145 lines
3.4 KiB
C
145 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* linux/fs/affs/dir.c
|
|
*
|
|
* (c) 1996 Hans-Joachim Widmaier - Rewritten
|
|
*
|
|
* (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
|
|
*
|
|
* (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
|
|
*
|
|
* (C) 1991 Linus Torvalds - minix filesystem
|
|
*
|
|
* affs directory handling functions
|
|
*
|
|
*/
|
|
|
|
#include <linux/iversion.h>
|
|
#include "affs.h"
|
|
|
|
static int affs_readdir(struct file *, struct dir_context *);
|
|
|
|
const struct file_operations affs_dir_operations = {
|
|
.read = generic_read_dir,
|
|
.llseek = generic_file_llseek,
|
|
.iterate_shared = affs_readdir,
|
|
.fsync = affs_file_fsync,
|
|
};
|
|
|
|
/*
|
|
* directories can handle most operations...
|
|
*/
|
|
const struct inode_operations affs_dir_inode_operations = {
|
|
.create = affs_create,
|
|
.lookup = affs_lookup,
|
|
.link = affs_link,
|
|
.unlink = affs_unlink,
|
|
.symlink = affs_symlink,
|
|
.mkdir = affs_mkdir,
|
|
.rmdir = affs_rmdir,
|
|
.rename = affs_rename2,
|
|
.setattr = affs_notify_change,
|
|
};
|
|
|
|
static int
|
|
affs_readdir(struct file *file, struct dir_context *ctx)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
struct super_block *sb = inode->i_sb;
|
|
struct buffer_head *dir_bh = NULL;
|
|
struct buffer_head *fh_bh = NULL;
|
|
unsigned char *name;
|
|
int namelen;
|
|
u32 i;
|
|
int hash_pos;
|
|
int chain_pos;
|
|
u32 ino;
|
|
int error = 0;
|
|
|
|
pr_debug("%s(ino=%lu,f_pos=%llx)\n", __func__, inode->i_ino, ctx->pos);
|
|
|
|
if (ctx->pos < 2) {
|
|
file->private_data = (void *)0;
|
|
if (!dir_emit_dots(file, ctx))
|
|
return 0;
|
|
}
|
|
|
|
affs_lock_dir(inode);
|
|
chain_pos = (ctx->pos - 2) & 0xffff;
|
|
hash_pos = (ctx->pos - 2) >> 16;
|
|
if (chain_pos == 0xffff) {
|
|
affs_warning(sb, "readdir", "More than 65535 entries in chain");
|
|
chain_pos = 0;
|
|
hash_pos++;
|
|
ctx->pos = ((hash_pos << 16) | chain_pos) + 2;
|
|
}
|
|
dir_bh = affs_bread(sb, inode->i_ino);
|
|
if (!dir_bh)
|
|
goto out_unlock_dir;
|
|
|
|
/* If the directory hasn't changed since the last call to readdir(),
|
|
* we can jump directly to where we left off.
|
|
*/
|
|
ino = (u32)(long)file->private_data;
|
|
if (ino && inode_eq_iversion(inode, file->f_version)) {
|
|
pr_debug("readdir() left off=%d\n", ino);
|
|
goto inside;
|
|
}
|
|
|
|
ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
|
|
for (i = 0; ino && i < chain_pos; i++) {
|
|
fh_bh = affs_bread(sb, ino);
|
|
if (!fh_bh) {
|
|
affs_error(sb, "readdir","Cannot read block %d", i);
|
|
error = -EIO;
|
|
goto out_brelse_dir;
|
|
}
|
|
ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
|
|
affs_brelse(fh_bh);
|
|
fh_bh = NULL;
|
|
}
|
|
if (ino)
|
|
goto inside;
|
|
hash_pos++;
|
|
|
|
for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {
|
|
ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
|
|
if (!ino)
|
|
continue;
|
|
ctx->pos = (hash_pos << 16) + 2;
|
|
inside:
|
|
do {
|
|
fh_bh = affs_bread(sb, ino);
|
|
if (!fh_bh) {
|
|
affs_error(sb, "readdir",
|
|
"Cannot read block %d", ino);
|
|
break;
|
|
}
|
|
|
|
namelen = min(AFFS_TAIL(sb, fh_bh)->name[0],
|
|
(u8)AFFSNAMEMAX);
|
|
name = AFFS_TAIL(sb, fh_bh)->name + 1;
|
|
pr_debug("readdir(): dir_emit(\"%.*s\", ino=%u), hash=%d, f_pos=%llx\n",
|
|
namelen, name, ino, hash_pos, ctx->pos);
|
|
|
|
if (!dir_emit(ctx, name, namelen, ino, DT_UNKNOWN))
|
|
goto done;
|
|
ctx->pos++;
|
|
ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
|
|
affs_brelse(fh_bh);
|
|
fh_bh = NULL;
|
|
} while (ino);
|
|
}
|
|
done:
|
|
file->f_version = inode_query_iversion(inode);
|
|
file->private_data = (void *)(long)ino;
|
|
affs_brelse(fh_bh);
|
|
|
|
out_brelse_dir:
|
|
affs_brelse(dir_bh);
|
|
|
|
out_unlock_dir:
|
|
affs_unlock_dir(inode);
|
|
return error;
|
|
}
|