--- /dev/null
+/*
+ * fs/f2fs/acl.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/acl.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/f2fs_fs.h>
+#include "f2fs.h"
+#include "xattr.h"
+#include "acl.h"
+
+static inline size_t f2fs_acl_size(int count)
+{
+ if (count <= 4) {
+ return sizeof(struct f2fs_acl_header) +
+ count * sizeof(struct f2fs_acl_entry_short);
+ } else {
+ return sizeof(struct f2fs_acl_header) +
+ 4 * sizeof(struct f2fs_acl_entry_short) +
+ (count - 4) * sizeof(struct f2fs_acl_entry);
+ }
+}
+
+static inline int f2fs_acl_count(size_t size)
+{
+ ssize_t s;
+ size -= sizeof(struct f2fs_acl_header);
+ s = size - 4 * sizeof(struct f2fs_acl_entry_short);
+ if (s < 0) {
+ if (size % sizeof(struct f2fs_acl_entry_short))
+ return -1;
+ return size / sizeof(struct f2fs_acl_entry_short);
+ } else {
+ if (s % sizeof(struct f2fs_acl_entry))
+ return -1;
+ return s / sizeof(struct f2fs_acl_entry) + 4;
+ }
+}
+
+static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
+{
+ int i, count;
+ struct posix_acl *acl;
+ struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
+ struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
+ const char *end = value + size;
+
+ if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
+ return ERR_PTR(-EINVAL);
+
+ count = f2fs_acl_count(size);
+ if (count < 0)
+ return ERR_PTR(-EINVAL);
+ if (count == 0)
+ return NULL;
+
+ acl = posix_acl_alloc(count, GFP_NOFS);
+ if (!acl)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < count; i++) {
+
+ if ((char *)entry > end)
+ goto fail;
+
+ acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag);
+ acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);
+
+ switch (acl->a_entries[i].e_tag) {
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ entry = (struct f2fs_acl_entry *)((char *)entry +
+ sizeof(struct f2fs_acl_entry_short));
+ break;
+
+ case ACL_USER:
+ acl->a_entries[i].e_uid =
+ make_kuid(&init_user_ns,
+ le32_to_cpu(entry->e_id));
+ entry = (struct f2fs_acl_entry *)((char *)entry +
+ sizeof(struct f2fs_acl_entry));
+ break;
+ case ACL_GROUP:
+ acl->a_entries[i].e_gid =
+ make_kgid(&init_user_ns,
+ le32_to_cpu(entry->e_id));
+ entry = (struct f2fs_acl_entry *)((char *)entry +
+ sizeof(struct f2fs_acl_entry));
+ break;
+ default:
+ goto fail;
+ }
+ }
+ if ((char *)entry != end)
+ goto fail;
+ return acl;
+fail:
+ posix_acl_release(acl);
+ return ERR_PTR(-EINVAL);
+}
+
+static void *f2fs_acl_to_disk(const struct posix_acl *acl, size_t *size)
+{
+ struct f2fs_acl_header *f2fs_acl;
+ struct f2fs_acl_entry *entry;
+ int i;
+
+ f2fs_acl = kmalloc(sizeof(struct f2fs_acl_header) + acl->a_count *
+ sizeof(struct f2fs_acl_entry), GFP_NOFS);
+ if (!f2fs_acl)
+ return ERR_PTR(-ENOMEM);
+
+ f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
+ entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);
+
+ for (i = 0; i < acl->a_count; i++) {
+
+ entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag);
+ entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);
+
+ switch (acl->a_entries[i].e_tag) {
+ case ACL_USER:
+ entry->e_id = cpu_to_le32(
+ from_kuid(&init_user_ns,
+ acl->a_entries[i].e_uid));
+ entry = (struct f2fs_acl_entry *)((char *)entry +
+ sizeof(struct f2fs_acl_entry));
+ break;
+ case ACL_GROUP:
+ entry->e_id = cpu_to_le32(
+ from_kgid(&init_user_ns,
+ acl->a_entries[i].e_gid));
+ entry = (struct f2fs_acl_entry *)((char *)entry +
+ sizeof(struct f2fs_acl_entry));
+ break;
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ entry = (struct f2fs_acl_entry *)((char *)entry +
+ sizeof(struct f2fs_acl_entry_short));
+ break;
+ default:
+ goto fail;
+ }
+ }
+ *size = f2fs_acl_size(acl->a_count);
+ return (void *)f2fs_acl;
+
+fail:
+ kfree(f2fs_acl);
+ return ERR_PTR(-EINVAL);
+}
+
+static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type,
+ struct page *dpage)
+{
+ int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+ void *value = NULL;
+ struct posix_acl *acl;
+ int retval;
+
+ if (type == ACL_TYPE_ACCESS)
+ name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
+
+ retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage);
+ if (retval > 0) {
+ value = kmalloc(retval, GFP_F2FS_ZERO);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ retval = f2fs_getxattr(inode, name_index, "", value,
+ retval, dpage);
+ }
+
+ if (retval > 0)
+ acl = f2fs_acl_from_disk(value, retval);
+ else if (retval == -ENODATA)
+ acl = NULL;
+ else
+ acl = ERR_PTR(retval);
+ kfree(value);
+
+ if (!IS_ERR(acl))
+ set_cached_acl(inode, type, acl);
+
+ return acl;
+}
+
+struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
+{
+ return __f2fs_get_acl(inode, type, NULL);
+}
+
+static int __f2fs_set_acl(struct inode *inode, int type,
+ struct posix_acl *acl, struct page *ipage)
+{
+ struct f2fs_inode_info *fi = F2FS_I(inode);
+ int name_index;
+ void *value = NULL;
+ size_t size = 0;
+ int error;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
+ if (acl) {
+ error = posix_acl_equiv_mode(acl, &inode->i_mode);
+ if (error < 0)
+ return error;
+ set_acl_inode(fi, inode->i_mode);
+ if (error == 0)
+ acl = NULL;
+ }
+ break;
+
+ case ACL_TYPE_DEFAULT:
+ name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+ if (!S_ISDIR(inode->i_mode))
+ return acl ? -EACCES : 0;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ if (acl) {
+ value = f2fs_acl_to_disk(acl, &size);
+ if (IS_ERR(value)) {
+ clear_inode_flag(fi, FI_ACL_MODE);
+ return (int)PTR_ERR(value);
+ }
+ }
+
+ error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0);
+
+ kfree(value);
+ if (!error)
+ set_cached_acl(inode, type, acl);
+
+ clear_inode_flag(fi, FI_ACL_MODE);
+ return error;
+}
+
+int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+ return __f2fs_set_acl(inode, type, acl, NULL);
+}
+
+/*
+ * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create
+ * are copied from posix_acl.c
+ */
+static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl,
+ gfp_t flags)
+{
+ struct posix_acl *clone = NULL;
+
+ if (acl) {
+ int size = sizeof(struct posix_acl) + acl->a_count *
+ sizeof(struct posix_acl_entry);
+ clone = kmemdup(acl, size, flags);
+ if (clone)
+ atomic_set(&clone->a_refcount, 1);
+ }
+ return clone;
+}
+
+static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
+{
+ struct posix_acl_entry *pa, *pe;
+ struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
+ umode_t mode = *mode_p;
+ int not_equiv = 0;
+
+ /* assert(atomic_read(acl->a_refcount) == 1); */
+
+ FOREACH_ACL_ENTRY(pa, acl, pe) {
+ switch(pa->e_tag) {
+ case ACL_USER_OBJ:
+ pa->e_perm &= (mode >> 6) | ~S_IRWXO;
+ mode &= (pa->e_perm << 6) | ~S_IRWXU;
+ break;
+
+ case ACL_USER:
+ case ACL_GROUP:
+ not_equiv = 1;
+ break;
+
+ case ACL_GROUP_OBJ:
+ group_obj = pa;
+ break;
+
+ case ACL_OTHER:
+ pa->e_perm &= mode | ~S_IRWXO;
+ mode &= pa->e_perm | ~S_IRWXO;
+ break;
+
+ case ACL_MASK:
+ mask_obj = pa;
+ not_equiv = 1;
+ break;
+
+ default:
+ return -EIO;
+ }
+ }
+
+ if (mask_obj) {
+ mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
+ mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
+ } else {
+ if (!group_obj)
+ return -EIO;
+ group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
+ mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
+ }
+
+ *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
+ return not_equiv;
+}
+
+static int f2fs_acl_create(struct inode *dir, umode_t *mode,
+ struct posix_acl **default_acl, struct posix_acl **acl,
+ struct page *dpage)
+{
+ struct posix_acl *p;
+ int ret;
+
+ if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
+ goto no_acl;
+
+ p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage);
+ if (IS_ERR(p)) {
+ if (p == ERR_PTR(-EOPNOTSUPP))
+ goto apply_umask;
+ return PTR_ERR(p);
+ }
+
+ if (!p)
+ goto apply_umask;
+
+ *acl = f2fs_acl_clone(p, GFP_NOFS);
+ if (!*acl)
+ goto no_mem;
+
+ ret = f2fs_acl_create_masq(*acl, mode);
+ if (ret < 0)
+ goto no_mem_clone;
+
+ if (ret == 0) {
+ posix_acl_release(*acl);
+ *acl = NULL;
+ }
+
+ if (!S_ISDIR(*mode)) {
+ posix_acl_release(p);
+ *default_acl = NULL;
+ } else {
+ *default_acl = p;
+ }
+ return 0;
+
+apply_umask:
+ *mode &= ~current_umask();
+no_acl:
+ *default_acl = NULL;
+ *acl = NULL;
+ return 0;
+
+no_mem_clone:
+ posix_acl_release(*acl);
+no_mem:
+ posix_acl_release(p);
+ return -ENOMEM;
+}
+
+int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage,
+ struct page *dpage)
+{
+ struct posix_acl *default_acl = NULL, *acl = NULL;
+ int error = 0;
+
+ error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage);
+ if (error)
+ return error;
+
+ if (default_acl) {
+ error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl,
+ ipage);
+ posix_acl_release(default_acl);
+ }
+ if (acl) {
+ if (!error)
+ error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl,
+ ipage);
+ posix_acl_release(acl);
+ }
+
+ return error;
+}
Code Review / kvmfornfv.git / blobdiff