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linux/fs/hfsplus/dir.c
Christian Brauner e18275ae55
fs: port ->rename() to pass mnt_idmap 
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:26 +01:00

584 lines
14 KiB
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// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/hfsplus/dir.c
*
* Copyright (C) 2001
* Brad Boyer (flar@allandria.com)
* (C) 2003 Ardis Technologies <roman@ardistech.com>
*
* Handling of directories
*/
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/nls.h>
#include "hfsplus_fs.h"
#include "hfsplus_raw.h"
#include "xattr.h"
static inline void hfsplus_instantiate(struct dentry *dentry,
struct inode *inode, u32 cnid)
{
dentry->d_fsdata = (void *)(unsigned long)cnid;
d_instantiate(dentry, inode);
}
/* Find the entry inside dir named dentry->d_name */
static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct inode *inode = NULL;
struct hfs_find_data fd;
struct super_block *sb;
hfsplus_cat_entry entry;
int err;
u32 cnid, linkid = 0;
u16 type;
sb = dir->i_sb;
dentry->d_fsdata = NULL;
err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
if (err)
return ERR_PTR(err);
err = hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino,
&dentry->d_name);
if (unlikely(err < 0))
goto fail;
again:
err = hfs_brec_read(&fd, &entry, sizeof(entry));
if (err) {
if (err == -ENOENT) {
hfs_find_exit(&fd);
/* No such entry */
inode = NULL;
goto out;
}
goto fail;
}
type = be16_to_cpu(entry.type);
if (type == HFSPLUS_FOLDER) {
if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
err = -EIO;
goto fail;
}
cnid = be32_to_cpu(entry.folder.id);
dentry->d_fsdata = (void *)(unsigned long)cnid;
} else if (type == HFSPLUS_FILE) {
if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
err = -EIO;
goto fail;
}
cnid = be32_to_cpu(entry.file.id);
if (entry.file.user_info.fdType ==
cpu_to_be32(HFSP_HARDLINK_TYPE) &&
entry.file.user_info.fdCreator ==
cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
HFSPLUS_SB(sb)->hidden_dir &&
(entry.file.create_date ==
HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
create_date ||
entry.file.create_date ==
HFSPLUS_I(d_inode(sb->s_root))->
create_date)) {
struct qstr str;
char name[32];
if (dentry->d_fsdata) {
/*
* We found a link pointing to another link,
* so ignore it and treat it as regular file.
*/
cnid = (unsigned long)dentry->d_fsdata;
linkid = 0;
} else {
dentry->d_fsdata = (void *)(unsigned long)cnid;
linkid =
be32_to_cpu(entry.file.permissions.dev);
str.len = sprintf(name, "iNode%d", linkid);
str.name = name;
err = hfsplus_cat_build_key(sb, fd.search_key,
HFSPLUS_SB(sb)->hidden_dir->i_ino,
&str);
if (unlikely(err < 0))
goto fail;
goto again;
}
} else if (!dentry->d_fsdata)
dentry->d_fsdata = (void *)(unsigned long)cnid;
} else {
pr_err("invalid catalog entry type in lookup\n");
err = -EIO;
goto fail;
}
hfs_find_exit(&fd);
inode = hfsplus_iget(dir->i_sb, cnid);
if (IS_ERR(inode))
return ERR_CAST(inode);
if (S_ISREG(inode->i_mode))
HFSPLUS_I(inode)->linkid = linkid;
out:
return d_splice_alias(inode, dentry);
fail:
hfs_find_exit(&fd);
return ERR_PTR(err);
}
static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct super_block *sb = inode->i_sb;
int len, err;
char *strbuf;
hfsplus_cat_entry entry;
struct hfs_find_data fd;
struct hfsplus_readdir_data *rd;
u16 type;
if (file->f_pos >= inode->i_size)
return 0;
err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
if (err)
return err;
strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
if (!strbuf) {
err = -ENOMEM;
goto out;
}
hfsplus_cat_build_key_with_cnid(sb, fd.search_key, inode->i_ino);
err = hfs_brec_find(&fd, hfs_find_rec_by_key);
if (err)
goto out;
if (ctx->pos == 0) {
/* This is completely artificial... */
if (!dir_emit_dot(file, ctx))
goto out;
ctx->pos = 1;
}
if (ctx->pos == 1) {
if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
err = -EIO;
goto out;
}
hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
fd.entrylength);
if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
pr_err("bad catalog folder thread\n");
err = -EIO;
goto out;
}
if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
pr_err("truncated catalog thread\n");
err = -EIO;
goto out;
}
if (!dir_emit(ctx, "..", 2,
be32_to_cpu(entry.thread.parentID), DT_DIR))
goto out;
ctx->pos = 2;
}
if (ctx->pos >= inode->i_size)
goto out;
err = hfs_brec_goto(&fd, ctx->pos - 1);
if (err)
goto out;
for (;;) {
if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
pr_err("walked past end of dir\n");
err = -EIO;
goto out;
}
if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
err = -EIO;
goto out;
}
hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
fd.entrylength);
type = be16_to_cpu(entry.type);
len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
if (err)
goto out;
if (type == HFSPLUS_FOLDER) {
if (fd.entrylength <
sizeof(struct hfsplus_cat_folder)) {
pr_err("small dir entry\n");
err = -EIO;
goto out;
}
if (HFSPLUS_SB(sb)->hidden_dir &&
HFSPLUS_SB(sb)->hidden_dir->i_ino ==
be32_to_cpu(entry.folder.id))
goto next;
if (!dir_emit(ctx, strbuf, len,
be32_to_cpu(entry.folder.id), DT_DIR))
break;
} else if (type == HFSPLUS_FILE) {
u16 mode;
unsigned type = DT_UNKNOWN;
if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
pr_err("small file entry\n");
err = -EIO;
goto out;
}
mode = be16_to_cpu(entry.file.permissions.mode);
if (S_ISREG(mode))
type = DT_REG;
else if (S_ISLNK(mode))
type = DT_LNK;
else if (S_ISFIFO(mode))
type = DT_FIFO;
else if (S_ISCHR(mode))
type = DT_CHR;
else if (S_ISBLK(mode))
type = DT_BLK;
else if (S_ISSOCK(mode))
type = DT_SOCK;
if (!dir_emit(ctx, strbuf, len,
be32_to_cpu(entry.file.id), type))
break;
} else {
pr_err("bad catalog entry type\n");
err = -EIO;
goto out;
}
next:
ctx->pos++;
if (ctx->pos >= inode->i_size)
goto out;
err = hfs_brec_goto(&fd, 1);
if (err)
goto out;
}
rd = file->private_data;
if (!rd) {
rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
if (!rd) {
err = -ENOMEM;
goto out;
}
file->private_data = rd;
rd->file = file;
spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
}
/*
* Can be done after the list insertion; exclusion with
* hfsplus_delete_cat() is provided by directory lock.
*/
memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
out:
kfree(strbuf);
hfs_find_exit(&fd);
return err;
}
static int hfsplus_dir_release(struct inode *inode, struct file *file)
{
struct hfsplus_readdir_data *rd = file->private_data;
if (rd) {
spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
list_del(&rd->list);
spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
kfree(rd);
}
return 0;
}
static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
struct dentry *dst_dentry)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
struct inode *inode = d_inode(src_dentry);
struct inode *src_dir = d_inode(src_dentry->d_parent);
struct qstr str;
char name[32];
u32 cnid, id;
int res;
if (HFSPLUS_IS_RSRC(inode))
return -EPERM;
if (!S_ISREG(inode->i_mode))
return -EPERM;
mutex_lock(&sbi->vh_mutex);
if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
for (;;) {
get_random_bytes(&id, sizeof(cnid));
id &= 0x3fffffff;
str.name = name;
str.len = sprintf(name, "iNode%d", id);
res = hfsplus_rename_cat(inode->i_ino,
src_dir, &src_dentry->d_name,
sbi->hidden_dir, &str);
if (!res)
break;
if (res != -EEXIST)
goto out;
}
HFSPLUS_I(inode)->linkid = id;
cnid = sbi->next_cnid++;
src_dentry->d_fsdata = (void *)(unsigned long)cnid;
res = hfsplus_create_cat(cnid, src_dir,
&src_dentry->d_name, inode);
if (res)
/* panic? */
goto out;
sbi->file_count++;
}
cnid = sbi->next_cnid++;
res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
if (res)
goto out;
inc_nlink(inode);
hfsplus_instantiate(dst_dentry, inode, cnid);
ihold(inode);
inode->i_ctime = current_time(inode);
mark_inode_dirty(inode);
sbi->file_count++;
hfsplus_mark_mdb_dirty(dst_dir->i_sb);
out:
mutex_unlock(&sbi->vh_mutex);
return res;
}
static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
struct inode *inode = d_inode(dentry);
struct qstr str;
char name[32];
u32 cnid;
int res;
if (HFSPLUS_IS_RSRC(inode))
return -EPERM;
mutex_lock(&sbi->vh_mutex);
cnid = (u32)(unsigned long)dentry->d_fsdata;
if (inode->i_ino == cnid &&
atomic_read(&HFSPLUS_I(inode)->opencnt)) {
str.name = name;
str.len = sprintf(name, "temp%lu", inode->i_ino);
res = hfsplus_rename_cat(inode->i_ino,
dir, &dentry->d_name,
sbi->hidden_dir, &str);
if (!res) {
inode->i_flags |= S_DEAD;
drop_nlink(inode);
}
goto out;
}
res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
if (res)
goto out;
if (inode->i_nlink > 0)
drop_nlink(inode);
if (inode->i_ino == cnid)
clear_nlink(inode);
if (!inode->i_nlink) {
if (inode->i_ino != cnid) {
sbi->file_count--;
if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
res = hfsplus_delete_cat(inode->i_ino,
sbi->hidden_dir,
NULL);
if (!res)
hfsplus_delete_inode(inode);
} else
inode->i_flags |= S_DEAD;
} else
hfsplus_delete_inode(inode);
} else
sbi->file_count--;
inode->i_ctime = current_time(inode);
mark_inode_dirty(inode);
out:
mutex_unlock(&sbi->vh_mutex);
return res;
}
static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
struct inode *inode = d_inode(dentry);
int res;
if (inode->i_size != 2)
return -ENOTEMPTY;
mutex_lock(&sbi->vh_mutex);
res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
if (res)
goto out;
clear_nlink(inode);
inode->i_ctime = current_time(inode);
hfsplus_delete_inode(inode);
mark_inode_dirty(inode);
out:
mutex_unlock(&sbi->vh_mutex);
return res;
}
static int hfsplus_symlink(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, const char *symname)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
struct inode *inode;
int res = -ENOMEM;
mutex_lock(&sbi->vh_mutex);
inode = hfsplus_new_inode(dir->i_sb, dir, S_IFLNK | S_IRWXUGO);
if (!inode)
goto out;
res = page_symlink(inode, symname, strlen(symname) + 1);
if (res)
goto out_err;
res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
if (res)
goto out_err;
res = hfsplus_init_security(inode, dir, &dentry->d_name);
if (res == -EOPNOTSUPP)
res = 0; /* Operation is not supported. */
else if (res) {
/* Try to delete anyway without error analysis. */
hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
goto out_err;
}
hfsplus_instantiate(dentry, inode, inode->i_ino);
mark_inode_dirty(inode);
goto out;
out_err:
clear_nlink(inode);
hfsplus_delete_inode(inode);
iput(inode);
out:
mutex_unlock(&sbi->vh_mutex);
return res;
}
static int hfsplus_mknod(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, dev_t rdev)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
struct inode *inode;
int res = -ENOMEM;
mutex_lock(&sbi->vh_mutex);
inode = hfsplus_new_inode(dir->i_sb, dir, mode);
if (!inode)
goto out;
if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
init_special_inode(inode, mode, rdev);
res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
if (res)
goto failed_mknod;
res = hfsplus_init_security(inode, dir, &dentry->d_name);
if (res == -EOPNOTSUPP)
res = 0; /* Operation is not supported. */
else if (res) {
/* Try to delete anyway without error analysis. */
hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
goto failed_mknod;
}
hfsplus_instantiate(dentry, inode, inode->i_ino);
mark_inode_dirty(inode);
goto out;
failed_mknod:
clear_nlink(inode);
hfsplus_delete_inode(inode);
iput(inode);
out:
mutex_unlock(&sbi->vh_mutex);
return res;
}
static int hfsplus_create(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, bool excl)
{
return hfsplus_mknod(&nop_mnt_idmap, dir, dentry, mode, 0);
}
static int hfsplus_mkdir(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
return hfsplus_mknod(&nop_mnt_idmap, dir, dentry, mode | S_IFDIR, 0);
}
static int hfsplus_rename(struct mnt_idmap *idmap,
struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
int res;
if (flags & ~RENAME_NOREPLACE)
return -EINVAL;
/* Unlink destination if it already exists */
if (d_really_is_positive(new_dentry)) {
if (d_is_dir(new_dentry))
res = hfsplus_rmdir(new_dir, new_dentry);
else
res = hfsplus_unlink(new_dir, new_dentry);
if (res)
return res;
}
res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
old_dir, &old_dentry->d_name,
new_dir, &new_dentry->d_name);
if (!res)
new_dentry->d_fsdata = old_dentry->d_fsdata;
return res;
}
const struct inode_operations hfsplus_dir_inode_operations = {
.lookup = hfsplus_lookup,
.create = hfsplus_create,
.link = hfsplus_link,
.unlink = hfsplus_unlink,
.mkdir = hfsplus_mkdir,
.rmdir = hfsplus_rmdir,
.symlink = hfsplus_symlink,
.mknod = hfsplus_mknod,
.rename = hfsplus_rename,
.getattr = hfsplus_getattr,
.listxattr = hfsplus_listxattr,
.fileattr_get = hfsplus_fileattr_get,
.fileattr_set = hfsplus_fileattr_set,
};
const struct file_operations hfsplus_dir_operations = {
.fsync = hfsplus_file_fsync,
.read = generic_read_dir,
.iterate_shared = hfsplus_readdir,
.unlocked_ioctl = hfsplus_ioctl,
.llseek = generic_file_llseek,
.release = hfsplus_dir_release,
};
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