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700b794052
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>
156 lines
3.3 KiB
C
156 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
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* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
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*/
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/completion.h>
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#include <linux/buffer_head.h>
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#include <linux/xattr.h>
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#include <linux/posix_acl.h>
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#include <linux/posix_acl_xattr.h>
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#include <linux/gfs2_ondisk.h>
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#include "gfs2.h"
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#include "incore.h"
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#include "acl.h"
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#include "xattr.h"
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#include "glock.h"
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#include "inode.h"
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#include "meta_io.h"
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#include "quota.h"
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#include "rgrp.h"
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#include "trans.h"
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#include "util.h"
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static const char *gfs2_acl_name(int type)
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{
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switch (type) {
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case ACL_TYPE_ACCESS:
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return XATTR_POSIX_ACL_ACCESS;
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case ACL_TYPE_DEFAULT:
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return XATTR_POSIX_ACL_DEFAULT;
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}
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return NULL;
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}
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static struct posix_acl *__gfs2_get_acl(struct inode *inode, int type)
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{
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struct gfs2_inode *ip = GFS2_I(inode);
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struct posix_acl *acl;
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const char *name;
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char *data;
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int len;
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if (!ip->i_eattr)
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return NULL;
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name = gfs2_acl_name(type);
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len = gfs2_xattr_acl_get(ip, name, &data);
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if (len <= 0)
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return ERR_PTR(len);
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acl = posix_acl_from_xattr(&init_user_ns, data, len);
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kfree(data);
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return acl;
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}
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struct posix_acl *gfs2_get_acl(struct inode *inode, int type, bool rcu)
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{
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struct gfs2_inode *ip = GFS2_I(inode);
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struct gfs2_holder gh;
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bool need_unlock = false;
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struct posix_acl *acl;
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if (rcu)
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return ERR_PTR(-ECHILD);
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if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
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int ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
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LM_FLAG_ANY, &gh);
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if (ret)
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return ERR_PTR(ret);
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need_unlock = true;
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}
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acl = __gfs2_get_acl(inode, type);
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if (need_unlock)
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gfs2_glock_dq_uninit(&gh);
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return acl;
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}
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int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
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{
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int error;
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size_t len;
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char *data;
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const char *name = gfs2_acl_name(type);
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if (acl) {
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len = posix_acl_xattr_size(acl->a_count);
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data = kmalloc(len, GFP_NOFS);
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if (data == NULL)
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return -ENOMEM;
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error = posix_acl_to_xattr(&init_user_ns, acl, data, len);
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if (error < 0)
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goto out;
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} else {
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data = NULL;
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len = 0;
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}
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error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
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if (error)
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goto out;
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set_cached_acl(inode, type, acl);
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out:
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kfree(data);
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return error;
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}
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int gfs2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
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struct posix_acl *acl, int type)
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{
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struct inode *inode = d_inode(dentry);
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struct gfs2_inode *ip = GFS2_I(inode);
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struct gfs2_holder gh;
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bool need_unlock = false;
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int ret;
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umode_t mode;
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if (acl && acl->a_count > GFS2_ACL_MAX_ENTRIES(GFS2_SB(inode)))
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return -E2BIG;
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ret = gfs2_qa_get(ip);
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if (ret)
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return ret;
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if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
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ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
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if (ret)
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goto out;
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need_unlock = true;
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}
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mode = inode->i_mode;
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if (type == ACL_TYPE_ACCESS && acl) {
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ret = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode, &acl);
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if (ret)
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goto unlock;
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}
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ret = __gfs2_set_acl(inode, acl, type);
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if (!ret && mode != inode->i_mode) {
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inode->i_ctime = current_time(inode);
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inode->i_mode = mode;
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mark_inode_dirty(inode);
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}
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unlock:
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if (need_unlock)
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gfs2_glock_dq_uninit(&gh);
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out:
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gfs2_qa_put(ip);
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return ret;
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}
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