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> 25ac27a0ecSDave Kleikamp #include <linux/buffer_head.h> 26ac27a0ecSDave Kleikamp #include <linux/slab.h> 273dcf5451SChristoph Hellwig #include "ext4.h" 2865d165d9STao Ma #include "xattr.h" 29ac27a0ecSDave Kleikamp 30725bebb2SAl Viro static int ext4_dx_readdir(struct file *, struct dir_context *); 31ac27a0ecSDave Kleikamp 32d1f5273eSFan Yong /** 33d1f5273eSFan Yong * Check if the given dir-inode refers to an htree-indexed directory 3470261f56SAnatol Pomozov * (or a directory which could potentially get converted to use htree 35d1f5273eSFan Yong * indexing). 36d1f5273eSFan Yong * 37d1f5273eSFan Yong * Return 1 if it is a dx dir, 0 if not 38d1f5273eSFan Yong */ 39d1f5273eSFan Yong static int is_dx_dir(struct inode *inode) 40d1f5273eSFan Yong { 41d1f5273eSFan Yong struct super_block *sb = inode->i_sb; 42d1f5273eSFan Yong 43e2b911c5SDarrick J. Wong if (ext4_has_feature_dir_index(inode->i_sb) && 44d1f5273eSFan Yong ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) || 458af0f082STao Ma ((inode->i_size >> sb->s_blocksize_bits) == 1) || 468af0f082STao Ma ext4_has_inline_data(inode))) 47d1f5273eSFan Yong return 1; 48d1f5273eSFan Yong 49d1f5273eSFan Yong return 0; 50d1f5273eSFan Yong } 51d1f5273eSFan Yong 52cad3f007STheodore Ts'o /* 53cad3f007STheodore Ts'o * Return 0 if the directory entry is OK, and 1 if there is a problem 54cad3f007STheodore Ts'o * 55cad3f007STheodore Ts'o * Note: this is the opposite of what ext2 and ext3 historically returned... 5665d165d9STao Ma * 5765d165d9STao Ma * bh passed here can be an inode block or a dir data block, depending 5865d165d9STao Ma * on the inode inline data flag. 59cad3f007STheodore Ts'o */ 6060fd4da3STheodore Ts'o int __ext4_check_dir_entry(const char *function, unsigned int line, 61f7c21177STheodore Ts'o struct inode *dir, struct file *filp, 62617ba13bSMingming Cao struct ext4_dir_entry_2 *de, 63226ba972STao Ma struct buffer_head *bh, char *buf, int size, 64498e5f24STheodore Ts'o unsigned int offset) 65ac27a0ecSDave Kleikamp { 66ac27a0ecSDave Kleikamp const char *error_msg = NULL; 673d0518f4SWei Yongjun const int rlen = ext4_rec_len_from_disk(de->rec_len, 683d0518f4SWei Yongjun dir->i_sb->s_blocksize); 69ac27a0ecSDave Kleikamp 70cad3f007STheodore Ts'o if (unlikely(rlen < EXT4_DIR_REC_LEN(1))) 71ac27a0ecSDave Kleikamp error_msg = "rec_len is smaller than minimal"; 72cad3f007STheodore Ts'o else if (unlikely(rlen % 4 != 0)) 73ac27a0ecSDave Kleikamp error_msg = "rec_len % 4 != 0"; 74cad3f007STheodore Ts'o else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len))) 75ac27a0ecSDave Kleikamp error_msg = "rec_len is too small for name_len"; 76226ba972STao Ma else if (unlikely(((char *) de - buf) + rlen > size)) 77226ba972STao Ma error_msg = "directory entry across range"; 78cad3f007STheodore Ts'o else if (unlikely(le32_to_cpu(de->inode) > 79cad3f007STheodore Ts'o le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))) 80ac27a0ecSDave Kleikamp error_msg = "inode out of bounds"; 81cad3f007STheodore Ts'o else 82cad3f007STheodore Ts'o return 0; 83ac27a0ecSDave Kleikamp 84f7c21177STheodore Ts'o if (filp) 854fda4003SDan Carpenter ext4_error_file(filp, function, line, bh->b_blocknr, 86f7c21177STheodore Ts'o "bad entry in directory: %s - offset=%u(%u), " 87f7c21177STheodore Ts'o "inode=%u, rec_len=%d, name_len=%d", 88226ba972STao Ma error_msg, (unsigned) (offset % size), 89f7c21177STheodore Ts'o offset, le32_to_cpu(de->inode), 90ac27a0ecSDave Kleikamp rlen, de->name_len); 91f7c21177STheodore Ts'o else 924fda4003SDan Carpenter ext4_error_inode(dir, function, line, bh->b_blocknr, 93f7c21177STheodore Ts'o "bad entry in directory: %s - offset=%u(%u), " 94f7c21177STheodore Ts'o "inode=%u, rec_len=%d, name_len=%d", 95226ba972STao Ma error_msg, (unsigned) (offset % size), 96f7c21177STheodore Ts'o offset, le32_to_cpu(de->inode), 97f7c21177STheodore Ts'o rlen, de->name_len); 98f7c21177STheodore Ts'o 99cad3f007STheodore Ts'o return 1; 100ac27a0ecSDave Kleikamp } 101ac27a0ecSDave Kleikamp 102725bebb2SAl Viro static int ext4_readdir(struct file *file, struct dir_context *ctx) 103ac27a0ecSDave Kleikamp { 104498e5f24STheodore Ts'o unsigned int offset; 105aa13d5f6SGiedrius Rekasius int i; 106617ba13bSMingming Cao struct ext4_dir_entry_2 *de; 107ac27a0ecSDave Kleikamp int err; 108725bebb2SAl Viro struct inode *inode = file_inode(file); 109d1f5273eSFan Yong struct super_block *sb = inode->i_sb; 11044614711SMichael Halcrow struct buffer_head *bh = NULL; 1119d9f1775SEric Sandeen int dir_has_error = 0; 11244614711SMichael Halcrow struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}; 113ac27a0ecSDave Kleikamp 11428b4c263STheodore Ts'o if (ext4_encrypted_inode(inode)) { 11528b4c263STheodore Ts'o err = ext4_get_encryption_info(inode); 11628b4c263STheodore Ts'o if (err && err != -ENOKEY) 11728b4c263STheodore Ts'o return err; 11828b4c263STheodore Ts'o } 11928b4c263STheodore Ts'o 120d1f5273eSFan Yong if (is_dx_dir(inode)) { 121725bebb2SAl Viro err = ext4_dx_readdir(file, ctx); 122ac27a0ecSDave Kleikamp if (err != ERR_BAD_DX_DIR) { 123725bebb2SAl Viro return err; 124ac27a0ecSDave Kleikamp } 125ac27a0ecSDave Kleikamp /* 126ac27a0ecSDave Kleikamp * We don't set the inode dirty flag since it's not 127ac27a0ecSDave Kleikamp * critical that it get flushed back to the disk. 128ac27a0ecSDave Kleikamp */ 129725bebb2SAl Viro ext4_clear_inode_flag(file_inode(file), 13007a03824STheodore Ts'o EXT4_INODE_INDEX); 131ac27a0ecSDave Kleikamp } 1328af0f082STao Ma 1338af0f082STao Ma if (ext4_has_inline_data(inode)) { 1348af0f082STao Ma int has_inline_data = 1; 13544614711SMichael Halcrow err = ext4_read_inline_dir(file, ctx, 1368af0f082STao Ma &has_inline_data); 1378af0f082STao Ma if (has_inline_data) 13844614711SMichael Halcrow return err; 13944614711SMichael Halcrow } 14044614711SMichael Halcrow 141b7236e21STheodore Ts'o if (ext4_encrypted_inode(inode)) { 142b7236e21STheodore Ts'o err = ext4_fname_crypto_alloc_buffer(inode, EXT4_NAME_LEN, 143b7236e21STheodore Ts'o &fname_crypto_str); 144b7236e21STheodore Ts'o if (err < 0) 145b7236e21STheodore Ts'o return err; 1468af0f082STao Ma } 1478af0f082STao Ma 148725bebb2SAl Viro offset = ctx->pos & (sb->s_blocksize - 1); 149ac27a0ecSDave Kleikamp 150725bebb2SAl Viro while (ctx->pos < inode->i_size) { 1512ed88685STheodore Ts'o struct ext4_map_blocks map; 152ac27a0ecSDave Kleikamp 153725bebb2SAl Viro map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb); 1542ed88685STheodore Ts'o map.m_len = 1; 1552ed88685STheodore Ts'o err = ext4_map_blocks(NULL, inode, &map, 0); 156ac27a0ecSDave Kleikamp if (err > 0) { 1572ed88685STheodore Ts'o pgoff_t index = map.m_pblk >> 158dc7868fcSFengguang Wu (PAGE_CACHE_SHIFT - inode->i_blkbits); 159725bebb2SAl Viro if (!ra_has_index(&file->f_ra, index)) 160cf914a7dSRusty Russell page_cache_sync_readahead( 161dc7868fcSFengguang Wu sb->s_bdev->bd_inode->i_mapping, 162725bebb2SAl Viro &file->f_ra, file, 163cf914a7dSRusty Russell index, 1); 164725bebb2SAl Viro file->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT; 1651c215028STheodore Ts'o bh = ext4_bread(NULL, inode, map.m_lblk, 0); 166c906f38eSKirill Tkhai if (IS_ERR(bh)) { 167c906f38eSKirill Tkhai err = PTR_ERR(bh); 168c906f38eSKirill Tkhai bh = NULL; 169c906f38eSKirill Tkhai goto errout; 170c906f38eSKirill Tkhai } 171ac27a0ecSDave Kleikamp } 172ac27a0ecSDave Kleikamp 173ac27a0ecSDave Kleikamp if (!bh) { 1749d9f1775SEric Sandeen if (!dir_has_error) { 175725bebb2SAl Viro EXT4_ERROR_FILE(file, 0, 176f7c21177STheodore Ts'o "directory contains a " 177f7c21177STheodore Ts'o "hole at offset %llu", 178725bebb2SAl Viro (unsigned long long) ctx->pos); 1799d9f1775SEric Sandeen dir_has_error = 1; 1809d9f1775SEric Sandeen } 181e6c40211SEric Sandeen /* corrupt size? Maybe no more blocks to read */ 182725bebb2SAl Viro if (ctx->pos > inode->i_blocks << 9) 183e6c40211SEric Sandeen break; 184725bebb2SAl Viro ctx->pos += sb->s_blocksize - offset; 185ac27a0ecSDave Kleikamp continue; 186ac27a0ecSDave Kleikamp } 187ac27a0ecSDave Kleikamp 188b0336e8dSDarrick J. Wong /* Check the checksum */ 189b0336e8dSDarrick J. Wong if (!buffer_verified(bh) && 190b0336e8dSDarrick J. Wong !ext4_dirent_csum_verify(inode, 191b0336e8dSDarrick J. Wong (struct ext4_dir_entry *)bh->b_data)) { 192725bebb2SAl Viro EXT4_ERROR_FILE(file, 0, "directory fails checksum " 193b0336e8dSDarrick J. Wong "at offset %llu", 194725bebb2SAl Viro (unsigned long long)ctx->pos); 195725bebb2SAl Viro ctx->pos += sb->s_blocksize - offset; 196d5ac7773SGuo Chao brelse(bh); 19744614711SMichael Halcrow bh = NULL; 198b0336e8dSDarrick J. Wong continue; 199b0336e8dSDarrick J. Wong } 200b0336e8dSDarrick J. Wong set_buffer_verified(bh); 201b0336e8dSDarrick J. Wong 202ac27a0ecSDave Kleikamp /* If the dir block has changed since the last call to 203ac27a0ecSDave Kleikamp * readdir(2), then we might be pointing to an invalid 204ac27a0ecSDave Kleikamp * dirent right now. Scan from the start of the block 205ac27a0ecSDave Kleikamp * to make sure. */ 206725bebb2SAl Viro if (file->f_version != inode->i_version) { 207ac27a0ecSDave Kleikamp for (i = 0; i < sb->s_blocksize && i < offset; ) { 208617ba13bSMingming Cao de = (struct ext4_dir_entry_2 *) 209ac27a0ecSDave Kleikamp (bh->b_data + i); 210ac27a0ecSDave Kleikamp /* It's too expensive to do a full 211ac27a0ecSDave Kleikamp * dirent test each time round this 212ac27a0ecSDave Kleikamp * loop, but we do have to test at 213ac27a0ecSDave Kleikamp * least that it is non-zero. A 214ac27a0ecSDave Kleikamp * failure will be detected in the 215ac27a0ecSDave Kleikamp * dirent test below. */ 2163d0518f4SWei Yongjun if (ext4_rec_len_from_disk(de->rec_len, 2173d0518f4SWei Yongjun sb->s_blocksize) < EXT4_DIR_REC_LEN(1)) 218ac27a0ecSDave Kleikamp break; 2193d0518f4SWei Yongjun i += ext4_rec_len_from_disk(de->rec_len, 2203d0518f4SWei Yongjun sb->s_blocksize); 221ac27a0ecSDave Kleikamp } 222ac27a0ecSDave Kleikamp offset = i; 223725bebb2SAl Viro ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) 224ac27a0ecSDave Kleikamp | offset; 225725bebb2SAl Viro file->f_version = inode->i_version; 226ac27a0ecSDave Kleikamp } 227ac27a0ecSDave Kleikamp 228725bebb2SAl Viro while (ctx->pos < inode->i_size 229ac27a0ecSDave Kleikamp && offset < sb->s_blocksize) { 230617ba13bSMingming Cao de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); 231725bebb2SAl Viro if (ext4_check_dir_entry(inode, file, de, bh, 232226ba972STao Ma bh->b_data, bh->b_size, 233226ba972STao Ma offset)) { 23463f57933SAndrew Morton /* 235725bebb2SAl Viro * On error, skip to the next block 23663f57933SAndrew Morton */ 237725bebb2SAl Viro ctx->pos = (ctx->pos | 238ac27a0ecSDave Kleikamp (sb->s_blocksize - 1)) + 1; 239725bebb2SAl Viro break; 240ac27a0ecSDave Kleikamp } 2413d0518f4SWei Yongjun offset += ext4_rec_len_from_disk(de->rec_len, 2423d0518f4SWei Yongjun sb->s_blocksize); 243ac27a0ecSDave Kleikamp if (le32_to_cpu(de->inode)) { 244b7236e21STheodore Ts'o if (!ext4_encrypted_inode(inode)) { 245725bebb2SAl Viro if (!dir_emit(ctx, de->name, 246ac27a0ecSDave Kleikamp de->name_len, 247ac27a0ecSDave Kleikamp le32_to_cpu(de->inode), 24844614711SMichael Halcrow get_dtype(sb, de->file_type))) 24944614711SMichael Halcrow goto done; 25044614711SMichael Halcrow } else { 251d2299590STheodore Ts'o int save_len = fname_crypto_str.len; 252d2299590STheodore Ts'o 25344614711SMichael Halcrow /* Directory is encrypted */ 254b7236e21STheodore Ts'o err = ext4_fname_disk_to_usr(inode, 2555de0b4d0STheodore Ts'o NULL, de, &fname_crypto_str); 256d2299590STheodore Ts'o fname_crypto_str.len = save_len; 25744614711SMichael Halcrow if (err < 0) 25844614711SMichael Halcrow goto errout; 25944614711SMichael Halcrow if (!dir_emit(ctx, 26044614711SMichael Halcrow fname_crypto_str.name, err, 26144614711SMichael Halcrow le32_to_cpu(de->inode), 26244614711SMichael Halcrow get_dtype(sb, de->file_type))) 26344614711SMichael Halcrow goto done; 264ac27a0ecSDave Kleikamp } 265725bebb2SAl Viro } 266725bebb2SAl Viro ctx->pos += ext4_rec_len_from_disk(de->rec_len, 2673d0518f4SWei Yongjun sb->s_blocksize); 268ac27a0ecSDave Kleikamp } 26944614711SMichael Halcrow if ((ctx->pos < inode->i_size) && !dir_relax(inode)) 27044614711SMichael Halcrow goto done; 271ac27a0ecSDave Kleikamp brelse(bh); 27244614711SMichael Halcrow bh = NULL; 27344614711SMichael Halcrow offset = 0; 274ac27a0ecSDave Kleikamp } 27544614711SMichael Halcrow done: 27644614711SMichael Halcrow err = 0; 27744614711SMichael Halcrow errout: 27844614711SMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 27944614711SMichael Halcrow ext4_fname_crypto_free_buffer(&fname_crypto_str); 28044614711SMichael Halcrow #endif 28144614711SMichael Halcrow brelse(bh); 28244614711SMichael Halcrow return err; 283ac27a0ecSDave Kleikamp } 284ac27a0ecSDave Kleikamp 285d1f5273eSFan Yong static inline int is_32bit_api(void) 286d1f5273eSFan Yong { 287d1f5273eSFan Yong #ifdef CONFIG_COMPAT 288d1f5273eSFan Yong return is_compat_task(); 289d1f5273eSFan Yong #else 290d1f5273eSFan Yong return (BITS_PER_LONG == 32); 291d1f5273eSFan Yong #endif 292d1f5273eSFan Yong } 293d1f5273eSFan Yong 294ac27a0ecSDave Kleikamp /* 295ac27a0ecSDave Kleikamp * These functions convert from the major/minor hash to an f_pos 296d1f5273eSFan Yong * value for dx directories 297ac27a0ecSDave Kleikamp * 298d1f5273eSFan Yong * Upper layer (for example NFS) should specify FMODE_32BITHASH or 299d1f5273eSFan Yong * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted 300d1f5273eSFan Yong * directly on both 32-bit and 64-bit nodes, under such case, neither 301d1f5273eSFan Yong * FMODE_32BITHASH nor FMODE_64BITHASH is specified. 302ac27a0ecSDave Kleikamp */ 303d1f5273eSFan Yong static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor) 304d1f5273eSFan Yong { 305d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 306d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 307d1f5273eSFan Yong return major >> 1; 308d1f5273eSFan Yong else 309d1f5273eSFan Yong return ((__u64)(major >> 1) << 32) | (__u64)minor; 310d1f5273eSFan Yong } 311d1f5273eSFan Yong 312d1f5273eSFan Yong static inline __u32 pos2maj_hash(struct file *filp, loff_t pos) 313d1f5273eSFan Yong { 314d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 315d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 316d1f5273eSFan Yong return (pos << 1) & 0xffffffff; 317d1f5273eSFan Yong else 318d1f5273eSFan Yong return ((pos >> 32) << 1) & 0xffffffff; 319d1f5273eSFan Yong } 320d1f5273eSFan Yong 321d1f5273eSFan Yong static inline __u32 pos2min_hash(struct file *filp, loff_t pos) 322d1f5273eSFan Yong { 323d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 324d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 325d1f5273eSFan Yong return 0; 326d1f5273eSFan Yong else 327d1f5273eSFan Yong return pos & 0xffffffff; 328d1f5273eSFan Yong } 329d1f5273eSFan Yong 330d1f5273eSFan Yong /* 331d1f5273eSFan Yong * Return 32- or 64-bit end-of-file for dx directories 332d1f5273eSFan Yong */ 333d1f5273eSFan Yong static inline loff_t ext4_get_htree_eof(struct file *filp) 334d1f5273eSFan Yong { 335d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 336d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 337d1f5273eSFan Yong return EXT4_HTREE_EOF_32BIT; 338d1f5273eSFan Yong else 339d1f5273eSFan Yong return EXT4_HTREE_EOF_64BIT; 340d1f5273eSFan Yong } 341d1f5273eSFan Yong 342d1f5273eSFan Yong 343d1f5273eSFan Yong /* 344ec7268ceSEric Sandeen * ext4_dir_llseek() calls generic_file_llseek_size to handle htree 345ec7268ceSEric Sandeen * directories, where the "offset" is in terms of the filename hash 346ec7268ceSEric Sandeen * value instead of the byte offset. 347d1f5273eSFan Yong * 348ec7268ceSEric Sandeen * Because we may return a 64-bit hash that is well beyond offset limits, 349ec7268ceSEric Sandeen * we need to pass the max hash as the maximum allowable offset in 350ec7268ceSEric Sandeen * the htree directory case. 351ec7268ceSEric Sandeen * 352ec7268ceSEric Sandeen * For non-htree, ext4_llseek already chooses the proper max offset. 353d1f5273eSFan Yong */ 354d4e43954SZheng Liu static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence) 355d1f5273eSFan Yong { 356d1f5273eSFan Yong struct inode *inode = file->f_mapping->host; 357d1f5273eSFan Yong int dx_dir = is_dx_dir(inode); 358ec7268ceSEric Sandeen loff_t htree_max = ext4_get_htree_eof(file); 359d1f5273eSFan Yong 360ec7268ceSEric Sandeen if (likely(dx_dir)) 361965c8e59SAndrew Morton return generic_file_llseek_size(file, offset, whence, 362ec7268ceSEric Sandeen htree_max, htree_max); 363d1f5273eSFan Yong else 364965c8e59SAndrew Morton return ext4_llseek(file, offset, whence); 365d1f5273eSFan Yong } 366ac27a0ecSDave Kleikamp 367ac27a0ecSDave Kleikamp /* 368ac27a0ecSDave Kleikamp * This structure holds the nodes of the red-black tree used to store 369ac27a0ecSDave Kleikamp * the directory entry in hash order. 370ac27a0ecSDave Kleikamp */ 371ac27a0ecSDave Kleikamp struct fname { 372ac27a0ecSDave Kleikamp __u32 hash; 373ac27a0ecSDave Kleikamp __u32 minor_hash; 374ac27a0ecSDave Kleikamp struct rb_node rb_hash; 375ac27a0ecSDave Kleikamp struct fname *next; 376ac27a0ecSDave Kleikamp __u32 inode; 377ac27a0ecSDave Kleikamp __u8 name_len; 378ac27a0ecSDave Kleikamp __u8 file_type; 379ac27a0ecSDave Kleikamp char name[0]; 380ac27a0ecSDave Kleikamp }; 381ac27a0ecSDave Kleikamp 382ac27a0ecSDave Kleikamp /* 383ac27a0ecSDave Kleikamp * This functoin implements a non-recursive way of freeing all of the 384ac27a0ecSDave Kleikamp * nodes in the red-black tree. 385ac27a0ecSDave Kleikamp */ 386ac27a0ecSDave Kleikamp static void free_rb_tree_fname(struct rb_root *root) 387ac27a0ecSDave Kleikamp { 388d1866bd0SCody P Schafer struct fname *fname, *next; 389ac27a0ecSDave Kleikamp 390d1866bd0SCody P Schafer rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash) 391ac27a0ecSDave Kleikamp while (fname) { 392ac27a0ecSDave Kleikamp struct fname *old = fname; 393ac27a0ecSDave Kleikamp fname = fname->next; 394ac27a0ecSDave Kleikamp kfree(old); 395ac27a0ecSDave Kleikamp } 396d1866bd0SCody P Schafer 39764e290ecSVenkatesh Pallipadi *root = RB_ROOT; 398ac27a0ecSDave Kleikamp } 399ac27a0ecSDave Kleikamp 400ac27a0ecSDave Kleikamp 401d1f5273eSFan Yong static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp, 402d1f5273eSFan Yong loff_t pos) 403ac27a0ecSDave Kleikamp { 404ac27a0ecSDave Kleikamp struct dir_private_info *p; 405ac27a0ecSDave Kleikamp 40669baee06SShen Feng p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL); 407ac27a0ecSDave Kleikamp if (!p) 408ac27a0ecSDave Kleikamp return NULL; 409d1f5273eSFan Yong p->curr_hash = pos2maj_hash(filp, pos); 410d1f5273eSFan Yong p->curr_minor_hash = pos2min_hash(filp, pos); 411ac27a0ecSDave Kleikamp return p; 412ac27a0ecSDave Kleikamp } 413ac27a0ecSDave Kleikamp 414617ba13bSMingming Cao void ext4_htree_free_dir_info(struct dir_private_info *p) 415ac27a0ecSDave Kleikamp { 416ac27a0ecSDave Kleikamp free_rb_tree_fname(&p->root); 417ac27a0ecSDave Kleikamp kfree(p); 418ac27a0ecSDave Kleikamp } 419ac27a0ecSDave Kleikamp 420ac27a0ecSDave Kleikamp /* 421ac27a0ecSDave Kleikamp * Given a directory entry, enter it into the fname rb tree. 4222f61830aSTheodore Ts'o * 4232f61830aSTheodore Ts'o * When filename encryption is enabled, the dirent will hold the 4242f61830aSTheodore Ts'o * encrypted filename, while the htree will hold decrypted filename. 4252f61830aSTheodore Ts'o * The decrypted filename is passed in via ent_name. parameter. 426ac27a0ecSDave Kleikamp */ 427617ba13bSMingming Cao int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, 428ac27a0ecSDave Kleikamp __u32 minor_hash, 4292f61830aSTheodore Ts'o struct ext4_dir_entry_2 *dirent, 4302f61830aSTheodore Ts'o struct ext4_str *ent_name) 431ac27a0ecSDave Kleikamp { 432ac27a0ecSDave Kleikamp struct rb_node **p, *parent = NULL; 433ac27a0ecSDave Kleikamp struct fname *fname, *new_fn; 434ac27a0ecSDave Kleikamp struct dir_private_info *info; 435ac27a0ecSDave Kleikamp int len; 436ac27a0ecSDave Kleikamp 437a271fe85SJoe Perches info = dir_file->private_data; 438ac27a0ecSDave Kleikamp p = &info->root.rb_node; 439ac27a0ecSDave Kleikamp 440ac27a0ecSDave Kleikamp /* Create and allocate the fname structure */ 4412f61830aSTheodore Ts'o len = sizeof(struct fname) + ent_name->len + 1; 442ac27a0ecSDave Kleikamp new_fn = kzalloc(len, GFP_KERNEL); 443ac27a0ecSDave Kleikamp if (!new_fn) 444ac27a0ecSDave Kleikamp return -ENOMEM; 445ac27a0ecSDave Kleikamp new_fn->hash = hash; 446ac27a0ecSDave Kleikamp new_fn->minor_hash = minor_hash; 447ac27a0ecSDave Kleikamp new_fn->inode = le32_to_cpu(dirent->inode); 4482f61830aSTheodore Ts'o new_fn->name_len = ent_name->len; 449ac27a0ecSDave Kleikamp new_fn->file_type = dirent->file_type; 4502f61830aSTheodore Ts'o memcpy(new_fn->name, ent_name->name, ent_name->len); 4512f61830aSTheodore Ts'o new_fn->name[ent_name->len] = 0; 452ac27a0ecSDave Kleikamp 453ac27a0ecSDave Kleikamp while (*p) { 454ac27a0ecSDave Kleikamp parent = *p; 455ac27a0ecSDave Kleikamp fname = rb_entry(parent, struct fname, rb_hash); 456ac27a0ecSDave Kleikamp 457ac27a0ecSDave Kleikamp /* 458ac27a0ecSDave Kleikamp * If the hash and minor hash match up, then we put 459ac27a0ecSDave Kleikamp * them on a linked list. This rarely happens... 460ac27a0ecSDave Kleikamp */ 461ac27a0ecSDave Kleikamp if ((new_fn->hash == fname->hash) && 462ac27a0ecSDave Kleikamp (new_fn->minor_hash == fname->minor_hash)) { 463ac27a0ecSDave Kleikamp new_fn->next = fname->next; 464ac27a0ecSDave Kleikamp fname->next = new_fn; 465ac27a0ecSDave Kleikamp return 0; 466ac27a0ecSDave Kleikamp } 467ac27a0ecSDave Kleikamp 468ac27a0ecSDave Kleikamp if (new_fn->hash < fname->hash) 469ac27a0ecSDave Kleikamp p = &(*p)->rb_left; 470ac27a0ecSDave Kleikamp else if (new_fn->hash > fname->hash) 471ac27a0ecSDave Kleikamp p = &(*p)->rb_right; 472ac27a0ecSDave Kleikamp else if (new_fn->minor_hash < fname->minor_hash) 473ac27a0ecSDave Kleikamp p = &(*p)->rb_left; 474ac27a0ecSDave Kleikamp else /* if (new_fn->minor_hash > fname->minor_hash) */ 475ac27a0ecSDave Kleikamp p = &(*p)->rb_right; 476ac27a0ecSDave Kleikamp } 477ac27a0ecSDave Kleikamp 478ac27a0ecSDave Kleikamp rb_link_node(&new_fn->rb_hash, parent, p); 479ac27a0ecSDave Kleikamp rb_insert_color(&new_fn->rb_hash, &info->root); 480ac27a0ecSDave Kleikamp return 0; 481ac27a0ecSDave Kleikamp } 482ac27a0ecSDave Kleikamp 483ac27a0ecSDave Kleikamp 484ac27a0ecSDave Kleikamp 485ac27a0ecSDave Kleikamp /* 486617ba13bSMingming Cao * This is a helper function for ext4_dx_readdir. It calls filldir 487ac27a0ecSDave Kleikamp * for all entres on the fname linked list. (Normally there is only 488ac27a0ecSDave Kleikamp * one entry on the linked list, unless there are 62 bit hash collisions.) 489ac27a0ecSDave Kleikamp */ 490725bebb2SAl Viro static int call_filldir(struct file *file, struct dir_context *ctx, 491725bebb2SAl Viro struct fname *fname) 492ac27a0ecSDave Kleikamp { 493725bebb2SAl Viro struct dir_private_info *info = file->private_data; 494725bebb2SAl Viro struct inode *inode = file_inode(file); 495725bebb2SAl Viro struct super_block *sb = inode->i_sb; 496ac27a0ecSDave Kleikamp 497ac27a0ecSDave Kleikamp if (!fname) { 49892b97816STheodore Ts'o ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: " 49992b97816STheodore Ts'o "called with null fname?!?", __func__, __LINE__, 50092b97816STheodore Ts'o inode->i_ino, current->comm); 501ac27a0ecSDave Kleikamp return 0; 502ac27a0ecSDave Kleikamp } 503725bebb2SAl Viro ctx->pos = hash2pos(file, fname->hash, fname->minor_hash); 504ac27a0ecSDave Kleikamp while (fname) { 505725bebb2SAl Viro if (!dir_emit(ctx, fname->name, 506725bebb2SAl Viro fname->name_len, 507ac27a0ecSDave Kleikamp fname->inode, 508725bebb2SAl Viro get_dtype(sb, fname->file_type))) { 509d0156417STheodore Ts'o info->extra_fname = fname; 510725bebb2SAl Viro return 1; 511ac27a0ecSDave Kleikamp } 512ac27a0ecSDave Kleikamp fname = fname->next; 513ac27a0ecSDave Kleikamp } 514ac27a0ecSDave Kleikamp return 0; 515ac27a0ecSDave Kleikamp } 516ac27a0ecSDave Kleikamp 517725bebb2SAl Viro static int ext4_dx_readdir(struct file *file, struct dir_context *ctx) 518ac27a0ecSDave Kleikamp { 519725bebb2SAl Viro struct dir_private_info *info = file->private_data; 520725bebb2SAl Viro struct inode *inode = file_inode(file); 521ac27a0ecSDave Kleikamp struct fname *fname; 522ac27a0ecSDave Kleikamp int ret; 523ac27a0ecSDave Kleikamp 524ac27a0ecSDave Kleikamp if (!info) { 525725bebb2SAl Viro info = ext4_htree_create_dir_info(file, ctx->pos); 526ac27a0ecSDave Kleikamp if (!info) 527ac27a0ecSDave Kleikamp return -ENOMEM; 528725bebb2SAl Viro file->private_data = info; 529ac27a0ecSDave Kleikamp } 530ac27a0ecSDave Kleikamp 531725bebb2SAl Viro if (ctx->pos == ext4_get_htree_eof(file)) 532ac27a0ecSDave Kleikamp return 0; /* EOF */ 533ac27a0ecSDave Kleikamp 534ac27a0ecSDave Kleikamp /* Some one has messed with f_pos; reset the world */ 535725bebb2SAl Viro if (info->last_pos != ctx->pos) { 536ac27a0ecSDave Kleikamp free_rb_tree_fname(&info->root); 537ac27a0ecSDave Kleikamp info->curr_node = NULL; 538ac27a0ecSDave Kleikamp info->extra_fname = NULL; 539725bebb2SAl Viro info->curr_hash = pos2maj_hash(file, ctx->pos); 540725bebb2SAl Viro info->curr_minor_hash = pos2min_hash(file, ctx->pos); 541ac27a0ecSDave Kleikamp } 542ac27a0ecSDave Kleikamp 543ac27a0ecSDave Kleikamp /* 544ac27a0ecSDave Kleikamp * If there are any leftover names on the hash collision 545ac27a0ecSDave Kleikamp * chain, return them first. 546ac27a0ecSDave Kleikamp */ 547d0156417STheodore Ts'o if (info->extra_fname) { 548725bebb2SAl Viro if (call_filldir(file, ctx, info->extra_fname)) 549ac27a0ecSDave Kleikamp goto finished; 550d0156417STheodore Ts'o info->extra_fname = NULL; 5513c37fc86STheodore Ts'o goto next_node; 552d0156417STheodore Ts'o } else if (!info->curr_node) 553ac27a0ecSDave Kleikamp info->curr_node = rb_first(&info->root); 554ac27a0ecSDave Kleikamp 555ac27a0ecSDave Kleikamp while (1) { 556ac27a0ecSDave Kleikamp /* 557ac27a0ecSDave Kleikamp * Fill the rbtree if we have no more entries, 558ac27a0ecSDave Kleikamp * or the inode has changed since we last read in the 559ac27a0ecSDave Kleikamp * cached entries. 560ac27a0ecSDave Kleikamp */ 561ac27a0ecSDave Kleikamp if ((!info->curr_node) || 562725bebb2SAl Viro (file->f_version != inode->i_version)) { 563ac27a0ecSDave Kleikamp info->curr_node = NULL; 564ac27a0ecSDave Kleikamp free_rb_tree_fname(&info->root); 565725bebb2SAl Viro file->f_version = inode->i_version; 566725bebb2SAl Viro ret = ext4_htree_fill_tree(file, info->curr_hash, 567ac27a0ecSDave Kleikamp info->curr_minor_hash, 568ac27a0ecSDave Kleikamp &info->next_hash); 569ac27a0ecSDave Kleikamp if (ret < 0) 570ac27a0ecSDave Kleikamp return ret; 571ac27a0ecSDave Kleikamp if (ret == 0) { 572725bebb2SAl Viro ctx->pos = ext4_get_htree_eof(file); 573ac27a0ecSDave Kleikamp break; 574ac27a0ecSDave Kleikamp } 575ac27a0ecSDave Kleikamp info->curr_node = rb_first(&info->root); 576ac27a0ecSDave Kleikamp } 577ac27a0ecSDave Kleikamp 578ac27a0ecSDave Kleikamp fname = rb_entry(info->curr_node, struct fname, rb_hash); 579ac27a0ecSDave Kleikamp info->curr_hash = fname->hash; 580ac27a0ecSDave Kleikamp info->curr_minor_hash = fname->minor_hash; 581725bebb2SAl Viro if (call_filldir(file, ctx, fname)) 582ac27a0ecSDave Kleikamp break; 5833c37fc86STheodore Ts'o next_node: 584ac27a0ecSDave Kleikamp info->curr_node = rb_next(info->curr_node); 5853c37fc86STheodore Ts'o if (info->curr_node) { 5863c37fc86STheodore Ts'o fname = rb_entry(info->curr_node, struct fname, 5873c37fc86STheodore Ts'o rb_hash); 5883c37fc86STheodore Ts'o info->curr_hash = fname->hash; 5893c37fc86STheodore Ts'o info->curr_minor_hash = fname->minor_hash; 5903c37fc86STheodore Ts'o } else { 591ac27a0ecSDave Kleikamp if (info->next_hash == ~0) { 592725bebb2SAl Viro ctx->pos = ext4_get_htree_eof(file); 593ac27a0ecSDave Kleikamp break; 594ac27a0ecSDave Kleikamp } 595ac27a0ecSDave Kleikamp info->curr_hash = info->next_hash; 596ac27a0ecSDave Kleikamp info->curr_minor_hash = 0; 597ac27a0ecSDave Kleikamp } 598ac27a0ecSDave Kleikamp } 599ac27a0ecSDave Kleikamp finished: 600725bebb2SAl Viro info->last_pos = ctx->pos; 601ac27a0ecSDave Kleikamp return 0; 602ac27a0ecSDave Kleikamp } 603ac27a0ecSDave Kleikamp 6046bc445e0STheodore Ts'o static int ext4_dir_open(struct inode * inode, struct file * filp) 6056bc445e0STheodore Ts'o { 6066bc445e0STheodore Ts'o if (ext4_encrypted_inode(inode)) 6076bc445e0STheodore Ts'o return ext4_get_encryption_info(inode) ? -EACCES : 0; 6086bc445e0STheodore Ts'o return 0; 6096bc445e0STheodore Ts'o } 6106bc445e0STheodore Ts'o 611617ba13bSMingming Cao static int ext4_release_dir(struct inode *inode, struct file *filp) 612ac27a0ecSDave Kleikamp { 613ac27a0ecSDave Kleikamp if (filp->private_data) 614617ba13bSMingming Cao ext4_htree_free_dir_info(filp->private_data); 615ac27a0ecSDave Kleikamp 616ac27a0ecSDave Kleikamp return 0; 617ac27a0ecSDave Kleikamp } 618d1f5273eSFan Yong 61940b163f1SDarrick J. Wong int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf, 62040b163f1SDarrick J. Wong int buf_size) 62140b163f1SDarrick J. Wong { 62240b163f1SDarrick J. Wong struct ext4_dir_entry_2 *de; 62340b163f1SDarrick J. Wong int nlen, rlen; 62440b163f1SDarrick J. Wong unsigned int offset = 0; 62540b163f1SDarrick J. Wong char *top; 62640b163f1SDarrick J. Wong 62740b163f1SDarrick J. Wong de = (struct ext4_dir_entry_2 *)buf; 62840b163f1SDarrick J. Wong top = buf + buf_size; 62940b163f1SDarrick J. Wong while ((char *) de < top) { 63040b163f1SDarrick J. Wong if (ext4_check_dir_entry(dir, NULL, de, bh, 63140b163f1SDarrick J. Wong buf, buf_size, offset)) 6326a797d27SDarrick J. Wong return -EFSCORRUPTED; 63340b163f1SDarrick J. Wong nlen = EXT4_DIR_REC_LEN(de->name_len); 63440b163f1SDarrick J. Wong rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 63540b163f1SDarrick J. Wong de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 63640b163f1SDarrick J. Wong offset += rlen; 63740b163f1SDarrick J. Wong } 63840b163f1SDarrick J. Wong if ((char *) de > top) 6396a797d27SDarrick J. Wong return -EFSCORRUPTED; 64040b163f1SDarrick J. Wong 64140b163f1SDarrick J. Wong return 0; 64240b163f1SDarrick J. Wong } 64340b163f1SDarrick J. Wong 644d1f5273eSFan Yong const struct file_operations ext4_dir_operations = { 645d1f5273eSFan Yong .llseek = ext4_dir_llseek, 646d1f5273eSFan Yong .read = generic_read_dir, 647725bebb2SAl Viro .iterate = ext4_readdir, 648d1f5273eSFan Yong .unlocked_ioctl = ext4_ioctl, 649d1f5273eSFan Yong #ifdef CONFIG_COMPAT 650d1f5273eSFan Yong .compat_ioctl = ext4_compat_ioctl, 651d1f5273eSFan Yong #endif 652d1f5273eSFan Yong .fsync = ext4_sync_file, 6536bc445e0STheodore Ts'o .open = ext4_dir_open, 654d1f5273eSFan Yong .release = ext4_release_dir, 655d1f5273eSFan Yong }; 656