mirror of
https://github.com/torvalds/linux
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01beba7957
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>
346 lines
7.8 KiB
C
346 lines
7.8 KiB
C
// SPDX-License-Identifier: LGPL-2.1
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/*
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* Copyright IBM Corporation, 2010
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* Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
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*/
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <net/9p/9p.h>
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#include <net/9p/client.h>
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/posix_acl_xattr.h>
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#include "xattr.h"
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#include "acl.h"
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#include "v9fs.h"
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#include "v9fs_vfs.h"
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#include "fid.h"
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static struct posix_acl *v9fs_fid_get_acl(struct p9_fid *fid, const char *name)
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{
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ssize_t size;
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void *value = NULL;
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struct posix_acl *acl = NULL;
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size = v9fs_fid_xattr_get(fid, name, NULL, 0);
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if (size < 0)
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return ERR_PTR(size);
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if (size == 0)
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return ERR_PTR(-ENODATA);
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value = kzalloc(size, GFP_NOFS);
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if (!value)
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return ERR_PTR(-ENOMEM);
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size = v9fs_fid_xattr_get(fid, name, value, size);
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if (size < 0)
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acl = ERR_PTR(size);
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else if (size == 0)
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acl = ERR_PTR(-ENODATA);
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else
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acl = posix_acl_from_xattr(&init_user_ns, value, size);
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kfree(value);
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return acl;
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}
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static struct posix_acl *v9fs_acl_get(struct dentry *dentry, const char *name)
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{
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struct p9_fid *fid;
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struct posix_acl *acl = NULL;
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fid = v9fs_fid_lookup(dentry);
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if (IS_ERR(fid))
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return ERR_CAST(fid);
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acl = v9fs_fid_get_acl(fid, name);
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p9_fid_put(fid);
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return acl;
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}
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static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, const char *name)
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{
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int retval;
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struct posix_acl *acl = NULL;
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acl = v9fs_fid_get_acl(fid, name);
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if (!IS_ERR(acl))
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return acl;
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retval = PTR_ERR(acl);
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if (retval == -ENODATA || retval == -ENOSYS || retval == -EOPNOTSUPP)
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return NULL;
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/* map everything else to -EIO */
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return ERR_PTR(-EIO);
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}
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int v9fs_get_acl(struct inode *inode, struct p9_fid *fid)
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{
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int retval = 0;
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struct posix_acl *pacl, *dacl;
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struct v9fs_session_info *v9ses;
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v9ses = v9fs_inode2v9ses(inode);
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if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
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((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
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set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL);
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set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
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return 0;
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}
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/* get the default/access acl values and cache them */
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dacl = __v9fs_get_acl(fid, XATTR_NAME_POSIX_ACL_DEFAULT);
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pacl = __v9fs_get_acl(fid, XATTR_NAME_POSIX_ACL_ACCESS);
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if (!IS_ERR(dacl) && !IS_ERR(pacl)) {
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set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);
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set_cached_acl(inode, ACL_TYPE_ACCESS, pacl);
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} else
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retval = -EIO;
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if (!IS_ERR(dacl))
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posix_acl_release(dacl);
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if (!IS_ERR(pacl))
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posix_acl_release(pacl);
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return retval;
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}
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static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type)
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{
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struct posix_acl *acl;
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/*
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* 9p Always cache the acl value when
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* instantiating the inode (v9fs_inode_from_fid)
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*/
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acl = get_cached_acl(inode, type);
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BUG_ON(is_uncached_acl(acl));
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return acl;
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}
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struct posix_acl *v9fs_iop_get_inode_acl(struct inode *inode, int type, bool rcu)
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{
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struct v9fs_session_info *v9ses;
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if (rcu)
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return ERR_PTR(-ECHILD);
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v9ses = v9fs_inode2v9ses(inode);
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if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
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((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
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/*
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* On access = client and acl = on mode get the acl
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* values from the server
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*/
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return NULL;
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}
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return v9fs_get_cached_acl(inode, type);
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}
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struct posix_acl *v9fs_iop_get_acl(struct mnt_idmap *idmap,
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struct dentry *dentry, int type)
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{
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struct v9fs_session_info *v9ses;
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v9ses = v9fs_dentry2v9ses(dentry);
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/* We allow set/get/list of acl when access=client is not specified. */
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if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
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return v9fs_acl_get(dentry, posix_acl_xattr_name(type));
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return v9fs_get_cached_acl(d_inode(dentry), type);
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}
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int v9fs_iop_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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int retval;
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size_t size = 0;
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void *value = NULL;
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const char *acl_name;
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struct v9fs_session_info *v9ses;
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struct inode *inode = d_inode(dentry);
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if (acl) {
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retval = posix_acl_valid(inode->i_sb->s_user_ns, acl);
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if (retval)
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goto err_out;
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size = posix_acl_xattr_size(acl->a_count);
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value = kzalloc(size, GFP_NOFS);
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if (!value) {
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retval = -ENOMEM;
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goto err_out;
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}
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retval = posix_acl_to_xattr(&init_user_ns, acl, value, size);
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if (retval < 0)
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goto err_out;
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}
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/*
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* set the attribute on the remote. Without even looking at the
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* xattr value. We leave it to the server to validate
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*/
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acl_name = posix_acl_xattr_name(type);
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v9ses = v9fs_dentry2v9ses(dentry);
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if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) {
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retval = v9fs_xattr_set(dentry, acl_name, value, size, 0);
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goto err_out;
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}
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if (S_ISLNK(inode->i_mode)) {
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retval = -EOPNOTSUPP;
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goto err_out;
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}
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if (!inode_owner_or_capable(&nop_mnt_idmap, inode)) {
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retval = -EPERM;
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goto err_out;
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}
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switch (type) {
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case ACL_TYPE_ACCESS:
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if (acl) {
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struct iattr iattr = {};
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struct posix_acl *acl_mode = acl;
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retval = posix_acl_update_mode(&nop_mnt_idmap, inode,
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&iattr.ia_mode,
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&acl_mode);
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if (retval)
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goto err_out;
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if (!acl_mode) {
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/*
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* ACL can be represented by the mode bits.
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* So don't update ACL below.
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*/
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kfree(value);
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value = NULL;
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size = 0;
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}
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iattr.ia_valid = ATTR_MODE;
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/*
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* FIXME should we update ctime ?
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* What is the following setxattr update the mode ?
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*/
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v9fs_vfs_setattr_dotl(&nop_mnt_idmap, dentry, &iattr);
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}
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break;
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case ACL_TYPE_DEFAULT:
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if (!S_ISDIR(inode->i_mode)) {
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retval = acl ? -EINVAL : 0;
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goto err_out;
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}
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break;
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}
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retval = v9fs_xattr_set(dentry, acl_name, value, size, 0);
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if (!retval)
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set_cached_acl(inode, type, acl);
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err_out:
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kfree(value);
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return retval;
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}
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static int v9fs_set_acl(struct p9_fid *fid, int type, struct posix_acl *acl)
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{
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int retval;
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char *name;
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size_t size;
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void *buffer;
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if (!acl)
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return 0;
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/* Set a setxattr request to server */
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size = posix_acl_xattr_size(acl->a_count);
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buffer = kmalloc(size, GFP_KERNEL);
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if (!buffer)
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return -ENOMEM;
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retval = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
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if (retval < 0)
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goto err_free_out;
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switch (type) {
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case ACL_TYPE_ACCESS:
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name = XATTR_NAME_POSIX_ACL_ACCESS;
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break;
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case ACL_TYPE_DEFAULT:
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name = XATTR_NAME_POSIX_ACL_DEFAULT;
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break;
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default:
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BUG();
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}
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retval = v9fs_fid_xattr_set(fid, name, buffer, size, 0);
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err_free_out:
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kfree(buffer);
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return retval;
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}
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int v9fs_acl_chmod(struct inode *inode, struct p9_fid *fid)
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{
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int retval = 0;
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struct posix_acl *acl;
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if (S_ISLNK(inode->i_mode))
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return -EOPNOTSUPP;
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acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
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if (acl) {
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retval = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
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if (retval)
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return retval;
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set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
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retval = v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl);
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posix_acl_release(acl);
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}
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return retval;
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}
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int v9fs_set_create_acl(struct inode *inode, struct p9_fid *fid,
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struct posix_acl *dacl, struct posix_acl *acl)
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{
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set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);
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set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
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v9fs_set_acl(fid, ACL_TYPE_DEFAULT, dacl);
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v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl);
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return 0;
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}
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void v9fs_put_acl(struct posix_acl *dacl,
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struct posix_acl *acl)
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{
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posix_acl_release(dacl);
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posix_acl_release(acl);
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}
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int v9fs_acl_mode(struct inode *dir, umode_t *modep,
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struct posix_acl **dpacl, struct posix_acl **pacl)
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{
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int retval = 0;
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umode_t mode = *modep;
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struct posix_acl *acl = NULL;
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if (!S_ISLNK(mode)) {
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acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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if (!acl)
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mode &= ~current_umask();
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}
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if (acl) {
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if (S_ISDIR(mode))
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*dpacl = posix_acl_dup(acl);
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retval = __posix_acl_create(&acl, GFP_NOFS, &mode);
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if (retval < 0)
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return retval;
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if (retval > 0)
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*pacl = acl;
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else
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posix_acl_release(acl);
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}
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*modep = mode;
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return 0;
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}
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