1 /* 2 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README 3 */ 4 5 #include <linux/config.h> 6 #include <linux/string.h> 7 #include <linux/errno.h> 8 #include <linux/fs.h> 9 #include <linux/reiserfs_fs.h> 10 #include <linux/stat.h> 11 #include <linux/smp_lock.h> 12 #include <linux/buffer_head.h> 13 #include <asm/uaccess.h> 14 15 extern struct reiserfs_key MIN_KEY; 16 17 static int reiserfs_readdir(struct file *, void *, filldir_t); 18 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry, 19 int datasync); 20 21 struct file_operations reiserfs_dir_operations = { 22 .read = generic_read_dir, 23 .readdir = reiserfs_readdir, 24 .fsync = reiserfs_dir_fsync, 25 .ioctl = reiserfs_ioctl, 26 }; 27 28 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry, 29 int datasync) 30 { 31 struct inode *inode = dentry->d_inode; 32 int err; 33 reiserfs_write_lock(inode->i_sb); 34 err = reiserfs_commit_for_inode(inode); 35 reiserfs_write_unlock(inode->i_sb); 36 if (err < 0) 37 return err; 38 return 0; 39 } 40 41 #define store_ih(where,what) copy_item_head (where, what) 42 43 // 44 static int reiserfs_readdir(struct file *filp, void *dirent, filldir_t filldir) 45 { 46 struct inode *inode = filp->f_dentry->d_inode; 47 struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */ 48 INITIALIZE_PATH(path_to_entry); 49 struct buffer_head *bh; 50 int item_num, entry_num; 51 const struct reiserfs_key *rkey; 52 struct item_head *ih, tmp_ih; 53 int search_res; 54 char *local_buf; 55 loff_t next_pos; 56 char small_buf[32]; /* avoid kmalloc if we can */ 57 struct reiserfs_dir_entry de; 58 int ret = 0; 59 60 reiserfs_write_lock(inode->i_sb); 61 62 reiserfs_check_lock_depth(inode->i_sb, "readdir"); 63 64 /* form key for search the next directory entry using f_pos field of 65 file structure */ 66 make_cpu_key(&pos_key, inode, 67 (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET, TYPE_DIRENTRY, 68 3); 69 next_pos = cpu_key_k_offset(&pos_key); 70 71 /* reiserfs_warning (inode->i_sb, "reiserfs_readdir 1: f_pos = %Ld", filp->f_pos); */ 72 73 path_to_entry.reada = PATH_READA; 74 while (1) { 75 research: 76 /* search the directory item, containing entry with specified key */ 77 search_res = 78 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry, 79 &de); 80 if (search_res == IO_ERROR) { 81 // FIXME: we could just skip part of directory which could 82 // not be read 83 ret = -EIO; 84 goto out; 85 } 86 entry_num = de.de_entry_num; 87 bh = de.de_bh; 88 item_num = de.de_item_num; 89 ih = de.de_ih; 90 store_ih(&tmp_ih, ih); 91 92 /* we must have found item, that is item of this directory, */ 93 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key), 94 "vs-9000: found item %h does not match to dir we readdir %K", 95 ih, &pos_key); 96 RFALSE(item_num > B_NR_ITEMS(bh) - 1, 97 "vs-9005 item_num == %d, item amount == %d", 98 item_num, B_NR_ITEMS(bh)); 99 100 /* and entry must be not more than number of entries in the item */ 101 RFALSE(I_ENTRY_COUNT(ih) < entry_num, 102 "vs-9010: entry number is too big %d (%d)", 103 entry_num, I_ENTRY_COUNT(ih)); 104 105 if (search_res == POSITION_FOUND 106 || entry_num < I_ENTRY_COUNT(ih)) { 107 /* go through all entries in the directory item beginning from the entry, that has been found */ 108 struct reiserfs_de_head *deh = 109 B_I_DEH(bh, ih) + entry_num; 110 111 for (; entry_num < I_ENTRY_COUNT(ih); 112 entry_num++, deh++) { 113 int d_reclen; 114 char *d_name; 115 off_t d_off; 116 ino_t d_ino; 117 118 if (!de_visible(deh)) 119 /* it is hidden entry */ 120 continue; 121 d_reclen = entry_length(bh, ih, entry_num); 122 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh); 123 if (!d_name[d_reclen - 1]) 124 d_reclen = strlen(d_name); 125 126 if (d_reclen > 127 REISERFS_MAX_NAME(inode->i_sb-> 128 s_blocksize)) { 129 /* too big to send back to VFS */ 130 continue; 131 } 132 133 /* Ignore the .reiserfs_priv entry */ 134 if (reiserfs_xattrs(inode->i_sb) && 135 !old_format_only(inode->i_sb) && 136 filp->f_dentry == inode->i_sb->s_root && 137 REISERFS_SB(inode->i_sb)->priv_root && 138 REISERFS_SB(inode->i_sb)->priv_root->d_inode 139 && deh_objectid(deh) == 140 le32_to_cpu(INODE_PKEY 141 (REISERFS_SB(inode->i_sb)-> 142 priv_root->d_inode)-> 143 k_objectid)) { 144 continue; 145 } 146 147 d_off = deh_offset(deh); 148 filp->f_pos = d_off; 149 d_ino = deh_objectid(deh); 150 if (d_reclen <= 32) { 151 local_buf = small_buf; 152 } else { 153 local_buf = 154 reiserfs_kmalloc(d_reclen, GFP_NOFS, 155 inode->i_sb); 156 if (!local_buf) { 157 pathrelse(&path_to_entry); 158 ret = -ENOMEM; 159 goto out; 160 } 161 if (item_moved(&tmp_ih, &path_to_entry)) { 162 reiserfs_kfree(local_buf, 163 d_reclen, 164 inode->i_sb); 165 goto research; 166 } 167 } 168 // Note, that we copy name to user space via temporary 169 // buffer (local_buf) because filldir will block if 170 // user space buffer is swapped out. At that time 171 // entry can move to somewhere else 172 memcpy(local_buf, d_name, d_reclen); 173 if (filldir 174 (dirent, local_buf, d_reclen, d_off, d_ino, 175 DT_UNKNOWN) < 0) { 176 if (local_buf != small_buf) { 177 reiserfs_kfree(local_buf, 178 d_reclen, 179 inode->i_sb); 180 } 181 goto end; 182 } 183 if (local_buf != small_buf) { 184 reiserfs_kfree(local_buf, d_reclen, 185 inode->i_sb); 186 } 187 // next entry should be looked for with such offset 188 next_pos = deh_offset(deh) + 1; 189 190 if (item_moved(&tmp_ih, &path_to_entry)) { 191 goto research; 192 } 193 } /* for */ 194 } 195 196 if (item_num != B_NR_ITEMS(bh) - 1) 197 // end of directory has been reached 198 goto end; 199 200 /* item we went through is last item of node. Using right 201 delimiting key check is it directory end */ 202 rkey = get_rkey(&path_to_entry, inode->i_sb); 203 if (!comp_le_keys(rkey, &MIN_KEY)) { 204 /* set pos_key to key, that is the smallest and greater 205 that key of the last entry in the item */ 206 set_cpu_key_k_offset(&pos_key, next_pos); 207 continue; 208 } 209 210 if (COMP_SHORT_KEYS(rkey, &pos_key)) { 211 // end of directory has been reached 212 goto end; 213 } 214 215 /* directory continues in the right neighboring block */ 216 set_cpu_key_k_offset(&pos_key, 217 le_key_k_offset(KEY_FORMAT_3_5, rkey)); 218 219 } /* while */ 220 221 end: 222 filp->f_pos = next_pos; 223 pathrelse(&path_to_entry); 224 reiserfs_check_path(&path_to_entry); 225 out: 226 reiserfs_write_unlock(inode->i_sb); 227 return ret; 228 } 229 230 /* compose directory item containing "." and ".." entries (entries are 231 not aligned to 4 byte boundary) */ 232 /* the last four params are LE */ 233 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid, 234 __le32 par_dirid, __le32 par_objid) 235 { 236 struct reiserfs_de_head *deh; 237 238 memset(body, 0, EMPTY_DIR_SIZE_V1); 239 deh = (struct reiserfs_de_head *)body; 240 241 /* direntry header of "." */ 242 put_deh_offset(&(deh[0]), DOT_OFFSET); 243 /* these two are from make_le_item_head, and are are LE */ 244 deh[0].deh_dir_id = dirid; 245 deh[0].deh_objectid = objid; 246 deh[0].deh_state = 0; /* Endian safe if 0 */ 247 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen(".")); 248 mark_de_visible(&(deh[0])); 249 250 /* direntry header of ".." */ 251 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET); 252 /* key of ".." for the root directory */ 253 /* these two are from the inode, and are are LE */ 254 deh[1].deh_dir_id = par_dirid; 255 deh[1].deh_objectid = par_objid; 256 deh[1].deh_state = 0; /* Endian safe if 0 */ 257 put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen("..")); 258 mark_de_visible(&(deh[1])); 259 260 /* copy ".." and "." */ 261 memcpy(body + deh_location(&(deh[0])), ".", 1); 262 memcpy(body + deh_location(&(deh[1])), "..", 2); 263 } 264 265 /* compose directory item containing "." and ".." entries */ 266 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid, 267 __le32 par_dirid, __le32 par_objid) 268 { 269 struct reiserfs_de_head *deh; 270 271 memset(body, 0, EMPTY_DIR_SIZE); 272 deh = (struct reiserfs_de_head *)body; 273 274 /* direntry header of "." */ 275 put_deh_offset(&(deh[0]), DOT_OFFSET); 276 /* these two are from make_le_item_head, and are are LE */ 277 deh[0].deh_dir_id = dirid; 278 deh[0].deh_objectid = objid; 279 deh[0].deh_state = 0; /* Endian safe if 0 */ 280 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen("."))); 281 mark_de_visible(&(deh[0])); 282 283 /* direntry header of ".." */ 284 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET); 285 /* key of ".." for the root directory */ 286 /* these two are from the inode, and are are LE */ 287 deh[1].deh_dir_id = par_dirid; 288 deh[1].deh_objectid = par_objid; 289 deh[1].deh_state = 0; /* Endian safe if 0 */ 290 put_deh_location(&(deh[1]), 291 deh_location(&(deh[0])) - ROUND_UP(strlen(".."))); 292 mark_de_visible(&(deh[1])); 293 294 /* copy ".." and "." */ 295 memcpy(body + deh_location(&(deh[0])), ".", 1); 296 memcpy(body + deh_location(&(deh[1])), "..", 2); 297 } 298