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