKEY(d_inode(privroot))->k_objectid); 58 } 59 60 int reiserfs_readdir_inode(struct inode *inode, struct dir_context *ctx) 61 { 62 63 /* key of current position in the directory (key of directory entry) */ 64 struct cpu_key pos_key; 65 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 int depth; 78 79 reiserfs_write_lock(inode->i_sb); 80 81 reiserfs_check_lock_depth(inode->i_sb, "readdir"); 82 83 /* 84 * form key for search the next directory entry using 85 * f_pos field of file structure 86 */ 87 make_cpu_key(&pos_key, inode, ctx->pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3); 88 next_pos = cpu_key_k_offset(&pos_key); 89 90 path_to_entry.reada = PATH_READA; 91 while (1) { 92 research: 93 /* 94 * search the directory item, containing entry with 95 * specified key 96 */ 97 search_res = 98 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry, 99 &de); 100 if (search_res == IO_ERROR) { 101 /* 102 * FIXME: we could just skip part of directory 103 * which could not be read 104 */ 105 ret = -EIO; 106 goto out; 107 } 108 entry_num = de.de_entry_num; 109 bh = de.de_bh; 110 item_num = de.de_item_num; 111 ih = de.de_ih; 112 store_ih(&tmp_ih, ih); 113 114 /* we must have found item, that is item of this directory, */ 115 RFALSE(COMP_SHORT_KEYS(&ih->ih_key, &pos_key), 116 "vs-9000: found item %h does not match to dir we readdir %K", 117 ih, &pos_key); 118 RFALSE(item_num > B_NR_ITEMS(bh) - 1, 119 "vs-9005 item_num == %d, item amount == %d", 120 item_num, B_NR_ITEMS(bh)); 121 122 /* 123 * and entry must be not more than number of entries 124 * in the item 125 */ 126 RFALSE(ih_entry_count(ih) < entry_num, 127 "vs-9010: entry number is too big %d (%d)", 128 entry_num, ih_entry_count(ih)); 129 130 /* 131 * go through all entries in the directory item beginning 132 * from the entry, that has been found 133 */ 134 if (search_res == POSITION_FOUND 135 || entry_num < ih_entry_count(ih)) { 136 struct reiserfs_de_head *deh = 137 B_I_DEH(bh, ih) + entry_num; 138 139 for (; entry_num < ih_entry_count(ih); 140 entry_num++, deh++) { 141 int d_reclen; 142 char *d_name; 143 ino_t d_ino; 144 loff_t cur_pos = deh_offset(deh); 145 146 /* it is hidden entry */ 147 if (!de_visible(deh)) 148 continue; 149 d_reclen = entry_length(bh, ih, entry_num); 150 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh); 151 152 if (d_reclen <= 0 || 153 d_name + d_reclen > bh->b_data + bh->b_size) { 154 /* 155 * There is corrupted data in entry, 156 * We'd better stop here 157 */ 158 pathrelse(&path_to_entry); 159 ret = -EIO; 160 goto out; 161 } 162 163 if (!d_name[d_reclen - 1]) 164 d_reclen = strlen(d_name); 165 166 /* too big to send back to VFS */ 167 if (d_reclen > 168 REISERFS_MAX_NAME(inode->i_sb-> 169 s_blocksize)) { 170 continue; 171 } 172 173 /* Ignore the .reiserfs_priv entry */ 174 if (is_privroot_deh(inode, deh)) 175 continue; 176 177 ctx->pos = deh_offset(deh); 178 d_ino = deh_objectid(deh); 179 if (d_reclen <= 32) { 180 local_buf = small_buf; 181 } else { 182 local_buf = kmalloc(d_reclen, 183 GFP_NOFS); 184 if (!local_buf) { 185 pathrelse(&path_to_entry); 186 ret = -ENOMEM; 187 goto out; 188 } 189 if (item_moved(&tmp_ih, &path_to_entry)) { 190 kfree(local_buf); 191 goto research; 192 } 193 } 194 195 /* 196 * Note, that we copy name to user space via 197 * temporary buffer (local_buf) because 198 * filldir will block if user space buffer is 199 * swapped out. At that time entry can move to 200 * somewhere else 201 */ 202 memcpy(local_buf, d_name, d_reclen); 203 204 /* 205 * Since filldir might sleep, we can release 206 * the write lock here for other waiters 207 */ 208 depth = reiserfs_write_unlock_nested(inode->i_sb); 209 if (!dir_emit 210 (ctx, local_buf, d_reclen, d_ino, 211 DT_UNKNOWN)) { 212 reiserfs_write_lock_nested(inode->i_sb, depth); 213 if (local_buf != small_buf) { 214 kfree(local_buf); 215 } 216 goto end; 217 } 218 reiserfs_write_lock_nested(inode->i_sb, depth); 219 if (local_buf != small_buf) { 220 kfree(local_buf); 221 } 222 223 /* deh_offset(deh) may be invalid now. */ 224 next_pos = cur_pos + 1; 225 226 if (item_moved(&tmp_ih, &path_to_entry)) { 227 set_cpu_key_k_offset(&pos_key, 228 next_pos); 229 goto research; 230 } 231 } /* for */ 232 } 233 234 /* end of directory has been reached */ 235 if (item_num != B_NR_ITEMS(bh) - 1) 236 goto end; 237 238 /* 239 * item we went through is last item of node. Using right 240 * delimiting key check is it directory end 241 */ 242 rkey = get_rkey(&path_to_entry, inode->i_sb); 243 if (!comp_le_keys(rkey, &MIN_KEY)) { 244 /* 245 * set pos_key to key, that is the smallest and greater 246 * that key of the last entry in the item 247 */ 248 set_cpu_key_k_offset(&pos_key, next_pos); 249 continue; 250 } 251 252 /* end of directory has been reached */ 253 if (COMP_SHORT_KEYS(rkey, &pos_key)) { 254 goto end; 255 } 256 257 /* directory continues in the right neighboring block */ 258 set_cpu_key_k_offset(&pos_key, 259 le_key_k_offset(KEY_FORMAT_3_5, rkey)); 260 261 } /* while */ 262 263 end: 264 ctx->pos = next_pos; 265 pathrelse(&path_to_entry); 266 reiserfs_check_path(&path_to_entry); 267 out: 268 reiserfs_write_unlock(inode->i_sb); 269 return ret; 270 } 271 272 static int reiserfs_readdir(struct file *file, struct dir_context *ctx) 273 { 274 return reiserfs_readdir_inode(file_inode(file), ctx); 275 } 276 277 /* 278 * compose directory item containing "." and ".." entries (entries are 279 * not aligned to 4 byte boundary) 280 */ 281 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid, 282 __le32 par_dirid, __le32 par_objid) 283 { 284 struct reiserfs_de_head *dot, *dotdot; 285 286 memset(body, 0, EMPTY_DIR_SIZE_V1); 287 dot = (struct reiserfs_de_head *)body; 288 dotdot = dot + 1; 289 290 /* direntry header of "." */ 291 put_deh_offset(dot, DOT_OFFSET); 292 /* these two are from make_le_item_head, and are are LE */ 293 dot->deh_dir_id = dirid; 294 dot->deh_objectid = objid; 295 dot->deh_state = 0; /* Endian safe if 0 */ 296 put_deh_location(dot, EMPTY_DIR_SIZE_V1 - strlen(".")); 297 mark_de_visible(dot); 298 299 /* direntry header of ".." */ 300 put_deh_offset(dotdot, DOT_DOT_OFFSET); 301 /* key of ".." for the root directory */ 302 /* these two are from the inode, and are are LE */ 303 dotdot->deh_dir_id = par_dirid; 304 dotdot->deh_objectid = par_objid; 305 dotdot->deh_state = 0; /* Endian safe if 0 */ 306 put_deh_location(dotdot, deh_location(dot) - strlen("..")); 307 mark_de_visible(dotdot); 308 309 /* copy ".." and "." */ 310 memcpy(body + deh_location(dot), ".", 1); 311 memcpy(body + deh_location(dotdot), "..", 2); 312 } 313 314 /* compose directory item containing "." and ".." entries */ 315 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid, 316 __le32 par_dirid, __le32 par_objid) 317 { 318 struct reiserfs_de_head *dot, *dotdot; 319 320 memset(body, 0, EMPTY_DIR_SIZE); 321 dot = (struct reiserfs_de_head *)body; 322 dotdot = dot + 1; 323 324 /* direntry header of "." */ 325 put_deh_offset(dot, DOT_OFFSET); 326 /* these two are from make_le_item_head, and are are LE */ 327 dot->deh_dir_id = dirid; 328 dot->deh_objectid = objid; 329 dot->deh_state = 0; /* Endian safe if 0 */ 330 put_deh_location(dot, EMPTY_DIR_SIZE - ROUND_UP(strlen("."))); 331 mark_de_visible(dot); 332 333 /* direntry header of ".." */ 334 put_deh_offset(dotdot, DOT_DOT_OFFSET); 335 /* key of ".." for the root directory */ 336 /* these two are from the inode, and are are LE */ 337 dotdot->deh_dir_id = par_dirid; 338 dotdot->deh_objectid = par_objid; 339 dotdot->deh_state = 0; /* Endian safe if 0 */ 340 put_deh_location(dotdot, deh_location(dot) - ROUND_UP(strlen(".."))); 341 mark_de_visible(dotdot); 342 343 /* copy ".." and "." */ 344 memcpy(body + deh_location(dot), ".", 1); 345 memcpy(body + deh_location(dotdot), "..", 2); 346 } 347