linux-stable/include/uapi/linux/minix_fs.h
Gustavo A. R. Silva 94dfc73e7c treewide: uapi: Replace zero-length arrays with flexible-array members
There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].

This code was transformed with the help of Coccinelle:
(linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch)

@@
identifier S, member, array;
type T1, T2;
@@

struct S {
  ...
  T1 member;
  T2 array[
- 0
  ];
};

-fstrict-flex-arrays=3 is coming and we need to land these changes
to prevent issues like these in the short future:

../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0,
but the source string has length 2 (including NUL byte) [-Wfortify-source]
		strcpy(de3->name, ".");
		^

Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If
this breaks anything, we can use a union with a new member name.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/78
Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%25lkp@intel.com/
Acked-by: Dan Williams <dan.j.williams@intel.com> # For ndctl.h
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2022-06-28 21:26:05 +02:00

107 lines
2.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _LINUX_MINIX_FS_H
#define _LINUX_MINIX_FS_H
#include <linux/types.h>
#include <linux/magic.h>
/*
* The minix filesystem constants/structures
*/
/*
* Thanks to Kees J Bot for sending me the definitions of the new
* minix filesystem (aka V2) with bigger inodes and 32-bit block
* pointers.
*/
#define MINIX_ROOT_INO 1
/* Not the same as the bogus LINK_MAX in <linux/limits.h>. Oh well. */
#define MINIX_LINK_MAX 250
#define MINIX2_LINK_MAX 65530
#define MINIX_I_MAP_SLOTS 8
#define MINIX_Z_MAP_SLOTS 64
#define MINIX_VALID_FS 0x0001 /* Clean fs. */
#define MINIX_ERROR_FS 0x0002 /* fs has errors. */
#define MINIX_INODES_PER_BLOCK ((BLOCK_SIZE)/(sizeof (struct minix_inode)))
/*
* This is the original minix inode layout on disk.
* Note the 8-bit gid and atime and ctime.
*/
struct minix_inode {
__u16 i_mode;
__u16 i_uid;
__u32 i_size;
__u32 i_time;
__u8 i_gid;
__u8 i_nlinks;
__u16 i_zone[9];
};
/*
* The new minix inode has all the time entries, as well as
* long block numbers and a third indirect block (7+1+1+1
* instead of 7+1+1). Also, some previously 8-bit values are
* now 16-bit. The inode is now 64 bytes instead of 32.
*/
struct minix2_inode {
__u16 i_mode;
__u16 i_nlinks;
__u16 i_uid;
__u16 i_gid;
__u32 i_size;
__u32 i_atime;
__u32 i_mtime;
__u32 i_ctime;
__u32 i_zone[10];
};
/*
* minix super-block data on disk
*/
struct minix_super_block {
__u16 s_ninodes;
__u16 s_nzones;
__u16 s_imap_blocks;
__u16 s_zmap_blocks;
__u16 s_firstdatazone;
__u16 s_log_zone_size;
__u32 s_max_size;
__u16 s_magic;
__u16 s_state;
__u32 s_zones;
};
/*
* V3 minix super-block data on disk
*/
struct minix3_super_block {
__u32 s_ninodes;
__u16 s_pad0;
__u16 s_imap_blocks;
__u16 s_zmap_blocks;
__u16 s_firstdatazone;
__u16 s_log_zone_size;
__u16 s_pad1;
__u32 s_max_size;
__u32 s_zones;
__u16 s_magic;
__u16 s_pad2;
__u16 s_blocksize;
__u8 s_disk_version;
};
struct minix_dir_entry {
__u16 inode;
char name[];
};
struct minix3_dir_entry {
__u32 inode;
char name[];
};
#endif