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