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
179dffe569SJeff Layton #include <linux/iversion.h>
181da177e4SLinus Torvalds #include "affs.h"
191da177e4SLinus Torvalds
200edf977dSAl Viro static int affs_readdir(struct file *, struct dir_context *);
211da177e4SLinus Torvalds
224b6f5d20SArjan van de Ven const struct file_operations affs_dir_operations = {
231da177e4SLinus Torvalds .read = generic_read_dir,
2459af1584SAl Viro .llseek = generic_file_llseek,
253b0a3c1aSAl Viro .iterate_shared = affs_readdir,
26c4758795SAl Viro .fsync = affs_file_fsync,
271da177e4SLinus Torvalds };
281da177e4SLinus Torvalds
291da177e4SLinus Torvalds /*
301da177e4SLinus Torvalds * directories can handle most operations...
311da177e4SLinus Torvalds */
32754661f1SArjan van de Ven const struct inode_operations affs_dir_inode_operations = {
331da177e4SLinus Torvalds .create = affs_create,
341da177e4SLinus Torvalds .lookup = affs_lookup,
351da177e4SLinus Torvalds .link = affs_link,
361da177e4SLinus Torvalds .unlink = affs_unlink,
371da177e4SLinus Torvalds .symlink = affs_symlink,
381da177e4SLinus Torvalds .mkdir = affs_mkdir,
391da177e4SLinus Torvalds .rmdir = affs_rmdir,
40c6184028SFabian Frederick .rename = affs_rename2,
411da177e4SLinus Torvalds .setattr = affs_notify_change,
421da177e4SLinus Torvalds };
431da177e4SLinus Torvalds
441da177e4SLinus Torvalds static int
affs_readdir(struct file * file,struct dir_context * ctx)450edf977dSAl Viro affs_readdir(struct file *file, struct dir_context *ctx)
461da177e4SLinus Torvalds {
470edf977dSAl Viro struct inode *inode = file_inode(file);
481da177e4SLinus Torvalds struct super_block *sb = inode->i_sb;
490edf977dSAl Viro struct buffer_head *dir_bh = NULL;
500edf977dSAl Viro struct buffer_head *fh_bh = NULL;
511da177e4SLinus Torvalds unsigned char *name;
521da177e4SLinus Torvalds int namelen;
531da177e4SLinus Torvalds u32 i;
541da177e4SLinus Torvalds int hash_pos;
551da177e4SLinus Torvalds int chain_pos;
561da177e4SLinus Torvalds u32 ino;
57d40c4d46SFabian Frederick int error = 0;
581da177e4SLinus Torvalds
5908fe100dSGeert Uytterhoeven pr_debug("%s(ino=%lu,f_pos=%llx)\n", __func__, inode->i_ino, ctx->pos);
601da177e4SLinus Torvalds
610edf977dSAl Viro if (ctx->pos < 2) {
620edf977dSAl Viro file->private_data = (void *)0;
630edf977dSAl Viro if (!dir_emit_dots(file, ctx))
641da177e4SLinus Torvalds return 0;
651da177e4SLinus Torvalds }
661da177e4SLinus Torvalds
671da177e4SLinus Torvalds affs_lock_dir(inode);
680edf977dSAl Viro chain_pos = (ctx->pos - 2) & 0xffff;
690edf977dSAl Viro hash_pos = (ctx->pos - 2) >> 16;
701da177e4SLinus Torvalds if (chain_pos == 0xffff) {
711da177e4SLinus Torvalds affs_warning(sb, "readdir", "More than 65535 entries in chain");
721da177e4SLinus Torvalds chain_pos = 0;
731da177e4SLinus Torvalds hash_pos++;
740edf977dSAl Viro ctx->pos = ((hash_pos << 16) | chain_pos) + 2;
751da177e4SLinus Torvalds }
761da177e4SLinus Torvalds dir_bh = affs_bread(sb, inode->i_ino);
771da177e4SLinus Torvalds if (!dir_bh)
78d40c4d46SFabian Frederick goto out_unlock_dir;
791da177e4SLinus Torvalds
801da177e4SLinus Torvalds /* If the directory hasn't changed since the last call to readdir(),
811da177e4SLinus Torvalds * we can jump directly to where we left off.
821da177e4SLinus Torvalds */
830edf977dSAl Viro ino = (u32)(long)file->private_data;
84c472c07bSGoffredo Baroncelli if (ino && inode_eq_iversion(inode, file->f_version)) {
859606d9aaSFabian Frederick pr_debug("readdir() left off=%d\n", ino);
861da177e4SLinus Torvalds goto inside;
871da177e4SLinus Torvalds }
881da177e4SLinus Torvalds
891da177e4SLinus Torvalds ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
901da177e4SLinus Torvalds for (i = 0; ino && i < chain_pos; i++) {
911da177e4SLinus Torvalds fh_bh = affs_bread(sb, ino);
921da177e4SLinus Torvalds if (!fh_bh) {
931da177e4SLinus Torvalds affs_error(sb, "readdir","Cannot read block %d", i);
94d40c4d46SFabian Frederick error = -EIO;
95d40c4d46SFabian Frederick goto out_brelse_dir;
961da177e4SLinus Torvalds }
971da177e4SLinus Torvalds ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
981da177e4SLinus Torvalds affs_brelse(fh_bh);
991da177e4SLinus Torvalds fh_bh = NULL;
1001da177e4SLinus Torvalds }
1011da177e4SLinus Torvalds if (ino)
1021da177e4SLinus Torvalds goto inside;
1031da177e4SLinus Torvalds hash_pos++;
1041da177e4SLinus Torvalds
1051da177e4SLinus Torvalds for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {
1061da177e4SLinus Torvalds ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
1071da177e4SLinus Torvalds if (!ino)
1081da177e4SLinus Torvalds continue;
1090edf977dSAl Viro ctx->pos = (hash_pos << 16) + 2;
1101da177e4SLinus Torvalds inside:
1111da177e4SLinus Torvalds do {
1121da177e4SLinus Torvalds fh_bh = affs_bread(sb, ino);
1131da177e4SLinus Torvalds if (!fh_bh) {
114d40c4d46SFabian Frederick affs_error(sb, "readdir",
115d40c4d46SFabian Frederick "Cannot read block %d", ino);
1160edf977dSAl Viro break;
1171da177e4SLinus Torvalds }
1181da177e4SLinus Torvalds
119f157853eSFabian Frederick namelen = min(AFFS_TAIL(sb, fh_bh)->name[0],
120f157853eSFabian Frederick (u8)AFFSNAMEMAX);
1211da177e4SLinus Torvalds name = AFFS_TAIL(sb, fh_bh)->name + 1;
12208fe100dSGeert Uytterhoeven pr_debug("readdir(): dir_emit(\"%.*s\", ino=%u), hash=%d, f_pos=%llx\n",
12308fe100dSGeert Uytterhoeven namelen, name, ino, hash_pos, ctx->pos);
124d40c4d46SFabian Frederick
1250edf977dSAl Viro if (!dir_emit(ctx, name, namelen, ino, DT_UNKNOWN))
126d40c4d46SFabian Frederick goto done;
1270edf977dSAl Viro ctx->pos++;
1281da177e4SLinus Torvalds ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
1291da177e4SLinus Torvalds affs_brelse(fh_bh);
1301da177e4SLinus Torvalds fh_bh = NULL;
1311da177e4SLinus Torvalds } while (ino);
1321da177e4SLinus Torvalds }
133d40c4d46SFabian Frederick done:
1349dffe569SJeff Layton file->f_version = inode_query_iversion(inode);
1350edf977dSAl Viro file->private_data = (void *)(long)ino;
1361da177e4SLinus Torvalds affs_brelse(fh_bh);
137d40c4d46SFabian Frederick
138d40c4d46SFabian Frederick out_brelse_dir:
139d40c4d46SFabian Frederick affs_brelse(dir_bh);
140d40c4d46SFabian Frederick
141d40c4d46SFabian Frederick out_unlock_dir:
1421da177e4SLinus Torvalds affs_unlock_dir(inode);
143d40c4d46SFabian Frederick return error;
1441da177e4SLinus Torvalds }
145