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 int depth; 75 76 reiserfs_write_lock(inode->i_sb); 77 78 reiserfs_check_lock_depth(inode->i_sb, "readdir"); 79 80 /* form key for search the next directory entry using f_pos field of 81 file structure */ 82 make_cpu_key(&pos_key, inode, ctx->pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3); 83 next_pos = cpu_key_k_offset(&pos_key); 84 85 path_to_entry.reada = PATH_READA; 86 while (1) { 87 research: 88 /* search the directory item, containing entry with specified key */ 89 search_res = 90 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry, 91 &de); 92 if (search_res == IO_ERROR) { 93 // FIXME: we could just skip part of directory which could 94 // not be read 95 ret = -EIO; 96 goto out; 97 } 98 entry_num = de.de_entry_num; 99 bh = de.de_bh; 100 item_num = de.de_item_num; 101 ih = de.de_ih; 102 store_ih(&tmp_ih, ih); 103 104 /* we must have found item, that is item of this directory, */ 105 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key), 106 "vs-9000: found item %h does not match to dir we readdir %K", 107 ih, &pos_key); 108 RFALSE(item_num > B_NR_ITEMS(bh) - 1, 109 "vs-9005 item_num == %d, item amount == %d", 110 item_num, B_NR_ITEMS(bh)); 111 112 /* and entry must be not more than number of entries in the item */ 113 RFALSE(I_ENTRY_COUNT(ih) < entry_num, 114 "vs-9010: entry number is too big %d (%d)", 115 entry_num, I_ENTRY_COUNT(ih)); 116 117 if (search_res == POSITION_FOUND 118 || entry_num < I_ENTRY_COUNT(ih)) { 119 /* go through all entries in the directory item beginning from the entry, that has been found */ 120 struct reiserfs_de_head *deh = 121 B_I_DEH(bh, ih) + entry_num; 122 123 for (; entry_num < I_ENTRY_COUNT(ih); 124 entry_num++, deh++) { 125 int d_reclen; 126 char *d_name; 127 ino_t d_ino; 128 129 if (!de_visible(deh)) 130 /* it is hidden entry */ 131 continue; 132 d_reclen = entry_length(bh, ih, entry_num); 133 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh); 134 135 if (d_reclen <= 0 || 136 d_name + d_reclen > bh->b_data + bh->b_size) { 137 /* There is corrupted data in entry, 138 * We'd better stop here */ 139 pathrelse(&path_to_entry); 140 ret = -EIO; 141 goto out; 142 } 143 144 if (!d_name[d_reclen - 1]) 145 d_reclen = strlen(d_name); 146 147 if (d_reclen > 148 REISERFS_MAX_NAME(inode->i_sb-> 149 s_blocksize)) { 150 /* too big to send back to VFS */ 151 continue; 152 } 153 154 /* Ignore the .reiserfs_priv entry */ 155 if (is_privroot_deh(inode, deh)) 156 continue; 157 158 ctx->pos = deh_offset(deh); 159 d_ino = deh_objectid(deh); 160 if (d_reclen <= 32) { 161 local_buf = small_buf; 162 } else { 163 local_buf = kmalloc(d_reclen, 164 GFP_NOFS); 165 if (!local_buf) { 166 pathrelse(&path_to_entry); 167 ret = -ENOMEM; 168 goto out; 169 } 170 if (item_moved(&tmp_ih, &path_to_entry)) { 171 kfree(local_buf); 172 goto research; 173 } 174 } 175 // Note, that we copy name to user space via temporary 176 // buffer (local_buf) because filldir will block if 177 // user space buffer is swapped out. At that time 178 // entry can move to somewhere else 179 memcpy(local_buf, d_name, d_reclen); 180 181 /* 182 * Since filldir might sleep, we can release 183 * the write lock here for other waiters 184 */ 185 depth = reiserfs_write_unlock_nested(inode->i_sb); 186 if (!dir_emit 187 (ctx, local_buf, d_reclen, d_ino, 188 DT_UNKNOWN)) { 189 reiserfs_write_lock_nested(inode->i_sb, depth); 190 if (local_buf != small_buf) { 191 kfree(local_buf); 192 } 193 goto end; 194 } 195 reiserfs_write_lock_nested(inode->i_sb, depth); 196 if (local_buf != small_buf) { 197 kfree(local_buf); 198 } 199 // next entry should be looked for with such offset 200 next_pos = deh_offset(deh) + 1; 201 202 if (item_moved(&tmp_ih, &path_to_entry)) { 203 set_cpu_key_k_offset(&pos_key, 204 next_pos); 205 goto research; 206 } 207 } /* for */ 208 } 209 210 if (item_num != B_NR_ITEMS(bh) - 1) 211 // end of directory has been reached 212 goto end; 213 214 /* item we went through is last item of node. Using right 215 delimiting key check is it directory end */ 216 rkey = get_rkey(&path_to_entry, inode->i_sb); 217 if (!comp_le_keys(rkey, &MIN_KEY)) { 218 /* set pos_key to key, that is the smallest and greater 219 that key of the last entry in the item */ 220 set_cpu_key_k_offset(&pos_key, next_pos); 221 continue; 222 } 223 224 if (COMP_SHORT_KEYS(rkey, &pos_key)) { 225 // end of directory has been reached 226 goto end; 227 } 228 229 /* directory continues in the right neighboring block */ 230 set_cpu_key_k_offset(&pos_key, 231 le_key_k_offset(KEY_FORMAT_3_5, rkey)); 232 233 } /* while */ 234 235 end: 236 ctx->pos = next_pos; 237 pathrelse(&path_to_entry); 238 reiserfs_check_path(&path_to_entry); 239 out: 240 reiserfs_write_unlock(inode->i_sb); 241 return ret; 242 } 243 244 static int reiserfs_readdir(struct file *file, struct dir_context *ctx) 245 { 246 return reiserfs_readdir_inode(file_inode(file), ctx); 247 } 248 249 /* compose directory item containing "." and ".." entries (entries are 250 not aligned to 4 byte boundary) */ 251 /* the last four params are LE */ 252 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid, 253 __le32 par_dirid, __le32 par_objid) 254 { 255 struct reiserfs_de_head *deh; 256 257 memset(body, 0, EMPTY_DIR_SIZE_V1); 258 deh = (struct reiserfs_de_head *)body; 259 260 /* direntry header of "." */ 261 put_deh_offset(&(deh[0]), DOT_OFFSET); 262 /* these two are from make_le_item_head, and are are LE */ 263 deh[0].deh_dir_id = dirid; 264 deh[0].deh_objectid = objid; 265 deh[0].deh_state = 0; /* Endian safe if 0 */ 266 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen(".")); 267 mark_de_visible(&(deh[0])); 268 269 /* direntry header of ".." */ 270 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET); 271 /* key of ".." for the root directory */ 272 /* these two are from the inode, and are are LE */ 273 deh[1].deh_dir_id = par_dirid; 274 deh[1].deh_objectid = par_objid; 275 deh[1].deh_state = 0; /* Endian safe if 0 */ 276 put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen("..")); 277 mark_de_visible(&(deh[1])); 278 279 /* copy ".." and "." */ 280 memcpy(body + deh_location(&(deh[0])), ".", 1); 281 memcpy(body + deh_location(&(deh[1])), "..", 2); 282 } 283 284 /* compose directory item containing "." and ".." entries */ 285 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid, 286 __le32 par_dirid, __le32 par_objid) 287 { 288 struct reiserfs_de_head *deh; 289 290 memset(body, 0, EMPTY_DIR_SIZE); 291 deh = (struct reiserfs_de_head *)body; 292 293 /* direntry header of "." */ 294 put_deh_offset(&(deh[0]), DOT_OFFSET); 295 /* these two are from make_le_item_head, and are are LE */ 296 deh[0].deh_dir_id = dirid; 297 deh[0].deh_objectid = objid; 298 deh[0].deh_state = 0; /* Endian safe if 0 */ 299 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen("."))); 300 mark_de_visible(&(deh[0])); 301 302 /* direntry header of ".." */ 303 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET); 304 /* key of ".." for the root directory */ 305 /* these two are from the inode, and are are LE */ 306 deh[1].deh_dir_id = par_dirid; 307 deh[1].deh_objectid = par_objid; 308 deh[1].deh_state = 0; /* Endian safe if 0 */ 309 put_deh_location(&(deh[1]), 310 deh_location(&(deh[0])) - ROUND_UP(strlen(".."))); 311 mark_de_visible(&(deh[1])); 312 313 /* copy ".." and "." */ 314 memcpy(body + deh_location(&(deh[0])), ".", 1); 315 memcpy(body + deh_location(&(deh[1])), "..", 2); 316 } 317