https://github.com/torvalds/linux
Tip revision: 3123109284176b1532874591f7c81f3837bbdc17 authored by Linus Torvalds on 03 April 2022, 21:08:21 UTC
Linux 5.18-rc1
Linux 5.18-rc1
Tip revision: 3123109
dir.c
// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/hpfs/dir.c
*
* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
*
* directory VFS functions
*/
#include <linux/slab.h>
#include "hpfs_fn.h"
static int hpfs_dir_release(struct inode *inode, struct file *filp)
{
hpfs_lock(inode->i_sb);
hpfs_del_pos(inode, &filp->f_pos);
/*hpfs_write_if_changed(inode);*/
hpfs_unlock(inode->i_sb);
return 0;
}
/* This is slow, but it's not used often */
static loff_t hpfs_dir_lseek(struct file *filp, loff_t off, int whence)
{
loff_t new_off = off + (whence == 1 ? filp->f_pos : 0);
loff_t pos;
struct quad_buffer_head qbh;
struct inode *i = file_inode(filp);
struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
struct super_block *s = i->i_sb;
/* Somebody else will have to figure out what to do here */
if (whence == SEEK_DATA || whence == SEEK_HOLE)
return -EINVAL;
inode_lock(i);
hpfs_lock(s);
/*pr_info("dir lseek\n");*/
if (new_off == 0 || new_off == 1 || new_off == 11 || new_off == 12 || new_off == 13) goto ok;
pos = ((loff_t) hpfs_de_as_down_as_possible(s, hpfs_inode->i_dno) << 4) + 1;
while (pos != new_off) {
if (map_pos_dirent(i, &pos, &qbh)) hpfs_brelse4(&qbh);
else goto fail;
if (pos == 12) goto fail;
}
if (unlikely(hpfs_add_pos(i, &filp->f_pos) < 0)) {
hpfs_unlock(s);
inode_unlock(i);
return -ENOMEM;
}
ok:
filp->f_pos = new_off;
hpfs_unlock(s);
inode_unlock(i);
return new_off;
fail:
/*pr_warn("illegal lseek: %016llx\n", new_off);*/
hpfs_unlock(s);
inode_unlock(i);
return -ESPIPE;
}
static int hpfs_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
struct quad_buffer_head qbh;
struct hpfs_dirent *de;
int lc;
loff_t next_pos;
unsigned char *tempname;
int c1, c2 = 0;
int ret = 0;
hpfs_lock(inode->i_sb);
if (hpfs_sb(inode->i_sb)->sb_chk) {
if (hpfs_chk_sectors(inode->i_sb, inode->i_ino, 1, "dir_fnode")) {
ret = -EFSERROR;
goto out;
}
if (hpfs_chk_sectors(inode->i_sb, hpfs_inode->i_dno, 4, "dir_dnode")) {
ret = -EFSERROR;
goto out;
}
}
if (hpfs_sb(inode->i_sb)->sb_chk >= 2) {
struct buffer_head *bh;
struct fnode *fno;
int e = 0;
if (!(fno = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) {
ret = -EIOERROR;
goto out;
}
if (!fnode_is_dir(fno)) {
e = 1;
hpfs_error(inode->i_sb, "not a directory, fnode %08lx",
(unsigned long)inode->i_ino);
}
if (hpfs_inode->i_dno != le32_to_cpu(fno->u.external[0].disk_secno)) {
e = 1;
hpfs_error(inode->i_sb, "corrupted inode: i_dno == %08x, fnode -> dnode == %08x", hpfs_inode->i_dno, le32_to_cpu(fno->u.external[0].disk_secno));
}
brelse(bh);
if (e) {
ret = -EFSERROR;
goto out;
}
}
lc = hpfs_sb(inode->i_sb)->sb_lowercase;
if (ctx->pos == 12) { /* diff -r requires this (note, that diff -r */
ctx->pos = 13; /* also fails on msdos filesystem in 2.0) */
goto out;
}
if (ctx->pos == 13) {
ret = -ENOENT;
goto out;
}
while (1) {
again:
/* This won't work when cycle is longer than number of dirents
accepted by filldir, but what can I do?
maybe killall -9 ls helps */
if (hpfs_sb(inode->i_sb)->sb_chk)
if (hpfs_stop_cycles(inode->i_sb, ctx->pos, &c1, &c2, "hpfs_readdir")) {
ret = -EFSERROR;
goto out;
}
if (ctx->pos == 12)
goto out;
if (ctx->pos == 3 || ctx->pos == 4 || ctx->pos == 5) {
pr_err("pos==%d\n", (int)ctx->pos);
goto out;
}
if (ctx->pos == 0) {
if (!dir_emit_dot(file, ctx))
goto out;
ctx->pos = 11;
}
if (ctx->pos == 11) {
if (!dir_emit(ctx, "..", 2, hpfs_inode->i_parent_dir, DT_DIR))
goto out;
ctx->pos = 1;
}
if (ctx->pos == 1) {
ret = hpfs_add_pos(inode, &file->f_pos);
if (unlikely(ret < 0))
goto out;
ctx->pos = ((loff_t) hpfs_de_as_down_as_possible(inode->i_sb, hpfs_inode->i_dno) << 4) + 1;
}
next_pos = ctx->pos;
if (!(de = map_pos_dirent(inode, &next_pos, &qbh))) {
ctx->pos = next_pos;
ret = -EIOERROR;
goto out;
}
if (de->first || de->last) {
if (hpfs_sb(inode->i_sb)->sb_chk) {
if (de->first && !de->last && (de->namelen != 2
|| de ->name[0] != 1 || de->name[1] != 1))
hpfs_error(inode->i_sb, "hpfs_readdir: bad ^A^A entry; pos = %08lx", (unsigned long)ctx->pos);
if (de->last && (de->namelen != 1 || de ->name[0] != 255))
hpfs_error(inode->i_sb, "hpfs_readdir: bad \\377 entry; pos = %08lx", (unsigned long)ctx->pos);
}
hpfs_brelse4(&qbh);
ctx->pos = next_pos;
goto again;
}
tempname = hpfs_translate_name(inode->i_sb, de->name, de->namelen, lc, de->not_8x3);
if (!dir_emit(ctx, tempname, de->namelen, le32_to_cpu(de->fnode), DT_UNKNOWN)) {
if (tempname != de->name) kfree(tempname);
hpfs_brelse4(&qbh);
goto out;
}
ctx->pos = next_pos;
if (tempname != de->name) kfree(tempname);
hpfs_brelse4(&qbh);
}
out:
hpfs_unlock(inode->i_sb);
return ret;
}
/*
* lookup. Search the specified directory for the specified name, set
* *result to the corresponding inode.
*
* lookup uses the inode number to tell read_inode whether it is reading
* the inode of a directory or a file -- file ino's are odd, directory
* ino's are even. read_inode avoids i/o for file inodes; everything
* needed is up here in the directory. (And file fnodes are out in
* the boondocks.)
*
* - M.P.: this is over, sometimes we've got to read file's fnode for eas
* inode numbers are just fnode sector numbers; iget lock is used
* to tell read_inode to read fnode or not.
*/
struct dentry *hpfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
const unsigned char *name = dentry->d_name.name;
unsigned len = dentry->d_name.len;
struct quad_buffer_head qbh;
struct hpfs_dirent *de;
ino_t ino;
int err;
struct inode *result = NULL;
struct hpfs_inode_info *hpfs_result;
hpfs_lock(dir->i_sb);
if ((err = hpfs_chk_name(name, &len))) {
if (err == -ENAMETOOLONG) {
hpfs_unlock(dir->i_sb);
return ERR_PTR(-ENAMETOOLONG);
}
goto end_add;
}
/*
* '.' and '..' will never be passed here.
*/
de = map_dirent(dir, hpfs_i(dir)->i_dno, name, len, NULL, &qbh);
/*
* This is not really a bailout, just means file not found.
*/
if (!de) goto end;
/*
* Get inode number, what we're after.
*/
ino = le32_to_cpu(de->fnode);
/*
* Go find or make an inode.
*/
result = iget_locked(dir->i_sb, ino);
if (!result) {
hpfs_error(dir->i_sb, "hpfs_lookup: can't get inode");
result = ERR_PTR(-ENOMEM);
goto bail1;
}
if (result->i_state & I_NEW) {
hpfs_init_inode(result);
if (de->directory)
hpfs_read_inode(result);
else if (le32_to_cpu(de->ea_size) && hpfs_sb(dir->i_sb)->sb_eas)
hpfs_read_inode(result);
else {
result->i_mode |= S_IFREG;
result->i_mode &= ~0111;
result->i_op = &hpfs_file_iops;
result->i_fop = &hpfs_file_ops;
set_nlink(result, 1);
}
unlock_new_inode(result);
}
hpfs_result = hpfs_i(result);
if (!de->directory) hpfs_result->i_parent_dir = dir->i_ino;
if (de->has_acl || de->has_xtd_perm) if (!sb_rdonly(dir->i_sb)) {
hpfs_error(result->i_sb, "ACLs or XPERM found. This is probably HPFS386. This driver doesn't support it now. Send me some info on these structures");
iput(result);
result = ERR_PTR(-EINVAL);
goto bail1;
}
/*
* Fill in the info from the directory if this is a newly created
* inode.
*/
if (!result->i_ctime.tv_sec) {
if (!(result->i_ctime.tv_sec = local_to_gmt(dir->i_sb, le32_to_cpu(de->creation_date))))
result->i_ctime.tv_sec = 1;
result->i_ctime.tv_nsec = 0;
result->i_mtime.tv_sec = local_to_gmt(dir->i_sb, le32_to_cpu(de->write_date));
result->i_mtime.tv_nsec = 0;
result->i_atime.tv_sec = local_to_gmt(dir->i_sb, le32_to_cpu(de->read_date));
result->i_atime.tv_nsec = 0;
hpfs_result->i_ea_size = le32_to_cpu(de->ea_size);
if (!hpfs_result->i_ea_mode && de->read_only)
result->i_mode &= ~0222;
if (!de->directory) {
if (result->i_size == -1) {
result->i_size = le32_to_cpu(de->file_size);
result->i_data.a_ops = &hpfs_aops;
hpfs_i(result)->mmu_private = result->i_size;
/*
* i_blocks should count the fnode and any anodes.
* We count 1 for the fnode and don't bother about
* anodes -- the disk heads are on the directory band
* and we want them to stay there.
*/
result->i_blocks = 1 + ((result->i_size + 511) >> 9);
}
}
}
bail1:
hpfs_brelse4(&qbh);
/*
* Made it.
*/
end:
end_add:
hpfs_unlock(dir->i_sb);
return d_splice_alias(result, dentry);
}
const struct file_operations hpfs_dir_ops =
{
.llseek = hpfs_dir_lseek,
.read = generic_read_dir,
.iterate_shared = hpfs_readdir,
.release = hpfs_dir_release,
.fsync = hpfs_file_fsync,
.unlocked_ioctl = hpfs_ioctl,
.compat_ioctl = compat_ptr_ioctl,
};