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" 3065d165d9STao Ma #include "xattr.h" 31ac27a0ecSDave Kleikamp 32617ba13bSMingming Cao static int ext4_dx_readdir(struct file *filp, 33ac27a0ecSDave Kleikamp void *dirent, filldir_t filldir); 34ac27a0ecSDave Kleikamp 35d1f5273eSFan Yong /** 36d1f5273eSFan Yong * Check if the given dir-inode refers to an htree-indexed directory 37d1f5273eSFan Yong * (or a directory which chould potentially get coverted to use htree 38d1f5273eSFan Yong * indexing). 39d1f5273eSFan Yong * 40d1f5273eSFan Yong * Return 1 if it is a dx dir, 0 if not 41d1f5273eSFan Yong */ 42d1f5273eSFan Yong static int is_dx_dir(struct inode *inode) 43d1f5273eSFan Yong { 44d1f5273eSFan Yong struct super_block *sb = inode->i_sb; 45d1f5273eSFan Yong 46d1f5273eSFan Yong if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb, 47d1f5273eSFan Yong EXT4_FEATURE_COMPAT_DIR_INDEX) && 48d1f5273eSFan Yong ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) || 49d1f5273eSFan Yong ((inode->i_size >> sb->s_blocksize_bits) == 1))) 50d1f5273eSFan Yong return 1; 51d1f5273eSFan Yong 52d1f5273eSFan Yong return 0; 53d1f5273eSFan Yong } 54d1f5273eSFan Yong 55cad3f007STheodore Ts'o /* 56cad3f007STheodore Ts'o * Return 0 if the directory entry is OK, and 1 if there is a problem 57cad3f007STheodore Ts'o * 58cad3f007STheodore Ts'o * Note: this is the opposite of what ext2 and ext3 historically returned... 5965d165d9STao Ma * 6065d165d9STao Ma * bh passed here can be an inode block or a dir data block, depending 6165d165d9STao Ma * on the inode inline data flag. 62cad3f007STheodore Ts'o */ 6360fd4da3STheodore Ts'o int __ext4_check_dir_entry(const char *function, unsigned int line, 64f7c21177STheodore Ts'o struct inode *dir, struct file *filp, 65617ba13bSMingming Cao struct ext4_dir_entry_2 *de, 66226ba972STao Ma struct buffer_head *bh, char *buf, int size, 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 73cad3f007STheodore Ts'o if (unlikely(rlen < EXT4_DIR_REC_LEN(1))) 74ac27a0ecSDave Kleikamp error_msg = "rec_len is smaller than minimal"; 75cad3f007STheodore Ts'o else if (unlikely(rlen % 4 != 0)) 76ac27a0ecSDave Kleikamp error_msg = "rec_len % 4 != 0"; 77cad3f007STheodore Ts'o else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len))) 78ac27a0ecSDave Kleikamp error_msg = "rec_len is too small for name_len"; 79226ba972STao Ma else if (unlikely(((char *) de - buf) + rlen > size)) 80226ba972STao Ma error_msg = "directory entry across range"; 81cad3f007STheodore Ts'o else if (unlikely(le32_to_cpu(de->inode) > 82cad3f007STheodore Ts'o le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))) 83ac27a0ecSDave Kleikamp error_msg = "inode out of bounds"; 84cad3f007STheodore Ts'o else 85cad3f007STheodore Ts'o return 0; 86ac27a0ecSDave Kleikamp 87f7c21177STheodore Ts'o if (filp) 884fda4003SDan Carpenter ext4_error_file(filp, function, line, bh->b_blocknr, 89f7c21177STheodore Ts'o "bad entry in directory: %s - offset=%u(%u), " 90f7c21177STheodore Ts'o "inode=%u, rec_len=%d, name_len=%d", 91226ba972STao Ma error_msg, (unsigned) (offset % size), 92f7c21177STheodore Ts'o offset, le32_to_cpu(de->inode), 93ac27a0ecSDave Kleikamp rlen, de->name_len); 94f7c21177STheodore Ts'o else 954fda4003SDan Carpenter ext4_error_inode(dir, function, line, bh->b_blocknr, 96f7c21177STheodore Ts'o "bad entry in directory: %s - offset=%u(%u), " 97f7c21177STheodore Ts'o "inode=%u, rec_len=%d, name_len=%d", 98226ba972STao Ma error_msg, (unsigned) (offset % size), 99f7c21177STheodore Ts'o offset, le32_to_cpu(de->inode), 100f7c21177STheodore Ts'o rlen, de->name_len); 101f7c21177STheodore Ts'o 102cad3f007STheodore Ts'o return 1; 103ac27a0ecSDave Kleikamp } 104ac27a0ecSDave Kleikamp 105617ba13bSMingming Cao static int ext4_readdir(struct file *filp, 106ac27a0ecSDave Kleikamp void *dirent, filldir_t filldir) 107ac27a0ecSDave Kleikamp { 108ac27a0ecSDave Kleikamp int error = 0; 109498e5f24STheodore Ts'o unsigned int offset; 110ac27a0ecSDave Kleikamp int i, stored; 111617ba13bSMingming Cao struct ext4_dir_entry_2 *de; 112ac27a0ecSDave Kleikamp int err; 1139d549890SJosef "Jeff" Sipek struct inode *inode = filp->f_path.dentry->d_inode; 114d1f5273eSFan Yong struct super_block *sb = inode->i_sb; 115ac27a0ecSDave Kleikamp int ret = 0; 1169d9f1775SEric Sandeen int dir_has_error = 0; 117ac27a0ecSDave Kleikamp 11865d165d9STao Ma if (ext4_has_inline_data(inode)) { 11965d165d9STao Ma int has_inline_data = 1; 12065d165d9STao Ma ret = ext4_read_inline_dir(filp, dirent, filldir, 12165d165d9STao Ma &has_inline_data); 12265d165d9STao Ma if (has_inline_data) 12365d165d9STao Ma return ret; 12465d165d9STao Ma } 12565d165d9STao Ma 126d1f5273eSFan Yong if (is_dx_dir(inode)) { 127617ba13bSMingming Cao err = ext4_dx_readdir(filp, dirent, filldir); 128ac27a0ecSDave Kleikamp if (err != ERR_BAD_DX_DIR) { 129ac27a0ecSDave Kleikamp ret = err; 130ac27a0ecSDave Kleikamp goto out; 131ac27a0ecSDave Kleikamp } 132ac27a0ecSDave Kleikamp /* 133ac27a0ecSDave Kleikamp * We don't set the inode dirty flag since it's not 134ac27a0ecSDave Kleikamp * critical that it get flushed back to the disk. 135ac27a0ecSDave Kleikamp */ 13607a03824STheodore Ts'o ext4_clear_inode_flag(filp->f_path.dentry->d_inode, 13707a03824STheodore Ts'o EXT4_INODE_INDEX); 138ac27a0ecSDave Kleikamp } 139ac27a0ecSDave Kleikamp stored = 0; 140ac27a0ecSDave Kleikamp offset = filp->f_pos & (sb->s_blocksize - 1); 141ac27a0ecSDave Kleikamp 142ac27a0ecSDave Kleikamp while (!error && !stored && filp->f_pos < inode->i_size) { 1432ed88685STheodore Ts'o struct ext4_map_blocks map; 144ac27a0ecSDave Kleikamp struct buffer_head *bh = NULL; 145ac27a0ecSDave Kleikamp 1462ed88685STheodore Ts'o map.m_lblk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb); 1472ed88685STheodore Ts'o map.m_len = 1; 1482ed88685STheodore Ts'o err = ext4_map_blocks(NULL, inode, &map, 0); 149ac27a0ecSDave Kleikamp if (err > 0) { 1502ed88685STheodore Ts'o pgoff_t index = map.m_pblk >> 151dc7868fcSFengguang Wu (PAGE_CACHE_SHIFT - inode->i_blkbits); 152dc7868fcSFengguang Wu if (!ra_has_index(&filp->f_ra, index)) 153cf914a7dSRusty Russell page_cache_sync_readahead( 154dc7868fcSFengguang Wu sb->s_bdev->bd_inode->i_mapping, 155dc7868fcSFengguang Wu &filp->f_ra, filp, 156cf914a7dSRusty Russell index, 1); 157f4e6b498SFengguang Wu filp->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT; 1582ed88685STheodore Ts'o bh = ext4_bread(NULL, inode, map.m_lblk, 0, &err); 159ac27a0ecSDave Kleikamp } 160ac27a0ecSDave Kleikamp 161ac27a0ecSDave Kleikamp /* 162ac27a0ecSDave Kleikamp * We ignore I/O errors on directories so users have a chance 163ac27a0ecSDave Kleikamp * of recovering data when there's a bad sector 164ac27a0ecSDave Kleikamp */ 165ac27a0ecSDave Kleikamp if (!bh) { 1669d9f1775SEric Sandeen if (!dir_has_error) { 167f7c21177STheodore Ts'o EXT4_ERROR_FILE(filp, 0, 168f7c21177STheodore Ts'o "directory contains a " 169f7c21177STheodore Ts'o "hole at offset %llu", 1709d9f1775SEric Sandeen (unsigned long long) filp->f_pos); 1719d9f1775SEric Sandeen dir_has_error = 1; 1729d9f1775SEric Sandeen } 173e6c40211SEric Sandeen /* corrupt size? Maybe no more blocks to read */ 174e6c40211SEric Sandeen if (filp->f_pos > inode->i_blocks << 9) 175e6c40211SEric Sandeen break; 176ac27a0ecSDave Kleikamp filp->f_pos += sb->s_blocksize - offset; 177ac27a0ecSDave Kleikamp continue; 178ac27a0ecSDave Kleikamp } 179ac27a0ecSDave Kleikamp 180b0336e8dSDarrick J. Wong /* Check the checksum */ 181b0336e8dSDarrick J. Wong if (!buffer_verified(bh) && 182b0336e8dSDarrick J. Wong !ext4_dirent_csum_verify(inode, 183b0336e8dSDarrick J. Wong (struct ext4_dir_entry *)bh->b_data)) { 184b0336e8dSDarrick J. Wong EXT4_ERROR_FILE(filp, 0, "directory fails checksum " 185b0336e8dSDarrick J. Wong "at offset %llu", 186b0336e8dSDarrick J. Wong (unsigned long long)filp->f_pos); 187b0336e8dSDarrick J. Wong filp->f_pos += sb->s_blocksize - offset; 188b0336e8dSDarrick J. Wong continue; 189b0336e8dSDarrick J. Wong } 190b0336e8dSDarrick J. Wong set_buffer_verified(bh); 191b0336e8dSDarrick J. Wong 192ac27a0ecSDave Kleikamp revalidate: 193ac27a0ecSDave Kleikamp /* If the dir block has changed since the last call to 194ac27a0ecSDave Kleikamp * readdir(2), then we might be pointing to an invalid 195ac27a0ecSDave Kleikamp * dirent right now. Scan from the start of the block 196ac27a0ecSDave Kleikamp * to make sure. */ 197ac27a0ecSDave Kleikamp if (filp->f_version != inode->i_version) { 198ac27a0ecSDave Kleikamp for (i = 0; i < sb->s_blocksize && i < offset; ) { 199617ba13bSMingming Cao de = (struct ext4_dir_entry_2 *) 200ac27a0ecSDave Kleikamp (bh->b_data + i); 201ac27a0ecSDave Kleikamp /* It's too expensive to do a full 202ac27a0ecSDave Kleikamp * dirent test each time round this 203ac27a0ecSDave Kleikamp * loop, but we do have to test at 204ac27a0ecSDave Kleikamp * least that it is non-zero. A 205ac27a0ecSDave Kleikamp * failure will be detected in the 206ac27a0ecSDave Kleikamp * dirent test below. */ 2073d0518f4SWei Yongjun if (ext4_rec_len_from_disk(de->rec_len, 2083d0518f4SWei Yongjun sb->s_blocksize) < EXT4_DIR_REC_LEN(1)) 209ac27a0ecSDave Kleikamp break; 2103d0518f4SWei Yongjun i += ext4_rec_len_from_disk(de->rec_len, 2113d0518f4SWei Yongjun sb->s_blocksize); 212ac27a0ecSDave Kleikamp } 213ac27a0ecSDave Kleikamp offset = i; 214ac27a0ecSDave Kleikamp filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1)) 215ac27a0ecSDave Kleikamp | offset; 216ac27a0ecSDave Kleikamp filp->f_version = inode->i_version; 217ac27a0ecSDave Kleikamp } 218ac27a0ecSDave Kleikamp 219ac27a0ecSDave Kleikamp while (!error && filp->f_pos < inode->i_size 220ac27a0ecSDave Kleikamp && offset < sb->s_blocksize) { 221617ba13bSMingming Cao de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); 222226ba972STao Ma if (ext4_check_dir_entry(inode, filp, de, bh, 223226ba972STao Ma bh->b_data, bh->b_size, 224226ba972STao Ma offset)) { 22563f57933SAndrew Morton /* 22663f57933SAndrew Morton * On error, skip the f_pos to the next block 22763f57933SAndrew Morton */ 228ac27a0ecSDave Kleikamp filp->f_pos = (filp->f_pos | 229ac27a0ecSDave Kleikamp (sb->s_blocksize - 1)) + 1; 230ac27a0ecSDave Kleikamp brelse(bh); 231ac27a0ecSDave Kleikamp ret = stored; 232ac27a0ecSDave Kleikamp goto out; 233ac27a0ecSDave Kleikamp } 2343d0518f4SWei Yongjun offset += ext4_rec_len_from_disk(de->rec_len, 2353d0518f4SWei Yongjun sb->s_blocksize); 236ac27a0ecSDave Kleikamp if (le32_to_cpu(de->inode)) { 237ac27a0ecSDave Kleikamp /* We might block in the next section 238ac27a0ecSDave Kleikamp * if the data destination is 239ac27a0ecSDave Kleikamp * currently swapped out. So, use a 240ac27a0ecSDave Kleikamp * version stamp to detect whether or 241ac27a0ecSDave Kleikamp * not the directory has been modified 242ac27a0ecSDave Kleikamp * during the copy operation. 243ac27a0ecSDave Kleikamp */ 2442b47c361SMathieu Desnoyers u64 version = filp->f_version; 245ac27a0ecSDave Kleikamp 246ac27a0ecSDave Kleikamp error = filldir(dirent, de->name, 247ac27a0ecSDave Kleikamp de->name_len, 248ac27a0ecSDave Kleikamp filp->f_pos, 249ac27a0ecSDave Kleikamp le32_to_cpu(de->inode), 250ac27a0ecSDave Kleikamp get_dtype(sb, de->file_type)); 251ac27a0ecSDave Kleikamp if (error) 252ac27a0ecSDave Kleikamp break; 253ac27a0ecSDave Kleikamp if (version != filp->f_version) 254ac27a0ecSDave Kleikamp goto revalidate; 255ac27a0ecSDave Kleikamp stored++; 256ac27a0ecSDave Kleikamp } 2573d0518f4SWei Yongjun filp->f_pos += ext4_rec_len_from_disk(de->rec_len, 2583d0518f4SWei Yongjun sb->s_blocksize); 259ac27a0ecSDave Kleikamp } 260ac27a0ecSDave Kleikamp offset = 0; 261ac27a0ecSDave Kleikamp brelse(bh); 262ac27a0ecSDave Kleikamp } 263ac27a0ecSDave Kleikamp out: 264ac27a0ecSDave Kleikamp return ret; 265ac27a0ecSDave Kleikamp } 266ac27a0ecSDave Kleikamp 267d1f5273eSFan Yong static inline int is_32bit_api(void) 268d1f5273eSFan Yong { 269d1f5273eSFan Yong #ifdef CONFIG_COMPAT 270d1f5273eSFan Yong return is_compat_task(); 271d1f5273eSFan Yong #else 272d1f5273eSFan Yong return (BITS_PER_LONG == 32); 273d1f5273eSFan Yong #endif 274d1f5273eSFan Yong } 275d1f5273eSFan Yong 276ac27a0ecSDave Kleikamp /* 277ac27a0ecSDave Kleikamp * These functions convert from the major/minor hash to an f_pos 278d1f5273eSFan Yong * value for dx directories 279ac27a0ecSDave Kleikamp * 280d1f5273eSFan Yong * Upper layer (for example NFS) should specify FMODE_32BITHASH or 281d1f5273eSFan Yong * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted 282d1f5273eSFan Yong * directly on both 32-bit and 64-bit nodes, under such case, neither 283d1f5273eSFan Yong * FMODE_32BITHASH nor FMODE_64BITHASH is specified. 284ac27a0ecSDave Kleikamp */ 285d1f5273eSFan Yong static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor) 286d1f5273eSFan Yong { 287d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 288d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 289d1f5273eSFan Yong return major >> 1; 290d1f5273eSFan Yong else 291d1f5273eSFan Yong return ((__u64)(major >> 1) << 32) | (__u64)minor; 292d1f5273eSFan Yong } 293d1f5273eSFan Yong 294d1f5273eSFan Yong static inline __u32 pos2maj_hash(struct file *filp, loff_t pos) 295d1f5273eSFan Yong { 296d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 297d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 298d1f5273eSFan Yong return (pos << 1) & 0xffffffff; 299d1f5273eSFan Yong else 300d1f5273eSFan Yong return ((pos >> 32) << 1) & 0xffffffff; 301d1f5273eSFan Yong } 302d1f5273eSFan Yong 303d1f5273eSFan Yong static inline __u32 pos2min_hash(struct file *filp, loff_t pos) 304d1f5273eSFan Yong { 305d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 306d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 307d1f5273eSFan Yong return 0; 308d1f5273eSFan Yong else 309d1f5273eSFan Yong return pos & 0xffffffff; 310d1f5273eSFan Yong } 311d1f5273eSFan Yong 312d1f5273eSFan Yong /* 313d1f5273eSFan Yong * Return 32- or 64-bit end-of-file for dx directories 314d1f5273eSFan Yong */ 315d1f5273eSFan Yong static inline loff_t ext4_get_htree_eof(struct file *filp) 316d1f5273eSFan Yong { 317d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 318d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 319d1f5273eSFan Yong return EXT4_HTREE_EOF_32BIT; 320d1f5273eSFan Yong else 321d1f5273eSFan Yong return EXT4_HTREE_EOF_64BIT; 322d1f5273eSFan Yong } 323d1f5273eSFan Yong 324d1f5273eSFan Yong 325d1f5273eSFan Yong /* 326ec7268ceSEric Sandeen * ext4_dir_llseek() calls generic_file_llseek_size to handle htree 327ec7268ceSEric Sandeen * directories, where the "offset" is in terms of the filename hash 328ec7268ceSEric Sandeen * value instead of the byte offset. 329d1f5273eSFan Yong * 330ec7268ceSEric Sandeen * Because we may return a 64-bit hash that is well beyond offset limits, 331ec7268ceSEric Sandeen * we need to pass the max hash as the maximum allowable offset in 332ec7268ceSEric Sandeen * the htree directory case. 333ec7268ceSEric Sandeen * 334ec7268ceSEric Sandeen * For non-htree, ext4_llseek already chooses the proper max offset. 335d1f5273eSFan Yong */ 336d1f5273eSFan Yong loff_t ext4_dir_llseek(struct file *file, loff_t offset, int origin) 337d1f5273eSFan Yong { 338d1f5273eSFan Yong struct inode *inode = file->f_mapping->host; 339d1f5273eSFan Yong int dx_dir = is_dx_dir(inode); 340ec7268ceSEric Sandeen loff_t htree_max = ext4_get_htree_eof(file); 341d1f5273eSFan Yong 342ec7268ceSEric Sandeen if (likely(dx_dir)) 343ec7268ceSEric Sandeen return generic_file_llseek_size(file, offset, origin, 344ec7268ceSEric Sandeen htree_max, htree_max); 345d1f5273eSFan Yong else 346ec7268ceSEric Sandeen return ext4_llseek(file, offset, origin); 347d1f5273eSFan Yong } 348ac27a0ecSDave Kleikamp 349ac27a0ecSDave Kleikamp /* 350ac27a0ecSDave Kleikamp * This structure holds the nodes of the red-black tree used to store 351ac27a0ecSDave Kleikamp * the directory entry in hash order. 352ac27a0ecSDave Kleikamp */ 353ac27a0ecSDave Kleikamp struct fname { 354ac27a0ecSDave Kleikamp __u32 hash; 355ac27a0ecSDave Kleikamp __u32 minor_hash; 356ac27a0ecSDave Kleikamp struct rb_node rb_hash; 357ac27a0ecSDave Kleikamp struct fname *next; 358ac27a0ecSDave Kleikamp __u32 inode; 359ac27a0ecSDave Kleikamp __u8 name_len; 360ac27a0ecSDave Kleikamp __u8 file_type; 361ac27a0ecSDave Kleikamp char name[0]; 362ac27a0ecSDave Kleikamp }; 363ac27a0ecSDave Kleikamp 364ac27a0ecSDave Kleikamp /* 365ac27a0ecSDave Kleikamp * This functoin implements a non-recursive way of freeing all of the 366ac27a0ecSDave Kleikamp * nodes in the red-black tree. 367ac27a0ecSDave Kleikamp */ 368ac27a0ecSDave Kleikamp static void free_rb_tree_fname(struct rb_root *root) 369ac27a0ecSDave Kleikamp { 370ac27a0ecSDave Kleikamp struct rb_node *n = root->rb_node; 371ac27a0ecSDave Kleikamp struct rb_node *parent; 372ac27a0ecSDave Kleikamp struct fname *fname; 373ac27a0ecSDave Kleikamp 374ac27a0ecSDave Kleikamp while (n) { 375ac27a0ecSDave Kleikamp /* Do the node's children first */ 37669baee06SShen Feng if (n->rb_left) { 377ac27a0ecSDave Kleikamp n = n->rb_left; 378ac27a0ecSDave Kleikamp continue; 379ac27a0ecSDave Kleikamp } 380ac27a0ecSDave Kleikamp if (n->rb_right) { 381ac27a0ecSDave Kleikamp n = n->rb_right; 382ac27a0ecSDave Kleikamp continue; 383ac27a0ecSDave Kleikamp } 384ac27a0ecSDave Kleikamp /* 385ac27a0ecSDave Kleikamp * The node has no children; free it, and then zero 386ac27a0ecSDave Kleikamp * out parent's link to it. Finally go to the 387ac27a0ecSDave Kleikamp * beginning of the loop and try to free the parent 388ac27a0ecSDave Kleikamp * node. 389ac27a0ecSDave Kleikamp */ 390ac27a0ecSDave Kleikamp parent = rb_parent(n); 391ac27a0ecSDave Kleikamp fname = rb_entry(n, struct fname, rb_hash); 392ac27a0ecSDave Kleikamp while (fname) { 393ac27a0ecSDave Kleikamp struct fname *old = fname; 394ac27a0ecSDave Kleikamp fname = fname->next; 395ac27a0ecSDave Kleikamp kfree(old); 396ac27a0ecSDave Kleikamp } 397ac27a0ecSDave Kleikamp if (!parent) 39864e290ecSVenkatesh Pallipadi *root = RB_ROOT; 399ac27a0ecSDave Kleikamp else if (parent->rb_left == n) 400ac27a0ecSDave Kleikamp parent->rb_left = NULL; 401ac27a0ecSDave Kleikamp else if (parent->rb_right == n) 402ac27a0ecSDave Kleikamp parent->rb_right = NULL; 403ac27a0ecSDave Kleikamp n = parent; 404ac27a0ecSDave Kleikamp } 405ac27a0ecSDave Kleikamp } 406ac27a0ecSDave Kleikamp 407ac27a0ecSDave Kleikamp 408d1f5273eSFan Yong static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp, 409d1f5273eSFan Yong loff_t pos) 410ac27a0ecSDave Kleikamp { 411ac27a0ecSDave Kleikamp struct dir_private_info *p; 412ac27a0ecSDave Kleikamp 41369baee06SShen Feng p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL); 414ac27a0ecSDave Kleikamp if (!p) 415ac27a0ecSDave Kleikamp return NULL; 416d1f5273eSFan Yong p->curr_hash = pos2maj_hash(filp, pos); 417d1f5273eSFan Yong p->curr_minor_hash = pos2min_hash(filp, pos); 418ac27a0ecSDave Kleikamp return p; 419ac27a0ecSDave Kleikamp } 420ac27a0ecSDave Kleikamp 421617ba13bSMingming Cao void ext4_htree_free_dir_info(struct dir_private_info *p) 422ac27a0ecSDave Kleikamp { 423ac27a0ecSDave Kleikamp free_rb_tree_fname(&p->root); 424ac27a0ecSDave Kleikamp kfree(p); 425ac27a0ecSDave Kleikamp } 426ac27a0ecSDave Kleikamp 427ac27a0ecSDave Kleikamp /* 428ac27a0ecSDave Kleikamp * Given a directory entry, enter it into the fname rb tree. 429ac27a0ecSDave Kleikamp */ 430617ba13bSMingming Cao int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, 431ac27a0ecSDave Kleikamp __u32 minor_hash, 432617ba13bSMingming Cao struct ext4_dir_entry_2 *dirent) 433ac27a0ecSDave Kleikamp { 434ac27a0ecSDave Kleikamp struct rb_node **p, *parent = NULL; 435ac27a0ecSDave Kleikamp struct fname *fname, *new_fn; 436ac27a0ecSDave Kleikamp struct dir_private_info *info; 437ac27a0ecSDave Kleikamp int len; 438ac27a0ecSDave Kleikamp 439a271fe85SJoe Perches info = dir_file->private_data; 440ac27a0ecSDave Kleikamp p = &info->root.rb_node; 441ac27a0ecSDave Kleikamp 442ac27a0ecSDave Kleikamp /* Create and allocate the fname structure */ 443ac27a0ecSDave Kleikamp len = sizeof(struct fname) + dirent->name_len + 1; 444ac27a0ecSDave Kleikamp new_fn = kzalloc(len, GFP_KERNEL); 445ac27a0ecSDave Kleikamp if (!new_fn) 446ac27a0ecSDave Kleikamp return -ENOMEM; 447ac27a0ecSDave Kleikamp new_fn->hash = hash; 448ac27a0ecSDave Kleikamp new_fn->minor_hash = minor_hash; 449ac27a0ecSDave Kleikamp new_fn->inode = le32_to_cpu(dirent->inode); 450ac27a0ecSDave Kleikamp new_fn->name_len = dirent->name_len; 451ac27a0ecSDave Kleikamp new_fn->file_type = dirent->file_type; 452ac27a0ecSDave Kleikamp memcpy(new_fn->name, dirent->name, dirent->name_len); 453ac27a0ecSDave Kleikamp new_fn->name[dirent->name_len] = 0; 454ac27a0ecSDave Kleikamp 455ac27a0ecSDave Kleikamp while (*p) { 456ac27a0ecSDave Kleikamp parent = *p; 457ac27a0ecSDave Kleikamp fname = rb_entry(parent, struct fname, rb_hash); 458ac27a0ecSDave Kleikamp 459ac27a0ecSDave Kleikamp /* 460ac27a0ecSDave Kleikamp * If the hash and minor hash match up, then we put 461ac27a0ecSDave Kleikamp * them on a linked list. This rarely happens... 462ac27a0ecSDave Kleikamp */ 463ac27a0ecSDave Kleikamp if ((new_fn->hash == fname->hash) && 464ac27a0ecSDave Kleikamp (new_fn->minor_hash == fname->minor_hash)) { 465ac27a0ecSDave Kleikamp new_fn->next = fname->next; 466ac27a0ecSDave Kleikamp fname->next = new_fn; 467ac27a0ecSDave Kleikamp return 0; 468ac27a0ecSDave Kleikamp } 469ac27a0ecSDave Kleikamp 470ac27a0ecSDave Kleikamp if (new_fn->hash < fname->hash) 471ac27a0ecSDave Kleikamp p = &(*p)->rb_left; 472ac27a0ecSDave Kleikamp else if (new_fn->hash > fname->hash) 473ac27a0ecSDave Kleikamp p = &(*p)->rb_right; 474ac27a0ecSDave Kleikamp else if (new_fn->minor_hash < fname->minor_hash) 475ac27a0ecSDave Kleikamp p = &(*p)->rb_left; 476ac27a0ecSDave Kleikamp else /* if (new_fn->minor_hash > fname->minor_hash) */ 477ac27a0ecSDave Kleikamp p = &(*p)->rb_right; 478ac27a0ecSDave Kleikamp } 479ac27a0ecSDave Kleikamp 480ac27a0ecSDave Kleikamp rb_link_node(&new_fn->rb_hash, parent, p); 481ac27a0ecSDave Kleikamp rb_insert_color(&new_fn->rb_hash, &info->root); 482ac27a0ecSDave Kleikamp return 0; 483ac27a0ecSDave Kleikamp } 484ac27a0ecSDave Kleikamp 485ac27a0ecSDave Kleikamp 486ac27a0ecSDave Kleikamp 487ac27a0ecSDave Kleikamp /* 488617ba13bSMingming Cao * This is a helper function for ext4_dx_readdir. It calls filldir 489ac27a0ecSDave Kleikamp * for all entres on the fname linked list. (Normally there is only 490ac27a0ecSDave Kleikamp * one entry on the linked list, unless there are 62 bit hash collisions.) 491ac27a0ecSDave Kleikamp */ 492ac27a0ecSDave Kleikamp static int call_filldir(struct file *filp, void *dirent, 493ac27a0ecSDave Kleikamp filldir_t filldir, struct fname *fname) 494ac27a0ecSDave Kleikamp { 495ac27a0ecSDave Kleikamp struct dir_private_info *info = filp->private_data; 496ac27a0ecSDave Kleikamp loff_t curr_pos; 4979d549890SJosef "Jeff" Sipek struct inode *inode = filp->f_path.dentry->d_inode; 498ac27a0ecSDave Kleikamp struct super_block *sb; 499ac27a0ecSDave Kleikamp int error; 500ac27a0ecSDave Kleikamp 501ac27a0ecSDave Kleikamp sb = inode->i_sb; 502ac27a0ecSDave Kleikamp 503ac27a0ecSDave Kleikamp if (!fname) { 50492b97816STheodore Ts'o ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: " 50592b97816STheodore Ts'o "called with null fname?!?", __func__, __LINE__, 50692b97816STheodore Ts'o inode->i_ino, current->comm); 507ac27a0ecSDave Kleikamp return 0; 508ac27a0ecSDave Kleikamp } 509d1f5273eSFan Yong curr_pos = hash2pos(filp, fname->hash, fname->minor_hash); 510ac27a0ecSDave Kleikamp while (fname) { 511ac27a0ecSDave Kleikamp error = filldir(dirent, fname->name, 512ac27a0ecSDave Kleikamp fname->name_len, curr_pos, 513ac27a0ecSDave Kleikamp fname->inode, 514ac27a0ecSDave Kleikamp get_dtype(sb, fname->file_type)); 515ac27a0ecSDave Kleikamp if (error) { 516ac27a0ecSDave Kleikamp filp->f_pos = curr_pos; 517d0156417STheodore Ts'o info->extra_fname = fname; 518ac27a0ecSDave Kleikamp return error; 519ac27a0ecSDave Kleikamp } 520ac27a0ecSDave Kleikamp fname = fname->next; 521ac27a0ecSDave Kleikamp } 522ac27a0ecSDave Kleikamp return 0; 523ac27a0ecSDave Kleikamp } 524ac27a0ecSDave Kleikamp 525617ba13bSMingming Cao static int ext4_dx_readdir(struct file *filp, 526ac27a0ecSDave Kleikamp void *dirent, filldir_t filldir) 527ac27a0ecSDave Kleikamp { 528ac27a0ecSDave Kleikamp struct dir_private_info *info = filp->private_data; 5299d549890SJosef "Jeff" Sipek struct inode *inode = filp->f_path.dentry->d_inode; 530ac27a0ecSDave Kleikamp struct fname *fname; 531ac27a0ecSDave Kleikamp int ret; 532ac27a0ecSDave Kleikamp 533ac27a0ecSDave Kleikamp if (!info) { 534d1f5273eSFan Yong info = ext4_htree_create_dir_info(filp, filp->f_pos); 535ac27a0ecSDave Kleikamp if (!info) 536ac27a0ecSDave Kleikamp return -ENOMEM; 537ac27a0ecSDave Kleikamp filp->private_data = info; 538ac27a0ecSDave Kleikamp } 539ac27a0ecSDave Kleikamp 540d1f5273eSFan Yong if (filp->f_pos == ext4_get_htree_eof(filp)) 541ac27a0ecSDave Kleikamp return 0; /* EOF */ 542ac27a0ecSDave Kleikamp 543ac27a0ecSDave Kleikamp /* Some one has messed with f_pos; reset the world */ 544ac27a0ecSDave Kleikamp if (info->last_pos != filp->f_pos) { 545ac27a0ecSDave Kleikamp free_rb_tree_fname(&info->root); 546ac27a0ecSDave Kleikamp info->curr_node = NULL; 547ac27a0ecSDave Kleikamp info->extra_fname = NULL; 548d1f5273eSFan Yong info->curr_hash = pos2maj_hash(filp, filp->f_pos); 549d1f5273eSFan Yong info->curr_minor_hash = pos2min_hash(filp, filp->f_pos); 550ac27a0ecSDave Kleikamp } 551ac27a0ecSDave Kleikamp 552ac27a0ecSDave Kleikamp /* 553ac27a0ecSDave Kleikamp * If there are any leftover names on the hash collision 554ac27a0ecSDave Kleikamp * chain, return them first. 555ac27a0ecSDave Kleikamp */ 556d0156417STheodore Ts'o if (info->extra_fname) { 557d0156417STheodore Ts'o if (call_filldir(filp, dirent, filldir, info->extra_fname)) 558ac27a0ecSDave Kleikamp goto finished; 559d0156417STheodore Ts'o info->extra_fname = NULL; 5603c37fc86STheodore Ts'o goto next_node; 561d0156417STheodore Ts'o } else if (!info->curr_node) 562ac27a0ecSDave Kleikamp info->curr_node = rb_first(&info->root); 563ac27a0ecSDave Kleikamp 564ac27a0ecSDave Kleikamp while (1) { 565ac27a0ecSDave Kleikamp /* 566ac27a0ecSDave Kleikamp * Fill the rbtree if we have no more entries, 567ac27a0ecSDave Kleikamp * or the inode has changed since we last read in the 568ac27a0ecSDave Kleikamp * cached entries. 569ac27a0ecSDave Kleikamp */ 570ac27a0ecSDave Kleikamp if ((!info->curr_node) || 571ac27a0ecSDave Kleikamp (filp->f_version != inode->i_version)) { 572ac27a0ecSDave Kleikamp info->curr_node = NULL; 573ac27a0ecSDave Kleikamp free_rb_tree_fname(&info->root); 574ac27a0ecSDave Kleikamp filp->f_version = inode->i_version; 575617ba13bSMingming Cao ret = ext4_htree_fill_tree(filp, info->curr_hash, 576ac27a0ecSDave Kleikamp info->curr_minor_hash, 577ac27a0ecSDave Kleikamp &info->next_hash); 578ac27a0ecSDave Kleikamp if (ret < 0) 579ac27a0ecSDave Kleikamp return ret; 580ac27a0ecSDave Kleikamp if (ret == 0) { 581d1f5273eSFan Yong filp->f_pos = ext4_get_htree_eof(filp); 582ac27a0ecSDave Kleikamp break; 583ac27a0ecSDave Kleikamp } 584ac27a0ecSDave Kleikamp info->curr_node = rb_first(&info->root); 585ac27a0ecSDave Kleikamp } 586ac27a0ecSDave Kleikamp 587ac27a0ecSDave Kleikamp fname = rb_entry(info->curr_node, struct fname, rb_hash); 588ac27a0ecSDave Kleikamp info->curr_hash = fname->hash; 589ac27a0ecSDave Kleikamp info->curr_minor_hash = fname->minor_hash; 590ac27a0ecSDave Kleikamp if (call_filldir(filp, dirent, filldir, fname)) 591ac27a0ecSDave Kleikamp break; 5923c37fc86STheodore Ts'o next_node: 593ac27a0ecSDave Kleikamp info->curr_node = rb_next(info->curr_node); 5943c37fc86STheodore Ts'o if (info->curr_node) { 5953c37fc86STheodore Ts'o fname = rb_entry(info->curr_node, struct fname, 5963c37fc86STheodore Ts'o rb_hash); 5973c37fc86STheodore Ts'o info->curr_hash = fname->hash; 5983c37fc86STheodore Ts'o info->curr_minor_hash = fname->minor_hash; 5993c37fc86STheodore Ts'o } else { 600ac27a0ecSDave Kleikamp if (info->next_hash == ~0) { 601d1f5273eSFan Yong filp->f_pos = ext4_get_htree_eof(filp); 602ac27a0ecSDave Kleikamp break; 603ac27a0ecSDave Kleikamp } 604ac27a0ecSDave Kleikamp info->curr_hash = info->next_hash; 605ac27a0ecSDave Kleikamp info->curr_minor_hash = 0; 606ac27a0ecSDave Kleikamp } 607ac27a0ecSDave Kleikamp } 608ac27a0ecSDave Kleikamp finished: 609ac27a0ecSDave Kleikamp info->last_pos = filp->f_pos; 610ac27a0ecSDave Kleikamp return 0; 611ac27a0ecSDave Kleikamp } 612ac27a0ecSDave Kleikamp 613617ba13bSMingming Cao static int ext4_release_dir(struct inode *inode, struct file *filp) 614ac27a0ecSDave Kleikamp { 615ac27a0ecSDave Kleikamp if (filp->private_data) 616617ba13bSMingming Cao ext4_htree_free_dir_info(filp->private_data); 617ac27a0ecSDave Kleikamp 618ac27a0ecSDave Kleikamp return 0; 619ac27a0ecSDave Kleikamp } 620d1f5273eSFan Yong 621d1f5273eSFan Yong const struct file_operations ext4_dir_operations = { 622d1f5273eSFan Yong .llseek = ext4_dir_llseek, 623d1f5273eSFan Yong .read = generic_read_dir, 624d1f5273eSFan Yong .readdir = ext4_readdir, 625d1f5273eSFan Yong .unlocked_ioctl = ext4_ioctl, 626d1f5273eSFan Yong #ifdef CONFIG_COMPAT 627d1f5273eSFan Yong .compat_ioctl = ext4_compat_ioctl, 628d1f5273eSFan Yong #endif 629d1f5273eSFan Yong .fsync = ext4_sync_file, 630d1f5273eSFan Yong .release = ext4_release_dir, 631d1f5273eSFan Yong }; 632