1ac27a0ecSDave Kleikamp /* 2617ba13bSMingming Cao * linux/fs/ext4/dir.c 3ac27a0ecSDave Kleikamp * 4ac27a0ecSDave Kleikamp * Copyright (C) 1992, 1993, 1994, 1995 5ac27a0ecSDave Kleikamp * Remy Card (card@masi.ibp.fr) 6ac27a0ecSDave Kleikamp * Laboratoire MASI - Institut Blaise Pascal 7ac27a0ecSDave Kleikamp * Universite Pierre et Marie Curie (Paris VI) 8ac27a0ecSDave Kleikamp * 9ac27a0ecSDave Kleikamp * from 10ac27a0ecSDave Kleikamp * 11ac27a0ecSDave Kleikamp * linux/fs/minix/dir.c 12ac27a0ecSDave Kleikamp * 13ac27a0ecSDave Kleikamp * Copyright (C) 1991, 1992 Linus Torvalds 14ac27a0ecSDave Kleikamp * 15617ba13bSMingming Cao * ext4 directory handling functions 16ac27a0ecSDave Kleikamp * 17ac27a0ecSDave Kleikamp * Big-endian to little-endian byte-swapping/bitmaps by 18ac27a0ecSDave Kleikamp * David S. Miller (davem@caip.rutgers.edu), 1995 19ac27a0ecSDave Kleikamp * 20ac27a0ecSDave Kleikamp * Hash Tree Directory indexing (c) 2001 Daniel Phillips 21ac27a0ecSDave Kleikamp * 22ac27a0ecSDave Kleikamp */ 23ac27a0ecSDave Kleikamp 24ac27a0ecSDave Kleikamp #include <linux/fs.h> 25dab291afSMingming Cao #include <linux/jbd2.h> 26ac27a0ecSDave Kleikamp #include <linux/buffer_head.h> 27ac27a0ecSDave Kleikamp #include <linux/slab.h> 28ac27a0ecSDave Kleikamp #include <linux/rbtree.h> 293dcf5451SChristoph Hellwig #include "ext4.h" 30ac27a0ecSDave Kleikamp 31617ba13bSMingming Cao static unsigned char ext4_filetype_table[] = { 32ac27a0ecSDave Kleikamp DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK 33ac27a0ecSDave Kleikamp }; 34ac27a0ecSDave Kleikamp 35617ba13bSMingming Cao static int ext4_readdir(struct file *, void *, filldir_t); 36617ba13bSMingming Cao static int ext4_dx_readdir(struct file *filp, 37ac27a0ecSDave Kleikamp void *dirent, filldir_t filldir); 38617ba13bSMingming Cao static int ext4_release_dir(struct inode *inode, 39ac27a0ecSDave Kleikamp struct file *filp); 40ac27a0ecSDave Kleikamp 41617ba13bSMingming Cao const struct file_operations ext4_dir_operations = { 42ac27a0ecSDave Kleikamp .llseek = generic_file_llseek, 43ac27a0ecSDave Kleikamp .read = generic_read_dir, 44617ba13bSMingming Cao .readdir = ext4_readdir, /* we take BKL. needed?*/ 455cdd7b2dSAndi Kleen .unlocked_ioctl = ext4_ioctl, 46ac27a0ecSDave Kleikamp #ifdef CONFIG_COMPAT 47617ba13bSMingming Cao .compat_ioctl = ext4_compat_ioctl, 48ac27a0ecSDave Kleikamp #endif 49642be6ecSAndi Kleen .fsync = ext4_sync_file, 50617ba13bSMingming Cao .release = ext4_release_dir, 51ac27a0ecSDave Kleikamp }; 52ac27a0ecSDave Kleikamp 53ac27a0ecSDave Kleikamp 54ac27a0ecSDave Kleikamp static unsigned char get_dtype(struct super_block *sb, int filetype) 55ac27a0ecSDave Kleikamp { 56617ba13bSMingming Cao if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) || 57617ba13bSMingming Cao (filetype >= EXT4_FT_MAX)) 58ac27a0ecSDave Kleikamp return DT_UNKNOWN; 59ac27a0ecSDave Kleikamp 60617ba13bSMingming Cao return (ext4_filetype_table[filetype]); 61ac27a0ecSDave Kleikamp } 62ac27a0ecSDave Kleikamp 63ac27a0ecSDave Kleikamp 64617ba13bSMingming Cao int ext4_check_dir_entry(const char *function, struct inode *dir, 65617ba13bSMingming Cao struct ext4_dir_entry_2 *de, 66ac27a0ecSDave Kleikamp struct buffer_head *bh, 67498e5f24STheodore Ts'o unsigned int offset) 68ac27a0ecSDave Kleikamp { 69ac27a0ecSDave Kleikamp const char *error_msg = NULL; 703d0518f4SWei Yongjun const int rlen = ext4_rec_len_from_disk(de->rec_len, 713d0518f4SWei Yongjun dir->i_sb->s_blocksize); 72ac27a0ecSDave Kleikamp 73617ba13bSMingming Cao if (rlen < EXT4_DIR_REC_LEN(1)) 74ac27a0ecSDave Kleikamp error_msg = "rec_len is smaller than minimal"; 75ac27a0ecSDave Kleikamp else if (rlen % 4 != 0) 76ac27a0ecSDave Kleikamp error_msg = "rec_len % 4 != 0"; 77617ba13bSMingming Cao else if (rlen < EXT4_DIR_REC_LEN(de->name_len)) 78ac27a0ecSDave Kleikamp error_msg = "rec_len is too small for name_len"; 79ac27a0ecSDave Kleikamp else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize) 80ac27a0ecSDave Kleikamp error_msg = "directory entry across blocks"; 81ac27a0ecSDave Kleikamp else if (le32_to_cpu(de->inode) > 82617ba13bSMingming Cao le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count)) 83ac27a0ecSDave Kleikamp error_msg = "inode out of bounds"; 84ac27a0ecSDave Kleikamp 85ac27a0ecSDave Kleikamp if (error_msg != NULL) 8624676da4STheodore Ts'o ext4_error_inode(function, dir, 8724676da4STheodore Ts'o "bad entry in directory: %s - block=%llu" 88b8b8afe2SToshiyuki Okajima "offset=%u(%u), inode=%u, rec_len=%d, name_len=%d", 8924676da4STheodore Ts'o error_msg, (unsigned long long) bh->b_blocknr, 90b8b8afe2SToshiyuki Okajima (unsigned) (offset%bh->b_size), offset, 91498e5f24STheodore Ts'o le32_to_cpu(de->inode), 92ac27a0ecSDave Kleikamp rlen, de->name_len); 93ac27a0ecSDave Kleikamp return error_msg == NULL ? 1 : 0; 94ac27a0ecSDave Kleikamp } 95ac27a0ecSDave Kleikamp 96617ba13bSMingming Cao static int ext4_readdir(struct file *filp, 97ac27a0ecSDave Kleikamp void *dirent, filldir_t filldir) 98ac27a0ecSDave Kleikamp { 99ac27a0ecSDave Kleikamp int error = 0; 100498e5f24STheodore Ts'o unsigned int offset; 101ac27a0ecSDave Kleikamp int i, stored; 102617ba13bSMingming Cao struct ext4_dir_entry_2 *de; 103ac27a0ecSDave Kleikamp struct super_block *sb; 104ac27a0ecSDave Kleikamp int err; 1059d549890SJosef "Jeff" Sipek struct inode *inode = filp->f_path.dentry->d_inode; 106ac27a0ecSDave Kleikamp int ret = 0; 1079d9f1775SEric Sandeen int dir_has_error = 0; 108ac27a0ecSDave Kleikamp 109ac27a0ecSDave Kleikamp sb = inode->i_sb; 110ac27a0ecSDave Kleikamp 111617ba13bSMingming Cao if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb, 112617ba13bSMingming Cao EXT4_FEATURE_COMPAT_DIR_INDEX) && 113617ba13bSMingming Cao ((EXT4_I(inode)->i_flags & EXT4_INDEX_FL) || 114ac27a0ecSDave Kleikamp ((inode->i_size >> sb->s_blocksize_bits) == 1))) { 115617ba13bSMingming Cao err = ext4_dx_readdir(filp, dirent, filldir); 116ac27a0ecSDave Kleikamp if (err != ERR_BAD_DX_DIR) { 117ac27a0ecSDave Kleikamp ret = err; 118ac27a0ecSDave Kleikamp goto out; 119ac27a0ecSDave Kleikamp } 120ac27a0ecSDave Kleikamp /* 121ac27a0ecSDave Kleikamp * We don't set the inode dirty flag since it's not 122ac27a0ecSDave Kleikamp * critical that it get flushed back to the disk. 123ac27a0ecSDave Kleikamp */ 1249d549890SJosef "Jeff" Sipek EXT4_I(filp->f_path.dentry->d_inode)->i_flags &= ~EXT4_INDEX_FL; 125ac27a0ecSDave Kleikamp } 126ac27a0ecSDave Kleikamp stored = 0; 127ac27a0ecSDave Kleikamp offset = filp->f_pos & (sb->s_blocksize - 1); 128ac27a0ecSDave Kleikamp 129ac27a0ecSDave Kleikamp while (!error && !stored && filp->f_pos < inode->i_size) { 1302ed88685STheodore Ts'o struct ext4_map_blocks map; 131ac27a0ecSDave Kleikamp struct buffer_head *bh = NULL; 132ac27a0ecSDave Kleikamp 1332ed88685STheodore Ts'o map.m_lblk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb); 1342ed88685STheodore Ts'o map.m_len = 1; 1352ed88685STheodore Ts'o err = ext4_map_blocks(NULL, inode, &map, 0); 136ac27a0ecSDave Kleikamp if (err > 0) { 1372ed88685STheodore Ts'o pgoff_t index = map.m_pblk >> 138dc7868fcSFengguang Wu (PAGE_CACHE_SHIFT - inode->i_blkbits); 139dc7868fcSFengguang Wu if (!ra_has_index(&filp->f_ra, index)) 140cf914a7dSRusty Russell page_cache_sync_readahead( 141dc7868fcSFengguang Wu sb->s_bdev->bd_inode->i_mapping, 142dc7868fcSFengguang Wu &filp->f_ra, filp, 143cf914a7dSRusty Russell index, 1); 144f4e6b498SFengguang Wu filp->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT; 1452ed88685STheodore Ts'o bh = ext4_bread(NULL, inode, map.m_lblk, 0, &err); 146ac27a0ecSDave Kleikamp } 147ac27a0ecSDave Kleikamp 148ac27a0ecSDave Kleikamp /* 149ac27a0ecSDave Kleikamp * We ignore I/O errors on directories so users have a chance 150ac27a0ecSDave Kleikamp * of recovering data when there's a bad sector 151ac27a0ecSDave Kleikamp */ 152ac27a0ecSDave Kleikamp if (!bh) { 1539d9f1775SEric Sandeen if (!dir_has_error) { 15424676da4STheodore Ts'o EXT4_ERROR_INODE(inode, "directory " 1559d9f1775SEric Sandeen "contains a hole at offset %Lu", 1569d9f1775SEric Sandeen (unsigned long long) filp->f_pos); 1579d9f1775SEric Sandeen dir_has_error = 1; 1589d9f1775SEric Sandeen } 159e6c40211SEric Sandeen /* corrupt size? Maybe no more blocks to read */ 160e6c40211SEric Sandeen if (filp->f_pos > inode->i_blocks << 9) 161e6c40211SEric Sandeen break; 162ac27a0ecSDave Kleikamp filp->f_pos += sb->s_blocksize - offset; 163ac27a0ecSDave Kleikamp continue; 164ac27a0ecSDave Kleikamp } 165ac27a0ecSDave Kleikamp 166ac27a0ecSDave Kleikamp revalidate: 167ac27a0ecSDave Kleikamp /* If the dir block has changed since the last call to 168ac27a0ecSDave Kleikamp * readdir(2), then we might be pointing to an invalid 169ac27a0ecSDave Kleikamp * dirent right now. Scan from the start of the block 170ac27a0ecSDave Kleikamp * to make sure. */ 171ac27a0ecSDave Kleikamp if (filp->f_version != inode->i_version) { 172ac27a0ecSDave Kleikamp for (i = 0; i < sb->s_blocksize && i < offset; ) { 173617ba13bSMingming Cao de = (struct ext4_dir_entry_2 *) 174ac27a0ecSDave Kleikamp (bh->b_data + i); 175ac27a0ecSDave Kleikamp /* It's too expensive to do a full 176ac27a0ecSDave Kleikamp * dirent test each time round this 177ac27a0ecSDave Kleikamp * loop, but we do have to test at 178ac27a0ecSDave Kleikamp * least that it is non-zero. A 179ac27a0ecSDave Kleikamp * failure will be detected in the 180ac27a0ecSDave Kleikamp * dirent test below. */ 1813d0518f4SWei Yongjun if (ext4_rec_len_from_disk(de->rec_len, 1823d0518f4SWei Yongjun sb->s_blocksize) < EXT4_DIR_REC_LEN(1)) 183ac27a0ecSDave Kleikamp break; 1843d0518f4SWei Yongjun i += ext4_rec_len_from_disk(de->rec_len, 1853d0518f4SWei Yongjun sb->s_blocksize); 186ac27a0ecSDave Kleikamp } 187ac27a0ecSDave Kleikamp offset = i; 188ac27a0ecSDave Kleikamp filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1)) 189ac27a0ecSDave Kleikamp | offset; 190ac27a0ecSDave Kleikamp filp->f_version = inode->i_version; 191ac27a0ecSDave Kleikamp } 192ac27a0ecSDave Kleikamp 193ac27a0ecSDave Kleikamp while (!error && filp->f_pos < inode->i_size 194ac27a0ecSDave Kleikamp && offset < sb->s_blocksize) { 195617ba13bSMingming Cao de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); 196617ba13bSMingming Cao if (!ext4_check_dir_entry("ext4_readdir", inode, de, 197ac27a0ecSDave Kleikamp bh, offset)) { 19863f57933SAndrew Morton /* 19963f57933SAndrew Morton * On error, skip the f_pos to the next block 20063f57933SAndrew Morton */ 201ac27a0ecSDave Kleikamp filp->f_pos = (filp->f_pos | 202ac27a0ecSDave Kleikamp (sb->s_blocksize - 1)) + 1; 203ac27a0ecSDave Kleikamp brelse(bh); 204ac27a0ecSDave Kleikamp ret = stored; 205ac27a0ecSDave Kleikamp goto out; 206ac27a0ecSDave Kleikamp } 2073d0518f4SWei Yongjun offset += ext4_rec_len_from_disk(de->rec_len, 2083d0518f4SWei Yongjun sb->s_blocksize); 209ac27a0ecSDave Kleikamp if (le32_to_cpu(de->inode)) { 210ac27a0ecSDave Kleikamp /* We might block in the next section 211ac27a0ecSDave Kleikamp * if the data destination is 212ac27a0ecSDave Kleikamp * currently swapped out. So, use a 213ac27a0ecSDave Kleikamp * version stamp to detect whether or 214ac27a0ecSDave Kleikamp * not the directory has been modified 215ac27a0ecSDave Kleikamp * during the copy operation. 216ac27a0ecSDave Kleikamp */ 2172b47c361SMathieu Desnoyers u64 version = filp->f_version; 218ac27a0ecSDave Kleikamp 219ac27a0ecSDave Kleikamp error = filldir(dirent, de->name, 220ac27a0ecSDave Kleikamp de->name_len, 221ac27a0ecSDave Kleikamp filp->f_pos, 222ac27a0ecSDave Kleikamp le32_to_cpu(de->inode), 223ac27a0ecSDave Kleikamp get_dtype(sb, de->file_type)); 224ac27a0ecSDave Kleikamp if (error) 225ac27a0ecSDave Kleikamp break; 226ac27a0ecSDave Kleikamp if (version != filp->f_version) 227ac27a0ecSDave Kleikamp goto revalidate; 228ac27a0ecSDave Kleikamp stored++; 229ac27a0ecSDave Kleikamp } 2303d0518f4SWei Yongjun filp->f_pos += ext4_rec_len_from_disk(de->rec_len, 2313d0518f4SWei Yongjun sb->s_blocksize); 232ac27a0ecSDave Kleikamp } 233ac27a0ecSDave Kleikamp offset = 0; 234ac27a0ecSDave Kleikamp brelse(bh); 235ac27a0ecSDave Kleikamp } 236ac27a0ecSDave Kleikamp out: 237ac27a0ecSDave Kleikamp return ret; 238ac27a0ecSDave Kleikamp } 239ac27a0ecSDave Kleikamp 240ac27a0ecSDave Kleikamp /* 241ac27a0ecSDave Kleikamp * These functions convert from the major/minor hash to an f_pos 242ac27a0ecSDave Kleikamp * value. 243ac27a0ecSDave Kleikamp * 244ac27a0ecSDave Kleikamp * Currently we only use major hash numer. This is unfortunate, but 245ac27a0ecSDave Kleikamp * on 32-bit machines, the same VFS interface is used for lseek and 246ac27a0ecSDave Kleikamp * llseek, so if we use the 64 bit offset, then the 32-bit versions of 247ac27a0ecSDave Kleikamp * lseek/telldir/seekdir will blow out spectacularly, and from within 248ac27a0ecSDave Kleikamp * the ext2 low-level routine, we don't know if we're being called by 249ac27a0ecSDave Kleikamp * a 64-bit version of the system call or the 32-bit version of the 250ac27a0ecSDave Kleikamp * system call. Worse yet, NFSv2 only allows for a 32-bit readdir 251ac27a0ecSDave Kleikamp * cookie. Sigh. 252ac27a0ecSDave Kleikamp */ 253ac27a0ecSDave Kleikamp #define hash2pos(major, minor) (major >> 1) 254ac27a0ecSDave Kleikamp #define pos2maj_hash(pos) ((pos << 1) & 0xffffffff) 255ac27a0ecSDave Kleikamp #define pos2min_hash(pos) (0) 256ac27a0ecSDave Kleikamp 257ac27a0ecSDave Kleikamp /* 258ac27a0ecSDave Kleikamp * This structure holds the nodes of the red-black tree used to store 259ac27a0ecSDave Kleikamp * the directory entry in hash order. 260ac27a0ecSDave Kleikamp */ 261ac27a0ecSDave Kleikamp struct fname { 262ac27a0ecSDave Kleikamp __u32 hash; 263ac27a0ecSDave Kleikamp __u32 minor_hash; 264ac27a0ecSDave Kleikamp struct rb_node rb_hash; 265ac27a0ecSDave Kleikamp struct fname *next; 266ac27a0ecSDave Kleikamp __u32 inode; 267ac27a0ecSDave Kleikamp __u8 name_len; 268ac27a0ecSDave Kleikamp __u8 file_type; 269ac27a0ecSDave Kleikamp char name[0]; 270ac27a0ecSDave Kleikamp }; 271ac27a0ecSDave Kleikamp 272ac27a0ecSDave Kleikamp /* 273ac27a0ecSDave Kleikamp * This functoin implements a non-recursive way of freeing all of the 274ac27a0ecSDave Kleikamp * nodes in the red-black tree. 275ac27a0ecSDave Kleikamp */ 276ac27a0ecSDave Kleikamp static void free_rb_tree_fname(struct rb_root *root) 277ac27a0ecSDave Kleikamp { 278ac27a0ecSDave Kleikamp struct rb_node *n = root->rb_node; 279ac27a0ecSDave Kleikamp struct rb_node *parent; 280ac27a0ecSDave Kleikamp struct fname *fname; 281ac27a0ecSDave Kleikamp 282ac27a0ecSDave Kleikamp while (n) { 283ac27a0ecSDave Kleikamp /* Do the node's children first */ 28469baee06SShen Feng if (n->rb_left) { 285ac27a0ecSDave Kleikamp n = n->rb_left; 286ac27a0ecSDave Kleikamp continue; 287ac27a0ecSDave Kleikamp } 288ac27a0ecSDave Kleikamp if (n->rb_right) { 289ac27a0ecSDave Kleikamp n = n->rb_right; 290ac27a0ecSDave Kleikamp continue; 291ac27a0ecSDave Kleikamp } 292ac27a0ecSDave Kleikamp /* 293ac27a0ecSDave Kleikamp * The node has no children; free it, and then zero 294ac27a0ecSDave Kleikamp * out parent's link to it. Finally go to the 295ac27a0ecSDave Kleikamp * beginning of the loop and try to free the parent 296ac27a0ecSDave Kleikamp * node. 297ac27a0ecSDave Kleikamp */ 298ac27a0ecSDave Kleikamp parent = rb_parent(n); 299ac27a0ecSDave Kleikamp fname = rb_entry(n, struct fname, rb_hash); 300ac27a0ecSDave Kleikamp while (fname) { 301ac27a0ecSDave Kleikamp struct fname *old = fname; 302ac27a0ecSDave Kleikamp fname = fname->next; 303ac27a0ecSDave Kleikamp kfree(old); 304ac27a0ecSDave Kleikamp } 305ac27a0ecSDave Kleikamp if (!parent) 30664e290ecSVenkatesh Pallipadi *root = RB_ROOT; 307ac27a0ecSDave Kleikamp else if (parent->rb_left == n) 308ac27a0ecSDave Kleikamp parent->rb_left = NULL; 309ac27a0ecSDave Kleikamp else if (parent->rb_right == n) 310ac27a0ecSDave Kleikamp parent->rb_right = NULL; 311ac27a0ecSDave Kleikamp n = parent; 312ac27a0ecSDave Kleikamp } 313ac27a0ecSDave Kleikamp } 314ac27a0ecSDave Kleikamp 315ac27a0ecSDave Kleikamp 31669baee06SShen Feng static struct dir_private_info *ext4_htree_create_dir_info(loff_t pos) 317ac27a0ecSDave Kleikamp { 318ac27a0ecSDave Kleikamp struct dir_private_info *p; 319ac27a0ecSDave Kleikamp 32069baee06SShen Feng p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL); 321ac27a0ecSDave Kleikamp if (!p) 322ac27a0ecSDave Kleikamp return NULL; 323ac27a0ecSDave Kleikamp p->curr_hash = pos2maj_hash(pos); 324ac27a0ecSDave Kleikamp p->curr_minor_hash = pos2min_hash(pos); 325ac27a0ecSDave Kleikamp return p; 326ac27a0ecSDave Kleikamp } 327ac27a0ecSDave Kleikamp 328617ba13bSMingming Cao void ext4_htree_free_dir_info(struct dir_private_info *p) 329ac27a0ecSDave Kleikamp { 330ac27a0ecSDave Kleikamp free_rb_tree_fname(&p->root); 331ac27a0ecSDave Kleikamp kfree(p); 332ac27a0ecSDave Kleikamp } 333ac27a0ecSDave Kleikamp 334ac27a0ecSDave Kleikamp /* 335ac27a0ecSDave Kleikamp * Given a directory entry, enter it into the fname rb tree. 336ac27a0ecSDave Kleikamp */ 337617ba13bSMingming Cao int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, 338ac27a0ecSDave Kleikamp __u32 minor_hash, 339617ba13bSMingming Cao struct ext4_dir_entry_2 *dirent) 340ac27a0ecSDave Kleikamp { 341ac27a0ecSDave Kleikamp struct rb_node **p, *parent = NULL; 342ac27a0ecSDave Kleikamp struct fname *fname, *new_fn; 343ac27a0ecSDave Kleikamp struct dir_private_info *info; 344ac27a0ecSDave Kleikamp int len; 345ac27a0ecSDave Kleikamp 346ac27a0ecSDave Kleikamp info = (struct dir_private_info *) dir_file->private_data; 347ac27a0ecSDave Kleikamp p = &info->root.rb_node; 348ac27a0ecSDave Kleikamp 349ac27a0ecSDave Kleikamp /* Create and allocate the fname structure */ 350ac27a0ecSDave Kleikamp len = sizeof(struct fname) + dirent->name_len + 1; 351ac27a0ecSDave Kleikamp new_fn = kzalloc(len, GFP_KERNEL); 352ac27a0ecSDave Kleikamp if (!new_fn) 353ac27a0ecSDave Kleikamp return -ENOMEM; 354ac27a0ecSDave Kleikamp new_fn->hash = hash; 355ac27a0ecSDave Kleikamp new_fn->minor_hash = minor_hash; 356ac27a0ecSDave Kleikamp new_fn->inode = le32_to_cpu(dirent->inode); 357ac27a0ecSDave Kleikamp new_fn->name_len = dirent->name_len; 358ac27a0ecSDave Kleikamp new_fn->file_type = dirent->file_type; 359ac27a0ecSDave Kleikamp memcpy(new_fn->name, dirent->name, dirent->name_len); 360ac27a0ecSDave Kleikamp new_fn->name[dirent->name_len] = 0; 361ac27a0ecSDave Kleikamp 362ac27a0ecSDave Kleikamp while (*p) { 363ac27a0ecSDave Kleikamp parent = *p; 364ac27a0ecSDave Kleikamp fname = rb_entry(parent, struct fname, rb_hash); 365ac27a0ecSDave Kleikamp 366ac27a0ecSDave Kleikamp /* 367ac27a0ecSDave Kleikamp * If the hash and minor hash match up, then we put 368ac27a0ecSDave Kleikamp * them on a linked list. This rarely happens... 369ac27a0ecSDave Kleikamp */ 370ac27a0ecSDave Kleikamp if ((new_fn->hash == fname->hash) && 371ac27a0ecSDave Kleikamp (new_fn->minor_hash == fname->minor_hash)) { 372ac27a0ecSDave Kleikamp new_fn->next = fname->next; 373ac27a0ecSDave Kleikamp fname->next = new_fn; 374ac27a0ecSDave Kleikamp return 0; 375ac27a0ecSDave Kleikamp } 376ac27a0ecSDave Kleikamp 377ac27a0ecSDave Kleikamp if (new_fn->hash < fname->hash) 378ac27a0ecSDave Kleikamp p = &(*p)->rb_left; 379ac27a0ecSDave Kleikamp else if (new_fn->hash > fname->hash) 380ac27a0ecSDave Kleikamp p = &(*p)->rb_right; 381ac27a0ecSDave Kleikamp else if (new_fn->minor_hash < fname->minor_hash) 382ac27a0ecSDave Kleikamp p = &(*p)->rb_left; 383ac27a0ecSDave Kleikamp else /* if (new_fn->minor_hash > fname->minor_hash) */ 384ac27a0ecSDave Kleikamp p = &(*p)->rb_right; 385ac27a0ecSDave Kleikamp } 386ac27a0ecSDave Kleikamp 387ac27a0ecSDave Kleikamp rb_link_node(&new_fn->rb_hash, parent, p); 388ac27a0ecSDave Kleikamp rb_insert_color(&new_fn->rb_hash, &info->root); 389ac27a0ecSDave Kleikamp return 0; 390ac27a0ecSDave Kleikamp } 391ac27a0ecSDave Kleikamp 392ac27a0ecSDave Kleikamp 393ac27a0ecSDave Kleikamp 394ac27a0ecSDave Kleikamp /* 395617ba13bSMingming Cao * This is a helper function for ext4_dx_readdir. It calls filldir 396ac27a0ecSDave Kleikamp * for all entres on the fname linked list. (Normally there is only 397ac27a0ecSDave Kleikamp * one entry on the linked list, unless there are 62 bit hash collisions.) 398ac27a0ecSDave Kleikamp */ 399ac27a0ecSDave Kleikamp static int call_filldir(struct file *filp, void *dirent, 400ac27a0ecSDave Kleikamp filldir_t filldir, struct fname *fname) 401ac27a0ecSDave Kleikamp { 402ac27a0ecSDave Kleikamp struct dir_private_info *info = filp->private_data; 403ac27a0ecSDave Kleikamp loff_t curr_pos; 4049d549890SJosef "Jeff" Sipek struct inode *inode = filp->f_path.dentry->d_inode; 405ac27a0ecSDave Kleikamp struct super_block *sb; 406ac27a0ecSDave Kleikamp int error; 407ac27a0ecSDave Kleikamp 408ac27a0ecSDave Kleikamp sb = inode->i_sb; 409ac27a0ecSDave Kleikamp 410ac27a0ecSDave Kleikamp if (!fname) { 411abda1418STheodore Ts'o printk(KERN_ERR "EXT4-fs: call_filldir: called with " 4124776004fSTheodore Ts'o "null fname?!?\n"); 413ac27a0ecSDave Kleikamp return 0; 414ac27a0ecSDave Kleikamp } 415ac27a0ecSDave Kleikamp curr_pos = hash2pos(fname->hash, fname->minor_hash); 416ac27a0ecSDave Kleikamp while (fname) { 417ac27a0ecSDave Kleikamp error = filldir(dirent, fname->name, 418ac27a0ecSDave Kleikamp fname->name_len, curr_pos, 419ac27a0ecSDave Kleikamp fname->inode, 420ac27a0ecSDave Kleikamp get_dtype(sb, fname->file_type)); 421ac27a0ecSDave Kleikamp if (error) { 422ac27a0ecSDave Kleikamp filp->f_pos = curr_pos; 423d0156417STheodore Ts'o info->extra_fname = fname; 424ac27a0ecSDave Kleikamp return error; 425ac27a0ecSDave Kleikamp } 426ac27a0ecSDave Kleikamp fname = fname->next; 427ac27a0ecSDave Kleikamp } 428ac27a0ecSDave Kleikamp return 0; 429ac27a0ecSDave Kleikamp } 430ac27a0ecSDave Kleikamp 431617ba13bSMingming Cao static int ext4_dx_readdir(struct file *filp, 432ac27a0ecSDave Kleikamp void *dirent, filldir_t filldir) 433ac27a0ecSDave Kleikamp { 434ac27a0ecSDave Kleikamp struct dir_private_info *info = filp->private_data; 4359d549890SJosef "Jeff" Sipek struct inode *inode = filp->f_path.dentry->d_inode; 436ac27a0ecSDave Kleikamp struct fname *fname; 437ac27a0ecSDave Kleikamp int ret; 438ac27a0ecSDave Kleikamp 439ac27a0ecSDave Kleikamp if (!info) { 44069baee06SShen Feng info = ext4_htree_create_dir_info(filp->f_pos); 441ac27a0ecSDave Kleikamp if (!info) 442ac27a0ecSDave Kleikamp return -ENOMEM; 443ac27a0ecSDave Kleikamp filp->private_data = info; 444ac27a0ecSDave Kleikamp } 445ac27a0ecSDave Kleikamp 446617ba13bSMingming Cao if (filp->f_pos == EXT4_HTREE_EOF) 447ac27a0ecSDave Kleikamp return 0; /* EOF */ 448ac27a0ecSDave Kleikamp 449ac27a0ecSDave Kleikamp /* Some one has messed with f_pos; reset the world */ 450ac27a0ecSDave Kleikamp if (info->last_pos != filp->f_pos) { 451ac27a0ecSDave Kleikamp free_rb_tree_fname(&info->root); 452ac27a0ecSDave Kleikamp info->curr_node = NULL; 453ac27a0ecSDave Kleikamp info->extra_fname = NULL; 454ac27a0ecSDave Kleikamp info->curr_hash = pos2maj_hash(filp->f_pos); 455ac27a0ecSDave Kleikamp info->curr_minor_hash = pos2min_hash(filp->f_pos); 456ac27a0ecSDave Kleikamp } 457ac27a0ecSDave Kleikamp 458ac27a0ecSDave Kleikamp /* 459ac27a0ecSDave Kleikamp * If there are any leftover names on the hash collision 460ac27a0ecSDave Kleikamp * chain, return them first. 461ac27a0ecSDave Kleikamp */ 462d0156417STheodore Ts'o if (info->extra_fname) { 463d0156417STheodore Ts'o if (call_filldir(filp, dirent, filldir, info->extra_fname)) 464ac27a0ecSDave Kleikamp goto finished; 465d0156417STheodore Ts'o info->extra_fname = NULL; 4663c37fc86STheodore Ts'o goto next_node; 467d0156417STheodore Ts'o } else if (!info->curr_node) 468ac27a0ecSDave Kleikamp info->curr_node = rb_first(&info->root); 469ac27a0ecSDave Kleikamp 470ac27a0ecSDave Kleikamp while (1) { 471ac27a0ecSDave Kleikamp /* 472ac27a0ecSDave Kleikamp * Fill the rbtree if we have no more entries, 473ac27a0ecSDave Kleikamp * or the inode has changed since we last read in the 474ac27a0ecSDave Kleikamp * cached entries. 475ac27a0ecSDave Kleikamp */ 476ac27a0ecSDave Kleikamp if ((!info->curr_node) || 477ac27a0ecSDave Kleikamp (filp->f_version != inode->i_version)) { 478ac27a0ecSDave Kleikamp info->curr_node = NULL; 479ac27a0ecSDave Kleikamp free_rb_tree_fname(&info->root); 480ac27a0ecSDave Kleikamp filp->f_version = inode->i_version; 481617ba13bSMingming Cao ret = ext4_htree_fill_tree(filp, info->curr_hash, 482ac27a0ecSDave Kleikamp info->curr_minor_hash, 483ac27a0ecSDave Kleikamp &info->next_hash); 484ac27a0ecSDave Kleikamp if (ret < 0) 485ac27a0ecSDave Kleikamp return ret; 486ac27a0ecSDave Kleikamp if (ret == 0) { 487617ba13bSMingming Cao filp->f_pos = EXT4_HTREE_EOF; 488ac27a0ecSDave Kleikamp break; 489ac27a0ecSDave Kleikamp } 490ac27a0ecSDave Kleikamp info->curr_node = rb_first(&info->root); 491ac27a0ecSDave Kleikamp } 492ac27a0ecSDave Kleikamp 493ac27a0ecSDave Kleikamp fname = rb_entry(info->curr_node, struct fname, rb_hash); 494ac27a0ecSDave Kleikamp info->curr_hash = fname->hash; 495ac27a0ecSDave Kleikamp info->curr_minor_hash = fname->minor_hash; 496ac27a0ecSDave Kleikamp if (call_filldir(filp, dirent, filldir, fname)) 497ac27a0ecSDave Kleikamp break; 4983c37fc86STheodore Ts'o next_node: 499ac27a0ecSDave Kleikamp info->curr_node = rb_next(info->curr_node); 5003c37fc86STheodore Ts'o if (info->curr_node) { 5013c37fc86STheodore Ts'o fname = rb_entry(info->curr_node, struct fname, 5023c37fc86STheodore Ts'o rb_hash); 5033c37fc86STheodore Ts'o info->curr_hash = fname->hash; 5043c37fc86STheodore Ts'o info->curr_minor_hash = fname->minor_hash; 5053c37fc86STheodore Ts'o } else { 506ac27a0ecSDave Kleikamp if (info->next_hash == ~0) { 507617ba13bSMingming Cao filp->f_pos = EXT4_HTREE_EOF; 508ac27a0ecSDave Kleikamp break; 509ac27a0ecSDave Kleikamp } 510ac27a0ecSDave Kleikamp info->curr_hash = info->next_hash; 511ac27a0ecSDave Kleikamp info->curr_minor_hash = 0; 512ac27a0ecSDave Kleikamp } 513ac27a0ecSDave Kleikamp } 514ac27a0ecSDave Kleikamp finished: 515ac27a0ecSDave Kleikamp info->last_pos = filp->f_pos; 516ac27a0ecSDave Kleikamp return 0; 517ac27a0ecSDave Kleikamp } 518ac27a0ecSDave Kleikamp 519617ba13bSMingming Cao static int ext4_release_dir(struct inode *inode, struct file *filp) 520ac27a0ecSDave Kleikamp { 521ac27a0ecSDave Kleikamp if (filp->private_data) 522617ba13bSMingming Cao ext4_htree_free_dir_info(filp->private_data); 523ac27a0ecSDave Kleikamp 524ac27a0ecSDave Kleikamp return 0; 525ac27a0ecSDave Kleikamp } 526