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![Cong Wang](/assets/img/avatar_default.png)
posix_acl_update_mode() could possibly clear 'acl', if so we leak the memory pointed by 'acl'. Save this pointer before calling posix_acl_update_mode() and release the memory if 'acl' really gets cleared. Link: http://lkml.kernel.org/r/1486678332-2430-1-git-send-email-xiyou.wangcong@gmail.com Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Reported-by: Mark Salyzyn <salyzyn@android.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Greg Kurz <groug@kaod.org> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
332 lines
8 KiB
C
332 lines
8 KiB
C
/*
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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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* This program is free software; you can redistribute it and/or modify it
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* under the terms of version 2.1 of the GNU Lesser General Public License
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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*
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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_get_acl(struct p9_fid *fid, 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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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 = posix_acl_from_xattr(&init_user_ns, value, size);
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if (IS_ERR(acl))
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goto err_out;
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}
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} else if (size == -ENODATA || size == 0 ||
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size == -ENOSYS || size == -EOPNOTSUPP) {
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acl = NULL;
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} else
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acl = ERR_PTR(-EIO);
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err_out:
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kfree(value);
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return acl;
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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_acl(struct inode *inode, int type)
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{
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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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/*
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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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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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static int v9fs_xattr_get_acl(const struct xattr_handler *handler,
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struct dentry *dentry, struct inode *inode,
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const char *name, void *buffer, size_t size)
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{
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struct v9fs_session_info *v9ses;
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struct posix_acl *acl;
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int error;
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v9ses = v9fs_dentry2v9ses(dentry);
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/*
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* We allow set/get/list of acl when access=client is not specified
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*/
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if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
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return v9fs_xattr_get(dentry, handler->name, buffer, size);
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acl = v9fs_get_cached_acl(inode, handler->flags);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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if (acl == NULL)
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return -ENODATA;
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error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
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posix_acl_release(acl);
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return error;
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}
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static int v9fs_xattr_set_acl(const struct xattr_handler *handler,
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struct dentry *dentry, struct inode *inode,
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const char *name, const void *value,
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size_t size, int flags)
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{
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int retval;
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struct posix_acl *acl;
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struct v9fs_session_info *v9ses;
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v9ses = v9fs_dentry2v9ses(dentry);
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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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if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
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return v9fs_xattr_set(dentry, handler->name, value, size,
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flags);
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if (S_ISLNK(inode->i_mode))
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return -EOPNOTSUPP;
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if (!inode_owner_or_capable(inode))
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return -EPERM;
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if (value) {
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/* update the cached acl value */
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acl = posix_acl_from_xattr(&init_user_ns, value, size);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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else 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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}
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} else
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acl = NULL;
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switch (handler->flags) {
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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 *old_acl = acl;
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retval = posix_acl_update_mode(inode, &iattr.ia_mode, &acl);
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if (retval)
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goto err_out;
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if (!acl) {
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/*
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* ACL can be represented
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* by the mode bits. So don't
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* update ACL.
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*/
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posix_acl_release(old_acl);
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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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/* FIXME should we update ctime ?
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* What is the following setxattr update the
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* mode ?
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*/
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v9fs_vfs_setattr_dotl(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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default:
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BUG();
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}
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retval = v9fs_xattr_set(dentry, handler->name, value, size, flags);
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if (!retval)
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set_cached_acl(inode, handler->flags, acl);
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err_out:
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posix_acl_release(acl);
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return retval;
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}
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const struct xattr_handler v9fs_xattr_acl_access_handler = {
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.name = XATTR_NAME_POSIX_ACL_ACCESS,
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.flags = ACL_TYPE_ACCESS,
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.get = v9fs_xattr_get_acl,
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.set = v9fs_xattr_set_acl,
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};
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const struct xattr_handler v9fs_xattr_acl_default_handler = {
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.name = XATTR_NAME_POSIX_ACL_DEFAULT,
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.flags = ACL_TYPE_DEFAULT,
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.get = v9fs_xattr_get_acl,
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.set = v9fs_xattr_set_acl,
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};
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