1b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * linux/fs/affs/dir.c 41da177e4SLinus Torvalds * 51da177e4SLinus Torvalds * (c) 1996 Hans-Joachim Widmaier - Rewritten 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem. 81da177e4SLinus Torvalds * 91da177e4SLinus Torvalds * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. 101da177e4SLinus Torvalds * 111da177e4SLinus Torvalds * (C) 1991 Linus Torvalds - minix filesystem 121da177e4SLinus Torvalds * 131da177e4SLinus Torvalds * affs directory handling functions 141da177e4SLinus Torvalds * 151da177e4SLinus Torvalds */ 161da177e4SLinus Torvalds 171da177e4SLinus Torvalds #include "affs.h" 181da177e4SLinus Torvalds 190edf977dSAl Viro static int affs_readdir(struct file *, struct dir_context *); 201da177e4SLinus Torvalds 214b6f5d20SArjan van de Ven const struct file_operations affs_dir_operations = { 221da177e4SLinus Torvalds .read = generic_read_dir, 2359af1584SAl Viro .llseek = generic_file_llseek, 243b0a3c1aSAl Viro .iterate_shared = affs_readdir, 25c4758795SAl Viro .fsync = affs_file_fsync, 261da177e4SLinus Torvalds }; 271da177e4SLinus Torvalds 281da177e4SLinus Torvalds /* 291da177e4SLinus Torvalds * directories can handle most operations... 301da177e4SLinus Torvalds */ 31754661f1SArjan van de Ven const struct inode_operations affs_dir_inode_operations = { 321da177e4SLinus Torvalds .create = affs_create, 331da177e4SLinus Torvalds .lookup = affs_lookup, 341da177e4SLinus Torvalds .link = affs_link, 351da177e4SLinus Torvalds .unlink = affs_unlink, 361da177e4SLinus Torvalds .symlink = affs_symlink, 371da177e4SLinus Torvalds .mkdir = affs_mkdir, 381da177e4SLinus Torvalds .rmdir = affs_rmdir, 39c6184028SFabian Frederick .rename = affs_rename2, 401da177e4SLinus Torvalds .setattr = affs_notify_change, 411da177e4SLinus Torvalds }; 421da177e4SLinus Torvalds 431da177e4SLinus Torvalds static int 440edf977dSAl Viro affs_readdir(struct file *file, struct dir_context *ctx) 451da177e4SLinus Torvalds { 460edf977dSAl Viro struct inode *inode = file_inode(file); 471da177e4SLinus Torvalds struct super_block *sb = inode->i_sb; 480edf977dSAl Viro struct buffer_head *dir_bh = NULL; 490edf977dSAl Viro struct buffer_head *fh_bh = NULL; 501da177e4SLinus Torvalds unsigned char *name; 511da177e4SLinus Torvalds int namelen; 521da177e4SLinus Torvalds u32 i; 531da177e4SLinus Torvalds int hash_pos; 541da177e4SLinus Torvalds int chain_pos; 551da177e4SLinus Torvalds u32 ino; 56d40c4d46SFabian Frederick int error = 0; 571da177e4SLinus Torvalds 5808fe100dSGeert Uytterhoeven pr_debug("%s(ino=%lu,f_pos=%llx)\n", __func__, inode->i_ino, ctx->pos); 591da177e4SLinus Torvalds 600edf977dSAl Viro if (ctx->pos < 2) { 610edf977dSAl Viro file->private_data = (void *)0; 620edf977dSAl Viro if (!dir_emit_dots(file, ctx)) 631da177e4SLinus Torvalds return 0; 641da177e4SLinus Torvalds } 651da177e4SLinus Torvalds 661da177e4SLinus Torvalds affs_lock_dir(inode); 670edf977dSAl Viro chain_pos = (ctx->pos - 2) & 0xffff; 680edf977dSAl Viro hash_pos = (ctx->pos - 2) >> 16; 691da177e4SLinus Torvalds if (chain_pos == 0xffff) { 701da177e4SLinus Torvalds affs_warning(sb, "readdir", "More than 65535 entries in chain"); 711da177e4SLinus Torvalds chain_pos = 0; 721da177e4SLinus Torvalds hash_pos++; 730edf977dSAl Viro ctx->pos = ((hash_pos << 16) | chain_pos) + 2; 741da177e4SLinus Torvalds } 751da177e4SLinus Torvalds dir_bh = affs_bread(sb, inode->i_ino); 761da177e4SLinus Torvalds if (!dir_bh) 77d40c4d46SFabian Frederick goto out_unlock_dir; 781da177e4SLinus Torvalds 791da177e4SLinus Torvalds /* If the directory hasn't changed since the last call to readdir(), 801da177e4SLinus Torvalds * we can jump directly to where we left off. 811da177e4SLinus Torvalds */ 820edf977dSAl Viro ino = (u32)(long)file->private_data; 830edf977dSAl Viro if (ino && file->f_version == inode->i_version) { 849606d9aaSFabian Frederick pr_debug("readdir() left off=%d\n", ino); 851da177e4SLinus Torvalds goto inside; 861da177e4SLinus Torvalds } 871da177e4SLinus Torvalds 881da177e4SLinus Torvalds ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]); 891da177e4SLinus Torvalds for (i = 0; ino && i < chain_pos; i++) { 901da177e4SLinus Torvalds fh_bh = affs_bread(sb, ino); 911da177e4SLinus Torvalds if (!fh_bh) { 921da177e4SLinus Torvalds affs_error(sb, "readdir","Cannot read block %d", i); 93d40c4d46SFabian Frederick error = -EIO; 94d40c4d46SFabian Frederick goto out_brelse_dir; 951da177e4SLinus Torvalds } 961da177e4SLinus Torvalds ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain); 971da177e4SLinus Torvalds affs_brelse(fh_bh); 981da177e4SLinus Torvalds fh_bh = NULL; 991da177e4SLinus Torvalds } 1001da177e4SLinus Torvalds if (ino) 1011da177e4SLinus Torvalds goto inside; 1021da177e4SLinus Torvalds hash_pos++; 1031da177e4SLinus Torvalds 1041da177e4SLinus Torvalds for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) { 1051da177e4SLinus Torvalds ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]); 1061da177e4SLinus Torvalds if (!ino) 1071da177e4SLinus Torvalds continue; 1080edf977dSAl Viro ctx->pos = (hash_pos << 16) + 2; 1091da177e4SLinus Torvalds inside: 1101da177e4SLinus Torvalds do { 1111da177e4SLinus Torvalds fh_bh = affs_bread(sb, ino); 1121da177e4SLinus Torvalds if (!fh_bh) { 113d40c4d46SFabian Frederick affs_error(sb, "readdir", 114d40c4d46SFabian Frederick "Cannot read block %d", ino); 1150edf977dSAl Viro break; 1161da177e4SLinus Torvalds } 1171da177e4SLinus Torvalds 118f157853eSFabian Frederick namelen = min(AFFS_TAIL(sb, fh_bh)->name[0], 119f157853eSFabian Frederick (u8)AFFSNAMEMAX); 1201da177e4SLinus Torvalds name = AFFS_TAIL(sb, fh_bh)->name + 1; 12108fe100dSGeert Uytterhoeven pr_debug("readdir(): dir_emit(\"%.*s\", ino=%u), hash=%d, f_pos=%llx\n", 12208fe100dSGeert Uytterhoeven namelen, name, ino, hash_pos, ctx->pos); 123d40c4d46SFabian Frederick 1240edf977dSAl Viro if (!dir_emit(ctx, name, namelen, ino, DT_UNKNOWN)) 125d40c4d46SFabian Frederick goto done; 1260edf977dSAl Viro ctx->pos++; 1271da177e4SLinus Torvalds ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain); 1281da177e4SLinus Torvalds affs_brelse(fh_bh); 1291da177e4SLinus Torvalds fh_bh = NULL; 1301da177e4SLinus Torvalds } while (ino); 1311da177e4SLinus Torvalds } 132d40c4d46SFabian Frederick done: 1330edf977dSAl Viro file->f_version = inode->i_version; 1340edf977dSAl Viro file->private_data = (void *)(long)ino; 1351da177e4SLinus Torvalds affs_brelse(fh_bh); 136d40c4d46SFabian Frederick 137d40c4d46SFabian Frederick out_brelse_dir: 138d40c4d46SFabian Frederick affs_brelse(dir_bh); 139d40c4d46SFabian Frederick 140d40c4d46SFabian Frederick out_unlock_dir: 1411da177e4SLinus Torvalds affs_unlock_dir(inode); 142d40c4d46SFabian Frederick return error; 1431da177e4SLinus Torvalds } 144