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> 293dcf5451SChristoph Hellwig #include "ext4.h" 3065d165d9STao Ma #include "xattr.h" 31ac27a0ecSDave Kleikamp 32725bebb2SAl Viro static int ext4_dx_readdir(struct file *, struct dir_context *); 33ac27a0ecSDave Kleikamp 34d1f5273eSFan Yong /** 35d1f5273eSFan Yong * Check if the given dir-inode refers to an htree-indexed directory 3670261f56SAnatol Pomozov * (or a directory which could potentially get converted to use htree 37d1f5273eSFan Yong * indexing). 38d1f5273eSFan Yong * 39d1f5273eSFan Yong * Return 1 if it is a dx dir, 0 if not 40d1f5273eSFan Yong */ 41d1f5273eSFan Yong static int is_dx_dir(struct inode *inode) 42d1f5273eSFan Yong { 43d1f5273eSFan Yong struct super_block *sb = inode->i_sb; 44d1f5273eSFan Yong 45e2b911c5SDarrick J. Wong if (ext4_has_feature_dir_index(inode->i_sb) && 46d1f5273eSFan Yong ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) || 478af0f082STao Ma ((inode->i_size >> sb->s_blocksize_bits) == 1) || 488af0f082STao Ma ext4_has_inline_data(inode))) 49d1f5273eSFan Yong return 1; 50d1f5273eSFan Yong 51d1f5273eSFan Yong return 0; 52d1f5273eSFan Yong } 53d1f5273eSFan Yong 54cad3f007STheodore Ts'o /* 55cad3f007STheodore Ts'o * Return 0 if the directory entry is OK, and 1 if there is a problem 56cad3f007STheodore Ts'o * 57cad3f007STheodore Ts'o * Note: this is the opposite of what ext2 and ext3 historically returned... 5865d165d9STao Ma * 5965d165d9STao Ma * bh passed here can be an inode block or a dir data block, depending 6065d165d9STao Ma * on the inode inline data flag. 61cad3f007STheodore Ts'o */ 6260fd4da3STheodore Ts'o int __ext4_check_dir_entry(const char *function, unsigned int line, 63f7c21177STheodore Ts'o struct inode *dir, struct file *filp, 64617ba13bSMingming Cao struct ext4_dir_entry_2 *de, 65226ba972STao Ma struct buffer_head *bh, char *buf, int size, 66498e5f24STheodore Ts'o unsigned int offset) 67ac27a0ecSDave Kleikamp { 68ac27a0ecSDave Kleikamp const char *error_msg = NULL; 693d0518f4SWei Yongjun const int rlen = ext4_rec_len_from_disk(de->rec_len, 703d0518f4SWei Yongjun dir->i_sb->s_blocksize); 71ac27a0ecSDave Kleikamp 72cad3f007STheodore Ts'o if (unlikely(rlen < EXT4_DIR_REC_LEN(1))) 73ac27a0ecSDave Kleikamp error_msg = "rec_len is smaller than minimal"; 74cad3f007STheodore Ts'o else if (unlikely(rlen % 4 != 0)) 75ac27a0ecSDave Kleikamp error_msg = "rec_len % 4 != 0"; 76cad3f007STheodore Ts'o else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len))) 77ac27a0ecSDave Kleikamp error_msg = "rec_len is too small for name_len"; 78226ba972STao Ma else if (unlikely(((char *) de - buf) + rlen > size)) 794d982e25STheodore Ts'o error_msg = "directory entry overrun"; 80cad3f007STheodore Ts'o else if (unlikely(le32_to_cpu(de->inode) > 81cad3f007STheodore Ts'o le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))) 82ac27a0ecSDave Kleikamp error_msg = "inode out of bounds"; 83cad3f007STheodore Ts'o else 84cad3f007STheodore Ts'o return 0; 85ac27a0ecSDave Kleikamp 86f7c21177STheodore Ts'o if (filp) 874fda4003SDan Carpenter ext4_error_file(filp, function, line, bh->b_blocknr, 884d982e25STheodore Ts'o "bad entry in directory: %s - offset=%u, " 894d982e25STheodore Ts'o "inode=%u, rec_len=%d, name_len=%d, size=%d", 904d982e25STheodore Ts'o error_msg, offset, le32_to_cpu(de->inode), 914d982e25STheodore Ts'o rlen, de->name_len, size); 92f7c21177STheodore Ts'o else 934fda4003SDan Carpenter ext4_error_inode(dir, function, line, bh->b_blocknr, 944d982e25STheodore Ts'o "bad entry in directory: %s - offset=%u, " 954d982e25STheodore Ts'o "inode=%u, rec_len=%d, name_len=%d, size=%d", 964d982e25STheodore Ts'o error_msg, offset, le32_to_cpu(de->inode), 974d982e25STheodore Ts'o rlen, de->name_len, size); 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; 112a7550b30SJaegeuk Kim struct fscrypt_str fstr = FSTR_INIT(NULL, 0); 113ac27a0ecSDave Kleikamp 11428b4c263STheodore Ts'o if (ext4_encrypted_inode(inode)) { 115a7550b30SJaegeuk Kim err = fscrypt_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)) { 142a7550b30SJaegeuk Kim err = fscrypt_fname_alloc_buffer(inode, EXT4_NAME_LEN, &fstr); 143b7236e21STheodore Ts'o if (err < 0) 144b7236e21STheodore Ts'o return err; 1458af0f082STao Ma } 1468af0f082STao Ma 147725bebb2SAl Viro offset = ctx->pos & (sb->s_blocksize - 1); 148ac27a0ecSDave Kleikamp 149725bebb2SAl Viro while (ctx->pos < inode->i_size) { 1502ed88685STheodore Ts'o struct ext4_map_blocks map; 151ac27a0ecSDave Kleikamp 1521f60fbe7STheodore Ts'o if (fatal_signal_pending(current)) { 1531f60fbe7STheodore Ts'o err = -ERESTARTSYS; 1541f60fbe7STheodore Ts'o goto errout; 1551f60fbe7STheodore Ts'o } 1561f60fbe7STheodore Ts'o cond_resched(); 157725bebb2SAl Viro map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb); 1582ed88685STheodore Ts'o map.m_len = 1; 1592ed88685STheodore Ts'o err = ext4_map_blocks(NULL, inode, &map, 0); 160ac27a0ecSDave Kleikamp if (err > 0) { 1612ed88685STheodore Ts'o pgoff_t index = map.m_pblk >> 16209cbfeafSKirill A. Shutemov (PAGE_SHIFT - inode->i_blkbits); 163725bebb2SAl Viro if (!ra_has_index(&file->f_ra, index)) 164cf914a7dSRusty Russell page_cache_sync_readahead( 165dc7868fcSFengguang Wu sb->s_bdev->bd_inode->i_mapping, 166725bebb2SAl Viro &file->f_ra, file, 167cf914a7dSRusty Russell index, 1); 16809cbfeafSKirill A. Shutemov file->f_ra.prev_pos = (loff_t)index << PAGE_SHIFT; 1691c215028STheodore Ts'o bh = ext4_bread(NULL, inode, map.m_lblk, 0); 170c906f38eSKirill Tkhai if (IS_ERR(bh)) { 171c906f38eSKirill Tkhai err = PTR_ERR(bh); 172c906f38eSKirill Tkhai bh = NULL; 173c906f38eSKirill Tkhai goto errout; 174c906f38eSKirill Tkhai } 175ac27a0ecSDave Kleikamp } 176ac27a0ecSDave Kleikamp 177ac27a0ecSDave Kleikamp if (!bh) { 1789d9f1775SEric Sandeen if (!dir_has_error) { 179725bebb2SAl Viro EXT4_ERROR_FILE(file, 0, 180f7c21177STheodore Ts'o "directory contains a " 181f7c21177STheodore Ts'o "hole at offset %llu", 182725bebb2SAl Viro (unsigned long long) ctx->pos); 1839d9f1775SEric Sandeen dir_has_error = 1; 1849d9f1775SEric Sandeen } 185e6c40211SEric Sandeen /* corrupt size? Maybe no more blocks to read */ 186725bebb2SAl Viro if (ctx->pos > inode->i_blocks << 9) 187e6c40211SEric Sandeen break; 188725bebb2SAl Viro ctx->pos += sb->s_blocksize - offset; 189ac27a0ecSDave Kleikamp continue; 190ac27a0ecSDave Kleikamp } 191ac27a0ecSDave Kleikamp 192b0336e8dSDarrick J. Wong /* Check the checksum */ 193b0336e8dSDarrick J. Wong if (!buffer_verified(bh) && 194b0336e8dSDarrick J. Wong !ext4_dirent_csum_verify(inode, 195b0336e8dSDarrick J. Wong (struct ext4_dir_entry *)bh->b_data)) { 196725bebb2SAl Viro EXT4_ERROR_FILE(file, 0, "directory fails checksum " 197b0336e8dSDarrick J. Wong "at offset %llu", 198725bebb2SAl Viro (unsigned long long)ctx->pos); 199725bebb2SAl Viro ctx->pos += sb->s_blocksize - offset; 200d5ac7773SGuo Chao brelse(bh); 20144614711SMichael Halcrow bh = NULL; 202b0336e8dSDarrick J. Wong continue; 203b0336e8dSDarrick J. Wong } 204b0336e8dSDarrick J. Wong set_buffer_verified(bh); 205b0336e8dSDarrick J. Wong 206ac27a0ecSDave Kleikamp /* If the dir block has changed since the last call to 207ac27a0ecSDave Kleikamp * readdir(2), then we might be pointing to an invalid 208ac27a0ecSDave Kleikamp * dirent right now. Scan from the start of the block 209ac27a0ecSDave Kleikamp * to make sure. */ 210c472c07bSGoffredo Baroncelli if (!inode_eq_iversion(inode, file->f_version)) { 211ac27a0ecSDave Kleikamp for (i = 0; i < sb->s_blocksize && i < offset; ) { 212617ba13bSMingming Cao de = (struct ext4_dir_entry_2 *) 213ac27a0ecSDave Kleikamp (bh->b_data + i); 214ac27a0ecSDave Kleikamp /* It's too expensive to do a full 215ac27a0ecSDave Kleikamp * dirent test each time round this 216ac27a0ecSDave Kleikamp * loop, but we do have to test at 217ac27a0ecSDave Kleikamp * least that it is non-zero. A 218ac27a0ecSDave Kleikamp * failure will be detected in the 219ac27a0ecSDave Kleikamp * dirent test below. */ 2203d0518f4SWei Yongjun if (ext4_rec_len_from_disk(de->rec_len, 2213d0518f4SWei Yongjun sb->s_blocksize) < EXT4_DIR_REC_LEN(1)) 222ac27a0ecSDave Kleikamp break; 2233d0518f4SWei Yongjun i += ext4_rec_len_from_disk(de->rec_len, 2243d0518f4SWei Yongjun sb->s_blocksize); 225ac27a0ecSDave Kleikamp } 226ac27a0ecSDave Kleikamp offset = i; 227725bebb2SAl Viro ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) 228ac27a0ecSDave Kleikamp | offset; 229ee73f9a5SJeff Layton file->f_version = inode_query_iversion(inode); 230ac27a0ecSDave Kleikamp } 231ac27a0ecSDave Kleikamp 232725bebb2SAl Viro while (ctx->pos < inode->i_size 233ac27a0ecSDave Kleikamp && offset < sb->s_blocksize) { 234617ba13bSMingming Cao de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); 235725bebb2SAl Viro if (ext4_check_dir_entry(inode, file, de, bh, 236226ba972STao Ma bh->b_data, bh->b_size, 237226ba972STao Ma offset)) { 23863f57933SAndrew Morton /* 239725bebb2SAl Viro * On error, skip to the next block 24063f57933SAndrew Morton */ 241725bebb2SAl Viro ctx->pos = (ctx->pos | 242ac27a0ecSDave Kleikamp (sb->s_blocksize - 1)) + 1; 243725bebb2SAl Viro break; 244ac27a0ecSDave Kleikamp } 2453d0518f4SWei Yongjun offset += ext4_rec_len_from_disk(de->rec_len, 2463d0518f4SWei Yongjun sb->s_blocksize); 247ac27a0ecSDave Kleikamp if (le32_to_cpu(de->inode)) { 248b7236e21STheodore Ts'o if (!ext4_encrypted_inode(inode)) { 249725bebb2SAl Viro if (!dir_emit(ctx, de->name, 250ac27a0ecSDave Kleikamp de->name_len, 251ac27a0ecSDave Kleikamp le32_to_cpu(de->inode), 25244614711SMichael Halcrow get_dtype(sb, de->file_type))) 25344614711SMichael Halcrow goto done; 25444614711SMichael Halcrow } else { 255a7550b30SJaegeuk Kim int save_len = fstr.len; 256a7550b30SJaegeuk Kim struct fscrypt_str de_name = 257a7550b30SJaegeuk Kim FSTR_INIT(de->name, 258a7550b30SJaegeuk Kim de->name_len); 259d2299590STheodore Ts'o 26044614711SMichael Halcrow /* Directory is encrypted */ 261a7550b30SJaegeuk Kim err = fscrypt_fname_disk_to_usr(inode, 262a7550b30SJaegeuk Kim 0, 0, &de_name, &fstr); 263ef1eb3aaSEric Biggers de_name = fstr; 264a7550b30SJaegeuk Kim fstr.len = save_len; 265ef1eb3aaSEric Biggers if (err) 26644614711SMichael Halcrow goto errout; 26744614711SMichael Halcrow if (!dir_emit(ctx, 268ef1eb3aaSEric Biggers de_name.name, de_name.len, 26944614711SMichael Halcrow le32_to_cpu(de->inode), 27044614711SMichael Halcrow get_dtype(sb, de->file_type))) 27144614711SMichael Halcrow goto done; 272ac27a0ecSDave Kleikamp } 273725bebb2SAl Viro } 274725bebb2SAl Viro ctx->pos += ext4_rec_len_from_disk(de->rec_len, 2753d0518f4SWei Yongjun sb->s_blocksize); 276ac27a0ecSDave Kleikamp } 277ae05327aSAl Viro if ((ctx->pos < inode->i_size) && !dir_relax_shared(inode)) 27844614711SMichael Halcrow goto done; 279ac27a0ecSDave Kleikamp brelse(bh); 28044614711SMichael Halcrow bh = NULL; 28144614711SMichael Halcrow offset = 0; 282ac27a0ecSDave Kleikamp } 28344614711SMichael Halcrow done: 28444614711SMichael Halcrow err = 0; 28544614711SMichael Halcrow errout: 28644614711SMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 287a7550b30SJaegeuk Kim fscrypt_fname_free_buffer(&fstr); 28844614711SMichael Halcrow #endif 28944614711SMichael Halcrow brelse(bh); 29044614711SMichael Halcrow return err; 291ac27a0ecSDave Kleikamp } 292ac27a0ecSDave Kleikamp 293d1f5273eSFan Yong static inline int is_32bit_api(void) 294d1f5273eSFan Yong { 295d1f5273eSFan Yong #ifdef CONFIG_COMPAT 296121cef8fSAndy Lutomirski return in_compat_syscall(); 297d1f5273eSFan Yong #else 298d1f5273eSFan Yong return (BITS_PER_LONG == 32); 299d1f5273eSFan Yong #endif 300d1f5273eSFan Yong } 301d1f5273eSFan Yong 302ac27a0ecSDave Kleikamp /* 303ac27a0ecSDave Kleikamp * These functions convert from the major/minor hash to an f_pos 304d1f5273eSFan Yong * value for dx directories 305ac27a0ecSDave Kleikamp * 306d1f5273eSFan Yong * Upper layer (for example NFS) should specify FMODE_32BITHASH or 307d1f5273eSFan Yong * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted 308d1f5273eSFan Yong * directly on both 32-bit and 64-bit nodes, under such case, neither 309d1f5273eSFan Yong * FMODE_32BITHASH nor FMODE_64BITHASH is specified. 310ac27a0ecSDave Kleikamp */ 311d1f5273eSFan Yong static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor) 312d1f5273eSFan Yong { 313d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 314d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 315d1f5273eSFan Yong return major >> 1; 316d1f5273eSFan Yong else 317d1f5273eSFan Yong return ((__u64)(major >> 1) << 32) | (__u64)minor; 318d1f5273eSFan Yong } 319d1f5273eSFan Yong 320d1f5273eSFan Yong static inline __u32 pos2maj_hash(struct file *filp, loff_t pos) 321d1f5273eSFan Yong { 322d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 323d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 324d1f5273eSFan Yong return (pos << 1) & 0xffffffff; 325d1f5273eSFan Yong else 326d1f5273eSFan Yong return ((pos >> 32) << 1) & 0xffffffff; 327d1f5273eSFan Yong } 328d1f5273eSFan Yong 329d1f5273eSFan Yong static inline __u32 pos2min_hash(struct file *filp, loff_t pos) 330d1f5273eSFan Yong { 331d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 332d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 333d1f5273eSFan Yong return 0; 334d1f5273eSFan Yong else 335d1f5273eSFan Yong return pos & 0xffffffff; 336d1f5273eSFan Yong } 337d1f5273eSFan Yong 338d1f5273eSFan Yong /* 339d1f5273eSFan Yong * Return 32- or 64-bit end-of-file for dx directories 340d1f5273eSFan Yong */ 341d1f5273eSFan Yong static inline loff_t ext4_get_htree_eof(struct file *filp) 342d1f5273eSFan Yong { 343d1f5273eSFan Yong if ((filp->f_mode & FMODE_32BITHASH) || 344d1f5273eSFan Yong (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api())) 345d1f5273eSFan Yong return EXT4_HTREE_EOF_32BIT; 346d1f5273eSFan Yong else 347d1f5273eSFan Yong return EXT4_HTREE_EOF_64BIT; 348d1f5273eSFan Yong } 349d1f5273eSFan Yong 350d1f5273eSFan Yong 351d1f5273eSFan Yong /* 352ec7268ceSEric Sandeen * ext4_dir_llseek() calls generic_file_llseek_size to handle htree 353ec7268ceSEric Sandeen * directories, where the "offset" is in terms of the filename hash 354ec7268ceSEric Sandeen * value instead of the byte offset. 355d1f5273eSFan Yong * 356ec7268ceSEric Sandeen * Because we may return a 64-bit hash that is well beyond offset limits, 357ec7268ceSEric Sandeen * we need to pass the max hash as the maximum allowable offset in 358ec7268ceSEric Sandeen * the htree directory case. 359ec7268ceSEric Sandeen * 360ec7268ceSEric Sandeen * For non-htree, ext4_llseek already chooses the proper max offset. 361d1f5273eSFan Yong */ 362d4e43954SZheng Liu static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence) 363d1f5273eSFan Yong { 364d1f5273eSFan Yong struct inode *inode = file->f_mapping->host; 365d1f5273eSFan Yong int dx_dir = is_dx_dir(inode); 366e40ff213STheodore Ts'o loff_t ret, htree_max = ext4_get_htree_eof(file); 367d1f5273eSFan Yong 368ec7268ceSEric Sandeen if (likely(dx_dir)) 369e40ff213STheodore Ts'o ret = generic_file_llseek_size(file, offset, whence, 370ec7268ceSEric Sandeen htree_max, htree_max); 371d1f5273eSFan Yong else 372e40ff213STheodore Ts'o ret = ext4_llseek(file, offset, whence); 373e40ff213STheodore Ts'o file->f_version = inode_peek_iversion(inode) - 1; 374e40ff213STheodore Ts'o return ret; 375d1f5273eSFan Yong } 376ac27a0ecSDave Kleikamp 377ac27a0ecSDave Kleikamp /* 378ac27a0ecSDave Kleikamp * This structure holds the nodes of the red-black tree used to store 379ac27a0ecSDave Kleikamp * the directory entry in hash order. 380ac27a0ecSDave Kleikamp */ 381ac27a0ecSDave Kleikamp struct fname { 382ac27a0ecSDave Kleikamp __u32 hash; 383ac27a0ecSDave Kleikamp __u32 minor_hash; 384ac27a0ecSDave Kleikamp struct rb_node rb_hash; 385ac27a0ecSDave Kleikamp struct fname *next; 386ac27a0ecSDave Kleikamp __u32 inode; 387ac27a0ecSDave Kleikamp __u8 name_len; 388ac27a0ecSDave Kleikamp __u8 file_type; 389ac27a0ecSDave Kleikamp char name[0]; 390ac27a0ecSDave Kleikamp }; 391ac27a0ecSDave Kleikamp 392ac27a0ecSDave Kleikamp /* 393ac27a0ecSDave Kleikamp * This functoin implements a non-recursive way of freeing all of the 394ac27a0ecSDave Kleikamp * nodes in the red-black tree. 395ac27a0ecSDave Kleikamp */ 396ac27a0ecSDave Kleikamp static void free_rb_tree_fname(struct rb_root *root) 397ac27a0ecSDave Kleikamp { 398d1866bd0SCody P Schafer struct fname *fname, *next; 399ac27a0ecSDave Kleikamp 400d1866bd0SCody P Schafer rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash) 401ac27a0ecSDave Kleikamp while (fname) { 402ac27a0ecSDave Kleikamp struct fname *old = fname; 403ac27a0ecSDave Kleikamp fname = fname->next; 404ac27a0ecSDave Kleikamp kfree(old); 405ac27a0ecSDave Kleikamp } 406d1866bd0SCody P Schafer 40764e290ecSVenkatesh Pallipadi *root = RB_ROOT; 408ac27a0ecSDave Kleikamp } 409ac27a0ecSDave Kleikamp 410ac27a0ecSDave Kleikamp 411d1f5273eSFan Yong static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp, 412d1f5273eSFan Yong loff_t pos) 413ac27a0ecSDave Kleikamp { 414ac27a0ecSDave Kleikamp struct dir_private_info *p; 415ac27a0ecSDave Kleikamp 416d695a1beSMarkus Elfring p = kzalloc(sizeof(*p), GFP_KERNEL); 417ac27a0ecSDave Kleikamp if (!p) 418ac27a0ecSDave Kleikamp return NULL; 419d1f5273eSFan Yong p->curr_hash = pos2maj_hash(filp, pos); 420d1f5273eSFan Yong p->curr_minor_hash = pos2min_hash(filp, pos); 421ac27a0ecSDave Kleikamp return p; 422ac27a0ecSDave Kleikamp } 423ac27a0ecSDave Kleikamp 424617ba13bSMingming Cao void ext4_htree_free_dir_info(struct dir_private_info *p) 425ac27a0ecSDave Kleikamp { 426ac27a0ecSDave Kleikamp free_rb_tree_fname(&p->root); 427ac27a0ecSDave Kleikamp kfree(p); 428ac27a0ecSDave Kleikamp } 429ac27a0ecSDave Kleikamp 430ac27a0ecSDave Kleikamp /* 431ac27a0ecSDave Kleikamp * Given a directory entry, enter it into the fname rb tree. 4322f61830aSTheodore Ts'o * 4332f61830aSTheodore Ts'o * When filename encryption is enabled, the dirent will hold the 4342f61830aSTheodore Ts'o * encrypted filename, while the htree will hold decrypted filename. 4352f61830aSTheodore Ts'o * The decrypted filename is passed in via ent_name. parameter. 436ac27a0ecSDave Kleikamp */ 437617ba13bSMingming Cao int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, 438ac27a0ecSDave Kleikamp __u32 minor_hash, 4392f61830aSTheodore Ts'o struct ext4_dir_entry_2 *dirent, 440a7550b30SJaegeuk Kim struct fscrypt_str *ent_name) 441ac27a0ecSDave Kleikamp { 442ac27a0ecSDave Kleikamp struct rb_node **p, *parent = NULL; 443ac27a0ecSDave Kleikamp struct fname *fname, *new_fn; 444ac27a0ecSDave Kleikamp struct dir_private_info *info; 445ac27a0ecSDave Kleikamp int len; 446ac27a0ecSDave Kleikamp 447a271fe85SJoe Perches info = dir_file->private_data; 448ac27a0ecSDave Kleikamp p = &info->root.rb_node; 449ac27a0ecSDave Kleikamp 450ac27a0ecSDave Kleikamp /* Create and allocate the fname structure */ 4512f61830aSTheodore Ts'o len = sizeof(struct fname) + ent_name->len + 1; 452ac27a0ecSDave Kleikamp new_fn = kzalloc(len, GFP_KERNEL); 453ac27a0ecSDave Kleikamp if (!new_fn) 454ac27a0ecSDave Kleikamp return -ENOMEM; 455ac27a0ecSDave Kleikamp new_fn->hash = hash; 456ac27a0ecSDave Kleikamp new_fn->minor_hash = minor_hash; 457ac27a0ecSDave Kleikamp new_fn->inode = le32_to_cpu(dirent->inode); 4582f61830aSTheodore Ts'o new_fn->name_len = ent_name->len; 459ac27a0ecSDave Kleikamp new_fn->file_type = dirent->file_type; 4602f61830aSTheodore Ts'o memcpy(new_fn->name, ent_name->name, ent_name->len); 4612f61830aSTheodore Ts'o new_fn->name[ent_name->len] = 0; 462ac27a0ecSDave Kleikamp 463ac27a0ecSDave Kleikamp while (*p) { 464ac27a0ecSDave Kleikamp parent = *p; 465ac27a0ecSDave Kleikamp fname = rb_entry(parent, struct fname, rb_hash); 466ac27a0ecSDave Kleikamp 467ac27a0ecSDave Kleikamp /* 468ac27a0ecSDave Kleikamp * If the hash and minor hash match up, then we put 469ac27a0ecSDave Kleikamp * them on a linked list. This rarely happens... 470ac27a0ecSDave Kleikamp */ 471ac27a0ecSDave Kleikamp if ((new_fn->hash == fname->hash) && 472ac27a0ecSDave Kleikamp (new_fn->minor_hash == fname->minor_hash)) { 473ac27a0ecSDave Kleikamp new_fn->next = fname->next; 474ac27a0ecSDave Kleikamp fname->next = new_fn; 475ac27a0ecSDave Kleikamp return 0; 476ac27a0ecSDave Kleikamp } 477ac27a0ecSDave Kleikamp 478ac27a0ecSDave Kleikamp if (new_fn->hash < fname->hash) 479ac27a0ecSDave Kleikamp p = &(*p)->rb_left; 480ac27a0ecSDave Kleikamp else if (new_fn->hash > fname->hash) 481ac27a0ecSDave Kleikamp p = &(*p)->rb_right; 482ac27a0ecSDave Kleikamp else if (new_fn->minor_hash < fname->minor_hash) 483ac27a0ecSDave Kleikamp p = &(*p)->rb_left; 484ac27a0ecSDave Kleikamp else /* if (new_fn->minor_hash > fname->minor_hash) */ 485ac27a0ecSDave Kleikamp p = &(*p)->rb_right; 486ac27a0ecSDave Kleikamp } 487ac27a0ecSDave Kleikamp 488ac27a0ecSDave Kleikamp rb_link_node(&new_fn->rb_hash, parent, p); 489ac27a0ecSDave Kleikamp rb_insert_color(&new_fn->rb_hash, &info->root); 490ac27a0ecSDave Kleikamp return 0; 491ac27a0ecSDave Kleikamp } 492ac27a0ecSDave Kleikamp 493ac27a0ecSDave Kleikamp 494ac27a0ecSDave Kleikamp 495ac27a0ecSDave Kleikamp /* 496617ba13bSMingming Cao * This is a helper function for ext4_dx_readdir. It calls filldir 497ac27a0ecSDave Kleikamp * for all entres on the fname linked list. (Normally there is only 498ac27a0ecSDave Kleikamp * one entry on the linked list, unless there are 62 bit hash collisions.) 499ac27a0ecSDave Kleikamp */ 500725bebb2SAl Viro static int call_filldir(struct file *file, struct dir_context *ctx, 501725bebb2SAl Viro struct fname *fname) 502ac27a0ecSDave Kleikamp { 503725bebb2SAl Viro struct dir_private_info *info = file->private_data; 504725bebb2SAl Viro struct inode *inode = file_inode(file); 505725bebb2SAl Viro struct super_block *sb = inode->i_sb; 506ac27a0ecSDave Kleikamp 507ac27a0ecSDave Kleikamp if (!fname) { 50892b97816STheodore Ts'o ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: " 50992b97816STheodore Ts'o "called with null fname?!?", __func__, __LINE__, 51092b97816STheodore Ts'o inode->i_ino, current->comm); 511ac27a0ecSDave Kleikamp return 0; 512ac27a0ecSDave Kleikamp } 513725bebb2SAl Viro ctx->pos = hash2pos(file, fname->hash, fname->minor_hash); 514ac27a0ecSDave Kleikamp while (fname) { 515725bebb2SAl Viro if (!dir_emit(ctx, fname->name, 516725bebb2SAl Viro fname->name_len, 517ac27a0ecSDave Kleikamp fname->inode, 518725bebb2SAl Viro get_dtype(sb, fname->file_type))) { 519d0156417STheodore Ts'o info->extra_fname = fname; 520725bebb2SAl Viro return 1; 521ac27a0ecSDave Kleikamp } 522ac27a0ecSDave Kleikamp fname = fname->next; 523ac27a0ecSDave Kleikamp } 524ac27a0ecSDave Kleikamp return 0; 525ac27a0ecSDave Kleikamp } 526ac27a0ecSDave Kleikamp 527725bebb2SAl Viro static int ext4_dx_readdir(struct file *file, struct dir_context *ctx) 528ac27a0ecSDave Kleikamp { 529725bebb2SAl Viro struct dir_private_info *info = file->private_data; 530725bebb2SAl Viro struct inode *inode = file_inode(file); 531ac27a0ecSDave Kleikamp struct fname *fname; 532ac27a0ecSDave Kleikamp int ret; 533ac27a0ecSDave Kleikamp 534ac27a0ecSDave Kleikamp if (!info) { 535725bebb2SAl Viro info = ext4_htree_create_dir_info(file, ctx->pos); 536ac27a0ecSDave Kleikamp if (!info) 537ac27a0ecSDave Kleikamp return -ENOMEM; 538725bebb2SAl Viro file->private_data = info; 539ac27a0ecSDave Kleikamp } 540ac27a0ecSDave Kleikamp 541725bebb2SAl Viro if (ctx->pos == ext4_get_htree_eof(file)) 542ac27a0ecSDave Kleikamp return 0; /* EOF */ 543ac27a0ecSDave Kleikamp 544ac27a0ecSDave Kleikamp /* Some one has messed with f_pos; reset the world */ 545725bebb2SAl Viro if (info->last_pos != ctx->pos) { 546ac27a0ecSDave Kleikamp free_rb_tree_fname(&info->root); 547ac27a0ecSDave Kleikamp info->curr_node = NULL; 548ac27a0ecSDave Kleikamp info->extra_fname = NULL; 549725bebb2SAl Viro info->curr_hash = pos2maj_hash(file, ctx->pos); 550725bebb2SAl Viro info->curr_minor_hash = pos2min_hash(file, ctx->pos); 551ac27a0ecSDave Kleikamp } 552ac27a0ecSDave Kleikamp 553ac27a0ecSDave Kleikamp /* 554ac27a0ecSDave Kleikamp * If there are any leftover names on the hash collision 555ac27a0ecSDave Kleikamp * chain, return them first. 556ac27a0ecSDave Kleikamp */ 557d0156417STheodore Ts'o if (info->extra_fname) { 558725bebb2SAl Viro if (call_filldir(file, ctx, info->extra_fname)) 559ac27a0ecSDave Kleikamp goto finished; 560d0156417STheodore Ts'o info->extra_fname = NULL; 5613c37fc86STheodore Ts'o goto next_node; 562d0156417STheodore Ts'o } else if (!info->curr_node) 563ac27a0ecSDave Kleikamp info->curr_node = rb_first(&info->root); 564ac27a0ecSDave Kleikamp 565ac27a0ecSDave Kleikamp while (1) { 566ac27a0ecSDave Kleikamp /* 567ac27a0ecSDave Kleikamp * Fill the rbtree if we have no more entries, 568ac27a0ecSDave Kleikamp * or the inode has changed since we last read in the 569ac27a0ecSDave Kleikamp * cached entries. 570ac27a0ecSDave Kleikamp */ 571ac27a0ecSDave Kleikamp if ((!info->curr_node) || 572c472c07bSGoffredo Baroncelli !inode_eq_iversion(inode, file->f_version)) { 573ac27a0ecSDave Kleikamp info->curr_node = NULL; 574ac27a0ecSDave Kleikamp free_rb_tree_fname(&info->root); 575ee73f9a5SJeff Layton file->f_version = inode_query_iversion(inode); 576725bebb2SAl Viro ret = ext4_htree_fill_tree(file, info->curr_hash, 577ac27a0ecSDave Kleikamp info->curr_minor_hash, 578ac27a0ecSDave Kleikamp &info->next_hash); 579ac27a0ecSDave Kleikamp if (ret < 0) 580ac27a0ecSDave Kleikamp return ret; 581ac27a0ecSDave Kleikamp if (ret == 0) { 582725bebb2SAl Viro ctx->pos = ext4_get_htree_eof(file); 583ac27a0ecSDave Kleikamp break; 584ac27a0ecSDave Kleikamp } 585ac27a0ecSDave Kleikamp info->curr_node = rb_first(&info->root); 586ac27a0ecSDave Kleikamp } 587ac27a0ecSDave Kleikamp 588ac27a0ecSDave Kleikamp fname = rb_entry(info->curr_node, struct fname, rb_hash); 589ac27a0ecSDave Kleikamp info->curr_hash = fname->hash; 590ac27a0ecSDave Kleikamp info->curr_minor_hash = fname->minor_hash; 591725bebb2SAl Viro if (call_filldir(file, ctx, fname)) 592ac27a0ecSDave Kleikamp break; 5933c37fc86STheodore Ts'o next_node: 594ac27a0ecSDave Kleikamp info->curr_node = rb_next(info->curr_node); 5953c37fc86STheodore Ts'o if (info->curr_node) { 5963c37fc86STheodore Ts'o fname = rb_entry(info->curr_node, struct fname, 5973c37fc86STheodore Ts'o rb_hash); 5983c37fc86STheodore Ts'o info->curr_hash = fname->hash; 5993c37fc86STheodore Ts'o info->curr_minor_hash = fname->minor_hash; 6003c37fc86STheodore Ts'o } else { 601ac27a0ecSDave Kleikamp if (info->next_hash == ~0) { 602725bebb2SAl Viro ctx->pos = ext4_get_htree_eof(file); 603ac27a0ecSDave Kleikamp break; 604ac27a0ecSDave Kleikamp } 605ac27a0ecSDave Kleikamp info->curr_hash = info->next_hash; 606ac27a0ecSDave Kleikamp info->curr_minor_hash = 0; 607ac27a0ecSDave Kleikamp } 608ac27a0ecSDave Kleikamp } 609ac27a0ecSDave Kleikamp finished: 610725bebb2SAl Viro info->last_pos = ctx->pos; 611ac27a0ecSDave Kleikamp return 0; 612ac27a0ecSDave Kleikamp } 613ac27a0ecSDave Kleikamp 6146bc445e0STheodore Ts'o static int ext4_dir_open(struct inode * inode, struct file * filp) 6156bc445e0STheodore Ts'o { 6166bc445e0STheodore Ts'o if (ext4_encrypted_inode(inode)) 617a7550b30SJaegeuk Kim return fscrypt_get_encryption_info(inode) ? -EACCES : 0; 6186bc445e0STheodore Ts'o return 0; 6196bc445e0STheodore Ts'o } 6206bc445e0STheodore Ts'o 621617ba13bSMingming Cao static int ext4_release_dir(struct inode *inode, struct file *filp) 622ac27a0ecSDave Kleikamp { 623ac27a0ecSDave Kleikamp if (filp->private_data) 624617ba13bSMingming Cao ext4_htree_free_dir_info(filp->private_data); 625ac27a0ecSDave Kleikamp 626ac27a0ecSDave Kleikamp return 0; 627ac27a0ecSDave Kleikamp } 628d1f5273eSFan Yong 62940b163f1SDarrick J. Wong int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf, 63040b163f1SDarrick J. Wong int buf_size) 63140b163f1SDarrick J. Wong { 63240b163f1SDarrick J. Wong struct ext4_dir_entry_2 *de; 63318017479SEric Engestrom int rlen; 63440b163f1SDarrick J. Wong unsigned int offset = 0; 63540b163f1SDarrick J. Wong char *top; 63640b163f1SDarrick J. Wong 63740b163f1SDarrick J. Wong de = (struct ext4_dir_entry_2 *)buf; 63840b163f1SDarrick J. Wong top = buf + buf_size; 63940b163f1SDarrick J. Wong while ((char *) de < top) { 64040b163f1SDarrick J. Wong if (ext4_check_dir_entry(dir, NULL, de, bh, 64140b163f1SDarrick J. Wong buf, buf_size, offset)) 6426a797d27SDarrick J. Wong return -EFSCORRUPTED; 64340b163f1SDarrick J. Wong rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 64440b163f1SDarrick J. Wong de = (struct ext4_dir_entry_2 *)((char *)de + rlen); 64540b163f1SDarrick J. Wong offset += rlen; 64640b163f1SDarrick J. Wong } 64740b163f1SDarrick J. Wong if ((char *) de > top) 6486a797d27SDarrick J. Wong return -EFSCORRUPTED; 64940b163f1SDarrick J. Wong 65040b163f1SDarrick J. Wong return 0; 65140b163f1SDarrick J. Wong } 65240b163f1SDarrick J. Wong 653d1f5273eSFan Yong const struct file_operations ext4_dir_operations = { 654d1f5273eSFan Yong .llseek = ext4_dir_llseek, 655d1f5273eSFan Yong .read = generic_read_dir, 656ae05327aSAl Viro .iterate_shared = ext4_readdir, 657d1f5273eSFan Yong .unlocked_ioctl = ext4_ioctl, 658d1f5273eSFan Yong #ifdef CONFIG_COMPAT 659d1f5273eSFan Yong .compat_ioctl = ext4_compat_ioctl, 660d1f5273eSFan Yong #endif 661d1f5273eSFan Yong .fsync = ext4_sync_file, 6626bc445e0STheodore Ts'o .open = ext4_dir_open, 663d1f5273eSFan Yong .release = ext4_release_dir, 664d1f5273eSFan Yong }; 665