1b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0 2ac27a0ecSDave Kleikamp /* 3617ba13bSMingming Cao * linux/fs/ext4/dir.c 4ac27a0ecSDave Kleikamp * 5ac27a0ecSDave Kleikamp * Copyright (C) 1992, 1993, 1994, 1995 6ac27a0ecSDave Kleikamp * Remy Card (card@masi.ibp.fr) 7ac27a0ecSDave Kleikamp * Laboratoire MASI - Institut Blaise Pascal 8ac27a0ecSDave Kleikamp * Universite Pierre et Marie Curie (Paris VI) 9ac27a0ecSDave Kleikamp * 10ac27a0ecSDave Kleikamp * from 11ac27a0ecSDave Kleikamp * 12ac27a0ecSDave Kleikamp * linux/fs/minix/dir.c 13ac27a0ecSDave Kleikamp * 14ac27a0ecSDave Kleikamp * Copyright (C) 1991, 1992 Linus Torvalds 15ac27a0ecSDave Kleikamp * 16617ba13bSMingming Cao * ext4 directory handling functions 17ac27a0ecSDave Kleikamp * 18ac27a0ecSDave Kleikamp * Big-endian to little-endian byte-swapping/bitmaps by 19ac27a0ecSDave Kleikamp * David S. Miller (davem@caip.rutgers.edu), 1995 20ac27a0ecSDave Kleikamp * 21ac27a0ecSDave Kleikamp * Hash Tree Directory indexing (c) 2001 Daniel Phillips 22ac27a0ecSDave Kleikamp * 23ac27a0ecSDave Kleikamp */ 24ac27a0ecSDave Kleikamp 25ac27a0ecSDave Kleikamp #include <linux/fs.h> 26ac27a0ecSDave Kleikamp #include <linux/buffer_head.h> 27ac27a0ecSDave Kleikamp #include <linux/slab.h> 28ee73f9a5SJeff Layton #include <linux/iversion.h> 29b886ee3eSGabriel Krisman Bertazi #include <linux/unicode.h> 303dcf5451SChristoph Hellwig #include "ext4.h" 3165d165d9STao Ma #include "xattr.h" 32ac27a0ecSDave Kleikamp 33725bebb2SAl Viro static int ext4_dx_readdir(struct file *, struct dir_context *); 34ac27a0ecSDave Kleikamp 35d1f5273eSFan Yong /** 36c60990b3STheodore Ts'o * is_dx_dir() - check if a directory is using htree indexing 37c60990b3STheodore Ts'o * @inode: directory inode 38c60990b3STheodore Ts'o * 39d1f5273eSFan Yong * Check if the given dir-inode refers to an htree-indexed directory 4070261f56SAnatol Pomozov * (or a directory which could potentially get converted to use htree 41d1f5273eSFan Yong * indexing). 42d1f5273eSFan Yong * 43d1f5273eSFan Yong * Return 1 if it is a dx dir, 0 if not 44d1f5273eSFan Yong */ 45d1f5273eSFan Yong static int is_dx_dir(struct inode *inode) 46d1f5273eSFan Yong { 47d1f5273eSFan Yong struct super_block *sb = inode->i_sb; 48d1f5273eSFan Yong 49e2b911c5SDarrick J. Wong if (ext4_has_feature_dir_index(inode->i_sb) && 50d1f5273eSFan Yong ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) || 518af0f082STao Ma ((inode->i_size >> sb->s_blocksize_bits) == 1) || 528af0f082STao Ma ext4_has_inline_data(inode))) 53d1f5273eSFan Yong return 1; 54d1f5273eSFan Yong 55d1f5273eSFan Yong return 0; 56d1f5273eSFan Yong } 57d1f5273eSFan Yong 58cad3f007STheodore Ts'o /* 59cad3f007STheodore Ts'o * Return 0 if the directory entry is OK, and 1 if there is a problem 60cad3f007STheodore Ts'o * 61cad3f007STheodore Ts'o * Note: this is the opposite of what ext2 and ext3 historically returned... 6265d165d9STao Ma * 6365d165d9STao Ma * bh passed here can be an inode block or a dir data block, depending 6465d165d9STao Ma * on the inode inline data flag. 65cad3f007STheodore Ts'o */ 6660fd4da3STheodore Ts'o int __ext4_check_dir_entry(const char *function, unsigned int line, 67f7c21177STheodore Ts'o struct inode *dir, struct file *filp, 68617ba13bSMingming Cao struct ext4_dir_entry_2 *de, 69226ba972STao Ma struct buffer_head *bh, char *buf, int size, 70498e5f24STheodore Ts'o unsigned int offset) 71ac27a0ecSDave Kleikamp { 72ac27a0ecSDave Kleikamp const char *error_msg = NULL; 733d0518f4SWei Yongjun const int rlen = ext4_rec_len_from_disk(de->rec_len, 743d0518f4SWei Yongjun dir->i_sb->s_blocksize); 75707d1a2fSTheodore Ts'o const int next_offset = ((char *) de - buf) + rlen; 76ac27a0ecSDave Kleikamp 77cad3f007STheodore Ts'o if (unlikely(rlen < EXT4_DIR_REC_LEN(1))) 78ac27a0ecSDave Kleikamp error_msg = "rec_len is smaller than minimal"; 79cad3f007STheodore Ts'o else if (unlikely(rlen % 4 != 0)) 80ac27a0ecSDave Kleikamp error_msg = "rec_len % 4 != 0"; 81cad3f007STheodore Ts'o else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len))) 82ac27a0ecSDave Kleikamp error_msg = "rec_len is too small for name_len"; 83707d1a2fSTheodore Ts'o else if (unlikely(next_offset > size)) 844d982e25STheodore Ts'o error_msg = "directory entry overrun"; 85707d1a2fSTheodore Ts'o else if (unlikely(next_offset > size - EXT4_DIR_REC_LEN(1) && 86707d1a2fSTheodore Ts'o next_offset != size)) 87109ba779SJan Kara error_msg = "directory entry too close to block end"; 88cad3f007STheodore Ts'o else if (unlikely(le32_to_cpu(de->inode) > 89cad3f007STheodore Ts'o le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))) 90ac27a0ecSDave Kleikamp error_msg = "inode out of bounds"; 91cad3f007STheodore Ts'o else 92cad3f007STheodore Ts'o return 0; 93ac27a0ecSDave Kleikamp 94f7c21177STheodore Ts'o if (filp) 954fda4003SDan Carpenter ext4_error_file(filp, function, line, bh->b_blocknr, 964d982e25STheodore Ts'o "bad entry in directory: %s - offset=%u, " 974d982e25STheodore Ts'o "inode=%u, rec_len=%d, name_len=%d, size=%d", 984d982e25STheodore Ts'o error_msg, offset, le32_to_cpu(de->inode), 994d982e25STheodore Ts'o rlen, de->name_len, size); 100f7c21177STheodore Ts'o else 1014fda4003SDan Carpenter ext4_error_inode(dir, function, line, bh->b_blocknr, 1024d982e25STheodore Ts'o "bad entry in directory: %s - offset=%u, " 1034d982e25STheodore Ts'o "inode=%u, rec_len=%d, name_len=%d, size=%d", 1044d982e25STheodore Ts'o error_msg, offset, le32_to_cpu(de->inode), 1054d982e25STheodore Ts'o rlen, de->name_len, size); 106f7c21177STheodore Ts'o 107cad3f007STheodore Ts'o return 1; 108ac27a0ecSDave Kleikamp } 109ac27a0ecSDave Kleikamp 110725bebb2SAl Viro static int ext4_readdir(struct file *file, struct dir_context *ctx) 111ac27a0ecSDave Kleikamp { 112498e5f24STheodore Ts'o unsigned int offset; 113aa13d5f6SGiedrius Rekasius int i; 114617ba13bSMingming Cao struct ext4_dir_entry_2 *de; 115ac27a0ecSDave Kleikamp int err; 116725bebb2SAl Viro struct inode *inode = file_inode(file); 117d1f5273eSFan Yong struct super_block *sb = inode->i_sb; 11844614711SMichael Halcrow struct buffer_head *bh = NULL; 119a7550b30SJaegeuk Kim struct fscrypt_str fstr = FSTR_INIT(NULL, 0); 120ac27a0ecSDave Kleikamp 121592ddec7SChandan Rajendra if (IS_ENCRYPTED(inode)) { 122a7550b30SJaegeuk Kim err = fscrypt_get_encryption_info(inode); 12328b4c263STheodore Ts'o if (err && err != -ENOKEY) 12428b4c263STheodore Ts'o return err; 12528b4c263STheodore Ts'o } 12628b4c263STheodore Ts'o 127d1f5273eSFan Yong if (is_dx_dir(inode)) { 128725bebb2SAl Viro err = ext4_dx_readdir(file, ctx); 129ac27a0ecSDave Kleikamp if (err != ERR_BAD_DX_DIR) { 130725bebb2SAl Viro return err; 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 */ 136725bebb2SAl Viro ext4_clear_inode_flag(file_inode(file), 13707a03824STheodore Ts'o EXT4_INODE_INDEX); 138ac27a0ecSDave Kleikamp } 1398af0f082STao Ma 1408af0f082STao Ma if (ext4_has_inline_data(inode)) { 1418af0f082STao Ma int has_inline_data = 1; 14244614711SMichael Halcrow err = ext4_read_inline_dir(file, ctx, 1438af0f082STao Ma &has_inline_data); 1448af0f082STao Ma if (has_inline_data) 14544614711SMichael Halcrow return err; 14644614711SMichael Halcrow } 14744614711SMichael Halcrow 148592ddec7SChandan Rajendra if (IS_ENCRYPTED(inode)) { 149a7550b30SJaegeuk Kim err = fscrypt_fname_alloc_buffer(inode, EXT4_NAME_LEN, &fstr); 150b7236e21STheodore Ts'o if (err < 0) 151b7236e21STheodore Ts'o return err; 1528af0f082STao Ma } 1538af0f082STao Ma 154725bebb2SAl Viro while (ctx->pos < inode->i_size) { 1552ed88685STheodore Ts'o struct ext4_map_blocks map; 156ac27a0ecSDave Kleikamp 1571f60fbe7STheodore Ts'o if (fatal_signal_pending(current)) { 1581f60fbe7STheodore Ts'o err = -ERESTARTSYS; 1591f60fbe7STheodore Ts'o goto errout; 1601f60fbe7STheodore Ts'o } 1611f60fbe7STheodore Ts'o cond_resched(); 1624e19d6b6STheodore Ts'o offset = ctx->pos & (sb->s_blocksize - 1); 163725bebb2SAl Viro map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb); 1642ed88685STheodore Ts'o map.m_len = 1; 1652ed88685STheodore Ts'o err = ext4_map_blocks(NULL, inode, &map, 0); 1664e19d6b6STheodore Ts'o if (err == 0) { 1674e19d6b6STheodore Ts'o /* m_len should never be zero but let's avoid 1684e19d6b6STheodore Ts'o * an infinite loop if it somehow is */ 1694e19d6b6STheodore Ts'o if (map.m_len == 0) 1704e19d6b6STheodore Ts'o map.m_len = 1; 1714e19d6b6STheodore Ts'o ctx->pos += map.m_len * sb->s_blocksize; 1724e19d6b6STheodore Ts'o continue; 1734e19d6b6STheodore Ts'o } 174ac27a0ecSDave Kleikamp if (err > 0) { 1752ed88685STheodore Ts'o pgoff_t index = map.m_pblk >> 17609cbfeafSKirill A. Shutemov (PAGE_SHIFT - inode->i_blkbits); 177725bebb2SAl Viro if (!ra_has_index(&file->f_ra, index)) 178cf914a7dSRusty Russell page_cache_sync_readahead( 179dc7868fcSFengguang Wu sb->s_bdev->bd_inode->i_mapping, 180725bebb2SAl Viro &file->f_ra, file, 181cf914a7dSRusty Russell index, 1); 18209cbfeafSKirill A. Shutemov file->f_ra.prev_pos = (loff_t)index << PAGE_SHIFT; 1831c215028STheodore Ts'o bh = ext4_bread(NULL, inode, map.m_lblk, 0); 184c906f38eSKirill Tkhai if (IS_ERR(bh)) { 185c906f38eSKirill Tkhai err = PTR_ERR(bh); 186c906f38eSKirill Tkhai bh = NULL; 187c906f38eSKirill Tkhai goto errout; 188c906f38eSKirill Tkhai } 189ac27a0ecSDave Kleikamp } 190ac27a0ecSDave Kleikamp 191ac27a0ecSDave Kleikamp if (!bh) { 192e6c40211SEric Sandeen /* corrupt size? Maybe no more blocks to read */ 193725bebb2SAl Viro if (ctx->pos > inode->i_blocks << 9) 194e6c40211SEric Sandeen break; 195725bebb2SAl Viro ctx->pos += sb->s_blocksize - offset; 196ac27a0ecSDave Kleikamp continue; 197ac27a0ecSDave Kleikamp } 198ac27a0ecSDave Kleikamp 199b0336e8dSDarrick J. Wong /* Check the checksum */ 200b0336e8dSDarrick J. Wong if (!buffer_verified(bh) && 201f036adb3STheodore Ts'o !ext4_dirblock_csum_verify(inode, bh)) { 202725bebb2SAl Viro EXT4_ERROR_FILE(file, 0, "directory fails checksum " 203b0336e8dSDarrick J. Wong "at offset %llu", 204725bebb2SAl Viro (unsigned long long)ctx->pos); 205725bebb2SAl Viro ctx->pos += sb->s_blocksize - offset; 206d5ac7773SGuo Chao brelse(bh); 20744614711SMichael Halcrow bh = NULL; 208b0336e8dSDarrick J. Wong continue; 209b0336e8dSDarrick J. Wong } 210b0336e8dSDarrick J. Wong set_buffer_verified(bh); 211b0336e8dSDarrick J. Wong 212ac27a0ecSDave Kleikamp /* If the dir block has changed since the last call to 213ac27a0ecSDave Kleikamp * readdir(2), then we might be pointing to an invalid 214ac27a0ecSDave Kleikamp * dirent right now. Scan from the start of the block 215ac27a0ecSDave Kleikamp * to make sure. */ 216c472c07bSGoffredo Baroncelli if (!inode_eq_iversion(inode, file->f_version)) { 217ac27a0ecSDave Kleikamp for (i = 0; i < sb->s_blocksize && i < offset; ) { 218617ba13bSMingming Cao de = (struct ext4_dir_entry_2 *) 219ac27a0ecSDave Kleikamp (bh->b_data + i); 220ac27a0ecSDave Kleikamp /* It's too expensive to do a full 221ac27a0ecSDave Kleikamp * dirent test each time round this 222ac27a0ecSDave Kleikamp * loop, but we do have to test at 223ac27a0ecSDave Kleikamp * least that it is non-zero. A 224ac27a0ecSDave Kleikamp * failure will be detected in the 225ac27a0ecSDave Kleikamp * dirent test below. */ 2263d0518f4SWei Yongjun if (ext4_rec_len_from_disk(de->rec_len, 2273d0518f4SWei Yongjun sb->s_blocksize) < EXT4_DIR_REC_LEN(1)) 228ac27a0ecSDave Kleikamp break; 2293d0518f4SWei Yongjun i += ext4_rec_len_from_disk(de->rec_len, 2303d0518f4SWei Yongjun sb->s_blocksize); 231ac27a0ecSDave Kleikamp } 232ac27a0ecSDave Kleikamp offset = i; 233725bebb2SAl Viro ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) 234ac27a0ecSDave Kleikamp | offset; 235ee73f9a5SJeff Layton file->f_version = inode_query_iversion(inode); 236ac27a0ecSDave Kleikamp } 237ac27a0ecSDave Kleikamp 238725bebb2SAl Viro while (ctx->pos < inode->i_size 239ac27a0ecSDave Kleikamp && offset < sb->s_blocksize) { 240617ba13bSMingming Cao de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); 241725bebb2SAl Viro if (ext4_check_dir_entry(inode, file, de, bh, 242226ba972STao Ma bh->b_data, bh->b_size, 243226ba972STao Ma offset)) { 24463f57933SAndrew Morton /* 245725bebb2SAl Viro * On error, skip to the next block 24663f57933SAndrew Morton */ 247725bebb2SAl Viro ctx->pos = (ctx->pos | 248ac27a0ecSDave Kleikamp (sb->s_blocksize - 1)) + 1; 249725bebb2SAl Viro break; 250ac27a0ecSDave Kleikamp } 2513d0518f4SWei Yongjun offset += ext4_rec_len_from_disk(de->rec_len, 2523d0518f4SWei Yongjun sb->s_blocksize); 253ac27a0ecSDave Kleikamp if (le32_to_cpu(de->inode)) { 254592ddec7SChandan Rajendra if (!IS_ENCRYPTED(inode)) { 255725bebb2SAl Viro if (!dir_emit(ctx, de->name, 256ac27a0ecSDave Kleikamp de->name_len, 257ac27a0ecSDave Kleikamp le32_to_cpu(de->inode), 25844614711SMichael Halcrow get_dtype(sb, de->file_type))) 25944614711SMichael Halcrow goto done; 26044614711SMichael Halcrow } else { 261a7550b30SJaegeuk Kim int save_len = fstr.len; 262a7550b30SJaegeuk Kim struct fscrypt_str de_name = 263a7550b30SJaegeuk Kim FSTR_INIT(de->name, 264a7550b30SJaegeuk Kim de->name_len); 265d2299590STheodore Ts'o 26644614711SMichael Halcrow /* Directory is encrypted */ 267a7550b30SJaegeuk Kim err = fscrypt_fname_disk_to_usr(inode, 268a7550b30SJaegeuk Kim 0, 0, &de_name, &fstr); 269ef1eb3aaSEric Biggers de_name = fstr; 270a7550b30SJaegeuk Kim fstr.len = save_len; 271ef1eb3aaSEric Biggers if (err) 27244614711SMichael Halcrow goto errout; 27344614711SMichael Halcrow if (!dir_emit(ctx, 274ef1eb3aaSEric Biggers de_name.name, de_name.len, 27544614711SMichael Halcrow le32_to_cpu(de->inode), 27644614711SMichael Halcrow get_dtype(sb, de->file_type))) 27744614711SMichael Halcrow goto done; 278ac27a0ecSDave Kleikamp } 279725bebb2SAl Viro } 280725bebb2SAl Viro ctx->pos += ext4_rec_len_from_disk(de->rec_len, 2813d0518f4SWei Yongjun sb->s_blocksize); 282ac27a0ecSDave Kleikamp } 283ae05327aSAl Viro if ((ctx->pos < inode->i_size) && !dir_relax_shared(inode)) 28444614711SMichael Halcrow goto done; 285ac27a0ecSDave Kleikamp brelse(bh); 28644614711SMichael Halcrow bh = NULL; 28744614711SMichael Halcrow offset = 0; 288ac27a0ecSDave Kleikamp } 28944614711SMichael Halcrow done: 29044614711SMichael Halcrow err = 0; 29144614711SMichael Halcrow errout: 292a7550b30SJaegeuk Kim fscrypt_fname_free_buffer(&fstr); 29344614711SMichael Halcrow brelse(bh); 29444614711SMichael Halcrow return err; 295ac27a0ecSDave Kleikamp } 296ac27a0ecSDave Kleikamp 297d1f5273eSFan Yong static inline int is_32bit_api(void) 298d1f5273eSFan Yong { 299d1f5273eSFan Yong #ifdef CONFIG_COMPAT 300121cef8fSAndy Lutomirski return in_compat_syscall(); 301d1f5273eSFan Yong #else 302d1f5273eSFan Yong return (BITS_PER_LONG == 32); 303d1f5273eSFan Yong #endif 304d1f5273eSFan Yong } 305d1f5273eSFan Yong 306ac27a0ecSDave Kleikamp /* 307ac27a0ecSDave Kleikamp * These functions convert from the major/minor hash to an f_pos 308d1f5273eSFan Yong * value for dx directories 309ac27a0ecSDave Kleikamp * 310d1f5273eSFan Yong * Upper layer (for example NFS) should specify FMODE_32BITHASH or 311d1f5273eSFan Yong * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted 312d1f5273eSFan Yong * directly on both 32-bit and 64-bit nodes, under such case, neither 313d1f5273eSFan Yong * FMODE_32BITHASH nor FMODE_64BITHASH is specified. 314ac27a0ecSDave Kleikamp */ 315d1f5273eSFan Yong static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor) 316d1f5273eSFan Yong { 317d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 318d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 319d1f5273eSFan Yong return major >> 1; 320d1f5273eSFan Yong else 321d1f5273eSFan Yong return ((__u64)(major >> 1) << 32) | (__u64)minor; 322d1f5273eSFan Yong } 323d1f5273eSFan Yong 324d1f5273eSFan Yong static inline __u32 pos2maj_hash(struct file *filp, loff_t pos) 325d1f5273eSFan Yong { 326d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 327d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 328d1f5273eSFan Yong return (pos << 1) & 0xffffffff; 329d1f5273eSFan Yong else 330d1f5273eSFan Yong return ((pos >> 32) << 1) & 0xffffffff; 331d1f5273eSFan Yong } 332d1f5273eSFan Yong 333d1f5273eSFan Yong static inline __u32 pos2min_hash(struct file *filp, loff_t pos) 334d1f5273eSFan Yong { 335d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 336d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 337d1f5273eSFan Yong return 0; 338d1f5273eSFan Yong else 339d1f5273eSFan Yong return pos & 0xffffffff; 340d1f5273eSFan Yong } 341d1f5273eSFan Yong 342d1f5273eSFan Yong /* 343d1f5273eSFan Yong * Return 32- or 64-bit end-of-file for dx directories 344d1f5273eSFan Yong */ 345d1f5273eSFan Yong static inline loff_t ext4_get_htree_eof(struct file *filp) 346d1f5273eSFan Yong { 347d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 348d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 349d1f5273eSFan Yong return EXT4_HTREE_EOF_32BIT; 350d1f5273eSFan Yong else 351d1f5273eSFan Yong return EXT4_HTREE_EOF_64BIT; 352d1f5273eSFan Yong } 353d1f5273eSFan Yong 354d1f5273eSFan Yong 355d1f5273eSFan Yong /* 356ec7268ceSEric Sandeen * ext4_dir_llseek() calls generic_file_llseek_size to handle htree 357ec7268ceSEric Sandeen * directories, where the "offset" is in terms of the filename hash 358ec7268ceSEric Sandeen * value instead of the byte offset. 359d1f5273eSFan Yong * 360ec7268ceSEric Sandeen * Because we may return a 64-bit hash that is well beyond offset limits, 361ec7268ceSEric Sandeen * we need to pass the max hash as the maximum allowable offset in 362ec7268ceSEric Sandeen * the htree directory case. 363ec7268ceSEric Sandeen * 364ec7268ceSEric Sandeen * For non-htree, ext4_llseek already chooses the proper max offset. 365d1f5273eSFan Yong */ 366d4e43954SZheng Liu static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence) 367d1f5273eSFan Yong { 368d1f5273eSFan Yong struct inode *inode = file->f_mapping->host; 369d1f5273eSFan Yong int dx_dir = is_dx_dir(inode); 370e40ff213STheodore Ts'o loff_t ret, htree_max = ext4_get_htree_eof(file); 371d1f5273eSFan Yong 372ec7268ceSEric Sandeen if (likely(dx_dir)) 373e40ff213STheodore Ts'o ret = generic_file_llseek_size(file, offset, whence, 374ec7268ceSEric Sandeen htree_max, htree_max); 375d1f5273eSFan Yong else 376e40ff213STheodore Ts'o ret = ext4_llseek(file, offset, whence); 377e40ff213STheodore Ts'o file->f_version = inode_peek_iversion(inode) - 1; 378e40ff213STheodore Ts'o return ret; 379d1f5273eSFan Yong } 380ac27a0ecSDave Kleikamp 381ac27a0ecSDave Kleikamp /* 382ac27a0ecSDave Kleikamp * This structure holds the nodes of the red-black tree used to store 383ac27a0ecSDave Kleikamp * the directory entry in hash order. 384ac27a0ecSDave Kleikamp */ 385ac27a0ecSDave Kleikamp struct fname { 386ac27a0ecSDave Kleikamp __u32 hash; 387ac27a0ecSDave Kleikamp __u32 minor_hash; 388ac27a0ecSDave Kleikamp struct rb_node rb_hash; 389ac27a0ecSDave Kleikamp struct fname *next; 390ac27a0ecSDave Kleikamp __u32 inode; 391ac27a0ecSDave Kleikamp __u8 name_len; 392ac27a0ecSDave Kleikamp __u8 file_type; 393ac27a0ecSDave Kleikamp char name[0]; 394ac27a0ecSDave Kleikamp }; 395ac27a0ecSDave Kleikamp 396ac27a0ecSDave Kleikamp /* 397ac27a0ecSDave Kleikamp * This functoin implements a non-recursive way of freeing all of the 398ac27a0ecSDave Kleikamp * nodes in the red-black tree. 399ac27a0ecSDave Kleikamp */ 400ac27a0ecSDave Kleikamp static void free_rb_tree_fname(struct rb_root *root) 401ac27a0ecSDave Kleikamp { 402d1866bd0SCody P Schafer struct fname *fname, *next; 403ac27a0ecSDave Kleikamp 404d1866bd0SCody P Schafer rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash) 405ac27a0ecSDave Kleikamp while (fname) { 406ac27a0ecSDave Kleikamp struct fname *old = fname; 407ac27a0ecSDave Kleikamp fname = fname->next; 408ac27a0ecSDave Kleikamp kfree(old); 409ac27a0ecSDave Kleikamp } 410d1866bd0SCody P Schafer 41164e290ecSVenkatesh Pallipadi *root = RB_ROOT; 412ac27a0ecSDave Kleikamp } 413ac27a0ecSDave Kleikamp 414ac27a0ecSDave Kleikamp 415d1f5273eSFan Yong static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp, 416d1f5273eSFan Yong loff_t pos) 417ac27a0ecSDave Kleikamp { 418ac27a0ecSDave Kleikamp struct dir_private_info *p; 419ac27a0ecSDave Kleikamp 420d695a1beSMarkus Elfring p = kzalloc(sizeof(*p), GFP_KERNEL); 421ac27a0ecSDave Kleikamp if (!p) 422ac27a0ecSDave Kleikamp return NULL; 423d1f5273eSFan Yong p->curr_hash = pos2maj_hash(filp, pos); 424d1f5273eSFan Yong p->curr_minor_hash = pos2min_hash(filp, pos); 425ac27a0ecSDave Kleikamp return p; 426ac27a0ecSDave Kleikamp } 427ac27a0ecSDave Kleikamp 428617ba13bSMingming Cao void ext4_htree_free_dir_info(struct dir_private_info *p) 429ac27a0ecSDave Kleikamp { 430ac27a0ecSDave Kleikamp free_rb_tree_fname(&p->root); 431ac27a0ecSDave Kleikamp kfree(p); 432ac27a0ecSDave Kleikamp } 433ac27a0ecSDave Kleikamp 434ac27a0ecSDave Kleikamp /* 435ac27a0ecSDave Kleikamp * Given a directory entry, enter it into the fname rb tree. 4362f61830aSTheodore Ts'o * 4372f61830aSTheodore Ts'o * When filename encryption is enabled, the dirent will hold the 4382f61830aSTheodore Ts'o * encrypted filename, while the htree will hold decrypted filename. 4392f61830aSTheodore Ts'o * The decrypted filename is passed in via ent_name. parameter. 440ac27a0ecSDave Kleikamp */ 441617ba13bSMingming Cao int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, 442ac27a0ecSDave Kleikamp __u32 minor_hash, 4432f61830aSTheodore Ts'o struct ext4_dir_entry_2 *dirent, 444a7550b30SJaegeuk Kim struct fscrypt_str *ent_name) 445ac27a0ecSDave Kleikamp { 446ac27a0ecSDave Kleikamp struct rb_node **p, *parent = NULL; 447ac27a0ecSDave Kleikamp struct fname *fname, *new_fn; 448ac27a0ecSDave Kleikamp struct dir_private_info *info; 449ac27a0ecSDave Kleikamp int len; 450ac27a0ecSDave Kleikamp 451a271fe85SJoe Perches info = dir_file->private_data; 452ac27a0ecSDave Kleikamp p = &info->root.rb_node; 453ac27a0ecSDave Kleikamp 454ac27a0ecSDave Kleikamp /* Create and allocate the fname structure */ 4552f61830aSTheodore Ts'o len = sizeof(struct fname) + ent_name->len + 1; 456ac27a0ecSDave Kleikamp new_fn = kzalloc(len, GFP_KERNEL); 457ac27a0ecSDave Kleikamp if (!new_fn) 458ac27a0ecSDave Kleikamp return -ENOMEM; 459ac27a0ecSDave Kleikamp new_fn->hash = hash; 460ac27a0ecSDave Kleikamp new_fn->minor_hash = minor_hash; 461ac27a0ecSDave Kleikamp new_fn->inode = le32_to_cpu(dirent->inode); 4622f61830aSTheodore Ts'o new_fn->name_len = ent_name->len; 463ac27a0ecSDave Kleikamp new_fn->file_type = dirent->file_type; 4642f61830aSTheodore Ts'o memcpy(new_fn->name, ent_name->name, ent_name->len); 4652f61830aSTheodore Ts'o new_fn->name[ent_name->len] = 0; 466ac27a0ecSDave Kleikamp 467ac27a0ecSDave Kleikamp while (*p) { 468ac27a0ecSDave Kleikamp parent = *p; 469ac27a0ecSDave Kleikamp fname = rb_entry(parent, struct fname, rb_hash); 470ac27a0ecSDave Kleikamp 471ac27a0ecSDave Kleikamp /* 472ac27a0ecSDave Kleikamp * If the hash and minor hash match up, then we put 473ac27a0ecSDave Kleikamp * them on a linked list. This rarely happens... 474ac27a0ecSDave Kleikamp */ 475ac27a0ecSDave Kleikamp if ((new_fn->hash == fname->hash) && 476ac27a0ecSDave Kleikamp (new_fn->minor_hash == fname->minor_hash)) { 477ac27a0ecSDave Kleikamp new_fn->next = fname->next; 478ac27a0ecSDave Kleikamp fname->next = new_fn; 479ac27a0ecSDave Kleikamp return 0; 480ac27a0ecSDave Kleikamp } 481ac27a0ecSDave Kleikamp 482ac27a0ecSDave Kleikamp if (new_fn->hash < fname->hash) 483ac27a0ecSDave Kleikamp p = &(*p)->rb_left; 484ac27a0ecSDave Kleikamp else if (new_fn->hash > fname->hash) 485ac27a0ecSDave Kleikamp p = &(*p)->rb_right; 486ac27a0ecSDave Kleikamp else if (new_fn->minor_hash < fname->minor_hash) 487ac27a0ecSDave Kleikamp p = &(*p)->rb_left; 488ac27a0ecSDave Kleikamp else /* if (new_fn->minor_hash > fname->minor_hash) */ 489ac27a0ecSDave Kleikamp p = &(*p)->rb_right; 490ac27a0ecSDave Kleikamp } 491ac27a0ecSDave Kleikamp 492ac27a0ecSDave Kleikamp rb_link_node(&new_fn->rb_hash, parent, p); 493ac27a0ecSDave Kleikamp rb_insert_color(&new_fn->rb_hash, &info->root); 494ac27a0ecSDave Kleikamp return 0; 495ac27a0ecSDave Kleikamp } 496ac27a0ecSDave Kleikamp 497ac27a0ecSDave Kleikamp 498ac27a0ecSDave Kleikamp 499ac27a0ecSDave Kleikamp /* 500617ba13bSMingming Cao * This is a helper function for ext4_dx_readdir. It calls filldir 501ac27a0ecSDave Kleikamp * for all entres on the fname linked list. (Normally there is only 502ac27a0ecSDave Kleikamp * one entry on the linked list, unless there are 62 bit hash collisions.) 503ac27a0ecSDave Kleikamp */ 504725bebb2SAl Viro static int call_filldir(struct file *file, struct dir_context *ctx, 505725bebb2SAl Viro struct fname *fname) 506ac27a0ecSDave Kleikamp { 507725bebb2SAl Viro struct dir_private_info *info = file->private_data; 508725bebb2SAl Viro struct inode *inode = file_inode(file); 509725bebb2SAl Viro struct super_block *sb = inode->i_sb; 510ac27a0ecSDave Kleikamp 511ac27a0ecSDave Kleikamp if (!fname) { 51292b97816STheodore Ts'o ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: " 51392b97816STheodore Ts'o "called with null fname?!?", __func__, __LINE__, 51492b97816STheodore Ts'o inode->i_ino, current->comm); 515ac27a0ecSDave Kleikamp return 0; 516ac27a0ecSDave Kleikamp } 517725bebb2SAl Viro ctx->pos = hash2pos(file, fname->hash, fname->minor_hash); 518ac27a0ecSDave Kleikamp while (fname) { 519725bebb2SAl Viro if (!dir_emit(ctx, fname->name, 520725bebb2SAl Viro fname->name_len, 521ac27a0ecSDave Kleikamp fname->inode, 522725bebb2SAl Viro get_dtype(sb, fname->file_type))) { 523d0156417STheodore Ts'o info->extra_fname = fname; 524725bebb2SAl Viro return 1; 525ac27a0ecSDave Kleikamp } 526ac27a0ecSDave Kleikamp fname = fname->next; 527ac27a0ecSDave Kleikamp } 528ac27a0ecSDave Kleikamp return 0; 529ac27a0ecSDave Kleikamp } 530ac27a0ecSDave Kleikamp 531725bebb2SAl Viro static int ext4_dx_readdir(struct file *file, struct dir_context *ctx) 532ac27a0ecSDave Kleikamp { 533725bebb2SAl Viro struct dir_private_info *info = file->private_data; 534725bebb2SAl Viro struct inode *inode = file_inode(file); 535ac27a0ecSDave Kleikamp struct fname *fname; 536ac27a0ecSDave Kleikamp int ret; 537ac27a0ecSDave Kleikamp 538ac27a0ecSDave Kleikamp if (!info) { 539725bebb2SAl Viro info = ext4_htree_create_dir_info(file, ctx->pos); 540ac27a0ecSDave Kleikamp if (!info) 541ac27a0ecSDave Kleikamp return -ENOMEM; 542725bebb2SAl Viro file->private_data = info; 543ac27a0ecSDave Kleikamp } 544ac27a0ecSDave Kleikamp 545725bebb2SAl Viro if (ctx->pos == ext4_get_htree_eof(file)) 546ac27a0ecSDave Kleikamp return 0; /* EOF */ 547ac27a0ecSDave Kleikamp 548ac27a0ecSDave Kleikamp /* Some one has messed with f_pos; reset the world */ 549725bebb2SAl Viro if (info->last_pos != ctx->pos) { 550ac27a0ecSDave Kleikamp free_rb_tree_fname(&info->root); 551ac27a0ecSDave Kleikamp info->curr_node = NULL; 552ac27a0ecSDave Kleikamp info->extra_fname = NULL; 553725bebb2SAl Viro info->curr_hash = pos2maj_hash(file, ctx->pos); 554725bebb2SAl Viro info->curr_minor_hash = pos2min_hash(file, ctx->pos); 555ac27a0ecSDave Kleikamp } 556ac27a0ecSDave Kleikamp 557ac27a0ecSDave Kleikamp /* 558ac27a0ecSDave Kleikamp * If there are any leftover names on the hash collision 559ac27a0ecSDave Kleikamp * chain, return them first. 560ac27a0ecSDave Kleikamp */ 561d0156417STheodore Ts'o if (info->extra_fname) { 562725bebb2SAl Viro if (call_filldir(file, ctx, info->extra_fname)) 563ac27a0ecSDave Kleikamp goto finished; 564d0156417STheodore Ts'o info->extra_fname = NULL; 5653c37fc86STheodore Ts'o goto next_node; 566d0156417STheodore Ts'o } else if (!info->curr_node) 567ac27a0ecSDave Kleikamp info->curr_node = rb_first(&info->root); 568ac27a0ecSDave Kleikamp 569ac27a0ecSDave Kleikamp while (1) { 570ac27a0ecSDave Kleikamp /* 571ac27a0ecSDave Kleikamp * Fill the rbtree if we have no more entries, 572ac27a0ecSDave Kleikamp * or the inode has changed since we last read in the 573ac27a0ecSDave Kleikamp * cached entries. 574ac27a0ecSDave Kleikamp */ 575ac27a0ecSDave Kleikamp if ((!info->curr_node) || 576c472c07bSGoffredo Baroncelli !inode_eq_iversion(inode, file->f_version)) { 577ac27a0ecSDave Kleikamp info->curr_node = NULL; 578ac27a0ecSDave Kleikamp free_rb_tree_fname(&info->root); 579ee73f9a5SJeff Layton file->f_version = inode_query_iversion(inode); 580725bebb2SAl Viro ret = ext4_htree_fill_tree(file, info->curr_hash, 581ac27a0ecSDave Kleikamp info->curr_minor_hash, 582ac27a0ecSDave Kleikamp &info->next_hash); 583ac27a0ecSDave Kleikamp if (ret < 0) 584ac27a0ecSDave Kleikamp return ret; 585ac27a0ecSDave Kleikamp if (ret == 0) { 586725bebb2SAl Viro ctx->pos = ext4_get_htree_eof(file); 587ac27a0ecSDave Kleikamp break; 588ac27a0ecSDave Kleikamp } 589ac27a0ecSDave Kleikamp info->curr_node = rb_first(&info->root); 590ac27a0ecSDave Kleikamp } 591ac27a0ecSDave Kleikamp 592ac27a0ecSDave Kleikamp fname = rb_entry(info->curr_node, struct fname, rb_hash); 593ac27a0ecSDave Kleikamp info->curr_hash = fname->hash; 594ac27a0ecSDave Kleikamp info->curr_minor_hash = fname->minor_hash; 595725bebb2SAl Viro if (call_filldir(file, ctx, fname)) 596ac27a0ecSDave Kleikamp break; 5973c37fc86STheodore Ts'o next_node: 598ac27a0ecSDave Kleikamp info->curr_node = rb_next(info->curr_node); 5993c37fc86STheodore Ts'o if (info->curr_node) { 6003c37fc86STheodore Ts'o fname = rb_entry(info->curr_node, struct fname, 6013c37fc86STheodore Ts'o rb_hash); 6023c37fc86STheodore Ts'o info->curr_hash = fname->hash; 6033c37fc86STheodore Ts'o info->curr_minor_hash = fname->minor_hash; 6043c37fc86STheodore Ts'o } else { 605ac27a0ecSDave Kleikamp if (info->next_hash == ~0) { 606725bebb2SAl Viro ctx->pos = ext4_get_htree_eof(file); 607ac27a0ecSDave Kleikamp break; 608ac27a0ecSDave Kleikamp } 609ac27a0ecSDave Kleikamp info->curr_hash = info->next_hash; 610ac27a0ecSDave Kleikamp info->curr_minor_hash = 0; 611ac27a0ecSDave Kleikamp } 612ac27a0ecSDave Kleikamp } 613ac27a0ecSDave Kleikamp finished: 614725bebb2SAl Viro info->last_pos = ctx->pos; 615ac27a0ecSDave Kleikamp return 0; 616ac27a0ecSDave Kleikamp } 617ac27a0ecSDave Kleikamp 6186bc445e0STheodore Ts'o static int ext4_dir_open(struct inode * inode, struct file * filp) 6196bc445e0STheodore Ts'o { 620592ddec7SChandan Rajendra if (IS_ENCRYPTED(inode)) 621a7550b30SJaegeuk Kim return fscrypt_get_encryption_info(inode) ? -EACCES : 0; 6226bc445e0STheodore Ts'o return 0; 6236bc445e0STheodore Ts'o } 6246bc445e0STheodore Ts'o 625617ba13bSMingming Cao static int ext4_release_dir(struct inode *inode, struct file *filp) 626ac27a0ecSDave Kleikamp { 627ac27a0ecSDave Kleikamp if (filp->private_data) 628617ba13bSMingming Cao ext4_htree_free_dir_info(filp->private_data); 629ac27a0ecSDave Kleikamp 630ac27a0ecSDave Kleikamp return 0; 631ac27a0ecSDave Kleikamp } 632d1f5273eSFan Yong 63340b163f1SDarrick J. Wong int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf, 63440b163f1SDarrick J. Wong int buf_size) 63540b163f1SDarrick J. Wong { 63640b163f1SDarrick J. Wong struct ext4_dir_entry_2 *de; 63718017479SEric Engestrom int rlen; 63840b163f1SDarrick J. Wong unsigned int offset = 0; 63940b163f1SDarrick J. Wong char *top; 64040b163f1SDarrick J. Wong 64140b163f1SDarrick J. Wong de = (struct ext4_dir_entry_2 *)buf; 64240b163f1SDarrick J. Wong top = buf + buf_size; 64340b163f1SDarrick J. Wong while ((char *) de < top) { 64440b163f1SDarrick J. Wong if (ext4_check_dir_entry(dir, NULL, de, bh, 64540b163f1SDarrick J. Wong buf, buf_size, offset)) 6466a797d27SDarrick J. Wong return -EFSCORRUPTED; 64740b163f1SDarrick J. Wong rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 64840b163f1SDarrick J. Wong de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 64940b163f1SDarrick J. Wong offset += rlen; 65040b163f1SDarrick J. Wong } 65140b163f1SDarrick J. Wong if ((char *) de > top) 6526a797d27SDarrick J. Wong return -EFSCORRUPTED; 65340b163f1SDarrick J. Wong 65440b163f1SDarrick J. Wong return 0; 65540b163f1SDarrick J. Wong } 65640b163f1SDarrick J. Wong 657d1f5273eSFan Yong const struct file_operations ext4_dir_operations = { 658d1f5273eSFan Yong .llseek = ext4_dir_llseek, 659d1f5273eSFan Yong .read = generic_read_dir, 660ae05327aSAl Viro .iterate_shared = ext4_readdir, 661d1f5273eSFan Yong .unlocked_ioctl = ext4_ioctl, 662d1f5273eSFan Yong #ifdef CONFIG_COMPAT 663d1f5273eSFan Yong .compat_ioctl = ext4_compat_ioctl, 664d1f5273eSFan Yong #endif 665d1f5273eSFan Yong .fsync = ext4_sync_file, 6666bc445e0STheodore Ts'o .open = ext4_dir_open, 667d1f5273eSFan Yong .release = ext4_release_dir, 668d1f5273eSFan Yong }; 669b886ee3eSGabriel Krisman Bertazi 670b886ee3eSGabriel Krisman Bertazi #ifdef CONFIG_UNICODE 671b886ee3eSGabriel Krisman Bertazi static int ext4_d_compare(const struct dentry *dentry, unsigned int len, 672b886ee3eSGabriel Krisman Bertazi const char *str, const struct qstr *name) 673b886ee3eSGabriel Krisman Bertazi { 674b886ee3eSGabriel Krisman Bertazi struct qstr qstr = {.name = str, .len = len }; 6756456ca65STheodore Ts'o struct inode *inode = dentry->d_parent->d_inode; 676b886ee3eSGabriel Krisman Bertazi 6776456ca65STheodore Ts'o if (!IS_CASEFOLDED(inode) || !EXT4_SB(inode->i_sb)->s_encoding) { 678b886ee3eSGabriel Krisman Bertazi if (len != name->len) 679b886ee3eSGabriel Krisman Bertazi return -1; 68066883da1SGabriel Krisman Bertazi return memcmp(str, name->name, len); 681b886ee3eSGabriel Krisman Bertazi } 682b886ee3eSGabriel Krisman Bertazi 6836456ca65STheodore Ts'o return ext4_ci_compare(inode, name, &qstr, false); 684b886ee3eSGabriel Krisman Bertazi } 685b886ee3eSGabriel Krisman Bertazi 686b886ee3eSGabriel Krisman Bertazi static int ext4_d_hash(const struct dentry *dentry, struct qstr *str) 687b886ee3eSGabriel Krisman Bertazi { 688b886ee3eSGabriel Krisman Bertazi const struct ext4_sb_info *sbi = EXT4_SB(dentry->d_sb); 689b886ee3eSGabriel Krisman Bertazi const struct unicode_map *um = sbi->s_encoding; 690b886ee3eSGabriel Krisman Bertazi unsigned char *norm; 691b886ee3eSGabriel Krisman Bertazi int len, ret = 0; 692b886ee3eSGabriel Krisman Bertazi 6936456ca65STheodore Ts'o if (!IS_CASEFOLDED(dentry->d_inode) || !um) 694b886ee3eSGabriel Krisman Bertazi return 0; 695b886ee3eSGabriel Krisman Bertazi 696b886ee3eSGabriel Krisman Bertazi norm = kmalloc(PATH_MAX, GFP_ATOMIC); 697b886ee3eSGabriel Krisman Bertazi if (!norm) 698b886ee3eSGabriel Krisman Bertazi return -ENOMEM; 699b886ee3eSGabriel Krisman Bertazi 700b886ee3eSGabriel Krisman Bertazi len = utf8_casefold(um, str, norm, PATH_MAX); 701b886ee3eSGabriel Krisman Bertazi if (len < 0) { 702b886ee3eSGabriel Krisman Bertazi if (ext4_has_strict_mode(sbi)) 703b886ee3eSGabriel Krisman Bertazi ret = -EINVAL; 704b886ee3eSGabriel Krisman Bertazi goto out; 705b886ee3eSGabriel Krisman Bertazi } 706b886ee3eSGabriel Krisman Bertazi str->hash = full_name_hash(dentry, norm, len); 707b886ee3eSGabriel Krisman Bertazi out: 708b886ee3eSGabriel Krisman Bertazi kfree(norm); 709b886ee3eSGabriel Krisman Bertazi return ret; 710b886ee3eSGabriel Krisman Bertazi } 711b886ee3eSGabriel Krisman Bertazi 712b886ee3eSGabriel Krisman Bertazi const struct dentry_operations ext4_dentry_ops = { 713b886ee3eSGabriel Krisman Bertazi .d_hash = ext4_d_hash, 714b886ee3eSGabriel Krisman Bertazi .d_compare = ext4_d_compare, 715b886ee3eSGabriel Krisman Bertazi }; 716b886ee3eSGabriel Krisman Bertazi #endif 717