diff options
| -rw-r--r-- | fs/hfsplus/posix_acl.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/fs/hfsplus/posix_acl.c b/fs/hfsplus/posix_acl.c new file mode 100644 index 000000000000..b609cc14c72e --- /dev/null +++ b/fs/hfsplus/posix_acl.c @@ -0,0 +1,274 @@ +/* + * linux/fs/hfsplus/posix_acl.c + * + * Vyacheslav Dubeyko <slava@dubeyko.com> + * + * Handler for Posix Access Control Lists (ACLs) support. + */ + +#include "hfsplus_fs.h" +#include "xattr.h" +#include "acl.h" + +struct posix_acl *hfsplus_get_posix_acl(struct inode *inode, int type) +{ + struct posix_acl *acl; + char *xattr_name; + char *value = NULL; + ssize_t size; + + acl = get_cached_acl(inode, type); + if (acl != ACL_NOT_CACHED) + return acl; + + switch (type) { + case ACL_TYPE_ACCESS: + xattr_name = POSIX_ACL_XATTR_ACCESS; + break; + case ACL_TYPE_DEFAULT: + xattr_name = POSIX_ACL_XATTR_DEFAULT; + break; + default: + return ERR_PTR(-EINVAL); + } + + size = __hfsplus_getxattr(inode, xattr_name, NULL, 0); + + if (size > 0) { + value = (char *)hfsplus_alloc_attr_entry(); + if (unlikely(!value)) + return ERR_PTR(-ENOMEM); + size = __hfsplus_getxattr(inode, xattr_name, value, size); + } + + if (size > 0) + acl = posix_acl_from_xattr(&init_user_ns, value, size); + else if (size == -ENODATA) + acl = NULL; + else + acl = ERR_PTR(size); + + hfsplus_destroy_attr_entry((hfsplus_attr_entry *)value); + + if (!IS_ERR(acl)) + set_cached_acl(inode, type, acl); + + return acl; +} + +static int hfsplus_set_posix_acl(struct inode *inode, + int type, + struct posix_acl *acl) +{ + int err; + char *xattr_name; + size_t size = 0; + char *value = NULL; + + if (S_ISLNK(inode->i_mode)) + return -EOPNOTSUPP; + + switch (type) { + case ACL_TYPE_ACCESS: + xattr_name = POSIX_ACL_XATTR_ACCESS; + if (acl) { + err = posix_acl_equiv_mode(acl, &inode->i_mode); + if (err < 0) + return err; + } + err = 0; + break; + + case ACL_TYPE_DEFAULT: + xattr_name = POSIX_ACL_XATTR_DEFAULT; + if (!S_ISDIR(inode->i_mode)) + return acl ? -EACCES : 0; + break; + + default: + return -EINVAL; + } + + if (acl) { + size = posix_acl_xattr_size(acl->a_count); + if (unlikely(size > HFSPLUS_MAX_INLINE_DATA_SIZE)) + return -ENOMEM; + value = (char *)hfsplus_alloc_attr_entry(); + if (unlikely(!value)) + return -ENOMEM; + err = posix_acl_to_xattr(&init_user_ns, acl, value, size); + if (unlikely(err < 0)) + goto end_set_acl; + } + + err = __hfsplus_setxattr(inode, xattr_name, value, size, 0); + +end_set_acl: + hfsplus_destroy_attr_entry((hfsplus_attr_entry *)value); + + if (!err) + set_cached_acl(inode, type, acl); + + return err; +} + +int hfsplus_init_posix_acl(struct inode *inode, struct inode *dir) +{ + int err = 0; + struct posix_acl *acl = NULL; + + hfs_dbg(ACL_MOD, + "[%s]: ino %lu, dir->ino %lu\n", + __func__, inode->i_ino, dir->i_ino); + + if (S_ISLNK(inode->i_mode)) + return 0; + + acl = hfsplus_get_posix_acl(dir, ACL_TYPE_DEFAULT); + if (IS_ERR(acl)) + return PTR_ERR(acl); + + if (acl) { + if (S_ISDIR(inode->i_mode)) { + err = hfsplus_set_posix_acl(inode, + ACL_TYPE_DEFAULT, + acl); + if (unlikely(err)) + goto init_acl_cleanup; + } + + err = posix_acl_create(&acl, GFP_NOFS, &inode->i_mode); + if (unlikely(err < 0)) + return err; + + if (err > 0) + err = hfsplus_set_posix_acl(inode, + ACL_TYPE_ACCESS, + acl); + } else + inode->i_mode &= ~current_umask(); + +init_acl_cleanup: + posix_acl_release(acl); + return err; +} + +int hfsplus_posix_acl_chmod(struct inode *inode) +{ + int err; + struct posix_acl *acl; + + hfs_dbg(ACL_MOD, "[%s]: ino %lu\n", __func__, inode->i_ino); + + if (S_ISLNK(inode->i_mode)) + return -EOPNOTSUPP; + + acl = hfsplus_get_posix_acl(inode, ACL_TYPE_ACCESS); + if (IS_ERR(acl) || !acl) + return PTR_ERR(acl); + + err = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode); + if (unlikely(err)) + return err; + + err = hfsplus_set_posix_acl(inode, ACL_TYPE_ACCESS, acl); + posix_acl_release(acl); + return err; +} + +static int hfsplus_xattr_get_posix_acl(struct dentry *dentry, + const char *name, + void *buffer, + size_t size, + int type) +{ + int err = 0; + struct posix_acl *acl; + + hfs_dbg(ACL_MOD, + "[%s]: ino %lu, buffer %p, size %zu, type %#x\n", + __func__, dentry->d_inode->i_ino, buffer, size, type); + + if (strcmp(name, "") != 0) + return -EINVAL; + + acl = hfsplus_get_posix_acl(dentry->d_inode, type); + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (acl == NULL) + return -ENODATA; + + err = posix_acl_to_xattr(&init_user_ns, acl, buffer, size); + posix_acl_release(acl); + + return err; +} + +static int hfsplus_xattr_set_posix_acl(struct dentry *dentry, + const char *name, + const void *value, + size_t size, + int flags, + int type) +{ + int err = 0; + struct inode *inode = dentry->d_inode; + struct posix_acl *acl = NULL; + + hfs_dbg(ACL_MOD, + "[%s]: ino %lu, value %p, size %zu, flags %#x, type %#x\n", + __func__, inode->i_ino, value, size, flags, type); + + if (strcmp(name, "") != 0) + return -EINVAL; + + if (!inode_owner_or_capable(inode)) + return -EPERM; + + if (value) { + acl = posix_acl_from_xattr(&init_user_ns, value, size); + if (IS_ERR(acl)) + return PTR_ERR(acl); + else if (acl) { + err = posix_acl_valid(acl); + if (err) + goto end_xattr_set_acl; + } + } + + err = hfsplus_set_posix_acl(inode, type, acl); + +end_xattr_set_acl: + posix_acl_release(acl); + return err; +} + +static size_t hfsplus_xattr_list_posix_acl(struct dentry *dentry, + char *list, + size_t list_size, + const char *name, + size_t name_len, + int type) +{ + /* + * This method is not used. + * It is used hfsplus_listxattr() instead of generic_listxattr(). + */ + return -EOPNOTSUPP; +} + +const struct xattr_handler hfsplus_xattr_acl_access_handler = { + .prefix = POSIX_ACL_XATTR_ACCESS, + .flags = ACL_TYPE_ACCESS, + .list = hfsplus_xattr_list_posix_acl, + .get = hfsplus_xattr_get_posix_acl, + .set = hfsplus_xattr_set_posix_acl, +}; + +const struct xattr_handler hfsplus_xattr_acl_default_handler = { + .prefix = POSIX_ACL_XATTR_DEFAULT, + .flags = ACL_TYPE_DEFAULT, + .list = hfsplus_xattr_list_posix_acl, + .get = hfsplus_xattr_get_posix_acl, + .set = hfsplus_xattr_set_posix_acl, +}; |