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![Al Viro](/assets/img/avatar_default.png)
... so that &inode->i_mode could be passed to it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
184 lines
3.8 KiB
C
184 lines
3.8 KiB
C
/*
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* (C) 2005 Andreas Gruenbacher <agruen@suse.de>
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*
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* This file is released under the GPL.
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*
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* Generic ACL support for in-memory filesystems.
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*/
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#include <linux/sched.h>
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#include <linux/gfp.h>
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#include <linux/fs.h>
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#include <linux/generic_acl.h>
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#include <linux/posix_acl.h>
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#include <linux/posix_acl_xattr.h>
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static size_t
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generic_acl_list(struct dentry *dentry, char *list, size_t list_size,
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const char *name, size_t name_len, int type)
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{
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struct posix_acl *acl;
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const char *xname;
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size_t size;
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acl = get_cached_acl(dentry->d_inode, type);
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if (!acl)
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return 0;
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posix_acl_release(acl);
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switch (type) {
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case ACL_TYPE_ACCESS:
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xname = POSIX_ACL_XATTR_ACCESS;
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break;
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case ACL_TYPE_DEFAULT:
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xname = POSIX_ACL_XATTR_DEFAULT;
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break;
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default:
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return 0;
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}
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size = strlen(xname) + 1;
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if (list && size <= list_size)
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memcpy(list, xname, size);
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return size;
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}
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static int
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generic_acl_get(struct dentry *dentry, const char *name, void *buffer,
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size_t size, int type)
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{
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struct posix_acl *acl;
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int error;
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if (strcmp(name, "") != 0)
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return -EINVAL;
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acl = get_cached_acl(dentry->d_inode, type);
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if (!acl)
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return -ENODATA;
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error = posix_acl_to_xattr(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
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generic_acl_set(struct dentry *dentry, const char *name, const void *value,
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size_t size, int flags, int type)
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{
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struct inode *inode = dentry->d_inode;
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struct posix_acl *acl = NULL;
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int error;
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if (strcmp(name, "") != 0)
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return -EINVAL;
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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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acl = posix_acl_from_xattr(value, size);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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}
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if (acl) {
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error = posix_acl_valid(acl);
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if (error)
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goto failed;
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switch (type) {
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case ACL_TYPE_ACCESS:
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error = posix_acl_equiv_mode(acl, &inode->i_mode);
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if (error < 0)
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goto failed;
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inode->i_ctime = CURRENT_TIME;
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if (error == 0) {
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posix_acl_release(acl);
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acl = NULL;
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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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error = -EINVAL;
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goto failed;
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}
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break;
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}
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}
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set_cached_acl(inode, type, acl);
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error = 0;
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failed:
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posix_acl_release(acl);
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return error;
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}
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/**
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* generic_acl_init - Take care of acl inheritance at @inode create time
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*
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* Files created inside a directory with a default ACL inherit the
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* directory's default ACL.
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*/
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int
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generic_acl_init(struct inode *inode, struct inode *dir)
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{
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struct posix_acl *acl = NULL;
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int error;
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if (!S_ISLNK(inode->i_mode))
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acl = get_cached_acl(dir, ACL_TYPE_DEFAULT);
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if (acl) {
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if (S_ISDIR(inode->i_mode))
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set_cached_acl(inode, ACL_TYPE_DEFAULT, acl);
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error = posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode);
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if (error < 0)
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return error;
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if (error > 0)
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set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
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} else {
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inode->i_mode &= ~current_umask();
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}
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error = 0;
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posix_acl_release(acl);
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return error;
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}
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/**
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* generic_acl_chmod - change the access acl of @inode upon chmod()
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*
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* A chmod also changes the permissions of the owner, group/mask, and
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* other ACL entries.
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*/
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int
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generic_acl_chmod(struct inode *inode)
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{
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struct posix_acl *acl;
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int error = 0;
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if (S_ISLNK(inode->i_mode))
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return -EOPNOTSUPP;
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acl = get_cached_acl(inode, ACL_TYPE_ACCESS);
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if (acl) {
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error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
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if (error)
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return error;
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set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
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posix_acl_release(acl);
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}
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return error;
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}
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const struct xattr_handler generic_acl_access_handler = {
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.prefix = POSIX_ACL_XATTR_ACCESS,
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.flags = ACL_TYPE_ACCESS,
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.list = generic_acl_list,
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.get = generic_acl_get,
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.set = generic_acl_set,
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};
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const struct xattr_handler generic_acl_default_handler = {
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.prefix = POSIX_ACL_XATTR_DEFAULT,
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.flags = ACL_TYPE_DEFAULT,
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.list = generic_acl_list,
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.get = generic_acl_get,
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.set = generic_acl_set,
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};
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