--- /dev/null
+/*
+ * linux/fs/ext2/acl.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include "ext2.h"
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * Convert from filesystem to in-memory representation.
+ */
+static struct posix_acl *
+ext2_acl_from_disk(const void *value, size_t size)
+{
+ const char *end = (char *)value + size;
+ int n, count;
+ struct posix_acl *acl;
+
+ if (!value)
+ return NULL;
+ if (size < sizeof(ext2_acl_header))
+ return ERR_PTR(-EINVAL);
+ if (((ext2_acl_header *)value)->a_version !=
+ cpu_to_le32(EXT2_ACL_VERSION))
+ return ERR_PTR(-EINVAL);
+ value = (char *)value + sizeof(ext2_acl_header);
+ count = ext2_acl_count(size);
+ if (count < 0)
+ return ERR_PTR(-EINVAL);
+ if (count == 0)
+ return NULL;
+ acl = posix_acl_alloc(count, GFP_KERNEL);
+ if (!acl)
+ return ERR_PTR(-ENOMEM);
+ for (n=0; n < count; n++) {
+ ext2_acl_entry *entry =
+ (ext2_acl_entry *)value;
+ if ((char *)value + sizeof(ext2_acl_entry_short) > end)
+ goto fail;
+ acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
+ acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
+ switch(acl->a_entries[n].e_tag) {
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ value = (char *)value +
+ sizeof(ext2_acl_entry_short);
+ break;
+
+ case ACL_USER:
+ value = (char *)value + sizeof(ext2_acl_entry);
+ if ((char *)value > end)
+ goto fail;
+ acl->a_entries[n].e_uid =
+ make_kuid(&init_user_ns,
+ le32_to_cpu(entry->e_id));
+ break;
+ case ACL_GROUP:
+ value = (char *)value + sizeof(ext2_acl_entry);
+ if ((char *)value > end)
+ goto fail;
+ acl->a_entries[n].e_gid =
+ make_kgid(&init_user_ns,
+ le32_to_cpu(entry->e_id));
+ break;
+
+ default:
+ goto fail;
+ }
+ }
+ if (value != end)
+ goto fail;
+ return acl;
+
+fail:
+ posix_acl_release(acl);
+ return ERR_PTR(-EINVAL);
+}
+
+/*
+ * Convert from in-memory to filesystem representation.
+ */
+static void *
+ext2_acl_to_disk(const struct posix_acl *acl, size_t *size)
+{
+ ext2_acl_header *ext_acl;
+ char *e;
+ size_t n;
+
+ *size = ext2_acl_size(acl->a_count);
+ ext_acl = kmalloc(sizeof(ext2_acl_header) + acl->a_count *
+ sizeof(ext2_acl_entry), GFP_KERNEL);
+ if (!ext_acl)
+ return ERR_PTR(-ENOMEM);
+ ext_acl->a_version = cpu_to_le32(EXT2_ACL_VERSION);
+ e = (char *)ext_acl + sizeof(ext2_acl_header);
+ for (n=0; n < acl->a_count; n++) {
+ const struct posix_acl_entry *acl_e = &acl->a_entries[n];
+ ext2_acl_entry *entry = (ext2_acl_entry *)e;
+ entry->e_tag = cpu_to_le16(acl_e->e_tag);
+ entry->e_perm = cpu_to_le16(acl_e->e_perm);
+ switch(acl_e->e_tag) {
+ case ACL_USER:
+ entry->e_id = cpu_to_le32(
+ from_kuid(&init_user_ns, acl_e->e_uid));
+ e += sizeof(ext2_acl_entry);
+ break;
+ case ACL_GROUP:
+ entry->e_id = cpu_to_le32(
+ from_kgid(&init_user_ns, acl_e->e_gid));
+ e += sizeof(ext2_acl_entry);
+ break;
+
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ e += sizeof(ext2_acl_entry_short);
+ break;
+
+ default:
+ goto fail;
+ }
+ }
+ return (char *)ext_acl;
+
+fail:
+ kfree(ext_acl);
+ return ERR_PTR(-EINVAL);
+}
+
+/*
+ * inode->i_mutex: don't care
+ */
+struct posix_acl *
+ext2_get_acl(struct inode *inode, int type)
+{
+ int name_index;
+ char *value = NULL;
+ struct posix_acl *acl;
+ int retval;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name_index = EXT2_XATTR_INDEX_POSIX_ACL_ACCESS;
+ break;
+ case ACL_TYPE_DEFAULT:
+ name_index = EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT;
+ break;
+ default:
+ BUG();
+ }
+ retval = ext2_xattr_get(inode, name_index, "", NULL, 0);
+ if (retval > 0) {
+ value = kmalloc(retval, GFP_KERNEL);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ retval = ext2_xattr_get(inode, name_index, "", value, retval);
+ }
+ if (retval > 0)
+ acl = ext2_acl_from_disk(value, retval);
+ else if (retval == -ENODATA || retval == -ENOSYS)
+ acl = NULL;
+ else
+ acl = ERR_PTR(retval);
+ kfree(value);
+
+ if (!IS_ERR(acl))
+ set_cached_acl(inode, type, acl);
+
+ return acl;
+}
+
+/*
+ * inode->i_mutex: down
+ */
+int
+ext2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+ int name_index;
+ void *value = NULL;
+ size_t size = 0;
+ int error;
+
+ switch(type) {
+ case ACL_TYPE_ACCESS:
+ name_index = EXT2_XATTR_INDEX_POSIX_ACL_ACCESS;
+ if (acl) {
+ error = posix_acl_equiv_mode(acl, &inode->i_mode);
+ if (error < 0)
+ return error;
+ else {
+ inode->i_ctime = CURRENT_TIME_SEC;
+ mark_inode_dirty(inode);
+ if (error == 0)
+ acl = NULL;
+ }
+ }
+ break;
+
+ case ACL_TYPE_DEFAULT:
+ name_index = EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT;
+ if (!S_ISDIR(inode->i_mode))
+ return acl ? -EACCES : 0;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+ if (acl) {
+ value = ext2_acl_to_disk(acl, &size);
+ if (IS_ERR(value))
+ return (int)PTR_ERR(value);
+ }
+
+ error = ext2_xattr_set(inode, name_index, "", value, size, 0);
+
+ kfree(value);
+ if (!error)
+ set_cached_acl(inode, type, acl);
+ return error;
+}
+
+/*
+ * Initialize the ACLs of a new inode. Called from ext2_new_inode.
+ *
+ * dir->i_mutex: down
+ * inode->i_mutex: up (access to inode is still exclusive)
+ */
+int
+ext2_init_acl(struct inode *inode, struct inode *dir)
+{
+ struct posix_acl *default_acl, *acl;
+ int error;
+
+ error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
+ if (error)
+ return error;
+
+ if (default_acl) {
+ error = ext2_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
+ posix_acl_release(default_acl);
+ }
+ if (acl) {
+ if (!error)
+ error = ext2_set_acl(inode, acl, ACL_TYPE_ACCESS);
+ posix_acl_release(acl);
+ }
+ return error;
+}
Code Review / kvmfornfv.git / blobdiff